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Background: Investigation into the immune heterogeneity linked with atherosclerosis remains understudied. This knowledge gap hinders the creation of a robust theoretical framework essential for devising personalized immunotherapies aimed at combating this disease. Methods: Single-cell RNA sequencing (scRNA-seq) analysis was employed to delineate the immune cell-type landscape within atherosclerotic plaques, followed by assessments of cell-cell interactions and phenotype characteristics using scRNA-seq datasets. Subsequently, pseudotime trajectory analysis was utilized to elucidate the heterogeneity in cell fate and differentiation among macrophages. Through integrated approaches, including single-cell sequencing, Weighted Gene Co-expression Network Analysis (WGCNA), and machine learning techniques, we identified hallmark genes. A risk score model and a corresponding nomogram were developed and validated using these genes, confirmed through Receiver Operating Characteristic (ROC) curve analysis. Additionally, enrichment and immune characteristic analyses were conducted based on the risk score model. The model's applicability was further corroborated by in vitro and in vivo validation of specific genes implicated in atherosclerosis. Result: This comprehensive scRNA-seq analysis has shed new light on the intricate immune landscape and the role of macrophages in atherosclerotic plaques. The presence of diverse immune cell populations, with a particularly enriched macrophage population, was highlighted by the results. Macrophage heterogeneity was intricately characterized, revealing four distinct subtypes with varying functional attributes that underscore their complex roles in atherosclerotic pathology. Intercellular communication analysis revealed robust macrophage interactions with multiple cell types and detailed pathways differing between proximal adjacent and atherosclerotic core groups. Furthermore, pseudotime trajectories charted the developmental course of macrophage subpopulations, offering insights into their differentiation fates within the plaque microenvironment. The use of machine learning identified potential diagnostic markers, culminating in the identification of RNASE1 and CD14. The risk score model based on these biomarkers exhibited high accuracy in diagnosing atherosclerosis. Immune characteristic analysis validated the risk score model's efficacy in defining patient profiles, distinguishing high-risk individuals with pronounced immune cell activities. Finally, experimental validation affirmed RNASE1's involvement in atherosclerotic progression, suggesting its potential as a therapeutic target. Conclusion: Our findings have advanced our understanding of atherosclerosis immunopathology and paved the way for novel diagnostic and therapeutic strategies. [ABSTRACT FROM AUTHOR]

A new efficient method for considering the long-range effect of reactive scattering processes in ultracold conditions has been developed using the time-dependent quantum wave packet theory, where the initial wave packet could be placed at a position near the interaction region. This is in contrast to previous methods, where the initial wave packet has to be placed far from the interaction region. The new method reduces the numerical effort significantly. Typical reactions, such as S(¹ D) + H2, D+ + H2, and 7 Li + 7 Li2 (v0 = 1,j0 = 0), under cold or ultra-cold conditions, are used to demonstrate the numerical efficiency of the new method. [ABSTRACT FROM AUTHOR]

The detection and identification of noise from moving parts inside a sealed cavity is crucial for ensuring the reliability of sealed equipment. However, traditional noise recognition methods struggle to meet the stringent demands for high detection accuracy. Inspired by the idea of ensemble learning, this paper proposes a noise recognition method that combines recognition results with high-dimensional mapping to enhance the recognition of noise. Firstly, a built noise identification experimental system is used to collect signals. Then, features are filtered and extracted based on acoustic emission principles and signal properties. Ultimately, a new fusion method is devised incorporating recognition results as new features into the original dataset and designing multiple layers of single algorithms based on their individual strengths to enhance the feature extraction capabilities of the algorithm. In the first layer of the fusion algorithm, CatBoost learns from the original dataset and incorporates its recognition results into the dataset. XGBoost then trains on the new dataset as the training set. Finally, the sparse output matrix generated by XGBoost is input into a logistic regression (LR) algorithm for training and prediction. The proposed method is verified by experiments on datasets and the results show that the accuracy of this method is higher than that of a single recogniser. It also performs better than current mature stacking fusion methods and mapping-based fusion methods. This fusion approach is of great significance for improving noise recognition accuracy and for innovating fusion methods. [ABSTRACT FROM AUTHOR]

Climate change is the dominant factor affecting the hydrological process, it is of great significance to simulate and predict its influence on water resources management, socio-economic activities, and sustainable development in the future. In this paper, the Xiying River Basin was taken as the study area, China Atmospheric Assimilation Driven Data Set (CMADS) and observation data from the Jiutiaoling station were used to simulate runoff of the SWAT model and calibrate and verify model parameters. On this basis, runoff change of the basin under the future climate scenario of CMIP6 was predicted. Our research shows that: (1) The contribution rates of climate change and human activities to runoff increase of the Xiying River are 89.17% and 10.83%, respectively. Climate change is the most important factor affecting runoff change of the Xiying River. (2) In these three different emission scenarios of SSP1-2.6, SSP2-4.5 and SSP5-8.5 in CMIP6 climate model, the average temperature increased by 0.61, 1.09 and 1.74 °C, respectively, in the Xiying River Basin from 2017 to 2050. Average precipitation increased by 14.36, 66.88, and 142.73 mm, respectively, and runoff increased by 15, 24, and 35 million m³, respectively. The effect of climate change on runoff will continue to deepen in the future. [ABSTRACT FROM AUTHOR]

Background: Cervical cancer has become a worldwide concern owing to its high incidence and mortality rates. To date, high-altitude areas of Tibet have not benefited from any large-scale cervical cancer screening programs. Therefore, we initiated a screening program to investigate the prevalence of human papilloma virus (HPV) and HPV genotype distribution to reveal cervical cancer and its precursor which lead to morbidity among women in the city of Nagqu in northern Tib3et. Methods: A total of 25,173 women were recruited to undergo HPV genotype tests between June and December 2019. Women infected with HPV 16 and/or 18 underwent colposcopy and histological examination. Women with other high-risk HPV type (hr-HPV) underwent cytological tests to determine whether to conduct further colposcopy and histological examination for diagnosis. HPV prevalence was calculated in the total population and further stratified according to various parameters, such as age group, area location (altitude level), and single or mixed infection status. The HPV genotype distribution was also investigated accordingly. Cervical lesions revealed by further colposcopic findings were also analyzed; high-grade and malignant lesion morbidities were calculated in total and in each county. Most data were collected and analyzed using descriptive and consistency check statistical methods, and a risk factor investigation for HPV infection was performed using logistic regression models. Results: The total HPV infection rate among women in Nagqu was 13.42%. Of the 25,173 women in the study, 999 (3.97%) were HPV 16/18 positive, 2,379 (9.45%) were other hr-HPV-positive, and 21,795 (86.58%) were HPV-negative. The five most common HPV genotypes, accounting for more than 60% of all HPV infections in Nagqu people, were HPV 16, 58, 31, 18, and 52. Tibetan women younger than 20 years and older than 60 years were the two age groups with the highest rates of HPV infection, 26.7% and 19.8%, respectively. Among the HPV-positive women, 2,656 (78.33%) were infected with a single strain and 732 (21.67%) were infected with multiple strains (more than two genotypes). HPV prevalence increased in high-altitude areas (positive rate highest in Nyima with an altitude of 5,000 m, 23.9%) and decreased in relatively low-altitude areas (positive rate lowest in Lhari with an altitude of 4,000 m, 6.6%). Multiple analyses showed that age, parity, age at first delivery, and altitude of residence were independent factors facilitating HPV infection in Tibetan women. High-grade and malignant cervical lesions revealed by histological findings were different among living locations, with the highest rates in Xainza, Baingoin, and Nyainrong, these being 2.019%, 1.820%, and 1.116%, respectively, among women in these areas. Conclusion: Our survey provides an overall perspective on HPV genotype infection and cervical lesions in women in northern Tibet. The data not only provide useful information for the treatment of cervical lesions but also has great value in terms of the primary and secondary prevention measures that can be taken for women living in these regions. [ABSTRACT FROM AUTHOR]

Local avalanche breakdown in an Ag/SiO2/p-Si:B/SiO2/Ag device was successfully detected by an in-situ detection circuit, which was composed of a p-Si:B substrate, two p-Si:B/SiO2/Ag metaloxide- semiconductor (MOS) structures formed on it, and a voltmeter. In our device, we observed a series of discharge peaks in the voltage-current curves which were corresponding to the generation of local plasmas in avalanche regimes. The generation of local plasmas led to a sudden increase in carriers concentration in the substrate which resulted in sudden voltage drops across the detection circuit, and then the MOS structures started to discharge which led to discharge peaks observed in V-I characteristics. More interesting, we found that the shape and amplitude of discharge peaks strongly depended on the setting of current steps of current source, owing to the discharging progresses. The avalanche breakdown based magnetoresistance (MR) effects were also studied. The value of MR in avalanche breakdown regime was about 40% which was two orders of magnitude higher than the MR value in other regimes. This work provides a simple and convenient method to explore the local avalanche breakdown effect and pave a way to acquire the MR effects based on avalanche breakdown. [ABSTRACT FROM AUTHOR]

Conventional 18-electron half-Heusler compounds with a high power factor are recognized as promising high-temperature thermoelectric materials, but the relatively high lattice thermal conductivity hinders their application. This work shows that a stoichiometric 19-electron TiNiSb compound is actually a combination of Ti0.75NiSb and impurities. Through decreasing the Ti content in TiNiSb, the obtained 18-electron Ti0.75NiSb has an increased Seebeck coefficient and a decreased electronic thermal conductivity due to the reduction of the carrier concentration. First-principles calculation shows that Ti0.75NiSb is a semiconductor with an energy gap of approximately 0.65 eV at the Fermi level. The existence of intrinsic Ti vacancy defects and the larger Grüneisen parameter are contributors to the low thermal conductivity of Ti0.75NiSb. Finally, Ti0.75NiSb shows a low lattice thermal conductivity of 1.08 W m1 K1, which is less than those of most half-Heusler compounds, and a maximum ZT of 0.36 at 873 K. This work demonstrates that Ti0.75NiSb is a promising thermoelectric material. [ABSTRACT FROM AUTHOR]

Aircraft engine load spectrum is the basis of stress analysis of components, structural design criteria, the durability test of components and complete engine and lifetime analysis. The main features are as follows: 1.it is difficult to obtain; 2. samples are insufficient; 3. parameters amount are huge, complex correlation. As a result, the lifetime prediction for aircraft engine and the new engine development is in urgent need of the simulation method of load spectrum. The mathematical model of aircraft engine, in specific, the use-related multiple parameters load spectrum was established by using the Principal Component Analysis (PCA). By using this model, simulation about the normal, non-normal and measured load spectrum of aero-engine can be made. In this paper, the simulated method of use-related multi-parameter load spectrum based on PCA can simulate the original load spectrum at any time by few sample measured and keep the correlation between parameters unchanged. The result indicated that the cumulative frequency curve of the simulated load spectrum and the cumulative frequency curve of the original load spectrum are in good agreement, which ensures that the fatigue damage caused by the simulation spectrum is consistent with the original spectrum. [ABSTRACT FROM AUTHOR]

Stable isotopes could be used as tracers to estimate the evaporation loss of surface water, which provides a new perspective for the research of hydrological processes. A systematic observation station has been built in the Shiyang River Basin, one of the most important inland river basins in Northwest China. This work conducted systematic observations on the river water, precipitation and hydrometeorology of the Shiyang River from 2017 to 2019. The evaporation loss of the Shiyang River is estimated to be 1.30% in the mountainous rivers, 2.28% in the mountainous reservoir (Xiying Reservoir), 2.87% in the oasis rivers, 7.97% in the oasis reservoir (Hongyashan Reservoir), and 41.37% in the terminal lake (Qingtu Lake). No matter in mountain or oasis, the evaporation loss of reservoir is much higher than that of the river, and the evaporation loss of the terminal lake is the largest. The evaporation loss of the river-lake continuum accounts for 14.66% of the total water volume of rivers and lakes (reservoirs). This work enriches the study of stable isotopes in the field of evaporation loss in the river-lake continuum, expands our understanding of the hydrological cycle in arid regions. [ABSTRACT FROM AUTHOR]

Ecosystems in arid areas are fragile and are easily disturbed by various natural and human factors. The purpose of this study is to clarify the hydrological and ecological processes of arid inland river basins in Eurasia and provide a scientific basis for their sustainable development. From 2015 to 2020, we took the Shiyang River Basin, which has the highest utilization rate of water resources and the most prominent contradiction of water use, as a typical demonstration basin to establish and improve the isotope hydrology observation system. The data in the observation system are classified by water type (precipitation, river water, lake water, groundwater, soil water, and plant water). Six observation systems with stable isotopes as the main observation elements, including river source region, oasis region, reservoir channel system region, oasis farmland region, ecological engineering construction region, and salinization process region, have been built, and meteorological and hydrological data have also been collected. We will gradually improve the various observation systems, increase the data of observation sites, and update the data set yearly. We can use these data to carry out hydrometeorological and ecological scientific research and provide a scientific basis for water resources utilization and ecological environment restoration in arid areas. The datasets are available at https://data.mendeley.com/datasets/d5kzm92nn3/1 (Zhu et al., 2021). [ABSTRACT FROM AUTHOR]

A new algorithm is proposed to compute quantum mechanically state-to-state differential cross sections for reactions involving four atoms in full dimensionality. This algorithm, which is based on the propagation of an initial state specific wave packet exclusively in reactant coordinates, extracts the S-matrix elements in the product channel by first interpolating the time-dependent wave packet using a collocation method at selected time intervals on the product coordinate grid and then projecting out the contributions of all final product states. This approach is efficient and accurate, particularly for reactions that are dominated by a product well or long-range interactions. Validation of this approach is demonstrated for the H2 + OH → H + H2O reaction. [ABSTRACT FROM AUTHOR]

State-to-state differential cross sections (DCSs) are computed quantum mechanically in full dimensionality for the title reaction using a reactant-product decoupling scheme. The DCSs are calculated at three collision energies of 0.25, 0.28, and 0.34 eV, corresponding to the existing experimental results. In good agreement with experiment, the calculated DCSs are dominated by backward scattering, thanks to the direct rebound mechanism, and the DOH product has two quanta of OD stretching vibration in the newly formed OD bond. In addition, the vibrational excitation of the OH reactant is found to result in a very different but predictable vibrational distribution of the DOH product. It is further shown at the state-to-state level that the DCSs of the DOH(νOD, νb, νOH) product state from the OH(ν = 1) reactant state resemble the ones of the DOH(νOD, νb, νOH-1) product state from the OH(ν = 0) reactant state, thanks to the spectator nature of the OH moiety. [ABSTRACT FROM AUTHOR]

The state-to-state quantum dynamics (Jtot = 0) of the HD + OH(2 = 0,1) reaction is studied using a reactant coordinate based method, which allows the analysis of both the H + DOH and D + HOH channels with a single propagation. The stretching vibration of the newly formed bond, namely, the OD bond in DOH and one OH bond in HOH, is excited, thanks to its strong coupling with the reaction coordinate at the transition state. On the other hand, the vibrational energy deposited into the OH reactant (2 = 1) is sequestered during the reaction in the spectator OH mode. The combined effect leads to the excitation of both the OD and OH stretching modes in the DOH product, and the dominance of the (002) normal-mode state population in the HOH product, which in the local-mode picture corresponds to the excitation of both OH bonds with one quantum each. The energy flow in this prototypical tetratomic reaction can be understood in terms of the sudden vector projection model. [ABSTRACT FROM AUTHOR]

A new accurate global potential energy surface for the ground electronic state of ozone [R. Dawes et al., J. Chem. Phys. 139, 201103 (2013)] was published fairly recently. The topography near dissociation differs significantly from previous surfaces, without spurious submerged reefs and corresponding van derWaals wells. This has enabled significantly improved descriptions of scattering processes, capturing the negative temperature dependence and large kinetic isotope effects in exchange reaction rates. The exchange reactivity was found to depend on the character of near-threshold resonances and their overlap with reactant and product wavefunctions, which in turn are sensitive to the potential. Here we present global "three-well" calculations of all bound vibrational states of three isotopic combinations of ozone (48O3, 16O2 18O, 16O2 17O) for J = 0 and J = 1 with a focus on the character and density of highly excited states and discuss their impact on the ozone isotopic anomaly. The calculations were done using a parallel symmetry-adapted Lanczos method with the RV3 code. Some comparisons were made with results obtained with the improved relaxation method implemented in the Heidelberg multi-configuration time-dependent Hartree code. [ABSTRACT FROM AUTHOR]

An efficient and accurate wave packet method is proposed for the calculation of the state-tostate S-matrix elements in bimolecular reactions involving four atoms. This approach propagates an initial state specific wave packet in reactant Jacobi coordinates. The projection in product channels is carried out on projection planes, which have one less degree of freedom, by transforming both the time-dependent wave packet and final product states into a set of intermediate coordinates. This reactant-coordinate-based method is more efficient than product-coordinate-based methods because it typically requires a smaller number of basis functions or grid points and allows the determination of S-matrix elements for multiple product channels from a single propagation. This method is demonstrated in calculating the (Jtot = 0) state-to-state S-matrix elements for both the abstraction and exchange channels of the H + H2O reaction. [ABSTRACT FROM AUTHOR]

Quantum state-to-state dynamics of a prototypical four-atom reaction, namely, Cl + H2O → HCl + OH, is investigated for the first time in full dimensionality using a transition-state wave packet method. The state-to-state reactivity and its dependence on the reactant internal excitations are analyzed and found to share many similarities both energetically and dynamically with the H + H2O → H2 + OH reaction. The strong enhancement of reactivity by the H2O stretching vibrational excitations in both reactions is attributed to the favorable energy flow into the reaction coordinate near the transition state. On the other hand, the insensitivity of the product state distributions with regard to reactant internal excitation stems apparently from the transition-state control of product energy disposal. [ABSTRACT FROM AUTHOR]

The O + O2 isotope exchange reactions play an important role in determining the oxygen isotopic composition of a number of trace gases in the atmosphere, and their temperature dependence and kinetic isotope effects (KIEs) provide important constraints on our understanding of the origin and mechanism of these and other unusual oxygen KIEs important in the atmosphere. This work reports a quantum dynamics study of the title reactions on the newly constructed Dawes-Lolur-Li-Jiang-Guo (DLLJG) potential energy surface (PES). The thermal reaction rate coefficients of both the 18O + 32O2 and 16O + 36O2 reactions obtained using the DLLJG PES exhibit a clear negative temperature dependence, in sharp contrast with the positive temperature dependence obtained using the earlier modified Siebert-Schinke-Bittererova (mSSB) PES. In addition, the calculated KIE shows an improved agreement with the experiment. These results strongly support the absence of the "reef" structure in the entrance/exit channels of the DLLJG PES, which is present in the mSSB PES. The quantum dynamics results on both PESs attribute the marked KIE to strong near-threshold reactive resonances, presumably stemming from the mass differences and/or zero point energy difference between the diatomic reactant and product. The accurate characterization of the reactivity for these near-thermoneutral reactions immediately above the reaction threshold is important for correct characterization of the thermal reaction rate coefficients. [ABSTRACT FROM AUTHOR]

The potential energy surfaces for the H + H2 exchange reaction are determined, using the standard Becke-3_parameter-Lee-Yang-Parr (B3LYP) hybrid exchange-correlation functional and the recently developed XYG3 type (xDH) doubly hybrid functionals. Quantum dynamical results calculated on these density functional theory surfaces revealed that the accuracy for the surfaces from the xDH functionals is quite satisfactory as compared to the benchmark Boothroyd-Keogh-Martin-Peterson-2 surface, whereas B3LYP is wholly inadequate in describing this simplest reaction despite the fact that it has been widely used to study reactions in complex systems. It is shown that further improvements can be achieved if the xDH functional parameters are fine-tuned to be reaction specific. [ABSTRACT FROM AUTHOR]

The title isotope exchange reaction was studied by converged time-dependent wave packet calculations, where an efficient 4th order split operator was applied to propagate the initial wave packet. State-to-state differential and integral cross sections up to the collision energy of 0.35 eV were obtained with 32O2 in the hypothetical j0 = 0 state. It is discovered that the differential cross sections are largely forward biased in the studied collision energy range, due to the fact that there is a considerable part of the reaction occurring with large impact parameter and short lifetime relative to the rotational period of the intermediate complex. The oscillations of the forward scattering amplitude as a function of collision energy, which result from coherent contribution of adjacent resonances, may be a sensitive probe for examining the quality of the underlying potential energy surface. A good agreement between the theoretical and recent experimental integral and differential cross sections at collision energy of 7.3 kcal/mol is obtained. However, the theoretical results predict slightly too much forward scattering and colder rotational distributions than the experimental observations at collision energy of 5.7 kcal/mol. [ABSTRACT FROM AUTHOR]

A three dimensional potential energy surface for the F + H2 → HF + H reaction has been computed by the spin unrestricted coupled cluster method with singles, doubles, triples, and perturbative quadruples [UCCSDT(2)Q] using the augmented correlation-consistent polarised valence quadruple zeta basis set for the fluorine atom and the correlation-consistent polarised valence quadruple zeta basis set for the hydrogen atom. All the calculations are based on the restricted open-shell Hartree-Fock orbitals, together with the frozen core approximations, and the UCCSD(T)/complete basis set (CBS) correction term was included. The global potential energy surface was calculated by fitting the sampled ab initio points without any scaling factor for the correlation energy part using a neutral network function method. Extensive dynamics calculations have been carried out on the potential energy surface. The reaction rate constants, integral cross sections, product rotational states distribution, and forward and backward scattering as a function of collision energy of the F + HD → HF + D, F + HD → DF + H, and F + H2 reaction, were calculated by the time-independent quantum dynamics scattering theory using the new surface. The satisfactory agreement with the reported experimental observations previously demonstrates the accuracy of the new potential energy surface. [ABSTRACT FROM AUTHOR]

In arid areas, almost all the water resources in the basin come from mountainous areas. Nvertheless, the process of water storage and runoff generation has not been fully understood in different vegetation zones in mountainous areas, which is the main obstacle blocking human cognition of hydrological processes and water resources assessment. In current study, the spatiotemporal dynamics of stable isotopes were monitored in different water bodies and soil water storage in different vegetation zones in the upper reaches of Xiying River. The results show that: (1) The water storage capacity of surface soil was weak in vegetation zones, and soil water was mainly saved up in the middle and lower soil layers. (2) Surface and subsurface runoff could form in the Alpine Meadow and Coniferous Forest during the rainy season and the snow melting season. The lower elevation vegetation zones of Mountain Grassland and Deciduous forest evaporate strongly and infiltrate partially into the middle and bottom layers of the soil to store or recharge groundwater, rarely generating surface runoff. This work would provide a scientific foundation for reasonably explaining the mechanism of water production in mountainous areas of arid regions, and provide a reference for formulating management policies suitable for sustainable development of water resources and improving the ability to cope with climate change in arid areas. [ABSTRACT FROM AUTHOR]

We have established a stable water isotope monitoring network in the Shiyang River Basin in China'arid northwest. The basin is characterized by low precipitation, high evaporation and dense population. It is the basin with the most significant ecological pressure and the greatest water resources shortage in China. The monitoring station covers the upper, middle and lower reaches of the river basin, with six observation systems: river source area, oasis area, reservoir canal system area, oasis farmland area, ecological restoration area, and salinized area. All data in the data set are differentiated by water body types (precipitation, river water, lake water, groundwater, soil water, plant water). The data set is updated annually to gradually improve each observation system and increase data from observation points. So far, the data have been obtained for five consecutive years. The data set includes stable isotope data, meteorological data and hydrological data in the Shiyang River Basin. The data set can analyze the relationship between different water bodies and water circulation in the Shiyang River Basin. This observation network's construction provides us with stable water isotopes data and hydrometeorological data, and we can use theae data for hydrological and meteorological related scientific research. It can also provide a scientific basis for water resources utilization, water conservancy project construction, and ecological environment restoration decision-making in China's arid areas. The data that support the findings of this study are openly available in Zhu (2021) at "Data sets of Stable water isotope monitoring network of different water bodies in Shiyang River Basin, a typical arid river in China (Supplemental Edition)", Mendeley Data, V1, doi: 10.17632/w5rpxwf99g.1. [ABSTRACT FROM AUTHOR]

This work is concerned with the calculation of state-to-state S-matrix elements for four-atom reactions using a recently proposed method based on the quantum transition-state theory. In this approach, the S-matrix elements are computed from the thermal flux cross-correlation functions ob-tained in both the reactant and product arrangement channels. Since transition-state wave packets are propagated with only single arrangement channels, the bases/grids required are significantly smaller than those needed in state-to-state approaches based on a single set of scattering coordinates. Fur-thermore, the propagation of multiple transition-state wave packets can be carried out in parallel. This method is demonstrated for the H2/D2 + OH → H/D + H2O/HOD reactions (J = 0) and the reaction probabilities are in excellent agreement with benchmark results. [ABSTRACT FROM AUTHOR]

The kinetics and dynamics of several O + O2 isotope exchange reactions have been investigated on a recently determined accurate global O3 potential energy surface using a time-dependent wave packet method. The agreement between calculated and measured rate coefficients is significantly improved over previous work. More importantly, the experimentally observed negative temperature dependence of the rate coefficients is for the first time rigorously reproduced theoretically. This negative temperature dependence can be attributed to the absence in the new potential energy surface of a submerged "reef" structure, which was present in all previous potential energy surfaces. In addition, contributions of rotational excited states of the diatomic reactant further accentuate the negative temperature dependence. [ABSTRACT FROM AUTHOR]

A recently proposed transition-state wave packet method [R. Welsch, F. Huarte-Larrañaga, and U. Manthe, J. Chem. Phys. 136, 064117 (2012)] provides an efficient and intuitive framework to study reactive quantum scattering at the state-to-state level. It propagates a few transition-state wave packets, defined by the eigenfunctions of the low-rank thermal flux operator located near the transition state, into the asymptotic regions of the reactant and product arrangement channels separately using the corresponding Jacobi coordinates. The entire S-matrix can then be assembled from the corresponding flux-flux cross-correlation functions for all arrangement channels. Since the transition-state wave packets can be defined in a relatively small region, its transformation into either the reactant or product Jacobi coordinates is accurate and efficient. Furthermore, the grid/basis for the propagation, including the maximum helicity quantum number K, is much smaller than that required in conventional wave packet treatments of state-to-state reactive scattering. This approach is implemented for atom-diatom reactions using a time-dependent wave packet method and applied to the H + D2 reaction with all partial waves. Excellent agreement with benchmark integral and differential cross sections is achieved. [ABSTRACT FROM AUTHOR]

A framework for quantum state-to-state integral and differential cross sections of triatomic reactive scattering using the Multi-Configuration Time-Dependent Hartree (MCTDH) method is introduced, where a modified version of the Heidelberg MCTDH package is applied. Parity of the system is adopted using only non-negative helicity quantum numbers, which reduces the basis set size of the single particle functions in angular degree of freedom almost by half. The initial wave packet is constructed in the space-fixed frame, which can accurately account for the centrifugal potential. By using the reactant-coordinate-based method, the product state-resolved information can be accurately extracted. Test calculations are presented for the H + H2 reactive scattering. This work demonstrates the capability of the MCTDH method for extracting accurate state-to-state integral and differential cross sections. As an efficient scheme for high-dimensional problems, the MCTDH method may be promising for the study of product state-resolved cross sections for polyatomic reactive systems. [ABSTRACT FROM AUTHOR]

The photodissociation dynamics of H2O in its first absorption band is investigated on an accurate potential energy surface based on a large number of high-level ab initio points. Several ro-vibrational states of the parent molecule are considered. Different from most previous theoretical studies, the spin-orbit and ?-doublet populations of the open-shell OH fragment are reported from full-dimensional wave packet calculations. The populations of the two spin-orbit manifolds are in most cases close to the statistical limit, but the ?-doublet is dominated by the A ? component, thanks largely to the fast in-plane dissociation of H2O( A1A'' ). Comparisons with experimental data and a Franck-Condon model are generally very good, although some discrepancies exist. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the expression of miR-223-3p in a rat model of myocardial infarction and the effects of miR-223-3p on cardiomyocytes. Forty rats were randomly divided into mock surgical, model (acute myocardial infarction (AMI) group (AMIG)), AMI+miR-223-3p adenovirus (intervention group (IG)), and AMI+scramble-NC (negative control group (NCG)) groups. Cardiac function was assessed by small animal echocardiography. Reverse transcription polymerase chain reaction was used to quantify the expression of miR-223-3p. The expression levels of miR-233-3p and SOX6 mRNA in the blank control group (BCG) and mock surgical group (MSG) were lower than those in the AMIG, IG, and NCG (P < 0.05), while the cardiac function indices of the BCG and MSG were higher than those of the AMIG, IG, and NCG (P < 0.05). The expression levels of miR-233-3p and SOX6 mRNA in the AMIG and NCG were significantly higher than those in the IG, while their cardiac function indices were significantly lower than those in the IG. Our findings indicate that the silencing of miR-223-3p effectively improves the cardiac function of rats, and the overexpression of miR-223-3p promotes the apoptosis of cardiomyocytes. Thus, miR-223-3p may be a new therapeutic target for AMI. [ABSTRACT FROM AUTHOR]

The authors report a detailed quantum mechanical study of the state-to-state dynamics of the O+OH(vi=0, ji=0)→H+O2(vf,jf) reaction on an accurate HO2(X2A″) potential energy surface. The scattering dynamics was treated using a reactant coordinate based Chebyshev real wavepacket method with full Coriolis coupling. A total of 84 partial waves were calculated in order to achieve convergence up to the collision energy of 0.17 eV. The differential cross section is near forward-backward symmetric, consistent with the complex-forming mechanism. The O2 product was found to have a monotonically decaying vibrational distribution and highly excited and inverted rotational distributions, also consistent with the formation of the HO2 intermediate. These quantum mechanical results were compared with those obtained in earlier quasiclassical trajectory and statistical studies and it is shown that the statistical theory gives a reasonably good description of the product state distributions despite its inability to predict the total reaction cross section. [ABSTRACT FROM AUTHOR]

The dispersive lines observed in time-resolved femtosecond stimulated Raman spectroscopy (FSRS), using a pair of 809 nm, 3 ps Raman pump, and 840–960 nm ultrashort probe pulse, for the first 500 fs photoisomerization dynamics in the excited state of bacteriorhodopsin, BR* (S1), created by a prior 500 nm, 35 fs actinic pump pulse, have previously been attributed to Raman initiated by nonlinear emission (RINE). We used four-wave mixing energy level diagrams to describe the FSRS process, which include RINE as a subset, and a 29-mode harmonic oscillator model for BR568 in the calculations. Our calculations showed that FSRS of BR* effectively occurs from the ground vibrational state of each of the observed 800–1800 cm-1 modes of S1. The lifetime on S1 determines the linewidth and decay of the dispersive lines, and is estimated to be ∼600 fs, comparable to the stimulated emission decay time. The FSRS dipole couplings are from the ground vibrational state of S1 to high energy vibrational states on BR (S0), and we place a fast decay lifetime of ∼100 fs on S0 which can be attributed to the correlation function from the many unobserved low frequency modes. The FSRS dispersive lines are shown to be due to the inverse Raman scattering term with |0><1| vibrational coherence on the S1 surface, and are not due to RINE with vibrational coherence on the S0 surface. Our calculations show that the RINE process gives rise to broad featureless spectra. [ABSTRACT FROM AUTHOR]

The S-matrix for a scattering system provides the most detailed information about the dynamics. In this work, we discuss the calculation of S-matrix elements for the A+BC→AB+C, AC+B type reaction. Two methods for extracting S-matrix elements from a single wave packet in reactant Jacobi coordinates are reviewed and compared. Both methods are capable of extracting the state-to-state attributes for both product channels from a single wave packet propagation. It is shown through the examples of H+HD, Cl+H2, and H+HCl reactions that such reactant coordinate based methods are easy to implement, numerically efficient, and accurate. Additional efficiency can be gained by the use of a L-shaped grid with two-dimensional fast Fourier transform. [ABSTRACT FROM AUTHOR]

We describe a time-dependent wavepacket based method for the calculation of the state-to-state cross sections for the Cl+H2 reaction including all couplings arising from the nonzero spin and electronic orbital angular momenta of the Cl atom. Reactant-product decoupling allows us to use a physically correct basis in both the reactant and the product arrangements. Our calculated results agree well with the experimental results of Yang and co-workers. We also describe a model with two coupled potential energy surfaces, which includes the spin-orbit coupling, which is responsible for the largest non-Born–Oppenheimer effects in the Cl+H2 reaction but neglects the off-diagonal electronically diabatic coupling and all Coriolis couplings due to the electronic spin and orbital angular momenta. The comparison of the results of the full six-state and two-state models with an electronically adiabatic (one-state) description reveals that the latter describes well the reaction out of the ground spin-orbit state, while the two-state model, which is computationally much faster than the full six-state model, describes well the reaction from both the ground and excited spin-orbit states. [ABSTRACT FROM AUTHOR]

Quantum state-to-state dynamics for the NH+H/D→H+NH/ND exchange reaction is reported on an accurate ab initio potential energy surface. The differential cross section is dominated by scattering into both the forward and backward directions, while the product shows strong rotational excitation. The calculated rate constant for the NH+D reaction is in excellent agreement with experiment. The applicability of a quantum statistical model is tested against exact state-to-state quantum results. Due to strong nonreactive scattering, the statistical model significantly overestimates the integral cross section. However, it is shown that the product state distribution and differential cross sections are reasonably well reproduced by the statistical model because the reactive scattering is dominated by a complex-forming mechanism. [ABSTRACT FROM AUTHOR]

A detailed comparison of the time-dependent wave packet method using the split operator propagator and recently introduced Chebyshev real wave packet approach for calculating reactive scattering processes is reported. As examples, the state-to-state differential cross sections of the H+H′D(v0=0,j0=1)→H′D+H/H′H+D reaction, the state-to-state reaction probabilities of the 16O+35O2 (v0=0,j0=0)→17O+16O18O/18O+16O17O reaction, the H+O2→O+HO reaction, and the F+HD→HF+D reaction are calculated, using an efficient reactant-coordinate-based method on an L-shape grid which allows the extraction of the state-to-state information of the two product channels simultaneously. These four reactions have quite different dynamic characteristics and thus provide a comprehensive picture of the relative advantages of these two propagation methods for describing reactive scattering dynamics. The results indicate that the Chebyshev real wave packet method is typically more accurate, particularly for reactions dominated by long-lived resonances. However, the split operator approach is often more cost effective, making it a method of choice for fast reactions. In addition, our results demonstrate accuracy of the reactant-coordinate-based method for extracting state-to-state information. [ABSTRACT FROM AUTHOR]

We present a complete perturbation theory of stimulated Raman scattering (SRS), which includes the new experimental technique of femtosecond stimulated Raman scattering (FSRS), where a picosecond Raman pump pulse and a femtosecond probe pulse simultaneously act on a stationary or nonstationary vibrational state. It is shown that eight terms in perturbation theory are required to account for SRS, with observation along the probe pulse direction, and they can be grouped into four nonlinear processes which are labeled as stimulated Raman scattering or inverse Raman scattering (IRS): SRS(I), SRS(II), IRS(I), and IRS(II). Previous FSRS theories have used only the SRS(I) process or only the “resonance Raman scattering” term in SRS(I). Each process can be represented by an overlap between a wave packet in the initial electronic state and a wave packet in the excited Raman electronic state. Calculations were performed with Gaussian Raman pump and probe pulses on displaced harmonic potentials to illustrate various features of FSRS, such as high time and frequency resolution; Raman gain for the Stokes line, Raman loss for the anti-Stokes line, and absence of the Rayleigh line in off-resonance FSRS from a stationary or decaying v=0 state; dispersive line shapes in resonance FSRS; and the possibility of observing vibrational wave packet motion with off-resonance FSRS. [ABSTRACT FROM AUTHOR]

The quantum theory for stimulated Raman spectroscopy from a moving wave packet using the third-order density matrix and polarization is derived. The theory applies, in particular, to the new technique of femtosecond broadband stimulated Raman spectroscopy (FSRS). In the general case, a femtosecond actinic pump pulse first prepares a moving wave packet on an excited state surface which is then interrogated with a coupled pair of picosecond Raman pump pulse and a femtosecond Raman probe pulse and the Raman gain in the direction of the probe pulse is measured. It is shown that the third-order polarization in the time domain, whose Fourier transform governs the Raman gain, is given simply by the overlap of a first-order wave packet created by the Raman pump on the upper electronic state with a second-order wave packet on the initial electronic state that is created by the coupling of the Raman pump and probe fields acting on the molecule. Calculations are performed on model potentials to illustrate and interpret the FSRS spectra. [ABSTRACT FROM AUTHOR]

The absorption spectra of the C(2A2)←X(2B1) transition of the OBrO molecule are calculated using three-dimensional time-dependent wave-packet method in Radau coordinates for a total angular momentum J=0. The wave packet is propagated using the split operator technique associated with fast Fourier transform. Employing the basis functions obtained by one-dimensional Fourier grid Hamiltonian method, the initial wave packet is calculated directly on the three-dimensional Fourier grid. The numerical model is characterized by simplicity and efficiency. The ab initio potential surfaces for the C(2A2) and X(2B1) states are used in the calculation. The calculated absorption spectra of the C(2A2)←X(2B1) transition of OBrO molecule agree well with the experimental results. [ABSTRACT FROM AUTHOR]

Besides cumulative temperature and precipitation, the phase synchronization of temperature and precipitation also helps to regulate vegetation distribution and productivity across global lands. However, the phase synchronization has been rarely considered in previous studies related to climate and biogeography due to a lack of a robust and quantitative approach. In this study, we proposed a synchronization index of temperature and precipitation (SI-TaP) and then investigated its global spatial distribution, interannual fluctuation, and long-term trend derived from a global 60-year dataset of meteorological forcings. Further investigation was conducted to understand the relationship between SI-TaP and the annually summed Normalized Difference Vegetation Index (NDVI), which could be a proxy of terrestrial vegetation productivity. Results show differences in both spatial patterns and temporal variations between SI-TaP and air temperature and precipitation, but SI-TaP may help to explain the distribution and productivity of terrestrial vegetation. About 60 % of regions where annually summed NDVI is greater than half of its maximum value overlap regions where SI-TaP is greater than half of its maximum value. By using SI-TaP to explain vegetation productivity along with temperature and precipitation, the maximum increase in the coefficient of determination is 0.66 across global lands. Results from this study suggest that the proposed SI-TaP index is helpful to better understand climate change and its relation to the biota. Dataset available at http://www.dx.doi.org/10.11922/sciencedb.642 or http://www.sciencedb.cn/dataSet/handle/642. [ABSTRACT FROM AUTHOR]

A series of transition metal oxide-modified HBEA (MxOy/HBEA) zeolite catalysts were prepared by the wetness impregnation method, and investigated for the alkylation of toluene with tert-butanol to synthesise 4-tert-butyltoluene (4-TBT). Their physico-chemical properties were characterised by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller and NH3 temperature-programmed desorption methods. MxOy /HBEA zeolite showed higher para-selectivity than parent HBEA due to its improved structural and acidic properties. Though the toluene conversion of MxOy /HBEA catalyst decreased, the 4-TBT selectivity increased significantly at 190 °C after 4 h. The narrowed pores after loading the MxOy prompted an increase in selectivity for 4-TBT by increasing the shape selectivity. In addition, the decrease in strong acid sites increased selectivity for 4-TBT by suppressing further isomerisation of the 4-TBT formed on acid sites. Among all the modified HBEA zeolites, Fe2O3/HBEA exhibited the best catalytic activity and para-selectivity. The factors affecting the reaction over Fe2O3/HBEA have also been investigated extensively. [ABSTRACT FROM AUTHOR]

As a well-known angiogenic factor in different histology and pathological conditions, the pro-progressive role of vasohibin2 (VASH2) has been reported in various types of tumors. However, its role in drug resistance of breast cancer has not been reported so far. The present study demonstrated that MCF-7 cells with increased expression of VASH2 demonstrate stronger adriamycin (ADM) resistance compared with MDA-MB-231 cells with decreased expression of VASH2. Overexpression of VASH2 in MDA-MB-231 cells increased ADM resistance and silencing VASH2 in MCF-7 cells inhibited ADM resistance. Furthermore, in newly established ADM resistant cell lines, VASH2 was significantly upregulated. These results revealed the promotive role of VASH2 in the ADM resistance of breast cancer cells. In addition, overexpression of VASH2 in MDA-MB-231 cells significantly upregulated ATP-binding cassette sub-family G member 2 (ABCG2), however silencing VASH2 in MCF-7 cells inhibited ABCG2 significantly. Silencing ABCG2 abrogated increase of ADM resistance induced by VASH2 overexpression in MDA-MB-231 cells. This proved that VASH2 induced ADM resistance through promoting expression of ABCG2, at least in part. Further study regarding the underlying molecular mechanism demonstrated that VASH2 promoted ABCG2 via the protein kinase B (AKT) signaling pathway. Overall, VASH2 may promote drug resistance of breast cancer cells through regulating ABCG2 via the AKT signaling pathway. This suggests a novel therapeutic target to inhibit drug resistance in breast cancer, for a more efficient therapeutic outcome. [ABSTRACT FROM AUTHOR]

In this paper, a Reliability-Sensitivity BasedDesign Optimization (RSBDO) methodology for the design of the ceramic matrix composites (CMCs) components has been proposed. A practical and efficient method for reliability analysis and sensitivity analysis of complex components with arbitrary distribution parameters are investigated by using the perturbation method, the respond surface method, the Edgeworth series and the sensitivity analysis approach. The RSBDO methodology is then established by incorporating sensitivity calculation model into RBDO methodology. Finally, the proposed RSBDO methodology is applied to the design of the CMCs components. By comparing with Monte Carlo simulation, the numerical results demonstrate that the proposed methodology provides an accurate, convergent and computationally efficient method for reliability-analysis based finite element modeling engineering practice. [ABSTRACT FROM AUTHOR]

As one of the first-established negative feedback regulators of angiogenesis, mesenchymal vasohibin-1 (VASH1) serves important roles in the progression and prognosis of various types of tumor. However, the clinical implications of VASH1 in esophageal carcinoma (EC) cells have not been reported and the direct effects of VASH1 on EC cells remain unknown. In the present study, the expression of VASH1 in EC cells was observed using immunohistochemistry and western blotting; a χ² test was used to analyze the correlation of VASH1 with clinical parameters, and it was observed that VASH1 was negatively-correlated with tumor size (r=-0.399; P<0.01) and invasion depth (r=-0.318; P<0.01). Survival analysis demonstrated that VASH1 was positively-correlated with increased overall survival (P=0.039) and disease free survival (P=0.012). The direct effects of VASH1 on EC cells were analyzed by altering VASH1 expression, and it was observed that downregulation of VASH1 increased proliferation, clone formation and the migratory ability of EC9706 cells, whereas upregulation of VASH1 inhibited proliferation, clone formation and the migratory ability of EC1 cells. The results of the present study demonstrated that VASH1 in EC cells was negatively-correlated with progression and poor prognosis of patients with EC. VASH1 was able to directly inhibit the growth and migration of EC cells. [ABSTRACT FROM AUTHOR]

Recent studies have demonstrated that deregulated microRNA (miRNA/miR) expression has a profound impact on biological and pathological processes; abnormal miR-1469 expression was detected in several human malignancies. In the present study, the clinicopathological and prognostic significance of miR-1469 was assessed in 129 patients with esophageal squamous cell cancer (ESCC) who successfully underwent esophagectomy and esophagogastrostomy. Low miR-1469 expression was identified to be significantly associated with tumor invasion depth (P=0.026), lymph node metastasis status (P<0.001) and pathological tumor stage (P<0.001). Survival analysis demonstrated that patients with low miR-1469 expression had significantly poorer disease-free survival (DFS) (18.2 vs. 43.2%; P=0.004) and overall survival (29.1 vs. 47.3%; P=0.029) 5 years following surgery compared with patients with high miR-1469 expression. Univariate survival analysis demonstrated that low miR-1469 expression significantly predicted unfavorable 5-year DFS among patients with N1-3 disease (7.1 vs. 31.8%; P=0.043). The results from the present study indicate that miR-1469 expression could be used in the clinic to predict ESCC progression and prognosis. This will aid in the identification of high-risk patients with ESCC that require more aggressive therapeutic interventions. [ABSTRACT FROM AUTHOR]

Most permanent magnet (PM) machines are driven by inverters with pulse-width modulation (PWM) voltages. The currents contain high-frequency (HF) components which are inversely proportional to machine inductance. The HF PWM ripple currents can be used to detect a turn fault that gives rise to changes in inductance. The features of these HF components under turn fault conditions are analyzed. A bandpass filter is designed to extract the selected sideband components, and their root-mean-square (rms) values are measured. The rms values in all phases are compared. It is shown that the rms ripple current ratios between two adjacent phases provide a very good means of detecting turn fault with high signal-to-noise ratio. The detection method can identify the faulted phase and tolerate inherent imbalance of the machine, and is hardly affected by transient states. The method is assessed by simulations and experiments on a five-phase PM machine. [ABSTRACT FROM PUBLISHER]

To analyse the permeability anisotropy of the Paleogene strata in the Zhanhua sag of the Bohai Bay Basin, 10 groups of 40 sandstone and mudstone samples were selected to conduct four experiments with pressures. The results indicate that horizontal permeability of porous sandstone and mudstone is greater than the vertical permeability at normal atmospheric pressure. Then the permeability anisotropy of sandstone and mudstone is mainly related to its arrangement of particles. The horizontal and vertical permeability of sandstone and mudstone decrease with increased pressure and increase with reduced pressure, but the increased rate of horizontal permeability is greater than that of vertical when the pressure is reduced, and both of them cannot be restored to the same values by increasing the pressure to the previous values. The permeability of sandstone and mudstone are greatly increasing after fracturing, and the mudstone increases more than that of sandstone. When increase or decrease the pressures to the samples with fractures, the permeability parallel to the fractures is greater than that perpendicular to the fractures. However, the permeability changes more dramatically with the pressure perpendicular to the fractures, indicating that fracture permeability is more sensitive to the pressures. In all, the permeability anisotropy of the Paleogene strata in Zhanhua Sag is related to its arrangement of particles, pressures, fractures, and the direction of the pressure and fractures. [ABSTRACT FROM AUTHOR]