Environmental profiles, hazard identification, and toxicological hallmarks of emerging tire rubber-related contaminants 6PPD and 6PPD-quinone

N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) is commonly used in rubber compounds as antioxidants to protect against degradation from heat, oxygen, and ozone exposure. This practice extends the lifespan of rubber products, including tires, by preventing cracking, aging, and deterioration. However, the environmental consequences of waste generated during rubber product use, particularly the formation of 6PPD-quinone (6PPD-Q) through the reaction of 6PPD with ozone, have raised significant concerns due to their detrimental effects on ecosystems. Extensive research has revealed the widespread occurrence of 6PPD and its derivate 6PPD-Q in various environmental compartments, including air, water, and soil. The emerging substance of 6PPD-Q has been shown to pose acute mortality and long-term hazards to aquatic and terrestrial organisms at concentrations below environmentally relevant levels. Studies have demonstrated toxic effects of 6PPD-Q on a range of organisms, including zebrafish, nematodes, and mammals. These effects include neurobehavioral changes, reproductive dysfunction, and digestive damage through various exposure pathways. Mechanistic insights suggest that mitochondrial stress, DNA adduct formation, and disruption of lipid metabolism contribute to the toxicity induced by 6PPD-Q. Recent findings of 6PPD-Q in human samples, such as blood, urine, and cerebrospinal fluid, underscore the importance of further research on the public health and toxicological implications of these compounds. The distribution, fate, biological effects, and underlying mechanisms of 6PPD-Q in the environment highlight the urgent need for additional research to understand and address the environmental and health impacts of these compounds.

Disentangled Dynamic Deviation Transformer Networks for Multivariate Time Series Anomaly Detection

Graph neural networks have been widely used by multivariate time series-based anomaly detection algorithms to model the dependencies of system sensors. Previous studies have focused on learning the fixed dependency patterns between sensors. However, they ignore that the inter-sensor and temporal dependencies of time series are highly nonlinear and dynamic, leading to inevitable false alarms. In this paper, we propose a novel disentangled dynamic deviation transformer network (D3TN) for anomaly detection of multivariate time series, which jointly exploits multiscale dynamic inter-sensor dependencies and long-term temporal dependencies to improve the accuracy of multivariate time series prediction. Specifically, to disentangle the multiscale graph convolution, we design a novel disentangled multiscale aggregation scheme to better represent the hidden dependencies between sensors to learn fixed inter-sensor dependencies based on static topology. To capture dynamic inter-sensor dependencies determined by real-time monitoring situations and unexpected anomalies, we introduce a self-attention mechanism to model dynamic directed interactions in various potential subspaces influenced by various factors. In addition, complex temporal correlations across multiple time steps are simulated by processing the time series in parallel. Experiments on three real datasets show that the proposed D3TN significantly outperforms the state-of-the-art methods.

Comparative Analysis of the Pre- and Post-Medication Effects of Antipsychotic Agents on the Blood-Based Oxidative Stress Biomarkers in Patients with Schizophrenia: A Meta-Analysis

OBJECTIVE

Studies have shown that oxidative stress (OS) is related to the pathophysiology of schizophrenia (SCZ), but whether antipsychotics can induce OS has not been investigated well. Moreover, antipsychotics have differential effects on the OS level modulation, i.e., different types of antipsychotics have different effects on the cellular antioxidants or pro-oxidants.

METHODS

We followed the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines and investigated the OS indicators including both enzymatic and nonenzymatic markers, such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), malondialdehyde (MDA), glutathione (GSH), vitamin C, etc., of SCZ patients at baseline and follow-up of mono-medication.

RESULTS

Twenty studies met the inclusion criteria, with a total of 1162 patients enrolled at baseline, and 1105 patients completed the follow-up. OS markers were changed after a period of antipsychotic treatment in SCZ patients. The GPx activity and MDA level decreased in the whole blood (P<0.05), also the serum MDA level decreased (P<0.05). For the first-episode SCZ patients, the activity of GPx and the level of MDA decreased, while the level of vitamin C increased (all P<0.05). The levels of MDA in patients receiving atypical antipsychotics decreased (P<0.05), while the level of GSH in patients with typical antipsychotics decreased (P=0.05).

CONCLUSION

Antipsychotic medication may cause changes in the levels of OS markers in different blood samples of SCZ patients. However, the available studies might not be sufficient to reveal the underlying facts accurately due to the poor quality of experimental designs in the published literature.

[Diagnostic value of combined application of GATA3, SOX10 and p16 in triple negative breast carcinomas]

Objective: To investigate the expression of GATA3, SOX10, and p16 in triple-negative breast cancer (TNBC) and analyze their significance and correlation with clinicopathology. Methods: The expressions of GATA3, SOX10 and p16 in 53 cases of TNBC and 50 cases of non-TNBC were detected by immunohistochemical staining. Results: GATA3 and SOX10 were positive in 58.5%(31/53) and 75.5%(40/53) of TNBC, respectively. The expression of SOX10 was significantly higher than that in non-TNBC (P<0.05). SOX10 was positive in 17 of the 22 cases that lacked GATA3 expression (77.3%). The expression of p16 was significantly higher in the TNBC, and the co-expression with SOX10 was significantly increased (P<0.05). The sensitivity, specificity, and AUC under the ROC curve of SOX10 were higher than those of GATA3. The sensitivity of SOX10 was higher than that of p16, but the specificity was lower than that of p16. The AUC of SOX10 was higher than that of p16. AUC of combined detection of GATA3 and SOX10, SOX10 and p16 were higher than that of each antibody alone (P<0.05). The expression of GATA3, SOX10, and p16 had no significant correlation with age, tumor size, and lymph node metastasis. The expression of SOX10 and p16 in grade 3 and basal-like TNBC increased significantly, and their co-expression increased. Conclusions: The expressions of SOX10 and p16 in TNBC are significantly increased. SOX10 is a reliable marker for the diagnosis of TNBC and a supplement to GATA3. Whether p16 is a marker related to the prognosis of TNBC remains to be further studied.

An integrated remote sensing and model approach for assessing forest carbon fluxes in China

Forest plays an important role in reducing pressure on the natural environment, weaking the influence of greenhouse effects, and sequestrating atmospheric carbon dioxide. So far, due to the lack of complete understanding of forest ecosystem processes and the limitations on the scope of application of evaluation methods, there are still great uncertainties in the researches on carbon fluxes of forest ecosystems in China at the national level. In this study, an individual tree species FORCCHN model, which could flexibly use the inventory data as the initial field (more accurately) or use the remote sensing information to inverse initial field was applied. The dynamics of key carbon cycle fluxes (net primary productivity (NPP) and net ecosystem productivity (NEP)) and carbon sequestration of forest ecosystems in China from 1982 to 2019 were simulated based on remote sensing data and FORCCHN model. The results showed that forest ecosystems in China had great carbon sequestration potential over the past 39 years. From 1982 to 2019, the NPP of Chinese forests presented a fluctuated increase. Total NPP from 2011 to 2019 ranged from 0.91 PgC·a^-1 to 1.14 PgC·a^-1. Annual average NEP of forest ecosystems in China from 2011 to 2019 was 0.199 PgC·a^-1 (1Pg = 10¹⁵ g). Influenced by climate, soil and vegetation, carbon sequestration potential in Chinese forest ecosystems presented obvious regional differences in space. The spatial distribution of NEP gradually increased from Northwest to Southeast China. From 2011 to 2019, forests in Yunnan Province had the strongest carbon storage capacity (72.79 TgC·a^-1, 1Tg = 10¹² g), followed by forests in Guangxi (18.49 TgC·a^-1) and forests in Guangdong (10.01 TgC·a^-1). Our results not only address concerns about carbon sequestration but also reflect the importance of Chinese forest resources in the development of the national economy and society.

[Induction of peripheral blood mononuclear cells to hepatocyte-like cells and preliminary study of cell response to injury under the effect of acetaminophen]

Objective: To establish a method for the induction of peripheral blood mononuclear cells to hepatocyte-like cells, and preliminarily investigate cell response to injury under the effect of acetaminophen (APAP). Methods: The surface marker CD45 of peripheral blood mononuclear cells wase detected cells by using flow cytometry and immunofluorescence methods. The cellular morphology of induced hepatocyte-like cells was observed under an inverted microscope. Real-time fluorescent quantitative PCR (RT-PCR) was used to detect the expression level of hepatocyte-specific genes, such as cytochrome (CY) P1A2, CYP3A4, CYP2C9, albumin (ALB), alpha-fetoprotein (AFP), and hepatocyte nuclear factor (HNF)4α mRNA. Immunofluorescence method was used to detect intracellular hepatocyte markers AFP, HNF4α, and ALB expression at the protein level. Biochemical analyzer was used to detect hepatocyte-specific secretory functions of AFP, ALB, and urea. Luciferase chemiluminescence method was used to detect the activity of key drug metabolizing enzyme CYP3A4. Colorimetric assay was used to detect the effect of the drug acetaminophen on hepatocyte-like cells, and alanine aminotransferase (ALT) was used as an indicator of liver cell injury. The statistical differences between the data were compared with t-test and rank-sum test. Results: The positive expression rate of CD45 cell surface markers isolated from peripheral blood mononuclear cells was about 98%, and hepatocyte-like cell morphology changes appeared on 15th day of induction. Compared with isolated mononuclear cells, CYP1A2, CYP3A4, CYP2C9, ALB, AFP and HNF4α mRNA was markedly elevated. The expression level of AFP, ALB and HNF4α protein were equally increased, and the secretory function of AFP, ALB and urea were enhanced. Compared with primary hepatocytes, CYP1A2, CYP2C9, AFP, HNF4α mRNA, and CYP3A4 mRNA did not decrease. The expression levels of AFP, ALB, and HNF4α proteins in the cells did not decrease, and the secretory function of AFP, ALB, and urea did not decrease. In addition, the CYP3A4 enzyme activity produced by hepatocyte-like cells was similar to that of primary hepatocytes. Compared with hepatocyte-like cells incubated without APAP, hepatocyte-like cells incubated with APAP had higher ALT level. Under the effect of APAP, the ALT level of hepatocyte-like cells was higher than isolated mononuclear cells. Conclusion: Peripheral blood mononuclear cells can be induced into hepatocyte-like cells with partial characteristics of hepatocytes, including the activity of CYP3A4, a key enzyme of hepatocyte drug metabolism. Additionally, preliminarily ALT secretory features reflect the hepatocytes injury under the effect of acetaminophen.

Single-Atom Ru Implanted on Co3 O4 Nanosheets as Efficient Dual-Catalyst for Li-CO2 Batteries

Li-CO2 battery has attracted extensive attention and research due to its super high theoretical energy density and its ability to fix greenhouse gas CO2 . However, the slow reaction kinetics during discharge/charge seriously limits its development. Hence, a simple cation exchange strategy is developed to introduce Ru atoms onto a Co3 O4 nanosheet array grown on carbon cloth (SA Ru-Co3 O4 /CC) to prepare a single atom site catalyst (SASC) and successfully used in Li-CO2 battery. Li-CO2 batteries based on SA Ru-Co3 O4 /CC cathode exhibit enhanced electrochemical performances including low overpotential, ultra high capacity, and long cycle life. Density functional theory calculations reveal that single atom Ru as the driving force center can significantly enhance the intrinsic affinity for key intermediates, thus enhancing the reaction kinetics of CO2 reduction reaction in Li-CO2 batteries, and ultimately optimizing the growth pathway of discharge products. In addition, the Bader charge analysis indicates that Ru atoms as electron-deficient centers can enhance the catalytic activity of SA Ru-Co3 O4 /CC cathode for the CO2 evolution reaction. It is believed that this work has important implications for the development of new SASCs and the design of efficient catalyst for Li-CO2 batteries.

Molecular dynamics simulation of metallic Al-Ce liquids using a neural network machine learning interatomic potential

Al-rich Al-Ce alloys have the possibility of replacing heavier steel and cast irons for use in high-temperature applications. Knowledge about the structures and properties of Al-Ce alloys at the liquid state is vital for optimizing the manufacture process to produce desired alloys. However, reliable molecular dynamics simulation of Al-Ce alloy systems remains a great challenge due to the lack of accurate Al-Ce interatomic potential. Here, an artificial neural network (ANN) deep machine learning (ML) method is used to develop a reliable interatomic potential for Al-Ce alloys. Ab initio molecular dynamics simulation data on the Al-Ce liquid with a small unit cell (∼200 atoms) and on the known Al-Ce crystalline compounds are collected to train the interatomic potential using ANN-ML. The obtained ANN-ML model reproduces well the energies, forces, and atomic structure of the Al₉₀Ce₁₀ liquid and crystalline phases of Al-Ce compounds in comparison with the ab initio results. The developed ANN-ML potential is applied in molecular dynamics simulations to study the structures and properties of the metallic Al₉₀Ce₁₀ liquid, which would provide useful insight into the guiding experimental process to produce desired Al-Ce alloys.

Fine particulate matter exposure exacerbated nasal mucosal damage in allergic rhinitis mice via NLRP3 mediated pyroptosis

BACKGROUND

The incidence of nasal allergy/allergic rhinitis (AR) is rising worldwide, which has become a serious public health problem. Epidemiological studies point that exposure to environmental PM2.5 is closely linked to AR aggravation, however, the exactly mechanism is not clear. This study was performed to reveal molecular mechanisms of PM2.5 -induced AR deterioration.

METHODS

Morphology and element analysis of PM2.5 was examined by scanning electron microscopy (SEM) and Energy Dispersive Spectrometer (EDS). A total of 24 female C57BL/6 mice were divided into three groups (control group, AR group, and PM2.5 + AR group, each group contains 8 mice). Mice from AR group and PM2.5 + AR group were intraperitoneally injected with OVA suspension (0.004% OVA+3% aluminum hydroxide) on days 1, 7, and 14. 0.2 mL /kg B.W. for sensitization; then the same mice were intranasal instilled with 5% OVA solution daily for 7 days to established AR mice model (each nostril for 10 μl, day 15-21). The mice were intranasal instilled PBS (control group and AR group, each nostril for 10 μl) or PM2.5 (AR + PM2.5 group, 4.0 mg/kg b.w., each nostril for 10 μl) at the same way from day 23-29. The nasal symptoms were evaluated after the last instillation of PM2.5. Pathological changes and ultrastructure of nasal mucosa were observed by HE staining and SEM. Goblet cells hyperplasia was performed by Periodic acid-Schiff (PAS) staining. NLRP3, Caspase-1, GSDMD and IL-1β protein expression were assessed by immunohistochemical (IHC) staining.

RESULTS

Exposure to PM2.5 aggravated rhinitis symptom, promoted the secretion of serum IgE level and destroyed ultrastructural of nasal mucosa. Interestingly, NLRP3, Caspase-1 GSDMD and IL-1β protein expression were obviously elevated. NLRP3 /Capase-1/ GSDMD meditated cell pyroptosis participated in the process of AR exacerbation. However, macrophage is not the main effector cell.

CONCLUSION

PM2.5 exposure induces aggravation of allergic rhinitis, which is related to NLRP3 inflammasome meditated caspase-1 activation and cell pyroptosis in nasal mucosal.

Fine particulate matter-induced lung inflammation is mediated by pyroptosis in mice

BACKGROUND

Exposure to ambient air-borne fine particulate matter (PM_2.5) increases respiratory morbidity and mortality. The mechanisms underlying PM_2.5-induced adverse effects remain unclear. This study aimed to uncover the molecular mechanisms of PM_2.5-induced lung toxicity using a mouse model.

METHODS

Scanning electron microscopy and inductively coupled plasma mass spectrometry were used to examine and analyze PM_2.5 morphology and element compositions, respectively. Twenty four male mice were randomly divided into three groups: control (PBS), PM_2.5 (4.0 mg/kg b.w.), and PM_2.5 + Z-YVAD-FMK. In the latter group, the pan-caspase inhibitor (Z-YVAD-FMK) was intraperitoneally injected into mice at a dose of 12.5 mg/kg body weight prior to intratracheal instillation of PM_2.5 (4.0 mg/kg b.w.) every other day for a total of 3 times (n = 8 in each group). Bronchoalveolar lavage fluids (BALFs) were collected 24 h after the last instillation of PM_2.5. Levels of total proteins (TP), lactate dehydrogenase (LDH), IL-1β and IL-18 were analyzed for biomarkers of cell injury and inflammation. Additionally, histological alterations of lung tissues were assessed by hematoxylin-eosin staining. mRNA and protein expression of Caspase1, NLRP3 and GSDMD were examined by real-time fluorescent quantitative PCR and immunohistochemical staining.

RESULTS

Exposure to PM_2.5 increased levels of TP, LDH, IL-1β, IL-18 and inflammatory cell counts in lung. The mRNA and protein expression of Caspase1, NLRP3 and GSDMD were increased. Inhibition of the NALRP3/Caspase-1 signaling pathway ameliorated PM_2.5-induced lung injury and inflammation, partially through suppressing pyroptosis in lung.

CONCLUSION

PM_2.5 exposure induces lung injury and inflammation, which is mediated by the NALRP3/Caspase-1 signaling pathway.

Localized electronic and vibrational states in amorphous diamond

Amorphous diamond structures are generated by quenching high-density high-temperature liquid carbon using tight-binding molecular-dynamics simulations. We show that the generated amorphous diamond structures are predominated by strong tetrahedral bonds with the sp3 bonding fraction as high as 97%, thus exhibit an ultra-high incompressibility and a wide band gap close to those of crystalline diamond. A small amount of sp2 bonding defects in the amorphous sample contributes to localized electronic states in the band gap while large local strain gives rise to localization of vibrational modes at both high and low frequency regimes.

Influencing Factors of Hospital-Acquired Pneumonia Infection in the Middle-Aged and Elderly Patients With Schizophrenia

Introduction: Pneumonia is an important cause of death in patients with schizophrenia. It is critical to understand the risk factors of hospital-acquired pneumonia (HAP) and determine prevention strategies to reduce HAP. The aim of this study is to elucidate the risk factors for HAP in the middle-aged and elderly hospitalized patients with schizophrenia. Methods: We retrospectively reviewed the medical records of 2,617 the middle-aged and elderly patients (age ≥ 50) with schizophrenia who were admitted for the first time to a large-scale psychiatric hospital between 2016 and 2020. The factors related to the incidence of HAP in patients were analyzed, including personal characteristics, antipsychotics, and non-antipsychotics. Results: The HAP infection rate of hospitalized the middle-aged and elderly patients with schizophrenia was 7.8%. Chi-square analyses showed that older age, male, and ≥60 days of hospitalization were risk factors for HAP infection (χ² = 94.272, p < 0.001; χ² = 22.110, p < 0.001; χ² = 8.402, p = 0.004). Multivariate logistic regression showed that quetiapine, clozapine, and olanzapine significantly increased the incidence of HAP (OR = 1.56, 95% CI = 1.05-2.32, p = 0.029; OR = 1.81, 95% CI = 1.26-2.60, p = 0.001; OR = 1.68, 95% CI = 1.16-2.42, p = 0.006). Antipsychotic drugs combined with aceglutamide had an effect on HAP (OR = 2.19, 95% CI = 1.38-3.47, p = 0.001). Conclusion: The high HAP infection rate in hospitalized the middle-aged and elderly patients with schizophrenia may be related to the increase of age and the use of antipsychotic drugs. The types and dosages of antipsychotic drugs should be minimized while paying attention to the mental symptoms of patients.

Structure of a two-dimensional superparamagnetic system in a quadratic trap

Ground-state structures of a two-dimensional (2D) system composed of superparamagnetic charged particles are investigated by means of molecular dynamics simulation. The charged particles trapped in a quadratic potential interact with each other via the repulsive, attractive, and magnetic dipole-dipole forces. Simulations are performed within two regimes: a one-component system and a two-component system where the charged particles have the identical charge-to-mass ratio. The effects of magnetic dipole-dipole interaction, mixing ratio of the two species and confinement frequency on the ground-state structures are discussed. It is found that as the strength of the magnetic dipole increases, the charged particles tend to self-organize into chainlike structures. The two species particles exhibit different structural features, depending on the competition of electrostatic repulsive interaction, magnetic dipole-dipole interaction and confinement force. The potential lanes are observed through analyzing the global potential of the magnetic particles, which guide the unmagnetic particles aligning themselves in the direction of the potential lanes.

Stable C2N/h-BN van der Waals heterostructure: flexibly tunable electronic and optic properties

Monolayer C2N has been successfully synthesized. To explore the enhancement of its stability and the expansion of its potential applications in electronics and optoelectronics, a vertical van der Waals heterostructure is constructed by C2N monolayer integrated withh-BN monolayer. The first-principles calculations based on the density functional theory show that this structure possesses a type-II band alignment with a smaller direct band gap and lager band offsets, suggesting that photo-generated electron-hole pairs can be well spatially separated, and thus an excellent photoelectric and photovoltaic material can be obtained. Also shown is that the electronic properties of such a heterostructure can be effectively regulated by a vertical strain and external electric field. For example, under compressive strain or forward electric field, its band gap can be significantly reduced to enhance light-excitation electron transition further, meanwhile the feature of direct band-gap and large band offsets is always well-preserved. Furthermore, it is found that the intrinsic heterostructure holds a wide optic adsorption range and large adsorption coefficient, and the applied compressive strain or a positive electric field can lead to a wide and high main absorption peak across the near-infrared, visible light, and ultraviolet region, implying that a tuned heterostructure has more promising applications in optoelectronics.

Tailored Plasmons in Pentacene/Graphene Heterostructures with Interlayer Electron Transfer

van der Waals (vdW) heterostructures, which are produced by the precise assemblies of varieties of two-dimensional (2D) materials, have demonstrated many novel properties and functionalities. Here we report a nanoplasmonic study of vdW heterostructures that were produced by depositing ordered molecular layers of pentacene on top of graphene. We find through nanoinfrared (IR) imaging that surface plasmons formed due to the collective oscillations of Dirac Fermions in graphene are highly sensitive to the adjacent pentacene layers. In particular, the plasmon wavelength declines systematically but nonlinearly with increasing pentacene thickness. Further analysis and density functional theory (DFT) calculations indicate that the observed peculiar thickness dependence is mainly due to the tunneling-type electron transfer from pentacene to graphene. Our work unveils a new method for tailoring graphene plasmons and deepens our understanding of the intriguing nano-optical phenomena due to interlayer couplings in novel vdW heterostructures.

Cells´ Flow and Immune Cell Priming under alternating g-forces in Parabolic Flight

Gravitational stress in general and microgravity (µg) in particular are regarded as major stress factors responsible for immune system dysfunction in space. To assess the effects of alternating µg and hypergravity (hyper-g) on immune cells, the attachment of peripheral blood mononuclear cells (PBMCs) to adhesion molecules under flow conditions and the antigen-induced immune activation in whole blood were investigated in parabolic flight (PF). In contrast to hyper-g (1.8 g) and control conditions (1 g), flow and rolling speed of PBMCs were moderately accelerated during µg-periods which were accompanied by a clear reduction in rolling rate. Whole blood analyses revealed a "primed" state of monocytes after PF with potentiated antigen-induced pro-inflammatory cytokine responses. At the same time, concentrations of anti-inflammatory cytokines were increased and monocytes displayed a surface molecule pattern that indicated immunosuppression. The results suggest an immunologic counterbalance to avoid disproportionate immune responses. Understanding the interrelation of immune system impairing and enhancing effects under different gravitational conditions may support the design of countermeasures to mitigate immune deficiencies in space.

Observation of η-Al41Sm5 reveals motif-aware structural evolution in Al-Sm alloys

Using an effective genetic algorithm, we uncover the structure of a metastable Al41Sm5 phase that supplements its family sharing similar short-range orders. The phase evolves upon heating an amorphous Al-9.7 at.% Sm ribbon, produced by melt-spinning. The dynamical phase selection is discussed with respect to the structural connections between the short-range packing motifs in the amorphous precursor and those observed in the selected phases. The phase elucidated here is one of several newly discovered large-unit-cell phases found to form during devitrification from the glass in this binary system, further illustrating the power and efficiency of our approach, the important role of structural hierarchy in phase selection, and the richness of the metastable phase landscape accessible from the glassy structure.

Effects of Si solute on the glass formation and atomic structure of Pd liquid

Molecular dynamics simulations were performed to study the effects of Si solute on the glass formation and crystallization of Pd liquid. Pure Pd samples prepared by a quenching process with a cooling rate of 10¹³ K s^-1 can be in an amorphous state but the structural analysis indicates there is nearly no glass-forming motif in the sample. However, doping a small amount of Si (Si concentration ~4%) the sample can be vitrified at a cooling rate of 10¹² K s^-1. The glass-forming motifs such as Pd-centered Z13, Si-centered Z9-like and mixed-ICO-cube clusters with five-fold local symmetry are found to be the dominant short-range orders in the glassy samples. With the increasing of the Si-doping concentration, these glass-forming motifs tend to aggregate and connect with each other forming a network structure. Our calculated results revealed that Si solutes in liquid Pd can significantly enhance the glass-forming ability.

Novel superconducting structures of BH2 under high pressure

The crystal structures of boron hydrides in a pressure range of 50-400 GPa were studied using the genetic algorithm (GA) method combined with first-principles density functional theory calculations. BH4 and BH5 are predicted to be thermodynamically unstable. Two new BH2 structures with Cmcm and C2/c space group symmetries, respectively, were predicted, in which the B atoms tend to form two-dimensional sheets. The calculated band structures showed that in the pressure range of 50-150 GPa, the Cmcm-BH2 phase has very small gaps, while the C2/c-BH2 phase at 200-400 GPa is metallic. The superconductivity of the C2/c-BH2 structure was also investigated, and electron-phonon coupling calculations revealed that the estimated Tc values of C2/c-BH2 are about 28.18-37.31 K at 250 GPa.

[Seasonal distribution of patient hospitalization due to asthma exacerbation in 7 geographic areas in China]

Objective: To understand the seasonal distribution of patient hospitalization due to asthma exacerbation in 7 geographic areas in China. Methods: This was a retrospective study which involved patients hospitalized for asthma exacerbation in 29 hospitals throughout 7 geographic areas in the mainland of China (northeast, north, central, east, south, northwest and southwest). The numbers of asthmatic patients and total inpatients of the respiratory department of each hospital were recorded. The monthly ratio of asthmatic patients to the total inpatients in every area was calculated and compared. Results: During the study period, 6 480 patients were admitted for asthma exacerbation, accounting for 3.14% of all the 206 135 patients admitted to the respiratory departments in the 29 hospitals. The ratio of asthmatic patients to total inpatients in the northeast area (5.61%) was highest, and the ratio in east area was lowest (1.97%). Statistical analysis showed that the difference among different areas was significant (P<0.000 1). In most areas, both the number and proportion of hospitalized asthmatic patients peaked in spring (February-April) and autumn (September-October). In the northeast area, east area and south area, the peaks in spring were more obvious, while in the north area and southwest area, the peaks in autumn were more obvious. In the northwest area the peaks occurred in winter (December-January) and summer (June-August), respectively. The differences in hospitalization due to asthma among different months were significant in the northeast, north, and southwest areas (P<0.005). Conclusion: The number of patients hospitalized for asthma exacerbation fluctuated with season in different areas in China. In most areas, more asthmatic patients were admitted to hospitals in spring and autumn.

[Seasonal characteristics of patients hospitalized for asthma exacerbation in China]

Objective: To study the seasonal characteristics of patients hospitalized for asthma exacerbation in China. Methods: This was a retrospective study which involved patients hospitalized for asthma exacerbation in 29 hospitals throughout mainland China during 2013-2014. The number of patients hospitalized for asthma exacerbation in each hospital was calculated, as well as the ratio of asthmatic patients to all the hospitalized patients. The analysis by month was conducted. The number and ratio of asthmatic patients in the northern and southern cities were calculated respectively. Results: During the study period, there were 6 480 patients hospitalized for asthma exacerbation, accounting for 3.14% (6 480/206 135) of all the hospitalized patients of the respiratory department in 29 hospitals. The analysis by month showed that the ratio of patients hospitalized for asthma exacerbation was highest in March (3.49%), then declined from April to June, then rose again from July, reaching a second peak at September (3.28%), and then declined again from October to December. The ratio of asthmatic patients in every month was higher in northern cities than in southern cities. Conclusions: The ratio of patients hospitalized for asthma exacerbation in China fluctuates with the changes of seasons, and March and September are the two peak months. Northern cities have a higher ratio of asthmatic patients than southern cities.

[Warning symptoms of asthma attack and asthma self-management: a national asthma control survey from China]

Objective: To investigate warning symptoms of asthma attack and evaluate asthma self-management status of asthma patients in urban China. Methods: A multi-center, cross-sectional, questionnaire-based survey was carried out from 30 general hospitals dispersed in 30 provinces of mainland China (except for Tibet) during Oct 2015 to May 2016. Information of frequency and warning symptoms of asthma attack, the time from warning symptoms to asthma attack, the impact of asthma attack and asthma self-management were collected from asthma patients of outpatient department. Results: Altogether 3 875 asthmatic outpatients were recruited. 78.1% (3 026/3 875) of the patients reported restriction of exercise and daily activities during asthma exacerbation. 82.5% (3 160/3 829) of the patients had warning symptoms before asthma attack, the most common warning symptoms were cough, chest tightness and shortness of breath. The median time from warning symptoms to asthma attack was 2 h, the mean time was 90 h. Only 4.4% (167/3 829) of the patients had definite confidence to control asthma when symptoms deteriorated. 76.7% (2 937/3 828) of the patients used medications to control asthma when asthma symptoms deteriorated. Medication choice: inhaled corticosteroid (ICS) + formoterol 45.8% (1 776/3 875), short-acting beta-agonist (SABA) 23.9% (927/3 875). Conclusions: Most asthma patients have warning symptoms before asthma attack, the most common symptoms are cough, chest tightness and shortness of breath. The proportion of patients conducting effective asthma self-management remains low.

[The level of asthma control in China from a national asthma control survey]

Objective: To assess the overall asthma control level in urban China. Methods: A multi-center, cross-sectional, questionnaire-based survey was carried out in 30 provinces in China (except Tibet). Asthmatic outpatients who met the inclusion criteria were recruited consecutively from 30 sub-centers from October 2015 to May 2016. Data of demographic characteristics, asthma control, asthma management, asthma exacerbations and self-management, and disease perception were collected by face-to-face interviews. Results: Totally 3 875 asthmatic outpatients were recruited. Asthma control level was assessed according to GINA 2015. The prevalence of asthma control was 28.5%(1 099/3 854). Among 10 cities, which were also involved in the asthma control survey in 2008, the level of asthma control improved from 28.7% in 2008 to 39.2%(533/1 361) in 2016. The rate of hospitalizations due to asthma exacerbations was 26.4%(1 017/3 858) and the rate of emergency visits was 22.4%(864/3 858). Among adult patients, 18.4%(568/3 092) of them had been absent from work while 63.6%(63/99) adolescent patients had been absent from school because of asthma attacks in the previous year. Conclusion: Although the level of asthma control in China is still far from ideal at present, the status has been improved in some cities. Poorly controlled asthma resulted in increase of hospitalizations, emergency department visits and work/school absences.

[A multi-center retrospective study of clinical characteristics and hospitalization costs of patients hospitalized for asthma exacerbation in China during 2013-2014]

Objective: To study the characteristics of patients hospitalized for asthma exacerbation in 29 teaching hospitals in China and to evaluate the hospitalization costs of these patients. Methods: This was a retrospective study and involved patients hospitalized for asthma exacerbation in 29 hospitals throughout China during 2013-2014. Information about the demographic features, conditions before the admission, the outcome, the complications, and the costs was collected using the pre-designed case report form. The influencing factors of the hospitalization costs were analyzed. Results: 3 240 asthmatic patients (1 369 males and 1 871 females) were included and data were analyzed. There were 41.5% (1 346/3 240) patients who had a history of previous hospitalization or emergency department visits during the last year. Only 28.0% (907/3 240) patients had used asthma-controlling medications regularly before the admission. Seventy-three(2.3%) patients were admitted to ICU and used mechanical ventilation. Mortality among these patients hospitalized for asthma exacerbation was 0.25% (8/3 240). The median hospitalization costs was 9 045(6 431, 13 035) RMB. The costs of medications, examinations and treatment accounted for 52.1%, 27.6%, and 9.6% respectively. The costs of asthma medications accounted for only 22.7% of the total medication costs, while the costs of antibiotics accounted for 44.0%. The patients who were admitted to ICU, used mechanical ventilation, complicated with pneumonia, or had a history of hospitalization or emergency department visits during the last year due to asthma exacerbations tended to cost more. Conclusion: In this study, we demonstrated that only a minority of the patients had used asthma controllers regularly before the admissions with exacerbations. The in-hospital mortality of asthma patients in this study was much lower than that reported in other countries. The average cost of hospitalization was much higher than the yearly cost of maintenance therapy. Medication was the predominant component of the total hospitalization costs, and the costs of antibiotics made up the major part of the total medication costs.

[A retrospective study of the treatment of patients hospitalized for asthma exacerbation in China]

Objective: To study the treatment of patients hospitalized for asthma exacerbation in China. Methods: This was a retrospective study and involved patients hospitalized for asthma exacerbation in 29 hospitals throughout China during Jan 2013 to Dec 2014. Information of the demographic features, the severity of the exacerbation, the medicine prescribed during the hospitalization and the use of mechanical ventilation were collected and analyzed. Results: During the study period, there were 3 240 patients hospitalized for asthma exacerbation, and 1 369(42.3%) of them were males 1 871(57.7%)were females. Patients of mild, moderate, severe, and life-threatening exacerbation counted for 41.7%, 37.8%, 19.2% and 1.0%, respectively of the total patients. Of all the patients, 72.6% used bronchodilators by nebulizer, 70.8% used inhaled corticosteroids by nebulizer, 60.5% used intravenous corticosteroids, 17.3% used oral corticosteroids, and 80.5% used antibiotics. The percentages of patients using systemic corticosteroids and antibiotics were higher in patients with more severe exacerbation. In patients with mild exacerbation, there were 74.9% and 52.2% who used antibiotics and systemic corticosteroids, respectively. A total of 73 patients (2.3%) used mechanical ventilation, and 62 of them used noninvasive ventilation, 16 used invasive ventilation, and 5 used both. Conclusions: Nebulizer therapy has been accepted as the main administration route of medicine in the treatment of asthma exacerbation. A large amount of patients used antibiotics and systemic corticosteroids during hospitalization, indicating there may be some overuse of these medicines.

[Evaluation of asthma disease perception from China national asthma control survey]

Objective: In order to evaluate disease perception of asthma patients in urban China and provide evidence for further specific patient education. Methods: A multi-center, cross-sectional, questionnaire-based survey was carried out in 30 general hospitals dispersed in 30 provinces of mainland China (except for Tibet) during Oct 2015 to May 2016. Information of disease perception [Question 1: the disease nature of asthma; Question 2: medication choice of first-line in chronic asthma; Question 3: the occasion of using short-acting aerosols of receptor agonists; Question 4: perception of asthma treatment goal; Question 5: reason for not using peak flow meter (PFM)] were collected from asthma patients of outpatient department. These results were compared with the same type of survey results from 2007-2008. Results: Altogether 3 875 asthmatic outpatients were recruited. 69.0% (2 660/3 857) of the patients had right perception on the disease nature of asthma, 60.2% (2 321/3 857) of the patients considered inhaled corticosteroids (ICS)/inhaled corticosteroids plus long-acting beta2-agonists (ICS+ LABA) as daily-used first-line medication for chronic asthma. 85.7% (3 277/3 823) of the patients had right perception on the condition of using short-acting beta2-agonists (SABA). 75.4% (2 761/3 661) of the patients had right perception on asthma treatment goal. Only 10.1% (388/3 837) of the patients used PFM. Of the reasons for not using PFM, 65.2% (2 518/3 860) of the patients chose doctors never introduced. Among the 10 cities, which were also involved in the asthma control survey in 2007-2008, 71.1% (968/1 361) of the patients had right perception on the disease nature of asthma, 61.6% (839/1 362) of the patients considered ICS/ICS+ LABA as daily-used first-line medication for chronic asthma. 88.7% (1 207/1 361) of the patients had right perception on the condition of using SABA. 74.5% (1 013/1 360) of the patients had right perception on asthma treatment goal. 17.9% (244/1 360) of the patients used PFM. Of the reasons for not using PFM, 76.2% (931/1 221) of the patients chose doctors never introduced. Compared to the survey conducted in 2007-2008, the perception on disease nature and medication choice as daily-used first-line medication for chronic asthma significantly improved, the perception on occasion of using SABA and asthma treatment goal was comparable, while the rate of PFM usage showed no significant improvement. In reasons of not using PFM, doctors never introduced ranked the first. Conclusions: Compared to the similar survey conducted in 2007-2008, the overall status of disease perception of asthma patients has been improved in urban China, while the rate of PFM usage showed no significant improvement. Asthma education on asthma and asthma self-management should be further pushed forward.

[A retrospective study of the mortality and death-related risk factors of patients hospitalized for asthma exacerbation in Chinese urban areas]

Objective: To study the mortality and death-related risk factors of patients hospitalized for asthma exacerbation in Chinese urban areas. Methods: A retrospective study was carried out in 29 hospitals of 29 provinces throughout mainland China. Patients hospitalized for asthma exacerbation during 2013-2014 in each hospital were included. For each patient, information about demography, admission time, comorbidities, severity of diseases, intense care unit (ICU) admission, use of mechanical ventilation and the outcome was obtained. The mortality of patients hospitalized for asthma exacerbation was calculated, and the basic information and causes of death of the patients who died were summarized. The death-related risk factors and numbers of comorbidities were compared between the patients who survived and those who died during hospitalization. Results: A total of 3 240 patients (median age 57.0) were included and among them 8 patients (median age 68.5) died. The mortality of patients hospitalized for asthma exacerbation was 0.25%. All the patients who died were admitted during the winter and spring. One patient died of acute myocardial infarction, one of cardiac shock, one of tension pneumothorax, one of sudden death, one of respiratory failure and three of unknown causes. The average number of comorbidities of patients who died was 1.10, larger than that of patients who survived (0.83) (P>0.05). More patients had diabetes, coronary artery diseases and hypertension as comorbidities in the patients who died (2/8) than those who survived[7.6% (246/3 232), 7.6% (246/3 232), 22.6% (731/3 232), respectively](all P>0.05). Conclusions: The in-hospital mortality of patients hospitalized for asthma exacerbation of China in this study is low. The patients who died are much older, and with more comorbidities, and a higher percentage of comorbidities such as diabetes, coronary artery diseases, and hypertension.

Fundamental Link between β Relaxation, Excess Wings, and Cage-Breaking in Metallic Glasses

In glassy materials, the Johari-Goldstein secondary (β) relaxation is crucial to many properties as it is directly related to local atomic motions. However, a long-standing puzzle remains elusive: why some glasses exhibit β relaxations as pronounced peaks while others present as unobvious excess wings? Using microsecond atomistic simulation of two model metallic glasses (MGs), we demonstrate that such a difference is associated with the number of string-like collective atomic jumps. Relative to that of excess wings, we find that MGs having pronounced β relaxations contain larger numbers of such jumps. Structurally, they are promoted by the higher tendency of cage-breaking events of their neighbors. Our results provide atomistic insights for different signatures of the β relaxation that could be helpful for understanding the low-temperature dynamics and properties of MGs.

[A multi-center study for the association between the perception and control of disease among asthmatic patients in Chinese urban areas]

Objective: To investigate the current perception of disease among asthmatic patients in Chinese urban areas, and to address its association with asthma control. Methods: This was a nationwide, multi-center, cross-sectional study covering 30 third-level, grade A hospitals in 30 provinces, municipalities and autonomous regions (not including Tibet) across Chinese mainland. The survey was carried out from October 2015 to May 2016. Asthmatic outpatients were selected to receive face-to-face questionnaire survey on asthma control including Asthma Control Test (ACT) score, classification of asthma control level[according to the Global Initiative for Asthma (GINA) 2015 classification system, as assessed by the physician completing the survey], perception of asthma (including question 1: nature of asthma as a disease; question 2: selection of first-line therapeutic agents to be regularly used daily for asthma; question 3: appropriate timing of the use of short-acting aerosols of β(2) receptor agonists; and question 4: therapeutic goals for asthma). Results: A total of 3 875 asthmatic outpatients were included; among them, 69.0% (2 660/3 857) were aware that asthma is "an airway inflammatory disorder resulting from the combined effects of heredity and environment" ; 60.2% (2 321/3 857) considered "inhaled glucocorticoids or their compound preparations" to be the first-line therapeutic agents to be regularly used daily for patients with persistent chronic asthma; 85.7% (3 277/3 823) considered it appropriate to use short-acting aerosols of β(2) receptor agonists "as needed in the event of disease aggravation or acute exacerbation" ; and 75.4% (2 761/3 661) were aware that asthma "can be adequately or completely controlled in the long term" . The ACT score[20 (16, 23) vs 19 (16, 22) points; Z=-3.928, P<0.001]and asthma control rate (29.92% vs 25.31%; χ(2)=8.616, P=0.003) were significantly higher, and the rate of uncontrolled asthma (19.92% vs 23.48%; χ(2)=6.267, P=0.012) was significantly lower among the 2 660 (69.0%) patients correctly answering question 1 than among the 1 197 (31.0%) patients giving incorrect answer. The ACT score[21 (17, 23) vs 19 (15, 22) points; Z=-9.190, P<0.001] and asthma control rate (32.66% vs 22.20%; χ(2)=49.614, P<0.001) were significantly higher, and the rate of uncontrolled asthma (18.40% vs 25.00%; χ(2)=24.267, P<0.001) was significantly lower among the 2 321 (60.2%) patient correctly answering question 2 than among the 1 536 (39.8%) patients giving incorrect answer. Conclusions: Compared to previous surveys, there has been improved perception of disease among asthmatic patients in Chinese urban areas. Correct perception of disease is favorable for improving asthma control level.

Crystal genes in a marginal glass-forming system of Ni50Zr50

The marginal glass-forming ability (GFA) of a binary Ni-Zr system is an issue to be explained considering numerous bulk metallic glasses (BMGs) found in a Cu-Zr system. Using molecular dynamics, the structures and dynamics of Ni₅₀Zr₅₀ metallic liquid and glass are investigated at the atomistic level. To achieve a well-relaxed glassy sample, a sub-T_g annealing method is applied and the final sample is closer to the experiments than the models prepared by continuous cooling. With the state-of-the-art structural analysis tools such as cluster alignment and pair-wise alignment methods, two glass-forming motifs with some mixed traits of a metastable B2 crystalline phase and a crystalline Ni-centered B33 motif are found to be dominant in the undercooled liquid and glass samples. A new chemical order characterization on each short-range order (SRO) structure is accomplished based on the cluster alignment method. The significant amount of the crystalline motif and the few icosahedra in the glassy sample deteriorate the GFA.

Fe-Si networks in Na2FeSiO4 cathode materials

Using a combination of adaptive genetic algorithm search, motif-network search scheme and first-principles calculations, we have systematically studied the low-energy crystal structures of Na2FeSiO4. We show that the low-energy crystal structures with different space group symmetries can be classified into several families based on the topologies of their Fe-Si networks. In addition to the diamond-like network which is shared by most of the low-energy structures, another three robust Fe-Si networks are also found to be stable during the charge/discharge process. The electrochemical properties of representative structures from these four different Fe-Si networks in Na2FeSiO4 and Li2FeSiO4 are investigated and found to be strongly correlated with the Fe-Si network topologies. Our studies provide a new route to characterize the crystal structures of Na2FeSiO4 and Li2FeSiO4 and offer useful guidance for the design of promising cathodes for Na/Li ion batteries.

Novel penta-graphene nanotubes: strain-induced structural and semiconductor-metal transitions

Research into novel one-dimensional (1D) materials and associated structural transitions is of significant scientific interest. It is widely accepted that a 1D system with a short-range interaction cannot have 1D phase transition at finite temperature. Herein, we propose a series of new stable carbon nanotubes by rolling up penta-graphene sheets, which exhibit fascinating well-defined 1D phase transitions triggered by axial strain. Our first-principles calculations show that such penta-graphene nanotubes (PGNTs) are dynamically stable by phonon calculations, but transform from a tri-layer structure to a highly defective single-walled nanotube at low temperature in molecular dynamics simulations. We show that moderate compressive strains can drive structural transitions of (4,4), (5,5), and (6,6) PGNTs, during which the distances of neighboring carbon dimers in the inner shell have a sudden drop, corresponding to dimer-dimer nonbonding to bonding transitions. After such transition, the tubes become much more thermally stable and undergo semiconductor-metal transitions under increasing strain. The band gaps of PGNTs are not sensitive to chirality whereas they can be tuned effectively from visible to short-wavelength infrared by appropriate strain, making them appealing materials for flexible nano-optoelectronics. These findings provide useful insight into unusual phase transitions in low-dimensional systems.

[Identification of Y-chromosomal Genetic Types for the Soldier's Remains from Huaihai Campaign]

OBJECTIVES

To identify the Y-chromosomal genetic types for the soldier's remains from Huaihai Campaign, and to offer a clue for search of their paternal relatives.

METHODS

DNA of the remains were extracted by the ancient DNA extraction method. Yfiler kit was used for the multiplex amplification of 17 Y-STR loci. The haplogroups of the samples were speculated. Detailed genotyping of the selected Y-SNP was performed based on the latest Y-chromosome phylogenetic tree. Haplotype-sharing analysis was done based on the data of Y-SNP and Y-STR, the closest modern individual information to the genetic relationship of remains was gained.

RESULTS

A total of 8 Y-STR haplotypes were observed on 17 Y-STR loci of 8 male individuals. Furthermore, 6 Y-SNP haplogroups were identified, which were O2a1-M95+, O1a1-P203+, O3*-M122+/M234-, D1-M15+, C3*-ST and R1a1-M17+.

CONCLUSIONS

Identification of Y-chromosomal genetic types for the soldier's remains from Huaihai Campaign shows a reference value on inferring the geographical origins of old materials.

[Chinese expert consensus for non-antiinfective effects and clinical use of macrolides]

Important/potential value of macrolides has been proved in the management of chronic respiratory diseases by increasing basic and clinical trials.Through three face-to-face discussions, 10 experts examined important data and drafted this consensus related to macrolides: (1) mechanism of non-antiinfective effects; (2) clinical use in chronic respiratory diseases; (3) cautions of long-term use.The mechanism out of non-antiinfective effects includes anti-inflammatory effect, modifying airway secretion, immune-regulation related to antibacterial effect, corticoid saving effect and anti-viral effect.The efficacy of long-term use of low-dose macrolides is definitely confirmed in diffuse panbronchiolitis, chronic rhinosinusitis. It is considerably used in bronchiectasia, cystic fibrosis, severe asthma and chronic obstructive pulmonary disease. Further studies should be conducted in cryptogenic organizing pneumonia and respiratory viral infection. It should be paid attention to its possible adverse effects (including drug interactions, cardiac toxicity, ototoxicity and disturbance of intestinal flora) and drug resistance in long-term use.A Chinese consensus for non-antiinfective effects and clinical use of macrolides is developed for the first time, which aims to expand their rational use and the further research.

High-pressure structures of yttrium hydrides

In this work, the crystal structures of YH₃ and YH₄ at high pressure (100-250 GPa) have been explored using a genetic algorithm combined with first-principles calculations. New structures of YH₃ with space group symmetries of P21/m and I4/mmm were predicted. The electronic structures and the phonon dispersion properties of various YH₃ and YH₄ structures at different temperatures and pressures were investigated. Among YH₃ phases, the P21/m structure of YH₃ was found to have a relatively high superconducting transformation temperature T _c of 19 K at 120 GPa, which is reduced to 9 K at 200 GPa. Other YH₃ structures have much lower T _cs. Compared with YH₃, the T _c of the YH₄ compound is much higher, i.e. 94 K at 120 GPa and 55 K at 200 GPa.

Identifying the heterogeneity of COPD by V/P SPECT: a new tool for improving the diagnosis of parenchymal defects and grading the severity of small airways disease

Introduction

Airway obstruction and possible concomitant pulmonary diseases in COPD cannot be identified conventionally with any single diagnostic tool. We aimed to diagnose and grade COPD severity and identify pulmonary comorbidities associated with COPD with ventilation/perfusion single-photon emission computed tomography (V/P SPECT) using Technegas as the functional ventilation imaging agent.

Methods

94 COPD patients (aged 43–86 years, Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages I–IV) were examined with V/P SPECT and spirometry. Ventilation and perfusion defects were analyzed blindly according to the European guidelines. Penetration grade of Technegas in V SPECT measured the degree of obstructive small airways disease. Total preserved lung function and penetration grade of Technegas in V SPECT were assessed by V/P SPECT and compared to GOLD stages and spirometry.

Results

Signs of small airway obstruction in the ventilation SPECT images were found in 92 patients. Emphysema was identified in 81 patients. Two patients had no signs of COPD, but both of them had a pulmonary embolism, and in one of them we also suspected a lung tumor. The penetration grade of Technegas in V SPECT and total preserved lung function correlated significantly to GOLD stages (r=0.63 and −0.60, respectively, P<0.0001). V/P SPECT identified pulmonary embolism in 30 patients (32%). A pattern typical for heart failure was present in 26 patients (28%). Parenchymal changes typical for pneumonia or lung tumor were present in several cases.

Conclusion

V/P SPECT, using Technegas as the functional ventilation imaging agent, is a new tool to diagnose COPD and to grade its severity. Additionally, it revealed heterogeneity of COPD caused by pulmonary comorbidities. The characteristics of these comorbidities suggest their significant impact in clarifying symptoms, and also their influence on the prognosis.

Effects of Oxygen Impurities on Glass-Formation Ability in Zr2Cu Alloy

Using ab initio molecular dynamics simulations, we show that oxygen (O) impurities have a noticeable influence on the glass-formation ability (GFA) in Zr2Cu alloy. Cu-centered icosahedral clusters and Zr-centered Kasper polyhedra are the dominate short-range orders in undercooled Zr2Cu liquid which are most likely to be responsible for the glass formation in Zr2Cu systems. When O is introduced, a Zr octahedron is formed around the O impurity. Most of the Zr atoms in the octahedron also serve as the bridging atoms for cross-linked Kasper polyhedral network, resulting in an O-centered medium range order (MRO) structure. Meanwhile, Cu atoms are moved away from the first shell of O-centered octahedral clusters. With 1 at. % O impurities, the fractions of Zr-centered clusters are less affected, while the increase of ideal icosahedral order and decrease of distorted icosahedral order lead to a more stable atomic structure. This result suggests that a low concentration of O impurities would improve the GFA in Zr2Cu alloy. However, when ∼5 at. % O impurities are included, the ideal icosahedral clusters and Zr-centered Kasper polyhedra are seriously suppressed by the formation of O-centered MRO, which can lead to deterioration of GFA. Our analyses provide useful insight into glass formation behavior in O-doped metallic alloy systems.

[A three years longitudinal follow-up study of pulmonary function changes in patients with chronic obstructive pulmonary disease]

OBJECTIVE

To investigate the characteristics and the risk factors of pulmonary function in patients with chronic obstructive pulmonary disease (COPD) for a 3 year follow-up.

METHODS

Subjects diagnosed as COPD were followed up for 3 years in the Management Center of Chronic Respiratory Disease at XINQIAO Hospital from September 2009 to June 2012.This was a retrospective study. Parameters related to respiratory function mainly first second forced expiratory volume (FEV1), COPD assessment test (CAT), 6 minutes walking distance (6MWD) and acute exacerbation were recorded during follow-up.

RESULTS

Although the majority of patients were treated with drugs such as inhaled corticosteroid combined with long-term bronchial dilatation during the three years, FEV1 decreased progressively. The average annual decline of FEV1 was(31.80±61.99)ml, translating into a mean annual decline of(3.74±6.18)%. However, there were significant differences in changes of FEV1. Approximately, FEV1 in 78.3% (47/60) patients decreased, only 21.7%(13/60) patients kept stable FEV1. There was a correlation between decrease of FEV1, FEV1%predicted and the exacerbation (r=0.298, 0.361, 0.273; P<0.05). Logistic regression showed that the positive bronchodilator reversibility and the initial FEV1 were the independent factors associated with significant changes in FEV1 (respectively, OR=5.54, 95%CI 1.55-19.73; OR=8.28, 95%CI 1.42-48.32).

CONCLUSION

The changes of pulmonary function in patients with COPD are heterogeneous, although most patients are treated in a standard way. Nearly 80% patients still represent deterioration of pulmonary function. Decline of FEV1 is closely related to the initial pulmonary function and bronchodilator reversibility.

Tight-binding calculation studies of vacancy and adatom defects in graphene

Computational studies of complex defects in graphene usually need to deal with a larger number of atoms than the current first-principles methods can handle. Here, we show that a recently developed three-center tight-binding potential for carbon is very efficient for large scale atomistic simulations and can accurately describe the structures and energies of various defects in graphene. Using the three-center tight-binding potential, we have systematically studied the stable structures and formation energies of vacancy and embedded-atom defects of various sizes up to four vacancies and four embedded atoms in graphene. Our calculations reveal low-energy defect structures and provide a more comprehensive understanding of the structures and stability of defects in graphene.

Ab initio molecular dynamics simulations of short-range order in Zr₅₀Cu₄₅Al₅ and Cu₅₀Zr₄₅Al₅ metallic glasses

Comparative analysis between Zr-rich Zr50Cu45Al5 and Cu-rich Cu50Zr45Al5 metallic glasses (MGs) is extensively performed to locate the key structural motifs accounting for their difference of glass forming ability. Here we adopt ab initio molecular dynamics simulations to investigate the local atomic structures of Zr50Cu45Al5 and Cu50Zr45Al5 MGs. A high content of icosahedral-related (full and distorted) orders was found in both samples, while in the Zr-rich MG full icosahedrons ⟨0, 0, 12, 0⟩ is dominant, and in the Cu-rich one the distorted icosahedral orders, especially ⟨0, 2, 8, 2⟩ and ⟨0, 2, 8, 1⟩, are prominent. And the ⟨0, 2, 8, 2⟩ polyhedra in Cu50Zr45Al5 MG mainly originate from Al-centered clusters, while the ⟨0, 0, 12, 0⟩ in Zr50Cu45Al5 derives from both Cu-centered clusters and Al-centered clusters. These difference may be ascribed to the atomic size difference and chemical property between Cu and Zr atoms. The relatively large size of Zr and large negative heat of mixing between Zr and Al atoms, enhancing the packing density and stability of metallic glass system, may be responsible for the higher glass forming ability of Zr50Cu45Al5.

[Effect of blastocyst quality on the strategy of single blastocyst transfer in frozen-thawed cycles]

OBJECTIVE

To investigate the effect of blastocyst quality on the strategy of single blastocyst transfer in frozen-thawed cycles.

METHODS

A retrospective analysis was performed in Reproductive Medicine Center, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region on clinical data of single frozen-thawed blastocyst transfer cycles from January 2008 to December 2013. All cycles were divided into four groups (AA, AB/BA, BB, BC/CB) according to the blastocyst score, then the clinical outcomes were compared between groups. And on this basis, the clinical outcomes were further explored when the group of outcomes with single blastocyst transfer wasn't ideal, which would diverted to transfer two blastocyst.

RESULTS

In single frozen blastocyst transfer cycles, the clinical pregnancy rate of each group with the blastocyst scored AA, AB/BA, BB, BC/CB were 61.4% (470/765), 51.2% (330/645), 40.5% (407/1 005), 22.9% (60/262), live births rate in each group were 52.2% (399/765), 41.2% (266/645), 30.4% (306/1 005), 13.7% (36/262), and the abortion rate were 13.6% (64/470), 16.7% (55/330), 21.4% (87/407), 35.0%(21/60), separately. This showed that the clinical pregnancy rate and live births rate decreased significantly with the decline of blastocyst quality (P<0.01), but the abortion rate showed significant upward trend (P<0.01). When single blastocyst scored ≥BB grade transferred, an acceptable clinical pregnancy rate (>40%) and live births rate (>30%) could be obtained, however, the clinical pregnancy rate of 22.9% and live births rate of 13.7% could only be acquired when blastocyst scored BC/CB only transferred one embryo, which significant lower than those of each group scored ≥BB grade (P<0.01). So, after that, the blastocyst scored BC/CB were further divided into two groups (single blastocyst transferred versus two blastocyst transferred) to investigate, then the result showed that the clinical pregnancy rate [22.9% versus 38.5%(67/174),P<0.01] and live births rate [13.7% versus 30.5%(16/67),P<0.01] were significantly increased in the group of two blastocyst transferred compared with the group of one blastocyst transferred, and the abortion rate was also significantly decreased from 35.0% to 17.9% (12/67;P<0.05). So when two blastocyst scored BC/CB were transferred, the clinical outcomes were similar to the group of one blastocyst scored BB transferred (P>0.05).

CONCLUSIONS

Of single blastocyst transfer in frozen-thawed cycles, the clinical pregnancy rate and liver births rate showed significant upward trend, but the abortion rate showed significant downward trend, with the decline of blastocyst quality. When the blastocyst scored ≥BB grade, the single blastocyst transfer could be considered to be performed.

Predictive potential role of glutathione S-transferases polymorphisms in response to chemotherapy and breast cancer prognosis

The aim of this study was to evaluate the role of GSTM1 null/present, GSTT1 null/present, and GSTP1 polymorphisms in the clinical response to chemotherapy and treatment outcome of breast cancer. The GSTM1, GSTT1, and GSTP1 IIe105Val polymorphism genotypes were analyzed using polymerase chain reaction coupled with restriction fragment length polymorphism. Conditional logistic regression analysis revealed that breast cancer patients carrying the GG genotype of GSTP1 IIe105Val showed a significantly better response to chemotherapy compared to those expressing the AA genotype [odds ratio = 2.66, 95% confidence interval (CI) = 1.24-5.91, P = 0.007]. The Cox proportional hazards model indicated that the GG genotype of GSTP1 IIe105Val in breast cancer patients was correlated with a lower risk of death from all causes than those with AA genotype. The adjusted hazard ratio (95%CI) for the GG genotype of GSTP1 IIe105Val was 0.44 (0.18-0.99; P = 0.03). In conclusion, the results of our study indicated that the GG genotype of GSTP1 IIe105Val was significantly associated with better response to chemotherapy and longer overall survival, compared to the wide-type genotype.

Dynamics and Diffusion Mechanism of Low-Density Liquid Silicon

A first-order phase transition from a high-density liquid to a low-density liquid has been proposed to explain the various thermodynamic anomies of water. It also has been proposed that such liquid-liquid phase transition would exist in supercooled silicon. Computer simulation studies show that, across the transition, the diffusivity drops roughly 2 orders of magnitude, and the structures exhibit considerable tetrahedral ordering. The resulting phase is a highly viscous, low-density liquid silicon. Investigations on the atomic diffusion of such a novel form of liquid silicon are of high interest. Here we report such diffusion results from molecular dynamics simulations using the classical Stillinger-Weber (SW) potential of silicon. We show that the atomic diffusion of the low-density liquid is highly correlated with local tetrahedral geometries. We also show that atoms diffuse through hopping processes within short ranges, which gradually accumulate to an overall random motion for long ranges as in normal liquids. There is a close relationship between dynamical heterogeneity and hopping process. We point out that the above diffusion mechanism is closely related to the strong directional bonding nature of the distorted tetrahedral network. Our work offers new insights into the complex behavior of the highly viscous low density liquid silicon, suggesting similar diffusion behaviors in other tetrahedral coordinated liquids that exhibit liquid-liquid phase transition such as carbon and germanium.

Si78 double cage structure and special optical properties

We performed first-principles calculations to study the structural stability of Si78 clusters with or without hydrogen passivation. The calculations reveal that an endohedral double cage isomer is more stable than the diamond-like structure, whereas the opposite is found for the hydrogen passivated isomers. In particular, the hydrogenated double cage and diamond-like structure may display blue shifts to the visible and UV regions, respectively. The IR vibration spectra, ionization potential (IP) and electronic density-of-states of the clusters were calculated and discussed.

Theoretical study on the structures and optical absorption of Si₁₇₂ nanoclusters

The structures and optical properties of silicon nanoclusters (Si NCs) have attracted continuous interest in the last few decades. However, it is a great challenge to determine the structures of Si NCs for accurate property calculation due to the complication and competition of various structural motifs. In this work, a Si172 NC with a size of about 1.8 nm was investigated using a genetic algorithm combined with tight-binding and DFT calculations. We found that a diamond crystalline core with 50 atoms (1.2 nm) was formed in the Si172 NC. It can be expected that at a size of about 172 atoms, a diamond crystalline structure can nucleate from the center of the Si NCs. The optical properties of the pure and hydrogenated Si172 NC structures also have been studied using the TDDFT method. Compared with the pure Si172 NC, the absorption peaks of the hydrogenated Si172 NC are obviously blue-shifted.

New Authentication Scheme for Wireless Body Area Networks Using the Bilinear Pairing

Due to the development of information technologies and network technologies, healthcare systems have been employed in many countries. As an important part of healthcare systems, the wireless body area network (WBAN) could bring convenience to both patients and physicians because it could help physicians to monitor patients' physiological values remotely. It is essential to ensure secure communication in WBANs because patients' physiological values are very sensitive. Recently, Liu et al. proposed an efficient authentication scheme for WBANs. Unfortunately, Zhao pointed out that their scheme suffered from the stolen verifier-table attack. To improve security and efficiency, Zhao proposed an anonymous authentication scheme for WBANs. However, Zhao's scheme cannot provide real anonymity because the users' pseudo identities are constant value and the attack could tract the users. In this paper, we propose a new anonymous authentication scheme for WBANs. Security analysis shows that the proposed scheme could overcome weaknesses in previous scheme. We also use the BAN logic to demonstrate the security of the proposed scheme.