Effect of Cd on Mechanical Properties of Al-Si-Cu-Mg Alloys under Different Multi-Stage Solution Heat Treatment

Multi-stage heat treatment is an important method to improve the mechanical properties of Al-Si-Cu-Mg aluminum alloys. In this paper, the multi-stage heat treatment was carried out for the Cd-free and Cd-containing alloys. The experimental results show that the addition of Cd promoted the precipitation of Q″ and θ″, which led to the formation of a large number of fine, dispersed precipitates and a higher yield strength (YS) and ultimate tensile strength (UTS) for the Cd-containing alloys. The addition of Cd also altered the optimal heat treatment parameters. For the Cd-free alloys, the Cu-rich phase fully dissolved after three-stage heat treatment, and the YS and UTS of the three-stage heat-treated alloys were higher than their two-stage heat-treated counterparts. For the Cd-containing alloys, the three-stage heat treatment led to the precipitation of Cd-rich low melting point phases, caused defects, and reduced the mechanical properties of the alloy. The size and volume fractions of the precipitates were significantly less than those of the alloys after two-stage heat treatment and the strength of the alloys decreased. Therefore, the solution time should be strictly controlled for Cd-containing Al-Si-Cu-Mg alloys.     

Pre-attack and pre-episode symptoms in cluster headache: a multicenter cross-sectional study of 327 Chinese patients

BackgroundThere have been a few studies regarding the pre-attack symptoms (PAS) and pre-episode symptoms (PES) of cluster headache (CH), but none have been conducted in the Chinese population. The purpose of this study was to identify the prevalence and features of PAS and PES in Chinese patients, as well as to investigate their relationships with pertinent factors.MethodsThe study included patients who visited a tertiary headache center and nine other headache clinics between January 2019 and September 2021. A questionnaire was used to collect general data and information about PAS and PES.ResultsAmong the 327 patients who met the CH criteria (International Classification of Headache Disorders, 3rd edition), 269 (82.3%) patients experienced at least one PAS. The most common PAS were head and facial discomfort (74.4%). Multivariable logistic regression analysis depicted that the number of triggers (OR = 1.798, p = 0.001), and smoking history (OR = 2.067, p = 0.026) were correlated with increased odds of PAS. In total, 68 (20.8%) patients had PES. The most common symptoms were head and facial discomfort (23, 33.8%). Multivariable logistic regression analysis showed that the number of triggers were associated with increased odds of PES (OR = 1.372, p = 0.005).ConclusionsPAS are quite common in CH patients, demonstrating that CH attacks are not comprised of a pain phase alone; investigations of PAS and PES could help researchers better understand the pathophysiology of CH.     

糖尿病周围神经病变病因病机及证治方药的研究进展

糖尿病周围神经病变(diabetic peripheral neuropathy,DPN)是糖尿病最常见的三大并发症之一,其发病机制还不明确,起病隐匿,发病率高。DPN主要的临床表现为肢体的疼痛、麻木、感觉异常,甚至肌肉萎缩等,严重影响患者的生活和生命质量。因此,预防和治疗DPN是目前糖尿病治疗的重要课题之一。近年来,中医学对DPN的认识日益深入,取得一定的成绩,本文主要从中医病因病机、证治方药以及实验研究方面来介绍近年来中医药治疗DPN的概况,总结DPN的病机演变、证治规律以及待解决的问题,旨在为今后的糖尿病周围神经病变的中医药研究和治疗提供参考。     

Associations between Abnormal Eating Styles and Irritable Bowel Syndrome: A Cross-Sectional Study among Medical School Students

(1) Background: Few studies have investigated the association between eating styles and IBS. This study aimed to explore the association between abnormal eating styles and irritable bowel syndrome (IBS). (2) Methods: This cross-sectional study investigated students in China Medical University and Shenyang Medical College. Eating styles were evaluated by the Dutch Eating Behavior Questionnaire (DEBQ), and IBS was diagnosed according to Rome III criteria. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). (3) Results: A total of 335 students were diagnosed with IBS. Students with the total scores in tertile 2 and 3 had 1.29 times and 2.75 times higher risk of IBS than students with the total scores in tertile 1, respectively. Simultaneously, the risk of IBS in the tertile 3 of external eating, emotional eating, and restraint eating trends was 3.87 times, 2.71 times, and 3.82 times higher than that of tertile 1, respectively. (4) Conclusions: this study showed that a high score in both total eating styles and each eating style was associated with the odds of having IBS and suggested that the psychological factors behind eating styles may play a critical role in controlling the IBS.     

On the Morphological Deviation in Additive Manufacturing of Porous Ti6Al4V Scaffold: A Design Consideration

Additively manufactured Ti scaffolds have been used for bone replacement and orthopaedic applications. In these applications, both morphological and mechanical properties are important for their in vivo performance. Additively manufactured Ti6Al4V triply periodic minimal surface (TPMS) scaffolds with diamond and gyroid structures are known to have high stiffness and high osseointegration properties, respectively. However, morphological deviations between the as-designed and as-built types of these scaffolds have not been studied before. In this study, the morphological and mechanical properties of diamond and gyroid scaffolds at macro and microscales were examined. The results demonstrated that the mean printed strut thickness was greater than the designed target value. For diamond scaffolds, the deviation increased from 7.5 μm (2.5% excess) for vertical struts to 105.4 μm (35.1% excess) for horizontal struts. For the gyroid design, the corresponding deviations were larger, ranging from 12.6 μm (4.2% excess) to 198.6 μm (66.2% excess). The mean printed pore size was less than the designed target value. For diamonds, the deviation of the mean pore size from the designed value increased from 33.1 μm (−3.0% excess) for vertical struts to 92.8 μm (−8.4% excess) for horizontal struts. The corresponding deviation for gyroids was larger, ranging from 23.8 μm (−3.0% excess) to 168.7 μm (−21.1% excess). Compressive Young’s modulus of the bulk sample, gyroid and diamond scaffolds was calculated to be 35.8 GPa, 6.81 GPa and 7.59 GPa, respectively, via the global compression method. The corresponding yield strength of the samples was measured to be 1012, 108 and 134 MPa. Average microhardness and Young’s modulus from α and β phases of Ti6Al4V from scaffold struts were calculated to be 4.1 GPa and 131 GPa, respectively. The extracted morphology and mechanical properties in this study could help understand the deviation between the as-design and as-built matrices, which could help develop a design compensation strategy before the fabrication of the scaffolds.     

A Warhead Substitution Study on the Coronavirus Main Protease Inhibitor Nirmatrelvir

The SARS-CoV-2 pandemic is currently causing an unprecedented global health emergency since its emergence in December 2019. In December 2021, the FDA granted emergency use authorization to nirmatrelvir, a SARS-CoV-2 main protease inhibitor, for treating infected patients. This peptidomimetic is designed with a nitrile warhead, which forms a covalent bond to the viral protease. Herein, we investigate nirmatrelvir analogs with different warheads and their inhibitory activities. In addition, antiviral activities against human alphacoronavirus 229E was also investigated along with a cell-based assay. We discovered that the hydroxymethylketone and ketobenzothiazole warheads were equipotent to the nitrile warhead, suggesting that these analogs can also be used for treating coronavirus infections.     

Binswanger病血液流变学及血液成份的观察

本文测定了３５例老年Ｂｉｎｓｗａｎｇｅｒ病患者的部分血液流变学及血液成份的变化。结果发现，与健康对照组和脑动脉硬化组比较，疾病组高切变率全血粘度显著升高，红细胞变形能力明显降低，血液成份ＨＧ、ＭＣＶ、ＭＣＨ、ＭＣＨＣ、ＲＤＷ显著增加。提示红细胞的老化性改变参与了Ｂｉｎｓｗａｎｇｅｒ病的发生，设法提高患者红细胞变形能力和降低血粘度将有益于阻止该病的进展。     

输尿管镜下尿道会师术治疗尿道骑跨伤体会

目的 探讨输尿管镜下尿道会师术治疗尿道骑跨伤的临床价值.方法 对17例尿道骑跨伤患者采用输尿管镜引导放置导尿管,随访观察手术的效果.结果 17例中,3例因尿道完全断裂,镜下会师失败后,2例改行开放会师术,1例行耻骨上膀胱穿刺造瘘术;其余14例采用输尿管镜下尿道会师术均1次成功.术后均获随访 0.5~1年,除2例排尿明显变细、需定期尿道扩张外,其余患者未出现尿道狭窄、尿失禁、性功能障碍等并发症.结论 输尿管镜下尿道会师术手术时间短、创伤小、恢复快、效果好,是治疗尿道骑跨伤的有效方法.     

iTRAQ串联质谱筛选尾吊小鼠感染空间诱变大肠杆菌后脾脏差异表达蛋白

目的应用同重同位素标记相对与绝对定量技术(iTRAQ),联合液相色谱串联质谱(LC-MS/MS),检测经空间诱变大肠杆菌(T1-13)感染尾吊模拟失重小鼠后,其脾脏组织中的差异蛋白,并探讨其生物学意义。方法 C57BL/6小鼠尾吊模拟失重后以空间诱变大肠杆菌灌胃建立感染模型,采用iTRAQ结合LC-MS/MS技术筛选脾脏组织差异表达蛋白,并对差异蛋白进行GO、pathway富集分析和STRING蛋白互作分析。结果共鉴定出2589个蛋白,尾吊组与对照组相比筛选出378个差异表达蛋白。尾吊染菌后与对照组相比,共筛选出452个差异表达蛋白,STRING蛋白互作网络中有286个差异蛋白间存在相互作用,这些差异蛋白经KEGG分析共得到32条存在显著性的通路,主要为氧化磷酸化通路,代谢通路、蛋白消化和吸收通路、蛋白酶体通路。结论成功筛选出了模拟失重后空间诱变大肠杆菌感染脾脏组织差异表达蛋白,这些差异蛋白可能通过调控代谢通路、不同环境下微生物代谢、颉氨酸/亮氨酸/异亮氨酸降解、溶酶体、碳代谢、吞噬体、丙酸代谢、蛋白酶体参与失重条件下免疫和炎症反应的发生。     

原发性肝癌全肝切除标本的病理解剖学特征及其启示

目的 探讨原发性肝癌的病理解剖学特征及其意义.方法 2000年8月至2007年12月共有89例肝硬化合并原发性肝癌患者接受肝移植手术,收集手术切除标本及受侵犯的邻近组织和肿大的淋巴结.将标本沿冠状切面每隔1.0 cm切开,观察肝癌的大小、数目、分布、包膜、门静脉瘤栓、卫星灶,并记录卫星灶与主瘤问的距离、受肝癌侵犯的组织、淋巴结等,然后送病理学检查,最终诊断以病理报告为准.结果 89例患者中,肝细胞肝癌86例,胆管细胞性肝癌3例;多发肿瘤53例,单发肿瘤36例;13例主瘤在右叶,但左叶存在小癌灶;14例有较完整的包膜,75例无包膜,无包膜病例中11例边界不清;术中所见侵犯邻近组织的25例患者中,8例经病理证实,16例的肿大淋巴结中7例有癌浸润;有门静脉主干或分支瘤栓者42例(47.2%),有卫星灶者39例(43.8%),瘤栓与卫星灶随肿瘤体积、数目增加而增加;卫星灶距主瘤距离多为0.5～3.0 cm,少数达5.0 cm.结论 全肝切除标本能全面地反映肝癌牛长和浸润特征.应警惕门静脉瘤栓及卫星灶的存在,特别是距主瘤较远的卫星灶及门静脉小支内的瘤栓,以及分布在另一肝叶的小癌灶.这些因素在影像学检查时容易漏诊,但会影响肝切除术或肝移植术的疗效.