Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
2.
PLoS One ; 18(4): e0284269, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37053236

RESUMO

The effect of soil fixation and anti-scour instability of slope vegetation generally depends on the strength and anti-disintegration ability of slope soil due to increase of root system. Therefore, it is particularly necessary to study the disintegration characteristics of expansive soil related to slope instability under acidic conditions (simulated acid rain). In this paper, the response surface method (RSM) was used with the pH value, root diameter, root length, root coefficient, and distribution as independent variables, and the disintegration amount of root-soil (DARS) after 60min as the response value. Then X-ray diffractometer (XRD) was used to analyze the mineral composition changes of the sample under this environment. Simultaneously, the plasticity index of expansive soil at different values of pH was studied to discuss the disintegration mechanism of root compound expansive soil in an acid environments. The results show that the root system improves the anti-disintegration characteristics of the root-soil, and the effects of various factors on the amount of disintegration were as follows: root length > pH value > root distribution > root amount > root diameter. The DARS with a length of 20mm increased by 26.67% and 41.56% compared to the 30mm and 40mm. Compared to the horizontal distribution and horizontal + slant distribution, the DARS with slant distribution was increases by 11.39% and 20.24% respectively. The DARS with 2 roots is increased by 9.92% and 16.75% compared to 4 and 6 roots respectively. The 1mm diameter DARS is 6.65% and 15.49% higher than the 2mm and 3mm, respectively. In addition, an acidic environments can lead to an increase in the amount of disintegration or rate of disintegration. The disintegration at pH = 4.2 was increased by 11.4% and 22.4% compared to pH = 5.6 and pH = 7, respectively. The acidity affects soil disintegration is due to the hydrophilic minerals in the expansive soil react with H+ ion in the acid solution to form soluble salts. Due to the dissociation and leaching of free quartz and metal oxides in the soil to varying degrees, the ability of expansive soil to accumulate is reduced. The intensity of erosion and leaching decreases with increasing pH. In addition, the pH value can affects the plasticity index of the soil, which increases with the increasing pH, thus affects the disintegration properties of the expansive soil.


Assuntos
Chuva Ácida , Poluentes do Solo , Solo/química , Óxidos , Poluentes do Solo/análise
4.
Acta Chim Slov ; 69(4): 913-919, 2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36562166

RESUMO

A bis-Schiff base N,N'-ethylene-bis(3-bromosalicylaldimine) (H2L) was prepared from 3-bromosalicylaldehyde and ethane-1,2-diamine. With H2L as ligand, a new copper(II) complex [CuL] (1) and a new cobalt(III) complex [CoL(NCS)(DMF)] (2) were prepared and characterized by physico-chemical methods and single crystal X-ray analysis. X-ray analysis indicates that the Cu atom in complex 1 is in square planar coordination, and the Co atom in complex 2 is in octahedral coordination. The compounds were tested in vitro for their antibacterial activities on Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas fluorescens. Both complexes have effective activities on the bacteria.


Assuntos
Complexos de Coordenação , Cobre , Antibacterianos/farmacologia , Antibacterianos/química , Bactérias , Cobalto/química , Complexos de Coordenação/farmacologia , Complexos de Coordenação/química , Cobre/química , Cristalografia por Raios X , Etilenos , Bases de Schiff/química
5.
J Diabetes Investig ; 12(4): 566-573, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32797727

RESUMO

AIMS/INTRODUCTION: Vaspin is linked to obesity and its metabolic abnormalities. However, the role of vaspin serum levels in diabetic retinopathy (DR) is unknown. In the present study, we investigated the association between serum levels of vaspin and both DR and vision-threatening DR. MATERIALS AND METHODS: This was a cross-sectional single-center observational study from December 2018 to September 2019. We evaluated circulating serum levels of vaspin in 372 participants with type 2 diabetes. DR was screened through detailed ocular examination. DR patients were also divided two groups: vision-threatening DR and non-vision-threatening DR. The relationship between vaspin and DR was investigated by univariate and multivariate logistic regression analyses, and the results are shown as odds ratios with 95% confidence intervals. RESULTS: The vaspin serum levels of 372 patients were obtained, with a median value of 1.50 ng/mL (interquartile range 0.94-2.18 ng/mL). The median age of those patients was 53 years (interquartile range 44-62 years), and 44.4% were women. Patients with DR and VDTR had significantly increased vaspin serum levels (P < 0.001 andP < 0.001). A multivariable regression model found that patients with high levels of vaspin were approximately 1.85-fold (odds ratio for per unit increase 1.85, 95% confidence interval 1.43-2.55; P < 0.001) more likely to experience DR, and 3.76-fold (odds ratio for per unit increase 3.76, 95% confidence interval 2.05-6.55; P < 0.001) more likely to experience VTDR. The predictive value of vaspin was stronger in women than in men. CONCLUSION: Higher vaspin serum levels were associated with an increased risk of DR and VDTR in patients with type 2 diabetes, which showed that vaspin is an important indicator factor for DR.


Assuntos
Diabetes Mellitus Tipo 2/complicações , Retinopatia Diabética/sangue , Serpinas/sangue , Adulto , Estudos Transversais , Diabetes Mellitus Tipo 2/sangue , Retinopatia Diabética/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
6.
PLoS One ; 15(12): e0244818, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33382833

RESUMO

Grassroots have received more attention than the traditional method as soil reinforcement materials, especially the use of vetiver and other vegetation protection methods to treat expansive soil slope, have been tried and applied. To study the influence of grassroots on the strength properties of expansive soil, the laws of vetiver root growth over time and its vertical distribution of root content(δ) were firstly investigated by the experiment of planting vetiver. Then different δ and depth of planted soil were obtained. Simultaneously different δ and water content(ω) of grafted soil were made. With the direct shear test, the shear strength parameters of root-soil with different δ were analyzed. The shear test on root-soil composites with different δ was carried out to compare the strength characteristics of planted and grafted soil. The results showed that the δ of vetiver decreased with the increase of depth, and the δ of each layer increased with the growth period. The δ of 180d was 70.5% higher than that of 90d. The cohesion(c) of root-soil can be increased by more than 97%, and internal friction angle(φ) can be increased by more than 15.4% after 180 days. The c of 90 d vetiver root system can be increased by more than 18%, and the φ can be increased by more than 1.5%. At each depth, the c and φ of composite soil increases with the increase of δ, and the increment of cohesion (Δc) and the increment of internal friction angle (Δφ) increase with the increment of δ. But the increase in the ω will weaken the shear strength parameters of root-soil. Under the condition of the planted root system and grafted root system, the influence degree of δ on strength parameter of root-soil is different, and the law of strength parameters versus δ of grafted soil of 365d is similar to that of planted soil of 90d. And the root reinforcement of grafted soil is weaker than planted soil. Hence the grafted soil can´t accurately reflect the root-soil interaction of the existing root system.


Assuntos
Vetiveria/fisiologia , Raízes de Plantas/fisiologia , Solo , Resistência ao Cisalhamento
7.
Opt Express ; 28(5): 6469-6489, 2020 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-32225894

RESUMO

A bound state between a quantum emitter (QE) and surface plasmon polaritons (SPPs) can be formed, where the excited QE will not relax completely to its ground state and is partially stabilized in its excited state after a long time. We develop some theoretical methods for investigating this problem and show how to form such a bound state and its effect on the non-Markovian decay dynamics. We put forward an efficient numerical approach for calculating the analytical part of the self-energy for frequency below the lower energy threshold. We also propose an efficient formalism for obtaining the long-time value of the excited-state population without calculating the eigenfrequency of the bound state or performing a time evolution of the system, in which the probability amplitude for the excited state in the steady limit is equal to one minus the integral of the evolution spectrum over the positive frequency range. With the above two quantities obtained, we show that the non-Markovian decay dynamics of an initially excited QE can be efficiently obtained by the method based on the Green's function expression for the evolution operator when a bound state exists. A general criterion for identifying the existence of a bound state is presented. The performances of the above methods are numerically demonstrated for a QE located around a metal nanosphere and in a gap plasmonic nanocavity. Numerical results show that these methods work well and the QE becomes partially stabilized in its excited state at a long time for the transition dipole moment beyond its critical value. In addition, it is also found that this critical value is heavily dependent on the distance between the QE and the metal surface, but nearly independent on the size of the nanosphere or the rod. Our methods can be utilized to understand the suppressed decay dynamics for a QE in an open quantum system and provide a general picture on how to form such a bound state.

8.
Opt Express ; 26(2): 1390-1401, 2018 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-29402013

RESUMO

We provide numerical demonstrations of the applicability and accuracy of the quasi-static method and the finite-element method in the investigation of the modifications of the spontaneous emission rate and the energy level shift of an emitter placed near a silver-air interface or a silver nano-sphere. The analytical results are presented as a reference. Our calculations show that the finite element method is an accurate and general method. For frequency away from the radiative mode, the quasi-static method can be applied more effectively for calculating the energy level shift than the spontaneous emission rate. But for frequency around, there is a blue shift for both and this shift increases with the increasing of emitter-silver distance. Applying the theory to the nanosphere dimmer, we see similar phenomenon and find extremely large modifications of the spontaneous emission rate and energy level shift. These findings are instructive in the fields of quantum light-matter interactions.

9.
Oncotarget ; 8(38): 63780-63787, 2017 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-28969028

RESUMO

Cytosine5-hyxymethylation (5hmC)which is a new epigenetic modification form plays important roles in the development and progression of tumors. In the present study, we observed that levels of 5hmC in the promoter region of Von Hippel-Lindau (VHL) were lower in 97 samples of renal clear cell carcinoma tissue than in matched adjacent benign tissues. Moreover, when the cancer tissue samples were divided based on pathological staging, VHL expression and the level of 5hmC in the VHL promoter were both lower in pathological grade III tumors than in grades I or II. Correspondingly, expression of TET1, which catalyzes the formation of 5hmC, was also lower in grade III renal clear cell carcinomas than in grade I or II disease. These findings suggest the 5hmC level on VHL is a key determinant of the gene's expression and may participate in the occurrence and development of renal clear cell carcinoma. Thus the 5hmC level may be a useful indicator for early diagnosis and appropriate treatment of renal clear cell carcinoma.

10.
Yao Xue Xue Bao ; 51(10): 1564-71, 2016 10.
Artigo em Chinês | MEDLINE | ID: mdl-29932601

RESUMO

The research aimed to investigate the suppression effect of Mai Shu which contains hawthorn, hippophae, medlar, phytosterols(ß-sitosterol, stigmasterol and campesterol), ß-glucan and lycopeneon formation of atherosclerotic plaque in apolipoprotein E knock-out (ApoE-/-) mice. Liquid chromatography-ultravioletmass spectrometry(LC-UV-MC) methods were used to analyze the main chemical composition of Mai Shu. Atherosclerotic mice models were established by high-fat diet. The mice were administrated with Mai Shu (1, 2, 4 g·kg-1·d-1) or other contrast materials by intragastric route for 10 weeks continuously. At the end of administration, the blood of mice was collected for tests of the serum total cholesterol(TC), total triglyceride(TG) and high density lipoprotein cholesterol(HDL-C) level. Atherosclerotic lesions in aorta and aortic root were assessed by calculating the relative area of lesions(oil red O stained). Intravital fluorescence microscopic system was used to evaluate the leukocyte-endothelial adhesion in mesenteric artery of mice by detecting the rolling velocity of white blood cells(WBC). Collagenous fibers and macrophages in lesions were detected by sirius red staining and immunological histological chemistry to evaluate the atherosclerotic plaque stability. Results showed that Mai Shu contains various flavonoids(9.5%), phytosterols(23.8%) and polysaccharides(8.9%). The serum lipid level of model animals was significantly higher than the control animals. Serum TC level was decreased by Mai Shu (4 g·kg-1, P < 0.001) compared to the untreated model. Serum TG level was reduced by Mai Shu (1, 2, 4 g·kg-1) compared to model(P < 0.01). Area of atherosclerotic lesions in aorta and aortic root was decreased in Mai Shu group (aorta: 1 g·kg-1, P < 0.05; 2 g·kg-1, P < 0.01; 4 g·kg-1, P < 0.001; aortic root: 2, 4 g·kg-1, P < 0.01). Rolling velocity of white blood cells of Mai Shu (4 g·kg-1, P < 0.001) group was increased over the untreated model. Collagenous fibers in lesions were observationally increased by Mai Shu (1, 2 g·kg-1) and macrophages were decreased (2, 4 g·kg-1) compared to model. These results demonstrate that Mai Shu can obviously decrease the serum lipid levels and the risk of leukocyte-endothelial adhesion in ApoE-/- mice. The effect of Mai Shu may be associated with the decrease of macrophages in plaque.


Assuntos
Aterosclerose/tratamento farmacológico , Medicamentos de Ervas Chinesas/farmacologia , Placa Aterosclerótica/tratamento farmacológico , Animais , Aorta/patologia , Colesterol/sangue , Dieta Hiperlipídica , Modelos Animais de Doenças , Macrófagos/citologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout para ApoE , Fitosteróis/farmacologia , Triglicerídeos/sangue
11.
Zhonghua Yi Xue Za Zhi ; 90(31): 2193-7, 2010 Aug 17.
Artigo em Chinês | MEDLINE | ID: mdl-21029659

RESUMO

OBJECTIVE: To investigate the polymorphism of human leukocyte antigen (HLA)-DRB1 and -DQB1 alleles among young women with cervical squamous cell carcinoma (SCC) and elucidate its relationship with human papillomavirus (HPV) type 16 infection. METHODS: From January 2005 to August 2009, 166 women diagnosed with cervical SCC at our hospital were enrolled. These patients were divided into two groups based on age, including 59 cases in young age group (≤ 35 yrs) and 107 cases in non-young age group. In the mean time, 50 cases with uterine myoma treated by hysterectomy were selected as controls. HPV 16 DNA in cervical tissues was amplified by polymerase chain reaction (PCR). HLA-DRB1 and -DQB1 typing were carried out by PCR-sequence specific primer (PCR-SSP) and the allele frequencies calculated. RESULTS: (1) The allele frequency of HLA DQB1*0301 at 29.6% was detected among HPV 16 positive cervical SCC cases in young age group. And it was significantly higher than 12.9% of non-young age group (P < 0.05). The allele frequencies of HLA-DRB1*04 and -DRB1*09 were significantly higher among HPV 16 negative cervical SCC cases in young age group as compared with non-young age group (14.1%, 26.6% vs 5.9%, 10.5%) (P < 0.05). The HLA-DRB1*07 allele was not detected among HPV 16 negative cervical SCC cases in young age group, But 14 cases (9.2%) were detected in non-young age group (P < 0.05). (2) The allele frequencies of HLA-DQB1*0501 at 7.4% and 6.3% respectively were detected among HPV 16 positive and negative cervical SCC cases in the young age group. And they were significantly lower than 25.8% and 20.4% of non-young age group (P < 0.05). CONCLUSION: The distribution patterns of HLA-DRB1 and -DQB1 alleles among young women with cervical SCC are different from those of older ones. And it has something to do with the HPV 16 infection status.


Assuntos
Carcinoma de Células Escamosas/virologia , Antígenos HLA-DQ/genética , Antígenos HLA-DR/genética , Papillomavirus Humano 16/patogenicidade , Neoplasias do Colo do Útero/virologia , Adulto , Fatores Etários , Alelos , Carcinoma de Células Escamosas/genética , Feminino , Frequência do Gene , Cadeias beta de HLA-DQ , Cadeias HLA-DRB1 , Humanos , Pessoa de Meia-Idade , Polimorfismo Genético , Neoplasias do Colo do Útero/genética , Adulto Jovem
12.
Zhonghua Yi Xue Za Zhi ; 88(38): 2683-4, 2008 Oct 21.
Artigo em Chinês | MEDLINE | ID: mdl-19080686

RESUMO

OBJECTIVE: To study the expression of cyclooxygenase-2 (COX-2) in bladder transitional cell carcinoma (Tcc) and the clinical significance thereof. METHODS: Immunohistochemistry was used to detect the expression of COX-2 in 56 specimens of bladder Tcc and 10 specimens of normal bladder tissue, all resected during operation. RESULTS: No expression of COX-2 was detected in the 10 specimens of normal bladder tissue and in the 56 specimens of bladder Tcc the positive rate of COX-2 was 55.36%. The expression of COX-2 in bladder Tcc was closely correlated with the grade and stage of tumor (both P < 0.01). CONCLUSION: COX-2 expression in bladder Tcc is closely correlated with the grade and stage.


Assuntos
Carcinoma de Células de Transição/metabolismo , Ciclo-Oxigenase 2/biossíntese , Neoplasias da Bexiga Urinária/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células de Transição/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias da Bexiga Urinária/patologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA