Study of Alloying Process on 40Cr Surface with Electron Beam after Electroplated Cr Layer

The electroplated hard chromium coat was selected as precoating to improve surface properties of 40Cr. Then electron beam alloying process was experimentalized. The relation rules were summarized between alloying process parameters and overall surface properties by surface morphology observation, surface energy spectrum analysis, EDX analysis in section, and XRD. Experiment results showed that the microcracks appeared on surface of electron beam alloying specimen. Microcracks could disappear when the orthogonal experimental optimum process was used. The matrix metal elements diffused into metal coating surface after electron beam treatment. The maximum depth of alloyed layer could reach 8 μm after electron beam alloying treatment, and electron beam alloying process generated new residual austenite phase

Using random forest algorithm for glomerular and tubular injury diagnosis

ObjectivesChronic kidney disease (CKD) is a common chronic condition with high incidence and insidious onset. Glomerular injury (GI) and tubular injury (TI) represent early manifestations of CKD and could indicate the risk of its development. In this study, we aimed to classify GI and TI using three machine learning algorithms to promote their early diagnosis and slow the progression of CKD.MethodsDemographic information, physical examination, blood, and morning urine samples were first collected from 13,550 subjects in 10 counties in Shanxi province for classification of GI and TI. Besides, LASSO regression was employed for feature selection of explanatory variables, and the SMOTE (synthetic minority over-sampling technique) algorithm was used to balance target datasets, i.e., GI and TI. Afterward, Random Forest (RF), Naive Bayes (NB), and logistic regression (LR) were constructed to achieve classification of GI and TI, respectively.ResultsA total of 12,330 participants enrolled in this study, with 20 explanatory variables. The number of patients with GI, and TI were 1,587 (12.8%) and 1,456 (11.8%), respectively. After feature selection by LASSO, 14 and 15 explanatory variables remained in these two datasets. Besides, after SMOTE, the number of patients and normal ones were 6,165, 6,165 for GI, and 6,165, 6,164 for TI, respectively. RF outperformed NB and LR in terms of accuracy (78.14, 80.49%), sensitivity (82.00, 84.60%), specificity (74.29, 76.09%), and AUC (0.868, 0.885) for both GI and TI; the four variables contributing most to the classification of GI and TI represented SBP, DBP, sex, age and age, SBP, FPG, and GHb, respectively.ConclusionRF boasts good performance in classifying GI and TI, which allows for early auxiliary diagnosis of GI and TI, thus facilitating to help alleviate the progression of CKD, and enjoying great prospects in clinical practice

Mechanism Analysis of Spalling Defect on Rail Surface under Rolling Contact Conditions

Under the wheel/rail contact loading conditions, the microcracks on the rail surface propagate, leading to spalling defect or rail fracture and threatening the travelling safety of high-speed railway directly. In order to analyze the mechanism of the crack propagation on the rail surface, the calculation model of the wheel/rail contact fatigue was established, and the variation of the stress intensity factor at the crack tip when the crack length was increased from 0.1 mm to 2 mm was obtained. Based on the mixed-mode fracture criterion and Paris growth theory, the mechanism of the crack propagation on the rail surface was analyzed. The results show that when the microcrack grows to macrocrack, the mode of the fatigue crack on the rail surface is mixed including sliding mode and open mode. With the increase of the crack length, the stress intensity factor KI increases first and then decreases gradually, and the relative dangerous location of the open-mode crack moves from the inner edge of the contact area to the outer edge, while the factor KII is increasing during the whole propagation process, and the relative dangerous location of the sliding-mode crack remains unchanged basically. The main failure mode of crack is open during the initial stage and then transforms into sliding mode with the crack length increasing. The crack tends to propagate upward and leads to spalling defect when the crack length is between 0.3 and 0.5 mm. This propagation path is basically identical with the spalling path of the service rail. The research results will provide a basis for improving the antifatigue performance of rail and establishing the grinding procedure

The nuclear phosphatase SCP4 regulates FoxO transcription factors during muscle wasting in chronic kidney disease

Chronic kidney disease (CKD) and related inflammatory responses stimulate protein-energy wasting, a complication causing loss of muscle mass. Primarily, muscle wasting results from accelerated protein degradation via autophagic/lysosomal and proteasomal pathways, but mechanisms regulating these proteolysis pathways remain unclear. Since dephosphorylation of FoxOs regulates ubiquitin/proteasome protein metabolism, we tested whether a novel nuclear phosphatase, the small C-terminal domain phosphatase (SCP) 4, regulates FoxOs signaling and, in turn, muscle wasting. In cultured mouse myoblast cells, SCP4 overexpression stimulated proteolysis, while knockdown of SCP4 prevented the proteolysis stimulated by inflammatory cytokines. SCP4 overexpression led to nuclear accumulation of FoxO1/3a followed by increased expression of catabolic factors including myostatin, Atrogin-1, and MuRF-1, and induction of lysosomal-mediated proteolysis. Treatment of C2C12 myotubes with proinflammatory cytokines stimulated SCP4 expression in an NF-\u3baB-dependent manner. In skeletal muscle of mice with CKD, SCP4 expression was up-regulated. Similarly, in skeletal muscle of patients with CKD, SCP4 expression was significantly increased. Knockdown of SCP4 significantly suppressed FoxO1/3a-mediated expression of Atrogin-1 and MuRF-1 and prevented muscle wasting in mice with CKD. Thus, SCP4 is a novel regulator of FoxO transcription factors and promotes cellular proteolysis. Hence, targeting SCP4 may prevent muscle wasting in CKD and possibly other catabolic conditions

Alterations of gut microbiota in biopsy-proven diabetic nephropathy and a long history of diabetes without kidney damage

Abstract The gut microbiota is closely related to parenteral noncommunicable diseases through intestinal immunity and plays an important role in the occurrence of diabetes and diabetic nephropathy. The aim of the study was to understand the gut–kidney axis by an analysis of gut microbiota composition among patients with biopsy-proven diabetic nephropathy (DN), patients with type 2 diabetes for more than 10 years without kidney damage (DM), and healthy controls (NC). Thirty-five DN patients, 40 DM patients and 40 healthy subjects matched by age and sex were enrolled between January 2022 and December 2022. Baseline information and clinical parameters were collected. 16S rDNA sequencing was performed to characterize the gut microbiome and identify gut microbes that were differentially abundant between patients and healthy controls. The relationship between the relative abundance of specific bacterial taxa in the gut and clinical phenotype and pathological indicators was evaluated. Substantial differences were found in the richness of the gut microbiota and the variation in the bacterial population among DN patients, DM patients and healthy controls. DM patients could be accurately distinguished from age- and sex-matched healthy controls by variations in g_Clostridium-XVIII (AUC = 0.929), and DN patients could be accurately distinguished from age- and sex-matched healthy controls by variations in g_Gemmiger (AUC = 0.842). DN patients could be accurately distinguished from age- and sex-matched DM patients by variations in g_Flavonifractor or g_Eisenbergiella (AUC = 0.909 and 0.886, respectively). The gut microbiota was also closely related to clinical phenotypes and pathological indicators. The study of gut microbiota composition was explored to determine its relationship to the occurrence of DN and a long history of diabetes without kidney damage. The renal pathological progression of DN may be delayed by regulating changes in the gut microbiota

Perceptually enhanced bitplane coding for scalable audio

The MPEG-4 Scalable to Lossless (SLS) audio coding is recently being developed to provide a unified solution for high-compression perceptual audio coding and high-quality lossless audio coding. SLS provides efficient Fine Granular Scalable (FGS) coding from AAC core layer to lossless, and achieves reasonable perceptual quality at its scalable coding range using a sequential bit-plane scanning method, which minimizes the audio distortion according to the spectral shape of the core layer quantization errors. In this paper, it is shown that the perceptual quality performance of SLS at intermediate rates can be further improved by incorporating psychoacoustic model into the bit-plane coding process. In addition, it is also found that such an improvement can be achieved by slightly tweaking the original bit-plane coding process of SLS and hence preserving its nice features such as compatibility to lossless coding and low complexity. 1

Recent Progresses in Non-Dialysis Chronic Kidney Disease Patients with Hyperkalemia: Outcomes and Therapeutic Strategies

Chronic kidney disease (CKD) affects about 10% of the world’s population. Hyperkalemia is a life-threatening complication in patients with CKD, as it is associated with adverse cardiovascular and kidney outcomes. There are still many challenges and questions to address to improve the currently available therapeutic strategies to treat hyperkalemia, such as how to approach the emergency management of hyperkalemia. In recent years, in addition to novel oral potassium binders, great progress has been made in the application of novel kidney protective strategies, such as mineralocorticoid receptor antagonists and sodium–glucose cotransporter 2 inhibitors (SGLT2i) in hyperkalemia therapy. This review will discuss the recent advances from clinical trials in the effective management of hyperkalemia in non-dialysis CKD patients, enhancing the knowledge of physicians and internists concerning these newer agents and providing a helpful reference for clinical practice