Measurement of the [Formula: see text]Ta([Formula: see text]) cross sections up to stellar s-process temperatures at the CSNS Back-n.

The neutron capture cross section of [Formula: see text]Ta is relevant to s-process of nuclear astrophysics, extraterrestrial samples analysis in planetary geology and new generation nuclear energy system design. The [Formula: see text]Ta([Formula: see text]) cross section had been measured between 1 eV and 800 keV at the back-streaming white neutron facility (Back-n) of China spallation neutron source(CSNS) using the time-of-flight (TOF) technique and [Formula: see text] liquid scintillator detectors. The experimental results are compared with the data of several evaluated libraries and previous experiments in the resolved and unresolved resonance region. Resonance parameters are extracted using the R-Matrix code SAMMY in the 1-700 eV region. The astrophysical Maxwell average cross section(MACS) from kT = 5 to 100 keV is calculated over a sufficiently wide range of neutron energies. For the characteristic thermal energy of an astrophysical site, at kT = 30keV the MACS value of [Formula: see text]Ta is 834 ± 75 mb, which shows an obvious discrepancy with the Karlsruhe Astrophysical Database of Nucleosynthesis in Stars (KADoNiS) recommended value 766 ± 15 mb. The new measurements strongly constrain the MACS of [Formula: see text]Ta([Formula: see text]) reaction in the stellar s-process temperatures.

Pathological characteristics and immune microenvironment of SMARCA4-deficient undifferentiated uterine sarcoma.

SMARCA4-deficient undifferentiated uterine sarcoma (SDUS) is a highly invasive single-gene malignant tumor caused by mutations in the SMARCA4 gene. SDUS has a poor prognosis, with no established treatment strategy at present. Further, there is a lack of relevant research on the role of the immune microenvironment in SDUS worldwide. Here, we report a case of SDUS that was diagnosed and analysed using morphological, immunohistochemical, and molecular detection techniques, along with the analysis of the immune microenvironment. By immunohistochemistry, the tumor cells showed retained INI-1 expression, focal CD10 expression, and loss of BRG1, CK-pan, synaptophysin, desmin, and ER expression. Further, some of the immune cells expressing CD3 and CD8 had infiltrated into the SDUS, but no PD-L1 expression was detected. The multiple immunofluorescent staining results showed that a proportion of the immune cells and SDUS cells expressed CD8/CD68/PD-1/PD-L1. Therefore, our report will help in the diagnostic awareness of SDUS.

KLF4-PFKFB3-driven glycolysis is essential for phenotypic switching of vascular smooth muscle cells.

Vascular smooth muscle cells (VSMCs) within atherosclerotic lesions undergo a phenotypic switching in a KLF4-dependent manner. Glycolysis plays important roles in transdifferentiation of somatic cells, however, it is unclear whether and how KLF4 mediates the link between glycolytic switch and VSMCs phenotypic transitions. Here, we show that KLF4 upregulation accompanies VSMCs phenotypic switching in atherosclerotic lesions. KLF4 enhances the metabolic switch to glycolysis through increasing PFKFB3 expression. Inhibiting glycolysis suppresses KLF4-induced VSMCs phenotypic switching, demonstrating that glycolytic shift is required for VSMCs phenotypic switching. Mechanistically, KLF4 upregulates expression of circCTDP1 and eEF1A2, both of which cooperatively promote PFKFB3 expression. TMAO induces glycolytic shift and VSMCs phenotypic switching by upregulating KLF4. Our study indicates that KLF4 mediates the link between glycolytic switch and VSMCs phenotypic transitions, suggesting that a previously unrecognized KLF4-eEF1A2/circCTDP1-PFKFB3 axis plays crucial roles in VSMCs phenotypic switching.

Timing Performance Simulation for 3D 4H-SiC Detector.

To meet the high radiation challenge for detectors in future high-energy physics, a novel 3D 4H-SiC detector was investigated. Three-dimensional 4H-SiC detectors could potentially operate in a harsh radiation and room-temperature environment because of its high thermal conductivity and high atomic displacement threshold energy. Its 3D structure, which decouples the thickness and the distance between electrodes, further improves the timing performance and the radiation hardness of the detector. We developed a simulation software-RASER (RAdiation SEmiconductoR)-to simulate the time resolution of planar and 3D 4H-SiC detectors with different parameters and structures, and the reliability of the software was verified by comparing the simulated and measured time-resolution results of the same detector. The rough time resolution of the 3D 4H-SiC detector was estimated, and the simulation parameters could be used as guideline to 3D 4H-SiC detector design and optimization.

A simple method for measuring electron drift velocity in gases using grid ionization chamber.

A simple method for measuring the electron drift velocity in gases with a given electric field using a grid ionization chamber is proposed and demonstrated. By collimating incident α particles that are perpendicular to the electric field, the drift velocity can be derived easily using the electron drift distance from primary ionization to a grid divided by the time interval between the cathode and anode signal starting times. These experimental settings can avoid additional signal processing of signals and reduce the effect of electron diffusion. Using this method, the measurement of electron drift velocities in 90% Ar + 10% CO2 is presented. Measured results agree well with the simulated values and with existing experimental results.

Melanocytes derived from mouse hair follicles: A novel study model to assess pigmentation disorders.

Melanocytes are the major cells responsible for skin and fair pigmentation in vertebrates. They localize to hair follicles(HFs) and the epidermis during embryonic development. A reduced number or dysfunction of melanocytes results in pigmentation disorders.Thus, methods for isolation, culture, and identification of melanocytes in mouse hair follicles provide an experimental basis for thestudy of of pigmentation disorders. In the current work, we harvested the melanocytes from the anagen phase dorsal skin of C57BL/6 mice.After its separation from the skin, the dermis was digested, and the HFs were released. HFs were then also digested, and the cells released from HFs were cultured in melanocyte growth medium. Immunofluorescence and immunohistochemistry staining were used to localize the distribution of melanocytes in HFs . Reverse transcription polymerase chain reaction was performed to detect the expression of specific melanocyte marker genes. Immunofluorescence, immunohistochemistry, flow cytometry, and western blot were carried out to detect the expression of marker proteins in cells. 3,4-Dihydroxy-L-phenylalanine (L-DOPA) staining was used to detect the pigmentation functionality of melaonocytes. Based on our results, we conclude that mature and functional melanocytes can be successfully obtained from theHFs, providing a cell model to study pigmentation disorders. The current findings provide novel insights for the treatment of pigmentation disorders by autologous cell transplantation. Further, we believe that issues related to skin damage, insufficient numbers of autologous cells, and autoimmune problems can be resolved in future though the use of functional melanocytes.

Fluorescent labelling in living dental pulp stem cells by graphene oxide quantum dots.

Cellular labelling is possible to offer significant information after transplantation for the purpose of determining stem cell therapy's efficacy. According to the research, it has been reported that graphene oxide quantum dots (GOQDs) are a kind of healthy biological labelling agent for stem cells which show little cytotoxicity. GOQDs' interactions have been examined on the dental pulp stem cells (hDPSCs) of human beings for the purpose of investigating GOQD's biocompatibility and uptake and explored GOQDs' effects on hDPSCs' metabolic activity and the proliferation. According to the outcomes, GDQDs have been accepted by hDPSCs in a time-dependent and concentration-dependent behaviour. Moreover, no important changes have been discovered within hDOPSCs' proliferation, viability as well as metabolic activity after treatment with GOQDs. Therefore, such resources have shown that GOQDs can be multifunctional agents for cell therapy, drug delivery as well as cell imaging and also as outstanding candidates for labelling stem cells.

Divergent scaling of respiration rates to nitrogen and phosphorus across four woody seedlings between different growing seasons.

Empirical studies indicate that the exponents governing the scaling of plant respiration rates (R) with respect to biomass (M) numerically vary between three-fourth for adult plants and 1.0 for seedlings and saplings and are affected by nitrogen (N) and phosphorus (P) content. However, whether the scaling of R with respect to M (or N and P) varies among different phylogenetic groups (e.g., gymnosperms vs. angiosperms) or during the growing and dormant seasons remains unclear. We measured the whole-plant R and M, and N and P content of the seedlings of four woody species during the growing season (early October) and the dormant season (January). The data show that (i) the scaling exponents of R versus M, R versus N, and R versus P differed significantly among the four species, but (ii), not between the growing and dormant seasons for each of the four species, although (iii) the normalization constants governing the scaling relationships were numerically greater for the growing season compared to the dormant season. In addition, (iv) the scaling exponents of R versus M, R versus N, and R versus P were numerically larger for the two angiosperm species compared to those of the two gymnosperm species, (v) the interspecific scaling exponents for the four species were greater during the growing season than in the dormant season, and (vi), interspecifically, P scaled nearly isometric with N content. Those findings indicate that the metabolic scaling relationships among R, M, N, and P manifest seasonal variation and differ between angiosperm and gymnosperm species, that is, there is no single, canonical scaling exponent for the seedlings of woody species.

"Diminishing returns" in the scaling of leaf area vs. dry mass in Wuyi Mountain bamboos, Southeast China.

PREMISE OF STUDY: Leaf area and dry mass are crucial for plant metabolic performance. The "diminishing returns" hypothesis predicts that leaf area will scale less than one with respect to leaf dry mass, indicating that the cost of light interception increases with leaf area. However, it remains unclear whether and how this scaling relationship varies among species growing in different environments. METHODS: More than 2000 measurements from five bamboo species adapted to high and low light and growing at different elevations in Wuyi Mountains, Southeast China, were used to explore how the leaf area vs. dry mass scaling relationship was affected by light and elevation. KEY RESULTS: The data indicate that (1) the normalization constants for leaf area vs. dry mass were positively but not significantly correlated with increasing leaf size and that (2) the scaling exponents remained numerically invariant among all five bamboo species, with a common slope of 0.85. Standardized major axis (SMA) analyses and comparisons of 95% confidence intervals also showed that the numerical values of the scaling exponents did not differ regardless of elevation and were similar between shaded and unshaded adapted species, whereas the numerical values of the normalization constants increased with decreasing light. CONCLUSIONS: The data collected for all five bamboo species are consistent with the "diminishing returns" hypothesis, i.e., the scaling exponents governing the leaf area vs. dry mass scaling relationship are less than one within and across species and are insensitive to light conditions or elevation.

Scaling relationships of twig biomass allocation in Pinus hwangshanensis along an altitudinal gradient.

Understanding the response of biomass allocation in twigs (the terminal branches of current-year shoots) to environmental change is crucial for elucidating forest ecosystem carbon storage, carbon cycling, and plant life history strategies under a changing climate. On the basis of interspecies investigations of broad-leaved plants, previous studies have demonstrated that plants respond to environmental factors by allocating biomass in an allometric manner between support tissues (i.e., stems) and the leaf biomass of twigs, where the scaling exponent (i.e., slope of a log-log linear relationship, α) is constant, and the scaling constant (i.e., intercept of a log-log linear relationship, log ß) varies with respect to environmental factors. However, little is known about whether the isometric scaling exponents of such biomass allocations remain invariant for single species, particularly conifers, at different altitudes and in different growing periods. In this study, we investigated how twig biomass allocation varies with elevation and period among Pinus hwangshanensis Hsia trees growing in the mountains of Southeast China. Specifically, we explored how twig stem mass, needle mass, and needle area varied throughout the growing period (early, mid-, late) and at three elevations in the Wuyi Mountains. Standardized major axis analysis was used to compare the scaling exponents and scaling constants between the biomass allocations of within-twig components. Scaling relationships between these traits differed with growing period and altitude gradient. During the different growing periods, there was an isometric scaling relationship, with a common slope of 1.0 (i.e., α ≈ 1.0), between needle mass and twig mass (the sum of the total needle mass and the stem mass), whereas there were allometric scaling relationships between the stem mass and twig mass and between the needle mass and stem mass of P. hwangshanensis. The scaling constants (log ß) for needle mass vs. twig mass and for needle mass vs. stem mass increased progressively across the growing stages, whereas the scaling constants of stem mass vs. twig mass showed the opposite pattern. The scaling exponents (α) of needle area with respect to needle biomass increased significantly with growing period, changing from an allometric relationship (i.e., α < 1.0) during the early growing period to a nearly isometric relationship (i.e., α ≈ 1.0) during the late growing period. This change possibly reflects the functional adaptation of twigs in different growing periods to meet their specific reproductive or survival needs. At different points along the altitudinal gradient, the relationships among needle mass, twig mass, and stem mass were all isometric (i.e., α ≈ 1.0). Moreover, significant differences were found in scaling constants (log ß) along the altitudinal gradient, such that species had a smaller stem biomass but a relatively larger needle mass at low altitude. In addition, the scaling exponents remained numerically invariant among all three altitudes, with a common slope of 0.8, suggesting that needle area failed to keep pace with the increasing needle mass at different altitudes. Our results indicated that the twig biomass allocation pattern was significantly influenced by altitude and growing period, which reflects the functional adaptation of twigs to meet their specific survival needs under different climatic conditions.

Aligned Fibers Fabricated by Near-Field Electrospinning Influence the Orientation and Differentiation of hPDLSCs for Periodontal Regeneration.

The periodontal ligament (PDL) is a specific connective tissue composed of organized and aligned collagenous fibers that fix the tooth root in the alveolar bone. The alignment of PDL fibers and their function have been neglected in the past, as many studies investigated the regeneration of the periodontium, including alveolar bone and cementum regeneration. In this study, we fabricated biodegradable aligned fibers (ε-caprolactone/collagen) by near-field electrospinning (NFE) to control the arrangement of human periodontal ligament stem cells (hPDLSCs), aiming to guide the oriented regeneration of the periodontal ligament. Compared with random electrospun fibers, the in vitro study investigated the effects of nanotopography on stem cell differentiation of hPDLSCs. The hPDLSCs were identified by flow cytometry, and the multipotency of hPDLSCs was confirmed by successful osteogenic induction. The hPDLSCs were co-cultured with aligned and random fibers. The cell morphology was observed by confocal micrograph and scanning electron micrograph, which showed that aligned fibers could guide the orientation and elongation of hPDLSCs. The expression of periodontal ligament-related genes was higher when cultured with aligned fibers than when cultured with random fibers. In conclusion, via near-field electrospinning, aligned biodegradable fibers were prepared and guided the orientation arrangement of hPDLSCs, providing a better microenvironment for periodontal ligament regeneration. This technology might be further used in the regeneration of tissues in a given direction.

[The X-Ray Fluorescence Spectrometer Based on Pyroelectric Effect].

Pyroelectric X-ray generator is implemented, and an X-ray fluorescence spectrometer is accomplished by combining the pyroelectric X-ray generator with a high energy resolution silicon drift detector. Firstly, the parameters of the X-ray generator are decided by analyzing and calculating the influence of the thickness of the pyroelectriccrystal and the thickness of the target on emitted X-ray. Secondly, the emitted X-ray is measured. The energy of emitted X-ray is from 1 to 27 keV, containing the characteristic X-ray of Cu and Ta, and the max counting rate is more than 3 000 per second. The measurement also proves that the detector of the spectrometer has a high energy resolution which the FWMH is 210 eV at 8. 05 keV. Lastly, samples of Fe, Ti, Cr and high-Ti basalt are analyzed using the spectrometer, and the results are agreed with the elements of the samples. It shows that the spectrometer consisting of a pyroelectric X-ray generator and a silicon drift detector is effective for element analysis. Additionally, because each part of the spectrometer has a small volume, it can be easily modified to a portable one which is suitable for non-destructive, on-site and quick element analysis.

Feasibility of human hair follicle-derived mesenchymal stem cells/CultiSpher(®)-G constructs in regenerative medicine.

The use of human mesenchymal stem cells (hMSCs) in cell therapies has increased the demand for strategies that allow efficient cell scale-up. Preliminary data on the three-dimensional (3D) spinner culture describing the potential use of microcarriers for hMSCs culture scale-up have been reported. We exploited a rich source of autologous stem cells (human hair follicle) and demonstrated the robust in vitro long-term expansion of human hair follicle-derived mesenchymal stem cells (hHF-MSCs) by using CultiSpher(®)-G microcarriers. We analyzed the feasibility of 3D culture by using hHF-MSCs/CultiSpher(®)-G microcarrier constructs for its potential applicability in regenerative medicine by comparatively analyzing the performance of hHF-MSCs adhered to the CultiSpher(®)-G microspheres in 3D spinner culture and those grown on the gelatin-coated plastic dishes (2D culture), using various assays. We showed that the hHF-MSCs seeded at various densities quickly adhered to and proliferated well on the microspheres, thus generating at least hundreds of millions of hHF-MSCs on 1 g of CultiSpher(®)-G within 12 days. This resulted in a cumulative cell expansion of greater than 26-fold. Notably, the maximum and average proliferation rates in 3D culture were significantly greater than that of the 2D culture. However, the hHF-MSCs from both the cultures retained surface marker and nestin expression, proliferation capacity and differentiation potentials toward adipocytes, osteoblasts and smooth muscle cells and showed no significant differences as evidenced by Edu incorporation, cell cycle, colony formation, apoptosis, biochemical quantification and qPCR assays.

Large-scale expansion of Wharton's jelly-derived mesenchymal stem cells on gelatin microbeads, with retention of self-renewal and multipotency characteristics and the capacity for enhancing skin wound healing.

INTRODUCTION: Successful stem cell therapy relies on large-scale generation of stem cells and their maintenance in a proliferative multipotent state. This study aimed to establish a three-dimension culture system for large-scale generation of hWJ-MSC and investigated the self-renewal activity, genomic stability and multi-lineage differentiation potential of such hWJ-MSC in enhancing skin wound healing. METHODS: hWJ-MSC were seeded on gelatin microbeads and cultured in spinning bottles (3D). Cell proliferation, karyotype analysis, surface marker expression, multipotent differentiation (adipogenic, chondrogenic, and osteogenic potentials), and expression of core transcription factors (OCT4, SOX2, NANOG, and C-MYC), as well as their efficacy in accelerating skin wound healing, were investigated and compared with those of hWJ-MSC derived from plate cultres (2D), using in vivo and in vitro experiments. RESULTS: hWJ-MSC attached to and proliferated on gelatin microbeads in 3D cultures reaching a maximum of 1.1-1.30×10(7) cells on 0.5 g of microbeads by days 8-14; in contrast, hWJ-MSC derived from 2D cultures reached a maximum of 6.5 -11.5×10(5) cells per well in a 24-well plate by days 6-10. hWJ-MSC derived by 3D culture incorporated significantly more EdU (P<0.05) and had a significantly higher proliferation index (P<0.05) than those derived from 2D culture. Immunofluorescence staining, real-time PCR, flow cytometry analysis, and multipotency assays showed that hWJ-MSC derived from 3D culture retained MSC surface markers and multipotency potential similar to 2D culture-derived cells. 3D culture-derived hWJ-MSC also retained the expression of core transcription factors at levels comparable to their 2D culture counterparts. Direct injection of hWJ-MSC derived from 3D or 2D cultures into animals exhibited similar efficacy in enhancing skin wound healing. CONCLUSIONS: Thus, hWJ-MSC can be expanded markedly in gelatin microbeads, while retaining MSC surface marker expression, multipotent differential potential, and expression of core transcription factors. These cells also efficiently enhanced skin wound healing in vivo, in a manner comparable to that of hWJ-MSC obtained from 2D culture.

Cyclosporine A increases hair follicle growth by suppressing apoptosis-inducing factor nuclear translocation: a new mechanism.

Cyclosporine A (CsA) enhances hair growth through caspase-dependent pathways by retarding anagen-to-catagen phase transition in the hair follicle growth cycle. Whether apoptosis-inducing factor (AIF), a protein that induces caspase-independent apoptosis, can regulate the hair follicle cycle in response to CsA is currently unclear. Here, we show that the pro-hair growth properties of CsA are in part due to blockage of AIF nuclear translocation. We first isolate hair follicles from murine dorsal skin. We then used Western blot, immunohistochemistry and immunofluorescence to evaluate the expression and localization of AIF in hair follicles. We also determined whether modulation of AIF was responsible for the effects of CsA at the anagen-to-catagen transition. AIF was expressed in hair follicles during the anagen, catagen and telogen phases. There was significant nuclear translocation of AIF as hair follicles transitioned from anagen to late catagen phase; this was inhibited by CsA, likely due to reduced cyclophilin A expression and attenuated AIF release from mitochondria. However, we note that AIF translocation was not completely eliminated, which likely explains why the transition to catagen phase was severely retarded by CsA, rather than being completely inhibited. We speculate that blockade of the AIF signalling pathway is a critical event required for CsA-dependent promotion of hair growth in mice. The study of AIF-related signalling pathways may provide insight into hair diseases and suggest potential novel therapeutic strategies.

[Near infrared distance sensing method for Chang'e-3 alpha particle X-ray spectrometer].

Alpha particle X-ray spectrometer (APXS) is one of the payloads of Chang'E-3 lunar rover, the scientific objective of which is in-situ observation and off-line analysis of lunar regolith and rock. Distance measurement is one of the important functions for APXS to perform effective detection on the moon. The present paper will first give a brief introduction to APXS, and then analyze the specific requirements and constraints to realize distance measurement, at last present a new near infrared distance sensing algorithm by using the inflection point of response curve. The theoretical analysis and the experiment results verify the feasibility of this algorithm. Although the theoretical analysis shows that this method is not sensitive to the operating temperature and reflectance of the lunar surface, the solar infrared radiant intensity may make photosensor saturation. The solutions are reducing the gain of device and avoiding direct exposure to sun light.

[Temperature effect correction for Chang'E-3 alpha particle X-ray spectrometer].

Alpha particle X-ray spectrometer (APXS) is one of the payloads of Chang'E-3 lunar rover of China's Lunar Exploration Project. The present paper introduces briefly the components of APXS, how it works and its working environment on the lunar surface. The environmental temperature effect has been studied with simulations and experiments, and the results show that the temperature of the APXS sensor will be varying during the measuring on the lunar surface. And another experiment reveals that the energy resolution becomes worse if the sensor's temperature is varying. In this paper, a correction method based on Pearson's chi-squared test is presented. The method can improve the energy resolution when the sensor's temperature is varying. We have tested the method with the spectra acquired by APXS in the temperature varying period of Temperature Cycling Test, and the results show that the method is efficient and reliable.