bluuebunny/crossref_metadata_2025_split huggingface dataset:
Theoretical study of volume changes associated with the helix–coil transition of an alanine‐rich peptide in aqueous solution
Authors: Imai Takashi , Takekiyo Takahiro , Kovalenko Andriy , Hirata Fumio , Kato Minoru , Taniguchi Yoshihiro 
Published: July 2005

AbstractThe changes in the partial molar volume (PMV) associated with the conformational transition of an alanine‐rich peptide AK16 from the α‐helix structure to various random coil structures are calculated by the three‐dimensional interaction site model (3D‐RISM) theory coupled with the Kirkwood–Buff theory. The volume change is analyzed by decomposing it into contributions from geometry and hydration: the changes in the van der Waals, void, thermal, and interaction volume. The total change in the PMV is positive. This is primarily due to the growth of void space within the peptide, which is canceled in part by the volume reduction resulting from the increase in the electrostatic interaction between the peptide and water molecules. The changes in the void and thermal volume of the coil structures are widely distributed and tend to compensate each other. Additionally, the relations between the hydration volume components and the surface properties are investigated. We categorize coil structures into extended coils with the PMV smaller than helix and general coils with the PMV larger than helix. The pressure therefore can both stabilize and destabilize the coil structures. The latter seems to be a more proper model of random coil structures of the peptide. © 2005 Wiley Periodicals, Inc. Biopolymers 79: 97–105, 2005This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Total Spontaneous Resolution of Chiral Covalent Networks from Stereochemically Labile Metal Complexes
Authors: Johansson Anna , Håkansson Mikael , Jagner Susan 
Published: July 2005

AbstractStereochemically labile copper and zinc complexes with the N,N′‐dimethylethylenediamine ligand (dmeda) have been shown to be promising precursors for the total spontaneous resolution of chiral covalent networks. (N,N′)‐[Cu(NO3)2(dmeda)]∞ crystallises as a conglomerate and yields either enantiopure (R,R)‐1 or enantiopure (S,S)‐1. A mixed‐valence copper(I/II) complex, [{CuIIBr2(dmeda)}3(CuIBr)2]∞ (2), which crystallises as a pair of interpenetrating chiral (10,3)‐a nets, is formed from CuBr, CuBr2 and dmeda. One net contains ligands with solely (R,R) configuration and exhibits helices with (P) configuration while the other has solely (S,S)‐dmeda ligands and gives rise to a net in which the helices have (M) configuration. The whole crystalline arrangement is racemic, because the interpenetrating chiral nets are of opposite handedness. With zinc chloride (R,S)‐[ZnCl(dmeda)2]2[ZnCl4] (3) is obtained, which is a network structure, although not chiral. Total spontaneous resolution of stereochemically labile metal complexes formed from achiral or racemic building blocks is suggested as a viable route for the preparation of covalent chiral networks. Once the absolute structure of the compound has been determined by X‐ray crystallography, a quantitative determination of the enantiomeric excess of the bulk product can be undertaken by means of solid‐state CD spectroscopy.
Highly Diastereoselective Diels–Alder Reactions with Enantiopure Sulfinyl‐Substituted 1‐Hydroxymethyldienes
Authors: Fernández de la Pradilla Roberto , Montero Carlos , Tortosa Mariola , Viso Alma 
Published: July 2005

AbstractEnantiopure hydroxy‐2‐ and ‐3‐sulfinyldienes undergo highly selective Diels–Alder cycloadditions with various dienophiles controlled by the chiral sulfur atom. The related hydroxy‐2‐sulfonyldienes display complementary π‐facial selectivity.
Safely reducing length of stay after open radical retropubic prostatectomy under the guidance of a clinical care pathway
Authors: Chang Sam S. , Cole Emily , Smith Joseph A. , Baumgartner Roxelyn , Wells Nancy , Cookson Michael S. 
Published: July 2005

AbstractBACKGROUNDCollaborative care pathways have proven to be a safe and effective method of decreasing length of hospital stay (LOS) and costs after radical retropubic prostatectomy (RRP). In the current study, the authors evaluated the safety and efficacy of a pathway transitioning from a 3‐day to a 2‐day LOS.METHODSThe authors performed a retrospective chart review of 994 patients who underwent RRP at the study institution between July 1994 and December 2001. A total of 561 patients were managed on a 3‐day LOS pathway, 172 were managed during the transition period from 3 to 2 days, and 261 were managed on a 2‐day LOS pathway. Statistical analysis was performed comparing preoperative variables and complications among the three groups.RESULTSNo statistically significant differences were found in comparisons of preoperative and demographic variables including age, race, medical comorbidities, preoperative prostate‐specific antigen level, clinical stage of disease at presentation, and biopsy Gleason score. Forty‐nine of the 561 patients (8.7%) remained longer than their targeted 3‐day LOS, whereas 14 of 261 patients (5.4%) were hospitalized for longer than their targeted 2‐day LOS, a difference that approached statistical significance (P = 0.058). During the transition period, 99 of 172 patients (57.6%) were discharged on postoperative Day 2 and 73 patients (42.4%) were discharged on postoperative Day 3. Complication rates were found to be significantly lower (P = 0.013) in the 2‐day LOS group (2.3%) compared with the 3‐day LOS group (7.0%) and the transition group (8.1%). The rate of readmission remained constant at 3% during this time period.CONCLUSIONSOverall, greater than 90% of patients were discharged within 2–3 days of surgery with acceptable complication rates, suggesting that in a consistent patient population, the transition from a 3‐day LOS to a 2‐day LOS can be done successfully without compromising patient safety. Evaluation currently is ongoing with regard to a 1‐day LOS. Cancer 2005. © 2005 American Cancer Society.
The feasibility of neoadjuvant high‐dose chemotherapy and autologous peripheral blood stem cell transplantation in patients with nonmetastatic high grade localized osteosarcoma
Authors: Arpaci Fikret , Ataergin Selmin , Ozet Ahmet , Erler Kaan , Basbozkurt Mustafa , Ozcan Ayhan , Komurcu Seref , Ozturk Bekir , Celasun Bulent , Kilic Selim , Kuzhan Okan 
Published: July 2005

AbstractBACKGROUNDThe primary and secondary objectives of the current study were to improve the ≥ 90% tumor necrosis rate and assess the toxicity profile of the neoadjuvant high‐dose chemotherapy (HDC) regimen, respectively.METHODSTwenty‐two patients with AJCC Stage IIB high‐grade osteosarcoma were included in the current study. Two cycles of an induction chemotherapy regimen including cisplatin, doxorubicin, and ifosfamide followed by HDC and autologous peripheral blood stem cell support or transplantation (APBSCT) were given. After engraftment was achieved, the patients underwent limb‐sparing surgery (LSS) followed by three to six cycles of postoperative chemotherapy depending on the tumor necrosis rate.RESULTSThe median follow‐up, the total duration of treatment, and the time to surgery were 23.7 months, 5.96 months, and 3.03 months, respectively. The necrosis rate was at least 90% in 82% of the cases. The 3‐year overall survival (OS) and disease‐free survival (DFS) rates were 83% and 70%, respectively. Leukopenia, anemia, thrombocytopenia, nausea and emesis, and mucositis were the most frequent Grade 3 and Grade 4 toxicities (according to the National Cancer Institute Common Toxicity Criteria [version 2.0]) of induction, high‐dose, and adjuvant chemotherapies. At the time of last follow‐up, no patient had died of chemotherapeutic toxicity. LSS was performed in all patients. Surgery‐related complications were reported in 3 of 22 patients. Functional scoring results were excellent in eight patients, good in nine patients, fair in two patients, and poor in three patients.CONCLUSIONSThe results of the current Phase II study suggest that neoadjuvant HDC provides a greater than 90% necrosis rate with acceptable toxicity. A short duration of therapy and the feasibility of LSS in all patients are additional advantages of this approach. Cancer 2005. © 2005 American Cancer Society.
Gas‐Phase Structure of N,N‐Dimethylglycine
Authors: Lesarri Alberto , Cocinero Emilio J. , López Juan C. , Alonso José L. 
Published: July 2005

AbstractThree conformers of the neutral amino acid N,N‐dimethylglycine [(CH3)2NCH2COOH] were detected in a supersonic expansion by a combination of laser ablation (LA) and molecular‐beam Fourier transform microwave (MB‐FTMW) spectroscopy. A bifurcated methyl‐to‐carbonyl (CH⋅⋅⋅OC) weak intramolecular hydrogen bond might stabilise the most stable conformer of Cs symmetry. The second most stable conformer of C1 symmetry has a hydrogen bond between the hydroxyl group and the lone pair at the nitrogen atom (N⋅⋅⋅HO). The rs and r0 structures were derived for this conformer from the rotational data for the parent and six minor 13C, 15N and OD isotopomers. A third conformer exhibits a cis‐carboxyl functional group and C1 symmetry. Ab initio MP2/6‐311++G(d,p) predictions of the spectroscopic parameters were useful in analysing the spectra. In particular, the agreement of the nuclear quadrupole coupling constants with those calculated was conclusive in identifying the different conformers.
Ab initio Study of Some Intramolecularly Donor‐Stabilized Silenes
Authors: Wandschneider Dirk , Michalik Manfred , Oehme Hartmut , Heintz Andreas 
Published: July 2005

AbstractAb initio calculations were performed to predict geometric structures, stabilizing energies and rotational barriers of some intramolecularly donor‐stabilized silenes. Calculations were performed using the HF, MP2, and B3LYP method with the 6‐31G(d) and 6‐31++G(d,p) basis set. Results were compared to experimentally available X‐ray structures and energy barriers known from temperature dependent 1H NMR measurements. Various approaches were applied to get an insight into the remarkable stability of these thermodynamically stabilized Si=C compounds. The results indicate a strong stabilizing effect of the intramolecular Si–N donor‐acceptor bond. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Self‐Assembly by Ligand‐Exchange Reactions
Authors: Chand Dillip Kumar , Manivannan Ramalingam , Sahoo Himansu S. , Jeyakumar Kandasamy 
Published: July 2005

AbstractAn interesting phenomenon of ligand exchange is observed in the DMSO solution of certain self‐assembled molecules generated from cis‐protected PdII and organic ligands. Upon heating, assemblies such as [{Pd(en)}x(ligand)y](NO3)2x change to [Pdm(ligand)n](NO3)2m and [Pd(en)2](NO3)2. The change is also possible at room temperature when 0.5 equiv. Pd(en)(NO3)2 is added in excess to the system. The transformation is incomplete when the ligand moiety is monodentate in nature, for example in the case of 4‐phenylpyridine. However, multinuclear assemblies containing nonchelating, polydentate ligands used in this study entirely favor the transformation. This process is not possible with some related PtII compounds. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Variability in the Structures of Luminescent [2‐(Aminomethyl)pyridine]silver(I) Complexes: Effect of Ligand Ratio, Anion, Hydrogen Bonding, and π‐Stacking
Authors: Feazell Rodney P. , Carson Cody E. , Klausmeyer Kevin K. 
Published: July 2005

AbstractThe reaction of 2‐(aminomethyl)pyridine (2‐amp) with silver(I) salts of triflate (OTf–), trifluoroacetate (tfa–), and tetrafluoroborate (BF4–) produce monomeric, dimeric, bridged, and polymeric structural motifs. The structural characteristics are dependent upon the ratio of ligand/metal in the structure as well as the ability of the anion to coordinate to the metal centers and form hydrogen bonds to the bound ligands. The silver coordination environment takes on several geometries including near linear (6), trigonal (4), tetrahedral (1), and both trigonal‐bipyramidal and square‐based pyramidal in a single structure (2). Structures 2, 3, and 5 also display short Ag–Ag contacts ranging from 2.8958(3) to 3.0305(4) Å. The species with metal–metal interactions, which are connectively very similar to their metal‐isolated counterparts of 1, 4, and 6, are held together only by weak π‐stacking interactions or hydrogen bonds to their respective anions. Low‐temperature luminescence spectra were collected for all compounds and are compared. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Synthesis and Electrochemical Characterization of Metallocene–PNA Oligomers
Authors: Maurer Andrea , Kraatz Heinz‐Bernhard , Metzler‐Nolte Nils 
Published: July 2005

AbstractThe synthesis of ferrocene‐ and cobaltocenium–PNA conjugates with C‐terminal cysteine residues by solid phase methods is described. Melting points with complementary DNA reveal that both metallocenes stabilize the duplex, although to a different extent. The effect is more pronounced when there is an overhang of the DNA at the PNA amino terminus. The conjugates were studied by electrochemical methods in solution. They were also immobilized on Au microelectrodes in self‐assembled monolayers (SAMs) and further characterized electrochemically on the surface. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Synthesis and Characterization of a 3D H‐Bonded Supramolecular Complex with Chiral Channels Encapsulating 1D Left‐Handed Helical Water Chains
Authors: Lou Benyong , Jiang Feilong , Yuan Daqiang , Wu Benlai , Hong Maochun 
Published: July 2005

AbstractA chiral CuII dinuclear complex [Cu2(L‐shis)2]·4H2O (H2shis = N‐salicylidenylhistidine) has been synthesized. The dinuclear units are assembled into a 3D hydrogen‐bonded supramolecular structure with 1D chiral channels through hydrogen bonds between imidazole N–H groups and carboxylate oxygen atoms. 1D left‐handed helical water chains in an AABB fashion, anchored through weak hydrogen‐bonding interactions with the host complex, are embodied in the chiral channels. X‐ray powder diffraction shows the porous structure is destroyed when the lattice water molecules are removed thermally from the channels. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Nonlinear Optical Activity and High Thermal Stability of a New 3DOpen‐Framework with Interconnected 24‐, 16‐, and 8‐Atom Channels: (NH4)Zn[O3PCH(OH)CO2]
Authors: Fu Ruibiao , Zhang Huishuang , Wang Longsheng , Hu Shengmin , Li Yaming , Huang Xihe , Wu Xintao 
Published: July 2005

AbstractHydrothermal reaction of hydroxy(phosphono)acetic acid, H2O3PCH(OH)CO2H, with zinc(II) acetate resulted in a new ammonium zinc hydroxy(phosphonato)acetate, (NH4)Zn[O3PCH(OH)CO2] (1). The structure of 1 contains a 3D open‐framework consisting of interconnected 24‐, 16‐, and 8‐atom channels. TGA and XRD reveal that the framework is stable up to 350 °C in air. Its powder SHG intensity is about 0.8 times that of potassium dihydrogen phosphate KDP. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Delineation of distinct subgroups of multiple myeloma and a model for clonal evolution based on interphase cytogenetics
Authors: Cremer Friedrich W. , Bila Jelena , Buck Isabelle , Kartal Mutlu , Hose Dirk , Ittrich Carina , Benner Axel , Raab Marc S. , Theil Ann‐Cathrin , Moos Marion , Goldschmidt Hartmut , Bartram Claus R. , Jauch Anna 
Published: July 2005

AbstractTo delineate multiple myeloma (MM) subgroups and their clonal evolution, we analyzed 81 newly diagnosed patients by interphase fluorescence in situ hybridization using a comprehensive probe set for 10 chromosomes and two IGH rearrangements. A median of 5 probes per patient displayed aberrant signal numbers (range, 1–10). Additional copies most frequently found were for 15q22, 19q13, 9q34, 11q23, and 1q21. Losses commonly observed were of 13q14.3, 17p13, and 22q11. Predominance of gain or loss was quantified by a copy number score (CS) for each patient. Two peaks (CS = +3 and CS = 0) were found by plotting patient copy number scores over CS values corresponding to hyperdiploid and nonhyperdiploid MM. Cluster analysis revealed four major branches: (i) gain of 9q, 15q, 19q, and/or 11q; (ii) deletion of 13q and t(4;14); (iii) t(11;14); and (iv) gain of 1q. Statistical modeling of an oncogenetic tree indicated that early independent events were gain of 15q/9q and/or 11q, t(11;14); deletion of 13q followed by t(4;14); and gain of 1q. Aberrations of 17p13, 22q11, 8p12, and 6q21 were found as subsequent events. MM with gain of 1q was delineated as a subentity with significantly higher beta‐2‐microglobulin and lower hemoglobin levels, indicating a poor prognosis. From our results, we propose a model of MM for clonal evolution. © 2005 Wiley‐Liss, Inc.
A BCR–JAK2 fusion gene as the result of a t(9;22)(p24;q11.2) translocation in a patient with a clinically typical chronic myeloid leukemia
Authors: Griesinger Frank , Hennig Heike , Hillmer Frauke , Podleschny Martina , Steffens Rainer , Pies Andreas , Wörmann Bernhard , Haase Detlef , Bohlander Stefan K. 
Published: July 2005

AbstractChronic myeloid leukemia (CML) is characterized by the presence of a t(9;22)(q34;q11.2), which leads to the well‐known BCR–ABL1 fusion protein. We describe a patient who was diagnosed clinically with a typical CML but on cytogenetic analysis was found to have a t(9;22)(p24;q11.2). Chromosomal fluorescence in situ hybridization showed that the BCR gene locus spanned the breakpoint at band 22q11.2 but that the ABL1 gene was not rearranged. By means of a candidate gene approach, the JAK2 gene, at 9p24, was identified as the fusion partner of BCR in this case. The BCR–JAK2 fusion protein contains the coiled‐coil dimerization domain of BCR and the protein tyrosine kinase domain (JH1) of JAK2. The patient's disease did not respond to Imatinib, and this unresponsiveness was most likely a result of the BCR–JAK2 fusion protein. © 2005 Wiley‐Liss, Inc.
IGF2/H19 imprinting analysis of human germ cell tumors (GCTs) using the methylation‐sensitive single‐nucleotide primer extension method reflects the origin of GCTs in different stages of primordial germ cell development
Authors: Sievers Sonja , Alemazkour Katayoun , Zahn Susanne , Perlman Elizabeth J. , Gillis Ad J. M. , Looijenga Leendert H. J. , Göbel Ulrich , Schneider Dominik T. 
Published: July 2005

AbstractPrevious studies have demonstrated biallelic expression of the imprinted genes H19 and IGF2 and loss of DNA methylation of the SNRPN gene, indicating a common precursor cell of human germ cell tumors (GCTs), namely, the primordial germ cell (PGC). In this study, we applied the methylation‐sensitive single‐nucleotide primer extension (MS‐SNuPE) technique to the analysis of the IGF2/H19 imprinting control region (ICR) in 55 GCTs from representative clinical and histologic subgroups. Most GCTs showed low methylation at the IGF2/H19 ICR. All 8 ovarian GCTs, 9 of 10 testicular seminomas, 7 of 10 testicular nonseminomas (all in adolescents/adults), 6 of 9 testicular yolk sac tumors (YSTs), and 12 of 14 nongonadal GCTs (all in infants/children) were hypomethylated. The highest methylation was observed in three childhood YSTs (boys) and 2 of 4 spermatocytic seminomas. The latter are derived from more advanced stages of germ‐cell development. The predominantly low methylation of most of the other GCTs correlates with studies that demonstrated erasure of the methylation imprint of the IGF2/H19 ICR during embryonal PGC migration and development. These findings suggest that the IGF2/H19 methylation status in GCTs might reflect preservation of the physiologic imprinting erasure in PGCs rather than a loss of imprinting in a sense that is accepted for somatic tumors. Furthermore, this study indicates that imprinting control mechanisms other than the proposed CTCF (CCCTC binding factor) boundary model regulate IGF2 expression during this stage of PGC development as well as in GCTs derived from PGC. © 2005 Wiley‐Liss, Inc.
Adult human subventricular, subgranular, and subpial zones contain astrocytes with a specialized intermediate filament cytoskeleton
Authors: Roelofs Reinko F. , Fischer David F. , Houtman Simone H. , Sluijs Jacqueline A. , Van Haren Wendy , Van Leeuwen Fred W. , Hol Elly M. 
Published: July 2005

AbstractHuman glial fibrillary acidic protein‐δ (GFAP‐δ) is a GFAP protein isoform that is encoded by an alternative splice variant of the GFAP‐gene. As a result, GFAP‐δ protein differs from the predominant splice form, GFAP‐α, by its C‐terminal protein sequence. In this study, we show that GFAP‐δ protein is not expressed by all GFAP‐expressing astrocytes but specifically by a subpopulation located in the subpial zone of the cerebral cortex, the subgranular zone of the hippocampus, and, most intensely, by a ribbon of astrocytes following the ependymal layer of the cerebral ventricles. Therefore, at least in the sub ventricular zone (SVZ), GFAP‐δ specifically marks the population of astrocytes that contain the neural stem cells in the adult human brain. Interestingly, the SVZ astrocytes actively splice GFAP‐δ transcripts, in contrast to astrocytes adjacent to this layer. Furthermore, we show that GFAP‐δ protein, unlike GFAP‐α, is not upregulated in astrogliosis. Our data therefore indicate a different functional role for GFAP‐δ in astrocyte physiology. Finally, transfection studies showed that GFAP‐δ protein expression has a negative effect on GFAP filament formation, and therefore could be important for modulating intermediate filament cytoskeletal properties, possibly facilitating astrocyte motility. Further studies on GFAP‐δ and the cells that express it are important for gaining insights into its function during differentiation, migration and during health and disease. © 2005 Wiley‐Liss, Inc.
Degradation and drug release of phosphate glass/polycaprolactone biological composites for hard‐tissue regeneration
Authors: Kim Hae‐Won , Lee Eun‐Jung , Jun In‐Kook , Kim Hyoun‐Ee , Knowles Jonathan C. 
Published: July 2005

AbstractPhosphate‐based glass (P‐glass) and poly(ϵ‐caprolactone) (PCL) composites were fabricated in a sheet form by solvent extraction and thermal pressing methods, and the antibiotic drug Vancomycin was loaded within the composites for use as a hard‐tissue regenerative. The degradation and drug‐release rate of the composites in vitro were tailored by modifying the glass composition: 0.45P2O5‐xCaO‐(0.55‐x)Na2O, where x = 0.2, 0.3, 0.4, and 0.5. Compared to pure PCL, all the P‐glass/PCL composites degraded to a higher degree, and the composite with lower‐CaO glass showed a higher material loss. This was attributed mainly to the dissolution of the glass component. The glass dissolution also increased the degradation of PCL component in the composites. The Vancomycin release from the composites was strongly dependent on the glass composition. Drug release in pure PCL was initially abrupt and flattened out over a prolonged period. However, glass/PCL composites (particularly in the glass containing higher‐CaO) exhibited a reduced initial burst and a higher release rate later. Preliminary cell tests on the extracts from the glass/PCL composites showed favorable cell proliferation, but the level was dependent on the ionic concentration of the extracts. The cell proliferation on the diluted extracts from the composite with higher‐CaO glass was significantly higher than that on the blank culture dish. These observations confirmed that the P‐glass/PCL composites are potentially applicable for use as hard‐tissue regeneration and wound‐healing materials because of their controlled degradation and drug‐release profile as well as enhanced cell viability. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005