nafiseh nasirzadeh

Due to the recent advances in biomedicine and the increasing understanding of the molecular mechanism of diseases, healthcare approaches have tended towards preventive and personalized medicine. Consequently, in recent decades, the utilization of interdisciplinary technologies such as microfluidic systems had a significant increase to provide more accurate high throughput diagnostic/therapeutic methods.

In this article, we will review a summary of innovations in microfluidic technologies toward improving personalized biomolecular diagnostics, drug screening, and therapeutic strategies.

Microfluidic systems by providing a controllable space for fluid flow, three-dimensional growth of cells, and miniaturization of molecular experiments are useful tools in the field of personalization of health and treatment. These conditions have enabled the potential to carry out studies like; disease modeling, drug screening, and improving the accuracy of diagnostic methods.

Microfluidic devices have become promising point-of-care (POC) and personalized medicine instruments due to their ability to perform diagnostic tests with small sample volumes, cost reduction, high resolution, and automation.

Scientists have focused on the development of new drug delivery systems including pH-sensitive nanomaterials adaptive to tumor microenvironments. We aimed to fabricate a microfluidic system to synthesize and characterize curcumin (Cur)-containing PCL and Chitosan (CSN) polymeric nanoparticles against MCF7 breast cancer cells.

The microfluidic chip was fabricated by photolithography and polydimethylsiloxane (PDMS) molding procedure. The chip was Y-shaped and equipped with two inlets and one outlet. PCL and Chitosan (CSN) were dissolved in acetic acid overnight and mixed with Cur for three hours. The prepared solution was injected from one inlet and a solution of tween 80 in distilled water was injected from the other inlet. The nanoparticles were characterized in size, electrical charge, structure, drug loading, and drug release efficiency. Finally, the cytotoxicity was assessed using the MTT assay at specific concentrations after 24 and 48 hr. 

The mean diameter/zeta potentials of spherical-shaped nanoparticles with and without Cur were 209 ±2 nm / +15 and 219 ± 4 nm /+3 , respectively. FTIR results confirmed the presence of all components in the nanoparticles. The Cur loading rate was 1.5%, and Cur represented a sustained release manner. Also, the release profile showed faster release in a low-pH medium. MTT assay results showed that Cur-containing nanoparticles exerted a significant effect on cell viability. 

It can be concluded that microfluidic systems can pave the way for nanoparticle synthesis easily rapidly and cost-effectively for cancer agent delivery. Based on our observations, PCL-CSN-loaded Cur nanoparticles represent appropriate characteristics and suitable anti-cancer effects.

In recent years, exposure to nanomaterials has been known as a challenge among occupational health experts. In this line, personal protective equipment has been considered as a solution to reduce the worker’s exposure. Since respiratory and skin tracts represent the most common workplace exposure routes, knowledge of the efficiency of respiratory and skin protection equipment is particularly important. So, the aim of this study is the assessment of the efficiency of respiratory and skin protection equipment toward controlling nanoparticles in the workplace with a scoping review approach.

This study was conducted in 2022 with a scoping review approach. Arksey and O’Malley’s five-step framework was chosen as the research method. The search strategy was followed in the databases necessary to access the research data, including PubMed, Google Scholar, Science Direct, Web of Science, and Scopus. Also, EndNote X9® and Microsoft Excel software were used to collect and analyze studies, respectively.

In the first step, 1014 articles were identified. Finally, 38 articles were included in the study to examine quantitative and qualitative information about the efficiency of respiratory and skin protective equipment. Twenty-five articles were related to breathing masks, and six studies were about protective gloves, and seven other articles were devoted to protective clothing. According to the studies of breathing masks, the mean total penetration of nanoparticles was estimated at 2.27%. Also, based on the studies of protective clothing, the maximum penetration of nanoparticles was 30nm for protective clothing made of polypropylene and polyethylene with different layers.

Although the efficiency of existing personal protective equipment showed a good result for controlling nanoparticles, the size of nanoparticles is one of the essential parameters in determining the efficiency of the equipment, which should be considered the workplaces. So, it is recommended that more studies be considered to improve their efficiency, and standard tests should be developed to evaluate them.

Numerous physical and chemical agents can induce destructive effects on the brain tissue. Noise and toluene, which are some of these harmful agents, have significant adverse effects on the brain tissue. This work aimed to investigate the neurotoxic changes induced by co-exposure to toluene and noise. 

A total of 24 male white New Zealand rabbits were randomly segregated into four groups, including toluene exposure, noise exposure, co-exposure to noise and toluene, and control. This in vivo study tested the neurotoxic effects of exposure to 1000 ppm toluene and 100 dB noise during two weeks (8 h/day). The serum levels of brain-derived neurotrophic factor-α (BDNF-α), malondialdehyde (MDA), glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase and total antioxidant capacity (TAC) values in the brain tissue were measured. Moreover, hematoxylin and eosin (H&E) staining was utilized for brain pathological analysis.

Exposure to noise increased TAC values in the cerebral cortex. Co-exposure to toluene and noise increased the serum levels of BDNF-α. Nevertheless, exposure to noise decreased the levels of BDNF-α in serum. On the other hand, histopathological examinations using H&E staining exhibited that different signs of inflammation, such as lymphocyte infiltration, pyknosis, vacuolization, and chromatolysis were induced by exposure to noise and toluene in the cerebellum, hippocampus, and frontal section in the brain tissue. In addition, simultaneous exposure to toluene and noise induced antagonistic and synergistic changes in some neurotoxic parameters.

Exposure to noise and toluene, which caused inflammation in the brain tissue cells, could be a noticeable risk factor for the neurological system.

Carbon-based nanomaterials (CBNs) are the key elements in nanotechnology. The main challenge presented by CBNs is their relationship with the toxicity exposed in the biological systems, because of the incomplete information on their toxicity. This study is aimed to compare the cytotoxicity of graphite nanoparticles (GRNPs), graphene nanoparticles (GNPs), and multi-walled carbon nanotubes (MWCNTs) in A549 cells.
The physicochemical properties of nanomaterials were determined by instrumental techniques. CBNs were dispersed by the nongenotoxic standard procedure. After the cells were cultured, they were exposed to different concentrations of CBNs. Cellular viability was determined by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) method. Moreover, toxicological indicators were obtained using linear probit regression.
The degree of cytotoxicity of CBNs in A549 cells was related to the time and, particularly, dose. At the concentrations of lower than 300 μg/mL, GNPs had stronger toxicity than MWCNTs, but the cytotoxic effects were reversed with the increase of the concentrations. The no-observed-adverse-effect concentration (NOAEC) of GRNPs, GNPs, and MWCNTs was 1.76, 0.06, and 0.65 μg/mL, respectively.
The results indicated that CBNs were toxic and GNPs had stronger toxicity than the others. The experimental results can be useful in increasing the knowledge about the toxicity and health risk management of CBNs.

Asbestos is a natural fiber that induce health risk such as chronic lung diseases. The aim of this study was to estimate pleural mesothelioma and lung cancer risk for a population exposure to asbestos in Tehran, Iran.

According to the annual report of Air Quality Control Company (AQCC), from 2011-2020, carcinogenic risk and mesothelioma was assessed based on environmental protection agency (EPA) method using the Monte Carlo simulation (MCS). Relative risk of morality cancer was calculated based on Camus et al' model. Also, mesothelioma risk was estimated by Bourgault et al' model.

The mean concentration and health risk of asbestos in ambient air has generally reduced from 2011 to 2020. The highest mortality risks for lung cancer, was 8.4 per 100,000 persons in 2011. It had reduced to 1.8, in 2017. For mesothelioma, the corresponding numbers were 8.96 per 100,000 persons in 2011 and it had also reduced to 1.92 in 2017.

Finding of this study could be helpful for health policy makers in management of asbestos risk.

Natural materials are more efficient and attractive than synthetic materials. In this study, the sound absorption behavior by natural kenaf composite and Micro-Perforated Panel (MPP) at low and medium frequency region was investigated.

Initially, the results of kenaf fibers with a thickness of 10 mm were validated by the Finite Element Method (FEM) based on COMSOL Multiphysics 5.3a. The studied combined panel is consisting kenaf fibers with micro-perforated plates and an air layer. This study examined the varying arrangement of the behind layers of the MPP, the different thickness of the layers, and the structural parameters of MPP. The structure with the best absorption coefficient was chosen for the following stage and was considered constant at each stage.

The arrangement of composite layers indicated a strong direct effect on the sound absorption performance; as we discovered that kenaf fibers behind MPP led to better performance in frequencies below 2500 Hz. In addition to the chamber depth behind the MPP, the material and macroscopic properties of the layers, at the same depth, are also important determinants of the exact point of the resonant frequency. Furthermore, configurations in which air layer depth is more than the absorption layer, with the same diameter (hole) and depth (chamber), maximum resonant absorption peak is achieved.

Low-frequency sounds can be successfully dissipated by combining MP plates with kenaf fibers as reinforcing absorber in combined panel. In general, choosing the optimum structural parameters (Composite panel according to structure A with 0.5 mm hole diameter and 2% perforation percentage) allows a significant absorption at a specific frequency range. In this context, the use of numerical estimation to assess the sound absorption behavior can be meticulously substituted the difficult methods and laboratory costs.

Exposure to crystalline silica has long been identified to be associated with lung diseases. Therefore, the present study aimed to assess the risk of silicosis and lung cancer associated with occupational exposure to crystalline silica in Iran. Study Design: It is a systematic review study.

Different databases were searched, and the Cochrane method was used for the systematic review. Thereafter, cumulative exposure to crystalline silica (mg/m3-y) was calculated in every industry. The relative risk of death from silicosis was performed using Mannetje’s method. Based on the geometric mean of exposure, the lung cancer risk of exposure to crystalline silica was also calculated.

As evidenced by the results, worker’s exposure to silica ranged from a geometric mean of 0.0212- 0.2689 mg/m3 (Recommended standard by the American Conference of Governmental Industrial Hygienists (ACGIH) was 0.025 mg/m3), which is generally higher than the occupational exposure limit recommended by National Institute for Occupational Safety and Health (NIOSH), ACGIH, and occupational exposure limits. The relative risk of silicosis was in the range of 1 to 14 per 1000 people, and the risk of lung cancer in workers ranged from 13-137 per 1000 people.

Since workers are at considerable risk of cancer due to exposure to silica in Iran, exposure control programs need to be implemented in workplaces to decrease the concentration of silica.

In recent years, the rapid growth of nanotechnology has posed challenges related to health and safety of nanomaterials. Standardization is one of the first steps in assessing and controlling the risks posed by nanotechnology. Therefore, this study was conducted to review the national standards of Iran regarding the safety, health and environmental aspects of nanotechnology.

This study was conducted in 2021, by searching in the portal of Iranian National Standards Organization (INSO). The search was provided by keywords "nano" and "nanotechnology". The inclusion criteria were the standards related to safety, health and environmental aspects of nanotechnology. A validated checklist was used to evaluate the quality of the standards. Statistical analysis was also performed using SPSS.22 software.

Out of 104 standards, 14 standards were related to safety, health and the environment. Most of the standards were translations of ISO and ASTM standards. Content analysis showed that the standards, in the first years, were about the characteristics of nanomaterials; However, in recent years, they have been developed about preventing exposure to nanomaterials and risk management. Statistical analysis showed that most of the quality evaluation criteria were at the "good" level.

The existence of more than 100 standards, shows the importance of standardization of nanotechnology in the country. Although most of the standards are related to nanotechnology safety in workplaces, we need to increase public and specialized awareness to implement and apply the standards, at the national level.

In international organization, deviant behaviors such as occupational violence is known as a serious crisis. It can lead to mental stress and reduce the job satisfaction, social and family relationships. The aim of this study was to investigate the individual and job factors affecting the incidence of occupational violence among workers in different industries in East Azerbaijan.

Method and material:

 This cross-sectional study was conducted in 2018. Research population consisted of all personnel in five industries, including chocolate factory, food industry, health products, steel and agricultural industry in East Azerbaijan. Data were collected by a researcher made questionnaire, provided based on ILO and WHO standard questionnaires which its validity and reliability were confirmed in previous studies. Data analysis was performed using multiple logistic regression tests by SPSS-V22.

In all the industries, verbal violence, with frequency 46.6%, was the most common type of violence. Internal organizational factors had the important roles in the incidence of occupational violence in these industries. Logistic regression showed statistically significant associations between referring to a psychiatrist (P=0.005), gender (P=0.001), work shift(P=0.001) and occupational violence.

Because verbal violence is prevalence in the industries, it seems that planning and measures should be taken to reduce it. So, deployment of ergonomics and psychology intervention are recommended to reduce the stressful environmental conditions and violence among employees.

Nowadays, multi-walled carbon nanotubes (MWCNTs) are used in various industries. Considering the exposure probability of these nanomaterials to humans, the purpose of the present study is to assess the effect of MWCNTs on cellular toxicity of human alveolar epithelial. The A549 cells were cultured and treated to various doses of MWCNTs at three different times. Finally, the Tetrazolium colorimetric (MTT) assay was implemented for evaluating the cellular viability. The results indicated that the cytotoxicity for MWCNTs on the human alveolar epithelial cells is related to dose and time of exposure. The inhibitory concentration of 50% (IC50) and non-observed adverse effect concentration (NOAEC) are calculated to be 103.6 as well as 0.65μg/mL, respectively. The findings of this present study could contribute to a better understanding of MWCNTs substances and might be useful as a basis for the future risk evaluation studies of exposed population in industries.

Perceived social support in the personnel of any organization is an important psychological factor that affects the efficiency of the workforce and exerts direct and positive effects on the their quality of life. The present study was conducted to investgiate the level of perceived social support in the personnel of a manufacturing industry in Urmia and to determine its relationship with certain demographic variables. The present descriptive study was conducted on 156 personnel of a manufacturing industry in Urmia. Data collection was conducted using the Perceived Social Support Questionnaire. The results obtained were then analyzed using descriptive and analytical statistics, including the chi-squared test and the one-way analysis of variance. The mean value of perceived social support from coworkers (3.36±0.72) was higher than the mean value of perceived social support from managers (2.99±0.65). Perceived social support from coworkers and managers was found to have a statistically significant relashionship with age, work experience and type of employment contract (P-value<0.05). Given that perceived social support from coworkers and managers fell in the medium range in the present study, managers should make efforts to foster a greater social support in the workplace for their personnel and to create better relationships with them in the attempt to improve their performance in different domains. Due to the greater need of the less-experienced personnel for social support, managers are recommended to show their support through devising bonus schemes, providing emotional support and establishing a better relationship with their personnel.