The Periodic Instability of Diameter of ZnO Nanowires via a Self-oscillatory Mechanism

ZnO nanowires with a periodic instability of diameter were successfully prepared by a thermal physical vapor deposition method. The morphology of ZnO nanowires was investigated by SEM. SEM shows ZnO possess periodic bead-like structure. The instability only appears when the diameter of ZnO nanowires is small. The kinetics and mechanism of Instability was discussed at length. The appearance of the instability is due to negative feed-back mechanism under certain experimental conditions (crystallization temperature, vapor supersaturation, etc)

Quasi-in-situ observing the rare earth texture evolution in an extruded Mg-Zn-Gd alloy with bimodal microstructure

The static recrystallization and associated texture evolution were investigated in an extruded Mg-Zn-Gd alloy with bimodal microstructure based on a quasi-in-situ electron back-scatter diffraction (EBSD) method. The typical rare earth (RE) texture formed during annealing, evolving from the bimodal microstructure with [101¯0] basal fiber texture that consisted of fine recrystallized (RXed) grains and coarse unrecrystallized (unRXed) grains elongated along the extrusion direction. In both RXed and unRXed regions, the RXed nucleation produced randomized orientations without preferred selection and the RXed grains with RE texture orientation had more intensive growth ability than those with basal fiber orientation, thereby leading to the preferred selection of RE texture orientation during grain growth. The relationships between stored strain energy, solute drag, grain growth and texture evolution are discussed in detail. This study provided direct evidence of the RE texture evolution in an extruded Mg-RE alloy, which assists in understanding the formation mechanisms for RE texture during extrusion and better developing wrought Mg alloys with improved formability

The incidence of cancer deaths among hypertensive patients in a large Chinese population: a cohort study

Current evidence is mixed regarding the association between antihypertensive prescriptions and cancer mortality. We evaluated this association in a large Chinese hypertensive population. We followed for five years all patients who were prescribed their first-ever antihypertensive agents between 2001 and 2005 in a public healthcare sector of Hong Kong. The association between antihypertensive drug class and cancer mortality was evaluated by Cox proportional hazard models with propensity score matching. Age, gender, socioeconomic status, service settings, district of residence, proportion of days covered reflecting medication adherence, and the number of comorbidities were adjusted. From 217,910 eligible patients, 9500 (4.4%) died from cancer within five years after their first-ever antihypertensive prescription. Most cancer deaths occurred in the digestive (38.9%) and respiratory system (30.4%); the breast (6.2%); and the lympho-hematopoietic tissues (5.3%). The proportion of patients who died from cancer was the highest in the calcium channel blocker (CCB) group (6.5%), followed by thiazide diuretics (4.4%), angiotensin converting enzyme inhibitors (4.2%) and β-blockers (2.6%). When compared with β-blockers, patients prescribed CCBs (Adjusted Hazard Ratio [AHR] = 1.406, 95% C.I. 1.334–1.482, p < 0.001) were more likely to die from cancer. Thiazide users were also more likely to suffer from cancer deaths (AHR = 1.364, 95% C.I. 1.255–1.483, p < 0.001), but became insignificant in stratified analysis. The association between cancer mortality and use of CCB, and perhaps thaizide, may alert physicians to the need for more meticulous and comprehensive care of these patients in clinical practice. We recommend prospective studies to evaluate cause-and-effect relationships of these associations

The effectiveness of metoprolol versus atenolol on prevention of all-cause and cardiovascular mortality in a large Chinese population: a cohort study

Background: Existing trials almost exclusively used atenolol to represent the entire β-blocker class, and it is unknown whether there are intra-class differences. We compared the incidence of all-cause and cardiovascular mortality, blood pressure (BP) control and adherence levels between patients newly prescribed atenolol vs. metoprolol tartrate. Methods: This cohort study included all public, clinical settings in Hong Kong between 2001 and 2005, followed up till 2010. We compared outcomes between 22,479 new atenolol users and 29,972 new metoprolol tartrate users. Cox proportional hazard regression analysis was used to evaluate the difference in mortality between drugs. Binary logistic regression analyses were used to compare the BP control rates and adherence levels. Results: 7.0% and 13.1% died of any causes among atenolol and metoprolol users, respectively (p < 0.005). The incidence of cardiovascular mortality among atenolol users was lower than metoprolol users (1.4% vs. 3.7%, p < 0.001). When compared with atenolol users, metoprolol users were 1.13-fold (95% C.I. 1.06–1.20) and 1.56-fold (95% C.I. 1.27–1.90), respectively, more likely to experience all-cause and cardiovascular mortality; less likely to be drug adherent (adjusted relative risk [aRR]: 0.95, 95% C.I. 0.90–0.99, p = 0.013); and less likely to achieve optimal overall BP control (aRR 0.94, 95% C.I. 0.90–0.99, p = 0.023) and diastolic BP control (aRR 0.86, 95% C.I. 0.77–0.97, p = 0.013). Conclusions: These findings imply an intra-class difference for beta-blockers when used as first-line antihypertensive prescriptions in real-life clinical settings which inform future clinical guidelines. More outcome studies on the effectiveness of different subtypes within other major antihypertensive drug classes are warranted

Neural-network accelerated coupled core-pedestal simulations with self-consistent transport of impurities and compatible with ITER IMAS

An integrated modeling workflow capable of finding the steady-state plasma solution with self-consistent core transport, pedestal structure, current profile, and plasma equilibrium physics has been developed and tested against a DIII-D discharge. Key features of the achieved core-pedestal coupled workflow are its ability to account for the transport of impurities in the plasma self-consistently, as well as its use of machine learning accelerated models for the pedestal structure and for the turbulent transport physics. Notably, the coupled workflow is implemented within the One Modeling Framework for Integrated Tasks (OMFIT) framework, and makes use of the ITER integrated modeling and analysis suite data structure for exchanging data among the physics codes that are involved in the simulations. Such technical advance has been facilitated by the development of a new numerical library named ordered multidimensional arrays structure.</p