Activating lattice oxygen in high-entropy LDH for robust and durable water oxidation.

The oxygen evolution reaction is known to be a kinetic bottleneck for water splitting. Triggering the lattice oxygen oxidation mechanism (LOM) can break the theoretical limit of the conventional adsorbate evolution mechanism and enhance the oxygen evolution reaction kinetics, yet the unsatisfied stability remains a grand challenge. Here, we report a high-entropy MnFeCoNiCu layered double hydroxide decorated with Au single atoms and O vacancies (AuSA-MnFeCoNiCu LDH), which not only displays a low overpotential of 213 mV at 10 mA cm-2 and high mass activity of 732.925 A g-1 at 250 mV overpotential in 1.0 M KOH, but also delivers good stability with 700 h of continuous operation at ~100 mA cm-2. Combining the advanced spectroscopic techniques and density functional theory calculations, it is demonstrated that the synergistic interaction between the incorporated Au single atoms and O vacancies leads to an upshift in the O 2p band and weakens the metal-O bond, thus triggering the LOM, reducing the energy barrier, and boosting the intrinsic activity.

Potassium-rich antiperovskites K3HTe and K3FTe and their structural relation to lithium and sodium counterparts.

Unlike perovskite oxides, antiperovskites M3HCh and M3FCh (M = Li, Na; Ch = S, Se, Te) mostly retain their ideal cubic structure over a wide range of compositions owing to anionic size flexibility and low-energy phonon modes that promote their ionic conductivity. In this study, we show the synthesis of potassium-based antiperovskites K3HTe and K3FTe and discuss the structural features in comparison with lithium and sodium analogues. It is shown experimentally and theoretically that both compounds maintain a cubic symmetry and can be prepared at ambient pressure, in contrast to most of the reported M3HCh and M3FCh which require high pressure synthesis. A systematic comparison of a series of cubic M3HTe and M3FTe (M = Li, Na, K) revealed that telluride anions contract in the order of K, Na, Li, with a pronounced contraction in the Li system. This result can be understood in terms of the difference in charge density of alkali metal ions as well as the size flexibility of Ch anions, contributing to the stability of the cubic symmetry.

Preparation of hydroxypropyl starch/polyvinyl alcohol composite nanofibers films and improvement of hydrophobic properties.

Starch-derived edible films have great potential as biodegradable food packaging and biomedical materials, in this study, we adopted a green method to prepare starch-based composite electrospun nanofibers films. The hydroxypropyl starches (HPS) were prepared to improve native starch solubility and properties, and a series of blend solutions were prepared with different HPS/polyvinyl alcohol (PVA) weight ratios. The comparison of the properties of HPS/PVA (HPA) nanofibers with different amylose contents were evaluated, and the fibers fabricated from hydroxypropyl high amylose starch (HP-HAS) had more continuous and homogeneous morphologies compared to the other starch fibers, it was also found that the addition of HP-HAS in the film has better mechanical properties than pure PVA film. Thus, to improve the hydrophobicity of the film, the HP-HAS/PVA (HPA(H)) nanofiber was selected for the hydrophobic study by the citric acid (CA) treatment. The hydrophobic surface was formed on the HPA(H) film by CA self-assembled coating with a water contact angle changed from 30.95° up to 100.74°. This study successfully prepared the modified starch/PVA composite nanofibers and established a simple method of self-assembled hydrophobic modification to improve water stability. Therefore, this green strategy is an alternative candidate in further study for food packaging and relative areas.

Effectiveness of smart health-based rehabilitation on patients with poststroke dysphagia: A brief research report.

Objective: This study aimed to evaluate the effectiveness of smart health-based rehabilitation on patients with poststroke dysphagia (PSD). Methods: We recruited 60 PSD patients and randomly allocated them to the intervention (n = 30) and control (n = 30) groups. The former received the smart health-based rehabilitation for 12 weeks, whereas the latter received routine rehabilitation. Water swallow test (WST), standardized swallowing assessment (SSA), swallow quality-of-life questionnaire (SWAL-QOL), stroke self-efficacy questionnaire (SSEQ), perceived social support scale (PSSS) and nutritional measurements including body weight, triceps skinfold thickness (TSF), total protein (TP), serum albumin (ALB) and serum prealbumin (PA) in both groups were measured. Results: When the baseline WST, SSA, SWAL-QOL, SSEQ, PSSS and nutritional measurements were examined, there was no significant difference between the intervention group and the control group (P > 0.05). After rehabilitation interventions, the WST and SSA scores in the intervention group were significantly lower than those in the control group (P < 0.01). The SWAL-QOL, SSEQ and PSSS scores in the intervention group were significantly higher than in the control group (P < 0.01). Compared with the control group, the intervention group showed an increase in the serum levels of PA (P < 0.01). However, no statistically significant difference existed between the intervention group and the control group in terms of body weight, TSF, TP or ALB (P > 0.05). Conclusions: Overall, our data revealed that smart health-based rehabilitation is significantly beneficial to the swallowing function, quality of life, self-efficacy, and social support for PSD patients when compared with routine rehabilitation. However, nutritional measurements were not significantly improved in such patients under the smart health-based rehabilitation when compared the routine rehabilitation. In the future, it is necessary to extend the intervention time to further evaluate the long-term efficacy of smart health-based rehabilitation on nutritional measurements of PSD patients.

[Responses of radial growth of Quercus mongolica to stand density and climatic factors in a mountainous area of eastern Liaoning Province, China]. / è¾½ä¸œå±±åŒºè’™å¤æ Žå¾„å‘ç”Ÿé•¿å¯¹æž—åˆ†å¯†åº¦å’Œæ°”å€™å› å­çš„å“åº”.

To explore the effects of stand density and climatic factors on radial growth of Quercus mongolica, we used tree ring chronology to examine the radial growth changes in a secondary Q. mongolica forest under different levels of stand density (thinning). The meteorological data combined with the driving factors of Q. mongolica growth were analyzed. The results showed that the radial growth of Q. mongolica was significantly affected by stand density. The mean annual radial growth of Q. mongolica was 3.12 mm in low-density virgin forest, 1.55 and 1.42 mm in the two medium-density secondary forests, respectively, and 0.96 mm in high-density secondary forest. The thinning intensity of 20% had a limited effect on promoting the radial growth recovery of high-density forest (1900 trees·hm-2), but had a significant effect on medium-density forest (1600 trees·hm-2). The radial growth of Q. mongolica was sensitive to the precipitation changes in January and February of the current year. Thinning reduced the sensitivity of Q. mongolica radial growth to climate. Under scenarios of climate warming and drying, density regulation could be beneficial in mitigating the adverse effects of climate change on the growth of Q. mongolica.

Preparation of carboxymethyl starch/polyvinyl-alcohol electrospun composite nanofibers from a green approach.

A green approach for the preparation of starch-based composite nanofibers using electrospinning was developed. The water-soluble sodium carboxymethyl starch (CMS) with DS 0.31 was prepared. The addition of co-blending polymer polyvinyl-alcohol (PVA) was attempted to improve the CMS solution spinnability, which blends from aqueous solution were prepared at different CMS/PVA weight ratios. The solution parameters including viscosity, surface tension and conductivity were measured and the morphologies of nanofibers were observed by SEM. Smooth, continuous, and defect-free nanofibers were successfully obtained range from the blend of CMS/PVA weight ratios of 10:90 to 80:20. Diameter distribution diagrams suggested that the diameter of the nanofibers reduced with the concentration of CMS increasing. This is the first report that the thin nanofiber (135.29 nm) with bead-free was obtained at the maximal CMS content of 50.0 wt% in the CMS/PVA blend. This study provided a green approach to produce starch-based nano-scale fibers.

Panax quinquefolium saponin liposomes prepared by passive drug loading for improving intestinal absorption.

Panax quinquefolium saponin (PQS) composed of 45% pseudo-ginsenoside F11 (PF11), is a natural mixture of sterol compounds obtained from the American ginseng plant, having numerous promising benefits for health. However, low solubility and permeability limit the development of PQS as a therapeutic agent for oral administration. In this study, PQS liposomes (PQS-Lips) were prepared by thin layer hydration, an in situ single-pass intestinal perfusion (SPIP) model was used to verify the improvement of membrane permeability of PQS-Lips. PQS-Lips had a high encapsulation efficiency (EE) of 65%∼70%, a particle size about 100.0 nm, and a zeta potential of -60 mV with regular spherical surface. FTIR and DSC showed the PQS in liposomes were amorphous, indicating that hydrogen bonds formed between one or several hydroxyl groups in PQS and C-O group at the phospholipid polar terminal. In addition, PQS-Lips showed sustained release in vitro than PQS at pH 1.2 and pH 6.8, and PQS-Lips had good stability in simulated gastric and intestinal fluid. Then, the absorption rate (K a) and effective permeability coefficient (P eff) of PQS-Lips in the whole small intestine were significantly higher than those in PQS solution (PQS-Sol), which proved that the PQS-Lips could significantly increase the membrane permeability of PQS and promote its absorption in the small intestine. From the experimental results, it could be known that liposome technology could effectively improve the absorption of PQS in the small intestine.

Hypoglycemic and hypolipidemic mechanism of organic chromium derived from chelation of Grifola frondosa polysaccharide-chromium (III) and its modulation of intestinal microflora in high fat-diet and STZ-induced diabetic mice.

Polysaccharide from Grifola frondosa is an excellent metal-ion chelating agent owing to its distinctive structure and outstanding functional activities. Our previous research has successfully synthesized novel organic chromium derived from the chelation ofG. frondosapolysaccharide-chromium (III) [GFP-Cr(III)]. The purpose of present research was to reveal the hypoglycemic and hypolipidemic mechanism of GFP-Cr(III), and its relationship with the modulation of intestinal microflora. Successful fabrication of GFP-Cr(III) was verified by thermogravimetric analysis (TGA), powder X-ray diffraction (XRD) and 1H NMR spectrum.The hypoglycemic and hypolipidemic effects were examined using type 2 diabetic mice induced by a high-fat diet (HFD) and streptozocin (STZ). Results indicated that GFP-Cr(III) intervention improved abnormal serum biochemical indicators (triglyceride (TG), cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and glucose), inhibited lipid accumulation and steatosis in the liver. Metagenomic analysis revealed that GFP-Cr(III) treatment produced obvious changes on the intestinal microflora in T2DM mice. Thecorrelationnetwork analysis further revealed that the serum and hepatic lipid profiles were positively correlated with Streptococcus and Enterococcus, but negatively correlated with Enterorhabdus, Ruminococcaceae-UCG-011, Coriobacteriaceae and Micrococcaceae. Meanwhile, oral administration with GFP-Cr(III) regulated the mRNA expression related to glucose and lipid metabolism. These results of present study suggest that GFP-Cr(III) could be used as potential functional food ingredients for the amelioration of hyperglycemia and hyperlipidemia.

Effect of supersaturation on the oral bioavailability of paclitaxel/polymer amorphous solid dispersion.

The aim of the present investigation was to evaluate the effect of supersaturation on the oral absorption of paclitaxel (PTX) in vivo. To achieve this, a PTX amorphous solid dispersion (ASD) was prepared by the solvent cast method. Among the enteric polymers tested, hypromellose acetate succinate (HPMCAS) MF was found to be the most suitable polymer for maintaining PTX supersaturation and inhibiting crystallization in vitro. The dissolution rate and extent of the ASD was remarkably improved compared with a physical mixture (PM) of PTX, HPMCAS-MF, and Poloxamer 188 (F68), reaching an apparent drug concentration of 25-30 µg/mL and maintaining it for more than 2 h. The liquid-liquid phase separation (LLPS) concentration of PTX in the presence of HPMCAS-MF was determined to be 23 µg/mL, which was different to that of 40 µg/mL in the absence of polymer. It indicated that HPMCAS was substantially incorporated into the drug-rich phase. Also, HPMCAS could absorb to the PTX surface and provided an interfacial barrier for crystal growth, as well as retard the incorporation of PTX from solution into the growing crystal lattice. The results of X-ray diffraction, differential scanning calorimetry analysis, and transmission electron microscopy confirmed that PTX existed in the amorphous state in the solid dispersion. Compared with the PM group, the ASD prepared with HPMCAS-MF and F68 achieved a 1.78-fold increase in relative oral bioavailability, while PTX solution yielded a 1.56-fold increase, which could be explained that the solubility and the permeability of PTX were not increased simultaneously through supersaturation in vivo. Likely, it was because Cremophor inhibited P-glycoprotein in the intestine to some extent and maintained PTX at a higher concentration for a longer time.

Process control and in vitro/in vivo evaluation of aripiprazole sustained-release microcrystals for intramuscular injection.

This work describes the preparation of aripiprazole sustained-release microcrystals for intramuscular injection, through recrystallization, drying, wet grinding, and solidification steps, which had a great impact on the product quality. Here, we evaluated the crystal form of the drug in each step by differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and fourier transform infrared spectroscopy (FT-IR), demonstrating that there is no change in the crystal form of aripiprazole monohydrate (H1) during grinding and freeze-drying. Microscopy and scanning electron microscopy (SEM) data showed that freeze-drying had no effect on the morphology of milled H1, and thermal gravimetric analysis (TGA) results showed that the freeze-dried formulation had acceptable water content. In particular, in this study, a similarity factor fitting was applied to determine the similarity of the particle size cumulative distribution curve, and the similarity factor value (99.00) showed that there was no change in the particle size distribution before and after freeze-drying. A two-chamber transmembrane method was used to investigate the in vitro release of the aripiprazole sustained-release microcrystal (ALSI) and commercial preparations (Abilify Maintena®). The similarity factor fitting of in vitro release profiles and drug cumulative release curves in vivo yielded similarity factor values of 98.00 and 95.43, respectively, indicating similar in vitro release and in vivo bioavailability of rats between the ALSI and Abilify Maintena®. A single-dose administration could produce long-term effects for a month. For a microcrystalline suspension, in addition to the conventional quality control indicators, the similarity of the cumulative particle size distribution, the in vitro release profile, and the similarity of the drug release percentage in vivo can be used to reflect product quality and process control.

Biopharmaceutical characters and bioavailability improving strategies of ginsenosides.

Deglycosylation is the most important gastrointestinal metabolism in which ginsenosides are split off from glycosyl moieties by the enzymes secreted from intestinal microflora, and two possible metabolic pathways of protopanaxdiol-type ginsenosides (PPD-type ginsenosides) and protopanaxtriol-type ginsenosides (PPT-type ginsenosides) have been concluded. The former is deglycosylated at C-3 and/or C-20, and transformed to protopanaxdiol (PPD). By comparison, the latter is deglycosylated at C-6 and/or C-20, and eventually transformed to protopanaxtriol (PPT) instead. The pharmacokinetic behavior of PPD-type ginsenosides and PPT-type ginsenosides is different, mainly in a faster absorption and elimination rate of PPT-type ginsenosides, but almost all of ginsenosides have a low oral bioavailability, which is relevant to the properties, the stability in the gastrointestinal tract, membrane permeability and the intestinal and hepatic first-pass effect of ginsenosides. Fortunately, its bioavailability can be improved by means of pharmaceutical strategies, including nanoparticles, liposomes, emulsions, micelles, etc. These drug delivery systems can significantly increase the bioavailability of ginsenosides, as well as controlling or targeting drug release. Ginsenosides are widely used in the treatment of various diseases, the most famous one is the Shen Yi capsule, which is the world's first clinical application of tumor neovascularization inhibitors. Hence, this article aims to draw people's attention on ocotillol-type ginsenosides, which have prominent anti-Alzheimer's disease activity, but have been overlooked previously, such as its representative compound-Pseudoginsenoside F11(PF11), and then provide a reference for the druggability and further developments of ocotillol-type ginsenosides by utilizing the homogeneous structure between dammarane-type ginsenosides and ocotillol-type ginsenosides.

Membrane Loaded Copper Oleate PEGylated Liposome Combined with Disulfiram for Improving Synergistic Antitumor Effect In Vivo.

PURPOSE: This work aims to create a novel Cu2+ liposome with excellent loading stability and develop synergistic effect with disulfiram (DSF) for the treatment of tumor. METHODS: Copper oleate was incorporated into the liposome membrane via alcohol injection method in this work. In vitro release test was applied to evaluate the release profile of the liposomes. Pharmacokinetic studies were performed in rats and the antitumor efficacy was assessed in mice bearing hepatoma xenografts. RESULTS: The copper oleate liposome (Cu(OI)2-L) was formulated and the loading efficiency were more than 85%. TEM images confirmed that the Cu(OI)2-L had a spherical morphology with an average diameter of 100 nm. Cu(OI)2-L displayed a biphasic release profile, with >70% retained drug over 8 h incubation in PBS at pH 7.4. Pharmacokinetic studies demonstrated that Cu(OI)2-L had a prolonged circulation time and increased AUC when compared to the injection of copper oleate solution. The antitumor efficacy test demonstrated an enhanced tumor inhibition rate with the treatment of Cu(OI)2-L and DSF nanoparticles, indicating an improved synergistic antitumor effect. CONCLUSIONS: The Cu(OI)2-L was suitable to be employed in combination with disulfiram for tumor treatment and can also open up opportunities for targeted delivery of copper.

Nanosuspensions as delivery system for gambogenic acid: characterization and in vitro/in vivo evaluation.

Nanosuspensions (NS) can enhance the saturation solubility and dissolution velocity of poorly soluble drugs. PEG as a non-ionic surfactant plays an important role in surface modification of nanoparticles for prolonging in vivo circulation. In this study, anti-solvent precipitation method was introduced to prepare gambogenic acid nanosuspensions (GNA-NS) with PVPK30 and PEG2000 as stabilizers to settle the disadvantages of GNA. The obtained nanoparticles were spherical with a mean particle size of 183.7 nm and a zeta potential of -22.8 mV. The entrapment efficiency and drug loading of the resultant formulation were 97.3 and 29.73%. X-ray diffraction analysis confirmed the amorphous phase of GNA in NS. Fourier transform infrared indicated there may be hydrogen bond interaction between the drug and excipients. After lyophilization of GNA-NS, the freeze-dried powder displayed sufficient long-term physical stability at 4 and 25 °C. In comparison to GNA solution, in vitro studies of GNA-NS showed much slower release and higher cytotoxicity in HepG2 cells. What's more, the pharmacokinetic study in rats revealed that the AUC0-∞ and t1/2 of GNA-NS were increased 2.63- and 1.77-fold than that of the reference formulation. Taken together, in vitro/in vivo evaluations showed NS would be an effectively strategy to change the poor aqueous solubility and prolong the half-life for GNA. The GNA-NS with enhanced bioavailability and drug efficacy provided a promising delivery system for the application of GNA.

Comparison of mantoux and tine tuberculin skin tests in BCG-vaccinated children investigated for tuberculosis.

BACKGROUND: Tuberculin skin tests (TSTs) are long-established screening methods for tuberculosis (TB). We aimed to compare agreement between the intradermal Mantoux and multipuncture percutaneous Tine methods and to quantify risk factors for a positive test result. METHODOLOGY/PRINCIPAL FINDINGS: 1512 South African children younger than 5 years of age who were investigated for tuberculosis (TB) during a Bacille Calmette Guerin (BCG) trial were included in this analysis. Children underwent both Mantoux and Tine tests. A positive test was defined as Mantoux >or=15 mm or Tine >or= Grade 3 for the binary comparison. Agreement was evaluated using kappa (binary) and weighted kappa (hierarchical). Multivariate regression models identified independent risk factors for TST positivity. The Mantoux test was positive in 430 children (28.4%) and the Tine test in 496 children (32.8%, p<0.0001), with observed binary agreement 87.3% (kappa 0.70) and hierarchical agreement 85.0% (weighted kappa 0.66). Among 173 children culture-positive for Mycobacterium tuberculosis, Mantoux was positive in 49.1% and Tine in 54.9%, p<0.0001 (kappa 0.70). Evidence of digit preference was noted for Mantoux readings at 5 mm threshold intervals. After adjustment for confounders, a positive culture, suggestive chest radiograph, and proximity of TB contact were risk factors for a positive test using both TST methods. There were no independent associations between ethnicity, gender, age, or over-crowding, and TST result. CONCLUSIONS/SIGNIFICANCE: The Tine test demonstrated a higher positive test rate than the Mantoux, with substantial agreement between TST methods among young BCG-vaccinated children. TB disease and exposure factors, but not demographic variables, were independent risk factors for a positive result using either test method. These findings suggest that the Tine might be a useful screening tool for childhood TB in resource-limited countries.

Working to prevent HIV/STIs among women in the sex industry in a rural town of Hainan, China.

We evaluated a two-phase HIV/STIs prevention intervention for female sex workers in a resource-limited rural town in Hainan Province, China. The primary intervention strategy, conducted from 1997 to 2000, was a condom promotion campaign conducted through outreach to sex workers. Four serial cross-sectional surveys were carried out before and after the intervention. Over a period of 2 years, reported condom use during the most recent sexual encounter increased from about 50% to more than 70%; and condom use in more than 50% of sexual acts during the past 6 months increased from less than 40% to near 80% of respondents. Controlling for education, ethnicity and age, reading of educational materials (our intervention variable) was a significant contributor to a higher knowledge score, motivation to use condoms, and reported condom use. This study demonstrates that outreach to female sex workers, if appropriately tailored to local settings, can increase condom use in a resource-limited rural area.