Search results for: stress effect

Authors: Karen L. Lindsay, Sonja Entringer, Claudia Buss, Pathik D. Wadhwa

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Maternal nutrition and stress are independently recognized as among the most important factors that influence prenatal biology, with implications for fetal development and poor pregnancy outcomes. While there is substantial evidence from non-pregnancy human and animal studies that a complex, bi-directional relationship exists between nutrition and stress, to the author’s best knowledge, their interaction in the context of pregnancy has been significantly understudied. The aim of this study is to assess the interaction between maternal psychological stress and diet quality across pregnancy and its effects on biomarkers of prenatal insulin resistance and inflammation. This is a prospective longitudinal study of N=235 women carrying a healthy, singleton pregnancy, recruited from prenatal clinics of the University of California, Irvine Medical Center. Participants completed a 4-day ambulatory assessment in early, middle and late pregnancy, which included multiple daily electronic diary entries using Ecological Momentary Assessment (EMA) technology on a dedicated study smartphone. The EMA diaries gathered moment-level data on maternal perceived stress, negative mood, positive mood and quality of social interactions. The numerical scores for these variables were averaged across each study time-point and converted to Z-scores. A single composite variable for 'STRESS' was computed as follows: (Negative mood+Perceived stress)–(Positive mood+Social interaction quality). Dietary intakes were assessed by three 24-hour dietary recalls conducted within two weeks of each 4-day assessment. Daily nutrient and food group intakes were averaged across each study time-point. The Alternative Healthy Eating Index adapted for pregnancy (AHEI-P) was computed for early, middle and late pregnancy as a validated summary measure of diet quality. At the end of each 4-day ambulatory assessment, women provided a fasting blood sample, which was assayed for levels of glucose, insulin, Interleukin (IL)-6 and Tumor Necrosis Factor (TNF)-α. Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) was computed. Pearson’s correlation was used to explore the relationship between maternal STRESS and AHEI-P within and between each study time-point. Linear regression was employed to test the association of the stress-diet interaction (STRESS*AHEI-P) with the biological markers HOMA-IR, IL-6 and TNF-α at each study time-point, adjusting for key covariates (pre-pregnancy body mass index, maternal education level, race/ethnicity). Maternal STRESS and AHEI-P were significantly inversely correlated in early (r=-0.164, p=0.018) and mid-pregnancy (-0.160, p=0.019), and AHEI-P from earlier gestational time-points correlated with later STRESS (early AHEI-P x mid STRESS: r=-0.168, p=0.017; mid AHEI-P x late STRESS: r=-0.142, p=0.041). In regression models, the interaction term was not associated with HOMA-IR or IL-6 at any gestational time-point. The stress-diet interaction term was significantly associated with TNF-α according to the following patterns: early AHEI-P*early STRESS vs early TNF-α (p=0.005); early AHEI-P*early STRESS vs mid TNF-α (p=0.002); early AHEI-P*mid STRESS vs mid TNF-α (p=0.005); mid AHEI-P*mid STRESS vs mid TNF-α (p=0.070); mid AHEI-P*late STRESS vs late TNF-α (p=0.011). Poor diet quality is significantly related to higher psychosocial stress levels in pregnant women across gestation, which may promote inflammation via TNF-α. Future prenatal studies should consider the combined effects of maternal stress and diet when evaluating either one of these factors on pregnancy or infant outcomes.

Keywords: diet quality, inflammation, insulin resistance, nutrition, pregnancy, stress, tumor necrosis factor-alpha

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Authors: Shigeyuki Haruyama, I Made Gatot Karohika, Akinori Sato, Didik Nurhadiyanto, Ken Kaminishi

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Contact width and contact stress are important design parameters for optimizing corrugated metal gasket performance based on elastic and plastic contact stress. In this study, we used a three-layer metal gasket with Al, Cu, Ni as the outer layer, respectively. A finite element method was employed to develop simulation solution. The gasket model was simulated by using two simulation stages which are forming and tightening simulation. The simulation result shows that aluminum with tangent modulus, Ehal = Eal/150 has the highest slope for contact width. The slope of contact width for plastic mode gasket was higher than the elastic mode gasket.

Keywords: contact width, contact stress, layer, metal gasket, corrugated, simulation

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Authors: A. Chellil, A. Nour, S. Lecheb , H. Mechakra, L. Addar, H. Kebir

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This paper present a mechanical characteristics on fatigue crack propagation in Aluminium Plate based on strain and stress distribution using the abaqus software. The changes in shear strain and stress distribution during the fatigue cycle with crack growth is identified. In progressive crack in the strain distribution and the stress is increase in the critical zone. Numerical Modal analysis of the model developed, prove that the Eigen frequencies of aluminium plate were decreased after cracking, and this reduce is nonlinear. These results can provide a reference for analysts and designers of aluminium alloys in aeronautical systems. Therefore, the modal analysis is an important factor for monitoring the aeronautic structures.

Keywords: aluminum alloys, plate, crack, failure

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Authors: Adnan I. O. Zaid

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Zinc aluminum alloys are versatile materials which are widely used in manufacturing several parts in the automobile and aircraft industries. The effect of grain refinement of these alloys by rare earth elements on their mechanical characteristics is scarce. The equal channel angular pressing is relatively recent method for producing severe plastic deformation in materials subjected to it resulting in refinement of their structure and enhancement of their mechanical characteristics. The phase diagram of these alloys indicates that large dendrites of large grain size can be formed during their solidification of the cast which tends to deteriorate their mechanical strength and surface quality. To overcome this problem they are normally grain refined by either titanium or titanium + boron to their melt prior to solidification. In this paper, comparison between the effect of adding either titanium, (Ti), titanium+boron, (Ti+B), or Molybdenum, Mo, to zinc-aluminum22, alloy, (ZA22) on its metallurgical and mechanical characteristics in the cast condition and after pressing by the ECAP process is investigated. It was found that addition of either Ti, Ti+B, or Mo to the ZA22 alloy in the cast condition resulted in refining of their structure being more refined by the addition of Mo, then .Ti+B and less refining by Ti addition. Furthermore, the ECAP process resulted in further refinement of the alloy micro structure except in case of Ti+B addition where poisoning i.e. coarsening of the grains has occurred. Regarding the addition of these element on the mechanical behavior; it was found that addition of Ti Or Ti+B resulted in little enhancement of the alloy strength factor and its flow stress at 20% true strain; whereas, the addition of resulted in deteriorating of its mechanical behavior as % decrease in the strength factor and % in its flow stress of 20%. As for the strain hardening index; addition of any of these elements resulted in decreasing the strain hardening index.

Keywords: addition, grain refinement, mechanical characteristics, microstructure, rare earth elements, ZA-22, Zinc- aluminum alloy

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Authors: H. Babou, S. Ridjla, B. Amerate, R. Ferhoum, M. Aberkane

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This work is devoted to the experimental study of thermal ageing effect on the mechanical and micro structural behavior of polycarbonate (PC). A simple compression tests, micro hardness and an IRTF analysis were completed in order to characterize the response of material on specimens after ageing at a temperature of order 100 C° and for serval maintain duration 72, 144 and 216 hours. These investigations showed a decrease of the intrinsic properties of polycarbonate (Young modulus, yield stress, etc.); the superposition of spectra IRTF shows that the intensity of chemical connections C=C, C-O, CH3 and C-H are influenced by the duration of thermal ageing; in addition, an increase of 30 % of micro hardness was detected after 216 hour of ageing.

Keywords: amorphous polymer, polycarbonate, mechanical behavior, compression test, thermal ageing

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Authors: Ali Muhammad

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The purpose of this study is to examine the effect of employees’ perception of political behavior on their behavior and attitudes. The model tested in this study suggests that employees’ perception of political behavior in their organizations leads to lower levels of job satisfaction, and organizational commitment, and higher levels of work-related stress, and intentions to leave the organization. A sample of 182 employees working in six Kuwaiti business organizations were surveyed using a questionnaire, and data was analyzed using correlation analysis, regression analysis, and non-parametric tests. Results reveal that employees’ perception of political behavior is negatively associated with job satisfaction and organizational commitment, and positively associated with work-related stress and employees’ intentions to leave the organization. The results of the current study are discussed and are compared to the results of previous studies in this area. Finally, the directions for future research are suggested.

Keywords: perceptions of political behavior, organizational commitment, job satisfaction, intention to leave

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Authors: Minhui Chiu

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According to relevant studies, clinical nurses have high work pressure and relatively high job adaptation needs. The nurses who work in oncology wards have more adaptation needs when they face repeating hospitalization patients. The aims of this study were to investigate the job stress adaptation and related factors of nurses in oncology wards and to understand the predictors of job stress adaptation needs. Convenience sampling was used in this study. The nurses in the oncology specialist ward of a regional teaching hospital in southern Taiwan were selected as the research objects. A cross-sectional survey was conducted using a structured questionnaire, random sampling, and the questionnaires were filled out by the participating nurses. A total of 68 people were tested, and 65 valid questionnaires (95.6%). One basic data questionnaire and nurses’ job stress adaptation needs questionnaire were used. The data was archived with Microsoft Excel, and statistical analysis was performed with JMP12.0. The results showed that the average age was 28.8 (±6.7) years old, most of them were women, 62 (95.38%), and the average clinical experience in the hospital was 5.7 years (±5.9), and 62 (95.38%) were university graduates. 39 people (60.0%) had no work experience. 39 people (60.0%) liked nursing work very much, and 23 people (35.3%) just “liked”. 47 (72.3%) people were supported to be oncology nurses by their families. The nurses' job stress adaptation needs were 119.75 points (±17.24). The t-test and variance analysis of the impact of nurses' job pressure adaptation needs were carried out. The results showed that the score of college graduates was 121.10 (±16.39), which was significantly higher than that of master graduates 96.67 (±22.81), and the degree of liking for nursing work also reached a Significant difference. These two variables are important predictors of job adaptation needs, and the R Square is 24.15%. Conclusion: Increasing the love of clinical nurses in nursing and encouraging university graduation to have positive effects on job pressure adaptation needs and can be used as a reference for the management of human resources hospitals for oncology nurses.

Keywords: oncology nurse, job stress, job stress adaptation needs, manpower

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Authors: Derya Yucel, Nigar Angın, Dürdane Mart, Meltem Turkeri, Volkan Catalkaya, Celal Yucel

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Chickpea (Cicer arietinum L.) with high protein content is a vital food, especially in under-developed and developing countries for the people who do not consume enough meat due to low-income level. The objective of the proposed study is to evaluate growing, yield and yield components of chickpea genotypes under Mediterranean condition so determine tolerance of chickpea genotypes against drought and heat stress. For this purpose, a total of 34 chickpea genotypes were used as material. The experiment was conducted according to factorial randomized complete block design with 3 reps at the Eastern Mediterranean Research Institute, Adana, TURKEY for 2014-15 growing season under three different growing conditions (Winter sowing, irrigated-late sowing and non-irrigated- late sowing). According to results of this experiment, vegetative period, flowering time, poding time, maturity time, plant height, height of first pod, seed yield and 100 seed weight were ranged between 68.33 to 78.77 days, 94.22 to 85.00 days, 94.11 to 106.44 days, 198.56 to 214.44 days, 37.18 to 64.89 cm, 18.33 to 34.83 cm, 417.1 to 1746.4 kg/ha and 14.02 to 45.02 g, respectively. Among the chickpea genotypes, the Aksu, Arda, Çakır, F4 09 (X 05 TH 21-16189), FLIP 03-108 were least affected by drought and heat stress. Therefore, these genotypes can be used as sources of drought and heat tolerance in further breeding programme for evolving the drought and heat tolerant genotypes in chickpea.

Keywords: chickpea, drought stress, heat stress, yield

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Authors: Mahmoud Tarek, Alaa Obeida, Mai Magdy, Khalid Hussein, Aly Shalaby

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Background: More doctors are complaining of burnout than before, Burnout is a state of physical and mental exhaustion caused by the doctor’s lifestyle, unfortunately, Medical errors are also more likely in those suffering from burnout and these may result in malpractice suits. Methodology: It is a retrospective audit of burnout response on all neonatologists over a 9 months period. We gathered data using burnout questionnaire, it was obtained from 23 physicians, the physicians divided into 5 categories according to the final score of the 28 questions in the questionnaire. Category 1 with score from 28-38 with almost no work stress, category 2 with score (38-50) who express a low amount of job related stress, category 3 with score (51-70) with moderate amount of stress, category 4 with score (71-90) those express a high amount of job stress and begun to burnout, category 5 with score (91 and above) who are under a dangerous amount of stress and advanced stage of burnout. Results: 33 neonatologists have received the questionnaire, 23 responses were sent back with a response rate of 69.6%. The results showed that 61% of physicians fall in category 4, 31% of the physician in category 5, while 8% of physicians equally distributed between category 2 and 3 (4% each of them). On the other hand, there is no physician present in category 1. Conclusion: Burnout is prevalent in SNICUs, So interventions to minimize burnout prevalence may be of greater importance as this may be reflected indirectly on medical conditions of the patients and physicians, efforts should be done to decrease this high rate of burnout.

Keywords: Cairo, work overload, exhaustion, surgery, neonatal ICU

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Authors: Kurniawan Adha, Wan Ismail Wan Yusoff, Luluan Almanna Lubis

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Preventing hazardous events during oil and gas operation is an important contribution of accurate pore pressure data. The availability of pore pressure data also contribute in reducing the operation cost. Suggested methods in pore pressure estimation were mostly complex by the many assumptions and hypothesis used. Basic properties which may have significant impact on estimation model are somehow being neglected. To date, most of pore pressure determinations are estimated by data model analysis and rarely include laboratory analysis, stratigraphy study or core check measurement. Basically, this study developed a model that might be applied to investigate the changes of pore pressure and effective stress due to hydrocarbon production. In general, this paper focused velocity model effect of pore pressure and effective stress changes due to hydrocarbon production with illustrated by changes in saturation. The core samples from Miri field from Sarawak Malaysia ware used in this study, where the formation consists of sandstone reservoir. The study area is divided into sixteen (16) layers and encompassed six facies (A-F) from the outcrop that is used for stratigraphy sequence model. The experimental work was firstly involving data collection through field study and developing stratigraphy sequence model based on outcrop study. Porosity and permeability measurements were then performed after samples were cut into 1.5 inch diameter core samples. Next, velocity was analyzed using SONIC OYO and AutoLab 500. Three (3) scenarios of saturation were also conducted to exhibit the production history of the samples used. Results from this study show the alterations of velocity for different saturation with different actions of effective stress and pore pressure. It was observed that sample with water saturation has the highest velocity while dry sample has the lowest value. In comparison with oil to samples with oil saturation, water saturated sample still leads with the highest value since water has higher fluid density than oil. Furthermore, water saturated sample exhibits velocity derived parameters, such as poisson’s ratio and P-wave velocity over S-wave velocity (Vp/Vs) The result shows that pore pressure value ware reduced due to the decreasing of fluid content. The decreasing of pore pressure result may soften the elastic mineral frame and have tendency to possess high velocity. The alteration of pore pressure by the changes in fluid content or saturation resulted in alteration of velocity value that has proportionate trend with the effective stress.

Keywords: pore pressure, effective stress, production, miri formation

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Authors: Alexandru Dumitrache, Florin Frunzulica, Octavian Preotu

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The flow mitigation detachment problem near solid surfaces, resulting in improved globally aerodynamic performance by exploiting the Coanda effect on surfaces, has been addressed extensively in the literature, since 1940. The research is carried on and further developed, using modern means of calculation and new experimental methods. In this paper, it is shown interest in the detailed behavior of a classical interior ejector assisted by the Coanda effect, used in propulsion systems. For numerical investigations, an implicit formulation of RANS equations for axisymmetric flow with a shear stress transport k- ω (SST model) turbulence model is used. The obtained numerical results emphasize the efficiency of the ejector, depending on the physical parameters of the flow and the geometric configuration. Furthermore, numerical investigations are carried out regarding the evolution of the Reynolds number when the jet is attached to the wall, considering three geometric configurations: sudden expansion, open cavity and sudden expansion with divergent at the inlet. Therefore, further insight into complexities involving issues such as the variety of flow structure and the related bifurcation and flow instabilities are provided. Thus, the conditions and the limits within which one can benefit from the advantages of Coanda-type flows are determined.

Keywords: Coanda effect, Coanda ejector, CFD, stationary bifurcation, sudden expansion

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Authors: Lalit Kishore, Randhir Singh

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Diabetic nephropathy (DN) is the major cause of morbidity among diabetic patients. In this study, the effect of Bacopa monnieri Linn. (Brahmi, BM), was studied in a Streptozotocin (STZ)-induced experimental rat model of DN. Diabetic nephropathy was induced in Male Wistar rats (body weight- 300± 10 gms) by single intra-peritoneal injection of STZ (45mg/kg, i.p.) after 15 min of Nicotinamide (230 mg/kg) administration. Different doses of alcoholic extract i.e. 100, 200 and 400 mg/kg was given for 45 days by oral gavage after induction of DN. Blood glucose level, serum insulin, glycosylated haemoglobin, renal parameters (serum urea, uric acid, creatinine and BUN) and lipid profile (total cholesterol, triglycerides, HDL, LDL and VLDL levels) were measured. Concentration of thiobarbituric acid reactive species (TBARS) and levels of antioxidant enzymes of reduced glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) were evaluated in the kidney, liver and pancreas. At the end of treatment period the alcoholic extract of BM reduced the elevated level of blood glucose, serum insulin, renal parameters, lipid levels, TBARS, AGE’s in kidney and significantly increased body weight, HDL and antioxidant enzymes in dose dependent manner as compared to diabetic control animals. These results suggested the BM possesses significant renoprotective activity.

Keywords: AGE's, lipid profile, oxidative stress, renal parameters

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Authors: Sanxiong Fu, Yanyan Lv, Song Chen, Wei Zhang, Cunkou Qi

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Ethylene response factor proteins are known to play an important role in regulating a variety of stress responses in plants, but their exact functions in submergence stress are not completely understood. In this study, we isolated BnERF from Brassica napus L. to study the function of BnERF in submergence tolerance. The expression of BnERF gene in Brassica napus L. and the expression of antioxidant enzyme genes in transgenic Arabidopsis were analyzed by Quantitative RT-PCR. It was found that expression of BnERF is apparently induced by submergence in Brassica napus L. and overexpression of BnERF in Arabidopsis increases the tolerance level to submergence and oxidative stress. Histochemical method detected lower level of H2O2, O2•− and malondialdehyde (MDA) in the transgenic Arabidopsis. Compared to wild type, transgenic lines also have higher soluble sugar content and higher activity of antioxidant enzymes, which helps protect the plants against the oxidative damage caused by submergence. It was concluded that BnERF can increase the tolerance of plants to submergence stress and BnERF might be involved in regulating soluble sugar content and the antioxidant system in the defense against submergence stress.

Keywords: antioxidant enzyme, Arabidopsis, ethylene response factor, submergence

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Authors: Sanjin Kršćanski, Josip Brnić

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Virtual Crack Closure Technique (VCCT) is a method used for calculating stress intensity factor (SIF) of a cracked body that is easily implemented on top of basic finite element (FE) codes and as such can be applied on the various component geometries. It is a relatively simple method that does not require any special finite elements to be used and is usually used for calculating stress intensity factors at the crack tip for components made of brittle materials. This paper studies applicability and accuracy of VCCT applied on standard metal specimens containing trough thickness crack, subjected to an in-plane bending load. Finite element analyses were performed using regular 4-node, regular 8-node and a modified quarter-point 8-node 2D elements. Stress intensity factor was calculated from the FE model results for a given crack length, using data available from FE analysis and a custom programmed algorithm based on virtual crack closure technique. Influence of the finite element size on the accuracy of calculated SIF was also studied. The final part of this paper includes a comparison of calculated stress intensity factors with results obtained from analytical expressions found in available literature and in ASTM standard. Results calculated by this algorithm based on VCCT were found to be in good correlation with results obtained with mentioned analytical expressions.

Keywords: VCCT, stress intensity factor, finite element analysis, 2D finite elements, bending

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Authors: Muhammad Naweed, Usman Tariq Murtaza, Waseem Siddique

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A pallet body approach is a finite element-based computational approach used for the modeling and assessment of a three-dimensional surface crack. The approach is capable of inserting the crack in an engineering structure and generating high-quality hexahedral mesh in the cracked region of the structure. The approach is capable of computing the stress intensity factors along a semi-elliptical surface crack numerically. The objective of this work is to present that the stress intensity factors produced by the approach can be used with confidence for capturing the parameters during the fatigue crack growth.

Keywords: pallet body approach, semi-elliptical surface crack, stress intensity factors, fatigue crack growth

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Authors: Eun Gyeong Lee, Ji Young Park, Hyun Ae Woo

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Reactive oxygen species (ROS) production is involved in ischemia/reperfusion (I/R) injury in kidney of mice. Oxidative stress develops from an imbalance between ROS production and reduced antioxidant defenses. Many enzymatic and nonenzymatic antioxidant systems including peroxiredoxins (Prxs) are present in kidney to maintain an appropriate level of ROS and prevent oxidative damage. Prxs are a family of peroxidases that reduce peroxides, with a conserved cysteine residue serving as the site of oxidation by peroxides. In this study, we examined the protective role of Prx V against I/R-induced acute kidney injury (AKI) using Prx V wild type (WT) and knockout (KO) mice. We compared the response of Prx V WT and KO mice in mice model of I/R injury. Renal structure, functions, oxidative stress markers, protein levels of oxidative damage marker were worse in Prx V KO mice. Ablation of Prx V enhanced susceptibility to I/R-induced oxidative stress. Prx V KO mice were seen to have more severe renal damage than Prx V WT mice in mice model of I/R injury. Our results demonstrate that Prx V is protective against I/R-induced AKI.

Keywords: peroxiredoxin, ischemia/reperfusion, kidney, oxidative stress

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Authors: Alok Pal Jain, Santram Lodhi

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Martynia annua Linn. (Martyniaccae) is traditionally used in inflammation and applied locally to tuberculosis glands of camel’s neck. The leaves used topically to bites of venomous insects and wounds of domestic animals. Chemical examination of Martynia annua leaves revealed the presence of glycosides, tannins, proteins, phenols and flavonoids. The present study was aimed to evaluate the anti-arthritic activity of methanolic extract of Martynia annua leaves. Methanolic extract of Martynia annua leaves was tested by using in vivo collagen-induced arthritis mouse model to investigate the anti-rheumatoid arthritis activity. In addition, antioxidant effect of methanolic extract was determined by the estimation of antioxidants level in joint tissues. The severity of arthritis was assessed by arthritis score and edema. Levels of cytokines TNF-α and IL-6, in the joint tissue homogenate were measured using ELISA. A high dose (250 mg/kg) of methanolic extract was significantly reduced the degree of inflammation in mice as compared with reference drug. Antioxidants level and malondialdehyde (MDA) in joint tissue homogenate found significantly (p < 0.05) higher. Methanolic extract at dose of 250 mg/kg modulated the cytokines production and suppressed the oxidative stress in the mice with collagen-induced arthritis. This study suggested that Martynia annua might be alternative herbal medicine for the management of rheumatoid arthritis.

Keywords: Martynia annua, collagen, rheumatoid arthritis, antioxidants

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Authors: Jiun-Nan Hou, Tien-Huang Chen, Wei-June Chen

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Dengue viruses (DENVs) are naturally transmitted between humans by mosquito vectors. Mosquito cells usually survive DENV infection, allowing infected mosquitoes to retain an active status for virus transmission. In this study, we found that DENV2 virus infection in mosquito cells causes the unfolded protein response (UPR) that activates the protein kinase RNA-like endoplasmic reticulum kinase (PERK) signal pathway, leading to shutdown of global protein translation in infected cells which was apparently regulated by the PERK signal pathway. According to observation in this study, the PERK signal pathway in DENV2-infected C6/36 cells alleviates ER stress, and reduces initiator and effector caspases, as well as the apoptosis rate via shutdown of cellular proteins. In fact, phosphorylation of eukaryotic initiation factor 2ɑ (eIF2ɑ) by the PERK signal pathway may impair recruitment of ribosomes that bind to the mRNA 5’-cap structure, resulting in an inhibitory effect on canonical cap-dependent cellular protein translation. The resultant pro-survival “byproduct” of infected mosquito cells is undoubtedly advantageous for viral replication. This finding provides insights into elucidating the PERK-mediated modulating web that is actively involved in dynamic protein synthesis, cell survival, and viral replication in mosquito cells.

Keywords: cap-dependent protein translation, dengue virus, endoplasmic reticulum stress, mosquito cells, PERK signal pathway

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Authors: Shiva Rezaei, Seyed Jalal Hosseinimehr, Abbasali Karimpour Malekshah, Mansooreh Mirzaei, Fereshteh Talebpour Amiri, Mehryar Zargari

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Objective(s): Cyclophosphamide (CP), as an antineoplastic drug, is widely used in cancer patients, and liver toxicity is one of its complications. Sinapic acid (SA), as a natural phenylpropanoid, has antioxidant, anti-inflammatory, and anti-cancer properties. Materials and Methods: The purpose of the current study was to determine the protective effect of SA versus CP-induced liver toxicity. In this research, BALB/c mice were treated with SA (5 and 10 mg/kg) orally for one week, and CP (200 mg/kg) was injected on day 3 of the study. Oxidative stress markers, serum liver-specific enzymes, histopathological features, caspase-3, and nuclear factor kappa-B cells were then checked. Results: CP induced hepatotoxicity in mice and showed structural changes in liver tissue. CP significantly increased liver enzymes and lipid peroxidation and decreased glutathione. The immunoreactivity of caspase-3 and nuclear factor kappa-B cells was significantly increased. Administration of SA significantly maintained histochemical parameters and liver function enzymes in mice treated with CP. Immunohistochemical examination showed SA reduced apoptosis and inflammation. Conclusion: The data confirmed that SA with anti-apoptotic, anti-oxidative, and anti-inflammatory activities was able to preserve CP-induced liver injury in mice.

Keywords: apoptosis, cyclophosphamide, liver injury, inflammation, oxidative stress, sinapic acid

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Authors: Mihai Palade, Gina Cecilia Pistol, Mariana Stancu, Veronica Chedea, Ionelia Taranu

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Nutrition is an important determinant of general health status, with especially focus on prevention and/or attenuation of the inflammatory-associated pathologies. People with chronic kidney disease can experience chronic inflammation that can lead to cardiovascular disease and even an increased rate of death. There are important links between chronic kidney diseases, inflammation and nutritional strategies that may prevent or protect against undesirable inflammation and oxidative stress. The grape by-products either seeds or pomace are rich in polyphenols which may be beneficial in prevention of inflammatory, antioxidant and antimicrobial processes. As a model for studying the impact of grape seeds on renal inflammation and oxidative stress, we used in this study weaned piglets. After a feeding trial of 30 days with a control diet and an experimental diet containing 5% grape seed (GS), kidney samples were collected. In renal tissues were determined the expression and activity of important markers of immune respose and oxidative stress: pro-inflammatory cytokines (TNF-alpha, IL-1 beta, IL-6, IL-8, IFN-gamma), anti-inflammatory cytokines (IL-4, IL-10), anti-oxidant enzymes (catalase CAT, superoxide dismutase SOD, glutathione peroxidise GPx) and important mediators belonging to nuclear receptors (NF-kB1, Nrf-2 and PPAR-gamma). Gene expression was evaluated by qPCR, whereas protein concentration was determined using proteomic techniques (ELISA). The activity of anti-oxidant enzymes was determined using specific kits. Our results showed that GS enriched in polyphenols does not have effect on TNF-alpha, IL-6 and IL-1 beta gene expression and protein concentration in kidney. By contrast, the gene expression and protein level of IL-8 and IFN-gamma were decreased in GS kidney. Anti-inflammatory cytokines IL-4 and IL-10 gene levels were increased in kidneys collected from GS piglets in comparison with controls, with no modification of protein levels between the two groups. The activities of anti-oxidant enzymes CAT and GPx were increased in kidney by GS, whereas SOD activity was unmodified in comparison with control samples. Also, the GS diet was associated with no modulation of mRNAs for nuclear receptors NF-kB1, Nrf-2 and PPAR-gamma gene expressions in kidneys. In conclusion, our results demonstrated that GS enriched in bioactive compounds such polyphenols could modulate inflammation and oxidative stress markers in kidney tissues. Further studies are necessary to elucidate the mechanism of action of GS compounds in case kidney inflammation associated with oxidative stress, and signalling molecules involved in these mechanisms.

Keywords: animal model, kidney inflammation, oxidative stress, grape seed

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Authors: Hyeon-Kyo Lim, Tong-Il Jang, Yong-Hee Lee

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Human error is one of the most dreaded factors that may result in unexpected accidents, especially in nuclear power plants. For accident prevention, it is quite indispensable to analyze and to manage the influence of any factor which may raise the possibility of human errors. Out of lots factors, stress has been reported to have a significant influence on human performance. Therefore, this research aimed to develop a work-related stress management program which can guarantee Fitness-for-Duty (FFD) of the workers in nuclear power plants, especially those working in main control rooms. Major stress factors were elicited through literal surveys and classified into major categories such as demands, supports, and relationships. To manage those factors, a test and intervention program based on 4-level approaches was developed over the whole employment cycle including selection and screening of workers, job allocation, and job rotation. In addition, a managerial care program was introduced with the concept of Employee-Assistance-Program (EAP) program. Reviews on the program conducted by ex-operators in nuclear power plants showed responses in the affirmative, and suggested additional treatment to guarantee high performance of human workers, not in normal operations but also in emergency situations.

Keywords: human error, work performance, work stress, Fitness-For-Duty (FFD), Employee Assistance Program (EAP)

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Authors: Poonam Yadav, Dong Bok Lee

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In this study, the Ti-6Al-4V alloy was isothermally and cyclically oxidized at 800oC for 40 hours in air, and its oxidation behavior was characterized in terms of its oxidation rate, scaling rate, and scale spallation tendency. The isothermal oxidation tests indicated that Ti-6Al-4V oxidized fast and almost linearly, forming thick oxide scales. However, the scales that formed during isothermal oxidation were adherent. The cyclic oxidation tests indicated that the scales that formed on Ti-6Al-4V were highly susceptible to spallation owing to the large growth stress arisen and the thermal stress imposed during thermal cyclings. The formed scales frequently delaminated into several pieces owing to the excessive stress aroused by the repetitive thermal shock. Particularly, excessive oxidation and heavy spallation occurred at the edge of Ti-6Al-4V during cyclic oxidation.

Keywords: cyclic, isothermal, oxidation, spallation

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Authors: C. H. Shashikanth, M. J. Davidson, V. Suresh Babu

Abstract:

The formability of metals depends on a number of variables such as strain, strain rate, and temperature. Though most of the metals are formable at room temperature, few are not. To evaluate the workability of such metals at elevated temperatures, thermomechanical experiments should be carried out to find out the forming temperatures and strain rates. Though a number of constitutive relations are available to correlate the material parameters and the corresponding formability at elevated temperatures, the constitutive rule proposed by Arrhenius has been used in this work. Thus, in the present work, the material constants such as A (constant), α (stress multiplier), β (constant), and n (stress exponent) of AA 2017 has been found by conducting a series of hot compression tests at different temperatures such as 400°C, 450°C, 500°C, and 550°C and at different strain rates such as 0.16, 0.18, and 0.2. True stress (σt), true strains (εt) deformation activation energy (Q), and the Zener-Hollomon parameter (Z value) were also calculated. The results indicate that the value of ln (Z) decreases as the temperature increases and it increases as the strain rate increases.

Keywords: hot compression test, aluminium alloy, flow stress, activation energy

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Authors: Hooman Rowshanaie

Abstract:

The majority of green plants have 70%-90% water, this amount depend on age of plants, species, tissues of plants and also the environmental conditions that plants growth and development on it. Because of intense plant demanding to achieve the available water for growing and developing, always plants need a water sources and also mechanisms to retention the water and reduction water loss under critical situation and water deficit conditions otherwise the yield of plants would be decreased. Decreasing the yield depend on genotypes, intense of water deficit and also growth stage. Recently the mechanisms and also compound that have major role to water stress adaption of plants would be consideration. Osmotic adjustment is one of the most important mechanisms in terms of this field that many valuable researches focused on it because the majority of organic and inorganic solutes directly or even indirectly have pivotal role in this phenomenon. The contribution of OA to prevent water loss in response to water deficit and resistance to water stress taken to consideration recently and also the organic and inorganic compounds to OA tended has a high rate of significant.

Keywords: water deficit, drought stress, osmotic adjustment, organic compound, inorganic compound, solute

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Authors: Rawa Delshada, Sanaa G. Hamab, Rastee D. Koyeec

Abstract:

Eighty patients with suspected ischemic heart disease were enrolled in the present study. They were classified into two groups: patients with positive exercise stress test results (n=40) and control group with negative exercise stress test results (n=40). Serum concentration of troponin I, Heart-type Fatty Acid Binding Protein (H-FABP) and Ischemia Modified Albumin (IMA) were measured one hour after performing stress test. Enzyme Linked Immunosorbent Assay was used to measure both troponin I, H-FABP levels, while IMA levels were measured by albumin cobalt binding test. There was no statistically significant difference in the mean concentration of troponin I between two groups (0.75±0.55ng/ml) for patients with positive test result vs. (0.71±0.55ng/ml) for negative test result group with P>0.05. Contrary to our expectation, mean IMA level was slightly higher among control group (70.88±39.76U/ml) compared to (62.7±51.9U/ml) in positive test result group, but still with no statistically significant difference (P>0.05). Median H-FABP level was also higher among negative exercise stress testing group compared the positive one (2ng/ml vs. 1.9ng/ml respectively), but failed to reach statistically significant difference (P>0.05). When quartiles model used to explore the possible association between each study biomarkers with the others; serum H-FABP level was lowest (1.7ng/ml) in highest quartile of IMA and lowest H-FABP (1.8ng/ml) in highest quartile of troponin I but with no statistically significant association (P>0.05). Myocardial ischemia, more likely occurred after exercise stress test, is not capable of causing troponin I release. Furthermore, an increase in H-FABP and IMA levels after stress test are not reflecting myocardial ischemia. Moreover, the combination of troponin I, H-FABP and IMA after measuring their post exercise levels does not improve the diagnostic utility of exercise stress test enormously.

Keywords: cardiac biomarkers, ischemic heart disease, troponin I, ischemia modified albumin, heart-type fatty acid binding protein, exercise stress testing

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Authors: Maurizio E. Picarella, Ludovica Fumelli, Francesca Siligato, Andrea Mazzucato

Abstract:

Studies on reproductive dynamics in crops subjected to heat stress are crucial to breed more tolerant cultivars. In tomato, cultivars, breeding lines, and wild species have been thoroughly evaluated for the response to heat stress in several studies. Here, we address the reaction to temperature stress in a panel of selected landraces representing genotypes cultivated before the advent of professional varieties that usually show high adaptation to local environments. We adopted an experimental design with two open field trials, where transplanting was spaced by one month. In the second field, plants were thus subjected to mild stress with natural temperature fluctuations. The genotypes showed wide variation for both vegetative (plant height) and reproductive (stigma exsertion, pollen viability, number of flowers per inflorescence, and fruit set) traits. On average, all traits were affected by heat conditions; except for the number of flowers per inflorescence, the “G*E” interaction was always significant. In agreement with studies based on different materials, estimated broad sense heritability was high for plant height, stigma exsertion, and pollen viability and low for the number of flowers per inflorescence and fruit set. Despite the interaction, traits recorded in control and in heat conditions were positively correlated. The first two principal components estimated by multivariate analysis explained more than 50% of the total variability. The study indicated that landraces present a wide variability for the response of reproductive traits to temperature stress and that such variability could be very informative to dissect the traits with higher heritability and identify new QTL useful for breeding more resilient varieties.

Keywords: fruit set, heat stress, solanum lycopersicum L., style exsertion, tomato

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Authors: Brian Kristopher Cambra

Abstract:

Millions of displaced families are seeking refuge in countries that are not their own due to war, violence, persecution, political unrest, and natural disasters. This global crisis is forcing researchers and practitioners to consider how refugees are coping with the trauma associated with their migration process. Effective therapeutic approaches are needed in a global effort to address the traumatic impact of forced migration. This meta-analytical study investigates the effectiveness of expressive therapeutic modalities, including play, art, music, sandplay, theatre, and writing therapies, in helping children and adolescents cope with refugee trauma. Seventeen pre-post and between-group comparison studies were analyzed using a random-effects model. The combined effect size for pre-post comparisons was medium (g = 0.58), whereas the combined effect size for between-group comparisons was small (g = 0.32). Overall, art therapy was found to be most effective in treating stress symptoms. Heterogeneity tests, however, suggest effect sizes cannot be interpreted as meaningful due to substantial variance. Nevertheless, findings of this meta-analysis indicate that expressive therapies may be among beneficial modalities to integrate with other trauma-informed approaches.

Keywords: expressive therapies, forced migration, meta-analysis, refugees, trauma

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Authors: Nadine Ali Hassan, Ngoc Son Nguyen, Didier Marot, Fateh Bendahmane

Abstract:

This paper aims at presenting a study of the effect of scalping methods on the mechanical properties of coarse soils by resorting to numerical simulations based on the discrete element method (DEM) and experimental triaxial tests. Two reconstitution methods are used, designated as scalping method and substitution method. Triaxial compression tests are first simulated on a granular materials with a grap graded particle size distribution by using the DEM. We study the effect of these reconstitution methods on the stress-strain behavior of coarse soils with different fine contents and with different ways to control the densities of the scalped and substituted materials. Experimental triaxial tests are performed on original mixtures of sands and gravels with different fine contents and on their corresponding scalped and substituted samples. Numerical results are qualitatively compared to experimental ones. Agreements and discrepancies between these results are also discussed.

Keywords: coarse soils, mechanical behavior, scalping, replacement, triaxial devices

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Authors: Zhaofeng Li, Jun Kang Chow, Yu-Hsing Wang

Abstract:

This paper attempts to bridge the soil properties and the mechanical response of soil in the discrete element method (DEM) simulation. The artificial neural network (ANN) was therefore adopted, aiming to reproduce the stress-strain-volumetric response when soil properties are given. 31 biaxial shearing tests with varying soil parameters (e.g., initial void ratio and interparticle friction coefficient) were generated using the DEM simulations. Based on these 45 sets of training data, a three-layer neural network was established which can output the entire stress-strain-volumetric curve during the shearing process from the input soil parameters. Beyond the training data, 2 additional sets of data were generated to examine the validity of the network, and the stress-strain-volumetric curves for both cases were well reproduced using this network. Overall, the ANN was found promising in predicting the soil behavior and reducing repetitive simulation work.

Keywords: artificial neural network, discrete element method, soil properties, stress-strain-volumetric response

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Authors: A. Fogliata, L. Martiniello, A. Ambretti

Abstract:

Introduction: The significance of balance and stability in physical education among adolescents is well-established. This study aims to assess the efficacy of Centering (CENT), which employs intra-abdominal pressure (IAP) in line with the Synchrony Method, in optimizing balance and reducing perceived stress. Materials and Methods: A 6-week intervention was conducted on a sample of adolescents, divided into a control group and an experimental group that incorporated CENT into their physical education program. The Stork Balance Test and the Perceived Stress Scale (PSS) were used to measure changes. Results: Findings revealed a significant enhancement in the balance of both the dominant and non-dominant limbs in the experimental group compared to the control group. Moreover, the PSS test indicated a reduction in perceived stress within the experimental group. Conclusion: Integrating the centering technique into physical education programs can lead to substantial improvements in adolescents' balance and stability, in addition to a reduction in perceived stress levels. These findings suggest the need for further research on broader populations to solidify these pivotal outcomes.

Keywords: adolescents, physical education, balance, centering, intra-abdominal pressure

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