Experiment and Theoretical Investigation on Fatigue Life Prediction of Fracturing Pumpheads Based on a Novel Stress-Field Intensity Approach

Fracturing pumpheads are typical pressure vessels that experience frequent fatigue failure under the effect of notches in their cross-bore. To enhance the fatigue life of fracturing pumpheads, the study of the notch effect is indispensable and important to establish a reliable mathematical model to predict their fatigue life. In the present paper, two novel fatigue life prediction models are proposed for notched specimens. In these models, two new geometric fatigue failure regions are defined to improve the weight function. Finally, the elaborated novel stress-field intensity approach was applied to three different types of notched specimens. Experiment results indicate that the new SFI approach achieves 47.82%, 39.48%, and 31.85% higher prediction accuracy than the traditional SFI approach, respectively. It was found that the modified SFI approach provided better predictions than the traditional SFI approach and the TCD method. The II-th novel SFI approach had the highest accuracy, and the I-th novel SFI approach was more suitable for sharply notched specimens.     

Assessing the Association between Important Dietary Habits and Osteoporosis: A Genetic Correlation and Two-Sample Mendelian Randomization Study

Objective: Osteoporosis (OP) is the most common bone disease. The genetic and metabolic factors play important roles in OP development. However, the genetic basis of OP is still elusive. The study aimed to explore the relationships between OP and dietary habits. Methods: This study used large-scale genome-wide association study (GWAS) summary statistics from the UK Biobank to explore potential associations between OP and 143 dietary habits. The GWAS summary data of OP included 9434 self-reported OP cases and 444,941 controls, and the GWAS summary data of the dietary habits included 455,146 participants of European ancestry. Linkage disequilibrium score regression (LDSC) was used to detect the genetic correlations between OP and each of the 143 dietary habits, followed by Mendelian randomization (MR) analysis to further assess the causal relationship between OP and candidate dietary habits identified by LDSC. Results: The LDSC analysis identified seven candidate dietary habits that showed genetic associations with OP including cereal type such as biscuit cereal (coefficient = −0.1693, p value = 0.0183), servings of raw vegetables per day (coefficient = 0.0837, p value = 0.0379), and spirits measured per month (coefficient = 0.115, p value = 0.0353). MR analysis found that OP and PC17 (butter) (odds ratio [OR] = 0.974, 95% confidence interval [CI] = (0.973, 0.976), p value = 0.000970), PC35 (decaffeinated coffee) (OR = 0.985, 95% CI = (0.983, 0.987), p value = 0.00126), PC36 (overall processed meat intake) (OR = 1.035, 95% CI = (1.033, 1.037), p value = 0.000976), PC39 (spirits measured per month) (OR = 1.014, 95% CI = (1.011, 1.015), p value = 0.00153), and servings of raw vegetables per day (OR = 0.978, 95% CI = (0.977, 0.979), p value = 0.000563) were clearly causal. Conclusions: Our findings provide new clues for understanding the genetic mechanisms of OP, which focus on the possible role of dietary habits in OP pathogenesis.     

胎儿端脑突触素表达和突触发育的研究

为了探讨突触素(SYN)在不同周龄阶段胎儿端脑额叶中的表达与胎儿额叶皮质突触发育的关系,本研究采用免疫组织化学方法观察突触素在不同周龄阶段胎儿额叶的表达水平,利用计算机图像分析技术测量不同周龄阶段胎儿额叶突触素表达的平均光密度;同时取材、常规电镜技术处理、透射电镜观察额叶突触发育的超微结构变化。结果显示:(1)光镜下各组均可见SYN免疫阳性产物主要表达于胎儿的额叶皮层,其表达量随周龄的增加而增强,各组间呈现显著性差异(P<0.05),其中16～24周胎儿额叶的阳性产物位于神经元的胞浆内,呈均匀的浅黄色,神经元突起内未见阳性产物;25～29周额叶的阳性产物呈黄色,在胞浆和突起内均可见,但阳性产物的量却下降;而30～39周额叶的SYN阳性产物呈棕黄色的点状或颗粒状,主要位于神经元的突起内,神经元胞浆内未见阳性产物,阳性产物的量显著增加;(2)透射电镜下19～36周胎儿大脑额叶均可见到突触样结构,随着周龄的增加,突触的数量逐渐增多,结构逐渐清晰和完整。上述结果提示SYN的表达可以反映胎儿神经系统发育的程度,SYN的表达与突触的发育是一致的;SYN在胎儿大脑额叶的表达部位经历由神经元胞浆内表达为主到神经元终末表达为主的这一过程,可能是由于SYN先是在神经元胞浆内合成,再随着神经元的发育而逐步转移到神经元突起的末梢部位。     

Intraoperative malignant glaucoma during femtosecond laser-assisted cataract surgery: A case report

Rationale:Femtosecond laser-assisted cataract surgery (FLACS) has grown in popularity among ophthalmologists as a novel surgical technique. However, malignant glaucoma (MG) is a complication of FLACS. Herein, we report a case of MG following FLACS.Patient concerns:A 66-year-old woman presented with complaints of blurred vision in the right eye and a foreign body sensation in both eyes. Ophthalmological examinations showed that the corrected distance visual acuity was 20/50 and 20/25 in the right and left eyes, respectively. Without any topical anti-glaucoma medication, the intraocular pressure (IOP) was 20 mmHg in the right eye and 17 mmHg in the left eye. Slit-lamp examination of the right eye revealed a transparent cornea with a defect in the punctate overlying epithelium; the central anterior chamber depth was shallow the peripheral iris laser shot was visible, the pupil was normal, and the lens was mainly cortical opacified.Diagnoses:Based on the patient''s symptoms, examination results, and preliminary diagnoses, age-related cataract in the right eye, binocular post-antiglaucoma surgery, pseudophakicin in the left eye, and Sjogren syndrome were included.Interventions:FLACS was performed to facilitate anterior capsulotomy and segmentation of the nucleus in the right eye. MG occurred after the femtosecond procedure, and with the treatment of medicines combined with phacoemulsification, IOP was eventually normal without further antiglaucoma therapy.Outcomes:IOP was 16 mmHg on postoperative day 1. Ocular ultrasonography revealed no choroid detachment or hemorrhage in the right eye. Two weeks postoperatively, uncorrected visual acuity was 20/25, and IOP remained normal with no further antiglaucoma treatment on 1 month postoperatively.Conclusions:We describe the occurrence of MG after FLACS and illustrate that miosis and bubble formation after FLACS may be risk factors for MG during FLACS.     

Development and Primary Application of an Indirect ELISA Based on Rep Protein to Analyze Antibodies against Porcine Cocirvirus-like Virus (PCLV)

Porcine circovirus-like virus (PCLV) is a member of circovirus that contains a single-strand DNA genome, which may be one of the pathogens that causes diarrheal symptoms in pigs. The Rep protein encoded by the genome of PCLV may be responsible for viral genome replication. The development of serological detection methods for PCLV is of great necessity for clinical diagnosis, as well as epidemiological investigations. Therefore, this study attempted to build an indirect enzyme-linked immunosorbent assay (ELISA) to examine antibodies against PCLV based on the His-tagged recombinant Rep protein. Full-length PCLV Rep protein was induced and expressed in E. coli and was purified as an antigen to establish an ELISA detection kit. The purified Rep protein was used to inject into mice to produce specific antibodies. There was no cross-reaction of Rep-based ELISA with antisera against other porcine viruses. The intra-assay and inter-assay coefficient variations (CVs) were 0.644–8.211% and 0.859–7.246%, respectively, indicating good repeatability. The non-cross-reaction with TGEV, PRRSV and PCV2 testing showed high sensitivity and high specificity for this ELISA assay. A total of 1593 serum samples collected from different pig farms in Jiangxi Province were tested for anti-PCLV Rep antibodies, and 284 (17.83%) of the 1593 samples were Rep antibody positive. Altogether, the indirect ELISA detection tool developed in this study could be applied to examine serum of PCLV antibodies with good repeatability, high sensitivity and high specificity. In addition, field sample detection results suggested that the PCLV antibody has a low prevalence in pig populations in Jiangxi Province of China.     

实验室信息管理系统的技术与应用进展

实验室信息管理系统(LIMS)自问世以来,在世界范围内取得了令人惊叹的技术进展和应用成就。该文从现代化实验室实施LIMS的意义,LIMS主要的技术发展阶段,目前国内LIMS的应用情况,分析测试性实验室在实施LIMS后预期达到的目标,以及当前LIMS项目实施中存在的问题和应用前景等方面进行综述。     

甲硝唑、维生素B2、珍珠粉等配伍治疗口腔溃疡临床研究

目的:探讨甲硝唑、维生素B2、珍珠粉等配伍治疗口腔溃疡的疗效.方法:选取200例于2014年6月1日~2016年6月1日我院接收的复发性口腔溃疡患者,随机分为对照组(给予西瓜霜喷剂治疗,n=100)与观察组(采用甲硝唑、维生素B2、珍珠粉等配伍治疗,n=100),观察两组疗效.结果:治疗7d后,观察组临床总有效率较对照组显著要高(P<0.05),复发率显著低于对照组(P<0.05);观察组疼痛感消除时间、溃疡治愈时间均较对照组显著要短(P<0.05);治疗后,两组外周血CD4+、CD4+/CD8+水平明显升高,观察组升高幅度较对照组显著(P<0.05).结论:复发性口腔溃疡采取甲硝唑、维生素B2、珍珠粉、山茶油配伍治疗,疗效显著,具有推广价值.     

Constructing Heterogeneous Photocatalysts Based on Carbon Nitride Nanosheets and Graphene Quantum Dots for Highly Efficient Photocatalytic Hydrogen Generation

Although graphitic carbon nitride nanosheets (CNs) with atomic thickness are considered as promising materials for hydrogen production, the wide band gap (3.06 eV) and rapid recombination of the photogenerated electron–hole pairs impede their applications. To address the above challenges, we synergized atomically thin CNs and graphene quantum dots (GQDs), which were fabricated as 2D/0D Van der Waals heterojunctions, for H₂ generation in this study. The experimental characterizations indicated that the addition of GQDs to the π-conjugated system of CNs can expand the visible light absorption band. Additionally, the surface photovoltage spectroscopy (SPV) confirmed that introducing GQDs into CNs can facilitate the transport of photoinduced carriers in the melon chain, thus suppressing the recombination of charge carriers in body. As a result, the H₂ production activity of the Van der Waals heterojunctions was 9.62 times higher than CNs. This study provides an effective strategy for designing metal-free Van der Waals hetero-structured photocatalysts with high photocatalytic activity.     

膨体聚四氟乙烯填塞结合隆鼻手术治疗严重萎缩性鼻炎的临床观察#br#

目的　膨体聚四氟乙烯（expanded Polytetrafluoroethylene,e-PTFE）（简称膨体）填塞结合隆鼻手术综合治疗鼻中线低平的严重萎缩性鼻炎,提高疗效并改善患者生理及心理疾患。方法　收集联勤保障部队第九○八医院耳鼻咽喉头颈外科2010年1月至2021年1月期间确诊为萎缩性鼻炎患者50例,A组25例患者全部采用羟基磷灰石填塞法治疗,B组25例患者全部采用膨体填塞结合隆鼻手术综合治疗。采用鼻小柱切口,翻盖式手术切口暴露鼻中隔及鼻底部,在鼻腔内、下壁黏膜下填塞膨体及抬高鼻尖缩窄前鼻孔等综合治疗方法。结果　术后3个月、3~6个月除感染、外露手术失败者,A、B两组患者术后效果无统计学意义（P >0.05）,术后6~12个月后随诊B组满意率显著高于A组,鼻腔通气稳定,差异有统计学意义（P<0.05）。结论　膨体填塞结合隆鼻手术综合治疗鼻中线低平的严重萎缩性鼻炎,较唇龈切口黏骨膜下填入羟基磷灰石,长期效果稳定,患者满意度高,使用范围及前景更大,值得临床推广。