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1.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 59(10): 977-987, 2024 Oct 09.
Artigo em Chinês | MEDLINE | ID: mdl-39344448

RESUMO

Temporomandibular joint (TMJ) diseases are common clinical conditions. The number of patients with TMJ diseases is large, and the etiology, epidemiology, disease spectrum, and treatment of the disease remain controversial and unknown. To understand and master the current situation of the occurrence, development and prevention of TMJ diseases, as well as to identify the patterns in etiology, incidence, drug sensitivity, and prognosis is crucial for alleviating patients'suffering.This will facilitate in-depth medical research, effective disease prevention measures, and the formulation of corresponding health policies. Cohort construction and research has an irreplaceable role in precise disease prevention and significant improvement in diagnosis and treatment levels. Large-scale cohort studies are needed to explore the relationship between potential risk factors and outcomes of TMJ diseases, and to observe disease prognoses through long-term follw-ups. The consensus aims to establish a standard conceptual frame work for a cohort study on patients with TMJ disease while providing ideas for cohort data standards to this condition. TMJ disease cohort data consists of both common data standards applicable to all specific disease cohorts as well as disease-specific data standards. Common data were available for each specific disease cohort. By integrating different cohort research resources, standard problems or study variables can be unified. Long-term follow-up can be performed using consistent definitions and criteria across different projects for better core data collection. It is hoped that this consensus will be facilitate the development cohort studies of TMJ diseases.


Assuntos
Controle de Qualidade , Transtornos da Articulação Temporomandibular , Transtornos da Articulação Temporomandibular/terapia , Transtornos da Articulação Temporomandibular/diagnóstico , Humanos , Estudos de Coortes , Consenso
2.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 57(10): 1057-1064, 2022 Oct 09.
Artigo em Chinês | MEDLINE | ID: mdl-36266080

RESUMO

Objective: To explore the pathological characteristics of three mice models of temporomandibular joint degenerative joint disease (TMJDJD), including osteoarthritis and osteoarthrosis, and to provide references for animal experimental study regarding the pathological mechanism of osteoarthritis and osteoarthrosis. Methods: A total of 54 8-week-old male C57BL/6 mice were selected to construct three TMJDJD animal models, including bilateral temporomandibular joint (TMJ) Freund's complete adjuvant (FCA) injection model, bilateral TMJ monosodium iodoacetate (MIA) injection model, and right TMJ discectomy model. FCA injection model (15 mice) was divided into saline injection group, FCA injection group-1 week, FCA injection group-2 week, FCA injection group-4 week and FCA injection group-6 week, 3 mice were used at each time point, with a total of 6 TMJs on both sides. MIA injection model (15 mice) was separated into saline injection group, MIA injection group-1 week, MIA injection group-2 week, MIA injection group-4 week and MIA injection group-6 week, 3 mice were used at each time point, with a total of 6 TMJs on both sides. TMJ discectomy model (24 mice) was split into control group, discectomy group-2 week group, discectomy group-4 week and discectomy group-6 week, six mice were used at each time point, with a total of six right TMJs. General pictures of the bilateral joints area of mice were collected 1 day after drug injection, and stereoscopic images of condylar tissues were collected 4 weeks after microsurgery for discectomy. Mouse TMJ tissue sections from each time point were stained with HE and toluidine blue, respectively, synovial tissues were scored for synovial inflammation, and the percentage of proteoglycan in condylar cartilage was quantitatively analyzed. Results: One day after intra-articular FCA or MIA injection, the width of bilateral TMJ were significantly increased in FCA injection groups [(24.60±0.46) mm] compared with the saline injection group [(21.63±0.52) mm] (t=4.25, P<0.013), the width of bilateral TMJ in MIA injection groups [(24.50±0.62) mm] were also significantly higher than that in saline injection group [(21.40±0.52) mm] (t=3.82, P=0.019). The synovitis scores in FCA injection groups 1, 2, 4, 6 weeks after FCA injection were significantly higher than that of the saline injection group (F=18.09, P<0.001), with the proteoglycan of condylar cartilage increased firstly and then decreased compared with the saline injection group (F=21.59, P<0.001). Condylar cartilage proteoglycan loss in different degrees were observed 1, 2, 4 and 6 weeks after MIA injection (F=13.59, P<0.001), and synovitis scores were increased at different degrees compared with saline injection group (F=14.79, P<0.001). The morphology of condylar cartilage in discectomy groups mice were severely damaged, synovial tissues showed dense connective tissue lesions at 2, 4 and 6 weeks postoperatively, condylar cartilage tissues showed a time-dependent loss of proteoglycan compared with the control group (F=40.62, P<0.001). Conclusions: Intra-articular FCA injection establishes a mouse model of TMJ osteoarthritis with severe synovial inflammation. Intra-articular MIA injection constructs a mouse model of typical TMJ osteoarthritis. Discectomy establishes a mouse TMJ osteoarthrosis model with severe condylar cartilage destruction.


Assuntos
Cartilagem Articular , Osteoartrite , Sinovite , Camundongos , Masculino , Animais , Osteoartrite/patologia , Ácido Iodoacético , Cloreto de Tolônio , Camundongos Endogâmicos C57BL , Articulação Temporomandibular/patologia , Modelos Animais de Doenças , Proteoglicanas , Sinovite/patologia , Inflamação/patologia
3.
Phys Rev Lett ; 128(8): 085003, 2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-35275672

RESUMO

High-ß_{θe} (a ratio of the electron thermal pressure to the poloidal magnetic pressure) steady-state long-pulse plasmas with steep central electron temperature gradient are achieved in the Experimental Advanced Superconducting Tokamak. An intrinsic current is observed to be modulated by turbulence driven by the electron temperature gradient. This turbulent current is generated in the countercurrent direction and can reach a maximum ratio of 25% of the bootstrap current. Gyrokinetic simulations and experimental observations indicate that the turbulence is the electron temperature gradient mode (ETG). The dominant mechanism for the turbulent current generation is due to the divergence of ETG-driven residual flux of current. Good agreement has been found between experiments and theory for the critical value of the electron temperature gradient triggering ETG and for the level of the turbulent current. The maximum values of turbulent current and electron temperature gradient lead to the destabilization of an m/n=1/1 kink mode, which by counteraction reduces the turbulence level (m and n are the poloidal and toroidal mode number, respectively). These observations suggest that the self-regulation system including turbulence, turbulent current, and kink mode is a contributing mechanism for sustaining the steady-state long-pulse high-ß_{θe} regime.

4.
Zhonghua Liu Xing Bing Xue Za Zhi ; 42(7): 1260-1265, 2021 Jul 10.
Artigo em Chinês | MEDLINE | ID: mdl-34814541

RESUMO

Objective: To understand the characteristics of the HIV-1 molecular networks in injected drug users (IDUs) in Guangzhou from 2008 to 2017, and provide reference for the prevention and control of AIDS in this population. Methods: The serum samples of newly diagnosed HIV-1 positive IDUs in Guangzhou from 2008 to 2017 were collected, HIV-1 RNA was extracted for pol gene amplification and sequencing. The molecular cluster in the phylogenetic tree was identified by Cluster Picker 1.2.3 for cluster analysis. TN93 model in HyPhy2.2.4 was used to calculate the gene distance between the cluster sequences. Software Cytoscape3.8.2 was used to visualize the molecular network, and χ2 test or exact probability method was used for cluster analysis and centrality analysis. Results: A total of 586 sequences were successfully amplified (73.9%, 586/793), and 80 molecular clusters were produced, with a clustering rate of 46.6% (273/586). In molecular clusters, the proportions of the strains from IDUs in Han ethnic group (48.4%, 260/537), IDUs who were local residents in Guangdong (52.7%, 146/277) and IDUs whose strain sequence subtype was CRF55_01B (93.3%, 14/15) were higher. In the molecular network, the degree range was 1-7, and nodes with degree ≥3 accounted for 12.8% (24/187), which was associated with another 81 nodes in the molecular network (43.3%, 81/187). The centrality analysis showed that the proportions of housework/unemployed with high degree centrality (19.0%, 19/100), high intermediary (22.0%, 22/100), and high proximity centrality (32.0%, 32/100) were higher in IDUs infected with HIV-1. Conclusion: The risk of HIV-1 clustering in IDUs in Guangzhou was high, suggesting that IDUs who were from both Guangdong and Guangxi and were house workers or unemployed should be viewed as the key targets, and precise intervention should be implemented to reduce the HIV-1 infection rate in this population.


Assuntos
Usuários de Drogas , HIV-1 , China/epidemiologia , Genótipo , HIV-1/genética , Humanos , Filogenia
5.
Trials ; 22(1): 228, 2021 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-33757568

RESUMO

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease characterized by coughing, the production of excess sputum, and dyspnea. Patients with excessively thick sputum may have frequent attacks or develop more serious disease. The guidelines recommend airway clearance for patients with excessive sputum who are hospitalized with COPD. The active cycle of breathing technique is the most common non-pharmacological airway clearance technique used by physiotherapists. However, the effectiveness of the technique is not always guaranteed. Active cycle of breathing techniques require the initial dilution of the sputum, usually by inhalation drugs, which may have limited effects. Recent studies have found that phonophoresis decreases inflammation, suggesting the potential of the combined usage of active cycle of breathing techniques and phonophoresis. Therefore, the aim of this study is to explore the effectiveness and safety of combining active cycle of breathing technique and phonophoresis in treating COPD patients. METHODS AND ANALYSIS: We propose a single-blind randomized controlled trial using 75 hospitalized patients diagnosed with COPD with excessive sputum production. The patients will be divided into three groups. The intervention group will receive active cycle of breathing techniques combined with phonophoresis. The two comparison groups will be treated with active cycle of breathing techniques and phonophoresis, respectively. The program will be implemented daily for 1 week. The primary outcomes will be changes in sputum viscosity and production, lung function, and pulse oximetry. Secondary outcomes include the assessment of COPD and anxiety, measured by the COPD Assessment Test scale and the Anxiety Inventory for Respiratory Disease, respectively; self-satisfaction; the degree of cooperation; and the length of hospital stay. All outcome measures, with the exception of sputum production and additional secondary outcomes, will be assessed at the commencement of the study and after 1 week's intervention. Analysis of variance will be used to investigate differences between the groups, and a p-value of less than 0.05 (two-tailed) will be considered statistically significant. DISCUSSION: This study introduces a combination of active cycle of breathing techniques and phonophoresis to explore the impact of these interventions on patients hospitalized with COPD. If this combined intervention is shown to be effective, it may prove to be a better treatment for patients with COPD. TRIAL REGISTRATION: The trial was registered prospectively on the Chinese Clinical Trial Registry on 24 December 2019.ClinicalTrials.gov ChiCTR1900028506 . Registered on December 2019.


Assuntos
Fonoforese , Doença Pulmonar Obstrutiva Crônica , Dispneia , Humanos , Pulmão , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/terapia , Ensaios Clínicos Controlados Aleatórios como Assunto , Método Simples-Cego
6.
Int J Nurs Stud ; 117: 103880, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33540180

RESUMO

BACKGROUND: While active cycle of breathing technique for chronic obstructive pulmonary disease patients with more sputum can improve clinic outcomes, less is known about sputum viscosity and sputum production of the intervention. OBJECTIVE: The purpose of our study was to explore the effect of active cycle of breathing technique on sputum viscosity and production among patients with chronic obstructive pulmonary disease. DESIGN: This was a two-arms, parallel, randomized clinical trial. SETTING: Study enrollment, randomization and implementation were conducted in the department of respiratory medicine inpatient at the Medical Center in Changchun, China. PARTICIPANTS: Hospitalized patients due to chronic obstructive pulmonary disease who met additional eligibility criteria were randomized to active cycle of breathing technique (n = 50) or usual care group (n = 50). METHODS: Patients in the intervention group received a week-long intervention from an experienced physical therapist. Patients in the usual care group received usual care as well as information and advice in the light of their health plan from respiratory medicine. The primary outcome was the changes on sputum viscosity and production. RESULTS: Among one hundred patients who were randomized (mean [SD] age, 54.89 [12.06] years; females, 58%), ninety-six participants completed the study. No significant differences were found between two groups on the changes of sputum viscosity (t = 0.277, P = 0.782). And there were insignificant differences between groups in the average amount of sputum among 1 h (Z=-1.848, P = 0.065) and significant differences in the average amount of sputum among 24 h (Z=-2.236, P = 0.025). From admission to one week recovery, the changes in ratio of forced expiratory volume in 1 s to forced vital capacity (Z=-4.511, P<0.0001) and arterial oxygen saturation (Z=-2.997, P = 0.003) were better in active cycle breathing technique group. Total Chronic Obstructive Pulmonary Disease Assessment Test scale were similar among two groups (Z=-1.818, P = 0.069). No adverse events occurred during the study. CONCLUSION: For patients with chronic obstructive pulmonary disease, active cycle of breathing technique can significantly result in sputum production and respiratory function, especially those of Global Initiative for Chronic Obstructive Lung Disease classification level 3, but did not result in the short-term improvement of sputum viscosity, quality of life and cost effectiveness. Registration number: ChiCTR2000033068.


Assuntos
Doença Pulmonar Obstrutiva Crônica , Qualidade de Vida , China , Feminino , Hospitalização , Humanos , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/terapia , Testes de Função Respiratória
7.
Zhonghua Liu Xing Bing Xue Za Zhi ; 41(11): 1905-1908, 2020 Nov 10.
Artigo em Chinês | MEDLINE | ID: mdl-33297659

RESUMO

Objective: To analyze the epidemiological and molecular characteristics of human brucellosis in Qinghai province from 2005 to 2019 and provide basic data for brucellosis prevention and control. Method: The data about human brucellosis in Qinghai from 2005 to 2019 were collected from the information system of China CDC to describe the spatial, population and time distributions of human brucellosis cases in Qinghai. The isolated strains were identified and typed with traditional methods, BCSP31-PCR, AMOS-PCR and multi-locus variablenumber tandem repeat (MLVA-16). Results: A total of 577 human brucellosis cases were reported in Qinghai from 2005 to 2019, the average prevalence rate was 0.07 per 100 000 person, there were statistic differences among different years. The disease occurred all the year around, but mainly during March-October. The 577 cases were distributed in 31 counties (cities/districts) from 6 autonomous prefectures (cities). The prevalence rats of five counties were high, i.e. Menyuan Hui autonomous county (22.88%, 132/577), Tianjun county (10.57%, 61/577)、Xining city (10.57%, 61/577), Henan Mongol Autonomous County (10.51%, 58/577) and Haiyan county (9.53%, 55/577). Age of the cases ranged from 8 years to 82 years, and the male to female ratio of the cases was 1.8∶1 (374/203). The prevalence rate in herdsman (47.83%, 276/577) was highest among different occupational populations. Ten isolates were all Brucella melitensis strains, belonging to biovar 3, and clustering analysis indicated that the 10 strains had 5 genotypes, in which 2 were distinct, the remaining 3 were same. MLVA-16 analysis indicated that the 10 strains had close relationship with 26 B. melitensis strains isolated in Qinghai previously. Conclusions: The prevalence of brucellosis increased in Qinghai in recent years, we should strengthen the population based brucellosis surveillance and reporting. MLVA-16 indicated the gene diversity of the Brucella strains, suggesting that MLVA-16 can be used for genetic diversity analysis and molecular epidemiology survey to improve brucellosis surveillance.


Assuntos
Brucelose , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Brucella melitensis/genética , Brucella melitensis/isolamento & purificação , Brucelose/epidemiologia , Brucelose/microbiologia , Criança , China/epidemiologia , Cidades/epidemiologia , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
8.
Zhonghua Liu Xing Bing Xue Za Zhi ; 40(2): 196-201, 2019 Feb 10.
Artigo em Chinês | MEDLINE | ID: mdl-30744272

RESUMO

Objective: To understand the prevalence of drug resistance in treatment-naive injecting drug users (IDUs) infected with HIV-1 in Guangzhou. Methods: HIV-1 RNA were extracted from the serum specimens of the newly confirmed HIV-1 positive IDUs living in Guangzhou, being infected through injecting drug use and receiving no antiretroviral therapy at the time of confirmation during 2008-2015. Full sequence of pol protease (PR) gene and partial sequence of reverse transcriptase (RT) gene were amplified by nested reverse transcription polymerase chain reaction (nested-PCR) and sequenced. After that, data were submitted to the HIV resistance database of Stanford University for drug resistance analysis. Results: Among the 518 HIV-1 infected IDUs, HIV-1pol gene segments were successfully obtained from the serum samples of 407 HIV-1 infected IDUs (78.57%) aged 18-64 (37.44±8.14) years. Among them, males accounted for 89.68% (365/407), those of Han ethnic group accounted for 89.93% (366/407), the unmarried accounted for 55.28% (225/407), and those with education level of junior high school or below accounted for 83.78% (341/407). The distribution of subtypes was predominated by CRF07_BC (47.18%, 192/407), followed by CRF01_AE (23.83%, 97/407), CRF08_BC (22.85%, 93/407), and other subtypes (6.14%, 25/407). The overall prevalence of drug resistance was 3.44% (14/407). The prevalence of drug resistance to protease inhibitors, nucleoside reverse transcriptase inhibitors and non-nucleoside reverse transcriptase inhibitors were 1.47%(6/407), 0.25% (1/407) and 1.72% (7/407) respectively. The mutation rate was 12.29% (50/407). No major drug resistance mutation was detected in protease and nucleoside reverse transcriptase regions. Higher rate of V179E mutation in the non-nucleoside reverse transcriptase region was detected in other subtypes and subtype CRF07_BC. Mutation seemed to have occurred in all 8 cases of subtype CRF55_01B in other subtypes. The highest mutation rate of E138A was detected in subtype CRF08_BC (3.23%). Two cases were resistant to all four drugs of NNRTIs. Conclusions: The prevalence of drug resistance in treatment-naive HIV-1 positive IDUs remained at a relatively low level during 2008-2015, in Guangzhou. Most infections were sensitive to existing antiviral drugs. However, drug resistance surveillance in IDUs infected with HIV should be strengthened to prevent the prevalence of multi-drug resistance and cross drug resistance.


Assuntos
Farmacorresistência Viral/genética , Usuários de Drogas , Infecções por HIV/tratamento farmacológico , HIV-1/genética , RNA Viral/genética , Adolescente , Adulto , Criança , Genes pol/genética , Genótipo , Infecções por HIV/diagnóstico , Infecções por HIV/etnologia , Infecções por HIV/psicologia , HIV-1/isolamento & purificação , Humanos , Masculino , Mutação , Prevalência , RNA Viral/efeitos dos fármacos , Adulto Jovem
9.
Eur J Neurol ; 25(2): 356-364, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29112784

RESUMO

BACKGROUND AND PURPOSE: Facial-sparing scapular myopathy (SHD) is the most common atypical form of facioscapulohumeral muscular dystrophy (FSHD), clinically defined as without apparent facial muscle weakness on neurological examination. The clinical profiles and genetic features of SHD are limited. METHODS: A cohort of 21 Chinese patients with SHD were confirmed by molecular genetic analysis based on pulsed-field gel electrophoresis. The clinical assessments and methylation analysis were noted. RESULTS: The patients had FSHD-related EcoRI fragments with 4qA haplotype ranging from 18 kb to 33 kb (mean 26.3 ± 4.6 kb). The mean onset age was 25.52 ± 8.3 years. Over half of the patients had scapular winging and asymmetry weakness consistent with FSHD, without facial symptoms during their visit. Their facial electromyogram results were almost normal or mild myogenic damage, as well as the myopathology and serum creatine kinase. A conflict was unexpectedly found in intergenerational DR1 methylation analysis. CONCLUSION: Facial-sparing scapular myopathy is characterized as mild myopathic symptoms and chronic progression of weakness. The diagnosis should be accurately confirmed through FSHD-sized fragment detection and 4qA/B variant determination. Although the next generations of SHD had more severe muscular symptoms, local hypomethylation within D4Z4 was not found as a modifier for clinical heterogeneity.


Assuntos
Cromossomos Humanos Par 4/genética , Distrofia Muscular Facioescapuloumeral , Adulto , Estudos de Coortes , Metilação de DNA , Feminino , Haplótipos , Humanos , Masculino , Pessoa de Meia-Idade , Distrofia Muscular Facioescapuloumeral/genética , Distrofia Muscular Facioescapuloumeral/metabolismo , Distrofia Muscular Facioescapuloumeral/patologia , Distrofia Muscular Facioescapuloumeral/fisiopatologia , Adulto Jovem
10.
Zhonghua Liu Xing Bing Xue Za Zhi ; 38(11): 1541-1545, 2017 Nov 10.
Artigo em Chinês | MEDLINE | ID: mdl-29141346

RESUMO

Objective: To investigated the etiologic characteristics of Shigella (S.) sonnei strains causing outbreaks and sporadic cases in some areas of Guangdong province and Guangxi Zhuang Autonomous Region during 2014-2016. Methods: Fourteen S. sonnei strains isolated from outbreaks and 6 S. sonnei strains from sporadic cases from Guangdong and Liuzhou of Guangxi Zhuang Autonomous Region were tested for antimicrobial resistance and analyzed by pulsed-field gel electrophoresis (PFGE). Six typical strains were selected for whole genome sequencing typing and compared with 51 strains isolated both at home and abroad from NCBI genome database. Results: The antibiotic resistance test indicated the isolates had high resistance rate to ampicillin, tetracycline, gentamicin, trimethoprim/sulfamethoxazole and nalidixic acid, while sensitive to azithromycin, chloromycetin and imipenem. PFGE showed high similarity (93.2%) among the strains isolated from different areas. The whole genome sequencing analysis also revealed that all the typical strains were clustered into a same evolution branch, close to some strains from Korea. Conclusions: The S. sonnei strains isolated from some areas of Guangdong and Guangxi Zhuang Autonomous Region showed high resistance to commonly used antibiotics, but they were sensitive to azithromycin, chloramphenicol and imipenem. The isolates in this study also showed similar PFGE patterns and close phylogenic evolution.


Assuntos
Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Farmacorresistência Bacteriana , Disenteria Bacilar/microbiologia , Shigella sonnei/efeitos dos fármacos , Shigella sonnei/isolamento & purificação , China , Surtos de Doenças , Eletroforese em Gel de Campo Pulsado , Humanos , Testes de Sensibilidade Microbiana , Análise de Sequência de DNA , Shigella sonnei/classificação , Shigella sonnei/genética , Tetraciclina/farmacologia
11.
Rev Sci Instrum ; 87(11): 11D434, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27910562

RESUMO

The foil resistive bolometer diagnostic on experimental advanced superconducting tokamak has been upgraded partly with a new generation of detectors. The new detectors have faster response time. However, the microwave interference is still a serious issue for the bolometer system. The system response to microwave is tested, and the test results show that the closed Wheatstone bridge circuit in the detector is the most sensitive component to high power microwave field. Simulation results of microwave transmission by the high frequency structure simulator software and shielding design are also presented.

12.
Opt Express ; 22(2): 1359-65, 2014 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-24515142

RESUMO

In this work, we investigate the plasmon-induced optical and magneto-optical anisotropies in the large-area square-ordered Co antidots film. It shows that both the outline of reflectivity spectrum and Kerr spectrum are significantly modified by surface plasmon polarition (SPP) resonances. Moreover, the magnitude of Kerr angle reaches to about 10 minutes at the azimuthal angle 45°, which is over 3 times of that of pure Co film. These phenomena are attributed to the SPP resonances with different diffraction orders of reciprocal lattice vectors.

13.
J Am Chem Soc ; 133(23): 8786-9, 2011 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-21557606

RESUMO

The Pb- and Sb- dual nanostructured PbTe system exhibits anomalous electronic transport behavior wherein the carrier mobility first increases and then decreases with increase in temperature. By combining in situ transmission electron microscopy observations and theoretical calculations based on energy filtering of charge carriers, we propose a plausible mechanism of charge transport based on interphase potential that is mediated by interdiffusion between coexisting Pb and Sb precipitates. These findings promise new strategies to enhance thermoelectric figure of merit via dual and multinanostructuring of miscible precipitates.

14.
Biomacromolecules ; 11(7): 1810-7, 2010 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-20518556

RESUMO

Simultaneous interpenetrating polymer networks (sIPNs) from concurrent copper(I)-catalyzed azide-alkyne cycloaddition "click chemistry" and atom transfer radical polymerization (ATRP) are described. Semi-sIPN of poly(ethylene glycol)/poly(2-hydroxyethyl methacrylate) (semi-PEG/PHEMA-sIPN) was first prepared via simultaneous "click chemistry" and ATRP from a mixture of poly(ethylene glycol)-diazide (N3-PEG-N3, Mn=4000 g/mol), tetrakis(2-propynyloxymethyl)methane (TPOM), ethyl-2-bromobutyrate (EBB), CuBr, pentamethyldiethylenetriamine (PMDETA), and 2-hydroxyethyl methacrylate (HEMA) in dimethylformamide (DMF). Full sIPN of PEG/PHEMA (full-PEG/PHEMA-sIPN) was then prepared via simultaneous "click chemistry" and ATRP from a mixture of N3-PEG-N3 (Mn=4000 g/mol), TPOM, EBB, CuBr, PMDETA, HEMA, and poly(ethylene glycol) diacrylate) (PEGDA, Mn=575) in DMF. Both the semi- and full-sIPNs exhibit a fast gelation rate and high gel yield. The sIPNs also exhibit high swelling ratios and good mechanical and antifouling properties. The morphology and thermal behavior of the sIPNs were studied by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). These sIPNs could find applications as biomaterials for contact lenses, biomedical materials, artificial organs, and drug delivery systems.


Assuntos
Materiais Biocompatíveis/síntese química , Hidrogéis/química , Polímeros/química , Alcinos/química , Azidas/química , Catálise , Cobre , Polietilenoglicóis/química
15.
J Environ Radioact ; 101(5): 362-8, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20346552

RESUMO

Several natural and anthropogenic radionuclides ((210)Pb, (226)Ra and (137)Cs) in guano-phosphatic coral sediments and pure guano particles collected from Ganquan, Guangjin, Jinqing and Jinyin Islands of the Xisha archipelago, South China Sea, were analyzed. The Constant Initial Concentration (CIC) model and the Constant Rate of Supply (CRS) model were applied for age calculation. The average supply rate of (210)Pb was 126 Bq m(-2) a(-1), very close to the flux of northern hemisphere average (125 Bq m(-2) a(-1)). The activities of anthropogenic radionuclides in the sediments were very low, indicating that human nuclear tests did not notably impact this region. The main source of radionuclides in the sediments was from atmospheric precipitation, and the organic matter derived from plant and produced by nutrient-rich guano could further enhance them.


Assuntos
Sedimentos Geológicos/química , Água do Mar/química , Poluentes Radioativos da Água/análise , Ecologia
16.
ACS Appl Mater Interfaces ; 1(2): 239-43, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20353208

RESUMO

A simple method for preparing solvent-resistant nanofibers with a thermal-sensitive surface has been developed by the combined technology of reversible addition-fragmentation chain-transfer (RAFT) polymerization, atom transfer radical polymerization (ATRP), electrospinning, and "click chemistry". Initially, well-defined block copolymers of 4-vinylbenzyl chloride (VBC) and glycidyl methacrylate (GMA) (PVBC-b-PGMA) were prepared via RAFT polymerization. Electrospinning of PVBC-b-PGMA from a solution in tetrahydrofuran gave rise to fibers with diameters in the range of 0.4-1.5 microm. Exposure to a solution of sodium azide (NaN(3)) not only affords nanofibers with azido groups on the surface but also leads to a cross-linking structure in the nanofibers. One more step of "click chemistry" between the PVBC-b-PGMA nanofibers with azido groups on the surface (PVBC-b-PGMA(-N3)) and alkyne-terminated polymers of N-isopropylacrylamide (NIPAM) (PNIPAM(AT)), which were prepared by ATRP, allows the preparation of a PVBC-b-PGMA nanofiber with thermal-sensitive PNIPAM brushes on the surface (PVBC-b-PGMA-g-PNIPAM). PVBC-b-PGMA-g-PNIPAM nanofibers exhibit a good resistance to solvents and thermal-responsive character to the environment, having a hydrophobic surface at 45 degrees C (water contact angle approximately 140 degrees) and having a hydrophilic surface at 20 degrees C (water contact angle approximately 30 degrees).

17.
J Clin Neurosci ; 13(5): 547-9, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16678425

RESUMO

The objective of this study was to prospectively evaluate sensory nerve conduction studies (NCS) in the distal lower limbs in the electrodiagnosis of peripheral neuropathy. We prospectively studied 316 consecutive patients with surface stimulation and recording, in comparison with 90 control subjects. A total of 310 patients were found to have lower limb sensory NCS abnormalities. In these patients, the rate of detection of peripheral neuropathy with superficial peroneal NCS (88.5%) was significantly higher (P<0.001) compared with sural NCS (75%). The superficial peroneal NCS appeared to have a higher detection rate for peripheral neuropathy in our study, and its study can be adjunctive to sural NCS.


Assuntos
Eletrodiagnóstico/normas , Condução Nervosa/fisiologia , Doenças do Sistema Nervoso Periférico/fisiopatologia , Nervo Fibular/fisiologia , Nervo Sural/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doenças do Sistema Nervoso Periférico/diagnóstico , Estudos Prospectivos
18.
Muscle Nerve ; 31(5): 633-6, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15645413

RESUMO

Short-segment nerve conduction studies were performed in 17 limbs with clinical features suggestive of ulnar neuropathy at the elbow. Recording from flexor carpi ulnaris yielded 93% sensitivity, compared with 71.4% when recording from abductor digiti minimi. The rationale underlying the technique is discussed. This approach should be of value as a diagnostic adjunct in technically challenging cases of ulnar neuropathy at the elbow.


Assuntos
Síndrome do Túnel Ulnar/diagnóstico , Síndrome do Túnel Ulnar/fisiopatologia , Cotovelo/fisiopatologia , Eletrodiagnóstico/métodos , Condução Nervosa/fisiologia , Nervo Ulnar/fisiopatologia , Potenciais de Ação/fisiologia , Estimulação Elétrica , Eletromiografia , Feminino , Mãos/inervação , Mãos/fisiopatologia , Humanos , Masculino , Músculo Esquelético/inervação , Músculo Esquelético/fisiopatologia , Valor Preditivo dos Testes , Estudos Prospectivos , Tempo de Reação/fisiologia , Nervo Ulnar/patologia
19.
J Neurol Sci ; 223(2): 199-202, 2004 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-15337623

RESUMO

Radial neuropathy most commonly occurs as a result of external compression at the spiral groove region. The posterior antebrachial cutaneous nerve (PACN) conduction study was performed in 15 consecutive patients with radial palsy. Unilateral PACN abnormalities were present in 11 patients. A normal PACN study was correlated with clinical improvement at 3 months. Conversely, PACN abnormality was correlated with radial motor axon loss and a poorer prognosis. The PACN study is a simple adjunct which provides additional information relating to the diagnosis and prognosis of radial lesions.


Assuntos
Condução Nervosa/fisiologia , Nervo Radial/fisiopatologia , Neuropatia Radial/fisiopatologia , Adolescente , Adulto , Eletromiografia , Eletrofisiologia/métodos , Feminino , Lateralidade Funcional/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Condução Nervosa/efeitos da radiação , Nervo Radial/efeitos da radiação
20.
Endocr Relat Cancer ; 11(2): 295-303, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15163304

RESUMO

Insulinoma is a clinically common cause of organic hypoglycemia. The prominent characteristic of insulinoma is endogenous hyperinsulinism. Until now, the molecular biology of human insulinoma has been little understood. In this study, gene expression profiling of human insulinoma was established by expressed sequence tag (EST) sequencing and cDNA array. A total of 2063 clones were obtained, of these, 1589 clones were derived from EST sequencing, 975 clones were derived from cDNA array and 501 clones were shared by the two methods. G protein alpha-stimulating activity polypeptide (Gsalpha) and carboxypeptidase E (CPE) were the most highly expressed genes in human insulinoma, as derived by EST sequencing and cDNA array respectively. The genes involved in the protein/insulin secretion pathway were strongly expressed in human insulinoma tissue. Meanwhile, eight full-length cDNAs of novel genes were cloned and sequenced. The results demonstrated the molecular biology of human insulinoma tissue at the level of transcript abundance and validated the efficacy of EST sequencing combined with cDNA array in the construction of gene expression profiling. In conclusion, the predominance of the genes participating in the secretory pathway suggested that regulation of secretion might be a major mechanism by which insulin release is abnormally increased in patients with insulinomas. It was also concluded that overexpression of the Gsalpha gene played an important role in the pathogenesis of insulinoma.


Assuntos
Perfilação da Expressão Gênica , Insulina/metabolismo , Insulinoma/genética , Neoplasias Pancreáticas/genética , Clonagem Molecular , Regulação Neoplásica da Expressão Gênica , Humanos , Secreção de Insulina , Insulinoma/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Neoplasias Pancreáticas/metabolismo
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