bluuebunny/crossref_metadata_2025_split huggingface dataset:
Soluble Arctic amyloid β protein inhibits hippocampal long‐term potentiation in vivo
Authors: Klyubin Igor , Walsh Dominic M. , Cullen William K. , Fadeeva Julia V. , Anwyl Roger , Selkoe Dennis J. , Rowan Michael J. 
Published: May 2004

AbstractMutations in the amyloid precursor protein that result in substitutions of glutamic acid at residue 22 of the amyloid β protein (Aβ) with glutamine (Q22, Dutch) or glycine (G22, Arctic) cause aggressive familial neurological diseases characterized by cerebrovascular haemorrhages or Alzheimer's‐type dementia, respectively. The present study compared the ability of these peptides to block long‐term potentiation (LTP) of glutamatergic transmission in the hippocampus in vivo. The effects of intracerebroventricular injection of wild‐type, Q22 and G22 Aβ(1–40) peptides were examined in the CA1 area of urethane‐anaesthetized rats. Both mutant peptides were ≈ 100‐fold more potent than wild‐type Aβ at inhibiting LTP induced by high‐frequency stimulation when solutions of Aβ were freshly prepared. Fibrillar material, as determined by electron microscopy, was obvious in all these peptide solutions and exhibited appreciable Congo Red binding, particularly for Aβ(1–40)G22 and Aβ(1–40)Q22. A soluble fraction of Aβ(1–40)G22, obtained following high‐speed centrifugation, retained full activity of the peptide solution to inhibit LTP, providing strong evidence that in the case of the Arctic disease a soluble nonfibrillar form of Aβ may represent the primary mediator of Aβ‐related cognitive deficits, particularly early in the disease. In contrast, nonfibrillar soluble Aβ(1–40)Q22 supernatant solution was ≈ 10‐fold less potent at inhibiting LTP than Aβ(1–40)G22, a finding consistent with fibrillar Aβ contributing to the inhibition of LTP by the Dutch peptide.
Interaction of the Sliding Clamp β-Subunit and Hda, a DnaA-Related Protein
Authors: Kurz Mareike , Dalrymple Brian , Wijffels Gene , Kongsuwan Kritaya 
Published: May 2004

ABSTRACT

In
Escherichia coli
, interactions between the replication initiation protein DnaA, the β subunit of DNA polymerase III (the sliding clamp protein), and Hda, the recently identified DnaA-related protein, are required to convert the active ATP-bound form of DnaA to an inactive ADP-bound form through the accelerated hydrolysis of ATP. This rapid hydrolysis of ATP is proposed to be the main mechanism that blocks multiple initiations during cell cycle and acts as a molecular switch from initiation to replication. However, the biochemical mechanism for this crucial step in DNA synthesis has not been resolved. Using purified Hda and β proteins in a plate binding assay and Ni-nitrilotriacetic acid pulldown analysis, we show for the first time that Hda directly interacts with β in vitro. A new β-binding motif, a hexapeptide with the consensus sequence QL[SP]LPL, related to the previously identified β-binding pentapeptide motif (QL[SD]LF) was found in the amino terminus of the Hda protein. Mutants of Hda with amino acid changes in the hexapeptide motif are severely defective in their ability to bind β. A 10-amino-acid peptide containing the
E. coli
Hda β-binding motif was shown to compete with Hda for binding to β in an Hda-β interaction assay. These results establish that the interaction of Hda with β is mediated through the hexapeptide sequence. We propose that this interaction may be crucial to the events that lead to the inactivation of DnaA and the prevention of excess initiation of rounds of replication.
Distinct Mutations in PlcR Explain Why Some Strains of theBacillus cereusGroup Are Nonhemolytic
Authors: Slamti Leyla , Perchat Stéphane , Gominet Myriam , Vilas-Bôas Gislayne , Fouet Agnès , Mock Michèle , Sanchis Vincent , Chaufaux Josette , Gohar Michel , Lereclus Didier 
Published: May 2004

ABSTRACTBacillus thuringiensis,Bacillus cereus, andBacillus anthracisare closely related species belonging to theBacillus cereusgroup.B. thuringiensisandB. cereusgenerally produce extracellular proteins, including phospholipases and hemolysins. Transcription of the genes encoding these factors is controlled by the pleiotropic regulator PlcR. Disruption ofplcRinB. cereusandB. thuringiensisdrastically reduces the hemolytic, lecithinase, and cytotoxic properties of these organisms.B. anthracisdoes not produce these proteins due to a nonsense mutation in theplcRgene. We screened 400B. thuringiensisandB. cereusstrains for their hemolytic and lecithinase properties. Eight Hly−Lec−strains were selected and analyzed to determine whether this unusual phenotype was due to a mutation similar to that found inB. anthracis. Sequence analysis of the DNA region including theplcRandpapRgenes of these strains and genetic complementation of the strains with functional copies ofplcRandpapRindicated that different types of mutations were responsible for these phenotypes. We also found that theplcRgenes of threeB. anthracisstrains belonging to different phylogenetic groups contained the same nonsense mutation, suggesting that this mutation is a distinctive trait of this species.
Identification of the Two Missing Bacterial Genes Involved in Thiamine Salvage: Thiamine Pyrophosphokinase and Thiamine Kinase
Authors: Melnick Jonathan , Lis Ewa , Park Joo-Heon , Kinsland Cynthia , Mori Hirotada , Baba Tomoya , Perkins John , Schyns Ghislain , Vassieva Olga , Osterman Andrei , Begley Tadhg P. 
Published: May 2004

ABSTRACT

The genes encoding thiamine kinase in
Escherichia coli
(
ycfN
) and thiamine pyrophosphokinase in
Bacillus subtilis
(
yloS
) have been identified. This study completes the identification of the thiamine salvage enzymes in bacteria.
Twin frequency and industrial pollution in different regions of Hesse, Germany
Authors: Obi-Osius N , Misselwitz B , Karmaus W , Witten J 
Published: May 2004

Aims:To investigate whether twinning occurs more frequently in residents in the vicinity of a toxic waste incinerator (TWI).Methods:Within a longitudinal environmental study that addressed child health second grade school children and their parents were recruited. The proportion of twinning in the TWI region was compared with two comparison areas. In a second confirmatory investigation, birth records for the years 1994–97 from the Hessian Perinatal Survey (HEPS) were accessed to determine whether the incidence of twinning was higher in regions around the TWI compared to adjacent reference areas.Results:In the environmental study, 61.5% of the children and 95% of their mothers participated. In mothers, twinning was 5.3% in the TWI region compared to 1.6% and 2.3% in the comparison regions. The proportion of mothers with fertility assessment/treatment was 5.7%, 8.3%, and 0% respectively. The prevalence of twinning was not significantly higher (4.5%) in mothers with treatment compared to mothers without (3.7%). From the HEPS, data of 20 603 births was analysed. The incidence of twins was significantly higher in areas which surround the TWI and other industries (1.4–1.6 per 100 births) compared to births in reference areas (0.8 per 100).Conclusions:Twinning rates may be associated with exposure to industrial pollution. Future environmental health studies that consider multiple births as an outcome are warranted. These should also investigate whether the incidence of monozygotic or dizygotic twinning may be associated with industrial pollution.
Promoter Analysis of Human Corticotropin-Releasing Factor (CRF) Type 1 Receptor and Regulation by CRF and Urocortin
Authors: Parham Kelly L. , Zervou Sevasti , Karteris Emmanouil , Catalano Rob D. , Old Robert W. , Hillhouse Edward W. 
Published: May 2004

AbstractWe report the full genomic organization of the human gene for the corticotropin-releasing factor (CRF) receptor type 1 (CRFR1), with complete mapping of exons 1–14. The 5′ flanking region (2.4 kb) of the gene encoding for human CRFR1 was isolated, sequenced, and characterized. Two major transcriptional start sites were determined at −265 and −238, relative to the ATG start site (+1). Transient expression of constructs containing sequentially deleted 5′-flanking sequences of CRFR1 fused to luciferase, revealed the minimal promoter sequence 370 bp in size, as shown by assays in neuroblastoma (SH-5YSY), teratocarcinoma (NT2), and adenocarcinoma (MCF 7) cell lines. CRF and UCN markedly increased promoter activity during transient CRFR1 expression studies. Similarly, CRF and UCN up-regulate the endogenous CRFR1 at the mRNA level in NT2 and MCF 7 cells. To dissect further the mechanisms involved, we have used primary myometrial cells transfected with the CRFR1 promoter. CRF and UCN increased the promoter activity, an effect blocked by protein kinase (PK)A and PKC inhibitors. Both CRF and UCN cause a positive feedback effect in primary cultures of human pregnant myometrial cells, by increasing mRNA expression of CRFR1. This effect appears to be dependent on activation of both PKA and PKC by CRF, whereas UCN′s effect was mediated solely via PKC activation. Collectively, our data suggest that the CRFR1 gene is under the influence of both CRF and UCN, acting via distinct signaling pathways to create a positive feedback loop and regulate further the transcription of the receptor.
Economic Consequences of Unused Medications in Houston, Texas
Authors: Garey Kevin W , Johle Mikki L , Behrman Kathy , Neuhauser Melinda M 
Published: May 2004

BACKGROUND: It is likely that a large amount of unused and outdated medications exists in households throughout the US; however, the amount and potential costs of these medications are unknown. OBJECTIVE: To determine the amount, types, and costs of unused medications present in a neighborhood surrounding a community pharmacy in Houston, Texas. METHODS: A community trial was conducted between April and September 2002. This pilot study investigated the quantity and types of drugs returned to a community pharmacy over a 6-month period. RESULTS: During the study period, approximately 17 000 oral pills worth over $26 000 were collected in 1315 medication containers. Medications collected were from all drug classes and types (pharmaceutical samples, over-the-counter and prescription drugs). CONCLUSIONS: This study demonstrated that an enormous amount of unused medications were present in a community in the US. Community pharmacies may be an ideal venue to collect and destroy these unused drugs.
CHINA'S HISTORY ACTIVISTS AND THE WAR OF RESISTANCE AGAINST JAPAN: History in the Making
Authors: Reilly James 
Published: May 2004

Abstract
In China over the past two decades, a group of “history activists” has maximized its professional independence, social credibility, academic resources, and international connections to usurp many traditional roles of the state in building new institutions and engaging in activism aimed at documenting and disseminating information on Japan's wartime atrocities.
Clinical assessment of behavioral coping responses: preliminary results from a brief inventory
Authors: McCracken Lance M. , Eccleston Christopher , Bell Louise 
Published: May 2004

AbstractPatients and clinicians sometimes take coping with chronic pain primarily as a process of gaining more control over pain. An alternate approach might include helping the pain sufferer to discriminate parts of their situation that can be effectively controlled from those that cannot. When faced with situations that do not yield to attempts at direct control patients may gain better results from leaving those situations as they are and investing their efforts elsewhere. This study was designed to examine this type of expanded view of coping with pain, a view that includes both attempts at control and acceptance. 200 adults seeking treatment for chronic pain were the subjects of this investigation. They completed a number of self‐report inventories including a measure called the Brief Pain Coping Inventory, an inventory assessing accepting responses to pain as well as pain management responses standardly targeted by cognitive‐behavioral treatment methods. Preliminary results showed that the BPCI yields scores with adequate temporal consistency and validity. Further results showed that a number of the responses assessed by the BPCI were reliable predictors of patient functioning. In general less frequent struggling to control pain, fewer palliative and avoidant coping responses, and more explicit persistence with activity despite acknowledged pain were associated with less depression and anxiety and greater life functioning. These results demonstrate that, in some instances, attempts at avoidance and control of chronic pain may be less helpful compared with a willingness to experience pain and focus on functioning.
Recent Advances in Hydrogen Storage in Metal‐Containing Inorganic Nanostructures and Related Materials
Authors: Seayad A. M. , Antonelli D. M. 
Published: May 2004

AbstractAn overview of recent advances in the application of non‐carbonaceous nanostructured and composite materials in hydrogen storage is presented in this review. The main focus is on complex hydrides, non‐graphitic nanotubes, and other porous composite and framework materials, since carbon nanotubes have been the subject of numerous other reviews. Recent advances in the area of alanates show a promising reversible absorption capability of up to 5 %, closing in on the projected Department of Energy (DOE) target of 6 %. Non‐carbon nanotubes mainly showed a sorption capacity of 1–3 wt.‐%, although a promising level of 4.2 wt.‐% is shown by boron nitride nanotubes after collapse of their walls. Other interesting materials included here are lithium nitride and porous metallo‐organic frameworks.
[Ag6(PMo10V2O40)] (CH3COO)×8H2O: A 3D Macrocationic Polyoxometallic Keggin Complex.
Authors: Liu Feng‐Xian , Marchal‐Roch Catherine , Bouchard Philippe , Marrot Jerome , Simonato Jean‐Pierre , Herve Gilbert , Secheresse Francis 
Published: May 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Generation of Strong, Homochiral Bases by Electrochemical Reduction of Phenazine Derivatives.
Authors: Alonso A. Mateo , Horcajada Roberto , Groombridge Helen J. , Mandalia Reshma , Motevalli Majid , Utley James H. P. , Wyatt Peter B. 
Published: May 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
4,4′‐ and 5,5′‐DiamBINAP as a Hydrosoluble Chiral Ligand: Syntheses and Use in Ru(II) Asymmetric Biphasic Catalytic Hydrogenation.
Authors: Berthod Mikael , Saluzzo Christine , Mignani Gerard , Lemaire Marc 
Published: May 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Trimethylaluminum‐Promoted Rearrangements of Unsaturated Sugars into Cyclohexanes.
Authors: Jia Cai , Pearce Alan J. , Bleriot Yves , Zhang Yongmin , Zhang Li‐He , Sollogoub Matthieu , Sinay Pierre 
Published: May 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Poly(ethylene glycol)‐Supported TEMPO: An Efficient, Recoverable Metal‐Free Catalyst for the Selective Oxidation of Alcohols.
Authors: Pozzi Gianluca , Cavazzini Marco , Quici Silvio , Benaglia Maurizio , Dell'Anna Gianmaria 
Published: May 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Recyclable 2nd Generation Ionic Liquids as Green Solvents for the Oxidation of Alcohols with Hypervalent Iodine Reagents.
Authors: Yadav J. S. , Reddy B. V. S. , Basak A. K. , Narsaiah A. Venkat 
Published: May 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis and Catalytic Activity of a Poly(N,N‐dialkylcarbodiimide)/Palladium Nanoparticle Composite: A Case in the Suzuki Coupling Reaction Using Microwave and Conventional Heating.
Authors: Liu Yubiao , Khemtong Chalermchai , Hu Jun 
Published: May 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
The β‐Lactone Route to α,β‐Unsaturated δ‐Lactones. Total Syntheses of (.+‐.)‐Goniothalamin and (‐)‐Massoialactone.
Authors: Fournier Lycia , Kocienski Philip , Pons Jean‐Marc 
Published: May 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
EI‐2346, a Novel Interleukin‐1β Converting Enzyme Inhibitor Produced by Streptomyces sp. E‐2346. Part 1. Taxonomy of Producing Strain, Fermentation, Isolation, Physico‐chemical Properties, and Biological Properties.
Authors: Koizumi Fumito , Hasegawa Atsuhiro , Ochiai Keiko , Ando Katsuhiko , Kondo Hidemasa , Yoshida Mayumi , Matsuda Yuzuru , Nakanishi Satoshi 
Published: May 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Search of long biphase sequences for pulse compression using fractal dimension
Authors: Araki Kan , Miyoshi Akito 
Published: May 2004

AbstractIn this paper, we propose a search technique for low sidelobe, long biphase sequences that uses the fractal dimension and reduces the computational complexity. We selected the Legendre Sequence (LS) code having a compression ratio that can be relatively freely selected and can be easily implemented in hardware as the original code sequence, which becomes the starting point of the search. With the fractal dimension of a sign run of this sign sequence as the observed parameter of the decrease in the sidelobe in pulse compression, the first step is to invert each sign and search for an improvement in the sidelobe level. Furthermore, the sign inversion position is limited and the search computational complexity is drastically reduced by the sign decision of a change in the fractal dimension and the statistical distribution of the sign inversion position and the fractal dimension. By using this technique and selectively sorting the original LS code that is 1000 to 2500 signs long, an SLL improvement (maximum 1.3 dB) was seen for some codes, and the effect on existing LS codes was quantitatively verified. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(11): 87–98, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10175
A study on high‐resolution target height estimation in multipath environment—subarray configuration
Authors: Inaba Takayuki , Araki Kiyomichi 
Published: May 2004

AbstractIt is well known that a large spike error and a bias error occur in the monopulse angle measurement process (of height estimation due to sea surface reflection or road surface reflection) when height estimation of a low‐altitude target is carried out with an air traffic control radar or a tracking radar with a monopulse antenna. In this paper, a target height estimation method is proposed that can seek the estimation object with only one parameter of the target height, even if fading prevention by frequency hopping and a subarray configuration of the array antenna based on the maximum likelihood estimation method is used. By means of computer simulation, the S/N dependence and equivalent earth radius error dependence of the target height estimation error are evaluated when the conventional ΣΔ monopulse method, the maximum likelihood estimation method without frequency hopping for four subarrays, and the proposed maximum likelihood estimation method with frequency hopping are used. Even though the evaluation is within the limited conditions, it is confirmed that the proposed method can estimate the target height while fading prevention is attempted in a multipath environment. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(11): 39–48, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10208
Efficient Synthesis of Enantiomerically and Diastereomerically Pure [2.2]Paracyclophane‐Based N,O‐Ligands
Authors: Rozenberg Valeria I. , Danilova Tat’yana I. , Sergeeva Elena V. , Shouklov Ivan. A. , Starikova Zoya A. , Hopf Henning , Kühlein Klaus 
Published: May 2004

AbstractEfficient syntheses of different enantiomerically and diastereomerically pure N,O‐ligands with alkylamino and phenol groups attached to the [2.2]paracyclophane framework are described. Several transformations of the ortho‐lithiated [2.2]paracyclophan‐4‐yl diethylcarbamate 7 and the reduction of the [2.2]paracyclophane imino derivatives 3, 4, 17, 18, and 21 allow the preparation of a wide range of compounds in which the chiral environment can be controlled by the planar chiral fragment and modified by the presence of one or two additional chiral centers in the alkylamino group. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis of a Shape‐Persistent Macrocycle with Intraannular Sulfonate Groups
Authors: Fischer Matthias , Höger Sigurd 
Published: May 2004

AbstractThe synthesis of a shape‐persistent macrocycle with two intraannular sulfonate groups is described. The cylization step is the oxidative acetylene coupling of large phenylethynyl oligomers which are covalently connected to a template. The synthesis of the templated acetylenes at the template as well as the cyclization step give high product yields showing that the template‐directed approach is superior to statistical oligocyclizations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Organometallic Control over the Regiospecificity of Functionalization Reactions: 1,2,3‐Trifluorobenzene and Bromo Derivatives thereof as Substrates
Authors: Heiss Christophe , Schlosser Manfred 
Published: May 2004

AbstractIn a case study, 1,2,3‐trifluorobenzene was functionalized at each of the two vacant positions (producing the benzoic acids 1 and 2) and, in addition, bromine was introduced into all available positions (producing the benzoic acids 3−5). The required regioflexibility was achieved by applying novel organometallic recipes such as deprotonation‐triggered halogen migrations and site‐discriminating competitive halogen−metal permutations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
A Homologous Series of O‐ and N‐Functionalized 2,2‐Difluoro1,3‐benzodioxoles: an Exercise in Organometallic Methodology
Authors: Schlosser Manfred , Gorecka Joanna , Castagnetti Eva 
Published: May 2004

AbstractThe conversion of 2,2‐difluoro‐1,3‐benzodioxole, an exceptionally acidic arene, via a 4‐lithiated intermediate into more than three dozen new derivatives was conceived as a case study. The lithiated species was trapped by C0‐electrophiles (4‐toluenesulfonyl azide, fluorodimethoxyborane, iodine), C1‐electrophiles (carbon dioxide, N,N‐dimethylformamide, formaldehyde, dimethyl sulfate), C2‐electrophiles (oxalic acid diesters, oxirane), C3‐electrophiles (oxetane), and higher alkyl iodides. The resulting carboxylic acid 1a may be treated with organolithium compounds to afford ketones (e.g. 10) and the aldehyde 9 can be condensed with nitromethane or acetic anhydride under basic conditions. If not oxidized with chromium trioxide to the corresponding carboxylic acids, the alcohols 2b, 2c, and 2d can be transformed into the corresponding bromides (12) or sulfonates (13). Their condensation with nitrogen‐containing C0‐nucleophiles (hydroxylamine, sodium azide, potassium phthalimide), C1‐nucleophiles (potassium cyanide), and C2‐nucleophiles (acetonitrile) opens a convenient access to the amines 3. Other reactions gave, despite a proven track record in other areas, only moderate yields. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Reactions of Silicon Atoms with Conjugated π‐Systems: A Matrix‐Spectroscopic Study
Authors: Maier Günther , Reisenauer Hans Peter 
Published: May 2004

AbstractThe reaction of silicon atoms with cyclopentadiene and butadiene in argon at 10 K has been studied. Addition to the conjugated π‐system of cyclopentadiene occurs in a [1,4]‐fashion. Upon irradiation the π‐adduct3rearranges to the formal insertion product2which has an unusual structure. Remarkably, a photoequilibrium between the twoexo,endoisomers2and4can be observed. In the case of butadiene the addition is less stereospecific. The planar [1,4]‐adduct11is formed together with the [1,2]‐adduct14. Surprisingly, besides11a second, nonplanar [1,4]‐adduct10can be detected. The isomers11and14are transformed into10upon irradiation. The final photoproduct is silole9. The structural elucidation of the new species is based on isotopic labelling and a comparison of the experimental observations with the results from density functional calculations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)