Study of the systematic fully grouted rock bolts performance in tunnels considering installation condition of bolt head

A two-dimensional parametric numerical study is conducted to investigate some unknown aspects of the systematic fully grouted rock bolts performance in the stability of tunnels. The influence of the bolt head constraint conditions, i.e. a stiff steel plate on a smooth rigid basement or a rough basement (the rigid and flexible complexes, respectively) on the convergence confinement, development of the plastic band, and the maximum bolt force is studied in a tunnel located at a poor or good rock mass quality. As well, the difference of the tunnel convergence on the bolt head location and in the middle between the two bolts is the other investigated parameter. The results show that for a tunnel excavated in a poor rock mass quality at great depths (very squeezing condition), the difference of convergences must be considered, particularly for large openings in which the spacing of the bolts is not small

A generalized mechanistic codon model.

Models of codon evolution have attracted particular interest because of their unique capabilities to detect selection forces and their high fit when applied to sequence evolution. We described here a novel approach for modeling codon evolution, which is based on Kronecker product of matrices. The 61 × 61 codon substitution rate matrix is created using Kronecker product of three 4 × 4 nucleotide substitution matrices, the equilibrium frequency of codons, and the selection rate parameter. The entities of the nucleotide substitution matrices and selection rate are considered as parameters of the model, which are optimized by maximum likelihood. Our fully mechanistic model allows the instantaneous substitution matrix between codons to be fully estimated with only 19 parameters instead of 3,721, by using the biological interdependence existing between positions within codons. We illustrate the properties of our models using computer simulations and assessed its relevance by comparing the AICc measures of our model and other models of codon evolution on simulations and a large range of empirical data sets. We show that our model fits most biological data better compared with the current codon models. Furthermore, the parameters in our model can be interpreted in a similar way as the exchangeability rates found in empirical codon models

Performance of segmental and shotcrete linings in shallow tunnels crossing a transverse strike-slip faulting

In this paper, three-dimensional numerical modeling is performed to study the effects of strike-slip fault movement on the performance of shotcrete and segmental linings in shallow tunnels that transversely cross the fault. For this purpose, a parametric study is conducted on lining thickness, soil geo-mechanical properties, tunnel depth, and fault dip angle to assess their influence on the tunnel movements and deformation. A comparison between the segmental and the shotcrete tunnels is made to highlight their performance. The results show that the greater strike-slip fault dip angle increases the separation of the lining segments. As well, after faulting, the maximum tunnel displacement in denser soils is greater than in loose soils

Intensive Care Nurses' Knowledge of Radiation Safety and Their Behaviors Towards Portable Radiological Examinations

Background: Radiological examinations for patients who are hospitalized at intensive care units are usually performed using portable radiography devices. However they may require knowledge and safety precautions of nurses. Objectives: The aim of the study was to investigate ICU nurses’ knowledge of radiation safety and their behaviors towards portable radiological examinations. Materials and Methods: In total, 44 intensive care nurses were recruited for this cross-sectional descriptive study using census sampling during April and May 2014. The study setting was at intensive care units of Shahid Beheshti Hospital of Kashan, Iran. An eleven-item questionnaire and a five-item checklist were used for evaluating nurses’ radiation protection knowledge and behaviors, respectively. An expert panel consisting of ten nursing and radiology faculty members confirmed the content validity of the questionnaire and the checklist. Moreover, a Geiger-Müller counter was used for measuring ionizing radiation during portable radiological examinations. Study data were analyzed using the SPSS software version 13.0. Mean, standard deviation, frequency and one-sample t test were used for description of the data. The level of significance was set at below 0.05. Results: The mean of participants’ radiation protection knowledge was 4.77 ± 1.38. The most prevalent radiation protection behavior of nurses was leaving the intensive care unit during portable radiological examinations. Only 6.8% of nurses stayed at the nursing station during radiological examinations. The highest dose of radiation was 0.11 micro Sievert per hour (μSv/h), which was much lower than the highest permitted level of radiation exposure i.e. 0.25 μSv/h. Conclusions: Portable radiological examinations did not expose healthcare providers to high doses of ionizing radiation. Nurses’ radiation protection knowledge was limited and hence, they require in-service education programs

First report of Ancylostoma tubaeforme in Persian Leopard (Panthera pardus saxicolor)

Ancylostoma tubaeforme was originally described as a separate species parasitizing the cat. The adults of A. tubaeforme are 7 to 12 mm long. A. tubaeforme can be differentiated from the adults of A. braziliense and A. ceylanicum by the presence of three teeth. Here we describe the first report of A. tubaeforme in a Persian young female leopard, 2–3 years old, with head and trunk length 120 centimeters, length of tail 98 centimeters and body weight 35 kilograms

Predictive value of transcutaneous bilirubinometry on third day of birth in diagnosis of hyperbilirubinemia in term and near-term neonates

Introduction: Severe hyperbilirubinemia may cause side effects such as hearing impairment or bilirubin encephalopathy. In this way, transcutaneous bilirubinometry (TCB) is a non-invasive screening method, which is performed using BiliCheck and does not require frequent blood sampling, time and cost. The aim of this study was to determine the predictive value of TCB on third day of birth in neonatal hyperbilirubinemia diagnosis in term and near-term neonates. Materials and Methods: A test assessment method was chosen with continuous sampling in 388 neonates 35 weeks and more at AkabarAbadi hospital in Tehran in 2011. On the third day of birth, cutaneous bilirubin levels (TCB) in the forehead by using BiliCheck and serum bilirubin (TSB) was measured from the heel capillary sample and consequently were compared with each other. Results: In neonatal hyperbilirubinemia diagnosis on the third day of birth, cutaneous bilirubin measurement had the sensitivity of 82 with the confidence interval (78.2, 85.7), specificity of 99.3 with the confidence interval (98.7, 99.9), positive predictive value of 92.9 with the confidence interval (88.0, 96.2) and negative predictive value of 94.8 with the confidence interval (92.8, 96.8). Generally, the third day measurement of cutaneous bilirubin had a predictive value of 94.5 in detecting high-risk neonates for hyperbilirubinemia. Conclusion: Third day TCB, in addition to being non-invasive and convenient use, has a high predictive value to detecting the risk of hyperbilirubinemia in neonate and it is recommended to use hyperbilirubinemia screening. © 2019, Semnan University of Medical Sciences. All rights reserved

Height and timing of growth spurt during puberty in young people living with vertically acquired HIV in Europe and Thailand.

OBJECTIVE: The aim of this study was to describe growth during puberty in young people with vertically acquired HIV. DESIGN: Pooled data from 12 paediatric HIV cohorts in Europe and Thailand. METHODS: One thousand and ninety-four children initiating a nonnucleoside reverse transcriptase inhibitor or boosted protease inhibitor based regimen aged 1-10 years were included. Super Imposition by Translation And Rotation (SITAR) models described growth from age 8 years using three parameters (average height, timing and shape of the growth spurt), dependent on age and height-for-age z-score (HAZ) (WHO references) at antiretroviral therapy (ART) initiation. Multivariate regression explored characteristics associated with these three parameters. RESULTS: At ART initiation, median age and HAZ was 6.4 [interquartile range (IQR): 2.8, 9.0] years and -1.2 (IQR: -2.3 to -0.2), respectively. Median follow-up was 9.1 (IQR: 6.9, 11.4) years. In girls, older age and lower HAZ at ART initiation were independently associated with a growth spurt which occurred 0.41 (95% confidence interval 0.20-0.62) years later in children starting ART age 6 to 10 years compared with 1 to 2 years and 1.50 (1.21-1.78) years later in those starting with HAZ less than -3 compared with HAZ at least -1. Later growth spurts in girls resulted in continued height growth into later adolescence. In boys starting ART with HAZ less than -1, growth spurts were later in children starting ART in the oldest age group, but for HAZ at least -1, there was no association with age. Girls and boys who initiated ART with HAZ at least -1 maintained a similar height to the WHO reference mean. CONCLUSION: Stunting at ART initiation was associated with later growth spurts in girls. Children with HAZ at least -1 at ART initiation grew in height at the level expected in HIV negative children of a comparable age

Antibodies from convalescent plasma promote SARS-CoV-2 clearance in individuals with and without endogenous antibody response

BACKGROUNDNeutralizing antibodies are considered a key correlate of protection by current SARS-CoV-2 vaccines. The manner in which human infections respond to therapeutic SARS-CoV-2 antibodies, including convalescent plasma therapy, remains to be fully elucidated. METHODSWe conducted a proof-of-principle study of convalescent plasma therapy based on a phase I trial in 30 hospitalized COVID-19 patients with a median interval between onset of symptoms and first transfusion of 9 days (IQR, 7-11.8 days). Comprehensive longitudinal monitoring of the virological, serological, and disease status of recipients allowed deciphering of parameters on which plasma therapy efficacy depends. RESULTSIn this trial, convalescent plasma therapy was safe as evidenced by the absence of transfusion-related adverse events and low mortality (3.3%). Treatment with highly neutralizing plasma was significantly associated with faster virus clearance, as demonstrated by Kaplan-Meier analysis (P = 0.034) and confirmed in a parametric survival model including viral load and comorbidity (adjusted hazard ratio, 3.0; 95% CI, 1.1-8.1; P = 0.026). The onset of endogenous neutralization affected viral clearance, but even after adjustment for their pretransfusion endogenous neutralization status, recipients benefitted from plasma therapy with high neutralizing antibodies (hazard ratio, 3.5; 95% CI, 1.1-11; P = 0.034). CONCLUSIONOur data demonstrate a clear impact of exogenous antibody therapy on the rapid clearance of viremia before and after onset of the endogenous neutralizing response, and point beyond antibody-based interventions to critical laboratory parameters for improved evaluation of current and future SARS-CoV-2 therapies. TRIAL REGISTRATIONClinicalTrials.gov NCT04869072. FUNDINGThis study was funded via an Innovation Pool project by the University Hospital Zurich; the Swiss Red Cross Glückskette Corona Funding; Pandemiefonds of the UZH Foundation; and the Clinical Research Priority Program "Comprehensive Genomic Pathogen Detection" of the University of Zurich

Swiss public health measures associated with reduced SARS-CoV-2 transmission using genome data

Genome sequences from evolving infectious pathogens allow quantification of case introductions and local transmission dynamics. We sequenced 11,357 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genomes from Switzerland in 2020 - the sixth largest effort globally. Using a representative subset of these data, we estimated viral introductions to Switzerland and their persistence over the course of 2020. We contrasted these estimates with simple null models representing the absence of certain public health measures. We show that Switzerland's border closures de-coupled case introductions from incidence in neighboring countries. Under a simple model, we estimate an 86-98% reduction in introductions during Switzerland's strictest border closures. Furthermore, the Swiss 2020 partial lockdown roughly halved the time for sampled introductions to die out. Last, we quantified local transmission dynamics once introductions into Switzerland occurred, using a phylodynamic model. We found that transmission slowed 35-63% upon outbreak detection in summer 2020, but not in fall. This finding may indicate successful contact tracing over summer before overburdening in fall. The study highlights the added value of genome sequencing data for understanding transmission dynamics