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Bio-inspired soft grippers based on impactive gripping with the advantages of flexibility and universality have been widely used in take-and-place tasks. However, this type of gripper has the risk of breaking fragile objects with deformable surfaces due to the inevitable impactive force applied to the objects. Inspired by the grasping method of human fingers, this article presents a gripper containing two shape-locking fingers that can simultaneously control the span and grasping force to reduce the impact and grasp fragile objects safely. The shape-locking finger composes of three parts, including a soft pneumatic actuator, a folding laminar jamming structure, and a typical laminar jamming structure and the function of the three parts are driving, locking the shape, and improving the stiffness of the finger, respectively. In addition, combined with finite element analysis, we establish a theoretical model to predict the finger's bending angle and tip force, and the experimental results demonstrate the reliability of the model. Through a specific grasping process: pregrasp, shape-locking, and improving the grasping force, the controllable span and force (CSF) gripper can safely grasp deformable objects, such as a plastic cup with a 100-g weight, tofu, cake, mochi, and jelly, which shows that the CSF gripper has the potential for fragile foods tasks.

A TMSCN-promoted difunctionalization of styrenes with CHCl3and TBHP is reported via the radical addition/cross coupling process. A wide range of dichloromethyl-substituted alcohol derivatives were synthesized under transition-metal-free conditions. Besides, this method is also applicable to unactive alkenes. The key to this success lies in the role of TMSCN, which prevents the reaction toward dichloromethylperoxylation of olefins. This represents an alternative approach for synthesizing diverse alcohol derivatives using readily available substrates, holding significant promise in the fields of pharmaceutical chemistry and natural product synthesis.

• Near fully dense samples with porosity less than 0.1 % are obtained in the L-PBF TiN reinforced Al–Mn–Mg–Sc–Zr alloy. • Ultrahigh tensile yield strength over 580 MPa is achieved at the as-built tin/Al–Mn–Mg–Sc–Zr composite. • The addition of TiN nanoparticles effectively promotes the columnar-to-equiaxed grains transition and the composite samples show ultrafine microstructure. • The strengthening mechanisms is mainly attributed to the ultrafine grains, ultimate solid solution of alloying elements, and the high volume density of Al 3 (Ti,Sc,Zr) nanoprecipitates. In this work, a high-strength crack-free TiN/Al–Mn–Mg–Sc–Zr composite was fabricated by laser powder bed fusion (L-PBF). A large amount of uniformly distributed L1 2 -Al 3 (Ti, Sc, Zr) nanoparticles were formed during the L-PBF process due to the partial melting and decomposition of TiN nanoparticles under a high temperature. These L1 2 –Al 3 (Ti, Sc, Zr) nanoparticles exhibited a highly coherent lattice relationship with the Al matrix. All the prepared TiN/Al–Mn–Mg–Sc–Zr composite samples exhibit ultrafine grain microstructure. In addition, the as-built composite containing 1.5 wt% TiN shows an excellent tensile property with a yield strength of over 580 MPa and an elongation of over 8 %, which were much higher than those of wrought 7xxx alloys. The effects of various strengthening mechanisms were quantitatively estimated and the high strength of the alloy was mainly attributed to the refined microstructure, solid solution strengthening, and precipitation strengthening contributed by L1 2 –Al 3 (Ti, Sc, Zr) nanoparticles. The L-PBF TiN/Al–Mn–Mg–Sc–Zr composites show an ultra-fine microstructure owing to the heterogeneous nucleation effect of L1 2 –Al3(Ti, Sc, Zr) nanoparticles. The L1 2 –Al3(Ti, Sc, Zr) nanoparticles exhibit coherent relationship with Al matrix and enhance precipitation strengthening, resulting in a high yield strength of 583 ± 4 MPa in the 1.5 wt% TiN/Al–Mn–Mg–Sc–Zr composite. [Display omitted] [ABSTRACT FROM AUTHOR]

In this work, the various amount of Nb powder was mechanically mixed into the Cu–Al–Mn shape memory alloys (SMAs) to prepare quaternary SMAs by laser powder bed fusion (LPBF). Altered microstructure, transformation behaviour of alloys and its underlying mechanisms were analyzed. Corresponding shape memory effect (SME) was also studied. Result shows that Nb content has significant effect on the microstructure, phase transition temperatures (TTs) and SME. The microstructure of the alloy was refined by addition of appropriate Nb content. The formation of precipitates and massive grain boundaries after the addition of Nb caused a reduction of TTs and wide thermal hysteresis. Sample with 1 at%Nb containing fine and small volume fraction precipitate shows the best available strain.

An efficient and convenient method for the synthesis of oxalamides by the reaction of β-ketoamides with tertiary amines and TBHP was developed. A variety of β-ketoamides and tertiary amines substrates were well-tolerated in this transformation. Based on the control experiments, a plausible mechanism for this reaction was proposed that involved the tandem oxidation/amination process. In addition, α,β-epoxy amides could be obtained by adjusting the reaction conditions.

The interaction of PD-L1 and PD-1 transmits the inhibitory signal to reduce the proliferation of antigen-specific T-cells in lymph nodes. The expression of PD-L1 confers a potential escaping mechanism of tumors from the host immune system. Blocking the interaction of PD-1 and PD-L1 enables tumor-reactive T cells to overcome regulatory mechanisms and induce an effective antitumor response. The hydrophobic tag tethering degrader (HyTTD) contains a hydrophobic moiety, binding to the protein of interest (POI) to mimic the misfolding state of the POI, thereby inducing the degradation of POI. In this work, using the HyTTD strategy, we selected the diphenylmethyl derivatives as the PD-L1 binding motif for PD-L1 to develop the degraders for PD-L1, and multiple hydrophobic tags were attached. As a result, two HyTTDs Z2dand Z3defficiently decreased the protein level of PD-L1 in both NCI-H460 and HT-1080 cells with low cytotoxicity. Meanwhile, the reduction of PD-L1 protein levels by Z2d/Z3dwas counteracted by MG132, which indicated that Z2d/Z3ddegraded PD-L1 through the proteasome pathway. Moreover, the molecular modeling results indicated that the HyT group of Z2dor Z3dextended the surface of the protein to mimic the misfold. Importantly, our work also identified a novel HyT, which could be applied to develop the HyTTD for other target proteins.

To address the universal challenge that the mirror coefficient (MC) cannot be analytically expressed, the joint analytical calculation (JAC) method is initially proposed in this article. Selecting the magnetic vector potential (MVP) as a uniform analytical target, the JAC method constructs a bridge, linking the truncated region eigenfunction expansion (TREE) method and the mirror method. Furthermore, an analytical expression of MC is derived based on the uniqueness principle of the magnetic field. The JAC method comprehensively reflects the effect of magnetic medium parameters, coil parameters, and field point coordinates on MC. Furthermore, the double TREE method is proposed to further improve the analytical accuracy of MVP. The experiment indicates that the analytical error of MVP is shrunk by a maximum of 3.16%. Then, magnetic flux density (MFD) is solved according to the analytical expressions of MC. The experiment shows that the JAC method and the mirror method have a maximum error of 4.08% and 27.99% for calculating MFD, respectively.

In this letter, both the suppression methods of the common-mode (CM) and differential-mode (DM) interferences are proposed in a high-power simultaneous wireless and data power transfer system. The split compensation inductors and capacitors provide the CM current path with the help of the additional Y capacitors, and the high-frequency CM interference to the data channel at the switching instant is effectively suppressed. In addition, the coupling coil multiplexed for power and data transfer is segmentally compensated by the distribution compensation of the series compensation capacitors, reducing the DM interference voltage of the power carrier significantly. Thus, high-quality data can be received when transferring high power. A 3.3-kW experimental prototype with a data transfer rate of 115.2 kbps is designed to verify the effectiveness of the proposed interference suppression method.

Colorectal cancer (CRC) is a prevalent malignancy with high incidence and low 5-year survival. Long non-coding RNAs (lncRNAs), a kind of specific RNA transcript, are increasingly implicated in tumor growth, metastasis, invasion, and prognosis by regulating the tumor microenvironment in extracellular vesicles (EVs). This study aims at investigating the potential effect of lncRNA HLA-F-AS1 on CRC by affecting the profilin 1 (PFN1) expression pattern in the tumor EVs. The expression patterns of HLA-F-AS1 and miR-375 were determined by RT-qPCR in the CRC tissues and cells. CCK-8 and Transwell assays were conducted to detect the cell proliferation and migration, and invasion, respectively. Western blot analysis was performed to measure the expression pattern of the epithelial–mesenchymal transition (EMT) markers. Bioinformatics prediction website and dual-luciferase reporter assay were conducted to verify the interaction between HLA-F-AS1 and miR-375. The CRC-derived EVs were extracted with the expression pattern of PFN1 determined by ELISA, while its effect on the macrophage polarization was assessed by flow cytometry. The effect of PFN1-treated macrophages on CRC cell proliferation and migration was observed by subcutaneous tumorigenesis experiments in nude mice. The results indicated that the HLA-F-AS1 expression pattern was increased in the CRC tissues and cells, which promoted the migration, invasion, and EMT of CRC cells in vitro. Mechanistically, HLA-F-AS1 competitively bound to miR-375 and inversely regulated miR-375 expression pattern. Interestingly, PFN1 was identified as a direct target of miR-375, and positively modulated by HLA-F-AS1 by binding to miR-375. Overexpression of HLA-F-AS1 repressed miR-375 and promoted the PFN1 expression pattern in CRC cells and CRC-derived EVs, further promoting M2 polarization of macrophages. Furthermore, macrophages treated with PFN1 in CRC-derived EVs stimulated CRC cell proliferation and migration in vitro and in vivo. Collectively, these outcomes highlight that HLA-F-AS1 promotes the expression pattern of PFN1 in CRC-EVs by inhibiting miR-375, thereby polarizing macrophages toward M2 phenotype, and aggravating the tumorigenesis of CRC, eliciting that HLA-F-AS1 may serve as a viable and promising therapeutic strategy for CRC.

Magnetic coupling resonance wireless power transfer technology is one of the effective ways to solve the energy supply problem of autonomous underwater vehicles. As the most critical component in an underwater wireless power transfer system, the magnetic coupler largely determines the energy transfer capability and marine environment adaptability. This article proposes a novel ID-shaped magnetic coupler with a pendulum-type receiver, which has characteristics of compact structure, lightweight, enough misalignment tolerance, and high receiver power density. The design and optimization flow of the magnetic is given in detail in this article, and an experimental prototype is constructed to verify the proposal. The receiver weighs only 746 g, yet it can deliver over 3 kW at 95.985% dc–dc efficiency when fully aligned. Especially the proposal achieves stable output in the range of rotational and axial misalignment of [−30 mm, 30 mm], with a system efficiency consistently above 95% and efficiency fluctuations below 1%.

In this letter, an LCCC-LCC compensated dual-coupled wireless power transfer system is proposed to enhance the mutual inductance (MI) and antimisalignment capability. Only one capacitor is added to the LCC-compensated primary side. Not only the similar transfer characteristic to that of the LCC-LCC compensated system, like the load independent constant current output with zero phase angle (ZPA), but also the enhanced stable equivalent MI can be flexibly designed by introducing the MI adjustment factor λ. Thus, a stable output is efficiently offered. A 3.3-kW experimental prototype with Al plate is designed for validation. The result shows that the fluctuation of the load current is 5% within the 120 mm misalignment and the dc–dc efficiency of the system can be maintained above 90%.

Misalignment tolerance ability and vertical distance adaptation are equally vital for both the power transfer and the data exchange in simultaneous wireless power and data transfer (SWPDT) systems. The coupling mechanism with the anti-series coil is explored in detail, and it is proven that not only the misalignment tolerance but also the vertical distance adaptation can be significantly improved with the well design parameter. Data is injected into the anti-series coil and extracted from the partial receiving coil. The data transfer link is analyzed, and the anti-series coil and the number of turns of the inside receiving coil are designed to stabilize the mutual inductance. Moreover, the method of distribution compensation capacitors is proposed to suppress the power interference and reduce the voltage stress of capacitors and coils. The 868-W prototype is constructed for validation. The result shows that the load current is maintained constant well within the 100 mm misalignment distance, and dc–dc efficiency is 85.12%. Also, the transferred data is correctly recovered at the rate of 115.2 kb/s in the given displacements.

Mechanical and corrosion behaviors perpendicular to build direction (XOY) and along build direction (XOZ) of UNS S31803 duplex stainless steel (DSS) fabricated by laser powder bed fusion (LPBF) were investigated. With the post-annealing, the steel exhibited a ferrite-austenite microstructure. For XOY plane, austenite displayed a primarily <101> texture while ferrite kept <001> preferred orientation, and mainly held a Nishiyama-Wassermann orientation relationship. However, for XOZ plane, austenite showed a mixed texture. The average size of ferrite grains was larger for XOZ plane than XOY. The austenite in XOY plane was mostly island morphology grains, while in XOZ plane, there were a large number of coarse columnar grains. A higher geometrically necessary dislocation density and proportion of low-angle grain boundaries on XOY plane were observed. The yield strength and ultimate tensile strength values perpendicular to build direction were higher than those along build direction. While the total elongation perpendicular to build direction was lower. Moreover, the XOY plane shows slightly better corrosion resistance than the XOZ.

ABSTRACTPine wilt disease (PWD) is one of the most destructive forest diseases in the world. Therefore, timely monitoring of PWD is essential to the preservation of the ecological environment. However, the complex topography of PWD-outbreak locations affords many limitations in the manual detection of the disease. The use of unmanned aerial vehicles (UAVs) and deep learning technology to detect PWD-infected trees has gained popularity in recent years. In this study, we configured the You Only Look Once version 3 (YOLOv3) model according to the characteristics of the three disease stages of PWD and proposed an improved model called Effi_YOLO_v3. The results revealed that the improved model achieved good detection performance. The proposed model yielded a mean average precision (mAP) of 94.39%, and the classification of the different infection stages was relatively accurate. The recall values for the classifications of trees in the early-infection, late-infection, and death stages were 89.15%, 86.13%, and 86.77%, respectively. This indicates that the model offers good applicability in detecting different stages of PWD in trees.

Diet is fundamental to maintaining and improving human health. There is ample evidence identifying the beneficial and/or harmful effects of diet on noncommunicable diseases such as obesity, diabetes mellitus, and cardiovascular disease. However, the associations of the diet to chronic venous disease has not been fully described.

Origami technology has applications in diverse areas, such as metamaterials, space structures, and haptic interfaces due to the low-cost manufacturing, rapid assembly, and compact structures. Existing origami robots, however, often lack variable stiffness due to the intrinsic properties of conventional origami structures made of rigid facets and flexible joints. In this article, we present a design of magnetorheological (MR) fluid-filled origami joints with variable stiffness characteristics. Compared with existing approaches to realize controllable origami joints stiffness, our proposed method has the advantage of magnetically remote control. To predict the joint stiffness under different magnetic flux densities, we derive a theoretical model and calibrate it by test. Subsequently, to demonstrate MR fluid-filled origami joints can apply in more complex origami structures, we design a modified thick Yoshimura structure and a Kresling structure that can achieve stiffness enhancement of 59.2 and 83.6%, respectively. Also, we introduce jamming behavior into the joint to achieve the same capability of variable stiffness while utilizing a relatively weak magnetic setup. Additionally, we fill MR fluid into the origami facets to develop an origami robot that can carry loads while crawling on flat ground and climbing on an inclined surface.

Negative evidence may influence category-based inductive reasoning, but the underlying time course of cognitive brain processing is unclear. This study adopted event-related potentials (ERPs) to investigate this effect by manipulating the category type (related vs. unrelated) and argument type (positive vs. negative) in a semantic category-based induction task. The behavioral results showed that, under unrelated conditions, a negative argument produced greater argument strength and shorter reaction time than a positive argument did. Meanwhile, the ERP results found a negative argument elicited larger P300, N400, and slow negative component amplitudes than a positive argument, which could possibly embody the expectation-related processing produced by memory updating, semantic integration, and the more complex inference-driven information integration and interpretation processes and cognitive load in hypothesis generation. This study provides novel evidence on the temporal course of how negative evidence influences argument strength during semantic category-based induction.

In this study, the Cu-11.85Al-3.88Mn-1.6Nb (wt.%) shape memory alloy with low cost and a highly functional response was manufactured by selective laser melting(SLM). The effects of energy inputs (123–185J/mm3) on their microstructure, mechanical, and shape memory properties were investigated. It was observed that all of the samples were composed of 18R and 2H martensite, and the nanosized (Cu, Mn)3Al3Nd4phase was formed during selective laser melting(SLM). In addition, the good compressive fracture strength and strain were 1652Mpa, and 15.1% respectively. An excellent shape memory effect of 99.26% recovery ratio and 5.32% shape memory strain was obtained by SLM.

The treatment of infected wounds remains a challenging biomedical problem. Some bioactive small‐molecule hydrogelators with unique rigid structures can self‐assemble into supramolecular hydrogels for wound healing. However, they are still suffered from low structural stability and bio‐functionality. Herein, a supramolecular hydrogel antibacterial dressing with a dual nanofibrillar network structure is proposed. A nanofibrillar network created by a small‐molecule hydrogelator, puerarin extracted from the traditional Chinese medicine Pueraria, is interconnected with a secondary macromolecular silk fibroin nanofibrillar network induced by Ga ions via charge‐induced supramolecular self‐assembly. The resulting hydrogel features adequate mechanical strength for sustainable retention at wounds. Good biocompatibility and efficient bacterial inhibition are obtained when the Ga ion concentration is 0.05%. Otherwise, the substantial release of Ga ions and puerarin endows the hydrogel with excellent hemostatic and antioxidative properties. In vivo, evaluation of a mouse‐infected wound model demonstrates that its healing effect outperformed that of a commercially available silver‐containing wound dressing. The experimental group successfully achieves a 100% wound closure rate on day 10. This study sheds new light on the design of nanofibrillar hydrogels based on supramolecular self‐assembly of naturally derived bioactive molecules as well as their clinical use for treating chronic infected wounds. In this work, a supramolecular hydrogel antibacterial dressing with a dual nanofibrillar network structure is fabricated. A nanofibrillar network created by a small‐molecule hydrogelator, puerarin, is interconnected with a secondary macromolecular silk fibroin nanofibrillar network induced by Ga ions. The resulting hydrogel features adequate mechanical strength and excellent hemostatic, antibacterial, and antioxidative properties in a mouse infection model.

Printed Circuit Board (PCB) is one of the most important components of electronic products. But the traditional defect detection methods are gradually difficult to meet the requirements of PCB defect detection. The research on PCB defect recognition method based on convolutional neural network is the current trend. The PCB defect image recognition based on DenseNet169 network model is studied in this paper. In order to reduce the omission of PCB defects in actual detection, it is necessary to further improve the sensitivity of the model. Therefore, a classification model based on the multimodel fusion of the DenseNet169 model and the ResNet50 model is proposed. At the same time, the network structure after multimodel fusion is improved. The improved multimodel fusion model Mix-Fusion enables the network to not only retain the recognition accuracy of the ResNet50 model for NG defects and small defect images but also improve the overall recognition accuracy through the feature reuse and bypass settings of the DenseNet169 model. The experimental results show that when the threshold is 0.5, the sensitivity of the improved multimodel fusion network can reach 99.2%, and the specificity is 99.5%. The sensitivity of Mix-Fusion is 1.2% higher than that of DenseNet169. High sensitivity means fewer missed NG images, and high specificity means less workload for employees. The improved model improves sensitivity and maintains high specificity.

Scholars working in the oil and gas industry have extensively researched the buckling behavior of downhole tubular strings. However, in most theoretical research, continuous contact between tubular strings and wellbores is assumed, which is not always true in experiments. To address this issue, a buckling model for a tubular string placed inside a horizontal wellbore using the beam-column model is built in this paper. Two contact states of the tubular string were considered: point contact and partial continuous contact. The model indicates that reducing the angular displacement of the wave peak position facilitates the tubular string's transition from point to partial continuous contact. Additionally, a higher gravity load or smaller radial clearance increases the likelihood of partial continuous contact. A new displacement calculation method has been proposed based on the buckling model. Using this method, the entire process of contact state changes of a tubular string is simulated under the sinusoidal buckling mode in this study. The results show that the contact state of the tubular string under sinusoidal buckling cannot be assumed to be a continuous contact state, and a theoretical foundation for various evaluations based on the buckling deformation of tubular strings is provided in this study.

A systematic review and meta-analysis were performed to evaluate the necessity for compression therapy with elastic stockings following endovenous thermal ablation (EVTA) for chronic venous insufficiency.

An economical and efficient protocol for the direct construction of amino skipped diynes through the Cu(I)-catalyzed reaction of enaminones and terminal alkynes has been described. Different kinds of symmetrical and asymmetrical 3-amino diynes could be obtained in up to 83% yield through a one-pot reaction under mild conditions.

An efficient and modular strategy was used to obtain enaminones with a wide range of functional groups viaa four-component sequential reaction. This reaction proceeded under mild conditions without a catalyst in one pot. Furthermore, the products could be transformed into thiadiazoles.

An efficient CAN‐mediated C−C bond formation in the oxidative reactions of xanthenes with enaminones under mild reaction conditions are described. A variety of 9H‐xanthene‐9‐ylidene aldehydes could be synthesized in up to 90% yield viaone‐pot manner with good functional group compatibility, which achieved the simultaneous construction of carbon‐carbon double bond and carbon‐oxygen double bond. An efficient method for the synthesis 9H‐xanthene‐9‐ylidene aldehydesviaCAN‐mediated multi‐step oxidative coupling process of xanthene derivatives has been developed, which realized the construction of carbon‐carbon double bond and carbon‐oxygen double bond.

To develop and verify a risk predictive model/scoring system for pulmonary embolism (PE) among hospitalized patients with deep venous thrombosis of the lower extremities (LDVT).

Purpose: To maintain the well integrity, the strength and sealing ability of premium connection should be in the safe scope. ISO 13679 is widely used for evaluating the ability of tubing and casing connection all over the world. FE is adopted to simulate the ISO 13679 tests. Design/methodology/approach: Because of the disadvantage of experiment such as long period, high cost and high requirement on the facility, considering the convenience and universality of finite element method, as well as the contacting nonlinearity and material nonlinearity, three-dimensional finite element model of a certain type of premium connection is established with the consideration of helix angle. The loads exerted on the premium connection are the loads in series B test and thermal cycle test of ISO 13679. The distributions of Von Mises stress and contact pressure in various cases were studied. Findings: The results showed that the bending load has a great influence on the distribution of Von Mises stress and contact pressure for premium connection. The Von Mises stress and contact pressures on the sealing surface are smaller on the tension side and greater on the compression side. With increasing axial compression load, the contact pressures on the tension side are too small, which may lead to sealing failure. The influence of temperature on the performance of premium connection cannot be ignored when choosing or designing premium connections. Both the Von Mises stress and contact pressure decrease slightly during a period of thermal cycle. Although the performance of the premium connection is good in a period of thermal cycle, its performance in a long period should be evaluated. Finite element simulation can effectively simulate the ISO 13679 test procedure and obtain the stress and contact pressure distribution. It can be used as a reference for evaluating the performance of premium connections. Originality/value: Considering the convenience and universality of finite element method, as well as the contacting nonlinearity and material nonlinearity, three-dimensional finite element model of a certain type of premium connection is established with the consideration of helix angle.

A practical and environmentally friendly protocol for the selective oxidation of aryl olefins to arylethanone derivatives by using a Cu(I) catalyst and tert-butyl hydroperoxide (TBHP) has been developed. A series of 2-tert-butoxy-1-arylethanones were obtained in moderate to good yields under mild conditions with high selectivity. In this method, TBHP acts not only as an oxidant but also as the tert-butoxy and carbonyl oxygen sources. This enables one-step oxidation/tert-butoxylation. Various allyl peroxides were also synthesized from allyl substrates.

The limited therapeutic options and increasing drug-resistance call for next-generation influenza antivirals. Due to the essential function in viral replication and high sequence conservation among influenza viruses, influenza polymerase PA–PB1 protein–protein interaction becomes an attractive drug target. Here, we developed an in vitrosplit luciferase complementation-based assay to speed up screening of PA–PB1 interaction inhibitors. By screening 10,000 compounds, we identified two PA–PB1 interaction inhibitors, R160792 and R151785, with potent and broad-spectrum antiviral activity against a panel of influenza A and B viruses, including amantadine-, oseltamivir-, or dual resistant strains. Further mechanistic study reveals that R151785 inhibits PA nuclear localization, reduces the levels of viral RNAs and proteins, and inhibits viral replication at the intermediate stage, all of which are in line with its antiviral mechanism of action. Overall, we developed a robust high throughput-screening assay for screening broad-spectrum influenza antivirals targeting PA–PB1 interaction and identified R151785 as a promising antiviral drug candidate.

To investigate the features of the extremely deep atmospheric boundary layer (ABL) over the Taklimakan Desert (TD) and its influence, this paper utilizes sounding data obtained from a month‐long intensive field campaign carried out in July 2016 over the TD to study the structure of the 5,000‐m‐depth ABL over the desert and the features of its temporal and spatial variations. The differences and causes of the regional circulation are analyzed for both the deep ABL and shallow ABL over the TD. We show that (1) deep ABLs occurred frequently in the hinterland and the surrounding areas of the TD in July 2016. The numbers of days when the ABL height reached 4,000 m at Tazhong, Minfeng, Korla, Ruoqiang, and Kashgar are 8, 9, 5, 4, and 2, respectively, and the numbers of days when the ABL height exceeded 3,000 m at the above locations are 20, 22, 13, 15, and 5, respectively. (2) The ABL height reached 5,000 m over the TD on 1 July 2016. The diurnal variation of the ABL appears in such a manner that it develops and intensifies gradually from southeast to northwest direction. The middle of the desert witnesses large values of ABL heights. The ABL height in the desert is obviously higher than those in the surrounding oases and in the northern part of Xinjiang. (3) On 1 July 2016, a deep ABL process is accompanied by a strong easterly low‐level jet on the following night, which triggers significant air accumulation and dynamic convergence in the lower‐level atmosphere over the middle and west of the TD, thus intensifying the divergence and anticyclonic circulation at the 500‐hPa middle‐level atmosphere. (4) The influence of the deep ABL process on 1 July on the regional circulation mainly occurs below 400 hPa, while its influence is relatively small above 400 hPa. This type of influence is also regional, as it mainly occurs over the TD and its surrounding areas. This study enriches the understanding of the deep ABL process over the TD and its influence. The maximum height of the atmospheric boundary layer (ABL) exceed 5,000 m over the Taklimakan DesertThe deep ABL process is accompanied by a strong easterly low‐level jet (LLJ) on the following nightThe LLJ triggers the convergence upward movement in the lower atmosphere and intensifies the divergence and anticyclonic circulation at 500 hPa

Background: HIV-1 protease inhibitor (PI) is one of the most potent classes of drugs in combinational antiretroviral therapies (cART). When a PI is used in combination with other anti- HIV drugs, cART can often suppress HIV-1 below detection thus prolonging the patient’s lives. However, the challenge often faced by patients is the emergence of HIV-1 drug resistance. Thus, PIs with high genetic-barrier to drug-resistance are needed. Objective: The objective of this study was to develop a novel and simple fission yeast (Schizosaccharomyces pombe) cell-based system that is suitable for high throughput screening (HTS) of small molecules against HIV-1 protease (PR). Methods: A fission yeast RE294-GFP strain that stably expresses HIV-1 PR and green fluorescence protein (GFP) under the control of an inducible nmt1 promoter was used. Production of HIV-1 PR induces cellular growth arrest, which was used as the primary endpoint for the search of PIs and was quantified by an absorbance-based method. Levels of GFP production were used as a counter-screen control to eliminate potential transcriptional nmt1 inhibitors. Results: Both the absorbance-based HIV-1 PR assay and the GFP-based fluorescence assay were miniaturized and optimized for HTS. A pilot study was performed using a small drug library mixed with known PI drugs and nmt1 inhibitors. With empirically adjusted and clearly defined double-selection criteria, we were able to correctly identify the PIs and to exclude all hidden nmt1 inhibitors. Conclusion: We have successfully developed and validated a fission yeast cell-based HTS platform for the future screening and testing of HIV-1 PR inhibitors.

In this paper, a new buckling model of coiled tubing (CT) in a three-dimensional curved wellbore is established, considering the influence of the curvature and toolface angle of the wellbore and the initial CT bending curvature. First, with the wellbore curvature and toolface angle, the CT buckling configuration is based on the lower or outer curved side of the wellbore. When the initial CT bending curvature is less than the critical bending curvature, the initial CT configuration in the wellbore undergoes sinusoidal buckling; otherwise, the CT undergoes helical buckling. Second, the buckling model is solved by the energy method. After solving this buckling model, the critical CT helical buckling load, the critical bending curvature, and the quantitative relationship between the axial load and pitch can be obtained. Third, the CT contact force calculation method under a helical buckling configuration in a three-dimensional curved wellbore is given by combining the buckling model and the beam-column model. The influence of the initial bending curvature is also considered. Finally, the calculated values of the buckling model and contact force calculation method were compared with existing experimental data and published models to validate the proposed model. Therefore, the methods presented in this paper can be used to not only predict helical CT buckling but also optimize downhole engineering design parameters considering the influence of the initial bending curvature in more realistic drilling wellbore conditions.

A spectroscopic detection system for the accurate monitoring of carbon dioxide (CO_2) in exhaled breath was realized by tunable diode laser absorption spectroscopy (TDLAS) in conjunction with a vertical-cavity surface-emitting laser (VCSEL) and a multipass cell with an effective optical path-length of 20 m. The VCSEL diode emitting light with an output power of 0.8 mW, covered the strong absorption line of CO_2 at 6330.82 cm^−1 by drive-current tuning. The minimum detectable concentration of 0.769‰ for CO_2 detection was obtained, and a measurement precision of approximately 100 ppm was achieved with an integration time of 168 s. Real-time online measurements were carried out for the detection of CO_2 expirograms from healthy subjects, different concentrations were obtained in dead space and alveolar gas. The exhaled CO_2 increased significantly with the increasing physical activity, reaches its maximal value at the beginning of respiratory compensation and then decreased slightly until maximal exercise. The developed measurement system has a great potential to be applied in practice for the detection of pulmonary diseases associated with CO_2 retention.

Enterovirus D68 (EV-D68) is an atypical nonpolio enterovirus that mainly infects the respiratory system of humans, leading to moderate-to-severe respiratory diseases. In rare cases, EV-D68 can spread to the central nervous system and cause paralysis in infected patients, especially young children and immunocompromised individuals. There is currently no approved vaccine or antiviral available for the prevention and treatment of EV-D68. In this study, we aimed to improve the antiviral potency and selectivity of a previously reported EV-D68 inhibitor, dibucaine, through structure–activity relationship studies. In total, 60 compounds were synthesized and tested against EV-D68 using the viral cytopathic effect assay. Three compounds 10a, 12a, and 12cwere identified to have significantly improved potency (EC50< 1 μM) and a high selectivity index (>180) compared with dibucaine against five different strains of EV-D68 viruses. These compounds also showed potent antiviral activity in neuronal cells, such as A172 and SH-SY5Y cells, suggesting they might be further developed for the treatment of both respiratory infection as well as neuronal infection.

Influenza viruses are severe human pathogens that pose persistent threat to public health. Each year more people die of influenza virus infection than that of breast cancer. Due to the limited efficacy associated with current influenza vaccines, as well as emerging drug resistance from small molecule antiviral drugs, there is a clear need to develop new antivirals with novel mechanisms of action. The influenza virus polymerase complex has become a promising target for the development of the next-generation of antivirals for several reasons. Firstly, the influenza virus polymerase, which forms a heterotrimeric complex that consists of PA, PB1, and PB2 subunits, is highly conserved. Secondly, both individual polymerase subunit (PA, PB1, and PB2) and inter-subunit interactions (PA-PB1, PB1- PB2) represent promising drug targets. Lastly, growing insight into the structure and function of the polymerase complex has spearheaded the structure-guided design of new polymerase inhibitors. In this review, we highlight recent progress in drug discovery and assay development targeting the influenza virus polymerase complex and discuss their therapeutic potentials.

We present a silver-catalyzed reaction of acceptor-enynals with alkynes to assemble tetracyclic framework of fluorenols efficiently, in which the reaction was proposed to proceed through an unfavorable 6-endo-digcyclization, followed by a tandem [4+2] cycloaddition/Friedel–Crafts reaction. The reaction could be conducted in one pot for diaryl alkynes substrates. For terminal aryl alkyne or arylalkyl alkyne substrates, the Friedel–Crafts reaction has to be performed in the absence of alkynes. The control reactions demonstrated that there was competition between [Ag]···alkyne and [Ag]···O=CR2. Unfavorable 6-endo-digcyclizationof acceptor-enynals occurred under the silver catalyst to form isobenzopyrylium salt intermediate, which efficiently underwent tandem [4+2] cyclization/Friedel–Crafts reaction with alkynes to synthesize fluorenol derivatives. The reaction could be conducted in one pot for diaryl alkynes substrates, whereas for terminal aryl alkyne or arylalkyl alkyne substrates, the subsequent Friedel–Crafts reaction has to be performed in the absence of alkynes. The control reactions demonstrated that there was competition between [Ag]···alkyne and [Ag]···O=CR2.

Using potentially best available rainfall data sets for the entire country of Japan (spatial scales of 1‐ and 20‐km), we analyze the 1–24 hr and city‐scale (1–400 km2) extreme rainfalls for both current (2006–2020) and future periods (2081–2109) at 1.5 K global warming scenario, complementing previous work that focuses on either coarse spatial and temporal scales or other warming scenarios (e.g., RCP and 2 K warming scenarios). A peak‐over‐threshold (POT)‐based approach is applied to compute areal reduction factor (ARF) for subsequently establishing intensity‐duration‐area‐frequency (IDAF) curves. Our results reveal that ARF values generally decrease with increasing area size and increase with longer duration and are affected by multiple underlying physical phenomena. Moreover, we find a greater increase in the rainfall intensities for shorter durations and higher return periods, ranging from 9.4% (1‐hr) to 6.2% (24‐hr), averaged for all return periods and 8.3% (25‐year) to 7.3% (2‐year), averaged for all rainfall durations. Spatially, extreme rainfall intensities are projected to increase by 8.9% in northern Japan (albeit with a less intense rainfall intensity in the current period), which is greater than the rest of the country (6.8%), underscoring the need to focus more on infrastructure designs in northern Japan. The projected IDAF curves further display an increase in the frequency of extreme events at city‐scale, for example, 25‐year extreme rainfall events in 2006–2020 would likely be 5‐10‐year events in 2081–2109. Our results with the state‐of‐the‐art data and implementable approach can be utilized for policymaking to reduce the warming‐induced risks in Japan and beyond. For the first time, we analyze the city‐scale and sub‐daily extreme rainfall for the entire country of Japan by using high‐quality data setsAreal reduction factor values generally decrease with increasing area size and increase with longer duration and are affected by multiple physical phenomenaUnder 1.5 K warming, extreme rainfall will increase more for shorter durations and higher return periods, especially in northern Japan For the first time, we analyze the city‐scale and sub‐daily extreme rainfall for the entire country of Japan by using high‐quality data sets Areal reduction factor values generally decrease with increasing area size and increase with longer duration and are affected by multiple physical phenomena Under 1.5 K warming, extreme rainfall will increase more for shorter durations and higher return periods, especially in northern Japan

Understanding the characteristics of the structure of desert atmospheric boundary layer and its land surface process is of great importance to the simulations of regional weather and climate. To investigate the atmospheric boundary layer structure and its forming mechanism of Taklimakan Desert, and to improve the accuracy and precision of regional weather and climate simulations, we carried out a GPS radiosonde observation experiment in the hinterland of Taklimakan Desert from 25 June to 3 July, 2015. Utilizing the densely observed sounding data, we analyzed the vertical structures of daytime convective boundary layer and nighttime stable boundary layer in summer over this region, and also discussed the impacts of sand-dust and precipitation events on the desert atmospheric boundary layer structure. In summer, the convective boundary layer in the hinterland of Taklimakan Desert developed profoundly and its maximum height could achieve 4,000 m; the stable boundary layer at nighttime was about 400–800-m thick and the residual mixing layer above it could achieve a thickness over 3,000 m. Sand-dust weather would damage the structures of nighttime stable boundary layer and daytime convective boundary layer, and the dust particle swarm can weak the solar radiation absorbed by the ground surface and further restrain the strong development of convective boundary layer in the daytime. Severe convective precipitation process can change the heat from the ground surface to the atmosphere in a very short time, and similarly can damage the structure of desert atmospheric boundary layer remarkably. Moreover, the height of atmospheric boundary layer was very low when raining. Our study verified the phenomenon that the atmospheric boundary layer with supernormal thickness exists over Taklimakan Desert in summer, which could provide a reference and scientific bases for the regional numerical models to better represent the desert atmospheric boundary layer structure.