Association metrological factors with Covid-19 mortality in Tehran, Iran (2020-2021).

The outbreak of the Coronavirus disease (COVID-19) has raised questions about the potential role of climate and environmental factors in disease transmission. This study examined meteorological and demographic factors to determine their impact on mortality and hospitalization rates in Tehran, Iran from January 1, 2021, to December 31, 2022. Notably, hospitalization cases were positively associated with temperature (P-value: 0.001 in spring, P-value: 0.045 in winter) and pressure (P-value: 0.004 in spring), while being negatively associated with wind speed (P-value: 0.03 in spring, P-value: 0.01 in autumn) and humidity (P-value: 0.001 in autumn) during the spring and autumn seasons. Conversely, mortality was associated with wind speed (P-value: 0.01) and pressure (P-value: 0.02) during winter and spring, respectively. Moreover, temperature was associated with mortality in both spring (P-value: 0.00) and winter (P-value: 0.04). The findings suggest that identifying the environmental factors that contribute to the spread of COVID-19 can help prevent future waves of the pandemic in Tehran.

Design and psychometric evaluation of health system intervention assessment tools for children in floods.

BACKGROUND: Flood is one of the most frequent disasters in Iran, which has highly affected the population and consequences on the health system. Children as the most vulnerable group too need to receive health services during floods. The aim of the present study was to develop a national tool for evaluating the provision of health services to children in floods. MATERIAL AND METHODS: This study is a sequential-exploratory mixed method study that consists of two qualitative and quantitative stages. The qualitative part includes the analysis of documents and panel of experts while the quantitative part includes the design and validation of the tools. RESULTS: In this study, organizations providing health services to children were first identified, and according to their mission the relevant items were extracted and the initial checklist was designed. Then validity and reliability of the tools were done. The content validity ratio and content validity index for the tool were 59 and 98%, respectively. Cronbach's alpha and intraclass correlation coefficient were determined as 0.7 and 0.964, respectively. The final tool was presented with 64 items. CONCLUSIONS: The response program, the scope of interventions, service coverage, and the effectiveness of the response after the flood can help reduce the risk of disasters in children. Using the assessment tool of evaluating the health services to children can assist the stakeholder organizations to meet the standards and best quality of services. Assessing the needs of the children affected by floods, identifying the strengths and weaknesses of health services, and proposing corrective strategies according to the information extracted from this tool are other achievements of this study.

The effect of magnesium sulfate on gene expression and serum level of inflammatory cytokines in coronary artery disease patients.

PURPOSE: To evaluate the effect of oral magnesium sulfate (MgSO4) on the gene expression and serum levels of inflammatory cytokines including TNF-α, IL-18, IL-1ß, IL-6, and IFN-γ in patients with moderate coronary artery disease (CAD). METHODS: 60 CAD patients were selected based on angiography findings and were randomly divided into two groups that received 300 mg/day MgSO4 (n = 30) or placebo (n = 30) for 3 months. Gene expression and serum levels of inflammatory cytokines were assessed. RESULTS: After 3 months of intervention, gene expression and serum levels of IL-18 and TNF-α in the MgSO4 group were significantly less than the placebo group (P < 0.05). However, no significant difference in gene expression and serum levels of IL-1ß, IL-6, and IFN-γ was observed between the two groups (P > 0.05). In addition, within group analysis demonstrate that Mg-treatment significantly decrease serum level of TNF-α and IL-18 as compared to pretreatment. CONCLUSION: The results of our study demonstrate that 3-month magnesium sulfate administration (300 mg/day) to CAD patients could significantly decrease serum concentration and gene expression levels of IL-18 and TNF-α. Our findings support the potential beneficial effect of magnesium supplementation on alleviating CAD complications through modulating inflammatory cytokines.

Experimental investigation and simultaneous modeling of the effect of methylene blue addition to cancer tumors in photodynamic therapy by digital holography.

BACKGROUND: Although many types of cancers can be treated with surgery, alternatives such as photodynamic therapy with simultaneous use of photosensitive materials and illumination can also be used. Knowing the dose of absorbed energy from the light beam in the photo-sensitized tumors and tissues has an important role in designing the optimal irradiation method with the aim of investigating the amount of received damage to the healthy and tumor tissues. METHODS: In this study, the effect of the presence of methylene blue sensitizer on the amount of dose received in tissue-equivalent material has been investigated experimentally by Mach-Zehnder interferometry and digital holography. The Monte Carlo method and the ValoMC code have been used to confirm the results obtained in the experimental phase. RESULTS: The results indicate the positive role of methylene blue in increasing the absorbed dose of tumor-equivalent material. The amount of light dose increase and the two-dimensional profile of the dose absorbed in tissue and tumor equivalent materials have been measured by digital holography. CONCLUSIONS: The method presented in this work can be used in treatment design and real time measuring of the spatially resolved distribution of the absorbed dose in the tissues containing tumors.

Assessment of semen quality of taxi drivers exposed to whole body vibration.

Whole body vibration (WBV) is a recognized occupational hazard for many workers such as drivers and operators of heavy and light machinery and exposure to it is accompanied by physical and mental repercussions. Only the limited studies have been done on the effects of vibration exposure on reproductive indices, however vibration exposure has been indicated as being a hazardous agents with the potential of being able to directly affect the reproductive system. Considering the importance of infertility, the present study was conducted with the aim of investigating semen quality among taxi drivers in Tehran and determine the effect of exposure to WBV on sperm parameters. The study population consisted of 70 taxi drivers and 70 office employee who attended infertility clinics for diagnostic purposes in the past year. The participants had to meet the entry criteria of the study while also being willing to recruit. Data was collected in the form of demographic questionnaires and general health questionnaires as well as sperm analysis conducted in an infertility clinic according to standard laboratory guidelines. The 8-hour time-weighted average (TWA) exposure to of WBV in automobile was measured as per ISO 2631-1. The TWA exposure to WBV among the taxi drivers and office employees were 0.697 ± 0.13 m/s2 and 0.068 ± 0.09 m/s2 respectively (P < 0.05). A statistically significant difference in total sperm count, progressive motility, non-progressive motility and total motility was observed between the taxi drivers and the office employees (P < 0.05). According to the univariate analysis of variance, exposure to WBV had negative effect on sperm concentration, progressive motility and normal morphology (P > 0.05); moreover exposure to WBV resulted in the larger effect size (B) on sperm parameters than the demographic variables (P > 0.05). Being taxi drivers increase the chance of the decreased semen quality (P > 0.05). It is difficult to draw definitive conclusions regarding the effects of WBV while intervening factors exist, such as psychological stressors, quality of sleep, background issues as well as environmental factors such as chemical pollutants (heavy metals) or ergonomic factors (body posture and working while sitting down).

Integrated ultrasound-assisted magnetic solid-phase extraction for efficient determination and pre-concentration of polycyclic aromatic hydrocarbons from high-consumption soft drinks and non-alcoholic beers in Iran.

In the present research, an ultrasound-assisted magnetic solid-phase extraction coupled with a gas chromatography-mass spectrometry hybrid system was developed for the extraction/determination of trace amounts of polycyclic aromatic hydrocarbons in high-consumption soft drinks and non-alcoholic beers in Iran using magnetite graphene oxide adsorbent. The magnetite graphene oxide was characterized by scanning electron microscope, transmission electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and vibrating-sample magnetometer techniques. The highest extraction recovery (73.05%-95.56%) and enrichment factor (90.65-106.38) were obtained at adsorbent mass: 10 mg, adsorption time: 30 min, salt addition: sodium chloride 10% w/v, desorption time: 20 min, eluent type: hexane: acetone (1:1, v/v), and desorption solvent volumes: 200 µl. Under optimum conditions, the linearity range for polycyclic aromatic hydrocarbons determination was 0.2-200 ng/ml with a coefficient of determination > 0.993, the limit of detection = 0.09-0.21 ng/ml, the limit of quantitation = 0.3-0.7 ng/ml, and relative standard deviation < 8.1%, respectively. Relative recoveries in spiked real samples ranged from 94.67 to 109.45% with a standard deviation < 6.05%. The proposed method is effective, sensitive, and reusable and it is promising for the analysis of polycyclic aromatic hydrocarbons residues in environmental samples.

Architecting of an aptasensor for the staphylococcus aureus analysis by modification of the screen-printed carbon electrode with aptamer/Ag-Cs-Gr QDs/NTiO2.

Given the many issues bacterial infections cause to humans and the necessity for their detection, in this work we developed a robust aptasensor for prompt, ultrasensitive, and selective analysis of staphylococcus aureus bacterium (S. aureus). A nanocomposite of Ag nanoparticles, chitosan, graphene quantum dots, and nitrogen-doped TiO2 nanoparticles (Ag-Cs-Gr QDs/NTiO2) was synthesized, and thoroughly characterized by XRD, FT-IR, and FE-SEM spectroscopic methods. The surface of screen-printed carbon electrodes modified with Ag-Cs-Gr QDs/NTiO2 nanocomposite was utilized as a compatible platform for aptamer attachment. The aptasensor accurately determined S. aureus in the dynamic range of 10-5 × 108 CFU/mL with detection limit of 3.3 CFU/mL. The monitoring of the practical performance of aptasensor in human serum samples revealed its superiority over the conventional methods (relative recovery of 96.25-103.33%). The Ag-Cs-Gr QDs/NTiO2-based aptasensor offers facile, biocompatibility, good repeatability, reproducibility (RSD = 3.66%), label free and stabile strategy for sensitive S. aureus analysis free from biomolecules interferences in actual specimens.

Comprehensive analysis and investigation of accident/occupational disease responsibility rates: A case study for accidental CO poisoning.

One of the major problems of courts and insurance companies is the lack of a proper technique to determine the rate of responsibility of the parties involved in the accident. The aim of this study was to determine the Accident/Occupational Diseases Responsibility Rates (AOD RR) for complex events. Accordingly, a case study of a complex accident of carbon monoxide (CO) poisoning was selected and Occupational Accident Tree Analysis (OATA) and Occupational Accident Component Analysis (OACA) techniques, which were solely used to investigate occupational accidents, were used with the new names Accident/Occupational Disease Tree Analysis (AOD TA) and Accident/Occupational Disease Component Analysis (AOD CA) to evaluate their applicability to investigate non-occupational accidents and occupational diseases. For this purpose, causes of CO penetration to victims' room was assessed using gas tracking methods. Finally, Fuzzy Accident/Occupational Disease Tree/Component Analysis (FAOD TA and FAOD CA) techniques were developed and used for determining AOD RR in fuzzy environment. The results showed that the AOD RR obtained by AOD TA and AOD CA based on the average of experts' personal opinions and consensus between experts, and AOD TA and AOD CA in a fuzzy environment were close to each other, with the power terminal and the power cable crossing route being the main routes of transmission and penetration of CO to the victims' room. Also, the owner, contractor, tenant, and serviceman were responsible for the CO poisoning of victims. It can be concluded that any hole, crack, or fission in the building can result in CO penetration to the individuals' living rooms, and gas tracking in early winter, especially in older buildings, plays a very significant role in preventing residents' poisoning. Further, due to the uncertainty of AOD TA and AOD CA techniques, it is recommended to use FAOD TA and FAOD CA techniques for increasing the accuracy of the results. This will enhance the court and insurance companies' trust in the opinions of accident investigation experts, decrease delays in the proceedings, and prevent any violation of the individual rights.

Aspects of Epidemiology, Pathology, Virology, Immunology, Transmission, Prevention, Prognosis, Diagnosis, and Treatment of COVID-19 Pandemic: A Narrative Review.

Undoubtedly, COVID-19 pandemic is one of the largest pandemics and one of the biggest international challenges for health-care system of various countries in the world. This is a narrative review study based on the studies published related with different aspects of COVID-19. The highest numbers of active cases are in the USA, Brazil, India, Russia, South Africa, as well as Colombia and the disease surveillance system must operate more quickly, timely, effectively, and sensitively in these countries. What is clear is that the SARS-CoV-2 basic reproduction number is significantly higher than one and its transmission power is extremely high. In general, it can be stated that mortality and fatality risk due to COVID-19 in men, age increase, severity of disease, systemic disease, as well as inadequate access to the sufficient health-care services will increase. There is currently no specific treatment and effective vaccine for COVID-19. The novel coronavirus pandemic is more consistent with the epidemiological triangle model, which emphasizes that the disease is the result of the interaction of three factors of host, agent, and environment. Therefore, prevention and treatment activities should focus on cutting the virus transmission chain. The main way to deal with viral epidemics is prevention. The emerging of this ruthless virus has once again reminded us that communicable diseases should never be underestimated and forgotten. Considering the rapid transmission of COVID-19, the health-care authorities and workers should consider timely detection and safeguards to prevent the transmission to healthy individuals.

Spatiotemporal analysis of solar ultraviolet radiation based on Ozone Monitoring Instrument dataset in Iran, 2005-2019.

The solar ultraviolet radiation (UVR) at national, provincial and county levels in Iran during 2005-2019 were determined based on Ozone Monitoring Instrument (OMI) dataset. The temporal (annual and monthly) trends and spatial distributions of the UVR in terms of erythemally weighted daily dose (EDD), erythemally weighted irradiance at local solar noon time (EDR), and UV index and the major factors influencing the spatiotemporal trends were analyzed. The population-weighted average values of EDD, EDR, and UV index in Iran were respectively 3631 J/m2, 176.3 mW/m2, 7.1 in 2005 and rose by 0.22% per year to 3744 J/m2, 181.7 mW/m2, and 7.3, respectively in 2019, but the annual trend was not statistically significant. The EDD in Iran during the study period exhibited the highest monthly average value in June (6339 J/m2) and the lowest one in December (1263 J/m2). The solar UVA/UVB ratios at the national level during 2005-2019 were considerably lower in summer. The EDD provincial average values in the study period were in the range of 2717 (Gilan) to 4424 J/m2 (Fars). The spatiotemporal variations of the solar UVR parameters were well described by the linear models as a function of cloud optical thickness (COT), ozone column amount, surface albedo, latitude, and altitude (R2 > 0.961, p value < 0.001) and the temporal changes of the solar UVR parameters were mainly caused by the COT. The results indicated that non-burning exposure to solar UVR in summer can be more efficient for vitamin D synthesis due to higher contribution of UVB in the solar UVR. The spatial distributions and temporal trends should be considered to determine the optimal duration, time and condition of exposure to the solar UVR for the public and occupational training and public health measures.

The Prevalence of Musculoskeletal Disorders among Miners around the World: A Systematic Review and Meta-Analysis.

BACKGROUND: Musculoskeletal disorders are responsible for significant problem for workers' health. The present study aimed to investigate the prevalence of musculoskeletal disorders among mining workers. METHODS: This systematic review and meta-analysis study were designed in 2020 (from Jan to Mar). The researchers searched five international databases Medline/PubMed, ProQuest, Scopus, Embase and Web of Science. All analyzes were performed using STATA statistical software. RESULTS: The search results were 447 articles and after screening stage finally 50 studies were included in review. The highest number of studies (26 studies) reported the prevalence of musculoskeletal disorders of upper back and 4 studies reported the prevalence of musculoskeletal disorders of the arms and ankles & feet. The results of meta-analysis based on prevalence in different organs showed that the highest prevalence of musculoskeletal disorders was in the upper back and the lowest in the knees with a prevalence of 50.39% (CI 95%: 31.23-54.73%) and 16.03% (CI 95%: 11.78-20.28%), respectively. CONCLUSION: The prevalence of musculoskeletal disorders among miners is relatively high. Therefore, supervisors and mine managers should pay more attention to reducing musculoskeletal disorders and increasing the ergonomic level of mines in order to increase workers' health.

Large Optical Nonlinearity of the Activated Carbon Nanoparticles Prepared by Laser Ablation.

Carbon nanoparticles (CNPs) with high porosity and great optical features can be used as a luminescent material. One year later, the same group investigated the NLO properties CNPs and boron-doped CNPs by 532 nm and 1064 nm laser excitations to uncover the underlying physical mechanisms in their NLO response. Hence, a facile approach, laser ablation technique, was employed for carbon nanoparticles (CNPs) synthesis from suspended activated carbon (AC). Morphological properties of the prepared CNPs were studied by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). UV-Vis and fluorescence (FL) spectra were used to optical properties investigation of CNPs. The size distribution of nanoparticles was evaluated using dynamic light scattering (DLS). The nonlinear optical (NLO) coefficients of the synthesized CNPs were determined by the Z-scan method. As a result, strong reverse saturable absorption and self-defocusing effects were observed at the excitation wavelength of 442 nm laser irradiation. These effects were ascribed to the presence of delocalized π-electrons in AC CNPs. To the best of our knowledge, this is the first study investigating the NLO properties of the AC CNPs.

A systematic review of health sector responses to the coincidence of disasters and COVID-19.

BACKGROUND: In December 2019, the Chinese city of Wuhan reported a novel pneumonia caused by COVID-19. While the COVID-19 pandemic has been increasingly affecting the world, the occurrence of disasters resulted in complex emergencies. The present review is aimed to identify the literature focused on health system response to coincidence of COVID-19 and disasters as well as describing their finding, implications and lessons-learned. METHODS: This study was conducted and reported based on PRISMA guideline. The databases of Web of Sciences, PubMed, Scopus, Google Scholar and World Health Organization Library were searched. The inclusion criteria were all forms of published articles which investigated the coincidence of disasters and COVID-19 pandemic. Using the title and abstract screening, the selections of studies were performed by two researchers. Once, the relevant papers were finalized, the analysis was done in two parts of descriptive analysis and implications for health systems. RESULTS: Out of 1245 studies generated by initial search, a number of 13 articles was selected for final analysis. Earthquake was the most frequent disaster which its coincidence with COVID-19 was studied by researchers (31%). The implications of researchers for healthcare system were explained in three sections of climatic events, earthquakes and all hazard approach in relation to COVID-19. CONCLUSION: Extracting the lessons learned from the regions affected by disasters at the time of COVID-19 pandemic can be helpful for healthcare professionals and policy-makers to improve their preparedness and response during disasters and a serious pandemic such as COVID-19. Further research is needed to identify the factors which strengthen the preparedness of health system for the dual risk of natural hazards and pandemics.

A model to explain road traffic data collection and registry in Iran: a grounded theory.

BACKGROUND: Sufficient data should be gathered and analyzed to increase awareness and attention of the community and policymakers in the field of road traffic injury (RTI) prevention. While various organizations and stakeholders are involved in road traffic crashes, there is no clear lead agency for data collection system in RTIs. Exploring stakeholders' perspective is one of the key sources for understanding this system. The purpose of this study is to identify the process of RTI data collection system based on stakeholders' experience. METHODS: This qualitative study was conducted employing grounded theory approach since September 2017 to December 2018 in Iran. Participants in this study were the authorities of the Emergency organizations, police, Ministry of Health and Medical Education, faculty members, as well as executive staff and road users who were involved in collecting and recording data (n=15). Data collection was carried out through face-to-face interviews using purposeful and theoretical sampling. Data analysis was performed based on Strauss and Corbin 2008. RESULTS: The core category was identified as "separated registration" explaining the process of collecting and recording road traffic injury data. Other variables obtained using the Strauss and Corbin Paradigm model were categorized as context, casual, intervening, strategies, and outcomes factors. The findings were classified into five groups including lack of trust in road safety promotion, process factors, management and organizational factors, failure of quality assurance, and administrative and organizational culture. CONCLUSIONS: The most important theory is "separated registration" and non-systematic registry system of road traffic injury data which is shown in a conceptual model. The findings of this study will help policymakers for better understanding the collecting and recording of RTI information.

An innovative index for assessing vulnerability of employees of different occupations from the COVID-19 pandemic in Iran.

The vulnerability of employees of different occupations from the Coronavirus disease 2019 (COVID-19) pandemic in Iran was assessed using an innovative index. The vulnerability index was developed in five steps as follows: (1) determining the principles and components of employees' susceptibility and resilience, (2) weighting the principles and components, (3) converting the levels of components to the sub-index values, (4) introducing the aggregation functions, and (5) characterizing the vulnerability index values in five categories as very high (80-100), high (65-79), medium (50-64), low (30-49), and very low (0-29). The average values of susceptibility, resilience, and vulnerability index of the employees were determined to be 35.2 ± 15.0, 73.9 ± 17.0, and 32.9 ± 12.7, respectively. The average resilience of the employees was more desirable than their average susceptibility. The distribution of the employees into the vulnerability index categories was 46.3% for very low, 41.9% for low, 3.6% for medium, and 8.2% for high. The worst cases of susceptibility and resilience principles were exposure to contaminated surfaces (59.1 ± 22.8) and top management commitment (66.6 ± 23.1). The elderly staff (especially over 50 years old), employees with low education levels, and employees in private and self-employment sectors were significantly more vulnerable (p value < 0.01) from the COVID-19 pandemic. The principles with significant incremental effects on the vulnerability index (p value < 0.05) were respectively top management commitment (+1.78), exposure to COVID-19 patients at work (+1.36), exposure to contaminated surfaces (+0.82), installing clear shields and wearing PPE (+0.59), observance of social distancing (+0.48), and just culture (+0.22). An especial plan to support the more vulnerable employees with an emphasis on the principles with the most incremental effects on the vulnerability index can efficiently control the inequality between the employees as well as occupational transmission of the COVID-19 in Iran.

Comparison of the appendicitis inflammatory response and Alvarado scoring systems in the diagnosis of acute appendicitis in children.

Our objective was to compare the diagnostic accuracy of Alvarado and appendicitis inflammatory response (AIR) scoring systems among children suspected of acute appendicitis concerning their postoperative outcomes. During a two-year period, a prospective multicentric study was carried in the selected hospitals of Iran. All children who were admitted with the diagnosis of acute appendicitis were enrolled in the study. However, patients suffering from generalized peritonitis or those who had a history of abdominal surgery were excluded. Before decision-making, each patient's score according to two appendicitis scoring systems was calculated. The clinical outcomes and diagnosis of patients were then compared to the results of each scoring system. For those patients who were a candidate for surgery, the final diagnosis of acute appendicitis was made by histopathology. Patients were divided into a high- and low-risk group according to scoring systems outcomes. Among the patients with a low score for appendicitis, the AIR scoring system had a sensitivity and specificity of 95% and 74%, respectively, which was more promising in comparison to that of the Alvarado system (90% and 70%, respectively). Regarding the patients at higher risk of acute appendicitis, none of the scoring systems provided reliable results since both systems showed sensitivity and specificity of less than 50%, which was not sufficient to distinguish patients who are a candidate for surgery. AIR and Alvarado scoring systems are not accurate models to predict the risk of acute appendicitis among children; however, the AIR system could be used as a reliable material to rule out the acute appendicitis diagnosis.

The effect of early tranexamic acid on bleeding, blood product consumption, mortality and length of hospital stay in trauma cases with hemorrhagic shock: a randomized clinical trial.

Introduction: Because no medication has been approved for coagulation support in trauma, the current study was aimed to evaluate the effectiveness of intravenous injection of Tranexamic acid (TXA) in patients with acute traumatic bleeding. Methods: In the current randomized controlled clinical trial, 68 patients with acute bleeding and hemorrhagic shock presentation due to blunt trauma of the abdomen, pelvis, and thorax, randomly assigned into two groups of TXA and placebo. Results: There was no statistically significant difference between the two groups in terms of Systolic blood pressure, pulse rate, Base excess, serum hemoglobin changes, bleeding volume, the incidence of thrombotic events, and the number of deaths (p > 0.05). But Systolic blood pressure, pulse rate, base excess, and serum hemoglobin, changed significantly within each group over time(p < 0.05). The median time for the length of hospital stay among the TXA group was lower than the Placebo group (6 days vs 10 days, p = 0.004). Also, there was a significant difference between the two groups about the median of pack cell, Platelet consumption, and bleeding Volume (p < 0.05). Conclusion: The use of TXA is associated with lower use of blood production and reduced length of hospital stay, however, thrombotic events incidence and mortality rates between the TXA and placebo groups were not different.

High-contrast optical microscopy of graphene sheets.

In the way of making graphene an industry-friendly material, it must be mass-produced with high-quality and reduced cost over large areas. Assisted by machine-learning techniques, rapid, nondestructive and accurate determination of large graphene sheets on SiO2 /Si substrates has been made possible in recent years by the optical microscopy method. Optimization of the substrate to achieve the maximum contrast can further extend the application of the optical microscopy method for quality control of the mass-produced graphene. Graphene/n2 /n3 three-layer structures, where n2 and n3 are refractive indices, are routinely used for identifying the number of graphene layers by optical reflection microscopy. In this paper, two analytical equations are derived that can be easily used for high-contrast optical imaging of graphene sheets without any need to resort to the cumbersome numerical methods. One of the equations is derived for choosing the best material with refractive index n2 that when coated on a substrate with refractive index n3 , maximizes the optical contrast. The other equation is derived for finding the best thickness of the SiO2 layer in graphene/SiO2 /Si structures, which are in common use for fabrication of graphene-based devices. The results are implemented in a MATLAB GUI, see Supporting Information, to assist the users in using the equations.

A New Optical Method for Online Monitoring of the Light Dose and Dose Profile in Photodynamic Therapy.

BACKGROUND AND OBJECTIVES: Photodynamic therapy (PDT) has gained widespread popularity in the last decades because of its distinctive advantages over the other commonly used cancer treatments. PDT dosimetry is a crucial factor in achieving a good optimization of PDT treatment planning. PDT dosimetry is a complex task since light dose as well as photosensitizer and oxygen concentrations in tissue need to be measured (ideally continuously) to be able to fully characterize the biological response. Light dose in PDT is routinely measured by the optical fibers that provide dose data at a limited number of discrete points and are not able to capture spatial dose profiles. The objective of this study is to propose and develop a new optical method for online monitoring of the dose profile data for PDT. STUDY DESIGN/MATERIALS AND METHODS: Using the digital holography technique, first, the general sketch of an experimental setup for PDT light dosimetry is provided. The theory behind the proposed method for using the experimental setup in PDT light dosimetry is fully described, and its limits of validity are determined. In a proof of principle study, the ability of the method for online monitoring of the absorbed light dose profile in PDT is evaluated by a simple experimental setup. RESULTS: The experimental results confirm the usefulness of the proposed method in providing continuous online dose profiles. The absorbed light dose profiles from an infrared light source in a quartz cell containing water are measured and shown. The depth-dose curves are extracted and it is shown that how these dosimetric data can be used for assisting the physicians in determining the appropriate spatiotemporal characteristics for treating the infected tissues and solid tumors with the required light dose amounts. A conversion relation is also derived for transforming the measured light dose with the proposed method to the most frequently used dose values by PDT practitioners, in terms of light power per square area. CONCLUSIONS: There is no restriction in using the method with other commonly used light sources in PDT, like light-emitting diodes and filtered lamps, with different wavelengths in visible or infrared regions of the spectrum. More complex experimental setups can be used in future studies to study the role of accumulated photosensitizers in malignant tissues. The proposed method in this study can also be used for light dose monitoring in other biomedical applications, where light is used for treating special diseases, and patients must receive sufficient amounts of light dose. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Comparison of Honey versus Polylactide Anti-Adhesion Barrier on Peritoneal Adhesion and Healing of Colon Anastomosis in Rabbits.

BACKGROUND: Postoperative adhesion is still a consequence of intra-abdominal surgeries, which results in bowel obstruction and abdominopelvic pain. Bowel anastomosis as a common abdominal surgery has the incidence of leakage in up to 30% of patients that increase morbidity and mortality. Due to similar pathways of adhesion formation and wound healing, it is important to find a way to reduce adhesions and anastomosis leakage. AIM: This study was designed to compare antiadhesive as well as anastomosis healing improvement effect of honey and polylactide anti-adhesive barrier film. METHODS: Forty-five rabbits divided into three groups of honey, adhesion barrier film, and control group in an animal study. Under a similar condition, rabbits underwent resection and anastomosis of cecum under general anaesthesia. In the first group, honey was used at the anastomosis site, in the second one polylactide adhesion barrier film utilised, and the third one was the control group. Adhesion, as well as anastomosis leakage, was assessed after 21 days. Data were analysed using the Statistical Package for Social Scientists (SPSS) for Windows version 25. RESULTS: Three groups of 15 rabbits were studied. The results showed that mean peritoneal adhesion score (PAS) was lower in the honey group (1.67) in comparison to the adhesion barrier film group (3.40) and the control group (6.33). CONCLUSION: Bio-absorbable polylactide barrier has an anti-adhesion effect but is not suitable for intestinal anastomosis in rabbits. Further studies needed to evaluate these effects on human beings.