Search results for: plastic surgery
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1988

Search results for: plastic surgery

1328 Evaluation of Role of Surgery in Management of Pediatric Germ Cell Tumors According to Risk Adapted Therapy Protocols

Authors: Ahmed Abdallatif

Abstract:

Background: Patients with malignant germ cell tumors have age distribution in two peaks, with the first one during infancy and the second after the onset of puberty. Gonadal germ cell tumors are the most common malignant ovarian tumor in females aged below twenty years. Sacrococcygeal and retroperitoneal abdominal tumors usually presents in a large size before the onset of symptoms. Methods: Patients with pediatric germ cell tumors presenting to Children’s Cancer Hospital Egypt and National Cancer Institute Egypt from January 2008 to June 2011 Patients underwent stratification according to risk into low, intermediate and high risk groups according to children oncology group classification. Objectives: Assessment of the clinicopathologic features of all cases of pediatric germ cell tumors and classification of malignant cases according to their stage, and the primary site to low, intermediate and high risk patients. Evaluation of surgical management in each group of patients focusing on surgical approach, the extent of surgical resection according to each site, ability to achieve complete surgical resection and perioperative complications. Finally, determination of the three years overall and disease-free survival in different groups and the relation to different prognostic factors including the extent of surgical resection. Results: Out of 131 cases surgically explored only 26 cases had re exploration with 8 cases explored for residual disease 9 cases for remote recurrence or metastatic disease and the other 9 cases for other complications. Patients with low risk kept under follow up after surgery, out of those of low risk group (48 patients) only 8 patients (16.5%) shifted to intermediate risk. There were 20 patients (14.6%) diagnosed as intermediate risk received 3 cycles of compressed (Cisplatin, Etoposide and Bleomycin) and all high risk group patients 69patients (50.4%) received chemotherapy. Stage of disease was strongly and significantly related to overall survival with a poorer survival in late stages (stage IV) as compared to earlier stages. Conclusion: Overall survival rate at 3 three years was (76.7% ± 5.4, 3) years EFS was (77.8 % ±4.0), however 3 years DFS was much better (89.8 ± 3.4) in whole study group with ovarian tumors had significantly higher Overall survival (90% ± 5.1). Event Free Survival analysis showed that Male gender was 3 times likely to have bad events than females. Patients who underwent incomplete resection were 4 times more than patients with complete resection to have bad events. Disease free survival analysis showed that Patients who underwent incomplete surgery were 18.8 times liable for recurrence compared to those who underwent complete surgery, and patients who were exposed to re-excision were 21 times more prone to recurrence compared to other patients.

Keywords: extragonadal, germ cell tumors, gonadal, pediatric

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1327 Knowledge, Attitude, and Practice of Medical Ethics amongst Paediatric Surgeons and Trainees in Malaysia

Authors: Salehah Tahkin, Norlaila Mustafa, Dayang Anita Abdul Aziz

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Knowledge of medical ethics is important to all practitioners so the best care can be delivered to all patients through safe practice. Surgeons are not exceptions to this. Knowledge, attitude, and practice (KAP) of medical ethics among paediatric surgeons and trainees in Malaysia has not been evaluated before. This study aims to determine the level of KAP regarding medical ethics among these groups. This was a cross-sectional study involving three groups of samples, i.e., paediatric surgeons (PS), paediatric surgical trainees (PST), and medical officers with a special interest in paediatric surgery (MO). A validated KAP questionnaire was used. Standard formulas were used to calculate objective indexes for measuring KAP, which were then compared for statistical significance across different sample groups; p less than 0.05 is taken as significant. The index is rated into 5 classes using a score of 0 to 10, i.e., poor (1-2.99), fair (3-4.99), good (5-6.99), very good (7-8.99), and excellent (9-10). There were 117 samples, i.e., PS n=45 (38.5%), PST n=25 (21.3%), and MO n=47 (40.2%). For knowledge, all three groups display a good index score (mean score of 5.44). For attitude, PS and MO also display an index score of good (mean score of 5.81), while the PST index score was fair (4.82). For practice, our study shows a highest score of 7.14 (very good) among PST. However, these differences were not statistically significant (p> 0.05). Conclusion: Training in paediatric surgery must continue to emphasize professionalism and medical ethics education to deliver the best health care services.

Keywords: KAP, medical ethics, paediatric, surgeons, trainees

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1326 The Effect of Psychosocial, Behavioral and Disease Specific Characteristics on Health-Related Quality of Life after Primary Surgery for Colorectal Cancer: A Cross Sectional Study of a Regional Australian Population

Authors: Lakmali Anthony, Madeline Gillies

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Background: Colorectal cancer (CRC) is usually managed with surgical resection. Many of the outcomes traditionally used to define successful operative management, such as resection margin, do not adequately reflect patients’ experience. Patient-reported outcomes (PRO), such as Health-Related Quality of life (HRQoL), provide a means by which the impact of surgery for cancer can be reported in a patient-centered way. HRQoL has previously been shown to be impacted by psychosocial, behavioral and disease-specific characteristics. This exploratory cross-sectional study aims to; (1) describe postoperative HRQoL in patients who underwent primary resection in a regional Australian hospital; (2) describe the prevalence of anxiety, depression and clinically significant fear of cancer recurrence (FCR) in this population; and (3) identify demographic, psychosocial, disease and treatment factors associated with poorer self-reported HRQoL. Methods: Consecutive patients who had resection of colorectal cancer in a single regional Australian hospital between 2015 and 2022 were eligible. Participants were asked to complete a survey instrument designed to assess HRQoL, as well as validated instruments that assess several other psychosocial PROs hypothesized to be associated with HRQoL; emotional distress, fear of cancer recurrence, social support, dispositional optimism, body image and spirituality. Demographic and disease-specific data were also collected via medical record review. Results: Forty-six patients completed the survey. Clinically significant levels of fear of recurrence as well as emotional distress, were present in this group. Many domains of HRQoL were significantly worse than an Australian reference population for CRC. Demographic and disease factors associated with poor HRQoL included smoking and ongoing adjuvant systemic therapy. The primary operation was not associated with HRQoL; however, the operative approach (laparoscopic vs. open) was associated with HRQoL for these patients. All psychosocial factors measured were associated with HRQoL, including cancer worry, emotional distress, body image and dispositional optimism. Conclusion: HRQoL is an important outcome in surgery for both research and clinical practice. This study provides an overview of the quality of life in a regional Australian population of postoperative colorectal cancer patients and the factors that affect it. Understanding HRQoL and awareness of patients particularly vulnerable to poor outcomes should be used to aid the informed consent and shared decision-making process between surgeon and patient.

Keywords: surgery, colorectal, cancer, PRO, HRQoL

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1325 Management of Facial Nerve Palsy Following Physiotherapy

Authors: Bassam Band, Simon Freeman, Rohan Munir, Hisham Band

Abstract:

Objective: To determine efficacy of facial physiotherapy provided for patients with facial nerve palsy. Design: Retrospective study Subjects: 54 patients diagnosed with Facial nerve palsy were included in the study after they met the selection criteria including unilateral facial paralysis and start of therapy twelve months after the onset of facial nerve palsy. Interventions: Patients received the treatment offered at a facial physiotherapy clinic consisting of: Trophic electrical stimulation, surface electromyography with biofeedback, neuromuscular re-education and myofascial release. Main measures: The Sunnybrook facial grading scale was used to evaluate the severity of facial paralysis. Results: This study demonstrated the positive impact of physiotherapy for patient with facial nerve palsy with improvement of 24.2% on the Sunnybrook facial grading score from a mean baseline of 34.2% to 58.2%. The greatest improvement looking at different causes was seen in patient who had reconstructive surgery post Acoustic Neuroma at 31.3%. Conclusion: The therapy shows significant improvement for patients with facial nerve palsy even when started 12 months post onset of paralysis across different causes. This highlights the benefit of this non-invasive technique in managing facial nerve paralysis and possibly preventing the need for surgery.

Keywords: facial nerve palsy, treatment, physiotherapy, bells palsy, acoustic neuroma, ramsey-hunt syndrome

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1324 Determining Which Material Properties Resist the Tool Wear When Machining Pre-Sintered Zirconia

Authors: David Robert Irvine

Abstract:

In the dental restoration sector, there has been a shift to using zirconia. With the ever increasing need to decrease lead times to deliver restorations faster the zirconia is machined in its pre-sintered state instead of grinding the very hard sintered state. As with all machining, there is tool wear and while investigating the tooling used to machine pre-sintered zirconia it became apparent that the wear rate is based more on material build up and abrasion than it is on plastic deformation like conventional metal machining. It also came to light that the tool material can currently not be selected based on wear resistance, as there is no data. Different works have analysed the effect of the individual wear mechanism separately using similar if not the same material. In this work, the testing method used to analyse the wear was a modified from ISO 8688:1989 to use the pre-sintered zirconia and the cutting conditions used in dental to machine it. This understanding was developed through a series of tests based in machining operations, to give the best representation of the multiple wear factors that can occur in machining of pre-sintered zirconia such as 3 body abrasion, material build up, surface welding, plastic deformation, tool vibration and thermal cracking. From the testing, it found that carbide grades with low trans-granular rupture toughness would fail due to abrasion while those with high trans-granular rupture toughness failed due to edge chipping from build up or thermal properties. The results gained can assist the development of these tools and the restorative dental process. This work was completed with the aim of assisting in the selection of tool material for future tools along with a deeper understanding of the properties that assist in abrasive wear resistance and material build up.

Keywords: abrasive wear, cemented carbide, pre-sintered zirconia, tool wear

Procedia PDF Downloads 142
1323 Uranoplasty Using Tongue Flap for Bilateral Clefts

Authors: Saidasanov Saidazal Shokhmurodovich, Topolnickiy Orest Zinovyevich, Afaunova Olga Arturovna

Abstract:

Relevance: Bilateral congenital cleft is one of the most complex forms of all clefts, which makes it difficult to choose a surgical method of treatment. During primary operations to close the hard and soft palate, there is a shortage of soft tissues and their lack during standard uranoplasty, and these factors aggravate the period of rehabilitation of patients. Materials and methods: The results of surgical treatment of children with bilateral cleft, who underwent uranoplasty using a flap from the tongue, were analyzed. The study used methods: clinical and statistical, which allowed us to solve the tasks, based on the principles of evidence-based medicine. Results and discussion: in our study, 15 patients were studied, who underwent surgical treatment in the following volume: uranoplasty using a flap from the tongue in two stages. Of these, 9 boys and 6 girls aged 2.5 to 6 years. The first stage was surgical treatment in the volume: veloplasty. The second stage was a surgical intervention in volume: uranoplasty using a flap from the tongue. In all patients, the width of the cleft ranged from 1.6-2.8 cm. All patients in this group were orthodontically prepared. Using this method, the surgeon can achieve the following results: maximum narrowing of the palatopharyngeal ring, long soft palate, complete closure of the hard palate, alveolar process, and the mucous membrane of the nasal cavity is also sutured, which creates good conditions for the next stage of osteoplastic surgery. Based on the result obtained, patients have positive results of working with a speech therapist. In all patients, the dynamics were positive without complications. Conclusions: Based on our observation, tongue flap uranoplasty is one of the effective techniques for patients with wide clefts of the hard and soft palate. The use of a flap from the tongue makes it possible to reduce the number of repeated reoperations and improve the quality of social adaptation of this group of patients, which is one of the important stages of rehabilitation. Upon completion of the stages of rehabilitation, all patients had the maximum improvement in functional, anatomical and social indicators.

Keywords: congenital cleft lips and palate, bilateral cleft, child surgery, maxillofacial surgery

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1322 Use of a Laparoscopic Approach in Urgent Adhesive Small Bowel Obstructions

Authors: Nuhi Arslani, Aleks Brumec

Abstract:

Adhesive small bowel obstruction (ASBO) accounts for 20% of emergency surgical procedures and intraabdominal adhesions account for 65% of such cases. In a 10-year post-operative period of abdominal surgery patients, around 35% of them will be readmitted because of ASBO. The first step in approaching ASBOs is using the Bologna guidelines, which include a thorough initial evaluation to diagnose or rule out an ASBO and then proceed with either further imaging studies or emergency surgery, which can be either open or laparoscopic. The contraindications for a laparoscopic approach include hemodynamic instability of the patient and infections in the peritoneum or port sites. Studies have shown that a laparoscopic approach to adhesiolysis is linked with a significantly smaller risk of readmissions and reoperations as well as with faster recovery time and fewer postoperative infections, but has a higher risk of bowel injuries, so a careful selection of patients is required. Although studies favor a laparoscopic approach, many countries still prefer a laparotomy, often because a laparoscopic approach requires surgeons to be highly skilled in the procedure. In the US and UK, between 50 and 60% of surgeons would approach an ASBO with laparoscopy, while in Italy, this number is around 15% and it is most likely similar in Slovenia. We believe that in the right cases and in the right patients, a laparoscopic approach can be equally feasible for treating ASBOs and is associated with fewer intraoperative and postoperative complications.

Keywords: adhesive small bowel obstruction, laparoscopy, adhesions, adhesiolysis

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1321 An Integrated Experimental and Numerical Approach to Develop an Electronic Instrument to Study Apple Bruise Damage

Authors: Paula Pascoal-Faria, Rúben Pereira, Elodie Pinto, Miguel Belbut, Ana Rosa, Inês Sousa, Nuno Alves

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Apple bruise damage from harvesting, handling, transporting and sorting is considered to be the major source of reduced fruit quality, resulting in loss of profits for the entire fruit industry. The three factors which can physically cause fruit bruising are vibration, compression load and impact, the latter being the most common source of bruise damage. Therefore, prediction of the level of damage, stress distribution and deformation of the fruits under external force has become a very important challenge. In this study, experimental and numerical methods were used to better understand the impact caused when an apple is dropped from different heights onto a plastic surface and a conveyor belt. Results showed that the extent of fruit damage is significantly higher for plastic surface, being dependent on the height. In order to support the development of a biomimetic electronic device for the determination of fruit damage, the mechanical properties of the apple fruit were determined using mechanical tests. Preliminary results showed different values for the Young’s modulus according to the zone of the apple tested. Along with the mechanical characterization of the apple fruit, the development of the first two prototypes is discussed and the integration of the results obtained to construct the final element model of the apple is presented. This work will help to reduce significantly the bruise damage of fruits or vegetables during the entire processing which will allow the introduction of exportation destines and consequently an increase in the economic profits in this sector.

Keywords: apple, fruit damage, impact during crop and post-crop, mechanical characterization of the apple, numerical evaluation of fruit damage, electronic device

Procedia PDF Downloads 281
1320 Prediction of Changes in Optical Quality by Tissue Redness after Pterygium Surgery

Authors: Mohd Radzi Hilmi, Mohd Zulfaezal Che Azemin, Khairidzan Mohd Kamal, Azrin Esmady Ariffin, Mohd Izzuddin Mohd Tamrin, Norfazrina Abdul Gaffur, Tengku Mohd Tengku Sembok

Abstract:

Purpose: The purpose of this study is to predict optical quality changes after pterygium surgery using tissue redness grading. Methods: Sixty-eight primary pterygium participants were selected from patients who visited an ophthalmology clinic. We developed a semi-automated computer program to measure the pterygium fibrovascular redness from digital pterygium images. The outcome of this software is a continuous scale grading of 1 (minimum redness) to 3 (maximum redness). The region of interest (ROI) was selected manually using the software. Reliability was determined by repeat grading of all 68 images and its association with contrast sensitivity function (CSF) and visual acuity (VA) was examined. Results: The mean and standard deviation of redness of the pterygium fibrovascular images was 1.88 ± 0.55. Intra- and inter-grader reliability estimates were high with intraclass correlation ranging from 0.97 to 0.98. The new grading was positively associated with CSF (p<0.01) and VA (p<0.01). The redness grading was able to predict 25% and 23% of the variance in the CSF and the VA respectively. Conclusions: The new grading of pterygium fibrovascular redness can be reliably measured from digital images and show a good correlation with CSF and VA. The redness grading can be used in addition to the existing pterygium grading.

Keywords: contrast sensitivity, pterygium, redness, visual acuity

Procedia PDF Downloads 491
1319 Recognising and Managing Haematoma Following Thyroid Surgery: Simulation Teaching is Effective

Authors: Emily Moore, Dora Amos, Tracy Ellimah, Natasha Parrott

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Postoperative haematoma is a well-recognised complication of thyroid surgery with an incidence of 1-5%. Haematoma formation causes progressive airway obstruction, necessitating emergency bedside haematoma evacuation in up to ¼ of patients. ENT UK, BAETS and DAS have developed consensus guidelines to improve perioperative care, recommending that all healthcare staff interacting with patients undergoing thyroid surgery should be trained in managing post-thyroidectomy haematoma. The aim was to assess the effectiveness of a hybrid simulation model in improving clinician’s confidence in dealing with this surgical emergency. A hybrid simulation was designed, consisting of a standardised patient wearing a part-task trainer to mimic a post-thyroidectomy haematoma in a real patient. The part-task trainer was an adapted C-spine collar with layers of silicone representing the skin and strap muscles and thickened jelly representing the haematoma. Both the skin and strap muscle layers had to be opened in order to evacuate the haematoma. Boxes have been implemented into the appropriate post operative areas (recovery and surgical wards), which contain a printed algorithm designed to assist in remembering a sequence of steps for haematoma evacuation using the ‘SCOOP’ method (skin exposure, cut sutures, open skin, open muscles, pack wound) along with all the necessary equipment to open the front of the neck. Small-group teaching sessions were delivered by ENT and anaesthetic trainees to members of the multidisciplinary team normally involved in perioperative patient care, which included ENT surgeons, anaesthetists, recovery nurses, HCAs and ODPs. The DESATS acronym of signs and symptoms to recognise (difficulty swallowing, EWS score, swelling, anxiety, tachycardia, stridor) was highlighted. Then participants took part in the hybrid simulation in order to practice this ‘SCOOP’ method of haematoma evacuation. Participants were surveyed using a Likert scale to assess their level of confidence pre- and post teaching session. 30 clinicians took part. Confidence (agreed/strongly agreed) in recognition of post thyroidectomy haematoma improved from 58.6% to 96.5%. Confidence in management improved from 27.5% to 89.7%. All participants successfully decompressed the haematoma. All participants agreed/strongly agreed, that the sessions were useful for their learning. Multidisciplinary team simulation teaching is effective at significantly improving confidence in both the recognition and management of postoperative haematoma. Hybrid simulation sessions are useful and should be incorporated into training for clinicians.

Keywords: thyroid surgery, haematoma, teaching, hybrid simulation

Procedia PDF Downloads 78
1318 Extrudable Foamed Concrete: General Benefits in Prefabrication and Comparison in Terms of Fresh Properties and Compressive Strength with Classic Foamed Concrete

Authors: D. Falliano, G. Ricciardi, E. Gugliandolo

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Foamed concrete belongs to the category of lightweight concrete. It is characterized by a density which is generally ranging from 200 to 2000 kg/m³ and typically comprises cement, water, preformed foam, fine sand and eventually fine particles such as fly ash or silica fume. The foam component mixed with the cement paste give rise to the development of a system of air-voids in the cementitious matrix. The peculiar characteristics of foamed concrete elements are summarized in the following aspects: 1) lightness which allows reducing the dimensions of the resisting frame structure and is advantageous in the scope of refurbishment or seismic retrofitting in seismically vulnerable areas; 2) thermal insulating properties, especially in the case of low densities; 3) the good resistance against fire as compared to ordinary concrete; 4) the improved workability; 5) cost-effectiveness due to the usage of rather simple constituting elements that are easily available locally. Classic foamed concrete cannot be extruded, as the dimensional stability is not permitted in the green state and this severely limits the possibility of industrializing them through a simple and cost-effective process, characterized by flexibility and high production capacity. In fact, viscosity enhancing agents (VEA) used to extrude traditional concrete, in the case of foamed concrete cause the collapsing of air bubbles, so that it is impossible to extrude a lightweight product. These requirements have suggested the study of a particular additive that modifies the rheology of foamed concrete fresh paste by increasing cohesion and viscosity and, at the same time, stabilizes the bubbles into the cementitious matrix, in order to allow the dimensional stability in the green state and, consequently, the extrusion of a lightweight product. There are plans to submit the additive’s formulation to patent. In addition to the general benefits of using the extrusion process, extrudable foamed concrete allow other limits to be exceeded: elimination of formworks, expanded application spectrum, due to the possibility of extrusion in a range varying between 200 and 2000 kg/m³, which allows the prefabrication of both structural and non-structural constructive elements. Besides, this contribution aims to present the significant differences regarding extrudable and classic foamed concrete fresh properties in terms of slump. Plastic air content, plastic density, hardened density and compressive strength have been also evaluated. The outcomes show that there are no substantial differences between extrudable and classic foamed concrete compression resistances.

Keywords: compressive strength, extrusion, foamed concrete, fresh properties, plastic air content, slump.

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1317 Preventive and Attenuative Effect of Vitamin E on Selenite-induced Cataract in Rat

Authors: Seyedeh Zeinab Peighambarzadeh, Mehdi Tavana

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Cataract is the most common cause of blindness worldwide and its incidence will increase as the World’s population ages. Even in modern ophthalmology, there is no effective medical treatment for cataract except surgery. Development of a drug which could prevent or delay the onset of cataract will lessen this burden and reduce the number of blind patients waiting for cataract surgery. This study was undertaken to evaluate the protective effect of vitamin E on Selenite-induced Cataract in Sprague-dawely rats. Cataracts were induced in rats by administration of sodium selenite. On postpartum day ten, in group I, saline was injected subcutaneously. Group II rat pups received subcutaneous injection of vitamin E (60mg/kg B.W.) at day 8 postpartum and every other day thereafter. Group III and IV rat pups received a subcutaneous injection of sodium selenite (13mg/kg B.W.) at day 10 postpartum. Group IV also received subcutaneous injection of vitamin E (60mg/kg B.W.) at day 8 postpartum and every other day thereafter. The development of cataract in rats was assessed clinically by slit-lamp biomicroscope from day 14 up to postpartum day 28. After sacrifice, extricated pup lenses were analyzed for total and soluble protein concentrations and eletrophoretic pattern (SDS-PAGE). There was no opacification of lens in Group I and II. There was mature cataract in 95% of Group III. In group IV, 55% of rats developed sub capsular or cortical cataract. Cataractous and biochemical changes of the crystalline lens proteins due to selenite can be retard or prevented by vitamin E.

Keywords: preventive effect, selenite-induced cataract, vitamin E, rat

Procedia PDF Downloads 357
1316 Effectiveness of Laughter Yoga in Reducing Anxiety among Pre-Operative Patients for Scheduled Major Surgery

Authors: Denise Allison D. Garcia, Camille C. Garcia, Keanu Raphael Garrido, Crestita B. Tan

Abstract:

Introduction: Anxiety is a common problem among pre-operative patients. Several methods or interventions are being applied in order to relieve anxiety. Laughter yoga, however, is a method that has been used to relieve anxiety but has not yet been tested to pre-operative patients. Therefore, this study determined the effectiveness of laughter yoga in reducing anxiety among pre-operative middle-aged patients scheduled for major surgery. Methods: After Ethics Review Board approval, a quasi-experimental study was conducted among 40 purposely-selected pre-operative patients in two tertiary hospitals. Anxiety level was measured prior to administration of laughter yoga using the State-Trait Anxiety Inventory with a Cronbach alpha of 0.83. After Laughter yoga, anxiety level was then measured again. Gathered data were analyzed in SPSS version 20 using paired and independent t-test and ANCOVA. Results: After analysis of the data gathered, the results showed that there was a significant decrease in the anxiety level of patients in the experimental group. From an anxiety level of 44.00, the rating went down to 36.85. Meanwhile in the control group, the anxiety level at the pretest at 41.25 went up to 42.50. Laughter yoga was an effective non-pharmacologic intervention for reducing anxiety of pre-operative patients. Conclusion: It is therefore concluded that laughter yoga causes a significant decrease in the anxiety level of patients.

Keywords: anxiety, laughter yoga, non-pharmacologic, pre-operative

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1315 High Pressure Torsion Deformation Behavior of a Low-SFE FCC Ternary Medium Entropy Alloy

Authors: Saumya R. Jha, Krishanu Biswas, Nilesh P. Gurao

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Several recent investigations have revealed medium entropy alloys exhibiting better mechanical properties than their high entropy counterparts. This clearly establishes that although a higher entropy plays a vital role in stabilization of particular phase over complex intermetallic phases, configurational entropy is not the primary factor responsible for the high inherent strengthening in these systems. Above and beyond a high contribution from friction stresses and solid solution strengthening, strain hardening is an important contributor to the strengthening in these systems. In this regard, researchers have developed severe plastic deformation (SPD) techniques like High Pressure Torsion (HPT) to incorporate very high shear strain in the material, thereby leading to ultrafine grained (UFG) microstructures, which cause manifold increase in the strength. The presented work demonstrates a meticulous study of the variation in mechanical properties at different radial displacements from the center of HPT tested equiatomic ternary FeMnNi synthesized by casting route, which is a low stacking fault energy FCC alloy that shows significantly higher toughness than its high entropy counterparts like Cantor alloy. The gradient in grain sizes along the radial direction of these specimens has been modeled using microstructure entropy for predicting the mechanical properties, which has also been validated by indentation tests. The dislocation density is computed by FEM simulations for varying strains and validated by analyzing synchrotron diffraction data. Thus, the proposed model can be utilized to predict the strengthening behavior of similar systems deformed by HPT subjected to varying loading conditions.

Keywords: high pressure torsion, severe plastic deformation, configurational entropy, dislocation density, FEM simulation

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1314 On Crack Tip Stress Field in Pseudo-Elastic Shape Memory Alloys

Authors: Gulcan Ozerim, Gunay Anlas

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In shape memory alloys, upon loading, stress increases around crack tip and a martensitic phase transformation occurs in early stages. In many studies the stress distribution in the vicinity of the crack tip is represented by using linear elastic fracture mechanics (LEFM) although the pseudo-elastic behavior results in a nonlinear stress-strain relation. In this study, the HRR singularity (Hutchinson, Rice and Rosengren), that uses Rice’s path independent J-integral, is tried to formulate the stress distribution around the crack tip. In HRR approach, the Ramberg-Osgood model for the stress-strain relation of power-law hardening materials is used to represent the elastic-plastic behavior. Although it is recoverable, the inelastic portion of the deformation in martensitic transformation (up to the end of transformation) resembles to that of plastic deformation. To determine the constants of the Ramberg-Osgood equation, the material’s response is simulated in ABAQUS using a UMAT based on ZM (Zaki-Moumni) thermo-mechanically coupled model, and the stress-strain curve of the material is plotted. An edge cracked shape memory alloy (Nitinol) plate is loaded quasi-statically under mode I and modeled using ABAQUS; the opening stress values ahead of the cracked tip are calculated. The stresses are also evaluated using the asymptotic equations of both LEFM and HRR. The results show that in the transformation zone around the crack tip, the stress values are much better represented when the HRR singularity is used although the J-integral does not show path independent behavior. For the nodes very close to the crack tip, the HRR singularity is not valid due to the non-proportional loading effect and high-stress values that go beyond the transformation finish stress.

Keywords: crack, HRR singularity, shape memory alloys, stress distribution

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1313 Design of a Lumbar Interspinous Process Fixation Device for Minimizing Soft Tissue Removal and Operation Time

Authors: Minhyuk Heo, Jihwan Yun, Seonghun Park

Abstract:

It has been reported that intervertebral fusion surgery, which removes most of the ligaments and muscles of the spine, increases the degenerative disease in adjacent spinal segments. Therefore, it is required to develop a lumbar interspinous process fixation device that minimizes the risks and side effects from the surgery. The objective of the current study is to design an interspinous process fixation device with simple structures in order to minimize soft tissue removal and operation time during intervertebral fusion surgery. For the design concepts of a lumbar fixation device, the principle of the ratchet was first applied on the joining parts of the device in order to shorten the operation time. The coil spring structure was selected for connecting parts between the spinous processes so that a normal range of motion in spinal segments is preserved and degenerative spinal diseases are not developed in the adjacent spinal segments. The stiffness of the spring was determined not to interrupt the motion of a lumbar spine. The designed value of the spring stiffness allows the upper part of the spring to move ~10° which is higher than the range of flexion and extension for normal lumbar spine (6°-8°), when a moment of 10Nm is applied on the upper face of L1. A finite element (FE) model composed of L1 to L5 lumbar spines was generated to verify the mechanical integrity and the dynamic stability of the designed lumbar fixation device and to further optimize the lumbar fixation device. The FE model generated above produced the same pressure value on intervertebral disc and dynamic behavior as the normal intact model reported in the literature. The consistent results from this comparison validates the accuracy in the modeling of the current FE model. Currently, we are trying to generate an abnormal model with defects in one or more components of the normal FE model above. Then, the mechanical integrity and the dynamic stability of the designed lumbar fixation device will be analyzed after being installed in the abnormal model and then the lumbar fixation device will be further optimized.

Keywords: lumbar interspinous process fixation device, finite element method, lumbar spine, kinematics

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1312 Efficacy Of Tranexamic Acid On Blood Loss After Primary Total Hip Replacement : A Case-control Study In 154 Patients

Authors: Fedili Benamar, Belloulou Mohamed Lamine, Ouahes Hassane, Ghattas Samir

Abstract:

Introduction: Perioperative blood loss is a frequent cause of complications in total hip replacement (THR). The present prospective study assessed the efficacy of tranexamic acid (Exacyl(®)) in reducing blood loss in primary THR. Hypothesis: Tranexamic acid reduces blood loss in THR. Material and method: -This is a prospective randomized study on the effectiveness of Exacyl (tranexamic acid) in total hip replacement surgery performed on a standardized technique between 2019 and September 2022. -It involved 154 patients, of which 84 received a single injection of Exacyl (group 1) at a dosage of 10 mg/kg over 20 minutes during the perioperative period. -All patients received postoperative thromboprophylaxis with enoxaparin 0.4 ml subcutaneously. -All patients were admitted to the post-interventional intensive care unit for a duration of 24 hours for monitoring and pain management as per the service protocol. Results: 154 patients, of which 84 received a single injection of Exacyl (group 1) and 70 patients patients who did not receive Exacyl perioperatively : (Group 2 ) The average age is 57 +/- 15 years The distribution by gender was nearly equal with 56% male and 44% female; "The distribution according to the ASA score was as follows: 20.2% ASA1, 82.3% ASA2, and 17.5% ASA3. "There was a significant difference in the average volume of intraoperative and postoperative bleeding during the 48 hours." The average bleeding volume for group 1 (received Exacyl) was 614 ml +/- 228, while the average bleeding volume for group 2 was 729 +/- 300, with a chi-square test of 6.35 and a p-value < 0.01, which is highly significant. The ANOVA test showed an F-statistic of 7.11 and a p-value of 0.008. A Bartlett test revealed a chi-square of 6.35 and a p-value < 0.01." "In Group 1 (patients who received Exacyl), 73% had bleeding less than 750 ml (Group A), and 26% had bleeding exceeding 750 ml (Group B). In Group 2 (patients who did not receive Exacyl perioperatively), 52% had bleeding less than 750 ml (Group A), and 47% had bleeding exceeding 750 ml (Group B). "Thus, the use of Exacyl reduced perioperative bleeding and specifically decreased the risk of severe bleeding exceeding 750 ml by 43% with a relative risk (RR) of 1.37 and a p-value < 0.01. The transfusion rate was 1.19% in the population of Group 1 (Exacyl), whereas it was 10% in the population of Group 2 (no Exacyl). It can be stated that the use of Exacyl resulted in a reduction in perioperative blood transfusion with an RR of 0.1 and a p-value of 0.02. Conclusions: The use of Exacyl significantly reduced perioperative bleeding in this type of surgery.

Keywords: acid tranexamic, blood loss, anesthesia, total hip replacement, surgery

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1311 Management of Acute Biliary Pathology at Gozo General Hospital

Authors: Kristian Bugeja, Upeshala A. Jayawardena, Clarissa Fenech, Mark Zammit Vincenti

Abstract:

Introduction: Biliary colic, acute cholecystitis, and gallstone pancreatitis are some of the most common surgical presentations at Gozo General Hospital (GGH). National Institute for Health and Care Excellence (NICE) guidelines advise that suitable patients with acute biliary problems should be offered a laparoscopic cholecystectomy within one week of diagnosis. There has traditionally been difficulty in achieving this mainly due to the reluctance of some surgeons to operate in the acute setting, limited, timely access to MRCP and ERCP, and organizational issues. Methodology: A retrospective study was performed involving all biliary pathology-related admissions to GGH during the two-year period of 2019 and 2020. Patients’ files and electronic case summary (ECS) were used for data collection, which included demographic data, primary diagnosis, co-morbidities, management, waiting time to surgery, length of stay, readmissions, and reason for readmissions. NICE clinical guidance 188 – Gallstone disease were used as the standard. Results: 51 patients were included in the study. The mean age was 58 years, and 35 (68.6%) were female. The main diagnoses on admission were biliary colic in 31 (60.8%), acute cholecystitis in 10 (19.6%). Others included gallstone pancreatitis in 3 (5.89%), chronic cholecystitis in 2 (3.92%), gall bladder malignancy in 4 (7.84%), and ascending cholangitis in 1 (1.97%). Management included laparoscopic cholecystectomy in 34 (66.7%); conservative in 8 (15.7%) and ERCP in 6 (11.7%). The mean waiting time for laparoscopic cholecystectomy for patients with acute cholecystitis was 74 days – range being between 3 and 146 days since the date of diagnosis. Only one patient who was diagnosed with acute cholecystitis and managed with laparoscopic cholecystectomy was done so within the 7-day time frame. Hospital re-admissions were reported in 5 patients (9.8%) due to vomiting (1), ascending cholangitis (1), and gallstone pancreatitis (3). Discussion: Guidelines were not met for patients presenting to Gozo General Hospital with acute biliary pathology. This resulted in 5 patients being re-admitted to hospital while waiting for definitive surgery. The local issues resulting in the delay to surgery need to be identified and steps are taken to facilitate the provision of urgent cholecystectomy for suitable patients.

Keywords: biliary colic, acute cholecystits, laparoscopic cholecystectomy, conservative management

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1310 Replacement of the Distorted Dentition of the Cone Beam Computed Tomography Scan Models for Orthognathic Surgery Planning

Authors: T. Almutairi, K. Naudi, N. Nairn, X. Ju, B. Eng, J. Whitters, A. Ayoub

Abstract:

Purpose: At present Cone Beam Computed Tomography (CBCT) imaging does not record dental morphology accurately due to the scattering produced by metallic restorations and the reported magnification. The aim of this pilot study is the development and validation of a new method for the replacement of the distorted dentition of CBCT scans with the dental image captured by the digital intraoral camera. Materials and Method: Six dried skulls with orthodontics brackets on the teeth were used in this study. Three intra-oral markers made of dental stone were constructed which were attached to orthodontics brackets. The skulls were CBCT scanned, and occlusal surface was captured using TRIOS® 3D intraoral scanner. Marker based and surface based registrations were performed to fuse the digital intra-oral scan(IOS) into the CBCT models. This produced a new composite digital model of the skull and dentition. The skulls were scanned again using the commercially accurate Laser Faro® arm to produce the 'gold standard' model for the assessment of the accuracy of the developed method. The accuracy of the method was assessed by measuring the distance between the occlusal surfaces of the new composite model and the 'gold standard' 3D model of the skull and teeth. The procedure was repeated a week apart to measure the reproducibility of the method. Results: The results showed no statistically significant difference between the measurements on the first and second occasions. The absolute mean distance between the new composite model and the laser model ranged between 0.11 mm to 0.20 mm. Conclusion: The dentition of the CBCT can be accurately replaced with the dental image captured by the intra-oral scanner to create a composite model. This method will improve the accuracy of orthognathic surgical prediction planning, with the final goal of the fabrication of a physical occlusal wafer without to guide orthognathic surgery and eliminate the need for dental impression.

Keywords: orthognathic surgery, superimposition, models, cone beam computed tomography

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1309 Energy Production with Closed Methods

Authors: Bujar Ismaili, Bahti Ismajli, Venhar Ismaili, Skender Ramadani

Abstract:

In Kosovo, the problem with the electricity supply is huge and does not meet the demands of consumers. Older thermal power plants, which are regarded as big environmental polluters, produce most of the energy. Our experiment is based on the production of electricity using the closed method that does not affect environmental pollution by using waste as fuel that is considered to pollute the environment. The experiment was carried out in the village of Godanc, municipality of Shtime - Kosovo. In the experiment, a production line based on the production of electricity and central heating was designed at the same time. The results are the benefits of electricity as well as the release of temperature for heating with minimal expenses and with the release of 0% gases into the atmosphere. During this experiment, coal, plastic, waste from wood processing, and agricultural wastes were used as raw materials. The method utilized in the experiment allows for the release of gas through pipes and filters during the top-to-bottom combustion of the raw material in the boiler, followed by the method of gas filtration from waste wood processing (sawdust). During this process, the final product is obtained - gas, which passes through the carburetor, which enables the gas combustion process and puts into operation the internal combustion machine and the generator and produces electricity that does not release gases into the atmosphere. The obtained results show that the system provides energy stability without environmental pollution from toxic substances and waste, as well as with low production costs. From the final results, it follows that: in the case of using coal fuel, we have benefited from more electricity and higher temperature release, followed by plastic waste, which also gave good results. The results obtained during these experiments prove that the current problems of lack of electricity and heating can be met at a lower cost and have a clean environment and waste management.

Keywords: energy, heating, atmosphere, waste, gasification

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1308 Assessing the Impact of Frailty in Elderly Patients Undergoing Emergency Laparotomies in Singapore

Authors: Zhao Jiashen, Serene Goh, Jerry Goo, Anthony Li, Lim Woan Wui, Paul Drakeford, Chen Qing Yan

Abstract:

Introduction: Emergency laparotomy (EL) is one of the most common surgeries done in Singapore to treat acute abdominal pathologies. A significant proportion of these surgeries are performed in the geriatric population (65 years and older), who tend to have the highest postoperative morbidity, mortality, and highest utilization of intensive care resources. Frailty, the state of vulnerability to adverse outcomes from an accumulation of physiological deficits, has been shown to be associated with poorer outcomes after surgery and remains a strong driver of healthcare utilization and costs. To date, there is little understanding of the impact it has on emergency laparotomy outcomes. The objective of this study is to examine the impact of frailty on postoperative morbidity, mortality, and length of stay after EL. Methods: A retrospective study was conducted in two tertiary centres in Singapore, Tan Tock Seng Hospital and Khoo Teck Puat Hospital the period from January to December 2019. Patients aged 65 years and above who underwent emergency laparotomy for intestinal obstruction, perforated viscus, bowel ischaemia, adhesiolysis, gastrointestinal bleed, or another suspected acute abdomen were included. Laparotomies performed for trauma, cholecystectomy, appendectomy, vascular surgery, and non-GI surgery were excluded. The Clinical Frailty Score (CFS) developed by the Canadian Study of Health and Aging (CSHA) was used. A score of 1 to 4 was defined as non-frail and 5 to 7 as frail. We compared the clinical outcomes of elderly patients in the frail and non-frail groups. Results: There were 233 elderly patients who underwent EL during the study period. Up to 26.2% of patients were frail. Patients who were frail (CFS 5-9) tend to be older, 79 ± 7 vs 79 ± 5 years of age, p <0.01. Gender distribution was equal in both groups. Indication for emergency laparotomies, time from diagnosis to surgery, and presence of consultant surgeons and anaesthetists in the operating theatre were comparable (p>0.05). Patients in the frail group were more likely to receive postoperative geriatric assessment than in the non-frail group, 49.2% vs. 27.9% (p<0.01). The postoperative complications were comparable (p>0.05). The length of stay in the critical care unit was longer for the frail patients, 2 (IQR 1-6.5) versus 1 (IQR 0-4) days, p<0.01. Frailty was found to be an independent predictor of 90-day mortality but not age, OR 2.9 (1.1-7.4), p=0.03. Conclusion: Up to one-fourth of the elderly who underwent EL were frail. Patients who were frail were associated with a longer length of stay in the critical care unit and a 90-day mortality rate of more than three times that of their non-frail counterparts. PPOSSUM was a better predictor of 90-day mortality in the non-frail group than in the frail group. As frailty scoring was a significant predictor of 90-day mortality, its integration into acute surgical units to facilitate shared decision-making and discharge planning should be considered.

Keywords: frailty elderly, emergency, laparotomy

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1307 Autologous Blood for Conjunctival Autograft Fixation in Primary Pterygium Surgery: a Systematic Review and Meta-Analysis

Authors: Mohamed Abdelmongy

Abstract:

Autologous Blood for Conjunctival Autograft Fixation in Primary Pterygium Surgery: A Systematic Review and Meta-analysis Hossam Zein1,2, Ammar Ismail1,3, Mohamed Abdelmongy1,4, Sherif Elsherif1,5,6, Ahmad Hassanen1,4, Basma Muhammad2, Fathy Assaf1,3, Ahmed Elsehili1,7, Ahmed Negida1,7, Shin Yamane9, Mohamed M. Abdel-Daim8,9 and Kazuaki Kadonosono9 https://www.ncbi.nlm.nih.gov/pubmed/30277146 BACKGROUND: Pterygium is a benign ocular lesion characterized by triangular fibrovascular growth of conjunctival tissue over the cornea. Patients complain of the bad cosmetic appearance, ocular surface irritation and decreased visual acuity if the pterygium is large enough to cause astigmatism or encroach on the pupil. The definitive treatment of pterygium is surgical removal. However, outcomes are compromised by recurrence . The aim of the current study is to systematically review the current literature to explore the efficacy and safety of fibrin glue, suture and autologous blood coagulum for conjunctivalautograft fixation in primary pterygium surgery. OBJECTIVES: To assess the effectiveness of fibrin glue compared to sutures and autologous blood coagulum in conjunctival autografting for the surgical treatment of pterygium. METHODS: During preparing this manuscript, we followed the steps adequately illustrated in the Cochrane Handbook for Systematic Reviews of Interventions version 5.3, and reported it according to the preferred reporting of systematic review and meta-analysis (PRISMA) statement guidelines. We searched PubMed, Ovid (both through Medline), ISI Web of Science, and Cochrane Central Register of Controlled Trials (Central) through January 2017, using the following keywords “Pterygium AND (blood OR glue OR suture)” SELECTION CRITERIA: We included all randomized controlled trials (RCTs) that met the following criteria: 1) comparing autologous blood vs fibrin glue for conjunctivalautograft fixation in primary pterygium surgery 2) comparing autologous blood vs sutures for conjunctivalautograft fixation in primary pterygium surgery DATA COLLECTION AND ANALYSIS: Two review authors independently screened the search results, assessed trial quality, and extracted data using standard methodological procedures expected by Cochrane. The extracted data included A) study design, sample size, and main findings, B) Baseline characteristics of patients included in this review including their age, sex, pterygium site and grade, and graft size. C) Study outcomes comprising 1) primary outcomes: recurrence rate 2) secondary outcomes: graft stability outcomes (graft retraction, graft displacement), operation time (min) and postoperative symptoms (pain, discomfort, foreign body sensation, tearing) MAIN RESULTS: We included 7 RCTs and The review included662eyes (Blood: 293; Glue: 198; Suture: 171). we assess the 1) primary outcomes: recurrence rate 2) secondary outcomes: graft stability outcomes (graft retraction, graft displacement), operation time (min) and postoperative symptoms (pain, discomfort, foreign body sensation, tearing) CONCLUSIONS: Autologous blood for conjunctivalautograft fixation in pterygium surgery is associated with lower graft stability than fibrin glue or sutures. It was not inferior to fibrin glue or sutures regarding recurrence rate. The overall quality of evidence is low. Further well designed RCTs are needed to fully explore the efficacy of this new technique.

Keywords: pterygium, autograft, ophthalmology, cornea

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1306 The Accuracy of an In-House Developed Computer-Assisted Surgery Protocol for Mandibular Micro-Vascular Reconstruction

Authors: Christophe Spaas, Lies Pottel, Joke De Ceulaer, Johan Abeloos, Philippe Lamoral, Tom De Backer, Calix De Clercq

Abstract:

We aimed to evaluate the accuracy of an in-house developed low-cost computer-assisted surgery (CAS) protocol for osseous free flap mandibular reconstruction. All patients who underwent primary or secondary mandibular reconstruction with a free (solely or composite) osseous flap, either a fibula free flap or iliac crest free flap, between January 2014 and December 2017 were evaluated. The low-cost protocol consisted out of a virtual surgical planning, a prebend custom reconstruction plate and an individualized free flap positioning guide. The accuracy of the protocol was evaluated through comparison of the postoperative outcome with the 3D virtual planning, based on measurement of the following parameters: intercondylar distance, mandibular angle (axial and sagittal), inner angular distance, anterior-posterior distance, length of the fibular/iliac crest segments and osteotomy angles. A statistical analysis of the obtained values was done. Virtual 3D surgical planning and cutting guide design were performed with Proplan CMF® software (Materialise, Leuven, Belgium) and IPS Gate (KLS Martin, Tuttlingen, Germany). Segmentation of the DICOM data as well as outcome analysis were done with BrainLab iPlan® Software (Brainlab AG, Feldkirchen, Germany). A cost analysis of the protocol was done. Twenty-two patients (11 fibula /11 iliac crest) were included and analyzed. Based on voxel-based registration on the cranial base, 3D virtual planning landmark parameters did not significantly differ from those measured on the actual treatment outcome (p-values >0.05). A cost evaluation of the in-house developed CAS protocol revealed a 1750 euro cost reduction in comparison with a standard CAS protocol with a patient-specific reconstruction plate. Our results indicate that an accurate transfer of the planning with our in-house developed low-cost CAS protocol is feasible at a significant lower cost.

Keywords: CAD/CAM, computer-assisted surgery, low-cost, mandibular reconstruction

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1305 Act Local, Think Global: Superior Institute of Engineering of Porto Campaign for a Sustainable Campus

Authors: R. F. Mesquita Brandão

Abstract:

Act Local, Think Global is the name of a campaign implemented at Superior Institute of Engineering of Porto (ISEP), one of schools of Polytechnic of Porto, with the main objective of increase the sustainability of the campus. ISEP has a campus with 52.000 m2 and more than 7.000 students. The campaign started in 2019 and the results are very clear. In 2019 only 16% of the waste created in the campus was correctly separate for recycling and now almost 50% of waste goes to the correct waste container. Actions to reduce the energy consumption were implemented with significantly results. One of the major problems in the campus are the water leaks. To solve this problem was implemented a methodology for water monitoring during the night, a period of time where consumptions are normally low. If water consumption in the period is higher than a determinate value it may mean a water leak and an alarm is created to the maintenance teams. In terms of energy savings, some measurements were implemented to create savings in energy consumption and in equivalent CO₂ produced. In order to reduce the use of plastics in the campus, was implemented the prohibition of selling 33 cl plastic water bottles and in collaboration with the students association all meals served in the restaurants changed the water plastic bottle for a glass that can be refilled with water in the water dispensers. This measures created a reduction of use of more than 75.000 plastic bottles per year. In parallel was implemented the ISEP water glass bottle to be used in all scientific meetings and events. Has a way of involving all community in sustainability issues was developed and implemented a vertical garden in aquaponic system. In 2019, the first vertical garden without soil was installed inside a large campus building. The system occupies the entire exterior façade (3 floors) of the entrance to ISEP's G building. On each of these floors there is a planter with 42 positions available for plants. Lettuces, strawberries, peppers are examples of some vegetable produced that can be collected by the entire community. Associated to the vertical garden was developed a monitoring system were some parameters of the system are monitored. This project is under development because it will work in a stand-alone energy feeding, with the use of photovoltaic panels for production of energy necessities. All the system was, and still is, developed by students and teachers and is used in class projects of some ISEP courses. These and others measures implemented in the campus, will be more developed in the full paper, as well as all the results obtained, allowed ISEP to be the first Portuguese high school to obtain the certification “Coração Verde” (Green Heart), awarded by LIPOR, a Portuguese company with the mission of transform waste into new resources through the implementation of innovative and circular practices, generating and sharing value.

Keywords: aquaponics, energy efficiency, recycling, sustainability, waste separation

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1304 Design and Fabrication of a Programmable Stiffness-Sensitive Gripper for Object Handling

Authors: Mehdi Modabberifar, Sanaz Jabary, Mojtaba Ghodsi

Abstract:

Stiffness sensing is an important issue in medical diagnostic, robotics surgery, safe handling, and safe grasping of objects in production lines. Detecting and obtaining the characteristics in dwelling lumps embedded in a soft tissue and safe removing and handling of detected lumps is needed in surgery. Also in industry, grasping and handling an object without damaging in a place where it is not possible to access a human operator is very important. In this paper, a method for object handling is presented. It is based on the use of an intelligent gripper to detect the object stiffness and then setting a programmable force for grasping the object to move it. The main components of this system includes sensors (sensors for measuring force and displacement), electrical (electrical and electronic circuits, tactile data processing and force control system), mechanical (gripper mechanism and driving system for the gripper) and the display unit. The system uses a rotary potentiometer for measuring gripper displacement. A microcontroller using the feedback received by the load cell, mounted on the finger of the gripper, calculates the amount of stiffness, and then commands the gripper motor to apply a certain force on the object. Results of Experiments on some samples with different stiffness show that the gripper works successfully. The gripper can be used in haptic interfaces or robotic systems used for object handling.

Keywords: gripper, haptic, stiffness, robotic

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1303 Investigation of a Single Feedstock Particle during Pyrolysis in Fluidized Bed Reactors via X-Ray Imaging Technique

Authors: Stefano Iannello, Massimiliano Materazzi

Abstract:

Fluidized bed reactor technologies are one of the most valuable pathways for thermochemical conversions of biogenic fuels due to their good operating flexibility. Nevertheless, there are still issues related to the mixing and separation of heterogeneous phases during operation with highly volatile feedstocks, including biomass and waste. At high temperatures, the volatile content of the feedstock is released in the form of the so-called endogenous bubbles, which generally exert a “lift” effect on the particle itself by dragging it up to the bed surface. Such phenomenon leads to high release of volatile matter into the freeboard and limited mass and heat transfer with particles of the bed inventory. The aim of this work is to get a better understanding of the behaviour of a single reacting particle in a hot fluidized bed reactor during the devolatilization stage. The analysis has been undertaken at different fluidization regimes and temperatures to closely mirror the operating conditions of waste-to-energy processes. Beechwood and polypropylene particles were used to resemble the biomass and plastic fractions present in waste materials, respectively. The non-invasive X-ray technique was coupled to particle tracking algorithms to characterize the motion of a single feedstock particle during the devolatilization with high resolution. A high-energy X-ray beam passes through the vessel where absorption occurs, depending on the distribution and amount of solids and fluids along the beam path. A high-speed video camera is synchronised to the beam and provides frame-by-frame imaging of the flow patterns of fluids and solids within the fluidized bed up to 72 fps (frames per second). A comprehensive mathematical model has been developed in order to validate the experimental results. Beech wood and polypropylene particles have shown a very different dynamic behaviour during the pyrolysis stage. When the feedstock is fed from the bottom, the plastic material tends to spend more time within the bed than the biomass. This behaviour can be attributed to the presence of the endogenous bubbles, which drag effect is more pronounced during the devolatilization of biomass, resulting in a lower residence time of the particle within the bed. At the typical operating temperatures of thermochemical conversions, the synthetic polymer softens and melts, and the bed particles attach on its outer surface, generating a wet plastic-sand agglomerate. Consequently, this additional layer of sand may hinder the rapid evolution of volatiles in the form of endogenous bubbles, and therefore the establishment of a poor drag effect acting on the feedstock itself. Information about the mixing and segregation of solid feedstock is of prime importance for the design and development of more efficient industrial-scale operations.

Keywords: fluidized bed, pyrolysis, waste feedstock, X-ray

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1302 Effect of Flux Salts on the Recovery Extent and Quality of Metal Values from Spent Rechargeable Lead Batteries

Authors: Mahmoud A Rabah, Sabah M. Abelbasir

Abstract:

Lead-calcium alloy containing up to 0.10% calcium was recovered from spent rechargeable sealed acid lead batteries. Two techniques were investigated to explore the effect of flux salts on the extent and quality of the recovered alloy, pyro-metallurgical and electrochemical methods. About 10 kg of the spent batteries were collected for testing. The sample was washed with hot water and dried. The plastic cases of the batteries were mechanically cut, and the contents were dismantled manually, the plastic containers were shredded for recycling. The electrode plates were freed from the loose powder and placed in SiC crucible and covered with alkali chloride salts. The loaded crucible was heated in an electronically controlled chamber furnace type Nabertherm C3 at temperatures up to 800 °C. The obtained metals were analyzed. The effect of temperature, rate of heating, atmospheric conditions, composition of the flux salts on the extent and quality of the recovered products were studied. Results revealed that the spent rechargeable batteries contain 6 blocks of 6 plates of Pb-Ca alloy each. Direct heating of these plates in a silicon carbide crucible under ambient conditions produces lead metal poor in calcium content ( < 0.07%) due to partial oxidation of the alloying calcium element. Rate of temperature increase has a considerable effect on the yield of the lead alloy extraction. Flux salts composition benefits the recovery process. Sodium salts are more powerful as compared to potassium salts. Lead calcium alloy meeting the standard specification was successfully recovered from the spent rechargeable acid lead batteries with a very competitive cost to the same alloy prepared from primary resources.

Keywords: rechargeable lead batteries, lead-calcium alloy, waste recovery, flux salts, thermal recovery

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1301 Malignancy in Venous Thromboembolism

Authors: Naser Shagerdi Esmaeli, Mohsen Hamidpour

Abstract:

Purposes: The activation of coagulation in patients with cancer contributes significantly to morbidity and mortality rates and may play a fundamental role in the host response to growing tumor’s. Patients with cancer are clearly at high risk for the development of venous thromboembolism (VTE), particularly during chemotherapy and surgery. This situation is aggravated by the use of venous access catheters and possibly growth factors. Methods: Data derived from large, randomized, controlled trials have been used to determine the true incidence of this complication of cancer and its treatment. The incidence based on the analyses of these randomized controlled trials varies from 1% for limited stage patients with breast cancer treated with tamoxifen to 60% for patients with any type of cancer who are subjected to orthopedic surgery and do not receive prophylactic therapy. Results: In view of the morbidity and mortality attributable to VTE in cancer, widespread utilization of prophylactic anticoagulation therapy, which has proven safe and effective in a variety of situations, should be considered. While migratory thrombophlebitis is a clear indicator of an underlying neoplasm, the risk of cancer in patients with the more typical form of VTE has been the subject of intense debate over recent years. Conclusion: Some investigators have suggested that the relative risk of being diagnosed with occult cancer within six months of an episode of VTE (particularly recurrent VTE) could be up to 10-fold. However, the cost-effectiveness of aggressive screening for cancer in patients with VTE has not yet been defined adequately.

Keywords: venous thromboembolism, malignancy, cancer, tumor, heparin

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1300 Comparison of Quality of Life One Year after Bariatric Intervention: Systematic Review of the Literature with Bayesian Network Meta-Analysis

Authors: Piotr Tylec, Alicja Dudek, Grzegorz Torbicz, Magdalena Mizera, Natalia Gajewska, Michael Su, Tanawat Vongsurbchart, Tomasz Stefura, Magdalena Pisarska, Mateusz Rubinkiewicz, Piotr Malczak, Piotr Major, Michal Pedziwiatr

Abstract:

Introduction: Quality of life after bariatric surgery is an important factor when evaluating the final result of the treatment. Considering the vast surgical options, we tried to globally compare available methods in terms of quality of following the surgery. The aim of the study is to compare the quality of life a year after bariatric intervention using network meta-analysis methods. Material and Methods: We performed a systematic review according to PRISMA guidelines with Bayesian network meta-analysis. Inclusion criteria were: studies comparing at least two methods of weight loss treatment of which at least one is surgical, assessment of the quality of life one year after surgery by validated questionnaires. Primary outcomes were quality of life one year after bariatric procedure. The following aspects of quality of life were analyzed: physical, emotional, general health, vitality, role physical, social, mental, and bodily pain. All questionnaires were standardized and pooled to a single scale. Lifestyle intervention was considered as a referenced point. Results: An initial reference search yielded 5636 articles. 18 studies were evaluated. In comparison of total score of quality of life, we observed that laparoscopic sleeve gastrectomy (LSG) (median (M): 3.606, Credible Interval 97.5% (CrI): 1.039; 6.191), laparoscopic Roux en-Y gastric by-pass (LRYGB) (M: 4.973, CrI: 2.627; 7.317) and open Roux en-Y gastric by-pass (RYGB) (M: 9.735, CrI: 6.708; 12.760) had better results than other bariatric intervention in relation to lifestyle interventions. In the analysis of the physical aspects of quality of life, we notice better results in LSG (M: 3.348, CrI: 0.548; 6.147) and in LRYGB procedure (M: 5.070, CrI: 2.896; 7.208) than control intervention, and worst results in open RYGB (M: -9.212, CrI: -11.610; -6.844). Analyzing emotional aspects, we found better results than control intervention in LSG, in LRYGB, in open RYGB, and laparoscopic gastric plication. In general health better results were in LSG (M: 9.144, CrI: 4.704; 13.470), in LRYGB (M: 6.451, CrI: 10.240; 13.830) and in single-anastomosis gastric by-pass (M: 8.671, CrI: 1.986; 15.310), and worst results in open RYGB (M: -4.048, CrI: -7.984; -0.305). In social and vital aspects of quality of life, better results were observed in LSG and LRYGB than control intervention. We did not find any differences between bariatric interventions in physical role, mental and bodily aspects of quality of life. Conclusion: The network meta-analysis revealed that better quality of life in total score one year after bariatric interventions were after LSG, LRYGB, open RYGB. In physical and general health aspects worst quality of life was in open RYGB procedure. Other interventions did not significantly affect the quality of life after a year compared to dietary intervention.

Keywords: bariatric surgery, network meta-analysis, quality of life, one year follow-up

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1299 Plastic Pellets in Santa Cruz Dos Navegantes Beach, Brazil, in the Winter of 2019

Authors: Victor Vasques Ribeiro

Abstract:

The Santa Cruz dos Navegantes beach is located in the city of Guarujá, in the central portion of the coast of the state of São Paulo. Next to this beach is located the Channel of the Port of Santos, configured as a source of plastic pellets for marine environments. On sandy beaches near the sources, especially during the winter and after cold front entrance events, the amounts of pellets can be very high. This study aimed to determine the influence of a cold front entry event of the winter of 2019 on the amount of pellets found on Santa Cruz dos Navegantes beach, besides assuming the proximity of the sources. During six consecutive collection campaigns, three of which were previous and three after the cold front entry peak, 30.0 square meters of surface sediments were sampled in each campaign. The color and shape of the pellets were determined to assume the length of the permanence of these granules in the marine environment and, consequently, the proximity of the sources. This beach was considered ideal for this type of research. The pellet pollution index (PPI) was from moderate to very high right after the peak of the cold front entry. The cold front peak event significantly influenced the amount of pellets found on the beach of Santa Cruz dos Navegantes. The factors that can bury the pellets in the sediments were classified as low when compared to other beaches in the region. Most of the pellets found were recently produced and lost to aquatic environments. Like the other beaches near Santos Bay, Santa Cruz dos Navegantes beach receives significant amounts of pellets that have nearby origins. Therefore, it was supposed that the activities of the Santos port complex are sources of pellets for the marine environment. This pollution can be further worsened in certain meteoceanographic events. The beaches of this region need to be constantly monitored and evaluated for pollution by pellets.

Keywords: beach, cold front, pellets, sources

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