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1.
Opt Lett ; 48(12): 3255-3258, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37319075

RESUMO

Broadband supercontinuum (SC) light sources generated through nonlinear effects in solid-core photonic crystal fibers (PCFs) have been widely used in spectroscopy, metrology, and microscopy, leading to great application successes. The short-wavelength extension of such SC sources, a longstanding challenge, has been the subject of intensive study over the past two decades. However, the exact mechanism of blue and ultraviolet light generation, especially for some resonance spectral peaks in the short-wavelength regime, is not yet fully understood. Here, we demonstrate that the effect of inter-modal dispersive-wave radiation, which results from phase matching between pump pulses at the fundamental optical mode and packets of linear waves at some higher-order modes (HOMs) propagating in the PCF core, might be one of the critical mechanisms that can result in some resonance spectral components with wavelengths much shorter than that of the pump light. We observed in an experiment that several spectral peaks resided in the blue and ultraviolet regimes of the SC spectrum, whose central wavelengths can be tuned by varying the PCF-core diameter. These experimental results can be interpreted well using the inter-modal phase-matching theory, providing some useful insights into the SC generation process.


Assuntos
Tecnologia de Fibra Óptica , Raios Ultravioleta , Fótons , Microscopia
2.
Zhonghua Bing Li Xue Za Zhi ; 49(12): 1294-1299, 2020 Dec 08.
Artigo em Chinês | MEDLINE | ID: mdl-33287516

RESUMO

Objective: To investigate the expressions of HIF-1α, BRD4, Beclin1, LC3B and p62 in breast cancer tissues and their clinicopathological significance, and to study alterations of their expression in breast cancer cells under hypoxic microenvironment. Methods: Immunohistochemistry was used to detect HIF-1α, BRD4, Beclin1, LC3B and p62 protein expressions in 125 breast cancer tissues and 50 para-cancer normal breast tissues, and their correlation with clinicopathologic characteristics were analyzed. The expression of these proteins were also measured after 24 hours of hypoxia stimulation was detected in different breast cancer cell lines and normal breast epithelial cells. Results: The expression of HIF-1α, BRD4, Beclin1 and LC3B proteins in breast cancer tissues were significantly higher than in para-cancer normal breast tissues (P<0.05). There was a positive association between histologic grade, the expression of HIF-1α, BRD4, Beclin1 and LC3B (P<0.05). High expressions of HIF-1a and Beclin1 were often correlated with lymph node metastasis and lymphatic invasion (P<0.05). Increased HIF-1α, BRD4, Beclin1 and LC3B expression was associated with ER or PR negativity, but only HIF-1α was associated with HER2 positivity (P<0.05). HIF-1α, BRD4, Beclin1, and LC3B were positively correlated with each other in breast cancer tissues (P<0.01). After 24 hours of hypoxic stimulation, the expression of HIF-1α, BRD4, Beclin1 and LC3B was up-regulated in breast cancer cells. Conclusions: Hypoxia induces autophagy in breast cancer tissues. HIF-1α is positively correlated with BRD4, suggesting that BRD4 is involved in the regulation of autophagy by hypoxic microenvironment in breast cancer. High expression of HIF-1α, BRD4 and autophagy may play an important role in the development of breast cancer.


Assuntos
Neoplasias da Mama , Subunidade alfa do Fator 1 Induzível por Hipóxia , Proteínas Nucleares , Autofagia , Proteína Beclina-1 , Proteínas de Ciclo Celular , Humanos , Hipóxia , Subunidade alfa do Fator 1 Induzível por Hipóxia/fisiologia , Fatores de Transcrição , Microambiente Tumoral
3.
Zhonghua Yu Fang Yi Xue Za Zhi ; 52(6): 615-621, 2018 Jun 06.
Artigo em Chinês | MEDLINE | ID: mdl-29886683

RESUMO

Objective: To investigate the relationship between physical activity (PA) and the risk of incident hypertension among population in rural areas of China. Methods: The Community Intervention of Metabolic Syndrome in China & Chinese Family Health Study (CIMIC) was conducted in 2007-2008. Data on PA, smoking, drinking, blood pressure and other variables were obtained at baseline. Then the follow-up study of incident hypertension was performed during 2012-2015. A total of 41 457 participants aged ≥18 years and free from hypertension at baseline were included in the final analyses. PA was calculated as metabolic equivalent (MET) for each participant. Cox proportional hazard models were used to explore the relationship of PA with incident hypertension according to the quartiles of PA. Results: A total of 6 780 participants developed hypertension during an average follow up of 5.8 years. The annual incidence of hypertension was 2.80%. Compared to participants in the first quartile of PA, HR (95%CI) of incident hypertension decreased with the level of PA of 0.92 (0.86, 0.99), 0.72 (0.67, 0.77) and 0.70 (0.65, 0.75) for the 2(nd), 3(rd) and 4(th) quartile, respectively (P(trend)<0.001). In subgroup analyses, compared to the first quartile, hazards of hypertension among normotensive participants (systolic blood pressure less than 120 mmHg (1 mmHg=0.133 kPa) and diastolic blood pressure less than 80 mm Hg) in the 2(nd), 3(rd) and 4(th) quartile were 0.82 (0.70, 0.95), 0.73 (0.63, 0.85) and 0.78 (0.67, 0.90), respectively (P(trend)=0.002). Among participants with prehypertension (systolic blood pressure from 120 to 139 mmHg and/or diastolic blood pressure from 80 to 89 mmHg), similar trend for the relationship of PA and incident hypertension was also found with HR (95%CI) of 0.94 (0.87, 1.01), 0.71 (0.65, 0.77) and 0.66 (0.61, 0.71) for the 2(nd), 3(rd) and 4(th) quartile, respectively (P(trend)<0.001). Conclusion: There was linear trend association between PA and incident hypertension. Increased PA in daily life may be a protective factor against hypertension.


Assuntos
Exercício Físico , Hipertensão/epidemiologia , População Rural/estatística & dados numéricos , Adolescente , Adulto , China/epidemiologia , Seguimentos , Humanos , Incidência , Risco
4.
BJOG ; 124 Suppl 3: 59-63, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28856852

RESUMO

OBJECTIVE: To evaluate the safety and efficacy of ultrasound-guided high-intensity focused ultrasound (USgHIFU) for treating abdominal wall endometrioses (AWE). DESIGN: A retrospective study. SETTING: Department of Obstetrics and Gynaecology in China. POPULATION: Patients with abdominal wall endometriosis. METHODS: From August 2010 to April 2014, 32 patients with AWE were treated with USgHIFU in our hospital. USgHIFU treatment was performed with the Model JC-200 High Intensity Focused Ultrasound Tumor Therapeutic System. The symptom relief and the adverse effects were evaluated after USgHIFU ablation. MAIN OUTCOME MEASURES: USgHIFU as a new treatment option for patients with AWE. RESULTS: Contrast-enhanced ultrasound showed that all lesions were successfully ablated with USgHIFU. The follow-up results showed that the average volume of AWE lesions at 6 months after USgHIFU was significantly smaller than that before treatment (2.80 ± 0.12 versus 1.33 ± 0.31 cm3 ). The pain scores at 6 months after treatment were significantly lower than those before treatment (6.80 ± 2.64 versus 1.80 ± 0.3). The non-perfused volume (indicative of successful ablation) was measured in all patients immediately after treatment, ranging from 0.9 to 2.1 cm3 (median: 1.6 cm3 ), and the fractional ablation ranged from 87% to 100% (median: 94%). Local oedema was observed in these patients, lasting for 1-3 days only. No severe complications occurred during the follow-up period. CONCLUSIONS: Based on our study, USgHIFU ablation is a safe and effective method for treating AWE. TWEETABLE ABSTRACT: As a non-invasive treatment technique, HIFU could be used to treat abdominal wall endometriosis.


Assuntos
Parede Abdominal/cirurgia , Endometriose/cirurgia , Ablação por Ultrassom Focalizado de Alta Intensidade/métodos , Doenças Musculares/cirurgia , Adulto , Feminino , Ablação por Ultrassom Focalizado de Alta Intensidade/efeitos adversos , Humanos , Duração da Cirurgia , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos , Resultado do Tratamento
5.
Zhonghua Yu Fang Yi Xue Za Zhi ; 51(4): 332-335, 2017 Apr 06.
Artigo em Chinês | MEDLINE | ID: mdl-28395467

RESUMO

Objective: To analyze liquid milk exposure of thiocyanate among Chinese population and preliminarily assess its health risk. Methods: A total of 2 059 raw milk samples were collected during 2013 and 2014 from 12 Chinese provinces, New Zealand and Netherlands. Farms were chosed according to the main sources of dairy companies, the distribution of farms and the yield of milk. Content of thiocyanate were detected by ion chromatography. Liquid milk consumption data were taken from Chinese beverage and alcoholic beverage consumption survey in 18 cities or counties in 9 provinces, including 16 775 subjects older than 3. A simple distribution model was used to estimate the exposure of thiocyanate from liquid milk. The tolerable daily intake (TDI) of thiocyanate was made 0.08 mg·kg(-1)·d(-1). Then the exposures of different age groups were compared with TDI. Results: Finally, 1 331 samples out of 2 059 were detected to contain thiocyanate. The detection rate was 65%. The average concentration of thiocyanate was 2.11 mg/kg, with a range of 0.10-16.20 mg/kg. The general population's consumption of thiocyanate by drinking liquid milk was 0.001 mg · kg(-1) · d(-1), which was lower than TDI. The P(95) of general population and consumers were 0.009 mg · kg(-1) · d(-1) and 0.020 mg·kg( -1)·d(-1) respectively, which were also lower than TDI. Mean exposures of population aged 3-6, 7-12, 13-17, 18-59 as well as elderly aged 60 and above were 0.007, 0.003, 0.002, 0.001 and 0.001 mg · kg(-1)·d(-1) respectively, which were all lower than TDI. Conclusion: The results suggested that the health risk of thiocyanate exposure by drinking liquid milk among Chinese population was at a low level. However, milk products for children deserve more concern.


Assuntos
Inocuidade dos Alimentos/métodos , Leite/química , Tiocianatos/química , Idoso , Animais , Povo Asiático , Criança , Humanos , Países Baixos , Nova Zelândia , Medição de Risco
6.
Fa Yi Xue Za Zhi ; 33(4): 368-373, 2017 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-29219266

RESUMO

OBJECTIVES: To analyze and detect the whole genome sequence of human mitochondrial DNA (mtDNA) by Ion Torrent PGM™ platform and to study the differences of mtDNA sequence in different tissues. METHODS: Samples were collected from 6 unrelated individuals by forensic postmortem examination, including chest blood, hair, costicartilage, nail, skeletal muscle and oral epithelium. Amplification of whole genome sequence of mtDNA was performed by 4 pairs of primer. Libraries were constructed with Ion Shear™ Plus Reagents kit and Ion Plus Fragment Library kit. Whole genome sequencing of mtDNA was performed using Ion Torrent PGM™ platform. Sanger sequencing was used to determine the heteroplasmy positions and the mutation positions on HVⅠ region. RESULTS: The whole genome sequence of mtDNA from all samples were amplified successfully. Six unrelated individuals belonged to 6 different haplotypes. Different tissues in one individual had heteroplasmy difference. The heteroplasmy positions and the mutation positions on HVⅠ region were verified by Sanger sequencing. After a consistency check by the Kappa method, it was found that the results of mtDNA sequence had a high consistency in different tissues. CONCLUSIONS: The testing method used in present study for sequencing the whole genome sequence of human mtDNA can detect the heteroplasmy difference in different tissues, which have good consistency. The results provide guidance for the further applications of mtDNA in forensic science.


Assuntos
DNA Mitocondrial/genética , Ciências Forenses/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Mitocôndrias/genética , Análise de Sequência de DNA/métodos , Sequenciamento Completo do Genoma , Povo Asiático/genética , Autopsia , Sequência de Bases , DNA Mitocondrial/análise , Patologia Legal , Ciências Forenses/instrumentação , Genoma Humano , Genoma Mitocondrial , Haplótipos , Humanos , Mitocôndrias/química
7.
Zhonghua Yi Xue Za Zhi ; 96(6): 438-41, 2016 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-26875919

RESUMO

OBJECTIVE: To investigate whether Sirolimus could affect the glycolytic catabolism pathways of pancreatic carcinoma through the control of hypoxia induced factor (HIF-1α) to inhibit the growth of tumor, and explore the potential mechanism of targeting the signaling pathways of mTOR for the treatment of pancreatic carcinoma. METHODS: Sirolimus was applied to treat the pancreatic carcinoma in nude mice orthotopic transplantation model, its difference with the control group was compared; RT-PCR and Western blot were used to measure the mRNA and protein expression of mTOR, HIF-1α, Glucose carrier protein 1 (GLUT-1) and Hexokinase Ⅱ (HK-Ⅱ), respectively; the changes of activity of HK-Ⅱ in the tumor was determined. RESULTS: The tumor mass of the control group (1.97±0.21)g was significantly larger than that of the Sirolimus group (0.38±0.10)g (P<0.01), and the volume of the control group (1.40±0.15) mm(3) was significantly larger than that of the Sirolimus group (0.27±0.07) mm(3) (P<0.01). The expressions of mTOR, GLUT-1 and HK-Ⅱ mRNA in the control group were higher than those of the Sirolimus group (P<0.05), while no significant change was observed in the expression of HIF-1α (P>0.05); the expressions of p-mTOR, HIF-1α, GLUT-1 and HK-Ⅱ proteins in the control group were higher than those of the Sirolimus group (P<0.05). The activity of HK-Ⅱ in the control group was higher than that of the Sirolimus group (P<0.05). CONCLUSION: Sirolimus could affect the expression of GLUT-1 and HK-Ⅱ in pancreatic carcinoma through the effects of HIF-1α to inhibit tumor growth, indicating that blocking the mTOR pathway could control the glycolytic metabolism pathways of pancreatic carcinoma, which may become the new strategy for the treatment of pancreatic carcinoma.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Proteínas Facilitadoras de Transporte de Glucose/efeitos dos fármacos , Hexoquinase , Subunidade alfa do Fator 1 Induzível por Hipóxia/efeitos dos fármacos , Neoplasias Pancreáticas/tratamento farmacológico , Sirolimo/farmacologia , Animais , Transportador de Glucose Tipo 1/metabolismo , Humanos , Camundongos , Camundongos Nus , RNA Mensageiro , Transdução de Sinais , Serina-Treonina Quinases TOR , Neoplasias Pancreáticas
9.
Fa Yi Xue Za Zhi ; 32(4): 254-256, 2016 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-29188665

RESUMO

OBJECTIVES: To investigate the specific microbial signatures in vaginal fluid. METHODS: Vaginal fluid (16 samples), saliva (16 samples), feces (16 samples), semen (8 samples), peripheral blood (8 samples), urine (5 samples), and nasal secretion (4 samples) were collected respectively. The 16S rRNA genes of Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus jensenii, Lactobacillus iners, and Atopobium vaginae were amplified. PCR production was detected via a 3130xl Genetic Analyzer. RESULTS: The detected number of Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus jensenii, Lactobacillus iners, and Atopobium vaginae were 15, 5, 8, 14, and 3 in all vaginal fluid samples, respectively. Lactobacillus crispatus and Lactobacillus jensenii existed specifically in vaginal fluid. CONCLUSIONS: There is a potential application value to detect Lactobacillus crispatus and Lactobacillus jensenii for the identification of vaginal fluid.


Assuntos
Líquidos Corporais/microbiologia , Vagina/microbiologia , Actinobacteria/classificação , Sangue/microbiologia , Fezes/microbiologia , Feminino , Genes Bacterianos , Humanos , Lactobacillus/classificação , Cavidade Nasal/microbiologia , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética , Saliva/microbiologia , Sêmen/microbiologia
10.
Fa Yi Xue Za Zhi ; 32(5): 371-377, 2016 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-29205009

RESUMO

There are two kinds of amelogenin gene mutation, including mutation in primer-binding region of amelogenin gene and micro deletion of Y chromosome encompassing amelogenin gene, and the latter is more common. The mechanisms of mutation in primer-binding region of amelogenin gene is nucleotide point mutation and the mechanism of micro deletion of Y chromosome encompassing amelogenin gene maybe non-allelic homologous recombination or non-homologous end-joining. Among the population worldwide, there is a notably higher frequency of amelogenin gene mutations in Indian population, Sri Lanka population and Nepalese population which reside within the Indian subcontinent. Though amelogenin gene mutations have little impact on fertility and phenotype, they might cause incorrect result in gender identification. Using composite-amplification kit which including autosomal STR locus, amelogenin gene locus and multiple Y-STR locus, could avoid wrong gender identification caused by amelogenin gene mutation.


Assuntos
Amelogenina/genética , Aberrações Cromossômicas , Cromossomos Humanos Y/genética , Alelos , Povo Asiático/genética , Humanos , Índia , Masculino , Repetições de Microssatélites , Nepal , Reação em Cadeia da Polimerase , Deleção de Sequência , Sri Lanka
11.
Anim Genet ; 45(3): 449-52, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24628343

RESUMO

Y-chromosome-specific haplotypes (Y-haplotypes) constructed using single nucleotide polymorphisms (Y-SNPs) in the MSY (male-specific region of the Y-chromosome) are valuable in population genetic studies. But sequence variants in the yak MSY region have been poorly characterized so far. In this study, we screened a total of 16 Y-chromosome-specific gene segments from the ZFY, SRY, UTY, USP9Y, AMELY and OFD1Y genes to identify Y-SNPs in domestic yaks. Six novel Y-SNPs distributed in the USP9Y (g.223C>T), UTY19 (g.158A>C and g.169C>T), AMELY2 (g.261C>T), OFD1Y9 (g.165A>G) and SRY4 (g.104G>A) loci, which can define three Y-haplotypes (YH1, YH2 and YH3) in yaks, were discovered. YH1 was the dominant and presumably most ancient haplotype based on the comparison of UTY19 locus with other bovid species. Interestingly, we found informative UTY19 markers (g.158A>C and g.169C>T) that can effectively distinguish the three yak Y-haplotypes. The nucleotide diversity was 1.7 × 10(-4) ± 0.3 × 10(-4) , indicating rich Y-chromosome diversity in yaks. We identified two highly divergent lineages (YH1 and YH2 vs. YH3) that share similar frequencies (YH1 + YH2: 0.82-0.89, YH3: 0.11-0.18) among all three populations. In agreement with previous mtDNA studies, we supported the hypothesis that the two highly divergent lineages (YH1 and YH2 vs. YH3) derived from a single gene pool, which can be explained by the reunion of at least two paternal populations with the divergent lineages already accumulated before domestication. We estimated a divergence time of 408 110 years between the two divergent lineages, which is consistent with the data from mitochondrial DNA in yaks.


Assuntos
Bovinos/genética , Polimorfismo de Nucleotídeo Único , Cromossomo Y/genética , Animais , Sequência de Bases , China , Haplótipos , Masculino , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase/veterinária , Alinhamento de Sequência/veterinária
12.
Proc Natl Acad Sci U S A ; 108(37): 15058-63, 2011 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-21876133

RESUMO

In order to survive, self-serving agents in various kinds of complex adaptive systems (CASs) must compete against others for sharing limited resources with biased or unbiased distribution by conducting strategic behaviors. This competition can globally result in the balance of resource allocation. As a result, most of the agents and species can survive well. However, it is a common belief that the formation of a herd in a CAS will cause excess volatility, which can ruin the balance of resource allocation in the CAS. Here this belief is challenged with the results obtained from a modeled resource-allocation system. Based on this system, we designed and conducted a series of computer-aided human experiments including herd behavior. We also performed agent-based simulations and theoretical analyses, in order to confirm the experimental observations and reveal the underlying mechanism. We report that, as long as the ratio of the two resources for allocation is biased enough, the formation of a typically sized herd can help the system to reach the balanced state. This resource ratio also serves as the critical point for a class of phase transition identified herein, which can be used to discover the role change of herd behavior, from a ruinous one to a helpful one. This work is also of value to some fields, ranging from management and social science, to ecology and evolution, and to physics.


Assuntos
Adaptação Fisiológica , Comportamento Social , Simulação por Computador , Humanos , Modelos Biológicos
13.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 59(4): 326-335, 2024 Apr 09.
Artigo em Chinês | MEDLINE | ID: mdl-38548589

RESUMO

Objective: To evaluate the effects of photodynamic therapy (PDT) in extraction sockets of periodontally compromised molars on soft tissue healing, postoperative pain, bone density and bone height changes. Methods: This study is a single-center, single-blind, randomized controlled superiority clinical trial. Thirty-eight periodontally compromised molars requiring extraction in patients attending the Department of Periodontology, Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, from December 2022 to September 2023 were included, and randomly assigned to PDT group and control group. The control group received routine debridement after extraction, while PDT group received routine debridement followed by PDT. The bucco-lingual and mesio-distal wound distances at 7 and 14 d after extraction were measured, and then the wound closure rates were calculated. Evaluating the soft tissue healing indexes at 7 and 14 d after extraction. The visual analogue scale was used to assess the pain level at 6 h, 1 d, 2 d, and 3 d after tooth extraction. Apical radiographs were taken immediately and 2 months after extraction in order to compare the changes of the bone density and height. Results: The wound closure rate at 1 week was (78.08±5.45)% in PDT group and (71.03±6.82)% in control group, with significant differences (P<0.01). The wound closure rate at 2 weeks in PDT group [(85.88±3.84) %] was significantly higher than that in the control group [(81.66±3.79) %] (P<0.01), but did not reach the superiority value of the superiority test (superiority value=10%, 95%CI at 1 week: 3.00%-11.12%, 95%CI at 2 weeks: 1.71%-6.73%). The soft tissue healing index of PDT group at 1 week was significantly better than the control group (P<0.05), but there was no significant difference between the two groups at 2 weeks (P>0.05). There was no significant difference between the two groups in terms of postoperative pain at 6 h, 1 d, 2 d and 3 d as well as in bone density and height changes at 2 months after tooth extraction (P>0.05). Conclusions: PDT could promote soft tissues healing to some extent, but did not provide additional assistance in the healing of extraction sockets of periodontally compromised teeth. PDT did not show benefits on postoperative pain, changes of the bone density and bone height after tooth extraction.


Assuntos
Fotoquimioterapia , Cicatrização , Humanos , Método Simples-Cego , Extração Dentária , Dor Pós-Operatória/tratamento farmacológico , Alvéolo Dental/cirurgia
14.
Anim Genet ; 44(4): 446-9, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23347145

RESUMO

To determine the genetic diversity and paternal origin of Chinese cattle, 302 males from 16 Chinese native cattle breeds as well as 30 Holstein males and four Burma males as controls were analysed using four Y-SNPs and two Y-STRs. In Chinese bulls, the taurine Y1 and Y2 haplogroups and indicine Y3 haplogroup were detected in seven, 172 and 123 individuals respectively, and these frequencies varied among the Chinese cattle breeds examined. Y2 dominates in northern China (91.4%), and Y3 dominates in southern China (90.8%). Central China is an admixture zone, although Y2 predominates overall (72.0%). The geographical distributions of the Y2 and Y3 haplogroup frequencies revealed a pattern of male indicine introgression from south to north China. The three Y haplogroups were further classified into one Y1 haplotype, five Y2 haplotypes and one Y3 haplotype in Chinese native bulls. Due to the interplay between taurine and indicine types, Chinese cattle represent an extensive reservoir of genetic diversity. The Y haplotype distribution of Chinese cattle exhibited a clear geographical structure, which is consistent with mtDNA, historical and geographical information.


Assuntos
Bovinos/genética , Variação Genética , Repetições de Microssatélites/genética , Cromossomo Y/genética , Animais , Cruzamento , China , DNA Mitocondrial/química , DNA Mitocondrial/genética , Pai , Frequência do Gene , Geografia , Haplótipos , Masculino , Filogenia , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA/veterinária
15.
Water Sci Technol ; 65(6): 1041-7, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22378000

RESUMO

Polyvinylidene fluoride (PVDF)/polymethylmethacrylate (PMMA)/thermoplastic polyurethane (TPU) blend hollow fiber membranes were successfully prepared by the wet-spinning method with the loading of PMMA and TPU in a range of polymer concentrations varying from 0 to 20 wt% and at a total polymer concentration of 16 wt%. The influence of the addition of PMMA and TPU on the morphologies and the properties of such prepared membranes was investigated through FTIR-ATR, SEM, viscosity measurements, UF experiments and mechanical strength tests. Based on the experimental results, the compatibility of the PVDF, PMMA and TPU blend was best under the conditions of the PVDF-rich phase. The elongation at break of the membrane increased to a maximum of 146% with increase in the TPU concentration to 20 wt% in dope solution. The addition of PMMA increased the water permeation flux from 120 to 195 L/(m(2) h) initially. The flux then decreased when PMMA concentration was increased to over 10 wt%. The membranes obtained at optimized blending ratio were applied to the dyeing process wastewater filtration. During continuous filtration for 8 h, the flux was stabilized at about 20 L/(m(2) h) at 0.1 MPa. The reduction in COD(Cr), turbidity and color were about 63, 84 and 63% respectively.


Assuntos
Membranas Artificiais , Polimetil Metacrilato/química , Poliuretanos/química , Polivinil/química , Eliminação de Resíduos Líquidos/instrumentação , Eliminação de Resíduos Líquidos/métodos , Purificação da Água/instrumentação
16.
Phys Rev Lett ; 104(3): 034501, 2010 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-20366645

RESUMO

We numerically demonstrate optical negative refraction in ferrofluids containing isotropic Fe3O4 nanoparticles, each having an isotropic Ag shell, in the presence of an external dc magnetic field H. The all-angle broadband optical negative refraction with magnetocontrollability arises from H-induced chains or columns. They result in hyperbolic equifrequency contour for transverse magnetic waves propagating in the system. The finite element simulations verify the analyses using the effective medium approximation. Experimental demonstration and potential applications are suggested and discussed.

17.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 55(2): 129-134, 2020 Feb 09.
Artigo em Chinês | MEDLINE | ID: mdl-32074677

RESUMO

Research have indicated that inadequate keratinized tissue has a negative effect on patient oral hygiene, resulting in peri-implant inflammation. It has been recommended that an apically repositioned flap alone or in combination with autogenous soft tissue grafts can increase the width of keratinized mucosa around dental implants, which promotes long term peri-implant health. This review summarized research progress on augmentation techniques of keratinized tissue arround implants in recent years, so as to provide reference for clinical practice and research design in the future.


Assuntos
Implantes Dentários , Queratinas , Mucosa Bucal/transplante , Retalhos Cirúrgicos/transplante , Gengiva , Humanos , Higiene Bucal
18.
J Phys Chem B ; 113(16): 5412-7, 2009 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-19331326

RESUMO

In electric-field-responsive soft-matter systems, the suspended particles respond to the Lorentz local field (LLF), yielding abundant important phenomena. Even though the particles can easily rotate, the LLF was conventionally adopted as a quantity that is independent of rotations in the literature. In contrast, here we design an experiment to measure the LLF between two metallic spheres, one of which is rotating, and report a rotation-driven reduction. Excellent agreement between our experiment and theory reveals the role of the relaxation of dipole moments. Its relevance to biophysics, colloidal physics, and nonlinear physics is also discussed.


Assuntos
Campos Eletromagnéticos , Eletrodos , Modelos Químicos , Nióbio/química , Óxidos/química , Rotação , Óleos de Silicone/química
19.
J Phys Chem B ; 113(27): 9092-7, 2009 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-19530664

RESUMO

Many researches on polar-molecular electrorheological (PMER) fluids with giant electrorheological effects were reported in recent years. The particles of PMER fluids (PMER particles) are known to have a dielectric core with high dielectric constant and a shell of polar molecules. Our calculation of local electric fields using the finite element approach shows that the local electric field can cause an orientational polarization of the polar molecules. The saturation of the orientational polarization occurs on the outer shells of two nearby PMER particles. Then, it causes the strong outer shell-outer shell interaction between the two particles, and this kind of interaction is just responsible for the giant electrorheological effect. It is further realized that the PMER effect is mainly due to the interaction of the tail-head connected polar molecules within the two outer shells between the two PMER particles. Our theoretical results of static yield stresses are shown to be in excellent agreement with the reported experimental data by several groups. For general PMER fluids, the calculated static yield stress is nearly proportional to R(x-1). When h/R, the ratio between the thickness of shells and radius of PMER particles, changes from 0.05 to 0.5, the index x changes accordingly from 0.64 to 0.51. It is also found that particles with thinner thickness h and smaller radius R have larger electrorheological effects until the static yield stress shows a peak when R reaches about 10 nm.

20.
J Phys Chem B ; 112(26): 7865-74, 2008 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-18529026

RESUMO

Dynamic behaviors are abundant in field-responsive colloidal suspensions. Being beyond the usual point-dipole approximation, we develop a multiple image method of dipoles for two dynamic unequal colloidal dielectric spherical particles, which can be perfectly reduced to those for two static conducting particles. The method is applied to investigate colloidal electric interparticle forces under various conditions of dynamics. As a result, we find that the force can be enhanced, reduced, or even changed from attraction to repulsion, or vice versa. Some other interesting results are also reported. Our theoretical results are compared favorably with existing experimental observations. Therefore, it becomes possible to achieve desired colloidal structures by adjusting colloidal interactions by choosing appropriate dynamic phenomena.


Assuntos
Elétrons , Coloides/química
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