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The TM02 mode has advantage in power capacity over the fundamental TM01 mode in relativistic backward-wave oscillator (RBWO), whereas in our formal experiment, the microwave pulse seemed not as wide as we expected. In this article, the power capacity of the TM02 mode is investigated theoretically and the mechanisms corresponding to the pulse shortening are analyzed in detail. It is found that the pulse shortening in the RBWO results from the breakdown on the window, the bombardment of the stray electrons traveling in the low guiding magnetic field, and the breakdown induced by the intensive electric field on the surface of the slow wave structure (SWS). The approach of eliminating the pulse shortening is put forward based on the theoretical research and the numerical optimization using our artificial intelligence (AI) code and is validated in the experiment. With larger aperture antenna adopted, post resonator simplified, and emitting electric field greatly decreased, the pulsewidth is lengthened from ~9 to 18 ns with the output power of 360 MW at guiding magnetic field of 0.9 T.

Dielectric energy storage materials are becoming increasingly popular due to their potential superiority, for example, excellent pulse performance as well as good fatigue resistance. Although numerous studies have focused on lead-free dielectric materials which possess outstanding energy storage characteristics, the results are still not satisfying in terms of achieving both large discharging energy density (Wd) and high discharging efficiency (η) under low electric fields, which is crucial to be conducted in miniatured electronic components. Here, we adopt the strategy of domain engineering to develop sodium bismuth titanate (Bi0.5Na0.5TiO3)-based ceramics employed in the low-field situation. Remarkably, a large Wd of 2.86 J/cm3 and an ultrahigh η of 90.3% are concurrently obtained in 0.94(Bi0.5Na0.5)0.65(Ba0.3Sr0.7)0.35TiO3-0.06 Bi(Zn2/3Nb1/3)O3 system when the electric field is as low as 180 kV/cm. Additionally, the ceramic shows brilliant thermal endurance (20-160 °C) and frequency stability (0.1-100 Hz) with high Wd (>1.48 J/cm3) together with an ultra-high η (>90%). What's more, the ceramic displays a fast charge-discharge time (t0.9 = 109.2 ns). The piezoresponse force microscopy (PFM) results reveal that the introduced Bi(Zn2/3Nb1/3)O3 disrupts the microdomains of (Bi0.5Na0.5)0.65(Ba0.3Sr0.7)0.35TiO3 ceramics and promotes the formation of nanodomains, leading to enhanced energy storage properties. The current work may arouse interest in developing low-field high-performing dielectric capacitors for energy storage application.

In this paper, through the application of 3D printing technology, insulators with different surface microstructures are prepared. Surface flashover test of the printed insulators shows that surface microstructures have a strong influence on the surface flashover voltage. This indicates that through proper surface microstructure design and the application of 3D printing technology insulators with high surface voltage withstand strength can be prepared. The influence of gas release characteristics, with and without thermal treatment, on the surface flashover voltages is studied. The results indicate that insulators with lower gas release rate own higher voltage withstand strength.

Deepwater oil and gas exploitation has become an important field in the petroleum industry development. However, there are still no mature methods for hydrate prevention in the deepwater wells clea...

Emotion-cause pair extraction (ECPE), which aims to extract emotions and the corresponding causes in documents, has a wide range of applications in network public opinion analysis. Current two-stage methods first extract emotion and cause clauses, and then pair them. However, there are two problems in these methods: 1) the unidirectional enhancement between emotion and cause extraction fails to make full use of the correlation between them; 2) the errors from the first stage directly degrade the performance of the second stage. To address these problems, we firstly propose a mutually auxiliary multitask model to promote the extraction of emotion and cause clauses by adding two auxiliary tasks which are identical to the original tasks. The proposed model uses the predicted results generated by the two auxiliary tasks as extra features of each other’s main tasks, so as to establish the bidirectional correlation between emotion and cause extraction. Secondly, to reduce the influence of error propagation on the second stage, we design a self-distillation method for pairwise tasks to train the proposed model, which further improve the accuracy of emotion and cause extraction. Experimental results on the ECPE benchmark dataset show that the proposed model has achieved good performance on emotion-cause pair extraction, outperforming the baseline models by 1.92% in F1 score.

Short half-life is one of the main causes of drug attrition in clinical development, which also leads to the failure of many leading compounds and hits to become drug candidates. Nowadays, nanomaterials have been applied to drug development to address this problem. In fact, the clinical application of nanoparticles (NPs) is severely limited due to their rapid elimination by the reticuloendothelial system (RES) in vivo. In this paper, we aim to summarize representative strategies on prolonging the circulation time for bridging the gap between excellent pharmaceutics and proper half-life and encourage clinical translation.

Purpose The purpose of this paper is to establish a strain prediction model of mining overburden deformation, to predict the strain in the subsequent mining stage. In this way, the mining area can be divided into zones with different degrees of risk, and the prevention measures can be taken for the areas predicted to have large deformation. Design/methodology/approach A similar-material model was built by geological and mining conditions of Zhangzhuang Coal Mine. The evolution characteristics of overburden strain were studied by using the distributed optical fiber sensing (DOFS) technology and the predictive model about overburden deformation was established by applying machine learning. The modeling method of the predictive model based on the similar-material model test was summarized. Finally, this method was applied to engineering. Findings The strain value predicted by the proposed model was compared with the actual measured value and the accuracy is as high as 97%, which proves that it is feasible to combine DOFS technology with machine learning and introduce it into overburden deformation prediction. When this method was applied to engineering, it also showed good performance. Originality/value This paper helps to promote the application of machine learning in the geosciences and mining engineering. It provides a new way to solve similar problems.

Transmembrane protein 16A was involved in the development of the monocrotaline-induced pulmonary arterial hypertension model through ERK1/2 activation, and it was considered as potential target for pulmonary arterial hypertension treatment. A pulmonary arterial hypertension rat model was established by intraperitoneal administration of monocrotaline. Noninvasive pulsed-wave Doppler and histological analysis was performed, and it revealed proliferation and remodeling of pulmonary arterioles and right ventricle hypertrophy. In addition, transmembrane protein 16A, proliferating cell nuclear antigen—a proliferate marker, P-ERK1/2 increased following monocrotaline treatment. Expression of transmembrane protein 16A in the pulmonary arteries was co-localized with a specific marker of vascular smooth muscle α-actin. Then, a specific inhibitor of transmembrane protein 16A-T16A inh -A01 was administered to pulmonary arterial hypertension rats. It was found to alleviate the remodeling of pulmonary arterioles and right ventricle hypertrophy significantly, and decrease the upregulation of proliferating cell nuclear antigen in monocrotaline-induced pulmonary arteries. In addition, T16A inh -A01 could inhibit the activation of ERK1/2 in pulmonary arterial hypertension model. Transmembrane protein 16A mediated the proliferation and remodeling of pulmonary arterioles in the monocrotaline-induced pulmonary arterial hypertension model. ERK1/2 pathway is one of downstream factors. Long-term use of T16A inh -A01 in vivo could alleviate remodeling and pressure in pulmonary arterial hypertension.

Consumer Internet-of-Things platforms, especially in smart home, have received widespread attention. A large number of end-to-end and edge-to-end wireless communication links are subject to significant security and privacy risks. Key generation using radio link side-channel information is a burgeoning technology to solve this problem. This article designs a symmetric key generation method without environmental constraints, namely, MobiKey. The basic idea is taking the human mobility in home or the swing of the antenna to generate symmetric keys based on channel reciprocity. We leverage the practical phase information as the channel feature to generate symmetric keys between two communicating parties. To overcome the effects of noise on both communication sides and get a better performance, MobiKey harnesses the adaptive quantization method to make the bit generation rate and bit matching rate higher. MobiKey also uses the adaptive inconsecutive samples to increase the confusion of the adversary. Moreover, we propose the D-Gray code to enhance the randomness of quantization. MobiKey is implemented on different commercial devices, and the results show that it has comparative advantages in key generation consistency, randomness, and security. In addition, the performance in preventing predictable channel attacks and eavesdropping attack is discussed.

Shopping behavior information acquisition and mining are of great importance for marketing and merchandizing strategies developing. With a single tag on each commodity, the previous pattern-based works only can be considered as behavior recognition solutions with behavior streams as output for each tag. In this article, we introduce a completely new mode of dual tags and propose a fine-grained shopping behavior acquisition solution called as fine-grained shopping behavior information acquisition (FGSA). FGSA enables shopping behaviors recognition by taking advantage of the phase calibrated Doppler shift of dual tags and extracts fine-grained behavior information for each behavior from the fusion Doppler spectrums with only one antenna. We implement a prototype of FGSA with COTS radio-frequency identification (RFID) devices and conduct extensive experiments to evaluate its performance. The experimental results demonstrate that FGSA achieves excellent performance in terms of both behavior recognition and information extraction.

Gallium nitride (GaN) HEMT has board application prospect for 5G wireless communication systems. This paper reviews the recent advance in space mapping technique for GaN HEMT modeling technique. A novel decomposed-based space mapping technique is discussed. This method is a systematic modeling approach with fast developing speed. A 2×350 µm GaN HEMT device are used as an example.

The prevention and control of natural gas hydrate (hereinafter, “hydrate” for short) blockage during deepwater gas well production tests is very important in ensuring the test safety. In this paper, the distribution of wellbore temperature and pressure field under different test conditions was analyzed, and the changes of hydrate deposition and blockage degree in the pipe string in the whole process of test under different test systems were evaluated using the hydrate generation–deposition–decomposition calculation method. On this basis, a deepwater gas well production test method based on hydrate prevention and control was proposed. And the following research results were obtained. First, in the process of deepwater gas well tests, the vapor–liquid phase of annular-mist flow pattern with the greatest risk of hydrate blockage is often formed in the wellbore. Therefore, it is more reasonable to take measures to prevent hydrate blockage in the process of tests than to prevent the formation of hydrate. Second, when the conventional four-point test method is used, it is required to set low gas production measurement points with lower flowing temperature. In the wellbore with high temperature and low temperature, however, hydrate tends to form and deposit easily, and a long period of test will increase the risk of test string blockage. Third, the mixed-sequence test system suitable for deepwater gas well tests can change wellbore temperature by adjusting the sequence of measuring points without changing the production rate and duration, so as to decompose hydrate sediment layers and reduce the maximum blockage degree of test string in the process of tests. Fourth, a three-point or two-point test method is recommended for deepwater gas wells without sand production, stress sensitivity, retrograde condensation and water production. Superior to the conventional four-point test method, three-point and two-point test methods can effectively reduce the risk of hydrate deposition and blockage in the test string, and it can shorten the testing time and reduce the test cost on the premise of ensuring the accuracy of the productivity equation. In conclusion, the research results are of help to the field test construction of deepwater gas wells. Keywords: Deepwater gas well, Production test, Natural gas hydrate, Prevention and control method, Mixed-sequence test, Pipe blockage degree, Flow assurance

An induction voltage adder (IVA) has been developed to drive rod-pinch diodes (RPDs), to produce X-rays for flash radiography. The IVA facility consists of four-stage induction cavities stacked in series, each of which is single-point driven by a 6- $\Omega $ pulseline. The prime pulsed-power source comprises two Marx generators and four de-ionized water pulselines. Each Marx generator fast charges two pulselines to about 2.2 MV in less than 370 ns. Four electrically triggered, SF6-insulated gas switches serve as energy-transfer switches from pulse-forming lines to output transmission lines, and thus without an additional intermediate energy storage. A stepped inner stalk is utilized to make the vacuum impedance of the secondary transmission line increase from $30~\Omega $ at the first cavity to $120~\Omega $ at the last cavity, to prevent the electron emission from cathode surfaces. The RPD is chosen to create bremsstrahlung X-rays, which are believed to be optimal at voltage levels of about 4 MV. In this article, the design details and experimental results concerning the main components, such as the Marx/PFLs, IVA, and RPD, are demonstrated. The electrical performances of the facility are characterized. Presently, the IVA provides voltages of up to 4.3 MV and currents of up to 85 kA. The X-ray dose is up to 15.5 Rad [lithium fluoride (LiF)] at 1 m with a spot size of 1.4 mm and a FWHM time of 55 ns.

The formation of hydrate will lead to serious flow assurance problems in deepwater submarine natural gas transmission pipelines. However, the accurate evaluation model of the hydrate blocking risk for submarine natural gas transportation is still lacking. In this work, a novel model is established for evaluating the hydrate risk in deepwater submarine gas pipelines. Based on hydrate growth-deposition mechanism, the mathematical model mainly consists of mass, momentum and energy conservation equations. Meantime, the model results are obtained by finite difference method and iterative technique. Finally, the model has been applied in the production of deepwater gas field (L Gas Field) in China, and the sensitivity analysis of relevant parameters has been carried out. The results show that: (a). The mathematical model can well predict the hydrate blockage risk in deepwater natural gas pipelines after verification. (b). Hydrate is easily formed at the intersection of horizontal pipeline and vertical riser, and the maximum blocking position often occurs in middle of the riser. (c). The hydrate blockage degree and length of hydrate formation region (HFR) decrease with the increase of gas transport rate. (d). The hydrate blockage degree and length of HFR decrease with the increase of gas transport temperature. (e). The hydrate blockage degree and length of HFR increase with the extension of horizontal pipeline. (f). Injecting inhibitors can effectively inhibit hydrate formation and blockage, but the improvement of transmission measures can significantly reduce the dosage of inhibitor. It is concluded that measures such as increasing gas transportation rate and temperature, shortening horizontal pipeline length, optimizing inhibitor injection point and injection rate can play a safe, economic and efficient role in hydrate preventing and controlling.

From last few years indoor localization has become more popular for wireless devices. The major reason for its popularity is to access current location efficiently. On the other side visible light communication is attaining interest of researchers due to high growth of wireless communication and solid state lighting. This network structure can produce high accuracy for the resident positioning electromagnetic environment. The proposed approach is viable for both air and underwater communication based on the visible light spectrum. We evaluate the technique for other supervised machine learning algorithms to analyse an accuracy, error distance and computational time for indoor localization in visible light communication network. Experimental work was made by using star topology supported by visible personal area network system based simulator, which corresponds an attribute of PHY and MAC layer for IEEE 802.15.7 standard designed for short range optical wireless communication. The evaluation was carried out for an accuracy, error distance and computational time. The results show that the suggested methodology achieves overall computational accuracy and deliver an acceptable location estimation error.

A large number of digital pictures have many security threats in the transmission on the Internet, and various encryption technologies for images have been proposed. The existing image encryption technology has a simple structure and a small key space, which cannot meet the requirement for image information security at this stage. In order to improve the effectiveness of image encryption and enhance the adaptive ability of image encryption, based on the theory of wavelet transform, chaos theory and adaptive encryption, this paper designs the overall framework of image encryption, and proposes a digital image adaptive encryption method based on lifting wavelet optimization. Firstly, the framework of image frequency domain adaptive encryption algorithm is designed, wavelet transform based on lifting is studied and analyzed, and lifting wavelet optimization method based on improved threshold method and particle swarm algorithm is given to improve the adaptability to image decomposition, so that the frequency domain coefficients obtained after wavelet decomposition can better represent the image content, thus making frequency domain encryption more targeted. Chaos mapping is used to encrypt the pixel gray value and scramble the pixel position of the decomposed low frequency coefficients of the image, thus achieving good image adaptive encryption.

To date, the development of coalbed methane (CBM) reservoirs has attracted a great deal of attention due to its considerable perspective reserves. As a result, nearly all research aspects of CBM reservoirs have been extensively investigated and expect to advance gas production performance as well as associated economic value. Notably, amongst the most significant issue influencing the production performance is the production strategy optimization, which however remains challenging because of the complex time-varying fluid flow performance during the development process of CBM reservoirs. It is always difficult but crucial to shed light on the optimal drawdown pressure within different production scenarios. According to the gas-water two-phase version productivity equations which have been proposed in our previous work, a set of quantified optimization criterion for production strategy within the entire CBM well production process is developed for the first time in this research paper. The proposed optimization criterion contains three procedures: (1) the gas well maintains the bottom-hole pressure (BHP) as critical desorption pressure until the pressure wave propagate to the boundary; (2) the BHP is set as the critical pressure, which is firstly proposed herein and determined by gas phase productivity equation, until the pressure at the boundary become below the critical desorption pressure; (3) the gas well maintains the BHP as the abandonment pressure. In order to clarify the validity of the proposed criterion, we applied the optimization criterion to an actual CBM well located in Hancheng field, China, and found the case with optimized production strategy achieved much better gas recovery compared with that based on the previous production strategy. Moreover, production evaluation work is performed based on the utilization of the proposed optimization method, it indicates that optimized gas production can attain relatively high gas production rate in the future three years. The optimization method possesses simple and easy-operation advantages, which shares great application potential in actual CBM fields and turns out to be practical. In addition, because a practical optimization method for scheduling production strategy of CBM wells has not been proposed before, this work is able to fill the knowledge gap and will contribute to the efficient development of CBM reservoirs.

Precise characterization of dynamic desorption area is crucial for accurate production prediction, production strategy formulation, and well pattern optimization of coalbed methane (CBM) reservoirs. However, little attention has been focused on this topic and a handful of related previous researches suffer some fatal deficiencies. Thus, the objective of this work is to overcome these deficiencies and then extensively investigate the propagation behavior of desorption area during CBM recovery. During depressurization development process of CBM reservoirs, due to the effect of gas desorption, gas saturation takes place in the original water-saturated coal seams, which will decrease the expansion speed of desorption area. Moreover, saturation distribution in the whole coal seam is a dynamic parameter during CBM recovery, which plays an important role for the propagation behavior of desorption area but has not yet been captured in current models. Firstly, pressure-squared concept is utilized to describe pressure distribution within desorption area, which has been considered as an effective method. Secondly, based on the partial differential equation of subface fluid flow accounting for gas desorption, the formulas for pressure-saturation relationship are derived. Finally, according to material balance equation for infinitesimal coal seams, a novel mathematical model for desorption area is developed. Results show that: (a) shape of desorption area will transition from ellipse into a circle with production proceed; (b) matrix shrinkage effect has few influences on the expansion of desorption area at a certain cumulative gas production; (c) rapid decrease of BHP will result in a small desorption area for actual production of CBM wells. The research, for the first time, provides an accurate and fast semi-analytical model to simulate propagation behavior of desorption area. Also, the proposed model is easier to setup and less data-intensive than a numerical simulator. Considering the interests for development of CBM reservoirs, the research can serve as an effective tool for gaining a better understanding of the flow physics in the whole coal seam.

BACKGROUND/OBJECTIVES Increased rates of histopathological misdiagnosis of melanoma have been associated with incisional punch more so than shave biopsy when compared with complete excisional biopsy. It is unknown how the increasing utilisation of shave biopsy may impact melanoma diagnosis. The extent to which the provision of clinical information to the pathologist may improve diagnostic accuracy remains unclear. This study assessed the impact of both initial biopsy technique and provision of adequate clinical information to pathologists on the accuracy of histopathological diagnosis of melanoma and disease progression. METHODS We conducted a retrospective cohort with nested case-control study of all histopathological false-negative and false-positive melanoma diagnoses from January 2014 to May 2019 from the Victorian Melanoma Service electronic database. Cases were assessed for the initial biopsy type, provision of clinical information on pathology request forms and disease progression associated with false-negative diagnosis. RESULTS Partial shave biopsy had higher odds of false-negative (OR 5.19, 95% CI 2.89-9.32; P

Background: Alzheimer's disease is a multifactorial neurological disorder seen in elderly people. Loss of cholinergic transmission and unbalanced tryptophan metabolism kynurenine pathway have been demonstrated in neuropsychiatric diseases. Methods & results: Among the two series of synthesized compounds, compounds 5c and 5h were identified as effective dual BChE/IDO1 inhibitors, with well-balanced micromolar activity. Compounds 5c and 5h exhibited promising ability to ameliorate behavioral impairment by Morris water maze. The safety of miconazole analogs was also validated by PC12 and SH-SY5Y cell lines. Conclusion: These results highlight the ability of 5c and 5h to treat Alzheimer's disease.

With the rapid development of the internet of things and cloud computing, users can instantly transmit a large amount of data to various fields, with the development of communication technology providing convenience for people's life, information security is becoming more and more important. Therefore, it is of great significance to study the technology of image hiding information detection. This paper mainly uses the support vector machine learning algorithm to detect the hidden information of the image, based on a standard image library, randomly selecting images for embedding secret information. According to the bit-plane correlation and the gradient energy change of a single bit-plane after encryption of an image LSB matching algorithm, gradient energy change is selected as characteristic change, and the gradient energy change is innovatively applied to a support vector machine classifier algorithm, and has very good detection effect and good stability on the dense image with the embedding rate of more than 40 percent.

Under rapid urbanization, cities are facing many societal challenges that impede sustainability. Big data analytics (BDA) gives cities unprecedented potential to address these issues. As BDA is still a new concept, there is limited knowledge on how to apply BDA in a sustainability context. Thus, this study investigates a case using BDA for sustainability, adopting the resource orchestration perspective. A process model is generated, which provides novel insights into three aspects: data resource orchestration, BDA capability development, and big data value creation. This study benefits both researchers and practitioners by contributing to theoretical developments as well as by providing practical insights.

Diabetic nephropathy (DN) is a common complication of diabetes. Yishen capsule, composed of Chinese herbs, improves the clinical outcome in DN patients. However, its therapeutic potential and underlying mechanisms require further elucidation. Hence, our study aimed to investigate the underlying mechanisms and therapeutic potential of Yishen capsule in DN. Streptozotocin-induced DN rats were treated with Yishen capsules (1.25 g/kg/day) for 8 weeks. Then, blood glucose and urine protein levels were measured. Hematoxylin and eosin staining and western blot assays were used to examine the histologic changes and gene expression, respectively, in kidney samples. Mouse podocytes were treated with rat serum containing Yishen capsule and transmission electron microscopy was used to examine autophagosome formation. Cell counting kit-8 assay was performed to examine cell proliferation. Western blot and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analyses were conducted to detect changes in gene expression. The localization of SIRT1 was examined in the podocytes using immunocytofluorescence assay. We found that Yishen capsule relieved pathological changes, decreased urine protein, increased SIRT1, LC3-II, and Beclin-1 expression, and reduced acetylated NF-κB p65 expression in vivo. In addition, rat serum containing Yishen capsule showed improved podocyte proliferation, promoted the mRNA and protein levels of LC3-II and Beclin-1, and induced nuclear translocation of SIRT1. Furthermore, it increased SIRT1 expression and decreased mRNA level of NF-κB in the serum. SIRT1 inhibitor increased the mRNA level of NF-κB. Our data suggests that Yishen capsule improves DN by promoting podocyte autophagy via the SIRT1/NF-κB pathway.

In a commercial fiber-based quantum key distribution (QKD) system, the state of polarization (SOP) of the optical fields is inevitably disturbed by random birefringence of the standard single-mode fiber due to an external complex environment. We analyze theoretically the effect of SOP fluctuations on the continuous-variable (CV) QKD system and experimentally verify its validity. To overcome the influence of the polarization variations, a self-adaptive gradient algorithm is proposed to achieve high-speed polarization controlling under pulsed light with field programmable gate array hardware. For single random polarization scrambling, the polarization extinction ratio achieved is over 30 dB and the average time of polarization control is 827 $\ensuremath{\mu}\mathrm{s}$. In order to eliminate further the effect of the occasional failures of polarization control, we properly filter the raw keys in terms of the relative phase fluctuations between the signal and the local oscillator. By combining this approach with the high-speed polarization control, we demonstrate a CV QKD under a continuous polarization scrambling of 314 rad/s. Our results provide useful references for practical application of fiber-based CV QKD in a field environment.

This paper proposes an artificial neural network (ANN)-based complex gain technique for digital predistortion (DPD) of power amplifiers (PAs). Existing look-up table (LUT)-based complex gain approach is one of the accurate DPD methods for PA linearization. However, this LUT-based approach consumes lots of memory and the linearization procedure is relatively slow due to the frequently search of the LUT. To address these issues, the proposed ANN-based complex gain technique uses ANN to learn the complicated relationships in the LUT and replaces the LUT with the trained ANN model, effectively minimizing the number of coefficients in the memory and avoiding indexing the LUT. The proposed technique decreases the memory requirement and speeds up the linearization procedure, while maintaining high linearization performance for PAs. The proposed technique is illustrated by two examples, i.e., a Freescale PA and a Doherty PA. The results show that the proposed technique has good linearization capability comparable to the existing LUT-based complex gain approach and can save data storage room as much as 99.65% in the Freescale PA example and 99.87% in the Doherty PA example.

Structural information of butyrylcholinesterase (BChE) and its variants associated with several diseases are discussed here. Pure human BChE has been proved safe and effective in treating organophosphorus (OPs) poisoning and has completed Phase 1 and 2 pharmacokinetic (PK) and safety studies. The introduction of specific mutations into native BChE to endow it a self-reactivating property has gained much progress in producing effective OPs hydrolases. The hydrolysis ability of native BChE on cocaine has been confirmed but was blocked to clinical application due to poor PK properties. Several BChE mutants with elevated cocaine hydrolysis activity were published, some of which have shown safety and efficiency in treating cocaine addiction of human. The increased level of BChE in progressed Alzheimer's disease patients made it a promising target to elevate acetylcholine level and attenuate cognitive status. A variety of selective BChE inhibitors with high inhibitory activity published in recent years are reviewed here. BChE could influence the weight and insulin secretion and resistance of BChE knockout (KO) mice through hydrolyzing ghrelin. The BChE-ghrelin pathway could also regulate aggressive behaviors of BChE-KO mice.

Recent studies suggested that Chotosan has ameliorative effects on vascular dementia through antioxidative pathways. Nevertheless, no systematic pharmacological research was conducted to evaluate the contribution of nuclear factor-E2-related factor 2 (Nrf2), a crucial regulator of antioxidative system, on Chotosan-induced neuroprotection invascular dementia. The present study aimed to investigate the neuroprotective effect of Chotosan on vascular dementia and reveal the possible molecular mechanism involving Nrf2. We found that Chotosan treatment could ameliorate memory impairment and reduce neuron cell loss induced by common carotid artery occlusion surgery. Furthermore, Chotosan could significantly reverse reactive oxygen species production, neuronal apoptosis and microglia over-activation in hippocampus. In addition, Chotosan enhanced Nrf2 expression and its nuclear translocation as well as its downstream antioxidant protein expression, NAD(P)H/quinone oxidoreductase 1 and heme oxygenase-1. These findings suggest that Chotosan exert neuroprotection in an animal model of vascular dementia via activating Nrf2-mediated antioxidant pathway. Chotosan may serve as a potential candidate and promising Nrf2 activator for treating vascular dementia. Keywords: Chotosan, Vascular dementia, Nrf2, Oxidative stress, Cognitive deficits

Ethnopharmacological relevance Periploca forrestii Schltr. was listed as a classical medicinal plant in “Miao medicine”, which is a branch of traditional Chinese medicine (TCM). According to the theory of TCM, P. forrestii has the efficacy of relaxing tendons and activating collaterals, and dispelling wind and eliminating dampness. Hence, it was often used for the therapy of rheumatoid arthritis and traumatic injury in clinical practice. Aims of the review This review aims to present comprehensive information for the research progress of P. forrestii. The researches on botany, traditional uses, phytochemistry, pharmacology and toxicology of the plant are summarized. We mainly focus on the phytochemical and pharmacological investigations. As a representative class of phytochemicals in P. forrestii, more attention is paid to cardiac glycosides. The insights into potential action of mechanisms and possible future studies on P. forrestii are also discussed. Materials and methods Relevant literature was acquired from scientific databases including Google Scholar, Web of Science, Scifinder, Baidu Scholar, PubMed and Chinese national knowledge infrastructure. Monographs and Chinese pharmacopoeia were also utilized as references. Results To date, all kinds of phytochemical constituents have been isolated and identified from this plant including cardiac glycosides, steroids, terpenoids, flavonoids, phenylpropanoids, quinones, organic phenolic acids and others. Among these, cardiac glycosides were considered as the major ingredients and bioactive materials. Modern pharmacological studies demonstrated that the plant possessed extensive bioactivity, such as anti-inflammatory and analgesic effects, immunosuppressive action, wound healing activity, antioxidant, anti-tumor and, cardiotonic properties. Conclusions As an important medicinal plant, lots of studies have proved that P. forrestii has significant therapeutical effects, especially on rheumatoid arthritis and traumatic injury. These results provide modern scientific evidence for traditional use and contribute to the development of novel remedies for chronic diseases. However, the exact mechanism of action remains to be elucidated. Furthermore, the long-term in vivo toxicity and clinical efficacy also require in-depth exploration in the future.

The indoor subarea localization is of great significance in the application of dynamic hot-zone identification, indoor layout optimization, store dynamic pricing and crowd flow trend prediction. The ubiquitous mobile devices provide the opportunity for wireless fingerprinting-based indoor localization services. However, there are two places where the existing methods have been criticized. One is a tagging approach that requires a large number of professional surveys, with too much overhead wireless fingerprint construction and the weakened system scalability. The other is the crowdsourcing fingerprint-based methods meet the cold start problem in the initial stage of the operation. To attack these problems, the paper proposes a topology optimization approach with dynamic logical anchor selection for a subarea localization system. First of all, taking advantage of the feedback selection of logic anchor, a new annular-based radio map construction strategy is presented. The implementation of this strategy harnesses the characteristics of the indoor building structure and inter-subarea overlapping recognition, without depending on the topology and distribution of physical anchor (e.g., Access points or POIs). Secondly, exploiting the probabilistic support vector machine algorithm, the target is localized in the corresponding subarea in real-time pattern. Furthermore, the localization error is used to calibrate the localization result with an error recognition algorithm. Finally, massive experiments and simulations are implemented on a prototype system. The results show that the proposed method can decrease the human effort and computing cost and achieve higher localization accuracy compared with the existing approaches.

As a universal interaction method, hand and finger gestures can express people’s intention directly and clearly in daily life, and has been one of the hotspots in human–computer interaction community. In this paper, we present DMT, a device-free finger gesture tracking system that can track and recognize the finger motion accurately. To achieve this, we transform the mobile device, such as a smart phone, into an active sonar system by establishing inaudible audio links between the built-in speakers and microphone. The finger motion will have an effect (e.g., Doppler-shift) on the audio signals, which makes it possible to track the finger motion according to the received signal characteristics at the microphone side. Due to the small reflection energy and slow moving speed of the finger, the existing methods cannot detect the Doppler-shift accurately. To this end, a Fourier fitting-based method is proposed in the DMT to accurately detect the Doppler-shift. With the detected Doppler-shift, the DMT can track the finger motion with high accuracy. The DMT supports all kinds of finger gestures interaction, including characters and shapes. Extensive experiments demonstrate the high accuracy and robustness of the DMT in dynamic environments.

Point-of-interest (POI) recommendations can help users effectively explore new locations according to their preferences, which is an important research aspect for location-based social networks (LBSNs). However, most existing POI recommendation methods lack adaptability when making recommendations for users with different preferences, which causes unsatisfactory recommendation results. To this end, in this paper, we propose an adaptive POI recommendation method by combining user activity and spatial features, which can operate adaptively according to user activity. First, we extract three-dimensional user activity, time-based POI popularity and distance features using a probabilistic statistical analysis method from historical check-in datasets on LBSNs. Second, we devise a user activity clustering algorithm that is based on fuzzy c-means and compute POI popularity by applying smoothing technology to adjacent continuous time slots. Finally, we propose an adaptive recommendation scheme, which includes a two-dimensional Gaussian kernel density estimation algorithm and a one-dimensional power-law function algorithm with POI popularity according to user activity. Extensive experiments on Foursquare and Gowalla datasets show that the proposed method outperforms the baseline methods in terms of both precision and recall.

Hydrate generation and pipe blockage in long-distance natural gas transmission pipelines has always been a major issue affecting the transmission safety. Although considerable progress have been made in recent years, there is still a long way to go in the study of the hydrates generation and plugging prediction in the gas pipelines. Hydrate plugging and accumulation is a gradual process. However, the previous studies have focused only on the prediction of whether hydrates are formed. Actually, the research on hydrate formation rate and pipelines blockage degree at different times is also important for the hydrate prevention and control. In this work, the authors proposed a novel risk assessment method for hydrate blockage in long-distance natural gas transmission pipelines. Firstly, considering the hydrate formation process, a new model consist of mass, momentum and energy balance equations was established. Secondly, the model results are solved by the iterative method and finite difference method. After comparison, the calculation results and the field data are in good agreement. Finally, the sensitivity analysis were performed on the important parameters of our model. According to the sensitivity analysis, transmission rate, inlet temperature, and natural gas dew point temperature have different effects on the hydrate generation, the location of the largest plugging point, and the degree of blockage. Meanwhile, considering the actual gas transmission process and the hydrate plugging characteristics, the proposed hydrate prevention and control measures can be taken to achieve safe and efficient natural gas transmission.

The injection of supercritical CO2 coupled with superheated steam (SHS) for heavy oil recovery can improve development efficiency. In order to help oil fields to improve the efficiency of CO2 and SHS utilization we must predict the thermophysical properties at well bottom. Based on the mass, energy, and momentum conservation equations, a non‐isothermal pipe‐flow model is established considering heat exchange between the integral joint tubing (IJT) and annuli. Coupled with the transient thermal conduction model in stratum and the S‐R‐K real gas model, a comprehensive model is established for the mixture flow in concentric dual‐tubing wells (CDTW). The model is solved by a numerical method and an iteration technique. The results show that: (a) the accuracy of the temperature profile calculation has been greatly improved compared with the previous model; (b) the heat‐carrying capacity per unit mass of the mixture and heating efficiency decrease with increasing supercritical CO2 content; (c) when a temperature difference exists between the IJT and annuli, a rapid flow of thermal energy exists inside the CDTW, which causes a significant temperature change near the wellbore, but the influence of temperature change on pressure profiles is negligible. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.

The Epstein-Barr virus (EBV) infects more than 95% of adults worldwide and is associated with various malignant tumors and immune diseases, imparting a huge disease burden on the human population. Available EBV vaccines are imminent. Prophylactic vaccines can effectively prevent the spread of infection, whereas therapeutic vaccines mainly stimulate cell-mediated immunity and kill infected cells, thus curbing the development of malignant tumors. Nevertheless, there are still no approved EBV vaccines after decades of effort. The complexity of the EBV life cycle, the lack of appropriate animal models, and the limited reports on adjuvant selection and immune responses are gravely impeding progress in EBV vaccines. The soluble gp350 vaccine could reduce the incidence of infectious mononucleosis (IM), which seemed to offer hope, but could not prevent EBV infection. Continuous research and vaccine trials provide deep insights into the structural biology of viruses, the designs for immunogenicity, and the evolving vaccine platforms. Moreover, the new vaccine candidates are expected to achieve further success via combined immunization to elicit both a dual protection of B cells and epithelial cells, and sustainable immunization against infected cells at several phases of infection.

Ethnopharmacological relevance Jiao Sanxian, a customary term for the three Traditional Chinese Medicines of charred hawthorn (Crataegi Fructus), charred malt (Hordei Fructus Germinatus) and Liu Shenqu (Massa Medicata Fermentata), is a classic prescription for the treatment of functional dyspepsia (FD). This prescription is called “Jiao Sanxian” in China because people believe that it is a miracle medicine for enhancing digestion and improving stagnation of digestive system. Even though Jiao Sanxian is widely used in clinical treatment, the underlying mechanism has not been clarified to date. Aim of the study The present study is aimed to explore the efficacy and mechanism of Jiao Sanxian in improving the symptoms of FD in rats by using multiple pharmacological methods. Materials and methods The Sprague Dawley (SD) rats were divided into control, model, Jiao Sanxian decoction low-dosage (JSXD LD), Jiao Sanxian decoction medium-dosage (JSXD MD), and Jiao Sanxian decoction high-dosage (JSXD HD) group at random. A FD model was established with reserpine, and animals were given intragastric administration. During this period, weight and food intake of animals were recorded. Samples of rat gastric antrum, spleen, and duodenum were collected for pathological staining and immunohistochemical determination of Ghrelin protein expression after 19 days of treatment. Enzyme-linked immunosorbent assay (ELISA) was used to determine the concentration of related brain gut peptides in serum. Moreover, 16S rRNA sequencing was used to valuate the influence of intestinal flora structure of the cecal contents of experimental rats. And plasma metabolomics by Ultra Performance Liquid Chromatography coupled with Quadrupole-Time-of-Flight mass spectrometry (UPLC-Q/TOF-MS) were performed to further reveal the mechanism of action. Results Jiao Sanxian decoction (JSXD) group with different dosage could increase body weight and food intake, improve histopathological changes, and alter disordered brain gut peptides in FD rats. 16S rRNA sequencing results described that JSXD improved the disorder of structural composition, biodiversity and function of gut microbiota in FD rats. Metabolomics illustrated 26 metabolites with JSXD treatment underwent continuous changes, which revealed JSXD might exert digestive effect by ameliorating abnormal metabolic pathways. The most relevant metabolic pathways were arachidonic acid metabolism, pyruvate metabolism, glycerophospholipid metabolism, alanine, aspartate and glutamate metabolism. Conclusions JSXD can improve functional dyspepsia in rats and the mechanism is related to regulate secretion of brain gut peptides, significantly improve the disorder of intestinal flora and ameliorated multi-metabolic pathways.

Dielectric ceramic materials with high power density and fast charge–discharge speed have attracted increasing attention in recent years. However, their mutually restricted energy density and efficiency as well as unsatisfactory temperature stability have been the main obstacles for their practical applications. Herein, a high recoverable energy density of 5.02 J·cm−3 and a high efficiency of ~ 90% can be obtained under 422 kV·cm−1 in the Sr0.85Sm0.1TiO3 (SST)-modified Na0.5Bi0.5TiO3 (NBT) ceramics via composition design and domain engineering strategy, and the excellent stability of energy storage properties in frequency (1–100 Hz) and temperature (20–180 °C) were also observed at 250 kV·cm−1 in the 0.50NBT-0.50SST ceramics, which are attributed to the improved breakdown strength (Eb) and the enhanced relaxation behavior. The increased band gap width and refined grain size are responsible for the significantly enhanced Eb of Na0.5Bi0.5TiO3-based solid solution, being confirmed by ultraviolet and visible (UV–vis) absorption spectra as well as scanning electron microscopy. The generation of polar nanoregions as demonstrated by piezoresponse force microscopy and transmission electron microscopy results in a negligible remanent polarization and thermally stable polarization-field response. It is worth noting that the energy density will be further greatly optimized due to the improvement of Eb if this ceramic composite is made into multilayer ceramic capacitor as a dielectric layer. Moreover, a large power density of 188.6 MW·cm−3 and a fast discharge speed of 70 ns can also be achieved in the optimized composition. The results show that the multi-scale optimization strategy is an effective way to realize excellent comprehensive energy storage performances in the Na0.5Bi0.5TiO3 based ceramics.

This paper compares the customers’ balking behavior in site-clearing and non-site-clearing Markovian queues with server failures and unreliable repairer. That is, the system is subject to failures ...

The mechanical behavior of all-welded beam-column connections of steel frames during progressive collapse was numerically studied using finite element simulations. The validation of the numerical model was based on a previous test model. The analysis results indicated that the stiffness of the all-welded beam-column connection in the elastic-plastic stage was mainly provided by the shear stiffness of the panel zone, and the axial compression on the column had a substantial impact on the capacity and ductility of the all-welded beam-column connection. An improved component-based model of the all-welded beam-column connection was proposed. To verify the accuracy of the proposed model, a beam-column assembly with an all-welded connection was established and the influence of the catenary action, column axial compression, beam-column stiffness ratio, and dynamic performance was parametrically analyzed. The validation results showed that the proposed model was able to simulate the behavior of all-welded beam-column connections at large structural deformation.

This article examines Meilong animal husbandry cooperatives in the Haixi Prefecture of Qinghai Province, China as a study case, using information gathered through field surveys and questionnaires to explore the systemic structure and operational mechanisms of Meilong Cooperatives, as well as its impacts on pastoral areas and herdsmen. Based on the results, the main contribution of the Meilong Model is providing a new way for pastoral villages to pursue development through joint-stock cooperatives, and thus represents the long-term direction of pastoral area development. This model reforms the traditional cooperative concept that naturally arises among herdsmen; Meilong Share-holding Cooperative guarantees the equal rights of small or poor households to participate in the management of cooperatives on the basis of “one household, one vote”, rather than the principle of “shareholders have the right to manage, vote and speak according to the proportion of shareholding” found in the joint-stock systems of modern enterprises. It localizes the shareholding system theory to be more acceptable and feasible in order to ensure the survival of animal husbandry cooperatives.

Hydrates generation-blockage in submarine natural gas pipelines has always been related to the safety of deepwater natural gas production and transportation. However, the current hydrate formation risk prediction in subsea pipelines is still immature. In this paper, a model for evaluating the risk of hydrate formation in submarine natural gas pipelines has been established. The model has been applied and the sensitivity analysis of typical factors has been carried out. The results show that: (a) owing to the low temperature of the seabed, hydrate formation region (HFR) often exists in submarine pipelines. Avoiding HFR by injecting inhibitors is the key to ensure the safe transmission. (b) the decrease of gas temperature in the pipeline is determined by the heat loss of gas from inside to outside of the pipe. At a lower gas transport rate, the decrease of gas temperature is more significantly affected by the heat exchange rate. (c) at the same gas transport pressure and temperature, the pressure drop increases with the increase of gas transmission rate, while the temperature drop and the length of HFR decrease with the increase of gas transmission rate. (d) at the same gas transport rate and pressure, the pressure drop in the submarine pipeline is not significantly affected by the gas transport temperature, but the gas temperature at the end of the pipeline increases with the increase of the gas transport temperature and and the length of HFR decreases with the increase of gas transport temperature. (e) at the same gas transport rate and temperature, the temperature drop and HFR in the submarine pipeline is not significantly affected by the gas transport pressure, but the pressure drop loss decreases gradually with the increase of gas transport pressure. (f) reasonable setting of gas transport temperature and gas transport rate can help to reduce the hydrate risk and consumption of inhibitors in the submarine natural gas transportation. Accurate prediction of hydrate risk in deepwater submarine pipelines is essential for safe gas transportation. The research provides the theoretical guidance for safe and efficient natural gas resources development and transportation.

Taking section 3600 of Pingzhuangxi coal mine as the prototype, we made the test model based on the theory of similarity, used the fiber Bragg grating (FBG) to study the deformation characteristics of overburden in the process of coal seam backfill mining and analyze the correlation between filling material and overburden settlement, and obtained the deformation law of overburden in the seam filling area and the coal pillar area. The results show that due to the impact of compression characteristics of filling materials, the intermediate roof, and the breakage of key strata, the overburden deformation in the seam filling area can be divided into 4 stages, and the coal pillar overburden deformation can be divided into 3 stages according to the slope of strain distribution curve of overburden during backfill mining. Based on the slope of the strain curve of mining overburden and the strain value measured by FBG sensors, this paper identified the stability of rock stratum, proposed a FBG-based method to determine the height of the water-flowing fractured zone, compared it with the existing calculation methods to verify its rationality, and came to a conclusion that this new method can be promoted for future calculation.

Dielectric ceramics are highly favorable for pulsed power applications owing to their ultra-fast charge-discharge speed and excellent reliability. However, their low energy density under low electric fields remains as a bottleneck for them to be employed in integrated electronic devices with shrinking dimensions. In this work, we have designed a comprehensive strategy to synthesize lead-free (Bi1/2Na1/2)1−xSrxTi0.98(Fe1/2Nb1/2)0.02O3 (BNT-xST-2FN, x = 0.30, 0.35, 0.40 and 0.45) ceramics via traditional solid-state method. On one hand, the hybridizations of Bi3+ orbitals and the displacement of B-site cations under the applied electric field lead to a high polarization. On the other hand, the (Fe1/2Nb1/2)4+ complex-ion and SrTiO3 were introduced to improve the relaxor behavior of the system, resulting in a high energy-storage efficiency. In this way, an excellent energy density of 3.36 J/cm3 and a high energy efficiency of 81% are simultaneously achieved in the BNT-0.40ST-0.02FN composition under a low electric field of 170 kV/cm, which is superior to other BNT-based materials under similar electric fields. Moreover, the ceramic exhibits a superior thermal stability (25–200 °C). This work provides a promising approach for designing high-performance lead-free energy storage ceramics under low electric fields.

Ethnopharmacological relevance Recently, the focus on neuroinflammation is intensified as its complex pathophysiological role has emerged in multiple central nervous system(CNS) disorders. Chotosan (CTS), known as a traditional herbal formula, is often utilized to treat relevant nervous system diseases in China. It was demonstrated effectively to alleviate cognitive deficit associated with aging, diabetes, hypoperfusion and cerebral ischemia. However, the effects of CTS on Aβ1–42-induced cognitive dysfunction remain unclear. Here, we further investigated the effects of chotosan on memory performance, neuroinflammation and apoptotic responses. Materials and methods The learning and memory ability is evaluated by Morris water maze (MWM) task and Y-maze test following intrahippocampal infusion of aggregated Aβ1–42. The expression level of toll-like receptor 4 (TLR-4), NF-κB p65, Bcl-2 and Bax was examined by Western blot. TLR-4 level is also assessed by immunohistochemistry (IHC). Enzyme-linked immunosorbent assay (ELISA) was conducted to determine the generation of inflammatory mediators. The caspase-3 activity is analyzed by commercial kits. Results The repeated treatment with CTS (750 mg/kg or 375 mg/kg per day) for 3 weeks significantly restored Aβ1–42-induced memory impairment in mice. Meanwhile, this treatment also remarkably reduced TLR-4 and NF-κB p65 expression accompanying with the diminished release of proinflammatory cytokines including TNF-α and IL-1β in hippocampus. The neuronal apoptosis is also inhibited as evidenced by increase in Bcl-2/Bax ratio and decrease in pro-apoptotic protein caspase-3 activity compared to that of the model mice. Conclusions Our results show for the first time that chotosan can ameliorate Aβ1–2-induced memory dysfunction via inhibiting neuroinflammation and apoptosis at least partially mediated by TLR-4/NF-κB signaling pathway.

Background Non-typhoidal Salmonella (NTS), a common cause of diarrheal enterocolitis, may also cause severe invasive diseases. Limited information on NTS infections in children is available in China. Methods We performed a retrospective study of children admitted to the Ningbo Women and Children’s Hospital with culture-confirmed NTS infections between January 2012 and December 2019. Clinical and microbiological information were collected. We compared demographic, clinical and antibiotic resistance variables of invasive NTS (iNTS) infections and non-invasive NTS (non-iNTS) infections, and explored associations between hospitalizations for pediatric NTS infections and temperature and rainfall. Results A total of 166 pediatric hospitalizations due to NTS infection were identified during the 8-year study period. Most of the 166 children were, Author summary Non-typhoidal Salmonella (NTS) infection is a foodborne disease with a global heavy burden. NTS usually causes diarrheal enterocolitis in humans and may also cause severe invasive NTS (iNTS) infections. Antimicrobial agents are not recommended for non-severe NTS diarrhea, but they are recommended for people at risk of severe or invasive infection. However, the recognition of iNTS infection among children is difficult before culture. We studied children who had NTS infections in a tertiary pediatric hospital in Ningbo and found that iNTS infections were more likely to occur in infants ≤6 months or children with an underlying medical condition of leukemia at admission, while diarrhea was more common in children with non-iNTS infections. The high rates of antibiotic resistance among children with NTS in Ningbo calls for continuous NTS surveillance. On the other hand, high temperatures and heavy rainfall were positively associated with NTS hospitalizations among children. These findings may help us to improve measures for the prevention, diagnosis and treatment of NTS infections among children.

This study investigates how Big Data Analytics (BDA) can be leveraged to support a city’s transformation into a smart destination. We conduct an in-depth case study of a city-in-transformation and adopt the perspective of technology affordances to uncover the varying opportunities enabled by BDA to facilitate the attainment of smart tourism goals. Our findings unveil three types of BDA affordances and demonstrate how these affordances are actualized in a cascading manner to enable informed decisions and a sustainable development of smart tourism. Implications are presented for future investigation of the affordances of BDA in smart tourism, as well as for policy makers and practitioners who engage in the development of innovative tourism services for the smart citizens.

In order to explore the application of computer information health monitoring technology in the evaluation of the treatment effect after total parathyroidectomy (T-PTX) for patients with Secondary Hyperparathyroidism (SHPT), preoperative magnetic resonance imaging (MRI) computer health monitoring technology was used to locate and diagnose the parathyroid glands. Autotransplantation were performed. The changes of total intact parathyroid hormone (iPTH) before and after surgery, serum Calcium (Ca), serum phosphorus (P), and alkaline phosphatase (ALP) were observed and recorded. The postoperative complications were observed. The postoperative recurrent laryngeal nerve injury was analyzed. The results showed that serum Ca, serum P, and iPTH of the patients were significantly decreased within 6 months after parathyroid gland resection compared with that before surgery (P 0.05); however, there was no significant change in ALP level within one week after surgery (P 0.05); after surgical treatment, the clinical symptoms of patients with bone pain, itchy skin, and restless leg syndrome were significantly decreased, and 2 cases of recurrent laryngeal nerve injury, and 1 case of new arrhythmia, with a complication rate of 7.14 %, which showed that MRI based on computer information technology had a good value in preoperative localization and diagnosis of the parathyroid gland in SHPT patients and lower the rate of postoperative infection and complications and the impairment of recurrent laryngeal nerve function.