bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Benzodiazepine Receptor Affinity of Derivatives of the New Tricyclic Heteroaromatic System Pyrido[3′,2′:5,6]thiopyrano[4,3‐c]pyridazin‐3(2H,5H)‐one
Authors: Primofiore Giampaolo , Da Settimo Federico , Marini Anna Maria , Simorini Francesca , La Motta Concettina , Taliani Sabrina , Laneri Sonia , Trincavelli Letizia , Martini Claudia 
Published: March 2005

AbstractDerivatives 7–13 of a new tricyclic heteroaromatic system, pyrido[3′,2′:5,6]thiopyrano[4,3‐c]pyridazin‐3(2H,5H)‐one, were prepared as potential ligands at the benzodiazepine receptor, in view of their structural analogy with potent ligands such as the pyrazoloquinolines of the CGS series II, and especially with the benzothiopyrano[4,3‐c]pyridazinones VI. They were obtained starting from the versatile ketones 2,3‐dihydrothiopyrano[2,3‐b]pyridin‐4(4H)‐one 1 and the corresponding 7‐methyl derivative 2, via condensation with glyoxylic acid, and reaction of the intermediate acid mixtures with hydrazine or substituted phenylhydrazines. When evaluated for their binding affinity at the benzo diazepine receptor in bovine cortical membranes, the target compounds 8–13 displayed an affinity in the micromolar/submicromolar order. A hypothesis is presented to rationalize these results.
An autonomously folding β‐hairpin derived from the human YAP65 WW domain: Attempts to define a minimum ligand‐binding motif
Authors: Espinosa Juan F. , Syud Faisal A. , Gellman Samuel H. 
Published: March 2005

AbstractWW domains are broadly distributed among natural proteins; these modules play a role in bringing specific proteins together. The ligands recognized by WW domains are short segments rich in proline residues. We have tried to identify the minimum substructure within a WW domain that is required for ligand binding. WW domains typically comprise ca. 40 residues and fold to a three‐stranded β‐sheet. Structural data for several WW domain/ligand complexes suggest that most or all of the intermolecular contacts involve β‐strands 2 and 3. We have developed a 16‐residue peptide that folds to a β‐hairpin conformation that appears to mimic β‐strands 2 and 3 of the human YAP65 WW domain, but this peptide does not bind to known ligands. Thus, the minimum binding domain is larger than the latter two strands of the WW domain β‐sheet. © 2005 Wiley Periodicals, Inc. Biopolymers (Pept Sci), 2005
Effects of excluded volume and polydispersity on solution properties of lentinan in 0.1 M NaOH solution
Authors: Zhang Xufeng , Xu Juan , Zhang Lina 
Published: March 2005

AbstractSeven lentinan fractions of various weight‐average molecular weights (Mw), ranging from 1.45 × 105 to 1.13 × 106 g mol−1 were investigated by static light scattering and viscometry in 0.1M NaOH solution at 25°C. The intrinsic viscosity [η] − Mw and radius of gyration 〈s2〉 − Mw relationships for lentinan in 0.1M NaOH solution were found to be represented by [η] = 5.1 × 10−3M cm3 g−1 and 〈s2〉 = 2.3 × 10−1M nm, respectively. Focusing on the effects of the Mw polydispersity with the Schulz–Zimm distribution function, the data of Mw, 〈s2〉, and [η] was analyzed on the basis of the Yoshizaki–Nitta–Yamakawa theory for the unperturbed helical wormlike chain combined with the quasi‐two‐parameter (QTP) theory for excluded‐volume effects. The persistence length, molecular weight per unit contour length, and the excluded‐volume strength were determined roughly to be 6.2 nm, 980 nm−1, and 0.1, respectively. Compared with the theoretical value calculated by the Monte Carlo model, the persistence length is longer than that of the single (1 → 3)‐β‐D‐glucan chain. The results revealed that lentinan exists as single‐stranded flexible chains in 0.1M NaOH solution with a certain degree of expansion due to the electrostatic repulsion from the interaction between the OH− anions and lentinan molecules. © 2005 Wiley Periodicals, Inc. Biopolymers 78: 187–196, 2005
Supramolecular order following binding of the dichroic birefringent sulfonic dye Ponceau SS to collagen fibers
Authors: Vidal B. C. , Mello M. L. S. 
Published: March 2005

AbstractThe optical anisotropies (linear dichroism or LD and birefringence) of crystalline aggregates of the sulfonic azo‐dye Ponceau SS and of dye complexed with chicken tendon collagen fibers were investigated in order to assess their polarizing properties and similarity to liquid crystals. In some experiments, the staining was preceded by treatment with picric acid. Crystalline fibrous aggregates of the dye had a negative LD, and their electronic transitions were oriented perpendicular to the filamentary structures. The binding of Ponceau SS molecules to the collagen fibers altered the LD signal, with variations in the fiber orientation affecting the resulting dichroic ratios. The long axis of the rod‐like dye molecule was assumed to be bound in register, parallel to the collagen fiber. Picric acid did not affect the oriented binding of the azo dye to collagen fibers. There were differences in the optical anisotropy of Ponceau SS‐stained tendons from 21‐day‐old and 41‐day‐old chickens, indicating that Ponceau SS was able to distinguish between different ordered states of macromolecular aggregation in chicken tendon collagen fibers. In the presence of dichroic rod‐like azo‐dye molecules such as Ponceau SS, collagen also formed structures with a much higher degree of orientation. The presence of LD in the Ponceau SS‐collagen complex even in unpolarized light indicated that this complex can act as a polarizer. © 2005 Wiley Periodicals, Inc. Biopolymers 78: 121–128, 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
Vibrational infrared conformational studies of model peptides representing the semicrystalline domains of Bombyx mori silk fibroin
Authors: Taddei Paola , Monti Patrizia 
Published: March 2005

AbstractThe structural organization of Bombyx mori silk fibroin was investigated by infrared (IR) spectroscopy. To this aim, (AG)15 and other model peptides of varying chain length, containing tyrosine (Y), valine (V), and serine (S) in the basic (AG)n sequence were synthesized by the solid phase method and their spectroscopic properties were determined. Both the position and the relative content of Y, V, and S residues in the (AG)n model system appeared critical in determining the preferred conformation, i.e., silk I, silk II, and unordered structures. Curve fitting analysis in the amide I range showed that the model peptides with prevailing silk II structure displayed different β‐sheet content, which was dependent on the degree of interruption of the (AG)n sequence. In this regard, the bands at about 1000 and 980 cm−1, specifically assigned to the AG sequence of the B. mori silk fibroin chain, were identified as marker of the degree of interruption of the (AG)n sequence.A stable silk I structure was observed only when the Y residue was located near the chain terminus, while a silk I → silk II conformational transition occurred when it was positioned in the central region of the peptide.Analysis of the second‐derivative spectra in the amide I range allowed us to identify a band at 1639 cm−1 (4 → 1 hydrogen‐bonded type II β‐turns), which is characteristic of the silk I conformation. © 2005 Wiley Periodicals, Inc. Biopolymers 78: 249–258, 2005
Randomized clinical trial of pylorus-preserving duodenopancreatectomy versus classical Whipple resection—long term results
Authors: Seiler C A , Wagner M , Bachmann T , Redaelli C A , Schmied B , Uhl W , Friess H , Büchler M W 
Published: March 2005

Abstract

Background
It is not known whether pylorus-preserving duodenopancreatectomy is as effective as the classical Whipple procedure in the resection of pancreatic and periampullary tumours. A prospective randomized trial was undertaken to compare the results of the two procedures.

Methods
Clinical data, histological findings, short-term results, survival and quality of life of all patients having surgery for suspected pancreatic or periampullary cancer between June 1996 and September 2001 were analysed.

Results
Two hundred and fourteen patients were randomized to undergo either a standard or a pylorus-preserving Whipple resection. After exclusion of 84 patients on the basis of intraoperative findings, 130 patients (66 standard Whipple operation and 64 pylorus-preserving resection) were entered into the trial. Of these, 110 patients with proven adenocarcinoma (57 standard Whipple and 53 pylorus-preserving resection) were analysed for long-term survival and quality of life. There was no difference in perioperative morbidity. Long-term survival, quality of life and weight gain were identical after a median follow-up of 63·1 (range 4–93) months. At 6 months, capacity to work was better after the pylorus-preserving procedure (77 versus 56 per cent; P = 0·019).

Conclusion
Both procedures were equally effective for the treatment of pancreatic and periampullary cancer. Pylorus-preserving Whipple resection offers some minor advantages in the early postoperative period, but not in the long term.
Impact of stents and abciximab on survival from cardiogenic shock treated with percutaneous coronary intervention
Authors: Huang Raymond , Sacks Jerome , Thai Hoang , Goldman Steven , Morrison Douglass A. , Barbiere Charles , Ohm Janet 
Published: March 2005

AbstractThis retrospective observational review compares patient characteristics and in‐hospital and long‐term outcomes of cohorts of patients undergoing percutaneous coronary intervention (PCI) for cardiogenic shock complicating acute myocardial infarction (MI) prior to the use of stents (as well as glycoprotein IIb/IIIa inhibitor and dual‐antiplatelet therapy) with PCI in the stent era. Cardiogenic shock remains the leading cause of hospital mortality from acute MI. This is a report of consecutive patients with cardiogenic shock complicating acute MI, without mechanical complication, referred for emergency catheterization to a single operator at two consecutive Veterans Affairs medical centers over a 15‐year period (1988 to August 2003). PCI was attempted in all 93 cases: 44 consecutive patients in the prestent era and 49 consecutive patients in the stent era. Patients with comparable extent of coronary disease, more ST elevation myocardial infarction, multiple areas of infarction, and greater comorbidity underwent PCI in the stent era. Nevertheless, PCI in the stent era was associated with higher rates of acute success and improved in‐hospital survival. Kaplan‐Meier curves and log‐rank testing showed highly significant improvement in overall survival (P < 0.0001). Logistic regression of in‐hospital survival demonstrated that stent use (collinear with glycoprotein IIb/IIIa use and dual‐antiplatelet therapy) was significantly associated with survival in a model adjusting for extent of coronary disease and comorbidities (P = 0.007). Stents and abciximab have been associated with improved acute angiographic and procedural success of PCI for cardiogenic shock, leading to improved survival. Published 2005 Wiley‐Liss, Inc.
Percutaneous closure of an aortic prosthetic paravalvular leak with an Amplatzer duct occluder
Authors: Webb John G. , Pate Gordon E. , Munt Brad I. 
Published: March 2005

AbstractFollowing aortic valve replacement, up to 5% of patients may develop clinically significant paravalular leaks. Reoperation is associated with higher mortality and an excess risk of recurrent paravalvular insufficiency. No specifically designed transcatheter device is available for paravalular leak repair. We describe in a patient with severe aortic prosthetic paravalvular leak the use of an Amplatzer duct occluder device resulting in effective closure and symptomatic improvement. © 2005 Wiley‐Liss, Inc.
Rapid progression of pericardial calcification in a patient with end‐stage renal disease
Authors: Marcu Constantin B. , Caracciolo Eugene , Donohue Thomas 
Published: March 2005

AbstractDialysis pericarditis is a relatively uncommon cause of pericardial constriction and may be found in patients with end‐stage renal disease receiving adequate renal replacement therapy. We present a patient with end‐stage renal disease maintained on chronic peritoneal dialysis who developed severe myopericardial calcification over a 2‐month period demonstrated by sequential chest computed tomographic scanning. The characteristic hemodynamic findings of constrictive‐effusive pericarditis, obtained during cardiac catheterization, are presented and discussed. © 2005 Wiley‐Liss, Inc.
Methanol Decomposition by the Use of an Assemble‐Type Microreactor
Authors: Maki T. , Ueyama T. , Mae K. 
Published: March 2005

AbstractA flexible catalytic microreactor was developed on the basis of a new concept of element assembly. The proposed reactor consists of elements of various catalysts with large surface area and reactor elements fabricated separately, and the microspace is created by optionally assembling them. A microreactor, assembled of 21 sets of elements, was used to decompose methanol for selectively producing hydrogen. At a reaction temperature of 280 °C, methanol conversion and hydrogen yield successfully reached 93 % and 1.48, respectively. Conversion increased with decreasing size of the microchannel, keeping the ratio of H2 to CO at ca. 2. This clearly shows that the reaction in the microchannel is advantageous to the conversion and selectivity compared with those reached in a conventional fixed bed reactor.
Microstructured Components for Hydrogen Production from Various Hydrocarbons
Authors: Pfeifer P. , Bohn L. , Görke O. , Haas‐Santo K. , Schubert K. 
Published: March 2005

AbstractFuel cells for mobile and decentral electricity production are of particular interest for compliance with legal regulations concerning exhaust gas emissions and for minimizing the consumption of resources in the future. With them, higher efficiencies can be achieved, noise emissions are reduced, and environmentally relevant pollutant emissions can be avoided. A problem is the supply and storage of H2 due to its small energy densities and the heavy storage systems. An alternative is the production of hydrogen where it is needed. The system components required, such as the chemical reactor/reformer and the heat exchangers need to have very good dynamics and efficiencies. Here, microstructure technology may be a solution, as extremely high thermal and mass transfer coefficients may minimize the sizes, weights, and energy losses of the devices. The present article focuses on developments made by the Institute for Micro Process Engineering in the field of hydrogen production from methane, methanol, propane, and gasoline.
Micromixer Based Liquid/Liquid Dispersion
Authors: Pennemann H. , Hardt S. , Hessel V. , Löb P. , Weise F. 
Published: March 2005

AbstractDroplet formation of various liquid/liquid systems is investigated in an interdigital micromixer made of glass. By means of the interdigital channel configuration, cylindrically shaped or lamellae‐like substreams of the dispersed phase are generated inside a continuous phase. Using the model emulsion silicon oil/water, the Rayleigh plateau instability is identified as the decay mechanism for cylindrically shaped substreams of the dispersed phase. In comparison, it is suggested by the droplet size distribution of various mixers as a function of the total flow rate that in mixers with more complex fluid‐guiding geometries droplet formation is mainly affected by shear and vortex flows.
Hermetic Gas‐tight Ceramic Microreactors
Authors: Meschke F. , Riebler G. , Hessel V. , Schürer J. , Baier T. 
Published: March 2005

AbstractNew kinds of hermetic gas‐tight ceramic microreactors for high temperatures, harsh environments, and high pressures are presented. Besides the special manufacturing procedure and design possibilities, application possibilities are also outlined. The results are complemented with examples of simulation of temperature distribution, measurement of K‐values, and thermal efficiencies on a specific cross‐flow reactor with internal manifolds. The high thermal conductivity of the ceramic results in a superior gas‐to‐gas heat transfer and in reasonable efficiencies.
Sample Pulse Broadening in Taylor Flow Microchannels for Screening Applications
Authors: Salman W. , Angeli P. , Gavriilidis A. 
Published: March 2005

AbstractThe effect of different parameters on the residence time distribution of a Taylor flow microreactor was investigated. The reactor residence time distribution was calculated from the tracer residence time distribution of a single unit cell. It was found that generally an increase in Bodenstein number, capillary number or slug length increased the spread of the residence times. A case study comparing the effect of two different sets of design and operating parameters on the distribution spread showed that spreading can be minimized by careful choice of parameters, in particular slug length.
Polymer‐Induced Alignment of dl‐Alanine Nanocrystals to Crystalline Mesostructures
Authors: Wohlrab Sebastian , Pinna Nicola , Antonietti Markus , Cölfen Helmut 
Published: March 2005

AbstractCrystallization of dl‐alanine by cooling of a supersaturated solution in the presence of a chiral double‐hydrophilic block copolymer poly(ethylene glycol)‐block‐poly(ethylene imine)‐S‐isobutyric acid (PEG4700‐PEI1200‐S‐iBAc) yields crystal superstructures with an astonishing morphology. Although analysis by light microscopy reveals these crystals to be apparently well facetted, electron microscopy shows that they consist of three‐dimensionally, well‐aligned nanocrystals that are scaffolded to a so‐called mesocrystal. This mesocrystal is formed by polymer‐mediated structuration, and provides evidence for the importance of mesoscopic events in a typical crystallization process.
High Charge‐Carrier Mobility in π‐Deficient Discotic Mesogens: Design and Structure–Property Relationship
Authors: Lehmann Matthias , Kestemont Gaël , Gómez Aspe Rafael , Buess‐Herman Claudine , Koch Michel H. J. , Debije Michael G. , Piris Jorge , de Haas Matthijs P. , Warman John M. , Watson Mark D. , Lemaur Vincent , Cornil Jérôme , Geerts Yves Henri , Gearba Raluca , Ivanov Dimitri A. 
Published: March 2005

AbstractHexaazatrinaphthylene (HATNA) derivatives with six alkylsulfanyl chains of different length (hexyl, octyl, decyl and dodecyl) have been designed to obtain new potential electron‐carrier materials. The electron‐deficient nature of these compounds has been demonstrated by cyclic voltammetry. Their thermotropic behaviour has been studied by means of differential scanning calorimetry and polarised optical microscopy. The supramolecular organisation of these discotic molecules has been explored by temperature‐dependent X‐ray diffraction on powders and oriented samples. In addition to various liquid crystalline columnar phases (Colhd, Colrd), an anisotropic plastic crystal phase is demonstrated to exist. The charge‐carrier mobilities have been measured with the pulse‐radiolysis time‐resolved microwave‐conductivity technique. They are found to be higher in the crystalline than in the liquid crystalline phases, with maximum values of approximately 0.9 and 0.3 cm2 V−1 s−1, respectively, for the decylsulfanyl derivative. Mobilities strongly depend on the nature of the side chains.
On the Reaction of Ph2PNHPPh2 with RNCS (R=Et, Ph, p‐NO2C6H4): Preparation of the Zwitterionic Ligand EtNHC(S)Ph2PNPPh2C(S)NEt (HSNS) and the Zwitterionic Metalate [(SNS)Rh(CO)]
Authors: Asti Mattia , Cammi Roberto , Cauzzi Daniele , Graiff Claudia , Pattacini Roberto , Predieri Giovanni , Stercoli Alessandro , Tiripicchio Antonio 
Published: March 2005

AbstractThe reaction of Ph2PNHPPh2 (PNP) with RNCS (Et, Ph, p‐NO2(C6H4)) gives addition products resulting from the attack of the P atoms of PNP on the electrophilic carbon atom of the isothiocyanate. When PNP is reacted with EtNCS in a 1:2 molar ratio, the zwitterionic molecule EtNHC(S)PPh2NP+Ph2C(S)N−Et (HSNS) is obtained in high yield. HSNS can be protonated (H2SNS+) or deprotonated (SNS−), behaving in the latter form as an S,N,S‐donor pincer ligand. The reaction of HSNS with [(acac)Rh(CO)2] (acac=acetylacetonate) affords the zwitterionic metalate [(SNS)Rh(CO)]. Other products can be obtained depending on the R group, the PNP/RNCS ratio (1:1 or 1:2), and the reaction temperature. The proposed product of the primary attack of PNP on RNCS, Ph2PNPPh2C(S)NHR (A), cannot be isolated. Reaction of A with another RNCS molecule leads to 1:2 addition compounds of the general formula RNHC(S)PPh2NP+Ph2C(S)N−R (1), which can rearrange into the non‐zwitterionic product RNHC(S)PPh2NP(S)Ph2 (2) by eliminating a molecule of RNC. Two molecules of A can react together, yielding 1:1 PNP/RNCS zwitterionic products of the formula RNHCH[PPh2NP(S)Ph2]PPh2NP+Ph2C(S)N−R (3). Compound 3 can then rearrange into RNHCH[PPh2NP(S)Ph2]2 (4) by losing a RNC molecule. When R=Et (a), compounds 1 a, 2 a (HSNS), and 4 a have been isolated and characterized. When R=Ph (b), compounds 2 b and 4 b can be prepared in high yield. When R=p‐NO2C6H4 (c), only compound 3 c is observed and isolated in high yield. The crystal structures of HSNS, [(SNS)Rh(CO)], and of the most representative products have been determined by X‐ray diffraction methods.
Convenient Synthesis of Multifunctional EDTA‐Based Chiral Metal Chelates Substituted with an S‐Mesylcysteine
Authors: Leonov Andrei , Voigt Brigitte , Rodriguez‐Castañeda Fernando , Sakhaii Peyman , Griesinger Christian 
Published: March 2005

AbstractWe describe the synthetic route to ethylenediaminetetraacetic acid (EDTA) derivatives that can be attached to surface‐exposed thiol functional groups of cysteine residues in proteins, via a methylthiosulfonate moiety that is connected in a stereochemically unique way to the C‐1 carbon atom of EDTA. Such compounds can be used to align proteins in solution without the need to add liquid crystalline media, and are, therefore, of great interest for the NMR spectroscopic analysis of biomolecules. The binding constant for the paramagnetic tag to lanthanide ions was determined by measuring luminescence. For the Tb+3–ligand complex, a Kb value of 6.5×1017 M−1 was obtained. This value is in excellent agreement with literature values for the related EDTA compound. In addition, it could be shown that there is no significant reduction in the luminescence intensity upon addition of a 104 excess of Ca2+ ions, indicating that this paramagnetic tag is compatible with buffers containing high concentrations of divalent alkaline earth ions.