Employing a three-stage procedure to develop a sizing system for medical gloves

There is a need for gloves that are designed based on the dimensions of the hand of each society because the proper size is a key factor that affects performance. This study aimed to design and develop a glove-sizing system for Iranian healthcare workers using anthropometric data. This study was conducted on a sample including 540 healthcare workers across Iran classified by ethnicity and gender. Thirty-three dimensions were measured as the anthropometric data. Principal Component Analysis (PCA) and clustering analysis were used to create classifications for glove sizes. The most effective dimensions in defining the hand sizes of Iranian healthcare workers were middle finger length and the handbreadth. The designed six-size system covered 94% of the sample. This system can be used to design suitable gloves for Iranians. The sizes presented can be used to compare size differences in different communities. Practitioner summary: In this study, an attempt was made to design a sizing system with maximum coverage for medical gloves using statistical analysis methods and hand anthropometric dimensions of Iranian healthcare workers. The method of this study can be used in other communities as well for improving sizing systems.Abbreviations: PCA: Principal Component Analysis; GSS: Glove Sizing Systems; TEM: Technical error of measurement; R: Reliability coefficient; KMO: The Kaiser-Meyer-Olkin; PC1: The first principal component; PC2: The second principal component; FCMC: Fuzzy c-means clustering; XS: Very small; S: Small; SM: Medium small; LM: Medium large; L: Large; Xl: Very large.

Design and psychometric analysis of the safety harness usability and comfort assessment tool (SH UCAT)

Purpose

The present study aimed to design a quantitative tool to evaluate the comfort and usability of working at height safety harnesses.

Methods

This cross-sectional study was conducted in both qualitative and quantitative sections in 2022. The research steps included field interviews, an expert panel, and compiling the questionnaires for assessing the comfort and usability of the harness. The items of tools were designed based on the qualitative part of the research and review of the literature. The face and content validity of the instrument were assessed. Its reliability was also evaluated using the test-retest method.

Results

Two tools were developed including a comfort questionnaire with 13 questions and a usability questionnaire with 10 questions. The Cronbach's alpha coefficients of these instruments were 0.83 and 0.79, respectively. Additionally, the content and face validity indices were 0.97 and 3.89 for the comfort questionnaire and 0.991 and 4 for the usability questionnaire, respectively.

Conclusions

The designed tools showed appropriate validity and reliability and could be used to evaluate the comfort and usability of safety harnesses. On the other hand, the criteria used in the designed tools could be employed in user-centered harness designs.

Analysis of the research subjects and hot topics of occupational diseases through the Web of Science from 1975 to 2021

A variety of studies have been conducted in Occupational diseases (ODs) and this makes it difficult for researchers to identify new areas of study. Therefore, the present study was conducted by examining Web of Science data to identify hot topics and research topics on ODs. This is a scientometric study performed using CiteSpace and Gephi software for statistical analysis. The published article in Web of Sciences was searched using the keywords "Occupational disease^*" OR "Occupational illness^*" OR "Industrial disease^*" OR "Industrial illness^*". Finally, the countries and institutions and their cooperation, the most important and main topics discussed, and the path of future progress in ODs was analyzed. Preliminary results of the study show that out of 5,947 articles. The results of important journals showed that the American Journal of Industrial Medicine with 233 articles (6.02%), Oxford Occupational Medicine, and International Archives of Occupational and Environmental Health with 86 (2.22%), and 83 (2.15%), respectively. The two producing countries are the United States and Germany, which published 628 and 419 articles, respectively. The results of hot topics showed occupational exposures, epidemiology, mental health, and respiratory diseases were the most important keywords used in these 45 years. It can be concluded that Germany, with its current development trend in the coming years, will surpass the United States based on the number of articles and gain the first rank. Also, future studies can be conducted on respiratory diseases as the most important ODs and health care work as the most important job during the past years.

The global incidence and associated factors of surgical gloves perforation: A systematic review and meta-analysis

BACKGROUND

Surgeon's hands are exposed to a range of chemical and physical stressors that influence the integrity of gloves. Thus, glove perforation facilitates pathogen transmission through the holes. Numerous studies have shown that glove perforation is of great importance, but there is still no complete consensus.

OBJECTIVE

This study aimed to investigate the safety conditions of surgical gloves based on the incidence of glove perforation among surgical teams.

METHODS

A literature review was conducted by searching PubMed, Embase, Scopus, ISI, and ProQuest databases. The incidence of glove perforation was reviewed in eight categories. A total of 580 articles were found in the initial search.

RESULTS

109 articles containing 130 datasets were analyzed. The overall incidence of glove perforation was 14.44 %. Surgeons had the highest incidence of glove perforation (23.09 %). An increase in the duration of surgery increased the odds of perforation. It was found that 68.58% of the glove perforations were not identified by practitioners.

CONCLUSION

Despite major advances in the design of surgical gloves, the issue of safety and integrity of gloves has not improved. Due to the high incidence of surgical glove perforations, most of which had not been identified, it is imperative to consider strategies to minimize the incidence of perforation. The results of the present study can be used to integrate information related to the rate of perforation of surgical gloves in different surgeries.

Does Size Affect the Rate of Perforation? A Cross-sectional Study of Medical Gloves

OBJECTIVES

Healthcare workers often have unnoticed minor abrasions on their hands, putting them at risk of contracting infectious diseases from patients, if the integrity of the medical gloves is compromised. This study aimed to compare the rate and location of glove perforation between well-fitted and ill-fitted gloves.

METHODS

The participants of this cross-sectional study were 45 midwives in the maternity ward of a hospital in Shiraz city, Iran. A total of nine pairs of medical gloves including three pairs of fit size, three pairs of gloves with one size smaller (tight), and three pairs of gloves with one size larger (loose) were given to subjects, and asked them to use the gloves during episiotomy repair operations. After completing the task, all gloves were collected safely and gloves perforation was investigated based on water test (NF EN 455-1).

RESULTS

The perforation rate of the fit, tight, and loose medical gloves was 20, 37.78, and 34.81%, respectively. The results showed a significant difference between glove perforation of different glove sizes (P < 0.05). In general, there was a significant difference between the perforation rate of the fit glove and ill-fitted gloves (P = 0.013).

CONCLUSIONS

Wearing the wrong size gloves may increase the glove perforation rate. Providing a wide range of glove sizes by the hospital management, and choosing the best glove size can be very effective in reducing the glove perforation and increasing safety for healthcare workers and patients.

Artificial Neural Networks (ANNs) and Partial Least Squares (PLS) Regression in the Quantitative Analysis of Respirable Crystalline Silica by Fourier-Transform Infrared Spectroscopy (FTIR)

Respirable crystalline silica (RCS) overexposure can lead to the development of silicosis which is a chronic, irreversible, potentially fatal respiratory disease. The most significant prerequisite for any silica exposure control plan is an accurate occupational exposure assessment. The results of crystalline silica analysis are often affected by other mineral interferences and are influenced by an analyst's knowledge of mineralogy to accurately interpret infrared spectra and correct matrix interferences. Partial least squares (PLS) and artificial neural networks (ANNs) are two multivariate calibration methods to overcome the problem of spectral interferences without the need for an analyst intervention. The performance of these two methods in quantitative analysis of quartz in the presence of mineral interferences was evaluated and compared in this study. Fifty mixtures with different crystalline silica content ratios were prepared by mixing quartz with four common mineral interferences including kaolinite, albite, muscovite, and amorphous silica. Fourier-transform infrared spectra of the mixtures were split into training and test datasets. The optimal architecture of the ANN model was achieved using a two-level full factorial design experiment and data were modeled using ANN and PLS regression analysis. Root mean squared error of prediction values of 1.69 and 6.12 µg quartz for ANN and PLS models, respectively, revealed the fact that the both models performed very well in quantitative analysis of quartz in the presence of mineral interferences, with a better relative performance of the ANN model which can be related to the inherent nonlinear predictive ability of ANNs. Given the excellent predictive ability of the ANN model which can deal with a completely overlapped peak without any need of user's intervention, it is recommended that the ANN model be optimized in future studies and utilized for reliable and rapid on-field assessment of RCS exposure.

Nurses' uncertainty about medical gloves safety during the COVID-19 pandemic

Background

Nurses, as the largest group of health professionals, are at the frontline of the healthcare system in response to COVID-19 epidemic. This study aimed to evaluate the nurses’ certainty and satisfaction with medical gloves when exposed to coronavirus in Fars province, south of Iran.

Methods

Using convenience sampling, 400 hospital nurses during the COVID-19 outbreak were selected from eight hospitals of Shiraz University of Medical Sciences (SUMS). A questionnaire about glove reliability, including protection in tasks, durability, integrity and tear resistance, feeling fearful, and focusing on duties, and the nurses’ anxiety regarding their infection with coronavirus was distributed to the selected nurses to complete. 375 questionnaires were completed (response rate of 93.75%). Among the participants, 180 (48%) were in the corona section and 195 (52%) were hardly possible to have contact with coronavirus pneumonia patients.

Results

The mean score (SD) of anxiety about infection with COVID-19 for nurses in the COVID-19 section and those in the non-COVID-19 section were 6.08 (2.8) and 4.56 (2.58), respectively (p < 0.05). The mean duration of gloves usage in a day was almost similar in the two groups (about 5 h), but the number of glove replacements was significantly higher among the nurses in the corona section (6 times) compared to those in the non-corona section (3 times). The two groups were also significantly different regarding glove protection in daily tasks and glove durability.

Conclusion

The nurses in the corona section had more concerns about medical gloves as a type of personal protective equipment. In addition to health education on controlling and preventing the spread of diseases, raising awareness about the reliability of personal protective equipment can improve nurses’ performance.

Fuzzy Logic Modeling of Factors Affecting Musculoskeletal Disorders in a Steel Factory in Iran: A Cross-Sectional Study

OBJECTIVES

The aim of this study was to model associated factors affecting musculoskeletal disorders (MSDs), using fuzzy logic in a steel factory in Iran.

METHODS

A cross-sectional study was conducted on steel industry workers. A 6-part questionnaire was used, consisting of demographic characteristics, occupational stress, work-family conflict, general health, occupational postures, and Nordic Musculoskeletal Questionnaire. Pearson correlation was used for statistical analysis.

RESULTS

The prevalence of MSDs for 270 participants in the studied factory was 94.8%. Job stress, work-family conflict, general health, and work posture had a statistically significant relationship with MSDs (P < .05). The fuzzy model demonstrated 23.8% predictability for the actual data of the study. The defuzzification data had significant correlation with real data of MSDs.

CONCLUSIONS

The results of this study provided a new perspective about associated factors affecting MSDs and demonstrate that fuzzy logic can be used as a possible tool for evaluating MSDs.

Comparison of the Effect of Traffic Park-Based and School-Based Educational Interventions on Safe Road Crossing in Yazd Elementary School Students

INTRODUCTION

Traffic accidents are one of the most important health problems that cause many deaths every year. Scientific-practical interventions are needed to prevent traffic accidents. This study aimed to compare the effectiveness of traffic-based and school-based interventions on the safe road crossing in Yazd elementary school students.

METHODS

This interventional study was conducted on 132 students (66 males and 66 females) in two groups of school-based and traffic park-based intervention. A questionnaire was used to determine the safe crossing behavior score. Then, an educational intervention was administered to both groups. Two months after the intervention, safe crossing behavior was evaluated in both groups. Finally, the data were analyzed using SPSS software version 22.

RESULTS

In both groups, the score of safe crossing behavior was significantly increased after the intervention. The school-based group had significantly better behaviors compared to the traffic park-based group (P=0.001). There was a significant difference in the mean score of behavior between males and females and the intervention had a greater effect on female students (P=0.017).

CONCLUSION

Educational interventions and especially school-based intervention can be effective in improving the students' safe crossing behaviors.

The Medical Gloves Assessment Tool (MGAT): Developing and validating a quantitative tool for assessing the safety and ergonomic features related to medical gloves

BACKGROUND

Medical gloves play a very important role in protecting health care workers and patients. It is very important to pay attention to the safety and ergonomic properties of medical gloves in their protective function.

AIM

To develop a quantitative tool for evaluating the safety and ergonomic properties of the medical gloves.

METHODS

Five hospitals with a total of 185 health care workers participated in the research. The domains and items of the tool were developed based on an expert's panel, interviews with health care workers and a literature review. Face, content and construct validity was used for validation. Reliability was also evaluated using internal consistency.

RESULTS

The final tool included 26 items in six domains, including tactile sensation, dexterity, grip strength, fitting, reliability and hand hygiene. The Cronbach's alpha was 0.82 for the total scale.

CONCLUSION

The final tool had good validity and reliability. The findings of this study led to the development of a comprehensive standard tool that can be used to assess the ergonomic and safety status of medical gloves.

IMPLICATIONS FOR NURSING MANAGEMENT

With this tool, problems related to medical gloves can be identified among nurses, and the necessary interventions can be predicted.

Genetic Consequences of the Transatlantic Slave Trade in the Americas

According to historical records of transatlantic slavery, traders forcibly deported an estimated 12.5 million people from ports along the Atlantic coastline of Africa between the 16th and 19th centuries, with global impacts reaching to the present day, more than a century and a half after slavery's abolition. Such records have fueled a broad understanding of the forced migration from Africa to the Americas yet remain underexplored in concert with genetic data. Here, we analyzed genotype array data from 50,281 research participants, which-combined with historical shipping documents-illustrate that the current genetic landscape of the Americas is largely concordant with expectations derived from documentation of slave voyages. For instance, genetic connections between people in slave trading regions of Africa and disembarkation regions of the Americas generally mirror the proportion of individuals forcibly moved between those regions. While some discordances can be explained by additional records of deportations within the Americas, other discordances yield insights into variable survival rates and timing of arrival of enslaved people from specific regions of Africa. Furthermore, the greater contribution of African women to the gene pool compared to African men varies across the Americas, consistent with literature documenting regional differences in slavery practices. This investigation of the transatlantic slave trade, which is broad in scope in terms of both datasets and analyses, establishes genetic links between individuals in the Americas and populations across Atlantic Africa, yielding a more comprehensive understanding of the African roots of peoples of the Americas.

Using fuzzy logic approach to predict work-related musculoskeletal disorders among automotive assembly workers

Background: Musculoskeletal disorders (MSDs) are considered an important health concern, particularly in automotive assembly industries. Evaluation of the effects of all MSDs risk factors is difficult due to its multifactorial nature. In addition, the risk factors cannot be detected accurately when they are only based on individual opinions. Thus, in this study, fuzzy logic tool was used to evaluate the combined effects of all risk factors on MSDs.

Methods: This cross sectional study was conducted on 100 male workers in an automotive industry. Job satisfaction, job stress, job fatigue, and body posture were evaluated by a self-reported questionnaire. Body posture was evaluated using Rapid Entire Body Assessment (REBA). Primary data analysis on extracting the input variables of MATLAB was performed by SPSS 22, with a significant level of 0.05. T test, one-way Anova, and Pearson correlation analysis were used to extract the input variables for the fuzzy logic model. The results obtained from the Nordic questionnaire was selected as the output of the fuzzy model. Fuzzy logic assessment was performed using MATLAB software version 7.0.

Results: There were significant differences between WMSDs factors, including job fatigue, strain, working posture, and the REBA final score, and pain in all limbs of the body (p<0.05). A significant difference was also found between working posture with wrist score (p<0.05). The findings on defuzzification showed a strong correlation between real and modelling results.

Conclusion: The results showed that many factors such as posture, fatigue, and strain affect MSDs. Based on the obtained results, all categories of risk factors, including personal, psychosocial, and occupational, should be considered to predict MSDs, which can be achieved by a modeling approach.

The effect of increasing the illumination on operators' visual performance in the control-room of a combined cycle power plant

BACKGROUND

Lighting is one of the environmental factors affecting the performance of the control room operators. Therefore, the aim of this study was to compare the control room operators' visual performance in two different illumination conditions at a combined cycle power plant through field-work.

METHODS

Sixteen operators in day shift were evaluated with the Freiburg Visual Acuity test (FrACT) software at two lighting systems with different intensities. It includes the first phase with fluorescent illumination system (Power: 40 W, Color Temperature: 4000 Kelvin, Luminous Flux: 2780 Lumen and Model: Pars Shahab) and the second phase with a combined illumination system includes fluorescent and LED (Power: 48 W, Color Temperature: 4000 Kelvin, Luminous Flux: 5400 Lumen and Model: Mazinoor).

RESULTS

Based on the results, visual performance index and visual acuity significantly increased after the intervention (p < 0.001). As to contrast, more lighting significantly reduced the percentage of recognized contrast (p < 0.001) and increased the contrast performance index (p < 0.001).

CONCLUSIONS

The results of this study showed that increasing the intensity of light from the values below the allowable limit to the values above the allowable limit would increase the visual indicators in individuals.

Comparing the Effectiveness of Three Ergonomic Risk Assessment Methods-RULA, LUBA, and NERPA-to Predict the Upper Extremity Musculoskeletal Disorders

Background:

Musculoskeletal disorders are a major problem in all jobs. Several methods are available for assessing the exposure to risk factors associated with musculoskeletal disorders. This study is aimed at comparing three different ergonomic risk assessment methods—rapid upper limb assessment (RULA), loading on the upper body assessment (LUBA), and new ergonomic posture assessment (NERPA) method—to predict upper extremity musculoskeletal disorders.

Materials and Methods:

The study was conducted on 210 workers from three different industries including pharmaceutical, automotive, and assembly in the Isfahan province. A Nordic questionnaire was used for determining the levels of musculoskeletal disorders. Then, selected postures were evaluated with RULA, LUBA, and NERPA methods. Finally, data were analyzed with Kolmogorov–Smirnov test to check the normality distribution of data, Spearman's correlation test to investigate the correlation between the assessed levels with musculoskeletal disorders, and Wilcoxon test to identify significant differences between the values with SPSS version 16.

Results:

Wilcoxon test revealed a significant difference between the values related to NERPA and RULA (P < 0.001), whereas no significant relation between LUBA and RULA was shown by this test (P = 0.914). The correlation coefficients of the musculoskeletal disorders' level with RULA level, NERPA level, and LUBA level were 0.74, 0.73, and 0.69, respectively.

Conclusion:

Low-risk levels in NERPA, medium-risk levels in LUBA, and high-risk levels in RULA are evaluated better. The results showed that RULA was the best method for assessing musculoskeletal disorders among the three methods.

Influence of oxygen content of the certain types of biodiesels on particulate oxidative potential

Oxidative potential (OP) is related to the organic phase, specifically to its oxygenated organic fraction (OOA). Furthermore, the oxygen content of fuel molecules has significant influence on particulate OP. Thus, this study aimed to explore the actual dependency of the OOA and ROS to the oxygen content of the fuel. In order to reach the goal, different biodiesels blends, with various ranges of oxygen content; have been employed. The compact time of flight aerosol mass spectrometer (c-ToF AMS) enabled better identification of OOA. ROS monitored by using two assays: DTT and BPEA-nit. Despite emitting lower mass, both assays agreed that oxygen content of a biodiesel is directly correlated with its OOA, and highly related to its OP. Hence, the more oxygen included in the considered biodiesels, the higher the OP of PM emissions. This highlights the importance of taking oxygen content into account while assessing emissions from new fuel types, which is relevant from a health effects standpoint.

Comparison of two different doses of dexmedetomidine in attenuating cardiovascular responses during laryngoscopy and endotracheal intubation: A double blind, randomized, clinical trial study

Introduction. Secure airway for proper ventilation during anesthesia is one important component of a successful surgery. Endotracheal intubation is one of the most important methods in this context. Intubation method and used medication are considerably important in attenuating complications. This research aimed to investigate the impact of two different doses of dexmedetomidine in mitigating cardiovascular responses to endotracheal intubation in candidate cases supporting voluntary operation. Methods. The current research contained 90 cases in the range of 18 and 50 old, with ASA I,II supporting voluntary operation, who were randomly classified into three teams, each group consisting of 30 cases. The first set (A) got 0.5 μg/ kg dexmedetomidine, the second set (B) got 1 μg/ kg dexmedetomidine and the third set (C) got an equal volume of saline as placebo, 600 seconds earlier the initiation of anesthesia. Hemodynamic parameters were recorded at baseline (T0), then after the injection and the earlier initiation of anesthesia (T1), after the induction of anesthesia and before the endotracheal intubation (T2), promptly after tracheal intubation, 180, and 300 after endotracheal intubation (T4, T5). Data was analyzed and p < 0.05 was supposed notable. Findings. In this research, 3 teams were similar regarding weight, age, height, sex and duration of laryngoscopy. The diastolic mean arterial pressure, heart rate, and systolic arterial pressure were significantly lower in dexmedetomidine teams (A,B) at all times after the endotracheal intubation compared to group C. There were no significant differences in hemodynamic factors among group A, B. Conclusion. Dexmedetomidine effectively and significantly attenuates cardiovascular and hemodynamic responses during endotracheal intubation. In addition, different doses of dexmedetomidine did not cause any significant distinct result in mitigating cardiovascular responses.

Prediction of partition coefficient of some 3-hydroxy pyridine-4-one derivatives using combined partial least square regression and genetic algorithm

A quantiatative structure property relationship (QSPR) treatment was used to a data set consisting of diverse 3-hydroxypyridine-4-one derivatives to relate the logarithmic function of octanol:water partition coefficients (denoted by log po/w) with theoretical molecular descriptors. Evaluation of a test set of 6 compounds with the developed partial least squares (PLS) model revealed that this model is reliable with a good predictability. Since the QSPR study was performed on the basis of theoretical descriptors calculated completely from the molecular structures, the proposed model could potentially provide useful information about the activity of the studied compounds. Various tests and criteria such as leave-one-out cross validation, leave-many-out cross validation, and also criteria suggested by Tropsha were employed to examine the predictability and robustness of the developed model.

Single-nucleotide polymorphisms of TNFA and IL1 in allergic rhinitis

BACKGROUND

Allergic rhinitis is a complex polygenic disorder of the upper respiratory tract. Given that proinflammatory cytokines such as tumor necrosis factor (TNF) and interleukin (IL) 1 seem to play a role in the development of allergic rhinitis, we evaluated the associations between various single-nucleotide polymorphisms (SNPs) of the TNF and IL1 genes in a case-control study.

METHODS

The study population comprised 98 patients with allergic rhinitis. Genotyping was performed using polymerase chain reaction with sequence-specific primers for 2 TNFA promoter variants (rs1800629 and rs361525), 1 variant in the promoter region of IL1A (rs1800587), 2 SNPs in the IL1B gene (rs16944 and rs1 143634), 1 variant in the IL1 receptor (rs2234650), and 1 in IL1RA (rs315952).

RESULTS

Patients who were homozygous for the T allele of rs16944 in IL1B had an 8.1-fold greater risk of allergic rhinitis than those with the C allele. In TNFA, a significant relationship was also detected between rs1800629 and rs361525 and allergic rhinitis. Except for rs1800587 in IL1A and rs315952 in IL1RA, significant differences were found between the patient and control groups for all other SNPs.

CONCLUSIONS

We found that allelic variants in the TNFA and IL1 genes were not only associated with the risk of developing allergic rhinitis, but also affected disease course and severity.

Effect of Ramadan fasting on serum heat shock protein 70 and serum lipid profile

INTRODUCTION

Ramadan, the holy month for the Islamic world, is a period every year when food and fluid intake is restricted to the pre-sunrise and post-sunset hours. The aim of this study was to evaluate the effect of Ramadan fasting on the serum concentration of heat shock protein 70 (HSP70) and serum lipid profile in healthy men.

METHODS

A total of 32 male volunteers with a mean age of 28.5 (range 23-37) years were selected for the study. Blood samples were obtained one day prior to Ramadan and on the 3rd and 25th days of fasting. Serum HSP70, triglyceride (TG), cholesterol (Chol), low-density lipoprotein (LDL) and high-density lipoprotein (HDL), LDL/HDL and Chol/HDL ratios were investigated.

RESULTS

It was observed that the mean concentrations of serum HSP70 and HDL on the 25th day of Ramadan were significantly higher than those recorded one day before Ramadan and on the 3rd day of Ramadan, and the levels on the 3rd day of Ramadan was significantly higher than those recorded one day before Ramadan. Mean concentrations of serum TG, Chol, LDL, and LDL/HDL and Chol/HDL ratios on the 25th day of Ramadan were significantly lower than those recorded one day before Ramadan and on the 3rd day of Ramadan, and the levels found on the 3rd day of Ramadan were also significantly lower than those recorded one day before Ramadan.

CONCLUSION

Ramadan fasting increases serum HSP70 and improves serum lipid profile.

Using a fuzzy controller optimized by a genetic algorithm to regulate blood glucose level in type 1 diabetes

In this paper a closed-loop control algorithm for blood glucose regulation in type 1 diabetic patients is proposed by using the Mamdani-type fuzzy method. Because of the presence of high-pass proportional derivatives in fuzzy designing, optimal values are applied for two inputs and one output membership functions in order to prevent the fluctuations due to derivatives in fuzzy design. Therefore, 19 values which are related to membership functions of the two inputs and one output are obtained by using a genetic algorithm (GA). The new model, termed the Augmented Minimal Model (AMM), is used in simulations. This controller is capable of stabilizing the blood glucose concentration at a normoglycaemic level of 90 mg dl(-1). The operation of the controller under various situations including multiple meal disturbances, and noise due to inaccurate effects of measuring blood glucose level are considered. Uncertainties in the meal disturbance function and variations of model parameters were also taken into consideration in simulations and the controller was found to be robust to such uncertainties.

Strong surface contribution to the nonlinear Meissner effect in d-wave superconductors

We demonstrate that in a d-wave superconductor the bulk nonlinear Meissner effect is dominated by a surface effect due to Andreev bound states at low temperatures. The contribution of this surface effect to the nonlinear response coefficient follows a 1/T3 law with the opposite sign compared to the bulk 1/T behavior. The crossover from bulk dominated behavior to surface dominated behavior occurs at a temperature of T/Tc∼1/square root(κ). We present an approximate analytical calculation, which supports our numerical calculations and provides a qualitative understanding of the effect. The effect can be probed by intermodulation distortion experiments.

Cytokine production by activated T cells in common variable immunodeficiency

BACKGROUND

Common variable immunodeficiency (CVID) is the most common symptomatic antibody deficiency. It is characterized by hypogammaglobulinemia, increased susceptibility to recurrent infections, autoimmunity, and malignancies.

OBJECTIVES

To determine whether patients with CVID have cytokine production defects after T-cell activation and to assess whether or not these are correlated with markers of severe disease.

METHODS

Twenty-seven patients with CVID and 17 healthy volunteers were investigated. Peripheral blood mononuclear cells were cultured under standard conditions in the presence and absence of phytohemagglutinin. Subsequent cell proliferation and cytokine release were measured and compared between stimulated and unstimulated cells.

RESULTS

A general enhancement in cytokine production was observed in both CVID patients and controls after stimulation. However, we detected a lower production of interferon-gamma in CVID patients than in controls (P = .026). A production defect for at least 1 cytokine was observed in 12 patients. Ten of these failed to generate protective titers in response to the polysaccharide vaccine, and the frequency of bronchiectasis in this group of patients was 91.7%. Cytokine release correlated strongly with cell proliferation.

CONCLUSIONS

This study indicates that some CVID patients have T-cell proliferation and secretory defects and that these may be associated with severe manifestations of disease. Screening for such defects could permit more effective monitoring and therapeutic strategies for CVID patients.

Serum concentration of selenium in healthy individuals living in Tehran

Objective

To investigate whether daily diet provides adequate selenium intake in healthy men and women living in Tehran, Iran.

Method

Serum level of selenium was determined in 184 healthy individuals of both genders. The samples were divided into two age groups, adults and children, for analysis. The serum level of selenium was determined using hydride generation and flame atomic absorption spectroscopy.

Results

The mean and standard deviation of serum selenium levels in children (1–16 years) was 84.3 ± 11 μg/l and there was no significant difference between genders in this group. In adults (older than 16 years) the mean serum selenium level was 100.6 ± 13 SD μg/l; among women the mean was 93.9 ± 14 SD μg/l and among men it was 102.2 ± 12 SD μg/l. The mean selenium level in men was higher than in women and data analysis showed a significant difference between them (p < 0.005). There was also a positive correlation between higher selenium serum concentration and age in men (P < 0.001). Daily intake of selenium in men and women was calculated to be 67 μg and 62.1 μg respectively.

Conclusion

Our results show that the serum concentration of selenium in an Iranian population is similar to other nationalities in the Middle East, particularly Saudi Arabia.

Studying nerve conduction velocity and latency of accessory nerve motor potential in normal persons

In order to standardize Nerve Conduction Velocity(NCV), proximal and distal latency and amplitude of motor conduction in intact accessory nerves, a cross-sectional, descriptive-analytic study was done on 60 healthy persons with strict attention to number of cases, distance between stimulation sites, temperature and age. The average results were as follows: Distal latency 2.54 milliseconds (msec.) (2.25-2.83), Proximal latency 3.64 msec. (3.34-3.94), Amplitude 13.76 millivolts (mv.) (8.56-18.96) and NCV 67.98 m/s (56.95-79.01). The average latencies in women were significantly less than men, on both sides which can be due to higher superficial skin temperature in women.