bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrothermal Synthesis and Characterization of Europium-doped Barium Titanate Nanocrystallites
Authors: García-Hernández Margarita , Chadeyron Geneviève , Boyer Damien , García-Murillo Antonieta , Carrillo-Romo Felipe , Mahiou Rachid
Published: October 2014

Barium titanate nanocrystallites were synthesized by a hydrothermal technique from barium chloride and tetrabutyl titanate. Single-crystalline cubic perovskite BaTiO3 consisting of spherical particles with diameters ranging from 10 to 30 nm was easily achieved by this route. In order to study the influence of the synthesis process on the morphology and the optical properties, barium titanate was also prepared by a solid-state reaction. In this case, only the tetragonal phase which crystallizes above 900° was observed. High-temperature X-ray diffraction measurements were performed to investigate the crystallization temperatures as well as the particle sizes via the Scherrer formula. The lattice vibrations were evidenced by infrared spectroscopy. Eu3+ was used as a structural probe, and the luminescence properties recorded from BaTiO3:Eu3+and elaborated by a solid-state reaction and hydrothermal process were compared. The reddish emission of the europium is increased by the nanometric particles.
Single-step Preparation of Nano-homogeneous NiO/YSZ Composite Anode for Solid Oxide Fuel Cells
Authors: Song Jung-Hoon , Park Mi Young , Park Hye Won , Lim Hyung-Tae
Published: October 2014

Homogeneous co-precipitation and hydrothermal treatment were used to prepare nano- and highly dispersed NiO/YSZ (yttria-stabilized zirconia) composite powders. Composite powders of size less than 100 nm were successfully prepared. This process did not require separate sintering of the YSZ and NiO to be used as the raw materials for solid oxide fuel cells. The performance of a cell fabricated using the new powders (max. power density ∼0.87 W/cm2) was higher than that of a cell fabricated using conventional powders (max. power density ∼0.73 W/cm2). Co-precipitation and hydrothermal treatment proved to be very effective processes for reducing cell production costs as well as improving cell performance.
Surface Texturing of TiO2 Film by Mist Deposition of TiO2 Nanoparticles
Authors: Qin Gang , Watanabe Akira
Published: October 2014

Unique and various microstructures of titanium oxide (TiO2) film including macroporous structure, chromatic veins and rings, have been easily fabricated by mist deposition method on silicon substrate with mild preparation conditions. Rutile phase TiO2 nanoparticles were directly used as starting material to prepare film and led to a simple preparation process. It was found that several different microstructures existed in the sample and changed with the varied positions from the center to the edge of the film when the concentration of the TiO2 suspension is 0.06 mol/l, the deposition time is 30 min, the flow rate is 1 l/min and the temperature is 150°C. The surface texturing shows apparent distinction as the concentration of the TiO2 suspension decreased to 0.03 mol/l and 0.01 mol/l.
Giant Magneto-impedance Effect in Composite Wires with Different Core Layer
Authors: Wang R. L. , Li X. , Kong X. H. , Guo Y. X. , Ruan J. Z. , Zhao Z. J.
Published: October 2014

Composite structure materials were potential sensing elements for magnetic sensors due to Giant magnetoimpedance (GMI) effect. Two kinds of composite wires with different magnetic/non-magnetic structures were fabricated by using electroless deposition methods and the magnetoimpedance properties were investigated. The maximum GMI ratio of 114% was acquired at 60 MHz in the composite wires with a ferromagnetic core, whereas, 116% of maximum GMI ratio was found in the composite wires with a conductive core at low frequency of 600 kHz. These results exhibit that the GMI ratio reaches the maximum when magnetoresistance ratio ΔR/R and magnetoinductance ratio ΔX/X make the comparative contributions to the total magnetoimpedance (MI). The obvious GMI effect obtained in the composite wires with conductive core frequency may provide a candidate for applications in magnetic sensors, especially at low frequencies.
The Effect of Fabrication Conditions for GDC Buffer Layer on Electrochemical Performance of Solid Oxide Fuel Cells
Authors: Song Jung-Hoon , Jung Myung Geun , Park Hye Won , Lim Hyung-Tae
Published: October 2014

A Gd-doped ceria (GDC) buffer layer is required between a conventional yttria-stabilized zirconia (YSZ) electrolyte and a La-Sr-Co-Fe-O3 (LSCF) cathode to prevent their chemical reaction. In this study, the effect of varying the conditions for fabricating the GDC buffer layer, such as sintering temperature and amount of sintering aid, on the solid oxide fuel cell (SOFC) performance was investigated. A finer GDC powder (i.e., ultra-high surface area), a higher sintering temperature (∼1290°C), and a larger amount of sintering aid (∼12%) resulted in improved densification of the buffer layer; however, the electrochemical performance of an anode-supported cell containing this GDC buffer layer was poor. These conflicting results are attributed to the formation of (Zr, Ce)O2 and/or excess cobalt grain boundaries (GBs) at higher sintering temperatures with a large amount of sintering aid (i.e., cobalt oxide). A cell comprising of a cobalt-free GDC buffer layer, which was fabricated using a low-temperature process, had lower cell resistance and higher stability. The results indicate that electrochemical performance and stability of SOFCs strongly depend on fabrication conditions for the GDC buffer layer.
Enhanced Photocatalytic Activity of ZnO/CuO Nanocomposites Synthesized by Hydrothermal Method
Authors: Chang Tongqin , Li Zijiong , Yun Gaoqian , Jia Yong , Yang Hongjun
Published: October 2014

In this paper, we have demonstrated a facile and low-cost synthesis of the ZnO/CuO nanocomposites by two-step hydrothermal methods. The photocatalytic properties of the as-synthesized ZnO/CuO nanocomposites have been evaluated by the photodegradation of methylene blue (MB) and methyleneorange (MO) under UV irradiation. Experimental results show that MB and MO can be degraded completely within 15 and 25 min by the ZnO/CuO nanocomposites and its photodegradation rate is 6 times faster than that of pure ZnO. This enhanced photocatalytic activity can be ascribed to the low recombination probability of photo-induced carriers due to the efficient charge transfer in the nanocomposites. The as-synthesized ZnO/CuO nanocomposite may be a promising candidate for dye photodegradation of wastewaters.
Superplastic Behavior of Alumina Composites Mediated by Carbon Nanotubes
Authors: Zhou Xiaobing , Li Lei , Shen Lu , Zhou Jie , Zhang Junwei , Mukherjee Amiya K. , Xiang Changshu , Tang Huiping , Huang Qing
Published: October 2014

The high temperature creep behavior of carbon nanotube (CNT)/alumina was mediated by the surface chemical functionalization used for synthesis of composite powders. Non-covalent functionalized carbon nanotubes make composites ductile, but covalent approach leads composites that are creep-resistant. Oxygen vacancy mechanism is proposed to account for this mediation effect in this communication.
Fabrication of Large-area 3-D Ordered Silver-coated Colloidal Crystals and Macroporous Silver Films Using Polystyrene Templates
Authors: Zhu Wen , Wu Yuanyuan , Wang Chengyin , Zhang Ming , Dong Guanxiu
Published: October 2014

The highly ordered silver-coated colloidal crystals arrays and macroporous silver films were derived through an electrostatics-induced adsorption effect using polystyrene (PS) as templates. Carboxyl-modified PS microspheres were prepared by emulsifier-free emulsion polymerization using methacrylic acid (MAA) as the functional monomer. PS microspheres were self-assembled into close packing colloidal crystals of facecentered cubic arrays to the substrate with vertical deposition method. These colloidal crystals were modified using dopamine (DA) to form poly-dopamine (PDA) during its oxidative polymerization. Through electrostatic interaction, the silver nanoparticles were deposited and adsorbed onto the surfaces of colloidal crystals templates by exposing [Ag(NH3)2]+ solution to infrared irradiation. Removal of the polymeric template by etching with methylbenzene solvent resulted in 3D ordered macroporous silver films. The structural and properties of the ordered silver-coated arrays and macroporous silver films were characterized by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), UV-vis spectroscopy and surface-enhanced Raman spectroscopy (SERS). The results indicate that the prepared silver-coated arrays and macroporous silver films possess the features of ordered multilayer arrangement, uniformity and repeatability as well as an ideal SERS effect.
Improving the Electrical Contact Property of Single-Walled Carbon Nanotube Arrays by Electrodeposition
Authors: Zhang Min
Published: October 2014

A parallel method for the fabrication of metal contacts on single-walled carbon nanotube (SWNT) arrays was presented and the electrical contact property was evaluated by a SWNT-field effect transistor structure. Copper and gold contacts were fabricated on both semiconducting SWNTs and metallic SWNTs by using a maskless electrodeposition process. The SWNT array remained a p-type semiconductor after the electrodeposition. The contact resistance between SWNT array and microelectrodes was reduced more than 50% by the established copper contacts. The source-drain current of the carbon nanotube field-effect transistor (CNT-FET) structure can be further increased from 7.9 μA to 9.2 μA when the copper contacts were replaced by gold ones, which is probably due to the better contact property to SWNT of gold contacts with fine grain size.
Controllable Synthesis of Fluorescent Carbon Dots and Their Detection Application as Nanoprobes
Authors: Yang Zhi , Li Zhaohui , Xu Minghan , Ma Yujie , Zhang Jing , Su Yanjie , Gao Feng , Wei Hao , Zhang Liying
Published: October 2014

Carbon dots (CDs), as a new member of carbon nanomaterial family, have aroused great interest since their discovery in 2004. Because of their outstanding water solubility, high sensitivity and selectivity to target analytes, low toxicity, favorable biocompatibility, and excellent photostability, researchers from diverse disciplines have come together to further develop the fundamental properties of CDs. Many methods for the production of CDs have been reported, therein, hydrothermal and solvothermal technology needs simple equipments, and microwave synthesis needs less reaction time, hence these methods become current common synthesis methods, in which many precursors have been applied to produce CDs. Due to their excellent fluorescence, CDs have made impressive strides in sensitivity and selectivity to a diverse array of salt ions, organic/biological molecules and target gases. The development of CDs as nanoprobes is still in its infancy, but continued progress may lead to their integration into environmental and biological applications. Hydrothermal, solvothermal, and microwave synthesis of fluorescent carbon dots and their detection applications as nanoprobes in salt ions, organic/biological molecules, and target gases will be reviewed.
Fabrication and Evaluation of Low-cost Cu2ZnSn(S,Se)4 Counter Electrodes for Dye-sensitized Solar Cells
Authors: Shen Jie , Zhang Dingwen , Li Junjie , Li Xiaodong , Sun Zhuo , Huang Sumei
Published: October 2014

We explore a simple and eco-friendly approach for preparing CZTS powders and a screen-printing process for Cu2ZnSn(S,Se)4 (CZTSSe) counter electrodes (CEs) in dye-sensitized solar cells (DSCs). Cu2ZnSnS4 (CZTS) nanoparticles have been synthesized via a hydrazine-free solvothermal approach without the assistance of organic ligands. CZTS has been prepared by directly drop-casting the CZTS ink on the cleaned FTO glass, while CZTSSe CEs have been fabricated by screen-printing CZTS pastes, followed by post selenization using Se vapor obtained from elemental Se pellets. The crystal structure, composition and morphology of the as-deposited CZTS nanoparticles and CZTSSe electrodes are characterized by X-ray diffractometer, energy dispersive spectrometer, field emission scanning electron microscopy and transmission electron microscopy. The electrochemical properties of CZTS, CZTSSe and Pt CE based DSCs are examined and analyzed by electrochemical impedance spectroscopy. The prepared CZTS and CZTSSe CEs exhibit a cellular structure with high porosity. DSCs fabricated with CZTSSe CEs achieve a power conversion efficiency of 5.75% under AM 1.5 G illumination with an intensity of 100 mW/cm2, which is higher than that (3.22%) of the cell using the CZTS CE. The results demonstrate that the CZTSSe CE possesses good electrocatalytic activity for the reduction of charge carriers in electrolyte. The comprehensive CZTSSe CE process is cheap and scalable. It can make large-scale electro-catalytic film fabrication cost competitive for both energy harvesting and storage applications.
Self-assembly Polyrotaxanes Nanoparticles as Carriers for Anticancer Drug Methotrexate Delivery
Authors: Zhang Longgui , Su Ting , He Bin , Gu Zhongwei
Published: October 2014

α-Cyclodextrin/poly(ethylene glycol) (α-CD/PEG) polyrotaxane nanoparticles were prepared via a self-assembly method. Anticancer drug methotrexate (MTX) was loaded in the nanoparticles. The interaction between MTX and polyrotaxane was investigated. The formation, morphology, drug release and in vitro anticancer activity of the MTX loaded polyrotaxane nanoparticles were studied. The results show that the MTX could be efficiently absorbed on the nanoparticles, and hydrogen bonds were formed between MTX and α-CDs. The typical channel-type stacking assembly style of polyrotaxane nanoparticles was changed after MTX was loaded. The mean diameter of drug loaded polyrotaxane nanoparticles were around 200 nm and the drug loading content was as high as about 20%. Drug release profiles show that most of the loaded MTX was released within 8 hours and the cumulated release rate was as high as 98%. The blank polyrotaxane nanoparticles were nontoxicity to cells. The in vitro anticancer activity of the MTX loaded polyrotaxane nanoparticles was higher than that of free MTX.
RhB Adsorption Performance of Magnetic Adsorbent Fe3O4/RGO Composite and Its Regeneration through A Fenton-like Reaction
Authors: Qin Yalin , Long Mingce , Tan Beihui , Zhou Baoxue
Published: October 2014

Adsorption is one of the most effective technologies in the treatment of colored matter containing wastewater. Graphene related composites display potential to be an effective adsorbent. However, the adsorption mechanism and their regeneration approach are still demanding more efforts. An effective magnetically separable absorbent, Fe3O4 and reduced graphene oxide (RGO) composite has been prepared by an in situ coprecipitation and reduction method. According to the characterizations of TEM, XRD, XPS, Raman spectra and BET analyses, Fe3O4 nanoparticles in sizes of 10–20 nm are well dispersed over the RGO nanosheets, resulting in a highest specific area of 296.2 m2/g. The rhodamine B adsorption mechanism on the composites was investigated by the adsorption kinetics and isotherms. The isotherms are fitting better by Langmuir model, and the adsorption kinetic rates depend much on the chemical components of RGO. Compared to active carbon, the composite shows 3.7 times higher adsorption capacity and thirty times faster adsorption rates. Furthermore, with Fe3O4 nanoparticles as the in situ catalysts, the adsorption performance of composites can be restored by carrying out a Fenton-like reaction, which could be a promising regeneration way for the adsorbents in the organic pollutant removal of wastewater.
Polymeric Hydrogel Nanocapsules: A Thermo and pH Dual-responsive Carrier for Sustained Drug Release
Authors: Nan Jingya , Chen Ying , Li Rutian , Wang Jifu , Liu Meihong , Wang Chunpeng , Chu Fuxiang
Published: October 2014

Hydrogel capsules show attractive prospects in drug delivery recently because of high drug loading and sustained release behavior. In this study we reported a simple and convenient route to fabricate poly (acrylic acid)-poly (N-isopropylacrylamide) (PAA-PNIPAm) hydrogel capsules by using hydroxypropylcellulose-poly (acrylic acid) (HPC-PAA) complexes as the templates. The capsules showed a high drug loading (∼280% to the weight of capsules) for Doxorubicin hydrochloride. The release of drug from the capsules was responsive to the temperature and pH of the surroundings, showing a low-rate but sustained release behavior favorable for low-toxic and long-term therapy. Together with the convenient preparation, high drug loading, dual responsivity as well as the sustained release feature, it is implied that this polymeric hydrogel capsule might be a promising candidate for new drug carriers.
Research Progress in Improving the Rate Performance of LiFePO4 Cathode Materials
Authors: Deng Sixu , Wang Hao , Liu Hao , Liu Jingbing , Yan Hui
Published: October 2014

Olivine lithium iron phosphate (LiFePO4) is considered as a promising cathode material for high power-density lithium ion battery due to its high capacity, long cycle life, environmental friendly, low cost, and safety consideration. The theoretical capacity of LiFePO4 based on one electron reaction is 170 mAh g−1 at the stable voltage plateau of 3.5 V vs. Li/Li+. However, the instinct drawbacks of olivine structure induce a poor rate performance, resulting from the low lithium ion diffusion rate and low electronic conductivity. In this review, we summarize the methods for enhancing the rate performance of LiFePO4 cathode materials, including carbon coating, elements doping, preparation of nanosized materials, porous materials and composites, etc. Meanwhile, the advantages and disadvantages of above methods are also discussed.
Magneto-Impedance Effect of Composite Wires Prepared by Chemical Plating under DC Current
Authors: Chen D. L. , Li X. , Pan H. L. , Luan H. Y. , Zhao Z. J.
Published: October 2014

CuBe composite wires of 100 μm in diameter coated with a layer of NiCoP were prepared by a chemical plating method under DC current (CPUDC). The influences of DC current on coating morphology, deposition rate, composition, giant magneto-impedance (GMI) effect and magnetic properties were investigated. It was shown that the circumferential domain structure of coating layer was induced by the DC current going through the wires. A maximum GMI ratio of 870% was obtained in the composite wire prepared under 150 mA and tested at 180 kHz. It is 30 times higher than that of the composite wire plated in the same condition by conventional chemical plating method, indicating that CPUDC is an easy and effective approach to obtain composite wires and its applications will be further extended on magnetic sensors.
Preparation of Palladium Supported on Ferric Oxide Nano-catalysts for Carbon Monoxide Oxidation in Low Temperature
Authors: Wang Fagen , Xu Yan , Zhao Kunfeng , He Dannong
Published: October 2014

Catalytic property of Pd/Fe2O3 catalysts on carbon monoxide (CO) oxidation at low temperature were investigated in this paper. Both the as-prepared and H2-pretreated Pd/Fe2O3 catalysts show catalytic performances on CO oxidation. The CO was completely converted at 333 K for the as-prepared sample, whereas at 313 K for H2-pretreated Pd/Fe2O3-573 catalyst. The catalytic performance of the Pd/Fe2O3 catalyst decreases with increased calcination temperature. This may be due to the increased crystallinity of the support and decreased metal-support interaction. Progressive deactivation of the catalysts during long-time reaction was associated with the formation of carbonates on the catalyst surface that inhibits CO activation or intermediate transformation.
Doping Induced Tailoring in the Morphology, Band-Gap and Ferromagnetic Properties of Biocompatible ZnO Nanowires, Nanorods and Nanoparticles
Authors: Iqbal Javed , Jan Tariq , Ronghai Yu , Naqvi Sajjad Haider , Ahmad Ishaq
Published: October 2014

The modification of nanostructured materials is of great interest due to controllable and unusual inherent properties in such materials. Single phase Fe doped ZnO nanostructures have been fabricated through simple, versatile and quick low temperature solution route with reproducible results. The amount of Fe dopant is found to play a significant role for the growth of crystal dimension. The effect of changes in the morphology can be obviously observed in the structural and micro-structural investigations, which may be due to a driving force induced by dipole-dipole interaction. The band gap of ZnO nanostructures is highly shifted towards the visible range with increase of Fe contents, while ferromagnetic properties have been significantly improved. The prepared nanostructures have been found to be nontoxic to SH-SY5Y Cells. The present study clearly indicates that the Fe doping provides an effective way of tailoring the crystal dimension, optical band-gap and ferromagnetic properties of ZnO nanostructure-materials with nontoxic nature, which make them potential for visible light activated photocatalyst to overcome environmental pollution, fabricate spintronics devices and biosafe drug delivery agent.
Controlling the Cassie-to-Wenzel Transition: an Easy Route towards the Realization of Tridimensional Arrays of Biological Objects
Authors: Ciasca G. , Papi M. , Chiarpotto M. , De Ninno A. , Giovine E. , Campi G. , Gerardino A. , De Spirito M. , Businaro L.
Published: October 2014

In this paper we provide evidence that the Cassie-to-Wenzel transition, despite its detrimental effects on the wetting properties of superhydrophobic surfaces, can be exploited as an effective micro-fabrication strategy to obtain highly ordered arrays of biological objects. To this purpose we fabricated a patterned surface wetted in the Cassie state, where we deposited a droplet containing genomic DNA. We observed that, when the droplet wets the surface in the Cassie state, an array of DNA filaments pinned on the top edges between pillars is formed. Conversely, when the Cassie-to-Wenzel transition occurs, DNA can be pinned at different height between pillars. These results open the way to the realization of tridimensional arrays of biological objects.
Optimization of Pulse Laser Annealing to Increase Sharpness of Implanted-junction Rectifier in Semiconductor Heterostructure
Authors: Pankratov E. L.
Published: October 2014

It has been recently shown that inhomogeneity of a semiconductor heterostructure leads to increasing of sharpness of diffusion-junction and implanted-junction rectifiers, which are formed in the semiconductor heterostructure. It has been also shown that together with increasing of the sharpness, homogeneity of impurity distribution in doped area increases. The both effect could be increased by formation of an inhomogeneous distribution of temperature (for example, by laser annealing). Some conditions on correlation between inhomogeneities of the semiconductor heterostructure and temperature distribution have been considered. Annealing time has been optimized for pulse laser annealing.
Controlled Growth and Cathodoluminescence Property of ZnS nanobelts with Large Aspect Ratio
Authors: Wu Xiang , Lei Ying , Zheng Yufeng , Qu Fengyu
Published: October 2014

ZnS nanobelts with large aspect ratio are successfully synthesized on a large scale through thermally evaporating of ZnS powder with a trace of SnO2 powder using gold coated Si wafer as the substrate at 1100°C. The results indicate that the as-obtained ZnS nanobelts are about 10 nm in thickness and hundreds of micrometers in length, and the aspect ratio reaches more than 104. Substrate dependent experiments are conducted to better study the growth mechanism of the ZnS nanobelts. Subsequently, optical properties of the as-synthesized ZnS nanobelts are also investigated by using a cathodoluminescence (CL) system, which shows the existence of a strong ultraviolet emission at 342 nm and two poor emission peaks at 522 nm and 683 nm at room temperature, respectively.
Identification of Risk Factors for Pancreatic Exocrine Insufficiency After Pancreaticoduodenectomy Using a 13C‐Labeled Mixed Triglyceride Breath Test
Authors: Hirono Seiko , Murakami Yoshiaki , Tani Masaji , Kawai Manabu , Okada Ken‐ichi , Uemura Kenichiro , Sudo Takeshi , Hashimoto Yasushi , Nakagawa Naoya , Kondo Naru , Yamaue Hiroki
Published: October 2014

Background

There are only a few reports concerning long‐term exocrine function after pancreaticoduodenectomy (PD), although the number of long‐term survivors has increased. We assessed pancreatic exocrine function after PD in 189 patients to identify risk factors for pancreatic exocrine insufficiency.

Methods

We evaluated patients’ exocrine function by using the 13C‐labeled mixed triglyceride breath test, a noninvasive test feasible in outpatient service units. The present study included 99 patients that underwent pancreaticojejunostomy (PJ) at Wakayama Medical University Hospital and 90 patients that underwent pancreaticogastrostomy (PG) at Hiroshima University Hospital, the standard reconstruction techniques during PD at the respective hospitals. We also analyzed long‐term morphological changes of remnant pancreas by computed tomography (main pancreatic duct dilation and parenchymal atrophy), nutritional status, and endocrine function.

Results

Independent risk factors for exocrine insufficiency after PD include hard pancreas (P = 0.003, odds ratio; 3.157) and PG reconstruction (P = 0.040, odds ratio; 2.321). Breath test results correlated significantly with post‐operative morphological changes, nutritional status, and endocrine function. Atrophic changes of the remnant pancreas in the PG group were more severe than those in the PJ group. Furthermore, for patients with a soft pancreas, postoperative body weight changes, prognostic nutritional index, serum total protein levels as well as exocrine test were worse in the PG group, compared with the PJ group.

Conclusions

Our results showed that PJ reconstruction might be superior to PG during PD, from the viewpoint of long‐term pancreatic exocrine function, although further prospective studies are needed.
Autoadjustable Sutures and Modified Seldinger Technique Applied to Laparoscopic Jejunostomy
Authors: Pili Diego , Ciotola Franco , Riganti Juan Martín , Badaloni Adolfo , Nieponice Alejandro
Published: October 2014

This is a simple technique to be applied to those patients requiring an alternative feeding method. This technique has been successfully applied to 25 patients suffering from esophageal carcinoma. The procedure involves laparoscopic approach, suture of the selected intestinal loop to the abdominal wall and jejunostomy using Seldinger technique and autoadjustable sutures. No morbidity or mortality was reported.
Prevalence of Cold Sensitivity in Patients with Hand Pathology
Authors: Novak Christine B. , McCabe Steven J.
Published: October 2014

Background

The purpose of this study was to evaluate the prevalence of cold sensitivity in patients with hand- and wrist-related diagnoses.

Methods

We included English-speaking adults who were more than 1 month following hand injury or onset of symptoms. Patients were asked if exposure to cold air or water provoked cold-related symptoms and to rank symptom severity (scale 0–10). Statistical analyses evaluated the relationships between the cold sensitivity and independent variables (age, gender, history of trauma, and time from injury/symptoms).

Results

There were 197 patients (mean age 49± 16 years): 98 trauma and 99 non-trauma cases. Cold-induced symptoms were reported by 34 %, with 10 % reporting severe symptoms. Exposure to cold air is the most common catalyst; mean severity score was 6.7±2.2. Those with traumatic injuries compared to non-trauma diagnoses reported significantly more cold-induced symptoms ( p=.04). Using backward linear regression, the significant predictors of cold symptom severity were trauma ( p=.004) and time since onset ( p=.003). Including only the trauma patients in the regression model, the significant predictor was time since injury ( p=.005).

Conclusions

Cold-induced symptoms are reported by more than 30 % of hand-related diagnoses, and exposure to cold air was the most commonly reported trigger. The significant predictors of cold-induced symptoms are traumatic injuries and longer time from injury. This study provides evidence of the common problem of cold sensitivity in patients with hand pathology. Level of Evidence: Prognostic Level II
Improved Chemical Synthesis, X‐Ray Crystallographic Analysis, and NMR Characterization of (22R)‐/(22S)‐Hydroxy Epimers of Bile Acids
Authors: Omura Kaoru , Ohsaki Ayumi , Zhou Biao , Kushida Manaka , Mitsuma Takashi , Kobayashi Akiko , Hagey Lee R. , Hofmann Alan F. , Iida Takashi
Published: October 2014

We report an improved synthesis of the (22R)‐ and (22S)‐epimers of 3α,7α,12α,22‐tetrahydroxy‐5β‐cholan‐24‐oic acid and 3α,7α,22‐trihydroxy‐5β‐cholan‐24‐oic acid from cholic acid (CA) and chenodeoxycholic acid (CDCA), respectively. The principal reactions involved were as follows: (1) oxidative decarboxylation of the bile acid peracetates with lead tetraacetate, and (2) subsequent Reformatsky reaction of the 23,24‐dinor‐22‐aldehydes with ethyl bromoacetate in the presence of activated Zn as a catalyst with the reaction temperature maintained precisely at 75 °C. The absolute configuration of the chiral center at C‐22 of each epimer was established by single‐crystal X‐ray diffraction data using its ethyl ester‐peracetate derivative. The 1H‐ and 13C‐NMR spectra that permit the (22R)‐ and (22S)‐epimers to be distinguished are reported as well as the specific 1H shift effects induced by C5D5N. Bile acids having hydroxyl groups at C‐22 are present in a variety of animal biles, previously have been difficult to identify, and are known to have distinctive physicochemical and biological properties.
Joining of Individual Silver Nanowires via Electrical Current
Authors: Vafaei Arash , Hu Anming , Goldthorpe Irene A.
Published: October 2014

A procedure for joining polyol-synthesized silver nanowires in air using current-induced Joule heat welding is reported. Using a common probe station and photolithographically patterned gold electrodes, the welding process is completed using a common semiconductor analyzer. A unique two-step procedure eliminates the dielectric barrier at the point of contact without damaging the nanowires away from the junction. This procedure is designed for metal–metal contacts where a strong dielectric intermediate layer might exist, which can occur with metals prone to oxidation or corrosion in air, or as a result of the electrode deposition process. Ohmic connections are also established in cases where there is an initial gap between two nanowires.
Composites of Graphene and LiFePO4 as Cathode Materials for Lithium-Ion Battery: A Mini-review
Authors: Wu Haixia , Liu Qinjiao , Guo Shouwu
Published: October 2014

This mini-review highlights selectively the recent research progress in the composites of LiFePO4 and graphene. In particularly, the different fabrication protocols, and the electrochemical performance of the composites are summarized in detail. The structural and morphology characters of graphene sheets that may affect the property of the composites are discussed briefly. The possible ongoing researches in area are speculated upon.
Amplified Detection of Iron Ion Based on Plasmon Enhanced Fluorescence and Subsequently Fluorescence Quenching
Authors: Zhou Lin , Zhang Han , Luan Yanping , Cheng Si , Fan Li-Juan
Published: October 2014

A facile and rapid approach for detecting low concentration of iron ion (Fe3+) with improved sensitivity was developed on the basis of plasmon enhanced fluorescence and subsequently amplified fluorescence quenching. Au1Ag4@SiO2 nanoparticles were synthesized and dispersed into fluorescein isothiocyanate (FITC) solution. The fluorescence of the FITC solution was improved due to plasmon enhanced fluorescence. However, efficient fluorescence quenching of the FITC/Au1Ag4@SiO2 solution was subsequently achieved when Fe3+, with a concentration ranging from 17 nM to 3.4 μM, was added into the FITC/Au1Ag4@SiO2 solution, whereas almost no fluorescence quenching was observed for pure FITC solution under the same condition. FITC/Au1Ag4@SiO2 solution shows a better sensitivity for detecting low concentration of Fe3+ compared to pure FITC solution. The quantized limit of detection toward Fe3+ was improved from 4.6 μM for pure FITC solution to 20 nM for FITC/Au1Ag4@SiO2 solution.
Spin-dependent Transport Properties of CrO2 Micro Rod
Authors: Wang Zhen , Xi Li , Yang Yikai , Li Yue , Han Xuemeng , Zuo Yalu , Wang Jianbo
Published: October 2014

The CrO2 micro rod powder was synthesized by decomposing the CrO3 flakes at a specific temperature to yield precursor and annealing such a precursor in a sealed glass tube. The magneto-transport properties have been measured by a direct current four-probe method using a Cu/CrO2 rods/colloidal silver liquid electrode sandwich device. The largest magnetoresistance (MR) around ~72 % was observed at 77 K with applied current of 0.05 μA. The non-linear I–V curve indicates a tunneling type transport properties and the tunneling barrier height is around 2.2 ± 0.04 eV at 77 K, which is obtained with fitting the non-linear I–V curves using Simmons’ equation. A mixing of Cr oxides on the surface of CrO2 rod observed by X-ray photoemission spectroscopy provides a tunneling barrier rather than a single phase of Cr2O3 insulating barrier. The MR shows strong bias voltage dependence and is ascribed to the two-step tunneling process.
Angle-Resolved Plasmonic Properties of Single Gold Nanorod Dimers
Authors: Wu Jian , Lu Xuxing , Zhu Qiannan , Zhao Junwei , Shen Qishun , Zhan Li , Ni Weihai
Published: October 2014

Through wet-chemical assembly methods, gold nanorods were placed close to each other and formed a dimer with a gap distance ~1 nm, and hence degenerated plasmonic dipole modes of individual nanorods coupled together to produce hybridized bonding and antibonding resonance modes. Previous studies using a condenser for illumination result in averaged signals over all excitation angles. By exciting an individual dimer obliquely at different angles, we demonstrate that these two new resonance modes are highly tunable and sensitive to the angle between the excitation polarization and the dimer orientation, which follows cos2φ dependence. Moreover, for dimer structures with various structure angles, the resonance wavelengths as well as the refractive index sensitivities were found independent of the structure angle. Calculated angle-resolved plasmonic properties are in good agreement with the measurements. The assembled nanostructures investigated here are important for fundamental researches as well as potential applications when they are used as building blocks in plasmon-based optical and optoelectronic devices.
Taking a Value Network from Concept to Reality: Canadian Health Leadership Network (A Case Study)
Authors: Tholl Bill
Published: October 2014

This article describes, in a step-by-step way, how the value network concept has been put to work to increase leadership capacity through the Canadian Health Leadership Network (CHLNet). The three phases in evolving the network are described: startup, value creation, and consolidation phases. This is a case study that underscores the fact that networks are best facilitated rather than administered; that trust and reciprocity are the twin pillars for sustaining any network; and that leadership without ownership can be a driving force behind the success of a value network.
The Foundations of Wilderness Medicine: Some Historical Features
Authors: Rodway George W.
Published: October 2014

The surgeons of the navies of the early days of western civilization – Greece, Rome, and the Italian city-states – were most likely the first practitioners of recognizable wilderness medicine. The teachings of Hippocrates and Galen ruled over the practice of medicine in Europe for centuries, but the steady evolution of understanding of the nature and causes of disease was starting to provide a useful foundation upon which to build by the turn of the 19th century. By 1800, nonetheless, the gap between medical theory and knowledge and the real ability to provide effective therapy was still enormous. However, the discovery of anesthesia in the 1840s and Joseph Lister's elucidation and application of the principles of asepsis in 1865 were major steps forward in the history of medicine. Many other improvements in civilian medical care relevant to wilderness medicine, though, have come about as a direct result of military medicine having to determine how to best keep people alive and well, often in very trying combat-related circumstances. The advancement of wilderness medicine has been closely connected to military exploration/operations throughout history, and not surprisingly, this remains in many ways as true today as it was a thousand years ago.
Rare Mitochondrial DNA Polymorphisms are Associated with High Altitude Pulmonary Edema (HAPE) Susceptibility in Han Chinese
Authors: Luo Yongjun , Gao Wenxiang , Chen Yu , Liu Fuyu , Gao Yuqi
Published: October 2014

Background.—

The role of genetics in determining an individual's susceptibility to high altitude pulmonary edema (HAPE) is unclear. However a number of genetic polymorphisms have recently been found to be overrepresented in patients with HAPE. Changes at the mitochondrial level may play an important role in the human body's adaptation to hypoxia. Polymorphisms of mitochondrial DNA (mtDNA) have been shown to be responsible for differences in organelle function. Therefore, the frequency of mtDNA 3397A/G and 3552T/A polymorphisms were studied to determine their potential role in HAPE.

Objectives.—

To further study the role of mtDNA 3397A/G and 3552T/A variations of reduced nicotinamide adenosine dinucleotide dehydrogenase 1 in HAPE susceptibility.

Methods.—

The single-nucleotide polymorphisms of mtDNA 3397 and 3552 in patients with HAPE ( n = 132) and their matched control subjects ( n = 233) were studied using polymerase chain reaction sequencing.

Results.—

The frequency of mtDNA 3397G in the HAPE group (2.3%) was significantly higher than that of the control group (0%; P = .021; odds ratio, 2.806; 95% confidence interval, 2.443 to 3.223). The frequency of mtDNA 3552A in the HAPE group (6.8%) also was significantly higher than in the control group (1.7%; P = .012; odds ratio, 4.198; 95% confidence interval, 1.264 to 13.880).

Conclusions.—

In this study, we present the first evidence of differences in mtDNA polymorphism frequencies between HAPE victims and healthy Han Chinese. Genotypes of mtDNA 3397G and 3552A were correlated with HAPE susceptibility. This result could contribute to defining the role of the mitochondrial genome in the pathogenesis of HAPE.
The Role of the Expedition Doctor: Lessons From 100 Years Ago
Authors: Guly Henry R.
Published: October 2014

This paper explores the role of the doctor on the expeditions of the heroic age of Antarctic exploration. The medical role includes medical screening of prospective expedition members, choosing medical equipment so as to maintain a balance between being able to cope with any eventuality and the cost and weight of equipment and drugs, health screening during an expedition, first aid training for field parties without a doctor, and, obviously, treatment of any injury or disease that occurs. If injury or illness occurs, the presence of a doctor is of great psychological benefit to the expedition. Although medical experience is important, it is probably more important that the doctor is a “team member,” playing a full part in the expedition's aims, whether these are scientific, exploration, or reaching some goal. Most of the lessons learned during these expeditions a hundred years ago are just as relevant today.
Fatalities From Venomous and Nonvenomous Animals in the United States (1999–2007)
Authors: Forrester Jared A. , Holstege Christopher P. , Forrester Joseph D.
Published: October 2014

Objective

To review recent (1999–2007) US mortality data from deaths caused by nonvenomous and venomous animals and compare recent data with historic data.

Methods

The CDC WONDER Database was queried to return all animal-related fatalities between 1999 and 2007. Rates for animal-related fatalities were calculated using the estimated 2003 US population. Inclusion criteria included all mortalities that were a consequence of bite, contact, attack, or envenomation (ICD-10 codes W53–W59 and X20–X29).

Results

There were 1802 animal-related fatalities with the majority coming from nonvenomous animals (60.4%). The largest percentage (36.4%) of animal-related fatalities was attributable to “other mammals,” which is largely composed of farm animals. Deaths attributable to Hymenoptera (hornets, wasps, and bees) have increased during the past 60 years in the United States and now account for more than 79 fatalities per year and 28.2% of the total animal-related fatalities from 1999 to 2007. Dog-related fatalities have increased in the United States, accounting for approximately 28 fatalities per year and 13.9% of the total animal-related fatalities.

Conclusions

Prevention measures aimed at minimizing injury from animals should be directed at certain high-risk groups such as farmworkers, agricultural workers, and parents of children with dogs.
Hyponatremia in an 85-Year-Old Hiker: When Depletion Plus Dilution Produces Delirium
Authors: Coler Clark , Hoffman Martin D. , Towle Gary , Hew-Butler Tamara
Published: October 2014

We report a case of critical exercise-associated hyponatremia in an 85-year-old man, an experienced hiker, during an overnight trek through Yosemite National Park. His medical history was significant for mild renal insufficiency, diastolic dysfunction, and pulmonary hypertension. He was taking a thiazide diuretic (hydrochlorothiazide), without a prior history of an electrolyte imbalance. The hiker drank a modest amount of fluid (3 liters) and urinated only once during the 9-hour descent, from a starting elevation of approximately 3000 meters, before the sudden onset of delirium occurred. He was subsequently airlifted to the nearest hospital. Initial blood sodium concentration ([Na+]) was 120 mEq/L, urine [Na+] was 21 mEq/L, plasma osmolality was 266 mOsm/kgH2O, and urine osmolality 364 mOsm/kgH2O. The patient did not respond to infusions of normal saline, but after an intravenous 20 mg bolus of furosemide, a copious diuresis ensued, after which he recovered fully. This case highlights the complexities of fluid and sodium homeostasis during prolonged hiking, as the combination of both environmental factors (extreme temperatures, altitude, and water and sodium availability) and individual factors (hypertension, age) may have all contributed to the development of life-threatening exercise-associated hyponatremia. This case is unique in that neither the water intoxication model nor the sodium depletion model can fully explain the pathophysiologic findings documented in this report.
The Hawkesbury Canoe Classic: Musculoskeletal Injury Surveillance and Risk Factors Associated With Marathon Paddling
Authors: Abraham David , Stepkovitch Nicholas
Published: October 2014

Objective

The aim of this study was to assess the incidence and risk factors for musculoskeletal injury associated with marathon paddling.

Methods

A prospective observational cohort study was conducted during the 2006 Hawkesbury Canoe Classic (HCC), an annual 111-km paddling race in Sydney, Australia. Before the race, a written questionnaire was distributed to competitors to gather information regarding their age, gender, type of craft they were competing in, paddling experience, HCC experience, training distances, and preceding injuries. The paddler's average race speed was also used for analysis. Injuries were recorded throughout the race. Logistic regression analysis was used to identify if any of the variables were associated with injuries observed during the race.

Results

Six hundred and twelve paddlers competed in the race, with 298 respondents participating in the study. Eighty-eight paddlers with a total of 135 injuries presented for medical assessment. More than one third of injuries involved the shoulder (35.6%), followed by the thoracic spine (23%), and lumbar spine (17%). Men were 3.6 times (CI: 1.39 to 9.32, P = .01) more likely to present with an injury compared with the women. A faster average speed (ie, faster finishing time) was correlated with a decrease in injury presentation (odds ratio 0.77, CI: 0.63 to 0.93, P = .01). Modifiable risk factors such as age, type of craft, paddling experience, HCC experience, training distances, and preceding injuries were not shown to increase the chance of injury presentation.

Conclusions

Further data gathered over a series of this race may point to modifiable risk factors that may help reduce the incidence of injury.
The association between obesity and fluid intelligence impairment is mediated by chronic low-grade inflammation
Authors: Spyridaki Eirini C. , Simos Panagiotis , Avgoustinaki Pavlina D. , Dermitzaki Eirini , Venihaki Maria , Bardos Achilles N. , Margioris Andrew N.
Published: October 2014

Published evidence suggests that obesity impairs cognition. Development of chronic low-grade inflammation (CLGI) represents the earliest consequence of obesity. The present study investigated the association between obesity and fluid intelligence impairment and assessed the potential mediating role of CLGI and psychological (depression/anxiety symptoms), lifestyle (exercise) and physiological (metabolic dysfunction indices) factors in this association. Clinically healthy participants (n188), grouped as per BMI, underwent cognitive (General Ability Measure for Adults), psychological (Beck Depression Inventory-II and State-Trait Anxiety Inventory) and activity (Godin leisure-time physical activity) measurements. Biochemical parameters included the following: (a) indices of CLGI (high-sensitivity C-reactive protein, erythrocyte sedimentation rate and fibrinogen); (b) insulin resistance (Homeostasis Model Assessment of Insulin Resistance index); (c) adiposity (plasma adiponectin). An inverse association between elevated BMI and fluid intelligence was observed, with obese participants displaying significantly poorer performance compared with age-matched normal-weight peers. Structural equation modelling results were consistent with a negative impact of obesity on cognition that was mediated by CLGI. The results of the present study support the hypothesis that reduced general cognitive ability is associated with obesity, an adverse effect mainly mediated by obesity-associated activation of innate immunity.