bluuebunny/crossref_metadata_2025_split huggingface dataset:
A finite B‐spline basis set for accurate diatomic molecule calculations
Authors: Artemyev A. N. , Ludeña E. V. , Karasiev V. V. , Hernández A. J. 
Published: December 2003

AbstractA finite basis set particularly adapted for solving the Hartree–Fock equation for diatomic molecules in prolate spheroidal coordinates has been constructed. These basis functions have been devised as products of B‐splines times associated Legendre polynomials. Due to the large number of B‐splines, the resulting set of eigenfunctions is amply distributed over excited states. This gives the possibility of using these basis sets to calculate sums over excited states, appearing in various orders of perturbation theory. As an illustration, the second‐order corrections to the ground‐state energy of some atoms and diatomic molecules with closed electron shells have been calculated. © 2003 Wiley Periodicals, Inc. J Comput Chem 25: 368–374, 2004
Isomers of C20: An energy profile III
Authors: Chavez Jennifer I. , Carrillo Maira M. , Beran Kyle A. 
Published: December 2003

AbstractSemiempirical calculations, at the PM3 level provided within the Winmopac v2.0 software package, are used to geometrically optimize and determine the absolute energies (heats of formation) of a variety of C20 isomers that are predicted to exist in and around the ring and cage isomers. Using the optimized Cartesian coordinates for the ring and the cage isomers, a saddle‐point calculation was performed. The resulting energy profile, consisting of a series of peaks and valleys, is used as a starting point for the identification and location of fifteen additional isomers of C20 that are predicted to be energetically stable, both via geometry optimizations and force constant analysis. These additional isomers were subsequently determined to lie adjacent to one another on the potential surface and establish a step‐wise transformation between the ring and the cage. Transition‐state optimization of the Cartesian coordinates at the saddle point between adjacent isomers was performed to quantify the energy of the transition state. The step‐wise process from one isomer to another, which extends out over the three‐dimensional surface, is predicted to require ∼15% less energy than that of the direct, two‐dimensional transformation predicted in the bowl‐cage profile. However, the net atomic rearrangement for the step‐wise process is about four times greater than that of the direct process. Although less in energy, the amount of atomic rearrangement in the step‐wise process would make the occurrence of such a route prohibitive. Utilizing the direct distance separating the three primary isomers (ring, bowl, cage), the method of triangulation is performed to quantitatively position other C20 structures on the potential surface, relative to the ring, bowl, and cage isomers. © 2003 Wiley Periodicals, Inc. J Comput Chem 25: 322–327, 2004
Second‐order atomic Fukui indices from the electron‐pair density in the framework of the atoms in molecules theory
Authors: Fradera Xavier , Solà Miquel 
Published: December 2003

AbstractAtomic Fukui indices, which are obtained from the electron density, have been previously shown to be useful in predicting which atoms in a molecule are most likely to suffer nucleophilic, electrophilic, or radicalary attacks. Here, we present a second‐order generalization of these indices based on the electron pair density. We show how second‐order atomic Fukui indices can be used to analyze the effects of electron loss or gain in several molecules from an electron pair point of view. Further, these indices also highlight which atoms or pairs of atoms are more likely to suffer nucleophilic, electrophilic, or radical attacks. In conclusion, second‐order indices can complement first‐order ones by affording relevant information on molecular reactivity from an electron pair perspective. © 2003 Wiley Periodicals, Inc. J Comput Chem 25: 439–446, 2004
Biosorption of palladium and platinum by sulfate‐reducing bacteria
Authors: de Vargas Inmaculada , Macaskie Lynne E , Guibal Eric 
Published: December 2003

AbstractThe biosorption capacities of palladium and platinum were studied in three different species of Desulfovibrio: Desulfovibrio desulfuricans, Desulfovibrio fructosivorans and Desulfovibrio vulgaris. The influence of several parameters such as pH, acidic background and competitor anions on biosorption equilibria and biosorption kinetics were evaluated. Differences were observed between the three strains of Desulfovibrio with respect to the optimum biosorption parameters of both metals, suggesting differences in the metal speciation–dependent sorption mechanisms involved. The most promising Pd and Pt biosorption results were obtained using D desulfuricans with rapid achievement of equilibrium (90% of total sorption was achieved in 5–15 min) and a maximum value of 190 mg g−1 dry biomass and 90 mg g−1 dry biomass for Pd and Pt accumulation respectively, at pH 3. Copyright © 2003 Society of Chemical Industry
Potassium hexacyanocobalt ferrate and ammonium molybdophosphate sorption bags for the removal of 137Cs from aqueous solutions and a simulated waste
Authors: Raouf MW Abdel 
Published: December 2003

AbstractIn the present study, the removal and immobilization of 137Cs from aqueous waste solutions and a simulated waste was investigated. Two inorganic ion‐exchange complexes: di‐potassium hexacyanocobalt(II)‐ferrate(II), K2CoFe(CN)6·xH2O (KCFC), and ammonium‐12‐molybdophosphate [(NH4)3PMo12O40·aq] (AMP), were charged separately into porous nylon bags (sorption bags) of 5 µm pore diameter. The first complex (KCFC) was prepared in our laboratory. The second (AMP) was used for comparison. Easy handling and increased potential for reuse characterize the sorption bag technique. The KCFC complex was investigated by thermal gravimetric analysis (TGA) and differential thermal analysis (DTA), porosity, infra‐red (IR) and X‐ray powder diffraction (XRD). The chemical and structural investigations revealed that the KCFC complex has adequate ion‐exchange capacity and high affinity for 137Cs. The sorption bag technique showed promising results for the removal of 137Cs from aqueous waste solutions. The KCFC bags showed the highest 137Cs removal (∼0.91 g g−1), at pH 8.5; AMP bags gave the highest 137Cs removal (∼0.97 g g−1) in 0.1 N HNO3 and 1.5 N HNO3, both with a waste: sorbent ratio of 80 cm3 g−1. Sorption data for both KCFC and AMP revealed a good fit to the Freundlich sorption isotherm. To assess the potential of sorption bags, the used bags were regenerated in different leachants and reused in further sorption investigations. 137Cs recovery from the used sorbents was ∼0.46 g g−1 using 6 N HCl as leachant for AMP, compared with ∼0.253 g g−1 for KCFC using 6 N NaCl. These results indicated stronger cesium immobilization in the KCFC complex. Copyright © 2003 Society of Chemical Industry
Effect of ammonium chloride on plasmid DNA production in high cell density batch culture for biopharmaceutical use
Authors: Voss Carsten , Schmidt Torsten , Schleef Martin , Friehs Karl , Flaschel Erwin 
Published: December 2003

AbstractIn this paper the influence of ammonium salt concentration on the production of pharmaceutical grade plasmid DNA from unfed high cell density batch culture on synthetic glycerol media is presented. Ammonium chloride in different concentrations (0 mmol dm−3, 18.7 mmol dm−3, 37 mmol dm−3 and 74 mmol dm−3 supplemented) was used beside sodium glutamate as nitrogen source. Plasmid DNA concentrations of more than 50 mg dm−3 were obtained with 37 mmol dm−3 ammonium. The homogeneity of the DNA produced was confirmed by agarose and capillary gel electrophoresis and found to fulfil the quality requirements set for biopharmaceutical plasmid DNA with more than 90% in the supercoiled form. Copyright © 2003 Society of Chemical Industry
Preparation and characterization of acrylic acid‐treated bacterial cellulose cation‐exchange membrane
Authors: Choi Yong‐Jin , Ahn Yeonghee , Kang Moon‐Sung , Jun Hong‐Ki , Kim In Soo , Moon Seung‐Hyeon 
Published: December 2003

AbstractThe feasibility of using bacterial cellulose as a source for environmentally compatible ion‐exchange membranes (IEM) was studied. Bacterial cellulose was modified with cation‐exchangeable acrylic acid (AAc) by UV‐graft polymerization to prepare membranes having ion‐exchange capacity (IEC) and greater structural density. Fourier transform infrared (FTIR) spectra showed that acrylic acids were successfully bound to bacterial cellulose. Morphological changes of acrylic acid‐treated bacterial cellulose were examined through scanning electron microscopy. A dense structure of the membrane increased with increasing UV‐irradiation time. Acrylic‐modified bacterial cellulose membrane showed reasonable mechanical properties, such as tensile strength of 12 MPa and elongation of 6.0%. Also the prepared membranes were comparable to the commercial membrane CMX in terms of the electrochemical properties, ie IEC of 2.5 meq g−1‐dry mem, membrane electric resistance of 3 ohm cm2, and transport number of 0.89. Copyright © 2003 Society of Chemical Industry
Kinetic behaviour and stability of glucose oxidase entrapped in liposomes
Authors: Rodriguez‐Nogales José Manuel 
Published: December 2003

AbstractGlucose oxidase (EC 1.1.3.4) was encapsulated in liposomes (prepared from phosphatidyl choline and cholesterol) by the dehydration–rehydration method. The enzymatic activities of native and liposomal glucose oxidase were followed by the amount of H2O2 obtained in the enzymatic β‐D‐glucose oxidation. Some characteristics of the liposomal and free glucose oxidase were compared. The enzyme encapsulated in liposomes showed an apparent inhibition by glucose at concentrations higher than 0.28 mol dm−3 with a substrate inhibition constant of 0.95 ± 0.12 mol dm−3. The enzyme entrapped showed an apparent Km value higher than that of the free enzyme. The apparent Vmax of liposomal enzyme decreased by a factor of 0.35 with respect of that of the native enzyme. The optimum temperature of the free and entrapped enzymes remained similar but the liposomal enzyme showed maximal activity at a more acid pH (5.2). The thermal and proteolytic stabilities were enhanced by encapsulation in liposomes. The stabilization factors (relationship between half‐lives of entrapped form and free enzyme) at 45, 50 and 55 °C for liposomal glucose oxidase were 2.6, 1.6 and 1.6, respectively. Copyright © 2003 Society of Chemical Industry
In vitro investigation of detectability of colorectal lymph nodes and diagnosis of lymph node metastasis in colorectal cancer using B‐mode sonography
Authors: Tateishi Tsutomu , Machi Junji , Feleppa Ernest J. , Oishi Andrew J. , Furumoto Nancy L. , Oishi Robert H. , McCarthy Laurence J. , Yanagihara Eugene , Shirouzu Kazuo 
Published: December 2003

AbstractPurposeThe aim of this in vitro study was to assess the feasibility of using high‐frequency sonography to identify colorectal lymph nodes and to diagnose colorectal lymph node metastasis.MethodsIn part 1 of this study, resected colorectal tissues from 13 patients with colorectal cancer were scanned in a water bath using B‐mode sonography performed at high frequency (10 MHz) to identify lymph nodes. The colorectal tissues were then carefully dissected to remove all lymph nodes. Detectability was calculated as the ratio of the number of sonographically detected nodes to the total number of histopathologically confirmed nodes. Student's t test was performed to compare sizes between these groups; a p value of less than 0.05 was considered significant. In part 2, 4 features of lymph nodes identified on B‐mode sonography—size, shape, border, and echogenicity—and their combinations were evaluated for their ability to diagnose lymph node metastasis. Discriminant and receiver operating characteristic curve analyses were performed.ResultsIn part 1, B‐mode sonography performed in vitro detected 79 (48%) of the 165 histopathologically identified lymph nodes and 34 (87%) of the 39 histopathologically identified metastatic nodes. The mean size, or mean longest axis (± standard deviation), of the sonographically detected nodes (6.4 ± 2.9 mm) was significantly larger than that of undetected nodes (3.6 ± 1.7 mm; p < 0.01). In part 2, the most effective feature distinguishing metastatic from nonmetastatic lymph nodes was echogenicity, followed by size, shape, and border. However, a combination of at least 2 features (eg, echogenicity and size) provided better distinction of nodes than did any 1 feature. In the receiver operating characteristic curve of the 4‐feature combination, an increase in sensitivity is accompanied by a decrease in specificity: at a sensitivity of 100%, specificities decreased to 60% or less. However, even with the optimal combination of features, the sensitivity and specificity did not both reach 85% at any operating point.ConclusionsThe results of this node‐by‐node in vitro study show the current limitations and potential of sonography for assessing colorectal lymph nodes. High‐frequency sonography may be insufficient for identifying lymph node metastasis in colorectal cancer. © 2003 Wiley Periodicals, Inc. J Clin Ultrasound 32:1–7, 2004
Timing of early amniocentesis as a function of membrane fusion
Authors: Pinette Michael G. , Wax Joseph , Blackstone Jacquelyn , Cartin Angelina , McCrann Donald 
Published: December 2003

AbstractPurposeThe purpose of this prospective study was to evaluate sonographically the timing of membrane fusion and to determine its possible effect on the timing of amniocentesis.MethodsBetween May 18, 1998, and January 31, 2002, the status of amnion fusion in pregnant patients at 9–15 weeks' menstrual age was identified in women who were to undergo obstetric sonography. Amniocentesis was performed if even a small area of fused membranes that could be traversed was identified; if the membranes were completely unfused, amniocentesis was delayed. The effect of membrane fusion in terms of the need to reschedule amniocentesis was evaluated.ResultsWe examined a total of 594 patients. Membrane fusion occurred progressively with increasing menstrual age. One hundred six early amniocenteses were scheduled, and 70 were performed; the others were delayed because the membranes were unfused. Our requirement that an area of membrane fusion be found before we would perform amniocentesis resulted in rescheduling the procedure 24–38% of the time.ConclusionsMembrane fusion, as seen sonographically, is a function of menstrual age. Even by 15 weeks, a portion of the amnion may be unfused with the chorion. Amniocenteses scheduled for early in the pregnancy may need to be delayed until later, when the membranes are at least partially fused, allowing safe passage of a needle. Delaying the procedure may incur higher expense but may be important in terms of lessening the risk involved. © 2003 Wiley Periodicals, Inc. J Clin Ultrasound 32:8–11, 2004
Popliteal artery pseudoaneurysm: A rare complication of brucellosis
Authors: Harman Mustafa , Irmak Hasan , Arslan Halil , Arslan Ünal , Kayan Mustafa 
Published: December 2003

AbstractBrucellosis is still a public health problem, particularly in developing countries. After the primary infection subsides, a chronic stage characterized by nonspecific manifestations can develop, during which it may not be possible to isolate Brucella organisms and agglutination test titers may or may not be high. We present the case of a 49‐year‐old man who had only nonspecific symptoms and a 2‐month history of a pulsatile painful swelling in his right popliteal region. He had no history of trauma or surgery in that region, but he did ingest unpasteurized milk products. The patient's agglutination test titers were high, and Brucella melitensis was isolated from a bone marrow culture. Color Doppler sonography, T2‐weighted MRI, and digital subtraction angiography were performed. Treatment with ultrasound‐guided compression of the pseudoaneurysm failed because of high blood flow in its neck. Aneurysmectomy was undertaken, and the excised material was consistent with that from a mycotic pseudoaneurysm. Although both MRI and angiography provided useful information, the color Doppler sonography findings were characteristic of a pseudoaneurysm in the popliteal artery, and only that modality could detect the flow dynamics within the pseudoaneurysm. © 2003 Wiley Periodicals, Inc. J Clin Ultrasound 32:33–36, 2004
Sonographic findings in a patient with cystic hypersecretory duct carcinoma of the breast
Authors: Park Changsook , Jung Jung Im , Lee Ah‐Won , Cheon Hae Myung , Hahn Seong Tai , Lee Jae Mun 
Published: December 2003

AbstractIn this report, we describe a case of a rare form of intraductal carcinoma of the breast known as cystic hypersecretory duct carcinoma in a 49‐year‐old woman with a palpable mass and no history of breast disease. Mammography showed heterogeneous dense breast tissue with no definite abnormally increased density or microcalcifications. Gray‐scale sonography detected multiple small aggregated, anechoic cysts with good through‐transmission in the upper outer quadrant of the left breast, corresponding to the location of the palpable mass. The patient underwent an excision biopsy, and histopathologic examination of the surgical specimen revealed multiple cysts of different size containing an eosinophilic material resembling thyroid colloid. The locations of the cysts corresponded to those of the anechoic cysts detected on sonography. The epithelium lining the cysts showed micropapillary growth consistent with a diagnosis of cystic hypersecretory duct carcinoma. The mammographic and sonographic findings in this case differed somewhat from those reported previously for this rare form of breast carcinoma. Because the imaging findings and low‐power microscopic appearance of the mass in our patient's case closely resembled those of some benign breast lesions, we recommend careful differentiation of this type of lesion using high‐power microscopy during histopathologic evaluation. © 2003 Wiley Periodicals, Inc. J Clin Ultrasound 32:29–32, 2004
Clinical applications of diffusion tensor imaging
Authors: Dong Qian , Welsh Robert C. , Chenevert Thomas L. , Carlos Ruth C. , Maly‐Sundgren Pia , Gomez‐Hassan Diana M. , Mukherji Suresh K. 
Published: December 2003

AbstractDirectionally‐ordered cellular structures that impede water motion, such as cell membranes and myelin, result in water mobility that is also directionally‐dependent. Diffusion tensor imaging characterizes this directional nature of water motion and thereby provides structural information that cannot be obtained by standard anatomic imaging. Quantitative apparent diffusion coefficients and fractional anisotropy have emerged from being primarily research tools to methods enabling valuable clinical applications. This review describes the clinical utility of diffusion tensor imaging, including the basic principles of the technique, acquisition, data analysis, and the major clinical applications. J. Magn. Reson. Imaging 2004;19:6–18. © 2003 Wiley‐Liss, Inc.
Proton magnetic resonance spectroscopic imaging of human breast cancer: A preliminary study
Authors: Jacobs Michael A. , Barker Peter B. , Bottomley Paul A. , Bhujwalla Zaver , Bluemke David A. 
Published: December 2003

AbstractPurposeTo investigate the diagnostic value of proton magnetic resonance spectroscopic imaging (MRSI) in patients with breast lesions.Materials and MethodsEighteen patients underwent breast MRSI and MRI at 1.5 T. Contrast‐enhanced MR was used to identify the lesion, after which single‐slice MRSI (TR/TE = 2000/272 msec, 10‐mm slice thickness) was performed. Water, lipid, and choline (Cho) images were reconstructed from MRSI data. The area of the Cho was measured in the lesion and expressed relative to the background noise level (signal‐to‐noise ratio (SNR)), measured between 7.0 and 9.0 ppm. Cho SNRs were compared between benign and malignant lesions as determined by histopathology.ResultsThree cases were considered technical failures on MRSI. Of the remaining 15 cases, on histopathology, eight were classified as malignant carcinoma and seven were benign. The Cho SNR from malignant tissue was significantly elevated compared to benign tissue (6.2 ± 2.1 vs. 2.4 ± 0.7, P < 0.0008).ConclusionsMRSI measurements of Cho are feasible in the human breast, and the SNR for Cho was significantly different between benign and malignant lesions. The potential advantages of MRSI over SV spectroscopy include the ability to assess multiple lesions as well as tissue with normal MRI appearance, as well as to perhaps gauge lesion borders and infiltration into surrounding tissue. J. Magn. Reson. Imaging 2004;19:68–75. © 2003 Wiley‐Liss, Inc.
Cine MR imaging of heart valve dysfunction with segmented true fast imaging with steady state free precession
Authors: Krombach Gabriele A. , Kühl Harald , Bücker Arno , Mahnken Andreas H. , Spüntrup Elmar , Lipke Claudia , Schröder Jörg , Günther Rolf W. 
Published: December 2003

AbstractPurposeTo evaluate the value of cine true fast imaging with steady‐state free precession (SSFP) for semiquantitative assessment of valvular dysfunction in the heart and to compare the results to that obtained with a standard breath‐hold segmented gradient‐recalled echo‐planar imaging sequence (GE‐EPI).Materials and MethodsTwenty‐three patients with known valvular dysfunction (main component: 16 with aortic valve stenosis, nine with aortic valve insufficiency, three with mitral stenosis, two with mitral regurgitation, two with tricuspidal regurgitation, and one with pulmonary stenosis) and 23 control subjects with normal valvular function underwent MR imaging on a 1.5‐T system (ACS‐NT, Philips, Best, The Netherlands). Cine SSFP and GE‐EPI images were acquired in identical long‐axis views. Images were evaluated for the presence and extent of the signal void arising from the valves and for image quality consensus by two experienced radiologists. Results were compared to those obtained by cardiac catheterization (in 16 patients) or color Doppler (in the remaining seven patients).ResultsOn SSPF images, the complex flow pattern in valvular regurgitant or stenotic lesions caused signal void within the bright blood pool of the atria or ventricles, similar to GE‐EPI, in all patients. Valvular dysfunction was delineated using SSFP with the same high sensitivity (100%) as using the GE‐EPI sequence. Results correlated to those obtained by cardiac catheterization or color Doppler ultrasonography (P < 0.001, r = 0.97). However, the jet phenomenon was slightly more pronounced in five patients on GE‐EPI. There was no significant signal void in the 23 control subjects with both sequences. In all 46 subjects, the image quality of SSFP images was rated higher (P < 0.05; 2.6 ± 0.1; using a scale ranging from 0–3) compared to GE‐EPI (1.7 ± 0.1).ConclusionThe results of this study suggest that valvular dysfunction can be semiquantitatively assessed using SSFP cine MR imaging. J. Magn. Reson. Imaging 2004;19:59–67. © 2003 Wiley‐Liss, Inc.