bluuebunny/crossref_metadata_2025 huggingface dataset:
comparative Clinical Reliability of Fasting Plasma Glucose and Glycosylated Hemoglobin in Non-Insulin-Dependent Diabetes Mellitus
Authors: Pecoraro R E , Koepsell T D , Chen M S , Lipsky B A , Belcher D W , Inui T S
Published: March 2007

Because accurate determination of glycosylated hemoglobin (GHb) is difficult and relatively expensive in comparison with the modest cost and ready availability for tests of fasting plasma glucose (FPG), we examined the reliability of repeated measurements of FPG and GHb in typical diabetic outpatients taken in the usual clinical setting. We determined FPG and GHb concurrently on three separate occasions spanning 4 wk in 41 patients with non-insulin-dependent diabetes mellitus (NIDDM) and, for contrast, 5 with insulin-dependent diabetes mellitus (IDDM). Most of the NIDDM subjects were obese, with initial FPG levels ranging from 93 to 355 mg/dl. The reliability of each test was estimated by calculatingtwo measures: the intraclass correlation coefficient (ρ1) and the coefficient of variation (CV) for the repeated test values. For NIDDM patients treated with diet or oral hypoglycemic agents (OHA), ρ1 for FPG, log(FPG), and GHb were very similar. For insulin-treated NIDDM patients, ρ1 for FPG was somewhat lower than the coefficient in other treatment groups, and the reliability of FPG by this measure did not match the reliability of GHb within the limits of statistical significance. By analyzing the CV of test values repeated within subject, the reliability of FPG did not differ from GHb in any of the NIDDM treatment groups. Although patients were recruited sequentially to minimize sample selection bias, caution must be exercised in the interpretation of the statistical analyses of reliability with either ρ1 or CV due to limitations imposed by small sample size. As anticipated, the reliability of FPG measurements among IDDM subjects was substantially lower than the test's reliability in NIDDM, whereas GHb appeared to show comparable reliability in both types of diabetes. We conclude that FPG is as reliable as GHb to indicate glycemic status in clinically stable outpatients with NIDDM treated with diet or oral agents. This contrasts with IDDM, in which the reliability of GHb is superior and FPG is unreliable.
Impaired Cardiac Adjustment to Pregnancy in Type I Diabetes
Authors: Airaksinen K E J , Ikäheimo M J , Salmela P I , Kirkinen P , Linnaluoto M K , Takkunen J T
Published: March 2007

To assess the adaptation of the heart of diabetic subjects in the natural volume overload state of pregnancy, echocardiography was performed during each trimester and postpartum in 17 women with insulindependent diabetes mellitus (IDDM) and in 11 healthy women. The mean duration of diabetes was 14 yr and signs of microvascular complications were detected in 6 patients. The diabetic women had slightly smaller left ventricles than the control women already in the basal state (postpartum), and the pregnancy-induced increase in left ventricular size and stroke volume was less in the diabetic than in the control women. The heart rate rise also tended to be less in the diabetic women, resulting in a markedly smaller increase in cardiac output in this group (1.3 vs. 3.4 L/min, P < .01). Left ventricular systolic function, wall thicknesses, or left atrial size did not differ between the groups at any point in the study. Minor collections of pericardial fluid were observed in 14 (76%) diabetic women and in 5 (45%) control women during the second and/or third trimester, but only 2 diabetic women had classic pericardial effusions. In conclusion, the normal hemodynamic adjustments to pregnancy seem to be impaired in women with IDDM. Preclinical diabetic cardiomyopathy and autonomic neuropathy may be involved in the observed alterations.
Assessment of Impact of Medicare Prospective Payment System on Care of Persons With Diabetes Mellitus
Authors: Bransome E D
Published: March 2007

Professional review organizations (PROs) have been reviewing hospital admissions on diagnosis-related groups (DRGs) 294 and 295 (uncomplicated diabetes mellitus) at the direction of the Health Care Financing Administration (HCFA) to control inappropriate hospital admissions. Because of the possibility of an adverse effect from this policy on the quality of medical care for people with diabetes, letters were sent and/or telephone calls were made to each PRO to request information on denials of admissions or of reimbursement for the hospitalization of patients with diabetes. The answers revealed variations in PRO review procedures, little attention to quality of care, and an apparently inadequate data retrieval system. These inadequacies of the Medicare Prospective Payment System (PPS), which currently obscure its impact on the quality of the hospital care of diabetic patients, can be remedied.
Diabetes Care in Rural Area: Clinical and Metabolic Evaluation
Authors: Derfler K , Waldhäusl W , Zyman H J , Howorka K , Holler C , Freyler H
Published: March 2007

To evaluate the efficacy of conventional diabetes care in a rural area, metabolic control and the presence of late complications were studied in 622 diabetic patients treated by general practitioners beyond the reach of diabetic centers. Seventy-three (12%) of the patients were classified as type I diabetics (age, 38.0 ± 16.1 yr; duration of diabetes, 12.8 ± 9.3 yr) and 549 as type II diabetics (age, 67.0 ± 10.8 yr; duration of diabetes, 7.3 ± 5.8 yr). Fifty-eight percent of type I diabetic patients administered insulin once daily and 42% twice daily, whereas most (83%) type II diabetics on insulin received only one insulin injection per day. Treatment of type II diabetic patients consisted of sulfonylureas (58%), diet alone (22%), insulin (18%), and biguanides or a combination of sulfonylurea with biguanides (2%). Poor therapeutic efficacy was observed in all patients, and postprandial hyperglycemia (blood glucose >160 mg/dl) was predominant both in type I diabetics (86%) and in type II diabetics on insulin (80%) as well as off insulin (55%). HbA1c above normal (>5.8%) was seen in 96% of type I and in 90 and 73% of type II diabetics with or without insulin therapy, respectively. Accompanying glucosuria was present in type I (73%) and in type II diabetics (on insulin, 71%; off insulin, 33%). Mean prevalence of late diabetic complications was greatest for insulin-treated patients (type I, type II with, and type II without insulin treatment: retinopathy, 41, 56, 22%; proteinuria, 13, 14, 3%; peripheral neuropathy, 21, 51, 12%), whereas macroangiopathy (16, 53, 31%) predominated in type II diabetic patients. The cumulative hospitalization period per patient increased from 33 days during the first 5 yr to 98 days for >20 yr of type I diabetes but was smaller in type II diabetics on and off insulin. We conclude that considerable effort is required to improve the course of diabetes in patients on routine treatment.
Free-Insulin Profiles After Intraperitoneal, Intramuscular, and Subcutaneous Insulin Administration
Authors: Micossi P , Cristallo M , Librenti M C , Petrella G , Galimberti G , Melandri M , Monti L , Spotti P , Scavini M , Di Carlo V , Pozza G
Published: March 2007

The aim of our study was to compare the time course of plasma free-insulin appearance after injection of equal amounts of insulin into the peritoneal cavity above and below the transverse mesocolon, intramuscularly, and subcutaneously. Seven nondiabetic subjects undergoing cholecystectomy received in random sequence 0.2 IU/kg of insulin into the peritoneal cavity above or below the transverse mesocolon. Concentrations of plasma free insulin were compared with those obtained from seven other nondiabetic subjects after repeated injections of equal amounts of insulin intramuscularly and subcutaneously. Intraperitoneal insulin above the transverse mesocolon yielded a faster rise of free insulin, peaking at 15 min, whereas intraperitoneal insulin below the transverse mesocolon produced a somewhat slower rise, peaking at 30 min. The area under the curves between 0 and 15 min was greater after the injection above than below the transverse mesocolon (P < .05). Intramuscular and subcutaneous insulin injections resulted in a slower rise of plasma free insulin, peaking at 60 and 90 min, respectively. We conclude that the pattern of insulin appearance in the plasma resembles more closely physiologic events after intraperitoneal than after subcutaneous or intramuscular insulin administration.
Assessing Effect of Mixing Insulins by Glucose-Clamp Technique in Subjects With Diabetes Mellitus
Authors: Colagiuri S , Villalobos S
Published: March 2007

The glucose-clamp technique was used to assess the effect on insulin activity of mixing clinically relevant doses of short-and longer-acting insulins in insulin-treated diabetic subjects. Mixtures of porcine regular and lente insulins resulted in a reduction in activity of the mixture compared with separate injection that was more apparent with premixing for 5 min before injecting than with premixing for 2 min. These findings were not explained by differences in volume of the injected insulin preparations. Mixing of porcine regular and bovine ultralente insulins for 2 min before injecting resulted in a reduced activity compared with separate injection. No difference in activity was obvious for porcine regular and NPH insulins given separately or premixed for 5 min. A reduction of activity during the 1st h after injection was observed when separate injection of one brand of these insulins (Velosulin or Insulatard) was compared with the manufactured mixture (Mixtard). These results indicate that premixing regular and NPH insulins in a l-to-2 ratio does not alter the biological activity compared with separate administration of the insulins. However, the mixing of regular and insulin-zinc suspensions results in a loss of insulin activity, the magnitude of which depends on the time between mixing and injecting the insulin. The clinical significance of the effect of mixing on the efficacy of subcutaneous insulin therapy should be considered in the context that this is only one of many factors that may affect the activity of subcutaneously injected insulin.
Effects of Mixing Short- and Intermediate-Acting Insulins on Absorption Course and Biologic Effect of Short-Acting Preparation
Authors: Forlani G , Santacroce G , Ciavarella A , Capelli M , Mattioli L , Vannini P
Published: March 2007

The effects of mixing short-and intermediate-acting insulins (Actrapid MC and Monotard MC) were studied in seven diabetic patients. On different days, 0.16 IU/kg of Actrapid and 0.24 IU/kg of Monotard were administered to each subject in separate injections and combined in the same syringe. Free-insulin curves and the biologic effect of insulin, assessed by the glucose-clamp technique, were compared. The absorption rate of regular insulin was higher when injected separately from the intermediate-acting preparation: the incremental areas of free insulin above basal levels, up to 90 min after the administration of the hormone, were 32 ± 5 vs. 21 ± 3μU · ml−l · min−1 (P < .02). In the same period, glucose infused to sustain glycemia showed no significant differences (2.8 ± 0.4 vs. 2.4 ± 0.3 mg · kg−1 min−1 after the administration of insulin in separate and combined injection, respectively). The difference in insulin profiles is not translated into a significant difference in glucose requirement. This might be a consequence of a flattening of the insulin dose-response curve due to insulin resistance of diabetic subjects. The slight delay in insulin action of Actrapid when mixed with Monotard is probably irrelevant in clinical practice.
Insulin Action in Insulin-Dependent Diabetics After Short-Term Thiazide Therapy
Authors: Schmitz O , Hermansen K , Hother O , Christensen C K , Arnfred J , Hansen H E , Mogensen C E , Ørskov H , Beck-Nielsen H
Published: March 2007

The influence of short-term thiazide treatment on peripheral tissue and liver sensitivity to insulin in insulin-dependent diabetes mellitus was determined by the euglycemic insulin clamp technique. A sequential three-step hyperinsulinemic clamp was performed in six insulin-dependent diabetics before and after 2 wk of hydroflumethiazide (HFT) administration in a daily dose of 75 mg. Insulin was infused at rates of 0.5, 2.0, and 4.0 mU · kg−1 · min−1, and each dose was given for at least 120 min. Glucose uptake during the last 30 min of each step was almost identical in the two situations (2.7 ± 0.6 vs.2.4±0.5mg · kg−1 min−1, 9.6 ± 0.9 vs. 9.7 ± 1.2 mg · kg−1 · min−1, and 12.0 ± 1.3 vs. 12.6 ± 1.5 min−1). Serum insulin levels were also similar, and blood glucose was kept at 100 ± 3, 2.4 ± 0.5 mg · kg−1 99 ± 4, and 97 ± 3 mg/dl before thiazides and at 93 ± 6, 93 ± 6, and 94 ± 6 mg/dl after thiazides. Another five insulin-dependent diabetics were infused with tritiated glucose followed by insulin infusion at two rates: 0.45 and 1.0 mU · kg−1 · min−1. Basal glucose output was comparable before and after thiazides (3.63 ± 0.24 vs. 2.97 ± 0.26 mg · kg−1 · min−1), as was the liver response to increasing insulin concentrations. The metabolic state as assessed by HbA1c and fasting blood glucose did not differ in the two experiments. In conclusion, short-term HFT therapy has no impact on either insulinmediated glucose uptake or sensitivity of the liver to insulin. Thus, probably no adverse effects on the metabolic state will be encountered in diabetics with minimal endogenous insulin during treatment with thiazides.
Inhaled Insulin: An Overview
Authors: White John R. , Campbell R. Keith
Published: March 2007

In Brief

Various methods of insulin administration other than injection have been sought since the discovery of insulin. For the past several years, systems that deliver insulin via the pulmonary route have been developed and evaluated. Based on available data, pulmonary insulin appears to be safe, efficacious, and well accepted by patients. This article describes the technology behind several of these pulmonary administration systems and outlines the most recent data from clinical trials evaluating pulmonary insulin.
Preventing Cardiovascular Complications of Type 2 Diabetes: Focus on Lipid Management
Authors: Henry Robert R.
Published: March 2007

IN BRIEF

Because type 2 diabetes can be considered a cardiovascular disease in its own right, current American Diabetes Association and National Cholesterol Education Program guidelines recommend aggressive treatment of dyslipidemia in people with diabetes, particularly for elevated LDL cholesterol levels. Use of appropriate treatment as determined by the pattern of lipid abnormalities can substantially reduce the risk of macrovascular disease. Institution of tight glycemic control will be beneficial to most patients, but the majority of people with diabetes will also require diet therapy, weight reduction when necessary, and intensive lipid-lowering therapy, which commonly involves one of the statins or fibric acid derivatives.
Is Postprandial Glucose Control Important? Is It Practical In Primary Care Settings?
Authors: Parkin Christopher Grainger , Brooks Neil
Published: March 2007

In Brief

Large interventional studies have shown that achieving and maintaining near-normal glycemic levels reduces the risk for microvascular and macrovascular complications in type 2 diabetes. The impact of postprandial glucose on glycemic control has become a topic of much discussion among clinicians. This article examines the literature related to the role of postprandial glucose in type 2 diabetes, both as a contributor to overall glycemia and as an independent risk factor for diabetes complications, and discusses the practicality of managing postprandial hyperglycemia in primary care settings.
Polycystic Ovary Syndrome and the Metabolic Syndrome
Authors: Sharpless Julie L.
Published: March 2007

In Brief

Many patients with polycystic ovary syndrome (PCOS) also have features of the metabolic syndrome, including insulin resistance, obesity, and dyslipidemia, suggesting an increased risk for cardiovascular disease. Increased awareness of this overlap advocates therapies that improve insulin resistance and often ameliorate PCOS symptoms.
Advances in Obesity Treatment: Clinical Highlights from the NAASO 2003 Annual Meeting
Authors: Marks Jennifer B.
Published: March 2007

In Brief

This article offers highlights from the 2003 annual meeting of the North American Association for the Study of Obesity, which was co-sponsored by the American Diabetes Association. Topics include recent research into various diets for weight loss, the relationship between obesity and polycystic ovarian syndrome, and future treatments of obesity.
Elevated Liver Function Tests in Type 2 Diabetes
Authors: Harris Elizabeth H.
Published: March 2007

IN BRIEF

Individuals with type 2 diabetes have a higher incidence of liver function test abnormalities than individuals who do not have diabetes. Mild chronic elevations of transaminases often reflect underlying insulin resistance. Elevation of transaminases within three times the upper limits of normal is not a contraindication for starting oral antidiabetic or lipid-modifying therapy. In contrast, antidiabetic agents have generally been shown to decrease alanine aminotransferase levels as tighter blood glucose levels are achieved.
Influence of general anaesthesia on the pharmacokinetics of intravenous fentanyl and its primary metabolite in horses
Authors: THOMASY S. M. , MAMA K. R. , WHITLEY K. , STEFFEY E. P. , STANLEY S. D.
Published: March 2007

Reasons for performing study: In order to evaluate its potential as an adjunct to inhalant anaesthesia in horses, the pharmacokinetics of fentanyl must first be determined.

Objectives: To describe the pharmacokinetics of fentanyl and its metabolite, N‐[1‐(2‐phenethyl‐4‐piperidinyl)maloanilinic acid (PMA), after i.v. administration of a single dose to horses that were awake inTreatment 1and anaesthetised with isoflurane inTreatment 2.

Methods: A balanced crossover design was used (n = 4/group). DuringTreatment 1, horses received a single dose of fentanyl (4 μg/kg bwt, i.v.) and duringTreatment 2, they were anaesthetised with isoflurane and maintained at 1.2 × minimum alveolar anaesthetic concentration. After a 30 min equilibration period, a single dose of fentanyl (4 μg/kg bwt, i.v.) was administered to each horse. Plasma fentanyl and PMA concentrations were measured at various time points using liquid chromatography‐mass spectrometry.

Results: Anaesthesia with isoflurane significantly decreased mean fentanyl clearance (P < 0.05). The fentanyl elimination half‐life, in awake and anaesthetised horses, was 1 h and volume of distribution at steady state was 0.37 and 0.26 l/kg bwt, respectively. Anaesthesia with isoflurane also significantly decreased PMA apparent clearance and volume of distribution. The elimination half‐life of PMA was 2 and 1.5 h in awake and anaesthetised horses, respectively.

Conclusions and potential relevance: Pharmacokinetics of fentanyl and PMA in horses were substantially altered in horses anaesthetised with isoflurane. These pharmacokinetic parameters provide information necessary for determination of suitable fentanyl loading and infusion doses in awake and isoflurane‐anaesthetised horses.
Lamellar pro‐inflammatory cytokine expression patterns in laminitis at the developmental stage and at the onset of lameness: innate vs. adaptive immune response
Authors: BELKNAP J. K. , GIGUÈRE S. , PETTIGREW A. , COCHRAN A. M. , VAN EPS A. W. , POLLITT C. C.
Published: March 2007

Reasons for performing study: Recent research has indicated that inflammation plays a role in the early stages of laminitis and that, similar to organ failure in human sepsis, early inflammatory mechanisms may lead to downstream events resulting in lamellar failure. Characterisation of the type of immune response (i.e. innate vs. adaptive) is essential in order to develop therapeutic strategies to counteract these deleterious events.

Objectives: To quantitate gene expression of pro‐inflammatory cytokines known to be important in the innate and adaptive immune response during the early stages of laminitis, using both the black walnut extract (BWE) and oligofructose (OF) models of laminitis.

Methods: Real‐time qPCR was used to assess lamellar mRNA expression of interleukins‐1β, 2, 4, 6, 8, 10, 12 and 18, and tumour necrosis factor alpha and interferon gamma at the developmental stage and at the onset of lameness.

Results: Significantly increased lamellar mRNA expression of cytokines important in the innate immune response were present at the developmental stage of the BWE model, and at the onset of acute lameness in both the BWE model and OF model. Of the cytokines characteristic of the Th1 and Th2 arms of the adaptive immune response, a mixed response was noted at the onset of acute lameness in the BWE model, whereas the response was skewed towards a Th1 response at the onset of lameness in the OF model.

Conclusions: Lamellar inflammation is characterised by strong innate immune response in the developmental stages of laminitis; and a mixture of innate and adaptive immune responses at the onset of lameness.

Potential relevance: These results indicate that anti‐inflammatory treatment of early stage laminitis (and the horse at risk of laminitis) should include not only therapeutic drugs that address prostanoid activity, but should also address the marked increases in lamellar cytokine expression.
Oral and intravenous administration of nimesulide in the horse: rational dosage regimen from pharmacokinetic and pharmacodynamic data
Authors: VILLA R. , CAGNARDI P. , BELLOLI C. , ZONCA A. , ZIZZADORO C. , FERRO E. , CARLI S.
Published: March 2007

Reasons for performing study: The selective COX‐2‐inhibitor nimesulide is used extra‐label in equine veterinary practice as an anti‐inflammatory agent. However, there are no data on which to base the rational use of the drug in this species.

Objectives: To determine the effective COX selectivity of nimesulide in the horse, and suggest a suitable dosing schedule.

Methods: The pharmacokinetics of nimesulide in the horse after oral administration (1 mg/kg bwt), and oral and i.v. administration (1.5 mg/kg bwt) were investigated, effects of feeding status on bioavailability determined, and plasma protein binding of the drug and its principal metabolites measured. Compartmental and noncompartmental pharmacokinetic analyses were performed. The plasma concentration‐time profile was used, together within vitroliterature data on nimesulide inhibition of COX isoforms, to determine the effective COX selectivity of nimesulide in the horse, and suggest a suitable dosing schedule.

Results and conclusions: The findings suggest that 1.5 mg/kg bwt may produce adequate clinical effects, and the dosing interval should be 12–24 h depending on condition severity. However, at that dose, the concentration in the animal exceeds thein vitroIC50for both isoforms, so that COX‐1/COX‐2 selectivity is lost and side‐effects due to COX‐1 inhibition are a possibility. Nimesulide should therefore be used with caution in equine clinical practice.
The effect of uterine torsion on mare and foal survival: a retrospective study, 1985–2005
Authors: CHANEY K. P. , HOLCOMBE S. J. , LEBLANC M. M. , HAUPTMAN J. G. , EMBERTSON R. M. , MUELLER P. O. E. , BEARD W. L.
Published: March 2007

Reasons for performing study: Anecdotal speculation suggests that prognosis for survival of mares and foals following correction of uterine torsion has improved over the past 30 years.

Objectives: To determine statistically the outcome of uterine torsion according to duration of clinical signs, stage of gestation, parity, physical examination findings, method of correction, prognosis for survival and reproductive health of the mare, and prospects for the foal within the neonatal period.

Methods: This retrospective study combined cases from 4 equine referral hospitals.

Results: The stage of gestation at which uterine torsion occurred was a risk factor for survival of mare and foal. Overall mare survival was 53/63 (84%); when uterine torsion occurred at <320 days gestation, 36/37 (97%) of mares survived compared to 17/26 (65%) survival rate when uterine torsion occurred at ≥320 days gestation. Overall foal survival was 54% (29/54). When uterine torsion occurred at <320 days gestation, 21/29 (72%) foals survived compared to 8/25 (32%) when uterine torsion occurred at ≥320 days gestation. Thirty mares were discharged from the hospital carrying a viable fetus following uterine torsion correction and 25/30 (83%) of these mares delivered live foals that survived beyond the neonatal period.

Conclusions: Prognosis for survival for mares and foals following uterine torsion is good and improves if torsion occurs <320 days compared to ≥320 days gestation.

Clinical relevance: Gestational timing of uterine torsion should be considered when advising clients about the prognosis for survival of the mare and foal. The prognosis for a mare delivering a live foal is good if the mare is discharged from the hospital following uterine torsion correction with a viable fetus.
Mesenchymal stem cell therapy in equine musculoskeletal disease: scientific fact or clinical fiction?
Authors: TAYLOR S. E. , SMITH R. K. W. , CLEGG P. D.
Published: March 2007

The goal in the therapeutic use of mesenchymal stem cells (MSCs) in musculoskeletal disease is to harness the regenerative nature of these cells focussing on their potential to grow new tissues and organs to replace damaged or diseased tissue. Laboratory isolation of MSCs is now well established and has recently been demonstrated for equine MSCs. Stem cell science has attracted considerable interest in both the scientific and clinical communities because of its potential to regenerate tissues. Research into the use of MSCs in tissue regeneration in general reflects human medical needs, however, the nature, prevalence and prognosis of superficial digital flexor tendonitis has put equine veterinary science at the forefront of tendon regeneration research. Much has been investigated and learnt but it must be appreciated that in spite of this, the field is still relatively young and both communities must prepare themselves for considerable time and effort to develop the technology into a highly efficient treatments. The promise of functional tissue engineering to replace old parts with new fully justifies the interest. At present, however, it is important to balance the understanding of our current limitations with a desire to progress the technology.
Formation of poly‐vinyl‐alcohol structures by supercritical CO2
Authors: Reverchon E. , Cardea S. , Rapuano C.
Published: March 2007

Poly‐vinyl‐alcohol (PVA) porous structures have been prepared using a supercritical phase inversion process in which supercritical carbon dioxide (SC‐CO2) acts as the nonsolvent. First, we tested the versatility of the SC‐CO2 phase inversion process, forming PVA/dimethylsulfoxide (DMSO) solutions with polymer concentrations ranging from 1 to 35% (w/w) and changing the process parameters. We worked at temperatures from 35 to 55°C and pressures from 100 to 200 bar obtaining different membranes morphologies: dense films, membranes with coexisting morphologies, and microparticles. However, we did not produce symmetric or asymmetric porous membranes. To obtain this result, we used casting solutions formed by adding acetone to DMSO with the aim of modifying the affinity between SC‐CO2 and the liquid solvent. In this series of experiments, we obtained asymmetric membranes with skin layer thicknesses lower than 10 μm. The results obtained in this work have been explained considering that the membranes formation mechanism is related to the kinetics of the process; i.e. the affinity between the solvent (mixture of solvents) and SC‐CO2. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Neue Erkenntnisse zum Verformungsverhalten des Frankfurter Tons
Authors: Dürrwang Rudolf , El‐Mossallamy Yasser , Reininger‐Behrenroth Maik
Published: March 2007

Anhand des Bauvorhabens “Opernturm” von Tishman Speyer auf dem ehemaligen Gelände der Zürichversicherung “Zürichhaus” an der Alten Oper im Zentrum von Frankfurt am Main wird dargestellt, daß der Effekt der Entlastung/Wiederbelastung ausschließlich zeitabhängig ist. Dies wurde möglich, da erstmals in Frankfurt nach dem Abbruch der alten Zürichhäuser sechs Jahre vergingen, bis mit dem Neubau begonnen wurde. In diesem Zeitraum wurden die Hebungen der alten Gründung (Bestandskeller) und der Nachbarn (u.a. U‐Bahn) als Teil des Beweissicherungsverfahrens beobachtet. Weiterhin werden die Ergebnisse von Cross‐hole‐Messungen zur Bestimmung der dynamischen Baugrundsteifigkeit des Frankfurter Baugrunds dargestellt und diskutiert.
Enantioseparation and determination of 2,2‐dimethylcyclopropanecarboxamide and corresponding acid in the bioconversion broth by gas chromatography
Authors: Zheng Ren‐Chao , Zheng Yu‐Guo , Shen Yin‐Chu
Published: March 2007

A simple and sensitive method employing gas chromatography was developed for the enantioseparation and determination of 2,2‐dimethylcyclopropanecarboxamide and its acid in the bioconversion broth. Samples were recovered in high yield by extracting the broth with equal volumes of ethyl acetate twice. Separation of the four enantiomers was performed on a gamma‐cyclodextrin based chiral column BGB‐175. The effect of column flow rate and temperature on the retention and resolution of the enantiomers was investigated. The proposed method exhibited good linearity, repeatability and precision, and was successfully used to monitor and control the bioconversion process of 2,2‐dimethylcyclopropanecarboxamide. Copyright © 2007 John Wiley & Sons, Ltd.
Study on Electrochemical Copolymerization of Aniline and 3‐Methylthiophene in HMIMBF4 Ionic Liquid and Its Properties
Authors: Zhang Ai‐Jian , Zhang Gui‐Rong , Yang Guang‐Da , Ao Feng‐Guo , Lu Jia‐Xing
Published: March 2007

Electrochemical polymerization of aniline and 3‐methylthiophene has been accomplished in 1‐methylimidazium tetrafluoroborate (HMIMBF4) ionic liquid. Homopolymer and copolymers of aniline and 3‐methylthiophene were obtained successfully. The copolymer was studied by cyclic voltammetry and electrochemical impedance spectroscopy. The formation of copolymer has been confirmed by FT‐IR and UV spectra. The atomic force microscope (AFM) was used for microstructural analysis. Both the homopolymer and the copolymer had the catalytic activity for the hydroquinone.
Low‐Temperature Heat Capacities and Thermodynamic Properties of Hydrated Nickel L‐Threonate Ni(C4H7O5)2·2H2O(s)
Authors: Di You‐Ying , Xiao Qin , Tan Zhi‐Cheng , Gao Sheng‐Li , Chen San‐Ping , Sun Li‐Xian
Published: March 2007

Low‐temperature heat capacities of the compound Ni(C4H7O5)2·2H2O(s) have been measured with an automated adiabatic calorimeter. A thermal decomposition or dehydration occurred in 350–369 K. The temperature, the enthalpy and entropy of the dehydration were determined to be (368.141±0.095) K, (18.809±0.088) kJ·mol−1 and (51.093±0.239) J·K−1·mol−1 respertively. The experimental values of the molar heat capacities in the temperature regions of 78–350 and 368–390 K were fitted to two polynomial equations of heat capacities (Cp,m) with the reduced temperatures (X), [X = f (T)], by a least squares method, respectively. The smoothed molar heat capacities and thermodynamic functions of the compound were calculated on the basis of the fitted polynomials. The smoothed values of the molar heat capacities and fundamental thermodynamic functions of the sample relative to the standard reference temperature 298.15 K were tabulated with an interval of 5 K.
Determination of Inorganic Arsenic Species by Electrochemical Hydride Generation Atomic Absorption Spectrometry with Selective Electrochemical Reduction
Authors: Li Xun , Wang Zheng‐Hao
Published: March 2007

A new direct procedure for the determination of inorganic arsenic species was developed by electrochemical hydride generation atomic absorption spectrometry (EcHG‐AAS) with selective electrochemical reduction. The determination of inorganic arsenic species is based on the fact that As(III) shows significantly higher absorbance at low electrolytic currents than As(V) in 0.3 mol·L−1 H2SO4. The electrolytic current used for the determination of As(III) without considerable interferences of As(V) was 0.4 A, whereas the current for the determination of As(III) and As(V) was 1.2 A. For equal concentrations of As(III) and As(V) in a sample, the interferences of As(V) during the As(III) determination were smaller than 5%. The absorbance for As(V) could be calculated by subtracting that for As(III) measured at 0.4 A from the total absorbance for As(III) and As(V) measured at 1.2 A, and then the concentration of As(V) can be obtained by its calibration curve at 1.2 A. The methodology developed provided the detection limits of 0.3 and 0.6 ng·mL−1 for As(III) and As(V), respectively. The relative standard deviations were of 3.5% for 20 ng·mL−1 As(III) and 3.2% for 20 ng·mL−1 As(V). The method was successfully applied to determination of soluble inorganic arsenic species in Chinese medicine.
New Copper(II) and Nickel(II) Complexes of 4‐Morpholinoaceto‐ phenone Thiosemicarbazone: Structural, Electrochemical and Antimicrobial Studies
Authors: Bingol Haluk , Coskun Ahmet , Akgemci Emine Guler , Kaya Basturk , Atalay Tevfik
Published: March 2007

4‐Morpholinoacetophenone thiosemicarbazone, MAPT, and its nickel(II) and copper(II) complexes have been prepared and characterized by elemental analysis, magnetic susceptibility, spectral methods (FT‐IR, 1H NMR) and cyclic voltammetry. Electrochemical behaviors of the complexes have been studied by cyclic voltammetry in DMF media showing metal centered reduction processes for both of them. The redox properties, nature of the electrode processes and the stability of the complexes were discussed. [Cu(MAPT)2]Cl2 complex shows Cu(II)/Cu(I) couple and quasi‐reversible wave associated with the Cu(III)/Cu(II) process. The reduction/oxidation potential values depend on the structures of complexes. Also, the antimicrobial activities of these complexes were determined against S. aureus, E. coli and B. subtilis.
Selective Synthesis of [2+2] Macrocyclic Schiff Bases from Chiral 1,4‐Diamines
Authors: Zhu Hai‐Bin , Hu Da‐Hua , Dong Hua‐Ze , Li Gen‐Xi , Gou Shao‐Hua
Published: March 2007

[2+2] macrocyclic Schiff bases of three kinds have been synthesized from chiral 1,4‐diamines by use of different methods. Macrocyclic Schiff bases 1a–1c have been selectively obtained based on a non‐templated dilution method from chiral 1,4‐diamines a–c and dialdehyde DA1, whereas macrocycles 2a–2c have been selectively produced from reaction of diamines a–c and dialdehyde DA2 in the presence of boric acid as templates. Macrocyclic Schiff bases 3a–3c have been afforded in high selectivity from diamines a–c and dialdehyde DA3 by means of sodium‐template. All the titled compounds have been confirmed by 1H NMR and ESI‐MS analyses.
Studies on Aggregation Interaction between Reduced‐Denatured Egg White Lysozymes during Refolding Procedure in Urea Solution
Authors: Bian Liu‐Jiao , Liang Chang‐Li , Yang Xiao‐Yan , Liu Li
Published: March 2007

The aggregation interaction between reduced‐denatured egg white lysozymes during refolding procedure in urea solution was studied by means of reducing and non‐reducing protein electrophoreses. Results of non‐reducing sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS‐PAGE) of the supernatant and aggregate precipitate formed in refolding process show that except being refolded to native egg white lysozymes, the reduced‐denatured lysozymes can also form the aggregates with molecular weights (MW) being separately about 30.0 and 35.0 kD, while the reducing SDS‐PAGE and the refolding results in the presence of sodium dodecyl sulphate show that these aggregates are formed chiefly through the misconnection of disulfide bonds between the reduced‐denatured lysozymes, and the aggregate precipitates are formed through the non‐covalent interactions between the aggregates with molecular weight being about 30.0 kD. From the results of electrophoresis and size‐exclusion chromatographic analyses, it can be inferred that the aggregates with molecular weights being about 30.0 and 35.0 kD are bi‐molecular and tri‐molecular egg white lysozyme aggregates, respectively. And finally, a suggested refolding mechanism of reduced‐denatured egg white lysozymes in urea solution was presented.
Homopolymerization and Copolymerization of Adipic Anhydride with ε‐Caprolactone Catalyzed by Rare Earth Trisphenolate
Authors: Chen Feng , Zhu Wei‐Pu , Shen Zhi‐Quan
Published: March 2007

The ring‐opening polymerization of adipic anhydride and the ring‐opening copolymerization of adipic anhydride with ϵ‐caprolactone catalyzed by single component rare earth trisphenolate have been reported. The structure of the copolymer poly(CL‐b‐AA) has been characterized by SEC, 1H NMR and DSC.
A New Approach to C60‐Contanining Polyphosphazenes by Polymerization of Phosphonitrile Chloride Trimer in the Presence of C60
Authors: Li Zhen , Zeng Qi , Zhu Zhi‐Chao , Li Qian‐Qian , Li Zhong‐An , Qin Jin‐Gui
Published: March 2007

A novel synthetic strategy was developed to prepare polyphosphazenes containing C60 moieties. Thus, the phosphonitrile chloride trimer underwent thermal ring‐opening polymerization (ROP) in the presence of C60 molecules to yield the reactive macromolecular intermediate, C60‐containing poly(dichlorophosphazene). And then, the other groups could be linked to the phosphazene backbone by nucleophilic substitution reaction of the chlorine atoms in this intermediate to produce a series of C60‐containing polyphosphazene. The polymer exhibits good solubility in common organic solvents and is thermally stable.
Amide‐Exchange‐Rate‐Edited NMR (AERE‐NMR) Experiment: A Novel Method for Resolving Overlapping Resonances
Authors: Liu Xue‐Hu , Lin Dong‐Hai
Published: March 2007

This paper describes an amide‐exchange‐rate‐edited (AERE) NMR method that can effectively alleviate the problem of resonance overlap for proteins and peptides. This method exploits the diversity of amide proton exchange rates and consists of two complementary experiments: (1) SEA (solvent exposed amide)‐type NMR experiments to map exchangeable surface residues whose amides are not involved in hydrogen bonding, and (2) presat‐type NMR experiments to map solvent inaccessibly buried residues or nonexchangeable residues located in hydrogen‐bonded secondary structures with properly controlled saturation transfer via amide proton exchanges with the solvent. This method separates overlapping resonances in a spectrum into two complementary spectra. The AERE‐NMR method was demonstrated with a sample of 15N/13C/2H(70%) labeled ribosome‐inactivating protein trichosanthin of 247 residues.
NMR Spectral Analysis and Modelling I. Basic Concepts and Fourier Transforms
Authors: Ziessow Dieter
Published: March 2007

Essentially all high‐resolution NMR experiments are now carried out with pulse excitation. Basic concepts, such as signal induction and sense of rotation, are discussed using a rotating magnetic needle as an analogy. The typical signal, recorded immediately after the r.f. pulse is a superposition of many single‐line free‐induction‐decay signals, each of which is described by the expression, Uo, j‐cos(2πvjt +Φj)·dj(t). The frequency, vj, carries structural information and the amplitude Uo, j is proportional to the molecular concentration. The function dj(t) accounts for the decay, and the phase Φj depends on instrumental parameters and the mode of observation. It is the purpose of spectral analysis to determine these parameters from the measured composite signal. Fourier analysis, the most prominent approach, is introduced in a graphical and analytical manner based on the concept of complex harmonic waves exp(i2πvt). To facilitate understanding, the reverse process, namely Fourier synthesis, as well as the number e and its complex powers eix, are introduced in an elementary way. Part I concludes with a discussion of: a) the relationship between the attainable spectral resolution and its time length of signal observation, and b) the difference between the actual and predicted time signals within and outside the observation‐time window.
Phase‐Sensitive Detection. Part II: Quadrature Phase Detection
Authors: D. Traficante Daniel
Published: March 2007

The problems associated with the use of a single phase‐sensitive detector (PSD) in an NMR receiver are reviewed. These problems can be eliminated by the use of two PSDs, arranged in parallel. The references to the PSDs are derived from a single source, but one is phase‐shifted by 90° with respect to the other. This arrangement is called quadrature phase detection (QPD). The free‐induction decays (FIDs) obtained as outputs from the two PSDs are phase‐shifted by 90° with respect to one another, and are referred to as a “real” and an “imaginary” FID. The PSDs and the electronic components associated with them, including amplifiers and filters, are called the “real” and the “imaginary” channels. The FIDs from these channels can be processed so that the problems associated with the use of a single PSD are eliminated. In practice, however, a different set of problems emerges with the use of a QPD system because it is not possible to balance the two channels exactly. A procedure called CYCLOPS, which phase‐cycles both the transmitter and the receiver portion of the computer, can be used to overcome these difficulties.
Combined Rotation and Multiple Pulse Spectroscopy (CRAMPS)
Authors: P. Burum Douglas
Published: March 2007

The combined rotation and multiple pulse spectroscopy (CRAMPS) experiment is discussed from a practical point of view. Emphasis is given to the understanding of fundamental concepts and practical methods for obtaining optimum results. After a discussion of the basic theoretical concepts of coherent‐averaging theory, the effects of rf pulse errors are discussed. A detailed discussion of spectrometer hardware emphasizes features critical to the success of CRAMPS. A step‐by‐step procedure for spectrometer adjustment in preparation for CRAMPS is outlined. Finally, there is an overview of more sophisticated one‐ and two‐dimensional NMR experiments that incorporate CRAMPS.
Study of a stabilized mixed finite element with emphasis on its numerical performance for strain localization problems
Authors: Sánchez P. J. , Sonzogni V. E. , Huespe A. E.
Published: March 2007

The numerical performance of a stabilized mixed finite‐element formulation based on the pressure‐gradient‐projection method (PGP) using equal‐order (linear) interpolation is evaluated by solving solid mechanics problems, such as structural limit load determination and strain localization modelling. All of them present incompressibility kinematical constraints induced by the constitutive behaviour. This work is specially devised to obtain critical conclusions about the use of PGP model when the mechanical response is governed by strain‐softening macroscopic mechanisms. In this context, we report some detected limitations in the present formulation due to the existence of pathological mesh bias dependence once the strain localization process becomes dominant, and linear kinematics is used. An additional contribution is the numerical comparative analysis of two different strategies, for solving the complete linear equation system, addressed to a finite‐element parallel code. The numerical results are compared with the standard Galerkin formulation and with an alternative stabilized mixed finite‐element procedure (pressure stabilizing Petrov–Galerkin scheme). Copyright © 2007 John Wiley & Sons, Ltd.
Applications of three‐dimensional finite‐difference seismic modeling in oil field exploitation and simulation
Authors: Mufti Irshad R. , Fou Joseph T.
Published: March 2007

Two‐dimensional finite‐difference seismic models are excited by a line‐source which leads to incorrect amplitudes. Moreover, in a structurally complex environment with strong three‐dimensional (3‐D) features, the results obtained from such models are often incorrect and do not include any out‐of‐plane events. On the other hand, 3‐D models based on the ray‐theory approximation fail to provide vital information such as diffractions and interference patterns which can strongly influence the seismic expression associated with hydrocarbon reservoirs. We present the results of a study in which an approximate version of mapped surfaces was used to carry out a synthetic 3‐D finite‐difference survey. This followed the necessary adjustment of various horizons and it involved the calibration of synthetic sections by comparing them with the corresponding unmigrated real‐data sections. The simulation of reservoir characteristics was accomplished in reference to two key seismic horizons used in the model.
Terrain analysis from curvature profiles
Authors: Goldgof Dmitry B. , Huang Thomas S. , Lee Hua
Published: March 2007

This paper describes a new algorithm which uses Gaussian and mean curvature values of the terrain surface to extract feature points. These points are then used for recognition of particular subregions of the terrain and in estimating relative positions of these subregions in the terrain. The Gaussian and mean curvatures are chosen because they are invariant under rotation and translation. In the Gaussian and mean curvature images, the points of maximum and minimum curvatures are extracted and used for matching. The stability of the position of these points in the presence of noise and with resampling is investigated. The input for this algorithm is 3D digital terrain data. Curvature values are calculated from the data by fitting a quadratic surface over a square window and calculating directional derivatives of this surface. A method of surface fitting that is invariant to sensor‐centered coordinate system transformation is suggested and implemented. Real terrain data are used in our experiments. The algorithm is tested with and without the presence of noise, and its performance is described.
Visual language and software development environment for image processing
Authors: Rasure John , Argiro Danielle , Sauer Tom , Williams Carla
Published: March 2007

The Khoros system integrates multiple user interface modes, code generators, instructional aids, data visualization, and information processing to produce a comprehensive image processing research tool. This system can easily be tailored to other application domains because the tools of the system can modify themselves as well as the system. This attribute is important in a system that is designed to be extensible and portable. The Khoros infrastructure consists of three major components: a high‐level user interface specification, methods of software development embedded in a code generation tool set, and an interoperable data exchange format and algorithm library. These basic facilities have been used to build a set of applications for performing image processing research, algorithm development, and data visualization. One of the most powerful features of the system is its high‐level abstract visual language. Khoros is a successful demonstration of how development programming, end‐user applications programming, information processing, data display, instruction, documentation, and maintenance can be integrated to build a state‐of‐the‐art image/data processing and visualization software environment.
Aspect graphs: An introduction and survey of recent results
Authors: Bowyer Kevin W. , Dyer Charles R.
Published: March 2007

The study of the aspect graph of a three‐dimensional object has recently become an active area of research in computer vision. The aspect graph provides a complete enumeration of all possible distinct views of an object, given a model for viewpoint space and a definition for “distinct.” This article presents a tutorial introduction to the aspect graph, surveys the current state of the art in algorithms for automatically constructing aspect graphs, and describes some possible applications of aspect graphs in computer vision and computer graphics.