Search

Recent years have witnessed contrasting trends in summer total rainfall (STR) over the Tibetan Plateau (TP), with an increase in the northern and a decrease in the southern TP. This study identifies four significant centers of rainfall trends: eastern TP ("region A"), Qiangtang Plateau ("B"), Qaidam Basin ("C"), and the northern foothills of the Himalayas ("D"). Heavy rainfall dominates STR trends in regions A and D, accounting for 55.6% and 52.0%, respectively. In region B, moderate and light rainfall contribute almost equally, accounting for 37.3% and 44.8% of the STR trend, respectively. Region C is primarily influenced by light rainfall, explaining 71.2% of the STR trend. Notably, the contributions of different rainfall intensities to STR in each region vary annually, with region A experiencing more heavy rainfall, region B having moderate dominance but less light rainfall, and region C and D showing reduced and increased light rainfall contributions, respectively. Mechanistically, the strengthening of the upper-level westerly jet and the South Asian High, coupled with changes in moisture transport and convective available potential energy, collectively cause variations in rainfall intensity, characterizing the spatial heterogeneity in STR in the TP. [ABSTRACT FROM AUTHOR]

The characteristics of diurnal variation of the surface sensible heat flux (SH) over the Tibetan Plateau (TP) are comprehensively investigated by using the long-term dataset of integrated land–atmosphere interaction observations (2006–2016) on the TP. Results show that the diurnal variation of SH shows obvious seasonal variabilities in terms of amplitude, duration, and peak time. At the Muztagh Ata Westerly Observation and Research Station (MAWORS), the Ngari Desert Observation and Research Station (NADORS), and the Qomolangma Atmospheric and Environmental Observation and Research Station (QOMS), the SH diurnal amplitude is consistently the largest in spring, followed by summer and autumn, and the smallest in winter, with a peak at 15:00. However, for the Southeast Tibet Observation and Research Station (SETORS), the amplitude in winter is rather violent with the peak at 12:00. We find that positive SH at most stations has the longest duration from May to August. Moreover, the peak time fluctuates from month to month, even showing a shift at the QOMS before and after 2015, and the double-peak phenomenon of SH mainly occurs in spring and autumn. Additionally, magnitudes of calculated SH with the conventional heat transfer coefficient (CDH) of 0.004 are about 64% to 100% larger than those of directly observed SH at the QOMS and the Nam Co Monitoring and Research Station (NAMORS). We here additionally recommend a new CDH values of about 2.24 × 10−3 in spring and 2.78 × 10−3 in summer, respectively, to more accurately calculate the TP SH. [ABSTRACT FROM AUTHOR]

Objectives: An investigation of the effects of different types of the inferior mesenteric artery (IMA) on laparoscopic left colic artery (LCA) radical resection of rectal cancer was conducted. Methods: Clinical data were collected from 92 patients who underwent laparoscopic radical resection of rectal cancer with preservation of the LCA at Nantong University's Second Affiliated Hospital. All patients underwent full-abdominal dual-energy CT enhancement examination before surgery and 3D post-processing reconstruction of the IMA. Two radiologists with >3 years of experience in abdominal radiology jointly conducted the examination. A total of three types of IMA were identified among the patients: IMA type I (the LCA arising independently from the IMA), type II (LCA and sigmoid colon artery [SA] branching from a common trunk from IMA), and type III (LCA, SA, and superior rectal artery [SRA] branching from the IMA at the same point). The baseline data, pathological results, and intra-operative and post-operative indicators of the groups were analyzed. Results: The proportions of type I, type II, and type III IMA were 58.70% (54/92), 18.48% (17/92), and 22.82% (21/92), respectively. IMA typing was consistent with the preoperative CT evaluation results. The intra-operative blood loss of type III IMA patients [median (interquartile spacing), M (P25, P75): 52.00 (39.50, 68.50) ml] was higher than that of type I and II IMA patients [35.00 (24.00, 42.00) and 32.00 (25.50, 39.50) ml, respectively] (P<0.05). The incidence of anastomotic fistula in type III IMA patients (4 cases, 19.05%) was higher than that in non-type III IMA patients (1 case, 1.41%) (X2=6.679, P=0.010). The incidence of postoperative complications among the three types of IMA was not significantly different (P>0.05). Conclusions: Among rectal cancer patients undergoing laparoscopic LCA preservation, type III IMA patients had more intraoperative bleeding and a higher incidence of postoperative anastomotic fistula. However, this did not increase the risk of overall postoperative complications. Highlights: 1. DECT three-dimensional reconstruction can accurately evaluate the classification of IMA before operation. 2. The short-term outcome of Dixon surgery with LCA preservation is affected by the type of IMA presented. [ABSTRACT FROM AUTHOR]

In this work, a metal–glass joint between Ti and K9 glass was obtained by vacuum diffusion bonding after Ti was pre-oxidized at different temperatures to explore the effect of the pre-oxidation procedure on the properties of diffusion bonding joints. For the oxide layer, X-ray diffraction revealed that the oxide film consisted of TiO2 and some low-valence Ti–O compounds such as Ti6O, Ti3O, TiO, etc. The x/y ratio of TixOy decreased as oxidation temperature increased. Scanning and transmission electron microscopy showed that the morphology of the oxide layer gradually changed from dense to loose and porous, and the oxidized particle size gradually increased and distributed in layers from inside to outside, with the increase in temperature. From the results of diffusion bonding at 700 °C for 2 h, good Ti-K9 joints without cracks and pores can be obtained when the pre-oxidation temperature attained 900 °C. A transition layer appeared at the Ti-K9 interface with the diffusion of elements Ti, Si, and O, etc. Shear strength tests showed that the structure of the oxide layer at different conditions can directly affect the strength of the joint between Ti and glass. The joint to Ti pre-oxidized at 900 °C exhibited the highest shear strength, producing an average failure strength of 20.6 ± 1.2 MPa. An appropriate amount of oxide layer can improve the quality of the Ti-K9 joint. The feasibility of diffusion bonding added to process versatility for the use of Ti-K9 joint on practical application. [ABSTRACT FROM AUTHOR]

We investigated the effect of increased spring (April–May) dust aerosol over the Arabian Peninsula (AP) on the subseasonal-to-seasonal (S2S) variability of the Asian summer monsoon (ASM) using MERRA-2 re-analysis data (1980–2018). Result shows that abundant AP spring dust leads to more dust covering the AP and Pakistan northwestern India (PNWI) during May–June, causing a cooler land surface and a warmer lower and middle atmosphere with enhanced local atmospheric stability. However, the warmer atmosphere increases the meridional temperature gradient, boosting moisture transport from the Arabian Sea to PNWI, causing increased convective potential energy in PNWI region. As season advances, the accumulated convection potential energy eventually breaks through the local stability, via the elevated heat pump (EHP) effect, increasing precipitation over PNWI. In July and August, cloud radiation-circulation feedback further enhances the warming of the upper troposphere, strengthening precipitation in PNWI. Dynamical adjustments of large-scale circulations induced by the feedback strongly modulate ASM precipitation. Over southern and central China, precipitation is reduced, in conjunction with a contraction of South Asian High, and the development of an anomalous east-to-west oriented upper-level wavetrain in July. In August, the upper level wavetrain undergoes strong wave-mean flow interaction, culminating in the development of an anticyclonic center with drought conditions over northeast China, Korea and Japan. Over the Indian subcontinent, increased precipitation in PNWI plays an important role in initiating the EHP feedback leading to increased precipitation over the Indian subcontinent, and in modulating the jetstream-wave interaction in downstream East Asian regions in July–August. [ABSTRACT FROM AUTHOR]

Background: General practitioners (GPs) play a significant role in dementia care. However, the knowledge and attitudes of them towards dementia care are poorly characterized. The present study aimed to investigate GPs' knowledge, attitudes and skills of dementia care in primary health settings in Beijing. Methods: A cross-sectional survey was conducted in 27 community health service centers (CHSCs) in Beijing. The GPs' knowledge, attitudes and skills were assessed utilizing the Alzheimer's Disease Knowledge Scale (ADKS), Dementia Care Attitude Scale (DCAS) and self-designed questionnaire, respectively. Results: A total of 341 participants returned the questionnaire. The overall mean score of GPs' dementia knowledge measured by the ADKS was 21.42 (SD = 2.73) out of 30 (71.4%), GPs' attitudes to dementia care was 36.25 (SD = 5.12) out of 50 (72.5%), and GPs' self-confidence on dementia care skills was 53.93 (SD = 9.57) out of 75 (71.9%). GPs' overall knowledge towards dementia care was limited and the attitudes were generally positive. They had low level recognition of their roles towards dementia care. The majority of GPs believed that dementia care was within a specialist's domain not that of general practice. Conclusion: GPs demonstrate low levels of dementia knowledge and skills, but express generally positive attitudes towards dementia in this study. It is much needed to translate detailed dementia care handbook, and adequate dementia knowledge training for GPs into practice to improve care outcomes for people with dementia in China. In addition, dementia management should be covered in the national basic package of public health services in primary care. [ABSTRACT FROM AUTHOR]

We investigated the intraseasonal relationship between the atmospheric heat source over Tibetan Plateau (TP) and summer rainfall in eastern China. A quasi-biweekly oscillation (QBWO) is the common dominant periodicity over both the TP and eastern China. Crucially, the TP heat source QBWO leads rainfall QBWO over its downstream region by 2–8 days. The QBWO over the TP shows a significant eastward propagation. Phase composite further identified the specific propagation pathway: TP QBWO first propagates eastward to central China, southward to southern China, and then northeastward to the lower reaches of the Yangtze River with a zigzag propagating pathway. Mechanistically, the eastward propagation of the upper level divergence caused by the movement of the 200 hPa jet core and south Asian high contributes to the eastward propagation of the rainfall QBWO. Simultaneously, the eastward (westward) shift in the western north Pacific subtropical high causes deepening (flattening) of the monsoon trough and the occurrence of an anomalous cyclone (anticyclone) over the western north Pacific. An anomalous anticyclonic (cyclonic) circulation around the TP appears with the wet-to-dry (dry-to-wet) phase transition of the TP QBWO. Together, they play a crucial part in the southward (northeastward) movement of the QBWO. Further dynamic analysis indicates that the horizontal moisture advection acts on the whole eastward-propagating process of the QBWO, whereas the horizontal vorticity advection is only significant when QBWO is over the TP. This study shows that the fluctuations in TP heat source are important indicators in extended forecasts of summer rainfall in eastern China. [ABSTRACT FROM AUTHOR]

• The use of SMS as a hydrophobic modifier for geopolymers is an economical method. • The modification method is simple and suitable for large-scale industrial applications. • High modification efficiency is at a small dosage: from 0° to 134.5° at 1.5 wt%. • The effects of SMS on geopolymers were analyzed using FT-IR, XRD, and SEM. • SMS improved the densification and erosion resistance of geopolymers. In this paper, the geopolymers were modified by simply blending with sodium methyl-silicate (SMS). Furthermore, the effects of SMS on the structure, micromorphology, physical properties and erosion resistance of geopolymers were investigated. The results showed that the addition of SMS can greatly increase the hydrophobicity of the geopolymer. The contact angle reached a maximum of 134.5°with 1.5 wt% addition. Moreover, due to the optimization of the atomic arrangement of the geopolymer caused by the addition of SMS, the property change of the geopolymer was presented as follows: (1) the denseness was enhanced; (2) the hardness, friction resistance and erosion resistance were improved. [ABSTRACT FROM AUTHOR]

Summary: A coexpression network is a powerful tool for revealing genes' relationship with many biological processes. Mass transcriptomic and genomic data from different plant species provide the foundation for understanding the evolution of nodulation across the Viridiplantae at a systematic level.We used weighted coexpression network analysis (WGCNA) to mine a nodule‐related module (NRM) in Glycine max.Comparative genomic analysis of 78 green plant species revealed that NRM genes are recruited from different evolutionary nodes along with gene duplication events. A set of core coexpressed genes within legumes may play vital roles in regulating nodule environments essential for nitrogen fixation, including oxygen concentrations, sulfur transport, and iron homeostasis (such as GmCHY). The regulation of these genes occurred mainly at the transcription level, although some of them, such as sulfate transporters, may also undergo positive selection at protein level.We revealed that ancient orthologs and duplication events before the origin of legumes were preadapted for symbiosis. Conserved coregulated genes found within legumes paved the way for nodule formation and nitrogen fixation. These findings provide significant insights into the evolution of nodulation and indicate promising candidates for identifying other key components of legume nodulation and nitrogen fixation. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRs) serve important roles in the development of various types of human cancer, including nasopharyngeal carcinoma (NPC). In the present study, the expression levels of miR-663b in NPC were investigated and its role and underlying mechanisms were examined. Reverse transcription-quantitative polymerase chain reaction was performed to assess miR-663b expression levels in NPC tissues and C666-1 cells. TargetScan was applied to predict the putative targets of miR-663b and the dual luciferase reporter assay was used to confirm the predictions. To investigate the role of miR-663b in NPC, the NPC C666-1 cell line was transfected with miR-663b mimics, miR-663b inhibitors or negative control. The Cell Counting kit-8 assay was performed for cell proliferation detection and western blot analysis was applied to determine the expression levels of epithelial mesenchymal transition (EMT)-associated proteins. Results indicated that when compared with the adjacent normal tissues and the normal nasopharyngeal epithelial cells, miR-663b expression levels were significantly upregulated in the NPC tissues and the NPC cells (P<0.01). Notably, SMAD7 is a target gene of miR-663b and may be inhibited by miR-663b. Results indicated that NPC cell proliferation was significantly promoted by miR-663b mimics and significantly inhibited by miR-663b inhibitors (P<0.05 and P<0.01). In addition, the results indicated that, when compared with the negative control group the expression levels of E-cadherin were significantly decreased, whereas the expression levels of N-cadherin, Vimentin and matrix metalloproteinase-9 were significantly increased in the cells of the miR-663b mimics group (P<0.05 and P<0.01). However, cells in the miR-663b inhibitors group exhibited the opposite effects. In conclusion, the results of the present study indicated that miR-663b functions as a tumor promoter in NPC via promoting NPC cell proliferation and EMT by directly targeting SMAD7. [ABSTRACT FROM AUTHOR]

This paper studies the event-triggered consensus problem of leader-following linear multi-agent systems (MASs) under stochastic false data injection attacks (FDIAs), where the false data is injected into the communication channels between the network agents. The randomly occurring stealthy FDIAs on the communication channels are modeled by the Bernoulli process distributions. By designing a distributed event-triggered consensus control strategy, the consensus problem of the MAS with one-to-all FDIA scenario is studied firstly, then it is extended to the more flexible one-to-one FDIA scenario with a maximum number of destroyed neighboring channels for each agent. The event-triggered mechanism of the state-dependent threshold is proposed and the auxiliary variable is introduced to further prevent Zeno behavior. By utilizing stochastic analysis method, two bounded consensus theorems for directed MAS networks are presented for the above two cases of attack signals respectively to guarantee the followers synchronize to the leader within a limited margin of error ultimately. Finally, simulation results are provided to illustrate the validity and feasibility of the proposed event-triggered consensus control strategies. [ABSTRACT FROM AUTHOR]

Abstract: The intraseasonal variation of the Tibetan Plateau summer monsoon (TPSM) during 1979–2011 is investigated. The TPSM shows a dominant quasi‐biweekly oscillation (QBWO) in most summer seasons, and its active/break phases are closely related to more/less precipitation over the Tibetan Plateau. We suggest that the TPSM QBWO is associated with a southeastward propagating nonstationary wave train in the middle and upper troposphere. It shows equivalent barotropic vertical structures over the midlatitudes and a baroclinic structure over the eastern Tibetan Plateau. Wave activity flux analysis indicates that it originates from northern Europe, which is an active center of the summertime Arctic Oscillation (AO). The AO also shows significant QBWO signals and leads TPSM QBWO by about 13 days. Phase composite and wave activity flux analyses of AO QBWO confirmed that the wave train influences TPSM QBWO, suggesting that AO plays an important role in the TPSM on a 10‐ to 20‐day timescale. [ABSTRACT FROM AUTHOR]

A facile oxidative annulation of cyclohexanones and 2-aminophenyl ketones that uses molecular oxygen as the sole oxidant is described. The reaction provides a direct approach to acridines, a structural motif for a large number of fluorescent sensors, functional materials, ligands, and pharmaceuticals. In the presence of a palladium catalyst, high regioselectivity is observed when using non-symmetric 3-substituted cyclohexanones. With the use of oxygen as the terminal redox moderator, the electron gap of the global redox condensation process is filled and the reaction efficiency is significantly promoted. This protocol possesses many advantages such as using non-hazardous oxidant and readily available starting materials, high regioselectivity, and water as the only by-product. [ABSTRACT FROM AUTHOR]

A non-enzymatic glucose sensor, based on the silver nanoparticles (Ag-NPs)/poly ( o -phenylenediamine) (PoPD) composites, is developed by the electrochemical polymerization of o -phenylenediamine and electrodeposition of silver nanoparticles on an indium tin oxide electrode. The Ag-NPs/PoPD composites are characterized by atomic force microscopy, scanning electronic microscopy and energy dispersive spectrometer. Under the optimized experimental conditions, the proposed glucose sensor demonstrates a wide linear range from 0.15 to 13 mmol L − 1 with a correlation coefficient of 0.998. The proposed glucose sensor can be used to detect glucose in blood sample with a satisfactory result. In addition, the proposed sensor presents the advantages, such as facile preparation, low cost, high sensitivity and fast response time. It also exhibits good anti-interference performance and stability. [ABSTRACT FROM AUTHOR]

Geopolymer with Si/Al ratios from 2 to 4 were prepared by adding different contents of fused silica into geopolymer matrix. Effects of Si/Al ratios on the structure, mechanical properties and chemical stability in air of the obtained geopolymer were systematically investigated. The results showed that all the geopolymer samples were XRD amorphous. Geopolymer with Si/Al ratios of 2 and 2.5 showed similar structure and property and they were classed as KGP-I; and geopolymer with Si/Al ratios of 3, 3.5 and 4 were similar and they were class as KGP-II. In alkaline solution, reactivity of fused silica were higher than that of metakaolin, resulting in higher content of both residual metakaolin and free alkaline cation in KGP-II than in KGP-I. Fused silica partially reacted with the alkaline solution in KGP-II indicating chemical interfacial bonding between silica and binder phase. With the increase in Si/Al ratios, KGP-II especially for geopolymer with Si/Al of 4 showed much higher mechanical properties than KGP-I due to the increased Si-O-Si bonds and residual silica as reinforcement. However, KGP-II showed worse chemical stability in air than KGP-I, with the presence of efflorescence on the surface, which was attributed to their higher residual free K + . [ABSTRACT FROM AUTHOR]

A direct sulfination of nonactivated alcohols with arylsulfonylmethyl isocyanides under mild conditions [10 mol-% of Bi(OTf)3, 25 °C] was developed to afford sulfinates instead of the usually favored sulfones. The in situ multiple alcohol activation strategies, along with the properties of sulfones and sulfinate anions, were proposed to explain the reversed sulfinate/sulfone selectivity. [ABSTRACT FROM AUTHOR]

Study Question: Do N-acetylglucosaminyltransferase (GnT-V) and N-acetylglucosaminyltransferase III (GnT-III) play an important role in early spontaneous miscarriage (ESM) in humans. Summary Answer: The dynamic balance between GnT-V and GnT-III expression in chorionic villi differed between early normal pregnancy and ESM and was associated with altered β1,6-N-acetylglucosamine (β1,6-GlcNAc) and bisecting N-acetylglucosamine (bis-GlcNAc) branched N-glycans on integrin β1. What Is Known Already: GnT-V contributes to metastasis, while GnT-III is recognized as a metastasis suppressor. It has been reported that GnT-V contributes to placentation in the early phase of pregnancy, possibly regulating trophoblast invasion. However, the expressions of GnT-V and GnT-III in ESM have not been reported. Study Design, Size, Duration: Villous samples from 6 to 9 weeks of gestation were collected in the First Affiliated Hospital of Chongqing Medical University from May 2013 to September 2014 from 60 normal pregnant women undergoing elective termination of pregnancy and from 40 patients with a clinical diagnosis of ESM. Participants, Materials, Setting, Methods: Quantitative PCR and western blots were used to examine the GnT-V and GnT-III mRNA (Mgat5 and Mgat3) and protein expression, respectively, of chorionic villi in both the ESM group and the normal group from week 6 to week 9. We used immunofluorescence and immunohistochemistry to detect the location of GnT-V and GnT-III. Lectin fluorescence and histochemistry were used to test the location of β1,6-GlcNAc and bis-GlcNAc branching in the normal and ESM groups. To assess the functional capacity of GnT-V and GnT-III in the chorionic villi between the two groups, we used an enzyme-linked immunosorbent assay kit to measure the activity of these enzymes. Using co-precipitated integrin α5β1 followed by phytohaemagglutinin (PHA)-L and PHA-E blotting, we investigated whether GnT-V and GnT-III could modify the N-glycosylation profile in terms of the β1,6-GlcNAc and bis-GlcNAc structures in integrin α5β1 during the first trimester in both groups. Main Results and the Role Of Chance: In the normal group expression and activity of GnT-V and the concentration of its product, β1,6-GlcNAc were higher at week 9 than at weeks 6, 7 and 8 (P < 0.05). In contrast, the expression and activity of GnT-III and the concentration of its product, bis-GlcNAc were higher at week 6 than at weeks 7, 8 and 9 (P < 0.05). Compared with the normal group, the ESM group exhibited a lower expression of GnT-V and β1,6-GlcNAc (P < 0.05) and a higher expression of GnT-III and bis-GlcNAc (P < 0.05) with consistent changes in enzymatic activity. Immunofluorescence showed that GnT-V was located mainly in the cytoplasm of syncytiotrophoblasts (STBs) and chorionic villous cytotrophoblasts (CTBs), in both the ESM group and the normal group. β1,6-GlcNAc N-glycan was mainly located outside of the STB and CTB layer in normal villi and was expressed only rarely in the ESM villi. GnT-III was expressed primarily in the cytoplasm of STBs and expressed only very weakly in the CTBs of normal villi, whereas it was highly expressed in both the STBs and CTBs in the ESM group. bis-GlcNAc was primarily located outside of the STBs in the normal villi, whereas it was expressed much more abundantly outside of both the STBs and CTBs in the ESM group at each week of gestation. Moreover, decreased β1,6-GlcNAc-branched N-glycans and increased bis-GlcNAc-branched N-glycans on integrin β1 (P < 0.05) were observed in the ESM group. Wider Implications Of the Findings: Our findings provide a new insight for studying the mechanism of clinical ESM in humans and it might be valuable for the clinical diagnosis and treatment of ESM. Limitations, Reasons For Caution: The study lacks experiments in vitro to disclose the precise mechanism by which GnT-V and GnT-III regulate ESM. In some cases, degradation of the tissues after the miscarriage event cannot be ruled out. Study Funding/competing Interests: This study was supported by grants from the National Natural Science Foundation of China (31271546). The authors have no competing interests. [ABSTRACT FROM AUTHOR]

Intraseasonal variation (ISV) is especially prominent and unique in the Asian summer monsoon region. In this work, the dominant ISV mode over the Tibetan Plateau (TP) in the summer monsoon season (June-August), together with its structure and evolution, is identified using station observations, Global Precipitation Climatology Project precipitation data, and ERA-Interim during 1979-2011. Results indicate that quasi-biweekly oscillation (QBWO) is the dominant mode of ISV over the TP and is significant in terms of the circulation, precipitation, and diabatic heating fields. In particular, the QBWO is closely related to the onset and active/break phases of the TP summer monsoon. In most cases, the QBWO originates from the equatorial western Pacific and first propagates northwestward to the Bay of Bengal and northern India, then northward to the southeastern TP, and finally eastward to the East Asian area, showing a clockwise propagation pathway. Two main mechanisms are responsible for the northward propagation of the QBWO signals. The first, in operation when the QBWO signals are located to the south of 20°N, is the generation of barotropic vorticity induced by the easterly vertical shear, leading to the northward movement of the convection. The second mechanism, responsible for the propagation taking place farther north toward the TP, is a moisture advection effect that destabilizes the lower atmosphere ahead of the convection. Further analyses suggest that the QBWO plays a role in linking the ISV of the different subsystems of the Asian summer monsoon as a macroscale monsoon system. [ABSTRACT FROM AUTHOR]

In the past decades, it has been debated whether ecological niche should be conserved among closely related species (phylogenetic niche conservatism, PNC) or largely divergent (traditional ecological niche theory and ecological speciation) and whether niche specialist and generalist might remain in equilibrium or niche generalist could not appear. In this study, we employed morphological traits to describe ecological niche and test whether different niche dimensions exhibit disparate evolutionary patterns. We conducted our analysis on three Rhinogobio fish species ( R. typus, R. cylindricus, and R. ventralis) from the upper Yangtze River, China. Among the 32 measured morphological traits except body length, PCA extracted the first four principal components with their loading scores >1.000. To find the PNC among species, Mantel tests were conducted with the Euclidean distances calculated from the four principal components (representing different niche dimensions) against the pairwise distances calculated from mitochondrial cytochrome b sequence variations. The results showed that the second and the third niche dimension, both related to swimming ability and behavior, exhibited phylogenetic conservatism. Further comparison on niche breadth among these three species revealed that the fourth dimension of R. typus showed the greatest width, indicating that this dimension exhibited niche generalism. In conclusion, our results suggested that different niche dimensions could show different evolutionary dynamic patterns: they may exhibit PNC or not, and some dimensions may evolve generalism. [ABSTRACT FROM AUTHOR]

In horizontal position welding process, the key problem is the poor weld formation and weld defects induced by the downward motion of the molten metal. Base on the research results of welding process, droplet transfer, molten pool behavior, temperature field, reasons, and solutions of the typical weld appearance defects in rotating arc narrow gap horizontal GMAW are studied. The causes and mechanisms of the defects of sagging surface, under cut, and convex surface are explored. The relationship of the defects and the welding parameters is established. The main causes of the appearance defects can be classified into three categories. The first one is the excessive heat input of the welding process, the second one is unstable welding process, and the third one is the mismatch between the fusion area of base metal and filling metal. Finally, the optimum welding parameters of rotating arc narrow gap horizontal welding are determined. [ABSTRACT FROM AUTHOR]

The magnitude and spatial pattern of anomalous net biome exchange (NBE) induced by the 2015/16 El Niño over Amazonian rainforests remain uncertain. We here investigated them using multi‐model posterior NBE products in the Orbiting Carbon Observatory‐2 (OCO‐2) version 10 modeling intercomparison project. Results suggest that relative to the annual NBE average in 2017/18, larger anomalous carbon release occurred over the eastern and northern Amazonian rainforests in 2015/16, with a total flux of approximately 0.4 PgC yr−1 after assimilating satellite‐observed column CO2 concentrations (XCO2) over land. We further find that this anomalous spatial pattern was predominantly determined by soil dryness, while the total positive NBE anomaly was dominated by higher temperature with its contribution of approximately 68～70%. We believe that atmospheric inversions assimilating more satellite‐observed XCO2 in future can provide us more comprehensive understanding how Amazonian rainforests cope with the abiotic stresses induced by El Niño events. Plain Language Summary: Interannual variability of carbon flux associated with its drivers over Amazonian rainforests are not fully understood. We here used several groups' newly available posterior CO2 flux estimates to comprehensively investigate the net carbon flux anomaly induced by the 2015/16 extreme El Niño. A total net carbon flux anomaly of approximately 0.4 PgC yr−1 was estimated, which showed larger carbon release over the eastern and northern Amazonian rainforests. We further suggest that although dry conditions greatly shaped the spatial pattern of the anomalous carbon flux, the total carbon flux anomaly was controlled by the higher temperature, with its contribution of approximately 68∼70%. Key Points: Net biome exchange (NBE) anomalies over Amazonian rainforests induced by the 2015/16 El Niño were investigated based on multiple atmospheric inversionsThe spatial pattern of NBE anomaly was regulated by soil water with larger anomalies over the eastern and northern Amazonian rainforestsThe total NBE anomaly was estimated at about 0.4 PgC yr−1 in 2015/16 relative to the average in 2017/18, dominated by higher temperature [ABSTRACT FROM AUTHOR]

The spring sensible heating (SSH) over the Tibetan Plateau (TP), which can significantly affect the precipitation in China, has experienced three different stages of change, showing significant increasing (1961–1979, Stage I), decreasing (1980–2002, Stage II), and increasing (2003–2014, Stage III) trends. In this study, the impact of these different trends in TP SSH on spring precipitation (SPR) in China and their possible mechanisms are investigated, based on observations and the reanalysis product. In Stage I, the SPR represents a contrasting north-south pattern associated with the increasing TP SSH, showing increasing trends over southern China and decreasing trends over central and northern China. Further, the spatial distribution of SPR trends shows a contrasting east-west pattern in Stage II. That is, persistent weakening TP SSH plays a more crucial role in increasing and decreasing SPR over southwestern and southern China, respectively. However, compared with the significant trend in SPR in Stage III, the regulation of TP SSH on SPR weakens significantly. Dynamically, the increasing TP SSH in Stage I can strengthen the subtropical westerly jet in the upper layer, simultaneously configured with an anomalous cyclone in northeastern China, which deepens the East Asian trough. Thus, anomalous convergence in the upper layer occurs over central and northern China, favoring the downdraft. It then causes more cold and dry air to move southward in the lower troposphere, which then encounters the warm and wet southwest airflows, boosting the updraft over southern China. In Stage II, regression analysis shows that if the TP SSH increases, an anomalous cyclone in the middle and upper troposphere occurs over the western TP, causing the downdraft and less precipitation over southwestern China, while a cyclone in the lower troposphere occurs over the western North Pacific and extends to southern China, promoting the ascending motions and more precipitation in southern China. However, in this stage, TP SSH actually weakens, thus contributing to more precipitation over southwestern China and less precipitation over southern China. [ABSTRACT FROM AUTHOR]

Abstract: The hexagonal boron nitride (h-BN) grain shows typical lamellar structures, so textured materials can be achieved by arranging h-BN grains along the same direction. In this work, textured h-BN composite ceramics with the c-axis orientation arranged along pressure direction were manufactured by hot-press sintering using mullite as the sintering additive. The results show that sintering pressure is an important factor that affects not only the density and the textured degrees of composite ceramics, but also the mechanical properties. Based on the textured microstructure features, the composite ceramics show the obviously anisotropically characterized mechanical properties, such as elastic modulus, flexural strength and fracture toughness, together with various fracture mechanisms. [Copyright &y& Elsevier]

Highlights: [•] EIS was employed for the first time employed to determine fenvalerate. [•] Pre-treatment for the detection is simple in operation with this technique. [•] This method is label-free with high sensitivity and selectivity, rapidity and low cost. [ABSTRACT FROM AUTHOR]

Highlights: [•] PoPD was for the first time applied to form composite with metal oxide. [•] PoPD/MnO2 was synthesized by a one-step co-precipitation. [•] PoPD/MnO2 composite was for the first time applied as electrode materials in supercapacitor. [Copyright &y& Elsevier]

Highlights: [•] We first found that AST had better anti-lung fibrosis function than dexamethasone. [•] Anti-proliferation and pro-apoptosis effects might be by up-regulation of p53. [•] We establish astaxanthin as a potential drug candidate for lung fibrosis. [ABSTRACT FROM AUTHOR]

Abstract: For the first time, poly-o-phenylenediamine (PoPD) bulk material was electrochemically synthesized using an electrochemical method. Sodium dodecyl sulfate (SDS) was added to o-phenylenediamine (oPD) solution and PoPD with different morphologies were obtained. The as-prepared materials were applied as the electrode materials in supercapacitors. The specific capacitance (SC) of the resultant PoPD was determined to be 106.4Fg−1 in 1molL−1 KNO3 electrolyte from CV test. The electrochemical stability of PoPD electrode was investigated by charging and discharging the electrode for 1000 times in the potential range of −0.2 to 0.6V versus SCE at the current density of 500mAg−1. The electrode exhibits a good cycling stability, retaining up to 82% of its initial specific capacitance at 1000th cycle. This novel technique enables PoPD non-film material for supercapacitor application. [Copyright &y& Elsevier]

The impacts of the thermal forcing over the Tibetan Plateau (TP) in spring on changes in summer rainfall in China are investigated using historical records from the period between 1980 and 2008. The spring sensible heat (SH) flux and snow depth over the TP both decreased over this time period, although the trend in SH was more significant than that in snow depth. The similarity between patterns of precipitation trends over China and corresponding patterns of regression coefficients on the leading mode of spring SH change over the TP demonstrates the distinct contribution of changes in TP SH during spring. Enhanced precipitation in southern China was accompanied by increases in heavy rainfall, precipitation intensity, and the frequency of precipitation events, while reduced precipitation in northern China and northeastern China was primarily associated with decreases in the frequency of precipitation events. Further analysis using observational data and numerical simulations reveals that the reductions in SH over the TP have weakened the monsoon circulation and postponed the seasonal reversal of the land-sea thermal contrast in East Asia. In addition, the positive spring SH anomaly may generate a stronger summer atmospheric heat source over the TP due to the positive feedback between diabatic heating and local circulation. [ABSTRACT FROM AUTHOR]

Abstract: Electrochemical impedance immunosensor, with its high sensitivity from electrochemical impedance analysis and ideal specificity from the immunoassay, is increasingly used in the detection of a kind of phenoxy acid herbicides which is 2,4-Dichlorophenoxybutyric acid (2,4-DB). In this experiment, synthetic 2,4-DB antibodies were immobilized on the electrode by the crosslinking of l-Cysteine/glutaraldehyde, and 2,4-DB were measured by the increase of electron-transfer resistance when the immune reaction occurred, with Fe(CN)6 3−/Fe(CN)6 4− as the probe. Under optimal conditions, the change of resistance is in a linear relationship with the logarithm of the concentration in the range of 1.0×10−7–1.0×10−3 g/L (R=0.994) with the detection limit of 1.0×10−7 g/L (0.1ppb). This method bears such merits as simplicity in operation, high sensitivity, wide linear range, specificity, reproducibility and good stability. The actual soybean samples were analyzed with the recovery of 82.8%–102.3%. [Copyright &y& Elsevier]

Astaxanthin (AST), a xanthophylls carotenoid, possesses significant anticancer effects. However, to date, the molecular mechanism of anticancer remains unclear. In the present research, we studied the anticancer mechanism of AST, including the changes in cell ultrastructure, such as the mitochondrion, rough endoplasmic reticulum (RER), Golgi complex, and cytoskeleton, the inhibition of Janus kinase 1(JAK1)/transduction and the activators of the transcription-3 (STAT3) signaling pathway using rat hepatocellular carcinoma CBRH-7919 cells. Cell apoptosis was evaluated and the expressions of JAK1, STAT3, non-metastasis23-1 (nm23-1), and apoptotic gene like B-cell lymphoma/leukemia-2 (bcl-2), B-cell lymphoma-extra large (bcl-xl), proto-oncogene proteins c myc (c-myc) and bcl-2- associated X (bax) were also examined. The results showed that AST could induce cancer cell apoptosis. Under transmission electron microscope, the ultrastructure of treated cells were not clearly distinguishable, the membranes of the mitochondrion, RER, Golgi complex were broken or loosened, and the endoplasmic reticulum (ER) was degranulated. Cytoskeleton depolymerization of the microtubule system led to the collapse of extended vimentin intermediate filament bundles into short agglomerations with disordered distributions. AST inhibited the expression of STAT3, its upstream activator JAK1, and the STAT3 target antiapoptotic genes bcl-2, bcl-xl, and c-myc. Conversely, AST enhanced the expressions of nm23-1 and bax. Overall, our findings demonstrate that AST could induce the apoptosis of CBRH-7919 cells, which are involved in cell ultrastructure and the JAK1/STAT3 signaling pathway. [ABSTRACT FROM AUTHOR]

The trend in the atmospheric heat source over the central and eastern Tibetan Plateau (CE-TP) is quantitatively estimated using historical observations at 71 meteorological stations, three reanalysis datasets from 1980-2008, and two satellite radiation datasets from 1984-2007. Results show that a weakening of sensible heat (SH) flux over the CE-TP continues. The most significant trend occurs in spring, induced mainly by decelerated surface wind speeds. The ground-air temperature difference shows a notable increasing trend over the last 5 years. Trends in net radiation flux of the atmospheric column over the CE-TP, evaluated by two satellite radiation datasets, are clearly different. Trends in the atmospheric heat source calculated by the three reanalysis datasets are not completely consistent, and even show opposite signals. Results from the two datasets both show a weakening of the heat source but the magnitude of one is significantly stronger, whereas an increase is indicated by the other data. Therefore, it is challenging to accurately calculate the trend in the atmospheric heat source over the CE-TP, particularly from the estimates of the reanalysis datasets. [ABSTRACT FROM AUTHOR]

The following basins in the northern area of China are selected as the case study areas: the Yellow River, the Haihe River, the Liaohe River, and the Songhuajiang River. Qualitative and quantitative analyses of the impact of human activity on river runoff in different spatio-temporal scales, including daily, monthly, annual, inter-decade, inter-century variations, according to long-term observation data, are carried out. The driving forces of annual runoff change in those rivers are also analyzed. It can be seen from observed data that the quantity of downstream flow in the northern part of China depends on precipitation over a catchment and withdrawal from the upstream. River runoff has a tendency towards decrease in terms of a natural basin as well as in terms of an administrative region. Besides the climatic changes, the increase in the amount of water taken from river course is the direct cause why observed runoff decreases in the northern part of China. The frequency, at which minor daily discharge appears, increases rapidly. Annual mean runoff generated from the same order of precipitation in 1980s and 1990s decreases by 20–50% as compared in 1950s and 1960s. The impact of human activity on river discharge is more in arid or semi-arid areas than in humid areas. [Copyright &y& Elsevier]

The metal transfer process of underwater flux-cored wire wet welding is successfully observed by an X-ray transmission method. The relatively large retention forces acting on the droplet induced by the electromagnetic force, vaporization force, surface tension resultant force and gas flow drag force make the transfer mode as a combination of globular repelled transfer mode and short circuit transfer mode with the average transfer frequency of 4.3 Hz with arc voltage of 24 V and welding current of 240 A. [ABSTRACT FROM AUTHOR]

Lassa virus (LASV) is a rodent-borne arenavirus circulating in West African regions that causes Lassa fever (LF). LF is normally asymptomatic at the initial infection stage, but can progress to severe disease with multiorgan collapse and hemorrhagic fever. To date, the therapeutic choices are limited, and there is no approved vaccine for avoiding LASV infection. Adenoviral vector-based vaccines represent an effective countermeasure against LASV because of their safety and adequate immunogenicity, as demonstrated in use against other emerging viral infections. Here, we constructed and characterized a novel Ad5 (E1-, E3-) vectored vaccine containing the glycoprotein precursor (GPC) of LASV. Ad5-GPCLASV elicited both humoral and cellular immune responses in BALB/c mice. Moreover, a bioluminescent imaging-based BALB/c mouse model infected with GPC-bearing and luciferase-expressing replication-incompetent LASV pseudovirus was utilized to evaluate the vaccine efficacy. The bioluminescence intensity of immunized mice was significantly lower than that of control mice after being inoculated with LASV pseudovirus. This study suggests that Ad5-GPCLASV represents a potential vaccine candidate against LF. [ABSTRACT FROM AUTHOR]

In order to improve the selectivity of porous membrane for vanadium redox flow battery (VRB). A polypyrrole (PPy) thin film composite (TFC) membrane was prepared via interfacial polymerization (IP) method and investigated for VRB application. The optimized PPy TFC membrane has shown both low VO2+ permeability and low area resistance compared to that of commercial Nafion 115 membrane. The VRB cell assembled with PPy TFC membrane shows a coulombic efficiency (CE) of 98.1% and energy efficiency of 81.0% at 80 mA cm−2, which is 2.0% and 6.3% higher than that of Nafion 115 membrane, respectively. Furthermore, 93 cycles charge-discharge test proves that the PPy TFC membrane is very stable and the CE decrease rate is only 0.4% for per-cycle on average. Considering the high selectivity, facile preparation procedure and high stability of PPy TFC membrane, it is thus an ideal system for VRB application to overcome the trade-off between vanadium ions permeability and proton conductivity. Unlabelled Image • Polypyrrole thin film composite membrane was investigated for VRB application for the first time. • The thin film composite membrane was prepared via interfacial polymerization method. • The membrane showed a superior VRB performance to that of Nafion 115 membrane. [ABSTRACT FROM AUTHOR]

The Tibetan Plateau (TP) vortex (TPV), one of the crucial weather systems triggering rainfall, plays a key role in modulating precipitation over TP and downstream regions. The role of atmospheric heat source in TPV development is explored by a case study in June 2016, using high-resolution ERA5 reanalysis, black-body temperature (TBB) obtained from the Fengyun-2E (FY-2E) satellite, and precipitation amount from the Tropical Rainfall Measurement Mission (TRMM). The evolutions of TPV can be split into three stages, i.e., generation, development, and pre-moving-off stage. The intensity of TPV increases with fluctuations, with weaker and shallower TPV in the generation stage, strongest in the development stage and deepest in the pre-moving-off stage. Importantly, the genesis of TPV is related to the surface warming center driven by surface sensible heating while its development is primarily dependent on the latent heat of condensation. The main contributor of the latent heat of condensation is further analyzed as a vertical transport of the water vapor that promotes TPV development. [ABSTRACT FROM AUTHOR]

Background: Most schizophrenia patients are supported by main informal caregivers at home in China. This study aims to investigate the further needs of social supports for main informal caregivers of schizophrenia patients and to analyze influencing factors on the awareness and utilization of social supports in Beijing. The results of this study could potentially act as reference for health professionals to implement appropriate and effective support programs. Methods: A mixed-methods approach was used in this study. Awareness, utilization and influencing factors of social supports for main informal caregivers were investigated using questionnaires in 6 urban districts in Beijing. Meanwhile, individual in-depth interviews with 10 main informal caregivers from the urban districts of Beijing were conducted to identify the caregivers' perspective on social supports and their further needs. Results: Quantitative results showed that although the government provided multi-channel resources for schizophrenia patients and their families, awareness and utilization of the resources such as rehabilitation and relevant subsidies were less than 10.0 and 5.0% respectively. Most caregivers in in-depth interviews expressed that they had negative experiences with respect to obtaining social supports, and they emphasized that more support would be needed in terms of financial support, respect, and rehabilitation institutions. Conclusions: The awareness and utilization of social supports are low for main informal caregivers of schizophrenia patients. More services and improved public attitudes are needed for schizophrenia patients and their caregivers. [ABSTRACT FROM AUTHOR]

Interferon (IFN) is a broad-spectrum antiviral agent that activates cell surface receptors and causes cells to produce antiviral proteins, inhibiting viral replication. Interferon use has long been associated with diabetes. The PubMed database was searched for articles related to diabetes and interferon from March 30, 2020. Patients were divided into type 1 diabetes group and type 2 diabetes group. We reviewed the relevant literature to compare interferon-associated T1D and interferon-associated T2D differences. Interferon treatment shortened the incubation period of T2D and changed the original T2D to T1D. The onset of interferon-associated T1D required longer periods of IFN treatment than interferon-associated T2D, and the interferon-associated T1D group had higher GADA positive rates, lower BMI, lower fasting blood glucose, and greater insulin dependence (p<0.05). More patients in the T1D group were positive for HLA-DRB1*04, DRB1*03, DRB1*09, DRB1*14, HLA-DQB1*04, HLA-DQB1*02, HLA-DQB1*03, and HLA-DQB1*05. The combined detection of GAD antibodies and HLA alleles may be an effective method to predict the incidence of T1D after IFN treatment. [ABSTRACT FROM AUTHOR]

We investigated the intraseasonal relationship between the atmospheric heat source over Tibetan Plateau (TP) and summer rainfall in eastern China. A quasi-biweekly oscillation (QBWO) is the common dominant periodicity over both the TP and eastern China. Crucially, the TP heat source QBWO leads rainfall QBWO over its downstream region by 2–8 days. The QBWO over the TP shows a significant eastward propagation. Phase composite further identified the specific propagation pathway: TP QBWO first propagates eastward to central China, southward to southern China, and then northeastward to the lower reaches of the Yangtze River with a zigzag propagating pathway. Mechanistically, the eastward propagation of the upper level divergence caused by the movement of the 200 hPa jet core and south Asian high contributes to the eastward propagation of the rainfall QBWO. Simultaneously, the eastward (westward) shift in the western north Pacific subtropical high causes deepening (flattening) of the monsoon trough and the occurrence of an anomalous cyclone (anticyclone) over the western north Pacific. An anomalous anticyclonic (cyclonic) circulation around the TP appears with the wet-to-dry (dry-to-wet) phase transition of the TP QBWO. Together, they play a crucial part in the southward (northeastward) movement of the QBWO. Further dynamic analysis indicates that the horizontal moisture advection acts on the whole eastward-propagating process of the QBWO, whereas the horizontal vorticity advection is only significant when QBWO is over the TP. This study shows that the fluctuations in TP heat source are important indicators in extended forecasts of summer rainfall in eastern China. [ABSTRACT FROM AUTHOR]

Background: Informal caregivers of people with dementia in Beijing are increasingly called upon to provide home-based care for their patients due to the increasing number of dementia patients and the shortage of standardized institutional solutions of care for patients in China. This study aimed to clarify the needs of informal caregivers and barriers of primary care workers toward dementia management in primary care in Beijing to provide references that may help to improve the care and services provided to individuals with dementia and their family caregivers residing in urban China. Methods: A mixed-methods approach was used in this study. We performed individual in-depth interviews with 10 informal caregivers. Moreover, we carried out focus group interviews with 29 primary care workers. Content analysis was used to separately identify themes and codes. Discrepancies were discussed until final agreement was achieved. Results: Three themes representing the core attitudes of informal caregivers and primary care workers were identified: care knowledge and skills, psychological counseling, and collaborative management. Most primary care workers believed that the management of dementia patients in primary care was necessary. However, due to the heavy work load and different medical specialties involved, these workers were unable to manage it. Conclusions: Professional training focused on dementia for primary care workers should be strengthened. At the same time, the establishment of a community-based dementia team management model that includes specialists, community health service centers (CHSCs), and community committees should be explored. [ABSTRACT FROM AUTHOR]

Background: Migrants are the unique production of China's urbanization process. They are often excluded from social welfare and security systems of cities, and often exposed to high health risk related closely to their health problems. This research sought to unveil and explore the influencing factors on health services utilization of migrants in Beijing.Methods: A sample of 2014 inter-provincial migrants and 4578 residents with Beijing "Hukou" who were 15 years old and above was chosen by three-stage stratified cluster sampling method. A structured questionnaire survey was conducted via face-to-face interviews. Anderson health service utilization model was used to demonstrate the effects of the explanatory variables on health seeking behavior from predisposing, enabling and need variables.Results: The study reveals that the rate of 'having symptoms' of migrants was lower than that of residents with "Hukou" only in the group of 25 to 34 years old in the past month. 503 migrants (25.0%) and 1441 (31.5%) residents with "Hukou" reported at least one episode of discomfort in the past month, and the rate of health service seeking behavior among migrants (46.8%) was lower than residents with "Hukou" (62.6%) (P < 0.0001). Chi-square independence test shows that age, ethnicity, employment status, having chronic disease and the degree of symptom were the major determinants affecting migrants to receive health services. The binary logistic regression indicates that the degree of symptom as the need variable and ethnicity as the predisposing variable were the strong and consistent determinants of health services seeking behavior. The migrants with moderate degree and severe degree of symptom in the past month were at 1.623-times (OR = 1.623) and 5.035-times (OR = 5.035) higher chances of seeking health services respectively, comparing to mild degree of symptom. Minority migrants were less likely to seek health services than Han migrants (OR = 0.282).Conclusions: The results indicate that the current health delivery system is not conducive for migrants to seek appropriate health services. Relevant policies and feasible measures, including increasing the coverage of health insurance and improving the health perception of migrants should be vigorously implemented to provide affordable health services and change health service utilization behaviors for migrants. [ABSTRACT FROM AUTHOR]

An abstract of the article "Efficient Synthesis of Isoquinolines by AgNO3-Catalyzed Sequential Imination-Annulation of 2-Alkynyl Aldehydes with Ammonium Bicarbonate" by Y. Zhao and colleagues is presented.

Abstract Based on conventional ion exchange method from zeolite materials, we herein report a facile synthetic procedure to prepare monoclinic celsian ceramics through thermal treatment of ion-exchanged 3D printing geopolymer precursors. In this contribution, both ion exchange process and thermal evolution of celsian precursors were systematically investigated. The results proved 3D printing Na- and K- based geopolymer were ideal precursors with low residual Na+ content (0.10 meq/g) and K+ content (0.05 meq/g) and translated into monoclinic celsian after being heated at 1400 °C. With increasing Sr2+ doping concentration from 20% (mole ratio) to 30% (mole ratio), more significant phase transition results (hexagonal → monoclinic) were observed. All 3D printing geopolymer precursors kept fine integrity and stable 3D structure upon ion exchange process and heating, indicating the combination of geopolymer technique and 3D printing opens up a versatile and robust way to yield monoclinic celsian ceramics and related components of complex shapes. [ABSTRACT FROM AUTHOR]

The inhibition performance of three pyrido[1,2-a]benzimidazoles, namely, benzo[4,5]imidazo[1,2-a]pyridine (BIP), 2-methylbenzo[4,5]imidazo[1,2-a]pyridine (MBIP), and 2-(trifluoromethyl)benzo[4,5]imidazo[1,2-a]pyridine (TBIP), for steel corrosion in hydrochloric acid solution were researched through a weight loss test, electrochemical techniques, surface morphology (SEM, XPS) studies, and theoretical methods. The experimental results revealed that TBIP, BIP, and MBIP had excellent inhibition performance, and their maximum inhibition efficiencies at 0.25 mmol L−1 were 95.48%, 97.65%, and 98.96%, respectively. The properties of these inhibitors are considered to be mixed-type, and their adsorption mode belongs to the Langmuir isothermal type. The formation and properties of an adsorbed film on a steel surface were investigated using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Quantum chemical calculations provided insightful quantitative information to conclude the correlation between the molecular structures and inhibition performance. Molecular dynamics (MD) simulations were carried out to explore the configurationally adsorption behavior of these pyrido[1,2-a]benzimidazoles on Fe(110) surface, and the binding energy of these three inhibitors followed the order MBIP ＞ BIP ＞ TBIP, which is consistent with the experimental evaluation results. [ABSTRACT FROM AUTHOR]

By using the observational and reanalysis datasets during the period of 1979–2018, the role of the thermal effect of the Tibetan Plateau (TP) and Artic Oscillation (AO) in the midsummer (July–August) extreme high-temperature events (EHEs) over the Yangtze River Valley (YRV) is investigated. The primary mode of the EHEs (EHEs_EOF1) over the YRV is characterized by an increased frequency of the EHEs over the YRV, with two centers located in the upper and lower reaches of the YRV, respectively. The results indicate that the higher YRV EHEs frequency is associated with anticyclonic anomalies over northern China, which leads to the descending motion over the YRV, further resulting in the reduced middle to low clouds and enhanced solar radiation. In addition, warmer surface ground will heat the atmosphere through the sensible heat and upward longwave radiation. Moreover, less soil moisture also favors the occurrence of the EHEs. Further analysis demonstrates that the EHEs_EOF1 is related to the midsummer surface air temperature over the TP (TP-SAT) and the AO. The anticyclonic anomalies over northern China are considered to be the key factors favoring the YRV EHEs, which is associated with the TP-SAT and AO, of which TP-SAT dominates. TP warming can induce anticyclonic anomalies over northern China, thus favoring the YRV EHEs. AO can also affect the anticyclonic anomalies over northern China through the Rossby wave train originating from the northwestern Atlantic, which is largely modulated by the TP thermal forcing. In addition, the model experiment with the linear baroclinic model (LBM) further provides direct evidence to illustrate the impact of the thermal condition of the TP on generating circulation anomalies that conducive to the EHEs over the YRV. • Anomalous anticyclone (AC) over northern China favors the extreme high-temperature events over the Yangtze River Valley. • AC over northern China is mainly driven by the thermal effect of the Tibetan Plateau. • Arctic Oscillation can also affect the AC through the Rossby wave train originating from the northwestern Atlantic. [ABSTRACT FROM AUTHOR]

In this paper, a honeycomb Si3N4 ceramic was fabricated by 3D printing with a well‐preserved structure. The effects of Si3N4 content on the rheological properties of Si3N4/sol–silica ink and the printing resolution of products were investigated. The microstructure, phase composition, liner shrinkage rate, and fracture behavior of printed samples before and after sintering were systematically characterized in detail. The results showed that the modified inks had the optimized rheological properties, and the stress–shear rate curves corresponding to each slurry could be well described by Bingham and Herschel–Bulkley fluid models. The corresponding slump rates of the printed samples with different Si3N4 to sol–silica mass ratios were all lower than 4%, and the linear shrinkage rate of all of the samples after sintering was below 20%. The fracture behavior under compressive loading of the honeycomb Si3N4 ceramics tended to be non‐catastrophic fractures both before and after sintering. The compressive strengths of all of the printed samples decreased with the increase of the Si3N4 content, and the highest compressive strength of the honeycomb ceramics could reach 131.2 MPa after sintering at 1600°C, which was about 366.9% higher than that of the samples in green state prior to the sintering. [ABSTRACT FROM AUTHOR]

Summary: WRKY transcription factors are known to participate in the defence responses of higher plants. However, little is known about the roles of such proteins, especially regarding their functions in the resistance of oilseed rape (Brassica napus) to Sclerotinia sclerotiorum, a necrotrophic fungal pathogen that causes stem rot. In this study, we identified BnWRKY33 as a S. sclerotiorum‐responsive gene that positively regulates resistance to this pathogen by enhancing the expression of genes involved in camalexin synthesis and genes regulated by salicylic acid (SA) and jasmonic acid (JA). We also identified a S. sclerotiorum‐responsive region in the promoter of BnWRKY33, which we revealed to be a relatively conserved W‐box region in the promoters of homologous genes in different species. Using this S. sclerotiorum‐responsive region as bait in a yeast one‐hybrid assay, we identified another WRKY transcription factor, BnWRKY15, and observed that both BnWRKY15 and BnWRKY33 could bind to this region. In addition, BnWRKY15 overexpression simultaneously increased the susceptibility of B. napus to S. sclerotiorum and down‐regulated BnWRKY33 after different durations of infection. Furthermore, BnWRKY15, which contains a transcriptional repression domain, exhibited reduced transactivation ability and could reduce the transactivation ability of BnWRKY33 in Arabidopsis protoplast assays. Therefore, we suggest that the increased susceptibility of BnWRKY15‐overexpressing plants results from reduced BnWRKY33 expression, which is due to the inhibition of BnWRKY33 transcriptional activation by BnWRKY15. [ABSTRACT FROM AUTHOR]

A concise synthetic approach to the marine natural product (+)-aureol has been achieved from readily available starting materials using obviously fewer steps in comparison to the related report in literature (6 steps versus 12 steps from (+)-sclareolide). Key steps of this protocol include a boron trifluoride-catalyzed domino 1,2-H and 1,2-methyl shifts and a nickel(II)-catalyzed cross-coupling reaction between an alkyl iodide and an aryl Grignard reagent. [ABSTRACT FROM AUTHOR]

Large interannual atmospheric CO2 variability is dominated by the response of the terrestrial biosphere to El Niño-Southern Oscillation (ENSO). However, the behavior of terrestrial ecosystems differs during different El Niños in terms of patterns and biological processes. Here, we comprehensively compare two extreme El Niños (2015/16 and 1997/98) in the context of a multi-event "composite" El Niño. We find large differences in the terrestrial carbon cycle responses, even though the two events were of similar magnitude. More specifically, we find that the global-scale land-atmosphere carbon flux (FTA) anomaly during the 1997/98 El Niño was 1.64 PgCyr-1, but half that quantity during the 2015/16 El Niño (at 0.73 PgCyr-1). Moreover, FTA showed no obvious lagged response during the 2015/16 El Niño, in contrast to that during 1997/98. Separating the global flux by geographical regions, we find that the fluxes in the tropics and extratropical Northern Hemisphere were 1.70 and -0.05 PgCyr-1 during 1997/98, respectively. During 2015/16, they were 1.12 and -0.52 PgCyr-1, respectively. Analysis of the mechanism shows that, in the tropics, the widespread drier and warmer conditions caused a decrease in gross primary productivity (GPP; -0.73 PgCyr-1) and an increase in terrestrial ecosystem respiration (TER; 0.62 PgCyr-1) during the 1997/98 El Niño. In contrast, anomalously wet conditions occurred in the Sahel and East Africa during 2015/16, which caused an increase in GPP, compensating for its reduction in other tropical regions. As a result, the total 2015/16 tropical GPP and TER anomalies were -0.03 and 0.95 PgCyr-1. GPP dominance during 1997/98 and TER dominance during 2015/16 accounted for the phase difference in their FTA. In the extratropical Northern Hemisphere, the large difference occurred because temperatures over Eurasia were warmer during the 2015/16, as compared with the cooling seen during the 1997/98 and the composite El Niño. These warmer conditions enhanced GPP and TER over Eurasia during the 2015/16 El Niño, while these fluxes were suppressed during 1997/98. The total extratropical Northern Hemisphere GPP and TER anomalies were 0.63 and 0.55 PgCyr-1 during 1997/98, and 1.90 and 1.45 PgCyr-1 during 2015/16, respectively. Additionally, wildfires played a less important role during the 2015/16 than during the 1997/98 El Niño. [ABSTRACT FROM AUTHOR]