Climate and geochemistry at different altitudes influence soil fungal community aggregation patterns in alpine grasslands.

Fungi represent key ecosystem factors that affect plant growth and development and improve soil structure and fertility. Due to changes in environmental conditions, fungi show strong spatial heterogeneity along altitudinal gradients. Current knowledge of the driving mechanisms and effects of soil fungal community construction at high altitudes is very limited on a regional scale. We collected soil samples from alpine grasslands at six altitudinal gradients (2813-5228 m) in the high-altitude area of the Qinghai-Tibet Plateau. The horizontal distance of the sampling zone spanned 1500 km. Distribution patterns, key influencing factors for soil fungal diversity, and dominant mechanisms of ecological processes in the alpine grasslands were analyzed. We found that the diversity of the soil fungal communities was significantly different at different altitudes; with increasing altitude, the number of fungal species increased. Mucoromycota was better adapted to alpine grassland ecosystems at altitudes of above 4000 m. Dispersal limitation was the main ecological control process among stochastic processes. With the increase of altitude, the dominant role of dispersal limitation gradually decreased, and the proportion of other random processes such as ecological drift gradually increased. In this study, soil geochemical factors (soil organic carbon, SOC; total phosphorus, TP) mainly influenced the composition of the fungal community in the low altitude region, while climatic factors (mean annual temperature, MAT) were the key factors and main driving forces for the composition of the soil fungal community in the alpine meadow in the high altitude region. This study supplements the information on the biogeographic distribution patterns and environmental drivers of fungal communities along altitudinal gradients at high altitudes on a regional scale. Our results highlight the effects of temperature change on fungal community composition in high altitude regions of alpine grasslands. Subsurface fungal communities should be considered when predicting the function of alpine grassland ecosystems under future climate change.

[Stable angina pectoris of coronary heart disease treated with different acupuncture and moxibustion therapies: a network Meta-analysis].

To compare the clinical efficacy among different acupuncture and moxibustion therapies on stable angina pectoris (SAP) of coronary heart disease by means of network Meta-analysis. The articles of randomized controlled trial (RCT) for SAP of coronary heart disease treated with acupuncture and moxibustion therapies were searched from PubMed, Web of Science, Cochrane Library, CNKI, Wanfang database and VIP database from May 1, 2002 to May 1, 2022. The quality of them was assessed with the risk of bias assessment tool of Cochrane 5.3, and the network Meta-analysis was undertaken with Stata 13.1 software. A total of 29 articles were included with the acupuncture and moxibustion therapies involved, e.g. acupuncture, acupoint application and moxibustion. In comparison with the simple routine western medication, the effective rate was better on SAP treated with the combined treatments, in which, acupoint application, moxibustion, acupuncture and intradermal needling were combined with routine western medication (P<0.05). Of those combined treatments, the combination of the acupoint application with routine western medication had high probability, suggesting the optimal regimen (area under the curve [SUCRA]=0.711, P<0.05). The effective rate of acupuncture combined with routine western medication for ECG improvement was better than that of routine western medication (P<0.05), and such combined treatment was high in probability, underlying its optimal treatment (SUCRA=0.800, P<0.05). Combined with routine western medication, acupuncture, acupoint application, moxibustion and intradermal needling all improve the clinical efficacy on SAP of coronary heart disease. But, with different outcomes considered, the optimal treatments may be different. It needs more multi-central and large-sample randomized controlled trials to validate these results.

Prognostic Significance of Triglyceride-Glucose Index for Adverse Cardiovascular Events in Patients With Coronary Artery Disease: A Systematic Review and Meta-Analysis.

Background: Insulin resistance (IR) represents a critical regulator in the development and progress of coronary artery disease (CAD). Triglyceride-glucose (TyG) index, a novel surrogate biomarker of IR, has been implicated in several cardiovascular diseases. Accordingly, we conduct a meta-analysis to elucidate the relationship between TyG index and adverse cardiovascular events in patients with CAD. Methods: To identify the studies examining the predictive capacity of the TyG index for adverse cardiovascular events in the setting of CAD, we performed a comprehensive literature retrieval of Scopus, PubMed, EMBASE, and Web of Science, from the inception of databases to October 5, 2021. We pooled the adjusted hazard ratio (HR) along with 95% CI using a random-effects model. The primary outcome was a composite of major adverse cardiovascular events (MACEs), including all-cause death, cardiovascular death (CV death), myocardial infarction (MI), stroke, hospitalization for unstable angina or heart failure, and revascularization. The secondary outcomes were all-cause death, CV death, MI, stroke, and revascularization. Additionally, we conducted subgroup analyses stratified by diabetes status, age, body mass index (BMI), low-density lipoprotein cholesterol (LDL-C), category of TyG index, sample size, follow-up duration, and study design. Results: About 12 studies involving 28,795 patients with CAD were finally taken into the quantitative analysis. Our findings showed that there was a 2.14-fold higher risk of MACEs among CAD populations in the highest TyG group compared with those in the lowest TyG group (HR: 2.14, 95% CI: 1.69-2.71, P < 0.001). A greater risk of MACEs was observed in participants with higher BMI than those with lower BMI (P = 0.03 for interaction). In the analysis of secondary outcomes, we also observed a markedly increased risk of MI, stroke, and revascularization in the highest TyG group compared with the lowest TyG group. No evidence of a significant association between TyG index and CV mortality or all-cause mortality in patients with CAD was identified. Conclusions: The elevated TyG index is a promising predictive factor of adverse cardiovascular events in patients with CAD. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO, identifier: CRD42021228521.

A Meta-Analysis of Growth Differentiation Factor-15 and Prognosis in Chronic Heart Failure.

Background: Previous studies had reported increased circulating concentrations of growth differentiation factor-15 (GDF-15) in chronic heart failure (CHF), suggesting the potential prognostic significance of GDF-15 in this setting. To verify the relationship between the circulating GDF-15 levels and prognosis of CHF patients, we conducted an updated evidence-based meta-analysis. Methods: A comprehensive literature retrieval of PubMed, EMBASE, and Cochrane library was performed to collect the qualified studies that analyzed the prognostic value of GDF-15 in CHF from the inception of these online databases to September 25, 2021. The hazard ratio (HR) calculated for logGDF-15 of all-cause death and the related 95% confidence interval (CI) in multivariate analysis were used to measure the effect size. Additionally, subgroup analyses stratified by characteristics of the study participants were conducted for incremental evidence of GDF-15 in CHF with different clinical status. Results: A total of ten eligible studies involving 6,244 CHF patients were finally taken into the quantitative analysis. Results in the random-effects model indicated that there was an increased risk of 6% in all-cause mortality with a per 1LnU increase in baseline GDF-15 concentration (HR: 1.06, 95% CI: 1.03-1.10, P < 0.001). In stratified analyses, the association of GDF-15 with risk of all-cause mortality was found among chronic ischemic HF patients (HR:1.75, 95%CI: 1.24-2.48, P = 0.002), while the association was not found among chronic nonischemic HF patients (HR:1.01, 95%CI: 1.00-1.02, P = 0.219). Conclusion: The elevated GDF-15 is associated with an increased risk of all-cause mortality in CHF, especially, among CHF patients with ischemic etiology. The circulating GDF-15 might be a prognostic indicator in CHF patients. Registration Number: https://www.crd.york.ac.uk/PROSPERO; CRD42020210796.

Combination of Activating Blood Circulation and Detoxifying Chinese Medicines Played an Anti-Inflammatory Role in Unstable Angina Patients after Percutaneous Coronary Intervention: A Multicenter, Open-Labeled, Randomized Controlled Trial.

OBJECTIVE: To investigate the combined anti-inflammatory effect of activating blood circulation and detoxifying Chinese medicines in unstable angina (UA) patients. METHODS: This study was an open-labeled, randomized controlled trial conducted in 5 centers in Beijing. A total of 154 patients were randomized into two groups at a 1:1 ratio by random numbers. Based on the conventional treatment, patients in the activating blood circulation (ABC) group were treated with Guanxin Danshen Droping Pill (, 0.4 g, thrice daily), and patients in the activating blood circulation and detoxifying (ABCD) group were treated with Guanxin Danshen Droping Pill (0.4 g, thrice daily) and Andrographis tablet (0.2 g, thrice daily) for 4 weeks. The primary outcome was the serum level of high sensitive C reaction protein (hs-CRP), and the secondary outcome index included the serum levels of tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), soluble CD40 ligand (sCD40L), thrombomodulin (TM), the score of angina pectoris, the score of blood stasis syndrome, and the score of Chinese medicine symptoms, observed at week 0 and week 4. RESULTS: A total of 144 patients completed the trial (ABC group, n=70; ABCD group, n=74). There were no significant differences in the clinical baseline characteristics between the two groups. When compared with the ABC group, ABCD group showed better performance in reducing the level of inflammatory factors, especially hs-CRP (P<0.05), IL-6 (P<0.01) and TNF-α (P<0.01). In term of clinical symptoms, ABCD group played a better role in improving the scores of angina pectoris and blood stasis syndrome than ABC group (all P<0.05). CONCLUSIONS: The combination of Guanxin Danshen Dropping Pill and Andrographis tablet exert significant anti-inflammatory effect on UA patients, which is superior to single Guanxin Danshen Dropping Pill. (Registration No. ChiCTR-TRC-13004072).

Grid-based electron-solid interaction simulation for characterizing high-dimensional microstructures.

Three-dimensional (3D) micro- and nanostructural characterization using scanning electron microscope (SEM) and electron-solid interaction simulations (ESIS) has attracted broad interest in various research fields. However, 3D SEM-ESIS still faces key challenges in characterizing and modelling complex microstructures. In this paper, a new grid-based simulation scheme is developed to enable ESIS of complex microstructures. In contrast to the widely used region-based approach, the scheme presented here uses a grid of points to represent the spatial distribution of sample compositions, which allows numerical investigation of the effect of various geometric features such as interfacial diffusion zones and complex pores in the samples. The simulation results suggest that the interfacial diffusion zone and porosity significantly influence the scattering signals. It is believed that the presented scheme acts as a useful interpretation tool in understanding a wide range of materials and paves the way to SEM-based 3D reconstruction.

Exfoliation and dispersion of boron nitride nanosheets to enhance ordinary Portland cement paste.

Exfoliation and dispersion of boron nitride nanosheets (BNNSs) is the key to achieving desired reinforcing effects for ordinary Portland cement (OPC). Few studies exist, however, of the dispersion of BNNSs in a cement-induced alkaline environment and their effect on the mechanical properties of normal OPC paste. In this study, protocols were developed to prepare BNNS-reinforced OPC paste. Ultrasonication was used to exfoliate BNNSs from h-BN in water based suspensions. The addition of surfactants in the suspension was found to hinder the exfoliation of the BNNSs. The surfactants were, however, found to be essential for the dispersion of the BNNSs in pore solution. Among the three surfactants used in this study, polycarboxylate based superplasticizer was most suitable as it maintained over 40% of the BNNSs stable in the pore solution for 4 hours and increased the hydration flow peak over 20%. Atomic force microscopy results indicated that the thickness of the BNNSs was mostly under 10 nm. With the addition of 0.003 wt% BNNSs, the compressive and tensile strengths of the cement were increased by 13% and 8%, respectively. Besides the nucleation effect as indicated by hydration heat, pore structure refinement and chemical bonding were also found as the main reinforcing mechanisms of BNNSs in OPC matrix.

Quantification of evaporation induced error in atom probe tomography using molecular dynamics simulation.

Non-equilibrium molecular dynamics was used to simulate the dynamics of atoms at the atom probe surface and five objective functions were used to quantify errors. The results suggested that before ionization, thermal vibration and collision caused the atoms to displace up to 1Å and 25Å respectively. The average atom displacements were found to vary between 0.2 and 0.5Å. About 9 to 17% of the atoms were affected by collision. Due to the effects of collision and ion-ion repulsion, the back-calculated positions were on average 0.3-0.5Å different from the pre-ionized positions of the atoms when the number of ions generated per pulse was minimal. This difference could increase up to 8-10Å when 1.5ion/nm2 were evaporated per pulse. On the basis of the results, surface ion density was considered an important factor that needed to be controlled to minimize error in the evaporation process.

Direct Observation of 2D Electrostatics and Ohmic Contacts in Template-Grown Graphene/WS2 Heterostructures.

Large-area two-dimensional (2D) heterojunctions are promising building blocks of 2D circuits. Understanding their intriguing electrostatics is pivotal but largely hindered by the lack of direct observations. Here graphene-WS2 heterojunctions are prepared over large areas using a seedless ambient-pressure chemical vapor deposition technique. Kelvin probe force microscopy, photoluminescence spectroscopy, and scanning tunneling microscopy characterize the doping in graphene-WS2 heterojunctions as-grown on sapphire and transferred to SiO2 with and without thermal annealing. Both p-n and n-n junctions are observed, and a flat-band condition (zero Schottky barrier height) is found for lightly n-doped WS2, promising low-resistance ohmic contacts. This indicates a more favorable band alignment for graphene-WS2 than has been predicted, likely explaining the low barriers observed in transport experiments on similar heterojunctions. Electrostatic modeling demonstrates that the large depletion width of the graphene-WS2 junction reflects the electrostatics of the one-dimensional junction between two-dimensional materials.

Electrically tunable multiple Dirac cones in thin films of the (LaO)2(SbSe2)2 family of materials.

Two-dimensional Dirac physics has aroused great interests in condensed matter physics ever since the discovery of graphene and topological insulators. The ability to control the properties of Dirac cones, such as bandgap and Fermi velocity, is essential for various new phenomena and the next-generation electronic devices. On the basis of first-principles calculations and an analytical effective model, we propose a new Dirac system with eight Dirac cones in thin films of the (LaO)2(SbSe2)2 family of materials, which has the advantage in its tunability: the existence of gapless Dirac cones, their positions, Fermi velocities and anisotropy all can be controlled by an experimentally feasible electric field. We identify layer-dependent spin texture induced by spin-orbit coupling as the underlying physical reason for electrical tunability of this system. Furthermore, the electrically tunable quantum anomalous Hall effect with a high Chern number can be realized by introducing magnetization into this system.

Transition and stability of copolymer adsorption morphologies on the surface of carbon nanotubes and implications on their dispersion.

In this study, the adsorption morphologies as well as stability and transitions of a commercial dispersant copolymer (BYK 9076) on the surface of multiwalled carbon nanotubes (MWCNTs) were studied using Fourier transform infrared and UV-vis spectroscopy, dynamic light scattering, and electron microscopy techniques. The results show that the dispersion of carbon nanotubes in ethanol does not increase continuously with increasing copolymer/CNT ratio, which is correlated with the adsorption morphologies of the copolymer on the CNT surface. At a ratio of copolymer/CNT below 0.5, the morphology is random, shifting to a hemimicelle structure at a ratio from 0.5 to 1.0 while at ratios above 1.0, a cylindrical pattern is seen. The hemimicelle morphology is able to prevent the agglomeration of CNTs when the CNT concentration increases to 8.7 mg/mL, while cylindrical morphology is more efficient and stable to provide dispersion of CNTs at higher concentrations of CNTs.

Clinical efficacy of traditional chinese medicine on acute myocardial infarction: a prospective cohort study.

OBJECTIVE: To evaluate the clinical effects of Chinese medicine (CM) on acute myocardial infarction (AMI) with a prospective cohort study. METHODS: A total of 334 AMI patients from January 2007 to March 2009 were consecutively enrolled, and were assigned to a treatment group (169 cases) treated with combined therapy (CM for at least one month and Western medicine) and a control group (165 cases) with Western medicine alone. Clinical data including age, gender, smoking, medical history, infarction area, heart functional classification, CM syndrome scores, blood-stasis syndrome score, primary end-point (death, nonfatal myocardial infarction, and revascularization) and secondary end-point (ischemic stroke, rehospitalization due to angina, heart failure and shock), were collected. CM syndrome scores, blood-stasis syndrome score, primary end-point and secondary end-point were collected during the 6-month follow-up. Kaplan-Meier method was used for the survival analysis. The multifactor analysis was analyzed by Cox proportional hazards regression. RESULTS: At the end of 6-month the CM syndrome score and bloodstasis syndrome score in the treatment group were lower than those in the control group (P<0.01), especially the symptoms of chest pain, spontaneous perspiration and insomnia. Rehospitalization rate due to angina during the 6-month follow-up in the treatment group (2.96%) was lower than that in the control group (7.88%, P<0.05). Kaplan- Meier survival curve showed that event-free cumulated survival of rehospitalization due to angina during the 6-month follow-up in the treatment group was higher than that in the control group (Log rank 4.700, P=0.03). Cox regression analysis showed that heart dysfunction [hazard ratio (HR)=1.601, 95% CI=1.084-2.364, P=0.018] and diabetes mellitus (HR=1.755, 95% CI=1.031-2.989, P=0.038) were hazard factors to end-point, whereas CM (HR 0.405, 95% CI=0.231-0.712, P=0.002), percutaneous coronary intervention (PCI, HR=0.352, 95% CI=0.204-0.607, P<0.001) and angiotensin converting enzyme (ACE) inhibitors (HR=0.541, 95% CI=0.313-0.936, P=0.028) were protective factors. CONCLUSIONS: CM therapy could decrease CM syndrome scores and blood-stasis syndrome score, reduce the rehospitalization rate during 6-month follow-up due to angina. Heart dysfunction and diabetes mellitus were hazard factors to end-point, whereas CM, PCI and ACE inhibitors were protective factors.

Stable nontrivial Z2 topology in ultrathin Bi (111) films: a first-principles study.

Recently, there have been intense efforts in searching for new topological insulator materials. Based on first-principles calculations, we find that all the ultrathin Bi (111) films are characterized by a nontrivial Z(2) number independent of the film thickness, without the odd-even oscillation of topological triviality as commonly perceived. The stable nontrivial Z(2) topology is retained by the concurrent band gap inversions at multiple time-reversal-invariant k points with the increasing film thickness and associated with the intermediate interbilayer coupling of the Bi film. Our calculations further indicate that the presence of metallic surface states in thick Bi (111) films can be effectively removed by surface adsorption.

Water transport with a carbon nanotube pump.

Transportation of water molecules in a carbon nanotube based on an energy pump concept is investigated by molecular dynamics simulations. A small portion of the initially twisted wall of a carbon nanotube is employed to function as an energy pump for possible smooth transportation of water molecules. The momentum and resultant force on a water molecule and the corresponding displacement and velocity of the molecule are particularly studied to disclose the transportation process. The efficiency of the transportation is found to be dependent on the size of the energy pump. Once the process for the transportation of one molecule is elucidated, transportations of 20 water molecules are simulated to investigate the effect of the environmental temperature and fluctuations in the nanotube channel on the transportation. It is revealed that the accelerated period of multiple water molecules is longer than that in the transportation of a single water molecule. In addition, the fluctuations in the nanotube wall due to the buckling propagation and a higher environmental temperature will all lead to obvious decreases in the water velocity and hence retard the transportation process.

Applications of Piezoelectric Materials in Structural Health Monitoring and Repair: Selected Research Examples.

The paper reviews the recent applications of piezoelectric materials in structural health monitoring and repair conducted by the authors. First, commonly used piezoelectric materials in structural health monitoring and structure repair are introduced. The analysis of plain piezoelectric sensors and actuators and interdigital transducer and their applications in beam, plate and pipe structures for damage detection are reviewed in detail. Second, an overview is presented on the recent advances in the applications of piezoelectric materials in structural repair. In addition, the basic principle and the current development of the technique are examined.

Probing superexchange interaction in molecular magnets by spin-flip spectroscopy and microscopy.

The superexchange mechanism in cobalt phthalocyanine (CoPc) thin films was studied by a low temperature scanning tunneling microscope. The CoPc molecules were found to form one-dimensional antiferromagnetic chains in the film. Collective spin excitations in individual molecular chains were measured with spin-flip associated inelastic electron tunneling spectroscopy. By spatially mapping the spin-flipping channels with submolecular precision, we are able to explicitly identify the specific molecular orbitals that mediate the superexchange interaction between molecules.

High-resolution scanning tunneling spectroscopy of magnetic impurity induced bound states in the superconducting gap of Pb thin films.

Tunneling spectra for individual atoms and dimers of Mn and Cr adsorbed on superconducting Pb thin films were measured by a low temperature scanning tunneling microscope. Multiple-resonance structures within the superconducting gap on the adsorbates were resolved and interpreted as the magnetic impurity-induced bound states associated with different scattering channels. The experiment demonstrates a spectroscopic approach to characterizing the spin states of magnetic structures and exploring the competition between superconductivity and magnetism at the nanometer scale.

Manipulating the Kondo resonance through quantum size effects.

Manipulating the Kondo effect by quantum confinement has been achieved by placing magnetic molecules on silicon-supported nanostructures. The Kondo resonance of individual manganese phthalocyanine (MnPc) molecules adsorbed on the top of Pb islands was studied by scanning tunneling spectroscopy. Oscillating Kondo temperatures as a function of film thickness were observed and attributed to the formation of the thickness-dependent quantum-well states in the host Pb islands. The present approach provides a technologically feasible way for single spin manipulation by precise thickness control of thin films.

[Constructing a Cox proportional hazard regression model of prognosis factors of acute myocardial infarction by retrospective cohort study].

OBJECTIVE: To study the effects of the potential factors, including Chinese herbal decoction, on the long-term prognosis of acute myocardial infarction (AMI). METHODS: Previous clinical data of 162 patients with AMI were collected, who were followed-up to observe the important events for prognosis, as death and cardio-cerebral episode, and the Cox proportional hazards regression model was used to assess the relative factors. RESULTS: The degree of cardiac function (by New York grading) increased 1 grade when age increased for 10 years, and the relative hazardous degree (RHD) raised to 1.983 and 3.169. After treatment with Chinese herbal decoction and angiotensin converting enzyme inhibitor (ACEI), the RHD could be reduced to 0.177 and 0.161 respectively. Taking the important cardio-cerebral events, including death, as the endpoint, when age increased for 10 years, the cardiac function would increase for 1 grade and RHD of endpoint events increased to 2.021 and 1.863, if patients had history of anterior infarction, arrhythmia and diabetes mellitus, it increased to 2.903, 2.588 and 4.039 respectively. Chinese decoction and ACEI treatment could reduce it to 0.093 and 0.141 respectively. CONCLUSION: Age, heart failure, anterior infarction, arrhythmia and diabetes mellitus are the hazardous factors of the long-term prognosis of AMI, Chinese herbal decoction and ACEI are the protective factors.