Using gas chromatography and mass spectrometry to determine 25-hydroxyvitamin D levels for clinical assessment of vitamin D deficiency

Vitamin D is responsible for multiple metabolic functions in humans. Rickets are the most common disease caused by vitamin D deficiency. It is caused by poor calcium intake resulting in poor serum-ionized calcium. The purpose of this study is to develop a rapid, sensitive, and feasible method to determine the 25-hydroxy-vitamin D3 (25(OH)D3) levels in blood samples for clinical assessment. In this study, gas chromatography coupled mass spectrometry with trimethylsilyl derivatization (TMS-GC-MS) is the most suitable protocol for quantitative analyses of 25(OH)D3. Performance of method was evaluated and compared with liquid chromatography and immunoassay. Method validation has been carried out with plasma specimens. The limit of quantitation of TMS-GC-MS method is 1.5 ppb with good linear correlation. Furthermore, the dietary intake and nutritional status of vegetarian and non-vegetarians in Taiwan were assessed by our validated method. As a result, this vitamin D nutrition survey demonstrates that most Taiwanese people have insufficient vitamin D. Due to dietary habits; the male vegans may have the highest risk of vitamin D deficiency.     

Learning to Discretize: Solving 1D Scalar Conservation Laws via Deep Reinforcement Learning

Conservation laws are considered to be fundamental laws of nature. It has broad applications in many fields, including physics, chemistry, biology, geology, and engineering. Solving the differential equations associated with conservation laws is a major branch in computational mathematics. The recent success of machine learning, especially deep learning in areas such as computer vision and natural language processing, has attracted a lot of attention from the community of computational mathematics and inspired many intriguing works in combining machine learning with traditional methods. In this paper, we are the first to view numerical PDE solvers as an MDP and to use (deep) RL to learn new solvers. As proof of concept, we focus on 1-dimensional scalar conservation laws. We deploy the machinery of deep reinforcement learning to train a policy network that can decide on how the numerical solutions should be approximated in a sequential and spatial-temporal adaptive manner. We will show that the problem of solving conservation laws can be naturally viewed as a sequential decision-making process, and the numerical schemes learned in such a way can easily enforce long-term accuracy. Furthermore, the learned policy network is carefully designed to determine a good local discrete approximation based on the current state of the solution, which essentially makes the proposed method a meta-learning approach. In other words, the proposed method is capable of learning how to discretize for a given situation mimicking human experts. Finally, we will provide details on how the policy network is trained, how well it performs compared with some state-of-the-art numerical solvers such as WENO schemes, and supervised learning based approach L3D and PINN, and how well it generalizes.     

Caffeic acid phenethyl ester,a propolis polyphenolic,attenuates potentially cadmium-induced testicular dysfunction in mice

Abstract

Cadmium (Cd) as environmental pollutant can induce severe damage, particularly to the testis. This study investigated the effects of Caffeic acid phenethyl ester (CAPE) on testicular dysfunction induced by Cd. Adult mice were intraperitoneally injected with cadmium chloride (CdCl₂) with different doses of CAPE pretreatment. After CdCl₂ injection, body/testis weight ratio decreased, Cd levels accumulated and zinc levels decreased in testis. Furthermore, Cd intoxication caused a significant increase of oxidative stress levels, antioxidant enzymes activities, and glutathione levels. Interestingly, significant improvements were observed after the administration of CAPE. Our results demonstrated the protective effect of CAPE, linking Cd testicular dysfunction to oxidative stress.     

手术室新护士三年阶梯式培训模式探讨

目的探讨手术室新护士三年培训模式和方法。方法采用三年阶梯式培养模式,建立完整的系统培训架构,包括培训对象的界定、培训原则及目的、培训目标师资队伍的培养、阶段培养计划、使用培训手册、培训考核体系的建立、培训评价体系的建立等。结果新护士培训系统、科学。结论新护士三年阶梯式培养值得深入研究和推广应用。     

Sex‐related Disparity in Surgical Mortality among Pediatric Patients

Background. It has been reported that gender differences in cardiovascular outcomes found in adults also are present in children who undergo surgical repair for congenital heart disease. Methods. California statewide hospital discharge data 1989–99 were used to study outcomes in children <18 years undergoing cardiac surgery. Hospital discharge data were linked to death registry data to study postdischarge death within 30 days of discharge. We used logistic regression to evaluate the effect of gender on mortality controlling for age, race and ethnicity, type of insurance, household income, date and month of surgery, type of admission, hospital case volume, and various types of procedures. Results. There were 25 402 cardiac surgery cases with 1505 in‐hospital deaths (mortality rate of 5.92%). An additional 37 deaths occurred within 30 days after hospital discharge. Crude mortality rates for males (5.99%) and females (5.84%) were not significantly different. However, fewer neonates were female and females underwent a higher proportion of low‐risk procedures than males. Logistic regression revealed that females, compared with males, had a significantly higher odds ratio (OR) for in‐hospital mortality (OR = 1.18, P < .01) and overall (up to 30 days post discharge) mortality (OR = 1.18, P < .01). The risk‐adjusted length of hospital stay was similar between females and males while charges per hospital day were slightly higher in females than males. The prevalence of Down syndrome, pulmonary hypertension, and failure to thrive were higher in females. Conclusions. Female gender is associated with an 18% higher in‐hospital and 30‐day postdischarge mortality as compared with male gender. There was no difference in length of hospital stay between males and females. The mechanism by which female gender acts as a risk factor requires further investigation.     

大鼠脑血肿周围组织半胱氨酸天冬氨酸蛋白酶3表达变化与尼莫地平的影响

目的：观察脑出血后血肿周围半胱氨酸天冬氨酸蛋白酶3的表达。及尼莫地平对其的影响。方法：实验于2004—07在大连医科大学中心实验室进行。取120只SD雄性大鼠随机分为3组：①尼莫地平组（n=50）：尾壳核注射自体股动脉血50μL复制脑出血模型，造模即刻腹腔注射尼莫地平1．6mg／kg（即8μL／g），以后每天1次。②模型组（n=50）：同前造模，术后腹腔注射等量生理盐水。③假手术组（n=20）：手术，但进针人尾壳核后不注血。各组分为术后6，24，48，72h、5d 5个时间点。造模动物醒后进行Bederson评分，评估其行为和神经功能缺陷（0—3分。评分越高，神经功能缺陷越重，评分≥2分为造模成功）。人组动物在以上5个时间点进行Bederson评分后，麻醉状态下处死取脑，经尾壳核行冠状切片，行免疫组化测定半胱氨酸天冬氨酸蛋白酶3表达。结果：80只大鼠进入结果分析。①Bederson评分：模型组、尼莫地平组大鼠醒后迅速出现偏瘫，24h后评分趋于稳定，至72h之间评分最高，然后逐渐下降，5d时仍有体征。模型组、尼莫地平组各时间点评分均高于对照组（P〈0．01），尼莫地平组术后48，72h评分低于模型组（P〈0.05）。②血肿周围组织半胱氨酸天冬氨酸蛋白酶3表达：假手术组进针侧脑组织表达很少，模型组6h后即有表达，24h达高峰，持续72h后逐渐下降，5d后仅有少量表达；尼莫地平组动态变化趋势与模型组相同，但各时间点的数值均较低，尤其是术后24～72h（P〈0．01）。结论：①脑出血后血肿周围组织中半胱氨酸天冬氨酸蛋白酶3表达升高，提示其与脑出血血肿周围组织损伤有一定关系。②尼莫地平降低脑出血后血肿周围组织中半胱氨酸天冬氨酸蛋白酶3表达，从而减轻细胞凋亡程度，对神经细胞起到保护作用，降低神经功能缺陷。     

铜绿假单胞菌噬菌体PaP3生物学特性的研究

目的测定铜绿假单胞菌噬菌体PaP3的最佳感染复数、一步生长曲线和吸附K值及交叉吸附K值等基本生物学特性。方法按照感染复数（MOI）分别为0．0001、0．001、0．01、0．1、1和10加入噬菌体纯培养液和宿主菌，充分裂解细菌后，测定噬菌体滴度；以MOI=10的比例加入噬菌体及宿主菌，进行一步生长实验；纯化PaP3颗粒，免疫家兔，获得抗血清，通过中和反应实验测定PaP3和其抗血清之间的吸附反应常数K值。同时，利用抗血清交叉中和试验确定本室分离的三株噬菌体之间的血清学关系。结果当MOI=0．001时PaP3感染其宿主菌产生的子代噬菌体滴度最高；根据一步生长实验结果绘制一步生长曲线；通过血清交叉中和反应得出不同的吸附常数。结论PaP3最佳感染复数为0．001，感染宿主菌的潜伏期是20min，爆发期是60min，平均爆发量约为31，其抗血清反应的吸附常数K值为262。