Breumavila7661
The toughening mechanism of cortical bone is closely related to its hierarchical microstructure. Osteon is the most important microstructure of cortical bone. Therefore, it is very important to study the toughening mechanism of the microstructure of osteon. There are three main kinds of cracks in cortical bone external crack of osteon, internal radial cracks of osteon and microporous damage cracks. Numerical models for these three kinds of cracks are established by XFEM and the progressive damage approach, respectively. The multi-toughening mechanisms of microstructure of osteon are found. The cement line on the outside of osteon is its first toughening mechanism, which can make the crack deflection and improve the fracture resistance of osteon. The resistance of cement line to fracture increases with the decrease of the strength and the increase of the thickness. The second toughening mechanism is elliptical osteocyte lacunae, which can attract the crack into the elliptical lacunae and cause stress redistribution to prevent the crack propagation. The annularly elliptical lacuna structure is an optimized arrangement and shape of microstructure, which is the third toughening mechanism of osteon. This microstructure can determine the location of the crack initiation and make the microcracks propagate along the annular direction rather than penetrating into the haversian cannal to protect the integrity of the osteon. The study of these toughening mechanisms provides new ideas for the research and design of synthetic composite structures.An Eye Tracking System (ETS) is used at CNAO for providing a stable and reproducible ocular proton therapy (OPT) set-up, featuring a fixation light (FL) and monitoring stereo-cameras embedded in a rigid case. The aim of this work is to propose an ETS set-up simulation algorithm, that automatically provides the FL positioning in space, according to patient-specific gaze direction and avoiding interferences with patient, beam and collimator. Two configurations are provided one in the CT room for acquiring images required for treatment planning with the patient lying on a couch, and one related to the treatment room with the patient sitting in front of the beam. Algorithm validation was performed reproducing ETS simulation (CT) and treatment (room) set-up for 30 patients previously treated at CNAO. The positioning accuracy of the device was quantified through a set of 14 control points applied to the ETS case and localizable both in the CT volume and in room X-ray images. Differences between the position of ETS reference points estimated by the algorithm and those measured by imaging systems are reported. The corresponding gaze direction deviation is on average 0.2° polar and 0.3° azimuth for positioning in CT room and 0.1° polar and 0.4° azimuth in the treatment room. The simulation algorithm was embedded in a clinically usable software application, which we assessed as capable of ensuring ETS positioning with an average accuracy of 2 mm in CT room and 1.5 mm in treatment room, corresponding to gaze direction deviations consistently lower than 1°.
To simulate radiofrequency (RF) burns that frequently occur at skin-skin and skin-bore wall contact points.
RF burn injuries (thumb-thigh and elbow-bore wall contacts) that typically occur on the lateral side of the body during 1.5T magnetic resonance imaging (MRI) scans were simulated using a computational human model. The model was shifted to investigate the influence of the position of the patient in an MRI scanner. The specific absorption rate (SAR), electric field, and temperature were mapped.
Regarding the contact points located near the edge of the birdcage transmission coil, under the allowable maximum RF power exposure i.e., the average whole-body SAR at the safety limit value (2W/kg), the 10-g-tissue-averaged SAR (SAR
) at those points significantly increased for both the thumb-thigh (180W/kg) and elbow-bore wall (48W/kg) cases. Both values significantly exceeded the highest safety limit of the partial-body SAR (10W/kg). The electric field, the square of which is proportional to SAR, was remarkably high near the edge of the birdcage transmission coil. The peak SAR
for each injury case was associated with contact-point peak temperatures that reached 52°C at approximately 1min following RF exposure onset; a 1-min period of exposure to this temperature causes a first-degree burn.
We demonstrated high heat generation in RF burn injury cases in silico. The RF heating occurring on the lateral side of the body was strongly dependent on the electric field distribution, which is dominantly determined by an RF transmission coil.
We demonstrated high heat generation in RF burn injury cases in silico. The RF heating occurring on the lateral side of the body was strongly dependent on the electric field distribution, which is dominantly determined by an RF transmission coil.Uranium (U) geochemistry and its isotopic compositions of reservoir sediments in U mine area were poorly understood. Herein, U and Th isotopic compositions were employed to investigate source apportionment and geochemical behavior of U in 41 reservoir sediments from a U mining area, Guangdong, China. The remarkably high contents of both total U (207.3-1117.7 mg/kg) and acid-leachable U (90.3-638.5 mg/kg) in the sediments exhibit a severe U contamination and mobilization-release risk. The U/Th activity ratios (ARs) indicate that all sediments have been contaminated apparently by U as a result of discharge of U containing wastewater, especially uranium mill tailings (UMT) leachate, while the variations of U/Th ARs are dominated by U geochemical behaviors (mainly redox process and adsorption). The U isotopic compositions (δ238U) showed a large variance through the sediment profile, varying from - 0.62 to - 0.04‰. The relation between δ238U and acid-leachable U fraction demonstrates that the U isotopic fractionation in sediments can be controlled by bedrock weathering (natural activity), UMT leachate (anthropogenic activity) and subsequent biogeochemical processes. The findings suggest that U-Th isotopes are a powerful tool to better understand U geochemical processes and enrichment mechanism in sediments that were affected by combined sources and driving forces.
Emerging evidence suggests the composition of local illicit drug markets varies over time and the availability and relative lethality of illicit drugs may contribute to temporal trends in overdose mortality. Law enforcement drug seizures represent a unique opportunity to sample the makeup of local drug markets. Prior research has associated shifts in the types of drugs seized and trends in unintentional drug overdose mortality. The present report builds on this work by demonstrating a novel methodology, the Street-Drug Lethality Index, which may serve as a low-lag predictor of unintentional overdose deaths.
Data included administrative records of law enforcement drug seizures and unintentional drug overdose deaths in Ohio from 2009 -to- 2018. Death records and lab results from drug seizures occurring during the calendar year 2017 were transformed via the described procedure to create lethality indices for individual drugs. These indices were then summed annually to create the independent variable for a linear regression model predicting unintentional overdose deaths for all years during the study period.
The regression model explained 93 % of the year-to-year variance in unintentional overdose fatalities (slope = 0.009480; CI = 0.007369 to 0.011590; t
= 10.355942; P = 0.000007; Y = 11.808982 + 0.009480X, r
= 0.931).
These findings contribute to a growing body of evidence that changes in the composition of the drug supply may predict trends in unintentional overdose mortality. The proposed methodology might inform future overdose prevention and response efforts as well as research.
These findings contribute to a growing body of evidence that changes in the composition of the drug supply may predict trends in unintentional overdose mortality. The proposed methodology might inform future overdose prevention and response efforts as well as research.
This study aimed to identify increases in 100 % alcohol-related death (ARD) and any differences among prefectures between 1995-2016.
Data from the national death registry on 100 % ARDs between 1995-2016 were extracted. Age-standardized mortality rate (ASMR) of 100 % ARD by year, gender, and gender ratio were calculated. After dividing the period into 1995-2005 and 2006-2016, the ASMRs of 100 % ARDs were calculated by prefecture. Additionally, based on geographical area, municipality size, or annual alcohol sales per adult in each prefecture, prefectures were divided into groups and analysed.
In total, 95,455 deaths were caused by 100 % ARD from 1995-2016. learn more Men's ASMRs of 100 % ARD markedly increased from 4.0 per 100,000 in 1995 to 5.2 between 2010 and 2013, and gradually declined to 5.0 in 2016. Women's ASMRs increased steadily from 0.3 in 1995 to 0.8 in 2016. The gender ratio of ASMRs decreased from 13.3 in 1995 to 6.3 in 2016. The ASMR of one prefecture, which had reduced alcohol tax rates, was higher for both genders. Both men's and women's ASMRs were higher in the prefectures that had higher alcohol sales (6.3 [5.0-7.7] and 0.8 [0.6-1.1], respectively) compared to the prefectures that had lower alcohol sales (4.3 [4.0-4.7] p < 0.001 and 0.6 [0.5-0.6] p = 0.045, respectively).
The ASMR of 100 % ARD remained high for men and increased for women, and prefecture-level higher alcohol sales and lower tax rates correlated with the higher mortality rate. Increasing prices and taxes and reducing alcohol sales may contribute to a decrease in alcohol-related mortality.
The ASMR of 100 % ARD remained high for men and increased for women, and prefecture-level higher alcohol sales and lower tax rates correlated with the higher mortality rate. Increasing prices and taxes and reducing alcohol sales may contribute to a decrease in alcohol-related mortality.
Assessment of genital-anal (GA) injuries following sexual assault promotes health and assists prosecutors to build a case. The pattern of injuries may help differentiate between consensual and non-consensual intercourse, bolster the survivors' credibility, and increase prosecutions in sexual assault cases.
To identify the constellation of G-A injury-related characteristics that most effectively discriminated between consensual sexual intercourse and sexual assault in females when controlling for intercourse-related variables.
We employed a comparative study with two groups a prospective cohort group with consensual participants and a group derived from an existing sexual assault registry. In the prospective cohort, we performed a sexual assault forensic examination at baseline and following consensual sexual intercourse with females ≥21 years. We compared their injury patterns to the injury records of females ≥21 years who were sexual assaulted.
We enrolled a sample of 834 females 528 consensual (63.3n-consensual intercourse more than two times. Anal tears, swelling, and ecchymosis and anal penetration were markers for non-consensual intercourse and should increase suspicion for lack of consent.
External genital tears occurred more frequently in the non-consensual sample and increased the odds of non-consensual intercourse more than two times. Anal tears, swelling, and ecchymosis and anal penetration were markers for non-consensual intercourse and should increase suspicion for lack of consent.
