Search results for: renal tubular acidosis
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 426

Search results for: renal tubular acidosis

156 Roll Forming Process and Die Design for a Large Size Square Tube

Authors: Jinn-Jong Sheu, Cang-Fu Liang, Cheng-Hsien Yu

Abstract:

This paper proposed the cold roll forming process and the die design methods for a 400mm by 400 mm square tube with 16 mm in thickness. The tubular blank made by cold roll forming is 508mm in diameter. The square tube roll forming process was designed considering the layout of rolls and the compression ratio distribution for each stand. The final tube corner radius and the edge straightness in the front end of the tube are to be controlled according to the tube specification. A five-stand forming design using four rolls at each stand was proposed to establish the base reference of square tube roll forming quality. Different numbers of pass and roll designs were proposed and compared to the base design in order to find the feasibility of increase pass number to improve the square tube quality. The proposed roll forming processes were simulated using FEM analysis. The thickness variations of the corner and the edge areas were examined. The maximum loads and the torques of each stand were calculated to study the power consumption of the roll forming machine. The simulation results showed the square tube thickness variations and concavity of the edge are acceptable with the JIS tube specifications for the base design. But the maximum loads and torques are very high. By changing the layout and the number of the rolls were able to obtain better tube geometry and decrease the maximum load and torque of each stand. This paper had shown the feasibility of designing the roll forming process and the layout of dies using FEM simulation. The obtained information is helpful to the roll forming machine design for a large size square tube making.

Keywords: cold roll forming, FEM analysis, roll forming die design, tube roll forming

Procedia PDF Downloads 271
155 Performance Analysis of a Shell and Tube Heat Exchanger in the Organic Rankine Cycle Power Plant

Authors: Yogi Sirodz Gaos, Irvan Wiradinata

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In the 500 kW Organic Rankine Cycle (ORC) power plant in Indonesia, an AFT (according to the Tubular Exchanger Manufacturers Association – TEMA) type shell and tube heat exchanger device is used as a pre-heating system for the ORC’s hot water circulation system. The pre-heating source is a waste heat recovery of the brine water, which is tapped from a geothermal power plant. The brine water itself has 5 MWₜₕ capacities, with average temperature of 170ᵒC, and 7 barg working pressure. The aim of this research is to examine the performance of the heat exchanger in the ORC system in a 500 kW ORC power plant. The data for this research were collected during the commissioning on the middle of December 2016. During the commissioning, the inlet temperature and working pressure of the brine water to the shell and tube type heat exchanger was 149ᵒC, and 4.4 barg respectively. Furthermore, the ΔT for the hot water circulation of the ORC system to the heat exchanger was 27ᵒC, with the inlet temperature of 140ᵒC. The pressure in the hot circulation system was dropped slightly from 7.4ᵒC to 7.1ᵒC. The flow rate of the hot water circulation was 80.5 m³/h. The presentation and discussion of a case study on the performance of the heat exchanger on the 500 kW ORC system is presented as follows: (1) the heat exchange duty is 2,572 kW; (2) log mean temperature of the heat exchanger is 13.2ᵒC; (3) the actual overall thermal conductivity is 1,020.6 W/m².K (4) the required overall thermal conductivity is 316.76 W/m².K; and (5) the over design for this heat exchange performance is 222.2%. An analysis of the heat exchanger detailed engineering design (DED) is briefly discussed. To sum up, this research concludes that the shell and tube heat exchangers technology demonstrated a good performance as pre-heating system for the ORC’s hot water circulation system. Further research need to be conducted to examine the performance of heat exchanger system on the ORC’s hot water circulation system.

Keywords: shell and tube, heat exchanger, organic Rankine cycle, performance, commissioning

Procedia PDF Downloads 120
154 Structural Evolution of Electrodeposited Ni Coating on Ti-6Al-4V Alloy during Heat Treatment

Authors: M. Abdoos, A. Amadeh, M. Adabi

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In recent decades, the use of titanium and its alloys due to their high mechanical properties, light weight and their corrosion resistance has increased in military and industry applications. However, the poor surface properties can limit their widely usage. Many researches were carried out to improve their surface properties. The most effective technique is based on solid-state diffusion of elements that can form intermetallic compounds with the substrate. In the present work, inter-diffusion of nickel and titanium and formation of Ni-Ti intermetallic compounds in nickel-coated Ti-6Al-4V alloy have been studied. Initially, nickel was electrodeposited on the alloy using Watts bath at a current density of 20 mA/cm2 for 1 hour. The coated specimens were then heat treated in a tubular furnace under argon atmosphere at different temperatures near Ti β-transus to maximize the diffusion rate for various durations in order to improve the surface properties of the Ti-6Al-4V alloy. The effect of temperature and time on the thickness of diffusion layer and characteristics of intermetallic phases was studied by means of scanning electron microscope (SEM) equipped with energy dispersive X-ray spectrometer (EDS) and microhardness test. The results showed that a multilayer structure was formed after heat treatment: an outer layer of remaining nickel, an area of intermetallic layers with different compositions and solid solution of Ni-Ti. Three intermetallic layers was detected by EDS analysis, namely an outer layer with about 75 at.% Ni (Ni3Ti), an intermediate layer with 50 at.% Ni (NiTi) and finally an inner layer with 36 at.% Ni (NiTi2). It was also observed that the increase in time or temperature led to the formation of thicker intermetallic layers. Meanwhile, the microhardness of heat treated samples increased with formation of Ni-Ti intermetallics; however, its value depended on heat treatment parameters.

Keywords: heat treatment, microhardness, Ni coating, Ti-6Al-4V

Procedia PDF Downloads 417
153 Mechanism of Action of Troxerutin in Reducing Oxidative Stress

Authors: Nasrin Hosseinzad

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Troxerutin, a trihydroxyethylated derived of rutin, is a flavonoid existing in tea, coffee, cereal grains, various fruits and vegetables have been conveyed to display radioprotective, antithrombotic, nephron-protective and hepato-protective possessions. Troxerutin, has been well-proved to utilize hepatoprotective assets. Troxerutin could upturn the resistance of hippocampal neurons alongside apoptosis by lessening the action of AChE and oxidative stress. Consequently, troxerutin may have advantageous properties in the administration of Alzheimer's disease and cancer. Troxerutin has been testified to have several welfares and medicinal stuffs. It could shelter the mouse kidney against d-gal-induced damage by refining renal utility, decreasing histopathologic changes, dropping ROS construction, reintroducing the activities of antioxidant enzymes and reducing DNA oxidative destruction. The DNA cleavage study clarifies that troxerutin showed DNA protection against hydroxyl radical persuaded DNA mutilation. Troxerutin uses anti-cancer effect in HuH-7 hepatocarcinoma cells conceivably through synchronized regulation of the molecular signalling pathways, Nrf2 and NF-κB. DNA binding at slight channel by troxerutin may have donated to feature breaks leading to improved radiation brought cell death. Furthermore, the mechanism principal the observed variance in the antioxidant activities of troxerutin and its esters was qualified to equally their free radical scavenging capabilities and dissemination on the cell membrane outward.

Keywords: troxerutin, DNA, oxidative stress, antioxidant, free radical

Procedia PDF Downloads 130
152 Interaction of GCN5L1 with WHAMM and KIF5B Regulates Autolysosome Tubulation

Authors: Allen Seylani

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Lysosome-dependent autophagy is a nutrient-deprivation-induced evolutionarily conserved intracellular recycling program that sequestrates intracellular cargo into autophagosomes (AP), which then fuse with lysosomes to form autolysosomes (ALs) for cargo digestion. To restore free lysosomes, autophagic lysosome reformation (ALR) is initiated by extrusion of tubular structures from autolysosomes at the final stage of autophagy, in a process called lysosomal tubulation (LT). This project aimed to investigate the molecular mechanism of GCN5L1 in LT and the following lysosomal signaling. GCN5L1 belongs to the BORC multiprotein complexes and is involved in controlling lysosomal trafficking; however, the effect of GCN5L1 on lysosome tubulation remains largely unknown. Genetic ablation of GCN5L1 in the mouse primary hepatocytes showed dramatically increased autolysosomes (ALs), decreased lysosome regeneration and absence of lysosomal tubulation. This phenotype suggests the possibility of disruption in lysosome tubulation, which results in the disturbance of the overall lysosome homeostasis. The formation of tubulars from ALs requires kinesin motor protein KIF5B. Immunoprecipitation was employed and confirmed the interaction of GCN5L1 with the ARL8B-KIF5B complex, which recruited KIF5B to ALs. At the same time, GCN5L1 interacted with WHAMM, which promotes the actin nucleation factor, which brings actin cytoskeleton to ALs and initiates LT. Furthermore, impaired LT in GCN5L1 deficient hepatocytes was restored by overexpression of GCN5L1, and this rescue effect was attenuated by knockdown of KIF5B. Additionally, lysosomal mTORC1 activity was upregulated in GCN5L1-/- hepatocytes, while inhibition of mTORC1 abrogated the GCN5L1 mediated rescue of LT in knockout hepatocytes. Altogether these findings revealed a novel mechanism of ALR, in which a simultaneous interaction of GCN5L1 with KIF5B and WHAMM is required for LT and downstream mTORC1 signaling.

Keywords: autophagy, autolysosome, GCN5L1, lysosome

Procedia PDF Downloads 127
151 Comparative Study of Free Vibrational Analysis and Modes Shapes of FSAE Car Frame Using Different FEM Modules

Authors: Rajat Jain, Himanshu Pandey, Somesh Mehta, Pravin P. Patil

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Formula SAE cars are the student designed and fabricated formula prototype cars, designed according to SAE INTERNATIONAL design rules which compete in the various national and international events. This paper shows a FEM based comparative study of free vibration analysis of different mode shapes of a formula prototype car chassis frame. Tubing sections of different diameters as per the design rules are designed in such a manner that the desired strength can be achieved. Natural frequency of first five mode was determined using finite element analysis method. SOLIDWORKS is used for designing the frame structure and SOLIDWORKS SIMULATION and ANSYS WORKBENCH 16.2 are used for the modal analysis. Mode shape results of ANSYS and SOLIDWORKS were compared. Fixed –fixed boundary conditions are used for fixing the A-arm wishbones. The simulation results were compared for the validation of the study. First five modes were compared and results were found within the permissible limits. The AISI4130 (CROMOLY- chromium molybdenum steel) material is used and the chassis frame is discretized with fine quality QUAD mesh followed by Fixed-fixed boundary conditions. The natural frequency of the chassis frame is 53.92-125.5 Hz as per the results of ANSYS which is found within the permissible limits. The study is concluded with the light weight and compact chassis frame without compensation with strength. This design allows to fabricate an extremely safe driver ergonomics, compact, dynamically stable, simple and light weight tubular chassis frame with higher strength.

Keywords: FEM, modal analysis, formula SAE cars, chassis frame, Ansys

Procedia PDF Downloads 309
150 Comparative Study for Neonatal Outcome and Umbilical Cord Blood Gas Parameters in Balanced and Inhalant Anesthesia for Elective Cesarean Section in Dogs

Authors: Agnieszka Antończyk, MałGorzata Ochota, Wojciech Niżański, ZdzisłAw Kiełbowicz

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The goal of the cesarean section (CS) is the delivery of healthy, vigorous pups with the provision of surgical plane anesthesia, appropriate analgesia, and rapid recovery of the dam. In human medicine, spinal or epidural anesthesia is preferred for a cesarean section as associated with a lower risk of neonatal asphyxia and the need for resuscitation. Nevertheless, the specificity of veterinary patients makes the application of regional anesthesia as a sole technique impractical, thus to obtain patient compliance the general anesthesia is required. This study aimed to compare the influence of balanced (inhalant with epidural) and inhalant anesthesia on neonatal umbilical cord blood gas (UCBG) parameters and vitality (modified Apgar scoring). The bitches (31) undergoing elective CS were enrolled in this study. All females received a single dose of 0.2 mg/kg s.c. Meloxicam. Females were randomly assigned into two groups: Gr I (Isoflurane, n=16) and Gr IE (Isoflurane plus Epidural, n=15). Anesthesia was induced with propofol at 4-6 mg/kg to effect, and maintained with isoflurane in oxygen; in IE group epidural anesthesia was also done using lidocaine (3-4 mg/kg) into the lumbosacral space. CSs were performed using a standard mid-line approach. Directly after the puppy extraction, the umbilical cord was double clamped before the placenta detachment. The vessels were gently stretched between forceps to allow blood sampling. At least 100 mcl of mixed umbilical cord blood was collected into a heparinized syringe for further analysis. The modified Apgar scoring system (AS) was used to objectively score neonatal health and vitality immediately after birth (before first aid or neonatal care was instituted), at 5 and 20 min after birth. The neonates were scored as normal (AS 7-10), weak (AS 4-6), or critical (AS 0-3). During surgery, the IE group required a lower isoflurane concentration compared to the females in group I (MAC 1.05±0.2 and 1.4±0.13, respectively, p<0.01). All investigated UCBG parameters were not statistically different between groups. All pups had mild acidosis (pH 7.21±0.08 and 7.21±0.09 in Gr I and IE, respectively) with moderately elevated pCO2 (Gr I 57.18±11.48, Gr IE 58.74±15.07), HCO3- on the lower border (Gr I 22.58±3.24, Gr IE 22.83±3.6), lowered BE (Gr I -6.1±3.57, Gr IE -5.6±4.19) and mildly elevated level of lactates (Gr I 2.58±1.48, Gr IE2.53±1.03). The glucose levels were above the reference limits in both groups of puppies (74.50±25.32 in Gr I, 79.50±29.73 in Gr IE). The initial Apgar score results were similar in I and IE groups. However, the subsequent measurements of AS revealed significant differences between both groups. Puppies from the IE group received better AS scores at 5 and 20 min compared to the I group (6.86±2.23 and 8.06±2.06 vs 5.11±2.40 and 7.83±2.05, respectively). The obtained results demonstrated that administration of epidural anesthesia reduced the requirement for isoflurane in dams undergoing cesarean section and did not affect the neonatal umbilical blood gas results. Moreover, newborns from the epidural anesthesia group were scored significantly higher in AS at 5 and 20 min, indicating their better vitality and quicker improvement post-surgery.

Keywords: apgar scoring, balanced anesthesia, cesarean section, umbilical blood gas

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149 Advancing Dialysis Care Access And Health Information Management: A Blueprint For Nairobi Hospital

Authors: Kimberly Winnie Achieng Otieno

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The Nairobi Hospital plays a pivotal role in healthcare provision in East and Central Africa, yet it faces challenges in providing accessible dialysis care. This paper explores strategic interventions to enhance dialysis care, improve access and streamline health information management, with an aim of fostering an integrated and patient-centered healthcare system in our region. Challenges at The Nairobi Hospital The Nairobi Hospital currently grapples with insufficient dialysis machines which results in extended turn around times. This issue stems from both staffing bottle necks and infrastructural limitations given our growing demand for renal care services. Our Paper-based record keeping system and fragmented flow of information downstream hinders the hospital’s ability to manage health data effectively. There is also a need for investment in expanding The Nairobi Hospital dialysis facilities to far reaching communities. Setting up satellite clinics that are closer to people who live in areas far from the main hospital will ensure better access to underserved areas. Community Outreach and Education Implementing education programs on kidney health within local communities is vital for early detection and prevention. Collaborating with local leaders and organizations can establish a proactive approach to renal health hence reducing the demand for acute dialysis interventions. We can amplify this effort by expanding The Nairobi Hospital’s corporate social responsibility outreach program with weekend engagement activities such as walks, awareness classes and fund drives. Enhancing Efficiency in Dialysis Care Demand for dialysis services continues to rise due to an aging Kenyan population and the increasing prevalence of chronic kidney disease (CKD). Present at this years International Nursing Conference are a diverse group of caregivers from around the world who can share with us their process optimization strategies, patient engagement techniques and resource utilization efficiencies to catapult The Nairobi Hospital to the 21st century and beyond. Plans are underway to offer ongoing education opportunities to keep staff updated on best practices and emerging technologies in addition to utilizing a patient feedback mechanisms to identify areas for improvement and enhance satisfaction. Staff empowerment and suggestion boxes address The Nairobi Hospital’s organizational challenges. Current financial constraints may limit a leapfrog in technology integration such as the acquisition of new dialysis machines and an investment in predictive analytics to forecast patient needs and optimize resource allocation. Streamlining Health Information Management Fully embracing a shift to 100% Electronic Health Records (EHRs) is a transformative step toward efficient health information management. Shared information promotes a holistic understanding of patients’ medical history, minimizing redundancies and enhancing overall care quality. To manage the transition to community-based care and EHRs effectively, a phased implementation approach is recommended. Conclusion By strategically enhancing dialysis care access and streamlining health information management, The Nairobi Hospital can strengthen its position as a leading healthcare institution in both East and Central Africa. This comprehensive approach aligns with the hospital’s commitment to providing high-quality, accessible, and patient-centered care in an evolving landscape of healthcare delivery.

Keywords: Africa, urology, diaylsis, healthcare

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148 Antihypertensive Activity of Alcoholic Extract of Citrus Paradise Juice in One Clip One Kidney Hypertension Model in Rats

Authors: Lokesh Bhatt, Jayesh Rathod

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Hypertension is one of the most prevalent cardiovascular disorder. It is responsible for several other cardiovascular disorders. Although many drugs are available for the treatment of hypertension, still a large population has uncontrolled blood pressure. Thus there is an unmet need for new therapeutic approaches for the same. Fruit juice of Citrus paradise contains several flavonoids with vasodilatory activity. We hypothesized that alcoholic extract of Citrus paradise, which contains flavonoids, might attenuate hypertension. The objective of the present study was to evaluate the antihypertensive activity of alcoholic extract of Citrus paradise fruit juice in rats. Hypertension was induced using one clip one kidney model in rats. The renal artery was occluded for 4 h after removal of one kidney. Once stabilized, the ganglionic blockade was performed followed by removal of the arterial clip from the kidney. Removal of clip resulted in an increase in blood pressure which is due to release of renin from the kidney. Alcoholic extract of Citrus paradise fruit juice was then administered at 50 mg/kg and 100 mg/kg dose by intravenous injection. Blood pressure was monitored continuously. Alcoholic extract of Citrus paradise fruit juice reduced hypertension in dose-dependent manner. Antihypertensive activity was found to be associated with vasodilation. The results of the present study showed antihypertensive potential of alcoholic extract of Citrus paradise fruit juice.

Keywords: citrus paradise, alcoholic extract, one clip one kidney model, vasodilation

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147 Experimental Study of Hydrogen and Water Vapor Extraction from Helium with Zeolite Membranes for Tritium Processes

Authors: Rodrigo Antunes, Olga Borisevich, David Demange

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The Tritium Laboratory Karlsruhe (TLK) has identified zeolite membranes as most promising for tritium processes in the future fusion reactors. Tritium diluted in purge gases or gaseous effluents, and present in both molecular and oxidized forms, can be pre-concentrated by a stage of zeolite membranes followed by a main downstream recovery stage (e.g., catalytic membrane reactor). Since 2011 several membrane zeolite samples have been tested to measure the membrane performances in the separation of hydrogen and water vapor from helium streams. These experiments were carried out in the ZIMT (Zeolite Inorganic Membranes for Tritium) facility where mass spectrometry and cold traps were used to measure the membranes’ performances. The membranes were tested at temperatures ranging from 25 °C up to 130 °C, at feed pressures between 1 and 3 bar, and typical feed flows of 2 l/min. During this experimental campaign, several zeolite-type membranes were studied: a hollow-fiber MFI nanocomposite membrane purchased from IRCELYON (France), and tubular MFI-ZSM5, NaA and H-SOD membranes purchased from Institute for Ceramic Technologies and Systems (IKTS, Germany). Among these membranes, only the MFI-based showed relevant performances for the H2/He separation, with rather high permeances (~0.5 – 0.7 μmol/sm2Pa for H2 at 25 °C for MFI-ZSM5), however with a limited ideal selectivity of around 2 for H2/He regardless of the feed concentration. Both MFI and NaA showed higher separation performances when water vapor was used instead; for example, at 30 °C, the separation factor for MFI-ZSM5 is approximately 10 and 38 for 0.2% and 10% H2O/He, respectively. The H-SOD evidenced to be considerably defective and therefore not considered for further experiments. In this contribution, a comprehensive analysis of the experimental methods and results obtained for the separation performance of different zeolite membranes during the past four years in inactive environment is given. These results are encouraging for the experimental campaign with molecular and oxidized tritium that will follow in 2017.

Keywords: gas separation, nuclear fusion, tritium processes, zeolite membranes

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146 Case of A Huge Retroperitoneal Abscess Spanning from the Diaphragm to the Pelvic Brim

Authors: Christopher Leung, Tony Kim, Rebecca Lendzion, Scott Mackenzie

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Retroperitoneal abscesses are a rare but serious condition with often delayed diagnosis, non-specific symptoms, multiple causes and high morbidity/mortality. With the advent of more readily available cross-sectional imaging, retroperitoneal abscesses are treated earlier and better outcomes are achieved. Occasionally, a retroperitoneal abscess is present as a huge retroperitoneal abscess, as evident in this 53-year-old male. With a background of chronic renal disease and left partial nephrectomy, this gentleman presented with a one-month history of left flank pain without any other symptoms, including fevers or abdominal pain. CT abdomen and pelvis demonstrated a huge retroperitoneal abscess spanning from the diaphragm, abutting the spleen, down to the iliopsoas muscle and abutting the iliac vessels at the pelvic brim. This large retroperitoneal abscess required open drainage as well as drainage by interventional radiology. A long course of intravenous antibiotics and multiple drainages was required to drain the abscess. His blood culture and fluid culture grew Proteus species suggesting a urinary source, likely from his non-functioning kidney, which had a partial nephrectomy. Such a huge retroperitoneal abscess has rarely been described in the literature. The learning point here is that the basic principle of source control and antibiotics is paramount in treating retroperitoneal abscesses regardless of the size of the abscess.

Keywords: retroperitoneal abscess, retroperitoneal mass, sepsis, genitourinary infection

Procedia PDF Downloads 193
145 Effect of Arbutus Pavarii ( Shemari ) Libyan Medical Plant on Ethylene Glycol Induced Urolithiasis in Male Albino Rats

Authors: Khaled. M.Benelhaj, Moada Elbadary

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The present investigation is carried out to evaluate the effect of aqueous extract of Arbutus Pavarii (Shemari) Libyan medical plant on ethylene glycol(EG) induce lithiasis in adult male albino rats. The lithiasis was induced to rats by oral administration of EG (0.75 w/v%) for 21 days(group 1). Aqueous extract of Shemari (200 mg/kg) was given orally from 1st day for preventive regimen (group 2) and from day 21st up to 42nd day for curative regimen (group 3). The results indicated that the EG elevated the urinary ionic of calcium, oxalates and inorganic phosphate. The Shemari significantly (P<0.01) reduced the levels of these ions. The histopathological findings showed that EG caused marked pathological changes in renal cortex; necrosis of glomerular tufts; mildy thickened bowman’s capsule and coagulative necrosis of large number of convoluted tubules. However, the histological changes in preventive regimen group 2 showed the same changes observed in group 1, but milder in severity and less in frequency. It conclude that Shemari do reduce the urinary ionic levels of calcium, oxalates and inorganic phosphate but failed to prevent complete deterioration effects of EG on kidney structures.

Keywords: EG, shamari, kidney stone, Libyan medical plant, glycol, oxalates

Procedia PDF Downloads 522
144 Protective Effect of Malva sylvestris L. against Sodium Fluoride-Induced Nephrotoxicity in Rat

Authors: Ali Babaei Zarch, S. Kianbakht, H. Fallah Huseini, P. Changaei, A. Mirjalili, J. Salehi

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Background: Malva sylvestris L. is widely used in the traditional medicine of Iran and other countries to treat gastrointestinal, respiratory, skin and urological Disorders. Moreover, it has antioxidant property. Objective: In this study the protective effect of Malva sylvestris against sodium fluoride-induced nephrotoxicity in rats were evaluated. Methods: The Malva sylvestris flower extract was injected intraperitoneally at the doses of 100, 200, 400 mg/kg/day to groups of rats ( 10 in each group) for 1 week and subsequently 600 ppm sodium fluoride was added daily to the rats drinking water for 1 additional week. After these steps, the rats’ serum levels of urea, creatinine, reduced glutathione, catalase and malondialdehyde were determined. The histopathology of the rats’ kidney was also studied. Results: Malva sylvesteries extract with doses of 400 mg/kg/day significantly decreased the urea and creatinine levels (P<0.05). Moreover, the levels of catalase and glutathione were increased by this dose, but only the catalase increase was statistically significant (P<0.05). All three extract doses of Malva decreased the malondialdehyde level, but it was significant only for the dose 400 mg/kg/day (P<0.05). Histopathological findings also showed a protective effect of Malva against renal damage induced by sodium fluoride. Conclusion: The results suggest that Malva sylvestris has a protective effect against sodium fluoride-induced nephrotoxicity through its antioxidant property.

Keywords: Malva sylvestris, mephrotoxicity, sodium fluoride, rat  

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143 Collapse Analysis of Planar Composite Frame under Impact Loads

Authors: Lian Song, Shao-Bo Kang, Bo Yang

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Concrete filled steel tubular (CFST) structure has been widely used in construction practices due to its superior performances under various loading conditions. However, limited studies are available when this type of structure is subjected to impact or explosive loads. Current methods in relevant design codes are not specific for preventing progressive collapse of CFST structures. Therefore, it is necessary to carry out numerical simulations on CFST structure under impact loads. In this study, finite element analyses are conducted on the mechanical behaviour of composite frames which composed of CFST columns and steel beams subject to impact loading. In the model, CFST columns are simulated using finite element software ABAQUS. The model is verified by test results of solid and hollow CFST columns under lateral impacts, and reasonably good agreement is obtained through comparisons. Thereafter, a multi-scale finite element modelling technique is developed to evaluate the behaviour of a five-storey three-span planar composite frame. Alternate path method and direct simulation method are adopted to perform the dynamic response of the frame when a supporting column is removed suddenly. In the former method, the reason for column removal is not considered and only the remaining frame is simulated, whereas in the latter, a specific impact load is applied to the frame to take account of the column failure induced by vehicle impact. Comparisons are made between these two methods in terms of displacement history and internal force redistribution, and design recommendations are provided for the design of CFST structures under impact loads.

Keywords: planar composite frame, collapse analysis, impact loading, direct simulation method, alternate path method

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142 An Automated Procedure for Estimating the Glomerular Filtration Rate and Determining the Normality or Abnormality of the Kidney Stages Using an Artificial Neural Network

Authors: Hossain A., Chowdhury S. I.

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Introduction: The use of a gamma camera is a standard procedure in nuclear medicine facilities or hospitals to diagnose chronic kidney disease (CKD), but the gamma camera does not precisely stage the disease. The authors sought to determine whether they could use an artificial neural network to determine whether CKD was in normal or abnormal stages based on GFR values (ANN). Method: The 250 kidney patients (Training 188, Testing 62) who underwent an ultrasonography test to diagnose a renal test in our nuclear medical center were scanned using a gamma camera. Before the scanning procedure, the patients received an injection of ⁹⁹ᵐTc-DTPA. The gamma camera computes the pre- and post-syringe radioactive counts after the injection has been pushed into the patient's vein. The artificial neural network uses the softmax function with cross-entropy loss to determine whether CKD is normal or abnormal based on the GFR value in the output layer. Results: The proposed ANN model had a 99.20 % accuracy according to K-fold cross-validation. The sensitivity and specificity were 99.10 and 99.20 %, respectively. AUC was 0.994. Conclusion: The proposed model can distinguish between normal and abnormal stages of CKD by using an artificial neural network. The gamma camera could be upgraded to diagnose normal or abnormal stages of CKD with an appropriate GFR value following the clinical application of the proposed model.

Keywords: artificial neural network, glomerular filtration rate, stages of the kidney, gamma camera

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141 Numerical Analysis of Solar Cooling System

Authors: Nadia Allouache, Mohamed Belmedani

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Energy source is a sustainable, totally inexhaustible and environmentally friendly alternative to the fossil fuels available. It is a renewable and economical energy that can be harnessed sustainably over the long term and thus stabilizes energy costs. Solar cooling technologies have been developed to decrease the augmentation electricity consumption for air conditioning and to displace the peak load during hot summer days. A numerical analysis of thermal and solar performances of an annular finned adsorber, which is the most important component of the adsorption solar refrigerating system, is considered in this work. Different adsorbent/adsorbate pairs, such as activated carbon AC35/methanol, activated carbon AC35/ethanol, and activated carbon BPL/Ammoniac, are undertaken in this study. The modeling of the adsorption cooling machine requires the resolution of the equation describing the energy and mass transfer in the tubular finned adsorber. The Wilson and Dubinin- Astakhov models of the solid-adsorbate equilibrium are used to calculate the adsorbed quantity. The porous medium and the fins are contained in the annular space, and the adsorber is heated by solar energy. Effects of key parameters on the adsorbed quantity and on the thermal and solar performances are analysed and discussed. The AC35/methanol pair is the best pair compared to BPL/Ammoniac and AC35/ethanol pairs in terms of system performance. The system performances are sensitive to the fin geometry. For the considered data measured for clear type days of July 2023 in Algeria and Morocco, the performances of the cooling system are very significant in Algeria.

Keywords: activated carbon AC35-methanol pair, activated carbon AC35-ethanol pair, activated carbon BPL-ammoniac pair, annular finned adsorber, performance coefficients, numerical analysis, solar cooling system

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140 Lack of Functional Interaction between Nitric Oxide and ET-A Receptors in Cisplatin-Induced Acute Renal Failure

Authors: Mai M. Helmy

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Although the role of either nitric oxide (NO) or endothelin receptors modulation in the severity of cisplatin-induced nephrotoxicity has been recognized in previous studies including our own, the possible interaction between the two pathways remains obscure. In this study, we tested the possible interaction between the nitrergic and endothelin pathways in cisplatin-induced nephrotoxicity in male rats. Sprague Dawley male rats (200 to 250 g) were divided into four groups: Control (given a single dose of normal saline, i.p.), cisplatin (6 mg/kg, i.p.), cisplatin+Sildenafil (2 mg/kg, i.p.), cisplatin+Sildenafil+BQ-123 (1 mg/kg, i.p.). Each of the co-administered drugs was given in two doses; one hour before and one day after the cisplatin dose. Acute cisplatin administration resulted in significant increases in BUN and serum creatinine levels at 96 h following cisplatin injection. Increased levels of MDA, TNF-α and caspase-3, decreased nitrite/nitrate level and SOD activity in kidney homogenates were also observed following cisplatin injection. According to the obtained results, the co-adminstration of sildenafil alone with cisplatin offered a reno-protective effect comparable to that obtained following the concurrent administration of both sildenafil and the selective ETAR antagonist BQ-123. Thus, the current study is the first to reveal that the presence of an intact NO/cGMP system may offer a moderate reno-protective effect against cisplatin-induced nephrotoxicity even in the presence of ETAR-mediated vasoconstriction, suggesting the absence of obvious functional interaction between the nitrergic and endothelin pathways in cisplatin-induced nephrotoxicity in male rats.

Keywords: BQ-123, cisplatin, endothelin-1, nephrotoxicity, sildenafil

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139 VHL, PBRM1, and SETD2 Genes in Kidney Cancer: A Molecular Investigation

Authors: Rozhgar A. Khailany, Mehri Igci, Emine Bayraktar, Sakip Erturhan, Metin Karakok, Ahmet Arslan

Abstract:

Kidney cancer is the most lethal urological cancer accounting for 3% of adult malignancies. VHL, a tumor-suppressor gene, is best known to be associated with renal cell carcinoma (RCC). The VHL functions as negative regulator of hypoxia inducible factors. Recent sequencing efforts have identified several novel frequent mutations of histone modifying and chromatin remodeling genes in ccRCC (clear cell RCC) including PBRM1 and SETD2. The PBRM1 gene encodes the BAF180 protein, which involved in transcriptional activation and repression of selected genes. SETD2 encodes a histone methyltransferase, which may play a role in suppressing tumor development. In this study, RNAs of 30 paired tumor and normal samples that were grouped according to the types of kidney cancer and clinical characteristics of patients, including gender and average age were examined by RT-PCR, SSCP and sequencing techniques. VHL, PBRM1 and SETD2 expressions were relatively down-regulated. However, statistically no significance was found (Wilcoxon signed rank test, p > 0.05). Interestingly, no mutation was observed on the contrary of previous studies. Understanding the molecular mechanisms involved in the pathogenesis of RCC has aided the development of molecular-targeted drugs for kidney cancer. Further analysis is required to identify the responsible genes rather than VHL, PBRM1 and SETD2 in kidney cancer.

Keywords: kidney cancer, molecular biomarker, expression analysis, mutation screening

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138 Molecular Detection of Viruses Causing Hemorrhagic Fevers in Rodents in the South-West of Korea

Authors: Sehrish Jalal, Choon-Mee Kim, Dong-Min Kim

Abstract:

Background: Many pathogens causing hemorrhagic fevers of medical and veterinary importance have been identified and isolated from rodents in the Republic of Korea (ROK). Objective: We investigated the prevalence of emerging viruses causing hemorrhagic fevers, such as hemorrhagic fever with renal syndrome (HFRS), severe fever with thrombocytopenia syndrome (SFTS) and flaviviruses, from wild rodents. Methods: Striped field mice, Apodemus agrarius, (n=39) were captured during 2014-2015 in the south-west of ROK. Using molecular methods, lung samples were evaluated for SFTS virus, HFRS virus and flavivirus, and seropositivity was evaluated in the blood. Results: A high positive rate of Hantavirus (46.2%) was detected in A.agrarius lungs by reverse transcription-nested polymerase chain reaction (RT-N-PCR). The monthly prevalence of HFRS virus was 16.7% in October, 86.7% in November and 25% in August of the following year (p < 0.001). Moreover, 17.9% of blood samples were serologically positive for Hantavirus antibodies. The most prevalent strain in A. agrarius was Hantaan virus. All samples were positive for neither SFTS nor flavivirus. Conclusion: Hantan virus was detected in 86.7% of A. agrarius in November (autumn), and thus, virus shedding from A. agrarius can increase the risk of humans contracting HFRS. These findings may help to predict and prevent disease outbreaks in ROK.

Keywords: hemorrhagic fever virus, molecular diagnostic technique, rodents, Korea

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137 A Study of the Prevalence of Hypertension and Pre Hypertension in Adolescence Age between 10-17 in Ahvaz (2008-2009)

Authors: Armaghan Moravej Aleali, Seyed Mahmoud Latifi, Homeira Rashidi

Abstract:

Objective: High blood pressure in a risk factor for some disease like stroke, coronary heart disease, and renal failure. High blood pressure in children is an increasing health problem. The aim of this present was to determine prevalence of hypertension and pre-hypertension age between 10 to 17 years old. Material & Methods: This descriptive-analytic study was conducted using multiphase sampling method in Ahvaz (Southwest of Iran). A questionnaire include: height, weight, and body mass index, systolic and diastolic blood pressures filled for each participant. Blood pressure was measured twice for each person. For the diagnosis of hypertension, the fourth report of the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents of the National Health Institute of United States was used. Results: The subject participants of the study were 1707children and adolescents including 922 boys (54%) and 785 girls 46%). The prevalence of high blood pressure was 1.7% (boys 2.5% girls 0.8%). The prevalence of pre-hypertension was 9 % (7.6% in boys, 10.6% in girls). The mean systolic and diastolic blood pressures increased with increasing body mass index. Conclusion: In this study, the prevalence of high blood pressure was found to be lower than other studies in our country. The prevalence of the high blood pressure in boys was significantly higher than girls. This study, like other studies, showed a high correlation between being overweight and an increase in systolic and diastolic blood pressure.

Keywords: hypertension, pre-hypertension, childhood, adolescence

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136 Recovery of Selenium from Scrubber Sludge in Copper Process

Authors: Lakshmikanth Reddy, Bhavin Desai, Chandrakala Kari, Sanjay Sarkar, Pradeep Binu

Abstract:

The sulphur dioxide gases generated as a by-product of smelting and converting operations of copper concentrate contain selenium apart from zinc, lead, copper, cadmium, bismuth, antimony, and arsenic. The gaseous stream is treated in waste heat boiler, electrostatic precipitator and scrubbers to remove coarse particulate matter in order to produce commercial grade sulfuric acid. The gas cleaning section of the acid plant uses water to scrub the smelting gases. After scrubbing, the sludge settled at the bottom of the scrubber, was analyzed in present investigation. It was found to contain 30 to 40 wt% copper and selenium up to 40 wt% selenium. The sludge collected during blow-down is directly recycled to the smelter for copper recovery. However, the selenium is expected to again vaporize due to high oxidation potential during smelting and converting, causing accumulation of selenium in sludge. In present investigation, a roasting process has been developed to recover the selenium before the copper recovery from the sludge at smelter. Selenium is associated with copper in sludge as copper selenide, as determined by X-ray diffraction and electron microscopy. The thermodynamic and thermos-gravimetry study revealed that the copper selenide phase present in the sludge was amenable to oxidation at 600°C forming oxides of copper and selenium (Cu-Se-O). However, the dissociation of selenium from the copper oxide was made possible by sulfatation using sulfur dioxide between 450 to 600°C, resulting into the formation of CuSO₄ (s) and SeO₂ (g). Lab scale trials were carried out in vertical tubular furnace to determine the optimum roasting conditions with respect to roasting time, temperature and molar ratio of O₂:SO₂. Using these optimum conditions, selenium up to 90 wt% in the form of SeO₂ vapors could be recovered from the sludge in a large-scale commercial roaster. Roasted sludge free from the selenium and containing oxides and sulfates of copper could now be recycled in the smelter for copper recovery.

Keywords: copper, selenium, copper selenide, sludge, roasting, SeO₂

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135 Toxicity of Acacia nilotica ( Garad) to Nubian Goats

Authors: B. Medani Amna, M. A. Elbadwi Samia, E. Amin Ahmed

Abstract:

Variable plants present in nature are used by simple rural and urban people, researchers and drug manufacturers for medicinal purposes. Garad is one of the most commonly used in Sudan for both treatment and prophylaxis of infections in the respiratory, urinogenital tracts and the skin. Water exctracts from Acacia nilotica bods were used in this very experiment to test for their toxicity to Nubian goats at two dose rates under proper experimental conditions. The clinical, pathological, haematological and biological changes in Nubian goats given daily oral doses of 1 and 5 g/kg body weight of Acacia nilotica to two groups of test goats. The goats of the control group were undosed with Acacia nilotica.Other than the dose co-related mortality rates, the clinical signs were observed to be salivation, staggered gait, intermittent loss of voice and low appetite. On histopathological testing, the main lesions were hepatic centrolobular necrosis and fatty changes associated with the significant changes in GGT and ALP are indicating hepatic dysfunction.Renal malfunction is indicated by haemorrhages in addition to the change in the urea concentration. The congested, haemorrhagic, emphysematous, edematous and cyanotic lungs may contribute to the development of dyspnea. Acacia nilotica poisoning may lead to an immunosuppression pointed out by the lymphocyte infiltration. On evaluation of the above results, Acacia nilotica was considered toxic to Nubian goats at the above mentioned doses. Future work for Acacia nilotica was forwarded and practical implications of the result were highlighted.

Keywords: Acaia nilotica, toxicity data, Nubian goats, Garad

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134 Apollo Clinical Excellence Scorecard (ACE@25): An Initiative to Drive Quality Improvement in Hospitals

Authors: Anupam Sibal

Abstract:

Whatever is measured tends to improve. With a view to objectively measuring and improving clinical quality across the Apollo Group Hospitals, the initiative of ACE @ 25 (Apollo Clinical Excellence@25) was launched on Jan 09. ACE @ 25 is a clinically balanced scorecard incorporating 25 clinical quality parameters involving complication rates, mortality rates, one-year survival rates and average length of stay after major procedures like liver and renal transplant, CABG, TKR, THR, TURP, PTCA, endoscopy, large bowel resection and MRM covering all major specialties. Also included are hospital acquired infection rates, pain satisfaction and medication errors. Benchmarks have been chosen from the world’s best hospitals. There are weighted scores for outcomes color coded green, orange and red. The cumulative score is 100. Data is reported monthly by 43 Group Hospitals online on the Lighthouse platform. Action taken reports for parameters falling in red are submitted quarterly and reviewed by the board. An audit team audits the data at all locations every six months. Scores are linked to appraisal of the medical head and there is an “ACE @ 25” Champion Award for the highest scorer. Scores for different parameters were variable from green to red at the start of the initiative. Most hospitals showed an improvement in scores over the last four years for parameters where they had showed scores in red or orange at the start of the initiative. The overall scores for the group have shown an increase from 72 in 2010 to 81 in 2015.

Keywords: benchmarks, clinical quality, lighthouse, platform, scores

Procedia PDF Downloads 268
133 Adverse Effects of Natural Pesticides on Human and Animals: An Experimental Analysis

Authors: Abdel-Tawab H. Mossa

Abstract:

Synthetic pesticides are widely used in large-scale worldwide for control pests in agriculture and public health sectors in both developed and developing countries. Although the positive role of pesticides, they have many adverse toxic effects on humans, animals, and the ecosystem. Therefore, in the last few years, scientists have been searching for new active compounds from natural resources as an alternative to synthetic pesticides. Currently, many commercial natural pesticides are available commercially worldwide. These products are recommended for uses in organic farmers and considered as safe pesticides. This paper focuses on the adverse effects of natural pesticides on mammals. Available commercial pesticides in the market contain essential oils (e.g. pepper, cinnamon, and garlic), plant extracts, microorganism (e.g. bacteria, fungi or their toxin), mineral oils and some active compounds from natural recourses e.g. spinosad, neem, pyrethrum, rotenone, abamectin and other active compounds from essential oils (EOs). Some EOs components, e.g., thujone, pulegone, and thymol have high acute toxicity (LD50) is 87.5, 150 and 980 mg/kg. B.wt on mice, respectively. Natural pesticides such as spinosad, pyrethrum, neem, abamectin, and others have toxicological effects to mammals and ecosystem. These compounds were found to cause hematotoxicity, hepato-renal toxicity, biochemical alteration, reproductive toxicity, genotoxicity, and mutagenicity. It caused adverse effects on the ecosystem. Therefore, natural pesticides in general not safe and have high acute toxicity and can induce adverse effects at long-term exposure.

Keywords: natural pesticides, toxicity, safety, genotoxicity, ecosystem, biochemical

Procedia PDF Downloads 140
132 Thermal and Solar Performances of Adsorption Solar Refrigerating Machine

Authors: Nadia Allouache

Abstract:

Solar radiation is by far the largest and the most world’s abundant, clean and permanent energy source. The amount of solar radiation intercepted by the Earth is much higher than annual global energy use. The energy available from the sun is greater than about 5200 times the global world’s need in 2006. In recent years, many promising technologies have been developed to harness the sun's energy. These technologies help in environmental protection, economizing energy, and sustainable development, which are the major issues of the world in the 21st century. One of these important technologies is the solar cooling systems that make use of either absorption or adsorption technologies. The solar adsorption cooling systems are good alternative since they operate with environmentally benign refrigerants that are natural, free from CFCs, and therefore they have a zero ozone depleting potential (ODP). A numerical analysis of thermal and solar performances of an adsorption solar refrigerating system using different adsorbent/adsorbate pairs such as activated carbon AC35 and activated carbon BPL/Ammoniac; is undertaken in this study. The modeling of the adsorption cooling machine requires the resolution of the equation describing the energy and mass transfer in the tubular adsorber that is the most important component of the machine. The Wilson and Dubinin- Astakhov models of the solid-adsorbat equilibrium are used to calculate the adsorbed quantity. The porous medium is contained in the annular space and the adsorber is heated by solar energy. Effect of key parameters on the adsorbed quantity and on the thermal and solar performances are analysed and discussed. The performances of the system that depends on the incident global irradiance during a whole day depends on the weather conditions: the condenser temperature and the evaporator temperature. The AC35/methanol pair is the best pair comparing to the BPL/Ammoniac in terms of system performances.

Keywords: activated carbon-methanol pair, activated carbon-ammoniac pair, adsorption, performance coefficients, numerical analysis, solar cooling system

Procedia PDF Downloads 40
131 Evaluation of Malva sylvestris L. Effect on Sodium Fluoride-Induced Nephrotoxicity in Rat

Authors: A. Babaei Zarch, S. Kianbakht, H. Fallah Huseini, P. Changaei, A. Mirjalili, J. Salehi

Abstract:

Background: Malva Sylvestris L. has antioxidant property and is widely used in the traditional medicine to treat gastrointestinal, respiratory, skin and urological disorders. Objective: In this study the protective effect of Malva Sylvestris against sodium fluoride-induced nephrotoxicity in rat were evaluated. Methods: The Malva Sylvestris flower extract was prepared and injected intraperitoneally at the doses of 100, 200, 400 mg/kg/day to group of rats ( 10 in each group) for 1 week and subsequently 600 ppm sodium fluoride was added to the rats drinking water for 1 additional week. After these steps, the rats’ serum levels of urea, creatinine, reduced glutathione, catalase and malondialdehyde were determined. The histopathologies of the rats’ kidneys were also studied. Results: Sodium fluoride administration increased levels of BUN, creatinine glutathione, catalase activity and decreased malondialdehyde indicating induction of nephrotoxicity in rats. Malva Sylvestris extract pretreatment significantly decreased the BUN and creatinine levels (P<0.05). Moreover, the levels of catalase and glutathione were increased by Malva, and this increase were also statistically significant (P<0.05). All three doses of Malva extract decreased the malondialdehyde level, but it was significant only for the doses of 200 and 400 mg/kg/day (P<0.05). Histopathological findings also showed protective effect of Malva against renal damage induced by sodium fluoride. Conclusion: The results suggest that Malva Sylvestris has protective effect against sodium fluoride-induced nephrotoxicity maybe mediated by its antioxidant property.

Keywords: malva sylvestris, nephrotoxicity, sodium fluoride, rat

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130 Great Food, No Atmosphere: A Review of Performance Nutrition for Application to Extravehicular Activities in Spaceflight

Authors: Lauren E. Church

Abstract:

Background: Extravehicular activities (EVAs) are a critical aspect of missions aboard the International Space Station (ISS). It has long been noted that the spaceflight environment and the physical demands of EVA cause physiological and metabolic changes in humans; this review aims to combine these findings with nutritional studies in analogues of the spaceflight and EVA environments to make nutritional recommendations for astronauts scheduled for and immediately returning from EVAs. Results: Energy demands increase during orbital spaceflight and see further increases during EVA. Another critical element of EVA nutrition is adequate hydration. Orbital EVA appears to provide adequate hydration under current protocol, but during lunar surface EVA (LEVA) and in a 10km lunar walk-back test astronauts have stated that up to 20% more water was needed. Previous attempts for in-suit edible sustenance have not been adequately taken up by astronauts to be economically viable. In elite endurance athletes, a mixture of glucose and fructose is used in gels, improving performance. Discussion: A combination of non-caffeinated energy drink and simple water should be available for astronauts during EVA, allowing more autonomy. There should also be provision of gels or a similar product containing appropriate sodium levels to maintain hydration, but not so much as to hyperhydrate through renal water reabsorption. It is also suggested that short breaks be built into the schedule of EVAs for these gels to be consumed, as it is speculated that reason for low uptake of in-suit sustenance is the lack of time available in which to consume it.

Keywords: astronaut, nutrition, space, sport

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129 Angiogenic Potential of Collagen Based Biomaterials Implanted on Chick Embryo Chorioallantoic Membrane as Alternative Microenvironment for in Vitro and in Vivo Angiogenesis Assays

Authors: Anca Maria Cimpean, Serban Comsa

Abstract:

Chick embryo chorioallantoic membrane (CAM) is a well vascularised in vivo experimental model used as a platform for testing the behavior of different implants inserted on it from tumor fragments to therapeutic agents or various biomaterials. Five types of collagen-based biomaterials with 2D and 3D structure (MotifMesh, Optimaix2D, Optimaix3D, Dual Layer Collagen and Xenoderm) were implanted on CAM and continuously evaluated by stereomicroscope for up to 5 days post-implant with an emphasis of their ability to requisite and develop new blood vessels (BVs) followed by microscopic analysis. MotifMEsh did not induce any angiogenic response lacking to be invaded by BVs from the CAM, but it induced intense inflammatory response necrosis and fibroblastic reaction around the implant. Optimaix2D has good adherence. CAM with minimal or no inflammatory reaction, a good integration of the CAM between the collagen mesh’s fibers, consistent adhesion of the cells to the collagen fibers,and a good ability to form pseudo-vascular channels filled with cells. Optimaix3D induced the highest angiogenic effects on CAM. The material shows good integration on CAM. The collagen fibers of the material show the ability to organize themselves into linear and tubular structures. It is possible to see blood elements, especially at the periphery of the implant. Dual-layer collagen behaves similar to Optimaix 3D, while Xenoderm induced a moderate angiogenic effect on CAM. Based on these data, we may conclude that collagen-based materials have variable ability to requisite and develop new blood vessels. A proper selection of collagen-based biomaterial scaffolds may crucially influence the acquisition and development of blood vessels during angiogenesis assays.

Keywords: chick embryo chorioallantoic membrane, collagen scaffolds, blood vessels, vascular microenvironment

Procedia PDF Downloads 155
128 Endovascular Aneurysm Repair (Evar) with Endoanchors: For Tandem Aortic Abdominal Aneurysm (Aaa) with Hostile Neck & Proximal Penetrating Atherosclerotic Ulcer

Authors: Von Jerick Tenorio, Jonald Lucero, Marivic Vestal, Edwin Tiempo

Abstract:

In patients with hostile aortic neck anatomy, the risks of proximal seal complications and stent migration remain with EVAR despite improved endograft technology. This case report discusses how the technical challenges of the hostile neck anatomy, proximal penetrating atherosclerotic ulcer (PAU) and tortuous femoral access were addressed. The CT aortogram of a 63-year-old hypertensive and diabetic man with recurring abdominal discomfort revealed a fusiform infra-renal aneurysm measuring 8.8 cm in length and 5.7 cm in diameter. The proximal landing zone only has a 3 mm healthy neck with a conicity of > 10% and a thrombus of 4 mm thick. Proximal to the aneurysm is a PAU with a circumferential mural thrombus. The right femoral artery is tortuous with > 90o angulation. A 20% oversized Endurant II endograft and Aptus Heli-FX EndoAnchors were deployed as prophylaxis for type I endoleaks and endograft migration consequent to the conical neck and proximal aneurysm extension consequent to the PAU. A stiff Backup Meier guide wire facilitated the deployment of the endograft. Coil embolization of the right internal iliac artery was performed as prophylaxis for type II endoleaks. EndoAnchors can be used as an adjunct to EVAR as prophylaxis for proximal seal complications and stent migration in patients with hostile aortic aneurysm neck anatomy and concomitant proximal PAU.

Keywords: endoAnchors, endoleaks, EVAR, hostile neck

Procedia PDF Downloads 170
127 Sustainable Development of Adsorption Solar Cooling Machine

Authors: N. Allouache, W. Elgahri, A. Gahfif, M. Belmedani

Abstract:

Solar radiation is by far the largest and the most world’s abundant, clean and permanent energy source. The amount of solar radiation intercepted by the Earth is much higher than annual global energy use. The energy available from the sun is greater than about 5200 times the global world’s need in 2006. In recent years, many promising technologies have been developed to harness the sun's energy. These technologies help in environmental protection, economizing energy, and sustainable development, which are the major issues of the world in the 21st century. One of these important technologies is the solar cooling systems that make use of either absorption or adsorption technologies. The solar adsorption cooling systems are a good alternative since they operate with environmentally benign refrigerants that are natural, free from CFCs, and therefore they have a zero ozone depleting potential (ODP). A numerical analysis of thermal and solar performances of an adsorption solar refrigerating system using different adsorbent/adsorbate pairs, such as activated carbon AC35 and activated carbon BPL/Ammoniac; is undertaken in this study. The modeling of the adsorption cooling machine requires the resolution of the equation describing the energy and mass transfer in the tubular adsorber, that is the most important component of the machine. The Wilson and Dubinin- Astakhov models of the solid-adsorbat equilibrium are used to calculate the adsorbed quantity. The porous medium is contained in the annular space, and the adsorber is heated by solar energy. Effect of key parameters on the adsorbed quantity and on the thermal and solar performances are analysed and discussed. The performances of the system that depends on the incident global irradiance during a whole day depends on the weather conditions: the condenser temperature and the evaporator temperature. The AC35/methanol pair is the best pair comparing to the BPL/Ammoniac in terms of system performances.

Keywords: activated carbon-methanol pair, activated carbon-ammoniac pair, adsorption, performance coefficients, numerical analysis, solar cooling system

Procedia PDF Downloads 52