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• Yak milk, a staple food in high altitude central Asia, is uniquely rich in branched chain fatty acids. • Yak half lactation stage milkfat is richer in branched fats, reaching 5.3% of fatty acids. • Intake of branched fat in high yak milk consumers can be multiple grams per day, the highest in the world. Branched chain fatty acids (BCFA) are bioactive food compounds and are well known to be essential components of human, cow and caprine milk. In Qinghai-Tibet plateau, yaks are domesticated in large numbers and their milk in addition to meat are commercially important to millions of Tibetans and Chinese. We tested the hypotheses that concentrations of BCFA in yak milk and manure differ between lactation periods and evaluated gene expression levels of certain genes involved in the biosynthesis and elongation of fatty acids. Fresh milk and manure were collected from each yak and their fatty acid compositions compared with emphasis on BCFA. Yak milk and manure samples from the full lactation (October, 2015) and half lactation periods (March, 2016) were collected and BCFA levels were analyzed in detail by GC-FID and structures verified by GC-EI-MS/MS. Gene expression studies were carried out by semi-quantitative real time PCR method. The difference between full lactation and half lactation was tested using student's t -test. Linear regression model was modelled in Excel and its significance was tested by ANOVA. Statistical significance was determined by performing student's t -test for gene expression studies. BCFA ranged from 3–6% of total fatty acids in yak milk samples. The half-lactation yak milk contained higher levels of BCFA (5.29 ± 0.53) than the full-lactation milk (4.00 ± 0.46). The total BCFA in yak manure was found to be 14.67 ± 1.21, high in anteiso- 15:0 and anteiso- 17:0. ELOVL1 enzyme involved in the elongation of saturated C18 to C26 acyl-CoA substrates and MCAT enzyme involved in the transfer of a malonyl group to the mitochondrial acyl carrier protein are significantly upregulated in full-lactation milk. BCFA in yak manure especially anteiso BCFA are positively correlated with yak milk from the same animal, indicating that these BCFA come from dietary sources. Yak milk delivers 777 mg BCFA compared to 158 mg per cup of whole U.S. dairy milk. QTP herders known to consume up to 2 kg of yak yogurt take in an estimated 3,500–5,000 mg BCFA per day. We conclude that BCFA intake for yak milk consumers is among the highest known in the world, higher when drawn from half lactating yaks. [ABSTRACT FROM AUTHOR]

Lithium metasilicate and disilicate glass-ceramics (LMGC and LDGC) are attractive dental materials but poor surface quality produced in current milling/grinding is a technical bottleneck. This paper reports on the microgrinding characteristics and mechanisms of LMGC and LDGC using micro-pencil diamond tools at different conditions. Surface quality was assessed using 3D laser confocal microscopy in terms of comprehensive roughness parameters. A combination of brittle and localized ductile removal mixture and brittle fracture was featured on the microground LMCG and LDGC surfaces identified through microscopic examination. The generation of brittle and localized ductile areas significantly depended on the diamond grit size and the depth of cut, resulting in different surface asperities. Better surface quality was achieved with reduced diamond grit size and depth of cut. The nanoscale maximum grit cutting depth in microginding achieved the best average and maximum roughness values of 0.241 ± 0.009 μm and 4.380 ± 0.861 μm for LMGC with approximately 80% and 60% reductions in comparison with dental CAD/CAM milling, respectively. Microgrinding of LDGC also achieved the best average and maximum roughness values of 0.168 ± 0.013 μm and 3.693 ± 0.467 μm with more than 90% improvement compared with simulated conventional grinding, simplifying the manufacturing procedure for LDGC restorations. Microgrinding also produced the kurtosis and skewness for both materials comparable to human teeth. More diamond tool wear occurred in microgrinding of high-strength LDGC than low-strength LMGC. Although microgrinding of multiphase LMCG and LDGC in ductile regime can be challenging due to microstructural diversity, the technique can advance current CAD/CAM milling/grinding for high-quality shaping of high-strength ceramic restorations. [Display omitted] • The microgrinding mechanisms of lithium metasilicate/disilicate glass-ceramics (LMGC and LDGC) were elucidated. • A combination of brittle and localized ductile removal mixture and brittle fracture was dominant in microgrinding of multi-phase ceramics. • Microstructures, mechanical properties and microgrinding conditions remarkably influenced removal mechanisms and quality. • Microgrinding of LMGC and LDGC achieved huge reductions in roughness and comparable kurtosis and skewness to human teeth. • Microgrinding may advance dental CAD/CAM milling techniques and simplify the prodcution of high-strength ceramic restorations. [ABSTRACT FROM AUTHOR]

• Depositing catalysts on hydrogen gas-transfer membranes in-situ created a homogeneous bimetallic layer. • Bimetallic palladium plus indium nanoscale films on hydrogen gas-transfer membranes enabled nitrate reduction. • Nanocatalyst oxidation must be avoided to retain nitrate removal activity. • Irreversible nanocatalyst attachment was necessary for sustained nitrate removal. Catalytic hydrogenation of nitrate in water has been studied primarily using nanoparticle slurries with constant hydrogen-gas (H 2) bubbling. Such slurry reactors are impractical in full-scale water treatment applications because 1) unattached catalysts are difficult to be recycled/reused and 2) gas bubbling is inefficient for delivering H 2. Membrane Catalyst-film Reactors (MCfR) resolve these limitations by depositing nanocatalysts on the exterior of gas-permeable hollow-fiber membranes that deliver H 2 directly to the catalyst-film. The goal of this study was to compare the technical feasibility and benefits of various methods for attaching bimetallic palladium/indium (Pd/In) nanocatalysts for nitrate reduction in water, and subsequently select the most effective method. Four Pd/In deposition methods were evaluated for effectiveness in achieving durable nanocatalyst immobilization on the membranes and repeatable nitrate-reduction activity: (1) In-Situ MCfR-H 2 , (2) In-Situ Flask-Synthesis, (3) Ex-Situ Aerosol Impaction-Driven Assembly, and (4) Ex-Situ Electrostatic. Although all four deposition methods achieved catalyst-films that reduced nitrate in solution (≥ 1.1 min−1gPd−1), three deposition methods resulted in significant palladium loss (>29%) and an accompanying decline in nitrate reactivity over time. In contrast, the In-Situ MCfR-H 2 deposition method had negligible Pd loss and remained active for nitrate reduction over multiple operational cycles. Therefore, In-Situ MCfR-H 2 emerged as the superior deposition method and can be utilized to optimize catalyst attachment, nitrate-reduction, and N 2 selectivity in future studies with more complex water matrices, longer treatment cycles, and larger reactors. [ABSTRACT FROM AUTHOR]

• Mechanical stress fields during micro-/nano- machining were integrated for surface integrity. • Flexible nanoscale-bonding and hydrodynamic pressure restrains cutting stress and tool vibration. • It decreases roughness, residual stress and SSD to polished ones in micro-shape diamond grinding. • The machined residual stress related to metal elastic modulus is more greatly improved with larger hardness. The micron-scale fixed-abrasive machining can assure micro-shape accuracy through mechanical cut removal and copying, but the machined surface integrity depends on the nanoscale loose-abrasive machining without mechanical stress concentration. Hence, the mechanical stress fields are synthesized by the hybrid machining of loose-Al 2 O 3 -abrasive machining and fixed-diamond-abrasive machining. The objective is to improve the surface integrity in the mechanical machining of difficult-to-cut metals. In order to hold the loose-abrasive in fixed-abrasive mechanical machining, the bonding behaviour and the hydrodynamic pressure were first analysed in relation to flow viscosity and fixed-abrasive-tool rotation, respectively. In the hybrid machining, the surface formation was then modelled in relation to mechanical stress distribution, fixed-abrasive-tool vibration, hydrodynamic pressure, etc. Finally, the surface integrity was investigated in micro-machining of die steel, titanium alloy and Inconel alloy, respectively. It is shown that the nanoscale hydrated particle cluster flexibly bonds the loose-abrasive with the hydrodynamic pressure beyond the critical tool rotation. It can absorb the micron-scale tool vibration to the surface formation, fixed-abrasive wear without ground traces and micro-cut edge burrs. The resulted homogeneous stress also can restrain the uneven residual stress derived from the cut copying of fixed-abrasive machining. The hybrid machining decreases the subsurface damage (SSD), residual compressive stress and surface roughness to the polishing ones in micro-shape grinding, but it is subject to the nanometre-scale size of loose-abrasive, the hydrodynamic pressure and the micron-scale cutting depth of fixed-abrasive. The fixed-abrasive wear rate is higher with larger metal hardness, and the residual stress associated with elastic modulus is more greatly improved. As a result, die steel shows better machinability with a low fixed-abrasive wear rate and residual stress compared to titanium alloy and Inconel alloy. [Display omitted] [ABSTRACT FROM AUTHOR]