bluuebunny/crossref_metadata_2025 huggingface dataset:
A numerical fit of analytical to simulated density profiles in dark matter haloes
Authors: Caimmi R. , Marmo C. , Valentinuzzi T.
Published: August 2005

Analytical and geometrical properties of generalized power-law (GPL) density profiles are investigated in detail. In particular, a one-to-one correspondence is found between mathematical parameters (a scaling radius, r0, a scaling density, ?0, and three exponents, ?, ?, ?), and geometrical parameters (the coordinates of the intersection of the asymptotes, xC, yC, and three vertical intercepts, b, b?, b?, related to the curve and the asymptotes, respectively): (r0,?0,?,?,?) ? (xC,yC,b,b?,b?). Then GPL density profiles are compared with simulated dark haloes (SDH) density profiles, and nonlinear least-absolute values and least-squares fits involving the above mentioned five parameters (RFSM5 method) are prescribed. More specifically, the sum of absolute values or squares of absolute logarithmic residuals, Ri=log?SDH(ri) ? log?GPL(ri), is evaluated on 10 points making a 5dimension hypergrid, through a few iterations. The size is progressively reduced around a fiducial minimum, and superpositions on nodes of earlier hypergrids are avoided. An application is made to a sample of 17 SDHs on the scale of cluster of galaxies, within a flat ?CDM cosmological model (Rasia et al. 2004). In dealing with the mean SDH density profile, a virial radius, Rvir, averaged over the whole sample, is assigned, which allows the calculation of the remaining parameters. Using a RFSM5 method provides a better fit with respect to other methods. The geometrical parameters, averaged over the whole sample of best fitting GPL density profiles, yield (?, ?, ?) ? (0.6,3.1,1.0), to be compared with (?, ?, ?) = (1,3,1), i.e. the NFW density profile (Navarro et al. 1995, 1996, 1997), (?, ?, ?) = (1.5,3, 1.5) (Moore et al. 1998, 1999), (?, ?, ?) = (1,2.5,1) (Rasia et al. 2004); and, in addition, ? ? 1.5 (Hiotelis 2003), deduced from the application of a RFSM5 method, but using a different definition of scaled radius, or concentration; and ? ? 1.21.3 deduced from more recent high-resolution simulations (Diemand et al. 2004, Reed et al. 2005). No evident correlation is found between SDH dynamical state (relaxed or merging) and asymptotic inner slope of the fitting logarithmic density profile or (for SDH comparable virial masses) scaled radius. Mean values and standard deviations of some parameters are calculated, and in particular the decimal logarithm of the scaled radius, ?vir, reads < log?vir >= 0.74 and ?slog?vir = 0.150.17, consistent with previous results related to NFW density profiles. It provides additional support to the idea, that NFW density profiles may be considered as a convenient way to parametrize SDH density profiles, without implying that it necessarily produces the best possible fit (Bullock et al. 2001). A certain degree of degeneracy is found in fitting GPL to SDH density profiles. If it is intrinsic to the RFSM5 method or it could be reduced by the next generation of high-resolution simulations, still remains an open question. .
Phase relations in the La2O3-TiO2-Al2O3 system
Authors: Skapin Sreco , Suvorov D.
Published: August 2005

A small amount of LaAlO3 added to a La2O3:3TiO2 starting oxide mixture stabilizes the A-deficient La2/3TiO3 perovskite structure. According to XRD and microstructural investigations of samples prepared in the ternary system at 1400?C, only the solid solution along the La2/3TiO3-LaAlO3 tie-line extends from at least 4 mol% LaAlO3 to pure LaAlO3.
The influence of mechanical activation on the process of reaction sintering of Portland cement clinker
Authors: Zivanovic Branka , Sreckovic Tatjana , Komljenovic M.
Published: August 2005

In this paper, results of an investigation of the influence of mechanical activation of a raw material mixture on processes of synthesis and reaction sintering of Portland cement clinker are given. Activation was performed in a vibro mill with rings for 30 minutes in a continual regime in air. It has been established that mechanical activation of the starting raw material mixture increases general activity, which is mostly reflected in reduction of temperatures at which relevant chemical reactions and sintering occur. This is very significant from the viewpoint of the increasingly necessary efficiency and cheaper production, i.e. energy savings during synthesis of Portland cement clinker and indicates that further investigation of the influence of mechanical activation is more than justified.
Modeling of coating optical fibers with polymer-magnetic powder composite coating
Authors: Milutinovic-Nikolic Aleksandra , Talijan Nadezda , Aleksic Radoslav
Published: August 2005

A mathematical model of forming a composite coating on optical fiber was established. The model is based on existing mathematical models for coating optical fibers with polymer coating and experimentally defined rheological behavior of the investigated dispersed system. The model was developed for a dispersed system consisting of poly(ethylene-co-vinyl acetate) - EVA in a form of toluene solution and powders of magnetic materials (BaFe12O19 and SmCo5). The influence of the die diameter, diameter of the original optical fiber, concentration of EVA and magnetic powders on the thickness of composite coating was investigated. The model shows good agreement with experimental data.
Modern concepts of conversion and storage of energy by dispersed materials absorption
Authors: Minic-Popovic Dragica , Susic M.V.
Published: August 2005

Once hydrogen is generated, the question asked: How do we store hydrogen? Hydrogen can be stored in a variety of ways, each with specific advantages and disadvantages. The overall criteria for choosing a storage method should be safety and ease of use. Described in this paper and listed below are different storage methods available today (compressed hydrogen, liquid carrier storage, glass microsphere, chemically stored hydrogen) in addition to some techniques that are still in the research and development stage: power balls, metal hydride tanks and carbon clusters.
Formation of irregular rings in silica aerogel structure during the sintering process
Authors: Hinic Ivana , Stanisic Goran , Popovic Zoran
Published: August 2005

Samples of low-density, highly disordered silica aerogel with initial bulk density of 0.16 g/cm3, were sintered isothermally in different time intervals at 1000?C. Structural changes during the sintering process have been investigated by Raman spectroscopy. Defect modes of irregular three and four membered rings were observed in the Raman spectra of sintered samples.
Obtaining of dense and highly porous ceramic materials from metallurgical slag
Authors: Fidancevska E. , Mangutova B. , Milosevski D. , Milosevski M. , Bossert J.
Published: August 2005

Glass-ceramics in a dense and highly porous form can be obtained from metallurgical slag and waste glass of TV monitors. Using polyurethane foam as pore creator, a highly porous system with porosity of 65 ? 5 %, E-modulus and flexural strength of 8 ? 3 GPa and 13 ? 3.5 MPa respectively can be obtained. This porous material had durability (mass loss) of 0.03 % in 0.1 M HCl that is identical with the durability of a dense composite.
Thermodynamic interpretation of a dihedral angle in composite materials
Authors: Lisovsky A.F.
Published: August 2005

The equilibrium between solid and 1iquid phases in sintered composite materials has been studied. It is shown that closed surfaces, which bound dispersed phases, influence the mechanical equilibrium between these phases. An expression is derived for a dihedral angle in composite materials, which includes values of surface tensions at the phase interfaces as well as parameters of a composite equilibrium structure (phase composition, particle contiguity and coefficients of a particle geometry).
Placental improvement and reduced distal limb defects by maternal interferon‐γ injection in methylnitrosourea‐exposed mice
Authors: Laudermilch Chelsea Lee , Holladay Steven David , Sponenberg Dan Phillip , Saunders Geoffrey Kirk , Ward Daniel Lee , Prater Mary Renee
Published: August 2005

Background

Methylnitrosourea (MNU), an alkylating agent derived from creatinine metabolism, is cytotoxic, genotoxic, and mutagenic. Midgestational exposure to MNU leads to distal limb defects in mice. Previous studies have shown that nonspecific maternal immune stimulation protects against MNU‐induced teratogenesis. A role for immune‐mediated placental improvement in this effect remains uncertain.

METHODS

The immune system of timed‐pregnant C57BL/6N and CD‐1 mice was stimulated by GD 7 intraperitoneal (IP) injection with the cytokine interferon‐γ (IFN‐γ). A teratogenic dose of MNU was then administered by IP injection on the morning of GD 9 to disrupt distal limb formation. Fetal limb length, body length, digital deformities, and placental integrity were evaluated on GD 14.

RESULTS

The incidence of syndactyly, polydactyly, and interdigital webbing in MNU‐exposed mice was decreased by maternal IFN‐γ treatment. In C57BL/6N mice, these defects were reduced by 47, 100, and 63%, respectively, as compared to previous reports on CD‐1 mice, by 39, 71, and 20%, respectively. Administration of IFN‐γ significantly diminished MNU‐induced endothelial and trophoblast placental damage in both strains of mice.

CONCLUSIONS

These findings support a possible link between maternal immunity, placental integrity, and fetal distal limb development. Further, these results suggest that IFN‐γ might act through placental improvement to indirectly protect against MNU‐induced fetal limb malformations. Birth Defects Research (Part A), 2005. © 2005 Wiley‐Liss, Inc.
Fluorescence anisotropy studies of molecularly imprinted polymers
Authors: Chen Yin‐Chu , Wang Zheming , Yan Mingdi , Prahl Scott A.
Published: August 2005

A molecularly imprinted polymer (MIP) is a biomimetic material that can be used as a biochemical sensing element. We studied the steady‐state and time‐resolved fluorescence and fluorescence anisotropy of anthracene‐imprinted polyurethane. We compared MIPs with imprinted analytes present, MIPs with the imprinted analytes extracted, MIPs with rebound analytes, non‐imprinted control polymers (non‐MIPs) and non‐MIPs bound with analytes to understand MIP's binding behaviour. MIPs and non‐MIPs had similar steady‐state fluorescence anisotropy in the range 0.11–0.24. Anthracene rebound in MIPs and non‐MIPs had a fluorescence lifetime of τ = 0.64 ns and a rotational correlation time of ϕF = 1.2–1.5 ns, both of which were shorter than that of MIPs with imprinted analytes present (τ = 2.03 ns and ϕF = 2.7 ns). The steady‐state anisotropy of polymer solutions increased exponentially with polymerization time and might be used to characterize the polymerization extent in situ. Copyright © 2005 John Wiley & Sons, Ltd.
Determination of norfloxacin using a terbium‐sensitized electrogenerated chemiluminescence method
Authors: Chen Shi‐Lv , Liu Yu , Zhao Hui‐Chun , Jin Lin‐Pei , Zhang Zhong‐Lun , Zheng Yan‐Zhen
Published: August 2005

A simple electrogenerated chemiluminescence (ECL) analysis method for the determination of norfloxacin (NFLX) is reported. It is based on ECL produced by Na2SO3, which is sensitized by the Tb–NFLX complex. The relative ECL intensity of the Tb3+–NFLX–Na2SO3 system is proportional to the amount of NFLX. The optimized experimental conditions were investigated. The linear range and detection limit for NFLX were 1.0 × 10−10–8.0 × 10−7 mol/L and 2.8 × 10−11 mol/L, respectively. This method was successfully applied to the determination of NFLX in a capsule. NFLX in urine can be directly detected without pretreatment or separation. Copyright © 2005 John Wiley & Sons, Ltd.
Production of phytoene by herbicide‐treated microalgae Dunaliella bardawil in two‐phase systems
Authors: León Rosa , Vila Marta , Hernánz Dolores , Vílchez Carlos
Published: August 2005

In the present study we have optimized the concentration of the bleaching herbicide norflurazon to obtain Dunaliella bardawil cells able to accumulate phytoene without losing viability. The highest concentration of phytoene 10.4 g/gChl was obtained for a concentration of norflurazon of 10 µg/mL. Norflurazon‐treated Dunaliella bardawil cells are able to accumulate high concentrations of phytoene if the carotenogenic pathway is stimulated, but the lack of colored carotenoids make these cells particularly sensitive to high light intensities and to UVB radiation, so other stimuli, such as nitrogen starvation, have to be used to force the accumulation of phytoene. Detailed time‐course evolution of the carotenoids lutein, violaxanthin, zeaxanthin, phytene and β‐carotene and the photosynthetic pigment chlorophyll was followed upon transfer of Dunaliella bardawil cells to nitrogen starvation in presence and absence of norflurazon. The combined use of the carotenogenic pathway inhibitor norflurazon and biphasic aqueous/organic systems to force the excretion of phytoene into the culture medium has been investigated. Cells cultured in the biphasic system were viable and able to produce phytoene during 3 days. Futhermore the productivity increased from 0.14 g/gChl · h in the aqueous culture to 0.18 g/gChl · h in the biphasic system. About 15% of the total phytoene produced by Dunaliella bardawil was excreted and immediately partionated into the organic phase. The concentration of phytoene in the decane phase was 2.05 g/gChl after 72 h, this means that about 47 g of phytoene per litre of culture were in the organic phase. © 2005 Wiley Periodicals, Inc.
C5 complement inhibition attenuates shock and acute lung injury in an experimental model of ruptured abdominal aortic aneurysm
Authors: Harkin D W , Marron C D , Rother R P , Romaschin A , Rubin B B , Lindsay T F
Published: August 2005

Background

Ruptured abdominal aortic aneurysm (RAAA) is associated with a systemic inflammatory response syndrome and multiple organ dysfunction. The potential role of a novel C5 complement inhibitor in attenuation of pathological complement activation and tissue injury was explored in a model of RAAA.

Methods

Anaesthetized rats were randomized to sham (control) or shock and clamp (SC) groups. Animals in the SC group underwent 1 h of haemorrhagic shock (mean arterial pressure 50 mmHg or less), 45 min of supramesenteric aortic clamping and 2 h of reperfusion. They were randomized to receive an intravenous bolus of a functionally blocking anti-C5 monoclonal antibody (C5 inhibitor), at a dose of 20 mg/kg, or saline. Lung injury was assessed by permeability to 125I-labelled albumin, tissue myeloperoxidase (MPO) activity, and semiquantitative reverse transcriptase–polymerase chain reaction (RT–PCR) for mRNAs encoding tumour necrosis factor (TNF) α and interleukin (IL) 6.

Results

The lung permeability index was significantly increased in the SC compared with the sham group (P = 0·032); this was prevented by the C5 inhibitor (P = 0·015). Lung MPO activity was significantly increased in the SC compared with the sham group (P < 0·001), and this increase was attenuated by treatment with the C5 inhibitor (P < 0·001). Semiquantitative RT–PCR in SC group demonstrated downregulation of TNF-α mRNA (P = 0·050) and upregulation of IL-6 mRNA (P < 0·001), which were both prevented by the C5 inhibitor (P = 0·014 and P < 0·001 respectively).

Conclusion

These results indicated that C5 complement inhibition can reduce shock and acute lung injury in an experimental model of RAAA.
Policy instruments for sustainability‐oriented organizational learning
Authors: Müller Martin , Siebenhüner Bernd
Published: August 2005

The concept of sustainable development implies the need for organizational learning in business corporations to find innovative solutions. In this context, the paper analyzes the requirements and options for environmental policy to induce sustainability‐related learning processes in corporations. It discusses the impacts of different policy instruments on these processes.

Initially, the particular challenges of organizational learning for sustainability are being sketched out. Drawing on organizational learning studies, a subsequent section of the paper addresses fundamental elements and drivers for organizational learning processes on different levels in business corporations. The particular nodes where public policy can influence corporate learning processes are the central focus of these considerations. On this basis, we examine existing policy instruments frequently used in environmental policy with regard to their potential to foster learning processes towards sustainability. Copyright © 2005 John Wiley & Sons, Ltd and ERP Environment.
Methyl Groups as Probes of Structure and Dynamics in NMR Studies of High‐Molecular‐Weight Proteins
Authors: Tugarinov Vitali , Kay Lewis E.
Published: August 2005

Solution NMR studies of biomolecules are typically limited by the molecules' molecular weight. Here we report strategies based on the use of highly deuterated, methyl‐protonated proteins that facilitate both structural and motional studies of molecules on the order of 100 kDa. Approaches and concepts are illustrated with applications to the enzyme malate synthase G, a monomeric 723‐residue protein.
Amplification and overexpression of prosaposin in prostate cancer
Authors: Koochekpour Shahriar , Zhuang Yu‐Jun , Beroukhim Rameen , Hsieh Chia‐Ling , Hofer Matthias D. , Zhau Haiyen E. , Hiraiwa Masao , Pattan Daniel Y. , Ware Joy L. , Luftig Ronald B. , Sandhoff Konrad , Sawyers Charles L. , Pienta Kenneth J. , Rubin Mark A. , Vessella Robert L. , Sellers William R. , Sartor Oliver
Published: August 2005

We identified prosaposin (PSAP) as a secreted protein expressed in androgen‐independent (AI) prostate cancer cells by cloning/sequencing, after probing a PC‐3 cDNA library expressed in the λTriplEx phagemid expression vector with a polyclonal rabbit antibody generated against pooled human seminal plasma. PSAP is a neurotrophic molecule; its deficiency or inactivation has proved to be lethal in man and mice, and in mice, it leads to abnormal development and atrophy of the prostate gland, despite normal testosterone levels. We used Southern hybridization, quantitative real‐time polymerase chain reaction, and/or single nucleotide polymorphism (SNP) array analysis, and we now report the genomic amplification of PSAP in the metastatic AI prostate cancer cell lines, PC‐3, DU‐145, MDA‐PCa 2b, M‐12, and NCI‐H660. In addition, by using SNP arrays and a set of 25 punch biopsy samples of human prostate cancer xenografts (LAPC3, LuCaP 23.1, 35, 49, 58, 73, 77, 81, 86.2, 92.1, 93, 96, 105, and 115), lymph nodes, and visceral‐organ metastases, we detected amplification of the PSAP locus (10q22.1) in LuCaP 58 and 96 xenografts and two lymph node metastases. In addition, AI metastatic prostate cancer cell lines C4‐2B and IA8‐ARCaP over‐expressed PSAP mRNA without evidence of genomic amplification. Taken together with prior data that demonstrated the growth‐, migration‐, and invasion‐promoting activities, the activation of multiple signal transduction pathways, and the antiapoptotic effect of PSAP (or one of its active domains, saposin C) in prostate cancer cells, our current observation of PSAP amplification or overexpression in prostate cancer suggests, for the first time, a role for this molecule in the process of carcinogenesis or cancer progression in the prostate. © 2005 Wiley‐Liss, Inc.
Direction‐dependent visual cortex activation during horizontal optokinetic stimulation (fMRI study)
Authors: Bense Sandra , Janusch Barbara , Schlindwein Peter , Bauermann Thomas , Vucurevic Goran , Brandt Thomas , Stoeter Peter , Dieterich Marianne
Published: August 2005

Looking at a moving pattern induces optokinetic nystagmus (OKN) and activates an assembly of cortical areas in the visual cortex, including lateral occipitotemporal (motion‐sensitive area MT/V5) and adjacent occipitoparietal areas as well as ocular motor areas such as the prefrontal cortex, frontal, supplementary, and parietal eye fields. The aim of this functional MRI (fMRI) study was to investigate (1) whether stimulus direction‐dependent effects can be found, especially in the cortical eye fields, and (2) whether there is a hemispheric dominance of ocular motor areas. In a group of 15 healthy subjects, OKN in rightward and leftward directions was visually elicited and statistically compared with the control condition (stationary target) and with each other. Direction‐dependent differences were not found in the cortical eye fields, but an asymmetry of activation occurred in paramedian visual cortex areas, and there were stronger activations in the hemisphere contralateral to the slow OKN phase (pursuit). This can be explained by a shift of the mean eye position of gaze (beating field) in the direction of the fast nystagmus phases of approximately 2.6 degrees, causing asymmetrical visual cortex stimulation. The absence of a significant difference in the activation pattern of the cortical eye fields supports the view that the processing of eye movements in both horizontal directions is mediated in the same cortical ocular motor areas. Furthermore, no hemispheric dominance for OKN processing was found in right‐handed volunteers. Hum Brain Mapp, 2005. © 2005 Wiley‐Liss, Inc.
Karakorum–Hindukush–western Himalaya: assessing high‐altitude water resources
Authors: Winiger M. , Gumpert M. , Yamout H.
Published: August 2005

The high mountains of Central and South Asia provide irrigation water for their adjacent lowlands. The Indus Irrigation Scheme depends on approximately 50% of its runoff originating from snowmelt and glacier melt from the eastern Hindukush, Karakorum and western Himalaya. The Atlas of Pakistan indicates that these mountains gain a total annual rainfall of between 200 and 500 mm, amounts that are generally derived from valley‐based stations and not representative for elevated zones. High‐altitude snowfall seems to be neglected and is obviously still rather unknown. Estimates derived from accumulation pits runoff above 4000 m range from 1000 mm to more than 3000 mm, depending on the site and time of investigation, as well as on the method applied.

To assess the vertical spatio‐temporal distribution of total annual precipitation, a combined approach is presented. This approach links in situ measurements of snow depth and water equivalent (10‐year time series derived from automatic weather stations at elevations between 1500 and 4700 m a.s.l.), the spatial distribution and period of snow coverage (remotely sensed data and digital elevation models), and the runoff characteristics of streams originating from snow or snow/ice‐covered watersheds (modified snowmelt runoff model, including intermediate snowfall and glacier runoff).

Based on conservative assumptions, the vertically changing seasonal ratio between liquid and solid precipitation is calculated. Using a combined snow cover and ablation model, total annual amounts of precipitation are derived for different altitudinal zones. Amounts of modelled and measured runoff complement the investigation. Horizontal gradients along the Indus–Gilgit–Hunza transect indicate the varying dominance of seasonal precipitation regimes (monsoonal, Mediterranean and continental disturbances) south of Nanga Parbat, between Nanga Parbat and Batura Wall (=West Karakorum rainfall regime: 1500–1800 mm year−1 at 5000 m) and areas north of Batura (=Central Asian rainfall regime: ∼600 mm year−1 at 5000 m). Copyright © 2005 John Wiley & Sons, Ltd.
The contribution of condensation to the water cycle under high‐mountain conditions
Authors: de Jong Carmen
Published: August 2005

Little is known about the interaction between condensation, precipitation and evaporation as an integral part of the water cycle under high‐mountain conditions. This paper focuses on methods of identification and measurement of condensation under natural conditions in high alpine valleys by example of the Dischma in eastern Switzerland. The role of different vegetation zones in transferring water from and to the atmosphere is investigated above the treeline (1900–2600 m a.s.l.). Field measurements of condensation and evaporation at 10 min intervals show that condensation plays a more significant role in the water cycle than previously assumed. Both diurnal and nocturnal condensation are compared at different altitudes on slope and valley locations during the exceptionally hot and dry mid‐summer of 1998. It is suggested that, in addition to standard hydrological components, water balance modelling in mountain zones should include more precise data on measured condensation. Copyright © 2005 John Wiley & Sons, Ltd.
Global analysis of host tissue gene expression in the invasive front of colorectal liver metastases
Authors: Bandapalli Obul Reddy , Geheeb Martina , Kobelt Dennis , Kuehnle Katrin , Elezkurtaj Sefer , Herrmann Jens , Gressner Axel M. , Weiskirchen Ralf , Beule Dieter , Blüthgen Nils , Herzel Hanspeter , Franke Claudia , Brand Karsten
Published: August 2005

Host cell reactions are a crucial determinant for tumor invasion. We analyzed on a genomewide scale gene expression differences between microdissected tissues taken from unaffected liver tissue of a human colorectal tumor (LS174) growing in the livers of nude mice and tissue from the host part of the invasive front. Due to the low degree of interspecies cross‐hybridization of 15% as determined on Affymetrix microarrays, our xenograft model allowed for the distinction of genes of murine versus human origin even if the respective tissues could not be isolated separately. Using the gene ontology (GO) classification, we were able to determine patterns of up‐ and downregulated genes in the liver part of the invasive front. We observed a pronounced overrepresentation, e.g., of the GO terms “extracellular matrix,” “cell communication,” “response to biotic stimulus,” “structural molecule activity” and “cell growth,” indicating a very pronounced host cell response to tumor invasion. On the single gene level, hepatic stellate cell (HSC) activation markers were overrepresented in the liver part of the invasion front. Immunohistochemistry and qPCR confirmed an activation of HSC as well as an increased number of HSC in the invasive front as compared to the noninvaded liver tissue. In summary, our data demonstrate the feasibility of an interspecies differential gene expression approach on a genomewide scale. © 2005 Wiley‐Liss, Inc.
Microvascular response of striated muscle to common arthroplasty‐alloys: A comparative in vivo study with CoCrMo, Ti‐6Al‐4V, and Ti‐6Al‐7Nb
Authors: Kraft Clayton N. , Burian Björn , Diedrich Oliver , Gessmann Jan , Wimmer Markus A. , Pennekamp Peter H.
Published: August 2005

The impairment of skeletal muscle microcirculation by a biomaterial may have profound consequences. Due to excellent physical and corrosion characteristics, CoCrMo‐, Ti‐6Al‐4V‐, and Ti‐6Al‐7Nb‐alloys are commonly used in orthopedic surgery. Yet concern has been raised with regard to the implications of inevitable corrosion product of these metals on the surrounding biologic environment, particularly in the case of CoCrMo. We, therefore, studied in vivo nutritive perfusion and leukocytic response of striated muscle to these alloys, thereby drawing conclusions on their inflammatory potential. In 28 hamsters, utilizing the dorsal skinfold chamber preparation and intravital microscopy, we could demonstrate that the implant material CoCrMo has a marked impact on local microvascular parameters. While the Ti‐alloys Ti‐6Al‐4V and Ti‐6Al‐7Nb induced only a transient and moderate inflammatory response, the implantation of a CoCrMo sample led to a distinct and persistent activation of leukocytes combined with disruption of the microvascular endothelial integrity and marked leukocyte extravasation. Animals with Ti‐alloys showed a clear tendency of recuperation, while in all but one CoCrMo‐treated animals, a breakdown of microcirculation prior to the scheduled end of the experiment was observed. Overall, the alloy Ti‐6Al‐7Nb was tolerated slightly better than Ti‐6Al‐4V under the chosen test conditions, though this discrepancy was not statistically significant. Conclusively, the commonly used biomaterials Ti‐6Al‐7Nb and Ti‐6Al‐4V induce a considerably lower inflammatory response in the skeletal muscle microvascular system, compared to a CoCrMo‐alloy. With a minimum of adverse host reaction, our results indicate that for this particular model Ti‐alloys are better tolerated than CoCrMo implant materials. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Fatigue of the cement/bone interface: The surface texture of bone and loosening
Authors: Arola D. , Stoffel K. A. , Yang D. T.
Published: August 2005

Loosening is recognized as one of the primary sources of total hip replacement (THR) failure. In this study the influence of the bone surface texture on loosening of the cement/bone interface was studied. Model cemented hip replacements were prepared and subjected to cyclic loads that induced pure shear fatigue of the cement/bone interface. The femoral canals were textured with the use of specific cutting tools to achieve a desired surface topography. Loosening of the implant with cyclic loading was characterized in terms of the initial migration (Region I), steady‐state loosening (Region II), and unstable loosening (Region III). Results from the experiments showed that the initial migration and rate of steady‐state loosening were dependent upon the bone surface topography. The apparent fatigue strength ranged from 0.8 to 5.1 MPa, and denotes the cyclic shear stress required for loosening of 1 mm within 10 million cycles. Regardless of the bone surface topography the ratio of apparent fatigue strength and ultimate shear strength of the interfaces was approximately 0.24. In general, the apparent fatigue strength increased proportional to the average surface roughness of the femoral canal and the corresponding volume available for cement interdigitation. In addition, there was a strong correlation between the normalized initial migration and the apparent fatigue strength (i.e., specimens with the highest initial migration exhibited the lowest fatigue strength). © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Effect of microstructure on the dry sliding friction behavior of CoCrMo alloys used in metal‐on‐metal hip implants
Authors: Varano R. , Bobyn J. D. , Medley J. B. , Yue S.
Published: August 2005

The microstructure and its effect on the friction behavior of a medical grade wrought cobalt–chromium–molybdenum (CoCrMo) alloy for surgical implants were studied in this work. In particular, the effects of compression and carbon (C) content on the above characteristics were analyzed. Increasing amounts of deformation resulted in a decrease in the number of annealing twins in the microstructures. In addition, there was an increase in the volume fraction of the hexagonal closed‐packed (HCP) phase due to a strain‐induced transformation (SIT) from the metastable face‐centered cubic (FCC) phase. The high C (HC) alloy had a lower volume fraction of this SIT phase. Friction studies conducted on these alloys revealed a higher coefficient of friction for the HC alloy and no significant effect of SIT on the friction characteristics. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Interannual rainfall variability over Western Tanzania
Authors: Mapande Amin T. , Reason C. J. C.
Published: August 2005

The evolution of the circulation anomalies associated with wet and dry austral summers (October–April) over western Tanzania (11.5–4.75°S, 29–37°E) are investigated. It is found that wet (dry) years are characterized by weaker (stronger) equatorial westerlies over the western Indian Ocean that lead to less (more) export of equatorial moisture away from East Africa. These anomalies arise from an anticyclonic (cyclonic) anomaly over the tropical western Indian Ocean during wet (dry) austral summers. In addition, enhanced (reduced) westerly moisture flux from the southern Congo basin occurs during the wet (dry) seasons. Large‐scale modulation of the Indian Ocean Walker cell is also evident in both cases, but particularly for the dry years.

During wet seasons, the rains typically begin earlier and end later, tend to be more evenly distributed and end more gradually. For dry seasons, the reverse tends to be the case. An inverse relationship between anomalies in Niño 3.4 sea‐surface temperature and those in dry‐spell frequency over the region was found. Copyright © 2005 Royal Meteorological Society.
Land degradation assessment by farmers in Bolivian mountain valleys
Authors: Kessler C. A. , Stroosnijder L.
Published: August 2005

A methodology is presented for assessing the seriousness and impact of land degradation, from a historical and a farmer perspective, in regions where data are not available. Farmers have been directly involved in the assessment of soil, productivity and vegetation cover loss over the past decades, both on cropland and on rangeland. The results for the Bolivian mountain valleys in north Chuquisaca show that the intensive use of small cropland fields has increased soil degradation and consequently led to less water and nutrient availability. Due to the subsequent productivity loss many cropland fields have been abandoned. Rangeland is also severely degraded as a result of the excessive removal of vegetation and subsequent soil loss. Farmers are very concerned, but consider the impact of changed rainfall and less available cropland beyond their control. Consequently, no serious initiatives are taken to solve the land degradation problem. This research adduces evidence of increased land degradation in the Bolivian mountain valleys over recent decades, and stresses the need for urgent (integrated) action with regard to soil and water conservation. Copyright © 2005 John Wiley & Sons, Ltd.
Synthesis and Properties of Syndiotactic Poly(propylene)/Carbon Nanofiber and Nanotube Composites Prepared by in situ Polymerization with Metallocene/MAO Catalysts
Authors: Wiemann Katharina , Kaminsky Walter , Gojny Florian H. , Schulte Karl
Published: August 2005

Summary: The preparation of syndiotactic poly(propylene) (sPP) nanocomposites with multi‐walled carbon nanotubes (MWNTs), carbon nanofibers (CNFs), and carbon black (CB) as fillers was accomplished by the in situ polymerization of propylene with a metallocene/methylalumoxane (MAO) catalyst. Different pre‐treatments were applied to achieve a homogeneous dispersion of the fillers in the matrix. The resulting nanocomposites were investigated with respect to their properties, which were then compared to those of the pure polymer and among each other. The thermal stability of the nanocomposites was slightly enhanced compared to the pure polymer. In addition, the yield strength of the nanocomposites could be slightly raised in comparison to the neat sPP. The most significant influence of the nanofillers was detected on the crystallization behavior. The crystallization temperature was increased with rising filler content in all cases. Moreover, the half‐time of crystallization was significantly reduced in the nanocomposites. The rate constant of crystallization was also greatly enhanced for all nanocomposites as compared to the neat sPP. The nanofillers acted, therefore, as nucleating agents. This effect was most pronounced in the case of MWNTs as fillers.

Influence of the type of filler on the degradation temperature (temperature of maximum weight loss).

magnified image

Influence of the type of filler on the degradation temperature (temperature of maximum weight loss).
Fabrication of CdS Nanorods in PVP Fiber Matrices by Electrospinning
Authors: Lu Xiaofeng , Zhao Yiyang , Wang Ce , Wei Yen
Published: August 2005

Summary: A controlled fabrication of rod‐like nanostructures of cadmium sulfide (CdS) incorporated into polymer fiber matrices has been developed by an electrospinning method. Here, poly(vinyl pyrrolidone) (PVP) was used as a polymer capping reagent, utilizing the interactions of cadmium ions with the carbonyl groups in the PVP molecules. The formation of CdS nanorods inside the PVP was carried out via the reaction of Cd2+ with H2S. SEM images showed that the electrospun films of PVP/CdS are composed of fibers with a diameter between 100 and 900 nm. TEM proved that most of the CdS nanorods are incorporated in the PVP fibrous film. The diameter of the rod is about 50 nm and the length is from 100 to 300 nm.

TEM image of the CdS nanorods formed in the PVP fibrous film.

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TEM image of the CdS nanorods formed in the PVP fibrous film.
Levetiracetam in patients with cortical myoclonus: A clinical and electrophysiological study
Authors: Striano Pasquale , Manganelli Fiore , Boccella Patrizia , Perretti Anna , Striano Salvatore
Published: August 2005

Levetiracetam is a new antiepileptic agent that exerts antimyoclonic effects. We conducted an open‐label trial to evaluate the effect of levetiracetam in chronic cortical myoclonus of diverse etiologies and to determine whether levetiracetam affects electrophysiological findings. Sixteen patients, aged between 19 and 72 years, with refractory, chronic, cortical myoclonus were recruited. We assessed myoclonus severity with the Unified Myoclonus Rating Scale (UMRS). The electrophysiological study comprised jerk‐locked averaging, somatosensory evoked potentials (SEPs), and long loop reflex I. Levetiracetam was administered add‐on at a starting dose of 500 mg twice per day up to the target dose of 50 mg/kg/day. Patients were reevaluated clinically and electrophysiologically 2 weeks after the titration phase. Fourteen patients completed the trial. Posttreatment UMRS scores showed an improvement of myoclonus in all cases. Pretreatment, 9 patients had “giant” SEPs. Posttreatment, the amplitude of these SEPs was reduced by more than 50% in 3 of 9 patients, and the mean N20‐P25 amplitude was reduced significantly. Pre‐ and posttreatment SEP amplitude was not related to myoclonus severity or duration. Levetiracetam is a promising and a relatively easy‐to‐test antimyoclonic agent, which has the potential to improve significantly the patient's disability; however, its long‐term efficacy should be verified in larger controlled studies. © 2005 Movement Disorder Society
Parkinson's disease mortality among male anesthesiologists and internists
Authors: Peretz Chava , Alexander Bruce H. , Nagahama Sonia I. , Domino Karen B. , Checkoway Harvey
Published: August 2005

Clusters of Parkinson's disease (PD) among healthcare professionals have been interpreted as evidence of an infectious etiology. Anesthetic gases have also been associated with parkinsonism symptoms and PD among patients undergoing general anesthesia. We investigated PD mortality among large cohorts of male U.S. anesthesiologists (n = 33,040) and internal medicine physicians (n = 33,044). PD mortality for any mention on a death certificate was lower than rates in U.S. men during 1979–1995 for both groups, although anesthesiologists had a significantly elevated risk for PD as underlying cause of death for 10‐year follow‐up. Direct comparisons of mortality between the two cohorts indicated excess PD mortality in anesthesiologists for >10‐year follow‐up for any mention and for underlying cause of death. These findings lend some support to the hypothesis that infectious agents or anesthetic gases may be associated etiologically with PD. © 2005 Movement Disorder Society
The electronic spectra of 2‐(2′‐hydroxybenzoyl)pyrrole and 2‐(2′‐methoxybenzoyl)pyrrole: a theoretical study
Authors: Ghigo Giovanni , Ciofalo Maurizio , Gagliardi Laura , La Manna Gianfranco , Cramer Christopher J.
Published: August 2005

The gas‐phase electronic spectra of 2‐(2′‐hydroxybenzoyl)pyrrole and 2‐(2′‐methoxybenzoyl)pyrrole have been determined using multiconfigurational perturbation theory (CASPT2). Solvatochromic spectral shifts for these molecules have been measured in cyclohexane and methanol and the electrostatic components of these shifts have been estimated using the vertical electrostatic model (VEM 4.2) developed for the configuration interaction with single excitations model implemented with the intermediate neglect of differential overlap Hamiltonian (CIS/INDO/S2). Comparison between theory and experiment and an interpretation of the main spectral differences between the two substituted pyrroles and their solvation are presented. Copyright © 2005 John Wiley & Sons, Ltd.
Calorimetric determination of hydrogen‐bonding enthalpy for neat aliphatic alcohols
Authors: Solomonov Boris N. , Novikov Vladimir B. , Varfolomeev Mikhail A. , Klimovitskii Alexander E.
Published: August 2005

Hydrogen bonding in pure aliphatic alcohols is investigated using a novel calorimetric approach. Average enthalpies of hydrogen bonding were determined for methanol, ethanol, propan‐1‐ol, propan‐2‐ol, butan‐1‐ol, hexan‐1‐ol and octan‐1‐ol. For all the studied alcohols except methanol the average hydrogen‐bonding enthalpies fall in the range from −16.9 to −17.7 kJ mol−1. A slightly smaller value of −15.1 kJ mol−1 was observed for methanol. From the enthalpies of the specific interactions of the alcohols and chloroform (as proton donors) formed with the alcohols and diethyl ether (as proton acceptors), the dimerization enthalpies were determined for the investigated alcohols: −8.6 ± 0.7 kJ mol−1. The specific interaction and dimerization enthalpies obtained are concurrent with the Badger–Bauer rule and the hydrogen‐bond cooperativity effects. The calorimetric data obtained are supported by literature Fourier transform infrared data on dimer and multimer formation for ethanol and octan‐1‐ol in tetrachloromethane solution. Copyright © 2005 John Wiley & Sons, Ltd.
Prediction of interface residues in protein–protein complexes by a consensus neural network method: Test against NMR data
Authors: Chen Huiling , Zhou Huan‐Xiang
Published: August 2005

The number of structures of protein–protein complexes deposited to the Protein Data Bank is growing rapidly. These structures embed important information for predicting structures of new protein complexes. This motivated us to develop the PPISP method for predicting interface residues in protein–protein complexes. In PPISP, sequence profiles and solvent accessibility of spatially neighboring surface residues were used as input to a neural network. The network was trained on native interface residues collected from the Protein Data Bank. The prediction accuracy at the time was 70% with 47% coverage of native interface residues. Now we have extensively improved PPISP. The training set now consisted of 1156 nonhomologous protein chains. Test on a set of 100 nonhomologous protein chains showed that the prediction accuracy is now increased to 80% with 51% coverage. To solve the problem of over‐prediction and under‐prediction associated with individual neural network models, we developed a consensus method that combines predictions from multiple models with different levels of accuracy and coverage. Applied on a benchmark set of 68 proteins for protein–protein docking, the consensus approach outperformed the best individual models by 3–8 percentage points in accuracy. To demonstrate the predictive power of cons‐PPISP, eight complex‐forming proteins with interfaces characterized by NMR were tested. These proteins are nonhomologous to the training set and have a total of 144 interface residues identified by chemical shift perturbation. cons‐PPISP predicted 174 interface residues with 69% accuracy and 47% coverage and promises to complement experimental techniques in characterizing protein–protein interfaces. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Reversible ventricular dysfunction takotsubo cardiomyopathy
Authors: Akashi Yoshihiro J. , Musha Haruki , Kida Keisuke , Itoh Kae , Inoue Koji , Kawasaki Kensuke , Hashimoto Nobuyuki , Miyake Fumihiko
Published: August 2005

Background:

Recently, many cardiologists have recognized the existence of a rapidly reversible form of heart failure of unknown origin characterized by a takotsubo‐shaped, dyskinetic left ventricle on left ventriculography.

Aim:

To determine the detailed clinical features of takotsubo cardiomyopathy.

Methods:

Thirteen elderly patients (11 women and 2 men with a mean age of 75.3 years) who had normal coronary arteries and takotsubo‐like left ventricular dysfunction were prospectively enrolled in this study.

Results:

Cardiac enzymes did not increase significantly, but the mean plasma norepinephrine level was very high on admission (0.98 μg/l). Coronary angiography revealed normal coronary arteries in all patients, but left ventriculography showed apical akinesis combined with basal hyperkinesis, i.e., a takotsubo (Japanese octopus fishing pot)‐shaped ventricle. Left ventricular wall motion normalized within a mean of 16.9 hospital days in 12 patients, but 1 patient died of acute renal failure on hospital day 7. Cardiac events did not recur during a follow‐up period of 0.5 to 5 years.

Conclusion:

Takotsubo cardiomyopathy seems to be a new type of acute heart failure, which generally has a good prognosis and does not recur. Myocardial damage by catecholamine overload, adrenoceptor hypersensitivity, and changes of catecholamine dynamics due to stress may cause this condition.
Synechocystis ferredoxin/ferredoxin‐NADP+‐reductase/NADP+ complex: Structural model obtained by NMR‐restrained docking
Authors: Palma P. Nuno , Lagoutte Bernard , Krippahl Ludwig , Moura José J.G. , Guerlesquin Françoise
Published: August 2005

Ferredoxin (Fd) and ferredoxin‐NADP+‐reductase (FNR) are two terminal physiological partners of the photosynthetic electron transport chain. Based on a nuclear magnetic resonance (NMR)‐restrained‐docking approach, two alternative structural models of the Fd–FNR complex in the presence of NADP+ are proposed. The protein docking simulations were performed with the software BiGGER. NMR titration revealed a 1:1 stoichiometry for the complex and allowed the mapping of the interacting residues at the surface of Fd. The NMR chemical shifts were encoded into distance constraints and used with theoretically calculated electronic coupling between the redox cofactors to propose experimentally validated docked complexes.
Cell‐cycle regulators are involved in transient cerebral ischemia induced neuronal apoptosis in female rats
Authors: Wen Yi , Yang Shaohua , Liu Ran , Simpkins James W.
Published: August 2005

Recent evidence indicates that cell‐cycle regulating proteins are involved in apoptotic process in post‐mitotic neurons. In this study, we examined cell‐cycle regulators for G1/S cell‐cycle progression after a transient focal cerebral ischemia induced by middle cerebral artery (MCA) occlusion. In the cerebral frontoparietal cortex, we observed a marked induction of Cyclin D1 (a coactivator of Cdks), and proliferating cell nuclear antigen (PCNA), together with upregulated Cdk kinase activities. This process is accompanied with multiple phosphorylation of retinoblastoma (Rb) protein at Cdk phosphorylation sites in neurons from the ischemic cortex. We further examined DNA synthesis by the incorporation of BrdU, a nucleotide analog that incorporates into newly synthesized DNA. Within 24‐h of reperfusion after 60‐min occlusion, substantial BrdU‐positive neurons were observed in the ischemic cortex. Inhibition of Cdk4 activity during this ischemia/reperfusion is highly neuroprotective. These results suggest that ischemia/reperfusion cerebral damage induces signalings at the G1/S cell‐cycle transition, and may constitute a critical step in the neuronal apoptotic pathway in ischemia/reperfusion induced neuronal damage.