28 research outputs found
Longitudinal compression of macro relativistic electron beam
We presented a novel concept of longitudinal bunch train compression capable
of manipulating relativistic electron beam in range of hundreds of meters. This
concept has the potential to compress the electron beam with a high ratio and
raise its power to an ultrahigh level. The method utilizes the spiral motion of
electrons in a uniform magnetic field to fold hundreds-of-meters-long
trajectories into a compact set-up. The interval between bunches can be
adjusted by modulating their sprial movement. The method is explored both
analytically and numerically. Compared to set-up of similar size, such as
chicane, this method can compress bunches at distinct larger scales and higher
intensities, opening up new possibilities for generating beam with ultra-large
energy storage.Comment: 6 pages, 6 figure
Research progress in finite element analysis of ankle sprains
Ankle dislocation is the most common sports injury and is often associated with sports injuries. Among them, the tendon ligament causes damage to the posterior ankle ligament and the posterior ankle ligament. Important stabilizing structures, especially the anterior fibula ligament and the heelofibular ligament, play an important role in maintaining balance, and their injuries can lead to instability on the lateral side of the ankle. This seriously affects the function of the ankle. At the same time, it has a stabilizing effect on the lower joint, and its damage will also affect the function of the lower joint. [1-2] Foreign scientists have collected cases of acute fractures of the ankle joint, but only the central ligament rupture. Almost all injuries to the central tendon can cause a partial tear of the ligament. However, severe hallux valgus abuse can still lead to isolated damage to the triangular ligament. [3-4] Study surface emography and other techniques for basic ankle fracture studies to address the biomechanical and kinematic problems of ankle sprains. The biomechanics of ankle injuries will now be discussed in conjunction with the mechanisms of ankle injuries. To discuss the biomechanics and kinematics of ankle sprains
Coherent perfect absorber and laser induced by directional emissions in the non-Hermitian photonic crystals
In this study, we propose the application of non-Hermitian photonic crystals
(PCs) with anisotropic emissions. Unlike a ring of exceptional points (EPs) in
isotropic non-Hermitian PCs, the EPs of anisotropic non-Hermitian PCs appear as
lines symmetrical about the point. The non-Hermitian Hamiltonian
indicates that the formation of EPs is related to the non-Hermitian strength.
The real spectrum appears in the Y direction and has been validated as
the complex conjugate medium (CCM) by effective medium theory (EMT). But for
the X direction, EMT indicates that the effective refractive index has
a large imaginary part, which forms an evanescent wave inside the PCs. Thence,
coherent perfect absorber (CPA) and laser effects can be achieved in the
directional emission of the Y. The outgoing wave in the X
direction is weak, which can significantly reduce the losses and
electromagnetic interference caused by the leakage waves. Furthermore, the
non-Hermitian PCs enable many fascinating applications such as signal
amplification, collimation, and angle sensors.Comment: 11 pages, 11 figure
Predicting Power Conversion Efficiency of Organic Photovoltaics: Models and Data Analysis.
Funder: Cambridge TrustFunder: National Research Foundation SingaporeFunder: Alexander von Humboldt-StiftungFunder: China Scholarship CouncilIn this paper, the ability of three selected machine learning neural and baseline models in predicting the power conversion efficiency (PCE) of organic photovoltaics (OPVs) using molecular structure information as an input is assessed. The bidirectional long short-term memory (gFSI/BiLSTM), attentive fingerprints (attentive FP), and simple graph neural networks (simple GNN) as well as baseline support vector regression (SVR), random forests (RF), and high-dimensional model representation (HDMR) methods are trained to both the large and computational Harvard clean energy project database (CEPDB) and the much smaller experimental Harvard organic photovoltaic 15 dataset (HOPV15). It was found that the neural-based models generally performed better on the computational dataset with the attentive FP model reaching a state-of-the-art performance with the test set mean squared error of 0.071. The experimental dataset proved much harder to fit, with all of the models exhibiting a rather poor performance. Contrary to the computational dataset, the baseline models were found to perform better than the neural models. To improve the ability of machine learning models to predict PCEs for OPVs, either better computational results that correlate well with experiments or more experimental data at well-controlled conditions are likely required
Retrievals of Arctic sea ice melt pond depth and underlying ice thickness using optical data
Melt pond is a distinctive characteristic of the summer Arctic, which affects energy balance in the Arctic system. The Delta-Eddington model (BL) and Two-strEam rAdiative transfer model (TEA) are employed to retrieving pond depth Hp and underlying ice thickness Hi according to the ratio X of the melt-pond albedo in two bands. Results showed that when λ1 = 359 nm and λ2 = 605 nm, the Pearson’s correlation coefficient r between X and Hp is 0.99 for the BL model. The result of TEA model was similar to the BL model. The retrievals of Hp for the two models agreed well with field observations. For Hi, the highest r (0.99) was obtained when λ1 = 447 nm and λ2 = 470 nm for the BL model, λ1 = 447 nm and λ2 = 451 nm for the TEA model. Furthermore, the BL model was more suitable for the retrieval of thick ice (0 < Hi < 3.5 m, R2 = 0.632), while the TEA model is on the contrary (Hi < 1 m, R2 = 0.842). The present results provide a potential method for the remote sensing on melt pond and ice in the Arctic summer
Prognostic value of inflammatory markers for in-hospital mortality in intensive care patients with acute ischemic stroke: a retrospective observational study based on MIMIC-IV
BackgroundAcute ischemic stroke (AIS) is a primary cause of death and disability worldwide. Four markers that can be readily determined from peripheral blood, namely, the systemic immune-inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and total bilirubin, were measured in this study. We examined the relationship between the SII and in-hospital mortality after AIS and evaluated which of the above four indicators was most accurate for predicting in-hospital mortality after AIS.MethodsWe selected patients from the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database who were aged >18 years and who were diagnosed with AIS on admission. We collected the patients’ baseline characteristics, including various clinical and laboratory data. To investigate the relationship between the SII and in-hospital mortality in patients with AIS, we employed the generalized additive model (GAM). Differences in in-hospital mortality between the groups were summarized by the Kaplan–Meier survival analysis and the log-rank test. The receiver operating characteristic (ROC) curve analysis was used to assess the accuracy of the four indicators (SII, NLR, PLR, and total bilirubin) for predicting in-hospital mortality in patients with AIS.ResultsThe study included 463 patients, and the in-hospital mortality rate was 12.31%. The GAM analysis showed a positive correlation between the SII and in-hospital mortality in patients with AIS, but the correlation was not linear. Unadjusted Cox regression identified a link between a high SII and an increased probability of in-hospital mortality. We also found that patients with an SII of >1,232 (Q2 group) had a considerably higher chance of in-hospital mortality than those with a low SII (Q1 group). The Kaplan–Meier analysis demonstrated that patients with an elevated SII had a significantly lower chance of surviving their hospital stay than those with a low SII. According to the results of the ROC curve analysis, the in-hospital mortality of patients with AIS predicted by the SII had an area under the ROC curve of 0.65, which revealed that the SII had a better discriminative ability than the NLR, PLR, and total bilirubin.ConclusionThe in-hospital mortality of patients with AIS and the SII were positively correlated, but not linearly. A high SII was associated with a worse prognosis in patients with AIS. The SII had a modest level of discrimination for forecasting in-hospital mortality. The SII was slightly better than the NLR and significantly better than the PLR and total bilirubin for predicting in-hospital mortality in patients with AIS
Genome-wide CRISPR/Cas9 library screen identifies C16orf62 as a host dependency factor for porcine deltacoronavirus infection
Porcine deltacoronavirus (PDCoV) is an emerging pathogen that can cause severe diarrhoea and high mortality in suckling piglets. Moreover, evidence of PDCoV infection in humans has raised concerns regarding potential public health risks. To identify potential therapeutic targets for PDCoV, we performed a genome-wide CRISPR/Cas9 library screening to find key host factors important to PDCoV infection. Several host genes in this screen were enriched, including ANPEP, which encodes the PDCoV receptor aminopeptidase N (APN). Furthermore, we discovered C16orf62, also known as the VPS35 endosomal protein sorting factor like (VPS35L), as an important host factor required for PDCoV infection. C16orf62 is an important component of the multiprotein retriever complex involved in protein recycling in the endosomal compartment and its gene knockout led to a remarkable decrease in the binding and internalization of PDCoV into host cells. While we did not find evidence for direct interaction between C16orf62 and the viral s (spike) protein, C16orf62 gene knockout was shown to downregulate APN expression at the cell surface. This study marks the first instance of a genome-wide CRISPR/Cas9-based screen tailored for PDCoV, revealing C16orf62 as a host factor required for PDCoV replication. These insights may provide promising avenues for the development of antiviral drugs against PDCoV infection
The Maunakea Spectroscopic Explorer Book 2018
(Abridged) This is the Maunakea Spectroscopic Explorer 2018 book. It is
intended as a concise reference guide to all aspects of the scientific and
technical design of MSE, for the international astronomy and engineering
communities, and related agencies. The current version is a status report of
MSE's science goals and their practical implementation, following the System
Conceptual Design Review, held in January 2018. MSE is a planned 10-m class,
wide-field, optical and near-infrared facility, designed to enable
transformative science, while filling a critical missing gap in the emerging
international network of large-scale astronomical facilities. MSE is completely
dedicated to multi-object spectroscopy of samples of between thousands and
millions of astrophysical objects. It will lead the world in this arena, due to
its unique design capabilities: it will boast a large (11.25 m) aperture and
wide (1.52 sq. degree) field of view; it will have the capabilities to observe
at a wide range of spectral resolutions, from R2500 to R40,000, with massive
multiplexing (4332 spectra per exposure, with all spectral resolutions
available at all times), and an on-target observing efficiency of more than
80%. MSE will unveil the composition and dynamics of the faint Universe and is
designed to excel at precision studies of faint astrophysical phenomena. It
will also provide critical follow-up for multi-wavelength imaging surveys, such
as those of the Large Synoptic Survey Telescope, Gaia, Euclid, the Wide Field
Infrared Survey Telescope, the Square Kilometre Array, and the Next Generation
Very Large Array.Comment: 5 chapters, 160 pages, 107 figure
The Construction of Muslim Minorities Image and the Communication of National Image through Media Discourse - A Case Study of China CGTNs Documentary on Xinjiang Uyghurs
Nowadays, the Muslim community is under the spotlight. The ongoing international debate over Muslim minorities identities reflects the dilemma of their integration into non-Muslim modern multi-ethnic nations under the context of multiculturalism. One typical example is the heated debate between the West and China over Chinese Muslims, also known as Uyghurs, through media discourse. Western media, such as the BBC, claim that China assimilates and forces Uyghurs to integrate. The Chinese side, meanwhile, asserts that mainstream Western media reports are lies, smears, and fake. Facing the discourse challenges from the West, China applies media discourse to reinforce its understanding of Uyghurs in the international discourse system. The analysis reveals that the Chinese government has consciously aligned the image of Uyghurs with its Chinese national image, and building a real Xinjiang image on CGTN
Research progress in finite element analysis of ankle sprains
Ankle dislocation is the most common sports injury and is often associated with sports injuries. Among them, the tendon ligament causes damage to the posterior ankle ligament and the posterior ankle ligament. Important stabilizing structures, especially the anterior fibula ligament and the heelofibular ligament, play an important role in maintaining balance, and their injuries can lead to instability on the lateral side of the ankle. This seriously affects the function of the ankle. At the same time, it has a stabilizing effect on the lower joint, and its damage will also affect the function of the lower joint. [1-2] Foreign scientists have collected cases of acute fractures of the ankle joint, but only the central ligament rupture. Almost all injuries to the central tendon can cause a partial tear of the ligament. However, severe hallux valgus abuse can still lead to isolated damage to the triangular ligament. [3-4] Study surface emography and other techniques for basic ankle fracture studies to address the biomechanical and kinematic problems of ankle sprains. The biomechanics of ankle injuries will now be discussed in conjunction with the mechanisms of ankle injuries. To discuss the biomechanics and kinematics of ankle sprains