[Differential diagnosis of asthma and dysfunctional breathing and vocal cord dysfunction]

The clinical manifestations of bronchial asthma are complex and variable, which can easily be confused with other diseases. So misdiagnosis and missed diagnosis of asthma are common. In the differential diagnosis of asthma, organic diseases such as left ventricular dysfunction, chronic obstructive pulmonary disease, and upper airway obstruction are most often considered, but the understanding of functional disease is insufficient. In fact, GINA guidelines suggested that the differential diagnosis in adult patients with suspected asthma needed to prioritize functional diseases such as dysfunctional breathing (DB)/hyperventilation syndrome (HVS) and vocal cord dysfunction (VCD), rather than organic disease. Here we review the concepts of DB and VCD and their differentiation from asthma.

Achieving thermally stable nanoparticles in chemically complex alloys via controllable sluggish lattice diffusion

Nanoparticle strengthening provides a crucial basis for developing high-performance structural materials with potentially superb mechanical properties for structural applications. However, the general wisdom often fails to work well due to the poor thermal stability of nanoparticles, and the rapid coarsening of these particles will lead to the accelerated failures of these materials especially at elevated temperatures. Here, we demonstrate a strategy to achieve ultra-stable nanoparticles at 800~1000 °C in a Ni_59.9-xCo_xFe₁₃Cr₁₅Al₆Ti₆B_0.1 (at.%) chemically complex alloy, resulting from the controllable sluggish lattice diffusion (SLD) effect. Our diffusion kinetic simulations reveal that the Co element leads to a significant reduction in the interdiffusion coefficients of all the main elements, especially for the Al element, with a maximum of up to 5 orders of magnitude. Utilizing first-principles calculations, we further unveil the incompressibility of Al induced by the increased concentration of Co plays a critical role in controlling the SLD effect. These findings are useful for providing advances in the design of novel structural alloys with extraordinary property-microstructure stability combinations for structural applications.

High-entropy induced a glass-to-glass transition in a metallic glass

Glass-to-glass transitions are useful for us to understand the glass nature, but it remains difficult to tune the metallic glass into significantly different glass states. Here, we have demonstrated that the high-entropy can enhance the degree of disorder in an equiatomic high-entropy metallic glass NbNiZrTiCo and elevate it to a high-energy glass state. An unusual glass-to-glass phase transition is discovered during heating with an enormous heat release even larger than that of the following crystallization at higher temperatures. Dramatic atomic rearrangement with a short- and medium-range ordering is revealed by in-situ synchrotron X-ray diffraction analyses. This glass-to-glass transition leads to a significant improvement in the modulus, hardness, and thermal stability, all of which could promote their applications. Based on the proposed high-entropy effect, two high-entropy metallic glasses are developed and they show similar glass-to-glass transitions. These findings uncover a high-entropy effect in metallic glasses and create a pathway for tuning the glass states and properties.

Glass-to-glass transitions can help understanding the glass nature, but it remains difficult to tune metallic glasses into significantly different glass states. Here the authors demonstrate the high-entropy effects in glass-to-glass transitions of high-entropy metallic glasses.

Ultrahigh-strength and ductile superlattice alloys with nanoscale disordered interfaces

Alloys that have high strengths at high temperatures are crucial for a variety of important industries including aerospace. Alloys with ordered superlattice structures are attractive for this purpose but generally suffer from poor ductility and rapid grain coarsening. We discovered that nanoscale disordered interfaces can effectively overcome these problems. Interfacial disordering is driven by multielement cosegregation that creates a distinctive nanolayer between adjacent micrometer-scale superlattice grains. This nanolayer acts as a sustainable ductilizing source, which prevents brittle intergranular fractures by enhancing dislocation mobilities. Our superlattice materials have ultrahigh strengths of 1.6 gigapascals with tensile ductilities of 25% at ambient temperature. Simultaneously, we achieved negligible grain coarsening with exceptional softening resistance at elevated temperatures. Designing similar nanolayers may open a pathway for further optimization of alloy properties.

[An epidemiological survey on clinical features, self-management and cognitive level of elderly asthmatics in China]

Objective: To investigate the prevalence of asthma among the elderly people in China and to analyze the clinical features, self-management and cognitive level of elderly asthma patients. Methods: According to the multi-stage random cluster sampling methods, a total of 164 215 subjects were visited by a questionnaire in the last epidemiology survey from eight provinces (Beijing, Shanghai, Guangdong, Liaoning, Henan, Shanxi, Jiangsu, Sichuan provinces) and seven regions (north, northeast, southern china, east, south, southwest and northwest) in China from February 2010 to August 2012. 2 034 were diagnosed as asthma. The elderly patients aged ≥65 years were selected from the 2 034 asthma patients. The clinical characteristics, comorbidities, the status of asthma control and self-management and insights of the disease in elderly asthma patients were analyzed. Results: Among the 2 034 asthma patients, 584 (28.7%) were elderly asthmatics aged ≥65 years old and 1 450 (71.3%) were<65 years old. In the elderly asthma group, Early-onset asthma accounted for 439 (75.2%) and 145 (24.8%) were late-onset. The common clinical manifestations of elderly asthma patients were: chest distress 395 (67.6%), wheezing 304 (52.1%), cough 298 (51.0%). Common comorbidities of elderly asthmatics were: chronic obstructive pulmonary disease 144 (24.7%), allergic rhinitis 122(20.9%), gastroesopheal reflux disease (GERD) 114(19.5%), allergic conjunctivitis 86 (14.7%), eczema 82 (14.0%), chronic bronchitis 76 (13.0%). The Asthma Control Test (ACT) scores of elderly asthmatics and non-elderly asthmatics were (18.5±3.2) and (21.7±3.4) respectively. There was a significant difference between the two groups (P=0.042). Of the elderly asthmatics, only 13 (2.2%) patients monitored daily using a peak flow meter. 93 (15.9%) patients aware that asthma was characterized by chronic airway inflammation. 64 (11.0%) asthmatics understood that the treatment goal. Conclusions: The clinical manifestations of elderly asthmatics are atypical, especially paroxysmal wheezing. Asthma in elderly people causes more comorbidities and mortality. The self-management and cognitive level of patients with asthma needs to be improved.

[A survey on clinical characteristics and risk factors of severe asthma in China]

Objective: To investigate the clinical characteristics and risk factors of severe bronchial asthma in Chinese people over 14 years old. Methods: According to the multi-stage random cluster sampling methods, a total of 164 215 subjects were visited by a questionnaire in the epidemiology survey from eight provinces (Beijing, Shanghai, Guangdong, Liaoning, Henan, Shanxi, Jiangsu, Sichuan provinces) located in seven regions (north, northeast, east, central China, south, southwest and northwest) of China from February 2010 to August 2012. A total of 2 034 were diagnosed as asthma. The clinical characteristics and related risk factors of patients with severe asthma in China were analyzed. Results: Among all asthma patients, 560 were newly diagnosed, accounting for 27.5% (560/2 034) and the percentage of previously confirmed patients was 72.5% (1 474/2 034). A total of 145 were eligible for severe asthma, accounting for 9.8% (145/1 474) of previously confirmed asthmatics and 7.1% (145/2 034) of all asthmatics. 83.5% (121/145) severe asthmatics had at least one trigger factor. Correlation analysis showed that the risk factors of severe asthma were: smoking (OR=1.543, 95%CI: 1.250-1.814), obesity (OR=2.186, 95%CI: 1.972-2.354), petting (OR=2.135, 95%CI: 1.904-2.283), combined with allergic rhinitis (OR=3.456, 95%CI: 2.721-4.326), gastroesophageal reflux disease (OR=1.842, 95%CI: 1.682-2.140), bronchiectasis (OR=1.665, 95%CI: 1.347-1.912) or chronic obstructive pulmonary disease (OR=1.312, 95%CI: 1.171-1.694). Conclusions: The most common comorbidities in severe asthmatics in China are allergic rhinitis and gastroesophageal reflux disease. The risk factors of severe asthma include obesity, allergic rhinitis, gastroesophageal reflux disease, chronic obstructive pulmonary disease, bronchiectasis, smoking and petting.

Dual heterogeneous structures lead to ultrahigh strength and uniform ductility in a Co-Cr-Ni medium-entropy alloy

Alloys with ultra-high strength and sufficient ductility are highly desired for modern engineering applications but difficult to develop. Here we report that, by a careful controlling alloy composition, thermomechanical process, and microstructural feature, a Co-Cr-Ni-based medium-entropy alloy (MEA) with a dual heterogeneous structure of both matrix and precipitates can be designed to provide an ultra-high tensile strength of 2.2 GPa and uniform elongation of 13% at ambient temperature, properties that are much improved over their counterparts without the heterogeneous structure. Electron microscopy characterizations reveal that the dual heterogeneous structures are composed of a heterogeneous matrix with both coarse grains (10∼30 μm) and ultra-fine grains (0.5∼2 μm), together with heterogeneous L1₂-structured nanoprecipitates ranging from several to hundreds of nanometers. The heterogeneous L1₂ nanoprecipitates are fully coherent with the matrix, minimizing the elastic misfit strain of interfaces, relieving the stress concentration during deformation, and playing an active role in enhanced ductility.

Improving both strength and ductility simultaneously in structural metals and alloys remains a challenge. Here, the authors design a heterogeneous structure in a Co-Cr-Ni alloy that results in ultrahigh strength and significant uniform elongation.

[The efficacy and safety of tiotropium/olodaterol fixed-dose combination in Chinese patients with chronic obstructive pulmonary disease: a pooled subgroup analysis of TONADO 1+2]

Objective: To compare the efficacy and safety profiles of tiotropium/olodaterol with the mono-components in Chinese and total study population from TONADO trial. Methods: In the replicate, double-blind, parallel-group, active-controlled, randomized, 52-week, Phase Ⅲ TONADO studies (TONADO 1+2), patients received tiotropium/olodaterol, tiotropium, or olodaterol via the Respimat(®) Inhaler (Boehringer Ingelheim, Germany). Primary end points were forced expiratory volume in 1 second (FEV(1)) area under the curve from 0 to 3 hours (AUC(0-3h)) response and trough FEV(1) response, and St George's respiratory questionnaire (SGRQ) total score at 24 weeks. Adverse events were also collected. This subgroup analysis only focused on the efficacy and safety of the drug at the approved dose in China. Results: 548 Chinese patients were randomized, aged 41 to 82 years [mean age, (63±8) years] and most were male (526, 96%), 111 received tiotropium/olodaterol 5/5 μg, and 127 received tiotropium 5 μg and 95 received olodaterol 5 μg. The baseline characteristics of these groups were similar. After 24 weeks, treatment with tiotropium/olodaterol 5/5 μg, tiotropium 5 μg and olodaterol 5 μg resulted in an adjusted mean FEV(1) AUC(0-3h) response of 0.240, 0.157 and 0.079 L, and trough FEV(1) response of 0.117, 0.068 and-0.001 L, respectively. Tiotropium/olodaterol 5/5 μg significantly improved SGRQ scores in Chinese patients compared with olodaterol 5 μg (32.729 and 37.202, respectively). Generally, the safety profile of tiotropium/olodaterol was comparable with mono-components in 52 weeks. Conclusion: Compared with tiotropium or olodaterol, tiotropium/olodaterol in Chinese patients provided significant improvement in lung function and quality of life, and the safety profiles were similar.

[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.

[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.

Multicomponent intermetallic nanoparticles and superb mechanical behaviors of complex alloys

Alloy design based on single–principal-element systems has approached its limit for performance enhancements. A substantial increase in strength up to gigapascal levels typically causes the premature failure of materials with reduced ductility. Here, we report a strategy to break this trade-off by controllably introducing high-density ductile multicomponent intermetallic nanoparticles (MCINPs) in complex alloy systems. Distinct from the intermetallic-induced embrittlement under conventional wisdom, such MCINP-strengthened alloys exhibit superior strengths of 1.5 gigapascals and ductility as high as 50% in tension at ambient temperature. The plastic instability, a major concern for high-strength materials, can be completely eliminated by generating a distinctive multistage work-hardening behavior, resulting from pronounced dislocation activities and deformation-induced microbands. This MCINP strategy offers a paradigm to develop next-generation materials for structural applications.

Nanoscale Structural Evolution and Anomalous Mechanical Response of Nanoglasses by Cryogenic Thermal Cycling

One of the central themes in the amorphous materials research is to understand the nanoscale structural responses to mechanical and thermal agitations, the decoding of which is expected to provide new insights into the complex amorphous structural-property relationship. For common metallic glasses, their inherent atomic structural inhomogeneities can be rejuvenated and amplified by cryogenic thermal cycling, thus can be decoded from their responses to mechanical and thermal agitations. Here, we reported an anomalous mechanical response of a new kind of metallic glass (nanoglass) with nanoscale interface structures to cryogenic thermal cycling. As compared to those metallic glasses by liquid quenching, the Sc₇₅Fe₂₅ (at. %) nanoglass exhibits a decrease in the Young's modulus but a significant increase in the yield strength after cryogenic cycling treatments. The abnormal mechanical property change can be attributed to the complex atomic rearrangements at the short- and medium- range orders due to the intrinsic nonuniformity of the nanoglass architecture. The present work gives a new route for designing high-performance metallic glassy materials by manipulating their atomic structures and helps for understanding the complex atomic structure-property relationship in amorphous materials.

[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.

UFD1 contributes to MYC-mediated leukemia aggressiveness through suppression of the proapoptotic unfolded protein response

Despite the pivotal role of MYC in tumorigenesis, the mechanisms by which it promotes cancer aggressiveness remain incompletely understood. Here we show that MYC transcriptionally upregulates the ubiquitin fusion degradation 1 (UFD1) gene in T-cell acute lymphoblastic leukemia (T-ALL). Allelic loss of ufd1 in zebrafish induces tumor-cell apoptosis and impairs MYC-driven T-ALL progression but does not affect general health. As the E2 component of an endoplasmic reticulum (ER)-associated degradation (ERAD) complex, UFD1 facilitates the elimination of misfolded/unfolded proteins from the ER. We found that UFD1 inactivation in human T-ALL cells impairs ERAD, exacerbates ER stress, and induces apoptosis. Moreover, we show that UFD1 inactivation promotes the proapoptotic unfolded protein response (UPR) mediated by protein kinase RNA-like ER kinase (PERK). This effect is demonstrated by an upregulation of PERK and its downstream effector C/EBP homologous protein (CHOP), as well as a downregulation of BCL2 and BCLxL. Indeed, CHOP inactivation or BCL2 overexpression is sufficient to rescue tumor-cell apoptosis induced by UFD1 knockdown. Together, our studies identify UFD1 as a critical regulator of the ER stress response and a novel contributor to MYC-mediated leukemia aggressiveness, with implications for targeted therapy in T-ALL and likely other MYC-driven cancers.

Tuning the indirect–direct band gap transition in the MoS2−xSex armchair nanotube by diameter modulation

The indirect–direct band gap transition is observed in armchair nanotubes MoSSe and MoSe₂ by diameter modulation.

Development of a data-processing method based on Bayesian k-means clustering to discriminate aneugens and clastogens in a high-content micronucleus assay

Genotoxicants can be identified as aneugens and clastogens through a micronucleus (MN) assay. The current high-content screening-based MN assays usually discriminate an aneugen from a clastogen based on only one parameter, such as the MN size, intensity, or morphology, which yields low accuracies (70-84%) because each of these parameters may contribute to the results. Therefore, the development of an algorithm that can synthesize high-dimensionality data to attain comparative results is important. To improve the automation and accuracy of detection using the current parameter-based mode of action (MoA), the MN MoA signatures of 20 chemicals were systematically recruited in this study to develop an algorithm. The results of the algorithm showed very good agreement (93.58%) between the prediction and reality, indicating that the proposed algorithm is a validated analytical platform for the rapid and objective acquisition of genotoxic MoA messages.

Direct separation of arsenic and antimony oxides by high-temperature filtration with porous FeAl intermetallic

A temperature-controlled selective filtration technology for synchronous removal of arsenic and recovery of antimony from the fume produced from reduction smelting process of lead anode slimes was proposed. The chromium (Cr) alloyed FeAl intermetallic with an asymmetric pore structure was developed as the high-temperature filter material after evaluating its corrosive resistance, structural stability and mechanical properties. The results showed that porous FeAl alloyed with 20wt.% Cr had a long term stability in a high-temperature sulfide-bearing environment. The separation of arsenic and antimony trioxides was realized principally based on their disparate saturated vapor pressures at specific temperature ranges and the asymmetric membrane of FeAl filter elements with a mean pore size of 1.8μm. Pilot-scale filtration tests showed that the direct separation of arsenic and antimony can be achieved by a one-step or two-step filtration process. A higher removal percentage of arsenic can reach 92.24% at the expense of 6∼7% loss of antimony in the two-step filtration process at 500∼550°C and 300∼400°C. The FeAl filters had still good permeable and mechanical properties with 1041h of uninterrupted service, which indicates the feasibility of this high-temperature filtration technology.

[The relationship between smoking status and epidermiology of asthma in people aged over 14 years in China]

Objective: To study the relationship between bronchial asthma and smoking status in Chinese people. Methods: Asthma epidemiological survey and stratified-cluster-random method survey were performed in residents over 14 years in 8 provinces (cities) of China from February 2010 to August 2012. Asthma was diagnosed based upon case history, clinical signs and lung function test. Smoking status was investigated by questionnaire. Results: Sampling population was 180 099 and 164 215 were valid. A total of 2 034 subjects were diagnosed as asthma including 79 692 men and 84 523 women. The overall prevalence rate of asthma was 1.24% (2 034/164 215). Smokers were 23.8% (39 137/164 215) in the whole population. Smokers were 34.5% (702/2 034) in asthmatic patients, compared with 23.7% (38 435/162 181) in no-asthmatic population. The incidence of asthma was 1.79% and 1.06% in smokers and non-smokers respectively (P<0.001), suggesting that OR of smoking was 1.70 (95% CI 1.55-1.86, P<0.001). According to asthma control test (ACT) score, the level of asthma control in non smoking group was higher than that in smoking group(43.2% vs 35.3%). The times of hospitalization due to acute exacerbations(0.51 vs 0.41 events/person/year), total hospitalization rate(27.35% vs 20.12%), annual emergency room visits (0.80 vs 0.60 events/person/year) and emergency room visit rate (31.77% vs 24.47%) were all much higher in smoking asthmatic patients than those in non smoking asthmatic patients, indicating that the level of asthma control in smoking patients was significantly worse than in non smoking patients. Conclusions: The smoking rate in Chinese people over 14 years is still high. The prevalence rate of asthma in smokers is significantly higher than that of non-smokers. The level of asthma control in smokers is significantly worse than that in non smokers.

[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.

[A cross-section study of severe asthma in eight provinces of China]

Objective: To analyze the prevalence of severe asthmain China. Methods: The epidemiological data was collected from 2 034 asthmatics who were diagnosed in the last epidemiological survey from 2009 to 2010 in 8 provinces. Results: According to the questionnaire survey, among the 2 034 patients, the previously diagnosed patients accounted for 72.47% (1 474/2 034) and the percentage of newly-diagnosed patients was 27.53% (560/2 034). In those 1 474 previously diagnosed asthmatics, 122 (8.28%) were classified into severe asthma, while 6.00% (122/2 034) of all asthmatics and 0.07% (122/164 215) of total respondents presented as severe cases. Statistically, there was no difference in the prevalence of severe patients between men and women. The morbidity rate of severe asthma was the lowest in the 21-30 year old group and the highest in 61-70 year old group (0.85% and 8.31% respectively). The difference among ages was statistically significant (χ²=18.791, P=0.005). In addition, the prevalence rates of severe asthma were also significantly diverged among patients with different education background(χ²=24.639, P<0.000 1). A negative relation was found between education level and the proportion of severe cases. Moreover, the morbidity of severe asthma in smoking patients and non-smoking patients were significantly different as well (χ²=7.447, P<0.05). Compared with asthma patients who do not smoke, smokers were more likely to suffer severe asthma (OR=1.663, 95% CI 1.150-2.404). Conclusions: The prevalence rate of severe asthma in China is similar to that in other countries.Elderly patients have higher risk of severe asthma. Smoking is considered as a risk factor for severe asthma.

First-principles computation of electron transfer and reaction rate at a perovskite cathode for hydrogen production

The focus of this research is on the electron transfer and its reaction rate at the perovskite cathode of a photoelectrochemical cell for hydrogen production. By employing the density functional theory (DFT), the electron density, projected density of states (PDOS), electron distribution and electron transfer path between [Fe-Fe] hydrogenase and the perovskite cathode can be obtained. Simulation results show that the perovskite cathode is better than traditional cathodes for hydrogen production. Before transmission to the [Fe-Fe] hydrogenase, electron clouds mainly aggregate at the periphery of amine molecules. Simulations also show that the key to hydrogen production at the perovskite structure lies in the organic molecules. Electrons are transferred to the hydrocarbon structural chain before reaching the Fe atoms. The Rice, Ramsperger, Kassel and Marcus (RRKM) theory was used to predict the reaction rates at different temperatures. It was found that the reaction rates are in good agreement with the experimental results. This research provides more physical insight into the electron transfer mechanism during the hydrogen production process.

Imputing rare variants in families using a two-stage approach

BACKGROUND

Recent focus on studying rare variants makes imputation accuracy of rare variants an important issue. Many approaches have been proposed to increase imputation accuracy among rare variants, from reference panel selection to combinations of existing methods to multistage analyses. We aimed to bring the strengths of these new approaches together with our proposed two-stage imputation for family data.

METHODS

Our imputation methods were tested on the region from 46.75Mb to 49.25Mb on chromosome 3. We did quality control based on the proportion of missing genotypes per variant and individual, leaving 495 individuals with 761 genome-wide association studies (GWAS) variants only, 45 with 14,077 sequence variants only, and 419 with both GWAS and sequencing data. All data were prephased using SHAPEIT2 with a duo hidden Markov model algorithm prior to performing imputation. Imputations were performed 100 times, each time masking the sequence data for 1 individual and imputing it from the GWAS data. We used well-imputed genotypes, defined as a probability of greater than 0.9, above 2 different minor allele frequency cutoffs-0.01 and 0.05-from Impute2 as input for Merlin, and compared these results to Impute2 and Merlin separately. The imputed results were evaluated using correlation measurement and the imputation quality score.

RESULTS

Our method improved imputation accuracy, measured by imputation quality score, for variants with minor allele frequency between 0.01 and 0.40, but failed to improve accuracy for variants with minor allele frequency less than 0.01 when we used a minor allele frequency cutoff of 0.01 for the Impute2 results. In contrast, our 2-stage approach with a minor allele frequency cutoff of 0.05 performed the worst of all methods for variants with minor allele frequency between 0.01 and 0.40.

CONCLUSIONS

This method gave promising results, but may be further improved by changing the inclusion criteria of Impute2 variants. More analyses are needed on a larger region with different inclusion thresholds to assess the accuracy of this approach.

Kinetic ways of tailoring phases in high entropy alloys

The comprehensive performance of high entropy alloys (HEAs) depends on the phase selection significantly. However, up to now, investigations of the phase selection in HEAs mainly focused on the thermodynamic equilibrium phase, while kinetic ways of tailoring the phases in HEAs are seldom considered. In HEAs, the kinetics of sluggish diffusion and the numerous possible phases make the kinetics of phase transformation more complex and intriguing. Here, the kinetic effect in CoCrFeNiTi_0.4 HEAs was investigated to reveal the possibility of controlling phase selection via kinetic ways for HEAs. The σ, γ′ and R phases in the CoCrFeNiTi_0.4 HEA can be controlled under different cooling rate both in solidification and solid transformation. The theoretical analyses revealed the kinetic effect on phase selection. The method proposed here, tailoring the phases with different kinetic ways, could be used to prepare promising HEAs with very rich composition design.

Polysynthetic twinned TiAl single crystals for high-temperature applications

TiAl alloys are lightweight, show decent corrosion resistance and have good mechanical properties at elevated temperatures, making them appealing for high-temperature applications. However, polysynthetic twinned TiAl single crystals fabricated by crystal-seeding methods face substantial challenges, and their service temperatures cannot be raised further. Here we report that Ti-45Al-8Nb single crystals with controlled lamellar orientations can be fabricated by directional solidification without the use of complex seeding methods. Samples with 0° lamellar orientation exhibit an average room temperature tensile ductility of 6.9% and a yield strength of 708 MPa, with a failure strength of 978 MPa due to the formation of extensive nanotwins during plastic deformation. At 900 °C yield strength remains high at 637 MPa, with 8.1% ductility and superior creep resistance. Thus, this TiAl single-crystal alloy could provide expanded opportunities for higher-temperature applications, such as in aeronautics and aerospace.

Structural Signature of Plasticity Unveiled by Nano-Scale Viscoelastic Contact in a Metallic Glass

Room-temperature plasticity in metallic glasses (MGs) is commonly associated with local structural heterogeneity; however, direct observation of the subtle structural change caused by plasticity is vitally important but the data are extremely scarce. Based on dynamic atomic force microscopy (DAFM), here we show that plasticity-induced structural evolution in a Zr-Ni MG can be revealed via nano-scale viscoelastic contacts between an AFM tip and plastically deformed MG surface layers. Our experimental results clearly show a spatial amplification of the nano-scale structural heterogeneity caused by the distributed plastic flow, which can be linked to the limited growth, reorientation and agglomeration of some nano-scale energy-absorbing regions, which are reminiscent of the behavior of the defect-like regions with non-affine deformation as conceived in many theories and models. Furthermore, we are able to experimentally extract the thermodynamic properties of these nano-scale regions, which possess an energy barrier of 0.3–0.5 eV, about half of that for a typical shear transformation event that usually occurs at the onset of plasticity. The outcome of our current work sheds quantitative insights into the correlation between plasticity and structural heterogeneity in MGs.

Shear-banding Induced Indentation Size Effect in Metallic Glasses

Shear-banding is commonly regarded as the “plasticity carrier” of metallic glasses (MGs), which usually causes severe strain localization and catastrophic failure if unhindered. However, through the use of the high-throughput dynamic nanoindentation technique, here we reveal that nano-scale shear-banding in different MGs evolves from a “distributed” fashion to a “localized” mode when the resultant plastic flow extends over a critical length scale. Consequently, a pronounced indentation size effect arises from the distributed shear-banding but vanishes when shear-banding becomes localized. Based on the critical length scales obtained for a variety of MGs, we unveil an intrinsic interplay between elasticity and fragility that governs the nanoscale plasticity transition in MGs. Our current findings provide a quantitative insight into the indentation size effect and transition mechanisms of nano-scale plasticity in MGs.

Origin of Shear Stability and Compressive Ductility Enhancement of Metallic Glasses by Metal Coating

Metallic glasses (MGs) are notorious for the poor macroscopic ductility and to overcome the weakness various intrinsic and extrinsic strategies have been proposed in past decades. Among them, the metal coating is regarded as a flexible and facile approach, yet the physical origin is poorly understood due to the complex nature of shear banding process. Here, we studied the origin of ductile enhancement in the Cu-coating both experimentally and theoretically. By examining serrated shear events and their stability of MGs, we revealed that the thin coating layer plays a key role in stopping the final catastrophic failure of MGs by slowing down shear band dynamics and thus retarding its attainment to a critical instable state. The mechanical analysis on interplay between the coating layer and shear banding process showed the enhanced shear stability mainly comes from the lateral tension of coating layer induced by the surface shear step and the bonding between the coating layer and MGs rather than the layer thickness is found to play a key role in contributing to the shear stability.

Unusual fast secondary relaxation in metallic glass

The relaxation spectrum of glassy solids has long been used to probe their dynamic structural features and the fundamental deformation mechanisms. Structurally complicated glasses, such as molecular glasses, often exhibit multiple relaxation processes. By comparison, metallic glasses have a simple atomic structure with dense atomic packing, and their relaxation spectra were commonly found to be simpler than those of molecular glasses. Here we show the compelling evidence obtained across a wide range of temperatures and frequencies from a La-based metallic glass, which clearly shows two peaks of secondary relaxations (fast versus slow) in addition to the primary relaxation peak. The discovery of the unusual fast secondary relaxation unveils the complicated relaxation dynamics in metallic glasses and, more importantly, provides us the clues which help decode the structural features serving as the ‘trigger' of inelasticity on mechanical agitations.

Mechanical relaxation processes in glasses can provide information on the structural and mechanical properties of glasses. Here, the authors observe a fast secondary relaxation process in La-based metallic glasses, providing information on the inelasticity of metallic glasses.

Activin A is associated with asthma in underweight and overweight patients

There are limited data regarding the effects of activin A on underweight, normal weight, and overweight patients with asthma. We determined serum levels of activin A in asthmatic patients in relation to body mass index. The study protocol included questionnaires, measurement of exhaled nitric oxide, blood sampling for inflammatory biomarkers, and high-resolution computed tomography of the lungs to identify bronchial wall thickening. Serum and sputum activin A levels were measured using an enzyme-linked immunosorbent assay in 94 asthmatic patients. Mean serum levels of activin A were significantly (P = 0.001) higher in underweight (1781 ± 327.3 pg/mL) than in normal weight and overweight asthmatic patients, regardless of gender. After stratification by gender, significantly higher mean values of activin A were observed in females compared to males in the normal and underweight groups (P = 0.003 and P = 0.0002, respectively). Significant differences between groups were found in airway wall area (%) (P < 0.0001). We also observed a much higher percentage of sputum lymphocytes in the underweight group compared to the other groups (P < 0.0001). Correlations between bronchial wall thickness and activin A were found in the underweight (r = 0.67, P = 0.48) and normal weight groups (r = 0.51, P = 0.042). Correlations between fractional of exhaled nitric oxide, forced expiratory volume in 1 s, delayed treatment years, and activin A in different groups were also observed. Increased serum level of activin A indicates its role in the pathogenesis of asthma, particularly in underweight and overweight patients.

Mo doped porous Ni–Cu alloy as cathode for hydrogen evolution reaction in alkaline solution

Molybdenum doped porous Ni–Cu cathodes are conveniently prepared by powder metallurgy in this work.

Vitamin D with asthma and COPD: not a false hope? A systematic review and meta-analysis

Vitamin D deficiency and insufficiency are increasingly being recognized in the general population over the last few decades. However, a number of other disorders have now been linked to vitamin D deficiency and insufficiency, including asthma and COPD. The aim of this study was to evaluate the evidence on the effect of vitamin D on asthma and COPD. We searched electronic databases including SCI, EMBASE, Ovid, and PubMed. Reviewers working independently and in duplicate extracted study characteristics, quality, and the outcomes. The weighted mean differences across trials and random-effect meta-analysis were used to pool the relative risks (RR). This is the first meta-analysis about the risk of vitamin D deficiency for asthma and COPD. Ten studies were available for this meta-analysis and systematic review. The prevalence of vitamin D deficiency was significantly greater among cases than control subjects [RR=1.59, 95%CI=1.07-2.36, 488/812 (60%) vs 278/875 (32%)] for asthma. However, vitamin D insufficiency was not significantly associated with asthma [RR=1.09, 95%CI=0.91-1.30, 702/996 (70%) vs 665/1016 (65%)]. Moreover, studies failed to demonstrate that COPD patients had an increased risk for vitamin D deficiency or insufficiency compared to controls (RR=0.89, 95%CI=0.63-1.25). Vitamin D deficiency was associated with a significant decrease in lung function in asthmatic children. Vitamin D deficiency was highly prevalent in asthma patients, and vitamin D status was associated with lung function. COPD cannot be considered as completely free of vitamin D deficiency.

Atomic structure of nanoclusters in oxide-dispersion-strengthened steels

Oxide-dispersion-strengthened steels are the most promising structural materials for next-generation nuclear energy systems because of their excellent resistance to both irradiation damage and high-temperature creep. Although it has been known for a decade that the extraordinary mechanical properties of oxide-dispersion-strengthened steels originate from highly stabilized oxide nanoclusters with a size smaller than 5 nm, the structure of these nanoclusters has not been clarified and remains as one of the most important scientific issues in nuclear materials research. Here we report the atomic-scale characterization of the oxide nanoclusters using state-of-the-art Cs-corrected transmission electron microscopy. This study provides compelling evidence that the nanoclusters have a defective NaCl structure with a high lattice coherency with the bcc steel matrix. Plenty of point defects as well as strong structural affinity of nanoclusters with the steel matrix seem to be the most important reasons for the unusual stability of the clusters at high temperatures and in intensive neutron irradiation fields.

Novel C/Cu sheath/core nanostructures synthesized via low-temperature MOCVD

C/Cu sheath/core nanocable arrays were mass-produced on various substructures, such as Si, SiO(2), Cu or glass, by using a one-step low-temperature metal-organic chemical vapor deposition. The novel nanostructures consist of a faceted Cu nanowire core with six side surfaces and four top surfaces, and a sheath of carbon. The as-synthesized nanocables are demonstrated excellent oxidization resistance and field emission properties, and are expected to be excellent candidates as nano-interconnectors, or nanocables, in electronic devices and nano-emitters for field emissions.

Atomic-scale structural evolution and stability of supercooled liquid of a Zr-based bulk metallic glass

In this Letter, direct experimental evidence is provided for understanding the thermal stability with respect to crystallization in the Zr(41.2)Ti(13.8)Cu(12.5)Ni(10)Be(22.5) glass-forming liquid. Through high-resolution transmission electron microscopy, the atomic-structure evolution in the glass-forming liquid during the isothermal annealing process is clearly revealed. In contrast with the existing theoretical models, our results reveal that, prior to nanocrystallization, there exists a metastable state prone to forming icosahedralike atomic clusters, which impede the subsequent crystallization and hence stabilize the supercooled liquid. The outcome of the current research underpins the topological origin for the excellent thermal stability displayed by the Zr-based bulk metallic glass.

A Closer “Look” at Modern Gate Oxides

Using high resolution TEM (HRTEM), we identified some process induced ‘weak spots’ in SiO2 layers: First, we observed thinning in the periphery of the transistor, i. e. near the boundary to the shallow trench isolation. At the boundary to the shallow trench, the Si substrate gradually changes its orientation from <100> to <110>, which results in an unexpected oxidation behavior in this region. Secondly, we observed the intrusion of poly-Si grains from the gate into the gate oxide, resulting in local thinning of the dielectric. Using image simulations, we show that conventional high resolution TEM can reveal the interface roughness only to a very limited extend.

Structure Maps and Phase Stability in AlTi3 Alloyed with Rare-Earth Elements

Rare-earth elements including Y, Er and Sc were added to AlTi3 for stabilizing the Ll2 ordered crystal structure, as predicted by the AB3 structure map. The crystal structure and phase composition in the AlTi3 alloys were studied by electron microprobe analysis, X-ray diffraction and TEM. The solubility limit of the rare-earth elements were determined and correlated with the atomic size factor. The results obtained so far indicate that rare-earth additions are unable to change the crystal structure of AlTi3 from DO19 to Ll2. The inability to stabilize the Ll2 structure demonstrates the need to characterize the structure map domains with a further period-dependent parameter.

Effect of Preoxidation and Grain Size on Ductility of a Boron-Doped Ni3Al at Elevated Temperatures

The ductility of preoxidized Ni3Al (Ni-23Al-0.5Hf-0.2B, at.%) specimens with various grain sizes (17∼193 μm) was evaluated by means of tensile tests at 600 and 760°C in vacuum. It was found that the preoxidation does not affect the ductility of the finest-grained material at either temperature, whereas it causes severe embrittlement in the largest-grained material, especially at 760°C. A continuous, thin Al-rich oxide layer, which forms on the fine-grained samples, protects the underlying alloy from oxygen penetration, preventing any loss of ductility, whereas the nickel-rich oxide which forms on the large-grained samples allows oxygen to penetrate along grain boundaries, causing severe embrittlement. The grain boundaries act as short-circuit paths for rapid diffusion of aluminum atoms from the bulk to the surfaces, and this is responsible for the difference in oxidation behavior between fine- and large-grained materials. The embrittlement of large-grained samples can be eliminated through control of oxide formation on Ni3Al surfaces.

On the Correlation of the Hardness of B2 Compounds with Point Defect Concentrations

Point defects such as vacancies and anti-site atoms are known to strongly affect the mechanical properties of B2 compounds. The variations in the hardness of these compounds with composition and quenching temperature can often be correlated with the concentrations of these point defects. Simple themodynamic models using a quasi-chemical approach can be used to estimate the concentrations of point defects with composition and temperature. These estimates can often be supported by experimental methods. Knowledge of the concentrations of defects can then be compared to the variations in hardness using solid solution strengthening models. A consistent relationship is found for several B2 compounds. The hardening rates of vacancies are found to be greater than those of anti-site atoms. B2 compounds having the anti-structure defect structure (AuZn, FeCo) are investigated as well as those with the triple-defect structure (FeAl, NiAl, CoAl).

Design of Ductile Polycrystalline Ni3 Al Alloys

This paper provides a comprehensive review of current efforts on design of ductile polycrystalline Ni3 AI alloys. Microalloying has proven to be very effective in alleviating the grain-boundary emibrittlement problem. The ductility and fabricability of Ni3 Al (24 at. % Al) are dramatically improved by adding a few hundred parts per million of boron. The beneficial effect of boron is related to its unusual segregation behavior as predicted from the theory of grain-boundary cohesion developed by Rice, based on thermodynamic analyses. Alloy stoichiometry strongly influences grain-boundary chemistry, which, in turn, affects the boundary cohesion and overall ductility of Ni3 Al.

The solid-solution hardening of Ni3 AI depends on the substitutional behavior of alloying elements, atomic size misfit, and the degree of nonstoichiometry of the alloy. Hafnium additions are very effective in improving high-temperature properties of ternary Ni3Al (Al + Hf = 24 at. %) doped with boron. Alloying with <2% Hf substantially increases the yield stress and raises the peak-strength temperature. In addition, hafnium substantially improves creep properties and oxidation resistance. The Ni3 Al aluminides truly represent a new series of heat resistant materials which do not depend on chromium for oxidation resistance.

Metallic liquids and glasses: atomic order and global packing

In this Letter, we have revealed the common structural behavior of metallic glasses through scrutinizing the evolution of pair distribution functions from metallic liquids to glasses and statistically analyzing pair distribution functions of 64 metallic glasses. It is found that the complex atomic configuration in metallic glasses can be interpreted globally as a combination of the spherical-periodic order and local translational symmetry. The implications of our study suggest that the glass transition could be visualized mainly as a process involving in local translational symmetry increased from the liquid to glassy states.

Atomistic free-volume zones and inelastic deformation of metallic glasses

The amorphous nature of metallic glasses and their mechanical properties make them interesting for structural applications. However, the interplay between the nature of atomic structures in metallic glasses and mechanical properties remains poorly understood. In this study, high-frequency dynamic micropillar tests have been used to probe both atomic clusters and flow defects in metallic glasses. We show that loosely bonded atomistic free-volume zones that are enveloped elastically by tightly bonded atomic clusters show a deformation character similar to supercooled liquids. At room temperature, the effective viscosity of these free-volume zones is of the order of 1 x 10(8) Pa s before the occurrence of shear banding. The confined liquid-like deformation of free-volume zones leads to significant mechanical hysteresis in micropillars under dynamic loading, providing important insight into how atomistic structural features affect the deformation behaviours in metallic glasses in the apparent elastic regime. The inelastic behaviour also serves as the basis for the superior damping resistance of metallic glasses.