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•The phase composition rule has been clarified for the TiZrNbMoV HEAs.•The HEAs with low content of Mo and V have single bcc phase and excellent phase stability.•The compressive ...mechanical properties for these HEAs have been evaluated.•TiZrNbMo0.3V0.3 has excellent specific yield strength, strain and phase stability.•A new parameter, named as shear modulus mismatch, has been proposed.
TiZrNbMoxVy high-entropy alloys (HEAs) with x=0–2, y=1 and y=0.3, respectively, were designed and prepared by copper mold casting technology. The phase composition and stability of these HEAs were investigated. It is shown that the HEAs with low content of V are composed of only one type of bcc solid solution phase (SSP), and demonstrate excellent phase stability at 1273K. The high content of V and Mo results in the formation of two types of bcc SSPs and the decrease of phase stability in the HEAs. Based on the previously proposed criteria, the formation ability of solid solution phase for this kind of HEAs was comprehensively evaluated. The compressive mechanical properties of the as-cast and annealed HEAs were measured. It has been found that Mo plays a strong solid solution strengthening effect on this kind of HEAs. Especially, TiZrNbMo0.3V0.3 has the yield strength and plastic strain of 1312MPa and >50%, respectively, and still maintains the excellent plastic deformation ability even after annealed at 1273K for 72h. The strengthening effect in this kind of HEAs is considered to be due to the shear modulus mismatch. The solubility limit of HEAs is correspondent to shear modulus mismatch of 29.
Decorin (dcn) and biglycan (bgn), two members of the family of small leucine‐rich proteoglycans (SLRPs), are the predominant proteoglycans expressed in skin and bone, respectively. Targeted ...disruption of the dcn gene results in skin laxity and fragility, whereas disruption of the bgn gene results in reduced skeletal growth and bone mass leading to generalized osteopenia, particularly in older animals. Here, we report that bgn deficiency leads to structural abnormality in collagen fibrils in bone, dermis, and tendon, and to a “subclinical” cutaneous phenotype with thinning of the dermis but without overt skin fragility. A comparative ultrastructural study of different tissues from bgn‐ and dcn‐deficient mice revealed that bgn and dcn deficiency have similar effects on collagen fibril structure in the dermis but not in bone. Ultrastructural and phenotypic analysis of newly generated bgn/dcn double‐knockout (KO) mice revealed that the effects of dcn and bgn deficiency are additive in the dermis and synergistic in bone. Severe skin fragility and marked osteopenia characterize the phenotype of double‐KO animals in which progeroid changes are observed also in the skin. Ultrastructural analysis of bone collagen fibrils in bone of double‐KO mice reveals a complete loss of the basic fibril geometry with the emergence of marked “serrated fibril” morphology. The phenotype of the double‐KO animal mimics directly the rare progeroid variant of human Ehlers‐Danlos syndrome (EDS), in which skin fragility, progeroid changes in the skin (reduced hypodermis), and osteopenia concur as a result of impaired glycosaminoglycan (GAG) linking to bgn and dcn core proteins. Our data show that changes in collagen fibril morphology reminiscent of those occurring in the varied spectrum of human EDS are induced by both bgn deficiency and dcn deficiency in mice. The effects of an individual SLRP deficiency are tissue specific, and the expression of a gross phenotype depends on multiple variables including level of expression of individual SLRPs in different tissues and synergisms between different SLRPs (and likely other macromolecules) in determining matrix structure and functional properties.
Repair of load-bearing bone defects remains a challenge in the field of orthopaedic surgery. In the current study, a surface microstructured porous titanium (STPT) successively treated with H
2
O
2
.../TaCl
5
solution and simulated body fluid was used to repair the critical-sized segmental bone defects in rabbit femur, and non-treated porous titanium (NTPT) and porous biphasic calcium phosphate ceramics (PBCP) were used as control, respectively. A 15 mm long implant was positioned in the femoral defect and stabilized by a plate and screws fixation. After implantation into the body for 1, 3 and 6 months, X-ray observation confirmed that porous titanium groups (NTPT and STPT) provided better mechanical support than PBCP group at the early stage. However, there was no obvious difference in the formed bony callus between PBCP and STPT groups in the later stage, and they both showed better shape of bony callus than NTPT group. Micro-CT and histomorphometric analysis for the samples of 6-month implantation demonstrated that more new bone formed in the inner pores of PBCP and STPT groups than that in NTPT group. Moreover, the biomechanical tests revealed that STPT group could bear larger compressive load than NTPT and PBCP groups, almost reaching the level of the normal rabbit femur. STPT exhibited the enhanced repairing effect on the critical-sized segmental bone defect in rabbit femur, meaning that it could be an ideal material for the repair of large bone defect in load-bearing site.
A novel two-step intercritical annealing process was designed for an ultra-low carbon medium manganese steel plate. Excellent mechanical properties with yield strength of 590MPa, tensile strength of ...840MPa, total elongation of 28.5% and high impact energy of 106J at −80°C were obtained. The microstructure comprised of ultra-fine grained ferrite and retained austenite together with a small amount of martensite after the two-step intercritical annealing. Both lath-like and blocky retained austenite with volume fraction of ~25% and relatively poor stability were obtained. The submicron-sized lath-like retained austenite exhibited Nishiyama-Wassermann (N-W) orientation relationship with the neighboring martensitic ferrite lath. The fine grain size played a crucial role in stabilizing austenite during phase transformation by significantly lowering Ms temperature and increasing the elastic strain energy. The overall stability of retained austenite during deformation was considered to be mainly governed by the chemical composition of the studied steel. The mechanism of toughening was elucidated. The superior low-temperature toughness was associated with TRIP effect of metastable retained austenite, which relieved the local stress concentration, enhanced the ability to plastic deformation and delayed the initiation and propagation of microcracks.
Highlights • The difference between glucose–BSA and glycoaldehyde–BSA: effects on PC12 cells. • The protective effect mediated by GLP-1 receptor on AGE-induced neurotoxicity. • GLP-1 can reduce cell ...tau phosphorylation induced by high glucose or glucose–BSA. • GLP-1 regulated tau phosphorylation through a signaling pathway involving GSK-3β.
Multifunctional single crystalline tin-doped indium oxide (ITO) nanowires with tuned Sn doping levels are synthesized via a vapor transport method. The Sn concentration in the nanowires can reach 6.4 ...at.% at a synthesis temperature of 840 °C, significantly exceeding the Sn solubility in ITO bulks grown at comparable temperatures, which we attribute to the unique feature of the vapor-liquid-solid growth. As a promising transparent conducting oxide nanomaterial, layers of these ITO nanowires exhibit a sheet resistance as low as 6.4 Ω/Symbol: see text and measurements on individual nanowires give a resistivity of 2.4 × 10(-4) Ω cm with an electron density up to 2.6 × 10(20) cm(-3), while the optical transmittance in the visible regime can reach ∼ 80%. Under the ultraviolet excitation the ITO nanowire samples emit blue light, which can be ascribed to transitions related to defect levels. Furthermore, a room temperature ultraviolet light emission is observed in these ITO nanowires for the first time, and the exciton-related radiative process is identified by using temperature-dependent photoluminescence measurements.
Background
Pomegranate peels have been widely used to treat diarrhea in China. The antidiarrheal activities of aqueous extracts of pomegranate peels have been evaluated. However, there have not been ...any bioactivity‐guided fractionation studies on the antidiarrheal effect to identify the bioactive components of the extract.
Methods
Bioactivity‐guided fractionation of an aqueous extract of pomegranate peels was performed using different solvents of increasing polarity, generating fractions dissolved in ethyl acetate, n‐butyl alcohol, and the residual fraction. The principal chemical composition of the active fraction was analyzed by HPLC/ESI‐MS.
Key Results
Fecal frequencies revealed that only the ethyl acetate fraction possessed significant antidiarrheal activity. Furthermore, administration of the ethyl acetate fraction at 100, 200, and 400 mg/kg significantly reduced gastrointestinal transit in charcoal meal tests in mice. It also significantly inhibited castor oil‐induced enteropooling compared to control animals. Histopathological analysis revealed that small intestine lesions of mice treated with the ethyl acetate fraction were alleviated compared to those in mice treated with castor oil. The ethyl acetate fraction was found to be composed mainly of punicalagin, corilagin, and ellagic acid, and a combination of these compounds could mediate the antidiarrheal activities.
Conclusion and Inferences
Our study describes the protective effects of pomegranate peels against castor oil‐induced diarrhea. The findings showed that the ethyl acetate fraction was the active fraction of pomegranate peels, of which punicalagin, corilagin, and ellagic acid were responsible for the antidiarrheal effect of aqueous extracts.
The antidiarrheal activities of aqueous extracts of pomegranate peels have been evaluated. However, the effective ingredients of antidiarrheal activities need to be determined.( The ethyl acetate fraction was the active fraction of pomegranate peels, of which punicalagin, corilagin, and ellagic acid were responsible for the antidiarrheal effect of aqueous extracts. )Determination of effective ingredients is conductive to the application of pomegranate peels on diarrheal diseases.
Aims
To evaluate the possibility of elephant grass acid hydrolysate converting into bacterial cellulose (BC) produced by Gluconacetobacter xylinus CH001 and to characterize the morphology and ...structure of the cellulose produced.
Methods and Results
Acid‐hydrolysed and detoxified elephant grass acid hydrolysate was inoculated with G. xylinus CH001. After 14 days of static fermentation, about 6·4 g l−1 of BC could be generated. Meanwhile, 60·4% (w/w) of BC yield on sugar consumption was obtained. Scanning electron micrographs illustrated that the network of cellulose fibres became denser, and the diameter changed with the growth. FT‐IR spectra showed almost same results for all the BC samples collected on different culture time. X‐ray diffractograms demonstrated that the crystalline form of BC was cellulose I, the crystallinity increased to 53·58%, and the crystallinity index reached up to 99%.
Conclusions
Elephant grass acid hydrolysate could be utilized efficiently for BC production by G. xylinus CH001. Structure analysis on the cellulose produced showed its potential of being excellent material for further application.
Significance and Impact of the Study
Our studies for the first time examined the bioconversion of low‐cost elephant grass into high‐value BC and the changes in its morphology and structure following the culture time.
A sensitive and convenient immunoassay that can directly differentiate pandemic (H1N1) 2009 (pH1N1) virus from seasonal influenza virus can play an important role in the clinic. In the presented ...study, a double-sandwich ELISA (pH1N1 ELISA), based on two monoclonal antibodies against haemagglutinin (HA) of the pH1N1 virus, was developed. After laboratory determination of the sensitivity and specificity characteristics, the performance of this assay was evaluated in a cohort of 904 patients with influenza-like illness. All seven strains of pH1N1 virus tested were positive by pH1N1 ELISA, with an average lower detection limit of 103.0 ± 0.4 tissue culture infective dose (TCID)50/mL (or 0.009 ± 0.005 HA titre). Cross-reaction of the assay with seasonal influenza virus and other common respiratory pathogens was rare. In pH1N1-infected patients, the sensitivity of the pH1N1 ELISA was 92.3% (84/91, 95% CI 84.8–96.9%), which is significantly higher than that of the BD Directigen EZ Flu A + B test (70.3%, p <0.01). The specificity of pH1N1 ELISA in seasonal influenza A patients was 100.0% (171/171, 95% CI 97.9–100.0%), similar to that in non-influenza A patients (640/642, 99.7%, 95% CI 98.9–100.0%). The positive predictive value for pH1N1 ELISA was 97.7% and the negative predictive value was 99.1% in this study population with a pH1N1 prevalence of 10.1%. In conclusion, detection of HA of pH1N1 virus by immunoassay appears to be a convenient and reliable method for the differential diagnosis of pH1N1 from other respiratory pathogens, including seasonal influenza virus.
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