bluuebunny/crossref_metadata_2025_split huggingface dataset:
Haemodynamic effect of intermittent pneumatic compression of the leg after infrainguinal arterial bypass grafting
Authors: Delis K T , Husmann M J , Szendro G , Peters N S , Wolfe J H N , Mansfield A O 
Published: March 2004

Abstract

Background
Intermittent pneumatic compression (IPC) may increase blood flow through infrainguinal arterial grafts, and has potential clinical application as blood flow velocity attenuation often precedes graft failure. The present study examined the immediate effects of IPC applied to the foot (IPCfoot), the calf (IPCcalf) and to both simultaneously (IPCfoot+calf) on the haemodynamics of infrainguinal bypass grafts.

Methods
Eighteen femoropopliteal and 18 femorodistal autologous vein grafts were studied; all had a resting ankle : brachial pressure index of 0·9 or more. Clinical examination, graft surveillance and measurement of graft haemodynamics were conducted at rest and within 5 s of IPC in each mode using duplex imaging. Outcome measures included peak systolic (PSV), mean (MV) and end diastolic (EDV) velocities, pulsatility index (PI) and volume flow in the graft.

Results
All IPC modes significantly enhanced MV, PSV, EDV and volume flow in both graft types; IPCfoot+calf was the most effective. IPCfoot+calf enhanced median volume flow, MV and PSV in femoropopliteal grafts by 182, 236 and 49 per cent, respectively, and attenuated PI by 61 per cent. Enhancement in femorodistal grafts was 273, 179 and 53 per cent respectively, and PI attenuation was 63 per cent.

Conclusion
IPC was effective in improving infrainguinal graft flow velocity, probably by reducing peripheral resistance. IPC has the potential to reduce the risk of bypass graft thrombosis.
Validation of POSSUM scoring systems for audit of major hepatectomy
Authors: Lam C-M , Fan S-T , Yuen A W-C , Law W-L , Poon K 
Published: March 2004

Abstract

Background
The aim of the study was to validate the use of Physiological and Operative Severity Score in the enUmeration of Mortality and morbidity (POSSUM) and Portsmouth (P) POSSUM scoring systems to predict postoperative mortality in a group of Chinese patients who had a major hepatectomy for hepatocellular carcinoma.

Methods
A retrospective analysis was performed on data collected prospectively over a 6-year interval from January 1997 to December 2002. The mortality risks were calculated using both the POSSUM and the P-POSSUM equations.

Results
Two hundred and fifty-nine patients underwent major hepatectomy; there were 17 (6·6 per cent) postoperative deaths. Of 32 preoperative and intraoperative variables studied, age, smoking habit, serum creatinine concentration, American Society of Anesthesiologists grade, and physiological and operative severity scores were found to be significant factors predicting mortality. On multivariate analysis only the physiological and operative severity scores were independent variables. The POSSUM system overpredicted mortality risk (14·2 per cent) and there was a significant lack of fit in these patients (χ2 = 14·1, 3 d.f., P = 0·003). The mortality rate predicted by P-POSSUM was 4·2 per cent and showed no significant lack of fit (χ2 = 7·6, 3 d.f., P = 0·055), indicating that it predicted outcome effectively. A new logistic equation was derived from the present patient data set that requires testing prospectively.

Conclusion
P-POSSUM significantly predicted outcome in Chinese patients who had major hepatectomy for hepatocellular carcinoma. A modified disease-specific equation requires further testing.
Development of solid‐phase extraction method and its application for determination of hydrochlorothiazide in human plasma using HPLC
Authors: Zendelovska Dragica , Staﬁlov Trajče , Miloševski Petar 
Published: March 2004

AbstractA high‐performance liquid chromatographic method was developed, validated and applied for the determination of hydrochlorothiazide in human plasma. The effects of mobile phase composition, buffer concentration, mobile phase pH and concentration of organic modiﬁers on retention of hydrochlorothiazide and internal standard were investigated. The method involves solid‐phase extraction on RP‐select B cartridges followed by isocratic reversed‐phase chromatography on a Hibar Lichrospher 100 RP‐8 column with UV detection at 230 nm. The recovery, selectivity, linearity, precision and accuracy of the method were evaluated from spiked human plasma samples. Limit of quantiﬁcation was 10 ng mL−1. The method has been implemented to monitor hydrochlorothiazide levels in patient samples. Copyright © 2004 John Wiley & Sons, Ltd.
Rapid analysis of MMI270B, an inhibitor of matrix metalloproteases in human plasma by liquid chromatography–tandem mass spectrometry: matrix interference in patient samples
Authors: Majumdar Tapan K. , Vedananda Sunanda , Tse Francis L. S. 
Published: March 2004

AbstractA high‐throughput method was developed and validated for the quantitative determination of MMI270B, an inhibitor of matrix metalloprotease (MMP) enzymes, in human plasma. The method was based on reverse‐phase chromatographic separation of the analyte from plasma extract followed by atmospheric pressure chemical ionization (APCI) and tandem mass spectrometry in the selected reaction monitoring mode (SRM). Extraction was performed using simple protein ﬁltration in the 96‐well plate format to increase the throughput of the method. Optimised chromatographic separation in a short column (30 × 4.6 mm i.d.) coupled with positive APCI mode of ionization followed by selective SRM mode of detection yielded clean chromatograms with minimal signal suppression. The chromatographic conditions resolved isobaric interference peaks observed in samples from patients dosed with MMI270B. The standard curve was linear (r = 0.997) within the concentration range of 1.04 (lower limit of quantiﬁcation) to 1040 ng/mL using 0.1 mL of human plasma. The accuracy of the method varied from 93.6 to 103% with a precision of 2.17–6.71% over the concentration range. The method was simple, rapid, and robust with an analyte recovery of >98%. Copyright © 2003 John Wiley & Sons, Ltd.
Liquid chromatography‐tandem mass spectrometry for the determination of a new oxazolidinone antibiotic DA‐7867 in human plasma
Authors: Ji Hye Young , Lee Hye Won , Chang Seung Goo , Lee Jong Jin , Rhee Jae Keol , Kim Won Bae , Lee Hye Suk 
Published: March 2004

AbstractA liquid chromatography‐tandem mass spectrometric (LC/MS/MS) method for the determination of a new ox‐azolidinone antibiotic DA‐7867, (S)‐[N‐3‐(4‐(2‐(1‐methyl‐5‐tetrazolyl)‐pyridine‐5‐yl)‐3‐ﬂuorophenyl)‐2‐oxo‐5‐oxazolidinyl]methyl acetamide, in human plasma was developed. DA‐7867 and internal standard, linezolid, were extracted from human plasma with ethyl acetate at acidic pH. A reverse‐phase LC separation was performed on Luna C8 column with the mixture of acetonitrile–ammonium formate (10 mm, pH 4.5; 35:65, v/v) as mobile phase. The analytes were determined using an electrospray ionization tandem mass spectrometry in the multiple‐reaction‐monitoring mode. The lower limits of quantiﬁcation for DA‐7867 was 2.5 ng/mL. The single liquid–liquid extraction quantitatively recovered DA‐7867 and internal standard from plasma samples at the ranges of 82.2–86.7%. DA‐7867 was stable in blank human plasma at room temperature for 24 h and following three freeze–thaw cycles. Copyright © 2003 John Wiley & Sons, Ltd.
Determination of the uronic acid composition of seaweed dietary ﬁbre by HPLC
Authors: Sánchez‐Machado D. I. , López‐Cervantes J. , López‐Hernández J. , Paseiro‐Losada P. , Simal‐Lozano J. 
Published: March 2004

AbstractA high‐performance liquid chromatographic (HPLC) method is described for determination of the ratio of β‐d‐mannuronic acid to α‐l‐guluronic acid (M/G ratio) in dietary ﬁbre of edible seaweeds. Total dietary ﬁbre (TDF) content was determined gravimetrically. The TDF fraction was hydrolysed with 12 m and 1 m H2SO4, then neutralized with AG 4 × 4 resin. The uronic acids were separated in a Tracer Extrasil SAX 5 µm column (25 cm × 4 mm) at 35°C, with 2 mm KH2PO4 containing 5% methanol as mobile phase at a ﬂow rate of 1.5 mL/min. The detection wavelength was UV 210 nm. The chromatographic identiﬁcations of β‐d‐mannuronic acid and α‐l‐guluronic acid were conﬁrmed by liquid chromatography–mass spectrometry (LC‐MS). The method precision was 1.4% for β‐d‐mannuronic acid and 3.5% for α‐l‐guluronic acid. The method was used to determine M/G ratio in canned seaweeds (Saccorhiza polyschides and Himanthalia elongata) and in dried seaweeds (H. elongata, Laminaria ochroleuca, Undaria pinnatiﬁda, Palmaria sp. and Porphyra sp.). Copyright © 2003 John Wiley & Sons, Ltd.
Determination of abamectin and doramectin in sheep faeces using HPLC with ﬂuorescence detection
Authors: Kolar Lucija , Kužner Jernej , Eržen Nevenka Kožuh 
Published: March 2004

AbstractAn analytical procedure for the determination of abamectin and/or doramectin in sheep faeces has been developed. Avermectins were extracted from sheep faeces with acetonitrile, clean‐up using solid phase extraction (SPE) and analysed by high performance liquid chromatography (HPLC) with ﬂuorescence detection after derivatization with N‐methylimidazole.The method has a low detection limit (1.0 ng/g of moist sheep faeces), low quantiﬁcation limit (2.5 ng/g of moist sheep faeces), good recovery in the range 66.4–80.8% for abamectin and 67.7–85.5% for doramectin as well as good repeatability (>85%). The method is applicable to the study of the time proﬁle of excretion in sheep faeces and also for ecotoxicological studies of both avermectins. Copyright © 2003 John Wiley & Sons, Ltd.
Simultaneous determination of amphetamine derivatives in human urine after SPE extraction and HPLC‐UV analysis
Authors: Soares M. E. , Carvalho M. , Carmo H. , Remião F. , Carvalho F. , Bastos M. L. 
Published: March 2004

AbstractAmphetamine derivatives are a class of compounds increasingly abused as recreational drugs in various regions of the world. Although d‐amphetamine (AMPH) and 3,4‐methylenedioxymethamphetamine (MDMA, ecstasy) are among the most commonly used, the abuse of other designer drugs such as 4‐bromo‐2,5‐dimethoxyphenethylamine (2C‐B) and 4‐methylthioamphetamine (4‐MTA) and their involvement in acute intoxications has been increasingly reported. There is evidence that abusers ingest these compounds either alone or in combination and the respective monitoring is important for both legal and health care purposes in hospital emergency. In the present study a simple and clean solid‐phase extraction procedure from urine of AMPH and MDMA, and their major metabolites p‐hydroxyamphetamine (OH‐AMPH) and methylenedioxyamphetamine (MDA) and 2C‐B and 4‐MTA was developed. Analysis was performed by HPLC‐UV and the precision of the technique was between 2.9 and 5.3% for all compounds. For the overall procedure, the precision values were between 3.3 and 5.9%. Recoveries obtained from spiked urines at three concentration levels were better than 84 ± 4% for the six compounds. The limit of detection of the method for the compounds (between 5.3 and 84.0 ng) enables their identiﬁcation in urine after ingestion of fatal and non‐fatal doses. The main advantages of the present method lie in its simple, clean and reliable SPE extraction method of the six amphetamine derivatives from urine followed by their simultaneous detection and quantiﬁcation by liquid chromatography with UV detection. Copyright © 2004 John Wiley & Sons, Ltd.
Biodegradation and bioaccumulation of fenitrothion in rat liver
Authors: Roy Shalini , Roy Sharmila , Kumar Reena , Sharma C. B. , Pereira Ben. J. 
Published: March 2004

AbstractThe biodegradation of fenitrothion O,O‐dimethyl‐O‐(3‐methyl‐4‐nitro phenyl) phosphorothioate was investigated in rat liver after administration of various doses (5 mg/100 g body weight and 20 mg/100 g body weight) in acute treatment and 1 mg/100 g body weight in chronic treatment. High performance liquid chromatography of the pesticide and its metabolites formed in liver in acute treatment showed time‐dependent sequential conversion of pesticide into three major metabolites within 24 h. These metabolites were separated and puriﬁed to homogenity by HPLC and characterized by IR spectroscopy as O,O‐dimethyl‐O‐(3‐methyl‐4‐amino phenyl) phsophorothioate (metabolite 1), O,O‐dimethyl phosphorothioate (metabolite II) and O,O‐dimethyl phosphate (metabolite III) in the ﬁrst dose (5 mg/100 g body weight). Metabolite II was found to be different in the second dose (20 mg/100 g body weight) and identiﬁed as O,O‐dimethyl O‐3‐methyl‐4‐amino phenyl phosphate. The results with the ﬁrst dose indicated reduction of the nitro group in fenitrothion as step I followed by hydrolytic clevage of the P‐O‐aryl bond in metabolite I and oxidative desulphurylation of metabolite II. At higher dose (20 mg/100 g body weight) oxidative desulphurylation takes place as step II followed by hydrolysis of metabolite II. The bioaccumulation of fenitrothion within 60 days during chronic treatment showed no metabolite but continuous reduction in fenitrothion concentration, indicating excretion of pesticide and its products in urine and in faeces. Copyright © 2004 John Wiley & Sons, Ltd.
Detailed anatomy of the abdomen and pelvis of the visible human female
Authors: Bajka M. , Manestar M. , Hug J. , Székely G. , Haller U. , Groscurth P. 
Published: March 2004

AbstractWe report on a virtual anatomical preparation of the abdomen and pelvis of the Visible Human Female (VHF) for laparoscopic surgery training. The detailed cross‐sectional image data set from the U.S. National Library of Medicine was used as the basis to build an exemplary model of the female abdomen and pelvis. Segmentation software was developed to delineate organ outlines and more than 300 structures of interest, including organs, blood vessels, bones, muscles, and ligaments, have been segmented and three‐dimensionally reconstructed. Analyzing the normal anatomy we found several variations and pathologies of the VHF, such as missing muscles (gemellus superior, psoas minor), additional veins as well as spondylophytes (vertebral column, pubic bone), and colon diverticula. The complete data set may be viewed on the home page of the project (http://www.vision.ee.ethz.ch/projects/Lasso/start.html). Clin. Anat. 17:252–260, 2004. © 2004 Wiley‐Liss, Inc.
New views of male pelvic anatomy: Role of computer‐generated 3D images1
Authors: Venuti Judith M. , Imielinska Celina , Molholt Pat 
Published: March 2004

AbstractThere is considerable controversy concerning the role of cadaveric dissection in teaching gross anatomy and the potential of using 3D computer‐generated images to substitute for actual laboratory dissections. There are currently few high‐quality 3D virtual models of anatomy available to evaluate the utility of computer‐generated images. Existing 3D models are frequently of structures that are easily examined in three dimensions by removal from the cadaver, i.e., the heart, skull, and brain. We have focused on developing a 3D model of the pelvis, a region that is conceptually difficult and relatively inaccessible for student dissection. We feel students will benefit tremendously from 3D views of the pelvic anatomy. We generated 3D models of the male pelvic anatomy from hand‐segmented color Visible Human Male cryosection data, reconstructed and visualized by Columbia University's in‐house 3D Vesalius™ Visualizer.1 These 3D models depict the anatomy of the region in a realistic true‐to‐life color and texture. They can be used to create 3D anatomical scenes, with arbitrary complexity, where the component anatomical structures are displayed in correct 3D anatomical relationships. Moreover, a sequence of 3D scenes can be defined to simulate actual dissection. Structures can be added in a layered sequence from the bony framework to build from the “inside‐out” or disassembled much like a true laboratory dissection from the “outside‐in.” These 3D reconstructed anatomical models can provide views of the structures from new perspectives and have the potential to improve understanding of the anatomical relationships of the pelvic region (http://www.cellbiology.lsuhsc.edu/People/Faculty/Venuti_Figures/movie_index.html). Clin. Anat. 17:261–271, 2004. © 2004 Wiley‐Liss, Inc.
Non‐parametric statistical methods for multivariate calibration model selection and comparison
Authors: Thomas Edward V. 
Published: March 2004

AbstractModel selection is an important issue when constructing multivariate calibration models using methods based on latent variables (e.g. partial least squares regression and principal component regression). It is important to select an appropriate number of latent variables to build an accurate and precise calibration model. Inclusion of too few latent variables can result in a model that is inaccurate over the complete space of interest. Inclusion of too many latent variables can result in a model that produces noisy predictions through incorporation of low‐order latent variables that have little or no predictive value. Commonly used metrics for selecting the number of latent variables are based on the predicted error sum of squares (PRESS) obtained via cross‐validation. In this paper a new approach for selecting the number of latent variables is proposed. In this new approach the prediction errors of individual observations (obtained from cross‐validation) are compared across models incorporating varying numbers of latent variables. Based on these comparisons, non‐parametric statistical methods are used to select the simplest model (least number of latent variables) that provides prediction quality that is indistinguishable from that provided by more complex models. Unlike methods based on PRESS, this new approach is robust to the effects of anomalous observations. More generally, the same approach can be used to compare the performance of any models that are applied to the same data set where reference values are available. The proposed methodology is illustrated with an industrial example involving the prediction of gasoline octane numbers from near‐infrared spectra. Published in 2004 by John Wiley & Sons, Ltd.
Fault‐tolerant spectroscopic data evaluation based on extended principal component regression correcting for spectral drifts and uncalibrated spectral features
Authors: Vogt F. , Mizaikoff B. 
Published: March 2004

AbstractChemometric algorithms are commonly applied in spectroscopy for deriving concentrations of chemicals from spectra. In order to ensure correct concentration results, the background spectrum must be stable and all absorbers present in unknown samples must have been contained in the calibration set. Recently, standard principal component regression (PCR) has been improved in two ways, correcting either for spectral drifts or for uncalibrated spectral features. In this study a combination of both correction approaches named secured pseudo PCR (spPCR) is presented which provides substantially improved concentration results even if the spectra are simultaneously affected by drifts and uncalibrated features. Additionally, spPCR extracts estimates of the spectrum of the uncalibrated absorbers and the drift spectrum. Hence systematic disturbances can be analyzed and a facile tool for allocating their origin is provided. Copyright © 2004 John Wiley & Sons, Ltd.
Towards Ordered Architectures: Self‐Assembly and Stepwise Procedures to the Hexameric Metallomacrocycles [Arylbis(terpyridinyl)6FeII6−n‐RuIIn] (n=0,2,3,5)
Authors: Newkome George R. , Cho Tae Joon , Moorefield Charles N. , Mohapatra Prabhu P. , Godínez Luis A. 
Published: March 2004

AbstractHexameric metallomacrocycles are a new class of ordered rigid‐macromolecules which possess unique structural, electronic, and physical characteristics. Directed‐ and self‐assembly methods for the construction of these stable bis(terpyridine)‐based materials are investigated by using both FeII and RuII as the coordinating metals. These heterometallomacrocycles and their homocounterparts are structurally compared, and their attendant electrochemical properties are analyzed and evaluated. These studies demonstrate the potential to create stable, nanoscale, doughnut‐shaped, molecular assemblies with envisioned ramifications for energy storage and release, as well as nanoscale molecular electronic and magnetic devices.
Magneto‐Structural Characterization of Metallocene‐Bridged Nitronyl Nitroxide Diradicals by X‐Ray, Magnetic Measurements, Solid‐state NMR Spectroscopy, and Ab Initio Calculations
Authors: Sporer Christian , Heise Henrike , Wurst Klaus , Ruiz‐Molina Daniel , Kopacka Holger , Jaitner Peter , Köhler Frank , Novoa Juan J. , Veciana Jaume 
Published: March 2004

AbstractCrystallization of ferrocene and ruthenocene substituted in the 1‐ and 1′‐positions by two nitronyl nitroxide radicals gave the new crystal phases β‐1 (besides the known phase α‐1), α‐2, and β‐2 whose structures were determined by X‐ray analysis. In β‐1 the radical moieties adopt transoid positions, whereas two different cisoid conformations are adopted by α‐2 and β‐2. These conformations result from inter‐ and intramolecular hydrogen bonds, respectively. All compounds experience antiferromagnetic interactions, and J/kB values up to −7 K have been found by fitting the experimental magnetic susceptibilities to a modified Bleaney–Bowers equation. The solid diradicals α‐1, β‐1, α‐2, and β‐2 as well as the ferrocene 3, which was substituted by a unique nitronyl nitroxide, were investigated by 13C and 1H NMR spectroscopy with magic angle spinning. The carbon signals cover a range of 2000 ppm, and are well resolved such that the structure could be confirmed. Conversion of the signal shifts into spin densities disclosed the mechanisms by which spin delocalization from the nitronyl nitroxide substituents to the metallocene core occurs. The spin density distribution in α‐1, β‐1, and 3 was also predicted by DFT calculations. There is good agreement between the experimental and theoretical trends of the spin delocalization. The magnetic interactions were discussed in the light of intramolecular spin transfer and its dependence on geometric constraints, demonstrating that the 1,1′‐metallocenylene bridge is not a robust magnetic coupler.
DFT Description of the Electronic Structure and Spectromagnetic Properties of Strongly Correlated Electronic Systems: NiII, CuII and ZnIIo‐Dioxolene Complexes
Authors: Bencini Alessandro , Carbonera Chiara , Totti Federico 
Published: March 2004

AbstractThe spectroscopic and magnetic properties of dioxolene complexes of zinc, copper and nickel were studied by DFT calculations on model complexes of formulas [(NH3)4MII(SQ)]+ (M=Zn, Ni; SQ=semiquinonato) and [(NH3)2CuII(SQ)]+. Standard approaches such as time‐dependent DFT (TDDFT), the Slater transition state (STS), and broken symmetry (BS) were found to be unable to completely account for the physical properties of the systems, and complete active space‐configuration interaction (CAS‐CI) calculations based on the Kohn–Sham (KS) orbitals was applied. The CAS‐CI energies, properly corrected with multireference perturbation theory (MR‐PT), were found to be in good agreement with experimental data. We present here a calculation protocol that has a low CPU cost/accuracy ratio and seems to be very promising for interpreting the properties of strongly correlated electronic systems in complexes of real chemical size.