Implications for food safety of the uptake by tomato of 25 trace-elements from a phosphogypsum amended soil from SW Spain.

PubMed

Enamorado, Santiago; Abril, José M; Delgado, Antonio; Más, José L; Polvillo, Oliva; Quintero, José M

2014-02-15

Phosphogypsum (PG) has been usually applied as Ca-amendment to reclaim sodic soils such as those in the marshland area of Lebrija (SW Spain). This work aimed at the effects of PG amendments on the uptake of trace-elements by tomato and its implications for food safety. A completely randomized experiment was performed using a representative soil from Lebrija in a greenhouse involving six replicates and four PG treatments equivalent to 0, 20, 60, and 200 Mg ha(-1). Soil-to-plant transfer factors (TFs) were determined for Be, B, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Mo, Ag, Cd, Sb, Cs, Ba, Tl, Pb, Th and U. The highest TF in shoots was observed for Cd (4.0; 1.5 in fruits), its concentration being increased with increasing PG doses due to its content in this metal (2.1 mg Cd kg(-1)PG). Phosphogypsum applying decreased the concentrations of Mn, Co and Cu in shoots; and of B, Cu, Sb, Cs, Ba, Tl and Th in fruits, however enhanced the accumulation of Se in fruits. Although Cd concentrations in tomato were below the maximum allowed levels in control pots (0 Mg PG ha(-1)), PG amendments above 60 Mg ha(-1) exceeded such limits. Copyright © 2013 Elsevier B.V. All rights reserved.

Alagille Syndrome Candidates for Liver Transplantation: Differentiation from End-Stage Biliary Atresia Using Preoperative CT.

PubMed

Hwang, Sook Min; Jeon, Tae Yeon; Yoo, So-Young; Kim, Ji Hye; Kang, Ben; Choe, Yon Ho; Cho, Haeyon; Kim, Jung Sun

2016-01-01

To compare preoperative CT findings before liver transplantation between patients with Alagille syndrome (AGS) and those with end-stage biliary atresia (BA). The institutional review board approved this retrospective study. Eleven children with AGS (median age, 19.0 ± 13.0 months; male to female ratio, 3:8) and 109 children with end-stage BA (median age, 17.9 ± 25.8 months; male to female ratio, 37:72) who underwent abdomen CT as candidates for liver transplant were included. CT images were reviewed focusing on hepatic parenchymal changes, vascular changes, presence of focal lesions, and signs of portal hypertension. Hepatic parenchymal changes were present in 27% (3/11) of AGS patients and 100% (109/109) of end-stage BA patients (P < .001). The hepatic artery diameter was significantly smaller (1.9 mm versus 3.6 mm, P = 008), whereas portal vein diameter was larger (6.8 mm versus 5.0 mm, P < .001) in patients with AGS compared with patients with end-stage BA. No focal lesion was seen in patients with AGS, whereas 44% (48/109) of patients with end-stage BA had intrahepatic biliary cysts (39%, 43/109) and hepatic tumors (8%, 9/109) (P = .008). Splenomegaly was commonly seen in both groups (P = .082), and ascites (9% [1/11] versus 50% [54/109], P = .010) and gastroesophageal varix (0% [0/11] versus 80% [87/109], P < .001) were less common in patients with AGS than in patients with end-stage BA. Fibrotic or cirrhotic changes of the liver, presence of focal lesions, and relevant portal hypertension were less common in patients with AGS than in patients with end-stage BA.

Selenium and 17 other largely essential and toxic metals in muscle and organ meats of Red Deer (Cervus elaphus)--consequences to human health.

PubMed

Jarzyńska, Grażyna; Falandysz, Jerzy

2011-07-01

Concentrations, composition and interrelationships of selenium and metallic elements (Ag, Ba, Cd, Co, Cr, Cs, Cu, Ga, Mn, Mo, Pb, Rb, Sb, Sr, Tl, V and Zn) have been examined in muscle and organ meats of Red Deer hunted in Poland. The analytical data obtained were also discussed in terms of Se supplementation and deficit to Deer as well as the benefits and risk to humans associated with the essential and toxic metals intake resulting from consumption of Deer meat and products. These elements were determined in 20 adult animals of both sexes that were obtained in the 2000/2001 hunting season from Warmia and Mazury in the north-eastern part of Poland. The whole kidneys contained Ba, Cd, Cr, Ga, Pb, Se, Sr and Tl at statistically greater concentrations than liver or muscle tissue from the same animal. Liver showed statistically greater concentrations of Ag, Co, Cu, Mn and Mo than kidneys or muscle tissue, and muscle tissue was richer in Zn, when compared to the kidneys or liver. Cs and Rb were similarly distributed between all three tissue types, while V was less abundant in liver than kidneys or muscle tissue. There were significant associations between some metallic elements retained in Red Deer demonstrated by Principal Component Analysis (PCA) of the data set. In organ and muscle meats (kidneys, liver and muscle tissue considered together) the first principal component (PC1) was strongly influenced by positively correlated variables describing Se, Ba and Cd and negatively correlated variables describing Ag, Co, Cs, Mn, Pb, Tl and V; PC2, respectively, by Cu, Mn and Mo (+) and Zn (-); PC3 by Ga (+) and PC4 by Sb (+). Selenium occurred in muscle tissue, liver and kidneys at median concentrations of 0.13, 0.19 and 4.0mg/g dry weight, respectively. These values can be defined as marginally deficient (< 0.6mg Se/kg liver dw) or satisfactory (≤ 3.0mg Se/kg kidneys dw) for the amount required to maintain the Deer's body condition and health, depending on the criterion for supplementation used. In terms of human nutritional needs, a relatively high selenium content of kidneys can be beneficial. The muscle meat, liver and kidneys of Red Deer can be considered as a very good source of essential Co, Cr, Cu, Mo, Mn, Se and Zn in the human diet. Lead is generally considered as toxic, and the concentrations found in Red Deer (via the food chain intake) were well below the European Union tolerance limit. Pb from the lead bullets can always create food hygienic problem, if not well recognized during sanitary inspection, and this was noted for one muscle meat sample in this study (5% surveyed). There is no tolerance limit of Cd in game animal meats. The median values of Cd noted in fresh muscle tissue, liver and whole kidneys were 0.07, 0.18, and 3.3mg/kg wet weight, respectively. Cd exists as a chemical element present at trace levels in plants and mushrooms in Deer's food chain in background (uncontaminated) areas. When these are consumed by the Deer, the amount of Cd sequestered with metallothioneins and retained in the organ and muscle meat in this study is low enough to be considered safe for human consumption. Copyright © 2011 Elsevier Ltd. All rights reserved.

Baicalin benefits the anti-HBV therapy via inhibiting HBV viral RNAs

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

Huang, Hai, E-mail: HHai3552@sina.cn

Background: Although current antiviral treatments (nucleoside analogs, NAs) for chronic hepatitis B virus (HBV) infection are effective in suppressing HBV-DNA replication, their clinical outcomes can be compromised by the increasing drug resistance and the inefficiency in promoting HBsAg/HBeAg seroconversion. Objectives: In this study, we will explore possible effects and mechanism of a natural product baicalin (BA) with the anti-HBV efficacy of entecavir (ETV), a first-line anti-HBV drug, in HBV-DNA, HBsAg/HBeAg seroconversion and drug-resistance. Methods: The co-effects of BA and ETV were conducted in wild-type/NA-resistance mutant HBV cell lines and DHBV-infected duckling models. HBV-DNA/RNAs, HBsAg/HBeAg, host factors (hepatocyte nuclear factors) weremore » explored for possible anti-HBV mechanism. Results and discussion: BA could significantly enhance and reduced HBsAg and HBeAg in hepG2.2.15, a wild-type HBV cell line. Co-treatment of BA and ETV had a more dramatic effect in NA-resistant HBV{sup rtM204V/rtLl80M} transfected hepG2 cells. Our study further revealed that BA mainly inhibited the production of HBV RNAs (3.5, 2.4, 2.1 kb), the templates for viral proteins and HBV-DNA synthesis. BA blocked HBV RNAs transcription possibly by down-regulating transcription and expression of HBV replication dependent hepatocyte nuclear factors (HNF1α and HNF4α). Thus, BA may benefit the anti-HBV therapy via inhibiting HBV viral RNAs. - Highlights: • Baicalin benefits the anti-HBV therapy. • Baicalin enhances ETV antiviral efficacy and overcomes NA-resistant HBV mutation. • The anti-HBV effect of baicalin is achieved by inhibiting HBV RNAs. • Baicalin down-regulates HBV replication-dependent host factors HNF 1α and HNF 4α.« less

Trace elements in muscle of three fish species from Todos os Santos Bay, Bahia State, Brazil.

PubMed

de Santana, Carolina Oliveira; de Jesus, Taíse Bomfim; de Aguiar, William Moura; de Jesus Sant'anna Franca-Rocha, Washington; Soares, Carlos Alberto Caroso

2017-03-01

In this study, an analysis was performed on the concentrations of the trace elements Al, As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, V, and Zn in muscle of two carnivorous and one planktivorous fish species collected at Todos os Santos Bay (BTS). The accumulation order of the trace elements in Lutjanus analis was Al >Zn >Fe >Cr >Ba >Ni. In Cetengraulis edentulus, the order was Al >Fe >Zn >Cr >Ni >Mn >As. In the species Diapterus rhombeus, the order was Al >Fe >Zn >Cr >Ni >Mn >Cd. To determine the risk related to the consumption of fish, toxicity guidelines were used as standard references. It was observed that the species C. edentulus contained concentrations of As exceeding WHO limits, but these concentrations were acceptable according to the Agência Nacional de Vigilância Sanitária (ANVISA) guidelines. Cd levels were found only in D. rhombeus and in low concentrations according to the determinations of WHO and ANVISA. Pb levels were not detected in any of the three fish species. The analyzed elements did not differ statistically according to the species and feeding habits. The results point to possible risks of human contamination by As related to the consumption of the fish species C. edentulus from the BTS.

Carbon Dioxide Gas Sensors and Method of Manufacturing and Using Same

NASA Technical Reports Server (NTRS)

Hunter, Gary W. (Inventor); Xu, Jennifer C. (Inventor)

2014-01-01

A gas sensor comprises a substrate layer; a pair of interdigitated metal electrodes, said electrodes include upper surfaces, the electrodes selected from the group consisting of Pt, Pd, Au, Ir, Ag, Ru, Rh, In, Os, and their alloys. A first layer of solid electrolyte staying in between electrode fingers and partially on said upper surfaces of said electrodes, said first layer selected from NASICON, LISICON, KSICON and.beta.''-Alumina. A second layer of metal carbonate(s) as an auxiliary electrolyte engaging said upper surfaces of the electrodes and the first solid electrolyte. The metal carbonates selected from the group consisting of the following ions Na.sup.+, K.sup.+, Li.sup.+, Ag.sup.+, H.sup.+, Pb.sup.2+, Sr.sup.2+, Ba.sup.2+, and any combination thereof. An extra layer of metal oxide selected from the group consisting of SnO.sub.2, In.sub.2O.sub.3, TiO.sub.2, WO.sub.3, ZnO, Fe.sub.2O.sub.3, ITO, CdO, U.sub.3O.sub.8, Ta.sub.2O.sub.5, BaO, MoO.sub.2, MoO.sub.3, V.sub.2O.sub.5, Nb.sub.2O.sub.5, CuO, Cr.sub.2O.sub.3, La.sub.2O.sub.3, RuO.sub.3, RuO.sub.2, ReO.sub.2, ReO.sub.3, Ag.sub.2O, CoO, Cu.sub.2O, SnO, NiO, Pr.sub.2O.sub.3, BaO, PdO.sub.2, HfO.sub.3, HfO.sub.3 or other metal oxide and their mixtures residing above and in engagement with the second electrolyte to improve sensor performance and/or to reduce sensor heating power consumption.

Modification of energy band alignment and electric properties of Pt/Ba{sub 0.6}Sr{sub 0.4}TiO{sub 3}/Pt thin-film ferroelectric varactors by Ag impurities at interfaces

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

Hirsch, S.; Komissinskiy, P., E-mail: komissinskiy@oxide.tu-darmstadt.de; Flege, S.

2014-06-28

We report on the effects of Ag impurities at interfaces of parallel-plate Pt/Ba{sub 0.6}Sr{sub 0.4}TiO{sub 3}/Pt thin film ferroelectric varactors. Ag impurities occur at the interfaces due to diffusion of Ag from colloidal silver paint used to attach the varactor samples with their back side to the plate heated at 600–750 °C during deposition of Ba{sub 0.6}Sr{sub 0.4}TiO{sub 3}. X-ray photoelectron spectroscopy and secondary ion mass spectrometry suggest that amount and distribution of Ag adsorbed at the interfaces depend strongly on the adsorbent surface layer. In particular, Ag preferentially accumulates on top of the Pt bottom electrode. The presence of Agmore » significantly reduces the barrier height between Pt and Ba{sub 0.6}Sr{sub 0.4}TiO{sub 3} leading to an increased leakage current density and, thus, to a severe degradation of the varactor performance.« less

Metallic elements and metalloids in Boletus luridus, B. magnificus and B. tomentipes mushrooms from polymetallic soils from SW China.

PubMed

Falandysz, Jerzy; Zhang, Ji; Wiejak, Anna; Barałkiewicz, Danuta; Hanć, Anetta

2017-08-01

Yunnan Province in China is known for its high biodiversity of mushrooms and a diverse geochemistry of soil bedrock and polymetallic soils, but our knowledge of mineral compositions of mushrooms from Yunnan is scarce. The metallic trace elements, Ag, Ba, Co, Cd, Cs, Cu, Cr, Hg, Li, Mn, Ni, Pb, Rb, Sr, V, Tl, U and Zn, and the metalloids, As and Sb, have been investigated using validated methods with a dynamic reactive cell by mass spectroscopy - inductive coupled plasma and cold vapour - atomic absorption spectroscopy on three popular species of Boletus mushrooms from Southwestern China. The trace mineral profiles in caps and stipes of B. luridus (24 individuals), B. magnificus (29 individuals) and B. tomentipes (38 individuals) have been evaluated. The interspecific differences in the content of several trace elements could be attributed to known differences in the geochemistry of soils in Yunnan, but for copper a difference was observed within species. The mean values of concentrations in composite samples of caps for B. luridus, B. magnificus and B. tomentipes from three to four locations were at the ranges (mgkg -1 dry biomass): Ag (1.3-3.7), As (0.79-53), Ba (4.0-12), Co (0.68-1.2), Cd (0.79-2.2), Cs (0.67-55), Cu (37-77), Cr (5.0-7.6), Hg (2.1-5.4), Li (0.15-0.61), Mn (13-28), Ni (0.86-4.6), Pb (0.59-1.8), Rb (90-120), Sb (0.014-0.088), Sr (0.63-1.6), V (1.4-2.2), Tl (0.017-0.054), U (0.029-0.065) and Zn (130-180). Caps of Boletus mushrooms were richer in Ag, Cu, Hg and Zn than stipes, while other elements were distributed roughly equally between both morphological parts. B. luridus, B. magnificus and B. tomentipes grew in certain sites in Yunnan contained Ag, As, Ba, Cr, Hg, Ni, Sr or V at elevated concentration. A specific geochemistry of the soils type (latosols, lateritic red earths, and red and yellow earths in the Circum-Pacific Mercuriferous Belt of Southwestern China) can explain occurrence of some minerals at greater or elevated amount in mushrooms in Yunnan, while number of available research and data on mineral composition of mushrooms due to geochemical anomalies of soil parent material is so far little. Copyright © 2017 Elsevier Inc. All rights reserved.

Multielemental analysis of 20 mushroom species growing near a heavily trafficked road in Poland.

PubMed

Mleczek, M; Niedzielski, P; Kalač, P; Budka, A; Siwulski, M; Gąsecka, M; Rzymski, P; Magdziak, Z; Sobieralski, K

2016-08-01

The aim of this work was to compare 10 mostly edible aboveground and 10 wood-growing mushroom species collected near a heavily trafficked road (approximately 28,000 vehicles per 24 h) in Poland with regard to their capacity to accumulate 26 trace elements (Ag, Al, As, Au, B, Ba, Bi, Cd, Co, Cr, Cu, Fe, Ga, Ge, In, Li, Mn, Ni, Pb, Re, Sb, Se, Sr, Te, Tl, and Zn) in their fruit bodies in order to illustrate mushroom diversity in element accumulation. All analyses were performed using an inductively coupled plasma optical emission spectrometry (ICP-OES) spectrometer in synchronous dual view mode. The aboveground species had significantly higher levels of 12 elements, including Ag, As, Pb, and Se, compared to the wood-growing species. An opposite relationship was observed only for Au, Ba, and Sr. The results of principal component analysis (PCA) and hierarchical cluster analysis (HCA) implied some new relationships among the analyzed species and elements. Of the analyzed mushroom species, lead content in Macrolepiota procera would seem to pose a health risk; however, at present knowledge regarding lead bioaccessibility from mushrooms is quite limited.

Ultrasound-assisted microwave preparation of Ag-doped CdS nanoparticles.

PubMed

Ma, Jun; Tai, Guo'an; Guo, Wanlin

2010-03-01

Ag-doped CdS nanoparticles were synthesized by an ultrasound-assisted microwave synthesis method. The X-ray diffraction patterns reveal a structural evolution from cubic to hexagonal with increasing molar ratios of Ag(+)/Cd(2+) from 0% to 5%. It shows that the Ag-doped hexagonal CdS nanoparticles are polycrystal. The X-ray photoelectron spectroscopy of the CdS nanoparticles doping with 5% Ag(+) shows that the doped Ag in CdS is metallic. Simultaneously, the characteristic Raman peaks of the CdS nanoparticles enhance with increasing Ag(+) concentrations. The photocatalytic activity of different Ag-doped samples show a reasonable change due to different ratios of Ag which doped into CdS. Copyright 2009 Elsevier B.V. All rights reserved.

Crystal structure and luminescence properties of silver in AgM(PO{sub 3}){sub 3} (M = Mg, Zn, Ba) polyphosphates

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

Belharouak, I.; Parent, C.; Tanguy, B.

1999-06-01

The relationships between the crystal structures and the luminescent properties of the AgM(PO{sub 3}){sub 3} (M = Mg, Zn, Ba) polyphosphates are reported in comparison with those of AgPO{sub 3}. The structure of the magnesium and zinc phosphates is characterized by long polyphosphates chains connected to infinite chains of [AgO{sub 6}] and [MO{sub 6}] polyhedra sharing faces. The basic structural phosphate unit in AgBa(PO{sub 3}){sub 3} is a P{sub 3}O{sub 9} ring. Silver atoms are located in distorted octahedral sites. Two types of luminescent centers have been observed. The UV emission observed in all these materials is typical of isolatedmore » Ag{sup +} ions. The visible emission observed only in the zinc phosphate is probably the result of a silver-zinc association. 16 refs., 8 figs., 3 tabs.« less

Central Tibetan Plateau atmospheric trace metals contamination: A 500-year record from the Puruogangri ice core.

PubMed

Beaudon, Emilie; Gabrielli, Paolo; Sierra-Hernández, M Roxana; Wegner, Anna; Thompson, Lonnie G

2017-12-01

A ~500-year section of ice core (1497-1992) from the Puruogangri ice cap has been analyzed at high resolution for 28 trace elements (TEs: Ag, Al, As, Ba, Bi, Cd, Co, Cr, Cs, Cu, Fe, Ga, Li, Mg, Mn, Na, Nb, Ni, Pb, Rb, Sb, Sn, Sr, Ti, Tl, U, V and Zn) to assess different atmospheric contributions to the ice and provide a temporal perspective on the diverse atmospheric influences over the central Tibetan Plateau (TP). At least two volcanic depositions have significantly impacted the central TP over the past 500years, possibly originating from the Billy Mitchell (1580, Papua New Guinea) and the Parker Peak (1641, Philippines) eruptions. A decreasing aeolian dust input to the ice cap allowed the detection of an atmospheric pollution signal. The anthropogenic pollution contribution emerges in the record since the early 1900s (for Sb and Cd) and increases substantially after 1935 (for Ag, Zn, Pb, Cd and Sb). The metallurgy (Zn, Pb and steel smelting) emission products (Cd, Zn, Pb and Ag) from the former Soviet Union and especially from central Asia (e.g., Kyrgyzstan, Kazakhstan) likely enhanced the anthropogenic deposition to the Puruogangri ice cap between 1935 and 1980, suggesting that the westerlies served as a conveyor of atmospheric pollution to central Tibet. The impact of this industrial pollution cumulated with that of the hemispheric coal and gasoline combustion which are respectively traced by Sb and Pb enrichment in the ice. The Chinese steel production accompanying the Great Leap Forward (1958-1961) and the Chinese Cultural Revolution (1966-1976) is proposed as a secondary but proximal source of Pb pollution affecting the ice cap between 1958 and 1976. The most recent decade (1980-1992) of the enrichment time series suggests that Puruogangri ice cap recorded the early Sb, Cd, Zn, Pb and Ag pollution originating from developing countries of South (i.e., India) and East (i.e., China) Asia and transported by the summer monsoonal circulation. Published by Elsevier B.V.

Trace elements in winter snow of the Dolomites (Italy): a statistical study of natural and anthropogenic contributions.

PubMed

Gabrielli, P; Cozzi, G; Torcini, S; Cescon, P; Barbante, C

2008-08-01

Knowledge of the occurrence of trace elements deposited in fresh alpine snow is very limited. Although current sources of major ionic inorganic species have been well established, this is not the case for many trace elements. This manuscript attempts to reconstruct the origin of Ag, Ba, Bi, Cd, Co, Cr, Cu, Fe, Mo, Mn, Pb, Sb, Ti, U, V and Zn in winter surface snow, extensively collected in the Dolomites region (Eastern Alps, Italy). Sampling of surface snow was conducted weekly during the winter 1998 at 21 sites at altitudes ranging from approximately 1000 to approximately 3000 m. This led to a remarkable dataset of trace element concentrations in surface snow from low latitudes. Here we show a preliminary statistical investigation conducted on the 366 samples collected. It was found that V, Sb, Zn, Cd, Mo and Pb have a predominantly anthropogenic origin, linked to the road traffic in the alpine valleys and the nearby heavily industrialised area of the Po Valley. In addition, the occasionally strong Fe and Cr input may reflect the mechanical abrasion of ferrous components of the vehicles. However, much of the Fe along with Mn, U and Ti originates primarily from the geological background of the Dolomites. A marine contribution was found to be negligible for all the trace elements. The origin of other trace elements is less clear: Ag can be possibly attributed to a predominantly anthropogenic origin while Cr, Co, Cu and Ba are usually from crustal rocks but different than the Dolomites.

Dissipation of available benzo[a]pyrene in aging soil co-contaminated with cadmium and pyrene.

PubMed

Wang, Kai; Chen, Xin-xin; Zhu, Zhi-qiang; Huang, Hua-gang; Li, Ting-qiang; Yang, Xiao-e

2014-01-01

A microcosm experiment was conducted to investigate the dissipation of available benzo[a]pyrene (BaP) in soils co-contaminated with cadmium (Cd) and pyrene (PYR) during aging process. The available residue of BaP in soil was separated into desorbing and non-desorbing fractions. The desorbing fraction contributed more to the dissipation of available BaP than the non-desorbing fraction did. The concentration of bound-residue fraction of BaP was quite low across all treatments. Within the duration of this study (250 days), transformation of BaP from available fractions to bound-residue fraction was not observed. Microbial degradation was the dominant mechanism of the dissipation of available BaP in the soil. The dissipation of available BaP was significantly inhibited with the increment in Cd level in the soil. The addition of PYR (250 mg kg(-1)) remarkably promoted the dissipation of available BaP without reducing Cd availability in the soil. The calculated half-life of available BaP in the soil prolonged with the increment in Cd level; however, the addition of PYR shortened the half-life of available BaP by 13.1, 12.7, and 32.8% in 0.44, 2.56, and 22 mg Cd kg(-1) soils, respectively. These results demonstrated that the inhibiting effect of Cd and the promoting effect of PYR on the dissipation of available BaP were competitive. Therefore, this study shows that the bioremediation process of BaP can be more complicated in co-contaminated soils.

Anomalous metal concentrations in soil and till at the Ballinalack Zn-Pb deposit, Ireland

NASA Astrophysics Data System (ADS)

Kalveram, Ann-Kristin; McClenaghan, Seán H.; Kamber, Balz S.

2017-04-01

Metals such as zinc, iron, arsenic and lead are commonly found in low concentrations within soils. These signatures may occur as a result of natural dispersion from metal-bearing geological formations and (or) from anthropogenic sources. Prior to investigating any high or anomalous concentrations of metals in the surficial environment, it is important to reconcile potential sources of metals and verify whether element anomalies are in response to buried mineralization. Here we show how to distinguish true elevated concentrations from naturally occurring variations within a soil system. The research area is situated above the limestone-hosted Ballinalack Zn-Pb deposit in the central Irish Midlands. To investigate the pedogenesis and its related geochemical signature, top of the till and the BC soil horizon were sampled. Although the area can be described as pasture land, it does not preclude previous anthropogenic influences from former agricultural use and local small scale peat harvesting. For the soil BC horizon as well as in the top of the till, aqua regia-digestible element concentrations vary significantly and locally reach anomalous levels: Zn (median: 104 ppm; range: 27 - 13150 ppm), Pb (median: 16 ppm; range: 2 - 6430 ppm), As (median: 7.7 ppm; range: 1.4 - 362 ppm), Ag (median: 0.12 ppm; range: 0.04 - 19.9 ppm), Ba (median: 40 ppm; range: 10 - 1230 ppm), Cd (median: 1.5 ppm; range: 0.2 - 68 ppm), Co (median: 7.3 ppm; range: 0.5 - 22 ppm), Ni (median: 37 ppm; range: 3 - 134 ppm), Fe (median: 17900 ppm; range: 5000 - 52300 ppm), Ga (median: 2.4 ppm; range: 0.3 - 7.6 ppm), Sb (median: 1.2 ppm; range: 0.1 - 197 ppm) and Tl (median: 0.3 ppm; range: 0.02 - 8.6 ppm). Comparison with background levels from the area and grouped according to underlying geology, enrichment factor calculations (against Nb and Zr) indicate an elemental response to metalliferous-bearing bedrock. These results confirm that soil anomalies of Zn, Pb, As, Ag, Ba, Cd, Ni, Sb and Tl, are consistent with the characteristics of buried Waulsortian-hosted sulphide mineralization; furthermore, Mo, Se, Sn and V are anomalous. Principal component analysis reveals a strong geochemical relationship between Ag, As, Ba, Cd, Pb, Sb, Tl and Zn in soils, representing metal dispersion from a shallow sulphide lens underneath till and soil horizons. Results of laser ablation ICP-MS analyses of pyrite and sphalerite from the Ballinalack deposit confirm this geochemical relationship. These outcomes have helped to distinguish between true geological anomalies and possible anthropogenic inputs, an important consideration for any mineral exploration activities on cultivated land.

Inhalable Andrographolide-β-cyclodextrin Inclusion Complexes for Treatment of Staphylococcus aureus Pneumonia by Regulating Immune Responses.

PubMed

Zhang, Tongtong; Zhu, Lifei; Li, Miao; Hu, Yuzhen; Zhang, Erfeng; Jiang, Qingcheng; Han, Guang; Jin, Yiguang

2017-05-01

Bacterial pneumonia is a serious disease with high mortality if no appropriate and immediate therapy is available. Andrographolide (AG) is an anti-inflammatory agent extracted from a traditional Chinese herb andrographis paniculata. Oral AG tablets and pills are clinically applied for treatment of upper respiratory tract infections. However, the low solubility and bioavailability of AG lead to high doses and long-term therapy. Here we developed an andrographolide-β-cyclodextrin inclusion complex (AG-β-CD) for inhalation therapy of Staphylococcus aureus pneumonia. AG-β-CD was identified with X-ray diffraction and FT-IR. Surprisingly, both AG-β-CD and AG showed little in vitro anti-S. aureus activity. However, pulmonary delivery of AG, AG-β-CD, or penicillin had significant anti-S. aureus pneumonia effects. Leukocytes, neutrophils, white blood cells, total proteins, TNF-α, IL-6, NF-κB p65 expression, and bacterial colonies in the bronchoalveolar lavage fluids were detected. Pulmonary delivery of AG and AG-β-CD led to bacterial inhibition and inflammation alleviation by regulating immune responses, while penicillin only killed bacteria without significant immune regulation. Moreover, the antipneumonia activity of AG-β-CD was much higher than that of AG, probably resulting from locally accelerated AG dissolution due to β-CD inclusion. The aerodynamic diameter of AG-β-CD powders was 2.03 μm, suitable for pulmonary delivery. Inhalable AG-β-CD is a promising antibacterial and anti-inflammatory medicine for the treatment of S. aureus pneumonia by regulating immune responses, and the effect is enhanced by β-CD inclusion. AG and its formulations might be potent weapons against the resistant bacterial pneumonia due to their specific mechanism in the future.

Helminth antigens selectively differentiate unsensitized CD45RA+ CD4+ human T cells in vitro.

PubMed

Steel, C; Nutman, T B

1998-01-01

Human filarial helminth infections are characterized by type 2 immune responses to parasite Ag that can persist for the life of the individual; one possible cause for this may be prenatal exposure to the blood-borne microfilarial (Mf) stage of the parasite. To examine the relationship between early exposure to filarial Ag and subsequent immune responsiveness, CD45RA+ CD4+ cells frp, normal unsensitized donors were stimulated in vitro with soluble microfilarial Ag (MfAg) from the filarial parasite Brugia malayi in the presence of APCs. MfAg alone induced proliferation and IFN-gamma and IL-5 production in unsensitized CD45RA+ CD4+ cells, demonstrating the ability of filarial Ags to prime naive T cells in the absence of exogenous cytokines and dendritic cells. Adding exogenous cytokine(s) (particularly IL-12 and IL-4) during priming was able to alter the MfAg-specific responses of CD45RA+ CD4+ cells as well as subsequent responses to Ag. Interestingly, priming solely with MfAg led to enhanced IL-5 production following Ag restimulation, suggesting that MfAg preferentially primes for type 2 responses. These data demonstrate that filarial Ags by themselves can specifically prime CD45RA+ CD4+ cells in vitro and do so in such a way as to deviate the immune response.

A Data Mining Approach to Improve Inorganic Characterization of Amanita ponderosa Mushrooms.

PubMed

Salvador, Cátia; Martins, M Rosário; Vicente, Henrique; Caldeira, A Teresa

2018-01-01

Amanita ponderosa are wild edible mushrooms that grow in some microclimates of Iberian Peninsula. Gastronomically this species is very relevant, due to not only the traditional consumption by the rural populations but also its commercial value in gourmet markets. Mineral characterisation of edible mushrooms is extremely important for certification and commercialization processes. In this study, we evaluate the inorganic composition of Amanita ponderosa fruiting bodies (Ca, K, Mg, Na, P, Ag, Al, Ba, Cd, Cr, Cu, Fe, Mn, Pb, and Zn) and their respective soil substrates from 24 different sampling sites of the southwest Iberian Peninsula (e.g., Alentejo, Andalusia, and Extremadura). Mineral composition revealed high content in macroelements, namely, potassium, phosphorus, and magnesium. Mushrooms showed presence of important trace elements and low contents of heavy metals within the limits of RDI. Bioconcentration was observed for some macro- and microelements, such as K, Cu, Zn, Mg, P, Ag, and Cd. A. ponderosa fruiting bodies showed different inorganic profiles according to their location and results pointed out that it is possible to generate an explanatory model of segmentation, performed with data based on the inorganic composition of mushrooms and soil mineral content, showing the possibility of relating these two types of data.

A Data Mining Approach to Improve Inorganic Characterization of Amanita ponderosa Mushrooms

PubMed Central

Salvador, Cátia; Martins, M. Rosário

2018-01-01

Amanita ponderosa are wild edible mushrooms that grow in some microclimates of Iberian Peninsula. Gastronomically this species is very relevant, due to not only the traditional consumption by the rural populations but also its commercial value in gourmet markets. Mineral characterisation of edible mushrooms is extremely important for certification and commercialization processes. In this study, we evaluate the inorganic composition of Amanita ponderosa fruiting bodies (Ca, K, Mg, Na, P, Ag, Al, Ba, Cd, Cr, Cu, Fe, Mn, Pb, and Zn) and their respective soil substrates from 24 different sampling sites of the southwest Iberian Peninsula (e.g., Alentejo, Andalusia, and Extremadura). Mineral composition revealed high content in macroelements, namely, potassium, phosphorus, and magnesium. Mushrooms showed presence of important trace elements and low contents of heavy metals within the limits of RDI. Bioconcentration was observed for some macro- and microelements, such as K, Cu, Zn, Mg, P, Ag, and Cd. A. ponderosa fruiting bodies showed different inorganic profiles according to their location and results pointed out that it is possible to generate an explanatory model of segmentation, performed with data based on the inorganic composition of mushrooms and soil mineral content, showing the possibility of relating these two types of data. PMID:29623092

II-I2-IV-VI4 (II = Sr,Ba; I = Cu,Ag; IV = Ge,Sn; VI = S,Se): Earth-Abundant Chalcogenides for Thin Film Photovoltaics

NASA Astrophysics Data System (ADS)

Zhu, Tong; Huhn, William P.; Shin, Donghyeop; Mitzi, David B.; Blum, Volker; Saparov, Bayrammurad

Chalcogenides such as CdTe, CIGSSe, and CZTSSe are successful for thin film photovoltaics (PV) but contain elements that are rare, toxic, or prone to the formation of detrimental antisite disorder. Recently, the BaCu2SnS4-xSex system has been shown to offer a prospective path to circumvent these problems. While early prototypes show efficiencies of a few percent, many avenues remain to optimize the materials, including the underlying chemical composition. In this work, we explore 16 compounds II-I2-IV-VI4 to help identify new candidate materials for PV, with predictions based on both known experimental and computationally derived structures that belong to five different space groups. We employ hybrid density functional theory (HSE06) to explore the band gap tunability by substituting different elements, and other characteristics such as the effective mass and the absorption coefficient. Compounds containing Cu (rather than Ag) are found to have direct or nearly direct band gaps. Depending on the compound, replacing S with Se leads to a decrease of the predicted band gaps by 0.2-0.8 eV and to somewhat decreasing hole effective masses.

Background concentrations and reference values for heavy metals in soils of Cuba.

PubMed

Alfaro, Mirelys Rodríguez; Montero, Alfredo; Ugarte, Olegario Muñiz; do Nascimento, Clístenes Williams Araújo; de Aguiar Accioly, Adriana Maria; Biondi, Caroline Miranda; da Silva, Ygor Jacques Agra Bezerra

2015-01-01

The potential threat of heavy metals to human health has led to many studies on permissible levels of these elements in soils. The objective of this study was to establish quality reference values (QRVs) for Cd, Pb, Zn, Cu, Ni, Cr, Fe, Mn, As, Hg, V, Ba, Sb, Ag, Co, and Mo in soils of Cuba. Geochemical associations between trace elements and Fe were also studied, aiming to provide an index for establishing background concentrations of metals in soils. Surface samples of 33 soil profiles from areas of native forest or minimal anthropic influence were collected. Samples were digested (USEPA method 3051A), and the metals were determined by ICP-OES. The natural concentrations of metals in soils of Cuba followed the order Fe > Mn > Ni > Cr > Ba > V > Zn > Cu > Pb > Co > As > Sb > Ag > Cd > Mo > Hg. The QRVs found for Cuban soils were as follows (mg kg(-1)): Ag (1), Ba (111), Cd (0.6), Co (25), Cr (153), Cu (83), Fe (54,055), Mn (1947), Ni (170), Pb (50), Sb (6), V (137), Zn (86), Mo (0.1), As (19), and Hg (0.1). The average natural levels of heavy metals are above the global average, especially for Ni and Cr. The chemical fractionation of soil samples presenting anomalous concentrations of metals showed that Cu, Ni, Cr, Sb, and As have low bioavailability. This suggests that the risk of contamination of agricultural products via plant uptake is low. However, the final decision on the establishment of soil QRVs in Cuba depends on political, economic, and social issues and in-depth risk analyses considering all routes of exposure to these elements.

Heavy metals pollution levels and children health risk assessment of Yerevan kindergartens soils.

PubMed

Tepanosyan, Gevorg; Maghakyan, Nairuhi; Sahakyan, Lilit; Saghatelyan, Armen

2017-08-01

Children, the most vulnerable urban population group, are exceptionally sensitive to polluted environments, particularly urban soils, which can lead to adverse health effects upon exposure. In this study, the total concentrations of Ag, As, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Ti, V, and Zn were determined in 111 topsoil samples collected from kindergartens in Yerevan. The objectives of this study were to evaluate heavy metal pollution levels of kindergarten's soils in Yerevan, compare with national legal and international requirements on heavy metal contents in kindergarten soil, and assess related child health risk. Multivariate geostatistical analyses suggested that the concentrations of Ag, As, Ba, Cd, Cu, Hg, Mo, Pb, and Zn observed in the kindergarten's topsoil may have originated from anthropogenic sources, while Co, Cr, Fe, Mn, Ni, Ti, and V mostly come from natural sources. According to the Summary pollution index (Zc), 102 kindergartens belong to the low pollution level, 7 to the moderate and only 2 to the high level of pollution. Summary concentration index (SCI) showed that 109 kindergartens were in the allowable level, while 2 featured in the low level of pollution. The health risk assessment showed that in all kindergartens except for seven, non-carcinogenic risk for children was detected (HI>1), while carcinogenic risk from arsenic belongs to the very low (allowable) level. Cr and multi-element carcinogenic risk (RI) exceeded the safety level (1.0E- 06) in all kindergartens and showed that the potential of developing cancer, albeit small, does exist. Therefore, city's kindergartens require necessary remedial actions to eliminate or reduce soil pollution and heavy metal-induced health risks. Copyright © 2017 Elsevier Inc. All rights reserved.

Increased Zn/Glutathione Levels and Higher Superoxide Dismutase-1 Activity as Biomarkers of Oxidative Stress in Women with Long-Term Dental Amalgam Fillings: Correlation between Mercury/Aluminium Levels (in Hair) and Antioxidant Systems in Plasma

PubMed Central

Cabaña-Muñoz, María Eugenia; Parmigiani-Izquierdo, José María; Bravo-González, Luis Alberto; Kyung, Hee-Moon; Merino, José Joaquín

2015-01-01

Background The induction of oxidative stress by Hg can affect antioxidant enzymes. However, epidemiological studies have failed to establish clear association between dental fillings presence and health problems. Objectives To determine whether heavy metals (in hair), antioxidant enzymes (SOD-1) and glutathione levels could be affected by the chronic presence of heavy metals in women who had dental amalgam fillings. Materials and Methods 55 hair samples (42 females with amalgam fillings and 13 female control subjects) were obtained. All subjects (mean age 44 years) who had dental amalgam filling for more than 10 years (average 15 years). Certain metals were quantified by ICP-MS (Mass Spectrophotometry) in hair (μg/g: Al, Hg, Ba, Ag, Sb, As, Be, Bi, Cd, Pb, Pt, Tl, Th, U, Ni, Sn, Ti) and SOD-1 and Glutathione (reduced form) levels in plasma. Data were compared with controls without amalgams, and analyzed to identify any significant relation between metals and the total number of amalgam fillings, comparing those with four or less (n = 27) with those with more than four (n = 15). As no significant differences were detected, the two groups were pooled (Amlgam; n = 42). Findings Hg, Ag, Al and Ba were higher in the amalgam group but without significant differences for most of the heavy metals analyzed. Increased SOD-1 activity and glutathione levels (reduced form) were observed in the amalgam group. Aluminum (Al) correlated with glutathione levels while Hg levels correlated with SOD-1. The observed Al/glutathione and Hg/SOD-1 correlation could be adaptive responses against the chronic presence of mercury. Conclusions Hg, Ag, Al and Ba levels increased in women who had dental amalgam fillings for long periods. Al correlated with glutathione, and Hg with SOD-1. SOD-1 may be a possible biomarker for assessing chronic Hg toxicity. PMID:26076368

Encapsulation of boswellic acid with β- and hydroxypropyl-β-cyclodextrin: Synthesis, characterization, in vitro drug release and molecular modelling studies

NASA Astrophysics Data System (ADS)

Tambe, Amruta; Pandita, Nancy; Kharkar, Prashant; Sahu, Niteshkumar

2018-02-01

Boswellic acids (BAs) are a group of pentacyclic triterpenes present in gum-resin of Boswellia serrata. They are well known for their anti-inflammatory, hypolipidemic, immunomodulatory and anti-tumor activity, but they have poor aqueous solubility and limited bioavailability. In order to enhance their aqueous solubility, inclusion complexes of BAs with β-cyclodextrin (β-CD) and hydroxypropyl-β-cyclodextrin (HP-β-CD) were synthesized and their drug release profiles were studied. Molecular associations of β-CD and HP-β-CD with BAs were investigated by phase solubility studies. The stability constants were found to be 380.2 and 145.9 M-1 for BA: β-CD and BA: HP-β-CD inclusion complexes, respectively with AN- type curve. BA: β-CD and BA: HP-β-CD inclusion complexes were synthesized using kneading (KN), co-precipitation (CP) and solvent evaporation (SE) methods in 1:1 as well as 1:2 ratios. Further these were characterized by Fourier transform infrared (FTIR) spectrophotometry, Powder X-ray Diffraction (P-XRD) and Differential scanning calorimetric (DSC) analysis. FTIR analysis showed shifting of frequencies in complexes as compared to CDs and BAs. P-XRD data obtained for BA: β-CD complexes synthesized by CP and SE methods showed amorphous pattern. Also, DSC analysis showed a change in thermal behaviour for synthesized complexes. In vitro drug release studies of BA: β-CD complexes showed enhanced release with 1:2 complexes than 1:1 complexes at pH 1.2 and pH 6.8. Similarly, drug release enhancement was observed more with BA: HP-β-CD complexes in 1:2 ratio than 1:1. To understand the interaction of BAs with CD cavity molecular modelling studies were performed which favored 1:2 complex formation over 1:1 complexes. The study thus highlights that CDs can be used for solubility and dissolution enhancement of BAs.

Chitosan-stabilized Silver Nanoparticles for Colorimetric Assay of Mercury (II) Ions in aqueous system

NASA Astrophysics Data System (ADS)

Zarlaida, Fitri; Adlim, M.; Syukri Surbakti, M.; Fairuz Omar, Ahmad

2018-05-01

Mercury is considered as dangerous pollutant. Among the many form of mercury, the most stable and soluble in water is mercury (II) ions which it cause threat to human health and surroundings. Silver nanoparticles (AgNPs) used in this method were prepared by chitosan (chi) which act as stabilizing agent. The Chi-AgNPs has good dispersity with size ranging from 2.50 to 6.00 nm as shown by transmission electron microscopy (TEM) analysis and it is stable for 3 months. Color of Chi-AgNPs fades from brownish-yellow to colorless only with Hg2+ ions, but it shows no significant changes upon addition of other metal ions such as Al3+, Ba2+, Ca2+, Cd2+, Cr3+, Co2+, Cu2+, Fe2+, K+, Mg2+, Mn2+, Na+, Ni2+, Pb2+, and Zn2+. The detection limit for Hg2+ ions by bare-eye is estimated to be ∼1µM. This method can be used for sensing mercury(II) ions in numerous water samples.

Structural and superionic properties of Ag+-rich ternary phases within the AgI-MI2 systems

NASA Astrophysics Data System (ADS)

Hull, S.; Keen, D. A.; Berastegui, P.

2002-12-01

The effects of temperature on the crystal structure and ionic conductivity of the compounds Ag2CdI4, Ag2ZnI4 and Ag3SnI5 have been investigated by powder diffraction and impedance spectroscopy techniques. varepsilon-Ag2CdI4 adopts a tetragonal crystal structure under ambient conditions and abrupt increases in the ionic conductivity are observed at 407(2), 447(3) and 532(4) K, consistent with the sequence of transitions varepsilon-Ag2CdI 4 rightarrow beta-Ag2CdI 4 + beta-AgI + CdI2 rightarrow alpha-AgI + CdI2 rightarrow alpha-Ag2CdI4. Hexagonal beta-Ag2CdI4 is metastable at ambient temperature. The ambient-temperature beta phase of Ag2ZnI4 is orthorhombic and the structures of beta-Ag2CdI4 and beta-Ag2ZnI4 can, respectively, be considered as ordered derivatives of the wurtzite (beta) and zincblende (gamma) phases of AgI. On heating Ag2ZnI4, there is a 12-fold increase in ionic conductivity at 481(1) K and a further eightfold increase at 542(3) K. These changes result from decomposition of beta-Ag2ZnI4 into alpha-AgI + ZnI2, followed by the appearance of superionic alpha-Ag2ZnI4 at the higher temperature. The hexagonal crystal structure of alpha-Ag2ZnI4 is a dynamically disordered counterpart to the beta modification. Ag3SnI5 is only stable at temperatures in excess of 370(3) K and possesses a relatively high ionic conductivity (sigma approx 0.19Omega-1 cm-1 at 420 K) due to dynamic disorder of the Ag+ and Sn2+ within a cubic close packed I- sublattice. The implications of these findings for the wider issue of high ionic conductivity in AgI-MI2 compounds is discussed, with reference to recently published studies of Ag4PbI6 and Ag2HgI4 and new data for the temperature dependence of the ionic conductivity of the latter compound.

Removal of uranium from soil samples for ICP-OES analysis of RCRA metals

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

Wero, M.; Lederer-Cano, A.; Billy, C.

1995-12-01

Soil samples containing high levels of uranium present unique analytical problems when analyzed for toxic metals (Ag, As, Ba, Cd, Cr, Cu, Ni, Pb, Se and Tl) because of the spectral interference of uranium in the ICP-OES emission spectrometer. Methods to remove uranium from the digestates of soil samples, known to be high in uranium, have been developed that reduce the initial uranium concentration (1-3%) to less than 500 ppm. UTEVA ion exchange columns, used as an ICP-OES analytical pre-treatment, reduces uranium to acceptable levels, permitting good analytical results of the RCRA metals by ICP-OES.

Ag2S/CdS/TiO2 Nanotube Array Films with High Photocurrent Density by Spotting Sample Method.

PubMed

Sun, Hong; Zhao, Peini; Zhang, Fanjun; Liu, Yuliang; Hao, Jingcheng

2015-12-01

Ag2S/CdS/TiO2 hybrid nanotube array films (Ag2S/CdS/TNTs) were prepared by selectively depositing a narrow-gap semiconductor-Ag2S (0.9 eV) quantum dots (QDs)-in the local domain of the CdS/TiO2 nanotube array films by spotting sample method (SSM). The improvement of sunlight absorption ability and photocurrent density of titanium dioxide (TiO2) nanotube array films (TNTs) which were obtained by anodic oxidation method was realized because of modifying semiconductor QDs. The CdS/TNTs, Ag2S/TNTs, and Ag2S/CdS/TNTs fabricated by uniformly depositing the QDs into the TNTs via the successive ionic layer adsorption and reaction (SILAR) method were synthesized, respectively. The X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectrum (XPS) results demonstrated that the Ag2S/CdS/TNTs prepared by SSM and other films were successfully prepared. In comparison with the four films of TNTs, CdS/TNTs, Ag2S/TNTs, and Ag2S/CdS/TNTs by SILAR, the Ag2S/CdS/TNTs prepared by SSM showed much better absorption capability and the highest photocurrent density in UV-vis range (320~800 nm). The cycles of local deposition have great influence on their photoelectric properties. The photocurrent density of Ag2S/CdS/TNTs by SSM with optimum deposition cycles of 6 was about 37 times that of TNTs without modification, demonstrating their great prospective applications in solar energy utilization fields.

Second harmonic generation response of the cubic chalcogenides Ba( 6-x)Sr x[Ag( 4-y)Sn( y/4)](SnS 4) 4

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

Haynes, Alyssa S.; Liu, Te-Kun; Frazer, Laszlo

We synthesized the barium/strontium solid solution sequence Ba 6-xSr x[Ag( 4-y)Sn( y/4)](SnS 4) 4 for nonlinear optical (NLO) applications in the infrared (IR) via a flux synthesis route. All title compounds are isotypic, crystallizing in the cubic space group Imore » $$\\bar{_4}$$ 3d and are composed of a three-dimensional (3D) anionic framework of alternating corner-sharing SnS 4 and AgS 4 tetrahedra charge balanced by Ba and Sr. The shrinkage of Ba/Sr-S bond lengths causes the tetrahedra in the anionic framework to become more distorted, which results in a tunable band gap from 1.58 to 1.38 eV with increasing x values. The performance of the barium limit (x=0) is also superior to that of Sr (x=6), but surprisingly second harmonic generation (SHG) of the solid solution remains strong and is insensitive to the value of x over the range 0-3.8. Results show that the non-type-I phase-matched SHG produced by these cubic chalcogenides display intensities higher than the benchmark AgGaSe 2 from 600 to 1000 nm.« less

Biomonitoring of 33 Elements in Blood and Urine Samples from Coastal Populations in Sanmen County of Zhejiang Province.

PubMed

Zhang, Su-jing; Luo, Ru-xin; Ma, Dong; Zhuo, Xian-yi

2016-04-01

To determine the normal reference values of 33 elements, Ag, Al, As, Au, B, Ba, Be, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, Hg, Li, Mg, Mn, Mo, Ni, Pb, Rb, Sb, Se, Sr, Th, Ti, Tl, U, V, Zn and Zr, in the blood and urine samples from the general population in Sanmen County of Zhejiang province, a typical coastal area of eastern China. The 33 elements in 272 blood and 300 urine samples were determined by inductively coupled plasma-mass spectrometry (ICP-MS). The normality test of data was conducted using SPSS 17.0 Statistics. The data was compared with other reports. The normal reference values of the 33 elements in the blood and urine samples from the general population in Sanmen County were obtained, which of some elements were found to be similar with other reports, such as Co, Cu, Mn and Sr, while As, Cd, Hg and Pb were generally found to be higher than those previously reported. There was a wide variation between the reports from different countries in blood Ba. The normal reference values of the 33 elements in the blood and urine samples from the general population in Sanmen County are established, and successfully applied to two poisoning cases.

Natural and anthropic effects on hydrochemistry and major and trace elements in the water mass of a Spanish Pyrenean glacial lake set.

PubMed

Santolaria, Zoe; Arruebo, Tomás; Pardo, Alfonso; Rodríguez-Casals, Carlos; Matesanz, José María; Lanaja, Francisco Javier; Urieta, José Santiago

2017-07-01

This study presents the key hydrochemical characteristics and concentration levels of major (Ca, Mg, Na, Si, K, Sr, Fe) and trace (Ba, Sc, Cr, Mn, Al, As, Li, Co, Cu, U, Pb, Hg, Au, Sn, Zn, Cd, Ag, Ni) elements in the water mass of four selected Pyrenean cirque glacial lakes (Sabocos, Baños, Truchas and Escalar tarns) with different catchment features, between 2010 and 2013. Resulting data set is statistically analyzed to discriminate between the natural or anthropic origin of the elements. Analyses indicate that in all cases, the main source of most major and trace elements is geological weathering, being thus individual bedrock composition the main driver of differences between lakes. Several anthropogenic sources of airborne Cu, Sc, Co, and Cr must be also considered. The shallowness of the lake is also a factor that may influence element cycling and concentration levels in its water mass. Concentrations of anthropogenic elements were low, comparable to those reported in other glacial lakes, way below the WHO, US EPA, EC, and Spanish legal limits for drinking water quality, indicating the absence of serious pollution. Toxic heavy metals Cd, Pb, Hg, and Zn were not detected in any of the tarns.

PIXE and ICP-MS Analysis of Andrographis Paniculata Medicinal Plant

NASA Astrophysics Data System (ADS)

Chandrasekhar Rao, J.; Naidu, B. G.; Sarita, P.; Srikanth, S.; Naga Raju, G. J.

2017-08-01

The concentrations of elements Li, Be, Al, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Ag, Cd, Ba, Pb and U in Andrographis Paniculata medicinal plant used in the treatment of Diabetes Mellitus were determined by using Particle Induced X-ray Emission (PIXE) and Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) techniques. This plant was collected from four different geographical locations in Andhra Pradesh, India in order to assess the regional variation of elemental concentrations. Appreciable levels of K, Ca, Cr, Mn, Cu and Zn determined in this plant can be correlated to the antidiabetic property of Andrographis Paniculata since these elements are known to regulate and potentiate insulin action. Presence of toxic elements As, Cd and Pb necessitates the adoption of precautionary measures while prescribing dosage of the herbal medicine prepared from this plant for the treatment diabetes mellitus.

The design of novel visible light driven Ag/CdO as smart nanocomposite for photodegradation of different dye contaminants

NASA Astrophysics Data System (ADS)

Saravanakumar, K.; Muthuraj, V.; Jeyaraj, M.

2018-01-01

In this paper, we report a novel visible light driven Ag/CdO photocatalyst, fabricated for the first time via one pot hydrothermal method and further applied for the photodegradation of two important exemplar water contaminants, Malachite green and Acid Orange 7. The microstructure, composition and optical properties of Ag/CdO nanocomposites were thoroughly investigated by various techniques. Scanning electron microscopy clearly shows that Ag NPs were strongly embedded between the CdO nanoparticles. Among the series of synthesized Ag/CdO nanocomposites, (5%) Ag/CdO nanocomposite possesses enhanced photocatalytic activity. This result was attributed to the synergistic effect between Ag and CdO, and mainly Ag NPs can act as an electron trap site, which could reduce the recombination of the electron-hole and induce the visible light absorption. The active species trapping experiments implicate radOH and O2rad - radicals as the respective primary and secondary reactive species responsible for oxidative photodegradation of organic pollutants. On the basis of the results, a possible photocatalytic mechanism has also been proposed.

ZnO/Ag/CdO nanocomposite for visible light-induced photocatalytic degradation of industrial textile effluents.

PubMed

Saravanan, R; Mansoob Khan, M; Gupta, Vinod Kumar; Mosquera, E; Gracia, F; Narayanan, V; Stephen, A

2015-08-15

A ternary ZnO/Ag/CdO nanocomposite was synthesized using thermal decomposition method. The resulting nanocomposite was characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, UV-Vis spectroscopy, and X-ray photoelectron spectroscopy. The ZnO/Ag/CdO nanocomposite exhibited enhanced photocatalytic activity under visible light irradiation for the degradation of methyl orange and methylene blue compared with binary ZnO/Ag and ZnO/CdO nanocomposites. The ZnO/Ag/CdO nanocomposite was also used for the degradation of the industrial textile effluent (real sample analysis) and degraded more than 90% in 210 min under visible light irradiation. The small size, high surface area and synergistic effect in the ZnO/Ag/CdO nanocomposite is responsible for high photocatalytic activity. These results also showed that the Ag nanoparticles induced visible light activity and facilitated efficient charge separation in the ZnO/Ag/CdO nanocomposite, thereby improving the photocatalytic performance. Copyright © 2015 Elsevier Inc. All rights reserved.

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

Wen, Haiming; van Rooyen, Isabella J.

Here, detailed electron microscopy studies were performed to investigate the distribution and composition of fission products in the SiC layer of a tristructural isotropic coated particle exhibiting localized corrosion. Previous studies on this particle indicated that pure carbon areas in the SiC layer, resulting from localized corrosion of SiC by Pd, provide pathways for Ag, Cd and Cs migration. This study reveals the presence of Ag- and/or Cd-containing precipitates in un-corroded SiC areas. Ag/Cd may exist by themselves or coexist with Pd. Ag/Cd mainly transport along SiC grain boundaries. An Ag-Pd-Cd precipitate was identified at a stacking fault inside amore » SiC grain, suggesting that intragranular transport of Ag/Cd is possible. Ce is present with Pd or Pd-U in some precipitates >50 nm. U and Ce frequently coexist with each other, whereas Ag/Cd usually does not coexist with U or Ce. No Cs was detected in any precipitates in the areas examined.« less

Estimated Prevalence of Cryptococcus Antigenemia (CrAg) among HIV-Infected Adults with Advanced Immunosuppression in Namibia Justifies Routine Screening and Preemptive Treatment.

PubMed

Sawadogo, Souleymane; Makumbi, Boniface; Purfield, Anne; Ndjavera, Christophine; Mutandi, Gram; Maher, Andrew; Kaindjee-Tjituka, Francina; Kaplan, Jonathan E; Park, Benjamin J; Lowrance, David W

2016-01-01

Cryptococcal meningitis is common and associated with high mortality among HIV infected persons. The World Health Organization recommends that routine Cryptococcal antigen (CrAg) screening in ART-naïve adults with a CD4+ count <100 cells/μL followed by pre-emptive antifungal therapy for CrAg-positive patients be considered where CrAg prevalence is ≥3%. The prevalence of CrAg among HIV adults in Namibia is unknown. We estimated CrAg prevalence among HIV-infected adults receiving care in Namibia for the purpose of informing routine screening strategies. The study design was cross-sectional. De-identified plasma specimens collected for routine CD4+ testing from HIV-infected adults enrolled in HIV care at 181 public health facilities from November 2013 to January 2014 were identified at the national reference laboratory. Remnant plasma from specimens with CD4+ counts <200 cells/μL were sampled and tested for CrAg using the IMMY® Lateral Flow Assay. CrAg prevalence was estimated and assessed for associations with age, sex, and CD4+ count. A total of 825 specimens were tested for CrAg. The median (IQR) age of patients from whom specimens were collected was 38 (32-46) years, 45.9% were female and 62.9% of the specimens had CD4 <100 cells/μL. CrAg prevalence was 3.3% overall and 3.9% and 2.3% among samples with CD4+ counts of CD4+<100 cells/μL and 100-200 cells/μL, respectively. CrAg positivity was significantly higher among patients with CD4+ cells/μL < 50 (7.2%, P = 0.001) relative to those with CD4 cells/μL 50-200 (2.2%). This is the first study to estimate CrAg prevalence among HIV-infected patients in Namibia. CrAg prevalence of ≥3.0% among patients with CD4+<100 cells/μL justifies routine CrAg screening and preemptive treatment among HIV-infected in Namibia in line with WHO recommendations. Patients with CD4+<100 cells/μL have a significantly greater risk for CrAg positivity. Revised guidelines for ART in Namibia now recommend routine screening for CrAg.

Anomalous thermal expansion behaviors in Sm-Ba-Cu-O superconductors

NASA Astrophysics Data System (ADS)

Okaji, Masahiro; Yamada, Naofumi; Mase, Atsushi; Ikuta, Hiroshi; Mizutani, Uichiro

2000-11-01

Linear thermal expansion coefficients α of c-axis oriented Ag-added Sm-Ba-Cu-O superconductors have been measured in the range of 10 - 300 K. The α showed a large bump along the c-axis and a large dent along the ab-plane around 170 - 260 K for the 2 wt% and 5 wt% Ag 2O specimens, but these anomalies essentially disappeared with thermal cycles between room and cryogenic temperatures. In contrast, there were no significant anomalies for the 10 wt% and 20 wt% Ag 2O specimens. These results suggest that the addition of Ag 2O should moderate deformation and help to increase mechanical strength.

Effect of silver doping on the elastic properties of CdS nanoparticles

NASA Astrophysics Data System (ADS)

Dey, P. C.; Das, R.

2018-05-01

CdS and Ag doped CdS (CdS/Ag) nanoparticles have been prepared via chemical method from a Cadmium acetate precursor and Thiourea. The synthesized CdS and CdS/Ag nanoparticles have been characterized by the X-ray Diffraction and High Resolution Transmission Electron Microscope. Here, these nanoparticles have been synthesized at room temperature and all the characterization have also been done at room temperature only. The XRD results reveal that the products are crystalline with cubic zinc blende structure. HRTEM images show that the prepared nanoparticles are nearly spherical in shape. Williamson-Hall method and Size-Strain Plot (SSP) have been used to study the individual contribution of crystalline sizes and lattice strain on the peak broadening of the CdS and CdS/Ag nanoparticles. The different modified model of Williamson-Hall method such as, uniform deformation model, uniform stress deformation model and uniform energy density deformation model and SSP method have been used to calculate the different physical parameter such as lattice strain, stress and energy density for all diffraction peaks of the XRD, corresponding to the CdS and silver doped CdS (CdS/Ag). The obtained results reveal that the average particle size of the prepared CdS and CdS/Ag nanoparticles estimated from the HRTEM images, Williamson-Hall analysis and SSP method are highly correlated with each other. Further, all these result confirms that doping of Ag significantly affects the elastic properties of CdS.

Structural and optoelectronic studies on Ag-CdS quantum dots

NASA Astrophysics Data System (ADS)

Ibrahim Mohammed S., M.; Gubari, Ghamdan M. M.; Huse, Nanasaheb P.; Dive, Avinash S.; Sharma, Ramphal

2018-05-01

In the present study, we have successfully deposited CdS quantum dot thin films and Ag doped CdS on a glass slide by simple and economical chemical bath deposition at room temperature. The X-ray diffraction method analysis reveals that CdS thin films exhibit hexagonal structure when compared with standard JCPDS data. The estimated average crystallite size of the quantum dots and resulted in the least crystallite size of ˜9 nm. a comparison between the optical and electrical properties of the films before and after doping Ag was made through measuring and analyzing the curves for UV and I-V. From UV absorption spectra we observed that the samples exhibited a band edge near ˜400 nm with a slight deviation with the presence of excitonic peak for both CdS and Ag doped CdS. The presence of excitonic peak may be referred to the formation of quantum dots. The calculated band gap energy of thin films was found to be 3.45 eV and 3.15 eV for both CdS and Ag doped CdS thin films respectively, where the optical absorption spectra of Ag doped CdS nanoparticles also exhibit shift with respect to that of CdS quantum dots thin films. The photosensitive of CdS thin films show an increase in photocurrent when Ag doped CdS.

Nanostructural Characterization of Low Resistance Joints Using Ag Pastes for GdBa2Cu3O7-x Coated Conductors

NASA Astrophysics Data System (ADS)

Kato, Tomohiro; Machi, Takato; Yokoe, Daisaku; Yoshida, Ryuji; Kato, Takeharu; Izumi, Teruo; Hirayama, Tsukasa; Shiohara, Yuh

2017-07-01

GdBa2Cu3O7-x coated conductors were splice jointed by a face-to-face manner using a paste containing nano-sized Ag particles under a pressure of about 50 MPa at 150 °C for 1 hr. The low electrical resistance of 6 nΩ at the joint was attained. Nanostructural characterizations of the starting Ag paste and the jointed region of the coated conductors were carried out using scanning electron microscopy and transmission electron microscopy. The size of the Ag particles in the starting pastes were confirmed to be a few tens of nanometers in diameter. The size of Ag particles became larger during the jointing process. Both the surfaces of the stabilizing Ag layers were partially bonded by the Ag particles. No oxides or other elements were detected in the region of the bonding parts.

Transfer of volatiles and metals from mafic to felsic magmas in composite magma chambers: An experimental study

NASA Astrophysics Data System (ADS)

Guo, Haihao; Audétat, Andreas

2017-02-01

In order to determine the behavior of metals and volatiles during intrusion of mafic magma into the base of silicic, upper crustal magma chambers, fluid-rock partition coefficients (Dfluid/rock) of Li, B, Na, S, Cl, K, Mn, Fe, Rb, Sr, Ba, Ce, Cu, Zn, Ag, Cd, Mo, As, Se, Sb, Te, W, Tl, Pb and Bi were determined experimentally at 2 kbar and 850 °C close to the solidus of mafic magma. In a first step, volatile-bearing mafic glasses were prepared by melting a natural basaltic trachyandesite in the presence of volatile-bearing fluids at 1200 °C/10 kbar in piston cylinder presses. The hydrous glasses were then equilibrated in subsequent experiments at 850 °C/2 kbar in cold-seal pressure vessels, which caused 80-90% of the melt to crystallize. After 0.5-2.0 days of equilibration, the exsolved fluid was trapped by means of in-situ fracturing in the form of synthetic fluid inclusions in quartz. Both the mafic rock residue and the fluid inclusions were subsequently analyzed by laser-ablation ICP-MS for major and trace elements. Reverse experiments were conducted by equilibrating metal-bearing aqueous solutions with rock powder and then trapping the fluid. In two additional experiments, information on relative element mobilities were obtained by reacting fluids that exsolved from crystallizing mafic magma with overlying silicic melts. The combined results suggest that under the studied conditions S, Cl, Cu, Se, Br, Cd and Te are most volatile (Dfluid/rock >10), followed by Li, B, Zn, As, Ag, Sb, Cs, W, Tl, Pb and Bi (Dfluid/rock = 1-10). Less volatile are Na, Mg, K, Ca, Mn, Fe, Rb, Sr, Mo and Rb (Dfluid/rock 0.1-1), and the least fluid-mobile elements are Al, Si, Ti, Zr, Ba and Ce (Dfluid/rock <0.1). This trend is broadly consistent with relative element volatilities determined on natural high-temperature fumarole gases, although some differences exist. Based on the volatility data and measured mineral-melt and sulfide-melt partition coefficients, volatile fluxing in felsic natural samples may be identified by Cu, Se, Te and Cd-enrichment in magmatic sulfides, and by As, Se, Cd and Bi-enrichment in magmatic apatite.

Green synthesis of silver nanoparticles using Cordia dichotoma fruit extract and its enhanced antibacterial, anti-biofilm and photo catalytic activity

NASA Astrophysics Data System (ADS)

Bharathi, Devaraj; Vasantharaj, Seerangaraj; Bhuvaneshwari, V.

2018-05-01

The present study describes the antibacterial, anti-biofilm and photo catalytic activity of silver nanoparticles synthesized using Cordia dichotoma fruits (Cd-AgNPs) for the first time. The phyto-synthesized Cd-AgNPs were characterized by UV-Visible spectroscopy, Field emission-scanning electron microscopy (FE-SEM), Transmission electron microscopy (TEM), Energy dispersive x-ray spectrometer (EDX), Fourier transform infrared spectroscopy (FT-IR), and x-ray diffraction (XRD). FE-SEM and TEM observation showed that the average size of 2–60 nm with spherical shape of Cd-AgNPs and the presence of phyto-compounds which are responsible for capping and reduction were studied by FT-IR. XRD studies revealed the face-centered cubic structure of Cd-AgNPs. The synthesized Cd-AgNPs showed significant antibacterial activity against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli, assayed using agar well diffusion method. Phyto-synthesized Cd-AgNPs exhibited more than 90% inhibition of biofilm activity formed by S. aureus and E. coli. Furthermore, photocatalytic degradation of crystal violet (CV) under UV light irradiation using Cd-AgNPs was performed. Synthesized Cd-AgNPs exhibited ∼85% degradation activity for CV. Collectively, our findings suggest that C.dichotoma is a green source for the eco-friendly synthesis of Cd-AgNPs, which further can be used as a novel biocidal agent against bacterial pathogens and a potent photo catalytic agent.

Annual suspended sediment and trace element fluxes in the Mississippi, Columbia, Colorado, and Rio Grande drainage basins

USGS Publications Warehouse

Horowitz, A.J.; Elrick, K.A.; Smith, J.J.

2001-01-01

Suspended sediment, sediment-associated, total trace element, phosphorus (P), and total organic carbon (TOC) fluxes were determined for the Mississippi, Columbia, Rio Grande, and Colorado Basins for the study period (the 1996, 1997, and 1998 water years) as part of the US Geological Survey's redesigned National Stream Quality Accounting Network (NASQAN) programme. The majority (??? 70%) of Cu, Zn, Cr, Ni, Ba, P, As, Fe, Mn, and Al are transported in association with suspended sediment; Sr transport seems dominated by the dissolved phase, whereas the transport of Li and TOC seems to be divided equally between both phases. Average dissolved trace element levels are markedly lower than reported during the original NASQAN programme; this seems due to the use of 'clean' sampling, processing, and analytical techniques rather than to improvements in water quality. Partitioning between sediment and water for Ag, Pb, Cd, Cr, Co, V, Be, As, Sb, Hg, and Ti could not be estimated due to a lack of detectable dissolved concentrations in most samples. Elevated suspended sediment-associated Zn levels were detected in the Ohio River Basin and elevated Hg levels were detected in the Tennessee River, the former may affect the mainstem Mississippi River, whereas the latter probably do not. Sediment-associated concentrations of Ag, Cu, Pb, Zn, Cd, Cr, Co, Ba, Mo, Sb, Hg, and Fe are markedly elevated in the upper Columbia Basin, and appear to be detectable (Zn, Cd) as far downstream as the middle of the basin. These elevated concentrations seem to result from mining and/or mining-related activities. Consistently detectable concentrations of dissolved Se were found only in the Colorado River Basin. Calculated average annual suspended sediment fluxes at the mouths of the Mississippi and Rio Grande Basins were below, whereas those for the Columbia and Colorado Basins were above previously published annual values. Downstream suspended sediment-associated and total trace element fluxes increase in the Mississippi and Columbia Basins, whereas fluxes markedly decrease in the Colorado Basin. No consistent pattern in trace element fluxes was detected in the Rio Grande Basin.

Antigen targeting to antigen-presenting cells enhances presentation to class II-restricted T lymphocytes.

PubMed Central

Scardino, A; Paroli, M; De Petrillo, G; Michel, M L; Barnaba, V

1994-01-01

Receptor-mediated uptake increases by several orders of magnitude the efficiency of APC to internalize Ag, and is stringently required for the Ag-presenting function of T lymphocytes due to their inability to take up Ag non-specifically. We have previously reported that hepatitis B envelope antigen (HBenvAg) can be internalized by T cells via transferrin receptor (TfR). To evaluate if Ag targeting to receptors expressed on APC could be an effective tool for promoting Ag uptake and presentation, we tested the capacity of activated T cells not expressing TfR to induce HBenvAg-specific T-cell responses when pulsed with a hybrid particle containing HBenvAg coupled to gp120 of human immunodeficiency virus (HIV), exploiting the ability of gp120 to bind to CD4 receptor. We found that CD4+/TfR- T cells pulsed either with the hybrid particle or peptide (S193-207) but not with S, L Ag, a recombinant form of HBenvAg, induced a specific proliferative response of a T-cell clone recognizing peptide (S193-207) of HBenvAg. The finding that the addition of anti-CD4 monoclonal antibody (mAb) before the pulsing of CD4+/TfR- T cells with the hybrid particle drastically blocked the specific T-cell response, together with the finding that CD8+/TfR- T cells were unable to serve as APC even if pulsed with this molecule, demonstrated that CD4 receptor was crucial for the HBenvAg internalization. On the other hand, HBenvAg presentation by CD4+/TfR+ T cells pulsed with the hybrid particle was inhibited only when both anti-CD4 and anti-TfR were added before the pulsing. These results suggest that Ag targeting to APC receptors may be usefully exploited to improve Ag-presentation efficiency in potential immunotherapeutic approaches. PMID:7907575

The design of novel visible light driven Ag/CdO as smart nanocomposite for photodegradation of different dye contaminants.

PubMed

Saravanakumar, K; Muthuraj, V; Jeyaraj, M

2018-01-05

In this paper, we report a novel visible light driven Ag/CdO photocatalyst, fabricated for the first time via one pot hydrothermal method and further applied for the photodegradation of two important exemplar water contaminants, Malachite green and Acid Orange 7. The microstructure, composition and optical properties of Ag/CdO nanocomposites were thoroughly investigated by various techniques. Scanning electron microscopy clearly shows that Ag NPs were strongly embedded between the CdO nanoparticles. Among the series of synthesized Ag/CdO nanocomposites, (5%) Ag/CdO nanocomposite possesses enhanced photocatalytic activity. This result was attributed to the synergistic effect between Ag and CdO, and mainly Ag NPs can act as an electron trap site, which could reduce the recombination of the electron-hole and induce the visible light absorption. The active species trapping experiments implicate OH and O 2 - radicals as the respective primary and secondary reactive species responsible for oxidative photodegradation of organic pollutants. On the basis of the results, a possible photocatalytic mechanism has also been proposed. Copyright © 2017 Elsevier B.V. All rights reserved.

Early recycling compartment trafficking of CD1a is essential for its intersection and presentation of lipid antigens.

PubMed

Cernadas, Manuela; Cavallari, Marco; Watts, Gerald; Mori, Lucia; De Libero, Gennaro; Brenner, Michael B

2010-02-01

A major step in understanding differences in the nature of Ag presentation was the realization that MHC class I samples peptides transported to the endoplasmic reticulum from the cytosol, whereas MHC class II samples peptides from lysosomes. In contrast to MHC class I and II molecules that present protein Ags, CD1 molecules present lipid Ags for recognition by specific T cells. Each of the five members of the CD1 family (CD1a-e) localizes to a distinct subcompartment of endosomes. Accordingly, it has been widely assumed that the distinct trafficking of CD1 isoforms must also have evolved to enable them to sample lipid Ags that traffic via different routes. Among the CD1 isoforms, CD1a is unusual because it does not have a tyrosine-based cytoplasmic sorting motif and uniquely localizes to the early endocytic recycling compartment. This led us to predict that CD1a might have evolved to focus on lipids that localize to early endocytic/recycling compartments. Strikingly, we found that the glycolipid Ag sulfatide also localized almost exclusively to early endocytic and recycling compartments. Consistent with colocalization of CD1a and sulfatide, wild-type CD1a molecules efficiently presented sulfatide to CD1a-restricted, sulfatide-specific T cells. In contrast, CD1a:CD1b tail chimeras, that retain the same Ag-binding capacity as CD1a but traffic based on the cytoplasmic tail of CD1b to lysosomes, failed to present sulfatide efficiently. Thus, the intracellular trafficking route of CD1a is essential for efficient presentation of lipid Ags that traffic through the early endocytic and recycling pathways.

Cluster Chemistry in Electron-Poor Ae-Pt-Cd Systems (Ae=Ca, Sr, Ba): (Sr,Ba)Pt2Cd4, Ca6Pt8Cd16, and Its Known Antitype Er6Pd16Sb8

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

Samal, Saroj L.; Gulo, Fakhili; Corbett, John D.

Three new ternary polar intermetallic compounds, cubic Ca6Pt8Cd16, and tetragonal (Sr, Ba)Pt2Cd4 have been discovered during explorations of the Ae–Pt–Cd systems. Cubic Ca6Pt8Cd16 (Fm-3m, Z = 4, a = 13.513(1) Å) contains a 3D array of separate Cd8 tetrahedral stars (TS) that are both face capped along the axes and diagonally bridged by Pt atoms to generate the 3D anionic network Cd8[Pt(1)]6/2[Pt(2)]4/8. The complementary cationic surface of the cell consists of a face-centered cube of Pt(3)@Ca6 octahedra. This structure is an ordered ternary variant of Sc11Ir4 (Sc6Ir8Sc16), a stuffed version of the close relative Na6Au7Cd16, and a network inverse ofmore » the recent Er6Sb8Pd16 (compare Ca6Pt8Cd16). The three groups of elements each occur in only one structural version. The new AePt2Cd4, Ae = Sr, Ba, are tetragonal (P42/mnm,Z = 2, a ≈ 8.30 Å, c ≈ 4.47 Å) and contain chains of edge-sharing Cd4 tetrahedra along c that are bridged by four-bonded Ba/Sr. LMTO-ASA and ICOHP calculation results and comparisons show that the major bonding (Hamilton) populations in Ca6Pt8Cd16 and Er6Sb8Pd16 come from polar Pt–Cd and Pd–Sb interactions, that Pt exhibits larger relativistic contributions than Pd, that characteristic size and orbital differences are most evident for Sb 5s, Pt8, and Pd16, and that some terms remain incomparable, Ca–Cd versus Er–Pd.« less

The Role of Annealing Process in Ag-Based BaSnO3 Multilayer Thin Films.

PubMed

Wu, Muying; Yu, Shihui; He, Lin; Yang, Lei; Zhang, Weifeng

2016-12-01

The BaSnO3/Ag/BaSnO3 multilayer structure was designed and fabricated on a quartz glass by magnetron sputtering, followed by an annealing process at a temperature from 150 to 750 °C in air. In this paper, we investigated the influence of the annealing temperature on the structural, optical, and electrical properties of the multilayers and proposed the mechanisms of conduction and transmittance. The maximum value of the figure of merit of 31.8 × 10(-3) Ω(-1) was achieved for the BaSnO3/Ag/BaSnO3 multilayer thin films annealed at 150 °C, while the average optical transmittance in the visible ranges was >84 %, the resistivity was 5.71 × 10(-5) Ω cm, and the sheet resistance was 5.57 Ω/sq. When annealed at below 600 °C, the values of resistivity and transmittance of the multilayers were within an acceptable range (resistivity <5.0 × 10(-4) Ω cm, transmittance >80 %). The observed property of the multilayer film is suitable for the application of transparent conductive electrodes.

IL-5 promotes induction of antigen-specific CD4+CD25+ T regulatory cells that suppress autoimmunity.

PubMed

Tran, Giang T; Hodgkinson, Suzanne J; Carter, Nicole M; Verma, Nirupama D; Plain, Karren M; Boyd, Rochelle; Robinson, Catherine M; Nomura, Masaru; Killingsworth, Murray; Hall, Bruce M

2012-05-10

Immune responses to foreign and self-Ags can be controlled by regulatory T cells (Tregs) expressing CD4 and IL-2Rα chain (CD25). Defects in Tregs lead to autoimmunity, whereas induction of Ag-specific CD4+CD25+ Tregs restores tolerance. Ag-specific CD4+CD25+ FOXP3+Tregs activated by the T helper type 2 (Th2) cytokine, IL-4, and specific alloantigen promote allograft tolerance. These Tregs expressed the specific IL-5Rα and in the presence of IL-5 proliferate to specific but not third-party Ag. These findings suggest that recombinant IL-5 (rIL-5) therapy may promote Ag-specific Tregs to mediate tolerance. This study showed normal CD4+CD25+ Tregs cultured with IL-4 and an autoantigen expressed Il-5rα. Treatment of experimental autoimmune neuritis with rIL-5 markedly reduced clinical paralysis, weight loss, demyelination, and infiltration of CD4+ (Th1 and Th17) CD8+ T cells and macrophages in nerves. Clinical improvement was associated with expansion of CD4+CD25+FOXP3+ Tregs that expressed Il-5rα and proliferated only to specific autoantigen that was enhanced by rIL-5. Depletion of CD25+ Tregs or blocking of IL-4 abolished the benefits of rIL-5. Thus, rIL-5 promoted Ag-specific Tregs, activated by autoantigen and IL-4, to control autoimmunity. These findings may explain how Th2 responses, especially to parasitic infestation, induce immune tolerance. rIL-5 therapy may be able to induce Ag-specific tolerance in autoimmunity.

Mid-Gap States and Normal vs Inverted Bonding in Luminescent Cu+- and Ag+-Doped CdSe Nanocrystals.

PubMed

Nelson, Heidi D; Hinterding, Stijn O M; Fainblat, Rachel; Creutz, Sidney E; Li, Xiaosong; Gamelin, Daniel R

2017-05-10

Mid-gap luminescence in copper (Cu + )-doped semiconductor nanocrystals (NCs) involves recombination of delocalized conduction-band electrons with copper-localized holes. Silver (Ag + )-doped semiconductor NCs show similar mid-gap luminescence at slightly (∼0.3 eV) higher energy, suggesting a similar luminescence mechanism, but this suggestion appears inconsistent with the large difference between Ag + and Cu + ionization energies (∼1.5 eV), which should make hole trapping by Ag + highly unfavorable. Here, Ag + -doped CdSe NCs (Ag + :CdSe) are studied using time-resolved variable-temperature photoluminescence (PL) spectroscopy, magnetic circularly polarized luminescence (MCPL) spectroscopy, and time-dependent density functional theory (TD-DFT) to address this apparent paradox. In addition to confirming that Ag + :CdSe and Cu + :CdSe NCs display similar broad PL with large Stokes shifts, we demonstrate that both also show very similar temperature-dependent PL lifetimes and magneto-luminescence. Electronic-structure calculations further predict that both dopants generate similar localized mid-gap states. Despite these strong similarities, we conclude that these materials possess significantly different electronic structures. Specifically, whereas photogenerated holes in Cu + :CdSe NCs localize primarily in Cu(3d) orbitals, formally oxidizing Cu + to Cu 2+ , in Ag + :CdSe NCs they localize primarily in 4p orbitals of the four neighboring Se 2- ligands, and Ag + is not oxidized. This difference reflects a shift from "normal" to "inverted" bonding going from Cu + to Ag + . The spectroscopic similarities are explained by the fact that, in both materials, photogenerated holes are localized primarily within covalent [MSe 4 ] dopant clusters (M = Ag + , Cu + ). These findings reconcile the similar spectroscopies of Ag + - and Cu + -doped semiconductor NCs with the vastly different ionization potentials of their Ag + and Cu + dopants.

A recent history of metal accumulation in the sediments of Rijeka harbor, Adriatic Sea, Croatia.

PubMed

Cukrov, Neven; Frančišković-Bilinski, Stanislav; Hlača, Bojan; Barišić, Delko

2011-01-01

We studied metal pollution in the sediments of Rijeka harbor, including anthropogenic influence during recent decades and at the present time. Sediment profiles were collected at ten sampling points. The concentrations of 63 elements in bulk sediment were obtained using ICP-MS, and the concentrations of selected elements were evaluated by statistical factor analyses. We also calculated metal-enrichment factors and geoaccumulation indices and constructed spatial-distribution maps. Mercury (Hg) was the heaviest pollutant, with concentrations exceeding 4 mg/kg. Silver (Ag) was the second most important pollutant, with constantly increasing values. The average concentrations of the most toxic elements were comparable to those found in sediments of other ports throughout the world, and their toxicity ranged from threshold values [chromium (Cr), arsenic (As)] and midrange-effect values [cadmium (Cd), lead (Pb), copper (Cu), zinc (Zn), nickel (Ni)] to extreme-effect values (Hg). Metal pollution has decreased during recent decades, except for Ag and barium (Ba). Copyright © 2010 Elsevier Ltd. All rights reserved.

Electronic, optical properties and chemical bonding in six novel 1111-like chalcogenide fluorides AMChF (A=Sr, Ba; M=Cu, Ag; and Ch=S, Se, Te) from first principles calculations

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

Bannikov, V.V.; Shein, I.R.; Ivanovskii, A.L., E-mail: ivanovskii@ihim.uran.ru

2012-12-15

Employing first-principles band structure calculations, we have examined the electronic, optical properties and the peculiarities of the chemical bonding for six newly synthesized layered quaternary 1111-like chalcogenide fluorides SrAgSF, SrAgSeF, SrAgTeF, BaAgSF, BaAgSeF, and SrCuTeF, which are discussed in comparison with some isostructural 1111-like chalcogenide oxides. We found that all of the studied phases AMChF (A=Sr, Ba; M=Cu, Ag; and Ch=S, Se, Te) are semiconductors for which the fitted 'experimental' gaps lie in the interval from 2.23 eV (for SrAgSeF) to 3.07 eV (for SrCuTeF). The near-Fermi states of AMChF are formed exclusively by the valence orbitals of the atomsmore » from the blocks (MCh); thus, these phases belong to the layered materials with 'natural multiple quantum wells'. The bonding in these new AMChF phases is described as a high-anisotropic mixture of ionic and covalent contributions, where ionic M-Ch bonds together with covalent M-Ch and Ch-Ch bonds take place inside blocks (MCh), while inside blocks (AF) and between the adjacent blocks (MCh)/(AF) mainly ionic bonds emerge. - Graphical Abstract: Isoelectronic surface for SrAgSeF and atomic-resolved densities of states for SrAgTeF, and SrCuTeF. Highlights: Black-Right-Pointing-Pointer Very recently six new layered 1111-like chalcogenide fluorides AMChF were synthesized. Black-Right-Pointing-Pointer Electronic, optical properties for AMChF phases were examined from first principles. Black-Right-Pointing-Pointer All these materials are characterized as non-magnetic semiconductors. Black-Right-Pointing-Pointer Bonding is highly anisotropic and includes ionic and covalent contributions. Black-Right-Pointing-Pointer Introduction of magnetic ions in AMChF is proposed for search of novel magnetic materials.« less

The Effects of Gd-Free Impurity Phase on the Aging Behavior for the Microwave Surface Resistance of Ag-coated GdBa2Cu3O7-δ at Cryogenic Temperatures

NASA Astrophysics Data System (ADS)

Lee, Sungho; Yang, Woo Il; Jung, Ho Sang; Oh, Won-Jae; Jang, Jiyeong; Lee, Jae-Hun; Kang, Kihyeok; Moon, Seung-Hyun; Yoo, Sang-Im; Lee, Sang Young

2018-05-01

High-T C GdBa2Cu3O7-δ (GdBCO) superconductor has been popular for making superconductive tapes that have much potential for various fields of large-scale applications. We investigated aging effects on the microwave surface resistance (R S) of Ag-coated GdBCO layer on Hastelloy substrate, so called GdBCO coated conductors (CCs), and Ag-coated GdBCO films on LaAlO3 (LAO) single-crystal substrates at cryogenic temperatures and compared them with each other. Unlike the R S of Ag-coated GdBCO films showing significant degradation in 4 weeks, no significant aging effects were found in our Ag-coated GdBCO CCs aged 85 weeks. The reactive co-evaporation deposition and reaction (RCE-DR) method was used for preparing the Ag-coated GdBCO CCs. Such durability of the Ag-coated GdBCO CCs in terms of the R S could be explained by existence of a protective impurity phase, i.e., Gd-free Ba-Cu-O phase as confirmed by transmission electron microscopy study combined with the energy-dispersive X-ray spectroscopy measurements. Although the scope of this study is limited to the Ag-coated GdBCO CCs prepared by using the RCE-DR method, our results suggest that a solution for preventing the aging effects on transport properties of other kinds of Ag-coated GdBCO CCs could be realized by means of an artificially-grown protective impurity layer.

Distribution of fission products palladium, silver, cerium and cesium in the un-corroded areas of the locally corroded SiC layer of a neutron irradiated TRISO fuel particle

DOE PAGES

Wen, Haiming; van Rooyen, Isabella J.

2017-04-14

Here, detailed electron microscopy studies were performed to investigate the distribution and composition of fission products in the SiC layer of a tristructural isotropic coated particle exhibiting localized corrosion. Previous studies on this particle indicated that pure carbon areas in the SiC layer, resulting from localized corrosion of SiC by Pd, provide pathways for Ag, Cd and Cs migration. This study reveals the presence of Ag- and/or Cd-containing precipitates in un-corroded SiC areas. Ag/Cd may exist by themselves or coexist with Pd. Ag/Cd mainly transport along SiC grain boundaries. An Ag-Pd-Cd precipitate was identified at a stacking fault inside amore » SiC grain, suggesting that intragranular transport of Ag/Cd is possible. Ce is present with Pd or Pd-U in some precipitates >50 nm. U and Ce frequently coexist with each other, whereas Ag/Cd usually does not coexist with U or Ce. No Cs was detected in any precipitates in the areas examined.« less

Quantum dot sensitized solar cell based on TiO2/CdS/Ag2S heterostructure

NASA Astrophysics Data System (ADS)

Pawar, Sachin A.; Patil, Dipali S.; Kim, Jin Hyeok; Patil, Pramod S.; Shin, Jae Cheol

2017-04-01

Quantum dot sensitized solar cell (QDSSC) is fabricated based on a stepwise band structure of TiO2/CdS/Ag2S to improve the photoconversion efficiency of TiO2/CdS system by incorporating a low band gap Ag2S QDs. Vertically aligned TiO2 nanorods assembly is prepared by a simple hydrothermal technique. The formation of CdS and Ag2S QDs over TiO2 nanorods assembly as a photoanode is carried out by successive ionic layer adsorption and reaction (SILAR) technique. The synthesized electrode materials are characterized by XRD, XPS, field emission scanning electron microscopy (FE-SEM), Optical, solar cell and electrochemical performances. The results designate that the QDs of CdS and Ag2S have efficiently covered exterior surfaces of TiO2 nanorods assembly. A cautious evaluation between TiO2/CdS and TiO2/CdS/Ag2S sensitized cells tells that CdS and Ag2S synergetically helps to enhance the light harvesting ability. Under AM 1.5G illumination, the photoanodes show an improved power conversion efficiency of 1.87%, in an aqueous polysulfide electrolyte with short-circuit photocurrent density of 7.03 mA cm-2 which is four fold higher than that of a TiO2/CdS system.

CD209-336A/G promotor polymorphism and its clinical associations in sickle cell disease Egyptian Pediatric patients.

PubMed

Afifi, Rasha Abdel-Raouf; Kamal, Dina; Sayed, Riham El; Ekladious, Sherif M M; Shaheen, Gehan H; Yousry, Sherif M; Hussein, Rania Elsayed

2018-06-01

To detect the frequency of CD209 A>G polymorphism in sickle cell disease (SCD) Egyptian patients and to evaluate the use of CD209 A>G polymorphism as a genetic predictor of SCD clinical heterogeneity. A total of 100 Egyptian children with SCD and 100 Egyptian controls were tested for CD209 A>G polymorphism and were followed up prospectively between June 2012 and December 2014. Comparison of CD209 A>G polymorphism among cases and controls did not show statistically significant difference (p = .742). In addition, comparison of the allelic frequency did not show statistically significant difference (p = .738). Infections occurred more frequently among the heterozygous genotype (AG; 60.5%) and homozygous genotype (GG; 75%) patients than among the wild (AA) genotype (24.1%; p < .001). The use of hydroxyurea treatment was significantly higher among the wild (AA) genotype (47%) than the heterozygous (AG; 21%) and homozygous (GG; 5%) genotypes (p = .003). We found no significant difference between our population of Egyptian SCD cases and controls regarding CD209 A>G polymorphism. Infections occurred more frequently among the heterozygous genotype (AG) and homozygous genotype (GG) patients. Copyright © 2017. Published by Elsevier Ltd.

CdO nanorods and Cd(OH)2/Ag core/satellite nanorods: Rapid and efficient sonochemical synthesis, characterization and their magnetic properties.

PubMed

Abbas, Mohamed; Tawfik, Wael; Chen, Jiangang

2018-01-01

We have designed an efficient and direct sonochemical method for the facile synthesis of Cd(OH) 2 , CdO, and Cd(OH) 2 /Ag core/satellite nanorods. A Cd(OH) 2 nanorod was synthesized with a one-pot, environmentally-friendly aqueous sonochemical reaction, followed by calcination at 500°C to produce CdO nanorods. Thirty minutes of re-ultrasonicated CdO nanorods in the presence of the Ag precursor was sufficient for phase transformation from the cubic structure of CdO to the monoclinic crystalline structure of Cd(OH) 2 , accompanied by deposition of Ag nanodots on the surface to form Cd(OH) 2 /Ag core/satellite nanorods. X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, energy-dispersive spectroscopy, N 2 Brunauer-Emmett-Teller adsorption-desorption, and Fourier-transform infrared spectroscopy measurements confirmed the successful formation of the various phases and the unique morphology of the nanorods/satellites. We also measured the magnetic properties using a vibrating sample magnetometer at room temperature, and the produced nanorods showed weak unsaturated ferromagnetic properties with a magnetic moment values of 0.105 and 0.076emu/g for CdO and Cd(OH) 2 /Ag NRs, respectively. In conclusion, our one-pot, cost-effective, sonochemical approach holds promise for the synthesis of various oxides and core/satellite nanoparticles. Copyright © 2017 Elsevier B.V. All rights reserved.

Apoptosis of haematopoietic cells upon thymidylate synthase inhibition is independent of p53 accumulation and CD95-CD95 ligand interaction.

PubMed Central

Muñoz-Pinedo, C; Oliver, F J; López-Rivas, A

2001-01-01

Treatment of haematopoietic BA/F3 cells with the thymidylate synthase inhibitor 5-fluoro-2'-deoxyuridine (FUdR) activated apoptosis through a mechanism that required continuous protein synthesis and was inhibited by Bcl-2 over-expression. Analysis of p53 levels in cells treated with FUdR indicated a marked accumulation of this protein. Accumulation of p53 was also observed in cells over-expressing Bcl-2. In BA/F3 cells transfected with a cDNA coding for the human papilloma virus protein E6, p53 accumulation after FUdR treatment was inhibited markedly. However, apoptosis was induced in both control and E6 cells to a similar extent. The role of the CD95/CD95 ligand (CD95L) system in FUdR-induced apoptosis was also assessed. As determined by reverse transcriptase PCR, BA/F3 expressed a low constitutive level of CD95L mRNA, which decreased following FUdR treatment. Moreover, blocking CD95-CD95L interactions with antagonistic CD95 monoclonal antibody did not prevent drug-induced apoptosis. Furthermore, analysis of caspase involvement showed important differences in apoptosis induced by CD95-triggering or FUdR treatment. In summary, these results suggest that apoptosis induced by thymineless stress in haematopoietic BA/F3 cells occurs by a mechanism that does not require accumulation of p53 and which is independent of CD95-CD95L interactions. PMID:11115403

Reference levels of trace elements in hair samples from children and adolescents in Madrid, Spain.

PubMed

Llorente Ballesteros, María Teresa; Navarro Serrano, Irene; Izquierdo Álvarez, Silvia

2017-09-01

Hair samples are used as a tool to evaluate environmental exposure to contaminants and metabolic status in the individual. However, the use of human hair is controversial, mainly because of the lack of well-defined reference levels. In the case of Spain, very few biomonitoring studies have investigated these issues in infants, children or adolescents. To establish reference levels for trace elements in children and teenagers in Madrid, Spain. Inductively coupled plasma mass spectrometry (ICP-MS) was used to measure Al, As, Ag, Ba, Bi, Cd, Cr, Co, Cu, Fe, Mn, Mo, Ni, Pb, Se, Sr, Tl and Zn levels in hair samples from 648 healthy children and adolescents (253 boys and 395 girls) between April 2008 and December 2009. Median levels were as follows: Al 18.5μg/g, As 0.07μg/g, Ag 196ng/g, Ba 0.5μg/g, Bi 0.01μg/g, Cd 18.3ng/g, Cr 0.4μg/g, Co 14.5ng/g, Cu 25.7μg/g, Fe 15.5μg/g, Mn 328ng/g, Mo 0.04μg/g, Ni 0.5μg/g, Pb 0.70μg/g, Se 0.5μg/g, Sr 1.29μg/g, Tl 0.28ng/g and Zn 121μg/g. The values of trace elements here described could be considered as possible reference ranges for hair samples from children and adolescents aged 0-18 years living in the Madrid region (central Spain). These values could also be selected as a preliminary screening tool to assess exposure sources and to generate information needed to develop prevention strategies and likewise could be a complement to other diagnostic procedures. Copyright © 2016 Elsevier GmbH. All rights reserved.

Comparison of the element composition in several plant species and their substrate from a 1500000-km2 area in Northern Europe.

PubMed

Reimann, C; Koller, F; Frengstad, B; Kashulina, G; Niskavaara, H; Englmaier, P

2001-10-20

Leaves of 9 different plant species (terrestrial moss represented by: Hylocomium splendens and Pleurozium schreberi; and 7 species of vascular plants: blueberry, Vaccinium myrtillus; cowberry, Vaccinium titis-idaea; crowberry, Empetrum nigrum; birch, Betula pubescens; willow, Salix spp.; pine, Pinus sylvestris and spruce, Picea abies) have been collected from up to 9 catchments (size 14-50 km2) spread over a 1500000 km2 area in Northern Europe. Soil samples were taken of the O-horizon and of the C-horizon at each plant sample site. All samples were analysed for 38 elements (Ag, Al, As, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, S, Sb, Sc, Se, Si, Sn, Sr, Th, Tl, U, V, Y, Zn and Zr) by ICP-MS, ICP-AES or CV-AAS (for Hg-analysis) techniques. The concentrations of some elements vary significantly between different plants (e.g. Cd, V, Co, Pb, Ba and Y). Other elements show surprisingly similar levels in all plants (e.g. Rb, S, Cu, K, Ca, P and Mg). Each group of plants (moss, shrubs, deciduous and conifers) shows a common behaviour for some elements. Each plant accumulates or excludes some selected elements. Compared to the C-horizon, a number of elements (S, K, B, Ca, P and Mn) are clearly enriched in plants. Elements showing very low plant/C-horizon ratios (e.g. Zr, Th, U, Y, Fe, Li and Al) can be used as an indicator of minerogenic dust. The plant/O-horizon and O-horizon/C-horizon ratios show that some elements are accumulated in the O-horizon (e.g. Pb, Bi, As, Ag, Sb). Airborne organic material attached to the leaves can thus, result in high values of these elements without any pollution source.

Ag plasmonic nanostructures and a novel gel electrolyte in a high efficiency TiO2/CdS solar cell.

PubMed

Kumar, P Naresh; Deepa, Melepurath; Srivastava, Avanish Kumar

2015-04-21

A novel photoanode architecture with plasmonic silver (Ag) nanostructures embedded in titania (TiO2), which served as the wide band gap semiconducting support and CdS quantum dots (QDs), as light absorbers, is presented. Ag nanostructures were prepared by a polyol method and are comprised of clumps of nanorods, 15-35 nm wide, interspersed with globular nanoparticles and they were characterized by a face centered cubic lattice. Optimization of Ag nanostructures was achieved on the basis of a superior power conversion efficiency (PCE) obtained for the cell with a Ag/TiO2/CdS electrode encompassing a mixed morphology of Ag nano-rods and particles, relative to analogous cells with either Ag nanoparticles or Ag nanorods. Interfacial charge transfer kinetics was unraveled by fluorescence quenching and lifetime studies. Ag nanostructures improve the light harvesting ability of the TiO2/CdS photoanode via (a) plasmonic and scattering effects, which induce both near- and far-field enhancements which translate to higher photocurrent densities and (b) charging effects, whereby, photoexcited electron transfer from TiO2 to Ag is facilitated by Fermi level equilibration. Owing to the spectacular ability of Ag nanostructures to increase light absorption, a greatly increased PCE of 4.27% and a maximum external quantum efficiency of 55% (at 440 nm) was achieved for the cell based on Ag/TiO2/CdS, greater by 42 and 66%, respectively, compared to the TiO2/CdS based cell. In addition, the liquid S(2-) electrolyte was replaced by a S(2-) gel containing fumed silica, and the redox potential, conductivity and p-type conduction of the two were deduced to be comparable. Although the gel based cells showed diminished solar cell performances compared to their liquid counterparts, nonetheless, the Ag/TiO2/CdS electrode continued to outperform the TiO2/CdS electrode. Our studies demonstrate that Ag nanostructures effectively capture a significant chunk of the electromagnetic spectrum and aid QD solar cells in delivering high power conversion efficiencies.

Systemic immunological tolerance to ocular antigens is mediated by TRAIL-expressing CD8+ T cells.

PubMed

Griffith, Thomas S; Brincks, Erik L; Gurung, Prajwal; Kucaba, Tamara A; Ferguson, Thomas A

2011-01-15

Systemic immunological tolerance to Ag encountered in the eye restricts the formation of potentially damaging immune responses that would otherwise be initiated at other anatomical locations. We previously demonstrated that tolerance to Ag administered via the anterior chamber (AC) of the eye required Fas ligand-mediated apoptotic death of inflammatory cells that enter the eye in response to the antigenic challenge. Moreover, the systemic tolerance induced after AC injection of Ag was mediated by CD8(+) regulatory T cells. This study examined the mechanism by which these CD8(+) regulatory T cells mediate tolerance after AC injection of Ag. AC injection of Ag did not prime CD4(+) T cells and led to increased TRAIL expression by splenic CD8(+) T cells. Unlike wild-type mice, Trail(-/-) or Dr5(-/-) mice did not develop tolerance to Ag injected into the eye, even though responding lymphocytes underwent apoptosis in the AC of the eyes of these mice. CD8(+) T cells from Trail(-/-) mice that were first injected via the AC with Ag were unable to transfer tolerance to naive recipient wild-type mice, but CD8(+) T cells from AC-injected wild-type or Dr5(-/-) mice could transfer tolerance. Importantly, the transferred wild-type (Trail(+/+)) CD8(+) T cells were also able to decrease the number of infiltrating inflammatory cells into the eye; however, Trail(-/-) CD8(+) T cells were unable to limit the inflammatory cell ingress. Together, our data suggest that "helpless" CD8(+) regulatory T cells generated after AC injection of Ag enforce systemic tolerance in a TRAIL-dependent manner to inhibit inflammation in the eye.

Systemic immunological tolerance to ocular antigens is mediated by TNF-related apoptosis-inducing ligand (TRAIL)-expressing CD8+ T cells*

PubMed Central

Griffith, Thomas S.; Brincks, Erik L.; Gurung, Prajwal; Kucaba, Tamara A.; Ferguson, Thomas A.

2010-01-01

Systemic immunological tolerance to Ag encountered in the eye restricts the formation of potentially damaging immune responses that would otherwise be initiated at other anatomical locations. We previously demonstrated that tolerance to Ag administered via the anterior chamber (AC) of the eye required FasL-mediated apoptotic death of inflammatory cells that enter the eye in response to the antigenic challenge. Moreover, the systemic tolerance induced after AC injection of Ag was mediated by CD8+ regulatory T cells. The present study examined the mechanism by which these CD8+ regulatory T cells mediate tolerance after AC injection of Ag. AC injection of Ag did not prime CD4+ T cells, and led to increased TRAIL expression by splenic CD8+ T cells. Unlike wildtype mice, Trail−/− or Dr5−/− mice did not develop tolerance to Ag injected into the eye, even though responding lymphocytes underwent apoptosis in the AC of the eyes of these mice. CD8+ T cells from Trail−/− mice that were first injected AC with Ag were unable to transfer tolerance to naïve recipient wildtype mice, but CD8+ T cells from AC-injected wildtype or Dr5−/− mice could transfer tolerance. Importantly, the transferred wildtype (Trail+/+) CD8+ T cells were also able to decrease the number of infiltrating inflammatory cells into the eye; however, Trail−/− CD8+ T cells were unable to limit the inflammatory cell ingress. Together, our data suggest that “helpless” CD8+ regulatory T cells generated after AC injection of Ag enforce systemic tolerance in a TRAIL-dependent manner to inhibit inflammation in the eye. PMID:21169546

In Situ Activation of Antigen-Specific CD8+ T Cells in the Presence of Antigen in Organotypic Brain Slices1

PubMed Central

Ling, Changying; Verbny, Yakov I.; Banks, Matthew I.; Sandor, Matyas; Fabry, Zsuzsanna

2012-01-01

The activation of Ag-specific T cells locally in the CNS could potentially contribute to the development of immune-mediated brain diseases. We addressed whether Ag-specific T cells could be stimulated in the CNS in the absence of peripheral lymphoid tissues by analyzing Ag-specific T cell responses in organotypic brain slice cultures. Organotypic brain slice cultures were established 1 h after intracerebral OVA Ag microinjection. We showed that when OVA-specific CD8+ T cells were added to Ag-containing brain slices, these cells became activated and migrated into the brain to the sites of their specific Ags. This activation of OVA-specific T cells was abrogated by the deletion of CD11c+ cells from the brain slices of the donor mice. These data suggest that brain-resident CD11c+ cells stimulate Ag-specific naive CD8+ T cells locally in the CNS and may contribute to immune responses in the brain. PMID:18523307

Influence of source distribution and geochemical composition of aerosols on children exposure in the large polymetallic mining region of the Bolivian Altiplano.

PubMed

Goix, Sylvaine; Point, David; Oliva, Priscia; Polve, Mireille; Duprey, Jean Louis; Mazurek, Hubert; Guislain, Ludivine; Huayta, Carlos; Barbieri, Flavia L; Gardon, Jacques

2011-12-15

The Bolivian Altiplano (Highlands) region is subject to intense mining, tailing and smelting activities since centuries because of the presence of large and unique polymetallic ore deposits (Ag, Au, Cu, Pb, Sn, Sb, Zn). A large scale PM(10), PM(2.5) aerosol monitoring survey was conducted during the dry season in one of the largest mining cities of this region (Oruro, 200,000 inhabitants). Aerosol fractions, source distribution and transport were investigated for 23 elements at approximately 1 km(2) scale resolution, and compared to children exposure data obtained within the same geographical space. As, Cd, Pb, Sb, W and Zn in aerosols are present at relatively high concentrations when compared to studies from other mining regions. Arsenic exceeds the European council PM(10) guide value (6 ng/m(3)) for 90% of the samples, topping 200 ng/m(3). Ag, As, Cd, Cu, Pb and Sb are present at significantly higher levels in the district located in the vicinity of the smelter zone. At the city level, principal component analysis combined with the mapping of factor scores allowed the identification and deconvolution of four individual sources: i) a natural magmatic source (Co, Cs, Fe, K, Mn, Na, Rb and U) originating from soil dust, resuspended by the traffic activity; ii) a natural sedimentary source (Mg, Ca, Sr, Ba and Th) resulting from the suspension of evaporative salt deposits located South; iii) an anthropogenic source specifically enriched in mined elements (As, Cd, Cu, Pb, Sb and Zn) mainly in the smelting district of the city; and iv) a Ni-Cr source homogenously distributed between the different city districts. Enrichment factors for As, Cd and Sb clearly show the impact of smelting activities, particularly in the finest PM(2.5) fraction. Comparison to children's hair metal contents collected in five schools from different districts shows a direct exposure to smelting activity fingerprinted by a unique trace elements pattern (Ag, As, Cu, Pb, Sb). Copyright © 2011 Elsevier B.V. All rights reserved.

Effect of particle size and particle size distribution on physical characteristics, morphology and crystal structure of explosively compacted high-T(sub c) superconductors

NASA Technical Reports Server (NTRS)

Kotsis, I.; Enisz, M.; Oravetz, D.; Szalay, A.

1995-01-01

A superconductor, of composition Y(Ba,K,Na)2Cu3O(x)/F(y) and a composite of composition Y(Ba,K,Na)2Cu3O(x)/F(y) + Ag, with changing K, Na and F content but a constant silver content (Ag = 10 mass%) was prepared using a single heat treatment. the resulting material was ground in a corundum lined mill, separated to particle size fractions of 0-40 micron, 0-63 micron and 63-900 micron and explosively compacted, using an explosive pressure of 10(exp 4) MPa and a subsequent heat treatment. Best results were obtained with the 63-900 micron fraction of composition Y(Ba(1.95) K(0.01)Cu3O(x)F(0),(05)/Ag: porosity less than 0.01 cu cm/g and current density 2800 A/sq cm at 77K.

Transcriptome Analysis of Mycobacteria-Specific CD4+ T Cells Identified by Activation-Induced Expression of CD154.

PubMed

Kunnath-Velayudhan, Shajo; Goldberg, Michael F; Saini, Neeraj K; Johndrow, Christopher T; Ng, Tony W; Johnson, Alison J; Xu, Jiayong; Chan, John; Jacobs, William R; Porcelli, Steven A

2017-10-01

Analysis of Ag-specific CD4 + T cells in mycobacterial infections at the transcriptome level is informative but technically challenging. Although several methods exist for identifying Ag-specific T cells, including intracellular cytokine staining, cell surface cytokine-capture assays, and staining with peptide:MHC class II multimers, all of these have significant technical constraints that limit their usefulness. Measurement of activation-induced expression of CD154 has been reported to detect live Ag-specific CD4 + T cells, but this approach remains underexplored and, to our knowledge, has not previously been applied in mycobacteria-infected animals. In this article, we show that CD154 expression identifies adoptively transferred or endogenous Ag-specific CD4 + T cells induced by Mycobacterium bovis bacillus Calmette-Guérin vaccination. We confirmed that Ag-specific cytokine production was positively correlated with CD154 expression by CD4 + T cells from bacillus Calmette-Guérin-vaccinated mice and show that high-quality microarrays can be performed from RNA isolated from CD154 + cells purified by cell sorting. Analysis of microarray data demonstrated that the transcriptome of CD4 + CD154 + cells was distinct from that of CD154 - cells and showed major enrichment of transcripts encoding multiple cytokines and pathways of cellular activation. One notable finding was the identification of a previously unrecognized subset of mycobacteria-specific CD4 + T cells that is characterized by the production of IL-3. Our results support the use of CD154 expression as a practical and reliable method to isolate live Ag-specific CD4 + T cells for transcriptomic analysis and potentially for a range of other studies in infected or previously immunized hosts. Copyright © 2017 by The American Association of Immunologists, Inc.

Differential kinetics and specificity of EBV-specific CD4+ and CD8+ T cells during primary infection.

PubMed

Precopio, Melissa L; Sullivan, John L; Willard, Courtney; Somasundaran, Mohan; Luzuriaga, Katherine

2003-03-01

The generation and maintenance of virus-specific CD4(+) T cells in humans are not well understood. We used short in vitro stimulation assays followed by intracellular cytokine staining to characterize the timing, magnitude, and Ag specificity of CD4(+) T cells over the course of primary EBV infection. Lytic and latent protein-specific CD4(+) T cells were readily detected at presentation with acute infectious mononucleosis and declined rapidly thereafter. Responses to BZLF-1, BMLF-1, and Epstein-Barr nuclear Ag-3A were more commonly detected than responses to Epstein-Barr nuclear Ag-1. Concurrent analyses of BZLF-1-specific CD4(+) and CD8(+) T cells revealed differences in the expansion, specificity, and stability of CD4(+) and CD8(+) T cell-mediated responses over time. Peripheral blood EBV load directly correlated with the frequency of EBV-specific CD4(+) T cell responses at presentation and over time, suggesting that EBV-specific CD4(+) T cell responses are Ag-driven.

A Compilation of Metals and Trace Elements Extracted from Materials Relevant to Pharmaceutical Applications such as Packaging Systems and Devices.

PubMed

Jenke, Dennis; Rivera, Christine; Mortensen, Tammy; Amin, Parul; Chacko, Molly; Tran, Thang; Chum, James

2013-01-01

Nearly 100 individual test articles, representative of materials used in pharmaceutical applications such as packaging and devices, were extracted under exaggerated conditions and the levels of 32 metals and trace elements (Ag, Al, As, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ge, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, Sr, Ti, V, Zn, and Zr) were measured in the extracts. The extracting solvents included aqueous mixtures at low and high pH and an organic solvent mixture (40/60 ethanol water). The sealed vessel extractions were performed by placing an appropriate portion of the test articles and an appropriate volume of extracting solution in inert extraction vessels and exposing the extraction units (and associated extraction blanks) to defined conditions of temperature and duration. The levels of extracted target elements were measured by inductively coupled plasma atomic emission spectroscopy. The overall reporting threshold for most of the targeted elements was 0.05 μg/mL, which corresponds to 0.5 μg/g for the most commonly utilized extraction stoichiometry (1 g of material per 10 mL of extracting solvent). The targeted elements could be classified into four major groups depending on the frequency with which they were present in the over 250 extractions reported in this study. Thirteen elements (Ag, As, Be, Cd, Co, Ge, Li, Mo, Ni, Sn, Ti, V, and Zr) were not extracted in reportable quantities from any of the test articles under any of the extraction conditions. Eight additional elements (Bi, Cr, Cu, Mn, Pb, Sb, Se, and Sr) were rarely extracted from the test articles at reportable levels, and three other elements (Ba, Fe, and P) were infrequently extracted from the test articles at reportable levels. The remaining eight elements (Al, B, Ca, Mg, Na, S, Si, and Zn) were more frequently present in the extracts in reportable quantities. These general trends in accumulation behavior were compared to compiled lists of elements of concern as impurities in pharmaceutical products. Nearly 100 individual test articles, representative of materials used in pharmaceutical applications such as packaging and devices, were extracted under exaggerated conditions, and the levels of thirty-two metals and trace elements (Ag, Al, As, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ge, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, Sr, Ti, V, Zn, and Zr) were measured in the extracts. The targeted elements could be classified into four major groups depending on the frequency with which they were present in the extractions reported in this study: those elements that were not extracted in reportable quantities from any of the test articles under any of the extraction conditions, those elements that were rarely extracted from the test articles at reportable levels, those elements that were infrequently extracted from the test articles at reportable levels, and those elements that were more frequently present in the extracts in reportable quantities.

Trace elements in farmed fish (Cyprinus carpio, Ctenopharyngodon idella and Oncorhynchus mykiss) from Beijing: implication from feed.

PubMed

Jiang, Haifeng; Qin, Dongli; Mou, Zhenbo; Zhao, Jiwei; Tang, Shizhan; Wu, Song; Gao, Lei

2016-06-01

Concentrations of 30 trace elements, Li, V, Cr, Mn, Fe, Ni, Cu, Mo, Zn, Se, Sr, Co, Al, Ti, As, Cs, Sc, Te, Ba, Ga, Pb, Sn, Cd, Sb, Ag, Tm, TI, Be, Hg and U in major cultured freshwater fish species (common carp-Cyprinus carpio, grass carp-Ctenopharyngodon idella and rainbow trout-Oncorhynchus mykiss) with the corresponding feed from 23 fish farms in Beijing, China, were investigated. The results revealed that Fe, Zn, Cu, Mn, Sr, Se were the major accumulated essential elements and Al, Ti were the major accumulated non-essential elements, while Mo, Co, Ga, Sn, Cd, Sb, Ag, Tm, U, TI, Be, Te, Pb and Hg were hardly detectable. Contents of investigated trace elements were close to or much lower than those in fish from other areas in China. Correlation analysis suggested that the elemental concentrations in those fish species were relatively constant and did not vary much with the fish feed. In comparison with the limits for aquafeeds and fish established by Chinese legislation, Cd in 37.5% of rainbow trout feeds and As in 20% of rainbow trout samples exceeded the maximum limit, assuming that inorganic As accounts for 10% of total As. Further health risk assessment showed that fish consumption would not pose risks to consumers as far as non-essential element contaminants are concerned. However, the carcinogenic risk of As in rainbow trout for the inhabitants in Beijing exceeded the acceptable level of 10(-)(4), to which more attention should be paid.

Optical studies of CdSe/HgSe and CdSe/Ag2Se core/shell nanoparticles embedded in gelatin

NASA Astrophysics Data System (ADS)

Azhniuk, Yu M.; Dzhagan, V. M.; Raevskaya, A. E.; Stroyuk, A. L.; Kuchmiy, S. Ya; Valakh, M. Ya; Zahn, D. R. T.

2008-11-01

CdSe/HgSe and CdSe/Ag2Se core-shell nanoparticles are obtained by colloidal synthesis from aqueous solutions in the presence of gelatin. Optical absorption, luminescence, and Raman spectra of the nanoparticles obtained are measured. The variation of the optical spectra of CdSe/HgSe and CdSe/Ag2Se core-shell nanoparticles with the shell thickness is discussed. Sharp non-monotonous variation of the photoluminescence spectra at low shell coverage is observed.

CD4/CD8/Dendritic cell complexes in the spleen: CD8+ T cells can directly bind CD4+ T cells and modulate their response

PubMed Central

Barinov, Aleksandr; Galgano, Alessia; Krenn, Gerald; Tanchot, Corinne; Vasseur, Florence

2017-01-01

CD4+ T cell help to CD8+ T cell responses requires that CD4+ and CD8+ T cells interact with the same antigen presenting dendritic cell (Ag+DC), but it remains controversial whether helper signals are delivered indirectly through a licensed DC and/or involve direct CD4+/CD8+ T cell contacts and/or the formation of ternary complexes. We here describe the first in vivo imaging of the intact spleen, aiming to evaluate the first interactions between antigen-specific CD4+, CD8+ T cells and Ag+DCs. We show that in contrast to CD4+ T cells which form transient contacts with Ag+DC, CD8+ T cells form immediate stable contacts and activate the Ag+DC, acquire fragments of the DC membranes by trogocytosis, leading to their acquisition of some of the DC properties. They express MHC class II, and become able to present the specific Marilyn peptide to naïve Marilyn CD4+ T cells, inducing their extensive division. In vivo, these CD8+ T cells form direct stable contacts with motile naïve CD4+ T cells, recruiting them to Ag+DC binding and to the formation of ternary complexes, where CD4+ and CD8+ T cells interact with the DC and with one another. The presence of CD8+ T cells during in vivo immune responses leads to the early activation and up-regulation of multiple functions by CD4+ T lymphocytes. Thus, while CD4+ T cell help is important to CD8+ T cell responses, CD8+ T cells can interact directly with naïve CD4+ T cells impacting their recruitment and differentiation. PMID:28686740

Colorimetric detection of trivalent chromium in aqueous solution using tartrate-capped silver nanoparticles as probe.

PubMed

Xu, Yunbo; Dong, Yangjun; Jiang, Xue; Zhu, Ningning

2013-10-01

This study describes a simple and highly selective method for the colorimetric detection of trivalent chromium (Cr3+) using tartrate-capped silver nanoparticles (AgNPs) as probe. The addition of tartrate to the initially prepared AgNPs gives tartrate-stabilized AgNPs ascribing to the electrostatic repulsion of the highly negatively charged tartrate ions covered on the surface of AgNPs. It is found that, in the presence of Cr3+ in aqueous solution, the aggregation of tartrate-stabilized AgNPs occurs. The color of AgNPs suspension changes from yellow to pink and the surface plasmon absorption band broadens and red shifts, which could be applied for the colorimetric detection of Cr3+ in aqueous solution. The utilization of tartrate-stabilized AgNPs as probe substantially increases the selectivity and sensitivity for colorimetric detection of Cr3+. Control experiments with the addition of over 14 other metal ions, such as Pb2+, Zn2+, Cr2O7(2-), Cd2+, Co2+, Cu2+, Al3+, Ni2+, Mn2+, Ba2+, Fe3+, Ca2+, Mg2+, Sr+ do not result in a distinct change in the color or in the spectrum of the suspension, indicating that these metal ions do not interfere with the colorimetric detection of Cr3+. Under the conditions employed here, A502/A393 (ratio of absorption value at 502 nm to 393 nm) is linear with the concentration of Cr3+ within a concentration range from 0.1 to 1.17 microM with a detection limit of 0.06 microM. This study may offer a simple, rapid and sensitive approach to colorimetric detection of Cr3+ in aqueous solution.

The role of the seagrass Posidonia oceanica in the cycling of trace elements

NASA Astrophysics Data System (ADS)

Sanz-Lázaro, C.; Malea, P.; Apostolaki, E. T.; Kalantzi, I.; Marín, A.; Karakassis, I.

2012-03-01

The aim of this work was to study the role of the seagrass Posidonia oceanica on the cycling of a wide set of trace elements (Ag, As, Ba, Bi, Cd, Co, Cr, Cs, Cu, Fe, Ga, Li, Mn, Ni, Pb, Rb, Sr, Tl, V and Zn). We measured the concentration of these trace elements in the different compartments of P. oceanica (leaves, rhizomes, roots and epibiota) in a non-polluted seagrass meadow representative of the Mediterranean and calculated the annual budget from a mass balance. We provide novel data on accumulation dynamics of many trace elements in P. oceanica compartments and demonstrate that trace element accumulation patterns are mainly determined by plant compartment rather than by temporal variability. Epibiota was the compartment which showed the greatest concentrations for most trace elements. Thus, they constitute a key compartment when estimating trace element transfer to higher trophic levels by P. oceanica. For most trace elements, translocation seemed to be low and acropetal. Zn, Cd, Sr and Rb were the trace elements that showed the highest release rate through decomposition of plant detritus, while Cs, Tl and Bi the lowest. P. oceanica acts as a sink of potentially toxic trace elements (Ni, Cr, As and Ag), which can be sequestered, decreasing their bioavailability. P. oceanica may have a relevant role in the cycling of trace elements in the Mediterranean.

The role of the seagrass Posidonia oceanica in the cycling of trace elements

NASA Astrophysics Data System (ADS)

Sanz-Lázaro, C.; Malea, P.; Apostolaki, E. T.; Kalantzi, I.; Marín, A.; Karakassis, I.

2012-07-01

The aim of this study was to investigate the role of the seagrass Posidonia oceanica on the cycling of a wide set of trace elements (Ag, As, Ba, Bi, Cd, Co, Cr, Cs, Cu, Fe, Ga, Li, Mn, Ni, Pb, Rb, Sr, Tl, V and Zn). We measured the concentration of these trace elements in different compartments of P. oceanica (leaves, rhizomes, roots and epiphytes) in a non-polluted seagrass meadow representative of the Mediterranean and calculated the annual budget from a mass balance. We provide novel data on accumulation dynamics of many trace elements in P. oceanica compartments and demonstrate that trace element accumulation patterns are mainly determined by plant compartment rather than by temporal variability. Epiphytes were the compartment, which showed the greatest concentrations for most trace elements. Thus, they constitute a key compartment when estimating trace element transfer to higher trophic levels by P. oceanica. Trace element translocation in P. oceanica seemed to be low and acropetal in most cases. Zn, Cd, Sr and Rb were the trace elements that showed the highest release rate through decomposition of plant detritus, while Cs, Tl and Bi showed the lowest. P. oceanica acts as a sink of potentially toxic trace elements (Ni, Cr, As and Ag), which can be sequestered, decreasing their bioavailability. P. oceanica may have a relevant role in the cycling of trace elements in the Mediterranean.

Antigen sensitivity of CD22-specific chimeric TCR is modulated by target epitope distance from the cell membrane.

PubMed

James, Scott E; Greenberg, Philip D; Jensen, Michael C; Lin, Yukang; Wang, Jinjuan; Till, Brian G; Raubitschek, Andrew A; Forman, Stephen J; Press, Oliver W

2008-05-15

We have targeted CD22 as a novel tumor-associated Ag for recognition by human CTL genetically modified to express chimeric TCR (cTCR) recognizing this surface molecule. CD22-specific cTCR targeting different epitopes of the CD22 molecule promoted efficient lysis of target cells expressing high levels of CD22 with a maximum lytic potential that appeared to decrease as the distance of the target epitope from the target cell membrane increased. Targeting membrane-distal CD22 epitopes with cTCR(+) CTL revealed defects in both degranulation and lytic granule targeting. CD22-specific cTCR(+) CTL exhibited lower levels of maximum lysis and lower Ag sensitivity than CTL targeting CD20, which has a shorter extracellular domain than CD22. This diminished sensitivity was not a result of reduced avidity of Ag engagement, but instead reflected weaker signaling per triggered cTCR molecule when targeting membrane-distal epitopes of CD22. Both of these parameters were restored by targeting a ligand expressing the same epitope, but constructed as a truncated CD22 molecule to approximate the length of a TCR:peptide-MHC complex. The reduced sensitivity of CD22-specific cTCR(+) CTL for Ag-induced triggering of effector functions has potential therapeutic applications, because such cells selectively lysed B cell lymphoma lines expressing high levels of CD22, but demonstrated minimal activity against autologous normal B cells, which express lower levels of CD22. Thus, our results demonstrate that cTCR signal strength, and consequently Ag sensitivity, can be modulated by differential choice of target epitopes with respect to distance from the cell membrane, allowing discrimination between targets with disparate Ag density.

Testing Room-Temperature Ionic Liquid Solutions for Depot Repair of Aluminum Coatings

DTIC Science & Technology

2011-05-01

Ne 3 Na Mg IIIB IVB VB VIB VIIB ------ VIIIB ------ IB IIB Al Si P S Cl Ar 4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 5 Rb Sr Y Zr Nb Mo Tc...Ru Rh Pd Ag Cd In Sn Sb Te I Xe 6 Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 7 Fr Ra Ac Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np...Electroplating Bath Lid Arrangement ;:::::::::::=== Thermometer Purge gas vent Anode lead Cathode lead (Extractable from the lid) Purge feed gas

BA71ΔCD2: a New Recombinant Live Attenuated African Swine Fever Virus with Cross-Protective Capabilities.

PubMed

Monteagudo, Paula L; Lacasta, Anna; López, Elisabeth; Bosch, Laia; Collado, Javier; Pina-Pedrero, Sonia; Correa-Fiz, Florencia; Accensi, Francesc; Navas, María Jesús; Vidal, Enric; Bustos, María J; Rodríguez, Javier M; Gallei, Andreas; Nikolin, Veljko; Salas, María L; Rodríguez, Fernando

2017-11-01

African swine fever is a highly contagious viral disease of mandatory declaration to the World Organization for Animal Health (OIE). The lack of available vaccines makes its control difficult; thus, African swine fever virus (ASFV) represents a major threat to the swine industry. Inactivated vaccines do not confer solid protection against ASFV. Conversely, live attenuated viruses (LAV), either naturally isolated or obtained by genetic manipulation, have demonstrated reliable protection against homologous ASFV strains, although little or no protection has been demonstrated against heterologous viruses. Safety concerns are a major issue for the use of ASFV attenuated vaccine candidates and have hampered their implementation in the field so far. While trying to develop safer and efficient ASFV vaccines, we found that the deletion of the viral CD2v (EP402R) gene highly attenuated the virulent BA71 strain in vivo Inoculation of pigs with the deletion mutant virus BA71ΔCD2 conferred protection not only against lethal challenge with the parental BA71 but also against the heterologous E75 (both genotype I strains). The protection induced was dose dependent, and the cross-protection observed in vivo correlated with the ability of BA71ΔCD2 to induce specific CD8 + T cells capable of recognizing both BA71 and E75 viruses in vitro Interestingly, 100% of the pigs immunized with BA71ΔCD2 also survived lethal challenge with Georgia 2007/1, the genotype II strain of ASFV currently circulating in continental Europe. These results open new avenues to design ASFV cross-protective vaccines, essential to fight ASFV in areas where the virus is endemic and where multiple viruses are circulating. IMPORTANCE African swine fever virus (ASFV) remains enzootic in most countries of Sub-Saharan Africa, today representing a major threat for the development of their swine industry. The uncontrolled presence of ASFV has favored its periodic exportation to other countries, the last event being in Georgia in 2007. Since then, ASFV has spread toward neighboring countries, reaching the European Union's east border in 2014. The lack of available vaccines against ASFV makes its control difficult; so far, only live attenuated viruses have demonstrated solid protection against homologous experimental challenges, but they have failed at inducing solid cross-protective immunity against heterologous viruses. Here we describe a new LAV candidate with unique cross-protective abilities: BA71ΔCD2. Inoculation of BA71ΔCD2 protected pigs not only against experimental challenge with BA71, the virulent parental strain, but also against heterologous viruses, including Georgia 2007/1, the genotype II strain of ASFV currently circulating in Eastern Europe. Copyright © 2017 Monteagudo et al.

BA71ΔCD2: a New Recombinant Live Attenuated African Swine Fever Virus with Cross-Protective Capabilities

PubMed Central

Monteagudo, Paula L.; Lacasta, Anna; López, Elisabeth; Bosch, Laia; Collado, Javier; Pina-Pedrero, Sonia; Correa-Fiz, Florencia; Accensi, Francesc; Navas, María Jesús; Vidal, Enric; Bustos, María J.; Rodríguez, Javier M.; Gallei, Andreas; Nikolin, Veljko; Salas, María L.

2017-01-01

ABSTRACT African swine fever is a highly contagious viral disease of mandatory declaration to the World Organization for Animal Health (OIE). The lack of available vaccines makes its control difficult; thus, African swine fever virus (ASFV) represents a major threat to the swine industry. Inactivated vaccines do not confer solid protection against ASFV. Conversely, live attenuated viruses (LAV), either naturally isolated or obtained by genetic manipulation, have demonstrated reliable protection against homologous ASFV strains, although little or no protection has been demonstrated against heterologous viruses. Safety concerns are a major issue for the use of ASFV attenuated vaccine candidates and have hampered their implementation in the field so far. While trying to develop safer and efficient ASFV vaccines, we found that the deletion of the viral CD2v (EP402R) gene highly attenuated the virulent BA71 strain in vivo. Inoculation of pigs with the deletion mutant virus BA71ΔCD2 conferred protection not only against lethal challenge with the parental BA71 but also against the heterologous E75 (both genotype I strains). The protection induced was dose dependent, and the cross-protection observed in vivo correlated with the ability of BA71ΔCD2 to induce specific CD8+ T cells capable of recognizing both BA71 and E75 viruses in vitro. Interestingly, 100% of the pigs immunized with BA71ΔCD2 also survived lethal challenge with Georgia 2007/1, the genotype II strain of ASFV currently circulating in continental Europe. These results open new avenues to design ASFV cross-protective vaccines, essential to fight ASFV in areas where the virus is endemic and where multiple viruses are circulating. IMPORTANCE African swine fever virus (ASFV) remains enzootic in most countries of Sub-Saharan Africa, today representing a major threat for the development of their swine industry. The uncontrolled presence of ASFV has favored its periodic exportation to other countries, the last event being in Georgia in 2007. Since then, ASFV has spread toward neighboring countries, reaching the European Union's east border in 2014. The lack of available vaccines against ASFV makes its control difficult; so far, only live attenuated viruses have demonstrated solid protection against homologous experimental challenges, but they have failed at inducing solid cross-protective immunity against heterologous viruses. Here we describe a new LAV candidate with unique cross-protective abilities: BA71ΔCD2. Inoculation of BA71ΔCD2 protected pigs not only against experimental challenge with BA71, the virulent parental strain, but also against heterologous viruses, including Georgia 2007/1, the genotype II strain of ASFV currently circulating in Eastern Europe. PMID:28814514

Effect of CdS Growth Time on the Optical Properties of One-Pot Preparation of CdS-Ag2S Binary Compounds

NASA Astrophysics Data System (ADS)

Karimipour, M.; Izadian, L.; Molaei, M.

2018-02-01

CdS-Ag2S binary nanoparticles were synthesized using a facile one-pot microwave irradiation method. The effect of initial nucleation of CdS quantum dots (QDs) using 3 min, 5 min, and 7 min of microwave irradiation on the optical properties of the final compound was studied. The composition and crystal structure of the compounds were verified using energy dispersive x-ray spectroscopy and x-ray diffraction. They revealed that existence of Ag and Cd elements with an atomic ratio of 0.19 crystalizes in the form of monoclinic Ag2S and hexagonal CdS. Scanning electron microscope images showed a spherical morphology of the resultant compound, and transmission electron microscope images showed the formation of fine particles of CdS-Ag2S composites with an average size of 5-7 nm and 10-14 nm for CdS and Ag2S, respectively. Photoluminescence spectroscopy revealed that the initial growth time of CdS has a crucial effect on the emission of binary compounds such that for 3 min and 5 min of irradiation of CdS solution, the binary compound obtains strong red and considerable near-IR emission (850 nm), but for longer time, it rapidly quenches. The results indicate that the strong red emission can be tuned from 600 nm up to 700 nm with prolonging nucleation time of CdS. This study also emphasized that the origin of red emission strongly depends on the size and defects created in the CdS QDs.

Solvo-thermal synthesis of a unique alkaline earth-transition Ba-Cd micro-porous coordination framework as hetero-metallic luminescent sensor for Cu2+ and real-time detection of benzaldehyde

NASA Astrophysics Data System (ADS)

Ding, Bin; Ma, Dian Xue; Zhang, Hui Min; Meng, Xin; Qiu, Rong Rong; Ren, Rong; Wu, Jie; Wu, Xiang Xia; Huo, Jian Zhong; Liu, Yuan Yuan; Shi, Xue Fang

2018-06-01

In this work a unique hetero-metallic alkaline earth-transition Ba-Cd luminescent micro-porous metal-organic framework {[BaCd(μ6-tp)1.5(μ2-Cl)(H2O) (DMF)2]·0.75H2O}n (H2tp = terephthalic acid) (1) has been prepared under solvo-thermal conditions. In 1 infinite 1D {Ba-X-Cd} (X = O, Cl) inorganic chains are linked via these full de-pronated tp2- ligands forming a unique 3D I1O2 type micro-porous coordination framework. PXRD patterns of 1 have been determined confirming pure phases of 1. Luminescence investigations suggested that 1 exhibits highly selective and sensitive sensing for trace amounts of benzaldehyde in ethanol, which provides a facile method for real-time detection of benzaldehyde. Meanwhile 1 also exhibits highly selective and sensitive sensing for Cu2+ over other cations with high quenching efficiency Ksv value 1.15 × 104 L·mol-1. As far as we know, 1 represents the first example of alkaline earth-transition hetero-metallic Ba-Cd micro-porous coordination framework as bi-functional luminescent probes for Cu2+ and benzaldehyde.

Solvo-thermal synthesis of a unique alkaline earth-transition Ba-Cd micro-porous coordination framework as hetero-metallic luminescent sensor for Cu2+ and real-time detection of benzaldehyde.

PubMed

Ding, Bin; Ma, Dian Xue; Zhang, Hui Min; Meng, Xin; Qiu, Rong Rong; Ren, Rong; Wu, Jie; Wu, Xiang Xia; Huo, Jian Zhong; Liu, Yuan Yuan; Shi, Xue Fang

2018-06-15

In this work a unique hetero-metallic alkaline earth-transition Ba-Cd luminescent micro-porous metal-organic framework {[BaCd(μ 6 -tp) 1.5 (μ 2 -Cl)(H 2 O) (DMF) 2 ]·0.75H 2 O} n (H 2 tp=terephthalic acid) (1) has been prepared under solvo-thermal conditions. In 1 infinite 1D {Ba-X-Cd} (X=O, Cl) inorganic chains are linked via these full de-pronated tp 2- ligands forming a unique 3D I 1 O 2 type micro-porous coordination framework. PXRD patterns of 1 have been determined confirming pure phases of 1. Luminescence investigations suggested that 1 exhibits highly selective and sensitive sensing for trace amounts of benzaldehyde in ethanol, which provides a facile method for real-time detection of benzaldehyde. Meanwhile 1 also exhibits highly selective and sensitive sensing for Cu 2+ over other cations with high quenching efficiency K sv value 1.15×10 4 L·mol -1 . As far as we know, 1 represents the first example of alkaline earth-transition hetero-metallic Ba-Cd micro-porous coordination framework as bi-functional luminescent probes for Cu 2+ and benzaldehyde. Copyright © 2018 Elsevier B.V. All rights reserved.

Superconductivity at different T{sub c} in CdBa{sub 2}Ca{sub 2}Cu{sub 3}O{sub y}

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

Balchev, N.; Lovchinov, V.; Gattef, E.

1995-06-01

A Cd analogue of the Tl and Hg n=3 series with nominal composition CdBa{sub 2}Ca{sub 2}Cu{sub 3}O{sub y} has been synthesized. The samples were superconducting according to magnetic susceptibility measurements. The critical temperature was 103 or 107 K depending on the preparation conditions. The EDX analysis revealed the presence of Cd-1111, Cd-1121, and Cd-2333 as minor phases. The observed diamagnetic effects were attributed to the different T{sub c} of these phases.

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

Kumar, Pragati, E-mail: pkumar.phy@gmail.com; Department of Physics and Astrophysics, University of Delhi, Delhi, 110 007; Saxena, Nupur

This work shows the influence of Ag concentration on structural properties of pulsed laser deposited nanocrystalline CdS thin film. X-ray photoelectron spectroscopy (XPS) studies confirm the dopant concentration in CdS films and atomic concentration of elements. XPS studies show that the samples are slightly sulfur deficient. GAXRD scan reveals the structural phase transformation from cubic to hexagonal phase of CdS without appearance of any phase of CdO, Ag{sub 2}O or Ag{sub 2}S suggesting the substitutional doping of Ag ions. Photoluminescence studies illustrate that emission intensity increases with increase in dopant concentration upto 5% and then decreases for higher dopant concentration.

Synthesis, characterization and evaluation of the photocatalytic performance of Ag-CdMoO{sub 4} solar light driven plasmonic photocatalyst

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

Adhikari, Rajesh; Malla, Shova; Gyawali, Gobinda

2013-09-01

Graphical abstract: - Highlights: • Ag-CdMoO{sub 4} solar light driven photocatalyst was successfully synthesized. • Photocatalyst exhibited strong absorption in the visible region. • Photocatalytic activity was significantly enhanced. • Enhanced activity was caused by the SPR effect induced by Ag nanoparticles. - Abstract: Ag-CdMoO{sub 4} plasmonic photocatalyst was synthesized in ethanol/water mixture by photo assisted co-precipitation method at room temperature. As synthesized powders were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV–Vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) surface area analyzer. Photocatalytic activity was evaluated by performing the degradation experiment over methylenemore » blue (MB) and indigo carmine (IC) as model dyes under simulated solar light irradiation. The results revealed that the Ag-CdMoO{sub 4} showed the higher photocatalytic performance as compared to CdMoO{sub 4} nanoparticles. Dispersion of Ag nanoparticles over the surface of CdMoO{sub 4} nanoparticles causes the surface plasmon resonance (SPR) and enhances the broad absorption in the entire visible region of the solar spectrum. Hence, dispersion of Ag nanoparticles over CdMoO{sub 4} nanoparticles could be the better alternative to enhance the absorption of visible light by scheelite crystal family for effective photocatalysis.« less

Loading Ag nanoparticles on Cd(II) boron imidazolate framework for photocatalysis

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

Liu, Min; State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002; Zhang, De-Xiang

2016-05-15

An amine-functionalized Cd(II) boron imidazolate framework (BIF-77) with three-dimensional open structure has been successfully synthesized, which can load Ag nanoparticles (NPs) for photocatalytic degradation of methylene blue (MB). - Graphical abstract: An amine-functionalized neutral Cd(II) boron imidazolate framework can load Ag NPs and show excellent photocatalytic degradation behavious for MB. - Highlights: • Amine-functionalization. • Neutral boron imidazolate framework. • Loading Ag nanoparticles (NPs). • Photocatalytic degradation of methylene blue.

Constitutive CD40L Expression on B Cells Prematurely Terminates Germinal Center Response and Leads to Augmented Plasma Cell Production in T Cell Areas

PubMed Central

Bolduc, Anna; Long, Eugene; Stapler, Dale; Cascalho, Marilia; Tsubata, Takeshi; Koni, Pandelakis A.; Shimoda, Michiko

2013-01-01

CD40/CD40L engagement is essential to T cell-dependent B cell proliferation and differentiation. However, the precise role of CD40 signaling through cognate T–B interaction in the generation of germinal center and memory B cells is still incompletely understood. To address this issue, a B cell-specific CD40L transgene (CD40LBTg) was introduced into mice with B cell-restricted MHC class II deficiency. Using this mouse model, we show that constitutive CD40L expression on B cells alone could not induce germinal center differentiation of MHC class II-deficient B cells after immunization with T cell-dependent Ag. Thus, some other MHC class II-dependent T cell-derived signals are essential for the generation of germinal center B cells in response to T cell-dependent Ag. In fact, CD40LBTg mice generated a complex Ag-specific IgG1 response, which was greatly enhanced in early, but reduced in late, primary response compared with control mice. We also found that the frequency of Ag-specific germinal center B cells in CD40LBTg mice was abruptly reduced 1 wk after immunization. As a result, the numbers of Ag-specific IgG1 long-lived plasma cells and memory B cells were reduced. By histology, large numbers of Ag-specific plasma cells were found in T cell areas adjacent to Ag-specific germinal centers of CD40LBTg mice, temporarily during the second week of primary response. These results indicate that CD40L expression on B cells prematurely terminated their ongoing germinal center response and produced plasma cells. Our results support the notion that CD40 signaling is an active termination signal for germinal center reaction. PMID:20505142

The effect of plant growth-promoting rhizobacteria on the phytoextraction of Cd and Zn by Brassica napus L.

PubMed

Dąbrowska, G; Hrynkiewicz, K; Trejgell, A; Baum, C

2017-07-03

The test strains Bacteroidetes bacterium (Ba), Pseudomonas fluorescens (Pf) and Variovorax sp. (Va) were selected in advance for their in vitro capability for growth promotion of rapeseed in the presence of increased concentrations of Cd, Cu, Pb and Zn in the medium. In the pot experiment, the strains were used for single Ba, Pf, Va or combined Ba + Pf, Ba + Va, Pf + Va, and Ba + Pf + Va inoculation of B. napus growing in contaminated soil from alluvial deposits. The positive effect of bacterial strains on plant growth was observed in vitro, but was not confirmed in situ in the contaminated soil, where the tested strains inhibited biomass production, rather than stimulating it. However, single inoculation with Ba significantly increased the chlorophyll content and K + concentration in the leaves. The inoculation of rapeseed with Ba and Va strains was indicated to be the most promising combination for phytoextraction of Cd and Zn from contaminated soil. Combined inoculation with Pf+Va and Pf + Ba+Va significantly decreased the concentration of heavy metals in the roots of rapeseed. We conclude that suitable combinations of PGPR can control the metal uptake of B. napus, selectively increasing either metal extraction or metal stabilization in the rhizosphere and offering promising applications in soil remediation.

Improving the efficiency of cadmium sulfide-sensitized titanium dioxide/indium tin oxide glass photoelectrodes using silver sulfide as an energy barrier layer and a light absorber

PubMed Central

2014-01-01

Cadmium sulfide (CdS) and silver sulfide (Ag2S) nanocrystals are deposited on the titanium dioxide (TiO2) nanocrystalline film on indium tin oxide (ITO) substrate to prepare CdS/Ag2S/TiO2/ITO photoelectrodes through a new method known as the molecular precursor decomposition method. The Ag2S is interposed between the TiO2 nanocrystal film and CdS nanocrystals as an energy barrier layer and a light absorber. As a consequence, the energy conversion efficiency of the CdS/Ag2S/TiO2/ITO electrodes is significantly improved. Under AM 1.5 G sunlight irradiation, the maximum efficiency achieved for the CdS(4)/Ag2S/TiO2/ITO electrode is 3.46%, corresponding to an increase of about 150% as compared to the CdS(4)/TiO2/ITO electrode without the Ag2S layer. Our experimental results show that the improved efficiency is mainly due to the formation of Ag2S layer that may increase the light absorbance and reduce the recombination of photogenerated electrons with redox ions from the electrolyte. PMID:25411566

[Immunological balance of CD8+CD28+/CD8+CD28- T lymphocytes can predict gastrointestinal hemorrhage in patients with inflammatory bowel disease].

PubMed

Dai, Shi-Xue; Gu, Hong-Xiang; Wu, Gang; Zhong, Tao; Jian, Hong-Jian; Zhan, Yong-le; Zhang, Min-Hai; Gao, Yong; Xu, Jun; Chen, Dong-Sheng; Liao, Guang-Jie; Feng, Yan-Ling; Liu, Hong-Bo; Zou, Ying; Chi, Hong-Gang

2016-12-20

To evaluate the sensitivity and specificity of CD8 + CD28 + /CD8 + CD28 - T lymphocyte balance in predicting the gastrointestinal hemorrhage (GH) in patients with inflammatory bowel disease (IBD). Forty-nine IBD patients, including 30 with ulcerous colitis (UC) and 19 with Crohn's disease (CD), were enrolled to test peripheral blood CD8 + CD28 + and CD8 + CD28 - T cells using flow cytometry. All the patients were followed up for one year. The receiver-operating characteristic (ROC) curves were used to test the efficiency of CD8 + CD28 + /CD8 + CD28 - T lymphocyte balance to predict GH. The differences in lasting time of remission (LTR) under different factors were compared using Kaplan-Meier survival analysis, and the correlation between CD8 + T lymphocytes and the factors were analyzed. The utilization rates of immunosuppressant, steroids, and biological agent (BA) were significantly higher in CD patients than in UC patients (P=0.003, 0.043 and 0.002, respectively). The frequencies of CD8 + CD28 + T cells were obviously higher in UC patients than those in CD patients (t=3.022, P=0.004). CD8 + CD28 + T cells, CD8 + CD28 - T cells, and especially CD8 + CD28 + /CD8 + CD28 - ratio (area under curve of 0.977, P=0.000; cut-off value of 1.14 [13.95%/12.24%] with a sensitivity of 93.3% and a specificity of 91.2%) showed good efficiencies in predicting GH (P<0.01). The mean and median of LTR of IBD patients who did not receive BA or surgical treatment were significantly longer (Χ 2 =9.730, P=0.002; Χ 2 =15.981, P=0.000). CD8 + CD28 + /CD8 + CD28 - ratio was significantly related to both BA (P=0.009) and surgery (P=0.038). Both decreased CD8 + CD28 + T cells and elevated CD8 + CD28 - T cells are closely correlated with GH, and their ratio can predict the occurrence of GH with a high sensitivity and specificity and is correlated with BA and surgery at the cut-off value of 1.14.

Chemical characteristics and source of size-fractionated atmospheric particle in haze episode in Beijing

NASA Astrophysics Data System (ADS)

Tan, Jihua; Duan, Jingchun; Zhen, Naijia; He, Kebin; Hao, Jiming

2016-01-01

The abundance, behavior, and source of chemical species in size-fractionated atmospheric particle were studied with a 13-stage low pressure impactor (ELPI) during high polluted winter episode in Beijing. Thirty three elements (Al, Ca, Fe, K, Mg, Na, Si, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Sr, Zr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, Hg, Tl, and Pb) and eight water soluble ions (Cl-, NO3-, SO42 -, NH4+, Na+, K+, Ca2 +, and Mg2 +) were determined by ICP/MS and IC, respectively. The size distribution of TC (OC + EC) was reconstructed. Averagely, 51.5 ± 5.3% and 74.1 ± 3.7% of the total aerosol mass was distributed in the sub-micron (PM1) and fine particle (PM2.5), respectively. A significant shift to larger fractions during heavy pollution episode was observed for aerosol mass, NH4+, SO42 -, NO3-, K, Fe, Cu, Zn, Cd, and Pb. The mass size distributions of NH4+, SO42 -, NO3-, and K were dominated by accumulation mode. Size distributions of elements were classified into four main types: (I) elements were enriched within the accumulation mode (< 1 μm, Ge, Se, Ag, Sn, Sb, Cs, Hg, Ti, and Pb); (II) those mass (K, Cr, Mn, Cu, Zn, As, Mo, and Cd) was resided mainly within the accumulation mode, ranged from 1 to 2 μm; (III) Na, V, Co, Ni, and Ga were distributed among fine, intermediate, and coarse modes; and (IV) those which were mainly found within particles larger than 2.7 μm (Al, Mg, Si, Ca, Sc, Tl, Fe, Sr, Zr, and Ba). [H+]cor showed an accumulation mode at 600-700 nm and the role of Ca2 + should be fully considered in the estimation of acidity. The acidity in accumulation mode particles suggested that generally gaseous NH3 was not enough to neutralize sulfate completely. PMF method was applied for source apportionment of elements combined with water soluble ions. Dust, vehicle, aged coal combustion, and sea salt were identified, and the size resolved source apportionments were discussed. Aged coal combustion was the important source of fine particles and dust contributed most to coarse particle.

[Characterization of structural change of ascorbate peroxidase from Chinese kale during denaturation by circular dichroism].

PubMed

Xi, Jia-Fu; Tang, Lei; Zhang, Jian-Hua; Zhang, Hong-Jian; Chen, Xu-Sheng; Mao, Zhong-Gui

2014-11-01

Circular dichroism (CD) is a special absorption spectrum. The secondary structure of protein such as α-helix, β-sheet and β-turn in the far ultraviolet region (190-250 nm) has a characteristic CD spectrum. In order to understand the activity and structural changes of ascorbate peroxidase from Chinese kale (BaAPX) during denaturation, specific activity and percentage of secondary structure of BaAPX under different time, temperature and concentration were analyzed by CD dynamically. In addition, the percentage of four secondary structures in BaAPX was calculated by CD analysis software Dichroweb. The results show that BaAPX is a full α-type enzyme whose specific activity is positively related to the percentage of α-helix. During denaturation of BaAPX, three kinds of structural changes were proposed: the one-step structural change from initial state (N state) to minimum state of α-helix (R state) under low concentration and low temperature; the one-step structural change from N state to equilibrium state (T state) under high concentration and low temperature; the two-step structural changes from N state through R state to final T state under heat treatment and low temperature renaturation.

Retrogenic ICOS Expression Increases Differentiation of KLRG-1hiCD127loCD8+ T Cells during Listeria Infection and Diminishes Recall Responses.

PubMed

Liu, Danya; Burd, Eileen M; Coopersmith, Craig M; Ford, Mandy L

2016-02-01

Following T cell encounter with Ag, multiple signals are integrated to collectively induce distinct differentiation programs within Ag-specific CD8(+) T cell populations. Several factors contribute to these cell fate decisions, including the amount and duration of Ag, exposure to inflammatory cytokines, and degree of ligation of cosignaling molecules. The ICOS is not expressed on resting T cells but is rapidly upregulated upon encounter with Ag. However, the impact of ICOS signaling on programmed differentiation is not well understood. In this study, we therefore sought to determine the role of ICOS signaling on CD8(+) T cell programmed differentiation. Through the creation of novel ICOS retrogenic Ag-specific TCR-transgenic CD8(+) T cells, we interrogated the phenotype, functionality, and recall potential of CD8(+) T cells that receive early and sustained ICOS signaling during Ag exposure. Our results reveal that these ICOS signals critically impacted cell fate decisions of Ag-specific CD8(+) T cells, resulting in increased frequencies of KLRG-1(hi)CD127(lo) cells, altered BLIMP-1, T-bet, and eomesodermin expression, and increased cytolytic capacity as compared with empty vector controls. Interestingly, however, ICOS retrogenic CD8(+) T cells also preferentially homed to nonlymphoid organs and exhibited reduced multicytokine functionality and reduced ability to mount secondary recall responses upon challenge in vivo. In sum, our results suggest that an altered differentiation program is induced following early and sustained ICOS expression, resulting in the generation of more cytolyticly potent, terminally differentiated effectors that possess limited capacity for recall response. Copyright © 2016 by The American Association of Immunologists, Inc.

CD4 Cell Count Threshold for Cryptococcal Antigen Screening of HIV-Infected Individuals: A Systematic Review and Meta-analysis.

PubMed

Ford, Nathan; Shubber, Zara; Jarvis, Joseph N; Chiller, Tom; Greene, Greg; Migone, Chantal; Vitoria, Marco; Doherty, Meg; Meintjes, Graeme

2018-03-04

Current guidelines recommend screening all people living with human immunodeficiency virus (PLHIV) who have a CD4 count ≤100 cells/µL for cryptococcal antigen (CrAg) to identify those patients who could benefit from preemptive fluconazole treatment prior to the onset of meningitis. We conducted a systematic review to assess the prevalence of CrAg positivity at different CD4 cell counts. We searched 4 databases and abstracts from 3 conferences up to 1 September 2017 for studies reporting prevalence of CrAg positivity according to CD4 cell count strata. Prevalence estimates were pooled using random effects models. Sixty studies met our inclusion criteria. The pooled prevalence of cryptococcal antigenemia was 6.5% (95% confidence interval [CI], 5.7%-7.3%; 54 studies) among patients with CD4 count ≤100 cells/µL and 2.0% (95% CI, 1.2%-2.7%; 21 studies) among patients with CD4 count 101-200 cells/µL. Twenty-one studies provided sufficient information to compare CrAg prevalence per strata; overall, 18.6% (95% CI, 15.4%-22.2%) of the CrAg-positive cases identified at ≤200 cells/µL (n = 11823) were identified among individuals with a CD4 count 101-200 cells/µL. CrAg prevalence was higher among inpatients (9.8% [95% CI, 4.0%-15.5%]) compared with outpatients (6.3% [95% CI, 5.3%-7.4%]). The findings of this review support current recommendations to screen all PLHIV who have a CD4 count ≤100 cells/µL for CrAg and suggest that screening may be considered at CD4 cell count ≤200 cells/µL.

Associations of semen quality with non-essential heavy metals in blood and seminal fluid: data from the Environment and Male Infertility (EMI) study in Lebanon.

PubMed

Sukhn, Carol; Awwad, Johnny; Ghantous, Akram; Zaatari, Ghazi

2018-06-21

Human exposure to environmental pollutants is widespread. It was suggested that exposure to non-essential heavy metals may adversely affect semen development in men. To evaluate associations between non-essential heavy metals in blood and seminal fluid and semen quality parameters in men. Male partners of heterosexual couples were included. The following elements were measured in blood and seminal fluid: lead (Pb), cadmium (Cd), arsenic (As), barium (Ba), mercury (Hg), and uranium (U) using ion-coupled plasma-mass spectrometry. The fertility clinic at the American University of Beirut Medical Center. Semen quality parameters (volume, concentration, total count, progressive motility, viability, and normal morphology). We found that participants with low-quality semen had significantly higher Cd and Ba concentrations in the seminal fluid than participants with normal-quality semen. We also observed significant associations between low sperm viability and higher blood Cd and Ba, as well as higher seminal Pb, Cd, Ba, and U. Furthermore, U concentrations in the seminal fluid were associated with increased odds ratios for below-reference progressive sperm motility and normal morphology. Environmental exposures to Pb, Cd, Ba, and U appear to adversely influence sperm development in men. In non-occupationally exposed men, measurements of heavy metals in the seminal fluid may be more predictive of below-reference sperm quality parameters than in blood.

Patterns of metal composition and biological condition and their association in male common carp across an environmental contaminant gradient in Lake Mead National Recreation Area, Nevada and Arizona, USA

USGS Publications Warehouse

Patino, R.; Rosen, Michael R.; Orsak, E.L.; Goodbred, S.L.; May, T.W.; Alvarez, David; Echols, K.R.; Wieser, C.M.; Ruessler, S.; Torres, L.

2012-01-01

There is a contaminant gradient in Lake Mead National Recreation Area (LMNRA) that is partly driven by municipal and industrial runoff and wastewater inputs via Las Vegas Wash (LVW). Adult male common carp (Cyprinus carpio; 10 fish/site) were collected from LVW, Las Vegas Bay (receiving LVW flow), Overton Arm (OA, upstream reference), and Willow Beach (WB, downstream) in March 2008. Discriminant function analysis was used to describe differences in metal concentrations and biological condition of fish collected from the four study sites, and canonical correlation analysis was used to evaluate the association between metal and biological traits. Metal concentrations were determined in whole-body extracts. Of 63 metals screened, those initially used in the statistical analysis were Ag, As, Ba, Cd, Co, Fe, Hg, Pb, Se, Zn. Biological variables analyzed included total length (TL), Fulton's condition factor, gonadosomatic index (GSI), hematocrit (Hct), and plasma estradiol-17?? and 11-ketotestosterone (11kt) concentrations. Analysis of metal composition and biological condition both yielded strong discrimination of fish by site (respective canonical model, p< 0.0001). Compared to OA, pairwise Mahalanobis distances between group means were WB < LVB < LVW for metal concentrations and LVB < WB < LVW for biological traits. Respective primary drivers for these separations were Ag, As, Ba, Hg, Pb, Se and Zn; and TL, GSI, 11kt, and Hct. Canonical correlation analysis using the latter variable sets showed they are significantly associated (p<0.0003); with As, Ba, Hg, and Zn, and TL, 11kt, and Hct being the primary contributors to the association. In conclusion, male carp collected along a contaminant gradient in LMNRA have distinct, collection site-dependent metal and morpho-physiological profiles that are significantly associated with each other. These associations suggest that fish health and reproductive condition (as measured by the biological variables evaluated in this study) are influenced by levels of certain metals in the Lake Mead environment. ?? 2011.

SERS-Based Flavonoid Detection Using Ethylenediamine-β-Cyclodextrin as a Capturing Ligand

PubMed Central

Choi, Jae Min; Hahm, Eunil; Park, Kyeonghui; Jeong, Daham; Rho, Won-Yeop; Kim, Jaehi; Jeong, Dae Hong; Lee, Yoon-Sik; Jhang, Sung Ho; Chung, Hyun Jong; Cho, Eunae; Yu, Jae-Hyuk; Jun, Bong-Hyun; Jung, Seunho

2017-01-01

Ethylenediamine-modified β-cyclodextrin (Et-β-CD) was immobilized on aggregated silver nanoparticle (NP)-embedded silica NPs (SiO2@Ag@Et-β-CD NPs) for the effective detection of flavonoids. Silica NPs were used as the template for embedding silver NPs to create hot spots and enhance surface-enhanced Raman scattering (SERS) signals. Et-β-CD was immobilized on Ag NPs to capture flavonoids via host-guest inclusion complex formation, as indicated by enhanced ultraviolet absorption spectra. The resulting SiO2@Ag@Et-β-CD NPs were used as the SERS substrate for detecting flavonoids, such as hesperetin, naringenin, quercetin, and luteolin. In particular, luteolin was detected more strongly in the linear range 10−7 to 10−3 M than various organic molecules, namely ethylene glycol, β-estradiol, isopropyl alcohol, naphthalene, and toluene. In addition, the SERS signal for luteolin captured by the SiO2@Ag@Et-β-CD NPs remained even after repeated washing. These results indicated that the SiO2@Ag@Et-β-CD NPs can be used as a rapid, sensitive, and selective sensor for flavonoids. PMID:28336842

Heat shock protein 90-mediated peptide-selective presentation of cytosolic tumor antigen for direct recognition of tumors by CD4(+) T cells.

PubMed

Tsuji, Takemasa; Matsuzaki, Junko; Caballero, Otavia L; Jungbluth, Achim A; Ritter, Gerd; Odunsi, Kunle; Old, Lloyd J; Gnjatic, Sacha

2012-04-15

Tumor Ag-specific CD4(+) T cells play important functions in tumor immunosurveillance, and in certain cases they can directly recognize HLA class II-expressing tumor cells. However, the underlying mechanism of intracellular Ag presentation to CD4(+) T cells by tumor cells has not yet been well characterized. We analyzed two naturally occurring human CD4(+) T cell lines specific for different peptides from cytosolic tumor Ag NY-ESO-1. Whereas both lines had the same HLA restriction and a similar ability to recognize exogenous NY-ESO-1 protein, only one CD4(+) T cell line recognized NY-ESO-1(+) HLA class II-expressing melanoma cells. Modulation of Ag processing in melanoma cells using specific molecular inhibitors and small interfering RNA revealed a previously undescribed peptide-selective Ag-presentation pathway by HLA class II(+) melanoma cells. The presentation required both proteasome and endosomal protease-dependent processing mechanisms, as well as cytosolic heat shock protein 90-mediated chaperoning. Such tumor-specific pathway of endogenous HLA class II Ag presentation is expected to play an important role in immunosurveillance or immunosuppression mediated by various subsets of CD4(+) T cells at the tumor local site. Furthermore, targeted activation of tumor-recognizing CD4(+) T cells by vaccination or adoptive transfer could be a suitable strategy for enhancing the efficacy of tumor immunotherapy.

[Age and gender characteristics of the content of macro- and trace elements in the organisms of the children from the European North].

PubMed

Soroko, S I; Maksimova, I A; Protasova, O V

2014-01-01

By means of the nuclear-emission spectral analysis with inductively connected argon plasma were studied the contents of 28 macro- and trace elements (Al, Ag, Li, Ba, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, In, K, Mg, Mn, Na, Ni, Mo, P, Zn, Se, Tl, Pb, Sr, S, Si) in the hair of children and teenagers living in the European North of the Russian Federation (Arkhangelsk region). There were revealed both: decrease and increase of some elements' contents. Also were revealed the dynamics of mentioned elements contents in the hair of the same children in different years. Significant individual variability of the macro and trace elements' status of children-northerners and some gender dependence were revealed.

Concentration of stable elements in food products

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

Montford, M.A.; Shank, K.E.; Hendricks, C.

1980-01-01

Food samples were taken from commercial markets and analyzed for stable element content. The concentrations of most stable elements (Ag, Al, As, Au, Ba, Br, Ca, Ce, Cl, Co, Cr, Cs, Cu, Fe, Hf, I, K, La, Mg, Mn, Mo, Na, Rb, Sb, Sc, Se, Sr, Ta, Th, Ti, V, Zn, Zr) were determined using multiple-element neutron activation analysis, while the concentrations of other elements (Cd, Hg, Ni, Pb) were determined using atomic absorption. The relevance of the concentrations found are noted in relation to other literature values. An earlier study was extended to include the determination of the concentrationmore » of stable elements in home-grown products in the vicinity of the Oak Ridge National Laboratory. Comparisons between the commercial and local food-stuff values are discussed.« less

Ternary oxide nanostructures and methods of making same

DOEpatents

Wong, Stanislaus S [Stony Brook, NY; Park, Tae-Jin [Port Jefferson, NY

2009-09-08

A single crystalline ternary nanostructure having the formula A.sub.xB.sub.yO.sub.z, wherein x ranges from 0.25 to 24, and y ranges from 1.5 to 40, and wherein A and B are independently selected from the group consisting of Ag, Al, As, Au, B, Ba, Br, Ca, Cd, Ce, Cl, Cm, Co, Cr, Cs, Cu, Dy, Er, Eu, F, Fe, Ga, Gd, Ge, Hf, Ho, I, In, Ir, K, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Nd, Ni, Os, P, Pb, Pd, Pr, Pt, Rb, Re, Rh, Ru, S, Sb, Sc, Se, Si, Sm, Sn, Sr, Ta, Tb, Tc, Te, Ti, Tl, Tm, U, V, W, Y, Yb, and Zn, wherein the nanostructure is at least 95% free of defects and/or dislocations.

AGS67E, an Anti-CD37 Monomethyl Auristatin E Antibody–Drug Conjugate as a Potential Therapeutic for B/T-Cell Malignancies and AML: A New Role for CD37 in AML

PubMed Central

Pereira, Daniel S.; Guevara, Claudia I.; Jin, Liqing; Mbong, Nathan; Verlinsky, Alla; Hsu, Ssucheng J.; Aviña, Hector; Karki, Sher; Abad, Joseph D.; Yang, Peng; Moon, Sung-Ju; Malik, Faisal; Choi, Michael Y.; An, Zili; Morrison, Kendall; Challita-Eid, Pia M.; Doñate, Fernando; Joseph, Ingrid B.J.; Kipps, Thomas J.; Dick, John E.; Stover, David R.

2015-01-01

CD37 is a tetraspanin expressed on malignant B cells. Recently, CD37 has gained interest as a therapeutic target. We developed AGS67E, an antibody–drug conjugate that targets CD37 for the potential treatment of B/T-cell malignancies. It is a fully human monoclonal IgG2 antibody (AGS67C) conjugated, via a protease-cleavable linker, to the microtubule-disrupting agent mono-methyl auristatin E (MMAE). AGS67E induces potent cytotoxicity, apoptosis, and cell-cycle alterations in many non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL) cell lines and patient-derived samples in vitro. It also shows potent antitumor activity in NHL and CLL xenografts, including Rituxan-refractory models. During profiling studies to confirm the reported expression of CD37 in normal tissues and B-cell malignancies, we made the novel discovery that the CD37 protein was expressed in T-cell lymphomas and in AML. AGS67E bound to >80% of NHL and T-cell lymphomas, 100% of CLL and 100% of AML patient-derived samples, including CD34+CD38− leukemic stem cells. It also induced cytotoxicity, apoptosis, and cell-cycle alterations in AML cell lines and antitumor efficacy in orthotopic AML xenografts. Taken together, this study shows not only that AGS67E may serve as a potential therapeutic for B/T-cell malignancies, but it also demonstrates, for the first time, that CD37 is well expressed and a potential drug target in AML. PMID:25934707

Interaction of angiogenically stimulated intermediate CD163+ monocytes/macrophages with soft hydrophobic poly(n-butyl acrylate) networks with elastic moduli matched to that of human arteries.

PubMed

Mayer, Anke; Kratz, Karl; Hiebl, Bernhard; Lendlein, Andreas; Jung, Friedrich

2012-03-01

The cell population of peripheral blood monocytes/macrophages (MO) is heterogeneous: The majority of the MO are CD14++ CD16- and named "classical" (= MO1). Furthermore, two other subpopulations were described: CD14++ CD16+ ("intermediate" = MO2) and CD14+ CD16++ ("non-classical" = MO3). It is reported that MO2 possess anti-inflammatory properties and express the MO lineage marker CD163. On a hydrophilic neutrally charged acrylamide-based hydrogel human intermediate (CD14++ CD16+ ), angiogenically stimulated CD163++ monocytes/macrophages (aMO2) maintained a proangiogenic and noninflammatory status for at least 14 days. Here, we explored whether this aMO2 subset adhered to hydrophobic poly(n-butyl acrylate) networks (cPnBA) and also remained in its proangiogenic and noninflammatory status. Because substrate elasticity can impact adherence, morphology, and function of cells, cPnBAs with different Young's modulus (250 and 1100 kPa) were investigated, whereby their elasticity was tailored by variation of the cross-linker content and matched to the elasticity of human arteries. The cPnBAs exhibited similar surface properties (e.g., surface roughness), which were maintained after ethylene oxide sterilization and exposure in serum-free cell culture medium for 18 h at 37°C. aMO2 were seeded on cPnBA samples (1.7 × 10(5) cells/1.33 cm(2) ) in Dulbecco's modified Eagle medium (DMEM high glucose) supplemented with vascular endothelial growth factor 165 (VEGF-A(165) , 10 ng/mL) and fetal calf serum (10 vol%) for 3 and 72 h. On both polymeric samples (n = 3 each), the numbers of adherent cells per unit area were significantly higher (P < 0.01; cPnBA0250: 3 h 13 ± 5 cells/mm(2) , 72 h 234 ± 106 cells/mm(2) ; cPnBA1100: 3 h 14 ± 3 cells/mm(2) , 72 h 198 ± 113 cells/mm(2) ) compared to control cultures (glass, 3 h: 6 ± 3 cells/mm(2) , 72 h: 130 ± 83 cells/mm(2) ) and showed a typically spread morphology. The mRNA expression profile of the aMO2 was not influenced by the substrate elasticity. In the supernatant of aMO2 on cPnBA0250, significantly less VEGF-A(165) product was found than expected based on the mRNA level measured (P < 0.01). Tests with recombinant VEGF-A(165) then demonstrated that significantly more VEGF-A(165) was adhered on cPnBA0250 than on cPnBA1100 (P < 0.01). Seeded on cPnBA, aMO2-unaffected by the elastic moduli of both substrates-seemed to remain in their subset status and secreted VEGF-A(165) without release of proinflammatory cytokines. These in vitro results might indicate that this MO subset can be used as cellular delivery system for proangiogenic and noninflammatory mediators to support the endothelialization of cPnBA. © 2012, Copyright the Authors. Artificial Organs © 2012, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Cutting Edge: Protection by Antiviral Memory CD8 T Cells Requires Rapidly Produced Antigen in Large Amounts.

PubMed

Remakus, Sanda; Ma, Xueying; Tang, Lingjuan; Xu, Ren-Huan; Knudson, Cory; Melo-Silva, Carolina R; Rubio, Daniel; Kuo, Yin-Ming; Andrews, Andrew; Sigal, Luis J

2018-05-15

Numerous attempts to produce antiviral vaccines by harnessing memory CD8 T cells have failed. A barrier to progress is that we do not know what makes an Ag a viable target of protective CD8 T cell memory. We found that in mice susceptible to lethal mousepox (the mouse homolog of human smallpox), a dendritic cell vaccine that induced memory CD8 T cells fully protected mice when the infecting virus produced Ag in large quantities and with rapid kinetics. Protection did not occur when the Ag was produced in low amounts, even with rapid kinetics, and protection was only partial when the Ag was produced in large quantities but with slow kinetics. Hence, the amount and timing of Ag expression appear to be key determinants of memory CD8 T cell antiviral protective immunity. These findings may have important implications for vaccine design. Copyright © 2018 by The American Association of Immunologists, Inc.

Existence of CD8α-like dendritic cells with a conserved functional specialization and a common molecular signature in distant mammalian species.

PubMed

Contreras, Vanessa; Urien, Céline; Guiton, Rachel; Alexandre, Yannick; Vu Manh, Thien-Phong; Andrieu, Thibault; Crozat, Karine; Jouneau, Luc; Bertho, Nicolas; Epardaud, Mathieu; Hope, Jayne; Savina, Ariel; Amigorena, Sebastian; Bonneau, Michel; Dalod, Marc; Schwartz-Cornil, Isabelle

2010-09-15

The mouse lymphoid organ-resident CD8alpha(+) dendritic cell (DC) subset is specialized in Ag presentation to CD8(+) T cells. Recent evidence shows that mouse nonlymphoid tissue CD103(+) DCs and human blood DC Ag 3(+) DCs share similarities with CD8alpha(+) DCs. We address here whether the organization of DC subsets is conserved across mammals in terms of gene expression signatures, phenotypic characteristics, and functional specialization, independently of the tissue of origin. We study the DC subsets that migrate from the skin in the ovine species that, like all domestic animals, belongs to the Laurasiatheria, a distinct phylogenetic clade from the supraprimates (human/mouse). We demonstrate that the minor sheep CD26(+) skin lymph DC subset shares significant transcriptomic similarities with mouse CD8alpha(+) and human blood DC Ag 3(+) DCs. This allowed the identification of a common set of phenotypic characteristics for CD8alpha-like DCs in the three mammalian species (i.e., SIRP(lo), CADM1(hi), CLEC9A(hi), CD205(hi), XCR1(hi)). Compared to CD26(-) DCs, the sheep CD26(+) DCs show 1) potent stimulation of allogeneic naive CD8(+) T cells with high selective induction of the Ifngamma and Il22 genes; 2) dominant efficacy in activating specific CD8(+) T cells against exogenous soluble Ag; and 3) selective expression of functional pathways associated with high capacity for Ag cross-presentation. Our results unravel a unifying definition of the CD8alpha(+)-like DCs across mammalian species and identify molecular candidates that could be used for the design of vaccines applying to mammals in general.

Extended Abstracts. International Symposium on Halide Glasses (2nd), Rensselaer Polytechnic Institute, Troy, New York, USA, 2-5 August 1983.

DTIC Science & Technology

1983-08-02

Research and Development in ’" T. Miyashita and i.. . nabe 34 "Environmental Effects on the Strength of Fluoride Glass Fibers" A. Nakata, J. Lau, and J...continuous optical window. Ujnfortunately YVP3 ony permit’s thin samiples (1 mm) to be synthesized. Vitrco&us domnain ina the ternary sys ~tem TIT "Zni - YbF 4...synthesis methods, quenched glasses have been obtained in the CdF2-ZnF 2-BaF2 and CdF2-MnF2-BaF 2 ternary sys - tems. Binary glasses (Cd0 .5Ba0 .5 )F2 have

CD22 Promotes B-1b Cell Responses to T Cell-Independent Type 2 Antigens.

PubMed

Haas, Karen M; Johnson, Kristen L; Phipps, James P; Do, Cardinal

2018-03-01

CD22 (Siglec-2) is a critical regulator of B cell activation and survival. CD22 -/- mice generate significantly impaired Ab responses to T cell-independent type 2 (TI-2) Ags, including haptenated Ficoll and pneumococcal polysaccharides, Ags that elicit poor T cell help and activate BCR signaling via multivalent epitope crosslinking. This has been proposed to be due to impaired marginal zone (MZ) B cell development/maintenance in CD22 -/- mice. However, mice expressing a mutant form of CD22 unable to bind sialic acid ligands generated normal TI-2 Ab responses, despite significantly reduced MZ B cells. Moreover, mice treated with CD22 ligand-binding blocking mAbs, which deplete MZ B cells, had little effect on TI-2 Ab responses. We therefore investigated the effects of CD22 deficiency on B-1b cells, an innate-like B cell population that plays a key role in TI-2 Ab responses. B-1b cells from CD22 -/- mice had impaired BCR-induced proliferation and significantly increased intracellular Ca 2+ concentration responses following BCR crosslinking. Ag-specific B-1b cell expansion and plasmablast differentiation following TI-2 Ag immunization was significantly impaired in CD22 -/- mice, consistent with reduced TI-2 Ab responses. We generated CD22 -/- mice with reduced CD19 levels (CD22 -/- CD19 +/- ) to test the hypothesis that augmented B-1b cell BCR signaling in CD22 -/- mice contributes to impaired TI-2 Ab responses. BCR-induced proliferation and intracellular Ca 2+ concentration responses were normalized in CD22 -/- CD19 +/- B-1b cells. Consistent with this, TI-2 Ag-specific B-1b cell expansion, plasmablast differentiation, survival, and Ab responses were rescued in CD22 -/- CD19 +/- mice. Thus, CD22 plays a critical role in regulating TI-2 Ab responses through regulating B-1b cell signaling thresholds. Copyright © 2018 by The American Association of Immunologists, Inc.

Mycobacterium tuberculosis PstS1 amplifies IFN-γ and induces IL-17/IL-22 responses by unrelated memory CD4+ T cells via dendritic cell activation.

PubMed

Palma, Carla; Schiavoni, Giovanna; Abalsamo, Laura; Mattei, Fabrizio; Piccaro, Giovanni; Sanchez, Massimo; Fernandez, Carmen; Singh, Mahavir; Gabriele, Lucia

2013-09-01

The immunological mechanisms that modulate protection during Mycobacterium tuberculosis (Mtb) infection or vaccination are not fully understood. Secretion of IFN-γ and, to a lesser extent, of IL-17 by CD4(+) T cells plays a major role both in protection and immunopathology. Few Mtb Ags interacting with DCs affect priming, activation, and regulation of Ag-unrelated CD4(+) T-cell responses. Here we demonstrate that PstS1, a 38 kDa-lipoprotein of Mtb, promotes Ag-independent activation of memory T lymphocytes specific for Ag85B or Ag85A, two immunodominant protective Ags of Mtb. PstS1 expands CD4(+) and CD8(+) memory T cells, amplifies secretion of IFN-γ and IL-22 and induces IL-17 production by effector memory cells in an Ag-unrelated manner in vitro and in vivo. These effects were mediated through the stimulation of DCs, particularly of the CD8α(-) subtype, which respond to PstS1 by undergoing phenotypic maturation and by secreting IL-6, IL-1β and, to a lower extent, IL-23. IL-6 secretion by PstS1-stimulated DCs was required for IFN-γ, and to a lesser extent for IL-22 responses by Ag85B-specific memory T cells. These results may open new perspectives for immunotherapeutic strategies to control Th1/Th17 immune responses in Mtb infections and in vaccinations against tuberculosis. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of the anastomosis grouping and virulence of Rhizoctonia spp. associated with potato tubers grown in Lincoln, New Zealand.

PubMed

Farrokhi-Nejad, Reza; Cromey, Matthew G; Moosawi-Jorf, S Ali

2007-11-01

A total of 58 isolates of Rhizoctonia spp. (46 R. solani and 12 binucleate Rhizoctonia) were recovered from potato tubers showing black scurf disease symptom during the 2004 growing season in Lincoln, New Zealand. The isolates were assigned to 5 Anastomosis Groups (AG) ofR. solani AG-3 (54.34%), AG-5 (28.26%), AG-8 (8.69%), AG-4 (6.52%) and AG-2-2 IIIB (2.17%) and six anastomosis groups ofbinucleate Rhizoctonia, AG-K (25%), AG-Bi (25%), AG-Ba (8.33%), AG-C (8.33%), AG-D (8.33%) and AG-E (8.33%). Two isolates of BNR did not anastomose with any of the tester strains and remain unidentified. In pathogenicity tests that were carried out on radish, carrot, lettuce, onion, tomato and hemp, it was found that all the isolates of both R. solani and binucleate Rhizoctonia to be virulent at varying degrees to these 6 plants species from different families. In these tests, isolates of AG-3 and AG-8 from R. solani population caused the highest and lowest disease severity on all 6 plant species, respectively. In population of binucleate Rhizoctonia, on the other hand, the highest and lowest disease severities were caused by the isolates of AG-D and AG-Ba on all test plants, respectively. When the results of the pathogenicity tests were examined in terms of the susceptibility levels of the plants, the most resistant plant was tomato against different AGs of R. solani and BNR. On the other hand, radish was the most susceptible plant species tested in this study against both R. solani and BNR isolates.

Identification of a candidate CD5 homologue in the amphibian Xenopus laevis.

PubMed

Jürgens, J B; Gartland, L A; Du Pasquier, L; Horton, J D; Göbel, T W; Cooper, M D

1995-11-01

We identified a novel T cell Ag in the South African clawed toad (Xenopus laevis) by a mAb designated 2B1. This Ag is present in relatively high levels on most thymocytes, approximately 65% of splenocytes, 55% of PBL, and 65% of intestinal lymphocytes, but is rarely seen on IgM+ B cells in any of these tissues. Lymphocytes bearing the 2B1 Ag proliferate in response to stimulation with Con A or PHA, whereas the 2B1- lymphocytes are reactive to LPS. Biochemical analysis indicates that this Ag is a differentially phosphorylated glycoprotein of 71 to 82 kDa. The protein core of 64 kDa bears both N- and O-linked carbohydrate side chains. The amino-terminal protein sequence of the 2B1 Ag shares significant homology with both the macrophage scavenger receptor type 1 motif and the mammalian CD5/CD6 family. The biochemical characteristics and cellular distribution of the 2B1 Ag suggest that it represents the CD5 homologue in X. laevis. While T cells constitutively express this highly conserved molecule, Xenopus B cells acquire the CD5 homologue only when they are stimulated in the presence of T cells.

CD4 Cell Count Threshold for Cryptococcal Antigen Screening of HIV-Infected Individuals: A Systematic Review and Meta-analysis

PubMed Central

Ford, Nathan; Shubber, Zara; Jarvis, Joseph N; Chiller, Tom; Greene, Greg; Migone, Chantal; Vitoria, Marco; Doherty, Meg; Meintjes, Graeme

2018-01-01

Abstract Background Current guidelines recommend screening all people living with human immunodeficiency virus (PLHIV) who have a CD4 count ≤100 cells/µL for cryptococcal antigen (CrAg) to identify those patients who could benefit from preemptive fluconazole treatment prior to the onset of meningitis. We conducted a systematic review to assess the prevalence of CrAg positivity at different CD4 cell counts. Methods We searched 4 databases and abstracts from 3 conferences up to 1 September 2017 for studies reporting prevalence of CrAg positivity according to CD4 cell count strata. Prevalence estimates were pooled using random effects models. Results Sixty studies met our inclusion criteria. The pooled prevalence of cryptococcal antigenemia was 6.5% (95% confidence interval [CI], 5.7%–7.3%; 54 studies) among patients with CD4 count ≤100 cells/µL and 2.0% (95% CI, 1.2%–2.7%; 21 studies) among patients with CD4 count 101–200 cells/µL. Twenty-one studies provided sufficient information to compare CrAg prevalence per strata; overall, 18.6% (95% CI, 15.4%–22.2%) of the CrAg-positive cases identified at ≤200 cells/µL (n = 11823) were identified among individuals with a CD4 count 101–200 cells/µL. CrAg prevalence was higher among inpatients (9.8% [95% CI, 4.0%–15.5%]) compared with outpatients (6.3% [95% CI, 5.3%–7.4%]). Conclusions The findings of this review support current recommendations to screen all PLHIV who have a CD4 count ≤100 cells/µL for CrAg and suggest that screening may be considered at CD4 cell count ≤200 cells/µL. PMID:29514236

Ionic-to-Electronic Conductivity Crossover in CdTe-AgI-As2Te3 Glasses: An 110mAg Tracer Diffusion Study.

PubMed

Kassem, M; Alekseev, I; Bokova, M; Le Coq, D; Bychkov, E

2018-04-12

Conductivity isotherms of (CdTe) x (AgI) 0.5- x/2 (As 2 Te 3 ) 0.5- x/2 glasses (0.0 ≤ x ≤ 0.15) reveal a nonmonotonic behavior with increasing CdTe content reminiscent of mixed cation effect in oxide and chalcogenide glasses. Nevertheless, the apparent similarity appears to be partly incorrect. Using 110m Ag tracer diffusion measurements, we show that semiconducting CdTe additions produce a dual effect: (i) decreasing the Ag + ion transport by a factor of ≈200 with a simultaneous increase of the diffusion activation energy and (ii) increasing the electronic conductivity by 1.5 orders of magnitude. Consequently, the conductivity minimum at x = 0.05 reflects an ionic-to-electronic transport crossover; the silver-ion transport number decreases by 3 orders of magnitude with increasing x.

Neem leaf glycoprotein promotes dual generation of central and effector memory CD8(+) T cells against sarcoma antigen vaccine to induce protective anti-tumor immunity.

PubMed

Ghosh, Sarbari; Sarkar, Madhurima; Ghosh, Tithi; Guha, Ipsita; Bhuniya, Avishek; Saha, Akata; Dasgupta, Shayani; Barik, Subhasis; Bose, Anamika; Baral, Rathindranath

2016-03-01

We have previously shown that Neem Leaf Glycoprotein (NLGP) mediates sustained tumor protection by activating host immune response. Now we report that adjuvant help from NLGP predominantly generates CD44(+)CD62L(high)CCR7(high) central memory (TCM; in lymph node) and CD44(+)CD62L(low)CCR7(low) effector memory (TEM; in spleen) CD8(+) T cells of Swiss mice after vaccination with sarcoma antigen (SarAg). Generated TCM and TEM participated either to replenish memory cell pool for sustained disease free states or in rapid tumor eradication respectively. TCM generated after SarAg+NLGP vaccination underwent significant proliferation and IL-2 secretion following SarAg re-stimulation. Furthermore, SarAg+NLGP vaccination helps in greater survival of the memory precursor effector cells at the peak of the effector response and their maintenance as mature memory cells, in comparison to single modality treatment. Such response is corroborated with the reduced phosphorylation of FOXO in the cytosol and increased KLF2 in the nucleus associated with enhanced CD62L, CCR7 expression of lymph node-resident CD8(+) T cells. However, spleen-resident CD8(+) T memory cells show superior efficacy for immediate memory-to-effector cell conversion. The data support in all aspects that SarAg+NLGP demonstrate superiority than SarAg vaccination alone that benefits the host by rapid effector functions whenever required, whereas, central-memory cells are thought to replenish the memory cell pool for ultimate sustained disease free survival till 60 days following post-vaccination tumor inoculation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Steady State Dendritic Cells Present Parenchymal Self-Antigen and Contribute to, but Are Not Essential for, Tolerization of Naive and Th1 Effector CD4 Cells1

PubMed Central

Hagymasi, Adam T.; Slaiby, Aaron M.; Mihalyo, Marianne A.; Qui, Harry Z.; Zammit, David J.; Lefrançois, Leo; Adler, Adam J.

2010-01-01

Bone marrow-derived APC are critical for both priming effector/memory T cell responses to pathogens and inducing peripheral tolerance in self-reactive T cells. In particular, dendritic cells (DC) can acquire peripheral self-Ags under steady state conditions and are thought to present them to cognate T cells in a default tolerogenic manner, whereas exposure to pathogen-associated inflammatory mediators during the acquisition of pathogen-derived Ags appears to reprogram DCs to prime effector and memory T cell function. Recent studies have confirmed the critical role of DCs in priming CD8 cell effector responses to certain pathogens, although the necessity of steady state DCs in programming T cell tolerance to peripheral self-Ags has not been directly tested. In the current study, the role of steady state DCs in programming self-reactive CD4 cell peripheral tolerance was assessed by combining the CD11c-diphtheria toxin receptor transgenic system, in which DC can be depleted via treatment with diphtheria toxin, with a TCR-transgenic adoptive transfer system in which either naive or Th1 effector CD4 cells are induced to undergo tolerization after exposure to cognate parenchymally derived self-Ag. Although steady state DCs present parenchymal self-Ag and contribute to the tolerization of cognate naive and Th1 effector CD4 cells, they are not essential, indicating the involvement of a non-DC tolerogenic APC population(s). Tolerogenic APCs, however, do not require the cooperation of CD4+CD25+ regulatory T cells. Similarly, DC were required for maximal priming of naive CD4 cells to vaccinia viral-Ag, but priming could still occur in the absence of DC. PMID:17641018

Cellular immune responses in patients with hepatitis B surface antigen seroclearance induced by antiviral therapy

PubMed Central

2011-01-01

Background The mechanisms by which chronic hepatitis B is completely resolved through antiviral therapy are unknown, and the contribution of acquired T cell immunity to hepatitis B surface antigen (HBsAg) seroclearance has not been investigated. Therefore, we measured the T-cell responses to core and envelope antigens in patients with HBsAg seroclearance. Methods Fourteen subjects with HBsAg seroclearance following antiviral treatment for chronic hepatitis B, 7 HBeAg-positive immunotolerant HBV carriers and 9 HBeAg-negative inactive HBsAg carriers were recruited. HBV-specific T-cell responses to recombinant HBV core (rHBcAg) and envelope (rHBsAg) proteins and pools of core and envelope peptides were measured using an ELISPOT assay detecting interferon-gamma and intracellular cytokine staining (ICS) assays detecting interferon-gamma or interleukin 2. Results Interferon-gamma ELISPOT assays showed a low frequency of weak responses to the rHBsAg and S peptide pool in the HBsAg seroclearance group, and the response frequency to the rHBcAg and the C peptide pool was higher than to the rHBsAg (P < 0.001) and S peptide pool (P = 0.001) respectively. A higher response frequency to C than S peptide pools was confirmed in the interferon-gamma ICS assays for both CD4+ (P = 0.033) and CD8+ (P = 0.040) T cells in the HBsAg seroclearance group. The responses to C and S antigens in the inactive carriers were similar. Conclusions There was a low frequency of CD4+ and CD8+ T cell immune responses to envelope antigens in Chinese subjects with HBsAg seroclearance following antiviral therapy. It is unlikely that these immune responses are responsible for HBsAg seroclearance in these subjects. PMID:21320337

Geosphere-biosphere circulation of chemical elements in soil and plant systems from a 100 km transect from southern central Norway.

PubMed

Reimann, Clemens; Fabian, Karl; Flem, Belinda; Andersson, Malin; Filzmoser, Peter; Englmaier, Peter

2018-05-17

Geochemical element separation is studied in 14 different sample media collected at 41 sites along an approximately 100-km long transect north of Oslo. At each site, soil C and O horizons and 12 plant materials (birch/spruce/cowberry/blueberry leaves/needles and twigs, horsetail, braken fern, pine bark and terrestrial moss) were sampled. The observed concentrations of 29 elements (K, Ca, P, Mg, Mn, S, Fe, Zn, Na, B, Cu, Mo, Co, Al, Ba, Rb, Sr, Ti, Ni, Pb, Cs, Cd, Ce, Sn, La, Tl, Y, Hg, Ag) were used to investigate soil-plant relations, and to evaluate the element differentiation between different plants, or between foliage and twigs of the same plant. In relation to the soil C horizon, the O horizon is strongly enriched (O/C ratio > 5) in Ag, Hg, Cd, Sn, S and Pb. Other elements (B, K, Ca, P, S, Mn) show higher concentrations in the plants than in the substrate represented by the C horizon, and often even higher concentrations than in the soil O horizon. Elements like B, K, Ca, S, Mg, P, Ba, and Cu are well tuned to certain concentration levels in most of the plants. This is demonstrated by their lower interquartile variability in the plants than in the soil. Cross-plots of element concentration, variance, and ratios, supported by linear discrimination analysis, establish that different plants are marked by their individual element composition, which is separable from, and largely independent of the natural substrate variability across the Gjøvik transect. Element allocation to foliage or twigs of the same plants can also be separated and thus dominantly depend on metabolism, physiology, and structure linked to biological functions, and only to a lesser degree on the substrate and environmental background. The results underline the importance of understanding the biological mechanisms of plant-soil interaction in order to correctly quantify anthropogenic impact on soil and plant geochemistry. Copyright © 2018 Elsevier B.V. All rights reserved.

Toxic elements and bio-metals in Cantharellus mushrooms from Poland and China.

PubMed

Falandysz, Jerzy; Chudzińska, Maria; Barałkiewicz, Danuta; Drewnowska, Małgorzata; Hanć, Anetta

2017-04-01

Data on multi-trace element composition and content relationships have been obtained for Cantharellus cibarius, C. tubaeformis, and C. minor mushrooms from Poland and China by inductive coupled plasma-dynamic reaction cell-mass spectroscopy. There is no previous data published on As, Li, V, Tl, and U in chanterelles from Poland and on Ba, Co, Cr, Ni, Rb, and Sr in chanterelles from China. The results implied a role of the soil background geochemistry at the collection site with the occurrence of Ag, As, Ba, Cr, Cs, Li, Mn, Pb, Rb, Sr, U, and V in the fruiting bodies. Both geogenic Cd and anthropogenic Cd can contribute in load of this element in chanterelles from the Świetokrzyskie Mts. region in Poland, while geogenic source can be highly dominant in the background areas of Yunnan. An essentiality of Cu and Zn and effort by mushroom to maintain their physiological regulation could be reflected by data for Cantharellus mushrooms from both regions of the world, but its geogenic source (and possibly anthropogenic) can matter also in the region of the Świetokrzyskie Mountains in Poland. The elements Co, Ni, and Tl were at the same order of magnitude in contents in C. cibarius in Poland and Yunnan, China. C. tubaeformis differed from C. cibarius by a lower content of correlated Co, Ni, and Zn. Soil which is polymetallic and highly weathered in Yunnan can be suggested as a natural geogenic source of greater concentrations of As, Ba, Cr, Li, Pb, Sr, U, and V in the chanterelles there while lower of Mn and Rb, when related to chanterelles in Poland. A difference in Cs content between the sites can be attributed as an effect of the 137 Cs release from the Chernobyl accident, in which Poland was much more affected than Yunnan, where deposition was negligible.

Effect of particle size and particle size distribution on physical characteristics, morphology and crystal strucutre of explosively compacted high-Tc superconductors

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

Kotsis, I.; Enisz, M.; Oravetz, D.

1994-12-31

A superconductor, of composition Y(Ba,K,Na){sub 2}Cu{sub 3}O{sub x}/F{sub y} and a composite, of composition Y(Ba,K,Na){sub 2}Cu{sub 3}O{sub x}/F{sub y}+Ag, with changing K, Na and F content, but a constant silver content (Ag=10 mass per cent) was prepared using a single heat treatment. The resulting material was ground in a corundum lined mill, separated to particle size fractions of 0-40 {mu}m, 0-63 {mu}m and 63-900 {mu}m and explosively compacted, using an explosive pressure of 10{sup 4} MPa and a subsequent heat treatment. Best results were obtained with the 63-900 {mu}m fraction of composition Y(Ba{sub 1,95}K{sub 0,01})Cu{sub 3}O{sub x}F{sub 0,05}/Ag: porosity <0.01more » cm{sup 3}/g and current density 2800 A/cm{sup 2} at 77 K.« less

Transport current density at temperatures up to 25 K of Cu/Ag composite sheathed 122-type tapes and wires

NASA Astrophysics Data System (ADS)

Liu, Shifa; Lin, Kaili; Yao, Chao; Zhang, Xianping; Dong, Chiheng; Wang, Dongliang; Awaji, Satoshi; Kumakura, Hiroaki; Ma, Yanwei

2017-11-01

The fabrication of iron-based superconductors with high transport critical current density (J c) and low cost is a crucial determinant of whether they can be used for practical applications. In this paper, Cu/Ag composite sheathed Sr0.6K0.4Fe2As2 (Sr122) tapes and Ba0.6K0.4Fe2As2 (Ba122) round wires were fabricated via an ex situ powder-in-tube method and heat-treated by the hot pressing and hot isostatic pressing process respectively. In order to thoroughly reveal the application potential of Cu/Ag composite sheathed ‘122’ iron pnictide superconductors, transport J c of tapes and wires in high fields at temperatures up to 25 K was measured. High transport J c of 4.4 × 104 A cm-2 at 4.2 K and 3.6 × 103 A cm-2 at 20 K in 10 T was achieved in Cu/Ag composite sheathed Sr122 tapes. Transport J c of Ba122 wires is 9.4 × 103 A cm-2 at 4.2 K and 1.9 × 103 A cm-2 at 20 K in 10 T. These results demonstrate the great potential of Cu/Ag composite sheathed ‘122’ iron pnictide superconducting tapes and wires for high-field applications at intermediate temperatures around 20 K, which can be easily obtained by using cryocoolers.

A Reduced Antigen Load In Vivo, Rather Than Weak Inflammation, Causes a Substantial Delay in CD8+ T Cell Priming against Mycobacterium bovis (Bacillus Calmette-Guérin)1

PubMed Central

Russell, Marsha S.; Iskandar, Monica; Mykytczuk, Oksana L.; Nash, John H. E.; Krishnan, Lakshmi; Sad, Subash

2014-01-01

Regardless of the dose of Ag, Ag presentation occurs rapidly within the first few days which results in rapid expansion of the CD8+ T cell response that peaks at day 7. However, we have previously shown that this rapid priming of CD8+ T cells is absent during infection of mice with Mycobacterium bovis (bacillus Calmette-Guérin (BCG)). In this study, we have evaluated the mechanisms responsible for the delayed CD8+ T cell priming. Because BCG replicates poorly and survives within phagosomes we considered whether 1) generation of reduced amounts of Ag or 2) weaker activation by pathogen-associated molecular patterns (PAMPs) during BCG infection is responsible for the delay in CD8+ T cell priming. Using rOVA-expressing bacteria, our results indicate that infection of mice with BCG-OVA generates greatly reduced levels of OVA, which are 70-fold lower in comparison to the levels generated during infection of mice with Listeria monocytogenes-expressing OVA. Furthermore, increasing the dose of OVA, but not PAMP signaling during BCG-OVA infection resulted in rapid Ag presentation and consequent expansion of the CD8+ T cell response, indicating that the generation of reduced Ag levels, not lack of PAMP-associated inflammation, was responsible for delayed priming of CD8+ T cells. There was a strong correlation between the relative timing of Ag presentation and the increase in the level of OVA in vivo. Taken together, these results reveal that some slowly replicating pathogens, such as mycobacteria, may facilitate their chronicity by generating reduced Ag levels which causes a substantial delay in the development of acquired immune responses. PMID:17579040

Photocatalytic activity of CdS and Ag2S quantum dots deposited on poly(amidoamine) functionalized carbon nanotubes

PubMed Central

Neelgund, Gururaj M.; Oki, Aderemi

2011-01-01

Two novel ternary nanocatalysts, f-MWCNTs-CdS and f-MWCNTs-Ag2S were successfully constructed by covalent grafting of fourth generation (G4) hyperbranched, crosslinked poly(amidoamine) (PAMAM) to carboxylated multi-walled carbon nanotubes (MWCNTs-COOH) and subsequent deposition of CdS or Ag2S quantum dots (QDs). The structural transformation, surface potential, and morphology of functionalized MWCNTs (f-MWCNTs) and nanocatalysts were characterized by UV-vis spectrophotometer, Fourier transform infrared spectroscopy, powder X-ray diffraction, Raman spectroscopy, thermogravimetric analysis, scanning electron microscopy and energy dispersive spectroscopy. Transmission electron microscopy reveals the effective anchoring of QDs on f-MWCNTs. The catalytic activity of nanocatalysts was evaluated by photodegradation of methyl orange under illumination of UV light. The coupling of MWCNTs, PAMAM and CdS or Ag2S QDs significantly enhanced the catalytic efficiency of nanocatalysts. The rate constants for degradation of methyl orange in presence of nanocatalysts were calculated using the Langmuir-Hinshelwood model. Overall, the excellence in photodegradation was accomplished by hybridizing f-MWCNTs with CdS or Ag2S PMID:22267895

Limited Model Antigen Expression by Transgenic Fungi Induces Disparate Fates during Differentiation of Adoptively Transferred T Cell Receptor Transgenic CD4+ T Cells: Robust Activation and Proliferation with Weak Effector Function during Recall

PubMed Central

Ersland, Karen; Pick-Jacobs, John C.; Gern, Benjamin H.; Frye, Christopher A.; Sullivan, Thomas D.; Brennan, Meghan B.; Filutowicz, Hanna I.; O'Brien, Kevin; Korthauer, Keegan D.; Schultz-Cherry, Stacey; Klein, Bruce S.

2012-01-01

CD4+ T cells are the key players of vaccine resistance to fungi. The generation of effective T cell-based vaccines requires an understanding of how to induce and maintain CD4+ T cells and memory. The kinetics of fungal antigen (Ag)-specific CD4+ T cell memory development has not been studied due to the lack of any known protective epitopes and clonally restricted T cell subsets with complementary T cell receptors (TCRs). Here, we investigated the expansion and function of CD4+ T cell memory after vaccination with transgenic (Tg) Blastomyces dermatitidis yeasts that display a model Ag, Eα-mCherry (Eα-mCh). We report that Tg yeast led to Eα display on Ag-presenting cells and induced robust activation, proliferation, and expansion of adoptively transferred TEa cells in an Ag-specific manner. Despite robust priming by Eα-mCh yeast, antifungal TEa cells recruited and produced cytokines weakly during a recall response to the lung. The addition of exogenous Eα-red fluorescent protein (RFP) to the Eα-mCh yeast boosted the number of cytokine-producing TEa cells that migrated to the lung. Thus, model epitope expression on yeast enables the interrogation of Ag presentation to CD4+ T cells and primes Ag-specific T cell activation, proliferation, and expansion. However, the limited availability of model Ag expressed by Tg fungi during T cell priming blunts the downstream generation of effector and memory T cells. PMID:22124658

Higher TGF-β with lower CD124 and TSLP, but no difference in PAR-2 expression in bronchial biopsy of bronchial asthma patients in comparison with COPD patients.

PubMed

Matěj, Radoslav; Vašáková, Martina; Kukal, Jaromír; Sterclová, Martina; Olejár, Tomáš

2014-08-01

Chronic obstructive pulmonary disease (COPD) and bronchial asthma (BA) are 2 severe respiratory disorders with different predominated immunopathologies. There are several "novel molecules" from different families that are proposed as part of the etiopathogenesis of COPD and BA. Proteinase-activated receptor 2 (PAR-2), thymic stromal lymphoprotein (TSLP), interleukin-4 and its receptor (CD124), Yin-Yang 1 (YY1), and transforming growth factor beta (TGF-β) have been previously shown to be involved in the pathophysiology of both these diseases. We investigated PAR-2, TSLP, CD124 (interleukin-4R), TGF-β, and YY1 immunohistochemical expression in endobronchial and transbronchial biopsies from 22 BA patients and 20 COPD patients. Immunostaining for the above-mentioned antigens was quantified using a modified semiquantitative scoring system and statistically evaluated. The values of TGF-β in the epithelial cells (P=0.0007) and TGF-β in the submucosa (P=0.0075) were higher in the BA samples, whereas values of CD124 (P=0.0015) and TSLP (P=0.0106) were higher in the COPD samples. No statistically significant differences between the groups were recorded for PAR-2 and YY1. Airway inflammatory reaction diversity in BA and COPD seems to be disease specific; however, there are also shared mechanisms involved in the pathophysiology of both diseases.

Interaction of Au, Ag, and Bi ions with Ba2YCu3O(7-y) - Implications for superconductor applications

NASA Technical Reports Server (NTRS)

Hepp, A. F.; Gaier, J. R.; Pouch, J. J.; Hambourger, P. D.

1988-01-01

Results are presented on the reactions of Au, Ag, and Bi ions with Ba2YCu3O(7-y) oxides and on the properties of the resultant materials. The results indicate that Au(3+) structural chemistry makes gold an excellent candidate for multiphase structures of the Ba2Y(Cu/1-x/Au/x/)3O(7-y)-type substituted superconductors. Silver is structurally and chemically compatible with the perovskite structure, but when it forms a second phase, it does so without the destruction of the superconducting phase, making silver a useful metal for metal/ceramic applications. On the other hand, bismuth was shown to degrade Tc phase or to form other phases, indicating that it may not be useful in applications with rare-earth-based superconductors.

Leaching of Metal Pollutants from Four Well Casings Used for Ground-Water Monitoring

DTIC Science & Technology

1989-09-01

Atomic Spectroscopy, 4:126-128. 10 APPENDIX A : LEVELS OF CD, PB, CR, BA AND CU DETERMINED IN GROUND-WATER SOLUTIONS (MG/L). Time Pqle R:ph’itc (day1s...7 Conclusion ................................................... 9 Literature cited ................................................ 9 Appendix A ... Levels of Cd, Pb, Cr, Ba and Cu determined in ground-water solutions .................................................. 11 ILLUSTRATIONS Figure 1. Ground

Photochemical Fabrication of Transition Metal Nanoparticles Using CdS Template and Their Co-Catalysis Effects for TiO2 Photocatalysis

NASA Astrophysics Data System (ADS)

Badhwar, Nidhi; Gupta, Nidhi; Pal, Bonamali

2013-09-01

Transition metal nanoparticles were prepared by chemical dissolution of CdS template from metal photodeposited CdS nanorod (length = 70-85 nm and width = 5-6 nm) heterocomposites. Size (9-10 nm) of metal nanoparticles obtained after CdS removal was larger than the size (4-6 nm) of metal nanodeposits over CdS template. The obtained Au nanoparticles displayed a broad red shifted absorption band at 660 nm, whereas Pt, Pd and Rh nanoparticles exhibit featureless absorption spectra. Elemental analysis confirms the complete removal of CdS template from Au-CdS (Au — 2.65 at.%) and Ag-CdS (Ag — 2.06 at.%) composites showing no Cd peak. These metal nanoparticles imparted dissimilar co-catalytic activity of TiO2 for photocatalytic degradation of salicylic acid in the order Au > Pt > Pd > Ag > Rh as a function of their nature, electronegativity, redox potential and work function.

Observation of New Neutron-rich Isotopes among Fission Fragments from In-flight Fission of 345 MeV/nucleon 238U: Search for New Isotopes Conducted Concurrently with Decay Measurement Campaigns

NASA Astrophysics Data System (ADS)

Shimizu, Yohei; Kubo, Toshiyuki; Fukuda, Naoki; Inabe, Naohito; Kameda, Daisuke; Sato, Hiromi; Suzuki, Hiroshi; Takeda, Hiroyuki; Yoshida, Koichi; Lorusso, Giuseppe; Watanabe, Hiroshi; Simpson, Gary S.; Jungclaus, Andrea; Baba, Hidetada; Browne, Frank; Doornenbal, Pieter; Gey, Guillaunme; Isobe, Tadaaki; Li, Zhihuan; Nishimura, Shunji; Söderström, Pär-Anders; Sumikama, Toshiyuki; Taprogge, Jan; Vajta, Zsolt; Wu, Jin; Xu, Zhengyu; Odahara, Atsuko; Yagi, Ayumi; Nishibata, Hiroki; Lozeva, Radomira; Moon, Changbum; Jung, HyoSoon

2018-01-01

The search for new isotopes using the in-flight fission of a 238U beam has been conducted concurrently with decay measurements, during the so-called EURICA campaigns, at the RIKEN Nishina Center RI Beam Factory. Fission fragments were analyzed and identified in flight using the BigRIPS separator. We have identified the following 36 new neutron-rich isotopes: 104Rb, 113Zr, 116Nb, 118,119Mo, 121,122Tc, 125Ru, 127,128Rh, 129,130,131Pd, 132Ag, 134Cd, 136,137In, 139,140Sn, 141,142Sb, 144,145Te, 146,147I, 149,150Xe, 149,150,151Cs, 153,154Ba, and 154,155,156,157La.

Effect of adherent bacteria and bacterial extracellular polymers upon assimilation by Macoma balthica of sediment-bound Cd, Zn and Ag

USGS Publications Warehouse

Harvey, Ronald W.; Luoma, Samuel N.

1985-01-01

Effects of adherent bacteria and bacterial extracellular polymer (exopolymer) upon uptake of particle-bound Cd, Zn and Ag by the deposit-feeding clam Macoma balthica were studied in the laboratory. Amorphous iron oxyhydroxide and unaltered and alkaline-extracted sediments were used as model particulates in separate, controlled deposit-feeding experiments. In general, amounts of metal taken up from ingested particles varied dramatically with the nature of the particle surface. Ingestion of contaminated iron oxide particles did not contribute to overall uptake of Cd and Ag in feeding clams, but accounted for 89 to 99% of total Zn uptake. Exopolymer adsorbed on iron oxide particles caused an increase in the biological availability of particle-bound metals in the order Ag>Cd>Zn, whereas adherent bacteria up to 3.2 X 1011 g-1 had no effect upon amounts of metal taken up from ingested particulates. At the higher Cd and Ag concentrations employed (3.6 X 10-7M), feeding rates declined with increasing amounts of iron oxide-bound exopolymer, suggesting behavioral avoidance due to increased metal availability. Much of the Cd (57 %) taken up by clams feeding on unaltered estuarine sediments originated from particulates, even though particle/solute distribution of Cd (86%) was similar to that in experiments with iron oxide particles. Uptake of Cd from alkalineextracted sediments was insignificant, as it was from unamended iron oxide. However, addition of exopolymer (10 mgg-1 sediment) caused a restoration nn bioavailability of sediment-bound Cd.

Research on mechanical properties of silver-bearing antibacterial duplex stainless steel

NASA Astrophysics Data System (ADS)

Liu, Dong; Xiang, Hongliang

2017-04-01

In this paper, silver-bearing antibacterial duplex stainless steels were prepared by adding Ag or Cu-Ag alloy particles. The microstructure, mechanical properties and fracture morphology were investigated in detail by OM, ESEM and tensile testing machine. Tensile tests indicate that the tensile fractures of Ag-bearing antibacterial duplex stainless steel and CD4MCu have the typical ductile character and toughening nests are isometric. After the solution treatment at 1050 ℃, for the material prepared by adding 150-300 µm Cu-Ag master alloy after the solution treatment at 1050 ℃, its plasticity is superior to that of CD4MCu, the strength and hardness are equivalent. But for the material prepared by adding pure Ag alloy particles, its plasticity, strength and hardness are less than that of CD4MCu. When the solution temperature rises, the plastic, strength and hardness of the material prepared by adding 150-300 µm Cu-Ag decrease.

CpG promotes cross-presentation of dead cell-associated antigens by pre-CD8α+ dendritic cells [corrected].

PubMed

de Brito, Christelle; Tomkowiak, Martine; Ghittoni, Raffaella; Caux, Christophe; Leverrier, Yann; Marvel, Jacqueline

2011-02-01

Cross-presentation of cell-associated Ags by dendritic cells (DC) plays an important role in immunity. DC in lymphoid tissues are short lived, being continuously replaced by precursors that proliferate and differentiate locally. Paradoxically, although TLR ligands promote immune responses and stimulate DC replenishment, they impair the cross-priming capacity of terminally differentiated splenic CD8α(+) DC, the major subset involved in cross-priming. In this study, we have investigated the cross-presentation capacity of newly generated murine DC and especially immediate precursors of CD8α(+) DC. We show that these DC do not cross-present Ag from dead cells unless stimulated by TLR ligands before Ag capture. TLR ligand CpG induced the expression of costimulatory molecules required for CD8 T cell activation but also regulated the intracellular mechanisms of cross-presentation such as Ag degradation rates without regulating Ag uptake. GM-CSF, an inflammatory cytokine associated with infections, also promoted cross-presentation acquisition by pre-CD8α(+) DC and synergized with TLR9 ligand. The concept that TLR ligands as well as inflammatory cytokines promote the acquisition of cross-presenting properties by pre-CD8α(+) DC has important implications during immune responses and when considering the use of these cells for vaccination.

Involvement of CD36 in Modulating the Decrease of NPY and AgRP Induced by Acute Palmitic Acid Stimulation in N1E-115 Cells.

PubMed

Ma, Yan; Wang, Xiaoyi; Yang, Hongying; Zhang, Xu; Yang, Nianhong

2017-06-17

Central nervous system (CNS) fatty acid sensing plays an important role in the regulation of food intake, and palmitic acid (PA) is the most important long chain fatty acid (LCFA) in the mammalian diet. To explore the effect of PA on central neuropeptide expression and the role of the cluster of the differentiation of 36 (CD36) in the process, N1E-115 cells were cultured with PA in the presence or absence of sulfosuccinimidyl-oleate (SSO), a CD36 inhibitor. Results showed that 10 μmol/L PA significantly reduced NPY and AgRP mRNA expression after 20 min of exposure, while the expression of CD36 was upregulated. The presence of SSO significantly attenuated the decrease of NPY and AgRP expression that was induced by PA alone, although no notable effect on PA- induced CD36 gene expression was observed. In conclusion, our study suggests the involvement of CD36 in the PA-induced decrease of NPY and AgRP in N1E-115 cells.

Involvement of CD36 in Modulating the Decrease of NPY and AgRP Induced by Acute Palmitic Acid Stimulation in N1E-115 Cells

PubMed Central

Ma, Yan; Wang, Xiaoyi; Yang, Hongying; Zhang, Xu; Yang, Nianhong

2017-01-01

Central nervous system (CNS) fatty acid sensing plays an important role in the regulation of food intake, and palmitic acid (PA) is the most important long chain fatty acid (LCFA) in the mammalian diet. To explore the effect of PA on central neuropeptide expression and the role of the cluster of the differentiation of 36 (CD36) in the process, N1E-115 cells were cultured with PA in the presence or absence of sulfosuccinimidyl-oleate (SSO), a CD36 inhibitor. Results showed that 10 μmol/L PA significantly reduced NPY and AgRP mRNA expression after 20 min of exposure, while the expression of CD36 was upregulated. The presence of SSO significantly attenuated the decrease of NPY and AgRP expression that was induced by PA alone, although no notable effect on PA- induced CD36 gene expression was observed. In conclusion, our study suggests the involvement of CD36 in the PA-induced decrease of NPY and AgRP in N1E-115 cells. PMID:28629148

Optical nonlinearity of CdSe-PMMA hybrid nanocomposite investigated via Z-scan technique and semi-empirical relations

NASA Astrophysics Data System (ADS)

Kaur, Ramneek; Tripathi, S. K.

2016-04-01

CdSe-PMMA nanocomposite has been synthesized by ex-situ technique. The effect of different Ag doping concentrations on its structural and optical properties has been studied. X-ray diffraction reveals the hexagonal wurtzite structure of the polymer nanocomposites with preferential growth of the nanocrystals along (1 0 0) direction. Transmission electron micrograph shows the spherical CdSe nanoparticles embedded in polymer matrix. The nonlinear refractive index of the nanocomposites has been calculated using Tichy & Ticha semi-empirical relations and Z-scan technique. Z-scan results disclose the two photon absorption process in the hybrid nanocomposites with self focussing behaviour. With Ag doping, the nonlinearity is found to be increased up to 0.2% Ag doping concentration due to the confined effect of Surface Plasmon, Quantum confinement and thermal lensing. Above 0.2% Ag concentration, its value decreases due to the declined linear refractive index of the nanocomposites. Maximum two photon figure of merit is 76 for 0.2% Ag doped CdSe-PMMA hybrid nanocomposite. The present results accentuate the possibility of tuning the optical non-linearity of CdSe-PMMA hybrid nanocomposite by adjusting the doping concentration.

Tissue concentrations of four Taiwanese toothed cetaceans indicating the silver and cadmium pollution in the western Pacific Ocean.

PubMed

Chen, Meng-Hsien; Zhuang, Ming-Feng; Chou, Lien-Siang; Liu, Jean-Yi; Shih, Chieh-Chih; Chen, Chiee-Young

2017-11-30

Muscle, lung, kidney and liver tissues of 45 bycatch and stranded cetaceans, including 14 Grampus griseus (Gg), 7 Kogia simus (Ks), 10 Lagenodelphis hosei (Lh), and 14 Stenella attenuata (Sa), were collected in the waters off Taiwan from 1994 to 1995, and from 2001 to 2012. Baseline concentrations (in μgg -1 dry weight) of the cetaceans were lung (<0.05)=muscle (<0.05)

Multi-elemental analysis of Lentinula edodes mushrooms available in trade.

PubMed

Mleczek, Mirosław; Siwulski, Marek; Rzymski, Piotr; Niedzielski, Przemysław; Gąsecka, Monika; Jasińska, Agnieszka; Budzyńska, Sylwia; Budka, Anna

2017-03-04

The present study investigated the content of 62 elements in the fruiting bodies of Lentinula edodes (Shiitake mushroom) cultivated commercially in Poland on various substrates from 2007-2015. The general mean content (mg kg -1 dry weight (DW)) of the studied elements ranked in the following order: K (26,335) > P (11,015) > Mg (2,284) > Ca (607) > Na (131) > Zn (112) > Fe (69) > Mn (33) > B (32) > Rb (17) > Cu (14.5) > Al (11.2) > Te (2.9) > As (1.80) > Cd (1.76) > Ag (1.73) > Nd (1.70) > Sr (1.46) > Se (1.41) > U (1.11) > Pt (0.90) > Ce (0.80) > Ba (0.61) > Co (0.59) > Tl (0.58) > Er (0.50) > Pb (0.42) > Li (0.40) > Pr (0.39) > Ir (0.37) > In (0.35) > Mo (0.31) > Cr (0.29) > Ni (0.28) > Sb (0.26) > Re (0.24) > Ti (0.19) > Bi (0.18) > Th (0.12) > La (0.10) = Pd (0.10) > Os (0.09) = Zr (0.09) > Rh (0.08) > Ho (0.07) > Ru (0.06) > Sm (0.04) = Eu (0.04) = Tm (0.04) > Gd (0.03) > Sc (0.02) = Y (0.02) > Lu (0.01) = Yb (0.01) = V (0.01). The contents of Au, Be, Dy, Ga, Ge, Hf, and Tb were below the limits of detection (0.02, 0.02, 0.01, 0.01, 0.01, 0.01, 0.02 mg kg -1 respectively). The concentrations of Al, As, B, Ba, Ca, Cd, Cr, Er, Fe, In, Lu, Mn, Nd, Sr, Ti, Tm, and Zr were comparable over the period the mushrooms were cultivated. The study revealed that Lentinula edodes contained As and Cd at levels potentially adverse to human health. This highlights the need to monitor these elements in food products obtained from this mushroom species and ensure that only low levels of these elements are present in cultivation substrates.

Mineral Composition and Nutritive Value of Isotonic and Energy Drinks.

PubMed

Leśniewicz, Anna; Grzesiak, Magdalena; Żyrnicki, Wiesław; Borkowska-Burnecka, Jolanta

2016-04-01

Several very popular brands of isotonic and energy drinks consumed for fluid and electrolyte supplementation and stimulation of mental or physical alertness were chosen for investigation. Liquid beverages available in polyethylene bottles and aluminum cans as well as products in the form of tablets and powder in sachets were studied. The total concentrations of 21 elements (Ag, Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Na, Ni, P, Pb, Sr, Ti, V, and Zn), both essential and toxic, were simultaneously determined in preconcentrated drink samples by inductively coupled plasma-optical emission spectrometry (ICP-OES) equipped with pneumatic and ultrasonic nebulizers. Differences between the mineral compositions of isotonic and energy drinks were evaluated and discussed. The highest content of Na was found in both isotonic and energy drinks, whereas quite high concentrations of Mg were found in isotonic drinks, and the highest amount of calcium was quantified in energy drinks. The concentrations of B, Co, Cu, Ni, and P were higher in isotonic drinks, but energy drinks contained greater quantities of Ag, Cr, Zn, Mn, and Mo and toxic elements, as Cd and Pb. A comparison of element contents with micronutrient intake and tolerable levels was performed to evaluate contribution of the investigated beverages to the daily diet. The consumption of 250 cm(3) of an isotonic drink provides from 0.32% (for Mn) up to 14.8% (for Na) of the recommended daily intake. For the energy drinks, the maximum recommended daily intake fulfillment ranged from 0.02% (for V) to 19.4 or 19.8% (for Mg and Na).

2B4-SAP signaling is required for the priming of naive CD8+ T cells by antigen-expressing B cells and B lymphoma cells

PubMed Central

2017-01-01

ABSTRACT Mutations in SH2D1A gene that encodes SAP (SLAM-associated protein) result in X-linked lymphoproliferative disease (XLP), a rare primary immunodeficiency disease defined by exquisite sensitivity to the B-lymphotropic Epstein–Barr virus (EBV) and B cell lymphomas. However, the precise mechanism of how the loss of SAP function contributes to extreme vulnerability to EBV and the development of B cell lymphomas remains unclear. Here, we investigate the hypothesis that SAP is critical for CD8+ T cell immune surveillance of antigen (Ag)-expressing B cells or B lymphoma cells under conditions of defined T cell receptor (TCR) signaling. Sh2d1a−/− CD8+ T cells exhibited greatly diminished proliferation relative to wild type when Ag-presenting-B cells or -B lymphoma cells served as the primary Ag-presenting cell (APC). By contrast, Sh2d1a−/− CD8+ T cells responded equivalently to wild-type CD8+ T cells when B cell-depleted splenocytes, melanoma cells or breast carcinoma cells performed Ag presentation. Through application of signaling lymphocyte activation molecule (SLAM) family receptor blocking antibodies or SLAM family receptor-deficient CD8+ T cells and APCs, we found that CD48 engagement on the B cell surface by 2B4 is crucial for initiating SAP-dependent signaling required for the Ag-driven CD8+ T cell proliferation and differentiation. Altogether, a pivotal role for SAP in promoting the expansion and differentiation of B cell-primed viral-specific naive CD8+ T cells may explain the selective immune deficiency of XLP patients to EBV and B cell lymphomas. PMID:28344876

2B4-SAP signaling is required for the priming of naive CD8+ T cells by antigen-expressing B cells and B lymphoma cells.

PubMed

Huang, Yu-Hsuan; Tsai, Kevin; Tan, Sara Y; Kang, Sohyeong; Ford, Mandy L; Harder, Kenneth W; Priatel, John J

2017-01-01

Mutations in SH2D1A gene that encodes SAP (SLAM-associated protein) result in X-linked lymphoproliferative disease (XLP), a rare primary immunodeficiency disease defined by exquisite sensitivity to the B-lymphotropic Epstein-Barr virus (EBV) and B cell lymphomas. However, the precise mechanism of how the loss of SAP function contributes to extreme vulnerability to EBV and the development of B cell lymphomas remains unclear. Here, we investigate the hypothesis that SAP is critical for CD8 + T cell immune surveillance of antigen (Ag)-expressing B cells or B lymphoma cells under conditions of defined T cell receptor (TCR) signaling. Sh2d1a - / - CD8 + T cells exhibited greatly diminished proliferation relative to wild type when Ag-presenting-B cells or -B lymphoma cells served as the primary Ag-presenting cell (APC). By contrast, Sh2d1a - / - CD8 + T cells responded equivalently to wild-type CD8 + T cells when B cell-depleted splenocytes, melanoma cells or breast carcinoma cells performed Ag presentation. Through application of signaling lymphocyte activation molecule (SLAM) family receptor blocking antibodies or SLAM family receptor-deficient CD8 + T cells and APCs, we found that CD48 engagement on the B cell surface by 2B4 is crucial for initiating SAP-dependent signaling required for the Ag-driven CD8 + T cell proliferation and differentiation. Altogether, a pivotal role for SAP in promoting the expansion and differentiation of B cell-primed viral-specific naive CD8 + T cells may explain the selective immune deficiency of XLP patients to EBV and B cell lymphomas.

Biodynamic modelling of the accumulation of Ag, Cd and Zn by the deposit-feeding polychaete Nereis diversicolor: inter-population variability and a generalised predictive model.

PubMed

Kalman, J; Smith, B D; Riba, I; Blasco, J; Rainbow, P S

2010-06-01

Biodynamic parameters of the ragworm Nereis diversicolor from southern Spain and south England were experimentally derived to assess the inter-population variability of physiological parameters of the bioaccumulation of Ag, Cd and Zn from water and sediment. Although there were some limited variations, these were not consistent with the local metal bioavailability nor with temperature changes. Incorporating the biodynamic parameters into a defined biodynamic model, confirmed that sediment is the predominant source of Cd and Zn accumulated by the worms, accounting in each case for 99% of the overall accumulated metals, whereas the contribution of dissolved Ag to the total accumulated by the worm increased from about 27 to about 53% with increasing dissolved Ag concentration. Standardised values of metal-specific parameters were chosen to generate a generalised model to be extended to N. diversicolor populations across a wide geographical range from western Europe to North Africa. According to the assumptions of this model, predicted steady state concentrations of Cd and Zn in N. diversicolor were overestimated, those of Ag underestimated, but still comparable to independent field measurements. We conclude that species-specific physiological metal bioaccumulation parameters are relatively constant over large geographical distances, and a single generalised biodynamic model does have potential to predict accumulated Ag, Cd and Zn concentrations in this polychaete from a single sediment metal concentration.

Ag nanoclusters could efficiently quench the photoresponse of CdS quantum dots for novel energy transfer-based photoelectrochemical bioanalysis.

PubMed

Zhang, Ling; Sun, Yue; Liang, Yan-Yu; He, Jian-Ping; Zhao, Wei-Wei; Xu, Jing-Juan; Chen, Hong-Yuan

2016-11-15

Herein the influence of ultrasmall Ag nanoclusters (Ag NCs) against CdS quantum dots (QDs) in a photoelectrochemical (PEC) nanosystem was exploited for the first time, based on which a novel PEC bioanalysis was successfully developed via the efficient quenching effect of Ag NCs against the CdS QDs. In a model system, DNA assay was achieved by using molecular beacon (MB) probes anchored on a CdS QDs modified electrode, and the MB probes contain two segments that can hybridize with both target DNA sequence and the label of DNA encapsulated Ag NCs. After the MB probe was unfolded by the target DNA sequence, the labels of oligonucleotide encapsulated Ag NCs would be brought in close proximity to the CdS QDs electrode surface, and efficient photocurrent quenching of QDs could be resulted from an energy transfer process that originated from NCs. Thus, by monitoring the attenuation in the photocurrent signal, an elegant and sensitive PEC DNA bioanalysis could be accomplished. The developed biosensor displayed a linear range from 1.0pM to 10nM and the detection limit was experimentally found to be of 0.3pM. This work presents a feasible signaling principle that could act as a common basis for general PEC bioanalysis development. Copyright © 2016 Elsevier B.V. All rights reserved.

Influence of reactive sulfide (AVS) and supplementary food on Ag, Cd and Zn bioaccumulation in the marine polychaete Neanthes arenaceodentata

USGS Publications Warehouse

Lee, J.-S.; Lee, B.-G.; Yoo, H.; Koh, C.-H.; Luoma, S.N.

2001-01-01

A laboratory bioassay determined the relative contribution of various pathways of Ag, Cd and Zn bioaccumulation in the marine polychaete Neanthes arenaceodentata exposed to moderately contaminated sediments. Juvenile worms were exposed for 25 d to experimental sediments containing 5 different reactive sulfide (acid volatile sulfides, AVS) concentrations (1 to 30 ??mol g-1), but with constant Ag, Cd, and Zn concentrations of 0.1, 0.1 and 7 ??mol g-1, respectively. The sediments were supplemented with contaminated food (TetraMin??) containing 3 levels of Ag-Cd-Zn (uncontaminated, 1?? or 5??1 metal concentrations in the contaminated sediment). The results suggest that bioaccumulation of Ag, Cd and Zn in the worms occurred predominantly from ingestion of contaminated sediments and contaminated supplementary food. AVS or dissolved metals (in porewater and overlying water) had a minor effect on bioaccumulation of the 3 metals in most of the treatments. The contribution to uptake from the dissolved source was most important in the most oxic sediments, with maximum contributions of 8% for Ag, 30% for Cd and 20% for Zn bioaccumulation. Sediment bioassays where uncontaminated supplemental food is added could seriously underestimate metal exposures in an equilibrated system; N. arenaceodentata feeding on uncontaminated food would be exposed to 40-60% less metal than if the food source was equilibrated (as occurs in nature). Overall, the results show that pathways of metal exposure are dynamically linked in contaminated sediments and shift as external geochemical characteristics and internal biological attributes vary.

Effects of p-chlorophenoxyisobutyric acid, arabinogalactan, and activated charcoal on microspore embryogenesis in kale.

PubMed

Niu, R Q; Zhang, Y; Tong, Y; Liu, Z Y; Wang, Y H; Feng, H

2015-04-27

To improve embryogenesis in microspore cultures of kale (Brassica oleracea L. var. acephala DC.), 6-benzylaminopurine (6-BA), naphthaleneacetic acid (NAA), arabinogalactan (AG), p-chlorophenoxyisobutyric acid (PCIB), and activated charcoal (AC) were added to the medium using four varieties of kale. The results showed that the addition of AG (0.1-0.2 g/L), AC (0.1-0.2 g/L) or a combination of 6-BA (0.1-0.2 mg/L) and NAA (0.1-0.2 mg/L) promoted embryo-genesis. Adding 40 μM PCIB or a combination of 40 μM PCIB and 0.2 g/L AC to NLN-13 medium at pH 5.8 effectively enhanced embryogenesis. Treatment with a combination of 40 μM PCIB and 10 mg/L AG gave the highest rate of embryonic induction, especially in genotype "Y007," which showed a twelve-fold increase in yield.

Antigen localization controls T cell-mediated tumor immunity.

PubMed

Zeelenberg, Ingrid S; van Maren, Wendy W C; Boissonnas, Alexandre; Van Hout-Kuijer, Maaike A; Den Brok, Martijn H M G M; Wagenaars, Jori A L; van der Schaaf, Alie; Jansen, Eric J R; Amigorena, Sebastian; Théry, Clotilde; Figdor, Carl G; Adema, Gosse J

2011-08-01

Effective antitumor immunotherapy requires the identification of suitable target Ags. Interestingly, many of the tumor Ags used in clinical trials are present in preparations of secreted tumor vesicles (exosomes). In this study, we compared T cell responses elicited by murine MCA101 fibrosarcoma tumors expressing a model Ag at different localizations within the tumor cell in association with secreted vesicles (exosomes), as a nonsecreted cell-associated protein, or as secreted soluble protein. Remarkably, we demonstrated that only the tumor-secreting vesicle-bound Ag elicited a strong Ag-specific CD8(+) T cell response, CD4(+) T cell help, Ag-specific Abs, and a decrease in the percentage of immunosuppressive regulatory T cells in the tumor. Moreover, in a therapeutic tumor model of cryoablation, only in tumors secreting vesicle-bound Ag could Ag-specific CD8(+) T cells still be detected up to 16 d after therapy. We concluded that the localization of an Ag within the tumor codetermines whether a robust immunostimulatory response is elicited. In vivo, vesicle-bound Ag clearly skews toward a more immunogenic phenotype, whereas soluble or cell-associated Ag expression cannot prevent or even delay outgrowth and results in tumor tolerance. This may explain why particular immunotherapies based on these vesicle-bound tumor Ags are potentially successful. Therefore, we conclude that this study may have significant implications in the discovery of new tumor Ags suitable for immunotherapy and that their location should be taken into account to ensure a strong antitumor immune response.

Photocatalytic reduction of CO2 by employing ZnO/Ag1-xCux/CdS and related heterostructures

NASA Astrophysics Data System (ADS)

Lingampalli, S. R.; Ayyub, Mohd Monis; Magesh, Ganesan; Rao, C. N. R.

2018-01-01

In view of the great importance of finding ways to reduce CO2 by using solar energy, we have examined the advantage of employing heterostructures containing bimetallic alloys for the purpose. This choice is based on the knowledge that metals such as Pt reduce CO2, although the activity may not be considerable. Our studies on the reduction of CO2 by ZnO/M/CdS (M = Ag, Au, Ag1-xAux, Ag1-xCux) heterostructures in liquid phase have shown good results specially in the case of ZnO/Ag1-xCux/CdS, reaching a CO production activity of 327.4 μmol h-1 g-1. The heterostructures also reduce CO2 in the gas-phase although the production activity is not high. Some of the heterostructures exhibit reduction of CO2 even in the absence of a sacrificial reagent.

The salen based chemosensors for highly selective recognition of Zn2+ ion.

PubMed

Zhu, Wenkai; Du, LongChao; Li, Wensheng; Zuo, Jinyan; Shan, Jingrui

2018-06-03

Two novel salen based chemosensors have been successfully synthesized. UV-vis absorption, fluorescence emission spectroscopy and cyclic voltammetry (CV) were exploited to investigate their recognition toward various metal ions, including Na + , K + , Mg 2+ , Al 3+ , Zn 2+ , Ag + , Pb 2+ , Co 2+ , Li + , Ba 2+ , Ca 2+ , Cd 2+ , La 3+ , Cu 2+ and Mn 2+ ions. The results indicated that the sensor L1 and L2 exhibited highly selective and sensitive recognition for Zn 2+ ions. The binding stoichiometry ratio of L1-Zn 2+ /L2-Zn 2+ were recognized as 4:1 by the method of Job's plot. Meanwhile, this investigation is confirmed by 1 H NMR. These results indicated that L1 and L2 can be applied as chemosensor for the detection of Zn 2+ ion. Copyright © 2018 Elsevier B.V. All rights reserved.

Sodium to sodium carbonate conversion process

DOEpatents

Herrmann, Steven D.

1997-01-01

A method of converting radioactive alkali metal into a low level disposable solid waste material. The radioactive alkali metal is atomized and introduced into an aqueous caustic solution having caustic present in the range of from about 20 wt % to about 70 wt % to convert the radioactive alkali metal to a radioactive alkali metal hydroxide. The aqueous caustic containing radioactive alkali metal hydroxide and CO.sub.2 are introduced into a thin film evaporator with the CO.sub.2 present in an amount greater than required to convert the alkali metal hydroxide to a radioactive alkali metal carbonate, and thereafter the radioactive alkali metal carbonate is separated from the thin film evaporator as a dry powder. Hydroxide solutions containing toxic metal hydroxide including one or more metal ions of Sb, As, Ba, Be, Cd, Cr, Pb, Hg, Ni, Se, Ag and T1 can be converted into a low level non-hazardous waste using the thin film evaporator of the invention.

"Naked-eye" colorimetric and "turn-on" fluorometric chemosensors for reversible Hg2+ detection.

PubMed

Wanichacheva, Nantanit; Praikaew, Panida; Suwanich, Thanapat; Sukrat, Kanjarat

2014-01-24

Two new Hg(2+)-colorimetric and fluorescent sensors based on 2-[3-(2-aminoethylsulfanyl) propylsulfanyl]ethanamine covalently bound to one and two units of rhodamine-6G moieties, 1 and 2, were synthesised, and their sensing behaviors toward metal ions were investigated by UV/Vis and fluorescence spectroscopy. Upon the addition of Hg(2+), the sensors exhibited highly sensitive "turn-on" fluorescence enhancement as well as a color change from colorless to pink, which was readily noticeable for naked eye detection. Especially, 1 exhibited the reversible behavior and revealed a very high selectivity in the presence of competitive ions, particularly Cu(2+), Ag(+), Pb(2+), Ca(2+), Cd(2+), Co(2+), Fe(2+), Mn(2+), Na(+), Ni(2+), K(+), Ba(2+), Li(+) and Zn(2+), with a low detection limit of 1.7 ppb toward Hg(2+). Copyright © 2013 Elsevier B.V. All rights reserved.

“Naked-eye” colorimetric and “turn-on” fluorometric chemosensors for reversible Hg2+ detection

NASA Astrophysics Data System (ADS)

Wanichacheva, Nantanit; Praikaew, Panida; Suwanich, Thanapat; Sukrat, Kanjarat

2014-01-01

Two new Hg2+-colorimetric and fluorescent sensors based on 2-[3-(2-aminoethylsulfanyl) propylsulfanyl]ethanamine covalently bound to one and two units of rhodamine-6G moieties, 1 and 2, were synthesised, and their sensing behaviors toward metal ions were investigated by UV/Vis and fluorescence spectroscopy. Upon the addition of Hg2+, the sensors exhibited highly sensitive “turn-on” fluorescence enhancement as well as a color change from colorless to pink, which was readily noticeable for naked eye detection. Especially, 1 exhibited the reversible behavior and revealed a very high selectivity in the presence of competitive ions, particularly Cu2+, Ag+, Pb2+, Ca2+, Cd2+, Co2+, Fe2+, Mn2+, Na+, Ni2+, K+, Ba2+, Li+ and Zn2+, with a low detection limit of 1.7 ppb toward Hg2+.

Experimental observation of Fano effect in Ag nanoparticle-CdTe quantum dot hybrid system

NASA Astrophysics Data System (ADS)

Gurung, Sabina; Jayabalan, J.; Singh, Asha; Khan, Salahuddin; Chari, Rama

2018-04-01

We have experimentally measured the optical properties of Ag nanoparticle-CdTe quantum dot hybrid system and compared it with that of bare CdTe quantum dot colloid. It has been shown that the photoluminescence line shape of CdTe quantum dots becomes asymmetric in presence of Ag nanoparticles. The observed changes in the PL spectrum closely match the expected changes in the line shape due to Fano interaction between discrete level and continuum levels. Our experiment shows that a very small fraction of metal nanoparticles in the metal-semiconductor hybrid is sufficient to induce such changes in line shape which is in contrary to the earlier reported theoretical prediction on metal-semiconductor hybrid.

Using elemental profiles and stable isotopes to trace the origin of green coffee beans on the global market.

PubMed

Santato, Alessandro; Bertoldi, Daniela; Perini, Matteo; Camin, Federica; Larcher, Roberto

2012-09-01

A broad elemental profile incorporating 54 elements (Li, Be, B, Na, Mg, Al, P, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Rb, Sr, Y, Mo, Pd, Ag, Cd, Sn, Sb, Te, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Er, Tm, Yb, Re, Ir, Pt, Au, Hg, Tl, Pb, Bi and U) in combination with δ(2) H, δ(13) C, δ(15) N and δ(18) O was used to characterise the composition of 62 green arabica (Coffea arabica) and robusta (Coffea canephora) coffee beans grown in South and Central America, Africa and Asia, the four most internationally renowned areas of production. The δ(2) H, Mg, Fe, Co and Ni content made it possible to correctly assign 95% of green coffee beans to the appropriate variety. Canonical discriminant analysis, performed using δ(13) C, δ(15) N, δ(18) O, Li, Mg, P, K, Mn, Co, Cu, Se, Y, Mo, Cd, La and Ce correctly traced the origin of 98% of coffee beans. Copyright © 2012 John Wiley & Sons, Ltd.

Status of metal levels and their potential sources of contamination in Southeast Asian rivers.

PubMed

Chanpiwat, Penradee; Sthiannopkao, Suthipong

2014-01-01

To assess the concentration and status of metal contaminants in four major Southeast Asian river systems, water were collected from the Tonle Sap-Bassac Rivers (Cambodia), Citarum River (Indonesia), lower Chao Phraya River (Thailand), and Saigon River (Vietnam) in both dry and wet seasons. The target elements were Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Ag, Cd, Ba, Tl, and Pb and the concentrations exceeded the background metal concentrations by 1- to 88-fold. This distinctly indicates enrichment by human urban area activities. The results of a normalization technique used to distinguish natural from enriched metal concentrations confirmed contamination by Al, Cd, Co, Mn, Ni, Pb, and Zn. Cluster analysis revealed the probable source of metals contamination in most sampling sites on all rivers studied to be anthropogenic, including industrial, commercial, and residential activities. Stable lead isotopes analyses applied to track the sources and pathways of anthropogenic lead furthermore confirmed that anthropogenic sources of metal contaminated these rivers. Discharges of wastewater from both industrial and household activities were major contributors of Pb into the rivers. Non-point sources, especially road runoff and street dust, also contributed contamination from Pb and other metals.

A Marked Reduction in Priming of Cytotoxic CD8+ T Cells Mediated by Stress-Induced Glucocorticoids Involves Multiple Deficiencies in Cross-Presentation by Dendritic Cells

PubMed Central

Hunzeker, John T.; Elftman, Michael D.; Mellinger, Jennifer C.; Princiotta, Michael F.; Bonneau, Robert H.; Truckenmiller, Mary E.; Norbury, Christopher C.

2013-01-01

Protracted psychological stress elevates circulating glucocorticoids, which can suppress CD8+ T cell-mediated immunity, but the mechanisms are incompletely understood. Dendritic cells (DCs), required for initiating CTL responses, are vulnerable to stress/corticosterone, which can contribute to diminished CTL responses. Cross-priming of CD8+ T cells by DCs is required for initiating CTL responses against many intracellular pathogens that do not infect DCs. We examined the effects of stress/corticosterone on MHC class I (MHC I) cross-presentation and priming and show that stress/corticosterone-exposed DCs have a reduced ability to cross-present OVA and activate MHC I-OVA257–264-specific T cells. Using a murine model of psychological stress and OVA-loaded β2-microglobulin knockout “donor” cells that cannot present Ag, DCs from stressed mice induced markedly less Ag-specific CTL proliferation in a glucocorticoid receptor-dependent manner, and endogenous in vivo T cell cytolytic activity generated by cross-presented Ag was greatly diminished. These deficits in cross-presentation/priming were not due to altered Ag donation, Ag uptake (phagocytosis, receptor-mediated endocytosis, or fluid-phase uptake), or costimulatory molecule expression by DCs. However, proteasome activity in corticosterone-treated DCs or splenic DCs from stressed mice was partially suppressed, which limits formation of antigenic peptide-MHC I complexes. In addition, the lymphoid tissue-resident CD11b−CD24+CD8α+ DC subset, which carries out cross-presentation/priming, was preferentially depleted in stressed mice. At the same time, CD11b−CD24+CD8α− DC precursors were increased, suggesting a block in development of CD8α+ DCs. Therefore, glucocorticoid-induced changes in both the cellular composition of the immune system and intracellular protein degradation contribute to impaired CTL priming in stressed mice. PMID:21098225

Default mode network activity in male adolescents with conduct and substance use disorder*

PubMed Central

Dalwani, Manish S.; Tregellas, Jason R.; Andrews-Hanna, Jessica R.; Mikulich-Gilbertson, Susan K.; Raymond, Kristen M.; Banich, Marie T.; Crowley, Thomas J.; Sakai, Joseph T.

2013-01-01

Background Adolescents with conduct disorder (CD) and substance use disorders (SUD) experience difficulty evaluating and regulating their behavior in anticipation of future consequences. Given the role of the brain's default mode network (DMN) in self-reflection and future thought, this study investigates whether DMN is altered in adolescents with CD and SUD, relative to controls. Methods Twenty adolescent males with CD and SUD and 20 male controls of similar ages underwent functional magnetic resonance imaging as they completed a risk-taking decision task. We used independent component analysis as a data-driven approach to identify the DMN spatial component in individual subjects. DMN activity was then compared between groups. Results Compared to controls, patients showed reduced activity in superior, medial and middle frontal gyrus (Brodmann area (BA) 10), retrosplenial cortex (BA 30) and lingual gyrus (BA 18), and bilateral middle temporal gryus (BA 21/22) - DMN regions thought to support self-referential evaluation, memory, foresight, and perspective taking. Furthermore, this pattern of reduced activity in patients remained robust after adjusting for the effects of depression and attention-deficit hyperactivity disorder (ADHD). Conversely, when not adjusting for effects of depression and ADHD, patients demonstrated greater DMN activity than controls solely in the cuneus (BA 19). Conclusions Collectively, these results suggest that comorbid CD and SUD in adolescents is characterized by atypical activity in brain regions thought to play an important role in introspective processing. These functional imbalances in brain networks may provide further insight into the neural underpinnings of conduct and substance use disorders. PMID:24210423

Controllable synthesis of metal selenide heterostructures mediated by Ag2Se nanocrystals acting as catalysts

NASA Astrophysics Data System (ADS)

Zhou, Jiangcong; Huang, Feng; Xu, Ju; Wang, Yuansheng

2013-09-01

Ag2Se nanocrystals were demonstrated to be novel semiconductor mediators, or in other word catalysts, for the growth of semiconductor heterostructures in solution. This is a result of the unique feature of Ag2Se as a fast ion conductor, allowing foreign cations to dissolve and then to heterogrow the second phase. Using Ag2Se nanocrystals as catalysts, dimeric metal selenide heterostructures such as Ag2Se-CdSe and Ag2Se-ZnSe, and even multi-segment heterostructures such as Ag2Se-CdSe-ZnSe and Ag2Se-ZnSe-CdSe, were successfully synthesized. Several interesting features were found in the Ag2Se based heterogrowth. At the initial stage of heterogrowth, a layer of the second phase forms on the surface of an Ag2Se nanosphere, with a curved junction interface between the two phases. With further growth of the second phase, the Ag2Se nanosphere tends to flatten the junction surface by modifying its shape from sphere to hemisphere in order to minimize the conjunct area and thus the interfacial energy. Notably, the crystallographic relationship of the two phases in the heterostructure varies with the lattice parameters of the second phase, in order to reduce the lattice mismatch at the interface. Furthermore, a small lattice mismatch at the interface results in a straight rod-like second phase, while a large lattice mismatch would induce a tortuous product. The reported results may provide a new route for developing novel selenide semiconductor heterostructures which are potentially applicable in optoelectronic, biomedical, photovoltaic and catalytic fields.Ag2Se nanocrystals were demonstrated to be novel semiconductor mediators, or in other word catalysts, for the growth of semiconductor heterostructures in solution. This is a result of the unique feature of Ag2Se as a fast ion conductor, allowing foreign cations to dissolve and then to heterogrow the second phase. Using Ag2Se nanocrystals as catalysts, dimeric metal selenide heterostructures such as Ag2Se-CdSe and Ag2Se-ZnSe, and even multi-segment heterostructures such as Ag2Se-CdSe-ZnSe and Ag2Se-ZnSe-CdSe, were successfully synthesized. Several interesting features were found in the Ag2Se based heterogrowth. At the initial stage of heterogrowth, a layer of the second phase forms on the surface of an Ag2Se nanosphere, with a curved junction interface between the two phases. With further growth of the second phase, the Ag2Se nanosphere tends to flatten the junction surface by modifying its shape from sphere to hemisphere in order to minimize the conjunct area and thus the interfacial energy. Notably, the crystallographic relationship of the two phases in the heterostructure varies with the lattice parameters of the second phase, in order to reduce the lattice mismatch at the interface. Furthermore, a small lattice mismatch at the interface results in a straight rod-like second phase, while a large lattice mismatch would induce a tortuous product. The reported results may provide a new route for developing novel selenide semiconductor heterostructures which are potentially applicable in optoelectronic, biomedical, photovoltaic and catalytic fields. Electronic supplementary information (ESI) available: Fig. S1-S8 and Table S1. See DOI: 10.1039/c3nr03601d

Herpes simplex virus antigens directly activate NK cells via TLR2, thus facilitating their presentation to CD4 T lymphocytes.

PubMed

Kim, Min; Osborne, Naomi R; Zeng, Weiguang; Donaghy, Heather; McKinnon, Kay; Jackson, David C; Cunningham, Anthony L

2012-05-01

NK cells infiltrate human herpetic lesions, but their role has been underexplored. HSV can stimulate innate immune responses via surface TLR2, which is expressed on monocyte-derived dendritic cells (DCs) and NK cells. In this study, UV-inactivated HSV1/2 and immunodominant HSV2 glycoprotein D peptides conjugated to the TLR2 agonist dipalmitoyl-S-glyceryl cysteine stimulated CD4 T lymphocyte IFN-γ responses within PBMCs or in coculture with monocyte-derived DCs. NK cells contributed markedly to the PBMC responses. Furthermore, NK cells alone were activated directly by both Ags, also upregulating HLA-DR and HLA-DQ and then they activated autologous CD4 T lymphocytes. Using Transwells, Ag-stimulated NK cells and CD4 T lymphocytes were shown to interact through both cell-to-cell contact and cytokines, differing in relative importance in different donors. A distinct immunological synapse between Ag-stimulated NK cells and CD4 T lymphocytes was observed, indicating the significance of their cell-to-cell contact. A large proportion (57%) of NK cells was also in contact with CD4 T lymphocytes in the dermal infiltrate of human recurrent herpetic lesions. Thus, NK cells stimulated by TLR2-activating HSV Ags can present Ag alone or augment the role of DCs in vitro and perhaps in herpetic lesions or draining lymph nodes. In addition to DCs, NK cells should be considered as targets for adjuvants during HSV vaccine development.

Amplifying IFN-γ Signaling in Dendritic Cells by CD11c-Specific Loss of SOCS1 Increases Innate Immunity to Infection while Decreasing Adaptive Immunity.

PubMed

Alice, Alejandro F; Kramer, Gwen; Bambina, Shelly; Baird, Jason R; Bahjat, Keith S; Gough, Michael J; Crittenden, Marka R

2018-01-01

Although prophylactic vaccines provide protective humoral immunity against infectious agents, vaccines that elicit potent CD8 T cell responses are valuable tools to shape and drive cellular immunity against cancer and intracellular infection. In particular, IFN-γ-polarized cytotoxic CD8 T cell immunity is considered optimal for protective immunity against intracellular Ags. Suppressor of cytokine signaling (SOCS)1 is a cross-functional negative regulator of TLR and cytokine receptor signaling via degradation of the receptor-signaling complex. We hypothesized that loss of SOCS1 in dendritic cells (DCs) would improve T cell responses by accentuating IFN-γ-directed immune responses. We tested this hypothesis using a recombinant Listeria monocytogenes vaccine platform that targets CD11c + DCs in mice in which SOCS1 is selectively deleted in all CD11c + cells. Unexpectedly, in mice lacking SOCS1 expression in CD11c + cells, we observed a decrease in CD8 + T cell response to the L. monocytogenes vaccine. NK cell responses were also decreased in mice lacking SOCS1 expression in CD11c + cells but did not explain the defect in CD8 + T cell immunity. We found that DCs lacking SOCS1 expression were functional in driving Ag-specific CD8 + T cell expansion in vitro but that this process was defective following infection in vivo. Instead, monocyte-derived innate TNF-α and inducible NO synthase-producing DCs dominated the antibacterial response. Thus, loss of SOCS1 in CD11c + cells skewed the balance of immune response to infection by increasing innate responses while decreasing Ag-specific adaptive responses to infectious Ags. Copyright © 2017 by The American Association of Immunologists, Inc.

CTLA-4 polymorphisms and susceptibility to inflammatory bowel disease: a meta-analysis.

PubMed

Lee, Young Ho; Kim, Jae-Hoon; Seo, Young Ho; Choi, Sung Jae; Ji, Jong Dae; Song, Gwan Gyu

2014-05-01

The aim of this study was to explore whether the cytotoxic T lymphocyte associated antigen-4 (CTLA-4) polymorphisms are associated with susceptibility to ulcerative colitis (UC) and Crohn's disease (CD). The authors conducted a meta-analysis on associations between CTLA-4 +49 A/G, -318 C/T, CT60 A/G polymorphisms, and (AT)n repeat in the 3' untranslated region (UTR) and UC and CD susceptibility. A total of 15 comparison studies were considered in our meta-analysis. Meta-analysis revealed no association between UC and the CTLA-4 +49 G and CTLA-4 -318 T alleles in all subjects (OR=0.982, 95% CI=0.851-1.1339, p=0.804; OR=0.500, 95% CI=0.223-1.124, p=0.094). No association was found between UC and the CTLA-4 CT60 A/G polymorphism in Europeans. However, a significant association was observed between the longer allele (⩾118bp) of the (AT)n and UC in Asian population (OR=6.073, 95% CI=4.246-8.684, p=1.0×10(-9)). Meta-analysis of the CTLA-4 +49 A/G, -318 C/T, CT60 A/G polymorphisms showed no association with CD. This meta-analysis demonstrates that the CTLA-4 (AT)n repeat in 3' UTR may be associated with susceptibility to UC in Asians, while no association was found between the CTLA-4 +49 A/G, -318 C/T, and CD60 A/G polymorphism and susceptibility to UC and CD. Copyright © 2014 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

Invoking Direct Exciton-Plasmon Interactions by Catalytic Ag Deposition on Au Nanoparticles: Photoelectrochemical Bioanalysis with High Efficiency.

PubMed

Ma, Zheng-Yuan; Xu, Fei; Qin, Yu; Zhao, Wei-Wei; Xu, Jing-Juan; Chen, Hong-Yuan

2016-04-19

In this work, direct exciton-plasmon interactions (EPI) between CdS quantum dots (QDs) and Ag nanoparticles (NPs) were invoked ingeniously by catalytic Ag deposition on Au NPs for the stimulation of high efficient damping effect toward the excitonic responses in CdS QDs, on the basis of which a novel photoelectrochemical (PEC) bioanalytical format was achieved for sensitive microRNA detection. Specifically, upon the configurational change from the hairpin probe DNA to the "Y"-shaped ternary conjugate consisting of the original probe DNA, assistant DNA, and the target microRNA, the alkaline phosphatase (ALP) catalytic chemistry would then trigger the transition of the interparticle interplay from the CdS QDs-Au NPs to the CdS QDs-Ag NPs systems for the microRNA detection due to the dependence of the photocurrent quenching on the target concentration. This work not only provided a unique method for EPI generation among the PEC nanosystems but also offered a versatile and general protocol for future PEC bioanalysis development.

Assimilation efficiencies and turnover rates of trace elements in marine bivalves: A comparison of oysters, clams and mussels

USGS Publications Warehouse

Reinfelder, J.R.; Wang, W.-X.; Luoma, S. N.; Fisher, N.S.

1997-01-01

Assimilation efficiencies (AEs) and physiological turnover-rate constants (k) of six trace elements (Ag, Am, Cd, Co, Se, Zn) in four marine bivalves (Crassostrea virginica Gmelin,Macoma balthica Linnaeus, Mercenaria mercenaria Linnaeus, and Mytilus edulis Linnaeus) were measured in radiotracer-depuration experiments. Egestion rates of unassimilated elements were highest during the first 24 h of depuration and declined thereafter. Significant egestion of unassimilated Co, however, continued for up to 5 d in Macoma balthica,Mercenaria mercenaria and Mytilus edulis. With the exception of the extremely low values for110 mAg, 109Cd, and 65Zn in C. virginica, physiological turnover-rate constants (k) showed no general pattern of variation among elements, bivalve species or food types, and were relatively invariant. Values from  ≤0.001 to 0.1 d−1 were observed, but excluding those for Co, most values were  ≤0.04 d−1. In all four species, the AEs of Ag, Am, and Co were generally lower than those of Cd, Se, and Zn. The AEs of Ag, Cd, Se, and Zn in these bivalves are directly related to the proportion of each element in the cytoplasmic fraction of ingested phytoplankton, indicating that >80% of elements in a prey alga's cytoplasm was assimilated. C. virginica, Macoma balthica, and Mercenaria mercenaria assimilated ∼36% of the Ag and Cd associated with the non-cytoplasmic (membrane/organelle) fraction of ingested cells in addition to the cytoplasmic fraction. The ratio of AE:k, which is proportional to the consumer–prey trace-element bioaccumulation factor (concentration in consumer:concentration in prey) was generally greater for Cd, Se, and Zn than for Ag, Am, and Co. This ratio was lowest in Mytilus edulis, suggesting that this bivalve, the most widely employed organism in global biomonitoring, is relatively inefficient at accumulating important elements such as Ag, Cd, and Zn from ingested phytoplankton.

Synthesis, characterizations and anti-bacterial activities of pure and Ag doped CdO nanoparticles by chemical precipitation method

NASA Astrophysics Data System (ADS)

Sivakumar, S.; Venkatesan, A.; Soundhirarajan, P.; Khatiwada, Chandra Prasad

2015-02-01

In the present study, synthesized pure and Ag (1%, 2%, and 3%) doped Cadmium Oxide (CdO) nanoparticles by chemical precipitation method. Then, the synthesized products were characterized by thermo gravimetric-differential thermal analysis (TG-DTA), X-ray diffraction (XRD) analysis, Fourier transform infrared (FT-IR) spectroscopy, Ultra violet-Vis diffused reflectance spectroscopy (UV-Vis-DRS), Scanning electron microscopy (SEM), Energy dispersive X-rays (EDX) spectroscopy, and anti-bacterial activities, respectively. The transition temperatures and phase transitions of Cd(OH)2 to CdO at 400 °C was confirmed by TG-DTA analysis. The XRD patterns show the cubic shape and average particle sizes are 21, 40, 34, and 37 nm, respectively for pure and Ag doped samples. FT-IR study confirmed the presence of CdO and Ag at 677 and 459 cm-1, respectively. UV-Vis-DRS study shows the variation on direct and indirect band gaps. The surface morphologies and elemental analysis have been confirmed from SEM and with EDX. In addition, the synthesized products have been characterized by antibacterial activities against Gram-positive and negative bacteria. Further, the present investigation suggests that CdO nanoparticles have the great potential applications on various industrial and medical fields of research.

Leukocyte function-associated antigen-1-dependent lysis of Fas+ (CD95+/Apo-1+) innocent bystanders by antigen-specific CD8+ CTL.

PubMed

Kojima, H; Eshima, K; Takayama, H; Sitkovsky, M V

1997-09-15

Exquisite specificity toward Ag-bearing cells (cognate targets) is one of the most important properties of CD8+ CTL-mediated cytotoxicity. Using highly Ag-specific CD8+ CTL lines and clones, which spare noncognate, Ag-free targets, we found that in the presence of Ag-bearing targets the CTL acquire the ability to lyse noncognate target cells (bystanders). It is shown that the unexpectedly rapid and efficient lysis of bystanders by Ag-activated CTL is mediated by a Fas ligand (FasL)/Fas-based mechanism and does not depend on perforin. The CTL lysed Fas-expressing bystanders, but spared the Fas-negative or anti-Fas mAb-resistant bystander cells. Accordingly, the FasL-deficient gld/gld CTL did not kill bystanders, while perforin-deficient CTL did. Unlike anti-Fas mAb-induced cell death, the lysis of bystanders was not only FasL/Fas dependent but also required adhesion molecule LFA-1 on the surface of the activated CTL. Lysis of bystanders is viewed as acceptable "collateral" damage, but the persistent presence of activated CTL could result in immunopathologies involving functional Fas-expressing tissues.

Feasibility and Acceptability of Cryptococcal Antigen Screening and Prevalence of Cryptocococcemia in Patients Attending a Resource-Limited HIV/AIDS Clinic in Malawi.

PubMed

Chipungu, Chifundo; Veltman, Jennifer A; Jansen, Perry; Chiliko, Peter; Lossa, Christina; Namarika, Dan; Benner, Blake; Hoffman, Risa M; Bristow, Claire C; Klausner, Jeffrey D

2015-01-01

The World Health Organization (WHO) recommends screening patients living with AIDS to detect and treat early cryptococcal infection. The authors evaluated a cryptococcal antigen (CrAg) screening and treatment program at an HIV/AIDS clinic in Malawi. Eligible patients were of age >18 years, had a CD4 count <100 cells/µL or WHO clinical HIV/AIDS stage III or IV. Of 552 patients who presented for care, 113 were eligible, and all (100%) agreed to CrAg screening. Of them, 2 (1.8%; 95% confidence interval [CI]: 0-4.2%) patients were CrAg positive. Among those with CD4 count <100 cells/µL or WHO stage IV, the CrAg prevalence was 3.5% (95% CI: 0-8.4%) and 5.0% (95% CI: 0-15%), respectively. A CrAg screening program was acceptable to new patients in a Malawian HIV/AIDS clinic. The CrAg prevalence for patients with CD4 count < 100 cells/µL and WHO stage IV was consistent with cost-effectiveness estimates. CrAg screening and treatment programs for patients living with AIDS should be expanded. © The Author(s) 2015.

Levels of human platelet-derived soluble CD40 ligand depend on haplotypes of CD40LG-CD40-ITGA2

PubMed Central

Aloui, Chaker; Prigent, Antoine; Tariket, Sofiane; Sut, Caroline; Fagan, Jocelyne; Cognasse, Fabrice; Chakroun, Tahar; Garraud, Olivier; Laradi, Sandrine

2016-01-01

Increased circulating soluble CD40 ligand (sCD40L) is commonly associated with inflammatory disorders. We aimed to investigate whether gene polymorphisms in CD40LG, CD40 and ITGA2 are associated with a propensity to secrete sCD40L; thus, we examined this issue at the level of human platelets, the principal source of sCD40L. We performed single polymorphism and haplotype analyses to test for the effect of twelve polymorphisms across the CD40LG, CD40 and ITGA2 genes in blood donors. ITGA2 presented a positive association with rs1126643, with a significant modification in sCD40L secretion (carriers of C allele, P = 0.02), unlike the investigated CD40LG and CD40 polymorphisms. One CD40LG haplotype (TGGC) showing rs975379 (C/T), rs3092952 (A/G), rs3092933 (A/G) and rs3092929 (A/C) was associated with increased sCD40L levels (1.906 μg/L (95% CI: 1.060 to 2.751); P = 0.000009). The sCD40L level was associated with the inter-chromosomal CD40LG/CD40/ITGA2 haplotype (ATC), displaying rs3092952 (A/G), rs1883832 (C/T) and rs1126643 (C/T), with increased sCD40L levels (P = 0.0135). Our results help to decipher the genetic role of CD40LG, CD40 and ITGA2 with regard to sCD40L levels found in platelet components. Given the crucial role of sCD40L, this haplotype study in a transfusion model may be helpful to further determine the role of haplotypes in inflammatory clinical settings. PMID:27094978

Magnesium and cadmium containing Heusler phases REPd2Mg, REPd2Cd, REAg2Mg, REAu2Mg and REAu2Cd

NASA Astrophysics Data System (ADS)

Johnscher, Michael; Stein, Sebastian; Niehaus, Oliver; Benndorf, Christopher; Heletta, Lukas; Kersting, Marcel; Höting, Christoph; Eckert, Hellmut; Pöttgen, Rainer

2016-02-01

Twenty-eight new Heusler phases REPd2Mg, REPd2Cd, REAg2Mg, REAu2Mg and REAu2Cd with different rare earth elements were synthesized from the elements in sealed niobium ampoules in a water-cooled sample chamber of an induction furnace. The samples were characterized by powder X-ray diffraction. The cell volumes show the expected lanthanide contraction. The structures of YPd2Cd, GdPd2Cd, GdAu2Cd, Y1.12Ag2Mg0.88 and GdAg2Mg were refined based on single crystal diffractometer data. The magnetic properties were determined for fifteen phase pure samples. LuAu2Mg is a weak Pauli paramagnet with a susceptibility of 1.0(2) × 10-5 emu mol-1 at room temperature. The remaining samples show stable trivalent rare earth ions and most of them order magnetically at low temperatures. The ferromagnet GdAg2Mg shows the highest ordering temperature of TC = 98.3 K. 113Cd and 89Y MAS NMR spectra of YAu2Cd and YPd2Cd confirm the presence of unique crystallographic sites. The resonances are characterized by large Knight shifts, whose magnitude can be correlated with electronegativity trends.

Ag85A-specific CD4+ T cell lines derived after boosting BCG-vaccinated cattle with Ad5-85A possess both mycobacterial growth inhibition and anti-inflammatory properties.

PubMed

Metcalfe, Hannah J; Biffar, Lucia; Steinbach, Sabine; Guzman, Efrain; Connelley, Tim; Morrison, Ivan; Vordermeier, H Martin; Villarreal-Ramos, Bernardo

2018-05-11

There is a need to improve the efficacy of the BCG vaccine against human and bovine tuberculosis. Previous data showed that boosting bacilli Calmette-Guerin (BCG)-vaccinated cattle with a recombinant attenuated human type 5 adenovirally vectored subunit vaccine (Ad5-85A) increased BCG protection and was associated with increased frequency of Ag85A-specific CD4 + T cells post-boosting. Here, the capacity of Ag85A-specific CD4 + T cell lines - derived before and after viral boosting - to interact with BCG-infected macrophages was evaluated. No difference before and after boosting was found in the capacity of these Ag85A-specific CD4 + T cell lines to restrict mycobacterial growth, but the secretion of IL-10 in vitro post-boost increased significantly. Furthermore, cell lines derived post-boost had no statistically significant difference in the secretion of pro-inflammatory cytokines (IL-1β, IL-12, IFNγ or TNFα) compared to pre-boost lines. In conclusion, the protection associated with the increased number of Ag85A-specific CD4 + T cells restricting mycobacterial growth may be associated with anti-inflammatory properties to limit immune-pathology. Copyright © 2018 Department for Environment Food and Rural Affairs. Published by Elsevier Ltd.. All rights reserved.

AgCl-doped CdSe quantum dots with near-IR photoluminescence.

PubMed

Kotin, Pavel Aleksandrovich; Bubenov, Sergey Sergeevich; Mordvinova, Natalia Evgenievna; Dorofeev, Sergey Gennadievich

2017-01-01

We report the synthesis of colloidal CdSe quantum dots doped with a novel Ag precursor: AgCl. The addition of AgCl causes dramatic changes in the morphology of synthesized nanocrystals from spherical nanoparticles to tetrapods and finally to large ellipsoidal nanoparticles. Ellipsoidal nanoparticles possess an intensive near-IR photoluminescence ranging up to 0.9 eV (ca. 1400 nm). In this article, we explain the reasons for the formation of the ellipsoidal nanoparticles as well as the peculiarities of the process. The structure, Ag content, and optical properties of quantum dots are also investigated. The optimal conditions for maximizing both the reaction yield and IR photoluminescence quantum yield are found.

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

Kaur, Ramneek; Tripathi, S. K., E-mail: surya@pu.ac.in, E-mail: surya-tr@yahoo.com

This paper reports the synthesis and electrical characterization of CdSe-PMMA nanocomposite. CdSe-PMMA nanocomposite has been prepared by ex-situ technique through chemical route. The influence of three different Ag doping concentrations on the electrical properties has been studied in the temperature range ∼ 303-353 K. Transmission electron micrograph reveals the spherical morphology of the CdSe nanoparticles and their proper dispersion in the PMMA matrix. The electrical conduction of the polymer nanocomposites is through thermally activated process with single activation energy. With Ag doping, initially the activation energy increases upto 0.2 % Ag doping concentration but with further increase in Ag concentration, itmore » decreases. This behavior has been discussed on the basis of randomly oriented grain boundaries and defect states. Thus, the results indicate that the transport properties of the polymer nanocomposites can be tailored by controlled doping concentration.« less

Comparison of four USEPA digestion methods for trace metal analysis using certified and Florida soils

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

Chen, M.; Ma, L.Q.

1998-11-01

It is critical to compare existing sample digestion methods for evaluating soil contamination and remediation. USEPA Methods 3050, 3051, 3051a, and 3052 were used to digest standard reference materials and representative Florida surface soils. Fifteen trace metals (Ag, As, Ba, Be, Cd, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Sb, Se, and Za), and six macro elements (Al, Ca, Fe, K, Mg, and P) were analyzed. Precise analysis was achieved for all elements except for Cd, Mo, Se, and Sb in NIST SRMs 2704 and 2709 by USEPA Methods 3050 and 3051, and for all elements except for As, Mo,more » Sb, and Se in NIST SRM 2711 by USEPA Method 3052. No significant differences were observed for the three NIST SRMs between the microwave-assisted USEPA Methods 3051 and 3051A and the conventional USEPA Method 3050 Methods 3051 and 3051a and the conventional USEPA Method 3050 except for Hg, Sb, and Se. USEPA Method 3051a provided comparable values for NIST SRMs certified using USEPA Method 3050. However, for method correlation coefficients and elemental recoveries in 40 Florida surface soils, USEPA Method 3051a was an overall better alternative for Method 3050 than was Method 3051. Among the four digestion methods, the microwave-assisted USEPA Method 3052 achieved satisfactory recoveries for all elements except As and Mg using NIST SRM 2711. This total-total digestion method provided greater recoveries for 12 elements Ag, Be, Cr, Fe, K, Mn, Mo, Ni, Pb, Sb, Se, and Zn, but lower recoveries for Mg in Florida soils than did the total-recoverable digestion methods.« less

Targeting Mycobacterium tuberculosis Antigens to Dendritic Cells via the DC-Specific-ICAM3-Grabbing-Nonintegrin Receptor Induces Strong T-Helper 1 Immune Responses

PubMed Central

Velasquez, Lis Noelia; Stüve, Philipp; Gentilini, Maria Virginia; Swallow, Maxine; Bartel, Judith; Lycke, Nils Yngve; Barkan, Daniel; Martina, Mariana; Lujan, Hugo D.; Kalay, Hakan; van Kooyk, Yvette; Sparwasser, Tim D.; Berod, Luciana

2018-01-01

Tuberculosis remains a major global health problem and efforts to develop a more effective vaccine have been unsuccessful so far. Targeting antigens (Ags) to dendritic cells (DCs) in vivo has emerged as a new promising vaccine strategy. In this approach, Ags are delivered directly to DCs via antibodies that bind to endocytic cell-surface receptors. Here, we explored DC-specific-ICAM3-grabbing-nonintegrin (DC-SIGN) targeting as a potential vaccine against tuberculosis. For this, we made use of the hSIGN mouse model that expresses human DC-SIGN under the control of the murine CD11c promoter. We show that in vitro and in vivo delivery of anti-DC-SIGN antibodies conjugated to Ag85B and peptide 25 of Ag85B in combination with anti-CD40, the fungal cell wall component zymosan, and the cholera toxin-derived fusion protein CTA1-DD induces strong Ag-specific CD4+ T-cell responses. Improved anti-mycobacterial immunity was accompanied by increased frequencies of Ag-specific IFN-γ+ IL-2+ TNF-α+ polyfunctional CD4+ T cells in vaccinated mice compared with controls. Taken together, in this study we provide the proof of concept that the human DC-SIGN receptor can be efficiently exploited for vaccine purposes to promote immunity against mycobacterial infections. PMID:29662482

Raman tensor elements for tetragonal BaTiO3 and their use for in-plane domain texture assessments

NASA Astrophysics Data System (ADS)

Deluca, Marco; Higashino, Masayuki; Pezzotti, Giuseppe

2007-08-01

A quantitative assessment of c-axis oriented domains in a textured BaTiO3 (BT) single crystal has been carried out by polarized Raman microprobe spectroscopy. The relative intensity modulation of the Raman phonon modes has been theoretically modeled as a function of crystal rotation and linked to the volume fraction of c-axis oriented domains. Raman tensor elements have also been experimentally determined for the Ag and B1 vibrational modes. As an application, the internal in-plane texture and the volume fraction of c-oriented domains in the BT single crystal have been nondestructively visualized by monitoring the relative intensity of Ag and B1 Raman modes.

Enhanced Photoelectrochemical Activity by Autologous Cd/CdO/CdS Heterojunction Photoanodes with High Conductivity and Separation Efficiency.

PubMed

Xie, Shilei; Zhang, Peng; Zhang, Min; Liu, Peng; Li, Wei; Lu, Xihong; Cheng, Faliang; Tong, Yexiang

2017-07-18

The development for hydrogen from solar energy has attracted great attention due to the global demand for clean, environmentally friendly energy. Herein, autologous Cd/CdO/CdS heterojunctions were prepared in a carefully controlled process with metallic Cd as the inner layer and CdO as the interlayer. Further research revealed that the transportation and separation of photogenerated pairs were enhanced due to low resistance of the Cd inner layer and the type II CdO/CdS heterojunction. As a result, the optimized Cd/CdO/CdS heterojunction photoanode showed outstanding and long-term photoelectrochemical activity for water splitting, with a current density of 3.52 mA cm -2 , or a benchmark specific hydrogen production rate of 1.65 μmol cm -2  min -1 at -0.3 V versus Ag/AgCl, by using the environmental pollutants of sulfide and sulfite as sacrificial agents. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Carbon Dioxide Gas Sensors and Method of Manufacturing and Using Same

NASA Technical Reports Server (NTRS)

Liu, Chung Chiun (Inventor); Ward, Benjamin J. (Inventor); Hunter, Gary W. (Inventor); Xu, Jennifer C. (Inventor)

2011-01-01

A gas sensor includes a substrate and a pair of interdigitated metal electrodes selected from the group consisting of Pt, Pd, Au, Ir, Ag, Ru, Rh, In, and Os. The electrodes each include an upper surface. A first solid electrolyte resides between the interdigitated electrodes and partially engages the upper surfaces of the electrodes. The first solid electrolyte is selected from the group consisting of NASICON, LISICON, KSICON, and .beta.''-Alumina (beta prime-prime alumina in which when prepared as an electrolyte is complexed with a mobile ion selected from the group consisting of Na.sup.+, K.sup.+, Li.sup.+, Ag.sup.+, H.sup.+, Pb.sup.2+, Sr.sup.2+ or Ba.sup.2+). A second electrolyte partially engages the upper surfaces of the electrodes and engages the first solid electrolyte in at least one point. The second electrolyte is selected from the group of compounds consisting of Na.sup.+, K.sup.+, Li.sup.+, Ag.sup.+, H.sup.+, Pb.sup.2+, Sr.sup.2+ or Ba.sup.2+ ions or combinations thereof.

Establishing a cost-per-result of laboratory-based, reflex Cryptococcal antigenaemia screening (CrAg) in HIV+ patients with CD4 counts less than 100 cells/μl using a Lateral Flow Assay (LFA) at a typical busy CD4 laboratory in South Africa.

PubMed

Cassim, Naseem; Schnippel, Kathryn; Coetzee, Lindi Marie; Glencross, Deborah Kim

2017-01-01

Cryptococcal meningitis is a major cause of mortality and morbidity in countries with high HIV prevalence, primarily affecting patients whose CD4 are < = 100 cells/μl. Routine Cryptococcal Antigen (CrAg) screening is thus recommended in the South African HIV treatment guidelines for all patients with CD4 counts < = 100 cells/μl, followed by pre-emptive anti-fungal therapy where CrAg results are positive. A laboratory-based reflexed CrAg screening approach, using a Lateral Flow Assay (LFA) on remnant EDTA CD4 blood samples, was piloted at three CD4 laboratories. This study aimed to assess the cost-per-result of laboratory-based reflexed CrAg screening at one pilot CD4 referral laboratory. CD4 test volumes from 2014 were extracted to estimate percentage of CD4 < = 100 cells/μl. Daily average volumes were derived, assuming 12 months per/year and 21.73 working days per/month. Costing analyses were undertaken using Microsoft Excel and Stata with a provider prospective. The cost-per-result was estimated using a bottom-up method, inclusive of test kits and consumables (reagents), laboratory equipment and technical effort costs. The ZAR/$ exchange of 14.696/$1 was used, where applicable. One-way sensitivity analyses on the cost-per-result were conducted for possible error rates (3%- 8%, reductions or increases in reagent costs as well as test volumes (ranging from -60% to +60%). The pilot CD4 laboratory performed 267000 CD4 tests in 2014; ~ 9.3% (27500) reported CD4< = 100 cells/μl, equivalent to 106 CrAg tests performed daily. A batch of 30-tests could be performed in 1.6 hours, including preparation and analysis time. A cost-per-result of $4.28 was reported, with reagents contributing $3.11 (72.8%), while technical effort and laboratory equipment overheads contributed $1.17 (27.2%) and $0.03 (<1%) respectively. One-way sensitivity analyses including increasing or decreasing test volumes by 60% revealed a cost-per-result range of $3.84 to $6.03. A cost-per-result of $4.28 was established in a typical CD4 service laboratory to enable local budgetary cost projections and programmatic cost-effectiveness modelling. Varying reagent costs linked to currency exchange and varying test volumes in different levels of service can lead to varying cost-per-test and technical effort to manage workload, with an inverse relationship of higher costs expected at lower volumes of tests.

Controllable synthesis of metal selenide heterostructures mediated by Ag2Se nanocrystals acting as catalysts.

PubMed

Zhou, Jiangcong; Huang, Feng; Xu, Ju; Wang, Yuansheng

2013-10-21

Ag2Se nanocrystals were demonstrated to be novel semiconductor mediators, or in other word catalysts, for the growth of semiconductor heterostructures in solution. This is a result of the unique feature of Ag2Se as a fast ion conductor, allowing foreign cations to dissolve and then to heterogrow the second phase. Using Ag2Se nanocrystals as catalysts, dimeric metal selenide heterostructures such as Ag2Se-CdSe and Ag2Se-ZnSe, and even multi-segment heterostructures such as Ag2Se-CdSe-ZnSe and Ag2Se-ZnSe-CdSe, were successfully synthesized. Several interesting features were found in the Ag2Se based heterogrowth. At the initial stage of heterogrowth, a layer of the second phase forms on the surface of an Ag2Se nanosphere, with a curved junction interface between the two phases. With further growth of the second phase, the Ag2Se nanosphere tends to flatten the junction surface by modifying its shape from sphere to hemisphere in order to minimize the conjunct area and thus the interfacial energy. Notably, the crystallographic relationship of the two phases in the heterostructure varies with the lattice parameters of the second phase, in order to reduce the lattice mismatch at the interface. Furthermore, a small lattice mismatch at the interface results in a straight rod-like second phase, while a large lattice mismatch would induce a tortuous product. The reported results may provide a new route for developing novel selenide semiconductor heterostructures which are potentially applicable in optoelectronic, biomedical, photovoltaic and catalytic fields.

Increased B and T Cell Responses in M. bovis Bacille Calmette-Guérin Vaccinated Pigs Co-Immunized with Plasmid DNA Encoding a Prototype Tuberculosis Antigen

PubMed Central

Bruffaerts, Nicolas; Pedersen, Lasse E.; Vandermeulen, Gaëlle; Préat, Véronique; Stockhofe-Zurwieden, Norbert; Huygen, Kris; Romano, Marta

2015-01-01

The only tuberculosis vaccine currently available, bacille Calmette-Guérin (BCG) is a poor inducer of CD8+ T cells, which are particularly important for the control of latent tuberculosis and protection against reactivation. As the induction of strong CD8+ T cell responses is a hallmark of DNA vaccines, a combination of BCG with plasmid DNA encoding a prototype TB antigen (Ag85A) was tested. As an alternative animal model, pigs were primed with BCG mixed with empty vector or codon-optimized pAg85A by the intradermal route and boosted with plasmid delivered by intramuscular electroporation. Control pigs received unformulated BCG. The BCG-pAg85A combination stimulated robust and sustained Ag85A specific antibody, lymphoproliferative, IL-6, IL-10 and IFN-γ responses. IgG1/IgG2 antibody isotype ratio reflected the Th1 helper type biased response. T lymphocyte responses against purified protein derivative of tuberculin (PPD) were induced in all (BCG) vaccinated animals, but responses were much stronger in BCG-pAg85A vaccinated pigs. Finally, Ag85A-specific IFN-γ producing CD8+ T cells were detected by intracellular cytokine staining and a synthetic peptide, spanning Ag85A131-150 and encompassing two regions with strong predicted SLA-1*0401/SLA-1*0801 binding affinity, was promiscuously recognized by 6/6 animals vaccinated with the BCG-pAg85A combination. Our study provides a proof of concept in a large mammalian species, for a new Th1 and CD8+ targeting tuberculosis vaccine, based on BCG-plasmid DNA co-administration. PMID:26172261

Histone Acetylation at the Ifng Promoter in Tolerized CD4 Cells Is Associated with Increased IFN-γ Expression during Subsequent Immunization to the Same Antigen1

PubMed Central

Long, Meixiao; Slaiby, Aaron M.; Wu, Shuang; Hagymasi, Adam T.; Mihalyo, Marianne A.; Bandyopadhyay, Suman; Vella, Anthony T.; Adler, Adam J.

2010-01-01

When naive CD4+ Th cells encounter cognate pathogen-derived Ags they expand and develop the capacity to express the appropriate effector cytokines for neutralizing the pathogen. Central to this differentiation process are epigenetic modifications within the effector cytokine genes that allow accessibility to the transcriptional machinery. In contrast, when mature self-reactive CD4 cells encounter their cognate epitopes in the periphery they generally undergo a process of tolerization in which they become hyporesponsive/anergic to antigenic stimulation. In the current study, we used a TCR transgenic adoptive transfer system to demonstrate that in a dose-dependent manner parenchymal self-Ag programs cognate naive CD4 cells to acetylate histones bound to the promoter region of the Ifng gene (which encodes the signature Th1 effector cytokine) during peripheral tolerization. Although the Ifng gene gains transcriptional competence, these tolerized CD4 cells fail to express substantial amounts of IFN-γ in response to antigenic stimulation apparently because a blockage in TCR-mediated signaling also develops. Nevertheless, responsiveness to antigenic stimulation is partially restored when self-Ag-tolerized CD4 cells are retransferred into mice infected with a virus expressing the same Ag. Additionally, there is preferential boosting in the ability of these CD4 cells to express IFN-γ relative to other cytokines with expression that also becomes impaired. Taken together, these results suggest that epigenetic modification of the Ifng locus during peripheral CD4 cell tolerization might allow for preferential expression of IFN-γ during recovery from tolerance. PMID:17947638

Anodic stripping voltammetry of synthesized CdS nanoparticles at boron-doped diamond electrodes

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

Hayat, Mohammad; Ivandini, Tribidasari A., E-mail: ivandini.tri@sci.ui.ac.id; Saepudin, Endang

Cadmium sulphide (CdS) nanoparticles were chemically synthesized using reverse micelles microreactor methods. By using different washing treatments, UV-Vis spectroscopy showed that the absorption peaks appeared at 465 nm, 462 nm, 460 nm, and 459 nm respectively for CdS nanoparticles without and with 1, 2, and 3 times washing treatments using pure water. In comparison with the absorbance peak of bulk CdS at 512 nm, the shifted absorption peaks, indicates that the different sizes of CdS can be prepared. Anodic stripping voltammetry of the CdS nanoparticles was then studied at a boron-doped diamond electrode using 0.1 M KClO{sub 4} and 0.1 M HClO{sub 4} as themore » electrolytes. A scan rate of 100 mV/s with a deposition potential of -1000 mV (vs. Ag/AgCl) for 60 s at a potential scan from -1600 mV to +800 mV (vs. Ag/AgCl) was applied as the optimum condition of the measurements. Highly-accurate linear calibration curves (R{sup 2} = 0.99) in 0.1 M HClO{sub 4} with the sensitivity of 0.075 mA/mM and the limit of detection of 81 µM in 0.1 M HClO{sub 4} can be achieved, which is promising for an application of CdS nanoparticles as a label for biosensors.« less

Concentrations of lead, cadmium and barium in urban garden-grown vegetables: the impact of soil variables

PubMed Central

McBride, Murray B.; Shayler, Hannah A.; Spliethoff, Henry M.; Mitchell, Rebecca G.; Marquez-Bravo, Lydia G.; Ferenz, Gretchen S.; Russell-Anelli, Jonathan M.; Casey, Linda; Bachman, Sharon

2014-01-01

Paired vegetable/soil samples from New York City and Buffalo, NY, gardens were analyzed for lead (Pb), cadmium (Cd) and barium (Ba). Vegetable aluminum (Al) was measured to assess soil adherence. Soil and vegetable metal concentrations did not correlate; vegetable concentrations varied by crop type. Pb was below health-based guidance values (EU standards) in virtually all fruits. 47% of root crops and 9% of leafy greens exceeded guidance values; over half the vegetables exceeded the 95th percentile of market-basket concentrations for Pb. Vegetable Pb correlated with Al; soil particle adherence/incorporation was more important than Pb uptake via roots. Cd was similar to market-basket concentrations and below guidance values in nearly all samples. Vegetable Ba was much higher than Pb or Cd, although soil Ba was lower than soil Pb. The poor relationship between vegetable and soil metal concentrations is attributable to particulate contamination of vegetables and soil characteristics that influence phytoavailability. PMID:25163429

Concentrations of lead, cadmium and barium in urban garden-grown vegetables: the impact of soil variables.

PubMed

McBride, Murray B; Shayler, Hannah A; Spliethoff, Henry M; Mitchell, Rebecca G; Marquez-Bravo, Lydia G; Ferenz, Gretchen S; Russell-Anelli, Jonathan M; Casey, Linda; Bachman, Sharon

2014-11-01

Paired vegetable/soil samples from New York City and Buffalo, NY, gardens were analyzed for lead (Pb), cadmium (Cd) and barium (Ba). Vegetable aluminum (Al) was measured to assess soil adherence. Soil and vegetable metal concentrations did not correlate; vegetable concentrations varied by crop type. Pb was below health-based guidance values (EU standards) in virtually all fruits. 47% of root crops and 9% of leafy greens exceeded guidance values; over half the vegetables exceeded the 95th percentile of market-basket concentrations for Pb. Vegetable Pb correlated with Al; soil particle adherence/incorporation was more important than Pb uptake via roots. Cd was similar to market-basket concentrations and below guidance values in nearly all samples. Vegetable Ba was much higher than Pb or Cd, although soil Ba was lower than soil Pb. The poor relationship between vegetable and soil metal concentrations is attributable to particulate contamination of vegetables and soil characteristics that influence phytoavailability. Copyright © 2014 Elsevier Ltd. All rights reserved.

Low Antigen Dose in Adjuvant-Based Vaccination Selectively Induces CD4 T Cells with Enhanced Functional Avidity and Protective Efficacy

PubMed Central

Wang, Yichuan; Solaymani-Mohammadi, Shahram; Frey, Blake; Kulkarni, Shweta; Andersen, Peter; Agger, Else Marie; Sui, Yongjun

2017-01-01

T cells with high functional avidity can sense and respond to low levels of cognate Ag, a characteristic that is associated with more potent responses against tumors and many infections, including HIV. Although an important determinant of T cell efficacy, it has proven difficult to selectively induce T cells of high functional avidity through vaccination. Attempts to induce high-avidity T cells by low-dose in vivo vaccination failed because this strategy simply gave no response. Instead, selective induction of high-avidity T cells has required in vitro culturing of specific T cells with low Ag concentrations. In this study, we combined low vaccine Ag doses with a novel potent cationic liposomal adjuvant, cationic adjuvant formulation 09, consisting of dimethyldioctadecylammonium liposomes incorporating two immunomodulators (monomycolyl glycerol analog and polyinosinic-polycytidylic acid) that efficiently induces CD4 Th cells, as well as cross-primes CD8 CTL responses. We show that vaccination with low Ag dose selectively primes CD4 T cells of higher functional avidity, whereas CD8 T cell functional avidity was unrelated to vaccine dose in mice. Importantly, CD4 T cells of higher functional avidity induced by low-dose vaccinations showed higher cytokine release per cell and lower inhibitory receptor expression (PD-1, CTLA-4, and the apoptosis-inducing Fas death receptor) compared with their lower-avidity CD4 counterparts. Notably, increased functional CD4 T cell avidity improved antiviral efficacy of CD8 T cells. These data suggest that potent adjuvants, such as cationic adjuvant formulation 09, render low-dose vaccination a feasible and promising approach for generating high-avidity T cells through vaccination. PMID:28348274

Partial reconstitution of the CD4+-T-cell compartment in CD4 gene knockout mice restores responses to tuberculosis DNA vaccines.

PubMed

D'Souza, Sushila; Romano, Marta; Korf, Johanna; Wang, Xiao-Ming; Adnet, Pierre-Yves; Huygen, Kris

2006-05-01

Reactivation tuberculosis (TB) is a serious problem in immunocompromised individuals, especially those with human immunodeficiency virus (HIV) coinfection. The adaptive immune response mediated by CD4+ and CD8+ T cells is known to confer protection against TB. Hence, vaccines against TB are designed to activate these two components of the immune system. Anti-TB DNA vaccines encoding the immunodominant proteins Ag85A, Ag85B, and PstS-3 from Mycobacterium tuberculosis are ineffective in mice lacking CD4+ T cells (CD4-/- mice). In this study, we demonstrate that reconstitution of the T-cell compartment in CD4-/- mice restores vaccine-specific antibody and gamma interferon (IFN-gamma) responses to these DNA vaccines. The magnitude of the immune responses correlated with the extent of reconstitution of the CD4+-T-cell compartment. Reconstituted mice vaccinated with DNA encoding PstS-3, known to encode a dominant D(b)-restricted CD8+-T-cell epitope, displayed CD8+-T-cell responses not observed in CD4-/- mice. M. tuberculosis challenge in reconstituted mice led to the extravasation of IFN-gamma-producing CD4+ and CD8+ T cells into lungs, the primary site of bacterial replication. Importantly, a reconstitution of 12 to 15% of the CD4+-T-cell compartment resulted in Ag85B plasmid DNA-mediated protection against a challenge M. tuberculosis infection. Our findings provide evidence that anti-TB DNA vaccines could be effective in immunodeficient individuals after CD4+-T-lymphocyte reconstitution, as may occur following antiretroviral therapy in HIV+ patients.

Copresentation of antigen and ligands of Siglec-G induces B cell tolerance independent of CD22.

PubMed

Pfrengle, Fabian; Macauley, Matthew S; Kawasaki, Norihito; Paulson, James C

2013-08-15

Differentiation of self from nonself is indispensable for maintaining B cell tolerance in peripheral tissues. CD22 and Siglec-G (sialic acid-binding Ig-like lectin G) are two inhibitory coreceptors of the BCR that are implicated in maintenance of tolerance to self Ags. Enforced ligation of CD22 and the BCR by a nanoparticle displaying both Ag and CD22 ligands induces a tolerogenic circuit resulting in apoptosis of the Ag-reactive B cell. Whether Siglec-G also has this property has not been investigated in large part owing to the lack of a selective Siglec-G ligand. In this article, we report the development of a selective high-affinity ligand for Siglec-G and its application as a chemical tool to investigate the tolerogenic potential of Siglec-G. We find that liposomal nanoparticles decorated with Ag and Siglec-G ligand inhibit BCR signaling in both B1 and B2 B cells compared with liposomes displaying Ag alone. Not only is inhibition of B cell activation observed by ligating the BCR with Siglec-G, but robust tolerance toward T-independent and T-dependent Ags is also induced in mice. The ability of Siglec-G to inhibit B cell activation equally in both B1 and B2 subsets is consistent with our observation that Siglec-G is expressed at a relatively constant level throughout numerous B cell subsets. These results suggest that Siglec-G may contribute to maintenance of B cell tolerance toward self Ags in various B cell compartments.

Preparation of high density heavy metal fluoride glasses with extended ultraviolet and infra red ranges, and such high density heavy metal fluoride glasses

NASA Technical Reports Server (NTRS)

Martin, Steven W. (Inventor); Huebsch, Jesse (Inventor)

2001-01-01

A heavy metal fluoride glass composition range (in mol percent) consisting essentially of: (16-30)BaF.sub.2.(8-26)HfF.sub.4.(6-24)InF.sub.3 or GaF.sub.3.(4-16)CdF.sub.2.(6-24)YbF.sub.3.(4-22)ZnF.sub.2. In an alternative embodiment, a heavy metal fluoride glass composition range (in mol percent) comprises (16-30)BaF.sub.2.(8-26)HfF.sub.4.(6-24) of (0-24)InF.sub.3, (0-24)GaF.sub.3 and (0-19)AlF.sub.3.(1-16)CdF.sub.2.(6-24)YbF.sub.3.(4-26)ZnF.sub.2. A preferred heavy metal fluoride glass produced in accordance with the present invention comprises a composition (in mol %) and comprises about 26BaF.sub.2.18HfF.sub.4.7InF.sub.3.5GaF.sub.3.10CdF.sub.2.18YbF.sub.3. 16ZnF.sub.2. A preferred heavy metal fluoride glass has maximum thickness of most preferably about 3 mm. Another preferred heavy metal fluoride glass comprises a composition (in mol %) and comprises about 26BaF.sub.2.18HfF.sub.4.12AlF.sub.3.10CdF.sub.2.18YbF.sub.3.16ZnF.sub.2.

Solid phase extraction of trace amounts of Ag, Cd, Cu, and Zn in environmental samples using magnetic nanoparticles coated by 3-(trimethoxysilyl)-1-propantiol and modified with 2-amino-5-mercapto-1,3,4-thiadiazole and their determination by ICP-OES.

PubMed

Mashhadizadeh, Mohammad Hossein; Karami, Zahra

2011-06-15

A fast, sensitive, and simple method using magnetic nanoparticles (MNPs) coated by 3-(trimethoxysilyl)-1-propantiol and modified with 2-amino-5-mercapto-1,3,4-thiadiazole, as an adsorbent has been successfully developed for extraction, preconcentration, and determination of trace amounts of Ag, Cd, Cu, and Zn from environmental samples. The prepared nanoparticles were characterized by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). These magnetic nanoparticles can be easily dispersed in aqueous samples and retrieved by the application of external magnetic field via a piece of permanent magnet. The main factors affecting the extraction efficiency such as pH value, sample volume, eluent concentration and volume, ultrasonication time, and coexisting ions have been investigated and established. Under the optimal conditions, high concentration factors (194, 190, 170, and 182) were achieved for Ag, Cd, Cu, and Zn with relative standard deviations of 5.31%, 4.03%, 3.62%, and 4.20%, respectively. The limits of detection for Ag, Cd, Cu, and Zn were as low as 0.12, 0.12, 0.13 and 0.11 ng mL(-1). The prepared sorbent was applied for preconcentration of trace amounts of Ag, Cd, Cu, and Zn in the various water samples with satisfactory results. Copyright © 2011 Elsevier B.V. All rights reserved.

The successful incorporation of Ag into single grain, Y-Ba-Cu-O bulk superconductors

NASA Astrophysics Data System (ADS)

Congreve, Jasmin V. J.; Shi, Yunhua; Dennis, Anthony R.; Durrell, John H.; Cardwell, David A.

2018-07-01

The use of RE-Ba-Cu-O [(RE)BCO] bulk superconductors, where RE = Y, Gd, Sm, in practical applications is, at least in part, limited by their mechanical properties and brittle nature, in particular. Alloying these materials with silver, however, produces a significant improvement in strength without any detrimental impact on their superconducting properties. Unfortunately, the top seeded melt growth technique, used routinely to process bulk (RE)BCO superconductors in the form of large, single grains required for practical applications, is complex and has a large number of inter-related variables, so the addition of silver increases the complexity of the growth process even further. This can make successful growth of this system extremely challenging. Here we report measurements of the growth rate of YBCO-Ag fabricated using a new growth technique consisting of continuous cooling and isothermal hold process. The resulting data form the basis of a model that has been used to derive suitable heating profiles for the successful single grain growth of YBCO-Ag bulk superconductors of up to 26 mm in diameter. The microstructure and distribution of silver within these samples have been studied in detail. The maximum trapped field at the top surface of the bulk YBCO-Ag samples has been found to be comparable to that of standard YBCO processed without Ag. The YBCO-Ag samples also exhibit a much more uniform trapped field profile compared to that of YBCO.

LONG-TERM OUTCOME OF THE DIFFERENT TREATMENT ALTERNATIVES FOR RECURRENT AND PERSISTENT CUSHING DISEASE.

PubMed

Espinosa-de-Los-Monteros, Ana Laura; Sosa-Eroza, Ernesto; Espinosa, Etual; Mendoza, Victoria; Arreola, Rocio; Mercado, Moises

2017-07-01

Treatment alternatives for persistent and recurrent Cushing disease (CD) include pituitary surgical re-intervention, radiation therapy (RT), pharmacotherapy, and bilateral adrenalectomy (BA). The decision of which of these alternatives is better suited for the individual patient rests on clinical judgment and the availability of resources. This retrospective cohort study was performed at a referral center to evaluate the long-term efficacy of different secondary interventions for persistent and recurrent CD. We evaluated the hospital charts of 84 patients (77 female, median age 34 years, median follow up 6.3 years) with CD diagnosed, treated, and followed at our multidisciplinary clinic according to a pre-established protocol. Of the 81 patients who were initially treated with transsphenoidal surgery (TSS), 61.7% had a long-lasting remission, 16% had persistent disease, and 22% achieved remission but relapsed during follow-up. The most frequently used secondary treatment was pituitary re-intervention, followed by ketoconazole, RT, and BA. Early remissions were observed in 66.6% of the re-operated and in 58.3% of the radiated patients; long-lasting remission was achieved in 33.3% and 41.6% of these patients, respectively. Nelson syndrome developed in 41.6% of the patients who underwent BA. Upon last follow-up, 88% of all the patients are in remission, and 9.5% are biochemically controlled with ketoconazole. The efficacy of treatment alternatives for recurrent or persistent CD varies considerably among patients and multiple interventions are often required to achieve long-lasting remission. ACTH = adrenocorticotrophic hormone; BA = bilateral adrenalectomy; CBG = cabergoline; CD = Cushing disease; CV = coefficient of variation; DXM = dexamethasone; IQR = interquartile range; RT = radiation therapy; SRS = stereotactic radiosurgery; TSS = transsphenoidal surgery; UFC = urinary free cortisol; ULN = upper limit of normal.

Selectively Reduced Intracellular Proliferation of Salmonella enterica Serovar Typhimurium within APCs Limits Antigen Presentation and Development of a Rapid CD8 T Cell Response1

PubMed Central

Albaghdadi, Homam; Robinson, Nirmal; Finlay, Brett; Krishnan, Lakshmi; Sad, Subash

2014-01-01

Ag presentation to CD8+ T cells commences immediately after infection, which facilitates their rapid expansion and control of pathogen. This paradigm is not followed during infection with virulent Salmonella enterica serovar Typhimurium (ST), an intracellular bacterium that causes mortality in susceptible C57BL/6J mice within 7 days and a chronic infection in resistant mice (129 × 1SvJ). Infection of mice with OVA-expressing ST results in the development of a CD8+ T cell response that is detectable only after the second week of infection despite the early detectable bacterial burden. The mechanism behind the delayed CD8+ T cell activation was evaluated, and it was found that dendritic cells/macrophages or mice infected with ST-OVA failed to present Ag to OVA-specific CD8+ T cells. Lack of early Ag presentation was not rescued when mice or dendritic cells/macrophages were infected with an attenuated aroA mutant of ST or with mutants having defective Salmonella pathogenicity island I/II genes. Although extracellular ST proliferated extensively, the replication of ST was highly muted once inside macrophages. This muted intracellular proliferation of ST resulted in the generation of poor levels of intracellular Ag and peptide-MHC complex on the surface of dendritic cells. Additional experiments revealed that ST did not actively inhibit Ag presentation, rather it inhibited the uptake of another intracellular pathogen, Listeria monocytogenes, thereby causing inhibition of Ag presentation against L. monocytogenes. Taken together, this study reveals a dichotomy in the proliferation of ST and indicates that selectively reduced intra-cellular proliferation of virulent pathogens may be an important mechanism of immune evasion. PMID:19692639

Artificial neural networks for the diagnosis of aggressive periodontitis trained by immunologic parameters.

PubMed

Papantonopoulos, Georgios; Takahashi, Keiso; Bountis, Tasos; Loos, Bruno G

2014-01-01

There is neither a single clinical, microbiological, histopathological or genetic test, nor combinations of them, to discriminate aggressive periodontitis (AgP) from chronic periodontitis (CP) patients. We aimed to estimate probability density functions of clinical and immunologic datasets derived from periodontitis patients and construct artificial neural networks (ANNs) to correctly classify patients into AgP or CP class. The fit of probability distributions on the datasets was tested by the Akaike information criterion (AIC). ANNs were trained by cross entropy (CE) values estimated between probabilities of showing certain levels of immunologic parameters and a reference mode probability proposed by kernel density estimation (KDE). The weight decay regularization parameter of the ANNs was determined by 10-fold cross-validation. Possible evidence for 2 clusters of patients on cross-sectional and longitudinal bone loss measurements were revealed by KDE. Two to 7 clusters were shown on datasets of CD4/CD8 ratio, CD3, monocyte, eosinophil, neutrophil and lymphocyte counts, IL-1, IL-2, IL-4, INF-γ and TNF-α level from monocytes, antibody levels against A. actinomycetemcomitans (A.a.) and P.gingivalis (P.g.). ANNs gave 90%-98% accuracy in classifying patients into either AgP or CP. The best overall prediction was given by an ANN with CE of monocyte, eosinophil, neutrophil counts and CD4/CD8 ratio as inputs. ANNs can be powerful in classifying periodontitis patients into AgP or CP, when fed by CE values based on KDE. Therefore ANNs can be employed for accurate diagnosis of AgP or CP by using relatively simple and conveniently obtained parameters, like leukocyte counts in peripheral blood. This will allow clinicians to better adapt specific treatment protocols for their AgP and CP patients.

Polymorphism in endothelin-related genes limits exercise-induced decreases in arterial stiffness in older subjects.

PubMed

Iemitsu, Motoyuki; Maeda, Seiji; Otsuki, Takeshi; Sugawara, Jun; Tanabe, Takumi; Jesmin, Subrina; Kuno, Shinya; Ajisaka, Ryuichi; Miyauchi, Takashi; Matsuda, Mitsuo

2006-05-01

Increase in arterial stiffness is associated with aging, which is improved by regular exercise. Endothelin (ET) system has crucial roles in regulating vascular tone and in the progression of atherosclerosis. We hypothesized that molecular variations (ie, gene polymorphisms) in ET-related gene might affect exercise-induced improvement in arterial stiffness with age in human subjects. The present study provides a cross-sectional investigation of 191 healthy middle-aged and older (65+/-1 years) human subjects to clarify the relationship between the regular exercise-induced improvement of arterial stiffness and the gene polymorphisms of ET converting enzyme (ECE)-1, ECE-2, ET-A receptor (ET-A), and ET-B receptor (ET-B). The study subjects were divided into active and inactive groups based on the median value (186 kcal/d) of energy expenditure. Brachial-ankle arterial pulse wave velocity (baPWV) was used to evaluate arterial stiffness. All individuals were genotyped for 4 different polymorphisms of the ET system: 2013(+289)A/G in intron 17 of ECE-1, 669(+17)T/C in intron 5 of ECE-2, 958A/G in exon 6 of ET-A, and 831A/G in exon 4 of ET-B. The baseline baPWV was significantly lower in the active group without any change in blood pressure. Polymorphisms in ECE-1 influenced basal blood pressure. Polymorphisms in ECE-1 and ECE-2 had no effect on baPWV between active and inactive groups. However, polymorphisms in both ET-A and ET-B affected baPWV in the 2 groups. The present results suggest that differences in ET-A and ET-B polymorphisms may influence the response of the vascular wall to exercise whereas ECE-1 polymorphisms may affect basal blood pressure.

Fenton-like Degradation of Phenol Catalyzed by a Series of Fe-Containing Mixed Oxides Systems

NASA Astrophysics Data System (ADS)

Alhmoud, T. T.; Mahmoud, S. S.; Hammoudeh, A. Y.

2018-02-01

In our attempts to develop a solid catalyst to degrade organic pollutants in wastewater via the Fenton-like reaction, six Fe-containing mixed oxide systems were prepared by means of the sol-gel auto-combustion method to have the following stoichiometries: CuFe1.2O2.8, BaFe7.2O11.8, BaFe7.2Cu2O13.8, BaFe5.4V3O16.6, BaFe4.8Cu2V3O17.7 and Ag2Fe5.4V3O16.6. The prepared systems were thermally treated at 550°C, 650°C, 800°C and 1100°C, and then characterized by XRD to identify the present phases. The systems were tested with respect to their catalytic efficiency in the degradation of phenol (200 ppm) in water where CuFe1.2O2.8 was found to be the most reactive one (80% removal in 60 min). It showed thereby first-order kinetics and an enhanced behavior under irradiation with a 30-W LED light source. The positive role of irradiation was most obvious in the case of Ag2Fe5.4V3O16.6 in which almost complete conversion was achieved in 120 min compared to only 45% in the same period but without irradiation. However, increasing the temperature at which thermal treatment is performed was found to suppress the catalytic activity of the system. Due to their high efficiency and rather low leaching rates of constituents, CuFe1.2O2.8 or Ag2Fe5.4V3O16.6 seem to be very promising in the Fenton-like degradation of organic pollutants.

Peptidases released by necrotic cells control CD8+ T cell cross-priming

PubMed Central

Gamrekelashvili, Jaba; Kapanadze, Tamar; Han, Miaojun; Wissing, Josef; Ma, Chi; Jaensch, Lothar; Manns, Michael P.; Armstrong, Todd; Jaffee, Elizabeth; White, Ayla O.; Citrin, Deborah E.; Korangy, Firouzeh; Greten, Tim F.

2013-01-01

Cross-priming of CD8+ T cells and generation of effector immune responses is pivotal for tumor immunity as well as for successful anticancer vaccination and therapy. Dead and dying cells produce signals that can influence Ag processing and presentation; however, there is conflicting evidence regarding the immunogenicity of necrotic cell death. We used a mouse model of sterile necrosis, in which mice were injected with sterile primary necrotic cells, to investigate a role of these cells in priming of CD8+ T cells. We discovered a molecular mechanism operating in Ag donor cells that regulates cross-priming of CD8+ T cells during primary sterile necrosis and thereby controls adaptive immune responses. We found that the cellular peptidases dipeptidyl peptidase 3 (DPP-3) and thimet oligopeptidase 1 (TOP-1), both of which are present in nonimmunogenic necrotic cells, eliminated proteasomal degradation products and blocked Ag cross-presentation. While sterile necrotic tumor cells failed to induce CD8+ T cell responses, their nonimmunogenicity could be reversed in vitro and in vivo by inactivation of DPP-3 and TOP-1. These results indicate that control of cross-priming and thereby immunogenicity of primary sterile necrosis relies on proteasome-dependent oligopeptide generation and functional status of peptidases in Ag donor cells. PMID:24216478

Peptidases released by necrotic cells control CD8+ T cell cross-priming.

PubMed

Gamrekelashvili, Jaba; Kapanadze, Tamar; Han, Miaojun; Wissing, Josef; Ma, Chi; Jaensch, Lothar; Manns, Michael P; Armstrong, Todd; Jaffee, Elizabeth; White, Ayla O; Citrin, Deborah E; Korangy, Firouzeh; Greten, Tim F

2013-11-01

Cross-priming of CD8+ T cells and generation of effector immune responses is pivotal for tumor immunity as well as for successful anticancer vaccination and therapy. Dead and dying cells produce signals that can influence Ag processing and presentation; however, there is conflicting evidence regarding the immunogenicity of necrotic cell death. We used a mouse model of sterile necrosis, in which mice were injected with sterile primary necrotic cells, to investigate a role of these cells in priming of CD8+ T cells. We discovered a molecular mechanism operating in Ag donor cells that regulates cross-priming of CD8+ T cells during primary sterile necrosis and thereby controls adaptive immune responses. We found that the cellular peptidases dipeptidyl peptidase 3 (DPP-3) and thimet oligopeptidase 1 (TOP-1), both of which are present in nonimmunogenic necrotic cells, eliminated proteasomal degradation products and blocked Ag cross-presentation. While sterile necrotic tumor cells failed to induce CD8+ T cell responses, their nonimmunogenicity could be reversed in vitro and in vivo by inactivation of DPP-3 and TOP-1. These results indicate that control of cross-priming and thereby immunogenicity of primary sterile necrosis relies on proteasome-dependent oligopeptide generation and functional status of peptidases in Ag donor cells.

RTS,S/AS01E Malaria Vaccine Induces Memory and Polyfunctional T Cell Responses in a Pediatric African Phase III Trial.

PubMed

Moncunill, Gemma; De Rosa, Stephen C; Ayestaran, Aintzane; Nhabomba, Augusto J; Mpina, Maximillian; Cohen, Kristen W; Jairoce, Chenjerai; Rutishauser, Tobias; Campo, Joseph J; Harezlak, Jaroslaw; Sanz, Héctor; Díez-Padrisa, Núria; Williams, Nana Aba; Morris, Daryl; Aponte, John J; Valim, Clarissa; Daubenberger, Claudia; Dobaño, Carlota; McElrath, M Juliana

2017-01-01

Comprehensive assessment of cellular responses to the RTS,S/AS01E vaccine is needed to understand potential correlates and ultimately mechanisms of protection against malaria disease. Cellular responses recognizing the RTS,S/AS01E-containing circumsporozoite protein (CSP) and Hepatitis B surface antigen (HBsAg) were assessed before and 1 month after primary vaccination by intracellular cytokine staining and 16-color flow cytometry in 105 RTS,S/AS01-vaccinated and 74 rabies-vaccinated participants (controls) in a pediatric phase III trial in Africa. RTS,S/AS01E-vaccinated children had significantly higher frequencies of CSP- and HBsAg-specific CD4 + T cells producing IL-2, TNF-α, and CD40L and HBsAg-specific CD4 + T producing IFN-γ and IL-17 than baseline and the control group. Vaccine-induced responses were identified in both central and effector memory (EM) compartments. EM CD4 + T cells expressing IL-4 and IL-21 were detected recognizing both vaccine antigens. Consistently higher response rates to both antigens in RTS,S/AS01E-vaccinated than comparator-vaccinated children were observed. RTS,S/AS01E induced polyfunctional CSP- and HBsAg-specific CD4 + T cells, with a greater degree of polyfunctionality in HBsAg responses. In conclusion, RTS,S/AS01E vaccine induces T cells of higher functional heterogeneity and polyfunctionality than previously characterized. Responses detected in memory CD4 + T cell compartments may provide correlates of RTS,S/AS01-induced immunity and duration of protection in future correlates of immunity studies.

Endothelial microparticles interact with and support the proliferation of T cells.

PubMed

Wheway, Julie; Latham, Sharissa L; Combes, Valery; Grau, Georges E R

2014-10-01

Endothelial cells closely interact with circulating lymphocytes. Aggression or activation of the endothelium leads to an increased shedding of endothelial cell microparticles (MP). Endothelial MP (EMP) are found in high plasma levels in numerous immunoinflammatory diseases, such as atherosclerosis, sepsis, multiple sclerosis, and cerebral malaria, supporting their role as effectors and markers of vascular dysfunction. Given our recently described role for human brain microvascular endothelial cells (HBEC) in modulating immune responses, we investigated how HBEC-derived MP could interact with and support the proliferation of T cells. Like their mother cells, EMP expressed molecules important for Ag presentation and T cell costimulation, that is, β2-microglobulin, MHC II, CD40, and ICOSL. HBEC were able to take up fluorescently labeled Ags with EMP also containing fluorescent Ags, suggestive of Ag carryover from HBEC to EMP. In cocultures, fluorescently labeled EMP from resting or cytokine-stimulated HBEC formed conjugates with both CD4(+) and CD8(+) subsets, with higher proportions of T cells binding EMP from cytokine-stimulated cells. The increased binding of EMP from cytokinestimulated HBEC to T cells was VCAM-1 and ICAM-1 dependent. Finally, in CFSE T cell proliferation assays using anti-CD3 mAb or T cell mitogens, EMP promoted the proliferation of CD4(+) T cells and that of CD8(+) T cells in the absence of exogenous stimuli and in the T cell mitogenic stimulation. Our findings provide novel evidence that EMP can enhance T cell activation and potentially ensuing Ag presentation, thereby pointing toward a novel role for MP in neuroimmunological complications of infectious diseases. Copyright © 2014 by The American Association of Immunologists, Inc.

Associations between CD36 gene polymorphisms and susceptibility to coronary artery heart disease

PubMed Central

Zhang, Y.; Ling, Z.Y.; Deng, S.B.; Du, H.A.; Yin, Y.H.; Yuan, J.; She, Q.; Chen, Y.Q.

2014-01-01

Associations between polymorphisms of the CD36 gene and susceptibility to coronary artery heart disease (CHD) are not clear. We assessed allele frequencies and genotype distributions of CD36 gene polymorphisms in 112 CHD patients and 129 control patients using semi-quantitative polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. Additionally, we detected CD36 mRNA expression by real-time quantitative PCR, and we quantified plasma levels of oxidized low-density lipoprotein (ox-LDL) using an enzyme-linked immunosorbent assay (ELISA). There were no significant differences between the two groups (P>0.05) in allele frequencies of rs1761667 or in genotype distribution and allele frequencies of rs3173798. The genotype distribution of rs1761667 significantly differed between CHD patients and controls (P=0.034), with a significantly higher frequency of the AG genotype in the CHD group compared to the control group (P=0.011). The plasma levels of ox-LDL in patients with the AG genotype were remarkably higher than those with the GG and AA genotypes (P=0.010). In a randomized sample taken from patients in the two groups, the CD36 mRNA expression of the CHD patients was higher than that of the controls. In CHD patients, the CD36 mRNA expression in AG genotype patients was remarkably higher than in those with an AA genotype (P=0.005). After adjusted logistic regression analysis, the AG genotype of rs1761667 was associated with an increased risk of CHD (OR=2.337, 95% CI=1.336-4.087, P=0.003). In conclusion, the rs1761667 polymorphism may be closely associated with developing CHD in the Chongqing Han population of China, and an AG genotype may be a genetic susceptibility factor for CHD. PMID:25118627

A comparative study of the effect of α-, β-, and γ-cyclodextrins as stabilizing agents in the synthesis of silver nanoparticles using a green chemistry method.

PubMed

Suárez-Cerda, Javier; Nuñez, Gabriel Alonso; Espinoza-Gómez, Heriberto; Flores-López, Lucía Z

2014-10-01

This paper describes the effect of different types of cyclodextrins (CDs) in the synthesis of silver nanoparticles (Ag-NPs), using an easy green chemistry method. The Ag-NPs were obtained using an aqueous silver nitrate solution (AgNO3) with α-, β-, or γ-CDs (aqueous solutions) as stabilizing agents, employing the chemical reduction method with citric acid as a reducing agent. A comparative study was done to determine which cyclodextrin (CD) was the best stabilizing agent, and we found out that β-CD was the best due to the number of glucopyranose units in its structure. The formation of the Ag-NPs was demonstrated by analysis of UV-vis spectroscopy, atomic force microscopy (AFM), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and transmission electron microscopy (TEM). SEM-EDS showed the formation of a cluster with a significant amount of silver, for β-CD-Ag-NPs, spherical agglomerates can be observed. However, for α-, γ-CD, the agglomerates do not have a specific form, but their appearance is porous. TEM analysis shows spherical nanoparticles in shape and size between ~0.5 to 7 nm. The clear lattice fringes in TEM images and the typical selected area electron diffraction (SAED) pattern, showed that the Ag-NPs obtained were highly crystalline with a face cubic center structure (FCC). Copyright © 2014 Elsevier B.V. All rights reserved.

Phytoextraction of metals by Erigeron canadensis L. from fly ash landfill of power plant "Kolubara".

PubMed

Krgović, Rada; Trifković, Jelena; Milojković-Opsenica, Dušanka; Manojlović, Dragan; Marković, Marijana; Mutić, Jelena

2015-07-01

The objectives of this study were to determine the concentrations of Pb, Cd, As, Cr, Cu, Co, Ni, Zn, Ba, Fe, Al and Ag in Erigeron canadensis L. growing on fly ash landfill of power plant "Kolubara", Serbia. The content of each element was determined in every part of plant separately (root, stalk and inflorescence) and correlated with the content of elements in each phase of sequential extraction of fly ash. In order to ambiguously select the factors that are able to decidedly characterize the particular part of plant, principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were performed. The bioconcentration factors and translocation factors for each metal were calculated in order to determine the feasibility of the use of plant E. canadensis L. for phytoremediation purpose. There were strong positive correlations between metals in every part of plant samples, and metals from pseudo total form of sequential extraction indicate that the bioavailability of elements in fly ash is similarly correlated with total form. Retained Al, Fe, Cr and Co in the root indicate its suitability for phytostabilization. This plant takes up Cd and Zn from the soil (bioconcentration factors (BCFs) greater than 1), transporting them through the stalk into the inflorescence (translocation factors (TFs) higher than 1). Regarding its dominance in vegetation cover and abundance, E. canadensis L. can be considered adequate for phytoextraction of Cd and Zn from coal ash landfills at Kolubara.

Reactivity and oxygen diffusion property of resistive barriers for Bi-2223/Ag tapes

NASA Astrophysics Data System (ADS)

Kováč, P.; Hušek, I.

2002-12-01

Reactivity of several oxide materials (OM) with BSCCO powder and oxygen diffusion through OM layer has been tested at temperature ≈840 °C in air. The OM (e.g.: BaZrO 3, SrCO 3, MgO and ZrO 2) showing the low or no reactivity with BSCCO have been mixed (10 wt.%) with precursor powder and used for single-core tapes. Bi-2223/Ag/OM/Ag single-core tapes with oxide barriers made of BaZrO 3, SrCO 3, ZrO 2 and Al 2O 3 have been also prepared by a standard powder-in-tube technique. The used OM in the direct contact with BSCCO influences the electrical properties of Bi-2223 phase differently. These is because the oxides react with BSCCO during the heat treatment and simultaneously affect the 2212→2223 phase transformation, the Bi-2223 grain growth and so also grain connectivity. SrCO 3 powder has been evaluated as the best material from the point of no destructive effect on 2223 phase transport current property. The oxide barrier controls the oxygen diffusion during the tape heat treatment and simultaneously the HTS phase formation kinetics, its purity and content within the superconducting core. For single-core Bi-2223/Ag/OM/Ag tapes, the highest current density was measured for Al 2O 3 due to only slightly reduced oxygen diffusion through the barrier.

Persistent magnetism in silver-doped BaF e 2 A s 2 crystals

DOE PAGES

Li, Li; Cao, Huibo; Parker, David S.; ...

2016-10-12

Here, we investigate the thermodynamic and transport properties of silver-substituted BaF e 2 A s 2 (122) crystals up to ~ 4.5 % . Similar to other transition-metal substitutions in 122, Ag diminishes the antiferromagnetic ( T N ) and structural ( T S ) transition temperatures, but unlike other electron-doped 122s, T N and T S coincide without splitting. Though magnetism drops precipitously to T N = 84 K at doping x = 0.029 , it only weakly changes above this x , settling at T N = 80 K at x = 0.045 . Compared to this persistentmore » magnetism in Ag-122, doping other group 11 elements of either Cu or Au in 122 diminished T N and induced superconductivity near T c = 2 K at x = 0.044 or 0.031, respectively. Ag-122 crystals show reflective surfaces with surprising thicker cross sections for x ≥ 0.019 , the appearance that is in contrast to the typical thin stacked layered feature seen in all other flux-grown x-122 and lower Ag-122. We found that this physical trait may be a manifest of intrinsic weak changes in c lattice and T N . Our theoretical calculations suggest that Ag doping produces strong electronic scattering and yet a relatively small disruption of the magnetic state, both of which preclude superconductivity in this system.« less

Single domain YBa2Cu3Oy thick films on metallic substrates

NASA Astrophysics Data System (ADS)

Reddy, E. S.; Noudem, J. G.; Goodilin, E. A.; Tarka, M.; Schmitz, G. J.

2003-03-01

The fabrication of single domain YBa2Cu3Oy (123) thick films (10-100 mum) on metallic substrates is reported. The process involves the formation of the 123 phase by a peritectic reaction between an air-brushed dense Y2BaCuO5 (211) layer on a Ag12Pd substrate and infiltrated liquid phases containing barium cuprates and copper oxides. Single domain growth is achieved by seeding the green films with a c-axis oriented NdBa2Cu3Oy crystal prior to processing. The maximum processing temperatures are lowered to 970 °C by modifying the characteristics of the liquid phases meant for infiltration by addition of Ag powder. The fabrication technique, processing conditions for single domain growth and the resulting microstructures are discussed.

Biomonitoring of 30 trace elements in urine of children and adults by ICP-MS.

PubMed

Heitland, Peter; Köster, Helmut D

2006-03-01

The paper provides physicians and clinical chemists with statistical data (concentration ranges, geometric mean values, selected percentiles, etc.) about 30 urinary trace elements in order to determine whether people have trace element deficiencies or have been exposed to higher elemental concentrations. Morning urine samples of 72 children and 87 adults from two geographical areas of Germany were collected and the elements Li, Be, V, Cr, Mn, Ni, Co, Cu, Zn, Ga, As, Se, Rb, Sr, Mo, Rh, Pd, Ag, Cd, In, Sn, Sb, Cs, Ba, Pt, Au, Pb, Tl, Bi and U were determined by inductively coupled plasma mass spectrometry (ICP-MS) with a new octopole based collision/reaction cell. The urine samples were analysed directly after a simple 1/5 (V/V) dilution with deionised water and nitric acid. Information on exposure conditions of all human subjects were collected by questionnaire-based interviews. The described concentration data down to the ng/l range are very useful for the formulation of reference values. For some elements either new data are described (e.g., for V, Ga, In, Bi, Rh, Mn) or differences to earlier studies were found (e.g., for Be, As). For other elements (e.g., Sb, Se, Mo, Ba, Cu, Zn, Li) our results are in good correlation with previous studies and also complemented with urinary trace element concentrations for children.

A placebo controlled observer blind immunocytochemical and histologic study of epithelium adjacent to anogenital warts in patients treated with systemic interferon alpha in combination with cryotherapy or cryotherapy alone.

PubMed Central

Handley, J M; Maw, R D; Horner, T; Lawther, H; Walsh, M; Dinsmore, W W

1992-01-01

OBJECTIVE--To examine biopsy specimens of tissue immediately adjacent to anogenital (AG) warts which had been treated with either cryotherapy plus subcutaneous interferon (IFN) alpha 2a or cryotherapy alone, for histological features of (a) human papilloma virus (HPV) infection (b) localised cellular immune responses, to further characterise any cellular immune infiltrates with tissue immunocytochemistry, and to relate any histological, immunocytochemical findings to the treatment response of nearby AG warts. DESIGN--A randomised placebo controlled observer blind study. SETTING--Genitourinary Medicine clinic, Department of Immunopathology, Royal Victoria Hospital, Belfast, N. Ireland. SUBJECTS--Thirty patients with AG warts; 16 treated with IFN alpha 2a plus cryotherapy, and 14 treated with cryotherapy alone. OUTCOME MEASURES--(1) Light microscopic features associated with HPV infection and local cellular immune responses. (2) Indirect immunofluorescence detection of the following cell surface markers: HLA DR, alpha one antitrypsin, CD1, CD3, CD4, CD8, CD22. (3) Clinical response of AG warts to treatment. RESULTS--In pre-treatment biopsies only non specific indicators of HPV infection (acanthosis, 29/30 biopsies, and hyperkeratosis, 7/30 biopsies) were seen on light microscopy. Mononuclear cells were seen both throughout the upper dermis and centred around dermal blood vessels in 19/30 (63.3%) biopsies, and infiltrating into the epidermis in 12/30 (40%) biopsies. On indirect immunofluorescence CD3, CD8, CD4 antigen was detected on the surface of cells throughout the upper dermis in 24/29 (82.7%), 15/29 (51.7%), and 3/29 (10.3%), of biopsy specimens respectively. CD3 antigen, CD8 antigen and CD4 antigen was detected on the surface of cells infiltrating into the epidermis in 18/29 (62%), 7/29 (24.1%), and 6/29 (20.7%) of biopsy specimens respectively. CD1 antigen was seen on the surface of dendritic cells throughout the epidermis in all specimens; CD1 positive cells infiltrated into the upper dermis in 5/29 (17.2%). HLA DR was detected on the surface of dendritic cells throughout the epidermis in 22/29 (75.9%) of specimens, and on the surface of cells scattered both diffusely throughout the upper dermis and centred around dermal blood vessels in all specimens. Alpha one antitrypsin (A1AT) antigen was seen on the surface of cells in the upper dermis in 6/29 (20.7%) of biopsy specimens; no cells expressing CD22 surface antigen were seen. The nature of this local cellular immune response was not altered by treatment of nearby warts with either cryotherapy alone or cryotherapy plus systemic IFN alpha 2a, or related to the therapeutic outcome of these warts. CONCLUSIONS--(1) No convincing histological evidence of HPV infection was seen in epithelium surrounding AG warts. (2) A predominantly T cell-mediated immune response (the target of which is uncertain) was seen in this perilesional epithelium. (3) In the dosage regimens used in this study, treatment of AG warts with either systemic IFN alpha 2a plus cryotherapy or cryotherapy alone did not appear to augment localised cellular immune responses (against any presumed subclinical HPV infection) in epithelium surrounding AG warts. Images PMID:1316307

Surface LAMP-2 Is an Endocytic Receptor That Diverts Antigen Internalized by Human Dendritic Cells into Highly Immunogenic Exosomes.

PubMed

Leone, Dario Armando; Peschel, Andrea; Brown, Markus; Schachner, Helga; Ball, Miriam J; Gyuraszova, Marianna; Salzer-Muhar, Ulrike; Fukuda, Minoru; Vizzardelli, Caterina; Bohle, Barbara; Rees, Andrew J; Kain, Renate

2017-07-15

The lysosome-associated membrane protein (LAMP) family includes the dendritic cell endocytic receptors DC-LAMP and CD68, as well as LAMP-1 and LAMP-2. In this study we identify LAMP-1 (CD107a) and LAMP-2 (CD107b) on the surface of human monocyte-derived dendritic cells (MoDC) and show only LAMP-2 is internalized after ligation by specific Abs, including H4B4, and traffics rapidly but transiently to the MHC class II loading compartment, as does Ag conjugated to H4B4. However, pulsing MoDC with conjugates of primary (keyhole limpet hemocyanin; KLH) and recall (Bet v 1) Ags (H4B4*KLH and H4B4*Bet v 1) induced significantly less CD4 cell proliferation than pulsing with native Ag or Ag conjugated to control mAb (ISO*KLH and ISO*Bet v 1). In H4B4*KLH-pulsed MoDC, the duration of KLH residence in MHC class II loading compartments was significantly reduced, as were surface HLA-DR and DR-bound KLH-derived peptides. Paradoxically, MoDC pulsed with H4B4*KLH, but not the other KLH preparations, induced robust proliferation of CD4 cells separated from them by a transwell membrane, indicating factors in the supernatant were responsible. Furthermore, extracellular vesicles from supernatants of H4B4*KLH-pulsed MoDC contained significantly more HLA-DR and KLH than those purified from control MoDC, and KLH was concentrated specifically in exosomes that were a uniquely effective source of Ag in standard T cell proliferation assays. In summary, we identify LAMP-2 as an endocytic receptor on human MoDC that routes cargo into unusual Ag processing pathways, which reduces surface expression of Ag-derived peptides while selectively enriching Ag within immunogenic exosomes. This novel pathway has implications for the initiation of immune responses both locally and at distant sites. Copyright © 2017 by The American Association of Immunologists, Inc.

Contents of Ag and other metals in food-contact plastics with nanosilver or Ag ion and their migration into food simulants.

PubMed

Ozaki, Asako; Kishi, Eri; Ooshima, Tomoko; Hase, Atsushi; Kawamura, Yoko

2016-09-01

Six nanosilver-labelled products and five silver ion (Ag(+))-labelled products were investigated to measure the migration of Ag from food-contact plastics, including nanosilver into various food simulants. The products were obtained in Japanese markets in 2012. Zinc (Zn), another major antimicrobial agent, and three harmful metals, cadmium (Cd), lead (Pb) and arsenic (As), were also examined. Ag and Zn were detected in all six nanosilver products at concentrations of 21-200 and 8.4-140 mg kg(-1), respectively. These metals were also detected in all five Ag(+) products at the same level as nanosilver products. Cd, Pb and As were not detected in any sample. Migrations of Ag and Zn were highest in 4% acetic acid, but also observed in water and 20% ethanol. Big differences were not observed in the migration ratio between nanosilver products and Ag(+) products. The ultrafiltration experiments suggested that the Ag that migrated from nanosilver products into 4% acetic acid was in its ionic form, while that into water and 20% ethanol was in its nanoparticle form.

Role of polymer matrix on photo-sensitivity of CdSe polymer nanocomposites

NASA Astrophysics Data System (ADS)

Kaur, Ramneek; Tripathi, S. K.

2018-04-01

This paper reports the effect of three different polymer matrices (PVP, PMMA and PVK) and Ag doping on the photo-sensitivity of CdSe polymer nanocomposites. The results reveal that the photoconductivity is high for linear chain polymer nanocomposites as compared to aromatic ones with decreasing trend as: CdSe-PMMA > CdSe-PVP > CdSe-PVK. The large substituents or branches along the polymer backbone hinder the stacking sequences in CdSe-PVK nanocomposites resulting in lowest photoconductivity. On contrary, CdSe-PVK nanocomposite exhibit highest photosensitivity. The reason behind it is the low value of dark conductivity in CdSe-PVK nanocomposite and photoconductive PVK matrix. With Ag doping, no considerable effect on the value of photosensitivity has been observed. The obtained results indicate that the photo-conducting properties of these polymer nanocomposites can be tuned by using different polymer matrices.

Entirely screen printed CdS/CdTe solar cell

NASA Astrophysics Data System (ADS)

Ikegami, S.; Matsumoto, H.; Uda, H.; Komatsu, Y.; Nakano, A.; Kuribayashi, K.

An entirely screen printed CdS/CdTe solar cell has been manufactured on a borosilicate glass substrate by successively repeating screen printing and heating in a belt furnace of each paste of CdS, Cd+Te, C, Ag+In and Ag. In a small cell with 0.78 sq cm area, the intrinsic conversion efficiency of 12.8 percent has been obtained; this value is the highest in the thin film type solar cells. On a large glass substrate of 30 x 30 sq cm, 28 unit solar cells connected in series have been constructed by this printing technique, their intrinsic efficiency being 8.5 percent. Under the roof top condition, no change in output power is observed in the present solar cells encapsulated over 206 days. Thus, the entirely screen printed CdS/CdTe solar cells can be expected as low cost, highly efficient, and stable solar cells.

TCRγδ+CD4−CD8− T Cells Suppress the CD8+ T-Cell Response to Hepatitis B Virus Peptides, and Are Associated with Viral Control in Chronic Hepatitis B

PubMed Central

Lai, Qintao; Ma, Shiwu; Ge, Jun; Huang, Zuxiong; Huang, Xuan; Jiang, Xiaotao; Li, Yongyin; Zhang, Mingxia; Zhang, Xiaoyong; Sun, Jian; Abbott, William G. H.; Hou, Jinlin

2014-01-01

The immune mechanisms underlying failure to achieve hepatitis B e antigen (HBeAg) seroconversion associated with viral control in chronic hepatitis B (CHB) remain unclear. Here we investigated the role of CD4−CD8− T (double-negative T; DNT) cells including TCRαβ+ DNT (αβ DNT) and TCRγδ+ DNT (γδ DNT) cells. Frequencies of circulating DNT cell subsets were measured by flow cytometry in a retrospective cohort of 51 telbivudine-treated HBeAg-positive CHB patients, 25 immune tolerant carriers (IT), 33 inactive carriers (IC), and 37 healthy controls (HC). We found that γδ DNT cell frequencies did not significantly change during treatment, being lower at baseline (P = 0.019) in patients with HBeAg seroconversion after 52 weeks of antiviral therapy (n = 20) than in those without (n = 31), and higher in the total CHB and IT than IC and HC groups (P<0.001). αβ DNT cell frequencies were similar for all groups. In vitro, γδ DNT cells suppressed HBV core peptide-stimulated interferon-γ and tumor necrosis factor-α production in TCRαβ+CD8+ T cells, which may require cell–cell contact, and could be partially reversed by anti-NKG2A. These findings suggest that γδ DNT cells limit CD8+ T cell response to HBV, and may impede HBeAg seroconversion in CHB. PMID:24551107

Photoemission studies of CdTe(100) and the Ag-CdTe(100) interface: Surface structure, growth behavior, Schottky barrier, and surface photovoltage

NASA Astrophysics Data System (ADS)

John, P.; Miller, T.; Hsieh, T. C.; Shapiro, A. P.; Wachs, A. L.; Chiang, T.-C.

1986-11-01

The clean CdTe(100) surface prepared by sputtering and annealing was studied with high-energy electron diffraction (HEED) and photoemission. HEED showed the surface to be a one-domain, (2×1) reconstruction. Photoemission spectra showed two surface-shifted components for the Cd 4d core level, with an intensity ratio of about 1:3, accounting for nearly an entire atomic layer. No surface-induced shifts for the Te 4d core level were detected. A model is proposed for the surface structure in which the surface layer is free of Te, and Cd atoms form dimers resulting in a (2×1) reconstruction; in addition, about (1/4) of the surface area is covered by excess loosely attached Cd atoms. Ag was evaporated on the surface at room temperature and found to grow three dimensionally in the [111] direction. The Ag was found to interact only weakly with the substrate, although the Cd atoms originally loosely bound on top of the surface were found to float on the evaporated Ag islands. A small coverage-dependent surface photovoltage, induced by the synchrotron radiation used for photoemission, was observed; with this effect taken into account, band bending was monitored, the final Fermi-level position being near 0.96 eV above the valence-band maximum. This corresponds to a Schottky-barrier height of about 0.60 eV for the n-type sample used in this experiment. The mechanism for generation of the surface photovoltage will be discussed.

Genetic vaccines to potentiate the effective CD103+ dendritic cell-mediated cross-priming of antitumor immunity.

PubMed

Zhang, Yi; Chen, Guo; Liu, Zuqiang; Tian, Shenghe; Zhang, Jiying; Carey, Cara D; Murphy, Kenneth M; Storkus, Walter J; Falo, Louis D; You, Zhaoyang

2015-06-15

The development of effective cancer vaccines remains an urgent, but as yet unmet, clinical need. This deficiency is in part due to an incomplete understanding of how to best invoke dendritic cells (DC) that are crucial for the induction of tumor-specific CD8(+) T cells capable of mediating durable protective immunity. In this regard, elevated expression of the transcription factor X box-binding protein 1 (XBP1) in DC appears to play a decisive role in promoting the ability of DC to cross-present Ags to CD8(+) T cells in the therapeutic setting. Delivery of DNA vaccines encoding XBP1 and tumor Ag to skin DC resulted in increased IFN-α production by plasmacytoid DC (pDC) from skin/tumor draining lymph nodes and the cross-priming of Ag-specific CD8(+) T cell responses associated with therapeutic benefit. Antitumor protection was dependent on cross-presenting Batf3(+) DC, pDC, and CD8(+) T cells. CD103(+) DC from the skin/tumor draining lymph nodes of the immunized mice appeared responsible for activation of Ag-specific naive CD8(+) T cells, but were dependent on pDC for optimal effectiveness. Similarly, human XBP1 improved the capacity of human blood- and skin-derived DC to activate human T cells. These data support an important intrinsic role for XBP1 in DC for effective cross-priming and orchestration of Batf3(+) DC-pDC interactions, thereby enabling effective vaccine induction of protective antitumor immunity. Copyright © 2015 by The American Association of Immunologists, Inc.

Effector CD8+ T cell IFN-γ production and cytotoxicity are enhanced by mild hyperthermia

PubMed Central

Mace, Thomas A.; Zhong, Lingwen; Kokolus, Kathleen M.; Repasky, Elizabeth A.

2012-01-01

Purpose Clinical trials combining hyperthermia with radiation and/or chemotherapy for cancer treatment have resulted in improved overall survival and control of local recurrences. The contribution of thermally enhanced anti-immune function in these effects is of considerable interest, but not understood; studies on the fundamental effects of elevated temperature on immune effector cells are needed. The goal of this study is to investigate the potential of mild hyperthermia to impact tumor antigen-specific (Ag) effector CD8+ T cell functions. Method Pmel-1 Ag-specific CD8+ T cells were exposed to mild hyperthermia and tested for changes in IFN-γ production and cytotoxicity. Additionally, overall plasma membrane organization and the phosphorylation of signaling proteins were also investigated following heat treatment. Results Exposing effector Pmel-1 specific CD8+ T cells to mild hyperthermia (39.5°C) resulted in significantly enhanced Ag-specific IFN-γ production and tumor target cell killing compared to that seen using lower temperatures (33 and 37°C). Further, inhibition of protein synthesis during hyperthermia did not reduce subsequent Ag-induced IFN-γ production by CD8+ T cells. Correlated with these effects, we observed a distinct clustering of GM1+ lipid microdomains at the plasma membrane and enhanced phosphorylation of LAT and PKCθ which may be related to an observed enhancement of Ag-specific effector CD8+ T cell IFN-γ gene transcription following mild hyperthermia. However, mitogen–mediated production of IFN-γ, which bypasses T cell receptor activation with antigen, was not enhanced. Conclusions Antigen-dependent effector T cell activity is enhanced following mild hyperthermia. These effects could potentially occur in patients being treated with thermal therapies. These data also provide support for the use of thermal therapy as an adjuvant for immunotherapies to improve CD8+ effector cell function. PMID:22235780

Structure and morphology of CdS thin films electrodeposited in fused salts

NASA Astrophysics Data System (ADS)

Markov, I.; Valova, E.; Ilieva, M.; Kristev, I.

1983-12-01

Thin films of CdS are catholically electrodeposited on copper and silver electrodes in solution of CdCl 2 and Na 2SO 3 in fused LiCl-KCl eutectic. The films consist only of the hexagonal wurtzite phase of CdS. The films grown on Cu substrates are polycrystalline without pronounced fibre texture. The films grown on Ag substrates show practically perfect (000-) texture exposing the Cd face at the film surface. Films deposited at high bath temperatures (450-500°C), low current densities (0.2-0.5 mA/cm 2) or doped with In during the growth are very smooth. From the morphological investigations it is concluded that the CdS films electrodeposited onto Ag substrates have well pronounced laminar structure.

Chiral recognition of phenylglycinol enantiomers based on N-acetyl-L-cysteine capped CdTe quantum dots in the presence of Ag+

NASA Astrophysics Data System (ADS)

Guo, Yuan; Zeng, Xiaoqing; Yuan, Haiyan; Huang, Yunmei; Zhao, Yanmei; Wu, Huan; Yang, Jidong

2017-08-01

In this study, a novel method for chiral recognition of phenylglycinol (PG) enantiomers was proposed. Firstly, water-soluble N-acetyl-L-cysteine (NALC)-capped CdTe quantum dots (QDs) were synthesized and experiment showed that the fluorescence intensity of the reaction system slightly enhancement when added PG enantiomers to NALC-capped CdTe quantum dots (QDs), but the R-PG and S-PG could not be distinguished. Secondly, when there was Ag+ presence in the reaction system, the experiment result was extremely interesting, the PG enantiomers cloud make NALC-capped CdTe QDs produce different fluorescence signal, in which the fluorescence of S-PG + Ag+ + NALC-CdTe system was significantly enhanced, and the fluorescence of R-PG + Ag+ + NALC-CdTe system was markedly decreased. Thirdly, all the enhanced and decreased of the fluorescence intensity were directly proportional to the concentration of R-PG and S-PG in the linearly range 10- 5-10- 7 mol·L- 1, respectively. So, the new method for simultaneous determination of the PG enantiomers was built too. The experiment result of the method was satisfactory with the detection limit of PG can reached 10- 7 mol·L- 1 and the related coefficient of S-PG and R-PG are 0.995 and 0.980, respectively. The method was highly sensitive, selective and had wider detection range compared with other methods.

Solution-Processed Ag Nanowires + PEDOT:PSS Hybrid Electrode for Cu(In,Ga)Se₂ Thin-Film Solar Cells.

PubMed

Shin, Donghyeop; Kim, Taegeon; Ahn, Byung Tae; Han, Seung Min

2015-06-24

To reduce the cost of the Cu(In,Ga)Se2 (CIGS) solar cells while maximizing the efficiency, we report the use of an Ag nanowires (NWs) + poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) ( PSS) hybrid transparent electrode, which was deposited using all-solution-processed, low-cost, scalable methods. This is the first demonstration of an Ag NWs + PSS transparent electrode applied to CIGS solar cells. The spin-coated 10-nm-thick PSS conducting polymer layer in our hybrid electrode functioned as a filler of empty space of an electrostatically sprayed Ag NW network. Coating of PSS on the Ag NW network resulted in an increase in the short-circuit current from 15.4 to 26.5 mA/cm(2), but the open-circuit voltage and shunt resistance still needed to be improved. The limited open-circuit voltage was found to be due to interfacial recombination that is due to the ineffective hole-blocking ability of the CdS film. To suppress the interfacial recombination between Ag NWs and the CdS film, a Zn(S,O,OH) film was introduced as a hole-blocking layer between the CdS film and Ag NW network. The open-circuit voltage of the cell sharply improved from 0.35 to 0.6 V, which resulted in the best cell efficiency of 11.6%.

Solid surface fluorescence immunosensor for ultrasensitive detection of hepatitis B virus surface antigen using PAMAM/CdTe@CdS QDs nanoclusters.

PubMed

Babamiri, Bahareh; Hallaj, Rahman; Salimi, Abdollah

2018-06-20

In the present study, we constructed an ultrasensitive solid surface fluorescence-immunosensor based on highly luminescent CdTe@CdS-PAMAM structures as nanoprobe for determination of HBsAg by monitoring fluorescence intensity. This strategy was achieved by using PAMAM as a signal amplifier; the PAMAM dendrimer with the many functional amine groups can amplify the fluorescence signal of QDs by covalent attachment of CdTe@CdS on PAMAM and hence, improve the sensitivity of the proposed method significantly. A sandwich type immunosensor was formed after the addition of HBsAg and the PAMAM-QD-Ab 2 , respectively. Under optimal conditions, the designed immunosensor demonstrates a good analytical performance for the HBsAg detection in an excellent linear range from 5 fg ml -1 to 0.15 ng ml -1 with the detection limit (LOD) of 0.6 fg ml -1 at a S/N ratio of 3. In addition, the analysis of human serum samples shows that the fluorescent immunoassay has the great potential for early diagnosis of hepatitis B and can be used for the detection of other tumor markers in clinical applications.

HLA Class II Defects in Burkitt Lymphoma: Bryostatin-1-Induced 17 kDa Protein Restores CD4+ T-Cell Recognition

PubMed Central

Hossain, Azim; God, Jason M.; Radwan, Faisal F. Y.; Amria, Shereen; Zhao, Dan; Bethard, Jennifer R.; Haque, Azizul

2011-01-01

While the defects in HLA class I-mediated Ag presentation by Burkitt lymphoma (BL) have been well documented, CD4+ T-cells are also poorly stimulated by HLA class II Ag presentation, and the reasons underlying this defect(s) have not yet been fully resolved. Here, we show that BL cells are deficient in their ability to optimally stimulate CD4+ T cells via the HLA class II pathway. The observed defect was not associated with low levels of BL-expressed costimulatory molecules, as addition of external co-stimulation failed to result in BL-mediated CD4+ T-cell activation. We further demonstrate that BL cells express the components of the class II pathway, and the defect was not caused by faulty Ag/class II interaction, because antigenic peptides bound with measurable affinity to BL-associated class II molecules. Treatment of BL with broystatin-1, a potent modulator of protein kinase C, led to significant improvement of functional class II Ag presentation in BL. The restoration of immune recognition appeared to be linked with an increased expression of a 17 kDa peptidylprolyl-like protein. These results demonstrate the presence of a specific defect in HLA class II-mediated Ag presentation in BL and reveal that treatment with bryostatin-1 could lead to enhanced immunogenicity. PMID:22162713

Induction of specific T helper-9 cells to inhibit glioma cell growth

PubMed Central

Zheng, Haiyan; Yang, Baohua; Xu, Dedong; Wang, Wenbo; Tan, Jie; Sun, Liyuan; Li, Qinghua; Sun, Li; Xia, Xuewei

2017-01-01

The effects of Staphylococcal enterotoxin B (SEB) on regulation of immune response have been recognized; whether SEB can enhance the effects of immunotherapy on glioma remains to be investigated. This study tests a hypothesis that administration with SEB enhances the effects of specific immunotherapy on glioma growth in mice. In this study, a glioma-bearing mouse model was developed by adoptive transfer with GL261 cells (a mouse glioma cell line). The mice were treated with the GL261 cell extracts (used as an Ag) with or without administration of SEB. We observed that treating glioma-bearing mice with the glioma Ag and SEB induced glioma-specific Th9 cells in both glioma tissue and the spleen. Treating CD4+ CD25− T cells with SEB increased p300 phosphorylation, histone H3K4 acetylation at the interleukin (IL)-9 promoter locus, and increased the IL-9 transcriptional factor binding to the IL-9 promoter. Treating CD4+ CD25− T cells with both SEB and glioma Ag induced glioma-specific Th9 cells. The glioma-specific Th9 cells induced glioma cell apoptosis in the culture. Treating the glioma-bearing mice with SEB and glioma Ag significantly inhibited the glioma growth. In conclusion, SEB plus glioma Ag immunotherapy inhibits the experimental glioma growth, which may be a novel therapeutic remedy for the treatment of glioma. PMID:28002799

Biosorption of heavy metals from industrial waste water by Geobacillus thermodenitrificans.

PubMed

Chatterjee, S K; Bhattacharjee, I; Chandra, G

2010-03-15

The metal binding capacity of the thermophilic bacteria Geobacillus thermodenitrificans isolated from Damodar river, India was assessed using synthetic metal solutions and industrial waste water. Biosorption preference of dead biomass of G. thermodenitrificans for the synthetic metal solutions was in the following order Fe(+3)>Cr(+3)>Co(+2)>Cu(+2)>Zn(+2)>Cd(+2)>Ag(+)>Pb(+2). It reduced the concentration of Fe(+3) (91.31%), Cr(+3) (80.80%), Co(+2) (79.71%), Cu(+2) (57.14%), Zn(+2) (55.14%), Cd(+2) (49.02%), Ag(+) (43.25%) and Pb(+2) (36.86%) at different optimum pH within 720 min. When this strain was applied in the industrial waste water biosorption preference was in the following order Fe(+3)>Cr(+3)>Cd(+2)>Pb(+2)>Cu(+2)>Co(+2)>Zn(+2)>Ag(+) and concentrations reduced up to 43.94% for Fe(+3), 39.2% for Cr(+3), 35.88% for Cd(+2), 18.22% for Pb(+2), 13.03% for Cu(+2), 11.43% for Co(+2), 9.02% for Zn(+2) and 7.65% for Ag(+) within 120 min. (c) 2009 Elsevier B.V. All rights reserved.

Room-temperature detection of mobile impurities in compound semiconductors by transient ion drift

NASA Astrophysics Data System (ADS)

Lyubomirsky, Igor; Rabinal, M. K.; Cahen, David

1997-05-01

We show that the transient ion drift (TID) method, which is based on recording junction capacitance under constant reverse bias [A. Zamouche, T. Heiser, and A. Mesli, Appl. Phys. Lett. 66, 631 (1995)], can be used not only for measurements of the diffusion coefficient of mobile impurities, but also to estimate the concentration of mobile species as part of the total dopant density. This is illustrated for CdTe, contaminated by Cu, and intentionally doped by Li or Ag and for CuInSe2. We show also that, with some restrictions, the TID method can be used if the mobile ions are major dopants. This is demonstrated using Schottky barriers on CdTe, and p-n junction devices in (Hg,Cd)Te, and CuInSe2. The values that we obtain for the diffusion coefficients (for Li, Ag, and Cu in CdTe and for Cu in CuInSe2) agree well with measured or extrapolated values, obtained by other methods, as reported in the literature. Furthermore, we could distinguish between diffusion and chemical reactions of dopants, as demonstrated for the case of Cu in CdTe and Ag-doped (Hg,Cd)Te. In the former case this allows us to separate copper-free from contaminated CdTe samples.

The Extent and Prediction of Heavy Metal Pollution in Soils of Shahrood and Damghan, Iran.

PubMed

Sakizadeh, Mohamad; Mirzaei, Rouhollah; Ghorbani, Hadi

2015-12-01

The levels of 12 heavy metals (Ag, Ba, Be, Cd, Co, Cr, Cu, Ni, Pb, Tl, V, Zn) were considered in 229 soil samples in Semnan Province, Iran. To discriminate between natural and anthropogenic inputs of heavy metals, factor analysis was used. Seven factors accounting for 90.5 % of the total variance were extracted. The mining and agricultural activities along with geogenic sources have been attributed as the main causes of the levels of heavy metals in the study area. The partial least squares regression was utilized to predict the level of soil pollution index (SPI) considering the concentrations of 12 heavy metals. The eigenvectors from the first three PLS represented more than 98 % of the overall variance. The correlation coefficient between the observed and predicted SPI was 0.99 indicating the high efficiency of this method. The resultant coefficient of determination for three PLS components was 0.984 confirming the predictive ability of this method.

Human health risks from heavy metals in fish of Buriganga river, Bangladesh.

PubMed

Kawser Ahmed, Md; Baki, Mohammad Abdul; Kundu, Goutam Kumar; Saiful Islam, Md; Monirul Islam, Md; Muzammel Hossain, Md

2016-01-01

Heavy metals are known to cause deleterious effects on human health through food chain. Human health risks were evaluated from consumption of heavy metal contaminated fish from Buriganga River in Bangladesh. Whole body of five fish species ( Puntius ticto, Puntius sophore, Puntius chola, Labeo rohita and Glossogobius giuris ) were analyzed which contained various concentrations of Cd, As, Pb, Cr, Ni, Zn, Se, Cu, Mo, Mn, Sb, Ba, V and Ag. Concentrations of Mn, Zn, Se and Pb in all fish species were above the Food Safety Guideline (FSG) by WHO/FAO. Assessment of noncarcinogenic health hazard by target hazard quotient (THQ) indicated no concern from consumption of these fish except for Mn. However, all metals together may affect human health as revealed by hazard index (HI). The target cancer risk (TR) values suggested carcinogenic risk from Ni and As. Taken together it can be concluded that there is potential human health risk in consuming fish from river Buriganga.

Chemical systematics of the Shergotty meteorite and the composition of its parent body (Mars)

NASA Technical Reports Server (NTRS)

Laul, J. C.; Smith, M. R.; Waenke, H.; Jagoutz, E.; Dreibus, G.

1986-01-01

Sixty elements in two bulk samples of Shergotty meteorite and 30 elements in various mineral separates of Shergotty were identified, using mainly INAA and RNAA techniques. In addition, elements leached out from powdered samples of Shergotty and EETA 79001 meteorites by 0.1 N HCl, as well as the elements of their residues, were analyzed. The results have indicated that Shergotty meteorite is homogeneous in its major element composition, but heterogeneous with respect to large-ion lithophile elements, such as K, Ba, Sr, Zr, Hf, Ta, Th, and rare-earth elements (REEs). It is even more heterogeneous with respect to volatile elements, such as Cd, Te, Tl, and Bi, and the siderophiles Au and Ag. The REE patterns of the Shergotty and EETA 79001 residues are identical, indicating that the parent magmas of both meteorites are compositionally similar. However, their leachate (phosphate) patterns are different, suggesting two components for the Shergotty, one of which is similar to the EETA 79001 leachate.

Ion exchange selectivity for cross-linked polyacrylic acid

NASA Technical Reports Server (NTRS)

May, C. E.; Philipp, W. H.

1983-01-01

The ion separation factors for 21 common metal ions with cross-linked polyacrylic acid were determined as a function of pH and the percent of the cross-linked polyacrylic acid neutralized. The calcium ion was used as a reference. At a pH of 5 the decreasing order of affinity of the ions for the cross-linked polyacrylic acid was found to be: Hg++, Fe+++, Pb++, Cr+++, Cu++, Cd++, Al+++, Ag+, Zn++, Ni++, Mn++, Co++, Ca++, Sr++, Ba++, Mg++, K+, Rb+, Cs+, Na+, and Li+. Members of a chemical family exhibited similar selectivities. The Hg++ ion appeared to be about a million times more strongly bound than the alkali metal ions. The relative binding of most of the metal ions varied with pH; the very tightly and very weakly bound ions showed the largest variations with pH. The calcium ion-hydrogen ion equilibrium was perturbed very little by the presence of the other ions. The separation factors and selectivity coefficients are discussed in terms of equilibrium and thermodynamic significance.

Multielement analysis of Canadian wines by inductively coupled plasma mass spectrometry (ICP-MS) and multivariate statistics.

PubMed

Taylor, Vivien F; Longerich, Henry P; Greenough, John D

2003-02-12

Trace element fingerprints were deciphered for wines from Canada's two major wine-producing regions, the Okanagan Valley and the Niagara Peninsula, for the purpose of examining differences in wine element composition with region of origin and identifying elements important to determining provenance. Analysis by ICP-MS allowed simultaneous determination of 34 trace elements in wine (Li, Be, Mg, Al, P, Cl, Ca, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Mo, Ag, Cd, Sb, I, Cs, Ba, La, Ce, Tl, Pb, Bi, Th, and U) at low levels of detection, and patterns in trace element concentrations were deciphered by multivariate statistical analysis. The two regions were discriminated with 100% accuracy using 10 of these elements. Differences in soil chemistry between the Niagara and Okanagan vineyards were evident, without a good correlation between soil and wine composition. The element Sr was found to be a good indicator of provenance and has been reported in fingerprinting studies of other regions.

Sodium to sodium carbonate conversion process

DOEpatents

Herrmann, S.D.

1997-10-14

A method is described for converting radioactive alkali metal into a low level disposable solid waste material. The radioactive alkali metal is atomized and introduced into an aqueous caustic solution having caustic present in the range of from about 20 wt % to about 70 wt % to convert the radioactive alkali metal to a radioactive alkali metal hydroxide. The aqueous caustic containing radioactive alkali metal hydroxide and CO{sub 2} are introduced into a thin film evaporator with the CO{sub 2} present in an amount greater than required to convert the alkali metal hydroxide to a radioactive alkali metal carbonate, and thereafter the radioactive alkali metal carbonate is separated from the thin film evaporator as a dry powder. Hydroxide solutions containing toxic metal hydroxide including one or more metal ions of Sb, As, Ba, Be, Cd, Cr, Pb, Hg, Ni, Se, Ag and Tl can be converted into a low level non-hazardous waste using the thin film evaporator of the invention. 3 figs.

Stable coordination of the inhibitory Ca2+ ion at MIDAS in integrin CD11b/CD18 by an antibody-derived ligand aspartate: Implications for integrin regulation and structure-based drug design

PubMed Central

Mahalingam, Bhuvaneshwari; Ajroud, Kaouther; Alonso, Jose Luis; Anand, Saurabh; Adair, Brian; Horenstein, Alberto L; Malavasi, Fabio; Xiong, Jian-Ping; Arnaout, M. Amin

2011-01-01

A central feature of integrin interaction with physiologic ligands is the monodentate binding of a ligand carboxylate to a Mg2+ ion hexacoordinated at the metal-ion-dependent-adhesion site (MIDAS) in the integrin A-domain. This interaction stabilizes the A-domain in the high-affinity state, which is distinguished from the default low-affinity state by tertiary changes in the domain that culminate in cell adhesion. Small molecule ligand-mimetic integrin antagonists act as partial agonists, eliciting similar activating conformational changes in the A-domain, which has contributed to paradoxical adhesion and increased patient mortality in large clinical trials. As with other ligand-mimetic integrin antagonists, the function-blocking monoclonal antibody (mAb) 107 binds MIDAS of integrin CD11b/CD18 A-domain (CD11bA), but in contrast, it favors the inhibitory Ca2+ ion over Mg2+ at MIDAS. We determined the crystal structures of the Fab fragment of mAb 107 complexed to the low- and high-affinity states of CD11bA. Favored binding of Ca2+ at MIDAS is caused by the unusual symmetric bidentate ligation of a Fab-derived ligand Asp to a heptacoordinated MIDAS Ca2+. Binding of Fab 107 to CD11bA did not trigger the activating tertiary changes in the domain or in the full-length integrin. These data show that denticity of the ligand Asp/Glu can modify divalent cation selectivity at MIDAS and hence integrin function. Stabilizing the Ca2+ ion at MIDAS by bidentate ligation to a ligand Asp/Glu may provide one approach for designing pure integrin antagonists. PMID:22095715

Enhanced Detection of Antigen-Specific CD4+ T Cells Using Altered Peptide Flanking Residue Peptide–MHC Class II Multimers

PubMed Central

Holland, Christopher J.; Dolton, Garry; Scurr, Martin; Ladell, Kristin; Schauenburg, Andrea J.; Miners, Kelly; Madura, Florian; Sewell, Andrew K.; Price, David A.

2015-01-01

Fluorochrome-conjugated peptide–MHC (pMHC) class I multimers are staple components of the immunologist’s toolbox, enabling reliable quantification and analysis of Ag-specific CD8+ T cells irrespective of functional outputs. In contrast, widespread use of the equivalent pMHC class II (pMHC-II) reagents has been hindered by intrinsically weaker TCR affinities for pMHC-II, a lack of cooperative binding between the TCR and CD4 coreceptor, and a low frequency of Ag-specific CD4+ T cell populations in the peripheral blood. In this study, we show that peptide flanking regions, extending beyond the central nonamer core of MHC-II–bound peptides, can enhance TCR–pMHC-II binding and T cell activation without loss of specificity. Consistent with these findings, pMHC-II multimers incorporating peptide flanking residue modifications proved superior for the ex vivo detection, characterization, and manipulation of Ag-specific CD4+ T cells, highlighting an unappreciated feature of TCR–pMHC-II interactions. PMID:26553072

Application of hybrid SiO2-coated CdTe nanocrystals for sensitive sensing of Cu2+ and Ag+ ions.

PubMed

Cao, Yongqiang; Zhang, Aiyu; Ma, Qian; Liu, Ning; Yang, Ping

2013-01-01

A new ion sensor based on hybrid SiO2 -coated CdTe nanocrystals (NCs) was prepared and applied for sensitive sensing of Cu(2+) and Ag(+) for the selective quenching of photoluminescence (PL) of NCs in the presence of ions. As shown by ion detection experiments conducted in pure water rather than buffer solution, PL responses of NCs were linearly proportional to concentrations of Cu(2+) and Ag(+) ions < 3 and 7 uM, respectively. Much lower detection limits of 42.37 nM for Cu(2+) and 39.40 nM for Ag(+) were also observed. In addition, the NC quenching mechanism was discussed in terms of the characterization of static and transient optical spectra. The transfer and trapping of photoinduced charges in NCs by surface energy levels of CuS and Ag2 S clusters as well as surface defects generated by the exchange of Cu(2+) and Ag(+) ions with Cd(2+) ion in NCs, resulted in PL quenching and other optical spectra changes, including steady-state absorption and transient PL spectra. It is our hope that these results will be helpful in the future preparation of new ion sensors. Copyright © 2012 John Wiley & Sons, Ltd.

Involvement of Ubiquitin-Editing Protein A20 in Modulating Inflammation in Rat Cochlea Associated with Silver Nanoparticle-Induced CD68 Upregulation and TLR4 Activation

NASA Astrophysics Data System (ADS)

Feng, Hao; Pyykkö, Ilmari; Zou, Jing

2016-05-01

Silver nanoparticles (AgNPs) were shown to temporarily impair the biological barriers in the skin of the external ear canal, mucosa of the middle ear, and inner ear, causing partially reversible hearing loss after delivery into the middle ear. The current study aimed to elucidate the molecular mechanism, emphasizing the TLR signaling pathways in association with the potential recruitment of macrophages in the cochlea and the modulation of inflammation by ubiquitin-editing protein A20. Molecules potentially involved in these signaling pathways were thoroughly analysed using immunohistochemistry in the rat cochlea exposed to AgNPs at various concentrations through intratympanic injection. The results showed that 0.4 % AgNPs but not 0.02 % AgNPs upregulated the expressions of CD68, TLR4, MCP1, A20, and RNF11 in the strial basal cells, spiral ligament fibrocytes, and non-sensory supporting cells of Corti's organ. 0.4 % AgNPs had no effect on CD44, TLR2, MCP2, Rac1, myosin light chain, VCAM1, Erk1/2, JNK, p38, IL-1β, TNF-α, TNFR1, TNFR2, IL-10, or TGF-β. This study suggested that AgNPs might confer macrophage-like functions on the strial basal cells and spiral ligament fibrocytes and enhance the immune activities of non-sensory supporting cells of Corti's organ through the upregulation of CD68, which might be involved in TLR4 activation. A20 and RNF11 played roles in maintaining cochlear homeostasis via negative regulation of the expressions of inflammatory cytokines.

Phosphine-free synthesis of high-quality reverse type-I ZnSe/CdSe core with CdS/CdxZn1 - xS/ZnS multishell nanocrystals and their application for detection of human hepatitis B surface antigen

NASA Astrophysics Data System (ADS)

Shen, Huaibin; Yuan, Hang; Niu, Jin Zhong; Xu, Shasha; Zhou, Changhua; Ma, Lan; Li, Lin Song

2011-09-01

Highly photoluminescent (PL) reverse type-I ZnSe/CdSe nanocrystals (NCs) and ZnSe/CdSe/CdS/CdxZn1 - xS/ZnS core/multishell NCs were successfully synthesized by a phosphine-free method. By this low-cost, 'green' synthesis route, more than 10 g of high-quality ZnSe/CdSe/CdS/CdxZn1 - xS/ZnS NCs were synthesized in a large scale synthesis. After the overgrowth of a CdS/CdxZn1 - xS/ZnS multishell on ZnSe/CdSe cores, the PL quantum yields (QYs) increased from 28% to 75% along with the stability improvement. An amphiphilic oligomer was used as a surface coating agent to conduct a phase transfer experiment, core/multishell NCs were dissolved in water by such surface modification and the QYs were still kept above 70%. The as-prepared water dispersible ZnSe/CdSe/CdS/CdxZn1 - xS/ZnS core/multishell NCs not only have high fluorescence QYs but also are extremely stable in various physiological conditions. Furthermore, a biosensor system (lateral flow immunoassay system, LFIA) for the detection of human hepatitis B surface antigen (HBsAg) was developed by using this water-soluble core/multishell NCs as a fluorescent label and a nitrocellulose filter membrane for lateral flow. The result showed that such ZnSe/CdSe/CdS/CdxZn1 - xS/ZnS core/multishell NCs were excellent fluorescent labels to detect HBsAg. The sensitivity of HBsAg detection could reach as high as 0.05 ng ml - 1.

Microscopic theory of cation exchange in CdSe nanocrystals.

PubMed

Ott, Florian D; Spiegel, Leo L; Norris, David J; Erwin, Steven C

2014-10-10

Although poorly understood, cation-exchange reactions are increasingly used to dope or transform colloidal semiconductor nanocrystals (quantum dots). We use density-functional theory and kinetic Monte Carlo simulations to develop a microscopic theory that explains structural, optical, and electronic changes observed experimentally in Ag-cation-exchanged CdSe nanocrystals. We find that Coulomb interactions, both between ionized impurities and with the polarized nanocrystal surface, play a key role in cation exchange. Our theory also resolves several experimental puzzles related to photoluminescence and electrical behavior in CdSe nanocrystals doped with Ag.

Reconnaissance exploration geochemistry in the central Brooks Range, northern Alaska: Implications for exploration of sediment-hosted zinc-lead-silver deposits

USGS Publications Warehouse

Kelley, K.D.; Kelley, D.L.

1992-01-01

A reconnaissance geochemical survey was conducted in the southern Killik River quadrangle, central Brooks Range, northern Alaska. The Brooks Range lies within the zone of continuous permafrost which may partially inhibit chemical weathering and oxidation. The minus 30-mesh and nonmagnetic heavy-mineral concentrate fractions of sediment samples were chosen as the sample media for the survey so that mechanical rather than chemical dispersion patterns would be enhanced. A total of 263 sites were sampled within the southern half of the Killik River quadrangle at an average sample density of approximately one sample per 12 km2. All samples were submitted for multi-element analyses. In the western and central Brooks Range, several known sediment-hosted Zn-Pb-Ag(-Ba) deposits occur within a belt of Paleozoic rocks of the Endicott Mountains allochthon. Exploration for this type of deposit in the Brook Range is difficult, due to the inherently high background values for Ba, Zn and Pb in shale and the common occurrence of metamorphic quartz-calcite veins, many of which contain traces of sulfide minerals. Stream sediments derived from these sources produce numerous geochemical anomalies which are not necessarily associated with significant mineralization. R-mode factor analysis provides a means of distinguishing between element associations related to lithology and those related to possible mineralization. Factor analysis applied to the multi-element data from the southern Killik River quadrangle resulted in the discovery of two additional Zn-Pb-Ag mineral occurrences of considerable areal extent which are 80-100 km east of any previously known deposit. These have been informally named the Kady and Vidlee. Several lithogeochemical element associations, or factors, and three factors which represent sulfide mineralization were identified: Ag-Pb-Zn (galena and sphalerite) and Fe-Ni-Co-Cu (pyrite ?? chalcopyrite) in the concentrate samples and Cd-Zn-Pb-As-Mn in the sediment samples. The distribution of high scores for each individual mineralization factor outlined several relatively large (200-250 km2) geochemically favorable areas. When the distribution of high scores for all three factors were superimposed, samples characterized by high scores for one or both of the concentrate mineralization factors and the mineralization factor in sediments define basin areas of approximately 48 and 64 km2 surrounding Kady and Vidlee, respectively. ?? 1992.

Marine chemistry of the permian phosphoria formation and basin, Southeast Idaho

USGS Publications Warehouse

Piper, D.Z.

2001-01-01

Major components in the Meade Peak Member of the Phosphoria Formation are apatite, dolomite, calcite, organic matter, and biogenic silica-a marine fraction; and aluminosilicate quartz debris-a terrigenous fraction. Samples from Enoch Valley, in southeast Idaho, have major element oxide abundances of Al2O3, Fe2O3, K2O, and TiO2 that closely approach the composition of the world shale average. Factor analysis further identifies the partitioning of several trace elements-Ba, Ga, Li, Sc, and Th and, at other sites in southeast Idaho and western Wyoming, B, Co, Cs, Hf, Rb, and Ta-totally into this fraction. Trace elements that fail to show such correlations or factor loadings include Ag, As, Cd, Cr, Cu, Mo, Ni, Se, the rare earth elements (REE), U, V, and Zn. Their terrigenous contribution is determined from minimum values of trace elements versus the terrigenous fraction. These minima too define trace element concentrations in the terrigenous fraction that approximately equal their concentrations in the world shale average. The marine fraction of trace elements represents the difference between the bulk trace element content of a sample and the terrigenous contribution. Of the trace elements enriched above a terrigenous contribution, Ag, Cr, Cu, Mo, and Se show strong loadings on the factor with an organic matter loading and U and the REE on the factor with a strong apatite loading. Cd, Ni, V, and Zn do not show a strong correlation with any of the marine components but are, nonetheless, strongly enriched above a terrigenous contribution. Interelement relationships between the trace elements identify two seawater sources-planktonic debris and basinal bottom water. Relationships between Cd, Cu, Mo, Zn, and possibly Ni and Se suggest a solely biogenic source. Their accumulation rates, and that of PO3-4, further identify the level of primary productivity as having been moderate and the residence time of water in the basin at 4.5 yr. Enrichments of Cr, U, V, and the REE, above both terrigenous and biogenic contributions, define bottom-water redox conditions as having been oxygen depleted, that is, denitrifying but not sulfate reducing.

Can percolation control doping, diffusion and phase segregation in (Hg,Cd)Te?

NASA Astrophysics Data System (ADS)

Cahen, David; Melamed, Ofer; Lubomirski, Igor

1999-02-01

We show that percolation can control not only diffusion in solids, but in the case of semiconductors also their electrical activity, via the doping action of the diffusing species. This occurs in (Hg 1- xCd x)Te (MCT) when xCd<0.8. The 10 7 times higher diffusivity at xCd<0.8 can be understood by realizing that the percolation threshold for an ideal FCC lattice is at 0.19. While normally Ag is a donor, it can be an acceptor by stabilizing the Hg(I) state. This is possible by interaction with 2 Hg neighbors, a process that will be favorable above the Hg percolation limit. The fast Ag diffusion also holds the clue for the occurrence of ultra-low concentration phase separation in this system, the result of a balance between elastic attraction and Coulombic repulsion between the charged dopants. Prima facie evidence for this phase separation comes from coulometric Ag titration in and out of MCT.

Capillary Printing of Highly Aligned Silver Nanowire Transparent Electrodes for High-Performance Optoelectronic Devices.

PubMed

Kang, Saewon; Kim, Taehyo; Cho, Seungse; Lee, Youngoh; Choe, Ayoung; Walker, Bright; Ko, Seo-Jin; Kim, Jin Young; Ko, Hyunhyub

2015-12-09

Percolation networks of silver nanowires (AgNWs) are commonly used as transparent conductive electrodes (TCEs) for a variety of optoelectronic applications, but there have been no attempts to precisely control the percolation networks of AgNWs that critically affect the performances of TCEs. Here, we introduce a capillary printing technique to precisely control the NW alignment and the percolation behavior of AgNW networks. Notably, partially aligned AgNW networks exhibit a greatly lower percolation threshold, which leads to the substantial improvement of optical transmittance (96.7%) at a similar sheet resistance (19.5 Ω sq(-1)) as compared to random AgNW networks (92.9%, 20 Ω sq(-1)). Polymer light-emitting diodes (PLEDs) using aligned AgNW electrodes show a 30% enhanced maximum luminance (33068 cd m(-2)) compared to that with random AgNWs and a high luminance efficiency (14.25 cd A(-1)), which is the highest value reported so far using indium-free transparent electrodes for fluorescent PLEDs. In addition, polymer solar cells (PSCs) using aligned AgNW electrodes exhibit a power conversion efficiency (PCE) of 8.57%, the highest value ever reported to date for PSCs using AgNW electrodes.

Partition coefficient of cadmium between organic soils and bean and oat plants

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

Siddqui, M.F.R.; Courchesne, F.; Kennedy, G.

Environmental fate models require the partition coefficient data of contaminants among two or more environmental compartments. The bioaccumulation of cadmium (Cd) by bean and oat plants grown on organic soils in a controlled growth chamber was investigated to validate the plant/soil partition coefficient. Total Cd was measured in the soils and in the different parts of the plants. The mean total Cd concentrations for soil cultivated with beans and oats were 0.86 and 0.69 {micro}g/g, respectively. Selective extractants (BaCl{sub 2}, Na-pyrophosphate and HNO{sub 3}-hydroxy) were used to evaluate solid phase Cd species in the soil. In the soil cultivated withmore » bean, BaCl{sub 2} exchangeable, Na-pyrophosphate extractable and HNO{sub 3}-NH{sub 2}OH extractable Cd represented 1.2, 1.6 and 50.9% of total soil Cd, respectively. For the soil cultivated with oats, the same extractants gave values of 1.1, 1.8 and 61.9%. Cd concentration levels in bean plants followed the sequence roots > fruits = stems > leaves (p < 0.01) while the following sequence was observed for oat plants: roots > fruits > stems > leaves (p < 0.05). The partition coefficient for total Cd (Cd{sub Plant tissue}/Cd{sub Soil}) was in the range of 0.28--0.55 for bean plants and 1.03--1.86 for oat plants.« less

Partial substitution of Zn Effects on the Structural and Electrical Properties of High Temperature Hg0.95Ag0.05Ba2Ca2Cu3O8+δ Superconductors

NASA Astrophysics Data System (ADS)

Abed, Noor S.; Fathi, Sabah J.; Jassim, Kareem A.; Mahdi, Shatha H.

2018-05-01

The effect of the Ag partial substitution at Hg site in HgOδ layer and Zn partial substitution at Ca site in CaO layer on the structure,Tc,electrical properties, and oxygen content for Hg-1223 have been studied. Bulk polycrystalline Hg1-xAgxBa2Ca2-yZnyCu3O8+δ compound samples with x=0.05 and y=0.0, 0.05, 0.1, 0.15, 0.2, 0.25, and 0.3, are synthesized by a solid state reaction process. Structural properties are studied by using X-ray powder pattern, the high temperature phase superconductor (Hg-1223) of the tetragonal structure didn't change with the partial substitution of Zn and Ag ions, lattice parameters c,c/a are established to vary with Ag and Zn- substitution. The surface morphology has been studied by using atomic force microscopes (AFM), showed that all specimens have good crystalline and homogeneous surface. Also give a best nano size value is 75.72 nm at x=0.05 and y=0.3. Four probe technique is used to measure Tc. The Tc were found to be increases from 129 K to 147 K and oxygen content were found to be increases with increasing Zn. In addition, dielectric properties (dielectric constant, dielectric loss factor, and the alternating electrical conductivity) are characterized directly by relating with Ag and Zn concentration.

[The thirty years of Acta Genetica Sinica].

PubMed

Li, Shao-Wu; Zhou, Su; Xue, Yong-Biao; Zhu, Li-Huang

2003-04-01

Acta Genetica Sinica (AGS) is sponsored by the Genetics Society of China and the Institute of Genetics and Developmental Biology of Chinese Academy of Sciences, and is published by Science Press. The journal is a leading national academic periodical and one of the Chinese key periodicals of natural sciences. Currently, AGS is being indexed by several well-known domestic and international indexing systems, such as the American Chemical Digest (CA), BIOSIS database, Biological Digest (BA), Medical Index and Russian Digest (P [symbol: see text]). Papers in the areas of genetics, developmental biology, cell molecular biology and evolution are regularly published by AGS.

Trace elements and radon in groundwater across the United States, 1992-2003

USGS Publications Warehouse

Ayotte, Joseph D.; Gronberg, Jo Ann M.; Apodaca, Lori E.

2011-01-01

Trace-element concentrations in groundwater were evaluated for samples collected between 1992 and 2003 from aquifers across the United States as part of the U.S. Geological Survey National Water-Quality Assessment Program. This study describes the first comprehensive analysis of those data by assessing occurrence (concentrations above analytical reporting levels) and by comparing concentrations to human-health benchmarks (HHBs). Data from 5,183 monitoring and drinking-water wells representing more than 40 principal and other aquifers in humid and dry regions and in various land-use settings were used in the analysis. Trace elements measured include aluminum (Al), antimony (Sb), arsenic (As), barium (Ba), beryllium (Be), boron (B), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), lithium (Li), manganese (Mn), molybdenum (Mo), nickel (Ni), selenium (Se), silver (Ag), strontium (Sr), thallium (Tl), uranium (U), vanadium (V), and zinc (Zn). Radon (Rn) gas also was measured and is included in the data analysis. Climate influenced the occurrence and distribution of trace elements in groundwater whereby more trace elements occurred and were found at greater concentrations in wells in drier regions of the United States than in humid regions. In particular, the concentrations of As, Ba, B, Cr, Cu, Mo, Ni, Se, Sr, U, V, and Zn were greater in the drier regions, where processes such as chemical evolution, ion complexation, evaporative concentration, and redox (oxidation-reduction) controls act to varying degrees to mobilize these elements. Al, Co, Fe, Pb, and Mn concentrations in groundwater were greater in humid regions of the United States than in dry regions, partly in response to lower groundwater pH and (or) more frequent anoxic conditions. In groundwater from humid regions, concentrations of Cu, Pb, Rn, and Zn were significantly greater in drinking-water wells than in monitoring wells. Samples from drinking-water wells in dry regions had greater concentrations of As, Ba, Pb, Li, Sr, V, and Zn, than samples from monitoring wells. In humid regions, however, concentrations of most trace elements were greater in monitoring wells than in drinking-water wells; the exceptions were Cu, Pb, Zn, and Rn. Cu, Pb, and Zn are common trace elements in pumps and pipes used in the construction of drinking-water wells, and contamination from these sources may have contributed to their concentrations. Al, Sb, Ba, B, Cr, Co, Fe, Mn, Mo, Ni, Se, Sr, and U concentrations were all greater in monitoring wells than in drinking-water wells in humid regions. Groundwater from wells in agricultural settings had greater concentrations of As, Mo, and U than groundwater from wells in urban settings, possibly owing to greater pH in the agricultural wells. Significantly greater concentrations of B, Cr, Se, Ag, Sr, and V also were found in agricultural wells in dry regions. Groundwater from dry-region urban wells had greater concentrations of Co, Fe, Pb, Li, Mn, and specific conductance than groundwater from agricultural wells. The geologic composition of aquifers and aquifer geochemistry are among the major factors affecting trace-element occurrence. Trace-element concentrations in groundwater were characterized in aquifers from eight major groups based on geologic material, including (1) unconsolidated sand and gravel; (2) glacial unconsolidated sand and gravel; (3) semiconsolidated sand; (4) sandstone; (5) sandstone and carbonate rock; (6) carbonate rock; (7) basaltic and other volcanic rock; and (8) crystalline rock. The majority of groundwater samples and the largest percentages of exceedences of HHBs were in the glacial and nonglacial unconsolidated sand and gravel aquifers; in these aquifers, As, Mn, and U are the most common trace elements exceeding HHBs. Overall, 19 percent of wells (962 of 5,097) exceeded an HHB for at least one trace element. The trace elements with HHBs included in this summary were Sb, As, Ba, Be, B, Cd, Cr,

A novel therapeutic hepatitis B vaccine induces cellular and humoral immune responses and breaks tolerance in hepatitis B virus (HBV) transgenic mice.

PubMed

Buchmann, Pascale; Dembek, Claudia; Kuklick, Larissa; Jäger, Clemens; Tedjokusumo, Raindy; von Freyend, Miriam John; Drebber, Uta; Janowicz, Zbigniew; Melber, Karl; Protzer, Ulrike

2013-02-06

Therapeutic vaccines are currently being developed for chronic hepatitis B and C. As an alternative to long-term antiviral treatment or to support only partially effective therapy, they should activate the patient's immune system effectively to fight and finally control the virus. A paradigm of therapeutic vaccination is the potent induction of T-cell responses against key viral antigens - besides activation of a humoral immune response. We have evaluated the potential of a novel vaccine formulation comprising particulate hepatitis B surface (HBsAg) and core antigen (HBcAg), and the saponin-based ISCOMATRIX™ adjuvant for its ability to stimulate T and B cell responses in C57BL/6 mice and its ability to break tolerance in syngeneic HBV transgenic (HBVtg) mice. In C57BL/6 mice, the vaccine induced multifunctional HBsAg- and HBcAg-specific CD8+ T cells detected by staining for IFNγ, TNFα and IL-2, as well as high antibody titers against both antigens. Vaccination of HBVtg animals induced potent HBsAg- and HBcAg-specific CD8+ T-cell responses in spleens and HBcAg-specific CD8+ T-cell responses in livers as well as anti-HBs seroconversion two weeks post injection. Vaccination further reduced HBcAg expression in livers of HBVtg mice without causing liver damage. In summary, this study demonstrates therapeutic efficacy of a novel vaccine formulation in a mouse model of immunotolerant, chronic HBV infection. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of creep feeding and supplemental glutamine or glutamine plus glutamate (Aminogut) on pre- and post-weaning growth performance and intestinal health of piglets

PubMed Central

2013-01-01

Background Creep feeding is used to stimulate piglet post-weaning feed consumption. L-Glutamine (GLN) is an important source of fuel for intestinal epithelial cells. The objective of this study was to determine the impact of creep feeding and adding GLN or AminoGut (AG; containing glutamine + glutamate) to pre- and post-weaning diets on pig performance and intestinal health. Litters (N = 120) were allotted to four treatments during 14–21 d of lactation: 1) No creep feed (NC, n = 45); 2) creep fed control diet (CFCD, n = 45); 3) creep fed 1% GLN (CFGLN, n = 15); 4) creep fed .88% AG (CFAG, n = 15). After weaning, the NC and CFCD groups were sub-divided into three groups (n = 15 each), receiving either a control nursery diet (NC-CD, CFCD-CD) or a diet supplemented with either GLN (NC-GLN, CFCD-GLN) or with AG (NC-AG, CFCD-AG). Litters that were creep fed with diets containing GLN or AG also were supplemented with those amino acids in the nursery diets (CFGLN-GLN, CFAG-AG). Glutamine was added at 1% in all three post-weaning diet phases and AG was added at .88% in phase 1 and 2 and at .66% in phase 3. Results Feed conversion (feed/gain) showed means among treatment means close to significance (P = 0.056) and Tukey’s test for pairwise mean comparisons showed that Pigs in the CFGLN-GLN group had the best feed conversion (feed/gain) in the first three-week period post-weaning, exceeding (P = 0.044) controls (CFCD-CD) by 34%. The NC-AG group had (P = 0.02) the greatest feed intake in the last three week of the study, exceeding controls (CFCD-CD) by 12%. CFGLN-GLN, CFCD-GLN and sow reared (SR) pigs had the greatest (P = 0.049) villi height exceeding the CFCD-AG group by 18%, 20% and 19% respectively. The CFAG-AG group had the deepest (P = 0.001) crypts among all treatments. CFGLN-GLN, CFCD-GLN and SR groups had the greatest (P = 0.001) number of cells proliferating (PCNA) exceeding those in the NC-CD group by 43%, 54% and 63% respectively. Sow reared pigs showed the greatest (P = 0.001) intestinal absorption capacity for xylose and mannitol. Conclusion Supplementation of creep feed and nursery diets with GLN and/or AminoGut in the first three week improved feed conversion possibly due to improved intestinal health. PMID:23916292

Facile, one-pot and scalable synthesis of highly emissive aqueous-based Ag,Ni:ZnCdS/ZnS core/shell quantum dots with high chemical and optical stability

NASA Astrophysics Data System (ADS)

Sahraei, Reza; Soheyli, Ehsan; Faraji, Zahra; Soleiman-Beigi, Mohammad

2017-11-01

We report here on a one-pot, mild and low cost aqueous-based synthetic route for the preparation of colloidally stable and highly luminescent dual-doped Ag,Ni:ZnCdS/ZnS core/shell quantum dots (QDs). The pure dopant emission of the Ni-doped core/shell QDs was found to be highly affected by the presence of a second dopant ion (Ag+). Results showed that the PL emission intensity increases while its peak position experiences an obvious blue shift with an increase in the content of Ag+ ions. Regarding the optical observations, we provide a simple scheme for absorption-recombination processes of the carriers through impurity centers. To obtain optimum conditions with a better emission characteristic, we also study the effect of different reaction parameters, such as refluxing temperature, the pH of the core and shell solution, molar ratio of the dopant ions (Ni:(Zn+Cd) and Ag:(Zn+Cd)), and concentration of the core and shell precursors. Nonetheless, the most effective parameter is the presence of the ZnS shell in a suitable amount to eliminate surface trap states and enhance their emission intensity. It can also improve the bio-compatibility of the prepared QDs by restricting the Cd2+ toxic ions inside the core of the QDs. The present suggested route also revealed the remarkable optical and chemical stability of the colloidal QDs which establishes them as a decent kind of nano-scale structure for light emitting applications, especially in biological technologies. The suggested process also has the potential to be scaled-up while maintaining the emission characteristics and structural quality necessary for industrial applications in optoelectronic devices.

Characterization of polycyclic aromatic hydrocarbons in fugitive PM10 emissions from an integrated iron and steel plant.

PubMed

Khaparde, V V; Bhanarkar, A D; Majumdar, Deepanjan; Rao, C V Chalapati

2016-08-15

Fugitive emissions of PM10 (particles <10μm in diameter) and associated polycyclic aromatic hydrocarbons (PAHs) were monitored in the vicinity of coking unit, sintering unit, blast furnace and steel manufacturing unit in an integrated iron and steel plant situated in India. Concentrations of PM10, PM10-bound total PAHs, benzo (a) pyrene, carcinogenic PAHs and combustion PAHs were found to be highest around the sintering unit. Concentrations of 3-ring and 4-ring PAHs were recorded to be highest in the coking unit whereas 5-and 6-ring PAHs were found to be highest in other units. The following indicatory PAHs were identified: indeno (1,2,3-cd) pyrene, dibenzo (a,h) anthracene, benzo (k) fluoranthene in blast furnace unit; indeno (1,2,3-cd) pyrene, dibenzo (a,h) anthracene, chrysene in sintering unit; Anthracene, fluoranthene, chrysene in coking unit and acenaphthene, fluoranthene, fluorene in steel making unit. Total-BaP-TEQ (Total BaP toxic equivalent quotient) and BaP-MEQ (Total BaP mutagenic equivalent quotient) concentration levels ranged from 2.4 to 231.7ng/m(3) and 1.9 to 175.8ng/m(3), respectively. BaP and DbA (dibenzo (a,h) anthracene) contribution to total-BaP-TEQ was found to be the highest. Copyright © 2016 Elsevier B.V. All rights reserved.

Distribution and environmental assessment of trace elements contamination of water, sediments and flora from Douro River estuary, Portugal.

PubMed

Ribeiro, C; Couto, C; Ribeiro, A R; Maia, A S; Santos, M; Tiritan, M E; Pinto, E; Almeida, A A

2018-10-15

The present study evaluated the content and distribution of several trace elements (Li, Be, Al, V, Cr, Co, Ni, Cu, Zn, Se, Mo, Ag, Cd, Sb, Ba, Tl, Pb, and U) in the Douro River estuary. For that, three matrices were collected (water, sediments and native local flora) to assess the extent of contamination by these elements in this estuarine ecosystem. Results showed their occurrence in estuarine water and sediments, but significant differences were recorded on the concentration levels and pattern of distribution among both matrices and sampling points. Generally, the levels of trace elements were higher in the sediments than in the respective estuarine water. Nonetheless, no correlation among trace elements was determined between water and sediments, except for Cd. Al was the trace element found at highest concentration at both sediments and water followed by Zn. Pollution indices such as geo-accumulation (I geo ), enrichment factor (EF) and contamination factor (CF) were determined to understand the levels and sources of trace elements pollution. I geo showed strong contamination by anthropogenic activities for Li, Al, V, Cr, Ni, Cu, Zn, Ba and Pb at all sampling points while EF and CF demonstrated severe enrichment and contamination by Se, Sb and Pb. Levels of trace elements were compared to acceptable values for aquatic organisms and Sediment Quality Guidelines. The concentration of some trace elements, namely Al, Pb and Cu, were higher than those considered acceptable, with potential negative impact on local living organisms. Nevertheless, permissible values for all trace elements are still not available, demonstrating that further studies are needed in order to have a complete assessment of environmental risk. Furthermore, the occurrence and possible accumulation of trace elements by local plant species and macroalgae were investigated as well as their potential use as bioindicators of local pollution and for phytoremediation purposes. Copyright © 2018 Elsevier B.V. All rights reserved.

Geochemistry of the Patricia Zn-Pb-Ag Deposit (paguanta, NE Chile)

NASA Astrophysics Data System (ADS)

Chinchilla Benavides, D.; Merinero Palomares, R.; Piña García, R.; Ortega Menor, L.; Lunar Hernández, R.

2013-12-01

The Patricia Zn-Pb-Ag ore deposit is located within the Paguanta mining project, situated at the northern end of the Andean Oligocene Porphyry Copper Belt of Chile. The sulfide mineralization occurs as W-E oriented veins hosted in volcanic rocks, mainly andesite (pyroclastic, ash and lavas), of Upper Cretaceous to Middle Tertiary age. The ore mineralogy (obtained by EMPA analyses) comprises in order of abundance, pyrite, sphalerite (5.5 - 10.89 wt % Fe, 9.8-19 % molar FeS and 0.52 wt % Cd), galena, arsenopyrite, chalcopyrite and Ag-bearing sulfosalts. The veins show a zoned and banded internal structure with pyrite at the edges and sphalerite in the center. The Ag occurs mostly as Ag-Cu-Sb sulfosalts, in order of abundance: series freibergite - argentotennantite -polybasite and stephanite. Other minor Ag phases such as argentite, pyrargirite and diaphorite were also identified. These Ag phases are typically associated with the base-metal sulfides. Freibergite occurs filling voids within sphalerite, chalcopyrite and at the contact between sphalerite and galena. Polybasite, stephanite, pyrargirite and argentite are mostly in close association with freibergite. In the case of diaphorite, it commonly occurs filling voids between galena crystals or as inclusions within galena. Some minor Ag-bearing sulfosalts are also identified between pyrite crystals. The alteration minerals are dominated by chlorite, illite and kaolinite. The gangue minerals consist of quartz and carbonates identified by XRD as kutnahorite. We obtained linear correlation statistically significant only for Ag, As Au, Cd, Cu, Pb, Sb and Zn and therefore we generated an enhanced scatter plot matrix of these elements. Bulk rock analyses (ICP/MS and XRF) of drill cores show that Ag is strongly and positively correlated with Pb and As, moderately with Cd, Sb, Au and Zn and weakly with Cu, while Au is moderately and positively correlated with Ag, As, Cd, Sb and Zn and weakly with Cu and Pb. These results are consistent with bulk rock analyses of selected and mineralized samples were similar correlations have been obtained. Ag positive correlations indicate that the formation of Ag-bearing minerals is mainly associated with galena, arsenopyrite and sphalerite occurrence. Au positive correlations indicate that this element occurs in close relationship with Ag-bearing minerals, arsenopyrite and sphalerite. The weak correlation between Cu and Ag and Au indicate that the formation of chalcopyrite is not related with the main stages of Ag-Au mineralization. The main conclusion of this study is that geochemical analyses along drill cores that cut mineralization confirm that the occurrence of Ag and Au in the Paguanta deposit is associated with the formation of galena, arsenopyrite and sphalerite. This study also confirm previous conclusions suggesting that the Patricia Pb-Zn-Ag ore deposit probably represents an example of epithermal mineralization of intermediate sulfidation state, with periods of lower sulfidation state during sphalerite deposition.

The molecular bases of δ/αβ T cell-mediated antigen recognition.

PubMed

Pellicci, Daniel G; Uldrich, Adam P; Le Nours, Jérôme; Ross, Fiona; Chabrol, Eric; Eckle, Sidonia B G; de Boer, Renate; Lim, Ricky T; McPherson, Kirsty; Besra, Gurdyal; Howell, Amy R; Moretta, Lorenzo; McCluskey, James; Heemskerk, Mirjam H M; Gras, Stephanie; Rossjohn, Jamie; Godfrey, Dale I

2014-12-15

αβ and γδ T cells are disparate T cell lineages that can respond to distinct antigens (Ags) via the use of the αβ and γδ T cell Ag receptors (TCRs), respectively. Here we characterize a population of human T cells, which we term δ/αβ T cells, expressing TCRs comprised of a TCR-δ variable gene (Vδ1) fused to joining α and constant α domains, paired with an array of TCR-β chains. We demonstrate that these cells, which represent ∼50% of all Vδ1(+) human T cells, can recognize peptide- and lipid-based Ags presented by human leukocyte antigen (HLA) and CD1d, respectively. Similar to type I natural killer T (NKT) cells, CD1d-lipid Ag-reactive δ/αβ T cells recognized α-galactosylceramide (α-GalCer); however, their fine specificity for other lipid Ags presented by CD1d, such as α-glucosylceramide, was distinct from type I NKT cells. Thus, δ/αβTCRs contribute new patterns of Ag specificity to the human immune system. Furthermore, we provide the molecular bases of how δ/αβTCRs bind to their targets, with the Vδ1-encoded region providing a major contribution to δ/αβTCR binding. Our findings highlight how components from αβ and γδTCR gene loci can recombine to confer Ag specificity, thus expanding our understanding of T cell biology and TCR diversity. © 2014 Pellicci et al.

The molecular bases of δ/αβ T cell–mediated antigen recognition

PubMed Central

Pellicci, Daniel G.; Uldrich, Adam P.; Le Nours, Jérôme; Ross, Fiona; Chabrol, Eric; Eckle, Sidonia B.G.; de Boer, Renate; Lim, Ricky T.; McPherson, Kirsty; Besra, Gurdyal; Howell, Amy R.; Moretta, Lorenzo; McCluskey, James; Heemskerk, Mirjam H.M.; Gras, Stephanie

2014-01-01

αβ and γδ T cells are disparate T cell lineages that can respond to distinct antigens (Ags) via the use of the αβ and γδ T cell Ag receptors (TCRs), respectively. Here we characterize a population of human T cells, which we term δ/αβ T cells, expressing TCRs comprised of a TCR-δ variable gene (Vδ1) fused to joining α and constant α domains, paired with an array of TCR-β chains. We demonstrate that these cells, which represent ∼50% of all Vδ1+ human T cells, can recognize peptide- and lipid-based Ags presented by human leukocyte antigen (HLA) and CD1d, respectively. Similar to type I natural killer T (NKT) cells, CD1d-lipid Ag-reactive δ/αβ T cells recognized α-galactosylceramide (α-GalCer); however, their fine specificity for other lipid Ags presented by CD1d, such as α-glucosylceramide, was distinct from type I NKT cells. Thus, δ/αβTCRs contribute new patterns of Ag specificity to the human immune system. Furthermore, we provide the molecular bases of how δ/αβTCRs bind to their targets, with the Vδ1-encoded region providing a major contribution to δ/αβTCR binding. Our findings highlight how components from αβ and γδTCR gene loci can recombine to confer Ag specificity, thus expanding our understanding of T cell biology and TCR diversity. PMID:25452463

Health Risks and Contamination Levels of Heavy Metals in Dusts from Parks and Squares of an Industrial City in Semi-Arid Area of China

PubMed Central

Han, Xiufeng; Lu, Xinwei; Qinggeletu; Wu, Yongfu

2017-01-01

The contamination characteristics and health risk of barium (Ba), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), vanadium (V), zinc (Zn), arsenic (As), mercury (Hg), and cadmium (Cd) in samples of dust gathered from squares and parks of Baotou city, an industrial city situated in a semi-arid location of the northwest China were investigated. The contents of Ba, Co, Cr, Cu, Mn, Ni, V, Pb, and Zn in the collected dust samples were determined using X-ray fluorescence spectrometry, while the contents of As and Hg in the dust were investigated by use of the ICP-MS. Further, cadmium was quantified through the atomic absorption spectrometry. Levels of contamination of heavy metals analyzed in the dust samples were evaluated using the Geo-Accumulation index (Igeo) as well as through a Pollution Load Index (PLI). Their health risks to children and adults were evaluated based on the US EPA model of health risk. The findings portrayed that the mean concentrations of Ba, Co Cr, Cu, Pb, V, Cd, and Hg were elevated as compared with their local soil background values. Mean values of Igeo illustrate the order of Co > Cr> Cd > Hg > Pb > Cu > Ba > V > Ni > Mn > Zn > As. It was evident that dusts from the parks and squares were “unpolluted” to “moderately polluted”. Assessment of health risk depicts that ingestion is the foremost route of exposure in regard to the heavy metals, then the dermal adsorption follows. Hg exposure from dust might also set impending health threats to children. Besides, the cancer risks of Co, Cr, Ni, Cd, and As are considered to be within the presently tolerable range. PMID:28783109

Single-Cell RNA Sequencing Reveals Expanded Clones of Islet Antigen-Reactive CD4+ T Cells in Peripheral Blood of Subjects with Type 1 Diabetes.

PubMed

Cerosaletti, Karen; Barahmand-Pour-Whitman, Fariba; Yang, Junbao; DeBerg, Hannah A; Dufort, Matthew J; Murray, Sara A; Israelsson, Elisabeth; Speake, Cate; Gersuk, Vivian H; Eddy, James A; Reijonen, Helena; Greenbaum, Carla J; Kwok, William W; Wambre, Erik; Prlic, Martin; Gottardo, Raphael; Nepom, Gerald T; Linsley, Peter S

2017-07-01

The significance of islet Ag-reactive T cells found in peripheral blood of type 1 diabetes (T1D) subjects is unclear, partly because similar cells are also found in healthy control (HC) subjects. We hypothesized that key disease-associated cells would show evidence of prior Ag exposure, inferred from expanded TCR clonotypes, and essential phenotypic properties in their transcriptomes. To test this, we developed single-cell RNA sequencing procedures for identifying TCR clonotypes and transcript phenotypes in individual T cells. We applied these procedures to analysis of islet Ag-reactive CD4 + memory T cells from the blood of T1D and HC individuals after activation with pooled immunodominant islet peptides. We found extensive TCR clonotype sharing in Ag-activated cells, especially from individual T1D subjects, consistent with in vivo T cell expansion during disease progression. The expanded clonotype from one T1D subject was detected at repeat visits spanning >15 mo, demonstrating clonotype stability. Notably, we found no clonotype sharing between subjects, indicating a predominance of "private" TCR specificities. Expanded clones from two T1D subjects recognized distinct IGRP peptides, implicating this molecule as a trigger for CD4 + T cell expansion. Although overall transcript profiles of cells from HC and T1D subjects were similar, profiles from the most expanded clones were distinctive. Our findings demonstrate that islet Ag-reactive CD4 + memory T cells with unique Ag specificities and phenotypes are expanded during disease progression and can be detected by single-cell analysis of peripheral blood. Copyright © 2017 by The American Association of Immunologists, Inc.

Abundance, distribution and bioavailability of major and trace elements in surface sediments from the Cai River estuary and Nha Trang Bay (South China Sea, Vietnam)

NASA Astrophysics Data System (ADS)

Koukina, S. E.; Lobus, N. V.; Peresypkin, V. I.; Dara, O. M.; Smurov, A. V.

2017-11-01

Major (Si, Al, Fe, Ti, Mg, Ca, Na, K, S, P), minor (Mn) and trace (Li, V, Cr, Co, Ni, Cu, Zn, As, Sr, Zr, Mo, Cd, Ag, Sn, Sb, Cs, Ba, Hg, Pb, Bi and U) elements, their chemical forms and the mineral composition, organic matter (TOC) and carbonates (TIC) in surface sediments from the Cai River estuary and Nha Trang Bay were first determined along the salinity gradient. The abundance and ratio of major and trace elements in surface sediments are discussed in relation to the mineralogy, grain size, depositional conditions, reference background and SQG values. Most trace-element contents are at natural levels and are derived from the composition of rocks and soils in the watershed. A severe enrichment of Ag is most likely derived from metal-rich detrital heavy minerals such as Ag-sulfosalts. Along the salinity gradient, several zones of metal enrichment occur in surface sediments because of the geochemical fractionation of the riverine material. The parts of actually and potentially bioavailable forms (isolated by four single chemical reagent extractions) are most elevated for Mn and Pb (up to 36% and 32% of total content, respectively). The possible anthropogenic input of Pb in the region requires further study. Overall, the most bioavailable parts of trace elements are associated with easily soluble amorphous Fe and Mn oxyhydroxides. The sediments are primarily enriched with bioavailable metal forms in the riverine part of the estuary. Natural (such as turbidities) and human-generated (such as urban and industrial activities) pressures are shown to influence the abundance and speciation of potential contaminants and therefore change their bioavailability in this estuarine system.

CD22 serves as a receptor for soluble IgM.

PubMed

Adachi, Takahiro; Harumiya, Satoru; Takematsu, Hiromu; Kozutsumi, Yasunori; Wabl, Matthias; Fujimoto, Manabu; Tedder, Thomas F

2012-01-01

CD22 (Siglec-2) is a B-cell membrane-bound lectin that recognizes glycan ligands containing α2,6-linked sialic acid (α2,6Sia) and negatively regulates signaling through the B-cell Ag receptor (BCR). Although CD22 has been investigated extensively, its precise function remains unclear due to acting multiple phases. Here, we demonstrate that CD22 is efficiently activated in trans by complexes of Ag and soluble IgM (sIgM) due to the presence of glycan ligands on sIgM. This result strongly suggests sIgM as a natural trans ligand for CD22. Also, CD22 appears to serve as a receptor for sIgM, which induces a negative feedback loop for B-cell activation similar to the Fc receptor for IgG (FcγRIIB). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A novel approach to tracking antigen-experienced CD4 T cells into functional compartments via tandem deep and shallow TCR clonotyping.

PubMed

Estorninho, Megan; Gibson, Vivienne B; Kronenberg-Versteeg, Deborah; Liu, Yuk-Fun; Ni, Chester; Cerosaletti, Karen; Peakman, Mark

2013-12-01

Extensive diversity in the human repertoire of TCRs for Ag is both a cornerstone of effective adaptive immunity that enables host protection against a multiplicity of pathogens and a weakness that gives rise to potential pathological self-reactivity. The complexity arising from diversity makes detection and tracking of single Ag-specific CD4 T cells (ASTs) involved in these immune responses challenging. We report a tandem, multistep process to quantify rare TCRβ-chain variable sequences of ASTs in large polyclonal populations. The approach combines deep high-throughput sequencing (HTS) within functional CD4 T cell compartments, such as naive/memory cells, with shallow, multiple identifier-based HTS of ASTs identified by activation marker upregulation after short-term Ag stimulation in vitro. We find that clonotypes recognizing HLA class II-restricted epitopes of both pathogen-derived Ags and self-Ags are oligoclonal and typically private. Clonotype tracking within an individual reveals private AST clonotypes resident in the memory population, as would be expected, representing clonal expansions (identical nucleotide sequence; "ultraprivate"). Other AST clonotypes share CDR3β amino acid sequences through convergent recombination and are found in memory populations of multiple individuals. Tandem HTS-based clonotyping will facilitate studying AST dynamics, epitope spreading, and repertoire changes that arise postvaccination and following Ag-specific immunotherapies for cancer and autoimmune disease.

RasGRP1 regulates antigen-induced developmental programming by naive CD8 T cells.

PubMed

Priatel, John J; Chen, Xiaoxi; Huang, Yu-Hsuan; Chow, Michael T; Zenewicz, Lauren A; Coughlin, Jason J; Shen, Hao; Stone, James C; Tan, Rusung; Teh, Hung Sia

2010-01-15

Ag encounter by naive CD8 T cells initiates a developmental program consisting of cellular proliferation, changes in gene expression, and the formation of effector and memory T cells. The strength and duration of TCR signaling are known to be important parameters regulating the differentiation of naive CD8 T cells, although the molecular signals arbitrating these processes remain poorly defined. The Ras-guanyl nucleotide exchange factor RasGRP1 has been shown to transduce TCR-mediated signals critically required for the maturation of developing thymocytes. To elucidate the role of RasGRP1 in CD8 T cell differentiation, in vitro and in vivo experiments were performed with 2C TCR transgenic CD8 T cells lacking RasGRP1. In this study, we report that RasGRP1 regulates the threshold of T cell activation and Ag-induced expansion, at least in part, through the regulation of IL-2 production. Moreover, RasGRP1(-/-) 2C CD8 T cells exhibit an anergic phenotype in response to cognate Ag stimulation that is partially reversible upon the addition of exogenous IL-2. By contrast, the capacity of IL-2/IL-2R interactions to mediate Ras activation and CD8 T cell expansion and differentiation appears to be largely RasGRP1-independent. Collectively, our results demonstrate that RasGRP1 plays a selective role in T cell signaling, controlling the initiation and duration of CD8 T cell immune responses.

[Relationship between HBeAg from HBsAg positive mothers and regulatory T cells in neonates and its influence on HBV intrauterine transmission].

PubMed

Hao, H Y; Yang, Z Q; Xu, X X; Wang, X F; Wang, B; Shi, X H; Fu, Z D; Wang, B; Wang, S P

2017-10-10

Objective: To explore the relationship between HBeAg in HBsAg positive mothers and CD(4)(+)CD(25)(+) Foxp3 (+)regulatory T cells (Treg) in newborns, as well as how they would influence the increasing risk on HBV intrauterine transmission. Methods: We collected information on general demographic characteristics and delivery on 270 HBsAg positive mothers and their newborns from the Third People's Hospital of Taiyuan. Fluorescence quantitative polymerase chain reaction (FQ-PCR) and chemiluminescence immunoassay (CLIA) were used to detect HBV DNA and HBV serological markers in peripheral blood from both mothers and neonates. The expression of Treg and other immune cells in peripheral blood of neonates were detected with flow cytometry (FCM). Results: Maternal HBeAg positive rates were associated with an increased risk of intrauterine transmission ( OR =4.08, 95 %CI : 1.89-8.82). Rates of Treg in newborns born to HBsAg-positive mothers were higher than that of the negative group ( Z =2.29, P =0.022). Each pair of the subjects was assigned to five different groups according to the HBeAg titers of mothers. Frequencies of both Treg and HBeAg in newborns and HBV DNA in mothers between the above said 5 groups showed similar trends of changing patterns and the differences between groups were statistically significant(χ(2)=18.73, P <0.001; χ(2)=181.60, P <0.001; χ(2)=183.09, P <0.001). Results from partial correlation analysis showed that after adjusting for neonatal HBeAg and maternal HBV DNA, mother's HBeAg titers were positively related to the percentage of Treg in their newborns ( r(s) =0.19, P =0.039). In addition, the frequencies of Treg were negatively correlated with pDC and CD(4)(+) T cell in their newborns ( r(s) =-0.21, P =0.017; r(s) =-0.23, P =0.009). Conclusion: HBeAg from HBsAg positive mothers might have inhibited the function of neonatal DC cells and T cells to reduce the immune response to HBV by up-regulating the proportion of Treg and finally increased the risk of HBV intrauterine transmission.

The accumulation of regulatory T cells in the hepatic hilar lymph nodes in biliary atresia.

PubMed

Sakamoto, Naoya; Muraji, Toshihiro; Ohtani, Haruo; Masumoto, Kouji

2017-10-01

A proposed etiopathogenesis of biliary atresia (BA) involves T-cell-mediated inflammatory bile duct damage and progressive hepatic fibrosis. Pediatric surgeons often observe swelling of the hepatic hilar lymph nodes during the Kasai procedure. Given the importance of regulatory mechanisms in immune responses, the present study was designed to analyze the quantitative changes of regulatory T cells (T reg cells) in the hepatic hilar lymph nodes (hepatic hilar LNs) and peripheral blood (PB) in BA. The hepatic hilar LNs and PB obtained during the Kasai procedure were analyzed by flow cytometry. The ratios of total and active Tregs to the total CD4 + cells in the PB and the hepatic hilar LNs were compared. In patients with BA, the ratios of both the total and active T reg cells in the hepatic hilar LNs were higher than those in the PB (total T reg cells: PB vs. LN; P < 0.001; active T reg cells: PB vs. LN; P = 0.001). In BA patients, the increase in the ratio of active T reg cells to the CD4 + cells in the LNs in comparison to the PB was greater than that in control patients. The ratio observed in the BA patients was almost double the ratio observed in the control patients. The median LN/PB ratio in the BA patients was 3.1, while that in controls was 1.6 (P = 0.03). The present study showed that the ratios of both total T reg cells and active T reg cells were higher in the hepatic hilar lymph nodes of BA patients. This finding could shed light on the pathogenesis of BA.

Primary fragmentation pathways of gas phase [M(uracil-H)(uracil)]+ complexes (M=Zn, Cu, Ni, Co, Fe, Mn, Cd, Pd , Mg, Ca, Sr, Ba, and Pb): loss of uracil versus HNCO.

PubMed

Ali, Osama Y; Randell, Nicholas M; Fridgen, Travis D

2012-04-23

Complexes formed between metal dications, the conjugate base of uracil, and uracil are investigated by sustained off-resonance irradiation collision-induced dissociation (SORI-CID) in a Fourier transform ion cyclotron resonance (FTICR) mass spectrometer. Positive-ion electrospray spectra show that [M(Ura-H)(Ura)](+) (M=Zn, Cu, Ni, Co, Fe, Mn, Cd, Pd, Mg, Ca, Sr, Ba, or Pb) is the most abundant ion even at low concentrations of uracil. SORI-CID experiments show that the main primary decomposition pathway for all [M(Ura-H)(Ura)](+) , except where M=Ca, Sr, Ba, or Pb, is the loss of HNCO. Under the same SORI-CID conditions, when M is Ca, Sr, Ba, or Pb, [M(Ura-H)(Ura)](+) are shown to lose a molecule of uracil. Similar results were observed under infrared multiple-photon dissociation excitation conditions, except that [Ca(Ura-H)(Ura)](+) was found to lose HNCO as the primary fragmentation product. The binding energies between neutral uracil and [M(Ura-H)](+) (M=Zn, Cu, Ni, Fe, Cd, Pd ,Mg, Ca, Sr Ba, or Pb) are calculated by means of electronic-structure calculations. The differences in the uracil binding energies between complexes which lose uracil and those which lose HNCO are consistent with the experimentally observed differences in fragmentation pathways. A size dependence in the binding energies suggests that the interaction between uracil and [M(Ura-H)](+) is ion-dipole complexation and the experimental evidence presented supports this. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biomedical silver-109m isotope generator

DOEpatents

Wanek, Philip M.; Steinkruger, Frederick J.; Moody, David C.

1987-01-01

A method, composition of matter, and apparatus for producing substantially pure Ag-109m for use in biomedical imaging techniques. Cd-109, which decays with a half-life of 453 days to Ag-109m is loaded onto an ion exchange column consisting of particulate tin phosphate. After secular equilibrium is reached in about ten minutes, Ag-109m may be selectively eluted from the column by means of a physiologically acceptable aqueous buffered eluent solution of sodium thiosulfate, and either ascorbic acid or dextrose. The breakthrough of toxic Cd-109 is on the order of 1.times.10.sup.-7, which is sufficiently low to permit administration of the Ag-109m-containing eluate, with but a minor pH adjustment, directly to a human patient within a matter of seconds.

Biomedical silver-109m isotope generator

DOEpatents

Wanek, P.M.; Steinkruger, F.J.; Moody, D.C.

1985-03-05

A method, composition of matter, and apparatus for producing substantially pure Ag-109m for use in biomedical imaging techniques. Cd-109, which decays with a half-life of 453 days to Ag-109m, is loaded onto an ion exchange column consisting of particulate tin phosphate. After secular equilibrium is reached in about ten minutes, Ag-109m may be selectively eluted from the column by means of a physiologically acceptable aqueous buffered eluent solution of sodium thiosulfate, and either ascorbic acid or dextrose. The breakthrough of toxic Cd-109 is on the order of 1 x 10-7, which is sufficiently low to permit administration of the Ag-109m-containing eluate, with but a minor pH adjustment, directly to a human patient within a matter of seconds. 1 fig.

Survey on composition and bioconcentration potential of 12 metallic elements in King Bolete (Boletus edulis) mushroom that emerged at 11 spatially distant sites.

PubMed

Falandysz, Jerzy; Frankowska, Aneta; Jarzynska, Grazyna; Dryzałowska, Anna; Kojta, Anna K; Zhang, Dan

2011-01-01

This paper provides data on baseline concentrations, interrelationships and bioconcentration potential of 12 metallic elements by King Bolete collected from 11 spatially distant sites across Poland. There are significant differences in concentrations of metals (Al, Ba, Ca, Cd, Cu, Fe, K, Mg, Mn, Na, Sr, Zn) and their bioconcentration potential in King Bolete Boletus edulis at 11 spatially distant sites surveyed across Poland. These have resulted from significant geographical differences in trace metal concentrations in a layer (0-10 cm) of organic and mineral soil underneath to fruiting bodies and possible local bioavailabilities of macro- (Ca, K, Mg, Na) and trace metals (Al, Ba, Cd, Cu, Fe, Mn, Sr, Zn) to King Bolete. The use of highly appreciated wild-grown edible King Bolete mushroom has established a baseline measure of regional minerals status, heavy metals pollution and assessment of intake rates for wild mushroom dish fanciers against which future changes can be compared. Data on Cd, Cu and Zn from this study and from literature search can be useful to set the maximum limit of these metals in King Bolete collected from uncontaminated (background) areas. In this report also reviewed are data on Al, Ba, Ca, Cd, Cu, Fe, K, Mg, Mn, Na, Sr and Zn accumulation in King Bolete.

Multi-element study of sediments from the river Khai River - Nha Trang Bay estuarine system, South China Sea.

NASA Astrophysics Data System (ADS)

Koukina, Sofia; Lobus, Nikolai; Peresypkin, Valery; Baturin, Gleb; Smurov, Andrey

2013-04-01

Major (Al, Fe, Ti, Mg, Ca, Na, K), minor (Mn) and trace (Cr, Ni, Cd, V, Zn, Cu, Pb, Sb, Bi, Sn, Ag, Li, Co, As, Zr, Mo, Hg) elements along with nutrients (TOC, TS, TP) and TIC were first determined in ten surface sediment samples from the Khai River - Nha Trang Bay estuarine system, South China Sea. According to the sediment quality guidelines and reference background values, most of the element contents that were studied were below the threshold levels, while the content of Ag exceeded significantly the hazardous levels in the most of the samples along the river - sea transect. The local anthropogenic and/or environmental sources of Ag within the region need special study. Aluminum and lithium normalization indicated some specific features in the abundance and distribution of the elements along the salinity gradient. The mean grain size of the sediments decreased from the river part to the bay part of the transect. Sedimentary TOC was relatively low (1-2 %) and showed independent distribution along the river - sea transect in relation to the other elements that were studied. Ca, Ba and Sr distribution showed some sporadic enrichment and were largely controlled by the TIC content in sediments. Sedimentary TP, Al, Fe, Mn, Ti, Na, K, Li, Co, Cs, Zn and V varied within the narrow range and tended to increase seaward. These elements are most likely controlled by the accumulation of their fine grained aluminosilicate host minerals and materials at sites determined by hydrodynamic conditions, i. e., in the sea floor depression. TS, As, Sn, Bi, U, Cd and Mo were relatively low in the sediments studied and tended to decrease seaward with the slight elevation in the intermediate part of the transect. These elements can be scavenged by and/or co-precipitated with the dissolved and particulate materials of the river discharge and further deposited on the river - sea geochemical barrier in the course of estuarine sedimentation. The distribution of Ni, Cr, Zr Cu, Pb, Sb, Hg and, especially, Ag was characterized by anomalous high concentrations in the intermediate part of the river - sea transect at sites located in the harbor zone. This might be due to the point anthropogenic pollution from local human activities, i.e., fishing, shipping, fueling, waste and sewage sludge outflow, and, especially, from the construction of new touristic facilities in the Nha Trang Bay. Overall, the abundance and distribution of the environmental/anthropogenic elements are controlled by various estuarine biogeochemical processes characteristic for the marginal filter of the estuarine water mixing zone.

Kinetic determinations of trace element bioaccumulation in the mussel Mytilus edulis

USGS Publications Warehouse

Wang, W.-X.; Fisher, N.S.; Luoma, S.N.

1996-01-01

Laboratory experiments employing radiotracer methodology were conducted to determine the assimilation efficiencies from ingested natural seston, the influx rates from the dissolved phase and the efflux rates of 6 trace elements (Ag, Am, Cd, Co, Se and Zn) in the mussel Mytilus edulis. A kinetic model was then employed to predict trace element concentration in mussel tissues in 2 locations for which mussel and environmental data are well described: South San Francisco Bay (California, USA) and Long Island Sound (New York, USA). Assimilation efficiencies from natural seston ranged from 5 to 18% for Ag, 0.6 to 1% for Am, 8 to 20% for Cd, 12 to 16% for Co, 28 to 34% for Se, and 32 to 41% for Zn. Differences in chlorophyll a concentration in ingested natural seston did not have significant impact on the assimilation of Am, Co, Se and Zn. The influx rate of elements from the dissolved phase increased with the dissolved concentration, conforming to Freundlich adsorption isotherms. The calculated dissolved uptake rate constant was greatest for Ag, followed by Zn > Am = Cd > Co > Se. The estimated absorption efficiency from the dissolved phase was 1.53% for Ag, 0.34% for Am, 0.31% for Cd, 0.11% for Co, 0.03% for Se and 0.89% for Zn. Salinity had an inverse effect on the influx rate from the dissolved phase and dissolved organic carbon concentration had no significant effect on trace element uptake. The calculated efflux rate constants for all elements ranged from 1.0 to 3.0% d-1. The route of trace element uptake (food vs dissolved) and the duration of exposure to dissolved trace elements (12 h vs 6 d) did not significantly influence trace element efflux rates. A model which used the experimentally determined influx and efflux rates for each of the trace elements, following exposure from ingested food and from water, predicted concentrations of Ag, Cd, Se and Zn in mussels that were directly comparable to actual tissue concentrations independently measured in the 2 reference sites in national monitoring programs. Sensitivity analysis indicated that the total suspended solids load, which can affect mussel feeding activity, assimilation, and trace element concentration in the dissolved and particulate phases, can significantly influence metal bioaccumulation for particle-reactive elements such as Ag and Am. For all metals, concentrations in mussels are proportionately related to total metal load in the water column and their assimilation efficiency from ingested particles. Further, the model predicted that over 96% of Se in mussels is obtained from ingested food, under conditions typical of coastal waters. For Ag, Am, Cd, Co and Zn, the relative contribution from the dissolved phase decreases significantly with increasing trace element partition coefficients for suspended particles and the assimilation efficiency in mussels of ingested trace elements; values range between 33 and 67% for Ag, 5 and 17% for Am, 47 and 82% for Cd, 4 and 30% for Co, and 17 and 51% for Zn.

Molecular glues for manipulating enzymes: trypsin inhibition by benzamidine-conjugated molecular glues† †Electronic supplementary information (ESI) available: Synthesis of TEG–BA, Gluen–BA, mGluen–BA and Gluen–Ph; 1H NMR, 13C NMR, MALDI-TOF MS, electronic absorption, and CD spectra; zeta potential distributions; SLS plots; DLS histograms; and related experimental procedures. See DOI: 10.1039/c5sc00524h Click here for additional data file.

PubMed Central

Mogaki, Rina

2015-01-01

Water-soluble bioadhesive polymers bearing multiple guanidinium ion (Gu+) pendants at their side-chain termini (Gluen–BA, n = 10 and 29) that were conjugated with benzamidine (BA) as a trypsin inhibitor were developed. The Gluen–BA molecules are supposed to adhere to oxyanionic regions of the trypsin surface, even in buffer, via a multivalent Gu+/oxyanion salt-bridge interaction, such that their BA group properly blocks the substrate-binding site. In fact, Glue10–BA and Glue29–BA exhibited 35- and 200-fold higher affinities for trypsin, respectively, than a BA derivative without the glue moiety (TEG–BA). Most importantly, Glue10–BA inhibited the protease activity of trypsin 13-fold more than TEG–BA. In sharp contrast, mGlue27–BA, which bears 27 Gu+ units along the main chain and has a 5-fold higher affinity than TEG–BA for trypsin, was inferior even to TEG–BA for trypsin inhibition. PMID:28706668

Persistence, immune specificity, and functional ability of murine mutant ras epitope-specific CD4(+) and CD8(+) T lymphocytes following in vivo adoptive transfer.

PubMed

Bristol, J A; Schlom, J; Abrams, S I

1999-05-25

Adoptive T-cell transfer has been shown to be a potentially effective strategy for cellular immunotherapy in some murine models of disease. However, several issues remain unresolved regarding some of the basic features involved in effective adoptive transfer, such as the influence of specific peptide antigen (Ag) boost after T-cell transfer, the addition of IL-2 post-T-cell transfer, the trafficking of transferred T cells to lymphoid and nonlymphoid tissues, and the functional stability of recoverable CD4(+) and CD8(+) T cells. We investigated several of these parameters, particularly as they relate to the persistence and maintenance of effector functions of murine CD4(+) and/or CD8(+) T lymphocytes after adoptive cellular transfer into partially gamma-irradiated syngeneic hosts. Our laboratory previously identified murine (H-2(d)) immunogenic CD4(+) and CD8(+) T-cell peptide epitopes reflecting codon 12 ras mutations as tumor-specific Ag. Therefore, the model system chosen here employed epitope-specific MHC class II-restricted CD4(+) T cells and MHC class I-restricted CD8(+) T cells produced from previously immunized BALB/c mice. Between 2 and 7 days after T-cell transfer, recipient mice received various combinations of peptide boosts and/or IL-2 treatments. At different times after the T-cell transfer, spleen and lung tissues were analyzed phenotypically to monitor the persistence of the immune T cells and functionally (via proliferation or cytotoxicity assays) to assess the maintenance of peptide specificity. The results showed that immune donor T lymphocytes (uncultured immune T cells or cloned T cells) were recoverable from the spleens and lungs of recipient mice after transfer. The recovery of Ag-specific T-cell responses was greatest from recipient mice that received peptide boosts and IL-2 treatment. However, mice that received a peptide boost without IL-2 treatment responded nearly as well, which suggested that including a peptide boost after T-cell transfer was more obligatory than exogenous IL-2 treatment to sustain adoptively transferred T cells in vivo. Ag-specific T-cell responses were weak in mice that either received IL-2 alone or did not receive the cognate peptide boost after T-cell transfer. The T-cell clones were also monitored by flow cytometry or RT-PCR based on expression of the T-cell receptor Vbeta-chain, which was previously characterized. Ag-specific T cells were recovered from both spleens and lungs of recipient mice, demonstrating that the T-cell clones could localize to both lymphoid and nonlymphoid tissues. This study demonstrates that both uncultured and in vitro-cloned T lymphocytes can migrate to lymphoid tissues and nonlymphoid (e.g., lung) tissues in recipient hosts and that their functional activities can be maintained at these sites after transfer, if they are exposed to peptide Ag in vivo. Copyright 1999 Academic Press.

The performance of moss, grass, and 1- and 2-year old spruce needles as bioindicators of contamination: a comparative study at the scale of the Czech Republic.

PubMed

Suchara, Ivan; Sucharova, Julie; Hola, Marie; Reimann, Clemens; Boyd, Rognvald; Filzmoser, Peter; Englmaier, Peter

2011-05-01

Moss (Pleurozium schreberi), grass (Avenella flexuosa), and 1- and 2-year old spruce (Picea abies) needles were collected over the territory of the Czech Republic at an average sample density of 1 site per 290km(2). The samples were analysed for 39 elements (Ag, Al, As, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, Ga, Hg, K, La, Li, Mg, Mn, Mo, Na, Nd, Ni, Pb, Pr, Rb, S, Sb, Se, Sn, Sr, Th, Tl, U, V, Y and Zn) using ICP-MS and ICP-AES techniques (the major nutrients Ca, K, Mg and Na were not analysed in moss). Moss showed by far the highest element concentrations for most elements. Exceptions were Ba (spruce), Mn (spruce), Mo (grass), Ni (spruce), Rb (grass) and S (grass). Regional distribution maps and spatial trend analysis were used to study the suitability of the four materials as bioindicators of anthropogenic contamination. The highly industrialised areas in the north-west and the far east of the country and several more local contamination sources were indicated in the distribution maps of one or several sample materials. At the scale of the whole country moss was the best indicator of known contamination sources. However, on a more local scale, it appeared that spruce needles were especially well suited for detection of urban contamination. Copyright © 2010 Elsevier B.V. All rights reserved.

Dependence of precipitation of trace elements on pH in standard water

NASA Astrophysics Data System (ADS)

Verma, Shivcharan; Mohanty, Biraja P.; Singh, K. P.; Behera, B. R.; Kumar, Ashok

2018-04-01

The present work aimed to study the dependence of precipitation of trace elements on the pH of solution. A standard solution was prepared by using ultrapure deionized water (18.2 MΩ/cm) as the solvent and 11 water-soluble salts having different elements as solutes. Five samples of different pH values (2 acidic, 2 basic, and 1 neutral) were prepared from this standard solution. Sodium-diethyldithiocarbamate was used as the chelating agent to precipitate the metal ions present in these samples of different pH values. The targets were prepared by collecting these precipitates on mixed cellulose esters filter of 0.4 μm pore size by vacuum filtration. Elemental analysis of these targets was performed by particle-induced X-ray emission (PIXE) using 2.7 MeV protons from the single Dee variable energy cyclotron at Panjab University, Chandigarh, India. PIXE data were analyzed using GUPIXWIN software. For most of the elements, except Hg with oxidation state +2, such as Co, Ni, Zn, Ba, and Cd, a general trend of enhancement in precipitation was observed with the increase in pH. However, for other elements such as V, As, Mo, Ag, and Bi, which have oxidation state other than +2, no definite pattern was observed. Precipitation of Ba and As using this method was negligible at all five pH values. From these results, it can be concluded that the precipitation and recovery of elements depend strongly on the pH of the water sample.

Structural and luminescent study of TeO2-BaO-Bi2O3-Ag glass system doped with Eu3+ and Dy3+ for possible color-tunable phosphor application

NASA Astrophysics Data System (ADS)

Lewandowski, Tomasz; Seweryński, Cezary; Walas, Michalina; Łapiński, Marcin; Synak, Anna; Sadowski, Wojciech; Kościelska, Barbara

2018-05-01

Tellurite glass systems of 73TeO2-4BaO-3Bi2O3-1Ag:xEu2O3-(2-x)Dy2O3 (where x = 0.5, 1, 1.5, 2 in molar ratio) composition have been successfully synthesized. In order to acquire Ag nanoparticles, materials have been heat treated at 350 °C in the air atmosphere. Structural properties of obtained samples were evaluated with various techniques. X-Ray Diffraction (XRD) measurements indicated that obtained materials are amorphous in nature. UV-vis results presented transitions characteristic to Dy3+ and Eu3+ ions. Additionally, X-Ray Photoelectron Spectroscopy (XPS) analysis indicated the presence of silver in metallic form. Photoluminescence measurements shown influence of Ag nanoparticles on emission characteristics. Simultaneous emission of Dy3+ and Eu3+ has been observed when samples were excited with λexc = 390 nm. Change of the emission color induced by heat treatment has been observed and described in case of x = 1 glass series. According to CIE results emission color changes as Eu/Dy ratio and heat treatment time are changed. Emission shifts from reddish-orange to yellowish white color. Obtained photoluminescence results confirm that synthesized materials are good candidates for color tunable phosphors.

Work function and quantum efficiency study of metal oxide thin films on Ag(100)

NASA Astrophysics Data System (ADS)

Chang, V.; Noakes, T. C. Q.; Harrison, N. M.

2018-04-01

Increasing the quantum efficiency (QE) of metal photocathodes is in the design and development of photocathodes for free-electron laser applications. The growth of metal oxide thin films on certain metal surfaces has previously been shown to reduce the work function (WF). Using a photoemission model B. Camino et al. [Comput. Mater. Sci. 122, 331 (2016), 10.1016/j.commatsci.2016.05.025] based on the three-step model combined with density functional theory calculations we predict that the growth of a finite number of MgO(100) or BaO(100) layers on the Ag(100) surface increases significantly the QE compared with the clean Ag(100) surface for a photon energy of 4.7 eV. Different mechanisms for affecting the QE are identified for the different metal oxide thin films. The addition of MgO(100) increases the QE due to the reduction of the WF and the direct excitation of electrons from the Ag surface to the MgO conduction band. For BaO(100) thin films, an additional mechanism is in operation as the oxide film also photoemits at this energy. We also note that a significant increase in the QE for photons with an energy of a few eV above the WF is achieved due to an increase in the inelastic mean-free path of the electrons.

The oscillations in ESR spectra of Hg0.76Cd0.24Te implanted by Ag+ at the X and Q-bands

NASA Astrophysics Data System (ADS)

Shestakov, A. V.; Fazlizhanov, I. I.; Yatsyk, I. V.; Gilmutdinov, I. F.; Ibragimova, M. I.; Shustov, V. A.; Eremina, R. M.

2018-05-01

The objects of the investigation were uniformly Ag+ doped Hg0.76Cd0.24Te mercury chalcogenide monocrystals obtained by ion implantation with subsequent thermal annealing over 20 days. After implantation and annealing the conductivity was inverted from n-type with carrier concentration of 1016 cm‑3 to p-type with carrier concentration of ≈ 3.9 × 1015 cm‑3. The investigations of microwave absorption derivative (dP/dH) showed the existence of strong oscillations in the magnetic field for Ag:Hg0.76Cd0.24Te in the temperature range 4.2–12 K. The concentration and effective mass of charge carrier were determined from oscillation period and temperature dependency of oscillation amplitude. We suppose that this phenomenon is similar to the de Haas–van Alphen effect in weakly correlated electron system with imperfect nesting vector.

Subcellular distribution of trace elements in the liver of sea turtles.

PubMed

Anan, Yasumi; Kunito, Takashi; Sakai, Haruya; Tanabe, Shinsuke

2002-01-01

Subcellular distribution of Cu, Zn, Se, Rb, Mo, Ag, Cd and Pb was determined in the liver of green turtles (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata) from Yaeyama Islands, Japan. Also, hepatic cytosol from sea turtles was applied on a Sephadex G-75 column and elution profiles of trace elements were examined. Copper, Zn, Se, Rb, Ag and Cd were largely present in cytosol in the liver of both species, indicating that cytosol was the significant site for the accumulation of these elements in sea turtles. In contrast, Mo and Pb were accumulated specifically in nuclear and mitochondrial fraction and microsomal fraction, respectively. Gel filtration analysis showed that Cu, Zn, Ag and Cd were bound to metallothionein (MT) in the cytosol of sea turtles. To our knowledge, this is the first report on the association of trace elements with MT in sea turtles.

Effect of Silicon on Activity Coefficients of P, Bl, CD, SN, and AG in Liquid Fe-Si, and Implications for Differentiation and Core Formation

NASA Technical Reports Server (NTRS)

Righter, K.; Pando, K.; Ross, D. K.

2017-01-01

Cores of differentiated bodies (Earth, Mars, Mercury, Moon, Vesta) contain light elements such as S, C, Si, and O. We have previously measured small effects of Si on metal-silicate partitioning of Ni and Co [1,2], and larger effects for Mo, Ge, Sb, As [2]. The effect of Si on many siderophile elements could be an important, and as yet unquantified, influence on the core-mantle partitioning of SE. Here we report new experiments designed to quantify the effect of Si on the partitioning of Bi, Cd, Sn, Ag, and P between metal and silicate melt. The results will be applied to Earth, Mars, Mercury, Moon, and Vesta, for which we have excellent constraints on the mantle Bi, Cd, Sn, Ag, and P concentrations from mantle and/or basalt samples.

Effect of Silicon on Activity Coefficients of P, Bi, Cd, Sn, and Ag in Liquid Fe-Si, and Implications for Core Formation

NASA Technical Reports Server (NTRS)

Righter, K.; Pando, K.; Ross, D. K.; Righter, M.; Lapen, T. J.

2018-01-01

Cores of differentiated bodies (Earth, Mars, Mercury, Moon, Vesta) contain light elements such as S, C, Si, and O. We have previously measured small effects of Si on Ni and Co, and larger effects on Mo, Ge, Sb, As metal/silicate partitioning. The effect of Si on metal-silicate partitioning has been quantified for many siderophile elements, but there are a few key elements for which the effects are not yet quantified. Here we report new experiments designed to quantify the effect of Si on the partitioning of Bi, Cd, Sn, Ag, and P between metal and silicate melt. The results will be applied to Earth, Mars, Moon, and Vesta, for which we have good constraints on the mantle Bi, Cd, Sn, Ag, and P concentrations from mantle and/or basalt samples.

Materials Data on BaAg2SnSe4 (SG:23) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-10

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

Materials Data on BaAg2SnS4 (SG:23) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

Materials Data on BaAg2GeSe4 (SG:23) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-10

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

Materials Data on BaAg(PO3)3 (SG:19) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

Ability of the marine bacterium Pseudomonas fluorescens BA3SM1 to counteract the toxicity of CdSe nanoparticles.

PubMed

Poirier, Isabelle; Kuhn, Lauriane; Demortière, Arnaud; Mirvaux, Boris; Hammann, Philippe; Chicher, Johana; Caplat, Christelle; Pallud, Marie; Bertrand, Martine

2016-10-04

In the marine environment, bacteria from estuarine and coastal sediments are among the first targets of nanoparticle pollution; it is therefore relevant to improve the knowledge of interactions between bacteria and nanoparticles. In this work, the response of the marine bacterium Pseudomonas fluorescens BA3SM1 to CdSe nanocrystals (CdSe NPs) of 3nm (NP3) and 8nm (NP8) in diameter was evaluated through microscopic, physiological, biochemical and proteomic approaches. Transmission electron microscopy images showed that NP3 were able to penetrate the bacteria, while NP8 were highly concentrated around the cells, embedded in large exopolysaccharides. In our experimental conditions, both CdSe NP sizes induced a decrease in respiration during the stationary growth phase, while only NP8 caused growth retardation and a decrease in pyoverdine production. Proteomic analyses highlighted that the strain responded to CdSe NP toxicity by inducing various defence mechanisms such as cell aggregation, extracellular CdSe NP sequestration, effective protection against oxidative stress, modifications of envelope organization and properties, and cadmium export. In addition, BA3SM1 presented a biosorption capacity of 1.6×10(16)NP3/g dry weight and 1.7×10(15)NP8/g dry weight. This strain therefore appears as a promising agent for NP bioremediation processes. Proteomic data are available via ProteomeXchange with identifier PXD004012. To the best of our knowledge, this is the first report focussing on the effects of CdSe colloidal nanocrystals (CdSe NPs) on a marine strain of Pseudomonas fluorescens. CdSe NPs are extensively used in the industry of renewable energies and it is regrettably expected that these pollutants will sometime soon appear in the marine environment through surface runoff, urban effluents and rivers. Bacteria living in estuarine and coastal sediments will be among the first targets of these new pollutants. The pseudomonads are frequently found in these ecosystems. They are involved in several biogeochemical cycles and are known for their high resistance to pollutants. Consequently, this study focussing on the effects of CdSe NPs on the marine strain P. fluorescens BA3SM1 is highly relevant for several reasons. First, it aims at improving knowledge about the interactions between bacteria and NPs. This is fundamental to effectively use NPs against pathogenic bacteria. Secondly, in spite of CdSe NP interactions with the bacterial cells, the strain BA3SM1 can develop various strategies to counteract CdSe NP toxicity and ensure its growth. It exhibits interesting properties to sequester CdSe NPs and it retains its ability to form biofilm. The strain therefore appears as a promising agent for NP bioremediation thanks to biofiltration processes. Finally, this study shows that CdSe NPs of 8nm in diameter cause a decrease in the secretion of siderophore pyoverdine, a secondary metabolite playing a key role in microbial ecology since it drives bacterial survival and competitiveness in ecosystems. Bacteria producing effective siderophores survive better in a Fe-deficient environment where they antagonize the growth of other microbes thought iron deprivation. Furthermore, siderophores are also employed as virulence factors in human pathogenic strains such as P. aeruginosa. Consequently, this study highlights that NPs can impact the secondary metabolism of bacteria with environmental and medical implications. In addition, in this work, Data-Dependant Acquisition (DDA) provided state of the art Mass Spectrometry data by Spectral Counting and MS1 Label-Free. The combination of these two well-known proteomic techniques including manual validations strengthened the identification and quantification of regulated proteins. Moreover, numerous correlations between proteomic analyses and other observations (physiological, biochemical, microscopic) consolidated our interpretations. Copyright © 2016 Elsevier B.V. All rights reserved.

Screening HIV-Infected Patients with Low CD4 Counts for Cryptococcal Antigenemia prior to Initiation of Antiretroviral Therapy: Cost Effectiveness of Alternative Screening Strategies in South Africa.

PubMed

Larson, Bruce A; Rockers, Peter C; Bonawitz, Rachael; Sriruttan, Charlotte; Glencross, Deborah K; Cassim, Naseem; Coetzee, Lindi M; Greene, Gregory S; Chiller, Tom M; Vallabhaneni, Snigdha; Long, Lawrence; van Rensburg, Craig; Govender, Nelesh P

2016-01-01

In 2015 South Africa established a national cryptococcal antigenemia (CrAg) screening policy targeted at HIV-infected patients with CD4+ T-lymphocyte (CD4) counts <100 cells/ μl who are not yet on antiretroviral treatment (ART). Two screening strategies are included in national guidelines: reflex screening, where a CrAg test is performed on remnant blood samples from CD4 testing; and provider-initiated screening, where providers order a CrAg test after a patient returns for CD4 test results. The objective of this study was to compare costs and effectiveness of these two screening strategies. We developed a decision analytic model to compare reflex and provider-initiated screening in terms of programmatic and health outcomes (number screened, number identified for preemptive treatment, lives saved, and discounted years of life saved) and screening and treatment costs (2015 USD). We estimated a base case with prevalence and other parameters based on data collected during CrAg screening pilot projects integrated into routine HIV care in Gauteng, Free State, and Western Cape Provinces. We conducted sensitivity analyses to explore how results change with underlying parameter assumptions. In the base case, for each 100,000 CD4 tests, the reflex strategy compared to the provider-initiated strategy has higher screening costs ($37,536 higher) but lower treatment costs ($55,165 lower), so overall costs of screening and treatment are $17,629 less with the reflex strategy. The reflex strategy saves more lives (30 lives, 647 additional years of life saved). Sensitivity analyses suggest that reflex screening dominates provider-initiated screening (lower total costs and more lives saved) or saves additional lives for small additional costs (< $125 per life year) across a wide range of conditions (CrAg prevalence, patient and provider behavior, patient survival without treatment, and effectiveness of preemptive fluconazole treatment). In countries with substantial numbers of people with untreated, advanced HIV disease such as South Africa, CrAg screening before initiation of ART has the potential to reduce cryptococcal meningitis and save lives. Reflex screening compared to provider-initiated screening saves more lives and is likely to be cost saving or have low additional costs per additional year of life saved.

Screening HIV-Infected Patients with Low CD4 Counts for Cryptococcal Antigenemia prior to Initiation of Antiretroviral Therapy: Cost Effectiveness of Alternative Screening Strategies in South Africa

PubMed Central

Rockers, Peter C.; Bonawitz, Rachael; Sriruttan, Charlotte; Glencross, Deborah K.; Cassim, Naseem; Coetzee, Lindi M.; Greene, Gregory S.; Chiller, Tom M.; Vallabhaneni, Snigdha; Long, Lawrence; van Rensburg, Craig; Govender, Nelesh P.

2016-01-01

Background In 2015 South Africa established a national cryptococcal antigenemia (CrAg) screening policy targeted at HIV-infected patients with CD4+ T-lymphocyte (CD4) counts <100 cells/ μl who are not yet on antiretroviral treatment (ART). Two screening strategies are included in national guidelines: reflex screening, where a CrAg test is performed on remnant blood samples from CD4 testing; and provider-initiated screening, where providers order a CrAg test after a patient returns for CD4 test results. The objective of this study was to compare costs and effectiveness of these two screening strategies. Methods We developed a decision analytic model to compare reflex and provider-initiated screening in terms of programmatic and health outcomes (number screened, number identified for preemptive treatment, lives saved, and discounted years of life saved) and screening and treatment costs (2015 USD). We estimated a base case with prevalence and other parameters based on data collected during CrAg screening pilot projects integrated into routine HIV care in Gauteng, Free State, and Western Cape Provinces. We conducted sensitivity analyses to explore how results change with underlying parameter assumptions. Results In the base case, for each 100,000 CD4 tests, the reflex strategy compared to the provider-initiated strategy has higher screening costs ($37,536 higher) but lower treatment costs ($55,165 lower), so overall costs of screening and treatment are $17,629 less with the reflex strategy. The reflex strategy saves more lives (30 lives, 647 additional years of life saved). Sensitivity analyses suggest that reflex screening dominates provider-initiated screening (lower total costs and more lives saved) or saves additional lives for small additional costs (< $125 per life year) across a wide range of conditions (CrAg prevalence, patient and provider behavior, patient survival without treatment, and effectiveness of preemptive fluconazole treatment). Conclusions In countries with substantial numbers of people with untreated, advanced HIV disease such as South Africa, CrAg screening before initiation of ART has the potential to reduce cryptococcal meningitis and save lives. Reflex screening compared to provider-initiated screening saves more lives and is likely to be cost saving or have low additional costs per additional year of life saved. PMID:27390864

Active chinese mistletoe lectin-55 enhances colon cancer surveillance through regulating innate and adaptive immune responses

PubMed Central

Ma, Yan-Hui; Cheng, Wei-Zhi; Gong, Fang; Ma, An-Lun; Yu, Qi-Wen; Zhang, Ji-Ying; Hu, Chao-Ying; Chen, Xue-Hua; Zhang, Dong-Qing

2008-01-01

AIM: To investigate the potential role of Active Chinese mistletoe lectin-55 (ACML-55) in tumor immune surveillance. METHODS: In this study, an experimental model was established by hypodermic inoculating the colon cancer cell line CT26 (5 × 105 cells) into BALB/c mice. The experimental treatment was orally administered with ACML-55 or PBS, followed by the inoculation of colon cancer cell line CT26. Intracellular cytokine staining was used to detect IFN-γ production by tumor antigen specific CD8+ T cells. FACS analysis was employed to profile composition and activation of CD4+, CD8+, γδ T and NK cells. RESULTS: Our results showed, compared to PBS treated mice, ACML-55 treatment significantly delayed colon cancer development in colon cancer -bearing Balb/c mice in vivo. Treatment with ACML-55 enhanced both Ag specific activation and proliferation of CD4+ and CD8+ T cells, and increased the number of tumor Ag specific CD8+ T cells. It was more important to increase the frequency of tumor Ag specific IFN-γ producing-CD8+ T cells. Interestingly, ACML-55 treatment also showed increased cell number of NK, and γδT cells, indicating the role of ACML-55 in activation of innate lymphocytes. CONCLUSION: Our results demonstrate that ACML-55 therapy can enhance function in immune surveillance in colon cancer-bearing mice through regulating both innate and adaptive immune responses. PMID:18785279

CD22 is required for formation of memory B cell precursors within germinal centers.

PubMed

Chappell, Craig P; Draves, Kevin E; Clark, Edward A

2017-01-01

CD22 is a BCR co-receptor that regulates B cell signaling, proliferation and survival and is required for T cell-independent Ab responses. To investigate the role of CD22 during T cell-dependent (TD) Ab responses and memory B cell formation, we analyzed Ag-specific B cell responses generated by wild-type (WT) or CD22-/- B cells following immunization with a TD Ag. CD22-/- B cells mounted normal early Ab responses yet failed to generate either memory B cells or long-lived plasma cells, whereas WT B cells formed both populations. Surprisingly, B cell expansion and germinal center (GC) differentiation were comparable between WT and CD22-/- B cells. CD22-/- B cells, however, were significantly less capable of generating a population of CXCR4hiCD38hi GC B cells, which we propose represent memory B cell precursors within GCs. These results demonstrate a novel role for CD22 during TD humoral responses evident during primary GC formation and underscore that CD22 functions not only during B cell maturation but also during responses to both TD and T cell-independent antigens.

CD22 is required for formation of memory B cell precursors within germinal centers

PubMed Central

Chappell, Craig P.; Draves, Kevin E.

2017-01-01

CD22 is a BCR co-receptor that regulates B cell signaling, proliferation and survival and is required for T cell-independent Ab responses. To investigate the role of CD22 during T cell-dependent (TD) Ab responses and memory B cell formation, we analyzed Ag-specific B cell responses generated by wild-type (WT) or CD22-/- B cells following immunization with a TD Ag. CD22-/- B cells mounted normal early Ab responses yet failed to generate either memory B cells or long-lived plasma cells, whereas WT B cells formed both populations. Surprisingly, B cell expansion and germinal center (GC) differentiation were comparable between WT and CD22-/- B cells. CD22-/- B cells, however, were significantly less capable of generating a population of CXCR4hiCD38hi GC B cells, which we propose represent memory B cell precursors within GCs. These results demonstrate a novel role for CD22 during TD humoral responses evident during primary GC formation and underscore that CD22 functions not only during B cell maturation but also during responses to both TD and T cell-independent antigens. PMID:28346517

Bioavailability of particle-associated silver, cadmium, and zinc to the estuarine amphipod Leptocheirus plumulosus through dietary ingestion

USGS Publications Warehouse

Schlekat, C.E.; Decho, Alan W.; Chandler, G.T.

2000-01-01

We conducted experiments to determine effects of particle type on assimilatory metal bioavailability to Leptocheirus plumulosus, an infaunal, estuarine amphipod that is commonly used in sediment toxicity tests. The following particles were used to represent natural food items encountered by this surface-deposit and suspension-feeding amphipod: bacterial exopolymeric sediment coatings, polymeric coatings made from Spartina alterniflora extract, amorphous iron oxide coatings, the diatom Phaeodactylum tricornutum, the chlorophyte Dunaliella tertiolecta, processed estuarine sediment, and fresh estuarine sediment. Bioavailability of the gamma-emitting radioisotopes 110mAg, 109Cd, and 65Zn was measured as the efficiency with which L. plumulosus assimilated metals from particles using pulse-chase methods. Ag and Cd assimilation efficiencies were highest from bacterial exopolymeric coatings. Zn assimilation efficiency exhibited considerable interexperimental variation; the highest Zn assimilation efficiencies were measured from phytoplankton and processed sediment. In general, Ag and Cd assimilation efficiencies from phytoplankton were low and not related to the proportion of metal associated with cell cytosol or cytoplasm, a phenomenon reported for other particle-ingesting invertebrates. Amphipod digestive processes explain differences in Ag and Cd assimilation efficiencies between exopolymeric coatings and phytoplankton. Results highlight the importance of labile polymeric organic carbon sediment coatings in dietary metals uptake by this benthic invertebrate, rather than recalcitrant organic carbon, mineralogical features such as iron oxides, or phytoplankton.

Cryptococcal antigen screening by lay cadres using a rapid test at the point of care: A feasibility study in rural Lesotho.

PubMed

Rick, Fernanda; Niyibizi, Aline Aurore; Shroufi, Amir; Onami, Kazumi; Steele, Sarah-Jane; Kuleile, Malehlohonolo; Muleya, Innocent; Chiller, Tom; Walker, Tiffany; Van Cutsem, Gilles

2017-01-01

Cryptococcal meningitis is one of the leading causes of death among people with HIV in Africa, primarily due to delayed presentation, poor availability and high cost of treatment. Routine cryptococcal antigen (CrAg) screening of patients with a CD4 count less than 100 cells/mm3, followed by pre-emptive therapy if positive, might reduce mortality in high prevalence settings. Using the cryptococcal antigen (CrAg) lateral flow assay (LFA), screening is possible at the point of care (POC). However, critical shortages of health staff may limit adoption. This study investigates the feasibility of lay counsellors conducting CrAg LFA screening in rural primary care clinics in Lesotho. From May 2014 to June 2015, individuals who tested positive for HIV were tested for CD4 count and those with CD4 <100 cells/mm3 were screened with CrAg LFA. All tests were performed by lay counsellors. CrAg-positive asymptomatic patients received fluconazole, while symptomatic patients were referred to hospital. Lay counsellors were trained and supervised by a laboratory technician and counsellor activity supervisor. Additionally, nurses and doctors were trained on CrAg screening and appropriate treatment. During the study period, 1,388 people were newly diagnosed with HIV, of whom 129 (9%) presented with a CD4 count <100 cells/mm3. Of these, 128 (99%) were screened with CrAg LFA and 14/128 (11%) tested positive. Twelve of the 14 (86%) were asymptomatic, and received outpatient fluconazole. All commenced ART with a median time to initiation of 15.5 days [IQR: 14-22]. Of the asymptomatic patients, nine (75%) remained asymptomatic after a median time of 5 months [IQR; 3-6] of follow up. One (8%) became co-infected with tuberculosis and died and two were transferred out. The two patients with symptomatic cryptococcal meningitis (CM) were referred to hospital, where they later died. CrAg LFA screening by lay counsellors followed by pre-emptive fluconazole treatment for asymptomatic cases, or referral to hospital for symptomatic cases, proved feasible. However, regular follow-up to ensure proper management of cryptococcal disease was needed. These early results support the wider use of CrAg LFA screening in remote primary care settings where upper cadres of healthcare staff may be in short supply.

Cryptococcal antigen screening by lay cadres using a rapid test at the point of care: A feasibility study in rural Lesotho

PubMed Central

Rick, Fernanda; Niyibizi, Aline Aurore; Shroufi, Amir; Onami, Kazumi; Steele, Sarah-Jane; Kuleile, Malehlohonolo; Muleya, Innocent; Chiller, Tom; Walker, Tiffany; Van Cutsem, Gilles

2017-01-01

Introduction Cryptococcal meningitis is one of the leading causes of death among people with HIV in Africa, primarily due to delayed presentation, poor availability and high cost of treatment. Routine cryptococcal antigen (CrAg) screening of patients with a CD4 count less than 100 cells/mm3, followed by pre-emptive therapy if positive, might reduce mortality in high prevalence settings. Using the cryptococcal antigen (CrAg) lateral flow assay (LFA), screening is possible at the point of care (POC). However, critical shortages of health staff may limit adoption. This study investigates the feasibility of lay counsellors conducting CrAg LFA screening in rural primary care clinics in Lesotho. Methods From May 2014 to June 2015, individuals who tested positive for HIV were tested for CD4 count and those with CD4 <100 cells/mm3 were screened with CrAg LFA. All tests were performed by lay counsellors. CrAg-positive asymptomatic patients received fluconazole, while symptomatic patients were referred to hospital. Lay counsellors were trained and supervised by a laboratory technician and counsellor activity supervisor. Additionally, nurses and doctors were trained on CrAg screening and appropriate treatment. Results During the study period, 1,388 people were newly diagnosed with HIV, of whom 129 (9%) presented with a CD4 count <100 cells/mm3. Of these, 128 (99%) were screened with CrAg LFA and 14/128 (11%) tested positive. Twelve of the 14 (86%) were asymptomatic, and received outpatient fluconazole. All commenced ART with a median time to initiation of 15.5 days [IQR: 14–22]. Of the asymptomatic patients, nine (75%) remained asymptomatic after a median time of 5 months [IQR; 3–6] of follow up. One (8%) became co-infected with tuberculosis and died and two were transferred out. The two patients with symptomatic cryptococcal meningitis (CM) were referred to hospital, where they later died. Conclusions CrAg LFA screening by lay counsellors followed by pre-emptive fluconazole treatment for asymptomatic cases, or referral to hospital for symptomatic cases, proved feasible. However, regular follow-up to ensure proper management of cryptococcal disease was needed. These early results support the wider use of CrAg LFA screening in remote primary care settings where upper cadres of healthcare staff may be in short supply. PMID:28877182

PD-1 Blockade Promotes Epitope Spreading in Anticancer CD8+ T Cell Responses by Preventing Fratricidal Death of Subdominant Clones To Relieve Immunodomination.

PubMed

Memarnejadian, Arash; Meilleur, Courtney E; Shaler, Christopher R; Khazaie, Khashayarsha; Bennink, Jack R; Schell, Todd D; Haeryfar, S M Mansour

2017-11-01

The interactions between programmed death-1 (PD-1) and its ligands hamper tumor-specific CD8 + T cell (T CD8 ) responses, and PD-1-based "checkpoint inhibitors" have shown promise in certain cancers, thus revitalizing interest in immunotherapy. PD-1-targeted therapies reverse T CD8 exhaustion/anergy. However, whether they alter the epitope breadth of T CD8 responses remains unclear. This is an important question because subdominant T CD8 are more likely than immunodominant clones to escape tolerance mechanisms and may contribute to protective anticancer immunity. We have addressed this question in an in vivo model of T CD8 responses to well-defined epitopes of a clinically relevant oncoprotein, large T Ag. We found that unlike other coinhibitory molecules (CTLA-4, LAG-3, TIM-3), PD-1 was highly expressed by subdominant T CD8 , which correlated with their propensity to favorably respond to PD-1/PD-1 ligand-1 (PD-L1)-blocking Abs. PD-1 blockade increased the size of subdominant T CD8 clones at the peak of their primary response, and it also sustained their presence, thus giving rise to an enlarged memory pool. The expanded population was fully functional as judged by IFN-γ production and MHC class I-restricted cytotoxicity. The selective increase in subdominant T CD8 clonal size was due to their enhanced survival, not proliferation. Further mechanistic studies utilizing peptide-pulsed dendritic cells, recombinant vaccinia viruses encoding full-length T Ag or epitope mingenes, and tumor cells expressing T Ag variants revealed that anti-PD-1 invigorates subdominant T CD8 responses by relieving their lysis-dependent suppression by immunodominant T CD8 To our knowledge, our work constitutes the first report that interfering with PD-1 signaling potentiates epitope spreading in tumor-specific responses, a finding with clear implications for cancer immunotherapy and vaccination. Copyright © 2017 by The American Association of Immunologists, Inc.

Intranasal boosting with an adenovirus-vectored vaccine markedly enhances protection by parenteral Mycobacterium bovis BCG immunization against pulmonary tuberculosis.

PubMed

Santosuosso, Michael; McCormick, Sarah; Zhang, Xizhong; Zganiacz, Anna; Xing, Zhou

2006-08-01

Parenterally administered Mycobacterium bovis BCG vaccine confers only limited immune protection from pulmonary tuberculosis in humans. There is a need for developing effective boosting vaccination strategies. We examined a heterologous prime-boost regimen utilizing BCG as a prime vaccine and our recently described adenoviral vector expressing Ag85A (AdAg85A) as a boost vaccine. Since we recently demonstrated that a single intranasal but not intramuscular immunization with AdAg85A was able to induce potent protection from pulmonary Mycobacterium tuberculosis challenge in a mouse model, we compared the protective effects of parenteral and mucosal booster immunizations following subcutaneous BCG priming. Protection by BCG prime immunization was not effectively boosted by subcutaneous BCG or intramuscular AdAg85A. In contrast, protection by BCG priming was remarkably boosted by intranasal AdAg85A. Such enhanced protection by intranasal AdAg85A was correlated to the numbers of gamma interferon-positive CD4 and CD8 T cells residing in the airway lumen of the lung. Our study demonstrates that intranasal administration of AdAg85A represents an effective way to boost immune protection by parenteral BCG vaccination.

Notch-ligand expression by NALT dendritic cells regulates mucosal Th1- and Th2-type responses

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

Fukuyama, Yoshiko; Tokuhara, Daisuke; Division of Mucosal Immunology, Institute of Medical Science, University of Tokyo, Tokyo 108-8639

Highlights: Black-Right-Pointing-Pointer Nasal Ad-FL effectively up-regulates APC function by CD11c{sup +} DCs in mucosal tissues. Black-Right-Pointing-Pointer Nasal Ad-FL induces Notch ligand (L)-expressing CD11c{sup +} DCs. Black-Right-Pointing-Pointer Notch L-expressing DCs support the induction of Th1- and Th2-type cytokine responses. -- Abstract: Our previous studies showed that an adenovirus (Ad) serotype 5 vector expressing Flt3 ligand (Ad-FL) as nasal adjuvant activates CD11c{sup +} dendritic cells (DCs) for the enhancement of antigen (Ag)-specific IgA antibody (Ab) responses. In this study, we examined the molecular mechanism for activation of CD11c{sup +} DCs and their roles in induction of Ag-specific Th1- and Th2-cell responses. Ad-FLmore » activated CD11c{sup +} DCs expressed increased levels of the Notch ligand (L)-expression and specific mRNA. When CD11c{sup +} DCs from various mucosal and systemic lymphoid tissues of mice given nasal OVA plus Ad-FL were cultured with CD4{sup +} T cells isolated from non-immunized OVA TCR-transgenic (OT II) mice, significantly increased levels of T cell proliferative responses were noted. Furthermore, Ad-FL activated DCs induced IFN-{gamma}, IL-2 and IL-4 producing CD4{sup +} T cells. Of importance, these APC functions by Ad-FL activated DCs were down-regulated by blocking Notch-Notch-L pathway. These results show that Ad-FL induces CD11c{sup +} DCs to the express Notch-ligands and these activated DCs regulate the induction of Ag-specific Th1- and Th2-type cytokine responses.« less

The potential effect of metallothionein 2A - 5 A/G single nucleotide polymorphism on blood cadmium, lead, zinc and copper levels

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

Kayaalti, Zeliha, E-mail: kayaalti@ankara.edu.tr; Aliyev, Vugar; Soeylemezoglu, Tuelin

2011-10-01

Metallothioneins (MTs) are low molecular weight, cysteine-rich, metal-binding proteins. Because of their rich thiol groups, MTs bind to the biologically essential metals and perform these metals' homeostatic regulations; absorb the heavy metals and assist with their transportation and extraction. The aim of this study was to investigate the association between the metallothionein 2A (MT2A) core promoter region - 5 A/G single nucleotide polymorphism (SNP) and Cd, Pb, Zn and Cu levels in the blood samples. MT2A polymorphism was determined by the standard polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique using the 616 blood samples and the genotype frequencies weremore » found as 86.6% homozygote typical (AA), 12.8% heterozygote (AG) and 0.6% homozygote atypical (GG). Metal levels were analyzed by dual atomic absorption spectrophotometer system and the average levels of Cd, Pb, Zn and Cu in the blood samples were 1.69 {+-} 1.57 ppb, 30.62 {+-} 14.13 ppb, 0.98 {+-} 0.49 ppm and 1.04 {+-} 0.45 ppm, respectively. As a result; highly statistically significant associations were detected between the - 5 A/G core promoter region SNP in the MT2A gene and Cd, Pb and Zn levels (p = 0.004, p = 0.012 and p = 0.002, respectively), but no association was found with Cu level (p = 0.595). Individuals with the GG genotype had statistically lower Zn level and higher Cd and Pb levels in the blood samples than individuals with AA and AG genotypes. This study suggests that having the GG genotype individuals may be more sensitive for the metal toxicity and they should be more careful about protecting their health against the toxic effects of the heavy metals. - Highlights: > MT2A -5A/G SNP has strong effect on the Cd, Pb and Zn levels in the blood. > MT2A GG individuals should be more careful for their health against metal toxicity. > This SNP might be considered as a biomarker for risk of disease related to metals.« less

Infrared emitting and photoconducting colloidal silver chalcogenide nanocrystal quantum dots from a silylamide-promoted synthesis.

PubMed

Yarema, Maksym; Pichler, Stefan; Sytnyk, Mykhailo; Seyrkammer, Robert; Lechner, Rainer T; Fritz-Popovski, Gerhard; Jarzab, Dorota; Szendrei, Krisztina; Resel, Roland; Korovyanko, Oleksandra; Loi, Maria Antonietta; Paris, Oskar; Hesser, Günter; Heiss, Wolfgang

2011-05-24

Here, we present a hot injection synthesis of colloidal Ag chalcogenide nanocrystals (Ag(2)Se, Ag(2)Te, and Ag(2)S) that resulted in exceptionally small nanocrystal sizes in the range between 2 and 4 nm. Ag chalcogenide nanocrystals exhibit band gap energies within the near-infrared spectral region, making these materials promising as environmentally benign alternatives to established infrared active nanocrystals containing toxic metals such as Hg, Cd, and Pb. We present Ag(2)Se nanocrystals in detail, giving size-tunable luminescence with quantum yields above 1.7%. The luminescence, with a decay time on the order of 130 ns, was shown to improve due to the growth of a monolayer thick ZnSe shell. Photoconductivity with a quantum efficiency of 27% was achieved by blending the Ag(2)Se nanocrystals with a soluble fullerene derivative. The co-injection of lithium silylamide was found to be crucial to the synthesis of Ag chalcogenide nanocrystals, which drastically increased their nucleation rate even at relatively low growth temperatures. Because the same observation was made for the nucleation of Cd chalcogenide nanocrystals, we conclude that the addition of lithium silylamide might generally promote wet-chemical synthesis of metal chalcogenide nanocrystals, including in as-yet unexplored materials.

Effect of metallothionein core promoter region polymorphism on cadmium, zinc and copper levels in autopsy kidney tissues from a Turkish population

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

Kayaalti, Zeliha, E-mail: kayaalti@medicine.ankara.edu.t; Mergen, Goerkem; Soeylemezoglu, Tuelin

2010-06-01

Metallothioneins (MTs) are metal-binding, low molecular weight proteins and are involved in pathophysiological processes like metabolism of essential metals, metal ion homeostasis and detoxification of heavy metals. Metallothionein expression is induced by various heavy metals especially cadmium, mercury and zinc; MTs suppress toxicity of heavy metals by binding themselves to these metals. The aim of this study was to investigate the association between the - 5 A/G metallothionein 2A (MT2A) single nucleotide polymorphism (SNP) and Cd, Zn and Cu levels in the renal cortex from autopsy cases. MT2A core promoter region - 5 A/G SNP was analyzed by PCR-RFLP methodmore » using 114 autopsy kidney tissues and the genotype frequencies of this polymorphism were found as 87.7% homozygote typical (AA), 11.4% heterozygote (AG) and 0.9% homozygote atypical (GG). In order to assess the Cd, Zn and Cu levels in the same autopsy kidney tissues, a dual atomic absorption spectrophotometer system was used and the average levels of Cd, Zn and Cu were measured as 95.54 {+-} 65.58 {mu}g/g, 181.20 {+-} 87.72 {mu}g/g and 17.14 {+-} 16.28 {mu}g/g, respectively. As a result, no statistical association was found between the - 5 A/G SNP in the MT2A gene and the Zn and Cu levels in the renal cortex (p > 0.05), but considerably high accumulation of Cd was monitored for individuals having AG (151.24 {+-} 60.21 {mu}g/g) and GG genotypes (153.09 {mu}g/g) compared with individuals having AA genotype (87.72 {+-} 62.98 {mu}g/g) (p < 0.05). These results show that the core promoter region polymorphism of metallothionein 2A increases the accumulation of Cd in human renal cortex.« less

CXCL4 Exposure Potentiates TLR-Driven Polarization of Human Monocyte-Derived Dendritic Cells and Increases Stimulation of T Cells.

PubMed

Silva-Cardoso, Sandra C; Affandi, Alsya J; Spel, Lotte; Cossu, Marta; van Roon, Joel A G; Boes, Marianne; Radstake, Timothy R D J

2017-07-01

Chemokines have been shown to play immune-modulatory functions unrelated to steering cell migration. CXCL4 is a chemokine abundantly produced by activated platelets and immune cells. Increased levels of circulating CXCL4 are associated with immune-mediated conditions, including systemic sclerosis. Considering the central role of dendritic cells (DCs) in immune activation, in this article we addressed the effect of CXCL4 on the phenotype and function of monocyte-derived DCs (moDCs). To this end, we compared innate and adaptive immune responses of moDCs with those that were differentiated in the presence of CXCL4. Already prior to TLR- or Ag-specific stimulation, CXCL4-moDCs displayed a more matured phenotype. We found that CXCL4 exposure can sensitize moDCs for TLR-ligand responsiveness, as illustrated by a dramatic upregulation of CD83, CD86, and MHC class I in response to TLR3 and TLR7/8-agonists. Also, we observed a markedly increased secretion of IL-12 and TNF-α by CXCL4-moDCs exclusively upon stimulation with polyinosinic-polycytidylic acid, R848, and CL075 ligands. Next, we analyzed the effect of CXCL4 in modulating DC-mediated T cell activation. CXCL4-moDCs strongly potentiated proliferation of autologous CD4 + T cells and CD8 + T cells and production of IFN-γ and IL-4, in an Ag-independent manner. Although the internalization of Ag was comparable to that of moDCs, Ag processing by CXCL4-moDCs was impaired. Yet, these cells were more potent at stimulating Ag-specific CD8 + T cell responses. Together our data support that increased levels of circulating CXCL4 may contribute to immune dysregulation through the modulation of DC differentiation. Copyright © 2017 by The American Association of Immunologists, Inc.

In situ synthesis of CdS/CdWO4/WO3 heterojunction films with enhanced photoelectrochemical properties

NASA Astrophysics Data System (ADS)

Zhan, Faqi; Li, Jie; Li, Wenzhang; Yang, Yahui; Liu, Wenhua; Li, Yaomin

2016-09-01

CdS/CdWO4/WO3 heterojunction films on fluorine-doped tin oxide (FTO) substrates are for the first time prepared as an efficient photoanode for photoelectrochemical (PEC) hydrogen generation by an in situ conversion process. The samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet visible spectrometry (UV-vis) and X-ray photoelectron spectroscopy (XPS). The CdS hollow spheres (∼80 nm) sensitized WO3 plate film with a CdWO4 buffer-layer exhibits increased visible light absorption and a significantly improved photoelectrochemical performance. The photocurrent density at 0 V (vs. Ag/AgCl) of the CdS/CdWO4/WO3 anode is ∼3 times higher than that of the CdWO4/WO3 anode, and ∼9 times higher than that of pure WO3 under illumination. The highest incident-photon-to-current-efficiency (IPCE) value increased from 16% to 63% when the ternary heterojunction was formed. This study demonstrates that the synthesis of ternary composite photocatalysts by the in situ conversion process may be a promising approach to achieve high photoelectric conversion efficiency.

Hepatitis B surface antigen (HBsAg) and core antigen (HBcAg) combine CpG oligodeoxynucletides as a novel therapeutic vaccine for chronic hepatitis B infection.

PubMed

Li, Jianqiang; Ge, Jun; Ren, Sulin; Zhou, Tong; Sun, Ying; Sun, Honglin; Gu, Yue; Huang, Hongying; Xu, Zhenxing; Chen, Xiaoxiao; Xu, Xiaowei; Zhuang, Xiaoqian; Song, Cuiling; Jia, Fangmiao; Xu, Aiguo; Yin, Xiaojin; Du, Sean X

2015-08-20

Hepatitis B virus infection is a non-cytopathic hepatotropic virus which can lead to chronic liver disease and hepatocellular carcinoma. Traditional therapies fail to provide sustained control of viral replication and liver damage in most patients. As an alternative strategy, immunotherapeutic approaches have shown promising efficacy in the treatment of chronic hepatitis B patients. Here, we investigated the efficacy of a novel therapeutic vaccine formulation consisting of two HBV antigens, HBsAg and HBcAg, and CpG adjuvant. This vaccine formulation elicits forceful humoral responses directed against HBsAg/HBcAg, and promotes a Th1/Th2 balance response against HBsAg and a Th1-biased response against HBcAg in both C57BL/6 and HBV transgenic mice. Vigorous cellular immune response was also detected in HBV transgenic mice, for a significantly higher number of HBs/HBc-specific IFN-γ secreting CD4+ and CD8+ T cells was generated. Moreover, vaccinated mice elicited significantly intense in vivo CTL attack, reduced serum HBsAg level without causing liver damage in HBV transgenic mice. In summary, this study demonstrates a novel therapeutic vaccine with the potential to elicit vigorous humoral and cellular response, overcoming tolerance in HBV transgenic mice. Copyright © 2015 Elsevier Ltd. All rights reserved.

Developing multifunctional nanoparticles in a 1-D coordination polymer of Cd(II)

NASA Astrophysics Data System (ADS)

Agarwal, Rashmi A.; Gupta, Neeraj K.

2017-11-01

A simple synthesis for the integration of different nanoparticles (NPs) including Ag, Au, Pd, Cr and mixed (Cu/Fe), has been demonstrated within the nanopores of a non-activated one dimensional porous coordination polymer (PCP) of Cd(II) due to its high flexible structure. There are two different mechanisms (acid formation (HCl/HNO3) and redox activity of the framework) elucidated by electron paramagnetic resonance (EPR). Presence of -NO2 groups of the ligand act as anchoring sites for metal ions of metal precursors leading to NPs growth within the PCP explained by FTIR. High resolution transmission electron microscopy (HRTEM) images provided insight of the chemical and physical characteristics of the NPs within the framework. Ag/AgO NPs exhibit excellent antibacterial properties at extremely low concentrations. The polymer shows potential for sequestration and reduction of hexavalent Cr (highly toxic) to elemental, trivalent and tetravalent Cr (non toxic). This framework is also an excellent template for fabrication and dry storage of nanoparticles synthesized by mixed metal precursors. Ferromagnetic properties have been shown by Ag and Au NPs integrated frameworks while Cu/Fe@Cd-PCP behaves as a paramagnet material at room temperature.

A flexible plasma-treated silver-nanowire electrode for organic light-emitting devices.

PubMed

Li, Jun; Tao, Ye; Chen, Shufen; Li, Huiying; Chen, Ping; Wei, Meng-Zhu; Wang, Hu; Li, Kun; Mazzeo, Marco; Duan, Yu

2017-11-28

Silver nanowires (AgNWs) are a promising candidate to replace indium tin oxide (ITO) as transparent electrode material. However, the loose contact at the junction of the AgNWs and residual surfactant polyvinylpyrrolidone (PVP) increase the sheet resistance of the AgNWs. In this paper, an argon (Ar) plasma treatment method is applied to pristine AgNWs to remove the PVP layer and enhance the contact between AgNWs. By adjusting the processing time, we obtained AgNWs with a sheet resistance of 7.2Ω/□ and a transmittance of 78% at 550 nm. To reduce the surface roughness of the AgNWs, a peel-off process was used to transfer the AgNWs to a flexible NOA63 substrate. Then, an OLED was fabricated with the plasma-treated AgNWs electrode as anode. The highest brightness (27000 cd/m 2 ) and current efficiency (11.8 cd/A) was achieved with a 30 nm thick light emitting layer of tris-(8-hydroxyquinoline) aluminum doped with 1% 10-(2-benzothiazolyl)-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5 H,11H-(1)-benzopyropyrano(6,7-8-I,j)quinolizin-11-one. Compared to thermal annealing, the plasma-treated AgNW film has a lower sheet resistance, a shorter processing time, and a better hole-injection. Our results indicate that plasma treatment is an effective and efficient method to enhance the conductivity of AgNW films, and the plasma-treated AgNW electrode is suitable to manufacture flexible organic optoelectronic devices.

ALLOY COMPOSITION FOR NEUTRONIC REACTOR CONTROL RODS

DOEpatents

Lustman, B.; Losco, E.F.; Snyder, H.J.; Eggleston, R.R.

1963-01-22

This invention relates to alloy compositons suitable as cortrol rod material consisting of, by weight, from 85% to 85% Ag, from 2% to 20% In, from up to 10% of Cd, from up to 5% Sn, and from up to 1.5% Al, the amount of each element employed being determined by the equation X + 2Y + 3Z + 3W + 4V = 1.4 and less, where X, Y, Z, W, and V represent the atom fractions of the elements Ag, Cd, In, Al and Sn. (AEC)

Estimating the cost-per-result of a national reflexed Cryptococcal antigenaemia screening program: Forecasting the impact of potential HIV guideline changes and treatment goals.

PubMed

Cassim, Naseem; Coetzee, Lindi Marie; Schnippel, Kathryn; Glencross, Deborah Kim

2017-01-01

During 2016, the National Health Laboratory Service (NHLS) introduced laboratory-based reflexed Cryptococcal antigen (CrAg) screening to detect early Cryptococcal disease in immunosuppressed HIV+ patients with a confirmed CD4 count of 100 cells/μl or less. The aim of this study was to assess cost-per-result of a national screening program across different tiers of laboratory service, with variable daily CrAg test volumes. The impact of potential ART treatment guideline and treatment target changes on CrAg volumes, platform choice and laboratory workflow are considered. CD4 data (with counts < = 100 cells/μl) from the fiscal year 2015/16 were extracted from the NHLS Corporate Date Warehouse and used to project anticipated daily CrAg testing volumes with appropriately-matched CrAg testing platforms allocated at each of 52 NHLS CD4 laboratories. A cost-per-result was calculated for four scenarios, including the existing service status quo (Scenario-I), and three other settings (as Scenarios II-IV) which were based on information from recent antiretroviral (ART) guidelines, District Health Information System (DHIS) data and UNAIDS 90/90/90 HIV/AIDS treatment targets. Scenario-II forecast CD4 testing offered only to new ART initiates recorded at DHIS. Scenario-III projected all patients notified as HIV+, but not yet on ART (recorded at DHIS) and Scenario-IV forecast CrAg screening in 90% of estimated HIV+ patients across South Africa (also DHIS). Stata was used to assess daily CrAg volumes at the 5th, 10th, 25th, 50th, 75th, 90th and 95th percentiles across 52 CD4-laboratories. Daily volumes were used to determine technical effort/ operator staff costs (% full time equivalent) and cost-per-result for all scenarios. Daily volumes ranged between 3 and 64 samples for Scenario-I at the 5th and 95th percentile. Similarly, daily volumes ranges of 1-12, 2-45 and 5-100 CrAg-directed samples were noted for Scenario's II, III and IV respectively. A cut-off of 30 CrAg tests per day defined use of either LFA or EIA platform. LFA cost-per-result ranged from $8.24 to $5.44 and EIA cost-per-result between $5.58 and $4.88 across the range of test volumes. The technical effort across scenarios ranged from 3.2-27.6% depending on test volumes and platform used. The study reported the impact of programmatic testing requirements on varying CrAg test volumes that subsequently influenced choice of testing platform, laboratory workflow and cost-per-result. A novel percentiles approach is described that enables an overview of the cost-per-result across a national program. This approach facilitates cross-subsidisation of more expensive lower volume sites with cost-efficient, more centralized higher volume laboratories, mitigating against the risk of costing tests at a single site.

In Situ Localized Surface Plasmon Resonance (LSPR) Spectroscopy to Investigate Kinetics of Chemical Bath Deposition of CdS Thin Films

DOE PAGES

Kalyanaraman, Ramki; Taz, Humaira; Ruther, Rose E.; ...

2015-02-11

Techniques that can characterize the early stages of thin film deposition from liquid phase processes can aid greatly in our understanding of mechanistic aspects of chemical bath deposition (CBD). Here we have used localized surface plasmon resonance (LSPR) spectroscopy to monitor in-situ the kinetics of early-stage growth of cadmium sulfide (CdS) thin films on Ag nanoparticle on quartz substrates. Real-time shift during CdS deposition showed that the LSPR wavelength red shifted rapidly due to random deposition of CdS on the substrate, but saturated at longer times. LSPR modeling showed that these features could be interpreted as an initial deposition ofmore » CdS islands followed by preferential deposition onto itself. The CdS also showed significantly enhanced Raman signals up to 170 times due to surface enhanced raman scattering (SERS) from the CdS/Ag NP regions. The ex-situ SERS effect supported the LSPR shift suggesting that these techniques could be used to understand nucleation and growth phenomena from the liquid phase.« less

Radiation resistance of nonlinear crystals at a wavelength of 9.55 {mu}m

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

Andreev, Yu M; Voevodin, V G; Badikov, Valerii V

2001-12-31

The results of radiation resistance measurements for twelve nonlinear crystals are presented. The crystals include the well-known nonlinear CdGeAs{sub 2}, ZnGeP{sub 2}, AgGaSe{sub 2}, GaSe, AgGaS{sub 2}, and Ag{sub 3}AsS{sub 3} crystals operating in the middle IR range, new mixed AgGaGeS{sub 4} and Cd{sub 0.35}Hg{sub 0.65}Ga{sub 2}S{sub 4} crystals, two-phase (orange and yellow) HgGa{sub 2}S{sub 4} crystal, and the doped GaSe:In crystal. The mixed crystals and the two-phase HgGa{sub 2}S{sub 4} crystal are transparent in the range from 0.4 - 0.5 to 11.5 - 14.5 {mu}m. The measurements were performed using a pulsed single-mode highly stability TEA CO{sub 2} lasermore » with an output pulse duration of {approx}30 ns. The damage thresholds of new nonlinear AgGaGeS{sub 4} and Cd {sub 0.35}Hg{sub 0.65}Ga{sub 2}S{sub 4} crystals and of the HgGa{sub 2}S{sub 4} crystal (the orange and yellow phases) were found to be 1.5 - 2.2 times higher than for the crystals operating in the middle IR range. (interaction of laser radiation with matter. laser plasma)« less

Bioleaching mechanism of Zn, Pb, In, Ag, Cd and As from Pb/Zn smelting slag by autotrophic bacteria.

PubMed

Wang, Jia; Huang, Qifei; Li, Ting; Xin, Baoping; Chen, Shi; Guo, Xingming; Liu, Changhao; Li, Yuping

2015-08-15

A few studies have focused on release of valuable/toxic metals from Pb/Zn smelting slag by heterotrophic bioleaching using expensive yeast extract as an energy source. The high leaching cost greatly limits the practical potential of the method. In this work, autotrophic bioleaching using cheap sulfur or/and pyrite as energy matter was firstly applied to tackle the smelting slag and the bioleaching mechanisms were explained. The results indicated autotrophic bioleaching can solubilize valuable/toxic metals from slag, yielding maximum extraction efficiencies of 90% for Zn, 86% for Cd and 71% for In, although the extraction efficiencies of Pb, As and Ag were poor. The bioleaching performance of Zn, Cd and Pb was independent of leaching system, and leaching mechanism was acid dissolution. A maximum efficiency of 25% for As was achieved by acid dissolution in sulfursulfur oxidizing bacteria (S-SOB), but the formation of FeAsO4 reduced extraction efficiency in mixed energy source - mixed culture (MS-MC). Combined works of acid dissolution and Fe(3+) oxidation in MS-MC was responsible for the highest extraction efficiency of 71% for In. Ag was present in the slag as refractory AgPb4(AsO4)3 and AgFe2S3, so extraction did not occur. Copyright © 2015 Elsevier Ltd. All rights reserved.

Preparation of hair for measurement of elements by inductively coupled plasma-mass spectrometry (ICP-MS).

PubMed

Puchyr, R F; Bass, D A; Gajewski, R; Calvin, M; Marquardt, W; Urek, K; Druyan, M E; Quig, D

1998-06-01

The preparation of hair for the determination of elements is a critical component of the analysis procedure. Open-beaker, closed-vessel microwave, and flowthrough microwave digestion are methods that have been used for sample preparation and are discussed. A new digestion method for use with inductively coupled plasma-mass spectrometry (ICP-MS) has been developed. The method uses 0.2 g of hair and 3 mL of concentrated nitric acid in an atmospheric pressure-low-temperature microwave digestion (APLTMD) system. This preparation method is useful in handling a large numbers of samples per day and may be adapted to hair sample weights ranging from 0.08 to 0.3 g. After digestion, samples are analyzed by ICP-MS to determine the concentration of Li, Be, B, Na, Mg, Al, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, As, Se, Rb, Sr, Zr, Mo, Pd, Ag, Cd, Sn, Sb, I, Cs, Ba, Pt, Au, Hg, Tl, Pb, Bi, Th, and U. Benefits of the APLTMD include reduced contamination and sample handling, and increased precision, reliability, and sample throughput.

Direct detection of cysteine using functionalized BaTiO3 nanoparticles film based self-powered biosensor.

PubMed

Selvarajan, Sophia; Alluri, Nagamalleswara Rao; Chandrasekhar, Arunkumar; Kim, Sang-Jae

2017-05-15

Simple, novel, and direct detection of clinically important biomolecules have continuous demand among scientific community as well as in market. Here, we report the first direct detection and facile fabrication of a cysteine-responsive, film-based, self-powered device. NH 2 functionalized BaTiO 3 nanoparticles (BT-NH 2 NPs) suspended in a three-dimensional matrix of an agarose (Ag) film, were used for cysteine detection. BaTiO 3 nanoparticles (BT NPs) semiconducting as well as piezoelectric properties were harnessed in this study. The changes in surface charge properties of the film with respect to cysteine concentrations were determined using a current-voltage (I-V) technique. The current response increased with cysteine concentration (linear concentration range=10µM-1mM). Based on the properties of the composite (BT/Ag), we created a self-powered cysteine sensor in which the output voltage from a piezoelectric nanogenerator was used to drive the sensor. The potential drop across the sensor was measured as a function of cysteine concentrations. Real-time analysis of sensor performance was carried out on urine samples by non-invasive method. This novel sensor demonstrated good selectivity, linear concentration range and detection limit of 10µM; acceptable for routine analysis. Copyright © 2016 Elsevier B.V. All rights reserved.

A hydrometallurgical process for recovering total metal values from waste monolithic ceramic capacitors.

PubMed

Prabaharan, G; Barik, S P; Kumar, B

2016-06-01

A hydrometallurgical process for recovering the total metal values from waste monolithic ceramic capacitors was investigated. The process parameters such as time, temperature, acid concentration, hydrogen peroxide concentration and other reagents (amount of zinc dust and sodium formate) were optimized. Base metals such as Ba, Ti, Sn, Cu and Ni are leached out in two stages using HCl in stage 1 and HCl with H2O2 in stage 2. More than 99% of leaching efficiency for base metals (Cu, Ni, Ba, Ti and Sn) was achieved. Precious metals such as Au and Pd are leached out using aquaregia and nitric acid was used for the leaching of Ag. Base metals (Ba, Ti, Sn, Cu and Ni) are recovered by selective precipitation using H2SO4 and NaOH solution. In case of precious metals, Au and Pd from the leach solution were precipitated out using sodium metabisulphite and sodium formate, respectively. Sodium chloride was used for the precipitation of Ag from leach solution. Overall recovery for base metals and precious metals are 95% and 92%, respectively. Based on the results of the present study, a process flow diagram was proposed for commercial application. Copyright © 2016 Elsevier Ltd. All rights reserved.

Analysis of beta-decay rates for Ag 108, Ba 133, Eu 152, Eu 154, Kr 85, Ra 226, and Sr 90, measured at the Physikalisch-Technische Bundesanstalt from 1990 to 1996

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

Sturrock, P. A.; Fischbach, E.; Jenkins, J.

2014-10-10

We present the results of an analysis of measurements of the beta-decay rates of Ag 108, Ba 133, Eu 152, Eu 154, Kr 85, Ra 226, and Sr 90 acquired at the Physikalisch-Technische Bundesanstalt from 1990 through 1995. Although the decay rates vary over a range of 165 to 1 and the measured detector current varies over a range of 19 to 1, the detrended and normalized count rate measurements exhibit a sinusoidal annual variation with amplitude in the small range 0.068%-0.088% (mean 0.081%, standard deviation 0.0072%, a rejection of the zero-amplitude hypothesis) and phase-of-maximum in the small range 0.062-0.083more » (January 23 to January 30). In comparing these results with those of other related experiments that yield different results, it may be significant that this experiment, at a standards laboratory, seems to be unique in using a 4π detector. These results are compatible with a solar influence, and do not appear to be compatible with an experimental or environmental influence. It is possible that Ba 133 measurements are also subject to a non-solar (possibly cosmic) influence.« less

The occurrence and distribution of trace metals in the Mississippi River and its tributaries

USGS Publications Warehouse

Taylor, Howard E.; Garbarino, J.R.; Brinton, T.I.

1990-01-01

Quantitative and semiquantitative analyses of dissolved trace metals are reported for designated sampling sites on the Mississippi River and its main tributaries utilizing depth-integrated and width-integrated sampling technology to collect statistically representative samples. Data are reported for three sampling periods, including: July-August 1987, November-December 1987, and May-June 1988. Concentrations of Al, As, Ba, Be, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Pb, Sr, Tl, U, V, and Zn are reported quantitatively, with the remainder of the stable metals in the periodic table reported semiquantitatively. Correlations between As and V, Ba and U, Cu and Zn, Li and Ba, and Li and U are significant at the 99% confidence level for each of the sampling trips. Comparison of the results of this study for selected metals with other published data show generally good agreement for Cr, Cu, Fe, and Zn, moderate agreement for Mo, and poor agreement for Cd and V.

Human Immunodeficiency Virus Type 1 (HIV-1) Integration: a Potential Target for Microbicides To Prevent Cell-Free or Cell-Associated HIV-1 Infection ▿

PubMed Central

Terrazas-Aranda, Katty; Van Herrewege, Yven; Hazuda, Daria; Lewi, Paul; Costi, Roberta; Di Santo, Roberto; Cara, Andrea; Vanham, Guido

2008-01-01

Conceptually, blocking human immunodeficiency virus type 1 (HIV-1) integration is the last possibility for preventing irreversible cellular infection. Using cocultures of monocyte-derived dendritic cells and CD4+ T cells, which represent primary targets in sexual transmission, we demonstrated that blocking integration with integrase strand transfer inhibitors (InSTIs), particularly L-870812, could consistently block cell-free and cell-associated HIV-1 infection. In a pretreatment setting in which the compound was present before and during infection and was afterwards gradually diluted during the culture period, the naphthyridine carboxamide L-870812 blocked infection with the cell-free and cell-associated HIV-1 Ba-L strain at concentrations of, respectively, 1,000 and 10,000 nM. The potency of L-870812 was similar to that of the nucleotide reverse transcriptase inhibitor R-9-(2-phosphonylmethoxypropyl) adenine (PMPA) but one or two orders of magnitude lower than those of the nonnucleoside reverse transcriptase inhibitors UC781 and TMC120. In contrast, the diketo acid RDS derivative InSTIs showed clear-cut but weaker antiviral activity than L-870812. Moreover, L-870812 completely blocked subtype C and CRFO2_AG primary isolates, which are prevalent in the African heterosexual epidemic. Furthermore, the addition of micromolar concentrations of L-870812 even 24 h after infection could still block both cell-free and cell-associated Ba-L, opening the prospect of postexposure prophylaxis. Finally, an evaluation of the combined activity of L-870812 with either T20, zidovudine, PMPA, UC781, or TMC120 against replication-deficient HIV-1 Ba-L (env) pseudovirus suggested synergistic activity for all combinations. Importantly, compounds selected for the study by using the coculture model were devoid of acute or delayed cytotoxic effects at HIV-blocking concentrations. Therefore, these findings provide evidence supporting consideration of HIV-1 integration as a target for microbicide development. PMID:18474579

Pulse Pressure, Instead of Brachium-Ankle Pulse Wave Velocity, is Associated with Reduced Kidney Function in a Chinese Han Population.

PubMed

Jia, Linpei; Zhang, Weiguang; Ma, Jie; Chen, Xizhao; Chen, Lei; Li, Zuoxiang; Cai, Guangyan; Huang, Jing; Zhang, Jinping; Bai, Xiaojuan; Feng, Zhe; Sun, Xuefeng; Chen, Xiangmei

2017-01-01

In this study, we aim to investigate the association between renal function and arterial stiffness in a Chinese Han population, and further to discuss the effects of smoking on renal function. We collected the data of the brachium-ankle pulse wave velocity (baPWV), blood pressure, blood chemistry and smoking status. Then, the multiple linear regression was done to explore the relationship between estimated glomerular filtration (eGFR) and baPWV. Further, the parameters were compared among the four groups divided according to the quartiles of baPWV. Finally, the baPWV, eGFR and albuminuria values were compared between smokers and non-smokers. baPWV is associated with eGFR in the correlation analysis and univariate linear regression model. After adjustment, the pulse pressure (PP) instead of baPWV showed a significant association with eGFR. Nevertheless, the eGFR values differed among the four baPWV groups; the baPWV values were significantly higher in the subjects at the CKD (eGFR<60 mL/min/1.73 m2) and the early CKD stage (eGFR60-80 mL/min/1.73 m2). The baPWV values and the ratio of proteinuria were significantly increased in smokers. PP but not baPWV is a predictor of declined renal function. Smokers have worse arterial stiffness and worse renal function. © 2017 The Author(s)Published by S. Karger AG, Basel.

Cadmium sulfide anchored in three-dimensional graphite cage for high performance supercapacitors

NASA Astrophysics Data System (ADS)

Chen, Liang; Zuo, Yinze; Zhang, Yu; Gao, Yanmin

2018-05-01

Cadmium sulfide (CdS) nanoparticles were anchored in a three-dimensional (3D) graphite cage for high performance supercapacitors. Significantly, the graphite cage intensified the construction of electroactive materials and facilitated the transfer of ions. As a result, the 3D-CdS/graphite cage revealed a great thermal stability and high specific capacitance (511 F/g at 5 A/g). Additionally, the 3D-CdS/graphite//reduced graphene oxide (rGO) asymmetric supercapacitor revealed a high energy density (30.4 Wh/kg at a power density of 800 W/kg) and long-term cycling stability (90.1% retention after 5000 cycles at 10 A/g) for practical applications.

PERIODS OF VERTEBRAL COLUMN SENSITIVITY TO BORIC ACID TREATMENT IN CD-1 MICE IN UTERO

EPA Science Inventory

Periods of vertebral column sensitivity to boric acid treatment in CD-1 mice in utero.

Cherrington JW, Chernoff N.

Department of Toxicology, North Carolina State University, Raleigh, NC 27695, USA. jana_cherrington@hotmail.com

Boric acid (BA) has many uses as...

Leaching assessments of toxic metals in waste plasma display panel glass.

PubMed

Chen, Mengjun; Jiang, Pengfei; Chen, Haiyan; Ogunseitan, Oladele A; Li, Yungui

2015-06-01

The plasma display panel (PDP) is rapidly becoming obsolete, contributing in large amounts to the electronic waste stream. In order to assess the potential for environmental pollution due to hazardous metals leached from PDP glass, standardized leaching procedures, chemical speciation assessments, and bioavailability tests were conducted. According to the Toxicity Characteristic Leaching Procedure (TCLP), arsenic in back glass was present at 4.46 ± 0.22 mg/L, close to its regulation limit of 5 mg/L. Zn is not available in the TCLP, but its TCLP leaching concentration in back glass is 102.96 ± 5.34 mg/L. This is because more than 90% of Zn is in the soluble and exchangeable and carbonate fraction. We did not detect significant levels of Ag, Ba, or Cu in the TCLP leachate, and the main fraction of Ag and Ba is residual, more than 95%, while the fraction distribution of Cu changes SEP by SEP. Ethylenediamine tetraacetic acid (EDTA)- and diethylenetriamine pentaacetic acid (DTPA)-extractable Ag, As, Ba, Cu, Zn, and Ni indicate a lower biohazards potential. These results show that, according to the EPA regulations, PDP glass may not be classified as hazardous waste because none of the metals exceeded their thresholds in PDP leachate. However, the concentrations of As and Zn should be lowered in the manufacturing process and finished product to avoid potential pollution problems. The plasma display panel is rapidly becoming obsolete because of the liquid crystal display. In this study, the leachability of heavy metals contained in the waste plasma display panel glass was first examined by standardized leaching tests, typical chemical speciation assessments, and bioavailability tests, providing fundamental data for waste PDP glass recovery, recycling, and reuse.

Aborted germinal center reactions and B cell memory by follicular T cells specific for a B cell receptor V region peptide.

PubMed

Heiser, Ryan A; Snyder, Christopher M; St Clair, James; Wysocki, Lawrence J

2011-07-01

A fundamental problem in immunoregulation is how CD4(+) T cells react to immunogenic peptides derived from the V region of the BCR that are created by somatic mechanisms, presented in MHC II, and amplified to abundance by B cell clonal expansion during immunity. BCR neo Ags open a potentially dangerous avenue of T cell help in violation of the principle of linked Ag recognition. To analyze this issue, we developed a murine adoptive transfer model using paired donor B cells and CD4 T cells specific for a BCR-derived peptide. BCR peptide-specific T cells aborted ongoing germinal center reactions and impeded the secondary immune response. Instead, they induced the B cells to differentiate into short-lived extrafollicular plasmablasts that secreted modest quantities of Ig. These results uncover an immunoregulatory process that restricts the memory pathway to B cells that communicate with CD4 T cells via exogenous foreign Ag.

Active hexose correlated compound enhances tumor surveillance through regulating both innate and adaptive immune responses.

PubMed

Gao, Yunfei; Zhang, Dongqing; Sun, Buxiang; Fujii, Hajime; Kosuna, Ken-Ichi; Yin, Zhinan

2006-10-01

Active hexose correlated compound (AHCC) is a mixture of polysaccharides, amino acids, lipids and minerals derived from cocultured mycelia of several species of Basidiomycete mushrooms. AHCC has been implicated to modulate immune functions and plays a protective role against infection. However, the potential role of AHCC in tumor immune surveillance is unknown. In this study, C57BL/6 mice were orally administered AHCC or water, followed by tumor cell inoculation. We showed that compared to pure water-treated mice, AHCC treatment significantly delayed tumor development after inoculation of either melanoma cell line B16F0 or lymphoma cell line EL4. Treatment with AHCC enhanced both Ag-specific activation and proliferation of CD4(+) and CD8(+) T cells, increased the number of tumor Ag-specific CD8(+) T cells, and more importantly, increased the frequency of tumor Ag-specific IFN-gamma producing CD8(+) T cells. Interestingly, AHCC treatment also showed increased cell number of NK and gammadelta T cells, indicating the role of AHCC in activating these innate-like lymphocytes. In summary, our results demonstrate that AHCC can enhance tumor immune surveillance through regulating both innate and adaptive immune responses.

A chimeric α-amylase engineered from Bacillus acidicola and Geobacillus thermoleovorans with improved thermostability and catalytic efficiency.

PubMed

Parashar, Deepak; Satyanarayana, T

2016-04-01

The α-amylase (Ba-amy) of Bacillus acidicola was fused with DNA fragments encoding partial N- and C-terminal region of thermostable α-amylase gene of Geobacillus thermoleovorans (Gt-amy). The chimeric enzyme (Ba-Gt-amy) expressed in Escherichia coli displays marked increase in catalytic efficiency [K cat: 4 × 10(4) s(-1) and K cat/K m: 5 × 10(4) mL(-1) mg(-1) s(-1)] and higher thermostability than Ba-amy. The melting temperature (T m) of Ba-Gt-amy (73.8 °C) is also higher than Ba-amy (62 °C), and the CD spectrum analysis revealed the stability of the former, despite minor alteration in secondary structure. Langmuir-Hinshelwood kinetic analysis suggests that the adsorption of Ba-Gt-amy onto raw starch is more favourable than Ba-amy. Ba-Gt-amy is thus a suitable biocatalyst for raw starch saccharification at sub-gelatinization temperatures because of its acid stability, thermostability and Ca(2+) independence, and better than the other known bacterial acidic α-amylases.

Impaired NK Cell Responses to Pertussis and H1N1 Influenza Vaccine Antigens in Human Cytomegalovirus-Infected Individuals

PubMed Central

Nielsen, Carolyn M.; White, Matthew J.; Bottomley, Christian; Lusa, Chiara; Rodríguez-Galán, Ana; Turner, Scarlett E. G.; Goodier, Martin R.

2015-01-01

NK cells contribute to postvaccination immune responses after activation by IL-2 from Ag-specific memory T cells or by cross-linking of the low-affinity IgG receptor, CD16, by Ag–Ab immune complexes. Sensitivity of NK cells to these signals from the adaptive immune system is heterogeneous and influenced by their stage of differentiation. CD56dimCD57+ NK cells are less responsive to IL-2 and produce less IFN-γ in response to T cell–mediated activation than do CD56bright or CD56dimCD57− NK cells. Conversely, NK cell cytotoxicity, as measured by degranulation, is maintained across the CD56dim subsets. Human CMV (HCMV), a highly prevalent herpes virus causing lifelong, usually latent, infections, drives the expansion of the CD56dimCD57+NKG2C+ NK cell population, skewing the NK cell repertoire in favor of cytotoxic responses at the expense of cytokine-driven responses. We hypothesized, therefore, that HCMV seropositivity would be associated with altered NK cell responses to vaccine Ags. In a cross-sectional study of 152 U.K. adults, with HCMV seroprevalence rate of 36%, we find that HCMV seropositivity is associated with lower NK cell IFN-γ production and degranulation after in vitro restimulation with pertussis or H1N1 influenza vaccine Ags. Higher expression of CD57/NKG2C and lower expression of IL-18Rα on NK cells from HCMV seropositive subjects do not fully explain these impaired responses, which are likely the result of multiple receptor–ligand interactions. This study demonstrates for the first time, to our knowledge, that HCMV serostatus influences NK cell contributions to adaptive immunity and raises important questions regarding the impact of HCMV infection on vaccine efficacy. PMID:25855356

Chitosan film loaded with silver nanoparticles-sorbent for solid phase extraction of Al(III), Cd(II), Cu(II), Co(II), Fe(III), Ni(II), Pb(II) and Zn(II).

PubMed

Djerahov, Lubomir; Vasileva, Penka; Karadjova, Irina; Kurakalva, Rama Mohan; Aradhi, Keshav Krishna

2016-08-20

The present study describes the ecofriendly method for the preparation of chitosan film loaded with silver nanoparticles (CS-AgNPs) and application of this film as efficient sorbent for separation and enrichment of Al(III), Cd(II), Cu(II), Co(II), Fe(III), Ni(II), Pb(II) and Zn(II). The stable CS-AgNPs colloid was prepared by dispersing the AgNPs sol in chitosan solution at appropriate ratio and further used to obtain a cast film with very good stability under storage and good mechanical strength for easy handling in aqueous medium. The incorporation of AgNPs in the structure of CS film and interaction between the polymer matrix and nanoparticles were confirmed by UV-vis and FTIR spectroscopy. The homogeneously embedded AgNPs (average diameter 29nm, TEM analysis) were clearly observed throughout the film by SEM. The CS-AgNPs nanocomposite film shows high sorption activity toward trace metals under optimized chemical conditions. The results suggest that the CS-AgNPs nanocomposite film can be feasibly used as a novel sorbent material for solid-phase extraction of metal pollutants from surface waters. Copyright © 2016 Elsevier Ltd. All rights reserved.

Competitive cesium-133 NMR spectroscopic study of complexation of different metal ions with dibenzo-21-crown-7 in acetonitrile-dimethylsulfoxide and nitromethane-dimethylsulfoxide mixtures.

PubMed

Sahmsipur, Mojtaba; Dastjerdi, Leila Shafiee; Alizadeh, Nader; Bijanzadeh, Hamid Reza

2008-04-01

(133)Cs NMR spectroscopy was used to determine the stoichiometry and stability of the Cs(+) ion complex with dibenzo-21-crown-7 (DB21C7) in acetonitrile-dimethylsulfoxide (96.5:3.5, w/w) and nitromethane-dimethylsulfoxide (96.5:3.5, w/w) mixtures. A competitive (133)Cs NMR technique was also employed to probe the complexation of Na(+), K(+), Rb(+), Ag(+), Tl(+), NH(4)(+), Mg(2+), Ba(2+), Hg(2+), Pb(2+) and UO(2)(2+) ions with DB21C7 in the same solvent systems. All the resulting 1:1 complexes in nitromethane-dimethylsulfoxide were more stable than those in acetonitrile-dimethylsulfoxide solution. In both solvent systems, the stability of the resulting complexes was found to vary in the order Rb(+)>K(+) approximately Ba(2+)>Tl(+)>Cs(+)>NH(4)(+) approximately Pb(2+)>Ag(+)>UO(2)(2+)>Hg(2+)>Mg(2+)>Na(+).

Metal ion displacements in noncentrosymmetric chalcogenides La3Ga1.67S7, La3Ag0.6GaCh7 (Ch=S, Se), and La3MGaSe7 (M=Zn, Cd)

NASA Astrophysics Data System (ADS)

Iyer, Abishek K.; Yin, Wenlong; Rudyk, Brent W.; Lin, Xinsong; Nilges, Tom; Mar, Arthur

2016-11-01

The quaternary Ga-containing chalcogenides La3Ag0.6GaS7, La3Ag0.6GaSe7, La3ZnGaSe7, and La3CdGaSe7, as well as the related ternary chalcogenide La3Ga1.67S7, were prepared by reactions of the elements at 950 °C. They adopt noncentrosymmetric hexagonal structures (space group P63, Z=2) with cell parameters (a=10.2 Å, c=6.1 Å for the sulfides; a=10.6 Å, c=6.4 Å for the selenides) that are largely controlled by the geometrical requirements of one-dimensional stacks of Ga-centered tetrahedra separated by the La atoms. Among these compounds, which share the common formulation La3M1-xGaCh7 (M=Ga, Ag, Zn, Cd; Ch=S, Se), the M atoms occupy sites within a stacking of trigonal antiprisms formed by Ch atoms. The location of the M site varies between extremes with trigonal antiprismatic (CN6) and trigonal planar (CN3) geometry. Partial occupation of these sites and intermediate ones accounts for the considerable versatility of these structures and the occurrence of large metal displacement parameters. The site occupations can be understood in a simple way as being driven by the need to satisfy appropriate bond valence sums for both the M and Ch atoms. Band structure calculations rationalize the substoichiometry observed in the Ag-containing compounds (La3Ag0.6GaS7, La3Ag0.6GaSe7) as a response to overbonding. X-ray photoelectron spectroscopy supports the presence of monovalent Ag atoms in these compounds, which are not charge-balanced.

Evaluation methods and evaporation conditions for low-resistivity contacts on high Tc superconductors

NASA Astrophysics Data System (ADS)

Liu, Y. P.; Warner, K.; Chan, C.; Chen, K.; Markiewicz, R.

1989-12-01

Low-resistivity contacts to bulk high-Tc superconductors have been prepared by resistive evaporation with values of rho-s (ohm sq cm) as low as 10 to the -10th (77 K) for Ag/YBaCuO, 10 to the -9th (77 K) for Ag/TlPbBaCaCuO, and 10 to the 7th (60 K) for Ag/BiCaSrCuO. It was found that rho-s is improved by increasing the length of a preevaporation step. This effect has been further investigated by secondary ion-mass spectrometry analysis on several Ag/Si samples. Both three-terminal and four-terminal methods have been used to determine rho-s; the three-terminal method shows less dependency on the sample/contact geometry for measurements taken above Tc.

Renal Allograft Survival in Nonhuman Primates Infused with Donor Antigen-Pulsed Autologous Regulatory Dendritic Cells

PubMed Central

Ezzelarab, M.B.; Raich-Regue, D.; Lu, L.; Zahorchak, A.F.; Perez-Gutierrez, A.; Humar, A.; Wijkstrom, M.; Minervini, M.; Wiseman, R.W.; Cooper, D.K.C.; Morelli, A.E.; Thomson, A.W.

2017-01-01

Systemic administration of autologous regulatory dendritic cells (DCreg; unpulsed or pulsed with donor antigen [Ag]), prolongs allograft survival and promotes transplant tolerance in rodents. Here, we demonstrate that nonhuman primate (NHP) monocyte-derived DCreg pre-loaded with cell membrane vesicles from allogeneic PBMC, induce T cell hyporesponsiveness to donor alloAg in vitro. These donor alloAg-pulsed autologous DCreg (1.4–3.6 x 106/kg) were administered intravenously, one day before MHC-mismatched renal transplantation to rhesus monkeys treated with costimulation blockade (cytotoxic T lymphocyte Ag 4 [CTLA4] Ig) and tapered rapamycin. Prolongation of graft median survival time from 39.5 days (no DCreg infusion; n=6 historical controls) and 29 days with control unpulsed DCreg (n=2), to 56 days with donor Ag-pulsed DCreg (n=5), was associated with evidence of modulated host CD4+ and CD8+ T cell responses to donor Ag and attenuation of systemic IL-17 production. Circulating anti-donor antibody (Ab) was not detected until CTLA4Ig withdrawal. One monkey treated with donor Ag-pulsed DCreg rejected its graft in association with progressively elevated anti-donor Ab, 525 days post-transplant (160 days after withdrawal of immunosuppression). These findings indicate a modest but not statistically significant beneficial effect of donor Ag-pulsed autologous DCreg infusion on NHP graft survival when administered with a minimal immunosuppressive drug regimen. PMID:28009481

CD40 ligand blockade induces CD4+ T cell tolerance and linked suppression.

PubMed

Honey, K; Cobbold, S P; Waldmann, H

1999-11-01

The CD40-CD40 ligand (CD40L) interaction is a key event in the initiation of an adaptive immune response, and as such the therapeutic value of CD40L blockade has been studied in many experimental models of tissue transplantation and autoimmune disease. In rodents, transplantation of allogeneic tissues under the cover of anti-CD40L Abs has resulted in prolonged graft survival but not tolerance. In this report, we show that failure to induce tolerance probably results from the inability of anti-CD40L Abs to prevent graft rejection elicited by the CD8+ T cell subset. When the CD8+ T cell population is controlled independently, using anti-CD8 Abs, then tolerance is possible. Transplantation tolerance induced by anti-CD4 mAbs can often be associated with dominant regulation, manifested as infectious tolerance and linked suppression, both of which are mediated by CD4+ T cells. We show here that CD4+ T cells rendered tolerant using anti-CD40L therapy exhibit the same regulatory property of linked suppression, as demonstrated by their ability to accept grafts expressing third party Ags only if they are expressed in conjunction with the tolerated Ags. This observation of linked suppression reveals a hitherto undocumented consequence of CD40L blockade that suggests the tolerant state is maintained by a dominant regulatory mechanism. Our results suggest that, although anti-CD40L Abs are attractive clinical immunotherapeutic agents, additional therapies to control aggressive CD8+ T cell responses may be required.

Blocking Virus Replication during Acute Murine Cytomegalovirus Infection Paradoxically Prolongs Antigen Presentation and Increases the CD8+ T Cell Response by Preventing Type I IFN-Dependent Depletion of Dendritic Cells.

PubMed

Loo, Christopher P; Snyder, Christopher M; Hill, Ann B

2017-01-01

Increasing amounts of pathogen replication usually lead to a proportionate increase in size and effector differentiation of the CD8 + T cell response, which is attributed to increased Ag and inflammation. Using a murine CMV that is highly sensitive to the antiviral drug famciclovir to modulate virus replication, we found that increased virus replication drove increased effector CD8 + T cell differentiation, as expected. Paradoxically, however, increased virus replication dramatically decreased the size of the CD8 + T cell response to two immunodominant epitopes. The decreased response was due to type I IFN-dependent depletion of conventional dendritic cells and could be reproduced by specific depletion of dendritic cells from day 2 postinfection or by sterile induction of type I IFN. Increased virus replication and type I IFN specifically inhibited the response to two immunodominant epitopes that are known to be dependent on Ag cross-presented by DCs, but they did not inhibit the response to "inflationary" epitopes whose responses can be sustained by infected nonhematopoietic cells. Our results show that type I IFN can suppress CD8 + T cell responses to cross-presented Ag by depleting cross-presenting conventional dendritic cells. Copyright © 2016 by The American Association of Immunologists, Inc.

White HDPE bottles as source of serious contamination of water samples with Ba and Zn.

PubMed

Reimann, Clemens; Grimstvedt, Andreas; Frengstad, Bjørn; Finne, Tor Erik

2007-03-15

During a recent study of surface water quality factory new white high-density polyethylene (HDPE) bottles were used for collecting the water samples. According to the established field protocol of the Geological Survey of Norway the bottles were twice carefully rinsed with water in the field prior to sampling. Several blank samples using milli-Q (ELGA) water (>18.2 MOmega) were also prepared. On checking the analytical results the blanks returned values of Ag, Ba, Sr, V, Zn and Zr. For Ba and Zn the values (c. 300 microg/l and 95 microg/l) were about 10 times above the concentrations that can be expected in natural waters. A laboratory test of the bottles demonstrated that the bottles contaminate the samples with significant amounts of Ba and Zn and some Sr. Simple acid washing of the bottles prior to use did not solve the contamination problem for Ba and Zn. The results suggest that there may exist "clean" and "dirty" HDPE bottles depending on manufacturer/production process. When collecting water samples it is mandatory to check bottles regularly as a possible source of contamination.

IL-10 and IL-27 producing dendritic cells capable of enhancing IL-10 production of T cells are induced in oral tolerance.

PubMed

Shiokawa, Aya; Tanabe, Kosuke; Tsuji, Noriko M; Sato, Ryuichiro; Hachimura, Satoshi

2009-06-30

Oral tolerance is a key feature of intestinal immunity, generating systemic tolerance to ingested antigens (Ag). Dendritic cells (DC) have been revealed as important immune regulators, however, the precise role of DC in oral tolerance induction remains unclear. We investigated the characteristics of DC in spleen, mesenteric lymph node (MLN), and Peyer's patch (PP) after oral Ag administration in a TCR-transgenic mouse model. DC from PP and MLN of tolerized mice induced IL-10 production but not Foxp3 expression in cocultured T cells. IL-10 production was markedly increased after 5-7-day Ag administration especially in PP DC. On the other hand, IL-27 production was increased after 2-5-day Ag administration. CD11b(+) DC, which increased after ingestion of Ag, prominently expressed IL-10 and IL-27 compared with CD11b(-) DC. These results suggest that IL-10 and IL-27 producing DC are increased by interaction with antigen specific T cells in PP, and these DC act as an inducer of IL-10 producing T cells in oral tolerance.

EndoU is a novel regulator of AICD during peripheral B cell selection.

PubMed

Poe, Jonathan C; Kountikov, Evgueni I; Lykken, Jacquelyn M; Natarajan, Abirami; Marchuk, Douglas A; Tedder, Thomas F

2014-01-13

Balanced transmembrane signals maintain a competent peripheral B cell pool limited in self-reactive B cells that may produce pathogenic autoantibodies. To identify molecules regulating peripheral B cell survival and tolerance to self-antigens (Ags), a gene modifier screen was performed with B cells from CD22-deficient C57BL/6 (CD22(-/-[B6])) mice that undergo activation-induced cell death (AICD) and fail to up-regulate c-Myc expression after B cell Ag receptor ligation. Likewise, lysozyme auto-Ag-specific B cells in Ig(Tg) hen egg lysozyme (HEL) transgenic mice inhabit the spleen but undergo AICD after auto-Ag encounter. This gene modifier screen identified EndoU, a single-stranded RNA-binding protein of ancient origin, as a major regulator of B cell survival in both models. EndoU gene disruption prevents AICD and normalizes c-Myc expression. These findings reveal that EndoU is a critical regulator of an unexpected and novel RNA-dependent pathway controlling peripheral B cell survival and Ag responsiveness that may contribute to peripheral B cell tolerance.

Metal ion displacements in noncentrosymmetric chalcogenides La{sub 3}Ga{sub 1.67}S{sub 7}, La{sub 3}Ag{sub 0.6}GaCh{sub 7} (Ch=S, Se), and La{sub 3}MGaSe{sub 7} (M=Zn, Cd)

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

Iyer, Abishek K.; Yin, Wenlong; Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900

The quaternary Ga-containing chalcogenides La{sub 3}Ag{sub 0.6}GaS{sub 7}, La{sub 3}Ag{sub 0.6}GaSe{sub 7}, La{sub 3}ZnGaSe{sub 7}, and La{sub 3}CdGaSe{sub 7}, as well as the related ternary chalcogenide La{sub 3}Ga{sub 1.67}S{sub 7}, were prepared by reactions of the elements at 950 °C. They adopt noncentrosymmetric hexagonal structures (space group P6{sub 3}, Z=2) with cell parameters (a=10.2 Å, c=6.1 Å for the sulfides; a=10.6 Å, c=6.4 Å for the selenides) that are largely controlled by the geometrical requirements of one-dimensional stacks of Ga-centered tetrahedra separated by the La atoms. Among these compounds, which share the common formulation La{sub 3}M{sub 1–x}GaCh{sub 7} (M=Ga, Ag,more » Zn, Cd; Ch=S, Se), the M atoms occupy sites within a stacking of trigonal antiprisms formed by Ch atoms. The location of the M site varies between extremes with trigonal antiprismatic (CN6) and trigonal planar (CN3) geometry. Partial occupation of these sites and intermediate ones accounts for the considerable versatility of these structures and the occurrence of large metal displacement parameters. The site occupations can be understood in a simple way as being driven by the need to satisfy appropriate bond valence sums for both the M and Ch atoms. Band structure calculations rationalize the substoichiometry observed in the Ag-containing compounds (La{sub 3}Ag{sub 0.6}GaS{sub 7}, La{sub 3}Ag{sub 0.6}GaSe{sub 7}) as a response to overbonding. X-ray photoelectron spectroscopy supports the presence of monovalent Ag atoms in these compounds, which are not charge-balanced. - Graphical abstract: Partial occupation of metal atoms in multiple sites accounts for versatility in Ga-containing chalcogenides La{sub 3}M{sub 1–x}GaCh{sub 7} with noncentrosymmetric hexagonal structures. - Highlights: • La{sub 3}M{sub 1–x}GaCh{sub 7} (M =Ga, Ag, Zn, Cd; Ch =S, Se) adopt related hexagonal structures. • Large displacements of M atoms originate from partial occupation of multiple sites. • Bond valence sum arguments give a simple explanation for site preference. • XPS studies confirm presence of monovalent Ag in La{sub 3}Ag{sub 0.6}GaCh{sub 7}. • Substoichiometry in La{sub 3}Ag{sub 0.6}GaCh{sub 7} avoids occupation of Ag–Ch antibonding levels.« less

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

Starska, Katarzyna, E-mail: katarzyna.starska@umed.lodz.pl; Bryś, Magdalena; Forma, Ewa

Metallothioneins (MTs) are intracellular thiol-rich heavy metal-binding proteins which join trace metal ions protecting cells against heavy metal toxicity and regulate metal distribution and donation to various enzymes and transcription factors. The goal of this study was to identify the − 5 A/G (rs28366003) single-nucleotide polymorphism (SNP) in the core promoter region of the MT2A gene, and to investigate its effect on allele-specific gene expression and Cd, Zn, Cu and Ni content in sinonasal inverted papilloma tissue (IP), with non-cancerous sinonasal mucosa (NCM) as a control. The MT2A promoter region − 5 A/G SNP was identified by restriction fragment lengthmore » polymorphism using 117 IP and 132 NCM. MT2A gene analysis was performed by quantitative real-time PCR. Metal levels were analyzed by flame atomic absorption spectrometry. The frequency of A allele carriage was 99.2% and 100% in IP and NCM, respectively. The G allele carriage was detected in 23.9% of IP and in 12.1% of the NCM samples. As a result, a significant association of − 5 A/G SNP in MT2A gene with mRNA expression in both groups was determined. A significant association was identified between the − 5 A/G SNP in the MT2A gene with mRNA expression in both groups. A highly significant association was detected between the rs28366003 genotype and Cd and Zn content in IP. Furthermore, significant differences were identified between A/A and A/G genotype with regard to the type of metal contaminant. The Spearman rank correlation results showed the MT2A gene expression and both Cd and Cu levels were negatively correlated. The results obtained in this study suggest that the − 5 A/G SNP in the MT2A gene may have an effect on allele-specific gene expression and toxic metal accumulation in sinonasal inverted papilloma. - Highlights: • MT2A gene expression and metal content in sinonasal inverted papilloma tissues • Association between SNP (rs28366003) and expression of MT2A • Significant associations between the SNP and Cd and Zn levels • Negative correlation between MT2A gene expression and Cd and Cu levels.« less

The − 5 A/G single-nucleotide polymorphism in the core promoter region of MT2A and its effect on allele-specific gene expression and Cd, Zn and Cu levels in laryngeal cancer

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

Starska, Katarzyna, E-mail: katarzyna.starska@umed.lodz.pl; Krześlak, Anna; Forma, Ewa

2014-10-15

Metallothioneins (MTs) are low molecular weight, cysteine-rich heavy metal-binding proteins which participate in the mechanisms of Zn homeostasis, and protect against toxic metals. MTs contain metal-thiolate cluster groups and suppress metal toxicity by binding to them. The aim of this study was to determine the − 5 A/G (rs28366003) single-nucleotide polymorphism (SNP) in the core promoter region of the MT2A gene and to investigate its effect on allele-specific gene expression and Cd, Zn and Cu content in squamous cell laryngeal cancer (SCC) and non-cancerous laryngeal mucosa (NCM) as a control. The MT2A promoter region − 5 A/G SNP was determinedmore » by restriction fragment length polymorphism using 323 SCC and 116 NCM. MT2A gene analysis was performed by quantitative real-time PCR. The frequency of A allele carriage was 94.2% and 91.8% in SCC and NCM, respectively, while G allele carriage was detected in 5.8% and 8.2% of SCC and NCM samples, respectively. As a result, a significant association was identified between the − 5 A/G SNP in the MT2A gene with mRNA expression in both groups. Metal levels were analyzed by flame atomic absorption spectrometry. The significant differences were identified between A/A and both the A/G and G/G genotypes, with regard to the concentration of the contaminating metal. The Spearman rank correlation results showed that the MT2A expression and Cd, Zn, Cu levels were negatively correlated. Results obtained in this study suggest that − 5 A/G SNP in MT2A gene may have an effect on allele-specific gene expression and accumulation of metal levels in laryngeal cancer. - Highlights: • MT2A gene expression and metal content in laryngeal cancer tissues • Association between SNP (rs28366003) and expression of MT2A • Significant associations between the SNP and Cd, Zn and Cu levels • Negative correlation between MT2A gene expression and Cd, Zn and Cu levels.« less

[Studies on six heavy metal elements dissolution characteristics of Andrographis herb by ICP-OES].

PubMed

Tang, Rui; Li, Tian-Peng; Gu, Xue-Shi; Li, Yong-Jian; Yang, Yi

2010-02-01

A simple and accurate method for the simultaneous determination of As, Ba, Cd, Cr, Cu and Pb in andrographis herb by inductively coupled plasma optical emission spectrometry (ICP-OES) was developed. The samples were digested by HNO3-HClO4. The digestion-determination method was evaluated with the relative standard deviations for all these elements between 2.1% and 4.6%, and the recoveries were between 92.0% and 103.2%. The measuring method was proved to be simple, reliable and highly sensitive. The dissolution characteristics of the 6 heavy metal elements in different solvents and with different extraction methods such as refluxing, soaking, and ultrasonic assisted extraction were studied. The experimental results showed that Ba was in the highest concentration followed by Cu and Cr, and the concentration of As, Pb and Cd was relatively lower in the herb. With the increase in ethanol concentration, the dissolution amount of Ba decreased but that of Cu and Cr increased, and the highest concentration of Cd was dissolved in acidic solution. Overall, Cd and Pb were difficult to dissolve out with 85% ethanol refluxing, but As dissolved comparatively more under the same condition. Comparing the extraction methods, the higher concentration of these 6 metals was obtained by refluxing water or alkaline water than that by 85% ethanol maceration. These differences might be related to the existent forms of these six elements in the herb. The determination and study on dissolution characteristics of these elements by using ICP-OES was important for rational using medicinal resources and ensuring the safety of drugs.

Periods of vertebral column sensitivity to boric acid treatment in CD-1 mice in utero.

PubMed

Cherrington, Jana W; Chernoff, Neil

2002-01-01

Boric acid (BA) has many uses as an industrial compound and is widely distributed in the environment. BA has been shown to produce rib agenesis, a rare effect in laboratory animals. This study was conducted to determine if there is a period of sensitivity to this unusual effect. BA (500 or 750 mg/kg) was administered p.o. to pregnant CD-1 mice once daily on gestational days (GDs) 6-10. A reduction of 13th rib length occurred at both dose levels. BA 400mg/kg was also administered twice daily on GD 6, 7, 8, 9, or 10 or on GDs 6-8. A significant decrease in average fetal weight was observed in all treatment groups. Significant increases in the incidence of cervical ribs/ossifications resulted from treatments on GD 7 and GDs 6-8. Rib agenesis occurred with treatment on GD 8 and GDs 6-8. Reduced rib length, a decreased incidence of supernumerary ribs (SNR), and an increased incidence of fused and/or branched ribs occurred when dams were treated GDs 6-8. Doses of 750 mg/kg given twice on day 8 produced significant increases in several thoracic skeletal anomalies. Further studies of pathogenesis are necessary to determine the earliest perturbations and the processes that are affected. The sensitivity of embryos to treatment on GD 8 to rib agenesis suggests that BA is affecting early processes such as gastrulation and presomitic mesoderm formation and patterning in this area.

Modulatory effects of two levels of dietary Alliums on immune response and certain immunological variables, following immunization, in White Leghorn chickens.

PubMed

Hanieh, Hamza; Narabara, Kiyoaki; Piao, Mingzi; Gerile, Chaogetu; Abe, Asaki; Kondo, Yasuhiro

2010-12-01

This study aimed at investigating the effects of dietary Allium sativum (garlic, G) and Allium cepa (onion, O) on immune functions in White Leghorn chicken. One-week-old chicks, were fed diets without (control) or with Alliums (GL and OL, 10 g or GH and OH, 30 g/kg diet). Chickens were immunized with Newcastle disease virus (NDV), sheep red blood cells (SRBC) and Brucella abortus (BA). Antibodies, lymphocyte proliferation, and ratios of CD4(+) , CD8(+) and CD4⁻ CD8⁻ lymphocytes were investigated. Histology and weights of the spleen, thymus and bursa (BF), and white blood cell (WBC) counts were studied as well. Alliums at 10 g/kg diet enhanced anti-NDV, anti-SRBC and anti-BA antibody productions, whereas 30 g/kg diet had less stimulatory effects. Histology of the lymphoid organs and proliferation of peripheral blood lymphocytes (PBL) were not influenced. However, splenocyte and thymocyte proliferations were augmented with garlic. Flow cytometry analysis showed reduction in CD4(+) and increase in CD4⁻ CD8⁻ lymphocyte ratios in GH and OH groups. Garlic-supplemented chickens had heavier spleen and thymus, and higher WBC counts, whereas BF weight increased with both Alliums at 30 g/kg diet. These results suggest that dietary Alliums have a potential to enhance the immune functions in White Leghorn chickens. © 2010 The Authors. Journal compilation © 2010 Japanese Society of Animal Science.

ICP-AES determination of minor- and major elements in apples after microwave assisted digestion.

PubMed

Juranović Cindrić, Iva; Krizman, Ivona; Zeiner, Michaela; Kampić, Štefica; Medunić, Gordana; Stingeder, Gerhard

2012-12-15

The aim of this paper was to determine the content of minor and major elements in apples by inductively coupled plasma atomic emission spectrometry (ICP-AES). Prior to ICP-AES measurement, dried apples were digested in a microwave assisted digestion system. The differences in the measured element concentrations after application of open and closed microwave system as sample preparation procedures are discussed. In whole apples, flesh and peel Ag, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Sr and Zn were analysed after optimisation and validating the analytical method using ICP-AES. The accuracy of the method determined by spiking experiments was very good (recoveries 88-115%) and the limits of detection of elements of interest were from 0.01 up to 14.7 μg g(-1). The reference ranges determined in all apple samples are 39-47 mg g(-1) for K, 9-14 mg g(-1) for Na, 3-7 mg g(-1) for Mg, 3-7 μg g(-1) for Zn, 0.7-2.8 μg g(-1) for Sr. The range of Mn in peel 4-6 μg g(-1) is higher compared to whole apple from 0.7 to 1.7 μg g(-1). Cd is found only in peel, in the concentration range of 0.4-1.1 μg g(-1). Copyright © 2012 Elsevier Ltd. All rights reserved.

A live attenuated BCG vaccine overexpressing multistage antigens Ag85B and HspX provides superior protection against Mycobacterium tuberculosis infection.

PubMed

Yuan, Xuefeng; Teng, Xindong; Jing, Yukai; Ma, Jilei; Tian, Maopeng; Yu, Qi; Zhou, Lei; Wang, Ruibo; Wang, Weihua; Li, Li; Fan, Xionglin

2015-12-01

Tuberculosis (TB) remains one of the most menacing infectious diseases, although attenuated Mycobacterium bovis Bacillus Calmette-Guerin (BCG) vaccine has been widely used to protect children against primary TB. There are increasing evidences that rapid growing and dormant Mycobacterium tuberculosis (M. tuberculosis) coexist in vivo after infection. However, BCG vaccine only elicits cell-mediated immune responses to secretory antigens expressed by rapid growing pathogen. BCG vaccine is thus unable to thwart the reactivation of latent tuberculosis infection (LTBI), and its protection wanes over age after neonatal immunization. In order to extend its ability for a durable protection, a novel recombinant BCG (rBCG) strain, named rBCG::XB, was constructed by overexpressing immunodominant multistage antigens of Ag85B and HspX, which are expressed by both rapid replicating and dormant M. tuberculosis. Long-term protective effect and immunogenicity of rBCG::XB were compared with the parental BCG in vaccinated C57BL/6 mice. Our results demonstrated that rBCG::XB provided the stronger and long-lasting protection against M. tuberculosis H37Rv intranasal infection than BCG. The rBCG::XB not only elicited the more durable multistage antigen-specific CD4(+)Th1-biased immune responses and specific polyfunctional CD4(+)T cells but also augmented the CD8(+) CTL effects against Ag85B in vivo. In particular, higher levels of CD4(+) TEM and CD8(+) TCM cells, dominated by IL2(+) CD4(+) and CD8(+) TCM cells, were obtained in the spleen of rBCG::XB vaccinated mice. Therefore, our findings indicate that rBCG::XB is a promising candidate to improve the efficacy of BCG.

Trace elements distribution in hawksbill turtle (Eretmochelys imbricata) and green turtle (Chelonia mydas) tissues on the northern coast of Bahia, Brazil.

PubMed

de Macêdo, Gustavo R; Tarantino, Taiana B; Barbosa, Isa S; Pires, Thaís T; Rostan, Gonzalo; Goldberg, Daphne W; Pinto, Luis Fernando B; Korn, Maria Graças A; Franke, Carlos Roberto

2015-05-15

Concentrations of elements (As, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, Pb, Sb, Se, Sr, V, Zn) were determined in liver, kidneys and bones of Eretmochelys imbricata and Chelonia mydas specimens found stranded along the northern coast of Bahia, Brazil. Results showed that the concentrations of Cd, Cu, Ni and Zn in the liver and kidneys of juvenile C. mydas were the highest found in Brazil. We also observed a significant difference (p<0.05) on the bioaccumulation of trace elements between the two species: Al, Co, Mo, Na and Se in the liver; Al, Cr, Cu, K, Mo, Ni, Pb, Sr and V in the kidneys; and Al, Ba, Ca, Cd, Mn, Ni, Pb, Se, Sr and V in the bones. This study represents the first report on the distribution and concentration of trace elements in E. imbricata in the Brazilian coast. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dendritic Cells Regulate Treg-Th17 Axis in Obstructive Phase of Bile Duct Injury in Murine Biliary Atresia

PubMed Central

Tang, Shao-tao; Wang, Xin-xing; Cao, Guo-qing; Li, Shuai; Lei, Hai-yan; Zhang, Xi

2015-01-01

Several cell types are considered to be effector cells in bile duct injury in rhesus rotavirus (RRV)-induced experimental biliary atresia (BA). Here, we identified an increased T helper 17 (Th17) cell population in a BA mode. By depleting the Th17 cells, the BA symptoms (onset of jaundice, acholic stools and retarded growth) were attenuated and the survival rate was improved. Furthermore, we found that in mice with BA, the percentage of CD4+CD25highFoxp3+ T regulatory (Treg) cells decreased along with the increased percentage of Th17 cells. However, the absolute numbers of Treg and Th17 cells were both increased in liver of RRV-injected mice compared to saline-injected mice. The proportion of Th17 cells at 7 days post-infection was decreased if Treg cells isolated from normal adult mice, but not Treg cells from the livers of mice with BA, were intraperitoneally transferred on day 5 of life. In vitro experiments also showed that Treg cells from mice with BA had a diminished suppressive effect on Th17 cell generation. To determine the mechanisms, we investigated the production of cytokines in the liver. The level of IL-6, which has been shown to be abundantly secreted by activated dendritic cells (DCs), was remarkably elevated. Importantly, in a Treg/Th17 cell suppression assay, IL-6 was demonstrated to paralyze the Treg cells’ suppressive effect on Th17 cells and eventually the unrestrained increase of Th17 cells contributed to bile duct injury. In conclusion, the DC-regulated Treg-Th17 axis, probably in conjunction with other effector T cells, aggravates progressive inflammatory injury at the time of ductal obstruction. PMID:26325187

CD22 and Siglec-G in B cell function and tolerance

PubMed Central

Poe, Jonathan C.; Tedder, Thomas F.

2012-01-01

The immune system has evolved into two main arms, the primitive innate arm that is the first line of defense but relatively short-lived and broad acting, and the advanced adaptive arm that generates immunologic “memory” allowing rapid, specific recall responses. T cell-independent type-2 (TI-2) antigens (Ags) invoke innate immune responses. However, due to its “at the ready” nature, how the innate arm of the immune system maintains tolerance to potentially abundant host TI-2 Ags remains elusive. Therefore, it is important to define the mechanisms that establish innate immune tolerance. This review highlights recent insights into B cell tolerance to theoretical self TI-2 Ags, and examines how the B cell-restricted Siglecs, CD22 and Siglec-G, might contribute to this process. PMID:22677186

Electron Transport and Minority Carrier Lifetime in HgCdSe 2013 2-6 Workshop

DTIC Science & Technology

2014-03-11

FOR PUBLIC RELEASE Alternative IR Material 0.54 0.56 0.58 0.60 0.62 0.64 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 HgSe HgTe MgS ZnS MgTe CdS...CdSe ZnSe ZnTe CdTe AlP GaP AlSb InP Ge Si GaSb InSbInAs AlAs GaAs MgSe Ba nd ga p En er gy (e V) Lattice Constant (nm) • HgCdSe is being

Functional Magnetic Resonance Imaging Correlates of First-Episode Psychoses during Attentional and Memory Task Performance.

PubMed

Del Casale, Antonio; Kotzalidis, Georgios D; Rapinesi, Chiara; Sorice, Serena; Girardi, Nicoletta; Ferracuti, Stefano; Girardi, Paolo

2016-01-01

The nature of the alteration of the response to cognitive tasks in first-episode psychosis (FEP) still awaits clarification. We used activation likelihood estimation, an increasingly used method in evaluating normal and pathological brain function, to identify activation changes in functional magnetic resonance imaging (fMRI) studies of FEP during attentional and memory tasks. We included 11 peer-reviewed fMRI studies assessing FEP patients versus healthy controls (HCs) during performance of attentional and memory tasks. Our database comprised 290 patients with FEP, matched with 316 HCs. Between-group analyses showed that HCs, compared to FEP patients, exhibited hyperactivation of the right middle frontal gyrus (Brodmann area, BA, 9), right inferior parietal lobule (BA 40), and right insula (BA 13) during attentional task performances and hyperactivation of the left insula (BA 13) during memory task performances. Right frontal, parietal, and insular dysfunction during attentional task performance and left insular dysfunction during memory task performance are significant neural functional FEP correlates. © 2016 S. Karger AG, Basel.

Solid solution partitioning of Sr2+, Ba2+, and Cd2+ to calcite

USGS Publications Warehouse

Tesoriero, A.J.; Pankow, J.F.

1996-01-01

Although solid solutions play important roles in controlling the concentrations of minor metal ions in natural waters, uncertainties regarding their compositions, thermodynamics, and kinetics usually prevent them from being considered. A range of precipitation rates was used here to study the nonequilibrium and equilibrium partitioning behaviors of Sr2+, Ba2+, and Cd2+ to calcite (CaCO3(s)). The distribution coefficient of a divalent metal ion Me2+ for partitioning from an aqueous solution into calcite is given by DMe = (XMeCO3(s)/[Me2+])/(XCaCO3(s)/[Ca 2+]). The X values are solid-phase mole fractions; the bracketed values are the aqueous molal concentrations. In agreement with prior work, at intermediate to high precipitation rates R (nmol/mg-min), DSr, DBa, and DCd were found to depend strongly on R. At low R, the values of DSr, DBa, and DCd became constant with R. At 25??C, the equilibrium values for DSr, DBa, and DCd for dilute solid solutions were estimated to be 0.021 ?? 0.003, 0.012 ?? 0.005, and 1240 ?? 300, respectively. Calculations using these values were made to illustrate the likely importance of partitioning of these ions to calcite in groundwater systems. Due to its large equilibrium DMe value, movement of Cd2+ will be strongly retarded in aquifers containing calcite; Sr2+ and Ba2+ will not be retarded nearly as much.

Growth rate of YBCO-Ag superconducting single grains

NASA Astrophysics Data System (ADS)

Congreve, J. V. J.; Shi, Y. H.; Dennis, A. R.; Durrell, J. H.; Cardwell, D. A.

2017-12-01

The large scale use of (RE)Ba2Cu3O7 bulk superconductors, where RE=Y, Gd, Sm, is, in part, limited by the relatively poor mechanical properties of these inherently brittle ceramic materials. It is reported that alloying of (RE)Ba2Cu3O7 with silver enables a significant improvement in the mechanical strength of bulk, single grain samples without any detrimental effect on their superconducting properties. However, due to the complexity and number of inter-related variables involved in the top seeded melt growth (TSMG) process, the growth of large single grains is difficult and the addition of silver makes it even more difficult to achieve successful growth reliably. The key processing variables in the TSMG process include the times and temperatures of the stages within the heating profile, which can be derived from the growth rate during the growth process. To date, the growth rate of the YBa2Cu3O7-Ag system has not been reported in detail and it is this lacuna that we have sought to address. In this work we measure the growth rate of the YBCO-Ag system using a method based on continuous cooling and isothermal holding (CCIH). We have determined the growth rate by measuring the side length of the crystallised region for a number of samples for specified isothermal hold temperatures and periods. This has enabled the growth rate to be modelled and from this an optimized heating profile for the successful growth of YBCO-Ag single grains to be derived.

[The significances of peripheral neutrophils CD(55) and myeloperoxidase expression in patients with myeloperoxidase-specific anti-neutrophil cytoplasmic antibody associated vasculitis].

PubMed

Zhou, X L; Zheng, M J; Shuai, Z W; Zhang, L; Zhang, M M; Chen, S Y

2017-06-01

Objective: To investigate the expression of CD(55) and myeloperoxidase (MPO) on neutrophils in patients with MPO-specific anti-neutrophil cytoplasmic antibody associated vasculitis(MPO-AAV), and analyze the relationship between the expression and clinical manifestation. Methods: Forty untreated patients with active MPO-AAV (patient group) and 30 healthy volunteers (control group) were enrolled in this study. The CD(55) on neutrophils and both membrane and cytoplasmic MPO were detected by flow cytometry. Serum fragment-from the activated complement factor B(Ba) and MPO were measured by ELISA. The clinical activity of vasculitis was valued by Birmingham vasculitis activity score-version 3(BVAS-V3). The significance of laboratory data was evaluated by Spearman correlation test and multivariate linear regression analysis. Results: (1)The mean fluorescence intensity(MFI) of CD(55) expressed on neutrophils was significantly higher than that in control group[4 068.6±2 306.0 vs 2 999.5±1 504.9, P =0.033]. Similar results of serum MPO and Ba in patient group were found compared to controls [500.0(381.0, 612.7) IU/L vs 286.9(225.5, 329.1) IU/L, P <0.001; 35.2(25.2, 79.5) ng/L vs 18.0(15.0, 28.0) ng/L, P <0.001], respectively. However, MIF of cytoplasmic MPO in patients was significantly lower than that of control group(1 577.1±1 175.9 vs 3 105.3±2 323.0, P =0.003) . (2) In patient group, cytoplasmic intensity of MPO was negatively associated with the serum levels of MPO( r =-0.710, P <0.001) and Ba ( r =-0.589, P =0.001). Moreover, serum MPO was positively associated with serum Ba( r =0.691, P <0.001). Membrane intensity of CD(55) on neutrophils was positively correlated with patient age ( r =0.514, P =0.001), C reactive protein ( r =0.376, P =0.018), peripheral neutrophils count ( r =0.485, P =0.001) and BVAS-V3 ( r =0.484, P =0.002), whereas negative correlation between membrane CD(55) and disease duration was seen ( r =-0.403, P =0.01). (3) The result of multiple linear regression analysis showed there was statistically significant positive correlation between MFI of CD(55) expressed on neutrophils and BVAS-V3 (β=0.001, P =0.027). Conclusions: In MPO-AAV, CD(55) expression on neutrophils is markedly enhanced, which is one of the independent risk factors related to disease activity. It might protect neutrophils from attacking AAV, CD(55) expression on neutrophils is markedly enhanced, which is one of the independent risk factors related to disease activity. It might protect neutrophils from attacking by complement alternative pathway. Activated neutrophils release more MPO and lysosome to intensify the inflammation reaction and aggravate the disease. Thus CD(55) might become a new potential target for the treatment of this disease in the future.

CD8+ TCR repertoire formation is guided primarily by the peptide component of the antigenic complex.

PubMed

Koning, Dan; Costa, Ana I; Hoof, Ilka; Miles, John J; Nanlohy, Nening M; Ladell, Kristin; Matthews, Katherine K; Venturi, Vanessa; Schellens, Ingrid M M; Borghans, Jose A M; Kesmir, Can; Price, David A; van Baarle, Debbie

2013-02-01

CD8(+) T cells recognize infected or dysregulated cells via the clonotypically expressed αβ TCR, which engages Ag in the form of peptide bound to MHC class I (MHC I) on the target cell surface. Previous studies have indicated that a diverse Ag-specific TCR repertoire can be beneficial to the host, yet the determinants of clonotypic diversity are poorly defined. To better understand the factors that govern TCR repertoire formation, we conducted a comprehensive clonotypic analysis of CD8(+) T cell populations directed against epitopes derived from EBV and CMV. Neither pathogen source nor the restricting MHC I molecule were linked with TCR diversity; indeed, both HLA-A and HLA-B molecules were observed to interact with an overlapping repertoire of expressed TRBV genes. Peptide specificity, however, markedly impacted TCR diversity. In addition, distinct peptides sharing HLA restriction and viral origin mobilized TCR repertoires with distinct patterns of TRBV gene usage. Notably, no relationship was observed between immunodominance and TCR diversity. These findings provide new insights into the forces that shape the Ag-specific TCR repertoire in vivo and highlight a determinative role for the peptide component of the peptide-MHC I complex on the molecular frontline of CD8(+) T cell-mediated immune surveillance.

Enhancement in transport critical current density of ex situ PIT Ag/(Ba, K)Fe2As2 tapes achieved by applying a combined process of flat rolling and uniaxial pressing

NASA Astrophysics Data System (ADS)

Togano, Kazumasa; Gao, Zhaoshun; Matsumoto, Akiyoshi; Kumakura, Hiroaki

2013-11-01

We report that the transport critical current density Jc of ex situ powder-in-tube (PIT) processed (Ba, K)Fe2As2 (Ba-122) tapes can be significantly enhanced by applying uniaxial cold pressing at the final stage of deformation. The tapes were prepared by packing high quality precursor powder into a Ag tube, cycles of rolling and intermediate annealing, and pressing followed by the final heat treatment for sintering. The Jc values in applied magnetic fields were increased by almost one order of magnitude compared to the tapes processed without pressing, exceeding 104 A cm-2 at 4.2 K. We achieved the highest Jc (at 4.2 K and 10 T) of 2.1×104 A cm-2 among PIT-processed Fe-based wires and tapes reported so far. The Jc-H curves measured at higher temperatures maintain small field dependence up to around 20 K, suggesting that these tapes are promising for applications at higher temperatures as well as at liquid helium temperature. The microstructure investigations reveal that there are two possible causes of the large Jc enhancement by pressing: one is densification and the other is the change of crack structure. Optimization of processing parameters such as the reduction ratio of rolling and pressing is expected to yield further Jc enhancement.

Two roles for CD4 cells in the control of the generation of cytotoxic T lymphocytes.

PubMed

Cassell, D; Forman, J

1991-01-01

The generation of CTL against Qa-1 Ag in C57BL/6 (B6) (Qa-1b) and B6.Tlaa (Qa-1a) congenic strains requires in vivo priming with the Qa-1 alloantigen together with a helper Ag, such as H-Y. The primed precursors obtained from these female mice generate Qa-1-specific CTL activity upon culture in vitro. Although the presence of the H-Y helper Ag is not required for the in vitro sensitization, no response occurs in the absence of CD4 cells. Addition of unprimed B6.Tlaa CD4 cells from Qa-1 incompatible radiation bone marrow chimeras (B6.Tlaa----B6), that are presumably tolerant to Qa-1b, provide helper activity for Qa-1b-specific CTL. This indicates that although CD4 cells are obligatory for the Qa-1 response, they need not be specific for alloantigens on the APC to generate helper activity in in vitro cultures. Addition of unirradiated B6 CD8-depleted spleen cells to CD4-depleted B6.Tlaa anti-B6 cultures in the presence of either B6.Tlaa CD4 cells or rIL-2 prevents the generation of Qa-1 specific CTL. This inhibition is not due to an anti-idiotypic Ts cell since B6.Tlaa----B6 chimeric cells do not suppress an anti-Qa-1b response. Rather, this finding is consistent with that of a veto cell mechanism. To determine whether CD4 cells themselves exhibit veto activity, highly purified CD4 populations were tested for their ability to inhibit the generation of Qa-1-specific CTL. CD4 cells precultured for 2 to 3 days with Con A and rIL-2 specifically inhibit CTL activity whereas resting cells do not, similar to that noted for CD8 veto cells. The relative efficiency of activated CD4 cells is greater than that of resting NK cells but is less than that of activated CD8 or NK cells. Thus, CD4 cells not only provide helper activity for CTL precursors, but also act as veto cells to prevent the generation of CTL activity.

Renal Allograft Survival in Nonhuman Primates Infused With Donor Antigen-Pulsed Autologous Regulatory Dendritic Cells.

PubMed

Ezzelarab, M B; Raich-Regue, D; Lu, L; Zahorchak, A F; Perez-Gutierrez, A; Humar, A; Wijkstrom, M; Minervini, M; Wiseman, R W; Cooper, D K C; Morelli, A E; Thomson, A W

2017-06-01

Systemic administration of autologous regulatory dendritic cells (DCreg; unpulsed or pulsed with donor antigen [Ag]), prolongs allograft survival and promotes transplant tolerance in rodents. Here, we demonstrate that nonhuman primate (NHP) monocyte-derived DCreg preloaded with cell membrane vesicles from allogeneic peripheral blood mononuclear cells induce T cell hyporesponsiveness to donor alloantigen (alloAg) in vitro. These donor alloAg-pulsed autologous DCreg (1.4-3.6 × 10 6 /kg) were administered intravenously, 1 day before MHC-mismatched renal transplantation to rhesus monkeys treated with costimulation blockade (cytotoxic T lymphocyte Ag 4 immunoglobulin [CTLA4] Ig) and tapered rapamycin. Prolongation of graft median survival time from 39.5 days (no DCreg infusion; n = 6 historical controls) and 29 days with control unpulsed DCreg (n = 2), to 56 days with donor Ag-pulsed DCreg (n = 5) was associated with evidence of modulated host CD4 + and CD8 + T cell responses to donor Ag and attenuation of systemic IL-17 production. Circulating anti-donor antibody (Ab) was not detected until CTLA4 Ig withdrawal. One monkey treated with donor Ag-pulsed DCreg rejected its graft in association with progressively elevated anti-donor Ab, 525 days posttransplant (160 days after withdrawal of immunosuppression). These findings indicate a modest but not statistically significant beneficial effect of donor Ag-pulsed autologous DCreg infusion on NHP graft survival when administered with a minimal immunosuppressive drug regimen. © 2016 The American Society of Transplantation and the American Society of Transplant Surgeons.

Discontinuous precipitation in a Cd-6 at.% Ag alloy

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

Manna, I.; Bala, P.K.; Pabi, S.K.

1996-11-01

Discontinuous precipitation (DP) in a Cd-6 at.% Ag alloy has been investigated for the first time. The precipitate phase maintains a lamellar morphology and statistically constant interlamellar spacing under a given isothermal condition in the temperature range studied (333--523 K). The interlamellar spacing increases with an increase in isothermal temperature. The reaction front velocity registers a typical C-curve variation with the inverse of temperature. The reaction rate is maximum at 470 K. The predicted upper limit of DP occurrence in this alloy is 23 K lower than the concerned equilibrium solvus temperature. Continuous precipitation accompanies DP at all temperatures, especiallymore » beyond a certain time, and adversely affects the growth kinetics of DP colonies by reducing the local chemical driving force and/or posing physical hindrance to the reaction front migration. An extensive kinetic analysis of DP using the models by Turnbull, Aaronson and Liu, and Petermann and Hornbogen has yielded the grain boundary chemical diffusivity data in Cd-6 At.% Ag for the first time, the activation energy of which lies in the range 55--77 kJ/mol.« less

Antigen Availability Shapes T Cell Differentiation and Function during Tuberculosis.

PubMed

Moguche, Albanus O; Musvosvi, Munyaradzi; Penn-Nicholson, Adam; Plumlee, Courtney R; Mearns, Helen; Geldenhuys, Hennie; Smit, Erica; Abrahams, Deborah; Rozot, Virginie; Dintwe, One; Hoff, Søren T; Kromann, Ingrid; Ruhwald, Morten; Bang, Peter; Larson, Ryan P; Shafiani, Shahin; Ma, Shuyi; Sherman, David R; Sette, Alessandro; Lindestam Arlehamn, Cecilia S; McKinney, Denise M; Maecker, Holden; Hanekom, Willem A; Hatherill, Mark; Andersen, Peter; Scriba, Thomas J; Urdahl, Kevin B

2017-06-14

CD4 T cells are critical for protective immunity against Mycobacterium tuberculosis (Mtb), the cause of tuberculosis (TB). Yet to date, TB vaccine candidates that boost antigen-specific CD4 T cells have conferred little or no protection. Here we examined CD4 T cell responses to two leading TB vaccine antigens, ESAT-6 and Ag85B, in Mtb-infected mice and in vaccinated humans with and without underlying Mtb infection. In both species, Mtb infection drove ESAT-6-specific T cells to be more differentiated than Ag85B-specific T cells. The ability of each T cell population to control Mtb in the lungs of mice was restricted for opposite reasons: Ag85B-specific T cells were limited by reduced antigen expression during persistent infection, whereas ESAT-6-specific T cells became functionally exhausted due to chronic antigenic stimulation. Our findings suggest that different vaccination strategies will be required to optimize protection mediated by T cells recognizing antigens expressed at distinct stages of Mtb infection. Copyright © 2017 Elsevier Inc. All rights reserved.

Survival with AGS-003, an autologous dendritic cell-based immunotherapy, in combination with sunitinib in unfavorable risk patients with advanced renal cell carcinoma (RCC): Phase 2 study results.

PubMed

Amin, Asim; Dudek, Arkadiusz Z; Logan, Theodore F; Lance, Raymond S; Holzbeierlein, Jeffrey M; Knox, Jennifer J; Master, Viraj A; Pal, Sumanta K; Miller, Wilson H; Karsh, Lawrence I; Tcherepanova, Irina Y; DeBenedette, Mark A; Williams, W Lee; Plessinger, Douglas C; Nicolette, Charles A; Figlin, Robert A

2015-01-01

AGS-003 is an autologous immunotherapy prepared from fully matured and optimized monocyte-derived dendritic cells, which are co-electroporated with amplified tumor RNA plus synthetic CD40L RNA. AGS-003 was evaluated in combination with sunitinib in an open label phase 2 study in intermediate and poor risk, treatment naïve patients with metastatic clear cell renal cell carcinoma (mRCC). Twenty-one intermediate and poor risk patients were treated continuously with sunitinib (4 weeks on, 2 weeks off per 6 week cycle). After completion of the first cycle of sunitinib, patients were treated with AGS-003 every 3 weeks for 5 doses, then every 12 weeks until progression or end of study. The primary endpoint was to determine the complete response rate. Secondary endpoints included clinical benefit, safety, progression free survival (PFS) and overall survival (OS). Immunologic response was also monitored. Thirteen patients (62%) experienced clinical benefit (9 partial responses, 4 with stable disease); however there were no complete responses in this group of intermediate and poor risk mRCC patients and enrollment was terminated early. Median PFS from registration was 11.2 months (95% CI 6.0, 19.4) and the median OS from registration was 30.2 months (95% CI 9.4, 57.1) for all patients. Seven (33%) patients survived for at least 4.5 years, while five (24%) survived for more than 5 years, including 2 patients who remain progression-free with durable responses for more than 5 years at the time of this report. AGS-003 was well tolerated with only mild injection-site reactions. The most common adverse events were related to expected toxicity from sunitinib therapy. In patients who had sequential samples available for immune monitoring, the magnitude of the increase in the absolute number of CD8(+) CD28(+) CD45RA(-) effector/memory T cells (CTLs) after 5 doses of AGS-003 relative to baseline, correlated with overall survival. AGS-003 in combination with sunitinib was well tolerated and yielded supportive immunologic responses coupled with extension of median and long-term survival in an unselected, intermediate and poor risk prognosis mRCC population. #NCT00678119.

International Conference (4th) on Nanostructured Materials Held in Stockholm, Sweden on 14-19 June 1998. Book of Abstracts

DTIC Science & Technology

1998-06-19

Coatings P2-67 Kuruvilla, B.A.; Nanda, J.; Sarma, D.D.; India Optical Properties ofPbS- CdS Coated Semiconductor Nanoparticles P2-68 Misra, S.; India...including phosphors, pigments and magnetic materials. In this study, the synthesis of ZnS, CdS and Ce2S3 nanoparticles by mechanochemical reaction has...formation of separated nanoparticles ; ZnS, CdS and Ce2S3 nanoparticles of ~7 nm, ɠ nm and -20 nm, respectively, were obtained. The average size of CdS

Characterization of a human antigen specific helper factor

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

Richardson, B.

1986-03-01

While antigen (Ag) specific helper factors have been characterized in mice, similar molecules have not been identified in humans. To characterize human antigen specific helper molecules, an IL-2 dependent tetanus toxoid (T.T.) reactive T cell line was fused with a 6-thioguanine resistant CEM line, and hybrids selected in medium containing hypoxanthine and azaserine. Hybrids were screened by culturing the cells with /sup 35/S-Met then reacting the supernatants with T.T. or hepatitis vaccine immobilized on nitrocellulose. One hybrid, TT6BA-O, was identified which secreted a Met-containing molecule which bound T.T. but not hepatitis vaccine. Supernatants from TT6BA-O, but not the parent CEMmore » line, when added to autologous peripheral blood mononuclear cells (PBMC's) stimulated secretion of T.T. specific antibodies (Abs). Specificity controls demonstrated that TT6BA-O supernatant did not induce antibodies to diphtheria toxoid, hepatitis vaccine or pneumococcal polysaccharide, and total immunoglobulin (lg) synthesis was minimally increased. In contrast, pokeweed mitogen stimulated significant lg synthesis as well as Ab's to pneumococcal polysaccharide and T.T. TT6BA-O supernatant induced anti-T.T.Ab's in autologous PBMC's but not PBMC's from 3 unrelated donors, suggesting that the activity of the helper factor is restricted, possibly by the MHC. The molecular weight of the helper factor was estimated at 100,000-150,000 by Sephacryl S-300 chromatography. Finally, the helper factor could be demonstrated to bind and elute from sephorose-immobilized T.T. and anti-DR antisera, but not anti-lg antisera or the T40/25 monoclonal antibody, which binds a nonpolymorphic determinant on the human T cell receptor. These results demonstrate that human Ag specific helper factors exist, bind antigen and bear class II MHC determinants.« less

Benzo(a)pyrene quinones increase cell proliferation, generate reactive oxygen species, and transactivate the epidermal growth factor receptor in breast epithelial cells.

PubMed

Burdick, Andrew D; Davis, John W; Liu, Ke Jian; Hudson, Laurie G; Shi, Honglian; Monske, Michael L; Burchiel, Scott W

2003-11-15

Polycyclic aromatic hydrocarbons, such as benzo(a)pyrene (BaP), are known mammary carcinogens in rodents and may be involved in human breast cancer. We have reported previously that BaP can mimic growth factor signaling and increase cell proliferation in primary human mammary epithelial cells and the human mammary epithelial cell line MCF-10A. BaP-quinones (BPQs) are important metabolites of BaP that have been associated with the production of reactive oxygen species. Using a model of epidermal growth factor (EGF) withdrawal in MCF-10A, we hypothesized that production of reactive oxygen species by BPQs could lead to the activation of the EGF receptor (EGFR). Here, we demonstrate through electron paramagnetic resonance spectroscopy and flow cytometry that 1,6-BPQ and 3,6-BPQ produce superoxide anion and hydrogen peroxide in MCF-10A cells. Furthermore, we show that BPQs increase EGFR, Akt, and extracellular signal-regulated kinase activity, leading to increased cell number in the absence of EGF. The BPQ-induced EGFR activity and associated cell proliferation were attenuated by the EGFR inhibitor AG1478, as well as by the antioxidant N-acetyl cysteine. Overexpression of catalase, but not Cu/Zn superoxide dismutase, reduced the extent of BPQ-dependent increased cell number and EGFR pathway activation. Moreover, the direct treatment of MCF-10A cells with hydrogen peroxide enhanced EGFR, Akt, and extracellular-regulated kinase phosphorylation that could be similarly inhibited by AG1478, N-acetyl cysteine, and catalase. Taken together, these data indicate that BPQs, through the generation of hydrogen peroxide, activate the EGFR in MCF-10A cells, leading to increased cell number under EGF-deficient conditions.

Atmospheric trace element concentrations in total suspended particles near Paris, France

NASA Astrophysics Data System (ADS)

Ayrault, Sophie; Senhou, Abderrahmane; Moskura, Mélanie; Gaudry, André

2010-09-01

To evaluate today's trace element atmospheric concentrations in large urban areas, an atmospheric survey was carried out for 18 months, from March 2002 to September 2003, in Saclay, nearby Paris. The total suspended particulate matter (TSP) was collected continuously on quartz fibre filters. The TSP contents were determined for 36 elements (including Ag, Bi, Mo and Sb) using two analytical methods: Instrumental Neutron Activation Analysis (INAA) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The measured concentrations were in agreement within the uncertainties with the certified values for the polycarbonate reference material filter SRM-2783 (National Institute for Standard Technology NIST, USA). The measured concentrations were significantly lower than the recommended atmospheric concentrations. In 2003, the Pb atmospheric level at Saclay was 15 ng/m 3, compared to the 500 ng/m 3 guideline level and to the 200 ng/m 3 observed value in 1994. The typical urban background TSP values of 1-2, 0.2-1, 4-6, 10-30 and 3-5 ng/m 3 for As, Co, Cr, Cu and Sb, respectively, were inferred from this study and were compared with the literature data. The typical urban background TSP concentrations could not be realised for Cd, Pb and Zn, since these air concentrations are highly influenced by local features. The Zn concentrations and Zn/Pb ratio observed in Saclay represented a characteristic fingerprint of the exceptionally large extent of zinc-made roofs in Paris and its suburbs. The traffic-related origin of Ba, Cr, Cu, Pb and Sb was demonstrated, while the atmospheric source(s) of Ag was not identified.

Genetic and physiological responses of Bacillus subtilis to metal ion stress.

PubMed

Moore, Charles M; Gaballa, Ahmed; Hui, Monica; Ye, Rick W; Helmann, John D

2005-07-01

Metal ion homeostasis is regulated principally by metalloregulatory proteins that control metal ion uptake, storage and efflux genes. We have used transcriptional profiling to survey Bacillus subtilis for genes that are rapidly induced by exposure to high levels of metal ions including Ag(I), Cd(II), Cu(II), Ni(II) and Zn(II) and the metalloid As(V). Many of the genes affected by metal stress were controlled by known metalloregulatory proteins (Fur, MntR, PerR, ArsR and CueR). Additional metal-induced genes are regulated by two newly defined metal-sensing ArsR/SmtB family repressors: CzrA and AseR. CzrA represses the CadA efflux ATPase and the cation diffusion facilitator CzcD and this repression is alleviated by Zn(II), Cd(II), Co(II), Ni(II) and Cu. CadA is the major determinant for Cd(II) resistance, while CzcD protects the cell against elevated levels of Zn(II), Cu, Co(II) and Ni(II). AseR negatively regulates itself and AseA, an As(III) efflux pump which contributes to arsenite resistance in cells lacking a functional ars operon. Our results extend the range of identified effectors for the As(III)-sensor ArsR to include Cd(II) and Ag(I) and for the Cu-sensor CueR to include Ag(I) and, weakly, Cd(II) and Zn(II). In addition to systems dedicated to metal homeostasis, specific metal stresses also strongly induced pathways related to cysteine, histidine and arginine metabolism.

[Effect of cellular immune supportive treatment on immunity of esophageal carcinoma patients after modern two-field lymph node dissection].

PubMed

Wang, Jun-Ye; Ma, Guo-Wei; Dai, Shu-Qin; Rong, Tie-Hua; Wang, Xin; Lin, Peng; Ye, Wen-Feng; Zhang, Lan-Jun; Li, Xiao-Dong; Zhang, Xu; Yao, Guang-Yu

2007-07-01

Cellular immunity suppression is marked in patients with esophageal carcinoma, which may be resulted temporarily from surgical injury. This study was to evaluate the effect of cellular immune supportive treatment on cellular immunity of patients with esophageal carcinoma. A total of 60 patients with thoracic esophageal carcinoma, received two-field dissection, were randomized into control group and trial (immune supportive treatment) group. The patients in trial group were injected with Shenqi injection after operation; the patients in control group received no immune supportive treatment. Peripheral blood samples were obtained before operation, and 3 and 9 days after operation. AgNOR (argyrophilic nucleolar organizer regions) activity in peripheral blood T lymphocytes was measured by tumor immune microphotometry. T cell subsets were measured by flow cytometry. The proportions of CD3+CD4+ and CD4+/CD8+ cells were significantly higher in trial group than in control group at 3 days after operation (P < 0.05). The amount of AgNOR and proportions of CD3+, CD3+CD4+, CD4+/CD8+, and CD4+CD25+ cells were significantly higher in trial group than in control group at 9 days after operation (P < 0.05). There was no significant difference in 1-year survival rate between the 2 groups (P > 0.05). Shenqi injection could obviously improve cellular immunity of the esophageal carcinoma patients after modern two-field dissection.

Ag-doped CdO nanocatalysts: Preparation, characterization and catechol oxidase activity

NASA Astrophysics Data System (ADS)

El-Kemary, Maged; El-Mehasseb, Ibrahim; El-Shamy, Hany

2018-06-01

Silver doped cadmium oxide (Ag/CdO) nanoparticles with an average size of 41 nm have been successfully synthesized via thermal decomposition and liquid impregnation technique. The structural characterization has been performed by using several spectroscopic techniques, e.g., X-ray diffraction (XRD), scanning electron microscopy (SEM) and fourier-transform infrared (FT-IR). The catechol oxidase has been studied by UV-visible absorption spectroscopy and fourier-transform infrared as well as the mechanism has been assured by cyclic voltammetry and fluorescence spectroscopy. The results indicate that the oxidation does not occur in the presence of unsupported cadmium oxide particles by silver and in the same time, the catechol oxidase activity of silver doped CdO nanoparticles were improved by about three orders of magnitude than silver ions.

CdS-Nanowires Flexible Photo-detector with Ag-Nanowires Electrode Based on Non-transfer Process

PubMed Central

Pei, Yanli; Pei, Ruihan; Liang, Xiaoci; Wang, Yuhao; Liu, Ling; Chen, Haibiao; Liang, Jun

2016-01-01

In this study, UV-visible flexible resistivity-type photo-detectors were demonstrated with CdS-nanowires (NWs) percolation network channel and Ag-NWs percolation network electrode. The devices were fabricated on Mixed Cellulose Esters (MCE) membrane using a lithographic filtration method combined with a facile non-transfer process. The photo-detectors demonstrated strong adhesion, fast response time, fast decay time, and high photo sensitivity. The high performance could be attributed to the high quality single crystalline CdS-NWs, encapsulation of NWs in MCE matrix and excellent interconnection of the NWs. Furthermore, the sensing performance was maintained even the device was bent at an angle of 90°. This research may pave the way for the facile fabrication of flexible photo-detectors with high performances. PMID:26899726

Targeting with bovine CD154 enhances humoral immune responses induced by a DNA vaccine in sheep.

PubMed

Manoj, Sharmila; Griebel, Philip J; Babiuk, Lorne A; van Drunen Littel-van den Hurk, Sylvia

2003-01-15

CD40-CD154 interactions play an important role in regulating humoral and cell-mediated immune responses. Recently, these interactions have been exploited for the development of therapeutic and preventive treatments. The objective of this study was to test the ability of bovine CD154 to target a plasmid-encoded Ag to CD40-expressing APCs. To achieve this, a plasmid coding for bovine CD154 fused to a truncated secreted form of bovine herpesvirus 1 glycoprotein D (tgD), pSLIAtgD-CD154, was constructed. The chimeric tgD-CD154 was expressed in vitro in COS-7 cells and reacted with both glycoprotein D- and CD154-specific Abs. Both tgD and tgD-CD154 were capable of binding to epithelial cells, whereas only tgD-CD154 bound to B cells. Furthermore, dual-labeling of ovine PBMCs revealed that tgD-CD154 was bound by primarily B cells. The functional integrity of the tgD-CD154 chimera was confirmed by the induction of both IL-4-dependent B cell proliferation and tgD-specific lymphoproliferative responses in vitro. Finally, sheep immunized with pSLIAtgD-CD154 developed a more rapid primary tgD-specific Ab response and a significantly stronger tgD-specific secondary response when compared with animals immunized with pSLIAtgD and control animals. Similarly, virus-neutralizing Ab titers were significantly higher after secondary immunization with pSLIAtgD-CD154. These results demonstrate that using CD154 to target plasmid-expressed Ag can significantly enhance immune responses induced by a DNA vaccine.

Plasma Renalase is Not Associated with Blood Pressure and Brachial-Ankle Pulse Wave Velocity in Chinese Adults With Normal Renal Function.

PubMed

Wang, Yang; Lv, Yong-Bo; Chu, Chao; Wang, Man; Xie, Bing-Qing; Wang, Lan; Yang, Fan; Yan, Ding-Yi; Yang, Rui-Hai; Yang, Jun; Ren, Yong; Yuan, Zu-Yi; Mu, Jian-Jun

2016-01-01

This study aimed to investigate the association of renalase with blood pressure (BP) and brachial-ankle pulse wave velocity (baPWV) in order to better understand the role of renalase in the pathogenesis of hypertension and atherosclerosis. A total of 344 subjects with normal kidney function were recruited from our previously established cohort in Shaanxi Province, China. They were divided into the normotensive (NT) and hypertensive (HT) groups or high baPWV and normal baPWV on the basis of BP levels or baPWV measured with an automatic waveform analyzer. Plasma renalase was determined through an enzyme-linked immunosorbent assay. Plasma renalase did not significantly differ between HT and NT groups (3.71 ± 0.69 µg/mL vs. 3.72 ± 0.73 μg/mL, P = 0.905) and between subjects with and without high baPWV (3.67 ± 0.66 µg/mL vs. 3.73 ± 0.74 µg/mL, P = 0.505). However, baPWV was significantly higher in the HT group than in the NT group (1460.4 ± 236.7 vs. 1240.7 ± 174.5 cm/s, P < 0.001). Plasma renalase was not correlated with BP levels and baPWV in the entire group. Linear and logistic regression analysis revealed that plasma renalase was not significantly associated with hypertension and high baPWV. Plasma renalase may not be associated with BP and baPWV in Chinese subjects with normal renal function. © 2016 The Author(s) Published by S. Karger AG, Basel.

CD4+ T cells spontaneously producing human immunodeficiency virus type I in breast milk from women with or without antiretroviral drugs

PubMed Central

2011-01-01

Background Transmission of human immunodeficiency virus type 1 (HIV-1) through breast-feeding may involve both cell-free and cell-associated virus. This latter viral reservoir remains, however, to be fully explored. CD4+ T cell-associated virus production in breast milk was therefore investigated. Methods The ex vivo spontaneous production of HIV-1 antigen and HIV-1 RNA by CD4+ T cells was measured in paired blood and breast milk samples from 15 HIV-1 infected women treated or not with antiretroviral drugs. Spontaneous antigen secreting cells (HIV-1-AgSCs) from breast milk and blood were enumerated by an ELISpot assay, and cell-associated HIV-1 RNA was quantified by real-time PCR in supernatants of CD4+ T cells cultured for 18 hours without addition of polyclonal activators. Results Among the CD4+ T cells present in breast milk, memory cells expressing high levels of cell-surface activation markers were predominant. Spontaneous HIV-1-AgSCs were detected and enumerated in the breast milk of all 15 women, with a median number of 13.0 and 9.5 HIV-1- AgSCs/106 CD4+ T cells in aviremic (n = 7) and viremic (n = 8) women, respectively. Cell- associated HIV-1 RNA was detected in cell-free supernatants from 4/7 aviremic and 5/8 viremic individuals at median levels of 190 and 245 copies/ml, respectively. Conclusions Activated CD4+ T cells producing HIV-1 are detected in the breast milk of untreated individuals as well as those receiving highly active antiretroviral therapy. This finding strongly suggests that HIV-1 replication occurs in latently infected CD4+ T cells that, upon spontaneous activation, revert to productively infected cells. These cells might be responsible for a residual breast milk transmission despite maternal highly active antiretroviral therapy. PMID:21569457

Effects of divalent cations and La3+ on contractility and ecto-ATPase activity in the guinea-pig urinary bladder.

PubMed Central

Ziganshin, A U; Ziganshina, L E; Hoyle, C H; Burnstock, G

1995-01-01

1. Several cations (Ba2+, Cd2+, Co2+, Cu2+, Mn2+, Ni2+, Zn2+ and La3+, all as chloride salts, 1-1000 microM) were tested in the guinea-pig urinary bladder for their ability to: (i) modify contractile responses to electrical field stimulation (EFS), ATP, alpha,beta-methylene ATP (alpha,beta-meATP), carbachol (CCh), and KCl; (ii) affect ecto-ATPase activity. 2. Ba2+ (10-1000 microM) concentration-dependently potentiated contractile responses evoked by EFS (4-16 Hz), ATP (100 microM), alpha,beta-meATP (1 microM), CCh (0.5 microM), and KCl (30 mM). Ni2+ at concentrations of 1-100 microM also potentiated contractility of the urinary bladder, but at concentrations tested its effect was not concentration-dependent. Cu2+ at a concentration of 10 microM and Cd2+ at a concentration of 1 microM potentiated responses to all stimuli, except KCl. Ni2+ at a concentration of 1000 microM and Cd2+ at a concentration of 100 microM inhibited contractions evoked by all stimuli, and at a concentration of 1000 microM Cd2+ abolished any contractions. Responses to ATP and alpha,beta-meATP were selectively inhibited by Cu2+, Zn2+ or La3+, each at a concentration of 1 mM. 3. Cu2+, Ni2+, Zn2+ and La3+ (100-1000 microM) concentration-dependently inhibited ecto-ATPase activity in the urinary bladder smooth muscle preparations, while Ba2+ and Mn2+ were without effect, and Cd2+ and Co2+ caused significant inhibition only at a concentration of 1000 microM. 4. There was no correlation between the extent of ecto-ATPase inhibition and the effect on contractile activity of any of the cations.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7735690

Protective effect of boric acid on lead- and cadmium-induced genotoxicity in V79 cells.

PubMed

Ustündağ, Aylin; Behm, Claudia; Föllmann, Wolfram; Duydu, Yalçin; Degen, Gisela H

2014-06-01

The toxic heavy metals cadmium (Cd) and lead (Pb) are important environmental pollutants which can cause serious damage to human health. As the metal ions (Cd(2+) and Pb(2+)) accumulate in the organism, there is special concern regarding chronic toxicity and damage to the genetic material. Metal-induced genotoxicity has been attributed to indirect mechanisms, such as induction of oxidative stress and interference with DNA repair. Boron is a naturally occurring element and considered to be an essential micronutrient, although the cellular activities of boron compounds remain largely unexplored. The present study has been conducted to evaluate potential protective effects of boric acid (BA) against genotoxicity induced by cadmium chloride (CdCl2) and lead chloride (PbCl2) in V79 cell cultures. Cytotoxicity assays (neutral red uptake and cell titer blue assay) served to determine suitable concentrations for subsequent genotoxicity assays. Chromosomal damage and DNA strand breaks were assessed by micronucleus tests and comet assays. Both PbCl2 and CdCl2 (at 3, 5 and 10 µM) were shown to induce concentration-dependent increases in micronucleus frequencies and DNA strand breaks in V79 cells. BA itself was not cytotoxic (up to 300 µM) and showed no genotoxic effects. Pretreatment of cells with low levels of BA (2.5 and 10 µM) was found to strongly reduce the genotoxic effects of the tested metals. Based on the findings of this in vitro study, it can be suggested that boron provides an efficient protection against the induction of DNA strand breaks and micronuclei by lead and cadmium. Further studies on the underlying mechanisms for the protective effect of boron are needed.

Embedded Ag/Ni Metal-Mesh with Low Surface Roughness As Transparent Conductive Electrode for Optoelectronic Applications.

PubMed

Chen, Xiaolian; Guo, Wenrui; Xie, Liming; Wei, Changting; Zhuang, Jinyong; Su, Wenming; Cui, Zheng

2017-10-25

Metal-mesh is one of the contenders to replace indium tin oxide (ITO) as transparent conductive electrodes (TCEs) for optoelectronic applications. However, considerable surface roughness accompanying metal-mesh type of transparent electrodes has been the root cause of electrical short-circuiting for optoelectronic devices, such as organic light-emitting diode (OLED) and organic photovoltaic (OPV). In this work, a novel approach to making metal-mesh TCE has been proposed that is based on hybrid printing of silver (Ag) nanoparticle ink and electroplating of nickel (Ni). By polishing back the electroplated Ni, an extremely smooth surface was achieved. The fabricated Ag/Ni metal-mesh TCE has a surface roughness of 0.17 nm, a low sheet resistance of 2.1 Ω/□, and a high transmittance of 88.6%. The figure of merit is 1450, which is 30 times better than ITO. In addition, the Ag/Ni metal-mesh TCE shows outstanding mechanical flexibility and environmental stability at high temperature and humidity. Using the polished Ag/Ni metal-mesh TCE, a flexible quantum dot light-emitting diode (QLED) was fabricated with an efficiency of 10.4 cd/A and 3.2 lm/W at 1000 cd/m 2 .

Inhibition of IGF-1 receptor kinase blocks the differentiation into cardiomyocyte-like cells of BMSCs induced by IGF-1.

PubMed

Gong, Haibin; Wang, Xiuli; Wang, Lei; Liu, Ying; Wang, Jie; Lv, Qian; Pang, Hui; Zhang, Qinglin; Wang, Zhenquan

2017-07-01

Bone marrow mesenchymal stem cells (BMSCs) have the potential to transdifferentiate into cardiomyocyte‑like cells (CLCs) if an appropriate cardiac environment is provided. Insulin‑like growth factor‑1 (IGF‑1) plays an important role in the cell migration, survival and differentiation of BMSCs. However, the effect of IGF‑1 on the cellular differentiation remains unclear. In the present study, BMSCs were isolated from rat femurs and tibias and the cells were purified at passage 6 (P6). IGF‑1 and IGF‑1 receptor (IGF‑1R) kinase inhibitor I‑OMe AG538 were added to detect if IGF‑1 could induce BMSCs to transdifferentiate into CLCs and if I‑OMe AG538 could inhibit IGF‑1‑mediated receptor activation and downstream signaling. Immunostaining demonstrated that all P6 BMSCs express CD29 and CD44 but not CD45. BMSCs induced by 15 ng/ml IGF‑1 revealed positivity for cardiac troponin‑T and cardiac troponin‑I. The optimal induction time was 14 days but the expression of these proteins were incompletely inhibited by 300 nmol/l I‑OMe AG538 and completely inhibited by 10 µmol/l I‑OMe AG538. Western blotting showed that the level of IGF‑1R autophosphorylation and the expression of cTnT and cTnI were higher when BMSCs were induced for 14 days. I‑OMe AG538 selectively inhibited IGF‑1‑mediated growth and signal transduction and the inhibitory effect of I‑OMe AG538 were not reverted in the presence of exogenous IGF‑1. In addition, when a time course analysis of the effects of I‑OMe AG538 on mitogen‑activated protein kinase kinase and phosphatidylinositol 3‑kinase signaling were done, we observed a transient inhibitory effect on Erk1/2 and Akt phosphorylation, in keeping with the inhibitory effects on cell growth. Taken together, these data indicate that I‑OMe AG538 could inhibit IGF-1-induced CLCs in BMSCs and this effect is time- and concentration-dependent.

A distinct dendritic cell population arises in the thymus of IL-13Rα1-sufficient but not IL-13Rα1-deficient mice.

PubMed

Barik, Subhasis; Miller, Mindy; Cattin-Roy, Alexis; Ukah, Tobechukwu; Zaghouani, Habib

2018-06-18

IL-13 receptor alpha 1 (IL-13Rα1) associates with IL-4Rα to form a functional IL-4Rα/IL-13Rα1 heteroreceptor (HR) through which both IL-4 and IL-13 signal. Recently, HR expression was associated with the development of M2 type macrophages which function as antigen presenting cells (APCs). Herein, we show that a subset of thymic resident dendritic cells (DCs) expressing high CD11b (CD11b hi ) and intermediate CD11c (CD11c int ) arise in HR-sufficient but not HR-deficient mice. These DCs, which originate from the bone marrow are able to take up Ag from the peritoneum, traffic through the spleen and the lymph nodes and carry it to the thymus. In addition, since the DCs are able to present Ag to T cells, express high levels of the costimulatory molecule CD24, and comprise a CD8α + subset, it is likely that the cells contribute to T cell development and perhaps negative selection of self-reactive lymphocytes. Copyright © 2018 Elsevier Inc. All rights reserved.

Preparation of p-type NiO films by reactive sputtering and their application to CdTe solar cells

NASA Astrophysics Data System (ADS)

Ishikawa, Ryousuke; Furuya, Yasuaki; Araki, Ryouichi; Nomoto, Takahiro; Ogawa, Yohei; Hosono, Aikyo; Okamoto, Tamotsu; Tsuboi, Nozomu

2016-02-01

Transparent p-type NiO films were prepared by reactive sputtering using the facing-target system under Ar-diluted O2 gas at Tsub of 30 and 200 °C. The increasing intensity of dominant X-ray diffraction (XRD) peaks indicates improvements in the crystallinity of NiO films upon Cu doping. In spite of the crystallographic and optical changes after Cu-doping, the electrical properties of Cu-doped NiO films were slightly improved. Upon Ag-doping at 30 °C under low O2 concentration, on the other hand, the intensity of the dominant (111) XRD peaks was suppressed and p-type conductivity increased from ˜10-3 to ˜10-1 S cm-1. Finally, our Ag-doped NiO films were applied as the back contact of CdTe solar cells. CdTe solar cells with a glass/ITO/CdS/CdTe/NiO structure exhibited an efficiency of 6.4%, suggesting the high potential of using p-type NiO for the back-contact film in thin-film solar cells.

Persistence of Protective Immunity to Malaria Induced by DNA Priming and Poxvirus Boosting: Characterization of Effector and Memory CD8+-T-Cell Populations

PubMed Central

Sedegah, Martha; Brice, Gary T.; Rogers, William O.; Doolan, Denise L.; Charoenvit, Yupin; Jones, Trevor R.; Majam, Victoria F.; Belmonte, Arnel; Lu, Minh; Belmonte, Maria; Carucci, Daniel J.; Hoffman, Stephen L.

2002-01-01

The persistence of immunity to malaria induced in mice by a heterologous DNA priming and poxvirus boosting regimen was characterized. Mice were immunized by priming with DNA vaccine plasmids encoding the Plasmodium yoelii circumsporozoite protein (PyCSP) and murine granulocyte-macrophage colony-stimulating factor and boosting with recombinant vaccinia encoding PyCSP. BALB/c mice immunized with either high-dose (100 μg of p PyCSP plus 30 μg of pGM-CSF) or low-dose (1 μg of p PyCSP plus 1 μg of pGM-CSF DNA) priming were protected against challenge with 50 P. yoelii sporozoites. Protection 2 weeks after immunization was 70 to 100%, persisted at this level for at least 20 weeks, and declined to 30 to 40% by 28 weeks. Eight of eight mice protected at 20 weeks were still protected when rechallenged at 40 weeks. The antigen (Ag)-specific effector CD8+-T-cell population present 2 weeks after boosting had ex vivo Ag-specific cytolytic activity, expressed both gamma interferon (IFN-γ) and tumor necrosis factor alpha, and constituted 12 to 20% of splenic CD8+ T cells. In contrast, the memory CD8+-Ag-specific-cell population at 28 weeks lacked cytolytic activity and constituted only 6% of splenic CD8+ T cells, but at the single-cell level it produced significantly higher levels of IFN-γ than the effectors. High levels of Ag- or parasite-specific antibodies present 2 weeks after boosting had declined three- to sevenfold by 28 weeks. Low-dose priming was similarly immunogenic and as protective as high-dose priming against a 50-, but not a 250-, sporozoite challenge. These results demonstrate that a heterologous priming and boosting vaccination can provide lasting protection against malaria in this model system. PMID:12065488

Volatilization, transport and sublimation of metallic and non-metallic elements in high temperature gases at Merapi Volcano, Indonesia

USGS Publications Warehouse

Symonds, R.B.; Rose, William I.; Reed, M.H.; Lichte, F.E.; Finnegan, David L.

1987-01-01

Condensates, silica tube sublimates and incrustations were sampled from 500-800??C fumaroles and lava samples were collected at Merapi Volcano, Indonesia in Jan.-Feb., 1984. With respect to the magma, Merapi gases are enriched by factors greater than 105 in Se, Re, Bi and Cd; 104-105 in Au, Br, In, Pb and W; 103-104 in Mo, Cl, Cs, S, Sn and Ag; 102-103 in As, Zn, F and Rb; and 1-102 in Cu, K, Na, Sb, Ni, Ga, V, Fe, Mn and Li. The fumaroles are transporting more than 106 grams/day ( g d) of S, Cl and F; 104-106 g/d of Al, Br, Zn, Fe, K and Mg; 103-104 g d of Pb, As, Mo, Mn, V, W and Sr; and less than 103 g d of Ni, Cu, Cr, Ga, Sb, Bi, Cd, Li, Co and U. With decreasing temperature (800-500??C) there were five sublimate zones found in silica tubes: 1) cristobalite and magnetite (first deposition of Si, Fe and Al); 2) K-Ca sulfate, acmite, halite, sylvite and pyrite (maximum deposition of Cl, Na, K, Si, S, Fe, Mo, Br, Al, Rb, Cs, Mn, W, P, Ca, Re, Ag, Au and Co); 3) aphthitalite (K-Na sulfate), sphalerite, galena and Cs-K. sulfate (maximum deposition of Zn, Bi, Cd, Se and In; higher deposition of Pb and Sn); 4) Pb-K chloride and Na-K-Fe sulfate (maximum deposition of Pb, Sn and Cu); and 5) Zn, Cu and K-Pb sulfates (maximum deposition of Pb, Sn, Ti, As and Sb). The incrustations surrounding the fumaroles are also chemically zoned. Bi, Cd, Pb, W, Mo, Zn, Cu, K, Na, V, Fe and Mn are concentrated most in or very close to the vent as expected with cooling, atmospheric contamination and dispersion. The highly volatile elements Br, Cl, As and Sb are transported primarily away from high temperature vents. Ba, Si, P, Al, Ca and Cr are derived from wall rock reactions. Incomplete degassing of shallow magma at 915??C is the origin of most of the elements in the Merapi volcanic gas, although it is partly contaminated by particles or wall rock reactions. The metals are transported predominantly as chloride species. As the gas cools in the fumarolic environment, it becomes saturated with sublimate phases that fractionate from the gas in the order of their equilibrium saturation temperatures. Devolatilization of a cooling batholith could transport enough acids and metals to a hydrothermal system to play a significant role in forming an ore deposit. However, sublimation from a high temperature, high velocity carrier gas is not efficient enough to form a large ore deposit. Re, Se, Cd and Bi could be used as supporting evidence for magmatic fluid transport in an ore deposit. ?? 1987.

CD13 Autoantibodies Are Elevated in Sera From Mothers of Infants With Neonatal Cholestasis of Different Causes.

PubMed

Xu, Xinling; Rahbar, Afsar; Omarsdottir, Soley; Teng, Jonas; Németh, Antal; Fischler, Björn; Söderberg-Nauclér, Cecilia

2017-01-01

Human cytomegalovirus (HCMV) infection induces production of CD13-specific autoantibodies, which may promote inflammation and tissue damage. HCMV infection has been suggested as a cause of biliary atresia (BA), but little is known of its role in other forms of neonatal cholestasis. We studied serum levels of CD13-specific autoantibodies in mothers of infants with neonatal cholestasis of different causes, including BA, and in mothers of healthy, term infants without cholestasis, as well as in healthy blood donors. Using fluorescence-activated cell sorting, we measured CD13-specific autoantibody levels in serum from the above-mentioned groups. In addition, the effect of serum from mothers of infants with neonatal cholestasis was tested on the differentiation of monocytes into macrophages. CD13-specific autoantibodies were found in mothers of infants with neonatal cholestasis, but not in mothers of infants without cholestasis and healthy blood donors, and were associated with HCMV seropositivity. Sera from mothers of infants with all forms of neonatal cholestasis inhibited differentiation of monocytes into macrophages, but this was not dependent on CD13-specific autoantibodies. The significantly higher frequency of CD13-specific autoantibodies in mothers of infants with neonatal cholestasis of all forms compared with mothers of healthy infants without cholestasis suggests an association, but does not prove that they are pathogenic. The presence of CD13-specific autoantibodies does not correlate with HCMV IgG serostatus, suggesting a more complicated mechanism that possibly reflects active HCMV infection in these individuals. Further studies are needed to elucidate whether these autoantibodies contribute to the development of cholestasis or represent an epiphenomenon.

Origin discrimination of defatted pork via trace elements profiling, stable isotope ratios analysis, and multivariate statistical techniques.

PubMed

Park, Yu Min; Lee, Cheong Mi; Hong, Joon Ho; Jamila, Nargis; Khan, Naeem; Jung, Jong-Hyun; Jung, Young-Chul; Kim, Kyong Su

2018-09-01

This study verified the origin of 346 defatted Korean and non-Korean pork samples via trace elements profiling, and C and N stable isotope ratios analysis. The analyzed elements were 6 Li, 7 Li, 10 B, 11 B, 51 V , 50 Cr, 52 Cr, 53 Cr, 55 Mn, 58 Ni, 60 Ni, 59 Co, 63 Cu, 65 Cu, 64 Zn, 66 Zn, 69 Ga, 71 Ga, 75 As, 82 Se, 84 Sr, 86 Sr, 87 Sr, 88 Sr, 85 Rb, 94 Mo, 95 Mo, 97 Mo, 107 Ag, 109 Ag, 110 Cd, 111 Cd, 113 Cd, 112 Cd, 114 Cd, 116 Cd, 133 Cs, 206 Pb, 207 Pb, and 208 Pb. Content (mg/kg) of 51 V (0.012), 50 Cr (0.882), 75 As (0.017), 85 Rb (57.7), and 87 Sr (46.3) were high in Korean pork samples whereas 6 Li, 7 Li, 59 Co, 55 Mn, 58 Ni, 84 Sr, 86 Sr, 88 Sr, 111 Cd, and 133 Cs were found higher in non-Korean samples. The results of discriminant analysis showed that the trace elements content and stable isotope ratios were significant for the discrimination of geographical origins with a perfect discrimination rate of 100%. Copyright © 2018 Elsevier Ltd. All rights reserved.

[Therapeutic effect of autologous cytokine-induced killer cells on patients with liver cirrhosis caused by HBV infection].

PubMed

Su, Hai-bin; Li, Han-wei; Zhao, Hong-lan; Shi, Ming; Zhang, Bing; Tang, Zi-rong; Lei, Zhou-yun; Wang, Hui-fen; Wang, Fu-sheng

2007-03-01

To observe the therapeutic effect of autologous cytokine-induced killer cells (CIK) on HBV DNA positive patients with liver cirrhosis. HBV DNA positive 33 patients with cirrhosis were treated with CIK. Before and after cultured in vitro and post-treatment, CD3+, CD3+CD4+, CD3+CD8+, CD3+CD56+ cells, mDC and pDC were detected by flow cytometry. The indexes of virus and liver function were compared between pre- and post-treatment. CD3+, CD3+CD8+ cells and CD3+CD56+ cells were higher after cultured in vitro and after transfused back than those before culture (91.5 +/- 10.3, 74.4 +/- 9.9 vs. 67.9 +/- 12.8; 60.9 +/- 15.5, 37.3 +/- 15.1 vs. 27.9 +/- 10.9; 18.4 +/- 11.7, 14.5 +/- 7.5 vs. 10.6 +/- 7.1). The percentages of mDC and pDC also increased after-treatment vs. pre-treatment (0.54 +/- 0.18 vs. 0.70 +/- 0.29; 0.26 +/- 0.13 vs. 0.41 +/- 0.25). HBV DNA became undetectable in 12 patients and decrease exceeded 100 times in 4 patients after treatment. HBeAg became undetectable in 10 of 14 patients who were HBeAg positive pretreatment patients, among them 2 patients had HBeAb sero conversion. The liver function was improved after treatment. All patients tolerated the treatment. CIK treatment can increase immune effector cells and has some antiviral effect and is safe.

Thiopurines are negatively associated with anthropometric parameters in pediatric Crohn’s disease

PubMed Central

Gupta, Neera; Lustig, Robert H; Chao, Cewin; Vittinghoff, Eric; Andrews, Howard; Leu, Cheng-Shiun

2018-01-01

AIM To determine the distribution of anthropometric parameter (AP)-z-scores and characterize associations between medications/serum biomarkers and AP-z-scores in pediatric Crohn’s disease (CD). METHODS CD patients [< chronological age (CA) 21 years] were enrolled in a cross-sectional study. Descriptive statistics were generated for participants’ demographic characteristics and key variables of interest. Paired t-tests were used to compare AP-z-scores calculated based on CA (CA z-scores) and bone age (BA) (BA z-scores) for interpretation of AP’s. Linear regression was utilized to examine associations between medications and serum biomarkers with AP-z-scores calculated based on CA (n = 82) and BA (n = 49). We reported regression coefficients as well as their corresponding p-values and 95% confidence intervals. RESULTS Mean CA at the time of the study visit was 15.3 ± 3.5 (SD; range = 4.8-20.7) years. Mean triceps skinfold (P = 0.039), subscapular skinfold (P = 0.002) and mid-arm circumference (MAC) (P = 0.001) BA z-scores were higher than corresponding CA z-scores. Medications were positively associated with subscapular skinfold [adalimumab (P = 0.018) and methotrexate (P = 0.027)] and BMI CA z-scores [adalimumab (P = 0.029)]. Azathioprine/6-mercaptopurine were negatively associated with MAC (P = 0.045), subscapular skinfold (P = 0.014), weight (P = 0.002) and BMI (P = 0.013) CA z-scores. ESR, CRP, and WBC count were negatively associated, while albumin and IGF-1 BA z-scores were positively associated, with specific AP z-scores (P < 0.05). Mean height CA z-scores were higher in females, not males, treated with infliximab (P = 0.038). Hemoglobin (P = 0.018) was positively associated, while platelets (P = 0.005), ESR (P = 0.003) and CRP (P = 0.039) were negatively associated with height CA z-scores in males, not females. CONCLUSION Our results suggest poor efficacy of thiopurines and a possible sex difference in statural growth response to infliximab in pediatric CD. Prospective longitudinal studies are required. PMID:29760546

Enhanced photovoltaic performance of CdS-sensitized inverted organic solar cells prepared via a successive ionic layer adsorption and reaction method

NASA Astrophysics Data System (ADS)

Oleiwi, Hind Fadhil; Zakaria, Azmi; Yap, Chi Chin; Abbas, Haidr Abdulzahra; Tan, Sin Tee; Lee, Hock Beng; Tan, Chun Hui; Ginting, Riski Titian; Alshanableh, Abdelelah; Talib, Zainal Abidin

2017-05-01

One-dimensional ZnO nanorods (ZNRs) synthesized on fluorine-doped tin oxide (FTO) glass by hydrothermal method were modified with cadmium sulfide quantum dots (CdS QDs) as an electron transport layer (ETL) in order to enhance the photovoltaic performance of inverted organic solar cell (IOSC). In present study, CdS QDs were deposited on ZNRs using a Successive Ionic Layer Adsorption and Reaction method (SILAR) method. In typical procedures, IOSCs were fabricated by spin-coating the P3HT:PC61BM photoactive layer onto the as-prepared ZNRs/CdS QDs. The results of current-voltage (I-V) measurement under illumination shows that the FTO/ZNRs/CdS QDs/ P3HT:PC61BM/ PEDOT: PSS/Ag IOSC achieved a higher power conversion efficiency (4.06 %) in comparison to FTO/ZNRs/P3HT:PC61BM/PEDOT: PSS/Ag (3.6 %). Our findings suggest that the improved open circuit voltage (Voc) and short circuit current density (Jsc) of ZNRs/CdS QDs devices could be attributed to enhanced electron selectivity and reduced interfacial charge carrier recombination between ZNRs and P3HT:PC61BM after the deposition of CdS QDs. The CdS QDs sensitized ZNRs reported herein exhibit great potential for advanced optoelectronic application.

Self-assembly of high-nuclearity lanthanide-based nanoclusters for potential bioimaging applications

NASA Astrophysics Data System (ADS)

Yang, Xiaoping; Wang, Shiqing; Schipper, Desmond; Zhang, Lijie; Li, Zongping; Huang, Shaoming; Yuan, Daqiang; Chen, Zhongning; Gnanam, Annie J.; Hall, Justin W.; King, Tyler L.; Que, Emily; Dieye, Yakhya; Vadivelu, Jamuna; Brown, Katherine A.; Jones, Richard A.

2016-05-01

Two series of Cd-Ln and Ni-Ln clusters [Ln8Cd24L12(OAc)44(48)Cl4(0)] and [Ln8Ni6L6(OAc)24(EtOH)6(H2O)2] were constructed using a flexible ligand. The Cd-Ln clusters exhibit interesting nano-drum-like structures which allows direct visualization by TEM. Luminex MicroPlex Microspheres loaded with the Cd-Sm cluster were visualized using epifluorescence microscopy. Cytotoxicity studies on A549 and AGS cancer cell lines showed that the materials have mild to moderate cytotoxicity.Two series of Cd-Ln and Ni-Ln clusters [Ln8Cd24L12(OAc)44(48)Cl4(0)] and [Ln8Ni6L6(OAc)24(EtOH)6(H2O)2] were constructed using a flexible ligand. The Cd-Ln clusters exhibit interesting nano-drum-like structures which allows direct visualization by TEM. Luminex MicroPlex Microspheres loaded with the Cd-Sm cluster were visualized using epifluorescence microscopy. Cytotoxicity studies on A549 and AGS cancer cell lines showed that the materials have mild to moderate cytotoxicity. Electronic supplementary information (ESI) available: Full experimental and characterization details for 1-5. CCDC 1007468, 1007469 and 1007472-1007474. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c6nr00642f

Accumulation of Hg and other heavy metals in the Javan mongoose (Herpestes javanicus) captured on Amamioshima Island, Japan.

PubMed

Horai, Sawako; Minagawa, Mikiko; Ozaki, Hirokazu; Watanabe, Izumi; Takeda, Yasuo; Yamada, Katsushi; Ando, Tetsuo; Akiba, Suminori; Abe, Shintaro; Kuno, Katsuji

2006-10-01

Concentrations of 22 elements (Mg, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, Sb, Cs, Ba, Tl, total Hg (T-Hg), Pb) and organic Hg (O-Hg) were examined in the liver, kidney and brain of the Javan mongoose (Herpestes javanicus) and in liver of the Amami rabbit (Pentalagus furnessi) from Amamioshima Island in Japan. Relatively high levels of T-Hg levels (from 1.75 to 55.5 microg g-1 wet wt.) were found in the Javan mongoose. As for a comparison of hepatic T-Hg concentrations between the two areas, there was no significant difference between the Javan mongoose in Amamioshima and those in the Okinawa islands. In addition, T-Hg levels in the livers of the Amami rabbit were the same as in the livers of other herbivorous mammals. Taken together, it suggested that T-Hg accumulation in the livers of the Javan mongoose was not affected by the environment but by a specific physiological mechanism. The comparison of Hg and other heavy metal accumulations between terrestrial mammals (13 species, 61 individuals) including the Javan mongoose and marine mammals (18 species, 508 individuals) were also discussed.

Element contents in leaves of four plant species (birch, mountain ash, fern and spruce) along anthropogenic and geogenic concentration gradients.

PubMed

Reimann, Clemens; Arnoldussen, Arnold; Boyd, Rognvald; Finne, Tor Erik; Koller, Friedrich; Nordgulen, Øystein; Englmaier, Peter

2007-05-15

Forty samples each of leaves of birch (Betula pubescens Ehrh.), European mountain ash (Sorbus aucuparia (L.)) and bracken fern (Pteridium aquilinum (L.) Kuhn) as well as spruce needles (Picea abies (L.) Karsten) were collected along a 120 km south-north transect running through Norway's largest city, Oslo. Concentrations of 25 chemical elements (Ag, Au, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Sr, Ti, and Zn) as well as loss on ignition for the 4 sample materials are reported. The decline of input of sea spray with distance from the coast, geology, pH and anthropogenic contamination all played a role for the observed element concentrations in the leaves. Although growing under exactly the same natural conditions each plant species displayed quite unique uptake characteristics. Plant-species dependency and individual differences in the reaction of the plant leaves to different element sources make the investigated species of very limited value as bioindicators of anthropogenic activities. Anthropogenic contamination influences plant-leaf element content within a limited distance ( approximately 20 km) from the source.

Method of coating the interior surface of hollow objects with a diffusion coating

DOEpatents

Knowles, Shawn D.; Senor, David J.; Forbes, Steven V.; Johnson, Roger N.; Hollenberg, Glenn W.

2005-03-15

A method for forming a diffusion coating on the interior of surface of a hollow object wherein a filament, extending through a hollow object and adjacent to the interior surface of the object, is provided, with a coating material, in a vacuum. An electrical current is then applied to the filament to resistively heat the filament to a temperature sufficient to transfer the coating material from the filament to the interior surface of the object. The filament is electrically isolated from the object while the filament is being resistively heated. Preferably, the filament is provided as a tungsten filament or molybdenum filament. Preferably, the coating materials are selected from the group consisting of Ag, Al, As, Au, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Dy, Er, Eu, Fe, Ga, Ge, Hg, In, K, Li, Mg, Mn, Na, Ni P, Pb, Pd, Pr, S, Sb, Sc, Se, Si, Sn, Sr, Te, Tl, Y, Yb, Zn, and combinations thereof. The invention additionally allows for the formation of nitrides, hydrides, or carbides of all the possible coating materials, where such compounds exist, by providing a partial pressure of nitrogen, hydrogen, hydrocarbons, or combination thereof, within the vacuum.

Heavy metal and trace elements in riparian vegetation and macrophytes associated with lacustrine systems in Northern Patagonia Andean Range.

PubMed

Juárez, Andrea; Arribére, María A; Arcagni, Marina; Williams, Natalia; Rizzo, Andrea; Ribeiro Guevara, Sergio

2016-09-01

Vegetation associated with lacustrine systems in Northern Patagonia was studied for heavy metal and trace element contents, regarding their elemental contribution to these aquatic ecosystems. The research focused on native species and exotic vascular plant Salix spp. potential for absorbing heavy metals and trace elements. The native species studied were riparian Amomyrtus luma, Austrocedrus chilensis, Chusquea culeou, Desfontainia fulgens, Escallonia rubra, Gaultheria mucronata, Lomatia hirsuta, Luma apiculata, Maytenus boaria, Myrceugenia exsucca, Nothofagus antarctica, Nothofagus dombeyi, Schinus patagonicus, and Weinmannia trichosperma, and macrophytes Hydrocotyle chamaemorus, Isöetes chubutiana, Galium sp., Myriophyllum quitense, Nitella sp. (algae), Potamogeton linguatus, Ranunculus sp., and Schoenoplectus californicus. Fresh leaves were analyzed as well as leaves decomposing within the aquatic bodies, collected from lakes Futalaufquen and Rivadavia (Los Alerces National Park), and lakes Moreno and Nahuel Huapi (Nahuel Huapi National Park). The elements studied were heavy metals Ag, As, Cd, Hg, and U, major elements Ca, K, and Fe, and trace elements Ba, Br, Co, Cr, Cs, Hf, Na, Rb, Se, Sr, and Zn. Geochemical tracers La and Sm were also determined to evaluate contamination of the biological tissues by geological particulate (sediment, soil, dust) and to implement concentration corrections.

Significant increase in IgG4+ plasma cells in gastric biopsy specimens from patients with pernicious anaemia.

PubMed

Bedeir, Ahmed S; Lash, Richard H; Lash, Jonathan G; Ray, Mukunda B

2010-11-01

To investigate the presence of IgG4+ plasma cells in gastric mucosal biopsy samples from patients with atrophic gastritis (AG) and a history of pernicious anaemia (PA) (AG+PA+). Gastric mucosal biopsy specimens from 46 patients with AG+PA+ were investigated. As controls, we evaluated specimens from patients with AG but no history of PA (AG+ PA-) (n=25), normal histology (n=25), mild chronic inactive gastritis (MCIG) (n=25) or Helicobacter pylori gastritis (HP) (n=25). IgG4+ plasma cells were detected by two immunohistochemical methods: (1) using a monoclonal antibody, the average of the three most cellular high-power fields was counted in areas with the highest density of IgG4+ plasma cells; (2) using a dual-chromagen stain for both IgG4 and CD138 (plasma cell marker), the number of IgG4+ cells per 200 CD138+ plasma cells was counted. The latter was used to ensure that the number of IgG4+ cells was not simply related to the degree of inflammation (density of plasma cells). Identical results were obtained with the two staining methods. Increased numbers of IgG4+ plasma cells were present in 37% of patients with AG+PA+, but in none with AG+PA-, MCIG, HP or normal gastric biopsy results (100% specific, p=0.0001). IgG4+ plasma cells may play a role in the pathogenesis of PA and may be a useful marker for its diagnosis.

Baseline models of trace elements in major aquifers of the United States

USGS Publications Warehouse

Lee, L.; Helsel, D.

2005-01-01

Trace-element concentrations in baseline samples from a survey of aquifers used as potable-water supplies in the United States are summarized using methods appropriate for data with multiple detection limits. The resulting statistical distribution models are used to develop summary statistics and estimate probabilities of exceeding water-quality standards. The models are based on data from the major aquifer studies of the USGS National Water Quality Assessment (NAWQA) Program. These data were produced with a nationally-consistent sampling and analytical framework specifically designed to determine the quality of the most important potable groundwater resources during the years 1991-2001. The analytical data for all elements surveyed contain values that were below several detection limits. Such datasets are referred to as multiply-censored data. To address this issue, a robust semi-parametric statistical method called regression on order statistics (ROS) is employed. Utilizing the 90th-95th percentile as an arbitrary range for the upper limits of expected baseline concentrations, the models show that baseline concentrations of dissolved Ba and Zn are below 500 ??g/L. For the same percentile range, dissolved As, Cu and Mo concentrations are below 10 ??g/L, and dissolved Ag, Be, Cd, Co, Cr, Ni, Pb, Sb and Se are below 1-5 ??g/L. These models are also used to determine the probabilities that potable ground waters exceed drinking water standards. For dissolved Ba, Cr, Cu, Pb, Ni, Mo and Se, the likelihood of exceeding the US Environmental Protection Agency standards at the well-head is less than 1-1.5%. A notable exception is As, which has approximately a 7% chance of exceeding the maximum contaminant level (10 ??g/L) at the well head.

Chemical and physical properties of dry flue gas desulfurization products.

PubMed

Kost, David A; Bigham, Jerry M; Stehouwer, Richard C; Beeghly, Joel H; Fowler, Randy; Traina, Samuel J; Wolfe, William E; Dick, Warren A

2005-01-01

Beneficial and environmentally safe recycling of flue gas desulfurization (FGD) products requires detailed knowledge of their chemical and physical properties. We analyzed 59 dry FGD samples collected from 13 locations representing four major FGD scrubbing technologies. The chemistry of all samples was dominated by Ca, S, Al, Fe, and Si and strong preferential partitioning into the acid insoluble residue (i.e., coal ash residue) was observed for Al, Ba, Be, Cr, Fe, Li, K, Pb, Si, and V. Sulfur, Ca, and Mg occurred primarily in water- or acid-soluble forms associated with the sorbents or scrubber reaction products. Deionized water leachates (American Society for Testing and Materials [ASTM] method) and dilute acetic acid leachates (toxicity characteristic leaching procedure [TCLP] method) had mean pH values of >11.2 and high mean concentrations of S primarily as SO(2-)4 and Ca. Concentrations of Ag, As, Ba, Cd, Cr, Hg, Pb, and Se (except for ASTM Se in two samples) were below drinking water standards in both ASTM and TCLP leachates. Total toxicity equivalents (TEQ) of dioxins, for two FGD products used for mine reclamation, were 0.48 and 0.53 ng kg(-1). This was similar to the background level of the mine spoil (0.57 ng kg(-1)). The FGD materials were mostly uniform in particle size. Specific surface area (m2 g(-1)) was related to particle size and varied from 1.3 for bed ash to 9.5 for spray dryer material. Many of the chemical and physical properties of these FGD samples were associated with the quality of the coal rather than the combustion and SO2 scrubbing processes used.

Compositional analysis and pollution impact assessment: A case study in the Gulfs of Naples and Salerno

NASA Astrophysics Data System (ADS)

Menghan, Wang; Stefano, Albanese; Annamaria, Lima; Claudia, Cannatelli; Antonio, Cosenza; Wanjun, Lu; Marco, Sacchi; Angela, Doherty; Benedetto, De Vivo

2015-07-01

This paper presents the results of an environmental geochemical investigation of the Gulfs of Naples and Salerno, near the Campania plain (Southern Italy). Surface marine sediment samples were collected during three field campaigns: 96 from the Gulfs of Naples and Salerno (NaSa); 123 from the Bagnoli site coastal area (BaSi); and 11 from the ports around the Gulf of Naples (PoNa). Elemental concentrations were determined and their interpolated distribution maps were compiled. Three geochemical sources (or processes) were determined associating elemental distribution with the results obtained from a R-mode factor analysis: 1) geogenic, 2) water kinetics and 3) anthropogenic. The results are presented as raw data single element distributions of eight potential toxic elements (PTEs) (As, Cd, Cr, Cu, Hg, Pb, Ni and Zn) in the forms of raw data and additive log-ratio transformed data. The latter showed advantages in revealing the actual distribution patterns. Geochemical background reference values of PTEs were determined from the median value of local background reference values. Based on these values, pollution impact analysis was carried out to both BaSi and PoNa samples, indicating most of BaSi and PoNa sediments were affected by moderate to strong Pb, Zn, Cd and Hg pollution. An ecological risk assessment was subsequently carried out on the entire database, pointing a toxic risk ranking in the order Pb > As > Ni > Cd > Hg > Cr.

Effect of dipolar fields, surface termination, and surface orientation on photochemical reactions on transition metal oxides

NASA Astrophysics Data System (ADS)

Giocondi, Jennifer Lynn

Experiments have been conducted to determine the effects of dipolar fields, surface termination, and surface orientation on the photochemical reactivity of several transition metal oxides. These compounds include BaTiO3, SrTiO3, BaTi4O9, Sr2Nb2O 7, and Sr2Ta2O7 which were studied as polycrystalline ceramics, single crystals, micron-sized faceted particles, or some combination of these forms. The reduction of Ag+ from an aqueous AgNO3 solution (Ag0 product) and the oxidation of Pb2+ from an aqueous lead acetate solution (PbO 2 product) were selected as probe reactions because they leave insoluble products on the oxide surfaces. The reactivity of ferroelectric BaTiO3 was dominated by the effect of dipolar fields on the transport of photogenerated charge carriers. Silver was reduced on domains with a positive surface charge while lead was oxidized on domains with a negative surface charge. This reactivity implies that the dipolar field in individual domains drives photogenerated charge carriers to oppositely charged surfaces. This reaction mechanism results in a physical separation of the photogenerated charge carriers and the locations of the oxidation and reduction half reactions on the catalyst surface. Experiments performed on polycrystalline ceramics, single crystals, and micron-sized particles all showed this domain specific reactivity. SrTiO3 has the ideal cubic perovskite structure from which the tetragonally distorted ferroelectric BaTiO3 phase is derived. Polished and annealed surfaces of randomly oriented grain surfaces were bound by some combination of the following three planes: {110}, {111}, and a complex facet inclined approximately 24° from {100}. Surfaces with the complex {100} facet were found to be the most active for Ag reduction. Single crystal studies also showed that the nonpolar (100) surface is the most reactive and that the composition of the termination layer does not influence this reaction. However, the polar (111) and (110) surfaces had a non-uniform distribution of reaction products. For these orientations, the location of the reduction and oxidation reactions is determined by the chemical and charge terminations of the different terraces or facets. The reactivity for silver reduction on the faceted particles is ranked as (100) > (111) > (110) while the (100) surface was least reactive for lead oxidation. Overall, these results show that the photochemical reactivity of SrTiO3 is anisotropic and that on polar surfaces, dipolar fields arising from charged surface domains influence the transport of photogenerated charge carriers and promote spatially selective oxidation and reduction reactions. (Abstract shortened by UMI.)

Hydroxypropyl-β-Cyclodextrin Spikes Local Inflammation That Induces Th2 Cell and T Follicular Helper Cell Responses to the Coadministered Antigen

PubMed Central

Onishi, Motoyasu; Ozasa, Koji; Kobiyama, Kouji; Ohata, Keiichi; Kitano, Mitsutaka; Taniguchi, Keiichi; Homma, Tomoyuki; Kobayashi, Masanori; Sato, Akihiko; Katakai, Yuko; Yasutomi, Yasuhiro; Wijaya, Edward; Igarashi, Yoshinobu; Nakatsu, Noriyuki; Ise, Wataru; Inoue, Takeshi; Yamada, Hiroshi; Vandenbon, Alexis; Standley, Daron M.; Kurosaki, Tomohiro; Coban, Cevayir; Aoshi, Taiki; Kuroda, Etsushi

2015-01-01

Cyclodextrins are commonly used as a safe excipient to enhance the solubility and bioavailability of hydrophobic pharmaceutical agents. Their efficacies and mechanisms as drug-delivery systems have been investigated for decades, but their immunological properties have not been examined. In this study, we reprofiled hydroxypropyl-β-cyclodextrin (HP-β-CD) as a vaccine adjuvant and found that it acts as a potent and unique adjuvant. HP-β-CD triggered the innate immune response at the injection site, was trapped by MARCO+ macrophages, increased Ag uptake by dendritic cells, and facilitated the generation of T follicular helper cells in the draining lymph nodes. It significantly enhanced Ag-specific Th2 and IgG Ab responses as potently as did the conventional adjuvant, aluminum salt (alum), whereas its ability to induce Ag-specific IgE was less than that of alum. At the injection site, HP-β-CD induced the temporary release of host dsDNA, a damage-associated molecular pattern. DNase-treated mice, MyD88-deficient mice, and TBK1-deficient mice showed significantly reduced Ab responses after immunization with this adjuvant. Finally, we demonstrated that HP-β-CD–adjuvanted influenza hemagglutinin split vaccine protected against a lethal challenge with a clinically isolated pandemic H1N1 influenza virus, and the adjuvant effect of HP-β-CD was demonstrated in cynomolgus macaques. Our results suggest that HP-β-CD acts as a potent MyD88- and TBK1-dependent T follicular helper cell adjuvant and is readily applicable to various vaccines. PMID:25681338

CD22 and Siglec-G in B cell function and tolerance.

PubMed

Poe, Jonathan C; Tedder, Thomas F

2012-08-01

The immune system has evolved into two main arms: the primitive innate arm that is the first line of defense but relatively short-lived and broad acting; and the advanced adaptive arm that generates immunological memory, allowing rapid, specific recall responses. T cell-independent type-2 (TI-2) antigens (Ags) invoke innate immune responses. However, due to its 'at the ready' nature, how the innate arm of the immune system maintains tolerance to potentially abundant host TI-2 Ags remains elusive. Therefore, it is important to define the mechanisms that establish innate immune tolerance. This review highlights recent insights into B cell tolerance to theoretical self TI-2 Ags, and examines how the B cell-restricted sialic acid binding Ig-like lectins (Siglecs), CD22 and Siglec-G, might contribute to this process. Copyright © 2012 Elsevier Ltd. All rights reserved.

AgI -Induced Switching of DNA Binding Modes via Formation of a Supramolecular Metallacycle.

PubMed

Basak, Shibaji; Léon, J Christian; Ferranco, Annaleizle; Sharma, Renu; Hebenbrock, Marian; Lough, Alan; Müller, Jens; Kraatz, Heinz-Bernhard

2018-03-12

The histidine derivative L1 of the DNA intercalator naphthalenediimide (NDI) forms a triangular Ag I complex (C2). The interactions of L1 and of C2 with DNA were studied by circular dichroism (CD) and UV/Vis spectroscopy and by viscosity studies. Different binding modes were observed for L1 and for C2, as the Ag I complex C2 is too large in size to act as an intercalator. If Ag I is added to the NDI molecule that is already intercalated into a duplex, higher order complexes are formed within the DNA duplex and cause disruptions in the helical duplex structure, which leads to a significant decrease in the characteristic CD features of B-DNA. Thus, via addition of a metal we show how a classic and well-known organic intercalator unit can be turned into a partial metallo insertor. We also show how electrochemical impedance spectroscopy (EIS) can be used to probe DNA binding modes on DNA films that are immobilized on gold surfaces. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

EndoU is a novel regulator of AICD during peripheral B cell selection

PubMed Central

Poe, Jonathan C.; Kountikov, Evgueni I.; Lykken, Jacquelyn M.; Natarajan, Abirami; Marchuk, Douglas A.

2014-01-01

Balanced transmembrane signals maintain a competent peripheral B cell pool limited in self-reactive B cells that may produce pathogenic autoantibodies. To identify molecules regulating peripheral B cell survival and tolerance to self-antigens (Ags), a gene modifier screen was performed with B cells from CD22-deficient C57BL/6 (CD22−/−[B6]) mice that undergo activation-induced cell death (AICD) and fail to up-regulate c-Myc expression after B cell Ag receptor ligation. Likewise, lysozyme auto-Ag–specific B cells in IgTg hen egg lysozyme (HEL) transgenic mice inhabit the spleen but undergo AICD after auto-Ag encounter. This gene modifier screen identified EndoU, a single-stranded RNA-binding protein of ancient origin, as a major regulator of B cell survival in both models. EndoU gene disruption prevents AICD and normalizes c-Myc expression. These findings reveal that EndoU is a critical regulator of an unexpected and novel RNA-dependent pathway controlling peripheral B cell survival and Ag responsiveness that may contribute to peripheral B cell tolerance. PMID:24344237

Pathogen Proliferation Governs the Magnitude but Compromises the Function of CD8 T Cells1

PubMed Central

Sad, Subash; Dudani, Renu; Gurnani, Komal; Russell, Marsha; van Faassen, Henk; Finlay, Brett; Krishnan, Lakshmi

2014-01-01

CD8+ T cell memory is critical for protection against many intracellular pathogens. However, it is not clear how pathogen virulence influences the development and function of CD8+ T cells. Salmonella typhimurium (ST) is an intracellular bacterium that causes rapid fatality in susceptible mice and chronic infection in resistant strains. We have constructed recombinant mutants of ST, expressing the same immunodominant Ag OVA, but defective in various key virulence genes. We show that the magnitude of CD8+ T cell response correlates directly to the intracellular proliferation of ST. Wild-type ST displayed efficient intracellular proliferation and induced increased numbers of OVA-specific CD8+ T cells upon infection in mice. In contrast, mutants with defective Salmonella pathogenicity island II genes displayed poor intracellular proliferation and induced reduced numbers of OVA-specific CD8+ T cells. However, when functionality of the CD8+ T cell response was measured, mutants of ST induced a more functional response compared with the wild-type ST. Infection with wild-type ST, in contrast to mutants defective in pathogenicity island II genes, induced the generation of mainly effector-memory CD8+ T cells that expressed little IL-2, failed to mediate efficient cytotoxicity, and proliferated poorly in response to Ag challenge in vivo. Taken together, these results indicate that pathogens that proliferate rapidly and chronically in vivo may evoke functionally inferior memory CD8+ T cells which may promote the survival of the pathogen. PMID:18424704

Selective CD28 Antagonist Blunts Memory Immune Responses and Promotes Long-Term Control of Skin Inflammation in Nonhuman Primates.

PubMed

Poirier, Nicolas; Chevalier, Melanie; Mary, Caroline; Hervouet, Jeremy; Minault, David; Baker, Paul; Ville, Simon; Le Bas-Bernardet, Stephanie; Dilek, Nahzli; Belarif, Lyssia; Cassagnau, Elisabeth; Scobie, Linda; Blancho, Gilles; Vanhove, Bernard

2016-01-01

Novel therapies that specifically target activation and expansion of pathogenic immune cell subsets responsible for autoimmune attacks are needed to confer long-term remission. Pathogenic cells in autoimmunity include memory T lymphocytes that are long-lived and present rapid recall effector functions with reduced activation requirements. Whereas the CD28 costimulation pathway predominantly controls priming of naive T cells and hence generation of adaptive memory cells, the roles of CD28 costimulation on established memory T lymphocytes and the recall of memory responses remain controversial. In contrast to CD80/86 antagonists (CTLA4-Ig), selective CD28 antagonists blunt T cell costimulation while sparing CTLA-4 and PD-L1-dependent coinhibitory signals. Using a new selective CD28 antagonist, we showed that Ag-specific reactivation of human memory T lymphocytes was prevented. Selective CD28 blockade controlled both cellular and humoral memory recall in nonhuman primates and induced long-term Ag-specific unresponsiveness in a memory T cell-mediated inflammatory skin model. No modification of memory T lymphocytes subsets or numbers was observed in the periphery, and importantly no significant reactivation of quiescent viruses was noticed. These findings indicate that pathogenic memory T cell responses are controlled by both CD28 and CTLA-4/PD-L1 cosignals in vivo and that selectively targeting CD28 would help to promote remission of autoimmune diseases and control chronic inflammation. Copyright © 2015 by The American Association of Immunologists, Inc.

Distinct neural mechanisms for reading Arabic vs verbal numbers: an ERP study.

PubMed

Proverbio, Alice Mado; Bianco, Marco; de Benedetto, Francesco

2018-05-12

In this EEG/ERP study, 16 volunteers were asked to compare the numerical equality of 360 pairs of multi-digit numbers presented in Arabic or verbal format. Behavioural data showed faster and more accurate responses for digit targets, with a right hand/left hemisphere advantage only for verbal numerals. Occipito-temporal N1, peaking at approximately 180 ms, was strongly left-lateralized during verbal number processing and bilateral during digit processing. A LORETA (low resolution electromagnetic tomography) source reconstruction performed at the N1 latency stage (155-185 ms) revealed greater brain activation during coding of Arabic than of verbal stimuli. Digit perceptual coding was associated with the activation of the right angular gyrus (rAG), the left fusiform gyrus (FG, BA37), and left and right superior and medial frontal areas. N1 sources for verbal numerals included the left FG (BA37), the precuneus (BA31), the parahippocampal area and a small right prefrontal activation. In addition, verbal numerals elicited a late frontocentral negativity, possibly reflecting stimulus unfamiliarity or complexity. Overall, the data suggest distinct mechanisms for number reading through ciphers (digits) or words. Information about quantity was accessed earlier and more accurately if numbers were in a nonlinguistic code. Indeed, it can be speculated that numerosity processing would involve circuits originally involved in processing space (i.e.,rAG/rIPS). This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Heavy metals in waters and suspended sediments affected by a mine tailing spill in the upper San Lorenzo River, Northwestern México.

PubMed

Páez-Osuna, F; Bojórquez-Leyva, H; Bergés-Tiznado, M; Rubio-Hernández, O A; Fierro-Sañudo, J F; Ramírez-Rochín, J; León-Cañedo, J A

2015-05-01

Concentrations of arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), mercury (Hg), silver (Ag) and zinc (Zn) were evaluated in water and suspended sediments of the upper waters of San Lorenzo River in NW Mexico following a mine tailing spill. Except As (6.64-35.9 µg L(-1)), dissolved metal concentrations were low (Ag <0.06-0.22; Cd 0.01-0.34; Cu 4.71-10.2; Hg 0.02-0.24; Pb <0.15-0.65; Zn 86-1,080 µg L(-1)) and were less than the upper limits established by UNEP (Water quality for ecosystem and human health, 2nd edn. United Nations Environment Programme Global Environment Monitoring System/Water Programme, Burlington, 2008), EPA (2014) and the Mexican regulation (NOM 1994). In contrast, the suspended metal concentrations were high (As 91.4-130; Ag 22.1-531; Cd 3.14-6.30; Cu 65-123; Hg 0.47-1.09; Pb 260-818; Zn 742-1,810 mg kg(-1)) and most of samples exceeded the probable effect level of the Canadian Sediment Quality Guidelines for the Protection of Aquatic Life.

Monoclinic β-BaY2F8—a novel crystal simultaneously active for SRS and Ln3+-ion lasing

NASA Astrophysics Data System (ADS)

Kaminskii, A. A.; Lux, O.; Hanuza, J.; Rhee, H.; Eichler, H. J.; Zhang, J.; Tang, D.; Shen, D.; Yu, H.; Wang, J.; Yoneda, H.; Shirakawa, A.

2015-01-01

This paper presents the first investigation of stimulated Raman scattering (SRS) in the monoclinic fluoride crystal β-BaY2F8, which is known as a promising host-material for trivalent lanthanide (Ln3+) lasant ions. Picosecond laser excitation in the visible and near-IR spectral range at room temperature revealed the manifestation of nine SRS-promoting phonon modes, which are related to Ag and Bg vibrations of the crystal. Besides multi-phonon Stokes and anti-Stokes generation, we observed cross-cascaded χ(3) ↔ χ(3) processes involving different pairs of SRS-active phonons. A comparative estimation of the first Stokes steady-state Raman gain coefficients, both in the visible and near-IR region related to the most active SRS-phonon mode ωSRS1 ≈ 208 cm-1 of β-BaY2F8, was also performed. Furthermore, a brief review of the pioneering papers on laser action of Ln3+-ions doped in β-BaY2F8 single crystals and other known SRS-active fluoride crystals is given in tabular form.

Sequence variations and two levels of MCT1 and CD147 expression in red blood cells and gluteus muscle of horses.

PubMed

Koho, N M; Mykkänen, A K; Reeben, M; Raekallio, M R; Ilves, M; Pösö, A R

2012-01-01

MCT1-CD147 complex is the prime lactate transporter in mammalian plasma membranes. In equine red blood cells (RBCs), activity of the complex and expression of MCT1 and CD147 is bimodal; high in 70% and low in 30%. We studied whether sequence variations contribute to the bimodal expression of MCT1 and CD147. Samples of blood and cremaster muscle were collected in connection of castration from 24 horses. Additional gluteus muscle samples were collected from 15 Standardbreds of which seven were known to express low amounts of CD147 in RBCs. The cDNA of MCT1 and CD147 together with a promoter region of CD147 was sequenced. The amounts of MCT1 and CD147 expressed in RBC and muscle membranes were measured by Western blot and mRNA levels in muscles by qPCR. MCT1 and CD147 were expressed in 20 castrates, and in four only were traces found. Sequence variations found in MCT1 were not linked to MCT1 expression. In CD147 linked heterozygous single nucleotide polymorphisms (SNPs) 389A>G (Met(125)Val) and 990C>T (3'-UTR) were associated to low expression of CD147. Also a mutation 168A>G (Ile(51)Val) in CD147 was associated to low MCT1 and CD147 expression. Low MCT1 and CD147 mRNA levels in gluteus were found in Standardbreds with low CD147 expression in RBCs. The results suggest that sequence variations affect the expression level of CD147, but do not explain its bimodality. The levels of MCT1 and CD147 mRNA correlated with the expression of CD147 and suggest that bimodality of their expression is regulated at transcriptional level. Copyright © 2011 Elsevier B.V. All rights reserved.

Processing and nanostructure influences on mechanical properties of thermoelectric materials

NASA Astrophysics Data System (ADS)

Schmidt, Robert David

Thermoelectric (TE) materials are materials that can generate an electric current from a thermal gradient, with possible service in recovery of waste heat such as engine exhaust. Significant progress has been made in improving TE conversion efficiency, typically reported according to the figure of merit, ZT, with several recent papers publishing ZT values above 2. Furthermore, cost reductions may be made by the use of lower cost elements such as Mg, Si, Sn, Pb, Se and S in TE materials, while achieving ZT values between 1.3 and 1.8. To be used in a device, the thermoelectric material must be able to withstand the applied thermal and mechanical forces without failure. However, these materials are brittle, with low fracture toughness typically less than 1.5 MPa-m1/2, and often less than 0.5 MPa-m1/2. For comparison, window glass is approximately 0.75 MPa-m1/2. They have been optimized with nanoprecipitates, nanoparticles, doping, alterations in stoichiometry, powder processing and other techniques, all of which may alter the mechanical properties. In this study, the effect of SiC nanoparticle additions in Mg2Si, SnTe and Ag nanoparticle additions in the skutterudite Ba0.3Co 4Sb12 on the elastic moduli, hardness and fracture toughness are measured. Large changes (˜20%) in the elastic moduli in SnTe 1+x as a function of x at 0 and 0.016 are shown. The effect on mechanical properties of doping and precipitates of CdS or ZnS in a PbS or PbSe matrix have been reported. Changes in sintering behavior of the skutterudite with the Ag nanoparticle additions were explored. Possible liquid phase sintering, with associated benefits in lower processing temperature, faster densification and lower cost, has been shown. A technique has been proposed for determining additional liquid phase sintering aids in other TE materials. The effects of porosity, grain size, powder processing method, and sintering method were explored with YbAl3 and Ba0.3Co4Sb 12, with the porosity dependence of the elastic moduli reported. Only one other TE material has the porosity dependence of the elastic moduli previously reported in the literature, lead-antimony-silver-tellurium (LAST), and the effect of different powder processing and sintering methods has never been reported previously on TE materials.

Geochemical gradients in soil O-horizon samples from southern Norway: Natural or anthropogenic?

USGS Publications Warehouse

Reimann, C.; Englmaier, P.; Flem, B.; Gough, L.; Lamothe, P.; Nordgulen, O.; Smith, D.

2009-01-01

Forty soil O- and C-horizon samples were collected along a south-to-north transect extending inland for approximately 200 km from the southern tip of Norway. The elements As, Au, Bi, Cd, Cu, Ga, Ge, Hf, Hg, In, Mg, Mn, Mo, Na, Ni, Pb, Sb, Se, V, W, Zn and Zr all show a distinct decrease in concentration in soil O-horizons with increasing distance from the coast. The elements showing the strongest coastal enrichment, some by more than an order of magnitude compared to inland samples, are Au, Bi, As, Pb, Sb and Sn. Furthermore, the elements Cd (median O-/median C-horizon = 31), C, Sb, Ag, K, S, Ge (10), Hg, Pb, As, Bi, Sr (5), Se, Au, Ba, Na, Zn, P, Cu and Sn (2) are all strongly enriched in the O-horizon when compared to the underlying C-horizon. Lead isotope ratios, however, do not show any gradient with distance from the coast (declining Pb concentration). Along a 50 km topographically steep east-west transect in the centre of the survey area, far from the coast but crossing several vegetation zones, similar element enrichment patterns and concentration gradients can be observed in the O-horizon. Lead isotope ratios in the O-horizon correlate along both transects with pH and the C/N-ratio, both proxies for the quality of the organic material. Natural conditions in southern Norway, related to climate and vegetation, rather than long range atmospheric transport of air pollutants (LRT), cause the observed features. ?? 2008 Elsevier Ltd.

Concretionary manganese-iron oxides in streams and their usefulness as a sample medium for geochemical prospecting

USGS Publications Warehouse

Nowlan, G.A.

1976-01-01

Correlation studies of 400 samples of sieved stream sediments and 325 samples of fluvial, concretionary Mn-Fe oxides from Maine resulted in the separation of elements into the following categories: (1) elements not scavenged by Mn-Fe oxides - B, Cr, K, Mg, Rb, Sc, Ti, V, and Zr; (2) elements probably not scavenged by Mn-Fe oxides - Ag, Be, Ca, Ga, La, Sb, and Y; (3) elements scavenged weakly by Mn-Fe oxides - Cu, Mo, Pb, and Sr; (4) elements scavenged strongly by Mn oxides - Ba, Cd, Co, Ni, Tl, and Zn; and (5) elements scavenged strongly by Fe oxides - As and In. Studies of the scavenged elements showed that the deviation from the mean is characteristically greater in oxide samples as compared to sieved sediments from the same locality. However, a significant increase in contrast between anomalous and background localities, when oxides are the sample medium, more than offsets the disadvantage of data scatter. The use of oxides as a sampling medium clearly and significantly accentuates anomalous localities. In general, non-ratioed data on oxides give very nearly the same results as data consisting of scavenged elements ratioed to Mn and Fe. However, ratioed data expand the geographic area of specific anomalies. Cd and Zn consistently show strong correlations with concretionary Mn-Fe oxides, but their concentrations in the oxides do not generally show as much contrast between anomalous and background localities as do Cu, Mo, and Pb. These latter elements are strongly scavenged where rocks are mineralized. ?? 1976.

Metal and hydrocarbon behavior in sediments from Brazilian shallow waters drilling activities using nonaqueous drilling fluids (NAFs).

PubMed

do Carmo R Peralba, Maria; Pozebon, Dirce; dos Santos, João H Z; Maia, Sandra M; Pizzolato, Tânia M; Cioccari, Giovani; Barrionuevo, Simone

2010-08-01

The impact of drilling oil activities in the Brazilian Bonito Field/Campos Basin (Rio de Janeiro) shell drilling (300 m) using nonaqueous fluids (NAFs) was investigated with respect to Al, Fe, Mn, Ba, Co, Pb, Cu, As, Hg, Cr, Ni, Zn, Cd, V, and aliphatic and polynuclear aromatic hydrocarbons concentrations in the sediment. Sampling took place in three different times during approximately 33 months. For the metals Al, As, Co, Cr, Cu, Cd, Fe, Ni, Mn, V, and Zn, no significant variation was observed after drilling activities in most of the stations. However, an increase was found in Ba concentration--due to the drilling activity--without return to the levels found 22 months after drilling. High Ba contents was already detected prior to well drilling, probably due to drilling activities in other wells nearby. Hydrocarbon contents also suggest previous anthropogenic activities. Aliphatic hydrocarbon contents were in the range usually reported in other drilling sites. The same behavior was observed in the case of polyaromatic hydrocarbons. Nevertheless, the n-alkane concentration increased sharply after drilling, returning almost to predrilling levels 22 months after drilling activities.

Dependences of the density of M 1- x R x F2 + x and R 1- y M y F3- y single crystals ( M = Ca, Sr, Ba, Cd, Pb; R means rare earth elements) on composition

NASA Astrophysics Data System (ADS)

Sorokin, N. I.; Krivandina, E. A.; Zhmurova, Z. I.

2013-11-01

The density of single crystals of nonstoichiometric phases Ba1 - x La x F2 + x (0 ≤ x ≤ 0.5) and Sr0.8La0.2 - x Lu x F2.2 (0 ≤ x ≤ 0.2) with the fluorite (CaF2) structure type and R 1 - y Sr y F3 - y ( R = Pr, Nd; 0 ≤ y ≤ 0.15) with the tysonite (LaF3) structure type has been measured. Single crystals were grown from a melt by the Bridgman method. The measured concentration dependences of single crystal density are linear. The interstitial and vacancy models of defect formation in the fluorite and tysonite phases, respectively, are confirmed. To implement the composition control of single crystals of superionic conductors M 1 - x R x F2 + x and R 1 - y M y F3 - y in practice, calibration graphs of X-ray density in the MF2- RF3 systems ( M = Ca, Sr, Ba, Cd, Pb; R = La-Lu, Y) are plotted.

An inducible transgenic mouse breast cancer model for the analysis of tumor antigen specific CD8+ T-cell responses

PubMed Central

Bruns, Michael; Wanger, Jara; Utermöhlen, Olaf; Deppert, Wolfgang

2015-01-01

In Simian virus 40 (SV40) transgenic BALB/c WAP-T mice tumor development and progression is driven by SV40 tumor antigens encoded by inducible transgenes. WAP-T mice constitute a well characterized mouse model for breast cancer with strong similarities to the corresponding human disease. BALB/c mice mount only a weak cellular immune response against SV40 T-antigen (T-Ag). For studying tumor antigen specific CD8+ T-cell responses against transgene expressing cells, we created WAP-TNP mice, in which the transgene additionally codes for the NP118–126-epitope contained within the nucleoprotein of lymphocytic choriomeningitis virus (LCMV), the immune-dominant T-cell epitope in BALB/c mice. We then investigated in WAP-TNP mice the immune responses against SV40 tumor antigens and the NP-epitope within the chimeric T-Ag/NP protein (T-AgNP). Analysis of the immune-reactivity against T-Ag in WAP-T and of T-AgNP in WAP-TNP mice revealed that, in contrast to wild type (wt) BALB/c mice, WAP-T and WAP-TNP mice were non-reactive against T-Ag. However, like wtBALB/c mice, WAP-T as well as WAP-TNP mice were highly reactive against the immune-dominant LCMV NP-epitope, thereby allowing the analysis of NP-epitope specific cellular immune responses in WAP-TNP mice. LCMV infection of WAP-TNP mice induced a strong, LCMV NP-epitope specific CD8+ T-cell response, which was able to specifically eliminate T-AgNP expressing mammary epithelial cells both prior to tumor formation (i.e. in cells of lactating mammary glands), as well as in invasive tumors. Elimination of tumor cells, however, was only transient, even after repeated LCMV infections. Further studies showed that already non-infected WAP-TNP tumor mice contained LCMV NP-epitope specific CD8+ T-cells, albeit with strongly reduced, though measurable activity. Functional impairment of these ‘endogenous’ NP-epitope specific T-cells seems to be caused by expression of the programmed death-1 protein (PD1), as anti-PD1 treatment of splenocytes from WAP-TNP tumor mice restored their activity. These characteristics are similar to those found in many tumor patients and render WAP-TNP mice a suitable model for analyzing parameters to overcome the blockade of immune checkpoints in tumor patients. PMID:26513294

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2010-08-18

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Increased numbers of preexisting memory CD8 T cells and decreased T-bet expression can restrain terminal differentiation of secondary effector and memory CD8 T cells.

PubMed

Joshi, Nikhil S; Cui, Weiguo; Dominguez, Claudia X; Chen, Jonathan H; Hand, Timothy W; Kaech, Susan M

2011-10-15

Memory CD8 T cells acquire effector memory cell properties after reinfection and may reach terminally differentiated, senescent states ("Hayflick limit") after multiple infections. The signals controlling this process are not well understood, but we found that the degree of secondary effector and memory CD8 T cell differentiation was intimately linked to the amount of T-bet expressed upon reactivation and preexisting memory CD8 T cell number (i.e., primary memory CD8 T cell precursor frequency) present during secondary infection. Compared with naive cells, memory CD8 T cells were predisposed toward terminal effector (TE) cell differentiation because they could immediately respond to IL-12 and induce T-bet, even in the absence of Ag. TE cell formation after secondary (2°) or tertiary infections was dependent on increased T-bet expression because T-bet(+/-) cells were resistant to these phenotypic changes. Larger numbers of preexisting memory CD8 T cells limited the duration of 2° infection and the amount of IL-12 produced, and consequently, this reduced T-bet expression and the proportion of 2° TE CD8 T cells that formed. Together, these data show that over repeated infections, memory CD8 T cell quality and proliferative fitness is not strictly determined by the number of serial encounters with Ag or cell divisions, but is a function of the CD8 T cell differentiation state, which is genetically controlled in a T-bet-dependent manner. This differentiation state can be modulated by preexisting memory CD8 T cell number and the intensity of inflammation during reinfection. These results have important implications for vaccinations involving prime-boost strategies.

CD36 Modulates Fasting and Preabsorptive Hormone and Bile Acid Levels.

PubMed

Shibao, Cyndya A; Celedonio, Jorge E; Tamboli, Robyn; Sidani, Reem; Love-Gregory, Latisha; Pietka, Terri; Xiong, Yanhua; Wei, Yan; Abumrad, Naji N; Abumrad, Nada A; Flynn, Charles Robb

2018-05-01

Abnormal fatty acid (FA) metabolism contributes to diabetes and cardiovascular disease. The FA receptor CD36 has been linked to risk of metabolic syndrome. In rodents CD36 regulates various aspects of fat metabolism, but whether it has similar actions in humans is unknown. We examined the impact of a coding single-nucleotide polymorphism in CD36 on postprandial hormone and bile acid (BA) responses. To examine whether the minor allele (G) of coding CD36 variant rs3211938 (G/T), which reduces CD36 level by ∼50%, influences hormonal responses to a high-fat meal (HFM). Obese African American (AA) women carriers of the G allele of rs3211938 (G/T) and weight-matched noncarriers (T/T) were studied before and after a HFM. Two-center study. Obese AA women. HFM. Early preabsorptive responses (10 minutes) and extended excursions in plasma hormones [C-peptide, insulin, incretins, ghrelin fibroblast growth factor (FGF)19, FGF21], BAs, and serum lipoproteins (chylomicrons, very-low-density lipoprotein) were determined. At fasting, G-allele carriers had significantly reduced cholesterol and glycodeoxycholic acid and consistent but nonsignificant reductions of serum lipoproteins. Levels of GLP-1 and pancreatic polypeptide (PP) were reduced 60% to 70% and those of total BAs were 1.8-fold higher. After the meal, G-allele carriers displayed attenuated early (-10 to 10 minute) responses in insulin, C-peptide, GLP-1, gastric inhibitory peptide, and PP. BAs exhibited divergent trends in G allele carriers vs noncarriers concomitant with differential FGF19 responses. CD36 plays an important role in the preabsorptive hormone and BA responses that coordinate brain and gut regulation of energy metabolism.

Structural, thermal and optical properties of TeO2-ZnO-CdO-BaO glasses doped with VO(2+).

PubMed

Sreenivasulu, V; Upender, G; Chandra Mouli, V; Prasad, M

2015-09-05

The glasses with composition 64TeO2-15ZnO-(20-x)CdO-xBaO-1V2O5 (0⩽x⩽20 mol%) were prepared by conventional melt quenching technique. X-ray diffraction analysis was used to confirm the amorphous nature of the glasses. The optical absorption studies revealed that the cut-off wavelength (λα) decreases while optical band gap energy (Eopt) and Urbach energy (ΔE) values increase with an increase of BaO content. Refractive index (n) evaluated from Eopt was found to decrease with an increase of BaO content. The physical parameters such as density (ρ), molar volume (Vm), oxygen packing density (OPD), optical basicity (Λ), molar refraction (Rm), and metallization criterion (M) evaluated and discussed. FTIR and Raman spectroscopic studies showed that the glass network consists of TeO4, TeO3+1/TeO3 and ZnO4 units as basic structural units. The glass transition temperature (Tg) of glass sample, onset crystallization temperature (To) and thermal stability ΔT were determined from Differential Scanning Calorimetry (DSC). Using electron paramagnetic resonance (EPR) spectra of vanadium glasses the spin Hamiltonian parameters and dipolar hyperfine coupling parameters of VO(2+) ions were calculated. It was found that V(4+) ions in these glasses exist as VO(2+) in octahedral coordination with a tetragonal distortion and have C4V symmetry with ground state dxy. Tetragonality (Δg∥/Δg⊥) of vanadium ion sites exhibited non-linear variation with BaO content. Copyright © 2015 Elsevier B.V. All rights reserved.

Induction of cross-priming of naive CD8+ T lymphocytes by recombinant bacillus Calmette-Guerin that secretes heat shock protein 70-major membrane protein-II fusion protein.

PubMed

Mukai, Tetsu; Maeda, Yumi; Tamura, Toshiki; Matsuoka, Masanori; Tsukamoto, Yumiko; Makino, Masahiko

2009-11-15

Because Mycobacterium bovis bacillus Calmette-Guérin (BCG) unconvincingly activates human naive CD8(+) T cells, a rBCG (BCG-70M) that secretes a fusion protein comprising BCG-derived heat shock protein (HSP)70 and Mycobacterium leprae-derived major membrane protein (MMP)-II, one of the immunodominant Ags of M. leprae, was newly constructed to potentiate the ability of activating naive CD8(+) T cells through dendritic cells (DC). BCG-70M secreted HSP70-MMP-II fusion protein in vitro, which stimulated DC to produce IL-12p70 through TLR2. BCG-70M-infected DC activated not only memory and naive CD8(+) T cells, but also CD4(+) T cells of both types to produce IFN-gamma. The activation of these naive T cells by BCG-70M was dependent on the MHC and CD86 molecules on BCG-70M-infected DC, and was significantly inhibited by pretreatment of DC with chloroquine. Both brefeldin A and lactacystin significantly inhibited the activation of naive CD8(+) T cells by BCG-70M through DC. Thus, the CD8(+) T cell activation may be induced by cross-presentation of Ags through a TAP- and proteosome-dependent cytosolic pathway. When naive CD8(+) T cells were stimulated by BCG-70M-infected DC in the presence of naive CD4(+) T cells, CD62L(low)CD8(+) T cells and perforin-producing CD8(+) T cells were efficiently produced. MMP-II-reactive CD4(+) and CD8(+) memory T cells were efficiently produced in C57BL/6 mice by infection with BCG-70M. These results indicate that BCG-70M activated DC, CD4(+) T cells, and CD8(+) T cells, and the combination of HSP70 and MMP-II may be useful for inducing better T cell activation.

Skin-Resident T Cells Drive Dermal Dendritic Cell Migration in Response to Tissue Self-Antigen.

PubMed

Ali, Niwa; Zirak, Bahar; Truong, Hong-An; Maurano, Megan M; Gratz, Iris K; Abbas, Abul K; Rosenblum, Michael D

2018-05-01

Migratory dendritic cell (DC) subsets deliver tissue Ags to draining lymph nodes (DLNs) to either initiate or inhibit T cell-mediated immune responses. The signals mediating DC migration in response to tissue self-antigen are largely unknown. Using a mouse model of inducible skin-specific self-antigen expression, we demonstrate that CD103 + dermal DCs (DDCs) rapidly migrate from skin to skin DLN (SDLNs) within the first 48 h after Ag expression. This window of time was characterized by the preferential activation of tissue-resident Ag-specific effector T cells (Teffs), with no concurrent activation of Ag-specific Teffs in SDLNs. Using genetic deletion and adoptive transfer approaches, we show that activation of skin-resident Teffs is required to drive CD103 + DDC migration in response to tissue self-antigen and this Batf3-dependent DC population is necessary to mount a fulminant autoimmune response in skin. Conversely, activation of Ag-specific Teffs in SDLNs played no role in DDC migration. Our studies reveal a crucial role for skin-resident T cell-derived signals, originating at the site of self-antigen expression, to drive DDC migration during the elicitation phase of an autoimmune response. Copyright © 2018 by The American Association of Immunologists, Inc.

Mechanical properties of high-temperature superconducting wires. Ph.D. Thesis - Illinois Inst. of Tech.

NASA Technical Reports Server (NTRS)

Goretta, K. C.; Cluff, J. A.; Joo, J.; Lanagan, M. T.; Singh, J. P.; Vasanthamohan, N.; Xin, Y.; Wong, K. W.

1995-01-01

Bending strength, fracture toughness, and elastic modulus data were acquired for YBa2Cu3O(x), Bi2Sr2CaCu2O(x) (Bi,Pb)2Sr2Ca2Cu3O(x), and Tl2Ba2Ca2Cu3O(x) bars. These data and thermal expansion coefficients strongly suggest that the maximum possible tensile strain without fracture of bulk tapes or wires is approximately equals 0.2%. In Ag-clad conductors, residual stresses will be of limited benefit, but fractures produced by larger strains can be accommodated by shunting current through the Ag.

Ratiometric electrochemiluminescent strategy regulated by electrocatalysis of palladium nanocluster for immunosensing.

PubMed

Huang, Yin; Lei, Jianping; Cheng, Yan; Ju, Huangxian

2016-03-15

This work designed a novel ratiometric electrochemiluminescence (ECL) immunosensing approach based on two different ECL emitters: CdS quantum dots (QDs) as cathodic emitter and luminol as anodic emitter. The ECL immunosensor was constructed by a layer-by-layer modification of CdS QDs, Au nanoparticles and capture antibody on a glassy carbon electrode. With hydrogen peroxide as ECL coreactant, the immunosensor showed a cathodic ECL emission of CdS QDs at -1.5 V (vs Ag/AgCl) in air-saturated pH 8.0 buffer. Upon the formation of sandwich immunoassay, the lumiol/palladium nanoclusters (Pd NCs)@graphene oxide probe was introduced to the electrode. Therefore, the cathodic ECL intensity decreased and luminol anodic ECL emission was appeared at +0.3 V (vs Ag/AgCl) owing to the competition of the coreactant of hydrogen peroxide. Using carcino-embryonic antigen as model, this ratiometric ECL strategy could be used for immunoassay with a linear range of 1.0-100 pg mL(-1) and a detection limit of 0.62 pg mL(-1). The enhanced ratiometric ECL signal resulted from the high density and excellent electrocatalysis of the loaded Pd NCs. The immunosensor exhibited good stability and acceptable fabrication reproducibility and accuracy, showing a great promising for clinical application. This electrocatalysis-regulated ratiometric ECL provides a new concept for ECL measurement, and could be conveniently extended for detection of other protein biomarkers. Copyright © 2015 Elsevier B.V. All rights reserved.

Vaccination with poly(D,L-lactide-co-glycolide) nanoparticles loaded with soluble Leishmania antigens and modified with a TNFα-mimicking peptide or monophosphoryl lipid A confers protection against experimental visceral leishmaniasis.

PubMed

Margaroni, Maritsa; Agallou, Maria; Athanasiou, Evita; Kammona, Olga; Kiparissides, Costas; Gaitanaki, Catherine; Karagouni, Evdokia

2017-01-01

Visceral leishmaniasis (VL) persists as a major public health problem, and since the existing chemotherapy is far from satisfactory, development of an effective vaccine emerges as the most appropriate strategy for confronting VL. The development of an effective vaccine relies on the selection of the appropriate antigen and also the right adjuvant and/or delivery vehicle. In the present study, the protective efficacy of poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles (NPs), which were surface-modified with a TNFα-mimicking eight-amino-acid peptide (p8) and further functionalized by encapsulating soluble Leishmania infantum antigens (sLiAg) and monophosphoryl lipid A (MPLA), a TLR4 ligand, was evaluated against challenge with L. infantum parasites in BALB/c mice. Vaccination with these multifunctionalized PLGA nanoformulations conferred significant protection against parasite infection in vaccinated mice. In particular, vaccination with PLGA-sLiAg-MPLA or p8-PLGA-sLiAg NPs resulted in almost complete elimination of the parasite in the spleen for up to 4 months post-challenge. Parasite burden reduction was accompanied by antigen-specific humoral and cellular immune responses. Specifically, injection with PLGA-sLiAg-MPLA raised exclusively anti-sLiAg IgG1 antibodies post-vaccination, while in p8-PLGA-sLiAg-vaccinated mice, no antibody production was detected. However, 4 months post-challenge, in mice vaccinated with all the multifunctionalized NPs, antibody class switching towards IgG2a subtype was observed. The study of cellular immune responses revealed the increased proliferation capacity of spleen cells against sLiAg, consisting of IFNγ-producing CD4 + and CD8 + T cells. Importantly, the activation of CD8 + T cells was exclusively attributed to vaccination with PLGA NPs surface-modified with the p8 peptide. Moreover, characterization of cytokine production in vaccinated-infected mice revealed that protection was accompanied by significant increase of IFNγ and lower levels of IL-4 and IL-10 in protected mice when compared to control infected group. Conclusively, the above nanoformulations hold promise for future vaccination strategies against VL.

Immunosuppressive myeloid-derived suppressor cells can be converted into immunogenic APCs with the help of activated NKT cells: an alternative cell-based antitumor vaccine.

PubMed

Ko, Hyun-Jeong; Lee, Jung-Mi; Kim, Yeon-Jeong; Kim, Yun-Sun; Lee, Kyoo-A; Kang, Chang-Yuil

2009-02-15

Myeloid-derived suppressor cells (MDSCs), which are known to be accumulated in the blood, spleen, and bone marrow of tumor-bearing mice and cancer patients, were tested as APCs for a cellular vaccine because they have phenotypical similarity with inflammatory monocytes and may be differentiated from the same precursors as monocytes. Although MDSCs have immunosuppressive properties, in vivo transferred MDSCs, which present tumor Ag and NKT cell ligand (alpha-galactosylceramide), significantly prolonged survival time in metastatic tumor-bearing mice in a CD8(+) cell-, NK cell-, and NKT cell-dependent manner vs a CD4(+) T cell- and host dendritic cell-independent manner. Major concerns about using MDSCs as APCs in a vaccine are their suppression of CTLs and their induction of Foxp3(+) regulatory T cells. However, alpha-galactosylceramide-loaded MDSCs did not suppress CD4(+) and CD8(+) T cells and allowed for the generation of Ag-specific CTL immunity without increasing the generation of regulatory T cells. Furthermore, stimulation with activated NKT cells induced changes on MDSCs in phenotypical or maturation markers, including CD11b, CD11c, and CD86. Taken together, these findings suggest that NKT cells facilitate the conversion of immunosuppressive MDSCs into immunogenic APCs, eliciting successful antitumor immunity and providing the basis for alternative cell-based vaccines.

Retention of Ag-specific memory CD4+ T cells in the draining lymph node indicates lymphoid tissue resident memory populations.

PubMed

Marriott, Clare L; Dutton, Emma E; Tomura, Michio; Withers, David R

2017-05-01

Several different memory T-cell populations have now been described based upon surface receptor expression and migratory capabilities. Here we have assessed murine endogenous memory CD4 + T cells generated within a draining lymph node and their subsequent migration to other secondary lymphoid tissues. Having established a model response targeting a specific peripheral lymph node, we temporally labelled all the cells within draining lymph node using photoconversion. Tracking of photoconverted and non-photoconverted Ag-specific CD4 + T cells revealed the rapid establishment of a circulating memory population in all lymph nodes within days of immunisation. Strikingly, a resident memory CD4 + T cell population became established in the draining lymph node and persisted for several months in the absence of detectable migration to other lymphoid tissue. These cells most closely resembled effector memory T cells, usually associated with circulation through non-lymphoid tissue, but here, these cells were retained in the draining lymph node. These data indicate that lymphoid tissue resident memory CD4 + T-cell populations are generated in peripheral lymph nodes following immunisation. © 2017 The Authors. European Journal of Immunology published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Exposure assessment of heavy metals on abandoned metal mine areas by ingestion of soil, crop plant and groundwater

NASA Astrophysics Data System (ADS)

Lee, J.-S.; Chon, H.-T.

2003-05-01

In order to assess the risk of adverse health effects on human exposure to arsenic and heavy metals influence by past mining activities, environmental geochemical survey was undertaken in the abandoned metal mine areas (Dongil Au-Ag-Cu-Zn mine, Okdong Cu-Pb-Zn mine, Myungbong Au-Ag mine). Arsenic and other heavy metals were highly elevated in the tailings from the Dongil mine (8,720 As mg/kg, 5.9 Cd mg/kg, 3,610 Cu mg/kg, 5,850 Pb mg/kg, 630 Zn mg/kg). Heavy metals except As from the Okdong mine (53.6 Cd mg/kg, 910 Cu mg/kg, 1,590 Pb mg/kg, 5,720 Zn mg/kg) and As from the Myungbong mine (5,810 As mg/kg) were also elevated. Elevated levels of As, Cd and Zn were also found in agricultural soils from these mine areas. The H.I. (hazard index) values of As and Cd from the Dongil, the Okdong and Myungbong mine areas are higher than 1.0. Therefore, toxic risk for As and Cd exist via exposure (ingestion) of contaminated soil, groundwater and rice grain in these mine areas.

Chiral SiO2 and Ag@SiO2 Materials Templated by Complexes Consisting of Comblike Polyethyleneimine and Tartaric Acid.

PubMed

Yao, Dong-Dong; Murata, Hiroki; Tsunega, Seiji; Jin, Ren-Hua

2015-10-26

A facile avenue to fabricate micrometer-sized chiral (L-, D-) and meso-like (dl-) SiO2 materials with unique structures by using crystalline complexes (cPEI/tart), composed of comblike polyethyleneimine (cPEI) and L-, D-, or dl-tartaric acid, respectively, as catalytic templates is reported. Interestingly, both chiral crystalline complexes appeared as regularly left- and right-twisted bundle structures about 10 μm in length and about 5 μm in diameter, whereas the dl-form occurred as circular structures with about 10 μm diameter. Subsequently, SiO2 @cPEI/tart hybrids with high silica content (>55.0 wt %) were prepared by stirring a mixture containing tetramethoxysilane (TMOS) and the aggregates of the crystalline complexes in water. The chiral SiO2 hybrids and calcined chiral SiO2 showed very strong CD signals and a nanofiber-based morphology on their surface, whereas dl-SiO2 showed no CD activity and a nanosheet-packed disklike shape. Furthermore, metallic silver nanoparticles (Ag NPs) were encapsulated in each silica hybrid to obtain chiral (D and L forms) and meso-like (dl form) Ag@SiO2 composites. Also, the reaction between L-cysteine (Lcys) and these Ag@SiO2 composites was preliminarily investigated. Only chiral L- and D-Ag@SiO2 composites promoted the reaction between Lcys and Ag NPs to produce a molecular [Ag-Lcys]n complex with remarkable exciton chirality, whereas the reaction hardly occurred in the case of meso-like (dl-) Ag@SiO2 composite. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Thermodynamic and kinetic studies of As2O3 toxicological effects on human insulin in generation diabetes mellitus

NASA Astrophysics Data System (ADS)

Mohsennia, Mohsen; Motaharinejad, Atieh; Rafiee-Pour, Hossain-Ali; Torabbeigi, Marzieh

2017-12-01

The interaction of arsenic trioxide with human insulin was investigated by circular dichroism (CD), cyclic voltammetry and electrophoresis techniques. The interfacial behavior of insulin in presence of As2O3 onto the Ag electrode surface was studied at 310 K in phosphate buffer solution (PBS). According to Far-UV CD spectroscopy results, As2O3 caused to decrease in structural compactness and variety of alpha helix into beta structures. Near-UV CD indicated that As2O3 dissociates disulfide linkage in insulin structure. The kinetic parameters, including charge-transfer coefficient and apparent heterogeneous electron transfer rate constant were also determined. The thermodynamic parameters of insulin denaturation in presence of arsenic trioxide were calculated and reported. The obtained results indicated strong adsorption of insulin in presence of arsenic trioxide onto the Ag surface via chemisorptions.

Environmental characterisation of sewage sludge/paper ash-based composites in relation to their possible use in civil engineering.

PubMed

Mladenovič, Ana; Hamler, Sandra; Zupančič, Nina

2017-01-01

The environmental acceptability of geotechnical composites made of treated municipal sewage sludge (SwS) and paper ash (PA) after two different curing periods has been investigated. The mineral composition of such composites, including their content of major oxides, is mainly influenced by the PA. The content of potentially toxic elements (PTEs) in the initial materials and in the composites varies considerably. In the SwS the Ba, Cd, Cr, Cu, Hg, Ni and Zn contents are above the legally permitted limits. The PTE content of PA are lower, but still somewhat above the permitted values for Ba and Cu. Mixing these two materials together resulted in a decrease in the PTE, but the Ba, Cu and Zn contents are still too high for agricultural application. However, leachates from composites that had been cured for 28 days are highly alkaline, and the As, Ba, Cd, Cr, Hg, Mo, Ni, Pb and Zn contents in them are well below the permitted values. The Cu contents (2.4 to 5.4 mg/kg) are above the permitted limit for inert material, but inside the range for non-hazardous material. In a leachate of composite which was prepared with fresh PA and a lower PA to SwS ratio, the Cu content was 1.4 mg/kg, since fresh PA is more reactive and therefore has a higher ability to immobilise Cu. Therefore, such mixtures can be utilised for covers and liners for sanitary landfills.

Conserved Region C Functions To Regulate PD-1 Expression and Subsequent CD8 T Cell Memory.

PubMed

Bally, Alexander P R; Tang, Yan; Lee, Joshua T; Barwick, Benjamin G; Martinez, Ryan; Evavold, Brian D; Boss, Jeremy M

2017-01-01

Expression of programmed death 1 (PD-1) on CD8 T cells promotes T cell exhaustion during chronic Ag exposure. During acute infections, PD-1 is transiently expressed and has the potential to modulate CD8 T cell memory formation. Conserved region C (CR-C), a promoter proximal cis-regulatory element that is critical to PD-1 expression in vitro, responds to NFATc1, FoxO1, and/or NF-κB signaling pathways. Here, a CR-C knockout mouse was established to determine its role on PD-1 expression and the corresponding effects on T cell function in vivo. Deletion of CR-C decreased PD-1 expression on CD4 T cells and Ag-specific CD8 T cells during acute and chronic lymphocytic choriomeningitis virus challenges, but did not affect the ability to clear an infection. Following acute lymphocytic choriomeningitis virus infection, memory CD8 T cells in the CR-C knockout mouse were formed in greater numbers, were more functional, and were more effective at responding to a melanoma tumor than wild-type memory cells. These data implicate a critical role for CR-C in governing PD-1 expression, and a subsequent role in guiding CD8 T cell differentiation. The data suggest the possibility that titrating PD-1 expression during CD8 T cell activation could have important ramifications in vaccine development and clinical care. Copyright © 2016 by The American Association of Immunologists, Inc.

Geochemical influences on assimilation of sediment-bound metals in clams and mussels

USGS Publications Warehouse

Griscom, S.B.; Fisher, N.S.; Luoma, S.N.

2000-01-01

A series of experiments was performed to evaluate the extent to which Cd, Co, Ag, Se, Cr, and Zn bound to sediments with different geochemical properties could be assimilated by the mussel Mytilus edulis and the clam Macoma balthica. Oxidized and reduced radiolabeled sediments were fed to suspension-feeding animals, the depuration patterns of the individuals were followed by ??-spectrometry, and the assimilation efficiencies (AEs) of ingested metals were determined. AEs from geochemically diverse sediments typically varied less than 2-fold and ranged from 1% for Cr to 42% for Zn. Metals were assimilated from anoxic sediment by both animals; Ag, Cd, and Co AEs in M. balthica were 9-16%, 2-fold lower than from oxic sediment, but in M. edulis AEs were about two times greater from anoxic sediment for all metals but Ag. For oxic sediment, Cd and Co AEs in M. edulis decreased 3-4-fold with increased sediment exposure time to the metals with smaller but significant effects also noted for Zn and Se but not Ag. A less pronounced decrease in AE for M. balthica was evident only after 6 months exposure time. Sequential extractions of the oxidized sediments showed a transfer of metals into more resistant sediment components over time, but the rate did not correlate with a decrease in metal AEs. Comparing the two bivalves, TOC concentrations had an inconsistent effect on metal AEs. AEs of metals from bacteria-coated glass beads were slightly higher than from humic acid-coated beads, which were comparable with whole-sediment AEs. There was correspondence of AE with desorption of Ag, Cd, Co, and Se (but not Zn) from sediments into pH 5 seawater, measured to simulate the gut pH of these bivalves. The results imply that metals associated with sulfides and anoxic sediments are bioavailable, that the bioavailability of metals from sediments decreases over exposure time, that organic carbon content generally has a small effect on AEs, and that AEs of sediment-bound metals differ among species.

Comparison of trace element concentrations in livers of diseased, emaciated and non-diseased southern sea otters from the California coast

USGS Publications Warehouse

Kannan, K.; Agusa, T.; Perrotta, E.; Thomas, N.J.; Tanabe, S.

2006-01-01

Infectious diseases have been implicated as a cause of high rates of adult mortality in southern sea otters. Exposure to environmental contaminants can compromise the immuno-competence of animals, predisposing them to infectious diseases. In addition to organic pollutants, certain trace elements can modulate the immune system in marine mammals. Nevertheless, reports of occurrence of trace elements, including toxic heavy metals, in sea otters are not available. In this study, concentrations of 20 trace elements (V, Cr, Mn, Co, Cu, Zn, Rb, Sr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, Hg, Tl, Pb, and Bi) were measured in livers of southern sea otters found dead along the central California coast (n = 80) from 1992 to 2002. Hepatic concentrations of trace elements were compared among sea otters that died from infectious diseases (n = 27), those that died from non-infectious causes (n = 26), and otters that died in emaciated condition with no evidence of another cause of death (n = 27). Concentrations of essential elements in sea otters varied within an order of magnitude, whereas concentrations of non-essential elements varied by two to five orders of magnitude. Hepatic concentrations of Cu and Cd were 10- to 100-fold higher in the sea otters in this study than concentrations reported for any other marine mammal species. Concentrations of Mn, Co, Zn, and Cd were elevated in the diseased and emaciated sea otters relative to the non-diseased sea otters. Elevated concentrations of essential elements such as Mn, Zn, and Co in the diseased/emaciated sea otters suggest that induction of synthesis of metallothionein and superoxide dismutase (SOD) enzyme is occurring in these animals, as a means of protecting the cells from oxidative stress-related injuries. Trace element profiles in diseased and emaciated sea otters suggest that oxidative stress mediates the perturbation of essential-element concentrations. Elevated concentrations of toxic metals such as Cd, in addition to several other organic pollutants, may contribute to oxidative stress-meditated effects in sea otters.

Metal concentrations in the mussel Bathymodiolus platifrons from a cold seep in the South China Sea

NASA Astrophysics Data System (ADS)

Wang, Xiaocheng; Li, Chaolun; Zhou, Li

2017-11-01

Data regarding the concentration and distribution of various metals in different tissues of mussels from the cold seep is scant. We aimed to quantify the presence of twenty elements (Ca, K, Mg, Sr, Ag, Al, As, Ba, Cd, Co, Cr, Cu, Li, Fe, Mn, Mo, Ni, Pb, V, and Zn) in gills, mantles and shells of Bathymodiolus platifrons, a common mussel species in deep-sea cold seep and hydrothermal vent communities. Specimens of B. platifrons were sampled from a cold seep at the northern continental slope of the South China Sea and the elemental contents in its tissues were quantified. Our findings were compared to data from taxonomically similar species at hydrothermal vents and coastal waters. We found that most elements were significantly enriched in the gills, which could be related to food uptake and the existence of endosymbionts. In shells and mantles, Mn was particularly rich, possibly due to its replacement of Ca in the carbonate structure. A significant positive correlation among Ca, Sr, and Mg was found in both gills and mantles, consistent with relationships observed in vent and littoral mussel species. Concentrations of metals were highest in the new-growth outer edges of shells in comparison to older shell material, which suggests that trace metals have become more abundant in the ambient seawater in recent years. Compared with other deep-sea environments and coastal areas, metal accumulation showed local variability but similar overall patterns of uptake and accumulation, indicating that essential elemental requirements in different mussel species may be similar across taxa. The high bioconcentration factor (BCF) values of Mn and Ag suggest that their particular functions and regulation mechanisms are related to specific adaptations and life cycle processes.

T cell-intrinsic factors contribute to the differential ability of CD8+ T cells to rapidly secrete IFN-γ in the absence of antigen.

PubMed

Bou Ghanem, Elsa N; Nelson, Christina C; D'Orazio, Sarah E F

2011-02-01

A subset of CD44(hi)CD8(+) T cells isolated from C57BL/6/J (B6) mice, but not BALB/c/By/J (BALB/c) mice, rapidly secrete IFN-γ within 16 h of infection with Listeria monocytogenes. This Ag-independent response requires the presence of both IL-12 and IL-18. Previous studies showed that dendritic cells from B6 mice produced more Th1-type cytokines such as IL-12 than did those from BALB/c mice in response to L. monocytogenes infection. In this report, we demonstrate that the microenvironment in L. monocytogenes-infected BALB/c mice is sufficient to induce responsive B6 CD8(+) T cells to rapidly secrete IFN-γ. Furthermore, BALB/c CD8(+) T cells did not rapidly secrete IFN-γ even when they were exposed to high concentrations of IL-12 plus IL-18 in vitro. In the presence of IL-12 and IL-18, B6 CD44(hi)CD8(+) T cells upregulated expression of the receptor subunits for these cytokines more rapidly than did BALB/c T cells. In comparing particular subsets of memory phenotype CD8(+) T cells, we found that virtual memory cells, rather than true Ag-experienced cells, had the greatest level of impairment in BALB/c mice. These data suggest that the degree of cytokine-driven bystander activation of CD8(+) T cells that occurs during infection depends on both APCs and T cell-intrinsic properties that can vary among mouse strains.

Variation of photoluminescence features in Pr{sup 3+} doped lithium-fluoro-borate glass by changing different modifier oxides (MgO, CaO, CdO and PbO)-Judd-Ofelt theory application

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

Balakrishna, A.; Rajesh, D.; Babu, S.

2015-06-24

Pr{sup 3+} (1.0 mol%) doped different modifier oxide based six lithium-fluoro-borate glasses with chemical composition of 49Li{sub 2}B{sub 4}O{sub 7}-20BaF{sub 2}-10NaF-20MO (where M= Mg, Ca, Cd and Pb), 49Li{sub 2}B{sub 4}O{sub 7}-20BaF{sub 2}-10NaF-10MgO-10CaO and 49Li{sub 2}B{sub 4}O{sub 7}-20BaF{sub 2}-10NaF-10CdO-10PbO were prepared by conventional melt quenching technique. Judd-Ofelt theory has been applied for evaluating the Judd-Ofelt intensity parameters for Pr{sup 3+} ion in these glass compositions and are in turn to used to predict radiative properties such as radiative transition probabilities (A{sub T}), branching ratios (β) and stimulated emission cross-section (σ{sub P}). Stimulated emission cross-section (σ{sub p}) of prominent emission transitions,more » {sup 3}P{sub 0}→{sup 3}H{sub 4} and {sup 1}D{sub 2}→{sup 3}H{sub 4} of Pr{sup 3+} ion in all lithium-fluoro-borate glasses were calculated. Among all the emission transitions, {sup 3}P{sub 0}→{sup 3}H{sub 4} posseses higher branching ratio and stimulated emission cross-section in Mg-Ca glass, which leads to the best laser excitation at 487 nm wavelength.« less

A flexible top-emitting organic light-emitting diode on steel foil

NASA Astrophysics Data System (ADS)

Xie, Zhiyuan; Hung, Liang-Sun; Zhu, Furong

2003-11-01

An efficient flexible top-emitting organic light-emitting diode (FTOLED) was developed on a thin steel foil. The FTOLED was constructed on the spin-on-glass (SOG)-coated steel substrate with an organic stack of NPB/Alq 3 sandwiched by a highly reflective Ag anode and a semitransparent Sm cathode. An ultrathin plasma-polymerized hydrocarbon film (CF X) was interposed between the Ag anode and the NPB layer to enhance hole-injection, and an additional Alq 3 layer was overlaid on the Sm cathode to increase light output. The FTOLED showed a peak efficiency of 4.4 cd/A higher than 3.7 cd/A of a convention NPB/Alq 3-based bottom-emitting OLED.

Rice seed toxicity tests for organic and inorganic substances

USGS Publications Warehouse

Wang, W.

1994-01-01

Plant seed toxicity tests can be used to evaluate hazardous waste sites and to assess toxicity of complex effluents and industrial chemicals. Conventional plant seed toxicity tests are performed using culture dishes containing filter paper. Some reports indicate that filter papers might interfere with the toxicity of inorganic substances. In this study, a plastic seed tray was used. Rice was used as the test species. A comparison of results in the literature and this study revealed that variation of test species, methods, exposure duration, and other factors may affect the test results. The results of this study showed that the order of decreasing toxicity of metal ions was Cu>Ag>Ni>Cd>Cr(VI)>Pb>Zn>Mn>NaF for rice. The test results were similar to those reported in the literature for lettuce Ag>Ni>Cd,Cu>Cr (VI)>Zn>Mn, millet Cu,Ni>Cd>Cr(VI)>Zn>Mn, and ryegrass Cu>Ni>Mn>>Pb>Cd>Zn> Al>Hg>Cr>Fe. The order of decreasing toxicity of organic herbicides was paraquat, 2,4-D>>glyphosate>bromacil.

Ligand reprogramming in dinuclear helicate complexes: a consequence of allosteric or electrostatic effects?

PubMed

Jeffery, John C; Rice, Craig R; Harding, Lindsay P; Baylies, Christian J; Riis-Johannessen, Thomas

2007-01-01

The ditopic ligand 6,6'-bis(4-methylthiazol-2-yl)-3,3'-([18]crown-6)-2,2'-bipyridine (L(1)) contains both a potentially tetradentate pyridyl-thiazole (py-tz) N-donor chain and an additional "external" crown ether binding site which spans the central 2,2'-bipyridine unit. In polar solvents (MeCN, MeNO(2)) this ligand forms complexes with Zn(II), Cd(II), Hg(II) and Cu(I) ions via coordination of the N donors to the metal ion. Reaction with both Hg(II) and Cu(I) ions results in the self-assembly of dinuclear double-stranded helicate complexes. The ligands are partitioned by rotation about the central py--py bond, such that each can coordinate to both metals as a bis-bidentate donor ligand. With Zn(II) ions a single-stranded mononuclear species is formed in which one ligand coordinates the metal ion in a planar tetradentate fashion. Reaction with Cd(II) ions gives rise to an equilibrium between both the dinuclear double-stranded helicate and the mononuclear species. These complexes can further coordinate s-block metal cations via the remote crown ether O-donor domains; a consequence of which are some remarkable changes in the binding modes of the N-donor domains. Reaction of the Hg(II)- or Cd(II)-containing helicate with either Ba(2+) or Sr(2+) ions effectively reprogrammes the ligand to form only the single-stranded heterobinuclear complexes [MM'(L(1))](4+) (M=Hg(II), Cd(II); M'=Ba(2+), Sr(2+)), where the transition and s-block cations reside in the N- and O-donor sites, respectively. In contrast, the same ions have only a minor structural impact on the Zn(II) species, which already exists as a single-stranded mononuclear complex. Similar reactions with the Cd(II) system result in a shift in equilibrium towards the single-stranded species, the extent of which depends on the size and charge of the s-block cation in question. Reaction of the dicopper(I) double-stranded helicate with Ba(2+) shows that the dinuclear structure still remains intact but the pitch length is significantly increased.

BariumCopperChFluorine (Ch = Sulfur, Selenium, Tellurium) p-type transparent conductors

NASA Astrophysics Data System (ADS)

Zakutayev, Andriy

BaCuChF (Ch = S, Se, Te) materials are chalcogen-based transparent conductors with wide optical band gaps (2.9 -- 3.5 eV) and a high concentration of free holes (1018 -- 1020 cm-3 ) caused by the presence of copper vacancies. Chalcogen vacancies compensate copper vacancies in these materials, setting the Fermi level close to the valence band maximum. BaCuChF thin film solid solutions prepared by pulsed laser deposition (PLD) have tunable properties, such as lattice constants, conductivity and optical band gaps. BaCuSF and BaCuSeF materials also feature room-temperature stable 3D excitons with spin-orbit-split levels. BaCuTeF has forbidden lowest-energy optical transitions which extends its transparency range. BaCuChF surfaces oxidize when exposed to air, but can be protected using Ch capping layers. Polycrystalline BaCuSeF thin films have a 4.85 eV work function, a 0.11 eV hole injection barrier into ZnPc, and 0.00 eV valence band offset with ZnTe. BaCuSeF should have s similar band offset and similar interfacial properties with CdTe and Cu(InGa)Se2, and BaCuSF should have no valence band offset with Cu2ZnSnS4, according to the transitivity rule. Therefore, BaCuSeF is suitable for applications as a p-layer in organic light-emitting diodes, p-i-n double-heterojunction and tandem chalcogenide solar cells.

Spatial variability of trace metals and inorganic nutrients in surface waters of Todos Santos Bay, México in the summer of 2005 during a red tide algal bloom.

PubMed

Lares, M L; Marinone, S G; Rivera-Duarte, I; Beck, A; Sañudo-Wilhelmy, S

2009-05-01

Dissolved and particulate metals (Ag, Cd, Co, Cu, Ni, and Zn) and nutrients (PO(4), NO(3), and H(4)SiO(4)) were measured in Todos Santos Bay (TSB) in August 2005. Two sources producing local gradients were identified: one from a dredge discharge area (DDA) and another south of the port and a creek. The average concentrations of dissolved Cd and Zn (1.3 and 15.6 nM, respectively) were higher by one order of magnitude than the surrounding Pacific waters, even during upwelling, and it is attributed to the presence of a widespread and long-lasting red tide coupled with some degree of local pollution. A clear spatial gradient (10 to 6 pM), from coast to offshore, of dissolved Ag was evident, indicating the influence of anthropogenic inputs. The particulate fraction of all metals, except Cu, showed a factor of ~3 decrease in concentrations from the DDA to the interior of the bay. The metal distributions were related to the bay's circulation by means of a numerical model that shows a basically surface-wind-driven offshore current with subsurface compensation currents toward the coast. Additionally, the model shows strong vertical currents over the DDA. Principal component analysis revealed three possible processes that could be influencing the metal concentrations within TSB: anthropogenic inputs (Cd, Ag, and Co), biological proceses (NO(3), Zn, and Cu), and upwelling and mixing (PO(4), H(4)SiO(4), Cd, and Ni). The most striking finding of this study was the extremely high Cd concentrations, which have been only reported in highly contaminated areas. As there was a strong red tide, it is hypothesized that the dinoflagellates are assimilating the Cd, which is rapidly remineralized and being concentrated on the stratified surface layers.

Thermal fuse for high-temperature batteries

DOEpatents

Jungst, Rudolph G.; Armijo, James R.; Frear, Darrel R.

2000-01-01

A thermal fuse, preferably for a high-temperature battery, comprising leads and a body therebetween having a melting point between approximately 400.degree. C. and 500.degree. C. The body is preferably an alloy of Ag--Mg, Ag--Sb, Al--Ge, Au--In, Bi--Te, Cd--Sb, Cu--Mg, In--Sb, Mg--Pb, Pb--Pd, Sb--Zn, Sn--Te, or Mg--Al.

Comparative rice seed toxicity tests using filter paper, growth pouch-tm, and seed tray methods

USGS Publications Warehouse

Wang, W.

1993-01-01

Paper substrate, especially circular filter paper placed inside a Petri dish, has long been used for the plant seed toxicity test (PSTT). Although this method is simple and inexpensive, recent evidence indicates that it gives results that are significantly different from those obtained using a method that does not involve paper, especially when testing metal cations. The study compared PSTT using three methods: filter paper, Growth Pouch-TM, and seed tray. The Growth Pouch-TM is a commercially available device. The seed tray is a newly designed plastic receptacle placed inside a Petri dish. The results of the Growth Pouch-TM method showed no toxic effects on rice for Ag up to 40 mg L-1 and Cd up to 20 mg L-1. Using the seed tray method, IC50 (50% inhibitory effect concentration) values were 0.55 and 1.4 mg L-1 for Ag and Cd, respectively. Although results of filter paper and seed tray methods were nearly identical for NaF, Cr(VI), and phenol, the toxicities of cations Ag and Cd were reduced by using the filter paper method; IC50 values were 22 and 18 mg L-1, respectively. The results clearly indicate that paper substrate is not advisable for PSTT.

Relationship of CD86 surface marker expression and cytotoxicity on dendritic cells exposed to chemical allergen

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

Hulette, Ben C.; Ryan, Cindy A.; Gildea, Lucy A.

2005-12-01

Human peripheral blood-derived dendritic cells (DC) respond to a variety of chemical allergens by up-regulating expression of the co-stimulatory molecule CD86. It has been postulated that this measure might provide the basis for an in vitro alternative approach for the identification of skin sensitizing chemicals. We recently reported that DC, exposed in culture to the highest non-cytotoxic concentrations of various chemical allergens, displayed marginal up-regulation of membrane CD86 expression; the interpretation being that such changes were insufficiently sensitive for the purposes of hazard identification. For the work presented here, immature DC were derived from human monocytes and treated with themore » chemical allergens 2,4-dinitrobenzenesulfonic acid (DNBS), nickel sulfate (NiSO{sub 4}), p-phenylenediamine (PPD), Bandrowski's base (BB), hydroquinone (HQ) and propyl gallate (PG) for 48 h at concentrations which induced both no to slight to moderate cytotoxicity. For comparison, DC were treated with the irritants sodium dodecyl sulfate (SDS), benzoic acid (BA), and benzalkonium chloride (BZC) at concentrations resulting in comparable levels of cytotoxicity. CD86 expression, as measured by flow cytometry, was consistently up-regulated (ranging from 162 to 386% control) on DC treated with concentrations of chemical allergens that induced approximately 10-15% cytotoxicity. The irritants BA and BZC did not induce up-regulation of CD86 expression when tested at concentrations that induced similar levels of cytotoxicity. SDS, however, up-regulated CD86 expression to 125-138% of control in 2/4 preparations when tested at concentrations which induced similar toxicity. Our results confirm that chemical allergens up-regulate CD86 expression on blood-derived DC and illustrate further that up-regulation of CD86 surface marker expression is more robust when DC are treated with concentrations of chemical allergen that induce slight to moderate cytotoxicity.« less

A mid-twentieth century reduction in tropical upwelling inferred from coralline trace element proxies

NASA Astrophysics Data System (ADS)

Reuer, Matthew K.; Boyle, Edward A.; Cole, Julia E.

2003-05-01

The Cariaco Basin is an important archive of past climate variability given its response to inter- and extratropical climate forcing and the accumulation of annually laminated sediments within an anoxic water column. This study presents high-resolution surface coral trace element records ( Montastrea annularis and Siderastrea siderea) from Isla Tortuga, Venezuela, located within the upwelling center of this region. A two-fold reduction in Cd/Ca ratios (3.5-1.7 nmol/mol) is observed from 1946 to 1952 with no concurrent shift in Ba/Ca ratios. This reduction agrees with the hydrographic distribution of dissolved cadmium and barium and their expected response to upwelling. Significant anthropogenic variability is also observed from Pb/Ca analysis, observing three lead maxima since 1920. Kinetic control of trace element ratios is inferred from an interspecies comparison of Cd/Ca and Ba/Ca ratios (consistent with the Sr/Ca kinetic artifact), but these artifacts are smaller than the environmental signal and do not explain the Cd/Ca transition. The trace element records agree with historical climate data and differ from sedimentary faunal abundance records, suggesting a linear response to North Atlantic extratropical forcing cannot account for the observed historical variability in this region.

Vertical distribution of major, minor and trace elements in sediments from mud volcanoes of the Gulf of Cadiz: evidence of Cd, As and Ba fronts in upper layers

NASA Astrophysics Data System (ADS)

Carvalho, Lina; Monteiro, Rui; Figueira, Paula; Mieiro, Cláudia; Almeida, Joana; Pereira, Eduarda; Magalhães, Vítor; Pinheiro, Luís; Vale, Carlos

2018-01-01

Mud volcanoes are feature of the coastal margins where anaerobic oxidation of methane triggers geochemical signals. Elemental composition, percentage of fine particles and loss on ignition were determined in sediment layers of eleven gravity cores retrieved from four mud volcanoes (Sagres, Bonjardim, Soloviev and Porto) and three undefined structures located on the deep Portuguese margin of the Gulf of Cadiz. Calcium was positively correlated to Sr and inversely to Al as well as to most of the trace elements. Vertical profiles of Ba, Cd and As concentrations, and their ratios to Al, in Porto and Soloviev showed pronounced enhancements in the top 50-cm depth. Sub-surface enhancements were less pronounced in other mud volcanoes and were absent in sediments from the structures. These profiles were interpreted as diagenetic enrichments related to the anaerobic oxidation of methane originated from upward methane-rich fluxes. The observed barium fronts were most likely caused by the presence of barite which precipitated at the sulphate-methane transition zone. Cd and As enrichments have probably resulted from successive dissolution/precipitation of sulphides in response to vertical shifts of redox boundaries.

Emission and profile characteristic of polycyclic aromatic hydrocarbons in PM2.5 and PM10 from stationary sources based on dilution sampling

NASA Astrophysics Data System (ADS)

Kong, Shaofei; Ji, Yaqin; Li, Zhiyong; Lu, Bing; Bai, Zhipeng

2013-10-01

The mass concentrations and profile characteristic for 18 kinds of polycyclic aromatic hydrocarbons (PAHs) in PM2.5 and PM10 from stack gases for six types of stationary sources in Shandong Province, China were studied by a dilution sampling system and GC-MS analysis method from February to March in 2010. The mass concentrations of PM2.5 and PM10 from the six types of stationary sources varied in 8.2-79.4 mg m-3 and 23.3-156.7 mg m-3, respectively. The total mass concentrations of analyzed PAHs in PM2.5 and PM10 were in the ranges of 0.40-94.35 μg m-3 and 9.16-122.91 μg m-3. The most toxic ashes were from sinter and coke oven for both PM2.5 and PM10 with high carcinogenic PAHs concentrations. BbF, Phe, NaP, BghiP, Pyr, BaP and BeP were abundant which was different from formers and one of the key reasons may be the differences of sampling methods. Diversities in PAHs compositions existed between fly ashes within PM2.5 and PM10 fractions for coke oven according to coefficient of divergence (CD) values. PAHs profiles for PM10 emitted from coke oven were different from those of other stationary sources (with CD values higher than 0.35) and for PM2.5, it was the same for sinter (with most CD values close to 0.30). There existed similar PAHs markers for fine particles emitted from stationary sources excepted for the sinter. For PM10, PAHs markers were primary 3-ring PAHs except for the coke oven with BbF, IND and BghiP as its signatures. Diagnostic ratios of BaA/(BaA + Chr), Flu/(Flu + Pyr), BaP/(BaP + BeP), BeP/BghiP and IND/(IND + BghiP) could be not well distinguished for the six types of stationary sources with the maximum/minimum ratios lower than 2 for both PM2.5 and PM10 of fly ashes which should be not used for source identification studies. The mass concentrations and source profiles of PAHs should be updated timely for size-differentiated fly ashes from various stationary sources by dilution sampling method.

Fabrication of a microfluidic Ag/AgCl reference electrode and its application for portable and disposable electrochemical microchips.

PubMed

Zhou, Jianhua; Ren, Kangning; Zheng, Yizhe; Su, Jing; Zhao, Yihua; Ryan, Declan; Wu, Hongkai

2010-09-01

This report describes a convenient method for the fabrication of a miniaturized, reliable Ag/AgCl reference electrode with nanofluidic channels acting as a salt bridge that can be easily integrated into microfluidic chips. The Ag/AgCl reference electrode shows high stability with millivolt variations. We demonstrated the application of this reference electrode in a portable microfluidic chip that is connected to a USB-port microelectrochemical station and to a computer for data collection and analysis. The low fabrication cost of the chip with the potential for mass production makes it disposable and an excellent candidate for real-world analysis and measurement. We used the chip to quantitatively analyze the concentrations of heavy metal ions (Cd(2+) and Pb(2+)) in sea water. We believe that the Ag/AgCl reference microelectrode and the portable electrochemical system will be of interest to people in microfluidics, environmental science, clinical diagnostics, and food research.

Influence of Ag, Cd or Pb Addition on Electrical and Dielectric Properties of Bulk Glassy Se-Ge

NASA Astrophysics Data System (ADS)

El-Metwally, E. G.; Shakra, A. M.

2018-05-01

Bulk glassy samples of Se0.7Ge0.3 and Se0.7Ge0.25 X 0.05 (X = Ag, Cd or Pb) chalcogenide glass have been prepared by melt-quenching method. The studied compositions were examined in powder form by x-ray diffraction analysis. The direct-current (dc) conductivity σ_{{dc}} was measured for bulk samples in the temperature range from 303 K to 433 K, revealing enhancement with temperature for all samples. The results indicate two values of activation energy ( Δ E_{{σ1 }} and Δ E_{{σ2 }} ) due to two conduction mechanisms. Measurements of the alternating-current (ac) conductivity σ_{{ac}} ( ω ) and dielectric properties for bulk samples were carried out in the temperature range from 303 K to 433 K and frequency range from 1 kHz to 1 MHz. The ac conductivity σ_{{ac}} ( ω ) was temperature dependent and proportional to ωS , where S is the frequency exponent, which reduced with rising temperature, and ω is the angular frequency. These results are discussed based on a correlated barrier hopping model. The calculated values of the maximum height of the barrier W_{{M}} for each composition are consistent with carrier hopping over a potential barrier. The density of localized states N( {E_{{F}} } ) at the Fermi level lay in the range from 1019 eV-1 cm-3 to 1020 eV-1 cm-3, and increased with temperature. The dielectric constant ɛ1 ( ω ) and loss ɛ2 ( ω ) increased with temperature but decreased with frequency. The values of σ_{{dc}} , σ_{{ac}} ( ω ) , ɛ1 ( ω ) , and ɛ2 ( ω ) increased with temperature and with addition of Ag, Cd or Pb. The observed increase was greater for Se0.7Ge0.25Pb0.05 than for Se0.7Ge0.25Cd0.05, which was greater than for Se0.7Ge0.25Ag0.05.

Circular Dichroism reveals evidence of coupling between immunoglobulin constant and variable region secondary structure.

PubMed

Janda, Alena; Casadevall, Arturo

2010-04-01

Antibodies (Ab) are bifunctional molecules with two domains, a constant region (C) that confers effector properties and a variable (V) region responsible of antigen (Ag) binding. Historically the C and V regions were considered to be functionally independent, with Ag specificity being solely determined by the V region. However, recent studies suggest that the C region can affect Ab fine specificity. This has led to the proposal that the C(H) domain influences the structure of the V region, thus affecting Ab affinity and fine specificity. An inference from this proposal is that V region identical monoclonal Abs (mAbs) differing in C region (eg isotype) would manifest different secondary structures arising from isotype-induced variation in the V-C regions after Ag binding. We hypothesized that such effects could translate into differences in Circular Dichroism (CD) upon Ag-Ab complexes formation. Consequently we studied the interaction of a set of V region identical IgG(1), IgG(2a), IgG(2b) and IgG(3) mAbs with glucuronoxylomannan (GXM). The native CD spectra of the pairs IgG(1)/IgG(2a) and IgG(3)/IgG(2b) were strikingly similar, implying similar secondary structure content. GXM binding by IgG(1), IgG(2a), IgG(2b) and IgG(3) produced different CD changes, with the pairs IgG(1)/IgG(2a) and IgG(3)/IgG(2b) again manifesting qualitatively similar trends in secondary structure changes. The magnitude of the changes differed among the isotypes with IgG(2a)>IgG(3)>IgG(2b)>IgG(1). These differences in CD changes were interpreted to reflect differences in V-C secondary structures. Copyright 2010 Elsevier Ltd. All rights reserved.

Effective Combination Adjuvants Engage Both TLR and Inflammasome Pathways To Promote Potent Adaptive Immune Responses.

PubMed

Seydoux, Emilie; Liang, Hong; Dubois Cauwelaert, Natasha; Archer, Michelle; Rintala, Nicholas D; Kramer, Ryan; Carter, Darrick; Fox, Christopher B; Orr, Mark T

2018-05-16

The involvement of innate receptors that recognize pathogen- and danger-associated molecular patterns is critical to programming an effective adaptive immune response to vaccination. The synthetic TLR4 agonist glucopyranosyl lipid adjuvant (GLA) synergizes with the squalene oil-in-water emulsion (SE) formulation to induce strong adaptive responses. Although TLR4 signaling through MyD88 and TIR domain-containing adapter inducing IFN-β are essential for GLA-SE activity, the mechanisms underlying the synergistic activity of GLA and SE are not fully understood. In this article, we demonstrate that the inflammasome activation and the subsequent release of IL-1β are central effectors of the action of GLA-SE, as infiltration of innate cells into the draining lymph nodes and production of IFN-γ are reduced in ASC -/- animals. Importantly, the early proliferation of Ag-specific CD4 + T cells was completely ablated after immunization in ASC -/- animals. Moreover, numbers of Ag-specific CD4 + T and B cells as well as production of IFN-γ, TNF-α, and IL-2 and Ab titers were considerably reduced in ASC -/- , NLRP3 -/- , and IL-1R -/- mice compared with wild-type mice and were completely ablated in TLR4 -/- animals. Also, extracellular ATP, a known trigger of the inflammasome, augments Ag-specific CD4 + T cell responses, as hydrolyzing it with apyrase diminished adaptive responses induced by GLA-SE. These data thus demonstrate that GLA-SE adjuvanticity acts through TLR4 signaling and NLRP3 inflammasome activation to promote robust Th1 and B cell responses to vaccine Ags. The findings suggest that engagement of both TLR and inflammasome activators may be a general paradigm for induction of robust CD4 T cell immunity with combination adjuvants such as GLA-SE. Copyright © 2018 by The American Association of Immunologists, Inc.

Distribution of potentially hazardous trace elements in coals from Shanxi province, China

USGS Publications Warehouse

Zhang, J.Y.; Zheng, C.G.; Ren, D.Y.; Chou, C.-L.; Liu, J.; Zeng, R.-S.; Wang, Z.P.; Zhao, F.H.; Ge, Y.T.

2004-01-01

Shanxi province, located in the center of China, is the biggest coal base of China. There are five coal-forming periods in Shanxi province: Late Carboniferous (Taiyuan Formation), Early Permian (Shanxi Formation), Middle Jurassic (Datong Formation), Tertiary (Taxigou Formation), and Quaternary. Hundred and ten coal samples and a peat sample from Shanxi province were collected and the contents of 20 potentially hazardous trace elements (PHTEs) (As, B, Ba, Cd, Cl, Co, Cr, Cu, F, Hg, Mn, Mo, Ni, Pb, Sb, Se, Th, U, V and Zn) in these samples were determined by instrumental neutron activation analysis, atomic absorption spectrometry, cold-vapor atomic absorption spectrometry, ion chromatography spectrometry, and wet chemical analysis. The result shows that the brown coals are enriched in As, Ba, Cd, Cr, Cu, F and Zn compared with the bituminous coals and anthracite, whereas the bituminous coals are enriched in B, Cl, Hg, and the anthracite is enriched in Cl, Hg, U and V. A comparison with world averages and crustal abundances (Clarke values) shows that the Quaternary peat is highly enriched in As and Mo, Tertiary brown coals are highly enriched in Cd, Middle Jurassic coals, Early Permian coals and Late Carboniferous coals are enriched in Hg. According to the coal ranks, the bituminous coals are highly enriched in Hg, whereas Cd, F and Th show low enrichments, and the anthracite is also highly enriched in Hg and low enrichment in Th. The concentrations of Cd, F, Hg and Th in Shanxi coals are more than world arithmetic means of concentrations for the corresponding elements. Comparing with the United States coals, Shanxi coals show higher concentrations of Cd, Hg, Pb, Se and Th. Most of Shanxi coals contain lower concentrations of PHTEs. ?? 2004 Elsevier Ltd. All rights reserved.

Ag2S Quantum Dot-Sensitized Solar Cells by First Principles: The Effect of Capping Ligands and Linkers.

PubMed

Amaya Suárez, Javier; Plata, Jose J; Márquez, Antonio M; Fernández Sanz, Javier

2017-09-28

Quantum dots solar cells, QDSCs, are one of the candidates for being a reliable alternative to fossil fuels. However, the well-studied CdSe and CdTe-based QDSCs present a variety of issues for their use in consumer-goods applications. Silver sulfide, Ag 2 S, is a promising material, but poor efficiency has been reported for QDSCs based on this compound. The potential influence of each component of QDSCs is critical and key for the development of more efficient devices based on Ag 2 S. In this work, density functional theory calculations were performed to study the nature of the optoelectronic properties for an anatase-TiO 2 (101) surface sensitized with different silver sulfide nanoclusters. We demonstrated how it is possible to deeply tune of its electronic properties by modifying the capping ligands and linkers to the surface. Finally, an analysis of the electron injection mechanism for this system is presented.

Mycobacterium tuberculosis impairs dendritic cell functions through the serine hydrolase Hip1.

PubMed

Madan-Lala, Ranjna; Sia, Jonathan Kevin; King, Rebecca; Adekambi, Toidi; Monin, Leticia; Khader, Shabaana A; Pulendran, Bali; Rengarajan, Jyothi

2014-05-01

Mycobacterium tuberculosis is a highly successful human pathogen that primarily resides in host phagocytes, such as macrophages and dendritic cells (DCs), and interferes with their functions. Although multiple strategies used by M. tuberculosis to modulate macrophage responses have been discovered, interactions between M. tuberculosis and DCs are less well understood. DCs are the primary APCs of the immune system and play a central role in linking innate and adaptive immune responses to microbial pathogens. In this study, we show that M. tuberculosis impairs DC cytokine secretion, maturation, and Ag presentation through the cell envelope-associated serine hydrolase, Hip1. Compared to wild-type, a hip1 mutant strain of M. tuberculosis induced enhanced levels of the key Th1-inducing cytokine IL-12, as well as other proinflammatory cytokines (IL-23, IL-6, TNF-α, IL-1β, and IL-18) in DCs via MyD88- and TLR2/9-dependent pathways, indicating that Hip1 restricts optimal DC inflammatory responses. Infection with the hip1 mutant also induced higher levels of MHC class II and costimulatory molecules CD40 and CD86, indicating that M. tuberculosis impairs DC maturation through Hip1. Further, we show that M. tuberculosis promotes suboptimal Ag presentation, as DCs infected with the hip1 mutant showed increased capacity to present Ag to OT-II- and early secreted antigenic target 6-specific transgenic CD4 T cells and enhanced Th1 and Th17 polarization. Overall, these data show that M. tuberculosis impairs DC functions and modulates the nature of Ag-specific T cell responses, with important implications for vaccination strategies.

In vitro assessment of silver nanoparticles immunotoxicity.

PubMed

Galbiati, Valentina; Cornaghi, Laura; Gianazza, Elisabetta; Potenza, Marco A; Donetti, Elena; Marinovich, Marina; Corsini, Emanuela

2018-02-01

This study aimed to characterize unwanted immune effects of nanoparticles (NP) using THP-1 cells, human whole blood and enriched peripheral blood monocytes. Commercially available silver NP (AgNP < 100 nm, also confirmed by Single Particle Extinction and Scattering) were used as prototypical NP. Cells were treated with AgNP alone or in combination with classical immune stimuli (i.e. LPS, PHA, PWM) and cytokine assessed; in addition, CD54 and CD86 expression was evaluated in THP-1 cells. AgNP alone induced dose-related IL-8 production in all models, with higher response observed in THP-1 cells, possibly connected to different protein corona formation in bovine versus human serum. AgNP potentiated LPS-induced IL-8 and TNF-α, but not LPS-induced IL-10. AgNP alone induced slight increase in IL-4, and no change in IFN-γ production. While responses to PHA in term of IL-4 and IFN-γ production were not affected, increased PWM-induced IL-4 and IFN-γ production were observed, suggesting potentiation of humoral response. Reduction in PHA-induced IL-10 was observed. Overall, results indicate immunostimulatory effects. THP-1 cells work as well as primary cells, representing a useful and practical alternative, with the awareness that from a physiological point of view the whole blood assay is the one that comes closest to reality. Copyright © 2018 Elsevier Ltd. All rights reserved.

Rejection of syngeneic colon carcinoma by CTLs expressing single-chain antibody receptors codelivering CD28 costimulation.

PubMed

Haynes, Nicole M; Trapani, Joseph A; Teng, Michele W L; Jackson, Jacob T; Cerruti, Loretta; Jane, Stephen M; Kershaw, Michael H; Smyth, Mark J; Darcy, Phillip K

2002-11-15

A new strategy to improve the therapeutic utility of redirected T cells for cancer involves the development of novel Ag-specific chimeric receptors capable of stimulating optimal and sustained T cell antitumor activity in vivo. Given that T cells require both primary and costimulatory signals for optimal activation and that many tumors do not express critical costimulatory ligands, modified single-chain Ab receptors have been engineered to codeliver CD28 costimulation. In this study, we have compared the antitumor potency of primary T lymphocytes expressing carcinoembryonic Ag (CEA)-reactive chimeric receptors that incorporate either TCR-zeta or CD28/TCR-zeta signaling. Although both receptor-transduced T cell effector populations demonstrated cytolysis of CEA(+) tumors in vitro, T cells expressing the single-chain variable fragment of Ig (scFv)-CD28-zeta chimera had a far greater capacity to control the growth of CEA(+) xenogeneic and syngeneic colon carcinomas in vivo. The observed enhanced antitumor activity of T cells expressing the scFv-CD28-zeta receptor was critically dependent on perforin and the production of IFN-gamma. Overall, this study has illustrated the ability of a chimeric scFv receptor capable of harnessing the signaling machinery of both TCR-zeta and CD28 to augment T cell immunity against tumors that have lost expression of both MHC/peptide and costimulatory ligands in vivo.

Selective voltammetric determination of Cd(II) by using N,S-codoped porous carbon nanofibers.

PubMed

Gao, Sanshuang; Liu, Jing; Luo, Jun; Mamat, Xamxikamar; Sambasivam, Sangaraju; Li, Yongtao; Hu, Xun; Wågberg, Thomas; Hu, Guangzhi

2018-05-05

Porous carbon nanofibers codoped with nitrogen and sulfur (NFs) were prepared by pyrolysis of trithiocyanuric acid, silica nanospheres and polyacrylonitrile (PAN) followed by electrospinning. The NFs were used to modify a glassy carbon electrode (GCE) which then displayed highly sensitive response to traces of Cd(II). Compared to a bare GCE and a Nafion modified GCE, the GCE modified with codoped NFs shows improved sensitivity for Cd(II) in differential pulse anodic sweep voltammetry. The stripping peak current (typically measured at 0.81 V vs. Ag/AgCl) increases linearly in the 2.0-500 μg·L -1 Cd(II) concentration range. This is attributed to the large surface area (109 m 2 ·g -1 ), porous structure, and high fraction of heteroatoms (19 at.% of N and 0.75 at.% of S). The method was applied to the determination of Cd(II) in (spiked) tap water where it gave recoveries that ranged between 96% and 103%. Graphical abstract Schematic of a glassy carbon electrode (GCE) modified with N- and S-codoped porous carbon nanofibers (N,S-PCNFs). This GCE has good selectivity for cadmium ion (Cd 2+ ) which can be determined by differential pulse anodic sweeping voltammetry (DPASV) with a detection limit as low as 0.7 ng·mL -1 .

Preserved entropy and fragile magnetism

DOE PAGES

Canfield, Paul C.; Bud’ko, Sergey L.

2016-07-05

Here, a large swath of quantum critical and strongly correlated electron systems can be associated with the phenomena of preserved entropy and fragile magnetism. In this overview we present our thoughts and plans for the discovery and development of lanthanide and transition metal based, strongly correlated systems that are revealed by suppressed, fragile magnetism, quantum criticality, or grow out of preserved entropy. We will present and discuss current examples such as YbBiPt, YbAgGe, YbFe 2Zn 20, PrAg 2In, BaFe 2As 2, CaFe 2As 2, LaCrSb 3 and LaCrGe 3 as part of our motivation and to provide illustrative examples.

Role of Phragmites australis (common reed) for heavy metals phytoremediation of estuarine sediments.

PubMed

Cicero-Fernández, Diego; Peña-Fernández, Manuel; Expósito-Camargo, Jose A; Antizar-Ladislao, Blanca

2016-01-01

The ability of Phragmites australis to take up heavy metals (Co, Ni, Mo, Cd, Pb, Cr, Cu, Fe, Mn, Zn, and Hg) and other trace elements (As, Se, Ba), from estuarine sediments was investigated using a pilot plant experimental approach. Bioaccumulation (BCF) and translocation factors (TF) were calculated in vegetative and senescence periods for two populations of P. australis, from contaminated (MIC) and non-contaminated (GAL) estuarine sediments, respectively, both growing in estuarine contaminated sediment (RIA) from ría del Carmen y Boo, Santander Bay, Spain. The highest BCF values were obtained for Ni (0.43), Ba (0.43) Mo (0.36), Cr (0.35), and Cd (0.31) for plants collected from site GAL following the senescence period. The highest BCF values recorded for plants collected from MIC following the senescence period were for Mo (0.22) and Cu (0.22). Following senescence, plants collected from GAL and MIC presented TF>1 for Ni, Mo, Se, and Zn, and in addition plants collected from MIC presented TF>1 for Ba, Cr, and Mn. A substantial increase of Micedo's rhizosphere, six times higher than Galizano's rhizosphere, suggested adaptation to contaminated sediment. The evaluated communities of P. australis demonstrated their suitability for phytoremediation of heavy metals contaminated estuarine sediments.

Predictive value of serum ALT and T-cell receptor beta variable chain for HBeAg seroconversion in chronic hepatitis B patients during tenofovir treatment.

PubMed

Yang, Jiezuan; Yan, Dong; Guo, Renyong; Chen, Jiajia; Li, Yongtao; Fan, Jun; Fu, Xuyan; Yao, Xinsheng; Diao, Hongyan; Li, Lanjuan

2017-03-01

Effective antiviral therapy plays a key role in slowing the progression of chronic hepatitis B (CHB). Identification of serum indices, including hepatitis B e antigen (HBeAg) expression and seroconversion, will facilitate evaluation of the efficacy of antiviral therapy in HBeAg-positive CHB patients. The biochemical, serological, virological parameters, and the frequency of circulating CD4CD25 regulatory T cell (Treg) in 32 patients were measured at baseline and every 12 weeks during 96 weeks of tenofovir disoproxil fumarate (TDF) treatment. The relationship between the hepatitis B virus (HBV) deoxyribonucleic acid (DNA) and Treg and alanine aminotransferase (ALT) levels was analyzed, respectively. The molecular profiles of T-cell receptor beta variable chain (TRBV) were determined using gene melting spectral pattern. For the seroconverted 12 patients, ALT declined to normal levels by week 24 and remained at this level in subsequent treatment; moreover, the predictive cutoff value of ALT for HBeAg seroconversion (SC) was 41.5 U/L at week 24. The positive correlation between HBV DNA and Treg and ALT was significant in SC patients, but not in non-SC patients. Six TRBV families (BV3, BV11, BV12, BV14, BV20, and BV24) were predominantly expressed in SC patients at baseline. The decline of ALT could be used to predict HBeAg seroconversion for CHB patients during TDF treatment. In addition, the profile of Tregs and TRBVs may be associated with HBeAg seroconversion and could also be a potential indicator for predicting HBeAg SC and treatment outcome for CHB patients.

Evaluation of screening and treatment of cryptococcal antigenaemia among HIV-infected persons in Soweto, South Africa.

PubMed

Govender, N P; Roy, M; Mendes, J F; Zulu, T G; Chiller, T M; Karstaedt, A S

2015-09-01

We retrospectively evaluated clinic-based screening to determine the prevalence of cryptococcal antigenaemia and management and outcome of patients with antigenaemia. Cryptococcal antigen (CrAg) screening of HIV-infected adults who attended the HIV clinic at Chris Hani Baragwanath Hospital was conducted over 19 months. Data collected from CrAg-positive patients included CD4 T-lymphocyte count at screening, prior or subsequent cryptococcal meningitis (CM), antifungal and antiretroviral treatment and outcome after at least 8 months. Of 1460 patients with no prior CM, 30 (2.1%) had a positive CrAg test. The prevalence of antigenaemia among patients with a CD4 count < 100 cells/μl and no prior CM was 2.8% (20 of 708). Of 29 evaluable CrAg-positive patients with no prior CM, 14 (48%) did not return for post-screening follow-up. Of these 14, five developed CM and one (7%) was known to be alive at follow-up. Of 15 patients who returned for follow-up, two already had evidence of nonmeningeal cryptococcosis. Overall, 11 received fluconazole, one did not and fluconazole treatment was unknown for three. Among these 15, one developed CM and 10 (67%) were known to be alive at follow-up. Overall, 18 (62%) of 29 CrAg-positive patients died or were lost to follow-up. Seven (0.5%) of 1430 CrAg-negative patients developed CM a median of 83 days post-screening (range 34 to 219 days). Loss to follow-up is the major operational issue relevant to scale-up of screen-and-treat. Patient outcomes may be improved by rapid access to CrAg results and focus on linkage to and retention in HIV care. © 2015 British HIV Association.

Differential relationships between set-shifting abilities and dimensions of insight in schizophrenia.

PubMed

Diez-Martin, J; Moreno-Ortega, M; Bagney, A; Rodriguez-Jimenez, R; Padilla-Torres, D; Sanchez-Morla, E M; Santos, J L; Palomo, T; Jimenez-Arriero, M A

2014-01-01

To assess insight in a large sample of patients with schizophrenia and to study its relationship with set shifting as an executive function. The insight of a sample of 161 clinically stable, community-dwelling patients with schizophrenia was evaluated by means of the Scale to Assess Unawareness of Mental Disorder (SUMD). Set shifting was measured using the Trail-Making Test time required to complete part B minus the time required to complete part A (TMT B-A). Linear regression analyses were performed to investigate the relationships of TMT B-A with different dimensions of general insight. Regression analyses revealed a significant association between TMT B-A and two of the SUMD general components: 'awareness of mental disorder' and 'awareness of the efficacy of treatment'. The 'awareness of social consequences' component was not significantly associated with set shifting. Our results show a significant relation between set shifting and insight, but not in the same manner for the different components of the SUMD general score. Copyright © 2013 S. Karger AG, Basel.

Genetic targeting of the active transcription factor XBP1s to dendritic cells potentiates vaccine-induced prophylactic and therapeutic antitumor immunity.

PubMed

Tian, Shenghe; Liu, Zuqiang; Donahue, Cara; Falo, Louis D; You, Zhaoyang

2012-02-01

In vivo dendritic cells (DC) targeting is an attractive approach with potential advantages in vaccine efficacy, cost, and availability. Identification of molecular adjuvants to in vivo "modulate " DC to coordinately render improved Th1 and CD8 T cell immunity, and attenuated deleterious Treg effects, is a critical challenge. Here, we report that in vivo genetic targeting of the active transcription factor XBP1s to DC (XBP1s/DC) potentiated vaccine-induced prophylactic and therapeutic antitumor immunity in multiple tumor models. This immunization strategy is based on a genetic vaccine encoding both cytomegalovirus (CMV)-driven vaccine Aghsp70 and DC-specific CD11c-driven XBP1s. The novel targeted vaccine induced durable Th1 and CD8 T cell responses to poorly immunogenic self/tumor antigen (Ag) and attenuated tumor-associated Treg suppressive function. Bone marrow (BM)-derived DC genetically modified to simultaneously overexpress XBP1s and express Aghsp70 upregulated CD40, CD70, CD86, interleukin (IL)-15, IL-15Rα, and CCR7 expression, and increased IL-6, IL-12, and tumor necrosis factor (TNF)-α production in vitro. XBP1s/DC elevated functional DEC205(+)CD8α(+)DC in the draining lymph nodes (DLN). The data suggest a novel role for XBP1s in modulating DC to potentiate tumor vaccine efficacy via overcoming two major obstacles to tumor vaccines (i.e., T cell hyporesponsiveness against poorly immunologic self/tumor Ag and tumor-associated Treg-mediated suppression) and improving DEC205(+)CD8α(+)DC.

Programmed death 1-mediated T cell exhaustion during visceral leishmaniasis impairs phagocyte function.

PubMed

Esch, Kevin J; Juelsgaard, Rachel; Martinez, Pedro A; Jones, Douglas E; Petersen, Christine A

2013-12-01

Control of Leishmania infantum infection is dependent upon Th1 CD4(+) T cells to promote macrophage intracellular clearance of parasites. Deficient CD4(+) T cell effector responses during clinical visceral leishmaniasis (VL) are associated with elevated production of IL-10. In the primary domestic reservoir of VL, dogs, we define occurrence of both CD4(+) and CD8(+) T cell exhaustion as a significant stepwise loss of Ag-specific proliferation and IFN-γ production, corresponding to increasing VL symptoms. Exhaustion was associated with a 4-fold increase in the population of T cells with surface expression of programmed death 1 (PD-1) between control and symptomatic populations. Importantly, exhausted populations of CD8(+) T cells and to a lesser extent CD4(+) T cells were present prior to onset of clinical VL. VL-exhausted T cells did not undergo significant apoptosis ex vivo after Ag stimulation. Ab block of PD-1 ligand, B7.H1, promoted return of CD4(+) and CD8(+) T cell function and dramatically increased reactive oxygen species production in cocultured monocyte-derived phagocytes. As a result, these phagocytes had decreased parasite load. To our knowledge, we demonstrate for the first time that pan-T cell, PD-1-mediated, exhaustion during VL influenced macrophage-reactive oxygen intermediate production. Blockade of the PD-1 pathway improved the ability of phagocytes isolated from dogs presenting with clinical VL to clear intracellular parasites. T cell exhaustion during symptomatic canine leishmaniasis has implications for the response to vaccination and therapeutic strategies for control of Leishmania infantum in this important reservoir species.

Electronic spectrum of non-tetrahedral acceptors in CdTe:Cl and CdTe:Bi,Cl single crystals

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

Krivobok, V. S., E-mail: krivobok@lebedev.ru; Moscow Institute of Physics and Technology; Nikolaev, S. N.

2016-02-07

The electronic spectra of complex acceptors in compensated CdTe:Cl, CdTe:Ag,Cl, and CdTe:Bi,Cl single crystals are studied using low-temperature photoluminescence (PL) measurements under both nonresonant and resonant excitation of distant donor–acceptor pairs (DAP). The wavelength modulation of the excitation source combined with the analysis of the differential PL signal is used to enhance narrow spectral features obscured because of inhomogeneous line broadening and/or excitation transfer for selectively excited DAPs. For the well-known tetrahedral (T{sub D}) Ag{sub Cd} acceptor, the energies of four excited states are measured, and the values obtained are shown to be in perfect agreement with the previous data.more » Moreover, splitting between the 2P{sub 3/2} (Γ{sub 8}) and 2S{sub 3/2} (Γ{sub 8}) states is clearly observed for Ag{sub Cd} centers located at a short distance (5–7 nm) from a hydrogen-like donor (Cl{sub Te}). This splitting results from the reduction of the T{sub D} symmetry taking place when the acceptor is a member of a donor–acceptor pair. For the Cl-related complex acceptor with an activation energy of ∼121 meV (A-center), the energies of eight excited states are measured. It is shown that this defect produces low-symmetry central-cell correction responsible for the strong splitting of S-like T{sub D} shells. The energy spectrum of the Bi-related shallow acceptor with an activation energy of ∼36 meV is measured as well. The spectrum obtained differs drastically from the hydrogen-like set of levels, which indicates the existence of repulsive low-symmetry perturbation of the hydrogen-like Coulomb potential. It is also shown that the spectra of selectively excited PL recorded for a macroscopic ensemble of distant donor–acceptor pairs allow one to detect the low symmetry of acceptors of a given type caused by their complex nature or by the Jahn–Teller distortion. This method does not require any additional (external) field and is applicable to acceptors in diverse zinc-blende compound semiconductors.« less

Characterization of Y1-xCaxBa2Cu4O8 (x=0.0˜ 0.1) with Double Cu-O Chains by Raman Spectra

NASA Astrophysics Data System (ADS)

Kodama, Yasuharu; Tanemura, Sakae; Ikeda, Teruki

1991-08-01

Raman spectra of Y1-xCaxBa2Cu4O8 (x=0.0, 0.02, 0.05 and 0.1) ceramic samples synthesized under high oxygen pressure were investigated. Seven clear peaks assigned to Ag modes were observed for the sample with x=0. With increasing x, the peaks at 238 cm-1, 332 cm-1, 430 cm-1 and 590 cm-1 were broadened. The origin of the broadening of the peaks at 238 cm-1 and 590 cm-1 is considered to be the destruction of the double Cu-O chains due to the substitution of Ca for Y.

Targeting glutamine metabolism in myeloproliferative neoplasms

PubMed Central

Zhan, Huichun; Ciano, Kristen; Dong, Katherine; Zucker, Stanley

2016-01-01

JAK2V617F mutation can be detected in the majority of myeloproliferative neoplasm (MPN) patients. The JAK2 inhibitor Ruxolitinib is the first FDA-approved treatment for MPNs. However, its use is limited by various dose related toxicities. Here, we studied the metabolic state and glutamine metabolism of BaF3-hEPOR-JAK2V617F and BaF3-hEPOR-JAK2WT cells. We found that the JAK2V617F-mutant cells were associated with increased oxygen consumption rate and extracellular acidification rate than the JAK2WT cells and there was an increased glutamine metabolism in JAK2V617F-mutant cells compared to wild-type cells. Glutaminase (GLS), the key enzyme in gluta-mine metabolism, was upregulated in the JAK2V617F-mutant BaF3 cells compared to the JAK2WT BaF3 cells. In MPN patient peripheral blood CD34+ cells, GLS expression was increased in JAK2V617F-mutant progenitor cells compared to JAK2 wild-type progenitor cells from the same patients and GLS levels were increased at the time of disease progression compared to at earlier time points. Moreover, GLS inhibitor increased the growth inhibitory effect of Ruxolitinib in both JAK2V617F-mutant cell lines and peripheral blood CD34+ cells from MPN patients. Therefore, GLS inhibitor should be further explored to enhance the therapeutic effectiveness of JAK2 inhibitor and allow the administration of lower doses of the drug to avoid its toxicity. PMID:26227854

Spectroscopic exploration of interaction between PEG-functionalized Ag2S nanoparticles with bovine serum albumin

NASA Astrophysics Data System (ADS)

Prasanth, S.; RitheshRaj, D.; Vineeshkumar, T. V.; Sudarsanakumar, C.

2018-05-01

The introduction of nanoparticles into biological fluids often leads to the formation of biocorona over the surface of nanoparticles. For the effective use of nanoparticles in biological applications it is very essential to understand their interactions with proteins. Herein, we investigated the interactions of Poly ethylene glycol capped Ag2S nanoparticles with Bovine Serum Albumin by spectroscopic techniques. By the addition of Ag2S nanoparticles, a ground state complex is formed. The CD spectroscopy reveals that the secondary structure of BSA is altered by complexation with PEG-Ag2S nanoparticles, while the overall tertiary structure remains closer to that of native BSA.

Epidemiological and clinical characteristics of hepatitis B virus in HIV-infected patients in Guangdong, China.

PubMed

Huang, S M; Cai, W P; Hu, F Y; Lan, Y; Liao, B L; Chen, Y P; Tang, X P

2016-09-01

This study investigated the epidemiological and clinical characteristics of hepatitis B virus (HBV) in HIV-infected adults at the time of antiretroviral therapy (ART) initiation in Guangdong province, China. A total of 2793 HIV-infected adults were enrolled between January 2004 and September 2011. Demographic data and laboratory parameters were collected, HBV-DNA levels were measured, and HBV genotypes were identified before ART initiation. The prevalence of hepatitis B surface antigen (HBsAg) in HIV-infected patients was 13.2%. A total of 266 HIV/HBV co-infected patients and 1469 HIV mono-infected patients were recruited. The median alanine aminotransferase and aspartate aminotransferase levels of HIV/HBV co-infected patients were higher than HIV mono-infected patients (32 U/L vs. 22 U/L, p < 0.001 and 35 U/L vs. 24 U/L, p < 0.001, respectively), whereas the median CD4 cell count of HIV/HBV co-infected patients was lower than HIV mono-infected patients (59 cells/mm(3) vs. 141 cells/mm(3), p < 0.001). The level of CD4 cell count was lower in hepatitis B e-antigen (HBeAg)-positive co-infected patients than HBeAg-negative patients (36 cells/mm(3) vs. 69 cells/mm(3), p = 0.014). A similar result was found in high level of HBV-DNA and low level of HBV-DNA groups (33 cells/mm(3) vs. 89 cells/mm(3), p < 0.001). HBV genotypes were classified as genotypes B and C. Patients infected with genotypes B and C differed significantly in terms of proportion of those who were HBeAg-positive (40.5% vs. 62.2%, p = 0.014). This study indicates a high prevalence of HBsAg in HIV-infected adults in Guangdong. The level of CD4 cell count in HIV/HBV co-infected patients was much lower than HIV mono-infected patients, especially in patients who were HBeAg-positive and had a high level of HBV-DNA. The predominant HBV genotype in HIV/HBV co-infected patients is genotype B. © The Author(s) 2015.

Sediment pollution in margins of the Lake Guaíba, Southern Brazil.

PubMed

de Andrade, Leonardo Capeleto; Tiecher, Tales; de Oliveira, Jessica Souza; Andreazza, Robson; Inda, Alberto Vasconcellos; de Oliveira Camargo, Flávio Anastácio

2017-12-02

Sediments are formed by deposition of organic and inorganic particles on depth of water bodies, being an important role in aquatic ecosystems, including destination and potential source of essential nutrients and heavy metals, which may be toxic for living organisms. The Lake Guaíba supplies water for approximately two million people and it is located in the metropolitan region of Porto Alegre, Rio Grande do Sul State, Brazil. Thus, the aim of this study was to evaluate the sediment pollution in the margins of Lake Guaíba in the vicinity of Porto Alegre city. Surface sediment was sampled in 12 sites to assess the concentration of several elements (C, N, P, Fe, Al, Ca, Mg, Na, K, Mn, Ba, Zn, V, Pb, Cu, Cr, Ni, Cd, Mo, and Se) and the mineralogical composition. Sediment in margins of Lake Guaíba presented predominantly (> 95%) sandy fraction in all samples, but with significant differences between evaluated sites. Sediments in the margins of Lake Guaíba showed indications of punctual water pollution with Pb, Cu, Cr, Ni, TOC, TKN, and P, mainly derived from urban streams that flow into the lake. In order to solve these environmental liabilities, public actions should not focus only on Guaíba, but also in the streams that flow into the lake.

Filarial infection modulates the immune response to Mycobacterium tuberculosis through expansion of CD4+ IL-4 memory T cells

PubMed Central

Chatterjee, Soumya; Clark, Carolyn E.; Lugli, Enrico; Roederer, Mario; Nutman, Thomas B.

2015-01-01

Exaggerated CD4+T helper 2-specific cytokine producing memory T cell responses developing concomitantly with a T helper1 response might have a detrimental role in immunity to infection caused by Mycobacterium tuberculosis (Mtb). To assess the dynamics of antigen (Ag)-specific memory T cell compartments in the context of filarial infection we used multiparameter flow cytometry on PBMCs from 25 microfilaremic filarial -infected (Inf) and 14 filarial-uninfected (Uninf) subjects following stimulation with filarial (BmA) or with the Mycobacterium tuberculosis (Mtb)-specific Ag CFP10. Our data demonstrated that the Inf group not only had a marked increase in BmA-specific CD4+IL-4+ cells (Median net frequency compared to baseline (Fo)=0.09% vs. 0.01%, p=0.038) but also to CFP10 (Fo =0.16% vs. 0.007%, p=0.04) and Staphylococcal Enterotoxin B (SEB) (Fo =0.49% vs. 0.26%, p=0.04). The Inf subjects showed a BmA-specific expansion of CD4+CD45RO+IL-4+ producing central memory (TCM, CD45RO+CCR7+CD27+) (Fo =1.1% vs. 0.5%, p=0.04) as well as effector memory (TEM CD45RO+CCR7-CD27-) (Fo =1.5% vs. 0.2%, p=0.03) with a similar but non-significant response to CFP10. In addition, there was expansion of CD4+ IL-4+ CD45RA+ CCR7+CD27+ (naïve-like) in Inf individuals compared to Uninf subjects. Among Inf subjects with definitive latent tuberculosis , there were no differences in frequencies of IL-4 producing cells within any of the memory compartments compared to the Uninf group. Our data suggest that filarial infection induces antigen-specific, exaggerated IL-4 responses in distinct T cell memory compartments to Mtb-specific antigens, which are attenuated in subjects who are able to mount a delayed type hypersensitivity reaction to Mtb. PMID:25667413

Bio-functionalized silver nanoparticles for selective colorimetric sensing of toxic metal ions and antimicrobial studies

NASA Astrophysics Data System (ADS)

Vinod Kumar, V.; Anbarasan, S.; Christena, Lawrence Rene; SaiSubramanian, Nagarajan; Philip Anthony, Savarimuthu

2014-08-01

Hibiscus Sabdariffa (Gongura) plant extracts (leaves (HL) and stem (HS) were used for the first time in the green synthesis of bio-functionalized silver nanoparticles (AgNPs). The bio-functionality of AgNPs has been successfully utilized for selective colorimetric sensing of potentially health and environmentally hazardous Hg2+, Cd2+ and Pb2+ metal ions at ppm level in aqueous solution. Importantly, clearly distinguishable colour for all three metal ions was observed. The influence of extract preparation condition and pH were also explored on the formation of AgNPs. Both selectivity and sensitivity differed for AgNPs synthesized from different parts of the plant. Direct correlation between the stability of green synthesized AgNPs at different pH and its antibacterial effects has been established. The selective colorimetric sensing of toxic metal ions and antimicrobial effect of green synthesized AgNPs demonstrated the multifunctional applications of green nanotechnology.

Vaccination with poly(D,L-lactide-co-glycolide) nanoparticles loaded with soluble Leishmania antigens and modified with a TNFα-mimicking peptide or monophosphoryl lipid A confers protection against experimental visceral leishmaniasis

PubMed Central

Margaroni, Maritsa; Agallou, Maria; Athanasiou, Evita; Kammona, Olga; Kiparissides, Costas; Gaitanaki, Catherine; Karagouni, Evdokia

2017-01-01

Visceral leishmaniasis (VL) persists as a major public health problem, and since the existing chemotherapy is far from satisfactory, development of an effective vaccine emerges as the most appropriate strategy for confronting VL. The development of an effective vaccine relies on the selection of the appropriate antigen and also the right adjuvant and/or delivery vehicle. In the present study, the protective efficacy of poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles (NPs), which were surface-modified with a TNFα-mimicking eight-amino-acid peptide (p8) and further functionalized by encapsulating soluble Leishmania infantum antigens (sLiAg) and monophosphoryl lipid A (MPLA), a TLR4 ligand, was evaluated against challenge with L. infantum parasites in BALB/c mice. Vaccination with these multifunctionalized PLGA nanoformulations conferred significant protection against parasite infection in vaccinated mice. In particular, vaccination with PLGA-sLiAg-MPLA or p8-PLGA-sLiAg NPs resulted in almost complete elimination of the parasite in the spleen for up to 4 months post-challenge. Parasite burden reduction was accompanied by antigen-specific humoral and cellular immune responses. Specifically, injection with PLGA-sLiAg-MPLA raised exclusively anti-sLiAg IgG1 antibodies post-vaccination, while in p8-PLGA-sLiAg-vaccinated mice, no antibody production was detected. However, 4 months post-challenge, in mice vaccinated with all the multifunctionalized NPs, antibody class switching towards IgG2a subtype was observed. The study of cellular immune responses revealed the increased proliferation capacity of spleen cells against sLiAg, consisting of IFNγ-producing CD4+ and CD8+ T cells. Importantly, the activation of CD8+ T cells was exclusively attributed to vaccination with PLGA NPs surface-modified with the p8 peptide. Moreover, characterization of cytokine production in vaccinated–infected mice revealed that protection was accompanied by significant increase of IFNγ and lower levels of IL-4 and IL-10 in protected mice when compared to control infected group. Conclusively, the above nanoformulations hold promise for future vaccination strategies against VL. PMID:28883727

Long-term Geochemical Evolution of Lithogenic Versus Anthropogenic Distribution of Macro and Trace Elements in Household Attic Dust.

PubMed

Balabanova, Biljana; Stafilov, Trajče; Šajn, Robert; Tănăselia, Claudiu

2017-01-01

Attic dusts were examined as historical archives of anthropogenic emissions, with the goal of elucidating the enrichment pathways associated with hydrothermal exploitation of Cu, Pb, and Zn minerals in the Bregalnica River basin in the eastern part of the Republic of Macedonia. Dust samples were collected from 84 settlements. Atomic emission spectrometry and mass spectrometry with inductively coupled plasma were applied as analytical techniques for the determination of 69 element contents. Multivariate analysis was applied for the extraction of dominant geochemical markers. The lithogenic distribution was simplified to six dominant geochemical markers: F1: Ga-Nb-Ta-Y-(La-Gd)-(Eu-Lu); F2: Be-Cr-Li-Mg-Ni; F3: Ag-Bi-Cd-Cu-In-Mn-Pb-Sb-Te-W-Zn; F4: Ba-Cs-Hf-Pd-Rb-Sr-Tl-Zr; F5: As-Co-Ge-V; and F6: К-Na-Sc-Ti. The anthropogenic effects on the air pollution were marked by a dominance of F3 and secondary dominance of F5. The fifth factor also was determined as a lithogenic marker for the occurrence of the very old Rifeous shales. The first factor also presents a very unique association that despite the heterogeneity relays on natural phenomena of tracking the deposition in areas of Proterosoic gneisses; related to the distribution of fine particles was associated with carbonate-silicate volcanic rocks. Intensive poly-metallic dust depositions were recorded only in the surroundings of localities where the hydrothermal extractions are implemented. Long-term deposition can be considered as pollution indexes for these hot spots. This mainly affects the Cd, Pb, and Zn deposition that is as high as 25, 3900, and 3200 mg/kg, respectively.

Emission sources estimation of size-segregated suburban aerosols measured in continental part of Balkan region using PMF5.0 multivariate receptor model

NASA Astrophysics Data System (ADS)

Petrovic, Srdjan; Đuričić-Milanković, Jelena; Anđelković, Ivan; Pantelić, Ana; Gambaro, Andrea; Đorđević, Dragana

2017-04-01

Using Low-Pressure Cascade Impactors by Dr Berner size segregated particulate matter in the size ranges: 0.27 ≤ Dp ≤ 0.53 μm, 0.53 ≤ Dp ≤ 1.06 μm, 1.06 ≤ Dp ≤ 2.09 μm, 2.09 ≤ Dp ≤ 4.11 μm, 4.11 ≤ Dp ≤ 8.11 μm and 8.11 ≤ Dp ≤ 16 μm were collected. Forty-eight-hour size segregated particulate matter samples from atmospheric aerosols in the sub-urban site of Belgrade were measured during two years (in 2012th to 2013in). ICP-MS was used to quantify next elements: Ag, Al, As, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Hg, Na, Ni, Mg, Mn, Mo, Pb, Se, Sb, Ti, Tl, V and Zn. In order to examine the number of sources and their fingerprints, EPA PMF 5.0 multivariate receptor tool was used. Error estimation methods (bootstrap, displacement, and bootstrap enhanced by displacement) in the analysis of the obtained solutions have enabled proper detection of the number and types of sources. This analysis of the results indicated the existence of four main sources that contribute to air pollution in the suburban area of Belgrade.

Biomonitoring of 37 trace elements in blood samples from inhabitants of northern Germany by ICP-MS.

PubMed

Heitland, Peter; Köster, Helmut D

2006-01-01

The trace elements Ag, As, Au, B, Ba, Be, Bi, Cd, Ce, Co, Cs, Cu, Ga, Hf, Hg, In, La, Mn, Mo, Ni, Pb, Pd, Rb, Rh, Ru, Sb, Se, Sn, Sr, Te, Th, Tl, U, V, W, Y and Zr were determined in 130 human blood samples from occupationally non-exposed volunteers living in the greater area of Bremen in northern Germany. The blood samples were collected in lithium heparin monovettes developed for trace metal determination and were analysed by inductively coupled plasma mass spectrometry (ICP-MS) with an octopole-based collision/reaction cell. For sample introduction into the ICP, the blood samples were diluted 1/10 (V/V) with a 0.1% Triton-X-100 and 0.5% (V/V) ammonia solution. The method validation of our developed routine method is described for all 37 elements and results about internal and external quality assurance are discussed. Information on exposure conditions of all human subjects were collected by questionnaire-based interviews, including smoking habits, seafood consumption and the type of dental alloys in the teeth. Mean values, geometric mean values, ranges and selected percentiles of all elemental concentrations in human blood are presented, which helps toxicologists and clinical chemists planning research about exposition to metals and health effects caused by exposition to metals.

Transfer parameters for ICRP's Reference Animals and Plants in a terrestrial Mediterranean ecosystem.

PubMed

Guillén, J; Beresford, N A; Baeza, A; Izquierdo, M; Wood, M D; Salas, A; Muñoz-Serrano, A; Corrales-Vázquez, J M; Muñoz-Muñoz, J G

2018-06-01

A system for the radiological protection of the environment (or wildlife) based on Reference Animals and Plants (RAPs) has been suggested by the International Commission on Radiological Protection (ICRP). To assess whole-body activity concentrations for RAPs and the resultant internal dose rates, transfer parameters are required. However, transfer values specifically for the taxonomic families defined for the RAPs are often sparse and furthermore can be extremely site dependent. There is also a considerable geographical bias within available transfer data, with few data for Mediterranean ecosystems. In the present work, stable element concentrations (I, Li, Be, B, Na, Mg, Al, P, S, K. Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, Cs, Ba, Tl, Pb and U) in terrestrial RAPs, and the corresponding whole-body concentration ratios, CR wo , were determined in two different Mediterranean ecosystems: a Pinewood and a Dehesa (grassland with disperse tree cover). The RAPs considered in the Pinewood ecosystem were Pine Tree and Wild Grass; whereas in the Dehesa ecosystem those considered were Deer, Rat, Earthworm, Bee, Frog, Duck and Wild Grass. The CR wo values estimated from these data are compared to those reported in international compilations and databases. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Investigation of drinking water quality in Kosovo.

PubMed

Berisha, Fatlume; Goessler, Walter

2013-01-01

In the recent years, not much environmental monitoring has been conducted in the territory of Kosovo. This study represents the first comprehensive monitoring of the drinking water situation throughout most of the territory of Kosovo. We present the distribution of major and minor trace elements in drinking water samples from Kosovo. During our study we collected 951 samples from four different sources: private-bored wells; naturally flowing artesian water; pumped-drilled wells; and public water sources (tap water). The randomly selected drinking water samples were investigated by routine water analyses using inductively coupled plasma mass spectrometry (ICPMS) for 32 elements (Li, Be, B, Na, Mg, Al, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Rb, Sr, Mo, Ag, Cd, Sn, Sb, Te, Ba, Tl, Pb, Bi, Th, U). Even though there are set guidelines for elemental exposure in drinking water worldwide, in developing countries, such as Kosovo, the lack of monitoring drinking water continues to be an important health concern. This study reports the concentrations of major and minor elements in the drinking water in Kosovo. Additionally, we show the variation of the metal concentration within different sources. Of the 15 regulated elements, the following five elements: Mn, Fe, Al, Ni, As, and U were the elements which most often exceeded the guidelines set by the EU and/or WHO.

Reuse of solid petroleum waste in the manufacture of porcelain stoneware tile.

PubMed

Pinheiro, B C A; Holanda, J N F

2013-03-30

This study investigates the incorporation of solid petroleum waste as raw material into a porcelain stoneware tile body, in replacement to natural kaolin material by up to 5 wt.%. Tile formulations containing solid petroleum waste were pressed and fired at 1240 °C by using a fast-firing cycle. The tile pieces were tested to determine their properties (linear shrinkage, water absorption, apparent density, and flexural strength), sintered microstructure, and leaching toxicity. The results therefore indicated that the growing addition of solid petroleum waste into tile formulations leads to a decrease of linear shrinkage, apparent density, and flexural strength, and to an increase of water absorption of the produced tile materials. It was also found that the replacement of kaolin with solid petroleum waste, in the range up to 2.5 wt.%, allows the production of porcelain stoneware tile (group BIa, ISO 13006 standard). All concentrations of Ag, As, Ba, Cd, Cr (total), Hg, and Pb of the fired porcelain stoneware tile pieces in the leachate comply with the current regulatory limits. These results indicate that the solid petroleum waste could be used for high-quality porcelain stoneware tile production, thus giving rise to a new possibility for an environmentally friendly management of this abundant waste. Copyright © 2013 Elsevier Ltd. All rights reserved.

Mechanistic insights into the effect of nanoparticles on zebrafish hatch.

PubMed

Ong, Kimberly Jessica; Zhao, Xinxin; Thistle, Maria E; Maccormack, Tyson J; Clark, Rhett J; Ma, Guibin; Martinez-Rubi, Yadienka; Simard, Benoit; Loo, Joachim Say Chye; Veinot, Jonathan G C; Goss, Greg G

2014-05-01

Aquatic organisms are susceptible to waterborne nanoparticles (NP) and there is only limited understanding of the mechanisms by which these emerging contaminants may affect biological processes. This study used silicon (nSi), cadmium selenide (nCdSe), silver (nAg) and zinc NPs (nZnO) as well as single-walled carbon nanotubes (SWCNT) to assess NP effects on zebrafish (Danio rerio) hatch. Exposure of 10 mg/L nAg and nCdSe delayed zebrafish hatch and 100 mg/L of nCdSe as well as 10 and 100 mg/L of uncoated nZnO completely inhibited hatch and the embryos died within the chorion. Both the morphology and the movement of the embryos were not affected, and it was determined that the main mechanism of hatch inhibition by NPs is likely through the interaction of NPs with the zebrafish hatching enzyme. Furthermore, it was concluded that the observed effects arose from the NPs themselves and not their dissolved metal components.

Structural and Solar Cell Properties of a Ag-Containing Cu2ZnSnS4 Thin Film Derived from Spray Pyrolysis.

PubMed

Nguyen, Thi Hiep; Kawaguchi, Takato; Chantana, Jakapan; Minemoto, Takashi; Harada, Takashi; Nakanishi, Shuji; Ikeda, Shigeru

2018-02-14

A silver (Ag)-incorporated kesterite Cu 2 ZnSnS 4 (CZTS) thin film was fabricated by a facile spray pyrolysis method. Crystallographic analyses indicated successful incorporation of various amounts of Ag up to a Ag/(Ag + Cu) ratio of ca. 0.1 into the crystal lattice of CZTS in a homogeneous manner without formation of other impurity compounds. From the results of morphological investigations, Ag-incorporated films had larger crystal grains than the CZTS film. The sample with a relatively low Ag content (Ag/(Ag + Cu) of ca. 0.02) had a compact morphology without appreciable voids and pinholes. However, an increase in the Ag content in the CZTS film (Ag/(Ag + Cu) ca. 0.10) induced the formation of a large number of pinholes. As can be expected from these morphological properties, the best sunlight conversion efficiency was obtained by the solar cell based on the film with Ag/(Ag + Cu) of ca. 0.02. Electrostructural analyses of the devices suggested that the Ag-incorporated film in the device achieved reduction in the amounts of unfavorable copper on zinc antisite defects compared to the bare CZTS film. Moreover, the use of a Ag-incorporated film improved band alignment at the CdS(buffer)-CZTS interface. These alterations should also contribute to enhancement of device properties.

Evaluated the Twenty-Six Elements in the Pectoral Muscle of As-Treated Chicken by Inductively Coupled Plasma Mass Spectrometry.

PubMed

Sun, Bonan; Xing, Mingwei

2016-02-01

This study assessed the impacts of dietary arsenic trioxide on the contents of 26 elements in the pectoral muscle of chicken. A total of 100 Hy-line laying cocks were randomly divided into two groups (n = 50), including an As-treated group (basic diet supplemented with arsenic trioxide at 30 mg/kg) and a control group (basal diet). The feeding experiment lasted for 90 days and the experimental animals were given free access to feed and drinking water. The elements lithium (Li), boron (B), natrum (Na), magnesium (Mg), aluminium (AI), silicium (Si), kalium (K), calcium (Ca), vanadium (V), chromium (Cr), manganese (Mn), ferrum (Fe), cobalt (Co.), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), selenium (Se), molybdenum (Mo), cadmium (Cd), stannum (Sn), stibium (Sb), barium (Ba), hydrargyrum (Hg), thallium (Tl) and plumbum (Pb) in the pectoral muscles were determined using inductively coupled plasma mass spectrometry (ICP-MS). The resulted data indicated that Li, Na, AI, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sn, Ba, Tl and Pb were significantly increased (P < 0.05) in chicken exposed to As2O3 compared to control chicken, while Mg, Si, K, As and Cd decreased significantly (P < 0.05). These results suggest that ICP-MS determination of elements in chicken tissues enables a rapid analysis with good precision and accuracy. Supplementation of high levels of As affected levels of 20 elements (Li, Na, AI, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sn, Ba, Tl, Pb, Mg, Si, K, As and Cd) in the pectoral muscles of chicken. Thus, it is needful to monitor the concentration of toxic metal (As) in chicken for human health.

Subcellular distributions of metals and metal induced stress: A field study

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

Jenkins, K.D.; Howe, S.; Sanders, B.M.

This paper reports the results of a field study which took place around an exploratory well located in the Santa Barbara Channel. This study was designed to test for significant temporal and spatial differences in the concentrations of a number of drilling fluid-associated metals in both the sediments and biota. Temporal changes in the distribution of Ba, Cd, Cr, Cu, Hg, Ni, Pb, and Zn were examined in the sediments, and the bioaccumulation and subcellular distribution of these metals were examined in three benthic invertebrate species before and after drilling. Statistically significant increases in the accumulation of several of themore » metals were found in the surface sediments down current from the site after drilling with Ba showing the most pronounced increase. Statistically significant increases in the bioaccumulation of Ba were also observed in two of the three species examined, Cyclocardia ventricosa and Pactinaria californiensis. Within these organisms the majority of the Ba was localized in the granular pellets (>97%) and less than 0.1% accumulated in the cytosol. These data indicate that although bioaccumulation of Ba occurs in some species immediately down current from the well, most of it remains in an insoluble for, presumably as BaSO{sub 4}.« less

Excitonic pathway to photoinduced magnetism in colloidal nanocrystals with nonmagnetic dopants

NASA Astrophysics Data System (ADS)

Pinchetti, Valerio; Di, Qiumei; Lorenzon, Monica; Camellini, Andrea; Fasoli, Mauro; Zavelani-Rossi, Margherita; Meinardi, Francesco; Zhang, Jiatao; Crooker, Scott A.; Brovelli, Sergio

2018-02-01

Electronic doping of colloidal semiconductor nanostructures holds promise for future device concepts in optoelectronic and spin-based technologies. Ag+ is an emerging electronic dopant in iii-v and ii-vi nanostructures, introducing intragap electronic states optically coupled to the host conduction band. With its full 4d shell Ag+ is nonmagnetic, and the dopant-related luminescence is ascribed to decay of the conduction-band electron following transfer of the photoexcited hole to Ag+. This optical activation process and the associated modification of the electronic configuration of Ag+ remain unclear. Here, we trace a comprehensive picture of the excitonic process in Ag-doped CdSe nanocrystals and demonstrate that, in contrast to expectations, capture of the photohole leads to conversion of Ag+ to paramagnetic Ag2+. The process of exciton recombination is thus inextricably tied to photoinduced magnetism. Accordingly, we observe strong optically activated magnetism and diluted magnetic semiconductor behaviour, demonstrating that optically switchable magnetic nanomaterials can be obtained by exploiting excitonic processes involving nonmagnetic impurities.

Long-term outcomes of children treated for Cushing's disease: a single center experience.

PubMed

Yordanova, Galina; Martin, Lee; Afshar, Farhad; Sabin, Ian; Alusi, Ghassan; Plowman, Nicholas P; Riddoch, Fiona; Evanson, Jane; Matson, Matthew; Grossman, Ashley B; Akker, Scott A; Monson, John P; Drake, William M; Savage, Martin O; Storr, Helen L

2016-12-01

Pediatric Cushing's disease (CD) is rare and there are limited data on the long-term outcomes. We assessed CD recurrence, body composition, pituitary function and psychiatric comorbidity in a cohort of pediatric CD patients. Retrospective review of 21 CD patients, mean age at diagnosis 12.1 years (5.7-17.8), managed in our center between 1986 and 2010. Mean follow-up from definitive treatment was 10.6 years (2.9-27.2). Fifteen patients were in remission following transsphenoidal surgery (TSS) and 5 were in remission following TSS + external pituitary radiotherapy (RT). One patient underwent bilateral adrenalectomy (BA). CD recurrence occurred in 3 (14.3 %) patients: 2 at 2 and 6 years after TSS and 1 7.6 years post-RT. The BA patient developed Nelson's syndrome requiring pituitary RT 0.6 years post-surgery. Short-term growth hormone deficiency (GHD) was present in 14 patients (81 % patients tested) (11 following TSS and 3 after RT) and 4 (44 % of tested) had long-term GHD. Gonadotropin deficiency caused impaired pubertal development in 9 patients (43 %), 4 requiring sex steroid replacement post-puberty. Four patients (19 %) had more than one pituitary hormone deficiency, 3 after TSS and 1 post-RT. Five patients (24 %) had long-term psychiatric co-morbidities (cognitive dysfunction or mood disturbance). There were significant long-term improvements in growth, weight and bone density but not complete reversal to normal in all patients. The long-term consequences of the diagnosis and treatment of CD in children is broadly similar to that seen in adults, with recurrence of CD after successful treatment uncommon but still seen. Pituitary hormone deficiencies occurred in the majority of patients after remission, and assessment and appropriate treatment of GHD is essential. However, while many parameters improve, some children may still have mild but persistent defects.

Dose-dependent immunogenicity of a soluble Neospora caninum tachyzoite-extract vaccine formulated with a soy lecithin/β-glucan adjuvant in cattle.

PubMed

Mansilla, F C; Czepluch, W; Malacari, D A; Hecker, Y P; Bucafusco, D; Franco-Mahecha, O L; Moore, D P; Capozzo, A V

2013-10-18

Mice immunized with a soluble extract of Neospora caninum tachyzoites (sNcAg) formulated with Providean-AVEC, an aqueous soy-based adjuvant, are fully protected from N. caninum multiplication. Here we evaluated the dose-dependent immunogenicity of this vaccine formulation in cattle. Cattle (N=3 per group) were immunized with two applications (30 days apart) of formulations containing Providean-AVEC and different payloads of sNcAg (100, 50 and 10 μg), that were five to fifty times lower than the only reported study using this same antigen in cattle. Kinetics and magnitude of the vaccine-induced immune responses were dose-dependent. Cattle immunized with 100 μg-sNcAg elicited high-avidity specific antibodies 3 weeks after the primary vaccination while those that received 50 μg of antigen had maximum levels of specific high-avidity antibodies 5 days after the day 30 boost. Vaccination with 10 μg of sNcAg induced comparable antibody responses after 2 weeks post re-vaccination. IgG1 was the predominant isotype in all vaccinated animals. Maximum systemic IFN-γ levels were measured in cattle immunized with 50 and 100 μg-sNcAg (14 ± 2.8 ng/ml). CD4(+)-T cells from vaccinated animals proliferated after sNcAg stimulation in vitro, producing IFN-γ. Recall IFN-γ responses mediated by CD4(+)-T cells were detected up to 140 days post vaccination. Formulations containing Providean-AVEC and 50 μg of sNcAg stimulated broad cellular and humoral immune responses against N. caninum in cattle. The profile and magnitude of the immune response elicited by this vaccine can be modified by the antigen-dose and vaccination schedule. This is the first dose-response study performed in cattle using sNcAg as antigen. Copyright © 2013 Elsevier B.V. All rights reserved.

Mineralogy, alteration patterns, geochemistry, and fluid properties of the Ag-Au epithermal deposit Nová Baňa, Slovakia

NASA Astrophysics Data System (ADS)

Majzlan, Juraj; Berkh, Khulan; Kiefer, Stefan; Koděra, Peter; Fallick, Anthony E.; Chovan, Martin; Bakos, František; Biroň, Adrián; Ferenc, Štefan; Lexa, Jaroslav

2018-02-01

In this contribution, we report new data on mineralogy, alteration patterns, geochemistry, fluid properties and source of fluids for the deposit Nová Baňa, one of the smaller epithermal deposits in the Middle Miocene Štiavnica andesite stratovolcano (Western Carpathians, Slovakia). Ore veins and the associated rocks were studied in samples from outcrops and old mines, grab samples, and bore holes from the central part of the deposit (ore structures Althandel, Jozef, Jakub, Vavrinec), northern part (Freischurf), SE part (Gupňa) and SW part (Šibeničný vrch). Pervasive hydrothermal alteration transformed the rock-forming minerals into a mixture of adularia and fine-grained quartz, with lesser amount of pyrite, Ti oxides and Fe oxides. This assemblage was further altered to omnipresent interstratified illite/smectite that was used in this study as a geothermometer, corroborating the results from the fluid inclusion work. Ore minerals comprise predominantly pyrite, sphalerite, galena but all sulfides are relatively sparse in the samples studied. Minerals of precious metals are electrum, Ag-tetrahedrite, acanthite, members of the polybasite-pearceite and pyrargyrite-proustite solid solution, and rare miargyrite, Hg-Ag tetrahedrite, and diaphorite. In the central part, we have found also some stibnite. In the SE part of the deposit, acanthite, uytenbogaardtite, and petrovskaite occur and seem to be related to supergene enrichment of the ores. In bulk ore samples, Zn usually dominates over Pb and Cu. The average Ag:Au ratio for the entire deposit is 64:1. The concentrations of precious metals in the grab samples reach maxima of 50 ppm Au and 570 ppm Ag in the SE part and 116 ppm Au and 1110 ppm Ag in the central part of the deposit. Fluid inclusions show signs of trapping of a heterogeneous fluid. In the central, northern and SE parts of the deposit, homogenization temperatures of 190-260 °C and consistently low salinities of <5 wt% NaCl eq were recorded. In the SW part, primary fluid inclusions gave homogenization temperatures of 160-180 °C and similar low salinities. The secondary inclusions, however, show salinities up to 24 wt% NaCl eq., interpreted as fluid boiling almost to dryness. Isotopic composition of quartz and clay minerals is recalculated to fluid composition of -5.6 to -0.6 ‰ δ18Ofluid and -80 to -36 ‰ δDfluid, indicating mixed character of hydrothermal fluids falling between the compositions of magmatic and meteoric waters, with predominance of meteoric waters. Assuming hydrostatic pressure in the fluids, the measured data suggest paleodepths of ore formation of 50-170 m in the SW part of the ore deposit, 130-420 m in the SE and N parts, and a range of 120-470 m for the central part. These observations, comparison with other epithermal deposits in the Central Slovak volcanic field, and additional data from published literature show that Nová Baňa is a low- to intermediate sulfidation epithermal deposit, genetically associated to late rhyolitic volcanic activity in this area.

Syntheses and structural characterization of vanado-tellurites and vanadyl-selenites: SrVTeO{sub 5}(OH), Cd{sub 2}V{sub 2}Te{sub 2}O{sub 11}, Ca{sub 3}VSe{sub 4}O{sub 13}·H{sub 2}O and Ba{sub 2}VSe{sub 3}O{sub 10}

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

Konatham, Satish; Vidyasagar, Kanamaluru, E-mail: kvsagar@iitm.ac.in

Four new quaternary vanado-tellurites and vanadyl-selenites, namely, SrVTeO{sub 5}(OH)(1), Cd{sub 2}V{sub 2}Te{sub 2}O{sub 11}(2), Ca{sub 3}VSe{sub 4}O{sub 13}·H{sub 2}O(3) and Ba{sub 2}VSe{sub 3}O{sub 10}(4) have been synthesized and structurally characterized by single crystal X-ray diffraction. The oxidation state of vanadium is +5 in tellurites 1 and 2 and +4 in selenites 3 and 4. The structures of SrVTeO{sub 5}(OH)(1) and Cd{sub 2}V{sub 2}Te{sub 2}O{sub 11}(2) compounds consist of (VTeO{sub 5}(OH)){sup 2-} and (V{sub 2}Te{sub 2}O{sub 11}){sup 4-}anionic chains respectively, which are built from tetrahedral VO{sub 4} and disphenoidal TeO{sub 4} moieties. Similarly the structures of Ca{sub 3}VSe{sub 4}O{sub 13}·H{sub 2}O(3)more » and Ba{sub 2}VSe{sub 3}O{sub 10}(4) respectively contain (VSe{sub 2}O{sub 7}){sup 2-} and (VSe{sub 3}O{sub 10}){sup 4-} anionic chains, which are made up of octahedral VO{sub 6} and pyramidal SeO{sub 3} units. Compounds 1 and 3 have been characterized by thermogravimetric and infrared spectroscopic methods. Compounds 1 and 2 are wide band gap semiconductors. - Graphical abstract: Ca{sub 3}VSe{sub 4}O{sub 13}·H{sub 2}O and Ba{sub 2}VSe{sub 3}O{sub 10} compounds contain (VSe{sub 2}O{sub 7}){sup 2-} and (VSe{sub 3}O{sub 10}){sup 4-} chains. - Highlights: • Four new vanado-tellurites and vanadyl-selenites are synthesized. • Their structural features are different. • The vanado-tellurites are wide band gap semiconductors.« less

Silver nanoclusters-assisted ion-exchange reaction with CdTe quantum dots for photoelectrochemical detection of adenosine by target-triggering multiple-cycle amplification strategy.

PubMed

Zhao, Yang; Tan, Lu; Gao, Xiaoshan; Jie, Guifen; Huang, Tingyu

2018-07-01

Herein, we successfully devised a novel photoelectrochemical (PEC) platform for ultrasensitive detection of adenosine by target-triggering cascade multiple cycle amplification based on the silver nanoparticles-assisted ion-exchange reaction with CdTe quantum dots (QDs). In the presence of target adenosine, DNA s1 is released from the aptamer and then hybridizes with hairpin DNA (HP1), which could initiate the cycling cleavage process under the reaction of nicking endonuclease. Then the product (DNA b) of cycle I could act as the "DNA trigger" of cycle II to further generate a large number of DNA s1, which again go back to cycle I, thus a cascade multiple DNA cycle amplification was carried out to produce abundant DNA c. These DNA c fragments with the cytosine (C)-rich loop were captured by magnetic beads, and numerous silver nanoclusters (Ag NCs) were synthesized by AgNO 3 and sodium borohydride. The dissolved AgNCs released numerous silver ions which could induce ion exchange reaction with the CdTe QDs, thus resulting in greatly amplified change of photocurrent for target detection. The detection linear range for adenosine was 1.0 fM ~10 nM with the detection limit of 0.5 fM. The present PEC strategy combining cascade multiple DNA cycle amplification and AgNCs-induced ion-exchange reaction with QDs provides new insight into rapid, and ultrasensitive PEC detection of different biomolecules, which showed great potential for detecting trace amounts in bioanalysis and clinical biomedicine. Copyright © 2018 Elsevier B.V. All rights reserved.

Antineoplastic Activity Comparison of Bovine Serum Albumin--Conjugated Sulfides Semiconductor Nanomaterials.

PubMed

Wang, Hua-Jie; Huang, Jing-Chun; Wu, Sha-Sha; Wang, Cai-Feng; Yu, Xue-Hong; Cao, Ying

2015-04-01

Although tumor is one of the most frequently occurring diseases and a leading cause of death, nanotechnology, one of the frontier sciences, is exhibiting its great potential to tumor treatments. The aim of this study was to design a facile and environmentally-friendly method to prepare bovine serum albumin-conjugated heavy metal sulfides nano-materials, including Ag2S, PbS and CdS. Here, bovine serum albumin was introduced in order to direct the synthesis of nano-materials by using its template effect and supply more sites for further modification in future. The crystal structure and morphology were analyzed by XRD and TEM, respectively. Additionally, the antineoplastic activity of nano-materials was compared by cell viability analysis, optical and electron microscopy observation after exposure of the human hepatoma cell line. The results showed that the inhibition effect of heavy metal sulfides on tumor cells was in the order of nano-PbS > bulk CdS > nano-Ag2S > nano-CdS > bulk PbS > bulk Ag2S. It could be concluded that heavy metal sulfides had significantly negative impact on human hepatoma cells growth but it could not be obviously generalized that nano-particles were always more effective to kill tumor cells than bulk materials. The size and surface reactivity might be the important factors causing the difference.

Soil quality assessment using GIS-based chemometric approach and pollution indices: Nakhlak mining district, Central Iran.

PubMed

Moore, Farid; Sheykhi, Vahideh; Salari, Mohammad; Bagheri, Adel

2016-04-01

This paper is a comprehensive assessment of the quality of soil in the Nakhlak mining district in Central Iran with special reference to potentially toxic metals. In this regard, an integrated approach involving geostatistical, correlation matrix, pollution indices, and chemical fractionation measurement is used to evaluate selected potentially toxic metals in soil samples. The fractionation of metals indicated a relatively high variability. Some metals (Mo, Ag, and Pb) showed important enrichment in the bioavailable fractions (i.e., exchangeable and carbonate), whereas the residual fraction mostly comprised Sb and Cr. The Cd, Zn, Co, Ni, Mo, Cu, and As were retained in Fe-Mn oxide and oxidizable fractions, suggesting that they may be released to the environment by changes in physicochemical conditions. The spatial variability patterns of 11 soil heavy metals (Ag, As, Cd, Co, Cr, Cu, Mo, Ni, Pb, Sb, and Zn) were identified and mapped. The results demonstrated that Ag, As, Cd, Mo, Cu, Pb, Sb, and Zn pollution are associated with mineralized veins and mining operations in this area. Further environmental monitoring and remedial actions are required for management of soil heavy metals in the study area. The present study not only enhanced our knowledge regarding soil pollution in the study area but also introduced a better technique to analyze pollution indices by multivariate geostatistical methods.

ITO/metal/ITO anode for efficient transparent white organic light-emitting diodes

NASA Astrophysics Data System (ADS)

Joo, Chul Woong; Lee, Jonghee; Sung, Woo Jin; Moon, Jaehyun; Cho, Nam Sung; Chu, Hye Yong; Lee, Jeong-Ik

2015-02-01

We report on the characteristics of enhanced and balanced white-light emission of transparent organic light emitting diodes (TOLEDs) by introducing anode that has a stack structure of ITO/metal/ITO (IMI). We have investigated an anode that has a stack structure of IMI. IMI anodes are typically composed of a thin Ag layer (˜15 nm) sandwiched between two ITO layers (˜50 nm). By inserting an Ag layer it was possible to achieve sheet resistance lower than 3 Ω/sq. and transmittance of 86% at a wavelength of 550 nm. The Ag insert can act as a reflective component. With its counterpart, a transparent cathode made of a thin Ag layer (˜15 nm), micro-cavities (MC) can be effectively induced in the OLED, leading to improved performance. Using an IMI anode, it was possible to significantly increase the current efficiencies. The current efficiencies of the top and the bottom of the IMI TOLED increased to 23.0 and 15.6 cd/A, respectively, while those of the white TOLED with the ITO anode were 20.7 and 5.1 cd/A, respectively. A 30% enhancement in the overall current efficiency was achieved by taking advantage of the MC effect and the low sheet resistance.

Protective dendritic cell responses against listeriosis induced by the short form of the deubiquitinating enzyme CYLD are inhibited by full-length CYLD.

PubMed

Wurm, Rebecca; Just, Sissy; Wang, Xu; Wex, Katharina; Schmid, Ursula; Blanchard, Nicolas; Waisman, Ari; Schild, Hans-Jörg; Deckert, Martina; Naumann, Michael; Schlüter, Dirk; Nishanth, Gopala

2015-05-01

The deubiquitinating enzyme CYLD is an important tumor suppressor and inhibitor of immune responses. In contrast to full-length CYLD, the immunological function of the naturally occurring short splice variant of CYLD (sCYLD) is insufficiently described. Previously, we showed that DCs, which lack full-length CYLD but express sCYLD, exhibit augmented NF-κB and DC activation. To explore the function of sCYLD in infection, we investigated whether DC-specific sCYLD regulates the pathogenesis of listeriosis. Upon Listeria monocytogenes infection of CD11c-Cre Cyld(ex7/8 fl/fl) mice, infection of CD8α(+) DCs, which are crucial for the establishment of listeriosis in the spleen, was not affected. However, NF-κB activity of CD11c-Cre Cyld(ex7/8 fl/fl) DCs was increased, while activation of ERK and p38 was normal. In addition, CD11c-Cre Cyld(ex7/8 fl/fl) DCs produced more TNF, IL-10, and IL-12 upon infection, which led to enhanced stimulation of IFN-γ-producing NK cells. In addition CD11c-Cre Cyld(ex7/8 fl/fl) DCs presented Listeria Ag more efficiently to CD8(+) T cells resulting in a stronger pathogen-specific CD8(+) T-cell proliferation and more IFN-γ production. Collectively, the improved innate and adaptive immunity and survival during listeriosis identify the DC-specific FL-CYLD/sCYLD balance as a potential target to modulate NK-cell and Ag-specific CD8(+) T-cell responses. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The CTLA4/CD28 gene region on chromosome 2q33 confers susceptibility to celiac disease in a way possibly distinct from that of type 1 diabetes and other chronic inflammatory disorders.

PubMed

Naluai, A T; Nilsson, S; Samuelsson, L; Gudjónsdóttir, A H; Ascher, H; Ek, J; Hallberg, B; Kristiansson, B; Martinsson, T; Nerman, O; Sollid, L M; Wahlström, J

2000-10-01

The effect of the gene region on chromosome 2q33 containing the CD28 and the cytotoxic T-lymphocyte associated (CTLA4) genes has been investigated in several diseases with chronic inflammatory nature. In addition to celiac disease (CD), type I diabetes, Grave's disease, rheumatoid arthritis and multiple sclerosis have all demonstrated associations to the A/G single nucleotide polymorphism (SNP) in exon 1, position +49 of the CTLA4 gene. The purpose of this study was to investigate this gene region in a genetically homogeneous population consisting of 107 Swedish and Norwegian families with CD using genetic association and linkage methods. We found a significant association with preferential transmission of the A-allele of the exon 1 +49 polymorphism by using the transmission disequilibrium test (TDT). Suggestive linkage of this region to CD was moreover demonstrated by non-parametric linkage (NPL) analysis giving a NPL-score of 2.1. These data strongly indicates that the CTLA4 region is a susceptibility region in CD. Interestingly, of the several chronic inflammatory diseases that exhibit associations to the CTLA4 +49 A/G dimorphism, CD appears to be the only disease associated to the A allele. This suggests that the +49 alleles of the CTLA4 gene are in linkage disequilibrium with two distinct disease predisposing alleles with separate effects. The peculiar association found in the gut disorder CD may possibly relate to the fact that the gastrointestinal immune system, in contrast to the rest of the immune system, aims to establish tolerance to foreign proteins.

Hydrodynamic immunization leads to poor CD8 T-cell expansion, low frequency of memory CTLs and ineffective antiviral protection.

PubMed

Obeng-Adjei, N; Choo, D K; Weiner, D B

2013-10-01

Hepatotropic pathogens, such as hepatitis B (HBV) and hepatitis C (HCV), often escape cellular immune clearance resulting in chronic infection. As HBV and HCV infections are the most common causes of hepatocellular carcinoma (HCC), prevention of these infections is believed to be key to the prevention of HCC. It is believed that an effective immune therapy must induce strong cytotonic T lymphocytes (CTLs) that can migrate into the liver, where they can clear infected hepatocytes. Here, we compared the induction of CD8 T cells by two different DNA immunization methods for T-cell differentiation, function, memory programming and their distribution within relevant tissues in a highly controlled fashion. We used hydrodynamic tail vein injection of plasmid to establish liver-specific LCMV-gp antigen (Ag) transient expression, and studied CD8 T cells induced using the P14 transgenic mouse model. CD8 T cells from this group exhibited unique and limited expansion, memory differentiation, polyfunctionality and cytotoxicity compared with T cells generated in intramuscularly immunized mice. This difference in liver-generated expansion resulted in lower memory CD8 T-cell frequency, leading to reduced protection against lethal viral challenge. These data show an unusual induction of naive CD8 T cells contributed to the lower frequency of Ag-specific CTLs observed after immunization in the liver, suggesting that limited priming in liver compared with peripheral tissues is responsible for this outcome.

Structural and elemental analysis of bottom sediments from the Paraíba do Sul River (SE, Brazil) by analytical microscopy

NASA Astrophysics Data System (ADS)

Miguens, Flávio Costa; Oliveira, Martha Lima de; Ferreira, Amanda de Oliveira; Barbosa, Laís Rodrigues; Melo, Edésio José Tenório de; Carvalho, Carlos Eduardo Veiga de

2016-03-01

The Paraíba do Sul River (PSR) is a medium-sized river that flows through the Minas Gerais, São Paulo and Rio de Janeiro Brazilian states the three most developed states in Brazil. Industrial parks and cities have historically been established along the river basin. The waters of PSR are used in agriculture, industry and human consumption of over 20 million people, including Rio de Janeiro City. Furthermore, the river receives effluent from these activities: agricultural runoff, industrial waste, and domestic sewage. Therefore, PSR has been considered polluted, particularly by heavy metals. In order to assess heavy metals in bottom sediments grains of the PSR, to infer their elemental composition, and to characterize individual sediment grains morphology, a non-destructive methodology - X-ray microanalyses (Scanning Electron Microscope coupled to Energy Dispersive X-rays Spectrometer/SEM/EDS) - was used. Heavy metals - Cr, Mn, Ni, Cu, Zn, Zr, Ag, Ba, Au, La, Ce, Nd, Th, Y, Sn, Os and Pb - were detected by SEM/EDS in bottom sediment grains from PSR, predominantly in grains with equivalent diameter ≤10 μm. They occurred as silicates, oxides (hydro-oxides), sulfides, carbonates, sulfates, phosphates and chlorides. All detected heavy metals occurred as, at least, one kind of soluble metal compound, mainly due to ionic exchange from silicates, with the exception of Ag, which was chloride, sulfate or metallic as Os, Au and Pb. These results corroborate heavy metal PSR pollution and food chain risk, considering that near-shore continental shelf is free of heavy metals contamination. Our results also give support to the hypothesis that the PSR estuary can act as a trap for these elements.

Magnetization and transport properties of silver-sheathed (Hg, Re)Ba2Ca2Cu3O8+delta tapes

NASA Astrophysics Data System (ADS)

Su, J. H.; Sastry, P. V. P. S. S.; Schwartz, J.

2003-10-01

(Hg, Re)Ba2Ca2Cu3O8+delta ((Hg, Re)-1223) samples have been fabricated by wrapping Re0.2Ba2Ca2Cu3Oy precursor powder within Ag foil and pressing or rolling. The Ag/precursor composite is then reacted with CaHgO2 in sealed reaction tubes. X-ray diffraction (XRD) patterns showed only one superconducting phase, (Hg, Re)-1223, in agreement with magnetization measurements showing an onset critical temperature (Tc) of 132 K. The magnetization properties were studied by dc magnetic measurements. The irreversibility line (Hirr), deduced from magnetization hysteresis loops, is approximated by a power law, Hirr ~ (1 - T/Tc)n, with n ~ 2.5, indicating moderate coupling between CuO2 layers compared to YBa2Cu3O7 (n ~ 1.5) and Bi/Tl-based superconductors (n ~ 5.5). The temperature dependence of the magnetization hysteresis loop width DeltaM showed three regimes, dominated by weak links at low temperature (regime I), thermally activated depinning of vortices at intermediate temperature (regime II) and giant flux creep at high temperature (regime III), respectively. Two field dependences were found in the intragrain critical current density (Jmagc) versus applied field at various temperatures: a weak one at lower temperature (leq50 K) and a stronger one at high temperature (geq65 K), indicating a transition from vortex lattice to vortex liquid in the tapes. The transport critical current density (Jtranc) of ~3 × 103 A cm-2 at 4.2 K and self-field was comparable to those for bulk Hg-based superconductors, indicating granular nature of the samples, which was confirmed further by XRD, scanning electron microscopy (SEM) and magneto-optical imaging (MOI).

Metals geochemistry and mass export from the Mississippi-Atchafalaya River system to the Northern Gulf of Mexico.

PubMed

Reiman, Jeremy H; Xu, Y Jun; He, Songjie; DelDuco, Emily M

2018-08-01

Discharging 680 km 3 of freshwater annually to the Northern Gulf of Mexico (NGOM), the Mississippi-Atchafalaya River System (MARS) plays a significant role in transporting major and trace elements to the ocean. In this study, we analyzed total recoverable concentrations of thirty-one metals from water samples collected at five locations along the MARS during 2013-2016 to quantify their seasonal mass exports. The Atchafalaya River flows through a large swamp floodplain, allowing us to also test the hypothesis that floodplains function as a sink for metals. We found that the seven major elements (Ca, Na, Mg, Si, K, Al, and Fe) constituted 99% of the total annual mass load of metals (7.38 × 10 7 tons) from the MARS. Higher concentrations of Al, Ba, B, Ca, Fe, Mg, Mn, Ag, and Ti were found in the Mississippi River, while significantly higher Si and Na concentrations were found in the Atchafalaya River. Significant relationships were found between daily discharge and daily loads of Ba, Ca, Fe, K, Sr, and Ti in both rivers, while significant relationships were also found for Al, Mg, Mn, V, and Zn in the Atchafalaya River and B in the Mississippi River. Overall, the Mississippi River contributed 64-76% of the total annual loading of metals from the MARS to the NGOM. Daily loads of Al, Ba, B, Fe, Li, Mn, P, K, Si, Ag, Ti, V, and Zn regularly decreased upstream to downstream in the Atchafalaya River, partially accepting the initial hypothesis on metals transport in river floodplains. Copyright © 2018 Elsevier Ltd. All rights reserved.

CuO added Pb0.92Sr0.06Ba0.02(Mg1/3Nb2/3)0.25(Ti0.53Zr0.47)0.75O3 ceramics sintered with Ag electrodes at 900 °C for multilayer piezoelectric actuator

NASA Astrophysics Data System (ADS)

Adnan Qaiser, Muhammad; Hussain, Ahmad; Xu, Yuqing; Wang, Yaojin; Wang, Yiping; Yang, Ying; Yuan, Guoliang

2017-03-01

Not Available Project supported by the National Natural Science Foundation of China (Grant Nos. 51472118, 51602156, 52177072, and 11274174) and the Fundamental Research Funds for the Central Universities, China (Grant Nos. 30916011104 and 30916011208).