Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Hazard Mater ; 391: 122183, 2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-32036308

RESUMO

Metal-free catalysts have been proved to be a low-cost and environmentally friendly species in aerobic oxidative desulfurization (ODS). In this work, exfoliated metal-free boron carbide with few-layered structure, small size, and abundant defects, was first employed in an aerobic ODS system for ultra-deep desulfurization. The exfoliation process was realized by employing a planetary ball mill strategy. Detailed characterizations showed that the ball milling process not only induces thinner layers and small sizes but also introduces numerous defects into the boron carbide catalysts, which is vital in metal-free catalysis. Furthermore, the exfoliated boron carbide catalyst was applied in aerobic ODS system, and 99.5 % of sulfur removal was obtained. Moreover, the catalyst can be recycled 17 times without a significant decrease in catalytic activity. In particular, it was found that ∼90 % of the sulfur compounds in real diesel oil could be removed by the current aerobic ODS system.

2.
ACS Appl Mater Interfaces ; 11(40): 36666-36675, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31525889

RESUMO

Surface oxygen vacancy can greatly affect the properties of transition-metal oxides. However, engineering oxygen vacancy-abundant transition-metal oxides with high specific surface area (SSA) remains challenging. At present, the generation of oxygen vacancies in metal oxides is time-consuming and less environmentally friendly by chemical leaching methods that usually require additional waste treatment. Herein, a series of oxygen vacancy-abundant transition-metal oxides with high SSA are constructed via a lattice refining strategy. This strategy is realized by urea-assisted ball milling pyrolysis and is green, efficient, and universal. The oxygen vacancies promote the mobility of oxygen, leading to a boosted catalytic oxidation performance of aromatic sulfides. Such a strategy provides an efficient approach to manufacturing oxygen vacancies on transition-metal oxides, which may be beneficial for various related applications as an effective catalytic material.

3.
Nanotechnology ; 29(2): 025604, 2018 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-29155413

RESUMO

Hexagonal boron nitride has been regarded to be an efficient catalyst in aerobic oxidation fields, but limited by the less-exposed active sites. In this contribution, we proposed a simple green liquid nitrogen gas exfoliation strategy for preparation of porous monolayer nanosheets (BN-1). Owing to the reduced layer numbers, decreased lateral sizes and artificially-constructed pores, increased exposure of active sites was expected, further contributed to an enhanced aerobic oxidative desulfurization (ODS) performance up to ∼98% of sulfur removal, achieving ultra-deep desulfurization. This work not only introduced an excellent catalyst for aerobic ODS, but also provided a strategy for construction of some other highly-efficient monolayer two-dimensional materials for enhanced catalytic performance.

4.
Yale J Biol Med ; 90(4): 599-610, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29259524

RESUMO

Nature has invented photoreceptor proteins that are involved in sensing and response to light in living organisms. Genetic code expansion (GCE) technology has provided new tools to transform light insensitive proteins into novel photoreceptor proteins. It is achieved by the site-specific incorporation of unnatural amino acids (Uaas) that carry light sensitive moieties serving as "pigments" that react to light via photo-decaging, cross-linking, or isomerization. Over the last two decades, various proteins including ion channels, GPCRs, transporters, and kinases have been successfully rendered light responsive owing to the functionalities of Uaas. Very recently, Cas9 protein has been engineered to enable light activation of genomic editing by CRISPR. Those novel proteins have not only led to discoveries of dynamic protein conformational changes with implications in diseases, but also facilitated the screening of ligand-protein and protein-protein interactions of pharmacological significance. This review covers the genetic editing principles for genetic code expansion and design concepts that guide the engineering of light-sensitive proteins. The applications have brought up a new concept of "optoproteomics" that, in contrast to "optogenetics," aims to combine optical methods and site-specific proteomics for investigating and intervening in biological functions.


Assuntos
Aminoácidos/química , Optogenética/métodos , Engenharia de Proteínas/métodos , Proteômica/métodos , Aminoácidos/genética , Animais , Edição de Genes , Código Genético , Humanos , Mutagênese Sítio-Dirigida , Fotoquímica/métodos , RNA de Transferência , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
5.
Oncotarget ; 8(42): 72044-72053, 2017 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-29069767

RESUMO

PURPOSE: Chronic hepatitis C virus (HCV) infection is reported to be associated with early-onset breast cancer, while, as a hepadnavirus, hepatitis B virus(HBV) infection is more common than HCV in China. In this article, it is aimed to study the relationship between HBV infection and risk of breast cancer in China. METHODS: The clinical data of 2452 cases of initially diagnosed breast cancer and 1926 cases of benign breast disease (as controls) with the consecutive reports of HBV serological markers and liver function tests, available in the Electronic Medical Records of the Breast Cancer Center of Chongqing, the southwest of China, from January 2011 to March 2015, were collected for analysis. RESULTS: The average age of the initially diagnosed breast cancer patients was 50.3±11.3 years with the age peaking about 40- 49yeaers (39.7%). The positive rate (8.2%) of hepatitis B surface antigen in breast cancer patients was relatively higher than that (7.8%) in controls (P>0.05). While, the positive rate (66.4%)of hepatitis B core antibody in breast cancer patients was significantly higher than that (53.7%) in controls (P<0.05), so were the similar results in the age groups of 40-49 years, after multiple layer analysis stratified by age and compare HBV markers adjusting age with binary logistic regression. Meanwhile, the status of albumin, aminotransferase and aspartate transaminase (41.4 g/L, 22.9 U/L, 22.0 U/L) in breast cancer patients were significantly poorer than those (44.1 g/L,16.8 U/L, 19.2 U/L) in controls (P<0.05). CONCLUSIONS: Exposure to HBV infection may be a risk factor for breast cancer and may be also related to the earlier age onset of breast cancer (peaked around 40-49 years) among Chinese females.

6.
Oncotarget ; 8(11): 18185-18190, 2017 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-28212549

RESUMO

We performed a case-control study to investigate the prevalence and clinicopathological features of breast cancer patients with hepatitis B virus (HBV) infection in China. The clinical data for 2,796 female patients with newly diagnosed, primary breast cancer were evaluated. A total of 234 breast cancer patients with HBV infection (the case group; positive for hepatitis B surface antigen [HBsAg]) and 444 breast cancer patients without HBV infection (the control group; negative for HBsAg, hepatitis B surface antibody, hepatitis B envelope antigen, hepatitis B envelope antibody, and hepatitis B core antibody) were selected for study. Analysis of the clinicopathological features revealed that the metastatic axillary lymph node ratio was lower in the case group than the control group, as was the proportion of patients with pathological T stage ≥T2. No differences in the expression levels of estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, p53, or Ki67 were observed between the case and control groups. These data indicate that the rate of HBV infection is high among female breast cancer patients in China, and that HBsAg-positive breast cancer patients were generally diagnosed at an earlier stage and had fewer lymph node metastases.


Assuntos
Neoplasias da Mama/virologia , Hepatite B/patologia , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/patologia , Estudos de Casos e Controles , China/epidemiologia , Feminino , Hepatite B/epidemiologia , Hepatite B/virologia , Humanos , Fatores de Risco
7.
J Biomed Res ; 2017 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-29770779

RESUMO

This study was designed to investigate the effect of neoadjuvant chemotherapy on the expression of hormone receptors and ki67 in Chinese female breast cancer patients. The expression of estrogen receptor (ER), progesterone receptor (PR) and Ki67 among 525 neoadjuvant chemotherapy cases was studied by immunohistochemistry (IHC). Differences between specimens made through preoperative core needle biopsy (CB) and excised tissue biopsy (EB) were observed. The positive rates of ER, PR and Ki67 in CB and EB were 65.3 and 63.2%, 51.0% and 42.6%, 65.6% and 43.4% respectively. The expression of ER, PR and Ki67 in CB and EB had no statistically significant difference. However, after neoadjuvant chemotherapy, the discordance rates of ER, PR and Ki67 were 15.2% (79/521), 26.9% (140/520), and 44.8% (225/502), respectively. The ER, PR, and Ki67 status changed from positive to negative in 7.5% (39/521), 13.3% (69/520), and 21.1% (106/502) of the patients, whereas ER, PR and Ki67 status changed from negative to positive in 7.7% (40/521), 13.6% (71/520), and 23.7% (119/502) of the patients, respectively. These results showed that the status of some biomarkers changes after neoadjuvant chemotherapy and biomarker status needs to be reexamined to optimize adjuvant systemic therapy and better prognosis assessment.

8.
Chin Clin Oncol ; 5(6): 81, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27701872

RESUMO

Lifestyle and family history are two of the most important risk factors for breast cancer (BC). However, these risk factors cannot explain the differences in the incidence and early BC onset among Chinese females compared to their western counterparts. We propose in this hypothesis the potential mechanism of indirect oncogenesis of hepatitis B virus (HBV) in causing BC through its persistence as occult infection and continuous replication with long term subtle liver damage. Estrogen is mainly deactivated in the liver and long term necro-inflammatory damage to liver may result in persistent high level of estrogen, which is a dominant risk factor for BC. HBV may also directly affect the breast cells through its cis and trans effects of HBx which may act as oncoprotein. Given the recognised aetiologic association between oestrogen and breast cancer risk, there is biological plausibility that dietary soy and vegetable intake which is rich in the Chinese diet may have anti-carcinogenic effect on the breast. The seemingly conflicting phenomenon of early age onset and lower BC incidence in China might be due to wide imbalance in the amount of exposure to carcinogenic factor (e.g., HBV infection) for decades and the carcinoprotective exposure levels (e.g., isoflavonoids and flavonoids intake). For example, the increase in carcinoprotective levels would lead to lower incidence of breast cancer and vice versa. Although the focus of this personal view is on HBV, this by no means negates the roles of other known risk factors in breast-cancer development. Characterisation of the role of HBV in BC could potentially benefit Chinese females by decreasing incidence and increasing overall survival.


Assuntos
Neoplasias da Mama/virologia , Vírus da Hepatite B/isolamento & purificação , Hepatite B/patologia , Neoplasias da Mama/patologia , Hepatite B/virologia , Humanos , Fatores de Risco
9.
Med Oncol ; 31(5): 956, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24729160

RESUMO

To estimate the status of ß-cell dysfunction and insulin resistance of breast cancer (BC) patient without history of diabetes mellitus (DM) after systemic treatment through an oral glucose tolerance test (OGTT) and insulin releasing test (IRT). All the 128 BC patients without history of DM after systemic treatment underwent OGTT and IRT test. Fasting and 2-h glucose levels were measured to confirm undiagnosed DM and prediabetes. Insulin sensitivity was estimated by homeostasis model assessment of insulin resistance (HOMA-IR) and Matsuda index and disposition index (IGI/HOMA-IR). Insulin secretion was estimated by the insulinogenic index (IGI) [Δ insulin/Δ glucose (30-0 min)]. Insulin concentrations during the OGTT and IRT at baseline were used to derive the patterns of insulin secretion curve (pattern 1, pattern 2, pattern 3, pattern 4 and pattern 5), which were used to estimate the risk of developing DM. Of 128 BC patients without history of DM after systemic treatment, there were 46 cases (35.9%) of NGT, 60 cases (46.9%) of prediabetes and 22 cases (17.2%) of DM. The BMI of prediabetes and DM were higher than NGT groups with statistical significance. After adjusted for BMI, IGI was significantly lower in DM group but not significantly different between NGT group and prediabetes group. HOMA-IR, Matsuda index and disposition index were significantly different in DM group compared with NGT group and prediabetes and also significantly different between NGT and prediabetes groups. The total rates of patterns 4 and 5 in NGT and prediabetes groups were 15.3% (10.9 and 4.4%) and 48.3% (31.6 and 16.7%), respectively. ß-Cell dysfunction and insulin resistance may appear in BC patients after systemic treatment. BC patients have high risk in development of DM even in NGT and prediabetes groups confirmed by OGTT.


Assuntos
Neoplasias da Mama/complicações , Diabetes Mellitus Tipo 2/diagnóstico , Resistência à Insulina , Células Secretoras de Insulina/patologia , Estado Pré-Diabético/diagnóstico , Glicemia/análise , Neoplasias da Mama/patologia , Neoplasias da Mama/terapia , Terapia Combinada , Diabetes Mellitus Tipo 2/etiologia , Feminino , Seguimentos , Teste de Tolerância a Glucose , Humanos , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Estado Pré-Diabético/etiologia , Prognóstico , Fatores de Risco
10.
PLoS One ; 9(4): e93630, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24690937

RESUMO

AIMS: This study is to estimate the status and comparison of glucose intolerance in female breast cancer patients at initial diagnosis and during chemotherapy through an oral glucose tolerance test (OGTT), as well as to learn the effect of chemotherapy on the glucose metabolism of breast cancer patients. METHODS: All the 79 breast cancer patients at initial diagnosis, with the mean age of 53.2 years, and 96 breast cancer patients before the 5th or 6th cycle of chemotherapy, with the mean age of 51.5 years, participated in the study from December 2012 to October 2013. After an overnight fast, participants underwent OGTT test, and fasting and 2-hour glucose levels were measured to identify undiagnosed diabetes and prediabetes (i.e., impaired fasting glucose or impaired glucose tolerance) in them. Previously diagnosed diabetes among the female breast cancer patients was determined on the self-report and the medical record. RESULTS: The overall incidences of total normal glucose tolerance, prediabetes, diabetes in female breast cancer patients at initial diagnosis and during chemotherapy were 24.1% and 38.5% (p<0.05), 50.6% and 28.1% (p<0.05), and 25.3% and 33.3% (p>0.05), respectively, and the differences of normal glucose tolerance and prediabetes instead of diabetes between the two groups were statistically significant. About 84% of the total diabetes and prediabetes in the female breast cancer patients at initial diagnosis and 79.7% of those during chemotherapy need to be diagnosed with OGTT. CONCLUSIONS: Breast cancer patients have high incidences of diabetes and prediabetes. After chemotherapy even with steroids, some breast cancer patients with abnormal glucose metabolism may even become normal. Isolated hyperglycemia 2 hours after glucose loading is common, and OGTT should be made for breast cancer patients at initial diagnosis and during chemotherapy.


Assuntos
Neoplasias da Mama/patologia , Diabetes Mellitus Tipo 2/patologia , Intolerância à Glucose/patologia , Estado Pré-Diabético/patologia , Idoso , Neoplasias da Mama/complicações , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/etiologia , Diabetes Mellitus Tipo 2/metabolismo , Feminino , Glucose/metabolismo , Intolerância à Glucose/complicações , Intolerância à Glucose/diagnóstico , Teste de Tolerância a Glucose , Humanos , Pessoa de Meia-Idade , Estado Pré-Diabético/etiologia , Estado Pré-Diabético/metabolismo , Fatores de Risco
11.
Med Oncol ; 31(1): 788, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24338167

RESUMO

The aim of this study was to study the prevalence and clinicopathologic features of breast cancer patients with type 2 diabetes mellitus in southwest of China for providing clinical guidance and prognosis appreciation for these patients. Through a case-control study of 3,381 primary breast cancer patients initially diagnosed from January 2007 to May 2013, one case group (164 female breast cancer patients with type 2 diabetes) and two control groups (first control group consists of 328 randomly selected nondiabetic breast cancer patients and second control group consists of 279 nondiabetic breast cancer patients without diabetes-related diseases such as cardiovascular or cerebrovascular diseases) were selected. The clinicopathological features between them were statistically analyzed. (1) Of 3,381 primary breast cancer patients with the average age of 50.5, ranging from 21 to 97 years of age, 164 (4.9 %) cases (with the average age of 60.7) suffered diabetes (previously diagnosed diabetes). (2) The differences of clinicopathologic features between the case group and first control group (with the average age of 61.5) were the ratio of hypertension (41.5 vs 26.1 %, P = 0.001) and axillary lymph node metastasis (51.1 vs 38.1 %, P = 0.046); and the differences of clinicopathologic features between the case group and second control group (with the average age of 64.3) were axillary lymph node metastasis (51.1 vs 35.8 %, P = 0.017), tumor size (≥ T2: 62.3 vs 53.1 %, P = 0.019) and p53 expression (51.0 vs 62.7 %, P = 0.018). No statistical significances (P > 0.05) of histological type, histological grade, or the expressions of estrogen receptor (ER), progesterone receptor, human epidermal growth factor 2 (HER2) and Ki67 were found between them. (3) The clinicopathologic features of ER-positive and ER-negative patients in each group were as follows: (1) In the case group, the ER-negative patients have more advanced tumor histological grade (G3, 19.0 vs 2.8 %, P = 0.012), more positive expression of Her-2 (16.9 vs 8.1 %, P = 0.029) and more axillary lymph node metastasis (63.3 vs 44.4 %, P = 0.048). (2) In the first control group, the same results with tumor histological grade (G3, 15.6 vs 6.2 %, P = 0.025) and positive expression of Her-2 (16.7 vs 4.3 %, P = 0.001), and more positive expression of Ki67 (65.1 vs 52.0 %, P < 0.001) were found. (3) In the second control group, the ER-negative patients have more positive expression of Ki67 (70.5 vs 55.7 %, P = 0.009) and fewer family history of malignancy (1.9 vs 10.0 %, P = 0.013). Diabetes has a high incidence in breast cancer patients and is more common with postmenopausal patients. It is suggested that initially diagnosed breast cancer patients should undertake oral glucose tolerance test screening for occult diabetes and prediabetes. More concerns should be put onto diabetic patients with breast cancer.


Assuntos
Neoplasias da Mama/epidemiologia , Complicações do Diabetes/diagnóstico , Diabetes Mellitus Tipo 2/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/complicações , Estudos de Casos e Controles , China , Diabetes Mellitus Tipo 2/complicações , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Hipertensão/complicações , Incidência , Antígeno Ki-67/metabolismo , Metástase Linfática , Pessoa de Meia-Idade , Prognóstico , Receptor ErbB-2/metabolismo , Receptores Estrogênicos/metabolismo , Receptores de Progesterona/metabolismo , Fatores de Risco , Adulto Jovem
12.
Med Oncol ; 31(1): 798, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24307349

RESUMO

Discordance of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) status between primary breast cancer, metastatic lesion and synchronous axillary lymph node metastasis has been reported in the series studies. Systemic treatment of primary invasive breast cancer patients with synchronous axillary metastasis is currently based on the biomarker characteristics of the primary tumor; however, hormone receptors and HER2 status may change throughout tumor progression from the primary tumor to the synchronous axillary metastasis. As local metastasis, the synchronous axillary lymph node metastasis may represent the potentially metastatic breast cancer cells much better than the primary tumor. Hence, the determination of hormone receptors and HER2 status should be routinely performed in synchronous axillary nodal metastasis, together with primary tumor, to guide therapy management and evaluate the recurrent risk of primary invasive breast cancer patients with synchronous axillary nodal metastasis, which may even change the postoperative risk categories (St. Gallen consensus) of breast cancer in these patients. This article will review the studies on the discordance and clinical significance of ER, PR, and HER2 receptor status between primary breast cancer and synchronous axillary lymph node metastasis.


Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Receptor ErbB-2/metabolismo , Receptores Estrogênicos/metabolismo , Receptores de Progesterona/metabolismo , Biomarcadores Tumorais/metabolismo , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Linfonodos/metabolismo , Metástase Linfática , Recidiva , Risco
13.
Med Oncol ; 30(3): 687, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23925668

RESUMO

Patients with cancer frequently show glucose intolerance. This study is to estimate the status of total diabetes and prediabetes in breast cancer patients after systemic treatment through an oral glucose tolerance test (OGTT) in China. All the 119 breast cancer patients more than 3 months after systemic treatment with surgery and chemotherapy participated in the study. All the patients without the diagnosis of diabetes underwent OGTT, and fasting and 2-h glucose levels were measured to identify undiagnosed diabetes and prediabetes. Previously diagnosed diabetes were determined on the self-report and the medical record. Of the 119 breast cancer patients, with the median age of 50.1 years and the mean age of about 48 years when they were initially diagnosed with breast cancer, which showed the similar characters of China and Asia breast cancer patients, the overall incidences of total diabetes and prediabetes were 21.8 and 43.7 %, respectively. About 80 % of the diabetes were previously undiagnosed. About 80.0 % of the cases of undiagnosed diabetes and prediabetes met the criteria for elevated 2-h plasma glucose levels through OGTT but not the criteria for elevated fasting glucose levels. Our study firstly documents high incidences of previously undiagnosed diabetes and prediabetes in breast cancer patients during follow-up after systemic treatment through OGTT, indicating that greater diabetes screening, especially through OGTT, prevention, and treatment strategies among breast cancer patients, after systemic treatment for these patients is needed.


Assuntos
Neoplasias da Mama/complicações , Neoplasias da Mama/tratamento farmacológico , Diabetes Mellitus/epidemiologia , Estado Pré-Diabético/epidemiologia , Adulto , Idoso , Glicemia/metabolismo , Neoplasias da Mama/sangue , Neoplasias da Mama/metabolismo , Diabetes Mellitus/sangue , Diabetes Mellitus/metabolismo , Jejum/metabolismo , Feminino , Intolerância à Glucose/metabolismo , Teste de Tolerância a Glucose/métodos , Humanos , Incidência , Pessoa de Meia-Idade , Estado Pré-Diabético/sangue , Estado Pré-Diabético/metabolismo , Fatores de Risco
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA