We present the improved constraints on couplings of solar axions and more generic bosonic dark matter particles using 737.1 kg days of data from the CDEX-1B experiment. The CDEX-1B experiment, ...located at the China Jinping Underground Laboratory, primarily aims at the direct detection of weakly interacting massive particles using a p-type point-contact germanium detector. We adopt the profile likelihood ratio method for analysis of data in the presence of backgrounds. An energy threshold of 160 eV was achieved, much better than the 475 eV of CDEX-1A with an exposure of 335.6 kg days. This significantly improves the sensitivity for the bosonic dark matter below 0.8 keV among germanium detectors. Limits are also placed on the coupling gAe < 2.48 × 10−11 from Compton, bremsstrahlung, atomic-recombination, and deexcitation channels and geffAN × gAe < 4.14 × 10−17 from a 57Fe M1 transition at 90% confidence level.
Selective methane oxidation is difficult chemistry. Here we describe a strategy for the electrocatalysis of selective methane oxidation by immobilizing tricopper catalysts on the cathodic surface. In ...the presence of dioxygen and methane, the activation of these catalysts above a threshold cathodic potential can initiate the dioxygen chemistry for O atom transfer to methane. The catalytic turnover is completed by facile electron injections into the tricopper catalysts from the electrode. This technology leads to dramatic enhancements in performance of the catalysts toward methane oxidation. Unprecedented turnover frequencies (>40 min–1) and high product throughputs (turnover numbers >30 000 in 12 h) are achieved for this challenging chemical transformation in water under ambient conditions. The technology is green and suitable for on-site direct conversion of methane into methanol.
Based on our previous work on the clinical activity of cetuximab in recurrent nasopharyngeal carcinoma (NPC), we evaluated the feasibility of adding cetuximab to concurrent cisplatin and ...intensity-modulated radiotherapy (IMRT) in locoregionally advanced NPC.
Patients with American Joint Committee on Cancer stage III–IVB NPC were given an initial dose of cetuximab (400 mg/m2) 7–10 days before receiving concurrent IMRT, weekly cisplatin (30 mg/m2/week) and cetuximab (250 mg/m2/week).
Thirty patients (median age of 45 years) with stage III (67%), IVA (30%) and IVB (3%) nonkeratinizing NPC were enrolled. Grade 3–4 oropharyngeal mucositis occurred in 26 (87%) patients and 10 (33%) patients required short-term nasogastric feeding. Grade 3 radiotherapy-related dermatitis occurred in six patients (20%) and three patients (10%) had grade 3 cetuximab-related acneiform rash. These grade 3–4 skin and mucosal toxic effects were manageable and reversible. At a median follow-up of 31.8 months 95% confidence interval (CI) 26.2–32.1 months, the 2-year progression-free survival was 86.5% (95% CI 74.3% to 98.8%).
Concurrent administration of cetuximab, weekly cisplatin and IMRT is a feasible strategy against locoregionally advanced NPC. Preliminary survival data compare favorably with historic data and further follow-up is warranted.
Aircraft carbon fiber/epoxy composite material is sensitive to lightning strike. Its damage assessment and protection design suffered from lightning strike is becoming increasingly important. Four ...different types of carbon fiber/epoxy composite laminates are selected, which are without protection, with full spraying aluminum coating, with local spraying aluminum coating and with spraying aluminum coating on glass cloth pasted to fastener head, respectively. Impulse electrical current tests were performed by implementing electrical current waveforms with different peak values with regard to different lightning zonings. Three-dimensional finite element models of composite laminate and its protection structures are accurately built to assess lightning ablation characteristics based on the coupled thermal/electrical/structural analysis and element deletion method, in which different electrical and thermal physical properties of the elements are defined depending on different temperature conditions. The results show that simulation results are good agreement with experimental results. Fiber damaged area, the damaged area and the maximum damaged thickness increases with the increase of electrical current peak. Aluminum coating has a good effect on anti-lightning strike. The thicker aluminum layer and the better to anti-lightning strike.
Six tricopper cluster complexes of the type CuICuICuI(L)1+ supported by a series of multidentate ligands (L) have been developed as oxidation catalysts. These complexes are capable of mediating the ...facile oxygen‐atom transfer to hydrocarbon substrates like cyclohexane, benzene, and styrene (C6H12, C6H6 and C8H8) upon activation by hydrogen peroxide at room temperature. The processes are catalytic with high turnover frequencies (TOF), efficiently oxidizing the substrates to their corresponding alcohols, aldehydes, and ketones in moderate to high yields. The catalysts are robust with turnover numbers (TON) limited only by the availability of hydrogen peroxide used to drive the catalytic turnover. The TON is independent of the substrate concentration and the TOF depends linearly on the hydrogen peroxide concentration when the oxidation of the substrate mediated by the activated tricopper complex is rapid. At low substrate concentrations, the catalytic system exhibits abortive cycling resulting from competing reduction of the activated catalyst by hydrogen peroxide. This behaviour of the system is consistent with activation of the tricopper complex by hydrogen peroxide to generate a strong oxidizing intermediate capable of a facile direct “oxygen‐atom” transfer to the substrate upon formation of a transient complex between the activated catalyst and the substrate. Some substrate specificity has also been noted by varying the ligand design. These properties of the tricopper catalyst are characteristic of many enzyme systems, such as cytochrome P450, which participate in biological oxidations.
Diverse entry inhibitors targeting the gp120 subunit of the HIV-1 envelope (Env) trimer have been developed including BMS-626529, also called temsavir, a prodrug version of which is currently in ...phase III clinical trials. Here we report the characterization of a panel of small-molecule inhibitors including BMS-818251, which we show to be >10-fold more potent than temsavir on a cross-clade panel of 208-HIV-1 strains, as well as the engineering of a crystal lattice to enable structure determination of the interaction between these inhibitors and the HIV-1 Env trimer at higher resolution. By altering crystallization lattice chaperones, we identify a lattice with both improved diffraction and robust co-crystallization of HIV-1 Env trimers from different clades complexed to entry inhibitors with a range of binding affinities. The improved diffraction reveals BMS-818251 to utilize functional groups that interact with gp120 residues from the conserved β20-β21 hairpin to improve potency.
We present improved germanium-based constraints on sub-GeV dark matter via dark matter-electron (χ-e) scattering using the 205.4 kg·day dataset from the CDEX-10 experiment. Using a novel calculation ...technique, we attain predicted χ-e scattering spectra observable in high-purity germanium detectors. In the heavy mediator scenario, our results achieve 3 orders of magnitude of improvement for m_{χ} larger than 80 MeV/c^{2} compared to previous germanium-based χ-e results. We also present the most stringent χ-e cross-section limit to date among experiments using solid-state detectors for m_{χ} larger than 90 MeV/c^{2} with heavy mediators and m_{χ} larger than 100 MeV/c^{2} with electric dipole coupling. The result proves the feasibility and demonstrates the vast potential of a new χ-e detection method with high-purity germanium detectors in ultralow radioactive background.
In this paper we report the growth of high quality SnS thin films with good crystallinity deposited on two-dimensional (2D) mica substrates. It is believed that the 2D nature of SnS, with strong ...intra-layer covalent bonds and weak inter-layer van der Waals interactions, is responsible for its relative insensitivity to lattice mismatch. We also investigated the reduction of Sn vacancies in the material using Sn-compensation technique during the material growth process. The experimental results clearly demonstrated substantial enhancements in the electrical and structural properties for films deposited using Sn-compensation technique. A mobility of 51 cm
V
s
and an XRD rocking curve full width at half maximum of 0.07° were obtained. Sn-compensated SnS/GaN:Si heterojunctions were fabricated and significant improvement in both the I-V characteristics and the spectral responsivities of the devices were characterized.
A Survey on Data‐Driven 3D Shape Descriptors Rostami, R.; Bashiri, F. S.; Rostami, B. ...
Computer graphics forum,
February 2019, 2019-02-00, 20190201, Letnik:
38, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Recent advances in scanning device technologies and improvements in techniques that generate and synthesize 3D shapes have made 3D models widespread in various fields including medical research, ...biology, engineering, etc. 3D shape descriptors play a fundamental role in many 3D shape analysis tasks such as point matching, establishing point‐to‐point correspondence, shape segmentation and labelling, and shape retrieval to name a few. Various methods have been proposed to calculate succinct and informative descriptors for 3D models. Emerging data‐driven techniques use machine learning algorithms to construct accurate and reliable shape descriptors. This survey provides a thorough review of the data‐driven 3D shape descriptors from the machine learning point of view and compares them in different criteria. Also, a comprehensive taxonomy of the existing descriptors is proposed based on the exploited machine learning algorithms. Advantages and disadvantages of each category have been discussed in detail. Besides, two alternative categorizations from the data type and the application perspectives are presented. Finally, some directions for possible future research are also suggested.
Recent advances in scanning device technologies and improvements in techniques that generate and synthesize 3D shapes have made 3D models widespread in various fields including medical research, biology, engineering, etc. 3D shape descriptors play a fundamental role in many 3D shape analysis tasks such as point matching, establishing point‐to‐point correspondence, shape segmentation and labelling, and shape retrieval to name a few. Various methods have been proposed to calculate succinct and informative descriptors for 3D models. Emerging data‐driven techniques use machine learning algorithms to construct accurate and reliable shape descriptors.
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