Showing papers by "Duo Li published in 2012"

Cardiovascular disease mortality and cancer incidence in vegetarians: a meta-analysis and systematic review.

Abstract: Background: Prospective cohort studies have examined mortality and overall cancer incidence among vegetarians, but the results have been inconclusive. &l

Fish consumption and CHD mortality: an updated meta-analysis of seventeen cohort studies

Abstract: Objective: Results of studies on fish consumption and CHD mortality are inconsistent. The present updated meta-analysis was conducted to investigate the up-to-date pooling effects. Design: A random-effects model was used to pool the risk estimates. Generalized least-squares regression and restricted cubic splines were used to assess the possible dose‐response relationship. Subgroup analyses were conducted to examine the sources of heterogeneity. Setting: PubMed and ISI Web of Science databases up to September 2010 were searched and secondary referencing qualified for inclusion in the study. Subjects: Seventeen cohorts with 315812 participants and average follow-up period of 15?9 years were identified. Results: Compared with the lowest fish intake (,1 serving/month or 1‐3 servings/ month), the pooled relative risk (RR) of fish intake on CHD mortality was 0?84 (95% CI 0?75, 0?95) for low fish intake (1 serving/week), 0?79 (95% CI 0?67, 0?92) for moderate fish intake (2‐4 servings/week) and 0?83 (95% CI 0?68, 1?01) for high fish intake (.5 servings/week). The dose‐response analysis indicated that every 15g/d increment of fish intake decreased the risk of CHD mortality by 6% (RR 50?94; 95% CI 0?90, 0?98). The method of dietary assessment, gender and energy adjustment affected the results remarkably. Conclusions: Our results indicate that either low (1 serving/week) or moderate fish consumption (2‐4 servings/week) has a significantly beneficial effect on the prevention of CHD mortality. High fish consumption (.5 servings/week) possesses only a marginally protective effect on CHD mortality, possibly due to the limited studies included in this group.

Marine N-3 polyunsaturated fatty acids are inversely associated with risk of type 2 diabetes in Asians: a systematic review and meta-analysis.

Abstract: Background Prospective cohort studies in relation to the associations between n-3 polyunsaturated fatty acids (PUFA) and risk of type 2 diabetes (T2D) were inconsistent. Differences in tissue n-3 PUFA compositions in subjects with and without T2D were also inconsistent in both cohort and case-control studies. We conducted a systematic review and meta-analysis of prospective cohort studies to examine the associations of fish and n-3 PUFA intake with T2D risk. The differences in tissue n-3 PUFA compositions in subjects with and without T2D were investigated based on cohort and case-control studies. Methods and Findings PubMed, Embase, Cochrane library, China National Knowledge Infrastructure (CNKI) and Chinese VIP database up to January 2012 was used to identify relevant studies, and reference lists from retrieved studies were reviewed. Two authors independently extracted the data. Random-effects models were used to pool the summary relative risk (RR). Twenty-four studies including 24,509 T2D patients and 545,275 participants were identified. For cohort studies, the summary RR of T2D for the highest vs lowest categories of total fish, marine n-3 PUFA and alpha-linolenic acid intake was 1.07 (95% CI: 0.91, 1.25), 1.07 (95% CI: 0.95, 1.20) and 0.93 (95% CI: 0.81, 1.07), respectively. Subgroup analyses indicated that summary RR (highest vs lowest category) of T2D for fish and marine n-3 PUFA intake was 0.89 (95% CI: 0.81, 0.98) and 0.87 (95% CI: 0.79, 0.96) for Asian populations, and 1.20 (95% CI: 1.01, 1.44) and 1.16 (95% CI: 1.04, 1.28) for Western populations. Asian subjects with T2D had significantly lower tissue compositions of C22∶6n-3 (SMD: −1.43; 95% CI: −1.75, −1.12) and total n-3 PUFA (SMD: −1.41; 95% CI: −2.23, −0.59) compared with those without T2D. Conclusion This systematic review and meta-analysis provides evidence that marine n-3 PUFA have beneficial effects on the prevention of T2D in Asian populations.

Effect of n-3 polyunsaturated fatty acid on gene expression of the critical enzymes involved in homocysteine metabolism.

Abstract: Previous studies showed that plasma n-3 polyunsaturated fatty acid (PUFA) was negatively associated with plasma homocysteine (Hcy). We investigated the regulatory effect of n-3 PUFA on mRNA expression of the critical genes encoding the enzymes involved in Hcy metabolism. HepG2 cells were treated with docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), alpha-linolenic acid (ALA) respectively for 48 h. The cells were collected and total RNA was isolated. The mRNA expression levels of the genes were determined by using Real Time-PCR. Compared with controls, the mRNA expression levels of 5-methyltetrahydrofolate reductase (MTHFR) were significantly increased in the DHA group (p < 0.05) and ALA group (p < 0.05); Significantly down-regulated mRNA expression of methionine adenosyltransferase (MAT) was observed with the treatments compared with the controls; the level of MAT expression was significant lower in the DHA group than the ALA group (p < 0.05); Cystathionine-γ-lyase (CSE) expression was significantly increased in the DHA (p < 0.05) and EPA groups (p < 0.05) compared with control. No significant changes were shown in mRNA expression levels of S-adenosylhomocysteine hydrolases (SAHH), cystathionine β-synthase (CBS), and 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR). Our results suggest that DHA up-regulates CSE and MTHFR mRNA expression and down-regulates MAT mRNA expression involved in Hcy metabolism.

Ganoderma lucidum polysaccharides exert anti-hyperglycemic effect on streptozotocin-induced diabetic rats through affecting β-cells.

Abstract: Previous studies have demonstrated that Ganoderma lucidum polysaccharides (Gl-PS) exhibited potential antihyperglycemic effect in rats. The aim of the present study was to investigate the mechanism of the hypoglycemic effect of a low- molecular-weight Gl-PS in streptozotocin (STZ)-induced diabetic Sprague-Dawley (SD) rats. Gl-PS was extracted and purified from Ganodema lucidum fruiting body. 50 male SD rats were included in the study; 10 were taken as healthy controls; 40 were induced to diabetes by a single injection of 65 mg/kg STZ, of which 30 were selected as successful diabetic rat models. The 30 diabetic rats were divided into three groups: Gl-PS (200 mg/kg Gl-PS), metformin (100 mg/kg metformin) and diabetic control (n = 10 per group). After eight weeks' oral administration, plasma concentrations of fasting glucose, triacylglyceride, total cholesterol and nitric oxide were significantly decreased in Gl-PS and metformin groups. Pancreatic superoxide dismutase, catalase and glutathione peroxidase were significantly increased in Gl-PS and metformin groups. Histopathological results showed that Gl-PS and metformin had protective effect on β-cells. The mRNA expressions of Bcl-2 and PDX-1 in pancreas were up-regulated, but Bax, iNOS and Casp-3 down-regulated in Gl- PS and metformin groups compared to diabetic control group. The present results suggested that Gl-PS had a hypoglycemic effect in STZ-induced diabetic rats through preventing apoptosis of pancreatic β-cells and enhancing β-cells regeneration.

Electronic Tongue Coupled with Physicochemical Analysis for the Recognition of Orange Beverages

Abstract: A potentiometric electronic tongue (E-tongue) has been used to determine orange beverages of different brands to assess its recognition ability in beverage detection. Physicochemical indexes related to sensory quality have been measured to find correlation between electrochemical signals and physicochemical indexes of orange beverages. Analysis of variance, correlation analysis and principal component analysis (PCA) have been applied in such data processing. The sensor response signals have been analyzed by canonical discriminant analysis (CDA), cluster analysis (CA), and soft independent modeling of class analogy (SIMCA), and their classification effects have been compared. The results indicate that the E-tongue has good capability to discriminate different brands of orange beverages based on contents of their taste compounds. The correlation between electrochemical signals and physicochemical indexes is significant, and physicochemical indexes may be applied to explain the results of PCA, CDA, CA and SIMCA. CDA has a better classification effect in three methods. Practical Applications The detection and control of food quality are important parts in the food industry. Electronic tongue (E-tongue), as a promising technology, which can provide a simple, rapid and objective determination of food taste quality, is becoming popular in food analysis. This paper focuses on the application of an E-tongue in the recognition of different brands of beverages and finding the correlation between signals of the E-tongue and physicochemical indexes of beverages. The feasibility of E-tongue detection in food analysis is also concerned in our studies. The results presented confirm that the E-tongue has global discrimination ability, and that there is significant correlation between electrochemical signals and physicochemical indexes of orange beverages. All these results indicate that the E-tongue may be a potential analysis tool to be applied in food analysis.

Low Docosahexaenoic Acid Content in Plasma Phospholipids is Associated with Increased Non-alcoholic Fatty Liver Disease in China

Abstract: A large proportion of the Chinese population is now at risk of non-alcoholic fatty liver disease (NAFLD). We aimed to investigate the relationship between plasma phospholipids (PL) fatty acids and the risk of NAFLD. One hundred NAFLD patients and 100 healthy subjects were recruited in Hangzhou, China. Plasma PL and selected biochemical and hematological parameters were analyzed by using standard methods. Stepwise logistic regression was used to identify independent risk factors of NAFLD. Plasma PL total saturated fatty acid (SFA), C20:3n-6, serum alanine aminotransferase, high-density lipoprotein cholesterol, and body mass index were independent risk factors of NAFLD. The risk of NAFLD was significantly increased with higher quartiles of plasma PL total SFA (P for trend = 0.028) and C20:3n-6 (P for trend <0.001); plasma PL docosahexaenoic acid (C22:6n-3) was significantly lower in NAFLD patients than in controls (P = 0.032) and the OR of NAFLD in the highest quartile of C22:6n-3 was 0.41 (95 % CI = 0.17–0.97) compared with the lowest quartile. In conclusion, plasma PL total SFA and C20:3n-6 are positively correlated with the risk of NAFLD, while C22:6n-3 is negatively correlated with the risk of NAFLD.

Flyback type miniature photovoltaic grid connected inverter with power decoupling circuit and control method thereof

Abstract: A purpose of the present invention is disclosing a flyback type miniature photovoltaic grid connected inverter with a power decoupling circuit and a control method thereof The inverter comprises a flyback converter and a power frequency polarity conversion circuit The flyback converter is provided with a power decoupling circuit, a decoupling capacitance voltage grade is higher than output voltage of a solar energy photovoltaic array, decoupling capacitance voltage is allowed to fluctuate in a large range, thus decoupling capacitance capacity is decreased, power decoupling can be realized by only using a non-electrolytic capacitor, using an electrolytic capacitor is avoided, a service life of the miniature photovoltaic grid connected inverter is prolonged, and reliability is raised Through the control method, not only is decoupling of miniature photovoltaic grid connected inverter output power and solar energy photovoltaic array output power realized, but also direct current voltage and current waveform outputted by the solar energy photovoltaic array can maintain smooth, a service life of the solar energy photovoltaic array is guaranteed, and realization of maximum power point tracking (MPPT) is facilitated

A new mutation breeding method for Streptomyces albulus by an atmospheric and room temperature plasma

Abstract: e-Poly-L-lysine (e-PL) is a novel food biopreservative with broad antimicrobial activity. To improve the fermentation efficiency of e-PL, a plasma jet, driven by an active helium atom supplied with atmospheric and room temperature plasma (ARTP) biological breeding system, was used as a new method to generate mutations in Streptomyces albulus. After treating the spores with the ARTP jet, S-(2-aminoethyl)-L-cysteine plus glycine resistant mutants were derived. The plasma jet yielded high total (31.6%) and positive (26.0%) mutation rates on S. albulus and a mutated strain, designated as S. albulus A-29, showed a maximum productivity of 1.59 ± 0.08 mg/ml which was four times as much as that of the wild strain in the same culture condition. After 5-generation culture, the strain, S. albulusA-29 still maintained high productivity. This present study showed that the ARTP plasma jet has a strong mutagenic effect on S. albulus. Key words: Streptomyces albulus, mutation, atmospheric and room temperature plasma, e-PL yield

Determination of disialoganglioside GD3 and monosialoganglioside GM3 in infant formulas and whey protein concentrates by ultra-performance liquid chromatography/electrospray ionization tandem mass spectrometry

Abstract: A method of ultra-performance liquid chromatography combined with electrospray ionization triple quadrupole tandem mass spectrometry (UPLC-ESI-MS/MS) has been established for simultaneous determination of major disialoganglioside 3 (GD3) and monosialoganglioside 3 (GM3) in infant formulas and whey protein concentrates. Gangliosides were extracted by using the technique of Svennerholm and Fredman and then cleaned up with OASIS HLB solid-phase extraction (SPE) cartridges. The various molecular species of gangliosides were separated on an Acquity UPLC BEH C8 column and analyzed under the negative ion mode. GD3 and GM3 were rapidly quantified using internal standard (IS) method. The developed method was further validated by determining the linearity, average recovery, sensitivity (limit of quantification), and precision. The results presented high correlation coefficients (R(2) > 0.993) of the selected 16 gangliosides molecular species and provided the respective linear ranges. The limit of quantification was 0.325-0.734 mg/100 g for eight molecular species of GD3 and 0.008-0.312 mg/100 g for eight molecular species of GM3, respectively. The reasonable average recoveries (81-95%) and precision (relative standard deviation [RSD] ≤15%) were also demonstrated in three different spiked levels. This new method would be very useful in the quantitative determination of gangliosides in infant formulas and whey protein concentrates.

MAT1A variants modulate the effect of dietary fatty acids on plasma homocysteine concentrations

Abstract: Background and Aim Dietary n-3 polyunsaturated fatty acids (PUFAs) are associated with decreased plasma homocysteine (Hcy), an important biomarker for cardiovascular disease. The S-adenosylmethionine synthetase type-1 (MAT1A), an essential enzyme in the conversion of methionine to S-adenosylmethionine, plays a key role in homocysteine metabolism. This study investigated the interaction between dietary fatty acids and MAT1A genotypes on plasma Hcy concentrations among Boston Puerto Ricans. Methods and Results Plasma Hcy and MAT1A genotypes were determined in 994 subjects of the Boston Puerto Rican Health Study. Dietary fatty acid intakes were assessed by interviews using a questionnaire adapted from the NCI/Block food frequency form. Result In the cross-sectional analysis, genetic variant MAT1A 3U1510 displayed a significant interaction with dietary n-3:n-6 PUFA ratio in determining plasma Hcy ( p -value for interaction = 0.025). 3U1510G homozygotes had significantly lower plasma Hcy concentration than major allele homozygotes and heterozygotes (AA + AG) ( p -value for trend = 0.019) when the n-3:n-6 ratio was >0.09. Two other MAT1A variants, d18777 and i15752, also showed significant interactions with different constituents of dietary fat influencing Hcy concentrations. Furthermore, haplotypes consisting of three variants displayed a strong interaction with n3:n6 ratio influencing Hcy concentrations. Conclusions Our results suggest that MAT1A genotypes appear to modulate effects of dietary fat on plasma Hcy.

Effects of Geographical Origin on the Conjugated Linolenic Acid of Trichosanthes kirilowii Maxim Seed Oil

Abstract: Trichosanthes kirilowii Maxim (T. kirilowii) seeds from four geographical locations (Changxing, Quzhou, Yuexi, Dongzhi) contained 26.15–49.41% oil and 28.68–37.90% protein. The seed oil was distinguished by the conjugated linolenic acids, punicic acid (PA) and α-eleostearic acid (α-ESA). The main fatty acids in T. kirilowii seed oils were ranked in the following order: punicic acid (33.09–39.15%), linolenic acid (33.77–38.66%), oleic acid (15.15–24.88%), palmitic acid (2.36–4.86%). PA was the main isomer of CLNA (33.09–39.15%). No significant differences were found either in PA content or in α-ESA content of T. kirilowii seed from these geographical locations. Little difference was observed in the quantitative composition of the lipid contents of seeds from different geographical locations. The α-tocopherol content of T. kirilowii seed ranged from 6.34 to 31.74 mg/100 g, with the highest levels in Changxing seeds. The present results showed that T. kirilowii seeds were especially rich in PA, and their contents were not influenced by the geographical locations. Variation in some proximate compositions by geographical locations may be caused by ecological conditions, temperature, climate condition, technical and cultural conditions.

Plasma Phospholipid Polyunsaturated Fatty Acids and Homocysteine in Chinese Type 2 Diabetes Patients

Abstract: The main aim of the present study was to investigate the plasma phospholipids (PL) fatty acids status and its association with plasma Hcy in patients with type 2 diabetes mellitus (T2DM). One hundred and four T2DM (aged 57.3±13.4 y) and 150 healthy subjects (aged 48.4±8.7 y) were recruited. Plasma Hcy and PL fatty acids were determined by standard methods. Plasma Hcy concentration in T2DM was significantly higher than that in healthy subjects (p<0.001). The prevalence of hyperhomocysteinemia was significantly higher in T2DM (36.54%) than that in healthy subjects (17.32%) (p=0.012). Plasma PL 20:4n-6 (r=0.303, p=0.012), 22:5n-3 (r=0.312, p=0.01), total PUFA (r=0.303, p=0.012), n-6 PUFA (r=0.261, p=0.032) were significantly positively associated with plasma Hcy concentration in T2DM. While, plasma PL n-3:n-6 PUFA (r=-0.400, p=0.046) was negatively associated with plasma Hcy in T2DM. In healthy subjects, plasma PL 22:6n-3 (r=-0.201, p=0.042) was negatively associated with plasma Hcy. In addition, plasma PL 22:6n-3 (r=0.193, p=0.044) and 22:5n-6 (r=0.234, p=0.038) were significantly negatively associated with plasma vitamin B-12 in healthy subjects. Our results suggested that increased plasma Hcy levels in T2DM associated with low n-3:n-6 ratio intake. We suggest that T2DM increase their long chain n-3 PUFA intake from fish or fish oil while decrease n-6 PUFA intake.

Hypothalamic gene expression in ω-3 PUFA-deficient male rats before, and following, development of hypertension

Abstract: Dietary deficiency of ω-3 fatty acids (ω-3 DEF) produces hypertension in later life. This study examined the effect of ω-3 DEF on blood pressure and hypothalamic gene expression in young rats, before the development of hypertension, and in older rats following the onset of hypertension. Animals were fed experimental diets that were deficient in ω-3 fatty acids, sufficient in short-chain ω-3 fatty acids or sufficient in short- and long-chain ω-3 fatty acids, from the prenatal period until 10 or 36 weeks-of-age. There was no difference in blood pressure between groups at 10 weeks-of-age; however, at 36 weeks-of-age ω-3 DEF animals were hypertensive in relation to sufficient groups. At 10 weeks, expression of angiotensin-II1A receptors and dopamine D3 receptors were significantly increased in the hypothalamic tissue of ω-3 DEF animals. In contrast, at 36 weeks, α2a and β1 adrenergic receptor expression was significantly reduced in the ω-3 DEF group. Brain docosahexaenoic acid was significantly lower in ω-3 DEF group compared with sufficient groups. This study demonstrates that dietary ω-3 DEF causes changes both in the expression of key genes involved in central blood pressure regulation and in blood pressure. The data may indicate that hypertension resulting from ω-3 DEF is mediated by the central adrenergic system.

Associations of plasma n-3 polyunsaturated fatty acids with blood pressure and cardiovascular risk factors among Chinese.

Abstract: The relationship between plasma fatty acid (FA) levels and hypertension in Chinese is not fully understood. The aim of this study was to examine relationships between plasma phospholipid (PL) FAs and hypertension in Chinese subjects. One thousand one hundred and fifty-four subjects in Hangzhou, China, were recruited in this cross-sectional study. Two hundred and fourteen (160 males, 54 females) subjects with hypertension and 940 (664 males, 276 females) healthy subjects were identified. The prevalence of hypertension in females (19.6%) was significantly higher than that in males (16.4%). Compared with healthy subjects, hypertensive subjects showed significantly lower plasma PL 22:5n–3 (p = 0.017), 22:6n–3 (p = 0.008), PL polyunsaturated fatty acids (PUFAs; p < 0.001), n–3 PUFA (p = 0.015), n–6 PUFA (p < 0.001) and 20:4n–6 (p < 0.010). PL n–3 PUFA [odds ratio (OR) = 0.43, 95% confidence interval (CI) = 0.29–1.19] and n–3:n–6 (OR = 0.48, 95% CI = 0.12–1.86) were inversely associated with hypertension. Howev...

Effects of Chinese liquors on cardiovascular disease risk factors in healthy young humans.

Abstract: Objectives. To elucidate whether consumption of two Chinese liquors, tea-flavor liquor (TFL) and traditional Chinese liquor (TCL) have protective effects on cardiovascular disease (CVD) risk factors in healthy human subjects. Methods. Forty-five healthy subjects (23 men, 22 women), aged 23–28, were recruited and randomized into two groups: TFL and TCL, and consumed 30 mL/day (45% (v/v) alcohol) of either liquor for 28 days. Results. Serum high-density lipoprotein cholesterol/low-density lipoprotein cholesterol (HDL-C/LDL-C) and apolipoprotein A1 were significantly increased, and total cholesterol (TC) and TC/HDL-C were significantly decreased after the intervention in both groups (𝑃<0.05). Serum uric acid (𝑃=0.004 for TFL, 𝑃=0.001 for TCL), glucose (𝑃<0.001 for TFL, 𝑃<0.001 for TCL) and endothelial adhesion molecules (𝑃<0.05) were significantly decreased after the intervention. ADP-induced whole blood platelet aggregation was also significantly decreased after the intervention in both TFL and TCL groups (𝑃<0.05). Conclusions. TFL and TCL consumption had protective effects on CVD risk factors in young humans. However, the results were valid only for 28 days, and that the possibility of adverse effect (liver, kidney) of chronic alcohol consumption should be considered.

Flyback photovoltaic grid-connected inverter adopting interleaving parallel-connection active clamping technology

Abstract: The invention aims at disclosing a flyback photovoltaic grid-connected inverter adopting an interleaving parallel-connection active clamping technology. Two flyback circuits are in in-out parallel connection with each other, one auxiliary switch tube is respectively added to each flyback circuit, and drains of the two auxiliary switch tubes are connected with each other, are in series connection with a public clamping capacitor to form a clamping circuit and are respectively in parallel connection with two corresponding ends of a transformer primary side winding. An opening signal of one of the flyback circuit auxiliary switch tubes aligns with a closing signal of the other flyback circuit auxiliary switch tube, the alignment method guarantees that the duty ratio of the two flyback circuits is substantially maintained consistent, and the active clamping technology is achieved easily. The communicating time of the auxiliary switch tube of each flyback circuit can be calculated through a digital control circuit according to output voltage values at current moment and accurately controlled, and is suitable for wide-range output voltage occasions. The flyback photovoltaic grid-connected inverter reduces output current ripple, achieves leakage-inductance energy absorption and effective utilization, enhances circuit efficiency and improves electro-magnetic interference (EMI) characteristics of a high-frequency circuit.

Vegetarians, the Good, the Bad, and the Challenges

Abstract: Becoming a vegetarian has become increasingly popular over the past decade, with many people turning to vegetarianism in an attempt to achieve better health. However this trend is not without it’s controversy. Many doctors and scientists have opposing views on vegetarianism, and this has led to confusion in the public about whether it is indeed the healthier lifestyle choice. The major health advantage for vegetarians include decreased body mass index, waist to hip ratio, blood pressure, plasma total cholesterol (TC), triacylglycerol and LDL-C levels, serum lipoprotein(a) concentration, plasma factor VII activity, ratios of TC/HDL-C, LDL-C/ HDL-C and TAG/HDL-C, and serum ferritin levels. However, being a vegetarian is not without it’s disadvantages and health risks. Studies have shown that vegetarians, especially vegans tend to have lower serum levels of vitamin B12 compared with omnivores. Serum vitamin B12 concentration was significantly negatively correlated with plasma homocysteine. Remethylation of homocysteine to methionine requires vitamin B12 (methylcobalamin form) as a coenzyme for homocysteine methyltransferase (methionine synthetase) and N5-methyltetrahydrofolate as a methyl donor [1]. Vitamin B12 is essential for new cell synthesis, blood formation, maintenance of the nervous system. Vitamin B12, as a coenzyme increases the utilization of folic acid and metabolism of carbohydrate, fat and protein etc. In the vitamins, B12 is the only one containing a mineral (cobalt), it also known as the red vitamin. Seafood, animal meats, eggs and liver are good sources for vitamin B12. Vitamin B12 is not found in plant foods, however, seaweed may contain vitamin B12 analogs which can be counted on as reliable sources of active vitamin B12. Ovo-lacto vegetarians may get vitamin B12 from eggs and dairy products. Vegans could get some very limited vitamin B12 from fermented soybean products, seaweed and edible fungi (like mushrooms) on farms or in the wild which may be contaminated from bacteria in the soil.