The role of collisional ionization in heavy ion acceleration by high intensity laser pulses

We present here simulation results of the laser-driven acceleration of gold ions using the EPOCH code. Recently, an experiment reported the acceleration of gold ions up to 7 MeV/nucleon with a strong dependency of the charge-state distribution on target thickness and the detection of the highest charge states [Formula: see text]. Our simulations using a developmental branch of EPOCH (4.18-Ionization) show that collisional ionization is the most important cause of charge states beyond Z = 51 up to He-like Au.

Real-Time Electron Solvation Induced by Bursts of Laser-Accelerated Protons in Liquid Water

Understanding the mechanisms of proton energy deposition in matter and subsequent damage formation is fundamental to radiation science. Here we exploit the picosecond (10^{-12}  s) resolution of laser-driven accelerators to track ultrafast solvation dynamics for electrons due to proton radiolysis in liquid water (H_{2}O). Comparing these results with modeling that assumes initial conditions similar to those found in photolysis reveals that solvation time due to protons is extended by >20  ps. Supported by magnetohydrodynamic theory this indicates a highly dynamic phase in the immediate aftermath of the proton interaction that is not accounted for in current models.

Relationship between blood group and risk of infection and death in COVID-19: a live meta-analysis

The relationship between ABO blood group and the incidence of coronavirus disease 2019 (COVID-19) infection and death has been investigated in several studies. The reported results were controversial, so the objective of the present study was to assess the relationship between different blood groups and the onset and mortality of COVID-19 infection using a meta-analysis method. We searched relevant databases using appropriate MeSH terms. We screened articles on the bases of titles, abstracts and full text, and articles that met the inclusion criteria were selected. Quality assessment was done with the Newcastle-Ottawa scale checklist. The estimated frequency of COVID-19 infection and death in terms of ABO blood group and the overall estimate of the odds ratio between blood group with COVID-19 infection and death was calculated with 95% confidence interval. The pooled frequency of blood groups A, B, O and AB among COVID-19-infected individuals was estimated as 36.22%, 24.99%, 29.67% and 9.29% respectively. The frequency of blood groups A, B, O and AB among patients who died of COVID-19 infection was estimated as 40%, 23%, 29% and 8% respectively. The odds ratio of COVID-19 infection for blood group A versus the other blood groups was estimated as 1.16 (95% confidence interval (CI), 1.02-1.33). The corresponding figures for blood groups O and AB versus other blood groups were estimated as 0.73 (95% CI, 0.60-0.88) and 1.25 (95% CI, 0.84-1.86) respectively. This meta-analysis showed that individuals with blood group A are at higher risk for COVID-19 infection while those with blood group O are at lower risk. Although the odds ratio of death for AB blood group was nonsignificant, it was considerable.

Time-resolved diffraction with an optimized short pulse laser plasma X-ray source

We present a setup for time-resolved X-ray diffraction based on a short pulse, laser-driven plasma X-ray source. The employed modular design provides high flexibility to adapt the setup to the specific requirements (e.g., X-ray optics and sample environment) of particular applications. The configuration discussed here has been optimized toward high angular/momentum resolution and uses K α -radiation (4.51 keV) from a Ti wire-target in combination with a toroidally bent crystal for collection, monochromatization, and focusing of the emitted radiation. 2 × 10 5 Ti-K α1 photons per pulse with10 - 4 relative bandwidth are delivered to the sample at a repetition rate of 10 Hz. This allows for the high dynamic range (104) measurements of transient changes in the rocking curves of materials as for example induced by laser-triggered strain waves.

Acute Hepatic Allograft Rejection in Pediatric Recipients: Effective Factors

BACKGROUND

Acute cellular rejection (ACR), a reversible process, can affect the graft survival.

OBJECTIVE

To evaluate the relation between ACR and clinical factors in recipients of allograft liver transplantation.

METHODS

47 recipients of liver were consecutively enrolled in a retrospective study. Their information were retrieved from their medical records and analyzed.

RESULTS

Of the 47 recipients, 38 (81%) experienced acute rejection during 24 months of the transplantation. None of the studied factors for occurring transplant rejection, i.e., blood groups, sex, age, familial history of disease, receiving drugs and blood products, type of donor, Child score, and Child class, was not found to be significant.

CONCLUSION

During a limited follow-up period, we did not find any association between ACR and suspected risk factors.

Prevalence of Non-alcoholic Fatty Liver Disease and Its Related Factors in Iran

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease in developing and developed countries. Estimating the total prevalence of NAFLD by means of appropriate statistical methods can provide reliable evidence for health policy makers.

OBJECTIVE

To determine the prevalence of NAFLD in Iran using a systematic review and meta-analysis.

METHODS

We identified relevant studies by searching national and international databases. Standard error of the prevalence reported in each study was calculated assuming a binomial distribution. The heterogeneity between the results of the studies was determined using Cochran's Q and I square indices. We used a random effect model to combine the prevalence rates reported in the studies.

RESULTS

We entered 23 eligible studies in this systematic review investigated NAFLD among 25,865 Iranian people. The total prevalence of NAFLD, prevalence of mild, moderate and severe fatty liver disease were estimated at 33.9% (95% CI 26.4%-41.5%), 26.7% (95% CI 21.7%-31.7%), 7.6% (95% CI 5.7%-9.4%), and 0.5% (95% CI 0.1%-0.9%), respectively. The majority of studies reported that NAFLD was more common among men (seven of eight studies), obese person (15 of 15 studies), older people (10 of 10 studies), patients with systolic hypertension (5 of 8 studies), patients with diastolic hypertension (7 of 9 studies), patients with hypertriglyceridemia (14 of 16 studies), patients with high HOMA level (4 of 4 studies), patients with metabolic syndrome (4 of 4 studies), and those with elevated serum ALT (8 of 12 studies).

CONCLUSION

Our study showed that the prevalence of NAFLD in Iran was relatively high and male gender, old age, diabetes, metabolic syndrome, systolic/diastolic hypertension, high serum ALT, and hypertriglyceridemia may be determinants of NAFLD.

The trend of governmental support from post-graduated Iranian students in medical fields to study abroad

BACKGROUND

To explore the trend and composition of post-graduate Iranian students who received governmental scholarship during the last two decades.

METHOD

Detailed information about the awarded scholarships and also about the number of post graduate students in clinical and basic sciences in domestic universities were collected from the related offices within the ministry of health and medical education and their trends were triangulated.

RESULTS

A sharp drop was observed in the number of awarded scholarships, from 263 in 1992 to 46 in 2009. In the beginning, almost all of scholarships fully supported students for a whole academic course; while in recent years most of scholarships supported students for a short fellowship or complementary course (more than 80%). Students studied in a wide range of colleges within 30 countries; more than 50% in Europe. Although one third of students studied in UK in the first years, only 4% of students selected this country in recent years. conversely, the number of scholarships to Germany and sweden have increased more than 10 and 3 times during this period. In parallel, the capacity of domestic universities for training of post-graduate students has been expanded dramatically.

CONCLUSION

Although expanding post-graduate education has been one of the main strategic objectives of the ministry of health and medical education in last two decades, it was obtained using different approaches. By time, more attention was to expanding the capacities of Iranian universities, and choosing less but more targeted students to continue their studies abroad.

Coronary Artery Disease Risk Factors in an Urban and Peri-urban Setting, Kerman, Southeastern Iran (KERCADR Study): Methodology and Preliminary Report

BACKGROUND

This article was to present the sampling and measurements methods and the main preliminary findings of the KERCADR cohort study (first round) in an urban and peri-urban setting, Kerman, southeastern Iran 2009-11.

METHOD

5900 (3238 female) people aged between 15 to 75 years were recruited in the household survey by non-proportional to size one-stage cluster sampling. Trained internal specialists, general practitioners, clinical psychologists and dentists have assessed the study subjects by person-assisted questionnaires regarding different NCD risk factors including cigarette and opium smoking, physical activity, nutrition habits, anxiety, depression, obesity, hypertension and oral health. Blood samples were also collected for determining FBS, HbA1c, cholesterol and triglyceride. Weighted standardized prevalence estimates were calculated by STATA 10 survey analysis package.

RESULTS

The participation rate was more than 95% in all subgroups. Cigarette smoking (18.4% vs. 1.2%), opium use (17.8% vs. 3.0%) and triglyceridemia (16.1% vs. 12.0%) were significantly higher among men than women. In contrast, women were presented with higher level of sever anxiety (29.1% vs. 16.7%), obesity (16.8% vs. 9.2%), low-physical activity (45.1% vs. 39.2%) and uncontrolled diabetes (60.2% vs. 31.0%). More than 68% of all subjects have presented with moderate to severe gingival index scores.

CONCLUSION

The first round of the KERCADR cohort with sufficient sample size and response rate provided precise estimates for the main clinical and para-clinical NCD risk factors. These evidences need to be translated into public health interventions and monitored in the next rounds of the cohort.

Measurement of ejection fraction by thermal dilution techniques

The reproducibility, accuracy, and clinical applicability of ventricular ejection fraction derived by a thermal dilution technique were assessed in 22 dogs and 18 patients. Results obtained by the thermal technique were compared to simultaneous results obtained by radionuclide angiography. Right ventricular ejection fraction, measured in 9 dogs (1014 determinations) and 8 patients (744 determinations) was reproducible +/- 5%. Left ventricular ejection fraction, measured in 10 patients, was reproducible +/- 5%. Correlation between thermal and radionuclear measurements varied from 0.86 to 0.93 (all P less than 0.02). We conclude that, because of its low cost, ease of use, and accuracy, thermally derived ejection fraction determinations can be helpful in hemodynamic monitoring of critically ill patients.