Enhanced Thermoelectric Performance of n-Type PbTe via Carrier Concentration Optimization over a Broad Temperature Range.

The optimal carrier concentration of thermoelectric materials increases with increasing temperature. However, conventional aliovalent doping usually provides an approximately constant carrier concentration over the whole temperature range, which can only match the optimal carrier concentration in a narrow temperature range. In this work, n-type indium and aluminum codoped PbTe were prepared with high-pressure synthesis, followed by spark plasma sintering. While Al doping can provide a roughly constant carrier concentration with varying temperatures, In doping can trap electrons at low temperatures and release them at high temperatures, thus optimizing the carrier concentration over a broad temperature range. As a result, both electrical transport properties and thermal conductivity are optimized, and a significantly enhanced thermoelectric performance is achieved in InxAl0.02Pb0.98Te. The optimal In0.008Al0.02Pb0.98Te shows a peak ZT of 1.3 and an average ZT of 1, with a decent conversion efficiency of 14%. Current work demonstrates that optimizing carrier concentration with varying temperatures is effective to enhance the thermoelectric performance of n-type PbTe.

[Study on the mechanism of Flos Puerariae and Semen Hoveniae in treatment of alcoholic liver injury based on network pharmacology and molecular docking].

OBJECTIVE: To explore the mechanism of Flos Puerariae and Semen Hoveniae in treatment of alcoholic liver injury (ALI) based on network pharmacology and molecular docking. METHODS: The information of chemical constituents and targets of Flos Puerariae and Semen Hoveniae was collected from TCMSP and Swiss databases, and the threshold values of oral bioavailability (OB) ≥ 30%, drug likeness (DL) ≥0.18 were used to screen the potential active compounds. The GeneCard and DrugBank databases were used to obtain the targets corresponding to ALI. The common targets were queried using Venn Diagram, and the network of PPI and Gene Ontology (GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed through DAVID and Reactome database. Autodock Vina software was used for molecular docking of potential ingredients and key targets. RESULTS: A total of 21 potential active compounds and 431 therapeutic targets were gathered in Flos Puerariae and Semen Hoveniae, which involved 273 biological functions, 90 KEGG pathways and 362 Reactome pathways. The GO functions involved protein binding, ATP binding, etc.; the KEGG pathways mainly included PI3K-Akt signaling pathway and TNF signaling pathway; the Reactome pathways contained signal transduction and immune system, etc. The results of molecular docking showed that 21 potential active ingredients had good affinity with the core targets Akt1, TP53 and IL-6. CONCLUSIONS: The network pharmacology and molecular docking analysis demonstrate the synergetic effect of Flos Puerariae and Semen Hoveniae with multi-compounds, multi-targets and multi-pathways in the treatment of ALI; and also predict the possible medicinal substance, key targets and pathways, which provides clues for the new drug development and mechanism research.

A feasible strategy based on isotopic fine structures to enhance the reliability of metabolite identification by Fourier transform ion cyclotron resonance mass spectrometry.

RATIONALE: In the process of the identification of unknown metabolites, the most important thing is to determine their real chemical formulae according to the accurate masses which are determined by high-resolution mass spectrometry. However, high mass accuracy alone is not enough to exclude false candidates. Use of isotopic fine structures (IFSs) derived from Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) as a single further constraint could decisively determine the molecular formulae for unknown metabolites. METHODS: Gastrodin, an active constituent from Gastrodia elata Bl., which can penetrate through the blood-brain barrier and rapidly decompose to p-hydroxybenzyl alcohol in the brain, was selected as a model drug. The accurate masses, possible chemical formulae and IFSs of its metabolites in rat plasma were acquired using FT-ICR MS. RESULTS: Besides gastrodin, a total of eight metabolites including two phase I and six phase II metabolites were detected. Their chemical formulae were decisively determined by IFSs. Furthermore, their chemical structures were identified by comparing their fragment ions with those of gastrodin. Results indicated the metabolic pathways of gastrodin in rats including deglycosylation, oxidation, glucuronidation, sulfate conjugation and glycine conjugation. CONCLUSIONS: It is demonstrated that IFSs are effective in unambiguous determination of chemical formulae of metabolites. It could be used as a feasible strategy to enhance the reliability of metabolite identification in drug metabolism studies.

AtWDS1 negatively regulates age-dependent and dark-induced leaf senescence in Arabidopsis.

Although the involvement of ROS (reactive oxygen species) in leaf senescence is well known, the factors governing this accumulation of ROS are not fully characterized. In this study, analysis of transgenic overexpressing and knock out lines of AtWDS1 (encoding a WD repeat protein), indicates that AtWDS1 negatively regulates age-dependent and dark-induced leaf senescence. Furthermore, we observed ROS accumulation and altered tolerance of oxidative stress in atwds1 plants, as well as upregulated expression of oxidative stress-responsive genes. The location of an EGFP-AtWDS1 fusion protein in the nucleus of transformed cells and plants indicates that AtWDS1 is a nuclear protein, and, using a Dual-Luciferase assay, we showed that AtWDS1 can act as a transcription activator. However, the lack of a nuclear localization sequence in AtWDS1 suggests that its presence in the nucleus must depend on interactions with other proteins. Indeed, we found that AtWDS1 interacts directly with AtRanBPM, and that mutation of the AtRanBPM gene results in partial mislocalization of AtWDS1 in the cytoplasm. Together, these results suggest a role for AtWDS1 as a novel modulator of redox homeostasis, which responds to developmental and stress signals to regulate leaf senescence.

An available strategy for elemental composition determination of organic impurities in commercial preparations based on accurate mass and peak ratio of isotopic fine structures (IFSs) by dual mode combined-FT-ICR-MS and fraction collection technology.

A strategy to determine the elemental composition of organic impurities in commercial preparations was established by combining high-performance liquid chromatography (HPLC)-Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) and fraction collector with direct infusion-FT-ICR-MS (DI-FT-ICR-MS). Under HPLC-FT-ICR-MS mode, all impurities in model sample were chromatographically separated and collected by fraction collector according to their retention time. The accurate mass of each impurity and their candidate formulae under 1 ppm mass tolerance were calculated. Subsequently, theoretical isotopic fine structures (IFSs) of the candidate formulae were generated. Furthermore, the collected fractions were tested and the experimental IFSs of impurities were acquired by DI-FT-ICR-MS mode. Finally, the elemental composition of all impurities was decisively determined by comparing the experimental and theoretical IFSs. Our results demonstrate that the combined strategy is effective in separating impurities and acquiring accurate mass by HPLC-FT-ICR-MS, obtaining the appropriate samples by fraction collection technology for DI-FT-ICR-MS, and acquiring the IFSs of impurities by DI-FT-ICR-MS. It could be concluded that the strategy is an accurate and standard independent approach to determine the elemental composition of organic impurities in commercial preparations.

Metabolic profile of Kudiezi injection in rats by UHPLC coupled with Fourier transform ion cyclotron resonance mass spectrometry.

In this study, a reliable and sensitive ultra-high performance liquid chromatography coupled with fourier transform ion cyclotron resonance mass spectrometry method was developed for the systematic study of the metabolic profile of Kudiezi injection in rat plasma, bile, urine, and feces after intravenous administration of a single dose. The chromatographic separation was performed on an Agilent Eclipse Plus C18 column (4.6 mm × 50 mm, 1.8 µm) and the identification of prototype components and metabolites was achieved on a Bruker Solarix 7.0 T ultra-high resolution spectrometer in negative ion mode. Results indicated that a total of 76 constituents including 29 prototype compounds and 47 metabolites (10 phase I metabolites and 37 phase II metabolites) were tentatively identified. And the metabolic pathways of these prototype compounds including hydroxylation, dehydrogenation, glucuronidation, and sulfate conjugation. In conclusion, the developed method with high resolution and sensitivity was effective for screening and identification of prototypes and metabolites of Kudiezi injection in vivo. Moreover, these results would provide significant information for further pharmacokinetic and pharmacological research of Kudiezi injection in vivo.

Rapid characterization of the chemical constituents of Cortex Fraxini by homogenate extraction followed by UHPLC coupled with Fourier transform ion cyclotron resonance mass spectrometry and GC-MS.

Cortex Fraxini is an important traditional Chinese medicine. In this work, a rapid and reliable homogenate extraction method was applied for the fast extraction for Cortex Fraxini, and the method was optimized by response surface methodology. Ultra high performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry and gas chromatography with mass spectrometry were established for the separation and characterization of the constituents of Cortex Fraxini. Liquid chromatography separation was conducted on a C18 column (150 mm × 2.1 mm, 1.8 µm), and gas chromatography separation was performed on a capillary with a 5% phenyl-methylpolysiloxane stationary phase (30 m × 0.25 mm × 0.25 mm) by injection of silylated samples. According to the results, 33 chemical compounds were characterized by liquid chromatography with mass spectrometry, and 11 chemical compounds were characterized by gas chromatography with mass spectrometry, and coumarins were the major components characterized by both gas chromatography with mass spectrometry and liquid chromatography with mass spectrometry. The proposed homogenate extraction was an efficient and rapid method, and coumarins, phenylethanoid glycosides, iridoid glycosides, phenylpropanoids, and lignans were the main constituents of Cortex Fraxini. This work laid the foundation for further study of Cortex Fraxini and will be helpful for the rapid extraction and characterization of ingredients in other traditional Chinese medicines.

A rapid and sensitive UHPLC-FT-ICR MS/MS method for identification of chemical constituents in Rhodiola crenulata extract, rat plasma and rat brain after oral administration.

A rapid and sensitive UHPLC-FT-ICR MS/MS method was developed for the first time to analyze the extract of Rhodiola crenulata and the constituents absorbed into rat blood and brain after oral administration. Under the optimized conditions, a total of 64 chemical constituents were identified or tentatively characterized in vitro in 30min, and also 24 and 9 chemical constituents were detected in rat plasma and brain respectively, by comparing the retention time, accurate mass and/or MS/MS data of blank and dosed sample. The results indicated that the developed UHPLC-FT-ICR MS/MS method was suitable for detection and identifying the chemical constituents in Rhodiola crenulata extract, rat plasma and rat brain, and it could be used as a powerful and reliable analytical strategy for rapid identification of chemical constituents in vitro and in vivo for other traditional Chinese herbal medicines (TCMs). Furthermore, the detected chemical constituents in rat brain could be speculated to be the pharmacodynamic substances of Rhodiola crenulata for Alzheimer's disease (AD) and it could also provide useful chemical information for further mass spectrometry imaging and bioactive substances research on Rhodiola crenulata.

Metabolic profile of salidroside in rats using high-performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry.

A high-performance liquid chromatography coupled to Fourier transform ion cyclotron resonance mass spectrometry (HPLC-FT-ICR MS) method was developed to study the in vivo metabolism of salidroside for the first time. Plasma, urine, bile, and feces samples were collected from male rats after a single intragastric gavage of salidroside at a dose of 50 mg/kg. Besides the parent drug, a total of seven metabolites (three phase I and four phase II metabolites) were detected and tentatively identified by comparing their mass spectrometry profiles with those of salidroside. Results indicated that metabolic pathways of salidroside in male rats included hydroxylation, dehydrogenation, glucuronidation, and sulfate conjugation. Among them, glucuronidation and sulfate conjugation were the major metabolic reactions. And most important, the detection of the sulfation metabolite of p-tyrosol provides a clue for whether the deglycosylation of salidroside occurs in vivo after intragastric gavage. In summary, results obtained in this study may contribute to the better understanding of the safety and mechanism of action of salidroside.

Effect of liquid-to-solid lipid ratio on characterizations of flurbiprofen-loaded solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) for transdermal administration.

The aim of this study is to evaluate the effect of liquid-to-solid lipid ratio on properties of flurbiprofen-loaded solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs), and to clarify the superiority of NLCs over SLNs for transdermal administration. Particle size, zeta potential, drug encapsulation efficiency, in vitro occlusion factor, differential scanning calorimetry, X-ray diffractometry, in vitro percutaneous permeation profile, and stability of SLNs and NLCs were compared. Particle size, zeta potential, drug encapsulation efficiency, in vitro occlusion factor, and in vitro percutaneous permeation amount of the developed NLCs were all <200 nm, < -20 mV, >78%, >35, and >240 µg/cm(2), respectively, however, for SLNs were 280 nm, -29.11 mV, 63.2%, 32.54, and 225.9 µg/cm(2), respectively. After 3 months storage at 4 °C and 25 °C, almost no significant differences between the evaluated parameters of NLCs were observed. However, for SLNs, particle size was increased to higher than 300 nm (4 °C and 25 °C), drug encapsulation efficiency was decreased to 51.2 (25 °C), in vitro occlusion factor was also decreased to lower than 25 (4 °C and 25 °C), and the cumulative amount was decreased to 148.9 µg/cm(2) (25 °C) and 184.4 µg/cm(2) (4 °C), respectively. And DSC and XRD studies indicated that not only the crystalline peaks of the encapsulated flurbiprofen disappeared but also obvious difference between samples and bulk Compritol® ATO 888 was seen. It could be concluded that liquid-to-solid lipid ratio has significant impact on the properties of SLNs and NLCs, and NLCs showed better stability than SLNs. Therefore, NLCs might be a better option than SLNs for transdermal administration.

Metabolic profile of 2-(2-hydroxypropanamido) benzoic acid in rats by ultra high performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry.

An ultra high performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry (UHPLC-FT-ICR-MS) method was developed to investigate the in vivo metabolism of 2-(2-hydroxypropanamido) benzoic acid (HPABA), a marine-derived anti-inflammatory drug, for the first time. Plasma, urine, feces and bile samples were collected from male and female rats after a single intragastric administration of HPABA at a dose of 100mg/kg. Besides the parent drug, a total of 13 metabolites (3 phase I and 10 phase II metabolites) were detected and tentatively identified through comparing their mass spectrometry profiles with those of HPABA. Results demonstrated that metabolic pathways of HPABA in rats included decarboxylation, hydroxylation, dehydrogenation, glucuronidation, glycine conjugation and N-acetyl conjugation. In summary, this work provided valuable information regarding the metabolism of HPABA in rats, which would contribute to better understanding of its safety and mechanism of action.

Folate-polyethyleneimine functionalized mesoporous carbon nanoparticles for enhancing oral bioavailability of paclitaxel.

Polymer-functionalized carbon nanoparticles hold great promise for their use in enhancing the oral absorption of drugs with poor oral bioavailability. And since the abundant expression of folate receptors in intestinal tract, folic acid (FA) modified uniform mesoporous carbon spheres (UMCS) was used to improve oral absorption of paclitaxel, a chemotherapeutic drug with poor oral bioavailability. In this research, folate-polyethyleneimine (FA-PEI) was grafted onto acid-treated uniform mesoporous carbon spheres through one-step electrostatic attraction. PTX was loaded into mesopores of nanoparticles through solvent evaporation, present as amorphous. The release of PTX from the FA-PEI-UMCS nanoparticles exhibited an initial rapid release, followed by a sustained release. And release rate could be regulated by changing amount of FA-PEI complex on the UMCS. The uptake of PTX-encapsulated nanoparticles was studied exploiting Caco-2 cells as an in vitro model. The results of confocal microscopy and flow cytometry demonstrated that folate functionalization enhanced internalization of nanoparticles by the cells. Moreover, PTX loaded in FA-PEI-UMCS nanoparticles resulted in a 5.37-fold increase in apparent permeability (Papp) across Caco-2 cell monolayers compared to Taxol(®). And the in vivo results showed that FA-PEI-UMCS nanoparticles did not only improve the oral bioavailability of PTX, but also decrease the gastrointestinal toxicity of PTX. In conclusion, the FA-PEI-UMCS nanoparticles might be a potentially applicable system to improve oral absorption of drugs with poor oral bioavailability.

Lower BMI cutoffs to define overweight and obesity in China.

OBJECTIVE: To investigate ethnic difference in the associations of BMI with comorbidity, mortality, and body composition between mainland Chinese and U.S. whites. METHODS: Ethnic-comparison study using data from China Health and Nutrition Survey, U.S. National Health and Nutrition Examination Survey, and data from Zhejiang University (China) and Columbia University (U.S.). RESULTS: Chinese people experienced greater odds of comorbidities than whites for a given BMI after standardizing for age and sex: 43% for diabetes, 30% for dyslipidemia, 28% for hypertension, 38% for metabolic syndrome, and 48% for hyperuricemia. Comparisons of BMI-mortality associations found that the U-shaped BMI-mortality curve shifted 1-2 kg m(-2) to the left in Chinese compared to whites. Compared to whites at BMIs of 25 and 30 kg m(-2), corresponding cutoffs in Chinese were 22.5 and 25.9 kg m(-2) in men, and 22.8 and 26.6 kg m(-2) in women after both fat and fat distribution were taken into account. CONCLUSIONS: Comorbidity, mortality, and body composition data consistently support the use of lower BMI cutoffs in Chinese than those in whites.

Nanostructured lipid carriers-based flurbiprofen gel after topical administration: acute skin irritation, pharmacodynamics, and percutaneous absorption mechanism.

In order to assess the preliminary safety and effectiveness of nanostructured lipid carriers-based flurbiprofen gel (FP NLC-gel), the acute irritation test, in vivo pharmacodynamics evaluation and pharmacokinetic study were investigated after topical application. No dropsy and erythema were observed after continuous dosing 7 d of FP NLC-gel on the rabbit skin, and the xylene-induced ear drossy could be inhibited by FP NLC-gel at different dosages. The maximum concentration of FP in rats muscle was 2.03 µg/g and 1.55 µg/g after oral and topical administration, respectively. While the peak concentration in untreated muscle after topical administration was only 0.37 µg/mL. And at any time, following topical administration the mean muscle-plasma concentration ratio Cmuscle/CPlasma was obviously higher than that following oral administration. Results indicated that FP could directly penetrate into the subcutaneous muscle tissue from the administration site. Thus, the developed FP NLC-gel could be a safe and effective vehicle for topical delivery of FP.

Study on the digitized and quantified evaluating method for super information characteristics of herbal preparation by infrared spectrum fingerprints.

This paper aims to establish the infrared spectrum fingerprint (IRFP) in the absorbing region of 4,000-400 cm(-1) and its first derivative infrared spectrum fingerprints (d-IRFP) of ginkgo tablet (GT). And set up theories of the digitized and quantified evaluating method for super information characteristics by IRFPs of traditional Chinese medicine (TCM) which consists of the IRFP index, information index, fluctuation index, information fluctuation index and the quantified infrared fingerprint method (QIFM). Direct tabletting method was applied during the data collection of the IRFPs of 14 batches of GTs by Fourier transform infrared spectrometer. In terms of the digitized features, QIFM and similarity analysis of d-IRFP, sample S4 and S7 were evaluated as suspected outliers while the qualities of S1, S2, S6 and S12 were less well and the rests were relatively good. The assessing approach makes the expression and processing of superposed information in IRFP of TCM digitized simple and effective. What's more, an approach which can test total chemical contents in the complex system of TCM rapidly, simply and accurately was achieved by the application of QIFM based on IR technique. Finally, the quantitative and digitized infrared fingerprinting method was established as a novel approach to evaluate the quality of TCM.

Preparation, characteristics and assessment of a novel gelatin-chitosan sponge scaffold as skin tissue engineering material.

In order to develop a skin tissue engineering material for wound dressing application, a novel gelatin-chitosan sponge scaffold was designed and studied. The effect of chitosan and gelatin ratio on the morphology, pore size, porosity, water uptake capacity, water retention capacity and the degradation behavior were evaluated. Biocompatibility was investigated by both MTT method and AO/EB staining method. Antibacterial assessment and in vivo pharmacodynamic was also studied to evaluate the potential for wound healing. Results showed the sponge scaffold have uniform porous structure with pore size range between 120 and 140 µm, high porosity (>90%), high water uptake capacity (>1500%), high water retention capacity (>400%), and degradation percent in 28 days between 38.3 and 53.9%. Biocompatibility results showed that the activity of cells could not be affected by the nature of the sponge and it was suitable for cell adhesion and proliferation for 21 days. In vivo evaluation indicated that the sponge scaffold could offer effective support and attachment to cells for skin wound healing. In conclusion, the developed sponge scaffold was a potential skin tissue engineering material with appropriate physical properties and good biocompatibility.

Evaluation of a fully human monoclonal antibody against multiple influenza A viral strains in mice and a pandemic H1N1 strain in nonhuman primates.

Influenza virus is a global health concern due to its unpredictable pandemic potential. Frequent mutations of surface molecules, hemagglutinin (HA) and neuraminidase (NA), contribute to low efficacy of the annual flu vaccine and therapeutic resistance to standard antiviral agents. The populations at high risk of influenza virus infection, such as the elderly and infants, generally mount low immune responses to vaccines, and develop severe disease after infection. Novel therapeutics with high effectiveness and mutation resistance are needed. Previously, we described the generation of a fully human influenza virus matrix protein 2 (M2) specific monoclonal antibody (mAb), Z3G1, which recognized the majority of M2 variants from natural viral isolates, including highly pathogenic avian strains. Passive immunotherapy with Z3G1 significantly protected mice from the infection when administered either prophylactically or 1-2days post infection. In the present study, we showed that Z3G1 significantly protected mice from lethal infection when treatment was initiated 3days post infection. In addition, therapeutic administration of Z3G1 reduced lung viral titers in mice infected with different viral strains, including amantadine and oseltamivir-resistant strains. Furthermore, prophylactic and therapeutic administration of Z3G1 sustained O2 saturation and reduced lung pathology in monkeys infected with a pandemic H1N1 strain. Finally, de-fucosylated Z3G1 with an IgG1/IgG3 chimeric Fc region was generated (AccretaMab® Z3G1), and showed increased ADCC and CDC in vitro. Our data suggest that the anti-M2 mAb Z3G1 has great potential as a novel anti-flu therapeutic agent.

Two new indole-diterpenoids from the fungus Penicilliumcrustosum YN-HT-15.

Two new indole-diterpenoids named penijanthine B and penitrem H were isolated from the metabolites of the fungus Penicilliumcrustosum YN-HT-15, which was isolated from the red soil of Yunnan Province of China. The structures were determined on spectroscopic analyses and CD spectra.

Association of regional body fat with metabolic risks in Chinese women.

OBJECTIVE: To investigate the association of regional fat depots with metabolic risk factors in Chinese women. DESIGN: Total and regional fat depots including android fat and gynoid fat were measured by dual-energy X-ray absorptiometry. Central fat distribution was defined as android:gynoid fat ratio. Metabolic risk factors were defined as elevated TAG, reduced HDL-cholesterol, elevated blood pressure and elevated fasting plasma glucose. Logistic regression analyses were performed to examine the associations of regional fat depots with metabolic risk factors. The odds ratios of metabolic risks were further calculated according to tertiles of android fat and gynoid fat. SETTING: Participants were recruited from a community-based cross-sectional study. Face-to-face questionnaires, anthropometric and dual-energy X-ray absorptiometry measures were conducted. SUBJECTS: Chinese women (n 609) aged 18-79 years. RESULTS: Android fat and android:gynoid fat ratio were associated with significantly increased odds (OR = 1·4-3·7; P < 0·01) for almost all risk factors, whereas gynoid fat was independently associated with significantly decreased odds (OR = 0·3-0·6; P < 0·01). The inverse associations of gynoid fat with metabolic risk factors remained after adjusting for android fat. Even if their android fat level was in high, women in the highest tertile of gynoid fat had lower odds of having at least two metabolic risk factors compared with women in the lowest gynoid fat tertile (P for trend < 0·01). CONCLUSIONS: There were opposite associations of android and gynoid fat with metabolic risks in Chinese women. Gynoid fat rather than android fat might be a more important inclusion in metabolic disease risk evaluation in female Asians.