bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis, Structures, and Properties of a Series of [Cd8Se(SePh)12Cl4]2− Cluster Compounds with Different Counterions
Authors: Eichhöfer Andreas , Hampe Oliver , Blom Martine 
Published: March 2003

AbstractA series of seven single‐crystalline ionic CdSe cluster compounds, all possessing the cluster anion [Cd8Se(SePh)12Cl4]2−, but with different counterions, has been synthesized. The compounds were characterized in the solid state, solution, and gas phases using single‐crystal XRD, powder XRD, UV/Vis spectroscopy, and FT mass spectrometry. The results of the crystal structure determination show that the increasing size of the different counterions does not simply lead to an increase in the shortest inter‐cluster distance, but rather to changes in the crystal structure. Room‐temperature UV/Vis absorption and reflectance spectra of the crystalline powders are virtually identical, proving that the electronic transitions in the energy range probed can be attributed to the cluster anion [Cd8Se(SePh)12Cl4]2−. The band of the first transition in the solid‐state UV/Vis spectra are broadened relative to that in the solution spectra, as it is possibly affected by the collective interactions between the nanoclusters in the three‐dimensional crystal lattice. Interestingly, in solution, the position and feature of the lowest‐energy transition band changes as the solvent is varied. As FT mass spectrometry gives clear evidence for the existence of the intact [Cd8Se(SePh)12Cl4]2− cluster anion in all these solutions, these shifts can be interpreted in terms of solvatochromic effects. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Lanthanide Chelates Based on Diethylenetriamine Fitted with O‐Benzoic Acid Pendant Arms
Authors: Imbert Daniel , Fatin‐Rouge Nicolas , Bünzli Jean‐Claude G. 
Published: March 2003

AbstractA new polycarboxylate ligand H5L has been synthesized by the attachment of five benzoate subunits onto a diethylenetriamine framework. Seven pKa values have been determined by potentiometry, spectrophotometry and NMR spectroscopy as 1.9(2), 2.8(2), 3.87(5), 4.58(6), 4.87(6), 9.19(6) and 11.68(5), the first four corresponding to the carboxylic functions and the last three to amine sites. The interaction between H5L and LnIII ions in dilute aqueous solution has been examined by UV/Vis absorption and emission spectrometries, and has been found to result in monometallic complexes that are moderately stable in the pH range 3.7−7.5. Conditional stability constants at pH 5.3 are logK11 = 5.3(2), 6.6(1), 6.5(1) and 7.2(3) for La, Eu, Tb and Lu, respectively. In the case of TbIII, the stability constants for [Tb(HL)]− and [Tb(H2L)] are logβ111 = 22.0(2) and logβ121 = 29.8(1), giving a pTb of 10.0. In the pH range 4−7, more than 90% of the TbIII ions are in the form of the neutral species [Tb(H2L)]. Lifetime determinations of the Eu(5D0) and Tb(5D4) excited levels in both H2O and D2O at pH 5.3 indicate 4.8 ± 0.5 (Eu) and 4.5 ± 0.5 (Tb) water molecules being bound in the inner coordination sphere of the LnIII. The triplet state of the ligand in water lies at around 26000 cm−1, resulting in a sizeable sensitisation of the Tb‐centred luminescence (absolute quantum yield: φabs = 10.3%), while the luminescence of EuIII is only poorly sensitised (φabs = 1.5%). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Manganese in Precipitated Hydroxyapatites
Authors: Mayer Isaac , Jacobsohn Orit , Niazov Tamara , Werckmann Jacques , Iliescu Monica , Richard‐Plouet Mireille , Burghaus Olaf , Reinen Dirk 
Published: March 2003

AbstractThe synthesis of Mn‐containing hydroxyapatite (HA) samples was carried out by precipitation from an aqueous solution with and without carbonate at pH 5.8−6.0. Chemical analyses have shown that Mn uptake (about 70%) is proportional to the amount of initially added Mn. The molar Ca/P ratios of the samples (1.53−1.63) indicate the formation of nonstoichiometric HA, with the higher values being obtained for the carbonated samples. Powder X‐ray diffraction (XRD) and IR spectroscopy have shown well‐defined patterns with structural data characteristic of HA. The calculated lattice constants were found to be similar to those known for HA, without any effect of the varying Mn content. High temperature treatment of selected samples was studied by XRD and IR and showed that the apatite structure is stable up to 400 °C for all samples. At 600 °C samples with low carbonate content transform partially, and at 800 °C completely, to β‐Ca3(PO4)2, while for samples with higher carbonate content (3.5−6.0%) the apatite structure is stable up to 800 °C, and a colour change to blue occurs. EPR spectroscopy reveals that manganese is divalent in all precipitated samples and present in a cubic impurity phase. After heating above 600 °C it is partially oxidized to MnV in the samples with high carbonate content and enters the HA lattice as the blue MnO43− ion. In the carbonate‐poor solids Mn2+ seems to partly occupy the Ca2+ sites in β‐Ca3(PO4)2 when sintered at temperatures above 400 °C. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
A new data model for XML databases
Authors: Ho Richard , Bai Li , Elliman David 
Published: March 2003

AbstractThe widespread activity involving the Internet and the Web causes large amounts of electronic data to be generated every day. This includes, in particular, semi‐structured textual data such as electronic documents, computer programs, log files, transaction records, literature citations, and emails. Storing and manipulating the data thus produced has proven difficult. As conventional DBMSs are not suitable for handling semi‐structured data, there is a strong demand for systems that are capable of handling large volumes of complex data in an efficient and reliable way. The Extensible Markup Language (XML) provides such solution. In this paper, we present the concept of a ‘vertical view model’ and its uses as a mapping mechanism for converting complex XML data to relational database tables, and as a standalone data model for storing complex XML data. Copyright © 2003 John Wiley & Sons, Ltd.
Geometry optimization with QM/MM, ONIOM, and other combined methods. I. Microiterations and constraints
Authors: Vreven Thom , Morokuma Keiji , Farkas Ödön , Schlegel H. Bernhard , Frisch Michael J. 
Published: March 2003

AbstractHybrid energy methods such as QM/MM and ONIOM, that combine different levels of theory into one calculation, have been very successful in describing large systems. Geometry optimization methods can take advantage of the partitioning of these calculations into a region treated at a quantum mechanical (QM) level of theory and the larger, remaining region treated by an inexpensive method such as molecular mechanics (MM). A series of microiterations can be employed to fully optimize the MM region for each optimization step in the QM region. Cartesian coordinates are used for the MM region and are chosen so that the internal coordinates of the QM region remain constant during the microiterations. The coordinates of the MM region are augmented to permit rigid body translation and rotation of the QM region. This is essential if any atoms in the MM region are constrained, but it also improves the efficiency of unconstrained optimizations. Because of the microiterations, special care is needed for the optimization step in the QM region so that the system remains in the same local valley during the course of the optimization. The optimization methodology with microiterations, constraints, and step‐size control are illustrated by calculations on bacteriorhodopsin and other systems. © 2003 Wiley Periodicals, Inc. J Comput Chem 24: 760–769, 2003
Statistical analysis of the estimation of distance measures
Authors: Pinsky Mark , Yogev‐Einot Dina , Avnir David 
Published: March 2003

AbstractDistance functions serve for quantitative evaluation of the degree of similarity, shape content, symmetry, chirality, and so on. We have developed a general methodology and a general computational tool for the estimation of the value of the distance function and of the error in that estimation, which originates in the experimental uncertainty in the location of the set of points of the studied structure (such as that expressed by the atomic displacement factor in X‐ray data analysis). © 2003 Wiley Periodicals, Inc. J Comput Chem 24: 786–796, 2003
Rice Ageing. I. Effect of Changes in Protein on Starch Behaviour
Authors: Zhou Zhongkai , Robards Kevin , Helliwell Stuart , Blanchard Chris , Baxterb Graeme 
Published: March 2003

AbstractPasting properties of starch were affected by storage at 37 °C; the most significant changes were seen in peak viscosity and breakdown. In contrast, storage at 4 °C retarded the changes. The composition of the leachate from the RVA pastes was significantly affected by storage temperature (P < 0.01) with a lesser proportion of amylose in samples stored at 37 °C. Thus, ageing was associated with decreased leaching of starch and particularly amylose. Protease treatment increased the ratio of amylose to amylopectin in the hot‐water soluble fraction significantly (P < 0.05) for samples following storage at 37 °C while the ratio did not change for samples stored at 4 °C. Of greater significance was that the ratio was the same for samples stored at both temperatures following protease treatment. Similarly, after protease treatment the peak temperatures of the gelatinisation endotherm (Tp) of samples stored at 37 °C were identical to those of the samples stored at 4 °C. Protein was considered an important factor in the ageing process and the changes in proteins associated with storage were investigated. Higher storage temperature caused a reduction in the amount of prolamin and glutelin in the propanol‐extractable fractions.
On stability of uniformly‐accelerated motions of an axially‐symmetric heavy rigid body in an ideal fluid
Authors: Deryabin M.V. 
Published: March 2003

AbstractWe consider the problem of heavy rigid body dynamics in an infinite volume of an ideal incompressible fluid performing a potential motion. If the body is axially‐symmetric, then the system admits partial solutions, when the axis of symmetry is vertical, and the body sinks and rotates around its symmetry axis. These solutions were found by V.A.Steklov already at the end of the 19th century, and he also pointed out that in general these motions are unstable (as they are uniformly accelerated).Here we consider the more delicate question, namely we derive the conditions for stability of the rotation axis direction. The method of c onstructing the Lyapunov function may be generalized for deriving stability conditions for mechanical systems with nonstationary force‐fields.
Oxothiazolidine Carboxylate Provides Protection against Hepatocellular Injury Seen after Porta Hepatis Occlusion (Pringle Maneuver) under Hypovolemic Conditions
Authors: Özgüç Halil , Tokyay Rifat , Kahveci Nevzat , Serdar Zehra , Gur Esma Surmen , Korfali Ender 
Published: March 2003

AbstractThe sensitivity of liver to warm ischemia has always been a concern for surgeons. To monitor the ischemia and/or reperfusion injury after the Pringle maneuver (occlusion of porta hepatis) in livers subjected to hemorrhage, blood pressure, blood pH, base deficit (BE), serum alanine aminotransferase (ALT), serum and liver malondialdehyde (MDA), and liver glutathione (GSH) levels were measured. MDA is a by‐product of oxidant induced lipid peroxidation, and GSH is an endogenous antioxidant. The effect of lactated Ringer’s (LR) resuscitation with or without the addition of 2‐oxothiazolidine‐4‐carboxylate (OTC), a cysteine prodrug (enhancing glutathione production) on liver injury, if any, were investigated. Rats in the sham group (n = 8) and five other groups (n = 8) underwent femoral artery and vein catheterization and laparotomy. The hemorrhage group was bled 30% of their blood volume and the ischemia group underwent occlusion of the porta hepatis 30 minutes. The hemorrhage‐ischemia (HI), LR, and OTC groups underwent both hemorrhage and occlusion. The LR and OTC groups, 30 minutes after hemorrhage, received either LR resuscitation (equivalent to three times the shed blood) or LR resuscitation plus IV OTC (100 mg/kg before clamping and 100 mg/kg after de‐clamping). Porta hepatis occlusion in the presence of hypovolemia (HI group) caused an increase in serum ALT, plasma MDA, liver MDA, and base deficit and a decrease in blood pH levels. LR resuscitation lowered only MDA (plasma and liver) and base deficit but did not reduce ALT and increase blood pH. Although liver GSH did not change, OTC kept all parameters at control levels. OTC prevents the deleterious effects of total hepatic inflow occlusion under hypovolemic conditions, but this does not occur through enhancement liver glutathione production. OTC may protect the liver by accelerating hepatic glutathione turnover, but further studies are needed to explain its mechanism of action.
Preoperative Normal Level of Parathyroid Hormone Signifies an Early and Mild Form of Primary Hyperparathyroidism
Authors: Bergenfelz Anders , Lindblom Pia , Lindergård Birger , Valdemarsson Stig , Westerdahl Johan 
Published: March 2003

AbstractContemporary patients are often diagnosed with mild or intermittent hypercalcemia. In addition, most studies demonstrate patients with parathyroid (PTH) levels in the upper normal range. The aim of the present investigation was to define subgroups of patients with mild primary hyperparathyroidism (pHPT), which could be of importance in the decision for or against surgical treatment. Two‐hundred and eleven patients, operated for pHPT were investigated with biochemical variables known to reflect PTH activity, renal function, and bone mineral content. The preoperative diagnosis of pHPT was based on the presence of hypercalcemia combined with an inappropriate serum concentration of PTH. The mean age of the patients was 64 ± 14 years and the mean serum level of calcium was 2.78 ± 0.19 mmol/L. One hundred and sixty‐two patients (77%) had raised levels of calcium and PTH the day before surgery (overt pHPT), 25 patients (12%) had a normal level of calcium and a raised PTH level (normal calcium group), and 20 patients (9%) had a raised level of calcium and a normal level of PTH (normal PTH group). In four patients the level of calcium and PTH was normal. Between‐group analysis demonstrated no major difference in symptom and signs of pHPT. Except for lower adenoma weight, patients in the normal calcium group did not essentially differ from the patients in the overt pHPT group. However, patients in the normal PTH group were a decade younger, and had better renal function, lower bone turnover, and a preserved bone density compared with patients in the overt pHPT group. In conclusion, the data from the present investigation show that pHPT patients with a preoperative normal PTH level have an early and mild form of the disease. Furthermore, the serum calcium concentration does not reflect disease severity in pHPT.
Enhanced Tumor Necrosis Factor‐α Expression in Small Sized Abdominal Aortic Aneurysms
Authors: Hamano Kimikazu , Li Tao‐Sheng , Takahashi Mutsuo , Kobayashi Toshiro , Shirasawa Bungo , Ito Hiroshi , Zempo Nobuya 
Published: March 2003

AbstractCirculating levels of tumor necrosis factor α (TNF‐α) are elevated in the patients with abdominal aortic aneurysm (AAA). We investigated TNF‐α expression and cellular infiltration in the walls of AAAs of different sizes. Twenty‐seven surgical specimens of AAAs were categorized according to the maximum aneurysm diameter into a small size group (less than 50 mm in diameter, n = 8; S group), a medium‐sized group (50 to 59 mm in diameter, n = 11; M group), and a large size group (larger than 59 mm in diameter, n = 8; L group). The level of TNF‐α and interleukin‐1β(IL‐1β) in the aneurysm wall was measured by ELISA. Immunohistochemical staining was performed to observe the TNF‐α expression and the infiltration of macrophages and lymphocytes in aneurysm walls. Enzyme‐linked immunosorbent assay showed that the level of TNF‐α in the S group (5.47 ± 3.48 pg/mg protein) was significantly higher (p < 0.05) than that in the M group (2.70 ± 1.33 pg/mg protein) or the L group (1.82 ± 1.21 pg/mg protein). No significant difference in IL‐1β was observed between the S, M, and L groups. Immunohistochemical analysis also showed that TNF‐α was expressed strongly in the S group but was negative or weakly positive in the M and L groups. Furthermore, the expression of TNF‐α was seen mainly where the aneurysm wall showed atheromatous change and macrophage infiltration. These results indicated that the expression of TNF‐α in the aneurysm wall was enhanced in small AAAs, and this enhancement might be related to the infiltration of macrophages.
Factors Affecting Mortality in Generalized Postoperative Peritonitis: Multivariate Analysis in 96 Patients
Authors: Mulier Stefaan , Penninckx Freddy , Verwaest Charles , Filez Ludo , Aerts Raymond , Fieuws Steffen , Lauwers Peter 
Published: March 2003

AbstractMortality of generalized postoperative peritonitis remains high at 22% to 55%. The aim of the present study was to identify prognostic factors by means of univariate and multivariate analysis in a consecutive series of 96 patients. Mortality was 30%. Inability to clear the abdominal infection or to control the septic source, older age, and unconsciousness were significant factors related to mortality in the multivariate analysis. Failure to control the peritoneal infection (15%) was always fatal and correlated with failed septic source control, high Acute Physiology and Chronic Health Evaluation (APACHE) II score, and male gender. Failure to control the septic source (8%) also was always fatal and correlated with high APACHE II score and therapeutic delay. In patients with immediate source control, residual peritonitis occurred in 9% after purulent or biliary peritonitis and in 41% after fecal peritonitis (p = 0.002). In patients without immediate control of the septic source, delayed control was still achieved in 100% after a planned relaparotomy (PR) strategy versus 43% after an on‐demand relaparotomy (ODR) strategy (p = 0.018). In the same patients, mortality was 0% in the PR group versus 64% in the ODR group (p = 0.007). Early relaparotomy is related to improved septic source control. After relaparotomy for generalized postoperative peritonitis, a PR strategy is indicated whenever source control is uncertain. It also might decrease mortality in fecal peritonitis. An ODR approach is adequate for purulent and biliary peritonitis with safe septic source control.
Prognostic Factors after Resection for Hepatocellular Carcinoma in Noncirrhotic Livers: Univariate and Multivariate Analysis
Authors: Chen Miin‐Fu , Tsai Hsiu‐Pei , Jeng Long‐Bin , Lee Wei‐Chen , Yeh Chun‐Nan , Yu Ming‐Chin , Hung Chao‐Ming 
Published: March 2003

AbstractThe aim of this study was to investigate the prognostic factors for hepatocellular carcinoma (HCC) in patients without cirrhosis who underwent hepatectomy. Between 1986 and 1998 a total of 197 men and 57 women with noncirrhotic HCC underwent hepatic resection in the Department of Surgery, Chang Gung Memorial Hospital, Taipei, Taiwan. We determined their surgical mortality and the disease‐free and overall cumulative survival rates. The surgical mortality was 4.7% and the 5‐year disease‐free survival rate 24.01%. By Cox regression analysis, serum alkaline phosphatase [relative risk (RR) 1.761; 95% confidence interval (CI) 1.037–2.985)], albumin (RR 2.179; CI 1.215–3.908), multiple tumor status (RR 2.288; CI 1.272–4.115), and blood urea nitrogen (RR 4.651; CI 1.116–19.38) were shown to be independent prognostic factors for the 5‐year disease‐free survival rates. The 5‐year overall cumulative survival rate was 25.91%. By Cox regression analysis, serum albumin (RR 1.656, CI 1.005–2.730), blood transfusion (RR 2.075, CI 1.153–3.731), resection margin (RR 2.562, CI 1.436–4.572), and multiple tumors (RR 2.801, CI 1.727–4.545) were shown to be significant independent factors that influenced cumulative survival rates. Hence in patients with a noncirrhotic HCC who underwent hepatectomy the prognosis depended on preoperative hepatic function, the presence of multiple tumors, the need for blood transfusion, and the surgical resection margin.
Measurement of Surgical Dexterity Using Motion Analysis of Simple Bench Tasks
Authors: Bann Simon D. , Khan Mansoor S. , Darzi Ara W. 
Published: March 2003

AbstractThe possibility of using quantitative motion analysis for objective assessment of simple surgical dexterity is investigated using the Imperial College Surgical Assessment Device (ICSAD) with qualitative analysis undertaken by inspection. Bench‐top knot tying and suturing skills were performed and examined for the ability to discriminate between surgeons of varying experience. These exercises were found to discriminate significantly between junior and senior surgeons in terms of both time taken and the number of movements required. The relation between time and motion was found to be variable depending on what skill was being undertaken: simple suturing, suturing at depth, or knot tying (1.71 vs. 1.86 vs. 2.36; p = 0.002 for 1 vs. 2; p < 0.001 for others). When the number of movements in a minute (standardized movements per minute) were considered, both groups were found to work at a similar rate, depending on the task, implying that the more experienced surgeon is more economical, performing the same exercise with fewer moves rather than with higher speed. Motion analysis exhibits face and construct validity and is a reliable assessment of simple surgical dexterity. Its use for objective assessment of dexterity and competence should be encouraged.
Beringia as an Ice Age genetic museum
Authors: Shapiro Beth , Cooper Alan 
Published: March 2003

AbstractThousands of Late Pleistocene remains are found in sites throughout Beringia. These specimens comprise an Ice Age genetic museum, and the DNA contained within them provide a means to observe evolutionary processes within populations over geologically significant time scales. Phylogenetic analyses can identify the taxonomic positions of extinct species and provide estimates of speciation dates. Geographic and temporal divisions apparent in the genetic data can be related to ecological change, human impacts, and possible landscape mosaics in Beringia. The application of ancient DNA techniques to traditional paleontological studies provides a new perspective to long-standing questions regarding the paleoenvironment and diversity of Late Pleistocene Beringia.