Search

In order to explore the optimal extraction conditions of saponins from quinoa (Longli No.1) grains and to verify their tyrosinase inhibitory activity, three factors and three levels orthogonal experiments were designed to explore the optimum extraction conditions of the ratio of material to solution, ethanol concentration and ultrasonic time. L-dopa induced B16 cell model was established and the effects of quinoa saponin on cell activity and tyrosinase activity were measured. Finally, Western blot was used to explore the pathway of quinoa saponins affecting the activity of tyrosinase. The results showed that the best extraction conditions for quinoa saponins were 1:40 ratio of material to liquid, 70% ethanol under ultrasound for 60 min, and the yield was 17.85±0.88 mg/g. When the concentration of quinoa saponin was lower than 200 µg/mL, it had no significant inhibitory effect on B16 cells, but could significantly inhibit tyrosinase activity and melanin formation. When B16 cells were treated with 200 µg/mL chenopodin for 72 h, the relative content of melanin decreased to 73.85%, and the activity of tyrosinase decreased to 53.31%. Quinoa saponins inhibited the formation of melanin by inhibiting the expression of microphtalmia-associated transcription factor (MITF) and tyrosinase (TYR) proteins. Quinoa saponins can be used in cosmetics or medicines as a component with whitening activity. [ABSTRACT FROM AUTHOR]

Blending effect of color blended yarns, which plays a critical important role to the fabrics styles, is affected by yarn structure, spinning processes, and blending methods. In this study, color blended viscose yarns were produced by compact ring spinning, rotor spinning and air-jet vortex spinning with single-passage and three-passage color-blended slivers. The blending effect of these yarns was evaluated by Hamilton transfer index. Additionally, yarn performance was tested, compared and analyzed, including strength, hairiness and evenness. Results show that the blending effect of the rotor spun yarns is the best with both types of slivers. Even though such yarns have wrap fibers on the surface like the air-jet vortex yarns, the yarn structures are different. Compared to the tightly wrapped fiber on the rotor-spun yarns, wrapped fibers form a shield on core fibers of the air-jet vortex yarns. Among the three types of yarns, compact ring yarns have higher mean value of evenness and its value also changes with the passage number of sliver, yarn linear density and the spinning method. Hairiness of air-jet vortex yarn is the lowest, followed by rotor spun yarn and then the compact ring-spinning yarn. While physical performance such as tenacity, breaking elongation, and break work of compact-ring-spinning yarns are the greatest among the three types of yarns. [ABSTRACT FROM AUTHOR]

Clinopyroxene is a common phase in a variety of hydrothermal ore deposits, notably in skarn deposits where it typically occurs as a major constituent. It commonly displays variations in texture and composition due to changing physicochemical conditions and contains relatively high concentrations of rare earth elements (REEs), making it an important petrogenetic indicator. In this study, we integrate textural and geochemical investigations of clinopyroxene from the Baijian Fe skarn deposit (eastern China) to constrain the evolution of ore-forming fluids and provide significant new insights into partitioning of REEs between the clinopyroxene and hydrothermal fluids. In the Baijian Fe skarn, endoskarn clinopyroxene is typically zoned with homogeneous Fe-poor cores and oscillatory zoned Fe-rich rims. The rims are also enriched in Na, Co, Ni, and V and contain primary fluid inclusions with high salinities of 57.7–61.2 wt.% NaCl equiv. The compositional differences between the cores and rims reflect a transition from dilute, Fe-poor fluids to saline, Fe-rich components, likely a result of fluid boiling. In the exoskarn, early formed Fe-poor clinopyroxene is commonly replaced with Fe-rich clinopyroxene through fluid-assisted, coupled dissolution-reprecipitation processes. Overall, the textural features and compositional variations of clinopyroxene reflect a transition from early diffusive metasomatism by low-salinity fluids under low water/rock ratios to later advective metasomatism by high-salinity fluids under high water/rock ratios. When normalized to the modeled composition of the melt-equilibrated fluid, the log light REE and middle REE abundances in the clinopyroxene fit a linear function of the radius parameter (expressed as r 0 /2 × (r i − r 0)2 + 1/3×(r i − r 0)3) of the lattice strain model, indicating that crystal lattice strain has exerted a major control on REE clinopyroxene-fluid partitioning. Cores of zoned endoskarn clinopyroxenes show an upward increase in heavy REE (HREE) from Ho to Lu, likely caused by incorporation of those elements both into the eightfold M2 site and the sixfold M1 site of clinopyroxene. The increasing HREE compatibility coincides with elevated Mn contents in the cores of the clinopyroxene grains, implying that Mn has a significant effect on the accommodation of HREE into the sixfold M1 site of clinopyroxene, presumably due to the similar ionic radius between Mn2+ in sixfold coordination (Mn2+ = 0.83 Å) and the HREE (e.g., Lu3+ = 0.861 Å). [ABSTRACT FROM AUTHOR]

This paper has designed an anchor point lever beam coupled tuning fork micro-gyroscope and tested its output performance. The tuning fork micro-gyro is designed to eliminate the output error caused by orthogonal coupling and in-phase-inverting coupling by structural decoupling and electrical decoupling, and can improve the anti-vibration performance and the modal optimization ability. It has derived the dynamic response working model of the non-ideal tuning fork micro-gyroscope, and optimized the structural parameters of the micro-gyroscope by simulation analysis. The microstructure processing has been realized by the SOI-MEMS process, sealed the processed structural prototype, and tested the performance through the established experimental system. According to the test results, the designed micro-gyroscope driving direction has greatly reduced the in-phase-inverting coupling through the anchor coupling lever beam, and the detection direction effectively suppressed the in-phase-inverting coupling through the stiffness matching electrode. While closed-loop detecting, the measured Aallan variance zero-bias stability is 1.779°/h, and the 1σ zero-bias stability is 8.3°/h. While applying a stiffness matching voltage, the measured vibration sensitivity is 23.9°/h/g. [ABSTRACT FROM AUTHOR]

Background: China is facing challenges of the shifting presentation of tuberculosis (TB) from younger to elderly due to an ageing population, longer life expectancy and reactivation disease. However, the burden of elderly TB and influence factors are not yet clear. To fill the gap, we generated a cohort study to measure the magnitude of TB incidence and associated factors among the elderly population aged 65 years and above in China. Methods: In this cohort established in 2013 through a prevalence survey conducted in selected sites, a total of 34 076 elderlies without TB were enrolled into two-year follow-up. We used both active and passive case findings to find out all TB patients among them. The person-year (PY) incidence rates for both bacteriologically positive TB and active TB were calculated. Cox proportional regression model was performed to test effect of risk factors, and the population attributable fraction (PAF) of each risk factor contributing to incident TB among elderlies was calculated. Results: Over the two-year follow-up period, a total of 215 incident active TB were identified, 62 of which were bacteriologically positive. The incidence rates for active TB and bacteriologically positive TB were 481.8 per 100 000 PY (95% CI: 417.4–546.2 per 100 000 PY) and 138.9 per 100 000 PY (95% CI: 104.4–173.5 per 100 000 PY), respectively. Incident cases detected by active case finding were significantly higher (P < 0.001). Male, non-Han nationality, previously treated TB, ex/current smoker and body mass index (BMI) < 18.5 presented as independent predictors for developing TB disease. For developing bacteriologically positive TB, the biggest contribution was from self-reported ex or current smoker (18.06%). And, for developing active TB, the biggest contribution was from non-Han nationality (35.40%), followed by male (26.80%) and age at 75 years and above (10.85%). Conclusions: Ageing population in China had a high TB incidence rate and risk to develop TB disease, implying that National TB Program (NTP) needs to prioritize for elderly. Active case finding should be applied capture more active TB cases among this particular population, especially for male, non-Han nationality, and those with identified risk factors. [ABSTRACT FROM AUTHOR]