Heterogeneous reactions of HNO3(g) + NaCl(s) yields HCl(g) + NaNO3(s) and N2O5(g) + NaCl(s) yields ClNO2(g) + NaNO3(s)

NASA Technical Reports Server (NTRS)

Leu, Ming-Taun; Timonen, Raimo S.; Keyser, Leon F.; Yung, Yuk L.

1995-01-01

The heterogeneous reactions of HNO3(g) + NaCl(s) yields HCl(g) + NaNO3(s) (eq 1) and N2O5(g) + NaCl(s) yields ClNO2(g) + NaNO3(S) (eq 2) were investigated over the temperature range 223-296 K in a flow-tube reactor coupled to a quadrupole mass spectrometer. Either a chemical ionization mass spectrometer (CIMS) or an electron-impact ionization mass spectrometer (EIMS) was used to provide suitable detection sensitivity and selectivity. In order to mimic atmospheric conditions, partial pressures of HNO3 and N2O5 in the range 6 x 10(exp -8) - 2 x 10(exp -6) Torr were used. Granule sizes and surface roughness of the solid NaCl substrates were determined by using a scanning electron microscope. For dry NaCl substrates, decay rates of HNO3 were used to obtain gamma(1) = 0.013 +/- 0.004 (1sigma) at 296 K and > 0.008 at 223 K, respectively. The error quoted is the statistical error. After all corrections were made, the overall error, including systematic error, was estimated to be about a factor of 2. HCl was found to be the sole gas-phase product of reaction 1. The mechanism changed from heterogeneous reaction to predominantly physical adsorption when the reactor was cooled from 296 to 223 K. For reaction 2 using dry salts, gamma(2) was found to be less than 1.0 x 10(exp -4) at both 223 and 296 K. The gas-phase reaction product was identified as ClNO2 in previous studies using an infrared spectrometer. An enhancement in reaction probability was observed if water was not completely removed from salt surfaces, probably due to the reaction of N2O5(g) + H2O(s) yields 2HNO3(g). Our results are compared with previous literature values obtained using different experimental techniques and conditions. The implications of the present results for the enhancement of the hydrogen chloride column density in the lower stratosphere after the El Chichon volcanic eruption and for the chemistry of HCl and HNO3 in the marine troposphere are discussed.

IgG4-related prostatitis progressed from localized IgG4-related lymphadenopathy.

PubMed

Li, Dujuan; Kan, Yunzhen; Fu, Fangfang; Wang, Shuhuan; Shi, Ligang; Liu, Jie; Kong, Lingfei

2015-01-01

Immunoglobulin G4-related disease (IgG4-RD) is a recently described inflammatory disease involving multiple organs. Prostate involvement with IgG4-RD is very rare. In this report, we describe a case of IgG4-related prostatitis progressed from localized IgG4-related lymphadenopathy. This patient was present with urine retention symptoms. MRI and CT examination revealed the prostatic enlargement and the multiple lymphadenopathy. Serum IgG4 levels were elevated. Prostatic tissue samples resected both this time and less than 1 year earlier showed the same histological type of prostatitis with histopathologic and immunohistochemical findings characteristic of IgG4-RD. The right submandibular lymph nodes excised 2 years earlier were eventually proven to be follicular hyperplasia-type IgG4-related lymphadenopathy. This is the first case of IgG4-RD that began as localized IgG4-related lymphadenopathy and progressed into a systemic disease involving prostate and multiple lymph nodes. This patient showed a good response to steroid therapy. This leads us to advocate a novel pathogenesis of prostatitis, and a novel therapeutic approach against prostatitis. Pathologists and urologists should consider this disease entity in the patients with elevated serum IgG4 levels and the symptoms of prostatic hyperplasia to avoid ineffective medical or unnecessary surgical treatment.

Downlink power distributions for 2G and 3G mobile communication networks.

PubMed

Colombi, Davide; Thors, Björn; Persson, Tomas; Wirén, Niklas; Larsson, Lars-Eric; Jonsson, Mikael; Törnevik, Christer

2013-12-01

Knowledge of realistic power levels is key when conducting accurate EMF exposure assessments. In this study, downlink output power distributions for radio base stations in 2G and 3G mobile communication networks have been assessed. The distributions were obtained from network measurement data collected from the Operations Support System, which normally is used for network monitoring and management. Significant amounts of data were gathered simultaneously for large sets of radio base stations covering wide geographical areas and different environments. The method was validated with in situ measurements. For the 3G network, the 90th percentile of the averaged output power during high traffic hours was found to be 43 % of the maximum available power. The corresponding number for 2G, with two or more transceivers installed, was 65 % or below.

Supersymmetric M3-branes and G2 manifolds

NASA Astrophysics Data System (ADS)

Cvetič, M.; Gibbons, G. W.; Lü, H.; Pope, C. N.

2002-01-01

We obtain a generalisation of the original complete Ricci-flat metric of G2 holonomy on R4×S 3 to a family with a nontrivial parameter λ. For generic λ the solution is singular, but it is regular when λ={-1,0,+1}. The case λ=0 corresponds to the original G2 metric, and λ={-1,1} are related to this by an S3 automorphism of the SU(2) 3 isometry group that acts on the S3× S3 principal orbits. We then construct explicit supersymmetric M3-brane solutions in D=11 supergravity, where the transverse space is a deformation of this class of G2 metrics. These are solutions of a system of first-order differential equations coming from a superpotential. We also find M3-branes in the deformed backgrounds of new G2 holonomy metrics that include one found by A. Brandhuber, J. Gomis, S. Gubser and S. Gukov, and show that they also are supersymmetric.

Nuclease digestion and mass spectrometric characterization of oligodeoxyribonucleotides containing 1,2-GpG, 1,2-ApG, and 1,3-GpXpG cisplatin intrastrand cross-links.

PubMed

Williams, Renee T; Nalbandian, Jenifer N; Tu, Audrey; Wang, Yinsheng

2013-05-01

The primary mode of action for cis-diamminedichloroplatinum (II), referred to as cisplatin, toward the treatment of solid malignancies is through formation of cross-links with DNA at purine sites, especially guanines. We prepared oligodeoxyribonucleotides (ODNs) containing a 1,2-GpG, 1,2-ApG, or 1,3-GpXpG cisplatin intrastrand cross-link and the corresponding ODNs modified with (15)N2-labeled cisplatin, and characterized these ODNs with electrospray ionization mass spectrometry (ESI-MS) and tandem MS (MS/MS). We also employed LC-MS/MS to characterize the digestion products of these ODNs after treatment with a cocktail of 4 enzymes (nuclease P1, phosphodiesterases I and II, and alkaline phosphatase). 1,2-GpG was released from the ODNs as a dinucleoside monophosphate or a dinucleotide. Analyses of the digestion products of ODNs containing a 1,2-GpG cross-link on the 5' or 3' terminus revealed that the dinucleotide carries a terminal 5' phosphate. On the other hand, digestion of the 1,3-GpXpG intrastrand cross-link yielded 3 dinucleoside products with 0, 1, or 2 phosphate groups. The availability of the ODNs carrying the stable isotope-labeled lesions, MS/MS analyses of the cisplatin-modified ODNs, and the characterization of the enzymatic digestion products of these ODNs set the stage for the future LC-MS/MS quantification of the 1,2-GpG, 1,2-ApG, and 1,3-GpXpG lesions in cellular DNA. Copyright © 2012 Elsevier B.V. All rights reserved.

Nuclease Digestion and Mass Spectrometric Characterization of Oligodeoxyribonucleotides Containing 1,2-GpG, 1,2-ApG, and 1,3-GpXpG Cisplatin Intrastrand Cross-links

PubMed Central

Williams, Renee T.; Nalbandian, Jenifer; Tu, Audrey; Wang, Yinsheng

2013-01-01

Background The primary mode of action for cis-diamminedichloroplatinum (II), referred to as cisplatin, towards the treatment of solid malignancies is through formation of cross-links with DNA at purine sites, especially guanines. Methods We prepared oligodeoxyribonucleotides (ODNs) containing a 1,2-GpG, 1,2-ApG, or 1,3-GpXpG cisplatin intrastrand cross-link and the corresponding ODNs modified with 15N2-labeled cisplatin, and characterized these ODNs with electrospray ionization mass spectrometry (ESI-MS) and tandem MS (MS/MS). We also employed LC-MS/MS to characterize the digestion products of these ODNs after treatment with a cocktail of 4 enzymes (nuclease P1, phosphodiesterases I and II, and alkaline phosphatase). Results 1,2-GpG was released from the ODNs as a dinucleoside monophosphate or a dinucleotide. Analyses of the digestion products of ODNs containing a 1,2-GpG cross-link on the 5′ or 3′ terminus revealed that the dinucleotide carries a terminal 5′ phosphate. On the other hand, digestion of the 1,3-GpXpG intrastrand cross-link yielded 3 dinucleoside products with 0, 1, or 2 phosphate groups. Results The availability of the ODNs carrying the stable isotope-labeled lesions, MS/MS analyses of the cisplatin-modified ODNs, and the characterization of the enzymatic digestion products of these ODNs set the stage for the future LC-MS/MS quantification of the 1,2-GpG, 1,2-ApG, and 1,3-GpXpG lesions in cellular DNA. PMID:23266768

A review on g-C3N4 for photocatalytic water splitting and CO2 reduction

NASA Astrophysics Data System (ADS)

Ye, Sheng; Wang, Rong; Wu, Ming-Zai; Yuan, Yu-Peng

2015-12-01

Solar fuel generation through water splitting and CO2 photoreduction is an ideal route to provide the renewable energy sources and mitigate global warming. The main challenge in photocatalysis is finding a low-cost photocatalyst that can work efficiently to split water into hydrogen and reduce CO2 to hydrocarbon fuels. Metal-free g-C3N4 photocatalyst shows great potentials for solar fuel production. In this mini review, we summarize the most current advances on novel design idea and new synthesis strategy for g-C3N4 preparation, insightful ideas on extending optical absorption of pristine g-C3N4, overall water splitting and CO2 photoreduction over g-C3N4 based systems. The research challenges and perspectives on g-C3N4 based photocatalysts were also suggested.

Enhanced visible light photocatalytic H2-production of g-C3N4/WS2 composite heterostructures

NASA Astrophysics Data System (ADS)

Akple, Maxwell Selase; Low, Jingxiang; Wageh, S.; Al-Ghamdi, Ahmed. A.; Yu, Jiaguo; Zhang, Jun

2015-12-01

As a clean and renewable solar H2-production system to address the increasing global environmental crisis and energy demand, photocatalytic hydrogen production from water splitting using earth abundant materials has received a lot of attention. In this study, WS2-graphitic carbon nitride (g-C3N4) composites were prepared using WO3 and thiourea as precursors through a gas-solid reaction. Different amount of WS2 were loaded on g-C3N4 to form the heterostructures and the composite samples exhibited enhanced photocatalytic activity for H2 production under visible light. The composite sample with 0.01 wt% WS2 exhibited the highest H2-production rate of 101 μmol g-1 h-1, which was even better than that of the Pt-C3N4 sample with the same loading content. The high photocatalytic activity was attributed to the formation of heterojunction between g-C3N4 and WS2 cocatalyst which allowed for effective separation of photogenerated charge carriers. This work showed the possibility for the utilization of low cost WS2 as an efficient cocatalyst to promote the photocatalytic H2 production of g-C3N4.

New application of Z-scheme Ag3PO4/g-C3N4 composite in converting CO2 to fuel.

PubMed

He, Yiming; Zhang, Lihong; Teng, Botao; Fan, Maohong

2015-01-06

This research was designed for the first time to investigate the activities of photocatalytic composite, Ag3PO4/g-C3N4, in converting CO2 to fuels under simulated sunlight irradiation. The composite was synthesized using a simple in situ deposition method and characterized by various techniques including Brunauer-Emmett-Teller method (BET), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), photoluminescence spectroscopy (PL), and an electrochemical method. Thorough investigation indicated that the composite consisted of Ag3PO4, Ag, and g-C3N4. The introduction of Ag3PO4 on g-C3N4 promoted its light absorption performance. However, more significant was the formation of heterojunction structure between Ag3PO4 and g-C3N4, which efficiently promoted the separation of electron-hole pairs by a Z-scheme mechanism and ultimately enhanced the photocatalytic CO2 reduction performance of the Ag3PO4/g-C3N4. The optimal Ag3PO4/g-C3N4 photocatalyst showed a CO2 conversion rate of 57.5 μmol · h(-1) · gcat(-1), which was 6.1 and 10.4 times higher than those of g-C3N4 and P25, respectively, under simulated sunlight irradiation. The work found a new application of the photocatalyst, Ag3PO4/g-C3N4, in simultaneous environmental protection and energy production.

Plasminogen activator inhibitor-1 4G/5G polymorphism and retinopathy risk in type 2 diabetes: a meta-analysis.

PubMed

Zhang, Tengyue; Pang, Chong; Li, Ningdong; Zhou, Elaine; Zhao, Kanxing

2013-01-02

Mounting evidence has suggested that plasminogen activator inhibitor-1 (PAI-1) is a candidate for increased risk of diabetic retinopathy. Studies have reported that insertion/deletion polymorphism in the PAI-1 gene may influence the risk of this disease. To comprehensively address this issue, we performed a meta-analysis to evaluate the association of PAI-1 4G/5G polymorphism with diabetic retinopathy in type 2 diabetes. Data were retrieved in a systematic manner and analyzed using Review Manager and STATA Statistical Software. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations. Nine studies with 1, 217 cases and 1, 459 controls were included. Allelic and genotypic comparisons between cases and controls were evaluated. Overall analysis suggests a marginal association of the 4G/5G polymorphism with diabetic retinopathy (for 4G versus 5G: OR 1.13, 95%CI 1.01 to 1.26; for 4G/4G versus 5G/5G: OR 1.30, 95%CI 1.04 to 1.64; for 4G/4G versus 5G/5G + 4G/5G: OR 1.26, 95%CI 1.05 to 1.52). In subgroup analysis by ethnicity, we found an association among the Caucasian population (for 4G versus 5G: OR 1.14, 95% CI 1.00 to 1.30; for 4G/4G versus 5G/5G: OR 1.33, 95%CI 1.02 to 1.74; for 4G/4G versus 5G/5G + 4G/5G: OR 1.41, 95%CI 1.13 to 1.77). When stratified by the average duration of diabetes, patients with diabetes histories longer than 10 years have an elevated susceptibility to diabetic retinopathy than those with shorter histories (for 4G/4G versus 5G/5G: OR 1.47, 95%CI 1.08 to 2.00). We also detected a higher risk in hospital-based studies (for 4G/4G versus 5G/5G+4G/5G: OR 1.27, 95%CI 1.02 to 1.57). The present meta-analysis suggested that 4G/5G polymorphism in the PAI-1 gene potentially increased the risk of diabetic retinopathy in type 2 diabetes and showed a discrepancy in different ethnicities. A higher susceptibility in patients with longer duration of diabetes (more than 10 years) indicated a gene

Plasminogen activator inhibitor-1 4G/5G polymorphism and retinopathy risk in type 2 diabetes: a meta-analysis

PubMed Central

2013-01-01

Background Mounting evidence has suggested that plasminogen activator inhibitor-1 (PAI-1) is a candidate for increased risk of diabetic retinopathy. Studies have reported that insertion/deletion polymorphism in the PAI-1 gene may influence the risk of this disease. To comprehensively address this issue, we performed a meta-analysis to evaluate the association of PAI-1 4G/5G polymorphism with diabetic retinopathy in type 2 diabetes. Methods Data were retrieved in a systematic manner and analyzed using Review Manager and STATA Statistical Software. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations. Results Nine studies with 1, 217 cases and 1, 459 controls were included. Allelic and genotypic comparisons between cases and controls were evaluated. Overall analysis suggests a marginal association of the 4G/5G polymorphism with diabetic retinopathy (for 4G versus 5G: OR 1.13, 95%CI 1.01 to 1.26; for 4G/4G versus 5G/5G: OR 1.30, 95%CI 1.04 to 1.64; for 4G/4G versus 5G/5G + 4G/5G: OR 1.26, 95%CI 1.05 to 1.52). In subgroup analysis by ethnicity, we found an association among the Caucasian population (for 4G versus 5G: OR 1.14, 95% CI 1.00 to 1.30; for 4G/4G versus 5G/5G: OR 1.33, 95%CI 1.02 to 1.74; for 4G/4G versus 5G/5G + 4G/5G: OR 1.41, 95%CI 1.13 to 1.77). When stratified by the average duration of diabetes, patients with diabetes histories longer than 10 years have an elevated susceptibility to diabetic retinopathy than those with shorter histories (for 4G/4G versus 5G/5G: OR 1.47, 95%CI 1.08 to 2.00). We also detected a higher risk in hospital-based studies (for 4G/4G versus 5G/5G+4G/5G: OR 1.27, 95%CI 1.02 to 1.57). Conclusions The present meta-analysis suggested that 4G/5G polymorphism in the PAI-1 gene potentially increased the risk of diabetic retinopathy in type 2 diabetes and showed a discrepancy in different ethnicities. A higher susceptibility in patients with longer duration of diabetes (more than 10

Plasminogen activator inhibitor-1 4G/5G polymorphism is associated with type 2 diabetes risk

PubMed Central

Zhao, Luqian; Huang, Ping

2013-01-01

A number of studies were performed to assess the association between plasminogen activator inhibitor-1 (PAI-1) 4G/5G polymorphism and susceptibility to type 2 diabetes (T2DM). However, the results were inconsistent and inconclusive. In the present study, the possible association was investigated by a meta-analysis. Eligible articles were identified for the period up to June 2013. Pooled odds ratios (OR) with 95% confidence intervals (CI) were appropriately derived from random-effects models or fixed-effects models. Fourteen case-control studies with a total of 2487 cases and 3538 controls were eligible. In recessive model, PAI-1 4G/5G polymorphism was associated with T2DM risk (OR = 1.23; 95% CI 1.07-1.41; P = 0.004). In the subgroup analysis by ethnicity, a significant association was found among Asians (OR = 1.27; 95% CI 1.08-1.51; P = 0.005). This meta-analysis suggested that PAI-1 4G/5G polymorphism may be associated with T2DM development. PMID:24040470

Base-Displaced Intercalated Conformation of the 2-Amino-3-methylimidazo[4,5-f]quinoline N2-dG DNA Adduct Positioned at the Nonreiterated G1 in the NarI Restriction Site

PubMed Central

2016-01-01

The conformation of an N2-dG adduct arising from the heterocyclic amine 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), a potent food mutagen, was determined in 5′-d(C1T2C3X4G5C6G7C8C9A10T11C12)-3′:5′-d(G13A14T15G16G17C18G19C20C21G22A23G24)-3′; X = N2-dG-IQ, in which the modified nucleotide X4 corresponds to G1 in the 5′-d(G1G2CG3CC)-3′ NarI restriction endonuclease site. Circular dichroism (CD) revealed blue shifts relative to the unmodified duplex, consistent with adduct-induced twisting, and a hypochromic effect for the IQ absorbance in the near UV region. NMR revealed that the N2-dG-IQ adduct adopted a base-displaced intercalated conformation in which the modified guanine remained in the anti conformation about the glycosidic bond, the IQ moiety intercalated into the duplex, and the complementary base C21 was displaced into the major groove. The processing of the N2-dG-IQ lesion by hpol η is sequence-dependent; when placed at the reiterated G3 position, but not at the G1 position, this lesion exhibits a propensity for frameshift replication [Choi, J. Y., et al. (2006) J. Biol. Chem., 281, 25297–25306]. The structure of the N2-dG-IQ adduct at the nonreiterated G1 position was compared to that of the same adduct placed at the G3 position [Stavros, K. M., et al. (2014) Nucleic Acids Res., 42, 3450–3463]. CD indicted minimal spectral differences between the G1 vs G3N2-dG-IQ adducts. NMR indicated that the N2-dG-IQ adduct exhibited similar base-displaced intercalated conformations at both the G1 and G3 positions. This result differed as compared to the corresponding C8-dG-IQ adducts placed at the same positions. The C8-dG-IQ adduct adopted a minor groove conformation when placed at position G1 but a base-displaced intercalated conformation when placed at position G3 in the NarI sequence. The present studies suggest that differences in lesion bypass by hpol η may be mediated by differences in the 3′-flanking sequences, perhaps modulating the ability

3-(3-Hydroxy-4-methoxyphenyl)-4-(3,4,5-trimethoxyphenyl)-1,2,5-selenadiazole (G-1103), a novel combretastatin A-4 analog, induces G2/M arrest and apoptosis by disrupting tubulin polymerization in human cervical HeLa cells and fibrosarcoma HT-1080 cells.

PubMed

Zuo, Daiying; Guo, Dandan; Jiang, Xuewei; Guan, Qi; Qi, Huan; Xu, Jingwen; Li, Zengqiang; Yang, Fushan; Zhang, Weige; Wu, Yingliang

2015-02-05

Microtubule is a popular target for anticancer drugs. In this study, we describe the effect 3-(3-hydroxy-4-methoxyphenyl)-4-(3,4,5-trimethoxyphenyl)-1,2,5-selenadiazole (G-1103), a newly synthesized analog of combretastatin A-4 (CA-4), showing a strong time- and dose-dependent anti-proliferative effect on human cervical cancer HeLa cells and human fibrosarcoma HT-1080 cells. We demonstrated that the growth inhibitory effects of G-1103 in HeLa and HT-1080 cells were associated with microtubule depolymerization and proved that G-1103 acted as microtubule destabilizing agent. Furthermore, cell cycle analysis revealed that G-1103 treatment resulted in cell cycle arrest at the G2/M phase in a time-dependent manner with subsequent apoptosis induction. Western blot analysis revealed that down-regulation of cdc25c and up-regulation of cyclin B1 was related with G2/M arrest in HeLa and HT-1080 cells treatment with G-1103. In addition, G-1103 induced HeLa cell apoptosis by up-regulating cleaved caspase-3, Fas, cleaved caspase-8 expression, which indicated that G-1103 induced HeLa cell apoptosis was mainly associated with death receptor pathway. However, G-1103 induced HT-1080 cell apoptosis by up-regulating cleaved caspase-3, Fas, cleaved caspase-8, Bax and cleaved caspase-9 expression and down-regulating anti-apoptotic protein Bcl-2 expression, which indicated that G-1103 induced HT-1080 cell apoptosis was associated with both mitochondrial and death receptor pathway. Taken together, all the data demonstrated that G-1103 exhibited its antitumor activity through disrupting the microtubule assembly, causing cell cycle arrest and consequently inducing apoptosis in HeLa and HT-1080 cells. Therefore, the novel compound G-1103 is a promising microtubule inhibitor that has great potentials for therapeutic treatment of various malignancies. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Human rotavirus strains circulating in Venezuela after vaccine introduction: predominance of G2P[4] and reemergence of G1P[8].

PubMed

Vizzi, Esmeralda; Piñeros, Oscar A; Oropeza, M Daniela; Naranjo, Laura; Suárez, José A; Fernández, Rixio; Zambrano, José L; Celis, Argelia; Liprandi, Ferdinando

2017-03-21

Rotavirus (RV) is the most common cause of severe childhood diarrhea worldwide. Despite Venezuela was among the first developing countries to introduce RV vaccines into their national immunization schedules, RV is still contributing to the burden of diarrhea. Concerns exist about the selective pressure that RV vaccines could exert on the predominant types and/or emergence of new strains. To assess the impact of RV vaccines on the genotype distribution 1 year after the vaccination was implemented, a total of 912 fecal specimens, collected from children with acute gastroenteritis in Caracas from February 2007 to April 2008, were screened, of which 169 (18.5%) were confirmed to be RV positive by PAGE. Rotavirus-associated diarrhea occurred all year-round, although prevailed during the coolest and driest months among unvaccinated children under 24 months old. Of 165 RV strains genotyped for G (VP7) and P (VP4) by seminested multiplex RT-PCR, 77 (46.7%) were G2P[4] and 63 (38.2%) G1P[8]. G9P[8], G3P[8] and G2P[6] were found in a lower proportion (7.3%). Remarkable was also the detection of <5% of uncommon combinations (G8P[14], G8P[4], G1P[4] and G4P[4]) and 3.6% of mixed infections. A changing pattern of G/P-type distribution was observed during the season studied, with complete predominance of G2P[4] from February to June 2007 followed by its gradual decline and the reemergence of G1P[8], predominant since January 2008. Phylogenetic analysis of VP7 and VP4 genes revealed a high similarity among G2P[4] and global strains belonging to G2-II and P[4]-V lineages. The amino acid substitution 96D → N, related with reemergence of the G2 genotype elsewhere, was observed. The G1P[8] strains from Caracas were grouped into the lineages G1-I and P[8]-III, along with geographically remote G1P[8] rotaviruses, but they were rather distant from Rotarix ® vaccine and pre-vaccine strains. Unique amino acid substitutions observed on neutralization domains of the VP7 sequence from

Insights into the photocatalytic mechanism of mediator-free direct Z-scheme g-C3N4/Bi2MoO6(010) and g-C3N4/Bi2WO6(010) heterostructures: A hybrid density functional theory study

NASA Astrophysics Data System (ADS)

Opoku, Francis; Govender, Krishna Kuben; Sittert, Cornelia Gertina Catharina Elizabeth van; Govender, Penny Poomani

2018-01-01

Graphite-like carbon nitride (g-C3N4)-based heterostructures have received much attention due to their prominent photocatalytic activity. The g-C3N4/Bi2WO6 and g-C3N4/Bi2MoO6 heterostructures, which follow a typical hetero-junction charge transfer mechanisms show a weak potential for hydrogen evolution and reactive radical generation under visible light irradiation. A mediator-free Z-scheme g-C3N4/Bi2MoO6(010) and g-C3N4/Bi2WO6(010) heterostructures photocatalyst are designed for the first time using first-principles studies. Moreover, theoretical understanding of the underlying mechanism, the effects of interfacial composition and the role the interface play in the overall photoactivity is still unexplained. The calculated band gap of the heterostructures is reduced compared to the bulk Bi2WO6 and Bi2MoO6. In this study, we systematically calculated energy band structure, optical properties and charge transfer of the g-C3N4/Bi2MoO6(010) and g-C3N4/Bi2WO6(010) heterostructures using the hybrid density functional theory approach. The results show that the charge transfer at the interface of the heterostructures induces a built-in potential, which benefits the separation of photogenerated charge carriers. The g-C3N4/Bi2MoO6(010) heterostructure with more negative adhesion energy (-1.10 eVA-2) is predicted to have a better adsorptive ability and can form more easily compared to the g-C3N4/Bi2WO6(010) interface (-1.16 eVA-2). Therefore, our results show that the g-C3N4 interaction with Bi2MoO6 is stronger than Bi2WO6, which is also verified by the smaller vertical separation (3.25 Å) between Bi2MoO6 and g-C3N4 compared to the g-C3N4/Bi2WO6(010) interface (3.36 Å). The optical absorption verifies that these proposed Z-scheme heterostructures are excellent visible light harvesting semiconductor photocatalyst materials. This enhancement is ascribed to the role of g-C3N4 monolayer as an electron acceptor and the direct Z-scheme charge carrier transfer at the interface of

Reactions of small negative ions with O2(a 1[Delta]g) and O2(X 3[Sigma]g-)

NASA Astrophysics Data System (ADS)

Midey, Anthony; Dotan, Itzhak; Seeley, J. V.; Viggiano, A. A.

2009-02-01

The rate constants and product ion branching ratios were measured for the reactions of various small negative ions with O2(X 3[Sigma]g-) and O2(a 1[Delta]g) in a selected ion flow tube (SIFT). Only NH2- and CH3O- were found to react with O2(X) and both reactions were slow. CH3O- reacted by hydride transfer, both with and without electron detachment. NH2- formed both OH-, as observed previously, and O2-, the latter via endothermic charge transfer. A temperature study revealed a negative temperature dependence for the former channel and Arrhenius behavior for the endothermic channel, resulting in an overall rate constant with a minimum at 500 K. SF6-, SF4-, SO3- and CO3- were found to react with O2(a 1[Delta]g) with rate constants less than 10-11 cm3 s-1. NH2- reacted rapidly with O2(a 1[Delta]g) by charge transfer. The reactions of HO2- and SO2- proceeded moderately with competition between Penning detachment and charge transfer. SO2- produced a SO4- cluster product in 2% of reactions and HO2- produced O3- in 13% of the reactions. CH3O- proceeded essentially at the collision rate by hydride transfer, again both with and without electron detachment. These results show that charge transfer to O2(a 1[Delta]g) occurs readily if the there are no restrictions on the ion beyond the reaction thermodynamics. The SO2- and HO2- reactions with O2(a) are the only known reactions involving Penning detachment besides the reaction with O2- studied previously [R.S. Berry, Phys. Chem. Chem. Phys., 7 (2005) 289-290].

Magnetically Separable Fe2O3/g-C3N4 Nanocomposites with Cocoon-Like Shape: Magnetic Properties and Photocatalytic Activities

NASA Astrophysics Data System (ADS)

Yu, Xiaojia; Yang, Xiaoyu; Li, Guang

2018-01-01

We report magnetically separable Fe2O3/g-C3N4 nanocomposites as a photocatalyst under visible-light irradiation in this study. The Fe2O3/g-C3N4 nanocomposites were synthesized through a two-step hydrothermal method. The Fe2O3 with cocoon-like shape was obviously dispersed on the surface of g-C3N4 with porous and layered nanostructure as seen from micrographs of the particles. Furthermore, the magnetic conversion of the samples was studied via vibrating sample magnetometer technology. It was found that the saturated magnetization Ms of the Fe2O3/g-C3N4 nanoparticles obviously decreased in the presence of g-C3N4, and the photocatalytic activity of the samples investigated by degrading Rhodamine B suggested that the Fe2O3/g-C3N4 photocatalyst was prior to the pure Fe2O3 and g-C3N4 samples. In addition, the magnetically separable ability of Fe2O3/g-C3N4 nanocomposites was efficiently exhibited by an external magnet.

Prothrombin polymorphism A19911G, factor V HR2 haplotype A4070G, and plasminogen activator-inhibitor-1 polymorphism 4G/5G and the risk of retinal vein occlusion.

PubMed

Kuhli-Hattenbach, Claudia; Hellstern, Peter; Nägler, Dorit Karin; Kohnen, Thomas; Hattenbach, Lars-Olof

2017-01-01

Thus far, no data has become available to evaluate systematically the prevalences of prothrombin polymorphism A19911G (PT A19911G), factor V HR2 haplotype A4070G (FV A4070G), or plasminogen activator-inhibitor-1 polymorphism 4G/5G (PAI-1 4G/5G) in patients who develop retinal vein occlusion (RVO) without cardiovascular risk factors. We retrospectively evaluated comprehensive thrombophilia data from 42 preselected RVO patients without cardiovascular risk factors. The prevalences of different gene mutations and polymorphisms including factor V Leiden mutation G1691A (FVL), FV A4070G, prothrombin mutation G20210A, PT A19911G, and PAI-1 4G/5G were compared with 241 healthy controls matched for age and sex. A total of 20 patients (47.7%) were found to carry thrombophilic gene polymorphisms including FVL, FV A4070G, and homozygous PT A19911G compared with 72 of 241 controls (29.9%; p = 0.03). Subgroup analysis of patients with a significant personal or family history of thromboembolism revealed a high prevalence of FVL, FV A4070G, and homozygous PT A19911G (p = 0.005). FV A4070G was found to be significantly associated with at least two other heterozygous or one homozygous gene polymorphisms (p = 0.02). Multivariate analysis revealed the presence of FVL (p = 0.0017) and homozygous PT A19911G (p = 0.03) polymorphism as independent risk factors for the development of RVO. Our results indicate that in selected RVO patients screening for thrombophilic gene polymorphisms including FVL, FV A4070G and homozygous PT G19911A may be helpful in a high percentage of cases. Our findings suggest that hereditary thrombophilia associated with RVO is more likely to be multigenic than caused by any single risk factor.

Plasminogen activator inhibitor I 4G/5G polymorphism in neonatal respiratory distress syndrome.

PubMed

Armangil, Didem; Yurdakök, Murat; Okur, Hamza; Gürgey, Aytemiz

2011-08-01

Fibrin monomers inhibit surfactant function. 4G/5G insertion/deletion polymorphism plays an important role in the regulation of plasminogen activator inhibitor 1 (PAI-1) gene expression. To examine the genotype distribution of PAI-1 polymorphism in 60 infants with respiratory distress syndrome (RDS) and 53 controls, an allele-specific polymerase chain reaction (PCR) was used. The proportion of 4G/4G, 4G/5G, and 5G/5G genotypes did not differ statistically between the RDS and control groups (P > .05). Having PAI-1 4G/4G genotype polymorphism appears to increase the risk of RDS (odds ratio [OR] =1.5; 95% confidence interval [CI], 0.5-4.3), although it was not statistically significant. No relation was found between the PAI-1 4G/5G polymorphisms and RDS, but there was an increased risk associated with the 4G variant of the PAI-1 gene. We believe that our findings of increased 4G allele of the PAI-1 gene in infants with RDS would also help to clarify the pathogenesis of RDS.

78 FR 8191 - Certain Wireless Devices With 3G and/or 4G Capabilities and Components Thereof; Institution of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-05

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-868] Certain Wireless Devices With 3G and... importation, and the sale within the United States after importation of certain wireless devices with 3G and... devices with 3G and/or 4G capabilities and components thereof by reason of infringement of one or more of...

Expansion of blood IgG4+ B, TH2, and regulatory T cells in patients with IgG4-related disease.

PubMed

Heeringa, Jorn J; Karim, A Faiz; van Laar, Jan A M; Verdijk, Robert M; Paridaens, Dion; van Hagen, P Martin; van Zelm, Menno C

2018-05-01

IgG 4 -related disease (IgG 4 -RD) is a systemic fibroinflammatory condition affecting various organs and has a diverse clinical presentation. Fibrosis and accumulation of IgG 4 + plasma cells in tissue are hallmarks of the disease, and IgG 4 -RD is associated with increased IgG 4 serum levels. However, disease pathogenesis is still unclear, and these cellular and molecular parameters are neither sensitive nor specific for the diagnosis of IgG 4 -RD. Here we sought to develop a flow cytometric gating strategy to reliably identify blood IgG 4 + B cells to study their cellular and molecular characteristics and investigate their contribution in disease pathogenesis. Sixteen patients with histologically confirmed IgG 4 -RD, 11 patients with sarcoidosis, and 30 healthy subjects were included for 11-color flow cytometric analysis of peripheral blood for IgG 4 -expressing B cells and T H subsets. In addition, detailed analysis of activation markers and chemokine receptors was performed on IgG 4 -expressing B cells, and IgG 4 transcripts were analyzed for somatic hypermutations. Cellular and molecular analyses revealed increased numbers of blood IgG 4 + memory B cells in patients with IgG 4 -RD. These cells showed reduced expression of CD27 and CXCR5 and increased signs of antibody maturation. Furthermore, patients with IgG 4 -RD, but not patients with sarcoidosis, had increased numbers of circulating plasmablasts and CD21 low B cells, as well as T H 2 and regulatory T cells, indicating a common disease pathogenesis in patients with IgG 4 -RD. These results provide new insights into the dysregulated IgG 4 response in patients with IgG 4 -RD. A specific "peripheral lymphocyte signature" observed in patients with IgG 4 -RD, could support diagnosis and treatment monitoring. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

IgG4 plasma cell myeloma: new insights into the pathogenesis of IgG4-related disease.

PubMed

Geyer, Julia T; Niesvizky, Ruben; Jayabalan, David S; Mathew, Susan; Subramaniyam, Shivakumar; Geyer, Alexander I; Orazi, Attilio; Ely, Scott A

2014-03-01

IgG4-related disease is a newly described systemic fibroinflammatory process, characterized by increase in IgG4-positive plasma cells. Its pathogenesis, including the role of IgG4, remains poorly understood. Plasma cell myeloma is typically associated with a large monoclonal serum spike, which is frequently of IgG isotype. We sought to identify and characterize a subset of IgG4-secreting myeloma, as it may provide a biological model of disease with high serum levels of IgG4. Six out of 158 bone marrow biopsies (4%) from patients with IgG myeloma expressed IgG4. Four patients were men and two were women, with a mean age of 64 (range 53-87) years. Imaging showed fullness of pancreatic head (1), small non-metabolic lymphadenopathy (1), and bone lytic lesions (6). Two patients developed necrotizing fasciitis. All had elevated serum M-protein (mean 2.4, range 0.5-4.2 g/dl), and none had definite signs or symptoms of IgG4-related disease. Four myelomas had plasmablastic morphology. Four had kappa and two had lambda light chain expression. Three cases expressed CD56. Two patients had a complex karyotype. In conclusion, the frequency of IgG4 myeloma correlates with the normal distribution of IgG4 isoform. The patients with IgG4 myeloma appear to have a high rate of plasmablastic morphology and could be predisposed to necrotizing fasciitis. Despite high serum levels of IgG4, none had evidence of IgG4-related disease. These findings suggest that the increased number of IgG4-positive plasma cells is not the primary etiologic agent in IgG4-related disease. Elevated serum levels of IgG4 is not sufficient to produce the typical disease presentation and should not be considered diagnostic of IgG4-related disease.

Plasminogen activator inhibitor 1 4G/5G and -844G/A variants in idiopathic recurrent pregnancy loss.

PubMed

Magdoud, Kalthoum; Herbepin, Viviana G; Touraine, Renaud; Almawi, Wassim Y; Mahjoub, Touhami

2013-09-01

Plasminogen activator inhibitor type 1 (PAI-1) regulates fibrinolysis, and the common promoter region variants -675G/A (4G/5G) and -844G/A are associated with increased thrombotic risk. Despite evidence linking altered fibrinolysis with adverse pregnancy events, including idiopathic recurrent pregnancy loss (RPL), the contribution of PAI-1 variants to RPL risk remains controversial. We investigated the association between the PAI-1 -844G/A and 4G/5G (-675G/A) variants with altered risk of RPL. This was a case-control study involving 304 women with confirmed RPL and 371 age- and ethnically matched control women. PAI-1 genotyping was performed by PCR single-specific primer -675 (G/A) and real-time PCR (-844G/A) analysis. Minor allele frequency (MAF) of 4G/5G (P < 0.001), but not -844G/A (P = 0.507), was higher in RPL cases. PAI-1 4G/5G single-nucleotide polymorphism (SNP) was significantly associated with RPL under additive, dominant, and recessive genetic models; no association of -844G/A with RPL was seen irrespective of the genetic model tested. Taking common -844G/5G haplotype as reference (OR = 1.00), multivariate analysis confirmed the association of 4G-containing -844A/4G (P < 0.001) and -844G/4G (P = 0.011) haplotypes with increased RPL risk. 4G/5G, but not -844G/A, PAI-1 variant is associated with an increased risk of RPL. © 2013 John Wiley & Sons Ltd.

Effects of 2G and 3G mobile phones on performance and electrophysiology in adolescents, young adults and older adults.

PubMed

Leung, S; Croft, R J; McKenzie, R J; Iskra, S; Silber, B; Cooper, N R; O'Neill, B; Cropley, V; Diaz-Trujillo, A; Hamblin, D; Simpson, D

2011-11-01

This study examined sensory and cognitive processing in adolescents, young adults and older adults, when exposed to 2nd (2G) and 3rd (3G) generation mobile phone signals. Tests employed were the auditory 3-stimulus oddball and the N-back. Forty-one 13-15 year olds, forty-two 19-40 year olds and twenty 55-70 year olds were tested using a double-blind cross-over design, where each participant received Sham, 2G and 3G exposures, separated by at least 4 days. 3-Stimulus oddball task: Behavioural: accuracy and reaction time of responses to targets were not affected by exposure. Electrophysiological: augmented N1 was found in the 2G condition (independent of age group). N-back task: Behavioural: the combined groups performed less accurately during the 3G exposure (compared to Sham), with post hoc tests finding this effect separately in the adolescents only. Electrophysiological: delayed ERD/ERS responses of the alpha power were found in both 3G and 2G conditions (compared to Sham; independent of age group). Employing tasks tailored to each individual's ability level, this study provides support for an effect of acute 2G and 3G exposure on human cognitive function. The subtlety of mobile phone effect on cognition in our study suggests that it is important to account for individual differences in future mobile phone research. Copyright © 2011 International Federation of Clinical Neurophysiology. All rights reserved.

Enhanced visible light activity on direct contact Z-scheme g-C3N4-TiO2 photocatalyst

NASA Astrophysics Data System (ADS)

Li, Juan; Zhang, Min; Li, Qiuye; Yang, Jianjun

2017-01-01

Direct contact Z-scheme g-C3N4-TiO2 nanocomposites without an electron mediator are prepared via simple annealing the mixture of bulk g-C3N4 and nanotube titanic acid (NTA) in air at 600 °C for 2 h. In the process of annealing, the bulk g-C3N4 transformed to ultra-thin g-C3N4 nanosheets, and NTA converted to a novel anatase TiO2, then the two components formed a close interaction. The XPS result reveals that some amount of nitrogen is doped into this novel-TiO2, and g-C3N4 nanosheets exist in the composites. The results of XRD, TEM and TG indicate that the thickness of g-C3N4 nanosheets is very thin. The ESR spectrum shows the existence of Ti3+ and single-electron-trapped oxygen vacancy in the 30%g-C3N4-TiO2 composites. In photocatalytic activity test, the 30%g-C3N4-TiO2 nanocomposites showed an excellent photo-oxidation activity of propylene under visible light irradiation (λ≥ 420 nm), and the removal efficiency of propylene reached as high as 56.6%, and the activity kept nearly 82% after four consecutive recycles. Photoluminescence (PL) result using terephthalic acid (TA) as a probe molecule indicated that the g-C3N4-TiO2 nanocomposites displayed a Z-sheme photocatalytic reaction system and this should be the main reason for the high photocatalytic activity. A possible photocatalytic mechanism was proposed on the basis of PL result and transient photocurrent-time curves.

Association Between Plasminogen Activator Inhibitor-1-675 4G/5G Insertion/Deletion Polymorphism and Chronic Obstructive Pulmonary Disease.

PubMed

Essa, Enas S; El Wahsh, Rabab A

2016-12-01

Molecular pathology of chronic obstructive pulmonary disease (COPD) is still being investigated to discover relationships with disease pathogenesis. Evidence of plasminogen activator inhibitor-1 (PAI-1) overexpression in the sputum and the blood of COPD patients is growing. We aimed to investigate the potential relation between PAI-1 promoter 4G/5G insertion/deletion polymorphism and COPD development. In a case-control study, we genotyped 117 COPD patients and 160 control subjects for PAI-1 promoter 4G/5G polymorphism by an allele-specific polymerase chain reaction analysis. All subjects were male smokers. In the co-dominant model, there was a significant difference in the distribution of 5G/5G, 4G/5G and 4G/4G genotypes between COPD patients and controls (p = 0.002). In the recessive model, carriers of 4G/4G genotype were significantly higher in COPD patients than controls (p = 0.01). Carriers of 4G/4G genotype were at higher risk to develop COPD than those carrying 5G/5G or 4G/5G genotypes (crude odds ratio (OR) = 2.10, 95% confidence interval (CI) = 1.19-3.73, adjusted OR = 2.5, 95% CI = 1.22-3.99). In conclusion, PAI-1 4G/5G genetic variations are associated with COPD development in males.

Increase in serum concentrations of IgG2 and IgG4 by selenium supplementation in children with Down's syndrome.

PubMed Central

Annerén, G; Magnusson, C G; Nordvall, S L

1990-01-01

In a previous study on children with Down's syndrome a reduced rate of infections was reported by their parents after the children had received six months' treatment with selenium supplements. In the present study the concentrations of the four IgG subclasses were measured in 29 of these children in samples of serum obtained before and immediately after the period of supplementation and one year after it had finished. Selenium had a significant augmentative effect on the serum concentrations of IgG2 and IgG4, but not of IgG1 and IgG3. This effect was not related to age, as among children over the age of 6 years the serum concentrations of IgG2 and IgG4 had decreased significantly one year after the treatment had been stopped. This study suggests that selenium has an immunoregulatory effect, which might be of importance in both basic research and clinical practice. PMID:2148668

Preparation of WO3/g-C3N4 composites and their application in oxidative desulfurization

NASA Astrophysics Data System (ADS)

Zhao, Rongxiang; Li, Xiuping; Su, Jianxun; Gao, Xiaohan

2017-01-01

WO3/graphitic carbon nitride (g-C3N4) composites were successfully synthesized through direct calcining of a mixture of WO3 and g-C3N4 at 400 °C for 2 h. The WO3 was prepared by calcination of phosphotungstic acid at 550 °C for 4 h, and the g-C3N4 was obtained by calcination of melamine at 520 °C for 4 h. The WO3/g-C3N4 composites were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), and Brunner-Emmett-Teller analysis (BET). The WO3/g-C3N4 composites exhibited stronger XRD peaks of WO3 and g-C3N4 than the WO3 and pure g-C3N4. In addition, two WO3 peaks at 25.7° and 26.6° emerged for the 36% -WO3/g-C3N4 composite. This finding indicated that WO3 was highly dispersed on the surface of the g-C3N4 nanosheets and interacted with the nanosheets, which resulted in the appearance of (012) and (022) planes of WO3. The WO3/g-C3N4 composite also exhibited a larger specific surface area and higher degree of crystallization than WO3 or pure g-C3N4, which resulted in high catalytic activity of the catalyst. Desulfurization experiments demonstrated that the desulfurization rate of dibenzothiophene (DBT) in model oil reached 91.2% under optimal conditions. Moreover, the activity of the catalyst was not significantly decreased after five recycles.

The Plasminogen Activator Inhibitor 1 4G/5G Polymorphism and the Risk of Alzheimer's Disease.

PubMed

Fekih-Mrissa, Najiba; Mansour, Malek; Sayeh, Aicha; Bedoui, Ines; Mrad, Meriem; Riahi, Anis; Mrissa, Ridha; Nsiri, Brahim

2017-09-01

The aim of this study was to determine whether plasminogen activator inhibitor 1 (PAI-1) is associated with the risk of Alzheimer's disease (AD) in Tunisian patients. We analyzed the genotype and allele frequency distribution of the PAI-1 polymorphism in 60 Tunisian patients with AD and 120 healthy controls. The results show a significantly increased risk of AD in carriers of the 4G/4G and 4G/5G genotypes versus the wild-type 5G/5G genotype (4G/4G: 28.33% in patients vs 10.0% in controls; P < 10 -3 ; OR = 8.78; 4G/5G: 55.0% in patients vs 38.33% in controls; OR = 4.45; P < 10 -3 ). The 4G allele was also more frequently found in patients compared with controls; P < 10 -3 ; OR = 3.07. For all participants and by gender, homozygotic carriers (4G/4G) were at an increased risk of AD over heterozygotes and women were at an increased risk over their male genotype counterparts. The odds ratio for AD among 4G/4G carriers for any group was approximately twice that of heterozygotes in the same group. Women homozygotes ranked highest for AD risk (OR = 20.8) and, in fact, women heterozygotes (OR = 9.03) ranked higher for risk than male homozygotes (OR = 6.12). These preliminary exploratory results should be confirmed in a larger study.

A review on g-C3N4-based photocatalysts

NASA Astrophysics Data System (ADS)

Wen, Jiuqing; Xie, Jun; Chen, Xiaobo; Li, Xin

2017-01-01

As one of the most appealing and attractive technologies, heterogeneous photocatalysis has been utilized to directly harvest, convert and store renewable solar energy for producing sustainable and green solar fuels and a broad range of environmental applications. Due to their unique physicochemical, optical and electrical properties, a wide variety of g-C3N4-based photocatalysts have been designed to drive various reduction and oxidation reactions under light irradiation with suitable wavelengths. In this review, we have systematically summarized the photocatalytic fundamentals of g-C3N4-based photocatalysts, including fundamental mechanism of heterogeneous photocatalysis, advantages, challenges and the design considerations of g-C3N4-based photocatalysts. The versatile properties of g-C3N4-based photocatalysts are highlighted, including their crystal structural, surface phisicochemical, stability, optical, adsorption, electrochemical, photoelectrochemical and electronic properties. Various design strategies are also thoroughly reviewed, including band-gap engineering, defect control, dimensionality tuning, pore texture tailoring, surface sensitization, heterojunction construction, co-catalyst and nanocarbon loading. Many important applications are also addressed, such as photocatalytic water splitting (H2 evolution and overall water splitting), degradation of pollutants, carbon dioxide reduction, selective organic transformations and disinfection. Through reviewing the important state-of-the-art advances on this topic, it may provide new opportunities for designing and constructing highly effective g-C3N4-based photocatalysts for various applications in photocatalysis and other related fields, such as solar cell, photoelectrocatalysis, electrocatalysis, lithium battery, supercapacitor, fuel cell and separation and purification.

Hashimoto's thyroiditis with elevated serum IgG4 concentrations is not equivalent to IgG4 Hashimoto's thyroiditis.

PubMed

Yu, Yang; Yu, Nan; Lu, Guizhi; Li, Ting; Zhang, Yang; Zhang, Jing; Gao, Ying; Gao, Yanming; Guo, Xiaohui

2018-06-01

Hashimoto's thyroiditis (HT) with serum IgG4 concentrations greater than 135 mg/dL can be diagnosed as elevated serum IgG4 HT. HT can also be classified into IgG4 HT and non-IgG4 HT based on an immunohistochemistry analysis of IgG4. The aim of our study was to determine the relationship between elevated serum IgG4 HT and IgG4 HT. Both thyroid tissues and serum samples stored before pathological examination from 93 patients with HT were collected. The serum levels of IgG, IgG4, TgAb IgG, TgAb IgG4, TPOAb IgG and TPOAb IgG4 were measured by ELISAs. The expression levels of IgG4, IgG and TGF-β1 in thyroid tissues were detected by immunohistochemistry. Patients with HT were divided into two groups: elevated serum IgG4 HT (n = 12) and nonelevated serum IgG4 HT (n = 81). Hypothyroidism was found in 5 of 12 cases (41.7%) in the elevated serum IgG4 HT group and 10 of 81 cases (12.3%) in the nonelevated serum IgG4 HT group (P = .023). Serologically, there were no significant differences in the levels of TgAb IgG, TPOAb IgG, TgAb IgG4 and TPOAb IgG4 between the two groups, and the expression of TGF-β1 in thyroid tissues was not significantly different between the groups. Most importantly, the frequency of patients who satisfied the criteria for IgG4 HT diagnosis was comparable (25% vs 20.9%, P = .756). The measurement of serum IgG4 allows the identification of patients with HT closely associated with hypothyroidism. However, our study demonstrated that elevated serum IgG4 HT is not equivalent to IgG4 HT. © 2018 John Wiley & Sons Ltd.

Collisional relaxation of O2(X^3Σ _g^ -, υ = 1) and O2(a1Δg, υ = 1) by atmospherically relevant species

NASA Astrophysics Data System (ADS)

Pejaković, Dušan A.; Campbell, Zachary; Kalogerakis, Konstantinos S.; Copeland, Richard A.; Slanger, Tom G.

2011-09-01

Laboratory measurements are reported of the rate coefficient for collisional removal of O2(X^3Σ _g^ -, υ = 1) by O(3P), and the rate coefficients for removal of O2(a1Δg, υ = 1) by O2, CO2, and O(3P). A two-laser method is employed, in which the pulsed output of the first laser at 285 nm photolyzes ozone to produce oxygen atoms and O2(a1Δg, υ = 1), and the output of the second laser detects O2(a1Δg, υ = 1) via resonance-enhanced multiphoton ionization. The kinetics of O2(X^3Σ _g^ -, υ = 1) + O(3P) relaxation is inferred from the temporal evolution of O2(a1Δg, υ = 1), an approach enabled by the rapid collision-induced equilibration of the O2(X^3Σ _g^ -, υ = 1) and O2(a1Δg, υ = 1) populations in the system. The measured O2(X^3Σ _g^ -, υ = 1) + O(3P) rate coefficient is (2.9 ± 0.6) × 10-12 cm3 s-1 at 295 K and (3.4 ± 0.6) × 10-12 cm3 s-1 at 240 K. These values are consistent with the previously reported result of (3.2 ± 1.0) × 10-12 cm3 s-1, which was obtained at 315 K using a different experimental approach [K. S. Kalogerakis, R. A. Copeland, and T. G. Slanger, J. Chem. Phys. 123, 194303 (2005)]. For removal of O2(a1Δg, υ = 1) by O(3P), the upper limits for the rate coefficient are 4 × 10-13 cm3 s-1 at 295 K and 6 × 10-13 cm3 s-1 at 240 K. The rate coefficient for removal of O2(a1Δg, υ = 1) by O2 is (5.6 ± 0.6) × 10-11 cm3 s-1 at 295 K and (5.9 ± 0.5) × 10-11 cm3 s-1 at 240 K. The O2(a1Δg, υ = 1) + CO2 rate coefficient is (1.5 ± 0.2) × 10-14 cm3 s-1 at 295 K and (1.2 ± 0.1) × 10-14 cm3 s-1 at 240 K. The implications of the measured rate coefficients for modeling of atmospheric emissions are discussed.

Synthesis of G-N2-(CH2)3-N2-G Trimethylene DNA interstrand cross-links

PubMed Central

Gruppi, Francesca; Salyard, Tracy L. Johnson; Rizzo, Carmelo J.

2014-01-01

The synthesis of G-N2-(CH2)3-N2-G trimethylene DNA interstrand cross-links (ICLs) in a 5′-CG-3′ and 5′-GC-3′ sequence from oligodeoxynucleotides containing N2-(3-aminopropyl)-2′-deoxyguanosine and 2-fluoro-O6-(trimethylsilylethyl)inosine is presented. Automated solid-phase DNA synthesis was used for unmodified bases and modified nucleotides were incorporated via their corresponding phosphoramidite reagent by a manual coupling protocol. The preparation of the phosphoramidite reagents for incorporation of N2-(3-aminopropyl)-2′-deoxyguanosine is reported. The high-purity trimethylene DNA interstrand cross-link product is obtained through a nucleophilic aromatic substitution reaction between the N2-(3-aminopropyl)-2′-deoxyguanosine and 2-fluoro-O6-(trimethylsilylethyl)inosine containing oligodeoxynucleotides. PMID:25431636

Plasminogen activator inhibitor-1 4G/5G polymorphism in infertile women with and without endometriosis.

PubMed

Gonçalves-Filho, Rubens P; Brandes, Ariel; Christofolini, Denise M; Lerner, Tatiana G; Bianco, Bianca; Barbosa, Caio P

2011-05-01

To evaluate PAI-1 genotypes in a group of infertile women with or without endometriosis and control subjects. Case-control study. Human Reproduction Center of Medicina do ABC Faculty. One hundred and forty infertile women with endometriosis, 64 women with idiopathic infertility and 148 fertile women as control subjects. The PAI-1 4G/5G polymorphism was identified by restriction fragment length polymorphism-polymerase chain reaction. Genotype distribution and allele frequency of the 4G/5G polymorphism of the PAI-1 gene. The frequencies of genotypes 4G/4G, 4G/5G and 5G/5G of the PAI-1 gene in the infertile women with endometriosis were 38.6, 37.1 and 24.3%, respectively, and in the control group 24.3, 33.8 and 41.9%, respectively (p=0.003). When the infertile women with endometriosis were divided according to their endometriosis stage, genotypes 4G/4G, 4G/5G and 5G/5G were identified, respectively, in 36.7, 32.9 and 30.4% of the patients with minimal/mild endometriosis (p=0.102) and in 41.0, 42.6 and 16.4% of the patients with moderate/severe endometriosis (p=0.001); in the women with idiopathic infertility, these genotypes were found at a frequency of 29.7, 34.3 and 36%, respectively (p=0.637). The data suggest that, in Brazilian women, the PAI-1 4G/5G polymorphism may be associated with a risk of endometriosis-associated infertility. © 2011 The Authors Acta Obstetricia et Gynecologica Scandinavica© 2011 Nordic Federation of Societies of Obstetrics and Gynecology.

Serum levels of IgG and IgG4 in Hashimoto thyroiditis.

PubMed

Kawashima, Sachiko-Tsukamoto; Tagami, Tetsuya; Nakao, Kanako; Nanba, Kazutaka; Tamanaha, Tamiko; Usui, Takeshi; Naruse, Mitsuhide; Minamiguchi, Sachiko; Mori, Yusuke; Tsuji, Jun; Tanaka, Issei; Shimatsu, Akira

2014-03-01

Although IgG4-related disease is characterized by extensive infiltration of IgG4-positive plasma cells and lymphocytes of various organs, the details of this systemic disease are still unclear. We screened serum total IgG levels in the patients with Hashimoto thyroiditis (HT) to illustrate the prevalence of IgG4-related thyroiditis in HT. Twenty-four of 94 patients with HT (25.5%) had elevated serum IgG levels and their serum IgG4 was measured. Five of the 24 cases had more than 135 mg/dL of IgG4, which is the serum criterion of IgG4-related disease. One was a female patient who was initially treated as Graves' disease and rapidly developed a firm goiter and hypothyroidism. The biopsy of her thyroid gland revealed that follicular cells were atrophic with squamous metaplasia, replaced with fibrosis, which was compatible with the fibrous variant of HT. Immunohistochemical examination revealed diffuse infiltration of IgG4-positive plasma cells, and the serum IgG4 level was 179 mg/dL. The levels of IgG and IgG4 were positively correlated with the titers of anti-thyroglobulin antibody or anti-thyroid peroxidase antibody. In conclusion, at least a small portion of patients with HT with high titers of anti-thyroid antibodies may overlap the IgG4-related thyroiditis.

4G/5G polymorphism modulates PAI-1 circulating levels in obese women.

PubMed

Fernandes, Karla S; Sandrim, Valéria C

2012-05-01

The increase in plasminogen activator inhibitor type 1 (PAI-1) has been described as a risk factor to thrombosis-related diseases. In addition, it has been demonstrated that the variant 4G of polymorphism 4G/5G located in promoter region of PAI-1 gene is associated with higher PAI-1 levels. We investigate the role of this polymorphism on circulating PAI-1 concentration in a population of 57 obese women (23%, 4G/4G; 49%, 4G/5G and 28%, 5G/5G genotypes). Our results demonstrate a genotype-specific modulation on PAI-1 levels in obese women, thus 5G/5G genotype presented significantly lower levels of plasma PAI-1 when compared to 4G/4G group (46 ± 19 ng/mL vs. 63 ± 13 ng/mL, respectively). Our findings indicate that obese carriers of 4G/4G genotype may have increased risk to develop thrombotic diseases.

Eukaryotic Initiation Factor eIFiso4G1 and eIFiso4G2 Are Isoforms Exhibiting Distinct Functional Differences in Supporting Translation in Arabidopsis*

PubMed Central

Gallie, Daniel R.

2016-01-01

The eukaryotic translation initiation factor (eIF) 4G is required during protein synthesis to promote the assembly of several factors involved in the recruitment of a 40S ribosomal subunit to an mRNA. Although many eukaryotes express two eIF4G isoforms that are highly similar, the eIF4G isoforms in plants, referred to as eIF4G and eIFiso4G, are highly divergent in size, sequence, and domain organization but both can interact with eIF4A, eIF4B, eIF4E isoforms, and the poly(A)-binding protein. Nevertheless, eIF4G and eIFiso4G from wheat exhibit preferences in the mRNAs they translate optimally. For example, mRNA containing the 5′-leader (called Ω) of tobacco mosaic virus preferentially uses eIF4G in wheat germ lysate. In this study, the eIF4G isoform specificity of Ω was used to examine functional differences of the eIF4G isoforms in Arabidopsis. As in wheat, Ω-mediated translation was reduced in an eif4g null mutant. Loss of the eIFiso4G1 isoform, which is similar in sequence to wheat eIFiso4G, did not substantially affect Ω-mediated translation. However, loss of the eIFiso4G2 isoform substantially reduced Ω-mediated translation. eIFiso4G2 is substantially divergent from eIFiso4G1 and is present only in the Brassicaceae, suggesting a recent evolution. eIFiso4G2 isoforms exhibit sequence-specific differences in regions representing partner protein and RNA binding sites. Loss of any eIF4G isoform also resulted in a substantial reduction in reporter transcript level. These results suggest that eIFiso4G2 appeared late in plant evolution and exhibits more functional similarity with eIF4G than with eIFiso4G1 during Ω-mediated translation. PMID:26578519

[IgG4 immunohistochemistry in Riedle thyroiditis].

PubMed

Wang, S; Luo, Y F; Cao, J L; Zhang, H; Shi, X H; Liang, Z Y; Feng, R E

2017-03-08

Objective: To observe the histopathological changes and immunohistochemical expression of IgG4 in Riedle thyroiditis (RT) and to study the relationship between RT and IgG4-related diseases (IgG4-RD). Methods: A total of 5 RT patients were collected from the Department of Pathology, Peking Union Medical College Hospital during April 2012 to August 2014. The clinical and immunohistochemical features were analyzed in the 5 patients. Histopathologic analysis was performed on hematoxylin and eosin-stained sections. Results: There were one male and four female patients, aged 52 to 78 years (median 59 years). Five cases were characterized by multiple nodules of thyroid, which increased year by year. All patients were found to have surrounding tissue compression symptoms and signs. Two female patients were found to have hypothyroidism. The serum concentration of IgG was elevated in 2 cases, and the serum concentration of IgG was not tested before operation in the remaining patients. By ultrasound, all presented as low echo or medium low echo. Strong echo occasionally appeared in hypoechoic nodules. Microscopically, fibrous tissue hyperplasia was infiltrated with varying numbers of lymphocytes and plasma cells. The occlusion of phlebitis was found in 4 cases and eosinophils were found in 3 cases. IgG4 counts and IgG4/IgG ratios in 5 cases were 20/HPF, 16%; 60/HPF, 82%; 22/HPF, 28%; 400/HPF, 266% and 33/HPF, 71%, respectively. Conclusions: With the similar pathological manifestations between RT and IgG4-RD, immunohistochemical staining shows that the number of IgG4 positive plasma cells and IgG4/IgG ratio of RT are increased in varying degrees. Some cases meet the diagnostic criteria of IgG4-RD, and speculate that some cases of RT belong to IgG4-RD.

Impacts, Effectiveness and Regional Inequalities of the GeoMIP G1 to G4 Solar Radiation Management Scenarios

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Xiaoyong; Moore, John; Cui, Xuefeng

We evaluate the regional effectiveness of solar radiation management (SRM) to compensate for simultaneous changes in temperature and precipitation induced by increased greenhouse gas concentrations. We analyze results from multiple earth system models under four Geoengineering Model Intercomparison Project(GeoMIP) experiments with a modified form of the Residual Climate Response approach. Under the solar dimming geoengineering experiments G1(4xCO2) and G2(increasing CO2 by 1% per year), global average temperature is successfully restored to pre-industrial level over 50 years simulations. However, these two SRM experiments also produce a robust global precipitation decrease. The stratospheric aerosol GeoMIP geoengineering experiment, G4 has significantly greater regionalmore » inequality and lower effectiveness for compensating temperature change than G1 and G2. G4 also has significantly larger regional inequality for compensating precipitation change than G1and G2. However, there is no significant difference between precipitation change compensation effectiveness of G4 and G2, though there is much larger across model variability in G4 results. G3 has significant greater regional inequality for compensating temperature change than G1 and G2, and has significant lower effectiveness than G1. The effectiveness of four SRMs to compensate for temperature change is much higher than for precipitation. The large cross-model variation in adjustment percentage of compensated SAT and precipitation change by SRM to achieve optimal compensation effectiveness shed a light on the uncertainty accumulation effect in optimizing compensation effectiveness of SRM.« less

One-step electrospinning synthesis of TiO2/g-C3N4 nanofibers with enhanced photocatalytic properties

NASA Astrophysics Data System (ADS)

Tang, Qian; Meng, Xianfeng; Wang, Zhiying; Zhou, Jianwei; Tang, Hua

2018-02-01

TiO2/g-C3N4 composite nanofibers have been successfully synthesized by one-step electrospinning method, using titanium (IV) n-butoxide (TNBT) and urea as raw materials. The structure and compositions of TiO2/g-C3N4 samples are characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Diffuse reflectance spectroscopy (DRS), Scanning electron microscopy (SEM), Transmission electron microscope (TEM), X-ray photoelectron spectrometer (XPS) and Brunauer-Emmett-Teller (BET), respectively. The results show that the porous uniform TiO2/g-C3N4 composite nanofibers, with diameter of 100-150 nm, can be successfully prepared through electrospinning method combining 550 °C calcination process. The photocatalytic activity is evaluated by the degradation of rhodamine B (RhB) under simulated solar light. The enhanced catalytic activity is attributed predominantly to the heterojunction between TiO2 and g-C3N4, which promotes the transferring of carriers and prohibits their recombination. With the optimal doping amount of 0.6 g urea (corresponding to 3 g TNBT), the TiO2/g-C3N4 composite nanofibers exhibit the highest rate towards the photocatalytic degradation of RhB. A diagram is presented to explicate the mechanism of the whole catalytic experiment. This study might provide a promising future of applying green catalysts to solving water pollution problems.

Isoelectric point and adsorption activity of porous g-C3N4

NASA Astrophysics Data System (ADS)

Zhu, Bicheng; Xia, Pengfei; Ho, Wingkei; Yu, Jiaguo

2015-07-01

The isoelectric point (IEP) is an important physicochemical parameter of many compounds, such as oxides, hydroxides, and nitrides, and can contribute to estimation of the surface charges of compound particles at various pH conditions. In this work, three types of graphitic carbon nitrides (g-C3N4) were synthesized by directly heating melamine, thiourea, and urea. The prepared samples showed different microstructures and IEPs that influenced their adsorption activity. Differences in microstructure resulted from the various precursors used during synthesis. The IEPs of the obtained g-C3N4 were measured to be approximately 4-5, which is due to the equilibrium of chemical reactions between hydrogen ions, hydroxyl ions, and amine groups on the g-C3N4 surface. The IEP of g-C3N4 prepared from thiourea was lower than those of the corresponding samples prepared from melamine and urea. The adsorption activity of methylene blue on g-C3N4 prepared from urea and thiourea was excellent, which indicates that g-C3N4 is a promising adsorbent. This work provides a useful reference for choosing precursors with which to prepare g-C3N4 and combining g-C3N4 with other compounds in solution.

Seizures and Encephalitis in Myelin Oligodendrocyte Glycoprotein IgG Disease vs Aquaporin 4 IgG Disease.

PubMed

Hamid, Shahd H M; Whittam, Dan; Saviour, Mariyam; Alorainy, Amal; Mutch, Kerry; Linaker, Samantha; Solomon, Tom; Bhojak, Maneesh; Woodhall, Mark; Waters, Patrick; Appleton, Richard; Duddy, Martin; Jacob, Anu

2018-01-01

Antibodies to myelin oligodendrocyte glycoprotein IgG (MOG-IgG) are increasingly detected in patients with non-multiple sclerosis-related demyelination, some of whom manifest a neuromyelitis optica (NMO) phenotype. Cortical involvement, encephalopathy, and seizures are rare in aquaporin 4 antibody (AQP4-IgG)-related NMO in the white European population. However, the authors encountered several patients with seizures associated with MOG-IgG disease. To compare incidence of seizures and encephalitis-like presentation, or both between AQP4-IgG-positive and MOG-IgG-positive patients. Retrospective case series of all patients who were seropositive for MOG-IgG (n = 34) and the last 100 patients with AQP4-IgG disease (NMO spectrum disorder) seen in the NMO service between January 2013 and December 2016, and analysis was completed January 4, 2017. All patients were seen in a tertiary neurological center, The Walton Centre NHS Foundation Trust in Liverpool, England. The difference in seizure frequency between the AQP4-IgG-positive and MOG-IgG-positive patient groups was determined. Thirty-four patients with MOG-IgG disease (20 female) with a median age at analysis of 30.5 years (interquartile range [IQR], 15-69 years), and 100 AQP4-IgG-positive patients (86 female) with a median age at analysis of 54 years (IQR, 12-91 years) were studied. Most patients were of white race. Five of the 34 patients with MOG-IgG (14.7%) had seizures compared with 1 patient with AQP4-IgG (2-sided P < .008, Fisher test). On magnetic resonance imaging, all 5 MOG-IgG-positive patients had inflammatory cortical brain lesions associated with the seizures. In 3 of the 5 MOG-IgG-positive patients, seizures occurred as part of the index event. Four of the 5 presented with encephalopathy and seizures, and disease relapsed in all 5 patients. Four of these patients were receiving immunosuppressant medication at last follow-up, and 3 continued to take antiepileptic medication. In contrast, the only

G4CEP: A G4 theory modification by including pseudopotential for molecules containing first-, second- and third-row representative elements.

PubMed

Silva, Cleuton de Souza; Pereira, Douglas Henrique; Custodio, Rogério

2016-05-28

The G4CEP composite method was developed from the respective G4 all-electron version by considering the implementation of compact effective pseudopotential (CEP). The G3/05 test set was used as reference to benchmark the adaptation by treating in this work atoms and compounds from the first and second periods of the periodic table, as well as representative elements of the third period, comprising 440 thermochemical data. G4CEP has not reached a so high level of accuracy as the G4 all-electron theory. G4CEP presented a mean absolute error around 1.09 kcal mol(-1), while the original method presents a deviation corresponding to 0.83 kcal mol(-1). The similarity of the optimized molecular geometries between G4 and G4CEP indicates that the core-electron effects and basis set adjustments may be pointed out as a significant factor responsible for the large discrepancies between the pseudopotential results and the experimental data, or even that the all-electron calculations are more efficient either in its formulation or in the cancellation of errors. When the G4CEP mean absolute error (1.09 kcal mol(-1)) is compared to 1.29 kcal mol(-1) from G3CEP, it does not seem so efficient. However, while the G3CEP uncertainty is ±4.06 kcal mol(-1), the G4CEP deviation is ±2.72 kcal mol(-1). Therefore, the G4CEP theory is considerably more reliable than any previous combination of composite theory and pseudopotential, particularly for enthalpies of formation and electron affinities.

Towards G2G: Systems of Technology Database Systems

NASA Technical Reports Server (NTRS)

Maluf, David A.; Bell, David

2005-01-01

We present an approach and methodology for developing Government-to-Government (G2G) Systems of Technology Database Systems. G2G will deliver technologies for distributed and remote integration of technology data for internal use in analysis and planning as well as for external communications. G2G enables NASA managers, engineers, operational teams and information systems to "compose" technology roadmaps and plans by selecting, combining, extending, specializing and modifying components of technology database systems. G2G will interoperate information and knowledge that is distributed across organizational entities involved that is ideal for NASA future Exploration Enterprise. Key contributions of the G2G system will include the creation of an integrated approach to sustain effective management of technology investments that supports the ability of various technology database systems to be independently managed. The integration technology will comply with emerging open standards. Applications can thus be customized for local needs while enabling an integrated management of technology approach that serves the global needs of NASA. The G2G capabilities will use NASA s breakthrough in database "composition" and integration technology, will use and advance emerging open standards, and will use commercial information technologies to enable effective System of Technology Database systems.

IgG4 related sclerosing mastitis: expanding the morphological spectrum of IgG4 related diseases.

PubMed

Chougule, Abhijit; Bal, Amanjit; Das, Ashim; Singh, Gurpreet

2015-01-01

IgG4 related disease (IgG4RD) is a recently recognised condition characterised by mass forming lesions associated with storiform fibrosis, obliterative phlebitis, lymphoplasmacytic infiltrate rich in IgG4 positive plasma cells and elevated serum IgG4 levels. Although rare, mammary involvement has been reported as IgG4 related sclerosing mastitis, the morphological counterpart of a growing family of IgG4 related diseases. A total of 17 cases belonging to mass forming benign inflammatory breast lesions such as plasma cell mastitis, granulomatous lobular mastitis, non-specific mastitis and inflammatory pseudotumour were investigated as a possible member of IgG4 related sclerosing mastitis. Clinical, radiological, histopathological and immunohistochemistry findings were noted in all cases. Cases diagnosed as inflammatory pseudotumour showed all the histopathological features of IgG4RD along with increased number of IgG4 positive plasma cells and IgG4/IgG ratio >40%. However, only a few IgG4 positive cells were seen in plasma cell mastitis, granulomatous lobular mastitis and non-specific mastitis cases. These cases also did not fulfill the morphological criteria for the diagnosis of IgG4 related diseases. IgG4RD should be excluded in plasma cell rich lesions diagnosed on core biopsies by IgG4 immunostaining. This can avoid unnecessary surgery as IgG4 related diseases respond to simple and effective steroid treatment.

G4CEP: A G4 theory modification by including pseudopotential for molecules containing first-, second- and third-row representative elements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Silva, Cleuton de Souza; Instituto de Ciências Exatas e Tecnologia, Universidade Federal do Amazonas, Campus de Itacoatiara, 69100-021 Itacoatiara, Amazonas; Pereira, Douglas Henrique

2016-05-28

The G4CEP composite method was developed from the respective G4 all-electron version by considering the implementation of compact effective pseudopotential (CEP). The G3/05 test set was used as reference to benchmark the adaptation by treating in this work atoms and compounds from the first and second periods of the periodic table, as well as representative elements of the third period, comprising 440 thermochemical data. G4CEP has not reached a so high level of accuracy as the G4 all-electron theory. G4CEP presented a mean absolute error around 1.09 kcal mol{sup −1}, while the original method presents a deviation corresponding to 0.83more » kcal mol{sup −1}. The similarity of the optimized molecular geometries between G4 and G4CEP indicates that the core-electron effects and basis set adjustments may be pointed out as a significant factor responsible for the large discrepancies between the pseudopotential results and the experimental data, or even that the all-electron calculations are more efficient either in its formulation or in the cancellation of errors. When the G4CEP mean absolute error (1.09 kcal mol{sup −1}) is compared to 1.29 kcal mol{sup −1} from G3CEP, it does not seem so efficient. However, while the G3CEP uncertainty is ±4.06 kcal mol{sup −1}, the G4CEP deviation is ±2.72 kcal mol{sup −1}. Therefore, the G4CEP theory is considerably more reliable than any previous combination of composite theory and pseudopotential, particularly for enthalpies of formation and electron affinities.« less

Photocatalytic Properties of g-C3N4–TiO2 Heterojunctions under UV and Visible Light Conditions

PubMed Central

Fagan, Rachel; McCormack, Declan E.; Hinder, Steven J.; Pillai, Suresh C.

2016-01-01

Graphitic carbon nitride (g-C3N4) and titanium dioxide (TiO2) were chosen as a model system to investigate photocatalytic abilities of heterojunction system under UV and visible light conditions. The use of g-C3N4 has been shown to be effective in the reduction in recombination through the interaction between the two interfaces of TiO2 and g-C3N4. A simple method of preparing g-C3N4 through the pyrolysis of melamine was employed, which was then added to undoped TiO2 material to form the g-C3N4–TiO2 system. These materials were then fully characterized by X-ray diffraction (XRD), Brunauer Emmett Teller (BET), and various spectroscopic techniques including Raman, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), diffuse absorbance, and photoluminescence analysis. Photocatalysis studies were conducted using the model dye, rhodamine 6G utilizing visible and UV light irradiation. Raman spectroscopy confirmed that a composite of the materials was formed as opposed to a mixture of the two. Using XPS analysis, a shift in the nitrogen peak to that indicative of substitutional nitrogen was detected for all doped samples. This is then mirrored in the diffuse absorbance results, which show a clear decrease in band gap values for these samples, showing the effective band gap alteration achieved through this preparation process. When g-C3N4–TiO2 samples were analyzed under visible light irradiation, no significant improvement was observed compared that of pure TiO2. However, under UV light irradiation conditions, the photocatalytic ability of the doped samples exhibited an increased reactivity when compared to the undoped TiO2 (0.130 min−1), with 4% g-C3N4–TiO2 (0.187 min−1), showing a 43.9% increase in reactivity. Further doping to 8% g-C3N4–TiO2 lead to a decrease in reactivity against rhodamine 6G. BET analysis determined that the surface area of the 4% and 8% g-C3N4–TiO2 samples were very similar, with values of 29.4 and

Photo reduction of CO2 to CH4 on g-C3N4: The effect of concentrating light and pretreatment

NASA Astrophysics Data System (ADS)

Li, Dong; Fang, Xiaoxiang; Liu, Huayan; Lu, Hanfeng; Zhang, Zekai

2018-06-01

The behavior of CO2 photoreduction to CH4 on the g-C3N4 catalyst was studied in a concentrating light reactor. The g-C3N4 catalysts before and after pretreatment were characterized by FE-SEM, XRD and photoilluminance. It is found that concentrating light increases the CH4 yield on the g-C3N4 by heightening the incident light intensity, and light pretreatment has an excessive effect on the performance. Pretreated by suitable light intensity, air atmosphere and time, the CH4 yield on the g-C3N4 under concentrating light irradiation reached about 3.39 μmol.g-1.h-1, which is about 16 times of that g-C3N4 reacted at nature incident light without pretreatment. The mechanism of pretreatment is considered to be from the surface oxidation state change of the catalyst either from the oxidation of the catalyst surface or the activation of surface oxygen.

Riedel's thyroiditis association with IgG4-related disease.

PubMed

Stan, Marius N; Sonawane, Vikram; Sebo, Thomas J; Thapa, Prabin; Bahn, Rebecca S

2017-03-01

IgG4-positive (+) plasma cells have been reported in both Riedel's thyroiditis (RT) and Hashimoto's thyroiditis (HT). These cells are the hallmark of IgG4-related disease (IgG4-RD). We sought to determine whether RT is part of IgG4-RD spectrum. This was a case-control study performed at a tertiary medical centre. We included RT cases from the period 1958 to 2008 that had sufficient paraffin-embedded tissue for IgG4 immunostaining. Controls were patients with HT, age and gender matched, with similar pathology criteria. The main outcome measures were the intensity of the IgG4 staining and the clinical and histological correlates with IgG4-RD. Six pairs of RT and HT were analysed. The mean age was 44·7 years. In both groups, 5/6 cases had positive IgG4 staining. The mean number of IgG4 + cells/ HPF, normalized to the degree of inflammation, was 3·2 ± 3·0 SD (RT) vs 0·9 ± 0·7 (HT), P = 0·15, for fibrotic areas and 2·1 ± 2·3 SD vs 1·0 ± 0·8 (P = 0·39) for areas with lymphoid aggregates. We found the number of IgG4 +  cells in RT to be inversely correlated with the duration of disease (P = 0·046). Three RT cases had associated comorbidities from the IgG4-RD spectrum while none of the HT cases had such conditions. Riedel's thyroiditis is a component of IgG4-RD with the density of the IgG4 +  lymphocytic infiltrate being time dependent. In this small study, we did not identify differences in IgG4 infiltration between RT and HT, minimizing the utility of this marker in RT diagnosis. © 2016 John Wiley & Sons Ltd.

Construction of g-C3N4/CeO2/ZnO ternary photocatalysts with enhanced photocatalytic performance

NASA Astrophysics Data System (ADS)

Yuan, Yuan; Huang, Gui-Fang; Hu, Wang-Yu; Xiong, Dan-Ni; Zhou, Bing-Xin; Chang, Shengli; Huang, Wei-Qing

2017-07-01

Promoting the spatial separation of photoexcited charge carriers is of paramount significance for photocatalysis. In this work, binary g-C3N4/CeO2 nanosheets are first prepared by pyrolysis and subsequent exfoliation method, then decorated with ZnO nanoparticles to construct g-C3N4/CeO2/ZnO ternary nanocomposites with multi-heterointerfaces. Notably, the type-II staggered band alignments existing between any two of the constituents, as well as the efficient three-level transfer of electron-holes in unique g-C3N4/CeO2/ZnO ternary composites, leads to the robust separation of photoexcited charge carriers, as verified by its photocurrent increased by 8 times under visible light irradiation. The resulting g-C3N4/CeO2/ZnO ternary nanocomposites unveil appreciably increased photocatalytic activity, faster than that of pure g-C3N4, ZnO and g-C3N4/CeO2 by a factor of 11, 4.6 and 3.7, respectively, and good stability toward methylene blue (MB) degradation. The remarkably enhanced photocatalytic activity of g-C3N4/CeO2/ZnO ternary heterostructures can be interpreted in terms of lots of active sites of nanosheet shapes and the efficient charge separation owing to the resulting type-II band alignment with more than one heterointerface and the efficient three-level electron-hole transfer. A plausible mechanism is also elucidated via active species trapping experiments with various scavengers, which indicating that the photogenerated holes and •OH radicals play a crucial role in photodegradation reaction under visible light irradiation. This work suggest that the rational design and construction of type II multi-heterostructures is powerful for developing highly efficient and reusable visible-light photocatalysts for environmental purification and energy conversion.

Faster Electron Injection and More Active Sites for Efficient Photocatalytic H2 Evolution in g-C3 N4 /MoS2 Hybrid.

PubMed

Shi, Xiaowei; Fujitsuka, Mamoru; Kim, Sooyeon; Majima, Tetsuro

2018-03-01

Herein, the structural effect of MoS 2 as a cocatalyst of photocatalytic H 2 generation activity of g-C 3 N 4 under visible light irradiation is studied. By using single-particle photoluminescence (PL) and femtosecond time-resolved transient absorption spectroscopies, charge transfer kinetics between g-C 3 N 4 and two kinds of nanostructured MoS 2 (nanodot and monolayer) are systematically investigated. Single-particle PL results show the emission of g-C 3 N 4 is quenched by MoS 2 nanodots more effectively than MoS 2 monolayers. Electron injection rate and efficiency of g-C 3 N 4 /MoS 2 -nanodot hybrid are calculated to be 5.96 × 10 9 s -1 and 73.3%, respectively, from transient absorption spectral measurement, which are 4.8 times faster and 2.0 times higher than those of g-C 3 N 4 /MoS 2 -monolayer hybrid. Stronger intimate junction between MoS 2 nanodots and g-C 3 N 4 is suggested to be responsible for faster and more efficient electron injection. In addition, more unsaturated terminal sulfur atoms can serve as the active site in MoS 2 nanodot compared with MoS 2 monolayer. Therefore, g-C 3 N 4 /MoS 2 nanodot exhibits a 7.9 times higher photocatalytic activity for H 2 evolution (660 µmol g- 1 h -1 ) than g-C 3 N 4 /MoS 2 monolayer (83.8 µmol g -1 h -1 ). This work provides deep insight into charge transfer between g-C 3 N 4 and nanostructured MoS 2 cocatalysts, which can open a new avenue for more rationally designing MoS 2 -based catalysts for H 2 evolution. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

12 CFR 563g.3 - Exemptions.

Code of Federal Regulations, 2010 CFR

2010-01-01

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Observation of the spin-orbit components of the 3B 2g( 3A 2g) ground state in the system Ni 2+:MgF 2 by fluorescence line narrowing

NASA Astrophysics Data System (ADS)

Tonucci, R. J.; Jacobsen, S. M.; Yen, W. M.

1990-10-01

Using a tunable narrow-band infrared laser, we demonstrate for the first time infrared-fluorescnece line narrowing in the system Ni 2+:MgF 2. High-resolution emission spectra were obtained by pumping the lowest spin-orbit component B 3 ( 3T 2g) (orthorhombic notation with octahedral notation in parentheses) of the 3T 2g multiplet and observing the B 3( 3T 2g)→B 1, A, B 2( 3A 2g) luminescent transitions at low temperature. By tuning the narrow-band laser over the B 3( 3T 2g) band, resonant and non-resonant fluorescence were obtained which narrowed with respect to the inhomogeneously broadened profile, and additional lines were observed. The spectra can be understood in terms of a simultaneous excitation of two different subsets of Ni 2+ ions which have their B 2( 3A 2g)→B 3( 3T 2g) and A( 3A 2g)→B 3( 3T 2g) transitions in resonance with the laser. The A( 3A 2g) and B 1( 3A 2g) spin-orbit components of the ground-state multiplet lie 1.9 cm -1 and 6.5 cm -1 above the B 2( 3A 2g) ground state, respectively, at 2 K.

Enhanced visible light photocatalytic water reduction from a g-C 3N 4/SrTa 2O 6 heterojunction

DOE PAGES

Adhikari, Shiba P.; Hood, Zachary D.; Wang, Hui; ...

2017-06-02

In this paper, a new g-C 3N 4/SrTa 2O 6 heterojunction photocatalyst was designed and prepared by chimie douce (soft chemistry) method where carbon nitride (g-C 3N 4) was deposited over the metastable perovskite phase of SrTa 2O 6. The morphological study of the heterojunction using SEM and STEM revealed that g-C 3N 4 nanofibers are dispersed uniformly on the surface of SrTa 2O 6 plates leading to the intimate contact between them. The heterojunction could achieve a high and stable visible light photocatalytic H 2 generation of 137 mmol/h/mole of g-C 3N 4, which is much larger than themore » amount of hydrogen generated by one mole of pristine g-C 3N 4. Finally, a plausible mechanism for the observed enhanced photocatalytic activity for the heterojunction is proposed on the basis of effective charge separation of photogenerated electron-hole pairs, supported by band position calculations and photo-physical properties of g-C 3N 4 and SrTa 2O 6.« less

Enhanced visible light photocatalytic water reduction from a g-C 3N 4/SrTa 2O 6 heterojunction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adhikari, Shiba P.; Hood, Zachary D.; Wang, Hui

In this paper, a new g-C 3N 4/SrTa 2O 6 heterojunction photocatalyst was designed and prepared by chimie douce (soft chemistry) method where carbon nitride (g-C 3N 4) was deposited over the metastable perovskite phase of SrTa 2O 6. The morphological study of the heterojunction using SEM and STEM revealed that g-C 3N 4 nanofibers are dispersed uniformly on the surface of SrTa 2O 6 plates leading to the intimate contact between them. The heterojunction could achieve a high and stable visible light photocatalytic H 2 generation of 137 mmol/h/mole of g-C 3N 4, which is much larger than themore » amount of hydrogen generated by one mole of pristine g-C 3N 4. Finally, a plausible mechanism for the observed enhanced photocatalytic activity for the heterojunction is proposed on the basis of effective charge separation of photogenerated electron-hole pairs, supported by band position calculations and photo-physical properties of g-C 3N 4 and SrTa 2O 6.« less

Interface engineered construction of porous g-C3N4/TiO2 heterostructure for enhanced photocatalysis of organic pollutants

NASA Astrophysics Data System (ADS)

Li, Ya-Nan; Chen, Zhao-Yang; Wang, Min-Qiang; Zhang, Long-zhen; Bao, Shu-Juan

2018-05-01

A porous g-C3N4/TiO2 with hierarchical heterostructure has been successfully fabricated through a in situ assembling of small needle-like TiO2 on the surface of ultrathin g-C3N4 sheets. The ultrathin g-C3N4 sheets with carbon vacancies and rich hydroxyl groups were found to facilitate the nucleation and in situ growth of TiO2 and also to modulate the surface chemical activity of the g-C3N4/TiO2 hierarchical heterostructure. The as-designed photocatalytic heterojunction degraded Acid Orange with 82% efficiency after 10 min under simulated solar light, and possessed excellent cycle stability. Relative physical characterizations and photochemical experiments reveal that engineering the interface/surface of g-C3N4 plays a vital role in effectively constructing heterostructures of g-C3N4/TiO2, thus realizing efficient photoinduced electron-hole separation during photocatalytic process.

Adsorption of H2O, H2, O2, CO, NO, and CO2 on graphene/g-C3N4 nanocomposite investigated by density functional theory

NASA Astrophysics Data System (ADS)

Wu, Hong-Zhang; Bandaru, Sateesh; Liu, Jin; Li, Li-Li; Wang, Zhenling

2018-02-01

Motivated by the photocatalytic reactions of small molecules on g-C3N4 by these insights, we sought to explore the adsorption of H2O and CO2 molecules on the graphene side and H2O, H2, O2, CO, NO, and CO2 molecules on the g-C3N4 side of hybrid g-C3N4/graphene nanocomposite using first-principles calculations. The atomic structure and electronic properties of hybrid g-C3N4/graphene nanocomposite is explored. The adsorption of small molecules on graphene/g-C3N4 nanocomposite is thoroughly investigated. The computational studies revels that all small molecules on graphene/g-C3N4 nanocomposite are the physisorption. The adsorption characteristics of H2O and CO2 molecules on the graphene side are similar to that on graphene. The adsorption of H2O, H2, O2, CO, NO, and CO2 molecules on the g-C3N4 side always leads to a buckle structure of graphene/g-C3N4 nanocomposite. Graphene as a substrate can significantly relax the buckle degree of g-C3N4 in g-C3N4/graphene nanocomposite.

Association between PAI-1 4G/5G polymorphism and diabetic nephropathy: a meta-analysis in the Chinese population.

PubMed

Gao, Wen-Feng; Guo, Ying-Bo; Bai, Yu; Ding, Xin-Yu; Yan, Yong-Ji; Wu, Zhen-Qi

2016-09-01

Although a number of studies have been conducted on the association between plasminogen activator inhibitor-1 (PAI-1) 4G/5G polymorphism and diabetic nephropathy (DN) in Chinese population, this association remains elusive and controversial. To further assess the effects of PAI-1 4G/5G polymorphism on the risk of DN, a meta-analysis was performed in the Chinese population. Relevant studies were identified using PubMed, Springer Link, Ovid, Chinese Wanfang Data Knowledge Service Platform, Chinese National Knowledge Infrastructure, and Chinese Biology Medicine through November, 2015. Pooled odds ratios (ORs) and 95 % confidence intervals (CIs) were used to assess the strength of the associations. This meta-analysis identified nine studies, including 777 DN cases, 413 healthy controls, and 523 DM controls. In the total analyses, a significantly elevated risk of DN was associated with variants of PAI-1 4G/5G when compared with the healthy group (4G vs. 5G, OR 2.46, 95 % CI 1.45-4.16; 4G/4G vs. 5G/5G, OR 4.32, 95 % CI 1.79-10.39; 4G/4G vs. 4G/5G +5G/5G, OR 2.96, 95 % CI 1.59-5.53; 4G/4G +4G/5G vs. 5G/5G, OR 2.78, 95 % CI 1.34-5.75) and DM group (4G vs. 5G, OR 1.93, 95 % CI 1.28-2.92; 4G/4G vs. 5G/5G, OR 2.99, 95 % CI 1.44-6.21; 4G/4G vs. 4G/5G +5G/5G, OR 2.84, 95 % CI 1.77-4.54). In the subgroup analyses stratified by ethnicity and geographic areas, it revealed the significant results in Chinese Han, in North and South China. This meta-analysis showed that the PAI-1 4G/4G variant, 4G allele might be risk alleles for DN susceptibility in the Chinese population, and further studies in other ethic groups are required for definite conclusions.

[PAL-1 5G/4G polymorphism in patients with systemic lupus erythematosus].

PubMed

Savov, A; Andonova, S; Tanev, D; Robeva, R; Marincheva, Ts; Tomova, A; Kumanov, Ph; Rashkov, R; Kolarov, Zl

2014-01-01

Systemic lupus erythematosus (SLE) is a connective tissue disease affecting predominantly women that has been widely associated with obstetric complications. Inherited thrombophilias are significant risk factors for pregnancy loss, but their role in patients with SLE, and especially in those without concomitant secondary antiphospholipid syndrome (APS) has not been clarified. The aim of the present study was to study PAI-1 5G/4G polymorphism in women with lupus. A total of 103 SLE patients as well as 69 healthy volunteers were genotyped for PAI-1 5G/4G (rs1799889). No significant differences in the PAI-1 5G/4G genotype prevalence between patients and controls were found. After exclusion of the women with secondary APS, the frequency of pregnancies and spontaneous abortions, as well as the number of live births were similar in the studied patients with different PAI-1 genotype (p> 0.05). PAI-1 5G/4G polymorphism was not significantly related to any of the lupus ACR criteria or disease activity (p > 0.05), but it could influence the platelet number in the studied patients (263.52 ± 91.10 [5G/5G genotype] versus 210.12 ± 71.79 [4G/4G genotype], p = 0.023). In conclusion, our results showed that PAI-1 4G/5G polymorphism did not worsen the reproductive outcome in SLE women without secondary APS.

Black TiO2 nanobelts/g-C3N4 nanosheets Laminated Heterojunctions with Efficient Visible-Light-Driven Photocatalytic Performance

PubMed Central

Shen, Liyan; Xing, Zipeng; Zou, Jinlong; Li, Zhenzi; Wu, Xiaoyan; Zhang, Yuchi; Zhu, Qi; Yang, Shilin; Zhou, Wei

2017-01-01

Black TiO2 nanobelts/g-C3N4 nanosheets laminated heterojunctions (b-TiO2/g-C3N4) as visible-light-driven photocatalysts are fabricated through a simple hydrothermal-calcination process and an in-situ solid-state chemical reduction approach, followed by the mild thermal treatment (350 °C) in argon atmosphere. The prepared samples are evidently investigated by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, N2 adsorption, and UV-visible diffuse reflectance spectroscopy, respectively. The results show that special laminated heterojunctions are formed between black TiO2 nanobelts and g-C3N4 nanosheets, which favor the separation of photogenerated electron-hole pairs. Furthermore, the presence of Ti3+ and g-C3N4 greatly enhance the absorption of visible light. The resultant b-TiO2/g-C3N4 materials exhibit higher photocatalytic activity than that of g-C3N4, TiO2, b-TiO2 and TiO2/g-C3N4 for degradation of methyl orange (95%) and hydrogen evolution (555.8 μmol h−1 g−1) under visible light irradiation. The apparent reaction rate constant (k) of b-TiO2/g-C3N4 is ~9 times higher than that of pristine TiO2. Therefore, the high-efficient laminated heterojunction composites will have potential applications in fields of environment and energy. PMID:28165021

Imidazole modified g-C3N4 photocatalyst: Structural characterization and versatile energy applications

NASA Astrophysics Data System (ADS)

Zhang, Lu; Liu, Qianqian; Chai, Yuanyuan; Ren, Jia; Dai, Wei-Lin

2018-02-01

Novel imidazole modified g-C3N4 were firstly synthesized via a facile one-pot thermo-induced co-condensation method. Characterization results showed that imidazole modification can improve the visible light harvesting, interfacial charge transfer and separation of g-C3N4, without destroying its pristine framework structure. The as-obtained imidazole modified g-C3N4 showed remarkably enhanced and rather stable photocatalytic performance in H2 evolution, photo-degradation of water contaminants and selective photo-oxidation of benzyl alcohol, demonstrating its all-round applications as a versatile photocatalyst. The weight ratio between imidazole and urea was well tuned and the optimal photocatalytic activity was obtained, which shows CNU-I50 sample (50 mg imidazole in 15 g urea) possesses the highest hydrogen evolution rate of 2150 μmol g-1 h-1, superior to most of the previous reported g-C3N4 materials. These results suggest that those imidazole modified g-C3N4 materials are potential photocatalyst when applied to solar energy conversion, water purification and selective photosynthesis reactions.

Photo-induced CO2 reduction by CH4/H2O to fuels over Cu-modified g-C3N4 nanorods under simulated solar energy

NASA Astrophysics Data System (ADS)

Tahir, Beenish; Tahir, Muhammad; Amin, Nor Aishah Saidina

2017-10-01

Copper modified polymeric graphitic carbon nitride (Cu/g-C3N4) nanorods for photo-induced CO2 conversion with methane (CH4) and water (H2O) as reducing system under simulated solar energy has been investigated. The nanocatalysts, synthesized by pyrolysis and sonication, were characterized by XRD, FTIR, Raman analysis, XPS, SEM, N2 adsorption-desorption and PL spectroscopy. The presence of Cu2+ ions over the g-C3N4 structure inhibited charge carriers recombination process. The results indicated that photo-activity and selectivity of Cu/g-C3N4 photo-catalyst for CO2 reduction greatly dependent on the type of CO2-reduction system. CO2 was efficiently converted to CH4 and CH3OH with traces of C2H4 and C2H6 hydrocarbons in the CO2-water system. The yield of the main product, CH4 over 3 wt.% Cu/g-C3N4 was 109 μmole g-cata.-1 h-1 under visible light irradiation, significantly higher than the pure g-C3N4 catalyst (60 μmole/g.cat). In photo-induced CO2-CH4 reaction, CO and H2 were detected as the main products with smaller amount of hydrocarbons. The highest efficiency was detected over 3 wt.%Cu-loading of g-C3N4 and at optimal CH4/CO2 feed ratio of 1.0. The maximum yield of CO and H2 detected were 142 and 76 μmole g-catal.-1 h-1, respectively at selectivity 66.6% and 32.5%, respectively. Significantly enhanced CO2/CH4 reduction over Cu/g-C3N4 was attributed to its polymeric structure with efficient charge transfer property and inhibited charges recombination rate. A proposed photo-induced reaction mechanism, corroborated with the experimental data, was also deliberated.

Meta-analysis of the association between plasminogen activator inhibitor-1 4G/5G polymorphism and recurrent pregnancy loss.

PubMed

Li, Xuejiao; Liu, Yukun; Zhang, Rui; Tan, Jianping; Chen, Libin; Liu, Yinglin

2015-04-11

The association between plasminogen activator inhibitor-1 (PAI-1) 4G/5G polymorphism and recurrent pregnancy loss (RPL) risk is still contradictory. We thus performed a meta-analysis. Relevant studies were searched for in PubMed, Web of Science, Embase, and Cochrane Library. An odds ratio (OR) with a 95% confidence interval (CI) was used to assess the association between PAI-1 4G/5G polymorphism and RPL risk. A total of 22 studies with 4306 cases and 3076 controls were included in this meta-analysis. We found that PAI-1 4G/5G polymorphism was significantly associated with an increased RPL risk (OR=1.89; 95% CI 1.34-2.67; P=0.0003). In the subgroup analysis by race, PAI-1 4G/5G polymorphism was significantly associated with an increased RPL risk in Caucasians (OR=2.23; 95% CI 1.44-3.46; P=0.0003). However, no significant association was observed in Asians (OR=1.47; 95% CI 0.84-2.59; P=0.18). In conclusion, this meta-analysis suggests that PAI-1 4G/5G polymorphism might be associated with RPL development in Caucasians.

Synthesis of g-C{sub 3}N{sub 4}/Ag{sub 3}PO{sub 4} heterojunction with enhanced photocatalytic performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

He, Peizhi; Song, Limin; Zhang, Shujuan, E-mail: songlmnk@sohu.com

2014-03-01

Graphical abstract: g-C{sub 3}N{sub 4}/Ag{sub 3}PO{sub 4} heterojunction photocatalyst with visible-light response was prepared by a facile coprecipitation method. The results show that g-C{sub 3}N{sub 4}/Ag{sub 3}PO{sub 4} possesses a much higher activity for the decomposition of RhB than that of the pure Ag{sub 3}PO{sub 4} particles. The most mechanism is that g-C{sub 3}N{sub 4}/Ag{sub 3}PO{sub 4} heterojunction photocatalyst can efficiently separate the photogenerated electron–hole pairs, enhancing the photocatalytic activity of g-C{sub 3}N{sub 4}/Ag{sub 3}PO{sub 4} composites. - Highlights: • g-C{sub 3}N{sub 4}/Ag{sub 3}PO{sub 4} heterojunction showed much higher activity than that of Ag{sub 3}PO{sub 4}. • The high activitymore » could be attributed to g-C{sub 3}N{sub 4} for modifying Ag{sub 3}PO{sub 4}. • More ·OH radicals may be significant reason to improve Ag{sub 3}PO{sub 4} activity. - Abstract: g-C{sub 3}N{sub 4}/Ag{sub 3}PO{sub 4} heterojunction photocatalyst with visible-light response was prepared by a facile coprecipitation method. The photocatalysts were characterized by X-ray powder diffraction, transmission electron microscopy, UV–vis absorption spectroscopy and Fourier transform infrared spectroscopy. The photocatalytic activities of the obtained samples were tested by using Rhodamine B (RhB) as the degradation target under visible light irradiation. g-C{sub 3}N{sub 4}/Ag{sub 3}PO{sub 4} decomposed RhB more effectively than the pure Ag{sub 3}PO{sub 4} particles did, and 2 wt.% g-C{sub 3}N{sub 4} had the highest activity. Furthermore, 2 wt.% g-C{sub 3}N{sub 4}/Ag{sub 3}PO{sub 4} degraded high-concentration RhB more potently than unmodified Ag{sub 3}PO{sub 4} did, probably because g-C{sub 3}N{sub 4}/Ag{sub 3}PO{sub 4} heterojunction photocatalyst enhanced the photocatalytic activity by efficiently separating the photogenerated electron–hole pairs.« less

CO2 conversion in non-thermal plasma and plasma/g-C3N4 catalyst hybrid processes

NASA Astrophysics Data System (ADS)

Lu, Na; Sun, Danfeng; Zhang, Chuke; Jiang, Nan; Shang, Kefeng; Bao, Xiaoding; Li, Jie; Wu, Yan

2018-03-01

Carbon dioxide conversion at atmosphere pressure and low temperature has been studied in a cylindrical dielectric barrier discharge (DBD) reactor. Pure CO2 feed flows to the discharge zone and typical filamentary discharges were obtained in each half-cycle of the applied voltage. The gas temperature increased with discharge time and discharge power, which was found to affect the CO2 decomposition deeply. As the DBD reactor was cooled to ambient temperature, both the conversion of CO2 and the CO yield were enhanced. Especially the energy efficiencies changed slightly with the increase of discharge power and were much higher in cooling condition comparing to those without cooling. At a discharge power of 40 W, the energy efficiency under cooling condition was approximately six times more than that without cooling. Gas flow rate was observed to affect CO2 conversion and 0.1 L min-1 was obtained as optimum gas flow rate under cooling condition. In addition, the CO2 conversion rate in plasma/g-C3N4 catalyst hybrid system was twice times as that in plasma-alone system. In case of cooling, the existence of g-C3N4 catalyst contributed to a 47% increase of CO2 conversion compared to the sole plasma process. The maximum energy-efficiency with g-C3N4 was 0.26 mmol kJ-1 at 20 W, which increased by 157% compared to that without g-C3N4. The synergistic effect of DBD plasma with g-C3N4 on pure CO2 conversion was verified.

Effects of 2G and 3G mobile phones on human alpha rhythms: Resting EEG in adolescents, young adults, and the elderly.

PubMed

Croft, R J; Leung, S; McKenzie, R J; Loughran, S P; Iskra, S; Hamblin, D L; Cooper, N R

2010-09-01

The present study was conducted to determine whether adolescents and/or the elderly are more sensitive to mobile phone (MP)-related bioeffects than young adults, and to determine this for both 2nd generation (2G) GSM, and 3rd generation (3G) W-CDMA exposures. To test this, resting alpha activity (8-12 Hz band of the electroencephalogram) was assessed because numerous studies have now reported it to be enhanced by MP exposure. Forty-one 13-15 year olds, forty-two 19-40 year olds, and twenty 55-70 year olds were tested using a double-blind crossover design, where each participant received Sham, 2G and 3G exposures, separated by at least 4 days. Alpha activity, during exposure relative to baseline, was recorded and compared between conditions. Consistent with previous research, the young adults' alpha was greater in the 2G compared to Sham condition, however, no effect was seen in the adolescent or the elderly groups, and no effect of 3G exposures was found in any group. The results provide further support for an effect of 2G exposures on resting alpha activity in young adults, but fail to support a similar enhancement in adolescents or the elderly, or in any age group as a function of 3G exposure. 2010 Wiley-Liss, Inc.

Synthesis and biological activity of novel series of 4-methoxy, and 4,9-dimethoxy-5-substituted furo[2,3-g]-1,2,3-benzoxathiazine-7,7-dioxide derivatives

PubMed Central

El-Sawy, Eslam R.; Ebaid, Manal S.; Abo-Salem, Heba M.; El-Hallouty, Salwa; Kassem, Emad M.; Mandour, Adel H.

2013-01-01

A novel series of 4-methoxy, and 4,9-dimethoxy-5-substituted furo[2,3-g]-1,2,3-benzoxathiazine-7,7-dioxide derivatives 3a,b, 10a–g and 11a–g were prepared in good yields via the reaction of 4-methoxy (1a) and 4,7-dimethoxy-5-acetyl-6-hydroxybenzofurans (1b) and their α,β-unsaturated keto derivatives 6a–g and 7a–g with chlorosulfonyl isocyanate (CSI). On the other hand, N-chlorosulfonyl carbamate derivatives 4a,b, 12a,b and 13a,b were prepared and allowed to react with piperidine to give the corresponding N-piperidinosulfonyl carbamate derivatives 5a,b, 14a,b and 15a,b, respectively. Sixteen new target compounds 3a,b, 10a–g, and 11a–g were tested for their DPPH radical-scavenging, and in vitro antiproliferative activity against A-549, MCF7 and HCT-116 cancer cell lines. Compounds 10a, 11c, 11e, and 11g showed moderate DPPH radical-scavenging activity compared to ascorbic acid at 100 μg/mL. 4,9-Dimethoxy-5-substituted styrylfuro[3,2-g]-1,2,3-benzoxathiazine-7,7-dioxides 11a, 11b, and 11c were found to be highly active against A-549 and HCT-116 cancer cell lines with IC50 values ranging from 0.02 to 0.08 μmol/mL compared to doxorubicin with IC50 = 0.04 and 0.06 μmol/mL, respectively. PMID:25685501

Synthesis and biological activity of novel series of 4-methoxy, and 4,9-dimethoxy-5-substituted furo[2,3-g]-1,2,3-benzoxathiazine-7,7-dioxide derivatives.

PubMed

El-Sawy, Eslam R; Ebaid, Manal S; Abo-Salem, Heba M; El-Hallouty, Salwa; Kassem, Emad M; Mandour, Adel H

2014-05-01

A novel series of 4-methoxy, and 4,9-dimethoxy-5-substituted furo[2,3-g]-1,2,3-benzoxathiazine-7,7-dioxide derivatives 3a,b, 10a-g and 11a-g were prepared in good yields via the reaction of 4-methoxy (1a) and 4,7-dimethoxy-5-acetyl-6-hydroxybenzofurans (1b) and their α,β-unsaturated keto derivatives 6a-g and 7a-g with chlorosulfonyl isocyanate (CSI). On the other hand, N-chlorosulfonyl carbamate derivatives 4a,b, 12a,b and 13a,b were prepared and allowed to react with piperidine to give the corresponding N-piperidinosulfonyl carbamate derivatives 5a,b, 14a,b and 15a,b, respectively. Sixteen new target compounds 3a,b, 10a-g, and 11a-g were tested for their DPPH radical-scavenging, and in vitro antiproliferative activity against A-549, MCF7 and HCT-116 cancer cell lines. Compounds 10a, 11c, 11e, and 11g showed moderate DPPH radical-scavenging activity compared to ascorbic acid at 100 μg/mL. 4,9-Dimethoxy-5-substituted styrylfuro[3,2-g]-1,2,3-benzoxathiazine-7,7-dioxides 11a, 11b, and 11c were found to be highly active against A-549 and HCT-116 cancer cell lines with IC50 values ranging from 0.02 to 0.08 μmol/mL compared to doxorubicin with IC50 = 0.04 and 0.06 μmol/mL, respectively.

APOBEC3G ubiquitination by Nedd4-1 favors its packaging into HIV-1 particles.

PubMed

Dussart, Sylvie; Douaisi, Marc; Courcoul, Marianne; Bessou, Gilles; Vigne, Robert; Decroly, Etienne

2005-01-21

APOBEC3G is a cytidine deaminase that limits the replication of many retroviruses. This antiviral host factor is packaged into retrovirus particles, where it targets single-stranded DNA generated during reverse transcription and induces up to 2% of G-to-A mutations, which are lethal for the HIV-1 provirus. Vif protein counteracts this antiviral factor by decreasing its packaging into lentivirus particles. Here, we demonstrate that Nedd4-1, an HECT E3 ubiquitin ligase, interacts with APOBEC3G, through its WW2 and WW3 domains. As a result of this interaction, APOBEC3G undergoes post-translational modification by addition of ubiquitin moieties. Accordingly, we demonstrate that the dominant negative Nedd4-1 C/S form prevents APOBEC3G ubiquitination. Moreover, the packaging of APOBEC3G into Pr55 Gag virus-like particles and into HIV-1 virions is reduced when Nedd4-1 C/S is expressed. During HIV-1 viral production in the presence of APOBEC3G, Nedd4-1 C/S restores partially the infectivity of Deltavif HIV-1. We conclude that the ubiquitination of APOBEC3G by Nedd4-1 favors its targeting to the virus assembly site where APOBEC3G interacts with Gag and is packaged into HIV-1 particles in the absence of Vif.

Comparison of efficacy of once daily multimatrix mesalazine 2.4 g/day and 4.8 g/day with other 5-aminosalicylic acid preparation in active ulcerative colitis: a randomized, double-blind study.

PubMed

Ogata, Haruhiko; Yokoyama, Tadashi; Mizushima, Seiichi; Hagino, Atsushi; Hibi, Toshifumi

2018-04-01

This study compared the efficacy of multimatrix mesalazine 2.4 g/day and 4.8 g/day with controlled-release mesalazine 2.25 g/day. In this multicenter, randomized, double-blind study, 251 patients with mildly to moderately active ulcerative colitis received multimatrix mesalazine 2.4 g/day once daily (Multimatrix-2.4), 4.8 g/day once daily (Multimatrix-4.8), or controlled-release (time-dependent) mesalazine 2.25 g/day 3 times daily (Time-2.25) for 8 weeks. The primary efficacy endpoint was the change in the ulcerative colitis-disease activity index (UC-DAI) score. The mean change in the UC-DAI score and standard deviation in the per protocol set was -1.9±2.5 for Multimatrix-2.4 and -2.4±2.8 for Time-2.25. The difference between Multimatrix-2.4 and Time-2.25 was 0.3 (two-sided 95% confidence interval [CI], -0.5 to 1.1), thus non-inferiority was not demonstrated based on the pre-defined non-inferiority margin (1.0). In the full analysis set, the difference between Multimatrix-4.8 and Time-2.25 was -1.2 (two-sided 95% CI, -2.0 to -0.5), and the mean change in UC-DAI score in the FAS was -3.3 (two-sided 95% CI, -3.9 to -2.8) for Multimatrix-4.8 and -1.9 (two-sided 95% CI, -2.5 to -1.3) for Multimatrix-2.4, indicating that Multimatrix-4.8 was more effective than Time-2.25 and Multimatrix-2.4. There was no difference among the treatment groups in terms of safety. This study showed that the efficacy of multimatrix mesalazine 2.4 g/day was comparable to controlled release mesalazine 2.25 g/day, although non-inferiority was not demonstrated. Importantly, this was the first study to indicate that multimatrix mesalazine 4.8 g/day was more effective than 2.4g/day with no associated safety concerns.

OVA-bound nanoparticles induce OVA-specific IgG1, IgG2a, and IgG2b responses with low IgE synthesis.

PubMed

Yanase, Noriko; Toyota, Hiroko; Hata, Kikumi; Yagyu, Seina; Seki, Takahiro; Harada, Mitsunori; Kato, Yasuki; Mizuguchi, Junichiro

2014-10-14

There is an urgent requirement for a novel vaccine that can stimulate immune responses without unwanted toxicity, including IgE elevation. We examined whether antigen ovalbumin (OVA) conjugated to the surface of nanoparticles (NPs) (OVA-NPs) with average diameter of 110nm would serve as an immune adjuvant. When BALB/c mice were immunized with OVA-NPs, they developed sufficient levels of OVA-specific IgG1 antibody responses with low levels of IgE synthesis, representing helper T (Th)2-mediated humoral immunity. OVA-specific IgG2a and IgG2b responses (i.e., Th1-mediated immunity) were also induced by secondary immunization with OVA-NPs. As expected, immunization with OVA in alum (OVA-alum) stimulated humoral immune responses, including IgG1 and IgE antibodies, with only low levels of IgG2a/IgG2b antibodies. CD4-positive T cells from mice primed with OVA-NPs produced substantial levels of IL-21 and IL-4, comparable to those from OVA-alum group. The irradiated mice receiving OVA-NPs-primed B cells together with OVA-alum-primed T cells exhibited enhanced anti-OVA IgG2b responses relative to OVA-alum-primed B cells and T cells following stimulation with OVA-NPs. Moreover, when OVA-NPs-primed, but not OVA-alum-primed, B cells were cultured in the presence of anti-CD40 monoclonal antibody, IL-4, and IL-21, or LPS plus TGF-β in vitro, OVA-specific IgG1 or IgG2b antibody responses were elicited, suggesting that immunization with OVA-NPs modulates B cells to generate IgG1 and IgG2b responses. Thus, OVA-NPs might exert their adjuvant action on B cells, and they represent a promising potential vaccine for generating both IgG1 and IgG2a/IgG2b antibody responses with low IgE synthesis. Copyright © 2014 Elsevier Ltd. All rights reserved.

The binding efficiency of RPA to telomeric G-strands folded into contiguous G-quadruplexes is independent of the number of G4 units.

PubMed

Lancrey, Astrid; Safa, Layal; Chatain, Jean; Delagoutte, Emmanuelle; Riou, Jean-François; Alberti, Patrizia; Saintomé, Carole

2018-03-01

Replication protein A (RPA) is a single-stranded DNA binding protein involved in replication and in telomere maintenance. During telomere replication, G-quadruplexes (G4) can accumulate on the lagging strand template and need to be resolved. It has been shown that human RPA is able to unfold a single G4. Nevertheless, the G-strand of human telomeres is prone to fold into higher-order structures formed by contiguous G-quadruplexes. To understand how RPA deals with these structures, we studied its interaction with telomeric G-strands folding into an increasing number of contiguous G4s. The aim of this study was to determine whether the efficiency of binding/unfolding of hRPA to telomeric G-strands depends on the number of G4 units. Our data show that the number n of contiguous G4 units (n ≥ 2) does not affect the efficiency of hRPA to coat transiently exposed single-stranded telomeric G-strands. This feature may be essential in preventing instability due to G4 structures during telomere replication. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

Prognostic value of the PAI-1 4G/5G polymorphism in invasive ductal carcinoma of the breast.

PubMed

Yagmurdur, M C; Atac, F B; Tutar, N U; Verdi, H; Isiklar, I; Ozdemir, B H; Ozbek, N; Karakayali, H; Haberal, M

2008-01-01

The study group was derived from the archive materials of 55 invasive ductal breast cancer (IDC) patients who had undergone breast-preserving surgery (partial mastectomy/ axillary dissection). All patients included in the study had clinically T(1)-2, N0-M0 invasive ductal carcinoma. Genomic DNA species were extracted from paraffin-embedded blocks, and plasminogen activator inhibitor type-1 (PAI-1) gene 4G/5G genotyping was done by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP). Patient demographics, axillary metastasis status, metastatic lymph nodi/total dissected lymph nodes from axilla, histopathologic characteristics of tumors, local recurrences, and survival ratio were assessed. PAI-1 4G/5G genotype frequencies were 4G/4G (64%), 4G/5G (31%), and 5G/5G (5%) in the patient group. According to the results based on frequencies, the demographics were not different. Five-year local recurrence rate of 4G/5G patients was the lowest (2/17, 12%) (P = 0.02). Also five-year distant metastases ratio of 4G/5G patients was the highest (18%) (P = 0.01). Five- and 10-year disease-free survival rates for the 4G/4G, 4G/5G, and 5G/5G groups were 97% and 94%, 82% and 77%, and 100% and 94%, respectively (P = 0.004). The results of this study indicate that the 4G allele in the PAI 1 gene had a negative impact on local recurrence and disease-free survival of patients with clinical T(1)-2N0M0 IDC.

Thermodynamics of triple helix formation: spectrophotometric studies on the d(A)10.2d(T)10 and d(C+3T4C+3).d(G3A4G3).d(C3T4C3) triple helices.

PubMed Central

Pilch, D S; Brousseau, R; Shafer, R H

1990-01-01

We have stabilized the d(A)10.2d(T)10 and d(C+LT4C+3).d(G3A4G3).d(C3T4C3) triple helices with either NaCl or MgCl2 at pH 5.5. UV mixing curves demonstrate a 1:2 stoichiometry of purine to pyrimidine strands under the appropriate conditions of pH and ionic strength. Circular dichroic titrations suggest a possible sequence-independent spectral signature for triplex formation. Thermal denaturation profiles indicate the initial loss of the third strand followed by dissociation of the underlying duplex with increasing temperature. Depending on the base sequence and ionic conditions, the binding affinity of the third strand for the duplex at 25 degrees C is two to five orders of magnitude lower than that of the two strands forming the duplex. Thermodynamic parameters for triplex formation were determined for both sequences in the presence of 50 mM MgCl2 and/or 2.0 M NaCl. Hoogsteen base pairs are 0.22-0.64 kcal/mole less stable than Watson-Crick base pairs, depending on ionic conditions and base composition. C+.G and T.A Hoogsteen base pairs appear to have similar stability in the presence of Mg2+ ions at low pH. PMID:2216768

Distances to Supernova Remnants G31.9+0.0 and G54.4−0.3 Associated with Molecular Clouds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ranasinghe, S.; Leahy, D. A.

2017-07-10

New distances to the supernova remnants (SNRs) G31.9+0.0 and G54.4−0.3 have been found. The analysis method uses H i absorption spectra and CO channel maps. Individual H i channel maps are used to verify absorption features in the H i absorption spectrum or to determine if they have noise. Both of the SNRs are associated with molecular clouds so accurate kinematic velocities are determined. The H iabsorption is used to resolve the kinematic distance ambiguity. The resulting new distance for G31.9+0.0 is 7.1 ± 0.4 kpc and for G54.4−0.3 it is 6.6 ± 0.6 kpc. These are significant revisions tomore » the previous values.« less

g-C3N4 modified TiO2 nanosheets with enhanced photoelectric conversion efficiency in dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Xu, Jian; Wang, Guanxi; Fan, Jiajie; Liu, Baoshun; Cao, Shaowen; Yu, Jiaguo

2015-01-01

Dye-sensitized solar cells (DSSCs) were fabricated by using g-C3N4 modified TiO2 nanosheets (CTS) as photoanode materials in this research. A thin layer of g-C3N4 was coated on the surface of TiO2 nanosheets by simply heating the mixture of TiO2 nanosheets and urea, which led to the formation of TiO2@g-C3N4 nanosheet heterostructure. The experimental results showed that the photoelectric conversion efficiency of DSSCs was obviously improved after modified by g-C3N4. The measurements of I-V characteristic indicated that the introduction of g-C3N4 could increase both the open circuit voltage and short-circuit photocurrent density. Along with the analysis of electrochemical impedance spectroscopy, it is considered that the thin layer of g-C3N4 can act as the blocking layer for electron backward recombination with electrolyte, which can be used as the functional material to increase the DSSC performance.

Formation of g-C3N4@Ni(OH)2 Honeycomb Nanostructure and Asymmetric Supercapacitor with High Energy and Power Density.

PubMed

Dong, Bitao; Li, Mingyan; Chen, Sheng; Ding, Dawei; Wei, Wei; Gao, Guoxin; Ding, Shujiang

2017-05-31

Nickel hydroxide (Ni(OH) 2 ) has been regarded as a potential next-generation electrode material for supercapacitor owing to its attractive high theoretical capacitance. However, practical application of Ni(OH) 2 is hindered by its lower cycling life. To overcome the inherent defects, herein we demonstrate a unique interconnected honeycomb structure of g-C 3 N 4 and Ni(OH) 2 synthesized by an environmentally friendly one-step method. In this work, g-C 3 N 4 has excellent chemical stability and supports a perpendicular charge-transporting direction in charge-discharge process, facilitating electron transportation along that direction. The as-prepared composite exhibits higher specific capacities (1768.7 F g -1 at 7 A g -1 and 2667 F g -1 at 3 mV s -1 , respectively) compared to Ni(OH) 2 aggregations (968.9 F g -1 at 7 A g -1 ) and g-C 3 N 4 (416.5 F g -1 at 7 A g -1 ), as well as better cycling performance (∼84% retentions after 4000 cycles). As asymmetric supercapacitor, g-C 3 N 4 @Ni(OH) 2 //graphene exhibits high capacitance (51 F g -1 ) and long cycle life (72% retentions after 8000 cycles). Moreover, high energy density of 43.1 Wh kg -1 and power density of 9126 W kg -1 has been achieved. This attractive performance reveals that g-C 3 N 4 @Ni(OH) 2 with honeycomb architecture could find potential application as an electrode material for high-performance supercapacitors.

Enhanced visible light photocatalytic activity of g-C3N4 assisted by hydrogen peroxide

NASA Astrophysics Data System (ADS)

Chen, Quan-Liang; Liu, Yi-Ling; Tong, Li-Ge

2018-04-01

Water pollution has caused much attention nowadays. Photocatalysis as a kind of advanced oxidation technology has been widely studied in the field of environmental pollution control. As a stable non-metal photocatalyst, the photocatalytic activity of g-C3N4 assisted by H2O2 was investigated for the degradation of Rhodamine B (RhB) under visible light irradiation. The combination of g-C3N4 and H2O2 has much higher activity than that of pure g-C3N4 or H2O2. Neutral solution is preferred for the high phtotocatalytic activity of g-C3N4 with H2O2. The effect of the amount of catalyst, H2O2 concentration and RhB concentration was investigated. Photocatalytic mechanism study using radical scavenger showed free radicals {{{{O}}}2}- and · OH are the main active species. g-C3N4 assisted by H2O2 showed good photostability and repeatability after five cycles of degradation experiment.

Enhanced photocatalytic performances of ultrafine g-C3N4 nanosheets obtained by gaseous stripping with wet nitrogen

NASA Astrophysics Data System (ADS)

Fan, Chengkong; Feng, Qiang; Xu, Guangqing; Lv, Jun; Zhang, Yong; Liu, Jiaqin; Qin, Yongqiang; Wu, Yucheng

2018-01-01

Graphitic carbon nitride (g-C3N4) is a promising heterogeneous photocatalyst for organics pollutants degradation and water splitting. Herein, we highlight an available pathway to prepare the ultrafine g-C3N4 nanosheets by gaseous stripping of bulk g-C3N4 in wet nitrogen. As comparison, g-C3N4 treated in air and nitrogen atmospheres are also prepared. The obtained products are characterized with X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectra, respectively. Well dispersed g-C3N4 nanosheets can be obtained by this gaseous stripping process in wet nitrogen, which possess much higher specific surface area (211.2 m2 g-1) than that of bulk g-C3N4 (15.3 m2 g-1). Both RhB degradation and water splitting are applied to characterize the photocatalytic performances of the ultrafine g-C3N4 nanosheets. The g-C3N4 (w-N2) nanosheets can degrade 20 mg/L RhB completely within 12 min under visible light illumination, which is 5.32 times faster than that of bulk g-C3N4. Also, the g-C3N4 (w-N2) nanosheets possess the highest photocatalytic hydrogen evolution rate of 1113.48 μmol h-1 g-1 under visible light illumination, which is 6 times that of bulk g-C3N4. The mechanisms of enhancing the photocatalytic performance are discussed to be the higher oxidation ability of VB and higher specific surface area (211.2 m2/g) of the ultrafine g-C3N4 nanosheets.

Meta-Analysis of the Association between Plasminogen Activator Inhibitor-1 4G/5G Polymorphism and Recurrent Pregnancy Loss

PubMed Central

Li, Xuejiao; Liu, Yukun; Zhang, Rui; Tan, Jianping; Chen, Libin; Liu, Yinglin

2015-01-01

Background The association between plasminogen activator inhibitor-1 (PAI-1) 4G/5G polymorphism and recurrent pregnancy loss (RPL) risk is still contradictory. We thus performed a meta-analysis. Material/Methods Relevant studies were searched for in PubMed, Web of Science, Embase, and Cochrane Library. An odds ratio (OR) with a 95% confidence interval (CI) was used to assess the association between PAI-1 4G/5G polymorphism and RPL risk. Results A total of 22 studies with 4306 cases and 3076 controls were included in this meta-analysis. We found that PAI-1 4G/5G polymorphism was significantly associated with an increased RPL risk (OR=1.89; 95% CI 1.34–2.67; P=0.0003). In the subgroup analysis by race, PAI-1 4G/5G polymorphism was significantly associated with an increased RPL risk in Caucasians (OR=2.23; 95% CI 1.44–3.46; P=0.0003). However, no significant association was observed in Asians (OR=1.47; 95% CI 0.84–2.59; P=0.18). Conclusions In conclusion, this meta-analysis suggests that PAI-1 4G/5G polymorphism might be associated with RPL development in Caucasians. PMID:25862335

Traffic Dimensioning and Performance Modeling of 4G LTE Networks

ERIC Educational Resources Information Center

Ouyang, Ye

2011-01-01

Rapid changes in mobile techniques have always been evolutionary, and the deployment of 4G Long Term Evolution (LTE) networks will be the same. It will be another transition from Third Generation (3G) to Fourth Generation (4G) over a period of several years, as is the case still with the transition from Second Generation (2G) to 3G. As a result,…

CeVO4 nanofibers hybridized with g-C3N4 nanosheets with enhanced visible-light-driven photocatalytic activity

NASA Astrophysics Data System (ADS)

Li, Li; Wang, Haoran; Wang, Xiong

2018-01-01

The g-C3N4/CeVO4 composites were successfully synthesized by hybridizing CeVO4 nanofibers with g-C3N4 nanosheets. The photocatalytic activity of g-C3N4/CeVO4 composites was evaluated for the photodegradation of methylene blue under visible light irradiation. Among them, the 50 wt% g-C3N4/CeVO4 composites presented the highest photocatalytic activity, about 2 and 3.2 times higher than those of CeVO4 and g-C3N4, respectively. The improved catalytic activity was owed to the hybridization, which facilitated the rapid separation of photoinduced carriers and enhanced the visible light harvesting. A possible photocatalytic mechanism was proposed.

The plasminogen activator inhibitor-1 (PAI-1) gene -844 A/G and -675 4G/5G promoter polymorphism significantly influences plasma PAI-1 levels in women with polycystic ovary syndrome.

PubMed

Lin, Sun; Huiya, Zhang; Bo, Liu; Wei, Wei; Yongmei, Guan

2009-12-01

Mutations in the plasminogen activator inhibitor-1 (PAI-1) gene, along with increased PAI-1 levels, have been implicated in the pathogenesis of polycystic ovarian syndrome (PCOS). We investigated a possible influence of the promoter polymorphism (-844 A/G and -675 4G/5G) in the PAI-1 gene on plasma PAI-1 levels in 126 PCOS patients and 97 healthy controls. Levels of total testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH), fasting plasma glucose (FPG), fasting insulin, and PAI-1 were measured, and body mass index (BMI), waist-to-hip ratio (WHR), LH/FSH ratio, and homeostasis model assessment for insulin resistance (HOMA-IR) were calculated. PAI-1 -675 4G/5G and -844 A/G gene polymorphisms were also performed. Total testosterone, fasting insulin, and PAI-1 levels; BMI, LH/FSH, and HOMA-IR were significantly higher in PCOS patients than controls (P < 0.05). The odds ratio of 4G/4G genotype, 4G allele, and the combination genotype of 4G/4G and -844 A/A were 2.49 (95% confidence interval (CI), 1.4-4.44), 2.1 (95% CI, 1.43-3.08), and 2.9 (95% CI, 1.41-5.98), respectively, (P < 0.001). In the PCOS group, the PAI-1 level of the A/A was significantly higher than that of the A/G or G/G genotype, similarly was 4G/4G genotype compared with 4G/5G or 5G/5G genotype. The plasma PAI-1 levels of the combination of the PAI-1 -844 A/A and -675 4G/4G or 4G/5G genotypes, or the coadunation of 4G/4G and -844 non-G/G (A/A + A/G) genotypes were significantly high in PCOS women compared with controls. A trend to a positive interaction between PAI-1 -675 4G/5G and -844 A/G gene polymorphism may elevate plasma PAI-1 levels and hypofibrinolysis, which is probably an important hereditary risk factor in PCOS.

PAI-1 4G-4G and MTHFR 677TT in non-hepatitis C virus/hepatitis B virus-related liver cirrhosis

PubMed Central

Pasta, Linda; Pasta, Francesca

2015-01-01

AIM: To evaluate the different roles of thrombophilia in patients with and without viral etiology. The thrombophilic genetic factors (THRGFs), PAI-1 4G-4G, MTHFR 677TT, V Leiden 506Q and prothrombin 20210A, were studied as risk factors in 1079 patients with liver cirrhosis (LC), enrolled from January 2000 to January 2014. METHODS: All Caucasian LC patients consecutively observed in a fourteen-year period were included; the presence of portal vein thrombosis (PVT) and Budd Chiari syndrome (BCS) was registered. The differences between the proportions of each THRGF with regard to the presence or absence of viral etiology and the frequencies of the THRGF genotypes with those predicted in a population by the Hardy-Weinberg equilibrium were registered. RESULTS: Four hundred and seventeen/one thousand and seventy-six patients (38.6%) showed thrombophilia: 217 PAI-1 4G-4G, 176 MTHFR C677TT, 71 V Leiden factor and 41 prothrombin G20210 A, 84 with more than 1 THRGF; 350 presented with no viral liver cirrhosis (NVLC) and 729 with, called viral liver cirrhosis (VLC), of whom 56 patients were hepatitis C virus + hepatitis B virus. PAI-1 4G-4G, MTHFR C677TT, the presence of at least one TRHGF and the presence of > 1 THRGF, were statistically more frequent in patients with NVLC vs patients with VLC: All χ2 > 3.85 and P < 0.05. Patients with PVT and/or BCS with at least one TRHGF were 189/352 (53.7%). The Hardy-Weinberg of PAI-1 and MTHFR 677 genotypes deviated from that expected from a population in equilibrium in patients with NVLC (respectively χ2 = 39.3; P < 0.000 and χ2 = 27.94; P < 0.05), whereas the equilibrium was respected in VLC. CONCLUSION: MTHFR 677TT was nearly twofold and PAI-1 4G-4G more than threefold more frequently found in NVLC vs patients with VLC; the Hardy-Weinberg equilibrium of these two polymorphisms confirms this data in NVLC. We suggest that PAI-1 4G-4G and MTHFR 677TT could be considered as factors of fibrosis and thrombosis mechanisms, increasing

PAI-1 4G-4G and MTHFR 677TT in non-hepatitis C virus/hepatitis B virus-related liver cirrhosis.

PubMed

Pasta, Linda; Pasta, Francesca

2015-12-18

To evaluate the different roles of thrombophilia in patients with and without viral etiology. The thrombophilic genetic factors (THRGFs), PAI-1 4G-4G, MTHFR 677TT, V Leiden 506Q and prothrombin 20210A, were studied as risk factors in 1079 patients with liver cirrhosis (LC), enrolled from January 2000 to January 2014. All Caucasian LC patients consecutively observed in a fourteen-year period were included; the presence of portal vein thrombosis (PVT) and Budd Chiari syndrome (BCS) was registered. The differences between the proportions of each THRGF with regard to the presence or absence of viral etiology and the frequencies of the THRGF genotypes with those predicted in a population by the Hardy-Weinberg equilibrium were registered. Four hundred and seventeen/one thousand and seventy-six patients (38.6%) showed thrombophilia: 217 PAI-1 4G-4G, 176 MTHFR C677TT, 71 V Leiden factor and 41 prothrombin G20210 A, 84 with more than 1 THRGF; 350 presented with no viral liver cirrhosis (NVLC) and 729 with, called viral liver cirrhosis (VLC), of whom 56 patients were hepatitis C virus + hepatitis B virus. PAI-1 4G-4G, MTHFR C677TT, the presence of at least one TRHGF and the presence of > 1 THRGF, were statistically more frequent in patients with NVLC vs patients with VLC: All χ (2) > 3.85 and P < 0.05. Patients with PVT and/or BCS with at least one TRHGF were 189/352 (53.7%). The Hardy-Weinberg of PAI-1 and MTHFR 677 genotypes deviated from that expected from a population in equilibrium in patients with NVLC (respectively χ (2) = 39.3; P < 0.000 and χ (2) = 27.94; P < 0.05), whereas the equilibrium was respected in VLC. MTHFR 677TT was nearly twofold and PAI-1 4G-4G more than threefold more frequently found in NVLC vs patients with VLC; the Hardy-Weinberg equilibrium of these two polymorphisms confirms this data in NVLC. We suggest that PAI-1 4G-4G and MTHFR 677TT could be considered as factors of fibrosis and thrombosis mechanisms, increasing the inflammation response

Long-range magnetic order in the Heisenberg pyrochlore antiferromagnets G d2G e2O7 and G d2P t2O7 synthesized under high pressure

NASA Astrophysics Data System (ADS)

Li, X.; Cai, Y. Q.; Cui, Q.; Lin, C. J.; Dun, Z. L.; Matsubayashi, K.; Uwatoko, Y.; Sato, Y.; Kawae, T.; Lv, S. J.; Jin, C. Q.; Zhou, J.-S.; Goodenough, J. B.; Zhou, H. D.; Cheng, J.-G.

2016-12-01

G d2S n2O7 and G d2T i2O7 have been regarded as good experimental realizations of the classical Heisenberg pyrochlore antiferromagnet with dipolar interaction. The former was found to adopt the Palmer-Chalker state via a single, first-order transition at TN≈1 K , while the latter enters a distinct, partially ordered state through two successive transitions at TN 1≈1 K and TN 2= 0.75 K . To shed more light on their distinct magnetic ground states, we have synthesized two more gadolinium-based pyrochlore oxides, G d2G e2O7 and G d2P t2O7 , under high-pressure conditions and performed detailed characterizations via x-ray powder diffraction, dc and ac magnetic susceptibility, and specific heat measurements down to 100 mK. We found that both compounds enter a long-range antiferromagnetically ordered state through a single, first-order transition at TN= 1.4 K for G d2G e2O7 and TN= 1.56 K for G d2P t2O7 , with the specific heat anomaly similar to that of G d2S n2O7 rather than G d2T i2O7 . Interestingly, the low-temperature magnetic specific heat values of both G d2G e2O7 and G d2P t2O7 were found to follow nicely the T3 dependence as expected for a three-dimensional antiferromagnet with gapless spin-wave excitations. We have rationalized the enhancement of TN in terms of the reduced Gd-Gd distances for the chemically pressurized G d2G e2O7 and the addition of extra superexchange pathways through the empty Pt -eg orbitals for G d2P t2O7 . Our current study has expanded the family of gadolinium-based pyrochlores and permits us to achieve a better understanding of their distinct magnetic properties in a more comprehensive perspective.

An oxygen-vacancy-rich Z-scheme g-C3N4/Pd/TiO2 heterostructure for enhanced visible light photocatalytic performance

NASA Astrophysics Data System (ADS)

Guo, Yanru; Xiao, Limin; Zhang, Min; Li, Qiuye; Yang, Jianjun

2018-05-01

An oxygen-vacancy-rich Z-scheme g-C3N4/Pd/TiO2 ternary nanocomposite was fabricated using nanotubular titanic acid as precursors via a simple photo-deposition of Pd nanoparticles and calcination process. The prepared nanocomposites were investigated by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and UV-visible diffuse reflectance spectroscopy, respectively. For g-C3N4/TiO2 binary nanocomposites, at the optimal content of g-C3N4 (2%), the apparent photocatalytic activity of 2%g-C3N4/TiO2 was 9 times higher than that of pure TiO2 under visible-light illumination. After deposition of Pd (1 wt%) at the contact interface between g-C3N4 and TiO2, the 2%g-C3N4/Pd/TiO2 ternary nanocomposites demonstrated the highest visible-light-driven photocatalytic activity for the degradation of gaseous propylene, which was 16- and 2-fold higher activities than pure TiO2 and 2%g-C3N4/TiO2, respectively. The mechanism for the enhanced photocatalytic performance of the g-C3N4/Pd/TiO2 photo-catalyst is proposed to be based on the efficient separation of photo-generated electron-hole pairs through Z-scheme system, in which uniform dispersity of Pd nanoparticles at contact interface between g-C3N4 and TiO2 and oxygen vacancies promote charge separation.

Comparison of efficacy of once daily multimatrix mesalazine 2.4 g/day and 4.8 g/day with other 5-aminosalicylic acid preparation in active ulcerative colitis: a randomized, double-blind study

PubMed Central

Yokoyama, Tadashi; Mizushima, Seiichi; Hagino, Atsushi; Hibi, Toshifumi

2018-01-01

Background/Aims This study compared the efficacy of multimatrix mesalazine 2.4 g/day and 4.8 g/day with controlled-release mesalazine 2.25 g/day. Methods In this multicenter, randomized, double-blind study, 251 patients with mildly to moderately active ulcerative colitis received multimatrix mesalazine 2.4 g/day once daily (Multimatrix-2.4), 4.8 g/day once daily (Multimatrix-4.8), or controlled-release (time-dependent) mesalazine 2.25 g/day 3 times daily (Time-2.25) for 8 weeks. The primary efficacy endpoint was the change in the ulcerative colitis-disease activity index (UC-DAI) score. Results The mean change in the UC-DAI score and standard deviation in the per protocol set was −1.9±2.5 for Multimatrix-2.4 and −2.4±2.8 for Time-2.25. The difference between Multimatrix-2.4 and Time-2.25 was 0.3 (two-sided 95% confidence interval [CI], −0.5 to 1.1), thus non-inferiority was not demonstrated based on the pre-defined non-inferiority margin (1.0). In the full analysis set, the difference between Multimatrix-4.8 and Time-2.25 was −1.2 (two-sided 95% CI, −2.0 to −0.5), and the mean change in UC-DAI score in the FAS was −3.3 (two-sided 95% CI, −3.9 to −2.8) for Multimatrix-4.8 and −1.9 (two-sided 95% CI, −2.5 to −1.3) for Multimatrix-2.4, indicating that Multimatrix-4.8 was more effective than Time-2.25 and Multimatrix-2.4. There was no difference among the treatment groups in terms of safety. Conclusions This study showed that the efficacy of multimatrix mesalazine 2.4 g/day was comparable to controlled release mesalazine 2.25 g/day, although non-inferiority was not demonstrated. Importantly, this was the first study to indicate that multimatrix mesalazine 4.8 g/day was more effective than 2.4g/day with no associated safety concerns. PMID:29743838

Enhanced HIV-1 neutralization by a CD4-VH3-IgG1 fusion protein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meyuhas, Ronit; Noy, Hava; Fishman, Sigal

2009-08-21

HIV-1 gp120 is an alleged B cell superantigen, binding certain VH3+ human antibodies. We reasoned that a CD4-VH3 fusion protein could possess higher affinity for gp120 and improved HIV-1 inhibitory capacity. To test this we produced several human IgG1 immunoligands harboring VH3. Unlike VH3-IgG1 or VH3-CD4-IgG1, CD4-VH3-IgG1 bound gp120 considerably stronger than CD4-IgG1. CD4-VH3-IgG1 exhibited {approx}1.5-2.5-fold increase in neutralization of two T-cell laboratory-adapted strains when compared to CD4-IgG1. CD4-VH3-IgG1 improved neutralization of 7/10 clade B primary isolates or pseudoviruses, exceeding 20-fold for JR-FL and 13-fold for Ba-L. It enhanced neutralization of 4/8 clade C viruses, and had negligible effect onmore » 1/4 clade A pseudoviruses. We attribute this improvement to possible pairing of VH3 with CD4 D1 and stabilization of an Ig Fv-like structure, rather than to superantigen interactions. These novel findings support the current notion that CD4 fusion proteins can act as better HIV-1 entry inhibitors with potential clinical implications.« less

Fabrication of 2D SnS2/g-C3N4 heterojunction with enhanced H2 evolution during photocatalytic water splitting.

PubMed

Liu, Enzhou; Chen, Jibing; Ma, Yongning; Feng, Juan; Jia, Jia; Fan, Jun; Hu, Xiaoyun

2018-08-15

In this work, the 2D SnS 2 /g-C 3 N 4 heterojunctions were successfully prepared by heating the homogeneous dispersion of SnS 2 nanosheets and g-C 3 N 4 nanosheets using a microwave muffle. SEM, TEM and HRTEM images indicated that the SnS 2 nanosheets were loaded on the surface of the g-C 3 N 4 nanosheets. The UV-vis spectra show that the absorption intensity of the as-prepared samples was increased and the absorption range was also extended from 420 nm to approximately 600 nm. The H 2 production rate over 5 wt% SnS 2 /g-C 3 N 4 can reach 972.6 μmol·h -1 ·g -1 under visible light irradiation (λ > 420 nm) using TEOA as the sacrifice agent and Pt as the electron trap, which is 2.9 and 25.6 times higher than those of the pristine g-C 3 N 4 and SnS 2 , respectively. According to the obtained PL spectra, photocurrent and EIS spectra, the enhanced performance for H 2 generation over the heterojunctions is primarily ascribed to the rapid charge transfer arising from the suitable band gap positions leading to an improved photocatalytic performance. The recycling experiments indicated that the as-prepared composites exhibit good stability in H 2 production. Additionally, a possible enhanced mechanism for H 2 evolution was deduced based on the results obtained by various characterization techniques. Copyright © 2018 Elsevier Inc. All rights reserved.

Th1/Th2 cytokine profiles in G+/G- bacteremia in pediatric hematology/oncology patients.

PubMed

Tang, Yongmin; Liao, Chan; Xu, Xiaojun; Song, Hua; Shi, Shuwen; Yang, Shilong

2012-01-01

Early diagnosis of infection and appropriate choice of antibiotics are essential not only to improve the prognosis of the patients but also to prevent from the abuse of the antibiotics in hematology/oncology children at the time of neutropenia after intensive chemotherapy. We evaluated the quantification of Th1/Th2 cytokines with flow cytometry bead assay (CBA) in 145 hospitalized febrile hematology/oncology children with positive blood culture to seek for a rapid diagnostic method to determine the type of infection. IL-4, IL-6, IL-10, TNF-α, and IFN-γ levels from both G- and G+ bacteremia groups were significantly higher than those of controls (P < 0.001). The median levels of IL-6, IL-10, TNF-α of Group G- were 525.4, 96.0, and 6.9 pg/ml, respectively, significantly higher than those of Group G+ (150.0, 22.6, and 4.5 pg/ml, respectively, P < 0.001). According to the different degrees of increased IL-6 and IL-10 levels, we named the G- bacterial infection related cytokine profile G- BIRCP and the G+ BIRCP. The specificity and sensitivity of BIRCP prediction for G- and G+ bacteria cultures were 60.2% and 75.4%, 66.8% and 70.1%, respectively. Similar therapeutic efficacy was achieved between BIRCP-based and broad-spectrum antibiotics groups (86.1% vs. 89.3%, P > 0.05), which was significantly increased as compared with that (65.5%, P < 0.05) of empirical group. These results showed the promising use of the IL-6/IL-10/TNF-α determination with CBA technology for the early and rapid diagnosis, evaluation of G+/G- bacteremia in pediatric hematology/oncology patients. Copyright © 2011 Wiley Periodicals, Inc.

Association between plasminogen activator inhibitor-1 -675 4G/5G polymorphism and sepsis: a meta-analysis.

PubMed

Li, Li; Nie, Wei; Zhou, Hongfeng; Yuan, Weifeng; Li, Weifeng; Huang, Wenjie

2013-01-01

Several studies have evaluated the association between plasminogen activator inhibitor-1 (PAI-1) -675 4G/5G polymorphism and sepsis in different populations. However, the available results are conflicting. A search of Pubmed and EMBASE databases was performed to identify relevant studies for inclusion in the meta-analysis. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were determined using a random-effects model. Twelve case-control studies and three cohort studies were included. Overall, a significant association between 4G/5G polymorphism and sepsis risk was observed for 4G/4G vs. 4G/5G +5G/5G (OR = 1.30, 95% CI 1.08-1.56, P = 0.006). In addition, there was a significant association between PAI-1 4G/5G polymorphism and sepsis-related mortality (OR = 1.72, 95% CI 1.27-2.33, P = 0.0005). In subgroup analyses, increased sepsis risk and mortality risk were found in Caucasians and in patients with sepsis. This meta-analysis suggested that the PAI-1 -675 4G/5G polymorphism was a risk factor for sepsis and sepsis mortality.

A weak-light-responsive TiO2/g-C3N4 composite film: photocatalytic activity under low-intensity light irradiation.

PubMed

Wang, Peifang; Guo, Xiang; Rao, Lei; Wang, Chao; Guo, Yong; Zhang, Lixin

2018-05-10

A TiO 2 /g-C 3 N 4 composite photocatalytic film was prepared by in situ synthesis method and its photocatalytic capability under weak-visible-light condition was studied. The co-precursor with different ratio of melamine and TiO 2 sol-gel precursor were treated using ultrasonic mixing, physical deposition, and co-sintering method to form the smooth, white-yellow, and compact TiO 2 /g-C 3 N 4 composite films. The prepared TiO 2 /g-C 3 N 4 materials were characterized by SEM, TEM, EDS, XRD, BET, VBXPS, and UV-vis diffuse reflectance spectra. The results of composite showed that TiO 2 and g-C 3 N 4 have close interfacial connections which are favorable to charge transfer between these two semiconductors with suitable band structure, g-C 3 N 4 retard the anatase-to-rutile phase transition of TiO 2 significantly, the specific surface area were increased with g-C 3 N 4 ratio raised. Under weak-light irradiation, composite films photocatalytic experiments exhibited RhB removal efficiency approaching 90% after three recycles. Powders suspension degradation experiments revealed the removal efficiency of TiO 2 /g-C 3 N 4 (90.8%) was higher than pure TiO 2 (52.1%) and slightly lower than pure g-C 3 N 4 (96.6%). By control experiment, the enhanced photocatalysis is ascribed to the combination of TiO 2 and g-C 3 N 4 , which not only produced thin films with greater stability but also formed heterojunctions that can be favorable to charge transfer between these two semiconductors with suitable band structure. This study presents the potential application of photocatalytic film in the wastewater treatment under weak-light situation.

Enhanced photocatalytic activity of electrospun nanofibrous TiO2/g-C3N4 heterojunction photocatalyst under simulated solar light

NASA Astrophysics Data System (ADS)

Wang, Chunlei; Hu, Liming; Chai, Bo; Yan, Juntao; Li, Jianfen

2018-02-01

Electrospun nanofibrous TiO2/g-C3N4 heterojunction photocatalysts with different TiO2 content have been synthesized via a facile electrospinning and subsequent in situ evaporation and calcination process for the first time, which are examined in terms of morphology, component content, optical properties, PL spectra, photocurrent response, EIS measurement, photocatalytic activity and mechanism. SEM images exhibit TiO2/g-C3N4-4 heterojunction photocatalyst possesses the excellent 1D structure. HRTEM and element mapping images confirm the formation of heterojunction structure. DRS tests identify that TiO2/g-C3N4-4 heterojunction exhibits the intensitive absorption in both UV and visible light region. The photoelectrochemical tests prove that the recombination between electrons and holes are effectively inhibited. Based on TG analysis and photodegradation experiments, TiO2/g-C3N4-4 heterojunction photocatalyst with TiO2 content of 29.30 wt% possesses the best photocatalytic degradation efficiency for the RhB among the g-C3N4, TiO2 and their mixture under simulated sunlight irradiation. Moreover, 1D morphology of TiO2/g-C3N4-4 heterojunction photocatalyst is in favor of separating from solution for reuse and transferring the electrons, and maintains a very high photocatalytic degradation efficiency of 96% even after four recycles experiments, which is beneficial for practical application.

Photocatalytic reduction of CO2 into hydrocarbon solar fuels over g-C3N4-Pt nanocomposite photocatalysts.

PubMed

Yu, Jiaguo; Wang, Ke; Xiao, Wei; Cheng, Bei

2014-06-21

Photocatalytic reduction of CO2 into renewable hydrocarbon fuels is an alternative way to develop reproducible energy, which is also a promising way to solve the problem of the greenhouse effect. In this work, graphitic carbon nitride (g-C3N4) was synthesized by directly heating thiourea at 550 °C and then a certain amount of Pt was deposited on it to form g-C3N4-Pt nanocomposites used as catalysts for photocatalytic reduction of CO2 under simulated solar irradiation. The main products of photocatalysis were CH4, CH3OH and HCHO. The deposited Pt acted as an effective cocatalyst, which not only influenced the selectivity of the product generation, but also affected the activity of the reaction. The yield of CH4 first increased upon increasing the amount of Pt deposited on the g-C3N4 from 0 to 1 wt%, then decreased at 2 wt% Pt loading. The production rates of CH3OH and HCHO also increased with the content of Pt increasing from 0 to 0.75 wt% and the maximum yield was observed at 0.75 wt%. The Pt nanoparticles (NPs) could facilitate the transfer and enrichment of photogenerated electrons from g-C3N4 to its surface for photocatalytic reduction of CO2. At the same time, Pt was also used a catalyst to promote the oxidation of products. The transient photocurrent response further confirmed the proposed photocatalytic reduction mechanism of CO2. This work indicates that the deposition of Pt is a good strategy to improve the photoactivity and selectivity of g-C3N4 for CO2 reduction.

Association of G894T eNOS, 4G/5G PAI and T1131C APOA5 polymorphisms with susceptibility to myocardial infarction in Morocco.

PubMed

Hassani Idrissi, Hind; Hmimech, Wiam; Diakite, Brehima; Korchi, Farah; Baghdadi, Dalila; Habbal, Rachida; Nadifi, Sellama

2016-09-01

Myocardial infarction (MI) is a common multifactorial disease. Numerous studies have found that genetic plays an essential role in MI occurrence. The main objective of our case-control study is to explore the association of G894T eNOS (rs1799983), 4G/5G PAI (rs1799889) and T1131C APOA5 (rs662799) polymorphisms with MI susceptibility in the Moroccan population. 118 MI patients were recruited vs 184 healthy controls. DNA samples were genotyped by PCR-RFLP method using MboI, BslI and MseI restriction enzymes respectively for the G894T eNOS, 4G/5G PAI and T1131C APOA5 polymorphisms. Our results show that the G894T eNOS was significantly associated with increased risk of MI under the three genetic transmission models (dominant: OR = 1.64, 95% CI = 1.05-2.58, P = 0.003; recessive: OR = 2.15, 95% CI = 0.74-6.16, P = 0.03; additive: OR = 1.54, 95% CI = 1.06-2.23, P = 0.001). The T1131C APOA5 polymorphism was associated to MI risk in recessive and additive models (OR = 1.53, 95% CI = 0.72-3.2, P = 0.04 and OR = 1.78, 95% CI = 1.26-2.51, P = 0.03 respectively). For the 4G/5G PAI variant, even the cases and controls groups were not in Hardy-Weinberg Equilibrium (HWE), the dominant and additive models show a statistically significant association with MI risk (OR = 7.96, 95%CI = 3.83-16.36, P = 0.01 and OR = 1.96, 95% CI = 1.4-2.72, P = 0.03 respectively). Our results suggest that G894T eNOS and T1131C APOA5 polymorphisms may be considered as genetic markers of MI among the Moroccan population. Further studies including larger sample sizes and exploring more genetic associations are needed to confirm our results and to better understand the susceptibility to MI.

Isolation and characterization of rabbit anti-m3 2,2,7G antibodies.

PubMed Central

Luhrmann, R; Appel, B; Bringmann, P; Rinke, J; Reuter, R; Rothe, S; Bald, R

1982-01-01

Antibodies specific for intact 2,2,7-trimethylguanosine (m3 2,2,7G) were induced by immunization of rabbits with a nucleoside-human serum albumen (HSA) conjugate. Competition radioimmunoassay showed that the antibody distinguishes well between intact m3 2,2,7G and its alkali-hydrolysed form (m3 2,2,7G*). Antibody specificity is largely dependent on the presence of all three methyl groups in m3 2,2,7G: none of the less extensively methylated nucleosides m7G, m2G and m2 2,2G is able to compete efficiently with the homologous hapten. Little or no competition was observed with m1G, m1A, m6A, m5U and each of the four unmodified ribonucleosides. Binding studies with nucleoplasmic RNAs from Ehrlich ascites cells suggest that the antibody reacts specifically with the m3 2,2,7G-containing cap structure of the small nuclear U-RNAs (U-snRNAs). Thus the antibody should be a valuable tool for studying the role of the 5'-terminal regions of the U-snRNAs of eucaryotic cells. Images PMID:7155893

NIa-Pro of Papaya ringspot virus interacts with Carica papaya eukaryotic translation initiation factor 3 subunit G (CpeIF3G).

PubMed

Gao, Le; Tuo, Decai; Shen, Wentao; Yan, Pu; Li, Xiaoying; Zhou, Peng

2015-02-01

The interaction of papaya eukaryotic translation initiation factor 3 subunit G (CpeIF3G) with Papaya ringspot virus (PRSV) NIa-Pro was validated using a bimolecular fluorescence complementation assay in papaya protoplasts based on the previous yeast two-hybrid assay results. The C-terminal (residues 133-239) fragment of PRSV NIa-Pro and the central domain (residues 59-167) of CpeIF3G were required for effective interaction between NIa-Pro and CpeIF3G as shown by a Sos recruitment yeast two-hybrid system with several deletion mutants of NIa-Pro and CpeIF3G. The central domain of CpeIF3G, which contains a C2HC-type zinc finger motif, is required to bind to other eIFs of the translational machinery. In addition, quantitative real-time reverse transcription PCR assay confirmed that PRSV infection leads to a 2- to 4.5-fold up-regulation of CpeIF3G mRNA in papaya. Plant eIF3G is involved in various stress response by enhancing the translation of resistance-related proteins. It is proposed that the NIa-Pro-CpeIF3G interaction may impair translation preinitiation complex assembly of defense proteins and interfere with host defense.

Association between Plasminogen Activator Inhibitor-1 -675 4G/5G Polymorphism and Sepsis: A Meta-Analysis

PubMed Central

Yuan, Weifeng; Li, Weifeng; Huang, Wenjie

2013-01-01

Background Several studies have evaluated the association between plasminogen activator inhibitor-1 (PAI-1) -675 4G/5G polymorphism and sepsis in different populations. However, the available results are conflicting. Methods A search of Pubmed and EMBASE databases was performed to identify relevant studies for inclusion in the meta-analysis. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were determined using a random-effects model. Results Twelve case-control studies and three cohort studies were included. Overall, a significant association between 4G/5G polymorphism and sepsis risk was observed for 4G/4G vs. 4G/5G +5G/5G (OR = 1.30, 95% CI 1.08–1.56, P = 0.006). In addition, there was a significant association between PAI-1 4G/5G polymorphism and sepsis-related mortality (OR = 1.72, 95% CI 1.27–2.33, P = 0.0005). In subgroup analyses, increased sepsis risk and mortality risk were found in Caucasians and in patients with sepsis. Conclusions This meta-analysis suggested that the PAI-1 -675 4G/5G polymorphism was a risk factor for sepsis and sepsis mortality. PMID:23382992

Cytotoxicity of chloroacetanilide herbicide alachlor in HepG2 cells independent of CYP3A4 and CYP3A7.

PubMed

Miranda, Sonia R; Meyer, Sharon A

2007-05-01

Alachlor is cytotoxic to human hepatoblastoma HepG2s, a cell line that expresses constitutive CYP3A7 and dexamethasone (DEX)-inducible CYP3A4 and CYP3A7. CYP3A4 catalyzes alachlor N-dealkylation to 2-chloro-N-(2,6-diethylphenyl)acetamide (CDEPA), precursor of 2,6-diethylbenzoquinoneimine, putative reactive metabolite for rat nasal carcinogenicity. We hypothesized that HepG2 alachlor cytotoxicity would be mediated by CYP3A4/7 and increased with DEX. Here, we report time-dependent alachlor cytotoxicity (EC(50) approximately 500 microM and 264+/-17 microM at 6 and 24h, respectively) as assessed by lactate dehydrogenase leakage. DEX pretreatment (25 microM, 48 h) significantly increased CYP3A7-catalyzed luciferin 6' benzylether O-debenzylation, but had no effect on alachlor toxicity. Further, CYP3A4/7 inhibitor triacetyloleandomycin did not prevent, but rather potentiated, alachlor cytotoxicity. In agreement, CDEPA was less toxic than parent alachlor. HepG2 CYP3A4 activity was unaffected by 48 h DEX pretreatment; therefore, studies were done in DPX-2 cells, a HepG2 derivative engineered to overexpress pregnane-X receptor (PXR) that exhibits rifampicin (RIF)-inducible endogenous CYP3A4. Alachlor cytotoxicity in DPX-2 cells occurred over a concentration range equivalent to that in HepG2. CYP3A4 activity of DPX-2 cells treated with RIF (10 microM, 48 h) was twice that of untreated cells, but RIF did not increase alachlor toxicity. These results demonstrate that neither CYP3A4 nor CYP3A7 initiate a pathway leading to a toxic alachlor metabolite.

Enhanced photocatalytic H2-production activity of C-dots modified g-C3N4/TiO2 nanosheets composites.

PubMed

Li, Yang; Feng, Xionghan; Lu, Zhexue; Yin, Hui; Liu, Fan; Xiang, Quanjun

2018-03-01

As a new carbon-based material, carbon dots (C-dots) have got widely preference because of its excellent electronic transfer capability. In this work, a novel ternary layered C-dots/g-C 3 N 4 /TiO 2 nanosheets (CGT) composite photocatalysts were prepared by impregnation precipitation methods. The optimal ternary CGT composite samples revealed high photocatalytic hydrogen evolution rate in triethanolamine aqueous solutions, which exceeded the rate of the optimal g-C 3 N 4 /TiO 2 composite sample by a factor of 5 times. The improved photocatalytic activity is owed to the positive effects of C-dots and layered heterojunction structure of TiO 2 nanosheets and g-C 3 N 4 sheets. C-dots in the CGT composites can serve as electron reservoirs to capture the photo-induced electrons. The well-defined layered heterojunction structure of CGT provides the intimate contact and the strong interaction of anatase TiO 2 nanosheets and g-C 3 N 4 sheets via face-to-face orientation, which restrains the recombination of photogenerated charge carriers, and thus enhances the photocatalytic H 2 -production activity. Electron paramagnetic resonance and transient photocurrent response proved the strong interaction and improved interfacial charge transfer of TiO 2 nanosheets and g-C 3 N 4 sheets, respectively. The mechanism of improving the photocatalytic H 2 -evolution activity was further confirmed by time-resolved fluorescence, electron paramagnetic resonance, transient photocurrent response and electrochemical impedance spectroscopy. Copyright © 2017 Elsevier Inc. All rights reserved.

2D-2D stacking of graphene-like g-C3N4/Ultrathin Bi4O5Br2 with matched energy band structure towards antibiotic removal

NASA Astrophysics Data System (ADS)

Ji, Mengxia; Di, Jun; Ge, Yuping; Xia, Jiexiang; Li, Huaming

2017-08-01

A novel visible-light-driven 2D-2D graphene-like g-C3N4/ultrathin Bi4O5Br2 photocatalyst was prepared via a facile solvothermal method in the presence of reactable ionic liquid 1-hexadecyl-3-methylimidazolium bromide ([C16mim]Br) for the first time. FT-IR, XPS and TEM analysis results demonstrated the successful introduction of the 2D graphene-like g-C3N4 material to the Bi4O5Br2 system. DRS and BET analysis results indicated the existence of the g-C3N4 could lead to the broaden absorption edge and larger surface area of the ultrathin Bi4O5Br2 nanosheets. The electrochemical analysis implied a fast transfer of the interfacial electrons and low recombination rate of photogenerated charge carriers in g-C3N4/Bi4O5Br2, which could be assigned to the sufficient and tight contact between ultrathin Bi4O5Br2 and graphene-like g-C3N4. The quinolone antibiotic ciprofloxacin (CIP) was chosen as the target pollutant to evaluate the photocatalytic performance of the as-prepared samples under visible light irradiation. 1 wt% g-C3N4/Bi4O5Br2 composite exhibited the highest photocatalytic degradation performance among all of the as-prepared photocatalysts. The enhancement of photocatalytic activity was attributed to the maximum contact between graphene-like g-C3N4 and ultrathin Bi4O5Br2 material with matched energy band structure, which enable the efficient charge seperation. A possible photocatalytic mechanism also was proposed.

Relationship between post-SARS osteonecrosis and PAI-1 4G/5G gene polymorphisms.

PubMed

Sun, Wei; Li, Zirong; Shi, Zhengcai; Wang, Bailiang; Gao, Fuqiang; Yang, Yurun; Guo, Wanshou

2014-05-01

To explore the correlation between post-severe acute respiratory symptom (SARS) patients with osteonecrosis, investigate the etiology of post-SARS osteonecrosis and select the sensitive molecular symbols for early diagnosis and distinguish the high-risk population. The studied subjects were divided into two groups. Sixty-two post-SARS patients with osteonecrosis were one group, and 52 age- and sex-matched healthy people were as normal controlled group. Empty stomach blood samples from cubital veins were collected from both groups. Plasminogen activator inhibitor (PAI) by means of enzyme-linked immunosorbent assay and PAI-1 4G/5G polymorphism was detected by polymerase chain reaction and solid phase oligonucleotide assay. The blood agents of post-SARS patients changed obviously with 15.64 ± 13.85 U/ml while the control group 7.96 ± 4.27 U/ml; 4G/4G genotype for the PAI-1 polymorphism detected in post-SARS group was more than that of the control group, but had no statistical significance. The plasma PAI activity was related to homozygote 4G/4G genotype. This reveals that homozygote 4G/4G genotype may be a susceptible gene mark to Chinese osteonecrosis patients. Plasminogen activator inhibitor-1 is sensitive blood symbol for screening high-risk susceptible population; 4G/4G PAI-1 genotype may be an etiological factor in osteonecrosis.

Advances to G3

NASA Astrophysics Data System (ADS)

Salters, Vincent; Tarduno, John; van Keken, Peter

2008-12-01

Geochemistry, Geophysics, Geosystems (G3 ), a joint publication of AGU and the Geochemical Society, publishes research papers that speak to a broad community interested in Earth processes that are best studied with interdisciplinary approaches. G3 publishes conventional papers but is especially interested in novel publication forms that take advantage of electronic formats, such as animations and readily reusable digitized data sets. G3 's large number of submissions and subscriptions attests to how an interdisciplinary approach and electronic format benefit authors and readers. In the past few months, G3 has undergone substantial improvements. These include several changes in the timeliness of publication, revised protocols for the publication of data sets, the appointment of new associate editors, an updated Web site, and improved access to articles. As the editors of G3 , we are confident that these improvements will better serve AGU members.

Thermal formation effect of g-C3N4 structure on the visible light driven photocatalysis of g-C3N4/NiTiO3 Z-scheme composite photocatalysts

NASA Astrophysics Data System (ADS)

Pham, Thanh-Truc; Shin, Eun Woo

2018-07-01

The development of efficient visible-light driven photocatalysts has attracted considerable attention in environmental protection and remediation. In this study, the facile thermal polymerization of dicyandiamide (DCDA) to graphitic carbon nitride (g-C3N4) in the presence of nickel titanium trioxide (NiTiO3) was investigated for fabricating g-C3N4 and NiTiO3 composite (CNT) photocatalysts to understand the influence of the presence of NiTiO3 on the thermal formation of g-C3N4 layers from DCDA and to find an optimal processing temperature for fabricating CNT photocatalysts. To examine the effect of NiTiO3 on the fabrication of CNT photocatalysts, a gas phase environment (flowing air or nitrogen) and different processing temperatures were employed as preparation variables to control the properties of the CNT photocatalysts. In addition, the CNT photocatalysts were applied for the visible light driven photocatalytic degradation of methylene blue to evaluate their photocatalytic performances. The CNT photocatalyst prepared at T = 500 °C showed the highest photocatalytic activity, which was caused by the optimal morphology of g-C3N4 in the composite photocatalysts. The NiTiO3 inorganic phase in the composite photocatalysts acted as a catalyst to accelerate the thermal polymerization to form the g-C3N4 structure and as a promoter to increase the photocatalytic activity during photodegradation.

Double Z-scheme ZnO/ZnS/g-C3N4 ternary structure for efficient photocatalytic H2 production

NASA Astrophysics Data System (ADS)

Dong, Zhifang; Wu, Yan; Thirugnanam, Natarajan; Li, Gonglin

2018-02-01

In the present work, a novel ZnO/ZnS/g-C3N4 ternary nanocomposite with double Z-scheme heterojunction has been designed via a two-step facile chemical conversion route. The spherical ZnS nanoparticles were uniformly loaded onto ZnO nanoflowers surface. And then the ZnO/ZnS nanocomposite was further hybridized with g-C3N4 nanosheets. Ternary ZnO/ZnS/g-C3N4 nanocomposite displays the largest specific surface area (about 76.2 m2/g), which provides plentiful activated sites for photocatalytic reaction. Furthermore, the ternary material exhibits the highest methylene blue photodegradation rate of about 0.0218 min-1 and the optimum photocatalytic H2 production (1205 μmol/g) over water splitting at 4 h under solar light irradiation. Moreover, it showed the highest photocurrent effect and the minimum charge-transfer resistance. These results implied that the higher photoactivity of ZnO/ZnS/g-C3N4 nanocomposite could be attributed to the multi-steps charge transfer and effective electron-hole separation in the double Z-scheme system.

78 FR 958 - Certain Wireless Devices With 3G and/or 4G Capabilities and Components Thereof Notice of Receipt...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-07

... INTERNATIONAL TRADE COMMISSION [DN 2929] Certain Wireless Devices With 3G and/or 4G Capabilities... Interest AGENCY: U.S. International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that the U.S. International Trade Commission has received a complaint entitled Certain Wireless Devices...

A case of non-lacrimal immunoglobulin G4 (IgG4)-related orbital disease with mastitis.

PubMed

Farooq, Tahir Ali; Mudhar, Hardeep; Sandramouli, S

2016-01-01

IgG4-related orbital disease is a recognised cause for orbital inflammation. As its awareness increases and diagnostic accuracy improves there will be an increased number of cases being identified. This unique case demonstrates for the first time, with histological evidence, a case of a non-lacrimal IgG4-related orbital disease with concurrent IgG4-related mastitis. We describe a 47 year old who presented with a supraorbital swelling and mass. This was initially successfully treated with oral steroids and was later excised on recurrence. Immunohistochemical and blood serum analysis confirmed IgG4-related orbital disease. On systemic enquiry she was found to have a mass of the breast, which was shown to be IgG4-related mastitis. She is currently asymptomatic with no sign of recurrence and is under long-term surveillance. This case highlights the importance of systemic work up in patients presenting with orbital foci of IgG4 disease.

BPS states in N = 2 supersymmetric G2 and F4 models

NASA Astrophysics Data System (ADS)

Ahl Laamara, R.; Mellal, O.; Saidi, E. H.

2017-07-01

In BPS quiver theory of N = 2 supersymmetric pure gauge models with gauge invariance G, primitive BPS quivers Q0G are of two types: Q0ADE and Q0BCFG. In this study, we first show that Q0ADE have outer-automorphism symmetries inherited from the outer-automorphisms of the Dynkin diagrams of ADE Lie algebras. Then, we extend the usual folding operation of Dynkin diagrams ADE → BCFG to obtain the two following things: (i) relate Q0BCFG quivers and their mutations to the Q0ADE ones and their mutations; and (ii) link the BPS chambers of the N = 2ADE theories with the corresponding BCFG ones. As an illustration of this construction, we derive the BPS and anti-BPS states of the strong chambers QstgG2 and QstgF4 of the 4d N = 2 pure G2 and F4 gauge models.

Selective Cytotoxicity of 1,3,4-Thiadiazolium Mesoionic Derivatives on Hepatocarcinoma Cells (HepG2)

PubMed Central

Valdameri, Glaucio; Rocha, Maria Eliane Merlin; Martinez, Glaucia Regina; Noleto, Guilhermina Rodrigues; Acco, Alexandra; Alves de Souza, Carlos Eduardo; Echevarria, Aurea; Moretto dos Reis, Camilla; Di Pietro, Attilio; Suter Correia Cadena, Sílvia Maria

2015-01-01

In this work, we evaluated the cytotoxicity of mesoionic 4-phenyl-5-(2-Y, 4-X or 4-X-cinnamoyl)-1,3,4-thiadiazolium-2-phenylamine chloride derivatives (MI-J: X=OH, Y=H; MI-D: X=NO2, Y=H; MI-4F: X=F, Y=H; MI-2,4diF: X=Y=F) on human hepatocellular carcinoma (HepG2), and non-tumor cells (rat hepatocytes) for comparison. MI-J, M-4F and MI-2,4diF reduced HepG2 viability by ~ 50% at 25 μM after 24-h treatment, whereas MI-D required a 50 μM concentration, as shown by 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyltetrazolium bromide assays. The cytotoxicity was confirmed with lactate dehydrogenase assay, of which activity was increased by 55, 24 and 16% for MI-J, MI-4F and MI-2,4diF respectively (at 25 μM after 24 h). To identify the death pathway related to cytotoxicity, the HepG2 cells treated by mesoionic compounds were labeled with both annexin V and PI, and analyzed by flow cytometry. All compounds increased the number of doubly-stained cells at 25 μM after 24 h: by 76% for MI-J, 25% for MI-4F and MI-2,4diF, and 11% for MI-D. It was also verified that increased DNA fragmentation occurred upon MI-J, MI-4F and MI-2,4diF treatments (by 12%, 9% and 8%, respectively, at 25 μM after 24 h). These compounds were only weakly, or not at all, transported by the main multidrug transporters, P-glycoprotein, ABCG2 and MRP1, and were able to slightly inhibit their drug-transport activity. It may be concluded that 1,3,4-thiadiazolium compounds, especially the hydroxy derivative MI-J, constitute promising candidates for future investigations on in-vivo treatment of hepatocellular carcinoma. PMID:26083249

Synergetic effect of Ti 3+ and oxygen doping on enhancing photoelectrochemical and photocatalytic properties of TiO 2/g-C 3N 4 heterojunctions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Kai; Huang, Zhenyu; Zeng, Xiaoqiao

To improve the utilization of visible light and reduce photogenerated electron/hole recombination, Ti 3+ self-doped TiO 2/oxygen-doped graphitic carbon nitride (Ti 3+-TiO 2/O-g-C 3N 4) heterojunctions were prepared via hydrothermal treatment of a mixture of g-C 3N 4 and titanium oxohydride sol obtained from the reaction of TiH 2 with H 2O 2. In this way, exfoliated O-g-C 3N 4 and Ti 3+-TiO 2 nanoparticles were obtained. Simultaneously, strong bonding was formed between Ti 3+-TiO 2 nanoparticles and exfoliated O-g-C 3N 4 during the hydrothermal process. Charge transfer and recombination processes were characterized by transient photocurrent responses, electrochemical impedance test,more » and photoluminescence spectroscopy. The photocatalytic performances were investigated through rhodamine B degradation test under an irradiation source based on 30 W cold visible-light-emitting diode. The highest visible-light photoelectrochemical and photocatalytic activities were observed from the heterojunction with 1:2 mass ratio of Ti 3+-TiO 2 to O-g-C 3N 4. The photodegradation reaction rate constant based on this heterojuction is 0.0356 min -1, which is 3.87 and 4.56 times higher than those of pristine Ti 3+-TiO 2 and pure g-C 3N 4, respectively. Here, the remarkably high photoelectrochemical and photocatalytic performances of the heterojunctions are mainly attributed to the synergetic effect of efficient photogenerated electron-hole separation, decreased electron transfer resistance from interfacial chemical hydroxy residue bonds, and oxidizing groups originating from Ti 3+-TiO 2 and O-g-C 3N 4.« less

Synergetic Effect of Ti3+ and Oxygen Doping on Enhancing Photoelectrochemical and Photocatalytic Properties of TiO2/g-C3N4 Heterojunctions.

PubMed

Li, Kai; Huang, Zhenyu; Zeng, Xiaoqiao; Huang, Baibiao; Gao, Shanmin; Lu, Jun

2017-04-05

To improve the utilization of visible light and reduce photogenerated electron/hole recombination, Ti 3+ self-doped TiO 2 /oxygen-doped graphitic carbon nitride (Ti 3+ -TiO 2 /O-g-C 3 N 4 ) heterojunctions were prepared via hydrothermal treatment of a mixture of g-C 3 N 4 and titanium oxohydride sol obtained from the reaction of TiH 2 with H 2 O 2 . In this way, exfoliated O-g-C 3 N 4 and Ti 3+ -TiO 2 nanoparticles were obtained. Simultaneously, strong bonding was formed between Ti 3+ -TiO 2 nanoparticles and exfoliated O-g-C 3 N 4 during the hydrothermal process. Charge transfer and recombination processes were characterized by transient photocurrent responses, electrochemical impedance test, and photoluminescence spectroscopy. The photocatalytic performances were investigated through rhodamine B degradation test under an irradiation source based on 30 W cold visible-light-emitting diode. The highest visible-light photoelectrochemical and photocatalytic activities were observed from the heterojunction with 1:2 mass ratio of Ti 3+ -TiO 2 to O-g-C 3 N 4 . The photodegradation reaction rate constant based on this heterojuction is 0.0356 min -1 , which is 3.87 and 4.56 times higher than those of pristine Ti 3+ -TiO 2 and pure g-C 3 N 4 , respectively. The remarkably high photoelectrochemical and photocatalytic performances of the heterojunctions are mainly attributed to the synergetic effect of efficient photogenerated electron-hole separation, decreased electron transfer resistance from interfacial chemical hydroxy residue bonds, and oxidizing groups originating from Ti 3+ -TiO 2 and O-g-C 3 N 4 .

Synergetic effect of Ti 3+ and oxygen doping on enhancing photoelectrochemical and photocatalytic properties of TiO 2/g-C 3N 4 heterojunctions

DOE PAGES

Li, Kai; Huang, Zhenyu; Zeng, Xiaoqiao; ...

2017-03-07

To improve the utilization of visible light and reduce photogenerated electron/hole recombination, Ti 3+ self-doped TiO 2/oxygen-doped graphitic carbon nitride (Ti 3+-TiO 2/O-g-C 3N 4) heterojunctions were prepared via hydrothermal treatment of a mixture of g-C 3N 4 and titanium oxohydride sol obtained from the reaction of TiH 2 with H 2O 2. In this way, exfoliated O-g-C 3N 4 and Ti 3+-TiO 2 nanoparticles were obtained. Simultaneously, strong bonding was formed between Ti 3+-TiO 2 nanoparticles and exfoliated O-g-C 3N 4 during the hydrothermal process. Charge transfer and recombination processes were characterized by transient photocurrent responses, electrochemical impedance test,more » and photoluminescence spectroscopy. The photocatalytic performances were investigated through rhodamine B degradation test under an irradiation source based on 30 W cold visible-light-emitting diode. The highest visible-light photoelectrochemical and photocatalytic activities were observed from the heterojunction with 1:2 mass ratio of Ti 3+-TiO 2 to O-g-C 3N 4. The photodegradation reaction rate constant based on this heterojuction is 0.0356 min -1, which is 3.87 and 4.56 times higher than those of pristine Ti 3+-TiO 2 and pure g-C 3N 4, respectively. Here, the remarkably high photoelectrochemical and photocatalytic performances of the heterojunctions are mainly attributed to the synergetic effect of efficient photogenerated electron-hole separation, decreased electron transfer resistance from interfacial chemical hydroxy residue bonds, and oxidizing groups originating from Ti 3+-TiO 2 and O-g-C 3N 4.« less

Hierarchical Cu2O foam/g-C3N4 photocathode for photoelectrochemical hydrogen production

NASA Astrophysics Data System (ADS)

Ma, Xinzhou; Zhang, Jingtao; Wang, Biao; Li, Qiuguo; Chu, Sheng

2018-01-01

Solar photoelectrochemical (PEC) hydrogen production is a promising way for solving energy and environment problems. Earth-abundant Cu2O is a potential light absorber for PEC hydrogen production. In this article, hierarchical porous Cu2O foams are prepared by thermal oxidation of the electrochemically deposited Cu foams. PEC performances of the Cu2O foams are systematically studied and discussed. Benefiting from their higher light harvesting and more efficient charge separation, the Cu2O foams demonstrate significantly enhanced photocurrents and photostability compared to their film counterparts. Moreover, by integrating g-C3N4, hierarchical Cu2O foam/g-C3N4 composites are prepared with further improved photocurrent and photostability, appearing to be potential photocathodes for solar PEC hydrogen production. This study may provide a new and useful insight for the development of Cu2O-based photocathodes for PEC hydrogen production.

Potential energy and dipole moment surfaces of the triplet states of the O2(X3Σg-) - O2(X3Σg-,a1Δg,b1Σg+) complex

NASA Astrophysics Data System (ADS)

Karman, Tijs; van der Avoird, Ad; Groenenboom, Gerrit C.

2017-08-01

We compute four-dimensional diabatic potential energy surfaces and transition dipole moment surfaces of O2-O2, relevant for the theoretical description of collision-induced absorption in the forbidden X3Σg- → a1Δg and X3Σg- → b1Σg+ bands at 7883 cm-1 and 13 122 cm-1, respectively. We compute potentials at the multi-reference configuration interaction (MRCI) level and dipole surfaces at the MRCI and complete active space self-consistent field (CASSCF) levels of theory. Potentials and dipole surfaces are transformed to a diabatic basis using a recent multiple-property-based diabatization algorithm. We discuss the angular expansion of these surfaces, derive the symmetry constraints on the expansion coefficients, and present working equations for determining the expansion coefficients by numerical integration over the angles. We also present an interpolation scheme with exponential extrapolation to both short and large separations, which is used for representing the O2-O2 distance dependence of the angular expansion coefficients. For the triplet ground state of the complex, the potential energy surface is in reasonable agreement with previous calculations, whereas global excited state potentials are reported here for the first time. The transition dipole moment surfaces are strongly dependent on the level of theory at which they are calculated, as is also shown here by benchmark calculations at high symmetry geometries. Therefore, ab initio calculations of the collision-induced absorption spectra cannot become quantitatively predictive unless more accurate transition dipole surfaces can be computed. This is left as an open question for method development in electronic structure theory. The calculated potential energy and transition dipole moment surfaces are employed in quantum dynamical calculations of collision-induced absorption spectra reported in Paper II [T. Karman et al., J. Chem. Phys. 147, 084307 (2017)].

Potential energy and dipole moment surfaces of the triplet states of the O2(X3Σg-) - O2(X3Σg-,a1Δg,b1Σg+) complex.

PubMed

Karman, Tijs; van der Avoird, Ad; Groenenboom, Gerrit C

2017-08-28

We compute four-dimensional diabatic potential energy surfaces and transition dipole moment surfaces of O 2 -O 2 , relevant for the theoretical description of collision-induced absorption in the forbidden X 3 Σ g -  → a 1 Δ g and X 3 Σ g -  → b 1 Σ g + bands at 7883 cm -1 and 13 122 cm -1 , respectively. We compute potentials at the multi-reference configuration interaction (MRCI) level and dipole surfaces at the MRCI and complete active space self-consistent field (CASSCF) levels of theory. Potentials and dipole surfaces are transformed to a diabatic basis using a recent multiple-property-based diabatization algorithm. We discuss the angular expansion of these surfaces, derive the symmetry constraints on the expansion coefficients, and present working equations for determining the expansion coefficients by numerical integration over the angles. We also present an interpolation scheme with exponential extrapolation to both short and large separations, which is used for representing the O 2 -O 2 distance dependence of the angular expansion coefficients. For the triplet ground state of the complex, the potential energy surface is in reasonable agreement with previous calculations, whereas global excited state potentials are reported here for the first time. The transition dipole moment surfaces are strongly dependent on the level of theory at which they are calculated, as is also shown here by benchmark calculations at high symmetry geometries. Therefore, ab initio calculations of the collision-induced absorption spectra cannot become quantitatively predictive unless more accurate transition dipole surfaces can be computed. This is left as an open question for method development in electronic structure theory. The calculated potential energy and transition dipole moment surfaces are employed in quantum dynamical calculations of collision-induced absorption spectra reported in Paper II [T. Karman et al., J. Chem. Phys. 147, 084307 (2017)].

Measuring the performance of G2G services in Iran

NASA Astrophysics Data System (ADS)

Zarei, Behrouz; Safdari, Maryam

To highlight the growth of e-government and the importance of its services it is essential to evaluate the performance of the service delivery to customers. Research indicates that traditional performance indexes are not suitable for this evaluation; moreover, it is noticeable that the e-government services are intangible and invisible. Among different e-government services, measurement of quality government to government (G2G) services has been less attractive for researchers while crucial for government policy-makers. This calls for a better understanding of the specific needs of users of these services in order to provide appropriate type and level of services that meets those needs. In this paper, the performance of the G2G services is measured in the Iranian context. For this purpose, SERVQUAL, which is a well-known method for assessing service quality, is employed. This study proposes and tests a five-factor of SERVQUAL instrument to explain user satisfaction and gap analysis, between expectations and perceptions of its customers, consisting thirty ministries and main governmental organizations. Based on a Chi-square test, factor analysis, gap analysis and correlations, it is concluded the gap between expectations and perceptions of G2G customers is significant and customer satisfaction of G2G services is at low level.

4G/5G and A-844G Polymorphisms of Plasminogen Activator Inhibitor-1 Associated with Glioblastoma in Iran--a Case-Control Study.

PubMed

Pooyan, Honari; Ahmad, Ebrahimi; Azadeh, Rakhshan

2015-01-01

Glioblastoma is a highly aggressive and malignant brain tumor. Risk factors are largely unknown however, although several biomarkers have been identified which may support development, angiogenesis and invasion of tumor cells. One of these biomarkers is PAI-1. 4G/5G and A-844G are two common polymorphisms in the gene promotor of PAI 1 that may be related to high transcription and expression of this gene. Studies have shown that the prevalence of the 4G and 844G allele is significantly higher in patients with some cancers and genetic disorders. We here assessed the association of 4G/5G and A-844G polymorphisms with glioblastoma cancer risk in Iranians in a case-control study. All 71 patients with clinically confirmed and 140 volunteers with no history and symptoms of glioblastoma as control group were screened for 4G/5G and A-844G polymorphisms of PAI-1, using ARMS-PCR. Genotype and allele frequencies of case and control groups were analyzed using the DeFinetti program. Our results showed significant associations between 4G/5G (p=0.01824) and A-844G (p=0.02012) polymorphisms of the PAI-1 gene with glioblastoma cancer risk in our Iranian population. The results of this study supporting an association of the PAI-1 4G/5G (p=0.01824) and A-844G (p=0.02012) polymorphisms with increasing glioblastoma cancer risk in Iranian patients.

Calcination Method Synthesis of SnO2/g-C3N4 Composites for a High-Performance Ethanol Gas Sensing Application

PubMed Central

Cao, Jianliang; Qin, Cong; Wang, Yan; Zhang, Bo; Gong, Yuxiao; Zhang, Huoli; Sun, Guang; Bala, Hari; Zhang, Zhanying

2017-01-01

The SnO2/g-C3N4 composites were synthesized via a facile calcination method by using SnCl4·5H2O and urea as the precursor. The structure and morphology of the as-synthesized composites were characterized by the techniques of X-ray diffraction (XRD), the field-emission scanning electron microscopy and transmission electron microscopy (SEM and TEM), energy dispersive spectrometry (EDS), thermal gravity and differential thermal analysis (TG-DTA), and N2-sorption. The analysis results indicated that the as-synthesized samples possess the two dimensional structure. Additionally, the SnO2 nanoparticles were highly dispersed on the surface of the g-C3N4nanosheets. The gas-sensing performance of the as-synthesized composites for different gases was tested. Moreover, the composite with 7 wt % g-C3N4 content (SnO2/g-C3N4-7) SnO2/g-C3N4-7 exhibits an admirable gas-sensing property to ethanol, which possesses a higher response and better selectivity than that of the pure SnO2-based sensor. The high surface area of the SnO2/g-C3N4 composite and the good electronic characteristics of the two dimensional graphitic carbon nitride are in favor of the elevated gas-sensing property. PMID:28468245

D1((2)B2g) to D0((2)Au) Fluorescence from the Matrix-Isolated Perylene Cation Following Laser Excitation into the D5(2)B3g) and D2 ((2)B3g) Electronic States

NASA Technical Reports Server (NTRS)

Chillier, Xavier D. F.; Stone, Bradley M.; Joblin, Christine; Salama, Farid; Allamandola, Louis J.; DeVincenzi, Donald L. (Technical Monitor)

2001-01-01

Fluorescence spectra of the perylene cation, pumped by direct laser excitation via the D(sub 2)((2)B(sub 3g)) (left arrow) D(sub 0)((2)A(sub u)) and D(sub 5)(2)B(sub 3g)) (left arrow) D(sub 0)((2)A(sub u)) transitions, are presented. Direct excitation into the D5 or D2 states is followed by rapid non-radiative relaxation to D1 that, in turn,relaxes radiatively. Excitation spectroscopy across the D(sub 2)((2)B(sub 3g)) (left arrow) D(sub 0)((2)A(sub u)) transition near 730 nm shows that site splitting plays little or no role in determining the spectral substructure in the ion spectra. Tentative assignments for ground state vibrational frequencies are made by comparison of spectral intervals with calculated normal mode frequencies.

Placental Malaria Induces Variant-Specific Antibodies of the Cytophilic Subtypes Immunoglobulin G1 (IgG1) and IgG3 That Correlate with Adhesion Inhibitory Activity

PubMed Central

Elliott, Salenna R.; Brennan, Amy K.; Beeson, James G.; Tadesse, Eyob; Molyneux, Malcolm E.; Brown, Graham V.; Rogerson, Stephen J.

2005-01-01

Antibodies targeting variant antigens on the surfaces of chondroitin sulfate A (CSA)-binding malaria-infected erythrocytes have been linked to protection against the complications of malaria in pregnancy. We examined the isotype/subtype profiles of antibodies that bound to variant surface antigens expressed by CSA-adherent Plasmodium falciparum in pregnant Malawian women with and without histologically defined placental malaria. Women in their first pregnancy with placental malaria produced significantly greater amounts of immunoglobulin G1 (IgG1) and IgG3 reactive with surface antigens of malaria-infected erythrocytes than uninfected women of the same gravidity. IgG1 and IgG3 levels in infected and control women in later pregnancies were similar to those in infected women in their first pregnancy. Levels of IgG2 and IgG4 were similarly low in infected and uninfected women of all gravidities. IgM that bound to the surface of CSA-adherent P. falciparum occurred in all groups of women and malaria-naïve controls. There was a significant correlation between IgG1 and IgG3 levels, indicating that women usually produced both subtypes. Levels of IgG1 and IgG3 correlated with the ability of serum or plasma to inhibit parasite adhesion to CSA. Taken together, these data suggest that IgG1 and IgG3 dominate the IgG response to placental-type variant surface antigens. They may function by blocking parasite adhesion to placental CSA, but given their cytophilic nature, they might also opsonize malaria-infected erythrocytes for interaction with Fc receptors on phagocytic cells. PMID:16113309

Room-temperature in situ fabrication of Bi2O3/g-C3N4 direct Z-scheme photocatalyst with enhanced photocatalytic activity

NASA Astrophysics Data System (ADS)

He, Rongan; Zhou, Jiaqian; Fu, Huiqing; Zhang, Shiying; Jiang, Chuanjia

2018-02-01

Constructing direct Z-scheme heterojunction is an effective approach to separating photogenerated charge carriers and improving the activity of semiconductor photocatalysts. Herein, a composite of bismuth(III) oxide (Bi2O3) and graphitic carbon nitride (g-C3N4) was in situ fabricated at room temperature by photoreductive deposition of Bi3+ and subsequent air-oxidation of the resultant metallic Bi. Quantum-sized ω-Bi2O3 nanoparticles approximately 6 nm in diameter were uniformly distributed on the surface of mesoporous g-C3N4. The as-prepared Bi2O3/g-C3N4 composite exhibited higher photocatalytic activity than pure Bi2O3 and g-C3N4 for photocatalytic degradation of phenol under visible light. Reactive species trapping experiments revealed that superoxide radicals and photogenerated holes played important roles in the photocatalytic degradation of phenol. The enhanced photocatalytic activity, identification of reactive species and higher rate of charge carrier recombination (as indicated by stronger photoluminescence intensity) collectively suggest that the charge migration within the Bi2O3/g-C3N4 composite followed a Z-scheme mechanism. Photogenerated electrons on the conduction band of Bi2O3 migrate to the valence band of g-C3N4 and combine with photogenerated holes therein. At the cost of these less reactive charge carriers, the Z-scheme heterojunction enables efficient charge separation, while preserving the photogenerated electrons and holes with stronger redox abilities, which is beneficial for enhanced photocatalytic activity.

G4RNA screener web server: User focused interface for RNA G-quadruplex prediction.

PubMed

Garant, Jean-Michel; Perreault, Jean-Pierre; Scott, Michelle S

2018-06-06

Though RNA G-quadruplexes became a focus of study over a decade ago, the main challenge associated with the identification of new potential G-quadruplexes remains a bottleneck step. It slows the study of these non-canonical structures in nucleic acids, and thus the understanding of their significance. The G4RNA screener is an accurate tool for the prediction of RNA G-quadruplexes but its deployment has brought to light an issue with its accessibility to G-quadruplex experts and biologists. G4RNA screener web server is a platform that provides a much needed interface to manage the input, parameters and result display of the main command-line ready tool. It is accessible at http://scottgroup.med.usherbrooke.ca/G4RNA_screener/. Copyright © 2018. Published by Elsevier B.V.

Plasminogen activator inhibitor-1 4G/5G gene polymorphism and primary open-angle glaucoma

PubMed Central

Weger, Martin; Faschinger, Christoph; Schmut, Otto; Renner, Wilfried

2008-01-01

Purpose Alterations of the plasmin system have been suggested to participate in the multifactorial pathogenesis of primary open-angle glaucoma (POAG). The main physiological inhibitor of the plasmin system is plasminogen activator inhibitor-1 (PAI-1), which leads to decreased degradation of extracellular material. Interestingly, elevated PAI-1 levels in the aqueous humor of patients with POAG have been reported. A common polymorphism within the promoter region (PAI-1 4G/5G) has previously been shown to reduce the gene transcription rate of PAI-1. The purpose of the present study was to investigate a hypothesized association between PAI-1 4G/5G and the presence of POAG in a Caucasian population. Methods The present case-control study comprised 212 unrelated patients with POAG and 212 healthy control subjects, matched for age and sex. Genotyping of PAI-1 4G/5G polymorphisms was done using polymerase chain reaction. Results Allelic frequencies and genotype distributions of PAI-1 4G/5G did not significantly differ between patients with POAG and control subjects (PAI-1 4G/5G: 29.7% versus 29.7%). Presence of the PAI-1 4G-allele was associated with a nonsignificant odds ratio of 0.98 (95% confidence interval: 0.74–1.30) for POAG. Conclusions Our data suggest that PAI-1 4G/5G itself is unlikely to be a major risk factor among Caucasian patients with POAG. PMID:18615155

Inactivation of Toluene 2-Monooxygenase in Burkholderia cepacia G4 by Alkynes

PubMed Central

Yeager, Chris M.; Bottomley, Peter J.; Arp, Daniel J.; Hyman, Michael R.

1999-01-01

High concentrations of acetylene (10 to 50% [vol/vol] gas phase) were required to inhibit the growth of Burkholderia cepacia G4 on toluene, while 1% (vol/vol) (gas phase) propyne or 1-butyne completely inhibited growth. Low concentrations of longer-chain alkynes (C5 to C10) were also effective inhibitors of toluene-dependent growth, and 2- and 3-alkynes were more potent inhibitors than their 1-alkyne counterparts. Exposure of toluene-grown B. cepacia G4 to alkynes resulted in the irreversible loss of toluene- and o-cresol-dependent O2 uptake activities, while acetate- and 3-methylcatechol-dependent O2 uptake activities were unaffected. Toluene-dependent O2 uptake decreased upon the addition of 1-butyne in a concentration- and time-dependent manner. The loss of activity followed first-order kinetics, with apparent rate constants ranging from 0.25 min−1 to 2.45 min−1. Increasing concentrations of toluene afforded protection from the inhibitory effects of 1-butyne. Furthermore, oxygen, supplied as H2O2, was required for inhibition by 1-butyne. These results suggest that alkynes are specific, mechanism-based inactivators of toluene 2-monooxygenase in B. cepacia G4, although the simplest alkyne, acetylene, was relatively ineffective compared to longer alkynes. Alkene analogs of acetylene and propyne—ethylene and propylene—were not inactivators of toluene 2-monooxygenase activity in B. cepacia G4 but were oxidized to their respective epoxides, with apparent Ks and Vmax values of 39.7 μM and 112.3 nmol min−1 mg of protein−1 for ethylene and 32.3 μM and 89.2 nmol min−1 mg of protein−1 for propylene. PMID:9925593

IgG2 deficiency in sickle cell anaemia.

PubMed

Natta, C L; Outschoorn, I M

1984-08-01

8 patients with known sickle cell anaemia were studied immunologically. The concentrations of the main immunoglobulin classes, IgG and IgA, were significantly higher than the levels in 11 normal age- and sex-matched black subjects (P less than 0.01). IgM levels were not significantly different in the two groups. There was a heterogeneity in the interaction of the IgG subclasses with Protein A, with low levels of IgG2. The IgG2:IgG1 ratios varied from 1:3.8 to 1:6 (normals 1:3). In 4 patients the absolute levels of IgG2 as measured by radial immunodiffusion were lower than normal, thus confirming the chromatographic ratios. Since specific antibody is often restricted to a single subclass, the levels of IgG subclasses may be related to recurrent bacterial infections in these patients.

Plasminogen Activator Inhibitor-1 4G/5G Polymorphism is Associated with Reproductive Failure: Metabolic, Hormonal, and Immune Profiles.

PubMed

Salazar Garcia, Maria D; Sung, Nayoung; Mullenix, Thomas M; Dambaeva, Svetlana; Beaman, Kenneth; Gilman-Sachs, Alice; Kwak-Kim, Joanne

2016-07-01

Association between PAI-1 4G/5G polymorphism and reproductive failures has been postulated. We aimed to investigate its impact on metabolic, hormonal, and immune profiles of women with reproductive failures. A retrospective study was carried out in 208 women with a history of reproductive failure. Study patients were divided into three groups: women with repeated implantation failure (RIF, n = 40), recurrent pregnancy loss (RPL, n = 113), and both RIF and RPL (n = 55). Fertile controls were 92. PAI-1 4G/4G was prevalent in RPL, RIF, and RIF/RPL groups when compared with controls (P = 0.003) and associated with increased risks of RIF, RPL, and RIF with RPL (OR = 4.5, 2.2 and 2.7). Women with PAI-1 4G/4G have significantly higher BMI, glucose, and PAI-1 levels and lower NK cytotoxicity when compared with women without PAI-1 4G/4G. PAI-1 4G/5G polymorphism plays a major role in the pathogenesis of RPL and RIF by altering metabolic and immunological profiles. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

An evaluation of the rate of absorption of solar radiation in the O2(X3Sigma-g - b1Sigma-g) transition

NASA Technical Reports Server (NTRS)

Mlynczak, Martin G.

1993-01-01

The rate at which molecular oxygen absorbs radiation in the O2(X3Sigma-g - b1Sigma-g) transition is calculated using a line-by-line radiative transfer model. This rate is critical to the determination of the population of the O2(b1Sigma-g) state required for studies of the O2(b1Sigma-g - X3Sigma-g) dayglow, the O2(a1Delta-g - X3Sigma-g) dayglow, and possibly the rates of oxidation of H2 and N2O. Previous evaluations of this rate (which is sometimes called the g-factor) have significantly overestimated its value. The rate is tabulated as a function of altitude, pressure, and solar zenith angle.

Associations of maternal PLA2G4C and PLA2G4D polymorphisms with the risk of spontaneous preterm birth in a Chinese population

PubMed Central

Liu, Guang-Jian; He, Jian-Rong; Kuang, Ya-Shu; Fan, Xue-Jiao; Li, Wei-Dong; Lu, Jin-Hua; Xia, Xiao-Yan; Liu, Xiao-Dan; Chen, Nian-Nian; Mai, Wei-Bi; Xia, Hui-Min; Qiu, Xiu

2017-01-01

Preterm birth is the leading cause of mortality and morbidity in infants. Its etiology is multifactorial with genes and immune homeostasis. The authors investigated whether prostaglandin (PG) synthesis related single nucleotide polymorphisms (SNPs) PLA2G4C rs1366442 and PLA2G4D rs4924618 were associated with the risk of spontaneous preterm birth (SPTB) in a Chinese population of 114 cases of SPTB and 250 controls of term delivery. The risk associations were determined by odds ratios (ORs) and their 95% confidence intervals (CIs) calculated using multivariate logistic regression. Homology modeling was performed to elucidate potential mechanism of the SNP function. The maternal AT/TT genotype of PLA2G4D rs4924618 was associated with a reduced risk of SPTB (OR, 0.61; 95% CI, 0.37–0.99), while no significant association between PLA2G4C rs1366442 and SPTB risk was identified. Structure and sequence analysis revealed that the amino acid substitution introduced by this SNP located at the conserved central core of the catalytic domain of cytosolic phospholipase A2 δ and was close to the active site. These findings suggested that the polymorphism of PLA2G4D rs4924618 may have a protective influence on the SPTB susceptibility in a Chinese population, supporting a role for genetics in the association between PG synthesis and preterm birth. PMID:28440406

Computational study on the half-metallicity in transition metal—oxide-incorporated 2D g-C3N4 nanosheets

NASA Astrophysics Data System (ADS)

Gao, Qian; Wang, Hui-Li; Zhang, Li-Fu; Hu, Shuang-Lin; Hu, Zhen-Peng

2018-06-01

In this study, based on the first-principles calculations, we systematically investigated the electronic and magnetic properties of the transition metal-oxide-incorporated 2D g-C3N4 nanosheet (labeled C3N4-TM-O, TM = Sc-Mn). The results suggest that the TM-O binds to g-C3N4 nanosheets strongly for all systems. We found that the 2D C3N4-TM-O framework is ferromagnetic for TM = Sc, Ti, V, Cr, while it is antiferromagnetic for TM = Mn. All the ferromagnetic systems exhibit the half-metallic property. Furthermore, Monte Carlo simulations based on the Heisenberg model suggest that the Curie temperatures ( T c ) of the C3N4-TM-O (TM = Sc, Ti, V, Cr) framework are 169 K, 68 K, 203 K, and 190 K, respectively. Based on Bader charge analysis, we found that the origin of the half-metallicity at Fermi energy can be partially attributed to the transfer of electrons from TM atoms to the g-C3N4 nanosheet. In addition, we found that not only electrons but also holes can induce half-metallicity for 2D g-C3N4 nanosheets, which may help to understand the origin of half-metallicity for graphitic carbon nitride.

Fabrication of flower-like direct Z-scheme β-Bi2O3/g-C3N4 photocatalyst with enhanced visible light photoactivity for Rhodamine B degradation

NASA Astrophysics Data System (ADS)

Zhang, Liping; Wang, Guohong; Xiong, Zhenzhong; Tang, Hua; Jiang, Chuanjia

2018-04-01

A combined hydrothermal-calcination approach is developed to synthesize hierarchical β-Bi2O3/g-C3N4 direct Z-scheme photocatalyst with enhanced visible light photoactivity for Rhodamine B (RhB) degradation. First, Bi2O2CO3 microflowers were hydrothermally prepared using Bi(NO3)3·5H2O as feedstocks, and then a series of β-Bi2O3/g-C3N4 direct Z-scheme photocatalysts were synthesized via a facile calcination method using Bi2O2CO3 and g-C3N4 as precursors. The samples were systematically characterized by various characterization technologies including X-ray diffraction, scanning and transmission electron microscopes, Fourier transform infrared spectroscopy and N2 absorption-desorption equipment. It was found that the g-C3N4 content in the precursors played a key role in affecting the photocatalytic activity of the final products. The β-Bi2O3/g-C3N4 heterojunction exhibited higher photocatalytic activity than single active components (β-Bi2O3 and g-C3N4), indicating the presence of a synergistic effect between two active components in β-Bi2O3/g-C3N4 heterojunction. Among all as-prepared catalysts, the 70 wt.% g-C3N4/Bi2O2CO3 exhibits the highest activity for RhB degradation, and the apparent reaction rate constant k (42.2 × 10-3 min-1) is 3.1 and 1.7 times as high as that of pure β-Bi2O3 (13.5 × 10-3 min-1) and g-C3N4 (25.2 × 10-3 min-1), respectively. The enhanced photocatalytic performance of β-Bi2O3/g-C3N4 heterostructure photocatalysts is mainly due to the high surface area, closely contacted interfaces between the β-Bi2O3 and g-C3N4 component, and the formation of direct Z-scheme structure in the β-Bi2O3/g-C3N4 composites.

Cycle control and bleeding pattern of a 24/4 regimen of drospirenone 3 mg/ethinylestradiol 20 μg compared with a 21/7 regimen of desogestrel 150 μg/ethinylestradiol 20 μg: a pooled analysis.

PubMed

Anttila, Leena; Neunteufel, Walter; Petraglia, Felice; Marr, Joachim; Kunz, Michael

2011-01-01

The degree of cycle control achieved with a hormonal contraceptive method is an important determinant of its acceptance and continuation. This study set out to compare the cycle control and bleeding profile of drospirenone (DRSP) 3 mg/ethinylestradiol (EE) 20 μg in a 24-active pill/4-inert pill (24/4) regimen (YAZ®) with those of desogestrel (DSG) 150 μg/EE 20 μg in a 21/7 regimen (Mercilon®), an established European combined oral contraceptive (COC). Bleeding data from women aged 17-36 years who received either DRSP 3 mg/EE 20 μg in a 24/4 regimen (n = 1285) or DSG 150 μg/EE 20 μg in a 21/7 regimen (n = 471) during four clinical studies were pooled and analysed over seven treatment cycles. The maximum intensity of scheduled withdrawal bleeding was 'normal bleeding' for >50% of subjects in cycles 1-6 in both treatment groups. Moreover, the incidence of unscheduled intracyclic bleeding during cycles 2-7 was comparable between treatment types (10.2-14.9% in women treated with DRSP 3 mg/EE 20 μg 24/4 vs 8.6-13.8% in women treated with DSG 150 μg/EE 20 μg 21/7). Overall, similar bleeding patterns were observed with both treatments. DRSP 3 mg/EE 20 μg 24/4 is associated with a bleeding profile and cycle control that is comparable to that of an established, low-dose COC formulation.

Molecular Characterization of Echinococcus granulosus Cysts in North Indian Patients: Identification of G1, G3, G5 and G6 Genotypes

PubMed Central

Sharma, Monika; Sehgal, Rakesh; Fomda, Bashir Ahmad; Malhotra, Anil; Malla, Nancy

2013-01-01

Background Cystic echinococcosis (CE) caused by the Echinococcus granulosus, is a major public health problem worldwide, including India. The different genotypes of E. granulosus responsible for human hydatidosis have been reported from endemic areas throughout the world. However, the genetic characterization of E. granulosus infecting the human population in India is lacking. The aim of study was to ascertain the genotype(s) of the parasite responsible for human hydatidosis in North India. Methodology/Principal Findings To study the transmission patterns of E. granulosus, genotypic analysis was performed on hydatid cysts obtained from 32 cystic echinococcosis (CE) patients residing in 7 different states of North India. Mitochondrial cytochrome c oxidase subunit1 (cox1) sequencing was done for molecular identification of the isolates. Most of the CE patients (30/32) were found to be infected with hydatid cyst of either G3 (53.1%) or G1 (40.62%) genotype and one each of G5 (cattle strain) and G6 (camel strain) genotype. Conclusions/Significance These findings demonstrate the zoonotic potential of G1 (sheep strain) and G3 (buffalo strain) genotypes of E. granulosus as these emerged as predominant genotypes infecting the humans in India. In addition to this, the present study reports the first human CE case infected with G5 genotype (cattle strain) in an Asian country and presence of G6 genotype (camel strain) in India. The results may have important implications in the planning of control strategies for human hydatidosis. PMID:23785531

g-C3N4/NiAl-LDH 2D/2D Hybrid Heterojunction for High-Performance Photocatalytic Reduction of CO2 into Renewable Fuels.

PubMed

Tonda, Surendar; Kumar, Santosh; Bhardwaj, Monika; Yadav, Poonam; Ogale, Satishchandra

2018-01-24

2D/2D interface heterostructures of g-C 3 N 4 and NiAl-LDH are synthesized utilizing strong electrostatic interactions between positively charged 2D NiAl-LDH sheets and negatively charged 2D g-C 3 N 4 nanosheets. This new 2D/2D interface heterojunction showed remarkable performance for photocatalytic CO 2 reduction to produce renewable fuels such as CO and H 2 under visible-light irradiation, far superior to that of either single phase g-C 3 N 4 or NiAl-LDH nanosheets. The enhancement of photocatalytic activity could be attributed mainly to the excellent interfacial contact at the heterojunction of g-C 3 N 4 /NiAl-LDH, which subsequently results in suppressed recombination, and improved transfer and separation of photogenerated charge carriers. In addition, the optimal g-C 3 N 4 /NiAl-LDH nanocomposite possessed high photostability after successive experimental runs with no obvious change in the production of CO from CO 2 reduction. Our findings regarding the design, fabrication and photophysical properties of 2D/2D heterostructure systems may find use in other photocatalytic applications including H 2 production and water purification.

Carbon/CuO nanosphere-anchored g-C3N4 nanosheets as ternary electrode material for supercapacitors

NASA Astrophysics Data System (ADS)

Vattikuti, S. V. Prabhakar; Reddy, B. Purusottam; Byon, Chan; Shim, Jaesool

2018-06-01

Novel electrode materials for supercapacitors comprised of carbon and copper oxide (CuO) nanospheres on graphitic carbon nitride (g-C3N4) nanosheets, denoted as C/CuO@g-C3N4 are self-assembled via a one-step co-pyrolysis decomposition method. The pure g-C3N4 and C/CuO@g-C3N4 were confirmed by powder X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), thermal gravimetric and differential thermal analysis (TG-DTA), X-ray photoelectron spectroscopy (XPS), N2 adsorption/desorption studies and Fourier-transform infrared spectroscopy (FTIR). The specific capacitance was 247.2 F g-1 in 0.5 M NaOH at a current density of 1 A g-1, and more than 92.1% of the capacitance was retained after 6000 cycles. The property enhancement was ascribed to the synergistic effects of the three components in the composite. These results suggest that C/CuO@g-C3N4 possessed an excellent cyclic stability with respect to their capacity performance as electrode materials.

IgG4-related disease of the rectum

PubMed Central

Choi, Sung-Bong; Lim, Chul-Hyun; Cha, Myung-Guen

2016-01-01

IgG4-related disease is a relatively new disease entity characterized by elevated serum IgG4 levels and marked infiltration of IgG4-positive plasma cells in lesions. Organ enlargement or nodular lesions consisting of abundant infiltration of lymphocytes and IgG4-positive plasma cells and fibrosis are seen in various organs throughout. We encountered a patient with an inflammatory pseudotumor of the rectum, which was histopathologically confirmed to be an IgG4-related disease. The patient was a 28-year-old woman who had constipation for 3 months. The endoluminal ultrasonography showed a lesion that was heterogeneous and low echogenic in lower rectum. The result of colonoscopic biopsy findings was of chronic proctitis with lymphoid aggregates. For a confirmative diagnosis, excision was performed. Histopathological examination represented plasma cell infiltration and fibrosis. Immunohistochemistry revealed prominence of IgG4-positive plasma cells and confirmed the diagnosis of IgG4-related disease. The patient is currently under observation on low-dose oral prednisolone without relapse. PMID:27186575

Critical Elements of Vehicle-to-Grid (V2G) Economics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steward, Darlene M.

This report explores the critical elements of V2G economics. Section 2 summarizes the elements and costs of a V2G system. Section 3 describes V2G revenue-generating services and the business cases for providing these services. Section 4 notes real-world V2G applications. Section 5 lists concerns related to V2G. Section 6 concludes and summarizes V2G cost and revenue elements.

The Roles of APOBEC3G Complexes in the Incorporation of APOBEC3G into HIV-1

PubMed Central

Zhang, Quan; Liu, Zhenlong; Jia, Pingping; Zhou, Jinming; Guo, Fei; You, Xuefu; Yu, Liyan; Zhao, Lixun; Jiang, Jiandong; Cen, Shan

2013-01-01

Background The incorporation of human APOBEC3G (hA3G) into HIV is required for exerting its antiviral activity, therefore the mechanism underlying hA3G virion encapsidation has been investigated extensively. hA3G was shown to form low-molecular-mass (LMM) and high-molecular-mass (HMM) complexes. The function of different forms of hA3G in its viral incorporation remains unclear. Methodology/Principal Findings In this study, we investigated the subcellular distribution and lipid raft association of hA3G using subcellular fractionation, membrane floatation assay and pulse-chase radiolabeling experiments respectively, and studied the correlation between the ability of hA3G to form the different complex and its viral incorporation. Our work herein provides evidence that the majority of newly-synthesized hA3G interacts with membrane lipid raft domains to form Lipid raft-associated hA3G (RA hA3G), which serve as the precursor of mature HMM hA3G complex, while a minority of newly-synthesized hA3G remains in the cytoplasm as a soluble LMM form. The distribution of hA3G among the soluble LMM form, the RA LMM form and the mature forms of HMM is regulated by a mechanism involving the N-terminal part of the linker region and the C-terminus of hA3G. Mutagenesis studies reveal a direct correlation between the ability of hA3G to form the RA LMM complex and its viral incorporation. Conclusions/Significance Together these data suggest that the Lipid raft-associated LMM A3G complex functions as the cellular source of viral hA3G. PMID:24098356

Relationship of plasminogen activator inhibitor 1 gene 4G/5G polymorphisms to hypertension in Korean women.

PubMed

Kim, Kyu-nam; Kim, Kwang-min; Kim, Bom-taeck; Joo, Nam-seok; Cho, Doo-yeoun; Lee, Duck-joo

2012-04-01

Hypertension (HTN) is a major determinant of various cardiovascular events. Plasma levels of plasminogen activator inhibitor 1 (PAI-1) modulate this risk. A deletion/insertion polymorphism within the PAI-1 loci (4G/4G, 4G/5G, 5G/5G) affects the expression of this gene. The present study investigated the association between PAI-1 loci polymorphisms and HTN in Korean women. Korean women (n = 1312) were enrolled in this study to evaluate the association between PAI-1 4G/5G gene polymorphisms and HTN as well as other metabolic risk factors. PAI-1 loci polymorphisms were investigated using polymerase chain reaction amplification and single-strand conformation polymorphism analysis. The three genotype groups differed with respect to systolic blood pressure (P = 0.043), and diastolic blood pressure (P = 0.009) but not with respect to age, body mass index, total cholesterol, low or high density lipoprotein cholesterol, triglycerides, or fasting blood glucose. Carriers of the PAI-1 4G allele had more hypertension significantly (PAI-1 4G/5G vs. PAI-1 5G/5G, P = 0.032; PAI-1 4G/4G vs. PAI-1 5G/5G, P = 0.034). When stratified according to PAI-1 4G/5G polymorphism, there was no significant difference in all metabolic parameters among PAI-1 genotype groups in patients with HTN as well as subjects with normal blood pressure. The estimated odds ratio of the 4G/4G genotype and 4G/5G for HTN was 1.7 (P = 0.005), and 1.6 (P = 0.015), respectively. These findings might indicate that PAI-1 loci polymorphisms independently contribute to HTN and that gene-environmental interaction may be not associated in Korean women.

Mitochondrial-dependent Autoimmunity in Membranous Nephropathy of IgG4-related Disease

PubMed Central

Buelli, Simona; Perico, Luca; Galbusera, Miriam; Abbate, Mauro; Morigi, Marina; Novelli, Rubina; Gagliardini, Elena; Tentori, Chiara; Rottoli, Daniela; Sabadini, Ettore; Saito, Takao; Kawano, Mitsuhiro; Saeki, Takako; Zoja, Carlamaria; Remuzzi, Giuseppe; Benigni, Ariela

2015-01-01

The pathophysiology of glomerular lesions of membranous nephropathy (MN), including seldom-reported IgG4-related disease, is still elusive. Unlike in idiopathic MN where IgG4 prevails, in this patient IgG3 was predominant in glomerular deposits in the absence of circulating anti-phospholipase A2 receptor antibodies, suggesting a distinct pathologic process. Here we documented that IgG4 retrieved from the serum of our propositus reacted against carbonic anhydrase II (CAII) at the podocyte surface. In patient's biopsy, glomerular CAII staining increased and co-localized with subepithelial IgG4 deposits along the capillary walls. Patient's IgG4 caused a drop in cell pH followed by mitochondrial dysfunction, excessive ROS production and cytoskeletal reorganization in cultured podocytes. These events promoted mitochondrial superoxide-dismutase-2 (SOD2) externalization on the plasma membrane, becoming recognizable by complement-binding IgG3 anti-SOD2. Among patients with IgG4-related disease only sera of those with IgG4 anti-CAII antibodies caused low intracellular pH and mitochondrial alterations underlying SOD2 externalization. Circulating IgG4 anti-CAII can cause podocyte injury through processes of intracellular acidification, mitochondrial oxidative stress and neoantigen induction in patients with IgG4 related disease. The onset of MN in a subset of patients could be due to IgG4 antibodies recognizing CAII with consequent exposure of mitochondrial neoantigen in the context of multifactorial pathogenesis of disease. PMID:26137589

Anti-pituitary antibodies against corticotrophs in IgG4-related hypophysitis.

PubMed

Iwata, Naoko; Iwama, Shintaro; Sugimura, Yoshihisa; Yasuda, Yoshinori; Nakashima, Kohtaro; Takeuchi, Seiji; Hagiwara, Daisuke; Ito, Yoshihiro; Suga, Hidetaka; Goto, Motomitsu; Banno, Ryoichi; Caturegli, Patrizio; Koike, Teruhiko; Oshida, Yoshiharu; Arima, Hiroshi

2017-06-01

IgG4-related disease is a systemic inflammatory disease characterized by infiltration of IgG4-positive plasma cells into multiple organs, including the pituitary gland. Autoimmunity is thought to be involved in the pathogenesis of IgG4-related disease. The diagnosis of IgG4-related hypophysitis (IgG4-RH) is difficult because its clinical features, such as pituitary swelling and hypopituitarism, are similar to those of other pituitary diseases, including lymphocytic hypophysitis and sellar/suprasellar tumors. The presence and significance of anti-pituitary antibodies (APA) in IgG4-RH is unclear. In this case-control study, we used single indirect immunofluorescence on human pituitary substrates to assess the prevalence of serum APA in 17 patients with IgG4-RH, 8 control patients with other pituitary diseases (lymphocytic infundibulo-neurohypophysitis, 3; craniopharyngioma, 2; germinoma, 3), and 9 healthy subjects. We further analyzed the endocrine cells targeted by the antibodies using double indirect immunofluorescence. APA were found in 5 of 17 patients with IgG4-RH (29%), and in none of the pituitary controls or healthy subjects. The endocrine cells targeted by the antibodies in the 5 IgG4-RH cases were exclusively corticotrophs. Antibodies were of the IgG1 subclass, rather than IgG4, in all 5 cases, suggesting that IgG4 is not directly involved in the pathogenesis. Finally, antibodies recognized pro-opiomelanocortin in 2 of the cases. Our study suggests that autoimmunity is involved in the pathogenesis of IgG4-RH and that corticotrophs are the main antigenic target, highlighting a possible new diagnostic marker for this condition.

Impact of the -675 4G/5G polymorphism of the plasminogen activator inhibitor-1 gene on childhood IgA nephropathy.

PubMed

Han, Su-Ryun; Kim, Cheon-Jong; Lee, Byung-Cheol

2012-04-01

Plasminogen activator inhibitor-1 (PAI-1) is an important regulator of the fibrinolytic pathway and extracellular matrix (ECM) turnover. The -675 4G/5G polymorphism in the PAI-1 promoter is associated with altered PAI-1 transcription, suggesting that this polymorphism may be a candidate risk factor for diseases characterized by ECM accumulation, such as immunoglobulin A nephropathy (IgAN) and mesangial proliferative glomerulonephritis (MesPGN). We genotyped childhood patients with biopsy-confirmed IgAN (n=111) and MesPGN (n=47), and healthy control subjects (n=230) for the -675 4G/5G PAI-1 polymorphism by polymerase chain reaction-restriction fragment length polymorphism methods. The distribution of the 4G/4G (27.9%), 4G/5G (45.1%) and 5G/5G (27.0%) genotypes in IgAN patients was significantly different from the healthy controls (32.2, 54.3 and 13.5%, respectively) (p=0.0092). There was no significant difference in the genotype distributions of the 4G/5G polymorphism between MesPGN patients and the healthy controls. Regarding the impact of the polymorphism on IgAN, the 4G/4G genotype was markedly increased in patients with proteinuria (≥1,000 mg/day) and/or hypertension when compared to patients without proteinuria and hypertension (OR=5.23, 95% CI 1.34-20.38, P=0.0183). These findings indicate that the PAI-1 gene polymorphism may affect the susceptibility of childhood IgAN.

Key technologies and concepts for beyond-3G networks

NASA Astrophysics Data System (ADS)

Pehkonen, Kari; Uskela, Sami; Kalliojarvi, Kari; Oksanen, Lauri; Rikkinen, Kari

2001-10-01

Standardization of 3rd Generation (3G) mobile communication systems has produced the first specification releases and the commercial deployment of the 3G systems has started. Whereas 1G and 2G focused on efficiently providing voice services, in 3G a lot of attention has been devoted to solutions that support both Circuit Switched (CS) and Packet Switched (PS) communication. That has called for very flexible air interface and network solutions. 3G will continue to evolve and there are already on-going standardization activities that will, for example, boost the peak data rates up to 5-10 Mbps and improve spectral efficiency by 2-4 times. In the future, 3G evolution will be going towards 10/100 Mbps peak data rates in wide/local are coverage, respectively. This will take place partly because of technical improvements of 3G radio interface solutions, but also due to network evolution which will allow the integration other radio access methods like radio LANs into the 3G system. In longer term the 3G network evolution will be going towards ALL-IP networks. As 3G evolution seems to be going towards 10 Mbps/100 Mbps peak data rates and ALL-IP networks any beyond 3G air interface or network solution should be clearly better in order to justify its technical and commercial feasibility. Given the long evolution time of 3G and integration of other radio access schemes with 3G radio we may not even see a new, complete beyond 3G system being developed. Maybe we will just witness the emergence of a new, more advanced radio access solution which will then be connected to the evolving 3G network. As 3G evolution will continue for several years to come the research targets for any beyond 3G solutions must be set very high. When it comes to air interface, we should aim at 100 Mbps peak data rates for wide area access with high mobility, and at 1 Gbps for local area access with low mobility. Regarding possible commercial launches of any beyond 3G systems or solutions they could then

Utility of serum IgG, IgG4 and carbonic anhydrase II antibodies in distinguishing autoimmune pancreatitis from pancreatic cancer and chronic pancreatitis.

PubMed

Talar-Wojnarowska, Renata; Gąsiorowska, Anita; Olakowski, Marek; Dranka-Bojarowska, Daria; Lampe, Paweł; Śmigielski, Jacek; Kujawiak, Magdalena; Grzegorczyk, Janina; Małecka-Panas, Ewa

2014-09-01

Autoimmune pancreatitis (AIP) can mimic pancreatic cancer in its clinical presentation, imaging features and laboratory parameters. The aim of our study was to compare IgG, IgG4 and anti-CAIIAb serum levels in patients with AIP, pancreatic adenocarcinoma (PA) and chronic pancreatitis (CP) and to assess their clinical significance and utility in differential diagnosis of pancreatic diseases. The study included 124 patients: 45 with PA, 24 with AIP and 55 with CP. Peripheral venous blood samples were obtained from all analyzed patients at the time of hospital admission and total IgG, IgG4 and anti-CAIIAB serum levels were measured using ELISA tests. Serum levels of IgG, IgG4 and anti-CAIIAb were significantly higher in patients with AIP compared to PA and CP patients (p<0.001). In AIP patients the median IgG levels were 19.7 g/l, IgG4 levels - 301.9 mg/dl and anti-CAIIAb - 81.82 ng/ml, compared to 10.61 g/l, 123.2mg/dl and 28.6 ng/ml, respectively, in PA patients. IgG4 for the cut-off 210 mg/dl showed the best sensitivity and specificity (83.8% and 89.5%) in AIP diagnosis compared to IgG (69.3% and 87.3%, respectively) and anti-CAIIAb (45.3% and 74.3%). However, 16 (35.5%) patients with PA and 14 (25.4%) patients with CP had IgG4 levels greater than 140 mg/dl. Moreover, in 3 (6.67%) patients with pancreatic cancer those values were greater than 280 mg/dl. No patients with CP had IgG4 more than 280 mg/dl. IgG4 at cut-off 210 mg/dl showed the best sensitivity and specificity in AIP diagnosis compared to IgG and anti-CAIIAb, however elevations of serum IgG4 may be seen in subjects without AIP, including pancreatic cancer. Copyright © 2014 Medical University of Bialystok. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Do serum angiopoietin-1, angiopoietin-2, and their receptor Tie-2 and 4G/5G variant of PAI-1 gene have a role in the pathogenesis of preeclampsia?

PubMed

Kamal, Manal; El-Khayat, Waleed

2011-10-01

To evaluate whether serum angiogenesis markers such as angiopoietins (Ang-1, Ang-2) and their receptor (Tie-2) are altered in women with preeclampsia. We also performed genotyping to determine if the 4G/5G genotypes of -675 PAI-1 gene may play a role in the pathogenesis of preeclampsia. Sixty-eight pregnant women with preeclampsia were compared to 35 normotensive pregnant women and 24 normotensive nonpregnant women in a cross-sectional study. Using enzyme-linked immunosorbent assay, levels of serum Ang-1 and Ang-2, and Tie-2 were measured. A single base pair insertion/deletion 4G/5G polymorphism of the PAI-1 gene was determined by polymerase chain reaction. Serum levels of Ang-1 and Tie-2 were significantly different among the study groups (P = 0.001 and P = 0.025, respectively) being lower in the preeclamptic group. Positive significant correlation was found between Ang-2 and Tie-2, (r = 0.26, P = 0.024). The frequency of the genotypes (4G/5G, 4G/4G, and 5G/5G) differed among the groups (P = 0.001). Also, the mean of systolic and diastolic blood pressures differed significantly according to the PAI-1 genotype being higher in those bearing the 4G allele; P = 0.04 and P = 0.023, respectively. Sera Ang-1 and Ang-2, and Tie-2 as well as variants of 4G/5G of PAI-1 polymorphism have positive implications in the pathogenesis of preeclampsia.

Self-assembled hierarchical carbon/g-C3N4 composite with high photocatalytic activity

NASA Astrophysics Data System (ADS)

Huang, Ru-Long; Huang, Wei-Qing; Li, Dong-Feng; Ma, Li-Li; Pan, Anlian; Hu, Wangyu; Fan, Xiaoxing; Huang, Gui-Fang

2018-04-01

Hierarchical carbon/g-C3N4 composites consisting of nanosheets are synthesized by a direct thermal diffusion and exfoliation approach with glucose acting as the intercalator and carbon source. This facile protocol not only renders nanosheets with a large surface area, but also carbon intercalation into the interlayer of g-C3N4. Therefore, the synthesized carbon/g-C3N4 composites exhibit superior photocatalytic performance for degrading representative methylene blue (MB) under visible light irradiatuon. Carbon/g-C3N4 composites with an optimal glucose mass ratio of 0.25% show the apparent reaction rate constant of 0.253 h-1, which is 9 times higher than that over bluk g-C3N4. The superior photocatalytic performance of carbon/g-C3N4 hierarchical architectures can be attributed to the synergic effects of large reactive sites, effective visible light adsorption and faster charge transfer owing to the superior electron transfer ability of carbon as verified by the PL and photoelectrochemical measurements. The main reactive species responsible for the photocatalytic degradation are photoinduced holes and ·OH radicals under visible light irradiation. This work provides a facile way to fabricate effecient g-C3N4-based photocatalysts for the potential application in dealing with environmental and energy shortage issues using solar energy.

Investigation of Plasminogen Activator Inhibitor-1 (PAI-1) 4G/5G promoter polymorphism in Indian venous thrombosis patients: A case-control study.

PubMed

Prabhudesai, Aniket; Shetty, Shrimati; Ghosh, Kanjaksha; Kulkarni, Bipin

2017-09-01

The role of PAI-1 4G/5G polymorphism in venous thrombosis has been contradictory. PAI-1 4G/4G genotype is associated with elevated levels of PAI-1 resulting in a hypofibrinolytic state and a higher thrombotic risk. In this study, the distribution of genotypes and frequency of alleles of the 4G/5G polymorphism of PAI-1 gene in Indian patients with different types of venous thrombosis was investigated for its role in development of thrombosis. A total of 87 portal vein thrombosis (PVT), 71 Budd-Chiari syndrome (BCS), 156 cerebral vein thrombosis (CVT), and 163 deep vein thrombosis (DVT) patients were studied alongside 251 healthy controls for the PAI-1 4G/5G polymorphism by allele-specific PCR. Frequency of 4G/4G genotype was higher in all groups in comparison with controls. 4G/4G was associated with PVT risk (OR=2.51, 95% CI=1.29-4.96, P=.0075), BCS risk (OR=5.98, 95% CI=2.68-13.42, P<.0001), and DVT risk (OR=1.75, 95% CI=0.98-3.02, P=.0225). This is the first case-control study from India establishing PAI-1 4G/4G as a strong risk factor for abdominal thrombosis (PVT and BCS). Statistically significant association was not found between 4G/4G genotype and CVT risk. PAI-1 4G/4G is a strong risk factor for venous thrombosis in Indian patients and should be included in laboratory testing panel of thrombophilia. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A Hierarchical Z-Scheme α-Fe2 O3 /g-C3 N4 Hybrid for Enhanced Photocatalytic CO2 Reduction.

PubMed

Jiang, Zhifeng; Wan, Weiming; Li, Huaming; Yuan, Shouqi; Zhao, Huijun; Wong, Po Keung

2018-03-01

The challenge in the artificial photosynthesis of fossil resources from CO 2 by utilizing solar energy is to achieve stable photocatalysts with effective CO 2 adsorption capacity and high charge-separation efficiency. A hierarchical direct Z-scheme system consisting of urchin-like hematite and carbon nitride provides an enhanced photocatalytic activity of reduction of CO 2 to CO, yielding a CO evolution rate of 27.2 µmol g -1 h -1 without cocatalyst and sacrifice reagent, which is >2.2 times higher than that produced by g-C 3 N 4 alone (10.3 µmol g -1 h -1 ). The enhanced photocatalytic activity of the Z-scheme hybrid material can be ascribed to its unique characteristics to accelerate the reduction process, including: (i) 3D hierarchical structure of urchin-like hematite and preferable basic sites which promotes the CO 2 adsorption, and (ii) the unique Z-scheme feature efficiently promotes the separation of the electron-hole pairs and enhances the reducibility of electrons in the conduction band of the g-C 3 N 4 . The origin of such an obvious advantage of the hierarchical Z-scheme is not only explained based on the experimental data but also investigated by modeling CO 2 adsorption and CO adsorption on the three different atomic-scale surfaces via density functional theory calculation. The study creates new opportunities for hierarchical hematite and other metal-oxide-based Z-scheme system for solar fuel generation. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

2D/2D graphitic carbon nitride (g-C3N4) heterojunction nanocomposites for photocatalysis: Why does face-to-face interface matter?

NASA Astrophysics Data System (ADS)

Ong, Wee-Jun

2017-04-01

In recent years, two-dimensional (2D) graphitic carbon nitride (g-C3N4) has elicited interdisciplinary research fascination among the scientific communities due to its attractive properties such as appropriate band structures, visible-light absorption, and high chemical and thermal stability. At present, research aiming at engineering 2D g-C3N4 photocatalysts at an atomic and molecular level in conquering the global energy demand and environmental pollution has been thriving. In this review, the cutting-edge research progress on the 2D/2D g-C3N4-based hybrid nanoarchitectures will be systematically highlighted with a specific emphasis on a multitude of photocatalytic applications, not only in waste degradation for pollution alleviation, but also in renewable energy production (e.g. water splitting and carbon dioxide (CO2) reduction). By reviewing the substantial developments on this hot research platform, it is envisioned that the review will shed light and pave a new prospect for constructing high photocatalytic performance of 2D/2D g-C3N4-based system, which could also be extended to other related energy fields, namely solar cells, supercapacitors and electrocatalysis.

Distances to supernova remnants G20.4 + 0.1, G24.7 - 0.6, and G28.6 - 0.1 and new molecular cloud associations

NASA Astrophysics Data System (ADS)

Ranasinghe, S.; Leahy, D. A.

2018-06-01

Accurate distances to supernova remnants (SNRs) are crucial in determining their size, age, luminosity, and evolutionary state. To determine distances, we chose three SNRs from the VLA (Very Large Array) Galactic Plane Survey for extraction of H I absorption spectra. Analysing H I absorption spectra, 13CO emission spectra, and H I and 13CO channel maps, kinematic velocities (or their limits) to the three SNRs were calculated. The three SNRs are probably associated with molecular clouds and the new distance to G20.4 + 0.1, G24.7 - 0.6, and G28.6 - 0.1 are 7.8 ± 0.5 kpc, 3.8 ± 0.2 kpc, and 9.6 ± 0.3 kpc, respectively.

Graphene and g-C3N4 based photocatalysts for NOx removal: A review

NASA Astrophysics Data System (ADS)

Nikokavoura, Aspasia; Trapalis, Christos

2018-02-01

NOx liberated into atmosphere from automobile exhausts and fossil fuel combustion, comprise the major air pollutants. They are responsible for serious environmental problems such as acid rain, ozone accumulation, haze and photochemical smog. Besides they contribute to the deterioration of human health by causing decrease of the lung function and respiratory problems. The application of photocatalytic methods in order to mitigate the presence of NOx in the atmosphere is preferable as they are environmentally friendly, mild and low cost. Therefore, in this review, the photocatalytic activity of g-C3N4 and graphene based composites towards NOx removal was discussed. NOx oxidation to non volatile nitrates on the surface of graphene and g-C3N4 based photocatalysts has attracted much interest during the last years due to their structures with unique features such as large specific surface area, thermal and chemical stability and enhanced visible light utilization. The formation of 2D-2D intimate heterojunctions between graphene or g-C3N4 and other components ensures the enhanced charge transfer, lifetime of electron/hole pairs and thus photocatalytic activity. The increased visible light harvesting also contributes to their usefulness as effective photocatalytic materials. In the present work, the advantages of these novel photocatalysts and the differences/similarities between them were exhaustively highlighted. The role of graphene as catalyst promoter, electron reservoir, support and photosensitizer in its photocatalytic composites was emphasized. The effect of g-C3N4 doping and copolymerization with metals/semiconductors on its photocatalytic activity towards NOx oxidation was thoroughly discussed. Besides, the preparation methods, photocatalytic efficiencies, type of irradiation, utilization of appropriate cocatalysts, and reaction mechanisms during the photocatalytic NOx removal by graphene and g-C3N4 composies, were summarized. It was demonstrated that in the vast

Association between plasminogen activator inhibitor-1 4G/5G gene polymorphism and immunoglobulin A nephropathy susceptibility.

PubMed

Zhou, Tian-Biao; Jiang, Zong-Pei

2015-02-01

The association between plasminogen activator inhibitor-1 (PAI-1) 4 G/5 G gene polymorphism and immunoglobulin A nephropathy (IgAN) risk is still controversial. A meta-analysis was performed to evaluate the association between PAI-1 4 G/5 G gene polymorphism and IgAN susceptibility. A predefined literature search and selection of eligible relevant studies were performed to collect data from electronic database. Four articles were identified for the analysis of association between PAI-1 4 G/5 G gene polymorphism and IgAN risk. 4 G allele was not associated with IgAN susceptibility in overall populations and in Asians. Furthermore, 4 G/4 G and 5 G/5 G genotype were not associated with IgAN for overall populations, Asians. In conclusion, PAI-1 4 G/5 G gene polymorphism was not associated with IgAN risk in overall populations and in Asians. However, more studies should be performed in the future.

The binding of manganese(II) and zinc(II) to the synthetic oligonucleotide d(C-G-C-G-A-A-T-T-C-G-C-G)2. A 1H NMR study.

PubMed

Frøystein, N A; Sletten, E

1991-03-01

The interaction of the synthetic oligonucleotide d(C-G-C-G-A-A-T-T-C-G-C-G)2 with two different transition-metal ions has been investigated in aqueous solution by means of 1H NMR spectroscopy. The effects on the DNA due to the presence of manganese(II) or zinc(II) have been monitored by observing the paramagnetic broadening and diamagnetic shifts of the non-exchangeable proton resonance lines, respectively. The 1H NMR spectra acquired during the course of the manganese(II) titration show very distinct broadening effects on certain DNA resonance lines. Primarily, the H8 resonance of G4 is affected, but also the H5 and H6 resonances of C3 are clearly affected by the metal. The results imply that the binding of manganese(II) to DNA is sequence specific. The 1H spectra obtained during the zinc(II) titration reveal diamagnetic shift effects which largely conform with the paramagnetic broadening effects due to the presence of manganese(II), although this picture is somewhat more complex. The H8 resonance of G4 displays a clearly visible high-field shift, while for the other guanosine H8 protons this effect is absent. The H1' and H2' protons of C3 show an effect of similar strength, although in the opposite direction, while H5 and H6 of C3 are only slightly affected. Local differences in the structure of the DNA and the basicities of potential binding sites on different base steps in the sequence might account for the observed sequence selectivity.

A double chain reversal loop and two diagonal loops define the architecture of a unimolecular DNA quadruplex containing a pair of stacked G(syn)-G(syn)-G(anti)-G(anti) tetrads flanked by a G-(T-T) Triad and a T-T-T triple.

PubMed

Kuryavyi, V; Majumdar, A; Shallop, A; Chernichenko, N; Skripkin, E; Jones, R; Patel, D J

2001-06-29

The architecture of G-G-G-G tetrad-aligned DNA quadruplexes in monovalent cation solution is dependent on the directionality of the four strands, which in turn are defined by loop connectivities and the guanine syn/anti distribution along individual strands and within individual G-G-G-G tetrads. The smallest unimolecular G-quadruplex belongs to the d(G2NnG2NnG2NnG2) family, which has the potential to form two stacked G-tetrads linked by Nn loop connectivities. Previous studies have focused on the thrombin-binding DNA aptamer d(G2T2G2TGTG2T2G2), where Nn was T2 for the first and third connecting loops and TGT for the middle connecting loop. This DNA aptamer in K(+) cation solution forms a unimolecular G-quadruplex stabilized by two stacked G(syn)-G(anti)-G(syn)-G(anti) tetrads, adjacent strands which are antiparallel to each other and edge-wise connecting T2, TGT and T2 loops. We now report on the NMR-based solution structure of the d(G2T4G2CAG2GT4G2T) sequence, which differs from the thrombin-binding DNA aptamer sequence in having longer first (T4) and third (GT4) loops and a shorter (CA) middle loop. This d(G2T4G2CAG2GT4G2T) sequence in Na(+) cation solution forms a unimolecular G-quadruplex stabilized by two stacked G(syn)-G(syn)-G(anti)-G(anti) tetrads, adjacent strands which have one parallel and one antiparallel neighbors and distinct non-edge-wise loop connectivities. Specifically, the longer first (T4) and third (GT4) loops are of the diagonal type while the shorter middle loop is of the double chain reversal type. In addition, the pair of stacked G-G-G-G tetrads are flanked on one side by a G-(T-T) triad and on the other side by a T-T-T triple. The distinct differences in strand directionalities, loop connectivities and syn/anti distribution within G-G-G-G tetrads between the thrombin-binding DNA aptamer d(G2T2G2TGTG2T2G2) quadruplex reported previously, and the d(G2T4G2CAG2GT4G2T) quadruplex reported here, reinforces the polymorphic nature of higher

Influence of decreased fibrinolytic activity and plasminogen activator inhibitor-1 4G/5G polymorphism on the risk of venous thrombosis.

PubMed

Vuckovic, Biljana A; Djeric, Mirjana J; Tomic, Branko V; Djordjevic, Valentina J; Bajkin, Branislav V; Mitic, Gorana P

2018-01-01

: Objective of our study is to determine whether decreased fibrinolytic activity or plasminogen activator inhibitor (PAI)-1 4G/5G polymorphism influence the risk of venous thrombosis.Our case-control study included 100 patients with venous thrombosis, and 100 random controls. When patients were compared with random controls, unconditional logistic regression was used to calculate odds ratios (ORs) with 95% confidence intervals (CIs).Decreased fibrinolytic activity yielded a 2.7-fold increase in risk for venous thrombosis than physiological fibrinolytic activity (OR 2.70; 95% CI 1.22-5.98), when comparing patients with random controls. Adjustment for several putative confounders did not change the estimate (OR 3.02; 95% CI 1.26-7.22). Analysis of venous thrombotic risk influenced by PAI-1 genotype, showed no influence of PAI-1 4G/5G gene variant in comparison with 5G/5G genotype (OR 0.57 95% CI; 0.27-1.20).Decreased fibrinolytic activity increased, whereas PAI-1 4G/5G polymorphism did not influence venous thrombosis risk in this study.

Self-assembled hierarchical direct Z-scheme g-C3N4/ZnO microspheres with enhanced photocatalytic CO2 reduction performance

NASA Astrophysics Data System (ADS)

Nie, Ning; Zhang, Liuyang; Fu, Junwei; Cheng, Bei; Yu, Jiaguo

2018-05-01

Photocatalytic reduction of CO2 into hydrocarbon fuels has been regarded as a promising approach to ease the greenhouse effect and the energy shortage. Herein, an electrostatic self-assembly method was exploited to prepare g-C3N4/ZnO composite microsphere. This method simply utilized the opposite surface charge of each component, achieving a hierarchical structure with intimate contact between them. A much improved photocatalytic CO2 reduction activity was attained. The CH3OH production rate was 1.32 μmol h-1 g-1, which was 2.1 and 4.1 times more than that of the pristine ZnO and g-C3N4, respectively. This facile design bestowed the g-C3N4/ZnO composite an extended light adsorption caused by multi-light scattering effect. It also guaranteed the uniform distribution of g-C3N4 nanosheets on the surface of ZnO microspheres, maximizing their advantage and synergistic effect. Most importantly, the preeminent performance was proposed and validated based on the direct Z-scheme. The recombination rate was considerably suppressed. This work features the meliority of constructing hierarchical direct Z-scheme structures in photocatalytic CO2 reduction reactions.

The -675 4G/5G polymorphism in the PAI-1 gene may not contribute to the risk of PCOS.

PubMed

Zhang, T-T; Yuan, L; Yang, Y-M; Ren, Y

2014-08-01

The association between the -675 4G/5G polymorphism in PAI-1 gene and PCOS has been studied with inconclusive results. We sought to investigate this inconsistency by performing a comprehensive meta-analysis on the polymorphism. Searches were performed in the PubMed, Embase, CNKI and Wanfang databases, covering all papers. Statistical analysis was performed using Revman5.2 and STATA11.0 software. A total of 11 case-control studies were extracted on the polymorphism involving 1861 PCOS cases and 1187 controls. The results showed that, no significant increased/decreased risk were found for the polymorphism for PCOS: OR = 1.03, 95% CI = 0.77-1.66, p = 0.52 for 4G4G + 4G5G vs. 5G5G; OR = 0.99, 95% CI = 0.66-1.49, p = 0.96 for 4G4G vs. 5G5G + 4G5G; OR = 1.08, 95% CI = 0.66-1.79, p = 0.76 for 4G4G vs. 5G5G; OR = 1.11, 95% CI = 0.78-1.58, p = 0.56 for 4G5G vs. 5G5G; OR = 1.00, 95% CI = 0.71-1.41, p = 0.99 for 4G vs. 5G. In the further subgroup analysis by ethnicity, we did not find a significant association between the polymorphism for PCOS risk in either Asians or Europeans. Our findings demonstrated that -675 4G/5G polymorphism in the PAI-1 gene might not be a risk factor for the development of PCOS.

Impact of the -675 4G/5G polymorphism of the plasminogen activator inhibitor-1 gene on childhood IgA nephropathy

PubMed Central

HAN, SU-RYUN; KIM, CHEON-JONG; LEE, BYUNG-CHEOL

2012-01-01

Plasminogen activator inhibitor-1 (PAI-1) is an important regulator of the fibrinolytic pathway and extracellular matrix (ECM) turnover. The -675 4G/5G polymorphism in the PAI-1 promoter is associated with altered PAI-1 transcription, suggesting that this polymorphism may be a candidate risk factor for diseases characterized by ECM accumulation, such as immunoglobulin A nephropathy (IgAN) and mesangial proliferative glomerulonephritis (MesPGN). We genotyped childhood patients with biopsy-confirmed IgAN (n=111) and MesPGN (n=47), and healthy control subjects (n=230) for the -675 4G/5G PAI-1 polymorphism by polymerase chain reaction-restriction fragment length polymorphism methods. The distribution of the 4G/4G (27.9%), 4G/5G (45.1%) and 5G/5G (27.0%) genotypes in IgAN patients was significantly different from the healthy controls (32.2, 54.3 and 13.5%, respectively) (p=0.0092). There was no significant difference in the genotype distributions of the 4G/5G polymorphism between MesPGN patients and the healthy controls. Regarding the impact of the polymorphism on IgAN, the 4G/4G genotype was markedly increased in patients with proteinuria (≥1,000 mg/day) and/or hypertension when compared to patients without proteinuria and hypertension (OR=5.23, 95% CI 1.34–20.38, P=0.0183). These findings indicate that the PAI-1 gene polymorphism may affect the susceptibility of childhood IgAN. PMID:22969955

In situ one-step hydrothermal synthesis of oxygen-containing groups-modified g-C3N4 for the improved photocatalytic H2-evolution performance

NASA Astrophysics Data System (ADS)

Wu, Xinhe; Chen, Fengyun; Wang, Xuefei; Yu, Huogen

2018-01-01

Surface modification of g-C3N4 is one of the most effective strategies to boost its photocatalytic H2-evolution performance via promoting the interfacial catalytic reactions. In this study, an in situ one-step hydrothermal method was developed to prepare the oxygen-containing groups-modified g-C3N4 (OG/g-C3N4) by a facile and green hydrothermal treatment of bulk g-C3N4 in pure water without any additives. It was found that the hydrothermal treatment (180 °C) not only could greatly increase the specific surface area (from 2.3 to 69.8 m2 g-1), but also caused the formation of oxygen-containing groups (sbnd OH and Cdbnd O) on the OG/g-C3N4 surface, via the interlayer delamination and intralayer depolymerization of bulk g-C3N4. Photocatalytic experimental results indicated that after hydrothermal treatment, the resultant OG/g-C3N4 samples showed an obviously improved H2-evolution performance. Especially, when the hydrothermal time was 6 h, the resultant OG/g-C3N4(6 h) exhibited the highest photocatalytic activity, which was clearly higher than that of the bulk g-C3N4 by a factor of ca. 7. In addition to the higher specific surface area, the enhanced H2-evolution rate of OG/g-C3N4 photocatalysts can be mainly attributed to the formation of oxygen-containing groups, which possibly works as the effective H2-evolution active sites. Considering the facie and green synthesis method, the present work may provide a new insight for the development of highly efficient photocatalytic materials.

PAI-1 expression and its regulation by promoter 4G/5G polymorphism in clear cell renal cell carcinoma.

PubMed

Choi, Jung-Woo; Lee, Ju-Han; Park, Hong Seok; Kim, Young-Sik

2011-10-01

To characterise patients with high plasminogen activator inhibitor-1 (PAI-1) expression as oral PAI-1 antagonists are currently in preclinical trials, and to determine whether the PAI-1 promoter 4G/5G polymorphism regulates PAI-1 expression in clear cell renal cell carcinoma (CCRCC). PAI-1 expression was examined by immunohistochemistry in 69 CCRCC specimens. In addition, the promoter 4G/5G polymorphism was investigated by both allele-specific PCR and direct DNA sequencing. PAI-1 was overexpressed in 25/69 (36.2%) patients with CCRCC. PAI-1 staining was intense in tumour cells with a high Fuhrman nuclear grade and in spindle-shaped tumour cells. PAI-1 expression was significantly associated with older age at diagnosis (p=0.027), high nuclear grade (p<0.001), advanced clinical stage (p=0.030) and distant metastasis (p=0.009). In survival analyses, PAI-1 expression was correlated with disease-free survival in Kaplan-Meier curves (p=0.015) but was not significant in the Cox hazards model (p=0.527). The frequencies of the promoter polymorphism were 24.6% (17/69) 4G/4G, 43.5% (30/69) 4G/5G and 31.9% (22/69) 5G/5G. The homozygous 4G/4G or 5G/5G group showed a tendency for a high nuclear grade (p=0.05) but the 4G/5G polymorphism was not related to other prognostic parameters. PAI-1 expression was poorly correlated with its promoter 4G/5G polymorphism (Spearman ρ=0.088). CCRCC with high PAI-1 expression is characterised by older age, high nuclear grade, advanced stage, distant metastasis and/or shortened disease-free survival. PAI-1 expression is not affected by the promoter 4G/5G polymorphism.

Cardiovascular effects of anti-G suit inflation at 1 and 2 G.

PubMed

Montmerle, Stéphanie; Linnarsson, Dag

2005-06-01

We sought to determine to which pressure a full-coverage anti-G suit needs to be inflated in order to obtain the same stroke volume during a brief exposure to twice the normal gravity (2 G) as that at 1 G without anti-G suit inflation. Nine sitting subjects were studied at normal (1 G) and during 20 s of exposure to 2 G. They wore anti-G suits, which were inflated at both G-levels to the following target pressures: 0, 70, 140 and 210 mmHg. Stroke volume was computed from cardiac output, which was measured by rebreathing. Heart rate and mean arterial pressure at heart level were recorded. Inflation to 70 mmHg compensated for the decrease in stroke volume and cardiac output caused by hypergravity. Mean arterial pressure at heart level was comparable at 1 G and at 2 G and increased gradually and similarly with inflation (P<0.001) at both gravity levels. Thus, anti-G suits act by increasing both preload and afterload but the two effects counteract each other in terms of cardiac output, so that cardiac output at 2 G is maintained at its 1 G level. This effect is reached already at 70 mmHg of inflation. Greater inflation pressure further increases mean arterial pressure at heart level and compensates for the increased difference in hydrostatic pressure between heart and head in moderate hypergravity.

IgG4 subclass antibodies impair antitumor immunity in melanoma

PubMed Central

Karagiannis, Panagiotis; Gilbert, Amy E.; Josephs, Debra H.; Ali, Niwa; Dodev, Tihomir; Saul, Louise; Correa, Isabel; Roberts, Luke; Beddowes, Emma; Koers, Alexander; Hobbs, Carl; Ferreira, Silvia; Geh, Jenny L.C.; Healy, Ciaran; Harries, Mark; Acland, Katharine M.; Blower, Philip J.; Mitchell, Tracey; Fear, David J.; Spicer, James F.; Lacy, Katie E.; Nestle, Frank O.; Karagiannis, Sophia N.

2013-01-01

Host-induced antibodies and their contributions to cancer inflammation are largely unexplored. IgG4 subclass antibodies are present in IL-10–driven Th2 immune responses in some inflammatory conditions. Since Th2-biased inflammation is a hallmark of tumor microenvironments, we investigated the presence and functional implications of IgG4 in malignant melanoma. Consistent with Th2 inflammation, CD22+ B cells and IgG4+-infiltrating cells accumulated in tumors, and IL-10, IL-4, and tumor-reactive IgG4 were expressed in situ. When compared with B cells from patient lymph nodes and blood, tumor-associated B cells were polarized to produce IgG4. Secreted B cells increased VEGF and IgG4, and tumor cells enhanced IL-10 secretion in cocultures. Unlike IgG1, an engineered tumor antigen-specific IgG4 was ineffective in triggering effector cell–mediated tumor killing in vitro. Antigen-specific and nonspecific IgG4 inhibited IgG1-mediated tumoricidal functions. IgG4 blockade was mediated through reduction of FcγRI activation. Additionally, IgG4 significantly impaired the potency of tumoricidal IgG1 in a human melanoma xenograft mouse model. Furthermore, serum IgG4 was inversely correlated with patient survival. These findings suggest that IgG4 promoted by tumor-induced Th2-biased inflammation may restrict effector cell functions against tumors, providing a previously unexplored aspect of tumor-induced immune escape and a basis for biomarker development and patient-specific therapeutic approaches. PMID:23454746