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1.
Ying Yong Sheng Tai Xue Bao ; 34(5): 1203-1210, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37236936

RESUMO

To explore the adaptative strategies of single-veined plants along the environmental gradient, we collec-ted leaves of 57 Pinaceae species (including Abies, Larix, Pinus and Picea) from 48 sites along a latitudinal gradient (26°58'-35°33' N) on the eastern Qinghai-Tibet Plateau. By measuring three traits of leaf vein, including vein length per leaf area, vein diameter, and vein volume per unit leaf volume, we analyzed the trade-off between vein traits and their relationship with environmental changes. The results showed no significant difference in vein length per leaf area among different genera, but significant difference in vein diameter and vein volume per unit leaf volume. There was a positive correlation between vein diameter and vein volume per unit leaf volume for all genera. There was no significant correlation of vein length per leaf area with vein diameter and vein volume per unit leaf volume. With the increases of latitude, vein diameter and vein volume per unit leaf volume significantly decreased. In contrast, vein length per leaf area did not show a latitudinal trend. Mean annual temperature was the main factor driving the variation in vein diameter and vein volume per unit leaf volume. The relationships between vein length per leaf area and environmental factors were relatively weak. These results indicated that the single-veined Pinaceae plants have a special adaptative strategy to environmental changes through adjusting vein diameter and vein volume per unit leaf volume, which is quite different from complex vein structures such as reticular veins.


Assuntos
Pinaceae , Tibet , China , Plantas , Folhas de Planta
2.
Zool Res ; 43(2): 192-204, 2022 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-35084125

RESUMO

Environmental DNA (eDNA) integrated with metabarcoding is a promising and powerful tool for species composition and biodiversity assessment in aquatic ecosystems and is increasingly applied to evaluate fish diversity. To date, however, no standardized eDNA-based protocol has been established to monitor fish diversity. In this study, we investigated and compared two filtration methods and three DNA extraction methods using three filtration water volumes to determine a suitable approach for eDNA-based fish diversity monitoring in the Pearl River Estuary (PRE), a highly anthropogenically disturbed estuarine ecosystem. Compared to filtration-based precipitation, direct filtration was a more suitable method for eDNA metabarcoding in the PRE. The combined use of DNeasy Blood and Tissue Kit (BT) and traditional phenol/chloroform (PC) extraction produced higher DNA yields, amplicon sequence variants (ASVs), and Shannon diversity indices, and generated more homogeneous and consistent community composition among replicates. Compared to the other combined protocols, the PC and BT methods obtained better species detection, higher fish diversity, and greater consistency for the filtration water volumes of 1 000 and 2 000 mL, respectively. All eDNA metabarcoding protocols were more sensitive than bottom trawling in the PRE fish surveys and combining two techniques yielded greater taxonomic diversity. Furthermore, combining traditional methods with eDNA analysis enhanced accuracy. These results indicate that methodological decisions related to eDNA metabarcoding should be made with caution for fish community monitoring in estuarine ecosystems.


Assuntos
Código de Barras de DNA Taxonômico , DNA Ambiental , Peixes , Animais , Código de Barras de DNA Taxonômico/veterinária , Ecossistema , Monitoramento Ambiental , Peixes/genética , Água
3.
Org Biomol Chem ; 19(39): 8492-8496, 2021 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-34549771

RESUMO

Highly enantioselective formal [3 + 2] cycloaddition of N-2,2,2-trifluoroethylisatin ketimines with aurone derivatives of low reactivity using chiral dinuclear zinc catalysts has been developed via a Brønsted base and Lewis acid cooperative activation model. These transformations involving a domino Michael/Mannich reaction sequence led to efficient construction of a range of chiral spiro[benzofuran-pyrrolidine] scaffolds bearing three biologically relevant heterocyclic moieties and two adjacent spiro quaternary stereocenters in high yields (up to 95%) and with good enantioselectivities (up to 99% ee).

4.
Ciênc. rural (Online) ; 50(4): e20180911, 2020. graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1089571

RESUMO

ABSTRACT: Herbicide application is an effective weed control method for mitigating crop yield loss; however, herbicide overuse can cause toxicity in non-target plants. The present study evaluated the effects of glufosinate at recommended dose for agricultural application (0.45 kg ha-1) and at overuse dose (0.90 kg ha-1) glufosinate application on photosynthetic performance and nitrogen assimilation of the rapeseed varieties D148 and Zhongshuang 11 (ZS11). Both glufosinate concentrations significantly decreased the content of chlorophyll and nitrogenous compounds, except free proline, and the activity of glutamine synthetase and glutamate synthase, and increased the activity of glutamic acid dehydrogenase in both varieties. When the concentration of glyphosate was 0.45kg ha-1, the nitrogen assimilation of the two varieties decreased, which indicated that the recommended dosage inhibited the nitrogen assimilation of the two varieties; however, the increase of net photosynthetic rate of D148 and the decrease of that of ZS11 mean that D148 is more tolerant to the recommended dose of glyphosate than ZS11. The 0.90 kg ha-1 dosage was toxic to both rapeseed varieties. Overall, our results indicated that herbicide overuse inhibited the photosynthetic rate and nitrogen assimilation in rapeseed seedlings, and it is essential to apply a suitable glufosinate dose based on the variety grown to minimize adverse effects on crops and environment.


RESUMO: A aplicação de herbicidas é um método eficaz de controle de ervas daninhas para mitigar a perda de produtividade das culturas. No entanto, o uso excessivo de herbicidas pode causar toxicidade em plantas não alvo. O presente estudo avaliou os efeitos da dose recomendada para aplicação agrícola (0.45 kg ha-1) e dose excessiva (0.90 kg ha-1) de glufosinato no desempenho fotossintético e assimilação de nitrogênio das variedades de colza D148 e Zhongshuang 11 (ZS11). Ambas as concentrações de glutamato diminuíram significativamente o teor de clorofila e compostos azotados, exceto a prolina livre, e a atividade de síntese da glutamina e de síntese de glutamato, e aumentaram a atividade de desidrogenase do ácido glutâmico em ambas as variedades. Quando a concentração de glifosato foi 0.45 kg ha-1, a assimilação de azoto das duas variedades diminuiu, o que indicou que a dosagem recomendada de glifosato inibiu a assimilação de azoto das duas variedades de colza. Entretanto, a taxa fotosintética líquida do D148 aumentou enquanto o do ZS11 diminuiu, o que significa que o D148 é mais tolerante a dose recomendada de glifosato do que o ZS11. A dose de 0.90 kg ha-1 de glifosato foi prejudicial para as mudas de duas variedades de colza. Em geral, os nossos resultados indicam que o uso excessivo de glufosinato inibe a taxa fotossintética e a assimilação de nitrogênio em mudas de colza, sendo essencial aplicar uma dose adequada deste herbicida com base na variedade cultivada para minimizar os efeitos adversos nas culturas e no meio ambiente.

5.
Anal Chim Acta ; 1079: 207-211, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31387713

RESUMO

Signal amplification strategy have been the intensive direction for highly-sensitive microRNA (miRNA) detection, however, it is worth noting that signal quenching approach is rarely realized. Inspired by the unwinding of G-quadruplex with Klenow Fragment polymerase (KF), a simple and label-free signal quenching system for detection of miRNAs was developed. In the presence of target miRNA, miRNA was used as a primer to promote KF activity resulting in the disruption of G-quadruplex structure of probe and the biological catalysis inactivation of DNAzyme formed by G-quadruplex structure and hemin. As a result, the probe would be transformed from G-quadruplex to duplex and the obvious differential signal could be observed in most cases even with naked eyes. With the significant signal decreasing, the target miRNA can be rapidly analyzed by UV-vis spectra with a considerably low detection limit (4.5 nM). This method exhibits excellent selectivity and anti-interference ability by discriminating base-mismatched and other miRNA families from target miRNA. Meanwhile, a good recovery (90.7%∼102.4%) in 5% human serum was obtained and this strategy verified a high expression level of miR21 in total RNA of MCF-7 compared with 293T and HeLa. It implies that this assay is of great potential to be applied in biochemical research and clinical diagnosis.


Assuntos
DNA Catalítico/química , MicroRNAs/sangue , Técnicas Biossensoriais/métodos , Linhagem Celular Tumoral , Colorimetria/métodos , DNA Catalítico/genética , DNA Polimerase Dirigida por DNA/química , Quadruplex G , Células HEK293 , Hemina/química , Humanos , Limite de Detecção
6.
Angew Chem Int Ed Engl ; 58(15): 5028-5032, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30756480

RESUMO

N6 -Methyladenosine (m6 A) represents a common and highly dynamic modification in eukaryotic RNA that affects various cellular pathways. Natural dioxygenases such as FTO and ALKBH5 are enzymes that demethylate m6 A residues in mRNA. Herein, the first identification of a small-molecule modulator that functions as an artificial m6 A demethylase is reported. Flavin mononucleotide (FMN), the metabolite produced by riboflavin kinase, mediates substantial photochemical demethylation of m6 A residues of RNA in live cells. This study provides a new perspective to the understanding of demethylation of m6 A residues in mRNA and sheds light on the development of powerful small molecules as RNA demethylases and new probes for use in RNA biology.


Assuntos
Adenosina/análogos & derivados , Homólogo AlkB 5 da RNA Desmetilase/metabolismo , Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismo , Mononucleotídeo de Flavina/metabolismo , Adenosina/química , Adenosina/metabolismo , Homólogo AlkB 5 da RNA Desmetilase/análise , Dioxigenase FTO Dependente de alfa-Cetoglutarato/análise , Mononucleotídeo de Flavina/análise , Células HEK293 , Células HeLa , Humanos , Estrutura Molecular
7.
Chem Commun (Camb) ; 53(77): 10734-10737, 2017 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-28920612

RESUMO

We report a simple protocol that affords oxidative demethylation of N6-methyl groups in N6-methyl adenines (m6A). The biologically compatible photocatalyst riboflavin prompts a highly selective C-H abstraction from N6-methyl in adenines under the irradiation of a visible blue LED light, affording a novel and highly selective biomimetic demethylation of m6A and related N-methyl adenine analogues.

8.
J Chin Med Assoc ; 79(11): 633-638, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27720678

RESUMO

Familial exudative vitreoretinopathy (FEVR) is a hereditary ocular disorder characterized by a failure of peripheral retinal vascularization. In this report, we describe a novel missense mutation of the Norrie disease gene (NDP) in a Chinese family with X-linked FEVR. Ophthalmologic evaluation was performed on four male patients and seven unaffected individuals after informed consent was obtained. Venous blood was collected from the 11 members of this family, and genomic DNA was extracted using standard methods. The coding exons 2 and 3 and their corresponding exon-intron junctions of NDP were amplified by polymerase chain reaction and then subjected to direct DNA sequencing. A novel missense mutation (c.310A>C) in exon 3, leading to a lysine-to-glutamine substitution at position 104 (p.Lys104Gln), was identified in all four patients with X-linked FEVR. Three unaffected female individuals (III2, IV3, and IV11) were found to be carriers of the mutation. This mutation was not detected in other unaffected individuals. The mutation c.310A>C (p.Lys104Gln) in exon 3 of NDP is associated with FEVR in the studied family. This result further enriches the mutation spectrum of FEVR.


Assuntos
Proteínas do Olho/genética , Doenças Genéticas Ligadas ao Cromossomo X/genética , Mutação de Sentido Incorreto , Proteínas do Tecido Nervoso/genética , Doenças Retinianas/genética , Adolescente , Adulto , Idoso , Pré-Escolar , Oftalmopatias Hereditárias , Vitreorretinopatias Exsudativas Familiares , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
9.
Mol Cytogenet ; 9: 31, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27099631

RESUMO

BACKGROUND: Chromosomal abnormalities that result in genomic imbalances are main causes of congenital and developmental anomalies including intellectual disability and multiple congenital malformations. In this report we describe four patients from three families with imbalanced translocations. Only a small percentage of imbalanced translocation individuals can be born to live, most of them were aborted in embryonic period. It is of great significances to precisely analysis the chromosome variation to study the relationship between genotype and phenotype. RESULTS: Four patients showed common clinical manifestations including delayed growth, intellectual disability, language barrier and facial dysmorphisms. In addition to the above features, lower limbs dysplasia and both foot eversion were found in patient 1, brachydactylic hand, cerebellar ataxia and congenital heart defects were also found in patient 4. Conventional karyotype analysis revealed abnormal karyotypes 46, XX, der (6) t (6: 10) (p23; q24), 46, XX, der (20) t (3; 20) (p23; p13) and 46, XX, der (22) t (3; 22) (q27; q13.3) in the four patients, respectively. Array-CGH analyses confirmed 23.6 Mb duplication on 10q25.1-q26.3 and 0.9 Mb deletions on 6p25.3, 19.9 Mb duplication on 3p24.3-p26.3 and 0.25 Mb deletion on 20p13 and 12.5 Mb duplication on 3q27.2-q29 and 1.9 Mb deletions on 22q13.2-q13.33 in the four patients, respectively. CONCLUSION: Parents with balanced translocation are passed the imbalanced chromosome to patient, and the partial monosomy and partial trisomy lead to multiple congenital malformations of four patients.

11.
Artigo em Chinês | MEDLINE | ID: mdl-26541036

RESUMO

OBJECTIVE: To investigate the antimalarial activity of four choline derivatives against Plasmodium falciparum 3D7 strain growth in vitro. METHODS: Four choline derivatives MD [N-dodecyl-N-(2-hydroxyethyl)-N,N- dimethyl ammonium bromide], ED [N-dodecyl-N-(2-hydroxyethyl)-N,N-diethyl ammonium bromide], MT [N-tetradecyl-N- (2-hydroxyethyl)-N,N-dimethyl ammonium bromide], and ET [N-tetradecyl-N-(2-hydroxyethyl)-N,N-diethyl ammonium bromide] were dissolved separately in DMSO at serial concentrations (1-10(5) µmol/L). The solutions were diluted by 1,000-fold with RPMI 1640 medium. 20 µl drug-containing medium and 80 µl P. falciparum-infected erythrocyte suspension (2% final hematocrit and 0.3%-0.5% parasitemia) were added to each well of microtiter plates. Drug effect on the in vitro growth of P. falciparum was measured by SYBR Green I method. The half maximal inhibitory concentration (IC50) was calculated from dose-response curves. Artemisinine served as positive control. RESULTS: Artemisinine, MD, ED, MT, and ET showed different degrees of dose-dependent inhibition on P. falciparum growth. When the MD concentration was above 10 nmol/L, the inhibition rate increased significantly. Both ED and ET showed significant inhibitory effects at high concentrations, with inhibition rate of > 95% when their doses were > 10(4) nmol/L. The IC50 values of MD, ED, MT, and ET were 1 620, 33.9, 116, and 68.9 nmol/L, respectively, all significantly higher than that of artemisinine (5.7 nmol/L) (P < 0.05). CONCLUSION: The four choline derivatives show certain antimalarial activity, which is lower than that of artemisinine. Among the four derivatives, ED has the strongest antimalarial activity against P. falciparum 3D7 strain.


Assuntos
Plasmodium falciparum , Antimaláricos , Artemisininas , Benzotiazóis , Colina , Diaminas , Humanos , Malária Falciparum , Compostos Orgânicos , Quinolinas
12.
Int Immunopharmacol ; 24(2): 247-255, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25479721

RESUMO

Roxithromycin (RXM) expresses anti-asthmatic effects that are separate from its antibiotic activity, but its effects on airway remodeling are still unknown. Here, we evaluated the effects of RXM on airway remodeling and the expression of caveolin-1 and phospho-p42/p44mitogen-activated protein kinase (phospho-p42/p44MAPK) in chronic asthmatic rats. The chronic asthma was induced by ovalbumin/Al(OH)3 sensitization and ovalbumin challenge, RXM (30mg/kg) or dexamethasone (0.5mg/kg) was given before airway challenge initiation. We measured the thickness of bronchial wall and bronchial smooth muscle cell layer to indicate airway remodeling, and caveolin-1 and phospho-p42/p44MAPK expression in lung tissue and airway smooth muscle were detected by immunohistochemistry and western blot analysis, respectively. The results demonstrated that RXM treatment decreased the thickness of bronchial wall and bronchial smooth muscle cell layer, and also downregulated the phospho-p42/p44MAPK expression and upregulated the caveolin-1 expression. The above effects of RXM were similar to dexamethasone. Our results suggested that pretreatment with RXM could suppress airway remodeling and regulate the expression of caveolin-1 and phospho-p42/p44MAPK in chronic asthmatic rats.


Assuntos
Asma/tratamento farmacológico , Brônquios/efeitos dos fármacos , Caveolina 1/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Miócitos de Músculo Liso/efeitos dos fármacos , Roxitromicina/administração & dosagem , Remodelação das Vias Aéreas/efeitos dos fármacos , Alérgenos/imunologia , Animais , Brônquios/patologia , Caveolina 1/genética , Doença Crônica , Dexametasona/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/genética , Miócitos de Músculo Liso/fisiologia , Ovalbumina/imunologia , Ratos , Ratos Sprague-Dawley , Roxitromicina/farmacologia
13.
J. physiol. biochem ; 70(3): 761-768, sept. 2014.
Artigo em Inglês | IBECS | ID: ibc-127320

RESUMO

The biological effects of fluoride on human health are often extensive, either beneficial or detrimental. Among the various effects of fluoride exposure in different organs, the reproductive tract is particularly susceptible to disruption by fluoride at a sufficient concentration. It has attracted much attention to the effect of sodium fluoride on male fertility, gestational female, and offspring. Herein, we applied a widespread natural compound sodium fluoride (NaF) and investigated the effects of acute NaF exposure on Leydig cells, including their proliferation, apoptosis, and signal pathway changes. Our results demonstrated that high dosage of NaF could inhibit cell proliferation by stress-induced apoptosis, which was confirmed by cellular and molecular evidences. We found that fluoride exposure affected the expression levels of stress response factors, signal transduction components, and apoptosis-related proteins, including caspase-3/caspase-9, B-cell lymphoma 2 (Bcl-2), and Bax. This study suggests that the complex effects of fluoride on Leydig cells are closely related to its dosage


Assuntos
Animais , Camundongos , Fluoreto de Sódio/farmacocinética , Proliferação de Células , Apoptose , Células Intersticiais do Testículo , Caspase 3 , Caspase 9 , Linfoma de Células B , Fenômenos Reprodutivos Fisiológicos
14.
J Physiol Biochem ; 70(3): 761-8, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25074826

RESUMO

The biological effects of fluoride on human health are often extensive, either beneficial or detrimental. Among the various effects of fluoride exposure in different organs, the reproductive tract is particularly susceptible to disruption by fluoride at a sufficient concentration. It has attracted much attention to the effect of sodium fluoride on male fertility, gestational female, and offspring. Herein, we applied a widespread natural compound sodium fluoride (NaF) and investigated the effects of acute NaF exposure on Leydig cells, including their proliferation, apoptosis, and signal pathway changes. Our results demonstrated that high dosage of NaF could inhibit cell proliferation by stress-induced apoptosis, which was confirmed by cellular and molecular evidences. We found that fluoride exposure affected the expression levels of stress response factors, signal transduction components, and apoptosis-related proteins, including caspase-3/caspase-9, B-cell lymphoma 2 (Bcl-2), and Bax. This study suggests that the complex effects of fluoride on Leydig cells are closely related to its dosage.


Assuntos
Células Intersticiais do Testículo/efeitos dos fármacos , Fluoreto de Sódio/toxicidade , Animais , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Caspase 9/metabolismo , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Células Intersticiais do Testículo/metabolismo , Células Intersticiais do Testículo/patologia , Masculino , Camundongos , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fluoreto de Sódio/administração & dosagem , Proteína X Associada a bcl-2/metabolismo
15.
Zhonghua Fu Chan Ke Za Zhi ; 47(10): 742-6, 2012 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-23302731

RESUMO

OBJECTIVE: To explore the relationship between the polymorphism of methionine synthase reductase (MTRR) A66G and the susceptibility to unexplained repeated spontaneous abortion (URSA). METHODS: Total of 200 Henan Han couples with URSA (URSA group) and 76 Henan Han healthy couples without URSA (control group) were enrolled in this study. Their MTRR A66G genotypes were determined by PCR restriction fragment length polymorphism (PCR-RFLP). RESULTS: (1) The allele frequencies of MTRR A66G: the frequencies of allele A and allele G in URSA group were 76.5% (153/200) in husband and 72.8% (146/200) in wife, 23.5% (47/200) in husband and 27.2% (54/200) in wife, respectively. The frequencies of allele A and allele G in control group were 78.9% (60/76) in husband and 78.3% (59/76) in wife, 21.1% (16/76) in husband and 21.7% (16/76) in wife, respectively. The frequencies of allele A and allele G were not significantly different between female and male subjects within the same experimental group (P > 0.05), and also there were not significantly different between the same gender subjects at URAS and control groups (P > 0.05). (2) The genotype frequencies of MTRR A66G: the frequencies of genotype AA, AG and GG in URSA group were 57.0% (114/200) in husband and 52.0% (104/200) in wife, 39.0% (78/200) in husband and 41.5% (83/200) in wife, 4.0% (8/200) in husband and 6.5% (13/200) in wife, prepectively. The frequencies of genotype AA, AG and GG in control group were 59.2% (45/76) in husband and 59.2% (50/76) in wife, 39.5% (30/76) in husband and 38.2% (29/76) in wife; 1.3% (1/76) in husband and 2.6% (2/76) in wife, prepectively. The frequencies of genotype AA, AG and GG were not significantly different between female and male subjects within the same group (P > 0.05), and also there were not significantly different between the same gender subjects at URSA and control groups (P > 0.05).(3)Combined genotype of couples: the combined genotype frequencies of GG + GG, GG + AG, GG + AA, AG + AG, AG + AA and AA + AA in URSA group were 1.0% (2/200), 2.5% (5/200), 6.0% (12/200), 20.0% (40/200), 38.0% (76/200), and 32.5% (65/200), prepectively; the combined genotype frequencies in control group were 0, 1.3% (1/76), 2.6% (2/76), 17.1% (13/76), 42.1% (32/76), 36.8% (28/76), prepectively. The combined genotype analysis between the two groups were also not significantly different (P > 0.05). CONCLUSION: The polymorphism of MTRR A66G gene was not associated with the susceptibility to URSA (P > 0.05), and so it was not the inherited genetic risk factor of URSA.


Assuntos
Aborto Habitual/genética , Ferredoxina-NADP Redutase/genética , Polimorfismo Genético , Aborto Habitual/patologia , Adulto , Povo Asiático , Estudos de Casos e Controles , China , Feminino , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Reação em Cadeia da Polimerase , Gravidez , Fatores de Risco , Adulto Jovem
16.
Ying Yong Sheng Tai Xue Bao ; 23(9): 2346-52, 2012 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-23285987

RESUMO

By the methods of sequential soil cores and buried bags, an investigation was conducted to study the seasonal dynamics of fine roots in a 20-year-old Pinus massoniana plantation in Three Gorges Reservoir Area from March to December 2011, with the annual production and turnover rate of the fine roots calculated. In the plantation, the annual mean biomass of <2 mm fine roots was 146.98 g x m(-2) x a(-1), in which, the living root biomass (102.92 g x m(-2) x a(-1)) was far greater than that of the dead root biomass (44.06 g x m(-2) x a(-1)). Among the fine roots with different sizes, <1 mm fine roots had an obvious seasonal dynamics in their biomass, showing a unimodal curve in the sampling period. The annual production and turnover rate of <2 mm fine roots were 104. 12 g x m(-2) x 1(-1) and 1.05 a(-1), respectively, in which, the annual production of <1 mm and 1-2 mm fine roots was 58.35 and 45.77 g x m(-2) x a(-1), and the turnover rate was 1.41 and 0.69 a(-1), respectively.


Assuntos
Biomassa , Ecossistema , Pinus/crescimento & desenvolvimento , Raízes de Plantas/crescimento & desenvolvimento , China , Pinus/anatomia & histologia , Pinus/metabolismo , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/metabolismo , Rios , Abastecimento de Água
17.
Guang Pu Xue Yu Guang Pu Fen Xi ; 30(5): 1192-7, 2010 May.
Artigo em Chinês | MEDLINE | ID: mdl-20672599

RESUMO

Histidines provide axial ligands to the primary electron donors in photosynthetic reaction centers (RCs) and play an important role in the protein environments of these donors. In this paper the authors present a systematic study of ionization energies and vibrational properties of histidine using hybrid density functional theory (DFT). All calculations were undertaken by using B3LYP method in combination with four basis sets: 6-31G(d), 6-31G(df, p), 6-31+G(d) and 6-311+G(2d, 2p) with the aim to investigate how the basis sets influence the calculation results. To investigate solvent effects and gain a detailed understanding of marker bands of histidine, the ionization energies of histidine and the vibrational frequencies of histidine which are unlabeled and 13C, 15N, and 2H labeled in the gas phase, CCl4, protein environment, THF and water solution, which span a wide range of dielectric constant, were also calculated. Our results showed that: (1) The main geometry parameters of histidine were impacted by basis sets and mediums, and C2-N3 and N3-C4 bond of imidazole ring of histidine side chain display the maximum bond lengths in the gas phase; (2) single point energies and frequencies calculated were decreased while ionization energies increased with the increasing level of basis sets and diffuse function applied in the same solvent; (3) with the same computational method, the higher the dielectric constant of the solvent used, the lower the ionization energy and vibrational frequency and the higher the intensity obtained. In addition, calculated ionization energy in the gas phase and marker bands of histidine as well as frequency shift upon 13C and 15N labeling at the computationally more expensive 6-311+G(2d, 2p) level are in good agreement with experimental observations available in literatures. All calculations indicated that the results calculated by using higher level basis set with diffuse function were more accurate and closer to the experimental value. In conclusion, the results provide useful information for the further studies of the functional and vibrational properties of chlorophyll-a ligated to histidine residue in photosynthetic reaction center.


Assuntos
Histidina/análise , Complexo de Proteínas do Centro de Reação Fotossintética/análise , Ligantes , Vibração
18.
Zhonghua Liu Xing Bing Xue Za Zhi ; 31(3): 329-32, 2010 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-20510065

RESUMO

OBJECTIVE: To study the characteristics and influencing factors of cognition on patients with Parkinson's disease (PD) in Xi'an in order to provide evidence for early recognition and treatment of cognitive impairment on PD patients. METHODS: Clinically defined PD patients from 7 hospitals in Xi'an from Jan. to Apr. 2007 were assessed with mini-mental state examination (MMSE) and Montreal cognitive assessment (MOCA) for whole cognitive function. Furthermore, Fuld object memory test (FOM) was used to assess delayed memory while rapid verbal retrieve (RVR) was used to assess language fluency. Digit span subtest was used to assess attention and building blocks was used to assess visual space function respectively. RESULTS: 100 PD patients were recruited, including 52 men and 48 women, from 43 to 86 years old (65.6 +/- 17.1). MMSE scores was used as the standard for Recognition, PD with cognitive impairment accounted for 16%. According to MOCA scores, with PD cognitive disturbances accounted for 83%. Ability for calculation, short-term memory, visual space function, abstract capability, attention and language fluency dysfunction were main cognitive disturbances of PD. Analysis from single factor logistic regression showed that education, age of onset and gender were closely related to the occurrence of cognitive impairment on PD patients. CONCLUSION: Cognitive impairment was common in PD. Ability of calculation, short-term memory, visual space function, abstract capability, attention and language fluency dysfunction were main cognitive disturbances of PD. Cognitive impairment of PD was more likely to occur with low degree of education, late onset of PD, and being female.


Assuntos
Transtornos Cognitivos/etiologia , Doença de Parkinson/psicologia , Adulto , Idoso , Idoso de 80 Anos ou mais , China/epidemiologia , Transtornos Cognitivos/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Doença de Parkinson/epidemiologia
19.
Zhonghua Liu Xing Bing Xue Za Zhi ; 30(10): 1065-8, 2009 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-20193391

RESUMO

OBJECTIVE: To investigate the treatment status of antiparkinsonism in Xi'an. METHODS: Six general hospitals were randomly chosen in Xi'an and all Parkinson's disease (PD) patients were interviewed by questionnaire from Jan. 2007 to Apr. 2007. RESULTS: 92 PD outpatients were enrolled in, including 48 males and 44 females, from 43 to 86 years old (mean 65.6 +/- 17.1) with duration of the disease from 0.2 to 27.8 years (mean 4.4 +/- 9.4). The preference of the drug use from the patients were: 40 (43.5%) preferred taking levodopa, 25 (27.2%) with amantadine and/or trihexyphenidyl, 14 (15.2%) with levodopa and others, 4 (4.4%) with dopamine agonist and others, 2 (2.2%) with other drugs, 7 (7.6%) with no treatment. There were 69 (75.0%) patients onset with resting tremor, 15 (16.3%) with bradykinesia, 6 (6.5%) with rigidity, and 2 (2.2%) with unknown symptoms. There was no startically significant difference in anti-PD drugs among the patients onset with different symptoms (P > 0.05). 45 patients appeared the onset of disease before 65 years old and with no dementia, 47 onset after 65 with or without dementia. There was no significant difference of anti-PD drugs between the two groups (P > 0.05). Most patients initiated anti-PD treatment with levodopa but few of them chose dopamine agonist. According to the classification of Hoehn & Yahr, 25(27.2%)belonged to Grade I, 53 (57.6%) to Grade II, 8 (8.7%) to Grade III, 3 (3.3%) to Grade IV and 3 (3.3%) to Grade V. There was no significant differences of anti-PD drugs between different grades of the disease (P > 0.05). 55.3% of the patients changed their anti-PD drugs randomly during the therapy, but with no relation to their gender, age, educational level, dementia, the number of family members, course of diseases, or the degree of Hoehn & Yahr, frequency and categories of medicine. CONCLUSION: Anti-PD treatment in Xi'an did not strictly follow the standardized protocol, with few patients using dopamine agonist and over 50% of the patients changed their drugs randomly.


Assuntos
Antiparkinsonianos/uso terapêutico , Doença de Parkinson/tratamento farmacológico , Preferência do Paciente/estatística & dados numéricos , Adulto , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Amantadina/uso terapêutico , China/epidemiologia , Agonistas de Dopamina/uso terapêutico , Quimioterapia Combinada , Feminino , Humanos , Levodopa/uso terapêutico , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Inquéritos e Questionários , Triexifenidil/uso terapêutico
20.
Artigo em Chinês | MEDLINE | ID: mdl-17653304

RESUMO

OBJECTIVE: To investigate the relationship between the degree of week 24 HBV suppression and week 48 therapeutic response in entecavir-treated chronic hepatitis B patients in whom lamivudine treatment failed, so as to explore a useful predictor for efficacy of enticavir treatment. METHODS: Thirty-three patients with chronic hepatitis B refractory to lamivudine were enrolled to receive treatment with entecavir 1.0 mg once daily. The patients were divided into 4 groups according to serum HBV DNA levels (copies/mL) at week 24: PCR-undetectable (less than 300 copies/ml); QL- less than 3 log10 copies/ml; 3 log10(-4) log10 copies/ml; greater than 4 log10 copies/mL, and the efficacy achieved at week 48 was evaluated. RESULTS: At week 48, mean reductions of serum HBV DNA from baseline was 4.91 log10. HBV DNA became undetectable by PCR assay in 33.3 percent patients and ALT became normal in 75.8%. The lower the HBV DNA level achieved at week 24, the higher the proportion of patients in whom HBV DNA became undetectable by PCR and ALT normalization were acquired at week 48, and viral breakthrough at week 48 also decreased. CONCLUSION: Undetectable HBV DNA by PCR at week 24 in entecavir-treated chronic hepatitis B patients who were refractory to lamivudine, suggests a better efficacy at week 48. The degree of week 24 suppression of HBV may be used as a predictor of long term outcome.


Assuntos
Antivirais/uso terapêutico , Guanina/análogos & derivados , Vírus da Hepatite B/efeitos dos fármacos , Hepatite B Crônica/tratamento farmacológico , Lamivudina/uso terapêutico , Adolescente , Adulto , Idoso , Antivirais/farmacologia , Esquema de Medicação , Avaliação de Medicamentos , Guanina/administração & dosagem , Guanina/farmacologia , Vírus da Hepatite B/genética , Hepatite B Crônica/virologia , Humanos , Lamivudina/farmacologia , Masculino , Pessoa de Meia-Idade , Falha de Tratamento , Adulto Jovem
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