Closed-Loop Magnetic Manipulation for Robotic Transesophageal Echocardiography

This paper presents a closed-loop magnetic manipulation framework for robotic transesophageal echocardiography (TEE) acquisitions. Different from previous work on intracorporeal robotic ultrasound acquisitions that focus on continuum robot control, we first investigate the use of magnetic control methods for more direct, intuitive, and accurate manipulation of the distal tip of the probe. We modify a standard TEE probe by attaching a permanent magnet and an inertial measurement unit sensor to the probe tip and replacing the flexible gastroscope with a soft tether containing only wires for transmitting ultrasound signals, and show that 6-DOF localization and 5-DOF closed-loop control of the probe can be achieved with an external permanent magnet based on the fusion of internal inertial measurement and external magnetic field sensing data. The proposed method does not require complex structures or motions of the actuator and the probe compared with existing magnetic manipulation methods. We have conducted extensive experiments to validate the effectiveness of the framework in terms of localization accuracy, update rate, workspace size, and tracking accuracy. In addition, our results obtained on a realistic cardiac tissue-mimicking phantom show that the proposed framework is applicable in real conditions and can generally meet the requirements for tele-operated TEE acquisitions.Comment: Accepted by IEEE Transactions on Robotics. Copyright may be transferred without notice, after which this version may no longer be accessibl

Self-patterning Gd nano-fibers in Mg-Gd alloys

Manipulating the shape and distribution of strengthening units, e.g. particles, fibers, and precipitates, in a bulk metal, has been a widely applied strategy of tailoring their mechanical properties. Here, we report self-assembled patterns of Gd nano-fibers in Mg-Gd alloys for the purpose of improving their strength and deformability. 1-nm Gd nano-fibers, with a 〈c〉-rod shape, are formed and hexagonally patterned in association with Gd segregations along dislocations that nucleated during hot extrusion. Such Gd-fiber patterns are able to regulate the relative activities of slips and twinning, as a result, overcome the inherent limitations in strength and ductility of Mg alloys. This nano-fiber patterning approach could be an effective method to engineer hexagonal metals

On the special oxidation mechanism of a Mg-Y-Al alloy contained LPSO phase at high temperatures

This work investigated the oxidation of Mg-11Y-1Al alloy in Ar-20%O2 at 500{\deg}through multiscale characterization. The results show that the network-like long-period stacking ordered(LPSO) phase decomposed into a needle-like LPSO phase and a polygonal Mg24Y5 phase. The needle-like LPSO phase resulted in the formation of a high-dense of needle-like oxide at the oxidation front of the area initially occupied by the network-like LPSO phase. The further inward oxygen would diffuse along the needle-like oxide-matrix interfaces and react with Y in the surrounding Mg matrix, resulting in the lateral growth of these needle-like oxides. Finally, the discrete needle-like oxides were interconnected to form a thicker and continuous oxide scale which could be more effective in hindering the elemental diffusion. Meanwhile, Al could partially enter the Y2O3 oxide scale and formed a strengthened (Y,Al)O oxide scale which could show a greater resistance to cracking and debonding

Lack of an association of miR-938 SNP in IDDM10 with human type 1 diabetes

MicroRNAs (miRNAs) are a newly discovered type of small non-protein coding RNA that function in the inhibition of effective mRNA translation, and may serve as susceptibility genes for various disease developments. The SNP rs12416605, located in human type 1 diabetes IDDM10 locus, changes the seeding sequence (UGU[G/A]CCC) of miRNA miR-938 and potentially alters miR-938 targets, including IL-16 and IL-17A. In an attempt to test whether miR-938 may be a susceptibility gene for IDDM10, we assessed the possible association of the miR-938 SNP with T1D in an American Caucasian cohort of 622 patients and 723 healthy controls by TaqMan assay. Our current data do not support the association between the SNP in miR-938 and type 1 diabetes

Salinity appears to be the main factor shaping spatial COI diversity of Corbicula lineages within the Chinese Yangtze River Basin

info:eu-repo/semantics/publishe

Ksak: A high-throughput tool for alignment-free phylogenetics

Phylogenetic tools are fundamental to the studies of evolutionary relationships. In this paper, we present Ksak, a novel high-throughput tool for alignment-free phylogenetic analysis. Ksak computes the pairwise distance matrix between molecular sequences, using seven widely accepted k-mer based distance measures. Based on the distance matrix, Ksak constructs the phylogenetic tree with standard algorithms. When benchmarked with a golden standard 16S rRNA dataset, Ksak was found to be the most accurate tool among all five tools compared and was 19% more accurate than ClustalW2, a high-accuracy multiple sequence aligner. Above all, Ksak was tens to hundreds of times faster than ClustalW2, which helps eliminate the computation limit currently encountered in large-scale multiple sequence alignment. Ksak is freely available at https://github.com/labxscut/ksak

Unveiling precipitation behavior in Mg-Y based alloys

Mg-Y based alloys exhibit a promising combination of strength and deformability through tuning precipitation and solute strengthening mechanisms and tailoring the activity of non-basal dislocations. Understanding the precipitation sequence of Mg-Y based alloys and its dependence on Yttrium concentration in the matrix will provide a guideline for fine tuning structure, morphology and distribution of precipitates in Mg-Y based alloys. In this paper, we explore the precipitation behaviors of Mg-11Y (wt%) and Mg-11Y-1Al (wt%) alloys using aberration-corrected scanning transmission electron microscopy, and rationalize the experimental observations based on first-principles density functional theory calculations. The precipitation sequence during ageing at 225 °C is identified to be SSSS → clusters/G.P. Zones →β′ (Mg7Y) → β′′/βt′′ (Mg3Y). A novel βt′′ phase forms through in-situ transformation from the β′ phase, which shares the same Mg3Y composition with D019-β′′ phase and exhibits the same cbco-structure as β′ phase in Mg-Y based alloys

Zyxin Inhibits the Epithelial-Mesenchymal Transition Process in Gastric Cancer by Upregulating SIRT1

Tumor development relies on the stemness of cancer stem cells, which is regulated by environmental cues. Previous studies have shown that zyxin can inhibit the expression of genes for embryonic stem cell status. In the present study, the expression levels of zyxin protein in cancer tissues and adjacent noncancerous tissues from 73 gastric cancer patients with different clinical stages were analyzed by Western blot. We showed that the relative expression levels of zyxin in gastric cancer tissues (cancer tissues/adjacent tissues) were significantly downregulated in advanced clinical stages. Overexpression of zyxin inhibited the stemness and epithelial-mesenchymal transition (EMT) processes in gastric cancer cells. Zyxin also inhibited the proliferation, migration, and invasion but increased the sensitivity of cancer cells to drugs. Overexpression of zyxin in MKN45 cells inhibited tumor growth in nude mice. We show that the interactions between zyxin and SIRT1 led to the upregulation of SIRT1, reduced acetylation levels of histone H3 K9 and K23, decreased transcription levels of SNAI 1/2, and inhibition of the EMT process. This study demonstrated that zyxin negatively regulates the progression of gastric cancer by inhibiting the stemness of cancer stem cells and EMT. Our findings shed new light on the pathogenesis of gastric cancer

Stevioside Prevents Wear Particle-Induced Osteolysis by Inhibiting Osteoclastogenesis and Inflammatory Response via the Suppression of TAK1 Activation

Aseptic loosening and periprosthetic osteolysis are the leading causes of total joint arthroplasty failure, which occurs as a result of chronic inflammatory response and enhanced osteoclast activity. Here we showed that stevioside, a natural compound isolated from Stevia rebaudiana, exhibited preventative effects on titanium particle-induced osteolysis in a mouse calvarial model. Further histological assessment and real-time PCR analysis indicated that stevioside prevented titanium particle-induced osteolysis by inhibiting osteoclast formation and inflammatory cytokine expression in vivo. In vitro, we found that stevioside could suppress RANKL-induced osteoclastogenesis and titanium particle-induced inflammatory response in a dose-dependent manner. Mechanistically, stevioside achieved these effects by disrupting the phosphorylation of TAK1 and subsequent activation of NF-κB/MAPKs signaling pathways. Collectively, our data suggest that stevioside effectively suppresses osteoclastogenesis and inflammatory response both in vitro and in vivo, and it might be a potential therapy for particle-induced osteolysis and other osteolytic diseases

Exploring risk transfer of human brucellosis in the context of livestock agriculture transition: A case study in Shaanxi, China

With the booming of worldwide agriculture intensification, brucellosis, one of the most neglected zoonotic diseases, has become an increasing challenge for global public health. Although the transmission patterns of human brucellosis (HB) have been studied in many regions, the dynamic transfer processes of risk and its driving factors remain poorly understood, especially in the context of agricultural intensification. This study attempted to explore the risk transfer of HB between the exact epidemic areas and the neighboring or distant low-risk areas to explain the impact of livestock agriculture intensification and foodborne infections on the transmission of HB in Shaanxi Province as a case study. We adopted multiple approaches, including test-based methods, model-based methods, and a geographical detector to detect the spatial-temporal dynamic changes of high-risk epidemic areas of HB at the county scale. We also quantitatively estimated how the related factors drove the risk transfer of the disease. Results confirmed the risk transfer pattern of HB with an expansion from north to south in Shaanxi Province and identified two primary transfer routes. In particular, in the traditional epidemic areas of the Shaanbei plateau, the farm agglomeration effect can significantly increase the risk of HB. Meanwhile, retail outlets for milk and dairy products were partially responsible for the foodborne infections of HB in the emerging epidemic areas of Xi'an. This study not only contributed helpful insights to support HB control and prevention in the rapid transition of livestock agriculture but also provided possible directions for further research on foodborne HB infections in urbanized areas