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Abstract African swine fever virus (ASFV) is the causal agent of African swine fever (ASF), which is contagious and highly lethal to domestic pigs and wild boars. The genome of ASFV encodes many proteins important for ASFV life cycle. The functional importance of topoisomerase AsfvTopII has been confirmed by in vivo and in vitro assays, but the structure of AsfvTopII is poorly studied. Here, we report four AsfvTopII complex structures. The ATPase domain structures reveal the detailed basis for ATP binding and hydrolysis, which is shared by AsfvTopII and eukaryotic TopIIs. The DNA-bound structures show that AsfvTopII follows conserved mechanism in G-DNA binding and cleavage. Besides G-DNA, a T-DNA fragment is also captured in one AsfvTopII structure. Mutagenesis and in vitro assays confirm that Pro852 and the T-DNA-binding residue Tyr744 are important for the function of AsfvTopII. Our study not only advances the understanding on the biological function of AsfvTopII, but also provides a solid basis for the development of AsfvTopII-specific inhibitors.

Abstract Mpox virus (MPXV) can cause mpox in humans. Due to its quick and wide spread in the past two years, mpox has turned into a significant public health concern. Helicase E5 is a multi-domain protein; its primer synthesis and DNA unwinding activity are required for genome uncoating and DNA replication of MPXV. However, the in vitro DNA unwinding activity has never been demonstrated. Here, we report the structural and biochemical studies of MPXV E5, showing that the full-length protein adopts an auto-inhibited conformation. Truncation of the N-terminus can recover the in vitro unwinding activity of E5 towards the forked DNA. Further structural analysis reveals that MPXV E5 shares a conserved mechanism in DNA unwinding and primer synthesis with the homologous proteins. These findings not only advance our understanding on the function of MPXV E5, but also provide a solid basis for the development of anti-poxvirus drugs.

This study was designed to develop a 30 m resolution land cover dataset to improve the performance of regional weather forecasting models in East China. A 10-class land cover mapping scheme was established, reflecting East China’s diverse landscape characteristics and incorporating a new category for plastic greenhouses. Plastic greenhouses are key to understanding surface heterogeneity in agricultural regions, as they can significantly impact local climate conditions, such as heat flux and evapotranspiration, yet they are often not represented in conventional land cover classifications. This is mainly due to the lack of high-resolution datasets capable of detecting these small yet impactful features. For the six-province study area, we selected and processed Landsat 8 imagery from 2015–2018, filtering for cloud cover. Complementary datasets, such as digital elevation models (DEM) and nighttime lighting data, were integrated to enrich the inputs for the Random Forest classification. A comprehensive training dataset was compiled to support Random Forest training and classification accuracy. We developed an automated workflow to manage the data processing, including satellite image selection, preprocessing, classification, and image mosaicking, thereby ensuring the system’s practicality and facilitating future updates. We included three Weather Research and Forecasting (WRF) model experiments in this study to highlight the impact of our land cover maps on daytime and nighttime temperature predictions. The resulting regional land cover dataset achieved an overall accuracy of 83.2% and a Kappa coefficient of 0.81. These accuracy statistics are higher than existing national and global datasets. The model results suggest that the newly developed land cover, combined with a mosaic option in the Unified Noah scheme in WRF, provided the best overall performance for both daytime and nighttime temperature predictions. In addition to supporting the WRF model, our land cover map products, with a planned 3–5-year update schedule, could serve as a valuable data source for ecological assessments in the East China region, informing environmental policy and promoting sustainability.

With the demand for communication, imaging, spectroscopy, and other applications, broadband detection has always been a particularly popular direction. However, the current photodetectors have the problems of relatively narrow response bands, a low sensitivity, a slow response speed, and complex manufacturing processes. In this article, the alloy material InBiSe3 is proposed to manufacture a wideband photodetector from visible to terahertz at room temperature. The noise equivalent power (NEP) of the detector is 1.37 × 10−10 W Hz−1/2 at 635 nm, 1.2 × 10−10 W Hz−1/2 at 808 nm, and 1.56 × 10−10 W Hz−1/2 at 980 nm. The device also exhibits a good response in the terahertz and millimeter-wave bands, with a NEP of 8.33 × 10−15 W Hz−1/2 at 0.023 THz, 7.03 × 10−14 W Hz−1/2 at 0.14 THz, 6.14 × 10−15 W Hz−1/2 at 0.171 THz, 1.91 × 10−14 W Hz−1/2 at 0.35 THz, and 4.04 × 10−14 W Hz−1/2 at 0.5 THz based on the electromagnetic induced potential wells effect. The response time is as fast as 10 µs. Our results demonstrate the promise of the InBiSe3 alloy for photoelectric applications and provide a method for the high performance of broadband photodetectors.

Crystal structures of M. tuberculosis elongation factors EF-Tu and EF-Ts in complex and GDP-bound Ef-Tu reveal the molecular basis of EF-Tu’s representative recycling and inactive forms in protein translation.

Abstract Objective Men who have sex with men (MSM) living with HIV are more likely to suffer from mental health problems. They should be given adequate attention to treat and improve their mental health disorders. This meta-analysis aimed to assess whether psychosocial interventions reliably improve psychological well-being among MSM living with HIV. Method Cochrane Library, EMBASE, PsycINFO, and PubMed were searched for psychosocial intervention randomized controlled trials evaluating mental health (e.g., depression, anxiety, self-efficacy). The effect size was pooled using the random-effects model, and continuous outcomes were reported using standardized mean difference (SMD) values . Results A total of 12 studies including 1782 participants were included in the meta-analysis. Psychosocial interventions in contrast to control groups significantly reduced depression (SMD, − 0.28; 95% CI − 0.52 – − 0.03) at the follow-up assessment and improved quality of life (SMD 0.43, 95% CI 0.23–0.63) after treatment. Psychosocial interventions also had a significant effect on measures of self-efficacy (SMD 2.22, 95% CI 0.24–4.20), and this effect was sustained until long-term follow-up (SMD 0.55, 95% CI 0.02–1.08). Subgroup analyses revealed that improvements in depression were more significant when participants possessed higher education and treatment providers used cognitive behavioral therapy (CBT). Conclusions The findings of this study indicate that psychosocial interventions benefit the mental health of MSM living with HIV. It is necessary to conduct more research to explore characteristics that may affect treatment outcomes in the future. Trial registration This research was prospectively registered in PROSPERO ( CRD42021262567 ).

Purpose: To investigate the baseline levels of serotype-specific IgG antibodies to Streptococcus pneumoniae (S. pneumoniae) and assess their impact on the assessment of vaccine immunogenicity. Methods: We used a subset of serum samples from a randomized controlled trial. The blood of 584 healthy participants was collected on day 0 before and day 28 after the 23-valent pneumococcal polysaccharide vaccine (PPSV23) vaccination. Serotype-specific IgG against PPSV23-covered serotypes were measured by the World Health Organization (WHO) reference enzyme-linked immunosorbent assay (ELISA). Vaccine immunogenicity was compared using conversion rates (proportion of participants with IgG levels following immunization that are 2-fold greater than the baseline) and geometric mean fold rises (GMFRs) between the two groups, which were grouped according to pre-vaccination (baseline) IgG antibody levels. Results: Our data showed that over half of individuals have baseline IgG levels for 15 out of 23 serotypes above 1.3 µg/mL, and geometric mean concentrations (GMCs) were generally higher in the elderly group and the female group; significant differences were found in 15 serotypes for vaccine immunogenicity based on the seroconversion rate or GMFRs between individuals with baseline IgG ≥ 1.3 µg/mL and individuals with baseline IgG < 1.3 µg/mL. The seroconversion rate decreased with the increase of baseline IgG levels according to a linear regression model. Conclusions: The assessment of vaccine immunogenicity could be impacted by the fact that many adults had high baseline antibody levels. This study is registered in the Chinese Clinical Trial Registry, number NCT05298800.

HARP are member of protein-only RNase P, which catalyzes pre-tRNA 5’-end processing and maturation. Here, the authors present crystal structure and provide mechanistic insights into pre-tRNA binding and cleavage by HARP proteins.

Abstract Owing to its great threat to human health and environment, Pb2+ pollution has been recognized as a major public problem by the World Health Organization (WHO). Many DNA aptamers have been utilized in the development of Pb2+-detection sensors, but the underlying mechanisms remain elusive. Here, we report three Pb2+-complexed structures of the thrombin binding aptamer (TBA). These high-resolution crystal structures showed that TBA forms intramolecular G-quadruplex and Pb2+ is bound by the two G-tetrads in the center. Compared to K+-stabilized G-quadruplexes, the coordinating distance between Pb2+ and the G-tetrads are much shorter. The T3T4 and T12T13 linkers play important roles in dimerization and crystallization of TBA, but they are changeable for Pb2+-binding. In combination with mutagenesis and CD spectra, the G8C mutant structure unraveled that the T7G8T9 linker of TBA is also variable. In addition to expansion of the Pb2+-binding aptamer sequences, our study also set up one great example for quick and rational development of other aptamers with similar or optimized binding activity.

Infection of human parvovirus B19 (B19V) can cause a variety of diseases, such as hydrops fetalis, erythema infectiosum in children and acute arthropathy in women. Although B19V infection mainly occurs during childhood, about 50 % of adults are still susceptible to B19V infection. As the major replication protein of B19V, deletion of NS1 completely abolishes the infectivity of the virus. The nuclease domain of NS1 (NS1_Nuc) is responsible for DNA Ori binding and nicking that is critical for B19V viral DNA replication. NS1 has various variants, the structure and function for the majority of the variants are poorly studied. Here, we report two high-resolution crystal structures of NS1_Nuc, revealed the detailed conformations of many key residues. Structural comparison indicates that these residues are important for ssDNA or dsDNA binding by NS1. NS1 belongs to the HUH-endonuclease superfamily and it shares conserved ssDNA cleavage mechanism with other HUH-endonuclease members. However, our structural analyses, mutagenesis and in vitro assay results all suggested that NS1_Nuc utilizes one unique model in ssDNA binding.

BackgroundIn recent years, the incidence of syphilis has increased year by year. Our study is to explore the risk factors for the development of neurosyphilis in patients who failed syphilis treatment.MethodsA total number of 165 patients with complete medical records and who agreed to undergo lumbar puncture were divided into 47 neurosyphilis cases and 118 non-neurosyphilis cases according to the diagnostic criteria of neurosyphilis, and the differences in clinical characteristics and laboratory features between the two groups were analyzed. Significant variables were entered into multivariable logistic regression models.Results(1) There were statistical differences (p < 0.05) between the neurosyphilis (NS) group and the non-neurosyphilis (NNS) group in terms of the higher proportion of male and serum rapid plasma reagin (RPR) > 1:32 and the elevated cerebrospinal fluid white blood cell (CSF WBC) and CSF protein in the neurosyphilis group compared with the non-neurosyphilis group. (2) Male gender, serum RPR titers >1:32 at lumbar puncture, CSF WBC >8 × 106/L were significantly associated with neurosyphilis.ConclusionFor patients who have failed syphilis treatment, lumbar puncture should be performed to exclude neurosyphilis, to enable early diagnosis and treatment, and to prevent irreversible damage of neurosyphilis, especially if the patient is male and has a serum RPR>1:32 and elevated CSF WBC at lumbar puncture, which are risk factors for neurosyphilis.

Abstract Ultrabroadband photodetection is of great significance in numerous cutting‐edge technologies including imaging, communications, and medicine. However, since photon detectors are selective in wavelength and thermal detectors are slow in response, developing high performance and ultrabroadband photodetectors is extremely difficult. Herein, one demonstrates an ultrabroadband photoelectric detector covering visible, infrared, terahertz, and millimeter wave simultaneously based on single metal–Te–metal structure. Through the two kinds of photoelectric effect synergy of photoexcited electron–hole pairs and electromagnetic induced well effect, the detector achieves the responsivities of 0.793 A W−1 at 635 nm, 9.38 A W−1 at 1550 nm, 9.83 A W−1 at 0.305 THz, 24.8 A W−1 at 0.250 THz, 87.8 A W−1 at 0.172 THz, and 986 A W−1 at 0.022 THz, respectively. It also exhibits excellent polarization detection with a dichroic ratio of 468. The excellent performance of the detector is further verified by high‐resolution imaging experiments. Finally, the high stability of the detector is tested by long‐term deposition in air and high‐temperature aging. The strategy provides a recipe to achieve ultrabroadband photodetection with high sensitivity and fast response utilizing full photoelectric effect.

Objectives: To investigate the acceptability of human papillomavirus (HPV) vaccination among men who have sex with men (MSM) and its associated factors.Methods: We searched studies written in English in PubMed, EMBASE, and Web of Science with no geographical or time restrictions. We evaluated the quality of the included literature. We calculated the pooled acceptability and performed meta-analysis of selected studies, including factors associated with the acceptability among MSM, using Review Manager (v5.3).Results: The acceptability among the 15 studies (n = 8,658) was 50% (95% CI: 0.27–0.72). The meta-analysis of seven articles (n = 4,200) indicated that having a college or higher degree (OR = 1.62, 95% CI: 1.35–1.95), disclosure of sexual orientation to healthcare professionals (HCPs; OR = 2.38, 95% CI: 1.47–3.86), vaccination with at least one dose for hepatitis A or B (OR = 2.10, 95% CI: 1.42–3.10), awareness of HPV (OR = 1.85, 95% CI: 1.21–2.83), knowledge of HPV (SMD = 0.28, 95% CI: 0.16–0.39), perceived susceptibility to HPV infection (SMD = 0.31, 95% CI: 0.11–0.50), and perceived severity of HPV-related disease (SMD = 0.40, 95% CI: 0.28–0.51) can promote acceptance of HPV vaccines. Meanwhile, people who have had unprotected anal sex or have more sex partners tend to have low acceptance of HPV vaccines.Conclusions: HPV education should be actively promoted according to the factors that influence the acceptability of HPV vaccines among the MSM population. HPV education should be especially aimed at people with low academic qualifications and people with risky sexual behaviors, and should emphasize the aspects of susceptibility to and severity of HPV-related disease. More intervention trials should be conducted to increase the credibility of the results.

Syphilis is an important health problem worldwide; however, few studies have probed the impact of syphilitic infection on T cell turnover. The mechanisms behind the frequency of T cell subset changes and the associations between these subsets during syphilitic infection remain unclear. Herein, we used a cell-staining method and flow cytometry to explore changes in T cell subpopulations and potential contribution of apoptosis and pyroptosis that triggered therein. We investigated caspase-1-mediated pyroptosis and caspase-3-mediated apoptosis of CD4 + and CD8 + T cells, the major effector lymphocytes with pivotal roles in the pathogenesis of infectious diseases. We found that the levels of caspase-1 and caspase-3 increased in both the circulation and intracellularly in CD4 + and CD8 + T cells. Caspase-1 showed a continual increase from early latent stage infection through to phase 2 disease, whereas caspase-3 increased through to phase 1 disease but declined during phase 2. In addition, serum levels and intracellular expression of caspase-1 and caspase-3 were positively correlated. Overall, this study increases our understanding of how syphilitic infection influences CD4 + and CD8 + T-cell turnover, which may help with designing novel and effective strategies to control syphilis infection and prevent its transmission.

The DNA ligase of African swine fever virus is one of the most error-prone ligases identified to date, but underlying molecular details are lacking. Here, Chen et al. report four AsfvLIG:DNA structures and identify a unique N-terminal domain and four unique active site residues that are crucial for its catalytic efficiency.

Current-controlled negative differential resistance (CC-NDR) phenomenon attracts a lot of interest for fabricating the access devices of nonvolatile memory based on crossbar array architectures. However, simple, bipolar, two-terminal commercial devices that exhibit CC-NDR are currently lacking because a number of critical characteristics needed to be met for such application. Here, we report the CC-NDR observed in Mn1.56Co0.96Ni0.48O4 (MCNO)- a small-polaron hopping material. Our experimental data and simulation reveal that the CC-NDR arises from self-heating effect due to the nature of strong electron-phonon coupling in small-polaron hopping system. The reported CC-NDR exhibits adjustable threshold voltage from 10-3 to 102 V, on-state current from 105 to 108 A/cm2 and off-state current is as low as ∼10 A/cm2 depending on device dimensions, thermal isolation condition, environmental temperature and activation energy of material. Uniquely, unlike in NbO2, Nb2O5, TiO2, TaOx et. al. materials, the CC-NDR in MCNO is more stable and reliable, because it does not undergo any electroforming process. These traits make MCNO a very potential candidate for CC-NDR devices.

The incidence of syphilis has increased dramatically in men who have sex with men (MSM), especially those with HIV-1 infection. Treponema pallidum and HIV-1 are bidirectionally synergistic, accelerating disease progression reciprocally in co-infected individuals. We have shown that monocytes have different effects on T helper cells at different stages of HIV-1 infection. However, the immunological changes in the three monocyte subsets and in regulatory T cells (Tregs), and the associations between these cell types during syphilis infection among HIV-1-infected MSM remain unclear. Herein, we used cell staining methods to explore changes in monocyte subsets and Tregs and any associations between these cells. We found that the frequency of classical monocytes was higher in the rapid plasma reagin (RPR+) group than in the healthy controls (HCs) and the chronic HIV-1 infection (CHI) plus RPR+ (CHI&RPR+) group. The frequencies of Foxp3+CD25+CD45RA+ and Foxp3+Helios+CD45RA+ Tregs were significantly higher in the RPR+, CHI, and CHI&RPR+ groups than in HCs, whereas the frequency of CD45RA+ Tregs was lower in the CHI&RPR+ group than in CHI group. The frequencies of Foxp3+CD25+CD45RO+ and Foxp3+Helios+CD45RO+ Tregs were lower in the RPR+, CHI, and CHI&RPR+ groups than in HCs. The frequency of intermediate monocytes was inversely correlated with the frequency of CD45RA+ Tregs and positively correlated with the frequency of CD45RO+ Tregs. These results demonstrate for the first time that intermediate monocytes control the differentiation of Treg subsets in Treponema pallidum/HIV-1 co-infections. These findings provide new insights into an immunological mechanism involving monocytes/Tregs in HIV-infected individuals with syphilis.

For the first time, we present the spectra of all three components of the refractive index and absorption coefficient of the KTiOAsO4 (KTA) crystal measured by the means of terahertz time-domain spectroscopy in the range of 0.3–2.1 THz. The dispersion of the refractive index is approximated and presented in the form of the Sellmeier equation. We observe a large birefringence ΔnZ-X ≈ 0.76 and dichroism which is attributed to a strong absorption peak in the vicinity of ~1.23–1.25 THz for the Z-axis. However, the crystal can be considered as almost uniaxial due to a close value of nX and nY as well as αX ≈ αY in the region below 0.5 THz. Moreover, KTA crystals can satisfy the phase-matching condition in principal XZ-plane for THz emission on difference frequency generation mechanism. Therefore, the crystal could be considered as an efficient candidate for terahertz wave generator under intense laser pump.

In order to solve problems such as operation and control in the process of chemical experiment in teaching, using the technology of digitized computer at present, the operation steps, materials, speed, control and reaction of chemical experiments can be directly and accurately displayed on the video screen in the form of two-dimensional animation. This technology has made it skillfully restore the chemical experiment scenes in the training room, reduce the labor intensity of the experimenters, and improve the accuracy of the chemical experiment, hoping to make certain contributions to the research of chemical experiments. In this paper, the shortcomings of traditional chemical experiments are compared. The design of computer animation and the implementation of chemical experiments are expounded, based on vector graphics and made by Flash MX software. It is feasible to use computer two-dimensional animation to show chemical experiments. It has revolutionized the methods of chemical experimental research, made the research of chemical experiments more digitalized, and is worth popularizing.

With the development of industrialization, the surrounding areas of the city gradually become the important chemical industry bases, which have made important contributions to the economic development of the city. However, there are also some safety risks in the process of production, storage and transportation for chemical products. Once hazardous gas leaks, it will not only cause pollution of the environment, but also harm the health of people and animals. In order to deal with leakage incidents in time, many chemical enterprises have already built their own real-time monitoring system. However, most of these platforms are only for real-time monitoring within the enterprise, and can not meet the needs of the city's overall monitoring for hazardous gases. Fourier Transform Infrared (FTIR) is a comprehensive monitoring technology developed rapidly in recent years, which is widely used in the emergency monitoring of pollution source gas. In this paper, a large area dangerous chemical gas monitoring platform is proposed by using the technology of Solar Occultation Flux (SOF-FTIR). First of all, this paper briefly introduces the gas monitoring technology. What is more, the principal component analysis (PCA) in FITR technology is described in detail. Secondly, in view of the large amount of noise in the infrared spectrum data, an improved threshold denoising method is proposed by introducing the correction coefficient. Compared with traditional FTIR, SOF-FTIR can monitor hazardous chemical gas in a wider area, and has better mobility. Finally, the simulation results show that the improved denoising algorithm has better performance. Theoretically, the real-time monitoring platform for urban hazardous gas based on SOF-FTIR can effectively monitor the leakage of hazardous gas in cities.

A rapidly escalating outbreak of syphilis infection has been affected men who have sex with men, particularly those with HIV-1 infection. γδ T cells are unconventional immune cells with two main subsets, Vδ1 T cells and Vδ2 T cells, which possess a combination of innate and adaptive immune features allowing them against HIV-1. However, whether syphilis infection affects the phenotype and function of γδ T cells in HIV-1-infected patients remains unclear, especially in acute HIV-1 infection (AHI). In this study, we enrolled 57 HIV-1-infected patients (24 with HIV-1 infection only and 33 coinfected with syphilis) from an acute HIV-1-infected cohort in Beijing (PRIMO). A comprehensive analysis of γδ T-cell phenotype and function was performed by flow cytometry. We found syphilis coinfection could reverse the imbalance of Vδ1/Vδ2 ratio in AHI. Syphilis infection results in decreased γδ T-cell activation in AHI, but increased γδ T-cell activation in chronic HIV-1 infection (CHI). Moreover, patients with CHI had larger numbers of IL-17-producing γδ T cells than those with AHI, regardless of syphilis status. Thus, syphilis affected the γδ T-cell immune response differently in patients depending on the stages of HIV-1 disease. In addition, the percentage of IL-17-producing γδ T cells was positively correlated with the percentage of neutrophils. These results suggest that the γδ T-cell/IL-17/neutrophil axis is involved in HIV-1 pathogenesis and disease progression. Taken together, our observations provide new insight into the roles of γδ T cells in immunopathogenesis of syphilis and HIV-1 coinfection, particularly during AHI, and our findings may be helpful for the prevention of syphilis and other sexually transmitted infections and highlight the great significance on the remedy of patients coinfected with HIV-1.

African swine fever virus (ASFV) can cause highly lethal disease in pigs and is becoming a global threat. ASFV DNA Polymerase X (AsfvPolX) is the most distinctive DNA polymerase identified to date; it lacks two DNA-binding domains (the thumb domain and 8-KD domain) conserved in the homologous proteins. AsfvPolX catalyzes the gap-filling reaction during the DNA repair process of the ASFV virus genome; it is highly error prone and plays an important role during the strategic mutagenesis of the viral genome. The structural basis underlying the natural substrate binding and the most frequent dG:dGTP misincorporation of AsfvPolX remain poorly understood. Here, we report eight AsfvPolX complex structures; our structures demonstrate that AsfvPolX has one unique 5'-phosphate (5'-P) binding pocket, which can favor the productive catalytic complex assembly and enhance the dGTP misincorporation efficiency. In combination with mutagenesis and in vitro catalytic assays, our study also reveals the functional roles of the platform His115-Arg127 and the hydrophobic residues Val120 and Leu123 in dG:dGTP misincorporation and can provide information for rational drug design to help combat ASFV in the future.

Dihydrocumic acid was prepared from β-pinene through oxidation and dehydration. Then, ten oxime esters from dihydrocumic acid were synthesized. Reaction conditions of the oxime esters were adjusted and their structures were characterized by IR, 1H-NMR, MS, and elemental analysis. The antibacterial activity of these newly synthesized oxime esters against Gram-negative bacteria and Gram-positive bacteria was also investigated using the inhibition zone method. The preliminary results indicated that seven compounds displayed better antibacterial activity against Gram-negative bacteria compared with bromogeramine, a commercially available antibacterial agent.

This paper reports on the synthesis of a series of amide derivatives from acrylopimaric acid (APA). The derivatives contained aromatic groups and were characterized by IR, 1HNMR, MS, and elemental analysis. The antibacterial activity of the derivatives against Gram-negative bacteria and Gram-positive bacteria were also investigated. When compared with the other derivatives, compounds 3a and 3f showed much higher activity against Escherichia coli (Gram-negative bacteria) with inhibition zones of 5 mm and 5.5 mm, respectively. Structure-activity relationship analysis revealed that ortho-substituted phenyl derivatives and meta-substituted phenyl derivatives exhibited higher activity than the para-substituted derivatives. Meanwhile, the halogen-substituted compounds did not show visible antibacterial activity compared with other compounds, which may have been caused by the lower electron density of the halogen-substituted phenyl rings.

Turpentine is a volatile component of resin, which is an abundant forest resource in Southern China. As one of the most important components, the integrated application of β-pinene has been studied. The broad-spectrum evaluation of β-pinene and its analogues has, therefore, been necessary. In an attempt to expand the scope of agro-activity trials, the preparation and the evaluation of the herbicidal activity of a series of β-pinene analogues against three agricultural herbs were carried out. In accordance with the overall herbicidal activity, it is noteworthy that compounds 6k, 6l, and 6m demonstrated extreme activity with IC50 values of 0.065, 0.065, and 0.052 mol active ingredients/hectare against E. crus-galli. The preliminary structure–activity relationship (SAR) was analyzed and the compounds with the appropriate volatility and substituent type that had beneficial herbicidal activity were analyzed. Simultaneously, the quantitative structure–activity relationship (QSAR) model was built and the most important structural features were indicated, which was, to a certain extent, in line with the SAR study. The study aimed to study the application of the forest resource turpentine in agriculture as a potential and alternative approach for comprehensive utilization.

Co-infection with hepatitis C virus (HCV) has become the most common cause of death in human immunodeficiency virus (HIV) infected patients on antiretroviral therapy. The distribution of HCV genotypes varies with geographical regions and time, and limited studies have focused on the HCV genotype in HIV/HCV co-infection.The distribution of HCV genotypes was evaluated in 414 patients with HIV/HCV co-infection in three regions (South, Central and Northwest) of China from 2008 to 2010. The NS5B region of HCV was characterized using nested reverse transcription polymerase chain reaction. Nucleotide sequences obtained were subjected to phylogenetic analysis, and genotypes were assigned using published reference genotypes.Genotype 3 was the most prevalent HCV strain (36.2%), followed by genotype 6 (30.0%), genotype 1 (28.5%), genotype 2 (5.1%), and genotype 5 (0.2%). The distribution varied geographically. Genotype 6 (37.6%) was the predominant strain while genotype 1 (20.2%) was less common in the South compared to the Central and Northwest regions (all P < 0.001). The distribution also varied temporally. There was no significant difference in genotype distribution in Guangdong (a province in the South region), between patient cohorts from 2005-2008 and 2009-2010. However, outside Guangdong, genotypes 3 and 6a became significantly more prevalent (22.4% vs.42.2%, P< 0.001; 8.0% vs. 19.8%, P = 0.004), and genotype 1 less prevalent (54.4% vs.26.6%, P< 0.001) over time.The most dramatic shift in genotypic distribution was the movement of HCV genotypes 3 and 6a outside of Guangdong in HIV/HCV co-infected patients. This movement appeared closely associated with transmission via injected drug use.

Thin films of Mn1.95Co0.77Ni0.28O4are deposited on amorphous Al2O3 substrate by the magnetron sputtering method with the thickness of 6.5 μm. The effects of annealing treatment are studied on the film structural performance as well as the entropy of Mn-Co-Ni-O(MCNO) films by annealed at 400 ∘C, 500 ∘C, 600 ∘C, 700 ∘C, 800 ∘C respectively. It shows that the crystallinity of the thin film is the best annealed at 700 ∘C and the entropy is the largest because the number of different kinds of ions belonging to the same element equals with each other. After 800 ∘C annealing, the film resistivity is the minimal with the maximal entropy which means the highest stability.

The title compound, C23H38O2, a tetracyclo[10.2.2.01,10.04,9] hexadecane structure, crystallized with four independent molecules in the asymmetric unit. In the crystal, these independent molecules are linked by O—H...O hydrogen bonds, forming a polymeric chain propagating in [100]

In consideration of the fact that the α-methylene-γ-butyrolactone moiety is a major bio-functional group in the structure of carabrone and possesses some agricultural biological activity, forty-six new ester and six new ether derivatives containing α-methylene-γ-butyrolactone moieties were synthesized, and their fungicidal activities against Colletotrichum lagenarium and Botrytis cinerea were investigated. Most of the synthesized compounds showed moderate to significant fungicidal activity. Among them, halogen atom-containing derivatives showed better activity than others, especially compounds 6a,d which exhibited excellent fungicidal activity against C. lagenarium, with IC50 values of 7.68 and 8.17 μM. The structure-activity relationship (SAR) analysis indicated that ester derivatives with electron-withdrawing groups on the benzene ring showed better fungicidal activity than those with electron-donating groups. A quantitative structure-activity relationship (QSAR) model (R2 = 0.9824, F = 203.01, S2 = 0.0083) was obtained through the heuristic method. The built model revealed a strong correlation of fungicidal activity against C. lagenarium with the molecular structures of these compounds. These results are expected to prove helpful in the design and exploration of low toxicity and high efficiency α-methylene-γ-butyrolactone-based fungicides.

The preparation of bioactive derivatives from the renewable natural product pinene is a hot research topic in the deep processing and utilization of pinene. In this study, β-pinene was used to develop novel molecules as a promising new precursor of insecticide. A series of amide-containing derivatives of β-pinene were synthesized and characterized. The insecticidal activities of these derivatives against Mythimna separate and Semiaphis heraclei were tested. The structure characterization results showed that the characterization data of amide-containing derivatives were in full agreement with their proposed structures. The insecticidal activities evaluation results indicated that amide-containing derivatives exhibited weak insecticidal activity against Mythimna separate, but exhibited moderate to good insecticidal activity against Semiaphis heraclei. After testing for 72 h, the corrected mortality against Semiaphis heraclei of compounds 5c, 5e, 5f, 5 h, 5j, and 5 m was 100% at 1000 mg/L. The structure-activity relationship analysis results showed that the introduction of an amide group into the structure of derivatives improved their insecticidal activity against Semiaphis heraclei. Meanwhile, the amide-containing derivatives containing the F and NO2 substituted benzene ring might improve their insecticidal activity against Semiaphis heraclei. This study will be helpful for the high value-added utilization of the natural renewable resource β-pinene and the development of novel insecticides. [ABSTRACT FROM AUTHOR]

BACKGROUND: The use of fungicides to protect crops from diseases is an effective method, and novel environmentally friendly plant-derived fungicides with enhanced performance and low toxicity are urgent requirements for sustainable agriculture. RESULTS: Two kinds of rosin-based acylhydrazone compounds were designed and prepared. Based on the antifungal activity assessment against Rhizoctonia solani, Fusarium oxysporum, Phytophthora capsici, Sclerotinia sclerotiorum, and Botrytis cinerea, acylhydrazone derivatives containing a thiophene ring were screened and showed an inhibitory effect on rice R. solani. Among them, Compound 4n, with an electron-withdrawing group on the benzene ring structure attached to the thiophene ring, showed optimal activity, and the EC50 value was 0.981 mg L−1, which was lower than that of carbendazim. Furthermore, it was indicated that 4n could affect the mycelial morphology, cell membrane permeability and microstructure, cause the generation of reactive oxygen species in fungal cells, and damage the nucleus and mitochondrial physiological function, resulting in the cell death of R. solani. Meanwhile, Compound 4n exhibited a better therapeutic effect on in vivo rice plants. However, the induction activity of 4n on the defense enzyme in rice leaf sheaths showed that 4n stimulates the initial resistance of rice plants by removing active oxygen, thereby protecting the cell membrane or enhancing the strength of the cell wall. Through the quantitative structure–activity relationship study, the quantitative chemical and electrostatic descriptors significantly affect the binding of 4n with the receptor, which improves its antifungal activity. CONCLUSION: This study provides a basis for exploiting potential rosin-based fungicides in promoting sustainable crop protection. [ABSTRACT FROM AUTHOR]

The methyltransferase ribozyme SMRZ-1 utilizes S-adenosyl-methionine (SAM) and Cu (II) ions to methylate RNA. A comparison of the SAM-bound and unbound RNA structures has shown a conformational change in the RNA. However, the contribution of specific interactions and the role of a pseudotriplex motif in the catalytic center on the methylation reaction is not completely understood. In this study, we have used atomic substitutions and mutational analysis to investigate the reaction specificity and the key interactions required for catalysis. Substitution of the fluorescent nucleotide 2-aminopurine within the active ribozyme enabled the conformational dynamics of the RNA upon co-factor binding to be explored using fluorescence spectroscopy. We show that fast co-factor binding (t1/2 ~ 0.7 s) drives a conformational change in the RNA to facilitate methyl group transfer. The importance of stacking interactions at the pseudo-triplex motif and chelation of the Cu (II) ion were shown to be essential for SAM binding. [ABSTRACT FROM AUTHOR]

X-ray photoelectron spectroscopy was performed on Mn2-xCo2xNi1-xO4 (x=0.2, 0.4, 0.5, 0.6, and 0.8) series spinel films to determine their cation distributions. The results show that both Ni and Co ions exhibit bivalence, while Mn ions exhibit coexisting multivalence. The hopping frequency v0 of each sample was obtained by combining cation distribution results and electrical measurement data. Analysis of the divergence at Neel temperature between field cooling and zero-field cooling magnetization curves revealed that the ferromagnetic coupling between octahedral site ions first leads to spontaneous magnetization at TC, after which a second spontaneous magnetization arises from the antiferromagnetic couple between tetrahedral and octahedral sites at a lower temperature TN. The correlation between hopping conductivity and magnetic transition temperature is discussed. We propose that the strength of the ferromagnetic couple between octahedral sites is subject to the product term of Nc(1-c)v0, which determines the ferromagnetic transition temperature (TC) of the system. Our results provide an avenue to understand the origin of magnetic interaction in small-polaron hopping semiconductors. [ABSTRACT FROM AUTHOR]

Mn1.4Co1.0Ni0.6O4 (MCN) thin films are prepared by RF sputtering deposition method on amorphous Al2O3 substrate. Microstructure and X-ray photoelectron spectroscopy analyses suggest improvements in crystallinity and stoichiometry for MCN films with post-annealed process. Infrared (IR) optical constants of the MCN films are obtained by IR spectroscopic ellipsometer (SE) in the range of 1500 cm-1 to 3200 cm-1 (2.8-6.7 μm). The derived effective charge supports the increase of the oxidation after annealing. The dielectric function of the films is also extracted by SE in the range of 300-1000 nm adopting a double Lorentz model together with a Tauc-Lorentz model. The mechanism in electronic transition process is discussed based on the variation observed in the optical absorption spectra of the as-grown and post-annealed samples. The optical absorption peaks located at 1.7 eV, 2.4-2.6 eV, and 3.5-4 eV are attributed to the charge-transfer transitions of 2p electrons of oxygen ions and 3d electrons of Mn and Co ions. Our results are very important to understand the optoelectronic mechanism and exploit applications of metal oxides. [ABSTRACT FROM AUTHOR]

Chemical solution deposition method is used for preparing the serial films of [Mn.sub.2.52-x][Co.sub.x][Ni.sub.0.48][O.sub.4] with fixed Ni content of 0.48 on amorphous [Al.sub.2][O.sub.3] substrate. The electrical and magnetic measurements have shown that the thermal activation energy has decreased but the ferrimagnetic transition temperature has increased with the increase in Co content and the magnetization loop tests have shown that the serial films have possessed magnetic anisotropy with magnetically easy axis.