Endothelium-independent relaxation and contraction of rat aorta induced by ethyl acetate extract from leaves of Morus alba (L.)

Aim of the study

Based on screening for vasoactive traditional Chinese medicinal herbs, the present study was performed to investigate the vasoactive effects of an ethyl acetate extract from leaves of Morus alba (L.) (ELM) on rat thoracic aorta and the mechanisms underlying these effects.

Materials and methods

Isolated rat thoracic rings were mounted in an organ bath system and the effects of ELM on their responses were evaluated.

Results

ELM (0.125–32.000 g/l) induced a concentration-dependent relaxation (P < 0.01 vs. control) both in endothelium-intact and -denuded aortas precontracted by high K⁺ (6 × 10⁻² M) or 10⁻⁶ M phenylephrine (PE). In endothelium-denuded aortas, ELM at the EC₅₀ concentration reduced Ca²⁺-induced contraction (P < 0.01 vs. control) after PE or KCl had generated a stable contraction in Ca²⁺-free solution. And after incubation with verapamil, ELM induced contraction in endothelium-denuded aortas precontracted by PE (P < 0.01 vs. control); this was abolished by ruthenium red (P < 0.01 vs. ELM-treated endothelium-denuded group; P > 0.05 vs. control), but not by heparin (P > 0.01 vs. ELM-treated endothelium-denuded group; P < 0.01 vs. control).

Conclusions

The results showed that ELM had dual vasoactive effects, and the relaxation was greater than the contraction. The relaxation was mediated by inhibition of voltage- and receptor-dependent Ca²⁺ channels in vascular smooth muscle cells, while the contraction occurred via activation of ryanodine receptors in the sarcoplasmic reticulum.     

含氢硅油表面接枝改性PET织物的拒水性能

通过接枝率、接触角、透水时间、拉伸应力应变、ＥＳＣＡ的测定以及不冲击实验研究了在ＤＣＰ和ＢＰ等存在下电晕放电引发含氢硅油接枝ＰＥＴ织物及其拒水性能,实验结果表明：电晕放电能有效引发含氢硅油在ＰＥＴ织物表面的接枝共聚反应,随电晕放电处理时间的延长,ＰＥＴ织物表面接枝率增大;接枝后ＰＥＴ织物拒水效果明显增强;电晕放电引发接枝改性后ＰＥＴ织物无损伤,力学性能基本保持不变。     

关于首次病程记录内容和格式的探讨

2002年4月卫生部颂发了<病历书写基本规范(试行)>(以下简称(<部规范>),并要求各地于同年9月1日起执行.因为<部规范>是一个纲领性文件,很多具体的书写格式和要求的细节均未能充分表述,如对首次病程记录书写内容的要求只是一句"首次病程记录的内容包括病例特点、诊断依据及鉴别诊断、诊疗计划等"[1].为便于临床参照执行以及加强病案质量管理,湖南省卫生厅2004年7月出版了<病历书写规范与管理规定及病例(案)医疗质量评定标准>(以下简称<省规范>).为便于临床质量控制,<省规范>在首次病程记录中增加了一项病例分型(病例分型标准:A型:一般病例:B型:一般急症病例;C型:疑难重症病例;D型:危重病例)[2].并对首次病程记录内容的表述略作改动:"首次病程记录的内容包括病例特点、诊断依据及鉴别诊断、病例分型及诊疗计划等"[3].并有如下"示例":     

临床拟诊机化性肺炎31例诊疗的回顾性分析

目的 探讨临床拟诊机化性肺炎的诊断与治疗.方法 回顾性分析31例临床拟诊为机化性肺炎患者的临床资料、影像资料和治疗方法.结果 31例经抗生素治疗无效的患者,通过支气管镜肺活检病理或经皮肺穿刺病理除外结核、真菌、化脓性炎、肺癌而拟诊机化性肺炎24例,无病理检查结果而经激素治疗有效拟诊7例.21例患者具有典型机化性肺炎CT表现,所有病例均经短期（6～14d）激素治疗后影像学结果明显改善.随访6～25个月,复发6例,均发生在激素减量过快或停药患者中.结论 临床上经抗生素治疗无效、结合临床影像学特点、病理检查除外其他疾病是拟诊机化性肺炎的重要指标;对于无病理检查患者短期激素治疗有效有助于诊断.过早激素减量容易导致复发.     

Molecular Dynamics Simulation Study on the Interactions of Mixed Cationic/Anionic Collectors on Muscovite (001) Surface in Aqueous Solution

In this study, the adsorption mechanisms of dodecylamine hydrochloride(DDAHC), sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate(SDBS), and their mixed anionic/cationic collectors at ten different molar ratios on a muscovite (Mcv) surface in neutral aqueous solution were assessed by molecular dynamics simulations (MDS). According to the snapshot, interaction energy, radial distribution function (RDF), and density profile between the Mcv surface and collector molecules, the individual DDAHC collector was an effective collector for the flotation of Mcv. The molar ratio of anionic/cationic collectors was determined to be an essential factor in the flotation recovery of Mcv. The DDAHC collector was involved in the adsorption of the mixed anionic/cationic collectors on the Mcv (001) surface, whereas SDS and SDBS collectors were co-adsorbed with DDAHC. The mixed cationic/anionic collector showed the best adsorption on the Mcv surface in a molar ratio of 2. Additionally, SDBS, which has one more benzene ring than SDS, was more likely to form spherical micelles with DDAHC, thus resulting in better adsorption on the Mcv surface. The results of micro-flotation experiments indicated that the DDAHC collector could improve the flotation recovery of Mcv in neutral aqueous solution, which was in agreement with MDS-derived findings. In conclusion, DDAHC alone is the optimum collector for Mcv flotation under the neutral aqueous conditions, while the mixture of DDAHC and SDBS collectors (molar ratio = 2:1) exhibits the similar flotation performance.     

Efficacy and Safety of Apatinib in Patients with Recurrent or Refractory Melanoma

BackgroundThe prognosis of patients with metastatic malignant melanoma is very poor and partly due to resistance to conventional chemotherapies. The study’s objectives were to assess the activity and tolerability of apatinib, an oral small molecule anti-angiogenesis inhibitor, in patients with recurrent advanced melanoma.MethodsThis was a single-arm, single-center phase II trial. The primary endpoint was progression-free survival (PFS) and the secondary endpoints were objective response rate (ORR), disease control rate (DCR), and overall survival (OS). Eligible patients had received at least one first-line therapy for advanced melanoma and experienced recurrence. Apatinib (500 mg) was orally administered daily.ResultsFifteen patients (V660E BRAF status: 2 mutation, 2 unknown, 11 wild type) were included in the analysis. The median PFS was 4.0 months. There were two major objective responses, for a 13.3% response rate. Eleven patients had stable disease, with a DCR of 86.7%. The median OS was 12.0 months. The most common treatment-related adverse events of any grade were hypertension (80.0%), mucositis oral (33.3%), hand-foot skin reaction (26.7%), and liver function abnormalities, hemorrhage, diarrhea (each 20%). The only grade ≥3 treatment-related adverse effects that occurred in 2 patients was hypertension (6.7%) and mucositis (6.7%). No treatment-related deaths occurred.ConclusionApatinib showed antitumor activity as a second- or above-line therapy in patients with malignant melanoma. The toxicity was manageable.ClinicalTrials.gov Identifier{"type":"clinical-trial","attrs":{"text":"NCT03383237","term_id":"NCT03383237"}}NCT03383237     

Fracture Mode Transition during Assembly of TC4 High-Lock Bolt under Tensile Load: A Combined Experimental Study and Finite Element Analysis

Fracture during the assembly process is an important failure mode for high-lock bolts used in the aviation industry, which greatly increases the potential of unpredictable accidents during service. In the current study, the underlying reasons for fracture during the assembly of a TC4 high-lock bolt was investigated using a tensile test and finite element analysis (FEA). The microstructure of the as-received bolt consisted of a high proportion of α phase, some β phase, and a small amount of α′ phase formed via martensite phase transformation during the rammer process. The experimental force–displacement curves revealed an average yield load of 55.9 kN and a breaking load of 67.65 kN. The corresponding yield strength was calculated to be 0.9 GPa, which was smaller than the standard value of TC4. This was attributed to the preload-induced stress concentration on the thread surface, leading to obvious strain hardening, which can lead to crack initiation. The effect of preload was further confirmed by the fractographies in which the initial crack was observed on the thread surface. The fractographies suggested that hybrid fracture occurred on the tensile loaded bolt. The initial failure was brittle fracture on the thread surface, transforming into ductile fracture in the screw. The results can contribute to understanding the effect of preload on the load carry capacity of high-lock bolts and provide a strategy to design its assembly specification.     

Rust Distribution of Non-Uniform Steel Corrosion Induced by Impressed Current Method

The non-uniform corrosion of steel bars is the main factor affecting the durability of concrete. The cracking pattern of concrete due to corrosion is closely related to the distribution of the corrosion products. Research on the thickness distribution of the rust layer and the cracking pattern of concrete under different influencing factors is of great significance in the prediction of the service life of existing reinforced concrete structures and the avoidance of the premature cracking of the reinforced concrete structures to be built. This paper studies the thickness distribution of the rust layer on the surface of single and multiple corroded reinforcements under non-uniform corrosion. The electrochemical analysis of the electrified corrosion process was carried out by using the finite element analysis software, and the distribution of the current density was obtained. The effects of geometric parameters, steel bar position, and steel bar spacing and shape on the corrosion expansion cracking pattern were studied. The results indicated that as the position of the steel bar differed, the crack pattern of the concrete changed, depending on the number of corrosion peaks (i.e., the maximum thickness of the rust layer). In terms of the corner-located steel, the number of corrosion peaks varied in the cases of different geometrical parameters (i.e., the diameter of the steel bar and the distance between the steel bars and the stainless steel wire). Nevertheless, the critical corrosion degrees of the side-located and corner-located steel bars, with respect to the cracking of the outer concrete surface, were basically the same. Additionally, the ribbed steel bar presented a lower critical corrosion degree than that of the plain steel bar, while little influence was exhibited with the varying angles of the rib.     

Ultra-High-Performance Concrete (UHPC): A State-of-the-Art Review

The interest of researchers in UHPC has increased over the past decade. It is crucial to understand the structural behavior of reinforced UHPC (R/UHPC) components under various loading conditions before they can be used as a replacement for conventional concrete. Although several studies on ultra-high-performance concrete (UHPC) have been conducted, the knowledge is scattered, and no one can easily judge the performance and methodology of UPHC. Therefore, the purpose of this study was to review the research studies already carried out on UHPC. The review focuses on the materials’ physical and chemical composition, mechanical and durability characteristics, fire resistance, and environmental benefits of UHPC. Design considerations for effectively utilizing UHPC in structural elements are also presented. The best UHPFRC mixture is obtainable with a steel fiber content of 2–3% and a water-to-cement ratio of 0.2–0.3. The review also discusses the essentials recommendation for future research on UHPC.