bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of Nanopore Electrode Structures as Basis for Amplified Electrochemical Assays
Authors: Neugebauer Sebastian , Müller Ulrich , Lohmüller Theobald , Spatz Joachim P. , Stelzle Martin , Schuhmann Wolfgang 
Published: October 2006

AbstractA nanopore electrode structure was fabricated consisting of ensembles of nanopores with separately addressable electrodes at the pore bottoms and the rims. A metal/insulator/metal layer structure allowed for adjusting the spacing between the bottom and rim electrodes to be in the range of about 200 nm. Pore diameters varied between 200 and 800 nm. The electrochemical properties of this electrode structure and its perspectives for applications in bioelectronics were studied using cyclic voltammetry and chronoamperometry along with high‐resolution scanning electrochemical microscopy (SECM) in constant‐distance mode. It was possible to visualize the electrochemical activity of a single nanometric electrode using high‐resolution SECM in a combination of sample‐generation‐tip‐collection mode and positive feedback mode. The SECM images suggested an influence of the unbiased rim electrode on redox amplification which was used as a basis for evaluating the feasibility of current amplification by means of redox cycling between the bottom and rim electrodes. Amplification factors superior to those obtained with interdigitated array electrodes could be demonstrated.
Nanoarray‐Surfaces by Reconstitution of the Porin MspA into Stabilized Long‐Chain‐Lipid‐Monolayers at a Gold‐Surface
Authors: Wörner Michael , Niebler Sandra , Gogritchiani Eliso , Egner Nicole , Braun André M. , Niederweis Michael , Bossmann Stefan H. 
Published: October 2006

AbstractWe have reconstituted the channel porin MspA from M. smegmatis on a gold electrode into a long‐chain lipid monolayer resembling a biological membrane. The tailored deposition of the self‐assembled monolayer (SAM) on gold was achieved by employing electrochemically initiated generation of thiyl‐radicals from organic thiosulfates (Bunte‐Salts), which then adsorb onto the gold's surface. At surface coverage of the lipids of approximately 80%, MspA reconstituted efficiently from the aqueous buffer into the SAM. The combination of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), reflection electron microscopy (REM) and the formation of copper(0)‐nanoparticles from copper(II)‐ions inside the MspA‐channels proved that MspA forms SAM‐spanning ion channels on gold, keeping the electrode (surface) accessible through the pores.
Straw bed priming enhances the methane yield and speeds up the start‐up of single‐stage, high‐solids anaerobic reactors treating plant biomass
Authors: Svensson L Mattias , Björnsson Lovisa , Mattiasson Bo 
Published: October 2006

AbstractA simple and potentially inexpensive implementation of a high‐solids reactor is a single‐stage, stratified bed reactor, in which the bed is made up of the plant biomass fed into the system. In the present study, the stratified bed was started up for a period of four weeks by either direct feeding of sugar beet leaves at four different feeding rates, or by introducing a straw bed primer which was batch digested without feeding. During weeks five to six both systems were fed with sugar beet leaves at such a rate that the total amount of beet leaves added at the end of week six was the same in each of the four corresponding pairs of straw and ‘no‐straw’ reactors. Straw bed priming enhanced the methane yield of the sugar beet leaves, with 0.33–0.37 m3 kg−1 VSadded (volatile solids) accumulated at average solid retention times as short as 11–25 days, while the ‘no‐straw’ reactors had lower yields at longer average solid retention times. The levels and speciation of the organic acids suggested that both the rate and extent of the anaerobic digestion of the sugar beet leaves added in the straw reactors were improved. At the highest loading rate, the straw reactor failed, while the ‘no‐straw’ reactor did not. It is hypothesised that the microbial biomass was better established in the straw reactors than in the ‘no‐straw’ reactors. Copyright © 2006 Society of Chemical Industry
Application of a silica gel prolonged‐release system for methanol in the production of biodiesel
Authors: Luo Yu , Wang Gang , Ma Yushu , Wei Dongzhi 
Published: October 2006

AbstractA silica gel‐based prolonged‐release system for methanol was applied in biodiesel production catalyzed by lipase LipB68, instead of the traditional method of three‐step addition of methanol. With the application of the prolonged‐release system, the recycle times of the catalyst increased substantially from one‐off usage to at least six cycles with no detectable decrease in activity, and the yield of biodiesel (94%) remained at a higher level compared with the yield of 92% with the previous method. The results showed the potential of this methanol addition method with little harm to the catalyst. Copyright © 2006 Society of Chemical Industry
High hydrostatic pressure enhances whey protein digestibility to generate whey peptides that improve glutathione status in CFTR‐deficient lung epithelial cells
Authors: Vilela Regina Maria , Lands Larry C. , Chan Hing M. , Azadi Behnam , Kubow Stan 
Published: October 2006

AbstractWhey protein isolates (WPI) may provide anti‐inflammatory benefits to cystic fibrosis (CF), which could be mediated via peptides, as proteolytic digests of WPI enhance intracellular glutathione (GSH) concentrations. The objectives of this study were to investigate whether high hydrostatic pressure can (i) improve the in vitro digestibility of WPI; and (ii) generate low molecular weight (< 1 kDa) peptides from WPI hydrolysates that exert GSH‐enhancing and anti‐inflammatory properties in wild type and mutant CF transmembrane conductance regulator (CFTR) tracheal epithelial cells. Hydrostatic pressure processing enhanced the in vitro digestibility of WPI to proteolytic enzymes resulting in altered peptide profiles as assessed by CZE and GC‐MS. The exposure of mutant CFTR cells to low molecular weight (< 1 kDa) peptides isolated from WPI hydrolysates exposed to pressure processing (pressurized WPI hydrolysates, pWPH), showed increased intracellular levels of reduced GSH and total GSH relative to treatment with peptides obtained from native WPI hydrolysates (nWPH). A tendency for decreased interleukin‐8 secretion was associated with the pWPH and nWPH treatments in mutant CFTR cells, which was not observed in wild type cells. Hydrostatic pressure processing of whey proteins appears to enhance their impact on cellular GSH status in cells with the mutant CFTR condition.
Thermal properties and toughness performance of hyperbranched‐polyimide‐modified epoxy resins
Authors: Jin Fan‐Long , Park Soo‐Jin 
Published: October 2006

AbstractAn amine‐terminated hyperbranched polyimide (HBPI) was prepared by the condensation polymerization of a commercially available triamine monomer with a dianhydride monomer. The effects of the HBPI content on the thermal and mechanical interfacial properties of diglycidyl ether of bisphenol A (DGEBA) epoxy resins were investigated with several techniques. The thermogravimetric analysis results showed that the thermal stability of the DGEBA/HBPI blends did not obviously change as the HBPI content increased. The glass‐transition temperature (Tg) of the DGEBA/HBPI blends increased with the addition of HBPI. Improvements in the critical stress intensity factor (KIC) and impact strength of the blends were observed with the addition of HBPI. The KIC value and impact strength were 2.5 and 2 times the values of the neat epoxy resins with only 4 wt % HBPI. The fractured surfaces were studied with scanning electron microscopy to investigate the morphology of the blends, and they showed that shear deformation occurred to prevent the propagation of cracks in the DGEBA/HBPI blends. These results indicated that a toughness improvement was achieved without a decrease in the thermal stability or Tg. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3348–3356, 2006
The relation between phosphine sorption and terminal gas concentrations in successful fumigation of food commodities
Authors: Vanitha Reddy Palvai , Rajashekar Yellappa , Begum Khamrunissa , Chandrappa Leelaja Bhadravathi , Rajendran Somiahnadar 
Published: October 2006

AbstractOwing to increased tolerance and the development of resistance in stored product insects to the fumigant phosphine, in recent years there has been a shift in the target terminal concentration from 100 ppm (100 mL m−3) to a higher level of 1000 ppm to achieve 100% insect mortality in 7 day commodity treatments. Therefore, there is a need to investigate whether the revised target concentration could be achieved for food commodities fumigated with phosphine at the standard dose of 2 g m−3 for 7 days under airtight conditions at ≥ 25°C. When different types of food commodity (total 74) were fumigated (300 g per replicate) with phosphine at 2 g m−3 for 7 days, the terminal gas concentrations in the free space of the commodities varied from 0 to > 2000 ppm. In chambers containing no substrate, a 1417 ppm concentration was recorded. Paddy rice, most of the oilseeds, shelled tree nuts, butter beans, cardamom, green gram splits, coriander powder, rice bran and cocoa powder were more sorptive (≥60%), such that the target concentration of 1000 ppm was not achieved at the end of 7 days. For these commodities, increased doses of 3–6 g m−3 were required to attain 1000 ppm. In‐shell almonds, green cardamom, in‐shell peanuts, leaf tea, tamarind pulp and sunflower seeds were exceptionally sorptive (>90%), so that 0, 41, 112, 168, 203 and 217 ppm respectively were noted at the end of 7 days; the dose must exceed 6 g m−3 for effective fumigation of these commodities. Copyright © 2006 Society of Chemical Industry
Electrospray tandem mass spectrometry of alkali‐cationized BocN‐carbo‐α,β‐ and ‐β,α‐peptides: differentiation of positional isomers
Authors: Reddy P. Nagi , Srikanth R. , Srinivas R. , Sharma V. U. M. , Sharma G. V. M. , Nagendar P. 
Published: October 2006

AbstractDissociation pathways of a series of alkali‐cationized hybrid peptides, viz., Boc‐α,β‐ and ‐β,α‐carbopeptides, synthesized from C‐linked carbo‐β3‐amino acids [Caa (S)] and α‐alanine (L‐Ala), have been investigated by electrospray ionization tandem mass spectrometry. The positional isomers (six pairs) of the cationized α,β‐ and β,α‐peptides can be differentiated by the collision‐induced dissociation (CID) spectra of their [M + Cat‐Boc + H]+ ions which give characteristic series of alkali‐cationized C‐ (x, y, z) and N‐terminal (a, b, c) ions. Another noteworthy difference is cationized β,α‐peptides eliminate a molecule of ammonia whereas this pathway is absent for α,β‐peptides. This is useful for identifying the presence of a β‐amino acid at the N‐terminus. The CID spectra of [M + Cat‐Boc + H]+ ions of these peptide acids show abundant rearrangement [bn + 17 + Cat]+ (n = 1 to n–1) ions which is diagnostic for distinguishing between α‐ and β‐amino acid at the C‐terminus. MSn experiments of [bn + Li–H]+ ions from these hybrid peptides showed the loss of CO and 72 u giving rise to [an + Li–H]+ and cationized nitrile product ions which render support to earlier proposals that b or [bn + Cat–H]+ ions have protonated or cationized oxazolinone structures, respectively. Copyright © 2006 John Wiley & Sons, Ltd.
Hepatitis E virus
Authors: Panda Subrat Kumar , Thakral Deepshi , Rehman Shagufta 
Published: October 2006

AbstractHepatitis E virus (HEV) is the aetiological agent of non‐HAV enterically transmitted hepatitis. It is the major cause of sporadic as well as epidemic hepatitis, which is no longer confined to Asia and developing countries but has also become a concern of the developed nations. In the Indian subcontinent, it accounts for 30–60% of sporadic hepatitis. It is generally accepted that hepatitis E is mostly self‐limited and never progresses to chronicity. It has a higher mortality in pregnant women where the disease condition is accentuated with the development of fulminant liver disease. Currently, no antiviral drug or vaccine is licensed for HEV, although a vaccine candidate is in clinical trials. HEV genome is 7.2kb in size with three open reading frames (ORFs) and 5′ and 3′ cis acting elements, which have important roles to play in HEV replication and transcription. ORF1 codes for methyl transferase, protease, helicase and replicase; ORF2 codes for the capsid protein and ORF3 for a protein of undefined function. HEV has recently been classified in the genus Hepevirus of the family Hepeviridae. There are four major recognised genotypes with a single known serotype. The absence of a reliable in vitro propagation system is an obstacle to deciphering HEV biology. The genome of HEV has been cloned, sequenced and the infectious nature of these replicons has been established. However, questions related to replication, transcription, virus‐host interactions and pathogenesis remain to be answered. This comprehensive review summarises the progress made so far in HEV research, and addresses some of the unanswered questions. Copyright © 2006 John Wiley & Sons, Ltd.
Polynomial control: past, present, and future
Authors: Kučera Vladimír 
Published: October 2006

AbstractPolynomial techniques have made important contributions to systems and control theory. Engineers in industry often find polynomial and frequency domain methods easier to use than state equation‐based techniques. Control theorists show that results obtained in isolation using either approach are in fact closely related.Polynomial system description provides input–output models for linear systems with rational transfer functions. These models display two important system properties, namely poles and zeros, in a transparent manner. A performance specification in terms of polynomials is natural in many situations; see pole allocation techniques.A specific control system design technique, called polynomial equation approach, was developed in the 1960s and 1970s. The distinguishing feature of this technique is a reduction of controller synthesis to a solution of linear polynomial equations of a specific (Diophantine or Bézout) type.In most cases, control systems are designed to be stable and meet additional specifications, such as optimality and robustness. It is therefore natural to design the systems step by step: stabilization first, then the additional specifications each at a time. For this it is obviously necessary to have any and all solutions of the current step available before proceeding any further.This motivates the need for a parametrization of all controllers that stabilize a given plant. In fact this result has become a key tool for the sequential design paradigm. The additional specifications are met by selecting an appropriate parameter. This is simple, systematic, and transparent. However, the strategy suffers from an excessive grow of the controller order.This article is a guided tour through the polynomial control system design. The origins of the parametrization of stabilizing controllers, called Youla–Kučera parametrization, are explained. Standard results on reference tracking, disturbance elimination, pole placement, deadbeat control, H2 control, l1 control and robust stabilization are summarized. New and exciting applications of the Youla–Kučera parametrization are then discussed: stabilization subject to input constraints, output overshoot reduction, and fixed‐order stabilizing controller design. Copyright © 2006 John Wiley & Sons, Ltd.
Blind identification of polynomial matrix fraction via independent component analysis
Authors: Nitta Masuhiro , Sugimoto Kenji 
Published: October 2006

AbstractThis paper proposes a method for blind system identification based on independence of input signals. Under the assumption that the system is multi‐input multi‐output, square, and represented by a polynomial matrix fraction with constant numerator matrix, the method makes it possible to identify the system parameter without observation of input signals. This rather challenging problem is solved by applying independent component analysis to an augmented state‐space representation in order to estimate coefficients of the denominator polynomial matrix and the numerator matrix. After giving this blind system identification algorithm, the paper shows how the proposed method is used in application. The first issue is suppression of disturbance with unknown dynamics. Assuming that a disturbance enters into a system independently of the control input signals, the method identifies a denominator polynomial matrix of the disturbance dynamics. Then an H∞ controller is designed in order to suppress the effect of the disturbance. The second is fault detection of mechanical systems subject to vibration from the environment. The vibration source is assumed to be unmeasurable, and yet the method achieves detection of a parameter change of the system due to fault. Copyright © 2006 John Wiley & Sons, Ltd.
Cajal bodies and interchromatin granule clusters in cricket oocytes: Composition, dynamics and interactions
Authors: Stepanova Irina S. , Bogolyubov Dmitry S. , Skovorodkin Ilya N. , Parfenov Vladimir N. 
Published: October 2006

AbstractThe organization and molecular composition of complicated Cajal bodies (CBs) and interchromatin granule clusters (IGCs) in oocytes of the house cricket, Acheta domesticus, were studied using immunofluorescent/confocal and Immunogold labeling/electron microscopy. In A. domesticus oocytes, the CB consists of the fibrillar matrix and a central cavity containing a predominantly granular body with insertions of tightly packed fibrillar material. The latter structure was identified as an “internal” IGC, since it is enriched with the SC35 protein, a marker for IGCs. The IGCs located outside the CB were also identified. Microinjections of the fluorescein‐tagged U7 snRNA into the ooplasm showed the targeting of the U7 to the matrix of the CB. Some other essential CB components (coilin, snRNPs, fibrillarin) were found to be colocalized in the matrix of the CB. Neither confocal nor Immunogold microscopy revealed significant amounts of RNA polymerase II (pol II) in the CB of A. domesticus oocytes. The splicing factor SC35 was detected in the matrix of the CB. In oocytes treated with DRB, the amount of IGCs in the nucleoplasm increased significantly, granular and fibrillar components of IGCs were segregated, and the fibrillar areas accumulated pol II. Additionally, IG‐like granules were shown to display on the surface of the CB probably due to a shifting from the internal IGC. We believe that in A. domesticus oocytes, CBs are involved in nuclear distribution of splicing factors, but their role in pol II transport is less significant. We also suggest that the formation of complicated CBs is a result of interconnection between two different nuclear domains, CBs and IGCs.
Evaluation of aneuploidy frequency for chromosomes 6 and 17 in eyelid tumours using the FISH technique
Authors: Özkağnici Ahmet , Acar Hasan , Zengin Nazmi , Okudan Süleyman 
Published: October 2006

AbstractAlthough basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are very common skin tumours, the incidence of chromosome aneuploidy with regard to the eyelid has not been investigated. We aimed to find the frequency of chromosome 6 and 17 aneuploidies in eyelid tumours' interphase nuclei with fluorescence in situ hybridization (I‐FISH) with chromosome specific DNA probes. I‐FISH with chromosome 6 and 17 centromere specific DNA probes was used in the eyelids of 10 patients with BCC or SCC and the peripheral blood cells of 10 healthy donors as controls. The frequency of chromosome 6 and 17 aneuploidies was significantly higher in 7 out of 10 patients and 5 out of 10 patients, respectively, than in controls, indicating a higher frequency of aneuploidy in BCC than in SCC of the eyelid. Distribution of hybridization signals for chromosome 6 and 17 was wide ranging, indicating heterogeneity of cell populations with aneuploidy between patients. These findings indicate that acquisition of chromosome aneuploidies in eyelid tumours may have an important pathogenic role in both BCC and SCC of the eyelid area.
In vitro effect of biogenic amines on the hormone content of immune cells of the peritoneal fluid and thymus. Is there a hormonal network inside the immune system?
Authors: Csaba G. , Kovács P. , Pállinger Éva 
Published: October 2006

AbstractImmune cells contain different hormones and hormone‐like molecules, such as insulin, endorphin, triiodothyronine (T3) histamine, serotonin. In earlier in vitro experiments insulin down‐regulated histamine, serotonin and T3 content of thymus cells. Now we studied the effect of biogenic amines on the endorphin, T3, serotonin and histamine content of rat peritoneal and thymic cells. Cells were obtained from male rats of 100 g body weight. 100 ng/ml serotonin or 300 ng/ml histamine was added for 30 min. After that the cells were prepared for flow cytometric analysis with antibodies to endorphin, T3, histamine and serotonin as primary antibodies and anti‐rabbit IgG as secondary antibody. Finishing the measurements the cells were also studied by confocal microscopy. T3 concentration (binding of anti‐T3 antibody) increased in peritoneal mast cells after serotonin treatment and in the monocyte‐macrophage‐granulocyte group after histamine treatment. Thymocytes' T3 content radically decreased after both treatments. Serotonin and histamine treatment also radically reduced the amine content of each other. Endorphin level was resistant to hormonal treatments. The results call attention to a possible hormonal network inside the immune system in which hormones produced by the immune cells themselves can influence each other.
The volume of the solution is 1 kg: Pleading for scientific writing
Authors: Sander Rolf 
Published: October 2006

“The volume of the solution is 1 kg.”Something is wrong with this statement. Volume can be expressed in liters but not in kilograms. It doesn't help much to say that aqueous solutions have a density of about 1 kg/L and that it doesn't matter much whether you say “l kg” or “1 L.” The fact remains that the statement is wrong. Fortunately, none of us would write a sentence like this for publication. Tropospheric chemists, however, have a similar habit: “The ozone concentration is 40 ppb.”
Lowering the stakes at the South Pole
Authors: Showstack Randy 
Published: October 2006

“For certain, I will never forget where I was on New Years Day, January 1,2000,” Larry Hothem recently e‐mailed Eos from Antarctica. Hothem, who heads up the U.S. Geological Surveys (USGS) geodetic team that is deployed annually to the McMurdo Station‐South Pole region, that morning was piling a stake into the ice above the most recent and most accurate location of the mean South Pole (the Earth's mean axis of rotation).At midnight, a makeshift band played, and several hundred scientists, construction workers, and support staff who normally devote their time to important research efforts and keeping the station operating smoothly sipped champagne in the −26°C temperature. At 4:30 a.m. local time, the revelers already had been awake for more than 22 hours as Hothem pounded in the marker and the British Broadcasting Corporation (BBC) aired the event live.