bluuebunny/crossref_metadata_2025_split huggingface dataset:
Factors influencing mutation at the hprt locus in T‐lymphocytes: Studies in normal women and women with benign and malignant breast masses
Authors: Branda Richard F. , O'Neill J. Patrick , Jacobson‐Kram David , Albertini Richard J. 
Published: September 2008

AbstractA prospective, longitudinal study was performed to test the hypothesis that environmental factors (e.g., diet or cigarette smoking) modulate genetic damage caused by treatment for breast cancer and render these women more susceptible to developing second malignancies. A total of 107 women (49 with breast cancer, 52 with benign breast masses, and 6 normal women) were enrolled. This report describes initial studies at the time of enrollment and disease presentation. Mutant frequency at the hprt locus and cloning efficiency of peripheral blood lymphocytes did not differ significantly among the 3 groups. Mutant frequency increased with age, with a history of cigarette smoking, and with the number of years that current smokers used cigarettes. There was no correlation in women with benign masses between mutant frequency and the incidence of chromosome aberrations (28 women) or sister chromatid exchanges (23 women). A maternal history of breast cancer did not influence mutant frequency. There was no significant relationship between dietary intake of vitamins A, B12, C and E, folacin, selenium, calcium, caffeine, or multivitamin pills, and mutant frequency. Serum folate levels in the deficient range were associated (P = 0.02) with elevated mutant frequencies, whereas SCE rates inversely correlated with serum vitamin B12 levels. These results confirm the importance of age and, less so, cigarette smoking as factors that influence mutant frequency and suggest that a micronutrient, folic acid, may modify genetic damage at the hprt locus. To the extent that somatic mutation contributes to carcinogenesis, these environmental factors may enhance the risk of developing malignant transformation.
Isolation by fluorescence‐activated cell sorting of cells of a human lymphoblastoid cell strain containing mutations in the lambda immunoglobulin gene
Authors: McFarland Richard D. , Vincent Jack L. , Smith Gary J. 
Published: September 2008

AbstractFluorescence‐activated cell sorting (FACS) was used to establish clonal populations of a human lymphoblastoid cell strain that contain spontaneously occurring and N‐methyl‐N'‐nitro‐N‐nitrosoguanidine‐induced mutations in the lambda immunoglobulin gene. Multiple rounds of FACS using a monoclonal antibody specific for the membrane‐expressed human lambda immunoglobulin were used to enrich the population fraction of cells lacking a wild‐type lambda immunoglobulin on the cell surface. Approximately 20% of the clonal populations established after five rounds of FACS‐mediated enrichment did not express the lambda immunoglublin epitope recognized by the monoclonal antibody used for selection. However, evaluation of the FACS‐selected mutant clonal populations with a polyclonal antilambda antibody, or a monoclonal antibody directed against a different epitope on the lambda immunoglobulin made by the T5‐1 cells, indicated that the mutant clonal populations expressed lambda immunoglobulin on their cell surfaces. Additionally, the presence of lambda mRNA and of both secreted and cytoplasmic lambda protein confirmed the transcription and translation of the lambda immunoglobulin gene. These data suggest that FACS‐mediated selection employing epitope‐specific monoclonal antibodies provides a powerful technique for isolation of cell populations that express mutations within the coding region of the lambda immunoglobulin gene.
Clastogenic effect of fenfluramine in mice bone marrow cells in vivo
Authors: Agarwal Kalpana , Mukherjee Anita , Sharma Archana , Sharma Ramesh , Bhardwaj Kuldip Raj , Sen Soumitra 
Published: September 2008

AbstractFenfluramine, an amphetamine derivative used in the treatment of obesity, has been evaluated in vivo in the bone marrow cells of Swiss albino mice using two cytogenetic endpoints for assessing its genotoxic and clastogenic potentials. Concentrations of 0.75, 1.5, 3.0, and 5.0 mg/kg b.w. were administered orally for the study of sister chromatid exchange frequencies and chromosome aberrations (CA). SCE frequencies showed a positive dose response; 1.5 mg/kg being the minimum effective concentration. Fen caused a prolongation of cell cycle at all concentrations. Except for the minimum therapeutic dose (0.75 mg), all other doses (1.5, 3.0, and 5.0 mg) showed a significant increase in the percentage of damaged cells over that of the vehicle control. The degree of clastogenicity was directly proportional to the dosage used and inversely related with the duration of treatment. A gradual reduction of the clastogenic potential was observed after 12 and 24 hr of exposure, indicating that the maximum effect occurs at the middle or late synthetic phase of the cell cycle. This study, probably the first detailed screening of the drug for its genotoxicity, shows that Fen is moderately clastogenic and a DNA damaging agent in vivo.
A numerical technique for laminar swirling flow at the interface between porous and homogenous fluid domains
Authors: Yu P. , Lee T. S. , Zeng Y. , Meguid S. A. , Low H. T. 
Published: September 2008

AbstractThere have been a few recent numerical implementations of the stress‐jump condition at the interface of conjugate flows, which couple the governing equations for flows in the porous and homogenous fluid domains. These previous demonstration cases were for two‐dimensional, planar flows with simple geometries, for example, flow over a porous layer or flow through a porous plug. The present study implements the interfacial stress‐jump condition for a non‐planar flow with three velocity components, which is more realistic in terms of practical flow applications. The steady, laminar, Newtonian flow in a stirred micro‐bioreactor with a porous scaffold inside was investigated. It is shown how to implement the interfacial jump condition on the radial, axial, and swirling velocity components. To avoid a full three‐dimensional simulation, the flow is assumed to be independent of the azimuthal direction, which makes it an axisymmetric flow with a swirling velocity. The present interface treatment is suitable for non‐flat surfaces, which is achieved by applying the finite volume method based on body‐fitted and multi‐block grids. The numerical simulations show that a vortex breakdown bubble, attached to the free surface, occurs above a certain Reynolds number. The presence of the porous scaffold delays the onset of vortex breakdown and confines it to a region above the scaffold. Copyright © 2008 John Wiley & Sons, Ltd.
High‐order accurate p‐multigrid discontinuous Galerkin solution of the Euler equations
Authors: Bassi F. , Ghidoni A. , Rebay S. , Tesini P. 
Published: September 2008

AbstractDiscontinuous Galerkin (DG) methods have proven to be perfectly suited for the construction of very high‐order accurate numerical schemes on arbitrary unstructured and possibly nonconforming grids for a wide variety of applications, but are rather demanding in terms of computational resources. In order to improve the computational efficiency of this class of methods a p‐multigrid solution strategy has been developed, which is based on a semi‐implicit Runge–Kutta smoother for high‐order polynomial approximations and the implicit Backward Euler smoother for piecewise constant approximations. The effectiveness of the proposed approach is demonstrated by comparison with p‐multigrid schemes employing purely explicit smoothing operators for several 2D inviscid test cases. Copyright © 2008 John Wiley & Sons, Ltd.
Robust design and numerical simulation on drag reduction by a mixture film for liquid turbulence in a channel
Authors: Wu Sheng‐Ju , Ouyang Kwan , Shiah Sheau‐Wen 
Published: September 2008

AbstractAn important way of increasing the speed and lowering the fuel consumption of ships is by decreasing the frictional drag. One of the most promising techniques for reducing drag is the use of air bubbles. The goal of this investigation is to establish a set of optimum robust parametric levels for drag reduction by a mixture (air–water) film in turbulent channel flow. Based on the conditions laid out by the Taguchi orthogonal array method, turbulent flows, with air bubbles injected into a channel, are simulated using commercial computational fluid dynamics software. The local shear stress on the upper wall is computed to evaluate the efficiency of drag reduction. Many factors can affect drag reduction. The factors investigated in this study are the rate of air injection, bubble size, area of air injection, flow speed, and measured position of the shear stress. These factors have been investigated through the analysis of variance, which has revealed that the rate of air injection and water flow speed dominate the efficiency of drag reduction by a mixture film. According to the results, the drag can be reduced by an average of 83.4%; and when the configuration of the parametric levels is optimum the maximum drag reduction of 88.5% is achieved. Copyright © 2008 John Wiley & Sons, Ltd.
Forecasting ability of GARCH vs Kalman filter method: evidence from daily UK time‐varying beta
Authors: Choudhry Taufiq , Wu Hao 
Published: September 2008

AbstractThis paper investigates the forecasting ability of four different GARCH models and the Kalman filter method. The four GARCH models applied are the bivariate GARCH, BEKK GARCH, GARCH‐GJR and the GARCH‐X model. The paper also compares the forecasting ability of the non‐GARCH model: the Kalman method. Forecast errors based on 20 UK company daily stock return (based on estimated time‐varying beta) forecasts are employed to evaluate out‐of‐sample forecasting ability of both GARCH models and Kalman method. Measures of forecast errors overwhelmingly support the Kalman filter approach. Among the GARCH models the GJR model appears to provide somewhat more accurate forecasts than the other bivariate GARCH models. Copyright © 2008 John Wiley & Sons, Ltd.
Why has the health inequality among infants in the US declined? Accounting for the shrinking gap
Authors: Lin Wanchuan 
Published: September 2008

AbstractGiven that wealthier people are healthier, the increase in income inequality over the past two decades has led to fears that inequalities in health have also increased. Indeed, some papers have found that health disparities have become more salient among some adult populations. Using the US Vital Statistics 1983–2000, this paper presents a new stylized fact: the infant health disparity, as measured by Apgar score, neonatal mortality and infant mortality, has been narrowing over the past two decades. This is in sharp contrast to the increasing disparities in health among adults of different educational backgrounds. Using a decomposition method, I find that the most important factor in explaining the closing gap is an increase in access to medical care. All else being equal, access to proper medical care is the most important factor in explaining the narrowing infant health gap. Demographic shifts and maternal behavior changes are also significant factors, together explaining 42.2% of the closing gap in low Apgar score, 41.4% of the closing gap in neonatal death, and 45.6% of the closing gap in infant death. Copyright © 2008 John Wiley & Sons, Ltd.
What has influenced patient health‐care expenditures in Japan?: variables of age, death, length of stay, and medical care
Authors: Sato Emi , Fushimi Kiyohide 
Published: September 2008

AbstractThis study considers variables related to health‐care expenditures associated with aging and long‐term hospitalization in Japan. We focused on daily per capita inpatient health‐care expenditures, and examined the impact of inpatient characteristics such as sex, age, survived or deceased, length of stay, adult disease, and type of medical care received during the duration of each stay. We analyzed data from the Survey of Medical‐Care Activities in Public Health Insurance by multinomial logistic regression analyses. Age of patient had little impact on per capita inpatient health‐care expenditures per day. As regards length of stay, inpatient stays of 8–14 days had a little impact on health‐care expenditures. This study suggested that these results might be due to the kind of medical care received. More research is needed to determine the appropriate medical services to reduce long‐term hospitalization. In the last month of care for patients who died, medical examinations had a great influence on health‐care expenditures. This study showed that increasing medical examinations in the end‐of‐life care needs further investigation. Copyright © 2008 John Wiley & Sons, Ltd.
Use of Molecular‐Dynamics Simulation for Optimizing Protein Stability: Consensus‐Designed Ankyrin Repeat Proteins
Authors: Winger Moritz , van Gunsteren Wilfred F. 
Published: September 2008

AbstractIn earlier work, two highly homologous (87% sequence identity) ankyrin repeat (AR) proteins, E3_5 and E3_19, were studied using molecular‐dynamics (MD) simulation. Their stabilities were compared, and it was found that the C‐terminal capping unit is unstable in the protein E3_19, in agreement with CD experiments. The different stabilities of these two very similar proteins could be explained by the different charge distributions among the AR units of the two proteins. Here, another AR protein, N3C, with yet another charge distribution has been simulated using MD, and its stability was analyzed. In agreement with the experimental data, the structure of N3C was found to be less stable than that of E3_5, but, in contrast to E3_19, secondary structure was only slightly lost, while structurally N3C is closer to E3_19 than to E3_5. The results suggest that a homogeneous charge distribution over the repeat units does enhance the stability of design AR proteins in aqueous solution, which, however, may be modulated by the bulkiness of amino‐acid side chains involved in the mutations.
A Simple Multistep Conversion of 1,2‐Dihydro‐1,1‐dimethoxynaphthalen‐2‐ones to (3,4‐Dihydro‐3,4‐dioxonaphthalen‐2‐yl)acetates
Authors: Schmidt Kerstin , Margaretha Paul 
Published: September 2008

AbstractOn irradiation (λ=350 nm) in the presence of 1,1‐dimethoxyethene, naphthalene‐1,2‐dionemonoacetals 1 regioselectively afford 1,1,4,4‐tetramethoxycyclobuta[a]naphthalen‐3‐ones 3. Sequential deprotection of these bis‐acetals first lead to 1,1‐dimethoxycyclobuta[a]naphthalene‐3,4‐diones 4 and then to cyclobuta[a]naphthalene‐1,3,4‐triones 6, which, in turn, are converted into (3,4‐dihydro‐3,4‐dioxonaphthalen‐2‐yl)acetates 7 by treatment with SiO2/MeOH/air.
Additional Minor Phytoecdysteroids of Serratula wolffii
Authors: Simon András , Liktor‐Busa Erika , Tóth Gábor , Kele Zoltán , Groska Judit , Báthori Mária 
Published: September 2008

AbstractThree new and one known ecdysteroids were identified in the MeOH extract of the roots of Serratula wolffii. The new compounds isolated were (11α)‐11‐hydroxyshidasterone (1), (2β,3α,5β,14β,22R)‐2,3,20,22,25‐pentahydroxycholest‐7‐en‐6‐one (2), and (2β,3α,5β,22R)‐2,3,20,22,25‐pentahydroxycholest‐7‐en‐6‐one (3), together with the known ponasterone A (4). This latter compound was now better characterized than earlier. The structures of compounds 1–4 were established by extensive spectroscopic techniques, including one‐ and two‐dimensional NMR methods.
Studies on the Chemistry of Tetraamminezinc(II) Dipermanganate ([Zn(NH3)4](MnO4)2): Low‐Temperature Synthesis of the Manganese Zinc Oxide (ZnMn2O4) Catalyst Precursor
Authors: Sajó István E. , Kótai László , Keresztury Gábor , Gács István , Pokol György , Kristóf János , Soptrayanov Bojan , Petrusevski Vladimir M. , Timpu Daniel , Sharma Pradeep K. 
Published: September 2008

AbstractTetraamminezinc(II) dipermanganate ([Zn(NH3)4](MnO4)2; 1) was prepared, and its structure was elucidated with XRD‐Rietveld‐refinement and vibrational‐spectroscopy methods. Compound 1 has a cubic lattice consisting of a 3D H‐bound network built from blocks formed by four MnO$\rm{ {_{4}^{-}}}$ anions and four [Zn(NH3)4]2+ cations. The other four MnO$\rm{ {_{4}^{-}}}$ anions are located in a crystallographically different environment, namely in the cavities formed by the attachment of the building blocks. A low‐temperature quasi‐intramolecular redox reaction producing NH4NO3 and amorphous ZnMn2O4 could be established occurring even at 100°. Due to H‐bonds between the [Zn(NH3)4]2+ cation and the MnO$\rm{ {_{4}^{-}}}$ anion, a redox reaction took place between the NH3 and the anion; thus, thermal deammoniation of compound 1 cannot be used to prepare [Zn(NH3)2](MnO4)2 (contrary to the behavior of the analogous perrhenate (ReO$\rm{ {_{4}^{-}}}$) complex). In solution‐phase deammoniation, a temperature‐dependent hydrolysis process leading to the formation of Zn(OH)2 and NH4MnO4 was observed. Refluxing 1 in toluene offering the heat convecting medium, followed by the removal of NH4NO3 by washing with H2O, proved to be an easy and convenient technique for the synthesis of the amorphous ZnMn2O4.
A Novel Meroterpene from Eurycorymbus cavaleriei
Authors: Cheng Lin , Song Zhi‐Hang , Zhang Peng , Zhang Min , Qu Hai‐Bin , Ma Zhong‐Jun 
Published: September 2008

AbstractA novel symmetric dimeric compound, cavalerol (1), was isolated from the 95% EtOH extract of the twigs of Eurycorymbus cavaleriei. Compound 1 contains an unprecedented dimeric skeleton with two identical chiral meroterpene moieties.
Layered‐Double‐Hydroxide‐Supported Rhodium(0): An Efficient and Reusable Catalyst for the Heck‐Type Coupling of Alkenes and Arylboronic Acids
Authors: Roy Sarabindu , Roy Moumita , Trivedi Rajiv 
Published: September 2008

AbstractLayered‐double‐hydroxide‐supported nanorhodium catalyst (LDHRh(0)) was employed in the Heck‐type coupling of alkenes 1 with arylboronic acids 2 to afford the corresponding substituted alkenes 3 in good to high yields (Table 1). The catalyst was separated by simple filtration and reused for five cycles with consistent activity.
Three Escin‐Like Triterpene Saponins: Assamicins VI, VII, and VIII from the Seeds of Aesculus assamicaGriff
Authors: Liu Hong‐Wei , Wang Man‐Yuan , Song Xue‐Ying , Xia Ying , Zhao Yi‐Song , Song Xiao‐Hong , Jiang Miao‐Miao , Zhang Xue , Gao Hao , Wang Nai‐Li , Yao Xin‐Sheng 
Published: September 2008

AbstractThree new escin‐like triterpene saponins, assamicins VI (1), VII (2), and VIII (3), were isolated from the seeds of A. assamica, together with a known saponin, isoescin Ib (4). Their structures were established as 28‐O‐acetyl‐21‐O‐(3,4‐di‐O‐angeloyl‐6‐deoxy‐β‐glucopyranosyl)‐3‐O‐{O‐β‐glucopyranosyl‐(1→2)‐O‐[β‐glucopyranosyl‐(1→4)]‐β‐glucopyranuronosyl}protoaescigenin (1), 21‐O‐angeloyl‐3‐O‐{O‐α‐rhamnopyranosyl‐(1→2)‐O‐[β‐glucopyranosyl‐(1→3)]‐β‐glucopyranuronosyl}protoaescigenin (2), and 21‐O‐angeloyl‐3‐O‐{O‐[β‐glucopyranosyl‐(1→3)]‐β‐glucopyranuronosyl}protoaescigenin (3) on the basis of spectroscopic analysis (protoaescigenin=(3β,4β,16α,21β,22α)‐olean‐12‐ene‐3,16,21,22,23,28‐hexol; angelic acid=(2Z)‐2‐methylbut‐2‐enoic acid).
Two New Eremophilane‐Type Sesquiterpenoids from the Rhizomes of Ligularia veitchiana (Hemsl.) Greenm
Authors: Wang Cai‐Fang , Zhao Yu , Liu Yan‐Ze , Zhang Zhen‐Zhong 
Published: September 2008

AbstractTwo new eremophilane‐type sesquiterpenoids eremophil‐6‐en‐11‐ol (1) and (7α,9α,10α)‐9,10‐epoxy‐eremophilan‐11‐ol (2), together with a known eremophilane‐type (6α,8α)‐6,8‐dihydroxyeremophil‐7(11)‐en‐12‐oic acid 12,8‐lactone (3) were isolated from the rhizomes of Ligularia veitchiana. The structures of 1 and 2 were established by spectral analysis including 1H‐ and 13C‐NMR, HSQC, HMBC, and HR‐ESI‐MS data. The compounds 1 and 3 were assessed against lung‐cancer (A549) and stomach‐cancer (BCG823) cell lines by the MTT method. The results showed that 1 exhibited significant inhibiting activities on the growth of these cancer cells with IC50 values between 1–100 μg/ml, whereas compound 3 had no effect on the same cell lines.
A New Triterpene and New Sesquiterpenes from the Roots of Ligularia sagitta
Authors: Li Ping‐Lin , Jia Zhong‐Jian 
Published: September 2008

AbstractOne new triterpene and seven new eremophilane‐type sesquiterpenes were isolated from the roots of Ligularia sagitta, among them 1a, an O‐acetylated oleanane type triterpene, 2a and 3a, two 11‐nor eremophilane‐type sesquiterpenes, 4a, 5, and 6, three standard eremophilane‐type sesquiterpenes, and 7 and 8, two tri‐nor eremophilane‐type sesquiterpenes. Their structures were established by extensive spectral analyses (1D, 2D‐NMR, IR, and MS). Compound 1a showed moderate cytotoxicity against two tumor cell lines.
New Open‐Chain and Cyclic Tetrapeptides, Consisting of α‐, β2‐, and β3‐Amino‐Acid Residues, as Somatostatin Mimics – A Survey
Authors: Seebach Dieter , Dubost Estelle , Mathad Raveendra I. , Jaun Bernhard , Limbach Michael , Löweneck Markus , Flögel Oliver , Gardiner James , Capone Stefania , Beck Albert K. , Widmer Hans , Langenegger Daniel , Monna Dominique , Hoyer Daniel 
Published: September 2008

AbstractCyclo‐β‐tetrapeptides are known to adopt a conformation with an intramolecular transannular hydrogen bond in solution. Analysis of this structure reveals that incorporation of a β2‐amino‐acid residue should lead to mimics of ‘α‐peptidic β‐turns’ (cf. A, B, C). It is also known that short‐chain mixed β/α‐peptides with appropriate side chains can be used to mimic interactions between α‐peptidic hairpin turns and G protein‐coupled receptors. Based on these facts, we have now prepared a number of cyclic and open‐chain tetrapeptides, 7–20, consisting of α‐, β2‐, and β3‐amino‐acid residues, which bear the side chains of Trp and Lys, and possess backbone configurations such that they should be capable of mimicking somatostatin in its affinity for the human SRIF receptors (hsst1–5). All peptides were prepared by solid‐phase coupling by the Fmoc strategy. For the cyclic peptides, the three‐dimensional orthogonal methodology (Scheme 3) was employed with best success. The new compounds were characterized by high‐resolution mass spectrometry, NMR and CD spectroscopy, and, in five cases, by a full NMR‐solution‐structure determination (in MeOH or H2O; Fig. 4). The affinities of the new compounds for the receptors hsst1–5 were determined by competition with [125I]LTT‐SRIF28 or [125I] [Tyr10]‐CST14. In Table 1, the data are listed, together with corresponding values of all β‐ and γ‐peptidic somatostatin/Sandostatin® mimics measured previously by our groups. Submicromolar affinities have been achieved for most of the human SRIF receptors hsst1–5. Especially high, specific binding affinities for receptor hsst4 (which is highly expressed in lung and brain tissue, although still of unknown function!) was observed with some of the β‐peptidic mimics. In view of the fact that numerous peptide‐activated G protein‐coupled receptors (GPCRs) recognize ligands with turn structure (Table 2), the results reported herein are relevant far beyond the realm of somatostatin: many other peptide GPCRs should be ‘reached’ with β‐ and γ‐peptidic mimics as well, and these compounds are proteolytically and metabolically stable, and do not need to be cell‐penetrating for this purpose (Fig. 5).
Five New Pregnane Glycosides from the Root Barks of Periploca sepium
Authors: Feng Jia‐Quan , Zhao Wei‐Min 
Published: September 2008

AbstractFive new pregnane glycosides, perisepiumosides A–E (1–5, resp.), along with the seven known constituents 6–12, were isolated from the root barks of Periploca sepium Bge. (Asclepiadaceae), a traditional Chinese medicine used for the treatment of rheumatoid arthritis and wounds. Their structures were characterized on the basis of spectroscopic analyses.