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Ir/Cu dual-catalysed allylation constructs vicinal tertiary and N-substituted quaternary stereogenic centres of two alkaloids in a single operation.

Consolidated undrained triaxial shear tests were performed on undisturbed saturated structured clay at three unloading rates (0.1, 0.25, and 2.5 kPa/min) using a GDS triaxial system to determine the effects of different unloading rates and unloading stress paths on the stress–strain relationship, pore pressure variation, and failure strength characteristics of Zhanjiang structured clay. Microstructural changes in the clay were observed during shear tests at different unloading rates. Furthermore, the obtained stress–strain relationship indicates strain-softening under different unloading stress paths. Under the same axial strain, a larger unloading rate caused a larger deviatoric stress. Under the same conditions, the higher the confining pressure, the greater the peak pore pressure, the smaller the unloading rate, the greater the pore pressure development, and the greater the variation in the pore pressure. Moreover, the undrained shear strength increased with an increase in the unloading rate from 0.1 to 2.5 kPa/min. The change in the unloading rate had a greater effect on the undrained strength under the passive tensile path than that under the passive compression path. The microstructure of the Zhanjiang structured clay changed after shear tests at different unloading rates, exhibiting various degrees of adjustment in the particle arrangement, contact relations, pore sizes, and shapes.

PurposeThe development of urban underground complexes (UUCs) has great positive significance for improving urban safety. Therefore, it is necessary to identify the key factors of the people's behavior of evacuation route selection (BERS) for fire emergencies and UUCs’ development. This study aims to find out the factors affecting people's BERS in the evacuation process of UUCs.Design/methodology/approachThis study aims to find out the factors affecting people's BERS in the evacuation process of UUCs. To achieve this goal, the authors conducted a field experiment in F City. Furthermore, the people's BERS are obtained by using a structural equation model and compared with the field test results.FindingsThe authors found that the key factors for people's BERS are lighting conditions, route distance, flow direction guidance and indication. The results of this study contribute to the safety field by providing key factors for fire emergencies. It can also be used to improve fire safety management, evacuation strategies and assist in the development of intelligent evacuation systems.Originality/valueThe results of this study contribute to the safety field by providing key factors for fire emergencies. It can also be used to improve fire safety management, evacuation strategies and assist in the development of intelligent evacuation systems.

Athetis lepigone Möschler (Lepidoptera, Noctuidae) is a common maize pest in Europe and Asia. However, there is no long-term effective management strategy is available yet to suppress its population. Adults rely heavily on olfactory cues to locate their optimal host plants and oviposition sites. Pheromone-binding proteins (PBPs) are believed to be responsible for recognizing and transporting different odorant molecules to interact with receptor membrane proteins. In this study, the ligand-binding specificities of two AlepPBPs (AlepPBP2 and AlepPBP3) for sex pheromone components and host plant (maize) volatiles were measured by fluorescence ligand-binding assay. The results demonstrated that AlepPBP2 had a high affinity with two pheromones [(Z)-7-dodecenyl acetate, Ki = 1.11 ± 0.1 μM, (Z)-9-tetradecenyl acetate, Ki = 1.32 ± 0.15 μM] and ten plant volatiles, including (-)-limonene, α-pinene, myrcene, linalool, benzaldehyde, nonanal, 2-hexanone, 3-hexanone, 2-heptanone and 6-methyl-5-hepten-2-one. In contrast, we found that none of these chemicals could bind to AlepPBP3. Our results clearly show no significant differences in the functional characterization of the binding properties between AlepPBP2 and AlepPBP3 to sex pheromones and host plant volatiles. Furthermore, molecular docking was employed for further detail on some crucial amino acid residues involved in the ligand-binding of AlepPBP2. These findings will provide valuable information about the potential protein binding sites necessary for protein-ligand interactions which appear as attractive targets for the development of novel technologies and management strategies for insect pests.

Spodoptera litura is an important pest that causes significant economic damage to numerous crops worldwide. Sex pheromones (SPs) mediate sexual communication in S. litura and show a characteristic degree of rhythmic activity, occurring mainly during the scotophase; however, the specific regulatory mechanisms remain unclear. Here, we employed a genome-wide analysis to identify eight candidate circadian clock genes in S. litura. Sequence characteristics and expression patterns were analyzed. Our results demonstrated that some circadian clock genes might regulate the biosynthesis and perception of SPs by regulating the rhythmic expression of SP biosynthesis-related genes and SP perception-related genes. Interestingly, all potential genes exhibited peak expression in the scotophase, consistent with the SP could mediate courtship and mating behavior in S. litura. Our findings are helpful in elucidating the molecular mechanism by which circadian clock genes regulate sexual communication in S. litura.

Objectives To investigate the diagnostic performance of single-source dual-energy computed tomography (DECT) based on gemstone spectral imaging technology (including Discovery CT750HD and Revolution CT) in patients with suspected feet/ankles gouty arthritis, and evaluate the urate deposition with a novel semi-quantitative DECT scoring system. Methods A total of 196 patients were consecutively included. Feet and ankles were evaluated in all patients by single-source DECT scan. The 2015 EULAR/ACR criteria were used as the reference for the diagnosis of gout. The sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) of DECT for the diagnosis of gout in the early (≤1 year), middle (1–3 years), and late (> 3 years) disease durations were calculated. Besides, a novel semi-quantitative DECT scoring system was assessed for the measurement of urate deposition, and the correlation between the scores and the clinical and serological data were also evaluated. Moreover, the influences of artifacts on the diagnostic performance of DECT were also determined. Results The sensitivity, specificity, and AUC of DECT in 196 patients were 38.10, 96.43%, and 0.673 in the early-stage group; 62.96, 100.00%, and 0.815 in the middle-stage group; and 77.55, 87.50%, and 0.825 in the late-stage group, respectively. The overall diagnostic accuracies in the AUC of DECT (Discovery CT750HD and Revolution CT) in the middle and late stages of gout were higher than that in the early stage of gout. Besides, the monosodium urate crystals were deposited on the first metatarsophalangeal joints and ankles/midfeet. Age, the presence of tophus, bone erosion, and disease duration considerably affected the total urate score. No statistical difference in the positive detection of nail artifact, skin artifact, vascular calcification, and noise artifact was found between the case and control groups. Conclusion DECT (Discovery CT750HD and Revolution CT) showed promising diagnostic accuracy for the detection of urate crystal deposition in gout but had limited diagnostic sensitivity for short-stage gout. Longer disease duration, the presence of tophus, and bone erosion were associated with the urate crystal score system. The artifacts do not remarkably affect the diagnostic performance of DECT in gout.

The injection molding process of a mold with multiple cavities can reduce the mold space, but the process is complicated and the product is prone to warpage. In order to reduce the transparent parts warpage of such a mold, by optimizing injection molding process parameters, an optimization technique combining orthogonal experiment, Kriging model and an optimization algorithm is proposed. First, the orthogonal experiment is designed, based on Computer Aided Engineering (CAE) simulation results, while the significant factors affecting the warpage are selected. On this basis, the Kriging model is established to map the nonlinear function relationship between the significant factors and the warpage. Specifically in this paper, four types of correlation functions, affecting the model precision accuracy, are used to establish the Kriging model and the high-precision accuracy model is selected. A numerical optimization algorithm, direct search approach and global exploration method are used to optimize the model, so as to obtain the optimal injection molding parameters producing the minimum warpage. Finally, CAE simulation and experimental validation prove the effectiveness and reliability of the proposed optimization method.

Fe-Al compounds possess a combination of high strength and corrosion resistance at high temperatures. However, increasing Al content to make them lighter results in embrittlement. Here, we investigate the high-temperature behavior of a novel, lightweight, ultra-fine-layered FeAl/FeAl2 material. We report a transition from unstable to stable plasticity at 450 °C. Below 450 °C, deformation is dominated by localized shear deformation within the soft FeAl layers, while above 450 °C, it proceeds by co-deformation between FeAl and the brittle FeAl2 layers. We show that co-deformation is associated with the temperature at which the interface converts from sliding to sourcing dislocations for FeAl2.

Objective: Deep learning image reconstruction (DLIR) is a new reconstruction method for maintaining image quality at reduced radiation dose. The purpose of this study was to compare image quality of reduced-dose DLIR images with the standard-dose adaptive statistical iterative reconstruction (ASIR-V) images in chest CT. Methods: Our prospective study included 48 adult patients (30 women and 18 men, mean age ±SD, 49.8 ± 14.3 years) who underwent both the standard-dose CT (SDCT) and low-dose CT (LDCT) on a GE Revolution CT scanner. All patients gave written informed consent. All scans were reconstructed with ASIR-V40%. Additionally, LDCT scans were reconstructed with DLIR with high-setting (DLIR-H) and medium-setting (DLIR-M). Image noise and contrast-noise-ratio (CNR) of thoracic aorta with different reconstruction modes were measured and compared. Results: LDCT reduced radiation dose by 96% compared with SDCT (CTDIvol: 0.54mGy vs 12.46mGy). In LDCT, DLIR significantly reduced image noise compared with the state-of-the-art ASIR-V40% with DLIR-H provided the lowest image noise and highest image quality score. In addition, the image noise, CNR of aorta and overall image quality of the low-dose DLIR-H images did not have significant difference compared with the SDCT ASIR-V40% images (all p > 0.05). Conclusion: DLIR significantly reduces image noise in LDCT chest scans and provides similar image quality as the SDCT ASIR-V images at 4% of the radiation dose. Advances in knowledge: DLIR uses high-quality FBP data to train deep neural networks to learn how to distinguish between signal and noise, and effectively suppresses noise without affecting anatomical and pathological structures. It opens a new era of CT image reconstruction. DLIR significantly reduces image noise and improves image quality compared with ASIR-V40% under same radiation dose condition. DLIR-H achieves similar image quality at 4% radiation dose as ASIR-V40% at standard-dose level in non-contrast chest CT.

The tobacco cutworm Spodoptera litura (Lepidoptera: Noctuidae) is a polyphagous pest with a highly selective and sensitive chemosensory system involved in complex physiological behaviors such as searching for food sources, feeding, courtship, and oviposition. However, effective management strategies for controlling the insect pest populations under threshold levels are lacking. Therefore, there is an urgent need to formulate eco-friendly pest control strategies based on the disruption of the insect chemosensory system. In this study, we identified 158 putative chemosensory genes based on transcriptomic and genomic data for S. litura, including 45 odorant-binding proteins (OBPs, nine were new), 23 chemosensory proteins (CSPs), 60 odorant receptors (ORs, three were new), and 30 gustatory receptors (GRs, three were new), a number higher than those reported by previous transcriptome studies. Subsequently, we constructed phylogenetic trees based on these genes in moths and analyzed the dynamic expression of various genes in head capsules across larval instars using quantitative real-time polymerase chain reaction. Nine genes–SlitOBP8, SlitOBP9, SlitOBP25, SlitCSP1, SlitCSP7, SlitCSP18, SlitOR34, SlitGR240, and SlitGR242–were highly expressed in the heads of 3- to 5-day-old S. litura larvae. The genes differentially expressed in olfactory organs during larval development might play crucial roles in the chemosensory system of S. litura larvae. Our findings substantially expand the gene inventory for S. litura and present potential target genes for further studies on larval feeding in S. litura.

Insects employ a sensitive chemosensory system to accurately recognize external odorants, which help them to make a behavioral response quickly. Semiothisa cinerearia has caused serious damages to Sophora japonica L. in recent years, and there is still a lack of effective strategy to control the pest. Although the two type-II sex pheromones of S. cinerearia, 6Z,9Z-cis-3,4-epoxy-17:H and 3Z,6Z,9Z-17:H, have been identified for 30 years, the molecular mechanisms underlying the chemosensation of the two sex pheromones are still unknown. Here, we found that there are differences in the types of antennae sensilla between sexes, and revealed 146 putative chemosensory genes in the antennal transcriptome. Among these genes, 11 and 40 of them displayed male-biased and female-biased expression, respectively. Our findings greatly improve the chemosensory gene resources for S. cinerearia and provide a foundation for functional studies of these sex-biased genes on the chemosensation of sex pheromones and on other sex-related behaviors.

Banana fruit is prone to chilling injury (CI) during cold storage, resulting in quality deterioration and commodity reduction. The hot water treatment (HWT), dipping banana fruit in hot water (52 °C) for 3 min, reduced CI symptom at 7 °C storage. The purpose of this study was to investigate the potential molecular mechanism of HWT on the alleviation of CI of postharvest banana fruit. It was found that HWT treatment obviously inhibited the increases in CI index, relative electrolytic leakage, and the contents of malonaldehyde (MDA) and O

Spodoptera litura is an important pest that causes significant economic damage to numerous crops worldwide. Sex pheromones (SPs) mediate sexual communication in S. litura and show a characteristic degree of rhythmic activity, occurring mainly during the scotophase; however, the specific regulatory mechanisms remain unclear. Here, we employed a genome-wide analysis to identify eight candidate circadian clock genes in S. litura. Sequence characteristics and expression patterns were analyzed. Our results demonstrated that some circadian clock genes might regulate the biosynthesis and perception of SPs by regulating the rhythmic expression of SP biosynthesis-related genes and SP perception-related genes. Interestingly, all potential genes exhibited peak expression in the scotophase, consistent with the SP could mediate courtship and mating behavior in S. litura. Our findings are helpful in elucidating the molecular mechanism by which circadian clock genes regulate sexual communication in S. litura.

As a primary cause of dementia and death in older people, Alzheimer’s disease (AD) has become a common problem and challenge worldwide. Abnormal accumulation of tau proteins in the brain is a hallmark pathology of AD and is closely related to the clinical progression and severity of cognitive deficits. Here, we found that overexpression of phosphatase and tensin homolog (PTEN)-induced kinase 1 (PINK1) effectively promoted the degradation of tau, thereby rescuing neuron loss, synaptic damage, and cognitive impairments in a mouse model of tauopathy with AAV-full-length human Tau (hTau) injected into the hippocampal CA1 area (hTau mice). Overexpression of PINK1 activated autophagy, and chloroquine but not MG132 reversed the PINK1-induced decrease in human Tau levels and cognitive improvement in hTau mice. Furthermore, PINK1 also ameliorated mitochondrial dysfunction induced by hTau. Taken together, our data revealed that PINK1 overexpression promoted degradation of abnormal accumulated tau via the autophagy–lysosome pathway, indicating that PINK1 may be a potential target for AD treatment.

The persistent transactivation of epidermal growth factor receptor (EGFR) causes subsequent activation of the TGF‐β/Smad3 pathway, which is closely associated with fibrosis and cell proliferation in diabetic nephropathy (DN), but the exact mechanism of persistent EGFR transactivation in DN remains unclear. ARAP1, a susceptibility gene for type 2 diabetes, can regulate the endocytosis and ubiquitination of membrane receptors, but the effect of ARAP1 and its natural antisense long non‐coding RNA (lncRNA), ARAP1‐AS2, on the ubiquitination of EGFR in DN is not clear. In this study, we verified that the expression of ARAP1 and ARAP1‐AS2 was significantly up‐regulated in high glucose‐induced human proximal tubular epithelial cells (HK‐2 cells). Moreover, we found that overexpression or knockdown of ARAP1‐AS2 could regulate fibrosis and HK‐2 cell proliferation through EGFR/TGF‐β/Smad3 signalling. RNA pulldown assays revealed that ARAP1‐AS2 directly interacts with ARAP1. Coimmunoprecipitation, dual‐immunofluorescence and ubiquitination assays showed that ARAP1 may maintain persistent EGFR activation by reducing EGFR ubiquitination through competing with Cbl for CIN85 binding. Taken together, our results suggest that the lncRNA ARAP1‐AS2 may promote high glucose‐induced proximal tubular cell injury via persistent EGFR/TGF‐β/Smad3 pathway activation by interacting with ARAP1.

Background Acute generalized exanthematous pustulosis (AGEP) is a severe cutaneous adverse reaction characterized by sterile pustules on erythematous skin associated with fever and leukocytosis. The annual incidence of AGEP is estimated to be 1-5 cases per million. Cases of AGEP with oral mucosa involvement have been reported. However, reports of AGEP involving airway mucosa are limited. Case summary We report a 42-year-old woman with serious AGEP involving the airway mucosa. The patient initially developed fever and a small rash on her forehead and face. Over the next 2 d, she developed a diffuse, pustular rash over her trunk and legs. In addition, she complained of a cough with white foam-like sputum, chest tightness and dyspnea. Four days later, due to dyspnea, her mental status started to gradually deteriorate. She became more and more drowsy. Biopsies of the skin and airway mucosa suggested the diagnosis of AGEP. According to the European study of severe cutaneous adverse reactions group's scoring system, the patient scored +6 indicating a probable diagnosis of AGEP. She received intravenous methylprednisolone 120 mg/12 h for 3 d, and was eventually discharged in good condition. This patient had already experienced respiratory failure and airway mucosa involvement on admission; however, the clinicians had an insufficient understanding of AGEP. Glucocorticoid was administered for more than 10 d following onset of the disease, and her overall prognosis was satisfactory. Conclusion This case represents a rare clinical feature of AGEP and an important finding for clinicians.

Athetis lepigone is a polyphagous pest found around the world that feeds on maize, wheat, and various other important crops. Although it exhibits a degree of resistance to various chemical insecticides, an effective pest-control method has not yet been developed. The sex pheromone communication system plays an essential role in the mating and reproduction of moths, in which pheromone-binding proteins (PBPs) are crucial genes. In this study, we cloned and purified the protein AlepPBP1 using an E. coli expression system and found it had a higher binding affinity to two sex pheromones of A. lepigone, namely, Z7-12:Ac and Z9-14:Ac (with Ki 0.77 ± 0.10 and 1.10 ± 0.20 μM, respectively), than to other plant volatiles. The binding-mode analysis of protein conformation with equilibrium stabilization was obtained using molecular dynamics (MD) simulation and indicated that hydrophobic interactions involving several nonpolar residues were the main driving force for the binding affinity of AlepPBP1 with sex pheromones. Computational alanine scanning (CAS) was performed to further identify key amino acid residues and validate their binding contributions. Each key residue, including Phe36, Trp37, Val52, and Phe118, was subsequently mutated into alanine using site-directed mutagenesis. Binding assays showed that the efficient binding abilities to Z7-12:Ac (F36A, W37A, and F118A) and Z9-14:Ac (F36A, W37A, V52A, and F118A) were almost lost in the mutated proteins. Our results demonstrated that these key amino acid residues are crucial for determining the binding ability of AlepPBP1 to sex pheromones. These findings provide a basis for the use of AlepPBP1 in the studies as a specific target for the development of novel behavioral antagonists with marked inhibition or mating-disruption abilities using computer-aided drug design (CADD).

Three new alkaloids (1-3) were isolated from the rhizomes of Menispermum dauricum. The structures and configurations were established by extensive spectroscopic analyses, including 1D, 2D NMR, and ECD.

In recent years, the rapid development of marine science has put forward higher and higher requirements for the processing of ship-radiated noise signal. Ship-radiated noise is the noise signal generated by the vibration of various mechanical equipment or the movement of the hull and radiated into the sea when the ship is traveling. Ship-radiated noise signal contains a large number of time-varying, nonlinear and non-stationary components. The denoising processing of ship-radiated noise is the most critical part of underwater acoustic signal processing. In order to more effective reduce the noise of the ship-radiated noise signal, a new denoising method for underwater acoustic signal based on mutual information variational mode decomposition (MIVMD), multivariate multiscale dispersion entropy (mvMDE), and lift wavelet threshold (LWTD) and Savitzky Golay filter (S-G filter), named MIVMD-mvMDE-LWTD-SG, is proposed. Firstly, MIVMD is used to decompose the original signal into $n$ sub-signals. Secondly, the mvMDE value of each sub-signal is calculated, and the $n$ sub-signals are divided into high-frequency components and low-frequency components according to the threshold. Then, S-G filter and LWTD method are used to reduce the noise of low-frequency components and high-frequency components respectively. Finally, the low-frequency components and high-frequency components after the denoising processing are reconstructed to obtain the denoising signal. In order to verify the effectiveness of the proposed method, the proposed method is used to reduce the noise of chaotic signal under different signal-to-noise ratios (SNR), and compared with the EMD-mvMDE-LWTD and MIVMD-mvMDE-LWTD method. The results show that the proposed method can effective remove the noise in the chaotic signal, better distinguish the adjacent trajectories in the phase space, approximate the real chaotic attractor trajectory, and better retain the useful information in the chaotic signal. The proposed method is further applied to the actual ship-radiated noise signal, and the experimental analysis shows its effectiveness, which lays a solid foundation for further prediction and detection.

To investigate the optimal pre- and post-adaptive statistical iterative reconstruction-V (ASiR-V) levels in pediatric abdominal computed tomography (CT) to minimize radiation exposure and maintain image quality using an animal model. A total of 10 standard piglets were selected and scanned to obtain unenhanced and enhanced images under different pre-ASiR-V conditions. The corresponding images were obtained using ASiR-V algorithm at different post-ASiR-V levels. CT value, signal-to-noise ratio (SNR), contrast noise ratio (CNR) of abdominal tissues, subjective image score, and radiation dose of unenhanced and enhanced scans were analyzed. With the increase of pre-ASiR-V level, the radiation dose in piglets gradually decreased (P < 0.05). Within the same group of pre-ASiR-V, the image noise was decreased (P < 0.05) by increasing post-ASiR-V level. There was no statistical difference between SNR and CNR values. In unenhanced CT, the subjective score of the images with the combination of 40% pre- and 60% post-ASiR-V levels had no statistical difference compared to the combination of 0% pre- and 60% post-ASiR-V levels, while the radiation dose decreased by 31.6%. In the enhanced CT, the subjective image score with the 60% pre- and 60% post-ASiR-V combination had no statistical difference compared to the 0% pre- and 60% post-ASiR-V combination, while the radiation dose was reduced by 48.9%. The combined use of pre- and post-ASiR-V maintains image quality at the reduced radiation dose. The optimal level for unenhanced CT is 40% pre-combined with 60% post-ASiR-V, while that for enhanced CT is 60% pre- combined with 60% post-ASiR-V in pediatric abdominal CT.

Background: As a life-saving therapy for patients with acute respiratory failure (ARF)Mechanical ventilation has catalyzed the development of modern emergency medicine and intensive care units.Another way to support respiratory or cardiac functions is extracorporeal membrane oxygenation (ECMO).Based on previous studies, the increased pre-ECMO time of mechanical ventilation is a significant independent predictor of the poorer outcome . Removal or maintaining of mechanical ventilation during ECMO is still debatable. Methods: We analyzed the clinical data of 23 patients veno-venous ECMO therapy with acute respiratory failure due to adult community-acquired pneumonia.They were divided into two groups: group A (removed of mechanical ventilation, n=10) and group B ( maintaining of mechanical ventilation,n=13).Demographic data, including gender, age, smoking habits were collected. General characteristics and Clinical characteristics of patients were also recorded, in order to discuss whether the retention or removal of trachea cannula and continued mechanical ventilation during ECMO can affect patients’ prognosis. Results: After analysis, patients in the Group B were older than the Group A (61.0 y [54.5-67.5] vs 39.0 y [24.0-61.8], P=0.021). The median APACHE Ⅱ score of 23 patients before ECMO therapy was 25.0 (IQR, 21.0-28.0), and the Group A had a lower initial APACHE Ⅱ score than the Group B (21.5 [20.8-24.3] vs 28.0 [24.0-29.0], P=0.005)(Table 1).The group A with a survival rate of 80% , and the group B presenting a survival rate of 23.1%.The difference in the survival rate between the two groups was statistically significant (P=0.012).No differences in other items were found between the two groups.Conclusions: The final results showed that the removing of mechanical ventilation during ECMO can improve the survival rate and prognosis in patients with ARF.

As a primary cause of dementia and death in older people, Alzheimer’s disease (AD) has become a common problem and challenge worldwide. Abnormal accumulation of tau proteins in the brain is a hallmark pathology of AD and is closely related to the clinical progression and severity of cognitive deficits. Here, we found that overexpression of phosphatase and tensin homolog (PTEN)-induced kinase 1 (PINK1) effectively promoted the degradation of tau, thereby rescuing neuron loss, synaptic damage, and cognitive impairments in a mouse model of tauopathy with AAV-full-length human Tau (hTau) injected into the hippocampal CA1 area (hTau mice). Overexpression of PINK1 activated autophagy, and chloroquine but not MG132 reversed the PINK1-induced decrease in human Tau levels and cognitive improvement in hTau mice. Furthermore, PINK1 also ameliorated mitochondrial dysfunction induced by hTau. Taken together, our data revealed that PINK1 overexpression promoted degradation of abnormal accumulated tau via the autophagy–lysosome pathway, indicating that PINK1 may be a potential target for AD treatment.

Calculations on the spectroscopic constants and transition properties of the first three states (a1Δ, b1Σ+, and X3Σ−) of the SbH molecule were performed under the relativistic framework using the exact two-component Hamiltonian (X2C). The potential energy curves in the Franck–Condon region were computed and compared with the previous values. Furthermore, the transition dipole moments for the weak spin-forbidden transitions (b0+–X10+, b0+–X21, X10+–X21, and X21–a2) were reported. The spontaneous radiative lifetime of the b1Σ+ (υ′ = 0) state was calculated as 163.5±7.5 μ s, which is in reasonable agreement with the latest experimental value of 173±3 μ s. The spontaneous radiative lifetimes of the X21 (υ′ = 0) state and the a2 (υ′ = 0) state were calculated to be 48.6 s and ∼ 8 ms, respectively. Our study is expected to be a benchmark transition property computation for comparison with other theoretical and experimental results. The datasets presented in this paper, including the transition dipole moments, are openly available at https://dx.doi.org/10.11922/sciencedb.j00113.00018.

Background Athetis lepigone, a noctuid moth feeding on more than 30 different crops worldwide, has evolved a sophisticated, sensitive, and specific chemosensory system to detect and discriminate exogenous chemicals. Odorant-binding proteins (OBPs) are the most important agent in insect chemosensory systems to be explored as an alternative target for environmentally friendly approaches to pest management. Results To investigate the olfactory function of A. lepigone OBPs (AlepOBPs), AlepOBP6 was identified and expressed in Escherichia coli. The binding affinity of the recombinant OBP to 20 different ligands was then examined using a competitive binding approach. The results revealed that AlepOBP6 can bind to two sex pheromones and ten maize volatiles, and its conformation stability is pH dependent. We also carried out a structure-function study using different molecular approaches, including structure modeling, molecular docking, and a mutation functional assay to identify amino acid residues (M39, V68, W106, Q107, and Y114) involved in the binding of AlepOBP6 to both sex pheromones and maize volatiles in A. lepigone. Conclusion These results suggest that AlepOBP6 is likely involved in mediating the responses of A. lepigone to sex pheromones and maize volatiles, which may play a pivotal function in mating, feeding, and oviposition behaviors. This study not only provides new insight into the binding mechanism of OBPs to sex pheromones and host volatiles in moths, but also contributes to the discovery of novel target candidates for developing efficient behavior disruptors to control A. lepigone in the future.

In this paper, two kinds of ultrasonic milling systems, the axial vibration of the tool and the horizontal vibration of the workpiece, were designed, built, and tested. Then taking TC4 titanium alloy as the research object, the ultrasonic machining system was used to carry out milling of titanium alloy, and the influence of different vibration directions on tool wear and surface morphology characteristics was obtained. The results show that the deviation between the designed vibration system and the theoretical value is small, and the test results are good. Then, the experimental analysis showed that when the same volume of titanium alloy material was removed under the two vibration modes, the tool vibration can reduce the tool wear compared with the workpiece vibration, no matter in terms of the wear amount of the rear tool face, or in terms of the bonding wear and oxidation wear. It is found that the root cause of surface micro-texture was the periodic change of cutting depth, and the application of axial vibration was more conducive to the generation of micro-texture than the horizontal vibration of workpiece.

Over the past decades, remarkable progress on phosphoramidite chemistry-based large-scale de novo oligonucleotide synthesis has been achieved, enabling numerous novel and exciting applications. Among them, de novo genome synthesis and DNA data storage are striking. However, to make these two applications more practical, the synthesis length, speed, cost, and throughput require vast improvements, which is a challenge to be met by the phosphoramidite chemistry. Harnessing the power of enzymes, the recently emerged enzymatic methods provide a competitive route to overcome this challenge. In this review, we first summarize the status of large-scale oligonucleotide synthesis technologies including the basic methodology and large-scale synthesis approaches, with special focus on the emerging enzymatic methods. Afterward, we discuss the opportunities and challenges of large-scale oligonucleotide synthesis on de novo genome synthesis and DNA data storage respectively.

A general strategy for the design of asymmetric cascade reactions using readily available halides and carbon monoxide (CO) as substrates is developed. The key is the catalytic generation of C1-ammonium enolates for the subsequent asymmetric cascade reactions through the combination of palladium-catalyzed carbonylation and chiral Lewis base catalysis. Utilizing this strategy, we have established asymmetric formal [1+1+4] and [1+1+2] reactions to afford chiral dihydropyridones and β-lactams with high yields and high enantio- and diastereoselectivities.

Background The biological production of 2,3-butanediol from xylose-rich raw materials from Klebsiella pneumoniae is a low-cost process. RpoD, an encoding gene of the sigma factor, is the key element in global transcription machinery engineering and has been successfully used to improve the fermentation with Escherichia coli. However, whether it can regulate the tolerance in K. pneumoniae remains unclear. Results In this study, the kpC mutant strain was constructed by altering the expression quantity and genotype of the rpoD gene, and this exhibited high xylose tolerance and 2,3-butanediol production. The xylose tolerance of kpC strain was increased from 75 to 125 g/L, and the yield of 2,3-butanediol increased by 228.5% compared with the parent strain kpG, reaching 38.6 g/L at 62 h. The RNA sequencing results showed an upregulated expression level of 500 genes and downregulated expression level of 174 genes in the kpC mutant strain. The pathway analysis further showed that the differentially expressed genes were mainly related to signal transduction, membrane transport, carbohydrate metabolism, and energy metabolism. The nine most-promising genes were selected based on transcriptome sequencing, and were evaluated for their effects on xylose tolerance. The overexpression of the tktA encoding transketolase, pntA encoding NAD(P) transhydrogenase subunit alpha, and nuoF encoding NADH dehydrogenase subunit F conferred increased xylose consumption and increased 2,3-butanediol production to K. pneumoniae. Conclusions These results suggest that the xylose tolerance and 2,3-butanediol production of K. pneumoniae can be greatly improved by the directed evolution of rpoD. By applying transcriptomic analysis, the upregulation of tktA, pntA, and nuoF that were coded are essential for the xylose consumption and 2,3-butanediol production. This study will provide reference for further research on improving the fermentation abilities by means of other organisms. Electronic supplementary material The online version of this article (10.1186/s13068-018-1312-8) contains supplementary material, which is available to authorized users.