3,564 research outputs found
Numerical Analysis of the Influence of Bolt Set on the Shear Resistance of Jointed Rock Masses
Bolt reinforcement is a standard reinforcement method for jointed rock masses. However, regarding rock anchoring, the mechanical characteristics of the joint surface, as well as the angle between the bolt and the joint sliding surface, are important factors that affect rock support. Therefore, to understand the influence of a set angle, length, normal load, and other conditions that affect the shear strength of bolt joints, this study uses numerical software to establish the shear sliding model of bolt rock masses and analyzes the influence of the setting conditions of the bolt on the shear strength of a bolt rock mass, which can be done by changing the setting method of the bolt and normal mechanical conditions of the sliding surface. The results show that the shear strength of the anchor joint is not affected after the anchor reaches a certain length. The angle of the anchor strongly influences the shear strength of the anchor joint, and the shear strength curve is V-shaped, where the anchor angle is less than 90°. Moreover, the shear strength curve indicates a downward trend when the anchor angle is greater than 90°, and the shear strength of the anchorage joint increases with the increase of the normal load. Under the same anchor length (4 cm) in the anchor angle and shear strength coordinate system, the shear strength curve of the single anchor is above the shear strength curve of the double anchor, which is exclusively in the local anchor angle section under the condition of a large normal load and a large anchor angle. The shear strength curve of the double anchor is above the shear strength curve of the single anchor
Deltaline from Delphinium delavayi Franch
The title compound [systematic name: 6β,10-dihydroxy-1α,14α,16β-trimethoxy-4-methyl-7β,8-(methylenedioxy)-20-ethylaconitan-6-yl acetate], C27H41NO8, is a C19-diterpenoid alkaloid and a major diterpenoid alkaloid component of the roots of Delphinium delavayi Franch. var. pogonanthum (Hand.-Mazz.) W. T. Wang. The molecule has a lycoctonine carbon-atom skeleton with four six-membered rings and three five-membered rings among; three of the six-membered rings adopt chair conformations with the fourth adopting a boat conformation while all of the five-membered rings exhibit envelope conformations. Intermolecular O—H⋯O hydrogen bonding is present in the crystal structure
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Linezolid and Rifampicin Combination to Combat cfr-Positive Multidrug-Resistant MRSA in Murine Models of Bacteremia and Skin and Skin Structure Infection.
Linezolid resistance mediated by the cfr gene in MRSA represents a global concern. We investigated relevant phenotype differences between cfr-positive and -negative MRSA that contribute to pathogenesis, and the efficacy of linezolid-based combination therapies in murine models of bacteremia and skin and skin structure infection (SSSI). As a group, cfr-positive MRSA exhibited significantly reduced susceptibilities to the host defense peptides tPMPs, human neutrophil peptide-1 (hNP-1), and cathelicidin LL-37 (P < 0.01). In addition, increased binding to fibronectin (FN) and endothelial cells paralleled robust biofilm formation in cfr-positive vs. -negative MRSA. In vitro phenotypes of cfr-positive MRSA translated into poor outcomes of linezolid monotherapy in vivo in murine bacteremia and SSSI models. Importantly, rifampicin showed synergistic activity as a combinatorial partner with linezolid, and the EC50 of linezolid decreased 6-fold in the presence of rifampicin. Furthermore, this combination therapy displayed efficacy against cfr-positive MRSA at clinically relevant doses. Altogether, these data suggest that the use of linezolid in combination with rifampicin poses a viable therapeutic alternative for bacteremia and SSSI caused by cfr-positive multidrug resistant MRSA
Effect of congenital ptosis on astigmatism and axis length
AIM: To investigate the effects of congenital ptosis degree on total astigmatism, corneal astigmatism, intraocular astigmatism and axis length, and to discuss the relation with amblyopia. <p>METHODS: Fifty patients(100 eyes)with congenital ptosis were selected and divided into four groups: 33 eyes in group Ⅰ(normal); 20 eyes in group Ⅱ(mild); 17 eyes in group Ⅲ(moderate); 30 eyes in group Ⅳ(severity). Firstly, they received standardized medical optometry. Absolute value of astigmatism was recorded as total astigmatism. Then, corneal topography was used to measure double eyes for at least 3 times, and the best results were used to record the SimK. Define absolute value of △SimK as corneal astigmatism. Finally, axial length was measured for 5 times by A super-measurement, and take the mean value. Formula: intraocular astigmatism=total astigmatism-corneal astigmatism.<p>RESULTS: There was a significance difference between total astigmatism and cornea astigmatism(<i>P</i>=0.000, 0.002<0.05). Also they were positive correlation with severity of ptosis(Spearman <i>r</i><sub>s</sub>=0.514, 0.721,<i>P</i><0.05), but there was not significance difference in axial orientation, intraocular astigmatism and axial length(all <i>P</i>>0.05). The axial orientation, intraocular astigmatism had no correlation with severity of ptosis.<p>CONCLUSION: The congenital ptosis affects on eye astigmatism through the change of cornea astigmatism, which is related to severity of ptosis, but has no effect on axial length. The rate of amblyopia is higher than normal on congenital ptosisespecially severity. Amblyopia is related to high astigmatism which is moderate astigmatism with rule
Overexpression of long non-coding RNA NORAD promotes invasion and migration in malignant melanoma via regulating the MIR-205-EGLN2 pathway.
Growing evidence suggests that long non-coding RNAs NORAD and miR-205 play a significant role in regulating cancer progression and metastasis. In this study, high expression of NORAD was firstly observed in melanoma tissues and human malignant melanoma cell lines, our aim was to study the interaction of them in the process of invasion and migration of malignant melanoma cells. NORAD, miR-205, and EGLN2 mRNA level in MM cells was detected by qRT-PCR. In situ hybridization (ISH) was performed to detect NORAD expression in MM tissues specimens. Effects of NORAD and miR-205 on Prolyl hydroxylase 2 (EGLN2) expression was explored by western blot in MM cells line. Dual-luciferase reporter assay was performed to verify the interaction relationship between NORAD and miR-205, as well as, miR-205 and EGLN2. Transwell assay was conducted to explore the effects of NORAD and miR-205 in vitro. Xenografts in nude mice experiment were used to confirm the role of NORAD and miR-205 in vivo. In vitro, NORAD knockdown significantly inhibited migration and invasion of malignant melanoma cells and elevated the expression of miR-205, there was an interaction between miR-205 and NORAD in the RNA-induced silencing complex. Upregulation of miR-205 induced significant inhibition of migratory and invasive ability compared with the scrambled control. However, downregulating NORAD largely reversed this effect. Furthermore, the regulatory effects of miR-205 on EGLN2 levels and the induction of endoplasmic reticulum stress were reversed by NORAD. In vivo, deletion of miR-205 induced tumor growth in nude mice. NORAD may play critical roles in tumorigenesis and progression of malignant melanoma by regulating of the miR-205-EGLN2 pathway, and may serve as a new therapeutic target
Vasopressin and epinephrine versus epinephrine in management of patients with cardiac arrest: a meta-analysis
Objective. A combination of vasopressin and epinephrine may be more effective than epinephrine alone in cardiopulmonary resuscitation (CPR), but evidence is lacking to make clinical recommendations. This meta-analysis compares the efficacy of vasopressin and epinephrine used together versus epinephrine alone in cardiac arrest (CA).
Methods. We searched MEDLINE and EMBASE for randomized trials comparing the efficacy of vasopressin and epinephrine versus epinephrine alone in adults with cardiac arrest. The primary outcome was the return of spontaneous circulation (ROSC) and the survival rate on admission and discharge .We also analyzed ROSC in subgroups of patients presenting with different arrest rhythms, such as asystole, pulseless electrical activity (PEA), ventricular fibrillation (VF).
Results. We analyzed 6 randomized trials out of 485 articles. We did not find evidence supporting the superiority of vasopressin and epinephrine used in combination, except for the survival rate at 24h 2.99 95% CI(1.43,6.28). No evidence supports the conclusion that vasopressin combined with epinephrine is better than epinephrine alone for ROSC, even amongst subgroups of patients.
Conclusion. This systematic review of the efficacy of vasopressin and epinephrine use found that its combined use is better for 24h survival rate but only in one study which included 122 patients. Further investigation will be needed to support the use of this combination for cardiac arrest management
Reduced T-cadherin expression and promoter methylation are associated with the development and progression of hepatocellular carcinoma
Random Walk on Multiple Networks
Random Walk is a basic algorithm to explore the structure of networks, which
can be used in many tasks, such as local community detection and network
embedding. Existing random walk methods are based on single networks that
contain limited information. In contrast, real data often contain entities with
different types or/and from different sources, which are comprehensive and can
be better modeled by multiple networks. To take advantage of rich information
in multiple networks and make better inferences on entities, in this study, we
propose random walk on multiple networks, RWM. RWM is flexible and supports
both multiplex networks and general multiple networks, which may form
many-to-many node mappings between networks. RWM sends a random walker on each
network to obtain the local proximity (i.e., node visiting probabilities)
w.r.t. the starting nodes. Walkers with similar visiting probabilities
reinforce each other. We theoretically analyze the convergence properties of
RWM. Two approximation methods with theoretical performance guarantees are
proposed for efficient computation. We apply RWM in link prediction, network
embedding, and local community detection. Comprehensive experiments conducted
on both synthetic and real-world datasets demonstrate the effectiveness and
efficiency of RWM.Comment: Accepted to IEEE TKD
Regulation of Type 2 Immunity in Myocardial Infarction
Type 2 immunity participates in the pathogeneses of helminth infection and allergic diseases. Emerging evidence indicates that the components of type 2 immunity are also involved in maintaining metabolic hemostasis and facilitating the healing process after tissue injury. Numerous preclinical studies have suggested regulation of type 2 immunity-related cytokines, such as interleukin-4, -13, and -33, and cell types, such as M2 macrophages, mast cells, and eosinophils, affects cardiac functions after myocardial infarction (MI), providing new insights into the importance of immune modulation in the infarcted heart. This review provides an overview of the functions of these cytokines and cells in the setting of MI as well as their potential to predict the severity and prognosis of MI
Function and mechanism of toll-like receptors in cerebral ischemic tolerance: from preconditioning to treatment
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