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.

Wavelet threshold based on Stein's unbiased risk estimators of restricted location parameter in multivariate normal.

In this paper, the problem of estimating the mean vector under non-negative constraints on location vector of the multivariate normal distribution is investigated. The value of the wavelet threshold based on Stein's unbiased risk estimators is calculated for the shrinkage estimator in restricted parameter space. We suppose that covariance matrix is unknown and we find the dominant class of shrinkage estimators under Balance loss function. The performance evaluation of the proposed class of estimators is checked through a simulation study by using risk and average mean square error values.

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 with 10 - 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.

Acute Hepatic Allograft Rejection in Pediatric Recipients: Independent Factors.

BACKGROUND: Acute cellular rejection (ACR) has a reversible effect on graft and its survival. OBJECTIVE: To evaluate the relation between ACR and clinical factors in recipients of liver transplant allografts. METHODS: 47 consecutive liver recipients were retrospectively studied. Their data were extracted from records and analyzed. RESULTS: 38 (81%) of the 47 recipients experienced ACR during a 24-month follow-up. The rate of rejection was associated with none of the studied factors-recipient's blood group, sex, age, familial history of disease, drugs and blood products received, type of donor, and Child score and class. 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.

Predictive factors of death in patients with tuberculosis: a nested case-control study.

Tuberculosis is one of the main causes of death worldwide. This study aimed to determine predictive factors for death in patients with tuberculosis to set priorities for public heath interventions to reduce mortality in these patients. This nested case-control study was carried out in Mazandaran province of Islamic Republic of Iran among tuberculosis patients who were treated during 2002-2009. Each deceased patient was individually matched with a control patient according to sex, age, area of involvement and time of follow-up. Potential risk factors for death were evaluated using multivariate conditional logistic regression models. From 2206 patients 376 cases and 376 matched controls were selected. Only positive serology for HIV (OR = 19.1), history of kidney disease (OR = 6.81) and use of immunosuppressant drugs (OR = 3.96) significantly increased the risk of death in tuberculosis patients. These potentially modifiable risk factors could be taken into account in preventive interventions for tuberculosis patients in our country.

Predictive factors of death in patients with tuberculosis:a nested case-control study

Tuberculosis is one of the main causes of death worldwide. This study aimed to determine predictive factors for death in patients with tuberculosis to set priorities for public heath interventions to reduce mortality in these patients. This nested case–control study was carried out in Mazandaran province of Islamic Republic ofIran among tuberculosis patients who were treated during 2002–2009. Each deceased patient was individually matched with a control patient according to sex, age, area of involvement and time of follow-up. Potential risk factors for death were evaluated using multivariate conditional logistic regression models. From 2206 patients 376 cases and 376 matched controls were selected. Only positive serology for HIV (OR = 19.1), history of kidney disease (OR = 6.81) and use of immunosuppressant drugs (OR = 3.96) significantly increased the risk of death in tuberculosis patients. These potentially modifiable risk factors could be taken into account in preventive interventions for tuberculosis patients in our country.

La tuberculose est l'une des principales causes de décès dans le monde. La présente étude avait pour objectif de déterminer les facteurs prédictifs de décès chez des patients atteints de tuberculose afin de fixer des priorités pour les interventions de santé publique visant à réduire la mortalité chez ces patients. Laprésente étude cas-témoin nichée dans une cohorte a été menée dans la province de Mazandaran (République islamique d’Iran) auprès de patients tuberculeux ayant été traités entre 2002 et 2009. Chaque patient décédé a été individuellement apparié à un patient témoin pour le sexe, l'âge et le site de la lésion ainsi que la période de suivi. Des facteurs de risque potentiels de décès ont été évalués à l'aide de modèles de régression logistique conditionnelle multivariée. Sur un total de 2206 patients, 376 cas et 376 témoins appariés ont été sélectionnés. Seuls une sérologie positive pour le VIH (OR = 19,1), des antécédents d'insuffisance rénale (OR = 6,81) et le recours à des immunosuppresseurs (OR = 3,96) augmentaient ignificativement le risque de décès chez ces patients atteints de tuberculose. Ces facteurs de risque potentiellement modifiables pourraient être pris en compte dans des interventions préventives visant les patients atteints de tuberculose dans notre pays.

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.

New infrared bands of nonpolar OCS dimer and experimental frequencies for two intermolecular modes.

Spectra of the nonpolar carbonyl sulfide dimer in the region of the OCS ν(1) fundamental band were observed in a slit-jet supersonic expansion. The jet was probed using radiation from a tunable diode laser employed in a rapid-scan signal averaging mode. Six new bands were observed and analyzed, all of which originate from the dimer ground vibrational state. Three were vibrational fundamentals involving the ((18)OCS)(2) and (16)OCS-(18)OCS isotopologues. They enabled an estimate to be made of the frequency of the infrared-forbidden mode corresponding to in-phase vibration of the OCS monomers in the dimer, a value needed to obtain an intermolecular vibrational frequency from one of the observed combination bands. A relatively weak b-type dimer band centered at 2103.105 cm(-1) was assigned to the OCS 4ν(2) (l = 0) bending overtone. Combination bands were observed involving the geared bend and van der Waals stretch intermolecular modes. The resulting experimental frequencies of 37.5(20) cm(-1) for the bend and 42.9727(1) cm(-1) for the stretch are in good agreement with a recent high level theoretical calculation.

Assessment of mutations in the Best macular dystrophy (VMD2) gene in patients with adult-onset foveomacular vitelliform dystrophy, age-related maculopathy, and bull's-eye maculopathy.

PURPOSE: To study the presence of Best macular dystrophy (VMD2) gene mutations in patients diagnosed with maculopathies other than classic Best disease and to describe the clinical characteristics of these subjects. DESIGN: Case-comparison study of phenotype-genotype correlations. METHODS: Patients with either age-related maculopathy (ARM; n = 259) or maculopathies other than classic Best disease (n = 28) were screened for mutations in the Best gene (VMD2; OMIM 153700). These cases were compared with ethnically similar subjects in the same age range without maculopathy (n = 196). All patients underwent a complete dilated ocular examination, and all affected individuals underwent fundus photography. Phenotype-genotype comparisons were made. MAIN OUTCOME MEASURES: Presence of mutations in the Best gene (VMD2; OMIM 153700) and the clinical phenotype. RESULTS: Three of 259 patients (1%) with ARM and 2 of 28 patients (7%) with other maculopathies including 1 of 3 patients with adult-onset foveomacular vitelliform dystrophy and 1 of 5 patients with a bull's eye maculopathy, but none of the controls, were found to possess amino acid-changing variants in the VMD2 gene. These included a man with confluent drusen and retinal pigment epithelial detachments (variant in exon 6; T216I), a man with geographic atrophy and numerous soft drusen (variant in exon 10; L567F), a woman with drusen and retinal pigment epithelial alterations (variant in exon 10; L567F), a woman with drusen and retinal pigment epithelial alterations resembling bull's-eye maculopathy (variant in exon 4; E119Q), and a woman diagnosed with adult-onset foveomacular vitelliform dystrophy (variant in exon 4; A146K). CONCLUSIONS: Novel mutations in the VMD2 gene were found in patients diagnosed with maculopathies other than classic Best disease. Some cases diagnosed as adult-onset vitelliform foveomacular dystrophy may represent a variant of Best disease with delayed onset. The VMD2 gene does not play a major role in the development of ARM.

Inflammatory conditions of the eye associated with rheumatic diseases.

Ocular inflammation occurs in many patients with systemic rheumatic disease. The best examples are rheumatoid arthritis, juvenile rheumatoid arthritis, temporal arteritis, systemic lupus erythematosus, Wegener's granulomatosis, polyarteritis nodosa, relapsing polychondritis, and Adamantiades-Behçet's disease. Ocular inflammation may precede the symptoms of the systemic disease and can be helpful in systemic diagnosis. After diagnosis, ocular inflammation can mark the severity of the systemic condition. Thus, prompt diagnosis and treatment of inflammatory conditions of the eye are warranted and may be sight- and life-saving.

Survey of patients with granular, lattice, avellino, and Reis-Bücklers corneal dystrophies for mutations in the BIGH3 and gelsolin genes.

OBJECTIVES: To search for novel mutations that cause corneal stromal dystrophies and to confirm or revise the clinical diagnosis of patients with these mutations. PATIENTS: Through review of the records of the Cogan Eye Pathology Laboratory at the Massachusetts Eye and Ear Infirmary, Boston, and of clinical records, we ascertained 14 unrelated patients with the clinical or histopathologic diagnosis of granular (3 cases), Avellino (5 cases), lattice (5 cases), or Reis-Bücklers (1 case) corneal dystrophy. METHODS: Clinical records and histopathologic findings of the index patients and their relatives were reviewed. Patients and selected relatives donated a blood sample from which leukocyte DNA was purified and assayed for mutations in the BIGH3 gene and, in 2 patients, the gelsolin gene, using the polymerase chain reaction and direct genomic sequencing. RESULTS: All index patients with the diagnosis of granular dystrophy or Avellino dystrophy had the missense mutation Arg555Trp or Arg124His, respectively, previously reported in the BIGH3 gene. Of the 5 index patients with a prior diagnosis of lattice dystrophy, 2 had the originally reported lattice mutation (Arg124Cys) in the BIGH3 gene, 1 had a more recently reported missense mutation (His626Arg) in the same gene, 1 had the missense mutation Asp187Asn in the gelsolin gene, and 1 had no detected mutation in either gene. Affected members of the family with Reis-Bücklers dystrophy did not carry the previously reported mutations Arg555Gln or Arg124Leu but instead carried a novel missense mutation Gly623Asp in the BIGH3 gene. CONCLUSIONS: Molecular genetic analysis can improve the accuracy of diagnosis of patients with corneal dystrophies. Two patients with a prior diagnosis of lattice corneal dystrophy had their diagnosis changed to gelsolin-related amyloidosis (1 case) or secondary, nonhereditary localized amyloidosis (1 case). A novel mutation in the BIGH3 gene that causes Reis-Bücklers dystrophy was uncovered through this analysis, and another recently reported novel mutation was encountered. These findings serve to expand our knowledge of the spectrum of pathogenic mutations in BIGH3.