(S)-1-Hydroxy­propan-2-aminium (2R,3R)-3-carb­oxy-2,3-dihydroxy­propanoate monohydrate

The chiral title compound, C4H10NO+·C4H5O6 −·H2O, is a hydrated mol­ecular salt in which the tartaric acid has transferred one proton to the (S)-2-amino­propan-1-ol mol­ecule. The crystal structure is stabilized by a three-dimensional network of N—H⋯O and O—H⋯O hydrogen bonds. The absolute configuration was assigned on the basis of the starting materials

Influence of Lanthanum-Doped Tungsten Wire Drawing Process on Microstructure and Properties

A reasonable preparation processing of Lanthanum-doped tungsten wire plays a decisive role in the final properties of the wire. This paper gives the optimum drawing process parameters of lanthanum-doped tungsten wire with φ1.00 mm–φ0.50 mm and explains the phenomenon of coarsening of fiber-like grains in the preparation processing of tungsten wire. The final optimum process parameters of lanthanum-doped tungsten wire are given: the temperature is 950 °C (the first pass temperature is 950 °C, and the temperature decreases by about 20 °C for each pass), the compression ratio is 15%, mold temperature is 550 °C, because of the limitation of equipment conditions, the wire drawing speed is fixed at 0.19 m/s. It is found that the fiber-like grains of the tungsten wire coarsen when the temperature is too high, and it is prone to breakage when the temperature is too low during the drawing process. When the compression ratio is too high (for example, 22%), there is a negative impact on the surface quality and the straightness of the tungsten wire. When the compression ratio is too low, the processing die time is increased, and the production cost is increased

In Situ Ternary Boride: Effects on Densification Process and Mechanical Properties of WC-Co Composite Coating

New coatings resistant to corrosion in high-temperature molten zinc aluminum were prepared by supersonic flame spraying of various composite powders. These composite powders were prepared by mixing, granulation, and heat treatment of various proportions of Mo–B4C powder and WC and Co powder. X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), high-angle annular dark-field scanning transmission electron microscopy (HAADF–STEM), energy dispersive X-ray spectroscopy (EDS), and mechanical analysis were used to study the effects of Mo–B4C on the microstructure, phase, porosity, bonding strength, and elastic modulus of the composite powder and coating. Results show that the addition of an appropriate quantity of Mo–B4C reacts with Co to form ternary borides CoMo2B2 and CoMoB. Ternary boride forms a perfect continuous interface, improving the mechanical properties and corrosion resistance property of the coating. When the amount of Mo–B4C added was 35.2%, the mechanical properties of the prepared coating reached optimal values: minimum porosity of 0.31 ± 0.15%, coating bonding strength of 77.81 ± 1.77 MPa, nanoindentation hardness of 20.12 ± 1.85 GPa, Young’s modulus of 281.52 ± 30.22 GPa, and fracture toughness of 6.38 ± 0.45 MPa·m1/2

Microstructure and tribological performance of Cr7C3-(Ni,Cr)3(AI,Cr) coating deposited from Cr7C3 in-situ synthesized alloy powder

The work is aimed at developing a new type of Cr7C3-(Ni,Cr)3(AI,Cr) coatings for parts used in heavy-duty diesel engine. The feedstock, in which the stripe shaped Cr7C3 was in-situ synthesized, was firstly prepared by vacuum melting and gas atomization, then it was subjected to high velocity oxy-fuel(HVOF) spraying to deposited coating.The element composition, microstructures and the phase composition of the powder, as well as the sprayed coating were analyzed by chemical analysis, SEM and XRD. The hardness and sliding wear performance of the sprayed coating was also tested and compared to a commercial Cr3C2-NiCr coating used on piston ring.The results showed that the content of carbon in feedstock was almost the same as it was designed, and the volume content of Cr7C3 was increased with the more carbon and chromium added. The phases of the sprayed coating was also mainly the Cr7C3 and the Cr doped Ni3AI, and the ratio of them was almost similar to it in the powder. With the increased content of Cr7C3 in coating, the microhardness at room temprature was firstly increased to about 1000Hv0.3, but then minor decreased. When the temprature rised to 700\ub0C, the microhardness of the coating was almost no changed, which showed its potential application at the high temprature.The coating involved 70vol.% and 77 vol.%Cr7C3 was showed the improved wear resisrance, lower friction coefficient and better compatibility to contourpartthan other Cr7C3-(Ni,Cr)3(AI,Cr) coatings and Cr3C2-NiCr coating

Author Correction: Improved ethanol electrooxidation performance by shortening Pd-Ni active site distance in Pd-Ni-P nanocatalysts.

An amendment to this paper has been published and can be accessed via a link at the top of the paper

Distinct associations between hypertension and obstructive sleep apnea in male and female patients.

Obstructive sleep apnea (OSA) is highly associated with hypertension. However, the correlation between hypertension and OSA at different levels of severity and the influence of gender on that correlation are unclear. A total of 996 patients (776 males and 190 females) with OSA were recruited. The influence of gender on the correlation between hypertension and OSA at different stratifications of severity, based on the apnea-hypopnea index (AHI), was fully evaluated together with the major health risk factors obesity, age, and diabetes. Females with OSA were significantly older on average than males with OSA. Moreover, females had milder degrees of OSA on average than the extent of severity seen in males. The proportion of females with diabetes or hypertension was higher than that of males. The proportion of males with hypertension and obesity increased significantly with OSA, and age also increased with OSA. The percentage of females with hypertension at different degrees of OSA severity was stable at about 26% in the mild, moderate, and severe OSA groups. Among females, age was increased significantly in the moderate relative to the mild OSA group. Moreover, the proportion of obese subjects was increased significantly in the severe compared with the moderate OSA group. The proportions of males and females with diabetes were not significantly different among all OSA severity groups. An ordinal multivariate logistic regression analysis confirmed that hypertension, age, and obesity were associated with OSA severity in males, whereas only age and obesity were associated with OSA severity in females. Although the proportion of subjects with hypertension was higher in females with OSA than in males with OSA, the proportion of subjects with hypertension increased as the severity of OSA increased in males but not in females

Characterization and phylogenetic analysis of the chloroplast genome of <i>Duhaldea cappa</i> (Buch.-Ham. ex D.Don) Pruski & Anderb. (Asteraceae)

Duhaldea cappa, a valuable medicinal plant of genus Duhaldea in the tribe Inuleae, is predominantly found in China, Bhutan, India, Malaysia, Nepal, Pakistan, Thailand, and Vietnam. However, the genomic studies of Duhaldea cappa are limited. In this study, we successfully sequenced and assembled the complete chloroplast genome of Duhaldea cappa. The chloroplast genome is 150,819 bp in length with a 37.73% GC content. The chloroplast genome has a quadripartite structure, consisting of a large single-copy region of 82,731 bp, a small single-copy region of 18,168 bp, and a pair of inverted repeat sequences of 24,960 bp. The genome contains 133 genes. Among these genes, there are 88 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The phylogeny reconstructed from data of the complete chloroplast genome indicated that Duhaldea cappa is closely related to Pluchea indica in the tribe Inuleae. Analyzing and reporting the chloroplast genome of Duhaldea cappa will establish a solid theoretical and data foundation for the efficient development, conservation, and utilization of this plant species.</p

Baseline data from the male patients.

<p>Skewed data are presented as medians (interquartile range); categorical data are presented as percentages. All ages are shown in years. Differences in baseline characteristics among the groups were examined using the Kruskal-Wallis H test, one-way ANOVA, Fisher's exact test, or χ2 test, according to the data distribution characteristics. AHI, apnea-hypopnea index.</p><p>Baseline data from the male patients.</p

Adjusted odds ratios (ORs) relating OSA severity to various risk factors.

<p>ORs (95% CIs), adjusted for each covariate for the effects of other covariates, were evaluated by ordinal logistic regression modeling.</p><p>Adjusted odds ratios (ORs) relating OSA severity to various risk factors.</p