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1.
Langmuir ; 40(15): 8170-8179, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38581390

RESUMO

The performances of flexible piezoresistive sensors based on polymer nanocomposites are significantly affected by the environmental temperature; therefore, comprehensively investigating the temperature-dependent electromechanical response behaviors of conductive polymer nanocomposites is crucial for developing high-precision flexible piezoresistive sensors in a wide-temperature range. Herein, carbon nanotube (CNT)/polydimethylsiloxane (PDMS) composites widely used for flexible piezoresistive sensors were prepared, and then the temperature-dependent electrical, mechanical, and electromechanical properties of the optimized CNT/PDMS composite in the temperature range from -150 to 150 °C were systematically investigated. At a low temperature of -150 °C, the CNT/PDMS composite becomes brittle with a compressive modulus of ∼1.2 MPa and loses its elasticity and reversible sensing capability. At a high temperature (above 90 °C), the CNT/PDMS composite softens, shows a fluid-like mechanical property, and loses its reversible sensing capability. In the temperature range from -60 to 90 °C, the CNT/PDMS composite exhibits good elasticity and reversible sensing behaviors and its modulus, resistivity, and sensing sensitivity decrease with an increasing temperature. At room temperature (30 °C), the CNT/PDMS composite exhibits better mechanical and piezoresistive stability than those at low and high temperatures. Given that environmental temperature changes have significant effects on the sensing performances of conductive polymer composites, the effect of ambient temperature changes must be considered when flexible piezoresistive sensors are designed and fabricated.

2.
BMC Cancer ; 22(1): 1328, 2022 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-36536344

RESUMO

BACKGROUND: This study was aimed to establish the nomogram to predict patients' axillary node status by using patients' clinicopathological and tumor characteristic factors. METHODS: A total of 705 patients with breast cancer were enrolled in this study. All patients were randomly divided into a training group and a validation group. Univariate and multivariate ordered logistic regression were used to determine the predictive ability of each variable. A nomogram was performed based on the factors selected from logistic regression results. Receiver operating characteristic curve (ROC) analysis, calibration plots and decision curve analysis (DCA) were used to evaluate the discriminative ability and accuracy of the models. RESULTS: Logistic regression analysis demonstrated that CEA, CA125, CA153, tumor size, vascular-invasion, calcification, and tumor grade were independent prognostic factors for positive ALNs. Integrating all the predictive factors, a nomogram was successfully developed and validated. The C-indexes of the nomogram for prediction of no ALN metastasis, positive ALN, and four and more ALN metastasis were 0.826, 0.706, and 0.855 in training group and 0.836, 0.731, and 0.897 in validation group. Furthermore, calibration plots and DCA demonstrated a satisfactory performance of our nomogram. CONCLUSION: We successfully construct and validate the nomogram to predict patients' axillary node status by using patients' clinicopathological and tumor characteristic factors.


Assuntos
Neoplasias da Mama , Metástase Linfática , Segunda Neoplasia Primária , Feminino , Humanos , Biomarcadores Tumorais , Neoplasias da Mama/patologia , Linfonodos/patologia , Metástase Linfática/patologia , Segunda Neoplasia Primária/patologia , Nomogramas , Estudos Retrospectivos
3.
BMC Cancer ; 21(1): 68, 2021 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-33446143

RESUMO

BACKGROUND: This study was aimed to explore the predictive ability of tumor infiltrating neutrophil (TIN) in patients with breast cancer treated with neoadjuvant chemotherapy (NACT). Furthermore, the significance of TIN's dynamic change before and after NACT was investigated. METHODS: Between January 2004 and December 2017, a total of 133 patients with breast cancer who underwent NACT before surgery were enrolled in this retrospective cohort. Eighty-nine of them were able to get the core needle biopsy (CNB) samples and all the pathological samples after surgery were available. TIN was detected by immunohistochemical staining of CD66b. The optimal cut-off value was determined via receiver operating characteristic (ROC) curve analysis. The association of clinicopathologic characteristics and chemotherapy efficiency was analyzed using X2 test or Fisher's exact test or t-test as appropriate, and the prognostic significances were assessed by univariate and multivariate analyses. RESULTS: Patients with higher TIN after NACT were confirmed to be significantly associated with worse prognosis (P = 0.002). After stratifying patients into two groups, high difference group was prone to have better chemotherapy efficiency (P < 0.001) and clinical outcome in both univariate (P = 0.002) and multivariate analyses (P = 0.003). CONCLUSIONS: In this study, higher TIN after NACT was confirmed to be associated with breast cancer patients' worse chemotherapy efficiency and shorter disease-free survival (DFS). Furthermore, the TIN's dynamic change before and after NACT was firstly proved to be a more accurate predictive marker compared with TIN after NACT.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Biomarcadores Tumorais/análise , Neoplasias da Mama/patologia , Linfócitos do Interstício Tumoral/imunologia , Terapia Neoadjuvante/métodos , Recidiva Local de Neoplasia/patologia , Neutrófilos/patologia , Adulto , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/imunologia , Feminino , Seguimentos , Humanos , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/imunologia , Prognóstico , Curva ROC , Estudos Retrospectivos , Taxa de Sobrevida
4.
BMC Genomics ; 21(1): 52, 2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31948405

RESUMO

BACKGROUND: Pennisetum giganteum, an abundant, fast-growing perennial C4 grass that belongs to the genus Pennisetum, family Poaceae, has been developed as a source of biomass for mushroom cultivation and production, as a source of forage for cattle and sheep, and as a tool to remedy soil erosion. However, having a chilling-sensitive nature, P. giganteum seedlings need to be protected while overwintering in most temperate climate regions. RESULTS: To elucidate the cold stress responses of P. giganteum, we carried out comprehensive full-length transcriptomes from leaf and root tissues under room temperature (RT) and chilling temperature (CT) using PacBio Iso-Seq long reads. We identified 196,124 and 140,766 full-length consensus transcripts in the RT and CT samples, respectively. We then systematically performed functional annotation, transcription factor identification, long non-coding RNAs (lncRNAs) prediction, and simple sequence repeat (SSR) analysis of those full-length transcriptomes. Isoform analysis revealed that alternative splicing events may be induced by cold stress in P. giganteum, and transcript variants may be involved in C18 unsaturated fatty acid biosynthesis and metabolism pathways at chilling temperature in P. giganteum. Furthermore, the fatty acid composition determination and gene expression level analysis supported that C18 unsaturated fatty acid biosynthesis and metabolism pathways may play roles during cold stress in P. giganteum. CONCLUSIONS: We provide the first comprehensive full-length transcriptomic resource for the abundant and fast-growing perennial grass Pennisetum giganteum. Our results provide a useful transcriptomic resource for exploring the biological pathways involved in the cold stress responses of P. giganteum.


Assuntos
Temperatura Baixa , Ácidos Graxos Insaturados/biossíntese , Pennisetum/genética , Transcriptoma , Processamento Alternativo , Resposta ao Choque Frio , Perfilação da Expressão Gênica , Redes e Vias Metabólicas/genética , Repetições de Microssatélites , Pennisetum/metabolismo , RNA Longo não Codificante/metabolismo , Análise de Sequência de RNA , Fatores de Transcrição/genética , Ácido alfa-Linolênico/biossíntese
5.
Chem Biodivers ; 17(5): e2000056, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32190963

RESUMO

Osteoporosis (OP) is a metabolic bone disease affecting nearly 200 million individuals globally. Morinda officinalis F.C.How (MOH) has long been used as a traditional herbal medicine for the treatment of bone fractures and joint diseases in China. However, it still remains unclear how the compounds in MOH work synergistically for treating OP. In this study, we used prednisolone (PNSL)-induced zebrafish OP model to screen the antiosteoporosis components in MOH. A network pharmacology approach was further proposed to explore the underlying mechanism of MOH on OP. The PNSL-induced zebrafish model validated that two anthraquinones, one iridoid glycoside, and two saccharides exerted antiosteoporotic effect. We constructed the components-targets network and obtained the enriched Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. A total of 26 candidate compounds of MOH and 257 related targets could probably treat OP through regulating osteoclast differentiation and MAPK signaling pathway. Our work developed a strategy to screen the antiosteoporosis components and explore the underlying mechanism of MOH for treating OP at a network pharmacology level.


Assuntos
Modelos Animais de Doenças , Medicamentos de Ervas Chinesas/farmacologia , Morinda/química , Osteoporose/tratamento farmacológico , Animais , Diferenciação Celular/efeitos dos fármacos , China , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/isolamento & purificação , Medicina Tradicional Chinesa , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Osteoclastos/patologia , Osteoporose/induzido quimicamente , Osteoporose/metabolismo , Prednisolona , Peixe-Zebra
6.
BMC Cancer ; 18(1): 967, 2018 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-30305062

RESUMO

BACKGROUND: Conventional chemotherapy is commonly used to treat non-small cell lung cancer (NSCLC) however it increases therapeutic resistance. In contrast, metronomic chemotherapy (MET) is based on frequent drug administration at lower doses, resulting in inhibition of neovascularization and induction of tumor dormancy. This study aims to evaluate the inhibitory effects, adverse events, and potential mechanisms of MET Vinorelbine (NVB) combined with an angiogenesis inhibitor (Endostar). METHODS: Circulating endothelial progenitor cells (CEPs), apoptosis rate, expression of CD31, vascular endothelial growth factor (VEGF), hypoxia inducible factor-1 (HIF-1α) were determined using flow cytometry, western blot analysis, immunofluorescence staining and Enzyme-linked immunosorbent assay (ELISA) analysis. And some animals were also observed using micro fluorine-18-deoxyglucose PET/computed tomography (18F-FDG PET/CT) to identify changes by comparing SUVmax values. In addition, white blood cell (WBC) counts and H&E-stained sections of liver, lungs, kidney, and heart were performed in order to monitor toxicity assessments. RESULTS: We found that treatment with MET NVB + Endo was most effective in inhibiting tumor growth, decreasing expression of CD31, VEGF, HIF-1α, and CEPs, and reducing side effects, inducing apoptosis, such as expression of Bcl-2, Bax and caspase-3. Administration with a maximum tolerated dose of NVB combined with Endostar (MTD NVB + Endo) demonstrated similar anti-tumor effects, including changes in glucose metabolism with micro fluorine-18-deoxyglucose PET/computed tomography (18F-FDG PET/CT) imaging, however angiogenesis was not inhibited. Compared with either agent alone, the combination of drugs resulted in better anti-tumor effects. CONCLUSION: These results indicated that MET NVB combined with Endo significantly enhanced anti-tumor and anti-angiogenic responses without overt toxicity in a xenograft model of human lung cancer.


Assuntos
Administração Metronômica , Protocolos de Quimioterapia Combinada Antineoplásica , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Endostatinas , Neoplasias Pulmonares/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Vinorelbina , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carcinoma Pulmonar de Lewis , Carcinoma Pulmonar de Células não Pequenas/irrigação sanguínea , Linhagem Celular Tumoral , Endostatinas/administração & dosagem , Endostatinas/efeitos adversos , Humanos , Neoplasias Pulmonares/irrigação sanguínea , Camundongos , Vinorelbina/administração & dosagem , Vinorelbina/efeitos adversos , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Molecules ; 23(7)2018 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-29949909

RESUMO

A novel isoquinoline alkaloid, mahimbrine A, possessing a rare benzotropolone framing scaffold, was isolated from the endemic plant of Mahonia imbricata. Its structure was established on the basis of extensive spectroscopic analysis. A plausible biosynthetic route of mahimbrine A was proposed. Mahimbrine A showed no antimicrobial activity at the concentration of 1 mg/mL.


Assuntos
Alcaloides/química , Biflavonoides/química , Catequina/análogos & derivados , Isoquinolinas/química , Mahonia/química , Alcaloides/síntese química , Alcaloides/farmacologia , Anti-Infecciosos/farmacologia , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Catequina/química , Isoquinolinas/síntese química , Isoquinolinas/farmacologia , Testes de Sensibilidade Microbiana , Espectroscopia de Prótons por Ressonância Magnética
8.
Int J Mol Sci ; 18(11)2017 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-29137155

RESUMO

Fructokinase (FRK) proteins play important roles in catalyzing fructose phosphorylation and participate in the carbohydrate metabolism of storage organs in plants. To investigate the roles of FRKs in cassava tuber root development, seven FRK genes (MeFRK1-7) were identified, and MeFRK1-6 were isolated. Phylogenetic analysis revealed that the MeFRK family genes can be divided into α (MeFRK1, 2, 6, 7) and ß (MeFRK3, 4, 5) groups. All the MeFRK proteins have typical conserved regions and substrate binding residues similar to those of the FRKs. The overall predicted three-dimensional structures of MeFRK1-6 were similar, folding into a catalytic domain and a ß-sheet ''lid" region, forming a substrate binding cleft, which contains many residues involved in the binding to fructose. The gene and the predicted three-dimensional structures of MeFRK3 and MeFRK4 were the most similar. MeFRK1-6 displayed different expression patterns across different tissues, including leaves, stems, tuber roots, flowers, and fruits. In tuber roots, the expressions of MeFRK3 and MeFRK4 were much higher compared to those of the other genes. Notably, the expression of MeFRK3 and MeFRK4 as well as the enzymatic activity of FRK were higher at the initial and early expanding tuber stages and were lower at the later expanding and mature tuber stages. The FRK activity of MeFRK3 and MeFRK4 was identified by the functional complementation of triple mutant yeast cells that were unable to phosphorylate either glucose or fructose. The gene expression and enzymatic activity of MeFRK3 and MeFRK4 suggest that they might be the main enzymes in fructose phosphorylation for regulating the formation of tuber roots and starch accumulation at the tuber root initial and expanding stages.


Assuntos
Frutoquinases/genética , Genes de Plantas , Manihot/enzimologia , Manihot/genética , Família Multigênica , Motivos de Aminoácidos , Sequência de Aminoácidos , Cromossomos de Plantas/genética , Clonagem Molecular , Sequência Conservada , DNA Complementar/genética , Éxons/genética , Frutoquinases/química , Frutoquinases/metabolismo , Perfilação da Expressão Gênica , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Teste de Complementação Genética , Íntrons/genética , Filogenia , Raízes de Plantas/genética , Tubérculos/genética , Domínios Proteicos , Saccharomyces cerevisiae/metabolismo , Alinhamento de Sequência , Análise de Sequência de DNA , Especificidade por Substrato
9.
Int J Mol Sci ; 18(5)2017 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-28498327

RESUMO

Hexokinase (HXK) proteins play important roles in catalyzing hexose phosphorylation and sugar sensing and signaling. To investigate the roles of HXKs in cassava tuber root development, seven HXK genes (MeHXK1-7) were isolated and analyzed. A phylogenetic analysis revealed that the MeHXK family can be divided into five subfamilies of plant HXKs. MeHXKs were clearly divided into type A (MeHXK1) and type B (MeHXK2-7) based on their N-terminal sequences. MeHXK1-5 all had typical conserved regions and similar protein structures to the HXKs of other plants; while MeHXK6-7 lacked some of the conserved regions. An expression analysis of the MeHXK genes in cassava organs or tissues demonstrated that MeHXK2 is the dominant HXK in all the examined tissues (leaves, stems, fruits, tuber phloems, and tuber xylems). Notably, the expression of MeHXK2 and the enzymatic activity of HXK were higher at the initial and expanding tuber stages, and lower at the mature tuber stage. Furthermore, the HXK activity of MeHXK2 was identified by functional complementation of the HXK-deficient yeast strain YSH7.4-3C (hxk1, hxk2, glk1). The gene expression and enzymatic activity of MeHXK2 suggest that it might be the main enzyme for hexose phosphorylation during cassava tuber root development, which is involved in sucrose metabolism to regulate the accumulation of starch.


Assuntos
Hexoquinase/genética , Manihot/genética , Proteínas de Plantas/genética , Sequência Conservada , Hexoquinase/química , Hexoquinase/metabolismo , Manihot/enzimologia , Família Multigênica , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Domínios Proteicos
10.
Zhongguo Zhong Yao Za Zhi ; 42(22): 4426-4430, 2017 Nov.
Artigo em Zh | MEDLINE | ID: mdl-29318846

RESUMO

The study aims at investigating the ecological environment Adiantum reniforme var. sinense of in Three Gorges Reservoir region, and providing a reference basis for the protection of resources and artificial cultivation of A. reniforme var. sinense. By using the method of investigation, field survey and experimental analysis, the vegetation, natural geographical environment, climate, soil nutrients of A. reniforme var. sinense were studied and analyzed. The survey found that A. reniforme var. sinense distribution area reduced fast in Three Gorges region, a lot of distribution has diminished and vanished due to excessive digging, currently only in 3 towns of Wanzhou there exist 4 wild distribution areas. The growth of A. reniforme var. sinense needs an environment with low altitude, steep slope and thin soil, northeast slope, canopy height and warm and humid climate characteristics, and the soil in distribution has the characteristics of high organic matter, available nitrogen, available potassium, and low available phosphorus content.


Assuntos
Adiantum/crescimento & desenvolvimento , Dispersão Vegetal , China , Clima , Nitrogênio , Fósforo , Plantas Medicinais/crescimento & desenvolvimento , Potássio , Solo/química
11.
Yi Chuan ; 38(11): 979-991, 2016 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-27867148

RESUMO

Haploids are individuals with gametophytic chromosome numbers. Homozygous doubled haploids can be quickly gained by genome doubling. Haploids and doubled haploids play an important role on crop breeding, mutant screening, gene functional analysis, cytological studies, construction of genetic population and so on, and have been a research hotspot of plants in recent years. In this review, we summarize the production means, identification, the genetic mechanism and the applications of haploids and doubled haploids. We hope to provide a reference for study and application of haploids and doubled haploids.


Assuntos
Haploidia , Plantas/genética , Cruzamento , Cromossomos de Plantas/genética , Cromossomos de Plantas/metabolismo , Plantas/metabolismo
12.
Phys Chem Chem Phys ; 17(36): 23667-73, 2015 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-26299873

RESUMO

Quantitative structural parameters of pyrochlore Nd2Ru2O7, with temperature dependence, have been derived upon fitting XRD and EXAFS data. An anomalous expansion of the lattice parameter and the Ru-O bond length indicates a structural instability at low temperatures; in particular, an increase in the non-thermal term of the mean square fluctuation in the bond length is the evidence for a static disorder of Ru atoms. This static disorder is closely correlated with a decrease in the average Ru-O-Ru bond angle with decreasing temperature, favoring the short-range ferromagnetic coupling in the material. This ferromagnetic coupling formed thus triggered the spin frustration at low temperature when the contradictory constraints of antiferromagnetic interaction act upon the same Ru site in the corner-sharing tetrahedrons of pyrochlore Nd2Ru2O7. This study demonstrates that the spin frustration arising from the competition of ferromagnetic/antiferromagnetic interactions in pyrochlore Nd2Ru2O7 will cause structural instability especially on the atomic scale, which provides a new point of view to help understand its particular magnetic state.

13.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(5): 1409-13, 2015 May.
Artigo em Zh | MEDLINE | ID: mdl-26415469

RESUMO

Temperature drift will be brought to Micro-Spectrometer used for demodulating the Varied Line-Space(VLS) grating position sensor on aircraft due to high-low temperature shock. We successfully made a Micro-Spectrometer, for the VLS grating position sensor on aircraft, which still have stable output under temperature shock enviro nment. In order to present a real time temperature compensation scheme, the effects temperature change has on Micro-Spectrometer are analyzed and the traditional cross Czerny-Turner (C-T)optical structure is optimized. Both optical structures are analyzed by optics design software ZEMAX and proved that comparedwithtraditional cross C-T optical structure, the newone can accomplish not only smaller spectrum drift but also spectrum drift with better linearity. Based on the new optical structure. The scheme of using reference wavelength to accomplish real time temperature compensation was proposed and a Micro-fiber Spectrometer was successfully manufactured, whith is with Volume of 80 mm X 70 mmX 70 mm, integration time of 8 ~1 000 ms and FullWidthHalfMaximum(FWHM) of 2 nm. Experiments show that the new spectrometer meets the design requirement. Under high temperature in the range of nearly 60 °C, the standard error of wavelength of this new spectrometer is smaller than 0. 1 nm, and the maximum error of wavelength is 0. 14 nm, which is much smaller than required 0. 3 nm. Innovations of this paper are the schemeof real time temperature compensation, the new cross C-T optical structure and a Micro-fiber Spectrometer based on it.

14.
Mol Vis ; 20: 1434-42, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25352749

RESUMO

PURPOSE: We conducted a meta-analysis aiming to evaluate the relationship between a common polymorphism (rs2511989 G>A) in the SERPING1 gene and the risk of age-related macular degeneration (AMD). METHODS: The PubMed, CISCOM, CINAHL, Web of Science, Google Scholar, EBSCO, Cochrane Library, and CBM databases were searched for relevant articles published before November 1, 2013, without any language restrictions. A meta-analysis was conducted using STATA 12.0 software. We calculated a crude odds ratio (OR) with a 95% confidence interval (95% CI) to evaluate the relationships under five genetic models. RESULTS: Seven case-control studies with a total of 7,159 patients with AMD and 5,797 healthy subjects met the inclusion criteria. The results of our meta-analysis showed that the SERPING1 rs2511989 polymorphism might be correlated with an increased risk of AMD (G allele versus A allele: OR = 1.09, 95% CI = 1.03-1.15, p = 0.020; GG + GA versus AA: OR = 1.14, 95% CI = 1.03-1.26, p = 0.014; GG versus GA+AA: OR = 1.10, 95% CI = 1.02-1.19, p = 0.012; GG versus AA: OR = 1.20, 95% CI = 1.07-1.34, p = 0.002; respectively). Results of subgroup analysis by ethnicity revealed positive correlations between the SERPING1 rs2511989 polymorphism and risk of AMD among Caucasians under five genetic models (all p<0.05), but not among Asians (all p>0.05). CONCLUSIONS: The current meta-analysis shows that the SERPING1 rs2511989 polymorphism may have a positive effect on the risk of AMD, especially among Caucasians.


Assuntos
Proteínas Inativadoras do Complemento 1/genética , Predisposição Genética para Doença , Degeneração Macular/genética , Polimorfismo de Nucleotídeo Único , Idoso , Idoso de 80 Anos ou mais , Alelos , Povo Asiático , Estudos de Casos e Controles , Proteína Inibidora do Complemento C1 , Feminino , Humanos , Degeneração Macular/etnologia , Degeneração Macular/patologia , Masculino , Pessoa de Meia-Idade , Modelos Genéticos , Razão de Chances , Fatores de Risco , População Branca
15.
Opt Express ; 22 Suppl 2: A416-24, 2014 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-24922251

RESUMO

Structural and optical properties of thick InGaN layers with strain and composition inhomogeneities are investigated. High resolution x-ray diffractions (XRD) and reciprocal space mapping (RSM) along an asymmetric axis reveal that the In composition inhomogeneity is accompanied by strain relaxations during the growth of thick InGaN layers. According to the structural analysis, the commonly observed double photoluminescence (PL) peaks have been confirmed to be associated with the strain relaxation in thick InGaN films. Temperature-dependent PL measurements further indicate that the relaxed phase in InGaN films exhibits better emission efficiency than the strained phase. Recombination dynamics reveal that the carrier localization effect is more pronounced in the relaxed phase due to the compositional pulling effect. The correlations between emission efficiency and localization effect in thick InGaN films are discussed.

16.
Appl Microbiol Biotechnol ; 98(24): 10223-30, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25064353

RESUMO

The vertical distributions of methane-oxidizing bacteria (MOBs) and sulfate-reducing bacteria (SRBs) in the marine sediment core of DH-CL14 from the Dongsha region, the South China Sea, were investigated. To enumerate MOBs and SRBs, their specific genes of pmoA and apsA were quantified by a culture-independent molecular biological technique, real-time polymerase chain reaction (RT-PCR). The result shows that the pmoA gene copies per gram of sediments reached the maximum of 1,118,679 at the depth of 140-160 cm. Overall considering the detection precision, sample amount, measurement cost, and sensitivity to the seepage of methane from the oil/gas reservoirs or gas hydrates, we suggest that the depth of 140-160 cm may be the optimal sampling position for the marine microbial exploration of oils, gases, and gas hydrates in the Dongsha region. The data of the pmoA and apsA gene copies exhibit an evident coupling relation between MOBs and SRBs as illustrated in their vertical distributions in this sediment core, which may well be interpreted by a high sulfate concentration inhibiting methane production and further leading to the reduction of MOBs. In comparison with the numbers of the pmoA and apsA copies at the same sediment depth, we find out that there were two methane-oxidizing mechanisms of aerobic and anaerobic oxidation in this sediment core, i.e., the aerobic oxidation with free oxygen dominantly occurred above the depth of 210-230 cm, while the anaerobic oxidation with the other electron acceptors such as sulfates and manganese-iron oxides happened below the depth of 210-230 cm.


Assuntos
Bactérias/crescimento & desenvolvimento , Bactérias/metabolismo , Sedimentos Geológicos/microbiologia , Metano/metabolismo , Sulfatos/metabolismo , Carga Bacteriana , China , DNA Bacteriano/química , DNA Bacteriano/genética , Genes Bacterianos , Dados de Sequência Molecular , Oxirredução , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de DNA
17.
AAPS PharmSciTech ; 15(5): 1228-37, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24889735

RESUMO

The purpose of this study is to characterize the inter-grade and inter-batch variability of sodium alginate used in the formulation of matrix tablets. Four different grades and three batches of one grade of sodium alginate were used to prepare matrix tablets. Swelling, erosion, and drug release tests of sodium alginate matrix tablets were conducted in a USP dissolution apparatus. Substantial differences in swelling and erosion behavior of sodium alginate matrix tablets were evident among different viscosity grades. Even different batches of the same grade exhibit substantial differences in the swelling and erosion behavior of their matrix tablets. The erosion behavior of sodium alginate matrix tablets can be partly explained by their rheological properties (both apparent viscosity and viscoelasticity) in solution. Sodium alginate with higher apparent viscosity and viscoelasticity in solution show slower erosion rate and higher swelling rate. Compacts prepared from grades or batches with higher viscosity and higher viscoelasticity show slower drug release. For grades or batches with similar apparent viscosities, apparent viscosities of sodium alginate solution at low concentration alone are not sufficient to predict the functionality of sodium alginate in matrix tablets. Viscoelastic properties of sodium alginate solutions at one high concentration corresponding to the polymer gel state, may be suitable indicia of the extended release behavior of sodium alginate matrix tablets.


Assuntos
Alginatos/química , Excipientes/química , Excipientes/normas , Comprimidos/química , Comprimidos/normas , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Cinética , Porosidade , Reologia , Solubilidade , Resistência à Tração , Viscosidade , Água/química
18.
Zhongguo Zhong Yao Za Zhi ; 39(5): 833-7, 2014 Mar.
Artigo em Zh | MEDLINE | ID: mdl-25204174

RESUMO

The aim of this study is to compare the contents of five types of anthraquinones which mainly includes chrysophanol, physcion, emodin, rhein and physcion and phenolic acids in ten different processed products from Rheum officinale, and to investigate the effect of different initial processing method on the contents of anthraquinones and phenolic acids. Principal component analysis (PCA) was carried out by SPSS software to evaluate the quality of different processed products from Rh. officinale. In conclusion, the contents of anthraquinones in different processed products from Rh. officinale assume the certain regularity. Whether fresh-cut Rheum officinale Bail and how to dry it are derectly effect the contents of anthraquinones and phenolic compounds. The content of anthraquinones in rheum officinale of drying is obviously higher than smudging, and was more abundant in branch root than tap roots. Rh. officinale of drying which growed in Fengjie gained the highest score in PCA. Meanwhile, the procedure of wetting also help to increase the content of anthraquinones and decrease the content of phenolic acids.


Assuntos
Antraquinonas/química , Química Farmacêutica/métodos , Medicamentos de Ervas Chinesas/química , Hidroxibenzoatos/química , Rheum/química
19.
Zhong Yao Cai ; 37(1): 45-9, 2014 Jan.
Artigo em Zh | MEDLINE | ID: mdl-25090702

RESUMO

OBJECTIVE: To study on the pharmacognostical characteristics of cultivated Fritillaria taipaiensis for providing basis for further development and research. METHODS: Botanical, macroscopic and microscopic identifications, and determination of the content of extract, total saponins and total alkaloids were carried out. RESULTS: Because of various growing years, cultivated Fritillaria taipaiensis had diffferent properties,in addition to tip slightly resembling songbei's tip "embracing the moon", there were greatly different characteristics in the rest of specifications comparing with the traditional Fritillaria cirrhosa. Some were shallow conical or cylindrical, some had slightly rough surface,and some bases were constricted, bitter in taste. There were great differences in its extract and total alkaloids con-tent,and no obvious differences in the content of total saponins. CONCLUSION: The experimental results show that the extract,total saponins and total alkaloids content are not positively correlated or relevant with the current classification of Fritillariae Cirrhosae Bulbus. To consider the medicinal appearance diameter and length, the grade classification should be based on different application requirements, and combined with the evaluation of active ingredients.


Assuntos
Alcaloides/análise , Fritillaria/anatomia & histologia , Fritillaria/química , Plantas Medicinais/química , Saponinas/análise , Medicamentos de Ervas Chinesas/química , Fritillaria/classificação , Farmacognosia , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/química , Plantas Medicinais/anatomia & histologia , Controle de Qualidade , Especificidade da Espécie , Espectrofotometria Ultravioleta
20.
Ying Yong Sheng Tai Xue Bao ; 35(5): 1337-1346, 2024 May.
Artigo em Zh | MEDLINE | ID: mdl-38886433

RESUMO

Shanxi Province holds an important strategic position in the overall ecological pattern of the Yellow River Basin. To investigate the changes of the ecological environment in the Shanxi section of the Yellow River Basin from 2000 to 2020, we selected MODIS remote sensing image data to determine the remote sensing ecological index (RSEI) based on the principal component analysis of greenness, humidity, dryness, and heat. Then, we analyzed the spatial and temporal variations of ecological quality in this region to explore the influencing factors. We further used the CA-Markov model to simulate and predict the ecological environment under different development scenarios in the Shanxi section of the Yellow River Basin in 2030. The results showed that RSEI had good applicability in the Shanxi section of the Yellow River Basin which could be used to monitor and evaluate the spatiotemporal variations in its ecological environment. From 2000 to 2020, the Shanxi section of the Yellow River Basin was dominated by low quality habitat areas, in which the ecological environment quality continued to improve from 2000 to 2010 and decreased from 2010 to 2020. The high quality habitat areas mainly located on the mountainous areas with superior natural conditions and rich biodiversity, while the low ecological quality areas were mainly in the Taiyuan Basin and the northern part of the study area, where the mining industry developed well. Climate factors were negatively correlated with ecological environment quality in the northern and central parts of the study area, and positively correlated with that in the mountainous area. Under all three development scenarios, the area of cultivated land, forest, water and construction land increased in 2030 compared to that in 2020. Compared to the natural development scenario and the cultivated land protection scenario, the ecological constraint scenario with RSEI as the limiting factor had the highest area of new forest and the lowest expansion rate of cultivated land and construction land. The results would provide a reference for land space planning and ecological environment protection in the Shanxi section of the Yellow River Basin.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Monitoramento Ambiental , Tecnologia de Sensoriamento Remoto , Rios , China , Monitoramento Ambiental/métodos , Imagens de Satélites , Ecologia
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