Scattering of arbitrarily incident Laguerre-Gaussian vortex electromagnetic beams by electrically large-scaled complex targets.

We implement an algorithm, termed parallel-processing physical optics, providing an efficient high-frequency approximation method to characterize the scattering of Laguerre-Gaussian (LG) vortex electromagnetic (EM) beams by electrically large-scaled complex targets. The incident beam is described by vector expressions in terms of electric and magnetic fields, and it is combined with rotation Euler angles to achieve an arbitrary incidence of the vortex beam. The validity and capability of the proposed method are illustrated numerically, and the effects of various beam parameters as well as target geometric models such as a blunt cone and Tomahawk-A missile on monostatic and bistatic radar cross section distributions are investigated. Results show that the scattering features of the vortex beam vary significantly with the parameters of the vortex beam and the target. These results are helpful to reveal the scattering mechanism of LG vortex EM beams and provide a reference for the application of vortex beams to detect electrically large-scaled targets.

An Energy-Efficient Bayesian Neural Network Implementation Using Stochastic Computing Method.

The robustness of Bayesian neural networks (BNNs) to real-world uncertainties and incompleteness has led to their application in some safety-critical fields. However, evaluating uncertainty during BNN inference requires repeated sampling and feed-forward computing, making them challenging to deploy in low-power or embedded devices. This article proposes the use of stochastic computing (SC) to optimize the hardware performance of BNN inference in terms of energy consumption and hardware utilization. The proposed approach adopts bitstream to represent Gaussian random number and applies it in the inference phase. This allows for the omission of complex transformation computations in the central limit theorem-based Gaussian random number generating (CLT-based GRNG) method and the simplification of multipliers as and operations. Furthermore, an asynchronous parallel pipeline calculation technique is proposed in computing block to enhance operation speed. Compared with conventional binary radix-based BNN, SC-based BNN (StocBNN) realized by FPGA with 128-bit bitstream consumes much less energy consumption and hardware resources with less than 0.1% accuracy decrease when dealing with MNIST/Fashion-MNIST datasets.

Urban ecological security pattern construction coupled with risk and service: A case study of Xianyang City, Shaanxi Province, China.

How to combine regional ecological risks and local ecological needs to construct ecological security is one of the main issues of its application in territorial spatial governance and associated with whether it can be effectively applied. Based on the "source" accessibility and the quality of space, we constructed the ecological security pattern of Xianyang City through the way of source-corridor-node. During the construction processes, we combined the cha-racteristics of topography, influencing factors of regional ecological security, and landscape characteristics. We coupled them with morphological spatial pattern analysis (MSPA) and comprehensive evaluation results of ecological resistance, ecological connectivity and ecosystem service value, and superimposed with ecological gradient ana-lysis. The results showed that there were 66 ecological sources, with a total area of 2506.65 km2, accounting for 24.6% of the total area of Xianyang City, which were mainly distributed in the northeast, west and central mountainous areas. There were 106 ecological corridors with a total length of 823.5 km, including potential corridors, water systems, irrigation canal sites, Qinzhidao and other natural and cultural systems, which extended along the ecological source to the northwest and south Weihe River. There were 20 ecological nodes to improve ecological connectivity, which were mainly distributed between second layers of loess tableland and arid mountainous areas with banded distribution in the north part of the city.

Study of the Significance of Thromboelastography Changes in Patients with Dyslipidemia.

Purpose: To investigate the changes in thromboelastography (TEG) in patients with dyslipidemia to study its effect on the blood coagulation status. Methods: 131 patients hospitalized in Fujian Provincial Jinshan Hospital from January 2018 to December 2020 were selected, and 64 cases in the hyperlipidemia (HL) group and 67 cases in the non-HL group were set according to whether their blood lipids were abnormal. By measuring the changes of each parameter of TEG in patients, the relevant parameters R value, K value, α angle, and MA value were calculated. And routine blood coagulation (PT, APTT, INR, FIB, and TT) and routine blood (platelet count) tests were performed on all study subjects to analyze the changes of each index of the coagulation function and each parameter of TED in both groups and explore the clinical value of TEG on HL diseases. Results: Compared with the non-HL group, R and K values decreased, and angle and MA values increased in the HL group (P < 0.05). PT, APTT, and INR values decreased, and FIB values increased in the HL group compared with the nonhyperlipidemic group (P < 0.05). The TT levels were similar in the non-HL group and the HL group (P > 0.05). Compared with the non-HL group, PLT values decreased, and PDW and MPV values increased in the HL group (P < 0.05). R value was positively correlated with APTT, r= 0.373, P=0.002. K value was negatively correlated with PLT, r= -0.399, P=0.002. α angle and MA values were positively correlated with PLT, r= 0.319/0.475, P=0.010/P < 0.001. The rest of the indexes did not correlate with each parameter of TEG significant correlation. Conclusion: TEG can predict the hypercoagulability and hypocoagulability of blood by the changes of R value, K value, α angle, and MA to evaluate the effect of hyperlipidemia on the coagulation status, which is important for guiding the adjustment of lipid-lowering, antithrombotic, and anticoagulation programs in patients with atherosclerosis combined with hyperlipidemia or postsurgery combined with hyperlipidemia.

Formation Mechanism of Spherical TiC in Ni-Ti-C System during Combustion Synthesis.

The formation mechanism of TiC particles in a Ni-Ti-C system were revealed by using differential thermal analysis (DTA), XRD, and SEM to identify the reaction products in different temperature ranges. The results indicated that the synthesis mechanism of TiC in Ni-Ti-C system was complex; several reactions were involved in the combustion synthesis of TiC-Ni composite. The Ni-Ti intermediate phases play important roles during the formation of TiC. Moreover, the influence of heating rate on the size range of TiC was also discussed.

Impact of sertraline salt form on the oxidative stability in powder blends.

Oxidation of active pharmaceutical ingredients is a common chemical degradation process occurring in solid dosage forms. The aim of this study was to investigate the tendency of various sertraline salts to oxidize in powder blends containing a basic additive. A different extent of conversion of each salt to the free base was observed to occur in the presence of the basic additive, consistent with their respective pHmax values. Sertraline was found to undergo oxidation as the unioinized form, in both solution and powder blends that incorporated an oxidizing agent. In contrast, the ionized form of sertraline remained stable in both cases. Three sertraline salts undergoing a significant extent of conversion from salt to free form in the presence of tribasic sodium phosphate were found to oxidize extensively while sertraline benzoate which had a considerably lower extent of free base formation was more resistant to oxidation. The oxidative degradants were produced through oxidation at the amine functional group of sertraline which is where sertraline is ionized as the salt form. The link between oxidation tendency and the ionization state of sertraline in powder mixtures has thus been demonstrated in this study.

WYE-120318, a ring contraction product of methylnaltrexone, and structure revision of coniothyrione.

A contracted ring degradation product, WYE-120318 (compound 2), was discovered during the development phase for methylnaltrexone bromide (compound 1) drug substance. The compound was isolated by high-performance liquid chromatography fractionation, and its structure was determined by spectroscopic data analyses. WYE-120318 is formed from methylnaltrexone through a benzyl-benzilic acid type rearrangement reaction to yield an α-hydroxy-cyclopentanecarboxylic acid substructure. The proposed structure and the formation mechanism are confirmed by the synthesis of WYE-120318 from methylnaltrexone (compound 1). A similar benzyl-benzilic acid type rearrangement reaction can be envisioned as the biological origin of remisporine A (compound 3), a naturally occurring cyclopentadienyl compound that autocatalytically dimerizes to remisporine B (compound 4). The structure of remisporine A was deduced from its dimer 4. Coniothyione (compound 5) can be considered as the first example of a stable natural product bearing the remisporine A skeleton. However, the regiochemistry of the chlorosubstitution in the coniothyrione structure needs to be revised to compound 6 on the basis of the nuclear magnetic resonance data and biogenesis analysis.

Design and synthesis of HCV agents with sequential triple inhibitory potentials.

The union of HCV-796, a potent selective HCV NS5B polymerase inhibitor, and Ribavirin, a molecule with activities against a wide spectrum of viruses, resulted in a class of new anti-HCV agents with a sequential triple inhibitory mechanism.

Tricyclic azepine derivatives: pyrimido[4,5-b]-1,4-benzoxazepines as a novel class of epidermal growth factor receptor kinase inhibitors.

A novel class of pyrimido[4,5-b]-1,4-benzoxazepines is described as inhibitors of epidermal growth factor receptor (EGFR) tyrosine kinase. Two compounds display potent EGFR inhibitory activity of less than 1 microM in cellular phosphorylation assays (IC(50) 0.47-0.69 microM) and are highly selective against a small kinase panel. Such compounds demonstrate anti-EGFR activity within a class that is different from any known EGFR inhibitor scaffolds. They also provide a basis for the design of kinase inhibitors with the desired selectivity profile.

N-(4-{[4-(1H-Benzoimidazol-2-yl)-arylamino]-methyl}-phenyl)-benzamide derivatives as small molecule heparanase inhibitors.

A novel class of N-(4-{[4-(1H-benzoimidazol-2-yl)-arylamino]-methyl}-phenyl)-benzamides are described as inhibitors of the endo-beta-glucuronidase heparanase. Among them are N-(4-{[4-(1H-benzoimidazol-2-yl)-phenylamino]-methyl}-phenyl)-3-bromo-4-methoxy-benzamide (15h), and N-(4-{[5-(1H-benzoimidazol-2-yl)-pyridin-2-ylamino]-methyl}- phenyl)-3-bromo-4-methoxy-benzamide (23) which displayed good heparanase inhibitory activity (IC(50) 0.23-0.29 microM), with the latter showing oral exposure in mice.

1-[4-(1H-Benzoimidazol-2-yl)-phenyl]-3-[4-(1H-benzoimidazol-2-yl)-phenyl]-urea derivatives as small molecule heparanase inhibitors.

A novel class of 1-[4-(1H-benzoimidazol-2-yl)-phenyl]-3-[4-(1H-benzoimidazol-2-yl)-phenyl]-ureas are described as potent inhibitors of heparanase. Among them are 1,3-bis-[4-(1H-benzoimidazol-2-yl)-phenyl]-urea (7a) and 1,3-bis-[4-(5,6-dimethyl-1H-benzoimidazol-2-yl)-phenyl]-urea (7d), which displayed good heparanase inhibitory activity (IC(50) 0.075-0.27 microM). Compound 7a showed good efficacy in a B16 metastasis model.

Pyrimido-oxazepine as a versatile template for the development of inhibitors of specific kinases.

Pyrimido-oxazepine based sub-micromolar inhibitors (2-4) for Aurora and FLT-3 were designed and synthesized. These preliminary results supported the potential use of pyrimido-oxazepines as a versatile template for developing specific kinase inhibitors.

Intramolecular syn and anti hydrosilylation and silicon-assisted cross-coupling: highly regio- and stereoselective synthesis of trisubstituted allylic alcohols.

[reaction: see text] The geometrical isomers of 6-ethylidenedioxadisilacyclohexane were prepared by intramolecular hydrosilylation of an unsymmetrical disiloxane by the use of Pt (syn) and Ru (anti) catalysts. This new class organosilicon reagents underwent cross-coupling reactions with a range of aryl iodides to afford (E)- and (Z)-trisubstituted allylic alcohols in a highly stereospecific fashion.

Intramolecular anti-hydrosilylation and silicon-assisted cross-coupling: highly regio- and stereoselective synthesis of trisubstituted homoallylic alcohols.

A highly regio- and stereoselective anti-intramolecular hydrosilylation of alkynyl silyl ethers catalyzed by a ruthenium arene complex has been developed. The resultant (Z)-alkylidenesilacyclopentanes are efficiently coupled with aryl or alkenyl halides in the presence of tetrabutylammonium fluoride and a palladium(0) catalyst. The yields are generally good, and the reaction is compatible with a wide range of functional groups. The overall transformation achieves the stereoselective conversion of homopropargyl alcohols to trisubstituted homoallylic alcohols. [reaction: see text]