Design crystallographic ordering in NbTa0.5TiAlx refractory high entropy alloys with strength-plasticity synergy

To make up for the poor strength of high plasticity NbTa0·5Ti refractory medium entropy alloys (MEAs), light metal Al was introduced as alloying element. In this work, the NbTa0·5Ti-Alx (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0) series non-isoatomic refractory high entropy alloys (RHEAs) were prepared by arc melting, and phase equilibrium was predicted by CALPHAD. The effects of Al content and annealing temperature on microstructure and phase evolution, and its mechanical properties were studied. The NbTa0·5Ti-Alx alloys changed from single phase BCC to two-phase A2+B2 crystal structure after adding Al. The hardness and strength of the as-cast alloys are increased by the solution strengthening and precipitation strengthening effect, but the brittleness is increased. The precipitation of Laves of plate-like NbAlTi2 and finer-scale A15 of (needle, particle)-like AlTi3 precipitates at and near grain boundaries after annealing. Higher annealing temperature is beneficial to eliminate dendrites formed by element segregation in the arc melting cooling process and promote grain growth (up to ∼200 μm). This work designed a new alloys with excellent compression plasticity and enriched the field of composition design and aging treatment of the Al-containing second generation RHEAs， so that their microstructure can be better controlled to achieve a balance of strength and plasticity

Gallie technique versus atlantoaxial screw-rod constructs in the treatment of atlantoaxial sagittal instability: a retrospective study of 49 patients

Abstract Background The objectives of this study are to investigate the clinical curative effect of Gallie technique and atlantoaxial screw-rod constructs (SRC) on atlantoaxial sagittal instability and determine the indication of Gallie technique. Methods Data of 49 patients with atlantoaxial sagittal instability from February 2008 to May 2015 were analyzed retrospectively. The visual analog scale (VAS) score and the neck disability index (NDI) were used to evaluate the curative effect. Postoperative radiological outcomes were used to evaluate the stability of atlantoaxial joint and bone fusion. Perioperative parameters such as blood loss, operation time, radiographic exposure times, and hospital expense were also recorded and analyzed. Results Forty-nine patients (36 men and 13 women) were included in this study. The mean age was 41.4 ± 8.9 (range from 19 to 64). All patients were followed up for 24–67 months. Among these patients, 25 of these patients underwent Gallie surgery and 24 underwent SRC surgery. The pain in the occipitocervical area of all the patients has been relieved. NDI scores and VAS scores were lower in Gallie group than in SRC group in early postoperative period. The proportion of the patients who achieved good bone fusion within 3 months after operation was 88.0% (22/25) in the Gallie group and 100% (24/24) in the SRC group. The Gallie group is lower than the SRC group in blood loss, operation time, radiographic exposure times, and hospital expense. Statistical difference was observed between the two groups. Conclusions For patients with atlantoaxial instability who has (1) the atlantodental interval (ADI) which is bigger than 5 mm on lateral flexion-extension X-ray, or Anderson-D’Alonzo type II odontoid fracture, (2) no asymmetry between odontoid process and lateral mass on open-mouth anterior-posterior X-ray, and (3) no dislocation of lateral mass joint on the CT 3D reconstruction, Gallie technique can be chosen as a safe and effective method if atlantoaxial reduction can be achieved preoperatively. Compared with SRC, Gallie technique can relieve the pain in the occipitocervical area earlier and it can shorten operation time and reduce intraoperative bleeding, radiographic exposure times, and hospital expense effectively. However, for patients with irreducible atlantoaxial dislocation, the Gallie technique should be used with caution

Prediction model of critical liquid‐carrying gas velocity for high gas‐to‐liquid ratio gathering pipelines

As the pressure and temperature of natural gas pipelines decreases during operation, water and condensate accumulates form in the low areas of the pipelines, affecting the operational efficiency of the pipelines and even corroding them. The critical gas velocity is a key factor in predicting liquid loading onset in the pipeline, so that appropriate measures can be taken in advance and hazards can be reduced. This paper proposes a model for predicting pipeline liquid loading onset based on the liquid film and wall shear stress of zero, and applicable to different pipe diameters and different inclination angles. This model provides a more simplified and comprehensive prediction of pipeline fluid loading than other models with complex calculations. The critical gas velocity in this model is a function of the liquid holding rate rather than the liquid film thickness, and the critical gas velocity prediction in a phase-inclined pipe is carried out by an improved Belfroid angle correction term. The experimental data, field data and seven models in the published literature were compared and validated, and the errors were judged. The results showed that the new model outperformed the other models in terms of absolute mean error at full inclination angle, and was able to predict the pipeline liquid loading accurately

The Preliminary Study on the Mechanism about Piperine Regulating the Knee Osteoarthritis Based on Network Pharmacological Methods

Abstract:Objective: To explore the target of anti-knee osteoarthritis (KOA) in the effective chemical compounds of piper longum L based on network pharmacological methods.Methods: The active chemical compounds of piper longum L were collected employing database retrieval on TCMSP, TCM-PTD, and literature mining. The Swiss Target Prediction service predicts the targets of active chemical compounds, and at the same time, the targets of the drugs treating knee osteoarthritis were collected by retrieving the OMIM and CTD databases. The targets were subjected to an alignment analysis to screen out piperine and we simulated the binding sites in vivo of compounds and proteins via AutoDock. After that, the rat models of knee osteoarthritis were established. The rats in model groups were given piperine treatment. The verification of the anti-KOA target PPARG and MAPK1 was done by Western blot and co-immunoprecipitation.Results: Nine active ingredients were predicted. According to Lipinski\u27s rule, piperine was speculated as a possible active ingredient. According to the possible targets of piperine and the KOA\u27s possible targets, three co-targets of them were confirmed, PPARG and MAPK1 were related to knee osteoarthritis (KOA). Molecular docking results show that piperine can hinder the binding of PPARG protein ARG-212 and GLN-420 amino-acid residues to each other. After 20 weeks of piperine treating, Western blot found that piperine can significantly increase the expression level of PPARG and reduce the expression level of MAPK1 in model rats. The endogenous interaction between PPARG and MAPK1 was verified by co-immunoprecipitation.Conclusion: Piper longum L can regulate the progression of knee osteoarthritis (KOA) by its active ingredient piperine，can affect the expression of PPARG and MAPK1 proteins, and PPARG and MAPK1 proteins have endogenous interactions.</p

Over-expression of PUMA correlates with the apoptosis of spinal cord cells in rat neuropathic intermittent claudication model.

BACKGROUND: Neuropathic intermittent claudication (NIC) is a typical clinical symptom of lumbar spinal stenosis and the apoptosis of neurons caused by cauda equina compression (CEC) has been proposed as an important reason. Whereas, the factors and the mechanism involved in the process of apoptosis induced by CEC remain unclear. METHODOLOGY AND RESULTS: In our modified rat model of NIC, a trapezoid-shaped silicon rubber was inserted into the epidural space under the L5 and L6 vertebral plate. Obvious apoptosis was observed in spinal cord cells after compression by TUNEL assay. Simultaneously, qRT-PCR and immunohistochemistry showed that the expression levels of PUMA (p53 up-regulated modulator of apoptosis) and p53 were upregulated significantly in spinal cord under compression, while the expression of p53 inhibitor MDM2 and SirT2 decreased in the same region. Furthermore, CEC also resulted in the upregulation of Bcl-2 pro-apoptotic genes expression and caspase-3 activation. With the protection of Methylprednisolone, the upregulation of PUMA and p53 expression as well as the decrease of MDM2 and SirT2 in spinal cord were partially rescued in western bolt analysis. CONCLUSIONS: These results suggest that over-expression of PUMA correlates with CEC caused apoptosis of spinal cord cells, which is characterized by the increase of p53, Bax and Bad expression. PUMA upregulation might be crucial to induce apoptosis of spinal cord cells through p53-dependent pathway in CEC

Glycan Imaging in Intact Rat Hearts and Glycoproteomic Analysis Reveal the Upregulation of Sialylation during Cardiac Hypertrophy

In the heart, glycosylation is involved in a variety of physiological and pathological processes. Cardiac glycosylation is dynamically regulated, which remains challenging to monitor in vivo. Here we describe a chemical approach for analyzing the dynamic cardiac glycome by metabolically labeling the cardiac glycans with azidosugars in living rats. The azides, serving as a chemical reporter, are chemoselectively conjugated with fluorophores using copper-free click chemistry for glycan imaging; derivatizing azides with affinity tags allows enrichment and proteomic identification of glycosylated cardiac proteins. We demonstrated this methodology by visualization of the cardiac sialylated glycans in intact hearts and identification of more than 200 cardiac proteins modified with sialic acids. We further applied this methodology to investigate the sialylation in hypertrophic hearts. The imaging results revealed an increase of sialic acid biosynthesis upon the induction of cardiac hypertrophy. Quantitative proteomic analysis identified multiple sialylated proteins including neural cell adhesion molecule 1, T-kininogens, and alpha(2)-macroglobulin that were upregulated during hypertrophy. The methodology may be further extended to other types of glycosylation, as exemplified by the mucin-type O-linked glycosylation. Our results highlight the applications of metabolic glycan labeling coupled with bioorthogonal chemistry in probing the biosynthesis and function of cardiac glycome during pathophysiological responses

Compressed nerve roots in patients with foot drop.

<p>L5 nerve root was most frequently affected. Double or triple roots compression was a common condition.</p

A 54-years-old man, diagnosed as LDH and left foot drop.

<p>(A) Preoperative radiography. (B) Preoperative mid-sagittal MRI showed LDH on L4-S1. (C) Preoperative axial MRI of L4-5 showed the left L5 nerve root compression. (D) Preoperative axial MRI of L5-S1 showed the left S1 nerve root compression. (E) Postoperative radiography.</p