Enhanced optical absorption in two-dimensional Ruddlesden-Popper (C6H5CH2NH3)2PbI4 perovskites via biaxial strain and surface doping.

Two-dimensional Ruddlesden-Popper (2D RP) perovskites can form layered protective materials using long organic cations as "barrier" caps, which is expected to solve the problem of instability of perovskites in the working environment. In this work, we systematically studied the 2D Ruddlesden-Popper (C6H5CH2NH3)2PbI4 hybrid perovskites using density functional theory. The results reveal that the 2D (C6H5CH2NH3)2PbI4 perovskites are semiconductors with band gaps of 2.22 eV. The optical absorption peak of the 2D (C6H5CH2NH3)2PbI4 perovskite structure is located at 532 nm in the visible region. Interestingly, the optical absorption spectrum of the 2D (C6H5CH2NH3)2PbI4 perovskite structure enhanced under suitable strains. The highest optical absorption peak appears in 2D (C6H5CH2NH3)2PbI4 under a -2% strain, and its theoretical photoelectric conversion efficiency is 28.5%. More interestingly, the replacement of surface I atoms with Br is another ways to enhance the optical absorption spectrum of the 2D (C6H5CH2NH3)2PbI4 perovskite structure. The optical absorption peak blue-shifts to the high energy region, which has higher solar energy flux density than the low energy region. The good stability, tuneable band gap and excellent theoretical photoelectric conversion efficiency of the 2D (C6H5CH2NH3)2PbI4 perovskite structure make it a promising candidate for novel 2D hybrid perovskite based photoelectronic devices and solar cells.

Development and validation of an MRI-based radiomics nomogram for distinguishing Warthin's tumour from pleomorphic adenomas of the parotid gland.

OBJECTIVE：: Preoperative differentiation between parotid Warthin's tumor (WT) and pleomorphic adenoma (PMA) is crucial for treatment decisions. The purpose of this study was to establish and validate an MRI-based radiomics nomogram for preoperative differentiation between WT and PMA. METHODS AND MATERIALS: A total of 127 patients with histological diagnosis of WT or PMA from two clinical centres were enrolled in training set (n = 75; WT = 34, PMA = 41) and external test set (n = 52; WT = 24, PMA = 28). Radiomics features were extracted from axial T1WI and fs-T2WI images. A radiomics signature was constructed, and a radiomics score (Rad-score) was calculated. A clinical factors model was built using demographics and MRI findings. A radiomics nomogram combining the independent clinical factors and Rad-score was constructed. The receiver operating characteristic analysis was used to assess the performance levels of the nomogram, radiomics signature and clinical model. RESULTS: The radiomics nomogram incorporating the age and radiomics signature showed favourable predictive value for differentiating parotid WT from PMA, with AUCs of 0.953 and 0.918 for the training set and test set, respectively. CONCLUSIONS: The MRI-based radiomics nomogram had good performance in distinguishing parotid WT from PMA, which could optimize clinical decision-making.

[Estimation of Coal Consumption and the Emission of Related Contaminants in the Plain Area Around Beijing During 2015-2017].

Spatial distribution of bungalow areas in the plain area of Beijing was interpreted using high resolution remote sensing images from 2015-2017, and data for the nearby surrounding areas was added in 2017. The bungalow development areas were then refined by a combination of field sampling and imagery interpretation. A statistical model was developed to estimate the coal consumption in bungalow areas based on statistical records of the developed areas. Emissions associated with coal burning emissions, namely, particulate matter (PM2.5), sulfur dioxide (SO2), and nitrogen oxide (NOx), were estimated from emission factors collected from the relevant research. The results showed that residential coal burning decreased drastically by 75% during the period 2015-2017 in Beijing. The effect of coal modification (gas) measures is remarkable. Beijing's six downtown districts, and the urban and rural areas of the southern plain, have eliminated coal use at this stage. The districts in which coal burning is centered are located in the northern plains of Beijing. Coal consumption is greater than 300000 t in the Changping, Shunyi district, and greater than 150000 t in the Pinggu, Yanqing District. The spatial distribution of coal consumption in 2015 was focused in the city center, then became a circular and later a semi-circular distribution. Coal burning was centered in the districts of Changping, Shunyi, Tongzhou, and Daxing, which are all located on the ring perimeter. The emissions of SO2 and NOx in the plain areas of Beijing were obviously different. The highest emissions of SO2 and NOx were observed in the Changping district, and reached 1113.3 t and 279.2 t, respectively. The Coal Clean Energy Policy in Baoding, Langfang in 2017 has achieved initial success. However, the coal consumption is very large; the quality of the coal was poor and coal was used extensively. The coal burning intensity showed an increasing trend from north to south in Baoding and Langfang. The coal consumption in Baoding and Langfang totaled 1043×104 t and 407×104 t respectively. The villages in the suburbs of Baoding and Langfang used less coal, with a coal consumption of less than 5×104 t in Beishi, Nanshi, and Xinshi villages. The spatial distribution of coal consumption for the Langfang plain was relatively even and uniform. The highest coal consumption was found in Wen'an, with a value of 69×104 t, and the lowest was observed in Dachang.

[Analysis of a Pollution Process in the Beijing-Tianjin-Hebei Region Based on Satellite and Surface Observations].

The air pollution control of the Beijing-Tianjin-Hebei region (BTH region) is gradually moving toward regional joint mode. Remote sensing technology can be used to realize real-time dynamic monitoring over a wide range of space and ground-based monitoring can obtain accurate point information. Combining satellite with ground-based data, the formation and dissipation of pollution can be traced in three dimensions. For this paper, we analyzed the formation process, transmission path, coverage area, and the meteorological characteristics of the pollution process over the BTH region during March 8-10, 2018, using satellite remote sensing data, surface PM2.5 concentration data, meteorological data, and lidar data. The results showed that an area of 200000 km2 was affected by this pollution process and that the grade of the pollution reached the fourth level (moderate pollution level). The regional transmission process was very typical in this process. During 8-9 March, the occurrence frequency of the southward wind was about 50% in the Beijing-Baoding region and 100% over the southern part of Hebei. With the help of continuous southward wind, the air quality of the Beijing-Baoding area rises from the first level to the fourth level. The high value area of aerosol optical thickness moved from the western part of the Handan-Xingtai region to the front of Yanshan Mountain. On 10 March, the weak north wind affected the region and the humidity increased obviously. A pollution convergence formed in the southern part of the BTH region. The center of pollution moved southward to the east part of the Handan-Xingtai Region. In the afternoon, with the help of the eastern wind, the air quality of Beijing got better from East to West. The vertical lidar observation results showed the pollution layer above Beijing was mainly below 1000 m. There were two inversion layers below 800 m and 1200-1500 m, respectively. The inversion temperature was as high as 4-7℃, which is unfavorable for vertical diffusion of pollutants. Thus, under the high intensity of regional energy consumption and pollution emissions background, the regional heavy pollution form easily once the weather conditions are bad.

[Spatial and Temporal Distribution Characteristics and Fugitive Dust Emission of Building Sites in Beijing].

Because of the continuous expansion of the city and the evacuation of non-core functions, the city pattern of Beijing has gradually changed in recent years. Based on many construction projects, building sites are widely distributed within the city. Therefore, fugitive dust emission is an important factor affecting the air quality in Beijing. This article focuses on the plain area in Beijing. Remote sensing was used to extract building sites from 2013 to 2017, analyze the spatial and temporal distribution characteristics of the building sites, estimate the fugitive dust emission, and propose a grid-based emission classification management program. Research shows that the building sites form a belt surrounding the central urban area, mainly distributed in the urban-rural integration area. From 2013 to 2017, the area of the building sites first decreased and then increased. After 2015, the center of the building sites in Beijing shifted to the southeast and started to show an uneven distribution. The area of the building sites is positively correlated with the PM10 concentration. The correlation coefficients of 23 automatic ground monitoring stations are all above 0.80. Combined with the building site activity levels and emission factors, the estimated air pollutant emissions of TSP, PM10, and PM2.5 from building sites in 2017 were 39.5×104, 19.4×104, and 4.0×104 t, respectively. The emission intensity of the pollution in the grid has developed towards polarization, which further increased the emission intensity of high-strength pollution grids. Based on standardized PM10 grid emissions of building suites, the plain area of Beijing can be divided into five categories:lower pollution, low pollution, medium pollution, high pollution, and higher pollution.

A potential material for hydrogen storage: a Li decorated graphitic-CN monolayer.

Motivated by recent experimental developments of graphitic-CN (g-CN) sheets, we investigate the suitability of hydrogen storage on Li decorated g-CN via first-principles calculations. We find that the binding energies of Li atoms are very large, ranging from 2.70 to 4.73 eV, which are significantly higher than the cohesive energy of bulk Li. Lithium atoms therefore tend to form 2D rather than 3D patterns on g-CN, promoting reversible hydrogen adsorption and desorption. Remarkably, the average adsorption energy of H2 molecules falls in the 0.14-0.23 eV range, and the Li decorated CN shows a high theoretical gravimetric density of 10.81 wt%, which is favorable for massive hydrogen storage. Our results suggest that the Li decorated CN could be a promising hydrogen storage material under realistic conditions.

Cystatin C Shifts APP Processing from Amyloid-ß Production towards Non-Amyloidgenic Pathway in Brain Endothelial Cells.

Amyloid-ß (Aß), the major component of neuritic plaques in Alzheimer's disease (AD), is derived from sequential proteolytic cleavage of amyloid protein precursor (APP) by secretases. In this study, we found that cystatin C (CysC), a natural cysteine protease inhibitor, is able to reduce Aß40 secretion in human brain microvascular endothelial cells (HBMEC). The CysC-induced Aß40 reduction was caused by degradation of ß-secretase BACE1 through the ubiquitin/proteasome pathway. In contrast, we found that CysC promoted secretion of soluble APPα indicating the activated non-amyloidogenic processing of APP in HBMEC. Further results revealed that α-secretase ADAM10, which was transcriptionally upregulated in response to CysC, was required for the CysC-induced sAPPα secretion. Knockdown of SIRT1 abolished CysC-triggered ADAM10 upregulation and sAPPα production. Taken together, our results demonstrated that exogenously applied CysC can direct amyloidogenic APP processing to non-amyloidgenic pathway in brain endothelial cells, mediated by proteasomal degradation of BACE1 and SIRT1-mediated ADAM10 upregulation. Our study unveils previously unrecognized protective role of CysC in APP processing.

Two-dimensional interlocked pentagonal bilayer ice: how do water molecules form a hydrogen bonding network?

The plethora of ice structures observed both in bulk and under nanoscale confinement reflects the extraordinary ability of water molecules to form diverse forms of hydrogen bonding networks. An ideal hydrogen bonding network of water should satisfy three requirements: (1) four hydrogen bonds connected with every water molecule, (2) nearly linear hydrogen bonds, and (3) tetrahedral configuration for the four hydrogen bonds around an O atom. However, under nanoscale confinement, some of the three requirements have to be unmet, and the selection of the specific requirement(s) leads to different types of hydrogen bonding structures. According to molecular dynamics (MD) simulations for water confined between two smooth hydrophobic walls, we obtain a phase diagram of three two-dimensional (2D) crystalline structures and a bilayer liquid. A new 2D bilayer ice is found and named the interlocked pentagonal bilayer ice (IPBI), because its side view comprises interlocked pentagonal channels. The basic motif in the top view of IPBI is a large hexagon composed of four small pentagons, resembling the top view of a previously reported "coffin" bilayer ice [Johnston, et al., J. Chem. Phys., 2010, 133, 154516]. First-principles optimizations suggest that both bilayer ices are stable. However, there are fundamental differences between the two bilayer structures due to the difference in the selection among the three requirements. The IPBI sacrifices the linearity of hydrogen bonds to retain locally tetrahedral configurations of the hydrogen bonds, whereas the coffin structure does the opposite. The tradeoff between the conditions of an ideal hydrogen bonding network can serve as a generic guidance to understand the rich phase behaviors of nanoconfined water.

Association between IL-27 2905T/G genotypes and the risk and survival of cervical cancer: a case-control study.

BACKGROUND: Interleukin-27 (IL-27) has been recognized as a pleiotropic cytokine with both pro- and anti-inflammatory properties. PATIENTS AND METHODS: A case-control study was conducted to investigate the possible associations of IL-27 gene polymorphisms with susceptibility to cervical cancer and clinical outcome. RESULTS: Our results suggested that the IL-27 2905T/G was significantly associated with a decreased risk of cervical cancer. Further analysis showed IL-27 2905T/G genotypes were associated with advanced tumor stages of cervical cancer patients. More interestingly, the IL-27 2905T/G genotypes were statistically significantly associated with the survival in cervical cancer patients. CONCLUSION: Our results showed that the IL-27 2905T/G genotypes were associated with decreased the susceptibility and development of cervical cancer in Chinese Han population.

[Distribution Characteristics and Source Analysis of Dustfall Trace Elements During Winter in Beijing].

The dustfall content is one of the evaluation indexes of atmospheric pollution. Trace elements especially heavy metals in dustfall can lead to risks to ecological environment and human health. In order to study the distribution characteristics of trace elements, heavy metals pollution and their sources in winter atmospheric dust, 49 dustfall samples were collected in Beijing City and nearby during November 2013 to March 2014. Then the contents (mass percentages) of 40 trace elements were measured by Elan DRC It type inductively coupled plasma mass (ICP-MS). Test results showed that more than half of the trace elements in the dust were less than 10 mg x kg(-1); about a quarter were between 10-100 mg x kg-1); while 7 elements (Pb, Zr, Cr, Cu, Zn, Sr and Ba) were more than 100 mg x kg(-1). The contents of Pb, Cu, Zn, Bi, Cd and Mo of winter dustfall in Beijing city.were respectively 4.18, 4.66, 5.35, 6.31, 6.62, and 8.62 times as high as those of corresponding elements in the surface soil in the same period, which went beyond the soil background values by more than 300% . The contribution of human activities to dustfall trace heavy metals content in Beijing city was larger than that in the surrounding region. Then sources analysis of dustfall and its 20 main trace elements (Cd, Mo, Nb, Ga, Co, Y, Nd, Li, La, Ni, Rb, V, Ce, Pb, Zr, Cr, Cu, Zn, Sr, Ba) was conducted through a multi-method analysis, including Pearson correlation analysis, Kendall correlation coefficient analysis and principal component analysis. Research results indicated that sources of winter dustfall in Beijing city were mainly composed of the earth's crust sources (including road dust, construction dust and remote transmission of dust) and the burning of fossil fuels (vehicle emissions, coal combustion, biomass combustion and industrial processes).

Highly confined water: two-dimensional ice, amorphous ice, and clathrate hydrates.

Understanding phase behavior of highly confined water, ice, amorphous ice, and clathrate hydrates (or gas hydrates), not only enriches our view of phase transitions and structures of quasi-two-dimensional (Q2D) solids not seen in the bulk phases but also has important implications for diverse phenomena at the intersection between physical chemistry, cell biology, chemical engineering, and nanoscience. Relevant examples include, among others, boundary lubrication in nanofluidic and lab-on-a-chip devices, synthesis of antifreeze proteins for ice-growth inhibition, rapid cooling of biological suspensions or quenching emulsified water under high pressure, and storage of H2 and CO2 in gas hydrates. Classical molecular simulation (MD) is an indispensable tool to explore states and properties of highly confined water and ice. It also has the advantage of precisely monitoring the time and spatial domains in the sub-picosecond and sub-nanometer scales, which are difficult to control in laboratory experiments, and yet allows relatively long simulation at the 10(2) ns time scale that is impractical with ab initio molecular dynamics simulations. In this Account, we present an overview of our MD simulation studies of the structures and phase behaviors of highly confined water, ice, amorphous ice, and clathrate, in slit graphene nanopores. We survey six crystalline phases of monolayer (ML) ice revealed from MD simulations, including one low-density, one mid-density, and four high-density ML ices. We show additional supporting evidence on the structural stabilities of the four high-density ML ices in the vacuum (without the graphene confinement), for the first time, through quantum density-functional theory optimization of their free-standing structures at zero temperature. In addition, we summarize various low-density, high-density, and very-high-density Q2D bilayer (BL) ice and amorphous ice structures revealed from MD simulations. These simulations reinforce the notion that the nanoscale confinement not only can disrupt the hydrogen bonding network in bulk water but also can allow satisfaction of the ice rule for low-density and high-density Q2D crystalline structures. Highly confined water can serve as a generic model system for understanding a variety of Q2D materials science phenomena, for example, liquid-solid, solid-solid, solid-amorphous, and amorphous-amorphous transitions in real time, as well as the Ostwald staging during these transitions. Our simulations also bring new molecular insights into the formation of gas hydrate from a gas and water mixture at low temperature.

[Spatial distribution of inhalable particulate and association with respiratory disease in Beijing City].

Inhalable particulate has become the premier pollutant of Beijing, which has enormous influence on the environmental quality of the city and health of the residents. Inhalable particle pollutants (particulate matter of 0.3, 0.5, 3.0 and 5.0 microm) during the heating period and the non-heating period in 2008 and 2009 were collected, and spatial analysis was used to study the spatial distribution of each pollutant. Meanwhile, the hospital data about respiratory disease during the same time was gathered and counted. Then the relativity between inhalable particulate pollutants and respiratory disease was studied by grey correlation analysis on the base of regression analysis. The results showed that spatial distribution of fine particle was diverse but the pattern of coarse particle was similar. There was certain association between respiratory disease and inhalable particle pollutants. Heating period was the highest incidence period of respiratory disease. The prevalence of respiratory disease was higher in heating period than non-heating period. The concentration of fine particle was higher than that of coarse particle both in heating and non-heating periods, and fine particle had more effects on the respiratory system disease than coarse particle.

Chemiluminescence determination of gemifloxacin based on diperiodatoargentate (III)-sulphuric acid reaction in a micellar medium.

A novel flow-injection chemiluminescence (FI-CL) analysis method for the determination of gemifloxacin in the presence of cetyltrimethylammonium bromide (CTAB) surfactant micelles is described. Strong CL signal was generated during the reaction of gemifloxacin with diperiodatoargentate (III) in a sulfuric acid medium sensitized by CTAB. Under optimum experimental conditions, the CL intensity was linearly related to the concentration of gemifloxacin from 1.0 × 10(-9) to 3.0 × 10(-7) g/mL and the detection limit was 7.3 × 10(-10) g/mL (3σ). The relative standard deviation (RSD) was 1.7 % for a 3.0 × 10(-8) g/mL gemifloxacin solution (11 repeated measurements). The proposed method was successfully applied to the determination of gemifloxacin in pharmaceutical preparations and biological fluids. The possible mechanism of the CL reaction is also discussed briefly.

[Analysis of medication with hypertension by different glucose tolerance status].

OBJECTIVE: To analyze the combination of hypertension and the use of antihypertensive drugs by different glucose tolerance status. METHODS: Matched case-control design was used to sample the subjects from the population for the prevalence of diabetes mellitus and metabolism syndrome from 2007 to 2008. There were 3 groups including normal glucose tolerance (NGT, n = 2124), impaired glucose regulation (IGR, n = 2162) and diabetes (DM, n = 2470). The matched factors were location, age and gender. All subjects were interviewed to describe the hypertension and antihypertensive drugs of these conditions. RESULTS: After adjusting for age, gender and location, the combination of hypertension in IGR and DM groups was higher than NGT (28.3%, 40.2% and 19.9%) and OR was 1.29 (1.08 - 1.53) and 1.99 (1.67 - 2.37) respectively. The percent of treatment, prescription compliance and the surveillance of hypertension in total subjects were 48.6%, 79.3% and 62.5%. And no difference was observed among 3 groups. The proportion of calcium channel blocker of DM groups was higher than NGT group. The uses of angiotensin-converting enzyme inhibitors (ACEI) and angiotensin II receptor blocker (ARB) showed no difference among 3 groups. CONCLUSIONS: The combination of hypertension is higher in IGR and DM groups than that in NGT group. And the treatment rate of hypertension remains low. ACEI and ARB are under-utilized in IGR and DM groups.

Highly selective adsorption of methanol in carbon nanotubes immersed in methanol-water solution.

The systems of open-ended carbon nanotubes (CNTs) immersed in methanol-water solution are studied by molecular dynamics simulations. For the (6,6) CNT, nearly pure methanol is found to preferentially occupy interior space of the CNT. Even when the mass fraction (MF) of methanol in bulk solution is as low as 1%, the methanol MF within the CNT is still more than 90%. For CNTs with larger diameters, the methanol concentrations within CNTs are also much higher than those outside CNTs. The methanol selectivity decreases with increasing CNT diameter, but not monotonically. From microscopic structural analyses, we find that the primary reason for the high selectivity of methanol by CNTs lies on high preference of methanol in the first solvation shell near the inner wall of CNT, which stems from a synergy effect of the van der Waals interaction between CNT and the methyl groups of methanol, together with the hydrogen bonding interaction among the liquid molecules. This synergy effect may be of general significance and extended to other systems, such as ethanol aqueous solution and methanol/ethanol mixture. The selective adsorption of methanol over water in CNTs may find applications in separation of water and methanol, detection of methanol, and preservation of methanol purity in fuel cells.

[Correlates of cognitive impairment in patients with leukoaraiosis by magnetic resonance spectroscopy].

OBJECTIVE: To explore the pathological changes in patients with leukoaraiosis (LA) by magnetic resonance spectroscopy (MRS) and examine its relationship with cognitive function. METHODS: Twenty-three LA patients and 23 age and gender-matched healthy subjects were recruited from the Department of Neurology, Beijing Chaoyang Hospital, Capital Medical University between August 2010 and November 2010. All participants underwent the neuropsychological tests. Multi-voxel chemical shift imaging was performed and the regions of interest were positioned in bilateral frontal white matter. The relative metabolite ratios, involving N-acetyl aspartate/choline ratio (NAA/Cho), N-acetyl aspartate/creatine (NAA/Cr) and choline/creatine (Cho/Cr), were estimated. The correlation of the MRS data and the performance of cognitive function was analyzed. RESULTS: The LA patients were associated with a worse performance of mini mental state examination (MMSE) versus the healthy controls (24 ± 3 vs 28 ± 1, P < 0.05). Univariate analysis of the MRS data revealed the ratios of NAA/Cho and NAA/Cr significantly decreased in bilateral frontal white matter lesions in the LA group versus the control group (1.72 ± 0.20 vs 1.96 ± 0.36, 1.67 ± 0.17 vs 1.85 ± 0.21, P < 0.05). The values of NAA/Cr and NAA/Cho in normal appearing white matter increased versus the LA group (1.83 ± 0.24 vs 1.72 ± 0.20, 1.78 ± 0.28 vs 1.67 ± 0.17) and decreased versus the control group (1.83 ± 0.24 vs 1.96 ± 0.36, 1.78 ± 0.28 vs 1.85 ± 0.21). But no significant differences were found (P > 0.05). The ratio of Cho/Cr did not differ among 3 groups (P > 0.05). The pathological change of NAA/Cr in white matter lesion in LA patients was markedly correlated with the performance of MMSE (r = 0.47, P < 0.05). CONCLUSION: NAA may be a marker of axonal loss/dysfunction in LA patients. And the changes of NAA/Cr have a positive correlation with cognitive impairment.

[Serum uric acid level and related clinical features in neuromyelitis optica].

OBJECTIVE: To investigate serum uric acid (UA) levels and related clinical characteristics of neuromyelitis optica (NMO). METHODS: The serum uric acid levels were measured in 65 patients with NMO, compared to control groups which were 76 cases with multiple sclerosis (MS), 126 cases with cerebral vascular diseases (CVD) and 130 healthy controls (HC). The disability severity in NMO was assessed by the Expanded Disability Status Scale (EDSS). Magnetic resonance imaging (MRI) was performed to strengthen assessment the involved lesions. Serum AQP4 antibody was tested in a cell based immunofluorescence assay. RESULTS: In male groups, serum UA levels in NMO patients [(298.90 ± 74.14) µmol/L] were significantly lower than that in CVD [(355.37 ± 50.30) µmol/L] and HC subjects [(340.33 ± 58.23) µmol/L, P < 0.05]. No difference was found between NMO and MS [(292.36 ± 92.95) µmol/L] groups. In female groups, serum UA levels in NMO patients [(198.21 ± 62.62) µmol/L] were significantly lower than that in CVD [(274.51 ± 70.66) µmol/L] and HC subjects [(243.26 ± 60.65) µmol/L, P < 0.05]. No difference was found between NMO and MS [(232.29 ± 71.95) µmol/L] groups. UA levels were significantly lower in females [(198.21 ± 62.62) µmol/L] than in males [(298.90 ± 74.14) µmol/L]. UA levels were significantly lower in patients with EDSS ≥ 5 [(195.48 ± 83.70) µmol/L] than EDSS < 5 [(241.00 ± 63.20) µmol/L] NMO patients. In our study UA levels were not correlated with longitude of spinal lesions, activity revealed by MRI and AQP4 antibody tires. CONCLUSION: Lower serum UA levels were found in patients with NMO and related to more severe symptoms.

[Relationship between hepatic insulin resistance and the expression of genes involved in hepatic glucose output].

OBJECTIVE: To study the relationship between hepatic insulin resistance induced by high fat diet and the expression of genes involving hepatic glucose output. METHODS: Normal 8-week-old male SD rats were randomly divided into two groups, i.e, normal chow group (NC, n = 10) and high fat diet group (HF, n = 10). They were fed for 28 weeks. Body weight and fasting blood glucose (FBG) were measured. At the end of the experiment, the rats were sacrificed and their fasting insulin (INS) and triglycerides (TG) were measured. Hepatic insulin sensitivity was measured by tissue uptake of 3H-2-deoxyglucose and the content of hepatic glycogen was measured using the anthrone method. Gene expression was investigated by using the semi-quantitative RT-PCR method. RESULTS: As compared with NC group, CF group rats developed visceral obesity which was accompanied by higher plasma TG. FBG in CF group increased starting from the 18th week (NC 4.77+/-63 mmol/L vs HF 5.45+/-87 mmol/L, P < 0.05). The rate of uptake of 3H-2-deoxyglucose in livers decreased by 51% in the HF group. The content of hepatic glycogen increased by 92.4% (P < 0.01). The level of phosphoenolpyruvate carboxykinase (PEPCK) and PGC-1a mRNA increased by 41.5% and 30.8%, respectively (P < 0.05). CONCLUSION: A high fat diet induced expressions of PGC-1a and PEPCK. It suggests that gluconeogenesis may play a role in the increase of hepatic glucose output and FBG.

[Relation between c-erbB1, c-erbB2, MAPK expression and resistance to tamoxifen in breast cancer cells in vitro].

OBJECTIVE: To study the growth regulation pathway and the mechanism of acquired resistance to tamoxifen (TAM) in breast cancer cells. METHODS: TAM was used to induce wild-type MCF-7 human breast cancer cell line and establish a tamoxifen-resistant (TAM-R) cell line. RT-PCR, Western blot and immuocytochemical techniques were used to detect and compare mRNA and protein of c-erbB1, cerbB2, c-erbB3, c-erbB4 in wild-type MCF-7 and TAM-R MCF-7 cell lines. RESULTS: Compared with wild-type MCF-7 cells, the mRNA of c-erbB1 increased 6 times (P < 0.05) and the protein 3 times higher (P < 0.05), and the mRNA of c-erbB2 increased 3 times (P < 0.05) and the protein 1.5 times higher (P < 0.05) in TAM-R MCF-7 cells. However, comparable levels of c-erbB3 mRNA and protein were expressed in both cell lines. c-erbB4 could not be detected. Under basic conditions, phosphorylated c-erbB1/c-erbB2 and c-erbB1/c-erbB3 heterodimers but not c-erbB2/c-erbB3 receptor heterodimers were detected in TAM-R cells in association with increased level of phosphorylated MAPK. CONCLUSION: Our findings demonstrated that the development of TAM-resistance in MCF-7 cells is related with the autocrine release and action of an c-erbB1-specific ligand inducing preferential c-erbB1/c-erbB2 dimerization and downstream activation of the MAPK pathway.

[Relationship between adipose phosphoenolpyruvate carboxykinase and occurrence and reversion of insulin resistance].

OBJECTIVE: To investigate the relationship between the expression of phosphoenolpyruvate carboxykinase (PEPCK) gene and insulin resistance induced by high-fat diet and the effect of rosiglitazone, a thiazolidinedione drug. METHODS: Sixty-three normal 8-week-old male SD rats were randomly divided into 2 groups: short-term group, n = 33, to be fed for 8 weeks and re-divide into 3 equal subgroups: standard chow diet subgroup (NC subgroup fed with standard chow diet), high-fat diet subgroup (HF subgroup, to be fed with lard), and high-fat diet with rosiglitazone subgroup (HF + rosiglitazone subgroup); and long-term group, n = 30, to be fed for 28 weeks, and re-divided into 3 corresponding 3 subgroups: By the end of experiment, serum samples were collected to examine the blood glucose (BG), triglyceride (TG) and free fatty acid (FFA). At the end of the experiment the rats were killed and the visceral adipose tissue was taken out to be weighed, and the liver, muscle, and epididymis were isolated. Glucose infusion rate (GIR) methods and tissue uptake of (3)H-2-deoxyglucose were used to short-and long-term groups evaluate the insulin sensitivity. PEPCK gene expression was investigated to detect the expression of PEPCK mRNA by using semi-quantitative RT-PCR method. RESULTS: In the short-term group, the serum FFA and TG of the HF + rosiglitazone subgroup were lower by 24.5% and 54.0% respectively compared with those the HF subgroup (both P < 0.01). In the long-term group, the serum TG of the HF subgroup was higher by 32.4% in comparison with that of the NC subgroup (P < 0.05), and the serum FFA and TG of the HF + rosiglitazone subgroup were lower by 49.5% and 23.0% respectively compared with those of the HF subgroup (both P < 0.0). In the short-term group the GIR of the HF subgroup was lower by 51.25% in comparison with that of the NC subgroup (P < 0.01). And the GIR of the HF + rosiglitazone subgroup was higher by 149.6% than that of the HF group (P < 0.01). In the long-term group, the rate of uptake of (3)H-2-deoxyglucose in liver, muscle and adipose tissue of the HF subgroup were lower by 42.0%, 36.7%, and 48.1% respectively than those of the HF subgroup (all P < 0.01), and the rate of uptake of 3H-2-deoxyglucose in liver, muscle and adipose tissue of the HF + rosiglitazone subgroup were higher by 39.6%, 66.3%, and 66.7% respectively than those of the HF subgroup (all P < 0.01). In the short-term group the adipose PEPCK mRNA expression of the HF subgroup was 89% +/- 13% that of the NC subgroup; and the adipose PEPCK mRNA expression of the HF + rosiglitazone subgroup was 154% +/- 28% that of the NC subgroup, and was higher by 65.4% than that the HF subgroup (P < 0.05). In the long-term group, the adipose PEPCK mRNA expression of the HF + rosiglitazone subgroup was 144% +/- 17% that of the NC subgroup (P < 0.05), and was higher by 43.3% than that of the HF subgroup (P < 0.05). CONCLUSION: Thiazolidinedione drug increases the re-esterification of fatty acids and reduces circulating FFA, and induces the expression of adipose PEPCK which is accompanied by reduction of FFA, thus improving insulin resistance.