Improvement of the Rheological Behavior of Viscoelastic Surfactant Fracturing Fluids by Metallic-Type Nanoparticles.

The use of nanotechnology in the field of acidizing, particularly in fracturing fluids, has garnered significant attention over the past decade. Viscoelastic surfactants (VESs) are utilized as one of the most effective fracturing fluids, possessing both elasticity and viscosity properties. These fluids are crucial additives in acidizing packages, enhancing their performance. However, various factors, such as salinity, temperature, pressure, and concentration, can sometimes weaken the efficacy of these fluids. To address this, the integration of nanoparticles has been explored to improve fluid retention in reservoirs and enhance the efficiency. This study focuses on investigating the impact of the main metallic-type nanoparticles on the rheological behavior of VES fluids. Iron oxide, magnesium oxide, and zinc oxide nanoparticles were utilized, and the microscopic-scale rheological behavior of the fluids was thoroughly evaluated. The highest performance for enhancing fluid gelation, stability, and rheological characteristics of VES fluids was found for Fe2O3 nanoparticles at an optimum concentration of 500 ppm. At this concentration and shear rate of 100 s-1, the viscosity of the fluid reached 169.61 cP. For iron oxide nanoparticles at a concentration of 500 ppm, by increasing the temperature from 25 to 85 °C, the gelation state of the fluid increased from 7 h and 50 min to 17 h and 45 min. This improvement is attributed to their high surface area and the increased density of entanglement points within the micelles, leading to a more interconnected structure with enhanced viscoelastic properties. Furthermore, iron oxide nanoparticles significantly enhance gelation by physically connecting the micelles, thereby improving stability and structure. The absorption of surfactant molecules by the nanoparticles additionally contributes to micelle reconstruction and shape alteration. The presence of iron oxide nanoparticles helps maintain the gel structure even at elevated temperatures, preventing rapid viscosity decrease. Our findings may provide new insights for development of high-performance, economical, and environment-friendly fracturing fluids used in well stimulation operations.

Mechanistic analysis of matrix-acid treatment of carbonate formations: An experimental core flooding study.

Despite the extensive works carried out on optimal design of the acidizing operations, the detailed mechanisms of the wormholes formation and propagation within the rock structure and their effects on optimum acid injection rate have not been well studied in the available literature. In this work, high pressure-high temperature (HP-HT) acid injection experiments and computed tomography (CT) scan imaging were performed by HCl 15 wt% to discover the mechanisms underlie the creation of wormholes and their extension in the carbonate rocks. The pressure drop profiles and permeability variations before and after acidizing process were employed to identify the optimum acid injection rate. As a final point, core effluent samples were collected and analyzed for justification of the HP-HT experimental results. For performed HP-HT experiments, acid injection rate of 7 cm3/min was obtained as the optimal acid injection rate. The maximum permeability improvement, Kf/Ki = 11.2, was achieved at the optimum acid injection rate corresponded to the minimum acid breakthrough volume, as well as the acid consumption. The results obtained from the CT scan analysis show that the wormhole created in core C.4 is close to the optimal conditions with a single distinctive wormhole to bypass the damage. At acid injection rates lower or higher than the optimum injection rate, the shape of the wormholes changes to conical at very low injection rates and ramified at high injection rates. The highest concentration of calcium at effluent samples was observed for the minimum and maximum injection rates (1 and 15 cm3/min), respectively. The maximum contact time and highest contact area between the acid and rock were attained at minimum and maximum acid injection rates, respectively. As this work was performed at realistic oilfield conditions, it can be used for effective plan, execution and optimization of the acidizing operation in carbonate reservoirs.

AI-Enhanced Detection of Clinically Relevant Structural and Functional Anomalies in MRI: Traversing the Landscape of Conventional to Explainable Approaches.

Anomaly detection in medical imaging, particularly within the realm of magnetic resonance imaging (MRI), stands as a vital area of research with far-reaching implications across various medical fields. This review meticulously examines the integration of artificial intelligence (AI) in anomaly detection for MR images, spotlighting its transformative impact on medical diagnostics. We delve into the forefront of AI applications in MRI, exploring advanced machine learning (ML) and deep learning (DL) methodologies that are pivotal in enhancing the precision of diagnostic processes. The review provides a detailed analysis of preprocessing, feature extraction, classification, and segmentation techniques, alongside a comprehensive evaluation of commonly used metrics. Further, this paper explores the latest developments in ensemble methods and explainable AI, offering insights into future directions and potential breakthroughs. This review synthesizes current insights, offering a valuable guide for researchers, clinicians, and medical imaging experts. It highlights AI's crucial role in improving the precision and speed of detecting key structural and functional irregularities in MRI. Our exploration of innovative techniques and trends furthers MRI technology development, aiming to refine diagnostics, tailor treatments, and elevate patient care outcomes. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 1.

Effect of the bare and functionalized single-wall carbon nanotubes on inhibition of asphaltene molecules aggregation: A molecular dynamic simulation.

A comprehensive study has been carried out by utilizing the molecular dynamics technique in order to investigate the behavior of the N-(1-hexylheptyl)-N'-(2-phenylpropanoicacid)-perylene-3,4,9,10-tetracarboxylicbisimide (PAP) molecules in the n-heptane/toluene solution as well as the role of the bare and functionalized single-wall carbon nanotubes (SWCNTs) with the carboxyl groups (-COOH) on the aggregation of PAP molecules. It was found that the CNTs benefit two mechanism of steric hindrance and adsorbing the PAP molecules to suppress the affinity of PAP molecules to association. The results ascertain that the constant amount of the carboxyl groups acts more efficiently in restricting the growth of aggregate size if they are distributed on the surface of a larger CNT. Both of the increased nonbonding interactions between the functionalized CNTs and the PAP molecules, and the number of formed hydrogen bonds between them clearly proved the efficiency of the -COOH groups in improving the stability of PAP molecules. The strength of the adsorption free energies revealed that the PAP molecule shows more tendency to be adsorbed on the surface of CNT modified with carboxyl groups. Increasing the dosage of the -COOH groups on the surface of the CNTs with constant dimension causes an increment in the PAP molecules' solvent accessible surface area (SASA) value, indicating enhanced stability of the PAP molecules. Finally, the results would facilitate future studies on manipulating the asphaltene precipitation in the oil industry.

The Effect of Active and Passive Smoking on Hearing Loss in Noise-Exposed Metal Workers.

Background: Many people are exposed to cigarette smoke actively or passively. We aimed to determine the effect of active and passive smoking on hearing thresholds and hearing loss noise-exposed workers. Methods: This cross-sectional study was conducted on 929 metal workers. We divided the workers into 3 groups according to smoking status-current smokers, nonsmokers, and passive smokers. Audiometric testing was recorded for both ears. Hearing loss was defined by 3 models. The SPSS software Version 24 was used to analyze the collected data. We used an independent t test, chi-square, Fisher exact, and analysis of variance tests and logistic regression, and the significance level was set at P ˂0.05 to interpret the relationships between variables. Results: The hearing threshold levels at 4000 Hz, high frequencies, and low frequencies were significantly higher in smokers than nonsmokers (P < 0.05). Also, and hearing loss at the 4000 Hz (P = 0.002; odds ratio [OR] = 1.96; 95% CI = 1.27-3.03) and high frequencies (P = 0.001; OR = 2.15; 95% CI = 1.36-3.4) had a significant correlation with smoking. Hearing loss was significantly correlated with passive smoking at 4000 Hz (P < 0.001; OR = 5.87; 95% CI = 3.29-10.47), high frequencies (P < 0.001; OR = 7.16; 95% CI = 3.97-12.89) and low frequencies (P = 0.021; OR = 4.16; 95% CI = 1.12-15.43). Conclusion: The findings show that active and passive smokers who work in noisy environments are at higher risk for noise-induced hearing loss. Therefore, smoking cessation in smoker workers and reduction of environmental exposure to cigarette smoke is necessary to reduce the exacerbation of hearing loss. Moreover, more attention should be paid to passive smokers and they should be given priority in the same programs.

Predictor Factors of Return to Work in Workers with Kidney Transplantation in Iran: A Retrospective Cohort Study.

INTRODUCTION: Return to work after a kidney transplantation in a previously functioning person is determined by a number of medical and non-medical factors. In this regard, this study was to investigate the factors that influence return to work in kidney transplant recipients. METHODS: This retrospective cohort study was conducted in patients with kidney transplant in the main nephrology center in Tehran (December to April 2022). The primary outcome was the cumulative rate of return to work at 3, 6, and 12 months after transplantation. The secondary outcome was to compare the occupational, individual, and disease-related factors between patients who had returned to work and those who had not. RESULTS: Among 214 kidney transplant recipients, the overall cumulative rate of return to work after kidney transplantation at 3, 6 months, and 12 months were 44.4%, 63.1% and 69.6%; respectively. According to the univariate analysis, male sex, age less than 40 years, nonphysical jobs, job satisfaction, employer support, partner support, and absence of diabetes mellitus significantly affected the time of return to work (P < .05). According to the multivariate analysis, absence of diabetes mellitus, nonphysical jobs and job satisfaction had greater impact on the time of return to work (P < .05). CONCLUSION: The results showed that older age, female gender, having a physical job, the presence of diabetes mellitus, lack of job satisfaction, and employer and partner support are associated with not returning to work in these patients and adjusting factors linked to the work environment and support of colleagues and supervisors might play an important role in improving the general condition of these patients.  DOI: 10.52547/ijkd.7210.

Assessment of the relationship between the return to work and the severity of work-related upper limb injuries using the whole person impairment.

PURPOSE: Upper limb disorders are one of the most common and important types of occupational injuries. Besides, identifying the factors influencing return to work following these injuries is essential to reduce the dimensions of the problem. In this study, we investigated the return to work and associated factors following occupational injuries leading to upper limb impairment. METHODS: In this retrospective cohort study, the rate of return to work and associated factors were assessed in 256 workers with work-related upper limb injury referred to a teaching hospital from March 2011 to December 2018. The inclusion criterion was a history of occupational injury resulting in upper limb impairment, and exclusion criteria included the presence of simultaneous impairment in other organs, congenital or non-occupational limb defects as well as patients with incomplete information in their medical records. Individuals' records, including age at the time of injury, gender, date of injury, marital status, education, level of amputation and injury, whole person impairment (WPI) and physiotherapy (prescribed by the physician) were reviewed. The WPI was calculated to assess the extent of the injury. All analyzes were performed by SPSS version 25.0. RESULT: The rate of return to work was 54.3%, in which 51.8% for the same job and 48.2% for a new job. The main factors associated with non-return to work were more days off work (p = 0.001), higher injury severity (p = 0.001), and dominant hand injury (p = 0.034). CONCLUSION: The number of days off work, the WPI, and dominant hand injury are the most important determinant in returning to work. In addition, increased job satisfaction and support from co-workers and employers are work-related factors that can lead to an increased return to work.

Prevalence of Parkinsonism Among Foundry Workers in an Automobile Manufacturing Factory in Tehran.

Background Manganese, as an essential element, has neurotoxic effects on basal ganglia and causes parkinsonism, dystonia, and cognitive symptoms in exposed individuals. Transcranial sonography (TCS) is a noninvasive and easily accessible imaging modality for detecting the accumulation of trace elements in the basal ganglia. Methodology In a cross-sectional study of foundry workers of one of the automobile manufacturing companies in 2019, the prevalence of parkinsonism was assessed through neurological examination and brain parenchymal sonography or TCS. The prevalence of parkinsonism according to age, smoking, work experience, marital status, and exposure to manganese was determined. Results Among 83 male workers, the prevalence of parkinsonism according to neurological examination, substantia nigra hyperechogenicity on TCS, lentiform nucleus hyperechogenicity, and totally was 33.7%, 9.6%, 10.8%, and 42.2%, respectively. The association between the prevalence of parkinsonism and age, smoking, work experience, marital status, and manganese exposure was evaluated. Parkinsonism according to lentiform nucleus hyperechogenicity was associated with smoking (odds ratio [OR] (95% confidence interval [CI]) = 26.63 (2.38-178.71)) and work experience (OR (95% CI) = 7.18 (0.84-61.32)). Conclusions According to this study, the prevalence of parkinsonism based on neurological examination or brain sonography findings was 42.2%. The implementation of this combined screening method might facilitate earlier detection of affected individuals among manganese-exposed workers.

Return-to-Work Status Following One- and Two-Level Anterior Cervical Discectomy and Fusions: A Prospective Cohort Study.

BACKGROUND:  The purpose of this article was to determine the rate of return to work (RTW) and contributing factors after a one- and two-level anterior cervical discectomy and fusion (ACDF), a common spine surgery. Recognizing the contributing factors to RTW of occupationally active patients is important. METHODOLOGY: In this study, 68 patients were examined at three, six, and nine months after ACDF by the same team and same spinal surgeon at a single medical center, and the rate of RTW and contributing factors were determined. In this study, relationships were analyzed by the logistic regression method. RESULTS: The results of this study demonstrated that 77.9%, 82.4%, and 82.4% of workers had returned to work after three, six, and nine months, respectively. At nine months, 82.4% of the patients had returned to work, 19.6% returned to part-time work, and 80.4% had returned to their previous work. Conversely, 17.6% of the patients had not returned to work after nine months. In the logistic regression analysis, older age, longer absence from work before surgery, and less employer support were the related factors for no RTW. CONCLUSIONS:  Per the results, it may be concluded that nearly 82% of patients with ACDF had returned to work after nine months of follow-up. Lack of RTW is affected by older age, longer absence from work before surgery, and employer support. Planning according to these variables can reduce the burden of the problem.

Return to Work and Associated Factors After the First Hospitalization for Heart Failure.

OBJECTIVE: Heart failure (HF) is a public health problem worldwide. Employment is vital in terms of personal, social, and economic aspects for patients with chronic diseases. The aim of this study is to investigate returning to work and the associated factors after first hospitalization for HF in working- age patients. METHODS: In this retrospective cohort study, patients with the first hospitalization for HF in 2017-2020 who were employed before hospitalization were included. The demographic, occupational, and disease-related variables were compared in subjects with and without returning to work. Next, the relationship between the variables and the number of days off work was examined in participants who had returned to work. RESULTS: The data of 204 participants were analyzed. About 90% of the participants returned to work after one year. There was a significant relationship between not returning to work and higher age, female sex, higher New York Heart Association (NYHA) class, Ejection fraction (EF) ≤ 40%, and history of chronic kidney disease (CKD). Among the participants who had returned to work, income level, cause of work exit, employer support, and the number of rehabilitation sessions had a significant relationship with the number of days off work. CONCLUSION: The results of this study showed that gender, age, EF level, history of CKD, and NHYA class were the most influential factors in returning to work after first HF hospitalization. Furthermore, income, cause of work exit, employer support, and the number of rehabilitation sessions were the most important factors contributing to the number of days off work.

The Effect of Physical Exposures and Job Stress on Sleep Quality and Mental Health in a Group of Pink-Collar Workers in Iran.

Background: Pink-collar workers are a group of workers in the service industries. Teachers are classified as a group of pink-collar workers, who are under a high level of stress. This study aimed to investigate the effect of physical exposures and job stress on mental health and sleep quality of technical and vocational teachers. Materials and Methods: This cross-sectional study was conducted on 622 teachers. The Pittsburgh Sleep Quality Index (PSQI) and the Epworth Sleepiness Scale (ESS) were employed to evaluate sleep status; the Osipow Questionnaire was used to assess job stress; the musculoskeletal intervention center - Norrtalje questionnaire (MUSIC) was used to measure physical exposures; and the 12-Item General Health Questionnaire was used to assess mental health. Results: The mean scores of general health, job stress, and work hardness were 10.97 ± 6.29, 153.40 ± 22.63, and 15.61 ± 2.77, respectively; the mean score of ESS and PSQI were 6.22 ± 3.61 and 5.44 ± 2.97, respectively. The mental health status of the participants was significantly worse with more exposure to various types of job stressors and physical exposures. There was a significant relationship between sleep quality and general health score. Conclusion: The mental health status was considerably better in women, smokers, and people who exercised, have less work experience, do not do shift work, work fewer hours per week, and have good sleep quality. Physical exposures and various occupational stressors can reduce mental health. There was a significant relationship between job stress and decreased sleep quality but sleep quality was not significantly associated with age, BMI, work experience, and working hours per week.

PSSMCOOL: a comprehensive R package for generating evolutionary-based descriptors of protein sequences from PSSM profiles.

Position-specific scoring matrix (PSSM), also called profile, is broadly used for representing the evolutionary history of a given protein sequence. Several investigations reported that the PSSM-based feature descriptors can improve the prediction of various protein attributes such as interaction, function, subcellular localization, secondary structure, disorder regions, and accessible surface area. While plenty of algorithms have been suggested for extracting evolutionary features from PSSM in recent years, there is not any integrated standalone tool for providing these descriptors. Here, we introduce PSSMCOOL, a flexible comprehensive R package that generates 38 PSSM-based feature vectors. To our best knowledge, PSSMCOOL is the first PSSM-based feature extraction tool implemented in R. With the growing demand for exploiting machine-learning algorithms in computational biology, this package would be a practical tool for machine-learning predictions.

The relationship between occupational exposure to organic solvents and metabolic syndrome in petroleum refinery workers in Tehran, Iran.

AIMS: The rising prevalence of metabolic syndrome has made it a major health concern. Chronic occupational exposure to organic solvents affects different systems of the body. This study aimed to investigate the association between exposure to organic solvents and the prevalence of metabolic syndrome in petroleum refinery workers. METHOD: This study was conducted in 2019-2020 on workers employed in an Iranian petroleum refinery. The demographic and occupational information on the participants was obtained using the interview method. Their height, weight, and blood pressure were measured by the occupational health team, and fasting blood samples were taken from them to measure the paraclinical parameters. RESULTS: In this study, 1009 petroleum refinery workers were analyzed. The prevalence of metabolic syndrome in workers was 20.1% and it was about two times higher in exposed workers (CI 95%: 1.61-3.35) compared to non-exposed ones. Factors associated with the prevalence of metabolic syndrome include age, higher BMI, exercise, and longer exposure to organic solvents. CONCLUSION: Findings of this study suggested that exposure to organic solvents is associated with increased prevalence of metabolic syndrome (the highest association was observed with elevated serum triglycerides). Besides, longer exposure to organic solvents increased the risk of developing metabolic syndrome.

Conjugation of imipenem to silver nanoparticles for enhancement of its antibacterial activity against multi-drugresistant isolates of Pseudomonas aeruginosa.

Due to the broad-spectrum of antibiotic resistance, herein we investigated the possibility of using imipenemconjugated silver nanoparticles (IMP-AgNPs) against multidrug-resistant isolates of Pseudomonas aeruginosa. For this purpose, 200 clinical isolates were tested against different antibiotics to determine the antimicrobial susceptibility. To identify blaVIM and blaIMP resistance genes, PCR was used. The synthesized AgNPs and conjugants were characterized using UV-vis spectroscopy, XRD, SEM, TEM, DLS, and FTIR. The stability, drug release kinetics, cytotoxicity, hemolytic and apoptotic effects of NPs were also investigated. MIC of the imipenem, AgNPs, and conjugants were evaluated versus P. aeruginosa isolates. Finally, the effects of the IMP-AgNPs to heal burn wounds in rats was evaluated. According to the results, about 68% of isolates showed resistance to imipenem (MIC ≥ 64 µg/ml to ≥ 512 µg/ml). Analytical results verified the synthesis of AgNPs and IMP-AgNPs. A Dose-dependent decrease happened in terms of the MIC values of IMP-AgNPs were also affected by the existence of resistant genes. Low cytotoxic was observed regarding AgNPs which lead to apoptosis. The histopathological results showed a considerable epithelization in treated groups with IMPAgNPs. Accordingly, IMP-AgNPs can be considered as a powerful antibacterial agent to treat the infections caused by multidrug-resistant P. aeruginosa.

Assessment of disability levels in patients with low back pain based on the type of lumbar spinal disorder.

BACKGROUND: Low back pain (LBP) is a common health condition and the leading cause of activity limitation and absenteeism in most parts of the world. One-fifth of patients with LBP develop chronic pain disability. OBJECTIVE: This study investigated the disability levels in patients with different types of lumbar spinal disorders. METHODS: A total of 528 patients visiting spine clinics between June 2017 and February 2018 were enrolled in this study. A demographic checklist, the patients' medical records, the Oswestry Disability Questionnaire, and the Visual Analog Scale (VAS) were used to collect the data. RESULTS: Non-specific LBP (29.5%) and discopathy (27%) were the most common final diagnoses. The obtained Oswestry Disability Index (ODI) was significantly higher in older patients, those with higher body mass index, more work experience, and smokers. Lower ODI was found in individuals with a history of regular exercise. Most individuals in all diagnostic groups were categorized into the high ODI group (p⩽ 0.001). CONCLUSION: In patients with lumbar spine lesions, ODI is significantly correlated with age, BMI, work experience, smoking, and the type of disorder (discopathy, spondylolysis, and spondylolisthesis). Regular exercise is associated with lower levels of disability.

The Relationship between Occupational Exposure to Lead and Hearing Loss in a Cross-Sectional Survey of Iranian Workers.

OBJECTIVES: Ototoxic effect of exposure to lead has been reported by many researchers. This study was undertaken with a view to investigate the relationship between blood lead level (BLL) and hearing loss in workers in a lead-acid battery manufacturing plant in Tehran, Iran. METHODS: In a cross-sectional study, 609 male workers were recruited from different locations in the factory. Association between BLL and hearing loss in different frequencies were measured. Relationships were analyzed by logistic regressions. Statistical significance was defined as p-value <0.05. RESULTS: Six hundred nine male workers with mean age 40 ± 7 years and mean noise exposure level of 80 (75-85) dB were evaluated. BLLs were categorized into four quartiles, and hearing loss in each quartile was compared to the first one. In our regression models, BLL was associated significantly with high frequency hearing loss, adjusted odds ratios for the comparison of the fourth, third, and second quartiles to the first one are respectively: 3.98 (95% CI: 1.63-9.71, p < 0.00), 3.05 (95% CI: 1.28-7.26, p < 0.01), and 2.89 (95% CI: 1.11-7.51, p < 0.03). CONCLUSION: This study showed a dose-response relationship between BLL and hearing loss, after adjusting for potential confounders (age, body mass index, work duration, smoking, and occupational noise exposure) in logistic regressions. It is concluded that periodic hearing assessment by pure tone audiometry in workers exposed to lead should be recommended. However, additional studies are required to clarify the mechanisms of lead ototoxicity.

Interaction of Physical Exposures and Occupational Factors on Sickness Absence in Automotive Industry Workers.

INTRODUCTION: Increased sickness absence in recent years has been a trouble making issue in industrial society. Identify the causes of sickness absence and its influencing factors, is an important step to control and reduce its associated complications and costs. The aim of this study was to evaluate main factors associated with the incidence of sickness absence. PROCEDURE: In 2012, a cross-sectional study on 758 employees of a car accessories producing company was applied and relevant information about the number of days and episodes of sickness absence, Disease resulting in absence from work, personal features, occupational factors and physical exposures were collected. To determine risk factors associated with sickness absence, Logistic regression analysis was used. RESULTS: The most common diseases leading to sickness absence in order of frequency were Respiratory diseases, musculoskeletal disorders, gastrointestinal diseases and injuries at work. Musculoskeletal disorders increased the danger of long term absence by 4/33 times. Blue collar and shift works were the most important occupational factors associated with the incidence of sickness absence. The main physical factors that affect incidence of sickness absence were frequent bending-twisting and heavy lifting. CONCLUSION: Identifying controllable factors of sickness absence and trying to prevent and modify them such as compliance of ergonomic principals to decrease physical can be effective in reducing sickness absence.

The Relationship between Disease, Work and Sickness Absence among Psoriasis Patients.

BACKGROUND: The aim of this study was to assess the prevalence of absenteeism in patients with psoriasis and determine the factors influencing the incidence of absenteeism in these patients. METHODS: A cross-sectional study from December 2012 to November of 2013 was conducted on 192 psoriasis patients referred to the Dermatology Clinic of Imam Khomeini Hospital, Tehran, Iran. The number day of absence from work due to psoriasis in the last year was asked from the patients; the absence of 7 days has been considered as short-term and more than 7 days as long-term. Logistic regression was used to data analysis. RESULTS: Sickness absence in 21.4% of patients was positive. The average numbers of days of absence were 10.25 and the duration of absence from work in 48.7% were long-term ≥7 days. 51.3% had short-term absence (<7 days). Among disease factors: moderate to severe disease (SAPASI score >10), palms and soles involvement, joint problems and radiation therapy and among job factors: hazardous physical and chemical exposures in the workplace, non-office work, disability, exacerbations of disease on work days and problem on employment were associated with high incidence of sickness absence. CONCLUSION: Psoriasis with its chronic and recurrent nature especially in higher severities causes disabilities that deeply affect Work performance and can decrease the efficiency. In better management of psoriasis patients, physicians should pay special attention to occupational factors.

Prognostic factors for return to work after low-back disc herniation surgery.

Return to work (RTW) is an important outcome following disc herniation surgery. The present study aimed at determining factors that may affect early RTW after disc herniation surgery. Data were collected from 603 patients who underwent disc herniation surgery in an educational hospital via phone interviews during a 4-year period (2005-2009). Delayed RTW and failed RTW were associated with female gender, lower educational levels, longer hospitalization periods, greater BMI, biological age exceeding 40 years, employment in manual labor, lack of encouragement by the physician to RTW, being in pain at the time of the phone interview, having negative expectations about the outcome of surgery preoperatively, and low job satisfaction (P < .05). Psychological and occupational factors have direct effects on RTW. Important factors include positive expectations about the outcome of surgery, encouragement by the physician to RTW, job characteristics, and job satisfaction. RTW can be accelerated by appropriate strategies and team work.

Assessment of neuro behavioral disorders in workers exposed to organic solvents in a publication house.

BACKGROUND: Organic solvents are known as a group of organic compounds, widely used in industry and to which many workers are exposed. Neurotoxicity is one of the most important complications of the chronic exposure to the solvents and may causes neurobehavioral disorders in workers. We have studied the frequency of neurobehavioral disorders in workers exposed to organic solvents in one of the publishing houses in Tehran. METHODS: In this cross-sectional study, 510 workers of a publishing house, having been employed at least a year before the research, were selected to be studied. Among them, 345 workers had been exposed to organic solvents and the other (165 workers) had not. Data were collected using a questionnaire. This questionnaire included demographic and occupational information, and the Swedish Q16 questionnaire. Variables included age, duration of employment, working shift, and smoking. Then we compared both groups in terms of neurobehavioral disorders, using statistical methods. RESULTS: The mean score of the Swedish Q16 questionnaire in the exposed group (4.8±4.4) was significantly higher than the non-exposed group (3.2±3.1) (p=0.001). According to the questionnaire score, the frequency of neurobehavioral disorders in the exposed group was 38% and in the non-exposed group was 22% (p=0.001). We estimated that the frequency of neurobehavioral disorders in the exposed group was significantly higher than the non-exposed group (p<0.05) using regression analysis and removal of the confounding factors. CONCLUSION: This study shows that the frequency of the neurobehavioral disorders in the exposed group is significantly higher than the non-exposed group.