Research on bearing capacity of cross-type truss boom with variable cross-section of Crawler cranes

The web crossed truss boom is one of the commonly used truss boom structures of crawler cranes. However, the existing calculations fail to consider the limiting effect of the web members' bending resistance on the chord members, and cannot give full play to the load-bearing capacity of the existing structure. This paper takes the top section of the Crawler crane truss boom as the research object. The single-span truss theoretical model is established according to Timoshenko's elastic stability theory. And the theoretical critical load of the variable cross-section boom is obtained with full consideration of the limitation of the web member's bending resistance on the chord members. The finite element method simulation model is compared and verified. Compared with a large number of simulation experiments and theoretical calculations, it can be concluded that the theoretical calculations in this article are highly consistent with the simulation results, verified the assumptions that the web members' bending resistance help to improve the bending resistance of the chord members, and this will provide certain reference to the engineering designers

Dimension Analysis-Based Model for Prediction of Shale Compressive Strength

The compressive strength of shale is a comprehensive index for evaluating the shale strength, which is linked to shale well borehole stability. Based on correlation analysis between factors (confining stress, height/diameter ratio, bedding angle, and porosity) and shale compressive strength (Longmaxi Shale in Sichuan Basin, China), we develop a dimension analysis-based model for prediction of shale compressive strength. A nonlinear-regression model is used for comparison. A multitraining method is used to achieve reliability of model prediction. The results show that, compared to a multi-nonlinear-regression model (average prediction error = 19.5%), the average prediction error of the dimension analysis-based model is 19.2%. More importantly, our dimension analysis-based model needs to determine only one parameter, whereas the multi-nonlinear-regression model needs to determine five. In addition, sensitivity analysis shows that height/diameter ratio has greater sensitivity to compressive strength than other factors

CoSe2/Co nanoheteroparticles embedded in Co, Nco-doped carbon nanopolyhedra/nanotubes as anefficient oxygen bifunctional electrocatalyst for Zn–air batteries

Transition metal selenide-based materials have been demonstrated as promising electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), yet the actual design of a highly efficient and stable electro-catalyst based on these materials still remains a long and arduous challenge. Herein, a predesigned hybrid Zn/Co zeolitic imidazole framework was used to fabricate CoSe2/Co nanoheteroparticles embedded within hierarchically porous Co, N co-doped carbonnanopolyhedra/nanotubes (CoSe2/Co@NC-CNTs) through a facile approach involving controlled carbonization and selenization procedures. As expected, the optimized CoSe2/Co@NC-CNT-1 displayed outstanding electrocatalytic performance for the ORR and OER, with an onset potential of 0.95 V vs. RHE, a half-wave potential of 0.84 V vs. RHE for ORR, and a potential of 1.69 V vs. RHE for OER at 10 mA cm−2. It also exhibited excellent long-term stability and methanol resistance ability, which were superior to commercial IrO2 and the commercial 20 wt% Pt/C catalyst. Notably, the assembled Zn–air battery with CoSe2/Co@NC-CNT-1 showed a low charge–discharge voltage gap (0.696 V at 10 mA cm−2) and a high peak power density (100.28 mW cm−2) with long-term cycling stability. These superior performances can be ascribed to the synergistic effects of the highly active CoSe2/Co nanoheterostructure, hierarchically porous structure with a large surface area, high electrical conductivity and uniform doping of the Co and

A new analgesic method, two-minute sciatic nerve press, for immediate pain relief: a randomized trial

<p>Abstract</p> <p>Background</p> <p>Current analgesics have drawbacks such as delays in acquisition, lag-times for effect, and side effects. We recently presented a preliminary report of a new analgesic method involving a two-minute sciatic nerve press, which resulted in immediate short-term relief of pain associated with dental and renal diseases. The present study investigated whether this technique was effective for pain associated with other disease types, and whether the relief was effective for up to one hour.</p> <p>Methods</p> <p>This randomized, placebo-controlled, parallel-group trial was conducted in four hospitals in Anhui Province, China. Patients with pain were sequentially recruited by participating physicians during clinic visits, and 135 patients aged 15 – 80 years were enrolled. Dental disease patients included those with acute pulpitis and periapical abscesses. Renal disease patients included those with kidney infections and/or stones. Tumor patients included those with nose, breast, stomach and liver cancers, while Emergency Room patients had various pathologies. Patients were randomly assigned to receive a "sciatic nerve press" in which pressure was applied simultaneously to the sciatic nerves at the back of both thighs, or a "placebo press" in which pressure was applied to a parallel region on the front of the thighs. Each fist applied a pressure of 11 – 20 kg for 2 minutes. Patients rated their level of pain before and after the procedure.</p> <p>Results</p> <p>The "sciatic nerve press" produced immediate relief of pain in all patient groups. Emergency patients reported a 43.5% reduction in pain (p < 0.001). Significant pain relief for dental, renal and tumor patients lasted for 60 minutes (p < 0.001). The peak pain relief occurred at the 10 – 20^thminutes, and the relief decreased 47% by the 60^thminutes.</p> <p>Conclusion</p> <p>Two minutes of pressure on both sciatic nerves produced immediate significant short-term conduction analgesia. This technique is a convenient, safe and powerful method for the short-term treatment of clinical pain associated with a diverse range of pathologies.</p> <p>Trial registration</p> <p>Current Controlled Trials ACTRN012606000439549</p

Genomic basis for RNA alterations in cancer.

Transcript alterations often result from somatic changes in cancer genomes1. Various forms of RNA alterations have been described in cancer, including overexpression2, altered splicing3 and gene fusions4; however, it is difficult to attribute these to underlying genomic changes owing to heterogeneity among patients and tumour types, and the relatively small cohorts of patients for whom samples have been analysed by both transcriptome and whole-genome sequencing. Here we present, to our knowledge, the most comprehensive catalogue of cancer-associated gene alterations to date, obtained by characterizing tumour transcriptomes from 1,188 donors of the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA)5. Using matched whole-genome sequencing data, we associated several categories of RNA alterations with germline and somatic DNA alterations, and identified probable genetic mechanisms. Somatic copy-number alterations were the major drivers of variations in total gene and allele-specific expression. We identified 649 associations of somatic single-nucleotide variants with gene expression in cis, of which 68.4% involved associations with flanking non-coding regions of the gene. We found 1,900 splicing alterations associated with somatic mutations, including the formation of exons within introns in proximity to Alu elements. In addition, 82% of gene fusions were associated with structural variants, including 75 of a new class, termed 'bridged' fusions, in which a third genomic location bridges two genes. We observed transcriptomic alteration signatures that differ between cancer types and have associations with variations in DNA mutational signatures. This compendium of RNA alterations in the genomic context provides a rich resource for identifying genes and mechanisms that are functionally implicated in cancer