Nanoengineered Design of inside-Heating Hot Nanoreactor Surrounded by Cool Environment for Selective Hydrogenations.

Catalysts with designable intelligent nanostructure may potentially drive the changes in chemical reaction techniques. Herein, a multi-function integrating nanocatalyst, Pt-containing magnetic yolk-shell carbonaceous structure, having catalysis function, microenvironment heating, thermal insulation, and elevated pressure into a whole is designed, which induces selective hydrogenation within heating-constrained nanoreactors surrounded by ambient environment. As a demonstration, carbonyl of α, ß-unsaturated aldehydes/ketones are selectively hydrogenated to unsaturated alcohols with a >98% selectivity at a nearly complete conversion under mild conditions of 40 °C and 3 bar instead of harsh requirements of 120 °C and 30 bar. It is creatively demonstrated that the locally increased temperature and endogenous pressure (estimated as ≈120 °C, 9.7 bar) in the nano-sized space greatly facilitate the reaction kinetics under an alternating magnetic field. The outward-diffused products to the "cool environment" remain thermodynamically stable, avoiding the over-hydrogenation that often occurs under constantly heated conditions of 120 °C. Regulation of the electronic state of Pt by sulfur doping of carbon allows selective chemical adsorption of the CO group and consequently leads to selective hydrogenation. It is expected that such a multi-function integrated catalyst provides an ideal platform for precisely operating a variety of organic liquid-phase transformations under mild reaction conditions.

New bio-based polyester with excellent spinning performance: poly(tetrahydrofuran dimethanol-co-ethylene terephthalate).

With the excessive consumption of fossil energy, technologies that transform bio-based resources into materials have received more and more attention from researchers in recent decades. In this paper, a series of poly(ethylene 2,5-tetrahydrofuran dimethyl terephthalate; PEFTs) with different components were synthesized from 2,5-tetrahydrofuran dimethanol (THFDM), terephthalic acid (TPA), and ethylene glycol (EG). Their chemical structures and compositions were determined by FTIR, 1H NMR, and 13C NMR. With the increase in THFDM content, the crystallization, T m, and tensile strength of PEFTs gradually decrease because the introduced THFDM breaks the order of molecular chains, while the thermal stability and T g remain stable. PEFTs seem to present a significant shear thinning phenomenon, which was indicated by the rheological test. Electrospinning technology was used to explore the spinnability of PEFT; it was found that PEFTs have better spinning performance than PET. In addition, due to the good hydrophobicity and porosity of PEFT nanofiber films, they have potential application value in the manufacture of hydrophobic nanofiber and filter films.

Selective Synthesis of Carbon Nanorings via Asymmetric Intramicellar Phase-Transition-Induced Tip-to-Tip Assembly.

The selective synthesis of energetically less favorable ring-shaped nanostructures by liquid phase synthetic chemistry is a huge challenge. Herein, we report a precise synthesis of carbon nanorings with a well-defined morphology and tunable thickness based on asymmetric intramicellar phase-transition-induced tip-to-tip assembly via mixing hydrophobic long-chain octadecanol and block copolymer F127. This orientational self-assembly depends on the hydrophobicity difference of the intermediate's surface, which triggers directional interactions that surpass the entropy cost of undesired connections and help assemble intermediates into defined ringlike structures. Based on a ringlike template, carbon nanorings with adjustable sizes can be attained by changing synthetic variables. More importantly, diverse units including crescentlike, podlike, and garlandlike nanostructures can also be created through controlling the kinetics of the self-assembly process. This discovery lays a solid foundation for the challenging construction of such a precise configuration on the nanoscale, which would not only promote fundamental studies but also pave the way for the development of advanced nanodevices with unique properties.

Sea-level rise will reduce net CO2 uptake in subtropical coastal marshes.

Coastal marshes have a significant capacity to sequester carbon; however, sea-level rise (SLR) is expected to result in prolonged flooding and saltwater intrusion in coastal regions. To explore the effects of SLR projections on net CO2 uptake in coastal marshes, we conducted a "double-check" investigation, including the eddy covariance (EC) measurements of the CO2 fluxes in subtropical coastal marshes along inundation and salinity gradients, in combination with a mesocosm experiment for analyzing CO2 flux components under waterlogging and increased salinity conditions. During the same measurement periods, the net ecosystem CO2 exchange (NEEEC based on the EC dataset) in an oligohaline marsh was higher than that in a low-elevation mesohaline marsh, whereas the NEEEC was lower than that in a high-elevation freshwater marsh. The declines in NEEEC between the marshes could be attributed to a greater decrease in gross primary production relative to ecosystem respiration. Waterlogging slightly increased the NEEms (NEE based on the mesocosms) because of inhibited soil respiration and slight changes in plant photosynthesis and shoot respiration. However, the NEEms measured during the drainage period decreased significantly due to the stimulated soil respiration. The NEEms decreased with increasing salinity (except under mild salinity), and waterlogging exacerbated the adverse impacts of salinity. The amplificatory effect of decreases in both leaf photosynthesis and growth under hydrological stresses contributed more to reduce the NEEms than to respiratory effluxes. Both waterlogging and increased salinity reduced the root biomass, soil microbial biomass, and activities of assayed soil enzymes (except for cellulase under waterlogging conditions), leading to limited soil respiration. The declines in plant growth, photosynthesis, and soil respiration could also be attributed to the decrease in soil nutrients under waterlogging and increased salinity conditions. We propose that the coupling of SLR-driven hydrological effects lowers the capacity of CO2 uptake in subtropical coastal marshes.

Ab-Initio Study of the Electronic and Magnetic Properties of Boron- and Nitrogen-Doped Penta-Graphene.

First-principles calculations were performed to investigate the effects of boron/nitrogen dopant on the geometry, electronic structure and magnetic properties of the penta-graphene system. It was found that the electronic band gap of penta-graphene could be tuned and varied between 1.88 and 2.12 eV depending on the type and location of the substitution. Moreover, the introduction of dopant could cause spin polarization and lead to the emergence of local magnetic moments. The main origin of the magnetic moment was analyzed and discussed by the examination of the spin-polarized charge density. Furthermore, the direction of charge transfer between the dopant and host atoms could be attributed to the competition between the charge polarization and the atomic electronegativity. Two charge-transfer mechanisms worked together to determine which atoms obtained electrons. These results provide the possibility of modifying penta-graphene by doping, making it suitable for future applications in the field of optoelectronic and magnetic devices.

[Simulation of Inorganic Nitrogen Fluxes at the Sediment-water Interface in a Typical Intertidal Zone, Eastern China].

Taking 12 typical intertidal zones along the eastern coast of China as the research object, indoor tide simulation experiments were conducted to measure exchange fluxes of nitrate nitrogen (NO3--N) and ammonia nitrogen (NH4+-N) between overlying water and sediments, to investigate their spatial distribution, and to clarify controlling factors such as salinity, temperature, and organic matter. Results showed that the total NO3--N flux was -2.91-3.34 mmol·(m2·h)-1, while the total flux of NH4+-N was -4.36-2.34 mmol·(m2·h)-1. The average flux, at 12℃ and 35℃, was -0.04 mmol·(m2·h)-1, indicating that typical intertidal zone sediment is an effective sink for ammonia nitrogen and nitrate nitrogen. There was a significant difference in the spatial distribution of nitrate and ammonia nitrogen fluxes. At 12℃, the higher the latitude, the greater the ammonia nitrogen flux; results for the 25°-35°N intertidal nitrate flux were as follows:<15°-25°N < 35°-45°N at 25℃ and 35℃, while the flux of ammonia nitrogen was 25°N-35°N > 15°-25°N > 35°-45°N. The fluxes of the three intertidal zones decreased with increase in temperature, which controls the coupled nitrification-denitrification taking place in the upper layer of sediment and at the bottom of overlying water. NO3--N fluxes first increased and then decreased with temperature at 15°-25°N and 35°-45°N, while NO3--N fluxes at 25°-35°N always decreased with temperature. At each latitude, the higher the temperature, the lower the NH4+-N flux. There was no single significant effect of environmental factors on fluxes. Salinity, sediment organic carbon (OC), sediment total nitrogen (TN), concentrations of ammonia nitrogen and nitrate nitrogen in pore water, and bulk density synergistically affected the spatial differentiation of exchanged NO3--N and NH4+-N fluxes.

Ecophysiological response of native and exotic salt marsh vegetation to waterlogging and salinity: Implications for the effects of sea-level rise.

The ecophysiological characteristics of native Phragmites australis and exotic Spartina alterniflora grown under waterlogging and salinity were investigated to explore their adaptation potential to sea level rise. The seasonal course of phenotypic traits, photosynthetic activity and chlorophyll fluorescence parameters of P. australis did not change remarkably under shallow flooding, whereas these variables were sensitive to increasing salinity. Waterlogging exacerbated the negative effects of salinity on shoot growth and photosynthetic activity of P. australis, and the combined stresses led to an absence of tassel and reproductive organs. By contrast, S. alterniflora performed well under both stresses and showed an obvious adaptation of salt secretion with increasing salinity. Light salinity was the optimal condition for S. alterniflora, and the tassel growth, chlorophyll content and fluorescence characters under moderate stresses did not differ notably. The Na+ and Cl- concentrations in leaves of both species increased, and the K+ content decreased in response to salinity. Under moderate and high saline levels, the ion concentrations in S. alterniflora were maintained at relatively consistent levels with increased salt secretion. We expect the degradation of P. australis and further colonization of S. alterniflora under prolonged flooding and saltwater intrusion from sea level rise on the coastline of China.

Evaluation of Safety and Efficacy of Qinming8631 DR Implantable Cardiac Pacemaker in Chinese Patients: A Prospective, Multicenter, Randomized Controlled Trial of the First Domestically Developed Pacemaker of China.

BACKGROUND: High cost of imported pacemakers is a main obstacle for Chinese patients suffering from bradyarrhythmia, and a domestically developed pacemaker will help lower the burden. This study aimed to evaluate the safety and efficacy of Qinming8631 DR (Qinming Medical, Baoji, China), the first domestically developed dual-chamber pacemaker of China, compared with a commercially available pacemaker Talos DR (Biotronik, Berlin, Germany) in Chinese patients. METHODS: A prospective randomized trial was conducted at 14 centers in China. Participants were randomized into trial (Qinming8631 DR) and control (Talos DR) groups. Parameters of the pacing systems were collected immediately after device implantation and during follow-ups. The effective pacing rate at 6-month follow-up was recorded as the primary end point. Electrical properties, magnet response, single- and double-pole polarity conversion, rate response function, and adverse events of the pacing system were analyzed. The Cochran-Mantel-Haenszel Chi-square test, paired t-test, and Wilcoxon signed-rank test were used for measuring primary qualitative outcomes and comparing normally and abnormally distributed measurement data. RESULTS: A total of 225 patients with a diagnosis of bradyarrhythmia and eligible for this study were randomly enrolled into the trial (n = 113) and control (n = 112) groups. They underwent successful pacemaker implantation with acceptable postoperative pacing threshold and sensitivity. Effective pacing rates of trial and control groups were comparable both in the full analysis set and the per protocol set (81.4% vs. 79.5%, P = 0.712 and 95.4% vs. 89.5%, P = 0.143, respectively). In both data sets, noninferiority of the trial group was above the predefined noninferiority limit(-9.5%). CONCLUSIONS: This study established the noninferiority of Qinming8631 DR to Talos DR. The safety and efficacy of Qinming8631 DR pacemaker were comparable to those of Talos DR in treating patients with cardiac bradyarrhythmia.

Role of Kir2.1 in human monocyte-derived foam cell maturation.

The role of K(+) channels in macrophage immunomodulation has been well-established. However, it remains unclear whether K(+) channels are involved in the lipid uptake of macrophages. The expression and function of the inward rectifier potassium channel (Kir2.1, KCNJ2) in Human acute monocytic leukemia cell line (THP-1) cells and human monocytes derived macrophages (HMDMs) were investigated using RT-PCR and western blotting, and patch clamp technique. The expression of scavenger receptors in THP-1-derived macrophages was detected using western blotting. Expressions of Kir2.1 mRNA and protein in HMDMs were significantly decreased by 60% (P < 0.05) and 90% (P < 0.001) on macrophage maturation, but overexpressed by approximately 1.3 (P > 0.05) and 3.8 times (P = 0.001) after foam cell formation respectively. Concurrently, the Kir2.1 peak current density in HMDMs, mature macrophages and foam cells, measured at -150 mV, were -22.61 ± 2.1 pA/pF, -7.88 ± 0.60 pA/pF and -13.39 ± 0.80 pA/pF respectively (P < 0.05). In association with an up-regulation of Kir2.1 in foam cells, the SR-A protein level was significantly increased by over 1.5 times compared with macrophages (P < 0.05). THP-1 cells contained much less lipids upon Kir2.1 knockdown and cholesterol ester/total cholesterol ratio was 29.46 ± 2.01% (P < 0.05), and the SR-BI protein level was increased by over 6.2 times, compared to that of macrophages (P < 0.001). Kir2.1 may participate in macrophage maturation and differentiation, and play a key role in lipid uptake and foam cell formation through modulating the expression of scavenger receptors.

Car-Parrinello molecular dynamics/molecular mechanics (CPMD/MM) simulation study of coupling and uncoupling mechanisms of Cytochrome P450cam.

The relevance of the pathway through which the second proton is delivered to the active site of P450cam and the subsequent coupling/uncoupling reactions has been investigated using Car-Parrinello molecular dynamics/molecular mechanics (CPMD/MM) dynamics simulations. Five models have been prepared, representing delivery pathways in the wild-type enzyme and its mutants in which Thr252 mutated into other residues with different side-chain length and hydrophobicity. In the simulations, coupling reaction is observed in the wild-type enzyme (Model A) and its T252S mutant (Model B), while the uncoupling products are obtained in the other three models (C, D, and E). Different from previous studies, a dynamic process of the last stage of coupling/uncoupling was observed. We found that the peroxide bond cleavage in coupling, the Fe-O bond stretching in uncoupling, proton transfer, and electron delivery take place spontaneously. Moreover, besides the intrinsic chemical differences between the two peroxide oxygen atoms, water molecules in the active site and the proton transfer pathway may play an important role in the determination of coupling/uncoupling. We conclude that by maintaining a specific proton transfer channel, Asp251-Thr252 channel, the wild-type enzyme could efficiently deliver the second proton to the ideal position for coupling reaction.

[Calcium carbonate precipitation in UASB reactors with different substrates].

Two lab scale upflow anaerobic sludge bed (UASB) reactors were operated at an organic loading rate of COD 9 kg x (m3 x d)(-1) to treat two kinds of calcium containing wastewaters, one of which took acetic acid as substrate and for the other, glucose and soluble starch were the substrate. Both the wastewaters contained 800 mg x L(-1) Ca+. Precipitation of calcium carbonate in the reactors was observed. The results showed that the kind of substrate had great influence on calcium carbonate precipitation. In the reactor treating acetic acid containing wastewater, a maximum calcium precipitation rate of 65% was achieved and an average rate of about 25% was then maintained. In contrast, the calcium precipitation rate for the glucose and soluble starch containing wastewater was only about 7.5%. It was also found that substantial precipitation only occurred 30 days after the reactor were operated for both of the wastewaters. After 180 days of operation, the ash content of the sludge in the reactors increased from about 10% to 70% for the acetic acid containing wastewater and 30% for the other. However, the increase of ash content had no negative influence on the COD removal efficiency, which was kept at about 90% throughout the experimental period. By the SEM it was inferred that the different substrates caused the differences of the granular sludge microstructure, leading to the diversity of calcium carbonate precipitation in the two reactors.

HERG-F463L potassium channels linked to long QT syndrome reduce I(Kr) current by a trafficking-deficient mechanism.

1. Congenital long QT syndrome (LQTS) is a genetically heterogeneous disease. The aim of the present study was to identify the gene mutation in a Chinese family with LQTS and investigate the functional changes associated with the mutation. 2. Polymerase chain reaction and DNA sequencing were used to screen for the KCNH2 mutation in the proband. A mutant F463L HERG channel was expressed in HEK293 cells using a lipofectamine method. The IKr current was recorded using the whole-cell voltage clamp technique. Expression of HERG protein was detected by western blotting and the subcellular location of HERG channels in cell was analysed by confocal microscopy. 3. The novel heterozygous missense mutation F463L in KCNH2 was detected. We found that the F463L mutation did not lead to any expression of detectable I(Kr) current, which was consistent with western blotting analysis indicating that the F463L mutation only expressed a band at 135 kDa. When coexpressed with wild-type HERG, F463L HERG exhibited strong dominant-negative current suppression, resulting in a decrease in I(Kr) current density, and induced a positive shift in the voltage dependence of activation, as well as interference with trafficking of wild-type channel protein. The processing of the F463L channels was partly corrected in cells incubated in E4031. In addition, confocal microscopy demonstrated that F463L subunits could be inserted into the cell membrane when forming heteromultimeric channels with wild-type channel subunits. 4. The results of the present study suggest that the F463L mutation leads to loss of function in HERG through a dominant-negative effect caused by impaired trafficking of the channel.

[Geographical characteristics of single nucleotide polymorphism of candidate genes associated with coronary artery disease in Chinese Han population].

OBJECTIVE: To investigate the geographical characteristics of single nucleotide polymorphism (SNP) of candidate genes associated with coronary artery disease in Chinese Han population. METHODS: Study population were Chinese Han nationality recruited from Xi'an, Shiyan and Ningbo districts. Patients with coronary artery disease were defined by coronary angiography with stenosis >or= 50% and control subjects with stenosis < 10%, respectively. The DNA was extracted from peripheral white blood cell by approach comprised proteinase K digestion, phenol and chloroform extraction as well as isopropanol precipitation. The SNP of ATP-binding cassette transporter (ABCA1)-G596A, cholesteryl ester transfer protein (CETP)-Taq1B, Lipoprotein lipase (LPL)-Hind III and LPL-Pvu II were genotyped by PCR-RFLPs, and verified by gene sequencing. RESULTS: A Total of 615 patients undertaken coronary angiography were recruited from cardiac center in Xi'an (220), Ningbo (209) and Shiyan district (186), China (mean age 60 +/- 10 years, 75.9% males). Diabetes mellitus was more prevalent in Xi'an Cohort population than Shiyan and Ningbo cohort (P < 0.01). Plasma total cholesterol, LDL cholesterol and triglyceride levels in Xi'an Cohort population were significantly higher, and HDL-C siginificantly lower than in Shiyan and Ningbo cohort population [HDL-C: (1.17 +/- 0.48) mmol/L vs. (1.25 +/- 0.33) mmol/L and (1.29 +/- 0.44) mmol/L, P < 0.05]. Distribution differences for ABCA1-G596A and CETP-Taq1B genotypes were found in Xi'an Cohort population compared to Ningbo and Shiyan cohorts (for ABCA1, Xi'an: 0.24, 0.53, 0.23 and Shiyan: 0.17, 0.62, 0.21 and Ningbo: 0.34, 0.37, 0.29, for GG, AG, AA, respectively, P < 0.01; and for CETP, Xi'an: 0.29, 0.54, 0.17 and Shiyan: 0.38, 0.40, 0.22 and Ningbo: 0.39, 0.49, 0.12 for B1B1, B1B2, B2B2, respectively, P < 0.01), but not for LPL variants. ABCA1-G596A variant predicted HDL-C [Xi'an: (1.2 +/- 0.3) mmol/L, (1.3 +/- 0.2) mmol/L and (1.4 +/- 0.4) mmol/L, P = 0.01; Shiyan: (1.1 +/- 0.4) mmol/L: (1.2 +/- 0.3) mmol/L and (1.3 +/- 0.4) mmol/L, P = 0.03; Ningbo, (1.2 +/- 0.3) mmol/L, (1.3 +/- 0.4) mmol/L and (1.4 +/- 0.3) mmol/L, across GG, GA to AA genotype, respectively, P = 0.01] and TG levels [Xi'an: (2.4 +/- 1.3) mmol/L, (1.9 +/- 0.9) mmol/L and (1.6 +/- 0.8) mmol/L, P < 0.01; Shiyan: (2.1 +/- 1.0) mmol/L, (1.9 +/- 0.8) mmol/L and (1.8 +/- 0.7) mmol/L, P = 0.03; Ningbo: (1.9 +/- 1.1) mmol/L, (1.8 +/- 0.9) mmol/L and (1.6 +/- 0.7) mmol/L, across GG, GA to AA genotype, P = 0.05] with dose-dependent relationship. LPL-Hind III (+) carriers had higher triglycerides in three cohort population [Xi'an: (2.2 +/- 1.0) mmol/L, (1.8 +/- 0.9) mmol/L, (1.6 +/- 0.7) mmol/L, P = 0.01; Shiyan: (2.1 +/- 0.7) mmol/L, (1.9 +/- 1.0) mmol/L, (1.7 +/- 0.6) mmol/L, P = 0.01; Ningbo: (1.8 +/- 1.0) mmol/L, (1.6 +/- 0.6) mmol/L and (1.4 +/- 0.5) mmol/L, for +/+, +/- and -/- genotypes, respectively, P = 0.001]. SNP of CETP-Taq1B, LPL-Hind III and LPL-Pvu II predicted HDL-C and/or TG levels in different cohort population with different manners. All these SNP were not significantly associated with the development of coronary artery disease (all P > 0.05). CONCLUSION: A geographical heterogeneity of environmental and genetic risk factors related to the development of coronary artery disease exists in Chinese Han population. Irrespective of the different geographical cohort of Chinese Han population, the SNP of candidate genes can partly predict the differences in risk-related plasma HDL-C and/or TG levels rather than angiographic coronary artery disease.

[Heavy metals in environmental media around drinking water conservation area of Shanghai].

The levels of heavy metals in Shanghai drinking water conservation area were determined, and the spatial distributions and main sources of heavy metals were investigated. Moreover, the ecological risk assessment of heavy metals was conducted. Some conclusions can be drawn as follows: (1) The average concentrations of Cd, Hg, Pb, Cu, Zn, Ni, Cr and As in road dust were 0.80, 0.23, 148.45, 127.52, 380.57, 63.17, 250.38 and 10.37 mg x kg(-1) respectively. In terms of the pollution level, the values of soils were relatively lower, with the mean contents of 0.16 (Cd), 0.33 (Hg), 30.14 (Pb), 30.66 (Cu), 103.79 (Zn), 24.04 (Ni), 65.75 (Cr) and 6.31 mg x kg(-1) (As) severally; meanwhile the average levels of heavy metals in vegetables were 0.010 (Cd), 0.016 (Hg), 0.36 (Pb), 12.80 (Cu), 61.69 (Zn), 2.04 (Ni), 2.41 (Cr) and 0.039 mg x kg(-1) (As) respectively. (2) Semivariogram and multivariate analysis indicated that heavy metals pollution of soils was induced by anthropogenic activities mostly, and the pollutants produced by traffic were the major source of heavy metals in road dust. (3) The order for heavy metal enrichment coefficients of vegetables was as following: Zn (0.589) > Cu (0.412) > 0.102 (Ni) > Cd (0.059) > Cr (0.061) > Hg (0.056) > Pb (0.012) > As (0.007), and the results indicated that Cd and Zn in vegetables were mainly from the soils, and the other metals were probably from the pollutants in the atmosphere. (4) Sediments in drinking water conservation area were probably derived from soils around; however, there was no significant relationship between heavy metals contents of them. (5) The results of ecological risk assessment of heavy metals showed that heavy metals in soils were in no-warning to warning situation, and warning to light-warning situation for road dust and vegetables. The fuzzy synthesis judgment for all the environmental media around drinking water conservation area was warning to light-warning.

[Risk factors and coronary angiographic findings in young and elderly patients with acute myocardial infarction: a comparative analysis].

OBJECTIVE: To identify the risk factors for acute myocardial infarction (AMI) and summarize the features of coronary angiographic (CAG) findings in young and elderly patients. METHODS: A case-control study was conducted involving 53 young (below 40 years) and 438 elderly (60 years and over) patients with clinical diagnosis of AMI. The differences in the risk factors, clinical characteristics and CAG findings were analyzed between the two groups. RESULTS: Compared with the elderly patients, the risk factors of smoking and positive family history was more frequently found among the young patients, but the rates of hypertension and diabetes were lower. The levels of triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and apolipoprotein B (ApoB) were significantly higher, while high-density lipoprotein cholesterol (HDL-C) lower in the young patients than in the elderly patients. Angiography identified higher incidence of one-vessel disease in the young patients (73.33% vs 25.09%), but the incidence of double-vessel and multi-vessel diseases was more frequent in the elderly patients (11.11% vs 27.49%, and 8.89% vs 47.01%), most commonly compromising the left anterior descending (LAD) coronary artery in both groups. Modified Gensini score of coronary angiography was lower in the young patients (7.69-/+5.23 vs 16.08-/+7.81). Correlation analysis showed that LDL-C (r=0.289, P=0.046) was positively correlated, while HDL-C (r=-0.589, P=0.01), ApoA-I(r=-0.395, P=0.023) were inversely correlated to the angiographic score. Multiple regression analysis showed a significant inverse linear correlation between HDL-C level and coronary artery stenosis. CONCLUSION: Smoking, metabolic disorders and positive family history are the major risk factors for AMI among individuals below the age of forty, who often have milder coronary artery stenosis than elderly patients. HDL-C variation is significantly correlated to the degree of coronary artery stenosis in young patients with AMI.

Modified classic risk factors for coronary artery disease in Chinese Han population.

OBJECTIVE: To investigate the levels of cardiovascular disease risk factors and their relations to clinical phenotype associated with coronary artery disease (CAD). METHODS: The subjects were recruited from five independent cardiovascular centers. Coronary angiography was employed to define the CAD with stenosis in each major vessel > or = 70% and control with stenosis < 10% in every lesion. The classic risk factors including family history, body mass index, smoking habits, hypertension, diabetes mellitus, and serum lipid levels were surveyed according to established criteria. Associations between risk levels and clinical phenotypes were assessed by case control and correlation analysis. RESULTS: A total of 762 individuals were collected, including 481 men and 281 women, aged from 17 to 81 (mean 60 +/- 10) years. The patients with CAD accounted for 55.5% of all participants, and controls 44.5%, respectively. Compared with the pattern in published data, our study showed that mean serum high density lipoprotein cholesterol (HDL-C) level was significantly lower (P < 0.001) and triglycerides was significantly higher (P < 0.001), while total cholesterol (TC) and low density lipoprotein cholesterol levels were comparative (both P > 0.05). The prevalence of low HDL-C (< 40 g/L) and hypertriglyceridemia (> 150 g/L) were 27.2% and 41.4%, respectively. Mean serum levels of HDL-C and apolipoprotein A1 were significantly higher in female subjects than in male (P < 0.001). Lower HDL-C functioned as an independent risk factor for CAD only in men (RR = 2.8, 95% CI: 1.5-4. 2, P < 0.001), yet increased non-HDL cholesterol combined with diabetes mellitus and obesity seemed to play a key role in the development of CAD in women. Similarity in risk association with CAD was found for hypertension and TC/HDL ratio in male and female subjects, while family history had no relationship with the presence of CAD. CONCLUSION: It is remarkable that emphasis of intervention in future should be given on the prevalent low serum HDL-C and its strong risk correlation with the presence of CAD in male subjects of Chinese Han population.

[Single nucleotide polymorphisms of genes associated with high density lipoprotein metabolism in Chinese population].

OBJECTIVE: To study the single nucleotide polymorphisms in genes associated with the high density lipoprotein (HDL) metabolism in Chinese population. METHODS: Two hundred and nine normal Han ethnic subjects, aged 59+/-10 years, were recruited from 5 medical centers in western part of China. DNA was extracted by proteinase K digestion, phenol and chloroform extraction as well as isopropanol precipitation. The polymerase chain reaction (PCR)-restriction fragment length polymorphisms (RFLP) in conjunction with sequencing were employed to test the single nucleotide polymorphisms (SNPs) in ATP-binding cassette transporter (ABCA1), cholesteryl ester transfer protein (CETP) and lipoprotein lipase (LPL) genes. RESULTS: The allelic frequencies of A and G of ABCA1 gene are 53.4% and 46.6%; of B2 and B1 allele of CETP, 41.0% and 59.0%; of HindIII (-) and (+) allele of LPL, 18.9% and 81.1%; and of PvuII(+) and (-) allele of LPL, 66.0% and 34.0%, respectively. All genotype frequencies fit well with the Hardy-Weinberg equilibrium; the significant linkage disequilibrium exists between LPL HindIII(+)and PvuII(+) polymorphisms. All of the RFLP in these genes result from the single nucleic substitution in fragment recognized by corresponding restriction enzymes. CONCLUSION: The genetic polymorphisms of ABCA1, LPL-HindIII and LPL-PvuII in Chinese Han ethnic population are significantly different from Caucasians residing in USA or Europe.

[Impact of macrofaunal activities on the DIN exchange at the sediment-water interface along the tidal flat of Yangtze River estuary].

The macrofaunal activities exert intensive and extensive influences on the accumulation, transportation, exchange and geochemistry processes of pollutants and redox sensitive elements around the sediment-water interface. Based on the simulated and contrastive analysis method, effects of bivalve Corbicula fluminea activities on dissolved inorganic nitrogen (DIN) exchange between sediment-water interface in different experimental conditions and nitrogen biogeochemical cycling along the tidal flats of Yangtze River estuary are discussed. In short time experiment, Corbicula fluminea burrowing activities increased NH4+ release from sediments, and NO3- efflux to overlying water was much more in Corbicula fluminea inhabiting core. During long time incubation, NH4- and N released in turn from the sediments, bioturation can facilitate NH4- release from the sediments at the beginning of incubation, and stronger nmistrification derived from bioturbation witin the sediments enlarge Nsedim concentration. Disturbance and bioirrigation of Corbicula flumuminea can accelerate organic matter mineralization and N(DIN) exchange between overlying water and pore water, result in a larger release from NH4+ pool in top-sediment to overlying water. In conclusion, by means of excretion, burrowing, bioirrigation and biotuary ation, Corbicula fluuminea burrowing activities can evidently modify the nitrogen dynamics in sediment-water system.

Curcumin ameliorates left ventricular function in rabbits with pressure overload: inhibition of the remodeling of the left ventricular collagen network associated with suppression of myocardial tumor necrosis factor-alpha and matrix metalloproteinase-2 expression.

OBJECTIVE: Curcumin is a wide-spectrum cellular protector with antiinflammatory, antioxidizant, and antifibrotic effects. This study was conducted to investigate its effects on myocardial collagen remodeling in pressure overloaded rabbits. METHODS AND RESULTS: Pressure overloaded rabbits were established by partial abdominal aorta ligation. The rabbits were divided into the sham-operation group, vehicle group and curcumin group. Curcumin was administered orally at a dose of 100 mg/kg.d in 10 ml of 2.5% polyethylene glycol solution and the other 2 groups were given the same dose of polyethylene glycol solution. Compared with the vehicle group, left ventricular function in the curcumin group was significantly ameliorated, as indicated by decreased left ventricular end-diastolic pressure, left ventricle weight to body weight ratio, and the left ventricular posterior wall thickness. The collagen volume fraction in the curcumin group was also reduced. Myocardial tumor necrosis factor (TNF)-alpha and matrix metalloproteinase (MMP)-2 expression were significantly overexpressed in the vehicle group and markedly suppressed in the curcumin group at both the 4th and 8th weeks. At the end of the 8th week, the ejection fraction in the curcumin group was increased compared with that in the vehicle group. CONCLUSION: Curcumin improved left ventricular function in pressure overloaded rabbits. This might be due to inhibition of collagen remodeling associated with suppression of myocardial expression of tumor necrosis factor-alpha, and matrix metalloproteinase-2.

A density functional theory investigation of the Simmons-Smith cyclopropanation reaction: examination of the insertion reaction of zinc into the C-I bond of CH(2)I(2) and subsequent cyclopropanation reactions.

The insertion reaction of zinc into the C-I bond of CH(2)I(2) and subsequent cyclopropanation reactions with CH(2)CH(2) have been investigated using B3LYP level density functional theory calculations. The Simmons-Smith cyclopropanation reaction of olefins does not proceed easily due to the relatively large barriers on the insertion and cyclopropanation pathways. The computed results indicate that the IZnCH(2)I molecule is the active reagent in the Simmons-Smith reaction. This is consistent with the IZnCH(2)I reactive species being generated from diiodomethane and a Zn-Cu couple as proposed by several other research groups. The Simmons-Smith IZnCH(2)I carbenoid and CH(2)I-I carbenoid cyclopropanation reactions with olefins are compared. The reactions of olefins with the radicals from the decomposition of the IZnCH(2)I and CH(2)I-I species were also compared. We found that the chemical reactivity of the carbenoid species is dependent on its electrophilic behavior, steric effects, the leaving group character and the mechanism of the cyclopropanation reactions.