bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maternal experience inhibits the production of immature neurons in the hippocampus during the postpartum period through elevations in adrenal steroids
Authors: Leuner Benedetta , Mirescu Christian , Noiman Liron , Gould Elizabeth 
Published: March 2007

AbstractMotherhood is accompanied by alterations in numerous nonreproductive behaviors, including learning and memory, as well as anxiety and stress regulation. These functions have been linked to adult neurogenesis in the hippocampus, but the effect of maternal experience on this brain region has not been completely explored. To determine whether the production of new hippocampal granule cells is altered during the postpartum period, we examined the number of proliferating cells and their progeny in the dentate gyrus of primiparous female rats at various time points during the postpartum period while they were caring for their offspring, as well as after weaning. Additionally, we investigated whether cell proliferation in the postpartum female is affected by the presence of offspring and nursing‐induced increases in glucocorticoids. Analysis of the number of BrdU‐labeled cells revealed that cell proliferation in the dentate gyrus was suppressed in lactating postpartum females until the time of weaning. This effect was temporary; a difference was detectable at 1 week after BrdU‐labeling, when the majority of cells expressed a marker of immature and mature granule neurons (TuJ1) but not at 2 weeks, when most cells expressed a marker of mature neurons (NeuN). The decrease in cell proliferation was dependent on elevated basal glucocorticoid levels associated with lactation; removal of nursing pups reduced basal corticosterone levels and prevented the decrease in the number of BrdU‐labeled cells. Moreover, preventing increased basal corticosterone levels by means of adrenalectomy and low‐dose corticosterone replacement eliminated the reduction in cell proliferation. These findings indicate that offspring interactions inhibit adult neurogenesis through changes in adrenal steroids, and further suggest a potential mechanism for alterations in hippocampal function during the postpartum period. © 2007 Wiley‐Liss, Inc.
Ameliorative effects of a neuroprotective agent, T‐817MA, on place learning deficits induced by continuous infusion of amyloid‐β peptide (1–40) in rats
Authors: Nguyen Phuong Thi Hong , Kimura Tatsuo , Ho Son Anh , Tran Anh Hai , Ono Taketoshi , Nishijo Hisao 
Published: March 2007

AbstractAlzheimer's disease (AD) is a neurodegenerative disease characterized by cognitive decline due to neuronal loss and neural network dysfunction. It has been postulated that progressive neuronal loss in AD is consequence of the neurotoxic properties of the amyloid‐β peptide (Aβ). In the present study, we investigated the effect of T‐817MA (1‐{3‐[2‐(1‐benzothiophen‐5‐yl)ethoxy] propyl}‐3‐azetidinol maleate), a newly synthesized neurotrophic compound, on place learning deficits in rats with hippocampal damages. To induce granule cell loss in the dentate gyrus (DG) of the hippocampus, Aβ (1–40) was continuously infused (300 pmol/day) into the cerebral ventricle using a mini‐osmotic pump for 5 weeks. Three weeks after the Aβ infusion, the rats were tested in a place learning task, which required them to alternatively visit two diametrically opposed areas in an open field to obtain intracranial self‐stimulation reward. The results indicated that the Aβ‐infused rats without treatment of T‐817MA displayed learning impairment in the task; their performance level was significantly inferior to that of the vehicle rats. Treatment of T‐817MA (8.4 mg/kg/day, p.o.) significantly improved the task performance of the Aβ‐infused rats. Furthermore, T‐817MA prevented granule cell loss due to Aβ‐infusion, which was correlated to task performance of the rats. However, other cognitive enhancer, an acetylcholinesterase inhibitor, had no such effects. The results demonstrated that T‐817MA ameliorated learning deficits induced by Aβ infusion, which might be attributed to neuroprotection in the hippocampus. © 2007 Wiley‐Liss, Inc.
Signs of proinflammatory/genotoxic switch (adipogenotoxicosis) in mammary fat of breast cancer patients: Role of menopausal status, estrogens and hyperglycemia
Authors: Berstein Lev M. , Kovalevskij Anatolij Y. , Poroshina Tatjana E. , Kotov Alexander V. , Kovalenko Irina G. , Tsyrlina Evgenia V. , Leenman Elena E. , Revskoy Sergey Y. , Semiglazov Vladimir F. , Pozharisski Kazimir M. 
Published: March 2007

AbstractThe abundance of fat tissue surrounding normal and malignant epithelial mammary cells raises the questions whether such “adipose milieu” is important in the local proinflammatory/genotoxic shift, which apparently promotes tumor development and worsens prognosis, and what conditions stimulate this shift, or “adipogenotoxicosis.” We studied 95 mammary fat samples from 70 postmenopausal and 25 premenopausal breast cancer (BC) patients at a distance of 1.5–2.0 cm from tumors. The levels of leptin, adiponectin, TNFα and IL‐6 release after 4‐hr incubation of the samples were evaluated with ELISA, nitric oxide (NO) production by Griess reaction and lipid peroxidation by determination of thiobarbiturate‐reactive products (TBRP). Infiltration of fat with macrophages (CD68‐positive cells) and expression of cytochrome P450 1B1/estrogen 4‐hydroxylase (CYP1B1) were detected by immunohistochemistry. Aromatase (CYP19) activity in mammary fat was measured by 3H2O release from 3H‐1β‐androstenedione. In the postmenopausal BC patients, NO and TNFα production by adipose tissue explants increased independent of BMI and in parallel with decreasing leptin and, especially, adiponectin release. In the premenopausal patients, higher CYP1B1 expression and TBRP level were found in mammary fat, while higher aromatase activity was combined with higher CYP1B1 expression as well as NO and IL‐6 production. In the postmenopausal group, impaired glucose tolerance was associated with higher IL‐6 release production by fat and with higher IL‐6/adiponectin ratio. Thus, signs of adipogenotoxicosis in mammary fat can be found in both pre‐ and postmenopausal BC patients. This condition is likely being maintained through estrogen‐ and glucose‐related factors and mechanisms presumably associated with less favorable types of hormonal carcinogenesis. © 2007 Wiley‐Liss, Inc.
Benefit of sentinel lymphadenectomy for patients with nonulcerated cutaneous melanomas in the Breslow range between 0.76 and 1 mm: A follow‐up study of 148 patients
Authors: Starz Hans , Balda Bernd‐Ruediger 
Published: March 2007

AbstractSentinel lymphadenectomy (SLNE) is now internationally accepted for the primary treatment of melanomas thicker than 1 mm. But it is still controversial whether also patients with nonulcerated melanomas in the Breslow range between 0.76 and 1 mm should be included. At the authors' department, 87 of such patients (Group A) underwent SLNE in combination with wide local excision (WLE) of their primary melanomas in the years 1995 to 2001. SLN micrometastases were found in 10 of these patients (11.5%). Radical completion lymph node dissections (CLND) were added in 4 of the 10 patients without revealing any further nodal metastases. All the 87 Group A patients remained free from recurrent disease at a median follow‐up time of 74 months. The control Group B from the same department encompassed 61 consecutive stage Ia patients with melanomas in the identical Breslow range, who had undergone only WLE of their primaries without SLNE in the years 1987 to 1993 (median follow‐up time 115 months). Five of these 61 patients (8.2%) developed melanoma metastases within 12 to 68 (median 19) months of follow‐up, 3 of them initially in regional lymph nodes. Four of the 5 individuals died because of the final distant dissemination of the melanoma. Kaplan–Meier comparisons between Groups A and B with log‐rank testing showed a significantly worse outcome of Group B with respect to recurrence‐free survival (p = 0.01), regional nodal progression (p = 0.041), distant metastasis (p = 0.023) and melanoma‐related mortality (p = 0.03). The overall survival was not significantly different, because expiries not related to melanoma predominated in both groups. Our data suggest that SLNE seems to nearly completely eliminate the risk of melanoma recurrences in patients with melanomas between 0.76 and 1 mm thick. © 2007 Wiley‐Liss, Inc.
Tribological investigation of novel HDPE‐HAp‐Al2O3 hybrid biocomposites against steel under dry and simulated body fluid condition
Authors: Nath Shekhar , Bodhak Subhadip , Basu Bikramjit 
Published: March 2007

AbstractAmong various biocompatible polymers, polyethylene based materials have received wider attention because of its excellent stability in body fluid, inertness, and easy formability. Attempts have been made to improve their physical properties (modulus/strength) to enable them to be used as load bearing hard tissue replacement applications. Among such attempts, high density polyethylene (HDPE)‐hydroxyapatite (HAp) composite (HAPEXTM), has already been developed for total hip replacement (THR) acetabular cup and low load bearing bone tissue replacement. In the present work, alumina has been added as a partial replacement of HAp phase to improve the mechanical and tribological properties of the HAPEX composite. In an attempt to assess the suitability of the developed composite in THR application, the tribological properties against steel counterbody under both in air and simulated body fluid (SBF), have been investigated and efforts have been made to understand the wear mechanisms. The fretting wear study indicates the possibility of achieving extremely low COF (Coefficient of Friction ∼0.09) as well as higher wear resistance (order of 10−6 mm3/N m) with the newly developed composites in SBF. A low wear depth of ∼4.6−5.3 μm is recorded, irrespective of fretting environment. The implication of the work is that optimal and combined addition of bioactive and bioinert ceramic filler to HDPE can provide a good opportunity to obtain hybrid biocomposites with better combination of physical properties (modulus, hardness) as well as low friction and high wear resistance. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Semiovals contained in the union of three concurrent lines
Authors: Blokhuis Aart , Kiss Győrgy , Kovács István , Malnič Aleksander , Marušič Dragan , Ruff János 
Published: March 2007

AbstractSemiovals which are contained in the union of three concurrent lines are studied. The notion of a strong semioval is introduced, and a complete classification of these objects in PG(2,p) and PG(2,p2), p an odd prime, is given. © 2007 Wiley Periodicals, Inc. J Combin Designs 15: 491–501, 2007
A new approach for numerical simulation of quantum transport in double‐gate SOI
Authors: Abdolkader Tarek M. 
Published: March 2007

AbstractNumerical simulation of nanoscale double‐gate SOI (Silicon‐on‐Insulator) greatly depends on the accurate representation of quantum mechanical effects. These effects include, mainly, the quantum confinement of carriers by gate‐oxides in the direction normal to the interfaces, and the quantum transport of carriers along the channel. In a previous work, the use of transfer matrix method (TMM) was proposed for the simulation of the first effect. In this work, TMM is proposed to be used for the solution of Schrodinger equation with open boundary conditions to simulate the second quantum‐mechanical effect. Transport properties such as transmission probability, carrier concentration, and I–V characteristics resulting from quantum transport simulation using TMM are compared with that using the traditional tight‐binding model (TBM). Comparison showed that, when the same mesh size is used in both methods, TMM gives more accurate results than TBM. Copyright © 2007 John Wiley & Sons, Ltd.
Glial fibrillary acidic protein‐expressing cells in the neurogenic regions in normal and injured adult brains
Authors: Zhu Hong , Dahlström Annica 
Published: March 2007

AbstractIn the adult brain, neurogenic stem cells are prevalent in the subventricular zone (SVZ) of the lateral ventricle wall and the subgranular zone (SGZ) in the dentate gyrus. Cells that have structural and molecular characteristics of astrocytes function as neurogenic stem cells in these regions, in which these cells also participate in the creation of the microenvironment that stimulates neurogenesis. In the present paper, we review the phenotypic properties, subpopulations, and proliferation of glial fibrillary acidic protein (GFAP)‐expressing cells in these two neurogenic regions and their responses to different brain injuries. Cells fulfilling the criteria for astrocytes, i.e., expressing GFAP, in the SVZ and SGZ respond differently to brain injuries or neurogenic stimuli. The importance of guidance by astrocytes of newly formed neuronal cells is emphasized. The assessment of GFAP‐expressing cells in the neurogenic regions is of great importance for understanding the mechanism underlying the response of neural stem cells to brain injury. © 2007 Wiley‐Liss, Inc.
Expression pattern of stop lacZ reporter gene in adult and developing mouse brain
Authors: Couégnas Alice , Schweitzer Annie , Andrieux Annie , Ghandour M. Said , Boehm Nelly 
Published: March 2007

AbstractStable tubulin‐only polypeptide (STOP) proteins are microtubule‐associated proteins responsible for microtubule stabilization in neurons. STOP null mice show apparently normal cerebral anatomy but display synaptic defects associated with neuroleptic‐sensitive behavioral disorders. STOP null mice have therefore been proposed as an animal model for the study of schizophrenia. In the present study, the expression pattern of STOP gene in developing and adult brain has been examined by using lacZ gene inserted in the STOP locus, as a reporter gene. β‐Galactosidase (β‐gal) immunostaining was confined to neuronal cells and projections. Strong labeling was observed in the whole olfactory system, cortical layer VII, hippocampus, hypothalamus, cerebellum, habenula, fasciculus retroflexus, and interpeduncular nucleus in adults. Additionally, ventral thalamic nucleus, clusters of positive cells in striatum, and Cajal‐Retzius cells of cortical layer I were labeled in young mice. The strong expression of STOP lacZ reporter gene observed in brain is confined to areas that may be involved in the schizophrenia‐related symptoms observed in STOP‐deficient mice. © 2007 Wiley‐Liss, Inc.
Ergosterol and mycotoxins in grain dusts from fourteen Belgian cereal storages: A preliminary screening survey
Authors: Tangni Emmanuel K , Pussemier Luc 
Published: March 2007

AbstractGrain dusts from farms and storage companies are generally used in animal feeding. They can give rise to airborne dust in the environment of workers or accidentally contaminate the following stored grains. Because dusts are potential mycotoxin‐rich materials, this preliminary screening survey was undertaken on citreoviridin, citrinin, cyclopiazonic acid, deoxynivalenol, gliotoxin, helvolic acid, mycophenolic acid, nivalenol, ochratoxin A, patulin, penicillic acid, secalonic acid D, sterigmatocystin, zearalenol and zearalenone. Furthermore, ergosterol was determined as a fungal growth marker. Fourteen grain dusts collected from farms and storage companies in Belgium were assayed and toxins co‐occurred at uneven distributions with wide ranges of concentrations. Median concentrations exceeded 1 µg g−1 for penicillic acid, gliotoxin, deoxynivalenol, helvolic acid, mycophenolic acid, patulin, sterigmatocystin and zearalenol. Using the median values, an assessment of worker exposure indicated that mycotoxin uptake through dust inhalation may simultaneously contribute to 0.5, 0.5, 0.7 and 0.1% of the respective tolerable daily intake of ochratoxin A, patulin, deoxynivalenol and zearalenone. In spite of these low values, the question of multi‐contamination of grain dusts and, consequently, exposure to several mycotoxins should not be underestimated. Moreover, inhalation of contaminated airborne aerosols can represent an additional route of exposure which has not been exhaustively investigated so far. Copyright © 2007 Society of Chemical Industry
Chemical composition and antimicrobial activity of Anzer tea essential oil
Authors: Şekeroǧlu Nazım , Deveci Metin , Buruk C Kurtuluş , Gürbüz Bilal , İpek Arif 
Published: March 2007

AbstractAnzer tea (Thymus praecox, subsp. caucasicus var. caucasicus) naturally grows in the eastern Black Sea region of Turkey. Anzer tea, a creeping plant with crimson‐pink flowers, is important for honey production in the region. In the present study, content, composition and antimicrobial properties of Anzer tea's essential oil were investigated. Essential oil content of dried aerial plant parts varied between 1.53% and 2.05%. Essential oil composition was studied by means of gas chromatography–mass spectrometry, and 26 components were identified. The major components were thymol (47.45%), γ‐terpinene (8.73%), p‐cymene (8.30%), terpinyl acetate (4.88%) and carvacrol (4.66%). Essential oil was also screened for its antibacterial activity. In a screen for antibacterial activity, Anzer tea essential oil had significant activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Candida albicans. Copyright © 2007 Society of Chemical Industry
Das asymptotische verhalten der greenschen funktion N‐irregulaärer eigenwertprobleme mit zerfallenden randbedingungen
Authors: Wolter M. , Neunzert H. 
Published: March 2007

AbstractWe prove asymptotic estimates for the Green's function of N‐irregular eigenvalue problems My = λNγ with splitting boundary conditions.In contrast to the N‐regular case the Green's function G(x,ζ,λ) grows exponentially for |λ| → ∞ if x > ζ.These estimates are fundamental for the expansion of functions into a series of eigenfunctions of N‐irregular eigenvalue problems. In a subsequent paper it will be shown that this irregular behavior of G(x,ζ,λ) implies that only a very small class of functions can be expanded into a series of eigenfunctions of such problems.
On turning points
Authors: Stork W. , Robinowitz P. 
Published: March 2007

AbstractFor a family {T + Nλ: λ ϵ [a, b]} of semilinear operators T + Nλ in L2(Ω) the solution set {(λ, uλ) ϵ J × D(T): Tuλ + Nλuλ = h} is investigated with respect to turning points. By Ljapunov‐Schmidt‐reduction and calculation of the derivatives of the bifurcation equation a class of turning points is characterized by properties of these derivatives.
Stabilität bei Systemen mit quasizyklischen Koordinaten
Authors: Otterbein S. , Hagedorn P. 
Published: March 2007

AbstractQuasicyclic or quasiignorable coordinates occur in mechanical systems with equations of motion of the Lagrangian type and can be interpreted as a generalisation of the well known cyclic or ignorable coordinates. In this paper parts of the theory of cyclic coordinates are extended to quasicyclic coordinates. Especially we present sufficient conditions for the existence of the reduced system and generalize the Routh‐Salvadori theorem about the stability of stationary motions.
Évolution quasi‐statique des milieux visco‐plastiques de maxwell‐norton
Authors: Djaoua M. , Suquet P. , Nedelec J. C. 
Published: March 2007

AbstractIn this paper, we deal with the existence and unicity of a solution of the Maxwell‐Norton quasi‐static problem. Some fundamental results concerning the functional spaces are first recalled. Then, by an implicit scheme, we obtain a discretized problem which is well‐posed. By monotonicity techniques, we finally prove the convergence of the discrete solutions to the solution of the initial problem.
A generalized jacobi theta function
Authors: Lehnigk S. H. , Roach G. F. 
Published: March 2007

AbstractThe delta function initial condition solution v*(x,t;y) at x = y ≥ 0 of the generalized Feller equation is used to define a generalized Jacobi Theta function for a sufficiently rapidly increasing and unbounded positive sequence {yy}. It is shown that Θ(x,t) is analytic in each variable in certain regions of the complex x and t planes and that it is a solution of the generalized Feller equation. For those parameters for which this equation reduces to the heat equation, Θ(x,t) reduces to the third Jacobi Theta function.
Forward speed motions of a submerged body. The cauchy problem
Authors: Hamdache K. , Nedelec J. C. 
Published: March 2007

AbstractWe consider the linearized problem for the ideal fluid flow induced by the horizontal motion of a fully immersed body. The system of equations is made up of an elliptic problem (P) and an initialvalue problem (R) which are coupled by a pseudo‐differential operator T.We define a regularized Cauchy problem (Rϵ) using the Yosida approximation of T; we give energy and wave resistance estimates and finally we obtain existence uniqueness and regularity of the weak solution of (R) by taking the limit when ϵ goes to zero.
Numerical Computation of Waves at High Frequencies by an Iterated WKB‐Method
Authors: Alber H. D. , Leis R. 
Published: March 2007

AbstractAn integral operator is defined, which allows to solve the equation

equation image

by Neumann series for sufficiently large k > 0. The kernel is constructed by a modification of the WKB‐method. This kernel is so simple that the operator can be used effectively for numerical calculations. Numerical results are discussed.
On the Vlasov‐Fokker‐Planck equation
Authors: Neunzert H. , Pulvirenti M. , Triolo L. 
Published: March 2007

AbstractWe study a modification of the Vlasov‐Poisson equation, obtained by adding a diffusion term with respect to velocity. It describes, from a physical point of view, a plasma in thermal equilibrium, in a mean field limit situation. We find that the already known results concerning existence and uniqueness of the solutions for the ordinary Vlasov equation (constructive results and counterexamples) translate to our case.
On the statistical solutions of the two‐dimensional, periodic Euler equation
Authors: Caprino S. , De Gregorio S. , Neunzert H. 
Published: March 2007

AbstractWe investigate the problem to define statistical solutions for the two‐dimensional, periodic Euler Equation and prove a theorem of global existence and uniqueness for a regularized version. Moreover, we deduce the existence of the Euler flow in a weak form.
On spline collocation methods for boundary integral equations in the plane
Authors: Schmidt G. , Wendland W. 
Published: March 2007

AbstractNowadays boundary elemen; methods belong to the most popular numerical methods for solving elliptic boundary value problems. They consist in the reduction of the problem to equivalent integral equations (or certain generalizations) on the boundary Γ of the given domain and the approximate solution of these boundary equations. For the numerical treatment the boundary surface is decomposed into a finite number of segments and the unknown functions are approximated by corresponding finite elements and usually determined by collocation and Galerkin procedures. One finds the least difficulties in the theoretical foundation of the convergence of Galerkin methods for certain classes of equations, whereas the convergence of collocation methods, which are mostly used in numerical computations, has yet been proved only for special equations and methods.In the present paper we analyse spline collocation methods on uniform meshes with variable collocation points for one‐dimensional pseudodifferential equations on a closed curve with convolutional principal parts, which encompass many classes of boundary integral equations in the plane. We give necessary and sufficient conditions for convergence and prove asymptotic error estimates. In particular we generalize some results on nodal and midpoint collocation obtained in [2], [7] and [8].The paper is organized as follows. In Section 1 we formulate the problems and the results, Section 2 deals with spline interpolation in periodic Sobolev spaces, and in Section 3 we prove the convergence theorems for the considered collocation methods.