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Citrus, a raw material widely used in food and medicine, is susceptible to fungal infection and its metabolites during growth, transportation, and storage. Thus, monitoring the residual levels of various mycotoxins in Citrus traditional Chinese medicines and related products is crucial. This study described a simple, reliable, and sensitive method for simultaneous identification and quantification of 30 mycotoxins in Citrus products. The method is based on modified quick, easy, cheap, effective, rugged, and safe extraction and purification followed by ultra-high-performance liquid chromatography-quadrupole/orbitrap high-resolution mass spectrometry. The limit of detection ranged from 0.10 to 1.50 μg/kg, and the quantification ranged from 0.25 to 5.00 μg/kg. The recoveries at three spiked levels were 64.90-99.72% and the relative standard deviation was less than 12%. The method was applied to 55 Citrus samples. The detection rates of tentoxin and mycophenolic acid were the highest, reaching 22.7% and with concentration ranges of 0.33-1.03 and 0.57-2.09 μg/kg, respectively. All contamination levels were below the maximum residue limits recommended by the European Commission and China. These results could be used to establish guidelines for screening mycotoxins in Citrus products and the limits of acceptable levels.

Chemical investigation of the culture extract of an endophytic Penicillium citrinum from Dendrobium officinale, afforded nine citrinin derivatives ( 1 – 9 ) and a peptide-polyketide hybrid GKK1032B ( 10 ). The structures of these compounds were determined on the basis of spectroscopic methods. The absolute configurations of 1 and 2 were determined for the first time by calculations of electronic circular dichroism (ECD) data. Among them, GKK1032B ( 10 ) showed significant cytotoxicity against human osteosarcoma cell line MG63 with an IC50 value of 3.49 μmol·L–1, and a primary mechanistic study revealed that it induced the apoptosis of MG63 cells via caspase pathway.

Background . The coronavirus disease (COVID-19) pandemic has been a continuous global threat since the first identification of the disease in December 2019. COVID-19 vaccination is a crucial preventive approach that can halt this pandemic. However, many factors affect the willingness of the public to be vaccinated against COVID-19 at the early stage of the vaccination programme. We used network analysis to investigate the interrelation of vaccination willingness and its associated factors. Methods . A population-representative sample of 539 Chinese adults completed a battery of online self-assessments, including those on vaccination willingness, health status, attitude towards vaccines, COVID-19-related psychological elements and other variables. Network analysis was performed using the R qgraph package. Results . In total, 445 (82.6%) participants scored high on their willingness to vaccinate. Attitude towards vaccines, the influence of people around an individual and health status were directly significantly related to vaccination willingness. The betweenness of age was the highest and, the emotional states had the strongest centrality. Limitations . Network analysis is not sufficient to determine the causal relationships of the links between nodes. In addition, there are other latent essential elements that were not evaluated. Finally, the sample size was relatively small. Conclusion . Network analysis showed that attitude toward vaccines and emotional states are the most critical factors affecting vaccination willingness, which indicates that we should pay attention to the impact of the dissemination of Internet information on vaccination willingness and public emotional states during a pandemic which is very important for promoting vaccination programs.

A novel wideband wide-scanning phased array is presented in this paper, in which a new cavity-backed array element is employed. The proposed element consists of a probe-fed open-ended microstrip line backed by an open cavity and four parasitic metal striplines printed on the upper superstrate. It presents the advantages of compact size, simple feed structure, and low profile. The dual-resonance behavior of the proposed element results in a simulated bandwidth of 53.5% (7.8–13.5 GHz) for VSWR ${\le} 2$ . To compose the array, the open-backed cavities of adjacent antenna elements are connected rather than isolated to each other. The infinite array unit cell achieves about 43.4% bandwidth (7.4–11.5 GHz) with active VSWR ${\le} 2$ when scanning up to ±60°, and nearly 44% bandwidth (7.45–11.65 GHz) with VSWR ${\le} 2.5$ when scanning up to ±70° in all azimuth planes. For verification purpose, a $2\times18$ array prototype is fabricated and it experimentally achieves nearly 51% bandwidth (7.2–12.1 GHz) with VSWR ${\le} 2.3$ as scanning to 60 °, and more than 54% bandwidth (7.2–12.5 GHz) with VSWR ${\le} 3.2$ up to 70° in the H-plane, showing close agreements with simulations.

This double-blind field study tested the effectiveness of a baby-eyes image in promoting healthcare workers’ hand-hygiene compliance in a hospital setting. Adults are inclined to take care of babies and aspire to be their role models; therefore, they should wash their hands thoroughly when being watched by babies. Participants were healthcare workers from the obstetrical and neonatology units of a women’s hospital in Hangzhou. We recorded and coded 3,360 hours and 10,325 hand-hygiene events over a five-week period—from 16 October to 20 November 2018. Three types of stickers, depicting baby eyes, adult eyes, or flowers, were placed above handwashing basins to compare hand-hygiene behavior between the three conditions. Each condition continued for one week, and experimenters interchanged the stickers in each unit to control for the location and sequence effects. Participants in the baby-eyes condition (72.9%) were more likely to use sanitizer than those in the flowers condition (69.4%; χ2 = 9.74, p c = 0.034). Moreover, participants in the baby-eyes condition were more likely to use sanitizer than those in the adult-eyes condition (70.8%); however, the difference only trended towards significance ( χ2 = 2.38, p = .066, φc = 0.023). The mean handwashing time between the three conditions was significant (Welch’s F(2, 3488.436) = 3.50, p 2 = 0.001). Washing time in the baby-eyes condition (17.41 ± 12.02) was significantly longer than in the adult-eyes condition (16.36 ± 11.47; p

The photocatalytic performance of layered double hydroxides (LDH) is usually confined to the slow interface mobility and high recombination rate of photogenerated electron-hole pairs in material. To overcome the low photocatalytic efficiency, novel Ag

In this communication, an H-plane sparse cavity-backed antenna array is proposed, and by using multiport elements, the number of array control components such as transmitting/receiving modules, phase shifters, and power dividers is reduced, and therefore cost of the phased array is saved. In the array, each subarray consists of an active and a passive element, and the active element not only works as an antenna but also as a power divider to feed the passive one. A reflection-type phase shifter (RTPS) is designed and integrated between the two elements, whose phase shift is controlled by two reflective loads. The distance between the neighboring active elements is $1.225{\lambda}_{0}$ ( ${\lambda}_{0}$ is the free-space wavelength at the center of the operating frequency band), twice of that between the active and the passive elements. Meanwhile, cavity-backed structure is adopted to obtain unidirectional radiation patterns with high aperture efficiency. The proposed array can be used in both wide-angle scanning and limited field-of-view applications. Simulated and measured results are given and discussed to validate the proposed idea.

An efficient decoupling feeding network is proposed in this letter. It is composed of two directional couplers and two sections of transmission line for connection use. By connecting the two couplers, an indirect coupling with controlled magnitude and phase is introduced, which can be used to cancel out the direct coupling caused by space waves and surface waves between array elements. To demonstrate the method, a two-element microstrip antenna array with the proposed network has been designed, fabricated and measured. Both simulated and measured results have simultaneously proved that the proposed method presents excellent decoupling performance. The measured mutual coupling can be reduced to below $-58 ~\hbox{dB}$ at center frequency. Meanwhile it has little influence on return loss and radiation patterns. The decoupling mechanism is simple and straightforward which can be easily applied in phased array antennas and MIMO systems.

An implementation of circularly polarized crossed dipoles in millimeter-wave band is presented in this paper. Novel detached crossed dipoles have been designed to tackle the problems confronted by single-fed crossed dipoles in mm-wave band. An evolution procedure from conventional crossed dipoles to the proposed ones is given. Meanwhile, a metallic ridge is added in the cavity to provide a robust feeding structure. Measurements of an optimized antenna prototype show that it can achieve a bandwidth from 27 to 36.8 GHz for both AR ≤ 3 dB and |S11| ≤ -10 dB and an average broadside gain of 12.4 dBi. The measured results agree reasonably well with simulations. For reference to practical designs, studies on five critical parameters have also been performed in this paper.

Controlling the mutual coupling between array elements is one of the key problems in phased array designs. In this letter, a wideband decoupling network is proposed to suppress the mutual coupling between adjacent array elements. It is shown that the employment of the proposed network leads to a significant improvement of the operating bandwidth under the condition of maintaining a wide scan range, compared with conventional feeding techniques. In this manner, a 1 × 16 stack patch phased array prototype with the proposed decoupling network was fabricated. Measurement results agree well with simulated ones and indicate the effectiveness of the proposed approach in designing a wideband wide-angle scanning phased array.

The aim of this study is to simulate the growth process of fine Sediment flocculation fractal, which based on DLCA and three graphics technology. With the simulation, we analyze the effects of particle effective collision probability, initial concentration and particle diameter on sedimentation distance and distribution. The flow fractal structure was analyzed by graphic technology. Researches in this study have some theoretical and practical value on the control and treatment of Yellow River high turbidity flow.

In this letter, a microstrip phased array adopting an overlapped feeding network in order to achieve wide-angle impedance matching is proposed. A 1 × 16 phased array prototype has been designed and fabricated for experimental verification. Coupling coefficients and active element patterns for all the radiating elements have been measured to calculate the active reflection coefficients and to synthesize the array radiation patterns. Simulated and measured results show that the investigated method is effective to improve the impedance matching over a wide scan range compared to conventional impedance-matching techniques. Due to the improved impedance matching especially at large angles, the array can experimentally scan to ±60 ° with a gain decrease lower than 3 dB.

Hydrodynamics based numerical model is an effective way to simulate the movement of flood and its result can be visualized by many post-processing softwares. However, most of these tools are available only as local applications. This both limits the accessibility of the software to a specific machine and collaborative research. In this paper, we introduce a four-layer architecture for web-based visualization of numerical model. The application uses VTK(Visualization Toolkit) to render the numerical result and then the VRML standard is used to provide dynamic features over the web. By developing web-based visualization tools, it is possible for users to access the situation of flood wherever the internet is available, and can largely promotes the public services such as flood risk management.

The vehicle routing problem of relief supplies distribution, a typical NP-hard problem, is a hot topic in transportation research. Aiming at a two-echelon supply chain made up of a set of depots and stricken-points, the paper studies the problem how to decide delivery objects and the optimal delivery scheme; This paper decomposes the distribution VRP of relief supplies into an assignment problem and a problem similar to Traveling Salesman Problem, applies the theory of Thiessen Tessellation in spatial analysis to solve the assignment problem. For the sake of the problem of relief supplies distribution with uncertain time, a concept of risk exceeding time has been brought forth, and a multi-layer planning model with the least risk exceeding time has been established, too. At last, an example for this algorithm is given to prove the applicability of the model.

OBJECTIVE: To gain insight into the molecular events of lymph node metastasis of human gastric carcinoma. METHODS: The gene expression profile of five matched primary gastric carcinomas and their lymph node metastases was analyzed by complementary DNA (cDNA) microarray. Differential genes were identified in the metastatic and corresponding primary tumor pairs. Among the differentially expressed genes, carbonic anhydrase II (CAII) and insulin-like growth factor binding protein 4 (IGFBP 4) genes were detected by RT-PCR. CTTN protein expression was examined by tissue microarray. RESULTS: There was a high expression (over twofold) of 44 genes and a low expression (under twofold) of 32 genes in lymph node metastasis compared with primary gastric carcinoma, respectively. CAII mRNA was downregulated and IGFBP 4 mRNA was upregulated in paired lymph node metastases of gastric carcinomas. The overexpression of CTTN protein was related to the lymph node metastasis and the clinical stage of gastric carcinomas. CONCLUSION: This study showed that there is a low expression of genes relative to growth signal and immune response in lymph node metastases, and a high expression of genes relative to growth factor, cell cycle, cell motility and adhesion in lymph node metastases compared with primary gastric carcinomas. The expression of CTTN was related to the invasion and metastasis of gastric cancer.

A unified macroscopic continuum model is proposed to calculate the long-wavelength optical phonons of single-walled boron nitride nanotubes. The effect of the polarity in the boron nitride nanotubes on optical vibrations is considered by this model. We obtain the dispersion relation of the optical phonons. The avoided crossing between longitudinal and transverse optical phonon branches arises from the indirectly coupling between different phonon branches. The diameter dependence of the optical phonon frequency is derived. Our results are in agreement well with the experiment ones [R. Arenal, A.C. Ferrari, S. Reich, L. Wirtz, J.-Y. Mevellec, S. Lefrant, A. Rubio, A. Loiseau, Nano Lett. 6 (2006) 1812].

Bone tissue engineering is a promising way to repair of bone defects. To choose a proper scaffold is still a disputable problem in bone tissue engineering. This study aimed to compare the effects of repairing critical calvarial defects with the compounds of autogenous bone marrow stromal cells (BMSCs) and coral hydroxyapatite(CHA), hydroxyapatite/ tricalcium phosphate (HA/TCP), poly(lactide-co-glycolide) (PLGA) and alginate (AG). The results showed that CHA and AG were satisfactory bone tissues engineering scaffolds among the four kinds of materials. BMSCs/CHA and BMSCs/AG are promising techniques for reconstruction of bone defects.