Double neutron star (DNS) merger events are promising candidates of short gamma-ray burst (sGRB) progenitors as well as high-frequency gravitational wave (GW) emitters. On August 17, 2017, such a ...coinciding event was detected by both the LIGO-Virgo gravitational wave detector network as GW170817 and Gamma-Ray Monitor on board NASA's Fermi Space Telescope as GRB 170817A. Here, we show that the fluence and spectral peak energy of this sGRB fall into the lower portion of the distributions of known sGRBs. Its peak isotropic luminosity is abnormally low. The estimated event rate density above this luminosity is at least Formula: see text Gpc
yr
, which is close to but still below the DNS merger event rate density. This event likely originates from a structured jet viewed from a large viewing angle. There are similar faint soft GRBs in the Fermi archival data, a small fraction of which might belong to this new population of nearby, low-luminosity sGRBs.
Black phosphorous (BP), the most thermodynamically stable allotrope of phosphorus, is a high-mobility layered semiconductor with direct band-gap determined by the number of layers from 0.3 eV (bulk) ...to 2.0 eV (single layer). Therefore, BP is considered as a natural candidate for broadband optical applications, particularly in the infrared (IR) and mid-IR part of the spectrum. The strong light-matter interaction, narrow direct band-gap, and wide range of tunable optical response make BP as a promising nonlinear optical material, particularly with great potentials for infrared and mid-infrared opto-electronics. Herein, we experimentally verified its broadband and enhanced saturable absorption of multi-layer BP (with a thickness of ~10 nm) by wide-band Z-scan measurement technique, and anticipated that multi-layer BPs could be developed as another new type of two-dimensional saturable absorber with operation bandwidth ranging from the visible (400 nm) towards mid-IR (at least 1930 nm). Our results might suggest that ultra-thin multi-layer BP films could be potentially developed as broadband ultra-fast photonics devices, such as passive Q-switcher, mode-locker, optical switcher etc.
Dry/wet cycling driven by water level fluctuation in wetlands may strongly influence the destiny of seeds. However, how dry/wet cycling affects spore survival and germinability in peatland bryophytes ...is poorly understood.
Six peatland bryophytes, three hummock‐ and three hollow‐dwelling Sphagnum species, were chosen as study species. We tested the effects of dry (60% air RH)/wet (waterlogging) cycle frequency (once per 12, 8 or 4 days for low, medium or high, respectively) and ratio (3:1, 1:1 or 1:3 dry:wet time per cycle) on spore germinability, viability, dormancy percentage and protonema development.
Dry/wet cycling significantly reduced spore germination percentage and viability and slowed protonema development in all Sphagnum species, being more pronounced with higher dry/wet cycling frequencies. The hummock species S. capillifolium and S. fuscum had higher spore germination percentage after the continuous dry treatment, while the hollow species S. angustifolium, S. squarrosum and S. subsecundum showed the opposite response, compared to the continuously wet treatment. Except for S. squarrosum, spore viability was higher after the dry than after the wet treatment. Spore viability and dormancy percentage were higher after a dry/wet ratio of 1:3 than after ratios of 3:1 and 1:1.
Our study shows that both germinability and viability of bryophyte spores are reduced by dry/wet cycling (especially when frequent) in peatlands. This emphasizes the need to ensure constant water levels and low frequencies of water level fluctuation, which are relevant in connection with wetland restoration, to promote Sphagnum spore survival and establishment in peatlands after disturbances.
Dry/wet cycling, especially when frequent, significantly decreases germination potential of Sphagnum spores, suggesting the importance of water level management in peatland vegetation restoration.
Abstract
STUDY QUESTION
What is the current status of assisted reproductive technology (ART) service availability, efficacy and safety in mainland China?
SUMMARY ANSWER
In this first national report ...on ART status in mainland China, data on treatment numbers, outcomes and complications in 2016 are provided and analyzed, respectively.
WHAT IS KNOWN ALREADY
National ART Service Provision Surveys are conducted in mainland China regularly. Data were analyzed, and this manuscript was written by team members from the National Center for Women and Children’s Health, China CDC and the Department of Women and Children Health, National Health Commission of the People’s Republic of China.
STUDY DESIGN, SIZE AND DURATION
A cross-sectional nationwide survey was completed in 2018, in which data regarding ART treatments, performed from 1st January to 31st December2016 in 445 ART clinics located in 31 provinces of mainland China, were collected.
PARTICIPANTS/MATERIALS, SETTING AND METHODS
There were in total 451 licensed ART clinics (including artificial insemination clinics) in mainland China in 2016, of which 445 submitted service data. A total of 906 840 cycles were provided by 323 in vitro fertilization (IVF) clinics, involving 375 770 conventional IVF cycles, 154 948 intracytoplasmic sperm injection (ICSI) cycles, 367 146 frozen embryo transfer (FET) thawing cycles and 8976 preimplantation genetic diagnosis (PGD) treatment cycles. A total of 161 376 artificial (i.e. intrauterine) insemination (AI) cycles were reported by 443 clinics, with 126 872 cycles using the husband’s semen (AIH) and 34 504 using donor semen (AID).
MAIN RESULTS AND THE ROLE OF CHANCE
In total, 98.7% of the licensed clinics, contributing to 100% of the ART services (including AID and AIH cycles), were included in this report. (Six clinics provided institutional information only and were excluded.) There were 906 840 in vitro fertilization cycles performed in mainland China with a population of over 1.3 billion inhabitants, with cycles per million inhabitants (C/M) increasing from 360 in 2013 to 657 in 2016, nationwide (range among provinces: 45–3676). After treatment with conventional IVF, the clinical pregnancy rate (PR) per oocyte retrieval cycle was 23.2%, the delivery rate (DR) per oocyte retrieval cycle was 18.7% and the proportion of twin delivery among the total deliveries was 27.9%. For ICSI cycles, the PR, DR and TDR were 20.5%, 16.7% and 27.2%, respectively. For FET per thawing cycles, the PR, DR and TDR were 48.2%, 37.6% and 24.2%. For PGD per diagnosis cycles, the PR, DR and TDR were 38.1%, 29.7% and 4.2%. For AIH cycles, the PR and DR were 13.3% and 10.5%; for AID cycles, the PR and DR were 24.3% and 21.1%, respectively. The total number of live infants born in mainland China in 2016, was 18.46 million, and the number of infants born through ART conducted in 2016 was 311 309, which accounted for 1.69% of the total. The reported rate of birth defects was about 87/10 000. The incidence of moderate to severe ovarian hyper-stimulation syndrome (OHSS) was 11.5 per 1000 oocyte retrieval cycles, and other complications were much more rare.
LIMITATIONS AND REASONS FOR CAUTION
This report is based on the summary data of ART services provided. The success rates were not calculated by age stratification. A low rate of birth defects was reported, which might be confounded by variations in birth follow-up methods, statistical timing and record taking.
WIDER IMPLICATIONS OF THE FINDINGS
ART service availability has improved significantly in recent years in mainland China. Because China is a vast country, significant imbalances in ART service provision do exist; however, the main efficacy and safety indicators were close to those of western countries.
TRIAL REGISTRATION NUMBER
N/A
STUDY FUNDING/COMPETING INTEREST(S)
The study was funded by the National Key R&D Program of China (2016YFC1000307–2). There are no competing interests.
Learning from a few examples (one/few-shot learning) on the fly is a key challenge for on-device machine intelligence. We present the first chip-level demonstration of one-shot learning with Stanford ...Associative memory for Programmable, Integrated Edge iNtelligence via life-long learning and Search (SAPIENS), a resistive random access memory (RRAM)-based non-volatile associative memory (AM) chip that serves as the backend for memory-augmented neural networks (MANNs). The 64-kb fully integrated RRAM-CMOS AM chip performs long-term feature embedding and retrieval, demonstrated on a 32-way one-shot learning task on the Omniglot dataset. Using only one example per class for 32 unseen classes during on-chip learning, SAPIENS achieves 79% measured inference accuracy on Omniglot, comparable to edge software model accuracy using five-level quantization (82%). It achieves an energy efficiency of 118 GOPS/W at 200 MHz for in-memory L1 distance computation and prediction. Multi-bank measurements on the same chip show that increasing the capacity from three banks (24 kb) to eight banks (64 kb) improves the chip accuracy from 73.5% to 79%, while minimizing the accuracy excursion due to bank-to-bank variability.
Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease that was caused by a novel bunyavirus, SFTSV. The study aimed to disclose the epidemiological and clinical ...characteristics of SFTSV infection in China so far. An integrated clinical database comprising 1920 SFTS patients was constructed by combining first-hand clinical information collected from SFTS sentinel hospitals (n = 1159) and extracted data (n = 761) from published literature. The considered variables comprised clinical manifestations, routine laboratory tests of acute infection, hospitalization duration and disease outcome. SFTSV-IgG data from 19 119 healthy subjects were extracted from the published papers. The key clinical variables, case-fatality rate (CFR) and seroprevalence were estimated by meta-analysis. The most commonly seen clinical manifestations of SFTSV infection were fever, anorexia, myalgia, chill and lymphadenopathy. The major laboratory findings were elevated lactate dehydrogenase, aminotransferase, followed by thrombocytopenia, lymphocytopenia, elevated alanine transaminase and creatine kinase. A CFR of 12·2% was estimated, significantly higher than that obtained from national reporting data, but showing no geographical difference. In our paper, the mortality rate was about 1·9 parts per million. Older age and longer delay to hospitalization were significantly associated with fatal outcome. A pooled seroprevalence of 3·0% was obtained, which increased with age, while comparable for gender. This study represents a clinical characterization on the largest group of SFTS patients up to now. A higher than expected CFR was obtained. A wider spectrum of clinical index was suggested to be used to identify SFTSV infection, while the useful predictor for fatal outcome was found to be restricted.
Background and Aims
Mutations in the disheveled, Egl‐10 and pleckstrin domain‐containing protein 5 (DEPDC5) gene have emerged as an important cause of various familial focal epilepsy syndromes. ...However, the significance of DEPDC5 mutations in patients with sporadic focal epilepsy has yet to be characterized.
Materials and Methods
We studied a kindred of familial focal epilepsy with variable foci using whole‐exome sequencing. We subsequently studied a cohort of 293 patients with focal epilepsy and sequenced all exons of DEPDC5 using targeted resequencing.
Results
We reported a Taiwanese family with a novel splice site mutation which affected mRNA splicing and activated the downstream mammalian target of rapamycin (mTOR) pathway. Among patients with focal epilepsies, the majority (220/293) of these patients had sporadic focal epilepsy without malformation of cortical development. Two (0.9%) of these patients had probably pathogenic mutations in the
DEPDC5 gene.
Discussion and Conclusions
Our finding suggests that DEPDC5 is not only the most common gene for familial focal epilepsy but also could be a significant gene for sporadic focal epilepsy. Since focal epilepsies account for more than 60% of all epilepsies, the effect of mTORC1 inhibitor on patients with focal epilepsy due to DEPDC5 mutations will be an important future direction of research.
ABSTRACT
High time resolution and accuracy are of critical importance in the studies of timing analysis and time delay localization of gamma-ray bursts (GRBs), soft gamma-ray repeaters (SGRs) and ...pulsars. The Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) consisting of two micro-satellites, GECAM-A and GECAM-B, launched on 2020 December 10, is aimed at monitoring and locating X-ray and GRBs all over the sky. To achieve its scientific goals, GECAM is designed to have the highest time resolution (0.1 $\mu {\rm s}$) among all GRB detectors ever flown. Here, we make a comprehensive time calibration campaign including both on-ground and on-orbit tests to derive not only the relative time accuracy of GECAM satellites and detectors, but also the absolute time accuracy of GECAM-B. Using the on-ground calibration with a $\rm ^{22}Na$ radioactive source, we find that the relative time accuracy between GECAM-A and GECAM-B is about 0.15 $\mu {\rm s}$ (1σ). To measure the relative time accuracy between all detectors of a single GECAM satellite, cosmic-ray events detected on orbit are utilized since they could produce many secondary particles simultaneously record by multiple detectors. We find that the relative time accuracy among all detectors onboard GECAM-B is about 0.12 $\mu {\rm s}$ (1σ). Finally, we use the novel Li-CCF method to perform the absolute time calibration with Crab pulsar and SGR J1935+2154, both of which were jointly observed by GECAM-B and Fermi/GBM, and obtain that the time difference between GECAM-B and Fermi/GBM is 3.06 ± 6.04 $\mu {\rm s}$ (1σ).
The super τ-charm facility (STCF) is an electron−positron collider proposed by the Chinese particle physics community. It is designed to operate in a center-of-mass energy range from 2 to 7 GeV with ...a peak luminosity of 0.5 × 10 35 cm −2·s −1 or higher. The STCF will produce a data sample about a factor of 100 larger than that of the present τ-charm factory - the BEPCII, providing a unique platform for exploring the asymmetry of matter-antimatter (charge-parity violation), in-depth studies of the internal structure of hadrons and the nature of non-perturbative strong interactions, as well as searching for exotic hadrons and physics beyond the Standard Model. The STCF project in China is under development with an extensive R&D program. This document presents the physics opportunities at the STCF, describes conceptual designs of the STCF detector system, and discusses future plans for detector R&D and physics case studies.
This study investigated the effects of freezing temperature on the failure modes of frozen sandstone under uniaxial compression loading conditions. First, the sandstone specimens were subjected to ...freezing treatments at different temperatures (e.g., 20, 0, − 5, − 10, − 15 and − 20 °C), and uniaxially compressed to failure in the frozen state. Subsequently, the real-time CT scanning was performed to observe the spatial three-dimensional and planar two-dimensional fracture morphology of the failed specimens. Next, the volumetric porosity and crack area were introduced to quantitatively describe the freezing temperature effects on the damage degree of specimens after compression failure. Finally, the box-counting dimension of cracks calculated by fractal theory and distribution images of crack orientation angle were used to quantitatively evaluate freezing temperature effects on the compression failure complexity of specimens. The results show that the tension-shear failure mode to shear failure mode occurs as temperature decreases, and the failure mode tends to be constant below − 10 °C. The volumetric porosity and crack area of the failed specimen decrease as temperature decreases. After specimen failure, the box-counting dimension of cracks decreases as temperature decreases, and the distribution range of crack orientation angle decreases, which indicates the failure complexity decreases.
Highlights
Uniaxial compressive spatial failure modes of frozen sandstones were investigated.
Tension-shear failure mode to shear failure mode occurred as temperature decreased.
Failure mode tended to be constant as temperature decreased below − 10 °C.
Compression failure complexity of specimens decreased as temperature decreased.
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