Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
1.
Sci Rep ; 13(1): 16273, 2023 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-37770517

RESUMO

Vortex matter in layered high-[Formula: see text] superconductors, including iron-pnictides, undergo several thermodynamic phase transitions due to the complex interplay of pinning energy, thermal energy and elastic energy. Moreover, the presence of anisotropy makes their vortex physics even more intriguing. Here, we report a detailed vortex dynamics study, using dc magnetization measurements, in a triclinic iron-pnictide superconductor (Ca[Formula: see text]La[Formula: see text])[Formula: see text](Pt[Formula: see text]As[Formula: see text])(Fe[Formula: see text]As[Formula: see text])[Formula: see text], with a superconducting transition temperature, T[Formula: see text] [Formula: see text] 31 K. A second magnetization peak (SMP) feature is observed for magnetic field perpendicular (H[Formula: see text]c) and parallel (H[Formula: see text]ab) to the crystal plane. However, its fundamental origin is quite different in both directions. For H[Formula: see text]c, the SMP can be well explained using an elastic-to-plastic vortex creep crossover, using collective creep theory. In addition, a possible rhombic-to-square vortex lattice phase transition is also observed for fields in between the onset-field and peak-field related to the SMP. On the other hand, for H[Formula: see text]ab, a clear signature of an order-disorder vortex phase transition is observed in the isothermal M(H) measurements at T [Formula: see text] 6 K. The disordered phase exhibits the characteristics of entangled pinned vortex-liquid. We construct a comprehensive vortex phase diagram by displaying characteristic temperatures and magnetic fields for both crystal geometries in this unique superconducting compound. Our study sheds light on the intricate vortex dynamics and pinning in an iron-pnictide superconductor with triclinic symmetry.

2.
Trop Biomed ; 37(2): 452-457, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33612814

RESUMO

Toxoplasma gondii is a world-widely spread zoonotic parasite. However, scarce knowledge is known about the prevalence of T. gondii infection in people in Hubei province, China. This study herein was to perform epidemiological investigation of T. gondii infection in people in this region. A total 12527 blood samples were obtained during 2015-2018, and were assayed for T. gondii antibodies of IgG and IgM, respectively by employing an indirect hemagglutination test (IHA). The results discovered that the prevalence of T. gondii in people was 2.44% and 6.1%, respectively based on antibodies of IgG and IgM, respectively. The prevalence was ranged from 0.3% to 5.4% during 2015-2018 based on IgM antibodies. For genders, the prevalence was 0.7% and 2.6% in males and females, respectively based on IgM antibodies. In different years, the prevalence was ranged from 4.9% to 14.0% based on IgG antibodies. The prevalence of T. gondii was 4.9% and 6.6% in males and femalesy based on IgG antibodies. The current results may be helpful for the implementation of preventive measures against Toxoplasma infection among people living in this region.


Assuntos
Toxoplasmose/epidemiologia , Anticorpos Antiprotozoários/sangue , China/epidemiologia , Feminino , Testes de Hemaglutinação , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Prevalência , Estudos Soroepidemiológicos , Toxoplasma
3.
Zhonghua Bing Li Xue Za Zhi ; 47(10): 753-757, 2018 Oct 08.
Artigo em Chinês | MEDLINE | ID: mdl-30317729

RESUMO

Objective: To analyze the clinical and pathological features of Cronkhite-Canada syndrome (CCS), and to investigate the significance of IgG4 positive plasma cell infiltration. Methods: Clinical presentations, endoscopic appearances and morphological features of 18 patients diagnosed with CCS at Peking Union Medical College Hospital during 2000-2016 were included in the study.There were 11 male and 7 female patients. IgG4 and IgG immunohistochemical stains were performed in total of 55 biopsies from the patients (36 polyps, 10 adenoma and 9 surrounding mucosa) and a control group of 58 cases (19 colonic mucosa, 7 colonic hyperplastic polyps, 9 inflammatory bowel disease and 23 adenoma). Results: Average age of CCS was 59 years (range 47-69 years) and the male to female ratio was 11∶7. All patients had at least one ectoderm lesion. Fourteen cases had testicular abnormalities. Digestive tract symptoms were encountered in most cases. Four patients had a history of connective tissue disease. Endoscopically, multiple polyps were found to involve entire gastrointestinal tract except the esophagus. Morphologically, CCS polyps were characterized by prominent mucosal edema, mild to moderate inflammation, glands hyperplasia and cystic dilatation. Ten cases had colonic adenoma and one case had rectal adenocarcinoma. While none of the cases reached the diagnostic criteria of IgG4 disease, the positive rate of IgG4 positive plasma cells in adenoma of CCS was significantly higher than that in polyps and surrounding mucosa of CCS (60.0%∶13.9%∶0, P<0.01). The positive rate of IgG4 positive plasma cells of adenoma and polyp of CCS had an increased tendency compared to that of adenoma and polyp of control group (60.0%∶34.8%; 13.9%∶0). Conclusion: The findings in the study do not support that CCS is a variant of IgG4 disease, although IgG4 positive plasma cells may be involved in the pathogenesis of CCS, which may be explored in future investigations.


Assuntos
Polipose Intestinal , Adenoma , Idoso , Biópsia , Neoplasias Colorretais , Feminino , Humanos , Imunoglobulina G , Mucosa Intestinal , Masculino , Pessoa de Meia-Idade , Plasmócitos
4.
Trop Biomed ; 35(3): 736-743, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33601760

RESUMO

To investigate the prevalence of Peste des petitis ruminants in yaks and cattle in poorly studied areas of China. A total of 1202 and 560 blood samples were collected from yaks and cattle, respectively and processed using a commercial ELISA kit. Multivariable logistic regression model was piloted to find the variables, potentially associated with exposure of PPR infection in yaks and cattle. Results indicated that the overall prevalence of PPR in yaks was 11.2%. A total 66 (11.8%) out of 560 were examined out to be positive to PPR in cattle in Jiangxi province. According to conditional stepwise logistic regression, region, age and gender were found to be the more influencing risk factors in yaks, while region and age were found to be the potential risk factors in cattle. The current results reported the prevalence and associated risk factors of PPR in bovine for the first time in China.

5.
Trop Biomed ; 34(3): 576-582, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33592926

RESUMO

Ascaris is a helminthic parasite, which infects a wide range of host species causing ascariasis, a predominant disease worldwide. This parasite causes significant economic losses to the pig industry. The current study was designed to determine the Ascaris nematode by the genetic characterization of three mitochondrial (mt) genes namely NADH dehydrogenase subunit 1 (nad1), cytochrome oxidase subunit 1 (cox1) and cytochrome oxidase subunit 2 (cox2). A high infection rate of Ascaris nematode has been found in Tibetan pigs at the slaughter houses in Tibet Autonomous Region of China. The nad1, cox1 and cox2 genes sequences collected from adult Ascaris individuals were amplified by polymerase chain reaction. The cloned-amplicons and the positive products were sequenced and phylogenetic analysis was performed. The results indicated that the Ascaris infecting the Tibetan pigs were Ascaris suum (A. suum). This is the first report on the isolation, identification and genetic characterization of three mitochondrial genomes (nad1, cox1, and cox2) of A. suum originated from Tibetan pigs at high altitudes in Tibet.

6.
Trop Biomed ; 34(4): 903-910, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33592960

RESUMO

The current study was performed to investigate the prevalence, associated risk factors exploration and phylogenetic analysis of Echinococcus granulosus (E. granulosus) genotypes isolated from Tibetan pigs. A total 373 Tibetan pigs were examined during 2014 and 2015, and the variables potentially associated with E. granulosus infection were explored with a multivariable logistic regression model. E. granulosus cysts (n=37) were collected from Tibetan pigs (lungs or livers). Fragments amplification of mitochondrial (mt) DNA of cox1 (shorter and longer) and atp6 were employed. The genotype of E. granulosus were identified by sequence and phylogenetic analysis. Results showed the prevalence of E. granulosus in Tibetan pigs was 9.9%. The prevalence of E. granulosus in male and female Tibetan pigs was 6.8% and 13.3%, with a significant difference in the two genders (P<0.05). In different seasons, the infection rate of E. granulosus in Tibetan pigs were ranged from 5.8% to 12.3%. E. granulosus infection rates in different growing stages of Tibetan pigs were ranged from 4.4% to 15.9%, with a statistical difference in the three stages (P<0.01). The prevalence of E. granulosus in Tibetan pigs were 7.9% in 2014 and 13.0% in 2015. Genders and growing stages were demonstrated to be risk factors to influence the prevalence significantly through multivariable logistic regression model. All the three fragments were successfully amplified from each of the 37 cysts. E. granulosus genotypes of G4 and G6 were identified by comparing with reference sequences of E. genotypes available at NCBI database and phylogenetic analysis by using MEGA software.

7.
Trop Biomed ; 34(1): 80-83, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33592984

RESUMO

Seroprevalence of Bluetongue virus (BTV) in goats from Hubei was investigated by a commercial competitive enzyme-linked immunosorbent assay kits. Blood samples (n= 1157) were collected during the year 2014 and 2015. The results showed that 13.31% (CI 95% 11.4%-15.4%) serum samples were positive for BTV antibodies in goats in Hubei. The prevalence of BTV antibodies in each region ranged from 1.32% to 27.70%, and differences among the regions were statistically significant (p < 0.01). The prevalence of BTV in male and female goats was 14.23% (95% CI: 11.3, 17.6) and 12.58% (95% CI: 10.1, 15.4), respectively, no significant difference in genders (p > 0.05). In different seasons, the seroprevalence were 8.94% (95% CI: 5.6, 13.3) in spring; 18.31% (95% CI: 14.5, 22.7) in summer; 23.08% (95% CI: 17.0, 30.2) in autumn and 6.98% (95% CI: 4.6, 10.0) in winter, respectively with a significant difference of the prevalence in the different seasons (p < 0.01).

8.
Artigo em Inglês | MEDLINE | ID: mdl-26947428

RESUMO

Neutrophil lymphocyte ratio (NLR) and platelet lymphocyte ratio (PLR) had been analysed in many kind of tumours, but its role of predict the oesophageal squamous cell carcinoma (ESCC) patients' prognosis was not reach a consensus. Relationship between NLR, PLR and ESCC located in the middle or lower segment was evaluated. 317 patients with ESCC who underwent attempted curative oesophagectomy were analysed in this study. 157 and 98 patients had elevated NLR and PLR respectively (NLR >3.3 and PLR >150). The median overall survival time (OS) and disease-free survival (DFS) was 34.1 and 19.2 months respectively. Multivariate analysis found PLR >150 (P = 0.018, HR 1.426, 95%CI 1.063-1.912) accompanied by male, lymphatic metastases, tumour size more than 3 cm, tumour located at middle segment and poor differentiation were associated with significantly worse DFS. Meanwhile, gender, lymphatic metastases, tumour location and differentiation along with PLR >150 (P = 0.003, HR 1.595, 95% CI 1.172-2.170) and NLR>3.3 (P = 0.039, HR 1.367, 95% CI 1.015-1.840) were all independent prognostic factors for OS. Preoperative NLR and PLR might be used as predictive factors in patients with ESCC. For DFS, elevated PLR compared to NLR may have an advantage to indicate poor prognosis.


Assuntos
Carcinoma de Células Escamosas/cirurgia , Neoplasias Esofágicas/cirurgia , Esofagectomia , Esôfago/cirurgia , Contagem de Linfócitos , Neutrófilos , Contagem de Plaquetas , Adulto , Idoso , Carcinoma de Células Escamosas/sangue , Carcinoma de Células Escamosas/patologia , Intervalo Livre de Doença , Neoplasias Esofágicas/sangue , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago , Esôfago/patologia , Feminino , Humanos , Contagem de Leucócitos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Prognóstico , Modelos de Riscos Proporcionais , Fatores Sexuais , Taxa de Sobrevida , Carga Tumoral
9.
Zhonghua Liu Xing Bing Xue Za Zhi ; 37(9): 1272-1276, 2016 Sep 10.
Artigo em Chinês | MEDLINE | ID: mdl-27655577

RESUMO

Objective: To investigate the prevalence of the loss of basic activities of daily living (ADL) and instrumental ADL (IADL) influencing factors in the elderly population in China and provide evidence for the effective keeping and improvement of the elderly daily living. Methods: The information about demographic characteristics and activities of daily living of elderly Chinese aged ≥60 years were collected by using the data of 2013 China Health and Retirement Longitudinal Study. The elderly's ADL of taking bath, eating, getting in and out of bed, dressing, toilet use, and defecating and the IADL of doing housework, cooking, making phone call, taking medicine, shopping and money managing were evaluated. The differences in loss of ADL among different populations were compared by χ2 test and logistic regression analysis was conducted to identify influencing factors for the loss of ADL and IADL. Results: The overall ADL loss rate was 23.8% and the overall IADL loss rate was 35.4% in elderly Chinese. The proportion of having trouble in toilet use was highest among all ADL items, followed by bathing and getting in and out of bed. The proportion of having trouble in making phone call was highest among all IADL items, followed by doing housework and money managing. Female, older age, low educational level, living in central and western China, chronic diseases and disability were factors associated with ADL loss and IADL loss; the divorced or separated, widowed were more likely to have ADL loss; people living in rural area were more likely to have IADL loss. Conclusion: It is necessary to take comprehensive measures to delay and reduce the ADL and IADL loss in elderly Chinese and provide timely and appropriate health care for the elderly with ADL or IADL loss.


Assuntos
Atividades Cotidianas , Pessoas com Deficiência , Idoso , Idoso de 80 Anos ou mais , China , Doença Crônica , Feminino , Humanos , Estudos Longitudinais , Masculino , Prevalência
10.
Trop Biomed ; 33(2): 285-289, 2016 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33579095

RESUMO

Scarce information is available about the seroprevalence of Toxoplasma gondii (T. gondii) and Neospora caninum (N. caninum) infections in goats in Hubei province, China. In the present study, the prevalence of T. gondii and N. caninum infections in goats were investigated in Hubei province, China between 2014 and 2015. A total 2007 serum samples were collected from 6 counties of Hubei province, China and were tested for antibodies to N. caninum and T. gondii by an enzyme-linked immunosorbent assay (ELISA) and an indirect agglutination test (IAT), respectively. Antibodies against T. gondii and N. caninum were detected in 13.4% and 3.9%, respectively in goats. 2% (41) serum samples were positive to both parasites. There was no apparent association of T. gondii and N. caninum infection with gender of the animals. There were significant differences of T. gondii (p < 0.01), N. caninum (p < 0.05) and both parasites (p < 0.01) infection with season. This is the first time that antibodies to T. gondii and N. caninum have been detected in goats in Hubei province, China.

11.
Genet Mol Res ; 14(1): 21-8, 2015 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-25729931

RESUMO

We aimed to explore the changes of peripheral B1 cells before and after treatment of adult idiopathic thrombocytopenic purpura (ITP) and to investigate the association of these changes with the disease condition and prognosis. Ninety-seven ITP patients were divided into the effective or ineffective groups, based on their response to hormone therapy. Forty healthy volunteers were enrolled into the control group (HC). The percentages of CD19+ cells, B1 cells, and platelet-associated immunoglobulin (PAIg) in peripheral blood from healthy volunteers and ITP patients before and after treatment were evaluated, and blood platelet (PLT) counts were determined. The percentages of CD19+ cells [(21 ± 10.0) vs (11.2 ± 7.1)%], B1 cells [(8.85 ± 5.23) vs (2.2 ± 1.3)%], and PAIg [(28 ± 19) vs (11.7 ± 8)%] in whole blood from ITP patients before treatment were significantly higher than those in whole blood from healthy controls (P < 0.05). Before treatment, the percentage of B1 cells and PAIg in ITP patients was negatively correlated with the PLT level (r = -0.89, P < 0.05 and r = -0.814, P < 0.05, respectively). Further, the B1 cell percentage was positively associated with the PAIg percentage in ITP patients before treatment. In the effective group, the B1 cell percentage was reduced sharply at 1 month after treatment [(2.45 ± 1.75) vs (8.74 ± 5.04)%, P < 0.05)], so as at 3 and 6 months. However, in the ineffective group, there was no difference in the B1 cell percentage before and after treatment [(7.9 ± 5.6) vs (8.76 ± 5.26)%]. This obvious association of changes in peripheral B1 cells with disease condition and prognosis in ITP patients may be of certain clinical significance for guiding the individualized treatment of ITP.


Assuntos
Linfócitos B/imunologia , Medicina de Precisão , Púrpura Trombocitopênica Idiopática/imunologia , Púrpura Trombocitopênica Idiopática/terapia , Adolescente , Adulto , Idoso , Antígenos CD19/metabolismo , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Contagem de Plaquetas , Prognóstico , Púrpura Trombocitopênica Idiopática/sangue , Adulto Jovem
12.
Genet Mol Res ; 13(3): 7465-9, 2014 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-25222245

RESUMO

Metastatic tumors in the paranasal sinuses are very rare. The origin of metastatic tumors in the paranasal sinuses is often renal cancer. Renal cell carcinomas are known for their tendency for early metastasis, and symptoms due to the metastatic lesion may be the only initial manifestation. In this paper, we deal with the case of a 35-year-old male patient who presented with a mass in the left maxillary region. The presence of a primary renal cell carcinoma was recognized only after surgical removal of the metastatic tumor. The presentation, diagnosis and treatment of this tumor are discussed with a review of the literature.


Assuntos
Carcinoma de Células Renais/patologia , Neoplasias Renais/patologia , Neoplasias do Seio Maxilar/diagnóstico , Neoplasias do Seio Maxilar/secundário , Adulto , Biópsia , Humanos , Masculino , Neoplasias do Seio Maxilar/radioterapia , Tomografia Computadorizada por Raios X , Resultado do Tratamento
13.
Nat Commun ; 2: 394, 2011 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-21750547

RESUMO

High-temperature superconductivity in iron-arsenic materials (pnictides) near an antiferromagnetic phase raises the possibility of spin-fluctuation-mediated pairing. However, the interplay between antiferromagnetic fluctuations and superconductivity remains unclear in the underdoped regime, which is closer to the antiferromagnetic phase. Here we report that the superconducting gap of underdoped pnictides scales linearly with the transition temperature, and that a distinct pseudogap coexisting with the superconducting gap develops on underdoping. This pseudogap occurs on Fermi surface sheets connected by the antiferromagnetic wavevector, where the superconducting pairing is stronger as well, suggesting that antiferromagnetic fluctuations drive both the pseudogap and superconductivity. Interestingly, we found that the pseudogap and the spectral lineshape vary with the Fermi surface quasi-nesting conditions in a fashion that shares similarities with the nodal-antinodal dichotomous behaviour observed in underdoped copper oxide superconductors.


Assuntos
Arsenicais/química , Condutividade Elétrica , Temperatura Alta , Ferro/química , Magnetismo , Espectroscopia Fotoeletrônica
14.
Nat Commun ; 1: 112, 2010 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-21081910

RESUMO

The central issues for understanding iron (Fe)-based superconductors are the symmetry and structure of the superconducting gap. So far the experimental data and theoretical models have been highly controversial. Some experiments favor two or more constant or nearly constant gaps, others indicate strong anisotropy and yet others suggest gap zeros ('nodes'). A unique method for addressing this issue, and one of very few methods that are bulk and angle resolved, is measuring the electronic-specific heat in a rotating magnetic field. In this study, we present the first such measurement for an Fe-based high-T(c) superconductor. We observed a fourfold oscillation of the specific heat as a function of the in-plane magnetic field direction. Our results are consistent with the expectations for an extended s-wave model, with a significant gap anisotropy on the electron pockets and the gap minima along the ΓM (Fe-Fe bond) direction.

15.
Phys Rev Lett ; 101(20): 207002, 2008 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-19113369

RESUMO

Through a combined scanning tunneling microscopy and angle-resolved photoemission spectroscopy study, we report the observation of two distinct gaps (a small and a large gap) that coexist both in real space and in the antinodal region of momentum space, below the superconducting transition temperature (T_{c}) of Bi_{2}Sr_{2-x}La_{x}CuO_{6+delta}. We show that the small gap is associated with superconductivity. The large-gap persists above T_{c}, and seems linked to observed charge ordering. We find a strong correlation between the large and small gaps suggesting that they are affected by similar physical processes.

16.
Artigo em Chinês | MEDLINE | ID: mdl-12567699

RESUMO

OBJECTIVE: To explore the persistence period of medium and higher density of microfilaremia and its role in the transmission of filariasis in areas with filariasis basically eradicated. METHODS: The residual microfilaremia was followed up and the population were regularly examined by thick blood film assay. Culex quinquefaciatus were dissected to determine the natural infection rate and density of filarial larvae. The filarial antibody levels were detected by using IFAT. RESULTS: Two cases with medium and higher density of microfilaremia were found to be microfilaremia positive for twelve years. The natural infection rate and density of filarial larvae in Culex quinquefasciatus dropped down year by year, one case of new microfilaremia was found in the sixteenth year. CONCLUSION: The persistence period of residual medium and higher density of microfilaremia lasted for more than twelve years. The individual residual medium and higher density of microfilaremia cases still possess the potential for transmission of filariasis.


Assuntos
Filariose/transmissão , Microfilárias , Wuchereria bancrofti , Animais , Culex/parasitologia , Feminino , Filariose/parasitologia , Humanos , Insetos Vetores/parasitologia , Masculino
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA