We report the first results of a light weakly interacting massive particles (WIMPs) search from the CDEX-10 experiment with a 10 kg germanium detector array immersed in liquid nitrogen at the China ...Jinping Underground Laboratory with a physics data size of 102.8 kg day. At an analysis threshold of 160 eVee, improved limits of 8×10^{-42} and 3×10^{-36} cm^{2} at a 90% confidence level on spin-independent and spin-dependent WIMP-nucleon cross sections, respectively, at a WIMP mass (m_{χ}) of 5 GeV/c^{2} are achieved. The lower reach of m_{χ} is extended to 2 GeV/c^{2}.
A new strategy for creating functional trilayer nanofibers through triaxial electrospinning is demonstrated. Ethyl cellulose (EC) was used as the filament-forming matrix in the outer, middle, and ...inner working solutions and was combined with varied contents of the model active ingredient ketoprofen (KET) in the three fluids. Triaxial electrospinning was successfully carried out to generate medicated nanofibers. The resultant nanofibers had diameters of 0.74 ± 0.06 μm, linear morphologies, smooth surfaces, and clear trilayer nanostructures. The KET concentration in each layer gradually increased from the outer to the inner layer. In vitro dissolution tests demonstrated that the nanofibers could provide linear release of KET over 20 h. The protocol reported in this study thus provides a facile approach to creating functional nanofibers with sophisticated structural features.
Blastocystis ST4 is a common protistan parasite of the gastrointestinal tract of humans and a wide range of animals. While it has been suggested that colonization with ST4 is associated with healthy ...gut microbiota, how ST4 influences the gut microbiota remains poorly studied. This study aimed to examine the interactions between ST4 and several intestinal bacteria using in vitro co-culture systems, and to further investigate the mechanism of interaction and its effect on the epithelial barrier integrity of HT-29 cells.
Seven intestinal bacteria Bacteroides fragilis, Bifidobacterium longum, Bacillus subtilis, Bacteroides vulgatus, Escherichia coli, Enterococcus faecalis, and Lactobacillus brevis were co-cultured with Blastocystis ST4 in vitro. Flow cytometry and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) were used to determine the role of reactive oxygen species (ROS) and bacteria oxidoreductase genes, respectively, in response to Blastocystis co-incubation. Transepithelial electrical resistance (TEER) and flux assays were performed to assess the effect of microbiota representatives on the integrity of the intestinal epithelial barrier.
Co-incubation with Blastocystis ST4 showed a beneficial influence on most intestinal bacteria, while ST4 significantly inhibited the growth of B. vulgatus, a common pathogen in the genus Bacteroides. The decrease in B. vulgatus when co-incubated with Blastocystis ST4 was associated with high levels of ROS and the upregulation of oxidative stress-related genes. Furthermore, co-incubation with Blastocystis ST4 was able to protect the intestinal epithelial barrier from damage by B. vulgatus.
This study demonstrated, for the first time, that Blastocystis ST4 has beneficial effects on intestinal commensal bacteria in vitro, and can inhibit the growth of pathogenic B. vulgatus. Combined with previous microbiome research on ST4, our data suggest that ST4 may be a beneficial commensal.
Spin transfer torque magnetic tunnel junction (STT MTJ) is considered as a promising candidate for non-volatile memories thanks to its low power, high speed and easy integration with CMOS process. ...However, it has been demonstrated intrinsically stochastic. This phenomenon leads to the frequent occurrence of switching errors, which results in considerable reliability issues of hybrid CMOS/MTJ circuits. This paper proposes a compact model of MTJ with STT stochastic behavior, in which technical variations and temperature evaluation are properly integrated. Moreover, the phenomenon of dielectric breakdown of MgO barrier which determines the lifetime of MTJ is also taken into consideration. Its accurate performances allow a more realistic reliability analysis involving the influences of ambient environment and technical process.
The accurate prediction and manipulation of nanoscale product sizes is a major challenge in material processing. In this investigation, two process characteristics were explored during the modified ...coaxial electrospinning of zein, with the aim of understanding how this impacts the products formed. The characteristics studied were the spreading angle at the unstable region (
) and the length of the straight fluid jet (
). An electrospinnable zein core solution was prepared and processed with a sheath comprising ethanolic solutions of LiCl. The width of the zein nanoribbons formed (
) was found to be more closely correlated with the spreading angle and straight fluid jet length than with the experimental parameters (the electrolyte concentrations and conductivity of the shell fluids). Linear equations
= 546.44
- 666.04 and
= 2255.3
- 22.7 could be developed with correlation coefficients of
= 0.9845 and
= 0.9924, respectively. These highly linear relationships reveal that the process characteristics can be very useful tools for both predicting the quality of the electrospun products, and manipulating their sizes for functional applications. This arises because any changes in the experimental parameters would have an influence on both the process characteristics and the solid products' properties.
In this paper, we demonstrate experimentally a photodetector based on silicon-on-insulator substrate. The photosensing diode is formed in the substrate induced by the backgate bias instead of doping. ...TCAD simulation is conducted to confirm that the field-induced junction performs similarly as the doped p-n junction in terms of photodetection. A simplified process flow with low process temperature is developed to fabricate the device, which can save implantation step and reduce the cost. The photoresponses of the device under various biases, light intensities, and wavelengths are studied systematically with both experiment and TCAD simulation. Responsivity up to 1150 A/W is achieved experimentally. In addition, the response spectrum can be modulated by the back gate bias, which is a very attractive feature for multiband photodetection application. The field-induced photodiode in the substrate modulates the threshold voltage of the MOSFET at top Si layer as efficiently as the doped junction, confirmed by TCAD simulation.
We present X-ray timing results of the new black hole candidate MAXI J1535−571 during its 2017 outburst from Hard X-ray Modulation Telescope (Insight-HXMT) observations taken from 2017 September 6 to ...23. Following the definitions given by Belloni, we find that the source exhibits transitions from the low/hard state to the hard intermediate state, and eventually to the soft intermediate state. Quasi-periodic oscillations (QPOs) are found in the intermediate states, which suggest different types of QPOs. With the large effective area of Insight-HXMT at high energies, we are able to present the energy dependence of the QPO amplitude and centroid frequency up to 100 keV, which has rarely been explored by previous satellites. We also find that the phase lag at the type-C QPOs centroid frequency is negative (soft lag) and strongly correlated with the centroid frequency. Assuming a geometrical origin of type-C QPOs, the source is consistent with being a high-inclination system.
Blastocystis is a common protistan parasite inhabiting the gastrointestinal tract of humans and animals. While there are increasing reports characterizing the associations between Blastocystis and ...the gut microbiome in healthy individuals, only a few studies have investigated the relationships between Blastocystis and the gut microbiota in diarrheal patients. The effects of a specific subtype (ST7) of Blastocystis on the composition of gut microbiota in diarrheal patients were investigated using 16S ribosomal RNA (rRNA) gene sequencing and bioinformatic analyses. Compared with diarrheal patients without Blastocystis, diarrheal patients infected with Blastocystis ST7 exhibited lower bacterial diversity. Beta diversity analysis revealed significant differences in bacterial community structure between ST7-infected and Blastocystis-free patients. The proportion of Enterobacteriaceae and Escherichia-Shigella were significantly enriched in ST7-infected patients. In contrast, the abundance of Bacteroides and Parabacteroides were more prevalent in Blastocystis-free patients. The results of this study revealed, for the first time, that infection with Blastocystis ST7 is associated with lower bacterial diversity and altered microbial structure in diarrheal patients. Our study on clinical diarrheal patients is also the first to reinforce the notion that ST7 is a pathogenic subtype of Blastocystis.
DNA damage elicits a cellular signaling response that initiates cell cycle arrest and DNA repair. Here, we find that DNA damage triggers a critical block in glutamine metabolism, which is required ...for proper DNA damage responses. This block requires the mitochondrial SIRT4, which is induced by numerous genotoxic agents and represses the metabolism of glutamine into tricarboxylic acid cycle. SIRT4 loss leads to both increased glutamine-dependent proliferation and stress-induced genomic instability, resulting in tumorigenic phenotypes. Moreover, SIRT4 knockout mice spontaneously develop lung tumors. Our data uncover SIRT4 as an important component of the DNA damage response pathway that orchestrates a metabolic block in glutamine metabolism, cell cycle arrest, and tumor suppression.
► DNA damage induces SIRT4 and inhibits mitochondrial glutamine metabolism ► SIRT4 is required for proper repression of glutamine metabolism after DNA damage ► SIRT4 loss promotes genomic instability ► SIRT4 represses tumor growth, and SIRT4 knockout mice develop tumors with age
Abstract
We report on analysis of observations of the bright transient X-ray pulsar Swift J0243.6+6124 obtained during its 2017-2018 giant outburst with Insight-HXMT, NuSTAR, and Swift observatories. ...We focus on the discovery of a sharp state transition of the timing and spectral properties of the source at super-Eddington accretion rates, which we associate with the transition of the accretion disk to a radiation pressure dominated (RPD) state, the first ever directly observed for magnetized neutron star. This transition occurs at slightly higher luminosity compared to already reported transition of the source from sub- to super-critical accretion regime associate with onset of an accretion column. We argue that this scenario can only be realized for comparatively weakly magnetized neutron star, not dissimilar to other ultra-luminous X-ray pulsars (ULPs), which accrete at similar rates. Further evidence for this conclusion is provided by the non-detection of the transition to the propeller state in quiescence which strongly implies compact magnetosphere and thus rules out magnetar-like fields.
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