ABSTRACT The selection of key additive materials for a new type of oil-based drilling fluid was studied in this paper. The oil-based drilling fluid can strengthen well walls and ensure safety. It is suitable for high-temperature and high-pressure wells, deep wells and ultra-deep wells. A new type of high-temperature white oil-based drilling fluid was prepared by using 5# white oil as continuous phase, HIS as thickening agent, SDBS as emulsifier, and asphalt powder oxidized at 180°C as filtration agent. The results showed that the saturation concentration of sodium dodecyl benzene sulfonate (SDBS) was 4%, the saturation concentration of asphalt powder oxidized at 180°C was 4%, the saturation concentration of Tween-80 was 10%. The final resistance of high temperature and high pressure oil based drilling fluid formulation material is: No. 5 white oil + 4% SDBS + 5% modified bentonite + 4% asphalt powder oxidized at 180°C + 10% Tween-80 + 1.5% Barite + CaO. The performance evaluation of the new oil-based drilling fluid shows that shale expansion is 0.21mm, anti-temperature up to 220°C, and anti-pollution ability is good. The rheological properties, resistance of high-temperature high- pressure have been greatly improved. Therefore, the new white oil-based drilling fluid can resistance of high- temperature and also has low toxicity, which can meet the exploration and development of more complex wells.

Abstract Glutathione S-transferases (GSTs) are proteins synthesized in plants and responsible for their tolerance to environmental stresses. However, little information is available on the GST gene family of sweet potato, a globally important crop. The genetic evolution of GSTs in sweet potato remains unclear. The present study investigated the GST gene family in sweet potato by transcriptomic and comparative genomic analyses. A total of 51 GSTs were identified. Gene expression analysis showed differential expression patterns of the GSTs between two investigated varieties. Some GST expression levels were either up- or downregulated under oxidative, salinity and drought stresses. The results of the investigation provided new insights on the GST gene family in sweet potato, which may further the understanding of the roles of these genes in regulating abiotic stresses.

ABSTRACT Bentonite is the most important material used in oil and gas field drilling operations. However, the properties of natural bentonite cannot meet the requirements of bentonite for drilling. Therefore, researchers pay much attention to the modification of bentonite. The hydroxyethyl cellulose-acrylamide graft polymer was synthesized by microwave assisted, and the bentonite composite based on the graft polymer was prepared. FTIR, XRD and SEM results show that the polymer exists between the layers and the surface of the bentonite. Research on the bentonite composite showed that the yield point and filtration properties of bentonite composite are higher than natural bentonite at 90 to 150 celsius. The composite yield point / plastic viscosity ratio is more than 0.6 and the minimum fluid loss is only 9.3ml, which can meet the requirements of drilling-grade bentonite. This material has the potential to be a candidate for drilling applications.

Gallbladder cancer (GBC) is the most common malignancy in the biliary tract. Without effective treatment, its prognosis is notoriously poor. Tea polyphenols (TPs) have many pharmacological and health benefits, including antioxidant, anti-inflammatory, anti-tumor, anti-thrombotic, antibacterial, and vasodilatory properties. However, the anti-cancer effect of TPs in human gallbladder cancer has not yet been determined. Cell viability and colony formation assay were used to investigate the cell growth. Cell cycle and apoptosis were evaluated by flow cytometry analysis. Western blot assay was used to detect the expression of proteins related to cell cycle and apoptosis. Human tumor xenografts were used to examine the effect of TPs on gallbladder cancer cells in vivo. TPs significantly inhibited cell growth of gallbladder cancer cell lines in a dose- and time-dependent manner. Cell cycle progression in GBC cells was blocked at the S phase by TPs. TPs also induced mitochondrial-related apoptosis in GBC cells by upregulating Bax, cleaved caspase-3, and cleaved PARP expressions and downregulating Bcl-2, cyclin A, and Cdk2 expressions. The effects of TPs on GBC were further proven in vivo in a mouse xenograft model. Our study is the first to report that TPs inhibit GBC cell growth and these compounds may have potential as novel therapeutic agents for treating gallbladder cancer.

The water sorption, water barrier properties and mechanical behavior of soy protein isolate (SPI) based films combined with propylene glycol alginate (PGA) and lauric acid (La) via a direct- or co-dried blending process were investigated. Higher water retention ability and a single glass transition temperature (Tg) were found when the PGA was added to form different ternary co-dried blending films by a co-drying process, indicating their compatibility. Tg was reduced in the case of higher relative humidity and incorporation of La. The response surface methodology (RSM) indicated that the effect of La content was highly significant (p < 0.05) for the water retention ability and mechanical properties, and the proposed models calculated for the tensile strength and elongation at break showed a good fit. The results revealed the importance of the interactions among lipids, protein and polysaccharide in composite films which also provided evidence for modeling film behavior.

Abstract Streptococcus pneumoniae is one of the most frequent opportunistic pathogens worldwide. DNA processing protein A (DprA) is an important factor involved in bacterial uptake and DNA integration into bacterial genome, but its role in S. pneumoniae virulence remains unclear. The aim of this study was to characterize the effects of the pneumococcal dprA gene on the pathogenesis of S. pneumoniae. To construct a dprA-deficient pneumococcal strain, the dprA gene of the S. pneumoniae strain D39 was inactivated. The virulence of this dprA-deficient strain, designated ΔD39, was compared with that of the wild-type strain by evaluating their respective capabilities to adhere to human pulmonary epithelial cells (PEC-A549) and by analyzing their choline-binding protein expression levels. In addition, the expression profiles of genes associated with virulence and host survival assays were also conducted with the mutant and the wild-type strain. Our results indicate that the capability of ΔD39 to adhere to the PEC-A549 airway cells was significantly lower (p < 0.01) compared with D39. Additionally, the 100-KD choline-binding protein was not detected in ΔD39. The addition of competence-stimulating peptide (CSP) lead to a significantly reduction of psaA mRNA expression in the dprA-deficient mutant and an increased level of psaA transcripts in the wild-type strain (p < 0.01). The median survival time of mice intraperitoneally infected with ΔD39 was significantly higher (p < 0.01) than that of mice infected with D39. The results of this study suggest that DprA has a significant effect on virulence characteristics of S. pneumoniae by influencing the expression of choline-binding protein and PsaA.

OBJECTIVE: To examine and describe coronary heart disease (CHD) mortality and its pattern of change (trend) by sex, age, and area of residence (urban versus rural) in Tianjin, China, within the context of epidemiological transition, and compare it with current trends in the Americas and Europe. METHODS: A total of 104 393 cases of CHD death in Tianjin occurring between 1999 and 2008 were monitored. Death due to CHD was coded using International Classification of Diseases (ICD) standards (ninth and tenth revisions). Standardized CHD mortality rates and their trends were analyzed by age, sex, and urban versus rural residence. RESULTS: During the 10-year study period, the proportion of total deaths due to CHD in Tianjin increased significantly (from 16% to 24%) and age-standardized CHD mortality increased slightly (with no statistical differences), in contrast to CHD mortality trends in various countries in the Americas and Europe, which are declining. No difference was found in Tianjin's CHD mortality trend by sex. Overall CHD mortality was consistently higher among older age groups, males, and residents of urban areas. The proportion of CHD deaths occurring outside hospitals was 55.81%, with a declining trend over the study period. Rural areas had a higher proportion of outside-hospital CHD mortality than urban areas, but no difference was found across age groups. CONCLUSIONS: From 1999 to 2008, CHD mortality in Tianjin varied by sex, age, and urban versus rural area of residence. Future research to identify CHD risk factors and the populations most vulnerable to the disease is recommended to help strengthen CHD prevention. Strategies for CHD control similar to those used in various developed countries in the Americas and Europe should be developed to reduce the CHD burden in China.

OBJETIVO: Examinar y describir la mortalidad por cardiopatía coronaria y su patrón de cambio (tendencia) por sexo, edad y zona de residencia (urbana frente a rural) en Tianjín, China, en el contexto de la transición epidemiológica, y compararla con las tendencias actuales en las Américas y Europa. MÉTODOS: Se analizaron 104 393 casos de muertes debidas a cardiopatía coronaria ocurridas en Tianjín entre 1999 y 2008. Se codificó la mortalidad debida a cardiopatía coronaria según la Clasificación Internacional de Enfermedades (novena y décima revisiones). Se analizaron las tasas estandarizadas de mortalidad por cardiopatía coronaria y sus tendencias por edad, sexo y residencia urbana frente a rural. RESULTADOS: Durante el período de estudio, de 10 años, la proporción de la mortalidad total debida a cardiopatía coronaria registrada en Tianjín aumentó significativamente (de 16% a 24%) y la mortalidad por cardiopatía coronaria estandarizada por edad aumentó levemente (sin significación estadística), en contraposición con las tendencias de mortalidad por cardiopatía coronaria observadas en diversos países de las Américas y Europa, que están descendiendo. No se encontraron diferencias en la tendencia de la mortalidad por cardiopatía coronaria por sexo en Tianjín. La mortalidad general por cardiopatía coronaria fue sistemáticamente más elevada en los grupos de mayor edad, los varones y los residentes de zonas urbanas. La proporción de muertes debidas a cardiopatía coronaria que ocurrieron fuera de los hospitales fue de 55,81%, con una tendencia decreciente en el período de estudio. Esta proporción fue mayor en las zonas rurales que en las urbanas, pero no se encontró diferencia entre los distintos grupos de edad. CONCLUSIONES: Desde 1999 hasta el 2008, la mortalidad por cardiopatía coronaria en Tianjín varió según el sexo, la edad y la residencia urbana frente a la rural. Se recomienda efectuar nuevas investigaciones para identificar los factores de riesgo de cardiopatía coronaria y las poblaciones más vulnerables a la enfermedad, a fin de mejorar la prevención de la cardiopatía coronaria. Deben elaborarse estrategias para controlar la enfermedad similares a las usadas en varios países desarrollados de las Américas y Europa para reducir la carga de cardiopatía coronaria en China.