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Background Selenium (Se) deficiency causes a series of health disorders in humans, and Se concentrations in the edible parts of crops can be improved by altering exogenous Se species. However, the uptake, transport, subcellular distribution and metabolism of selenite, selenate and SeMet (selenomethionine) under the influence of phosphorus (P) has not been well characterized. Results The results showed that increasing the P application rate enhanced photosynthesis and then increased the dry matter weight of shoots with selenite and SeMet treatment, and an appropriate amount of P combined with selenite treatment increased the dry matter weight of roots by enhancing root growth. With selenite treatment, increasing the P application rate significantly decreased the concentration and accumulation of Se in roots and shoots. P1 decreased the Se migration coefficient, which could be attributed to the inhibited distribution of Se in the root cell wall, but increased distribution of Se in the root soluble fraction, as well as the promoted proportion of SeMet and MeSeCys (Se-methyl-selenocysteine) in roots. With selenate treatment, P0.1 and P1 significantly increased the Se concentration and distribution in shoots and the Se migration coefficient, which could be attributed to the enhanced proportion of Se (IV) in roots but decreased proportion of SeMet in roots. With SeMet treatment, increasing the P application rate significantly decreased the Se concentration in shoots and roots but increased the proportion of SeCys2 (selenocystine) in roots. Conclusion Compared with selenate or SeMet treatment, treatment with an appropriate amount of P combined with selenite could promote plant growth, reduce Se uptake, alter Se subcellular distribution and speciation, and affect Se bioavailability in wheat.

Background Currently, the study outcomes of anthropometric markers to predict the risk of hypertension are still inconsistent due to the effect of racial disparities. This study aims to investigate the most effective predictors for screening and prediction of hypertension (HTN) in the Chinese middle-aged and more elderly adult population and to predict hypertension using obesity and lipid-related markers in Chinese middle-aged and older people. Methods The data for the cohort study came from the China Health and Retirement Longitudinal Study (CHARLS), including 4423 middle-aged and elderly people aged 45 years or above. We examined 13 obesity- and lipid-related indices, including waist circumference (WC), body mass index (BMI), waist-height ratio (WHtR), visceral adiposity index (VAI), a body shape index (ABSI), body roundness index (BRI), lipid accumulation product index (LAP), conicity index (CI), Chinese visceral adiposity index (CVAI), triglyceride-glucose index (TyG-index) and their combined indices (TyG-BMI, TyG-WC, TyG-WHtR). To compare the capacity of each measure to forecast the probability of developing HTN, the receiver operating characteristic curve (ROC) was used to determine the usefulness of anthropometric indices for screening for HTN in the elderly and determining their cut-off value, sensitivity, specificity, and area under the curve (AUC). Association analysis of 13 obesity-related anthropometric indicators with HTN was performed using binary logistic regression analysis. Results During the four years, the incident rates of HTN in middle-aged and elderly men and women in China were 22.08% and 17.82%, respectively. All the above 13 indicators show a modest predictive power (AUC > 0.5), which is significant for predicting HTN in adults (middle-aged and elderly people) in China (P Conclusions The 13 obesity- and lipid-related indices in this study have modest significance for predicting HTN in Chinese middle-aged and elderly patients. WHtR and Tyg-WHtR are the most cost-effective indicators with moderate predictive value of the development of HTN.

Background Butorphanol slightly influences the respiratory and circulatory systems, has a better effect on relieving the discomfort caused by mechanical traction, and has a low incidence of postoperative nausea and vomiting (PONV). Combined butorphanol and propofol may suppress postoperative visceral pain, which is avoidable in gastrointestinal endoscopy. Thus, we hypothesized that butorphanol could decrease the incidence of postoperative visceral pain in patients undergoing gastroscopy and colonoscopy. Methods This was a randomized, placebo-controlled, and double-blinded trial. Patients undergoing gastrointestinal endoscopy were randomized to intravenously receive either butorphanol (Group I) or normal saline (Group II). The primary outcome was visceral pain after the procedure 10 min after recovery. The secondary outcomes included the rate of safety outcomes and adverse events. Postoperative visceral pain was defined as a visual analog scale (VAS) score ≥ 1. Results A total of 206 patients were enrolled in the trial. Ultimately, 203 patients were randomly assigned to Group I (n = 102) or Group II (n = 101). In total, 194 patients were included in the analysis: 95 in Group I and 99 in Group II. The incidence of visceral pain at 10 min after recovery was found to be statistically lower with butorphanol than with the placebo (31.5% vs. 68.5%, respectively; RR: 2.738, 95% CI [1.409–5.319], P = 0.002), and the notable difference was in pain level or distribution of visceral pain (P = 0.006). Conclusions The trial indicated that adding butorphanol to propofol results in a lower incidence of visceral pain after surgery without noticeable fluctuations in circulatory and respiratory functions for gastrointestinal endoscopy patients. Trial registration Clinicaltrials.gov NCT04477733 (PI: Ruquan Han; date of registration: 20/07/2020).

Background In a rapidly changing healthcare environment, Self-directed learning (SDL) ability is recognized as a crucial condition for nursing students and nurse to deal with severe challenges positively. Developing SDL ability is becoming more and more important among nursing students. SDL is related to nursing students enhancing their own knowledge, skills and maintaining lifelong learning. This study is aim at translating the Self-directed Learning Instrument (SDLI) into Chinese and verify its reliability and validity among nursing students. Methods The study adopted a cross-sectional design and the multistage sampling design. The SDLI was translated into Chinese, and the reliability and validity of the scale were tested among 975 nursing students. Results The Cronbach’s α value of the Chinese version of SDLI was 0.916. The split-half reliability coefficient was 0.829, and the retest coefficient was 0.884. The content validity index of the scale was 0.95. Furthermore, the four-factors model was obtained by using exploratory factor analysis, explaining 55.418% variance, and the communalities of the items ranged from 0.401 to 0.664. With modified confirmatory factor analysis, the fit indices were chi-square/degree of freedom (CMIN/DF) = 2.285, the comparative fit index (CFI) = 0.947, and the tucker lewis index (TLI) was 0.938. And, the model fitting indexes were all in the acceptable range and confirmatory factor analysis indicated that the model fit the SDLI well. Conclusion The Chinese version of SDLI has good validity and reliability among nursing students. It can be used to measure the SDL ability of nursing students in China.

Background Satisfactory brain relaxation is essential in neurosurgery. Desflurane anesthesia and propofol-based total intravenous anesthesia (TIVA) have different effects on cerebral hemodynamics, potentially contributing to discrepant brain relaxation. The purpose of this study was to compare the effects of desflurane and TIVA on brain relaxation in patients undergoing craniotomy for supratentorial tumors. Methods In this randomized, controlled study, we enrolled patients aged 18–60 years, with ASA I–III, who were scheduled to undergo elective craniotomy for supratentorial tumors. Patients were randomly assigned in a 1:1 ratio to receive desflurane anesthesia or TIVA. The primary outcome was the proportion of satisfactory brain relaxation. Secondary outcomes included emergence and extubation times, recovery of cognitive function and postoperative complications. Results Of 369 patients who were assessed for eligibility, 111 were randomized and 110 were included in the modified intention-to-treat analysis (55 in the desflurane group and 55 in the TIVA group). The proportion of satisfactory brain relaxation was similar between the two groups: 69% in the desflurane group and 73% in the TIVA group (RR: 0.950, 95% CI: 0.748–1.207; P = 0.675). Patients assigned to the desflurane group had shorter emergence (10 [8–13] min vs. 13 [10–20] min, P P P = 0.003), but experienced increased postoperative nausea and vomiting (PONV) (16 [29%] vs. 6 [11%] P = 0.017) and tachycardia (22 [40%] vs. 9 [16%], P = 0.006) during recovery. Conclusions Desflurane anesthesia and TIVA provide similar brain relaxation in patients without intracranial hypertension undergoing elective craniotomy. Desflurane accelerates the recovery from anesthesia but is associated with increased PONV and tachycardia during the recovery period. Trial registration Clinicaltrial.gov (NCT04691128). Date of registration: December 31, 2020.

Introduction Stellate ganglion block has been reported to expand cerebral vessels and alleviate vasospasm after aneurysmal subarachnoid hemorrhage. However, the causal relationship between early stellate ganglion block and cerebral vasospasm prevention has not yet been established. The purpose of this study was to explore the effectiveness and safety of early stellate ganglion block as a preventive treatment for cerebral vasospasm and delayed cerebral ischemia. Methods/design This is a single-center, prospective, randomized, controlled, blinded endpoint assessment superiority trial. A total of 228 patients will be randomized within 48 h of aneurysmal subarachnoid hemorrhage onset in a 1:1 ratio into two groups, one group receiving an additional e-SGB and the other group receiving only a camouflaging action before anesthesia induction in the operating room. The primary outcome is the incidence of symptomatic vasospasm within 14 days after aSAH. Further safety and efficacy parameters include the incidence of radiographic vasospasm, new cerebral infarction, postoperative delirium, and complications up to 90 days after surgery; postoperative cerebral hemodynamics; Mini-Mental State Examination score; modified Rankin scale score; and all-cause mortality up to 90 days after surgery. Discussion This is a randomized controlled trial to explore the effectiveness and safety of early stellate ganglion block as a preventive treatment to reduce cerebral vasospasm in patients with aneurysmal subarachnoid hemorrhage. If the results are positive, it may provide a new direction for the prevention and treatment of cerebral vasospasm and delayed cerebral ischemia. Trial registration The study was registered on Clincaltrials.gov on December 13, 2020 (NCT04691271).

Investigation of the dynamic characteristics of linear guideway is essential for enhancing structural performance of machine tools. However, few mechanical models are established for vibration analysis of linear guideway when it is subjected to complex external loads. In this paper, we presented a five degrees of freedom dynamic model for investigating nonlinear vibration behavior of linear guideway subjected to external periodic excitation. The idea of coordinate transformation is adopted for the easier derivations of piecewise restoring force function and equation of motion. The numerical simulation shows a wide variety of fascinating phenomena linked to vibration system with the effects from harmonic excitation frequency and amplitude, preload and mass of carriage. The multi-period, quasi-period and chaotic motions are observed by the characterization tools of bifurcation diagram and 3-D frequency spectrum. Moreover, the dynamic experiments are presented for verifying the proposed model. The analytical model developed here can be used for optimal design for high-precision linear guideway.

The residual antibiotics in different environmental media pose a serious threat to human health and the ecosystem. The high-efficient elimination of antibiotics is one of the foremost works. In this study, chloramphenicol (CAP) was eliminated efficiently by electrocatalytic advanced oxidation process with carbon nanotubes/agarose/indium tin oxide (CNTs/AG/ITO) electrode. The influences of different experimental parameters on the degradation efficiency were systematically studied. Under the optimal conditions (4 V potential, 10 wt% CNTs dosage, and pH = 10), the maximum degradation efficiency of CAP (20 mg L− 1) achieved 88% within 180 min. Besides, the electrocatalytic degradation pathway and mechanism for CAP were also investigated, •O2− played a major role in the process of electrocatalytic degradation. Based on the QSAR (quantitative structure-activity relationship) model, the toxicities of CAP and identified intermediates were analyzed. Compared with the parent compound, the maximal chronic toxicity of intermediate ((E)-3-(4-nitrophenyl)prop-1-ene-1,3-diol) for daphnid increased 197-fold. Besides, the hybrid toxicity of the degradation system was further confirmed via disk agar biocidal tests with Escherichia coli ATCC25922, which changed slightly during the degradation process. Based on the above results, it is worth noting that the degradation pathway and toxicity assessment should be paid more attention to the treatment of antibiotic wastewater.

Background Nursing students are experiencing complex learning environments and will experience complex work environments in future clinical work, which lead to emotional problems easily. However, one’s beliefs about controlling their emotions portend a series of vital psychological outcomes. So, it is especially important to search for suitable tools to assess the emotion and regulation beliefs of nursing students and give timely intervention to improve their physical and mental health. This study aimed to translate the American version of the Emotion and Regulation Beliefs Scale (ERBS) into Chinese, revise the original scale and form a simplified version, and assess the reliability and validity of the brief Chinese version in nursing students. Methods The study adopted a cross-sectional design and the multistage sampling design. The ERBS was translated into Chinese, and the reliability and validity of the Chinese version were tested in 980 nursing students. Results The content validity index was 0.920. Exploratory factor analysis supported a three-factor model for the Chinese version of Brief-ERBS, and confirmatory factor analysis indicated that the model fit the Brief-ERBS well. Furthermore, the three-factors model was obtained by using exploratory factor analysis, explaining 51.023% variance, and the communalities of the items ranged from 0.359 to 0.680. With modified confirmatory factor analysis, the fit indices were chi-square/degree of freedom (CMIN/DF) = 4.092, goodness of fit index (GFI) = 0.949, adjusted goodness of fit index (AGFI) = 0.927, comparative fit index (CFI) = 0.913, incremental fit index (IFI) = 0.914, Tucker Lewis index (TLI) = 0.908, root-mean-square error of approximation (RMSEA) = 0.061. The two-tailed independent samples t-test showed the scores of the top (50%) and low (50%) groups reached the level of significance (P r = 0.972, P Conclusion The Chinese version of Brief-ERBS has good reliability and validity, and may be used for the beliefs about emotional management in Chinese nursing students.

The tumor microenvironment (TME), which is regulated by intrinsic oncogenic mechanisms and epigenetic modifications, has become a research hotspot in recent years. Characteristic features of TME include hypoxia, metabolic dysregulation, and immunosuppression. One of the most common RNA modifications, N6-methyladenosine (m6A) methylation, is widely involved in the regulation of physiological and pathological processes, including tumor development. Compelling evidence indicates that m6A methylation regulates transcription and protein expression through shearing, export, translation, and processing, thereby participating in the dynamic evolution of TME. Specifically, m6A methylation-mediated adaptation to hypoxia, metabolic dysregulation, and phenotypic shift of immune cells synergistically promote the formation of an immunosuppressive TME that supports tumor proliferation and metastasis. In this review, we have focused on the involvement of m6A methylation in the dynamic evolution of tumor-adaptive TME and described the detailed mechanisms linking m6A methylation to change in tumor cell biological functions. In view of the collective data, we advocate treating TME as a complete ecosystem in which components crosstalk with each other to synergistically achieve tumor adaptive changes. Finally, we describe the potential utility of m6A methylation-targeted therapies and tumor immunotherapy in clinical applications and the challenges faced, with the aim of advancing m6A methylation research.

The thermal effect has a significant influence on the performance of angular contact ball bearings and thus affects the motion accuracy and stability of spindle-bearing system of computerized numerical control (CNC) lathe. In this paper, a comprehensive coupled CNC lathe spindle-bearing model considering the thermal effect is proposed to predict the dynamic characteristics of system. The spindle is modeled as Timoshenko’s beam by considering the centrifugal force and gyroscopic effects. The bearing is analyzed by a five degrees-of-freedom (DOF) quasi-static model considering the thermal effect in order to obtain the static deformations and thermal deformations of rolling bodies. The dynamic differential equation of system is established by the finite element method. Runge–Kutta integral method is used to solve the system equation numerically to study its nonlinear dynamic behaviors. The correctness of thermal model of CNC lathe spindle-bearing system is verified by testing the housing temperature. The simulation values of system response considering thermal effect or not are compared with the experimental results, which shows that the proposed model is feasible. Moreover, the effects of key parameters such as rotational speed, pulley eccentricity and bearing preload on the nonlinear characteristics of system are investigated. Single-periodic, multi-periodic, quasi-periodic and chaotic motions are observed by time history curve, 3-D frequency spectrum curve, phase diagram, Poincare section and bifurcation diagram under different operating conditions. The analytical model developed here can be also helpful to the design and optimization of CNC lathe spindle-bearing system.

The application of organic fertilizers such as crop straw and manure is a feasible practice to alleviate the adverse effects caused by chemical fertilizers, and such alleviation is reflected mainly on soil microorganisms. However, our understanding of the short-term impacts of different organic materials combined with chemical fertilizer on soil fertility, bacterial and fungal abundances, and community compositions is limited. An acidic paddy field experiment in South China under three short-term fertilization regimes with equal amounts of inorganic fertilizers: chemical fertilizer (NPK), chemical fertilizer combined with cattle manure (NPKM), and chemical fertilizer combined with rice straw (NPKS) were investigated. Soil chemical properties were measured to analyze the effects of fertilization regimes on soil nutrients. Real-time quantitative PCR and MiSeq sequencing based on bacterial 16S rRNA gene and fungal internal transcribed spacer (ITS) sequence were employed to compare the bacterial and fungal abundances and community compositions under different fertilization regimes. The NPKM treatment significantly increased soil organic matter, nitrogen, and phosphorus contents compared with the NPK treatment. Also, manure application stimulated bacterial and fungal growth and distinctly shaped bacterial and fungal communities compared with chemical fertilizer alone. However, the incorporation of rice straw into soil had minor effects on soil nutrients, microbial abundance, and community composition. Redundancy analysis and variation partitioning analysis indicated that soil nutrients (e.g., SOM, available N, and P) and salinity (e.g., calcium and magnesium ions) together influenced soil bacterial and fungal communities. These results implicated a more prominent role of manure than rice straw in increasing soil fertility, bacterial and fungal abundances, and shaping microbial community distributions in this acidic paddy soil under short-term fertilization.

Knowledge of sex determination has important implications in physiology, ecology and genetics, but the evolutionary mechanisms of sex determination systems in turtles have not been fully elucidated, due to a lack of reference genomes. Here, we generate a high-quality genome assembly of Asian yellow pond turtle (Mauremys mutica) using continuous long-read (PacBio platform), Illumina, and high-throughput chromatin conformation capture (Hi-C) technologies. TheM.muticahaplotype has a genome size of 2.23 Gb with a contig N50 of 8.53 Mb and scaffold N50 of 141.98 Mb. 99.98% sequences of the total assembly are anchored to 26 pseudochromosomes. Comparative genomics analysis indicated that the lizard-snake-tuatara clade diverged from the bird-crocodilian-turtle clade at approximately 267.0–312.3 Mya. Intriguingly, positive selected genes are mostly enriched in the calcium signaling pathway and neuroactive ligand-receptor interaction, which are involved in the process of temperature-dependent sex determination. These findings provide important evolutionary insights into temperature-dependent sex determination system.

Occasionally, the drainage tube could not be removed because it was inadvertently sutured during the closure of the wound, which presents a dilemma for surgeons. Here, we share a simple and convenient solution: using endoscopic punching forceps to remove the sutured tube, providing a relatively simple and convenient option for surgeons.

Nitrate (NO3−) leaching has been recognized as a worldwide problem, and NO3− is a major pollutant in ground and surface waters. The gradual leaching of residual NO3− into soil layers below the root zone is the main way of nitrogen (N) loss in cropping systems. The interception of NO3− by subsurface roots is crucial for crops or vegetables to utilize N. However, few studies were focused on the mechanisms of NO3− leaching under intercropping of deep-rooted and shallow-rooted plants. In a greenhouse production system, we selected deep-rooted and shallow-rooted plants for single-season intercropping planting experiments (MP, monoculture of pepper; IPA, intercropping of pepper and alfalfa; IPM, intercropping of pepper and maize). Plants were grown in core drainage lysimeters for 4 months, and leachate was collected by soil solution samplers. The results revealed N transformations between monoculture and intercropping systems by comparing NO3− leaching, N use efficiency, and microbes involved in nitrification. NO3− accumulation mainly occurred in 25–40-cm soil layer, which was affected by root morphology. Compared with monoculture, intercropping reduced NO3− leaching, in particular, pepper/maize intercropping significantly reduced NO3− leaching losses. In deep soil layers, roots of alfalfa and maize were more developed than those of the other crops, which made this corresponding intercropping system more effective in absorbing N in the subsoil. N uptakes of pepper/alfalfa intercropping and pepper/maize intercropping were 19% and 28% higher than that from the monoculture, respectively. Ammonia oxidizing bacteria (AOB) were significantly stimulated with planting especial in the topsoil, while ammonia oxidizing archaea (AOA) decreased with planting along the soil profile. These results indicated that lush plant roots immobilized N from the deep soil and thus improved N use efficiency and reduced NO3− leaching in the deep-rooted and shallow-rooted intercropping system. Intercropping of shallow-rooted pepper with deep-rooted alfalfa can enhance root nutrient absorption in deep soil layers, increasing N use efficiency and thus reducing NO3− leaching. The nitrification process in the intercropped soil was mainly regulated by AOB.

SG3 , an R2R3 MYB protein coding gene that tightly linked to a major QTL GS3 , negatively regulates grain length while dependent on the status of GS3 in rice. It is often very difficult to isolate a minor QTL that is closely linked to a major QTL in rice. In this study, we focused on the isolation of a minor grain length QTL, small grain 3 (SG3), which is closely linked to the major QTL grain size 3 (GS3). The genetic effect of SG3 on grain length was dependent on GS3 status. Its genetic effect was larger in the presence of nonfunctional sg3 than functional SG3. A large number of near-isogenic F2 plants in which GS3 was fixed with nonfunctional alleles were developed to clone SG3. A gene encoding an R2R3 MYB domain transcriptional regulator was identified as the candidate gene for SG3. SG3 overexpression and knockdown plants showed shortened and elongated grains, respectively, which demonstrated that SG3 acts as a negative regulator of grain length. SG3 was preferentially expressed in panicles after flowering, and SG3 acted as a transcription activator. Comparative sequencing analysis identified a 12-bp insertion in the third exon of NYZ that led to a frameshift and resulted in a premature stop codon. The insertion/deletion was associated with grain length in the presence of functional GS3 in the indica subspecies. SG3 and GS3 were frequently in coupling phase in indica rice, making them good targets for the breeding of cultivars with short or long grains. The isolation of the SG3 MYB gene provides new gene resource and contributes to the regulatory network of grain length in rice.

Long-term application of chemical fertilizers causes soil degradation and nitrogen (N) loss, but these effects could be alleviated by organic fertilizers. In addition, crop rotation is a feasible practice to increase soil fertility, soil quality and crop yields comparing with monocultural cropping patterns. However, questions remain concerning how the soil microbiome responds to different manure application rates under crop rotations. Here, we collected soil samples from a rice-rape system to investigate the response of the soil microbiome to nine years of pig manure application at different rates (CK: 0 kg ha-1, M1: 1930 kg ha-1, M2: 3860 kg ha-1 and M3: 5790 kg ha-1). Our results revealed that the bacterial α-diversity (Chao1 and Shannon index) in the rape season increased first and then decreased with increasing manure application rates, and a high manure load tended to decrease the bacterial α-diversity in the rice season. Long-term manure application enriched some copiotrophic bacteria, such as Proteobacteria and Actinobacteria, while it decreased the relative abundance of Nitrospirae. Redundancy analysis (RDA) and the Mantel test indicated that soil pH, TC, TN, AP, C/P and N/P ratios were the main factors influencing bacterial communities. Moreover, network analysis showed that a low manure application rate shaped a complexly connected and stable bacterial community, while higher manure application rate decreased the stability of the bacterial network. These findings improve our understanding of bacterial responses to longterm manure application under crop rotations and their relationships with soil factors, especially in the context of increasing fertilizer inputs.

In this paper, we report a facile and green method to synthesize Au nanorods (AuNRs)/graphene oxide (GO) nanocomposites. In this approach, cetyltrimethylammonium bromide (CTAB) acted not only as a shape-directing agent but also as an assembling agent. The AuNRs/GO nanocomposites were prepared through electrostatic self-assembly between CTAB-capped positively charged AuNRs and negatively charged GO in an aqueous solution without introducing other assembling agents or surfactants. The catalytic performance of the obtained catalysts is evaluated with TOF, TOF1/2 and kapp values. Due to the increased effectiveness from the charge-mediated assembly, these AuNRs/GO nanocomposites showed high performance in the catalytic reduction of 4-nitrophenol to 4-aminophenol. The AuNRs/GO ratio was optimized, and the nanocomposite with a mass ratio 1:0.4 showed the best catalytic activity, achieving a kapp value of 1.69 min−1, which was not only 19.7 times better than the AuNRs, but also significantly better than the catalytic performance of Au/graphene and Au/GO composites reported in the literature.

The review summarizes the functions of the plant special transcription factors CCT family genes in multiple traits and discusses the molecular breeding strategies with CCT family genes in the future. Plants integrate circadian clock and external signals such as temperature and photoperiod to synchronize flowering with seasonal environmental changes. This process makes cereal crops including short-day crops, such as rice and maize, and long-day crops, such as wheat and barley, better adapt to varied growth zones from temperate to tropical regions. CCT family genes involve circadian clock and photoperiodic flowering pathways and help plants set a suitable flowering time to produce offspring. Beyond the flowering time, CCT family genes in cereal crops are associated with biomass and grain yield. Moreover, recent studies showed that they also associate with photosynthesis, nutrition use efficiency and stress tolerance. Here, we systematically review the progress in functional characterization of CCT family genes in flowering, geographical adaptation and grain yield formation, raise the core questions related to their molecular mechanisms and discuss how to practice them in genetic improvement in cereal crops by combining gene diagnosis and top-level design.

Previous studies suggest that organic carbon (C) and nitrogen (N) can stimulate soil nitrification, but whether autotrophic or heterotrophic nitrification is stimulated and who are active nitrifiers for the nitrification activity is still in debate. We elucidated which nitrification dominated and the active nitrifiers during the decomposition of rice callus. 15N-labeled callus and acetylene (C2H2) inhibition were used to explore the autotrophic or heterotrophic nitrification during the decomposition of callus and DNA-based stable isotope probing (SIP) and high-throughput sequencing were used to investigate the active nitrifiers. Autotrophic nitrification dominated the nitrification activity, driven by oxidation of ammonia (NH3) produced from mineralization of the callus-derived organic N. Callus significantly stimulated nitrification activity, which was paralleled by changes in the abundance and community composition of AOA. DNA-SIP further demonstrated that the active AOA outnumbered their bacterial counterparts in the 13C-DNA from the soil with callus amendment. Phylogenetic analysis revealed the functional importance of soil fosmid 29i4-like and 54d9-like AOA within soil group 1.1b during the active nitrification with callus cells. NH3 released from the mineralization of callus was the main substrate for autotrophic nitrification and preferentially stimulated the growth of AOA within group 1.1b in the paddy soil.

Wear between balls and races has significant effects on the dynamic characteristics of bearing, which is the main reason to cause bearing failure. Some existing contact stiffness models were established to study the dynamic characteristics of bearing. However, the wear of bearing has been rarely investigated due to the complexities of contact load and wear mechanism. This paper presents a new dynamic wear simulation model of angular contact ball bearings mounted in pairs to solve this problem. A final contact stiffness model is established based on the wear model. The effects of running distance, horizontal load, preload, initial contact angle, number and diameter of balls on wear performances are analyzed. A generalized time-varying and piecewise-nonlinear dynamic model of angular contact ball bearings is established to perform an accurate investigation on its dynamic characteristics, especially considering the coupling effects of wear and rolling contact. The effects of wear on the contact stiffness and nonlinear dynamic characteristics are analyzed according to the dynamic model. Additionally, the variations of the contact stiffnesses and frequency responses with different preloads are discussed and the results indicate that parameter selection has significant effects on the wear and nonlinear response.

Although nanosheets of the transition metal dichalcogenides MoS2 have been the subject of extensive attention and research due to their unique properties, little research has been conducted on hybrid-phase MoS2 (1T@2H-MoS2), which has high photocatalytic properties. In this study, we prepared 1T@2H-MoS2 nanosheets loaded with Au nanoparticles (NPs) which exhibited high photocatalytic properties by a simple hydrothermal method, and the photocatalytic degradation of methylene blue by the 1T@2H-MoS2/Au nanosheets under visible light was 91.2%. This high degradation efficiency was due to the introduction of the Au NPs to produce localised surface plasmon resonance, which enhances the visible light absorption of 1T@2H-MoS2. The combination of a high content of the 1T phase and the Au NPs accelerates the transfer of photogenerated electrons, which inhibits the recombination of photogenerated electron–hole pairs and allows more electrons to participate in the catalytic reaction. The results showed that loading Au NPs on the 1T@2H-MoS2 nanosheets promoted the conversion of the 2H phase to the 1T phase, which effectively improved the visible light catalytic performance.

Since December 2019, the novel coronavirus SARS-CoV-2 pandemic (COVID-19) outbroke in Wuhan and spread in China. Here we aimed to investigate the clinical and radiological characteristics of COVID-19 cases. We collected and analyzed the clinical data of 172 hospitalized cases of COVID-19 who were diagnosed via qRT-PCR of nasopharyngeal swabs during January 2020 and February 2020. The chest images were reviewed by radiologists and respirologists. The older patients with COVID-19 in Henan Province had more severe disease and worse prognosis. The male sex, smoking history and Wuhan exposure of patients are not related to the severity or prognosis of COVID-19. Family gatherings were showed among 26.7% of patients. A greater proportion of patients in the severe group suffer from combined chronic diseases. CT results showed that most patients had bilateral lung lesions and multiple lung lobes. The lungs of severe patients are more damaged. Both the infection range and inflammatory factor levels are related to the poor prognosis. Antiviral drugs, immunoglobulin and traditional Chinese medicine are mainly used for the treatment of COVID-19 patients. The discharge rate of COVID-19 patients was 93.0%, and the mortality rate was 2.3%. Case type, lymphocyte ratio grade, and respiratory failure at admission are risk factors for poor prognosis, except for the number of infiltrating lung lobes. The results showed that severe disease process, lymphopenia and respiratory failure are risk factors for the COVID-19. Supplementary Information The online version contains supplementary material available at 10.1007/s13577-021-00499-y.

Biological particles in the operating room (OR) air environment can cause surgical site infections (SSIs). Various ventilation systems have been employed in ORs to ensure an ultraclean environment. However, the effect ofdifferent ventilation systems on the control ofbacteria-carrying particles (BCPs) released from the surgical staff during surgery is unclear. In this study, the performance of four different ventilation systems (vertical laminar airflow ventilation (VLAF), horizontal laminar airflow ventilation (HLAF), differential vertical airflow ventilation (DVAF), and temperature-controlled airflow ventilation (TAF)) used in an OR was evaluated and compared based on the spatial BCP concentration. The airflow field in the OR was solved by the Renormalization Group (RNG) k-ε turbulence model, and the BCP phase was calculated by Lagrangian particle tracking (LPT) and the discrete random walk (DRW) model. It was found that the TAF system was the most effective ventilation system among the four ventilation systems for ensuring air cleanliness in the operating area. This study also indicated that air cleanliness in the operating area depended not only on the airflow rate of the ventilation system but also on the airflow distribution, which was greatly affected by obstacles such as surgical lamps and surgical staff.

Exploiting dependencies between the labels is the key of improving the performance of multi-label classification. In this paper, we divide the utilizing methods of label dependence into two groups from the perspective of different ways of problem transformation: label grouping method and feature space extending method. As to the feature space extending method, we find that the common problem is how to measure the dependencies between labels and to select proper labels to add to the original feature space. Therefore, we propose a ReliefF-based pruning model for multi-label classification (ReliefF-based stacking, RFS). RFS measures the dependencies between labels in a feature selection perspective and then selects the more relative labels into the original feature space. Experimental results of 9 multi-label benchmark datasets shows that RFS is more effective compared to other advanced multi-label classification algorithms.

Paddy soil is one of the main sources of global nitrous oxide (N2O) emissions via multiple pathways regulated by different microbes. However, the relative contributions of N2O production pathways with the addition of organic carbon (C) in different paddy soils are poorly understood. 15N-stable isotope and acetylene (C2H2) inhibition were used to differentiate the relative contributions of autotrophic and heterotrophic nitrification (ANF and HNF) and denitrification (DNF) to N2O emissions in two paddy soils (acid vs. neutral soil) with glucose addition. HNF and DNF were the main N2O pathways which contributed between 85% to 100% of the total N2O production at 70% water filled pore space. Low soil pH inhibited soil nitrification and the activity of ammonia oxidizers compared with neutral paddy soil. Glucose reduced nitrification rate and stimulated N2O production significantly, mainly via DNF in the two paddy soils. Moreover, glucose increased the relative contribution of DNF to total N2O production in the first 7 days and total N2O amounts from HNF over the 14-day incubation. HNF and DNF rather than ANF dominated the N2O emissions regardless of soil pH. Glucose had a positive effect on N2O emissions by influencing HNF and DNF.

The aim of this study was to determine the responses of nitrifiers and denitrifiers to understand microbial pathways of nitrous oxide (N2O) emissions in grassland soils that received inputs of sheep excreta. Sheep dung and synthetic sheep urine were applied at three different rates, simulating a single, double, or triple overlapping of urine or dung depositions in the field. Quantitative PCR and high-throughput sequencing were combined with process-based modeling to understand effects of sheep excreta on microbial populations and on pathways for N2O production. Results showed that emissions of N2O from urine were significantly higher than from dung, ranging from 0.12 to 0.78 kg N2O-N ha−1 during the 3 months. The N2O emissions were significantly related to the bacterial amoA (r = 0.373, P

Linezolid is considered as a last-resort antimicrobial agent, the resistance of which is of great concern. The aim of this study was to investigate the mechanisms and transferability of linezolid resistance and molecular epidemiology of linezolid-resistant enterococcal isolates in Wenzhou, China. A collection of 1623 enterococcal strains, including 789 Enterococcus faecalis and 834 Enterococcus faecium, were isolated from our hospital during 2011-2016. Antimicrobial susceptibility testing and clinical data analysis were performed. Molecular mechanisms of linezolid resistance, including the existence of resistance genes cfr and optrA, as well as the mutations in 23S rRNA and ribosomal proteins L3, L4, and L22, were investigated by PCR and sequencing. Conjugation experiments were conducted, and epidemiological characteristics were analyzed by PFGE and MLST. In our study, 31 (3.93%) E. faecalis and 2 (0.24%) E. faecium exhibited resistance to linezolid. Risk factors correlated with linezolid-resistant enterococcal infections included gastrointestinal surgery hospitalization, urogenital disorders, tumor, diabetes, and polymicrobial infections. Among these isolates, 6 (18.18%) harbored cfr, 9 (27.27%) harbored optrA, and 18 (54.55%) co-harbored cfr and optrA. However, mutational mechanisms were not found in this study. Conjugation experiments demonstrated the transferability of cfr and optrA between Gram-positive and Gram-negative bacteria. The clone of these isolates was diverse and scattered. It is noteworthy that cfr and optrA were the main mechanisms of linezolid resistance in this study, posing a potential risk of spread of linezolid resistance. Strikingly, it reported firstly that the two transferable resistance genes cfr and optrA coexisted in the same E. faecalis isolates.

Hybrid-phase-MoS2 (1T@2H-MoS2) nanosheet-coated black TiO2 spheres (1T@2H-MoS2/B-TiO2) were prepared using a hydrothermal method and a chemical reduction method under an argon atmosphere. X-ray diffraction, transmission electron microscope, Raman spectra and X-ray photoelectron spectroscopy indicated the generation of the 1T@2H-MoS2 and black TiO2. The efficiency of the 1T@2H-MoS2/B-TiO2 core–shell structure degradation of rhodamine B (RhB) reached 98.0%. The high photocatalytic activity was due to the presence of 1T-MoS2, which accelerated the electron transfer to participate in the redox reaction. In addition, the presence of B-TiO2 suppressed the undesirable electron–hole recombination. Finally, the synergistic effect between 1T@2H-MoS2 and B-TiO2 promoted the separation of the photoelectron–hole pairs. Moreover, scavenger studies found that the hydroxyl radical (•OH) was the dominant reactive oxygen species in the degradation of RhB under visible light irradiation. The possible growth mechanism and photocatalytic mechanism are discussed in detail. The results of this study will contribute to the improvement in the visible light absorption and photocatalytic degradation of catalysts.

The dynamic behavior of octahedral gold nanoparticles (NPs) and nanoparticle clusters (NPCs) in aqueous solution is studied by in-situ liquid-cell transmission electron microscopy (TEM). The octahedral Au NPs/NPCs show preferential orientations in the liquid cell, due to the interaction with the SiNx window. The Au NPs show long-range reversible hopping and three-dimensional (3D) rotational motions in the liquid environment. At the same time, the Au NPCs and NPs perform slow stick-slip and stick-roll motions, respectively, with a centripetal trend. The centripetal motions were explained by a liquid evaporation-induced radial flow model, in which the NPCs/NPs trajectories are controlled by Stokes forces and surface friction by the silicon nitride window. The calculated radius-dependent force (Fc) on the NPCs/NPs shows a semi-linear correlation with the distance r between the NPCs/NPs and the center of mass, accompanied with stochastic fluctuations, in agreement with the model predictions. This work thus demonstrates the effectiveness of in situ liquid-cell TEM for the in-depth understanding of complicated liquid flow and force interactions in nanomaterials.

The graphene (GR)/TiO2 membrane was prepared by the sol-gel method and coated on the indium tin oxide (ITO) conductive glass, which showed high and stable photo(-electro)-catalytic activities to rhodamine B (Rh-B) in water. Characterization results showed that the GR was dispersed and wrapped in the needle-like TiO2. With GR/TiO2 membrane and simulated sunlight irradiation, the removal efficiency of Rh-B (10 mg l−1 and pH at 5.4) arrived at 87.6% within 300 min. However, the higher removal efficiency for Rh-B reached to 97.8% by the photo-electro-catalytic degradation with the applied voltage 4 v for 30 min. The ·OH that generated in the photo-catalytic degradation process were responsible for Rh-B decomposition. The ·O2− played the significant role in the photo-electro-catalytic degradation of Rh-B. Furthermore, the decarboxylation was also occurred in the photo-electro-catalytic degradation for the Rh-B in water except for the deethylation and hydroxylation in the photo-catalytic degradation. In addition, the toxicities of the intermediates were calculated using the ECOSAR program and the EPIWIN software. The results indicated that the toxicities of intermediates from photo-electro-catalytic degradation for the Rh-B were higher than photo-catalytic degradation, due to the generation of decarboxylate.

Carbon nanotubes (CNTs)/agarose (AG) membrane on the ITO (indium tin oxide) conductive glass, with high efficiency of electrocatalytic degradation for rhodamine B (Rh-B) in water, was prepared using an easy and green method. The prepared CNTs/AG membrane was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive spectra (EDS), infrared spectroscopy (IR), and electrochemical impedance spectroscopy (EIS). The results revealed that CNTs were dispersed in the AG membrane. Additionally, the electrocatalytic activities for Rh-B were conducted on the electrochemical workstation with a three-electrode system. Both initial pH and potential played an important role in the process of electrocatalytic degradation. At pH 3 and potential reaching 4 V, the removal rate of Rh-B (10 mg/L) in water achieved 96% within 20 min. The stability of the prepared CNTs/AG membrane was also investigated. Besides, the toxicities of the main intermediates from the electrocatalytic degradation for Rh-B were calculated using the ECOSAR program and EPIWIN software, and results indicated that the toxicities of some intermediates were higher than those of the parent pollutant (Rh-B). These findings provided a light-spot to simplify the preparation of efficient working electrode and emphasized the possible potential risks from intermediates at the same time.

Hip-joint CT images have low organizational contrast, irregular shape of boundaries and image noises. Traditional segmentation algorithms often require manual intervention or introduction of some prior information, which results in low efficiency and is unable to meet clinical needs. In order to overcome the sensitivity of classical fuzzy clustering image segmentation algorithm to image noise, this paper proposes a fuzzy clustering image segmentation algorithm combining Gaussian regression model (GRM) and hidden Markov random field (HMRF). The algorithm uses the prior information to regularize the objective function of the fuzzy C-means, and then improves it with KL information. The HMRF model establishes the neighborhood relationship of the label field by prior probability, while CRM model establishes the neighborhood relationship of feature field on the basis of the consistency between the central pixel label and its neighborhood pixel label. The experimental results show that the proposed algorithm has high segmentation accuracy.

N-doped black TiO2 spheres (N2–b-TiO2) were prepared by solvothermal reaction and calcination under a nitrogen atmosphere. N-doping introduces new impurity levels above the TiO2 valence band, enhancing the effective absorption of visible light. The presence of OV and Ti3+ in the disordered outer layer inhibits electron–hole pair recombination, and the spherical structure provides many active sites. Those were confirmed by X-ray diffraction, Fourier transform IR, X-ray photoelectron spectroscopy and High-resolution transmission electron microscopy. UV–visible absorption indicates that the nitrogen-doped black TiO2 samples has a reduced band gap and a strong visible light absorption, which is attributed to the doping of OV, Ti3+ and N. The photocatalytic efficiency of the best sample (N2–b-TiO2) for potassium dichromate and rhodamine B was 96.2% and 99.5%, respectively. The superoxide radical (•O2−) played a dominant role in photocatalysis by scavenging experiments. Thus, a photocatalytic mechanism with reduced band gap has been proposed. This study provides a simple and practical method for non-metallic doping to control the photocatalytic performance of semiconductors.

Interactions between predators and their prey are influenced by the habitats they occupy. In freshwater ecosystems, submerged vegetation provides protection for prey compared to unvegetated substrata. Using submerged plants (Hydrilla verticillata) as a refuge for Chinese bitterling (Rhodeus sinensis), a native fish, we conducted a series of laboratory experiments to test the impact of structural complexity and prey density on predation rate. We found that the number of Chinese bitterling eaten by alien crayfish (Procambarus clarkii) decreased with the increasing structural complexity and increased with prey density. Similar reductions in predation rate with increased habitat complexity occurred at all three different prey densities. Our study indicates that structural complexity can decrease the crayfish predation on freshwater fishes.

Background Diabetic foot ulcer (DFU) is a severe complication of diabetes, preceding most diabetes-related amputations. DFUs require over US$9 billion for yearly treatment and are now a global public health issue. DFU occurs in the setting of ischemia, infection, neuropathy, and metabolic disorders that result in poor wound healing and poor treatment options. Recently, stem cell therapy has emerged as a new interventional strategy to treat DFU and appears to be safe and effective in both preclinical and clinical trials. However, variability in the stem cell type and origin, route and protocol for administration, and concomitant use of angioplasty confound easy interpretation and generalization of the results. Methods The PubMed, Google Scholar, and EMBASE databases were searched and 89 preclinical and clinical studies were selected for analysis. Results There was divergence between preclinical and clinical studies regarding stem cell type, origin, and delivery techniques. There was heterogeneous preclinical and clinical study design and few randomized clinical trials. Granulocyte-colony stimulating factor was employed in some studies but with differing protocols. Concomitant performance of angioplasty with stem cell therapy showed increased efficiency compared to either therapy alone. Conclusions Stem cell therapy is an effective treatment for diabetic foot ulcers and is currently used as an alternative to amputation for some patients without other options for revascularization. Concordance between preclinical and clinical studies may help design future randomized clinical trials.

Carbon nanotubes (CNTs), graphene (GA) and carbon nanospheres (CNSs) were prepared respectively using grass (Festucaarundinace) as the sole carbon resource by solvothermal method and characterized as adsorbent and photocatalyst for 2-chlorophenol (2-CP) removal in water. With H2O2/HNO3/H2SO4, the CNTs were firstly produced from grass (Festucaarundinace) at 300 °C by hydrolysis and oxidization, the CNTs were secondly opened to form the GA by oxidization at 400 °C and the GA was lastly rolled-up to form the CNSs by oxidization at 500 °C. All adsorption equilibration of the CNTs, GA and CNSs for 2-CP were achieved within 120 min and 60.35%, 20.12% and 76.22% of 2-CP (5 mg L−1, pH = 6.3) were adsorbed, respectively. Furthermore, the high removal rates of 2-CP were about 88.23%, 92.90% and 79.64% by the CNTs, GA and CNSs, after 120 min adsorption and 160 min irradiation. On the basis of these results, the CNSs were suitable for removal 2-CP as adsorbent and the GA was suitable as photocatalyst. The photooxidation of 2-CP was mainly initiated by O2·− or ·OH which was generated from the combine with simulated sunlight and the CNTs or GA, respectively. However, the CNTs was not suitable for removal 2-CP owing to the increasing toxicity.

In this work, a novel electrochemiluminescence (ECL) sensor based on Au nanoparticles-hybridized Pb (II)-β-cyclodextrin (Pb-β-CD) metal-organic framework for detecting hexavalent chromium (Cr(VI)) was developed. Pb-β-CD shows excellent ECL behavior and unexpected reducing ability towards Au ions. Au nanoparticles could massively form on the surface of Pb-β-CD (Au@Pb-β-CD) without use of any additional reducing agent. In the presence of coreactant K2S2O8, the ECL emission of Pb-β-CD was enhanced by the formation of Au nanoparticles. Cr(VI) can collisionally quench the ECL behavior of Au@Pb-β-CD/S2O82− system and the detection mechanism was investigated. This ECL sensor is found to have a linear response in the range of 0.01–100 μM and a low detection limit of 3.43 nM (S/N = 3) under the optimal conditions. These results suggest that metal-organic framework Au@Pb-β-CD has great potential in extending the application in the ECL field as an efficient luminophore.

High dense Ba0.5Sr0.5TiO3 ceramics with Al2O3 additives have been prepared by a method combined the sol–gel process and the solid state reaction. Phase compositions, microstructure and dielectric behaviors are investigated systematically. Our experiment results reveal that the Al2O3 additives reduce the dielectric constant slightly and increase the breakdown strength greatly due to the refined microstructure and the formation of the second phases. The estimated energy density of Ba0.5Sr0.5TiO3 ceramics with optimized Al2O3 additives is improved by 1.5 times as compared with that of pure Ba0.5Sr0.5TiO3 ceramics.

The Wnt/β-catenin signaling pathway is a highly conserved pathway in organism evolution and regulates many biological processes. Aberrant activation of the Wnt/β-catenin signaling pathway is closely related to tumorigenesis. In order to identify potent small molecules to treat the over-activated Wnt signaling-mediated cancer, such as colon cancer, we established a mammalian cell line-based reporter gene screening system. The screen revealed a diterpenoid derivative, 15-oxospiramilactone (NC043) that inhibits Wnt3a or LiCl-stimulated Top-flash reporter activity in HEK293T cells and growth of colon cancer cells, SW480 and Caco-2. Treatment of SW480 cells with NC043 led to decreases in the mRNA and/or protein expression of Wnt target genes Axin2, Cyclin D1 and Survivin , as well as decreases in the protein levels of Cdc25c and Cdc2. NC043 did not affect the cytosol-nuclear distribution and protein level of soluble β-catenin, but decreased β-catenin/TCF4 association in SW480 cells. Moreover, NC043 inhibited anchorage-independent growth and xenograft tumorigenesis of SW480 cells. Collectively these results demonstrate that NC043 is a novel small molecule that inhibits canonical Wnt signaling downstream of β-catenin stability and may be a potential compound for treating colorectal cancer.