Turbulence is commonly observed in nearly collisionless heliospheric plasmas, including the solar wind and corona and the Earth’s magnetosphere. Understanding the collisionless mechanisms responsible for the energy transfer from the turbulent fluctuations to the particles is a frontier in kinetic turbulence research. Collisionless energy transfer from the turbulence to the particles can take place reversibly, resulting in non-thermal energy in the particle velocity distribution functions (VDFs) before eventual collisional thermalization is realized. Exploiting the information contained in the fluctuations in the VDFs is valuable. Here we apply a recently developed method based on VDFs, the field–particle correlation technique, to a $\unicode[STIX]{x1D6FD}=1$, solar-wind-like, low-frequency Alfvénic turbulence simulation with well-resolved phase space to identify the field–particle energy transfer in velocity space. The field–particle correlations reveal that the energy transfer, mediated by the parallel electric field, results in significant structuring of the VDF in the direction parallel to the magnetic field. Fourier modes representing the length scales between the ion and electron gyroradii show that energy transfer is resonant in nature, localized in velocity space to the Landau resonances for each Fourier mode. The energy transfer closely follows the Landau resonant velocities with varying perpendicular wavenumber $k_{\bot }$ and plasma $\unicode[STIX]{x1D6FD}$. This resonant signature, consistent with Landau damping, is observed in all diagnosed Fourier modes that cover the dissipation range of the simulation.

The purpose of the study was to determine the incidence of cardiovascular disease (CVD) among people living with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (PLWHA) in Taiwan. PLWHA were identified from the Taiwan Centers for Disease Control HIV Surveillance System between 2000 and 2014. To examine the effect of active antiretroviral therapy (HAART) on CVD incidence, incidence densities and standardised incidence rates (SIRs) of CVD were calculated after stratifying PLWHA by HAART. Of 26 272 PLWHA (mean age, 32.3 years) identified, 73.4% received HAART. Compared with general population, SIRs (95% confidence interval) were higher for incident coronary artery disease (1.11 (1.04–1.19)), percutaneous coronary intervention (1.32 (1.18–1.47)), coronary artery bypass surgery (1.47 (1.29–1.66)), sudden cardiac death (3.01 (2.39–3.73)), heart failure (1.50 (1.31–1.70)) and chronic kidney disease (1.95 (1.81–2.10)), but was lower for incident atrial fibrillation (0.53 (0.37–0.73)). Considering the effect of HAART on incident CVD, the SIRs for all-cause, ischaemic and haemorrhagic stroke were higher in PLWHA who did not receive HAART, but were lower in PLWHA who received HAART. PLWHA had higher risks of incident coronary artery disease, percutaneous coronary intervention, coronary artery bypass surgery, sudden cardiac death, heart failure and chronic kidney disease. HAART reduces risks of incident CVD in PLWHA.

This study presents a polymerization of L-lactide and poly(ethylene glycol) of various molecular weights to produce biodegradable poly(L-lactide)-poly(ethylene glycol) (L-PEG) block copolymers. The chemical structures, crystallization behavior and thermal properties of L-PEG copolymers were investigated using proton nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, gel permeation chromatography, thermogravimetric analysis and differential scanning calorimetry (DSC). The analysis of isothermal crystallization behavior of L-PEG copolymers using the Avrami equation revealed that the grain growth of L-PEG200 and 600 were unstable, jumping between one dimension and two dimensions. By contrast, the grain growth of L-PEG2000 was more stable, with a growth trend toward three dimensions. The results of L-PEG isothermal crystallization by DSC indicate that within a range of 123–127 °C, the crystallization rate was higher at lower temperatures. The values of the crystallization constants in the Avrami equation were also lower.

Little is known about the biological effect of folate in the protection against mitochondrial (mt) oxidative decay. The objective of the present study was to examine the consequence of folate deprivation on mt oxidative degeneration, and the mechanistic link underlying the relationship. Male Wistar rats were fed with an amino acid-defined diet containing either 8 (control) or 0 (folate-deficient, FD) mg folic acid/kg diet. After a 4-week FD feeding period, significant elevation in oxidative stress was observed inside the liver mitochondria with a 77 % decrease in mt folate level (P < 0·001), a 28 % reduction in glutathione peroxidase activity (P = 0·0333), a 1·2-fold increase of mt protein carbonyls (P = 0·0278) and an accumulated 4834 bp large-scale deletion in mtDNA. The elicited oxidative injuries in FD liver mitochondria were associated with 30 % reduction of cytochrome c oxidase (CcOX) activity (P = 0·0264). The defective CcOX activity in FD hepatocytes coincided with mt membrane potential dissipation and intracellular superoxide elevation. Exposure of FD hepatocytes to pro-oxidant challenge (32 μm-copper sulphate for 48 h) led to a further loss in CcOX activity and mt membrane potential with a simultaneous increase in superoxide production. Preincubation of pro-oxidant-treated FD hepatocytes with supplemental folic acid (10–1000 μm) reversed the mt oxidative defects described earlier and diminished superoxide overproduction. Increased supplemented levels of folic acid strongly correlated with decreased lipid peroxidation (γ − 0·824, P = 0·0001) and protein oxidative injuries (γ − 0·865, P = 0·0001) in pro-oxidant-challenged FD liver mitochondria. Taken together, the results demonstrated that folate deprivation induces oxidative stress in liver mitochondria, which is associated with CcOX dysfunction, membrane depolarization and superoxide overproduction. The antioxidant activity of supplemental folic acid may partially, if not fully, contribute to the amelioration of pro-oxidant-elicited mt oxidative decay.

This study presents the mechanical and electrical properties (including elastic modulus, yield strength and electrical resistance) of PDMS/CNTs nanocomposites. The elastic modulus and yield strength were determined from tensile tests. In addition, a high resistance meter was used to measure the electrical resistances of the PDMS/CNTs nanocomposites. The test specimens of nanocomposites were manufactured using the thermoforming method. There were two recipes used during the thermoforming process: 100 °C for 1 hour, and 150 °C for 15 minutes. The mixtures of PDMS and CNTs were stirred by ultrasonic instrument to prevent polymerization. A feeler gap was used to define the thickness of the specimens. Therefore, the thickness could be controlled within the range of ∼100 μm. Four different kinds of specimens were investigated, including pure PDMS, 1.0 wt%, 2.0 wt% and 4.0 wt% CNTs polymeric composites. As for the l00°C recipe, the elastic modulus of pure PDMS, 1.0 wt%, 2.0 wt%, and 4.0 wt% CNTs were 1.05MPa, 1.17MPa, 1.10MPa and 1.35MPa, respectively. A for the l50°C recipe, the elastic modulus of pure PDMS, 1.0 wt%, 2.0 wt% and 4.0 wt% CNTs were 1.32MPa, 1.42MPa, 1.43MPa, and 1.54MPa. The differences of electrical resistance of PDMS/CNTs nanocomposites at two different conditions and the microstructures composed of the mixtures are also described in this article.

In this paper certain relations between non-compact transformation groups and compact transformation groups are studied. The notion of re-ducibility and separability of transformation groups is introduced, several necessary and sufficient conditions are established: (1) A separable transformation group to be locally weakly almost periodic, (2) A reducible and separable transformation group to be a minimal set and (3) A reducible and separable transformation group to be a fibre bundle. As applications we show, among other things, that (1) for certain reducible transformation groups its fundamental group is not trivial which is a generalization of a result in [4].