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TThe photovoltaic properties of binary and ternary blends of a polymer with molecular non-fullerene and fullerene acceptors are systematically investigated to provide morphology-charge dynamics–device performance design rules for future PSC development.

Dupuytren disease (DD) is a progressive fibrous proliferative disease. It invades the palmar aponeurosis and extends to the finger fascia, eventually leading to flexion contracture of the metacarpophalangeal or interphalangeal joint. At present, surgical resection and the local injection of collagenase are the main methods for the treatment of DD, but postoperative complications and high recurrence rates often occur. Bioinformatics analysis showed that the increased expression of SFRP4 protein was closely related to the incidence of DD. Persistent and effective inhibition of SFRP4 expression may be a promising treatment for DD. We prepared SFRP4 siRNA/nanoparticle complexes (si-SFRP4) and negative siRNA/nanoparticle complexes (NC) and applied them in vitro and in vivo. Flow cytometry analysis showed that si-SFRP4 could be successfully transfected into DD cells. MTT and EdU staining assays showed that the OD values and percentage of EdU-positive cells in the si-SFRP4 group were significantly lower than those in the NC group. Scratch tests showed that the wound healing rate of the si-SFRP4 group was lower than that of the NC group, and the difference was statistically significant. The expression of SFRP4 and α-SMA protein in the si-SFRP4 group significantly decreased in both DD cells and xenografts. Compared with the NC group, the xenograft quality of the si-SFRP4 group was significantly reduced. Masson's trichrome staining showed that the collagen and fibrous cells in the si-SFRP4 group were more uniform, slender, parallel and regular. The above experimental results suggest that the proliferation and metabolism of palmar aponeurosis cells and the quality of metacarpal fascia xenografts were both significantly decreased. We speculated that nanoparticle-mediated SFRP4 siRNA can be used as a potential new method for the treatment of DD.

Organic cocrystal engineering refers to two or more organic molecules stoichiometrically combined and held together by noncovalent intermolecular interactions, which differs from standard chemical synthesis involving covalent bond breakage and formation. Organic cocrystals have unique properties and offer a new strategy for creating enhanced organics. First, however, some key questions need to be addressed: How do diverse monomers affect the intermolecular interaction kinetics during cocrystallization? How do the intermolecular forces in cocrystals affect cocrystal functions? In this Perspective, the definition and advantages of organic cocrystal engineering, specifically in the construction of a reliable intermolecular interaction-stacking structure-performance relationship, are outlined. Additionally, recent developments in the field and the questions above are discussed. Finally, a brief conclusion and some hints on likely future developments are provided.

Cocrystals based on arene–perfluoroarene interactions exhibit better photocatalytic activity than monocrystals for pollutant degradation in water, with implications for the design of next generation photocatalyst materials.

The end-capping group (EG) is the essential electron-withdrawing component of nonfullerene acceptors (NFAs) in bulk heterojunction (BHJ) organic solar cells (OSCs). To systematically probe the impact of two frequent EG functionalization strategies, π-extension and halogenation, in A-DAD-A type NFAs, we synthesized and characterized four such NFAs: BT-BIC, LIC, L4F, and BO-L4F. To assess the relative importance of these strategies, we contrast these NFAs with the baseline acceptors, Y5 and Y6. Up to 16.6% power conversion efficiency (PCE) in binary inverted OSCs with BT-BO-L4F combining π-extension and halogenation was achieved. When these two factors are combined, the effect on optical absorption is cumulative. Single-crystal π-π stacking distances are similar for the EG strategies of π-extension. Increasing the alkyl substituent length from BT-L4F to BT-BO-L4F significantly alters the packing motif and eliminates the EG core interactions of BT-L4F. Electronic structure computations reveal some of the largest NFA π-π electronic couplings observed to date, 103.8 meV in BT-L4F and 47.5 meV in BT-BO-L4F. Computed electronic reorganization energies, 132 and 133 meV for BT-L4F and BT-BO-L4F, respectively, are also lower than Y6 (150 meV). BHJ blends show preferential π-face-on orientation, and both fluorination and π-extension increase NFA crystallinity. Femto/nanosecond transient absorption spectroscopy (fs/nsTA) and integrated photocurrent device analysis (IPDA) indicate that π-extension modifies the phase separation to enhance film ordering and carrier mobility, while fluorination suppresses unimolecular recombination. This systematic study highlights the synergistic effects of NFA π-extension and fluorination in affording efficient OSCs and provides insights into designing next-generation materials.

The advent of crescent-shaped Y6 and its derivatives have recently enabled exceptionally high solar cell performance metrics, for structural, physical, and transport characteristics that remain poorly understood. Here we summarize recent progress on crystallography, electronic structure, and device performance of this kind of non-fullerene acceptors. First, we discuss molecular engineering and the crystal structure of Y6 and its derivatives. Second, we present theoretical modeling of the molecular orbitals, reorganization energy, and electronic couplings. Third, we summarize single carrier diode and solar cell performance, and discuss the correlations between crystal structure and computational insights. Finally, we discuss unsolved problems and future developments in this field. Overall, this Minireview summarizes crystal structure, computational understanding, and device metrics, thus providing an outlook for future organic semiconductors design and mechanistic studies in fundamental research and industrial applications.

Cocrystal has been discovered and studied for more than 170 years since 1844, while the applications to optoelectronics only begin in the last decade. Several general questions that chemists and materials scientists currently seek to answer are: can we design and control the molecular self-assembly and cocrystal growth, what’s the packing-property correlations, as well as how can we improve device parameters for real applications in industry. In this contribution, we review our and other groups’ recent advances in the cocrystal research field sequentially including: (1) nucleation and growth mechanisms for selective preparation of cocrystals with different donor/acceptor ratio and morphology; (2) charge transport and electronic devices, particularly field-effect transistor (FET) and photo-response device. We discuss the in-situ single crystal device fabrication method, ambipolar charge transport, and molecular packing-charge separation correlation; (3) photonic and optical property, focusing on optical waveguide, photonic logic computation, and nonlinear optics (NLO). We present unusual optical properties revealed by advanced instruments and general structure-function relations for future study. Importantly, the extensive investigations described herein yield in-depth and detailed understandings of molecular cocrystals, and show that such bi-component material systems together with the developed instrument measurement methodologies have the potential to initiate unconventional electronic and photonic science and technology.

Two-dimensional (2D) cocrystals open a new way to get 2D functional materials via crystal engineering instead of molecular engineering. Here, large-area 2D cocrystals with length reaching several millimeters with strong near-infrared (NIR) absorption have been successfully designed and prepared. Driven by the intermolecular charge-transfer (CT) interactions, zinc tetraphenylporphyrin (donor) and C 60 (acceptor) self-assemble into a NIR cocrystals with absorption wavelength up to 1080 nm. By tailoring the growth solvents and processes, the cocrystal morphologies can be tuned from 1D nanowires, 2D nanosheets to large-area 2D cocrystal films with length reaching several millimeters. Impressively, due to the highly ordered donor-acceptor arrangement, the CT absorption in the 2D cocrystals is significantly enhanced and becomes comparable to singlet absorption. The uniform 2D cocrystals, with enhanced CT absorption in the NIR region, displays a high responsivity of 2424 mA/W to NIR light and a fast response time of 0.6 s. The excellent device performance can be attributed to the generation of long-lived free charge carriers as revealed by transient absorption spectroscopy and the optimization of device configuration. This work shows an example of controlled growth of 2D cocrystals for broadband photodetectors, which reveals the brilliant future of cocrystal films for high-performance electronics and paves their way towards large-scale, integrated, flexible, practical applications.

Increasing human activities have caused serious disturbance to global forest resources, so how to accurately identify individual trees has become an important task of forest resources investigation. In order to get the accurate number of individual trees, this paper took coniferous forest and mixed coniferous and broad-leaved forest as experimental samples, as well as Digital Orthophoto Map and airborne LiDAR Point Cloud as research data. We propose a deep Learning individual tree segmentation method based on RetinaNet model and PCS algorithm by doing comparative analysis (classical Watershed Algorithm and Layer Stacking Algorithm) at the plots (with high, medium, and low densities). The experimental results show that the method proposed in this paper can solve the problem of individual tree segmentation in high density forest and improve its degree of automation. Compared with Watershed algorithm and Layer stacking algorithm, F-Measure is improved by 6%-29% and 7%-20%, respectively. In other words, the results of individual tree segmentation presented in this paper can not only improve the precision of individual tree segmentation, but also maintain a high detection rate, which can meet the accuracy and high efficiency of individual tree extraction, so as to meet the needs for modern forestry investigation.

A new inverse synthetic aperture radar (ISAR) imaging framework is proposed to obtain high cross-range resolution under sparse aperture conditions, which is a challenge when the signal-to-noise ratio is low. Motivated by the sparsity and low rank of target’s 2-D distribution, the imaging problem is converted to the simultaneously sparse and low-rank signal matrix reconstruction problem under multiple measurement vector (MMV) model, and a novel reconstruction method based on joint constraints of sparsity and low rank is proposed. Due to the over-relax problem, the traditional convex optimization method cannot achieve a better performance using joint structures than exploiting just one of the constraints. As such, a nonconvex penalty function is introduced. To avoid the local minima, the convexity of the cost function should be ensured when constructing the nonconvex penalty function. The adaptive filtering framework, which is a powerful way to recovery the sparse low-rank matrix accurately from its noisy observation, is adopted as a reconstruction algorithm. Furthermore, the optimal step size formula and the idea of smoothed zero norm are used to enhance the convergence and the ability to suppress noise. The newly proposed method is verified by the simulation experiment, which has a better performance in image quality, robustness to noise, and imaging speed.

Organic semiconductors with long-range exciton diffusion length are highly desirable for optoelectronics but currently remain rare. Here, the estimated diffusion length of singlet excitons (LD ) in 2,6-diphenyl anthracene (DPA) crystals grown by solvent evaporation was shown to be up to approximately 124 nm. These crystals showed a previously unseen parallelogram morphology with layer-by-layer edge-on molecular stacking, isotropic optical waveguiding, radiation rate and non-radiation rate constants of 0.15 and 0.26 ns-1 respectively, as well as good field-effect transistor hole mobility and theoretically computed strong electronic couplings as high as 109 meV. Photoresponse experiments revealed that the photoconductivity of DPA crystals is surprisingly not related to the radiative pathway but associated with rapid exciton diffusion to the crystal surface for charge separation and carrier bimolecular recombination. Taken together, DPA was shown to be a promising semiconducting material for a new organic optoelectronics paradigm.

Emerging nonfullerene acceptors (NFAs) with crystalline domains enable high-performance bulk heterojunction (BHJ) solar cells. Thermal annealing is known to enhance the BHJ photoactive layer morphology and performance. However, the microscopic mechanism of annealing-induced performance enhancement is poorly understood in emerging NFAs, especially regarding competing factors. Here, optimized thermal annealing of model system PBDB-TF:Y6 (Y6 = 2,2'-((2Z,2'Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2″,3'':4',5']thieno[2',3':4,5]pyrrolo[3,2-g]thieno[2',3':4,5]-thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile) decreases the open circuit voltage (VOC) but increases the short circuit current (JSC) and fill factor (FF) such that the resulting power conversion efficiency (PCE) increases from 14 to 15% in the ambient environment. Here we systematically investigate these thermal annealing effects through in-depth characterizations of carrier mobility, film morphology, charge photogeneration, and recombination using SCLC, GIXRD, AFM, XPS, NEXAFS, R-SoXS, TEM, STEM, fs/ns TA spectroscopy, 2DES, and impedance spectroscopy. Surprisingly, thermal annealing does not alter the film crystallinity, R-SoXS characteristic size scale, relative average phase purity, or TEM-imaged phase separation but rather facilitates Y6 migration to the BHJ film top surface, changes the PBDB-TF/Y6 vertical phase separation and intermixing, and reduces the bottom surface roughness. While these morphology changes increase bimolecular recombination (BR) and lower the free charge (FC) yield, they also increase the average electron and hole mobility by at least 2-fold. Importantly, the increased μh dominates and underlies the increased FF and PCE. Single-crystal X-ray diffraction reveals that Y6 molecules cofacially pack via their end groups/cores, with the shortest π-π distance as close as 3.34 A, clarifying out-of-plane π-face-on molecular orientation in the nanocrystalline BHJ domains. DFT analysis of Y6 crystals reveals hole/electron reorganization energies of as low as 160/150 meV, large intermolecular electronic coupling integrals of 12.1-37.9 meV rationalizing the 3D electron transport, and relatively high μe of 10-4 cm2 V-1 s-1. Taken together, this work clarifies the richness of thermal annealing effects in high-efficiency NFA solar cells and tasks for future materials design.

The nucleation and growth mechanism and polymorph-property correlations in the molecular cocrystal field are widely sought but currently remain unclear. Herein, a new wire-like morphology of phenazine ( Phz )-chloranilic acid ( H2ca) cocrystal (PHC) is demonstrated for the first time, and the self-assembly of Phz and H2ca is controlled to selectively prepare kinetically stable wires and thermodynamically stable plates. Specifically, low precursor concentration is beneficial for one-dimensional (1D) self-assembly along the [010] crystallographic direction, while only supersaturation can trigger 2D self-assembly along the [100] and [010] directions, respectively. This is understandable in terms of the (020) face showing the largest attachment energy ( E att) and the (002) face possessing the smallest surface energy ( E surf). Moreover, anisotropic Raman spectra related to the mode symmetry and atomic displacements in two types of PHCs are revealed, and the same Raman-active vibrational bands of PHC wire and plate show different polarization responses, which is intrinsically ascribed to their different molecular orientations. Overall, this is the first case that morphologies of cocrystal are precisely tuned with comprehensive investigations of their anisotropic vibrational characteristics.

Background Discrepancies can occur with the use of clinical human immunodeficiency virus (HIV) diagnostic reagents for the HIV window period (WP; time from RNA to antibody detection by diagnostic or blood screening assays). Antiretroviral therapy (ART) during acute HIV infection can impact HIV-specific antibodies, antigens, and DNA/RNA detection. In this study, an HIV WP blood donor who initiated ART was monitored, evaluating the immunological and nucleic acid testing (NAT) results for early ART and discussing the potential effects on blood safety. Study design and methods This was a follow-up study of a HIV WP donor detected 36 hours after high-risk sexual behavior, who was subsequently treated with ART. Immunological and NAT methods were comparatively analyzed. Results The 4th generation HIV serologic assays were positive at Day 11, and the 3rd generation domestic anti-HIV assay was positive at Day 33. Individual donation (ID) NAT and minipool (MP) NAT of six samples were reactive, but 12-sample MP-NAT was nonreactive. ART resulted in a slow decline of HIV RNA, but HIV DNA was still detected on Day 757. Conclusion After ART, ID-NAT was more sensitive than MP-NAT or serologic detection; however, HIV DNA detection was more sensitive, with DNA but not RNA persistently detectable.

International audience; Objectives: Occult hepatitis B virus infection (OBI) carries a risk of hepatitis B virus (HBV) transmission and hepatocellular carcinoma. As previous studies have had a limited sample size, the characteristics of OBI with genotype B and C (OBIB and OBIC) mutations relating to hepatitis B surface antibody (anti-HBs) elicited by vaccination or a limited host immune response to HBV have not been fully explored.Methods: In this study, the occurrence of OBIB or OBIC strains associated with envelope protein (pre-S/S) amino acid substitutions obtained from 99 blood donors stratified according to anti-HBs carriage were characterized extensively.Results: According to the presence of anti-HBs within each genotype, the number and frequency of substitution sites specific for anti-HBs(-) OBIB were higher than those specific for anti-HBs(+) OBIB strains (67 vs 31; 117 vs 41), but the reverse pattern was found in OBIC strains (3 vs 24; 3 vs 26). Mutations pre-s1T68I and sQ129R/L were found uniquely in 15-25% of anti-HBs(+) OBIB carriers and mutation pre-s1A54E was found preferentially in anti-HBs(+) OBIC, while 17 substitutions were found preferentially in 11-38% of anti-HBs(-) OBIB strains. In the major hydrophilic region (MHR) region, mutations sS167 in OBIB, sT118 in OBIC, and sA166 in both genotypes were possibly immune-induced escape mutation sites.Conclusions: Several mutations in pre-S/S of OBI appeared to be associated with carrier anti-HBs pressure, which might be risk factors for potential reactivation of viruses under anti-HBs selection in OBI carriers.

The detection of SAR image ship targets in complex scenarios has been a great challenge. In this paper, the high performance algorithm framework of the improved YOLOv3 algorithm is proposed to increase the weight ratio of important feature regions and make full use of peripheral information. Finally, the experimental results show that the algorithm improves the accuracy compared with the original network.

Real-time and accurate evaluation of jamming effect is the key to implement intelligent jamming decision. The existing evaluation method of jamming effect based on radar side is too rough to serve the problem of radar jamming intelligent decision. Based on the syntactic model, a four-layers multi-functional radar signal mode (FMRSM) is proposed in this paper. By analyzing the behavior rules of multi-functional radar(MFR) in the process of radar countermeasure, an online evaluation model of multifunctional radar jamming effect is proposed in combination with FMRSM. The effectiveness of the jamming effect evaluation method is proved by experimental simulation under the background of aircraft penetration.

As a kind of microwave remote sensing imaging radar, Synthetic Aperture Radar (SAR) has been widely used in military and civil fields because of its advantages of all-weather and all-time imaging. Data is the "crude oil" to promote the development of deep learning. Aiming at the problem of how to use SAR data efficiently, this paper studies the data samples from different data source, different target sizes and different training sample sizes. Firstly, based on the SAR ship dataset, the expansion of specific samples is completed to increase the diversity of samples used in the experiment. Secondly, through the cross experiment of two data source, Sentinel-1 data has strong universality for different data source models. Further research on GF-3 data verifies that low resolution and small-scale target detection has great challenges, which provides some reference for researchers.

As a microwave remote sensing imaging radar, SAR has been widely used in military and civilian fields due to its advantages such as all-weather and all-day imaging. However, due to the exponential growth of image data, new SAR image target detection techniques are needed. Convolutional neural network provides a good idea for SAR target detection technology. For SAR images, the traditional target detection algorithm based on constant false alarm rate (CFAR) is firstly analyzed; then the target detection algorithm based on convolutional neural network is combed, including several algorithms based on candidate regions such as R-CNN and R-FCN, and several algorithms based on regression models such as YOLO and SSD. Finally, other target detection algorithms are introduced, the characteristics and the existing problems of various algorithms are analyzed. On this basis, the problems existing in SAR image target detection technology and further research are prospected.

With the development of depth learning and synthetic aperture radar (Synthetic Aperture Radar, SAR) technology, SAR image target detection based on convolution neural network (convolutional neural network, CNN) has achieved certain results. However, there are still problems in SAR detection of near-shore ship targets in complex environments. For improving the detection performance of the algorithm, the detection rate of SAR image near shore ship targets in complex environment is improved. This paper proposes an algorithm for SAR image ship target detection in complex environment. The algorithm first uses convolution neural network for coastal segmentation, and SAR image ship target detection through the results of coastal segmentation. The experimental results show that the algorithm has efficient detection ability for SAR image near-shore ship target detection in complex environment.

Aiming at the problem of low accuracy of ship detection in SAR images, we propose an improved detection method based on RetinaNet. This method introduces channel-wise attention mechanism into the backbone feature extraction network, in order to automatically obtains the importance of each feature channel by means of learning, and then enhances the useful features according to this importance and restrains the features that are not of much use to the detection task. In order to improve the capability of multi-scale detection, this method also introduces an efficient weighted bidirectional feature fusion network—BiFPN, which adjusts the proportion of each feature by learning the importance of features of different scales. In addition, we propose a training method to expand the complex background samples in the data set to improve the classification performance of the network to the targets and complex background. Training and testing with open SAR image ship detection datasets, the detection results show that this method can significantly improve the precision and recall rate.

As a frontier hot spot in the current image processing field, deep learning has unparalleled superiority in feature extraction. Deep learning uses deep network structure to perform layer-by-layer nonlinear transformation, which can achieve the approximation of complex functions. From low-level to high-level, the representation of features becomes more and more abstract, and the more essential the original data is described. Aiming at the problem of SAR image target detection, this paper studies the influence of the number of convolution kernels, the size of the convolution kernel and the number of convolution layers in the deep convolutional neural network on SAR target recognition.

To deal with the problem of de-noising and enhancement of radar signal time-frequency images, a method of secondary generating time-frequency images by generative adversarial network is proposed. Firstly, time-frequency analysis is used to generate the time-frequency image of the radar signal as the original data set 1. Then, after learning the data set 1 by using the generative adversarial network, a new data set 2 is generated, and the data set 2 has de-noising and enhancement effects relative to data set 1. Finally, the validity of the data set 2 generated by the time-frequency image singular value feature is checked. Experiments on the time-frequency images of five common radar signals are carried out. The results show that the method is effective in time-frequency image de-noising and increasing sample diversity.

Aiming at the problem that the previous recognition algorithms based on supervised learning are difficult to apply to non-cooperative multi-function radar, this paper proposes a radar phrase recognition algorithm based on new word discovery. The algorithm can effectively identify radar phrases without prior knowledge. It is verified by simulation experiments that with the increase of the input data size, the algorithm can overcome the problem of decreased phrase recognition rate caused by the loss of data quality. To a certain extent, the algorithm achieves the purpose of compensating for data “quality” with data “quantity”, and has good engineering applicability.

Background:The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic has affected almost every country. Interleukin-6 (IL-6), a cytokine secreted by CD4+ T cell, has been shown to be a reliable marker of disease severity and a useful parameter for monitoring progression of coronavirus disease-2019 (COVID-19). However its value as a predictor of severe disease has not been assessed.Methods:A total of 160 laboratory-confirmed COVID-19 patients admitted to two hospitals were enrolledand separated into two groups according to whether or not they progressed to develop severe illness. Demographic and clinical characteristics at admission were compared between the groups.Results: Patients who developed severe COVID-19 had significantly higher baseline IL-6 levels than patients who had mild disease course in hospital (P< 0.001). Patients were further grouped according to quartiles of IL-6 level. The cumulative incidence of severe illnesswas significantly higher in the third and fourth quartiles groups than in the first quartile group (55% vs. 15% and 80% vs. 15%, respectively;bothP< 0.001). In multivariate logistic regression analysis, the risk for developing severe disease was markedly higher in the highest IL-6 quartile than in the lowest quartile (odds ratio: 14.95; 95% confidence interval: 3.65–61.30; P< 0.001). Receiver operating characteristic curve analysis of potential predictive variables showed the area under the curve to be largest for baseline IL-6, with the value of 5.20 pg/mL having the best balance of sensitivity and specificity for predicting risk of severe COVID-19.Conclusion: Serum baseline IL-6 appears to be a reliable predictor of risk of severe COVID-19. Early intervention may be advisable in patients with serum IL-6 levels >5.20 pg/mL, even if initial symptoms are mild.

Aiming at the problem that the previous method of solving the optimal radar word based on matching classification technology is not suitable for the non-cooperative Multi-functional radar(MFR), this paper proposes a radar word set construction method based on PRI sequence clustering. The radar word set of MFR is extracted from the data set through PRI type identification, similarity measurement selection and clustering of waveform units. This method does not need to use the prior knowledge of the number and content of radar words, and has good engineering applicability. At the same time, the practicability and effectiveness of the proposed method are verified by the comparison simulation experiment with the traditional clustering algorithms.

BACKGROUND: Due to the low incidence of concurrent human immunodeficiency virus (HIV) and syphilis infection identified during the window period, little is known about the clinical manifestations, diagnosis, and treatment efficacy at very early stages.METHODS: One longitudinal study was conducted in a 42-year-old blood donor who was concurrently infected with syphilis and HIV. This blood donor was treated with a penicillin-based regimen and early antiretroviral therapy (ART). Immunological and NAT methods were comparatively analyzed.RESULTS: A regular male donor who had two occasions of high-risk sexual behaviors 41 and 35 days before donation(DBD) donated whole blood at the Shenzhen Blood Center. Antiretroviral therapy was initiated at the 28th day after donation (DAD), and syphilis treatment was received at the 49th DAD. Microbiological analysis using a 4th generation anti-HIV ELISA and CLIA indicated a positive signal at the 6th DAD. All NAT tests for HIV RNA were reactive except the minipool (MP) NAT of six pooled samples at 117th DAD. The HIV viral load declined more than 4-log in copies per milliliter over 3 months, until reaching non-detectable levels at 246th DAD. Nevertheless, HIV-1 DNA was still detectable at 403rd DAD. Among all methods utilized, anti-TP ELISA detected syphilis infection at the earliest time. Toluidine red unheated serum test (TRUST) was negative around the 80th DAD.CONCLUSION: Concurrent infection with Syphilis and HIV during window period did not significantly change the sensitivity of reagents in detection nor alter the therapeutic efficacy for the treatment of both pathogens.

As a significant part of GNSS navigation message, timing group delay is one of the main errors in GNSS applications such as navigation, positioning, timing and ionospheric estimation. DCB solution in One-TGD-fixed constraint condition is more suitable for Beidou regional satellite navigation system, in which the TGD parameter exit calibration value of a certain GEO satellite is fixed as the constraint condition. Based on the global ionospheric map provided by IGS as a reference, monthly TGD parameters in 2019 have been calculated to analyse the characteristics of satellite TGD changes. The results demonstrate that the stability of TGD parameters is from high to low in the order of GEO satellites, MEO satellites and IGSO satellites. The changes of all satellites in a year are within 1ns, and most of them are within 0.5 ns. Monthly changes in TGD-B1B2 are in -1.6 ~ 1.5ns, and TGD-B1B3 are in -1.4 ~ 1.2ns. TGD-B1B3 parameters are more stable than TGD-B1B2 parameters in monthly variation, with maximum changes in a month within 1.6ns for TGD-B1B2 and 1.3ns for TGD-B1B3, average changes in a month within 0.7ns for TGD-B1B2 and 0.5ns for TGD-B1B3.

Bistatic inverse synthetic aperture radar (ISAR) can increase the probability of tracking the high-speed target and provide more angle information than monostatic ISAR. However, bistatic ISAR suffers from a serious defocusing problem, resulting from the high-speed motion. Furthermore, the inherent geometry distortion and calibration problems make bistatic ISAR (B-ISAR) imaging more complex. In response to these problems, we propose a bistatic ISAR imaging method for high-speed moving target with geometric distortion correction and calibration based on dechirping processing. At first, based on the motion decomposition idea, the B-ISAR echo model of the high-speed moving target is established. Then, by analyzing the imaging mechanism of the Range-Doppler algorithm (RDA), we eliminate the phase items influencing the imaging quality with speed compensation and Doppler compensation. After that, the analytic formula of the geometric distortion factor and calibration factor are deduced, which helps transform the geometric correction and calibration problem into a parameter estimation problem. Finally, with the sparsity of the scattering points, the required parameters are solved using the expectation maximization (EM) algorithm based on the maximum a posteriori probability criterion. With the estimated parameters, a clear B-ISAR image of a high-speed moving target with geometric correction and calibration is obtained. The simulations show that the proposed method has a better resolution and simultaneously attains geometric correction and calibration of the image.

Indacenodithienothiophene (IDTT)-based postfullerene electron acceptors, such as ITIC (2,2'-[[6,6,12,12-tetrakis(4-hexylphenyl)-6,12-dihydrodithieno[2,3- d:2',3'- d']-s-indaceno[1,2- b:5,6- b']dithiophene-2,8-diyl]-bis[methylidyne(3-oxo-1 H-indene-2,1(3 H)-diylidene)]]bis[propanedinitrile]), have become synonymous with high power conversion efficiencies (PCEs) in bulk heterojunction (BHJ) polymer solar cells (PSCs). Here we systematically investigate the influence of end-group fluorination density and positioning on the physicochemical properties, single-crystal packing, end-group redistribution propensity, and BHJ photovoltaic performance of a series of ITIC variants, ITIC- nF ( n = 0, 2, 3, 4, and 6). Increasing n from 0 → 6 contracts the optical bandgap, but only marginally lowers the LUMO for n > 4. This yields enhanced photovoltaic short-circuit current density and good open-circuit voltage, so that ITIC-6F achieves the highest PCE of the series, approaching 12% in blends with the PBDB-TF donor polymer. Single-crystal diffraction reveals that the ITIC- nF molecules cofacially interleave with ITIC-6F having the shortest π-π distance of 3.28 A. This feature together with ZINDO-level computed intermolecular electronic coupling integrals as high as 57 meV, and B3LYP/DZP-level reorganization energies as low as 147 meV, rival or surpass the corresponding values for fullerenes, ITIC-0F, and ITIC-4F, and track a positive correlation between the ITIC- nF space-charge limited electron mobility and n. Finally, a heretofore unrecognized solution-phase redistribution process between the 2-(3-oxo-indan-1-ylidene)-malononitrile-derived end-groups (EGs) of IDTT-based NFAs, i.e., EG1-IDTT-EG1 + EG2-IDTT-EG2 ⇌ 2 EG1-IDTT-EG2, with implications for the entire ITIC PSC field, is identified and mechanistically characterized, and the effects on PSC performance are assessed.

Simultaneously modulating the optical and electrical properties of organic semiconductors is crucial for advancing their desired applications in integrated optoelectronic devices. Here, we realize a goal of optimizing the light emission and field-effect properties of an anthracene derivative, 1,4-di(anthracen-9-yl)buta-1,3-diyne (DABD) by tuning its crystal polymorphs. Two phase crystals, that is α-phase rhombic-sheet crystals and β-phase ribbon-shape crystals of DABD are controllably obtained. Compared with the α-phase crystals, the β-phase DABD crystals exhibit better integrated optoelectronic performances with charge carrier mobility of 0.25 cm2 V−1 s−1 and strong fluorescent emission. This work suggests that polymorph engineering would be a promising avenue to realize simultaneous modulation of the multifunctional properties of organic semiconductors towards appropriate applications in organic optoelectronics.

We show here that breath figure–derived semiconducting films are suitable and universal for porous organic electronics., Porous semiconductor film morphologies facilitate fluid diffusion and mass transport into the charge-carrying layers of diverse electronic devices. Here, we report the nature-inspired fabrication of several porous organic semiconductor-insulator blend films [semiconductor: P3HT (p-type polymer), C8BTBT (p-type small-molecule), and N2200 (n-type polymer); insulator: PS] by a breath figure patterning method and their broad and general applicability in organic thin-film transistors (OTFTs), gas sensors, organic electrochemical transistors (OECTs), and chemically doped conducting films. Detailed morphological analysis of these films demonstrates formation of textured layers with uniform nanopores reaching the bottom substrate with an unchanged solid-state packing structure. Device data gathered with both porous and dense control semiconductor films demonstrate that the former films are efficient TFT semiconductors but with added advantage of enhanced sensitivity to gases (e.g., 48.2%/ppm for NO2 using P3HT/PS), faster switching speeds (4.7 s for P3HT/PS OECTs), and more efficient molecular doping (conductivity, 0.13 S/m for N2200/PS).

A cocrystal strategy with a simple preparation process is developed to prepare novel materials for near-infrared photothermal (PT) conversion and imaging. DBTTF and TCNB are selected as electron donor (D) and electron acceptor (A) to self-assemble into new cocrystals through non-covalent interactions. The strong D-A interaction leads to a narrow band gap with NIR absorption and that both the ground state and lowest-lying excited state are charge transfer states. Under the NIR laser illumination, the temperature of the cocrystal sharply increases in a short time with high PT conversion efficiency (η=18.8 %), which is due to the active non-radiative pathways and inhibition of radiative transition process, as revealed by femtosecond transient absorption spectroscopy. This is the first PT conversion cocrystal, which not only provides insights for the development of novel PT materials, but also paves the way of designing functional materials with appealing applications.

A sensitive, and single step reaction assay of glycoproteins in antibody-free mode was proposed on a 4-mercapto-phenylboronic acid (4-MPBA) modified silver nanoparticle film (AgNF) by using surface enhanced Raman scattering (SERS). 4-MPBA/AgNF was designed both as a glycoprotein-specific recognition biosensor and as a Raman reporter for the SERS platform. Variation in the ratio I1574/I1586 for 4-MPBA/AgNF in response to glycoprotein capture constitutes the SERS assay which exhibits high sensitivity and selectivity against nonglycoproteins and is shown to function in complex samples.

Cocrystals of 4-styrylpyridine and 1,2,4,5-tetracyanobenzene were successfully prepared by supramolecular self-assembly. Donor-acceptor interactions between the molecular components are the main driving force for self-assembly and contribute to intermolecular charge transfer. The cocrystals possess two-photon absorption properties that are not observed in the individual components; suggesting that two-photon absorption originates from intermolecular charge-transfer interactions in the donor-acceptor system. The origin of two-photon absorption in multichromophore systems remains under-researched; thus, the system offers a rare demonstration of two-photon absorption by cocrystallization. Cocrystal engineering may facilitate further design and development of novel materials for nonlinear optical and optoelectronic applications.

The need for physicians and technical consultants specialized in transfusion medicine is urgent in China, as there are 20 000 hospitals and 500 blood centers in need of staff with this expertise. The progress made in transfusion medicine as a specialty has been relatively slow in China. Current Chinese medical education and service systems have not developed transfusion medicine as a stand-alone medical specialty. Most physicians receive only minimal training in transfusion medicine in medical school. This training is usually integrated into surgical training and addresses the most common technologies. In 2008, a 5-year bachelor's diploma program in transfusion medicine was established as an undergraduate specialty in Southern Medical University, Guangzhou, China. This article intends to summarize the 8 years of experience educating undergraduates in the specialty of transfusion medicine.

The co-contamination of farmland soils with heavy metals and antibiotics from the application of livestock and poultry manures poses great threats to human health. Phytoremediation might be a good solution to this problem. A pot culture experiment was conducted to evaluate the remediation capacity of two ornamental hyperaccumulators, namely, Mirabilis jalapa L. and Tagetes patula L., in alkaline soils co-contaminated with cadmium (Cd) and tetracycline antibiotics (TCs). The growth of M. jalapa and T. patula was significantly influenced by the co-contaminated soil. In treatments with TCs alone, the growth of T. patula was promoted (p

We investigate backbone fluorination effects in bulk-heterojunction (BHJ) polymer solar cells (PSCs) with the fluorine-poor PBDTT-FTTE and fluorine-rich PBDTTF-FTTE donor polymers, paired with the ...