Corrosion degradation is detrimental to metal structures as it shortens their lifetime and leads to huge economic losses and unexpected disasters.Therefore,the detection and monitoring of corrosion degradation is of g...Corrosion degradation is detrimental to metal structures as it shortens their lifetime and leads to huge economic losses and unexpected disasters.Therefore,the detection and monitoring of corrosion degradation is of great importance.Herein,we briefly review the state-of-the-art electrochemical methods,instrumentation(based on virtual instrumentation),and advanced sensor/probes that are used in the field for the assessment of corrosion damage.Typical corrosion monitoring results,some of which have been obtained at Tianjin University in the past 30 years,for metallic materials and organic coating/metal systems in atmospheric,marine,and soil conditions in the field are presented.Detection methods,data analysis,and theoretical and mathematical models regarding each corrosion system are discussed,and the challenges,problems and possible solutions for each case are suggested.Lastly,future developments,such as wireless,intelligent,and automatic electrochemical measurement,that will augment the present electrochemical methods of evaluating corrosion degradation are summarized.展开更多
In this study, a new mathematical model is developed composed of two parts, including harmonic and polynomial expressions for simulating the dominant velocity pulse of near fault ground motions. Based on a proposed ve...In this study, a new mathematical model is developed composed of two parts, including harmonic and polynomial expressions for simulating the dominant velocity pulse of near fault ground motions. Based on a proposed velocity function, the corresponding expressions for the ground acceleration and displacement time histories are also derived. The proposed model is then fitted using some selected pulse-like near fault ground motions in the Next Generation Attenuation （NGA） project library. The new model is not only simple in form but also simulates the long-period portion of actual velocity near fault records with a high level of precision. It is shown that the proposed model-based elastic response spectra are compatible with the near fault records in the neighborhood of the prevailing frequency of the pulse. The results indicate that the proposed model adequately simulates the components of the time histories. Finally, the energy of the proposed pulse was compared with the energy of the actual record to confirm the compatibility.展开更多
The K-means algorithm is one of the most popular techniques in clustering. Nevertheless, the performance of the Kmeans algorithm depends highly on initial cluster centers and converges to local minima. This paper prop...The K-means algorithm is one of the most popular techniques in clustering. Nevertheless, the performance of the Kmeans algorithm depends highly on initial cluster centers and converges to local minima. This paper proposes a hybrid evolutionary programming based clustering algorithm, called PSO-SA, by combining particle swarm optimization (PSO) and simulated annealing (SA). The basic idea is to search around the global solution by SA and to increase the information exchange among particles using a mutation operator to escape local optima. Three datasets, Iris, Wisconsin Breast Cancer, and Ripley's Glass, have been considered to show the effectiveness of the proposed clustering algorithm in providing optimal clusters. The simulation results show that the PSO-SA clustering algorithm not only has a better response but also converges more quickly than the K-means, PSO, and SA algorithms.展开更多
One goal in the face of drought stress conditions is to increase growth and yield through the reduction of negative effects of stress. Vermicompost can play an effective role in plant growth and development and in red...One goal in the face of drought stress conditions is to increase growth and yield through the reduction of negative effects of stress. Vermicompost can play an effective role in plant growth and development and in reducing harmful effects of various environmental stresses on plants due to its porous structure, high water storage capacity, having hormone-like substances, plant growth regulators, and high levels of macro and micro nutrients. This study considered the physiological, biochemical, and photosynthetic responses of the chickpea to different combinations of vermicompost and water stress in a greenhouse environment. Two factors were involved, addition of vermicompost to soil at four ratios： control （100 wt% （weight percentage） sol0; 10 wt% vermicompost＋90% soil; 20 wt% vermicompost＋80 wt% soil; 30 wt% vermicompost＋70 wt% soil weight percentage, and treatment of water stress at three levels including 75, 50, and 25% of field capacity. The results showed that vermicompost had a significant effect on all traits under stress and non-stress conditions. Application of vermicompost in soil, especially at the levels of 20 and 30 wt% significantly increased all studied traits under non-stress conditions. Under moderate stress conditions, vermicompost at 30 wt% treatment resulted in a significant increase in the photosynthetic pigments, CO2 assimilation rate, internal leaf CO2 concentration, transpiration, the maximal quantum yield of photosystem II （PSII） photochemistry （FJF）, concentrations of Ca and K in root and leaf tissues, proline and soluble protein contents in root tissues. Peroxidase （POX） and catalase （CAT） enzyme activities decreased significantly with increasing proportions of vermicompost, but the activity of superoxide dismutase was not significantly different. In conclusion, the above results showed that vermicompost fertilizer had a positive effect on physiological, biochemical, and photosynthetic responses of chickpea under non-stress and moderate stress conditions, bu展开更多
In this work we synthesize a novel and highly efficient photocatalyst for degradation of methyl orange and rhodamine B. In addition, a new method for synthesis of FeO@SiO@TiO@Ho magnetic core-shell nanoparticles with ...In this work we synthesize a novel and highly efficient photocatalyst for degradation of methyl orange and rhodamine B. In addition, a new method for synthesis of FeO@SiO@TiO@Ho magnetic core-shell nanoparticles with spherical morphology is proposed. The crystal structures, morphology and chemical properties of the as-synthesized nanoparticles were characterized using Fourier transform infrared spectroscopy（FT-IR）, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, energy dispersive X-ray（EDS）, X-ray diffraction（XRD）, UV–vis diffuse reflectance spectroscopy（DRS） and vibrating sample magnetometer（VSM） techniques. The photocatalytic activity of FeO@SiO@TiO@Ho was investigated by degradation of methyl orange（MO） as cationic dye and rhodamine B（Rh B） as anionic dye in aqueous solution under UV/vis irradiation. The results indicate that about 92.1% of Rh B and78.4% of MO were degraded after 120 and 150 min, respectively. These degradation results show that FeO@SiO@TiO@Ho nanoparticles are better photocatalyst than Fe3O4@Si O2@TiO 2@Ho for degradation of MO and Rh B. As well as, the catalyst shows high recovery and stability even after several separation cycles.展开更多
AIM: To investigate the accuracy of T2*-weighted magnetic resonance imaging (MRI T2*) in the evaluation of iron overload in beta-thalassemia major patients. METHODS: In this cross-sectional study, 210 patients with be...AIM: To investigate the accuracy of T2*-weighted magnetic resonance imaging (MRI T2*) in the evaluation of iron overload in beta-thalassemia major patients. METHODS: In this cross-sectional study, 210 patients with beta-thalassemia major having regular blood transfusions were consecutively enrolled. Serum ferritin levels were measured, and all patients underwent MRI T2* of the liver. Liver biopsy was performed in 53 patients at an interval of no longer than 3 mo after the MRIT2* in each patient. The amount of iron was assessed in both MRI T2* and liver biopsy specimens of each patient. RESULTS: Patients’ ages ranged from 8 to 54 years with a mean of 24.59 ± 8.5 years. Mean serum ferritin level was 1906 ± 1644 ng/mL. Liver biopsy showed a moderate negative correlation with liver MRI T2* (r = -0.573, P = 0.000) and a low positive correlation with ferritin level (r = 0.350, P = 0.001). Serum ferritin levels showed a moderate negative correlation with liver MRI T2* values (r = -0.586, P = 0.000). CONCLUSION: Our study suggests that MRI T2* is a non-invasive, safe and reliable method for detecting iron load in patients with iron overload.展开更多
Objective:To investigate the epidemiological situation of animal bites in Rostam city of Fars province.Methods:This is a cross-sectional study.Cases of animal bites registered in health centers of Rostam city of Fars ...Objective:To investigate the epidemiological situation of animal bites in Rostam city of Fars province.Methods:This is a cross-sectional study.Cases of animal bites registered in health centers of Rostam city of Fars province from the beginning of 2014 to 2020 were analyzed using the census method.The tool for collecting information was the portal of the Ministry of Health and the registration offices of people who were referred to the rabies center.Results:A total of 628 cases of animal bites registered in health centers of Rostam city of Fars province from the beginning of 2014 to 2020.The mean age of the injured was(31.3±20.2)years.Of the total injured cases,414(65.9%)were male,and 491(78.2%)lived in villages.Most of the cases were bitten by dogs(n=420,66.8%)and the upper limb was involved in 280(55.2%)cases.In addition,an increasing trend was observed in the incidence of animal bites from 2015 to 2020.Conclusions:The incidence of animal bites in Rostam City is high,and most of the cases occur in rural areas.Considering the injuries caused by animal bites,the risk of rabies transmission,and the high costs of vaccination and serum therapy,it is necessary to hold control,educational,and vaccination programs.展开更多
Objective:To investigate the distribution pattern of animal bites in Mirjaveh,Iran from 2015 to 2020.Methods:The data on animal bites were collected from the Department of Infectious Diseases,the provincial health cen...Objective:To investigate the distribution pattern of animal bites in Mirjaveh,Iran from 2015 to 2020.Methods:The data on animal bites were collected from the Department of Infectious Diseases,the provincial health center.Monthly climatic data on precipitation and temperature during the study period were also collected.The correlation between incidence and temperature,precipitation rate,land type,and altitude was also analyzed.Results:The results showed that men were more affected by animal bites than women(76.4%,P<0.001),and the highest incidence rate occurred in the age group of 5-19 years.The incidence rate of animal bites was found to be correlated with temperature and altitude.An increase in temperature was associated with a rise in the incidence rate of animal bites.The number of animal bites increased until 2019,possibly due to an increase in the number of dogs in the area.Conclusions:Targeted interventions should be implemented to reduce the incidence of animal bites,particularly among children,housewives,and students.Improving access to appropriate treatments,increasing public awareness of the hazards of animal bites,and increasing the number of vaccinated dogs in the area are essential strategies to be considered.展开更多
Background Probiotic supplementation has been used to alleviate abdominal pain in children and adolescents with irritable bowel syndrome(IBS),but the evidence is not compelling.Thus,a systematic review and meta-analys...Background Probiotic supplementation has been used to alleviate abdominal pain in children and adolescents with irritable bowel syndrome(IBS),but the evidence is not compelling.Thus,a systematic review and meta-analysis of randomized clinical trials(RCTs)were performed to investigate the effects of probiotic supplementation on abdominal pain in pediatric patients with IBS.Methods PubMed/MEDLINE,Web of Science,Scopus,Cochrane Library,and Embase were the available databases searched to find relevant randomized clinical trials up to April 2021.The effect size was expressed as weighted mean differenee(WMD)and 95% confidence interval(CI).Results Seven RCTs with 441 participants were included,from which the meta-analysis demonstrated that probiotic supplementation has a significant effect on reducing abdominal pain in pediatric patients with IBS(WMD=-2.36:95%CI-4.12 to-0.60;P=0.009).Although our study involved children and adolescents(≤18 years),the effects of probiotic supplementation seem to be more potent in patients under 10 years old(WMD=-2.55;95%CI-2.84 to -2.27)compared to patients aged 10-18 years(WMD=-1.70;95%CI-2.18 to -1.22).The length of supplementation longer than four weeks was more effective(WMD=-2.43;95%CI-2.76 to -2.09).Conclusion Probiotic supplementation can reduce abdominal pain in pediatric patients with IBS.展开更多
In this paper, we present a comprehensive numerical simulation of a point wave absorber in deep water. Analyses are performed in both the frequency and time domains. The converter is a two-body floating-point absorber...In this paper, we present a comprehensive numerical simulation of a point wave absorber in deep water. Analyses are performed in both the frequency and time domains. The converter is a two-body floating-point absorber （FPA） with one degree of freedom in the heave direction. Its two parts are connected by a linear mass-spring-damper system. The commercial ANSYS-AQWA software used in this study performs well in considering validations. The velocity potential is obtained by assuming incompressible and irrotational flow. As such, we investigated the effects of wave characteristics on energy conversion and device efficiency, including wave height and wave period, as well as the device diameter, draft, geometry, and damping coefficient. To validate the model, we compared our numerical results with those from similar experiments. Our study results can clearly help to maximize the converter＇s efficiency when considering specific conditions.展开更多
We report the expression profile of acyl-lipid △12-desaturase （desA） gene from Synechocystis sp. PCC6803 and its effect on cell membrane lipid composition and cold tolerance in prokaryotic （Escherichia coil） and ...We report the expression profile of acyl-lipid △12-desaturase （desA） gene from Synechocystis sp. PCC6803 and its effect on cell membrane lipid composition and cold tolerance in prokaryotic （Escherichia coil） and eukaryotic （Solanum tuberosum） cells. For this purpose, a hybrid of desA and reporter gene encoding thermostable lichenase （licBM3） was constructed and used to transform these cells. The expression of this hybrid gene was measured using qualitative （Petri dish test, electrophoregram and zymogram） and quantitative methods （spectrometry and gas liquid chromatography assays）. The maximum level of linoleic acid in the bacterial cells containing hybrid gene was 1.9% of total fatty acids. Cold stress tolerance assays using plant damage index and growth parameters showed that cold tolerance was enhanced in primary transgenic lines because of increased unsaturated fatty acid concentration in their lipids. The greatest content of 18：2 and 18：3 fatty acids in primary transgenic plants was observed for lines 2 （73%） and 3 （41%）. Finally, our results showed that desaturase could enhance tolerance to cold stress in potato, and desaturase and lichenase retain their functionality in the structure of the hybrid protein where the enzymatic activity of target gene product was higher than in the case of reporter lichenase gene absence in the construction.展开更多
The present study is aimed to investigate the ability of different intensity measures （IMs）, including response spectral acceleration at the fundamental period of the structure, Sa（T1）, as a common scalar IM and t...The present study is aimed to investigate the ability of different intensity measures （IMs）, including response spectral acceleration at the fundamental period of the structure, Sa（T1）, as a common scalar IM and twelve vector-valued IMs for seismic collapse assessment of structures. The vector-valued IMs consist of two components, with S（T1） as the first component and different parameters that are ratios of scalar IMs, as well as the spectral shape proxies εSa and N, as the second component. After investigating the properties of an optimal IM, a new vector-valued IM that includes the ratio of Sa（T1） to the displacement spectrum intensity （DSI） as the second component is proposed. The new IM is more efficient than other IMs for predicting the collapse capacity of structures. It is also sufficient with respect to magnitude, source-to-site distance, and scale factor for collapse capacity prediction of structures. To satisfy the predictability criterion, a ground motion prediction equation （GMPE） is determined for Sa（T1）/DSI by using the existing GMPEs. Furthermore, an empirical equation is proposed for obtaining the correlation between the components of the proposed IM. The results of this study show that using the new vector-valued IM leads to a more reliable seismic collapse assessment of structures.展开更多
The influences of the dissimilarity in the roll speeds on the microstructure, texture and mechanical properties of 7075 aluminum plates produced via combined continuous casting and rolling(CCCR) process were investiga...The influences of the dissimilarity in the roll speeds on the microstructure, texture and mechanical properties of 7075 aluminum plates produced via combined continuous casting and rolling(CCCR) process were investigated. Several experiments were conducted with three different upper/lower roll rotational speed ratios(ω/ω0, ω is the upper roll rotational speed and ω0 is the lower roll rotational speed), namely 1:1, 1:1.2 and 1:1.4. It was found that the greatest dissimilarity in the roll speed(ω/ω0=1:1.4) improved the yield strength and ultimate tensile strength of 7075 Al plate in the rolling direction by 41.5% and 21.9%, respectively. Moreover, at a roll speed ratio of ω/ω0=1:1.4, the average grain size was decreased by 36% whereas the mean hardness of the transverse cross-section of the finally rolled plate was increased by about 9.2%. Texture studies also revealed that the more the difference in the roll speeds was, the greater the isotropy and the hardness of the final product were. Nevertheless, conducting CCCR operation with different roll speeds resulted in about 6% reduction in the elongation of the deformed plate.展开更多
A solar drum dryer was designed and constructed for paddy drying,including a fixed outer drum and inner perforated drum,which rotated at the desired rotational speed inside the outer drum.The maximum capacity of the d...A solar drum dryer was designed and constructed for paddy drying,including a fixed outer drum and inner perforated drum,which rotated at the desired rotational speed inside the outer drum.The maximum capacity of the dryer was 10000 g.The rotational speed of the inner drum was controlled.The thermal energy required for the dryer was provided by a solar absorber plate.The dryer per-formance was examined at three levels of rotational speed(0.21,0.42 and 0.84 r.p.m.),drum slope(1°,1.5°and 2°)and air velocity(1.7,1.8 and 1.9 m.s^(-1)).The diameter of the drum was the geometrical parameter that affected the movement of the particles and the ratio of the particle diameter to the drum diameter changed with the change in the drum diameter.Therefore,increasing the diameter of the drum caused a reduction in the repose angle of the paddy without any effect on the filling angle.The displacement of the product along the drum increased with increasing slope and rotational speed.At the lowest air velocity,the time required to remove moisture(<13%)was less.The results showed a significant reduction in cracked brown rice for the paddy dried by the drum dryer at 43-46℃ compared with those dried using a batch dryer.The highest stress-cracking index(11)was observed for the paddy with an initial moisture of 16%.The results showed that for proportional final moisture content,a longer drum should be considered to intensify the slope and rotational speed of the inner drum.展开更多
Plants are capable of reducing environmental pollutions through uptaking contaminants in their tissues. In the study site, twenty one-year-old leaves and shoots as well as twenty soil samples were sampled and analyzed...Plants are capable of reducing environmental pollutions through uptaking contaminants in their tissues. In the study site, twenty one-year-old leaves and shoots as well as twenty soil samples were sampled and analyzed by Inductively Coupled Plasma （ICP）. We investigated the uptaking ability of lead （Pb） and cadmium （Cd） by the leaves and shoots of Platanus orientalis, Robinia pseudoacacia and Fraxinus rotundifolia in Karaj city, the western Tehran, Iran. We also evaluated the total metal accumulation capacity by using metal accumulation index （MAI）. Results indicated that there was no significant difference in uptaking contents of Cd and Pb in the leaves among the trees. However accumulation of Cd in shoots of F. rotundifolia and R. pseudoacacia was significantly higher than that of P. orientalis. The accumulation of Pb in shoots of R. pseudoacacia was significantly higher than the other species. The amount of Pb in the soil of the study area was significantly higher than Cd. Concentrations of Cd and Pb in leaves of the three species are in the ranges of 2.4 2.7 mg Kg-1 and 7.1 14.4 mg Kg-1 , respectively. R. pseudoacacia had the highest MAI value for leaves （2.21） and F. rotundifolia had the highest MAI value for shoots （2.4）.展开更多
AIM:To investigate the presence of mixed infection and discrepancy between hepatitis C virus(HCV) genotypes in plasma,peripheral blood mononuclear cells(PBMCs),and liver biopsy specimens.METHODS:From September 2008 up...AIM:To investigate the presence of mixed infection and discrepancy between hepatitis C virus(HCV) genotypes in plasma,peripheral blood mononuclear cells(PBMCs),and liver biopsy specimens.METHODS:From September 2008 up to April 2009,133 patients with chronic hepatitis C referred to Firouzgar Hospital for initiation of an antiviral therapy were recruited in the study.Five milliliters of peripheral blood was collected from each patient and liver biopsy was performed in those who gave consent or had indications.HCV genotyping was done using INNO-LiPATM HCV in serum,PBMCs,and liver biopsy specimens and then conf irmed by sequencing of 5'-UTR fragments.RESULTS:The mean age of patients was 30.3 ± 17.1 years.Multiple transfusion was seen in 124(93.2%) of patients.Multiple HCV genotypes were found in 3(2.3%) of 133 plasma samples,9(6.8%) of 133 PBMC samples,and 8(18.2%) of 44 liver biopsy specimens.It is notable that the different genotypes found in PBMCs were not the same as those found in plasma and liver biopsy specimens.CONCLUSION:Our study shows that a signif icant proportion of patients with chronic hepatitis C are affected by multiple HCV genotypes which may not be detectable only in serum of patients.展开更多
Hydrogels with their time-dependent intrinsic behaviors have recently been used widely in soft structures as sensors/actuators.One of the most interesting structures is the bilayer made up of hydrogels which may under...Hydrogels with their time-dependent intrinsic behaviors have recently been used widely in soft structures as sensors/actuators.One of the most interesting structures is the bilayer made up of hydrogels which may undergo swelling-induced bending.In this work,by proposing a semi-analytical method,the transient bending of hydrogel-based bilayers is investigated.Utilizing nonlinear solid mechanics,a robust semi-analytical solution is developed which captures the transient finite bending of hydrogel-based bilayers.Moreover,the multiphysics model of the hydrogels is implemented in the finite element method(FEM) framework to verify the developed semi-analytical procedure results.The effects of different material properties are investigated to illustrate the nonlinear behavior of these structures.The von-Mises stress contour extracted from FEM shows that the critical area of these soft structures is at the interface of the layers which experiences the maximum stress,and this area is most likely to rupture in large deformations.展开更多
Objectives: To analyze the role of nurse staffing in improving patient safety due to reducing surgical complications in member countries of Organization for Economic Co-operation and Development (OECD).Methods: The nu...Objectives: To analyze the role of nurse staffing in improving patient safety due to reducing surgical complications in member countries of Organization for Economic Co-operation and Development (OECD).Methods: The number of practicing nurses' density per 1000 population and five surgical complications indicators including foreign body left in during procedure (FBL),postoperative pulmonary embolism (PPE) and deep vein thrombosis (DVT) after hip and knee replacement,postoperative sepsis after abdominal surgery (PSA) and postoperative wound dehiscence (PWD) were collected in crude rates per 100,000 hospital discharges for age group of 15 years old and over within 30 days after surgery based on surgical admission-related and all admission-related methods.The observations of 21 OECD countries were collected from OECD Health Statistics during 2010-2015 period.The statistical technique of panel data analysis including unit root test,co-integration test and dynamic long-run analysis were used to estimate the possible relationship between our panel series.Results: There were significant relationships from nurse-staffing level to reducing FBL,PPE,DVT,PSA and PWD with long-run magnitudes of-2.91,-1.30,-1.69,-2.81 and-1.12 based on surgical admission method as well as-6.12,-14.57,-7.29,-1.41 and-0.88 based on all admission method,respectively.Conclusions: A higher proportion of nurses is associated with higher patient safety resulting from lower surgical complications and adverse clinical outcomes in OECD countries.Hence,we alert policy makers about the risk of underestimating the impact of nurses on improving patient safety as well as the quality of health care services in OECD countries.展开更多
In this study,a new system consisting of a combination of braces and steel infill panels called the braced corrugated steel shear panel(BCSSP)is presented.To obtain the hysteretic behavior of the proposed system,the q...In this study,a new system consisting of a combination of braces and steel infill panels called the braced corrugated steel shear panel(BCSSP)is presented.To obtain the hysteretic behavior of the proposed system,the quasistatic cyclic performances of two experimental specimens were first evaluated.The finite element modeling method was then verified based on the obtained experimental results.Additional numerical evaluations were carried out to investigate the effects of different parameters on the system.Subsequently,a relationship was established to estimate the buckling shear strength of the system without considering residual stresses.The results obtained from the parametric study indicate that the corrugated steel shear panel(CSSP)with the specifications of a=30 mm,t=2 mm,andθ=90°had the highest energy dissipation capacity and ultimate strength while the CSSP with the specifications of a=30 mm,t=2 mm,andθ=30°had the highest initial stiffness.It can thus be concluded that the latter CSSP has the best structural performance and that increasing the number of corrugations,corrugation angle,and plate thickness and decreasing the sub-panel width generally enhance the performance of CSSPs in terms of the stability of their hysteretic behaviors.展开更多
Purpose:Abdominal CT scan using oral and intravenous(IV)contrast is helpful in the diagnosis of intra-abdominal injuries.However,the use of oral and IV contrast delays the process of diagnosis and increases the risk o...Purpose:Abdominal CT scan using oral and intravenous(IV)contrast is helpful in the diagnosis of intra-abdominal injuries.However,the use of oral and IV contrast delays the process of diagnosis and increases the risk of aspiration.It has also been shown that CT scan with IV contrast alone is as helpful as CT scan with oral and IV contrast and rectal CT scan in detecting abdominal injuries.Therefore,the present study aims to prospectively compare the diagnostic value of CT scan with oral and IV contrast versus CT scan with IV contrast alone in the diagnosis of blunt abdominal trauma(BAT).Methods:Altogether 123 BAT patients,60(48.8%)women and 63(51.2%)men with the mean age of(40.4±18.7)years who referred to the emergency department of Imam Khomeini Educational and Medical Center in Sari,Iran(a tertiary trauma center in north of Iran)from November 2014 to March 2017 and underwent abdominal CT scans+laparotomy were investigated.Those with penetrating trauma or hemodynamically unstable patients were excluded.The participants were randomly allocated to two groups:abdominal CT scan with oral and IV contrast(n=63)and CT scan with IV contrast alone(n=60).No statistically significant difference was found between two groups regarding the hemodynamic parameters,age,gender,injury mechanisms(all p>0.05).The results of CT scan were compared with that of laparotomy results.The collected data were recorded in SPSS version 22.0 for Windows.Quantitative data were presented as mean and SD.Results:The sensitivity and specificity of CT scan using oral and IV contrast in the diagnosis of BAT were estimated at 96.48(95%CI:90.73-99.92)and 92.67(95% CI:89.65-94.88),respectively;while CT scan with IV contrast alone achieved a comparable sensitivity and specificity of 96.6(95% CI:87.45-99),42 and 92.84(95% CI:89.88-95.00),respectively.Conclusion:CT scan with IV contrast alone can be used to assess visceral injuries in BAT patients with normal hemodynamics to avoid diagnostic delay.展开更多
基金the National Natural Science Foundation of China(Nos.52031007,52171077)partial support of his contribution to the work by the University of California at Berkeley。
文摘Corrosion degradation is detrimental to metal structures as it shortens their lifetime and leads to huge economic losses and unexpected disasters.Therefore,the detection and monitoring of corrosion degradation is of great importance.Herein,we briefly review the state-of-the-art electrochemical methods,instrumentation(based on virtual instrumentation),and advanced sensor/probes that are used in the field for the assessment of corrosion damage.Typical corrosion monitoring results,some of which have been obtained at Tianjin University in the past 30 years,for metallic materials and organic coating/metal systems in atmospheric,marine,and soil conditions in the field are presented.Detection methods,data analysis,and theoretical and mathematical models regarding each corrosion system are discussed,and the challenges,problems and possible solutions for each case are suggested.Lastly,future developments,such as wireless,intelligent,and automatic electrochemical measurement,that will augment the present electrochemical methods of evaluating corrosion degradation are summarized.
文摘In this study, a new mathematical model is developed composed of two parts, including harmonic and polynomial expressions for simulating the dominant velocity pulse of near fault ground motions. Based on a proposed velocity function, the corresponding expressions for the ground acceleration and displacement time histories are also derived. The proposed model is then fitted using some selected pulse-like near fault ground motions in the Next Generation Attenuation （NGA） project library. The new model is not only simple in form but also simulates the long-period portion of actual velocity near fault records with a high level of precision. It is shown that the proposed model-based elastic response spectra are compatible with the near fault records in the neighborhood of the prevailing frequency of the pulse. The results indicate that the proposed model adequately simulates the components of the time histories. Finally, the energy of the proposed pulse was compared with the energy of the actual record to confirm the compatibility.
文摘The K-means algorithm is one of the most popular techniques in clustering. Nevertheless, the performance of the Kmeans algorithm depends highly on initial cluster centers and converges to local minima. This paper proposes a hybrid evolutionary programming based clustering algorithm, called PSO-SA, by combining particle swarm optimization (PSO) and simulated annealing (SA). The basic idea is to search around the global solution by SA and to increase the information exchange among particles using a mutation operator to escape local optima. Three datasets, Iris, Wisconsin Breast Cancer, and Ripley's Glass, have been considered to show the effectiveness of the proposed clustering algorithm in providing optimal clusters. The simulation results show that the PSO-SA clustering algorithm not only has a better response but also converges more quickly than the K-means, PSO, and SA algorithms.
文摘One goal in the face of drought stress conditions is to increase growth and yield through the reduction of negative effects of stress. Vermicompost can play an effective role in plant growth and development and in reducing harmful effects of various environmental stresses on plants due to its porous structure, high water storage capacity, having hormone-like substances, plant growth regulators, and high levels of macro and micro nutrients. This study considered the physiological, biochemical, and photosynthetic responses of the chickpea to different combinations of vermicompost and water stress in a greenhouse environment. Two factors were involved, addition of vermicompost to soil at four ratios： control （100 wt% （weight percentage） sol0; 10 wt% vermicompost＋90% soil; 20 wt% vermicompost＋80 wt% soil; 30 wt% vermicompost＋70 wt% soil weight percentage, and treatment of water stress at three levels including 75, 50, and 25% of field capacity. The results showed that vermicompost had a significant effect on all traits under stress and non-stress conditions. Application of vermicompost in soil, especially at the levels of 20 and 30 wt% significantly increased all studied traits under non-stress conditions. Under moderate stress conditions, vermicompost at 30 wt% treatment resulted in a significant increase in the photosynthetic pigments, CO2 assimilation rate, internal leaf CO2 concentration, transpiration, the maximal quantum yield of photosystem II （PSII） photochemistry （FJF）, concentrations of Ca and K in root and leaf tissues, proline and soluble protein contents in root tissues. Peroxidase （POX） and catalase （CAT） enzyme activities decreased significantly with increasing proportions of vermicompost, but the activity of superoxide dismutase was not significantly different. In conclusion, the above results showed that vermicompost fertilizer had a positive effect on physiological, biochemical, and photosynthetic responses of chickpea under non-stress and moderate stress conditions, bu
基金the council of Iran National Science Foundation and University of Kashan for supporting this work by Grant No (159271/999)
文摘In this work we synthesize a novel and highly efficient photocatalyst for degradation of methyl orange and rhodamine B. In addition, a new method for synthesis of FeO@SiO@TiO@Ho magnetic core-shell nanoparticles with spherical morphology is proposed. The crystal structures, morphology and chemical properties of the as-synthesized nanoparticles were characterized using Fourier transform infrared spectroscopy（FT-IR）, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, energy dispersive X-ray（EDS）, X-ray diffraction（XRD）, UV–vis diffuse reflectance spectroscopy（DRS） and vibrating sample magnetometer（VSM） techniques. The photocatalytic activity of FeO@SiO@TiO@Ho was investigated by degradation of methyl orange（MO） as cationic dye and rhodamine B（Rh B） as anionic dye in aqueous solution under UV/vis irradiation. The results indicate that about 92.1% of Rh B and78.4% of MO were degraded after 120 and 150 min, respectively. These degradation results show that FeO@SiO@TiO@Ho nanoparticles are better photocatalyst than Fe3O4@Si O2@TiO 2@Ho for degradation of MO and Rh B. As well as, the catalyst shows high recovery and stability even after several separation cycles.
基金Supported by The Gastrointestinal and Liver Disease Research Center of Tehran University of Medical Sciences
文摘AIM: To investigate the accuracy of T2*-weighted magnetic resonance imaging (MRI T2*) in the evaluation of iron overload in beta-thalassemia major patients. METHODS: In this cross-sectional study, 210 patients with beta-thalassemia major having regular blood transfusions were consecutively enrolled. Serum ferritin levels were measured, and all patients underwent MRI T2* of the liver. Liver biopsy was performed in 53 patients at an interval of no longer than 3 mo after the MRIT2* in each patient. The amount of iron was assessed in both MRI T2* and liver biopsy specimens of each patient. RESULTS: Patients’ ages ranged from 8 to 54 years with a mean of 24.59 ± 8.5 years. Mean serum ferritin level was 1906 ± 1644 ng/mL. Liver biopsy showed a moderate negative correlation with liver MRI T2* (r = -0.573, P = 0.000) and a low positive correlation with ferritin level (r = 0.350, P = 0.001). Serum ferritin levels showed a moderate negative correlation with liver MRI T2* values (r = -0.586, P = 0.000). CONCLUSION: Our study suggests that MRI T2* is a non-invasive, safe and reliable method for detecting iron load in patients with iron overload.
文摘Objective:To investigate the epidemiological situation of animal bites in Rostam city of Fars province.Methods:This is a cross-sectional study.Cases of animal bites registered in health centers of Rostam city of Fars province from the beginning of 2014 to 2020 were analyzed using the census method.The tool for collecting information was the portal of the Ministry of Health and the registration offices of people who were referred to the rabies center.Results:A total of 628 cases of animal bites registered in health centers of Rostam city of Fars province from the beginning of 2014 to 2020.The mean age of the injured was(31.3±20.2)years.Of the total injured cases,414(65.9%)were male,and 491(78.2%)lived in villages.Most of the cases were bitten by dogs(n=420,66.8%)and the upper limb was involved in 280(55.2%)cases.In addition,an increasing trend was observed in the incidence of animal bites from 2015 to 2020.Conclusions:The incidence of animal bites in Rostam City is high,and most of the cases occur in rural areas.Considering the injuries caused by animal bites,the risk of rabies transmission,and the high costs of vaccination and serum therapy,it is necessary to hold control,educational,and vaccination programs.
文摘Objective:To investigate the distribution pattern of animal bites in Mirjaveh,Iran from 2015 to 2020.Methods:The data on animal bites were collected from the Department of Infectious Diseases,the provincial health center.Monthly climatic data on precipitation and temperature during the study period were also collected.The correlation between incidence and temperature,precipitation rate,land type,and altitude was also analyzed.Results:The results showed that men were more affected by animal bites than women(76.4%,P<0.001),and the highest incidence rate occurred in the age group of 5-19 years.The incidence rate of animal bites was found to be correlated with temperature and altitude.An increase in temperature was associated with a rise in the incidence rate of animal bites.The number of animal bites increased until 2019,possibly due to an increase in the number of dogs in the area.Conclusions:Targeted interventions should be implemented to reduce the incidence of animal bites,particularly among children,housewives,and students.Improving access to appropriate treatments,increasing public awareness of the hazards of animal bites,and increasing the number of vaccinated dogs in the area are essential strategies to be considered.
文摘Background Probiotic supplementation has been used to alleviate abdominal pain in children and adolescents with irritable bowel syndrome(IBS),but the evidence is not compelling.Thus,a systematic review and meta-analysis of randomized clinical trials(RCTs)were performed to investigate the effects of probiotic supplementation on abdominal pain in pediatric patients with IBS.Methods PubMed/MEDLINE,Web of Science,Scopus,Cochrane Library,and Embase were the available databases searched to find relevant randomized clinical trials up to April 2021.The effect size was expressed as weighted mean differenee(WMD)and 95% confidence interval(CI).Results Seven RCTs with 441 participants were included,from which the meta-analysis demonstrated that probiotic supplementation has a significant effect on reducing abdominal pain in pediatric patients with IBS(WMD=-2.36:95%CI-4.12 to-0.60;P=0.009).Although our study involved children and adolescents(≤18 years),the effects of probiotic supplementation seem to be more potent in patients under 10 years old(WMD=-2.55;95%CI-2.84 to -2.27)compared to patients aged 10-18 years(WMD=-1.70;95%CI-2.18 to -1.22).The length of supplementation longer than four weeks was more effective(WMD=-2.43;95%CI-2.76 to -2.09).Conclusion Probiotic supplementation can reduce abdominal pain in pediatric patients with IBS.
文摘In this paper, we present a comprehensive numerical simulation of a point wave absorber in deep water. Analyses are performed in both the frequency and time domains. The converter is a two-body floating-point absorber （FPA） with one degree of freedom in the heave direction. Its two parts are connected by a linear mass-spring-damper system. The commercial ANSYS-AQWA software used in this study performs well in considering validations. The velocity potential is obtained by assuming incompressible and irrotational flow. As such, we investigated the effects of wave characteristics on energy conversion and device efficiency, including wave height and wave period, as well as the device diameter, draft, geometry, and damping coefficient. To validate the model, we compared our numerical results with those from similar experiments. Our study results can clearly help to maximize the converter＇s efficiency when considering specific conditions.
基金supported by the program "Biological Diversity–Gene Foundation and Genetic Diversity" of the Presidium of the Russian Academy of Sciences and the Russian Foundation for Basic Research (project nos. 08-04-90410-Ykp-a, 05-04-49186-a, 04-04-81039-Bel_a)
文摘We report the expression profile of acyl-lipid △12-desaturase （desA） gene from Synechocystis sp. PCC6803 and its effect on cell membrane lipid composition and cold tolerance in prokaryotic （Escherichia coil） and eukaryotic （Solanum tuberosum） cells. For this purpose, a hybrid of desA and reporter gene encoding thermostable lichenase （licBM3） was constructed and used to transform these cells. The expression of this hybrid gene was measured using qualitative （Petri dish test, electrophoregram and zymogram） and quantitative methods （spectrometry and gas liquid chromatography assays）. The maximum level of linoleic acid in the bacterial cells containing hybrid gene was 1.9% of total fatty acids. Cold stress tolerance assays using plant damage index and growth parameters showed that cold tolerance was enhanced in primary transgenic lines because of increased unsaturated fatty acid concentration in their lipids. The greatest content of 18：2 and 18：3 fatty acids in primary transgenic plants was observed for lines 2 （73%） and 3 （41%）. Finally, our results showed that desaturase could enhance tolerance to cold stress in potato, and desaturase and lichenase retain their functionality in the structure of the hybrid protein where the enzymatic activity of target gene product was higher than in the case of reporter lichenase gene absence in the construction.
文摘The present study is aimed to investigate the ability of different intensity measures （IMs）, including response spectral acceleration at the fundamental period of the structure, Sa（T1）, as a common scalar IM and twelve vector-valued IMs for seismic collapse assessment of structures. The vector-valued IMs consist of two components, with S（T1） as the first component and different parameters that are ratios of scalar IMs, as well as the spectral shape proxies εSa and N, as the second component. After investigating the properties of an optimal IM, a new vector-valued IM that includes the ratio of Sa（T1） to the displacement spectrum intensity （DSI） as the second component is proposed. The new IM is more efficient than other IMs for predicting the collapse capacity of structures. It is also sufficient with respect to magnitude, source-to-site distance, and scale factor for collapse capacity prediction of structures. To satisfy the predictability criterion, a ground motion prediction equation （GMPE） is determined for Sa（T1）/DSI by using the existing GMPEs. Furthermore, an empirical equation is proposed for obtaining the correlation between the components of the proposed IM. The results of this study show that using the new vector-valued IM leads to a more reliable seismic collapse assessment of structures.
文摘The influences of the dissimilarity in the roll speeds on the microstructure, texture and mechanical properties of 7075 aluminum plates produced via combined continuous casting and rolling(CCCR) process were investigated. Several experiments were conducted with three different upper/lower roll rotational speed ratios(ω/ω0, ω is the upper roll rotational speed and ω0 is the lower roll rotational speed), namely 1:1, 1:1.2 and 1:1.4. It was found that the greatest dissimilarity in the roll speed(ω/ω0=1:1.4) improved the yield strength and ultimate tensile strength of 7075 Al plate in the rolling direction by 41.5% and 21.9%, respectively. Moreover, at a roll speed ratio of ω/ω0=1:1.4, the average grain size was decreased by 36% whereas the mean hardness of the transverse cross-section of the finally rolled plate was increased by about 9.2%. Texture studies also revealed that the more the difference in the roll speeds was, the greater the isotropy and the hardness of the final product were. Nevertheless, conducting CCCR operation with different roll speeds resulted in about 6% reduction in the elongation of the deformed plate.
文摘A solar drum dryer was designed and constructed for paddy drying,including a fixed outer drum and inner perforated drum,which rotated at the desired rotational speed inside the outer drum.The maximum capacity of the dryer was 10000 g.The rotational speed of the inner drum was controlled.The thermal energy required for the dryer was provided by a solar absorber plate.The dryer per-formance was examined at three levels of rotational speed(0.21,0.42 and 0.84 r.p.m.),drum slope(1°,1.5°and 2°)and air velocity(1.7,1.8 and 1.9 m.s^(-1)).The diameter of the drum was the geometrical parameter that affected the movement of the particles and the ratio of the particle diameter to the drum diameter changed with the change in the drum diameter.Therefore,increasing the diameter of the drum caused a reduction in the repose angle of the paddy without any effect on the filling angle.The displacement of the product along the drum increased with increasing slope and rotational speed.At the lowest air velocity,the time required to remove moisture(<13%)was less.The results showed a significant reduction in cracked brown rice for the paddy dried by the drum dryer at 43-46℃ compared with those dried using a batch dryer.The highest stress-cracking index(11)was observed for the paddy with an initial moisture of 16%.The results showed that for proportional final moisture content,a longer drum should be considered to intensify the slope and rotational speed of the inner drum.
基金The project was financially supported by parks organization of Karaj municipality
文摘Plants are capable of reducing environmental pollutions through uptaking contaminants in their tissues. In the study site, twenty one-year-old leaves and shoots as well as twenty soil samples were sampled and analyzed by Inductively Coupled Plasma （ICP）. We investigated the uptaking ability of lead （Pb） and cadmium （Cd） by the leaves and shoots of Platanus orientalis, Robinia pseudoacacia and Fraxinus rotundifolia in Karaj city, the western Tehran, Iran. We also evaluated the total metal accumulation capacity by using metal accumulation index （MAI）. Results indicated that there was no significant difference in uptaking contents of Cd and Pb in the leaves among the trees. However accumulation of Cd in shoots of F. rotundifolia and R. pseudoacacia was significantly higher than that of P. orientalis. The accumulation of Pb in shoots of R. pseudoacacia was significantly higher than the other species. The amount of Pb in the soil of the study area was significantly higher than Cd. Concentrations of Cd and Pb in leaves of the three species are in the ranges of 2.4 2.7 mg Kg-1 and 7.1 14.4 mg Kg-1 , respectively. R. pseudoacacia had the highest MAI value for leaves （2.21） and F. rotundifolia had the highest MAI value for shoots （2.4）.
基金Supported by Local Fund from Iran University of Medical Sciences
文摘AIM:To investigate the presence of mixed infection and discrepancy between hepatitis C virus(HCV) genotypes in plasma,peripheral blood mononuclear cells(PBMCs),and liver biopsy specimens.METHODS:From September 2008 up to April 2009,133 patients with chronic hepatitis C referred to Firouzgar Hospital for initiation of an antiviral therapy were recruited in the study.Five milliliters of peripheral blood was collected from each patient and liver biopsy was performed in those who gave consent or had indications.HCV genotyping was done using INNO-LiPATM HCV in serum,PBMCs,and liver biopsy specimens and then conf irmed by sequencing of 5'-UTR fragments.RESULTS:The mean age of patients was 30.3 ± 17.1 years.Multiple transfusion was seen in 124(93.2%) of patients.Multiple HCV genotypes were found in 3(2.3%) of 133 plasma samples,9(6.8%) of 133 PBMC samples,and 8(18.2%) of 44 liver biopsy specimens.It is notable that the different genotypes found in PBMCs were not the same as those found in plasma and liver biopsy specimens.CONCLUSION:Our study shows that a signif icant proportion of patients with chronic hepatitis C are affected by multiple HCV genotypes which may not be detectable only in serum of patients.
文摘Hydrogels with their time-dependent intrinsic behaviors have recently been used widely in soft structures as sensors/actuators.One of the most interesting structures is the bilayer made up of hydrogels which may undergo swelling-induced bending.In this work,by proposing a semi-analytical method,the transient bending of hydrogel-based bilayers is investigated.Utilizing nonlinear solid mechanics,a robust semi-analytical solution is developed which captures the transient finite bending of hydrogel-based bilayers.Moreover,the multiphysics model of the hydrogels is implemented in the finite element method(FEM) framework to verify the developed semi-analytical procedure results.The effects of different material properties are investigated to illustrate the nonlinear behavior of these structures.The von-Mises stress contour extracted from FEM shows that the critical area of these soft structures is at the interface of the layers which experiences the maximum stress,and this area is most likely to rupture in large deformations.
文摘Objectives: To analyze the role of nurse staffing in improving patient safety due to reducing surgical complications in member countries of Organization for Economic Co-operation and Development (OECD).Methods: The number of practicing nurses' density per 1000 population and five surgical complications indicators including foreign body left in during procedure (FBL),postoperative pulmonary embolism (PPE) and deep vein thrombosis (DVT) after hip and knee replacement,postoperative sepsis after abdominal surgery (PSA) and postoperative wound dehiscence (PWD) were collected in crude rates per 100,000 hospital discharges for age group of 15 years old and over within 30 days after surgery based on surgical admission-related and all admission-related methods.The observations of 21 OECD countries were collected from OECD Health Statistics during 2010-2015 period.The statistical technique of panel data analysis including unit root test,co-integration test and dynamic long-run analysis were used to estimate the possible relationship between our panel series.Results: There were significant relationships from nurse-staffing level to reducing FBL,PPE,DVT,PSA and PWD with long-run magnitudes of-2.91,-1.30,-1.69,-2.81 and-1.12 based on surgical admission method as well as-6.12,-14.57,-7.29,-1.41 and-0.88 based on all admission method,respectively.Conclusions: A higher proportion of nurses is associated with higher patient safety resulting from lower surgical complications and adverse clinical outcomes in OECD countries.Hence,we alert policy makers about the risk of underestimating the impact of nurses on improving patient safety as well as the quality of health care services in OECD countries.
文摘In this study,a new system consisting of a combination of braces and steel infill panels called the braced corrugated steel shear panel(BCSSP)is presented.To obtain the hysteretic behavior of the proposed system,the quasistatic cyclic performances of two experimental specimens were first evaluated.The finite element modeling method was then verified based on the obtained experimental results.Additional numerical evaluations were carried out to investigate the effects of different parameters on the system.Subsequently,a relationship was established to estimate the buckling shear strength of the system without considering residual stresses.The results obtained from the parametric study indicate that the corrugated steel shear panel(CSSP)with the specifications of a=30 mm,t=2 mm,andθ=90°had the highest energy dissipation capacity and ultimate strength while the CSSP with the specifications of a=30 mm,t=2 mm,andθ=30°had the highest initial stiffness.It can thus be concluded that the latter CSSP has the best structural performance and that increasing the number of corrugations,corrugation angle,and plate thickness and decreasing the sub-panel width generally enhance the performance of CSSPs in terms of the stability of their hysteretic behaviors.
基金The present study was based on a doctoral dissertation in the Emergency Medicine,School of Medicine,Mazandaran University of Medical Sciences,Iran(grant number 1404)。
文摘Purpose:Abdominal CT scan using oral and intravenous(IV)contrast is helpful in the diagnosis of intra-abdominal injuries.However,the use of oral and IV contrast delays the process of diagnosis and increases the risk of aspiration.It has also been shown that CT scan with IV contrast alone is as helpful as CT scan with oral and IV contrast and rectal CT scan in detecting abdominal injuries.Therefore,the present study aims to prospectively compare the diagnostic value of CT scan with oral and IV contrast versus CT scan with IV contrast alone in the diagnosis of blunt abdominal trauma(BAT).Methods:Altogether 123 BAT patients,60(48.8%)women and 63(51.2%)men with the mean age of(40.4±18.7)years who referred to the emergency department of Imam Khomeini Educational and Medical Center in Sari,Iran(a tertiary trauma center in north of Iran)from November 2014 to March 2017 and underwent abdominal CT scans+laparotomy were investigated.Those with penetrating trauma or hemodynamically unstable patients were excluded.The participants were randomly allocated to two groups:abdominal CT scan with oral and IV contrast(n=63)and CT scan with IV contrast alone(n=60).No statistically significant difference was found between two groups regarding the hemodynamic parameters,age,gender,injury mechanisms(all p>0.05).The results of CT scan were compared with that of laparotomy results.The collected data were recorded in SPSS version 22.0 for Windows.Quantitative data were presented as mean and SD.Results:The sensitivity and specificity of CT scan using oral and IV contrast in the diagnosis of BAT were estimated at 96.48(95%CI:90.73-99.92)and 92.67(95% CI:89.65-94.88),respectively;while CT scan with IV contrast alone achieved a comparable sensitivity and specificity of 96.6(95% CI:87.45-99),42 and 92.84(95% CI:89.88-95.00),respectively.Conclusion:CT scan with IV contrast alone can be used to assess visceral injuries in BAT patients with normal hemodynamics to avoid diagnostic delay.
