The role of tool offset on the microstructure and mechanical properties of Al/Cu friction stir welded joints

In this study, dissimilar butt joining of 6061 aluminum alloy and commercially pure copper via friction stir welding was performed with varying tool offset value. The mechanical properties were compared using transverse tensile testing. It was found that as the tool offset decreased from a position of 2 mm–0 mm, the ultimate tensile strength of the welded joint increased, and then decreased drastically when the offset was more than 1.6 mm. X-ray tomography results showed that an effective mechanical interlocking structure was formed with a chaotic interface along the joint line. In addition, in-situ tool temperatures measurement showed that the stir zone peak temperature was highly dependent on tool offset

Med-DANet V2: A Flexible Dynamic Architecture for Efficient Medical Volumetric Segmentation

Recent works have shown that the computational efficiency of 3D medical image (e.g. CT and MRI) segmentation can be impressively improved by dynamic inference based on slice-wise complexity. As a pioneering work, a dynamic architecture network for medical volumetric segmentation (i.e. Med-DANet) has achieved a favorable accuracy and efficiency trade-off by dynamically selecting a suitable 2D candidate model from the pre-defined model bank for different slices. However, the issues of incomplete data analysis, high training costs, and the two-stage pipeline in Med-DANet require further improvement. To this end, this paper further explores a unified formulation of the dynamic inference framework from the perspective of both the data itself and the model structure. For each slice of the input volume, our proposed method dynamically selects an important foreground region for segmentation based on the policy generated by our Decision Network and Crop Position Network. Besides, we propose to insert a stage-wise quantization selector to the employed segmentation model (e.g. U-Net) for dynamic architecture adapting. Extensive experiments on BraTS 2019 and 2020 show that our method achieves comparable or better performance than previous state-of-the-art methods with much less model complexity. Compared with previous methods Med-DANet and TransBTS with dynamic and static architecture respectively, our framework improves the model efficiency by up to nearly 4.1 and 17.3 times with comparable segmentation results on BraTS 2019.Comment: Accepted by WACV 202

Исследование прочности концевых фрез методом конечных элементов

В процессе исследования проводились: обзор и анализ научно-технической литературы по теме магистерской работы, формулирование цели и задач исследования прочности режущих пластин концевой фрезы, проведение экспериментов для измерений технологических и физических составляющих силы резании, исследование распределения контактных напряжений на передней и задней поверхностях острозаточенного и изношенного инструмента, анализ полученных эпюр, вывод эмпирических формул для расчёта эпюр контактных напряжений, исследование НДС режущей пластины фрезы, определение оптимальной геометрии режущей пластины при обработке разных материалов.In the course of probe were spent: the review and the assaying of the scientific and technical literature on a theme of master Diploma Thesis, a formulation of the purpose and research problems of strength of cutting inserts of an end mill, carry out experiments for measurements of technological and physical components of force cutting, research of distribution of contact stresses on a rake both flank surfaces of new and the worn out cutting tool, the assaying received epures, an output empirical formulas for calculation of contact stresses, probe of the SDC of a cutting plate of a mill, definition of optimum geometry of a cutting plate in machining of different materials

Modification of m5C regulators in sarcoma can guide different immune infiltrations as well as immunotherapy

BackgroundRecent studies have found that 5-methylcytosine (m5C) modulators are associated with the prognosis and treatment of cancer. However, the relevance of m5C modulators in sarcoma prognosis and the tumour microenvironment is unclear.MethodsWe selected 15 m5C regulators and performed unsupervised clustering to identify m5C modification patterns and differentially expressed genes associated with the m5C phenotype in The Cancer Genome Atlas (TCGA) sarcomas. The extent of immune cell infiltration in different clustering groups was explored using single-sample gene set enrichment analysis and estimation algorithms. A principal component analysis algorithm-based m5C scoring protocol was performed to assess the m5C modification patterns of individual tumors.ResultsWe identified two distinct m5C modification patterns in the TCGA sarcoma cohort, which possess different clinical outcomes and biological processes. Tumour microenvironment analysis revealed two groups of immune infiltration patterns highly consistent with m5C modification patterns, classified as immune inflammatory and immune desert types. We constructed m5C scores and found that high m5C scores were closely associated with leiomyosarcoma and other subtypes, and were associated with poorer prognosis, lower PD-L1 expression, and poorer immunotherapy outcomes. The best application was validated against the m5C database.ConclusionWe constructed an m5C score for sarcoma based on the TCGA database and identified a poorer prognosis in the high m5c score group. The stability and good prognostic predictive power of the m5C score was verified by an external database. We found that sarcomas in the low m5C score group may have a better response to immunotherapy

Targeted insertion of regulatory elements enables translational enhancement in rice

In-locus editing of agronomically-important genes to optimize their spatiotemporal expression is becoming an important breeding approach. Compared to intensive studies on mRNA transcription, manipulating protein translation by genome editing has not been well exploited. Here, we found that precise knock-in of a regulating element into the 5’UTR of a target gene could efficiently increase its protein abundance in rice. We firstly screened a translational enhancer (AMVE) from alfalfa mosaic virus using protoplast-based luciferase assays with an 8.5-folds enhancement. Then the chemically modified donor of AMVE was synthesized and targeted inserted into the 5’UTRs of two genes (WRKY71 and SKC1) using CRISPR/Cas9. Following the in-locus AMVE knock-in, we observed up to a 2.8-fold increase in the amount of WRKY71 protein. Notably, editing of SKC1, a sodium transporter, significantly increased salt tolerance in T2 seedlings, indicating the expected regulation of AMVE knock-in. These data demonstrated the feasibility of such in-locus editing to enhance protein expression, providing a new approach to manipulating protein translation for crop breeding

Predicting Progression of IgA Nephropathy: New Clinical Progression Risk Score

IgA nephropathy (IgAN) is a common cause of end-stage renal disease (ESRD) in Asia. In this study, based on a large cohort of Chinese patients with IgAN, we aim to identify independent predictive factors associated with disease progression to ESRD. We collected retrospective clinical data and renal outcomes on 619 biopsy-diagnosed IgAN patients with a mean follow-up time of 41.3 months. In total, 67 individuals reached the study endpoint defined by occurrence of ESRD necessitating renal replacement therapy. In the fully adjusted Cox proportional hazards model, there were four baseline variables with a significant independent effect on the risk of ESRD. These included: eGFR [HR = 0.96(0.95–0.97)], serum albumin [HR = 0.47(0.32–0.68)], hemoglobin [HR = 0.79(0.72–0.88)], and SBP [HR = 1.02(1.00–1.03)]. Based on these observations, we developed a 4-variable equation of a clinical risk score for disease progression. Our risk score explained nearly 22% of the total variance in the primary outcome. Survival ROC curves revealed that the risk score provided improved prediction of ESRD at 24th, 60th and 120th month of follow-up compared to the three previously proposed risk scores. In summary, our data indicate that IgAN patients with higher systolic blood pressure, lower eGFR, hemoglobin, and albumin levels at baseline are at a greatest risk of progression to ESRD. The new progression risk score calculated based on these four baseline variables offers a simple clinical tool for risk stratification

Effects of process parameters and carbon nanotubes content on microstructure and properties of laser cladding composite coatings using Ni-Ti-Cr-carbon nanotubes

The Ni-Ti-Cr-carbon nanotubes (CNTs) composite coatings was successfully fabricated by laser cladding. The optical microscope was used to observe the metallographic structure of the composite coating, the phase composition of the composite layer was detected by XRD, the microstructures of the composite coatings were observed by SEM, and the point distribution and line distribution of elements were analyzed by EDS. With the increase of laser specific energy (Es) and CNTs content, the TiC enhanced particles in the composite coatings evolves into coarse dendrites. Compared with the mild steel substrate, the microhardness and wear resistance of the composite coatings are obviously improved. The maximum microhardness obtained by the composite coating is approximately 5 times that of the mild steel substrate. The increase of Es and the excessive content of CNTs will reduce the microhardness and wear resistance of the composite coatings. The in situ synthesis of TiC particles not only enhance the microhardness of the composite coatings, but also improve the wear resistance of the coatings