166 research outputs found
A subset of co-expressed genes in Slug-based cancer mesenchymal transition signature remains coexpressed in normal samples in a tissue-specific manner
A recently identified gene expression signature of EMT markers containing the transcription factor Slug was found present in samples from many publicly available cancer gene expression datasets of multiple cancer types except leukemia. We also found many of these genes co-expressed in human cancer xenografted cells, but not in mouse stroma cells, suggesting that the signature is largely produced by cancer cells undergoing some type of EMT. Here we report that a partial signature consisting of a subset of the co-expressed genes of the full signature, including at least Slug (SNAI2), collagens COL1A1, COL1A2, COL3A1, COL6A3 and genes DCN and LUM, is also present in leukemia, in which case it is also strongly associated with the chemokine CXCL12 (aka SDF1). The same subset of co-expressed genes is also strongly present even in normal samples in a tissue-specific manner, with lowest expression in brain tissues and highest expression in reproductive system tissues. The full signature, with prominent presence of COL11A1, THBS2 and INHBA appears to be triggered in solid cancers particularly when cancer cells encounter adipocytes
Experimental Study of Pressure Loss in a 5 × 5–Rod Bundle With the Mixing Vane Spacer Grid
Axial and lateral pressure loss in a 5 × 5 rod–bundle with a split-type mixing vane spacer grid was experimentally measured using differential pressure transmitters at different sub-channel Reynolds numbers (Re) and orienting angles. The geometrical parameters of the 5 × 5–rod bundle are as follows: they have the same diameter (D = 9.5 mm) and pitch (p = 12.6 mm) as those of real fuel rods of a typical pressurized water reactor (PWR), with a sub-channel hydraulic diameter (D) of 11.78 mm. The characteristics and resistance models of pressure loss are discussed. The main axial pressure loss is caused by the spacer grid, and the spacer grid generates additional wall friction pressure loss downstream of the spacer grid. The lateral pressure loss shows strong correlations with orienting angles and distance from the spacer grid. The lateral pressure loss shows a sudden burst in the mixing vanes region and a slight augmentation at z = 3D. After 3D, the lateral pressure loss decays in an exponential way with distance from the spacer grid, and it becomes constant quickly at z = 20D
Arrayed van der Waals Vertical Heterostructures based on 2D GaSe Grown by Molecular Beam Epitaxy
Vertically stacking two dimensional (2D) materials can enable the design of
novel electronic and optoelectronic devices and realize complex functionality.
However, the fabrication of such artificial heterostructures in wafer scale
with an atomically-sharp interface poses an unprecedented challenge. Here, we
demonstrate a convenient and controllable approach for the production of
wafer-scale 2D GaSe thin films by molecular beam epitaxy. In-situ reflection
high-energy electron diffraction oscillations and Raman spectroscopy reveal a
layer-by-layer van der Waals epitaxial growth mode. Highly-efficient
photodetector arrays were fabricated based on few-layer GaSe on Si. These
photodiodes show steady rectifying characteristics and a relatively high
external quantum efficiency of 23.6%. The resultant photoresponse is super-fast
and robust with a response time of 60 us. Importantly, the device shows no sign
of degradation after 1 million cycles of operation. Our study establishes a new
approach to produce controllable, robust and large-area 2D heterostructures and
presents a crucial step for further practical applications
Magnetotransport properties of Cd3As2 nanostructures
Three-dimensional (3D) topological Dirac semimetal is a new kind of material
that has a linear energy dispersion in 3D momentum space and can be viewed as
an analog of graphene. Extensive efforts have been devoted to the understanding
of bulk materials, but yet it remains a challenge to explore the intriguing
physics in low-dimensional Dirac semimetals. Here, we report on the synthesis
of Cd3As2 nanowires and nanobelts and a systematic investigation of their
magnetotransport properties. Temperature-dependent ambipolar behavior is
evidently demonstrated, suggesting the presence of finite-size of bandgap in
nanowires. Cd3As2 nanobelts, however, exhibit metallic characteristics with a
high carrier mobility exceeding 32,000 cm2V-1s-1 and pronounced anomalous
double-period Shubnikov-de Haas (SdH) oscillations. Unlike the bulk
counterpart, the Cd3As2 nanobelts reveal the possibility of unusual change of
the Fermi sphere owing to the suppression of the dimensionality. More
importantly, their SdH oscillations can be effectively tuned by the gate
voltage. The successful synthesis of Cd3As2 nanostructures and their rich
physics open up exciting nanoelectronic applications of 3D Dirac semimetals.Comment: 18 pages, 5 figure
Association between cardiovascular risk factors and atrial fibrillation
BackgroundThe most prevalent sustained arrhythmia in medical practice, atrial fibrillation (AF) is closely associated with a high risk of cardiovascular disease. Nevertheless, the risk of AF associated with cardiovascular risk factors has not been well elucidated. We pooled all published studies to provide a better depiction of the relationship among cardiovascular risk factors with AF.MethodsStudies were searched in the MEDLINE, Web of Science, and EMBASE databases since initiation until January 15, 2022. Prospective cohort studies assessing the relationship a minimum of single cardiovascular risk factors to AF incidence were included if they contained adequate data for obtaining relative risks (RR) and 95% confidence intervals (CI). Random-effects models were utilized to perform independent meta-analyses on each cardiovascular risk factor. PROSPERO registry number: CRD42022310882.ResultsA total of 17,098,955 individuals and 738,843 incident cases were reported for data from 101 studies included in the analysis. In all, the risk of AF was 1.39 (95% CI, 1.30–1.49) for obesity, 1.27 (95% CI, 1.22–1.32) per 5 kg/m2 for increase in body mass index, 1.19 (95% CI, 1.10–1.28) for former smokers, 1.23 (95% CI, 1.09–1.38) for current smokers, 1.31 (95% CI, 1.23–1.39) for diabetes mellitus, 1.68 (95% CI, 1.51–1.87) for hypertension, and 1.12 (95% CI, 0.95–1.32) for dyslipidemia.InterpretationAdverse cardiovascular risk factors correlate with an increased risk of AF, yet dyslipidemia does not increase the risk of AF in the general population, potentially providing new insights for AF screening strategies among patients with these risk factors.Systematic Review Registrationhttps://www.crd.york.ac.uk/PROSPERO/, PROSPERO identifier (CRD42022310882)
Partial femoral head replacement: a new innovative hip-preserving approach for treating osteonecrosis of the femoral head and its finite element analysis
Purpose: Controversy remains regarding the optimal treatment for stage III Osteonecrosis of the femoral head (ONFH). This study presents, for the first time, the precise treatment of stage III ONFH using the “substitute the beam for a pillar” technique and performs a comparative finite element analysis with other hip-preserving procedures.Methods: A formalin-preserved femur of male cadavers was selected to obtain the CT scan data of femur. The proximal femur model was reconstructed and assembled using Mimics 20.0, Geomagic, and UG-NX 12.0 software with four different implant types: simple core decompression, fibula implantation, porous tantalum rod implantation, and partial replacement prosthesis. The finite element simulations were conducted to simulate the normal walking gait, and the stress distribution and displacement data of the femur and the implant model were obtained.Results: The peak von Mises stress of the femoral head and proximal femur in the partial replacement of the femoral head (PRFH) group were 22.8 MPa and 37.4 MPa, respectively, which were 3.1%–38.6% and 12.8%–37.4% lower than those of the other three surgical methods.Conclusion: The PRFH group exhibits better mechanical performance, reducing stress and displacement in the ONFH area, thus maintaining femoral head stability. Among the four hip-preserving approaches, from a biomechanical perspective, PRFH offers a new option for treating ONFH
Human cancer cells express Slug-based epithelial-mesenchymal transition gene expression signature obtained in vivo
Background: The biological mechanisms underlying cancer cell motility and invasiveness remain unclear, although it has been hypothesized that they involve some type of epithelial-mesenchymal transition (EMT). Methods: We used xenograft models of human cancer cells in immunocompromised mice, profiling the harvested tumors separately with species-specific probes and computationally analyzing the results. Results: Here we show that human cancer cells express in vivo a precise multi-cancer invasion-associated gene expression signature that prominently includes many EMT markers, among them the transcription factor Slug, fibronectin, and α-SMA. We found that human, but not mouse, cells express the signature and Slug is the only upregulated EMT-inducing transcription factor. The signature is also present in samples from many publicly available cancer gene expression datasets, suggesting that it is produced by the cancer cells themselves in multiple cancer types, including nonepithelial cancers such as neuroblastoma. Furthermore, we found that the presence of the signature in human xenografted cells was associated with a downregulation of adipocyte markers in the mouse tissue adjacent to the invasive tumor, suggesting that the signature is triggered by contextual microenvironmental interactions when the cancer cells encounter adipocytes, as previously reported. Conclusions: The known, precise and consistent gene composition of this cancer mesenchymal transition signature, particularly when combined with simultaneous analysis of the adjacent microenvironment, provides unique opportunities for shedding light on the underlying mechanisms of cancer invasiveness as well as identifying potential diagnostic markers and targets for metastasis-inhibiting therapeutics
Wafer-scale arrayed p-n junctions based on few-layer epitaxial GaTe
Two-dimensional (2D) materials have attracted substantial attention in
electronic and optoelectronic applications with superior advantages of being
flexible, transparent and highly tunable. Gapless graphene exhibits
ultra-broadband and fast photoresponse while the 2D semiconducting MoS2 and
GaTe unveil high sensitivity and tunable responsivity to visible light.
However, the device yield and the repeatability call for a further improvement
of the 2D materials to render large-scale uniformity. Here we report a
layer-by-layer growth of wafer-scale GaTe with a hole mobility of 28.4 cm2/Vs
by molecular beam epitaxy. The arrayed p-n junctions were developed by growing
few-layer GaTe directly on three-inch Si wafers. The resultant diodes reveal
good rectifying characteristics, photoresponse with a maximum photoresponsivity
of 2.74 A/W and a high photovoltaic external quantum efficiency up to 62%. The
photocurrent reaches saturation fast enough to capture a time constant of 22
{\mu}s and shows no sign of device degradation after 1.37 million cycles of
operation. Most strikingly, such high performance has been achieved across the
entire wafer, making the volume production of devices accessible. Finally,
several photo-images were acquired by the GaTe/Si photodiodes with a reasonable
contrast and spatial resolution, demonstrating for the first time the potential
of integrating the 2D materials with the silicon technology for novel
optoelectronic devices
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