Growth of single-walled carbon nanotubes from well-defined POSS nanoclusters structure

High-quality single-walled carbon nanotubes (SWNTs) with narrow diameter distribution can be generated from well-defined Si8O12 nanoclusters structure which form from thermal decomposition of chemically modified polyhedral oligomeric silsesquioxane (POSS). The nanosized SixOy particles were proved to be responsible for the SWNT growth and believed to be the reason for the narrow diameter distribution of the as-grown SWNTs. This could be extended to other POSS. The SWNTs grown from the nanosized SixOy particles were found to be semiconducting enriched SWNTs (s-SWNTs). A facile patterning technology, direct photolithography, was developed for generating SWNT pattern, which is compatible to industrial-level fabrication of SWNTs pattern for device applications. The metal-free growth together with preferential growth of s-SWNTs and patterning in large scale from the structure-defined silicon oxide nanoclusters not only represent a big step toward the control growth of SWNTs and fabrication of devices for applications particularly in nanoelectronics and biomedicine but also provide a system for further studying and understanding the growth mechanism of SWNTs from nanosized materials and the relationship between the structure of SWNT and nonmetal catalysts

Relationship of body mass index and visceral fat area combination with arterial stiffness and cardiovascular risk in cardiovascular disease-free people: NHANES (2011–2018)

Background: Obesity and arterial stiffness are strongly associated with car diovascular disease; however, their relationship remains controversial. Methods: Body mass index was measured using anthropometric evaluation, and visceral fat area was calculated using an absorptiometry scan. Results: The data of 5309 participants were collected from NHANES (National Health and Nutrition Examination Survey) (2011–2018). Based on the normal-weight normal visceral fat group that was considered as a reference, ePWV increased in all other groups, with the obese grade 2 visceral obesity group increasing the most by 26.35 cm/s (95% CI: 13.52, 39.18, P < 0.001), followed by normal-weight visceral obesity group 24.43 cm/s (95% CI: 1.88, 46.98, P = 0.035), which was even higher than obese grade 1 visceral obesity (β: 21.16, 95% CI: 9.24, 33.07, P = 0.001), obese grade 2 normal visceral fat group (β: 13.8; 95% CI: 0.10, 27.5, P = 0.048) and overweight visceral obesity group (β: 10.23; 95% CI: 1.89, 18.57, P = 0.018). For the 10-year cardiovascular risk, the obese grade 2 visceral obesity group had a 9.56-fold increase in compared with the control (OR: 10.56, 95% CI: 4.06, 27.51, P < 0.0001). Normal-weight visceral obesity, obese grade 1 visceral obesity, and overweight visceral obesity groups increased by 8.03-fold (OR: 9.03, 95% CI: 2.66, 30.69; P < 0.001), 7.91-fold (OR: 8.91, 95% CI: 3.82, 20.79, P < 0.001), and 7.28-fold (OR: 8.28, 95% CI: 3.19, 21.46, P < 0.001). The risk was lower in the normal visceral fat group. Except for the obese grade 2 normal visceral fat group, there was no significant difference in other groups. Conclusions: Normal-weight visceral obesity was associated with higher arterial stiffness and 10-year cardiovascular risk

Gulp1 controls Eph/ephrin trogocytosis and is important for cell rearrangements during development

Trogocytosis, in which cells nibble away parts of neighboring cells, is an intercellular cannibalism process conserved from protozoa to mammals. Its underlying molecular mechanisms are not well understood and are likely distinct from phagocytosis, a process that clears entire cells. Bi-directional contact repulsion induced by Eph/ephrin signaling involves transfer of membrane patches and full-length Eph/ephrin protein complexes between opposing cells, resembling trogocytosis. Here, we show that the phagocytic adaptor protein Gulp1 regulates EphB/ephrinB trogocytosis to achieve efficient cell rearrangements of cultured cells and during embryonic development. Gulp1 mediates trogocytosis bi-directionally by dynamic engagement with EphB/ephrinB protein clusters in cooperation with the Rac-specific guanine nucleotide exchange factor Tiam2. Ultimately, Gulp1's presence at the Eph/ephrin cluster is a prerequisite for recruiting the endocytic GTPase dynamin. These results suggest that EphB/ephrinB trogocytosis, unlike other trogocytosis events, uses a phagocytosis-like mechanism to achieve efficient membrane scission and engulfment

B7H3 ameliorates LPS-induced acute lung injury via attenuation of neutrophil migration and infiltration

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are characterized by an excessive inflammatory response within the lungs and severely impaired gas exchange resulting from alveolar-capillary barrier disruption and pulmonary edema. The costimulatory protein B7H3 functions as both a costimulator and coinhibitor to regulate the adaptive and innate immune response, thus participating in the development of microbial sepsis and pneumococcal meningitis. However, it is unclear whether B7H3 exerts a beneficial or detrimental role during ALI. In the present study we examined the impact of B7H3 on pulmonary inflammatory response, polymorphonuclear neutrophil (PMN) influx, and lung tissue damage in a murine model of lipopolysaccharide (LPS)-induced direct ALI. Treatment with B7H3 protected mice against LPS-induced ALI, with significantly attenuated pulmonary PMN infiltration, decreased lung myeloperoxidase (MPO) activity, reduced bronchoalveolar lavage fluid (BALF) protein content, and ameliorated lung pathological changes. In addition, B7H3 significantly diminished LPS-stimulated PMN chemoattractant CXCL2 production by inhibiting NF-kappa B p65 phosphorylation, and substantially attenuated LPS-induced PMN chemotaxis and transendothelial migration by down-regulating CXCR2 and Mac-1 expression. These results demonstrate that B7H3 substantially ameliorates LPS-induced ALI and this protection afforded by B7H3 is predominantly associated with its inhibitory effect on pulmonary PMN migration and infiltration

The variation changes of the precipitation – runoff relationship

The variation of the rainfall-runoff relationship t will lead to the disappearance of the consistency assumption of engineering hydrology, which will influence the planning, design, operation management and development and utilization of water resources. Therefore, the variation diagnosis of the rainfall -runoff relationship has become one of the hot topics and key issues in this area. In this study, the variation points of the precipitation-runoff relationship are defined, the difference between the variation point and the mutation point is distinguished, and the method of variation classification is proposed based on the the dimensionless mean and variation coefficients. Then, a comprehensive diagnosis system of the rainfall-runoff relationship variation is constructed on the basis of systematically summarying and analyzing of the diagnosis method of rainfall - runoff relationship variation at home and abroad. Taking the Weihe River Basin as a case study, the comprehensive diagnosis system is verified by applying it to test the change point the annual runoff time series at the Huaxian hydrological station. And the results show that the comprehensive diagnosis method proposed in this paper is scientific and reasonable

The performance of large-pitch AC-LGAD with different N+ dose

AC-Coupled LGAD (AC-LGAD) is a new 4D detector developed based on the Low Gain Avalanche Diode (LGAD) technology, which can accurately measure the time and spatial information of particles. Institute of High Energy Physics (IHEP) designed a large-size AC-LGAD with a pitch of 2000 {\mu}m and AC pad of 1000 {\mu}m, and explored the effect of N+ layer dose on the spatial resolution and time resolution. The spatial resolution varied from 32.7 {\mu}m to 15.1 {\mu}m depending on N+ dose. The time resolution does not change significantly at different N+ doses, which is about 15-17 ps. AC-LGAD with a low N+ dose has a large attenuation factor and better spatial resolution. Large signal attenuation factor and low noise level are beneficial to improve the spatial resolution of the AC-LGAD sensor

Characterization of the response of IHEP-IME LGAD with shallow carbon to Gamma Irradiation

Low Gain Avalanche Detectors (LGAD), as part of High-Granularity Timing Detector (HGTD), is crucial to reducing pileup in the upgrading to HL-LHC. Many studies have been done on the bulk damages of the LGAD. However, there's no study about the surface radiation hardness of the LGAD sensors with carbon implanted. The IHEP-IME LGAD version 3 with the shallow carbon and different interpad separations were irradiated up to 2 MGy by gamma irradiation. The performance of the IHEP-IME LGAD version 3 before and after irradiation had been tested, such as the leakage current, break-down voltage, capacitance, V$_{gl}$, and inter-pad resistance. The results showed that apart from minor fluctuations in some samples, no significant changes concerning inter-pad separation were observed before and after irradiation. Leakage current and break-down voltage increase after irradiation, which is considered due to surface passivation; the overall inter-pad resistance are larger than $10^9\ \Omega$before and after irradiation; capacitance is found to be less than 4.5 pF with a slight drop in V$_{gl}$ after irradiation. All parameters meet the requirements of HGTD, and the results indicated that IHEP-IME LGAD v3 has excellent anti-irradiation performance

Characterisation of Spatial and Timing Resolution of IHEP AC-LGAD Strip

AC-coupled LGAD(AC-LGAD) Strip is a new design of LGAD that allows high-precision detection of particle spatiotemporal information whereas reducing the density of readout electronics. For AC-LGAD Strips, there is limited research on the impact of different strip pitches on the spatiotemporal detection performance at the small amount of injected charge. The Institute of High Energy Physics has designed an AC-LGAD Strip prototype with pitches of 150 $\mu m$, 200 $\mu m$, and 250 $\mu m$. The spatial and timing resolutions of the prototype are studied through the laser Transient Current Technique (TCT) scan with different amounts of injected charge. The results show that both the spatial and timing resolution improves as the strip pitch decreases. Increases in both temporal and spatial resolutions as the amount of charge injected increases are observed. The spatial and timing resolution is better than 60 ps and 40 $\mu m$ at 1 Minimum Ionizing Particle (MIP), and better than 10 ps and 5 $\mu m$ at 40 MIPs. Increasing Signal-to-Noise Ratio (SNR) is the key to improving spatial and temporal resolution, whereas increasing the signal attenuation rate by reducing the gap between adjacent electrodes also helps to improve spatial resolution. The enhancements of spatial and timing resolutions by both SNR and signal attenuation rate decrease with increasing amount of MIP. This study can help design and optimize the AC-LGAD Strip detectors and readout electronics