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1.
J Integr Neurosci ; 23(5): 93, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38812381

RESUMO

BACKGROUND: Magnetoencephalography (MEG) is a non-invasive imaging technique for directly measuring the external magnetic field generated from synchronously activated pyramidal neurons in the brain. The optically pumped magnetometer (OPM) is known for its less expensive, non-cryogenic, movable and user-friendly custom-design provides the potential for a change in functional neuroimaging based on MEG. METHODS: An array of OPMs covering the opposite sides of a subject's head is placed inside a magnetically shielded room (MSR) and responses evoked from the auditory cortices are measured. RESULTS: High signal-to-noise ratio auditory evoked response fields (AEFs) were detected by a wearable OPM-MEG system in a MSR, for which a flexible helmet was specially designed to minimize the sensor-to-head distance, along with a set of bi-planar coils developed for background field and gradient nulling. Neuronal current sources activated in AEF experiments were localized and the auditory cortices showed the highest activities. Performance of the hybrid optically pumped magnetometer-magnetoencephalography/electroencephalography (OPM-MEG/EEG) system was also assessed. CONCLUSIONS: The multi-channel OPM-MEG system performs well in a custom built MSR equipped with bi-planar coils and detects human AEFs with a flexible helmet. Moreover, the similarities and differences of auditory evoked potentials (AEPs) and AEFs are discussed, while the operation of OPM-MEG sensors in conjunction with EEG electrodes provides an encouraging combination for the exploration of hybrid OPM-MEG/EEG systems.


Assuntos
Córtex Auditivo , Eletroencefalografia , Potenciais Evocados Auditivos , Magnetoencefalografia , Humanos , Magnetoencefalografia/instrumentação , Potenciais Evocados Auditivos/fisiologia , Córtex Auditivo/fisiologia , Eletroencefalografia/instrumentação , Eletroencefalografia/métodos , Adulto , Masculino
2.
BMC Oral Health ; 24(1): 695, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38879477

RESUMO

BACKGROUND: The status of dental caries is closely related to changes in the oral microbiome. In this study, we compared the diversity and structure of the dental plaque microbiome in children with severe early childhood caries (S-ECC) before and after general anaesthesia and outpatient treatment. METHODS: Forty children aged 3 to 5 years with S-ECC who had completed whole-mouth dental treatment under general anaesthesia (C1) or in outpatient settings (C2) were selected, 20 in each group. The basic information and oral health status of the children were recorded, and the microbial community structure and diversity of dental plaque before treatment (C1, C2), the day after treatment(C2_0D), 7 days after treatment (C1_7D, C2_7D), 1 month after treatment (C1_1M, C2_1M), and 3 months after treatment (C1_3M, C2_3M) were analysed via 16 S rRNA high-throughput sequencing technology. RESULTS: (1) The alpha diversity test showed that the flora richness in the multiappointment group was significantly greater at posttreatment than at pretreatment (P < 0.05), and the remaining alpha diversity index did not significantly differ between the 2 groups (P > 0.05). The beta diversity analysis revealed that the flora structures of the C1_7D group and the C2_3M group were significantly different from those of the other time points within the respective groups (P < 0.05). (2) The core flora existed in both the pre- and posttreatment groups, and the proportion of their flora abundance could be altered depending on the caries status of the children in both groups. Leptotrichia abundance was significantly (P < 0.05) lower at 7 days posttreatment in both the single- and multiappointment groups. Corynebacterium and Corynebacterium_matruchotii were significantly more abundant in the C1_1M and C1_3M groups than in the C1 and C1_7D groups (P < 0.05). Streptococcus, Haemophilus and Haemophilus_parainfluenzae were significantly more abundant in the C1_7D group than in the other groups (P < 0.05). CONCLUSION: A single session of treatment under general anaesthesia can cause dramatic changes in the microbial community structure and composition within 7 days after treatment, whereas treatment over multiple appointments may cause slow changes in oral flora diversity.


Assuntos
Cárie Dentária , Placa Dentária , Humanos , Placa Dentária/microbiologia , Cárie Dentária/microbiologia , Cárie Dentária/terapia , Pré-Escolar , Masculino , Feminino , Microbiota , Anestesia Geral , RNA Ribossômico 16S
3.
BMC Womens Health ; 22(1): 46, 2022 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-35197068

RESUMO

OBJECTIVE: To investigate the effect of a web-based educational intervention on changing female college students' willingness and uptake of human papillomavirus (HPV) vaccines, and factors associated with HPV vaccination acceptance in Western and Northern China. METHODS: A web-based cluster randomized controlled trial was conducted in Western and Northern China from February to May 2020. A total of 967 female freshmen were recruited from two universities through convenience sampling, stratified sampling (liberal arts or sciences), and cluster sampling. Eligible students were randomized into intervention and control group with a 1:1 allocation ratio. The intervention group received seven days of web-based health education regarding HPV and HPV vaccines, whereas the control group received non-HPV-related materials. All students were asked to complete a post-intervention questionnaire to measure their awareness, uptake, and willingness to receive HPV vaccination at 7-day and one-month intervals. The chi-square test and Student's t-test were employed to examine the differences between the intervention and control groups for categorical and continuous data. Logistic regressions were used to analyze factors associated with vaccination intentions. RESULTS: Nine hundred forty-six female freshmen aged 18.99 ± 0.63 years were enrolled in the study, with 532 in the intervention group and 414 in the control group. Prior to the intervention, 63.8%, 66.3%, and 60.8% of students had heard of HPV, HPV-related diseases, and HPV vaccines, respectively. Only 2.2% of students reported being vaccinated, but 33.0% were willing to be vaccinated against HPV. After seven days of education, students in the intervention group exhibited higher awareness (p < 0.001) and knowledge scores (5.13 ± 1.23 vs. 3.10 ± 1.99, p < 0.001) than those in the control group. Similarly, in the intervention groups, willingness to be vaccinated against HPV was significantly higher than in the control groups (p < 0.001). The high cost (57.7%) and concerns about adverse events (56.0%) were the main reasons female college students did not accept HPV vaccines. School location in urban areas, parents' higher education backgrounds, history of HPV vaccination counseling, history of sexual behavior, and having heard of HPV vaccines were associated with a higher willingness to be vaccinated. CONCLUSION: Female college students' HPV vaccination uptake is insufficient, and they have minimal detailed knowledge about HPV and its vaccines. Web-based health education on HPV vaccines is an easy, feasible, and effective way to improve the awareness and acceptance of HPV vaccination among female college students, but it has limited effect on HPV vaccination uptake.


Assuntos
Infecções por Papillomavirus , Vacinas contra Papillomavirus , China , Feminino , Seguimentos , Educação em Saúde , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Internet , Papillomaviridae , Infecções por Papillomavirus/prevenção & controle , Vacinas contra Papillomavirus/uso terapêutico , Aceitação pelo Paciente de Cuidados de Saúde , Estudantes , Inquéritos e Questionários , Vacinação
4.
Eur J Oral Sci ; 126(1): 1-12, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29148101

RESUMO

Homeobox protein MSX-1 (hereafter referred to as MSX-1) is essential for early tooth-germ development. Tooth-germ development is arrested at bud stage in Msx1 knockout mice, which prompted us to study the functions of MSX-1 beyond this stage. Here, we investigated the roles of MSX-1 during late bell stage. Mesenchymal cells of the mandibular first molar were isolated from mice at embryonic day (E)17.5 and cultured in vitro. We determined the expression levels of ß-catenin, bone morphogenetic protein 2 (Bmp2), Bmp4, and lymphoid enhancer-binding factor 1 (Lef1) after knockdown or overexpression of Msx1. Our findings suggest that knockdown of Msx1 promoted expression of Bmp2, Bmp4, and Lef1, resulting in elevated differentiation of odontoblasts, which was rescued by blocking the expression of these genes. In contrast, overexpression of Msx1 decreased the expression of Bmp2, Bmp4, and Lef1, leading to a reduction in odontoblast differentiation. The regulation of Bmp2, Bmp4, and Lef1 by Msx1 was mediated by the Wnt/ß-catenin signaling pathway. Additionally, knockdown of Msx1 impaired cell proliferation and slowed S-phase progression, while overexpression of Msx1 also impaired cell proliferation and prolonged G1-phase progression. We therefore conclude that MSX-1 maintains cell proliferation by regulating transition of cells from G1-phase to S-phase and prevents odontoblast differentiation by inhibiting expression of Bmp2, Bmp4, and Lef1 at the late bell stage via the Wnt/ß-catenin signaling pathway.


Assuntos
Proteína Morfogenética Óssea 2/metabolismo , Proteína Morfogenética Óssea 4/metabolismo , Diferenciação Celular/fisiologia , Fator 1 de Ligação ao Facilitador Linfoide/metabolismo , Fator de Transcrição MSX1/fisiologia , Células-Tronco Mesenquimais/metabolismo , Odontogênese/fisiologia , Germe de Dente/citologia , Animais , Feminino , Feto , Citometria de Fluxo , Técnicas In Vitro , Camundongos , Camundongos Endogâmicos ICR , Gravidez , Via de Sinalização Wnt/fisiologia , beta Catenina/metabolismo
5.
Environ Sci Pollut Res Int ; 31(9): 13609-13621, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38253838

RESUMO

Cladophora rupestris is ubiquitous in many kinds of waterbodies, and C. rupestris biomass can serve as a carrier for adsorbing and transferring heavy metals. Batch experiments and characterization were performed. Results showed that the organic frameworks of C. rupestris (CROF) had a specific surface area of 2.58 m2/g and an external surface area of 2.06 m2/g. Many mesopores were present in CROF, mainly distributed in 2.5-7.5 nm. The zeta potentials were within the range of - 4.46 to - 13.98 mV in the tested pH of 2.0-9.0. CROF could effectively adsorb Pb2+ in large pH range. The maximum adsorption capacity (qmax) of Pb2+ on CROF was 15.02 mg/g, and 97% of Pb2+ was adsorbed onto CROF after 25 min. CROF had a preferential adsorption of Pb2+. The protein secondary structures and carbon skeletons of CROF all worked in adsorption. The main Pb2+ adsorption mechanisms were pore filling, electrostatic attraction, Pb-π interaction, and surface complexation. Therefore, it is valuable as a biosorbent for the removal of Pb2+ from waterbodies.


Assuntos
Clorófitas , Metais Pesados , Poluentes Químicos da Água , Chumbo , Metais Pesados/química , Física , Cinética , Adsorção , Concentração de Íons de Hidrogênio , Poluentes Químicos da Água/análise
6.
Eur J Oral Sci ; 121(5): 412-20, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24028588

RESUMO

The homeobox, msh-like 1 (MSX1) protein is essential for cell proliferation and differentiation. Tooth germ development of Msx1 knockout mouse is arrested at the bud stage, impeding an understanding of its role beyond this stage of tooth development. The aims of this study were to investigate the potential role of MSX1 in the regulation of proliferation and differentiation of dental mesenchymal cells in culture, and to preliminarily explore its underlying mechanism of action. Tooth germs were isolated from embryonic day (E)15.5 mice. The mesenchyme was separated and digested into a single-cell suspension, and then cultured in vitro. Isolated dental mesenchymal cells were transfected with MSX1 small interfering RNA, and the effects on cell proliferation, cell cycle distribution, and the expression of bone morphogenetic protein 2 (Bmp2) and bone morphogenetic protein 4 (Bmp4) were studied. We also compared the expression levels of alkaline phosphatase (Alp), type I collagen (Col1A), osteocalcin (Ocn), runt-related transcription factor 2 (Runx2), dentin sialophosphoprotein (Dspp) and dentin matrix protein 1 (Dmp1), and mineralized nodule formation, between control and MSX1 siRNA-transfected groups after the induction of odontoblast differentiation. Knockdown of Msx1 expression was associated with decreased cell proliferation, prolonged time in the S phase of the cell cycle, enhanced odontoblast differentiation, and elevated Bmp2 and Bmp4 expression. We conclude that MSX1 may promote proliferation and prevent the differentiation of dental mesenchymal cells by the inhibition of Bmp2 and Bmp4 expression.


Assuntos
Diferenciação Celular/genética , Fator de Transcrição MSX1/genética , Células-Tronco Mesenquimais/metabolismo , Mesoderma/citologia , Odontoblastos/citologia , Odontogênese/genética , Germe de Dente/citologia , Animais , Proteína Morfogenética Óssea 2/metabolismo , Proteína Morfogenética Óssea 4/metabolismo , Proliferação de Células , Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Fator de Transcrição MSX1/metabolismo , Mesoderma/metabolismo , Camundongos , Camundongos Knockout , Odontoblastos/metabolismo , RNA/isolamento & purificação , RNA Interferente Pequeno/metabolismo , Germe de Dente/metabolismo
7.
Dent Traumatol ; 29(5): 365-71, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23067388

RESUMO

BACKGROUND/AIM: The purpose of this study was to compare the effect of skimmed pasteurized milk and Hank's balanced salt solution on the viability and osteogenic differentiation potential of the human periodontal ligament stem cells at room temperature in vitro. MATERIAL AND METHODS: Human periodontal ligament stem cells were obtained from extracted healthy third molars and conserved in skimmed pasteurized milk and Hank's balanced salt solution for 1, 2, and 4 h at room temperature to detect the viability of the cells and their osteogenic differentiation potential. RESULTS: The efficacy of skimmed pasteurized milk on cell viability at 4 h was significantly higher than that of HBSS (P < 0.05), and cells stored in skimmed pasteurized milk showed significantly higher levels of mineralization than those in HBSS at 2 and 4 h (P < 0.05). CONCLUSIONS: Skimmed pasteurized milk was more effective than Hank's balanced salt solution in maintaining the viability and osteogenic differentiation potential of PDLSCs at room temperature in vitro.


Assuntos
Diferenciação Celular , Soluções Isotônicas , Leite , Osteogênese , Ligamento Periodontal/citologia , Células-Tronco/citologia , Animais , Sequência de Bases , Células Cultivadas , Primers do DNA , Humanos , Ligamento Periodontal/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sincalida/metabolismo , Células-Tronco/metabolismo
8.
Asian J Androl ; 25(2): 152-157, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36629160

RESUMO

Chromodomain-helicase-DNA-binding protein 1 (CHD1) deletion is among the most common mutations in prostate cancer (PCa), but its role remains unclear. In this study, RNA sequencing was conducted in PCa cells after clustered regularly interspaced palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9)-based CHD1 knockout. Gene set enrichment analysis (GSEA) indicated upregulation of hypoxia-related pathways. A subsequent study confirmed that CHD1 deletion significantly upregulated hypoxia-inducible factor 1α (HIF1α) expression. Mechanistic investigation revealed that CHD1 deletion upregulated HIF1α by transcriptionally downregulating prolyl hydroxylase domain protein 2 (PHD2), a prolyl hydroxylase catalyzing the hydroxylation of HIF1α and thus promoting its degradation by the E3 ligase von Hippel-Lindau tumor suppressor (VHL). Functional analysis showed that CHD1 deletion promoted angiogenesis and glycolysis, possibly through HIF1α target genes. Taken together, these findings indicate that CHD1 deletion enhances HIF1α expression through PHD2 downregulation and therefore promotes angiogenesis and metabolic reprogramming in PCa.


Assuntos
Neoplasias da Próstata , Proteína Supressora de Tumor Von Hippel-Lindau , Masculino , Humanos , Proteína Supressora de Tumor Von Hippel-Lindau/genética , Proteína Supressora de Tumor Von Hippel-Lindau/metabolismo , Proteínas de Ligação a DNA/metabolismo , Prolil Hidroxilases/metabolismo , Hipóxia , Neoplasias da Próstata/patologia , Glicólise , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Linhagem Celular Tumoral , DNA Helicases/metabolismo
9.
World J Clin Cases ; 10(26): 9524-9535, 2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36159441

RESUMO

BACKGROUND: Sulfonylurea (SU) is a commonly used antidiabetic drugs effective for type 2 diabetes mellitus. Previous studies have reported that the SU treatment could alter the serum free fatty acid (FFA) concentration in diabetic patients; however, their exact effects remain unknown. AIM: To assess the impact of SU on the FFA level in diabetic patients. METHODS: A systematic literature search was conducted by consulting the PubMed, EMBASE, Cochrane Library, Reference Citation Analysis (https://www.referencecitationanalysis.com/), and Web of Science databases from January 1, 1991 to July 30, 2021. Either a fixed-effects model or random-effects model was applied to study the association between SU treatment and FFA concentration according to the heterogeneity test. Two investigators independently performed data extraction. The mean difference (MD) and corresponding 95% confidence interval (CI) were used to measure effect size. R3.5.1 software was utilized for conducting statistical analyses. RESULTS: A total of 13 studies with 2273 individuals were selected. Results indicated that FFA concentration increased slightly after treatment with SU (MD = 0.08, 95%CI: 0.03-0.12, P < 0.01). In addition, we found that SU treatment combined with other antidiabetics could also increase the concentration of serum FFA (MD = 0.14, 95%CI: 0.01-0.28, P < 0.01). Regarding the type of SU, there was no significant difference in FFA concentration with glimepiride or glibenclamide. FFA concentration was higher at ≥ 12 wk (MD = 0.09, 95%CI: 0.04-0.13) but not at < 12 wk (MD = 0.01, 95%CI: -0.07-0.09). CONCLUSION: SU treatment could increase the serum FFA concentration in diabetic patients. The fundamental underlying mechanism still needs further investigation.

10.
Mitochondrial DNA B Resour ; 6(9): 2601-2604, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34409154

RESUMO

This study determined the mitochondrial genome (mitogenome) of Chanodichthys mongolicus from China's Qiantang River and analyzed its phylogenetic history in the Subfamily Cultrinae. Next-generation sequencing was used to obtain the mitogenome of C. mongolicus, GenBank Accession Number MZ032228. The mitochondrial genome length of C. mongolicus from China's Qiantang River is 16,622 bp. The genome contains 13 protein-coding genes, 22 transfer RNAs, two ribosomal RNAs, and two central noncoding regions (the control region and the origin of light strand replication). Based on BLAST comparisons, the sequence identity of C. mongolicus MZ032228 from China's Qiantang River was 99.84% to that of Ancherythroculter wangi MG783573 from China's Nei River, 99.75% to C. mongolicus AP009060 from Russia's Black River. The phylogenetic analysis is consistent with BLAST comparisons in confirming that A. wangi MG783573 and C. mongolicus MZ032228 show a high genetic similarity. This study also confirms mitochondrial DNA heteroplasmy in C. mongolicus for the first time and documents 35 heterogeneous loci that were detected.

11.
Int J Biol Markers ; 25(2): 93-8, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20586028

RESUMO

OBJECTIVES: To determine the concentrations of SCCA, Cyfra 21-1, EGFR and Cyclin D1 in serum of patients with oral squamous cell carcinoma, and investigate their diagnostic value and their relationship with clinical stage, histological differentiation and lymph node metastasis. METHODS: Seventy hospitalized patients with oral squamous cell carcinoma and 72 healthy individuals were included in the study. Venous blood was collected from all study participants, in the oral carcinoma patients before tumor resection. One week after surgery, venous blood was collected again from 20 patients. Serum marker levels were determined by enzymelinked immunosorbent assay (ELISA). RESULTS: The serum SCCA, EGFR and Cyclin D1 concentrations were significantly higher in patients with oral squamous cell carcinoma than in healthy controls, while there was no significant difference in Cyfra 21-1 levels between patients and controls. The serum SCCA concentration decreased after surgery, but there was no significant difference in the serum Cyfra 21-1, EGFR and Cyclin D1 concentrations before and after surgery. Serum SCCA, Cyfra 21-1, EGFR and Cyclin D1 concentrations were not correlated with clinical stage, histological differentiation and lymph node metastasis. When SCCA, EGFR and Cyclin D1 were measured separately, EGFR had the highest diagnostic sensitivity and accuracy and Cyclin D1 had the highest specificity; when any two of the markers were tested in combination, the combined detection of EGFR and Cyclin D1 had the highest sensitivity, specificity and accuracy. CONCLUSIONS: SCCA, EGFR and Cyclin D1 may prove to be useful tumor markers in oral squamous cell carcinoma. The combined determination of EGFR and Cyclin D1 may be of value in the diagnosis of oral squamous cell carcinoma. Serum SCCA may be used as an adjunct in monitoring treatment response.


Assuntos
Antígenos de Neoplasias/sangue , Carcinoma de Células Escamosas/sangue , Ciclina D1/sangue , Receptores ErbB/sangue , Queratina-19/sangue , Neoplasias Bucais/sangue , Serpinas/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos de Neoplasias/análise , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/cirurgia , Estudos de Casos e Controles , Ciclina D1/análise , Receptores ErbB/análise , Feminino , Humanos , Queratina-19/análise , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/diagnóstico , Neoplasias Bucais/patologia , Neoplasias Bucais/cirurgia , Esvaziamento Cervical/reabilitação , Estadiamento de Neoplasias , Prognóstico , Serpinas/análise
12.
Mitochondrial DNA B Resour ; 5(1): 841-842, 2020 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-33366776

RESUMO

In this study, we determined the complete mitochondrial DNA sequence of the hybrid of Megalobrama terminalis(♀) × Culter alburnus(♂) for the first time. The complete mitochondrial genome of the hybrid was sequenced to be 16,621 bp in size following the female parent, M. terminalis. The genome contained 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and 2 main non-coding regions (the control region and the origin of light strand replication). Sequence alignment between the mitochondrial genomes of the hybrid and its female parent showed that a total of 28 mutation sites were identified in 14 genes or regions. The genome information presented here may play an important role in further study on the genetic mechanisms of mitochondrial DNA in hybrids.

13.
Mitochondrial DNA B Resour ; 5(3): 2316-2317, 2020 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-33457773

RESUMO

In this study, we determined the complete mitochondrial DNA sequence of the hybrid of Culter alburnus (♀) x Megalobrama terminalis (♂) for the first time. The complete mitochondrial genome of the hybrid was sequenced to be 16,622 bp in size following the female parent, C. alburnus. The genome contained 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and two main non-coding regions (the control region and the origin of light strand replication). Sequence alignment between the mitochondrial genomes of the hybrid and its female parent showed that a total of 35 mutation sites were identified in 14 genes or regions. The genome information presented here may play an important role in further study on the genetic mechanisms of mitochondrial DNA in hybrids.

14.
Ying Yong Sheng Tai Xue Bao ; 29(7): 2433-2444, 2018 Jul.
Artigo em Zh | MEDLINE | ID: mdl-30039683

RESUMO

Robinia pseudoacacia has been widely planted in the Loess Plateau of China for soil and water conservation. The growth decline of R. pseudoacacia plantations has become a recently emerging challenge for the revegetation program and sustainable forest management in this region. As to the scientific definition, identified criteria and quantitative indices have not yet been comprehensively quantified, our current understanding of the ecological and physiological mechanisms for growth decline of R. pseudoacacia plantations is limited. The knowledge could enrich the basic theories of vegetation restoration and benefit the sustainable development of the afforestation project in the Loess Plateau. Through the comprehensive compilation of literatures on forest decline and tree mortality in the Loess Plateau and other regions across the world, this review summarized the mechanisms and recent research progress on growth decline for R. pseudoacacia plantations in the Loess Plateau, primarily demonstrated from ecological (e.g., climatic change, soil desiccation, the imbalance of community structure and the misconduct of forest management) and physiological (e.g., hydraulic failure, carbon starvation, genetic and molecular regulation) perspectives. Finally, we highlighted the research gap with regard to growth decline of R. pseudoacacia plantations in the Loess Plateau.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Robinia/fisiologia , Carbono , China , Florestas , Robinia/crescimento & desenvolvimento , Solo
15.
Appl Biochem Biotechnol ; 165(7-8): 1754-69, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21947763

RESUMO

Marine-derived fungi are prone to produce structurally unique secondary metabolites, a considerable number of which display the promising biological properties and/or industrial applications. Among those, ligninolytic enzymes have attracted great interest in recent years. In this work, about 20 strains were isolated from sea mud samples collected in the East China Sea and then screened for their capacity to produce lignin-degrading enzymes. The results showed that a strain, named J63, had a great potential to secrete a considerable amount of laccase. Using molecular method, it was identified as an endophytic fungus, Pestalotiopsis sp. which was rarely reported as ligninolytic enzyme producer in the literature. The production of laccase by Pestalotiopsis sp. J63 was investigated under submerged fermentation (SF) and solid state fermentation (SSF) with various lignocellulosic by-products as substrates. The SSF of rice straw powder accumulated the highest level of laccase activity (10,700 IU/g substrate), whereas the SF of untreated sugarcane bagasse provided the maximum amount of laccase activity (2,000 IU/ml). The value was far higher than those reported by other reports. In addition, it produced 0.11 U/ml cellulase when alkaline-pretreated sugarcane bagasse was used as growth substrate under SF. Meanwhile, the growth of fungi and laccase production under different salinity conditions were also studied. It appeared to be a moderately halo-tolerant organism.


Assuntos
Proteínas Fúngicas/metabolismo , Fungos/enzimologia , Lacase/metabolismo , Lignina/metabolismo , Água do Mar/microbiologia , China , Estabilidade Enzimática , Proteínas Fúngicas/química , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Lacase/química , Dados de Sequência Molecular , Filogenia
16.
Dongwuxue Yanjiu ; 32(4): 363-70, 2011 Aug.
Artigo em Zh | MEDLINE | ID: mdl-21842531

RESUMO

Genetic diversity and genetic structure of 7 wild stocks of oriental river prawn Macrobrachium nipponense in Qiantang River, i.e. Wen-yan, Fu-yang, Chang-kou, Tong-lu, Xin-an-jiang, She-xian and Xiu-ning, were investigated using 10 microsatellite DNA markers. The result showed that all the 10 loci were highly polymorphic. There was a trend that the level of genetic diversity of wild stocks in downstream and midstream were higher than the upstream ones'. Sign test and Wilcoxon sign rank test results showed that the stocks in Qiantang River had no bottleneck effect, and the number of stocks had not declined recently. F(ST) among stocks ranged from 0.0201 to 0.1069. Analysis of molecular variance (AMOVA) revealed that a higher portion (93.48%) of variations existed within individuals, while lower portion (6.52%) existed among stocks. F(ST) and AMOVA analysis across all stocks and loci indicated the medium level of divergence among the stocks. The NJ clustering tree based on D(A) genetic distance demonstrated that the stocks of adjacent geographical position clustered together. 413 individuals obtained from six wild stocks could be divided into two potential populations based on the genetic structure. This study demonstrated that genetic diversity and genetic structure of M. nipponense stocks were relevant to geographical position where they survived.


Assuntos
Organismos Aquáticos/genética , Variação Genética , Repetições de Microssatélites , Palaemonidae/genética , Animais , Organismos Aquáticos/isolamento & purificação , China , Dados de Sequência Molecular , Palaemonidae/classificação , Filogenia
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