Assessment of the electron-proton energy relaxation rates extracted from molecular dynamics simulations in weakly-coupled hydrogen plasmas.

Electron-proton energy relaxation rates are assessed using molecular dynamics (MD) simulations in weakly-coupled hydrogen plasmas. To this end, we use various approaches to extract the energy relaxation rate from MD-simulated temperatures, and we find that existing extracting approaches may yield results with a sizable discrepancy larger than the variance between analytical models, which is further verified by well-known case studies. Present results show that two of the extracting approaches can produce identical results, which is attributed to a proper treatment of relaxation evolution. To discriminate the use of various methods, an empirical criterion with respect to initial plasma temperatures is proposed, which can self-consistently explain the cases considered. In addition, for a transient electron-proton plasma, we show that it is possible to extrapolate the Coulomb logarithm from that derived by initial plasma parameters in a single MD calculation, which is reasonably consistent with previous MD data. Our results are helpful to obtain accurate MD-based energy relaxation rates.

[Brief study on processing characteristics of first batch of classical prescriptions and suggestions on textual research].

As an important treasure for the research and development of new Chinese medicines, the classical prescriptions have a long medical history in China and are the summary of the clinical experience of the medical experts in the past dynasties. To support the research and development of classical prescriptions,relevant encouraging policies were issued by the state and relevant administrative departments. It is one of the key problems in the development process of classical prescriptions to verify and determine the processing methods of prescription herbal drugs. At present, there is no consensus or standard on such problems of classical prescriptions. In this paper, we sorted out and analyzed the related content of the herb processing for classical prescriptions, summarized the characteristics of the processing methods in the Catalogue of classical prescriptions(First Batch) and the problems faced in the textual research, and put forward some suggestions on the processing and textual research, including four research strategies: sorting out the mainstream methods for herbs in various periods of classical prescriptions, clarifying histological changes in the processing methods, determining the processing methods based on the drug processing characteristics, determining the processing methods based on the processing functions and identifying the processing methods according to the clinical efficacy and indication, so as to provide ideas and references for the research of processing methods involved in classical prescriptions.

Speckle tracking echocardiography assessment of global and regional contraction dysfunction in the mice model of pressure overload.

Speckle tracking echocardiography (STE) has been applied to the evaluation of cardiac contraction dysfunction. However, there were few studies on alteration of global and regional STE parameters in the process of myocardial hypertrophy and heart failure. In this study, STE was applied to evaluate the global and regional cardiac function under heart failure and hypertrophy in the mice model of pressure overload. Adult mice were subjected to mild or severe aortic banding with a 25 Gauge (G) or 27 G needle. After surgery, STE and conventional echocardiography were used in the sham group (n=10), mild trans-aortic banding (TAB) group (n=14) and severe TAB group (n=10) for 8 weeks. The results showed that the mice subjected to severe TAB showed a significant change in fractional shortening (FS), left ventricular (LV) mass, and left ventricular end diastolic diameter (LVEDD) (P<0.05 for each). Meanwhile, there were no significant differences in FS and LVEDD between the sham group and mild TAB group during the experimental procedures (P>0.05 for both). STE analysis revealed that longitudinal strain (LS) was significantly decreased in the severe TAB group as compared with the sham and mild TAB groups (P<0.05 for both) from the postoperative week 1. LS in the mild TAB group was reduced as compared to the sham group (P<0.05). Radial strain (RS) and circumferential strain (CS) were significantly decreased in the severe TAB group as compared to the sham group and the mild TAB group (P<0.05 for both) from the postoperative week 1 (P<0.05 for both). Compared to the sham group, CS in the mild TAB group maintained unchanged during the test period, and RS was reduced only on the postoperative week 6 (P<0.05). Finally, regional contraction dysfunction was analyzed in both hypertrophic and failing myocardium in longitudinal and radial directions. It was found that LS was largest in the apex region and RS was smallest in the apex region in the healthy and hypertrophic myocardium. It was also found that compared to the sham group, only base longitudinal strain in the mild TAB group was decreased. Each of regional strain in the severe TAB group was uniformly depressed in radial and longitudinal directions. It is concluded that STE has provided a non-invasive and highly feasible way to explore the global and regional contraction dysfunction in hypertrophic and heart failure myocardium in the murine model of pressure overload.

Ability of ambulatory ECG-based T-wave alternans to modify risk assessment of cardiac events: a systematic review.

BACKGROUND: Exercise-based spectral T-wave alternans (TWA) has been proposed as a noninvasive tool-identifying patients at risk of sudden cardiac death (SCD) and cardiac mortality. Prior studies have indicated that ambulatory electrocardiogram (AECG)-based TWA is an important alternative platform to exercise for risk stratification of cardiac events. This study sought to review data regarding 24-hour AECG-based TWA and to discuss its potential role in risk stratification of fatal cardiac events across a series of patient risk profiles. METHODS: Prospective clinical studies of the predictive value of AECG-based TWA obtained with daily activity published between January 1990 and November 2014 were retrieved. Major endpoints included composite endpoint of SCD, cardiac mortality, and severe arrhythmic events. RESULTS: Data were accumulated from 5 studies involving a total of 1,588 patients, including 317 positive and 1,271 negative TWA results. Compared with the negative group, positive group showed increased rates of SCD (hazard ratio [HR]: 7.49, 95% confidence interval [CI]: 2.65 to 21.15), cardiac mortality (HR: 4.75, 95% CI: 0.42 to 53.55), and composite endpoint (SCD, cardiac mortality, and severe arrhythmic events, HR: 5.94, 95% CI: 1.80 to 19.63). For the 4 studies evaluating TWA measured using the modified moving average method, the HR associated with a positive versus negative TWA result was 9.51 (95% CI: 4.99 to 18.11) for the composite endpoint. CONCLUSIONS: The positive group of AECG-based TWA has a nearly six-fold risk of severe outcomes compared with the negative group. Therefore, AECG-based TWA provides an accurate means of predicting fatal cardiac events.

A novel dimeric thymosin beta 4 with enhanced activities accelerates the rate of wound healing.

OBJECTIVE: Thymosin beta 4 (Tß4) is a peptide with 43 amino acids that is critical for repair and remodeling tissues on the skin, eye, heart, and neural system following injury. To fully realize its utility as a treatment for disease caused by injury, the authors constructed a cost-effective novel Tß4 dimer and demonstrated that it was better able to accelerate tissue repair than native Tß4. METHODS: A prokaryotic vector harboring two complete Tß4 genes with a short linker was constructed and expressed in Escherichia coli. A pilot-scale fermentation (10 L) was performed to produce engineered bacteria and the Tß4 dimer was purified by one-step hydrophobic interaction chromatography. The activities of the Tß4 dimer to promote endothelial cell proliferation, migration, and sprouting were assessed by tetramethylbenzidine (methylthiazol tetrazolium), trans-well, scratch, and tube formation assays. The ability to accelerate dermal healing was assessed on rats. RESULTS: After fermentation, the Tß4 dimer accounted for about 30% of all the bacteria proteins. The purity of the Tß4 dimer reached 98% after hydrophobic interaction chromatography purification. An average of 562.4 mg/L Tß4 dimer was acquired using a 10 L fermenter. In each assay, the dimeric Tß4 exhibited enhanced activities compared with native Tß4. Notably, the ability of the dimeric Tß4 to promote cell migration was almost two times higher than that of Tß4. The rate of dermal healing in the dimeric Tß4-treated rats was approximately 1 day faster than with native Tß4-treated rats. CONCLUSION: The dimeric Tß4 exhibited enhanced activity on wound healing than native Tß4, and the purification process was simple and cost-effective. This data could be of significant benefit for the high pain and morbidity associated with chronic wounds disease. A better strategy to develop Tß4 as a treatment for other diseases caused by injuries such as heart attack, neurotrophic keratitis, and multiple sclerosis was also described.

ORACLE INEQUALITIES FOR THE LASSO IN THE COX MODEL.

We study the absolute penalized maximum partial likelihood estimator in sparse, high-dimensional Cox proportional hazards regression models where the number of time-dependent covariates can be larger than the sample size. We establish oracle inequalities based on natural extensions of the compatibility and cone invertibility factors of the Hessian matrix at the true regression coefficients. Similar results based on an extension of the restricted eigenvalue can be also proved by our method. However, the presented oracle inequalities are sharper since the compatibility and cone invertibility factors are always greater than the corresponding restricted eigenvalue. In the Cox regression model, the Hessian matrix is based on time-dependent covariates in censored risk sets, so that the compatibility and cone invertibility factors, and the restricted eigenvalue as well, are random variables even when they are evaluated for the Hessian at the true regression coefficients. Under mild conditions, we prove that these quantities are bounded from below by positive constants for time-dependent covariates, including cases where the number of covariates is of greater order than the sample size. Consequently, the compatibility and cone invertibility factors can be treated as positive constants in our oracle inequalities.