Analysis on cushion performance of quartz sand in high-g shock

Abstract The cushion protection for light mass electronic instruments in projectile is of vital importance to the normal work of an ammunition system. Quasi-static compression tests were conducted on two kinds of quartz sand with different grain diameters and their energy absorption abilities were analyzed. The cushion effect under high g shock was studied by using air gun. The results of experiments show that the quartz sand material takes in energy by grain breakage and the energy absorption ability in unit volume, the energy absorption ability in unit mass and the ideal energy absorption efficiency all improve with the increase of grain diameter. The cushion efficiency of the coarse quartz sand material with grain diameter of 1.0mm to 5.0mm can reach more than 50% under high g shock. This provides a favorable cushion protection for light mass equipment

Thrombocytopenia Is Associated with Acute Respiratory Distress Syndrome Mortality: An International Study

Background: Early detection of the Acute Respiratory Distress Syndrome (ARDS) has the potential to improvethe prognosis of critically ill patients admitted to the intensive care unit (ICU). However, no reliable biomarkers are currently available for accurate early detection of ARDS in patients with predisposing conditions. Objectives: This study examined risk factors and biomarkers for ARDS development and mortality in two prospective cohort studies. Methods: We examined clinical risk factors for ARDS in a cohort of 178 patients in Beijing, China who were admitted to the ICU and were at high risk for ARDS. Identified biomarkers were then replicated in a second cohort of1,878 patients in Boston, USA. Results: Of 178 patients recruited from participating hospitals in Beijing, 75 developed ARDS. After multivariate adjustment, sepsis (odds ratio [OR]:5.58, 95% CI: 1.70–18.3), pulmonary injury (OR: 3.22; 95% CI: 1.60–6.47), and thrombocytopenia, defined as platelet count <80×103/µL, (OR: 2.67; 95% CI: 1.27–5.62)were significantly associated with increased risk of developing ARDS. Thrombocytopenia was also associated with increased mortality in patients who developed ARDS (adjusted hazard ratio [AHR]: 1.38, 95% CI: 1.07–1.57) but not in those who did not develop ARDS(AHR: 1.25, 95% CI: 0.96–1.62). The presence of both thrombocytopenia and ARDS substantially increased 60-daymortality. Sensitivity analyses showed that a platelet count of <100×103/µLin combination with ARDS provide the highest prognostic value for mortality. These associations were replicated in the cohort of US patients. Conclusions: This study of ICU patients in both China and US showed that thrombocytopenia is associated with an increased risk of ARDS and platelet count in combination with ARDS had a high predictive value for patient mortality

Survival curves of the effects of thrombocytopenia and acute respiratory distress syndrome (ARDS) on 60-day mortality.

<p>Univariate survival analyses show Kaplan-Meier curves of thrombocytopenia (platelet count <80×10³/µL) and ARDS development on 60-day mortality among critically ill patients at-risk for ARDS in the Beijing cohort (upper panel, <i>p</i> = 0.05) and the Boston cohort (lower panel, <i>p</i><0.0001). Blue: non-thrombocytopenia & non-ARDS; red: thrombocytopenia & non-ARDS; green: non-thrombocytopenia & ARDS; orange: thrombocytopenia & ARDS.</p

Sensitivity analysis of combined effects of thrombocytopenia and ARDS^†.

<p>ARDS = acute respiratory distress syndrome; AHR = adjusted hazard ratio.</p><p>*Each line represents a multivariate cox regression with adjustment of age, gender, APACHII score, and sepsis; Platelet count (×10³/µL) was dichotomized by cutoff point;</p>†<p>AHR was estimated by comparison with non-thrombocytopenia/non-ARDS group.</p

Multivariable analysis of mortality predictors in Beijing and Boston cohorts.

<p>ARDS = acute respiratory distress syndrome; APACHE = Acute Physiology and Chronic Health Evaluation; AHR = adjusted hazard ratio; CI = confidence intervals; NS = not selected in multivariate modeling.</p

Adjusted hazard ratios of thrombocytopenia and acute respiratory distress syndrome (ARDS) on 60-day mortality.

<p>Multivariate analyses show adjusted hazard ratios (95% confidence intervals) of thrombocytopenia(platelet count <80×10³/µL) and ARDS development on 60-day mortality among critically ill patients at-risk for ARDS in the Beijing cohort (red) and the Boston cohort (blue), adjusted by APACHE II.</p

Risk factors for 60-day mortality.

<p>ARDS = acute respiratory distress syndrome; APACHE = Acute Physiology and Chronic Health Evaluation; ICU = intensive care unit.</p><p>*APACHE II score was calculated with all components within 24 hours of ICU admission;</p>†<p>Pneumonia, aspiration, pulmonary contusions, or sepsis from lower pulmonary source were categorized as direct pulmonary injury; sepsis from an extrapulmonary source, trauma without pulmonary contusions, and multiple transfusions were categorized as external pulmonary lung injury. Patients with both direct and external pulmonary injuries were considered to have direct lung injury.</p

Baseline characteristics of the Beijing cohort.

<p>ARDS = acute respiratory distress syndrome; APACHE = Acute Physiology and Chronic Health Evaluation; ICU = intensive care unit; IQR = interquartile range.</p><p>*APACHE II score was calculated with all components within 24 hours of ICU admission.</p>†<p>Pneumonia, aspiration, pulmonary contusions, or sepsis from lower pulmonary source were categorized as direct pulmonary injury; sepsis from an extrapulmonary source, trauma without pulmonary contusions, and multiple transfusions were categorized as external pulmonary lung injury. Patients with both direct and external pulmonary injuries were considered to have direct lung injury.</p

sj-docx-1-cll-10.1177_09636897221139734 – Supplemental material for Therapeutic Efficacy of Human Mesenchymal Stem Cells With Different Delivery Route and Dosages in Rat Models of Spinal Cord Injury

Supplemental material, sj-docx-1-cll-10.1177_09636897221139734 for Therapeutic Efficacy of Human Mesenchymal Stem Cells With Different Delivery Route and Dosages in Rat Models of Spinal Cord Injury by Guangyang Liu, Zhiling Zhao, Herui Wang, Chunhua Hao, Weiting Wang, Chenliang Zhang, Tiehua Wang, Xin Li, Jingjing Xi, Shaoyun Li, Haomiao Long, Yi Mi, Li Miao, Yaoyao Chen, Liqiang Xu, Libo Zheng, Hao Wang, Ning Ding, Fengmei Zhu, Qinggang Ge and Yongjun Liu in Cell Transplantation</p