Structural and physiological changes of the human body upon SARS-CoV-2 infection

Since December 2019, the novel coronavirus(severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)) has spread to many countries around the world, developing into a global pandemic with increasing numbers of deaths reported worldwide. To data, although some vaccines have been developed, there are no ideal drugs to treat novel coronavirus pneumonia(coronavirus disease 2019(COVID-19)). By examining the structure of the coronavirus and briefly describing its possible pathogenesis based on recent autopsy reports conducted by various teams worldwide, this review analyzes the possible structural and functional changes of the human body upon infection with SARS-CoV-2. We observed that the most prominent pathological changes in COVID-19 patients are diffuse alveolar damage(DAD) of the lungs and microthrombus formation,resulting in an imbalance of the ventilation/perfusion ratio and respiratory failure. Although direct evidence of viral infection can also be found in other organs and tissues, the viral load is relatively small. The conclusion that the injuries of the extrapulmonary organs are directly caused by the virus needs further investigation.     

Lipid peroxides,vitamin E levels and glutathione peroxidase activity in serum of respiratory disease patients

The concentration of serum lipid peroxides, tocopherol and glutathione peroxidase (GPx) activity was measured in 75 patients (43 males and 32 females) of different respiratory diseases aged 15–40 years. The results were compared with the values obtained from 100 healthy persons of comparabie age. The patients of respiratory diseases showed elevated levels of lipid peroxides with concomitant reduction of tocopherol and glutathione peroxidase activity. When these patients were categorised into different groups depending on the type of the disease like pulmonary tuberculosis (PT), chronic obstructive pulmonary disease (COPD), pulmonary tuberculosis and chronic obstructive pulmonary disease (PT and COPD) and suppurative lung disease (SLD). There was no significant difference between the groups. A significant inverse relation was found between lipid peroxides versus tocopherol and glutathione peroxidase activity in patients of respiratory diseases. The results suggest the involvement of lipid peroxidation process in pulmonary damage.     

反应液滴加次序对液相还原法制备纳米Co-Cu-B合金的影响研究

采用液相还原法,以KBH4作还原剂,PVP为分散剂,在二价钴、铜盐的纯水溶液中采用两种不同的反应液滴加顺序制备出纳米Co-Cu-B系合金粉体材料。运用XRD、EDS、AES、SEM和VSM等分析方法对制备的产物进行物相、成分、结构形貌、磁学性能的检测分析。检测分析结果表明:反滴工艺不易保证还原反应的充分进行,并且产物中存在氧化物夹杂,影响产物的磁学性能。因此,为了获得具有良好性能的合金粉末,反应物合适的滴加顺序应该是:将还原剂溶液缓慢地滴加至金属盐溶液中。     

ICU气管切开患者下呼吸道感染的护理干预

目的探讨护理干预对ICU气管切开患者下呼吸道感染发生率的影响。方法将我院ICU收治的100例气管切开患者随机分为观察组和对照组各50例,观察组患者采取相应的护理干预措施,对照组患者采取常规护理措施,比较两组患者下呼吸道感染的发生率。结果观察组发生下呼吸道感染6例,对照组发生下呼吸道感染23例,两组患者比较差异显著（P〈0.01）,具有统计学意义。结论采取护理干预措施能有效降低气管切开患者下呼吸道感染的发生率,对改善患者预后具有重要意义。     

严重急性呼吸系统综合征的影像学表现及临床特点

目的 :探讨急性呼吸系统综合征的胸部影像学表现及临床特点。方法 :对经确诊的 30例严重急性呼吸综合征患者的胸部影像学表现和临床特点进行回顾性分析。结果 :此 30例SARS患者的胸部影像学表现由肺实质的渗出或 /和间质的渗出程度所决定 ,根据病变早期及进展期的表现分为 4型 :(1 )局限小片型 :8例 ,早期为一片状局限灶性实变 ,随后病灶可增大 ,然后渐次吸收。(2 )广泛大片型 :6例 ,由早期单一局限片状病灶迅速发展为广泛大片状影(范围≥ 2个肺野 )。(3)间质肺纹型 :1 0例 ,主要表现为肺间质渗出性炎症 ,可有“粗网”、“细网”、“网点”之分。(4)多发混合型 :6例 ,早期即见肺内多发(病灶数目≥ 2个 )片状及结节状病灶或 /和与其它肺野的“网格状”及“网 -点状”阴影共在。结论 :X线检查是发现SARS的最基本的影像学检查方法。CT能更好地显示病变。在SARS的诊治过程中 ,影像学的“三有”与“三无”和实验室检查的“三高”与“三低”对诊断分型、分期有益 ,并有助于判断病情 ,指导治疗 ,估计预后     

反复呼吸道感染幼儿血铅水平及其对免疫系统的影响

目的：探讨幼儿反复呼吸道感染（RRTI）血铅水平分布与免疫系统机能变化的关系。方法：自2005．6～12月，从我院收治的RRTI幼儿中随机筛选80例病例，在RRTI发作期，用原子吸收分光光度法进行血铅测定，依照1991年美国疾病控制与预防中心（USCDC）制定的儿童铅中毒诊断分级标准。将受试病例分为6级；用流式细胞仪检测患儿T淋巴细胞亚群，B淋巴细胞亚群，NK细胞；用免疫比浊法测定免疫球蛋白IgA、IgG、IgM水平。对6组患儿进行常规加驱铅治疗，驱铅治疗满一个疗程，分别测定血铅水平，检测IgA、IgG、IgM，T淋巴细胞亚群、B淋巴细胞亚群，NK细胞。结果：（1）80例受试病例治疗前血铅水平均在I～Ⅲ级之间，治疗后血铅水平均在I～Ⅱ级之间，病例分布随着血铅水平增高逐渐减少。（2）治疗前受试病例IgA、IgG、IgM，T淋巴细胞亚群、B淋巴细胞亚群、NK细胞样本均数分别进行F检验，其中IgA、IgG、T淋巴细胞亚群、B淋巴细胞亚群四项免疫指标P〈0．05．存在差异，而IgM、NK细胞P〉0．05。不存在差异。（3）治疗前、后，血铅水平分别与对应的免疫指标IgA、IgG、T淋巴细胞亚群、B淋巴细胞亚群进行相关分析，相关系数进行t检验，显示二者之间存在较明显的负相关（P〈0．05）。结论：（1）80例受试病例均处于铅暴露中，发作期血铅水平病例以I级居多。占63％，Ⅳ～Ⅵ级未见．近似于正偏态分布；治疗后，I级占96．25％，Ⅲ～Ⅵ级未见。（2）治疗前，患儿血铅水平增高，IgA、IgG、T淋巴细胞亚群、B淋巴细胞亚群含量趋于降低，治疗后，血铅水平降低。以上四项免疫指标升高。说明幼儿患反复呼吸道感染与铅暴露及其所致的免疫机能抑制有关。     

浅谈运动、免疫与感染

近年来,有相当部分的教练员、队医、运动员感觉到大运动量训练和比赛后上呼吸道感染的发病率显著增加.因此,研究运动与上呼吸道感染之间的关系对运动员坚持大运动量训练和比赛中获取优异成绩有积极的作用.本文通过查阅大量资料,综述了上呼吸道感染的发生与运动、免疫之间的关系,对其发病机理进行了分析,并提出了可行的预防措施.     

Indirect measures of substrate utilisation following exercise-induced muscle damage

Abstract

This study investigated whether exercise-induced muscle damage (EIMD) resulted in changes to whole-body substrate utilisation during exercise performed during the subsequent 48 hours. Eight males (31±6 years) performed 30 minutes of bench-stepping exercise. One leg performed eccentric contractions (Ecc) by lowering the body whilst the control leg performed concentric contractions (Con) by raising the body. On the two days following bench-stepping exercise participants performed measures of muscle function on an isokinetic dynamometer and undertook a bout of one leg cycling exercise, at two differing workloads, with the first workload (WL1) at 1.5±0.25 W/kg and the second workload (WL2) at 1.8±0.25 W/kg with each leg. Expired respiratory gases were collected during cycling to estimate whole body substrate utilisation. There were significant decrements in measures of muscular performance (isometric force, concentric and eccentric torque) and increased perception of soreness in Ecc compared with Con (P < 0.05). The effect of the Ecc treatment on substrate utilisation during one-legged cycling revealed a significant trial×time interaction with higher rates of CHO oxidation in the Ecc condition compared with Con that were further increased 48 hours later (P = 0.02). A significant treatment×time×effort interaction (P < 0.01) indicated the effect of the treatment altered as workload increased with higher rates of CHO oxidation occurring in WL2. This is consistent with greater reliance upon muscle glycogen. Suggesting that in EIMD, reductions in strength and increased feelings of soreness can be associated with greater reliance upon intramuscular CHO oxidation, than lipid, during subsequent concentric work.     

混合时间窗下多目标电商物流路径优化研究

结合电商物流特点,探讨混合时间窗车辆路径问题,设计了混合时间窗惩罚函数和模糊预约时间函数,建立了基于混合时间窗约束的多目标车辆路径模型。设计了改进智能水滴算法对模型进行求解,改进节点概率选择方式来保护优秀水滴,设置路径泥土量最大和最小限制以防止算法提前进入收敛。最后,运用实际案例模拟计算,与传统智能水滴算法计算结果对比分析。结果表明,改进智能水滴算法求解混合时间窗下多目标电商物流路径优化问题,能够以很高的概率获得更优的全局最优解,是求解这类问题有效算法。     

Impact of COVID-19 pandemic on the pregnancy outcomes of women undergoing assisted reproductive techniques (ARTs): a systematic review and meta-analysis

The global outbreak of the coronavirus disease 2019 (COVID-19) led to the suspension of most treatments with assisted reproductive technique (ART). However, with the recent successful control of the pandemic in China, there is an urgent public need to resume full reproductive care. To determine whether the COVID-19 pandemic had any adverse effects on female fertility and the pregnancy outcomes of women undergoing ART, a systematic review and meta-analysis was conducted using the electronic Chinese and English databases. Dichotomous outcomes were summarized as prevalence, and odds ratios (ORs) and continuous outcomes as standardized mean difference (SMD) with 95% confidence interval (CI). The risk of bias and subgroup analyses were assessed using Stata/SE 15.1 and R 4.1.2. The results showed that compared with women treated by ART in the pre-COVID-19 time frame, women undergoing ART after the COVID-19 pandemic exhibited no significant difference in the clinical pregnancy rate (OR 1.07, 95% CI 0.97 to 1.19; I ²=0.0%), miscarriage rate (OR 0.95, 95% CI 0.79 to 1.14; I ²=38.4%), embryo cryopreservation rate (OR 2.90, 95% CI 0.17 to 48.13; I ²=85.4%), and oocyte cryopreservation rate (OR 0.30, 95% CI 0.03 to 3.65; I ²=81.6%). This review provided additional evidence for gynecologists to guide the management of women undergoing ART treatment during the COVID-19 pandemic timeframe.