Quasi-static and dynamic compressive tests with a series loading rates were conducted on (Zr0.6336Cu0.1452Ni0.1012Al0.12)97Tm3 bulk amorphous alloy at cryogenic temperature. It is found that ...mechanical properties of the alloy such as yield strength and plasticity are obviously dependent on temperature and strain rate. The plastic strain of the specimens at 298 K and 77 K is 8.4% and 13.7% respectively under quasi-static load with strain rate of 1 × 10−4 s−1. Additionally, the dynamic mechanical properties of amorphous alloys at different strain rates were tested by split Hopkinson pressure bar(SHPB) to unveil the dynamic deformation behaviors at cryogenic temperature of 177 K and 77 K. Compared with the results of quasi-static compression, strain rate softening phenomenon can be observed under dynamic loading, but the compressive strength of specimens increases significantly with the decrease of temperature. Moreover, the specimens have no obvious plastic deformation under dynamic loading. Compared with room temperature, the improvement of quasi-static and dynamic compressive strength of the alloy at cryogenic temperature can be attributed to the strong interatomic binding force between the alloy elements.
•Quasi-static and dynamic deformation behavior of a Zr-based amorphous alloys at cryogenic temperature was compared.•Relationships between fracture mechanism and temperature under different stress states were discussed.•The effect of stress state on the dynamic fracture behavior of Zr-based metallic glass was analyzed.
ABSTRACT We present preliminary results of the quasar survey in the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) first data release (DR1), which includes the pilot survey and ...the first year of the regular survey. There are 3921 quasars reliably identified, among which 1180 are new quasars discovered in the survey. These quasars are at low to median redshifts, with a highest z of 4.83. We compile emission line measurements around the H , Hβ, Mg ii, and C iv regions for the new quasars. The continuum luminosities are inferred from SDSS photometric data with model fitting, as the spectra in DR1 are non-flux-calibrated. We also compile the virial black hole mass estimates, with flags indicating the selection methods, and broad absorption line quasars. The catalog and spectra for these quasars are also available. Of the 3921 quasars, 28% are independently selected with optical-infrared colors, indicating that the method is quite promising for the completeness of the quasar survey. LAMOST DR1 and the ongoing quasar survey will provide valuable data for studies of quasars.
Background
Lactic acid sting test (LAST) is a classical method to identify sensitive skin. However, some subjects with self‐perceived sensitive skin are negative for LAST.
Objective
To determine ...whether LAST scores are associated with specific phenotype of sensitive skin.
Methods
A total of 292 subjects with self‐perceived sensitive skin were enrolled in this study. The Sensitive Scale was used to evaluate the severity of burning, stinging, itching, tautness, erythema and scaling based on 0–10 scale scores. In addition to the assessment of LAST scores, epidermal biophysical properties were measured using an MPA system.
Results
The Sensitive Scale scores of stinging, itching, tautness and scaling were significantly different between the LAST‐positive and ‐negative groups. However, burning and erythema scores did not differ between the LAST‐positive and ‐negative groups. LAST scores were positively correlated with the Sensitive Scale scores for stinging, itching, tautness and scaling, but not for burning and erythema scores. Moreover, LAST scores negatively correlated with stratum corneum hydration, but positively with transepidermal water loss (TEWL) rates.
Conclusions
Lactic acid sting test scores positively correlated with TEWL rates. LAST scores could be used to identify subjects with sensitive skin characterized mainly by stinging and itching, but not those mainly by burning and erythema.
Résumé
Contexte
Le test de la piqûre d'acide lactique (LAST) est une méthode classique pour identifier les peaux sensibles. Cependant, certaines personnes s’évaluant ayant une peau sensible sont négatifs au test LAST.
Objectif
Déterminer si le score du LAST est associé à un phénotype spécifique de peau sensible.
Méthodes
Au total, 292 personnes s’évaluant ayant une peau sensible ont été inclus dans cette étude. L’échelle de sensibilité a été utilisée pour évaluer la sévérité de la brûlure, du picotements, de la démangeaison, de la tension, de l’érythème et des desquamations basée sur une échelle de 0‐10. En plus de l’évaluation du score LAST, les propriétés biophysiques épidermiques ont été mesurées à l'aide d'un système MPA.
Résultats
Les scores de l’échelle de sensibilité pour le picotement, les démangeaisons, la tension et la desquamation étaient significativement différents entre la groupe LAST positif et celle du LAST négatif. Cependant, les scores de la brûlure et de l’érythème n’étaient pas différents entre les deux groupes. Le score LAST était positivement corrélé avec les scores de l’échelle de sensibilité du picotement, des démangeaisons, de la tension et des desquamations, mais pas pour la brûlure et l’érythème. En plus, les scores LAST étaient négativement corrélés avec l'hydratation du stratum corneum, mais positivement corrélés avec le taux de perte en eau transépidermique (TEWL).
Conclusions
Les scores LAST étaient corrélés positivement avec le taux de perte en eau transépidermique. Les scores LAST pourraient être utilisés pour identifier les personnes avec la peau sensible caractérisée principalement le picotement et les démangeaisons, mais pas la brûlure et l’érythème.
Powerful terahertz (THz) radiation is observed from large-scale underdense preplasmas in front of a solid target irradiated obliquely with picosecond relativistic intense laser pulses. The radiation ...covers an extremely broad spectrum with about 70% of its energy located in the high frequency regime over 10 THz. The pulse energy of the radiation is found to be above 100 μJ per steradian in the laser specular direction at an optimal preplasma scale length around 40-50 μm. Particle-in-cell simulations indicate that the radiation is mainly produced by linear mode conversion from electron plasma waves, which are excited successively via stimulated Raman scattering instability and self-modulated laser wakefields during the laser propagation in the preplasma. This radiation can be used not only as a powerful source for applications, but also as a unique diagnostic of parametric instabilities of laser propagation in plasmas.
Cancer stem cells are refractory to conventional therapy, which result to cancer metastasis and chemo-radioresistance. Grp78 is known to have important roles in cytoprotection and tumorigenesis in ...several cancers. We therefore examined whether Grp78 can serve as a therapeutic target for refractory stemness phenotype of head and neck cancer (HNC). Six HNC cell lines were used. Fluorescence-activated cell sorting (FACS) analysis was used to sort CD24(-)CD44(+) and Grp78(+) cells. The small interfering RNA (siRNA) knockdown and cDNA transfection were applied to examine the effects of Grp78 on cellular function. Western blot and confocol microscopy were used to determine the effects of downstream protein expressions. Xenografted mouse tumors and immunohistochemistry were used to validate the results. We found that Grp78 regulated the conversion of CD24(-)CD44(+) cells, a characteristic of HNC stem cells. The CD24(-)CD44(+)Grp78(+) cells showed superior chemo-radioresistance and invasion ability compared with CD24(-)CD44(+), Grp78(+) or the parental cells. Silencing Grp78 increased chemo-radiosensitivity, inhibited cell invasion, reverse epithelial-mesenchymal transition, suppressed cancer stemness, withdrew CD24(-)CD44(+) cell conversion and induced differentiated phenotype. Study in xenografted mice further showed that CD24(-)CD44(+)Grp78(+) cells exhibited highest tumorigenesis, compared with CD24(-)CD44(+) CD24(+)CD44(+) or the parental cells. Grp78 knockdown dramatically restrained tumor growth along with the inhibition of stem cell regulatory proteins Oct-4 and Slug. Grp78 may serve as a molecular target that can be further developed for eradication of refractory HNC with stemness phenotype.
Abstract
Background
Beijing-Tianjin-Hebei region (BTHR) is a world-class city group in China. However, haze severity of BTHR ranked in the top in China, 2014. As haze has certain impact on people's ...physical and psychological health, government has taken various measures to actively manage it in recent years. We try to answer the question: From public perception, whether haze control in BTHR has achieved a little success?
Methods
According to region and gender, we select four groups as respondents: BTHR and non-BTHR men, BTHR and non-BTHR women. We investigate their perception towards haze related issues. After collecting 400 anonymous questionnaires, we use clustering by fast search and find of density peaks (CFSFDP) algorithm to divide the investigated population into different clusters that represent different perception situations. Then, we test whether the frequency of each group divided into four clusters was consistent with the overall distribution frequency by fitting test.
Results
Questionnaires are automatically divided into four clusters by CFSFDP. The results of test (p > 0.1) show that the four groups are consistent (no significant difference) with overall clustering. Overall average score for “public perception to haze control” is 2.974 (full-score is 5.000), belonging to middle and upper level.
Conclusions
The cluster results show that there is no significant difference in the perception of haze control effect among four groups. Therefore, for the public in BTHR, there is no significant difference in their recognition of haze control compared with that in other regions, and the overall scores are all at the middle and upper levels. From public perception, effect of haze control in BTHR is in line with that in other regions.
Key messages
Using clustering algorithm and statistical test to identify the difference of public perception of haze control. From the perspective of public perception, haze control in BTHR has achieved initial results.
A novel high-throughput strategy was developed to determine the calcium precipitation activity (CPA) of mineralization bacteria used for self-healing of concrete cracks. A bacterial strain designated ...as H4 with the highest CPA of 94.8 % was screened and identified as a
Bacillus
species based on 16S rDNA sequence and phylogenetic tree analysis. Furthermore, the effects of certain influential factors on the microbial calcium precipitation process of H4 were evaluated. The results showed that lactate and nitrate are the best carbon and nitrogen sources, with optimal concentrations of approximately 25 and 18 mM, respectively. The H4 strain is able to maintain a high CPA in the pH range of 9.5–11.0, and a suitable initial spore concentration is 4.0 × 10
7
spores/ml. Moreover, an ambient Ca
2+
concentration greater than 60 mM resulted in a serious adverse impact not only on the CPA but also on the growth of H4, suggesting that the maintenance of the Ca
2+
concentration at a low level is necessary for microbial self-healing of concrete cracks.
Non-alcoholic fatty liver disease is an obesity-related chronic liver disorder ranging from simple steatosis to non-alcoholic steatohepatitis (NASH), which may progress to liver fibrosis and ...cirrhosis.
Tto investigate the role of Toll-like receptor (TLR) 4 in mediating the transition from steatosis to inflammation.
ApoE(-/-)/TLR4(mut) mice and ApoE(-/-)/TLR4 wild-type mice (ApoE(-/-)/TLR4-WT) were generated by cross-breeding an ApoE-deficient (ApoE(-/-)) strain with TLR4-mutant (TLR4(mut)) mice, which were fed with high-fat, high-cholesterol (HFHC) diet to induce obesity.
ApoE(-/-)/TLR4-WT mice fed with an HFHC diet for 12 weeks developed typical pathological features of NASH, which is associated with obesity and the metabolic syndrome. By contrast, ApoE(-/-)/TLR4(mut) mice lacking functional TLR4 were resistant to HFHC diet-induced liver inflammation and injury and were less susceptible to the diet-induced production of reactive oxygen species (ROS) and proinflammatory cytokines. In ApoE(-/-)/TLR4-WT mice, X-box binding protein-1 (XBP-1), a transcription factor involved in the unfolded protein responses, was activated in the liver by an HFHC diet, whereas XBP-1 activation was abrogated in ApoE(-/-)/TLR4(mut) mice. In primary rat Kupffer cells, endotoxin induced XBP-1 activation through ROS production, whereas siRNA-mediated knockdown of XBP-1 expression resulted in a marked attenuation in endotoxin-evoked NF-κB activation and cytokine production. Furthermore, adenovirus-mediated expression of dominant negative XBP-1 led to a significant attenuation in HFHC diet-induced liver inflammation and injury in mice.
These findings support the key role of TLR4 in Kupffer cells in mediating the progression of simple steatosis to NASH, by inducing ROS-dependent activation of XBP-1.
PDF
