Crystallinity and lattice vacancies of different mesoporous g-C3N4 for photodegradation of tetracycline and its cytotoxic implication.

Tetracycline (TC) antibiotic removal from water bodies is important to provide clean water and sanitation. Mesoporous graphitic carbon nitride (GCN) photocatalyst derived from three different types of precursors manages to remove TC effectively under visible light irradiation. Among urea, thiourea, and melamine precursors, melamine-prepared GCN (MGCN) via thermal polymerization has the highest efficiency to photodegrade tetracycline (TC) antibiotics up to 99.5% (0.0122 min-1) within 240 min. The COD for TC removal by using MGCN was up to 77.5% after 240 min of degradation. This is due to the slow charge recombination and rapid charge carrier migration. The MGCN encounters different properties such as high crystallinity, dense structure allowing fast charges migration, and nitrogen vacancies that create a defect state that suppresses charge recombination. It was found that the conduction band (CB) of MGCN was located at a more negative position (ECB = -0.33 V) than (O2/O2•-) and the valence band (VB) was placed at a more positive position (EVB = 2.30 V) than (H2O/OH•), which allows generation of both radicals for photodegradation. Based on the cell viability test, the photodegraded TC in the water how non-toxicity toward Balb/c 3T3 cells after being irradiated (λ > 420 nm) for 240 min under visible light. The MGCN prepared in this study demonstrated the highest effectiveness and recyclable photocatalyst for the removal of TC among all GCNs.

An Effective Electrodeposition Mode for Porous MnO2/Ni Foam Composite for Asymmetric Supercapacitors.

Three kinds of MnO2/Ni foam composite electrode with hierarchical meso-macroporous structures were prepared using potentiodynamic (PD), potentiostatic (PS), and a combination of PS and PD(PS + PD) modes of electrodeposition. The electrodeposition mode markedly influenced the surface morphological, textural, and supercapacitive properties of the MnO2/Ni electrodes. The supercapacitive performance of the MnO2/Ni electrode obtained via PS + PD(PS + PD(MnO2/Ni)) was found to be superior to those of MnO2/Ni electrodes obtained via PD and PS, respectively. Moreover, an asymmetric supercapacitor device, activated carbon (AC)/PS + PD(MnO2/Ni), utilizing PS + PD(MnO2/Ni) as a positive electrode and AC as a negative electrode, was fabricated. The device exhibited an energy density of 7.7 Wh·kg-1 at a power density of 600 W·kg-1 and superior cycling stability, retaining 98% of its initial capacity after 10,000 cycles. The good supercapacitive performance and excellent stability of the AC/PS + PD(MnO2/Ni) device can be ascribed to its high surface area, hierarchical structure, and interconnected three-dimensional reticular configuration of the nickel metal support, which facilitates electrolyte ion intercalation and deintercalation at the electrode/electrolyte interface and mitigates volume change during repeated charge/discharge cycling. These results demonstrate the great potential of the combination of PS and PD modes for MnO2 electrodeposition for the development of high-performance electrodes for supercapacitors.

The associations of LPIN1 gene expression in adipose tissue with metabolic phenotypes in the Chinese population.

The LPIN1 gene, encoding lipin-1 protein, plays critical roles in adipocyte differentiation and lipid metabolism. This study aimed to analyze the association of LPIN1 mRNA levels in human adipose tissue with metabolic phenotypes. We also examined the association of LPIN1 genetic variation with type 2 diabetes and related metabolic phenotypes in the Chinese population. The relative LPIN1 mRNA levels were measured in abdominal visceral (VAT) and subcutaneous adipose tissue (SAT) obtained from 102 nondiabetic Chinese females. Seven single-nucleotide polymorphisms (SNPs) spanning from the 5'-upstream region to the 3'-end of the LPIN1 gene were genotyped in 1,520 Chinese (760 type 2 diabetic cases and 760 controls). LPIN1 mRNA levels in VAT were negatively correlated with BMI (r = -0.21, P = 0.03), body fat percentage (r = -0.22, P = 0.02), plasma triglycerides levels (r = -0.21, P = 0.03), and plasma leptin levels (r = -0.63, P = 0.0002). LPIN1 mRNA levels were positively correlated with PPARG and ADIPOQ mRNA levels in both VAT and SAT. No single SNP of the LPIN1 gene was associated with type 2 diabetes in our population. One rare haplotype showed a significant association with type 2 diabetes (odds ratio (OR), 4.35; 95% confidence interval, 1.86-11.75; P = 4 x 10(-4)). No SNP or haplotype of the LPIN1 gene was associated with quantitative metabolic traits in the nondiabetic subjects. The results confirmed the association of LPIN1 gene expression in adipose tissue with lower adiposity and favorable metabolic profiles in the Chinese population. However, the LPIN1 gene seemed not to be a major susceptibility gene for type 2 diabetes or related metabolic phenotypes in the Chinese population.

Genetic variants of TCF7L2 are associated with insulin resistance and related metabolic phenotypes in Taiwanese adolescents and Caucasian young adults.

OBJECTIVES: The effect of TCF7L2 rs7903146 on glucose homeostasis is considered primarily due to impaired insulin secretion in European populations. Because we previously demonstrated that TCF7L2 rs290487 near the 3' end of TCF7L2 was significantly associated with type 2 diabetes (T2D) in Taiwanese subjects, we aimed to investigate potential mechanisms underlying the associations of rs290487 with T2D. METHODS: Eighteen single nucleotide polymorphisms (SNPs) were tested for association with glucose/insulin homeostasis as well as other quantitative metabolic phenotypes using the quantitative transmission disequilibrium test in 525 Taiwanese adolescent twin-pairs and siblings. The results were further replicated in 116 nondiabetic normotensive Caucasian young adults. RESULTS: Among the 18 SNPs, rs290487 C allele was significantly associated with higher 60-, 90-, and 120-min glucose concentrations (P = 0.001, 0.01, and 0.02, respectively); higher 60- and 90-min insulin concentrations (P = 0.01 and 0.01, respectively); and a lower insulin sensitivity index (P = 0.04). No association was found for rs290487 with measures of insulin secretion. The rs290487 C allele was also associated with HOMA-IR (P = 0.005) and insulin sensitivity index (P = 0.01) in Caucasian young adults. Another SNP, rs10749127 C allele located in intron 4, was also associated with features of the metabolic syndrome, including elevated systolic (P = 0.02) and diastolic (P = 2.0 x 10(-4)) blood pressure, triglycerides (P = 7.0 x 10(-4)), and uric acid (P = 0.03). In a meta-analysis, the rs290487 C allele was confirmed to be associated with an increased risk of T2D (odds ratio, 1.11; 95% confidence interval, 1.03-1.19; P = 0.005) across East Asian populations. CONCLUSIONS: These findings support an important role for T2D risk-conferring gene TCF7L2 in insulin resistance in both Taiwanese and Caucasian youth and underscore the emerging role of Wnt signaling in insulin resistance.

Expression of subcutaneous adipose tissue phosphoenolpyruvate carboxykinase correlates with body mass index in nondiabetic women.

Phosphoenolpyruvate carboxykinase (PEPCK) is a key enzyme for glyceroneogenesis in adipose tissues. Dysregulated glyceroneogenesis is associated with abnormal fatty acid homeostasis, obesity, and insulin resistance in both animal and cellular studies. However, the role of PEPCK expression in human adipose tissues on metabolic phenotypes has not been explored. This study aimed to analyze the correlation between PEPCK messenger RNA (mRNA) expressions in the subcutaneous adipose tissues with obesity-related metabolic phenotypes. We obtained the demographic data, biochemical variables, and abdominal subcutaneous adipose tissue from 75 nondiabetic nonmenopausal women. The relative PEPCK mRNA levels were quantified by real-time polymerase chain reaction normalized with beta-actin as a control. The PEPCK mRNA levels of subcutaneous tissue were positively correlated with body mass index (BMI) using either univariate (r = 0.413, P < .001) or multivariate linear regression analysis (beta = .978 +/- .239, P < .001). The mRNA expression of PEPCK was also positively correlated with body fat percentage (r = 0.436, P < .001), plasma triacylglycerol, and total cholesterol levels (both P values < .001). However, the significant correlation between lipid profile and PEPCK expression in subcutaneous tissue was abolished after adjusting for BMI. The relative subcutaneous PEPCK mRNA level was not correlated with fasting plasma glucose and insulin, and with an insulin resistance index measured with homeostasis model assessment. In conclusion, we showed that PEPCK mRNA expression in the subcutaneous adipose tissues was associated with BMI and plasma triacylglycerol and total cholesterol levels, but was not correlated with insulin resistance index.

Association study of the genetic polymorphisms of the transcription factor 7-like 2 (TCF7L2) gene and type 2 diabetes in the Chinese population.

OBJECTIVE: Genetic polymorphisms of the transcription factor 7-like 2 (TCF7L2) gene is one of the few validated genetic variants with large effects on the risk of type 2 diabetes in the populations of European ancestry. In this study, we aimed to explore the effect of the TCF7L2 polymorphisms in a Han Chinese population. RESEARCH DESIGN AND METHODS: We genotyped 20 single nucleotide polymorphisms (SNPs) across the TCF7L2 gene in 1,520 unrelated subjects from a Han Chinese population in Taiwan. The associations of SNPs and haplotypes with type 2 diabetes and linkage disequilibrium (LD) structure of the TCF7L2 gene were analyzed. RESULTS: The previously reported SNPs rs7903146 T- and rs12255372 T-alleles of the TCF7L2 gene were rare and were not associated with type 2 diabetes in a Chinese population, which may attribute to the low frequencies of these two SNPs. SNP rs290487 located in an LD block close to the 3' end of the gene was associated with type 2 diabetes (allele-specific P = 0.0021; permuted P = 0.03). The odds ratio was 1.36 for the CT genotype (95% CI 1.08-1.71; P = 0.0063) and 1.51 for the CC genotype (1.10 -2.07; P = 0.0085) compared with the TT genotype, corresponding to a population attributable risk fraction of 18.7%. The haplotypes composed of rs290487 were also significantly associated with type 2 diabetes (global P = 0.012). CONCLUSIONS: We identified a novel risk-conferring genetic variant of TCF7L2 for type 2 diabetes in a Chinese population. Our data suggested that the TCF7L2 genetic polymorphisms are major determinants for risk of type 2 diabetes in the Chinese population.

Allele-specific differential expression of a common adiponectin gene polymorphism related to obesity.

Adiponectin gene polymorphisms have recently been reported to be associated with obesity, insulin sensitivity, and the risk of type 2 diabetes. We examined a T94G polymorphism of the adiponectin gene in 245 ostensibly normal nondiabetic subjects. The G allele frequency was lower among subjects with higher BMI (> or =27) than in those with lower BMI. BMI was inversely correlated with the dose of G allele. Multivariate linear regression analyses showed that the adiponectin genotypes were significantly related to BMI after adjusting for age and gender. The dose of the G allele was associated with a reduction of approximately 1.12 kg/m(2) in BMI. We further found that the relative mRNA levels of G allele were consistently higher than those of T allele in the omental adipose tissue from 21 heterozygous subjects. Finally, we observed that the expression levels of adiponectin affected insulin-stimulated glucose uptake in differentiated 3T3-L1 adipocytes. In conclusion, the allele-specific differential expression of this common polymorphism could be responsible for its biological effects observed in this and the other studies.

mRNA levels of the insulin-signaling molecule SORBS1 in the adipose depots of nondiabetic women.

OBJECTIVES: The SORBS1 gene has been shown to be an important adaptor protein in the insulin-signaling pathway in many molecular and cellular biology studies. However, its roles in humans either in health or disease are rarely explored. In this report, we measured the SORBS1 mRNA levels in human adipose tissues. RESEARCH METHODS AND PROCEDURES: Adipose tissues of both the abdominal subcutaneous and omental depots were obtained from 62 nondiabetic women. The relative SORBS1 mRNA levels were quantified using real-time polymerase chain reaction. RESULTS: The relative SORBS1 mRNA levels from these two depots significantly correlated with each other (gamma = 0.85, p = 0.0000). The relative SORBS1 mRNA levels in the omental depots were lower than those in the subcutaneous depots (p = 0.053 by two-tailed test, p = 0.026 by one-tailed paired Student's t test). The mean SORBS1 expression level in the omental depots was approximately 70% that in the subcutaneous depots. Moreover, the relative SORBS1 mRNA levels in the omental depots were significantly related to BMI using either correlation analysis (gamma = -0.41, p = 0.0008) or multivariate linear regression analysis (beta = -0.20 +/- 0.09, p = 0.031) with adjustment for age, plasma glucose, serum insulin, triglyceride, and total cholesterol levels. DISCUSSION: Our preliminary results indicate the depot-specific differential expression of SORBS1 in relation to BMI. Further investigation of the functional significance of this phenomenon in human obesity is warranted.

The Arg16Gly polymorphism of human beta2-adrenoreceptor is associated with type 2 diabetes in Taiwanese people.

OBJECTIVE: The significance of the association of amino terminal polymorphisms in beta2-adrenoreceptor (ADRB2) with obesity and type 2 diabetes is controversial and differs among ethnic groups. In this study, the association of ADRB2 with risk and age of onset of type 2 diabetes has been examined in a Taiwanese population. DESIGN: The study design is a case-control study to investigate the impact of the two amino acid polymorphisms in ADRB2. PATIENTS AND MEASUREMENTS: This study includes 130 patients with type 2 diabetes [female : male = 1 : 1, age: 52.4 +/- 10.0 years; body mass index (BMI): 24.2 +/- 2.9 kg/m2; mean +/- SD] and 130 controlled subjects matched for gender, age and BMI with normal glucose tolerance (female : male = 1 : 1, age: 51.7 +/- 10.6 years; BMI: 23.9 +/- 2.7 kg/m2). The Arg16Gly and Gln27Glu polymorphisms of ADRB2 were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assays. The genotypic and allelic frequencies between two groups were compared and the relationship between the genotypes and clinical phenotypes was examined. RESULTS: A difference in genotypic frequency in the Arg16Gly polymorphism was noted between groups in this gender-, age- and BMI-matched case-control study (P = 0.039). Multivariate regression analysis revealed that the Arg16Gly polymorphism was the only independent factor for development of type 2 diabetes (P = 0.021). In addition, we utilized the log-rank test to compare the differences in age of onset between wild-type and nonwild-type polymorphisms. The Arg16Gly polymorphism was independently associated with age of onset in type 2 diabetes (P = 0.017). There was no difference in the Gln27Glu polymorphism between diabetic and control groups in this study. CONCLUSIONS: In a Taiwanese population, homozygosity of Arg16 in the ADRB2 gene was associated with a higher frequency (odds ratio 1.87, 95% confidence interval 1.34-2.40) for development of type 2 diabetes. Moreover, this polymorphism was also associated with an earlier onset of type 2 diabetes. However, the Glu27Gln polymorphism had no impact on either BMI or type 2 diabetes in a Taiwanese population.