Shear mechanical response and deformation failure of F-type socket joint in a rectangular pipe jacking tunnel under different geologic conditions.

The shear mechanical properties of F-type socket joints in rectangular pipe jacking tunnels are currently unknown. To investigate the shear mechanical response and deformation failure of the F-type socket joint in rectangular pipe jacking tunnels under different foundation coefficients, a laboratory joint test and numerical simulation method were used, considering the structural features of the joint. The results showed that the deformation process of a joint subjected to shear consists of four stages: gap closure, elastic growth, shear strengthening, and yield failure. The ultimate shear capacity of the joint increases by 25% to 34% for every 3 mm increase in the steel ring thickness. The chamfer yield damage area comprises approximately 15% of the steel ring. The joint concrete crack first appears at the top of the socket joint, and the concrete damage area accounts for about 40% of the whole pipe section. The failure characteristics of the joint are primarily manifested as drum and warp of the steel ring or cracking of the weld, and the concrete at the joint is crushed. In practical engineering, the weld should not be located at the chamfer. The steel ring at the chamfer needs to be locally strengthened, and the chamfer and the reinforcement at the top and bottom need to be increased to improve the bearing capacity of the concrete.

[Herbal-moxa plaster for diarrhea type irritable bowel syndrome of spleen and kidney yang deficiency: a randomized controlled trial].

OBJECTIVE: To compare the clinical efficacy between herbal-moxa plaster and moxa-box moxibustion for diarrhea type irritable bowel syndrome (IBS-D) of spleen and kidney yang deficiency. METHODS: Eighty patients with IBS-D of spleen and kidney yang deficiency were randomly divided into a herbal-moxa plaster group and a moxa-box moxibustion group, 40 cases in each group. The patients in the two groups were treated with conventional acupuncture at Baihui (GV 20), Yintang (GV 24+), Zhongwan (CV 12) and bilateral Tianshu (ST 25), Yinlingquan (SP 9), and Taixi (KI 3), etc. In addition, the patients in the herbal-moxa plaster group were treated with herbal-moxa plaster (Wenyang Fuzheng ointment, composed of prepared monkshood, prepared evodia rutaecarpa, dried ginger, cinnamon, etc.) at Shenque (CV 8), Guanyuan (CV 4), Zhongwan (CV 12) and bilateral Tianshu (ST 25), Shenshu (BL 23) and Shangjuxu (ST 37); the patients in the moxa-box moxibustion group were treated with moxa-box moxibustion at the same acupoints as the herbal-moxa plaster group. The acupuncture-moxibustion treatment was provided once every other day for 4 weeks (14 treatments). Before and after treatment, the scores of clinical symptom of TCM, irritable bowel syndrome (IBS) symptom severity scale (IBS-SSS) and IBS quality of life scale (IBS-QOL) were compared between the two groups, and the clinical efficacy was evaluated. RESULTS: Compared with those before treatment, each item scores and total scores of clinical symptom of TCM, and IBS-SSS scores in the two groups were reduced after treatment (P<0.05). The abdominal bloating score, stool frequency score and total score of clinical symptom of TCM as well as IBS-SSS score in the herbal-moxa plaster group were lower than those in the moxa-box moxibustion group (P<0.05). Compared with those before treatment, the IBS-QOL scores in the two groups were increased after treatment (P<0.05), and the IBS-QOL score in the herbal-moxa plaster group was higher than that in the moxa-box moxibustion group (P<0.05). The total effective rate was 92.5% (37/40) in the herbal-moxa plaster group, which was higher than 85.0% (34/40) in the moxa-box moxibustion group (P<0.05). CONCLUSION: On the basis of conventional acupuncture treatment, herbal-moxa plaster could effectively improve the clinical symptoms and quality of life in IBS-D patients of spleen and kidney yang deficiency, and its efficacy is superior to that of moxa-box moxibustion.

Deacetylation mechanism and potential reversal strategy of long QT syndrome on hERG K+ channel under hypoxia.

Clinically, hypoxia is a major risk factor for long QT syndrome (LQTS), which is associated with many diseases, such as myocardial ischemia. LQTS can be caused by the deficiency of hERG, a potassium ion channel that plays a key role in cardiac repolarization. Modifications such as acetylation of histones or non-histone proteins can affect the protein expression. In the present study, we explored the mechanism underlying hypoxia-induced LQTS and a potential reversal strategy. Experiments were performed under hypoxia to determine transcriptional and post-transcriptional expression changes. We used real-time PCR, chromatin immunoprecipitation assay, and western blotting to determine the histones acetylation in the hERG gene and the mechanism. Molecular docking, western blotting, IP, and patch -clamp assay were performed to determine the acetylation and ubiquitination levels of hERG protein and the mechanism. hERG mRNA and protein expression were found to decrease under hypoxia. The histone deacetylation level increased under hypoxia at both H3K27 and H4 of the hERG gene. HDAC1 and HDAC2 are the key enzymes for the mechanism. HDAC6 directly interacts with hERG. The acetylation level of hERG decreased and the ubiquitination level of hERG increased under hypoxia. The inhibitors of HDAC1, HDAC2, and HDAC6 could reverse the reduction of hERG mRNA and hERG protein expression under hypoxia. In conclusion, deacetylation of hERG gene-associated histones and hERG protein might be the mechanisms for LQTS in patients with hypoxia, and the inhibition of HDAC1, HDAC2, and HDAC6 might be a promising reversal strategy for reducing hERG expression under different pathological conditions.

Analysis of the Status and Trends of Chinese Clinical Practice Guideline Development Between 2010 and 2020: A Systematic Review.

Objective: This study aimed to systematically review the status and trends of Chinese clinical practice guidelines (CPGs) during the time period 2010-2020 and explore their methodological characteristics. Then, based on the strengths and weaknesses in development, offer several recommendations for the quality improvement which will serve as a reference for the users and developers of CPG. Introduction: With the development of evidence-based medicine (EBM), the CPGs play an increasingly important role in healthcare decision-making both in China and worldwide. Inclusion criteria: The CPGs that have been used to help the health professionals in the healthcare decision-making were included. Methodology: The China National Knowledge Infrastructure (CNKI) and WanFang databases were searched from 2010 to 2020 for the studies describing the general and methodological characteristics of Chinese CPGs. Comparisons of the methodological characteristics between the groups were conducted using the chi-square test or Fisher's exact test. The M-K test was adopted to identify the monotonically increasing or decreasing trends of methodological characteristics over the timespan. Results: A total of 2,654 CPGs fulfilled the inclusion criteria. The quantity and quality of the guidelines developed in China have improved over the time span. From 2010 to 2020,the guidelines had differing characteristics and covered a wide range of subjects. In total, 2,318(87.34%) guidelines focused on Western Medicine. Eight (0.30%) had been developed for patient versions of guidelines, 10(0.38%) were tentative guidelines, and 16(0.60%) were rapid advice guidelines. Medical specialty societies (including their branches) (71.1%) were the main guideline makers. The most addressed diseases were neoplasms (14.43%). The target population is mainly adults (84.97%). The methodological quality of consensus-based (CB)-CPGs was obviously lower than evidence-based (EB)-CPGs. Except for the item, "recommendations were based on evidence of systematic reviews," there were statistical differences in all other methodological items between the EB-CPGS and CB-CPGS (P < 0.01). Higher methodological quality has been observed in EB-CPGs. All the data relating to the methodological characteristics indicated that higher methodological quality was present in the guidelines using GRADE (P < 0.01). Conclusion: The quantity and quality of the guidelines developed in China have improved between 2010 and 2020. CB-CPGs have also paid attention to the methodology quality, but obviously, this is lower than that in the EB-CPGs.

Rutaecarpine targets hERG channels and participates in regulating electrophysiological properties leading to ventricular arrhythmia.

Drug-mediated or medical condition-mediated disruption of hERG function accounts for the main cause of acquired long-QT syndrome (acLQTs), which predisposes affected individuals to ventricular arrhythmias (VA) and sudden death. Many Chinese herbal medicines, especially alkaloids, have risks of arrhythmia in clinical application. The characterized mechanisms behind this adverse effect are frequently associated with inhibition of cardiac hERG channels. The present study aimed to assess the potent effect of Rutaecarpine (Rut) on hERG channels. hERG-HEK293 cell was applied for evaluating the effect of Rut on hERG channels and the underlying mechanism. hERG current (IhERG ) was measured by patch-clamp technique. Protein levels were analysed by Western blot, and the phosphorylation of Sp1 was determined by immunoprecipitation. Optical mapping and programmed electrical stimulation were used to evaluate cardiac electrophysiological activities, such as APD, QT/QTc, occurrence of arrhythmia, phase singularities (PSs), and dominant frequency (DF). Our results demonstrated that Rut reduced the IhERG by binding to F656 and Y652 amino acid residues of hERG channel instantaneously, subsequently accelerating the channel inactivation, and being trapped in the channel. The level of hERG channels was reduced by incubating with Rut for 24 hours, and Sp1 in nucleus was inhibited simultaneously. Mechanismly, Rut reduced threonine (Thr)/ tyrosine (Tyr) phosphorylation of Sp1 through PI3K/Akt pathway to regulate hERG channels expression. Cell-based model unables to fully reveal the pathological process of arrhythmia. In vivo study, we found that Rut prolonged QT/QTc intervals and increased induction rate of ventricular fibrillation (VF) in guinea pig heart after being dosed Rut for 2 weeks. The critical reasons led to increased incidence of arrhythmias eventually were prolonged APD90 and APD50 and the increase of DF, numbers of PSs, incidence of early after-depolarizations (EADs). Collectively, the results of this study suggest that Rut could reduce the IhERG by binding to hERG channels through F656 and Y652 instantaneously. While, the PI3K/Akt/Sp1 axis may play an essential role in the regulation of hERG channels, from the perspective of the long-term effects of Rut (incubating for 24 hours). Importantly, the changes of electrophysiological properties by Rut were the main cause of VA.

A novel polysaccharide from Dendrobium devonianum serves as a TLR4 agonist for activating macrophages.

Dendrobium devonianum has been used as herbal medicines and nutraceutical products since ancient time in China. However, its chemical composition and pharmacological mechanisms are not fully known. In present studies, by chemical purification and characteristic identification, we discovered a novel polysaccharide from D. devonianum, which was designated as DvP-1 with molecular weights of 9.52 × 104 Da. DvP-1 is a homogeneous heteropolysaccharide consisting of D-mannose and d-glucose in the molar ration of 10.11: 1. The main glycosidic linkages were ß-1, 4-Manp, which were substituted with acetyl groups at the O-2, O-3 and/or O-6 positions. DvP-1 was found to directly stimulate the activation of macrophages in vitro, as evidenced by inducing morphologic change, thereby promoting the production of cytokines TNF-α, IL-6 and NO, and enhancing the pinocytic activity of macrophages. By establishing a zebrafish model, we also found that DvP-1 could alleviate vinorelbine-induced decrease of macrophages in vivo. Further findings indicated that DvP-1 activated macrophages through several toll-like receptors (TLRs), but mainly through TLR4. DvP-1 served as a TLR4 agonist and induced ERK, JNK, p38, and IκB-α phosphorylation, suggesting the activation of MAPK and NFκB signaling pathways downstream of TLR4. These findings could help us further understand the immunomodulating effects of D. devonianum in Chinese medicines or health foods for immunocompromised persons. They also show the medicinal value of DvP-1 for the treatment of cancer and infectious diseases caused by TLR4 dysfunction.

[Cloning short gene fragment and constructing recombinant plasmid based on restoration of antibiotic resistance].

Molecular cloning is one of the most important and widely used technologies in molecular biology research. Generally, the target DNA fragment and the vector are separately digested by restriction enzyme, then purified and recovered, and then ligated with DNA-ligase. For some very short gene fragments (<300 bp), the recovery efficiency of the purified fragment is very low after digestion and cleavage, leading to the difficulty in its inserting into the expression vector. To address this issue, we developed a cloning method based on restoration of antibiotic resistance in constructing recombinant plasmid, which proved highly efficient in cloning very short gene fragments.

Maximizing lipophilic efficiency: the use of Free-Wilson analysis in the design of inhibitors of acetyl-CoA carboxylase.

This paper describes the design and synthesis of a novel series of dual inhibitors of acetyl-CoA carboxylase 1 and 2 (ACC1 and ACC2). Key findings include the discovery of an initial lead that was modestly potent and subsequent medicinal chemistry optimization with a focus on lipophilic efficiency (LipE) to balance overall druglike properties. Free-Wilson methodology provided a clear breakdown of the contributions of specific structural elements to the overall LipE, a rationale for prioritization of virtual compounds for synthesis, and a highly successful prediction of the LipE of the resulting analogues. Further preclinical assays, including in vivo malonyl-CoA reduction in both rat liver (ACC1) and rat muscle (ACC2), identified an advanced analogue that progressed to regulatory toxicity studies.

(3R,4S)-4-(2,4,5-Trifluorophenyl)-pyrrolidin-3-ylamine inhibitors of dipeptidyl peptidase IV: synthesis, in vitro, in vivo, and X-ray crystallographic characterization.

A series of pyrrolidine based inhibitors of dipeptidyl peptidase IV were developed from a high throughput screening hit for the treatment of type 2 diabetes. Potency, selectivity, and pharmacokinetic properties were optimized resulting in the identification of a pre-clinical candidate for further profiling.