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1.
Clin Respir J ; 18(4): e13742, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38664220

RESUMO

BACKGROUND: Allergic asthma is an important respiratory system problem characterized by airway inflammation, breathlessness, and bronchoconstriction. Allergic asthma and its outcomes are triggered by type 2 allergic immune responses. Tectorigenin is a methoxy-isoflavone with anti-inflammatory effects. In this study, we investigated the effects of tectorigenin on the pathophysiology of allergic asthma in an animal model. METHODS: Asthmatic mice were treated with tectorigenin. Then airway hyperresponsiveness (AHR), eosinophil percentage, levels of interleukin (IL)-33, IL-25, IL-13, IL-5, IL-4, total and ovalbumin (OVA)-specific immunoglobulin (Ig)E, and lung histopathology were evaluated. RESULT: Tectorigenin significantly (P 〈 0.05) reduced eosinophil infiltration (41 ± 7%) in the broncho-alveolar lavage fluid (BALF), serum IL-5 level (41 ± 5, pg/mL), and bronchial and vascular inflammation (scores of 1.3 ± 0.2 and 1.1 ± 0.3, respectively) but had no significant effects on AHR, serum levels of IL-33, -25, -13, and -4 (403 ± 24, 56 ± 7, 154 ± 11, and 89 ± 6 pg/mL, respectively), total and OVA-specific IgE (2684 ± 265 and 264 ± 19 ng/mL, respectively), goblet cell hyperplasia, and mucus production. CONCLUSION: Tectorigenin could control inflammation and the secretion of inflammatory mediators of asthma, so it can be regarded as a potential antiasthma treatment with the ability to control eosinophilia-related problems.


Assuntos
Anti-Inflamatórios , Antioxidantes , Asma , Modelos Animais de Doenças , Isoflavonas , Camundongos Endogâmicos BALB C , Ovalbumina , Animais , Asma/tratamento farmacológico , Asma/induzido quimicamente , Asma/metabolismo , Asma/imunologia , Asma/patologia , Camundongos , Ovalbumina/toxicidade , Ovalbumina/efeitos adversos , Isoflavonas/farmacologia , Isoflavonas/uso terapêutico , Antioxidantes/farmacologia , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Imunoglobulina E/sangue , Líquido da Lavagem Broncoalveolar/citologia , Líquido da Lavagem Broncoalveolar/imunologia , Feminino , Pulmão/patologia , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/imunologia , Citocinas/metabolismo
2.
Phytochemistry ; 219: 113988, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38224846

RESUMO

Hedscandines A-C (1-3), three undescribed indole alkaloids were isolated from Hedyotis scandens Roxb, a traditional Chinese medicine widely used in the treatment of respiratory ailments. Their structures were elucidated by extensive spectroscopic data and electronic circular dichroism calculation. Hedscandine A (1), possessed a unique carbon skeleton with a 1,4-oxazonin-2(3H)-one core system and displayed a rapid bactericidal activity against MRSA with a MIC value of 16 µg/mL. Mechanistic studies showed that compound 1 could disrupt the integrity of bacterial cell membranes and thus lead to bacterial death.


Assuntos
Hedyotis , Staphylococcus aureus Resistente à Meticilina , Antibacterianos/química , Testes de Sensibilidade Microbiana , Alcaloides Indólicos/química
3.
Zhongguo Zhong Yao Za Zhi ; 48(22): 6082-6087, 2023 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-38114215

RESUMO

This study aimed to investigate the chemical constituents in the water extract of the whole herb of Hedyotis scandens by silica gel, ODS, and MCI column chromatographies together with preparative high-performance liquid chromatography(HPLC). The structures of isolated constituents were identified by NMR, HR-ESI-MS, etc. Thirteen compounds were isolated and identified as methyl 4-benzoyloxy-3-methoxybenzeneacetate(1), 4-benzoyloxy-3-methoxybenzeneacetic acid(2), 3-(4-hydroxy-3-methoxyphenyl)-propanoic acid(3), salicylic acid(4), 3-hydroxy-4-methoxypyridine(5), syringic acid(6), hydroxycinnamic acid(7),(R)-6-methyl-4,6-bis(4-methylpent-3-enyl)cyclohexa-1,3-dienecarbaldehyde(8), 1,2-bis(4-hydroxy-3-methoxyphenyl)-1,3-propanediol(9), 1H-indole-3-carboxaldehyde(10), isoscopoletin(11), syringaresinol(12), and pinoresinol(13). Among them, compounds 1 and 2 were new phenolic acid compounds, compounds 3-5, 8-11, and 13 were isolated from this genus for the first time, and compounds 6, 7, and 12 were obtained from H. scandens for the first time. The activity test showed that compounds 1 and 10 had a certain inhibitory effect on Mycobacterium smegmatis, with MIC_(50) values of 58.5 and 33.3 µg·mL~(-1), respectively.


Assuntos
Medicamentos de Ervas Chinesas , Hedyotis , Hedyotis/química , Medicamentos de Ervas Chinesas/química , Espectroscopia de Ressonância Magnética , Ácido Salicílico
4.
World J Clin Cases ; 11(27): 6543-6550, 2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37900223

RESUMO

BACKGROUND: Stroke is the second and third leading cause of death and disability, respectively. To date, no definitive treatment can repair lost brain function. Recently, various preclinical studies have been reported on mesenchymal stromal cells (MSCs) and their derivatives and their potential as alternative therapies for stroke. CASE SUMMARY: A 45-year-old female suffered an acute stroke, which led to paralysis in the left upper and lower limbs. The amniotic membrane MSC-derived secretome (MSC-secretome) was intravenously transplanted once a week for 4 wk. MSC-secretome-regulated regulatory T cells were investigated for the beneficial effects. The clinical improvement of this patient was accompanied by an increased frequency of regulatory T cells after transplantation. CONCLUSION: Intravenous administration of MSC-secretome can potentially treat patients who suffer from acute ischemic stroke.

5.
PLoS One ; 18(1): e0279994, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36649276

RESUMO

A DNA barcode is a short piece of standard DNA sequence used for species determination and discrimination. Representation of DNA barcodes is essential for DNA barcodes' applications in the transportation and recognition of biological materials. Previously, we have compared different strategies for representing the DNA barcodes. In the present study, we have developed a compression algorithm based on binary coding or Huffman coding scheme, followed by converting the binary digits into Base64 digits. The combination of this compression algorithm and the QR representation leads to the dynamic DNA QR coding algorithm (DDQR). We tested the DDQR algorithm on simulated data and real DNA barcode sequences from the commonly used plant and animal DNA barcode markers: rbcL, matK, trnH-psbA, ITS2, and COI. We compared the compression efficiency of DDQR and another state-of-the-art DNA compression algorithm GeCo3 for sequences with various base compositions and lengths. We found that DDQR had a higher compression rate than GeCo3 for DNA sequences shorter than 800 bp, which is the typical size range for DNA barcodes. We also upgraded a web server (http://www.1kmpg.cn/ddqr) that provides three functions: retrieval of DNA barcode sequences, encoding DNA barcode sequences to DDQR codes, and decoding DDQR codes to DNA barcode sequences. The DDQR algorithm and the webserver will be invaluable to applying DNA barcode technology in the food and traditional medicine industries.


Assuntos
Código de Barras de DNA Taxonômico , Compressão de Dados , Animais , DNA de Plantas/genética , Plantas/genética , Algoritmos , Análise de Sequência de DNA , Filogenia
6.
Biology (Basel) ; 11(12)2022 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-36552300

RESUMO

Sertoli cells play indispensable roles in spermatogenesis by providing the advanced germ cells with structural, nutritional, and regulatory support. Lactate is regarded as an essential Sertoli-cell-derived energy metabolite that nurses various types of spermatogenic cells; however, this assumption has not been tested using genetic approaches. Here, we have reported that the depletion of lactate production in Sertoli cells by conditionally deleting lactate dehydrogenase A (Ldha) greatly affected spermatogenesis. Ldha deletion in Sertoli cells significantly reduced the lactate production and resulted in severe defects in spermatogenesis. Spermatogonia and spermatocytes did not show even mild impairments, but the spermiogenesis of Ldha conditional knockout males was severely disrupted. Further analysis revealed that 2456 metabolites were altered in the sperm of the knockout animals, and specifically, lipid metabolism was dysregulated, including choline, oleic acid, and myristic acid. Surprisingly, choline supplementation completely rescued the spermiogenesis disorder that was caused by the loss of Ldha activities. Collectively, these data have demonstrated that the interruption of Sertoli-cell-derived lactate impacted sperm development through a choline-mediated mechanism. The outcomes of these findings have revealed a novel function of lactate in spermatogenesis and have therapeutic applications in treating human infertility.

7.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 47(10): 1461-1466, 2022 Oct 28.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-36411698

RESUMO

Pseudohypoparayhyroidism (PHP) is a rare autosomal dominant or recessive genetic disorder characterized by low calcium, high phosphorus, and target organ resistance to parathyroid. The clinical characteristics and genetic features in 4 patients with Type Ib PHP in the Third Xiangya Hospital, Central South University, have been reviewed. All 4 patients had low calcium, high phosphorus, and parathyroid resistance. Among them, 2 patients had slightly elevated thyroid stimulating hormone and mild features of Albright's hereditary osteodystrophy, and one patient had hypokalemia. No guanine nucleotide-binding protein alpha-stimulating activity polypeptide 1 (GNAS) and gene variant associated with hypokalemia were identified using the whole exome sequencing. The results of the methylation-specific multiple ligation-dependent probe amplification showed that there were abnormal methylation of the upstream differentially methylated regions of GNAS in the 4 patients. There were phenotype overlap among the various subtypes of PHP. Detection of GNAS gene methylation in patients with clinical suspicion of Type Ib PHP is helpful for the diagnosis and treatment of PHP.


Assuntos
Hipopotassemia , Pseudo-Hipoparatireoidismo , Humanos , Cromograninas/genética , Subunidades alfa Gs de Proteínas de Ligação ao GTP/genética , Cálcio , Pseudo-Hipoparatireoidismo/genética , Fósforo
8.
Eco Environ Health ; 1(1): 11-22, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38078201

RESUMO

There are increasing concerns over the threat of nanoplastics to environmental and human health. However, multidisciplinary barriers persist between the communities assessing the risks to environmental and human health. As a result, the hazards and risks of nanoplastics remain uncertain. Here, we identify key knowledge gaps by evaluating the exposure of nanoplastics in the environment, assessing their bio-nano interactions, and examining their potential risks to humans and the environment. We suggest considering nanoplastics a complex and dynamic mixture of polymers, additives, and contaminants, with interconnected risks to environmental and human health. We call for comprehensive integration of One Health approach to produce robust multidisciplinary evidence to nanoplastics threats at the planetary level. Although there are many challenges, this holistic approach incorporates the relevance of environmental exposure and multi-sectoral responses, which provide the opportunity to identify the risk mitigation strategies of nanoplastics to build resilient health systems.

9.
J Hazard Mater ; 373: 250-257, 2019 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-30921576

RESUMO

Biochar system technology has been proved as a sustainable remediation method for metal contaminated soils. However, little attention has been paid to the interaction between biochar and oxide minerals and their influence on metal immobilization in soils. In this study, batch-type Zn sorption experiments were conducted using the mixture of γ-Al2O3 and rice straw biochar as a model binary geosorbent systems. In addition, advanced spectroscopic technics such as EXAFS, FTIR and XRD were performed to reveal the mechanism. EXAFS spectroscopy revealed that 62% of Zn existed as Zn-Al layered double hydroxide (LDH) on γ-Al2O3 at pH 7.5 (for 2 mM Zn loading) within 24 h, which was 19% in the mixture. The Zn in biochar samples mainly existed as Zn-OM (53%-76%) and Zn2SiO4 (21%-47%), while the proportion of Zn2SiO4 (0-6%) was negligible compared with Zn-Al silicate (26-48%) in the mixtures. The overall findings confirmed that Al released from γ-Al2O3 was sorbed in parallel with Zn on biochar to form Zn-Al silicate, rather than Zn-Al LDH on the γ-Al2O3 surface. These results unveiled the dynamic interactions between amended biochar and soil oxide minerals which can significantly affect the immobilization pathways of metals in contaminated soils.


Assuntos
Óxido de Alumínio/química , Carvão Vegetal/química , Zinco/isolamento & purificação , Adsorção , Óxido de Alumínio/análise , Carvão Vegetal/análise , Microscopia Eletrônica de Varredura , Oryza
10.
Environ Int ; 126: 234-241, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30822652

RESUMO

Apart from surface complexation, precipitation of minerals also plays an important role in reducing the mobility and transport of heavy metals in the environment. In this study, Cd(II) sorption species on surfaces of γ-Al2O3 at pH 7.5 were characterized using multiple techniques. Results show that in addition to adsorption complexes, Cd hydroxide phases (Cd(OH)2 precipitates and Cdx(OH)y polynuclear complexes) were formed at the initial stages of Cd(II) sorption and gradually transformed to CdCO3 with time. In addition, Cd(II) formed CdAl layered double hydroxide (LDH) on γ-Al2O3 under various conditions, independent of temperature and Cd loadings. The formation of Cd hydroxide phases and CdAl LDH could be ascribed to surface-induced precipitation because the bulk solution was undersaturated with respect to hydroxides. CdAl LDH formation on the Al-bearing mineral here is rather surprising because typically this occurs with elements of ionic radii similar to that of Al3+; this formation is unknown for metals such as Cd(II) with a much larger ionic radius. The thermodynamic feasibility of CdAl LDH formation was further confirmed by laboratory synthesis of CdAl LDH and density function theory (DFT) calculations. These results suggest that Cd precipitation on Al-bearing minerals can be an important mechanism for Cd immobilization in the natural environment. Additionally, the finding of CdAl LDH formation on Al-bearing minerals and the thermodynamic stability of CdAl LDH provides new insights into the remediation of Cd-polluted soils and aquatic systems.


Assuntos
Óxido de Alumínio/química , Cádmio/química , Adsorção , Precipitação Química , Recuperação e Remediação Ambiental , Hidróxidos/química
11.
Chemosphere ; 178: 309-316, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28340456

RESUMO

Contaminants zinc (Zn) and arsenate (As) often coexist in soils. However, little is known concerning the impacts of coexisting As on Zn adsorption and precipitation on soil minerals. In the present study, adsorption and precipitation of Zn on γ-alumina in the absence and presence of arsenate was investigated employing batch experiments and Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy. Results indicated that Zn formed edge-sharing tetrahedral surface complexes at pH 5.5 and Zn-Al LDH-like (layered double hydroxide) precipitates at pH 7.0 on the surface of γ-alumina. The presence of arsenate significantly enhanced Zn sorption densities, and remarkably changed its bonding environment. At pH 5.5, SR-XRD (Synchrotron Radiation-based X-ray Diffraction) and EXAFS showed that koettigite-like precipitate were formed in the cosorption of Zn and As on γ-alumina regardless of the addition sequence of As and Zn. At pH 7.0, when Zn was preequilibrated with γ-alumina prior to the As introduction, mixed Zn-Al LDH-like and amorphous adamite-like precipitates formed. However, when Zn and As were added simultaneously, only amorphous adamite-like precipitate was observed. Zn inner-sphere complexes and surface ternary complexes γ-alumina-As-Zn were the main outcome when As was preequilibrated firstly. Zn-arsenate precipitates could significantly decrease the concentration of Zn in aqueous solution and decrease the bioavailability and mobilization of Zn in soils.


Assuntos
Óxido de Alumínio/química , Recuperação e Remediação Ambiental/métodos , Poluentes do Solo/isolamento & purificação , Zinco/isolamento & purificação , Adsorção , Arseniatos/química , Precipitação Química , Concentração de Íons de Hidrogênio , Hidróxidos , Minerais/química , Espectroscopia por Absorção de Raios X , Difração de Raios X , Zinco/química
12.
Environ Pollut ; 220(Pt B): 997-1004, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27876416

RESUMO

Extracellular polymeric substances (EPS) isolated from bacteria, are abound of functional groups which can react with metals and consequently influence the immobilization of metals. In this study, we combined with Zn K-edge Extended X-ray Absorption Fine Structure (EXAFS), Fourier Transform Infrared (FTIR) spectroscopy, and High-Resolution Transmission Electron Microscopy (HRTEM) techniques to study the effects of EPS isolated from Bacillus subtilis and Pseudomonas putida on Zn sorption on γ-alumina. The results revealed that Zn sorption on aluminum oxide was pH-dependent and significantly influenced by bacterial EPS. At pH 7.5, Zn sorbed on γ-alumina was in the form of Zn-Al layered doubled hydroxide (LDH) precipitates, whereas at pH 5.5, Zn sorbed on γ-alumina was as a Zn-Al bidentate mononuclear surface complex. The amount of sorbed Zn at pH 7.5 was 1.3-3.7 times higher than that at pH 5.5. However, in the presence of 2 g L-1 EPS, regardless of pH conditions and EPS source, Zn + EPS + γ-alumina ternary complex was formed on the surface of γ-alumina, which resulted in decreased Zn sorption (reduced by 8.4-67.8%) at pH 7.5 and enhanced Zn sorption (increased by 10.0-124.7%) at pH 5.5. The FTIR and EXAFS spectra demonstrated that both the carboxyl and phosphoryl moieties of EPS were crucial in this process. These findings highlight EPS effects on Zn interacts with γ-alumina.


Assuntos
Óxido de Alumínio/química , Zinco/química , Adsorção , Bacillus subtilis/química , Concentração de Íons de Hidrogênio , Hidróxidos , Polímeros/química , Pseudomonas putida/química , Espectroscopia de Infravermelho com Transformada de Fourier , Espectroscopia por Absorção de Raios X
13.
Artigo em Inglês | MEDLINE | ID: mdl-27847528

RESUMO

Leukemia is the most common malignancy among all childhood cancers and is associated with a low survival rate in adult patients. Since 1995, the National Health Insurance (NHI) program in Taiwan has been offering insurance coverage for Traditional Chinese Medicine (TCM), along with conventional Western medicine (WM). This study analyzes the status of TCM utilization in Taiwan, in both pediatric and adult patients with leukemia. A retrospective cohort study was conducted using population-based National Health Insurance Research Database of Registry of Catastrophic Illness, involving patient data from 2001 to 2010 and follow-up data through 2011. The effectiveness of TCM use was evaluated. Relevant sociodemographic data showed that both pediatric and adult patients who were TCM users one year prior to leukemia diagnosis were more likely to utilize TCM services for cancer therapy. A greater part of medical expenditure of TCM users was lower than that of TCM nonusers, except little discrepancy in drug fee of adult patients. The survival rate is also higher in TCM users. Altogether, these data show that TCM has the potential to serve as an adjuvant therapy when combined with conventional WM in the treatment of patients with leukemia.

14.
Sci Rep ; 6: 21669, 2016 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-26899134

RESUMO

Astragalus membranaceus is an important medicinal plant in Asia. Several of its varieties have been used interchangeably as raw materials for commercial production. High resolution genetic markers are in urgent need to distinguish these varieties. Here, we sequenced and analyzed the chloroplast genome of A. membranaceus (Fisch.) Bunge var. mongholicus (Bunge) P.K. Hsiao using the next generation DNA sequencing technology. The genome was assembled using Abyss and then subjected to gene prediction using CPGAVAS and repeat analysis using MISA, Tandem Repeats Finder, and REPuter. Finally, the genome was subjected phylogenetic and comparative genomic analyses. The complete genome is 123,582 bp long, containing only one copy of the inverted repeat. Gene prediction revealed 110 genes encoding 76 proteins, 30 tRNAs, and four rRNAs. Five intra-specific hypermutation loci were identified, three of which are heteroplasmic. Furthermore, three gene losses and two large inversions were identified. Comparative genomic analyses demonstrated the dynamic nature of the Papilionoideae chloroplast genomes, which showed occurrence of numerous hypermutation loci, frequent gene losses, and fragment inversions. Results obtained herein elucidate the complex evolutionary history of chloroplast genomes and have laid the foundation for the identification of genetic markers to distinguish A. membranaceus varieties.


Assuntos
Astragalus propinquus/genética , Genes de Plantas , Variação Genética , Genoma de Cloroplastos , Filogenia , Astragalus propinquus/classificação , Sequência de Bases , Evolução Biológica , Deleção de Genes , Ordem dos Genes , Loci Gênicos , Marcadores Genéticos , Tamanho do Genoma , Sequências Repetidas Invertidas , Proteínas de Plantas/genética , RNA Ribossômico/genética , RNA de Transferência/genética , Alinhamento de Sequência , Análise de Sequência de DNA
15.
Chem Biol Drug Des ; 87(6): 833-40, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26706668

RESUMO

A series of novel piperlongumine derivatives (4a-i, 6a-i) were designed and synthesized. The inhibitory activities of platelet aggregation induced by ADP and AA in vitro have been evaluated by bron turbidimetry and liver microsomal incubated assay. The assay results show that compounds 4e and 6e exhibited remarkable potency to that of the positive control piplartine and aspirin.


Assuntos
Plaquetas/metabolismo , Dioxolanos , Inibidores da Agregação Plaquetária , Agregação Plaquetária/efeitos dos fármacos , Difosfato de Adenosina/farmacologia , Trifosfato de Adenosina/farmacologia , Aspirina/farmacologia , Dioxolanos/síntese química , Dioxolanos/química , Dioxolanos/farmacologia , Avaliação Pré-Clínica de Medicamentos , Humanos , Piperidonas/farmacologia , Inibidores da Agregação Plaquetária/síntese química , Inibidores da Agregação Plaquetária/química , Inibidores da Agregação Plaquetária/farmacologia
16.
Environ Sci Technol ; 47(9): 4211-9, 2013 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-23550510

RESUMO

In this research, the effects of glyphosate (GPS) on Zn sorption/precipitation on γ-alumina were investigated using a batch technique, Zn K-edge EXAFS, and (31)P NMR spectroscopy. The EXAFS analysis revealed that, in the absence of glyphosate, Zn adsorbed on the aluminum oxide surface mainly as bidentate mononuclear surface complexes at pH 5.5, whereas Zn-Al layered double hydroxide (LDH) precipitates formed at pH 8.0. In the presence of glyphosate, the EXAFS spectra of Zn sorption samples at pH 5.5 and 8.0 were very similar, both of which demonstrated that Zn did not directly bind to the mineral surface but bonded with the carboxyl group of glyphosate. Formation of γ-alumina-GPS-Zn ternary surface complexes was further suggested by (31)P solid state NMR data which indicated the glyphosate binds to γ-alumina via a phosphonate group, bridging the mineral surface and Zn. Additionally, we showed the sequence of additional glyphosate and Zn can influence the sorption mechanism. At pH 8, Zn-Al LDH precipitates formed if Zn was added first, and no precipitates formed if glyphosate was added first or simultaneously with Zn. In contrast, at pH 5.5, only γ-alumina-GPS-Zn ternary surface complexes formed regardless of whether glyphosate or Zn was added first or both were added simultaneously.


Assuntos
Absorciometria de Fóton/métodos , Óxido de Alumínio/química , Glicina/análogos & derivados , Herbicidas/química , Espectroscopia de Ressonância Magnética/métodos , Zinco/química , Glicina/química , Isótopos de Fósforo , Glifosato
17.
Environ Sci Technol ; 46(21): 11670-7, 2012 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-23043294

RESUMO

To better understand the sequestration of toxic metals such as nickel (Ni), zinc (Zn), and cobalt (Co) as layered double hydroxide (LDH) phases in soils, we systematically examined the presence of Al and the role of mineral dissolution during Zn sorption/precipitation on γ-Al(2)O(3) (γ-alumina) at pH 7.5 using extended X-ray absorption fine structure spectroscopy (EXAFS), high-resolution transmission electron microscopy (HR-TEM), synchrotron-radiation powder X-ray diffraction (SR-XRD), and (27)Al solid-state NMR. The EXAFS analysis indicates the formation of Zn-Al LDH precipitates at Zn concentration ≥0.4 mM, and both HR-TEM and SR-XRD reveal that these precipitates are crystalline. These precipitates yield a small shoulder at δ(Al-27) = +12.5 ppm in the (27)Al solid-state NMR spectra, consistent with the mixed octahedral Al/Zn chemical environment in typical Zn-Al LDHs. The NMR analysis provides direct evidence for the existence of Al in the precipitates and the migration from the dissolution of γ-alumina substrate. To further address this issue, we compared the Zn sorption mechanism on a series of Al (hydr)oxides with similar chemical composition but differing dissolubility using EXAFS and TEM. These results suggest that, under the same experimental conditions, Zn-Al LDH precipitates formed on γ-alumina and corundum but not on less soluble minerals such as bayerite, boehmite, and gibbsite, which point outs that substrate mineral surface dissolution plays an important role in the formation of Zn-Al LDH precipitates.


Assuntos
Óxido de Alumínio/química , Alumínio/química , Hidróxidos/química , Zinco/química , Adsorção , Precipitação Química , Cristalização , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Transmissão , Minerais/química , Solubilidade , Espectroscopia por Absorção de Raios X , Difração de Raios X
18.
J Chromatogr B Analyt Technol Biomed Life Sci ; 879(23): 2259-64, 2011 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-21727044

RESUMO

For the endogenous substances with an ultra-low level in biological fluids, such as melatonin, the blank biological matrix is obviously not "blank". This problem leads to a serious issue of the bioanalytical methods development and validation by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). This work developed and validated an ultra-high sensitive bioanalytical method for plasma melatonin by LC-MS/MS using water as calibration matrix. The lower limit of quantitation of the method was verified to be 1.0 pg/mL and the method exhibited a linear range of 1-5000 pg/mL. Potential matrix effects, accuracy and precision were fully monitored and validated by two complementary quality control approaches respectively using water and the pooled plasma as matrix. The intra-run and inter-run precisions were less than 11.5% and 12.2%, respectively, and the relative error was below ± 13.8% for all of 5 quality control levels. The method was successfully applied to investigate the daytime (8:00 AM-8:00 PM) baseline level of endogenous plasma melatonin, as well as the pharmacokinetic profiles of exogenous melatonin after oral administration in beagle dogs.


Assuntos
Cromatografia Líquida/métodos , Melatonina/sangue , Espectrometria de Massas em Tandem/métodos , Animais , Calibragem , Cromatografia Líquida/normas , Cães , Humanos , Masculino , Espectrometria de Massas em Tandem/normas , Água/análise
19.
Nanotechnology ; 21(21): 215103, 2010 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-20431208

RESUMO

This study aims to develop self-assembled poly(ethylene glycol)-poly(epsilon-caprolactone)-poly(ethylene glycol) (PEG-PCL-PEG, PECE) micelles to encapsulate hydrophobic honokiol (HK) in order to overcome its poor water solubility and to meet the requirement of intravenous administration. Honokiol loaded micelles (HK-micelles) were prepared by self-assembly of PECE copolymer in aqueous solution, triggered by its amphiphilic characteristic assisted by ultrasonication without any organic solvents, surfactants and vigorous stirring. The particle size of the prepared HK-micelles measured by Malvern laser particle size analyzer were 58 nm, which is small enough to be a candidate for an intravenous drug delivery system. Furthermore, the HK-micelles could be lyophilized into powder without any adjuvant, and the re-dissolved HK-micelles are stable and homogeneous with particle size about 61 nm. Furthermore, the in vitro release profile showed a significant difference between the rapid release of free HK and the much slower and sustained release of HK-micelles. Moreover, the cytotoxicity results of blank micelles and HK-micelles showed that the PECE micelle was a safe carrier and the encapsulated HK retained its potent antitumor effect. In short, the HK-micelles were successfully prepared by an improved method and might be promising carriers for intravenous delivery of HK in cancer chemotherapy, being effective, stable, safe (organic solvent and surfactant free), and easy to produce and scale up.


Assuntos
Antineoplásicos/química , Compostos de Bifenilo/química , Sistemas de Liberação de Medicamentos/métodos , Lignanas/química , Micelas , Poliésteres/química , Polietilenoglicóis/química , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Animais , Antineoplásicos/administração & dosagem , Compostos de Bifenilo/administração & dosagem , Processos de Crescimento Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Ensaios de Seleção de Medicamentos Antitumorais , Estabilidade de Medicamentos , Medicamentos de Ervas Chinesas/administração & dosagem , Medicamentos de Ervas Chinesas/química , Humanos , Lignanas/administração & dosagem , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Camundongos , Microscopia Eletrônica de Transmissão , Tamanho da Partícula , Poliésteres/administração & dosagem , Poliésteres/síntese química , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/síntese química , Solubilidade , Sonicação , Difração de Raios X
20.
Virus Genes ; 40(3): 447-51, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20221681

RESUMO

Potato virus X (PVX) is one of the most common plant viruses that cause great economic losses to solanaceous plants. We have previously reported the complete genomic sequence of the 2006 Chinese potato isolate FX21 and demonstrated that PVX isolates cluster into two groups: Eurasia and America. Here, we present the complete genomic sequence of one PVX isolate collected from potato in 1985 (PVX-1985). The genome of PVX-1985 is identical to that of FX21 in length and has the same genomic structure. PVX-1985, which like FX21 fell within the Eurasia group, clustered together with isolates from Europe, whereas FX21 clustered together with isolates of primarily Asian origin. Phylogenetic analyses of the complete genomic sequences and of CP gene sequences showed that Chinese PVX isolates have different origins and were introduced via multiple events. Though all the open reading frames of PVX are under negative/purifying selection, the central region of RNA-dependent RNA polymerase is under positive/diversifying selection.


Assuntos
Genoma Viral , Filogenia , Doenças das Plantas/virologia , Potexvirus/genética , Potexvirus/isolamento & purificação , RNA Viral/genética , Solanum tuberosum/virologia , China , Análise por Conglomerados , Epidemiologia Molecular , Dados de Sequência Molecular , Polimorfismo Genético , Potexvirus/classificação , Análise de Sequência de DNA
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