Search results for: chronic mechanical low back pain
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 7143

Search results for: chronic mechanical low back pain

3273 Preparation and Properties of Polylactic Acid/MDI Modified Thermoplastic Starch Blends

Authors: Sukhila Krishnan, Smita Mohanty, Sanjay K. Nayak

Abstract:

Polylactide (PLA) and thermoplastic starch (TPS) are the most promising bio-based materials presently available on the market. Polylactic acid is one of the versatile biodegradable polyester showing wide range of applications in various fields and starch is a biopolymer which is renewable, cheap as well as extensively available. The usual increase in the cost of petroleum-based commodities in the next decades opens bright future for these materials. Their biodegradability and compostability was an added advantage in applications that are difficult to recycle. Currently, thermoplastic starch (TPS) has been used as a substitute for synthetic plastic in several commercial products. But, TPS shows some limitations mainly due to its brittle and hydrophilic nature, which has to be resolved to widen its application.The objective of the work we report here was to initiate chemical modifications on TPS and to build up a process to control its chemical structure using a solution process which can reduce its water sensitive properties and then blended it with PLA to improve compatibility between PLA and TPS. The method involves in cleavage of starch amylose and amylopectin chain backbone to plasticize with glycerol and water in batch mixer and then the prepared TPS was reacted in solution with diisocyanates i.e, 4,4'-Methylenediphenyl Diisocyanate (MDI).This diisocyanate was used before with great success for the chemical modification of TPS surface. The method utilized here will form an urethane-linkages between reactive isocyanate groups (–NCO) and hydroxyl groups (-OH) of starch as well as of glycerol. New polymer synthesised shows a reduced crystallinity, less hydrophilic and enhanced compatibility with other polymers. The TPS was prepared by Haake Rheomix 600 batch mixer with roller rotors operating at 50 rpm. The produced material is then refluxed for 5hrs with MDI in toluene with constant stirring. Finally, the modified TPS was melt blended with PLA in different compositions. Blends obtained shows an improved mechanical properties. These materials produced are characterized by Fourier Transform Infrared Spectra (FTIR), DSC, X-Ray diffraction and mechanical tests.

Keywords: polylactic acid, thermoplastic starch, Methylenediphenyl Diisocyanate, Polylactide (PLA)

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3272 Study of Error Analysis and Sources of Uncertainty in the Measurement of Residual Stresses by the X-Ray Diffraction

Authors: E. T. Carvalho Filho, J. T. N. Medeiros, L. G. Martinez

Abstract:

Residual stresses are self equilibrating in a rigid body that acts on the microstructure of the material without application of an external load. They are elastic stresses and can be induced by mechanical, thermal and chemical processes causing a deformation gradient in the crystal lattice favoring premature failure in mechanicals components. The search for measurements with good reliability has been of great importance for the manufacturing industries. Several methods are able to quantify these stresses according to physical principles and the response of the mechanical behavior of the material. The diffraction X-ray technique is one of the most sensitive techniques for small variations of the crystalline lattice since the X-ray beam interacts with the interplanar distance. Being very sensitive technique is also susceptible to variations in measurements requiring a study of the factors that influence the final result of the measurement. Instrumental, operational factors, form deviations of the samples and geometry of analyzes are some variables that need to be considered and analyzed in order for the true measurement. The aim of this work is to analyze the sources of errors inherent to the residual stress measurement process by X-ray diffraction technique making an interlaboratory comparison to verify the reproducibility of the measurements. In this work, two specimens were machined, differing from each other by the surface finishing: grinding and polishing. Additionally, iron powder with particle size less than 45 µm was selected in order to be a reference (as recommended by ASTM E915 standard) for the tests. To verify the deviations caused by the equipment, those specimens were positioned and with the same analysis condition, seven measurements were carried out at 11Ψ tilts. To verify sample positioning errors, seven measurements were performed by positioning the sample at each measurement. To check geometry errors, measurements were repeated for the geometry and Bragg Brentano parallel beams. In order to verify the reproducibility of the method, the measurements were performed in two different laboratories and equipments. The results were statistically worked out and the quantification of the errors.

Keywords: residual stress, x-ray diffraction, repeatability, reproducibility, error analysis

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3271 Geomechanical Numerical Modeling of Well Wall in Drilling with Finite Difference Method

Authors: Marzieh Zarei

Abstract:

Well instability is one of the most fundamental challenges faced by the oil and gas industry. Well wall stability analysis is a gap to be filled in the oil industry. The collection of static data such as well logging leads to the construction of a geomechanical numerical model, which will help in assessing the probable risks in future drilling. In this paper, geomechanical model was designed, and mechanical properties of the rock was determined at all points of the model. It was found the safe mud window was determined and the minimum and maximum mud pressures were determined in the ranges of 70-60 MPa and 110-100 MPa, respectively.

Keywords: geomechanics, numerical model, well stability, in-situ stress, underbalanced drilling

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3270 Technical and Economic Analysis of Smart Micro-Grid Renewable Energy Systems: An Applicable Case Study

Authors: M. A. Fouad, M. A. Badr, Z. S. Abd El-Rehim, Taher Halawa, Mahmoud Bayoumi, M. M. Ibrahim

Abstract:

Renewable energy-based micro-grids are presently attracting significant consideration. The smart grid system is presently considered a reliable solution for the expected deficiency in the power required from future power systems. The purpose of this study is to determine the optimal components sizes of a micro-grid, investigating technical and economic performance with the environmental impacts. The micro grid load is divided into two small factories with electricity, both on-grid and off-grid modes are considered. The micro-grid includes photovoltaic cells, back-up diesel generator wind turbines, and battery bank. The estimated load pattern is 76 kW peak. The system is modeled and simulated by MATLAB/Simulink tool to identify the technical issues based on renewable power generation units. To evaluate system economy, two criteria are used: the net present cost and the cost of generated electricity. The most feasible system components for the selected application are obtained, based on required parameters, using HOMER simulation package. The results showed that a Wind/Photovoltaic (W/PV) on-grid system is more economical than a Wind/Photovoltaic/Diesel/Battery (W/PV/D/B) off-grid system as the cost of generated electricity (COE) is 0.266 $/kWh and 0.316 $/kWh, respectively. Considering the cost of carbon dioxide emissions, the off-grid will be competitive to the on-grid system as COE is found to be (0.256 $/kWh, 0.266 $/kWh), for on and off grid systems.

Keywords: renewable energy sources, micro-grid system, modeling and simulation, on/off grid system, environmental impacts

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3269 Batch and Fixed-Bed Studies of Ammonia Treated Coconut Shell Activated Carbon for Adsorption of Benzene and Toluene

Authors: Jibril Mohammed, Usman Dadum Hamza, Muhammad Idris Misau, Baba Yahya Danjuma, Yusuf Bode Raji, Abdulsalam Surajudeen

Abstract:

Volatile organic compounds (VOCs) have been reported to be responsible for many acute and chronic health effects and environmental degradations such as global warming. In this study, a renewable and low-cost coconut shell activated carbon (PHAC) was synthesized and treated with ammonia (PHAC-AM) to improve its hydrophobicity and affinity towards VOCs. Removal efficiencies and adsorption capacities of the ammonia treated activated carbon (PHAC-AM) for benzene and toluene were carried out through batch and fixed-bed studies respectively. Langmuir, Freundlich and Tempkin adsorption isotherms were tested for the adsorption process and the experimental data were best fitted by Langmuir model and least fitted by Tempkin model; the favourability and suitability of fitness were validated by equilibrium parameter (RL) and the root square mean deviation (RSMD). Judging by the deviation of the predicted values from the experimental values, pseudo-second-order kinetic model best described the adsorption kinetics than the pseudo-first-order kinetic model for the two VOCs on PHAC and PHAC-AM. In the fixed-bed study, the effect of initial VOC concentration, bed height and flow rate on benzene and toluene adsorption were studied. The highest bed capacities of 77.30 and 69.40 mg/g were recorded for benzene and toluene respectively; at 250 mg/l initial VOC concentration, 2.5 cm bed height and 4.5 ml/min flow rate. The results of this study revealed that ammonia treated activate carbon (PHAC-AM) is a sustainable adsorbent for treatment of VOCs in polluted waters.

Keywords: volatile organic compounds, equilibrium and kinetics studies, batch and fixed bed study, bio-based activated carbon

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3268 Endoscopic Versus Open Treatment of Carpal Tunnel Syndrome: Postoperative Complications in Patients with Diabetes Mellitus

Authors: Arman Kishan, Mark Haft, Steve Li, Duc Nguyen, Dawn Laporte

Abstract:

Objective: Patients with Type 2 diabetes (T2DM) often face higher postoperative complication rates. Limited data exist on outcomes in T2DM patients undergoing carpal tunnel release (CTR). This study aims to compare complication rates between endoscopic CTR (ECTR) and open CTR (OCTR) in patients with T2DM. Methods: This was a retrospective cohort study using the TriNetX database of 56741 patients with T2DM undergoing ECTR (N= 14,949) or OCTR (N= 41,792). Demographic data, medical comorbidities, and complication rates were analyzed. We used multivariable analysis to identify differences in postoperative complication rates between the two treatment methods in patients with T2DM. Results: Patients with T2DM undergoing ECTR had a significantly lower incidence of 90-day wound infection (p < 0.001), 90-day wound dehiscence (p < 0.001), and nerve injury (p < 0.001) when compared to patients who underwent OCTR. After matching, there was a significantly higher number of T2DM patients undergoing ECTR who had peripheral vascular disease (p = 0.045) and hypertension (p = 0.020) when compared to the OCTR group. These patients also had a lower incidence of fluid and electrolyte disorders (p = 0.002) and chronic blood loss anemia (p = 0.025). Conclusion: ECTR presents a superior choice for T2DM patients undergoing CTR, yielding significantly lower rates of wound infection, wound dehiscence, and nerve injury within 90 days post-surgery—reducing the risk by 31%, 48%, and 59%, respectively. These findings support the adoption of ECTR as the preferred method in this patient population, potentially leading to improved postoperative outcomes.

Keywords: endoscopic treatment of carpal tunnel syndrome, open treatment of carpal tunnel syndrome, carpal tunnel syndrome, postoperative complications in patients with diabetes mellitus

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3267 The Role of Moroccan Salafist Radicalism in Creating Threat to Spain’s Security

Authors: Stanislaw Kosmynka

Abstract:

Although the genesis of the activity of fighting salafist radicalism in Spain dates back to the 80’s, the development of extremism of this kind manifested itself only in the next decade. Its first permanently functioning structures in this country in the second half of 90’s of 20th century came from Algieria and Syria. At the same time it should be emphasized that this distinction is in many dimensions conventional, the more so because they consisted also of immigrants from other coutries of Islam, particularly from Morocco. The paper seeks to understand the radical salafist challenge for Spain in the context of some terrorist networks consisted of immigrants from Morocco. On the eve of the new millennium Moroccan jihadists played an increasingly important role. Although the activity of these groups had for many years mainly logistical and propaganda character, the bomb attack carried out on 11 March 2004 in Madrid constituted an expression of open forms of terrorism, directed against the authorities and society of Spain and reflected the narration of representatives of the trend of the global jihad. The people involved in carrying out that act of violence were to a large extent Moroccan immigrants; also in the following years among the cells of radicals in Spain Moroccans stood out many times. That is why the forms and directions of activity of these extremists in Spain, also after 11th March 2004 and in the actual context of the impact of Islamic State, are worth presenting. The paper is focused on threats to the security of Spain and the region and remains connected with the issues of mutual relations of the society of a host country with immigrant communities which to a large degree come from this part of Maghreb.

Keywords: jihadi terrorism, Morocco, radical salafism, security, Spain, terrorist cells, threat

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3266 Physico-Mechanical Properties of Dir-Volcanics and Its Use as a Dimension Stone from Kohistan Island Arc, North Pakistan

Authors: Muhammad Nawaz, Waqas Ahmad

Abstract:

Dimension stone is used in construction since prehistoric time; however, its use in the construction has gained significant attention for the last few decades. The present study is designed to investigate the physical and strength properties of volcanic rocks from the Kohistan Island Arc to assess their use as dimension stone. On the basis of the composition, color and texture, five varieties of andesites (MMA, PMA-1, PMA-2, CMA and FMA) and two varieties of agglomerates (AG-1 and AG-2) were identified. These were characterized in terms of their petrography (compositional and textural), physical properties (specific gravity, water absorption, porosity) and strength properties (Unconfined compressive strength and Unconfined tensile strength). Two non-destructive tests (Ultrasonic pulse velocity test and Schmidt Hammer) were conducted and the degree of polishing was evaluated. In addition, correlation analyses were carried out to establish possible relationships among these parameters. The presence of chlorite, epidote, sericite and recrystallized quartz showed the signs of low-grade metamorphism in andesites. The results showed feldspar, amphibole and quartz imparted good physical and strength properties to the samples MMA, CMA, FMA, AG1 and AG2. Whereas, the abundance of alteration products such as chlorite, sericite and epidote in PMA-1 and PMA-2 reduced the physical and strength properties. The unconfined compressive strength showed a strong correlation with ultrasonic pulse velocity, dry density, porosity and water absorption. The values of ultrasonic pulse velocity and Schmidt hammer were considerably affected by the weathering grade. The samples PMA-1 and PMA-2, due to their high water absorption and low strength values, were not recommended for use in load-bearing masonry units and outdoor applications. Whereas, the excellent properties, i.e. high strength and good polishing, the samples, FMA and MMA suggested their use as a decorative and facing stone, in the external pavement, ashlar, rubbles and load-bearing masonry units etc.

Keywords: Physico-mechanical properties, Volcanic rocks, Kohistan Island Arc, Pakistan

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3265 Anterior Tooth Misalignment: Orthodontics or Restorative Treatment

Authors: Maryam Firouzmandi, Moosa Miri

Abstract:

Smile is considered to be one of the most effective methods of influencing people. Increasing numbers of patients are requesting cosmetic dental procedures to achieve the perfect smile. Based on the patient’s age, oral and facial characteristics, and the dentist’s expertise, different concepts of treatment would be available. Orthodontics is the most conservative and the ideal treatment alternative for crowded anterior teeth; however, it may be rejected by patients due to occupational limitations of time, physical discomfort including pain and functional limitations, psychological discomfort, and appearance during treatment. In addition, orthodontic treatment will not resolve deficits of contour and color of the anterior teeth. In consequence, patients may demand restorative techniques to resolve their anterior mal-alignment instead, often called "instant orthodontics". Following its introduction, however, adhesive dentistry has suffered at times from overuse. Creating short-term attractive smiles at the expense of long-term dental health and optimal tooth biomechanics by using cosmetic techniques should not be considered an ethical approach. The objective of this narrative review was to investigate the literature for guidelines with regard to decision making and treatment planning for anterior tooth mal-alignment. In this regard, indications of orthodontic, restorative, combination of both treatments, and adjunctive periodontal surgery were discussed in clinical cases to achieve a proportional smile. Restorative modalities would include disking, cosmetic contouring, veneers, and crowns and were compared with limited or comprehensive orthodontic options. A rapid review was also presented on pros and cons of snap on smile to mask malalignments. Diagnostic tools such as mock up, wax up, and digital smile design were also considered to achieve more conservative and functional treatments with respect to biologic factors.

Keywords: crowding, misalignment, veneer, crown, orthodontics

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3264 Mechanical and Durability Characteristics of Roller Compacted Geopolymer Concrete Using Recycled Concrete Aggregate

Authors: Syfur Rahman, Mohammad J. Khattak

Abstract:

Every year a huge quantity of recycling concrete aggregate (RCA) is generated in the United States of America. Utilization of RCA can solve the storage problem, prevent environmental pollution, and reduce the construction cost. However, due to the overall low strength and durability characteristics of RCA, its usages are limited to a certain area like a landfill, low strength base material, replacement of a few percentages of virgin aggregates in Portland cement concrete, etc. This study focuses on the improvement of the strength and durability characteristics of RCA by introducing the concept of roller-compacted geopolymer concrete. In this research, developed roller-compacted geopolymer concrete (RCGPC) and roller-compacted cement concrete (RCC) mixtures containing 100% recycled concrete aggregate were evaluated and compared. Several selected RCGPC mixtures were investigated to find out the effect of mixture variables, including sodium hydroxide (NaOH) molar concentration, sodium silicate (Na₂SiO₃), to sodium hydroxide (NaOH) ratio on the strength, stiffness and durability characteristics of the developed RCGPC. Sodium hydroxide (NaOH) and sodium silicate (Na₂SiO₃) were mixed in different ratios to synthesize the alkali activator. American Concrete Pavement Association (ACPA) recommended RCC gradation was used with a maximum nominal aggregate size of 19 mm with a 4% fine particle passing 0.075 mm sieve. The mixtures were made using NaOH molar concentration of 8M and 10M along with, Na₂SiO₃ to NaOH ratio of 0 and 1 by mass and 15% class F fly ash. Optimum alkali content and moisture content were determined for each RCGPC and RCC mixtures, respectively, using modified proctor test. Compressive strength, semi-circular bending beam strength, and dynamic modulus test were conducted to evaluate the mechanistic characteristics of both mixtures. To determine the optimum curing conditions for RCGPC, effects of different curing temperature and curing duration on compressive strength were also studied. Sulphate attack and freeze-thaw tests were also carried out to assess the durability properties of the developed mixtures. X-ray diffraction (XRD) was used for morphology and microstructure analysis. From the optimum moisture content results, it was found that RCGPC has high alkali content, which was mainly due to the high absorption capacity of RCA. It was found that the mixtures with Na₂SiO₃ to NaOH ratio of 1 yielded about 60% higher compressive strength than the ratio of 0. Further, the mixtures using 10M NaOH concentrations and alkali ratio of 1 produced about 28 MPa of compressive strength, which was around 33% higher than 8M NaOH mixtures. Similar results were obtained for elastic and dynamic modulus of the mixtures. On the other hand, the semi-circular bending beam strength remained the same for both 8 and 10 molar NaOH geopolymer mixtures. Formation of new geopolymeric compounds and chemical bonds in the newly formed novel RCGPC mixtures were also discovered using XRD analysis. The results of mechanical and durability testing further revealed that RCGPC performed similarly to that of RCC mixtures. Based on the results of mechanical and durability testing, the developed RCGPC mixtures using 100% recycled concrete could be used as a cost-effective solution for the construction of pavement structures.

Keywords: roller compacted concrete, geopolymer concrete, recycled concrete aggregate, concrete pavement, fly ash

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3263 Two-Way Reminder Systems to Support Activities of Daily Living for Adults with Cognitive Impairments: A Scoping Review

Authors: Julia Brudzinski, Ashley Croswell, Jade Mardin, Hannah Shilling, Jennifer Berg-Carnegie

Abstract:

Adults with brain injuries and mental illnesses commonly experience cognitive impairments that interfere with their participation in activities of daily living (ADLs). Prior research states that electronic reminder systems can support adults with cognitive impairments; however, previous studies focus primarily on one-way reminder systems. Research on adults with chronic diseases reported that two-way reminder systems yield better health outcomes and disease self-management compared to one-way reminder systems. Literature was identified through systematically searching 7 databases and hand-searching relevant reference lists. Retrieved studies were independently screened and reviewed by at least two members of the research team. Data was extracted on study design, participant characteristics, intervention details, study objectives, outcome measures, and important results. 574 articles were screened and reviewed. Nine articles met all inclusion criteria and were included. The literature focused on three main areas: system feasibility (n=8), stakeholder satisfaction (n=6), and efficacy of the two-way reminder systems (n=6). Participants in eight of the studies had brain injuries, with participants in only one study having a mental illness (i.e., schizophrenia). Two-way reminder systems were used to support participation in a wide range of ADLs. The current literature on two-way reminder systems to support ADLs for adults with cognitive impairments focuses on feasibility, stakeholder satisfaction, and system efficacy. Future research should focus on addressing the barriers to accessing and implementing two-way reminder systems and identifying specific client characteristics that would benefit most from using these systems.

Keywords: brain injury, digital health, occupational therapy, activities of daily living, two-way reminder systems

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3262 Efficacy of Corticosteroids versus Placebo in Third Molar Surgery: A Systematic Review of Patient-Reported Outcomes

Authors: Parastoo Parhizkar, Jaber Yaghini, Omid Fakheran

Abstract:

Background: Third molar surgery is often associated with postoperative problems which cause serious impediments on daily activities and quality of life. Steroidal anti-inflammatory drugs may decrease these common post-operative complications. The purpose of this review is evaluating the available evidence regarding the efficacy of corticosteroids used as adjunctive therapy for patients undergoing third molar surgery. Methods: PubMed, Google scholar, Scopus, web of science, clinicaltrials.gov, scirus.com, Cochrane central register for controlled trials, LILACS, OpenGrey, centerwatch, isrctn, who.int and ebsco were searched without restrictions regarding the year of publication. Randomized clinical trials assessing patient-reported outcomes in patients undergoing surgical therapy, were eligible for inclusion. Study quality was assessed using the CONSORT-checklist. No meta-analysis was performed. Results: A total of twelve Randomized Clinical Trials were included in this study. Methylprednisolone and Dexamethasone may decrease postoperative side effects such as pain, trismus and edema. Based on the results both of them could improve patients’ satisfaction, and there is no significant difference between these two types of corticosteroids regarding the patient centered outcomes (p > 0.05). Intralesional and intravenous injection of Dexamethasone showed an equivalent result, with statistically significant better results (P < 0.05) in comparison with the oral treatment. Conclusion: various types of corticosteroids can enhance the patient’s satisfaction following third molar surgery. However, there is no significant difference between Dexamethasone, Prednisolone and Methylprednisolone groups in this regard. Comparing the various administration routs, local injection of Dexamethasone is quite simple, painless and cost-effective adjunctive therapy with better drug efficacy.

Keywords: third molar surgery, corticosteroids, patient-reported outcomes, health related quality of life

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3261 Better Defined WHO International Classification of Disease Codes for Relapsing Fever Borreliosis, and Lyme Disease Education Aiding Diagnosis, Treatment Improving Human Right to Health

Authors: Mualla McManus, Jenna Luche Thaye

Abstract:

World Health Organisation International Classification of Disease codes were created to define disease including infections in order to guide and educate diagnosticians. Most infectious diseases such as syphilis are clearly defined by their ICD 10 codes and aid/help to educate the clinicians in syphilis diagnosis and treatment globally. However, current ICD 10 codes for relapsing fever Borreliosis and Lyme disease are less clearly defined and can impede appropriate diagnosis especially if the clinician is not familiar with the symptoms of these infectious diseases. This is despite substantial number of scientific articles published in peer-reviewed journals about relapsing fever and Lyme disease. In the USA there are estimated 380,000 people annually contacting Lyme disease, more cases than breast cancer and 6x HIV/AIDS cases. This represents estimated 0.09% of the USA population. If extrapolated to the global population (7billion), 0.09% equates to 63 million people contracting relapsing fever or Lyme disease. In many regions, the rate of contracting some form of infection from tick bite may be even higher. Without accurate and appropriate diagnostic codes, physicians are impeded in their ability to properly care for their patients, leaving those patients invisible and marginalized within the medical system and to those guiding public policy. This results in great personal hardship, pain, disability, and expense. This unnecessarily burdens health care systems, governments, families, and society as a whole. With accurate diagnostic codes in place, robust data can guide medical and public health research, health policy, track mortality and save health care dollars. Better defined ICD codes are the way forward in educating the diagnosticians about relapsing fever and Lyme diseases.

Keywords: WHO ICD codes, relapsing fever, Lyme diseases, World Health Organisation

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3260 Formulation Development, Process Optimization and Comparative study of Poorly Compressible Drugs Ibuprofen, Acetaminophen Using Direct Compression and Top Spray Granulation Technique

Authors: Abhishek Pandey

Abstract:

Ibuprofen and Acetaminophen is widely used as prescription & non-prescription medicine. Ibuprofen mainly used in the treatment of mild to moderate pain related to headache, migraine, postoperative condition and in the management of spondylitis, osteoarthritis and rheumatoid arthritis. Acetaminophen is used as an analgesic and antipyretic drug. Ibuprofen having high tendency of sticking to punches of tablet punching machine while Acetaminophen is not ordinarily compressible to tablet formulation because Acetaminophen crystals are very hard and brittle in nature and fracture very easily when compressed producing capping and laminating tablet defects therefore wet granulation method is used to make them compressible. The aim of study was to prepare Ibuprofen and Acetaminophen tablets by direct compression and top spray granulation technique. In this Investigation tablets were prepared by using directly compressible grade excipients. Dibasic calcium phosphate, lactose anhydrous (DCL21), microcrystalline cellulose (Avicel PH 101). In order to obtain best or optimized formulation, nine different formulations were generated among them batch F7, F8, F9 shows good results and within the acceptable limit. Formulation (F7) selected as optimize product on the basis of dissolution study. Furtherly, directly compressible granules of both drugs were prepared by using top spray granulation technique in fluidized bed processor equipment and compressed .In order to obtain best product process optimization was carried out by performing four trials in which various parameters like inlet air temperature, spray rate, peristaltic pump rpm, % LOD, properties of granules, blending time and hardness were optimized. Batch T3 coined as optimized batch on the basis physical & chemical evaluation. Finally formulations prepared by both techniques were compared.

Keywords: direct compression, top spray granulation, process optimization, blending time

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3259 Preparation and Characterization of Pectin Based Proton Exchange Membranes Derived by Solution Casting Method for Direct Methanol Fuel Cells

Authors: Mohanapriya Subramanian, V. Raj

Abstract:

Direct methanol fuel cells (DMFCs) are considered to be one of the most promising candidates for portable and stationary applications in the view of their advantages such as high energy density, easy manipulation, high efficiency and they operate with liquid fuel which could be used without requiring any fuel-processing units. Electrolyte membrane of DMFC plays a key role as a proton conductor as well as a separator between electrodes. Increasing concern over environmental protection, biopolymers gain tremendous interest owing to their eco-friendly bio-degradable nature. Pectin is a natural anionic polysaccharide which plays an essential part in regulating mechanical behavior of plant cell wall and it is extracted from outer cells of most of the plants. The aim of this study is to develop and demonstrate pectin based polymer composite membranes as methanol impermeable polymer electrolyte membranes for DMFCs. Pectin based nanocomposites membranes are prepared by solution-casting technique wherein pectin is blended with chitosan followed by the addition of optimal amount of sulphonic acid modified Titanium dioxide nanoparticle (S-TiO2). Nanocomposite membranes are characterized by Fourier Transform-Infra Red spectroscopy, Scanning electron microscopy, and Energy dispersive spectroscopy analyses. Proton conductivity and methanol permeability are determined into order to evaluate their suitability for DMFC application. Pectin-chitosan blends endow with a flexible polymeric network which is appropriate to disperse rigid S-TiO2 nanoparticles. Resulting nanocomposite membranes possess adequate thermo-mechanical stabilities as well as high charge-density per unit volume. Pectin-chitosan natural polymeric nanocomposite comprising optimal S-TiO2 exhibits good electrochemical selectivity and therefore desirable for DMFC application.

Keywords: biopolymers, fuel cells, nanocomposite, methanol crossover

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3258 Analysis of Barbell Kinematics of Snatch Technique among Women Weightlifters in India

Authors: Manish Kumar Pillai, Madhavi Pathak Pillai, Rajender Lal, Dinesh P. Sharma

Abstract:

India has not yet been able to produce many weightlifters in the past years. Karnam Malleshwari is the only woman to win a medal for India in Olympics. When we try to introspect, there seem to be different reasons. One of the probable cause could be the lack of biomechanical analysis for technique improvements. The analysis of motion in sports has gained prime importance for technical improvement. It helps an athlete to develop a better understanding of his own skills and increasing the rate of technical learning process. Kinematics is concerned with describing and quantifying both the linear and angular position of bodies and their time derivatives. The techniques analysis of barbell movement is very important in weightlifting. But women weightlifting has a shorter history than men’s. Research on women weightlifting based on video analysis is less; there is a lack of scientific evidence based on kinematic analysis of especially on Indian weightlifters at national level are limited. Hence, the present investigation was aimed to analyze the barbell kinematics of women weightlifters in India. The study was delimited to the medal winners of 69-kilogram weight category in the All India Inter-University Competition, age ranging between 18 and 28 years. The variables selected for the mechanical analysis of Barbell kinematics included barbell trajectory, velocity, acceleration, potential energy, kinetic energy, mechanical energy, and average power output. The performance was captured during the competition by two DV PC-60 Digital cameras (Panasonic Company, Ltd). Two cameras were placed 6-meters perpendicular to the plane of the motion, 130 cm. above the ground to record/capture the frontal and lateral view of the lifters simultaneously. Video recordings were analyzed by using Dartfish software, and barbell kinematics were analyzed with the information derived with the help of software. The result documented on the basis of the finding of the study clearly states that there are differences in the selected kinematic variables in all three lifters in respect to their technique in five phases during snatch technique using by them.

Keywords: dartfish, digital camera, kinematic, snatch, weightlifting

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3257 Effect of Mineral Additives on Improving the Geotechnical Properties of Soils in Chlef

Authors: Messaoudi Mohammed Amin

Abstract:

The reduction of available land resources and the increased cout associated with the use of hight quality materials have led to the need for local soils to be used in geotecgnical construction however, poor engineering properties of these soils pose difficulties for constructions project and need to be stabilized to improve their properties in oyher works unsuitable soils with low bearing capacity, high plasticity coupled with high insatbility are frequently encountered hense, there is a need to improve the physical and mechanical charateristics of these soils to make theme more suitable for construction this can be done by using different mechanical and chemical methods clayey soil stabilization has been practiced for quite sometime bu mixing additives, such us cement, lime and fly ash to the soil to increase its strength. The aim of this project is to study the effect of using lime, natural pozzolana or combination of both on the geotecgnical cherateristics of clayey soil. Test specimen were subjected to atterberg limits test, compaction test, box shear test and uncomfined compression test Lime or natural pozzolana was added to clayey soil at rangs of 0-8% and 0-20% respectively. In addition combinations of lime –natural pozzolana were added to clayey soil at the same ranges specimen were cured for 1-7, and 28 days after which they were tested for uncofined compression tests. Based on the experimental results, it was concluded that an important decrease of plasticity index was observed for thr samples stabilized with the combinition lime-natural pozzolana in addition, the use of the combination lime-natural pozzolana modifies the clayey soil classification according to casagrand plasiticity chart. Moreover, based on the favourable results of shear and compression strength obtained, it can be concluded that clayey soil can be successfuly stabilized by combined action of lime and natural pozzolana also this combination showed an appreciable improvement of the shear parameters. Finally, since natural pozzolana is much cheaper than lime ,the addition of natural pozzolana in lime soil mix may particulary become attractive and can result in cost reduction of construction.

Keywords: clay, soil stabilization, natural pozzolana, atterberg limits, compaction, compressive strength shear strength, curing

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3256 Comparison of Phynotypic Traits of Three Arabian Horse Strains

Authors: Saria Almarzook, Monika Reissmann, Gudrun Brockmann

Abstract:

Due to its history, occurrence in different ecosystems and diverse using, the modern horse (Equus caballus) shows large variability in size, appearance, behavior and habits. At all times, breeders try to create groups (breeds, strains) representing high homology but showing clear differences in comparison to other groups. A great interest of analyzing phenotypic and genetic traits looking for real diversity and genetic uniqueness existents for Arabian horses in Syria. 90 Arabian horses from governmental research center of Arabian horses in Damascus were included. The horses represent three strains (Kahlawi, Saklawi, Hamdani) originated from different geographical zones. They were raised on the same farm, under stable conditions. Twelve phenotypic traits were measured: wither height (WH), croup width (CW), croup height (CH), neck girth (NG), thorax girth (TG), chest girth (ChG), chest depth (ChD), chest width (ChW), back line length (BLL), body length (BL), fore cannon length (FCL) and hind cannon length (HCL). The horses were divided into groups according to age (less than 2 years, 2-4 years, 4-9 years, over 9 years) and to sex (male, female). The statistical analyzes show that age has significant influence of WH while the strain has only a very limited effect. On CW, NG, BLL, FCL and HCL, there is only a significant influence of sex. Age has significant effect on CH and BL. All sources of classes have a significant effect on TG, ChG, ChD and ChW. Strain has a significant effect on the BL. These results provide first information for real biodiversity in and between the strains and can be used to develop the breeding work in the Arabian horse breed.

Keywords: Arabian horse, phenotypic traits, strains, Syria

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3255 An Affordability Evaluation of Computer-Based Social-Emotional Skills Interventions for School-Aged Children with Autism Spectrum Disorder

Authors: Ezra N. S. Lockhart

Abstract:

The number of children diagnosed with autism spectrum disorder (ASD) has increased approximately 173% during the last decade making ASD the fastest growing developmental disability in the United States. This rise in prevalence rates indeed has an effect on schools. ASD is overwhelmingly the most reported primary special education eligibility category for students accessing special education, at a national average of 61.3%. ASD is regarded as an urgent public health concern at an estimated annual per capita cost of $3.2 million. Furthermore, considering that ASD is a lifelong disorder estimated lifetime per capita cost reach $35 billion. The resources available to special education programs are insufficient to meet the educational needs of the 6.4 million students receiving special educational services. This is especially true given that there has been and continues to be a chronic shortage of fully certified special education teachers for decades. Reports indicate that 81.1% of students with special needs spend 40% or more in general education classrooms. Regardless of whether support is implemented in the special education or general education classroom the resource demand is obvious. Schools are actively seeking to implement low-cost alternatives and budget saving measures in response to this demand. In public school settings, programs such as Applied Behavior Analysis are challenging to implement and fund at $40,000 per student per year. As an alternative, computer-based interventions are inexpensive, less time-consuming to implement, and require minimal teacher or paraprofessional training to administer. Affordability, pricing schemes, availability, and compatibility of computer-based interventions that support social and emotional skill development in individuals with ASD are discussed.

Keywords: affordability, autism spectrum disorder, computer-based intervention, emotional skills, social skills

Procedia PDF Downloads 152
3254 Collaborative Platform for Learning Basic Programming (Algorinfo)

Authors: Edgar Mauricio Ruiz Osuna, Claudia Yaneth Herrera Bolivar, Sandra Liliana Gomez Vasquez

Abstract:

The increasing needs of professionals with skills in software development in industry are incremental, therefore, the relevance of an educational process in line with the strengthening of these competencies, are part of the responsibilities of universities with careers related to the area of Informatics and Systems. In this sense, it is important to consider that in the National Science, Technology and Innovation Plan for the development of the Electronics, Information Technologies and Communications (2013) sectors, it is established as a weakness in the SWOT Analysis of the Software sector and Services, Deficiencies in training and professional training. Accordingly, UNIMINUTO's Computer Technology Program has addressed the analysis of students' performance in software development, identifying various problems such as dropout in programming subjects, academic averages, as well as deficiencies in strategies and competencies developed in the area of programming. As a result of this analysis, it was determined to design a collaborative learning platform in basic programming using heat maps as a tool to support didactic feedback. The pilot phase allows to evaluate in a programming course the ALGORINFO platform as a didactic resource, through an interactive and collaborative environment where students can develop basic programming practices and in turn, are fed back through the analysis of time patterns and difficulties frequent in certain segments or program cycles, by means of heat maps. The result allows the teacher to have tools to reinforce and advise critical points generated on the map, so that students and graduates improve their skills as software developers.

Keywords: collaborative platform, learning, feedback, programming, heat maps

Procedia PDF Downloads 149
3253 Static Relaxation of Glass Fiber Reinforced Pipes

Authors: Mohammed Y. Abdellah, Mohamed K. Hassan, A. F. Mohamed, Shadi M. Munshi, A. M. Hashem

Abstract:

Pips made from glass fiber reinforced polymer has competitive role in petroleum industry. The need of evaluating the mechanical behavior of (GRP) pipes is essential objects. Stress relaxation illustrates how polymers relieve stress under constant strain. Static relaxation test is carried out at room temperature. The material gives poor static relaxation strength, two loading cycles have been observed for the tested specimen.

Keywords: GRP, sandwich composite material, static relaxation, stress relief

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3252 Dry Binder Mixing of Field Trial Investigation Using Soil Mix Technology: Case Study on Contaminated Site Soil

Authors: Mary Allagoa, Abir Al-Tabbaa

Abstract:

The study explores the use of binders and additives, such as Portland cement, pulverized fuel ash, ground granulated blast furnace slag, and MgO, to decrease the concentration and leachability of pollutants in contaminated site soils. The research investigates their effectiveness and associated risks of using the binders, with a focus on Total Heavy metals (THM) and Total Petroleum Hydrocarbon (TPH). The goal of this research is to evaluate the performance and effectiveness of binders and additives in remediating soil pollutants. The study aims to assess the suitability of the mixtures for ground improvement purposes, determine the optimal dosage, and investigate the associated risks. The research utilizes physical (unconfined compressive strength) and chemical tests (batch leachability test) to assess the efficacy of the binders and additives. A completely randomized design one-way ANOVA is used to determine the significance within mix binders of THM. The study also employs incremental lifetime cancer risk assessments (ILCR) and other indexes to evaluate the associated risks. The study finds that Ground Granulated Blast Furnace Slag (GGBS): MgO is the most effective binder for remediation, particularly when using low dosages of MgO combined with higher dosages of GGBS binders on TPH. The results indicate that binders and additives can encapsulate and immobilize pollutants, thereby reducing their leachability and toxicity. The mean unconfined compressive strength of the soil ranges from 285.0- 320.5 kPa, while THM levels are less than 10 µg/l in GGBS: MgO and CEM: PFA but below 1 µg/l in CEM I based. The ILCR ranged from 6.77E-02 - 2.65E-01 and 5.444E-01 – 3.20 E+00, with the highest values observed under extreme conditions. The hazard index (HI), Risk allowable daily dose intake (ADI), and Risk chronic daily intake (CDI) were all less than 1 for the THM. The study identifies MgO as the best additive for use in soil remediation.

Keywords: risk ADI, risk CDI, ILCR, novel binders, additives binders, hazard index

Procedia PDF Downloads 773
3251 The Effects of Prolonged Use of Caffeine on Thyroid and Adrenal Glands – A Retrospective Cohort Study

Authors: Vasishtha Avadhani Upadrasta, Mradul Kumar Daga, Smita Kaushik

Abstract:

Background: Caffeine consumption has skyrocketed in the recent decades as we try to match pace with the machines. Studies have been conducted on animals and a few on humans, mainly on the acute effects of high-dose caffeine intake. Almost none have been conducted on the chronic effects of caffeine consumption. This study involved Medical professionals as case subjects, who consumed caffeine daily. Methods: This study, over a period of 3 months, involved 96 volunteers (chosen randomly w.r.t. gender and field in medical fraternity), including people who drank >500mg of caffeine a day to people who consumed none. People with any co-morbidities at all were excluded straight away. Two sets of blood samples were drawn and assessed. Three groups were created, Group 1 (>200mg caffeine/day) and Group 2 (15-200 mg caffeine/day) and Group 3 (<200mg Caffeine/day). Results: The result of the study found that exposure to caffeine at doses >200mg/day for more than 6 months leads to a significant difference in circulating free T3 [(-0.96 pmol/L ± 0.07) = (-18.5%), CI 95%, p = .000024] and Cortisol [(-123 nmol/L ± 9.8) = (-46.8%), CI 95%, p = .00029] hormones but shows an insignificant effect on circulating TSH [0.4 mIU/L, CI 95%, p=.37] and ACTH [(-3.2 pg/ml ± 0.3), CI 95%, p = .53) hormones, which stay within normal physiological ranges, irrespective of the daily dose of consumption. Results also highlight that women are more susceptible to decrement in fT3 than men (Relative Risk =1.58, ANOVA F-static = 7.15, p = 0.0105). Conclusions: Caffeine consumption in excess of 200mg/day, for more than or equal to 6 months, causes significant derangement in basal fT3 and Cortisol hormone levels, without affecting the TSH and ACTH (regulatory) hormone levels, indicating disturbance of action at the peripheral and/or cellular levels, possibly via the Paraventricular Nucleus –Leptin-CAR-Adenosine interactions. Women are more susceptible to decrement in fT3 levels than men (at same dose of caffeine).

Keywords: ACTH, adrenals, caffeine, cortisol, thyroid, thyroxin, TSH

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3250 Welding Technology Developments for Stringer-Skin Joints with Al-Li Alloys

Authors: Egoitz Aldanondo, Ekaitz Arruti, Amaia Iturrioz, Ivan Huarte, Fidel Zubiri

Abstract:

Manufacturing aeronautic structures joining extruded profiles or stringers to sheets or skins of aluminium is a typical manufacturing procedure in aeronautic structures. Although riveting is the conventional manufacturing technology to produce such joints, the Friction Stir Welding (FSW) and Laser Beam Welding (LBW) technologies have also demonstrated their potential for this kind of applications. Therefore, FSW and LBW technologies have the potential to continue their development as manufacturing processes for aeronautic structures showing benefits such as time-saving, light-weighting and overall cost reduction. In addition to that, new aluminium-lithium based alloy developments represent great opportunities for advanced aeronautic structure manufacturing with potential benefits such as lightweight construction or improved corrosion resistance. This work presents the main approaches by FSW and LBW to develop those technologies to produce stiffened panel structures such as fuselage by stringer-skin joints and using innovative aluminium-lithium alloys. Initial welding tests were performed in AA2198-T3S aluminium alloys for LBW technology and with AA2198-T851 for FSW. Later tests for both FSW and LBW have been carried out using AA2099-T83 alloy extrusions as stringers and AA2060-T8E30 as skin materials. The weld quality and properties have been examined by metallographic analysis and mechanical testing, including shear tensile tests and pull-out tests. The analysis of the results have shown the relationships between processing conditions, micro-macrostructural properties and the mechanical strength of the welded joints. The effects produced in the different alloys investigated have been observed and particular weld formation mechanics have been studied for each material and welding technology. Therefore, relationships between welding conditions and the obtained weld properties for each material combination and welding technology will be discussed in this presentation.

Keywords: AA2060-T8E30, AA2099-T83, AA2198-T3S, AA2198-T851, friction stir welding, laser beam welding

Procedia PDF Downloads 188
3249 Effect of Dissolved Oxygen Concentration on Iron Dissolution by Liquid Sodium

Authors: Sami Meddeb, M. L Giorgi, J. L. Courouau

Abstract:

This work presents the progress of studies aiming to guarantee the lifetime of 316L(N) steel in a sodium-cooled fast reactor by determining the elementary corrosion mechanism, which is akin to an accelerated dissolution by dissolved oxygen. The mechanism involving iron, the main element of steel, is particularly studied in detail, from the viewpoint of the data available in the literature, the modeling of the various mechanisms hypothesized. Experiments performed in the CORRONa facility at controlled temperature and dissolved oxygen content are used to test both literature data and hypotheses. Current tests, performed at various temperatures and oxygen content, focus on specifying the chemical reaction at play, determining its free enthalpy, as well as kinetics rate constants. Specific test configuration allows measuring the reaction kinetics and the chemical equilibrium state in the same test. In the current state of progress of these tests, the dissolution of iron accelerated by dissolved oxygen appears as directly related to a chemical complexation reaction of mixed iron-sodium oxide (Na-Fe-O), a compound that is soluble in the liquid sodium solution. Results obtained demonstrate the presence in the solution of this corrosion product, whose kinetics is the limiting step under the conditions of the test. This compound, the object of hypotheses dating back more than 50 years, is predominant in solution compared to atomic iron, presumably even for the low oxygen concentration, and cannot be neglected for the long-term corrosion modeling of any heat transfer system.

Keywords: corrosion, sodium fast reactors, iron, oxygen

Procedia PDF Downloads 174
3248 Effects of Temperature and Mechanical Abrasion on Microplastics

Authors: N. Singh, G. K. Darbha

Abstract:

Since the last decade, a wave of research has begun to study the prevalence and impact of ever-increasing plastic pollution in the environment. The wide application and ubiquitous distribution of plastic have become a global concern due to its persistent nature. The disposal of plastics has emerged as one of the major challenges for waste management landfills. Microplastics (MPs) have found its existence in almost every environment, from the high altitude mountain lake to the deep sea sediments, polar icebergs, coral reefs, estuaries, beaches, and river, etc. Microplastics are fragments of plastics with size less than 5 mm. Microplastics can be classified as primary microplastics and secondary microplastics. Primary microplastics includes purposefully introduced microplastics into the end products for consumers (microbeads used in facial cleansers, personal care product, etc.), pellets (used in manufacturing industries) or fibres (from textile industries) which finally enters into the environment. Secondary microplastics are formed by disintegration of larger fragments under the exposure of sunlight, mechanical abrasive forces by rain, waves, wind and/or water. A number of factors affect the quantity of microplastic present in freshwater environments. In addition to physical forces, human population density proximal to the water body, proximity to urban centres, water residence time, and size of the water body also affects plastic properties. With time, other complex processes in nature such as physical, chemical and biological break down plastics by interfering with its structural integrity. Several studies demonstrate that microplastics found in wastewater sludge being used as manure for agricultural fields, thus having the tendency to alter the soil environment condition influencing the microbial population as well. Inadequate data are available on the fate and transport of microplastics under varying environmental conditions that are required to supplement important information for further research. In addition, microplastics have the tendency to absorb heavy metals and hydrophobic organic contaminants such as PAHs and PCBs from its surroundings and thus acting as carriers for these contaminants in the environment system. In this study, three kinds of microplastics (polyethylene, polypropylene and expanded polystyrene) of different densities were chosen. Plastic samples were placed in sand with different aqueous media (distilled water, surface water, groundwater and marine water). It was incubated at varying temperatures (25, 35 and 40 °C) and agitation levels (rpm). The results show that the number of plastic fragments enhanced with increase in temperature and agitation speed. Moreover, the rate of disintegration of expanded polystyrene is high compared to other plastics. These results demonstrate that temperature, salinity, and mechanical abrasion plays a major role in degradation of plastics. Since weathered microplastics are more harmful as compared to the virgin microplastics, long-term studies involving other environmental factors are needed to have a better understanding of degradation of plastics.

Keywords: environmental contamination, fragmentation, microplastics, temperature, weathering

Procedia PDF Downloads 152
3247 Mechanical Behavior of 16NC6 Steel Hardened by Burnishing

Authors: Litim Tarek, Taamallah Ouahiba

Abstract:

This work relates to the physico-geometrical aspect of the surface layers of 16NC6 steel having undergone the burnishing treatment by hard steel ball. The results show that the optimal effects of burnishing are closely linked to the shape and the material of the active part of the device as well as to the surface plastic deformation ability of the material to be treated. Thus the roughness is improved by more than 70%, and the consolidation rate is increased by 30%. In addition, modeling of the rational traction curves provides a work hardening coefficient of up to 0.3 in the presence of burnishing.

Keywords: 16NC6 steel, burnishing, hardening, roughness

Procedia PDF Downloads 151
3246 Comparison of Deep Brain Stimulation Targets in Parkinson's Disease: A Systematic Review

Authors: Hushyar Azari

Abstract:

Aim and background: Deep brain stimulation (DBS) is regarded as an important therapeutic choice for Parkinson's disease (PD). The two most common targets for DBS are the subthalamic nucleus (STN) and globus pallidus (GPi). This review was conducted to compare the clinical effectiveness of these two targets. Methods: A systematic literature search in electronic databases: Embase, Cochrane Library and PubMed were restricted to English language publications 2010 to 2021. Specified MeSH terms were searched in all databases. Studies which evaluated the Unified Parkinson's Disease Rating Scale (UPDRS) III were selected by meeting the following criteria: (1) compared both GPi and STN DBS; (2) had at least three months follow-up period; (3)at least five participants in each group; (4)conducted after 2010. Study quality assessment was performed using the Modified Jadad Scale. Results: 3577 potentially relevant articles were identified, of these, 3569 were excluded based on title and abstract, duplicate and unsuitable article removal. Eight articles satisfied the inclusion criteria and were scrutinized (458 PD patients). According to Modified Jadad Scale, the majority of included studies had low evidence quality which was a limitation of this review. 5 studies reported no statistically significant between-group difference for improvements in UPDRS ш scores. At the same time, there were some results in terms of pain, action tremor, rigidity, and urinary symptoms, which indicated that STN DBS might be a better choice. Regarding the adverse effects, GPi was superior. Conclusion: It is clear that other larger randomized clinical trials with longer follow-up periods and control groups are needed to decide which target is more efficient for deep brain stimulation in Parkinson’s disease and imposes fewer adverse effects on the patients. Meanwhile, STN seems more reasonable according to the results of this systematic review.

Keywords: brain stimulation, globus pallidus, Parkinson's disease, subthalamic nucleus

Procedia PDF Downloads 174
3245 Mathematical Modeling of Avascular Tumor Growth and Invasion

Authors: Meitham Amereh, Mohsen Akbari, Ben Nadler

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Cancer has been recognized as one of the most challenging problems in biology and medicine. Aggressive tumors are a lethal type of cancers characterized by high genomic instability, rapid progression, invasiveness, and therapeutic resistance. Their behavior involves complicated molecular biology and consequential dynamics. Although tremendous effort has been devoted to developing therapeutic approaches, there is still a huge need for new insights into the dark aspects of tumors. As one of the key requirements in better understanding the complex behavior of tumors, mathematical modeling and continuum physics, in particular, play a pivotal role. Mathematical modeling can provide a quantitative prediction on biological processes and help interpret complicated physiological interactions in tumors microenvironment. The pathophysiology of aggressive tumors is strongly affected by the extracellular cues such as stresses produced by mechanical forces between the tumor and the host tissue. During the tumor progression, the growing mass displaces the surrounding extracellular matrix (ECM), and due to the level of tissue stiffness, stress accumulates inside the tumor. The produced stress can influence the tumor by breaking adherent junctions. During this process, the tumor stops the rapid proliferation and begins to remodel its shape to preserve the homeostatic equilibrium state. To reach this, the tumor, in turn, upregulates epithelial to mesenchymal transit-inducing transcription factors (EMT-TFs). These EMT-TFs are involved in various signaling cascades, which are often associated with tumor invasiveness and malignancy. In this work, we modeled the tumor as a growing hyperplastic mass and investigated the effects of mechanical stress from surrounding ECM on tumor invasion. The invasion is modeled as volume-preserving inelastic evolution. In this framework, principal balance laws are considered for tumor mass, linear momentum, and diffusion of nutrients. Also, mechanical interactions between the tumor and ECM is modeled using Ciarlet constitutive strain energy function, and dissipation inequality is utilized to model the volumetric growth rate. System parameters, such as rate of nutrient uptake and cell proliferation, are obtained experimentally. To validate the model, human Glioblastoma multiforme (hGBM) tumor spheroids were incorporated inside Matrigel/Alginate composite hydrogel and was injected into a microfluidic chip to mimic the tumor’s natural microenvironment. The invasion structure was analyzed by imaging the spheroid over time. Also, the expression of transcriptional factors involved in invasion was measured by immune-staining the tumor. The volumetric growth, stress distribution, and inelastic evolution of tumors were predicted by the model. Results showed that the level of invasion is in direct correlation with the level of predicted stress within the tumor. Moreover, the invasion length measured by fluorescent imaging was shown to be related to the inelastic evolution of tumors obtained by the model.

Keywords: cancer, invasion, mathematical modeling, microfluidic chip, tumor spheroids

Procedia PDF Downloads 102
3244 Planning Politics of Dhaka City: Recent Urbanization and Gentrification

Authors: N. M. Esa Abrar Khan

Abstract:

This paper will describe how a city planning can be abusive and promote gentrification in Dhaka city area in an extreme remorseless way. To our knowledge, Dhaka is enormously overpopulated, and its somewhat unrest political situation and corruption is promoting not only bruised urban growth but also this growth leering people socially and mentally. Due to globalization, whole world is in a rat race of development fiesta and Bangladesh is no longer falling back in this race. Recent political agenda is to develop the country anyhow, whether it is a good development or not. In the name of development, Dhaka city is becoming overwhelmed with flyovers, needless shopping malls and commercial complexes. This drastic urbanization is promoting gentrification. Gentrification is the process of societal change which intimidate the existing group of people from a certain place and encouraging affluent group of people on that place and eventually they take the control of that place. Process of gentrification is more capitalistic rather socially democratic. Architects are indirectly or directly related with this social change and politics is the catalyst of these social alteration. The methodology of this paper was mainly dependent on mass interviews including political leaders and activist’s interviews. Also, photographic analysis, empirical research etc. helped to create this paper. Secondary data were collected from different published and unpublished documents, relevant research articles, and books. From the study, it is clearly can be said that architects and urban designers are promoting social imbalance. The paper tried to suggest how architects and other designers can help to resist gentrification and can remain the social heterogeneity.

Keywords: gentrification, migration, Bangladesh, urban, globalization, hybrid

Procedia PDF Downloads 163