bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies of Interaction between Ergosta‐4,6,8(14),22‐tetraen‐3‐one (Ergone) and Human Serum Albumin by Molecular Spectroscopy and Modeling
Authors: Sun Yang , Zhao Yingyong , Li Guobo , Yang Shengyong , Hu Xiaoyun , Fan Jun 
Published: October 2011

AbstractOur previous experimental results have shown that ergosta‐4,6,8(14),22‐tetraen‐3‐one (ergone) is one of the main bioactive components of Polyporus umbellatus. The efficacy of ergone binding to human serum albumin (HSA) is critical for pharmacokinetic behavior of ergone. The interactions between ergone and HSA under simulative physiological conditions were investigated by the methods of fluorescence spectroscopy, absorption and circular dichroism spectroscopy. Fluorescence data revealed that the fluorescence quenching of HSA by ergone was the result of the formation of the ergone‐HSA complex. According to the modified Stern‐Volmer equation, the binding constants (Ka) between ergone and HSA were determined. The thermodynamic parameters, enthalpy change (ΔH) and entropy change (ΔS) for the reaction were calculated to be 0.989 kJ mol‐1 and 11.214 J mol‐1 K‐1, indicating that the hydrogen bonds and hydrophobic interactions played a dominant role in the binding of ergone to HSA. The conformational investigation showed that the presence of ergone decreased the α‐helical content of HSA and induced the slight unfolding of the polypeptides of protein. Furthermore, displacement experiments using warfarin and ibuprofen indicated that ergone could bind to site I of HSA, which was also in agreement with the results of the molecular modeling.
Synthesis, Characterization and Photophysical Properties of Iridium(III) Bis‐cyclometallated Complexes Containing 1,1‐Dithiolates
Authors: Sie Wu‐Sian , Jian Jing‐Yu , Shiu Kom‐Bei 
Published: October 2011

AbstractA series of neutral Ir(III)‐based heteroleptic complexes with a formula of [Ir(η2‐(C∧N))2(η2‐(S∧S))] ((C∧N)‐ = ppy‐, (S∧S)‐ = Et2NCS2‐ (2a), MeOCS2‐ (2b), EtOCS2‐ (2c), iPrOCS2‐ (2d); (C∧N)‐ = tpy‐, (S∧S) = Et2NCS2‐ (3a), MeOCS2‐ (3b), EtOCS2‐ (3c), iPrOCS2‐ (3d); (C∧N)‐ = epb‐ , (S∧S)‐ = Et2NCS2‐ (4a), MeOCS2‐ (4a), EtOCS2‐ (4a); ppyH = 2‐phenylpyridine; tpyH = 2‐(4′‐tolyl)pyridine; epbH = ethyl 4‐(2′‐pyridyl)benzate) was synthesized and characterized. The crystal structure of complex 2d was also determined. The electron‐releasing substituents on (C∧N)‐ or (S∧S)‐ blueshift λmax values.
Preparation and Electrochemical Behaviour of Silver Pentacyanonitrosylferrate Film Modified Glassy Carbon Electrode and Its Electrocatalytic Oxidation to L‐cysteine
Authors: Liu Suqin , Dai Gaopeng 
Published: October 2011

AbstractA glassy carbon (GC) electrode modified with silver pentacyanonitrosylferrate (AgPCNF) film as a redox mediator was fabricated. Cyclic voltammetry was used to study the redox property of AgPCNF modified electrode. The modified electrode showed a well‐defined redox couple due to [AgIFeIII/II(CN)5NO]1‐/2‐system. The effects of scan rates, supporting electrolytes and solution pHs were studied on the electrochemical behavior of the modified electrode. The feasibility of using the AgPCNF modified electrode to measure L‐cysteine was investigated. It showed an excellent electrocatalytic activity towards the oxidation of L‐cysteine and the anodic currents were proportional to the L‐cysteine concentration in the range of 0.1 μM to 20 μM, the linear regression equation is Ipa(μA) = ‐68.58 ‐ 5.78CL‐cysteine (μM), with a correlation coefficient 0.998 for N = 23. The detection limit was down to 3.5 × 10‐8 M (three times the ratio of signal to noise).
Speciation and Determination of Trace Amount of Inorganic Arsenic in Water, Environmental and Biological Samples
Authors: Shirkhanloo Hamid , Mousavi Hassan Zavvar , Rouhollahi Ahmad 
Published: October 2011

AbstractA new speciation and preconcentration method based on dispersive liquid‐liquid microextraction has been developed for trace amounts of As(III) and As(V) in urine and water samples. At pH 4, As(III) is complexed with ammoniumpyrrolidine dithiocarbamate and extracted into 1‐Hexyl‐3‐methylimidazolium hexafluorophosphate, as an ionic liquid (IL) and As(III) is determined by electrothermal atomic absorption spectrometery (ETAAS). Arsenic(V) in the mixing solution containing As(III) and As(V) was reduced by using KI and ascorbic acid in HCl solution and then the procedure was applied to determination of total arsenic. Arsenic(V) was calculated as the difference between the total arsenic content and As(III) content. The effect of various parameters on the recovery of the arsenic ions has been studied. Under the optimum conditions, the enrichment factor 135 was obtained. The proposed method was successfully applied to the determination of trace amounts of As(III) and As(V) in water and biological samples.
Computational Study of the Substitution Effect on the Mechanism for the Aza‐ and Arsa‐Wittig Reactions
Authors: Liao Hsin‐Yi 
Published: October 2011

AbstractThe aza‐ and arsa‐Wittig reactions HM=PH3 + O=CHX → HM=CHX + O=PH3 (M = N, As; X = H, F, Cl, Me, OMe, NMe2, CMe3) were examined using the density functional theory calculations. All of the structures were completely optimized at the B3LYP/6‐311++G** level of theory. The main finding of this work is that the difference between singlet‐triplet splitting of O=CHX and HM=PH3 play an important role in determining the kinetic and thermodynamic stability of the aza‐ and arsa‐Wittig reactions. When HM=PH3 with more ylidic character is utilized, the reaction has a smaller activation energy and a larger exothermicity.
Physical‐chemical Test Platform for Room Temperature, Far‐infrared Ray Emitting Ceramic Materials (cFIR)
Authors: Leung Ting‐Kai , Huang Pai‐Jung , Chen Yi‐Chien , Lee Chi‐Ming 
Published: October 2011

AbstractCeramic far‐infrared (cFIR) emitting materials are sources of room temperature FIR radiation that allow non‐thermal irradiation of biological tissue. In this study, we explored some interesting physical and chemical effects that have not been reported. We investigated the effects of cFIR irradiation of sorghum wine using gas chromatography with solid‐phase micro‐extraction (GC‐SPME) to demonstrate enhancement on volatility; monitored pH changes resulting from irradiation on acetic acid; and used UV spectroscopy to identify and quantify chemical changes. On the basis of the results, we deduced that cFIR possesses the ability of weakening hydrogen bond and exhibits chemical reduction change. The methods above provide a relatively convenient and cost‐effective test platform to demonstrate the application of cFIR as an effective alternative to biological assay.
Crown Ethers Bearing 18C6 Unit; Sensory Molecules for Fabricating PVC Membrane Lead Ion‐selective Electrodes
Authors: Zamani A. A. , Khorsihdi N. , Mofidi Z. , Yaftian M. R. 
Published: October 2011

AbstractCrown ethers bearing 18C6 unit 18‐crown‐6 (18C6), dicyclohexyl18‐crown‐6 (DC18C6) and dibenzo18‐crown‐6 (DB18C6) have been examined as ion sensing materials for fabricating lead ion‐selective potentiometric sensors. Best performance of the electrode based upon 18C6 ionophore was achieved by using a membrane including 9% ionophore, 30% polyvinyl chloride (PVC), 2% oleic acid and 59% dibutylphthalate (DBP). The optimum composition for the sensors based on DC18C6 and DB18C6 was provided by the compositions: 9% DC18C6, 30% PVC, 1.5% sodium tetraphenyl borate (NaTBP), 59.5% DBP; and 5.9% DB18C6, 29.7% PVC, 2.5% NaTBP and 61.9% DBP, respectively. The linear response range of the electrode based on 18C6 (1 × 10‐6‐1 × 10‐3 M) differs from that presented by the DC18C6‐ and DB18C6‐based electrodes (1 × 10‐5‐1 × 10‐2 M). All the sensors were shown rapid response time (<12 s). The detection limit of the electrodes varies as 5.6 × 10‐7, 6.3 × 10‐6 and 7.1 × 10‐6 M, for 18C6‐, DC18C6‐ and DB18C6‐based electrodes, respectively. The selectivity of the electrodes towards lead ions over some mono‐, di‐ and trivalent metal ions was evaluated. The lifetime of the electrode based on DC18C6 or DB18C6 ionophores was found to be more than three months, while it was shorter for 18C6‐based electrode. The application of the electrodes in aqueous samples was assessed.
Electrochemical Deposition of Gold Nanoparticles on Pencil Graphite by Fast Scan Cyclic Voltammetry
Authors: Etesami Mohammad , Karoonian Fatemeh Salehi , Mohamed Norita 
Published: October 2011

AbstractGold nanoparticles (AuNPs) were electrodeposited on the surface of pencil graphite (PG) by fast scan cyclic voltammetry without using any additives in acidic medium. The effect of deposition time on the size of electrodeposited AuNPs was investigated in sulfuric acid as a supporting electrolyte. The deposition time was varied by varying the scan rate, number of cycles and applied potential range. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X‐ray diffraction (XRD) were used for characterization of PG and electrodeposited AuNPs. The results confirmed that nanosized gold particles (20 ± 8 nm) were deposited on the PG substrate with almost spherical geometry.
Quantitative Evaluation of Trace Elements in Sediments of the Tamsui River via Instrumental Neutron Activation Analysis
Authors: Chang Chih‐Chia , Chen Shiuan‐Chih , Tsai Chin‐Feng , Lin Jye‐Bin , Chang Yih‐Hsin , Chen Chien‐Yi , Pan Lung‐Kwang , Lin Ding‐Bang 
Published: October 2011

AbstractThe present study examined concentrations of trace elements in the sediments collected from 31 locations along the banks of Tamsui River by instrumental neutron activation analysis. The Tamsui River is famous for containing a unique area of naturally preserved mangrove in northern Taiwan. It is also the second longest river among the 3 major rivers in Taiwan. A total of 11 nuclides, including Mg, Al, Ti, Mn, Na, Sc, As, Br, La, Fe and Cs, were identified. The categories and measurements of nuclides detected were interpreted according to the sampling locations or chemical attributes characteristics. A dimensionless index (CI) was introduced to explore the quantitative correlation among the detected nuclides. A smaller CI corresponded to a stronger correlation between a pair of nuclides, such that the correlation between the nuclides can be interpreted through a series of quantified indices. The minimum detectable concentration (MDC) for As‐76 was fluctuated around 0.67 ± 0.09 μg/g due to the variations of background counts in various gamma spectra.
Synthesis and X‐ray characterization of 2,5,6‐trisubstituted imidazo[2,1‐b][1,3,4]thiadiazole derivatives
Authors: Da Yu‐Xia , Zhu Ji‐Hua , Zhang Zhang , Jia Xiao‐Dong , Yang Cai‐Xia , Quan Zheng‐Jun 
Published: October 2011

AbstractA series of 2,5,6‐trisubstituted imidazo[2,1‐b][1,3,4]thiadiazoles via Mannich reaction of imidazo[2,1‐b][1,3,4]thiadiazoles with morpholine and formaldehyde were synthesized. Structures of all the newly synthesized compounds are well supported by spectral data such as IR, NMR, Mass, and Elemental analysis. Compound 3a has been confirmed by X‐ray diffraction studies. J. Heterocyclic Chem., (2012).
Pediatric hospital medicine: A strategic planning roundtable to chart the future
Authors: Rauch Daniel A. , Lye Patricia S. , Carlson Douglas , Daru Jennifer A. , Narang Steve , Srivastava Rajendu , Melzer Sanford , Conway Patrick H. 
Published: October 2011

AbstractGiven the growing field of Pediatric Hospital Medicine (PHM) and the need to define strategic direction, the Society of Hospital Medicine, the American Academy of Pediatrics, and the Academic Pediatric Association sponsored a roundtable to discuss the future of the field. Twenty‐one leaders were invited plus a facilitator utilizing established health care strategic planning methods. A “vision statement” was developed. Specific initiatives in 4 domains (clinical practice, quality of care, research, and workforce) were identified that would advance PHM with a plan to complete each initiative. Review of the current issues demonstrated gaps between the current state of affairs and the full vision of the potential impact of PHM. Clinical initiatives were to develop an educational plan supporting the PHM Core Competencies and a clinical practice monitoring dashboard template. Quality initiatives included an environmental assessment of PHM participation on key committees, societies, and agencies to ensure appropriate PHM representation. Three QI collaboratives are underway. A Research Leadership Task Force was created and the Pediatric Research in Inpatient Settings (PRIS) network was refocused, defining a strategic framework for PRIS, and developing a funding strategy. Workforce initiatives were to develop a descriptive statement that can be used by any PHM physician, a communications tool describing “value added” of PHM; and a tool to assess career satisfaction among PHM physicians. We believe the Roundtable was successful in describing the current state of PHM and laying a course for the near future. Journal of Hospital Medicine 2012. © 2011 Society of Hospital Medicine
UV–VIS detection of amino acids in liquid chromatography: Online post‐column solid‐state derivatization with Cu(II) ions
Authors: Kubíc̆ková Anna , Kubíc̆ek Vojtĕch , Coufal Pavel 
Published: October 2011

AbstractIn this work, we describe the introduction of a post‐column solid‐state reactor in the HPLC system used for the analyses of amino acids. The reactor used was filled with copper(II) oxide. Passage of the analytes through the reactor leads to the formation of Cu(II) complexes. Unlike free amino acids, the Cu‐complexes show significant absorbance in the UV region and accordingly sensitivity of UV–VIS detection is increased by two to three orders of magnitude. As a result of this improvement in sensitivity, we have obtained LOD values in micromolar range and good linearity over the studied concentration range (5.0×10−5 to 2.0×10−3 mol/L). The method exhibits advantages typical of solid‐state reactors, such as negligible loss of efficiency due to the derivatization, simplicity of realization and a long‐term durability. The presented system brings an easy and versatile solution for UV–VIS detection of coordinating compounds, which do not normally absorb well in the UV–VIS region.
Overcoming nasal discomfort—A novel method for office‐based laser surgery
Authors: Verma Sunil P. , Dailey Seth H. 
Published: October 2011

AbstractObjectives:The passage of a flexible channeled laryngoscope for office‐based laser laryngeal surgery can be limited by narrow nasal passages, nasal discomfort, or both. We describe a novel method for delivering the laser fiber transorally with simultaneous laryngeal visualization to avoid these limitations. This technique can be employed with instruments available in most otolaryngologists' offices.Methods:A retrospective chart review was performed and procedural details were recorded.Results:Technical description: A laser fiber was threaded through the shaft of an Abraham cannula. A patient was seated in an otolaryngology examination chair and instructed to hold and stabilize his own tongue. Using his nondominant hand, the surgeon placed a rigid angled telescope into the patient's oral cavity for laryngeal visualization. Using his dominant hand, the surgeon simultaneously introduced the laser fiber threaded through the Abraham cannula into the patients oral cavity and guided it towards the patients larynx. Energy from the PDL, KTP, or CO2 flexible laser fibers was then delivered for management of glottic papillomatosis and leukoplakia. Treatment of glottic lesions was achieved successfully in all cases with titration endpoints identical to the transnasal approach.Conclusions:For patients who cannot tolerate transnasal passage of a flexible channeled laryngoscope during office‐based laser laryngeal surgery, an attractive alternative to surgery under general anesthesia is the transoral technique. This approach does not rely on distal chip endoscopes and can be performed with existing equipment in an office setting.
Pullulan Hydrogels Improve Mesenchymal Stem Cell Delivery into High‐Oxidative‐Stress Wounds
Authors: Wong Victor W. , Rustad Kristine C. , Glotzbach Jason P. , Sorkin Michael , Inayathullah Mohammed , Major Melanie R. , Longaker Michael T. , Rajadas Jayakumar , Gurtner Geoffrey C. 
Published: October 2011

AbstractCell‐based therapies for wound repair are limited by inefficient delivery systems that fail to protect cells from the acute inflammatory environment. Here, a biomimetic hydrogel system is described that is based on the polymer pullulan, a carbohydrate glucan known to exhibit potent antioxidant capabilities. It is shown that pullulan hydrogels are an effective cell delivery system and improve mesenchymal stem cell survival and engraftment in high‐oxidative‐stress environments. The results suggest that glucan hydrogel systems may prove beneficial for progenitor‐cell‐based approaches to skin regeneration.magnified image
Tissue‐Specific Stem Cell Differentiation in an in vitro Airway Model
Authors: Prytherch Zoë , Job Claire , Marshall Hilary , Oreffo Victor , Foster Martyn , BéruBé Kelly 
Published: October 2011

AbstractThe respiratory tract is the primary site of exposure to airborne compounds, with the bronchial epithelium providing one of the first lines of defence. A growing need exists for an accurate in vitro model of the bronchial epithelium. Here, normal human bronchial epithelial (NHBE) cells cultured at an air/liquid interface create a fully differentiated, in‐vivo‐like model of the human bronchial epithelium. Developmental characterisation includes (i) trans‐epithelial electrical resistance, (ii) morphology and (iii) bronchial cell specific stains/markers. It is concluded that the basal/progenitor cells create a pseudo‐stratified, mucociliary NHBE model containing basal, serous, Clara, goblet and ciliated cells, reflective of the normal human bronchial epithelium (days 24–33 ALI culture).magnified image
π‐Conjugated Polymers Consisting of 9,10‐Dihydrophenanthrene Units
Authors: Yamamoto Takakazu , Tokimitsu Ryouichi , Asao Takahiro , Iijima Takayuki , Fukumoto Hiroki , Koizumi Take‐aki , Fukuda Takashi , Ushijima Hirobumi 
Published: October 2011

Abstractπ‐Conjugated polymers consisting of 9,10‐disubstituted 9,10‐dihydrophenenthrene, with the substituents octyl, 2‐ethylhexyl, ‐OSiBu3, etc., units are prepared by organometallic polycondensation. Homopolymers (PH2Ph(9,10‐R)) have a π‐conjugation system similar to that of polymers of 9,9‐dialkylfluorene and show UV‐Vis peaks at ≈380 nm. In addition to the peak at ≈380 nm, some homopolymers give rise to a peak at a longer wavelength, suggesting molecular assembly of the polymers. X‐ray diffraction data support the molecular assembly. The homopolymers show photoluminescence (PL) with PL peaks at ≈430 nm, and PL spectrum of the polymer film is essentially unchanged after heating the polymer film at 150 °C in air. The homopolymers undergo electrochemical p‐doping at about 1.5 V versus Ag+/Ag.
Reversibly Switchable pH‐ and Thermoresponsive Core–Shell Nanogels Based on Poly(NiPAAm)‐graft‐poly(2‐carboxyethyl‐2‐oxazoline)s
Authors: Zschoche Stefan , Rueda Juan Carlos , Binner Marcus , Komber Hartmut , Janke Andreas , Arndt Karl‐Friedrich , Lehmann Stefan , Voit Brigitte 
Published: October 2011

AbstractAmphiphilic graft copolymers with a thermosensitive PNiPAAm backbone and pH‐sensitive hydrophilic poly(2‐carboxyethyl‐2‐oxazoline) graft chains are synthesized. In aqueous solution, stable micelle‐like aggregates are formed by increasing the temperature in the pH range 4.5–5.5. The micelles are crosslinked by electron‐beam irradiation, yielding stable core–shell nanogels of about 100 nm diameter with reversible thermo‐ and pH‐dependent swelling behavior. The temperature sensitivity is provided by a conformational change in the PNiPAAm core, whereas the thickness of the poly(2‐carboxyethyl‐2‐ oxazoline) corona depends on pH. The reversible bisensitivity of core‐crosslinked nanogels is verified by DLS, while AFM measurements demonstrate the predicted core–shell structures of the aggregates.
Quasi‐Solid‐State Dye‐Sensitized Solar Cells Using Nanocomposite Gel Polymer Electrolytes Based on Poly(propylene carbonate)
Authors: Choi Yeon Jeong , Han Yonggyu , Ok Myoung‐Ahn , Kim Dong‐Won 
Published: October 2011

AbstractPoly(propylene carbonate) (PPC) is synthesized from the copolymerization of CO2 and propylene oxide. Novel nanocomposite gel polymer electrolytes (GPEs) are prepared by utilizing PPC, organic solvents containing a redox couple, and aluminum oxide nanoparticles for application in dye‐sensitized solar cells (DSSCs). The quasi‐solid‐state DSSC assembled with optimized nanocomposite GPEs exhibits a relatively high conversion efficiency of 6.16% at 100 mW cm−2 and better stability than DSSC with liquid electrolyte.
Formation of Highly Aligned, Single‐Layered, Hollow Fibrous Assemblies and the Fabrication of Large Pieces of PLLA Membranes
Authors: Yang Jen‐Chang , Lee Sheng‐Yang , Tseng Wen‐Chin , Shu Yao‐Chi , Lu Jen‐Chieh , Shie Han‐Shian , Chen Chien‐Chung 
Published: October 2011

AbstractLarge pieces of paper‐thin PLLA membranes are prepared and characterized as single‐layered hollow fibrous assemblies with an extremely high degree of fiber alignment. The diameter of the electrospun hollow fibers is in the range of some tens of micrometers with a wall thickness of a few micrometers. They are best described as 2D arrays of highly aligned microtubes. The mechanical properties of the membranes are studied. A processing map is constructed using the applied electric field strength and the concentration (viscosity) of the electrospinning dope. The influence of factors such as the field strength and weight and viscosity of the jetted solutions is discussed. The results will help in the future fabrication of highly anisotropic scaffolds for tissue engineering applications.magnified image
Classification of New Melt‐Processable PTFE: Comparison of Emulsion‐ and Suspension‐Polymerized Materials
Authors: Frick Achim , Sich Dorota , Heinrich Gert , Stern Claudia , Schlipf Michael 
Published: October 2011

AbstractA new melt‐processable PTFE material is presented and characterized that provides new and economical solutions in polymer technology while bridging the gap between perfluorinated PTFE and fluorothermoplastic materials such as perfluoroalkoxy resins. Thermal transitions, MW and MWD, and microstructures of the melt‐processable PTFE materials are investigated and compared to standard PTFE, modified PTFE, and PFA materials. The influence of the polymerization type used for the preparation of the melt‐processable PTFE (emulsion and suspension polymerization) on the MWD and the comonomer distribution are discussed.magnified image