We systematically reviewed the clinical trials which recruited antioxidants in the therapy of pancreatitis and evaluated whether antioxidants improve the outcome of patients with pancreatitis. Electronic bibliographic...We systematically reviewed the clinical trials which recruited antioxidants in the therapy of pancreatitis and evaluated whether antioxidants improve the outcome of patients with pancreatitis. Electronic bibliographic databases were searched for any studies which investigated the use of antioxidants in the management of acute pancreatitis （AP） or chronic pancreatitis （CP） and in the prevention of post-endoscopic retrograde cholangio-pancreatography （post-ERCP） pancreatitis （PEP） up to February 2009. Twenty-two randomized, placebo-controlled, clinical trials met our criteria and were included in the review. Except for a cocktail of antioxidants which showed improvement in outcomes in three different clinical trials, the results of the administration of other antioxidants in both AP and CP clinical trials were incongruent and heterogeneous.Furthermore, antioxidant therapy including allopurinol and N-acetylcysteine failed to prevent the onset of PEP in almost all trials. In conclusion, the present data do not support a benefit of antioxidant therapy alone or in combination with conventional therapy in the management of AP, CP or PER Further double blind, randomized, placebo-controlled clinical trials with large sample size need to be conducted.展开更多
AIM:To investigate the impact of niosome nanoparticles carrying umbelliprenin(UMB),an anti-angiogenic and anti-inflammatory plant compound,on the expression of vascular endothelial growth factor(VEGF-A)and connective ...AIM:To investigate the impact of niosome nanoparticles carrying umbelliprenin(UMB),an anti-angiogenic and anti-inflammatory plant compound,on the expression of vascular endothelial growth factor(VEGF-A)and connective tissue growth factor(CTGF)genes in a human retinal pigment epithelium(RPE)-like retina-derived cell line.METHODS:UMB-containing niosomes were created,optimized,and characterized.RPE-like cells were treated with free UMB and UMB-containing niosomes.The IC_(50)values of the treatments were determined using an MTT assay.Gene expression of VEGF-A and CTGF was evaluated using real-time polymerase chain reaction after RNA extraction and cDNA synthesis.Niosomes’characteristics,including drug entrapment efficiency,size,dispersion index,and zeta potential were assessed.Free UMB had an IC_(50)of 96.2μg/mL,while UMB-containing niosomes had an IC_(50)of 25μg/mL.RESULTS:Treatment with UMB-containing niosomes and free UMB resulted in a significant reduction in VEGF-A expression compared to control cells(P=0.001).Additionally,UMB-containing niosomes demonstrated a significant reduction in CTGF expression compared to control cells(P=0.05).However,there was no significant reduction in the expression of both genes in cells treated with free UMB.CONCLUSION:Both free UMB and niosome-encapsulated UMB inhibits VEGF-A and CTGF genes expression.However,the latter demonstrates significantly greater efficacy,potentially due to the lower UMB dosage and gradual delivery.These findings have implications for anti-angiogenesis therapeutic approaches targeting age-related macular degeneration.展开更多
Formany years,researchers have explored power allocation(PA)algorithms driven bymodels in wireless networks where multiple-user communications with interference are present.Nowadays,data-driven machine learning method...Formany years,researchers have explored power allocation(PA)algorithms driven bymodels in wireless networks where multiple-user communications with interference are present.Nowadays,data-driven machine learning methods have become quite popular in analyzing wireless communication systems,which among them deep reinforcement learning(DRL)has a significant role in solving optimization issues under certain constraints.To this purpose,in this paper,we investigate the PA problem in a k-user multiple access channels(MAC),where k transmitters(e.g.,mobile users)aim to send an independent message to a common receiver(e.g.,base station)through wireless channels.To this end,we first train the deep Q network(DQN)with a deep Q learning(DQL)algorithm over the simulation environment,utilizing offline learning.Then,the DQN will be used with the real data in the online training method for the PA issue by maximizing the sumrate subjected to the source power.Finally,the simulation results indicate that our proposedDQNmethod provides better performance in terms of the sumrate compared with the available DQL training approaches such as fractional programming(FP)and weighted minimum mean squared error(WMMSE).Additionally,by considering different user densities,we show that our proposed DQN outperforms benchmark algorithms,thereby,a good generalization ability is verified over wireless multi-user communication systems.展开更多
Objectives: This study aimed to identify coping strategies used by family caregivers of patients with schizophrenia and their determinants.Methods: This was a descriptive correlational study.Participants were 225 fami...Objectives: This study aimed to identify coping strategies used by family caregivers of patients with schizophrenia and their determinants.Methods: This was a descriptive correlational study.Participants were 225 family caregivers of patients with schizophrenia who were referred to the psychiatric clinic at one large teaching referral hospital in Iran.They were selected through purposive sampling method.Data collection tools were demographic and clinical data form,the Zarit Burden Interview (ZBI) and the Family Coping Questionnaire (FCQ).Results: The score of caregiver burden was 65.14 ± 9.17.Of 225 family caregivers,23.11% used an avoiding coping strategy.There was a significant relationship between caregiver burden and coping strategies (P < 0.001).The regression model showed that adaptive coping strategies were significantly associated with some demographic characteristics including age,education level,gender,employment status,losing the job because of caregiving responsibilities,perceived income adequacy,duration of illness,duration of caregiving and caregiver burden (P < 0.05).Conclusion: Family caregivers of patients with schizophrenia experience a high level of burden,which can put them at risk of using maladaptive coping strategies.Mental health professionals should plan programs that support both family caregivers and patients in clinical and community settings.展开更多
AIM:To evaluate the effect of auraptene(AUR)treatment in forms of free and encapsulated in niosome nanoparticles by investigating the mRNA expression level of vascular endothelium growth factor(VEGF)-A and platelet-de...AIM:To evaluate the effect of auraptene(AUR)treatment in forms of free and encapsulated in niosome nanoparticles by investigating the mRNA expression level of vascular endothelium growth factor(VEGF)-A and platelet-derived growth factors(PDGFs)in human retinal pigment epithelium(RPE)cell line.METHODS:Niosome nanocarriers were produced using two surfactants Span 60 and Tween 80.RPE cell line was treated with both free AUR and niosome-encapsulated.Optimum dosage of treatments was calculated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay.Expression of VEGF-A and PDGF-A,PDGF-B,PDGF-C,PDGF-D genes was measured after total RNA extraction and cDNA synthesis,using real-time polymerase chain reaction(RT-PCR).RESULTS:The highest entrapment efficiency(EE)was achieved by Span 60:cholesterol(1:1)with 64.3%.The half maximal inhibitory concentration(IC50)of free and niosome-encapsulated AUR were 38.5 and 27.78µg/mL,respectively.Release study revealed that niosomal AUR had more gradual delivery to the cells.RT-PCR results showed reduced expression levels of VEGF-A,PDGF-A,PDGF-B,PDGF-C,and PDGF-D after treatment with both free and niosomal AUR.CONCLUSION:Niosomal formulation of Span 60:cholesterol(1:1)is an effective drug delivery approach to transfer AUR to RPE cells.VEGF-A,PDGF-A,PDGF-B,PDGF-C,and PDGF-D are four angiogenic factors,inhibiting which by niosomal AUR may be effective in age-related macular degeneration.展开更多
In this paper, a polymer electro-optic modulator is designed and simulated using the full vectorial finite element method. First order edge elements are used in finite element implementation, and the finite element te...In this paper, a polymer electro-optic modulator is designed and simulated using the full vectorial finite element method. First order edge elements are used in finite element implementation, and the finite element technique is used to obtain modulator response thoroughly. From the numerical analysis, frequency dispersions of modulator's important parameters, such as microwave effective index nm , microwave characteristic impedance ZC and microwave loss a, are extracted. Our design exhibits electrical bandwidth of 260 GHz and drive voltage of about 2.8 V.cm in this frequency.展开更多
The purpose of active distribution networks(ADNs)is to provide effective control approaches for enhancing the operation of distribution networks(DNs)and greater accommodation of distributed generation(DG)sources.With ...The purpose of active distribution networks(ADNs)is to provide effective control approaches for enhancing the operation of distribution networks(DNs)and greater accommodation of distributed generation(DG)sources.With the integration of DG sources into DNs,several operational problems have drawn attention such as overvoltage and power flow alteration issues.These problems can be dealt with by utilizing distribution network reconfiguration(DNR)and soft open points(SOPs).An SOP is a power electronic device capable of accurately controlling active and reactive power flows.Another significant aspect often overlooked is the coordination of protection devices needed to keep the network safe from damage.When implementing DNR and SOPs in real DNs,protection constraints must be considered.This paper presents an ADN reconfiguration approach that includes DG sources,SOPs,and protection devices.This approach selects the ideal configuration,DG output,and SOP placement and control by employing particle swarm optimization(PSO)to minimize power loss while ensuring the correct operation of protection devices under normal and fault conditions.The proposed approach explicitly formulates constraints on network operation,protection coordination,DG size,and SOP size.Finally,the proposed approach is evaluated using the standard IEEE 33-bus and IEEE 69-bus networks to demonstrate the validity.展开更多
BACKGROUND:Numerous drugs have been proposed to alleviate pain in patients with biliary colic,especially opioids,but still there is a tendency to use less narcotics because of their side effects and the unwillingness ...BACKGROUND:Numerous drugs have been proposed to alleviate pain in patients with biliary colic,especially opioids,but still there is a tendency to use less narcotics because of their side effects and the unwillingness of some patients.The present study aimed to compare the analgesic effect of paracetamol combined with low-dose morphine versus morphine alone in patients with biliary colic.METHODS:A randomized double-blind controlled trial was performed in 98 patients with biliary colic,recruited from two emergency departments from August 2012 to August 2013.Eleven patients were excluded and the remaining were randomized into two groups:group A received 0.05mg/kg morphine+1 000 mg paracetamol in 100 m L normal saline and group B received 0.1 mg/kg morphine+normal saline(100 m L)as placebo.Pain scores were recorded using visual analogue scale(VAS)at baseline and 15 and 30 minutes after drug administration.Adverse effects and the need for rescue medication(0.75 g/kg intravenous fentanyl)were also reported within 60 minutes of drug administration.RESULTS:Before the infusion,the mean±SD VAS scores were 8.73±1.57 in group A and8.53±1.99 in group B.At 15 minutes after drug administration,the mean±SD VAS scores were2.16±1.90 in group A vs.2.51±1.86 in group B;mean difference was–0.35,and 95%CI–1.15 to 0.45(P=0.38).At 30 minutes the mean±SD VAS scores were 1.66±1.59 in group A vs.2.14±1.79 in group B;mean difference was–0.48,and 95%CI–1.20 to 0.24(P=0.19).The mean pain scores in the two groups at 15 and 30 minutes demonstrated no significant difference.CONCLUSION:Paracetamol combined with low-dose morphine may be effective for pain management in patients with biliary colic.展开更多
BACKGROUND: Sleep deprivation resulting from night shifts, is a major cause of burnout among physicians. Exogenous melatonin may improve sleep quality in night-shift workers. The study aims to compare the effectivenes...BACKGROUND: Sleep deprivation resulting from night shifts, is a major cause of burnout among physicians. Exogenous melatonin may improve sleep quality in night-shift workers. The study aims to compare the effectiveness of melatonin versus placebo on sleep effi ciency in emergency medicine(EM) residents. METHODS: A randomized, double-blind, replicated crossover trial was performed on EM residents. This study consisted of 4 phases within a month with intervention periods of 2 nights and washouts of 6 days. In our study, EM residents had nine-hour shifts on 6 consecutive days, 2 mornings, 2 evenings and 2 nights and then 2 days off. At the end of shifts' cycle, 24 EM residents were given 3 mg melatonin or placebo(12 in each arm of the study) for 2 consecutive nights after the second night shift with crossover to the other arm after a six-day off drug. This crossover intervention was repeated for two more another time. Finally, we created 48 cases and comparisons in each arm. Different items related to sleep quality were assessed and compared both within the same group and between the two groups. RESULTS: In the melatonin group, daytime sleepiness(calculated by Karolinska Sleep Scale) had a signifi cant reduction after taking the second dose of drug(P=0.003) but the same result was not observed when comparing the 2 groups. Mood status(calculated by Profile of Mood States) showed no remarkable difference between the 2 groups. CONCLUSION: Melatonin might have a limited benefi t on sleep quality in EM residents working night shifts.展开更多
BACKGROUND: Assessing and evaluating mental health status can provide educational planners valuable information to predict the quality of physicians' performance at work. These data can help physicians to practice...BACKGROUND: Assessing and evaluating mental health status can provide educational planners valuable information to predict the quality of physicians' performance at work. These data can help physicians to practice in the most desired way. The study aimed to evaluate factors affecting psychological morbidity in Iranian emergency medicine practitioners at educational hospitals of Tehran.METHODS: In this cross sectional study 204 participants(emergency medicine residents and specialists) from educational hospitals of Tehran were recruited and their psychological morbidity was assessed by using a 28-question Goldberg General Health Questionnaire(GHQ-28). Somatization, anxiety and sleep disorders, social dysfunction and depression were evaluated among practitioners and compared to demographic and job related variables.RESULTS: Two hundreds and four participants consisting of 146(71.6%) males and 58(28.4%) females were evaluated. Of all participants, 55(27%) were single and 149(73%) were married. Most of our participants(40.2%) were between 30–35 years old. By using GHQ-28, 129(63.2%) were recognized as normal and 75(36.8%) suffered some mental health disorders. There was a signifi cant gender difference between normal practitioners and practitioners with disorder(P=0.02) while marital status had no significant difference(P=0.2). Only 19(9.3%) declared having some major mental health issue in the previous month.CONCLUSION: Females encountered more mental health disorders than male(P=0.02) and the most common disorder observed was somatization(P=0.006).展开更多
Accurate estimation of sediment load or transport rate is very important to a wide range of water resources projects. This study was undertaken to determine the most appropriate model to predict suspended load in the ...Accurate estimation of sediment load or transport rate is very important to a wide range of water resources projects. This study was undertaken to determine the most appropriate model to predict suspended load in the Chelehay Watershed, northeast of Iran. In total, 59 data series were collected from four gravel bed-rivers and a sand bed river and two depth integrating suspended load samplers to evaluate nine suspended load formulas and feed forward backpropagation Artificial Neural Network （ANN） structures. Although the Chang formula with higher correlation coefficient （r = 0.69） and lower Root Mean Square Error （RMSE = 0.013） is the best suspended load predictor among the nine studied formulas, the ANN models significantly outperform traditional suspended load formulas and show their superior performance for all statistical parameters. Among different ANN structures two models inclu- ding 4 inputs, 4 hidden and one output neurons, and 4 inputs, 4 and one hidden and one output neurons provide the best simulation with the RMSE values of 0.0009 and 0.001, respectively.展开更多
BACKGROUND: Rapid and effective pain relief in acute traumatic limb injuries(ATLI) is one of the most important roles of emergency physicians. In these situations, opioid addiction is an important concern because of t...BACKGROUND: Rapid and effective pain relief in acute traumatic limb injuries(ATLI) is one of the most important roles of emergency physicians. In these situations, opioid addiction is an important concern because of the dependency on opioids. The study aims to compare the effectiveness of intravenous(IV) fentanyl versus morphine in reducing pain in patients with opioid addiction who suffered from ATLI.METHODS: In this double-blind randomized clinical trial, 320 patients with ATLI, who presented to the emergency department(ED) from February 2016 to April 2016, were randomly divided into two groups. One group(160 patients) received 0.1 mg/kg IV morphine. The other group(160 patients) received 1 mcg/kg IV fentanyl. Patients' demographic data, pain score at specif ic intervals, vital signs, side effects, satisfaction and the need for rescue analgesia were recorded.RESULTS: Eight patients in the morphine group and five patients in the fentanyl group were excluded. Pain score in the fentanyl group had a significant decrease at 5-minute follow-up(P value=0.00). However, at 10, 30, and 60-minute follow-ups no signifi cant differences were observed between the two groups in terms of pain score reduction. The rescue analgesia was required in 12(7.7%) patients in the fentanyl group and in 48(31.6%) patients in the morphine group(P value=0.00). No signifi cant difference was observed regarding side effects, vital signs and patients' satisfaction between the two groups.CONCLUSION: Fentanyl might be an effective and safe drug in opioid addicts suffering from ATLI.展开更多
In this paper, a polymer electro-optic mod- ulator has been designed and optimized using the full vectorial finite element method. For this purpose, the effects of magnesium oxide （MgO） and down cladding thicknesses...In this paper, a polymer electro-optic mod- ulator has been designed and optimized using the full vectorial finite element method. For this purpose, the effects of magnesium oxide （MgO） and down cladding thicknesses, distance between two ground electrodes, hot electrode and modulator widths modulator on the key modulator parameters, such as microwave effective index r/m, the characteristic impedance Zc and the microwave losses a are presented. After selecting optimal dimensions of polymer electro-optic modulator, frequency dependent aforementioned parameters and the half-wave voltage- length product （VπL） parameter of polymer electro-optic modulator are extracted and as a consequence, an optimized design is reported. Finally, the optical and electrical modulation responses of polymer electro-optic modulator are calculated. The optimized polymer electro- optic modulator exhibits 3-dB electrical bandwidth of 260 GHz and VπL about 2.8 V- cm in this frequency.展开更多
Al-20Si-5Fe melt was rapidly solidified into particles and ribbons and then consolidated to near full density by hot pressing at 400℃/250 MPa/1 h. According to the eutectic-growth and dendritic-growth velocity models...Al-20Si-5Fe melt was rapidly solidified into particles and ribbons and then consolidated to near full density by hot pressing at 400℃/250 MPa/1 h. According to the eutectic-growth and dendritic-growth velocity models, the solidification front velocity and the amount of undercooling were estimated for the particles with different sizes. Values of 0.43-1.2 cm/s and 15-28 K were obtained. The secondary dendrite arm spacing revealed a cooling rate of 6 × 10^5 K/s for the particles with an average size of 20 μm. Solidification models for the ribbons yielded a cooling rate of 5 × 10^7 K/s. As a result of the higher cooling rate, the melt-spun ribbons exhibited considerable microstructural refinement and modification. The size of the primary silicon decreased from approximately 1μm to 30 nm while the formation of iron-containing intermetallic compounds was suppressed. Supersaturation of the aluminum matrix in an amount of-7 at.% Si was noticed from the XRD patterns During the hot consolidation process, coarsening of the primary silicon particles and precipitation of β-Al5FeSi phase were observed. Evaluation of the compressive strength and hardness of the alloy indicated an improvement in mechanical properties due to the microstructural modification.展开更多
Graphene materials have drawn tremendous attention in recent years.The formation of holes and pores on graphene sheets can provide transfer channels and facilitate the ion/electron transport kinetics.In this study,gra...Graphene materials have drawn tremendous attention in recent years.The formation of holes and pores on graphene sheets can provide transfer channels and facilitate the ion/electron transport kinetics.In this study,graphene nanosheets were prepared electrochemically,and then,they were used as the starting material for the preparation of holey graphene(HG)through the KOH activation process.The weight ratio of initial electrochemically exfoliated graphene(EEG)to KOH was optimized according to the morphological features,BET surface area examination,graphene number of layers calculated from XRD patterns,and the ID/IG ratio obtained from Raman analysis.Results showed that increasing the KOH amount led to the achievement of higher values of ID/IG and surface area and less re-stacking of graphene sheets which occurs because of the heat treatment process.The environmental burdens of the production routes for the preparation of EEG and HG were investigated by cradle-to-gate life cycle assessment(LCA).The LCA results of EEG production indicated that electricity with the contributions of 94%,91%,82%,and 75%of the total impact in four environmental categories,including fossil fuel depletion,ozone depletion,global warming,and smog was the main environmental weakness.In the pore generation process,KOH was recognized as the biggest contributor(about 51%to 83%of the total impact)in six impact categories,including ozone depletion,non-carcinogenics,smog,global warming,carcinogenics,and eutrophication which could be attributed to its high consumption amount(21.9 kg).This work offers environmental considerations for the development of sustainable graphene materials.展开更多
Background: Patient self-efficacy is one of the most important factors in treating and overcoming disease. Objective: The aim of this study was to evaluate the effect of an educational program based on the health beli...Background: Patient self-efficacy is one of the most important factors in treating and overcoming disease. Objective: The aim of this study was to evaluate the effect of an educational program based on the health belief model on self-efficacy among patients with type 2 diabetes referred to the Iranian Diabetes Association in 2014. Method: A randomized controlled clinical trial was conducted. Eighty patients with type 2 diabetes were selected randomly by the double block sample method. They were then divided into two groups of intervention and control (40 patients in each group) by random allocation. Data were collected by a questionnaire based on the Health Belief Model and self-efficacy. The data were gathered two months after the educational program was held. The educational program was designed on the basis of data collected in the pre-test phase. Then, the educational program was executed for the intervention group in 8 sessions (each 30 minutes) using lectures and an educational booklet. Data analysis was done with Chi-square Test, Pearson’s correlation, Independent samples T-test and paired T-test. The significance level was considered at 0.05. Results: Before intervention, no significant difference was detected between the two groups. However, after intervention all variables were significantly different except for perceived threat. Moreover, there were significant linear relationships between Self-efficacy and all Health Belief Model components after the educational intervention in both groups (p < 0.05). Conclusion: The educational program based on the health belief model increased self-efficacy in type 2 diabetes mellitus patients.展开更多
BACKGROUND: Various sedative drugs have been proposed to control anxiety and agitation in shoulder dislocation, but none of them has been diagnosed as the best sedative and relaxant agent. The study aimed to compare t...BACKGROUND: Various sedative drugs have been proposed to control anxiety and agitation in shoulder dislocation, but none of them has been diagnosed as the best sedative and relaxant agent. The study aimed to compare the sedative effectiveness of thiopental versus midazolam in reduction of shoulder dislocation.METHODS: A randomized double-blind controlled trail was performed in 80 patients with shoulder dislocation recruited from the emergency department. Ten patients were excluded and 70 patients were enrolled in the study. Case group received intravenous thiopental 2 mg/kg+2 μg/kg fentanyl while control group received intravenous midazolam 0.1 mg/kg+2 μg/kg fentanyl. Number of times, patients and physician's satisfaction, difficulty of procedure, degree of muscle relaxation, time of sedation and complete recovery, number of patients with apnea episode, O2 saturation, patient's pain score and adverse events were all recorded.RESULTS: Muscular tone had significant difference between the two groups(P-value=0.014) and thiopental was more muscle relaxant than midazolam. Replacement of shoulder dislocation in thiopental group was easier than midazolam group(P-value=0.043). There was no need to use multiple methods of reduction in either group. Before drug infusion the mean±SD VAS scores were 8.37±2.21 in the midazolam group(A) and 8.94±1.78 in the thiopental group(B); mean difference 0.57, 95% CI= –0.38 to 1.52. After completion of the procedure, the mean±SD VAS scores in group(A) and(B) were 3.20±1.30 vs. 3.65±1.30; mean difference –0.45, 95% CI= –1.07 to 0.16.CONCLUSION: Thiopental might be more effective and relaxant than midazolam for reduction of shoulder dislocation.展开更多
Multi-level inverters(MLIs)have become popular in different applications such as industrial power control systems and distributed generations.There are different forms of MLIs.The cascaded MLIs(CMLIs)have some special...Multi-level inverters(MLIs)have become popular in different applications such as industrial power control systems and distributed generations.There are different forms of MLIs.The cascaded MLIs(CMLIs)have some special advantages among them such as more different output voltage levels using the same number of components and higher power quality.In this paper,a 27-level inverter switching algorithm considering total harmonic distortion(THD)minimization is investigated.Switching angles of the inverter switches are achieved by minimizing a THD-based objective function.In order to minimize the THD-based objective function,the hyper-spherical search(HSS)algorithm,as a novel optimization algorithm,is improved and the results of improved HSS(IHSS)are compared with HSS algorithm and other five evolutionary algorithms to show the advantages of IHSS algorithm.展开更多
Mobile power meters allow for cyclists to monitor power output （PO） during training and competition. The Garrnin Vector power meter （VPM） measures PO at the pedal compared to the crank and has been tested in only ...Mobile power meters allow for cyclists to monitor power output （PO） during training and competition. The Garrnin Vector power meter （VPM） measures PO at the pedal compared to the crank and has been tested in only a few limited studies. The purpose of this study was to determine the validity and reproducibility of the VPM by comparing it to the SRM. The VPM validity was tested by （1） a submaximal incremental test, （2） submaximal constant power test, （3） sprint test, and （4） a field test. The reliability of the VPM was tested by repeating the laboratory tests 10 times over a 6 week span. Significant differences （P = 0.046） were found between the mean POSRM （178 ± 1.8 W） and POVPM （163.5 ± 14.7 W） for the submaximal constant-power test. No significant differences were found between the POMAX SRM and the POMAx VPM. The reproducibility of the VPM was lower than the SRM （CV = 8.52 ±4.0 vs 3.48 ± 1.9, 10.66% vs 5.50%, and 67.7% vs 55.3% for the submaximal incremental test, submaximal constant-power test, and field test respectively）. The POVPM appears to underestimate the POSRM and is less valid and reliable across various cycling efforts.展开更多
文摘We systematically reviewed the clinical trials which recruited antioxidants in the therapy of pancreatitis and evaluated whether antioxidants improve the outcome of patients with pancreatitis. Electronic bibliographic databases were searched for any studies which investigated the use of antioxidants in the management of acute pancreatitis （AP） or chronic pancreatitis （CP） and in the prevention of post-endoscopic retrograde cholangio-pancreatography （post-ERCP） pancreatitis （PEP） up to February 2009. Twenty-two randomized, placebo-controlled, clinical trials met our criteria and were included in the review. Except for a cocktail of antioxidants which showed improvement in outcomes in three different clinical trials, the results of the administration of other antioxidants in both AP and CP clinical trials were incongruent and heterogeneous.Furthermore, antioxidant therapy including allopurinol and N-acetylcysteine failed to prevent the onset of PEP in almost all trials. In conclusion, the present data do not support a benefit of antioxidant therapy alone or in combination with conventional therapy in the management of AP, CP or PER Further double blind, randomized, placebo-controlled clinical trials with large sample size need to be conducted.
基金Supported by Stem Cell Research Center of Golestan University of Medical Sciences(No.110480).
文摘AIM:To investigate the impact of niosome nanoparticles carrying umbelliprenin(UMB),an anti-angiogenic and anti-inflammatory plant compound,on the expression of vascular endothelial growth factor(VEGF-A)and connective tissue growth factor(CTGF)genes in a human retinal pigment epithelium(RPE)-like retina-derived cell line.METHODS:UMB-containing niosomes were created,optimized,and characterized.RPE-like cells were treated with free UMB and UMB-containing niosomes.The IC_(50)values of the treatments were determined using an MTT assay.Gene expression of VEGF-A and CTGF was evaluated using real-time polymerase chain reaction after RNA extraction and cDNA synthesis.Niosomes’characteristics,including drug entrapment efficiency,size,dispersion index,and zeta potential were assessed.Free UMB had an IC_(50)of 96.2μg/mL,while UMB-containing niosomes had an IC_(50)of 25μg/mL.RESULTS:Treatment with UMB-containing niosomes and free UMB resulted in a significant reduction in VEGF-A expression compared to control cells(P=0.001).Additionally,UMB-containing niosomes demonstrated a significant reduction in CTGF expression compared to control cells(P=0.05).However,there was no significant reduction in the expression of both genes in cells treated with free UMB.CONCLUSION:Both free UMB and niosome-encapsulated UMB inhibits VEGF-A and CTGF genes expression.However,the latter demonstrates significantly greater efficacy,potentially due to the lower UMB dosage and gradual delivery.These findings have implications for anti-angiogenesis therapeutic approaches targeting age-related macular degeneration.
文摘Formany years,researchers have explored power allocation(PA)algorithms driven bymodels in wireless networks where multiple-user communications with interference are present.Nowadays,data-driven machine learning methods have become quite popular in analyzing wireless communication systems,which among them deep reinforcement learning(DRL)has a significant role in solving optimization issues under certain constraints.To this purpose,in this paper,we investigate the PA problem in a k-user multiple access channels(MAC),where k transmitters(e.g.,mobile users)aim to send an independent message to a common receiver(e.g.,base station)through wireless channels.To this end,we first train the deep Q network(DQN)with a deep Q learning(DQL)algorithm over the simulation environment,utilizing offline learning.Then,the DQN will be used with the real data in the online training method for the PA issue by maximizing the sumrate subjected to the source power.Finally,the simulation results indicate that our proposedDQNmethod provides better performance in terms of the sumrate compared with the available DQL training approaches such as fractional programming(FP)and weighted minimum mean squared error(WMMSE).Additionally,by considering different user densities,we show that our proposed DQN outperforms benchmark algorithms,thereby,a good generalization ability is verified over wireless multi-user communication systems.
基金This study was financially supported by Tabriz University of Medical Sciences(ethic number.TBZMED.REC.1394.968)
文摘Objectives: This study aimed to identify coping strategies used by family caregivers of patients with schizophrenia and their determinants.Methods: This was a descriptive correlational study.Participants were 225 family caregivers of patients with schizophrenia who were referred to the psychiatric clinic at one large teaching referral hospital in Iran.They were selected through purposive sampling method.Data collection tools were demographic and clinical data form,the Zarit Burden Interview (ZBI) and the Family Coping Questionnaire (FCQ).Results: The score of caregiver burden was 65.14 ± 9.17.Of 225 family caregivers,23.11% used an avoiding coping strategy.There was a significant relationship between caregiver burden and coping strategies (P < 0.001).The regression model showed that adaptive coping strategies were significantly associated with some demographic characteristics including age,education level,gender,employment status,losing the job because of caregiving responsibilities,perceived income adequacy,duration of illness,duration of caregiving and caregiver burden (P < 0.05).Conclusion: Family caregivers of patients with schizophrenia experience a high level of burden,which can put them at risk of using maladaptive coping strategies.Mental health professionals should plan programs that support both family caregivers and patients in clinical and community settings.
基金Supported by Golestan University of Medical Sciences(No.111294).
文摘AIM:To evaluate the effect of auraptene(AUR)treatment in forms of free and encapsulated in niosome nanoparticles by investigating the mRNA expression level of vascular endothelium growth factor(VEGF)-A and platelet-derived growth factors(PDGFs)in human retinal pigment epithelium(RPE)cell line.METHODS:Niosome nanocarriers were produced using two surfactants Span 60 and Tween 80.RPE cell line was treated with both free AUR and niosome-encapsulated.Optimum dosage of treatments was calculated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay.Expression of VEGF-A and PDGF-A,PDGF-B,PDGF-C,PDGF-D genes was measured after total RNA extraction and cDNA synthesis,using real-time polymerase chain reaction(RT-PCR).RESULTS:The highest entrapment efficiency(EE)was achieved by Span 60:cholesterol(1:1)with 64.3%.The half maximal inhibitory concentration(IC50)of free and niosome-encapsulated AUR were 38.5 and 27.78µg/mL,respectively.Release study revealed that niosomal AUR had more gradual delivery to the cells.RT-PCR results showed reduced expression levels of VEGF-A,PDGF-A,PDGF-B,PDGF-C,and PDGF-D after treatment with both free and niosomal AUR.CONCLUSION:Niosomal formulation of Span 60:cholesterol(1:1)is an effective drug delivery approach to transfer AUR to RPE cells.VEGF-A,PDGF-A,PDGF-B,PDGF-C,and PDGF-D are four angiogenic factors,inhibiting which by niosomal AUR may be effective in age-related macular degeneration.
文摘In this paper, a polymer electro-optic modulator is designed and simulated using the full vectorial finite element method. First order edge elements are used in finite element implementation, and the finite element technique is used to obtain modulator response thoroughly. From the numerical analysis, frequency dispersions of modulator's important parameters, such as microwave effective index nm , microwave characteristic impedance ZC and microwave loss a, are extracted. Our design exhibits electrical bandwidth of 260 GHz and drive voltage of about 2.8 V.cm in this frequency.
文摘The purpose of active distribution networks(ADNs)is to provide effective control approaches for enhancing the operation of distribution networks(DNs)and greater accommodation of distributed generation(DG)sources.With the integration of DG sources into DNs,several operational problems have drawn attention such as overvoltage and power flow alteration issues.These problems can be dealt with by utilizing distribution network reconfiguration(DNR)and soft open points(SOPs).An SOP is a power electronic device capable of accurately controlling active and reactive power flows.Another significant aspect often overlooked is the coordination of protection devices needed to keep the network safe from damage.When implementing DNR and SOPs in real DNs,protection constraints must be considered.This paper presents an ADN reconfiguration approach that includes DG sources,SOPs,and protection devices.This approach selects the ideal configuration,DG output,and SOP placement and control by employing particle swarm optimization(PSO)to minimize power loss while ensuring the correct operation of protection devices under normal and fault conditions.The proposed approach explicitly formulates constraints on network operation,protection coordination,DG size,and SOP size.Finally,the proposed approach is evaluated using the standard IEEE 33-bus and IEEE 69-bus networks to demonstrate the validity.
文摘BACKGROUND:Numerous drugs have been proposed to alleviate pain in patients with biliary colic,especially opioids,but still there is a tendency to use less narcotics because of their side effects and the unwillingness of some patients.The present study aimed to compare the analgesic effect of paracetamol combined with low-dose morphine versus morphine alone in patients with biliary colic.METHODS:A randomized double-blind controlled trial was performed in 98 patients with biliary colic,recruited from two emergency departments from August 2012 to August 2013.Eleven patients were excluded and the remaining were randomized into two groups:group A received 0.05mg/kg morphine+1 000 mg paracetamol in 100 m L normal saline and group B received 0.1 mg/kg morphine+normal saline(100 m L)as placebo.Pain scores were recorded using visual analogue scale(VAS)at baseline and 15 and 30 minutes after drug administration.Adverse effects and the need for rescue medication(0.75 g/kg intravenous fentanyl)were also reported within 60 minutes of drug administration.RESULTS:Before the infusion,the mean±SD VAS scores were 8.73±1.57 in group A and8.53±1.99 in group B.At 15 minutes after drug administration,the mean±SD VAS scores were2.16±1.90 in group A vs.2.51±1.86 in group B;mean difference was–0.35,and 95%CI–1.15 to 0.45(P=0.38).At 30 minutes the mean±SD VAS scores were 1.66±1.59 in group A vs.2.14±1.79 in group B;mean difference was–0.48,and 95%CI–1.20 to 0.24(P=0.19).The mean pain scores in the two groups at 15 and 30 minutes demonstrated no significant difference.CONCLUSION:Paracetamol combined with low-dose morphine may be effective for pain management in patients with biliary colic.
文摘BACKGROUND: Sleep deprivation resulting from night shifts, is a major cause of burnout among physicians. Exogenous melatonin may improve sleep quality in night-shift workers. The study aims to compare the effectiveness of melatonin versus placebo on sleep effi ciency in emergency medicine(EM) residents. METHODS: A randomized, double-blind, replicated crossover trial was performed on EM residents. This study consisted of 4 phases within a month with intervention periods of 2 nights and washouts of 6 days. In our study, EM residents had nine-hour shifts on 6 consecutive days, 2 mornings, 2 evenings and 2 nights and then 2 days off. At the end of shifts' cycle, 24 EM residents were given 3 mg melatonin or placebo(12 in each arm of the study) for 2 consecutive nights after the second night shift with crossover to the other arm after a six-day off drug. This crossover intervention was repeated for two more another time. Finally, we created 48 cases and comparisons in each arm. Different items related to sleep quality were assessed and compared both within the same group and between the two groups. RESULTS: In the melatonin group, daytime sleepiness(calculated by Karolinska Sleep Scale) had a signifi cant reduction after taking the second dose of drug(P=0.003) but the same result was not observed when comparing the 2 groups. Mood status(calculated by Profile of Mood States) showed no remarkable difference between the 2 groups. CONCLUSION: Melatonin might have a limited benefi t on sleep quality in EM residents working night shifts.
文摘BACKGROUND: Assessing and evaluating mental health status can provide educational planners valuable information to predict the quality of physicians' performance at work. These data can help physicians to practice in the most desired way. The study aimed to evaluate factors affecting psychological morbidity in Iranian emergency medicine practitioners at educational hospitals of Tehran.METHODS: In this cross sectional study 204 participants(emergency medicine residents and specialists) from educational hospitals of Tehran were recruited and their psychological morbidity was assessed by using a 28-question Goldberg General Health Questionnaire(GHQ-28). Somatization, anxiety and sleep disorders, social dysfunction and depression were evaluated among practitioners and compared to demographic and job related variables.RESULTS: Two hundreds and four participants consisting of 146(71.6%) males and 58(28.4%) females were evaluated. Of all participants, 55(27%) were single and 149(73%) were married. Most of our participants(40.2%) were between 30–35 years old. By using GHQ-28, 129(63.2%) were recognized as normal and 75(36.8%) suffered some mental health disorders. There was a signifi cant gender difference between normal practitioners and practitioners with disorder(P=0.02) while marital status had no significant difference(P=0.2). Only 19(9.3%) declared having some major mental health issue in the previous month.CONCLUSION: Females encountered more mental health disorders than male(P=0.02) and the most common disorder observed was somatization(P=0.006).
文摘Accurate estimation of sediment load or transport rate is very important to a wide range of water resources projects. This study was undertaken to determine the most appropriate model to predict suspended load in the Chelehay Watershed, northeast of Iran. In total, 59 data series were collected from four gravel bed-rivers and a sand bed river and two depth integrating suspended load samplers to evaluate nine suspended load formulas and feed forward backpropagation Artificial Neural Network （ANN） structures. Although the Chang formula with higher correlation coefficient （r = 0.69） and lower Root Mean Square Error （RMSE = 0.013） is the best suspended load predictor among the nine studied formulas, the ANN models significantly outperform traditional suspended load formulas and show their superior performance for all statistical parameters. Among different ANN structures two models inclu- ding 4 inputs, 4 hidden and one output neurons, and 4 inputs, 4 and one hidden and one output neurons provide the best simulation with the RMSE values of 0.0009 and 0.001, respectively.
文摘BACKGROUND: Rapid and effective pain relief in acute traumatic limb injuries(ATLI) is one of the most important roles of emergency physicians. In these situations, opioid addiction is an important concern because of the dependency on opioids. The study aims to compare the effectiveness of intravenous(IV) fentanyl versus morphine in reducing pain in patients with opioid addiction who suffered from ATLI.METHODS: In this double-blind randomized clinical trial, 320 patients with ATLI, who presented to the emergency department(ED) from February 2016 to April 2016, were randomly divided into two groups. One group(160 patients) received 0.1 mg/kg IV morphine. The other group(160 patients) received 1 mcg/kg IV fentanyl. Patients' demographic data, pain score at specif ic intervals, vital signs, side effects, satisfaction and the need for rescue analgesia were recorded.RESULTS: Eight patients in the morphine group and five patients in the fentanyl group were excluded. Pain score in the fentanyl group had a significant decrease at 5-minute follow-up(P value=0.00). However, at 10, 30, and 60-minute follow-ups no signifi cant differences were observed between the two groups in terms of pain score reduction. The rescue analgesia was required in 12(7.7%) patients in the fentanyl group and in 48(31.6%) patients in the morphine group(P value=0.00). No signifi cant difference was observed regarding side effects, vital signs and patients' satisfaction between the two groups.CONCLUSION: Fentanyl might be an effective and safe drug in opioid addicts suffering from ATLI.
文摘In this paper, a polymer electro-optic mod- ulator has been designed and optimized using the full vectorial finite element method. For this purpose, the effects of magnesium oxide （MgO） and down cladding thicknesses, distance between two ground electrodes, hot electrode and modulator widths modulator on the key modulator parameters, such as microwave effective index r/m, the characteristic impedance Zc and the microwave losses a are presented. After selecting optimal dimensions of polymer electro-optic modulator, frequency dependent aforementioned parameters and the half-wave voltage- length product （VπL） parameter of polymer electro-optic modulator are extracted and as a consequence, an optimized design is reported. Finally, the optical and electrical modulation responses of polymer electro-optic modulator are calculated. The optimized polymer electro- optic modulator exhibits 3-dB electrical bandwidth of 260 GHz and VπL about 2.8 V- cm in this frequency.
基金The authors wish to sincerely acknowledge the High Technology Industries Center, Iranian Ministry of Mines and Metals for financial support of the research work.
文摘Al-20Si-5Fe melt was rapidly solidified into particles and ribbons and then consolidated to near full density by hot pressing at 400℃/250 MPa/1 h. According to the eutectic-growth and dendritic-growth velocity models, the solidification front velocity and the amount of undercooling were estimated for the particles with different sizes. Values of 0.43-1.2 cm/s and 15-28 K were obtained. The secondary dendrite arm spacing revealed a cooling rate of 6 × 10^5 K/s for the particles with an average size of 20 μm. Solidification models for the ribbons yielded a cooling rate of 5 × 10^7 K/s. As a result of the higher cooling rate, the melt-spun ribbons exhibited considerable microstructural refinement and modification. The size of the primary silicon decreased from approximately 1μm to 30 nm while the formation of iron-containing intermetallic compounds was suppressed. Supersaturation of the aluminum matrix in an amount of-7 at.% Si was noticed from the XRD patterns During the hot consolidation process, coarsening of the primary silicon particles and precipitation of β-Al5FeSi phase were observed. Evaluation of the compressive strength and hardness of the alloy indicated an improvement in mechanical properties due to the microstructural modification.
文摘Graphene materials have drawn tremendous attention in recent years.The formation of holes and pores on graphene sheets can provide transfer channels and facilitate the ion/electron transport kinetics.In this study,graphene nanosheets were prepared electrochemically,and then,they were used as the starting material for the preparation of holey graphene(HG)through the KOH activation process.The weight ratio of initial electrochemically exfoliated graphene(EEG)to KOH was optimized according to the morphological features,BET surface area examination,graphene number of layers calculated from XRD patterns,and the ID/IG ratio obtained from Raman analysis.Results showed that increasing the KOH amount led to the achievement of higher values of ID/IG and surface area and less re-stacking of graphene sheets which occurs because of the heat treatment process.The environmental burdens of the production routes for the preparation of EEG and HG were investigated by cradle-to-gate life cycle assessment(LCA).The LCA results of EEG production indicated that electricity with the contributions of 94%,91%,82%,and 75%of the total impact in four environmental categories,including fossil fuel depletion,ozone depletion,global warming,and smog was the main environmental weakness.In the pore generation process,KOH was recognized as the biggest contributor(about 51%to 83%of the total impact)in six impact categories,including ozone depletion,non-carcinogenics,smog,global warming,carcinogenics,and eutrophication which could be attributed to its high consumption amount(21.9 kg).This work offers environmental considerations for the development of sustainable graphene materials.
文摘Background: Patient self-efficacy is one of the most important factors in treating and overcoming disease. Objective: The aim of this study was to evaluate the effect of an educational program based on the health belief model on self-efficacy among patients with type 2 diabetes referred to the Iranian Diabetes Association in 2014. Method: A randomized controlled clinical trial was conducted. Eighty patients with type 2 diabetes were selected randomly by the double block sample method. They were then divided into two groups of intervention and control (40 patients in each group) by random allocation. Data were collected by a questionnaire based on the Health Belief Model and self-efficacy. The data were gathered two months after the educational program was held. The educational program was designed on the basis of data collected in the pre-test phase. Then, the educational program was executed for the intervention group in 8 sessions (each 30 minutes) using lectures and an educational booklet. Data analysis was done with Chi-square Test, Pearson’s correlation, Independent samples T-test and paired T-test. The significance level was considered at 0.05. Results: Before intervention, no significant difference was detected between the two groups. However, after intervention all variables were significantly different except for perceived threat. Moreover, there were significant linear relationships between Self-efficacy and all Health Belief Model components after the educational intervention in both groups (p < 0.05). Conclusion: The educational program based on the health belief model increased self-efficacy in type 2 diabetes mellitus patients.
文摘BACKGROUND: Various sedative drugs have been proposed to control anxiety and agitation in shoulder dislocation, but none of them has been diagnosed as the best sedative and relaxant agent. The study aimed to compare the sedative effectiveness of thiopental versus midazolam in reduction of shoulder dislocation.METHODS: A randomized double-blind controlled trail was performed in 80 patients with shoulder dislocation recruited from the emergency department. Ten patients were excluded and 70 patients were enrolled in the study. Case group received intravenous thiopental 2 mg/kg+2 μg/kg fentanyl while control group received intravenous midazolam 0.1 mg/kg+2 μg/kg fentanyl. Number of times, patients and physician's satisfaction, difficulty of procedure, degree of muscle relaxation, time of sedation and complete recovery, number of patients with apnea episode, O2 saturation, patient's pain score and adverse events were all recorded.RESULTS: Muscular tone had significant difference between the two groups(P-value=0.014) and thiopental was more muscle relaxant than midazolam. Replacement of shoulder dislocation in thiopental group was easier than midazolam group(P-value=0.043). There was no need to use multiple methods of reduction in either group. Before drug infusion the mean±SD VAS scores were 8.37±2.21 in the midazolam group(A) and 8.94±1.78 in the thiopental group(B); mean difference 0.57, 95% CI= –0.38 to 1.52. After completion of the procedure, the mean±SD VAS scores in group(A) and(B) were 3.20±1.30 vs. 3.65±1.30; mean difference –0.45, 95% CI= –1.07 to 0.16.CONCLUSION: Thiopental might be more effective and relaxant than midazolam for reduction of shoulder dislocation.
文摘Multi-level inverters(MLIs)have become popular in different applications such as industrial power control systems and distributed generations.There are different forms of MLIs.The cascaded MLIs(CMLIs)have some special advantages among them such as more different output voltage levels using the same number of components and higher power quality.In this paper,a 27-level inverter switching algorithm considering total harmonic distortion(THD)minimization is investigated.Switching angles of the inverter switches are achieved by minimizing a THD-based objective function.In order to minimize the THD-based objective function,the hyper-spherical search(HSS)algorithm,as a novel optimization algorithm,is improved and the results of improved HSS(IHSS)are compared with HSS algorithm and other five evolutionary algorithms to show the advantages of IHSS algorithm.
文摘Mobile power meters allow for cyclists to monitor power output （PO） during training and competition. The Garrnin Vector power meter （VPM） measures PO at the pedal compared to the crank and has been tested in only a few limited studies. The purpose of this study was to determine the validity and reproducibility of the VPM by comparing it to the SRM. The VPM validity was tested by （1） a submaximal incremental test, （2） submaximal constant power test, （3） sprint test, and （4） a field test. The reliability of the VPM was tested by repeating the laboratory tests 10 times over a 6 week span. Significant differences （P = 0.046） were found between the mean POSRM （178 ± 1.8 W） and POVPM （163.5 ± 14.7 W） for the submaximal constant-power test. No significant differences were found between the POMAX SRM and the POMAx VPM. The reproducibility of the VPM was lower than the SRM （CV = 8.52 ±4.0 vs 3.48 ± 1.9, 10.66% vs 5.50%, and 67.7% vs 55.3% for the submaximal incremental test, submaximal constant-power test, and field test respectively）. The POVPM appears to underestimate the POSRM and is less valid and reliable across various cycling efforts.
