bluuebunny/crossref_metadata_2025_split huggingface dataset:
Catalytic Activity of Partially Oxidized Transition-metal Carbide–Nitride for Oxygen Reduction Reaction in Sulfuric Acid
Authors: Ohgi Yoshiro , Ishihara Akimitsu , Shibata Yohei , Mitsushima Shigenori , Ota Ken-ichiro 
Published: May 2008

Abstract
In order to commercialize polymer electrolyte fuel cells (PEFCs) widely, partially oxidized transition-metal carbide–nitride (TM-C–N; TM = Ti, Zr, and Ta) have been investigated as new cathodes without platinum. The specimens were prepared by the electrophoretic deposition of the transition-metal carbide–nitride on titanium plate and were heat-treated at 1000 °C under flowing 2%-H2/N2 gas containing ca. 0.25% oxygen. Partially oxidized Ta-based catalysts had highest catalytic activity, followed by Ti- and Zr-based catalysts.
Radical Copolymerizations of Vinyl Monomers in a Porous Coordination Polymer
Authors: Uemura Takashi , Ono Yukari , Kitagawa Susumu 
Published: May 2008

Abstract
Radical copolymerizations of vinyl monomers, such as styrene, methyl methacrylate, and vinyl acetate, in the nanochannels of a porous coordination polymer have been studied. The results are compared with those obtained for the corresponding free radical copolymerizations, which shows a spatial confinement effect on the monomer reactivity ratios in this system.
A case–control study of seated immobility at work as a risk factor for venous thromboembolism
Authors: West Jill , Perrin Kyle , Aldington Sarah , Weatherall Mark , Beasley Richard 
Published: May 2008

Summary Objective To determine the relative risk of prolonged seated immobility at work in patients with a deep vein thrombosis (DVT) or pulmonary embolism (PE). Design A case–control study: cases and controls completed an interviewer-administered questionnaire to obtain information on risk factors for venous thromboembolism (VTE), including prolonged seated immobility at work. Univariate and multivariate logistic regression was used to determine the association between predicted variables and the probability of being a case or control. Participants Cases were patients <65 years old attending the Wellington Hospital Outpatient VTE Clinic following hospital discharge for DVT and/or PE. Controls were patients <65 years old admitted to the Coronary Care Unit at Wellington Hospital. Setting The Wellington Hospital Outpatient VTE Clinic and Coronary Care Unit. Main outcome measures Odds ratio of VTE for prolonged seated immobility. Results There were 97 cases (53 DVT, 29 PE, 15 DVT and PE), and 106 controls. In the multivariate analysis the odds ratio of VTE for prolonged seated immobility at work was 1.8 (95% CI 0.71–4.8). The maximum number of hours seated at work was associated with VTE, with the risk increasing by 10% per hour longer seated (odds ratio 1.1, 95% CI 1.0–1.2). The maximum number of hours seated at work without getting up was associated with VTE, with the risk increasing by 20% per hour longer seated (odds ratio 1.2, 95% CI 0.96–1.6). Conclusions This study provides preliminary evidence that prolonged seated immobility at work may represent a risk factor for VTE.
Significance of limb trauma as an initiating factor in chronic leg ulceration
Authors: Kulkarni S R , Gohel M S , Whyman M R , Poskitt K R 
Published: May 2008

Objectives To assess differences in clinical outcomes between patients with traumatic and spontaneous leg ulcers. Methods Consecutive leg ulcer follow-up patients seen between April 2004 and October 2005 in a specialist leg ulcer clinic were asked about the mechanism of the original ulceration. Twenty-four-week healing and 12-month recurrence rates were calculated using Kaplan-Meier analysis and outcomes were compared between groups with traumatic and spontaneous ulcers. Results Of the 300 patients assessed, 38 were excluded (incomplete data). In the remaining 262 patients, cause of ulceration was traumatic in 116/262 (44%) and spontaneous in 146/262 (56%). Age, ankle brachial pressure index <0.85 and venous reflux were equally distributed between groups with traumatic and spontaneous ulcers ( P = 0.470, 0.793, 0.965 respectively, Chi-square test). Twenty-four-week healing rates were 81% for traumatic and 67% for spontaneous ulcers ( P = 0.015, Log-Rank test). Twelve-month recurrence rates were 32% for traumatic and 33% for spontaneous ulcers ( P = 0.970, Log-rank test). Patients with traumatic ulcers suffered a total of 53 ulcer recurrences (median 0, range 0–4) compared with 89 in patients with spontaneous ulcers (median 0, range 0–8) ( P < 0.001, Mann-Whitney U test). Conclusion Approximately half of all leg ulcer patients recall a traumatic event. When managed in leg ulcer clinic, traumatic ulcers heal faster and recur less frequently than spontaneous ulcers.
Correlation of haemodynamics and ankle mobility with clinical classes of clinical, aetiological, anatomical and pathological classification in venous disease
Authors: Cavalheri G , de Godoy J M P , Belczak C E Q 
Published: May 2008

Objectives To correlate venous haemodynamic parameters of lower limbs and amplitude of ankle mobility with the clinical, aetiological, anatomical and pathological classification (CEAP) for venous disease. Methods Two hundred and eighty-four lower limbs of 142 Caucasian women were evaluated and distributed in six groups according to the CEAP classification: Group I = C0 and C1 ( n = 24); Group II = C2 ( n = 30); Group III = C3 ( n = 27); Group IV = C4 ( n = 23); Group V = C5 ( n = 20) and Group VI = C6 ( n = 18). Goniometric examinations of ankle joints and air plethysmography (APG) were performed. Analysis of variance and the Bonferroni correction, Kruskal-Wallis' non-parametric and Dunn tests were utilized for statistical analysis with the level of significance being set at 5% ( P value < 0.05). Results There were significant restrictions in ankle mobility seen by goniometry at the C5 stage. In addition, significant changes in the venous-filling index were identified at C2, changes in the ejection fraction at C4 and changes in the residual volume fraction at the C4 stage. Conclusion The evolution of the clinical state of ankles affected by venous diseases is correlated to a reduction of joint mobility and haemodynamic alterations identified using APG.
Aminaphtone in idiopathic cyclic oedema syndrome
Authors: Pereira de Godoy J M 
Published: May 2008

Objectives Idiopathic cyclic oedema syndrome is a group of clinical conditions that exhibit a vascular capillary hyperpermeability accompanied by oedema caused by the interstitial retention of fluid. The objective of the current study was to evaluate the efficacy of aminaphtone in the treatment of idiopathic cyclic oedema. Methods A total of 15 female patients with clinical diagnosis of idiopathic cyclic oedema and aged between 22 and 49 years and a mean of 37.7 years were evaluated. After diagnosis, the patients were submitted to lower limb volumetry and asked to record the weight in the morning and evening at fixed times. One tablet of aminaphtone was prescribed every 8 h and on the fifth day the patients were reassessed. Percentages and the paired t-test were utilized for statistical analysis, with an alpha error of 5% considered acceptable ( P value <0.05). Results A significant reduction in limb size was detected after treatment using aminaphtone ( P value <0.0001) with losses between 9 g and 370 g, and an average loss of 116.9 g. Variations in weights in the morning and evening were significant ( P value <0.00001) with a maximum difference of 3 kg and a minimum of 120 g. Improvements were reported for 70% of patients. Conclusion Aminaphtone is efficacious in the reduction of oedema in patients with idiopathic cyclic oedema.
Arterial disease but not hypertension predisposes to varicose veins
Authors: Mäkivaara L A , Ahti T M , Luukkaala T , Hakama M , Laurikka J O 
Published: May 2008

Objectives The aim of the study was to find out if persons with cardiovascular diseases (CVD) (arterial disease or hypertension) have additional risk of varicose veins (VV) compared with those without arterial disease (AD) or hypertension. Methods We studied, using a validated questionnaire, the prevalence and incidence of VVs in those with and without CVD in a population of 4903 including 40-, 50- and 60-year-old men and women in Tampere, Finland. During the five years of follow-up, we had a special interest on the appearance of new VVs in those without VVs at entry ( n = 3065). Results We found a higher prevalence of VVs in persons with CVD than in those without CVD (with sex and age adjusted odds ratio [OR] 1.3 [95% confidence interval, CI 1.1–1.5]). The prevalence of VVs was higher in persons with AD (OR 1.7 [CI 1.4–2.2]), but not in persons with hypertension (OR 1.1 [CI 0.9–1.2]) than in those who were free of AD or hypertension, respectively. Subjects with AD had higher incidence of VVs (incidence odds ratio, IOR 1.4 [CI 0.8–2.7]) than subjects without AD and the effect was statistically significant in women (IOR 2.2 [CI 1.1–4.5]). Also the incidence of VVs was more affected by AD than by hypertension (IOR 1.1 [CI 0.7–1.8]). Conclusion There seems to exist a relatively strong additional risk of VVs in persons with AD and practically none in those with hypertension compared to those without.
Is arteriovenous shunting involved in the development of varicosities? A study of the intraluminal pressure and oxygen content in varicose veins
Authors: Murphy M A , Hands L 
Published: May 2008

Objectives Arteriovenous (AV) shunting has been postulated as the underlying cause of varicose veins. The aim of this study was to analyse pressure and oxygen content in primary varicose veins in order to determine evidence of arterial shunting. Methods Thirty-nine patients with varicose veins underwent cannulation of varicosities. The pressure and the blood oxygen content within varicosities were measured in different positions and during exercise. Similar measurements were made in the long saphenous veins of 10 control subjects without venous disease. Results Mean pressure in varicose veins in the supine position was 12.3 mmHg (Standard deviation [SD] 3.6 mmHg). Control subjects had similar pressures measured in the long saphenous vein. No pulsatile pressure tracings were obtained. Varicosity pressures in the erect position averaged 66 mmHg (SD 9 mmHg). In all cases, the pressure correlated with the distance of the varicosity from the heart. Pressure reduction in varicosities after exercise was significantly less than that in control subjects. Recovery time (RT 90) was also significantly shorter than in the control group. Mean venous pO2 in varicosities was 4.5 kPa (SD 1.0) in the supine position dropping to 3.9 kPa (SD 0.9) on standing; these values were not significantly different to samples from control subjects. Conclusions AV shunting is unlikely to be a causative factor in the development of primary varicose veins.
Research Note—Customer Loyalty Programs: Are They Profitable?
Authors: Singh Siddharth S. , Jain Dipak C. , Krishnan Trichy V. 
Published: May 2008

Loyalty programs are very common in practice. Many researchers have worked at understanding the impact of loyalty programs on market competition and the mechanism behind it. Interestingly, almost all of the studies have explored a symmetric equilibrium where both of the competing firms offer a loyalty program. To our knowledge, the extant literature has not investigated in-depth whether asymmetric equilibrium can exist where only one firm chooses to offer a loyalty program and the other firm chooses to compete via lowering prices. Such a question is important because some markets do support such asymmetric equilibriums with respect to loyalty programs. Also, the existence of asymmetric equilibrium shows that a loyalty program need not be profitable for some firms. In this paper, we use a game-theoretic framework to investigate specific types of customer loyalty programs that provide benefit to loyal customers in the form of discount over market prices. The model considers consumer switching and includes two types of consumer heterogeneity. The first type of heterogeneity concerns the differences between customers with respect to their liking for loyalty programs, and the second type concerns the differences among the loyalty program members with respect to their ability to collect enough loyalty points to redeem loyalty rewards. By analyzing a duopoly market, we find that both symmetric equilibrium (i.e., where both competing firms offer the loyalty program) and asymmetric equilibrium (i.e., where one firm alone offers the loyalty program) can be sustained. The paper explores conditions for the existence of these two equilibriums.
The Case for Standardisation of the Management of Gallstones Spilled and not Retrieved at Laparoscopic Cholecystectomy
Authors: Mullerat J , Cooper K , Box B , Soin B 
Published: May 2008

INTRODUCTION This observational study was carried out to establish how surgeons performing laparoscopic cholecystectomy currently deal with the issue of spilled gallstones. MATERIALS AND METHODS A questionnaire was circulated amongst laparoscopic surgeons attending the annual conference of the Association of Laparoscopic Surgery of Great Britain and Ireland in November 2006. RESULTS Eighty-two surgeons completed the questionnaire. Only half of surgeons inform patients when gallstones are spilled. Less than 30% of surgeons inform general practitioners (GPs) of this complication, when it occurs. Less than a quarter of surgeons include this information in the consent literature provided to patients. CONCLUSIONS We recommend that trusts review their policy towards spilled stones either by local audit or adopt the guidance given by the UK Healthcare Commission. While some surgeons feel informing patients and GPs may unnecessarily heighten anxiety from an uncommon complication, our review of the literature suggests this position is not tenable in the current medicolegal climate.
1,4-Additions of arylboron, -silicon, and -bismuth compounds to α,β-unsaturated carbonyl compounds catalyzed by dicationic palladium(II) complexes
Authors: Yamamoto Yasunori , Nishikata Takashi , Miyaura Norio 
Published: May 2008

AbstractAn enantioselective synthesis of cyclic and acyclic β-aryl ketone and aldehydes via Pd(II)-catalyzed 1,4-addition of Ar-m[m= B(OH)2, BF3K, Si(OMe)3, SiF3, BiAr2] to α,β-unsaturated ketones or aldehydes is described. The catalytic cycle involves transmetallation between Ar-mand Pd complexes as a key process, the mechanism of which is discussed on the basis of characterization of the transmetallation intermediate and electronic effect of the substituents. The enantioselection mechanism and efficiency of a chiraphos ligand for structurally planar α,β-unsaturated ketones are discussed on the basis of the X-ray structure of the catalyst and results of density functional theory (DFT) computational studies on the model of coordination of the substrates to the phenylpalladium(II)/(S,S)-chiraphos intermediate.
Reaction of alcohols and silyl ethers in the presence of an indium/silicon-based catalyst system: Deoxygenation and allyl substitution
Authors: Baba Akio , Yasuda Makoto , Nishimoto Yoshihiro , Saito Takahiro , Onishi Yoshiyuki 
Published: May 2008

Abstract
An In(III)/Si catalyst system effects the direct allyl substitution of alcohols and silyl ethers under mild conditions. A deoxygenation of alcohols is also promoted by InCl3 catalyst. This method requires no pretreatment or protection of hydroxy groups or deprotection of siloxy groups. The completion of the catalytic allylation depends on the low oxophilicity and high halophilicity of In(III) halide species, and other representative Lewis acids such as AlCl3 and BF3 have no catalytic activity for the allylations. The oxophilicity and halophilicity are also demonstrated by NMR studies.
Evaluation of catalytic activity of copper salts and their removal processes in the three-component coupling reactions
Authors: Hwang Seung Jun , Cho Seung Hwan , Chang Sukbok 
Published: May 2008

AbstractThe catalytic activity of a wide range of copper salts, including Cu(I) and Cu(II), has been examined in the Cu-catalyzed three-component coupling reactions of sulfonyl azides, terminal alkynes, and amines, alcohols, or water to affordN-sulfonyl amidines, imidates, and amides, respectively. Furthermore, the investigation on the ligand effect in our protocol has revealed that certain types of ligands such as tris(benzyltriazolylmethyl)amine (TBTA) exhibited notable acceleration effects on the coupling reaction. The facile and efficient methods for removing copper salts from reaction mixture were also examined.
New synthetic methodologies based on active transition metals
Authors: Alonso Francisco , Yus Miguel 
Published: May 2008

AbstractActive transition metals, namely, nickel, copper and iron, have been prepared by the reduction of the corresponding chlorides with lithium and a catalytic amount of an arene. These metals, in the form of nanoparticles, have found application in the reduction of a wide variety of functional groups as well as in the alkylation of methyl ketones with primary alcohols.
Application of rhodium-catalyzed cyclohydrocarbonylation to the syntheses of enantiopure homokainoids
Authors: Chiou Wen-Hua , Schoenfelder Angèle , Mann André , Ojima Iwao 
Published: May 2008

Abstract
Kainic acid (KA), rigidified (S)-glutamic acid, is a well-known kainite receptor agonist for excitatory transmission in the central nervous system (CNS). Our interest in highly selective kainite ligands prompted us to design a series of new kainic homologs, "homokainoids", i.e., conformationally rigidified (S)-glutamic acids. For the syntheses of enantiopure novel homokainoids (pipecolino-glutamic acids), we successfully applied the cyclohydrocarbonylation (CHC) reaction, which has been developed in these laboratories. Efficient total syntheses of enantiopure novel homokainoids from (R)-serine feature the highly diastereoselective conjugate addition and the regioselective CHC process in the key steps.
Cu(I)-catalyzed asymmetric allylation of ketones and ketimines
Authors: Kanai Motomu , Wada Reiko , Shibuguchi Tomoyuki , Shibasaki Masakatsu 
Published: May 2008

AbstractChiral CuF-catalyzed asymmetric allylation of ketones and ketimines is described. Nucleophile activation via transmetallation (allylboronate to allylcopper), which is facilitated by a cocatalyst [La(OiPr)3or LiOiPr], is key for these reactions. A CuOTf-3KOtBu-DUPHOS complex is a comparably effective catalyst that reduces the required amount of chiral phosphines.
Nickel-catalyzed carbocyanation of alkynes
Authors: Nakao Yoshiaki , Hiyama Tamejiro 
Published: May 2008

Abstract
Nickel-catalyzed carbocyanation reaction of alkynes is described. Alkynes undergo aryl- and allylcyanation reaction in the presence of nickel-phosphine catalysts to give a wide range of substituted acrylonitriles in highly stereo-, regio-, and chemoselective manners. Lewis acid cocatalysts, such as AlMe3, AlMe2Cl, and BPh3, are found to promote the arylcyanation significantly. The cooperative catalysis of nickel and Lewis acid also allows the carbocyanation reaction using alkenyl and alkyl cyanides.
Recovery of Trabecular and Cortical Bone Turnover After Discontinuation of Risedronate and Alendronate Therapy in Ovariectomized Rats
Authors: Fuchs Robyn K , Phipps Roger J , Burr David B 
Published: May 2008

AbstractAlendronate (ALN) and risedronate (RIS) are bisphosphonates effective in reducing bone loss and fractures associated with postmenopausal osteoporosis. However, it is uncertain how long it takes bone turnover to be re-established after treatment withdrawal, and whether this differs between the two drugs. The objective of this study was to determine the time required to re-establish normal bone turnover after the discontinuation of ALN and RIS treatment in an animal model of estrogen-deficiency osteoporosis. Two hundred ten, 6-mo-old female Sprague-Dawley rats were ovariectomized and 6 wk later were randomized into baseline controls (n = 10) and four treatment groups (n = 50/group): vehicle-treated controls (CON; 0.3 ml sterile water), ALN (2.4 μg/kg), low-dose RIS (RIS low; 1.2 μg/kg), and high-dose RIS (RIS high; 2.4 μg/kg). Treatments were administered 3 times/wk by subcutaneous injection. Baseline controls were killed at the initiation of treatment. Other groups were treated for 8 wk, and subgroups (n = 10/ treatment group) were killed 0, 4, 8, 12, and 16 wk after treatment was withdrawn. Static and dynamic histological analyses were performed for cortical (tibial diaphysis) and trabecular (proximal tibia and L4 vertebrae) bone. DXA and mechanical testing was performed on the L5 vertebra. After 8 wk of treatment, trabecular bone turnover rates were significantly suppressed in all drug-treated animals. Trabecular bone formation rate (BFR/BS) remained significantly lower than vehicle in bisphosphonate-treated animals through 12 wk. Sixteen weeks after treatment withdrawal, trabecular BFR/BS in the proximal tibia was re-established in animals treated with RIS but not in animals treated with ALN compared with controls. BMD of the fifth lumbar vertebra remained significantly higher than controls 16 wk after treatment withdrawal in ALN-treated animals but not in RIS-treated animals. Despite reductions in BMD and increases in bone turnover, ultimate force of the fifth lumbar vertebra remained significantly higher in all drug-treated animals through 16 wk after withdrawal.
Abdominal Aortic Calcification, BMD, and Bone Microstructure: A Population-Based Study
Authors: Chow John T , Khosla Sundeep , Melton L Joseph , Atkinson Elizabeth J , Camp Jon J , Kearns Ann E 
Published: May 2008

Abstract
To better define the relationship between vascular calcification and bone mass/structure, we assessed abdominal aortic calcification (AAC), BMD, and bone microstructure in an age-stratified, random sample of 693 Rochester, MN, residents. Participants underwent QCT of the spine and hip and high-resolution pQCT (HRpQCT) of the radius to define volumetric BMD (vBMD) and microstructural parameters. AAC was quantified with the Agatston scoring method. In men, AAC correlated with lower vertebral trabecular and femoral neck vBMD (p &lt; 0.001), but not after age or multivariable (age, body mass index, smoking status) adjustment. Separation into &lt;50 and ≥50 yr showed this pattern only in the older men. BV/TV and Tb.Th inversely correlated with AAC in all men (p &lt; 0.001), and Tb.Th remained significantly correlated after age adjustment (p &lt; 0.05). Tb.N positively correlated with AAC in younger men (p &lt; 0.001) but negatively correlated in older men (p &lt; 0.001). The opposite was true with Tb.Sp (p = 0.01 and p &lt; 0.001, respectively). Lower Tb.N and higher Tb.Sp correlated with AAC in older men even after multivariable adjustment. Among all women and postmenopausal women, AAC correlated with lower vertebral and femoral neck vBMD (p &lt; 0.001) but not after adjustment. Lower BV/TV and Tb.Th correlated with AAC (p = 0.03 and p = 0.04, respectively) in women, but not after adjustment. Our findings support an age-dependent association between AAC and vBMD. We also found that AAC correlates with specific bone microstructural parameters in older men, suggesting a possible common pathogenesis for vascular calcification and deterioration in bone structure. However, sex-specific differences exist.