bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of a Thermostable Glucose Dehydrogenase by a Structure‐Guided Consensus Concept
Authors: Vázquez‐Figueroa Eduardo , Chaparro‐Riggers Javier , Bommarius Andreas S. 
Published: November 2007

AbstractInstability under non‐native processing conditions, especially at elevated temperatures, is a major factor preventing the widespread adoption of biocatalysts for industrial synthesis. A crucial distinction of many redox enzymes used to synthesize chiral compounds is the need for cofactors (e.g., NAD(P)(H)) for function. Because of the prohibitively high prices of nicotinamide cofactors, a robust cofactor‐regenerating enzyme is required for the economical synthesis of fine chemicals by biocatalysis. Here we test the structure‐guided consensus for the generation of a thermostable glucose dehydrogenase (GDH). The consensus sequence in combination with additional knowledge‐based criteria was used to select amino acids for substitutions. Using this approach we generated 24 variants, 11 of which showed higher thermal stability than the wild‐type GDH, a success rate of 46 %. Of the 24 variants, seven were located at the subunit interface—known to influence GDH stability—and six were more stable (86 % success). The best variants feature a half‐life of ∼3.5 days at 65 °C, in contrast to ∼20 min at 25 °C for the wild type, thus enhancing stability 106‐fold. In addition, the three most stabilizing single mutations were transferred to two GDH homologues from Bacillus thuringiensis and Bacillus licheniformis. The thermal stability as measured by half‐life and CD222 nm of the GDH variants was increased, as expected. The resulting stability changes provide further support for the view that these residues are critical for stability of GDHs and reinforce the success of the consensus approach for identifying stabilizing mutations.
Heterogeneous output pathways link the anterior pretectal nucleus with the zona incerta and the thalamus in rat
Authors: Giber Kristóf , Slézia Andrea , Bokor Hajnalka , Bodor Ágnes L. , Ludányi Anikó , Katona István , Acsády László 
Published: November 2007

AbstractThe anterior pretectal nucleus (APT) and the zona incerta (ZI) are diencephalic nuclei that exert a strong inhibitory influence selectively in higher order thalamic relays. The APT is also known to project to the ZI as well as the thalamus, but anatomical details of the APT‐ZI projection have not been described. In the present study, the efferent pathways of the APT were examined in the APT‐ZI‐thalamus network by using anterograde and retrograde tracing in combination with pre‐ and postembedding immunocytochemical stainings and in situ hybridization. The vast majority of APT fibers selectively innervated the parvalbumin‐positive, ventral part of the ZI, which contains ZI neurons with axons projecting to higher order thalamic nuclei. The APT‐ZI pathway consisted of both γ‐aminobutyric acid (GABA)‐negative and GABA‐positive components; 38.2% of the terminals in the ZI contained GABA, and 8.6% of the projecting somata in the APT were glutamic acid decarboxylase 67 (GAD67) mRNA positive. The combination of parvalbumin immunostaining with retrograde tracing showed that strongly and weakly parvalbumin‐positive as well as parvalbumin‐negative neurons were all among the population of APT cells projecting to the ZI. Similar heterogeneity was found among the APT cells projecting to the thalamus. Double retrograde tracing from higher order thalamic nuclei and their topographically matched ZI regions revealed hardly any APT neuron with dual projections. Our data suggest that both ZI and the higher order thalamic relays are innervated by distinct, physiologically heterogeneous APT neurons. These various efferent pathways probably interact via the rich recurrent collaterals of the projecting APT cells. Therefore, the powerful, GABAergic APT and ZI outputs to the thalamus are apparently co‐modulated in a synergistic manner via dual excitatory and inhibitory APT‐ZI connections. J. Comp. Neurol. 506:122–140, 2008. © 2007 Wiley‐Liss, Inc.
The Microwave Concentrator Stack: A Source for Free‐Standing, Linearly Extended Plasmas
Authors: Schweitzer U. , Schulz A. , Walker M. , Baumgärtner K.‐M. , Muegge H. , Schumacher U. , Stroth U. 
Published: November 2007

AbstractA new type of plasma source, the Microwave Concentrator Stack, presented in this paper is a device of a geometry that can be described as an elliptical cylinder with additional metallic structures for shaping the electric field in its inside. The basic idea is to concentrate the electric field strength of microwaves on one of its focal lines by coupling microwave power into it on the other focal line. Even though the dimensions of the Concentrator Stack are too small compared to the wavelength of the microwaves to assume wave‐optics behavior, a pronounced maximum of the electric field intensity is created on the focal line.By placing an evacuated glass tube around the focal line, free‐standing plasmas can be generated by the strong electric field. In the low pressure range (10 to 200 Pa), the plasma displays very good one‐dimensional homogeneity along the focal line of the Concentrator Stack. At higher pressures the plasma contracts to several ball‐shaped discharges, whose positions correspond to the aforementioned metallic structures inside the Concentrator Stack.The electric field distribution was calculated and optimized for various versions of the Concentrator Stack using the finite element software Comsol MultiphysicsTM and also measured with PET absorber sheets. Measurements and calculations are in excellent agreement. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Erosion Behaviour of Metal‐Doped Carbon Layers in Deuterium Low Pressure Plasmas and the Determination by Optical Emission Spectroscopy
Authors: Starke P. , Adelhelm C. , Balden M. 
Published: November 2007

AbstractThe erosion behaviour of doped carbon materials was investigated in deuterium low pressure discharges. Therefore, amorphous carbon films on silicon substrates (film thickness ∼1 μm) with varying dopant species (V, Ti andW), dopant concentration (between 1 at% and 8.5 at%) and dopant distribution were exposed to the plasma. The dopant distribution is either atomically disperse or, by heating up to 1100 K, carbide grains in nm size are formed. All important plasma parameters are obtained by a combination of several diagnostic techniques like optical emission spectroscopy, energy resolved mass spectroscopy and Langmuir probe measurements. The morphology of the plasma treated surfaces was investigated afterwards by scanning electron microscopy and atomic force microscopy, the layer composition by ion beam analysis. Every investigated sample shows a strong decrease of the erosion yield with increasing fluence. The achieved erosion yields are clearly below the yield of undoped amorphous carbon and depend strongly on the dopant concentration. The lowest yields were achieved with the samples with atomically disperse dopant distribution due to metal enrichment at the surface. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Novel (3,4)‐ and (4,5)‐Connected Lanthanide Metal–Organic Frameworks
Authors: Wang Xian‐Wen , Li Xing , Chen Jing‐Zhong , Zheng Guang , Hong Han‐Lie 
Published: November 2007

AbstractThe three‐dimensional lanthanide noninterpenetrating metal–organic frameworks formulated as [Ln(3,5‐pdc)(C2O4)0.5(H2O)2]·H2O (Ln = LuIII, GdIII, TmIII and YbIII for complex 1–4, respectively; 3,5‐pdc = 3,5‐pyridinedicarboxylate) were synthesized by hydrothermal reactions of 3,5‐H2pdc with lanthanide oxide and perchloric acid. Compound 1 shows (3,4)‐connected (4.82)(4.85) dmc‐type topological network, and complexes 2–4 display the novel (4,5)‐connected (44.6.8)(44.62.84) xww‐type topology. The lanthanide‐mediated transformation of CO2 to oxalate under hydrothermal conditions was observed. The fluorescence properties of complexes 1–4 were investigated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis of 5‐(2‐Pyrenyl)‐2′‐deoxyuridine as a DNA Modification for Electron‐Transfer Studies: The Critical Role of the Position of the Chromophore Attachment
Authors: Wanninger‐Weiß Claudia , Wagenknecht Hans‐Achim 
Published: November 2007

Abstract5‐(2‐Pyrenyl)‐2′‐deoxyuridine (2PydU, 2) has been prepared as a new thymidine analogue in which the 2‐position of the pyrene chromophore is connected covalently to the 5‐position of uridine through a single C–C bond. The synthesis of 2 starts with the conversion of pyrene (3) into 2‐(4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)pyrene (4) by using an Ir catalyst that was prepared in situ from [IrCl(cod)]2 and 4,4′‐di‐tert‐butyl‐2,2′‐bipyridine (dtbpy) in the presence ofNaOMe. The subsequent Suzuki–Miyaura cross‐coupling of 4 with 5‐iodo‐2′‐deoxyuridine (5) was performed by using1,1′‐bis[(diphenylphosphanyl)ferrocene]dichloropalladium(II) as the catalyst in a THF/MeOH/H2O mixture as the solvent. The modified nucleoside 2 was characterized by absorption and fluorescence spectroscopy. The results were compared with the strongly electronically coupled 5‐(1‐pyrenyl)‐2′‐deoxyuridine (1PydU, 1). Finally, the nucleoside 2 was converted into the corresponding phosphoramidite 7 as a DNA building block. The DNA set 8a–8d was synthesized to explore the optical properties of the 2PydU label in duplex DNA with respect to the counterbase opposite the 2PydX modification site and in comparison with 1PydU‐modified DNA. The studies with the 2PydU nucleoside and the 2PydU‐modified DNA clearly allow the conclusion to be drawn that the pyrene and the uridine moieties, as the two aromatic groups in this modified nucleoside, are only weakly electronically coupled. Accordingly, the 2PydU label behaves optically like a pyrene derivative, in contrast to the 1PydU label. The chromophore shows the ability for Watson–Crick base‐pairing inside the DNA, as revealed by the absorption and fluorescence spectra. 2PydU represents an optical label for DNA that changes its absorption properties upon DNA hybridization and undergoes fluorescence quenching by charge transfer.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
A case study of environmental management in PowerGen
Authors: Barrett George 
Published: November 2007

AbstractPowerGen has changed markedly since its creation as a private company. Old skills have been rationalised and new business activities have been acquired. At the same time environmental regulations have tightened with specific responsibilities being placed on directors. In response to these challenges PowerGen has developed a company‐wide environmental compliance policy. This incorporates an environmental management system and sets down minimum management standards. The Policy is supported by an environmental audit programme. PowerGen has participated in the development of standardised environmental management systems within BS7750 and the EU eco‐management and audit scheme. The company has yet to decide whether or not to subscribe to the schemes. Copyright © 1994 John Wiley & Sons, Ltd and ERP Environment.
Book reviews
Authors: Manning Sturt W. 
Published: November 2007

AbstractThe Plain of Phaistos: Cycles of Complexity in the Mesara Region of Crete. L. Vance Watrous, Despoina Hadzi‐Vallianou and Harriet Blitzer, 2004, Cotsen Institute of Archaeology, UCLA, Monumenta Archaeologica 23, Los Angeles, California, xxvi + 668 pp.
Quantifying prehistoric soil erosion—A review of soil loss methods and their application to a Celtic square enclosure (Viereckschanze) in Southern Germany
Authors: Leopold Matthias , Völkel Jörg 
Published: November 2007

AbstractThis paper discusses the strengths and weaknesses of three different methods for quantifying prehistoric soil erosion. Method A estimates erosion by determining the amount of colluvium stored downhill. Method B involves reconstructing a former erosion surface using truncated soil horizons. Method C compares the elevation of a paleosol beneath an earthwork with the modern surface in the surrounding area. Each method was applied to a Celtic earthwork (Viereckschanze) at Poign (near Regensburg) in Southern Germany in order to cross‐check the different results. For an erosion area of 3.6 ha and during 300 years of agricultural usage, Method A calculates a minimum erosion rate of 20.8 t/ha/a. Method B computes 10 t/ha/a of soil loss. Method C yields the highest rate of erosion with 24.2 t/ha/a. We have confidence in Method C, which implies an underassesment of soil loss in using methods A or B. © 2007 Wiley Periodicals, Inc.
Vitamin C supplementation does not protect L‐gulono‐γ‐lactone oxidase‐deficient mice from Helicobacter pylori‐induced gastritis and gastric premalignancy
Authors: Lee Chung‐Wei , Wang Xiang‐Dong , Chien Kuo‐Liong , Ge Zhongming , Rickman Barry H. , Rogers Arlin B. , Varro Andrea , Whary Mark T. , Wang Timothy C. , Fox James G. 
Published: November 2007

AbstractIn human studies, low vitamin C intake has been associated with more severe Helicobacter pylori gastritis and a higher incidence of gastric cancer. However, vitamin C supplementation has not been definitively shown to protect against gastric cancer. Using vitamin C‐deficient B6.129P2‐Gulotm1Umc/mmcd (gulo−/−) mice lacking L‐gulono‐γ‐lactone oxidase, we compared gastric lesions and Th1 immune responses in H. pylori‐infected gulo−/− mice supplemented with low (33 mg/L) or high (3,300 mg/L) vitamin C in drinking water for 16 or 32 weeks. Vitamin C levels in plasma and gastric tissue correlated with the vitamin C supplementation levels in gulo−/− mice. H. pylori infection resulted in comparable gastritis and premalignant lesions in wildtype C57BL/6 and gulo−/− mice supplemented with high vitamin C, but lesions were less severe in gulo−/− mice supplemented with low vitamin C at 32 weeks post infection. The reduced gastric lesions in infected gulo−/− mice supplemented with low vitamin C correlated with reduced Th1‐associated IgG2c, gastric IFN‐γ and TNF‐α mRNA and higher H. pylori colonization levels. These results in the H. pylori‐infected gulo−/− mouse model suggest that although supplementation with a high level of vitamin C achieved physiologically normal vitamin C levels in plasma and gastric tissue, this dose of vitamin C did not protect gulo−/− mice from H. pylori‐induced premalignant gastric lesions. In addition, less severe gastric lesions in H.pylori infected gulo−/− mice supplemented with low vitamin C correlated with an attenuated Th1 inflammatory response. © 2007 Wiley‐Liss, Inc.
Expression of iron‐related proteins during infection by bovine herpes virus type‐1
Authors: Maffettone Carmen , De Martino Luisa , Irace Carlo , Santamaria Rita , Pagnini Ugo , Iovane Giuseppe , Colonna Alfredo 
Published: November 2007

AbstractBovine herpesvirus 1 (BHV‐1), a dsDNA animal virus, is an economically important pathogen of cattle and the aetiological agent of many types of disease. The efficient replication of a DNA virus is strictly dependent on iron since this metal plays a crucial role in the catalytic center of viral ribonucleotide reductase. Consequently, iron metabolism is an important area for virus/host interaction and a large body of evidence suggests that viral infection is potentially influenced by the iron status of the host. The aim of the present study was to address the effects of BHV‐1 on iron metabolism in Madin‐Darby bovine kidney (MDBK) cells at different times of post‐infection. For this purpose, cell viability, iron regulatory proteins (IRPs) activity and levels, transferrin receptor 1 (TfR‐1), ferritin expression and LIP were evaluated. Our data demonstrate that a productive BHV‐1 infection in MDBK cells determines an overall decrease of IRPs RNA‐binding activity without affecting their expression. As consequence of this modulation, an increased ferritin mRNA translation and a decreased TfR‐1 mRNA translation were also observed. Moreover, the LIP level was decreased following viral infection. These results are consistent with the hypothesis that by reducing the iron up‐take and by enhancing the sequestration of free iron, animal cells will limit the iron availability for virus proliferation. Therefore, the results presented herein support the view that iron metabolism could be critical for the interaction between DNA viruses, such as BHV‐1, and mammalian cells. Delineation of the interplay among pathogen and host may provide new antimicrobial agents. J. Cell. Biochem. 104: 213–223, 2008. © 2007 Wiley‐Liss, Inc.
Physiology of the motor cortex in polio survivors
Authors: Lupu Vitalie D. , Danielian Laura , Johnsen Jacqueline A. , Vasconcelos Olavo M. , Prokhorenko Olga A. , Jabbari Bahman , Campbell William W. , Floeter Mary Kay 
Published: November 2007

AbstractWe hypothesized that the corticospinal system undergoes functional changes in long‐term polio survivors. Central motor conduction times (CMCTs) to the four limbs were measured in 24 polio survivors using transcranial magnetic stimulation (TMS). Resting motor thresholds and CMCTs were normal. In 17 subjects whose legs were affected by polio and 13 healthy controls, single‐ and paired‐pulse TMS was used to assess motor cortex excitability while recording from tibialis anterior (TA) muscles at rest and following maximal contraction until fatigue. In polio survivors the slope of the recruitment curve was normal, but maximal motor evoked potentials (MEPs) were larger than in controls. MEPs were depressed after fatiguing exercise. Three patients with central fatigue by twitch interpolation had a trend toward slower recovery. There was no association with symptoms of post‐polio syndrome. These changes occurring after polio may allow the motor cortex to activate a greater proportion of the motor neurons innervating affected muscles. Muscle Nerve, 2007
Reappraisal of biosafety risks posed by PERVs in xenotransplantation
Authors: Louz Derrick , Bergmans Hans E. , Loos Birgit P. , Hoeben Rob C. 
Published: November 2007

AbstractDonor materials of porcine origin could potentially provide an alternative source of cells, tissues or whole organs for transplantation to humans, but is hampered by the health risk posed by infection with porcine viruses. Although pigs can be bred in such a way that all known exogenous microorganisms are eliminated, this is not feasible for all endogenous pathogens, such as the porcine endogenous retroviruses (PERVs) which are present in the germline of pigs as proviruses. Upon transplantation, PERV proviruses would be transferred to the human recipient along with the xenograft. If xenotransplantation stimulates or facilitates replication of PERVs in the new hosts, a risk exists for adaptation of the virus to humans and subsequent spread of these viruses. In a worst‐case scenario, this might result in the emergence of a new viral disease. Although the concerns for disease potential of PERVs are easing, only limited pre‐clinical and clinical data are available. Small‐scale, well‐designed and carefully controlled clinical trials would provide more evidence on the safety of this approach and allow a better appreciation of the risks involved. It is therefore important to have a framework of protective measures and monitoring protocols in place to facilitate such initially small scale clinical trials. This framework will raise ethical and social considerations regarding acceptability. Copyright © 2007 John Wiley & Sons, Ltd.
Caloplaca fuscorufa—a misunderstood species in northern Europe
Authors: ARUP Ulf , ARNENG Emma , SØCHTING Ulrik 
Published: November 2007

Abstract:Caloplaca fuscorufa H. Magn. is a poorly known species that for a long time was known only from a single locality in Jämtland, northern Sweden, where it was collected in 1910. It has been suggested to be synonymous with C. crenularia (With.) J. R. Laundon, but has also been confused with C. exsecuta (Nyl.) Dalla Torre & Sarnth. We have compared the isotype of C. fuscorufa and material collected in Sweden, Norway and Svalbard, with presumably related species, using morphology, anatomy and chemistry as well as molecular data. The results show that C. fuscorufa is a distinct species, differing from C. crenularia mainly in its somewhat larger spores with wider septa, different colour of the apothecia and a more northern distribution. It differs from C. exsecuta mainly in its chemistry and smaller spores with smaller septa. Caloplaca crenularia is shown to have a more southern distribution in Sweden than previously understood. Chemical data and a molecular analysis based on ITS data show that C. fuscorufa is related to C. crenularia and C. ammiospila, but clearly separated from these species.
A new species of Xanthoparmelia (Ascomycota: Parmeliaceae) from the Canary Islands
Authors: PÉREZ-VARGAS Israel , HERNÁNDEZ-PADRÓN Consuelo , ELIX John A. 
Published: November 2007

Abstract:Xanthoparmelia perezdepazii from the Canary Islands is described as new to science. It is characterized by an isidiate upper surface, the presence of usnic, constipatic and protoconstipatic acids in the medulla and a brown lower surface.
D. Z. Phillips on God and evil
Authors: HICK JOHN 
Published: November 2007

AbstractThis a response to D. Z. Phillips's stringent critique of theodicies, including that suggested by myself. I offer counters to his array of arguments, and point to what I see as a fundamental flaw in his philosophy of religion. He appealed to religious language as used by ordinary religious persons. But his account of the meaning of this language was not that of the ordinary religious believer. He thus claimed, by implication, to know better than they did what they really meant. I conclude that he was a non-realist concerning both religious language and the reality of God.
Effect of acetazolamide on leg endurance exercise at sea level and simulated altitude
Authors: Fulco Charles S. , Muza Steven R. , Ditzler Dan , Lammi Eric , Lewis Steven F. , Cymerman Allen 
Published: November 2007

Acetazolamide can be taken at sea level to prevent acute mountain sickness during subsequent altitude exposure. Acetazolamide causes metabolic acidosis at sea level and altitude, and increases SaO2 (arterial oxygen saturation) at altitude. The aim of the present study was to determine whether acetazolamide impairs muscle endurance at sea level but not simulated altitude (4300 m for &lt;3 h). Six subjects (20±1 years of age; mean±S.E.M.) performed exhaustive constant work rate one-leg knee-extension exercise (25±2 W) once a week for 4 weeks, twice at sea level and twice at altitude. Each week, subjects took either acetazolamide (250 mg) or placebo orally in a double-blind fashion (three times a day) for 2 days. On day 2, all exercise bouts began approx. 2.5 h after the last dose of acetazolamide or placebo. Acetazolamide caused similar acidosis (pH) in all subjects at sea level (7.43±0.01 with placebo compared with 7.34±0.01 with acetazolamide; P&lt;0.05) and altitude (7.48±0.03 with placebo compared with 7.37±0.01 with acetazolamide; P&lt;0.05). However, endurance performance was impaired with acetazolamide only at sea level (48±4 min with placebo compared with 36±5 min with acetazolamide; P&lt;0.05), but not altitude (17±2 min with placebo compared with 20±3 min with acetazolamide; P=not significant). In conclusion, lack of impairment of endurance performance by acetazolamide compared with placebo at altitude was probably due to off-setting secondary effects resulting from acidosis, e.g. ventilatory induced increase in SaO2 for acetazolamide compared with placebo (89±1 compared with 86±1% respectively; P&lt;0.05), which resulted in an increased oxygen pressure gradient from capillary to exercising muscle.