bluuebunny/crossref_metadata_2025_split huggingface dataset:
Choice of Spin–Orbit Correction Terms in Gaussian Model Chemistries
Authors: Duke Brian J. 
Published: October 2004

AbstractSpin–orbit correction terms for use in Gaussian‐2 theory and other model chemistries for third‐row atoms and molecules are calculated by several methods with the objective of finding a reliable method that can be applied in a routine and economical manner in the spirit of Gaussian model chemistries. The results are evaluated for the test set of molecules and ions used in the original extension of Gaussian‐2 theory to third‐row atoms. Further results are presented for systems where Gaussian‐2 results are reported in the literature without spin–orbit correction terms and for some larger molecules. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1552–1556, 2001
On the interaction of Mo and Mo2 with NH3, C2H4, and C3H6
Authors: Lacaze‐Dufaure Corinne , Mineva Tzonka , Russo Nino 
Published: October 2004

AbstractThe reactivity of Mo and Mo2 with ammonia, ethene, and propene molecules has been investigated by using Density Functional Theory. Different gradient‐corrected and hybrid exchange‐correlation functionals have been employed. Coordination modes, binding energies, geometrical structures, vibrational frequencies have been computed and compared with the available experimental counterparts. The results obtained show that the molybdenum atom is able to react with C2H4 and C3H6, and binds weakly with NH3. The dimer Mo2 gives a stable complexes with ammonia, ethene, and propene. For the Mo2NH3 complex, all the employed levels of theory give binding energies in good agreement with the experimental value, while in the case of the MoC2H4 system, the use of model core potentials coupled with gradient‐corrected exchange‐correlation functionals overestimates the binding energies. For MoC3H6, Mo2C2H4, and Mo2C3H6 we predict a binding energy of 14–15, 20–24, and 18–20 kcal/mol, respectively. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1557–1564, 2001
Systematic Study of Selected Diagonalization Methods for Configuration Interaction Matrices
Authors: Leininger Matthew L. , Sherrill C. David , Allen Wesley D. , Schaefer Henry F. 
Published: October 2004

AbstractSeveral modifications to the Davidson algorithm are systematically explored to establish their performance for an assortment of configuration interaction (CI) computations. The combination of a generalized Davidson method, a periodic two‐vector subspace collapse, and a blocked Davidson approach for multiple roots is determined to retain the convergence characteristics of the full subspace method. This approach permits the efficient computation of wave functions for large‐scale CI matrices by eliminating the need to ever store more than three expansion vectors (bi) and associated matrix‐vector products (σi), thereby dramatically reducing the I/O requirements relative to the full subspace scheme. The minimal‐storage, single‐vector method of Olsen is found to be a reasonable alternative for obtaining energies of well‐behaved systems to within μEh accuracy, although it typically requires around 50% more iterations and at times is too inefficient to yield high accuracy (ca. 10−10 Eh) for very large CI problems. Several approximations to the diagonal elements of the CI Hamiltonian matrix are found to allow simple on‐the‐fly computation of the preconditioning matrix, to maintain the spin symmetry of the determinant‐based wave function, and to preserve the convergence characteristics of the diagonalization procedure. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1574–1589, 2001
A density functional theory study of the dimers of HX (X = F, Cl, and Br)
Authors: Rankin Kathryn N. , Boyd Russell J. 
Published: October 2004

AbstractThe geometries, interaction energies, and vibrational properties of (HF)2, (HCl)2, and (HBr)2 have been investigated using a variety of hybrid density functional methods and the 6‐311+G(2df,p) basis set. Although most of the density functional methods predict geometries in reasonable agreement with experiment, methods containing the LYP correlation functional yield geometrical parameters in slightly better agreement. The (HF)2 interaction energy, predicted by the hybrid density functional methods, is in reasonable agreement with experiment, but the (HCl)2 and (HBr)2 interaction energies are underestimated substantially. The frequency shift for the XH donor bond correlates linearly with the elongation of the XH bond upon complexation, and is predicted reasonably well by methods containing the LYP functional. Overall, the hybrid density functional methods adequately predict the properties of the halide dimers. It is interesting to note that the BHandHLYP and B1LYP density functional methods offer a competitive alternative to the popular B3LYP method. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1590–1597, 2001
Configuration interaction and density functional study of the influence of lithium cation complexation on vertical and adiabatic excitation energies of enones
Authors: Sunoj R. B. , Lakshminarasimhan P. , Ramamurthy V. , Chandrasekhar J. 
Published: October 2004

AbstractThe changes in the excited state energies of representative cyclic enones (cyclopentenone and cyclohexenone) induced by lithium ion coordination have been examined using ab initio and DFT methods. Quantitative estimates of the vertical triplet state energies were obtained using configuration interaction calculations at the CIS and CIS(D) levels with the 6‐31+G(d) basis. Inclusion of perturbative doubles corrections has a marked effect on the relative energies of the n–π* and π–π* triplet states. At both CI and CIS(D) levels, lithium complexation is predicted to raise the energy of the n–π* triplet state much more than the π–π* triplet. The trends obtained at the CIS(D) level are reproduced using B3LYP/6‐31+G(d) calculations. Adiabatic excitation energies were also computed by carrying out geometry optimization of the triplet states at the B3LYP level. While the separation between the geometry optimized n–π* and π–π* triplet states is very small for the parent enones, the π–π* triplet is clearly favored in the lithium complexes. These results suggest the possibility of reversing the reactive photoexcited state in enones through cation complexation. The conclusions provide a rationale for interesting variations in product distributions observed for enones in cation exchanged zeolites. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1598–1604, 2001
Analytical TDHF second derivatives of dynamic electronic polarizability with respect to nuclear coordinates. Application to the dynamic ZPVA correction
Authors: Quinet Olivier , Champagne Benoît , Kirtman Bernard 
Published: October 2004

AbstractAnalytical calculation of second derivatives of the dynamic electronic polarizability with respect to vibrational normal coordinates has been implemented at the TDHF level of approximation. Important simplifications are obtained by using the 2n+1 rule and interchange relations. In application to small molecules the first‐order ZPVA correction is found to have greater frequency dispersion than the electronic polarizability, but the former remains small in comparison. For the linear polyenes, C2nH2n+2 (n=1–3), the percentage ZPVA correction decreases with chain length for all ℏω<0.10 a.u. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1920–1932, 2001
Religious groups as diffusers of HIV antibody testing and prevention messages
Authors: Lightfoot Marguerita , Rotheram‐Borus Mary Jane , Towns Belinda , Cline Timothy R. , Webber Douglas , Murphy Debra A. , Tsai Lan Feng 
Published: October 2004

AbstractUsing a quasi‐experimental design, this study examined how delivering a brief training to volunteers in church congregations impacted (a) church volunteers' persistence in delivering HIV antibody testing messages over time and (b) HIV antibody testing behavior of the church volunteers themselves. Church volunteers attended a briefing regarding delivery of public health messages to others and the churches were assigned to either: (a) a trained condition, where 345 volunteers received an additional 3‐hour training in diffusing HIV prevention messages, or (b) a comparison condition, where 199 volunteers received no HIV‐specific training. Three months after the intervention, church volunteers in the HIV‐trained condition reported delivering an HIV antibody testing and prevention message to more community members than volunteers in the comparison condition. Those in the HIV‐trained condition also reported significantly higher levels of comfort and self‐efficacy in delivering HIV prevention messages than volunteers in the comparison condition. However, the trained volunteers did not themselves get tested for HIV at higher rates than the untrained volunteers. Training church volunteers for community diffusion of HIV prevention messages is an efficient strategy for diffusing HIV messages. © 2001 John Wiley & Sons, Inc.
Motion detectors in the locust visual system: From biology to robot sensors
Authors: Rind F. Claire 
Published: October 2004

AbstractMotion detectors in the locust optic lobe and brain fall into two categories: neurones that respond selectively to approaching vs. receding objects and neurones that respond selectively to a particular pattern of image motion over a substantial part of the eye, generated by the locust's own movements through its environment. Neurones from the two categories can be differentiated on the basis of their response to motion at a constant velocity at a fixed distance from the locust: neurones of the first category respond equally well to motion in any direction whereas neurones in the second category respond selectively to one preferred direction of motion. Several of the motion detectors of the first category, responding to approaching objects, share the same input organisation, suggesting that it is important in generating a tuning for approaching objects. Anatomical, physiological, and modelling studies have revealed how the selectivity of the response is generated. The selectivity arises as a result of a critical race between excitation, generated when image edges move out over the eye and delayed inhibition, generated by the same edge movements. For excitation to build up, the velocity and extent of edge motion over the eye must increase rapidly. The ultrastructure of the afferent inputs onto the dendrites of collision sensitive neurones reveals a possible substrate for the interaction between excitation and inhibition. This interpretation is supported by both physiological and immunocytochemical evidence. The input organisation of these neurones has been incorporated into the control structure of a small mobile robot, which successfully avoids collisions with looming objects. The ecological role of motion detectors of the second category that respond to image motion over a substantial part of the visual field, is discussed as is the input organisation that generates this selective response. The broad tuning of these neurones, particularly at low velocities (<0.02°/s), suggests they may have a role in navigation during migratory flights at altitude. By contrast, their optimum tuning to high‐image velocities suggests these motion detectors are adapted for use in a fast flying insect, which does not spend significant time hovering. Microsc. Res. Tech. 56:256–269, 2002. © 2002 Wiley‐Liss, Inc.
Novel method for the plan‐view TEM preparation of thin samples on brittle substrates by mechanical and ion beam thinning
Authors: Sáfrán G. , Grenet T. 
Published: October 2004

AbstractA new preparation method has been developed in order to avoid the breaking of brittle samples for plan‐view TEM investigation during and after mechanical and ion beam thinning. The thinning procedure is carried out on a reduced size piece of the sample (about 1.6 × 0.8 mm2 or about 1–1.6 mm diameter) that is embedded into a 3‐mm‐diameter Ti disk, which fits the sample holder of the TEM. The small sample size and the supporting metal disk assure the mechanical stability and minimize the possibility of breaking during and after the preparation: The Ti disk is placed on adhesive kapton tape, a cut piece of the sample is put into the slot of the disk, pressed onto the tape and embedded with glue. The tape keeps the parts in place and in the same plane, keeps the sample surface safe from the embedding glue and can be removed easily after the glue solidifies. Subsequently, the embedded sample is thinned from the rear by well‐known mechanical and ion beam techniques until electron transparency. This simple solution lowers the risk of failed sample preparation remarkably and makes it possible to reduce the thickness of the sample to about 50 μm by mechanical thinning. As a result, dimpling becomes unnecessary and low angle ion milling gives a large transparent area for TEM. Its efficiency has been proved by successful preparation of numerous thin film samples on Si, sapphire, and glass substrates. The method is compatible with the widespread cross‐sectional thinning procedures, and can be easily adopted by TEM laboratories. Microsc. Res. Tech. 56:308–314, 2002. © 2002 Wiley‐Liss, Inc.
Recent advances in the histochemical staining of heavy metals by means of chelating agents, with special reference to cadmium
Authors: Sumi Y. , Suzuki T. 
Published: October 2004

AbstractThis review discusses the way of improving the sensitivity and specificity of chelating agents used for the histochemical demonstration of trace amounts of heavy metals in cells and tissues. In the search for a more sensitive and specific agent, various chelating agents have been prepared and their staining properties for various metals examined. Of those developed 1‐(2‐benzothiazolylazo)‐2‐naphthol (BTAN), 2‐(8‐quinolylazo)‐4,5‐(diphenyl)imidazole (QAI), and 2‐(5‐bromo‐2‐pridylazo)‐5‐(diethylamino)phenol (BrPADAP) were far superior to conventional staining agents in staining sensitivity. This was particularly so for staining cadmium. When modifying chelating agents to increase staining sensitivity, hydrophobicity of the agent molecules, selection of substituent groups, and the position of the groups added to the agent molecules must be taken into consideration. The most frequently mentioned factors in a staining mechanism are complex‐tissue attractive forces, and recent studies have made it clear that weak interactions, such as hydrogen bonds and hydrophobic interactions, contribute significantly. The Hansch π values were a useful indication of the hydrophobicity of metal staining agents. The published values for stability constants of metal complexes were found to be unreliable guides for choosing a masking agent to block interfering metals. The polyphosphates, aminopolycarboxylic acids, and alkylamines were among the most useful masking agents for metal staining from a practical standpoint. Microsc. Res. Tech. 56:332–340, 2002. © 2002 Wiley‐Liss, Inc.
Photosensory transduction in unicellular eukaryote Blepharisma
Authors: Matsuoka Tatsuomi , Kotsuki Hiyoshizo 
Published: October 2004

AbstractIn the ciliated protozoan Blepharisma, step‐up photophobic response is mediated by a novel type of photosensory complex of pink‐colored pigment “blepharismins” and 200‐kDa membrane protein contained in the pigment granules located just beneath the plasma membrane. We found that the fluorescence intensity of isolated blepharismins decreased prominently with a decrease of H+ concentration in the surrounding medium. In the present study, therefore, we utilized the endogenous pigment blepharismins as the pH indicator. Light stimulation evoked a sudden decrease in fluorescence intensity in a photosensitive anterior portion of the cell, suggesting that a drop in H+ concentration occurred in the anterior region. The result indicates that the photosignal is transduced into cytoplasmic signaling of H+ translocation across the outer membrane surrounding the pigment granules, so that cytosolic H+ concentration in the vicinity of plasma membrane might be increased. J. Exp. Zool. 289:467–471, 2001. © 2001 Wiley‐Liss, Inc.
Thinking through war: The social thought of Richard T. Ely, John R. Commons, and Edward A. Ross during the First World War
Authors: Herzberg David 
Published: October 2004

AbstractThis paper examines the social thought of University of Wisconsin professors Richard T. Ely, John R. Commons, and Edward A. Ross during World War I. Like many of their fellow scholars, these three were actively involved in the pro‐war effort. Although their support for the war was strongly conditioned by personal and occupational considerations, the impact of their wartime service was not restricted to those realms. Their social thought, which they impressed into service explaining and justifying the war, was itself altered in subtle and sometimes surprising ways by the forceful positions they took on the political, economic, and racial significance of the conflict. © 2001 John Wiley & Sons, Inc.
Voxel‐based analysis of MTR images: A method to locate gray matter abnormalities in patients at the earliest stage of multiple sclerosis
Authors: Audoin Bertrand , Ranjeva Jean‐Philippe , Duong My Van Au , Ibarrola Danielle , Malikova Irina , Confort‐Gouny Sylviane , Soulier Elisabeth , Viout Patrick , Ali‐Chérif André , Pelletier Jean , Cozzone Patrick J. 
Published: October 2004

AbstractPurposeTo determine whether voxel‐based analysis of magnetization transfer ratio (MTR) maps can provide evidence of a coherent pattern of gray matter (GM) macroscopic and microscopic tissue damage in patients at the earliest stage of multiple sclerosis (MS).Materials and MethodsWe acquired GM MTR maps in 18 patients with clinically isolated syndrome suggestive of MS (CISSMS), and 18 sex‐ and age‐matched healthy controls. We evaluated the clinical status of the patients using the MS functional composite score and the expanded disability status scale. A two‐sample t‐test (P < 0.0001, k = 20, uncorrected for height threshold) was used to compare GM MTR maps from patients and controls on a voxel‐by‐voxel basis. We then extracted data from regions with t‐values above the statistical threshold to verify the significance of differences using a nonparametric Mann‐Whitney U‐test.ResultsA between‐groups comparison of GM maps revealed large abnormalities in the basal ganglia, including the bilateral thalamus, bilateral lenticular nucleus, bilateral head of caudate, and protuberance, and smaller abnormalities in the right insula, right BA 4, and left BA 40. The MTR measured in the left caudate and right insula was inversely correlated with duration following the first clinical event.ConclusionThese results suggest that although MS is a multifocal demyelinating disease that affects white matter (WM), a pattern of tissue damage is present inside the GM involving predominantly basal ganglia at the earliest stage of the disease. J. Magn. Reson. Imaging 2004;20:765–771. © 2004 Wiley‐Liss, Inc.
Cross‐reactivity and clinical impact of the antibody response to hepatitis C virus second envelope glycoprotein (E2)
Authors: Hadlock Kenneth G. , Gish Robert , Rowe Judy , Rajyaguru Sonal S. , Newsom Margaret , Warford Ann , Foung Steven K.H. 
Published: October 2004

AbstractThe genotype of hepatitis C virus (HCV) can profoundly affect the success of antiviral therapy for HCV infection. A possible contributing factor is a varied immune response elicited by infection with different HCV genotypes. In this study, full‐length E2 proteins of HCV genotypes 1a, 1b, 2a, and 2b were used to determine the fraction of the humoral immune response to HCV E2 that is genotype specific. Greater than 90% of all infected individuals had serum antibodies to the four E2 proteins. Overall, individuals infected with genotype 1a or 1b were characterized by variable immune responses to HCV E2 with relatively high amounts of cross‐reactivity with other E2 proteins. Individuals infected with genotype 2a or 2b exhibited a strong preferential reactivity to genotype 2a and 2b E2 proteins. Individuals with elevated titers to HCV E2 were more likely to be infected with genotype 2a and had a significantly lower median viral load. These findings indicate that the antibody response to HCV E2 is affected by the genotype of the virus and that induction of a strong humoral immune response to HCV E2 may contribute to a decreased viral load. J. Med. Virol. 65:23–29, 2001. © 2001 Wiley‐Liss, Inc.
Japan‐specific subtype of hepatitis C virus genotype 1b, J subtype, has relatively low pathogenicity
Authors: Nakano Isao , Fukuda Yoshihide , Katano Yoshiaki , Toyoda Hidenori , Hayashi Kazuhiko , Kumada Takashi , Nakano Satoshi 
Published: October 2004

AbstractThe prognostic implication of viral genotype 1b for hepatitis C virus (HCV) infection has been controversial, possibly due to the pathogenetic heterogeneity of genotype 1b. We analyzed two newly delineated subtypes of HCV genotype 1b subtypes with respect to progression of liver disease. Patients with chronic HCV 1b infection (113 total, including 18 with chronic persistent hepatitis, 60 with chronic active hepatitis, 19 with cirrhosis, and 16 with hepatocellular carcinoma with cirrhosis) were studied to elucidate the factors associated with progression of liver disease. Factors evaluated included sex, age at diagnosis, blood transfusion history, and HCV genotype 1b subtype (W subtype or J subtype). W subtype was identified more often in association with chronic active hepatitis than with chronic persistent hepatitis (P = 0.0089), and more often in patients with cirrhosis than in those without (P = 0.0044). The age‐, sex‐, and transfusion history‐adjusted odds ratios with respect to histological activity and presence of cirrhosis for W subtype compared to J subtype were 6.966 (1.856 to 26.145) and 6.397 (1.506 to 27.179), respectively. Age at diagnosis was the most important risk factor for predicting development of cirrhosis and carcinoma. In conclusion, the W subtype of HCV 1b is associated closely with histologically active disease and development of cirrhosis, whereas the Japan‐specific J subtype has relatively low pathogenicity. HCV genotype 1b, therefore, is heterogeneous in its pathogenicity. J. Med. Virol. 65:45–51, 2001. © 2001 Wiley‐Liss, Inc.
Aciclovir selects for ganciclovir‐cross‐resistance of human cytomegalovirus in vitro that is only in part explained by known mutations in the UL97 protein*
Authors: Michel Detlef , Höhn Simone , Haller Tobias , Jun Dou , Mertens Thomas 
Published: October 2004

AbstractPhenotypically, ganciclovir‐resistant human cytomegalovirus strains could be selected by aciclovir as effectively as by ganciclovir in vitro. Three clinical human cytomegalovirus isolates with different sensitivities against ganciclovir, aciclovir, foscarnet, and cidofovir, but without any mutation in the viral UL97 protein known to confer ganciclovir resistance, were propagated each in duplicate in the presence of ganciclovir or aciclovir. After drug selection, all 12 strains were less susceptible to ganciclovir (increase of 50% focus reduction dose between 2.1– and 31.5‐fold) but were still sensitive to foscarnet and cidofovir; 7/12 exhibited a ganciclovir‐resistant phenotype with a 50% focus reduction dose >30 μM, and in 6 out of these typical mutations in the UL97 coding region could be found by genotyping. All four strains selected from one isolate carried the identical UL97 mutation at amino acid position 460 (methionine to valine). The decreased sensitivity to ganciclovir and aciclovir in the other strains could neither be attributed to known UL97 mutations nor to mutations in the viral polymerase (UL54), which have been reported to induce resistance. J. Med. Virol. 65:70–76, 2001. © 2001 Wiley‐Liss, Inc.