Utility of CT Findings in the Diagnosis of Cecal Volvulus.

PubMed

Dane, Bari; Hindman, Nicole; Johnson, Evan; Rosenkrantz, Andrew B

2017-10-01

The objective of our study was to assess the utility of CT features in the diagnosis of cecal volvulus. Forty-three patients undergoing CT for cecal volvulus and with surgical or clinical follow-up were included. Two radiologists (11 years and 1 year of experience) evaluated CT examinations for the following: whirl sign, abnormal cecal position, "bird beak" sign, severe cecal distention, mesenteric engorgement, a newly described "central appendix" sign (defined as abnormal appendix position near midline), and overall impression for cecal volvulus. Univariable and multivariable assessments were performed. Patients with CT examinations in which the appendix was not visible were excluded from calculations involving the central appendix sign. Fifty-one percent (n = 22) of patients had cecal volvulus. All CT findings were significantly more common in patients with cecal volvulus (p < 0.01) other than mesenteric engorgement for reader 1 (p = 0.332). Readers 1 and 2 identified the central appendix sign in 92.9% and 92.3% of patients with volvulus versus in 37.5 and 31.1% of patients without volvulus. The whirl sign exhibited a sensitivity for cecal volvulus of 90.9% for reader 1 and 95.5% for reader 2, and a specificity of 61.9% for both readers. Abnormal cecal position exhibited a sensitivity of 90.0% for reader 1 and 100.0% for reader 2 and a specificity of 66.7% and 38.1%. The bird beak sign exhibited a sensitivity of 86.4% for reader 1 and 100.0% for reader 2 and a specificity of 85.7% and 71.4%. Severe cecal distention exhibited a sensitivity of 100.0% for both readers and a specificity of 81.0% and 61.9%. Mesenteric engorgement exhibited a sensitivity of 40.9% for reader 1 and 100.0% for reader 2 and a specificity of 76.2% and 71.4%. The central appendix sign exhibited a sensitivity of 92.9% for reader 1 and 92.3% for reader 2 and a specificity of 62.5% and 68.8%. Overall impression exhibited a sensitivity of 100.0% for both readers and a specificity of 76.2% and 57.1%. At multivariable analysis, the AUC for cecal volvulus ranged from 0.787 to 0.931, and the whirl sign was an independent predictor of volvulus for both readers (p ≤ 0.014); the central appendix sign was also an independent predictor in patients with a visualized appendix for reader 2 (p ≤ 0.001). CT exhibited high diagnostic performance and very high sensitivity for cecal volvulus. The whirl sign was a significant independent predictor of volvulus for both readers.

Self-assembled Li 3V 2(PO 4) 3/reduced graphene oxide multilayer composite prepared by sequential adsorption

DOE PAGES

Kim, Myeong-Seong; Bak, Seong-Min; Lee, Suk-Woo; ...

2017-09-26

Here in this paper, we report on Li 3V 2(PO 4) 3 (LVP)/reduced graphene oxide (rGO) multilayer composites prepared via a sequential adsorption method and subsequent heat treatment, and their use as cathodes for high-rate lithium-ion batteries. The sequential adsorption process includes adsorbing oppositely charged components of anionic inorganic species and cationic head of a surfactant adsorbed to graphite oxide sheets, which is a key step in the fabrication of the LVP/rGO multilayer composites. The multilayer structure has open channels between the highly conductive rGO layers while achieving a relatively high tap density, which could effectively improve the rate capability.more » Consequently, the LVP/rGO multilayer composites exhibit a high tap density (0.6 g cm -3) and good electrochemical properties. Specifically, in the voltage range of 3.0–4.3 V, the composite exhibits a specific capacity of 131 mAh g -1 at 0.1C, a good rate capabilities (88% capacity retention at 60C), and long cycling performance (97% capacity retention after 500 cycles at 10C). Moreover, in the extended voltage range of 3.0–4.8 V, it exhibits a high specific capacity of 185 mAh g -1 at 0.2C, a good rate capability (66% capacity retention at 30C), and stable cycling performance (96% capacity retention after 500 cycles at 10C).« less

Self-assembled Li 3V 2(PO 4) 3/reduced graphene oxide multilayer composite prepared by sequential adsorption

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

Kim, Myeong-Seong; Bak, Seong-Min; Lee, Suk-Woo

Here in this paper, we report on Li 3V 2(PO 4) 3 (LVP)/reduced graphene oxide (rGO) multilayer composites prepared via a sequential adsorption method and subsequent heat treatment, and their use as cathodes for high-rate lithium-ion batteries. The sequential adsorption process includes adsorbing oppositely charged components of anionic inorganic species and cationic head of a surfactant adsorbed to graphite oxide sheets, which is a key step in the fabrication of the LVP/rGO multilayer composites. The multilayer structure has open channels between the highly conductive rGO layers while achieving a relatively high tap density, which could effectively improve the rate capability.more » Consequently, the LVP/rGO multilayer composites exhibit a high tap density (0.6 g cm -3) and good electrochemical properties. Specifically, in the voltage range of 3.0–4.3 V, the composite exhibits a specific capacity of 131 mAh g -1 at 0.1C, a good rate capabilities (88% capacity retention at 60C), and long cycling performance (97% capacity retention after 500 cycles at 10C). Moreover, in the extended voltage range of 3.0–4.8 V, it exhibits a high specific capacity of 185 mAh g -1 at 0.2C, a good rate capability (66% capacity retention at 30C), and stable cycling performance (96% capacity retention after 500 cycles at 10C).« less

Hierarchically porous nitrogen-doped carbon derived from the activation of agriculture waste by potassium hydroxide and urea for high-performance supercapacitors

NASA Astrophysics Data System (ADS)

Zou, Kaixiang; Deng, Yuanfu; Chen, Juping; Qian, Yunqian; Yang, Yuewang; Li, Yingwei; Chen, Guohua

2018-02-01

Nitrogen-doped carbon with an ultra-high specific surface area and a hierarchically interconnected porous structure is synthesized in large scale from a green route, that is, the activation of bagasse via a one-step method using KOH and urea. KOH and urea play a synergistic effect for the enhancement of the specific surface area and the modification of pore size of the as-prepared material. Benefiting from the multiple synergistic roles originated from an ultra-high specific area (2905.4 m2 g-1), a high porous volume (2.05 mL g-1 with 75.6 vol% micropores, which is an ideal proportion of micropores for obtaining high specific capacitance), a suitable nitrogen content (2.63 wt%), and partial graphitization, the hierarchically interconnected porous N-doped carbon exhibits an excellent electrochemical performance with a high specific capacitance (350.8, 301.9, and 259.5 F g-1 at 1.0 A g-1 in acidic, alkaline, and neutral electrolytes, respectively), superior rate capability and excellent cycling stability (almost no capacitance loss up to 5000 cycles). Furthermore, the symmetric device assembled by this material achieves high energy densities of 39.1 and 23.5 Wh kg-1 at power densities of 1.0 and 20 kW kg-1, respectively, and exhibits an excellent long-term cycling stability (with capacitance retention above 95.0% after 10 000 cycles).

High-performance nanostructured supercapacitors on a sponge.

PubMed

Chen, Wei; Rakhi, R B; Hu, Liangbing; Xie, Xing; Cui, Yi; Alshareef, H N

2011-12-14

A simple and scalable method has been developed to fabricate nanostructured MnO2-carbon nanotube (CNT)-sponge hybrid electrodes. A novel supercapacitor, henceforth referred to as "sponge supercapacitor", has been fabricated using these hybrid electrodes with remarkable performance. A specific capacitance of 1,230 F/g (based on the mass of MnO2) can be reached. Capacitors based on CNT-sponge substrates (without MnO2) can be operated even under a high scan rate of 200 V/s, and they exhibit outstanding cycle performance with only 2% degradation after 100,000 cycles under a scan rate of 10 V/s. The MnO2-CNT-sponge supercapacitors show only 4% of degradation after 10,000 cycles at a charge-discharge specific current of 5 A/g. The specific power and energy of the MnO2-CNT-sponge supercapacitors are high with values of 63 kW/kg and 31 Wh/kg, respectively. The attractive performances exhibited by these sponge supercapacitors make them potentially promising candidates for future energy storage systems.

Facilitated charge transport in ternary interconnected electrodes for flexible supercapacitors with excellent power characteristics

NASA Astrophysics Data System (ADS)

Chen, Wanjun; He, Yongmin; Li, Xiaodong; Zhou, Jinyuan; Zhang, Zhenxing; Zhao, Changhui; Gong, Chengshi; Li, Shuankui; Pan, Xiaojun; Xie, Erqing

2013-11-01

Flexible and high performance supercapacitors are very critical in modern society. In order to develop the flexible supercapacitors with high power density, free-standing and flexible three-dimensional graphene/carbon nanotubes/MnO2 (3DG/CNTs/MnO2) composite electrodes with interconnected ternary 3D structures were fabricated, and the fast electron and ion transport channels were effectively constructed in the rationally designed electrodes. Consequently, the obtained 3DG/CNTs/MnO2 composite electrodes exhibit superior specific capacitance and rate capability compared to 3DG/MnO2 electrodes. Furthermore, the 3DG/CNTs/MnO2 based asymmetric supercapacitor demonstrates the maximum energy and power densities of 33.71 W h kg-1 and up to 22 727.3 W kg-1, respectively. Moreover, the asymmetric supercapacitor exhibits excellent cycling stability with 95.3% of the specific capacitance maintained after 1000 cycle tests. Our proposed synthesis strategy to construct the novel ternary 3D structured electrodes can be efficiently applied to other high performance energy storage/conversion systems.Flexible and high performance supercapacitors are very critical in modern society. In order to develop the flexible supercapacitors with high power density, free-standing and flexible three-dimensional graphene/carbon nanotubes/MnO2 (3DG/CNTs/MnO2) composite electrodes with interconnected ternary 3D structures were fabricated, and the fast electron and ion transport channels were effectively constructed in the rationally designed electrodes. Consequently, the obtained 3DG/CNTs/MnO2 composite electrodes exhibit superior specific capacitance and rate capability compared to 3DG/MnO2 electrodes. Furthermore, the 3DG/CNTs/MnO2 based asymmetric supercapacitor demonstrates the maximum energy and power densities of 33.71 W h kg-1 and up to 22 727.3 W kg-1, respectively. Moreover, the asymmetric supercapacitor exhibits excellent cycling stability with 95.3% of the specific capacitance maintained after 1000 cycle tests. Our proposed synthesis strategy to construct the novel ternary 3D structured electrodes can be efficiently applied to other high performance energy storage/conversion systems. Electronic supplementary information (ESI) available: Additional experimental details; calculations of the specific capacitances, and energy and power densities; additional SEM and optical images; XPS results; additional electrochemical results. See DOI: 10.1039/c3nr03923d

Synthesis of iron oxides nanoparticles with very high saturation magnetization form TEA-Fe(III) complex via electrochemical deposition for supercapacitor applications

NASA Astrophysics Data System (ADS)

Elrouby, Mahmoud; Abdel-Mawgoud, A. M.; El-Rahman, Rehab Abd

2017-11-01

This work is devoted to the synthesis of magnetic iron oxides nanoparticles with very high saturation magnetization to be qualified for supercapacitor applications using, a simple electrodeposition technique. It is found that the electrochemical reduction process depends on concentration, temperature, deposition potential and the scan rate of potential. The nature of electrodeposition process has been characterized via voltammetric and chronoamperometric techniques. The morphology of the electrodeposits has been investigated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The structure and phase content of these investigated electrodeposits have been examined and calculated. The obtained iron oxides show a high saturation magnetization (Ms) of about 229 emu g-1. The data exhibited a relation between Ms of electrodeposited iron oxide and specific capacitance. This relation exhibits that the highest Ms value of electrodeposited iron oxides gives also highest specific capacitance of about 725 Fg-1. Moreover, the electrodeposited iron oxides exhibit a very good stability. The new characteristics of the electro synthesized iron oxides at our optimized conditions, strongly qualify them as a valuable material for high-performance supercapacitor applications.

Efficacy of ACL injury risk screening methods in identifying high-risk landing patterns during a sport-specific task.

PubMed

Fox, A S; Bonacci, J; McLean, S G; Saunders, N

2017-05-01

Screening methods sensitive to movement strategies that increase anterior cruciate ligament (ACL) loads are likely to be effective in identifying athletes at-risk of ACL injury. Current ACL injury risk screening methods are yet to be evaluated for their ability to identify athletes' who exhibit high-risk lower limb mechanics during sport-specific maneuvers associated with ACL injury occurrences. The purpose of this study was to examine the efficacy of two ACL injury risk screening methods in identifying high-risk lower limb mechanics during a sport-specific landing task. Thirty-two female athletes were screened using the Landing Error Scoring System (LESS) and Tuck Jump Assessment. Participants' also completed a sport-specific landing task, during which three-dimensional kinematic and kinetic data were collected. One-dimensional statistical parametric mapping was used to examine the relationships between screening method scores, and the three-dimensional hip and knee joint rotation and moment data from the sport-specific landing. Higher LESS scores were associated with reduced knee flexion from 30 to 57 ms after initial contact (P = 0.003) during the sport-specific landing; however, no additional relationships were found. These findings suggest the LESS and Tuck Jump Assessment may have minimal applicability in identifying athletes' who exhibit high-risk landing postures in the sport-specific task examined. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Actin isoform specificity is required for the maintenance of lactation

PubMed Central

Weymouth, Nate; Shi, Zengdun; Rockey, Don C.

2014-01-01

Smooth muscle α-actin (Acta2) is one of six highly conserved mammalian actin isoforms that appear to exhibit functional redundancy. Nonetheless, we have postulated a specific functional role for the smooth muscle specific isoform. Here, we show that Acta2 deficient mice have a remarkable mammary phenotype such that dams lacking Acta2 are unable to nurse their offspring effectively. The phenotype was rescued in cross fostering experiments with wild type mice, excluding a developmental defect in Acta2 null pups. The mechanism for the underlying phenotype is due to myoepithelial dysfunction postpartum resulting in precocious involution. Further, we demonstrate a specific defect in myoepithelial cell contractility in Acta2 null mammary glands, despite normal expression of cytoplasmic actins. We conclude that Acta2 specifically mediates myoepithelial cell contraction during lactation and that this actin isoform therefore exhibits functional specificity. PMID:22123032

Three-dimensional porous activated carbon derived from loofah sponge biomass for supercapacitor applications

NASA Astrophysics Data System (ADS)

Su, Xiao-Li; Chen, Jing-Ran; Zheng, Guang-Ping; Yang, Jing-He; Guan, Xin-Xin; Liu, Pu; Zheng, Xiu-Cheng

2018-04-01

Biomass carbon source is generally cheap, environmentally friendly and readily available in high quality and quantity. In this work, a series of loofah sponge-derived activated carbon (SAC-x) with hierarchical porous structures are prepared by KOH chemical activation and used as electrode materials for supercapacitors. The pore size can be easily controllable by changing the dosage of KOH. The optimized material (SAC-4) exhibits a high specific capacitance of 309.6 F g-1 at 1 A g-1 in the three-electrode system using 6 M KOH electrolyte. More importantly, the as-assembled symmetric supercapacitor based on SAC-4 exhibits a high energy density of 16.1 Wh kg-1 at a power density of 160.0 W kg-1 using 1 M Na2SO4 electrolyte. These remarkable results demonstrate the exciting commercial potential of SAC-x for high-performance supercapacitor applications due to their high specific surface area, appropriately porous structure, and the trace heteroatom (O and N) functionalities.

Crystalline mesoporous tungsten oxide nanoplate monoliths synthesized by directed soft template method for highly sensitive NO{sub 2} gas sensor applications

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

Hoa, Nguyen Duc, E-mail: ndhoa@itims.edu.vn; Duy, Nguyen Van; Hieu, Nguyen Van, E-mail: hieu@itims.edu.vn

2013-02-15

Graphical abstract: Display Omitted Highlights: ► Mesoporous WO{sub 3} nanoplate monoliths were obtained by direct templating synthesis. ► Enable effective accession of the analytic molecules for the sensor applications. ► The WO{sub 3} sensor exhibited a high performance to NO{sub 2} gas at low temperature. -- Abstract: Controllable synthesis of nanostructured metal oxide semiconductors with nanocrystalline size, porous structure, and large specific surface area is one of the key issues for effective gas sensor applications. In this study, crystalline mesoporous tungsten oxide nanoplate-like monoliths with high specific surface areas were obtained through instant direct-templating synthesis for highly sensitive nitrogen dioxidemore » (NO{sub 2}) sensor applications. The copolymer soft template was converted into a solid carbon framework by heat treatment in an inert gas prior to calcinations in air to sustain the mesoporous structure of tungsten oxide. The multidirectional mesoporous structures of tungsten oxide with small crystalline size, large specific surface area, and superior physical characteristics enabled the rapid and effective accession of analytic gas molecules. As a result, the sensor response was enhanced and the response and recovery times were reduced, in which the mesoporous tungsten oxide based gas sensor exhibited a superior response of 21,155% to 5 ppm NO{sub 2}. In addition, the developed sensor exhibited selective detection of low NO{sub 2} concentration in ammonia and ethanol at a low temperature of approximately 150 °C.« less

Two-phase chromium-niobium alloys exhibiting improved mechanical properties at high temperatures

DOEpatents

Liu, Chain T.; Takeyama, Masao

1994-01-01

The specification discloses chromium-niobium alloys which exhibit improved mechanical properties at high temperatures in the range of 1250.degree. C. and improved room temperature ductility. The alloys contain a Cr.sub.2 Nb-rich intermetallic phase and a Cr-rich phase with an overall niobium concentration in the range of from about 5 to about 18 at. %. The high temperature strength is substantially greater than that of state of the art nickel-based superalloys for enhanced high temperature service. Further improvements in the properties of the compositions are obtained by alloying with rhenium and aluminum; and additional rare-earth and other elements.

Two-phase chromium-niobium alloys exhibiting improved mechanical properties at high temperatures

DOEpatents

Liu, C.T.; Takeyama, Masao.

1994-02-01

The specification discloses chromium-niobium alloys which exhibit improved mechanical properties at high temperatures in the range of 1250 C and improved room temperature ductility. The alloys contain a Cr[sub 2]Nb-rich intermetallic phase and a Cr-rich phase with an overall niobium concentration in the range of from about 5 to about 18 at. %. The high temperature strength is substantially greater than that of state of the art nickel-based superalloys for enhanced high temperature service. Further improvements in the properties of the compositions are obtained by alloying with rhenium and aluminum; and additional rare-earth and other elements. 14 figures.

Hollow Co2P nanoflowers assembled from nanorods for ultralong cycle-life supercapacitors.

PubMed

Cheng, Ming; Fan, Hongsheng; Xu, Yingying; Wang, Rongming; Zhang, Xixiang

2017-09-28

Hollow Co 2 P nanoflowers (Co 2 P HNFs) were successfully prepared via a one-step, template-free method. Microstructure analysis reveals that Co 2 P HNFs are assembled from nanorods and possess abundant mesopores and an amorphous carbon shell. Density functional theory calculations and electrochemical measurements demonstrate the high electrical conductivity of Co 2 P. Benefiting from the unique nanostructures, when employed as an electrode material for supercapacitors, Co 2 P HNFs exhibit a high specific capacitance, an outstanding rate capability, and an ultralong cycling stability. Furthermore, the constructed Co 2 P HNF//AC ASC exhibits a high energy density of 30.5 W h kg -1 at a power density of 850 W kg -1 , along with a superior cycling performance (108.0% specific capacitance retained after 10 000 cycles at 5 A g -1 ). These impressive results make Co 2 P HNFs a promising candidate for supercapacitor applications.

H3PO4 solution hydrothermal carbonization combined with KOH activation to prepare argy wormwood-based porous carbon for high-performance supercapacitors

NASA Astrophysics Data System (ADS)

Dai, Changchao; Wan, Jiafeng; Yang, Juan; Qu, Shanshan; Jin, Tieyu; Ma, Fangwei; Shao, Jinqiu

2018-06-01

In this work, argy wormwood-based porous carbon electrode materials for high-performance supercapacitors are prepared through H3PO4 solution hydrothermal carbonization and subsequent KOH activation. The obtained carbon has a specific surface area (SSA) of 927 m2 g-1, a total pore volume of 0.56 cm3 g-1, and a high oxygen (9.38%) content. In three-electrode system, it exhibits specific capacitance of 344 F g-1 at 1 A g-1. Moreover, the symmetric supercapacitor shows an excellent rate capability of 87% retention from 1 A g-1 to 10 A g-1, and a good cycling performance with 91.6% retention over 5000 cycles in 6 M KOH. Therefore, the sample activated by H3PO4 & KOH exhibits an excellent future in energy storage.

Monoclonal antibodies to human glycophorin A and cell lines for the production thereof

DOEpatents

Vanderlaan, Martin; Bigbee, William L.; Jensen, Ronald H.; Fong, Stella S. N.; Langlois, Richard G.

1988-01-01

Cloned mouse hybridoma cell lines have been established which continuously produce antibodies that are highly specific to and exhibit high affinity for glycophorin A.sup.N and differentiate between the M and N forms of human glycophorin A.

Laboratory Powder Metallurgy Makes Tough Aluminum Sheet

NASA Technical Reports Server (NTRS)

Royster, D. M.; Thomas, J. R.; Singleton, O. R.

1993-01-01

Aluminum alloy sheet exhibits high tensile and Kahn tear strengths. Rapid solidification of aluminum alloys in powder form and subsequent consolidation and fabrication processes used to tailor parts made of these alloys to satisfy such specific aerospace design requirements as high strength and toughness.

Direct binding to antigen-coated beads refines the specificity and cross-reactivity of four monoclonal antibodies that recognize polymorphic epitopes of HLA class I molecules.

PubMed

Hilton, H G; Parham, P

2013-04-01

Monoclonal antibodies with specificity for human leukocyte antigen (HLA) class I determinants of HLA were originally characterized using serological assays in which the targets were cells expressing three to six HLA class I variants. Because of this complexity, the specificities of the antibodies were defined indirectly by correlation. Here we use a direct binding assay, in which the targets are synthetic beads coated with 1 of 111 HLA class I variants, representing the full range of HLA-A, -B and -C variation. We studied one monoclonal antibody with monomorphic specificity (W6/32) and four with polymorphic specificity (MA2.1, PA2.1, BB7.2 and BB7.1) and compared the results with those obtained previously. W6/32 reacted with all HLA class I variants. MA2.1 not only exhibits high specificity for HLA-A*02, -B*57 and -B*58, but also exhibited cross-reactivity with HLA-A*11 and -B*15:16. At low concentration (1 µg/ml), PA2.1 and BB7.2 were both specific for HLA-A*02 and -A*69, and at high concentration (50 µg/ml) exhibited significant cross-reactions with HLA-A*68, -A*23 and -A*24. BB7.1 exhibits specificity for HLA-B*07 and -B*42, as previously described, but reacts equally well with HLA-B*81, a rare allotype defined some 16 years after the description of BB7.1. The results obtained with cell-based and bead-based assays are consistent and, in combination with amino acid sequence comparison, increase understanding of the polymorphic epitopes recognized by the MA2.1, PA2.1, BB7.2 and BB7.1 antibodies. Comparison of two overlapping but distinctive bead sets from two sources gave similar results, but the overall levels of binding were significantly different. Several weaker reactions were observed with only one of the bead sets. © 2013 John Wiley & Sons A/S.

Sex-specific patterns and deregulation of endocrine pathways in the gene expression profiles of Bangladeshi adults exposed to arsenic contaminated drinking water

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

Muñoz, Alexandra; Chervona, Yana; Hall, Megan

Arsenic contamination of drinking water occurs globally and is associated with numerous diseases including skin, lung and bladder cancers, and cardiovascular disease. Recent research indicates that arsenic may be an endocrine disruptor. This study was conducted to evaluate the nature of gene expression changes among males and females exposed to arsenic contaminated water in Bangladesh at high and low doses. Twenty-nine (55% male) Bangladeshi adults with water arsenic exposure ranging from 50 to 1000 μg/L were selected from the Folic Acid Creatinine Trial. RNA was extracted from peripheral blood mononuclear cells for gene expression profiling using Affymetrix 1.0 ST arrays.more » Differentially expressed genes were assessed between high and low exposure groups for males and females separately and findings were validated using quantitative real-time PCR. There were 534 and 645 differentially expressed genes (p < 0.05) in the peripheral blood mononuclear cells of males and females, respectively, when high and low water arsenic exposure groups were compared. Only 43 genes overlapped between the two sexes, with 29 changing in opposite directions. Despite the difference in gene sets both males and females exhibited common biological changes including deregulation of 17β-hydroxysteroid dehydrogenase enzymes, deregulation of genes downstream of Sp1 (specificity protein 1) transcription factor, and prediction of estrogen receptor alpha as a key hub in cardiovascular networks. Arsenic-exposed adults exhibit sex-specific gene expression profiles that implicate involvement of the endocrine system. Due to arsenic's possible role as an endocrine disruptor, exposure thresholds for arsenic may require different parameters for males and females. - Highlights: • Males and females exhibit unique gene expression changes in response to arsenic. • Only 23 genes are common among the differentially expressed genes for the sexes. • Male and female gene lists exhibit common biological implications. • Both sexes exhibit deregulation of cardiovascular and endocrine pathways.« less

Flexible solid-state supercapacitors based on three-dimensional graphene hydrogel films.

PubMed

Xu, Yuxi; Lin, Zhaoyang; Huang, Xiaoqing; Liu, Yuan; Huang, Yu; Duan, Xiangfeng

2013-05-28

Flexible solid-state supercapacitors are of considerable interest as mobile power supply for future flexible electronics. Graphene or carbon nanotubes based thin films have been used to fabricate flexible solid-state supercapacitors with high gravimetric specific capacitances (80-200 F/g), but usually with a rather low overall or areal specific capacitance (3-50 mF/cm(2)) due to the ultrasmall electrode thickness (typically a few micrometers) and ultralow mass loading, which is not desirable for practical applications. Here we report the exploration of a three-dimensional (3D) graphene hydrogel for the fabrication of high-performance solid-state flexible supercapacitors. With a highly interconnected 3D network structure, graphene hydrogel exhibits exceptional electrical conductivity and mechanical robustness to make it an excellent material for flexible energy storage devices. Our studies demonstrate that flexible supercapacitors with a 120 μm thick graphene hydrogel thin film can exhibit excellent capacitive characteristics, including a high gravimetric specific capacitance of 186 F/g (up to 196 F/g for a 42 μm thick electrode), an unprecedented areal specific capacitance of 372 mF/cm(2) (up to 402 mF/cm(2) for a 185 μm thick electrode), low leakage current (10.6 μA), excellent cycling stability, and extraordinary mechanical flexibility. This study demonstrates the exciting potential of 3D graphene macrostructures for high-performance flexible energy storage devices.

Facile Synthesis of Platelike Hierarchical Li1.2Mn0.54Ni0.13Co0.13O2 with Exposed {010} Planes for High-Rate and Long Cycling-Stable Lithium Ion Batteries.

PubMed

Zeng, Jiong; Cui, Yanhui; Qu, Deyang; Zhang, Qian; Wu, Junwei; Zhu, Xiaomeng; Li, Zuohua; Zhang, Xinhe

2016-10-05

Lithium-rich layered oxides are promising cathode candidates for the production of high-energy and high-power electronic devices with high specific capacity and high discharge voltage. However, unstable cycling performance, especially at high charge-recharge rate, is the most challenge issue which needs to be solved to foster the diffusion of these materials. In this paper, hierarchical platelike Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 cathode materials were synthesized by a facile solvothermal method followed by calcination. Calcination time was found to be a key parameter to obtain pure layered oxide phase and tailor its hierarchical morphology. The Li-rich material consists of primary nanoparticles with exposed {010} planes assembled to form platelike layers which exhibit low resistance to Li + diffusion. In detail, the product by calcination at 900 °C for 12 h exhibits specific capacity of 228, 218, and 204 mA h g -1 at 200, 400, and 1000 mA g -1 , respectively, whereas after 100 cycles at 1000 mA g -1 rate of charge and recharge the specific capacity was retained by about 91%.

Ultrathin Nickel Hydroxide and Oxide Nanosheets: Synthesis, Characterizations and Excellent Supercapacitor Performances

PubMed Central

Zhu, Youqi; Cao, Chuanbao; Tao, Shi; Chu, Wangsheng; Wu, Ziyu; Li, Yadong

2014-01-01

High-quality ultrathin two-dimensional nanosheets of α-Ni(OH)2 are synthesized at large scale via microwave-assisted liquid-phase growth under low-temperature atmospheric conditions. After heat treatment, non-layered NiO nanosheets are obtained while maintaining their original frame structure. The well-defined and freestanding nanosheets exhibit a micron-sized planar area and ultrathin thickness (<2 nm), suggesting an ultrahigh surface atom ratio with unique surface and electronic structure. The ultrathin 2D nanostructure can make most atoms exposed outside with high activity thus facilitate the surface-dependent electrochemical reaction processes. The ultrathin α-Ni(OH)2 and NiO nanosheets exhibit enhanced supercapacitor performances. Particularly, the α-Ni(OH)2 nanosheets exhibit a maximum specific capacitance of 4172.5 F g−1 at a current density of 1 A g−1. Even at higher rate of 16 A g−1, the specific capacitance is still maintained at 2680 F g−1 with 98.5% retention after 2000 cycles. Even more important, we develop a facile and scalable method to produce high-quality ultrathin transition metal hydroxide and oxide nanosheets and make a possibility in commercial applications. PMID:25168127

Tests of Rock Cores Scott Study Area, Missouri

DTIC Science & Technology

1970-05-01

porphyry with some granodiorite and small amounts of dolomite, acid metavolcanics, and dark gray volcanic breccia. Specific gravity, * Schmidt...petrographically identified as predominantly rhyolite and dacite porphyry with some granodiorite and small amounts of dolomite, acid metavolcanics, and dark...exhibit- ing little, if any, hysteresis. 9. Direct and indirect tensile strengths exhibited by tne rhyro- lite and dacite porphyry and granite are very high

A Rechargeable High-Temperature Molten Salt Iron-Oxygen Battery.

PubMed

Peng, Cheng; Guan, Chengzhi; Lin, Jun; Zhang, Shiyu; Bao, Hongliang; Wang, Yu; Xiao, Guoping; Chen, George Zheng; Wang, Jian-Qiang

2018-06-11

The energy and power density of conventional batteries are far lower than their theoretical expectations, primarily because of slow reaction kinetics that are often observed under ambient conditions. Here we describe a low-cost and high-temperature rechargeable iron-oxygen battery containing a bi-phase electrolyte of molten carbonate and solid oxide. This new design merges the merits of a solid-oxide fuel cell and molten metal-air battery, offering significantly improved battery reaction kinetics and power capability without compromising the energy capacity. The as-fabricated battery prototype can be charged at high current density, and exhibits excellent stability and security in the highly charged state. It typically exhibits specific energy, specific power, energy density, and power density of 129.1 Wh kg -1 , 2.8 kW kg -1 , 388.1 Wh L -1 , and 21.0 kW L -1 , respectively, based on the mass and volume of the molten salt. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hydrothermal synthesis of novel Mn3O4 nano-octahedrons with enhanced supercapacitors performances

NASA Astrophysics Data System (ADS)

Jiang, Hao; Zhao, Ting; Yan, Chaoyi; Ma, Jan; Li, Chunzhong

2010-10-01

Uniform and single-crystalline Mn3O4 nano-octahedrons have been successfully synthesized by a simple ethylenediaminetetraacetic acid disodium salt (EDTA-2Na) assisted hydrothermal route. The octahedron structures exhibit a high geometric symmetry with smooth surfaces and the mean side length of square base of octahedrons is ~160 nm. The structure is reckoned to provide superior functional properties and the nano-size achieved in the present work is noted to further facilitate the material property enhancement. The formation process was proposed to begin with a ``dissolution-recrystallization'' which is followed by an ``Ostwald ripening'' mechanism. The Mn3O4 nano-octahedrons exhibited an enhanced specific capacitance of 322 F g-1 compared with the truncated octahedrons with specific capacitances of 244 F g-1, making them a promising electrode material for supercapacitors.Uniform and single-crystalline Mn3O4 nano-octahedrons have been successfully synthesized by a simple ethylenediaminetetraacetic acid disodium salt (EDTA-2Na) assisted hydrothermal route. The octahedron structures exhibit a high geometric symmetry with smooth surfaces and the mean side length of square base of octahedrons is ~160 nm. The structure is reckoned to provide superior functional properties and the nano-size achieved in the present work is noted to further facilitate the material property enhancement. The formation process was proposed to begin with a ``dissolution-recrystallization'' which is followed by an ``Ostwald ripening'' mechanism. The Mn3O4 nano-octahedrons exhibited an enhanced specific capacitance of 322 F g-1 compared with the truncated octahedrons with specific capacitances of 244 F g-1, making them a promising electrode material for supercapacitors. Electronic supplementary information (ESI) available: TEM images; EDTA-2Na reaction details. See DOI: 10.1039/c0nr00257g

Monoclonal antibodies specific to sailfish serum albumin: development of an assay for the identification of fish species in the field.

PubMed

Rossi, E A; Shepard, S R; Poyer, J C; Hartmann, J X

1992-06-01

Balb/c mice were immunized with albumin purified from sailfish (Istiophorus albicans) serum. Hybridomas were produced and screened by ELISA for reactivity with the purified albumins of sailfish, blue marlin (Makaira nigricans) and white marlin (Tetrapturus albidus). Monoclonal antibodies (MAbs) from 16 different clones exhibited activity against sailfish albumin. Thirteen of the MAbs showed cross-reactivity with the marlin species. Three MAbs exhibited distinct specificity for sailfish albumin. One of these species specific MAbs (M2D1) was conjugated to horseradish peroxidase (HRP) in order to construct an ELISA for identification of sailfish from serum. The ELISA for sailfish correctly identified eight sailfish from 26 billfish serum samples. The MAb-peroxidase conjugate was highly specific toward sailfish in that no reaction against heterologous species was detected.

Fireworks induced particle pollution: A spatio-temporal analysis

NASA Astrophysics Data System (ADS)

Kumar, M.; Singh, R. K.; Murari, V.; Singh, A. K.; Singh, R. S.; Banerjee, T.

2016-11-01

Diwali-specific firework induced particle pollution was measured in terms of aerosol mass loading, type, optical properties and vertical distribution. Entire nation exhibited an increase in particulate concentrations specifically in Indo-Gangetic Plain (IGP). Aerosol surface mass loading at middle IGP revealed an increase of 56-121% during festival days in comparison to their background concentrations. Space-borne measurements (Aqua and Terra-MODIS) typically identified IGP with moderate to high AOD (0.3-0.8) during pre-festive days which transmutes to very high AOD (0.4-1.8) during Diwali-day with accumulation of aerosol fine mode fractions (0.3-1.0). Most of the aerosol surface monitoring stations exhibited increase in PM2.5 especially on Diwali-day while PM10 exhibited increase on subsequent days. Elemental compositions strongly support K, Ba, Sr, Cd, S and P to be considered as firework tracers. The upper and middle IGP revealed dominance of absorbing aerosols (OMI-AI: 0.80-1.40) while CALIPSO altitude-orbit-cross-section profiles established the presence of polluted dust which eventually modified with association of smoke and polluted continental during extreme fireworks. Diwali-specific these observations have implications on associating fireworks induced particle pollution and human health while inclusion of these observations should improve regional air quality model.

All-solid-state flexible supercapacitors based on highly dispersed polypyrrole nanowire and reduced graphene oxide composites.

PubMed

Yu, Chenfei; Ma, Peipei; Zhou, Xi; Wang, Anqi; Qian, Tao; Wu, Shishan; Chen, Qiang

2014-10-22

Highly dispersed polypyrrole nanowires are decorated on reduced graphene oxide sheets using a facile in situ synthesis route. The prepared composites exhibit high dispersibility, large effective surface area, and high electric conductivity. All-solid-state flexible supercapacitors are assembled based on the prepared composites, which show excellent electrochemical performances with a specific capacitance of 434.7 F g(-1) at a current density of 1 A g(-1). The as-fabricated supercapacitor also exhibits excellent cycling stability (88.1% capacitance retention after 5000 cycles) and exceptional mechanical flexibility. In addition, outstanding power and energy densities were obtained, demonstrating the significant potential of prepared material for flexible and portable energy storage devices.

Selective Impairment in Frequency Discrimination in a Mouse Model of Tinnitus

PubMed Central

Mwilambwe-Tshilobo, Laetitia; Davis, Andrew J. O.; Aizenberg, Mark; Geffen, Maria N.

2015-01-01

Tinnitus is an auditory disorder, which affects millions of Americans, including active duty service members and veterans. It is manifested by a phantom sound that is commonly restricted to a specific frequency range. Because tinnitus is associated with hearing deficits, understanding how tinnitus affects hearing perception is important for guiding therapies to improve the quality of life in this vast group of patients. In a rodent model of tinnitus, prolonged exposure to a tone leads to a selective decrease in gap detection in specific frequency bands. However, whether and how hearing acuity is affected for sounds within and outside those frequency bands is not well understood. We induced tinnitus in mice by prolonged exposure to a loud mid-range tone, and behaviorally assayed whether mice exhibited a change in frequency discrimination acuity for tones embedded within the mid-frequency range and high-frequency range at 1, 4, and 8 weeks post-exposure. A subset of tone-exposed mice exhibited tinnitus-like symptoms, as demonstrated by selective deficits in gap detection, which were restricted to the high frequency range. These mice exhibited impaired frequency discrimination both for tones in the mid-frequency range and high-frequency range. The remaining tone exposed mice, which did not demonstrate behavioral evidence of tinnitus, showed temporary deficits in frequency discrimination for tones in the mid-frequency range, while control mice remained unimpaired. Our findings reveal that the high frequency-specific deficits in gap detection, indicative of tinnitus, are associated with impairments in frequency discrimination at the frequency of the presumed tinnitus. PMID:26352864

Highly ordered mesoporous cobalt oxide nanostructures: synthesis, characterisation, magnetic properties, and applications for electrochemical energy devices.

PubMed

Wang, Guoxiu; Liu, Hao; Horvat, Josip; Wang, Bei; Qiao, Shizhang; Park, Jinsoo; Ahn, Hyojun

2010-09-24

Highly ordered mesoporous Co(3)O(4) nanostructures were prepared using KIT-6 and SBA-15 silica as hard templates. The structures were confirmed by small angle X-ray diffraction, high resolution transmission electron microscopy, and N(2) adsorption-desorption isotherm analysis. Both KIT-6 cubic and SBA-15 hexagonal mesoporous Co(3)O(4) samples exhibited a low Néel temperature and bulk antiferromagnetic coupling due to geometric confinement of antiferromagnetic order within the nanoparticles. Mesoporous Co(3)O(4) electrode materials have demonstrated the high lithium storage capacity of more than 1200 mAh g(-1) with an excellent cycle life. They also exhibited a high specific capacitance of 370 F g(-1) as electrodes in supercapacitors.

A health assessment of high status Christian burials recovered from the Roman-Byzantine archeological site of Elaiussa Sebaste, Turkey.

PubMed

Paine, R R; Vargiu, R; Coppa, A; Morselli, C; Schneider, E E

2007-01-01

The purpose of this study is to assess the state of health of 116 individuals whose remains were excavated from Byzantine period burials underneath the floor of an important Christian basilica from the site of Elaiussa Sebaste, Turkey. Elaiussa Sebaste was a Mediterranean coastal community, which began as a Roman town and continued as an early Christian Byzantine community until the end of the 7th century AD. The burials date from the middle of the 6th through the middle of the 7th centuries AD. We attempt to determine how high social status has influenced the type and frequency of skeletal lesions exhibited in this sample. All strata of this population show a number of chronic and acute health problems as indicated by skeletal lesions. Yet, only the frequency of degenerative joint disease (DJD) differs by sex, with males exhibiting a higher rate of DJD than females, p=0.09. There is no difference in the frequency of trauma among adult males and females. Non-specific skeletal lesions (cribra orbitalia, porotic hyperostosis, and periostitis) often associated with dietary and general stressors, but also with specific systemic diseases, are common in both sexes. The sub-adults primarily exhibit periostitis of the long bones and do not show skeletal lesions specific to malaria. It seems that high social ranking did not prevent serious ailments from affecting the health of individuals living in the Elaiussa Sebaste community.

Flexible Fe3O4@Carbon Nanofibers Hierarchically Assembled with MnO2 Particles for High-Performance Supercapacitor Electrodes.

PubMed

Iqbal, Nousheen; Wang, Xianfeng; Babar, Aijaz Ahmed; Zainab, Ghazala; Yu, Jianyong; Ding, Bin

2017-11-09

Increasing use of wearable electronic devices have resulted in enhanced demand for highly flexible supercapacitor electrodes with superior electrochemical performance. In this study, flexible composite membranes with electrosprayed MnO 2 particles uniformly anchored on Fe 3 O 4 doped electrospun carbon nanofibers (Fe 3 O 4 @CNF Mn ) have been prepared as flexible electrodes for high-performance supercapacitors. The interconnected porous beaded structure ensures free movement of electrolyte within the composite membranes, therefore, the developed supercapacitor electrodes not only offer high specific capacitance of ~306 F/g, but also exhibit good capacitance retention of ~85% after 2000 cycles, which certify that the synthesized electrodes offer high and stable electrochemical performance. Additionally, the supercapacitors fabricated from our developed electrodes well maintain their performance under flexural stress and exhibit a very minute change in specific capacitance even up to 180° bending angle. The developed electrode fabrication strategy integrating electrospinning and electrospray techniques paves new insights into the development of potential functional nanofibrous materials for light weight and flexible wearable supercapacitors.

Starvation, Together with the SOS Response, Mediates High Biofilm-Specific Tolerance to the Fluoroquinolone Ofloxacin

PubMed Central

Bernier, Steve P.; Lebeaux, David; DeFrancesco, Alicia S.; Valomon, Amandine; Soubigou, Guillaume; Coppée, Jean-Yves; Ghigo, Jean-Marc; Beloin, Christophe

2013-01-01

High levels of antibiotic tolerance are a hallmark of bacterial biofilms. In contrast to well-characterized inherited antibiotic resistance, molecular mechanisms leading to reversible and transient antibiotic tolerance displayed by biofilm bacteria are still poorly understood. The physiological heterogeneity of biofilms influences the formation of transient specialized subpopulations that may be more tolerant to antibiotics. In this study, we used random transposon mutagenesis to identify biofilm-specific tolerant mutants normally exhibited by subpopulations located in specialized niches of heterogeneous biofilms. Using Escherichia coli as a model organism, we demonstrated, through identification of amino acid auxotroph mutants, that starved biofilms exhibited significantly greater tolerance towards fluoroquinolone ofloxacin than their planktonic counterparts. We demonstrated that the biofilm-associated tolerance to ofloxacin was fully dependent on a functional SOS response upon starvation to both amino acids and carbon source and partially dependent on the stringent response upon leucine starvation. However, the biofilm-specific ofloxacin increased tolerance did not involve any of the SOS-induced toxin–antitoxin systems previously associated with formation of highly tolerant persisters. We further demonstrated that ofloxacin tolerance was induced as a function of biofilm age, which was dependent on the SOS response. Our results therefore show that the SOS stress response induced in heterogeneous and nutrient-deprived biofilm microenvironments is a molecular mechanism leading to biofilm-specific high tolerance to the fluoroquinolone ofloxacin. PMID:23300476

Expression of microphthalmia transcription factor, S100 protein, and HMB-45 in malignant melanoma and pigmented nevi.

PubMed

Xia, Jianxin; Wang, Yanlong; Li, Fuqiu; Wang, Jinfeng; Mu, Yan; Mei, Xianglin; Li, Xue; Zhu, Wenjing; Jin, Xianhua; Yu, Kai

2016-09-01

Malignant melanoma (MM) is a type of malignant tumor, which originates from neural crest melanocytes. MM progresses rapidly and results in a high mortality rate. The present study aims to investigate the expression of microphthalmia transcription factor (MITF), the S100 protein, and HMB-45 in MM and pigmented nevi. A total of 32 MM samples (including three skin metastasis, three lymph node metastasis and two spindle cell MM samples), two Spitz nevus samples, four pigmented nevus samples and two blue nevus samples were collected. The expression levels of S100 protein, HMB-45, and MITF were observed via immunostaining. The S100 protein exhibited high positive rates in MM and pigment disorders (96.7 and 100%, respectively), but with low specificity. The S100 protein was also expressed in fibroblasts, myoepithelial cells, histocytes and Langerhans cells in normal skin samples. HMB-45 had high specificity. Its positive expression was only confined to MM cells and junctional nevus cells. Furthermore, HMB-45 was not expressed in melanocytes in the normal tissue samples around the tumor or in the benign intradermal nevus cells. MITF exhibited high specificity and high sensitivity. It was expressed in the nuclei of melanocytes, MM cells and nevus cells. It was observed to be strongly expressed in metastatic MM and spindle cell MMs. Thus, MITF may present as a specific immunomarker for the diagnosis and differential diagnosis of MM.

Cushing's syndrome mutant PKA L205R exhibits altered substrate specificity

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

Lubner, Joshua M.; Dodge-Kafka, Kimberly L.; Carlson, Cathrine R.

The PKA L205R hotspot mutation has been implicated in Cushing's syndrome through hyperactive gain-of-function PKA signaling; however, its influence on substrate specificity has not been investigated. Here, we employ the Proteomic Peptide Library (ProPeL) approach to create high-resolution models for PKA WT and PKA L205R substrate specificity. We reveal that the L205R mutation reduces canonical hydrophobic preference at the substrate P + 1 position, and increases acidic preference in downstream positions. Using these models, we designed peptide substrates that exhibit altered selectivity for specific PKA variants, and demonstrate the feasibility of selective PKA L205R loss-of-function signaling. Through these results, wemore » suggest that substrate rewiring may contribute to Cushing's syndrome disease etiology, and introduce a powerful new paradigm for investigating mutation-induced kinase substrate rewiring in human disease.« less

Cushing's syndrome mutant PKA L205R exhibits altered substrate specificity

DOE PAGES

Lubner, Joshua M.; Dodge-Kafka, Kimberly L.; Carlson, Cathrine R.; ...

2017-02-01

The PKA L205R hotspot mutation has been implicated in Cushing's syndrome through hyperactive gain-of-function PKA signaling; however, its influence on substrate specificity has not been investigated. Here, we employ the Proteomic Peptide Library (ProPeL) approach to create high-resolution models for PKA WT and PKA L205R substrate specificity. We reveal that the L205R mutation reduces canonical hydrophobic preference at the substrate P + 1 position, and increases acidic preference in downstream positions. Using these models, we designed peptide substrates that exhibit altered selectivity for specific PKA variants, and demonstrate the feasibility of selective PKA L205R loss-of-function signaling. Through these results, wemore » suggest that substrate rewiring may contribute to Cushing's syndrome disease etiology, and introduce a powerful new paradigm for investigating mutation-induced kinase substrate rewiring in human disease.« less

Antimicrobial Resistance Percentages of Salmonella and Shigella in Seafood Imported to Jordan: Higher Percentages and More Diverse Profiles in Shigella.

PubMed

Obaidat, Mohammad M; Bani Salman, Alaa E

2017-03-01

This study determined the prevalence and antimicrobial resistance of human-specific ( Shigella spp.) and zoonotic ( Salmonella enterica ) foodborne pathogens in internationally traded seafood. Sixty-four Salmonella and 61 Shigella isolates were obtained from 330 imported fresh fish samples from Egypt, Yemen, and India. The pathogens were isolated on selective media, confirmed by PCR, and tested for antimicrobial resistance. Approximately 79 and 98% of the Salmonella and Shigella isolates, respectively, exhibited resistance to at least one antimicrobial, and 8 and 49% exhibited multidrug resistance (resistance to three or more antimicrobial classes). Generally, Salmonella exhibited high resistance to amoxicillin-clavulanic acid, cephalothin, streptomycin, and ampicillin; very low resistance to kanamycin, tetracycline, gentamicin, chloramphenicol, nalidixic acid, sulfamethoxazole-trimethoprim, and ciprofloxacin; and no resistance to ceftriaxone. Meanwhile, Shigella spp. exhibited high resistance to tetracycline, amoxicillin-clavulanic acid, cephalothin, streptomycin, and ampicillin; low resistance to kanamycin, nalidixic acid, sulfamethoxazole-trimethoprim, and ceftriaxone; and very low resistance to gentamicin and ciprofloxacin. Salmonella isolates exhibited 14 resistance profiles, Shigella isolates 42. This study is novel in showing that a human-specific pathogen has higher antimicrobial resistance percentages and more diverse profiles than a zoonotic pathogen. Thus, the impact of antimicrobial use in humans is as significant as, if not more significant than, it is in animals in spreading antibiotic resistance through food. This study also demonstrates that locally derived antimicrobial resistance can spread and pose a public health risk worldwide through seafood trade and that high resistance would make a possible outbreak difficult to control. So, capacity building and monitoring harvest water areas are encouraged in fish producing countries.

A Novel High-Mannose Specific Lectin from the Green Alga Halimeda renschii Exhibits a Potent Anti-Influenza Virus Activity through High-Affinity Binding to the Viral Hemagglutinin

PubMed Central

Mu, Jinmin; Hirayama, Makoto; Sato, Yuichiro; Morimoto, Kinjiro; Hori, Kanji

2017-01-01

We have isolated a novel lectin, named HRL40 from the green alga Halimeda renschii. In hemagglutination-inhibition test and oligosaccharide-binding experiment with 29 pyridylaminated oligosaccharides, HRL40 exhibited a strict binding specificity for high-mannose N-glycans having an exposed (α1-3) mannose residue in the D2 arm of branched mannosides, and did not have an affinity for monosaccharides and other oligosaccharides examined, including complex N-glycans, an N-glycan core pentasaccharide, and oligosaccharides from glycolipids. The carbohydrate binding profile of HRL40 resembled those of Type I high-mannose specific antiviral algal lectins, or the Oscillatoria agardhii agglutinin (OAA) family, which were previously isolated from red algae and a blue-green alga (cyanobacterium). HRL40 potently inhibited the infection of influenza virus (A/H3N2/Udorn/72) into NCI-H292 cells with half-maximal effective dose (ED50) of 2.45 nM through high-affinity binding to a viral envelope hemagglutinin (KD, 3.69 × 10−11 M). HRL40 consisted of two isolectins (HRL40-1 and HRL40-2), which could be separated by reverse-phase HPLC. Both isolectins had the same molecular weight of 46,564 Da and were a disulfide -linked tetrameric protein of a 11,641 Da polypeptide containing at least 13 half-cystines. Thus, HRL40, which is the first Type I high-mannose specific antiviral lectin from the green alga, had the same carbohydrate binding specificity as the OAA family, but a molecular structure distinct from the family. PMID:28813016

Coupled ultrasonication-milling synthesis of hierarchically porous carbon for high-performance supercapacitor.

PubMed

Yang, Dewei; Jing, Huijuan; Wang, Zhaowu; Li, Jiaheng; Hu, Mingxiang; Lv, Ruitao; Zhang, Rui; Chen, Deliang

2018-05-19

Activated carbon (AC) based supercapacitors exhibit intrinsic advantages in energy storage. Traditional two-step synthesis (carbonization and activation) of AC faces difficulties in precisely regulating its pore-size distribution and thoroughly removing residual impurities like silicon oxide. This paper reports a novel coupled ultrasonication-milling (CUM) process for the preparation of hierarchically porous carbon (HPC) using corn cobs as the carbon resource. The as-obtained HPC is of a large surface area (2288 m 2  g -1 ) with a high mesopore ratio of ∼44.6%. When tested in a three-electrode system, the HPC exhibits a high specific capacitance of 465 F g -1 at 0.5 Ag -1 , 2.7 times higher than that (170 F g -1 ) of the commercial AC (YP-50F). In the two-electrode test system, the HPC device exhibits a specific capacitance of 135 F g -1 at 1 A g -1 , twice higher than that (68 F g -1 ) of YP-50F. The above excellent energy-storage properties are resulted from the CUM process which efficiently removes the impurities and modulates the mesopore/micropore structures of the AC samples derived from the agricultural resides of corn cobs. The CUM process is an efficient method to prepare high-performance biomass-derived AC materials. Copyright © 2018 Elsevier Inc. All rights reserved.

Ternary manganese ferrite/graphene/polyaniline nanostructure with enhanced electrochemical capacitance performance

NASA Astrophysics Data System (ADS)

Xiong, Pan; Hu, Chenyao; Fan, Ye; Zhang, Wenyao; Zhu, Junwu; Wang, Xin

2014-11-01

A ternary manganese ferrite/graphene/polyaniline (MGP) nanostructure is designed and synthesized via a facile two-step approach. This nanostructure exhibits outstanding electrochemical performances, such as high specific capacitance (454.8 F g-1 at 0.2 A g-1), excellent rate capability (75.8% capacity retention at 5 A g-1), and good cycling stability (76.4% capacity retention after 5000 cycles at 2 A g-1), which are superior to those of its individual components (manganese ferrite, reduced-graphene oxide, polyaniline) and corresponding binary hybrids (manganese ferrite/graphene (MG), manganese ferrite/polyaniline (MP), and graphene/polyaniline (GP)). A symmetric supercapacitor device using the as-obtained hybrid has been fabricated and tested. The device exhibits a high specific capacitance of 307.2 F g-1 at 0.1 A g-1 with a maximum energy density of 13.5 W h kg-1. The high electrochemical performance of ternary MGP can be attributed to its well-designed nanostructure and the synergistic effect of the individual components.

Facile electrodeposition of reduced graphene oxide hydrogels for high-performance supercapacitors

NASA Astrophysics Data System (ADS)

Pham, Viet Hung; Gebre, Tesfaye; Dickerson, James H.

2015-03-01

We report both a facile, scalable method to prepare reduced graphene oxide hydrogels through the electrodeposition of graphene oxide and its use as an electrode for high-performance supercapacitors. Such systems exhibited specific capacitances of 147 and 223 F g-1 at a current density of 10 A g-1 when using H2SO4 and H2SO4 + hydroquinone redox electrolytes, respectively.We report both a facile, scalable method to prepare reduced graphene oxide hydrogels through the electrodeposition of graphene oxide and its use as an electrode for high-performance supercapacitors. Such systems exhibited specific capacitances of 147 and 223 F g-1 at a current density of 10 A g-1 when using H2SO4 and H2SO4 + hydroquinone redox electrolytes, respectively. Electronic supplementary information (ESI) available: GO synthesis, characterization, fabrication of ERGO supercapacitor and electrochemical measurement, elemental composition, TGA and XRD of GO and ERGO. See DOI: 10.1039/c4nr07508k

Flexible capacitive behavior of hybrid carbon materials prepared from graphene sheets

NASA Astrophysics Data System (ADS)

Ding, Y.-H.; Xie, W.; Zhang, P.; Jiang, Y.

2016-06-01

High frequency ultrasonication was employed to reduce the aggregation of graphene by constructing hybrid carbon materials (HCMs), which are endowed with a large electrochemical reaction area and high energy density. HCMs exhibited a specific capacitance of 168.5 F · g-1 with ˜100% capacitance retention over 500 cycles. Flexible supercapacitors fabricated from HCMs also showed an excellent capacitive behavior even under tough conditions. These outstanding electrochemical properties were ascribed to the increased specific surface area and open structure of HCMs.

Synthesis of a highly efficient 3D graphene-CNT-MnO2-PANI nanocomposite as a binder free electrode material for supercapacitors.

PubMed

Asif, Muhammad; Tan, Yi; Pan, Lujun; Rashad, Muhammad; Li, Jiayan; Fu, Xin; Cui, Ruixue

2016-09-29

Graphene based nanocomposites have been investigated intensively, as electrode materials for energy storage applications. In the current work, a graphene-CNT-MnO 2 -PANI (GCM@PANI) nanocomposite has been synthesized on 3D graphene grown on nickel foam, as a highly efficient binder free electrode material for supercapacitors. Interestingly, the specific capacitance of the synthesized electrode increases up to the first 1500 charge-discharge cycles, and is thus referred to as an electrode activation process. The activated GCM@PANI nanocomposite electrode exhibits an extraordinary galvanostatic specific capacitance of 3037 F g -1 at a current density of 8 A g -1 . The synthesized nanocomposite exhibits an excellent cyclic stability with a capacitance retention of 83% over 12 000 charge-discharge cycles, and a high rate capability by retaining a specific capacitance of 84.6% at a current density of 20 A g -1 . The structural and electrochemical analysis of the synthesized nanocomposite suggests that the astonishing electrochemical performance might be attributed to the growth of a novel PANI nanoparticle layer and the synergistic effect of CNT/MnO 2 nanostructures.

Black GE based on crystalline/amorphous core/shell nanoneedle arrays

DOEpatents

Javey, Ali; Chueh, Yu-Lun; Fan, Zhiyong

2014-03-04

Direct growth of black Ge on low-temperature substrates, including plastics and rubber is reported. The material is based on highly dense, crystalline/amorphous core/shell Ge nanoneedle arrays with ultrasharp tips (.about.4 nm) enabled by the Ni catalyzed vapor-solid-solid growth process. Ge nanoneedle arrays exhibit remarkable optical properties. Specifically, minimal optical reflectance (<1%) is observed, even for high angles of incidence (.about.75.degree.) and for relatively short nanoneedle lengths (.about.1 .mu.m). Furthermore, the material exhibits high optical absorption efficiency with an effective band gap of .about.1 eV. The reported black Ge can have important practical implications for efficient photovoltaic and photodetector applications on nonconventional substrates.

High volumetric supercapacitor with a long life span based on polymer dots and graphene sheets

NASA Astrophysics Data System (ADS)

Wei, Ji-Shi; Chen, Jie; Ding, Hui; Zhang, Peng; Wang, Yong-Gang; Xiong, Huan-Ming

2017-10-01

A series of polymer dots/graphene sheets composites with high densities are prepared and tested for supercapacitors. Polymer dots (PDs) are synthesized by one-step method at room temperature. They can effectively increase surface areas of the composites (almost 10 times), and the functional groups from PDs produce high pseudocapacitance, so that the samples exhibit high specific capacitances (e. g., 364.2 F cm-3 at 1 A g-1) and high cycling stability (e. g., more than 95% of the initial capacity retention over 10 000 cycles at different current densities). The optimal sample is employed to fabricate a symmetric supercapacitor, which exhibits an energy density up to 8 Wh L-1 and a power density up to 11 800 W L-1, respectively.

Survey of TES high albedo events in Mars' northern polar craters

USGS Publications Warehouse

Armstrong, J.C.; Nielson, S.K.; Titus, T.N.

2007-01-01

Following the work exploring Korolev Crater (Armstrong et al., 2005) for evidence of crater interior ice deposits, we have conducted a survey of Thermal Emission Spectroscopy (TES) temperature and albedo measurements for Mars' northern polar craters larger than 10 km. Specifically, we identify a class of craters that exhibits brightening in their interiors during a solar longitude, Ls, of 60 to 120 degrees, roughly depending on latitude. These craters vary in size, latitude, and morphology, but appear to have a specific regional association on the surface that correlates with the distribution of subsurface hydrogen (interpreted as water ice) previously observed on Mars. We suggest that these craters, like Korolev, exhibit seasonal high albedo frost events that indicate subsurface water ice within the craters. A detailed study of these craters may provide insight in the geographical distribution of the ice and context for future polar missions. Copyright 2007 by the American Geophysical Union.

Functionalized graphene nanomaterials: new insight into direct exfoliation of graphite with supramolecular polymers

NASA Astrophysics Data System (ADS)

Cheng, Chih-Chia; Chang, Feng-Chih; Wang, Jui-Hsu; Chen, Jem-Kun; Yen, Ying-Chieh; Lee, Duu-Jong

2015-12-01

A novel urea-cytosine end-capped polypropylene glycol (UrCy-PPG) can self-assemble into a long-range ordered lamellar microstructure on the surface of graphene, due to the strong specific interactions between UrCy-PPG and graphene. In addition, the graphene composite produced exhibits a high conductivity (~1093 S m-1) with a dramatic thermo-responsive ON/OFF resistance-switching behavior (10 consecutive cycles).A novel urea-cytosine end-capped polypropylene glycol (UrCy-PPG) can self-assemble into a long-range ordered lamellar microstructure on the surface of graphene, due to the strong specific interactions between UrCy-PPG and graphene. In addition, the graphene composite produced exhibits a high conductivity (~1093 S m-1) with a dramatic thermo-responsive ON/OFF resistance-switching behavior (10 consecutive cycles). Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07076g

High Pressure Compression-Molding of α-Cellulose and Effects of Operating Conditions.

PubMed

Pintiaux, Thibaud; Viet, David; Vandenbossche, Virginie; Rigal, Luc; Rouilly, Antoine

2013-05-30

Commercial α-cellulose was compression-molded to produce 1A dog-bone specimens under various operating conditions without any additive. The resulting agromaterials exhibited a smooth, plastic-like surface, and constituted a suitable target as replacement for plastic materials. Tensile and three-points bending tests were conducted according to ISO standards related to the evaluation of plastic materials. The specimens had strengths comparable to classical petroleum-based thermoplastics. They also exhibited high moduli, which is characteristic of brittle materials. A higher temperature and higher pressure rate produced specimens with higher mechanical properties while low moisture content produced weaker specimens. Generally, the strong specimen had higher specific gravity and lower moisture content. However, some parameters did not follow the general trend e.g., thinner specimen showed much higher Young's Modulus, although their specific gravity and moisture content remained similar to control, revealing a marked skin-effect which was confirmed by SEM observations.

High Pressure Compression-Molding of α-Cellulose and Effects of Operating Conditions

PubMed Central

Pintiaux, Thibaud; Viet, David; Vandenbossche, Virginie; Rigal, Luc; Rouilly, Antoine

2013-01-01

Commercial α-cellulose was compression-molded to produce 1A dog-bone specimens under various operating conditions without any additive. The resulting agromaterials exhibited a smooth, plastic-like surface, and constituted a suitable target as replacement for plastic materials. Tensile and three-points bending tests were conducted according to ISO standards related to the evaluation of plastic materials. The specimens had strengths comparable to classical petroleum-based thermoplastics. They also exhibited high moduli, which is characteristic of brittle materials. A higher temperature and higher pressure rate produced specimens with higher mechanical properties while low moisture content produced weaker specimens. Generally, the strong specimen had higher specific gravity and lower moisture content. However, some parameters did not follow the general trend e.g., thinner specimen showed much higher Young’s Modulus, although their specific gravity and moisture content remained similar to control, revealing a marked skin-effect which was confirmed by SEM observations. PMID:28809271

Junctionless Thin-Film Transistors Gated by an H₃PO₄-Incorporated Chitosan Proton Conductor.

PubMed

Liu, Huixuan; Xun, Damao

2018-04-01

We fabricated an H3PO4-incorporated chitosan proton conductor film that exhibited the electric double layer effect and showed a high specific capacitance of 4.42 μF/cm2. Transparent indium tin oxide thin-film transistors gated by H3PO4-incorporated chitosan films were fabricated by sputtering through a shadow mask. The operating voltage was as low as 1.2 V because of the high specific capacitance of the H3PO4-incorporated chitosan dielectrics. The junctionless transparent indium tin oxide thin film transistors exhibited good performance, including an estimated current on/off ratio and field-effect mobility of 1.2 × 106 and 6.63 cm2V-1s-1, respectively. These low-voltage thin-film electric-double-layer transistors gated by H3PO4-incorporated chitosan are promising for next generation battery-powered "see-through" portable sensors.

The Rey Auditory Verbal Learning Test forced-choice recognition task: Base-rate data and norms.

PubMed

Poreh, Amir; Bezdicek, Ondrej; Korobkova, Irina; Levin, Jennifer B; Dines, Philipp

2016-01-01

The present study describes a novel Forced-Choice Response (FCR) index for detecting poor effort on the Rey Auditory Verbal Learning Test (RAVLT). This retrospective study analyzes the performance of 4 groups on the new index: clinically referred patients with suspected dementia, forensic patients identified as not exhibiting adequate effort on other measures of response bias, students who simulated poor effort, and a large normative sample collected in the Gulf State of Oman. Using sensitivity and specificity analyses, the study shows that much like the California Verbal Learning Test-Second Edition FCR index, the RAVLT FCR index misses a proportion of individuals with inadequate effort (low sensitivity), but those who fail this measure are highly likely to be exhibiting poor effort (high specificity). The limitations and benefits of utilizing the RAVLT FCR index in clinical practice are discussed.

Anorexia Nervosa: An Overview for the School Counselor.

ERIC Educational Resources Information Center

Nufrio, Ronald M.

Anorexia nervosa is a serious eating disorder which affects thousands of people every year. Ninety-five percent of all anorexics are females with the peak age of onset between 14 and 18. While anorexics fit into no specific stereotype, high-risk candidates are often perfectionists and model children who exhibit self-doubt, high conformity,…

90Sr in teeth of cattle abandoned in evacuation zone: Record of pollution from the Fukushima-Daiichi Nuclear Power Plant accident

NASA Astrophysics Data System (ADS)

Koarai, Kazuma; Kino, Yasushi; Takahashi, Atsushi; Suzuki, Toshihiko; Shimizu, Yoshinaka; Chiba, Mirei; Osaka, Ken; Sasaki, Keiichi; Fukuda, Tomokazu; Isogai, Emiko; Yamashiro, Hideaki; Oka, Toshitaka; Sekine, Tsutomu; Fukumoto, Manabu; Shinoda, Hisashi

2016-04-01

Here we determined the 90Sr concentrations in the teeth of cattle abandoned in the evacuation area of the Fukushima-Daiichi Nuclear Power Plant (FNPP) accident. 90Sr activity concentrations in the teeth varied from 6-831 mBq (g Ca)-1 and exhibited a positive relationship with the degree of radioactive contamination that the cattle experienced. Even within an individual animal, the specific activity of 90Sr (Bq (g Sr)-1) varied depending on the development stage of the teeth during the FNPP accident: teeth that were early in development exhibited high 90Sr specific activities, while teeth that were late in development exhibited low specific activities. These findings demonstrate that 90Sr is incorporated into the teeth during tooth development; thus, tooth 90Sr activity concentrations reflect environmental 90Sr levels during tooth formation. Assessment of 90Sr in teeth could provide useful information about internal exposure to 90Sr radiation and allow for the measurement of time-course changes in the degree of environmental 90Sr pollution.

(90)Sr in teeth of cattle abandoned in evacuation zone: Record of pollution from the Fukushima-Daiichi Nuclear Power Plant accident.

PubMed

Koarai, Kazuma; Kino, Yasushi; Takahashi, Atsushi; Suzuki, Toshihiko; Shimizu, Yoshinaka; Chiba, Mirei; Osaka, Ken; Sasaki, Keiichi; Fukuda, Tomokazu; Isogai, Emiko; Yamashiro, Hideaki; Oka, Toshitaka; Sekine, Tsutomu; Fukumoto, Manabu; Shinoda, Hisashi

2016-04-05

Here we determined the (90)Sr concentrations in the teeth of cattle abandoned in the evacuation area of the Fukushima-Daiichi Nuclear Power Plant (FNPP) accident. (90)Sr activity concentrations in the teeth varied from 6-831 mBq (g Ca)(-1) and exhibited a positive relationship with the degree of radioactive contamination that the cattle experienced. Even within an individual animal, the specific activity of (90)Sr (Bq (g Sr)(-1)) varied depending on the development stage of the teeth during the FNPP accident: teeth that were early in development exhibited high (90)Sr specific activities, while teeth that were late in development exhibited low specific activities. These findings demonstrate that (90)Sr is incorporated into the teeth during tooth development; thus, tooth (90)Sr activity concentrations reflect environmental (90)Sr levels during tooth formation. Assessment of (90)Sr in teeth could provide useful information about internal exposure to (90)Sr radiation and allow for the measurement of time-course changes in the degree of environmental (90)Sr pollution.

90Sr in teeth of cattle abandoned in evacuation zone: Record of pollution from the Fukushima-Daiichi Nuclear Power Plant accident

PubMed Central

Koarai, Kazuma; Kino, Yasushi; Takahashi, Atsushi; Suzuki, Toshihiko; Shimizu, Yoshinaka; Chiba, Mirei; Osaka, Ken; Sasaki, Keiichi; Fukuda, Tomokazu; Isogai, Emiko; Yamashiro, Hideaki; Oka, Toshitaka; Sekine, Tsutomu; Fukumoto, Manabu; Shinoda, Hisashi

2016-01-01

Here we determined the 90Sr concentrations in the teeth of cattle abandoned in the evacuation area of the Fukushima-Daiichi Nuclear Power Plant (FNPP) accident. 90Sr activity concentrations in the teeth varied from 6–831 mBq (g Ca)−1 and exhibited a positive relationship with the degree of radioactive contamination that the cattle experienced. Even within an individual animal, the specific activity of 90Sr (Bq (g Sr)−1) varied depending on the development stage of the teeth during the FNPP accident: teeth that were early in development exhibited high 90Sr specific activities, while teeth that were late in development exhibited low specific activities. These findings demonstrate that 90Sr is incorporated into the teeth during tooth development; thus, tooth 90Sr activity concentrations reflect environmental 90Sr levels during tooth formation. Assessment of 90Sr in teeth could provide useful information about internal exposure to 90Sr radiation and allow for the measurement of time-course changes in the degree of environmental 90Sr pollution. PMID:27045764

Synthesis of hollow NiCo2O4 nanospheres with large specific surface area for asymmetric supercapacitors.

PubMed

Xu, Kaibing; Yang, Jianmao; Hu, Junqing

2018-02-01

Hollow micro-/nanostructured electrode materials with high active surface area are highly desirable for achieving outstanding electrochemical properties. Herein, we report the successful synthesis of hierarchical hollow NiCo 2 O 4 nanospheres with high surface area as electrode materials for supercapacitors. Electrochemical measurements prove that such electrode materials exhibit excellent electrochemical behavior with a specific capacitance reaching 1229 F/g at 1 A/g, remarkable rate performance (∼83.6% retention from 1 to 25 A/g) and good cycling performance (86.3% after 3000 cycles). Furthermore, the asymmetric supercapacitor is fabricated with hollow NiCo 2 O 4 nanospheres electrode and activated carbon (AC) electrode as the positive and negative, respectively. This device exhibits a maximum energy density of 21.5 W h/kg, excellent cycling performance and coulombic efficiency. The results show that hollow NiCo 2 O 4 nanosphere electrode is a promising electrode material for the future application in high performance supercapacitors. Copyright © 2017 Elsevier Inc. All rights reserved.

Electrospun single crystalline fork-like K2V8O21 as high-performance cathode materials for lithium-ion batteries

NASA Astrophysics Data System (ADS)

Hao, Pengfei; Zhu, Ting; Su, Qiong; Lin, Jiande; Cui, Rong; Cao, Xinxin; Wang, Yaping; Pan, Anqiang

2018-06-01

Single crystalline fork-like potassium vanadate (K2V8O21) has been successfully prepared through electrospinning combined with a subsequent annealing process. The as-obtained K2V8O21 forks show a unique layer-by-layer stacked structure with conductive carbon. When used as cathode materials for lithium-ion batteries, the as-prepared fork-like materials exhibit high specific discharge capacity and excellent cyclic stability. High specific discharge capacity of 200.2 mA h g-1 and 131.5 mA h g-1 can be delivered at the current densities of 50 mA g-1 and 500 mA g-1, respectively. Furthermore, the K2V8O21 electrodes exhibit excellent long-term cycling stability that maintain a capacity of 108.3 mA h g-1 after 300 cycles at 500 mA g-1 with a fading rate of only 0.054% per cycle, revealing their potential applications in next generation high-performance lithium-ion batteries.

Exploring aligned-carbon-nanotubes@polyaniline arrays on household Al as supercapacitors.

PubMed

Huang, Fan; Lou, Fengliu; Chen, De

2012-05-01

Herein, we demonstrate a new approach towards the construction of supercapacitors consisting of carbon nanotubes (CNTs) and conducting polymers (ECPs) with high specific power, high specific energy, and stable cycling performance through a 3D design of a thin film of polyaniline (PANI) on an aligned small carbon nanotube (ACNT) array on household Al foils. The thin-film strategy is used to fully exploit the specific capacitance of PANI, and obtain regular pores, strong interaction between PANI and CNTs, and reduced electrical resistance for the electrodes. A facile process is developed to fabricate a highly flexible supercapacitor using this binder-free composite on household Al foil as the current collector. It exhibits high specific energy of 18.9 Wh kg(-1) , high maximum specific power of 11.3 kW kg(-1) of the active material in an aqueous electrolyte at 1.0 A g(-1) , and excellent rate performance and cycling stability. A high specific energy of 72.4 Wh kg(-1) , a high maximum specific power of 24.9 kW kg(-1) , and a good cycling performance of the active material are obtained in an organic electrolyte. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ability among adolescents for the metabolic syndrome to predict elevations in factors associated with type 2 diabetes and cardiovascular disease: data from the national health and nutrition examination survey 1999-2006.

PubMed

DeBoer, Mark D; Gurka, Matthew J

2010-08-01

The aim of this study was to compare currently proposed sets of pediatric metabolic syndrome criteria for the ability to predict elevations in "surrogate" factors that are associated with metabolic syndrome and with future cardiovascular disease and type 2 diabetes mellitus. These surrogate factors were fasting insulin, hemoglobin A1c (HbA1c), high-sensitivity C-reactive protein (hsCRP), and uric acid. Waist circumference (WC), blood pressure, triglycerides, high-density lipoprotein cholesterol (HDL-C), fasting glucose, fasting insulin, HbA1c, hsCRP, and uric acid measurements were obtained from 2,624 adolescent (12-18 years old) participants of the 1999-2006 National Health and Nutrition Examination Surveys. We identified children with metabolic syndrome as defined by six commonly used sets of pediatric metabolic syndrome criteria. We then defined elevations in the surrogate factors as values in the top 5% for the cohort and calculated sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for each set of metabolic syndrome criteria and for each surrogate factor. Current pediatric metabolic syndrome criteria exhibited variable sensitivity and specificity for surrogate predictions. Metabolic syndrome criteria had the highest sensitivity for predicting fasting insulin (40-70%), followed by uric acid (31-54%), hsCRP (13-31%), and HbA1c (7-21%). The criteria of de Ferranti (which includes children with WC >75(th) percentile, compared to all other sets including children with WC >90(th) percentile) exhibited the highest sensitivity for predicting each of the surrogates, with only modest decrease in specificity compared to the other sets of criteria. However, the de Ferranti criteria also exhibited the lowest PPV values. Conversely, the pediatric International Diabetes Federation criteria exhibited the lowest sensitivity and the highest specificity. Pediatric metabolic syndrome criteria exhibit moderate sensitivity for detecting elevations in surrogate factors associated with metabolic syndrome and with risk for future disease. Inclusion of children with more modestly elevated WC improved sensitivity.

Structure-matched Phthalocyanine Ion Pair as a Red-emitting Fluorescent Optical Probe for the Analysis of Sodium Dodecylbenzenesulfonate with High Specificity and Sensitivity.

PubMed

Yu, Fei; Guo, Menglin; Deng, Yabin; Lu, Yin; Chen, Lin; Huang, Ping; Li, Donghui

2016-01-01

We have found that a positively charged cationic copper phthalocyanine, Alcian blue (Alcian blue 8GX), can efficiently quench the fluorescence of an oppositely charged red fluorescent phthalocyanine compound with a matched molecular structure, tetrasulfonated aluminum phthalocyanine (AlS4Pc), because of the formation of an ion pair complex (AlS4Pc-Alcian blue 8GX) that exhibits almost no fluorescence. An investigation was carried out on the fluorescence recovery of AlS4Pc-Alcian blue 8GX caused by a series of anionic surfactants containing a sulfonic group (sodium dodecylbenzenesulfonate (SDBS), sodium lauryl sulfate (SLS), and sodium dodecyl sulfate (SDS)). The results showed that SDBS exhibited a significant response, and the highest sensitivity among the surfactants. Due to its high efficiency of fluorescence quenching and the high level of fluorescence recovery, direct observes can even be performed by the naked eye. The results revealed that the Alcian blue 8GX-AlS4Pc ion-pair complex fluorescent probe only responded to SDBS in the low-concentration range. Based on the new founding, this study proposed a novel principle and method of fluorescence enhancement to specifically measure the concentration of SDBS, thereby achieving a highly sensitive and highly specific determination of SDBS. Under the optimal conditions, the fluorescence intensity (I(f)) of the system and the concentration of SDBS in the range of 1 × 10(-7) - 1 × 10(-5) mol/dm(3) exhibited a good linear relationship. This method is highly sensitive, and the operation is simple and rapid. It had been applied for the quantitative analysis of SDBS in environmental water, while achieving satisfactory results compared with those of the standard method. This study developed a new application of the fluorescent phthalocyanine compounds used as molecular probes in analytical sciences.

Corrosion resistant iron aluminides exhibiting improved mechanical properties and corrosion resistance

DOEpatents

Liu, C.T.; McKamey, C.G.; Tortorelli, P.F.; David, S.A.

1994-06-14

The specification discloses a corrosion-resistant intermetallic alloy comprising, in atomic percent, an FeAl iron aluminide containing from about 30 to about 40% aluminum alloyed with from about 0.01 to 0.4% zirconium and from 0.01 to about 0.8% boron. The alloy exhibits considerably improved room temperature ductility for enhanced usefulness in structural applications. The high temperature strength and fabricability is improved by alloying with molybdenum, carbon, chromium and vanadium. 9 figs.

Diversity, Stability, and Reproducibility in Stochastically Assembled Microbial Ecosystems

NASA Astrophysics Data System (ADS)

Goyal, Akshit; Maslov, Sergei

2018-04-01

Microbial ecosystems are remarkably diverse, stable, and usually consist of a mixture of core and peripheral species. Here we propose a conceptual model exhibiting all these emergent properties in quantitative agreement with real ecosystem data, specifically species abundance and prevalence distributions. Resource competition and metabolic commensalism drive the stochastic ecosystem assembly in our model. We demonstrate that even when supplied with just one resource, ecosystems can exhibit high diversity, increasing stability, and partial reproducibility between samples.

Corrosion resistant iron aluminides exhibiting improved mechanical properties and corrosion resistance

DOEpatents

Liu, Chain T.; McKamey, Claudette G.; Tortorelli, Peter F.; David, Stan A.

1994-01-01

The specification discloses a corrosion-resistant intermetallic alloy comprising, in atomic percent, an FeAl iron aluminide containing from about 30 to about 40% aluminum alloyed with from about 0.01 to 0.4% zirconium and from 0.01 to about 0.8% boron. The alloy exhibits considerably improved room temperature ductility for enhanced usefulness in structural applications. The high temperature strength and fabricability is improved by alloying with molybdenum, carbon, chromium and vanadium.

CHARACTERIZATION OF A NARROW SPECTRUM ANTIMICROBIAL THAT EXHIBITS SPECIFIC ACTIVITY AGAINST UROPATHOGENIC BACTERIA

DTIC Science & Technology

2017-08-28

NARROW-SPECTRUM ANTIMICROBIAL THAT EXHIBITS SPECIFIC ACTIVITY AGAINST UROPATHOGENIC BACTERIA by Caitlin M. Barrows Courtney M. Cowell Jennifer...From - To) October 2015 – September 2016 4. TITLE AND SUBTITLE CHARACTERIZATION OF A NARROW-SPECTRUM ANTIMICROBIAL THAT EXHIBITS SPECIFIC ACTIVITY ...objective of the work described in this report is to identify a narrow-spectrum antimicrobial that exhibits targeted activity against uropathogenic

In-situ synthesis of monodisperse micro-nanospherical LiFePO4/carbon cathode composites for lithium-ion batteries

NASA Astrophysics Data System (ADS)

Gong, Hao; Xue, Hairong; Wang, Tao; He, Jianping

2016-06-01

The LiFePO4 is recognized as the promising cathode material, due to its high specific capacity, excellent, structural stability and environmental benignity. However, it is blamed for the low tap density and poor rate performance when served as the cathode materials for a long time. Here, the microspheric LiFePO4/C composites are successfully synthesized through a one-step in-situ solvothermal method combined with carbothermic reduction. These LiFePO4/C microspheres are assembled by LiFePO4 nanoparticles (∼100 nm) and uniformly coated by the carbon, which show a narrow diameter distribution of 4 μm. As a cathode material for lithium ion batteries, the LiFePO4/C composites can deliver an initiate charge capacity of 155 mAh g-1 and retain 90% of initial capacity after 200 cycles at 0.1 C. When cycled at high current densities up to 20 C, it shows a discharge capacity of ∼60 mAh g-1, exhibiting superior rate performance. The significantly improved electrochemical performance of LiFePO4/C composites material can be attributed to its special micro-nano hierarchical structure. Microspheric LiFePO4/C composites exhibit a high tap density about 1.3 g cm-3. What's more, the well-coated carbon insures the high electrical conductivity and the nano-sized LiFePO4/C particles shorten lithium ion transport, thus exhibiting the high specific capacity, high cycling stability and good rate performance.

Three-dimensional hierarchical NiCo2O4 nanowire@Ni3S2 nanosheet core/shell arrays for flexible asymmetric supercapacitors

NASA Astrophysics Data System (ADS)

Liu, Bo; Kong, Dezhi; Huang, Zhi Xiang; Mo, Runwei; Wang, Ye; Han, Zhaojun; Cheng, Chuanwei; Yang, Hui Ying

2016-05-01

Three-dimensional (3D) hierarchical NiCo2O4@Ni3S2 core/shell arrays on Ni foam were synthesized by a facile, stepwise synthesis approach. The 3D heterogeneous NiCo2O4 nanostructure forms an interconnected web-like scaffold and serves as the core for the Ni3S2 shell. The as-prepared NiCo2O4@Ni3S2 nanowire array (NWA) electrodes exhibited excellent electrochemical performance, such as high specific areal capacitance and excellent cycling stability. The specific areal capacitance of 3.0 F cm-2 at a current density of 5 mA cm-2 is among the highest values and the only 6.7% capacitance decay after 10 000 cycles demonstrates the excellent cycling stability. A flexible asymmetric supercapacitor (ASC) was fabricated with activated carbon (AC) as the anode and the obtained NiCo2O4@Ni3S2 NWAs as the cathode. The ASC device exhibited a high energy density of 1.89 mW h cm-3 at 5.81 W cm-3 and a high power density of 56.33 W cm-3 at 0.94 mW h cm-3. As a result, the hybrid nanoarchitecture opens a new way to design high performance electrodes for electrochemical energy storage applications.Three-dimensional (3D) hierarchical NiCo2O4@Ni3S2 core/shell arrays on Ni foam were synthesized by a facile, stepwise synthesis approach. The 3D heterogeneous NiCo2O4 nanostructure forms an interconnected web-like scaffold and serves as the core for the Ni3S2 shell. The as-prepared NiCo2O4@Ni3S2 nanowire array (NWA) electrodes exhibited excellent electrochemical performance, such as high specific areal capacitance and excellent cycling stability. The specific areal capacitance of 3.0 F cm-2 at a current density of 5 mA cm-2 is among the highest values and the only 6.7% capacitance decay after 10 000 cycles demonstrates the excellent cycling stability. A flexible asymmetric supercapacitor (ASC) was fabricated with activated carbon (AC) as the anode and the obtained NiCo2O4@Ni3S2 NWAs as the cathode. The ASC device exhibited a high energy density of 1.89 mW h cm-3 at 5.81 W cm-3 and a high power density of 56.33 W cm-3 at 0.94 mW h cm-3. As a result, the hybrid nanoarchitecture opens a new way to design high performance electrodes for electrochemical energy storage applications. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr02600a

Nano-aggregates of cobalt nickel oxysulfide as a high-performance electrode material for supercapacitors.

PubMed

Liu, Lifeng

2013-12-07

Nano-aggregates of cobalt nickel oxysulfide (CoNi)OxSy have been synthesized by hydrothermal processing and exhibited specific and areal capacitance as high as 592 F g(-1) and 1628 mF cm(-2), respectively, at a current density of 0.5 A g(-1)/1.375 mA cm(-2). They also show high capacitance retention upon extended cycling at high rates.

A comparative study of the mechanical performance of Glass and Glass/Carbon hybrid polymer composites at different temperature environments

NASA Astrophysics Data System (ADS)

Shukla, M. J.; Kumar, D. S.; Mahato, K. K.; Rathore, D. K.; Prusty, R. K.; Ray, B. C.

2015-02-01

Glass Fiber Reinforced Polymer (GFRP) composites have been widely accepted as high strength, low weight structural material as compared to their metallic counterparts. Some specific advanced high performance applications such as aerospace components still require superior specific strength and specific modulus. Carbon Fiber Reinforced Polymer (CFRP) composites exhibit superior specific strength and modulus but have a lower failure strain and high cost. Hence, the combination of both glass and carbon fiber in polymer composite may yield optimized mechanical properties. Further the in-service environment has a significant role on the mechanical performance of this class of materials. Present study aims to investigate the mechanical property of GFRP and Glass/Carbon (G/C hybrid) composites at room temperature, in-situ and ex-situ temperature conditions. In-situ testing at +70°C and +100°C results in significant loss in inter-laminar shear strength (ILSS) for both the composites as compared to room temperature. The ILSS was nearly equal for both the composite systems tested in-situ at +100°C and effect of fiber hybridisation was completely diminished there. At low temperature ex-situ conditioning significant reduction in ILSS was observed for both the systems. Further at -60°C G/C hybrid exhibited 32.4 % higher ILSS than GFRP. Hence this makes G/C hybrid a better choice of material in low temperature environmental applications.

A new immunization procedure for the obtention of anti-leucine enkephalin antibodies. Part I. Immunization procedure and physicochemical characteristics of antibodies.

PubMed

Cupo, A; Vion-Dury, J; Jarry, T

1986-10-01

We described here a new immunization procedure to obtain high titre and high specific antibodies against Leu-enkephalin (LE). The immunogen form is composed of one part of LE conjugate and one part of LE-Arg6 conjugate. We have observed an increase of titre, affinity and specificity of the antibodies in the coimmunization procedure compared to those obtained by conventional immunization involving only the LE conjugate. The Leu-enkephalin antibodies exhibit a high affinity (KD 8 X 10(-12) M) and we are able to detect the Leu-enkephalin at the 10(-15) mole level. These LE antibodies are highly specific of the C part of LE peptide and cross-react weakly with Met-enkephalin (1%).

Electrochemical properties for high surface area and improved electrical conductivity of platinum-embedded porous carbon nanofibers

NASA Astrophysics Data System (ADS)

An, Geon-Hyoung; Ahn, Hyo-Jin; Hong, Woong-Ki

2015-01-01

Four different types of carbon nanofibers (CNFs) for electrical double-layer capacitors (EDLCs), porous and non-porous CNFs with and without Pt metal nanoparticles, are synthesized by an electrospinning method and their performance in electrical double-layer capacitors (EDLCs) is characterized. In particular, the Pt-embedded porous CNFs (PCNFs) exhibit a high specific surface area of 670 m2 g-1, a large mesopore volume of 55.7%, and a low electrical resistance of 1.7 × 103. The synergistic effects of the high specific surface area with a large mesopore volume, and superior electrical conductivity result in an excellent specific capacitance of 130.2 F g-1, a good high-rate performance, superior cycling durability, and high energy density of 16.9-15.4 W h kg-1 for the performance of EDLCs.

Carbon-Coated, Diatomite-Derived Nanosilicon as a High Rate Capable Li-ion Battery Anode.

PubMed

Campbell, Brennan; Ionescu, Robert; Tolchin, Maxwell; Ahmed, Kazi; Favors, Zachary; Bozhilov, Krassimir N; Ozkan, Cengiz S; Ozkan, Mihrimah

2016-10-07

Silicon is produced in a variety of ways as an ultra-high capacity lithium-ion battery (LIB) anode material. The traditional carbothermic reduction process required is expensive and energy-intensive; in this work, we use an efficient magnesiothermic reduction to convert the silica-based frustules within diatomaceous earth (diatomite, DE) to nanosilicon (nanoSi) for use as LIB anodes. Polyacrylic acid (PAA) was used as a binder for the DE-based nanoSi anodes for the first time, being attributed for the high silicon utilization under high current densities (up to 4C). The resulting nanoSi exhibited a high BET specific surface area of 162.6 cm 2 g -1 , compared to a value of 7.3 cm 2 g -1 for the original DE. DE contains SiO 2 architectures that make ideal bio-derived templates for nanoscaled silicon. The DE-based nanoSi anodes exhibit good cyclability, with a specific discharge capacity of 1102.1 mAh g -1 after 50 cycles at a C-rate of C/5 (0.7 A g Si -1 ) and high areal loading (2 mg cm -2 ). This work also demonstrates the fist rate capability testing for a DE-based Si anode; C-rates of C/30 - 4C were tested. At 4C (14.3 A g Si -1 ), the anode maintained a specific capacity of 654.3 mAh g -1 - nearly 2x higher than graphite's theoretical value (372 mAh g -1 ).

Nanomechanical Behavior of High Gas Barrier Multilayer Thin Films.

PubMed

Humood, Mohammad; Chowdhury, Shahla; Song, Yixuan; Tzeng, Ping; Grunlan, Jaime C; Polycarpou, Andreas A

2016-05-04

Nanoindentation and nanoscratch experiments were performed on thin multilayer films manufactured using the layer-by-layer (LbL) assembly technique. These films are known to exhibit high gas barrier, but little is known about their durability, which is an important feature for various packaging applications (e.g., food and electronics). Films were prepared from bilayer and quadlayer sequences, with varying thickness and composition. In an effort to evaluate multilayer thin film surface and mechanical properties, and their resistance to failure and wear, a comprehensive range of experiments were conducted: low and high load indentation, low and high load scratch. Some of the thin films were found to have exceptional mechanical behavior and exhibit excellent scratch resistance. Specifically, nanobrick wall structures, comprising montmorillonite (MMT) clay and polyethylenimine (PEI) bilayers, are the most durable coatings. PEI/MMT films exhibit high hardness, large elastic modulus, high elastic recovery, low friction, low scratch depth, and a smooth surface. When combined with the low oxygen permeability and high optical transmission of these thin films, these excellent mechanical properties make them good candidates for hard coating surface-sensitive substrates, where polymers are required to sustain long-term surface aesthetics and quality.

Development of Specifications for Engineered Cementitious Composites for Use in Bridge Deck Overlays

DOT National Transportation Integrated Search

2016-02-01

Engineered cementitious composite (ECC) material is a high strength, fiber-reinforced, ductile mortar mixture that can exhibit tensile strains of up to 5%. ECC has a dense matrix, giving the material exceptional durability characteristics. The durabi...

Porous Nanocomposite Comprising Ultralong Hydroxyapatite Nanowires Decorated with Zinc-Containing Nanoparticles and Chitosan: Synthesis and Application in Bone Defect Repair.

PubMed

Sun, Tuan-Wei; Yu, Wei-Lin; Zhu, Ying-Jie; Chen, Feng; Zhang, Yong-Gang; Jiang, Ying-Ying; He, Yao-Hua

2018-06-21

Hydroxyapatite nanowires exhibit a great potential in biomedical applications owing to their high specific surface area, high flexibility, excellent mechanical properties, and similarity to mineralized collagen fibrils of natural bone. In this work, zinc-containing nanoparticle-decorated ultralong hydroxyapatite nanowires (Zn-UHANWs) with a hierarchical nanostructure have been synthesized by a one-step solvothermal method. The highly flexible Zn-UHANWs exhibit a hierarchical rough surface and enhanced specific surface area as compared with ultralong hydroxyapatite nanowires (UHANWs). To evaluate the potential application of Zn-UHANWs in bone regeneration, the biomimetic Zn-UHANWs/chitosan (CS) (Zn-UHANWs/CS) composite porous scaffold with 80 wt % Zn-UHANWs was prepared by incorporating Zn-UHANWs into the chitosan matrix by the freeze-drying process. The as-prepared Zn-UHANWs/CS composite porous scaffold exhibits enhanced mechanical properties, highly porous structure, and excellent water retention capacity. In addition, the Zn-UHANWs/CS porous scaffold has a good biodegradability with the sustainable release of Zn, Ca, and P elements in aqueous solution. More importantly, the Zn-UHANWs/CS porous scaffold can promote the osteogenic differentiation of rat bone marrow derived mesenchymal stem cells and facilitate in vivo bone regeneration as compared with the pure CS porous scaffold or UHANWs/CS porous scaffold. Thus, both the Zn-UHANWs and Zn-UHANWs/CS porous scaffold developed in this work are promising for application in bone defect repair. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rapid detection of methicillin resistance in coagulase-negative staphylococci by a penicillin-binding protein 2a-specific latex agglutination test.

PubMed

Horstkotte, M A; Knobloch, J K; Rohde, H; Mack, D

2001-10-01

The detection of PBP 2a by the MRSA-Screen latex agglutination test with 201 clinical coagulase-negative staphylococci had an initial sensitivity of 98% and a high degree of specificity for Staphylococcus epidermidis strains compared to PCR for mecA. Determination of oxacillin MICs evaluated according to the new breakpoint (0.5 microg/ml) of the National Committee for Clinical Laboratory Standards exhibited an extremely low specificity for this population.

Fabrication of enzyme-degradable and size-controlled protein nanowires using single particle nano-fabrication technique

PubMed Central

Omichi, Masaaki; Asano, Atsushi; Tsukuda, Satoshi; Takano, Katsuyoshi; Sugimoto, Masaki; Saeki, Akinori; Sakamaki, Daisuke; Onoda, Akira; Hayashi, Takashi; Seki, Shu

2014-01-01

Protein nanowires exhibiting specific biological activities hold promise for interacting with living cells and controlling and predicting biological responses such as apoptosis, endocytosis and cell adhesion. Here we report the result of the interaction of a single high-energy charged particle with protein molecules, giving size-controlled protein nanowires with an ultra-high aspect ratio of over 1,000. Degradation of the human serum albumin nanowires was examined using trypsin. The biotinylated human serum albumin nanowires bound avidin, demonstrating the high affinity of the nanowires. Human serum albumin–avidin hybrid nanowires were also fabricated from a solid state mixture and exhibited good mechanical strength in phosphate-buffered saline. The biotinylated human serum albumin nanowires can be transformed into nanowires exhibiting a biological function such as avidin–biotinyl interactions and peroxidase activity. The present technique is a versatile platform for functionalizing the surface of any protein molecule with an extremely large surface area. PMID:24770668

MnO2 Nanorods Intercalating Graphene Oxide/Polyaniline Ternary Composites for Robust High-Performance Supercapacitors

NASA Astrophysics Data System (ADS)

Han, Guangqiang; Liu, Yun; Zhang, Lingling; Kan, Erjun; Zhang, Shaopeng; Tang, Jian; Tang, Weihua

2014-04-01

New ternary composites of MnO2 nanorods, polyaniline (PANI) and graphene oxide (GO) have been prepared by a two-step process. The 100 nm-long MnO2 nanorods with a diameter ~20 nm are conformably coated with PANI layers and fastened between GO layers. The MnO2 nanorods incorporated ternary composites electrode exhibits significantly increased specific capacitance than PANI/GO binary composite in supercapacitors. The ternary composite with 70% MnO2 exhibits a highest specific capacitance reaching 512 F/g and outstanding cycling performance, with ~97% capacitance retained over 5000 cycles. The ternary composite approach offers an effective solution to enhance the device performance of metal-oxide based supercapacitors for long cycling applications.

40 CFR 268.32 - Waste specific prohibitions-Soils exhibiting the toxicity characteristic for metals and...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 27 2011-07-01 2011-07-01 false Waste specific prohibitions-Soils... Prohibitions on Land Disposal § 268.32 Waste specific prohibitions—Soils exhibiting the toxicity characteristic... from land disposal: any volumes of soil exhibiting the toxicity characteristic solely because of the...

40 CFR 268.32 - Waste specific prohibitions-Soils exhibiting the toxicity characteristic for metals and...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 28 2013-07-01 2013-07-01 false Waste specific prohibitions-Soils... Prohibitions on Land Disposal § 268.32 Waste specific prohibitions—Soils exhibiting the toxicity characteristic... from land disposal: any volumes of soil exhibiting the toxicity characteristic solely because of the...

40 CFR 268.32 - Waste specific prohibitions-Soils exhibiting the toxicity characteristic for metals and...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 28 2012-07-01 2012-07-01 false Waste specific prohibitions-Soils... Prohibitions on Land Disposal § 268.32 Waste specific prohibitions—Soils exhibiting the toxicity characteristic... from land disposal: any volumes of soil exhibiting the toxicity characteristic solely because of the...

40 CFR 268.32 - Waste specific prohibitions-Soils exhibiting the toxicity characteristic for metals and...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Waste specific prohibitions-Soils... Prohibitions on Land Disposal § 268.32 Waste specific prohibitions—Soils exhibiting the toxicity characteristic... from land disposal: any volumes of soil exhibiting the toxicity characteristic solely because of the...

40 CFR 268.32 - Waste specific prohibitions-Soils exhibiting the toxicity characteristic for metals and...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 27 2014-07-01 2014-07-01 false Waste specific prohibitions-Soils... Prohibitions on Land Disposal § 268.32 Waste specific prohibitions—Soils exhibiting the toxicity characteristic... from land disposal: any volumes of soil exhibiting the toxicity characteristic solely because of the...

Cytomegalovirus-Specific CD8+ T-Cells With Different T-Cell Receptor Affinities Segregate T-Cell Phenotypes and Correlate With Chronic Graft-Versus-Host Disease in Patients Post-Hematopoietic Stem Cell Transplantation

PubMed Central

Poiret, Thomas; Axelsson-Robertson, Rebecca; Remberger, Mats; Luo, Xiao-Hua; Rao, Martin; Nagchowdhury, Anurupa; Von Landenberg, Anna; Ernberg, Ingemar; Ringden, Olle; Maeurer, Markus

2018-01-01

Virus-specific T-cell responses are crucial to control cytomegalovirus (CMV) infections/reactivation in immunocompromised individuals. Adoptive cellular therapy with CMV-specific T-cells has become a viable treatment option. High-affinity anti-viral cellular immune responses are associated with improved long-term immune protection against CMV infection. To date, the characterization of high-affinity T-cell responses against CMV has not been achieved in blood from patients after allogeneic hematopoietic stem cell transplantation (HSCT). Therefore, the purpose of this study was to describe and analyze the phenotype and clinical impact of different CMV-specific CD8+ cytotoxic T-lymphocytes (CMV-CTL) classes based on their T-cell receptor (TCR) affinity. T-cells isolated from 23 patients during the first year following HSCT were tested for the expression of memory markers, programmed cell death 1 (PD-1), as well as TCR affinity, using three different HLA-A*02:01 CMVNLVPMVATV-Pp65 tetramers (wild-type, a245v and q226a mutants). High-affinity CMV-CTL defined by q226a tetramer binding, exhibited a higher frequency in CD8+ T-cells in the first month post-HSCT and exhibited an effector memory phenotype associated with strong PD-1 expression as compared to the medium- and low-affinity CMV-CTLs. High-affinity CMV-CTL was found at higher proportion in patients with chronic graft-versus-host disease (p < 0.001). This study provides a first insight into the detailed TCR affinities of CMV-CTL. This may be useful in order to improve current immunotherapy protocols using isolation of viral-specific T-cell populations based on their TCR affinity. PMID:29692783

Few-layered MoSe2 nanosheets as an advanced electrode material for supercapacitors.

PubMed

Balasingam, Suresh Kannan; Lee, Jae Sung; Jun, Yongseok

2015-09-21

We report the synthesis of few-layered MoSe2 nanosheets using a facile hydrothermal method and their electrochemical charge storage behavior. A systematic study of the structure and morphology of the as-synthesized MoSe2 nanosheets was performed. The downward peak shift in the Raman spectrum and the high-resolution transmission electron microscopy images confirmed the formation of few-layered nanosheets. The electrochemical energy-storage behavior of MoSe2 nanosheets was also investigated for supercapacitor applications in a symmetric cell configuration. The MoSe2 nanosheet electrode exhibited a maximum specific capacitance of 198.9 F g(-1) and the symmetric device showed 49.7 F g(-1) at a scan rate of 2 mV s(-1). A capacitance retention of approximately 75% was observed even after 10 000 cycles at a high charge-discharge current density of 5 A g(-1). The two-dimensional MoSe2 nanosheets exhibited a high specific capacitance and good cyclic stability, which makes it a promising electrode material for supercapacitor applications.

Facilitated charge transport in ternary interconnected electrodes for flexible supercapacitors with excellent power characteristics.

PubMed

Chen, Wanjun; He, Yongmin; Li, Xiaodong; Zhou, Jinyuan; Zhang, Zhenxing; Zhao, Changhui; Gong, Chengshi; Li, Shuankui; Pan, Xiaojun; Xie, Erqing

2013-12-07

Flexible and high performance supercapacitors are very critical in modern society. In order to develop the flexible supercapacitors with high power density, free-standing and flexible three-dimensional graphene/carbon nanotubes/MnO2 (3DG/CNTs/MnO2) composite electrodes with interconnected ternary 3D structures were fabricated, and the fast electron and ion transport channels were effectively constructed in the rationally designed electrodes. Consequently, the obtained 3DG/CNTs/MnO2 composite electrodes exhibit superior specific capacitance and rate capability compared to 3DG/MnO2 electrodes. Furthermore, the 3DG/CNTs/MnO2 based asymmetric supercapacitor demonstrates the maximum energy and power densities of 33.71 W h kg(-1) and up to 22,727.3 W kg(-1), respectively. Moreover, the asymmetric supercapacitor exhibits excellent cycling stability with 95.3% of the specific capacitance maintained after 1000 cycle tests. Our proposed synthesis strategy to construct the novel ternary 3D structured electrodes can be efficiently applied to other high performance energy storage/conversion systems.

Facile Synthesis of Coaxial CNTs/MnOx-Carbon Hybrid Nanofibers and Their Greatly Enhanced Lithium Storage Performance.

PubMed

Yang, Zunxian; Lv, Jun; Pang, Haidong; Yan, Wenhuan; Qian, Kun; Guo, Tailiang; Guo, Zaiping

2015-12-01

Carbon nanotubes (CNTs)/MnOx-Carbon hybrid nanofibers have been successfully synthesized by the combination of a liquid chemical redox reaction (LCRR) and a subsequent carbonization heat treatment. The nanostructures exhibit a unique one-dimensional core/shell architecture, with one-dimensional CNTs encapsulated inside and a MnOx-carbon composite nanoparticle layer on the outside. The particular porous characteristics with many meso/micro holes/pores, the highly conductive one-dimensional CNT core, as well as the encapsulating carbon matrix on the outside of the MnOx nanoparticles, lead to excellent electrochemical performance of the electrode. The CNTs/MnOx-Carbon hybrid nanofibers exhibit a high initial reversible capacity of 762.9 mAhg(-1), a high reversible specific capacity of 560.5 mAhg(-1) after 100 cycles, and excellent cycling stability and rate capability, with specific capacity of 396.2 mAhg(-1) when cycled at the current density of 1000 mAg(-1), indicating that the CNTs/MnOx-Carbon hybrid nanofibers are a promising anode candidate for Li-ion batteries.

Facile Synthesis of Coaxial CNTs/MnOx-Carbon Hybrid Nanofibers and Their Greatly Enhanced Lithium Storage Performance

PubMed Central

Yang, Zunxian; Lv, Jun; Pang, Haidong; Yan, Wenhuan; Qian, Kun; Guo, Tailiang; Guo, Zaiping

2015-01-01

Carbon nanotubes (CNTs)/MnOx-Carbon hybrid nanofibers have been successfully synthesized by the combination of a liquid chemical redox reaction (LCRR) and a subsequent carbonization heat treatment. The nanostructures exhibit a unique one-dimensional core/shell architecture, with one-dimensional CNTs encapsulated inside and a MnOx-carbon composite nanoparticle layer on the outside. The particular porous characteristics with many meso/micro holes/pores, the highly conductive one-dimensional CNT core, as well as the encapsulating carbon matrix on the outside of the MnOx nanoparticles, lead to excellent electrochemical performance of the electrode. The CNTs/MnOx-Carbon hybrid nanofibers exhibit a high initial reversible capacity of 762.9 mAhg−1, a high reversible specific capacity of 560.5 mAhg−1 after 100 cycles, and excellent cycling stability and rate capability, with specific capacity of 396.2 mAhg−1 when cycled at the current density of 1000 mAg−1, indicating that the CNTs/MnOx-Carbon hybrid nanofibers are a promising anode candidate for Li-ion batteries. PMID:26621615

Faradic redox active material of Cu7S4 nanowires with a high conductance for flexible solid state supercapacitors

NASA Astrophysics Data System (ADS)

Javed, Muhammad Sufyan; Dai, Shuge; Wang, Mingjun; Xi, Yi; Lang, Qiang; Guo, Donglin; Hu, Chenguo

2015-08-01

The exploration of high Faradic redox active materials with the advantages of low cost and low toxicity has been attracting great attention for producing high energy storage supercapacitors. Here, the high Faradic redox active material of Cu7S4-NWs coated on a carbon fiber fabric (CFF) is directly used as a binder-free electrode for a high performance flexible solid state supercapacitor. The Cu7S4-NW-CFF supercapacitor exhibits excellent electrochemical performance such as a high specific capacitance of 400 F g-1 at the scan rate of 10 mV s-1 and a high energy density of 35 Wh kg-1 at a power density of 200 W kg-1, with the advantages of a light weight, high flexibility and long term cycling stability by retaining 95% after 5000 charge-discharge cycles at a constant current of 10 mA. The high Faradic redox activity and high conductance behavior of the Cu7S4-NWs result in a high pseudocapacitive performance with a relatively high specific energy and specific power. Such a new type of pseudocapacitive material of Cu7S4-NWs with its low cost is very promising for actual application in supercapacitors.The exploration of high Faradic redox active materials with the advantages of low cost and low toxicity has been attracting great attention for producing high energy storage supercapacitors. Here, the high Faradic redox active material of Cu7S4-NWs coated on a carbon fiber fabric (CFF) is directly used as a binder-free electrode for a high performance flexible solid state supercapacitor. The Cu7S4-NW-CFF supercapacitor exhibits excellent electrochemical performance such as a high specific capacitance of 400 F g-1 at the scan rate of 10 mV s-1 and a high energy density of 35 Wh kg-1 at a power density of 200 W kg-1, with the advantages of a light weight, high flexibility and long term cycling stability by retaining 95% after 5000 charge-discharge cycles at a constant current of 10 mA. The high Faradic redox activity and high conductance behavior of the Cu7S4-NWs result in a high pseudocapacitive performance with a relatively high specific energy and specific power. Such a new type of pseudocapacitive material of Cu7S4-NWs with its low cost is very promising for actual application in supercapacitors. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr03363b

High Detectivity Graphene-Silicon Heterojunction Photodetector.

PubMed

Li, Xinming; Zhu, Miao; Du, Mingde; Lv, Zheng; Zhang, Li; Li, Yuanchang; Yang, Yao; Yang, Tingting; Li, Xiao; Wang, Kunlin; Zhu, Hongwei; Fang, Ying

2016-02-03

A graphene/n-type silicon (n-Si) heterojunction has been demonstrated to exhibit strong rectifying behavior and high photoresponsivity, which can be utilized for the development of high-performance photodetectors. However, graphene/n-Si heterojunction photodetectors reported previously suffer from relatively low specific detectivity due to large dark current. Here, by introducing a thin interfacial oxide layer, the dark current of graphene/n-Si heterojunction has been reduced by two orders of magnitude at zero bias. At room temperature, the graphene/n-Si photodetector with interfacial oxide exhibits a specific detectivity up to 5.77 × 10(13) cm Hz(1/2) W(-1) at the peak wavelength of 890 nm in vacuum, which is highest reported detectivity at room temperature for planar graphene/Si heterojunction photodetectors. In addition, the improved graphene/n-Si heterojunction photodetectors possess high responsivity of 0.73 A W(-1) and high photo-to-dark current ratio of ≈10(7) . The current noise spectral density of the graphene/n-Si photodetector has been characterized under ambient and vacuum conditions, which shows that the dark current can be further suppressed in vacuum. These results demonstrate that graphene/Si heterojunction with interfacial oxide is promising for the development of high detectivity photodetectors. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High Per formance and Flexible Supercapacitors based on Carbonized Bamboo Fibers for Wide Temperature Applications

PubMed Central

Zequine, Camila; Ranaweera, C. K.; Wang, Z.; Singh, Sweta; Tripathi, Prashant; Srivastava, O. N.; Gupta, Bipin Kumar; Ramasamy, K.; Kahol, P. K.; Dvornic, P. R.; Gupta, Ram K.

2016-01-01

High performance carbonized bamboo fibers were synthesized for a wide range of temperature dependent energy storage applications. The structural and electrochemical properties of the carbonized bamboo fibers were studied for flexible supercapacitor applications. The galvanostatic charge-discharge studies on carbonized fibers exhibited specific capacity of ~510F/g at 0.4 A/g with energy density of 54 Wh/kg. Interestingly, the carbonized bamboo fibers displayed excellent charge storage stability without any appreciable degradation in charge storage capacity over 5,000 charge-discharge cycles. The symmetrical supercapacitor device fabricated using these carbonized bamboo fibers exhibited an areal capacitance of ~1.55 F/cm2 at room temperature. In addition to high charge storage capacity and cyclic stability, the device showed excellent flexibility without any degradation to charge storage capacity on bending the electrode. The performance of the supercapacitor device exhibited ~65% improvement at 70 °C compare to that at 10 °C. Our studies suggest that carbonized bamboo fibers are promising candidates for stable, high performance and flexible supercapacitor devices. PMID:27546225

High Per formance and Flexible Supercapacitors based on Carbonized Bamboo Fibers for Wide Temperature Applications.

PubMed

Zequine, Camila; Ranaweera, C K; Wang, Z; Singh, Sweta; Tripathi, Prashant; Srivastava, O N; Gupta, Bipin Kumar; Ramasamy, K; Kahol, P K; Dvornic, P R; Gupta, Ram K

2016-08-22

High performance carbonized bamboo fibers were synthesized for a wide range of temperature dependent energy storage applications. The structural and electrochemical properties of the carbonized bamboo fibers were studied for flexible supercapacitor applications. The galvanostatic charge-discharge studies on carbonized fibers exhibited specific capacity of ~510F/g at 0.4 A/g with energy density of 54 Wh/kg. Interestingly, the carbonized bamboo fibers displayed excellent charge storage stability without any appreciable degradation in charge storage capacity over 5,000 charge-discharge cycles. The symmetrical supercapacitor device fabricated using these carbonized bamboo fibers exhibited an areal capacitance of ~1.55 F/cm(2) at room temperature. In addition to high charge storage capacity and cyclic stability, the device showed excellent flexibility without any degradation to charge storage capacity on bending the electrode. The performance of the supercapacitor device exhibited ~65% improvement at 70 °C compare to that at 10 °C. Our studies suggest that carbonized bamboo fibers are promising candidates for stable, high performance and flexible supercapacitor devices.

High Per formance and Flexible Supercapacitors based on Carbonized Bamboo Fibers for Wide Temperature Applications

NASA Astrophysics Data System (ADS)

Zequine, Camila; Ranaweera, C. K.; Wang, Z.; Singh, Sweta; Tripathi, Prashant; Srivastava, O. N.; Gupta, Bipin Kumar; Ramasamy, K.; Kahol, P. K.; Dvornic, P. R.; Gupta, Ram K.

2016-08-01

High performance carbonized bamboo fibers were synthesized for a wide range of temperature dependent energy storage applications. The structural and electrochemical properties of the carbonized bamboo fibers were studied for flexible supercapacitor applications. The galvanostatic charge-discharge studies on carbonized fibers exhibited specific capacity of ~510F/g at 0.4 A/g with energy density of 54 Wh/kg. Interestingly, the carbonized bamboo fibers displayed excellent charge storage stability without any appreciable degradation in charge storage capacity over 5,000 charge-discharge cycles. The symmetrical supercapacitor device fabricated using these carbonized bamboo fibers exhibited an areal capacitance of ~1.55 F/cm2 at room temperature. In addition to high charge storage capacity and cyclic stability, the device showed excellent flexibility without any degradation to charge storage capacity on bending the electrode. The performance of the supercapacitor device exhibited ~65% improvement at 70 °C compare to that at 10 °C. Our studies suggest that carbonized bamboo fibers are promising candidates for stable, high performance and flexible supercapacitor devices.

Silencing and heterologous expression of ppo-2 indicate a specific function of a single polyphenol oxidase isoform in resistance of dandelion (Taraxacum officinale) against Pseudomonas syringae pv. tomato.

PubMed

Richter, Carolin; Dirks, Mareike E; Gronover, Christian Schulze; Prüfer, Dirk; Moerschbacher, Bruno M

2012-02-01

Dandelion (Taraxacum officinale) possesses an unusually high degree of disease resistance. As this plant exhibits high polyphenol oxidase (PPO) activity and PPO have been implicated in resistance against pests and pathogens, we analyzed the potential involvement of five PPO isoenzymes in the resistance of dandelion against Botrytis cinerea and Pseudomonas syringae pv. tomato. Only one PPO (ppo-2) was induced during infection, and ppo-2 promoter and β-glucuronidase marker gene fusions revealed strong induction of the gene surrounding lesions induced by B. cinerea. Specific RNAi silencing reduced ppo-2 expression only, and concomitantly increased plant susceptibility to P. syringae pv. tomato. At 4 days postinoculation, P. syringae pv. tomato populations were strongly increased in the ppo-2 RNAi lines compared with wild-type plants. When the dandelion ppo-2 gene was expressed in Arabidopsis thaliana, a plant having no PPO gene, active protein was formed and protein extracts of the transgenic plants exhibited substrate-dependent antimicrobial activity against P. syringae pv. tomato. These results clearly indicate a strong contribution of a specific, single PPO isoform to disease resistance. Therefore, we propose that specific PPO isoenzymes be included in a new family of pathogenesis-related (PR) proteins.

A novel and facile synthesis approach for a porous carbon/graphene composite for high-performance supercapacitors.

PubMed

Liu, Ting; Zhang, Xuesha; Liu, Kang; Liu, Yanyan; Liu, Mengjie; Wu, Wenyu; Gu, Yu; Zhang, Ruijun

2018-03-02

We propose a novel and facile synthesis approach to a porous carbon/graphene composite. Graphene is obtained from room-temperature expanded graphite (RTEG), not involving the use of graphite oxide (GO). Porous carbon is acquired by carbonization and KOH-activation of polyvinylpyrrolidone (PVP), which is used to exfoliate RTEG into graphene and inhibit the restacking of the resultant graphene in the present work. The prepared porous carbon/graphene composite has a high specific surface area (SSA) (3008 m 2 g -1 ) and a hierarchical micro- and meso- pore structure (dominant pores in the range of 1-5 nm). Electrochemical measurement demonstrates that the as-prepared porous carbon/graphene composite can deliver an outstanding specific capacitance of up to 340 F g -1 at 5 mV s -1 in 6 M KOH electrolyte. This specific capacitance is among the highest reported so far for porous carbon/graphene materials. Moreover, the prepared composite as an electrode material also exhibits excellent cycling stability (94.4% capacitance retention over 10 000 cycles). The as-fabricated symmetrical supercapacitor exhibits a high energy density of 10.9 W h kg -1 (based on total mass of electrode materials) and an outstanding energy density retention, even at high power density. Compared with conventional preparation routes for porous carbon/graphene composites, the present approach is significantly simple, convenient and cost-effective, which will make it more competent in the development of electrode materials for high-performance supercapacitors.

Supercapacitors based on nitrogen-doped reduced graphene oxide and borocarbonitrides

NASA Astrophysics Data System (ADS)

Gopalakrishnan, K.; Moses, Kota; Govindaraj, A.; Rao, C. N. R.

2013-12-01

Nitrogen-doped reduced graphene oxide (RGO) samples with different nitrogen content, prepared by two different methods, as well as nitrogen-doped few-layer graphene have been investigated as supercapacitor electrodes. Two electrode measurements have been carried out both in aqueous (6M KOH) and in ionic liquid media. Nitrogen-doped reduced graphene oxides exhibit satisfactory specific capacitance, the values reaching 126F/g at a scan rate of 10mV/s in aqueous medium. Besides providing supercapacitor characteristics, the study has shown the nitrogen content and surface area to be important factors. High surface-area borocarbonitrides, BxCyNz, prepared by the urea route appear to be excellent supercapacitor electrode materials. Thus, BC4.5N exhibits a specific capacitance of 169F/g at a scan rate of 10mV/s in aqueous medium. In an ionic liquid medium, nitrogen-doped RGO and BC4.5N exhibit specific capacitance values of 258F/g and 240F/g at a scan rate of 5mV/s. The ionic liquid enables a larger operating voltage range of 0.0-2.5V compared to 0.0-1V in aqueous medium.

Species-Specific and Drug-Specific Differences in Susceptibility of Candida Biofilms to Echinocandins: Characterization of Less Common Bloodstream Isolates

PubMed Central

Simitsopoulou, Maria; Peshkova, Pavla; Tasina, Efthymia; Katragkou, Aspasia; Kyrpitzi, Daniela; Velegraki, Aristea; Walsh, Thomas J.

2013-01-01

Candida species other than Candida albicans are increasingly recognized as causes of biofilm-associated infections. This is a comprehensive study that compared the in vitro activities of all three echinocandins against biofilms formed by different common and infrequently identified Candida isolates. We determined the activities of anidulafungin (ANID), caspofungin (CAS), and micafungin (MFG) against planktonic cells and biofilms of bloodstream isolates of C. albicans (15 strains), Candida parapsilosis (6 strains), Candida lusitaniae (16 strains), Candida guilliermondii (5 strains), and Candida krusei (12 strains) by XTT [2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] assay. Planktonic and biofilm MICs were defined as ≥50% fungal damage. Planktonic cells of all Candida species were susceptible to the three echinocandins, with MICs of ≤1 mg/liter. By comparison, differences in the MIC profiles of biofilms in response to echinocandins existed among the Candida species. Thus, C. lusitaniae and C. guilliermondii biofilms were highly recalcitrant to all echinocandins, with MICs of ≥32 mg/liter. In contrast, the MICs of all three echinocandins for C. albicans and C. krusei biofilms were relatively low (MICs ≤ 1 mg/liter). While echinocandins exhibited generally high MICs against C. parapsilosis biofilms, MFG exhibited the lowest MICs against these isolates (4 mg/liter). A paradoxical growth effect was observed with CAS concentrations ranging from 8 to 64 mg/liter against C. albicans and C. parapsilosis biofilms but not against C. krusei, C. lusitaniae, or C. guilliermondii. While non-albicans Candida planktonic cells were susceptible to all echinocandins, there were drug- and species-specific differences in susceptibility among biofilms of the various Candida species, with C. lusitaniae and C. guilliermondii exhibiting profiles of high MICs of the three echinocandins. PMID:23529739

Synthesis of Multifunctional Nanoparticles for Cancer Diagnostics and Therapeutics

NASA Astrophysics Data System (ADS)

Fang, Chen

2011-12-01

Magnetic nanoparticles (MNPs) have attracted enormous research attention due to their unique magnetic properties that enable the detection by the non-invasive medical imaging modality---magnetic resonance imaging (MRI). By incorporating advanced features, such as specific targeting, multimodality, therapeutic delivery, the detectability and applicability of MNPs have been dramatically expanded. Smart and rational design on structure, composition and surface chemistry is essential to achieving desired properties in MNP systems, such as high sensitivity and colloidal stability, target specificity and/or multimodality. The goal of this research is to develop MNP-based platforms for the detection, diagnosis and treatment of cancer. MNPs with high contrast enhancement were coated with poly(ethylene glycol) (PEG)-based polymers to render aqueous stability and confer therapeutic-loading capability. Tumor-specific MNPs were developed by functionalization of nanoparticles with chlorotoxin (CTX) or arginine-glycine-aspartic acid (RGD) that targets, respectively, MMP-2 receptor or alphavbeta3 integrin overexpressed on a variety of cancer cells. The effects of ligands' molecular targets on the temporal and spatial distribution of MNPs within tumors were also investigated both in vitro and in vivo. All MNPs exhibited excellent long-term stability in cell culture media. CTX-labeled MNP exhibited sustained accumulation, penetration and distribution in the tumor mass. These findings revealed the influence of the targeting ligands on the intratumoral distribution of the ligand-enabled nanoprobes. To demonstrate the ability of nanoparticles as drug carrier, anthracyline chemotherapeutic drugs doxorubicin and mitoxantrone were attached to iron oxide nanoparticles. The theragnostic nanoparticles showed sufficient contrast enhancement and comparable anti-neoplastic efficacy in vitro. With flexible surface chemistry, our nanoparticle platform can be used in a modular fashion to conjugate biomolecules for intended applications, and the functionalized nanoparticle systems retain a prolonged stability and exhibit high tumor specificity. The study would establish the foundation for future development of integrated theragnostic systems for the treatment of cancer and other complex diseases.

Metaphor Comprehension in Autistic Spectrum Disorders: Case Studies of Two High-Functioning Children

ERIC Educational Resources Information Center

Melogno, Sergio; D'Ardia, Caterina; Pinto, Maria Antonietta; Levi, Gabriel

2012-01-01

This article presents case studies on metaphor comprehension in two boys with high-functioning autistic spectrum disorder, aged 9;1 (9 years, 1 month) and 8;11. The participants were assessed twice, before and after an intervention program aimed at improving their social skills. The focus of the article is on the specific patterns exhibited by…

Ultrafine manganese dioxide nanowire network for high-performance supercapacitors.

PubMed

Jiang, Hao; Zhao, Ting; Ma, Jan; Yan, Chaoyi; Li, Chunzhong

2011-01-28

Ultrafine MnO(2) nanowires with sub-10 nm diameters have been synthesized by a simple process of hydrothermal treatment with subsequent calcinations to form networks that exhibit an enhanced specific capacitance (279 F g(-1) at 1 A g(-1)), high rate capability (54.5% retention at 20 A g(-1)) and good cycling stability (1.7% loss after 1000 cycles).

Encapsulation of Fe3O4 Nanoparticles into N, S co-Doped Graphene Sheets with Greatly Enhanced Electrochemical Performance

PubMed Central

Yang, Zunxian; Qian, Kun; Lv, Jun; Yan, Wenhuan; Liu, Jiahui; Ai, Jingwei; Zhang, Yuxiang; Guo, Tailiang; Zhou, Xiongtu; Xu, Sheng; Guo, Zaiping

2016-01-01

Particular N, S co-doped graphene/Fe3O4 hybrids have been successfully synthesized by the combination of a simple hydrothermal process and a subsequent carbonization heat treatment. The nanostructures exhibit a unique composite architecture, with uniformly dispersed Fe3O4 nanoparticles and N, S co-doped graphene encapsulant. The particular porous characteristics with many meso/micro holes/pores, the highly conductive N, S co-doped graphene, as well as the encapsulating N, S co-doped graphene with the high-level nitrogen and sulfur doping, lead to excellent electrochemical performance of the electrode. The N-S-G/Fe3O4 composite electrode exhibits a high initial reversible capacity of 1362.2 mAhg−1, a high reversible specific capacity of 1055.20 mAhg−1 after 100 cycles, and excellent cycling stability and rate capability, with specific capacity of 556.69 mAhg−1 when cycled at the current density of 1000 mAg−1, indicating that the N-S-G/Fe3O4 composite is a promising anode candidate for Li-ion batteries. PMID:27296103

Plant-produced anti-dengue virus monoclonal antibodies exhibit reduced antibody-dependent enhancement of infection activity.

PubMed

Dent, Matthew; Hurtado, Jonathan; Paul, Amber M; Sun, Haiyan; Lai, Huafang; Yang, Ming; Esqueda, Adrian; Bai, Fengwei; Steinkellner, Herta; Chen, Qiang

2016-12-01

The mAb E60 has the potential to be a desirable therapeutic molecule since it efficiently neutralizes all four serotypes of dengue virus (DENV). However, mammalian-cell-produced E60 exhibits antibody-dependent enhancement of infection (ADE) activity, rendering it inefficacious in vivo, and treated animals more susceptible to developing more severe diseases during secondary infection. In this study, we evaluated a plant-based expression system for the production of therapeutically suitable E60. The mAb was transiently expressed in Nicotiana benthamianaWT and a ∆XFT line, a glycosylation mutant lacking plant-specific N-glycan residues. The mAb was efficiently expressed and assembled in leaves and exhibited highly homogenous N-glycosylation profiles, i.e. GnGnXF3 or GnGn structures, depending on the expression host. Both E60 glycovariants demonstrated equivalent antigen-binding specificity and in vitro neutralization potency against DENV serotypes 2 and 4 compared with their mammalian-cell-produced counterpart. By contrast, plant-produced E60 exhibited reduced ADE activity in Fc gamma receptor expressing human cells. Our results suggest the ability of plant-produced antibodies to minimize ADE, which may lead to the development of safe and highly efficacious antibody-based therapeutics against DENV and other ADE-prone viral diseases. Our study provides so far unknown insight into the relationship between mAb N-glycosylation and ADE, which contributes to our understanding of how sugar moieties of antibodies modulate Fc-mediated functions and viral pathogenesis.

Psathyrella velutina Mushroom Lectin Exhibits High Affinity toward Sialoglycoproteins Possessing Terminal N-Acetylneuraminic Acid alpha 2,3-Linked to Penultimate Galactose Residues of Trisialyl N-Glycans. Comparison with other sialic acid-specific lectins.

PubMed

Ueda, Haruko; Matsumoto, Hanako; Takahashi, Noriko; Ogawa, Haruko

2002-07-12

A lectin from the fruiting body of the Psathyrella velutina mushroom (PVL) was found to bind specifically to N-acetylneuraminic acid, as well as to GlcNAc (Ueda, H., Kojima, K., Saitoh, T., and Ogawa, H. (1999) FEBS Lett. 448, 75-80). In this study, the glycan sequences that PVL recognizes with high affinity on sialoglycoproteins were revealed. Among sialic acid-specific lectins only PVL could reveal the sialylated N-acetyllactosamine structure of glycoproteins in blotting studies, based on the dual specificity. The affinity of PVL to fetuin was measured by surface plasmon resonance to be 10(7) m(-1), which is an order of magnitude higher than those of Sambucus nigra agglutinin and Maackia amurensis mitogen, whereas affinity to asialofetuin was approximately 0 and to asialo-agalactofetuin was 10(8) m(-1), suggesting that PVL exhibits remarkably high affinities toward glycoproteins possessing trisialo- or GlcNAc-exposed glycans. Transferrin was separated into fractions that correspond to the sialylation states on an immobilized PVL column. Transferrin-possessing trisialoglycans containing alpha2,3-linked N-acetylneuraminic acid on the beta1,4-linked GlcNAc branch bound to the PVL column and eluted with GlcNAc; those containing only alpha2,6-linked sialic acids were retarded, whereas other transferrin fractions passed through the column. These results indicate that PVL is a lectin with potential for separation and detection of sialoglycoproteins because of its dual specificity toward sialoglycans and GlcNAc exposed glycans.

Autoantibodies against Modified Histone Peptides in SLE Patients Are Associated with Disease Activity and Lupus Nephritis

PubMed Central

Dieker, Jürgen; Berden, Jo H.; Bakker, Marinka; Briand, Jean-Paul; Muller, Sylviane; Voll, Reinhard; Sjöwall, Christopher; Herrmann, Martin; Hilbrands, Luuk B.; van der Vlag, Johan

2016-01-01

Persistent exposure of the immune system to death cell debris leads to autoantibodies against chromatin in patients with systemic lupus erythematosus (SLE). Deposition of anti-chromatin/chromatin complexes can instigate inflammation in multiple organs including the kidney. Previously we identified specific cell death-associated histone modifications as targets of autoantibodies in SLE. In this study we addressed, in a large cohort of SLE patients and controls, the question whether plasma reactivities with specific histone peptides associated with serology and clinical features. Plasma from SLE patients with and without lupus nephritis, disease controls, and healthy controls, were tested in ELISA with histone H4 peptide acetylated at lysines 8, 12 and 16 (H4pac), H2B peptide acetylated at lysine 12 (H2Bpac), H3 peptide trimethylated at lysine 27 (H3pme), and their unmodified equivalents. SLE patients displayed a higher reactivity with the modified equivalent of each peptide. Reactivity with H4pac showed both a high sensitivity (89%) and specificity (91%) for SLE, while H2Bpac exhibited a high specificity (96%) but lower sensitivity (69%). Reactivity with H3pme appeared not specific for SLE. Anti-H4pac and anti-H2Bpac reactivity demonstrated a high correlation with disease activity. Moreover, patients reacting with multiple modified histone peptides exhibited higher SLEDAI and lower C3 levels. SLE patients with renal involvement showed higher reactivity with H2B/H2Bpac and a more pronounced reactivity with the modified equivalent of H3pme and H2Bpac. In conclusion, reactivity with H4pac and H2Bpac is specific for SLE patients and correlates with disease activity, whereas reactivity with H2Bpac is in particular associated with lupus nephritis. PMID:27780265

A porous carbon material from pyrolysis of fructus cannabis’s shells for supercapacitor electrode application

NASA Astrophysics Data System (ADS)

Li, Kai; Zhang, Wei-Bin; Zhao, Zhi-Yun; Zhao, Yue; Chen, Xi-Wen; Kong, Ling-Bin

2018-02-01

The porous carbon material is obtained via pyrolysis and activation of fructus cannabis’s shells, an easy-to-get biomass source, and is used as an active electrode material for supercapacitors. The obtained carbon exhibit a high specific surface area of 2389 m2 g-1. And the result of x-ray photoelectron spectroscopy (XPS) shows that the obtained porous carbon possess numerous oxygen groups, which can facilitate the wettability of the electrode. The prepared porous carbon also exhibit remarkable electrochemical properties, such as high specific capacitance of 357 F g-1 at a current density of 0.5 A g-1 in 6 mol L-1 aqueous KOH electrolyte, good rate capability of 77% capacitance retention as the current density increase from 0.5 A g-1 to 10 A g-1. In addition, it also presents a superior cycling stability of 100% capacitance retention after 10 000 cycles at the current density of 1 A g-1.

Design of a serotonin 4 receptor radiotracer with decreased lipophilicity for single photon emission computed tomography.

PubMed

Fresneau, Nathalie; Dumas, Noé; Tournier, Benjamin B; Fossey, Christine; Ballandonne, Céline; Lesnard, Aurélien; Millet, Philippe; Charnay, Yves; Cailly, Thomas; Bouillon, Jean-Philippe; Fabis, Frédéric

2015-04-13

With the aim to develop a suitable radiotracer for the brain imaging of the serotonin 4 receptor subtype (5-HT4R) using single photon emission computed tomography (SPECT), we synthesized and evaluated a library of di- and triazaphenanthridines with lipophilicity values which were in the range expected to favour brain penetration, and which demonstrated specific binding to the target of interest. Adding additional nitrogen atoms to previously described phenanthridine ligands exhibiting a high unspecific binding, we were able to design a radioiodinated compound [(125)I]14. This compound exhibited a binding affinity value of 0.094 nM toward human 5-HT4R and a high selectivity over other serotonin receptor subtypes (5-HTR). In vivo SPECT imaging studies and competition experiments demonstrated that the decreased lipophilicity (in comparison with our previously reported compounds 4 and 5) allowed a more specific labelling of the 5-HT4R brain-containing regions. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Burn-Resistant, Strong Metal-Matrix Composites

NASA Technical Reports Server (NTRS)

Stoltzfus, Joel M.; Tayal, Moti J.

2003-01-01

Ceramic particulate fillers increase the specific strengths and burn resistances of metals: This is the conclusion drawn by researchers at Johnson Space Center's White Sands Test Facility. The researchers had theorized that the inclusion of ceramic particles in metal tools and other metal objects used in oxygen-rich atmospheres (e.g., in hyperbaric chambers and spacecraft) could reduce the risk of fire and the consequent injury or death of personnel. In such atmospheres, metal objects act as ignition sources, creating fire hazards. However, not all metals are equally hazardous: some are more burn-resistant than others are. It was the researchers purpose to identify a burn-resistant, high-specific-strength ceramic-particle/metal-matrix composite that could be used in oxygen-rich atmospheres. The researchers studied several metals. Nickel and cobalt alloys exhibit high burn resistances and are dense. The researchers next turned to ceramics, which they knew do not act as ignition sources. Unlike metals, ceramics are naturally burn-resistant. Unfortunately, they also exhibit low fracture toughnesses.

Synthesis of belt-like BiOBr hierarchical nanostructure with high photocatalytic performance

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

Li, Haiping; Liu, Jingyi; Hu, Tingxia

2016-05-15

Highlights: • BiOBr hierarchical nanobelts (NBs) were solvothermally prepared. • NBs show higher specific surface area and photoabsorption than BiOBr nanosheets. • NBs exhibit higher photoactivity than the nanosheets. - Abstract: One-dimensional (1D) bismuth oxyhalide (BiOX) hierarchical nanostructures are always difficult to prepare. Herein, we report, for the first time, a simple synthesis of BiOBr nanobelts (NBs) via a facile solvothermal route, using bismuth subsalicylate as the template and bismuth source. The BiOBr nanobelts are composed of irregular single crystal nanoparticles with highly exposed (0 1 0) facets. Compared with the BiOBr nanosheets (NSs) with dominant exposed (0 0 1)more » facets, they exhibit higher photocatalytic activity toward degradation of Rhodamine B and Methylene Blue under visible light irradiation. The higher photocatalytic performance of BiOBr NBs arises from their larger specific surface area and higher photoabsorption capability. This study provides a simple route for synthesis of belt-like Bi-based hierarchical nanostructures.« less

Mechanical properties of carbon fibre-reinforced polymer/magnesium alloy hybrid laminates

NASA Astrophysics Data System (ADS)

Zhou, Pengpeng; Wu, Xuan; Pan, Yingcai; Tao, Ye; Wu, Guoqing; Huang, Zheng

2018-04-01

In this study, we prepared fibre metal laminates (FMLs) consisting of high-modulus carbon fibre-reinforced polymer (CFRP) prepregs and thin AZ31 alloy sheets by using hot-pressing technology. Tensile and low-velocity impact tests were performed to evaluate the mechanical properties and fracture behaviour of the magnesium alloy-based FMLs (Mg-FMLs) and to investigate the differences in the fracture behaviour between the Mg-FMLs and traditional Mg-FMLs. Results show that the Mg-FMLs exhibit higher specific tensile strength and specific tensile modulus than traditional Mg-FMLs and that the tensile behaviour of the Mg-FMLs is mainly governed by the CFRP because of the combination of high interlaminar shear properties and thin magnesium alloy layers. The Mg-FMLs exhibit excellent bending stiffness. Hence, no significant difference between the residual displacement d r and indentation depth d i , and the permanent deformation is mainly limited to a small zone surrounding the impact location after the impact tests.

Engineering Polymer Nanocomoposite Aerogels for Energy Storage and Harvesting

NASA Astrophysics Data System (ADS)

Zheng, Qifeng

Various porous polymer nanocomposite aerogels were synthesized using an environmentally friendly freeze-drying process. These polymer nanocomposite aerogels exhibit ultralow densities, high porosities, high specific surface areas and high flexibility. The advantages of these polymer nanocomposites aerogels for energy storage and energy harvesting applications have been demonstrated. Flexible supercapacitors (SCs) are particularly attractive for energy storage applications due to their high power densities and long life cycles. A novel type of highly flexible and all-solid-state SCs using cellulose nanofibril (CNF)-reduced graphene oxide (RGO)-carbon nanotube (CNT) aerogels as electrodes was developed. Due to the porous structure of the CNF/RGO/CNT aerogel electrodes, and the excellent electrolyte absorption properties of the CNFs present in the electrodes, the resulting all-solid-state SCs exhibited excellent electrochemical performance, superior flexibility and cycle stability. To further increase the capacitances and energy densities, pseudocapacitive materials (i.e., MoO3) were incorporated to prepare the free-standing and highly flexible CNF-RGO-molybdenum oxynitride (MoOxNy) aerogel film electrode. Supercapacitors made with the CNF/RGO/MoOxNy aerogel electrodes exhibited outstanding specific capacitances and remarkable energy densities in different electrolytes while maintaining the high power densities and superior cycle stability. Flexible nanogenerators (NGs) that can harvest ubiquitous mechanical energy from ambient environments have attracted significant attention during the past decade. A novel, simple, cost-effective, and scalable technique was developed to fabricate high-performance flexible compact NGs using porous CNF-poly(dimethylsiloxane) (PDMS) aerogel film. Under external stress, the resulting NGs exhibited very stable and high output signals. We hypothesized that the remarkable electric outputs would not only be attributable to the intrinsic piezoelectric properties of the CNFs, but also to the mechanoradicals generated by the porous PDMS coated on the surface of the CNF aerogel film, which can lead to a change in the electric dipole moments and consequently generate electric outputs. A series of systematic studies were carried out to substantiate this new mechanism. These systematic studies have demonstrated that high-performance NGs can be made from porous mechanoradical-generating polymer films. The elucidation of the mechanisms for this family of porous mechanoradical-generating polymers will lead to a new class of energy harvesting materials and high-performance flexible energy generation devices.

An Approach to Preparing Ni-P with Different Phases for Use as Supercapacitor Electrode Materials.

PubMed

Wang, Dan; Kong, Ling-Bin; Liu, Mao-Cheng; Luo, Yong-Chun; Kang, Long

2015-12-01

Herein, we describe a simple two-step approach to prepare nickel phosphide with different phases, such as Ni2 P and Ni5 P4 , to explain the influence of material microstructure and electrical conductivity on electrochemical performance. In this approach, we first prepared a Ni-P precursor through a ball milling process, then controlled the synthesis of either Ni2 P or Ni5 P4 by the annealing method. The as-prepared Ni2 P and Ni5 P4 are investigated as supercapacitor electrode materials for potential energy storage applications. The Ni2 P exhibits a high specific capacitance of 843.25 F g(-1) , whereas the specific capacitance of Ni5 P4 is 801.5 F g(-1) . Ni2 P possesses better cycle stability and rate capability than Ni5 P4 . In addition, the Fe2 O3 //Ni2 P supercapacitor displays a high energy density of 35.5 Wh kg(-1) at a power density of 400 W kg(-1) and long cycle stability with a specific capacitance retention rate of 96 % after 1000 cycles, whereas the Fe2 O3 //Ni5 P4 supercapacitor exhibits a high energy density of 29.8 Wh kg(-1) at a power density of 400 W kg(-1) and a specific capacitance retention rate of 86 % after 1000 cycles. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High-performance solid-state supercapacitors based on graphene-ZnO hybrid nanocomposites.

PubMed

Li, Zijiong; Zhou, Zhihua; Yun, Gaoqian; Shi, Kai; Lv, Xiaowei; Yang, Baocheng

2013-11-12

In this paper, we report a facile low-cost synthesis of the graphene-ZnO hybrid nanocomposites for solid-state supercapacitors. Structural analysis revealed a homogeneous distribution of ZnO nanorods that are inserted in graphene nanosheets, forming a sandwiched architecture. The material exhibited a high specific capacitance of 156 F g-1 at a scan rate of 5 mV.s-1. The fabricated solid-state supercapacitor device using these graphene-ZnO hybrid nanocomposites exhibits good supercapacitive performance and long-term cycle stability. The improved supercapacitance property of these materials could be ascribed to the increased conductivity of ZnO and better utilization of graphene. These results demonstrate the potential of the graphene-ZnO hybrid nanocomposites as an electrode in high-performance supercapacitors.

High-performance solid-state supercapacitors based on graphene-ZnO hybrid nanocomposites

NASA Astrophysics Data System (ADS)

Li, Zijiong; Zhou, Zhihua; Yun, Gaoqian; Shi, Kai; Lv, Xiaowei; Yang, Baocheng

2013-11-01

In this paper, we report a facile low-cost synthesis of the graphene-ZnO hybrid nanocomposites for solid-state supercapacitors. Structural analysis revealed a homogeneous distribution of ZnO nanorods that are inserted in graphene nanosheets, forming a sandwiched architecture. The material exhibited a high specific capacitance of 156 F g-1 at a scan rate of 5 mV.s-1. The fabricated solid-state supercapacitor device using these graphene-ZnO hybrid nanocomposites exhibits good supercapacitive performance and long-term cycle stability. The improved supercapacitance property of these materials could be ascribed to the increased conductivity of ZnO and better utilization of graphene. These results demonstrate the potential of the graphene-ZnO hybrid nanocomposites as an electrode in high-performance supercapacitors.

High-performance solid-state supercapacitors based on graphene-ZnO hybrid nanocomposites

PubMed Central

2013-01-01

In this paper, we report a facile low-cost synthesis of the graphene-ZnO hybrid nanocomposites for solid-state supercapacitors. Structural analysis revealed a homogeneous distribution of ZnO nanorods that are inserted in graphene nanosheets, forming a sandwiched architecture. The material exhibited a high specific capacitance of 156 F g−1 at a scan rate of 5 mV.s−1. The fabricated solid-state supercapacitor device using these graphene-ZnO hybrid nanocomposites exhibits good supercapacitive performance and long-term cycle stability. The improved supercapacitance property of these materials could be ascribed to the increased conductivity of ZnO and better utilization of graphene. These results demonstrate the potential of the graphene-ZnO hybrid nanocomposites as an electrode in high-performance supercapacitors. PMID:24215772

Multiscale mechanical integrity of human supraspinatus tendon in shear after elastin depletion.

PubMed

Fang, Fei; Lake, Spencer P

2016-10-01

Human supraspinatus tendon (SST) exhibits region-specific nonlinear mechanical properties under tension, which have been attributed to its complex multiaxial physiological loading environment. However, the mechanical response and underlying multiscale mechanism regulating SST behavior under other loading scenarios are poorly understood. Furthermore, little is known about the contribution of elastin to tendon mechanics. We hypothesized that (1) SST exhibits region-specific shear mechanical properties, (2) fiber sliding is the predominant mode of local matrix deformation in SST in shear, and (3) elastin helps maintain SST mechanical integrity by facilitating force transfer among collagen fibers. Through the use of biomechanical testing and multiphoton microscopy, we measured the multiscale mechanical behavior of human SST in shear before and after elastase treatment. Three distinct SST regions showed similar stresses and microscale deformation. Collagen fiber reorganization and sliding were physical mechanisms observed as the SST response to shear loading. Measures of microscale deformation were highly variable, likely due to a high degree of extracellular matrix heterogeneity. After elastase treatment, tendon exhibited significantly decreased stresses under shear loading, particularly at low strains. These results show that elastin contributes to tendon mechanics in shear, further complementing our understanding of multiscale tendon structure-function relationships. Copyright © 2016 Elsevier Ltd. All rights reserved.

Carbon-Coated, Diatomite-Derived Nanosilicon as a High Rate Capable Li-ion Battery Anode

PubMed Central

Campbell, Brennan; Ionescu, Robert; Tolchin, Maxwell; Ahmed, Kazi; Favors, Zachary; Bozhilov, Krassimir N.; Ozkan, Cengiz S.; Ozkan, Mihrimah

2016-01-01

Silicon is produced in a variety of ways as an ultra-high capacity lithium-ion battery (LIB) anode material. The traditional carbothermic reduction process required is expensive and energy-intensive; in this work, we use an efficient magnesiothermic reduction to convert the silica-based frustules within diatomaceous earth (diatomite, DE) to nanosilicon (nanoSi) for use as LIB anodes. Polyacrylic acid (PAA) was used as a binder for the DE-based nanoSi anodes for the first time, being attributed for the high silicon utilization under high current densities (up to 4C). The resulting nanoSi exhibited a high BET specific surface area of 162.6 cm2 g−1, compared to a value of 7.3 cm2 g−1 for the original DE. DE contains SiO2 architectures that make ideal bio-derived templates for nanoscaled silicon. The DE-based nanoSi anodes exhibit good cyclability, with a specific discharge capacity of 1102.1 mAh g−1 after 50 cycles at a C-rate of C/5 (0.7 A gSi−1) and high areal loading (2 mg cm−2). This work also demonstrates the fist rate capability testing for a DE-based Si anode; C-rates of C/30 - 4C were tested. At 4C (14.3 A gSi−1), the anode maintained a specific capacity of 654.3 mAh g−1 – nearly 2x higher than graphite’s theoretical value (372 mAh g−1). PMID:27713474

Carbon-Coated, Diatomite-Derived Nanosilicon as a High Rate Capable Li-ion Battery Anode

NASA Astrophysics Data System (ADS)

Campbell, Brennan; Ionescu, Robert; Tolchin, Maxwell; Ahmed, Kazi; Favors, Zachary; Bozhilov, Krassimir N.; Ozkan, Cengiz S.; Ozkan, Mihrimah

2016-10-01

Silicon is produced in a variety of ways as an ultra-high capacity lithium-ion battery (LIB) anode material. The traditional carbothermic reduction process required is expensive and energy-intensive; in this work, we use an efficient magnesiothermic reduction to convert the silica-based frustules within diatomaceous earth (diatomite, DE) to nanosilicon (nanoSi) for use as LIB anodes. Polyacrylic acid (PAA) was used as a binder for the DE-based nanoSi anodes for the first time, being attributed for the high silicon utilization under high current densities (up to 4C). The resulting nanoSi exhibited a high BET specific surface area of 162.6 cm2 g-1, compared to a value of 7.3 cm2 g-1 for the original DE. DE contains SiO2 architectures that make ideal bio-derived templates for nanoscaled silicon. The DE-based nanoSi anodes exhibit good cyclability, with a specific discharge capacity of 1102.1 mAh g-1 after 50 cycles at a C-rate of C/5 (0.7 A gSi-1) and high areal loading (2 mg cm-2). This work also demonstrates the fist rate capability testing for a DE-based Si anode; C-rates of C/30 - 4C were tested. At 4C (14.3 A gSi-1), the anode maintained a specific capacity of 654.3 mAh g-1 - nearly 2x higher than graphite’s theoretical value (372 mAh g-1).

MnO2 Nanorods Intercalating Graphene Oxide/Polyaniline Ternary Composites for Robust High-Performance Supercapacitors

PubMed Central

Han, Guangqiang; Liu, Yun; Zhang, Lingling; Kan, Erjun; Zhang, Shaopeng; Tang, Jian; Tang, Weihua

2014-01-01

New ternary composites of MnO2 nanorods, polyaniline (PANI) and graphene oxide (GO) have been prepared by a two-step process. The 100 nm-long MnO2 nanorods with a diameter ~20 nm are conformably coated with PANI layers and fastened between GO layers. The MnO2 nanorods incorporated ternary composites electrode exhibits significantly increased specific capacitance than PANI/GO binary composite in supercapacitors. The ternary composite with 70% MnO2 exhibits a highest specific capacitance reaching 512 F/g and outstanding cycling performance, with ~97% capacitance retained over 5000 cycles. The ternary composite approach offers an effective solution to enhance the device performance of metal-oxide based supercapacitors for long cycling applications. PMID:24769835

Activated carbon derived from harmful aquatic plant for high stable supercapacitors

NASA Astrophysics Data System (ADS)

Li, Jiangfeng; Wu, Qingsheng

2018-01-01

Considering cost and environmental protection, the harmful aquatic plant altemanthera philoxeroides derived carbon material with super high specific surface area (2895 m2 g-1) is an ideal electrode material for supercapacitor. The structure and composition of these carbon materials were characterized by SEM, EDS, XPS and BET measurements. The obtained material exhibits a maximum specific capacitance of 275 F g-1 at 0.5 A g-1 and retains a capacitance of 210 F g-1 even at 50 A g-1. In addition, it also shows excellent capacity retention of 5000 cycles at 10 A g-1.

A HIGHLY SELECTIVE PCR PROTOCOL FOR DETECTING 16S RRNA GENES OF THE GENUS PSEUDOMONAS (SENSU STRICTO) IN ENVIRONMENTAL SAMPLES

EPA Science Inventory

Pseudomonas species are plant, animal, and human pathogens; exhibit plant pathogen-suppressing properties useful in biological control; or express metabolic versatilities valued in biotechnology and bioremediation. Specific detection of Pseudomonas species in the environment may ...

Design of aqueous redox-enhanced electrochemical capacitors with high specific energies and slow self-discharge.

PubMed

Chun, Sang-Eun; Evanko, Brian; Wang, Xingfeng; Vonlanthen, David; Ji, Xiulei; Stucky, Galen D; Boettcher, Shannon W

2015-08-04

Electrochemical double-layer capacitors exhibit high power and long cycle life but have low specific energy compared with batteries, limiting applications. Redox-enhanced capacitors increase specific energy by using redox-active electrolytes that are oxidized at the positive electrode and reduced at the negative electrode during charging. Here we report characteristics of several redox electrolytes to illustrate operational/self-discharge mechanisms and the design rules for high performance. We discover a methyl viologen (MV)/bromide electrolyte that delivers a high specific energy of ∼14 Wh kg(-1) based on the mass of electrodes and electrolyte, without the use of an ion-selective membrane separator. Substituting heptyl viologen for MV increases stability, with no degradation over 20,000 cycles. Self-discharge is low, due to adsorption of the redox couples in the charged state to the activated carbon, and comparable to cells with inert electrolyte. An electrochemical model reproduces experiments and predicts that 30-50 Wh kg(-1) is possible with optimization.

Design of aqueous redox-enhanced electrochemical capacitors with high specific energies and slow self-discharge

PubMed Central

Chun, Sang-Eun; Evanko, Brian; Wang, Xingfeng; Vonlanthen, David; Ji, Xiulei; Stucky, Galen D.; Boettcher, Shannon W.

2015-01-01

Electrochemical double-layer capacitors exhibit high power and long cycle life but have low specific energy compared with batteries, limiting applications. Redox-enhanced capacitors increase specific energy by using redox-active electrolytes that are oxidized at the positive electrode and reduced at the negative electrode during charging. Here we report characteristics of several redox electrolytes to illustrate operational/self-discharge mechanisms and the design rules for high performance. We discover a methyl viologen (MV)/bromide electrolyte that delivers a high specific energy of ∼14 Wh kg−1 based on the mass of electrodes and electrolyte, without the use of an ion-selective membrane separator. Substituting heptyl viologen for MV increases stability, with no degradation over 20,000 cycles. Self-discharge is low, due to adsorption of the redox couples in the charged state to the activated carbon, and comparable to cells with inert electrolyte. An electrochemical model reproduces experiments and predicts that 30–50 Wh kg−1 is possible with optimization. PMID:26239891

A facile synthesis of reduced holey graphene oxide for supercapacitors.

PubMed

Hu, Xinjun; Bai, Dongchen; Wu, Yiqi; Chen, Songbo; Ma, Yu; Lu, Yue; Chao, Yuanzhi; Bai, Yongxiao

2017-12-12

Hydroxyl radicals (˙OH) generated from a UV/O 3 solution reaction is used to efficiently etch graphene oxide nanosheets under moderate conditions. Reduced holey graphene oxide is directly used as a supercapacitor electrode material and exhibits high specific capacitance (224 F g -1 at a current density of 1 A g -1 ) and high volumetric capacitance (up to 206 F cm -3 ).

Sodium-Ion Batteries: Improving the Rate Capability of 3D Interconnected Carbon Nanofibers Thin Film by Boron, Nitrogen Dual-Doping.

PubMed

Wang, Min; Yang, Yang; Yang, Zhenzhong; Gu, Lin; Chen, Qianwang; Yu, Yan

2017-04-01

Boron, nitrogen dual-doping 3D hard carbon nanofibers thin film is synthesized using a facile process. The nanofibers exhibit high specific capacity and remarkable high-rate capability due to the synergistic effect of 3D porous structure, large surface area, and enlarged carbon layer spacing, and the B, N codoping-induced defects.

Immunological metagene signatures derived from immunogenic cancer cell death associate with improved survival of patients with lung, breast or ovarian malignancies: A large-scale meta-analysis

PubMed Central

Garg, Abhishek D.; De Ruysscher, Dirk; Agostinis, Patrizia

2016-01-01

ABSTRACT The emerging role of the cancer cell-immune cell interface in shaping tumorigenesis/anticancer immunotherapy has increased the need to identify prognostic biomarkers. Henceforth, our primary aim was to identify the immunogenic cell death (ICD)-derived metagene signatures in breast, lung and ovarian cancer that associate with improved patient survival. To this end, we analyzed the prognostic impact of differential gene-expression of 33 pre-clinically-validated ICD-parameters through a large-scale meta-analysis involving 3,983 patients (‘discovery’ dataset) across lung (1,432), breast (1,115) and ovarian (1,436) malignancies. The main results were also substantiated in ‘validation’ datasets consisting of 818 patients of same cancer-types (i.e. 285 breast/274 lung/259 ovarian). The ICD-associated parameters exhibited a highly-clustered and largely cancer type-specific prognostic impact. Interestingly, we delineated ICD-derived consensus-metagene signatures that exhibited a positive prognostic impact that was either cancer type-independent or specific. Importantly, most of these ICD-derived consensus-metagenes (acted as attractor-metagenes and thereby) ‘attracted’ highly co-expressing sets of genes or convergent-metagenes. These convergent-metagenes also exhibited positive prognostic impact in respective cancer types. Remarkably, we found that the cancer type-independent consensus-metagene acted as an ‘attractor’ for cancer-specific convergent-metagenes. This reaffirms that the immunological prognostic landscape of cancer tends to segregate between cancer-independent and cancer-type specific gene signatures. Moreover, this prognostic landscape was largely dominated by the classical T cell activity/infiltration/function-related biomarkers. Interestingly, each cancer type tended to associate with biomarkers representing a specific T cell activity or function rather than pan-T cell biomarkers. Thus, our analysis confirms that ICD can serve as a platform for discovery of novel prognostic metagenes. PMID:27057433

Wearable high-performance supercapacitors based on Ni-coated cotton textile with low-crystalline Ni-Al layered double hydroxide nanoparticles.

PubMed

Lu, Haicui; Chen, Jizhang; Tian, Qinghua

2018-03-01

Wearable electronics are developing rapidly in recent years. In this work, we develop a cost-effective, facile, and scalable approach to transform insulating cotton textile to highly conductive Ni-coated cotton textile (NCT). In order to verify the feasibility of NCT as a flexible current collector for wearable supercapacitors, we electrodeposit low-crystalline Ni-Al layered double hydroxide (LDH) nanoparticles onto the NCT. The obtained NCT@NiAl-LDH shows high specific capacitance (935.2 mF cm -2 ), superior rate capability, and good cyclability. Besides, the asymmetric supercapacitor (ASC) assembled from NCT@NiAl-LDH exhibits high specific energy of 58.8 Wh kg -1 (134 μWh cm -2 ) when the specific power is 539 W kg -1 (1228 μW cm -2 ). The results demonstrate great potential of our methodology. Copyright © 2017 Elsevier Inc. All rights reserved.

Post-growth process for flexible CdS/CdTe thin film solar cells with high specific power.

PubMed

Cho, Eunwoo; Kang, Yoonmook; Kim, Donghwan; Kim, Jihyun

2016-05-16

We demonstrated a flexible CdS/CdTe thin film solar cell with high specific power of approximately 254 W/kg. A flexible and ultra-light weight CdS/CdTe cell treated with pre-NP etch process exhibited high conversion efficiency of 13.56% in superstrate configuration. Morphological, structural and optical changes of CdS/CdTe thin films were characterized when pre-NP etch step was incorporated to the conventional post-deposition process. Improvement of photovoltaic parameters can be attributed to the removal of the oxide and the formation of Te-rich layer, which benefit the activation process. Pre-NP etched cell maintained their flexibility and performance under the repeated tensile strain of 0.13%. Our method can pave a way for manufacturing flexible CdS/CdTe thin film solar cells with high specific power for mobile and aerospace applications.

Flash visual evoked potentials are not specific enough to identify parieto-occipital lobe involvement in term neonates after significant hypoglycaemia.

PubMed

Hu, Liyuan; Gu, Qiufang; Zhu, Zhen; Yang, Chenhao; Chen, Chao; Cao, Yun; Zhou, Wenhao

2014-08-01

Hypoglycaemia is a significant problem in high-risk neonates and predominant parieto-occipital lobe involvement has been observed after severe hypoglycaemic insult. We explored the use of flash visual evoked potentials (FVEP) in detecting parieto-occipital lobe involvement after significant hypoglycaemia. Full-term neonates (n = 15) who underwent FVEP from January 2008 to May 2013 were compared with infants (n = 11) without hypoglycaemia or parietal-occipital lobe injury. Significant hypoglycaemia was defined as being symptomatic or needing steroids, glucagon or a glucose infusion rate of ≥12 mg/kg/min. The hypoglycaemia group exhibited delayed latency of the first positive waveform on FVEP. The initial detected time for hypoglycaemia was later in the eight subjects with seizures (median 51-h-old) than those without (median 22-h-old) (P = 0.003). Magnetic resonance imaging showed that 80% of the hypoglycaemia group exhibited occipital-lobe injuries, and they were more likely to exhibit abnormal FVEP morphology (P = 0.007) than the controls. FVEP exhibited 100% sensitivity, but only 25% specificity, for detecting injuries to the parieto-occipital lobes. Flash visual evoked potential (FVEP) was sensitive, but not sufficiently specific, in identifying parieto-occipital lobe injuries among term neonates exposed to significant hypoglycaemia. Larger studies exploring the potential role of FVEP in neonatal hypoglycaemia are required. ©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Biologically derived melanin electrodes in aqueous sodium-ion energy storage devices

PubMed Central

Kim, Young Jo; Wu, Wei; Chun, Sang-Eun; Whitacre, Jay F.; Bettinger, Christopher J.

2013-01-01

Biodegradable electronics represents an attractive and emerging paradigm in medical devices by harnessing simultaneous advantages afforded by electronically active systems and obviating issues with chronic implants. Integrating practical energy sources that are compatible with the envisioned operation of transient devices is an unmet challenge for biodegradable electronics. Although high-performance energy storage systems offer a feasible solution, toxic materials and electrolytes present regulatory hurdles for use in temporary medical devices. Aqueous sodium-ion charge storage devices combined with biocompatible electrodes are ideal components to power next-generation biodegradable electronics. Here, we report the use of biologically derived organic electrodes composed of melanin pigments for use in energy storage devices. Melanins of natural (derived from Sepia officinalis) and synthetic origin are evaluated as anode materials in aqueous sodium-ion storage devices. Na+-loaded melanin anodes exhibit specific capacities of 30.4 ± 1.6 mAhg−1. Full cells composed of natural melanin anodes and λ-MnO2 cathodes exhibit an initial potential of 1.03 ± 0.06 V with a maximum specific capacity of 16.1 ± 0.8 mAhg−1. Natural melanin anodes exhibit higher specific capacities compared with synthetic melanins due to a combination of beneficial chemical, electrical, and physical properties exhibited by the former. Taken together, these results suggest that melanin pigments may serve as a naturally occurring biologically derived charge storage material to power certain types of medical devices. PMID:24324163

Facile synthesis of hierarchical mesoporous weirds-like morphological MnO2 thin films on carbon cloth for high performance supercapacitor application.

PubMed

Shinde, Pragati A; Lokhande, Vaibhav C; Ji, Taeksoo; Lokhande, Chandrakant D

2017-07-15

The mesoporous nanostructured metal oxides have a lot of capabilities to upsurge the energy storing capacity of the supercapacitor. In present work, different nanostructured morphologies of MnO 2 have been successfully fabricated on flexible carbon cloth by simple but capable hydrothermal method at different deposition temperatures. The deposition temperature has strong influence on reaction kinetics, which subsequently alters the morphology and electrochemical performance. Among different nanostructured MnO 2 thin films, the mesoporous weirds composed thin film obtained at temperature of 453K exhibits excellent physical and electrochemical features for supercapacitor application. The weirds composed MnO 2 thin film exhibits specific surface area of 109m 2 g -1 , high specific capacitance of 595Fg -1 with areal capacitance of 4.16Fcm -2 at a scan rate of 5mVs -1 and high specific energy of 56.32Whkg -1 . In addition to this, MnO 2 weirds attain capacity retention of 87 % over 2000 CV cycles, representing better cycling stability. The enhanced electrochemical performance could be ascribed to direct growth of highly porous MnO 2 weirds on carbon cloth which provide more pathways for easy diffusion of electrolyte into the interior of electroactive material. The as-fabricated electrode with improved performance could be ascribed as a potential electrode material for energy storage devices. Copyright © 2017 Elsevier Inc. All rights reserved.

Mo-doped SnO2 mesoporous hollow structured spheres as anode materials for high-performance lithium ion batteries

NASA Astrophysics Data System (ADS)

Wang, Xuekun; Li, Zhaoqiang; Zhang, Zhiwei; Li, Qun; Guo, Enyan; Wang, Chengxiang; Yin, Longwei

2015-02-01

We designed a facile infiltration route to synthesize mesoporous hollow structured Mo doped SnO2 using silica spheres as templates. It is observed that Mo is uniformly incorporated into SnO2 lattice in the form of Mo6+. The as-prepared mesoporous Mo-doped SnO2 LIBs anodes exhibit a significantly improved electrochemical performance with good cycling stability, high specific capacity and high rate capability. The mesoporous hollow Mo-doped SnO2 sample with 14 at% Mo doping content displays a specific capacity of 801 mA h g-1 after 60 cycles at a current density of 100 mA g-1, about 1.66 times higher than that of the pure SnO2 hollow sample. In addition, even if the current density is as high as 1600 mA g-1 after 60 cycles, it could still retain a stable specific capacity of 530 mA h g-1, exhibiting an extraordinary rate capability. The greatly improved electrochemical performance of the Mo-doped mesoporous hollow SnO2 sample could be attributed to the following factors. The large surface area and hollow structure can significantly enhance structural integrity by acting as mechanical buffer, effectively alleviating the volume changes generated during the lithiation/delithiation process. The incorporation of Mo into the lattice of SnO2 improves charge transfer kinetics and results in a faster Li+ diffusion rate during the charge-discharge process.

Novel gadopentetic acid-doped silica nanoparticles conjugated with YPSMA-1 targeting prostate cancer for MR imaging: an in vitro study.

PubMed

Jiang, Wei; He, Xiaojing; Fang, Huiying; Zhou, Xue; Ran, Haitao; Guo, Dajing

2018-05-05

The early diagnosis of prostate cancer (PCa) is particularly important for reducing its high mortality rate. With the development of molecular magnetic resonance imaging (MRI), early diagnosis via non-invasive imaging has become possible. In this study, gadopentetic acid (GA)-doped silica (Gd@SiO 2 ) was first synthesized by a reverse microemulsion method, and amino and carboxyl groups were then successively introduced onto the surface of this Gd@SiO 2 . After these steps, a monoclonal antibody (YPSMA-1) to prostate-specific membrane antigen (PSMA) was conjugated with carboxyl-modified Gd@SiO 2 (Gd@SiO 2 -COOH) nanoparticles (NPs) by the carbodiimide method. Gd@SiO 2 -Ab NPs were thus obtained as specific MR contrast agents for PCa-targeted imaging. Transmission electron microscopy showed that the Gd@SiO 2 -Ab NPs exhibited a dispersed spherical morphology with a relatively uniform size distribution. The Gd@SiO 2 -Ab NPs showed high stability and high the longitudinal relaxation rate (r 1 ). Cell-targeting experiments in vitro demonstrated the high potential of the synthesized NPs to target PSMA receptor-positive PCa cells. In vitro cytotoxicity assays showed that the Gd@SiO 2 -Ab NPs exhibited good biological safety. These results suggest that the synthesized Gd@SiO 2 -Ab NPs have great potential as specific MR contrast agents for PSMA receptor-positive PCa cells. Copyright © 2018 Elsevier Inc. All rights reserved.

Three dimensional nitrogen-doped graphene aerogels functionalized with melamine for multifunctional applications in supercapacitors and adsorption

NASA Astrophysics Data System (ADS)

Xing, Ling-Bao; Hou, Shu-Fen; Zhou, Jin; Zhang, Jing-Li; Si, Weijiang; Dong, Yunhui; Zhuo, Shuping

2015-10-01

In present work, we demonstrate an efficient and facile strategy to fabricate three-dimensional (3D) nitrogen-doped graphene aerogels (NGAs) based on melamine, which serves as reducing and functionalizing agent of graphene oxide (GO) in an aqueous medium with ammonia. Benefiting from well-defined and cross-linked 3D porous network architectures, the supercapacitor based on the NGAs exhibited a high specific capacitance of 170.5 F g-1 at 0.2 A g-1, and this capacitance also showed good electrochemical stability and a high degree of reversibility in the repetitive charge/discharge cycling test. More interestingly, the prepared NGAs further exhibited high adsorption capacities and high recycling performance toward several metal ions such as Pb2+, Cu2+ and Cd2+. Moreover, the hydrophobic carbonized nitrogen-doped graphene aerogels (CNGAs) showed outstanding adsorption and recycling performance for the removal of various oils and organic solvents.

High-performance supercapacitors of Cu-based porous coordination polymer nanowires and the derived porous CuO nanotubes.

PubMed

Wu, Meng-Ke; Zhou, Jiao-Jiao; Yi, Fei-Yan; Chen, Chen; Li, Yan-Li; Li, Qin; Tao, Kai; Han, Lei

2017-12-12

Electrode materials for supercapacitors with one-dimensional porous nanostructures, such as nanowires and nanotubes, are very attractive for high-efficiency storage of electrochemical energy. Herein, ultralong Cu-based porous coordination polymer nanowires (copper-l-aspartic acid) were used as the electrode material for supercapacitors, for the first time. The as-prepared material exhibits a high specific capacitance of 367 F g -1 at 0.6 A g -1 and excellent cycling stability (94% retention over 1000 cycles). Moreover, porous CuO nanotubes were successfully fabricated by the thermal decomposition of this nanowire precursor. The CuO nanotube exhibits good electrochemical performance with high rate capacity (77% retention at 12.5 A g -1 ) and long-term stability (96% retention over 1000 cycles). The strategy developed here for the synthesis of porous nanowires and nanotubes can be extended to the construction of other electrode materials for more efficient energy storage.

Mitochondrial Dysfunction Plus High-Sugar Diet Provokes a Metabolic Crisis That Inhibits Growth.

PubMed

Kemppainen, Esko; George, Jack; Garipler, Görkem; Tuomela, Tea; Kiviranta, Essi; Soga, Tomoyoshi; Dunn, Cory D; Jacobs, Howard T

2016-01-01

The Drosophila mutant tko25t exhibits a deficiency of mitochondrial protein synthesis, leading to a global insufficiency of respiration and oxidative phosphorylation. This entrains an organismal phenotype of developmental delay and sensitivity to seizures induced by mechanical stress. We found that the mutant phenotype is exacerbated in a dose-dependent fashion by high dietary sugar levels. tko25t larvae were found to exhibit severe metabolic abnormalities that were further accentuated by high-sugar diet. These include elevated pyruvate and lactate, decreased ATP and NADPH. Dietary pyruvate or lactate supplementation phenocopied the effects of high sugar. Based on tissue-specific rescue, the crucial tissue in which this metabolic crisis initiates is the gut. It is accompanied by down-regulation of the apparatus of cytosolic protein synthesis and secretion at both the RNA and post-translational levels, including a novel regulation of S6 kinase at the protein level.

Mitochondrial Dysfunction Plus High-Sugar Diet Provokes a Metabolic Crisis That Inhibits Growth

PubMed Central

Kemppainen, Esko; George, Jack; Garipler, Görkem; Tuomela, Tea; Kiviranta, Essi; Soga, Tomoyoshi; Dunn, Cory D.; Jacobs, Howard T.

2016-01-01

The Drosophila mutant tko25t exhibits a deficiency of mitochondrial protein synthesis, leading to a global insufficiency of respiration and oxidative phosphorylation. This entrains an organismal phenotype of developmental delay and sensitivity to seizures induced by mechanical stress. We found that the mutant phenotype is exacerbated in a dose-dependent fashion by high dietary sugar levels. tko25t larvae were found to exhibit severe metabolic abnormalities that were further accentuated by high-sugar diet. These include elevated pyruvate and lactate, decreased ATP and NADPH. Dietary pyruvate or lactate supplementation phenocopied the effects of high sugar. Based on tissue-specific rescue, the crucial tissue in which this metabolic crisis initiates is the gut. It is accompanied by down-regulation of the apparatus of cytosolic protein synthesis and secretion at both the RNA and post-translational levels, including a novel regulation of S6 kinase at the protein level. PMID:26812173

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

Xing, Ling-Bao; Hou, Shu-Fen; Zhou, Jin

In present work, we demonstrate an efficient and facile strategy to fabricate three-dimensional (3D) nitrogen-doped graphene aerogels (NGAs) based on melamine, which serves as reducing and functionalizing agent of graphene oxide (GO) in an aqueous medium with ammonia. Benefiting from well-defined and cross-linked 3D porous network architectures, the supercapacitor based on the NGAs exhibited a high specific capacitance of 170.5 F g{sup −1} at 0.2 A g{sup −1}, and this capacitance also showed good electrochemical stability and a high degree of reversibility in the repetitive charge/discharge cycling test. More interestingly, the prepared NGAs further exhibited high adsorption capacities and highmore » recycling performance toward several metal ions such as Pb{sup 2+}, Cu{sup 2+} and Cd{sup 2+}. Moreover, the hydrophobic carbonized nitrogen-doped graphene aerogels (CNGAs) showed outstanding adsorption and recycling performance for the removal of various oils and organic solvents. - Graphical abstract: Three-dimensional nitrogen-doped graphene aerogels were prepared by using melamine as reducing and functionalizing agent in an aqueous medium with ammonia, which showed multifunctional applications in supercapacitors and adsorption. - Highlights: • Three-dimensional nitrogen-doped graphene aerogels (NGAs) were prepared. • Melamine was used as reducing and functionalizing agent. • NGAs exhibited relatively good electrochemical properties in supercapacitor. • NGAs exhibited high adsorption performance toward several metal ions. • CNGAs showed outstanding adsorption capacities for various oils and solvents.« less

Electron-band theory inspired design of magnesium-precious metal bulk metallic glasses with high thermal stability and extended ductility.

PubMed

Laws, Kevin J; Shamlaye, Karl F; Granata, Davide; Koloadin, Leah S; Löffler, Jörg F

2017-06-13

Magnesium-based bulk metallic glasses (BMGs) exhibit high specific strengths and excellent glass-forming ability compared to other metallic systems, making them suitable candidates for next-generation materials. However, current Mg-based BMGs tend to exhibit low thermal stability and are prone to structural relaxation and brittle failure. This study presents a range of new magnesium-precious metal-based BMGs from the ternary Mg-Ag-Ca, Mg-Ag-Yb, Mg-Pd-Ca and Mg-Pd-Yb alloy systems with Mg content greater than 67 at.%. These alloys were designed for high ductility by utilising atomic bond-band theory and a topological efficient atomic packing model. BMGs from the Mg-Pd-Ca alloy system exhibit high glass-forming ability with critical casting sizes of up to 3 mm in diameter, the highest glass transition temperatures (>200 °C) of any reported Mg-based BMG to date, and sustained compressive ductility. Alloys from the Mg-Pd-Yb family exhibit critical casting sizes of up to 4 mm in diameter, and the highest compressive plastic (1.59%) and total (3.78%) strain to failure of any so far reported Mg-based glass. The methods and theoretical approaches presented here demonstrate a significant step forward in the ongoing development of this extraordinary class of materials.

High energy density supercapacitors from lignin derived submicron activated carbon fibers in aqueous electrolytes

NASA Astrophysics Data System (ADS)

Hu, Sixiao; Zhang, Sanliang; Pan, Ning; Hsieh, You-Lo

2014-12-01

Highly porous submicron activated carbon fibers (ACFs) were robustly generated from low sulfonated alkali lignin and fabricated into supercapacitors for capacitive energy storage. The hydrophilic and high specific surface ACFs exhibited large-size nanographites and good electrical conductivity to demonstrate outstanding electrochemical performance. ACFs from KOH activation, in particular, showed very high 344 F g-1 specific capacitance at low 1.8 mg cm-2 mass loading and 10 mV s-1 scan rate in aqueous electrolytes. Even at relatively high scan rate of 50 mV s-1 and mass loading of 10 mg cm-2, a decent specific capacitance of 196 F g-1 and a remarkable areal capacitance of 0.55 F cm-2 was obtained, leading to high energy density of 8.1 Wh kg-1 based on averaged electrodes mass. Furthermore, over 96% capacitance retention rates were achieved after 5000 charge/discharge cycles. Such excellent performance demonstrated great potential of lignin derived carbons for electrical energy storage.

Development of the Juvenile Justice Anger Management Treatment for Girls

ERIC Educational Resources Information Center

Goldstein, Naomi E. S.; Serico, Jennifer M.; Riggs Romaine, Christina L.; Zelechoski, Amanda D.; Kalbeitzer, Rachel; Kemp, Kathleen; Lane, Christy

2013-01-01

Female juvenile offenders exhibit high levels of anger, relational aggression, and physical aggression, but the population has long been ignored in research and practice. No anger management treatments have been developed specifically for this population, and no established anger management treatments are empirically supported for use with…

Children's 5-HTTLPR genotype moderates the link between maternal criticism and attentional biases specifically for facial displays of anger.

PubMed

Gibb, Brandon E; Johnson, Ashley L; Benas, Jessica S; Uhrlass, Dorothy J; Knopik, Valerie S; McGeary, John E

2011-09-01

Theorists have proposed that negative experiences in childhood may contribute to the development of experience-specific information-processing biases, including attentional biases. There are also clear genetic influences on cognitive processes, with evidence that polymorphisms in specific candidate genes may moderate the impact of environmental stress on attentional biases (e.g., a functional polymorphism in the serotonin transporter gene; 5-HTTLPR). In the current study, we tested a gene×environment (G×E) model of risk for attentional biases. We hypothesised that children whose mothers exhibit high levels of expressed emotion criticism (EE-Crit) would display attentional biases specifically for angry, but not happy or sad, faces, and that this link would be stronger among children carrying one or two copies of the 5-HTTLPR short allele than among those homozygous for the long allele. Results generally supported these hypotheses, though we found that carriers of the 5-HTTLPR short allele who also had a critical mother exhibited attentional avoidance of angry faces rather than preferential attention.

Children’s 5-HTTLPR genotype moderates the link between maternal criticism and attentional biases specifically for facial displays of anger

PubMed Central

Gibb, Brandon E.; Johnson, Ashley L.; Benas, Jessica S.; Uhrlass, Dorothy J.; Knopik, Valerie S.; McGeary, John E.

2011-01-01

Theorists have proposed that negative experiences in childhood may contribute to the development of experience-specific information-processing biases, including attentional biases. There are also clear genetic influences on cognitive processes, with evidence that polymorphisms in specific candidate genes may moderate the impact of environmental stress on attentional biases (e.g., a functional polymorphism in the serotonin transporter gene [5-HTTLPR]). In the current study, we tested a gene × environment (G × E) model of risk for attentional biases. We hypothesized that children whose mothers exhibit high levels of expressed emotion criticism (EE-Crit) would display attentional biases specifically for angry, but not happy or sad, faces, and that this link would be stronger among children carrying one or two copies of the 5-HTTLPR short allele than among those homozygous for the long allele. Results generally supported these hypotheses, though we found that carriers of the 5-HTTLPR short allele who also had a critical mother exhibited attentional avoidance of angry faces rather than preferential attention. PMID:21895572

Redox-active triazatruxene-based conjugated microporous polymers for high-performance supercapacitors† †Electronic supplementary information (ESI) available: Synthetic procedures and characterization data for all new compounds; general experimental method; thermogravimetry curves; PXRD patterns; SEM and TEM images; XPS spectra. See DOI: 10.1039/c6sc05532j Click here for additional data file.

PubMed Central

Li, Xiang-Chun; Zhang, Yizhou; Wang, Chun-Yu; Wan, Yi

2017-01-01

Conjugated polymers (CPs) have been intensively explored for various optoelectronic applications in the last few decades. Nevertheless, CP based electrochemical energy storage devices such as supercapacitors remain largely unexplored. This is mainly owing to the low specific capacitance, poor structural/electrochemical stability, and low energy density of most existing CPs. In this contribution, a novel set of redox-active conjugated microporous polymers, TAT-CMP-1 and TAT-CMP-2, based on nitrogen-rich and highly conductive triazatruxene building blocks, were successfully designed and synthesized to explore their potential application as efficient and stable electrode materials for supercapacitors. Despite a moderate surface area of 88 m2 g–1 for TAT-CMP-1 and 106 m2 g–1 for TAT-CMP-2, exceptional specific capacitances of 141 F g–1 and 183 F g–1 were achieved at a current density of 1 A g–1. The resulting polymers exhibited unusually high areal specific capacitance (>160 μF cm–2), which is attributed to the pseudocapacitance resulting from redox-active structures with high nitrogen content. More importantly, the TAT-CMP-2 electrode exhibits excellent cycling stability: only 5% capacitance fading is observed after 10 000 cycles at a high current density of 10 A g–1, enabling the possible use of these materials as electrodes in electrochemical devices. PMID:28451362

Performance of Partially Exfoliated Nitrogen-Doped Carbon Nanotubes Wrapped with Hierarchical Porous Carbon in Electrolytes.

PubMed

Mangisetti, Sandhya Rani; Pari, Baraneedharan; M, Kamaraj; Ramaprabhu, Sundara

2018-05-25

The preparation of highly conductive, high-surface-area, heteroatom-doped, porous carbon nanocomposite materials with enhanced electrochemical performance for sustainable energy-storage technologies, such as supercapacitors, is challenging. Herein, a route for the large-scale synthesis of nitrogen-doped porous carbon wrapped partially exfoliated carbon nanotubes (N-PPECNTs) with an interconnected hierarchical porous structure, as an advanced electrode material that can realize several potential applications for energy storage, is presented. Polypyrrole conductive polymer acts as both nitrogen and carbon sources that contribute to the pseudocapacitance. Partially exfoliated carbon nanotubes (PECNTs) provide a high specific surface area for ion and charge transportation and act as a conductive matrix. The derived porous N-PPECNT displays a nitrogen content of 6.95 at %, with a specific surface area of 2050 m 2  g -1 , and pore volume of 1.13 cm 3  g -1 . N-PPECNTs, as an electrode material for supercapacitors, exhibit an excellent specific capacitance of 781 F g -1 at 2 A g -1 , with a high cycling stability of 95.3 % over 10 000 cycles. Furthermore, the symmetric supercapacitor exhibits remarkable energy densities as high as 172.8, 62.7, and 53.55 Wh kg -1 in 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([BMIM][TFSI]), organic, and aqueous electrolytes, respectively. Also, biocompatible hydrogel and polymer gel electrolyte based, stable, flexible supercapacitors with excellent electrochemical performance could be demonstrated. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Expression and Functional Properties of an Anti-Triazophos High-Affinity Single-Chain Variable Fragment Antibody with Specific Lambda Light Chain

PubMed Central

Liu, Rui; Liang, Xiao; Xiang, Dandan; Guo, Yirong; Liu, Yihua; Zhu, Guonian

2016-01-01

Triazophos is a widely used organophosphorous insecticide that has potentially adverse effects to organisms. In the present study, a high-affinity single-chain variable fragment (scFv) antibody with specific lambda light chain was developed for residue monitoring. First, the specific variable regions were correctly amplified from a hybridoma cell line 8C10 that secreted monoclonal antibody (mAb) against triazophos. The regions were then assembled as scFv via splicing by overlap extension polymerase chain reaction. Subsequently, the recombinant anti-triazophos scFv-8C10 was successfully expressed in Escherichia coli strain HB2151 in soluble form, purified through immobilized metal ion affinity chromatography, and verified via Western blot and peptide mass fingerprinting analyses. Afterward, an indirect competitive enzyme-linked immunosorbent assay was established based on the purified anti-triazophos scFv-8C10 antibody. The assay exhibited properties similar to those based on the parent mAb, with a high sensitivity (IC50 of 1.73 ng/mL) to triazophos and no cross reaction for other organophosphorus pesticides; it was reliable in detecting triazophos residues in spiked water samples. Moreover, kinetic measurement using a surface plasmon resonance biosensor indicated that the purified scFv-8C10 antibody had a high affinity of 1.8 × 10−10 M and exhibited good binding stability. Results indicated that the recombinant high-affinity scFv-8C10 antibody was an effective detection material that would be promising for monitoring triazophos residues in environment samples. PMID:27338340

Cobalt Oxide Porous Nanofibers Directly Grown on Conductive Substrate as a Binder/Additive-Free Lithium-Ion Battery Anode with High Capacity.

PubMed

Liu, Hao; Zheng, Zheng; Chen, Bochao; Liao, Libing; Wang, Xina

2017-12-01

In order to reduce the amount of inactive materials, such as binders and carbon additives in battery electrode, porous cobalt monoxide nanofibers were directly grown on conductive substrate as a binder/additive-free lithium-ion battery anode. This electrode exhibited very high specific discharging/charging capacities at various rates and good cycling stability. It was promising as high capacity anode materials for lithium-ion battery.

Improving sensitivity and specificity of capturing and detecting targeted cancer cells with anti-biofouling polymer coated magnetic iron oxide nanoparticles.

PubMed

Lin, Run; Li, Yuancheng; MacDonald, Tobey; Wu, Hui; Provenzale, James; Peng, Xingui; Huang, Jing; Wang, Liya; Wang, Andrew Y; Yang, Jianyong; Mao, Hui

2017-02-01

Detecting circulating tumor cells (CTCs) with high sensitivity and specificity is critical to management of metastatic cancers. Although immuno-magnetic technology for in vitro detection of CTCs has shown promising potential for clinical applications, the biofouling effect, i.e., non-specific adhesion of biomolecules and non-cancerous cells in complex biological samples to the surface of a device/probe, can reduce the sensitivity and specificity of cell detection. Reported herein is the application of anti-biofouling polyethylene glycol-block-allyl glycidyl ether copolymer (PEG-b-AGE) coated iron oxide nanoparticles (IONPs) to improve the separation of targeted tumor cells from aqueous phase in an external magnetic field. PEG-b-AGE coated IONPs conjugated with transferrin (Tf) exhibited significant anti-biofouling properties against non-specific protein adsorption and off-target cell uptake, thus substantially enhancing the ability to target and separate transferrin receptor (TfR) over-expressed D556 medulloblastoma cells. Tf conjugated PEG-b-AGE coated IONPs exhibited a high capture rate of targeted tumor cells (D556 medulloblastoma cell) in cell media (58.7±6.4%) when separating 100 targeted tumor cells from 1×10 5 non-targeted cells and 41 targeted tumor cells from 100 D556 medulloblastoma cells spiked into 1mL blood. It is demonstrated that developed nanoparticle has higher efficiency in capturing targeted cells than widely used micron-sized particles (i.e., Dynabeads ® ). Copyright © 2016 Elsevier B.V. All rights reserved.

Th1-like Plasmodium-Specific Memory CD4+ T Cells Support Humoral Immunity.

PubMed

Zander, Ryan A; Vijay, Rahul; Pack, Angela D; Guthmiller, Jenna J; Graham, Amy C; Lindner, Scott E; Vaughan, Ashley M; Kappe, Stefan H I; Butler, Noah S

2017-11-14

Effector T cells exhibiting features of either T helper 1 (Th1) or T follicular helper (Tfh) populations are essential to control experimental Plasmodium infection and are believed to be critical for resistance to clinical malaria. To determine whether Plasmodium-specific Th1- and Tfh-like effector cells generate memory populations that contribute to protection, we developed transgenic parasites that enable high-resolution study of anti-malarial memory CD4 T cells in experimental models. We found that populations of both Th1- and Tfh-like Plasmodium-specific memory CD4 T cells persist. Unexpectedly, Th1-like memory cells exhibit phenotypic and functional features of Tfh cells during recall and provide potent B cell help and protection following transfer, characteristics that are enhanced following ligation of the T cell co-stimulatory receptor OX40. Our findings delineate critical functional attributes of Plasmodium-specific memory CD4 T cells and identify a host-specific factor that can be targeted to improve resolution of acute malaria and provide durable, long-term protection against Plasmodium parasite re-exposure. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Rapidly Synthesized, Few-Layered Pseudocapacitive SnS2 Anode for High-Power Sodium Ion Batteries.

PubMed

Thangavel, Ranjith; Samuthira Pandian, Amaresh; Ramasamy, Hari Vignesh; Lee, Yun-Sung

2017-11-22

The abundance of sodium resources has recently motivated the investigation of sodium ion batteries (SIBs) as an alternative to commercial lithium ion batteries. However, the low power and low capacity of conventional sodium anodes hinder their practical realization. Although most research has concentrated on the development of high-capacity sodium anodes, anodes with a combination of high power and high capacity have not been widely realized. Herein, we present a simple microwave irradiation technique for obtaining few-layered, ultrathin two-dimensional SnS 2 over graphene sheets in a few minutes. SnS 2 possesses a large number of active surface sites and exhibits high-capacity, rapid sodium ion storage kinetics induced by quick, nondestructive pseudocapacitance. Enhanced sodium ion storage at a high current density (12 A g -1 ), accompanied by high reversibility and high stability, was demonstrated. Additionally, a rationally designed sodium ion full cell coupled with SnS 2 //Na 3 V 2 (PO 4 ) 3 exhibited exceptional performance with high initial Coulombic efficiency (99%), high capacity, high stability, and a retention of ∼53% of the initial capacity even after the current density was increased by a factor of 140. In addition, a high specific energy of ∼140 Wh kg -1 and an ultrahigh specific power of ∼8.3 kW kg -1 (based on the mass of both the anode and cathode) were observed. Because of its outstanding performance and rapid synthesis, few-layered SnS 2 could be a promising candidate for practical realization of high-power SIBs.

Tissue-specific regulation of BMP signaling by Drosophila N-glycanase 1.

PubMed

Galeone, Antonio; Han, Seung Yeop; Huang, Chengcheng; Hosomi, Akira; Suzuki, Tadashi; Jafar-Nejad, Hamed

2017-08-04

Mutations in the human N- glycanase 1 ( NGLY1 ) cause a rare, multisystem congenital disorder with global developmental delay. However, the mechanisms by which NGLY1 and its homologs regulate embryonic development are not known. Here we show that Drosophila Pngl encodes an N -glycanase and exhibits a high degree of functional conservation with human NGLY1. Loss of Pngl results in developmental midgut defects reminiscent of midgut-specific loss of BMP signaling. Pngl mutant larvae also exhibit a severe midgut clearance defect, which cannot be fully explained by impaired BMP signaling. Genetic experiments indicate that Pngl is primarily required in the mesoderm during Drosophila development. Loss of Pngl results in a severe decrease in the level of Dpp homodimers and abolishes BMP autoregulation in the visceral mesoderm mediated by Dpp and Tkv homodimers. Thus, our studies uncover a novel mechanism for the tissue-specific regulation of an evolutionarily conserved signaling pathway by an N -glycanase enzyme.

High Performance All-solid Supercapacitors Based on the Network of Ultralong Manganese dioxide/Polyaniline Coaxial Nanowires

NASA Astrophysics Data System (ADS)

Zhou, Junli; Yu, Lin; Liu, Wei; Zhang, Xiaodan; Mu, Wei; Du, Xu; Zhang, Zhe; Deng, Yulin

2015-12-01

In recent years, thin, lightweight and flexible solid supercapacitors are of considerable interest as energy storage devices. Here we demonstrated all-solid supercapacitors (SSCs) with high electrochemical properties, low self-discharge characteristics based on manganese dioxide/polyaniline (MNW/PANI) coaxial nanowire networks. The synergistic effect of MnO2/PANI plus the unique coaxial nanostructure of the ultralong nanowires with a highly interconnected network effectively enhance the conductivity and capacitive performance of the SSCs device. The MNW/PANI composite with 62.5% MnO2 exhibits an outstanding areal specific capacitance reaching 346 mF/cm2 at 5 mV s-1 which is significant higher than most previously reported solid supercapacitors (15.3 mF/cm2-109 mF/cm2) and is close to the that of the best graphene films solid state supercapacitors (372 mF/cm2). In contrast, only 190 mF/cm2 of areal specific capacitance was obtained for the pure MnO2 NW network. The supercapacitors also exhibited low leakage current as small as 20.1 μA, which demonstrated that the MNW/PANI SSCs have great potential for practical applications.

Utilizing Waste Thermocol Sheets and Rusted Iron Wires to Fabricate Carbon-Fe3O4 Nanocomposite Based Supercapacitors: Turning Wastes into Value-Added Materials.

PubMed

Vadiyar, Madagonda M; Liu, Xudong; Ye, Zhibin

2018-05-14

In the present work, we demonstrate the synthesis of porous activated carbon (specific surface area, 1,883 m2 g-1), Fe3O4 nanoparticles, and carbon-Fe3O4 nanocomposites using local waste thermocol sheets and rusted iron wires. The resulting carbon, Fe3O4 nanoparticles, and carbon-Fe3O4 composites are used as electrode materials for supercapacitor application. In particular, C-Fe3O4 composite electrodes exhibit a high specific capacitance of 1,375 F g-1 at 1 A g-1 and longer cyclic stability with 98 % of capacitance retention over 10,000 cycles. Subsequently, asymmetric supercapacitor, i. e., C-Fe3O4//Ni(OH)2/CNT device exhibits a high energy density of 91.1 Wh kg-1 and a remarkable cyclic stability, showing 98% of capacitance retention over 10,000 cycles. Thus, this work has important implications not only for the fabrication of low-cost electrodes for high-performance supercapacitors but also for the recycling of waste thermocol sheets and rust iron wires for value-added reuse. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High Performance All-solid Supercapacitors Based on the Network of Ultralong Manganese dioxide/Polyaniline Coaxial Nanowires.

PubMed

Zhou, Junli; Yu, Lin; Liu, Wei; Zhang, Xiaodan; Mu, Wei; Du, Xu; Zhang, Zhe; Deng, Yulin

2015-12-08

In recent years, thin, lightweight and flexible solid supercapacitors are of considerable interest as energy storage devices. Here we demonstrated all-solid supercapacitors (SSCs) with high electrochemical properties, low self-discharge characteristics based on manganese dioxide/polyaniline (MNW/PANI) coaxial nanowire networks. The synergistic effect of MnO2/PANI plus the unique coaxial nanostructure of the ultralong nanowires with a highly interconnected network effectively enhance the conductivity and capacitive performance of the SSCs device. The MNW/PANI composite with 62.5% MnO2 exhibits an outstanding areal specific capacitance reaching 346 mF/cm(2) at 5 mV s(-1) which is significant higher than most previously reported solid supercapacitors (15.3 mF/cm(2)-109 mF/cm(2)) and is close to the that of the best graphene films solid state supercapacitors (372 mF/cm(2)). In contrast, only 190 mF/cm(2) of areal specific capacitance was obtained for the pure MnO2 NW network. The supercapacitors also exhibited low leakage current as small as 20.1 μA, which demonstrated that the MNW/PANI SSCs have great potential for practical applications.

Hierarchical porous NiCo2O4 nanowires for high-rate supercapacitors.

PubMed

Jiang, Hao; Ma, Jan; Li, Chunzhong

2012-05-11

We demonstrate a simple and scalable strategy for synthesizing hierarchical porous NiCo(2)O(4) nanowires which exhibit a high specific capacitance of 743 F g(-1) at 1 A g(-1) with excellent rate performance (78.6% capacity retention at 40 A g(-1)) and cycling stability (only 6.2% loss after 3000 cycles). This journal is © The Royal Society of Chemistry 2012

Weak localization of electromagnetic waves and opposition phenomena exhibited by high-albedo atmosphereless solar system objects.

PubMed

Mishchenko, Michael I; Rosenbush, Vera K; Kiselev, Nikolai N

2006-06-20

The totality of new and previous optical observations of a class of high-albedo solar system objects at small phase angles reveals a unique combination of extremely narrow brightness and polarization features centered at exactly the opposition. The specific morphological parameters of these features provide an almost unequivocal evidence that they are caused by the renowned effect of coherent backscattering.

Dual-carbon enhanced silicon-based composite as superior anode material for lithium ion batteries

NASA Astrophysics Data System (ADS)

Wang, Jie; Liu, Dai-Huo; Wang, Ying-Ying; Hou, Bao-Hua; Zhang, Jing-Ping; Wang, Rong-Shun; Wu, Xing-Long

2016-03-01

Dual-carbon enhanced Si-based composite (Si/C/G) has been prepared via employing the widely distributed, low-cost and environmentally friendly Diatomite mineral as silicon raw material. The preparation processes are very simple, non-toxic and easy to scale up. Electrochemical tests as anode material for lithium ion batteries (LIBs) demonstrate that this Si/C/G composite exhibits much improved Li-storage properties in terms of superior high-rate capabilities and excellent cycle stability compared to the pristine Si material as well as both single-carbon modified composites. Specifically for the Si/C/G composite, it can still deliver a high specific capacity of about 470 mAh g-1 at an ultrahigh current density of 5 A g-1, and exhibit a high capacity of 938 mAh g-1 at 0.1 A g-1 with excellent capacity retention in the following 300 cycles. The significantly enhanced Li-storage properties should be attributed to the co-existence of both highly conductive graphite and amorphous carbon in the Si/C/G composite. While the former can enhance the electrical conductivity of the obtained composite, the latter acts as the adhesives to connect the porous Si particulates and conductive graphite flakes to form robust and stable conductive network.

Preparation of morphology-controllable polyaniline and polyaniline/graphene hydrogels for high performance binder-free supercapacitor electrodes

NASA Astrophysics Data System (ADS)

Luo, Jinwei; Zhong, Wenbin; Zou, Yubo; Xiong, Changlun; Yang, Wantai

2016-07-01

Polyaniline (PANI) and its composite hydrogels have been considered as a unique supercapacitor electrode material due to their three dimensional (3D) porous structures, formed conducting networks, high specific surface areas and fast electron/ion transfer. Herein, dendritic and long fibrous PANI nanostructure hydrogels (PDH and PFH), dendritic PNAI nanofiber/graphene and long PANI nanofibers/Nitrogen-doped graphene composite hydrogels (PGH and PNGH) were prepared by integration polymerization of aniline and hydrothermal process. It was found that the addition of p-Phenylenediamine (PPD) not only controlled the morphologies of PANI from dendritic to long fibrous, but also facilitated the graphene oxide (GO) into nitrogen-doped graphene. Furthermore, after freeze-drying, PDH and PGH exhibited a max compressive strength of 9.5 and 9.6 KPa, respectively; while the max compressive strength of PFH and PNGH constructed with long PANI nanofiber is 79.9 and 75.8 KPa, respectively. Directly using these prepared hydrogels as electrodes for supercapacitors, it was found that PDH, PFH, PGH and PNGH exhibited high specific capacitances of 448.6, 470, 540.9 and 610 F g-1, respectively, at the current density of 1 A g-1. It is expected that the prepared PDH, PFH, PGH and PNGH can be directly applied in the field of high performance energy storage devices.

A facile one-pot self-assembly approach to incorporate SnOx nanoparticles in ordered mesoporous carbon with soft templating for fuel cells.

PubMed

Huang, Yingqiang; Zhai, Zhicheng; Luo, Zhigang; Liu, Yingju; Liang, Zhurong; Fang, Yueping

2014-04-04

Unique SnO(x) (x = 1,2)/ordered mesoporous carbon nanocomposites (denoted as SnO(x)/OMC) are firstly synthesized through a 'one-pot' synthesis together with the soft template self-assembly approach. The obtained SnO(x)/OMC nanocomposites with various SnO(x) contents exhibit uniform pore sizes between 3.9 and 4.2 nm, high specific surface areas between 497 and 595 m(2) g(-1), and high pore volumes between 0.39 and 0.48 cm(3) g(-1). With loading of Pt, Pt-SnO(x)/OMC with relatively low SnO(x) content exhibits superior electrocatalytic performance, long-term durability, and resistance to CO poisoning for methanol oxidation, as compared to Pt/OMC, PtRu/C and Pt-SnO(x)/C, which may be attributed not only to the synergetic effect of embedded SnO(x), but also to the highly ordered mesostructure with high specific surface areas and large pore volumes affording plenty of surface area for support of Pt nanoparticles. This work supplies an efficient way to synthesize novel ordered mesoporous carbon self-supported metallic oxide as catalyst support and its further potential application to reduce the cost of catalysts in direct methanol fuel cells.

A facile one-pot self-assembly approach to incorporate SnOx nanoparticles in ordered mesoporous carbon with soft templating for fuel cells

NASA Astrophysics Data System (ADS)

Huang, Yingqiang; Zhai, Zhicheng; Luo, Zhigang; Liu, Yingju; Liang, Zhurong; Fang, Yueping

2014-04-01

Unique SnOx (x = 1,2)/ordered mesoporous carbon nanocomposites (denoted as SnOx/OMC) are firstly synthesized through a ‘one-pot’ synthesis together with the soft template self-assembly approach. The obtained SnOx/OMC nanocomposites with various SnOx contents exhibit uniform pore sizes between 3.9 and 4.2 nm, high specific surface areas between 497 and 595 m2 g-1, and high pore volumes between 0.39 and 0.48 cm3 g-1. With loading of Pt, Pt-SnOx/OMC with relatively low SnOx content exhibits superior electrocatalytic performance, long-term durability, and resistance to CO poisoning for methanol oxidation, as compared to Pt/OMC, PtRu/C and Pt-SnOx/C, which may be attributed not only to the synergetic effect of embedded SnOx, but also to the highly ordered mesostructure with high specific surface areas and large pore volumes affording plenty of surface area for support of Pt nanoparticles. This work supplies an efficient way to synthesize novel ordered mesoporous carbon self-supported metallic oxide as catalyst support and its further potential application to reduce the cost of catalysts in direct methanol fuel cells.

Transgenic Citrus Expressing an Arabidopsis NPR1 Gene Exhibit Enhanced Resistance against Huanglongbing (HLB; Citrus Greening).

PubMed

Dutt, Manjul; Barthe, Gary; Irey, Michael; Grosser, Jude

2015-01-01

Commercial sweet orange cultivars lack resistance to Huanglongbing (HLB), a serious phloem limited bacterial disease that is usually fatal. In order to develop sustained disease resistance to HLB, transgenic sweet orange cultivars 'Hamlin' and 'Valencia' expressing an Arabidopsis thaliana NPR1 gene under the control of a constitutive CaMV 35S promoter or a phloem specific Arabidopsis SUC2 (AtSUC2) promoter were produced. Overexpression of AtNPR1 resulted in trees with normal phenotypes that exhibited enhanced resistance to HLB. Phloem specific expression of NPR1 was equally effective for enhancing disease resistance. Transgenic trees exhibited reduced diseased severity and a few lines remained disease-free even after 36 months of planting in a high-disease pressure field site. Expression of the NPR1 gene induced expression of several native genes involved in the plant defense signaling pathways. The AtNPR1 gene being plant derived can serve as a component for the development of an all plant T-DNA derived consumer friendly GM tree.

Hydrothermal synthesis of novel Mn(3)O(4) nano-octahedrons with enhanced supercapacitors performances.

PubMed

Jiang, Hao; Zhao, Ting; Yan, Chaoyi; Ma, Jan; Li, Chunzhong

2010-10-01

Uniform and single-crystalline Mn(3)O(4) nano-octahedrons have been successfully synthesized by a simple ethylenediaminetetraacetic acid disodium salt (EDTA-2Na) assisted hydrothermal route. The octahedron structures exhibit a high geometric symmetry with smooth surfaces and the mean side length of square base of octahedrons is ∼160 nm. The structure is reckoned to provide superior functional properties and the nano-size achieved in the present work is noted to further facilitate the material property enhancement. The formation process was proposed to begin with a "dissolution-recrystallization" which is followed by an "Ostwald ripening" mechanism. The Mn(3)O(4) nano-octahedrons exhibited an enhanced specific capacitance of 322 F g(-1) compared with the truncated octahedrons with specific capacitances of 244 F g(-1), making them a promising electrode material for supercapacitors.

Enhancement of Lutein Production in Chlorella sorokiniana (Chorophyta) by Improvement of Culture Conditions and Random Mutagenesis

PubMed Central

Cordero, Baldo F.; Obraztsova, Irina; Couso, Inmaculada; Leon, Rosa; Vargas, Maria Angeles; Rodriguez, Herminia

2011-01-01

Chlorella sorokiniana has been selected for lutein production, after a screening of thirteen species of microalgae, since it showed both a high content in this carotenoid and a high growth rate. The effects of several nutritional and environmental factors on cell growth and lutein accumulation have been studied. Maximal specific growth rate and lutein content were attained at 690 μmol photons m−2 s−1, 28 °C, 2 mM NaCl, 40 mM nitrate and under mixotrophic conditions. In general, optimal conditions for the growth of this strain also lead to maximal lutein productivity. High lutein yielding mutants of C. sorokiniana have been obtained by random mutagenesis, using N-methyl-N′-nitro-nitrosoguanidine (MNNG) as a mutagen and selecting mutants by their resistance to the inhibitors of the carotenogenic pathway nicotine and norflurazon. Among the mutants resistant to the herbicides, those exhibiting both high content in lutein and high growth rate were chosen. Several mutants exhibited higher contents in this carotenoid than the wild type, showing, in addition, either a similar or higher growth rate than the latter strain. The mutant MR-16 exhibited a 2.0-fold higher volumetric lutein content than that of the wild type, attaining values of 42.0 mg L−1 and mutants DMR-5 and DMR-8 attained a lutein cellular content of 7.0 mg g−1 dry weight. The high lutein yield exhibited by C. sorokiniana makes this microalga an excellent candidate for the production of this commercially interesting pigment. PMID:22131961

Characterization of Antibodies for Grain-Specific Gluten Detection.

PubMed

Sharma, Girdhari M; Rallabhandi, Prasad; Williams, Kristina M; Pahlavan, Autusa

2016-03-01

Gluten ingestion causes immunoglobulin E (IgE)-mediated allergy or celiac disease in sensitive individuals, and a strict gluten-free diet greatly limits food choices. Immunoassays such as enzyme-linked immunosorbent assay (ELISA) are used to quantify gluten to ensure labeling compliance of gluten-free foods. Anti-gluten antibodies may not exhibit equal affinity to gluten from wheat, rye, and barley. Moreover, because wheat gluten is commonly used as a calibrator in ELISA, accurate gluten quantitation from rye and barley contaminated foods may be compromised. Immunoassays utilizing grain-specific antibodies and calibrators may help improve gluten quantitation. In this study, polyclonal antibodies raised against gluten-containing grain-specific peptides were characterized for their immunoreactivity to gluten from different grain sources. Strong immunoreactivity to multiple gluten polypeptides from wheat, rye, and barley was observed in the range 34 to 43 kDa with anti-gliadin, 11 to 15 and 72 to 95 kDa with anti-secalin, and 30 to 43 kDa with anti-hordein peptide antibodies, respectively. Minimal or no cross-reactivity with gluten from other grains was observed among these antibodies. The anti-consensus peptide antibody raised against a repetitive amino acid sequence of proline and glutamine exhibited immunoreactivity to gluten from wheat, rye, barley, and oat. The antibodies exhibited similar immunoreactivity with most of the corresponding grain cultivars by ELISA. The high specificity and minimal cross-reactivity of grain-specific antibodies suggest their potential use in immunoassays for accurate gluten quantitation. © Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Ru-assisted synthesis of Pd/Ru nanodendrites with high activity for ethanol electrooxidation

NASA Astrophysics Data System (ADS)

Zhang, Ke; Bin, Duan; Yang, Beibei; Wang, Caiqin; Ren, Fangfang; Du, Yukou

2015-07-01

Due to the specific physical and chemical properties of a highly branched noble metal, the controllable synthesis has attracted much attention. This article reports the synthesis of Pd/Ru nanodendrites by a facile method using an oil bath in the presence of polyvinyl pyrrolidone, potassium bromide and ascorbic acid. The morphology, structure, and composition of the as-prepared catalysts were characterized by means of X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. In the electrochemical measurement, the as-prepared Pd7/Ru1 bimetallic nanodendrites provide a large electrochemically active surface area and exhibit high peak current density in the forward scan toward ethanol electrooxidation, which is nearly four times higher than those of a pure Pd catalyst. The as-prepared Pd7/Ru1 catalysts also exhibit significantly enhanced cycling stability toward ethanol oxidation in alkaline medium, which are mainly ascribed to the synergetic effect between Pd and Ru. This indicates that the Pd7/Ru1 catalysts should have great potential applications in direct ethanol fuel cells.Due to the specific physical and chemical properties of a highly branched noble metal, the controllable synthesis has attracted much attention. This article reports the synthesis of Pd/Ru nanodendrites by a facile method using an oil bath in the presence of polyvinyl pyrrolidone, potassium bromide and ascorbic acid. The morphology, structure, and composition of the as-prepared catalysts were characterized by means of X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. In the electrochemical measurement, the as-prepared Pd7/Ru1 bimetallic nanodendrites provide a large electrochemically active surface area and exhibit high peak current density in the forward scan toward ethanol electrooxidation, which is nearly four times higher than those of a pure Pd catalyst. The as-prepared Pd7/Ru1 catalysts also exhibit significantly enhanced cycling stability toward ethanol oxidation in alkaline medium, which are mainly ascribed to the synergetic effect between Pd and Ru. This indicates that the Pd7/Ru1 catalysts should have great potential applications in direct ethanol fuel cells. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr02713f

Controllably annealed CuO-nanoparticle modified ITO electrodes: Characterisation and electrochemical studies

NASA Astrophysics Data System (ADS)

Wang, Tong; Su, Wen; Fu, Yingyi; Hu, Jingbo

2016-12-01

In this paper, we report a facile and controllable two-step approach to produce indium tin oxide electrodes modified by copper(II) oxide nanoparticles (CuO/ITO) through ion implantation and annealing methods. After annealing treatment, the surface morphology of the CuO/ITO substrate changed remarkably and exhibited highly electroactive sites and a high specific surface area. The effects of annealing treatment on the synthesis of CuO/ITO were discussed based on various instruments' characterisations, and the possible mechanism by which CuO nanoparticles were generated was also proposed in this work. Cyclic voltammetric results indicated that CuO/ITO electrodes exhibited effective catalytic responses toward glucose in alkaline solution. Under optimal experimental conditions, the proposed CuO/ITO electrode showed sensitivity of 450.2 μA cm-2 mM-1 with a linear range of up to ∼4.4 mM and a detection limit of 0.7 μM (S/N = 3). Moreover, CuO/ITO exhibited good poison resistance, reproducibility, and stability properties.

Biochemical characterization of a thermophilic β-mannanase from Talaromyces leycettanus JCM12802 with high specific activity.

PubMed

Wang, Caihong; Luo, Huiying; Niu, Canfang; Shi, Pengjun; Huang, Huoqing; Meng, Kun; Bai, Yingguo; Wang, Kun; Hua, Huifang; Yao, Bin

2015-02-01

Thermophilic β-mannanases are of increasing importance for wide industrial applications. In the current study, gene cloning, functional expression in Pichia pastoris, and characterization of a thermophilic β-mannanase (Man5A) from thermophilic Talaromyces leycettanus JCM12802 are reported. Deduced Man5A exhibits the highest identity with a putative β-mannanase from Talaromyces stipitatus ATCC10500 (70.3 %) and is composed of an N-terminal signal peptide, a fungal-type carbohydrate-binding module (CBM) of family 1, and a catalytic domain of glycosyl hydrolase (GH) family 5 at the C-terminus. Two recombinant proteins with different glycosylation levels, termed Man5A1 (72 kDa) and Man5A2 (60 kDa), were identified after purification. Both enzymes were thermophilic, exhibiting optimal activity at 85-90 °C, and were highly stable at 70 °C. Man5A1 and Man5A2 had a pH optimum of 4.5 and 4.0, respectively, and were highly stable over the broad pH range of 3.0-10.0. Most metal ions and sodium dodecyl sulfate (SDS) had no effect on the enzymatic activities. Man5A1 and Man5A2 exhibited high specific activity (2,160 and 1,800 U/mg, respectively) when using locust bean gum as the substrate. The CBM1 and two key residues D191 and R286 were found to affect Man5A thermostability. Man5A displays a classical four-site-binding mode, hydrolyzing mannooligosaccharides into smaller units, galactomannan into mannose and mannobiose, and glucomanman into mannose, mannobiose, and mannopentaose, respectively. All these properties make Man5A a good candidate for extensive applications in the bioconversion, pulp bleaching, textile, food, and feed industries.

A Sustainable Route from Biomass Byproduct Okara to High Content Nitrogen-Doped Carbon Sheets for Efficient Sodium Ion Batteries.

PubMed

Yang, Tingzhou; Qian, Tao; Wang, Mengfan; Shen, Xiaowei; Xu, Na; Sun, Zhouzhou; Yan, Chenglin

2016-01-20

A sustainable route from the biomass byproduct okara as a natural nitrogen fertilizer to high-content N-doped carbon sheets is demonstrated. The as-prepared unique structure exhibits high specific capacity (292 mAh g(-1) ) and extremely long cycle life (exceeding 2000 cycles). A full battery is devised for the practical use of materials with a flexible/wearable LED screen. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Dual-Specific Targeting Approach Based on the Simultaneous Recognition of Duplex and Quadruplex Motifs.

PubMed

Nguyen, Thi Quynh Ngoc; Lim, Kah Wai; Phan, Anh Tuân

2017-09-20

Small-molecule ligands targeting nucleic acids have been explored as potential therapeutic agents. Duplex groove-binding ligands have been shown to recognize DNA in a sequence-specific manner. On the other hand, quadruplex-binding ligands exhibit high selectivity between quadruplex and duplex, but show limited discrimination between different quadruplex structures. Here we propose a dual-specific approach through the simultaneous application of duplex- and quadruplex-binders. We demonstrated that a quadruplex-specific ligand and a duplex-specific ligand can simultaneously interact at two separate binding sites of a quadruplex-duplex hybrid harbouring both quadruplex and duplex structural elements. Such a dual-specific targeting strategy would combine the sequence specificity of duplex-binders and the strong binding affinity of quadruplex-binders, potentially allowing the specific targeting of unique quadruplex structures. Future research can be directed towards the development of conjugated compounds targeting specific genomic quadruplex-duplex sites, for which the linker would be highly context-dependent in terms of length and flexibility, as well as the attachment points onto both ligands.

Galvanic displacement assembly of ultrathin Co3O4 nanosheet arrays on nickel foam for a high-performance supercapacitor

NASA Astrophysics Data System (ADS)

You, Yuxiu; Zheng, Maojun; Ma, Liguo; Yuan, Xiaoliang; Zhang, Bin; Li, Qiang; Wang, Faze; Song, Jingnan; Jiang, Dongkai; Liu, Pengjie; Ma, Li; Shen, Wenzhong

2017-03-01

High-performance supercapacitors are very desirable for many portable electronic devices, electric vehicles and high-power electronic devices. Herein, a facile and binder-free synthesis method, galvanic displacement of the precursor followed by heat treatment, is used to fabricate ultrathin Co3O4 nanosheet arrays on nickel foam substrate. When used as a supercapacitor electrode the prepared Co3O4 on nickel foam exhibits a maximum specific capacitance of 1095 F g-1 at a current density of 1 A g-1 and good cycling stability of 71% retention after 2000 cycling tests. This excellent electrochemical performance can be ascribed to the high specific surface area of each Co3O4 nanosheet that comprises numerous nanoparticles.

Study on the electrochemical properties of cubic ordered mesoporous carbon for supercapacitors

NASA Astrophysics Data System (ADS)

Lang, Jun-Wei; Yan, Xing-Bin; Yuan, Xiao-Yan; Yang, Jie; Xue, Qun-Ji

Highly ordered, three-dimensional (3D) cubic mesoporous carbon CMK-8 is prepared by a facile nanocasting approach using cubic mesoporous silica KIT-6 as starting template. Afterwards, in order to increase the active sites of surface electrochemical reactions and promote the wettability in aqueous electrolyte, a chemical surface modification is carried out on the CMK-8 by nitric acid treatment. Two electrodes are prepared from the CMK-8 and the acid-modified CMK-8 (H-CMK-8) and used as the active materials for supercapacitors. The unique 3D mesoporous network combined with high specific surface area makes the nano-channel surfaces of the CMK-8 carbon favorable for charging the electric double-layer, resulting in that the CMK-8 and the H-CMK-8 electrodes both show well supercapacitive properties. Furthermore, the specific capacitance of the CMK-8 can be further improved by acid treatment, so that the H-CMK-8 exhibits the largest specific capacitance of 246 F g -1 at a current density of 0.625 A g -1 in 2 M KOH electrolyte. Also, the two carbon electrodes both exhibit good cycling stability and lifetime. Therefore, based on the above investigations, such CMK-8 carbon, especially H-CMK-8 carbon can be a potential candidate for supercapacitors.

To Be or Not to Be Symmetric: That is the Question for Potentially Active Vibronic Modes

ERIC Educational Resources Information Center

Tyler, Sarah F.; Judkins, Eileen C.; Morozov, Dmitry; Borca, Carlos H.; Slipchenko, Lyudmila V.; McMillin, David R.

2017-01-01

Electronic spectra often exhibit vibronic structure when vibrational and electronic transitions occur in concert. Theory reveals (1) that orbital symmetry considerations determine specific roles played by the nuclear degrees of freedom and (2) that the vibrational excitation is often highly regiospecific, that is, attributable to an identifiable…

Functionalized graphene hydrogel-based high-performance supercapacitors.

PubMed

Xu, Yuxi; Lin, Zhaoyang; Huang, Xiaoqing; Wang, Yang; Huang, Yu; Duan, Xiangfeng

2013-10-25

Functionalized graphene hydrogels are prepared by a one-step low-temperature reduction process and exhibit ultrahigh specific capacitances and excellent cycling stability in the aqueous electrolyte. Flexible solid-state supercapacitors based on functionalized graphene hydrogels are demonstrated with superior capacitive performances and extraordinary mechanical flexibility. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Early College Entrance: How Will My Child Do?

ERIC Educational Resources Information Center

Chung, Rachel U.; Hertzog, Nancy B.

2014-01-01

Early college entrance is a form of acceleration, or the process of advancing students in academic programs faster than their same-aged peers. Many early entrants have demonstrated academic ability to achieve at high levels but they exhibit tremendous variety in their age, specific abilities, social and emotional maturity, family support, and…

Incorporation of heterostructured Sn/SnO nanoparticles in crumpled nitrogen-doped graphene nanosheets for application as anodes in lithium-ion batteries.

PubMed

Du, Fei-Hu; Liu, Yu-Si; Long, Jie; Zhu, Qian-Cheng; Wang, Kai-Xue; Wei, Xiao; Chen, Jie-Sheng

2014-09-07

Sn/SnO nanoparticles are incorporated in crumpled nitrogen-doped graphene nanosheets by a simple melting diffusion method. The resulting composite exhibits large specific capacity, excellent cycling stability and high rate capability as an anode for lithium-ion batteries.

Use of Analog Functional Analysis in Assessing the Function of Mealtime Behavior Problems.

ERIC Educational Resources Information Center

Girolami, Peter A.; Scotti, Joseph R.

2001-01-01

This study applied the methodology of an analog experimental (functional) analysis of behavior to the specific interaction between parents and three children with mental retardation exhibiting food refusal and related mealtime problems. Analog results were highly consistent with other forms of functional assessment data, including interviews,…

Controlled insertional mutagenesis using a LINE-1 (ORFeus) gene-trap mouse model.

PubMed

O'Donnell, Kathryn A; An, Wenfeng; Schrum, Christina T; Wheelan, Sarah J; Boeke, Jef D

2013-07-16

A codon-optimized mouse LINE-1 element, ORFeus, exhibits dramatically higher retrotransposition frequencies compared with its native long interspersed element 1 counterpart. To establish a retrotransposon-mediated mouse model with regulatable and potent mutagenic capabilities, we generated a tetracycline (tet)-regulated ORFeus element harboring a gene-trap cassette. Here, we show that mice expressing tet-ORFeus broadly exhibit robust retrotransposition in somatic tissues when treated with doxycycline. Consistent with a significant mutagenic burden, we observed a reduced number of double transgenic animals when treated with high-level doxycycline during embryogenesis. Transgene induction in skin resulted in a white spotting phenotype due to somatic ORFeus-mediated mutations that likely disrupt melanocyte development. The data suggest a high level of transposition in melanocyte precursors and consequent mutation of genes important for melanoblast proliferation, differentiation, or migration. These findings reveal the utility of a retrotransposon-based mutagenesis system as an alternative to existing DNA transposon systems. Moreover, breeding these mice to different tet-transactivator/reversible tet-transactivator lines supports broad functionality of tet-ORFeus because of the potential for dose-dependent, tissue-specific, and temporal-specific mutagenesis.

Flower-like Copper Cobaltite Nanosheets on Graphite Paper as High-Performance Supercapacitor Electrodes and Enzymeless Glucose Sensors.

PubMed

Liu, Shude; Hui, K S; Hui, K N

2016-02-10

Flower-like copper cobaltite (CuCo2O4) nanosheets anchored on graphite paper have been synthesized using a facile hydrothermal method followed by a postannealing treatment. Supercapacitor electrodes employing CuCo2O4 nanosheets exhibit an enhanced capacitance of 1131 F g(-1) at a current density of 1 A g(-1) compared with previously reported supercapacitor electrodes. The CuCo2O4 electrode delivers a specific capacitance of up to 409 F g(-1) at a current density of as high as 50 A g(-1), and a good long-term cycling stability, with 79.7% of its specific capacitance retained after 5000 cycles at 10 A g(-1). Furthermore, the as-prepared CuCo2O4 nanosheets on graphite paper can be fabricated as electrodes and used as enzymeless glucose sensors, which exhibit good sensitivity (3.625 μA μM(-1) cm(-2)) and an extraordinary linear response ranging up to 320 μM with a low detection limit (5 μM).

Facile Synthesis of Novel Networked Ultralong Cobalt Sulfide Nanotubes and Its Application in Supercapacitors.

PubMed

Liu, Sangui; Mao, Cuiping; Niu, Yubin; Yi, Fenglian; Hou, Junke; Lu, Shiyu; Jiang, Jian; Xu, Maowen; Li, Changming

2015-11-25

Ultralong cobalt sulfide (CoS(1.097)) nanotube networks are synthesized by a simple one-step solvothermal method without any surfactant or template. A possible formation mechanism for the growth processes is proposed. Owing to the hollow structure and large specific area, the novel CoS(1.097) materials present outstanding electrochemical properties. Electrochemical measurements for supercapacitors show that the as-prepared ultralong CoS(1.097) nanotube networks exhibit high specific capacity, good capacity retention, and excellent Coulombic efficiency.

Dual channel sensitive detection of hsa-miR-21 based on rolling circle amplification and quantum dots tagging.

PubMed

Wangt, Dan-Chen; Hu, Li-Hui; Zhou, Yu-Hui; Huang, Yu-Ting; Li, Xinhua; Zhu, Jun-Jie

2014-04-01

An isothermal, highly sensitive and specific assay for the detection of hsa-miR-21 with the integration of QDs tagging and rolling circle amplification was offered. In addition, a dual channel strategy for miRNA detection was proposed: anodic stripping voltammetry (ASV) and fluorescent method were both performed for the final Cd2+ signal readout. The designed strategy exhibited good specificity to hsa-miR-21 and presented comparable detection results by detection methods.

Memory for general and specific value information in younger and older adults: measuring the limits of strategic control.

PubMed

Castel, Alan D; Farb, Norman A S; Craik, Fergus I M

2007-06-01

The ability to selectively remember important information is a critical function of memory. Although previous research has suggested that older adults are impaired in a variety of episodic memory tasks, recent work has demonstrated that older adults can selectively remember high-value information. In the present research, we examined how younger and older adults selectively remembered words with various assigned numeric point values, to see whether younger adults could remember more specific value information than could older adults. Both groups were equally good at recalling point values when recalling the range of high-value words, but younger adults outperformed older adults when recalling specific values. Although older adults were more likely to recognize negative value words, both groups exhibited control by not recalling negative value information. The findings suggest that although both groups retain high-value information, older adults rely more on gist-based encoding and retrieval operations, whereas younger adults are able to remember specific numeric value information.

Hierarchically porous Fe-N-C derived from covalent-organic materials as a highly efficient electrocatalyst for oxygen reduction

NASA Astrophysics Data System (ADS)

Zuo, Quan; Zhao, Pingping; Luo, Wei; Cheng, Gongzhen

2016-07-01

Developing high-performance non-precious catalysts to replace platinum as oxygen reduction reaction (ORR) catalysts is still a big scientific and technological challenge. Herein, we report a simple method for the synthesis of a FeNC catalyst with a 3D hierarchically micro/meso/macro porous network and high surface area through a simple carbonization method by taking the advantages of a high specific surface area and diverse pore dimensions in 3D porous covalent-organic material. The resulting FeNC-900 electrocatalyst with improved reactant/electrolyte transport and sufficient active site exposure, exhibits outstanding ORR activity with a half-wave potential of 0.878 V, ca. 40 mV more positive than Pt/C for ORR in alkaline solution, and a half-wave potential of 0.72 V, which is comparable to that of Pt/C in acidic solution. In particular, the resulting FeNC-900 exhibits a much higher stability and methanol tolerance than those of Pt/C, which makes it among the best non-precious catalysts ever reported for ORR.Developing high-performance non-precious catalysts to replace platinum as oxygen reduction reaction (ORR) catalysts is still a big scientific and technological challenge. Herein, we report a simple method for the synthesis of a FeNC catalyst with a 3D hierarchically micro/meso/macro porous network and high surface area through a simple carbonization method by taking the advantages of a high specific surface area and diverse pore dimensions in 3D porous covalent-organic material. The resulting FeNC-900 electrocatalyst with improved reactant/electrolyte transport and sufficient active site exposure, exhibits outstanding ORR activity with a half-wave potential of 0.878 V, ca. 40 mV more positive than Pt/C for ORR in alkaline solution, and a half-wave potential of 0.72 V, which is comparable to that of Pt/C in acidic solution. In particular, the resulting FeNC-900 exhibits a much higher stability and methanol tolerance than those of Pt/C, which makes it among the best non-precious catalysts ever reported for ORR. Electronic supplementary information (ESI) available: Fig. S1-S12 and Tables S1 and S2. See DOI: 10.1039/c6nr03273g

Freestanding polyaniline nanorods grown on graphene for highly capacitive energy storage

NASA Astrophysics Data System (ADS)

Li, Zijiong; Qin, Zhen; Yang, Baocheng; Guo, Jian; Wang, Haiyan; Zhang, Weiyang; Lv, Xiaowei; Stack, Alison

2015-02-01

Freestanding polyaniline (PANI) nanorods grown in situ on microwave-expanded graphene oxide (MEGO) sheets were prepared through a facile solution method. The morphological characterization indicates that large quantity of free-standing PANI nanorods with average diameter of 50 nm were uniformly deposited onto the double sides of the MEGO nanosheets to form a sandwich structure. The hybrid of PANI/MEGO (GPANI) exhibit high specific surface area and high electrical conductivity, compared with pristine PANI nanorods. When evaluated as electrodes for supercapacitors, the GPANI demonstrate high specific capacitance of 628 F g-1 at a current density of 1.1 A g-1, high-rate performance, and excellent cycle stability compared to individual component. Such excellent electrochemical performance should be attributed to the combined double-layer capacitance and pseudo -capacitance mechanisms from the MEGO sheets and PANI nanorods.

Free-standing porous manganese dioxide/graphene composite films for high performance supercapacitors.

PubMed

Guo, Wang-Huan; Liu, Teng-Jiao; Jiang, Peng; Zhang, Zhan-Jun

2015-01-01

A simple hard template method and hydrothermal process have been employed to fabricate a self-standing hierarchical porous MnO2/graphene film. Thus-constructed electrode materials for binder-free supercapacitors exhibit a high specific capacitance of 266.3 F g(-1) at the density of 0.2 A g(-1). Moreover, the two-electrode device demonstrates an excellent rate capability and cycling stability with capacitance retention of 85.1% after 2000 charge-discharge cycles at a current density of 1 A g(-1). The porous nanostructured design can effectively improve the specific surface areas and account for the shorter relaxation time for the electrodes, resulting in a high electrochemical performance. Copyright © 2014 Elsevier Inc. All rights reserved.

Facile synthesis of Mesoporouscobalt Hexacyanoferrate Nanocubes for High-Performance Supercapacitors

PubMed Central

2017-01-01

Mesoporous cobalt hexacyanoferrate nanocubes (meso–CoHCF) were prepared for the first time through a facile sacrificial template method. The CoHCF mesostructures possess a high specific surface area of 548.5 m2·g−1 and a large amount of mesopores, which enable fast mass transport of electrolyte and abundant energy storage sites. When evaluated as supercapacitor materials, the meso–CoHCF materials exhibit a high specific capacitance of 285 F·g−1, good rate capability and long cycle life with capacitance retention of 92.9% after 3000 cycles in Na2SO4 aqueous electrolyte. The excellent electrochemical properties demonstrate the rational preparation of mesoporous prussian blue and its analogues for energy storage applications. PMID:28825671

3D Freeze-Casting of Cellular Graphene Films for Ultrahigh-Power-Density Supercapacitors.

PubMed

Shao, Yuanlong; El-Kady, Maher F; Lin, Cheng-Wei; Zhu, Guanzhou; Marsh, Kristofer L; Hwang, Jee Youn; Zhang, Qinghong; Li, Yaogang; Wang, Hongzhi; Kaner, Richard B

2016-08-01

3D cellular graphene films with open porosity, high electrical conductivity, and good tensile strength, can be synthesized by a method combining freeze-casting and filtration. The resulting supercapacitors based on 3D porous reduced graphene oxide (RGO) film exhibit extremely high specific power densities and high energy densities. The fabrication process provides an effective means for controlling the pore size, electronic conductivity, and loading mass of the electrode materials, toward devices with high energy-storage performance. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lithium storage in structurally tunable carbon anode derived from sustainable source

DOE PAGES

Lim, Daw Gen; Kim, Kyungho; Razdan, Mayuri; ...

2017-09-01

Here, a meticulous solid state chemistry approach has been developed for the synthesis of carbon anode from a sustainable source. The reaction mechanism of carbon formation during pyrolysis of sustainable feed-stock was studied in situ by employing Raman microspectroscopy. No Raman spectral changes observed below 160°C (thermally stable precursor) followed by color change, however above 280°C characteristic D and G bands of graphitic carbon are recorded. Derived carbon particles exhibited high specific surface area with low structural ordering (active carbons) to low specific surface area with high graphitic ordering as a function of increasing reaction temperature. Carbons synthesized at 600°Cmore » demonstrated enhanced reversible lithiation capacity (390 mAh g -1), high charge-discharge rate capability, and stable cycle life. On the contrary, carbons synthesized at higher temperatures (>1200°C) produced more graphite-like structure yielding longer specific capacity retention with lower reversible capacity.« less

Thin Hydrogel Films for Optical Biosensor Applications

PubMed Central

Mateescu, Anca; Wang, Yi; Dostalek, Jakub; Jonas, Ulrich

2012-01-01

Hydrogel materials consisting of water-swollen polymer networks exhibit a large number of specific properties highly attractive for a variety of optical biosensor applications. This properties profile embraces the aqueous swelling medium as the basis of biocompatibility, non-fouling behavior, and being not cell toxic, while providing high optical quality and transparency. The present review focuses on some of the most interesting aspects of surface-attached hydrogel films as active binding matrices in optical biosensors based on surface plasmon resonance and optical waveguide mode spectroscopy. In particular, the chemical nature, specific properties, and applications of such hydrogel surface architectures for highly sensitive affinity biosensors based on evanescent wave optics are discussed. The specific class of responsive hydrogel systems, which can change their physical state in response to externally applied stimuli, have found large interest as sophisticated materials that provide a complex behavior to hydrogel-based sensing devices. PMID:24957962

Three-dimensional polypyrrole-derived carbon nanotube framework for dye adsorption and electrochemical supercapacitor

NASA Astrophysics Data System (ADS)

Xin, Shengchang; Yang, Na; Gao, Fei; Zhao, Jing; Li, Liang; Teng, Chao

2017-08-01

Three-dimensional carbon nanotube frameworks have been prepared via pyrolysis of polypyrrole nanotube aerogels that are synthesized by the simultaneous self-degraded template synthesis and hydrogel assembly followed by freeze-drying. The microstructure and composition of the materials are investigated by thermal gravimetric analysis, Raman spectrum, X-ray photoelectron spectroscopy, transmission electron microscopy, and specific surface analyzer. The results confirm the formation of three-dimensional carbon nanotube frameworks with low density, high mechanical properties, and high specific surface area. Compared with PPy aerogel precursor, the as-prepared three-dimensional carbon nanotube frameworks exhibit outstanding adsorption capacity towards organic dyes. Moreover, electrochemical tests show that the products possess high specific capacitance, good rate capability and excellent cycling performance with no capacitance loss over 1000 cycles. These characteristics collectively indicate the potential of three-dimensional polypyrrole-derived carbon nanotube framework as a promising macroscopic device for the applications in environmental and energy storages.

Thermal oxidation synthesis hollow MoO{sub 3} microspheres and their applications in lithium storage and gas-sensing

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

Zhao, Xinyu; School of Petrochemical Engineering, Shenyang University of Technology, Liaoyang 111003; Cao, Minhua, E-mail: caomh@bit.edu.cn

2013-06-01

Graphical abstract: MoO{sub 3} hollow microspheres were synthesized via a facile and template-free solvothermal route and subsequent heat treatment in air. The MoO{sub 3} hollow microspheres exhibit an improved lithium storage and gas-sensing performance. Highlights: ► Hollow MoO{sub 3} microspheres were synthesized by thermal oxidation of hollow MoO{sub 2}. ► The MoO{sub 3} hollow microspheres have a relatively high specific surface area. ► The MoO{sub 3} hollow microspheres exhibit improved lithium storage performance. ► The MoO{sub 3} hollow microspheres show good responses to ammonia gas. - Abstract: In this paper, MoO{sub 3} hollow microspheres were synthesized via a facile andmore » template-free solvothermal route and subsequent heat treatment in air. The MoO{sub 3} hollow microspheres have a relatively high specific surface area, and with such a feature, the as-synthesized MoO{sub 3} hollow microspheres have potential applications in Li-ion battery and gas-sensor. When tested as a Li-storage anode material, the MoO{sub 3} hollow microspheres show a higher discharge capacity of 1377.1 mA h g{sup −1} in the first discharge and a high reversible capacity of 780 mA h g{sup −1} after 100 cycles at a rate of 1 C. Furthermore, as a gas sensing material, the MoO{sub 3} hollow microspheres exhibit an improved sensitivity and short response/recovery time to trace levels of ammonia gas.« less

Co(OH)2 nanosheet-decorated graphene–CNT composite for supercapacitors of high energy density

PubMed Central

Cheng, Qian; Tang, Jie; Shinya, Norio; Qin, Lu-Chang

2014-01-01

A composite of graphene and carbon nanotubes has been synthesized and characterized for application as supercapacitor electrodes. By coating the nanostructured active material of Co(OH)2 onto one electrode, the asymmetric supercapacitor has exhibited a high specific capacitance of 310 F g−1, energy density of 172 Wh kg−1 and maximum power density of 198 kW kg−1 in ionic liquid electrolyte EMI-TFSI. PMID:27877633

Co(OH)2 nanosheet-decorated graphene-CNT composite for supercapacitors of high energy density.

PubMed

Cheng, Qian; Tang, Jie; Shinya, Norio; Qin, Lu-Chang

2014-02-01

A composite of graphene and carbon nanotubes has been synthesized and characterized for application as supercapacitor electrodes. By coating the nanostructured active material of Co(OH) 2 onto one electrode, the asymmetric supercapacitor has exhibited a high specific capacitance of 310 F g -1 , energy density of 172 Wh kg -1 and maximum power density of 198 kW kg -1 in ionic liquid electrolyte EMI-TFSI.

Electrochemically synthesized nanocrystalline spinel thin film for high performance supercapacitor

NASA Astrophysics Data System (ADS)

Gupta, Vinay; Gupta, Shubhra; Miura, Norio

Spinels are not known for their supercapacitive nature. Here, we have explored electrochemically synthesized nanostructured NiCo 2O 4 spinel thin-film electrode for electrochemical supercapacitors. The nanostructured NiCo 2O 4 spinel thin film exhibited a high specific capacitance value of 580 F g -1 and an energy density of 32 Wh kg -1 at the power density of 4 kW kg -1, accompanying with good cyclic stability.

High Solids Coating System

DTIC Science & Technology

1980-06-01

environmental pollution and increased worker safety. One formulation, consisting of a combination of Acryloid AU-568 (oxazolidine), NIAX PCP-0300 (polyol), and Desmodur N-100 (polyisocyanate) was developed under the initial contract and found to exhibit performance properties closely approximating the program goals. During the present contract, this formulation was further evaluated. Attempts to upgrade the properties not meeting the performance specifications were made. Also, new commercially available resins were evaluated for incorporation into the high solids

A polyoxovanadate as an advanced electrode material for supercapacitors.

PubMed

Chen, Han-Yi; Wee, Grace; Al-Oweini, Rami; Friedl, Jochen; Tan, Kim Soon; Wang, Yuxi; Wong, Chui Ling; Kortz, Ulrich; Stimming, Ulrich; Srinivasan, Madhavi

2014-07-21

Polyoxovanadate Na(6)V(10)O(28) is investigated for the first time as electrode material for supercapacitors (SCs). The electrochemical properties of Na(6)V(10)O(28) electrodes are studied in Li(+) -containing organic electrolyte (1 M LiClO(4) in propylene carbonate) by galvanostatic charge/discharge and cyclic voltammetry in a three-electrode configuration. Na(6)V(10)O(28) electrodes exhibit high specific capacitances of up to 354 F g(-1). An asymmetric SC with activated carbon as positive electrode and Na(6)V(10)O(28) as negative electrode is fabricated and exhibits a high energy density of 73 Wh kg(-1) with a power density of 312 W kg(-1), which successfully demonstrates that Na(6)V(10)O(28) is a promising electrode material for high-energy SC applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

New developments in thermally stable polymers

NASA Technical Reports Server (NTRS)

Hergenrother, Paul M.

1991-01-01

Advances in high-temperature polymers since 1985 are discussed with the emphasis on the chemistry. High-temperature polymers refer to materials that exhibit glass-transition temperatures greater than 200 C and have the chemical structure expected to provide high thermooxidative stability. Specific polymers or series of polymers were selected to show how the chemical structure influences certain properties. Poly(arylene ethers) and polyimides are the two principal families of polymers discussed. Recent work on poly(arylene ethers) has concentrated on incorporating heterocyclic units within the polymer backbone. Recent polyimide work has centered on the synthesis of new polymers from novel monomers, several containing the trifluoromethyl group strategically located on the molecule. Various members in each of these polymer families display a unique combination of properties, heretofore unattainable. Other families of polymers are also briefly discussed with a polymer from an AB maleimidobenzocyclobutene exhibiting an especially attractive combination of properties.

Popcorn-Derived Porous Carbon for Energy Storage and CO2 Capture.

PubMed

Liang, Ting; Chen, Chunlin; Li, Xing; Zhang, Jian

2016-08-16

Porous carbon materials have drawn tremendous attention due to its applications in energy storage, gas/water purification, catalyst support, and other important fields. However, producing high-performance carbons via a facile and efficient route is still a big challenge. Here we report the synthesis of microporous carbon materials by employing a steam-explosion method with subsequent potassium activation and carbonization of the obtained popcorn. The obtained carbon features a large specific surface area, high porosity, and doped nitrogen atoms. Using as an electrode material in supercapacitor, it displays a high specific capacitance of 245 F g(-1) at 0.5 A g(-1) and a remarkable stability of 97.8% retention after 5000 cycles at 5 A g(-1). The product also exhibits a high CO2 adsorption capacity of 4.60 mmol g(-1) under 1066 mbar and 25 °C. Both areal specific capacitance and specific CO2 uptake are directly proportional to the surface nitrogen content. This approach could thus enlighten the batch production of porous nitrogen-doped carbons for a wide range of energy and environmental applications.

Dual sensitivity of inferior colliculus neurons to ITD in the envelopes of high-frequency sounds: experimental and modeling study

PubMed Central

Wang, Le; Devore, Sasha; Delgutte, Bertrand

2013-01-01

Human listeners are sensitive to interaural time differences (ITDs) in the envelopes of sounds, which can serve as a cue for sound localization. Many high-frequency neurons in the mammalian inferior colliculus (IC) are sensitive to envelope-ITDs of sinusoidally amplitude-modulated (SAM) sounds. Typically, envelope-ITD-sensitive IC neurons exhibit either peak-type sensitivity, discharging maximally at the same delay across frequencies, or trough-type sensitivity, discharging minimally at the same delay across frequencies, consistent with responses observed at the primary site of binaural interaction in the medial and lateral superior olives (MSO and LSO), respectively. However, some high-frequency IC neurons exhibit dual types of envelope-ITD sensitivity in their responses to SAM tones, that is, they exhibit peak-type sensitivity at some modulation frequencies and trough-type sensitivity at other frequencies. Here we show that high-frequency IC neurons in the unanesthetized rabbit can also exhibit dual types of envelope-ITD sensitivity in their responses to SAM noise. Such complex responses to SAM stimuli could be achieved by convergent inputs from MSO and LSO onto single IC neurons. We test this hypothesis by implementing a physiologically explicit, computational model of the binaural pathway. Specifically, we examined envelope-ITD sensitivity of a simple model IC neuron that receives convergent inputs from MSO and LSO model neurons. We show that dual envelope-ITD sensitivity emerges in the IC when convergent MSO and LSO inputs are differentially tuned for modulation frequency. PMID:24155013

Trans-Ethnic Fine-Mapping of Lipid Loci Identifies Population-Specific Signals and Allelic Heterogeneity That Increases the Trait Variance Explained

PubMed Central

Wu, Ying; Waite, Lindsay L.; Jackson, Anne U.; Sheu, Wayne H-H.; Buyske, Steven; Absher, Devin; Arnett, Donna K.; Boerwinkle, Eric; Bonnycastle, Lori L.; Carty, Cara L.; Cheng, Iona; Cochran, Barbara; Croteau-Chonka, Damien C.; Dumitrescu, Logan; Eaton, Charles B.; Franceschini, Nora; Guo, Xiuqing; Henderson, Brian E.; Hindorff, Lucia A.; Kim, Eric; Kinnunen, Leena; Komulainen, Pirjo; Lee, Wen-Jane; Le Marchand, Loic; Lin, Yi; Lindström, Jaana; Lingaas-Holmen, Oddgeir; Mitchell, Sabrina L.; Narisu, Narisu; Robinson, Jennifer G.; Schumacher, Fred; Stančáková, Alena; Sundvall, Jouko; Sung, Yun-Ju; Swift, Amy J.; Wang, Wen-Chang; Wilkens, Lynne; Wilsgaard, Tom; Young, Alicia M.; Adair, Linda S.; Ballantyne, Christie M.; Bůžková, Petra; Chakravarti, Aravinda; Collins, Francis S.; Duggan, David; Feranil, Alan B.; Ho, Low-Tone; Hung, Yi-Jen; Hunt, Steven C.; Hveem, Kristian; Juang, Jyh-Ming J.; Kesäniemi, Antero Y.; Kuusisto, Johanna; Laakso, Markku; Lakka, Timo A.; Lee, I-Te; Leppert, Mark F.; Matise, Tara C.; Moilanen, Leena; Njølstad, Inger; Peters, Ulrike; Quertermous, Thomas; Rauramaa, Rainer; Rotter, Jerome I.; Saramies, Jouko; Tuomilehto, Jaakko; Uusitupa, Matti; Wang, Tzung-Dau; Mohlke, Karen L.

2013-01-01

Genome-wide association studies (GWAS) have identified ∼100 loci associated with blood lipid levels, but much of the trait heritability remains unexplained, and at most loci the identities of the trait-influencing variants remain unknown. We conducted a trans-ethnic fine-mapping study at 18, 22, and 18 GWAS loci on the Metabochip for their association with triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), respectively, in individuals of African American (n = 6,832), East Asian (n = 9,449), and European (n = 10,829) ancestry. We aimed to identify the variants with strongest association at each locus, identify additional and population-specific signals, refine association signals, and assess the relative significance of previously described functional variants. Among the 58 loci, 33 exhibited evidence of association at P<1×10−4 in at least one ancestry group. Sequential conditional analyses revealed that ten, nine, and four loci in African Americans, Europeans, and East Asians, respectively, exhibited two or more signals. At these loci, accounting for all signals led to a 1.3- to 1.8-fold increase in the explained phenotypic variance compared to the strongest signals. Distinct signals across ancestry groups were identified at PCSK9 and APOA5. Trans-ethnic analyses narrowed the signals to smaller sets of variants at GCKR, PPP1R3B, ABO, LCAT, and ABCA1. Of 27 variants reported previously to have functional effects, 74% exhibited the strongest association at the respective signal. In conclusion, trans-ethnic high-density genotyping and analysis confirm the presence of allelic heterogeneity, allow the identification of population-specific variants, and limit the number of candidate SNPs for functional studies. PMID:23555291

Diagnostic accuracy of 3T conventional shoulder MRI in the detection of the long head of the biceps tendon tears associated with rotator cuff tendon tears.

PubMed

Lee, Ro Woon; Choi, Soo-Jung; Lee, Man Ho; Ahn, Jae Hong; Shin, Dong Rock; Kang, Chae Hoon; Lee, Ki Won

2016-12-01

To evaluate the diagnostic performance (DP) of 3T (3 Tesla field strength) conventional shoulder magnetic resonance imaging (MRI) in detecting the long head of the biceps tendon (LHBT) tears in association with rotator cuff tendon tears. This study included 80 consecutive patients who underwent arthroscopic surgery for rotator cuff tendon tears. Two radiologists independently evaluated the preoperative 3T shoulder MRI for the presence of LHBT tears. The DP of MRI was evaluated using the results of arthroscopy as the reference standard. We also evaluated the DP of several MR signs of LHBT in detection of partial LHBT tears. Arthroscopic examination revealed 35 partial and 5 complete tears. According to the results of evaluation by reviewers 1 and 2, shoulder MRI exhibited sensitivities of 77.14 and 80 % and specificities of 71.11 and 73.33 % in detection of partial LHBT tears and sensitivities of 80 and 100 % and a specificity of 100% (both) in detection of complete LHBT tears. In detecting partial LHBT tears, increased T2 signal intensity of the LHBT exhibited high sensitivities (reviewers 1 and 2; 82.85 and 80 %, respectively) and the presence of intratendinous defects or C-signs exhibited the highest specificities (reviewers 1 and 2; 95.55 and 93.33 %, respectively), followed by abnormalities in shape and outer margins of the LHBT (reviewers 1 and 2; 91.11 and 82 %; 91.11 and 86.66 %, respectively). Non-contrast-enhanced 3T shoulder MRI is potentially highly accurate in detection of complete LHBT tears, but moderately accurate in detection of partial LHBT tears.

Serological confirmatory testing of alveolar and cystic echinococcosis in clinical practice: results of a comparative study with commercialized and in-house assays.

PubMed

Reiter-Owona, Ingrid; Grüner, Beate; Frosch, Matthias; Hoerauf, Achim; Kern, Peter; Tappe, Dennis

2009-01-01

Sera of 50 patients with either cystic (CE) or alveolar echinococcosis (AE) in different clinical stages were examined for the presence of anti-Echinococcus-antibodies. Antibody-screening was performed with ELISA, IHA and IFAT, and confirmatory testing was done by the commercialized E. multilocularis-specific Em2plus-ELISA versus an in-house E. multilocularis-specific Em10-ELISA. Sera with discrepant confirmatory results were subjected to a commercial Echinococcus IgG Western blot (WB). In sera from patients with CE, the Em2plus-ELISA showed cross-reactions in 23.5%, whereas the Em10-ELISA did not exhibit any cross-reactivity. Cross-reactivity paralleled active infection with high antibody titers in the screening assays. In sera from patients with AE, confirmation by both ELISAs was achieved in 57.6%, mostly in patients with an advanced stage of the disease and high antibody titers in the screening assays. False-negative reactions of both ELISAs occurred in 30.3%, mostly in patients who had low antibody levels in the screening tests. The Em2plus-ELISA exhibited fewer false-negative reactions than the Em10-ELISA. The WB confirmed the positive results of either assay and was the assay with the highest reliability at different stages of CE and AE, followed by the Em2plus-ELISA for AE. High antibody titers in the screening assays will favour the detection of species-specific antibodies in either form.

Topography and Radiative Forcing Patterns on Glaciers in the Karakoram Himalaya

NASA Astrophysics Data System (ADS)

Dobreva, I. D.; Bishop, M. P.; Liu, J. C.; Liang, D.

2015-12-01

Glaciers in the western Himalaya exhibit significant spatial variations in morphology and dynamics. Climate, topography and debris cover variations are thought to significantly affect glacier fluctuations and glacier sensitivity to climate change, although the role of topography and radiative forcing have not been adequately characterized and related to glacier fluctuations and dynamics. Consequently, we examined the glaciers in the Karakoram Himalaya, as they exhibit high spatial variability in glacier fluctuation rates and ice dynamics including flow velocity and surging. Specifically, we wanted to examine the relationships between these glacier characteristics and temporal patterns of surface irradiance over the ablation season. To accomplish this, we developed and used a rigorous GIS-based solar radiative transfer model that accounts for the direct and diffuse-skylight irradiance components. The model accounts for multiple topographic effects on the magnitude of irradiance reaching glacier surfaces. We specifically used the ASTER GDEM digital elevation model for irradiance simulations. We then examined temporal patterns of irradiance at the grid-cell level to identify the dominant patterns that were used to train a 3-layer artificial neural network. Our results demonstrate that there are unique spatial and temporal patterns associated with downwasting and surging glaciers, and that these patterns partially account for the spatial distribution of advancing and retreating glaciers. Lower-altitude terminus regions of surging glaciers exhibited relatively low surface irradiance values that decreased in magnitude with time, demonstrating that high-velocity surging glaciers facilitate relief production and exhibit steeper surface irradiance gradients with altitude. Collectively, these results demonstrate the important role that local and regional topography play in governing climate-glacier dynamics in the Himalaya.

Fabrication and textural characterization of nanoporous carbon electrodes embedded with CuO nanoparticles for supercapacitors.

PubMed

Prasad, Kumaresa P S; Dhawale, Dattatray S; Sivakumar, Thiripuranthagan; Aldeyab, Salem S; Zaidi, Javaid S M; Ariga, Katsuhiko; Vinu, Ajayan

2011-08-01

We introduce a novel strategy of fabricating nanoporous carbons loaded with different amounts of CuO nanoparticles via a hard templating approach, using copper-containing mesoporous silica as the template and sucrose as the carbon source. The nature and dispersion of the CuO nanoparticles on the surface of the nanoporous carbons were investigated by x-ray diffraction (XRD), high-resolution scanning electron microscopy (HRSEM) and high-resolution transmission electron microscopy (HRTEM). XRD results reveal that nanoporous carbons with embedded CuO nanoparticles exhibit a well-ordered mesoporous structure, whereas the nitrogen adsorption measurements indicate the presence of excellent textural characteristics such as high surface area, large pore volume and uniform pore size distribution. The amount of CuO nanoparticles in the nanochannels of the nanoporous carbon could be controlled by simply varying the Si/Cu molar ratio of the mesoporous silica template. Morphological characterization by SEM and TEM reveals that high-quality CuO nanoparticles are distributed homogeneously within the nanoporous carbon framework. The supercapacitance behavior of the CuO-loaded nanoporous carbons was investigated. The material with a small amount of CuO in the mesochannels and high surface area affords a maximum specific capacitance of 300 F g -1 at a 20 mV s -1 scan rate in an aqueous electrolyte solution. A supercapacitor containing the CuO-loaded nanoporous carbon is highly stable and exhibits a long cycle life with 91% specific capacitance retained after 1000 cycles.

Fabrication and textural characterization of nanoporous carbon electrodes embedded with CuO nanoparticles for supercapacitors

NASA Astrophysics Data System (ADS)

Prasad, Kumaresa P. S.; Dhawale, Dattatray S.; Sivakumar, Thiripuranthagan; Aldeyab, Salem S.; Zaidi, Javaid S. M.; Ariga, Katsuhiko; Vinu, Ajayan

2011-08-01

We introduce a novel strategy of fabricating nanoporous carbons loaded with different amounts of CuO nanoparticles via a hard templating approach, using copper-containing mesoporous silica as the template and sucrose as the carbon source. The nature and dispersion of the CuO nanoparticles on the surface of the nanoporous carbons were investigated by x-ray diffraction (XRD), high-resolution scanning electron microscopy (HRSEM) and high-resolution transmission electron microscopy (HRTEM). XRD results reveal that nanoporous carbons with embedded CuO nanoparticles exhibit a well-ordered mesoporous structure, whereas the nitrogen adsorption measurements indicate the presence of excellent textural characteristics such as high surface area, large pore volume and uniform pore size distribution. The amount of CuO nanoparticles in the nanochannels of the nanoporous carbon could be controlled by simply varying the Si/Cu molar ratio of the mesoporous silica template. Morphological characterization by SEM and TEM reveals that high-quality CuO nanoparticles are distributed homogeneously within the nanoporous carbon framework. The supercapacitance behavior of the CuO-loaded nanoporous carbons was investigated. The material with a small amount of CuO in the mesochannels and high surface area affords a maximum specific capacitance of 300 F g-1 at a 20 mV s-1 scan rate in an aqueous electrolyte solution. A supercapacitor containing the CuO-loaded nanoporous carbon is highly stable and exhibits a long cycle life with 91% specific capacitance retained after 1000 cycles.

Fabrication and textural characterization of nanoporous carbon electrodes embedded with CuO nanoparticles for supercapacitors

PubMed Central

Prasad, Kumaresa P S; Dhawale, Dattatray S; Sivakumar, Thiripuranthagan; Aldeyab, Salem S; Zaidi, Javaid S M; Ariga, Katsuhiko; Vinu, Ajayan

2011-01-01

We introduce a novel strategy of fabricating nanoporous carbons loaded with different amounts of CuO nanoparticles via a hard templating approach, using copper-containing mesoporous silica as the template and sucrose as the carbon source. The nature and dispersion of the CuO nanoparticles on the surface of the nanoporous carbons were investigated by x-ray diffraction (XRD), high-resolution scanning electron microscopy (HRSEM) and high-resolution transmission electron microscopy (HRTEM). XRD results reveal that nanoporous carbons with embedded CuO nanoparticles exhibit a well-ordered mesoporous structure, whereas the nitrogen adsorption measurements indicate the presence of excellent textural characteristics such as high surface area, large pore volume and uniform pore size distribution. The amount of CuO nanoparticles in the nanochannels of the nanoporous carbon could be controlled by simply varying the Si/Cu molar ratio of the mesoporous silica template. Morphological characterization by SEM and TEM reveals that high-quality CuO nanoparticles are distributed homogeneously within the nanoporous carbon framework. The supercapacitance behavior of the CuO-loaded nanoporous carbons was investigated. The material with a small amount of CuO in the mesochannels and high surface area affords a maximum specific capacitance of 300 F g-1 at a 20 mV s-1 scan rate in an aqueous electrolyte solution. A supercapacitor containing the CuO-loaded nanoporous carbon is highly stable and exhibits a long cycle life with 91% specific capacitance retained after 1000 cycles. PMID:27877410

Broadening the cofactor specificity of a thermostable alcohol dehydrogenase using rational protein design introduces novel kinetic transient behavior.

PubMed

Campbell, Elliot; Wheeldon, Ian R; Banta, Scott

2010-12-01

Cofactor specificity in the aldo-keto reductase (AKR) superfamily has been well studied, and several groups have reported the rational alteration of cofactor specificity in these enzymes. Although most efforts have focused on mesostable AKRs, several putative AKRs have recently been identified from hyperthermophiles. The few that have been characterized exhibit a strong preference for NAD(H) as a cofactor, in contrast to the NADP(H) preference of the mesophilic AKRs. Using the design rules elucidated from mesostable AKRs, we introduced two site-directed mutations in the cofactor binding pocket to investigate cofactor specificity in a thermostable AKR, AdhD, which is an alcohol dehydrogenase from Pyrococcus furiosus. The resulting double mutant exhibited significantly improved activity and broadened cofactor specificity as compared to the wild-type. Results of previous pre-steady-state kinetic experiments suggest that the high affinity of the mesostable AKRs for NADP(H) stems from a conformational change upon cofactor binding which is mediated by interactions between a canonical arginine and the 2'-phosphate of the cofactor. Pre-steady-state kinetics with AdhD and the new mutants show a rich conformational behavior that is independent of the canonical arginine or the 2'-phosphate. Additionally, experiments with the highly active double mutant using NADPH as a cofactor demonstrate an unprecedented transient behavior where the binding mechanism appears to be dependent on cofactor concentration. These results suggest that the structural features involved in cofactor specificity in the AKRs are conserved within the superfamily, but the dynamic interactions of the enzyme with cofactors are unexpectedly complex. © 2010 Wiley Periodicals, Inc.

A random PCR screening system for the identification of type 1 human herpes simplex virus.

PubMed

Yu, Xuelian; Shi, Bisheng; Gong, Yan; Zhang, Xiaonan; Shen, Silan; Qian, Fangxing; Gu, Shimin; Hu, Yunwen; Yuan, Zhenghong

2009-10-01

Several viral diseases exhibit measles-like symptoms. Differentiation of suspected cases of measles with molecular epidemiological techniques in the laboratory is useful for measles surveillance. In this study, a random PCR screening system was undertaken for the identification of isolates from patients with measles-like symptoms who exhibited cytopathic effects, but who had negative results for measles virus-specific reverse transcription (RT)-PCR and indirect immunofluorescence assays. Sequence analysis of random amplified PCR products showed that they were highly homologous to type 1 human herpes simplex virus (HSV-1). The results were further confirmed by an HSV-1-specific TaqMan real-time PCR assay. The random PCR screening system described in this study provides an efficient procedure for the identification of unknown viral pathogens. Measles-like symptoms can also be caused by HSV-1, suggesting the need to include HSV-1 in differential diagnoses of measles-like diseases.

Engineering the temporal response of photoconductive photodetectors via selective introduction of surface trap states.

PubMed

Konstantatos, Gerasimos; Levina, Larissa; Fischer, Armin; Sargent, Edward H

2008-05-01

Photoconductive photodetectors fabricated using simple solution-processing have recently been shown to exhibit high gains (>1000) and outstanding sensitivities ( D* > 10(13) Jones). One ostensible disadvantage of exploiting photoconductive gain is that the temporal response is limited by the release of carriers from trap states. Here we show that it is possible to introduce specific chemical species onto the surfaces of colloidal quantum dots to produce only a single, desired trap state having a carefully selected lifetime. In this way we demonstrate a device that exhibits an attractive photoconductive gain (>10) combined with a response time ( approximately 25 ms) useful in imaging. We achieve this by preserving a single surface species, lead sulfite, while eliminating lead sulfate and lead carboxylate. In doing so we preserve the outstanding sensitivity of these devices, achieving a specific detectivity of 10(12) Jones in the visible, while generating a temporal response suited to imaging applications.

Identification and the commitment shift: accounting for gender differences in relationship illusions.

PubMed

Gagné, Faby M; Lydon, John E

2003-07-01

Previous work revealed gender differences in relationship illusions. Women, and not men, perceived their dating partners more favorably than their partners' self-perceptions. In two studies, the authors replicated these findings and showed they are moderated by relationship commitment but not by relationship satisfaction. Dating men low in commitment devalued their partners' virtues, whereas those high in commitment exaggerated their partners' virtues compared to their partners' self-perceptions. In contrast, dating women showed relationship illusions irrespective of their commitment. In Study 2, similar results were obtained with relationship-specific identification. Moreover, men's commitment mediated the effect of identification with the relationship. This suggests that gender differences in relationship identities exist at a general level and that men need to identify with and then commit to a specific relationship before they exhibit pro-relationship thinking, which women exhibit as general dispositions.

Enhancing pseudocapacitive kinetics of nanostructured MnO2 through anchoring onto biomass-derived porous carbon

NASA Astrophysics Data System (ADS)

Chen, Qiongyu; Chen, Jizhang; Zhou, Yuyang; Song, Chao; Tian, Qinghua; Xu, Junling; Wong, Ching-Ping

2018-05-01

The rational construction of heterostructured electrode materials that deliver superior performances to their individual counterparts offers an attractive strategy for supercapacitors. Herein, we anchor low-crystalline nanostructured MnO2 onto soybean stalk-derived carbon matrix through chemical activation and subsequent hydrothermal reaction. The highly porous and conductive matrix can effectively enhance pseudocapacitive kinetics of nanostructured MnO2. Therefore, the obtained nanocomposite exhibits high specific capacitance (384.9 F g-1 at a current density of 0.5 A g-1), great rate capability (185.0 F g-1 at 20 A g-1), and superior cyclability (90.7% capacitance retention after 5000 cycles). Using this nanocomposite as the positive electrode material, an asymmetric supercapacitor (ASC) is assembled, and achieves high specific energy of 34.2 Wh kg-1 and high specific power of 9.58 kW kg-1. The results of this study demonstrate great potential of combining biomass-derived porous carbon with metal oxides.

Co(OH)2/RGO/NiO sandwich-structured nanotube arrays with special surface and synergistic effects as high-performance positive electrodes for asymmetric supercapacitors

NASA Astrophysics Data System (ADS)

Xu, Han; Zhang, Chi; Zhou, Wen; Li, Gao-Ren

2015-10-01

High power density, high energy density and excellent cycling stability are the main requirements for high-performance supercapacitors (SCs) that will be widely used for portable consumer electronics and hybrid electric vehicles. Here we investigate novel types of hybrid Co(OH)2/reduced graphene oxide (RGO)/NiO sandwich-structured nanotube arrays (SNTAs) as positive electrodes for asymmetric supercapacitors (ASCs). The synthesized Co(OH)2/RGO/NiO SNTAs exhibit a significantly improved specific capacity (~1470 F g-1 at 5 mV s-1) and excellent cycling stability with ~98% Csp retention after 10 000 cycles because of the fast transport and short diffusion paths for electroactive species, the high utilization rate of electrode materials, and special synergistic effects among Co(OH)2, RGO, and NiO. The high-performance ASCs are assembled using Co(OH)2/RGO/NiO SNTAs as positive electrodes and active carbon (AC) as negative electrodes, and they exhibit a high energy density (115 Wh kg-1), a high power density (27.5 kW kg-1) and an excellent cycling stability (less 5% Csp loss after 10 000 cycles). This study shows an important breakthrough in the design and fabrication of multi-walled hybrid nanotube arrays as positive electrodes for ASCs.High power density, high energy density and excellent cycling stability are the main requirements for high-performance supercapacitors (SCs) that will be widely used for portable consumer electronics and hybrid electric vehicles. Here we investigate novel types of hybrid Co(OH)2/reduced graphene oxide (RGO)/NiO sandwich-structured nanotube arrays (SNTAs) as positive electrodes for asymmetric supercapacitors (ASCs). The synthesized Co(OH)2/RGO/NiO SNTAs exhibit a significantly improved specific capacity (~1470 F g-1 at 5 mV s-1) and excellent cycling stability with ~98% Csp retention after 10 000 cycles because of the fast transport and short diffusion paths for electroactive species, the high utilization rate of electrode materials, and special synergistic effects among Co(OH)2, RGO, and NiO. The high-performance ASCs are assembled using Co(OH)2/RGO/NiO SNTAs as positive electrodes and active carbon (AC) as negative electrodes, and they exhibit a high energy density (115 Wh kg-1), a high power density (27.5 kW kg-1) and an excellent cycling stability (less 5% Csp loss after 10 000 cycles). This study shows an important breakthrough in the design and fabrication of multi-walled hybrid nanotube arrays as positive electrodes for ASCs. Electronic supplementary information (ESI) available: SEM images, XPS spectra, equivalent circuit, and CVs. See DOI: 10.1039/c5nr04449a

Liver-Specific Deletion of Protein-Tyrosine Phosphatase 1B (PTP1B) Improves Metabolic Syndrome and Attenuates Diet-Induced Endoplasmic Reticulum Stress

PubMed Central

Delibegovic, Mirela; Zimmer, Derek; Kauffman, Caitlin; Rak, Kimberly; Hong, Eun-Gyoung; Cho, You-Ree; Kim, Jason K.; Kahn, Barbara B.; Neel, Benjamin G.; Bence, Kendra K.

2009-01-01

OBJECTIVE—The protein tyrosine phosphatase PTP1B is a negative regulator of insulin signaling; consequently, mice deficient in PTP1B are hypersensitive to insulin. Because PTP1B−/− mice have diminished fat stores, the extent to which PTP1B directly regulates glucose homeostasis is unclear. Previously, we showed that brain-specific PTP1B−/− mice are protected against high-fat diet–induced obesity and glucose intolerance, whereas muscle-specific PTP1B−/− mice have increased insulin sensitivity independent of changes in adiposity. Here we studied the role of liver PTP1B in glucose homeostasis and lipid metabolism. RESEARCH DESIGN AND METHODS—We analyzed body mass/adiposity, insulin sensitivity, glucose tolerance, and lipid metabolism in liver-specific PTP1B−/− and PTP1Bfl/fl control mice, fed a chow or high-fat diet. RESULTS—Compared with normal littermates, liver-specific PTP1B−/− mice exhibit improved glucose homeostasis and lipid profiles, independent of changes in adiposity. Liver-specific PTP1B−/− mice have increased hepatic insulin signaling, decreased expression of gluconeogenic genes PEPCK and G-6-Pase, enhanced insulin-induced suppression of hepatic glucose production, and improved glucose tolerance. Liver-specific PTP1B−/− mice exhibit decreased triglyceride and cholesterol levels and diminished expression of lipogenic genes SREBPs, FAS, and ACC. Liver-specific PTP1B deletion also protects against high-fat diet–induced endoplasmic reticulum stress response in vivo, as evidenced by decreased phosphorylation of p38MAPK, JNK, PERK, and eIF2α and lower expression of the transcription factors C/EBP homologous protein and spliced X box-binding protein 1. CONCLUSIONS—Liver PTP1B plays an important role in glucose and lipid metabolism, independent of alterations in adiposity. Inhibition of PTP1B in peripheral tissues may be useful for the treatment of metabolic syndrome and reduction of cardiovascular risk in addition to diabetes. PMID:19074988

Facile synthesis of highly stable and well-dispersed mesoporous ZrO(2)/carbon composites with high performance in oxidative dehydrogenation of ethylbenzene.

PubMed

Li, Qiang; Xu, Jie; Wu, Zhangxiong; Feng, Dan; Yang, Jianping; Wei, Jing; Wu, Qingling; Tu, Bo; Cao, Yong; Zhao, Dongyuan

2010-09-28

Highly ordered mesoporous ZrO(2)/carbon (FDU-15) composites have been synthesized via a facile evaporation induced triconstituent co-assembly (EISA) approach by using Pluronic F127 as a template and zirconium oxychloride octahydrate and resol as Zr and carbon sources. The synthesized mesoporous composites exhibit a highly ordered two-dimensional (2-D) hexagonal mesostructure with relatively high specific surface areas (up to 947 m(2) g(-1)), pore sizes around 3.8 nm and high pore volumes (up to 0.71 cm(3) g(-1)). The results clearly show that the crystalline zirconia nanoparticles (ca. 1.9-3.9 nm) are well-dispersed in amorphous matrices of the ordered mesoporous carbon FDU-15 materials, which construct the nanocomposites. The ordered mesostructures of the obtained ZrO(2)/FDU-15 composites can be well-retained even at the high pyrolysis temperature (up to 900 degrees C), suggesting a high thermal stability. The zirconia content of the ZrO(2)/FDU-15 composites can be tunable in a wide range (up to 47%). Moreover, the resultant mesoporous ZrO(2)/FDU-15 composites exhibit high catalytic activity in oxidative dehydrogenation (ODH) of ethylbenzene (EB) to styrene (ST), with high ethylbenzene conversion (59.6%) and styrene selectivity (90.4%), which is mainly attributed to the synergistic catalytic effect between the oxygen-containing groups located on the carbon pore walls and weakly basic sites of the nanocrystalline ZrO(2). Furthermore, the high specific surface areas and opening pore channels are also responsible for their high catalytic activity. Therefore, it is a very promising catalyst material in styrene production on an industrial scale.

Language-Dependent Pitch Encoding Advantage in the Brainstem Is Not Limited to Acceleration Rates that Occur in Natural Speech

ERIC Educational Resources Information Center

Krishnan, Ananthanarayan; Gandour, Jackson T.; Smalt, Christopher J.; Bidelman, Gavin M.

2010-01-01

Experience-dependent enhancement of neural encoding of pitch in the auditory brainstem has been observed for only specific portions of native pitch contours exhibiting high rates of pitch acceleration, irrespective of speech or nonspeech contexts. This experiment allows us to determine whether this language-dependent advantage transfers to…

STRAIN-SPECIFIC SENSITIVITY TO INDUCTION OF MURINE LUNG TUMORS FOLLOWING IN UTERO EXPOSURE TO 3-METHYLCHOLANTHRENE

EPA Science Inventory

We previously demonstrated that different strains of fetal mice were more sensitive to lung tumor induction by 3-methylcholanthrene (MC) than were adults. Offspring from either a D2 x B6D2F1 backcross or from parental Balb/c mice exhibited a similar high incidence of lung tumors ...

Both Intrinsic Substrate Preference and Network Context Contribute to Substrate Selection of Classical Tyrosine Phosphatases*

PubMed Central

Tinti, Michele; Paoluzi, Serena; Santonico, Elena; Masch, Antonia; Schutkowski, Mike

2017-01-01

Reversible tyrosine phosphorylation is a widespread post-translational modification mechanism underlying cell physiology. Thus, understanding the mechanisms responsible for substrate selection by kinases and phosphatases is central to our ability to model signal transduction at a system level. Classical protein-tyrosine phosphatases can exhibit substrate specificity in vivo by combining intrinsic enzymatic specificity with the network of protein-protein interactions, which positions the enzymes in close proximity to their substrates. Here we use a high throughput approach, based on high density phosphopeptide chips, to determine the in vitro substrate preference of 16 members of the protein-tyrosine phosphatase family. This approach helped identify one residue in the substrate binding pocket of the phosphatase domain that confers specificity for phosphopeptides in a specific sequence context. We also present a Bayesian model that combines intrinsic enzymatic specificity and interaction information in the context of the human protein interaction network to infer new phosphatase substrates at the proteome level. PMID:28159843

Vertically Oriented and Interpenetrating CuSe Nanosheet Films with Open Channels for Flexible All-Solid-State Supercapacitors

DOE PAGES

Li, Lingzhi; Gong, Jiangfeng; Liu, Chunyan; ...

2017-03-22

As a p-type multifunctional semiconductor, CuSe nanostructures show great promise in optoelectronic, sensing, and photocatalytic fields. Although great progress has been achieved, controllable synthesis of CuSe nanosheets (NSs) with a desirable spacial orientation and open frameworks remains a challenge, and their use in supercapacitors (SCs) has not been explored. Herein, a highly vertically oriented and interpenetrating CuSe NS film with open channels is deposited on an Au-coated polyethylene terephthalate substrate. Such CuSe NS films exhibit high specific capacitance (209 F g–1) and can be used as a carbon black- and binder-free electrode to construct flexible, symmetric all-solid-state SCs, using polyvinylmore » alcohol–LiCl gel as the solid electrolyte. A device fabricated with such CuSe NS films exhibits high volumetric specific capacitance (30.17 mF cm–3), good cycling stability, excellent flexibility, and desirable mechanical stability. The excellent performance of such devices results from the vertically oriented and interpenetrating configuration of CuSe NS building blocks, which can increase the available surface and facilitate the diffusion of electrolyte ions. Moreover, as a prototype for application, three such solid devices in series can be used to light up a red light-emitting diode.« less

High Performance All-solid Supercapacitors Based on the Network of Ultralong Manganese dioxide/Polyaniline Coaxial Nanowires

PubMed Central

Zhou, Junli; Yu, Lin; Liu, Wei; Zhang, Xiaodan; Mu, Wei; Du, Xu; Zhang, Zhe; Deng, Yulin

2015-01-01

In recent years, thin, lightweight and flexible solid supercapacitors are of considerable interest as energy storage devices. Here we demonstrated all-solid supercapacitors (SSCs) with high electrochemical properties, low self-discharge characteristics based on manganese dioxide/polyaniline (MNW/PANI) coaxial nanowire networks. The synergistic effect of MnO2/PANI plus the unique coaxial nanostructure of the ultralong nanowires with a highly interconnected network effectively enhance the conductivity and capacitive performance of the SSCs device. The MNW/PANI composite with 62.5% MnO2 exhibits an outstanding areal specific capacitance reaching 346 mF/cm2 at 5 mV s−1 which is significant higher than most previously reported solid supercapacitors (15.3 mF/cm2–109 mF/cm2) and is close to the that of the best graphene films solid state supercapacitors (372 mF/cm2). In contrast, only 190 mF/cm2 of areal specific capacitance was obtained for the pure MnO2 NW network. The supercapacitors also exhibited low leakage current as small as 20.1 μA, which demonstrated that the MNW/PANI SSCs have great potential for practical applications. PMID:26644364

Identification and Characterization of ML352: A Novel, Noncompetitive Inhibitor of the Presynaptic Choline Transporter

PubMed Central

2015-01-01

The high-affinity choline transporter (CHT) is the rate-limiting determinant of acetylcholine (ACh) synthesis, yet the transporter remains a largely undeveloped target for the detection and manipulation of synaptic cholinergic signaling. To expand CHT pharmacology, we pursued a high-throughput screen for novel CHT-targeted small molecules based on the electrogenic properties of transporter-mediated choline transport. In this effort, we identified five novel, structural classes of CHT-specific inhibitors. Chemical diversification and functional analysis of one of these classes identified ML352 as a high-affinity (Ki = 92 nM) and selective CHT inhibitor. At concentrations that fully antagonized CHT in transfected cells and nerve terminal preparations, ML352 exhibited no inhibition of acetylcholinesterase (AChE) or cholineacetyltransferase (ChAT) and also lacked activity at dopamine, serotonin, and norepinephrine transporters, as well as many receptors and ion channels. ML352 exhibited noncompetitive choline uptake inhibition in intact cells and synaptosomes and reduced the apparent density of hemicholinium-3 (HC-3) binding sites in membrane assays, suggesting allosteric transporter interactions. Pharmacokinetic studies revealed limited in vitro metabolism and significant CNS penetration, with features predicting rapid clearance. ML352 represents a novel, potent, and specific tool for the manipulation of CHT, providing a possible platform for the development of cholinergic imaging and therapeutic agents. PMID:25560927

An evaluation of fiber-reinforced titanium matrix composites for advanced high-temperature aerospace applications

NASA Astrophysics Data System (ADS)

Larsen, James M.; Russ, Stephan M.; Jones, J. W.

1995-12-01

The current capabilities of continuous silicon-carbide fiber-reinforced titanium matrix composites (TMCs) are reviewed with respect to application needs and compared to the capabilities of conventional high-temperature monolithic alloys and aluminides. In particular, the properties of a firstgeneration titanium aluminide composite, SCS-6/Ti-24Al-11Nb, and a second-generation metastable beta alloy composite, SCS-6/TIMETAL 21S, are compared with the nickel-base superalloy IN100, the high-temperature titanium alloy Ti-1100, and a relatively new titanium aluminide alloy. Emphasis is given to life-limiting cyclic and monotonie properties and to the influence of time-dependent deformation and environmental effects on these properties. The composite materials offer a wide range of performance capabilities, depending on laminate architecture. In many instances, unidirectional composites exhibit outstanding properties, although the same materials loaded transverse to the fiber direction typically exhibit very poor properties, primarily due to the weak fiber/matrix interface. Depending on the specific mechanical property under consideration, composite cross-ply laminates often show no improvement over the capability of conventional monolithic materials. Thus, it is essential that these composite materials be tailored to achieve a balance of properties suitable to the specific application needs if these materials are to be attractive candidates to replace more conventional materials.

Vertically Oriented and Interpenetrating CuSe Nanosheet Films with Open Channels for Flexible All-Solid-State Supercapacitors

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

Li, Lingzhi; Gong, Jiangfeng; Liu, Chunyan

As a p-type multifunctional semiconductor, CuSe nanostructures show great promise in optoelectronic, sensing, and photocatalytic fields. Although great progress has been achieved, controllable synthesis of CuSe nanosheets (NSs) with a desirable spacial orientation and open frameworks remains a challenge, and their use in supercapacitors (SCs) has not been explored. Herein, a highly vertically oriented and interpenetrating CuSe NS film with open channels is deposited on an Au-coated polyethylene terephthalate substrate. Such CuSe NS films exhibit high specific capacitance (209 F g–1) and can be used as a carbon black- and binder-free electrode to construct flexible, symmetric all-solid-state SCs, using polyvinylmore » alcohol–LiCl gel as the solid electrolyte. A device fabricated with such CuSe NS films exhibits high volumetric specific capacitance (30.17 mF cm–3), good cycling stability, excellent flexibility, and desirable mechanical stability. The excellent performance of such devices results from the vertically oriented and interpenetrating configuration of CuSe NS building blocks, which can increase the available surface and facilitate the diffusion of electrolyte ions. Moreover, as a prototype for application, three such solid devices in series can be used to light up a red light-emitting diode.« less

N-Doped carbon spheres with hierarchical micropore-nanosheet networks for high performance supercapacitors.

PubMed

Wang, Shoupei; Zhang, Jianan; Shang, Pei; Li, Yuanyuan; Chen, Zhimin; Xu, Qun

2014-10-18

N-doped carbon spheres with hierarchical micropore-nanosheet networks (HPSCSs) were facilely fabricated by a one-step carbonization and activation process of N containing polymer spheres by KOH. With the synergy effect of the multiple structures, HPSCSs exhibit a very high specific capacitance of 407.9 F g(-1) at 1 mV s(-1) (1.2 times higher than that of porous carbon spheres) and a robust cycling stability for supercapacitors.

A highly efficient sorbitol dehydrogenase from Gluconobacter oxydans G624 and improvement of its stability through immobilization

PubMed Central

Kim, Tae-Su; Patel, Sanjay K. S.; Selvaraj, Chandrabose; Jung, Woo-Suk; Pan, Cheol-Ho; Kang, Yun Chan; Lee, Jung-Kul

2016-01-01

A sorbitol dehydrogenase (GoSLDH) from Gluconobacter oxydans G624 (G. oxydans G624) was expressed in Escherichia coli BL21(DE3)-CodonPlus RIL. The complete 1455-bp codon-optimized gene was amplified, expressed, and thoroughly characterized for the first time. GoSLDH exhibited Km and kcat values of 38.9 mM and 3820 s−1 toward L-sorbitol, respectively. The enzyme exhibited high preference for NADP+ (vs. only 2.5% relative activity with NAD+). GoSLDH sequencing, structure analyses, and biochemical studies, suggested that it belongs to the NADP+-dependent polyol-specific long-chain sorbitol dehydrogenase family. GoSLDH is the first fully characterized SLDH to date, and it is distinguished from other L-sorbose-producing enzymes by its high activity and substrate specificity. Isothermal titration calorimetry showed that the protein binds more strongly to D-sorbitol than other L-sorbose-producing enzymes, and substrate docking analysis confirmed a higher turnover rate. The high oxidation potential of GoSLDH for D-sorbitol was confirmed by cyclovoltametric analysis. Further, stability of GoSLDH significantly improved (up to 13.6-fold) after cross-linking of immobilized enzyme on silica nanoparticles and retained 62.8% residual activity after 10 cycles of reuse. Therefore, immobilized GoSLDH may be useful for L-sorbose production from D-sorbitol. PMID:27633501

A highly efficient sorbitol dehydrogenase from Gluconobacter oxydans G624 and improvement of its stability through immobilization.

PubMed

Kim, Tae-Su; Patel, Sanjay K S; Selvaraj, Chandrabose; Jung, Woo-Suk; Pan, Cheol-Ho; Kang, Yun Chan; Lee, Jung-Kul

2016-09-16

A sorbitol dehydrogenase (GoSLDH) from Gluconobacter oxydans G624 (G. oxydans G624) was expressed in Escherichia coli BL21(DE3)-CodonPlus RIL. The complete 1455-bp codon-optimized gene was amplified, expressed, and thoroughly characterized for the first time. GoSLDH exhibited Km and kcat values of 38.9 mM and 3820 s(-1) toward L-sorbitol, respectively. The enzyme exhibited high preference for NADP(+) (vs. only 2.5% relative activity with NAD(+)). GoSLDH sequencing, structure analyses, and biochemical studies, suggested that it belongs to the NADP(+)-dependent polyol-specific long-chain sorbitol dehydrogenase family. GoSLDH is the first fully characterized SLDH to date, and it is distinguished from other L-sorbose-producing enzymes by its high activity and substrate specificity. Isothermal titration calorimetry showed that the protein binds more strongly to D-sorbitol than other L-sorbose-producing enzymes, and substrate docking analysis confirmed a higher turnover rate. The high oxidation potential of GoSLDH for D-sorbitol was confirmed by cyclovoltametric analysis. Further, stability of GoSLDH significantly improved (up to 13.6-fold) after cross-linking of immobilized enzyme on silica nanoparticles and retained 62.8% residual activity after 10 cycles of reuse. Therefore, immobilized GoSLDH may be useful for L-sorbose production from D-sorbitol.

Structural and Functional Analysis of an mRNP Complex That Mediates the High Stability of Human β-Globin mRNA

PubMed Central

Yu, Jia; Russell, J. Eric

2001-01-01

Human globins are encoded by mRNAs exhibiting high stabilities in transcriptionally silenced erythrocyte progenitors. Unlike α-globin mRNA, whose stability is enhanced by assembly of a specific messenger RNP (mRNP) α complex on its 3′ untranslated region (UTR), neither the structure(s) nor the mechanism(s) that effects the high-level stability of human β-globin mRNA has been identified. The present work describes an mRNP complex assembling on the 3′ UTR of the β-globin mRNA that exhibits many of the properties of the stability-enhancing α complex. The β-globin mRNP complex is shown to contain one or more factors homologous to αCP, a 39-kDa RNA-binding protein that is integral to α-complex assembly. Sequence analysis implicates a specific 14-nucleotide pyrimidine-rich track within its 3′ UTR as the site of β-globin mRNP assembly. The importance of this track to mRNA stability is subsequently verified in vivo using mice expressing human β-globin transgenes that contain informative mutations in this region. In combination, the in vitro and in vivo analyses indicate that the high stabilities of the α- and β-globin mRNAs are maintained through related mRNP complexes that may share a common regulatory pathway. PMID:11486027

Understanding Antipsychotic Drug Treatment Effects: A Novel Method to Reduce Pseudospecificity of the Positive and Negative Syndrome Scale (PANSS) Factors.

PubMed

Hopkins, Seth C; Ogirala, Ajay; Loebel, Antony; Koblan, Kenneth S

2017-12-01

The Positive and Negative Syndrome Scale (PANSS) is the most widely used efficacy measure in acute treatment studies of schizophrenia. However, interpretation of the efficacy of antipsychotics in improving specific symptom domains is confounded by moderate-to-high correlations among standard (Marder) PANSS factors. The authors review the results of an uncorrelated PANSS score matrix (UPSM) transform designed to reduce pseudospecificity in assessment of symptom change in patients with schizophrenia. Based on a factor analysis of five pooled, placebo-controlled lurasidone clinical trials (N=1,710 patients), a UPSM transform was identified that generated PANSS factors with high face validity (good correlation with standard Marder PANSS factors), and high specificity/orthogonality (low levels of between-factor correlation measuring change during treatment). Between-factor correlations were low at baseline for both standard (Marder) PANSS factors and transformed PANSS factors. However, when measured change in symptom severity was measured during treatment (in a pooled 5-study analysis), there was a notable difference for standard PANSS factors, where changes across factors were found to be highly correlated (factors exhibited pseudospecificity), compared to transformed PANSS factors, where factor change scores exhibited the same low levels of between-factor correlation observed at baseline. At Week 6-endpoint, correlations among PANSS factor severity scores were moderate-to-high for standard factors (0.34-0.68), but continued to be low for the transformed factors (-0.22-0.20). As an additional validity check, we analyzed data from one of the original five pooled clinical trials that included other well-validated assessment scales (MADRS, Negative Symptom Assessment scale [NSA]). In this baseline analysis, UPSM-transformed PANSS factor severity scores (negative and depression factors) were found to correlate well with the MADRS and NSA. The availability of transformed PANSS factors with a high degree of orthogonality/specificity, but which retain a high degree of concurrent and face validity, can reduce pseudospecificity as a measurement confound, and should facilitate the drug development process, permitting a more accurate characterization of the efficacy of putative new agents in targeting specific symptom domains in patients with psychotic illness.

Hierarchical porous carbon materials derived from petroleum pitch for high-performance supercapacitors

NASA Astrophysics Data System (ADS)

Abudu, Patiman; Wang, Luxiang; Xu, Mengjiao; Jia, Dianzeng; Wang, Xingchao; Jia, Lixia

2018-06-01

In this work, a honeycomb-like carbon material derived from petroleum pitch was synthesized by a simple one-step carbonization/activation method using silica nanospheres as the hard templates. The obtained hierarchical porous carbon materials (HPCs) with a large specific surface area and uniform macropore distribution provide abundant active sites and sufficient ion migration channels. When used as an electrode material for supercapacitors, the HPCs exhibit a high specific capacitance of 341.0 F g-1 at 1 A g-1, excellent rate capability with a capacitance retention of 55.6% at 50 A g-1 (189.5 F g-1), and outstanding cycling performance in the three-electrode system.

New energy storage option: toward ZnCo2O4 nanorods/nickel foam architectures for high-performance supercapacitors.

PubMed

Liu, Bin; Liu, Boyang; Wang, Qiufan; Wang, Xianfu; Xiang, Qingyi; Chen, Di; Shen, Guozhen

2013-10-23

Hierarchical ZnCo2O4/nickel foam architectures were first fabricated from a simple scalable solution approach, exhibiting outstanding electrochemical performance in supercapacitors with high specific capacitance (∼1400 F g(-1) at 1 A g(-1)), excellent rate capability (72.5% capacity retention at 20 A g(-1)), and good cycling stability (only 3% loss after 1000 cycles at 6 A g(-1)). All-solid-state supercapacitors were also fabricated by assembling two pieces of the ZnCo2O4-based electrodes, showing superior performance in terms of high specific capacitance and long cycling stability. Our work confirms that the as-prepared architectures can not only be applied in high energy density fields, but also be used in high power density applications, such as electric vehicles, flexible electronics, and energy storage devices.

A fluid-filled soft robot that exhibits spontaneous switching among versatile spatiotemporal oscillatory patterns inspired by the true slime mold.

PubMed

Umedachi, Takuya; Idei, Ryo; Ito, Kentaro; Ishiguro, Akio

2013-01-01

Behavioral diversity is an essential feature of living systems, enabling them to exhibit adaptive behavior in hostile and dynamically changing environments. However, traditional engineering approaches strive to avoid, or suppress, the behavioral diversity in artificial systems to achieve high performance in specific environments for given tasks. The goals of this research include understanding how living systems exhibit behavioral diversity and using these findings to build lifelike robots that exhibit truly adaptive behaviors. To this end, we have focused on one of the most primitive forms of intelligence concerning behavioral diversity, namely, a plasmodium of true slime mold. The plasmodium is a large amoeba-like unicellular organism that does not possess any nervous system or specialized organs. However, it exhibits versatile spatiotemporal oscillatory patterns and switches spontaneously between these. Inspired by the plasmodium, we built a mathematical model that exhibits versatile oscillatory patterns and spontaneously transitions between these patterns. This model demonstrates that, in contrast to coupled nonlinear oscillators with a well-designed complex diffusion network, physically interacting mechanosensory oscillators are capable of generating versatile oscillatory patterns without changing any parameters. Thus, the results are expected to shed new light on the design scheme for lifelike robots that exhibit amazingly versatile and adaptive behaviors.

Gelatin Nanoparticles with Enhanced Affinity for Calcium Phosphate.

PubMed

Farbod, Kambiz; Diba, Mani; Zinkevich, Tatiana; Schmidt, Stephan; Harrington, Matthew J; Kentgens, Arno P M; Leeuwenburgh, Sander C G

2016-05-01

Gelatin nanoparticles can be tuned with respect to their drug loading efficiency, degradation rate, and release kinetics, which renders these drug carriers highly suitable for a wide variety of biomedical applications. The ease of functionalization has rendered gelatin an interesting candidate material to introduce specific motifs for selective targeting to specific organs, but gelatin nanoparticles have not yet been modified to increase their affinity to mineralized tissue. By means of conjugating bone-targeting alendronate to biocompatible gelatin nanoparticles, a simple method is developed for the preparation of gelatin nanoparticles which exhibit strong affinity to mineralized surfaces. It has been shown that the degree of alendronate functionalization can be tuned by controlling the glutaraldehyde crosslinking density, the molar ratio between alendronate and glutaraldehyde, as well as the pH of the conjugation reaction. Moreover, it has been shown that the affinity of gelatin nanoparticles to calcium phosphate increases considerably upon functionalization with alendronate. In summary, gelatin nanoparticles have been developed, which exhibit great potential for use in bone-specific drug delivery and regenerative medicine. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Organic memory device with self-assembly monolayered aptamer conjugated nanoparticles

NASA Astrophysics Data System (ADS)

Oh, Sewook; Kim, Minkeun; Kim, Yejin; Jung, Hunsang; Yoon, Tae-Sik; Choi, Young-Jin; Jung Kang, Chi; Moon, Myeong-Ju; Jeong, Yong-Yeon; Park, In-Kyu; Ho Lee, Hyun

2013-08-01

An organic memory structure using monolayered aptamer conjugated gold nanoparticles (Au NPs) as charge storage nodes was demonstrated. Metal-pentacene-insulator-semiconductor device was adopted for the non-volatile memory effect through self assembly monolayer of A10-aptamer conjugated Au NPs, which was formed on functionalized insulator surface with prostate-specific membrane antigen protein. The capacitance versus voltage (C-V) curves obtained for the monolayered Au NPs capacitor exhibited substantial flat-band voltage shift (ΔVFB) or memory window of 3.76 V under (+/-)7 V voltage sweep. The memory device format can be potentially expanded to a highly specific capacitive sensor for the aptamer-specific biomolecule detection.

The observed life cycle of a baroclinic instability

NASA Technical Reports Server (NTRS)

Randel, W. J.; Stanford, J. L.

1985-01-01

Medium-scale waves (zonal wavenumbers 4-7) frequently dominate Southern Hemisphere summer circulation patterns. Randel and Stanford have studied the dynamics of these features, demonstrating that the medium-scale waves result from baroclinic excitation and exhibit well-defined life cycles. This study details the evolution of the medium-scale waves during a particular life cycle. The specific case chosen exhibits a high degree of zonal symmetry, prompting study based upon zonally averaged diagnostics. An analysis of the medium-scale wave energetics reveals a well-defined life cycle of baroclinic growth, maturity, and barotropic decay. Eliassen-Palm flux diagrams detail the daily wave structure and its interaction with the zonally-averaged flow.

Proceedings of the 4th International Conference and Exhibition: World Congress on Superconductivity, volume 1

NASA Technical Reports Server (NTRS)

Krishen, Kumar (Editor); Burnham, Calvin (Editor)

1995-01-01

The papers presented at the 4th International Conference Exhibition: World Congress on Superconductivity held at the Marriott Orlando World Center, Orlando, Florida, are contained in this document and encompass the research, technology, applications, funding, political, and social aspects of superconductivity. Specifically, the areas covered included: high-temperature materials; thin films; C-60 based superconductors; persistent magnetic fields and shielding; fabrication methodology; space applications; physical applications; performance characterization; device applications; weak link effects and flux motion; accelerator technology; superconductivity energy; storage; future research and development directions; medical applications; granular superconductors; wire fabrication technology; computer applications; technical and commercial challenges, and power and energy applications.

SILICON CARBIDE GRAIN BOUNDARY DISTRIBUTIONS, IRRADIATION CONDITIONS, AND SILVER RETENTION IN IRRADIATED AGR-1 TRISO FUEL PARTICLES

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

Lillo, T. M.; Rooyen, I. J.; Aguiar, J. A.

Precession electron diffraction in the transmission electron microscope was used to map grain orientation and ultimately determine grain boundary misorientation angle distributions, relative fractions of grain boundary types (random high angle, low angle or coincident site lattice (CSL)-related boundaries) and the distributions of CSL-related grain boundaries in the SiC layer of irradiated TRISO-coated fuel particles. Two particles from the AGR-1 experiment exhibiting high Ag-110m retention (>80%) were compared to a particle exhibiting low Ag-110m retention (<19%). Irradiated particles with high Ag-110m retention exhibited a lower fraction of random, high angle grain boundaries compared to the low Ag-110m retention particle. Anmore » inverse relationship between the random, high angle grain boundary fraction and Ag-110m retention is found and is consistent with grain boundary percolation theory. Also, comparison of the grain boundary distributions with previously reported unirradiated grain boundary distributions, based on SEM-based EBSD for similarly fabricated particles, showed only small differences, i.e. a greater low angle grain boundary fraction in unirradiated SiC. It was, thus, concluded that SiC layers with grain boundary distributions susceptible to Ag-110m release were present prior to irradiation. Finally, irradiation parameters were found to have little effect on the association of fission product precipitates with specific grain boundary types.« less

Mesoporous coaxial titanium nitride-vanadium nitride fibers of core-shell structures for high-performance supercapacitors.

PubMed

Zhou, Xinhong; Shang, Chaoqun; Gu, Lin; Dong, Shanmu; Chen, Xiao; Han, Pengxian; Li, Lanfeng; Yao, Jianhua; Liu, Zhihong; Xu, Hongxia; Zhu, Yuwei; Cui, Guanglei

2011-08-01

In this study, titanium nitride-vanadium nitride fibers of core-shell structures were prepared by the coaxial electrospinning, and subsequently annealed in the ammonia for supercapacitor applications. These core-shell (TiN-VN) fibers incorporated mesoporous structure into high electronic conducting transition nitride hybrids, which combined higher specific capacitance of VN and better rate capability of TiN. These hybrids exhibited higher specific capacitance (2 mV s(-1), 247.5 F g(-1)) and better rate capability (50 mV s(-1), 160.8 F g(-1)), which promise a good candidate for high-performance supercapacitors. It was also revealed by electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS) characterization that the minor capacitance fade originated from the surface oxidation of VN and TiN.

Synthetic Peptides Derived from Bovine Lactoferricin Exhibit Antimicrobial Activity against E. coli ATCC 11775, S. maltophilia ATCC 13636 and S. enteritidis ATCC 13076.

PubMed

Huertas Méndez, Nataly De Jesús; Vargas Casanova, Yerly; Gómez Chimbi, Anyelith Katherine; Hernández, Edith; Leal Castro, Aura Lucia; Melo Diaz, Javier Mauricio; Rivera Monroy, Zuly Jenny; García Castañeda, Javier Eduardo

2017-03-12

Linear, dimeric, tetrameric, and cyclic peptides derived from lactoferricin B-containing non-natural amino acids and the RWQWR motif were synthesized, purified, and characterized using RP-HPLC, MALDI-TOF mass spectrometry, and circular dichroism. The antibacterial activity of peptides against Escherichia coli ATCC 11775, Stenotrophomonas maltophilia ATCC 13636, and Salmonella enteritidis ATCC 13076 was evaluated. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. The synthetic bovine lactoferricin exhibited antibacterial activity against E. coli ATCC 11775 and S. enteritidis ATCC 13076. The dimeric peptide (RRWQWR)₂K-Ahx exhibited the highest antibacterial activity against the tested bacterial strain. The monomeric, cyclic, tetrameric, and palindromic peptides containing the RWQWR motif exhibited high and specific activity against E. coli ATCC 11775. The results suggest that short peptides derived from lactoferricin B could be considered as potential candidates for the development of antibacterial agents against infections caused by E. coli .

Luminescent macrocyclic lanthanide complexes

DOEpatents

Raymond, Kenneth N; Corneillie, Todd M; Xu, Jide

2014-05-20

The present invention provides a novel class of macrocyclic compounds as well as complexes formed between a metal (e.g., lanthanide) ion and the compounds of the invention. Preferred complexes exhibit high stability as well as high quantum yields of lanthanide ion luminescence in aqueous media without the need for secondary activating agents. Preferred compounds incorporate hydroxy-isophthalamide moieties within their macrocyclic structure and are characterized by surprisingly low, non-specific binding to a variety of polypeptides such as antibodies and proteins as well as high kinetic stability. These characteristics distinguish them from known, open-structured ligands.

Two-dimensional ultra-thin SiO(x) (0 < x < 2) nanosheets with long-term cycling stability as lithium ion battery anodes.

PubMed

Sun, Lin; Su, Tingting; Xu, Lei; Liu, Meipin; Du, Hong-Bin

2016-03-21

Ultra-thin SiO(x) (0 < x < 2) nanosheets were obtained via a convenient solvothermal route from a Zintl compound CaSi2. After carbon coating, the SiOx@C nanosheet anodes exhibit high capacity, good rate and superior cycling performance for high-capacity lithium ion battery applications. The specific capacity can be maintained as high as 760 mA h g(-1) with almost no capacity decay after 400 cycles at a current density of 0.5 A g(-1).

Specificity in Sociality: Mice and Prairie Voles Exhibit Different Patterns of Peer Affiliation

PubMed Central

Beery, Annaliese K.; Christensen, Jennifer D; Lee, Nicole S.; Blandino, Katrina L.

2018-01-01

Social behavior is often described as a unified concept, but highly social (group-living) species exhibit distinct social structures and may make different social decisions. Prairie voles (Microtus ochrogaster) are socially monogamous rodents that often reside in extended family groups, and exhibit robust preferences for familiar social partners (same- and opposite-sex) during extended choice tests, although short-term preferences are not known. Mice (Mus musculus) are gregarious and colonial, but in brief laboratory tests of social preference they typically prefer social novelty. This preference for novel vs. familiar peers may represent a species-specific difference in social decision-making between mice and prairie voles. However, the tests used to measure preferences in each species differ markedly in duration and degree of contact, such that the behaviors cannot be directly compared. We assessed whether social preferences for novelty or familiarity differed between mice and prairie voles of both sexes when assessed with matching protocols: the sociability/social preference test (SPT) typically used in mice (short, no direct contact), and the partner preference test (PPT) used in voles (long, direct contact). A subset of voles also underwent a PPT using barriers (long, no direct contact). In the short SPT, behavior did not differ between species. In the longer test, pronounced partner preferences emerged in prairie voles, but mice exhibited no social preferences and rarely huddled. No sex differences were evident in either test. Direct physical contact was required for partner preferences in huddling time in voles, but preference for the partner chamber was evident with or without contact. Both prairie voles and mice are social, but they exhibit important differences in the specificity and extent of their social behavior. While mice are often used to study social approach and other behaviors, voles are a more suitable species for the study of selective social relationships. Consideration of these differences will be important for studies examining the neural mechanisms supporting different kinds of peer social behavior. PMID:29615879

Asymmetric supercapacitor based on flexible TiC/CNF felt supported interwoven nickel-cobalt binary hydroxide nanosheets

NASA Astrophysics Data System (ADS)

Zhou, Gangyong; Xiong, Tianrou; He, Shuijian; Li, Yonghong; Zhu, Yongmei; Hou, Haoqing

2016-06-01

Nanostructured nickel-cobalt binary hydroxide (NiCosbnd BH) is widely investigated as supercapacitor electrode material. However, the aggregation and poor electrical conductivity of NiCosbnd BH limit its practical application as a supercapacitor. In this work, a flexible free-standing hierarchical porous composite composed of NiCosbnd BH nanosheets and titanium carbide-carbon nanofiber (NiCosbnd BH@TiC/CNF) is fabricated through electrospinning and microwave assisted method. The as-prepared composites exhibit desirable electrochemical performances, including high specific capacitance, cycling stability, and rate capability. In particular, the NiCosbnd BH41@TiC/CNF composite electrode exhibits a maximum specific capacitance of 2224 F g-1 at the current density of 0.5 A g-1 and excellent cyclic stability of 91% capacity retention after 3000 cycles at 5.0 A g-1. To expand its practical application, an asymmetric supercapacitor (ASC) is fabricated using the NiCosbnd BH41@TiC/CNF composite as the positive electrode and active carbon as the negative electrode. The ASC exhibits a prominent energy density of 55.93 Wh kg-1 and a high power density of 18,300 W kg-1 at 5.0 A g-1. The superior electrochemical property is attributed to the uniform dispersion of NiCosbnd BH nanosheets on the TiC/CNF felt matrix. The TiC/CNF felt with uniformed TiC nanoparticles makes the fiber surface more suitable for growing NiCosbnd BH nanosheets and simultaneously enhances the conductivity of electrode.

The influence of strategic encoding on false memory in patients with mild cognitive impairment and Alzheimer's disease dementia.

PubMed

Tat, Michelle J; Soonsawat, Anothai; Nagle, Corinne B; Deason, Rebecca G; O'Connor, Maureen K; Budson, Andrew E

2016-11-01

Patients with Alzheimer's disease (AD) dementia exhibit high rates of memory distortions in addition to their impairments in episodic memory. Several investigations have demonstrated that when healthy individuals (young and old) engaged in an encoding strategy that emphasized the uniqueness of study items (an item-specific encoding strategy), they were able to improve their discrimination between old items and unstudied critical lure items in a false memory task. In the present study we examined if patients with AD could also improve their memory discrimination when engaging in an item-specific encoding strategy. Healthy older adult controls, patients with mild cognitive impairment (MCI) due to AD, and patients with mild AD dementia were asked to study lists of categorized words. In the Item-Specific condition, participants were asked to provide a unique detail or personal experience with each study item. In the Relational condition, they were asked to determine how each item in the list was related to the others. To assess the influence of both strategies, recall and recognition memory tests were administered. Overall, both patient groups exhibited poorer memory in both recall and recognition tests compared to controls. In terms of recognition, healthy older controls and patients with MCI due to AD exhibited improved memory discrimination in the Item-Specific condition compared to the Relational condition, whereas patients with AD dementia did not. We speculate that patients with MCI due to AD use intact frontal networks to effectively engage in this strategy. Published by Elsevier Inc.

The influence of strategic encoding on false memory in patients with mild cognitive impairment and Alzheimer’s disease dementia

PubMed Central

Tat, Michelle J.; Soonsawat, Anothai; Nagle, Corinne B.; Deason, Rebecca G.; O’Connor, Maureen K.; Budson, Andrew E.

2018-01-01

Patients with Alzheimer’s disease (AD) dementia exhibit high rates of memory distortions in addition to their impairments in episodic memory. Several investigations have demonstrated that when healthy individuals (young and old) engaged in an encoding strategy that emphasized the uniqueness of study items (an item-specific encoding strategy), they were able to improve their discrimination between old items and unstudied critical lure items in a false memory task. In the present study we examined if patients with AD could also improve their memory discrimination when engaging in an item-specific encoding strategy. Healthy older adult controls, patients with mild cognitive impairment (MCI) due to AD, and patients with mild AD dementia were asked to study lists of categorized words. In the Item-Specific condition, participants were asked to provide a unique detail or personal experience with each study item. In the Relational condition, they were asked to determine how each item in the list was related to the others. To assess the influence of both strategies, recall and recognition memory tests were administered. Overall, both patient groups exhibited poorer memory in both recall and recognition tests compared to controls. In terms of recognition, healthy older controls and patients with MCI due to AD exhibited improved memory discrimination in the Item-Specific condition compared to the Relational condition, whereas patients with AD dementia did not. We speculate that patients with MCI due to AD use intact frontal networks to effectively engage in this strategy. PMID:27643951

Thin-film silicon for flexible metal-air batteries.

PubMed

Garamoun, Ahmed; Schubert, Markus B; Werner, Jürgen H

2014-12-01

Due to its high energy density, theoretical studies propose silicon as a promising candidate material for metal-air batteries. Herein, for the first time, experimental results detail the use of n-type doped amorphous silicon and silicon carbide as fuel in Si-air batteries. Thin-film silicon is particularly interesting for flexible and rolled batteries with high specific energies. Our Si-air batteries exhibit a specific capacity of 269 Ah kg(-1) and an average cell voltage of 0.85 V at a discharge current density of 7.9 μA cm(-2) , corresponding to a specific energy of 229 Wh kg(-1) . Favorably in terms of safety, low concentrated alkaline solution serves as electrolyte. Discharging of the Si-air cells continues as long as there is silicon available for oxidation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Unique processing during a period of high excitation/inhibition balance in adult-born neurons.

PubMed

Marín-Burgin, Antonia; Mongiat, Lucas A; Pardi, M Belén; Schinder, Alejandro F

2012-03-09

The adult dentate gyrus generates new granule cells (GCs) that develop over several weeks and integrate into the preexisting network. Although adult hippocampal neurogenesis has been implicated in learning and memory, the specific role of new GCs remains unclear. We examined whether immature adult-born neurons contribute to information encoding. By combining calcium imaging and electrophysiology in acute slices, we found that weak afferent activity recruits few mature GCs while activating a substantial proportion of the immature neurons. These different activation thresholds are dictated by an enhanced excitation/inhibition balance transiently expressed in immature GCs. Immature GCs exhibit low input specificity that switches with time toward a highly specific responsiveness. Therefore, activity patterns entering the dentate gyrus can undergo differential decoding by a heterogeneous population of GCs originated at different times.

Magnesium/Lithium-Ion Hybrid Battery with High Reversibility by Employing NaV3O8·1.69H2O Nanobelts as a Positive Electrode.

PubMed

Rashad, Muhammad; Li, Xianfeng; Zhang, Huamin

2018-06-27

Recently, magnesium-ion batteries (MIBs) have been under remarkable research focus owing to their appealingly high energy density and natural abundance of magnesium. Nevertheless, MIBs exhibit a very limited performance because of sluggish solid-state Mg 2+ ion diffusion and high polarizability, which hinder their progress toward commercialization. Herein, we report a Mg 2+ /Li + hybrid-ion battery (MLIB) with NaV 3 O 8 ·1.69H 2 O (NVO) nanobelts synthesized at room temperature working as the positive electrode. In the hybrid-ion system, Li + intercalates/deintercalates along with a small amount of Mg 2+ adsorption at the NVO cathode, whereas the anode side of the cell is dominated by Mg 2+ deposition/dissolution. As a result, the MLIB exhibits a much higher rate capability (i.e., 446 mA h g -1 at 20 mA g -1 ) than the previously reported MLIBs. MLIB maintains a high specific capacity of 200 mA h g -1 at 80 mA g -1 for 150 cycles, showing excellent stability. Moreover, the effect of different Li-ion concentrations (i.e., 0.5-2.0 M) in the electrolyte and cutoff voltage (ranging from 2 to 2.6 V) on the specific capacities are investigated. The current study highlights a strategy to exploit the Mg 2+ /Li + hybrid electrolyte system with various electrode materials for high-performance MIBs.

Enhanced aging properties of HKUST-1 in hydrophobic mixed-matrix membranes for ammonia adsorption.

PubMed

DeCoste, Jared B; Denny, Michael S; Peterson, Gregory W; Mahle, John J; Cohen, Seth M

2016-04-21

Metal-organic frameworks (MOFs) in their free powder form have exhibited superior capacities for many gases when compared to other materials, due to their tailorable functionality and high surface areas. Specifically, the MOF HKUST-1 binds small Lewis bases, such as ammonia, with its coordinatively unsaturated copper sites. We describe here the use of HKUST-1 in mixed-matrix membranes (MMMs) prepared from polyvinylidene difluoride (PVDF) for the removal of ammonia gas. These MMMs exhibit ammonia capacities similar to their hypothetical capacities based on the weight percent of HKUST-1 in each MMM. HKUST-1 in its powder form is unstable toward humid conditions; however, upon exposure to humid environments for prolonged periods of time, the HKUST-1 MMMs exhibit outstanding structural stability, and maintain their ammonia capacity. Overall, this study has achieved all of the critical and combined elements for real-world applications of MOFs: high MOF loadings, fully accessible MOF surfaces, enhanced MOF stabilization, recyclability, mechanical stability, and processability. This study is a critical step in advancing MOFs to a stable, usable, and enabling technology.

Carbohydrazide-dependent reductant for preparing nitrogen-doped graphene hydrogels as electrode materials in supercapacitor

NASA Astrophysics Data System (ADS)

Jiang, Man; Xing, Ling-Bao; Zhang, Jing-Li; Hou, Shu-Fen; Zhou, Jin; Si, Weijiang; Cui, Hongyou; Zhuo, Shuping

2016-04-01

Three-dimensional (3D) nitrogen-doped graphene hydrogels (NGHs) are designed and synthesized in an efficient and fast way by using a strong reductant of carbohydrazide as reducing and doping agent in an aqueous solution of graphene oxide (GO). The transformation of GO suspension to the hydrogels can be completed in 1 h, which can be confirmed by X-ray powder diffraction (XRD), Raman spectroscopy, and Fourier transform infrared spectroscopy (FT-IR). With adding different amounts of carbohydrazide, the obtained NGHs behave different doping of N and unlike performances in supercapacitors, which can be demonstrated by elemental analysis and X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), N2 sorption experiments, and electrochemical measurements, respectively. According to the network architectures, the NGHs all exhibited high specific capacitance, NGHs-1, NGHs-2, NGHs-5 and NGHs-10 showed specific capacitance at 167.7, 156.8, 140.4 and 119.3 F g-1 at 1 A g-1 in KOH electrolyte. The specific capacitance can still be maintained for 80.5, 79.5, 80.3 and 78.6% with an increase of the discharging current density of 10 A g-1, respectively. More interestingly, the NGHs-1 based supercapacitor also exhibited good electrochemical stability and high degree of reversibility in the long-term cycling test (81.5% retention after 4000 cycles).

Facile one-step synthesis of nanocomposite based on carbon nanotubes and Nickel-Aluminum layered double hydroxides with high cycling stability for supercapacitors.

PubMed

Bai, Caihui; Sun, Shiguo; Xu, Yongqian; Yu, Ruijin; Li, Hongjuan

2016-10-15

Nickel-Aluminum Layered Double Hydroxide (NiAl-LDH) and nanocomposite of Carbon Nanotubes (CNTs) and NiAl-LDH (CNTs/NiAl-LDH) were prepared by using a facile one-step homogeneous precipitation approach. The morphology, structure and electrochemical properties of the as-prepared CNTs/NiAl-LDH nanocomposite were then systematically studied. According to the galvanostatic charge-discharge curves, the CNTs/NiAl-LDH nanocomposite exhibited a high specific capacitance of 694Fg(-1) at the 1Ag(-1). Furthermore, the specific capacitance of the CNTs/NiAl-LDH nanocomposite still retained 87% when the current density was increased from 1 to 10Ag(-1). These results indicated that the CNTs/NiAl-LDH nanocomposite displayed a higher specific capacitance and rate capability than pure NiAl-LDH. And the participation of CNTs in the NiAl-LDH composite improved the electrochemical properties. Additionally, the capacitance of the CNTs/NiAl-LDH nanocomposite kept at least 92% after 3000cycles at 20Ag(-1), suggesting that the nanocomposite exhibited excellent cycling durability. This strategy provided a facile and effective approach for the synthesis of nanocomposite based on CNTs and NiAl-LDH with enhanced supercapacitor behaviors, which can be potentially applied in energy storage conversion devices. Copyright © 2016 Elsevier Inc. All rights reserved.

Broad neutralization response in a subset of HIV-1 subtype C-infected viraemic non-progressors from southern India.

PubMed

Nandagopal, Paneerselvam; Bhattacharya, Jayanta; Srikrishnan, Aylur K; Goyal, Rajat; Ravichandran Swathirajan, Chinnambedu; Patil, Shilpa; Saravanan, Shanmugam; Deshpande, Suprit; Vignesh, Ramachandran; Solomon, Sunil Suhas; Singla, Nikhil; Mukherjee, Joyeeta; Murugavel, Kailapuri G

2018-02-05

Broadly neutralizing antibodies (bnAbs) have been considered to be potent therapeutic tools and potential vaccine candidates to enable protection against various clades of human immunodeficiency virus (HIV). The generation of bnAbs has been associated with enhanced exposure to antigen, high viral load and low CD4+ T cell counts, among other factors. However, only limited data are available on the generation of bnAbs in viraemic non-progressors that demonstrate moderate to high viraemia. Further, since HIV-1 subtype C viruses account for more than 50 % of global HIV infections, the identification of bnAbs with novel specificities is crucial to enable the development of potent tools to aid in HIV therapy and prevention. In the present study, we analysed and compared the neutralization potential of responses in 70 plasma samples isolated from ART-naïve HIV-1 subtype C-infected individuals with various disease progression profiles against a panel of 30 pseudoviruses. Among the seven samples that exhibited a neutralization breadth of ≥70 %, four were identified as 'elite neutralizers', and three of these were from viraemic non-progressors while the fourth was from a typical progressor. Analysis of the neutralization specificities revealed that none of the four elite neutralizers were reactive to epitopes in the membrane proximal external region (MPER), CD4-binding site and V1V2 or V3 glycan. However, two of the four elite neutralizers exhibited enhanced sensitivity towards viruses lacking N332 glycan, indicating high neutralization potency. Overall, our findings indicate that the identification of potent neutralization responses with distinct epitope specificities is possible from the as yet unexplored Indian population, which has a high prevalence of HIV-1 subtype C infection.

Unconventional microarray design reveals the response to obesity is largely tissue specific: analysis of common and divergent responses to diet-induced obesity in insulin-sensitive tissues.

PubMed

Lee, Robyn K; Hittel, Dustin S; Nyamandi, Vongai Z; Kang, Li; Soh, Jung; Sensen, Christoph W; Shearer, Jane

2012-04-01

Obesity is a chronic condition involving the excessive accumulation of adipose tissue that adversely affects all systems in the body. The aim of the present study was to employ an unbiased, genome-wide assessment of transcript abundance in order to identify common gene expression pathways within insulin-sensitive tissues in response to dietary-induced diabetes. Following 20 weeks of chow or high-fat feeding (60% kcal), age-matched mice underwent a euglycemic-hyperinsulinemic clamp to assess insulin sensitivity. High-fat-fed animals were obese and highly insulin resistant, disposing of ∼75% less glucose compared with their chow-fed counterparts. Tissues were collected, and gene expression was examined by microarray in 4 tissues known to exhibit obesity-related metabolic disturbances: white adipose tissue, skeletal muscle, liver, and heart. A total of 463 genes were differentially expressed between diets. Analysis of individual tissues showed skeletal muscle to exhibit the largest number of differentially expressed genes (191) in response to high-fat feeding, followed by adipose tissue (169), liver (115), and heart (65). Analyses revealed that the response of individual genes to obesity is distinct and largely tissue specific, with less than 10% of transcripts being shared among tissues. Although transcripts are largely tissue specific, a systems approach shows numerous commonly activated pathways, including those involved in signal transduction, inflammation, oxidative stress, substrate transport, and metabolism. This suggests a coordinated attempt by tissues to limit metabolic perturbations occurring in early-stage obesity. Many identified genes were associated with a variety of disorders, thereby serving as potential links between obesity and its related health risks.

From Goal-Oriented Requirements to Event-B Specifications

NASA Technical Reports Server (NTRS)

Aziz, Benjamin; Arenas, Alvaro E.; Bicarregui, Juan; Ponsard, Christophe; Massonet, Philippe

2009-01-01

In goal-oriented requirements engineering methodologies, goals are structured into refinement trees from high-level system-wide goals down to fine-grained requirements assigned to specific software/ hardware/human agents that can realise them. Functional goals assigned to software agents need to be operationalised into specification of services that the agent should provide to realise those requirements. In this paper, we propose an approach for operationalising requirements into specifications expressed in the Event-B formalism. Our approach has the benefit of aiding software designers by bridging the gap between declarative requirements and operational system specifications in a rigorous manner, enabling powerful correctness proofs and allowing further refinements down to the implementation level. Our solution is based on verifying that a consistent Event-B machine exhibits properties corresponding to requirements.

Structure-Based Engineering of an Artificially Generated NADP+-Dependent d-Amino Acid Dehydrogenase.

PubMed

Hayashi, Junji; Seto, Tomonari; Akita, Hironaga; Watanabe, Masahiro; Hoshino, Tamotsu; Yoneda, Kazunari; Ohshima, Toshihisa; Sakuraba, Haruhiko

2017-06-01

A stable NADP + -dependent d-amino acid dehydrogenase (DAADH) was recently created from Ureibacillus thermosphaericus meso -diaminopimelate dehydrogenase through site-directed mutagenesis. To produce a novel DAADH mutant with different substrate specificity, the crystal structure of apo-DAADH was determined at a resolution of 1.78 Å, and the amino acid residues responsible for the substrate specificity were evaluated using additional site-directed mutagenesis. By introducing a single D94A mutation, the enzyme's substrate specificity was dramatically altered; the mutant utilized d-phenylalanine as the most preferable substrate for oxidative deamination and had a specific activity of 5.33 μmol/min/mg at 50°C, which was 54-fold higher than that of the parent DAADH. In addition, the specific activities of the mutant toward d-leucine, d-norleucine, d-methionine, d-isoleucine, and d-tryptophan were much higher (6 to 25 times) than those of the parent enzyme. For reductive amination, the D94A mutant exhibited extremely high specific activity with phenylpyruvate (16.1 μmol/min/mg at 50°C). The structures of the D94A-Y224F double mutant in complex with NADP + and in complex with both NADPH and 2-keto-6-aminocapronic acid (lysine oxo-analogue) were then determined at resolutions of 1.59 Å and 1.74 Å, respectively. The phenylpyruvate-binding model suggests that the D94A mutation prevents the substrate phenyl group from sterically clashing with the side chain of Asp94. A structural comparison suggests that both the enlarged substrate-binding pocket and enhanced hydrophobicity of the pocket are mainly responsible for the high reactivity of the D94A mutant toward the hydrophobic d-amino acids with bulky side chains. IMPORTANCE In recent years, the potential uses for d-amino acids as source materials for the industrial production of medicines, seasonings, and agrochemicals have been growing. To date, several methods have been used for the production of d-amino acids, but all include tedious steps. The use of NAD(P) + -dependent d-amino acid dehydrogenase (DAADH) makes single-step production of d-amino acids from oxo-acid analogs and ammonia possible. We recently succeeded in creating a stable DAADH and demonstrated that it is applicable for one-step synthesis of d-amino acids, such as d-leucine and d-isoleucine. As the next step, the creation of an enzyme exhibiting different substrate specificity and higher catalytic efficiency is a key to the further development of d-amino acid production. In this study, we succeeded in creating a novel mutant exhibiting extremely high catalytic activity for phenylpyruvate amination. Structural insight into the mutant will be useful for further improvement of DAADHs. Copyright © 2017 American Society for Microbiology.

Structure-Based Engineering of an Artificially Generated NADP+-Dependent d-Amino Acid Dehydrogenase

PubMed Central

Hayashi, Junji; Seto, Tomonari; Akita, Hironaga; Watanabe, Masahiro; Hoshino, Tamotsu; Yoneda, Kazunari; Ohshima, Toshihisa

2017-01-01

ABSTRACT A stable NADP+-dependent d-amino acid dehydrogenase (DAADH) was recently created from Ureibacillus thermosphaericus meso-diaminopimelate dehydrogenase through site-directed mutagenesis. To produce a novel DAADH mutant with different substrate specificity, the crystal structure of apo-DAADH was determined at a resolution of 1.78 Å, and the amino acid residues responsible for the substrate specificity were evaluated using additional site-directed mutagenesis. By introducing a single D94A mutation, the enzyme's substrate specificity was dramatically altered; the mutant utilized d-phenylalanine as the most preferable substrate for oxidative deamination and had a specific activity of 5.33 μmol/min/mg at 50°C, which was 54-fold higher than that of the parent DAADH. In addition, the specific activities of the mutant toward d-leucine, d-norleucine, d-methionine, d-isoleucine, and d-tryptophan were much higher (6 to 25 times) than those of the parent enzyme. For reductive amination, the D94A mutant exhibited extremely high specific activity with phenylpyruvate (16.1 μmol/min/mg at 50°C). The structures of the D94A-Y224F double mutant in complex with NADP+ and in complex with both NADPH and 2-keto-6-aminocapronic acid (lysine oxo-analogue) were then determined at resolutions of 1.59 Å and 1.74 Å, respectively. The phenylpyruvate-binding model suggests that the D94A mutation prevents the substrate phenyl group from sterically clashing with the side chain of Asp94. A structural comparison suggests that both the enlarged substrate-binding pocket and enhanced hydrophobicity of the pocket are mainly responsible for the high reactivity of the D94A mutant toward the hydrophobic d-amino acids with bulky side chains. IMPORTANCE In recent years, the potential uses for d-amino acids as source materials for the industrial production of medicines, seasonings, and agrochemicals have been growing. To date, several methods have been used for the production of d-amino acids, but all include tedious steps. The use of NAD(P)+-dependent d-amino acid dehydrogenase (DAADH) makes single-step production of d-amino acids from oxo-acid analogs and ammonia possible. We recently succeeded in creating a stable DAADH and demonstrated that it is applicable for one-step synthesis of d-amino acids, such as d-leucine and d-isoleucine. As the next step, the creation of an enzyme exhibiting different substrate specificity and higher catalytic efficiency is a key to the further development of d-amino acid production. In this study, we succeeded in creating a novel mutant exhibiting extremely high catalytic activity for phenylpyruvate amination. Structural insight into the mutant will be useful for further improvement of DAADHs. PMID:28363957

Mapping the Tail Fiber as the Receptor Binding Protein Responsible for Differential Host Specificity of Pseudomonas aeruginosa Bacteriophages PaP1 and JG004

PubMed Central

Le, Shuai; He, Xuesong; Tan, Yinling; Huang, Guangtao; Zhang, Lin; Lux, Renate; Shi, Wenyuan; Hu, Fuquan

2013-01-01

The first step in bacteriophage infection is recognition and binding to the host receptor, which is mediated by the phage receptor binding protein (RBP). Different RBPs can lead to differential host specificity. In many bacteriophages, such as Escherichia coli and Lactococcal phages, RBPs have been identified as the tail fiber or protruding baseplate proteins. However, the tail fiber-dependent host specificity in Pseudomonas aeruginosa phages has not been well studied. This study aimed to identify and investigate the binding specificity of the RBP of P. aeruginosa phages PaP1 and JG004. These two phages share high DNA sequence homology but exhibit different host specificities. A spontaneous mutant phage was isolated and exhibited broader host range compared with the parental phage JG004. Sequencing of its putative tail fiber and baseplate region indicated a single point mutation in ORF84 (a putative tail fiber gene), which resulted in the replacement of a positively charged lysine (K) by an uncharged asparagine (N). We further demonstrated that the replacement of the tail fiber gene (ORF69) of PaP1 with the corresponding gene from phage JG004 resulted in a recombinant phage that displayed altered host specificity. Our study revealed the tail fiber-dependent host specificity in P. aeruginosa phages and provided an effective tool for its alteration. These contributions may have potential value in phage therapy. PMID:23874674

Nonparametric Multiple Imputation for Questionnaires with Individual Skip Patterns and Constraints: The Case of Income Imputation in The National Educational Panel Study

ERIC Educational Resources Information Center

Aßmann, Christian; Würbach, Ariane; Goßmann, Solange; Geissler, Ferdinand; Bela, Anika

2017-01-01

Large-scale surveys typically exhibit data structures characterized by rich mutual dependencies between surveyed variables and individual-specific skip patterns. Despite high efforts in fieldwork and questionnaire design, missing values inevitably occur. One approach for handling missing values is to provide multiply imputed data sets, thus…

Lithographically defined microporous carbon structures

DOEpatents

Burckel, David Bruce; Washburn, Cody M.; Polsky, Ronen; Brozik, Susan M.; Wheeler, David R.

2013-01-08

A lithographic method is used to fabricate porous carbon structures that can provide electrochemical electrodes having high surface area with uniform and controllable dimensions, providing enormous flexibility to tailor the electrodes toward specific applications. Metal nanoparticles deposited on the surface of the porous carbon electrodes exhibit ultra small dimensions with uniform size distribution. The resulting electrodes are rugged, electrically conductive and show excellent electrochemical behavior.

Synthesis of Perfluorinated Polymers

NASA Technical Reports Server (NTRS)

Rosser, R. W.; Psarras, T.

1982-01-01

Long-chain perfluoropolyethers containing functional pendent groups were investigated as possible candidates for new sealants and elastomers that function in extreme environments. Of specific interest was development of materials exhibiting high thermal and oxidative stability at temperatures around 400 degrees C, low-temperature flexibility with glass transition at about 50 degrees C, and hydrolytic stability as well as compatibility with metals and resistance to fuels.

Discovery of a potent and highly specific β2 proteasome inhibitor from a library of copper complexes.

PubMed

Zhou, Tongliang; Cai, Yuanbo; Liang, Lei; Yang, Lingfei; Xu, Fengrong; Niu, Yan; Wang, Chao; Zhang, Jun-Long; Xu, Ping

2016-12-01

We reported the synthesis, characterization and biological activity of several copper(II) Schiff base complexes, which exhibit high proteasome inhibitory activities with particular selectivity of β 2 subunit. Structure-activity relationships information obtained from complex Na 2 [Cu(a4s1)] demonstrated that distinct bonding modes in β 2 and β 5 subunits determines its selectivity and potent inhibition for β 2 subunit. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

Liu, Jue; Zeng, Min, E-mail: min-zeng@buaa.edu.cn, E-mail: rhyu@buaa.edu.cn; Dong, Hangrong

Flower-like Fe{sub 3}O{sub 4}/Bi{sub 2}MoO{sub 6} has been prepared via a facile two-step thermosynthesis method. The composite displays high photocatalytic activity in Rhodamine B decomposition under visible light irradiation. Bi{sub 2}MoO{sub 6} with flower-like structure that has high specific surface area guarantees excellent photocatalytic performance. Fe{sub 3}O{sub 4} retards electron-hole recombination that contributes to photocatalytic property. Further, the stable composite exhibits remarkable reusability due to the incorporation of magnetic particle.

An efficient synthesis strategy for metal-organic frameworks: Dry-gel synthesis of MOF-74 framework with high yield and improved performance

DOE PAGES

Das, Atanu Kumar; Vemuri, Rama Sesha; Kutnyakov, Igor; ...

2016-06-16

Here, vapor-assisted dry-gel synthesis of MOF-74 structure, specifically NiMOF-74 from its synthetic precursors, was conducted with high yield and improved performance showing promise for gas (CO 2) and water adsorption applications. Unlike conventional synthesis, which takes 72 h, this kinetic study showed that NiMOF-74 forms within 12 h under dry-gel conditions with similar performance characteristics and exhibits the best performance characteristics after 48 h of heating.

Influence of uranium on bacterial communities: a comparison of natural uranium-rich soils with controls.

PubMed

Mondani, Laure; Benzerara, Karim; Carrière, Marie; Christen, Richard; Mamindy-Pajany, Yannick; Février, Laureline; Marmier, Nicolas; Achouak, Wafa; Nardoux, Pascal; Berthomieu, Catherine; Chapon, Virginie

2011-01-01

This study investigated the influence of uranium on the indigenous bacterial community structure in natural soils with high uranium content. Radioactive soil samples exhibiting 0.26% - 25.5% U in mass were analyzed and compared with nearby control soils containing trace uranium. EXAFS and XRD analyses of soils revealed the presence of U(VI) and uranium-phosphate mineral phases, identified as sabugalite and meta-autunite. A comparative analysis of bacterial community fingerprints using denaturing gradient gel electrophoresis (DGGE) revealed the presence of a complex population in both control and uranium-rich samples. However, bacterial communities inhabiting uraniferous soils exhibited specific fingerprints that were remarkably stable over time, in contrast to populations from nearby control samples. Representatives of Acidobacteria, Proteobacteria, and seven others phyla were detected in DGGE bands specific to uraniferous samples. In particular, sequences related to iron-reducing bacteria such as Geobacter and Geothrix were identified concomitantly with iron-oxidizing species such as Gallionella and Sideroxydans. All together, our results demonstrate that uranium exerts a permanent high pressure on soil bacterial communities and suggest the existence of a uranium redox cycle mediated by bacteria in the soil.

Changes in community-level riparian plant traits over inundation gradients, Colorado River, Grand Canyon

USGS Publications Warehouse

McCoy-Sulentic, Miles; Kolb, Thomas; Merritt, David; Palmquist, Emily C.; Ralston, Barbara E.; Sarr, Daniel; Shafroth, Patrick B.

2017-01-01

Comparisons of community-level functional traits across environmental gradients have potential for identifying links among plant characteristics, adaptations to stress and disturbance, and community assembly. We investigated community-level variation in specific leaf area (SLA), plant mature height, seed mass, stem specific gravity (SSG), relative cover of C4 species, and total plant cover over hydrologic zones and gradients in years 2013 and 2014 in the riparian plant community along the Colorado River in the Grand Canyon. Vegetation cover was lowest in the frequently inundated active channel zone, indicating constraints on plant establishment and production by flood disturbance and anaerobic stress. Changes in trait values over hydrologic zones and inundation gradients indicate that frequently inundated plots exhibit a community-level ruderal strategy with adaptation to submergence (high SLA and low SSG, height, seed mass, C4 relative cover), whereas less frequently inundated plots exhibit adaptation to drought and infrequent flood disturbance (low SLA and high SSG, height, seed mass, C4 relative cover). Variation in traits not associated with inundation suggests niche differentiation and multiple modes of community assembly. The results enhance understanding of future responses of riparian communities of the Grand Canyon to anticipated drying and changes in hydrologic regime.

Ultrasensitive Visual Detection of HIV DNA Biomarkers via a Multi-amplification Nanoplatform.

PubMed

Long, Yuyin; Zhou, Cuisong; Wang, Congmin; Cai, Honglian; Yin, Cuiyun; Yang, Qiufang; Xiao, Dan

2016-04-01

Methodologies to detect disease biomarkers at ultralow concentrations can potentially improve the standard of living. A facile and label-free multi-amplification strategy is proposed for the ultrasensitive visual detection of HIV DNA biomarkers in real physiological media. This multi-amplification strategy not only exhibits a signficantly low detection limit down to 4.8 pM but also provides a label-free, cost-effective and facile technique for visualizing a few molecules of nucleic acid analyte with the naked eye. Importantly, the biosensor is capable of discriminating single-based mismatch lower than 5.0 nM in human serum samples. Moreover, the visual sensing platform exhibits excellent specificity, acceptable reusability and a long-term stability. All these advantages could be attributed to the nanofibrous sensing platform that 1) has a high surface-area-to-volume provided by electrospun nanofibrous membrane, and 2) combines glucose oxidase (GOx) biocatalysis, DNAzyme-catalyzed colorimetric reaction and catalytic hairpin assembly (CHA) recycling amplification together. This multi-amplification nanoplatform promises label-free and visual single-based mismatch DNA monitoring with high sensitivity and specificity, suggesting wide applications that range from virus detection to genetic disease diagnosis.

Influence of Uranium on Bacterial Communities: A Comparison of Natural Uranium-Rich Soils with Controls

PubMed Central

Mondani, Laure; Benzerara, Karim; Carrière, Marie; Christen, Richard; Mamindy-Pajany, Yannick; Février, Laureline; Marmier, Nicolas; Achouak, Wafa; Nardoux, Pascal; Berthomieu, Catherine; Chapon, Virginie

2011-01-01

This study investigated the influence of uranium on the indigenous bacterial community structure in natural soils with high uranium content. Radioactive soil samples exhibiting 0.26% - 25.5% U in mass were analyzed and compared with nearby control soils containing trace uranium. EXAFS and XRD analyses of soils revealed the presence of U(VI) and uranium-phosphate mineral phases, identified as sabugalite and meta-autunite. A comparative analysis of bacterial community fingerprints using denaturing gradient gel electrophoresis (DGGE) revealed the presence of a complex population in both control and uranium-rich samples. However, bacterial communities inhabiting uraniferous soils exhibited specific fingerprints that were remarkably stable over time, in contrast to populations from nearby control samples. Representatives of Acidobacteria, Proteobacteria, and seven others phyla were detected in DGGE bands specific to uraniferous samples. In particular, sequences related to iron-reducing bacteria such as Geobacter and Geothrix were identified concomitantly with iron-oxidizing species such as Gallionella and Sideroxydans. All together, our results demonstrate that uranium exerts a permanent high pressure on soil bacterial communities and suggest the existence of a uranium redox cycle mediated by bacteria in the soil. PMID:21998695

rTES-30USM: cloning via assembly PCR, expression, and evaluation of usefulness in the detection of toxocariasis.

PubMed

Norhaida, A; Suharni, M; Liza Sharmini, A T; Tuda, J; Rahmah, N

2008-03-01

Currently, the laboratory diagnosis of toxocariasis, caused by Toxocara canis or T. cati, mainly relies on serological tests. Unfortunately, however, the specificities of most of the commercial tests that are available for the serodiagnosis of this disease are not very high and this may cause problems, especially in tropical countries where co-infections with other helminths are common. In an effort to develop a serological assay with improved specificity for the detection of Toxocara infection, an IgG(4)-ELISA based on a recombinant version (rTES-30USM) of the 30-kDa Toxocara excretory-secretory antigen (TES-30) has recently been developed. To produce the antigen, the TES-30 gene was cloned via assembly PCR, subcloned into a His-tagged prokaryotic expression vector, and purified by affinity chromatography using Ni(2+)-nitrilotriacetic-acid (Ni-NTA) resin. The performance of the ELISA based on the recombinant antigen was then compared with that of commercial kit, based on an IgG-ELISA, for the serodiagnosis of toxocariasis (Toxocara IgG-ELISA; Cypress Diagnostics, Langdorp, Belgium). Both assays were used to test 338 serum samples, including 26 samples from probable cases of toxocariasis. Assuming that all the probable cases were true cases, the assay based on rTES-30USM demonstrated a sensitivity of 92.3% (24/26) and a specificity of 89.6% (103/115) whereas the commercial kit exhibited a sensitivity of 100% (26/26) but a specificity of only 55.7% (64/115). The high sensitivity and specificity exhibited by the new IgG(4)-ELISA should make the assay a good choice for use in tropical countries and any other area where potentially cross-reactive helminthic infections are common.

Nanoarchitectured Nb2O5 hollow, Nb2O5@carbon and NbO2@carbon Core-Shell Microspheres for Ultrahigh-Rate Intercalation Pseudocapacitors

NASA Astrophysics Data System (ADS)

Kong, Lingping; Zhang, Chuanfang; Wang, Jitong; Qiao, Wenming; Ling, Licheng; Long, Donghui

2016-02-01

Li-ion intercalation materials with extremely high rate capability will blur the distinction between batteries and supercapacitors. We construct a series of nanoarchitectured intercalation materials including orthorhombic (o-) Nb2O5 hollow microspheres, o-Nb2O5@carbon core-shell microspheres and tetragonal (t-) NbO2@carbon core-shell microspheres, through a one-pot hydrothermal method with different post-treatments. These nanoarchitectured materials consist of small nanocrystals with highly exposed active surface, and all of them demonstrate good Li+ intercalation pseudocapacitive properties. In particular, o-Nb2O5 hollow microspheres can deliver the specific capacitance of 488.3 F g-1, and good rate performance of 126.7 F g-1 at 50 A g-1. The o-Nb2O5@carbon core-shell microspheres show enhanced specific capacitance of 502.2 F g-1 and much improved rate performance (213.4 F g-1 at 50 A g-1). Furthermore, we demonstrate for the first time, t-NbO2 exhibits much higher rate capability than o-Nb2O5. For discharging time as fast as 5.9 s (50 A g-1), it still exhibits a very high specific capacitance of 245.8 F g-1, which is 65.2% retention of the initial capacitance (377.0 F g-1 at 1 A g-1). The unprecedented rate capability is an intrinsic feature of t-NbO2, which may be due to the conductive lithiated compounds.

Nanoarchitectured Nb2O5 hollow, Nb2O5@carbon and NbO2@carbon Core-Shell Microspheres for Ultrahigh-Rate Intercalation Pseudocapacitors

PubMed Central

Kong, Lingping; Zhang, Chuanfang; Wang, Jitong; Qiao, Wenming; Ling, Licheng; Long, Donghui

2016-01-01

Li-ion intercalation materials with extremely high rate capability will blur the distinction between batteries and supercapacitors. We construct a series of nanoarchitectured intercalation materials including orthorhombic (o-) Nb2O5 hollow microspheres, o-Nb2O5@carbon core-shell microspheres and tetragonal (t-) NbO2@carbon core-shell microspheres, through a one-pot hydrothermal method with different post-treatments. These nanoarchitectured materials consist of small nanocrystals with highly exposed active surface, and all of them demonstrate good Li+ intercalation pseudocapacitive properties. In particular, o-Nb2O5 hollow microspheres can deliver the specific capacitance of 488.3 F g−1, and good rate performance of 126.7 F g−1 at 50 A g−1. The o-Nb2O5@carbon core-shell microspheres show enhanced specific capacitance of 502.2 F g−1 and much improved rate performance (213.4 F g−1 at 50 A g−1). Furthermore, we demonstrate for the first time, t-NbO2 exhibits much higher rate capability than o-Nb2O5. For discharging time as fast as 5.9 s (50 A g−1), it still exhibits a very high specific capacitance of 245.8 F g−1, which is 65.2% retention of the initial capacitance (377.0 F g−1 at 1 A g−1). The unprecedented rate capability is an intrinsic feature of t-NbO2, which may be due to the conductive lithiated compounds. PMID:26880276

Tuning the porosity of mesoporous NiO through calcining isostructural Ni-MOFs toward supercapacitor applications

NASA Astrophysics Data System (ADS)

Hou, Xiang-Yang; Yan, Xiao-Li; Wang, Xiao; Zhai, Quan-Guo

2018-07-01

NiO has an unusually high theoretical specific capacitance and possess relatively high electrical conductivity compared to other metal oxides. However, the reported specific capacitance of the NiO-based electrodes is far below the theoretical value up to now. In this paper, three porous NiO materials with different specific surface area were synthesized simply by calcining iso-structural Ni-based MOFs templates. The formation mechanism of NiO was discussed by taking into account the thermal behavior and intrinsic structural features of the Ni-MOFs. Taking advantages of the Ni-MOFs precursors, all prepared NiO compounds are mesoporous and their porosity can be tuned by the structure of MOFs. Specially, due to the high porosity, three NiO exhibited an improved electrochemical performance and the specific discharge capacitances are of 102, 105, and 116 F g-1 at the current density of 1 A g-1, respectively. The specific capacitance of 1-NiO-450 is approximately 93.2% of its maximum value after 3000 cycles, which obviously superior to most of the previously reported NiO electrode materials and suggests their promising applications in supercapacitors.

A High Throughput Protein Microarray Approach to Classify HIV Monoclonal Antibodies and Variant Antigens

PubMed Central

Dotsey, Emmanuel Y.; Gorlani, Andrea; Ingale, Sampat; Achenbach, Chad J.; Forthal, Donald N.; Felgner, Philip L.; Gach, Johannes S.

2015-01-01

In recent years, high throughput discovery of human recombinant monoclonal antibodies (mAbs) has been applied to greatly advance our understanding of the specificity, and functional activity of antibodies against HIV. Thousands of antibodies have been generated and screened in functional neutralization assays, and antibodies associated with cross-strain neutralization and passive protection in primates, have been identified. To facilitate this type of discovery, a high throughput-screening tool is needed to accurately classify mAbs, and their antigen targets. In this study, we analyzed and evaluated a prototype microarray chip comprised of the HIV-1 recombinant proteins gp140, gp120, gp41, and several membrane proximal external region peptides. The protein microarray analysis of 11 HIV-1 envelope-specific mAbs revealed diverse binding affinities and specificities across clades. Half maximal effective concentrations, generated by our chip analysis, correlated significantly (P<0.0001) with concentrations from ELISA binding measurements. Polyclonal immune responses in plasma samples from HIV-1 infected subjects exhibited different binding patterns, and reactivity against printed proteins. Examining the totality of the specificity of the humoral response in this way reveals the exquisite diversity, and specificity of the humoral response to HIV. PMID:25938510

Three-dimensional cotton-like nickel nanowire@Ni-Co hydroxide nanosheet arrays as binder-free electrode for high-performance asymmetric supercapacitor

NASA Astrophysics Data System (ADS)

Wan, Houzhao; Li, Lang; Xu, Yang; Tan, Qiuyang; Liu, Xiang; Zhang, Jun; Wang, Hanbin; Wang, Hao

2018-05-01

Three-dimensional (3D) cotton-like Ni-Co layered double hydroxide nanosheet arrays/nickel nanowires (3D Ni-Co LDH/NiNw) were successfully fabricated through a facile chemical bath deposition method. The 3D nickel nanowires are used as a conductive substrate with robust adhesion for high-pseudocapacitance Ni-Co LDH. The 3D Ni-Co LDH/NiNw electrode shows a high areal specific capacitance of 14 F cm-2 at 5 mA cm-2 and quality specific capacitance of 466.6 F g-1 at 0.125 A g-1 with respect to the whole quality of the electrode. The fabricated asymmetric supercapacitor exhibits a remarkable energy density of 0.387 mWh cm-2 using Ni-Co LDH/NiNw as the negative electrode. This high-performance composite electrode presents a new and affordable general approach for supercapacitors.

Nitrogen and phosphorus co-doped carbon hollow spheres derived from polypyrrole for high-performance supercapacitor electrodes

NASA Astrophysics Data System (ADS)

Lv, Bingjie; Li, Peipei; Liu, Yan; Lin, Shanshan; Gao, Bifen; Lin, Bizhou

2018-04-01

Nitrogen and phosphorus co-doped carbon hollow spheres (NPCHSs) have been prepared by a carbonization and subsequent chemical activation route using dehydrated polypyrrole hollow spheres as the precursor and KOH as the activating agent. NPCHSs are interconnected into a unique 3D porous network, which endows the as-prepared carbon to exhibit a large specific surface area of 1155 m2 g-1 and a high specific capacitance of 232 F g-1 at a current density of 1 A g-1. The as-obtained NPCHSs present a high-level heteroatom doping with N, O and P contents of 11.4, 6.7 and 3.5 wt%, respectively. The capacitance of NPCHSs has been retained at 89.1% after 5000 charge-discharge cycles at a relatively high current density of 5 A g-1. Such excellent performance suggests that NPCHSs are attractive electrode candidates for electrical double layer capacitors.

Three-dimensional cotton-like nickel nanowire@Ni-Co hydroxide nanosheet arrays as binder-free electrode for high-performance asymmetric supercapacitor.

PubMed

Wan, Houzhao; Li, Lang; Xu, Yang; Tan, Qiuyang; Liu, Xiang; Zhang, Jun; Wang, Hanbin; Wang, Hao

2018-05-11

Three-dimensional (3D) cotton-like Ni-Co layered double hydroxide nanosheet arrays/nickel nanowires (3D Ni-Co LDH/NiNw) were successfully fabricated through a facile chemical bath deposition method. The 3D nickel nanowires are used as a conductive substrate with robust adhesion for high-pseudocapacitance Ni-Co LDH. The 3D Ni-Co LDH/NiNw electrode shows a high areal specific capacitance of 14 F cm -2 at 5 mA cm -2 and quality specific capacitance of 466.6 F g -1 at 0.125 A g -1 with respect to the whole quality of the electrode. The fabricated asymmetric supercapacitor exhibits a remarkable energy density of 0.387 mWh cm -2 using Ni-Co LDH/NiNw as the negative electrode. This high-performance composite electrode presents a new and affordable general approach for supercapacitors.

Iodine doped carbon nanotube cables exceeding specific electrical conductivity of metals

PubMed Central

Zhao, Yao; Wei, Jinquan; Vajtai, Robert; Ajayan, Pulickel M.; Barrera, Enrique V.

2011-01-01

Creating highly electrically conducting cables from macroscopic aggregates of carbon nanotubes, to replace metallic wires, is still a dream. Here we report the fabrication of iodine-doped, double-walled nanotube cables having electrical resistivity reaching ∼10−7 Ω.m. Due to the low density, their specific conductivity (conductivity/weight) is higher than copper and aluminum and is only just below that of the highest specific conductivity metal, sodium. The cables exhibit high current-carrying capacity of 104∼105 A/cm2 and can be joined together into arbitrary length and diameter, without degradation of their electrical properties. The application of such nanotube cables is demonstrated by partly replacing metal wires in a household light bulb circuit. The conductivity variation as a function of temperature for the cables is five times smaller than that for copper. The high conductivity nanotube cables could find a range of applications, from low dimensional interconnects to transmission lines. PMID:22355602

Prostate-Specific G-Protein Coupled Receptor, an Emerging Biomarker Regulating Inflammation and Prostate Cancer Invasion.

PubMed

Rodriguez, M; Siwko, S; Liu, M

2016-01-01

Prostate cancer is highly prevalent among men in developed countries, but a significant proportion of detected cancers remain indolent, never progressing into aggressive carcinomas. This highlights the need to develop refined biomarkers that can distinguish between indolent and potentially dangerous cases. The prostate-specific G-protein coupled receptor (PSGR, or OR51E2) is an olfactory receptor family member with highly specific expression in human prostate epithelium that is highly overexpressed in PIN and prostate cancer. PSGR has been functionally implicated in prostate cancer cell invasiveness, suggesting a potential role in the transition to metastatic PCa. Recently, transgenic mice overexpressing PSGR in the prostate were reported to develop an acute inflammatory response followed by emergence of low grade PIN, whereas mice with compound PSGR overexpression and loss of PTEN exhibited accelerated formation of invasive prostate adenocarcinoma. This article will review recent PSGR findings with a focus on its role as a potential prostate cancer biomarker and regulator of prostate cancer invasion and inflammation.

Retest reliability of individual alpha ERD topography assessed by human electroencephalography.

PubMed

Vázquez-Marrufo, Manuel; Galvao-Carmona, Alejandro; Benítez Lugo, María Luisa; Ruíz-Peña, Juan Luis; Borges Guerra, Mónica; Izquierdo Ayuso, Guillermo

2017-01-01

Despite the immense literature related to diverse human electroencephalographic (EEG) parameters, very few studies have focused on the reliability of these measures. Some of the most studied components (i.e., P3 or MMN) have received more attention regarding the stability of their main parameters, such as latency, amplitude or topography. However, spectral modulations have not been as extensively evaluated considering that different analysis methods are available. The main aim of the present study is to assess the reliability of the latency, amplitude and topography of event-related desynchronization (ERD) for the alpha band (10-14 Hz) observed in a cognitive task (visual oddball). Topography reliability was analysed at different levels (for the group, within-subjects individually and between-subjects individually). The latency for alpha ERD showed stable behaviour between two sessions, and the amplitude exhibited an increment (more negative) in the second session. Alpha ERD topography exhibited a high correlation score between sessions at the group level (r = 0.903, p<0.001). The mean value for within-subject correlations was 0.750 (with a range from 0.391 to 0.954). Regarding between-subject topography comparisons, some subjects showed a highly specific topography, whereas other subjects showed topographies that were more similar to those of other subjects. ERD was mainly stable between the two sessions with the exception of amplitude, which exhibited an increment in the second session. Topography exhibits excellent reliability at the group level; however, it exhibits highly heterogeneous behaviour at the individual level. Considering that the P3 was previously evaluated for this group of subjects, a direct comparison of the correlation scores was possible, and it showed that the ERD component is less reliable in individual topography than in the ERP component (P3).

Retest reliability of individual alpha ERD topography assessed by human electroencephalography

PubMed Central

Vázquez-Marrufo, Manuel; Benítez Lugo, María Luisa; Ruíz-Peña, Juan Luis; Borges Guerra, Mónica; Izquierdo Ayuso, Guillermo

2017-01-01

Background Despite the immense literature related to diverse human electroencephalographic (EEG) parameters, very few studies have focused on the reliability of these measures. Some of the most studied components (i.e., P3 or MMN) have received more attention regarding the stability of their main parameters, such as latency, amplitude or topography. However, spectral modulations have not been as extensively evaluated considering that different analysis methods are available. The main aim of the present study is to assess the reliability of the latency, amplitude and topography of event-related desynchronization (ERD) for the alpha band (10–14 Hz) observed in a cognitive task (visual oddball). Topography reliability was analysed at different levels (for the group, within-subjects individually and between-subjects individually). Results The latency for alpha ERD showed stable behaviour between two sessions, and the amplitude exhibited an increment (more negative) in the second session. Alpha ERD topography exhibited a high correlation score between sessions at the group level (r = 0.903, p<0.001). The mean value for within-subject correlations was 0.750 (with a range from 0.391 to 0.954). Regarding between-subject topography comparisons, some subjects showed a highly specific topography, whereas other subjects showed topographies that were more similar to those of other subjects. Conclusion ERD was mainly stable between the two sessions with the exception of amplitude, which exhibited an increment in the second session. Topography exhibits excellent reliability at the group level; however, it exhibits highly heterogeneous behaviour at the individual level. Considering that the P3 was previously evaluated for this group of subjects, a direct comparison of the correlation scores was possible, and it showed that the ERD component is less reliable in individual topography than in the ERP component (P3). PMID:29088307

Microbial eukaryote plankton communities of high-mountain lakes from three continents exhibit strong biogeographic patterns.

PubMed

Filker, Sabine; Sommaruga, Ruben; Vila, Irma; Stoeck, Thorsten

2016-05-01

Microbial eukaryotes hold a key role in aquatic ecosystem functioning. Yet, their diversity in freshwater lakes, particularly in high-mountain lakes, is relatively unknown compared with the marine environment. Low nutrient availability, low water temperature and high ultraviolet radiation make most high-mountain lakes extremely challenging habitats for life and require specific molecular and physiological adaptations. We therefore expected that these ecosystems support a plankton diversity that differs notably from other freshwater lakes. In addition, we hypothesized that the communities under study exhibit geographic structuring. Our rationale was that geographic dispersal of small-sized eukaryotes in high-mountain lakes over continental distances seems difficult. We analysed hypervariable V4 fragments of the SSU rRNA gene to compare the genetic microbial eukaryote diversity in high-mountain lakes located in the European Alps, the Chilean Altiplano and the Ethiopian Bale Mountains. Microbial eukaryotes were not globally distributed corroborating patterns found for bacteria, multicellular animals and plants. Instead, the plankton community composition emerged as a highly specific fingerprint of a geographic region even on higher taxonomic levels. The intraregional heterogeneity of the investigated lakes was mirrored in shifts in microbial eukaryote community structure, which, however, was much less pronounced compared with interregional beta-diversity. Statistical analyses revealed that on a regional scale, environmental factors are strong predictors for plankton community structures in high-mountain lakes. While on long-distance scales (>10 000 km), isolation by distance is the most plausible scenario, on intermediate scales (up to 6000 km), both contemporary environmental factors and historical contingencies interact to shift plankton community structures. © 2016 John Wiley & Sons Ltd.

Versatile NiO/mesoporous carbon nanodisks: controlled synthesis from hexagon shaped heterobimetallic metal-organic frameworks.

PubMed

Zeng, Dehong; Yang, Ying; Yang, Feng; Guo, Fangmin; Yang, Senjie; Liu, Baijun; Hao, Shijie; Ren, Yang

2017-08-24

Hexagonal NiO/mesoporous carbon nanodisks (NiO/MCN) are facilely and controllably synthesized via constructing nickel-zinc trimesic acid heterobimetallic metal-organic framework (HMOF) disks before pyrolysis at 910 °C. Tailoring the Ni/(Zn + Ni) feed ratio and the reaction time during the HMOF synthesis creates a well-defined hexagonal carbon nanodisk with properly populated NiO nanocrystals while maintaining high porosity and conductivity. Such an elaborately fabricated NiO/MCN is highly stable, and exhibits the largest specific capacitance of 261 F g -1 and the highest specific activity factor of 1.93 s -1 g -1 of any composite nanodisk during the capacitive test and 4-nitrophenol reduction, respectively.

Design concepts of high power bipolar rechargeable lithium battery

NASA Technical Reports Server (NTRS)

Shen, David H.; Halpert, Gerald

1993-01-01

The present study shows that current bipolar Li/TiS2 batteries using a 0.38 mm thick TiS2 bipolar plate can yield moderate specific power and also high specific energy battery. The computer design studies project that a 100 V, 10 A h bipolar Li/TiS2 battery can achieve 150 W h/kg, 210 W h/l, and 150 W/kg. The unoptimized experimental bipolar Li/TiS2 batteries (3 cells, 90 mA h) exhibited 47 W h/kg, 90 W h/l, and 140 W/kg. Preliminary results on the cycleability of the bipolar batteries are demonstrated. The results also show that enhanced rate capability can be achieved by using pulse discharge and longer rest period between pulses.

Synthesis of Porous Carbon Monoliths Using Hard Templates.

PubMed

Klepel, Olaf; Danneberg, Nina; Dräger, Matti; Erlitz, Marcel; Taubert, Michael

2016-03-21

The preparation of porous carbon monoliths with a defined shape via template-assisted routes is reported. Monoliths made from porous concrete and zeolite were each used as the template. The porous concrete-derived carbon monoliths exhibited high gravimetric specific surface areas up to 2000 m²·g -1 . The pore system comprised macro-, meso-, and micropores. These pores were hierarchically arranged. The pore system was created by the complex interplay of the actions of both the template and the activating agent as well. On the other hand, zeolite-made template shapes allowed for the preparation of microporous carbon monoliths with a high volumetric specific surface area. This feature could be beneficial if carbon monoliths must be integrated into technical systems under space-limited conditions.

Synthesis of Porous Carbon Monoliths Using Hard Templates

PubMed Central

Klepel, Olaf; Danneberg, Nina; Dräger, Matti; Erlitz, Marcel; Taubert, Michael

2016-01-01

The preparation of porous carbon monoliths with a defined shape via template-assisted routes is reported. Monoliths made from porous concrete and zeolite were each used as the template. The porous concrete-derived carbon monoliths exhibited high gravimetric specific surface areas up to 2000 m2·g−1. The pore system comprised macro-, meso-, and micropores. These pores were hierarchically arranged. The pore system was created by the complex interplay of the actions of both the template and the activating agent as well. On the other hand, zeolite-made template shapes allowed for the preparation of microporous carbon monoliths with a high volumetric specific surface area. This feature could be beneficial if carbon monoliths must be integrated into technical systems under space-limited conditions. PMID:28773338

Hoarders Only Discount Consumables and Are More Patient for Money

PubMed Central

Vickers, Brian D.; Preston, Stephanie D.; Gonzalez, Richard; Angott, Andrea M.

2016-01-01

Individuals with hoarding disorder (HD) excessively acquire and retain goods while also exhibiting characteristics of impulsivity and addiction. However, HD individuals do not always perform impulsively in experiments, they do not appear interested in money, and they exhibit many features of risk-aversion and future-planning. To examine impulsivity in HD, we compared validated community participants high and low in hoarding tendencies on questionnaire measures of hoarding and impulsivity as well as a standard experimental measure of impulsivity (intertemporal discounting) that was modified to compare decisions about money, pens, and snacks. Common discounting effects were replicated. Compared to the low hoarding group, the high hoarding group was more impatient for consumables (pens and snacks) but they were more patient for money. This increased patience for money in high hoarding individuals is in contrast to all other studies on discounting in disordered populations, but consistent with the phenomenology of HD. HD does not appear to be driven by a fundamental inability to wait, but rather a specific, potent desire for consumable rewards. PMID:26973479

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

Tan, Guoqiang; Wu, Feng; Zhan, Chun

The development of safe, stable, and long-life Li-ion batteries is being intensively pursued to enable the electrification of transportation and intelligent grid applications. Here, we report a new solid-state Li-ion battery technology, using a solid nanocomposite electrolyte composed of porous silica matrices with in situ immobilizing Li+ conducting ionic liquid, anode material of MCMB, and cathode material of LiCoO 2, LiNi 1/3Co 1/3Mn 1/3O 2, or LiFePO 4. An injection printing method is used for the electrode/electrolyte preparation. Solid nanocomposite electrolytes exhibit superior performance to the conventional organic electrolytes with regard to safety and cycle-life. They also have a transparentmore » glassy structure with high ionic conductivity and good mechanical strength. Solid-state full cells tested with the various cathodes exhibited high specific capacities, long cycling stability, and excellent high temperature performance. This solid-state battery technology will provide new avenues for the rational engineering of advanced Li-ion batteries and other electrochemical devices.« less

Hoarders Only Discount Consumables and Are More Patient for Money.

PubMed

Vickers, Brian D; Preston, Stephanie D; Gonzalez, Richard; Angott, Andrea M

2016-01-01

Individuals with hoarding disorder (HD) excessively acquire and retain goods while also exhibiting characteristics of impulsivity and addiction. However, HD individuals do not always perform impulsively in experiments, they do not appear interested in money, and they exhibit many features of risk-aversion and future-planning. To examine impulsivity in HD, we compared validated community participants high and low in hoarding tendencies on questionnaire measures of hoarding and impulsivity as well as a standard experimental measure of impulsivity (intertemporal discounting) that was modified to compare decisions about money, pens, and snacks. Common discounting effects were replicated. Compared to the low hoarding group, the high hoarding group was more impatient for consumables (pens and snacks) but they were more patient for money. This increased patience for money in high hoarding individuals is in contrast to all other studies on discounting in disordered populations, but consistent with the phenomenology of HD. HD does not appear to be driven by a fundamental inability to wait, but rather a specific, potent desire for consumable rewards.

Highly stable and self-repairing membrane-mimetic 2D nanomaterials assembled from lipid-like peptoids

PubMed Central

Jin, Haibao; Jiao, Fang; Daily, Michael D.; Chen, Yulin; Yan, Feng; Ding, Yan-Huai; Zhang, Xin; Robertson, Ellen J.; Baer, Marcel D.; Chen, Chun-Long

2016-01-01

An ability to develop sequence-defined synthetic polymers that both mimic lipid amphiphilicity for self-assembly of highly stable membrane-mimetic 2D nanomaterials and exhibit protein-like functionality would revolutionize the development of biomimetic membranes. Here we report the assembly of lipid-like peptoids into highly stable, crystalline, free-standing and self-repairing membrane-mimetic 2D nanomaterials through a facile crystallization process. Both experimental and molecular dynamics simulation results show that peptoids assemble into membranes through an anisotropic formation process. We further demonstrated the use of peptoid membranes as a robust platform to incorporate and pattern functional objects through large side-chain diversity and/or co-crystallization approaches. Similar to lipid membranes, peptoid membranes exhibit changes in thickness upon exposure to external stimuli; they can coat surfaces in single layers and self-repair. We anticipate that this new class of membrane-mimetic 2D nanomaterials will provide a robust matrix for development of biomimetic membranes tailored to specific applications. PMID:27402325

Surface design and engineering of hierarchical hybrid nanostructures for asymmetric supercapacitors with improved electrochemical performance.

PubMed

Achilleos, Demetra S; Hatton, T Alan

2015-06-01

With the current rising world demand for energy sufficiency, there is an increased necessity for the development of efficient energy storage devices. To address these needs, the scientific community has focused on the improvement of the electrochemical properties of the most well known energy storage devices; the Li-ion batteries and electrochemical capacitors, also called supercapacitors. Despite the fact that supercapacitors exhibit high power densities, good reversibility and long cycle life, they still exhibit lower energy densities than batteries, which limit their practical application. Various strategies have been employed to circumvent this problem, specifically targetting an increase in the specific capacitance and the broadening of the potential window of operation of these systems. In recent years, sophisticated surface design and engineering of hierarchical hybrid nanostructures has facilitated significant improvements in the specific and volumetric storage capabilities of supercapacitors. These nanostructured electrodes exhibit higher surface areas for ion adsorption and reduced ion diffusion lengths for the electrolyte ions. Significant advances have also been achieved in broadening the electrochemical window of operation of these systems, as realized via the development of asymmetric two-electrode cells consisting of nanocomposite positive and negative electrodes with complementary electrochemical windows, which operate in environmentally benign aqueous media. We provide an overview of the diverse approaches, in terms of chemistry and nanoscale architecture, employed recently for the development of asymmetric supercapacitors of improved electrochemical performance. Copyright © 2014 Elsevier Inc. All rights reserved.

Facile synthesis of titanium (IV) ion immobilized adenosine triphosphate functionalized silica nanoparticles for highly specific enrichment and analysis of intact phosphoproteins.

PubMed

Wang, Hao; Tian, Zhixin

2018-06-06

Analysis of phosphoproteins always faces the challenge of low stoichiometry, which demands highly selective and efficient enrichment in the initial sample preparation. Here we report our synthesis of the novel titanium (IV) ion immobilized adenosine triphosphate functionalized silica nanoparticles (Ti 4+ -ATP-NPs) for efficient enrichment of intact phosphoproteins. The average diameter of Ti 4+ -ATP-NPs was about 128 nm with good dispersibility and the saturated adsorption capacity for β-casein was 1046.5 mg/g. In addition, Ti 4+ -ATP-NPs exhibited high specificity and selectivity in enriching phosphoproteins from both standard protein mixtures and complex biological samples (non-fat milk, chicken egg white and mouse heart tissue extract) as demonstrated by SDS-PAGE. Copyright © 2018 Elsevier B.V. All rights reserved.

Preparation and Characterization of Cyclotrimethylenetrinitramine (RDX) with Reduced Sensitivity

PubMed Central

Wang, Yuqiao; Li, Xin; Chen, Shusen; Ma, Xiao; Yu, Ziyang; Jin, Shaohua; Li, Lijie; Chen, Yu

2017-01-01

The internal defects and shape of cyclotrimethylenetrinitramine (RDX) crystal are critical parameters for the preparation of reduced sensitivity RDX (RS-RDX). In the current study, RDX was re-crystallized and spheroidized to form the high-quality RDX that was further characterized by purity, apparent density, size distribution, specific surface area, impact sensitivity, and shock sensitivity. The effects of re-crystallization solvent on the growth morphology of RDX crystal were investigated by both theoretical simulation and experiment test, and consistent results were obtained. The high-quality RDX exhibited a high purity (≥99.90%), high apparent density (≥1.811 g/cm3), spherical shape, and relatively low impact sensitivity (6%). Its specific surface area was reduced more than 30%. Compared with conventional RDXs, the high-quality RDX reduced the shock sensitivities of PBXN-109 and PBXW-115 by more than 30%, indicating that it was a RS-RDX. The reduced sensitivity and good processability of the high-quality RDX would be significant in improving the performances of RDX-based PBXs. PMID:28825661

ZBTB20 is required for anterior pituitary development and lactotrope specification.

PubMed

Cao, Dongmei; Ma, Xianhua; Cai, Jiao; Luan, Jing; Liu, An-Jun; Yang, Rui; Cao, Yi; Zhu, Xiaotong; Zhang, Hai; Chen, Yu-Xia; Shi, Yuguang; Shi, Guang-Xia; Zou, Dajin; Cao, Xuetao; Grusby, Michael J; Xie, Zhifang; Zhang, Weiping J

2016-04-15

The anterior pituitary harbours five distinct hormone-producing cell types, and their cellular differentiation is a highly regulated and coordinated process. Here we show that ZBTB20 is essential for anterior pituitary development and lactotrope specification in mice. In anterior pituitary, ZBTB20 is highly expressed by all the mature endocrine cell types, and to some less extent by somatolactotropes, the precursors of prolactin (PRL)-producing lactotropes. Disruption of Zbtb20 leads to anterior pituitary hypoplasia, hypopituitary dwarfism and a complete loss of mature lactotropes. In ZBTB20-null mice, although lactotrope lineage commitment is normally initiated, somatolactotropes exhibit profound defects in lineage specification and expansion. Furthermore, endogenous ZBTB20 protein binds to Prl promoter, and its knockdown decreases PRL expression and secretion in a lactotrope cell line MMQ. In addition, ZBTB20 overexpression enhances the transcriptional activity of Prl promoter in vitro. In conclusion, our findings point to ZBTB20 as a critical regulator of anterior pituitary development and lactotrope specification.

ZBTB20 is required for anterior pituitary development and lactotrope specification

PubMed Central

Cao, Dongmei; Ma, Xianhua; Cai, Jiao; Luan, Jing; Liu, An-Jun; Yang, Rui; Cao, Yi; Zhu, Xiaotong; Zhang, Hai; Chen, Yu-Xia; Shi, Yuguang; Shi, Guang-Xia; Zou, Dajin; Cao, Xuetao; Grusby, Michael J.; Xie, Zhifang; Zhang, Weiping J.

2016-01-01

The anterior pituitary harbours five distinct hormone-producing cell types, and their cellular differentiation is a highly regulated and coordinated process. Here we show that ZBTB20 is essential for anterior pituitary development and lactotrope specification in mice. In anterior pituitary, ZBTB20 is highly expressed by all the mature endocrine cell types, and to some less extent by somatolactotropes, the precursors of prolactin (PRL)-producing lactotropes. Disruption of Zbtb20 leads to anterior pituitary hypoplasia, hypopituitary dwarfism and a complete loss of mature lactotropes. In ZBTB20-null mice, although lactotrope lineage commitment is normally initiated, somatolactotropes exhibit profound defects in lineage specification and expansion. Furthermore, endogenous ZBTB20 protein binds to Prl promoter, and its knockdown decreases PRL expression and secretion in a lactotrope cell line MMQ. In addition, ZBTB20 overexpression enhances the transcriptional activity of Prl promoter in vitro. In conclusion, our findings point to ZBTB20 as a critical regulator of anterior pituitary development and lactotrope specification. PMID:27079169

Scalable and sustainable synthesis of carbon microspheres via a purification-free strategy for sodium-ion capacitors

NASA Astrophysics Data System (ADS)

Wang, Shijie; Wang, Rutao; Zhang, Yabin; Jin, Dongdong; Zhang, Li

2018-03-01

Sodium-based energy storage receives a great deal of interest due to the virtually inexhaustible sodium reserve, while the scalable and sustainable strategies to synthesize carbon-based materials with suitable interlayer spaces and large sodium storage capacities are yet to be fully investigated. Carbon microspheres, with regular geometry, non-graphitic characteristic, and stable nature are promising candidates, yet the synthetic methods are usually complex and energy consuming. In this regard, we report a scalable purification-free strategy to synthesize carbon microspheres directly from 5 species of fresh juice. As-synthesized carbon microspheres exhibit dilated interlayer distance of 0.375 nm and facilitate Na+ uptake and release. For example, such carbon microsphere anodes have a specific capacity of 183.9 mAh g-1 at 50 mA g-1 and exhibit ultra-stability (99.0% capacity retention) after 10000 cycles. Moreover, via facile activation, highly porous carbon microsphere cathodes are fabricated and show much higher energy density at high rate than commercial activated carbon. Coupling the compelling anodes and cathodes above, novel sodium-ion capacitors show the high working potential up to 4.0 V, deliver a maximum energy density of 52.2 Wh kg-1, and exhibit an acceptable capacity retention of 85.7% after 2000 cycles.

3D flower-like hierarchical Ag@nickel-cobalt hydroxide microsphere with enhanced electrochemical properties

NASA Astrophysics Data System (ADS)

Lv, Zijian; Zhong, Qin; Bu, Yunfei; Wu, Junpeng

2016-10-01

The morphology and electrical conductivity are essential to electrochemical performance of electrode materials in renewable energy conversion and storage technologies such as fuel cells and supercapacitors. Here, we explored a facile method to grow Ag@nickel-cobalt layered double hydroxide (Ag@Ni/Co-LDHs) with 3D flower-like microsphere structure. The results show the morphology of Ni/Co-LDHs varies with the introduction of Ag species. The prepared Ag@Ni/Co-LDHs not only exhibits an open hierarchical structure with high specific capacitance but also shows good electrical conductivity to support fast electron transport. Benefiting from the unique structural features, these flower-like Ag@Ni/Co-LDHs microspheres have impressive specific capacitance as high as 1768 F g-1 at 1 A g-1. It can be concluded that engineering the structure of the electrode can increase the efficiency of the specific capacitance as a battery-type electrode for hybrid supercapacitors.

MOF-Bacteriophage Biosensor for Highly Sensitive and Specific Detection of Staphylococcus aureus.

PubMed

Bhardwaj, Neha; Bhardwaj, Sanjeev K; Mehta, Jyotsana; Kim, Ki-Hyun; Deep, Akash

2017-10-04

To produce a sensitive and specific biosensor for Staphylococcus aureus, bacteriophages have been interfaced with a water-dispersible and environmentally stable metal-organic framework (MOF), NH 2 -MIL-53(Fe). The conjugation of the MOF with bacteriophages has been achieved through the use of glutaraldehyde as cross-linker. Highly sensitive detection of S. aureus in both synthetic and real samples was realized by the proposed MOF-bacteriophage biosensor based on the photoluminescence quenching phenomena: limit of detection (31 CFU/mL) and range of detection (40 to 4 × 10 8 CFU/mL). This is the first report exploiting the use of an MOF-bacteriophage complex for the biosensing of S. aureus. The results of our study highlight that the proposed biosensor is more sensitive than most of the previous methods while exhibiting some advanced features like specificity, regenerability, extended range of linear detection, and stability for long-term storage (even at room temperature).

Synergistically Active NiCo2 S4 Nanoparticles Coupled with Holey Defect Graphene Hydrogel for High-Performance Solid-State Supercapacitors.

PubMed

Tiruneh, Sintayehu Nibret; Kang, Bong Kyun; Kwag, Sung Hoon; Lee, YoungHun; Kim, MinSeob; Yoon, Dae Ho

2018-03-02

Nickel cobalt sulfide nanoparticles embedded in holey defect graphene hydrogel (HGH) that exhibit highly porous structures and uniform nickel cobalt sulfide nanoparticle sizes are successfully prepared by a facile solvothermal-hydrothermal method. As an electrode material for supercapacitors, the as-prepared NiCo 2 S 4 @HGH shows ultra-high specific capacitances of 1000 F g -1 and 800 F g -1 at 0.5 and 6 A g -1 , respectively, owing to the outstanding electrical conductivity of HGH and high specific capacitance of NiCo 2 S 4 . After 2100 charge/discharge cycles at a current density of 6 A g -1 , 96.6 % of the specific capacitance was retained, signifying the superb durability of NiCo 2 S 4 @HGH. Moreover, remarkable specific capacitance (312.6 F g -1 ) and capacity retention (87 % after 5000 cycles) at 6 A g -1 were displayed by the symmetric solid-state supercapacitor fabricated by using NiCo 2 S 4 @HGH electrodes. These auspicious supercapacitor performances demonstrate that the as-developed solvothermal-hydrothermal approach can be widely used to prepare graphene-coupled binary metal sulfides for high-performance supercapacitor applications. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Supercapacitors based on self-assembled graphene organogel.

PubMed

Sun, Yiqing; Wu, Qiong; Shi, Gaoquan

2011-10-14

Self-assembled graphene organogel (SGO) with 3-dimensional (3D) macrostructure was prepared by solvothermal reduction of a graphene oxide (GO) dispersion in propylene carbonate (PC). This SGO was used as an electrode material for fabricating supercapacitors with a PC electrolyte. The supercapacitor can be operated in a wide voltage range of 0-3 V and exhibits a high specific capacitance of 140 F g(-1) at a discharge current density of 1 A g(-1). Furthermore, it can still keep a specific capacitance of 90 F g(-1) at a high current density of 30 A g(-1). The maximum energy density of the SGO based supercapacitor was tested to be 43.5 Wh kg(-1), and this value is higher than those of the graphene based supercapacitors with aqueous or PC electrolytes reported previously. Furthermore, at a high discharge current density of 30 A g(-1), the energy and power densities of the supercapacitor were measured to be 15.4 Wh kg(-1) and 16,300 W kg(-1), respectively. These results indicate that the supercapacitor has a high specific capacitance and power density, and excellent rate capability.

One-Dimensional Porous Silicon Nanowires with Large Surface Area for Fast Charge⁻Discharge Lithium-Ion Batteries.

PubMed

Chen, Xu; Bi, Qinsong; Sajjad, Muhammad; Wang, Xu; Ren, Yang; Zhou, Xiaowei; Xu, Wen; Liu, Zhu

2018-04-27

In this study, one-dimensional porous silicon nanowire (1D⁻PSiNW) arrays were fabricated by one-step metal-assisted chemical etching (MACE) to etch phosphorus-doped silicon wafers. The as-prepared mesoporous 1D⁻PSiNW arrays here had especially high specific surface areas of 323.47 m²·g -1 and were applied as anodes to achieve fast charge⁻discharge performance for lithium ion batteries (LIBs). The 1D⁻PSiNWs anodes with feature size of ~7 nm exhibited reversible specific capacity of 2061.1 mAh·g -1 after 1000 cycles at a high current density of 1.5 A·g -1 . Moreover, under the ultrafast charge⁻discharge current rate of 16.0 A·g -1 , the 1D⁻PSiNWs anodes still maintained 586.7 mAh·g -1 capacity even after 5000 cycles. This nanoporous 1D⁻PSiNW with high surface area is a potential anode candidate for the ultrafast charge⁻discharge in LIBs with high specific capacity and superior cycling performance.

The diageotropica mutant of tomato lacks high specific activity auxin binding sites

NASA Technical Reports Server (NTRS)

Hicks, G. R.; Rayle, D. L.; Lomax, T. L.

1989-01-01

Tomato plants homozygous for the diageotropica (dgt) mutation exhibit morphological and physiological abnormalities which suggest that they are unable to respond to the plant growth hormone auxin (indole-3-acetic acid). The photoaffinity auxin analog [3H]5N3-IAA specifically labels a polypeptide doublet of 40 and 42 kilodaltons in membrane preparations from stems of the parental variety, VFN8, but not from stems of plants containing the dgt mutation. In roots of the mutant plants, however, labeling is indistinguishable from that in VFN8. These data suggest that the two polypeptides are part of a physiologically important auxin receptor system, which is altered in a tissue-specific manner in the mutant.

Plasma sex steroid binding in Chiroptera.

PubMed

Kwiecinski, G G; Damassa, D A; Gustafson, A W; Armao, M E

1987-04-01

Plasma steroid binding was examined in samples obtained from seven species of bats representing four different families. A specific sex steroid-binding protein (SBP) was identified by steady-state polyacrylamide gel electrophoresis in representatives of two families, the phyllostomids and the vespertilionids. In these species, as in primates, SBP not only exhibited high affinity for the androgens testosterone and dihydrotestosterone (DHT), but also for estradiol. A specific SBP was not identified in the tropical American vampire bat or in the two species of pteropodids examined. In all species examined, except for the vampire bat, a specific corticosteroid-binding globulin (CBG) was also identified. In addition to binding glucocorticoids, CBG in these species appeared to bind androgens as well.

Vestibular blueprint in early vertebrates.

PubMed

Straka, Hans; Baker, Robert

2013-11-19

Central vestibular neurons form identifiable subgroups within the boundaries of classically outlined octavolateral nuclei in primitive vertebrates that are distinct from those processing lateral line, electrosensory, and auditory signals. Each vestibular subgroup exhibits a particular morpho-physiological property that receives origin-specific sensory inputs from semicircular canal and otolith organs. Behaviorally characterized phenotypes send discrete axonal projections to extraocular, spinal, and cerebellar targets including other ipsi- and contralateral vestibular nuclei. The anatomical locations of vestibuloocular and vestibulospinal neurons correlate with genetically defined hindbrain compartments that are well conserved throughout vertebrate evolution though some variability exists in fossil and extant vertebrate species. The different vestibular subgroups exhibit a robust sensorimotor signal processing complemented with a high degree of vestibular and visual adaptive plasticity.

Runners with Patellofemoral Pain Exhibit Greater Peak Patella Cartilage Stress Compared to Pain-Free Runners.

PubMed

Liao, Tzu-Chieh; Keyak, Joyce H; Powers, Christopher M

2018-02-27

The purpose of this study is to determine whether recreational runners with patellofemoral pain (PFP) exhibit greater peak patella cartilage stress compared to pain-free runners. A secondary purpose was to determine the kinematic and/or kinetic predictors of peak patella cartilage stress during running. Twenty-two female recreational runners participated (12 with PFP and 10 pain-free controls). Patella cartilage stress profiles were quantified using subject-specific finite element models simulating the maximum knee flexion angle during stance phase of running. Input parameters to the finite element model included subject-specific patellofemoral joint geometry, quadriceps muscle forces, and lower extremity kinematics in the frontal and transverse planes. Tibiofemoral joint kinematics and kinetics were quantified to determine the best predictor of stress using stepwise regression analysis. Compared to the pain-free runners, those with PFP exhibited greater peak hydrostatic pressure (PFP vs. control, 21.2 ± 5.6 MPa vs. 16.5 ± 4.6 MPa) and maximum shear stress (11.3 ± 4.6 MPa vs. 8.7 ± 2.3 MPa). Knee external rotation was the best predictor of peak hydrostatic pressure and peak maximum shear stress (38% and 25% of variances, respectively) followed by the knee extensor moment (21% and 25% of variances, respectively). Runners with PFP exhibit greater peak patella cartilage stress during running compared to pain-free individuals. The combination of knee external rotation and a high knee extensor moment best predicted elevated peak stress during running.

Prepared multifunctional aerogel for high performance supercapacitors and effective adsorbents

NASA Astrophysics Data System (ADS)

Zhang, Yimei; Wang, Fei; Ou, Ping; Zhu, Hao; Zhao, Yalong; Wang, Liquan; Chen, Zhuang; Li, Shuai

2018-05-01

Energy and environment as the current research hots pot, how to effectively combine the two is very important and full of challenge. In this research, we design a new type multifunctional aerogel material, which not only can applied for supuercapacitors, but also acted as adsorbents for adsorb organic pollutant. This multifunctional aerogel was prepared by one-pot hydrothermal and freeze-drying method based on elongated TiO2 nanotubes (eTNTs) and graphene. During the hydrothermal process, the graphene nanosheets and eTNTs self-assembled into three-dimensional (3D) interconnected networks, in which the eTNTs with uniform size are intercalate the pore interconnected framework. The results show that the as-prepared eTNTs/graphene aerogel (TGA) exhibits a high specific surface area of 343.2 m2 g‑1. The highly porous and interconnected 3D nanostructure provided efficient migration of electrolyte ions and electrons, and thus the TGA exhibited excellent electrochemical performance for supercapacitors. The binder free TGA electrode possessed high performance electrochemical properties with an excellent specific capacitance (476.8 F g‑1 at scan rate of 5 mV s‑1), and outstanding cycle stability (92% capacitance retention after 5000 cycles). In addition, the TGA also showed admirable adsorption capacity for organic pollutant of bisphenol A, which reached 523.5 mg g‑1. The excellent electrochemical and adsorption capacities suggest the TGA to be the promising materials application in energy storage and environmental remediation.

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

Rubin, M. B.; Vorobiev, O.; Vitali, E.

Here, a large deformation thermomechanical model is developed for shock loading of a material that can exhibit elastic and inelastic anisotropy. Use is made of evolution equations for a triad of microstructural vectors m i(i=1,2,3) which model elastic deformations and directions of anisotropy. Specific constitutive equations are presented for a material with orthotropic elastic response. The rate of inelasticity depends on an orthotropic yield function that can be used to model weak fault planes with failure in shear and which exhibits a smooth transition to isotropic response at high compression. Moreover, a robust, strongly objective numerical algorithm is proposed formore » both rate-independent and rate-dependent response. The predictions of the continuum model are examined by comparison with exact steady-state solutions. Also, the constitutive equations are used to obtain a simplified continuum model of jointed rock which is compared with high fidelity numerical solutions that model a persistent system of joints explicitly in the rock medium.« less

A rhodamine B-based fluorescent sensor toward highly selective mercury (II) ions detection.

PubMed

Jiao, Yang; Zhang, Lei; Zhou, Peng

2016-04-01

This work presented the design, syntheses and photophysical properties of a rhodamine B-based fluorescence probe, which exhibited a sensitive and selective recognition towards mercury (II). The chemosensor RA (Rhodamine- amide- derivative) contained a 5-aminoisophthalic acid diethyl ester and a rhodamine group, and the property of spirolactone of this chemosensor RA was detected by X-ray crystal structure analyses. Chemosensor RA afforded turn-on fluorescence enhancement and displayed high brightness for Hg(2+), which leaded to the opening of the spirolactone ring and consequently caused the appearance of strong absorption at visible range, moreover, the obvious and characteristic color changed from colorless to pink was observed. We envisioned that the chemosensor RA exhibited a considerable specificity with two mercury (II) ions which was attributed to the open of spirolactone over other interference metal ions. Copyright © 2015 Elsevier B.V. All rights reserved.

Metal-free and Scalable Synthesis of Porous Hyper-cross-linked Polymers: Towards Applications in Liquid-Phase Adsorption.

PubMed

Schute, Kai; Rose, Marcus

2015-10-26

A metal-free route for the synthesis of hyper-cross-linked polymers (HCP) based on Brønsted acids such as trifluoromethanesulfonic acid as well as H2 SO4 is reported. It is an improved method compared to conventional synthesis strategies that use stoichiometric amounts of metal-based Lewis acids such as FeCl3 . The resulting high-performance adsorbents exhibit a permanent porosity with high specific surface areas up to 1842 m(2)  g(-1) . Easy scalability of the HCP synthesis is proven on the multi-gram scale. All chemo-physical properties are preserved. Water-vapor adsorption shows that the resulting materials exhibit an even more pronounced hydrophobicity compared to the conventionally prepared materials. The reduced surface polarity enhances the selectivity in the liquid-phase adsorption of the biogenic platform chemical 5-hydroxymethylfurfural. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optical systems fabricated by printing-based assembly

DOEpatents

Rogers, John; Nuzzo, Ralph; Meitl, Matthew; Menard, Etienne; Baca, Alfred J; Motala, Michael; Ahn, Jong-Hyun; Park, Sang-Il; Yu, Chang-Jae; Ko, Heung Cho; Stoykovich, Mark; Yoon, Jongseung

2014-05-13

Provided are optical devices and systems fabricated, at least in part, via printing-based assembly and integration of device components. In specific embodiments the present invention provides light emitting systems, light collecting systems, light sensing systems and photovoltaic systems comprising printable semiconductor elements, including large area, high performance macroelectronic devices. Optical systems of the present invention comprise semiconductor elements assembled, organized and/or integrated with other device components via printing techniques that exhibit performance characteristics and functionality comparable to single crystalline semiconductor based devices fabricated using conventional high temperature processing methods. Optical systems of the present invention have device geometries and configurations, such as form factors, component densities, and component positions, accessed by printing that provide a range of useful device functionalities. Optical systems of the present invention include devices and device arrays exhibiting a range of useful physical and mechanical properties including flexibility, shapeability, conformability and stretchablity.

Optical systems fabricated by printing-based assembly

DOEpatents

Rogers, John [Champaign, IL; Nuzzo, Ralph [Champaign, IL; Meitl, Matthew [Durham, NC; Menard, Etienne [Durham, NC; Baca, Alfred J [Urbana, IL; Motala, Michael [Champaign, IL; Ahn, Jong-Hyun [Suwon, KR; Park, Sang-II [Savoy, IL; Yu,; Chang-Jae, [Urbana, IL; Ko, Heung-Cho [Gwangju, KR; Stoykovich,; Mark, [Dover, NH; Yoon, Jongseung [Urbana, IL

2011-07-05

Provided are optical devices and systems fabricated, at least in part, via printing-based assembly and integration of device components. In specific embodiments the present invention provides light emitting systems, light collecting systems, light sensing systems and photovoltaic systems comprising printable semiconductor elements, including large area, high performance macroelectronic devices. Optical systems of the present invention comprise semiconductor elements assembled, organized and/or integrated with other device components via printing techniques that exhibit performance characteristics and functionality comparable to single crystalline semiconductor based devices fabricated using conventional high temperature processing methods. Optical systems of the present invention have device geometries and configurations, such as form factors, component densities, and component positions, accessed by printing that provide a range of useful device functionalities. Optical systems of the present invention include devices and device arrays exhibiting a range of useful physical and mechanical properties including flexibility, shapeability, conformability and stretchablity.

Greed, death, and values: from terror management to transcendence management theory.

PubMed

Cozzolino, Philip J; Staples, Angela D; Meyers, Lawrence S; Samboceti, Jamie

2004-03-01

Research supporting terror management theory has shown that participants facing their death (via mortality salience) exhibit more greed than do control participants. The present research attempts to distinguish mortality salience from other forms of mortality awareness. Specifically, the authors look to reports of near-death experiences and posttraumatic growth which reveal that many people who nearly die come to view seeking wealth and possession as empty and meaningless. Guided by these reports, a manipulation called death reflection was generated. In Study 1, highly extrinsic participants who experienced death reflection exhibited intrinsic behavior. In Study 2, the manipulation was validated, and in Study 3, death reflection and mortality salience manipulations were compared. Results showed that mortality salience led highly extrinsic participants to manifest greed, whereas death reflection again generated intrinsic, unselfish behavior. The construct of value orientation is discussed along with the contrast between death reflection manipulation and mortality salience.

Optical systems fabricated by printing-based assembly

DOEpatents

Rogers, John; Nuzzo, Ralph; Meitl, Matthew; Menard, Etienne; Baca, Alfred; Motala, Michael; Ahn, Jong -Hyun; Park, Sang -Il; Yu, Chang -Jae; Ko, Heung Cho; Stoykovich, Mark; Yoon, Jongseung

2015-08-25

Provided are optical devices and systems fabricated, at least in part, via printing-based assembly and integration of device components. In specific embodiments the present invention provides light emitting systems, light collecting systems, light sensing systems and photovoltaic systems comprising printable semiconductor elements, including large area, high performance macroelectronic devices. Optical systems of the present invention comprise semiconductor elements assembled, organized and/or integrated with other device components via printing techniques that exhibit performance characteristics and functionality comparable to single crystalline semiconductor based devices fabricated using conventional high temperature processing methods. Optical systems of the present invention have device geometries and configurations, such as form factors, component densities, and component positions, accessed by printing that provide a range of useful device functionalities. Optical systems of the present invention include devices and device arrays exhibiting a range of useful physical and mechanical properties including flexibility, shapeability, conformability and stretchablity.

Optical systems fabricated by printing-based assembly

DOEpatents

Rogers, John; Nuzzo, Ralph; Meitl, Matthew; Menard, Etienne; Baca, Alfred; Motala, Michael; Ahn, Jong-Hyun; Park, Sang-Il; Yu, Chang-Jae; Ko, Heung Cho; Stoykovich, Mark; Yoon, Jongseung

2017-03-21

Provided are optical devices and systems fabricated, at least in part, via printing-based assembly and integration of device components. In specific embodiments the present invention provides light emitting systems, light collecting systems, light sensing systems and photovoltaic systems comprising printable semiconductor elements, including large area, high performance macroelectronic devices. Optical systems of the present invention comprise semiconductor elements assembled, organized and/or integrated with other device components via printing techniques that exhibit performance characteristics and functionality comparable to single crystalline semiconductor based devices fabricated using conventional high temperature processing methods. Optical systems of the present invention have device geometries and configurations, such as form factors, component densities, and component positions, accessed by printing that provide a range of useful device functionalities. Optical systems of the present invention include devices and device arrays exhibiting a range of useful physical and mechanical properties including flexibility, shapeability, conformability and stretchablity.

Promoting social behavior with oxytocin in high-functioning autism spectrum disorders.

PubMed

Andari, Elissar; Duhamel, Jean-René; Zalla, Tiziana; Herbrecht, Evelyn; Leboyer, Marion; Sirigu, Angela

2010-03-02

Social adaptation requires specific cognitive and emotional competences. Individuals with high-functioning autism or with Asperger syndrome cannot understand or engage in social situations despite preserved intellectual abilities. Recently, it has been suggested that oxytocin, a hormone known to promote mother-infant bonds, may be implicated in the social deficit of autism. We investigated the behavioral effects of oxytocin in 13 subjects with autism. In a simulated ball game where participants interacted with fictitious partners, we found that after oxytocin inhalation, patients exhibited stronger interactions with the most socially cooperative partner and reported enhanced feelings of trust and preference. Also, during free viewing of pictures of faces, oxytocin selectively increased patients' gazing time on the socially informative region of the face, namely the eyes. Thus, under oxytocin, patients respond more strongly to others and exhibit more appropriate social behavior and affect, suggesting a therapeutic potential of oxytocin through its action on a core dimension of autism.

Tissue-Specific Inactivation of Type 2 Deiodinase Reveals Multilevel Control of Fatty Acid Oxidation by Thyroid Hormone in the Mouse

PubMed Central

Fonseca, Tatiana L.; Werneck-De-Castro, Joao Pedro; Castillo, Melany; Bocco, Barbara M.L.C.; Fernandes, Gustavo W.; McAninch, Elizabeth A.; Ignacio, Daniele L.; Moises, Caio C.S.; Ferreira, Alexandre; Gereben, Balázs

2014-01-01

Type 2 deiodinase (D2) converts the prohormone thyroxine (T4) to the metabolically active molecule 3,5,3′-triiodothyronine (T3), but its global inactivation unexpectedly lowers the respiratory exchange rate (respiratory quotient [RQ]) and decreases food intake. Here we used FloxD2 mice to generate systemically euthyroid fat-specific (FAT), astrocyte-specific (ASTRO), or skeletal-muscle-specific (SKM) D2 knockout (D2KO) mice that were monitored continuously. The ASTRO-D2KO mice also exhibited lower diurnal RQ and greater contribution of fatty acid oxidation to energy expenditure, but no differences in food intake were observed. In contrast, the FAT-D2KO mouse exhibited sustained (24 h) increase in RQ values, increased food intake, tolerance to glucose, and sensitivity to insulin, all supporting greater contribution of carbohydrate oxidation to energy expenditure. Furthermore, FAT-D2KO animals that were kept on a high-fat diet for 8 weeks gained more body weight and fat, indicating impaired brown adipose tissue (BAT) thermogenesis and/or inability to oxidize the fat excess. Acclimatization of FAT-D2KO mice at thermoneutrality dissipated both features of this phenotype. Muscle D2 does not seem to play a significant metabolic role given that SKM-D2KO animals exhibited no phenotype. The present findings are unique in that they were obtained in systemically euthyroid animals, revealing that brain D2 plays a dominant albeit indirect role in fatty acid oxidation via its sympathetic control of BAT activity. D2-generated T3 in BAT accelerates fatty acid oxidation and protects against diet-induced obesity. PMID:24487027

Tissue-specific inactivation of type 2 deiodinase reveals multilevel control of fatty acid oxidation by thyroid hormone in the mouse.

PubMed

Fonseca, Tatiana L; Werneck-De-Castro, Joao Pedro; Castillo, Melany; Bocco, Barbara M L C; Fernandes, Gustavo W; McAninch, Elizabeth A; Ignacio, Daniele L; Moises, Caio C S; Ferreira, Alexander R; Ferreira, Alexandre; Gereben, Balázs; Bianco, Antonio C

2014-05-01

Type 2 deiodinase (D2) converts the prohormone thyroxine (T4) to the metabolically active molecule 3,5,3'-triiodothyronine (T3), but its global inactivation unexpectedly lowers the respiratory exchange rate (respiratory quotient [RQ]) and decreases food intake. Here we used FloxD2 mice to generate systemically euthyroid fat-specific (FAT), astrocyte-specific (ASTRO), or skeletal-muscle-specific (SKM) D2 knockout (D2KO) mice that were monitored continuously. The ASTRO-D2KO mice also exhibited lower diurnal RQ and greater contribution of fatty acid oxidation to energy expenditure, but no differences in food intake were observed. In contrast, the FAT-D2KO mouse exhibited sustained (24 h) increase in RQ values, increased food intake, tolerance to glucose, and sensitivity to insulin, all supporting greater contribution of carbohydrate oxidation to energy expenditure. Furthermore, FAT-D2KO animals that were kept on a high-fat diet for 8 weeks gained more body weight and fat, indicating impaired brown adipose tissue (BAT) thermogenesis and/or inability to oxidize the fat excess. Acclimatization of FAT-D2KO mice at thermoneutrality dissipated both features of this phenotype. Muscle D2 does not seem to play a significant metabolic role given that SKM-D2KO animals exhibited no phenotype. The present findings are unique in that they were obtained in systemically euthyroid animals, revealing that brain D2 plays a dominant albeit indirect role in fatty acid oxidation via its sympathetic control of BAT activity. D2-generated T3 in BAT accelerates fatty acid oxidation and protects against diet-induced obesity.

Characterization of plasma membrane domains of mouse EL4 lymphoma cells obtained by affinity chromatography on concanavalin A-Sepharose.

PubMed

Szamel, M; Goppelt, M; Resch, K

1985-12-19

Purified plasma membranes of mouse EL4 lymphoma cells were fractionated by means of affinity chromatography on concanavalin A-Sepharose into two subfractions; one (MF1) eluted freely from the affinity column, the second (MF2) adhered specifically to Con A-Sepharose. Both membrane subfractions proved to be of plasma membrane origin, as evidenced by the following criteria. (i) The ratio of cholesterol to phospholipid was nearly identical in plasma membrane and both subfractions. (ii) When isolated plasma membranes were labelled with tritiated NaBH4, both subfractions exhibited identical specific radioactivities. (iii) After enzymatic radioiodination of the cells, the total content of labelled proteins was very similar in isolated plasma membranes and in both subfractions. (iv) Some plasma membrane marker enzymes exhibited nearly identical specific activities in plasma membranes, MF1 or MF2 including gamma-glutamyl transpeptidase, 5'-nucleotidase and Mg2+-ATPase. Both subfractions exhibited characteristic differences. Thus the specific activities of (Na+ + K+)-ATPase, Ca2+-ATPase and lysophosphatidylcholine acyltransferase were several-fold enriched in MF2 compared to MF1. SDS-polyacrylamide gel electrophoresis revealed a different polypeptide composition of the two subfractions. Polypeptides of apparent molecular mass of 116, 95, 42, 39, 30 and 28 kDa were highly enriched in MF2, whereas MF1 contained another set of proteins, of apparent molecular mass of 70, 55 and 24 kDa. The phospholipid fatty acid composition of the subfractions proved to be different, as well, MF2 contained more saturated fatty acids than MF1. The data suggest the existence of plasma membrane domains in the plasma membranes of the mouse EL4 lymphoma cells, containing a set of polypeptides, among others membrane bound enzymes, embedded in a different phospholipid milieu.

Covalent Organic Frameworks as a Decorating Platform for Utilization and Affinity Enhancement of Chelating Sites for Radionuclide Sequestration

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

Sun, Qi; Aguila, Briana; Earl, Lyndsey D.

The potential consequences of nuclear events and the complexity of nuclear waste management motivate the development of selective solid-phase sorbents to provide enhanced protection. In this paper, it is shown that 2D covalent organic frameworks (COFs) with unique structures possess all the traits to be well suited as a platform for the deployment of highly efficient sorbents such that they exhibit remarkable performance, as demonstrated by uranium capture. The chelating groups laced on the open 1D channels exhibit exceptional accessibility, allowing significantly higher utilization efficiency. In addition, the 2D extended polygons packed closely in an eclipsed fashion bring chelating groupsmore » in adjacent layers parallel to each other, which may facilitate their cooperation, thereby leading to high affinity toward specific ions. As a result, the amidoxime-functionalized COFs far outperform their corresponding amorphous analogs in terms of adsorption capacities, kinetics, and affinities. Specifically, COF-TpAb-AO is able to reduce various uranium contaminated water samples from 1 ppm to less than 0.1 ppb within several minutes, well below the drinking water limit (30 ppb), as well as mine uranium from spiked seawater with an exceptionally high uptake capacity of 127 mg g -1. Finally, these results delineate important synthetic advances toward the implementation of COFs in environmental remediation.« less

Molten salt synthesis of nitrogen and oxygen enriched hierarchically porous carbons derived from biomass via rapid microwave carbonization for high voltage supercapacitors

NASA Astrophysics Data System (ADS)

Cheng, Yinfeng; Li, Baoqiang; Huang, Yanjuan; Wang, Yaming; Chen, Junchen; Wei, Daqing; Feng, Yujie; Jia, Dechang; Zhou, Yu

2018-05-01

Nitrogen and oxygen enriched hierarchically porous carbons (NOHPCs) derived from biomass have been successfully prepared by rapid microwave carbonization coupled with molten salt synthesis method in only 4 min. ZnCl2 plays important roles as microwave absorber, chemical activation agent and porogen in this process. NOHPC-1:10 sample possesses the maximum specific surface area of 1899 m2 g-1 with a pore volume of 1.16 cm3 g-1 and mesopore ratio of 70%, as well as nitrogen content of 5.30 wt% and oxygen content of 14.12 wt%. When evaluated as an electrode in a three-electrode system with 6 M KOH electrolyte, the material exhibits a high specific capacitance of 276 F g-1 at 0.2 A g-1, with a good rate capability of 90.9% retention at 10 A g-1. More importantly, the symmetric supercapacitor based on NOHPC-1:10 in 1 M Na2SO4 electrolyte exhibits a high energy density of 13.9 Wh kg-1 at a power density of 120 W kg-1 in a wide voltage window of 0-1.6 V, an excellent cycling stability with 95% of capacitance retention after 10,000 cycles. Our strategy provides a facile and rapid way for the preparation of advanced carbon materials derived from biomass towards energy storage applications.

Covalent Organic Frameworks as a Decorating Platform for Utilization and Affinity Enhancement of Chelating Sites for Radionuclide Sequestration

DOE PAGES

Sun, Qi; Aguila, Briana; Earl, Lyndsey D.; ...

2018-03-27

The potential consequences of nuclear events and the complexity of nuclear waste management motivate the development of selective solid-phase sorbents to provide enhanced protection. In this paper, it is shown that 2D covalent organic frameworks (COFs) with unique structures possess all the traits to be well suited as a platform for the deployment of highly efficient sorbents such that they exhibit remarkable performance, as demonstrated by uranium capture. The chelating groups laced on the open 1D channels exhibit exceptional accessibility, allowing significantly higher utilization efficiency. In addition, the 2D extended polygons packed closely in an eclipsed fashion bring chelating groupsmore » in adjacent layers parallel to each other, which may facilitate their cooperation, thereby leading to high affinity toward specific ions. As a result, the amidoxime-functionalized COFs far outperform their corresponding amorphous analogs in terms of adsorption capacities, kinetics, and affinities. Specifically, COF-TpAb-AO is able to reduce various uranium contaminated water samples from 1 ppm to less than 0.1 ppb within several minutes, well below the drinking water limit (30 ppb), as well as mine uranium from spiked seawater with an exceptionally high uptake capacity of 127 mg g -1. Finally, these results delineate important synthetic advances toward the implementation of COFs in environmental remediation.« less

Developmental programming of appetite/satiety.

PubMed

Ross, Michael G; Desai, Mina

2014-01-01

Obesity is often attributed to a Western lifestyle, a high-fat diet and decreased activity. While these factors certainly contribute to adult obesity, compelling data from our laboratory and others indicate that this explanation is oversimplified. Recent studies strongly argue that maternal/fetal under- or overnutrition predisposes the offspring to become hyperphagic and increases the risk of later obesity. Both infants small for gestational age (SGA) or infants born to obese mothers who consume a high-fat diet are at a markedly increased risk of adult obesity. Specific alterations in the fetal metabolic/energy environment directly influence the development of appetite regulatory pathways. Specifically, SGA infants demonstrate (1) impaired satiety and anorexigenic cell signaling, (2) enhanced cellular orexigenic responses, (3) programmed dysfunction of neuroprogenitor cell proliferation/differentiation, and (4) increased expression of appetite (NPY) versus satiety (POMC) neurons. In both hypothalamic tissue and ex vivo culture, SGA newborns exhibit increased levels of the nutrient sensor SIRT1, signifying reduced energy, whereas maternal high-fat-exposed newborns exhibit reduced levels of pAMPK, signifying energy excess. Via downstream regulation of bHLH neuroproliferation (Hes1) and neurodifferentiation factors (Mash1, Ngn3), neurogenesis is biased toward orexigenic and away from anorexigenic neurons, resulting in excess appetite, reduced satiety and development of obesity. Despite the developmental programming of appetite neurogenesis, the potential for neuronal remodeling raises the opportunity for novel interventions.

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

Das, Atanu Kumar; Vemuri, Rama Sesha; Kutnyakov, Igor

Here, vapor-assisted dry-gel synthesis of MOF-74 structure, specifically NiMOF-74 from its synthetic precursors, was conducted with high yield and improved performance showing promise for gas (CO 2) and water adsorption applications. Unlike conventional synthesis, which takes 72 h, this kinetic study showed that NiMOF-74 forms within 12 h under dry-gel conditions with similar performance characteristics and exhibits the best performance characteristics after 48 h of heating.

Fabrication of nickel-foam-supported layered zinc-cobalt hydroxide nanoflakes for high electrochemical performance in supercapacitors.

PubMed

Yuan, Peng; Zhang, Ning; Zhang, Dan; Liu, Tao; Chen, Limiao; Liu, Xiaohe; Ma, Renzhi; Qiu, Guanzhou

2014-10-04

Nickel foam supported Zn-Co hydroxide nanoflakes were fabricated by a facile solvothermal method. Benefited from the unique structure of Zn-Co hydroxide nanoflakes on a nickel foam substrate, the as prepared materials exhibited an excellent specific capacitance of 901 F g(-1) at 5 A g(-1) and remarkable cycling stability as electrode materials in supercapacitors.

Plasma-induced highly efficient synthesis of boron doped reduced graphene oxide for supercapacitors.

PubMed

Li, Shaobo; Wang, Zhaofeng; Jiang, Hanmei; Zhang, Limei; Ren, Jingzheng; Zheng, Mingtao; Dong, Lichun; Sun, Luyi

2016-09-21

In this work, we presented a novel route to synthesize boron doped reduced graphene oxide (rGO) by using the dielectric barrier discharge (DBD) plasma technology under ambient conditions. The doping of boron (1.4 at%) led to a significant improvement in the capacitance of rGO and supercapacitors based on the as-synthesized B-rGO exhibited an outstanding specific capacitance.

Computational evidence for stable inorganic fullerene-like structures of ceramic and semiconductor materials

NASA Astrophysics Data System (ADS)

Chang, Ch; Patzer, A. B. C.; Sedlmayr, E.; Steinke, T.; Sülzle, D.

2001-12-01

Theoretical electronic structure techniques have become an indispensible and powerful means for predicting molecular properties and designing new materials. Based on a density functional approach and guided by geometric considerations we provide evidence for some specific inorganic fullerene-like cage molecules of ceramic and semiconductor materials which exhibit high energetic stability and point group symmetry as well as nearly perfect spherical shape.

Soft-Template Construction of 3D Macroporous Polypyrrole Scaffolds.

PubMed

Liu, Shaohua; Wang, Faxing; Dong, Renhao; Zhang, Tao; Zhang, Jian; Zheng, Zhikun; Mai, Yiyong; Feng, Xinliang

2017-04-01

A bottom-up approach toward 3D hierarchical macroporous polypyrrole aerogels is demonstrated via soft template-directed synthesis and self-assembly of ultrathin polypyrrole nanosheets in solution, which present interconnected macropores, ultrathin walls, and large specific surface areas, thereby exhibiting a high capacity, satisfactory rate capability, and excellent cycling stability for Na-ion storage. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Wnt-Lrp5 Signaling Regulates Fatty Acid Metabolism in the Osteoblast

PubMed Central

Frey, Julie L.; Li, Zhu; Ellis, Jessica M.; Zhang, Qian; Farber, Charles R.; Aja, Susan; Wolfgang, Michael J.; Clemens, Thomas L.

2015-01-01

The Wnt coreceptors Lrp5 and Lrp6 are essential for normal postnatal bone accrual and osteoblast function. In this study, we identify a previously unrecognized skeletal function unique to Lrp5 that enables osteoblasts to oxidize fatty acids. Mice lacking the Lrp5 coreceptor specifically in osteoblasts and osteocytes exhibit the expected reductions in postnatal bone mass but also exhibit an increase in body fat with corresponding reductions in energy expenditure. Conversely, mice expressing a high bone mass mutant Lrp5 allele are leaner with reduced plasma triglyceride and free fatty acid levels. In this context, Wnt-initiated signals downstream of Lrp5, but not the closely related Lrp6 coreceptor, regulate the activation of β-catenin and thereby induce the expression of key enzymes required for fatty acid β-oxidation. These results suggest that Wnt-Lrp5 signaling regulates basic cellular activities beyond those associated with fate specification and differentiation in bone and that the skeleton influences global energy homeostasis via mechanisms independent of osteocalcin and glucose metabolism. PMID:25802278

Confined semiflexible polymers suppress fluctuations of soft membrane tubes.

PubMed

Mirzaeifard, Sina; Abel, Steven M

2016-02-14

We use Monte Carlo computer simulations to investigate tubular membrane structures with and without semiflexible polymers confined inside. At small values of membrane bending rigidity, empty fluid and non-fluid membrane tubes exhibit markedly different behavior, with fluid membranes adopting irregular, highly fluctuating shapes and non-fluid membranes maintaining extended tube-like structures. Fluid membranes, unlike non-fluid membranes, exhibit a local maximum in specific heat as their bending rigidity increases. The peak is coincident with a transition to extended tube-like structures. We further find that confining a semiflexible polymer within a fluid membrane tube reduces the specific heat of the membrane, which is a consequence of suppressed membrane shape fluctuations. Polymers with a sufficiently large persistence length can significantly deform the membrane tube, with long polymers leading to localized bulges in the membrane that accommodate regions in which the polymer forms loops. Analytical calculations of the energies of idealized polymer-membrane configurations provide additional insight into the formation of polymer-induced membrane deformations.

Waste separation and pretreatment using crystalline silicotitanate ion exchangers

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

Tadros, M.E.; Miller, J.E.; Anthony, R.G.

1997-10-01

A new class of inorganic ion exchangers called crystalline silicotitanates (CSTs) has been developed jointly by Sandia National Laboratories and Texas A&M University to selectively remove Cs and other radionuclides from a wide spectrum of radioactive defense wastes. The CST exhibits high selectivity and affinity for Cs and Sr under a wide range of conditions. Tests show it can remove part-per-million concentrations of Cs{sup +} from highly alkaline, high-sodium simulated radioactive waste solutions modeled after those at Hanford, Oak Ridge, and Savannah River. The materials exhibit ion exchange properties based on ionic size selectivity. Specifically, crystalline lattice spacing is controlledmore » to be highly selective for Cs ions even in waste streams containing very high (5 to 10 M) concentrations of sodium. The CST technology is being demonstrated with actual waste at several DOE facilities. The use of inorganic ion exchangers. The inorganics are more resistant to chemical, thermal, and radiation degradation. Their high selectivities result in more efficient operations offering the possibility of a simple single-pass operation. In contrast, regenerable organic ion exchangers require additional processing equipment to handle the regeneration liquids and the eluant with the dissolved Cs.« less

Self-Healing Polymer Dielectric for a High Capacitance Gate Insulator.

PubMed

Ko, Jieun; Kim, Young-Jae; Kim, Youn Sang

2016-09-14

Self-healing materials are required for development of various flexible electronic devices to repair cracks and ruptures caused by repetitive bending or folding. Specifically, a self-healing dielectric layer has huge potential to achieve healing electronics without mechanical breakdown in flexible operations. Here, we developed a high performance self-healing dielectric layer with an ionic liquid and catechol-functionalized polymer which exhibited a self-healing ability for both bulk and film states under mild self-healing conditions at 55 °C for 30 min. Due to the sufficient ion mobility of the ionic liquid in the polymer matrix, it had a high capacitance value above 1 μF/cm(2) at 20 Hz. Moreover, zinc oxide (ZnO) thin-film transistors (TFTs) with a self-healing dielectric layer exhibited a high field-effect mobility of 16.1 ± 3.07 cm(2) V(-1) s(-1) at a gate bias of 3 V. Even after repetitive self-healing of the dielectric layer from mechanical breaking, the electrical performance of the TFTs was well-maintained.

The strain-rate sensitivity of high-strength high-toughness steels.

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

Dilmore, M.F.; Crenshaw, Thomas B.; Boyce, Brad Lee

2006-01-01

The present study examines the strain-rate sensitivity of four high strength, high-toughness alloys at strain rates ranging from 0.0002 s-1 to 200 s-1: Aermet 100, a modified 4340, modified HP9-4-20, and a recently developed Eglin AFB steel alloy, ES-1c. A refined dynamic servohydraulic method was used to perform tensile tests over this entire range. Each of these alloys exhibit only modest strain-rate sensitivity. Specifically, the strain-rate sensitivity exponent m, is found to be in the range of 0.004-0.007 depending on the alloy. This corresponds to a {approx}10% increase in the yield strength over the 7-orders of magnitude change in strain-rate.more » Interestingly, while three of the alloys showed a concominant {approx}3-10% drop in their ductility with increasing strain-rate, the ES1-c alloy actually exhibited a 25% increase in ductility with increasing strain-rate. Fractography suggests the possibility that at higher strain-rates ES-1c evolves towards a more ductile dimple fracture mode associated with microvoid coalescence.« less

Antifungal Susceptibility and Phylogeny of Opportunistic Members of the Order Mucorales

PubMed Central

Vitale, Roxana G.; de Hoog, G. Sybren; Schwarz, Patrick; Dannaoui, Eric; Deng, Shuwen; Machouart, Marie; Voigt, Kerstin; van de Sande, Wendy W. J.; Dolatabadi, Somayeh; Meis, Jacques F.

2012-01-01

The in vitro susceptibilities of 66 molecularly identified strains of the Mucorales to eight antifungals (amphotericin B, terbinafine, itraconazole, posaconazole, voriconazole, caspofungin, micafungin, and 5-fluorocytosine) were tested. Molecular phylogeny was reconstructed based on the nuclear ribosomal large subunit to reveal taxon-specific susceptibility profiles. The impressive phylogenetic diversity of the Mucorales was reflected in susceptibilities differing at family, genus, and species levels. Amphotericin B was the most active drug, though somewhat less against Rhizopus and Cunninghamella species. Posaconazole was the second most effective antifungal agent but showed reduced activity in Mucor and Cunninghamella strains, while voriconazole lacked in vitro activity for most strains. Genera attributed to the Mucoraceae exhibited a wide range of MICs for posaconazole, itraconazole, and terbinafine and included resistant strains. Cunninghamella also comprised strains resistant to all azoles tested but was fully susceptible to terbinafine. In contrast, the Lichtheimiaceae completely lacked strains with reduced susceptibility for these antifungals. Syncephalastrum species exhibited susceptibility profiles similar to those of the Lichtheimiaceae. Mucor species were more resistant to azoles than Rhizopus species. Species-specific responses were obtained for terbinafine where only Rhizopus arrhizus and Mucor circinelloides were resistant. Complete or vast resistance was observed for 5-fluorocytosine, caspofungin, and micafungin. Intraspecific variability of in vitro susceptibility was found in all genera tested but was especially high in Mucor and Rhizopus for azoles and terbinafine. Accurate molecular identification of etiologic agents is compulsory to predict therapy outcome. For species of critical genera such as Mucor and Rhizopus, exhibiting high intraspecific variation, susceptibility testing before the onset of therapy is recommended. PMID:22075600

Antifungal susceptibility and phylogeny of opportunistic members of the order mucorales.

PubMed

Vitale, Roxana G; de Hoog, G Sybren; Schwarz, Patrick; Dannaoui, Eric; Deng, Shuwen; Machouart, Marie; Voigt, Kerstin; van de Sande, Wendy W J; Dolatabadi, Somayeh; Meis, Jacques F; Walther, Grit

2012-01-01

The in vitro susceptibilities of 66 molecularly identified strains of the Mucorales to eight antifungals (amphotericin B, terbinafine, itraconazole, posaconazole, voriconazole, caspofungin, micafungin, and 5-fluorocytosine) were tested. Molecular phylogeny was reconstructed based on the nuclear ribosomal large subunit to reveal taxon-specific susceptibility profiles. The impressive phylogenetic diversity of the Mucorales was reflected in susceptibilities differing at family, genus, and species levels. Amphotericin B was the most active drug, though somewhat less against Rhizopus and Cunninghamella species. Posaconazole was the second most effective antifungal agent but showed reduced activity in Mucor and Cunninghamella strains, while voriconazole lacked in vitro activity for most strains. Genera attributed to the Mucoraceae exhibited a wide range of MICs for posaconazole, itraconazole, and terbinafine and included resistant strains. Cunninghamella also comprised strains resistant to all azoles tested but was fully susceptible to terbinafine. In contrast, the Lichtheimiaceae completely lacked strains with reduced susceptibility for these antifungals. Syncephalastrum species exhibited susceptibility profiles similar to those of the Lichtheimiaceae. Mucor species were more resistant to azoles than Rhizopus species. Species-specific responses were obtained for terbinafine where only Rhizopus arrhizus and Mucor circinelloides were resistant. Complete or vast resistance was observed for 5-fluorocytosine, caspofungin, and micafungin. Intraspecific variability of in vitro susceptibility was found in all genera tested but was especially high in Mucor and Rhizopus for azoles and terbinafine. Accurate molecular identification of etiologic agents is compulsory to predict therapy outcome. For species of critical genera such as Mucor and Rhizopus, exhibiting high intraspecific variation, susceptibility testing before the onset of therapy is recommended.

Phenolics and antioxidant capacity of table grape (Vitis vinifera L.) cultivars grown in Chile.

PubMed

Lutz, Mariane; Jorquera, Katterin; Cancino, Beatriz; Ruby, Rene; Henriquez, Carolina

2011-09-01

Grapes (Vitis vinifera L.) possess health-promoting effects attributed to their supply of a wide variety of bioactive phenolics. Juice and skin fractions of 4 varieties of table grapes: Red Globe, Crimson Seedless, Autumn Royal, and Ribier were prepared to determine and compare their total phenolics content, antioxidant capacity (DPPH, FRAP, and ORAC), anthocyanins, and specific phenolics (caffeic acid, gallic acid, resveratrol, and catechin) content, since a series of positive health benefits are expected from the intake of any of these fractions. Higher amounts of total phenolics and antioxidant capacity were observed in the skin fractions (P < 0.05). Blue grapes (Autumn Royal and Ribier) exhibited higher phenolics content and antioxidant capacity (P < 0.05) than red grapes. The most abundant phenolic compound observed was catechin (P < 0.05). Significant correlations between the antioxidant capacity and total phenolics were observed in grape juice and skin fractions. Autumn Royal juice provides a very high amount of phenolics, anthocyanins, and exhibits the highest antioxidant capacity, offering the best health promoting properties compared with the other grape varieties studied. Grapes possess health-promoting effects attributed to their supply of a wide variety of bioactive phenolics. Grape juice made with blue grapes (Autumn Royal, Ribier) exhibit higher phenolics content and antioxidant capacity than juice elaborated with red grapes (Red Globe, Crimson Seedless). The skin is a good source of phenolics and has a high antioxidant capacity. Specific health-promoting phenolics are more abundant in blue grapes, mainly in their skin fraction, which should not be discarded. © 2011 Institute of Food Technologists®

Immunotherapy of acute radiation syndromes with antiradiation gamma G globulin.

NASA Astrophysics Data System (ADS)

Popov, Dmitri; Maliev, Vecheslav; Casey, Rachael; Jones, Jeffrey; Kedar, Prasad

Introduction: If an immunotherapy treatment approach to treatment of acute radiation syndromes (ARS) were to be developed; consideration could be given to neutralization of radiation toxins (Specific Radiation Determinants- SRD) by specific antiradiation antibodies. To accomplish this objective, irradiated animals were injected with a preparation of antiradiation immunoglobulin G (IgG) obtained from hyperimmune donors. Radiation-indeced toxins that we call Specific Radiation Determinants (SRD) possess toxic (neurotoxic, haemotoxic and enterotoxic) characteristics as well as specific antigenic properties that combined with the direct physiochemical direct radiation damage, induce the development of many of the pathological processes associated with ARS. We tested several specific hyperimmune IgG preparations against these radiation toxins and observed that their toxic properties were neutralized by specific antiradiation IgGs. Material and Methods: Rabbits were inoculated with SRD radiation toxins to induce hyperimmune serum. The hyperimmune serum was pooled from several animals, purified, and concentrated. Enzyme-linked immunosorbent assays of the hyperimmune serum revealed high titers of IgG with specific binding to radiation toxins. The antiradiation IgG preparation was injected into laboratory animals one hour before and three hours after irradiation, and was evaluated for its ability to protect inoculated animals against the development of acute radiation syndromes. Results: Animals that were inoculated with specific antiradiation antibodies before receiving lethal irradiation at LD 100/30 exhibited 60-75% survival rate at 30 days, whereas all control animals expired by 30 days following exposure. These inoculated animals also exhibited markedly reduced clinical symptoms of ARS, even those that did not survive irradiation. Discussion: The results of our experiments demonstrate that rabbit hyperimmune serum directed against SRD toxins afford significant, albeit incomplete, protection against high doses of radiation. In comparison, the mortality rate of irradiated control animals was 100% in the same time period. The mortality rates of hyperimmune serum-treated animals varied in different groups of animals and different forms of ARS; however, significant radioprotection was observed in each group treated with IgGs activated against specific radiation toxins.

Isolation of Mal d 1 and Api g 1 - specific recombinant antibodies from mouse IgG Fab fragment libraries - Mal d 1-specific antibody exhibits cross-reactivity against Bet v 1.

PubMed

Haka, Jaana; Niemi, Merja H; Iljin, Kristiina; Reddy, Vanga Siva; Takkinen, Kristiina; Laukkanen, Marja-Leena

2015-05-27

Around 3-5% of the population suffer from IgE-mediated food allergies in Western countries and the number of food-allergenic people is increasing. Individuals with certain pollen allergies may also suffer from a sensitisation to proteins in the food products. As an example a person sensitised to the major birch pollen allergen, Bet v 1, is often sensitised to its homologues, such as the major allergens of apple, Mal d 1, and celery, Api g 1, as well. Development of tools for the reliable, sensitive and quick detection of allergens present in various food products is essential for allergic persons to prevent the consumption of substances causing mild and even life-threatening immune responses. The use of monoclonal antibodies would ensure the specific detection of the harmful food content for a sensitised person. Mouse IgG antibody libraries were constructed from immunised mice and specific recombinant antibodies for Mal d 1 and Api g 1 were isolated from the libraries by phage display. More detailed characterisation of the resulting antibodies was carried out using ELISA, SPR experiments and immunoprecipitation assays. The allergen-specific Fab fragments exhibited high affinity towards the target recombinant allergens. Furthermore, the Fab fragments also recognised native allergens from natural sources. Interestingly, isolated Mal d 1-specific antibody bound also to Bet v 1, the main allergen eliciting the cross-reactivity syndrome between the birch pollen and apple. Despite the similarities in Api g 1 and Bet v 1 tertiary structures, the isolated Api g 1-specific antibodies showed no cross-reactivity to Bet v 1. Here, high-affinity allergen-specific recombinant antibodies were isolated with interesting binding properties. With further development, these antibodies can be utilised as tools for the specific and reliable detection of allergens from different consumable products. This study gives new preliminary insights to elucidate the mechanism behind the pollen-food syndrome and to study the IgG epitope of the allergens.

Bias-selectable dual-band mid-/long-wavelength infrared photodetectors based on InAs/InAs{sub 1−x}Sb{sub x} type-II superlattices

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

Haddadi, A.; Chevallier, R.; Chen, G.

2015-01-05

A high performance bias-selectable mid-/long-wavelength infrared photodetector based on InAs/InAs{sub 1−x}Sb{sub x} type-II superlattices on GaSb substrate has been demonstrated. The mid- and long-wavelength channels' 50% cut-off wavelengths were ∼5.1 and ∼9.5 μm at 77 K. The mid-wavelength channel exhibited a quantum efficiency of 45% at 100 mV bias voltage under front-side illumination and without any anti-reflection coating. With a dark current density of 1 × 10{sup −7} A/cm{sup 2} under 100 mV applied bias, the mid-wavelength channel exhibited a specific detectivity of 8.2 × 10{sup 12 }cm·√(Hz)/W at 77 K. The long-wavelength channel exhibited a quantum efficiency of 40%, a dark current density of 5.7 × 10{sup −4} A/cm{sup 2} undermore » −150 mV applied bias at 77 K, providing a specific detectivity value of 1.64 × 10{sup 11 }cm·√(Hz)/W.« less

Mesenchymal Stem Cells in Oriented PLGA/ACECM Composite Scaffolds Enhance Structure-Specific Regeneration of Hyaline Cartilage in a Rabbit Model

PubMed Central

Guo, Weimin; Zheng, Xifu; Zhang, Weiguo; Chen, Mingxue; Wang, Zhenyong; Hao, Chunxiang; Huang, Jingxiang; Yuan, Zhiguo; Zhang, Yu; Wang, Mingjie; Peng, Jiang; Wang, Aiyuan; Wang, Yu; Sui, Xiang; Xu, Wenjing

2018-01-01

Articular cartilage lacks a blood supply and nerves. Hence, articular cartilage regeneration remains a major challenge in orthopedics. Decellularized extracellular matrix- (ECM-) based strategies have recently received particular attention. The structure of native cartilage exhibits complex zonal heterogeneity. Specifically, the development of a tissue-engineered scaffold mimicking the aligned structure of native cartilage would be of great utility in terms of cartilage regeneration. Previously, we fabricated oriented PLGA/ACECM (natural, nanofibrous, articular cartilage ECM) composite scaffolds. In vitro, we found that the scaffolds not only guided seeded cells to proliferate in an aligned manner but also exhibited high biomechanical strength. To detect whether oriented cartilage regeneration was possible in vivo, we used mesenchymal stem cell (MSC)/scaffold constructs to repair cartilage defects. The results showed that cartilage defects could be completely regenerated. Histologically, these became filled with hyaline cartilage and subchondral bone. Moreover, the aligned structure of cartilage was regenerated and was similar to that of native tissue. In conclusion, the MSC/scaffold constructs enhanced the structure-specific regeneration of hyaline cartilage in a rabbit model and may be a promising treatment strategy for the repair of human cartilage defects. PMID:29666653

Lithographically Defined Three-dimensional Pore-patterned Carbon with Nitrogen Doping for High-Performance Ultrathin Supercapacitor Applications

PubMed Central

Kang, Da-Young; Moon, Jun Hyuk

2014-01-01

Supercapacitors that exhibit long cycle lives and fast charge/discharge rates are a promising energy-storage technology for next-generation mobile or wearable electronic systems. A great challenge facing the fabrication of ultrathin supercapacitor components, specifically their porous electrodes, is whether such components can be integrated with the fabrication of electronic devices, i.e., semiconductor fabrication processes. Here, we introduce the lithographic fabrication of micrometre-thick, submicrometre-pore-patterned carbon for supercapacitor electrodes. The pore patterns designed by multi-beam interference lithography and direct carbonisation of the photoresist pattern produced pore-patterned carbon films. A facile doping process was subsequently employed to introduce nitrogen atoms into the carbon, which was intended to further enhance the carbon's capacitive properties. Specifically, during these fabrication steps, we developed an approach that uses a supporting shell on the surface of the pore patterns to maintain their structural integrity. The nitrogen-doped, pore-patterned carbon electrodes exhibited an areal specific capacitance of 32.7 mF/cm2 at 0.5 mA/cm2 when used as supercapacitor electrodes, which is approximately 20 times greater than that of commercially available MWCNT films measured under the same conditions. PMID:24953307

Polypyrrole-encapsulated vanadium pentoxide nanowires on a conductive substrate for electrode in aqueous rechargeable lithium battery.

PubMed

Liang, Chaowei; Fang, Dong; Cao, Yunhe; Li, Guangzhong; Luo, Zhiping; Zhou, Qunhua; Xiong, Chuanxi; Xu, Weilin

2015-02-01

Precursors of ammonium vanadium bronze (NH4V4O10) nanowires assembled on a conductive substrate were prepared by a hydrothermal method. After calcination at 360°C, the NH4V4O10 precursor transformed to vanadium pentoxide (V2O5) nanowires, which presented a high initial capacity of 135.0mA h g(-1) at a current density of 50mA g(-1) in 5M LiNO3 aqueous solution; while the specific capacity faded quickly over 50 cycles. By coating the surface of V2O5 nanowires with water-insoluble polypyrrole (PPy), the formed nanocomposite electrode exhibited a specific discharge capacity of 89.9mA h g(-1) at 50mA g(-1) (after 100 cycles). A V2O5@PPy //LiMn2O4 rechargeable lithium battery exhibited an initial discharge capacity of 95.2mA h g(-1); and after 100 cycles, a specific discharge capacity of 81.5mA h g(-1) could retain at 100mA g(-1). Copyright © 2014 Elsevier Inc. All rights reserved.

Mesenchymal Stem Cells in Oriented PLGA/ACECM Composite Scaffolds Enhance Structure-Specific Regeneration of Hyaline Cartilage in a Rabbit Model.

PubMed

Guo, Weimin; Zheng, Xifu; Zhang, Weiguo; Chen, Mingxue; Wang, Zhenyong; Hao, Chunxiang; Huang, Jingxiang; Yuan, Zhiguo; Zhang, Yu; Wang, Mingjie; Peng, Jiang; Wang, Aiyuan; Wang, Yu; Sui, Xiang; Xu, Wenjing; Liu, Shuyun; Lu, Shibi; Guo, Quanyi

2018-01-01

Articular cartilage lacks a blood supply and nerves. Hence, articular cartilage regeneration remains a major challenge in orthopedics. Decellularized extracellular matrix- (ECM-) based strategies have recently received particular attention. The structure of native cartilage exhibits complex zonal heterogeneity. Specifically, the development of a tissue-engineered scaffold mimicking the aligned structure of native cartilage would be of great utility in terms of cartilage regeneration. Previously, we fabricated oriented PLGA/ACECM (natural, nanofibrous, articular cartilage ECM) composite scaffolds. In vitro, we found that the scaffolds not only guided seeded cells to proliferate in an aligned manner but also exhibited high biomechanical strength. To detect whether oriented cartilage regeneration was possible in vivo, we used mesenchymal stem cell (MSC)/scaffold constructs to repair cartilage defects. The results showed that cartilage defects could be completely regenerated. Histologically, these became filled with hyaline cartilage and subchondral bone. Moreover, the aligned structure of cartilage was regenerated and was similar to that of native tissue. In conclusion, the MSC/scaffold constructs enhanced the structure-specific regeneration of hyaline cartilage in a rabbit model and may be a promising treatment strategy for the repair of human cartilage defects.

A novel protein tyrosine phosphatase like phytase from Lactobacillus fermentum NKN51: Cloning, characterization and application in mineral release for food technology applications.

PubMed

Sharma, Rekha; Kumar, Piyush; Kaushal, Vandana; Das, Rahul; Kumar Navani, Naveen

2018-02-01

A novel protein tyrosine phosphatase like phytase (PTPLP), designated as PhyLf from probiotic bacterium Lactobacillus fermentum NKN51 was identified, cloned, expressed and characterized. The recombinant PhyLf showed specific activity of 174.5 U/mg. PhyLf exhibited strict specificity towards phytate and optimum temperature at 60 °C, pH 5.0 and ionic strength of 100 mM. K m and K cat of PhyLf for phytate were 0.773 mM and 84.31 s -1 , respectively. PhyLf exhibited high resistance against oxidative inactivation. PhyLf shares no homology, sans the active site with reported PTLPs, warranting classification as a new subclass. Dephytinization of durum wheat and finger millet under in vitro gastrointestinal conditions using PhyLf enhanced the bioaccessibility of mineral ions. Probiotic origin, phytate specificity, resistance to oxidative environment and gastric milieu coupled with ability to release micronutrients are unique properties of PhyLf which present a strong case for its use in ameliorating nutritional value of cereals and animal feed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthesis of carbon core–shell pore structures and their performance as supercapacitors

DOE PAGES

Ariyanto, Teguh; Dyatkin, Boris; Zhang, Gui-Rong; ...

2015-07-15

High-power supercapacitors require excellent electrolyte mobility within the pore network and high electrical conductivity for maximum capacitance and efficiency. Achieving high power typically requires sacrificing energy densities, as the latter demands a high specific surface area and narrow porosity that impedes ion transport. Here, we present a novel solution for this optimization problem: a nanostructured core–shell carbonaceous material that exhibits a microporous carbon core surrounded by a mesoporous, graphitic shell. The tunable synthesis parameters yielded a structure that features either a sharp or a gradual transition between the core and shell sections. Electrochemical supercapacitor testing using organic electrolyte revealed thatmore » these novel core–shell materials outperform carbons with homogeneous pore structures. The hybrid core–shell materials showed a combination of good capacitance retention, typical for the carbon present in the shell and high specific capacitance, typical for the core material. These materials achieved power densities in excess of 40 kW kg -1 at energy densities reaching 27 Wh kg -1.« less

Design of a Highly Specific And Noninvasive Biosensor Suitable for Real-Time in Vivo Imaging of Mercury (II) Uptake

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

Chapleau, R.R.; Blomberg, R.; Ford, P.C.

2009-05-12

Mercury is a ubiquitous pollutant that when absorbed is extremely toxic to a wide variety of biochemical processes. Mercury (II) is a strong, invisible poison that is rapidly absorbed by tissues of the intestinal tract, kidneys, and liver upon ingestion. In this study, a novel fluorescence-based biosensor is presented that allows for the direct monitoring of the uptake and distribution of the metal under noninvasive in vivo conditions. With the introduction of a cysteine residue at position 205, located in close proximity to the chromophore, the green fluorescent protein (GFP) from Aequorea victoria was converted into a highly specific biosensormore » for this metal ion. The mutant protein exhibits a dramatic absorbance and fluorescence change upon mercuration at neutral pH. Absorbance and fluorescence properties with respect to the metal concentration exhibit sigmoidal binding behavior with a detection limit in the low nanomolar range. Time-resolved binding studies indicate rapid subsecond binding of the metal to the protein. The crystal structures obtained of mutant eGFP205C indicate a possible access route of the metal into the core of the protein. To our knowledge, this engineered protein is a first example of a biosensor that allows for noninvasive and real-time imaging of mercury uptake in a living cell. A major advantage is that its expression can be genetically controlled in many organisms to enable unprecedented studies of tissue specific mercury uptake.« less

Adipose-specific ablation of Nrf2 transiently delayed high-fat diet-induced obesity by altering glucose, lipid and energy metabolism of male mice.

PubMed

Zhang, Le; Dasuri, Kalavathi; Fernandez-Kim, Sun-Ok; Bruce-Keller, Annadora J; Keller, Jeffrey N

2016-01-01

Nuclear factor E2-related factor 2 (NRF2) is a well-known master controller of the cellular adaptive antioxidant and detoxification response. Recent studies demonstrated altered glucose, lipid and energy metabolism in mice with a global Nrf2 knockout. In the present study, we aim to determine the effects of an adipose-specific ablation of Nrf2 (ASAN) on diet-induced obesity (DIO) in male mice. The 6-week-old adipose-specific Nrf2 knockout (NK) and its Nrf2 control (NC) mice were fed with either control diet (CD) or high-fat diet (HFD) for 14 weeks. NK mice exhibited transiently delayed body weight (BW) growth from week 5 to week 11 of HFD feeding, higher daily physical activity levels and preferential use of fat over carbohydrates as a source of energy at week 8 of the CD-feeding period. After 14 weeks of feeding, NK mice showed comparable results with NC mice with respect to the overall BW and body fat content, but exhibited reduced blood glucose, reduced number but increased size of adipocytes, accompanied with elevated expression of many genes and proteins in the visceral fat related to glucose, lipid and energy metabolism (e.g. Fgf21 , Pgc1a ). These results indicated that NRF2 is an important mediator for glucose, lipid and energy metabolism in adipose tissue, and ASAN could have beneficial effect for prevention of DIO during the early development of mice.

Selective Transformation of β-Lactam Antibiotics by Peroxymonosulfate: Reaction Kinetics and Nonradical Mechanism.

PubMed

Chen, Jiabin; Fang, Cong; Xia, Wenjun; Huang, Tianyin; Huang, Ching-Hua

2018-02-06

While the β-lactam antibiotics are known to be susceptible to oxidative degradation by sulfate radical (SO 4 •- ), here we report that peroxymonosulfate (PMS) exhibits specific high reactivity toward β-lactam antibiotics without SO 4 •- generation for the first time. Apparent second-order reaction constants (k 2,app ) were determined for the reaction of PMS with three penicillins, five cephalosporins, two carbapenems, and several structurally related chemicals. The pH-dependency of k 2,app could be well modeled based on species-specific reactions. On the basis of reaction kinetics, stoichiometry, and structure-activity assessment, the thioether sulfur, on the six- or five-membered rings (penicillins and cephalosporins) and the side chain (carbapenems), was the main reaction site for PMS oxidation. Cephalosporins were more reactive toward PMS than penicillins and carbapenems, and the presence of a phenylglycine side chain significantly enhanced cephalosporins' reactivity toward PMS. Product analysis indicated oxidation of β-lactam antibiotics to two stereoisomeric sulfoxides. A radical scavenging study and electron paramagnetic resonance (EPR) technique confirmed lack of involvement of radical species (e.g., SO 4 •- ). Thus, the PMS-induced oxidation of β-lactam antibiotics was proposed to proceed through a nonradical mechanism involving direct two-electron transfer along with the heterolytic cleavage of the PMS peroxide bond. The new findings of this study are important for elimination of β-lactam antibiotic contamination, because PMS exhibits specific high reactivity and suffers less interference from the water matrix than the radical process.

Rational Synthesis of Branched CoMoO4@CoNiO2 Core/Shell Nanowire Arrays for All-Solid-State Supercapacitors with Improved Performance.

PubMed

Ai, Yuanfei; Geng, Xuewen; Lou, Zheng; Wang, Zhiming M; Shen, Guozhen

2015-11-04

Effectively composite materials with optimized structures exhibited promising potential in continuing improving the electrochemical performances of supercapacitors in the past few years. Here, we proposed a rational design of branched CoMoO4@CoNiO2 core/shell nanowire arrays on Ni foam by two steps of hydrothermal processing. Owing to the high activity of the scaffold-like CoMoO4 nanowires and the well-defined CoNiO2 nanoneedles, the three-dimensional (3D) electrode architectures achieved remarkable electrochemical performances with high areal specific capacitance (5.31 F/cm(2) at 5 mA/cm(2)) and superior cycling stability(159% of the original specific capacitance, i.e., 95.7% of the maximum retained after 5000 cycles at 30 mA/cm(2)). The all-solid-state asymmetric supercapacitors composed of such electrode and activated carbon (AC) exhibited an areal specific capacitance of 1.54 F/cm(2) at 10 mA/cm(2) and a rate capability (59.75 Wh/kg at a 1464 W/kg) comparable with Li-ion batteries. It also showed an excellent cycling stability with no capacitance attenuation after 50000 cycles at 100 mA/cm(2). After rapid charging (1 s), such supercapacitors in series could lighten a red LED for a long time and drive a mini motor effectively, demonstrating advances in energy storage, scalable integrated applications, and promising commercial potential.

Species-Specific Transmission of Novel Picornaviruses in Lemurs

PubMed Central

Lim, Efrem S.; Deem, Sharon L.; Porton, Ingrid J.; Cao, Song

2015-01-01

ABSTRACT The roles of host genetics versus exposure and contact frequency in driving cross-species transmission remain the subject of debate. Here, we used a multitaxon lemur collection at the Saint Louis Zoo in the United States as a model to gain insight into viral transmission in a setting of high interspecies contact. Lemurs are a diverse and understudied group of primates that are highly endangered. The speciation of lemurs, which are endemic to the island of Madagascar, occurred in geographic isolation apart from that of continental African primates. Although evidence of endogenized viruses in lemur genomes exists, no exogenous viruses of lemurs have been described to date. Here we identified two novel picornaviruses in fecal specimens of ring-tailed lemurs (Lemur catta) and black-and-white ruffed lemurs (Varecia variegata). We found that the viruses were transmitted in a species-specific manner (lesavirus 1 was detected only in ring-tailed lemurs, while lesavirus 2 was detected only in black-and-white ruffed lemurs). Longitudinal sampling over a 1-year interval demonstrated ongoing infection in the collection. This was supported by evidence of viral clearance in some animals and new infections in previously uninfected animals, including a set of newly born triplets that acquired the infection. While the two virus strains were found to be cocirculating in a mixed-species exhibit of ring-tailed lemurs, black-and-white ruffed lemurs, and black lemurs, there was no evidence of cross-species transmission. This suggests that despite high-intensity contact, host species barriers can prevent cross-species transmissions of these viruses. IMPORTANCE Up to 75% of emerging infectious diseases in humans today are the result of zoonotic transmission. However, a challenge in understanding transmission dynamics has been the limited models of cross-species transmission. Zoos provide a unique opportunity to explore parameters defining viral transmission. We demonstrated that ongoing virus transmission in a mixed lemur species exhibit was species specific. This suggests that despite high contact intensity, host species barriers contribute to protection from cross-species transmission of these viruses. While the combinations of species might differ, most zoological parks worldwide commonly feature mixed-species exhibits. Collectively, this report demonstrates a widely applicable approach toward understanding infectious disease transmission. PMID:25631076

From rice bran to high energy density supercapacitors: a new route to control porous structure of 3D carbon.

PubMed

Hou, Jianhua; Cao, Chuanbao; Ma, Xilan; Idrees, Faryal; Xu, Bin; Hao, Xin; Lin, Wei

2014-12-01

Controlled micro/mesopores interconnected structures of three-dimensional (3D) carbon with high specific surface areas (SSA) are successfully prepared by carbonization and activation of biomass (raw rice brans) through KOH. The highest SSA of 2475 m(2) g(-1) with optimized pore volume of 1.21 cm(3) g(-1) (40% for mesopores) is achieved for KOH/RBC = 4 mass ratio, than others. The as-prepared 3D porous carbon-based electrode materials for supercapacitors exhibit high specific capacitance specifically at large current densities of 10 A g(-1) and 100 A g(-1) i.e., 265 F g(-1) and 182 F g(-1) in 6 M KOH electrolyte, respectively. Moreover, a high power density ca. 1223 W kg(-1) (550 W L(-1)) and energy density 70 W h kg(-1) (32 W h L(-1)) are achieved on the base of active material loading (~10 mg cm(2)) in the ionic liquid. The findings can open a new avenue to use abundant agricultural by-products as ideal materials with promising applications in high-performance energy-storage devices.

From Rice Bran to High Energy Density Supercapacitors: A New Route to Control Porous Structure of 3D Carbon

NASA Astrophysics Data System (ADS)

Hou, Jianhua; Cao, Chuanbao; Ma, Xilan; Idrees, Faryal; Xu, Bin; Hao, Xin; Lin, Wei

2014-12-01

Controlled micro/mesopores interconnected structures of three-dimensional (3D) carbon with high specific surface areas (SSA) are successfully prepared by carbonization and activation of biomass (raw rice brans) through KOH. The highest SSA of 2475 m2 g-1 with optimized pore volume of 1.21 cm3 g-1 (40% for mesopores) is achieved for KOH/RBC = 4 mass ratio, than others. The as-prepared 3D porous carbon-based electrode materials for supercapacitors exhibit high specific capacitance specifically at large current densities of 10 A g-1 and 100 A g-1 i.e., 265 F g-1 and 182 F g-1 in 6 M KOH electrolyte, respectively. Moreover, a high power density ca. 1223 W kg-1 (550 W L-1) and energy density 70 W h kg-1 (32 W h L-1) are achieved on the base of active material loading (~10 mg cm2) in the ionic liquid. The findings can open a new avenue to use abundant agricultural by-products as ideal materials with promising applications in high-performance energy-storage devices.

From Rice Bran to High Energy Density Supercapacitors: A New Route to Control Porous Structure of 3D Carbon

PubMed Central

Hou, Jianhua; Cao, Chuanbao; Ma, Xilan; Idrees, Faryal; Xu, Bin; Hao, Xin; Lin, Wei

2014-01-01

Controlled micro/mesopores interconnected structures of three-dimensional (3D) carbon with high specific surface areas (SSA) are successfully prepared by carbonization and activation of biomass (raw rice brans) through KOH. The highest SSA of 2475 m2 g−1 with optimized pore volume of 1.21 cm3 g−1 (40% for mesopores) is achieved for KOH/RBC = 4 mass ratio, than others. The as-prepared 3D porous carbon-based electrode materials for supercapacitors exhibit high specific capacitance specifically at large current densities of 10 A g−1 and 100 A g−1 i.e., 265 F g−1 and 182 F g−1 in 6 M KOH electrolyte, respectively. Moreover, a high power density ca. 1223 W kg−1 (550 W L−1) and energy density 70 W h kg−1 (32 W h L−1) are achieved on the base of active material loading (~10 mg cm2) in the ionic liquid. The findings can open a new avenue to use abundant agricultural by-products as ideal materials with promising applications in high-performance energy-storage devices. PMID:25434348

A folate-integrated magnetic polymer micelle for MRI and dual targeted drug delivery

NASA Astrophysics Data System (ADS)

Ao, Lijiao; Wang, Bi; Liu, Peng; Huang, Liang; Yue, Caixia; Gao, Duyang; Wu, Chunlei; Su, Wu

2014-08-01

This paper devotes a novel micellar structure for cancer theranostics by incorporating magnetic and therapeutic functionalities into a natural sourced targeting polymer vehicle. Heparin-folic acid micelles taking advantage of both excellent loading capability and cancer targeting ability have been employed to simultaneously incorporate superparamagnetic iron oxide nanoparticles (SPIONs) and doxorubicin through an ultrasonication-assisted microemulsion method. In this system, folic acids not only take the responsibility of micelle construction, but also facilitate cellular uptake due to their specific reorganization by MCF-7 cells over-expressing folate receptors. The obtained micelles exhibit good colloidal stability, a high magnetic content, considerable drug loading and sustained in vitro drug release. These clustered SPIONs exhibited high r2 relaxivity (243.65 mM-1 s-1) and further served as efficient probes for MR imaging. Notably, the transport efficiency of these micelles could be significantly improved under an external magnetic field, owing to their quick magnetic response. As a result, the as-proposed micelle shows great potential in multimodal theranostics, including active targeting, MRI diagnosis and drug delivery.This paper devotes a novel micellar structure for cancer theranostics by incorporating magnetic and therapeutic functionalities into a natural sourced targeting polymer vehicle. Heparin-folic acid micelles taking advantage of both excellent loading capability and cancer targeting ability have been employed to simultaneously incorporate superparamagnetic iron oxide nanoparticles (SPIONs) and doxorubicin through an ultrasonication-assisted microemulsion method. In this system, folic acids not only take the responsibility of micelle construction, but also facilitate cellular uptake due to their specific reorganization by MCF-7 cells over-expressing folate receptors. The obtained micelles exhibit good colloidal stability, a high magnetic content, considerable drug loading and sustained in vitro drug release. These clustered SPIONs exhibited high r2 relaxivity (243.65 mM-1 s-1) and further served as efficient probes for MR imaging. Notably, the transport efficiency of these micelles could be significantly improved under an external magnetic field, owing to their quick magnetic response. As a result, the as-proposed micelle shows great potential in multimodal theranostics, including active targeting, MRI diagnosis and drug delivery. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr02484b

Nanocolloids in Natural Water: Isolation, Characterization, and Toxicity.

PubMed

Ouyang, Shaohu; Hu, Xiangang; Zhou, Qixing; Li, Xiaokang; Miao, Xinyu; Zhou, Ruiren

2018-04-17

Nanocolloids are widespread in natural water systems, but their characterization and ecological risks are largely unknown. Herein, tangential flow ultrafiltration (TFU) was used to separate and concentrate nanocolloids from surface waters. Unexpectedly, nanocolloids were present in high concentrations ranging from 3.7 to 7.2 mg/L in the surface waters of the Harihe River in Tianjin City, China. Most of the nanocolloids were 10-40 nm in size, contained various trace metals and polycyclic aromatic hydrocarbons, and exhibited fluorescence properties. Envelopment effects and aggregation of Chlorella vulgaris in the presence of nanocolloids were observed. Nanocolloids entered cells and nanocolloid-exposed cells exhibited stronger plasmolysis, chloroplast damage and more starch grains than the control cells. Moreover, nanocolloids inhibited the cell growth, promoted reactive oxygen species (ROS), reduce the chlorophyll a content and increased the cell permeability. The genotoxicity of nanocolloids was also observed. The metabolomics analysis revealed a significant ( p < 0.05) downregulation of amino acids and upregulation of fatty acids contributing to ROS increase, chlorophyll a decrease and plasmolysis. The present work reveals that nanocolloids, which are different from specific, engineered nanoparticles (e.g., Ag nanoparticles), are present at high concentrations, exhibit an obvious toxicity in environments, and deserve more attention in the future.

Novel hydrophobic PDVB/R-SiO2 for adsorption of volatile organic compounds from highly humid gas stream.

PubMed

Lu, Han-feng; Cao, Jie-jing; Zhou, Ying; Zhan, De-li; Chen, Yin-fei

2013-11-15

A novel organic-inorganic hydrophobic polydivinylbenzene-silica adsorbent (PDVB/R-SiO2) was successfully prepared by introducing a specific amount of divinylbenzene and solvent (i.e., tetrahydrofuran) to SiO2pores and initiating polymerization under solvothermal conditions. New smaller structures and surface areas were formed in the SiO2 pores. The PDVB/R-SiO2-0.5 samples exhibited a bimodal pore size distribution with both SiO2 micropores/mesopores (0.5-2.0 nm) and mesopores (2.0-5.0 nm). The surface areas increased from 116 m(2)/g (SiO2) to 246 m(2)/g. The breakthrough curves of toluene adsorption indicated that the amount adsorbed on PDVB/R-SiO2-0.5 was 12 times higher than that on SiO2. The highly humid environment exhibited no effect on adsorption because the surface of PDVB was functionalized. The adsorbed toluene was easily desorbed in hot N2 stream at 100 °C. After 10 adsorption-desorption cycles, PDVB/R-SiO2-0.5 continued exhibiting excellent adsorption, indicating superior structural and regeneration abilities. Copyright © 2013 Elsevier B.V. All rights reserved.

One-step hydrothermal synthesis of hexangular starfruit-like vanadium oxide for high power aqueous supercapacitors

NASA Astrophysics Data System (ADS)

Shao, Jie; Li, Xinyong; Qu, Qunting; Zheng, Honghe

2012-12-01

Homogenous hexangular starfruit-like vanadium oxide was prepared for the first time by a one-step hydrothermal method. The assembly process of hexangular starfruit-like structure was observed from TEM images. The electrochemical performance of starfruit-like vanadium oxide was examined by cyclic voltammetry and galvanostatic charge/discharge. The obtained starfruit-like vanadium oxide exhibits a high power capability (19 Wh kg-1 at the specific power of 3.4 kW kg-1) and good cycling stability for supercapacitors application.

Carbonized-leaf Membrane with Anisotropic Surfaces for Sodium-ion Battery.

PubMed

Li, Hongbian; Shen, Fei; Luo, Wei; Dai, Jiaqi; Han, Xiaogang; Chen, Yanan; Yao, Yonggang; Zhu, Hongli; Fu, Kun; Hitz, Emily; Hu, Liangbing

2016-01-27

A simple one-step thermal pyrolysis route has been developed to prepare carbon membrane from a natural leaf. The carbonized leaf membrane possesses anisotropic surfaces and internal hierarchical porosity, exhibiting a high specific capacity of 360 mAh/g and a high initial Coulombic efficiency of 74.8% as a binder-free, current-collector-free anode for rechargeable sodium ion batteries. Moreover, large-area carbon membranes with low contact resistance are fabricated by simply stacking and carbonizing leaves, a promising strategy toward large-scale sodium-ion battery developments.

On Controlling the Hydrophobicity of Nanostructured Zinc-Oxide Layers Grown by Pulsed Electrodeposition

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

Klochko, N. P., E-mail: klochko-np@mail.ru; Klepikova, K. S.; Kopach, V. R.

The possibility of fabricating highly hydrophobic nanostructured zinc-oxide layers by the inexpensive method of pulsed electrodeposition from aqueous solutions without water-repellent coatings, adapted for large-scale production, is shown. The conditions of the deposition of highly hydrophobic nanostructured zinc-oxide layers exhibiting the “rose-petal” effect with specific morphology, optical properties, crystal structure and texture are determined. The grown ZnO nanostructures are promising for micro- and nanoelectronics as an adaptive material able to reversibly transform to the hydrophilic state upon exposure to ultraviolet radiation.

Polythiophene nanocomposites as high performance electrode material for supercapacitor application

NASA Astrophysics Data System (ADS)

Vijeth, H.; Niranjana, M.; Yesappa, L.; Ashokkumar, S. P.; Devendrappa, H.

2018-04-01

A polythiophene-aluminium oxide nanocomposite is prepared by in situ chemical polymerisation in presence of anionic surfactant camphor sulfonic acid (CSA). The characterisation of nano composite was done by X-ray Diffraction (XRD), surface morphology was studied using Atomic Force Microscopy (AFM). The electrochemical performance is evaluated using cyclic voltammetry in 1M H2SO4. As an electroactive material, it exhibits high specific capacitance of 654.5 and 757 F/g for PTH and PTHA nanocomposites at scan rate of 30mV s-1 respectively.

Three-dimensional interconnected network of graphene-wrapped porous silicon spheres: in situ magnesiothermic-reduction synthesis and enhanced lithium-storage capabilities.

PubMed

Wu, Ping; Wang, Hui; Tang, Yawen; Zhou, Yiming; Lu, Tianhong

2014-03-12

A novel type of 3D porous Si-G micro/nanostructure (i.e., 3D interconnected network of graphene-wrapped porous silicon spheres, Si@G network) was constructed through layer-by-layer assembly and subsequent in situ magnesiothermic-reduction methodology. Compared with bare Si spheres, the as-synthesized Si@G network exhibits markedly enhanced anodic performance in terms of specific capacity, cycling stability, and rate capability, making it an ideal anode candidate for high-energy, long-life, and high-power lithium-ion batteries.

Developing high throughput quantitative PCR assays for diagnosing Ikeda and other Theileria orientalis types common to New Zealand in bovine blood samples.

PubMed

Pulford, D J; Gias, E; Bueno, I M; McFadden, Amj

2016-01-01

To develop rapid, quantitative PCR (qPCR) assays using high resolution melt (HRM) analysis and type-specific TaqMan assays for identifying the prevalent types of Theileria orientalis found in New Zealand cattle; and to evaluate their analytical and diagnostic characteristics compared with other assays for T. orientalis. Nucleotide sequences aligned with T. orientalis Buffeli, Chitose and Ikeda types, obtained from DNA extracted from blood samples from infected cattle, were used to design HRM and type-specific probe-based qPCR assays. The three type-specific assays were also incorporated into a single-tube multiplex qPCR assay. These assays were validated using DNA extracted from blood samples from cattle in herds with or without clinical signs of T. orientalis infection, other veterinary laboratory samples, as well as plasmids containing T. orientalis type-specific sequences. Diagnostic specificity (DSp) and sensitivity (DSe) estimates for the qPCR assays were compared to blood smear piroplasm results, and other PCR assays for T. orientalis. Copy number estimates of Ikeda DNA in blood were determined from cattle exhibiting anaemia using the Ikeda-specific qPCR assay. The T. orientalis type-specific and the HRM qPCR assays displayed 100% analytical specificity. The Ikeda-specific qPCR assay exhibited linearity (R(2) = 0.997) with an efficiency of 94.3%. Intra-assay CV were ≤0.08 and inter-assay CV were ≤0.095. For blood samples from cows with signs of infection with T. orientalis, the DSp and DSe of the multiplex probe qPCR assay were 93 and 96%, respectively compared with blood smears, and 97 and 100%, respectively compared with conventional PCR assays. For the Ikeda-specific qPCR assay, the number of positive samples (n=66) was slightly higher than a conventional PCR assay (n=64). The concentration of Ikeda genomes in blood samples from 41 dairy cows with signs of infection with T. orientalis ranged between 5.6 × 10(4) and 3.3 × 10(6) genomes per µL of blood. All qPCR assays had improved specificity and sensitivity over existing conventional PCR assays for diagnosis of T. orientalis Ikeda. The burden of Ikeda DNA in blood was demonstrated using an Ikeda-specific qPCR assay with titrated synthetic gene target. Adoption of high-throughput DNA extraction and qPCR reduced T. orientalis and Ikeda diagnosis times. The Ikeda-specific qPCR assay provides a specific diagnosis for Ikeda in animals with signs of infection with T. orientalis and can be used to monitor the parasite load of Ikeda in blood.

Follitropin receptors in rat testis. Characterization with enzymatically 125I-labeled human follitropin.

PubMed

Ketelslegers, J M; Catt, K J

1978-07-03

The interaction between enzymatically radioiodinated human follitropin and the follitropin receptors in testis homogenate was investigated in immature and adult rats. The 125I-labeled human follitropin exhibited high binding activity with specific binding of up to 17% in the presence of an excess of testis homogenate. Approx. 50% of the bound hormone could be eluted at pH 5, and the receptor purified tracer exhibited a 3.6-fold increase in binding activity when compared with the original tracer preparation. Quantitative analysis of equilibrium binding data was performed with corrections for the measured specific activity and maximum binding activity of the tracer hormone. The equilibrium association constants (Ka) determined 24 degrees C were not significantly different in immature and adult rat testis, and the mean value for Ka was 3.9 . 10(9) M-1. At 37 degrees C, the Ka value obtained using immature rat testis was 1.3 . 10(10) M-1. The association of 125I-labeled human follitropin with immature rat testis homogenate was time and temperature dependent. In the presence of an excess of unlabeled hormone, 30--60% of the preformed hormone . receptor complex was dissociated after 24 h incubation. A specific and sensitive radioligand-receptor assay for follitropin was developed using immature rat testis homogenate. The minimum detectable dose of purified human follitropin was 0.6 ng, and human urinary and pituitary follitropin, ovine follitropin and pregnant mare serum gonadotropin reacted in the assay with equivalent slopes. The potencies of highly purified pregnent mare serum gonadotropin and highly purified human follitropin were similar in the radioligand-receptor assay, consistent with the follitropin bioactivity of the equine gonadotropin.

Self responses along cingulate cortex reveal quantitative neural phenotype for high functioning autism

PubMed Central

Chiu, Pearl H.; Kayali, M. Amin; Kishida, Kenneth T.; Tomlin, Damon; Klinger, Laura G.; Klinger, Mark R.; Montague, P. Read

2014-01-01

Summary Attributing behavioral outcomes correctly to oneself or to other agents is essential for all productive social exchange. We approach this issue in high-functioning males with autism spectrum disorder (ASD) using two separate fMRI paradigms. First, using a visual imagery task, we extract a basis set for responses along the cingulate cortex of control subjects that reveals an agent-specific eigenvector (self eigenmode) associated with imagining oneself executing a specific motor act. Second, we show that the same self eigenmode arises during one's own decision (the self phase) in an interpersonal exchange game (iterated trust game). Third, using this exchange game, we show that ASD males exhibit a severely diminished self eigenmode when playing the game with a human partner. This diminished response covaries parametrically with their behaviorally assessed symptom severity suggesting its value as an objective endophenotype. These findings may provide a quantitative assessment tool for high functioning ASD. PMID:18255038

Monochromatic ocular wave aberrations in young monkeys

PubMed Central

Ramamirtham, Ramkumar; Kee, Chea-su; Hung, Li-Fang; Qiao-Grider, Ying; Roorda, Austin; Smith, Earl L.

2006-01-01

High-order monochromatic aberrations could potentially influence vision-dependent refractive development in a variety of ways. As a first step in understanding the effects of wave aberration on refractive development, we characterized the maturational changes that take place in the high-order aberrations of infant rhesus monkey eyes. Specifically, we compared the monochromatic wave aberrations of infant and adolescent animals and measured the longitudinal changes in the high-order aberrations of infant monkeys during the early period when emmetropization takes place. Our main findings were that (1) adolescent monkey eyes have excellent optical quality, exhibiting total RMS errors that were slightly better than those for adult human eyes that have the same numerical aperture and (2) shortly after birth, infant rhesus monkeys exhibited relatively larger magnitudes of high-order aberrations predominately spherical aberration, coma, and trefoil, which decreased rapidly to assume adolescent values by about 200 days of age. The results demonstrate that rhesus monkey eyes are a good model for studying the contribution of individual ocular components to the eye’s overall aberration structure, the mechanisms responsible for the improvements in optical quality that occur during early ocular development, and the effects of high-order aberrations on ocular growth and emmetropization. PMID:16750549

The hybrid nanostructure of MnCo2O4.5 nanoneedle/carbon aerogel for symmetric supercapacitors with high energy density

NASA Astrophysics Data System (ADS)

Hao, Pin; Zhao, Zhenhuan; Li, Liyi; Tuan, Chia-Chi; Li, Haidong; Sang, Yuanhua; Jiang, Huaidong; Wong, C. P.; Liu, Hong

2015-08-01

Current applications of carbon-based supercapacitors are limited by their low energy density. One promising strategy to enhance the energy density is to couple metal oxides with carbon materials. In this study, a porous MnCo2O4.5 nanoneedle/carbon aerogel hybrid nanostructure was synthesized by assembling MnCo2O4.5 nanoneedle arrays on the surface of channel walls of hierarchical porous carbon aerogels derived from chitosan for the supercapacitor application. The synthetic process of the hybrid nanostructure involves two steps, i.e. the growth of Mn-Co precursors on carbon aerogel by a hydrothermal process and the conversion of the precursor into MnCo2O4.5 nanoneedles by calcination. The carbon aerogel exhibits a high electrical conductivity, high specific surface area and porous structure, ensuring high electrochemical performance of the hybrid nanostructure when coupled with the porous MnCo2O4.5 nanoneedles. The symmetric supercapacitor using the MnCo2O4.5 nanoneedle/carbon aerogel hybrid nanostructure as the active electrode material exhibits a high energy density of about 84.3 Wh kg-1 at a power density of 600 W kg-1. The voltage window is as high as 1.5 V in neutral aqueous electrolytes. Due to the unique nanostructure of the electrodes, the capacitance retention reaches 86% over 5000 cycles.Current applications of carbon-based supercapacitors are limited by their low energy density. One promising strategy to enhance the energy density is to couple metal oxides with carbon materials. In this study, a porous MnCo2O4.5 nanoneedle/carbon aerogel hybrid nanostructure was synthesized by assembling MnCo2O4.5 nanoneedle arrays on the surface of channel walls of hierarchical porous carbon aerogels derived from chitosan for the supercapacitor application. The synthetic process of the hybrid nanostructure involves two steps, i.e. the growth of Mn-Co precursors on carbon aerogel by a hydrothermal process and the conversion of the precursor into MnCo2O4.5 nanoneedles by calcination. The carbon aerogel exhibits a high electrical conductivity, high specific surface area and porous structure, ensuring high electrochemical performance of the hybrid nanostructure when coupled with the porous MnCo2O4.5 nanoneedles. The symmetric supercapacitor using the MnCo2O4.5 nanoneedle/carbon aerogel hybrid nanostructure as the active electrode material exhibits a high energy density of about 84.3 Wh kg-1 at a power density of 600 W kg-1. The voltage window is as high as 1.5 V in neutral aqueous electrolytes. Due to the unique nanostructure of the electrodes, the capacitance retention reaches 86% over 5000 cycles. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr04421a

Anthropometric characteristics, physical fitness and motor coordination of 9 to 11 year old children participating in a wide range of sports.

PubMed

Opstoel, Katrijn; Pion, Johan; Elferink-Gemser, Marije; Hartman, Esther; Willemse, Bas; Philippaerts, Renaat; Visscher, Chris; Lenoir, Matthieu

2015-01-01

The aim of this study was to investigate to what extent 9 to 11 year old children participating in a specific sport already exhibit a specific anthropometric, physical fitness and motor coordination profile, in line with the requirements of that particular sport. In addition, the profiles in children with a different training volume were compared and possible differences in training hours per week between children from a low, moderate, and high level of physical fitness and motor coordination were investigated. Data of 620 children, 347 boys and 273 girls, who participated in the Flemish Sports Compass were used. Only the primary sport of each child was considered and six groups of sports (Ball sports, Dance, Gymnastics, Martial arts, Racquet sports and Swimming) were formed based on common characteristics. Measurements consisted of 17 tests. Independent T-tests and Mann-Whitney U-tests revealed few differences between the groups of sports and the discriminant analyses with the moderate and low active group did not show any significant results (p > .05). However, when discriminating among the high active children, a 85.2 % correct classification between six groups of sports was found (Wilks' Λ = .137 and p < .001). Finally, children performing under average on the tests spent significantly fewer hours in sport per week (2.50 ± 1.84 hours) compared to the children performing best (3.25 ± 2.60 hours) (p = .016) and the children performing above average (2.90 ± 1.96 hours) (p = .029) on physical fitness and motor coordination. The study showed that in general, children at a young age do not exhibit sport-specific characteristics, except in children with a high training volume. It is possible that on the one hand, children have not spent enough time yet in their sport to develop sport-specific qualities. On the other hand, it could be possible that they do not take individual qualities into account when choosing a sport.

Few layered vanadyl phosphate nano sheets-MWCNT hybrid as an electrode material for supercapacitor application

NASA Astrophysics Data System (ADS)

Dutta, Shibsankar; De, Sukanta

2016-05-01

It have been already seen that 2-dimensional nano materials are the suitable choice for the supercapacitor application due to their large specific surface area, electrochemical active sites, micromechanical flexibility, expedite ion migration channel properties. Free standing hybrid films of functionalized MWCNT (- COOH group) and α-Vanadyl phosphates (VOPO42H2O) are prepared by vacuum filtering. The surface morphology and microstructure of the samples are studied by transmission electron microscope, field emission scanning electron microscope, XRD, Electrochemical properties of hybrid films have been investigated systematically in 1M Na2SO4 aqueous electrolyte. The hybrid material exhibits a high specific capacitance 236 F/g with high energy density of 65.6 Wh/Kg and a power density of 1476 W/Kg.

Thioflavin T as an efficient fluorescence sensor for selective recognition of RNA G-quadruplexes

NASA Astrophysics Data System (ADS)

Xu, Shujuan; Li, Qian; Xiang, Junfeng; Yang, Qianfan; Sun, Hongxia; Guan, Aijiao; Wang, Lixia; Liu, Yan; Yu, Lijia; Shi, Yunhua; Chen, Hongbo; Tang, Yalin

2016-04-01

RNA G-quadruplexes (G4s) play important roles in translational regulation, mRNA processing events and gene expression. Therefore, a fluorescent probe that is capable of efficiently recognizing RNA G-quadruplex structures among other RNA forms is highly desirable. In this study, a water-soluble fluorogenic dye (i.e., Thioflavin T (ThT)) was employed to recognize RNA G-quadruplex structures using UV-Vis absorption spectra, fluorescence spectra and emission lifetime experiments. By stacking on the G-tetrad, the ThT probe exhibited highly specific recognition of RNA G-quadruplex structures with striking fluorescence enhancement compared with other RNA forms. The specific binding demonstrates that ThT is an efficient fluorescence sensor that can distinguish G4 and non-G4 RNA structures.

High-Throughput Quantification of SH2 Domain-Phosphopeptide Interactions with Cellulose-Peptide Conjugate Microarrays.

PubMed

Engelmann, Brett W

2017-01-01

The Src Homology 2 (SH2) domain family primarily recognizes phosphorylated tyrosine (pY) containing peptide motifs. The relative affinity preferences among competing SH2 domains for phosphopeptide ligands define "specificity space," and underpins many functional pY mediated interactions within signaling networks. The degree of promiscuity exhibited and the dynamic range of affinities supported by individual domains or phosphopeptides is best resolved by a carefully executed and controlled quantitative high-throughput experiment. Here, I describe the fabrication and application of a cellulose-peptide conjugate microarray (CPCMA) platform to the quantitative analysis of SH2 domain specificity space. Included herein are instructions for optimal experimental design with special attention paid to common sources of systematic error, phosphopeptide SPOT synthesis, microarray fabrication, analyte titrations, data capture, and analysis.

3D architecture of a graphene/CoMoO(4) composite for asymmetric supercapacitors usable at various temperatures.

PubMed

Jiang, Yaru; Zheng, Xin; Yan, Xiaoqin; Li, Yong; Zhao, Xuan; Zhang, Yue

2017-05-01

Designing and optimizing the electrode materials and studying the electrochemical performance or cycle life of the supercapacitor under different working conditions are crucial to its practical application. Herein, we proposed a rational design of 3D-graphene/CoMoO 4 nanoplates by a facile two-step hydrothermal method. Owing to the high electron transfer rate of graphene and the high activity of the CoMoO 4 nanoplates, the three-dimensional electrode architectures achieved remarkable electrochemical performances with high areal specific capacitance (1255.24F/g at 1A/g) and superior cycling stability (91.3% of the original specific capacitance after 3000 cycles at 1A/g). The all-solid-state asymmetric supercapacitor composed of 3D-graphene/CoMoO 4 and activated carbon (AC) exhibited a specific capacitance of 109F/g at 0.2A/g and an excellent cycling stability with only 12.1% of the initial specific capacitance off after 3000 cycles at 2A/g. The effects of temperature and charge-discharge current densities on the charge storage capacity of the supercapacitor were also investigated in detail for practical applications. Copyright © 2017 Elsevier Inc. All rights reserved.

The relationship of metabolic burden to productivity levels in CHO cell lines.

PubMed

Zou, Wu; Edros, Raihana; Al-Rubeai, Mohamed

2018-03-01

The growing demand for recombinant therapeutics has driven biotechnologists to develop new production strategies. One such strategy for increasing the expression of heterologous proteins has focused on enhancing cell-specific productivity through environmental perturbations. In this work, the effects of hypothermia, hyperosmolarity, high shear stress, and sodium butyrate treatment on growth and productivity were studied using three (low, medium, and high producing) CHO cell lines that differed in their specific productivities of monoclonal antibody. In all three cell lines, the inhibitory effect of these parameters on proliferation was demonstrated. Additionally, compared to the control, specific productivity was enhanced under all conditions and exhibited a consistent cell line specific pattern, with maximum increases (50-290%) in the low producer, and minimum increases (7-20%) in the high producer. Thus, the high-producing cell line was less responsive to environmental perturbations than the low-producing cell line. We hypothesize that this difference is most likely due to the bottleneck associated with a higher metabolic burden caused by higher antibody expression. Increased recombinant mRNA levels and pyruvate carboxylase activities due to low temperature and hyperosmotic stress were found to be positively associated with the metabolic burden. © 2017 International Union of Biochemistry and Molecular Biology, Inc.

Synthesis, characterization, antibacterial activity in dark and in vitro cytocompatibility of Ag-incorporated TiO2 microspheres with high specific surface area.

PubMed

Weng, Shengxin; Zhao, Xu; Liu, Guomin; Guan, Yuefeng; Wu, Fanglong; Luo, Yungang

2018-04-23

Postoperative infection associated with medical implants is a devastating complication of orthopedic surgery. Considering the difficulties for the diagnosis and treatment of infection, coating the implant material with antibacterial substances is a promising protocol by which to avoid such an adverse reaction. Nanoparticles (NPs) constructed of anatase microspheres, one form of titanium dioxide (TiO 2 ), with a high specific surface area are fabricated in this study in a facile one-step process using homogeneous precipitation at 90 °C under atmospheric pressure using titanium sulfate (Ti[SO 4 ] 2 ) and urea as the titanium source and precipitant, respectively. The molar ratio of silver (Ag) to TiO 2 can be changed by varying the amount of silver nitrate (AgNO 3 ). The high specific surface area of the TiO 2 microspheres combined with Ag particles (Ag/TiO 2 ) exhibit excellent antibacterial properties against both Staphylococcus aureus and Escherichia coli. In addition, the Ag/TiO 2 material in this work possesses satisfactory biological performance on MC3T3-E1 cells. The high specific surface area of Ag/TiO 2 together with good antibacterial properties and cytocompatibility provide promising applications in dentistry, orthopedics, and other fields of medicine that use biomedical devices.

Well-ordered mesoporous Fe2O3/C composites as high performance anode materials for sodium-ion batteries.

PubMed

Li, Mei; Ma, Chao; Zhu, Qian-Cheng; Xu, Shu-Mao; Wei, Xiao; Wu, Yong-Min; Tang, Wei-Ping; Wang, Kai-Xue; Chen, Jie-Sheng

2017-04-11

Sodium-ion batteries have attracted considerable attention in recent years. In order to promote the practical application of sodium-ion batteries, the electrochemical performances, such as specific capacity, reversibility, and rate capability of the anode materials, should be further improved. In this work, a Fe 2 O 3 /C composite with a well-ordered mesoporous structure is prepared via a facile co-impregnation method by using mesoporous silica SBA-15 as a hard template. When used as an anode material for sodium-ion batteries, the well-ordered mesoporous structure ensures fast mass transport kinetics. The presence of nano-sized Fe 2 O 3 particles confined within the carbon walls significantly enhances the specific capacity of the composite. The carbon walls in the composite act not only as an active material contributing to the specific capacity, but also as a conductive matrix improving the cycling stability of Fe 2 O 3 nanoparticles. As a result, the well-ordered mesoporous Fe 2 O 3 /C composite exhibits high specific capacity, excellent cycleability, and high rate capability. It is proposed that this simple co-impregnation method is applicable for the preparation of well-ordered mesoporous transition oxide/carbon composite electrode materials for high performance sodium-ion and lithium-ion batteries.

In Situ Treatment and Management Strategies for 1,4-Dioxane-Contaminated Groundwater

DTIC Science & Technology

2017-05-05

microorganisms thrived during the biodegradation process. This was consistent with oxidation process that biodiversity was inhibited by the chemical reaction ...exhibit a strong inhibitory impact on CB1190-like bacteria (Figure 79). However, in well 8MNW54, inhibitory impacts of chemical reactions were clear...inhibited again, indicating that chemical reactions along with high CVOCs levels had widely-varying impacts on microorganisms. Specifically, under low DX

Restoring Bottomland Hardwood Forests on U.S. Army Corps of Engineers Lands: 2016 Monitoring Report

DTIC Science & Technology

2018-03-01

a variety of factors, including settlement expansion, agriculture and forestry, and flood control activities (Gardiner and Oliver 2005). During the...of offsetting impacts and conducting mitigation activities. Specifically, agricultural tracts were purchased and reforested by the Vicksburg District...forests previously converted to agriculture , many of which exhibited marginal production due to seasonal high water tables and/or the need for extensive

A novel SWCNT-polyoxometalate nanohybrid material as an electrode for electrochemical supercapacitors

NASA Astrophysics Data System (ADS)

Chen, Han-Yi; Al-Oweini, Rami; Friedl, Jochen; Lee, Ching Yi; Li, Linlin; Kortz, Ulrich; Stimming, Ulrich; Srinivasan, Madhavi

2015-04-01

A novel nanohybrid material that combines single-walled carbon nanotubes (SWCNTs) with a polyoxometalate (TBA)5[PVV2MoVI10O40] (TBA-PV2Mo10, TBA: [(CH3(CH2)3)4N]+, tetra-n-butyl ammonium) is investigated for the first time as an electrode material for supercapacitors (SCs) in this study. The SWCNT-TBA-PV2Mo10 material has been prepared by a simple solution method which electrostatically attaches anionic [PV2Mo10O40]5- anions with organic TBA cations on the SWCNTs. The electrochemical performance of SWCNT-TBA-PV2Mo10 electrodes is studied in an acidic aqueous electrolyte (1 M H2SO4) by galvanostatic charge/discharge and cyclic voltammetry. In this SWCNT-TBA-PV2Mo10 nanohybrid material, TBA-PV2Mo10 provides redox activity while benefiting from the high electrical conductivity and high double-layer capacitance of the SWCNTs that improve both energy and power density. An assembled SWCNT-TBA-PV2Mo10 symmetric SC exhibits a 39% higher specific capacitance as compared to a symmetric SC employing only SWCNTs as electrode materials. Furthermore, the SWCNT-TBA-PV2Mo10 SC exhibits excellent cycling stability, retaining 95% of its specific capacitance after 6500 cycles.

A novel SWCNT-polyoxometalate nanohybrid material as an electrode for electrochemical supercapacitors.

PubMed

Chen, Han-Yi; Al-Oweini, Rami; Friedl, Jochen; Lee, Ching Yi; Li, Linlin; Kortz, Ulrich; Stimming, Ulrich; Srinivasan, Madhavi

2015-05-07

A novel nanohybrid material that combines single-walled carbon nanotubes (SWCNTs) with a polyoxometalate (TBA)5[PVMoO40] (TBA-PV2Mo10, TBA: [(CH3(CH2)3)4N](+), tetra-n-butyl ammonium) is investigated for the first time as an electrode material for supercapacitors (SCs) in this study. The SWCNT-TBA-PV2Mo10 material has been prepared by a simple solution method which electrostatically attaches anionic [PV2Mo10O40](5-) anions with organic TBA cations on the SWCNTs. The electrochemical performance of SWCNT-TBA-PV2Mo10 electrodes is studied in an acidic aqueous electrolyte (1 M H2SO4) by galvanostatic charge/discharge and cyclic voltammetry. In this SWCNT-TBA-PV2Mo10 nanohybrid material, TBA-PV2Mo10 provides redox activity while benefiting from the high electrical conductivity and high double-layer capacitance of the SWCNTs that improve both energy and power density. An assembled SWCNT-TBA-PV2Mo10 symmetric SC exhibits a 39% higher specific capacitance as compared to a symmetric SC employing only SWCNTs as electrode materials. Furthermore, the SWCNT-TBA-PV2Mo10 SC exhibits excellent cycling stability, retaining 95% of its specific capacitance after 6500 cycles.

Metal-Organic Framework Derived Porous Hollow Co3O4/N-C Polyhedron Composite with Excellent Energy Storage Capability.

PubMed

Kang, Wenpei; Zhang, Yu; Fan, Lili; Zhang, Liangliang; Dai, Fangna; Wang, Rongming; Sun, Daofeng

2017-03-29

Metal-organic frameworks (MOFs) derived transition metal oxides exhibit enhanced performance in energy conversion and storage. In this work, porous hollow Co 3 O 4 with N-doped carbon coating (Co 3 O 4 /N-C) polyhedrons have been prepared using cobalt-based MOFs as a sacrificial template. Assembled from tiny nanoparticles and N-doped carbon coating, Co 3 O 4 /N-C composite shortens the diffusion length of Li + /Na + ions and possesses an enhanced conductivity. And the porous and hollow structure is also beneficial for tolerating volume changes in the galvanostatic discharge/charge cycles as lithium/sodium battery anode materials. As a result, it can exhibit impressive cycling and rating performance. At 1000 mA g -1 , the specific capacities maintaine stable values of ∼620 mAh g -1 within 2000 cycles as anodes in lithium ion battery, while the specific capacity keeps at 229 mAh g -1 within 150 cycles as sodium ion battery anode. Our work shows comparable cycling performance in lithium ion battery but even better high-rate cycling stability as sodium ion battery anode. Herein, we provide a facile method to construct high electrochemical performance oxide/N-C composite electrode using new MOFs as sacrificial template.

Serum-deprived human multipotent mesenchymal stromal cells (MSCs) are highly angiogenic

PubMed Central

Oskowitz, Adam; McFerrin, Harris; Gutschow, Miriam; Carter, Mary Leita; Pochampally, Radhika

2016-01-01

Recent reports have indicated that mesenchymal stromal cells (MSCs) from bone marrow have a potential in vascular remodeling and angiogenesis. Here, we report a unique phenomenon that under serum-deprived conditions MSCs survive and replicate. Secretome analysis of MSCs grown under serum-deprived conditions (SD-MSCs) identified a significant upregulation of prosurvival and angiogenic factors including VEGF-A, ANGPTs, IGF-1, and HGF. An ex vivo rat aortic assay demonstrated longer neovascular sprouts generated from rat aortic rings cultured in SD-MSC-conditioned media compared to neovascular sprouts from aortas grown in MSC-conditioned media. With prolonged serum deprivation, a subpopulation of SD-MSCs began to exhibit an endothelial phenotype. This population expressed endothelial-specific proteins including VEGFR2, Tie2/TEK, PECAM/CD31, and eNOS and also demonstrated the ability to uptake acetylated LDL. SD-MSCs also exhibited enhanced microtubule formation in an in vitro angiogenesis assay. Modified chick chorioallantoic membrane (CAM) angiogenesis assays showed significantly higher angiogenic potential for SD-MSCs compared to MSCs. Analysis of CAMs grown with SD-MSCs identified human-specific CD31-positive cells in vascular structures. We conclude that under the stress of serum deprivation MSCs are highly angiogenic and a population of these cells has the potential to differentiate into endothelial-like cells. PMID:21421339

Full-length Transcriptome Sequencing and Modular Organization Analysis of Naringin/Neoeriocitrin Related Gene Expression Pattern in Drynaria roosii.

PubMed

Sun, Mei-Yu; Li, Jing-Yi; Li, Dong; Huang, Feng-Jie; Wang, Di; Li, Hui; Xing, Quan; Zhu, Hui-Bin; Shi, Lei

2018-04-12

Drynaria roosii (Nakaike) is a traditional Chinese medicinal fern, known as 'GuSuiBu'. The corresponding effective components of naringin/neoeriocitrin share highly similar chemical structure and medicinal function. Our HPLC-MS/MS results showed that the accumulation of naringin/neoeriocitrin depended on specific tissues or ages. However, little was known about the expression patterns of naringin/neoeriocitrin related genes involved in their regulatory pathways. For lack of the basic genetic information, we applied a combination of SMRT sequencing and SGS to generate the complete and full-length transcriptome of D. roosii. According to the SGS data, the DEG-based heat map analysis revealed the naringin/neoeriocitrin related gene expression exhibited obvious tissue- and time-specific transcriptomic differences. Using the systems biology method of modular organization analysis, we clustered 16,472 DEGs into 17 gene modules and studied the relationships between modules and tissue/time point samples, as well as modules and naringin/neoeriocitrin contents. Hereinto, naringin/neoeriocitrin related DEGs distributed in nine distinct modules, and DEGs in these modules showed significant different patterns of transcript abundance to be linked with specific tissues or ages. Moreover, WGCNA results further identified that PAL, 4CL, C4H and C3H, HCT acted as the major hub genes involved in naringin and neoeriocitrin synthesis respectively and exhibited high co-expression with MYB- and bHLH-regulated genes. In this work, modular organization and co-expression networks elucidated the tissue- and time-specificity of gene expression pattern, as well as hub genes associated with naringin/neoeriocitrin synthesis in D. roosii. Simultaneously, the comprehensive transcriptome dataset provided the important genetic information for further research on D. roosii.

Waveband specific transcriptional control of select genetic pathways in vertebrate skin (Xiphophorus maculatus).

PubMed

Walter, Ronald B; Boswell, Mikki; Chang, Jordan; Boswell, William T; Lu, Yuan; Navarro, Kaela; Walter, Sean M; Walter, Dylan J; Salinas, Raquel; Savage, Markita

2018-05-10

Evolution occurred exclusively under the full spectrum of sunlight. Conscription of narrow regions of the solar spectrum by specific photoreceptors suggests a common strategy for regulation of genetic pathways. Fluorescent light (FL) does not possess the complexity of the solar spectrum and has only been in service for about 60 years. If vertebrates evolved specific genetic responses regulated by light wavelengths representing the entire solar spectrum, there may be genetic consequences to reducing the spectral complexity of light. We utilized RNA-Seq to assess changes in the transcriptional profiles of Xiphophorus maculatus skin after exposure to FL ("cool white"), or narrow wavelength regions of light between 350 and 600 nm (i.e., 50 nm or 10 nm regions, herein termed "wavebands"). Exposure to each 50 nm waveband identified sets of genes representing discrete pathways that showed waveband specific transcriptional modulation. For example, 350-400 or 450-500 nm waveband exposures resulted in opposite regulation of gene sets marking necrosis and apoptosis (i.e., 350-400 nm; necrosis suppression, apoptosis activation, while 450-500 nm; apoptosis suppression, necrosis activation). Further investigation of specific transcriptional modulation employing successive 10 nm waveband exposures between 500 and 550 nm showed; (a) greater numbers of genes may be transcriptionally modulated after 10 nm exposures, than observed for 50 nm or FL exposures, (b) the 10 nm wavebands induced gene sets showing greater functional specificity than 50 nm or FL exposures, and (c) the genetic effects of FL are primarily due to 30 nm between 500 and 530 nm. Interestingly, many genetic pathways exhibited completely opposite transcriptional effects after different waveband exposures. For example, the epidermal growth factor (EGF) pathway exhibits transcriptional suppression after FL exposure, becomes highly active after 450-500 nm waveband exposure, and again, exhibits strong transcriptional suppression after exposure to the 520-530 nm waveband. Collectively, these results suggest one may manipulate transcription of specific genetic pathways in skin by exposure of the intact animal to specific wavebands of light. In addition, we identify genes transcriptionally modulated in a predictable manner by specific waveband exposures. Such genes, and their regulatory elements, may represent valuable tools for genetic engineering and gene therapy protocols.

Manganese oxide nanowires wrapped with nitrogen doped carbon layers for high performance supercapacitors.

PubMed

Li, Ying; Mei, Yuan; Zhang, Lin-Qun; Wang, Jian-Hai; Liu, An-Ran; Zhang, Yuan-Jian; Liu, Song-Qin

2015-10-01

In this study, manganese oxide nanowires wrapped by nitrogen-doped carbon layers (MnO(x)@NCs) were prepared by carbonization of poly(o-phenylenediamine) layer coated onto MnO2 nanowires for high performance supercapacitors. The component and structure of the MnO(x)@NCs were controlled through carbonization procedure under different temperatures. Results demonstrated that this composite combined the high conductivity and high specific surface area of nitrogen-doped carbon layers with the high pseudo-capacitance of manganese oxide nanowires. The as-prepared MnO(x)@NCs exhibited superior capacitive properties in 1 M Na2SO4 aqueous solution, such as high conductivity (4.167×10(-3) S cm(-1)), high specific capacitance (269 F g(-1) at 10 mV s(-1)) and long cycle life (134 F g(-1) after 1200 cycles at a scan rate of 50 mV s(-1)). It is reckoned that the present novel hybrid nanowires can serve as a promising electrode material for supercapacitors and other electrochemical devices. Copyright © 2015 Elsevier Inc. All rights reserved.

Label-free detection of cardiac troponin-I using gold nanoparticles functionalized single-walled carbon nanotubes based chemiresistive biosensor

NASA Astrophysics Data System (ADS)

Rajesh, Sharma, Vikash; Puri, Nitin K.; Singh, Rajiv K.; Biradar, Ashok M.; Mulchanadani, Ashok

2013-11-01

We report a specific and ultrasensitive, label-free chemiresistive biosensor based on mercaptopropionic acid capped gold nanoparticles (GNP) functionalized single walled carbon nanotube (SWNT) hybrid for the detection of cardiac specific biomarker troponin-I (cTnI). GNPs were attached to SWNTs through a molecular linker 1-pyrenemethylamine. The highly specific cTnI antibody was covalently immobilized on GNPs through capping agent using carbodiimide coupling reaction. The cTnI interaction to its corresponding antibody was studied with respect to changes in conductance in SWNTs channel, and a detailed field-effect transistor characteristic was delineated. The device exhibited a linear response to cTnI from 0.01 to 10 ng ml-1.

Facile synthesis of mesoporous NiO nanoflakes on graphene foam and its electrochemical properties for supercapacitor application

NASA Astrophysics Data System (ADS)

Lv, Jinlong; Wang, Zhuqing; Miura, Hideo

2018-01-01

Many NiO platelets were formed on Ni foam after hydrothermal process, while flower-like NiO with many small mesoporous nanoflakes was obtained on the surface of graphene foam. Electrochemical results showed that the NiO/graphene composites exhibited very high specific capacitance 1062 F g-1 at 1 A g-1 and excellent cycling stability (90.6% capacitance retention after 5000 cycles at 1 A g-1). The promising NiO/graphene composites exhibited higher supercapacitor performance than NiO platelets on Ni foam. The excellent supercapacitor performance of the former should be attributed to the 3D graphene conductive network and the mesoporous NiO nanoflakes which promoted efficient charge transport and electrolyte diffusion.

The median preoptic nucleus exhibits circadian regulation and is involved in food anticipatory activity in rabbit pups.

PubMed

Moreno, María Luisa; Meza, Enrique; Ortega, Arturo; Caba, Mario

2014-05-01

Rabbit pups are a natural model to study food anticipatory activity (FAA). Recently, we reported that three areas in the forebrain - the organum vasculosum of lamina terminalis, median preoptic nucleus (MnPO) and medial preoptic area - exhibit activation during FAA. Here, we examined the PER1 protein profile of these three forebrain regions in both nursed and fasted subjects. We found robust PER1 oscillations in the MnPO in nursed subjects, with high PER1 levels during FAA that persisted in fasted subjects. In conclusion, our data indicate that periodic nursing is a strong signal for PER1 oscillations in MnPO and future experiments are warranted to explore the specific role of this area in FAA.

Porous Carbon with Willow-Leaf-Shaped Pores for High-Performance Supercapacitors.

PubMed

Shi, Yanhong; Zhang, Linlin; Schon, Tyler B; Li, Huanhuan; Fan, Chaoying; Li, Xiaoying; Wang, Haifeng; Wu, Xinglong; Xie, Haiming; Sun, Haizhu; Seferos, Dwight S; Zhang, Jingping

2017-12-13

A novel kind of biomass-derived, high-oxygen-containing carbon material doped with nitrogen that has willow-leaf-shaped pores was synthesized. The obtained carbon material has an exotic hierarchical pore structure composed of bowl-shaped macropores, willow-leaf-shaped pores, and an abundance of micropores. This unique hierarchical porous structure provides an effective combination of high current densities and high capacitance because of a pseudocapacitive component that is afforded by the introduction of nitrogen and oxygen dopants. Our synthetic optimization allows further improvements in the performance of this hierarchical porous carbon (HPC) material by providing a high degree of control over the graphitization degree, specific surface area, and pore volume. As a result, a large specific surface area (1093 m 2 g -1 ) and pore volume (0.8379 cm 3 g -1 ) are obtained for HPC-650, which affords fast ion transport because of its short ion-diffusion pathways. HPC-650 exhibits a high specific capacitance of 312 F g -1 at 1 A g -1 , retaining 76.5% of its capacitance at 20 A g -1 . Moreover, it delivers an energy density of 50.2 W h kg -1 at a power density of 1.19 kW kg -1 , which is sufficient to power a yellow-light-emitting diode and operate a commercial scientific calculator.

Specific surface area of a crushed welded tuff before and after aqueous dissolution

USGS Publications Warehouse

Reddy, M.M.; Claassen, H.C.

1994-01-01

Specific surface areas were measured for several reference minerals (anorthoclase, labradorite and augite), welded tuff and stream sediments from Snowshoe Mountain, near Creede, Colorado. Crushed and sieved tuff had an unexpectedly small variation in specific surface area over a range of size fractions. Replicate surface area measurements of the largest and smallest tuff particle size fractions examined (1-0.3 mm and <0.212 mm) were 2.3 ?? 0.2 m2/g for each size fraction. Reference minerals prepared in the same way as the tuff had smaller specific surface areas than that of the tuff of the same size fraction. Higher than expected tuff specific surface areas appear to be due to porous matrix. Tuff, reacted in solutions with pH values from 2 to 6, had little change in specific surface area in comparison with unreacted tuff. Tuff, reacted with solutions having high acid concentrations (0.1 M hydrochloric acid or sulfuric-hydrofluoric acid), exhibited a marked increase in specific surface area compared to unreacted tuff. ?? 1994.

Biotemplated synthesis of high specific surface area copper-doped hollow spherical titania and its photocatalytic research for degradating chlorotetracycline

NASA Astrophysics Data System (ADS)

Bu, Dan; Zhuang, Huisheng

2013-01-01

Copper-doped titania (Cu/TiO2) hollow microspheres were fabricated using the rape pollen as biotemplates via an improved sol-gel method and a followed calcinations process. In the fabricated process, a titanium(IV)-isopropoxide-based sol directly coated onto the surface of rape pollen. Subsequently, after calcinations, rape pollen was removed by high temperature and the hollow microsphere structure was retained. The average diameter of as-obtained hollow microspheres is 15-20 μm and the thickness of shell is approximately 0.6 μm. Knowing from XRD results, the main crystal phase of microspheres is anatase, coupled with rutile. The specific surface area varied between 141.80 m2/g and 172.51 m2/g. This hollow sphere photocatalysts with high specific surface area exhibited stronger absorption ability and higher photoactivity, stimulated by visible light. The degradation process of chlortetracycline (CTC) solution had been studied. The degradated results indicate that CTC could be effective degradated by fabricated hollow spherical materials. And the intermediate products formed in the photocatalytic process had been identified.

Calcium and Magnesium Ions Are Membrane-Active against Stationary-Phase Staphylococcus aureus with High Specificity

NASA Astrophysics Data System (ADS)

Xie, Yuntao; Yang, Lihua

2016-02-01

Staphylococcus aureus (S. aureus) is notorious for its ability to acquire antibiotic-resistance, and antibiotic-resistant S. aureus has become a wide-spread cause of high mortality rate. Novel antimicrobials capable of eradicating S. aureus cells including antibiotic-resistant ones are thus highly desired. Membrane-active bactericides and species-specific antimicrobials are two promising sources of novel anti-infective agents for fighting against bacterial antibiotic-resistance. We herein show that Ca2+ and Mg2+, two alkaline-earth-metal ions physiologically essential for diverse living organisms, both disrupt model S. aureus membranes and kill stationary-phase S. aureus cells, indicative of membrane-activity. In contrast to S. aureus, Escherichia coli and Bacillus subtilis exhibit unaffected survival after similar treatment with these two cations, indicative of species-specific activity against S. aureus. Moreover, neither Ca2+ nor Mg2+ lyses mouse red blood cells, indicative of hemo-compatibility. This works suggests that Ca2+ and Mg2+ may have implications in targeted eradication of S. aureus pathogen including the antibiotic-resistant ones.

Moderate pathogenic effect of Ligophorus uruguayense (Monogenoidea, Ancyrocephalidae) in juvenile mullet Mugil liza (Actinopterygii, Mugilidae) from Brazil.

PubMed

Pahor-Filho, Eduardo; Klosterhoff, Marta C; Marchiori, Natalia C; Pereira, Joaber

2017-01-01

Monogenoidea pathogenic activity can elicit various histological responses in fish. Species of Ligophorus are specific parasites of mullets, and its relationship with host fish may result in a moderate pathogenic action. In order to ascertain this relationship, estuarine mullets (Mugil liza) were collected in an estuary, reared in laboratory, for three weeks, and forwarded for histological and parasitological analyses. Ligophorus uruguayense (Monogenoidea) infestation in the gills of the mullets was identified. The severe infestation by only one species of Monogenoidea may result from the specificity of these parasites to mullets. Mullets submitted to histological analysis exhibited respiratory epithelium detachment; mild, moderate and severe hyperplasia of the respiratory epithelium; atrophy; and telangiectasia of the gills. This is the first study reporting that mullets highly infested by Monogenoidea can show mild (100%) to severe (20%) gill changes with a distinct frequency of occurrence. Because of the high prevalence of mild alterations observed, it is possible to accept that L. uruguayense is moderately pathogenic to M. liza, even during high prevalence and intensity of infestation, as a result of its specificity.

Boechera Species Exhibit Species-Specific Responses to Combined Heat and High Light Stress

PubMed Central

Gallas, Genna; Waters, Elizabeth R.

2015-01-01

As sessile organisms, plants must be able to complete their life cycle in place and therefore tolerance to abiotic stress has had a major role in shaping biogeographical patterns. However, much of what we know about plant tolerance to abiotic stresses is based on studies of just a few plant species, most notably the model species Arabidopsis thaliana. In this study we examine natural variation in the stress responses of five diverse Boechera (Brassicaceae) species. Boechera plants were exposed to basal and acquired combined heat and high light stress. Plant response to these stresses was evaluated based on chlorophyll fluorescence measurements, induction of leaf chlorosis, and gene expression. Many of the Boechera species were more tolerant to heat and high light stress than A. thaliana. Gene expression data indicates that two important marker genes for stress responses: APX2 (Ascorbate peroxidase 2) and HsfA2 (Heat shock transcription factor A2) have distinct species-specific expression patterns. The findings of species-specific responses and tolerance to stress indicate that stress pathways are evolutionarily labile even among closely related species. PMID:26030823

A "signal on" protection-displacement-hybridization-based electrochemical hepatitis B virus gene sequence sensor with high sensitivity and peculiar adjustable specificity.

PubMed

Li, Fengqin; Xu, Yanmei; Yu, Xiang; Yu, Zhigang; He, Xunjun; Ji, Hongrui; Dong, Jinghao; Song, Yongbin; Yan, Hong; Zhang, Guiling

2016-08-15

One "signal on" electrochemical sensing strategy was constructed for the detection of a specific hepatitis B virus (HBV) gene sequence based on the protection-displacement-hybridization-based (PDHB) signaling mechanism. This sensing system is composed of three probes, one capturing probe (CP) and one assistant probe (AP) which are co-immobilized on the Au electrode surface, and one 3-methylene blue (MB) modified signaling probe (SP) free in the detection solution. One duplex are formed between AP and SP with the target, a specific HBV gene sequence, hybridizing with CP. This structure can drive the MB labels close to the electrode surface, thereby producing a large detection current. Two electrochemical testing techniques, alternating current voltammetry (ACV) and cyclic voltammetry (CV), were used for characterizing the sensor. Under the optimized conditions, the proposed sensor exhibits a high sensitivity with the detection limit of ∼5fM for the target. When used for the discrimination of point mutation, the sensor also features an outstanding ability and its peculiar high adjustability. Copyright © 2016 Elsevier B.V. All rights reserved.

Biomass-derived carbonaceous positive electrodes for sustainable lithium-ion storage

NASA Astrophysics Data System (ADS)

Liu, Tianyuan; Kavian, Reza; Chen, Zhongming; Cruz, Samuel S.; Noda, Suguru; Lee, Seung Woo

2016-02-01

Biomass derived carbon materials have been widely used as electrode materials; however, in most cases, only electrical double layer capacitance (EDLC) is utilized and therefore, only low energy density can be achieved. Herein, we report on redox-active carbon spheres that can be simply synthesized from earth-abundant glucose via a hydrothermal process. These carbon spheres exhibit a specific capacity of ~210 mA h gCS-1, with high redox potentials in the voltage range of 2.2-3.7 V vs. Li, when used as positive electrode in lithium cells. Free-standing, flexible composite films consisting of the carbon spheres and few-walled carbon nanotubes deliver high specific capacities up to ~155 mA h gelectrode-1 with no obvious capacity fading up to 10 000 cycles, proposing to be promising positive electrodes for lithium-ion batteries or capacitors. Furthermore, considering that the carbon spheres were obtained in an aqueous glucose solution and no toxic or hazardous reagents were used, this process opens up a green and sustainable method for designing high performance, environmentally-friendly energy storage devices.Biomass derived carbon materials have been widely used as electrode materials; however, in most cases, only electrical double layer capacitance (EDLC) is utilized and therefore, only low energy density can be achieved. Herein, we report on redox-active carbon spheres that can be simply synthesized from earth-abundant glucose via a hydrothermal process. These carbon spheres exhibit a specific capacity of ~210 mA h gCS-1, with high redox potentials in the voltage range of 2.2-3.7 V vs. Li, when used as positive electrode in lithium cells. Free-standing, flexible composite films consisting of the carbon spheres and few-walled carbon nanotubes deliver high specific capacities up to ~155 mA h gelectrode-1 with no obvious capacity fading up to 10 000 cycles, proposing to be promising positive electrodes for lithium-ion batteries or capacitors. Furthermore, considering that the carbon spheres were obtained in an aqueous glucose solution and no toxic or hazardous reagents were used, this process opens up a green and sustainable method for designing high performance, environmentally-friendly energy storage devices. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07064c

High Energy Density Aqueous Electrochemical Capacitors with a KI-KOH Electrolyte.

PubMed

Wang, Xingfeng; Chandrabose, Raghu S; Chun, Sang-Eun; Zhang, Tianqi; Evanko, Brian; Jian, Zelang; Boettcher, Shannon W; Stucky, Galen D; Ji, Xiulei

2015-09-16

We report a new electrochemical capacitor with an aqueous KI-KOH electrolyte that exhibits a higher specific energy and power than the state-of-the-art nonaqueous electrochemical capacitors. In addition to electrical double layer capacitance, redox reactions in this device contribute to charge storage at both positive and negative electrodes via a catholyte of IOx-/I- couple and a redox couple of H2O/Had, respectively. Here, we, for the first time, report utilizing IOx-/I- redox couple for the positive electrode, which pins the positive electrode potential to be 0.4-0.5 V vs Ag/AgCl. With the positive electrode potential pinned, we can polarize the cell to 1.6 V without breaking down the aqueous electrolyte so that the negative electrode potential could reach -1.1 V vs Ag/AgCl in the basic electrolyte, greatly enhancing energy storage. Both mass spectroscopy and Raman spectrometry confirm the formation of IO3- ions (+5) from I- (-1) after charging. Based on the total mass of electrodes and electrolyte in a practically relevant cell configuration, the device exhibits a maximum specific energy of 7.1 Wh/kg, operates between -20 and 50 °C, provides a maximum specific power of 6222 W/kg, and has a stable cycling life with 93% retention of the peak specific energy after 14,000 cycles.

Mesoporous nickel oxide nanowires: hydrothermal synthesis, characterisation and applications for lithium-ion batteries and supercapacitors with superior performance.

PubMed

Su, Dawei; Kim, Hyun-Soo; Kim, Woo-Seong; Wang, Guoxiu

2012-06-25

Mesoporous nickel oxide nanowires were synthesized by a hydrothermal reaction and subsequent annealing at 400 °C. The porous one-dimensional nanostructures were analysed by field-emission SEM, high-resolution TEM and N(2) adsorption/desorption isotherm measurements. When applied as the anode material in lithium-ion batteries, the as-prepared mesoporous nickel oxide nanowires demonstrated outstanding electrochemical performance with high lithium storage capacity, satisfactory cyclability and an excellent rate capacity. They also exhibited a high specific capacitance of 348 F g(-1) as electrodes in supercapacitors. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis and preliminary evaluation of [3H]PSB-0413, a selective antagonist radioligand for platelet P2Y12 receptors.

PubMed

El-Tayeb, Ali; Griessmeier, Kerstin J; Müller, Christa E

2005-12-15

The selective antagonist radioligand [(3)H]2-propylthioadenosine-5'-adenylic acid (1,1-dichloro-1-phosphonomethyl-1-phosphonyl) anhydride ([(3)H]PSB-0413) was prepared by catalytic hydrogenation of its propargyl precursor with a high specific radioactivity of 74Ci/mmol. In preliminary saturation binding studies, [(3)H]PSB-0413 showed high affinity for platelet P2Y(12) receptors with a K(D) value of 4.57nM. Human platelets had a high density of P2Y(12) receptors exhibiting a B(max) value of 7.66pmol/mg of protein.

3D carbon/cobalt-nickel mixed-oxide hybrid nanostructured arrays for asymmetric supercapacitors.

PubMed

Zhu, Jianhui; Jiang, Jian; Sun, Zhipeng; Luo, Jingshan; Fan, Zhanxi; Huang, Xintang; Zhang, Hua; Yu, Ting

2014-07-23

The electrochemical performance of supercapacitors relies not only on the exploitation of high-capacity active materials, but also on the rational design of superior electrode architectures. Herein, a novel supercapacitor electrode comprising 3D hierarchical mixed-oxide nanostructured arrays (NAs) of C/CoNi3 O4 is reported. The network-like C/CoNi3 O4 NAs exhibit a relatively high specific surface area; it is fabricated from ultra-robust Co-Ni hydroxide carbonate precursors through glucose-coating and calcination processes. Thanks to their interconnected three-dimensionally arrayed architecture and mesoporous nature, the C/CoNi3 O4 NA electrode exhibits a large specific capacitance of 1299 F/g and a superior rate performance, demonstrating 78% capacity retention even when the discharge current jumps by 100 times. An optimized asymmetric supercapacitor with the C/CoNi3 O4 NAs as the positive electrode is fabricated. This asymmetric supercapacitor can reversibly cycle at a high potential of 1.8 V, showing excellent cycling durability and also enabling a remarkable power density of ∼13 kW/kg with a high energy density of ∼19.2 W·h/kg. Two such supercapacitors linked in series can simultaneously power four distinct light-emitting diode indicators; they can also drive the motor of remote-controlled model planes. This work not only presents the potential of C/CoNi3 O4 NAs in thin-film supercapacitor applications, but it also demonstrates the superiority of electrodes with such a 3D hierarchical architecture. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Comparative genomics of citric-acid producing Aspergillus niger ATCC 1015 versus enzyme-producing CBS 513.88

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

Andersen, Mikael R.; Salazar, Margarita; Schaap, Peter

2011-06-01

The filamentous fungus Aspergillus niger exhibits great diversity in its phenotype. It is found globally, both as marine and terrestrial strains, produces both organic acids and hydrolytic enzymes in high amounts, and some isolates exhibit pathogenicity. Although the genome of an industrial enzyme-producing A. niger strain (CBS 513.88) has already been sequenced, the versatility and diversity of this species compels additional exploration. We therefore undertook whole genome sequencing of the acidogenic A. niger wild type strain (ATCC 1015), and produced a genome sequence of very high quality. Only 15 gaps are present in the sequence and half the telomeric regionsmore » have been elucidated. Moreover, sequence information from ATCC 1015 was utilized to improve the genome sequence of CBS 513.88. Chromosome-level comparisons uncovered several genome rearrangements, deletions, a clear case of strain-specific horizontal gene transfer, and identification of 0.8 megabase of novel sequence. Single nucleotide polymorphisms per kilobase (SNPs/kb) between the two strains were found to be exceptionally high (average: 7.8, maximum: 160 SNPs/kb). High variation within the species was confirmed with exo-metabolite profiling and phylogenetics. Detailed lists of alleles were generated, and genotypic differences were observed to accumulate in metabolic pathways essential to acid production and protein synthesis. A transcriptome analysis revealed up-regulation of the electron transport chain, specifically the alternative oxidative pathway in ATCC 1015, while CBS 513.88 showed significant up regulation of genes associated with biosynthesis of amino acids that are abundant in glucoamylase A, tRNA-synthases and protein transporters.« less

Introducing a multivariate model for predicting driving performance: the role of driving anger and personal characteristics.

PubMed

Roidl, Ernst; Siebert, Felix Wilhelm; Oehl, Michael; Höger, Rainer

2013-12-01

Maladaptive driving is an important source of self-inflicted accidents and this driving style could include high speeds, speeding violations, and poor lateral control of the vehicle. The literature suggests that certain groups of drivers, such as novice drivers, males, highly motivated drivers, and those who frequently experience anger in traffic, tend to exhibit more maladaptive driving patterns compared to other drivers. Remarkably, no coherent framework is currently available to describe the relationships and distinct influences of these factors. We conducted two studies with the aim of creating a multivariate model that combines the aforementioned factors, describes their relationships, and predicts driving performance more precisely. The studies employed different techniques to elicit emotion and different tracks designed to explore the driving behaviors of participants in potentially anger-provoking situations. Study 1 induced emotions with short film clips. Study 2 confronted the participants with potentially anger-inducing traffic situations during the simulated drive. In both studies, participants who experienced high levels of anger drove faster and exhibited greater longitudinal and lateral acceleration. Furthermore, multiple linear regressions and path-models revealed that highly motivated male drivers displayed the same behavior independent of their emotional state. The results indicate that anger and specific risk characteristics lead to maladaptive changes in important driving parameters and that drivers with these specific risk factors are prone to experience more anger while driving, which further worsens their driving performance. Driver trainings and anger management courses will profit from these findings because they help to improve the validity of assessments of anger related driving behavior. © 2013.

Supercapacitors based on pillared graphene nanostructures.

PubMed

Lin, Jian; Zhong, Jiebin; Bao, Duoduo; Reiber-Kyle, Jennifer; Wang, Wei; Vullev, Valentine; Ozkan, Mihrimah; Ozkan, Cengiz S

2012-03-01

We describe the fabrication of highly conductive and large-area three dimensional pillared graphene nanostructure (PGN) films from assembly of vertically aligned CNT pillars on flexible copper foils for applications in electric double layer capacitors (EDLC). The PGN films synthesized via a one-step chemical vapor deposition process on flexible copper foils exhibit high conductivity with sheet resistance as low as 1.6 ohms per square and possessing high mechanical flexibility. Raman spectroscopy indicates the presence of multi walled carbon nanotubes (MWCNT) and their morphology can be controlled by the growth conditions. It was discovered that nitric acid treatment can significantly increase the specific capacitance of the devices. EDLC devices based on PGN electrodes (surface area of 565 m2/g) demonstrate enhanced performance with specific capacitance value as high as 330 F/g extracted from the current density-voltage (CV) measurements and energy density value of 45.8 Wh/kg. The hybrid graphene-CNT nanostructures are attractive for applications including supercapacitors, fuel cells and batteries.

Ultrathin porous NiCo2O4 nanosheet arrays on flexible carbon fabric for high-performance supercapacitors.

PubMed

Du, Jun; Zhou, Gang; Zhang, Haiming; Cheng, Chao; Ma, Jianmin; Wei, Weifeng; Chen, Libao; Wang, Taihong

2013-08-14

NiCo2O4 with higher specific capacitance is an excellent pseudocapacitive material. However, the bulk NiCo2O4 material prevents the achievement of high energy desity and great rate performance due to the limited electroactive surface area. In this work, NiCo2O4 nanosheet arrays were deposited on flexible carbon fabric (CF) as a high-performance electrode for supercapacitors. The NiCo2O4 arrays were constructed by interconnected ultrathin nanosheets (10 nm) with many interparticle pores. The porous feature of NiCo2O4 nanosheets increases the amount of electroactive sites and facilitates the electrolyte penetration. Hence, the NiCo2O4/CF composites exhibited a high specific capacitance of 2658 F g(-1) (2 A g(-1)), good rate performance, and superior cycling life, suggesting the NiCo2O4/CF is a promising electrode material for flexible electrochemical capacitors.

Nitrogen-doped ordered mesoporous carbon with a high surface area, synthesized through organic-inorganic coassembly, and its application in supercapacitors.

PubMed

Song, Yanfang; Li, Li; Wang, Yonggang; Wang, Congxiao; Guo, Zaipin; Xia, Yongyao

2014-07-21

A new nitrogen-doped ordered mesoporous carbon (N-doped OMC) is synthesized by using an organic-inorganic coassembly method, in which resol is used as the carbon precursor, dicyandiamide as the nitrogen precursor, silicate oligomers as the inorganic precursors, and F127 as the soft template. The N-doped OMC possesses a surface area as high as 1374 m(2)  g(-1) and a large pore size of 7.4 nm. As an electrode material for supercapacitors, the obtained carbon exhibits excellent cycling stability and delivers a reversible specific capacitance as high as 308 F g(-1) in 1 mol L(-1) H(2)SO(4) aqueous electrolyte, of which 58 % of the capacity is due to pseudo-capacitance. The large specific capacitance is attributed to proper pore size distributions, large surface area, and high nitrogen content. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Flute type micropores activated carbon from cotton stalk for high performance supercapacitors

NASA Astrophysics Data System (ADS)

Tian, Xun; Ma, Hongru; Li, Zhe; Yan, Shaocun; Ma, Lei; Yu, Feng; Wang, Gang; Guo, Xuhong; Ma, Yanqing; Wong, Chingping

2017-08-01

Flute type micropores activated carbon (FTMAC) has been successfully obtained from cotton stalk via KOH-chemical activation method. The synthesized carbon material exhibits an ordered pore structure with high specific surface area of 1964.46 m2 g-1 and pore volume of 1.03 m3 g-1. The assembled FTMAC-based electrode delivers a high specific capacitance of 254 F g-1 at a current density of 0.2 A g-1 in 1 M H2SO4 aqueous electrolyte. It still can maintain 221 F g-1at a current density of 10 A g-1, demonstrating a good rate capacity (87% retention), as well as long cyclic stability of 96% capacitance retention after 10000 charging and discharging cycles at current density of 1 A g-1. Moreover, the symmetric supercapacitor can deliver a high energy density of 18.14 W h kg-1 and a power density of 450.37 W kg-1 which is operated in the voltage range of 0-1.8 V.

Diamond and Carbon Nanotube Composites for Supercapacitor Devices

NASA Astrophysics Data System (ADS)

Moreira, João Vitor Silva; May, Paul William; Corat, Evaldo José; Peterlevitz, Alfredo Carlos; Pinheiro, Romário Araújo; Zanin, Hudson

2017-02-01

We report on the synthesis and electrochemical properties of diamond grown onto vertically aligned carbon nanotubes with high surface areas as a template, resulting in a composite material exhibiting high double-layer capacitance as well as low electrochemical impedance electrodes suitable for applications as supercapacitor devices. We contrast results from devices fabricated with samples which differ in both their initial substrates (Si and Ti) and their final diamond coatings, such as boron-doped diamond and diamond-like carbon (DLC). We present for first time a conducting model for non-doped DLC thin-films. All samples were characterized by scanning and transmission electron microscopy and Fourier transform infrared and Raman spectroscopy. Our results show specific capacitance as high as 8.25 F g-1 (˜1 F cm-2) and gravimetric specific energy and power as high as 0.7 W h kg-1 and 176.4 W kg-1, respectively, which suggest that these diamond/carbon nanotube composite electrodes are excellent candidates for supercapacitor fabrication.

Ultrashort megaelectronvolt positron beam generation based on laser-accelerated electrons

NASA Astrophysics Data System (ADS)

Xu, Tongjun; Shen, Baifei; Xu, Jiancai; Li, Shun; Yu, Yong; Li, Jinfeng; Lu, Xiaoming; Wang, Cheng; Wang, Xinliang; Liang, Xiaoyan; Leng, Yuxin; Li, Ruxin; Xu, Zhizhan

2016-03-01

Experimental generation of ultrashort MeV positron beams with high intensity and high density using a compact laser-driven setup is reported. A high-density gas jet is employed experimentally to generate MeV electrons with high charge; thus, a charge-neutralized MeV positron beam with high density is obtained during laser-accelerated electrons irradiating high-Z solid targets. It is a novel electron-positron source for the study of laboratory astrophysics. Meanwhile, the MeV positron beam is pulsed with an ultrashort duration of tens of femtoseconds and has a high peak intensity of 7.8 × 1021 s-1, thus allows specific studies of fast kinetics in millimeter-thick materials with a high time resolution and exhibits potential for applications in positron annihilation spectroscopy.

A comparison of five serological tests for bovine brucellosis.

PubMed Central

Dohoo, I R; Wright, P F; Ruckerbauer, G M; Samagh, B S; Robertson, F J; Forbes, L B

1986-01-01

Five serological assays: the buffered plate antigen test, the standard tube agglutination test, the complement fixation test, the hemolysis-in-gel test and the indirect enzyme immunoassay were diagnostically evaluated. Test data consisted of results from 1208 cattle in brucellosis-free herds, 1578 cattle in reactor herds of unknown infection status and 174 cattle from which Brucella abortus had been cultured. The complement fixation test had the highest specificity in both nonvaccinated and vaccinated cattle. The indirect enzyme immunoassay, if interpreted at a high threshold, also exhibited a high specificity in both groups of cattle. The hemolysis-in-gel test had a very high specificity when used in nonvaccinated cattle but quite a low specificity among vaccinates. With the exception of the complement fixation test, all tests had high sensitivities if interpreted at the minimum threshold. However, the sensitivities of the standard tube agglutination test and indirect enzyme immunoassay, when interpreted at high thresholds were comparable to that of the complement fixation test. A kappa statistic was used to measure the agreement between the various tests. In general the kappa statistics were quite low, suggesting that the various tests may detect different antibody isotypes. There was however, good agreement between the buffered plate antigen test and standard tube agglutination test (the two agglutination tests evaluated) and between the complement fixation test and the indirect enzyme immunoassay when interpreted at a high threshold. With the exception of the buffered plate antigen test, all tests were evaluated as confirmatory tests by estimating their specificity and sensitivity on screening-test positive samples.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3539295

Enhancing the passing moments: An educational criticism of family visits to an early childhood science exhibition

NASA Astrophysics Data System (ADS)

Munroe, Elizabeth Ann

This educational criticism describes and interprets the nature of family visits to an early childhood science exhibition, Working Wonders, at The Science Centre in Calgary, Alberta. The specific exhibits are described and features that contributed to exhibit popularity are examined. Examples of visitors' interactions with each exhibit are given. The visit experiences of four families are described in detail and analyzed. Typical family visitors' reactions, expectations, and experiences are summarized. Because one of the mutual expectations of the granting agency, The Science Centre, and the adult visitors was that a visit to the exhibition would be educational, the family visits are examined for instances of learning and analyzed to determine the factors that influenced the learning. Constructivism forms the basis for understanding the process of learning during family visits. The analysis is supported by reference to research from the fields of museum studies, education, and environmental design. The analysis of the educational significance and potential of family visits to an early childhood exhibition leads to the conclusion that specific features may facilitate learning in such an environment. Those features are represented in a set of guidelines for the development and evaluation of early childhood exhibitions. The guidelines suggest attention must be given to the ambience of the space, the general layout of the space, the exhibits, the copy and graphics, additional programs and information, the subtle influences of the building and the staff, and the learning processes of young children, adults, and intergenerational groups. The guidelines suggest specific issues to consider to develop a space that is stimulating and memorable, responsive to the needs of the two distinct visitor groups (young children and adults), and conducive to learning.

A highly sensitive and specific capacitive aptasensor for rapid and label-free trace analysis of Bisphenol A (BPA) in canned foods.

PubMed

Mirzajani, Hadi; Cheng, Cheng; Wu, Jayne; Chen, Jiangang; Eda, Shigotoshi; Najafi Aghdam, Esmaeil; Badri Ghavifekr, Habib

2017-03-15

A rapid, highly sensitive, specific and low-cost capacitive affinity biosensor is presented here for label-free and single step detection of Bisphenol A (BPA). The sensor design allows rapid prototyping at low-cost using printed circuit board material by benchtop equipment. High sensitivity detection is achieved through the use of a BPA-specific aptamer as probe molecule and large electrodes to enhance AC-electroelectrothermal effect for long-range transport of BPA molecules toward electrode surface. Capacitive sensing technique is used to determine the bounded BPA level by measuring the sample/electrode interfacial capacitance of the sensor. The developed biosensor can detect BPA level in 20s and exhibits a large linear range from 1 fM to 10 pM, with a limit of detection (LOD) of 152.93 aM. This biosensor was applied to test BPA in canned food samples and could successfully recover the levels of spiked BPA. This sensor technology is demonstrated to be highly promising and reliable for rapid, sensitive and on-site monitoring of BPA in food samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Nitrogen-doped graphitic hierarchically porous carbon nanofibers obtained via bimetallic-coordination organic framework modification and their application in supercapacitors.

PubMed

Yao, Yuechao; Liu, Peng; Li, Xiaoyan; Zeng, Shaozhong; Lan, Tongbin; Huang, Haitao; Zeng, Xierong; Zou, Jizhao

2018-05-17

Herein, N-doped graphitic hierarchically porous carbon nanofibers (NGHPCF) were prepared by electrospinning the composite of bimetallic-coordination metal-organic frameworks and polyacrylonitrile, followed by a pyrolysis and acid wash process. Control over the N content, specific surface area, and degree of graphitization of NGHPCF materials has been realized by adjusting the Co/Zn metal coordination content as well as the pyrolysis temperature. The obtained NGHPCF with a high specific surface area (623 m2 g-1) and nitrogen content (13.83 wt%) exhibit a high capacitance of 326 F g-1 at 0.5 A g-1. In addition, the capacitance of 170 F g-1 is still maintained at a high current density (40 A g-1); this indicates a high capacitance retention capability. Furthermore, a superb energy density (9.61 W h kg-1) is obtained with a high power density (62.4 W kg-1) using an organic electrolyte. These results fully illustrate that the prepared NGHPCF binder-free electrodes are promising candidates for high-performance supercapacitors.

Controllable synthesis of mesoporous Co{sub 3}O{sub 4} nanoflake array and its application for supercapacitor

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

Xiao, Anguo, E-mail: hixiaoanguo@126.com; Zhou, Shibiao; Zuo, Chenggang

Graphical abstract: Electrodeposited mesoporous Co{sub 3}O{sub 4} nanoflake arrays exhibit porous structure composed of mesoporous nanoflakes and high supercapacitor performance. - Highlights: • Mesoporous Co{sub 3}O{sub 4} nanoflake arrays are prepared via electrodeposition method. • Mesoporous nanowall arrays are favorable for fast ion/electron transfer. • Mesoporous Co{sub 3}O{sub 4} nanoflake arrays show excellent supercapacitor performance. - Abstract: A mesoporous Co{sub 3}O{sub 4} nanoflake array grown on carbon cloth is prepared by a facile electrodeposition method with a following annealing process. The as-prepared Co{sub 3}O{sub 4} nanoflake possesses a continuous mesopores ranging from 2 to 5 nm and grows tightly onmore » the substrate forming a porous net-like structure with macropores of 20–200 nm. The electrochemical performance of the mesoporous Co{sub 3}O{sub 4} nanoflake arrays as pseudocapcitor electrode are investigated by cyclic voltammograms and galvanostatic charge/discharge tests in 2 M KOH. The as-prepared Co{sub 3}O{sub 4} array exhibits a high discharge capacitance and excellent rate capability with 450 F g{sup −1}, 436 F g{sup −1}, 408 F g{sup −1}, 380 F g{sup −1}and 363 F g{sup −1} at 1, 2, 4, 10, and 20 A g{sup −1}, respectively. The specific capacitance of 81% is maintained from 1 A g{sup −1} to 20 A g{sup −1}. The electrode also shows rather good cycling stability and exhibits a specific capacitance of 414 F g{sup −1} after 5000 cycles.« less

Rational Construction of Hollow Core-Branch CoSe2 Nanoarrays for High-Performance Asymmetric Supercapacitor and Efficient Oxygen Evolution.

PubMed

Chen, Tian; Li, Songzhan; Wen, Jian; Gui, Pengbin; Guo, Yaxiong; Guan, Cao; Liu, Jinping; Fang, Guojia

2018-02-01

Metal selenides have great potential for electrochemical energy storage, but are relatively scarce investigated. Herein, a novel hollow core-branch CoSe 2 nanoarray on carbon cloth is designed by a facile selenization reaction of predesigned CoO nanocones. And the electrochemical reaction mechanism of CoSe 2 in supercapacitor is studied in detail for the first time. Compared with CoO, the hollow core-branch CoSe 2 has both larger specific surface area and higher electrical conductivity. When tested as a supercapacitor positive electrode, the CoSe 2 delivers a high specific capacitance of 759.5 F g -1 at 1 mA cm -2 , which is much larger than that of CoO nanocones (319.5 F g -1 ). In addition, the CoSe 2 electrode exhibits excellent cycling stability in that a capacitance retention of 94.5% can be maintained after 5000 charge-discharge cycles at 5 mA cm -2 . An asymmetric supercapacitor using the CoSe 2 as cathode and an N-doped carbon nanowall as anode is further assembled, which show a high energy density of 32.2 Wh kg -1 at a power density of 1914.7 W kg -1 , and maintains 24.9 Wh kg -1 when power density increased to 7354.8 W kg -1 . Moreover, the CoSe 2 electrode also exhibits better oxygen evolution reaction activity than that of CoO. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of sex on ethanol consumption and conditioned taste aversion in adolescent and adult rats.

PubMed

Schramm-Sapyta, Nicole L; Francis, Reynold; MacDonald, Andrea; Keistler, Colby; O'Neill, Lauren; Kuhn, Cynthia M

2014-04-01

Vulnerability to alcoholism is determined by many factors, including the balance of pleasurable vs. aversive alcohol-induced sensations: pleasurable sensations increase intake, while aversive sensations decrease it. Female sex and adolescent age are associated with lower sensitivity to intake-reducing effects and more rapid development of alcohol abuse. This study assessed voluntary drinking and the aversive effects of alcohol to determine whether these measures are inversely related across the sexes and development. Voluntary drinking of 20 % ethanol in an every-other-day (EOD) availability pattern and the dose-response relationship of ethanol conditioned taste aversion (CTA) were assessed in male and female adolescent and adult rats. CTA was sex specific in adult but not adolescent rats, with adult females exhibiting less aversion. Voluntary ethanol consumption varied according to age and individual differences but was not sex specific. Adolescents initially drank more than adults, exhibited greater day-to-day variation in consumption, were more susceptible to the alcohol deprivation effect, and took longer to establish individual differences in consumption patterns. These results show that the emergence of intake patterns differs between adolescents and adults. Adolescents as a group initiate drinking at high levels but decrease intake as they mature. A subset of adolescents maintained high drinking levels into adulthood. In contrast, most adults consumed at steady, low levels, but a small subset quickly established and maintained high-consumption patterns. Adolescents also showed marked deprivation-induced increases. Sex differences were not observed in EOD drinking during either adolescence or adulthood.

Microstructure, electrical properties, and thermal stability of Au-based ohmic contacts to p-GaN

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

Smith, L.L.; Davis, R.F.; Kim, M.J.

1997-09-01

The work described in this paper is part of a systematic study of ohmic contact strategies for GaN-based semiconductors. Au contacts exhibited ohmic behavior on p-GaN when annealed at high temperature. The specific contact resistivity ({rho}{sub c}) calculated from TLM measurements on Au/p-GaN contacts was 53{Omega}{center_dot}cm{sup 2} after annealing at 800{degree}C. Multilayer Au/Mg/Au/p-GaN contacts exhibited linear, ohmic current-voltage (I-V) behavior in the as-deposited condition with {rho}{sub c}=214{Omega}{center_dot}cm{sup 2}. The specific contact resistivity of the multilayer contact increased significantly after rapid thermal annealing (RTA) through 725{degree}C. Cross-sectional microstructural characterization of the Au/p-GaN contact system via high-resolution electron microscopy (HREM) revealed thatmore » interfacial secondary phase formation occurred during high-temperature treatments, which coincided with the improvement of contact performance. In the as-deposited multilayer Au/Mg/Au/p-GaN contact, the initial 32 nm Au layer was found to be continuous. However, Mg metal was found in direct contact with the GaN in many places in the sample after annealing at 725{degree}C for 15 s. The resultant increase in contact resistance is believed to be due to the barrier effect increased by the presence of the low work function Mg metal. {copyright} {ital 1997 Materials Research Society.}« less

Interpersonal style moderates the effect of dating violence on symptoms of anxiety and depression.

PubMed

Yalch, Matthew M; Lannert, Brittany K; Hopwood, Christopher J; Levendosky, Alytia A

2013-11-01

Over a quarter of young women have experienced some form of violence within a dating relationship. The experience of dating violence is associated with problems in psychological functioning, including symptoms of anxiety and depression. However, not all women who experience dating violence exhibit anxious or depressive symptoms. One factor that may influence symptom expression is interpersonal style. In this study, we examined the main and moderating effects of dimensions of interpersonal style (dominance and warmth) on the association between dating violence and symptoms of anxiety and depression. Warmth exhibited a main effect on anxious and depressive symptoms over and above the effects of dating violence and other life stressors. Dominance moderated the association between dating violence and anxious and depressive symptoms. When levels of dating violence were high, women with higher levels of dominance reported fewer symptoms of anxiety and depression than women with lower dominance. These results indicated that whereas high warmth was associated with fewer symptoms of psychopathology generally, high dominance was a buffer against the effect of dating violence on symptoms more specifically. Directions for future research are discussed.

Electrochemical immunosensor with NiAl-layered double hydroxide/graphene nanocomposites and hollow gold nanospheres double-assisted signal amplification.

PubMed

Qiao, Lu; Guo, Yemin; Sun, Xia; Jiao, Yancui; Wang, Xiangyou

2015-08-01

A sensitive electrochemical immunosensor based on NiAl-layered double hydroxide/graphene nanocomposites (NiAl-LDH/G) and hollow gold nanospheres (HGNs) was proposed for chlorpyrifos detection. The NiAl-LDH/G was prepared using a conventional coprecipitation process and reduction of the supporting graphene oxide. Subsequently, the nanocomposites were dispersed with chitosan (CS). The NiAl-LDH/G possessed good electrochemical behavior and high binding affinity to the electrode. The high surface areas of HGNs and the vast aminos and hydroxyls of CS provided a platform for the covalently crosslinking of antibody. Under optimal conditions, the immunosensor exhibited a wide linear range from 5 to 150 μg/mL and from 150 to 2 μg/mL, with a detection limit of 0.052 ng/mL. The detection results showed good agreement with standard gas chromatography method. The constructed immunosensor exhibited good reproducibility, high specificity, acceptable stability and regeneration performance, which provided a new promising tool for chlorpyrifos detection in real samples.

Correlated evolution between hearing sensitivity and social calls in bats

PubMed Central

Bohn, Kirsten M; Moss, Cynthia F; Wilkinson, Gerald S

2006-01-01

Echolocating bats are auditory specialists, with exquisite hearing that spans several octaves. In the ultrasonic range, bat audiograms typically show highest sensitivity in the spectral region of their species-specific echolocation calls. Well-developed hearing in the audible range has been commonly attributed to a need to detect sounds produced by prey. However, bat pups often emit isolation calls with low-frequency components that facilitate mother–young reunions. In this study, we examine whether low-frequency hearing in bats exhibits correlated evolution with (i) body size; (ii) high-frequency hearing sensitivity or (iii) pup isolation call frequency. Using published audiograms, we found that low-frequency hearing sensitivity is not dependent on body size but is related to high-frequency hearing. After controlling for high-frequency hearing, we found that low-frequency hearing exhibits correlated evolution with isolation call frequency. We infer that detection and discrimination of isolation calls have favoured enhanced low-frequency hearing because accurate parental investment is critical: bats have low reproductive rates, non-volant altricial young and must often identify their pups within large crèches. PMID:17148288

Ru-assisted synthesis of Pd/Ru nanodendrites with high activity for ethanol electrooxidation.

PubMed

Zhang, Ke; Bin, Duan; Yang, Beibei; Wang, Caiqin; Ren, Fangfang; Du, Yukou

2015-08-07

Due to the specific physical and chemical properties of a highly branched noble metal, the controllable synthesis has attracted much attention. This article reports the synthesis of Pd/Ru nanodendrites by a facile method using an oil bath in the presence of polyvinyl pyrrolidone, potassium bromide and ascorbic acid. The morphology, structure, and composition of the as-prepared catalysts were characterized by means of X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. In the electrochemical measurement, the as-prepared Pd7/Ru1 bimetallic nanodendrites provide a large electrochemically active surface area and exhibit high peak current density in the forward scan toward ethanol electrooxidation, which is nearly four times higher than those of a pure Pd catalyst. The as-prepared Pd7/Ru1 catalysts also exhibit significantly enhanced cycling stability toward ethanol oxidation in alkaline medium, which are mainly ascribed to the synergetic effect between Pd and Ru. This indicates that the Pd7/Ru1 catalysts should have great potential applications in direct ethanol fuel cells.

Highly specific detection of H2O2-dependent luminol chemiluminescence in stimulated human leukocytes using polyvinyl films.

PubMed

Moriguchi, K; Ohno, N; Ogawa, T; Hirai, K

1999-01-01

When human polymorphonuclear leukocytes (PMN) were attached to glass coverslips, cells always spread and formed reactive oxygen species prior to any experimental stimulation. To avoid this, a polyvinylidine chloride film was used as an inactive substance to place the cells. Cells engaged in phagocytosis on the film exhibited a specific H2O2-mediated luminol chemiluminescence (LCL) at the cell-particle interface; the cells stimulated with 12-O-tetradecanoylphorbol-13-acetate became aggregated and the LCL was observed at the cell-cell contact. These results corresponded well with those obtained by an electron microscopic H2O2-demonstration method.

Tungsten carbide/porous carbon composite as superior support for platinum catalyst toward methanol electro-oxidation

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

Jiang, Liming; Fu, Honggang, E-mail: fuhg@vip.sina.com; Key Laboratory of Functional Inorganic Material Chemistry, Heilongjiang University, Harbin 150080

2014-01-01

Graphical abstract: The WC nanoparticles are well dispersed in the carbon matrix. The size of WC nanoparticles is about 30 nm. It can be concluded that tungsten carbide and carbon composite was successfully prepared by the present synthesis conditions. - Highlights: • The WC/PC composite with high specific surface area was prepared by a simple way. • The Pt/WC/PC catalyst has superior performance toward methanol electro-oxidation. • The current density for methanol electro-oxidation is as high as 595.93 A g{sup −1} Pt. • The Pt/WC/PC catalyst shows better durability and stronger CO electro-oxidation. • The performance of Pt/WC/PC is superiormore » to the commercial Pt/C (JM) catalyst. - Abstract: Tungsten carbide/porous carbon (WC/PC) composites have been successfully synthesized through a surfactant assisted evaporation-induced-assembly method, followed by a thermal treatment process. In particular, WC/PC-35-1000 composite with tungsten content of 35% synthesized at the carbonized temperature of 1000 °C, exhibited a specific surface area (S{sub BET}) of 457.92 m{sup 2} g{sup −1}. After loading Pt nanoparticles (NPs), the obtained Pt/WC/PC-35-1000 catalyst exhibits the highest unit mass electroactivity (595.93 A g{sup −1} Pt) toward methanol electro-oxidation, which is about 2.6 times as that of the commercial Pt/C (JM) catalyst. Furthermore, the Pt/WC/PC-35-1000 catalyst displays much stronger resistance to CO poisoning and better durability toward methanol electrooxidation compared with the commercial Pt/C (JM) catalyst. The high electrocatalytic activity, strong poison-resistivity and good stability of Pt/WC/PC-35-1000 catalyst are attributed to the porous structures and high specific surface area of WC/PC support could facilitate the rapid mass transportation. Moreover, synergistic effect between WC and Pt NPs is favorable to the higher catalytic performance.« less

Marine phages as excellent tracers for reactive colloidal transport in porous media

NASA Astrophysics Data System (ADS)

Ghanem, Nawras; Chatzinotas, Antonis; Harms, Hauke; Wick, Lukas Y.

2016-04-01

Question: Here we evaluate marine phages as specific markers of hydrological flow and reactive transport of colloidal particles in the Earth's critical zone (CZ). Marine phages and their bacterial hosts are naturally absent in the CZ, and can be detected with extremely high sensitivity. In the framework of the DFG Collaborative Research Center AquaDiva, we asked the following questions: (1) Are marine phages useful specific markers of hydrological flow and reactive transport in porous media? and (2) Which phage properties are relevant drivers for the transport of marine phages in porous media? Methods: Seven marine phages from different families (as well two commonly used terrestrial phages) were selected based on their morphology, size and physico-chemical surface properties (surface charge and hydrophobicity). Phage properties were assessed by electron microscopy, dynamic light scattering and water contact angle analysis (CA). Sand-filled laboratory percolation columns were used to study transport. The breakthrough curves of the phages were analyzed using the clean bed filtration theory and the XDLVO theory of colloid stability, respectively. Phages were quantified by a modified high- throughput plaque assay and a culture-independent particle counting method approach. Results: Our data show that most marine tested phages exhibited highly variable transport rates and deposition efficiency, yet generally high colloidal stability and viability. We find that size, morphology and hydrophobicity are key factors shaping the transport efficiency of phages. Differing deposition efficiencies of the phages were also supported by calculated XDLVO interaction energy profile. Conclusion: Marine phages have a high potential for the use as sensitive tracers in terrestrial habitats with their surface properties playing a crucial role for their transport. Marine phages however, exhibit differences in their deposition efficiency depending on their morphology, hydrophobicity and availability.

The "Transport Specificity Ratio": a structure-function tool to search the protein fold for loci that control transition state stability in membrane transport catalysis

PubMed Central

King, Steven C

2004-01-01

Background In establishing structure-function relationships for membrane transport proteins, the interpretation of phenotypic changes can be problematic, owing to uncertainties in protein expression levels, sub-cellular localization, and protein-folding fidelity. A dual-label competitive transport assay called "Transport Specificity Ratio" (TSR) analysis has been developed that is simple to perform, and circumvents the "expression problem," providing a reliable TSR phenotype (a constant) for comparison to other transporters. Results Using the Escherichia coli GABA (4-aminobutyrate) permease (GabP) as a model carrier, it is demonstrated that the TSR phenotype is largely independent of assay conditions, exhibiting: (i) indifference to the particular substrate concentrations used, (ii) indifference to extreme changes (40-fold) in transporter expression level, and within broad limits (iii) indifference to assay duration. The theoretical underpinnings of TSR analysis predict all of the above observations, supporting that TSR has (i) applicability in the analysis of membrane transport, and (ii) particular utility in the face of incomplete information on protein expression levels and initial reaction rate intervals (e.g., in high-throughput screening situations). The TSR was used to identify gab permease (GabP) variants that exhibit relative changes in catalytic specificity (kcat/Km) for [14C]GABA (4-aminobutyrate) versus [3H]NA (nipecotic acid). Conclusions The TSR phenotype is an easily measured constant that reflects innate molecular properties of the transition state, and provides a reliable index of the difference in catalytic specificity that a carrier exhibits toward a particular pair of substrates. A change in the TSR phenotype, called a Δ(TSR), represents a specificity shift attributable to underlying changes in the intrinsic substrate binding energy (ΔGb) that translocation catalysts rely upon to decrease activation energy (). TSR analysis is therefore a structure-function tool that enables parsimonious scanning for positions in the protein fold that couple to the transition state, creating stability and thereby serving as functional determinants of catalytic power (efficiency, or specificity). PMID:15548327

Embedded Ag Grid Electrodes as Current Collector for Ultraflexible Transparent Solid-State Supercapacitor.

PubMed

Xu, Jian-Long; Liu, Yan-Hua; Gao, Xu; Sun, Yilin; Shen, Su; Cai, Xinlei; Chen, Linsen; Wang, Sui-Dong

2017-08-23

Flexible transparent solid-state supercapacitors have attracted immerse attention for the power supply of next-generation flexible "see-through" or "invisible" electronics. For fabrication of such devices, high-performance flexible transparent current collectors are highly desired. In this paper, the utilization of embedded Ag grid transparent conductive electrodes (TCEs) fabricated by a facile soft ultraviolet imprinting lithography method combined with scrap techniques, as the current collector for flexible transparent solid-state supercapacitors, is demonstrated. The embedded Ag grid TCEs exhibit not only excellent optoelectronic properties (R S ∼ 2.0 Ω sq -1 and T ∼ 89.74%) but also robust mechanical properties, which could meet the conductivity, transparency, and flexibility needs of current collectors for flexible transparent supercapacitors. The obtained supercapacitor exhibits large specific capacitance, long cycling life, high optical transparency (T ∼ 80.58% at 550 nm), high flexibility, and high stability. Owing to the embedded Ag grid TCE structure, the device shows a slight capacitance loss of 2.6% even after 1000 cycles of repetitive bending for a bending radius of up to 2.0 mm. This paves the way for developing high-performance current collectors and thus flexible transparent energy storage devices, and their general applicability opens up opportunities for flexible transparent electronics.

Enhanced kinetics of polysulfide redox reactions on Mo2C/CNT in lithium-sulfur batteries.

PubMed

Razaq, Rameez; Sun, Dan; Xin, Ying; Li, Qian; Huang, Taizhong; Zheng, Lei; Zhang, Zhaoliang; Huang, Yunhui

2018-07-20

Among different energy storage devices, the lithium-sulfur (Li-S) battery is the subject of recent attention. However, the capacity decay caused by polysulfide shuttle leading to sluggish kinetics of polysulfide redox reactions is the main hindrance for its practical application in Li-S batteries. Herein, molybdenum carbide nanoparticles anchored on carbon nanotubes (Mo 2 C/CNT) are reported to serve as an efficient cathode material to enhance the electrochemical kinetics of polysulfide conversion in Li-S batteries. Mo 2 C/CNT shows strong adsorption and activation of polar polysulfides and therefore accelerates the redox kinetics of polysulfides, reduces the energy barrier, effectively mitigates the polarization and polysulfide shuttle, thus improving the electrochemical performance. The S-Mo 2 C/CNT composite with 70 wt% sulfur loading exhibits high specific discharge capacity (1206 mA h g -1 at 0.5 C), excellent high-rate performance, long cycle life (900 cycles), and outstanding Coulombic efficiency (∼100%) at a high rate (2 C) corresponding to a capacity decay of only 0.05%. Remarkably, the S-Mo 2 C/CNT cathode with high areal sulfur loading of 2.5 mg cm -2 exhibits high-rate capacities and stable cycling performance over 100 cycles, offering the potential for use in high energy Li-S batteries.

Enhanced kinetics of polysulfide redox reactions on Mo2C/CNT in lithium–sulfur batteries

NASA Astrophysics Data System (ADS)

Razaq, Rameez; Sun, Dan; Xin, Ying; Li, Qian; Huang, Taizhong; Zheng, Lei; Zhang, Zhaoliang; Huang, Yunhui

2018-07-01

Among different energy storage devices, the lithium–sulfur (Li–S) battery is the subject of recent attention. However, the capacity decay caused by polysulfide shuttle leading to sluggish kinetics of polysulfide redox reactions is the main hindrance for its practical application in Li–S batteries. Herein, molybdenum carbide nanoparticles anchored on carbon nanotubes (Mo2C/CNT) are reported to serve as an efficient cathode material to enhance the electrochemical kinetics of polysulfide conversion in Li–S batteries. Mo2C/CNT shows strong adsorption and activation of polar polysulfides and therefore accelerates the redox kinetics of polysulfides, reduces the energy barrier, effectively mitigates the polarization and polysulfide shuttle, thus improving the electrochemical performance. The S-Mo2C/CNT composite with 70 wt% sulfur loading exhibits high specific discharge capacity (1206 mA h g‑1 at 0.5 C), excellent high-rate performance, long cycle life (900 cycles), and outstanding Coulombic efficiency (∼100%) at a high rate (2 C) corresponding to a capacity decay of only 0.05%. Remarkably, the S-Mo2C/CNT cathode with high areal sulfur loading of 2.5 mg cm‑2 exhibits high-rate capacities and stable cycling performance over 100 cycles, offering the potential for use in high energy Li–S batteries.

The effect of precipitants on Ni-Al2O3 catalysts prepared by a co-precipitation method for internal reforming in molten carbonate fuel cells

PubMed Central

Jung, You-Shick; Yoon, Wang-Lai; Seo, Yong-Seog; Rhee, Young-Woo

2012-01-01

Ni-Al2O3 catalysts are prepared via the co-precipitation method using various precipitants: urea, Na2CO3, NaOH, K2CO3, KOH and NH4OH. The effects of the precipitants on the physicochemical properties and catalytic activities of the Ni-Al2O3 catalysts are investigated. The Ni50-urea catalyst displays the largest specific surface area and the highest pore volume. This catalyst also exhibits the highest Ni dispersion and the largest Ni surface area. Ni50-urea catalyst prepared with urea as precipitant and Ni50-K2CO3 catalyst prepared with K2CO3 as precipitant exhibit high pore volumes and good catalytic activities for methane steam reforming. The Ni50-urea catalyst exhibits the best physicochemical properties and shows good catalytic activity and a strong resistance to electrolyte contamination. PMID:22962548

Spatiotemporal characteristics and vascular sources of neural-specific and -nonspecific fMRI signals at submillimeter columnar resolution

PubMed Central

Moon, Chan Hong; Fukuda, Mitsuhiro; Kim, Seong-Gi

2012-01-01

The neural specificity of hemodynamic-based functional magnetic resonance imaging (fMRI) signals are dependent on both the vascular regulation and the sensitivity of the applied fMRI technique to different types and sizes of blood vessels. In order to examine the specificity of MRI-detectable hemodynamic responses, submillimeter blood oxygenation-level dependent (BOLD) and cerebral blood volume (CBV) fMRI studies were performed in a well-established cat orientation column model at 9.4 Tesla. Neural-nonspecific and -specific signals were separated by comparing the fMRI responses of orthogonal orientation stimuli. The BOLD response was dominantly neural-nonspecific, mostly originating from pial and intracortical emerging veins, and thus was highly correlated with baseline blood volume. Uneven baseline CBV may displace or distort small functional domains in high-resolution BOLD maps. The CBV response in the parenchyma exhibited dual spatiotemporal characteristics, a fast and early neural-nonspecific response (with 4.3-s time constant) and a slightly slower and delayed neural-specific response (with 9.4-s time constant). The nonspecific CBV signal originates from early-responding arteries and arterioles, while the specific CBV response, which is not correlated with baseline blood volume, arises from late-responding microvessels including small pre-capillary arterioles and capillaries. Our data indicate that although the neural specificity of CBV fMRI signals is dependent on stimulation duration, high-resolution functional maps can be obtained from steady-state CBV studies. PMID:22960251

High frequencies of circulating IFN-gamma-secreting CD8 cytotoxic T cells specific for a novel MHC class I-restricted Mycobacterium tuberculosis epitope in M. tuberculosis-infected subjects without disease.

PubMed

Pathan, A A; Wilkinson, K A; Wilkinson, R J; Latif, M; McShane, H; Pasvol, G; Hill, A V; Lalvani, A

2000-09-01

MHC class I-restricted CD8 cytotoxic T lymphocytes (CTL) are essential for protective immunity to Mycobacterium tuberculosis in animal models but their role in humans remains unclear. We therefore studied subjects who had successfully contained M. tuberculosis infection in vivo, i.e. exposed healthy household contacts and individuals with inactive self-healed pulmonary tuberculosis. Using the ELISPOT assay for IFN-gamma, we screened peptides from ESAT-6, a secreted antigen that is highly specific for M. tuberculosis. We identified a novel nonamer epitope: unstimulated peripheral blood-derived CD8 T cells displayed peptide-specific IFN-gamma release ex vivo while CD8 T cell lines and clones exhibited HLA-A68.02-restricted cytolytic activity and recognized endogenously processed antigen. The frequency of CD8 CTL specific for this single M. tuberculosis epitope, 1/2500 peripheral blood lymphocytes, was equivalent to the combined frequency of all IFN-gamma-secreting purified protein derivative-reactive T cells ex vivo. This highly focused CTL response was maintained in an asymptomatic contact over 2 years and is the most potent antigen-specific antimycobacterial CD8 CTL response hitherto described. Thus, human M. tuberculosis-specific CD8 CTL are not necessarily associated with active disease per se. Rather, our results are consistent with a protective role for these ESAT-6-specific CD8 T cells in the long-term control of M. tuberculosis in vivo in humans.

High Gloss Corrosion-Resistant Coatings

DTIC Science & Technology

1991-08-27

removal and parts by weight of a zinc salt of a substituted benioic certainly saves on manpower that would generally be acid , and 4 to 27 pans by...system consisting essentially of zinc molybdate, zinc salt of benzoic acids , and zinc phosphate in specific ratio’s. The coating exhibits good...polymeric binder and 18 to 70 percent by weight of a pigment system consisting essen- tially of zinc molybdate. zinc salt of benzoic acids , and zinc

AgRISTARS. Preliminary technical results review of FY81 experiments, volume 2: Fiscal year 1981/1982 "corn and soybeans pilot" experiment

NASA Technical Reports Server (NTRS)

1981-01-01

The performance of the technology exhibited significant proportion estimation errors, specifically, high mean error in both corn and soybeans area estimation. The data systems, technical approaches, and data assessment of the pilot experiment were reviewed. Results of proportion estimations procedure performance evaluations, and sensitivity evaluations are presented. The role of the pilot experiment in foreign technology development is discussed.

The effect of drought on photosynthetic plasticity in Marrubium vulgare plants growing at low and high altitudes.

PubMed

Habibi, Ghader; Ajory, Neda

2015-11-01

Photosynthesis is a biological process most affected by water deficit. Plants have various photosynthetic mechanisms that are matched to specific climatic zones. We studied the photosynthetic plasticity of C3 plants at water deficit using ecotypes of Marrubium vulgare L. from high (2,200 m) and low (1,100 m) elevation sites in the Mishou-Dagh Mountains of Iran. Under experimental drought, high-altitude plants showed more tolerance to water stress based on most of the parameters studied as compared to the low-altitude plants. Increased tolerance in high-altitude plants was achieved by lower levels of daytime stomatal conductance (g s) and reduced damaging effect on maximal quantum yield of photosystem II (PSII) (F v /F m ) coupled with higher levels of carotenoids and non-photochemical quenching (NPQ). High-altitude plants exhibited higher water use efficiency (WUE) than that in low-altitude plants depending on the presence of thick leaves and the reduced daytime stomatal conductance. Additionally, we have studied the oscillation in H(+) content and diel gas exchange patterns to determine the occurrence of C3 or weak CAM (Crassulacean acid metabolism) in M. vulgare through 15 days drought stress. Under water-stressed conditions, low-altitude plants exhibited stomatal conductance and acid fluctuations characteristic of C3 photosynthesis, though high-altitude plants exhibited more pronounced increases in nocturnal acidity and phosphoenolpyruvate carboxylase (PEPC) activity, suggesting photosynthetic flexibility. These results indicated that the regulation of carotenoids, NPQ, stomatal conductance and diel patterns of CO2 exchange presented the larger differences among studied plants at different altitudes and seem to be the protecting mechanisms controlling the photosynthetic performance of M. vulgare plants under drought conditions.

Amyloid Hydrogen Bonding Polymorphism Evaluated by (15)N{(17)O}REAPDOR Solid-State NMR and Ultra-High Resolution Fourier Transform Ion Cyclotron Resonance Mass Spectrometry.

PubMed

Wei, Juan; Antzutkin, Oleg N; Filippov, Andrei V; Iuga, Dinu; Lam, Pui Yiu; Barrow, Mark P; Dupree, Ray; Brown, Steven P; O'Connor, Peter B

2016-04-12

A combined approach, using Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) and solid-state NMR (Nuclear Magnetic Resonance), shows a high degree of polymorphism exhibited by Aβ species in forming hydrogen-bonded networks. Two Alzheimer's Aβ peptides, Ac-Aβ(16-22)-NH2 and Aβ(11-25), selectively labeled with (17)O and (15)N at specific amino acid residues were investigated. The total amount of peptides labeled with (17)O as measured by FTICR-MS enabled the interpretation of dephasing observed in (15)N{(17)O}REAPDOR solid-state NMR experiments. Specifically, about one-third of the Aβ peptides were found to be involved in the formation of a specific >C═(17)O···H-(15)N hydrogen bond with their neighbor peptide molecules, and we hypothesize that the rest of the molecules undergo ± n off-registry shifts in their hydrogen bonding networks.

Electrochemical properties of graphene nanosheets/polyaniline nanofibers composites as electrode for supercapacitors

NASA Astrophysics Data System (ADS)

Li, Jing; Xie, Huaqing; Li, Yang; Liu, Jie; Li, Zhuxin

Graphene nanosheets/polyaniline nanofibers (GNS/PANI) composites are synthesized via in situ polymerization of aniline monomer in HClO 4 solution. The PANI nanofibers homogeneously coating on the surface of GNS greatly improve the charge transfer reaction. The GNS/PANI composites exhibit better electrochemical performances than the pure individual components. A remarkable specific capacitance of 1130 F g -1 (based on GNS/PANI composites) is obtained at a scan rate of 5 mV s -1 in 1 M H 2SO 4 solution compared to 402 F g -1 for pure PANI and 270 F g -1 for GNS. The excellent performance is not only due to the GNS which can provide good electrical conductivity and high specific surface area, but also associate with a good redox activity of ordered PANI nanofibers. Moreover, the GNS/PANI composites present excellent long cycle life with 87% specific capacitance retained after 1000 charge/discharge processes. The resulting composites are promising electrode materials for high-performance electrical energy storage devices.

Humic acids-based hierarchical porous carbons as high-rate performance electrodes for symmetric supercapacitors.

PubMed

Qiao, Zhi-jun; Chen, Ming-ming; Wang, Cheng-yang; Yuan, Yun-cai

2014-07-01

Two kinds of hierarchical porous carbons (HPCs) with specific surface areas of 2000 m(2)g(-1) were synthesized using leonardite humic acids (LHA) or biotechnology humic acids (BHA) precursors via a KOH activation process. Humic acids have a high content of oxygen-containing groups which enabled them to dissolve in aqueous KOH and facilitated the homogeneous KOH activation. The LHA-based HPC is made up of abundant micro-, meso-, and macropores and in 6M KOH it has a specific capacitance of 178 F g(-1) at 100 Ag(-1) and its capacitance retention on going from 0.05 to 100 A g(-1) is 64%. In contrast, the BHA-based HPC exhibits a lower capacitance retention of 54% and a specific capacitance of 157 F g(-1) at 100 A g(-1) which is due to the excessive micropores in the BHA-HPC. Moreover, LHA-HPC is produced in a higher yield than BHA-HPC (51 vs. 17 wt%). Copyright © 2014 Elsevier Ltd. All rights reserved.

Facile synthesis of hybrid CNTs/NiCo2S4 composite for high performance supercapacitors

NASA Astrophysics Data System (ADS)

Li, Delong; Gong, Youning; Pan, Chunxu

2016-07-01

In this work, a novel carbon nanotubes (CNTs)/NiCo2S4 composite for high performance supercapacitors was prepared via a simple chemical bath deposition combined with a post-anion exchange reaction. The morphologies and phase structures of the composites were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy (Raman), X-ray photoelectron spectroscopy (XPS) and low-temperature sorption of nitrogen (BET). The electro-chemical tests revealed that the CNT/NiCo2S4 composite exhibited high electrochemical performance, because the CNTs were used as a conductive network for the NiCo2S4 hexagonal nanoplates. Compared with pure NiCo2S4 and the mechanically mixed CNTs/NiCo2S4 composite, the CNTs/NiCo2S4 composite electrode material exhibited excellent supercapacitive performance, such as a high specific capacitance up to 1537 F/g (discharge current density of 1 A/g) and an outstanding rate capability of 78.1% retention as the discharge current density increased to 100 A/g. It is therefore expected to be a promising alternative material in the area of energy storage.

Wire-type MnO2/Multilayer graphene/Ni electrode for high-performance supercapacitors

NASA Astrophysics Data System (ADS)

Hu, Minglei; Liu, Yuhao; Zhang, Min; Wei, Helin; Gao, Yihua

2016-12-01

Commercially available wearable energy storage devices need a wire-type electrode with high strength, conductivity and electrochemical performance, as well as stable structure under deformation. Herein, we report a novel wire-type electrode of hierarchically structure MnO2 on Ni wire with multilayer graphene (MGr) as a buffer layer to enhance the electrical conductivity of the MnO2 and interface contact between the MnO2 and Ni wire. Thus, the wire-type MnO2/MGr/Ni electrode has a stable and high quality interface. The wire-type supercapacitor (WSC) based on wire-type MnO2/MGr/Ni electrode exhibits good electrochemical performance, high rate capability, extraordinary flexibility, and superior cycle lifetime. Length (area, volumetric) specific capacitance of the WSC reaches 6.9 mF cm-1 (73.2 mF cm-2, 9.8 F cm-3). Maximum length (volumetric) energy density of the WSC based on MnO2/MGr/Ni reaches 0.62 μWh cm-1 (0.88 mWh cm-3). Furthermore, the WSC has a short time constant (0.5-400 ms) and exhibits minimal change in capacitance under different bending shapes.

Ultrathin nickel hydroxide on carbon coated 3D-porous copper structures for high performance supercapacitors.

PubMed

Kang, Kyeong-Nam; Kim, Ik-Hee; Ramadoss, Ananthakumar; Kim, Sun-I; Yoon, Jong-Chul; Jang, Ji-Hyun

2018-01-03

An ultrathin nickel hydroxide layer electrodeposited on a carbon-coated three-dimensional porous copper structure (3D-C/Cu) is suggested as an additive and binder-free conductive electrode with short electron path distances, large electrochemical active sites, and improved structural stability, for high performance supercapacitors. The 3D-porous copper structure (3D-Cu) provides high electrical conductivity and facilitates electron transport between the Ni(OH) 2 active materials and the current collector of the Ni-plate. A carbon coating was applied to the 3D-Cu to prevent the oxidation of Cu, without degrading the electron transport behavior of the 3D-Cu. The 3D-Ni(OH) 2 /C/Cu exhibited a high specific capacitance of 1860 F g -1 at 1 A g -1 , and good cycling performance, with an 86.5% capacitance retention after 10 000 cycles. When tested in a two-electrode system, an asymmetric supercapacitor exhibited an energy density of 147.9 W h kg -1 and a power density of 37.0 kW kg -1 . These results open a new area of ultrahigh-performance supercapacitors, supported by 3D-Cu electrodes.

Facile synthesis of hybrid CNTs/NiCo2S4 composite for high performance supercapacitors

PubMed Central

Li, Delong; Gong, Youning; Pan, Chunxu

2016-01-01

In this work, a novel carbon nanotubes (CNTs)/NiCo2S4 composite for high performance supercapacitors was prepared via a simple chemical bath deposition combined with a post-anion exchange reaction. The morphologies and phase structures of the composites were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy (Raman), X-ray photoelectron spectroscopy (XPS) and low-temperature sorption of nitrogen (BET). The electro-chemical tests revealed that the CNT/NiCo2S4 composite exhibited high electrochemical performance, because the CNTs were used as a conductive network for the NiCo2S4 hexagonal nanoplates. Compared with pure NiCo2S4 and the mechanically mixed CNTs/NiCo2S4 composite, the CNTs/NiCo2S4 composite electrode material exhibited excellent supercapacitive performance, such as a high specific capacitance up to 1537 F/g (discharge current density of 1 A/g) and an outstanding rate capability of 78.1% retention as the discharge current density increased to 100 A/g. It is therefore expected to be a promising alternative material in the area of energy storage. PMID:27406239

Facile synthesis of hybrid CNTs/NiCo2S4 composite for high performance supercapacitors.

PubMed

Li, Delong; Gong, Youning; Pan, Chunxu

2016-07-11

In this work, a novel carbon nanotubes (CNTs)/NiCo2S4 composite for high performance supercapacitors was prepared via a simple chemical bath deposition combined with a post-anion exchange reaction. The morphologies and phase structures of the composites were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy (Raman), X-ray photoelectron spectroscopy (XPS) and low-temperature sorption of nitrogen (BET). The electro-chemical tests revealed that the CNT/NiCo2S4 composite exhibited high electrochemical performance, because the CNTs were used as a conductive network for the NiCo2S4 hexagonal nanoplates. Compared with pure NiCo2S4 and the mechanically mixed CNTs/NiCo2S4 composite, the CNTs/NiCo2S4 composite electrode material exhibited excellent supercapacitive performance, such as a high specific capacitance up to 1537 F/g (discharge current density of 1 A/g) and an outstanding rate capability of 78.1% retention as the discharge current density increased to 100 A/g. It is therefore expected to be a promising alternative material in the area of energy storage.

A reduced graphene oxide/Co 3O 4 composite for supercapacitor electrode

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

Xiang, Chengcheng; Li, Ming; Zhi, Mingjia

2013-03-01

20 nm sized Co 3O 4 nanoparticles are in-situ grown on the chemically reduced graphene oxide (rGO) sheets to form a rGO-Co 3O 4 composite during hydrothermal processing. The rGO-Co 3O 4 composite is employed as the pseudocapacitor electrode in the 2 M KOH aqueous electrolyte solution. The rGOCo 3O 4 composite electrode exhibits a specific capacitance of 472 F/g at a scan rate of 2 mV/s in a two-electrode cell. 82.6% of capacitance is retained when the scan rate increases to 100 mV/s. The rGOCo 3O 4 composite electrode shows high rate capability and excellent long-term stability. It alsomore » exhibits high energy density at relatively high power density. The energy density reaches 39.0 Wh/kg at a power density of 8.3 kW/kg. The super performance of the composite electrode is attributed to the synergistic effects of small size and good redox activity of the Co 3O 4 particles combined with high electronic conductivity of the rGO sheets.« less

Effect of surface microstructure on electrochemical performance of garnet solid electrolytes.

PubMed

Cheng, Lei; Chen, Wei; Kunz, Martin; Persson, Kristin; Tamura, Nobumichi; Chen, Guoying; Doeff, Marca

2015-01-28

Cubic garnet phases based on Al-substituted Li7La3Zr2O12 (LLZO) have high ionic conductivities and exhibit good stability versus metallic lithium, making them of particular interest for use in next-generation rechargeable battery systems. However, high interfacial impedances have precluded their successful utilization in such devices until the present. Careful engineering of the surface microstructure, especially the grain boundaries, is critical to achieving low interfacial resistances and enabling long-term stable cycling with lithium metal. This study presents the fabrication of LLZO heterostructured solid electrolytes, which allowed direct correlation of surface microstructure with the electrochemical characteristics of the interface. Grain orientations and grain boundary distributions of samples with differing microstructures were mapped using high-resolution synchrotron polychromatic X-ray Laue microdiffraction. The electrochemical characteristics are strongly dependent upon surface microstructure, with small grained samples exhibiting much lower interfacial resistances and better cycling behavior than those with larger grain sizes. Low area specific resistances of 37 Ω cm(2) were achieved; low enough to ensure stable cycling with minimal polarization losses, thus removing a significant obstacle toward practical implementation of solid electrolytes in high energy density batteries.

Nanostructure selenium compounds as pseudocapacitive electrodes for high-performance asymmetric supercapacitor.

PubMed

Ma, Guofu; Hua, Fengting; Sun, Kanjun; Fenga, Enke; Peng, Hui; Zhang, Zhiguo; Lei, Ziqiang

2018-01-01

The electrochemical performance of an energy conversion and storage device like the supercapacitor mainly depends on the microstructure and morphology of the electrodes. In this paper, to improve the capacitance performance of the supercapacitor, the all-pseudocapacitive electrodes of lamella-like Bi 18 SeO 29 /BiSe as the negative electrode and flower-like Co 0.85 Se nanosheets as the positive electrode are synthesized by using a facile low-temperature one-step hydrothermal method. The microstructures and morphology of the electrode materials are carefully characterized, and the capacitance performances are also tested. The Bi 18 SeO 29 /BiSe and Co 0.85 Se have high specific capacitance (471.3 F g -1 and 255 F g -1 at 0.5 A g -1 ), high conductivity, outstanding cycling stability, as well as good rate capability. The assembled asymmetric supercapacitor completely based on the pseudocapacitive electrodes exhibits outstanding cycling stability (about 93% capacitance retention after 5000 cycles). Moreover, the devices exhibit high energy density of 24.2 Wh kg -1 at a power density of 871.2 W kg -1 in the voltage window of 0-1.6 V with 2 M KOH solution.

Children’s Inferential Styles, 5-HTTLPR Genotype, and Maternal Expressed Emotion-Criticism: An Integrated Model for the Intergenerational Transmission of Depression

PubMed Central

Gibb, Brandon E.; Uhrlass, Dorothy J.; Grassia, Marie; Benas, Jessica S.; McGeary, John

2010-01-01

We tested a model for the intergenerational transmission of depression integrating specific genetic (5-HTTLPR), cognitive (inferential style), and environmental (mother depressive symptoms and expressed-emotion criticism) risk factors. Supporting the hypothesis that maternal depression is associated with elevated levels of stress in children’s lives, mothers with a history of major depressive disorder (MDD) exhibited higher depressive symptoms across a 6-month multi-wave follow-up than mothers with no depression history. In addition, partially supporting our hypothesis, levels of maternal criticism during the follow-up were significantly related to mothers’ current depressive symptoms, but not history of MDD. Finally, we found support for an integrated gene × cognition × environment model of risk. Specifically, among children with negative inferential styles regarding their self-characteristics, there was a clear dose response of 5-HTTLPR genotype moderating the relation between maternal criticism and children’s depressive symptoms, with the highest depressive symptoms during the follow-up observed among children carrying two copies of the 5-HTTLPR lower expressing alleles (S or LG) who also exhibited negative inferential styles for self-characteristics and who experienced high levels of EE-Crit. In contrast, children with positive inferential styles exhibited low depressive symptoms regardless of 5-HTTLPR genotype or level of maternal criticism. PMID:19899843

Children's inferential styles, 5-HTTLPR genotype, and maternal expressed emotion-criticism: An integrated model for the intergenerational transmission of depression.

PubMed

Gibb, Brandon E; Uhrlass, Dorothy J; Grassia, Marie; Benas, Jessica S; McGeary, John

2009-11-01

The authors tested a model for the intergenerational transmission of depression integrating specific genetic (5-HTTLPR), cognitive (inferential style), and environmental (mother depressive symptoms and expressed-emotion criticism [EE-Crit]) risk factors. Supporting the hypothesis that maternal depression is associated with elevated levels of stress in children's lives, mothers with a history of major depressive disorder (MDD) exhibited higher depressive symptoms across a 6-month multiwave follow-up than mothers with no depression history. In addition, partially supporting our hypothesis, levels of maternal criticism during the follow-up were significantly related to mothers' current depressive symptoms but not to history of MDD. Finally, the authors found support for an integrated Gene x Cognition x Environment model of risk. Specifically, among children with negative inferential styles regarding their self-characteristics, there was a clear dose response of 5-HTTLPR genotype moderating the relation between maternal criticism and children's depressive symptoms, with the highest depressive symptoms during the follow-up observed among children carrying 2 copies of the 5-HTTLPR lower expressing alleles (short [S] or long [LG]) who also exhibited negative inferential styles for self-characteristics and who experienced high levels of EE-Crit. In contrast, children with positive inferential styles exhibited low depressive symptoms regardless of 5-HTTLPR genotype or level of maternal criticism. PsycINFO Database Record 2009 APA, all rights reserved.

Improving specific activity and thermostability of Escherichia coli phytase by structure-based rational design.

PubMed

Wu, Tzu-Hui; Chen, Chun-Chi; Cheng, Ya-Shan; Ko, Tzu-Ping; Lin, Cheng-Yen; Lai, Hui-Lin; Huang, Ting-Yung; Liu, Je-Ruei; Guo, Rey-Ting

2014-04-10

Escherichia coli phytase (EcAppA) which hydrolyzes phytate has been widely applied in the feed industry, but the need to improve the enzyme activity and thermostability remains. Here, we conduct rational design with two strategies to enhance the EcAppA performance. First, residues near the substrate binding pocket of EcAppA were modified according to the consensus sequence of two highly active Citrobacter phytases. One out of the eleven mutants, V89T, exhibited 17.5% increase in catalytic activity, which might be a result of stabilized protein folding. Second, the EcAppA glycosylation pattern was modified in accordance with the Citrobacter phytases. An N-glycosylation motif near the substrate binding site was disrupted to remove spatial hindrance for phytate entry and product departure. The de-glycosylated mutants showed 9.6% increase in specific activity. On the other hand, the EcAppA mutants that adopt N-glycosylation motifs from CbAppA showed improved thermostability that three mutants carrying single N-glycosylation motif exhibited 5.6-9.5% residual activity after treatment at 80°C (1.8% for wild type). Furthermore, the mutant carrying all three glycosylation motifs exhibited 27% residual activity. In conclusion, a successful rational design was performed to obtain several useful EcAppA mutants with better properties for further applications. Copyright © 2014 Elsevier B.V. All rights reserved.

Preschoolers with Down Syndrome Do Not yet Show the Learning and Memory Impairments Seen in Adults with Down Syndrome

ERIC Educational Resources Information Center

Roberts, Lynette V.; Richmond, Jenny L.

2015-01-01

Individuals with Down syndrome (DS) exhibit a behavioral phenotype of specific strengths and weaknesses, in addition to a generalized cognitive delay. In particular, adults with DS exhibit specific deficits in learning and memory processes that depend on the hippocampus, and there is some suggestion of impairments on executive function tasks that…

High Energy Density Asymmetric Supercapacitor Based on NiOOH/Ni3S2/3D Graphene and Fe3O4/Graphene Composite Electrodes

PubMed Central

Lin, Tsung-Wu; Dai, Chao-Shuan; Hung, Kuan-Chung

2014-01-01

The application of the composite of Ni3S2 nanoparticles and 3D graphene as a novel cathode material for supercapacitors is systematically investigated in this study. It is found that the electrode capacitance increases by up to 111% after the composite electrode is activated by the consecutive cyclic voltammetry scanning in 1 M KOH. Due to the synergistic effect, the capacitance and the diffusion coefficient of electrolyte ions of the activated composite electrode are ca. 3.7 and 6.5 times higher than those of the Ni3S2 electrode, respectively. Furthermore, the activated composite electrode exhibits an ultrahigh specific capacitance of 3296 F/g and great cycling stability at a current density of 16 A/g. To obtain the reasonable matching of cathode/anode electrodes, the composite of Fe3O4 nanoparticles and chemically reduced graphene oxide (Fe3O4/rGO) is synthesized as the anode material. The Fe3O4/rGO electrode exhibits the specific capacitance of 661 F/g at 1 A/g and excellent rate capability. More importantly, an asymmetric supercapacitor fabricated by two different composite electrodes can be operated reversibly between 0 and 1.6 V and obtain a high specific capacitance of 233 F/g at 5 mV/s, which delivers a maximum energy density of 82.5 Wh/kg at a power density of 930 W/kg. PMID:25449978

Regulator and enzyme specificities of the TOL plasmid-encoded upper pathway for degradation of aromatic hydrocarbons and expansion of the substrate range of the pathway.

PubMed Central

Abril, M A; Michan, C; Timmis, K N; Ramos, J L

1989-01-01

The TOL plasmid upper pathway operon encodes enzymes involved in the catabolism of aromatic hydrocarbons such as toluene and xylenes. The regulator of the gene pathway, the XylR protein, exhibits a very broad effector specificity, being able to recognize as effectors not only pathway substrates but also a wide variety of mono- and disubstituted methyl-, ethyl-, and chlorotoluenes, benzyl alcohols, and p-chlorobenzaldehyde. Benzyl alcohol dehydrogenase and benzaldehyde dehydrogenase, two upper pathway enzymes, exhibit very broad substrate specificities and transform unsubstituted substrates and m- and p-methyl-, m- and p-ethyl-, and m- and p-chloro-substituted benzyl alcohols and benzaldehydes, respectively, at a high rate. In contrast, toluene oxidase only oxidizes toluene, m- and p-xylene, m-ethyltoluene, and 1,2,4-trimethylbenzene [corrected], also at a high rate. A biological test showed that toluene oxidase attacks m- and p-chlorotoluene, albeit at a low rate. No evidence for the transformation of p-ethyltoluene by toluene oxidase has been found. Hence, toluene oxidase acts as the bottleneck step for the catabolism of p-ethyl- and m- and p-chlorotoluene through the TOL upper pathway. A mutant toluene oxidase able to transform p-ethyltoluene was isolated, and a mutant strain capable of fully degrading p-ethyltoluene was constructed with a modified TOL plasmid meta-cleavage pathway able to mineralize p-ethylbenzoate. By transfer of a TOL plasmid into Pseudomonas sp. strain B13, a clone able to slowly degrade m-chlorotoluene was also obtained. PMID:2687253

Magnetic nanoparticles with high specific absorption rate of electromagnetic energy at low field strength for hyperthermia therapy

NASA Astrophysics Data System (ADS)

Shubitidze, Fridon; Kekalo, Katsiaryna; Stigliano, Robert; Baker, Ian

2015-03-01

Magnetic nanoparticles (MNPs), referred to as the Dartmouth MNPs, which exhibit high specific absorption rate at low applied field strength have been developed for hyperthermia therapy applications. The MNPs consist of small (2-5 nm) single crystals of gamma-Fe2O3 with saccharide chains implanted in their crystalline structure, forming 20-40 nm flower-like aggregates with a hydrodynamic diameter of 110-120 nm. The MNPs form stable (>12 months) colloidal solutions in water and exhibit no hysteresis under an applied quasistatic magnetic field, and produce a significant amount of heat at field strengths as low as 100 Oe at 99-164 kHz. The MNP heating mechanisms under an alternating magnetic field (AMF) are discussed and analyzed quantitatively based on (a) the calculated multi-scale MNP interactions obtained using a three dimensional numerical model called the method of auxiliary sources, (b) measured MNP frequency spectra, and (c) quantified MNP friction losses based on magneto-viscous theory. The frequency responses and hysteresis curves of the Dartmouth MNPs are measured and compared to the modeled data. The specific absorption rate of the particles is measured at various AMF strengths and frequencies, and compared to commercially available MNPs. The comparisons demonstrate the superior heating properties of the Dartmouth MNPs at low field strengths (<250 Oe). This may extend MNP hyperthermia therapy to deeper tumors that were previously non-viable targets, potentially enabling the treatment of some of the most difficult cancers, such as pancreatic and rectal cancers, without damaging normal tissue.

Magnetic nanoparticles with high specific absorption rate of electromagnetic energy at low field strength for hyperthermia therapy.

PubMed

Shubitidze, Fridon; Kekalo, Katsiaryna; Stigliano, Robert; Baker, Ian

2015-03-07

Magnetic nanoparticles (MNPs), referred to as the Dartmouth MNPs, which exhibit high specific absorption rate at low applied field strength have been developed for hyperthermia therapy applications. The MNPs consist of small (2-5 nm) single crystals of gamma-Fe 2 O 3 with saccharide chains implanted in their crystalline structure, forming 20-40 nm flower-like aggregates with a hydrodynamic diameter of 110-120 nm. The MNPs form stable (>12 months) colloidal solutions in water and exhibit no hysteresis under an applied quasistatic magnetic field, and produce a significant amount of heat at field strengths as low as 100 Oe at 99-164 kHz. The MNP heating mechanisms under an alternating magnetic field (AMF) are discussed and analyzed quantitatively based on (a) the calculated multi-scale MNP interactions obtained using a three dimensional numerical model called the method of auxiliary sources, (b) measured MNP frequency spectra, and (c) quantified MNP friction losses based on magneto-viscous theory. The frequency responses and hysteresis curves of the Dartmouth MNPs are measured and compared to the modeled data. The specific absorption rate of the particles is measured at various AMF strengths and frequencies, and compared to commercially available MNPs. The comparisons demonstrate the superior heating properties of the Dartmouth MNPs at low field strengths (<250 Oe). This may extend MNP hyperthermia therapy to deeper tumors that were previously non-viable targets, potentially enabling the treatment of some of the most difficult cancers, such as pancreatic and rectal cancers, without damaging normal tissue.

Conducting polymer functionalized single-walled carbon nanotube based chemiresistive biosensor for the detection of human cardiac myoglobin

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

Puri, Nidhi; Department of Physics, Faculty of Natural Sciences, Jamia Millia Islamia, New Delhi 110025; Niazi, Asad

2014-10-13

We report the fabrication of a single-walled carbon nanotube (SWNT) based ultrasensitive label-free chemiresistive biosensor for the detection of human cardiac biomarker, myoglobin (Ag-cMb). Poly(pyrrole-co-pyrrolepropylic acid) with pendant carboxyl groups was electrochemically deposited on electrophoretically aligned SWNT channel, as a conducting linker, for biomolecular immobilization of highly specific cardiac myoglobin antibody. The device was characterized by scanning electron microscopy, source-drain current-voltage (I-V), and charge-transfer characteristic studies. The device exhibited a linear response with a change in conductance in SWNT channel towards the target, Ag-cMb, over the concentration range of 1.0 to 1000 ng ml{sup −1} with a sensitivity of ∼118% per decademore » with high specificity.« less

Few layered vanadyl phosphate nano sheets-MWCNT hybrid as an electrode material for supercapacitor application

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

Dutta, Shibsankar; De, Sukanta, E-mail: sukanta.physics@presiuniv.ac.in

It have been already seen that 2-dimensional nano materials are the suitable choice for the supercapacitor application due to their large specific surface area, electrochemical active sites, micromechanical flexibility, expedite ion migration channel properties. Free standing hybrid films of functionalized MWCNT (– COOH group) and α-Vanadyl phosphates (VOPO{sub 4}2H{sub 2}O) are prepared by vacuum filtering. The surface morphology and microstructure of the samples are studied by transmission electron microscope, field emission scanning electron microscope, XRD, Electrochemical properties of hybrid films have been investigated systematically in 1M Na{sub 2}SO{sub 4} aqueous electrolyte. The hybrid material exhibits a high specific capacitance 236more » F/g with high energy density of 65.6 Wh/Kg and a power density of 1476 W/Kg.« less

Cheap, High-Performance, and Wearable Mn Oxide Supercapacitors with Urea-LiClO4 Based Gel Electrolytes.

PubMed

Deng, Ming-Jay; Chen, Kai-Wen; Che, Yo-Cheng; Wang, I-Ju; Lin, Chih-Ming; Chen, Jin-Ming; Lu, Kueih-Tzu; Liao, Yen-Fa; Ishii, Hirofumi

2017-01-11

Here we report a simple, scalable, and low-cost method to enhance the electrochemical properties of Mn oxide electrodes for highly efficient and flexible symmetrical supercapacitors. The method involving printing on a printer, pencil-drawing, and electrodeposition is established to fabricate Mn oxide/Ni-nanotube/graphite/paper hybrid electrodes operating with a low-cost, novel urea-LiClO 4 /PVA as gel electrolyte for flexible solid-state supercapacitor (FSSC) devices. The Mn oxide nanofiber/Ni-nanotube/graphite/paper (MNNGP) electrodes in urea-LiClO 4 /PVA gel electrolyte show specific capacitance (C sp ) 960 F/g in voltage region 0.8 V at 5 mV/s and exhibit excellent rates of capacitance retention more than 85% after 5000 cycles. Moreover, the electrochemical behavior of the MNNGP electrodes in urea-LiClO 4 /PVA at operating temperatures 27-110 °C was investigated; the results show that the MNNGP electrodes in urea-LiClO 4 /PVA exhibit outstanding performance (1100 F/g), even at 90 °C. The assembled FSSC devices based on the MNNGP electrodes in urea-LiClO 4 /PVA exhibit great C sp (380 F/g in potential region of 2.0 V at 5 mV/s, exhibiting superior energy density 211.1 W h/kg) and great cycle stability (less than 15% loss after 5000 cycles at 25 mV/s). The oxidation-state change was examined by in situ X-ray absorption spectroscopy. FSSC devices would open new opportunities in developing novel portable, wearable, and roll-up electric devices owing to the cheap, high-performance, wide range of operating temperature, and simple procedures for large-area fabrication.

Charge storage in β-FeSi2 nanoparticles

NASA Astrophysics Data System (ADS)

Theis, Jens; Bywalez, Robert; Küpper, Sebastian; Lorke, Axel; Wiggers, Hartmut

2015-02-01

We report on the observation of a surprisingly high specific capacitance of β-FeSi2 nanoparticle layers. Lateral, interdigitated capacitor structures were fabricated on thermally grown silicon dioxide and covered with β-FeSi2 particles by drop or spin casting. The β-FeSi2-nanoparticles, with crystallite sizes in the range of 10-30 nm, were fabricated by gas phase synthesis in a hot wall reactor. Compared to the bare electrodes, the nanoparticle-coated samples exhibit a 3-4 orders of magnitude increased capacitance. Time-resolved current voltage measurements show that for short times (seconds to minutes), the material is capable of storing up to 1 As/g at voltages of around 1 V. The devices are robust and exhibit long-term stability under ambient conditions. The specific capacitance is highest for a saturated relative humidity, while for a relative humidity below 40% the capacitance is almost indistinguishable from a nanoparticle-free reference sample. The devices work without the need of a fluid phase, the charge storing material is abundant and cost effective, and the sample design is easy to fabricate.

The Clinical Characteristics of Anisakis Allergy in Korea

PubMed Central

Choi, Sung-Jin; Lee, Jae-Chun; Kim, Moo-Jung; Hur, Gyu-Young; Shin, Seung-Youp

2009-01-01

Anisakidae larvae can cause anisakiasis when ingested by humans. Although several groups have reported a gastrointestinal Anisakis allergy among people in Spain and Japan, our report is the first to summarize the clinical features of 10 Anisakis allergy cases in Korea. We enrolled 10 Korean patients (6 men and 4 women) who complained of aggravated allergic symptoms after ingesting raw fish or seafood. Sensitization to Anisakis was confirmed by detecting serum specific IgE to Anisakis simplex. The most common manifestation of anisakiasis was urticaria (100%), followed by abdominal pain (30%) and anaphylaxis (30%). All patients presenting with these symptoms also exhibited high serum specific IgE (0.45 to 100 kU/L) to A. simplex. Nine patients (90%) exhibited atopy and increased total serum IgE levels. The fish species suspected of carrying the Anisakis parasite were flatfish (40%), congers (40%), squid (30%), whelk (10%), and tuna (10%). Anisakis simplex should be considered as a possible causative food allergen in adult patients presenting with urticaria, angioedema, and anaphylaxis following the consumption of raw fish or seafood. PMID:19543498

The clinical characteristics of Anisakis allergy in Korea.

PubMed

Choi, Sung-Jin; Lee, Jae-Chun; Kim, Moo-Jung; Hur, Gyu-Young; Shin, Seung-Youp; Park, Hae-Sim

2009-06-01

Anisakidae larvae can cause anisakiasis when ingested by humans. Although several groups have reported a gastrointestinal Anisakis allergy among people in Spain and Japan, our report is the first to summarize the clinical features of 10 Anisakis allergy cases in Korea. We enrolled 10 Korean patients (6 men and 4 women) who complained of aggravated allergic symptoms after ingesting raw fish or seafood. Sensitization to Anisakis was confirmed by detecting serum specific IgE to Anisakis simplex. The most common manifestation of anisakiasis was urticaria (100%), followed by abdominal pain (30%) and anaphylaxis (30%). All patients presenting with these symptoms also exhibited high serum specific IgE (0.45 to 100 kU/L) to A. simplex. Nine patients (90%) exhibited atopy and increased total serum IgE levels. The fish species suspected of carrying the Anisakis parasite were flatfish (40%), congers (40%), squid (30%), whelk (10%), and tuna (10%). Anisakis simplex should be considered as a possible causative food allergen in adult patients presenting with urticaria, angioedema, and anaphylaxis following the consumption of raw fish or seafood.

High performance asymmetric supercapacitor based on molybdenum disulphide/graphene foam and activated carbon from expanded graphite.

PubMed

Masikhwa, Tshifhiwa M; Madito, Moshawe J; Bello, Abdulhakeem; Dangbegnon, Julien K; Manyala, Ncholu

2017-02-15

Molybdenum disulphide which has a graphene-like single layer structure has excellent mechanical and electrical properties and unique morphology, which might be used with graphene foam as composite in supercapacitor applications. In this work, Molybdenum disulphide (MoS 2 )/graphene foam (GF) composites with different graphene foam loading were synthesized by the hydrothermal process to improve on specific capacitance of the composites. Asymmetric supercapacitor device was fabricated using the best performing MoS 2 /GF composite and activated carbon derived from expanded graphite (AEG) as positive and negative electrodes, respectively, in 6M KOH electrolyte. The asymmetric MoS 2 /GF//AEG device exhibited a maximum specific capacitance of 59Fg -1 at a current density of 1Ag -1 with maximum energy and power densities of 16Whkg -1 and 758Wkg -1 , respectively. The supercapacitor also exhibited a good cyclic stability with 95% capacitance retention over 2000 constant charge-discharge cycles. The results obtained demonstrate the potential of MoS 2 /GF//AEG as a promising material for electrochemical energy storage application. Copyright © 2016 Elsevier Inc. All rights reserved.

Fluorene-Based Conjugated Microporous Polymers: Preparation and Chemical Sensing Application.

PubMed

Zhang, Qiujing; Yu, Sen; Wang, Qian; Xiao, Qin; Yue, Yong; Ren, Shijie

2017-12-01

Conjugated microporous polymers (CMPs) with strong fluorescence are great candidates for optoelectronic applications such as photocatalysis and chemical sensing. A series of novel fluorene-based conjugated microporous polymers (FCMPs) with different electronic structures are prepared by Yamamoto coupling reactions using rationally designed monomers. The FCMPs show a high degree of microporosity, decent specific surface areas, and variable fluorescence. FCMP3, which possesses a triazine knot in the network, exhibits the highest specific surface area of 489 m 2 g -1 , the largest pore volume of 0.30 cm 3 g -1 , and the highest solid-state photoluminescence quantum yield of 11.46%. Chemical sensing performance of FCMPs is studied using a range of nitroaromatic compounds as the analytes. Among the FCMPs, FCMP3 exhibits the highest Stern-Volmer constants of 2541, 4708, and 5241 m -1 for the detection of nitrobenzene, 4-nitrotoluene, 2,4-dinitrotoluene, respectively, which are comparable to the detecting efficiency of the state-of-the-art CMP-based sensing agents. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Targeted binding of the M13 bacteriophage to thiamethoxam organic crystals.

PubMed

Cho, Whirang; Fowler, Jeffrey D; Furst, Eric M

2012-04-10

Phage display screening with a combinatorial library was used to identify M13-type bacteriophages that express peptides with selective binding to organic crystals of thiamethoxam. The six most strongly binding phages exhibit at least 1000 times the binding affinity of wild-type M13 and express heptapeptide sequences that are rich in hydrophobic, hydrogen-bonding amino acids and proline. Among the peptide sequences identified, M13 displaying the pIII domain heptapeptide ASTLPKA exhibits the strongest binding to thiamethoxam in competitive binding assays. Electron and confocal microscopy confirm the specific binding affinity of ASTLPKA to thiamethoxam. Using atomic force microscope (AFM) probes functionalized with ASTLPKA expressing phage, we found that the average adhesion force between the bacteriophage and a thiamethoxam surface is 1.47 ± 0.80 nN whereas the adhesion force of wild-type M13KE phage is 0.18 ± 0.07 nN. Such a strongly binding bacteriophage could be used to modify the surface chemistry of thiamethoxam crystals and other organic solids with a high degree of specificity. © 2012 American Chemical Society

Role of reactive oxygen species in the anticancer activity of botanicals: Comparing sensitivity profiles

PubMed Central

Cohen, Zoya; Maimon, Yair; Samuels, Noah; Berger, Raanan

2017-01-01

Numerous botanicals have been shown to exhibit in vitro and in vivo anticancer activity, some of which is the result of the induction of reactive oxygen species (ROS) in cancer cells with a high ROS content. The present study compared sensitivities to a series of botanicals among cancer cell lines, using an XTT viability test, in order to create a specific cancer-herb profile. Of the 27 botanicals screened, 10 exhibited a cytotoxic effect, 7 of which were ROS-mediated. The sensitivity profiles of the ROS-inducing botanicals in 10 cancer cell lines were similar, unlike 3 cytotoxic ROS-independent botanicals that displayed divergent botanical-specific profiles. The correlation between sensitivity profiles of ROS-inducing botanicals suggests a common mechanism of action, in contrast to the varied mechanism of ROS-independent botanicals. This implies that the investigation of the anticancer activity of botanicals should start with the examination of ROS-mediated activity. Further investigation of ROS sensitivity among various tumor types is required in order to guide research into developing evidence-based guidelines in the use of botanicals for cancer treatment. PMID:28454445

Engineered Biomimetic Polymers as Tunable Agents for Controlling CaCO₃ Mineralization

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

Chen, Chun-Long; Qi, Jiahui; Zuckermann, Ronald N.

2011-01-01

In nature, living organisms use peptides and proteins to precisely control the nucleation and growth of inorganic minerals and sequester CO₂ via mineralization of CaCO₃. Here we report the exploitation of a novel class of sequence-specific non-natural polymers called peptoids as tunable agents that dramatically control CaCO₃ mineralization. We show that amphiphilic peptoids composed of hydrophobic and anionic monomers exhibit both a high degree of control over calcite growth morphology and an unprecedented 23-fold acceleration of growth at a peptoid concentration of only 50 nM, while acidic peptides of similar molecular weight exhibited enhancement factors of only ~2 or less.more » We further show that both the morphology and rate controls depend on peptoid sequence, side-chain chemistry, chain length, and concentration. These findings provide guidelines for developing sequence-specific non-natural polymers that mimic the functions of natural peptides or proteins in their ability to direct mineralization of CaCO₃, with an eye toward their application to sequestration of CO₂ through mineral trapping.« less

Three Dimensional Nitrogen-Doped and Nitrogen, Sulfur-Codoped Graphene Hydrogels for Electrode Materials in Supercapacitors.

PubMed

Yuan, Zhao; Qiao, Fei; Wang, Guiqiang; Zhou, Jin; Cui, Hongyou; Zhuo, Shuping; Xing, Ling-Bao

2018-08-01

In present work, reduced graphene oxide hydrogels (RGOHs) with three-dimensional (3D) porous structure are prepared through chemical reduction method by using aminourea (NRGOHs) and aminothiourea (NSRGOHs) as reductants. The as-prepared RGOHs are considered not only as promising electrode materials for supercapacitors, but also the doping of nitrogen (aminourea, NRGOHs) or nitrogen/sulfur (aminothiourea, NSRGOHs) can improve electrochemical performance through faradaic pseudocapacitance. The optimized samples have been prepared by controlling the mass ratios of graphene oxide (GO) to aminourea or aminothiourea to be 1:1, 1:2 and 1:5, respectively. With adding different amounts of aminourea or aminothiourea, the obtained RGOHs exhibited different electrochemical performance in supercapacitors. With increasing the dosage of the reductants, the RGOHs revealed better specific capacitances. Moreover, NSRGOHs with nitrogen, sulfur-codoping exhibited better capacitance performance than that of NRGOHs with only nitrogen-doping. NSRGOHs showed excellent capacitive performance with a very high specific capacitance up to 232.2, 323.3 and 345.6 F g-1 at 0.2 A g-1, while NRGOHs showed capacitive performance with specific capacitance up to 220.6, 306.5 and 332.7 F g-1 at 0.2 A g-1. This provides a strategy to improve the capacitive properties of RGOHs significantly by controlling different doping the materials.

PEGylated DX-1000: pharmacokinetics and antineoplastic activity of a specific plasmin inhibitor.

PubMed

Devy, Laetitia; Rabbani, Shafaat A; Stochl, Mark; Ruskowski, Mary; Mackie, Ian; Naa, Laurent; Toews, Mark; van Gool, Reinoud; Chen, Jie; Ley, Art; Ladner, Robert C; Dransfield, Daniel T; Henderikx, Paula

2007-11-01

Novel inhibitors of the urokinase-mediated plasminogen (plg) activation system are potentially of great clinical benefit as anticancer treatments. Using phage display, we identified DX-1000 a tissue factor pathway inhibitor-derived Kunitz domain protein which is a specific high-affinity inhibitor of plasmin (pln) (K(i) = 99 pM). When tested in vitro, DX-1000 blocks plasmin-mediated pro-matrix metalloproteinase-9 (proMMP-9) activation on cells and dose-dependently inhibits tube formation, while not significantly affecting hemostasis and coagulation. However, this low-molecular weight protein inhibitor ( approximately 7 kDa) exhibits rapid plasma clearance in mice and rabbits, limiting its potential clinical use in chronic diseases. After site-specific PEGylation, DX-1000 retains its activity and exhibits a decreased plasma clearance. This PEGylated derivative is effective in vitro, as well as potent in inhibiting tumor growth of green fluorescent protein (GFP)-labeled MDA-MB-231 cells. 4PEG-DX-1000 treatment causes a significant reduction of urokinase-type plasminogen activator (uPA) and plasminogen expressions, a reduction of tumor proliferation, and vascularization. 4PEG-DX-1000 treatment significantly decreases the level of active mitogen-activated protein kinase (MAPK) in the primary tumors and reduces metastasis incidence. Together, our results demonstrate the potential value of plasmin inhibitors as therapeutic agents for blocking breast cancer growth and metastasis.

Enhanced electrochromic and energy storage performance in mesoporous WO3 film and its application in a bi-functional smart window.

PubMed

Wang, Wei-Qi; Wang, Xiu-Li; Xia, Xin-Hui; Yao, Zhu-Jun; Zhong, Yu; Tu, Jiang-Ping

2018-05-03

Construction of multifunctional photoelectrochemical energy devices is of great importance to energy saving. In this study, we have successfully prepared a mesoporous WO3 film on FTO glass via a facile dip-coating sol-gel method; the designed mesoporous WO3 film exhibited advantages including high transparency, good adhesion and high porosity. Also, multifunctional integrated energy storage and optical modulation ability are simultaneously achieved by the mesoporous WO3 film. Impressively, the mesoporous WO3 film exhibits a noticeable electrochromic energy storage performance with a large optical modulation up to 75.6% at 633 nm, accompanied by energy storage with a specific capacity of 75.3 mA h g-1. Furthermore, a full electrochromic energy storage window assembled with the mesoporous WO3 anode and PANI nanoparticle cathode is demonstrated with large optical modulation and good long-term stability. Our research provides a new route to realize the coincident utilization of optical-electrochemical energy.

Cardiomyocytes from phorbol myristate acetate-activated mesenchymal stem cells restore electromechanical function in infarcted rat hearts

PubMed Central

Song, Heesang; Hwang, Hye Jin; Chang, Woochul; Song, Byeong-Wook; Cha, Min-Ji; Lim, Soyeon; Choi, Eun Ju; Ham, Onju; Lee, Chang Youn; Park, Jun-Hee; Lee, Se-Yeon; Choi, Eunmi; Lee, Chungkeun; Lee, Myoungho; Lee, Moon-Hyoung; Kim, Sung-Hou; Jang, Yangsoo; Hwang, Ki-Chul

2011-01-01

Despite the safety and feasibility of mesenchymal stem cell (MSC) therapy, an optimal cell type has not yet emerged in terms of electromechanical integration in infarcted myocardium. We found that poor to moderate survival benefits of MSC-implanted rats were caused by incomplete electromechanical integration induced by tissue heterogeneity between myocytes and engrafted MSCs in the infarcted myocardium. Here, we report the development of cardiogenic cells from rat MSCs activated by phorbol myristate acetate, a PKC activator, that exhibited high expressions of cardiac-specific markers and Ca2+ homeostasis-related proteins and showed adrenergic receptor signaling by norepinephrine. Histological analysis showed high connexin 43 coupling, few inflammatory cells, and low fibrotic markers in myocardium implanted with these phorbol myristate acetate-activated MSCs. Infarct hearts implanted with these cells exhibited restoration of conduction velocity through decreased tissue heterogeneity and improved myocardial contractility. These findings have major implications for the development of better cell types for electromechanical integration of cell-based treatment for infarcted myocardium. PMID:21173226

Geopotential Error Analysis from Satellite Gradiometer and Global Positioning System Observables on Parallel Architecture

NASA Technical Reports Server (NTRS)

Schutz, Bob E.; Baker, Gregory A.

1997-01-01

The recovery of a high resolution geopotential from satellite gradiometer observations motivates the examination of high performance computational techniques. The primary subject matter addresses specifically the use of satellite gradiometer and GPS observations to form and invert the normal matrix associated with a large degree and order geopotential solution. Memory resident and out-of-core parallel linear algebra techniques along with data parallel batch algorithms form the foundation of the least squares application structure. A secondary topic includes the adoption of object oriented programming techniques to enhance modularity and reusability of code. Applications implementing the parallel and object oriented methods successfully calculate the degree variance for a degree and order 110 geopotential solution on 32 processors of the Cray T3E. The memory resident gradiometer application exhibits an overall application performance of 5.4 Gflops, and the out-of-core linear solver exhibits an overall performance of 2.4 Gflops. The combination solution derived from a sun synchronous gradiometer orbit produce average geoid height variances of 17 millimeters.

Fabrication and electro-optic characteristics of polymer-stabilized V-mode FLCD and intrinsic H-V-mode FLCD: their application to AM LCDs

NASA Astrophysics Data System (ADS)

Kobayashi, Shunsuke; Furuta, Hirokazu; Murakami, Yuji; Xu, Jun; Mochizuki, Akihiro

2003-04-01

Defect free polymer-stabilized (PS-)V-mode FLCDs and intrinsic half (H-)V-mode FLCDs have been fabricated; they exhibit high contrast ratio over 700:1 and high reliability for a temperature cycling test by using specially developed polyimide alignment materials, RN-1411 series, from Nissan Chem. Ind., and also by adopting special alignment technique such as appropriate rubbing technique, photoalignment, and ion beam irradiation techniques and also particularly developed polymer-stabilization technique. These FLCDs are shown to be useful for implementing a field sequential type full color (FS-FC) LCDs due to their fast response with the response time of τ = 100μs ~ 500μs that is 10 to 100 times faster that those of LCDs using NLCs. We have developed several prototype models of FS-FC LCDs having VGA specifications that exhibit good performance for displaying fast moving video rate images with wide color gamut.

Geopotential error analysis from satellite gradiometer and global positioning system observables on parallel architectures

NASA Astrophysics Data System (ADS)

Baker, Gregory Allen

The recovery of a high resolution geopotential from satellite gradiometer observations motivates the examination of high performance computational techniques. The primary subject matter addresses specifically the use of satellite gradiometer and GPS observations to form and invert the normal matrix associated with a large degree and order geopotential solution. Memory resident and out-of-core parallel linear algebra techniques along with data parallel batch algorithms form the foundation of the least squares application structure. A secondary topic includes the adoption of object oriented programming techniques to enhance modularity and reusability of code. Applications implementing the parallel and object oriented methods successfully calculate the degree variance for a degree and order 110 geopotential solution on 32 processors of the Cray T3E. The memory resident gradiometer application exhibits an overall application performance of 5.4 Gflops, and the out-of-core linear solver exhibits an overall performance of 2.4 Gflops. The combination solution derived from a sun synchronous gradiometer orbit produce average geoid height variances of 17 millimeters.

Promoting social behavior with oxytocin in high-functioning autism spectrum disorders

PubMed Central

Andari, Elissar; Duhamel, Jean-René; Zalla, Tiziana; Herbrecht, Evelyn; Leboyer, Marion; Sirigu, Angela

2010-01-01

Social adaptation requires specific cognitive and emotional competences. Individuals with high-functioning autism or with Asperger syndrome cannot understand or engage in social situations despite preserved intellectual abilities. Recently, it has been suggested that oxytocin, a hormone known to promote mother-infant bonds, may be implicated in the social deficit of autism. We investigated the behavioral effects of oxytocin in 13 subjects with autism. In a simulated ball game where participants interacted with fictitious partners, we found that after oxytocin inhalation, patients exhibited stronger interactions with the most socially cooperative partner and reported enhanced feelings of trust and preference. Also, during free viewing of pictures of faces, oxytocin selectively increased patients’ gazing time on the socially informative region of the face, namely the eyes. Thus, under oxytocin, patients respond more strongly to others and exhibit more appropriate social behavior and affect, suggesting a therapeutic potential of oxytocin through its action on a core dimension of autism. PMID:20160081

Oncogenic Role of SND1 in Development and Progression of Hepatocellular Carcinoma

PubMed Central

Jariwala, Nidhi; Rajasekaran, Devaraja; Mendoza, Rachel G.; Shen, Xue-Ning; Siddiq, Ayesha; Akiel, Maaged A.; Robertson, Chadia L.; Subler, Mark A.; Windle, Jolene J.; Fisher, Paul B.; Sanyal, Arun J.; Sarkar, Devanand

2017-01-01

SND1, a subunit of the miRNA regulatory complex RISC, has been implicated as an oncogene in hepatocellular carcinoma (HCC). In this study, we show that hepatocyte-specific SND1 transgenic mice (Alb/SND1 mice) develop spontaneous HCC with partial penetrance and exhibit more highly aggressive HCC induced by chemical carcinogenesis. Livers from Alb/SND1 mice exhibited a relative increase in inflammatory markers and spheroid-generating tumor initiating cells (TIC). Mechanistic investigations defined roles for Akt and NF-κB signaling pathways in promoting TIC formation in Alb/SND1 mice. In human xenograft models of subcutaneous or orthotopic HCC, administration of the selective SND1 inhibitor 3′, 5′-deoxythymidine bisphosphate (pdTp) inhibited tumor formation without effects on body weight or liver function. Our work establishes an oncogenic role for SND1 in promoting TIC formation, and highlights pdTp as a highly selective SND1 inhibitor as a candidate therapeutic lead to treat advanced HCC. PMID:28428278

Low-tar and high-tar cigarettes

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

Holt, P.G.; Chalmer, J.E.; Roberts, L.M.

Mice were exposed for 7 to 8 minutes on weekdays to fresh smoke from high-tar (HT) or low-tar (LT) cigarettes for varying periods of up to 36 weeks. Mice exposed to HT cigarettes exhibited more marked alterations in humoral immune responsiveness, hematological profiles, and pulmonary pathologic findings than those exposed to LT cigarettes. However, cell-mediated immune responsiveness to both bacterial and tumor-specific antigens was depressed similarly in animals exposed to HT or LT cigarettes. Furthermore, the growth rates of subcutaneously established tumors were enhanced similarly in the two groups, with respect to those in control animals.

A Label-Free Aptasensor for Ochratoxin a Detection Based on the Structure Switch of Aptamer.

PubMed

Liu, Feng; Ding, Ailing; Zheng, Jiushang; Chen, Jiucun; Wang, Bin

2018-06-01

A label-free sensing platform is developed based on switching the structure of aptamer for highly sensitive and selective fluorescence detection of ochratoxin A (OTA). OTA induces the structure of aptamer, transforms into G-quadruplex and produces strong fluorescence in the presence of zinc(II)-protoporphyrin IX probe due to the specific bind to G-quadruplex. The simple method exhibits high sensitivity towards OTA with a detection limit of 0.03 nM and excellent selectivity over other mycotoxins. In addition, the successful detection of OTA in real samples represents a promising application in food safety.

Transparent and flexible high-performance supercapacitors based on single-walled carbon nanotube films

NASA Astrophysics Data System (ADS)

Kanninen, Petri; Dang Luong, Nguyen; Hoang Sinh, Le; Anoshkin, Ilya V.; Tsapenko, Alexey; Seppälä, Jukka; Nasibulin, Albert G.; Kallio, Tanja

2016-06-01

Transparent and flexible energy storage devices have garnered great interest due to their suitability for display, sensor and photovoltaic applications. In this paper, we report the application of aerosol synthesized and dry deposited single-walled carbon nanotube (SWCNT) thin films as electrodes for an electrochemical double-layer capacitor (EDLC). SWCNT films exhibit extremely large specific capacitance (178 F g-1 or 552 μF cm-2), high optical transparency (92%) and stability for 10 000 charge/discharge cycles. A transparent and flexible EDLC prototype is constructed with a polyethylene casing and a gel electrolyte.

Alkali Silicate Vehicle Forms Durable, Fireproof Paint

NASA Technical Reports Server (NTRS)

Schutt, John B.; Seindenberg, Benjamin

1964-01-01

The problem: To develop a paint for use on satellites or space vehicles that exhibits high resistance to cracking, peeling, or flaking when subjected to a wide range of temperatures. Organic coatings will partially meet the required specifications but have the inherent disadvantage of combustibility. Alkali-silicate binders, used in some industrial coatings and adhesives, show evidence of forming a fireproof paint, but the problem of high surface-tension, a characteristic of alkali silicates, has not been resolved. The solution: Use of a suitable non-ionic wetting agent combined with a paint incorporating alkali silicate as the binder.

Co(OH)2/RGO/NiO sandwich-structured nanotube arrays with special surface and synergistic effects as high-performance positive electrodes for asymmetric supercapacitors.

PubMed

Xu, Han; Zhang, Chi; Zhou, Wen; Li, Gao-Ren

2015-10-28

High power density, high energy density and excellent cycling stability are the main requirements for high-performance supercapacitors (SCs) that will be widely used for portable consumer electronics and hybrid electric vehicles. Here we investigate novel types of hybrid Co(OH)2/reduced graphene oxide (RGO)/NiO sandwich-structured nanotube arrays (SNTAs) as positive electrodes for asymmetric supercapacitors (ASCs). The synthesized Co(OH)2/RGO/NiO SNTAs exhibit a significantly improved specific capacity (∼1470 F g(-1) at 5 mV s(-1)) and excellent cycling stability with ∼98% Csp retention after 10 000 cycles because of the fast transport and short diffusion paths for electroactive species, the high utilization rate of electrode materials, and special synergistic effects among Co(OH)2, RGO, and NiO. The high-performance ASCs are assembled using Co(OH)2/RGO/NiO SNTAs as positive electrodes and active carbon (AC) as negative electrodes, and they exhibit a high energy density (115 Wh kg(-1)), a high power density (27.5 kW kg(-1)) and an excellent cycling stability (less 5% Csp loss after 10 000 cycles). This study shows an important breakthrough in the design and fabrication of multi-walled hybrid nanotube arrays as positive electrodes for ASCs.

Category-Specific Naming and Recognition Deficits in Temporal Lobe Epilepsy Surgical Patients

PubMed Central

Drane, Daniel L.; Ojemann, George A.; Aylward, Elizabeth; Ojemann, Jeffrey G.; Johnson, L. Clark; Silbergeld, Daniel L.; Miller, John W.; Tranel, Daniel

2008-01-01

Objective Based upon Damasio's “Convergence Zone” model of semantic memory, we predicted that epilepsy surgical patients with anterior temporal lobe (TL) seizure onset would exhibit a pattern of category-specific naming and recognition deficits not observed in patients with seizures arising elsewhere. Methods We assessed epilepsy patients with unilateral seizure onset of anterior TL or other origin (n = 22), pre- or postoperatively, using a set of category-specific items and a conventional measure of visual naming (Boston Naming Test: BNT). Results Category-specific naming deficits were exhibited by patients with dominant anterior TL seizure onset/resection for famous faces and animals, while category-specific recognition deficits for these same categories were exhibited by patients with nondominant anterior TL onset/resection. Patients with other seizure onset did not exhibit category-specific deficits. Naming and recognition deficits were frequently not detected by the BNT, which samples only a limited range of stimuli. Interpretation Consistent with the “convergence zone” framework, results suggest that the nondominant anterior TL plays a major role in binding sensory information into conceptual percepts for certain stimuli, while dominant TL regions function to provide a link to verbal labels for these percepts. Although observed category-specific deficits were striking, they were often missed by the BNT, suggesting that they are more prevalent than recognized in both pre- and postsurgical epilepsy patients. Systematic investigation of these deficits could lead to more refined models of semantic memory, aid in the localization of seizures, and contribute to modifications in surgical technique and patient selection in epilepsy surgery to improve neurocognitive outcome. PMID:18206185

Genomics of parallel adaptation at two timescales in Drosophila

PubMed Central

Begun, David J.

2017-01-01

Two interesting unanswered questions are the extent to which both the broad patterns and genetic details of adaptive divergence are repeatable across species, and the timescales over which parallel adaptation may be observed. Drosophila melanogaster is a key model system for population and evolutionary genomics. Findings from genetics and genomics suggest that recent adaptation to latitudinal environmental variation (on the timescale of hundreds or thousands of years) associated with Out-of-Africa colonization plays an important role in maintaining biological variation in the species. Additionally, studies of interspecific differences between D. melanogaster and its sister species D. simulans have revealed that a substantial proportion of proteins and amino acid residues exhibit adaptive divergence on a roughly few million years long timescale. Here we use population genomic approaches to attack the problem of parallelism between D. melanogaster and a highly diverged conger, D. hydei, on two timescales. D. hydei, a member of the repleta group of Drosophila, is similar to D. melanogaster, in that it too appears to be a recently cosmopolitan species and recent colonizer of high latitude environments. We observed parallelism both for genes exhibiting latitudinal allele frequency differentiation within species and for genes exhibiting recurrent adaptive protein divergence between species. Greater parallelism was observed for long-term adaptive protein evolution and this parallelism includes not only the specific genes/proteins that exhibit adaptive evolution, but extends even to the magnitudes of the selective effects on interspecific protein differences. Thus, despite the roughly 50 million years of time separating D. melanogaster and D. hydei, and despite their considerably divergent biology, they exhibit substantial parallelism, suggesting the existence of a fundamental predictability of adaptive evolution in the genus. PMID:28968391

Design and synthesis of hierarchical mesoporous WO3-MnO2 composite nanostructures on carbon cloth for high-performance supercapacitors

NASA Astrophysics Data System (ADS)

Shinde, Pragati A.; Lokhande, Vaibhav C.; Patil, Amar M.; Ji, Taeksoo; Lokhande, Chandrakant D.

2017-12-01

To enhance the energy density and power performance of supercapacitors, the rational design and synthesis of active electrode materials with hierarchical mesoporous structure is highly desired. In the present work, fabrication of high-performance hierarchical mesoporous WO3-MnO2 composite nanostructures on carbon cloth substrate via a facile hydrothermal method is reported. By varying the content of MnO2 in the composite, different WO3-MnO2 composite thin films are obtained. The formation of composite is confirmed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses. The Brunauer-Emmett-Teller (BET) analysis reveals maximum specific surface area of 153 m2 g-1. The optimized WO3-MnO2 composite electrode demonstrates remarkable electrochemical performance with high specific capacitance of 657 F g-1 at a scan rate of 5 mV s-1 and superior longterm cycling stability (92% capacity retention over 2000 CV cycles). Furthermore, symmetric flexible solid-state supercapacitor based on WO3-MnO2 electrodes has been fabricated. The device exhibits good electrochemical performance with maximum specific capacitance of 78 F g-1 at a scan rate of 5 mV s-1 and specific energy of 10.8 Wh kg-1 at a specific power of 0.65 kW kg-1. The improved electrochemical performance could be ascribed to the unique combination of multivalence WO3 and MnO2 nanostructures and synergistic effect between them

Fe-Catalyzed Synthesis of Porous Carbons Spheres with High Graphitization Degree for High-Performance Supercapacitors

NASA Astrophysics Data System (ADS)

Zhu, Jun; Shi, Hongwei; Zhuo, Xin; Hu, Yalin

2017-10-01

We have developed a facile and efficient Fe-catalyzed method for fabrication of porous carbons spheres with high graphitization degree (GNPCs) using glucose as carbon precursor at relatively low carbonization temperature. GNPCs not only have relatively large accessible ion surface area to accommodate greater capacity but also high graphitization degree to accelerate ion diffusion. As a typical application, we demonstrate that GNPCs exhibit excellent electrochemical performance for use in supercapacitors, with high specific capacity of 150.6 F g-1 at current density of 1 A g-1 and good rate capability and superior cycling stability over 10,000 cycles, confirming their potential application for energy storage. Moreover, it is believed that this method offers a new strategy for synthesis of porous carbons with high graphitization degree.

A Thin Film Flexible Supercapacitor Based on Oblique Angle Deposited Ni/NiO Nanowire Arrays.

PubMed

Ma, Jing; Liu, Wen; Zhang, Shuyuan; Ma, Zhe; Song, Peishuai; Yang, Fuhua; Wang, Xiaodong

2018-06-11

With high power density, fast charging-discharging speed, and a long cycling life, supercapacitors are a kind of highly developed novel energy-storage device that has shown a growing performance and various unconventional shapes such as flexible, linear-type, stretchable, self-healing, etc. Here, we proposed a rational design of thin film, flexible micro-supercapacitors with in-plane interdigital electrodes, where the electrodes were fabricated using the oblique angle deposition technique to grow oblique Ni/NiO nanowire arrays directly on polyimide film. The obtained electrodes have a high specific surface area and good adhesion to the substrate compared with other in-plane micro-supercapacitors. Meanwhile, the as-fabricated micro-supercapacitors have good flexibility and satisfactory energy-storage performance, exhibiting a high specific capacity of 37.1 F/cm³, a high energy density of 5.14 mWh/cm³, a power density of up to 0.5 W/cm³, and good stability during charge-discharge cycles and repeated bending-recovery cycles, respectively. Our micro-supercapacitors can be used as ingenious energy storage devices for future portable and wearable electronic applications.

Direct Heteroepitaxial Growth of ZnO over GaN Crystal in Aqueous Solution

NASA Astrophysics Data System (ADS)

Hamada, Takahiro; Ito, Akihiro; Nagao, Nobuaki; Suzuki, Nobuyasu; Fujii, Eiji; Tsujimura, Ayumu

2013-04-01

We report on the structural and electrical properties of ZnO films grown on surface-treated GaN/Al2O3 substrates by chemical bath deposition. X-ray diffraction analysis indicated that the ZnO films had a single-crystalline wurtzite structure with c-axis orientation. The ZnO film exhibited n-type conduction with a carrier concentration of 6.9 ×1018 cm-3, an electron mobility of 41 cm2/(V.s), and a resistivity of 2.2 ×10-2 Ω.cm. A low specific contact resistivity of 4.3 ×10-3 Ω.cm2 was obtained at the ZnO/n-GaN interface. Additionally, the ZnO film exhibited high transparency in the visible and infrared region.

Heterogeneity of Depressive Symptom Trajectories through Adolescence: Predicting Outcomes in Young Adulthood.

PubMed

Chaiton, Michael; Contreras, Gisèle; Brunet, Jennifer; Sabiston, Catherine M; O'Loughlin, Erin; Low, Nancy C P; Karp, Igor; Barnett, Tracie A; O'Loughlin, Jennifer

2013-05-01

This study describes developmental trajectories of depressive symptoms in adolescents and examines the association between trajectory group and mental health outcomes in young adulthood. Depressive symptoms were self-reported every three months from grade seven through grade 11 by 1293 adolescents in the Nicotine Dependence in Teens (NDIT) study and followed in young adulthood (average age 20.4, SD=0.7, n=865). Semi-parametric growth modeling was used to identify sex-specific trajectories of depressive symptoms. THREE DISTINCT TRAJECTORY GROUPS WERE IDENTIFIED: 50% of boys and 29% of girls exhibited low, decreasing levels of depressive symptoms; 14% of boys and 28% of girls exhibited high and increasing levels; and 36% of boys and 43% of girls exhibited moderate levels with linear increase. Trajectory group was a statistically significant independent predictor of depression, stress, and self-rated mental health in young adulthood in boys and girls. Boys, but not girls, in the high trajectory group had a statistically significant increase in the likelihood of seeking psychiatric care. Substantial heterogeneity in changes in depressive symptoms over time was found. Because early depressive symptoms predict mental health problems in young adulthood, monitoring adolescents for depressive symptoms may help identify those most at risk and in need of intervention.

Insights into the sorption properties of cutin and cutan biopolymers.

PubMed

Shechter, Michal; Chefetz, Benny

2008-02-15

Plant cuticles have been reported as highly efficient sorbents for organic compounds. The objective of this study was to elucidate the sorption and desorption behavior of polar and nonpolar organic compounds with the major structural components of the plant cuticle: the biopolymers cutin and cutan. The sorption affinity values of the studied compounds followed the order: phenanthrene > atrazine > chlorotoluron > carbamazepine. A higher sorption affinity of phenanthrene and atrazine to cutin was probably due to the higher level of amorphous paraffinic carbon in this biopolymer. Phenanthrene exhibited reversible sorption behavior and a high ratio of organic-carbon-normalized distribution coefficient (Koc) to carbon-normalized octanol-water partitioning coefficients (Kowc) with both biopolymers. This suggests that both biopolymers provide phenanthrene with a partition medium for hydrophobic interactions with the flexible long alkyl-chain moieties of the biopolymers. The low Koc/Kowc ratios obtained for the polar sorbates suggest that the polar sites in the biopolymers are not accessible for sorption interactions. Atrazine and carbamazepine exhibited sorption-desorption hysteresis with both sorbents, indicating that both sorbates interact with cutin and cutan via both hydrophobic and specific interactions. In general, the sorptive properties of the studied biopolymers were similar, signifying that the active sorption sites are similar even though the biopolymers exhibit different properties.

Preparation of l-phenylalanine-imprinted solid-phase extraction sorbent by Pickering emulsion polymerization and the selective enrichment of l-phenylalanine from human urine.

PubMed

Li, Ji; Hu, Xiaoling; Guan, Ping; Zhang, Xiaoyan; Qian, Liwei; Zhang, Nan; Du, Chunbao; Song, Renyuan

2016-05-01

A novel l-phenylalanine molecularly imprinted solid-phase extraction sorbent was synthesized by the combination of Pickering emulsion polymerization and ion-pair dummy template imprinting. Compared to other polymerization methods, the molecularly imprinted polymers thus prepared exhibit a high specific surface, large pore diameter, and appropriate particle size. The key parameters for solid-phase extraction were optimized, and the result indicated that the molecularly imprinted polymer thus prepared exhibits a good recovery of 98.9% for l-phenylalanine. Under the optimized conditions of the procedure, an analytical method for l-phenylalanine was well established. By comparing the performance of the molecularly imprinted polymer and a commercial reverse-phase silica gel, the obtained molecularly imprinted polymer as an solid-phase extraction sorbent is more suitable, exhibiting high precision (relative standard deviation 3.2%, n = 4) and a low limit of detection (60.0 ± 1.9 nmol·L(-1) ) for the isolation of l-phenylalanine. Based on these results, the combination of the Pickering emulsion polymerization and ion-pair dummy template imprinting is effective for preparing selective solid-phase extraction sorbents for the separation of amino acids and organic acids from complex biological samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enhanced aging properties of HKUST-1 in hydrophobic mixed-matrix membranes for ammonia adsorption† †Electronic supplementary information (ESI) available: Experimental procedures. See DOI: 10.1039/c5sc04368a Click here for additional data file.

PubMed Central

Denny, Jr., Michael S.; Peterson, Gregory W.; Mahle, John J.

2016-01-01

Metal–organic frameworks (MOFs) in their free powder form have exhibited superior capacities for many gases when compared to other materials, due to their tailorable functionality and high surface areas. Specifically, the MOF HKUST-1 binds small Lewis bases, such as ammonia, with its coordinatively unsaturated copper sites. We describe here the use of HKUST-1 in mixed-matrix membranes (MMMs) prepared from polyvinylidene difluoride (PVDF) for the removal of ammonia gas. These MMMs exhibit ammonia capacities similar to their hypothetical capacities based on the weight percent of HKUST-1 in each MMM. HKUST-1 in its powder form is unstable toward humid conditions; however, upon exposure to humid environments for prolonged periods of time, the HKUST-1 MMMs exhibit outstanding structural stability, and maintain their ammonia capacity. Overall, this study has achieved all of the critical and combined elements for real-world applications of MOFs: high MOF loadings, fully accessible MOF surfaces, enhanced MOF stabilization, recyclability, mechanical stability, and processability. This study is a critical step in advancing MOFs to a stable, usable, and enabling technology. PMID:28660045

Specificity of hammerhead ribozyme cleavage.

PubMed Central

Hertel, K J; Herschlag, D; Uhlenbeck, O C

1996-01-01

To be effective in gene inactivation, the hammerhead ribozyme must cleave a complementary RNA target without deleterious effects from cleaving non-target RNAs that contain mismatches and shorter stretches of complementarity. The specificity of hammerhead cleavage was evaluated using HH16, a well-characterized ribozyme designed to cleave a target of 17 residues. Under standard reaction conditions, HH16 is unable to discriminate between its full-length substrate and 3'-truncated substrates, even when six fewer base pairs are formed between HH16 and the substrate. This striking lack of specificity arises because all the substrates bind to the ribozyme with sufficient affinity so that cleavage occurs before their affinity differences are manifested. In contrast, HH16 does exhibit high specificity towards certain 3'-truncated versions of altered substrates that either also contain a single base mismatch or are shortened at the 5' end. In addition, the specificity of HH16 is improved in the presence of p7 nucleocapsid protein from human immunodeficiency virus (HIV)-1, which accelerates the association and dissociation of RNA helices. These results support the view that the hammerhead has an intrinsic ability to discriminate against incorrect bases, but emphasizes that the high specificity is only observed in a certain range of helix lengths. Images PMID:8670879

Two fatty acyl reductases involved in moth pheromone biosynthesis

PubMed Central

Antony, Binu; Ding, Bao-Jian; Moto, Ken’Ichi; Aldosari, Saleh A.; Aldawood, Abdulrahman S.

2016-01-01

Fatty acyl reductases (FARs) constitute an evolutionarily conserved gene family found in all kingdoms of life. Members of the FAR gene family play diverse roles, including seed oil synthesis, insect pheromone biosynthesis, and mammalian wax biosynthesis. In insects, FAR genes dedicated to sex pheromone biosynthesis (pheromone-gland-specific fatty acyl reductase, pgFAR) form a unique clade that exhibits substantial modifications in gene structure and possesses unique specificity and selectivity for fatty acyl substrates. Highly selective and semi-selective ‘single pgFARs’ produce single and multicomponent pheromone signals in bombycid, pyralid, yponomeutid and noctuid moths. An intriguing question is how a ‘single reductase’ can direct the synthesis of several fatty alcohols of various chain lengths and isomeric forms. Here, we report two active pgFARs in the pheromone gland of Spodoptera, namely a semi-selective, C14:acyl-specific pgFAR and a highly selective, C16:acyl-specific pgFAR, and demonstrate that these pgFARs play a pivotal role in the formation of species-specific signals, a finding that is strongly supported by functional gene expression data. The study envisages a new area of research for disclosing evolutionary changes associated with C14- and C16-specific FARs in moth pheromone biosynthesis. PMID:27427355

GPS-PAIL: prediction of lysine acetyltransferase-specific modification sites from protein sequences.

PubMed

Deng, Wankun; Wang, Chenwei; Zhang, Ying; Xu, Yang; Zhang, Shuang; Liu, Zexian; Xue, Yu

2016-12-22

Protein acetylation catalyzed by specific histone acetyltransferases (HATs) is an essential post-translational modification (PTM) and involved in the regulation a broad spectrum of biological processes in eukaryotes. Although several ten thousands of acetylation sites have been experimentally identified, the upstream HATs for most of the sites are unclear. Thus, the identification of HAT-specific acetylation sites is fundamental for understanding the regulatory mechanisms of protein acetylation. In this work, we first collected 702 known HAT-specific acetylation sites of 205 proteins from the literature and public data resources, and a motif-based analysis demonstrated that different types of HATs exhibit similar but considerably distinct sequence preferences for substrate recognition. Using 544 human HAT-specific sites for training, we constructed a highly useful tool of GPS-PAIL for the prediction of HAT-specific sites for up to seven HATs, including CREBBP, EP300, HAT1, KAT2A, KAT2B, KAT5 and KAT8. The prediction accuracy of GPS-PAIL was critically evaluated, with a satisfying performance. Using GPS-PAIL, we also performed a large-scale prediction of potential HATs for known acetylation sites identified from high-throughput experiments in nine eukaryotes. Both online service and local packages were implemented, and GPS-PAIL is freely available at: http://pail.biocuckoo.org.