bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and cellular biocompatibility of two kinds of HAP with different nanocrystal morphology
Authors: Zhao Yantao , Zhang Yumei , Ning Fang , Guo Dagang , Xu Zhixuan 
Published: March 2007

AbstractTwo kinds of hydroxyapatite (HA) with different nanocrystal morphology were obtained via a simple aqueous precipitation method under different reactants molar ratios. Under Ca/P molar ratio of 1.67/1, rod‐like crystal was produced, while under Ca/P molar ratio of 1.80/1, spherical crystal was produced. The spherical crystal was 40–60 nm in diameter, while the rod‐like crystal was 40–55 nm in diameter and 79–100 nm in length. The influence of HA nanocrystal morphology on osteoblasts growth was assayed by MTT method and SEM. The results indicated that there was a significantly higher absorbency value on the surface of HA with spherical crystal in MTT assay than the latter. In the process of SEM observation, it is found that osteoblasts spread out a large quantity of nano‐filopodias on spherical crystal surface, thus exhibiting much more active cell morphology. In conclusion, HA with spherical nanocrystal showed more favorable properties than that with rod‐like one for osteoblasts. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Characterization, quantification, and isolation of aluminum oxide particles on grit blasted titanium aluminum alloy hip implants
Authors: Grübl Alexander , Kolb Alexander , Reinisch Georg , Fafilek Günter , Skrbensky Gobert , Kotz Rainer 
Published: March 2007

AbstractBackground: This study was undertaken to verify whether or not the microstructure of aluminum alloy implants interferes with the characterization and quantification of aluminum inclusions on their surfaces, resulting from grit blasting. Methods: Four factory‐fresh prostheses were investigated by scanning electron microscopy and X‐ray microanalysis. Specimens were cut out of the stems and the cross‐sections analyzed. The specimens were etched in hot 25% hydrochloric acid. The hydrochloric acid was subsequently filtered with a 0.2‐μm‐pore filter. The filters were scanned using electron microscopy and X‐ray microanalysis. Results: Aluminum oxide particles were found on all investigated stems; the diameter of the particles ranged from 4 to 100 μm. One hundred fifty‐four particles were counted per mm2. No particles were seen on the cross‐sections of the implants. Scanning electron microscopy of the Millipore filters revealed aluminum oxide particles. Conclusion: Remnants of grit blasting were found only on the surfaces; none were observed on cross‐sections. We conclude that the microstructure of titanium aluminum alloy does not interfere with the identification and quantification of particles. Particles were identified on the filters by electron microscopy and X‐ray microanalysis. Aluminum oxide on the surface of grit‐blasted titanium aluminum alloy implants is, in fact, a residue of grit blasting. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Using pseudo amino acid composition to predict protein structural class: Approached by incorporating 400 dipeptide components
Authors: Lin Hao , Li Qian‐Zhong 
Published: March 2007

AbstractThe proteins structure can be mainly classified into four classes: all‐α, all‐β, α/β, and α + β protein according to their chain fold topologies. For the purpose of predicting the protein structural class, a new predicting algorithm, in which the increment of diversity combines with Quadratic Discriminant analysis, is presented to study and predict protein structural class. On the basis of the concept of the pseudo amino acid composition (Chou, Proteins: Struct Funct Genet 2001, 43, 246; Erratum: Proteins Struct Funct Genet 2001, 44, 60), 400 dipeptide components and 20 amino acid composition are, respectively, selected as parameters of diversity source. Total of 204 nonhomologous proteins constructed by Chou (Chou, Biochem Biophys Res Commun 1999, 264, 216) are used for training and testing the predictive model. The predicted results by using the pseudo amino acids approach as proposed in this paper can remarkably improve the success rates, and hence the current method may play a complementary role to other existing methods for predicting protein structural classification. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Atoms in molecules interpretation of the anomeric effect in the OCO unit
Authors: Vila Antonio , Mosquera Ricardo A. 
Published: March 2007

AbstractThe conformational preferences of two model compounds for the OCH2O anomeric unit: methanediol and dimethoxymethane analyzed within the framework of the QTAIM theory provide a new interpretation of the anomeric effect. The characteristic stabilization of the gauche conformers of these compounds is accompanied by a progressive reduction of the electron population of the hydrogens of the central methylene as the number of their gauche interactions to lone pairs rises. The electron population removed from these atoms during the conformational change is gained in the gauche conformers by atoms of larger atomic number, which results in a more negative molecular energy. Also, the variations displayed by atomic populations and the QTAIM delocalization indexes are not keeping in line with the hyperconjugative model of the anomeric effect. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Pseudopericyclic design drives antara‐antara [1,5] methylene sigmatropic shifts from a stepwise to a concerted mechanism
Authors: López Carlos Silva , Faza Olalla Nieto , Souto José A. , Álvarez Rosana , De Lera Ángel R. 
Published: March 2007

AbstractAntara‐antara [1,5]‐methylene sigmatropic shifts of propenylidene cyclopropane and its heteroanalogues are shown to proceed through concerted or stepwise mechanisms depending on a delicate balance that is directly related to the presence or absence of heteroatoms at the termini atoms of the rearrangement. Lowering of activation energies upon heteroatom replacement are more significant for the oxacyclopropane analogues 1D, 1E, and 1F but double heterosubstitution is still needed to achieve a pseudopericyclic reaction. In fact only after reaching a pseudopericyclic process the energy balance favors the concerted pathway. Negligible NICS values and a clear disconnection in the ACID plot as well as some structural and energetical parameters reveal the pseudopericyclic nature of this concerted antara‐antara [1,5] sigmatropic shift. Although the product of the pseudopericyclic process is unprecedented, similar cycloisomerizations after allene activation should be considered within this hitherto undescribed reactions. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Accuracy of the three‐body fragment molecular orbital method applied to Møller–Plesset perturbation theory
Authors: Fedorov Dmitri G. , Ishimura Kazuya , Ishida Toyokazu , Kitaura Kazuo , Pulay Peter , Nagase Shigeru 
Published: March 2007

AbstractThe three‐body energy expansion in the fragment molecular orbital method (FMO) was applied to the 2nd order Møller–Plesset theory (MP2). The accuracy of both the two and three‐body expansions was determined for water clusters, alanine n‐mers (α‐helices and β‐strands) and one synthetic protein, using the 6‐31G* and 6‐311G* basis sets. At the best level of theory (three‐body, two molecules/residues per fragment), the absolute errors in energy relative to ab initio MP2 were at most 1.2 and 5.0 mhartree, for the 6‐31G* and 6‐311G* basis sets, respectively. The relative accuracy was at worst 99.996% and 99.96%, for 6‐31G* and 6‐311G*, respectively. A three‐body approximation was introduced and the optimum threshold value was determined. The protein calculation (6‐31G*) at the production level (FMO2/2) took 3 h on 36 3.2‐GHz Pentium 4 nodes and had the absolute error in the MP2 correlation energy of only 2 kcal/mol. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Electronic properties of tricoordinated phosphorus in hexagonal phosphininium compounds and molecular aromaticity
Authors: Li Wei‐Qi , Tian Wei‐Quan , Feng Ji‐Kang , Liu Zi‐Zhong , Ren Ai‐Min , Sun Chia‐Chung , Aoki Yuriko 
Published: March 2007

AbstractCalculations with B3LYP within quantum chemical density functional theory have been carried out for 1‐H‐phosphininium cation and a series of 1‐R‐phosphininium molecules (R = cyclopentadiene, α and β pyrroles, α and β phosphole, C5BH5 and CH2). The negative nuclear‐independent chemical shift values and the positive aromatic stabilization energies confirm that they are aromatic compounds. In particular, the 1‐H‐phosphininium cation even exhibits stronger aromatic character than the well‐known aromatic phosphinine. The aromatic substituents have strong capability to attract electrons. It is the conjugation and aromaticity that keeps the stability and conformations of the molecules investigated. Owing to the perturbation of the aromatic substituted groups, the predicted large T values and the enlarged HOMO‐LUMO gap of the phosphininium cation indicate that these compounds are expected in experiment. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Vibrational corrections to geometries of transition metal complexes from density functional theory
Authors: Waller Mark P. , Bühl Michael 
Published: March 2007

AbstractZero‐point vibrational corrections are computed at the BP86/AE1 level for the set of 50 transition‐metal/ligand bonds that have recently been proposed as testing ground for DFT methods, because of the availability of precise experimental gas‐phase geometries (Bühl and Kabrede, J Chem Theory Comput 2006, 2, 1282). These corrections are indicated to be transferable to a large extent between various density‐functional/basis‐set combinations, so that they can be used to estimate zero‐point averaged r distances from re values optimized at other theoretical levels. Applying this approach to a number of popular DFT levels does not, in general, improve their overall accuracy in terms of mean and standard deviations from experiment. The hybrid variant of the meta‐functional TPSS is confirmed as promising choice for computing structures of transition‐metal complexes. © 2007 Wiley Periodicals, Inc. J Comput Chem 28: 1531–1537, 2007
Vibrational anharmonic calculations in solution: Performance of various DFT approaches
Authors: Begue Didier , Pouchan Claude 
Published: March 2007

AbstractWe report anharmonic spectra calculated for formaldehyde in acetonitrile solution using the quartic force field obtained for various DFT/solvent coupled models. A statistical study has been carried out for each mode by using several classes of DFT functionals and comparing them to the reference ab‐initio CCSD(T)/cc‐pVQZ calculations. Results lead to the recommended use of hybrid functionals associated with the 6‐31+G** basis set and the Polarized Continuum model (PCM) to predict the expected shifts relative to the gas phase. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Serological relatedness of monkeypox, variola, and vaccinia viruses
Authors: Esposito Joseph J. , Obijeski John F. , Nakano James H. 
Published: March 2007

AbstractClosely related human and monkey orthopoxviruses were differentiated by serologic techniques. Antiviral sera were tested by immunodiffusion for reactivity against six different viral antigens prepared from either infected cell cultures or infected chorioallantoic membranes (CAMs) of embryonated eggs. Portions of each antiserum were separately absorbed with heterologous antigens from infected CAMs to remove common reactivity. The absorbed sera formed immunodiffusion precipitates with both types of antigen preparation and revealed specific‐character differences that made it possible to classify the viruses as variola, vaccinia, or monkeypox. Cross‐complement fixation tests were also used to examine the immunologic reactivities of antisera to detergent‐treated, purified preparations of three orthopoxviruses. Only common reactivities were detected by this method, however, and differentiating reactivities were not observed.
Pharmacologic effects of polyinosinic• polycytidylic acid in man
Authors: Freeman Arnold I. , Al‐Bussam Nazar , O'Malley Judith A. , Stutzman Leon , Bjornsson Sigurdur , Carter William A. 
Published: March 2007

AbstractTwenty‐four patients with cancer and concomitant infections with either herpes virus hominis or varicella zoster virus were treated with polyinosinic·polycytidylic acid (rIn·rCn) to determine: (1) the reliability of rIn·rCn to induce interferon production, and (2) the toxicity of the drug. Seven additional patients with herpes zoster were observed as controls. Two lots of rIn·rCn were used; Lot 1 was consistently effective in stimulating serum interferon at doses of 9 and 12 mg/kg, whereas Lot 2 was effective at doses of 3–12 mg/kg. There was no correlation between rIn·rCn doses within these ranges and the resultant interferon levels. Generally, peak serum interferon occurred within the first day.Toxicity to rIn·rCn consisted of fever in 21/24 patients, mild elevation of liver enzymes in 8/24 patients, and laboratory abnormalities of coagulation in 9 patients. The coagulation abnormalities appeared linearly related to the dose of rIn·rCn used. All these abnormalities were reversible, and none were considered severe or lifethreatening.Sincer rIn·rCn was effective in stimulating interferon and since toxicity was considered acceptable, a randomized double‐blind study was initiated to determine whether rIn·rCn is effective in the treatment of herpes zoster.
Antibody‐modification of measles “in vitro” infection
Authors: Gould Janine J. , Almeida June D. 
Published: March 2007

AbstractWhile the involvement of measles‐like virus with subacute sclerosing panencephalitis (SSPE) has been shown in many laboratories, the possible mechanisms by which a normal measles infection may lead to the chronic condition are unclear. The work reported here demonstrates that the growth and maintenance of Vero cells infected with the MV 30 strain of measles, in the presence of multivalent antibody, results in a redistribution of the viral antigens within the cells and an alteration in the properties of this attenuated virus which persists even after removal of the antiserum from the culture medium. It is suggested that these in vitro findings could be parallel to the situation that occurs in vivo with measles encephalitis in hamsters and human SSPE.
Cyclic excretion of hepatitis A virus in experimentally infected chimpanzees: Biophysical characterization of the associated HAV particles
Authors: Bradley D. W. , Gravelle C. R. , Cook E. H. , Fields R. M. , Maynard J. E. 
Published: March 2007

AbstractExperimental infection of two chimpanzees with the Phoenix Antigen strain of HAV resulted in the cyclic excretion of virus particles on days 9–11, 14–15, and 20–21 postinoculation. Isopycnic banding in CsCl of stool suspensions prepared from 9–11; 14–15;and 17, 19, 21 dav stool pools revealed multiple buoyant densities for the associated HAV particles. Hollow HAV particles found in the 9–11 day pool banded primarily at a buoyant density of 1.30 g/cm3. HAV in the 14–15 day stool banded bimodally in a CsCl gradient, with antigen peaks at buoyant densities of 1.29 and 1.33 g/cm3. HAV in the days 17, 19, 21 stool pool also banded bimodally in a CsCl gradient; however, the antigen peaks occurred at buoyant densities of 1.33 and 1.40 g/cm3.
Incidence and distribution of herpes simplex virus types 1 and 2 from genital lesions in college women
Authors: Kalinyak Judith E. , Fleagle Genevra , Docherty John J. 
Published: March 2007

AbstractDuring a 9‐month period, 9,772 women were treated at the student health center's gynecology clinic. Herpes simplex virus was isolated from 30 of 57 patients clinically diagnosed as suffering from a herpetic or herpetic‐like genital infection for a virological incidence rate of 0.31%. Using virus plaque diameter in chick embryo cells and heat stability of viral thymidine kinase, 37% of the isolates were classified as herpes simplex virus type 1 and 63% were classified as herpes simplex virus type 2.
Interaction of coxsackievirus B‐3 and peritoneal exudate cells of adult mice treated with cyclophosphamide
Authors: Kabiri M. , Hadaegh M. D. 
Published: March 2007

AbstractInteraction of coxsackievirus B‐3 with peritoneal exudate cells (p.e.c.) of adult mice treated with cyclophosphamide (CP) and of normal untreated mice were examined. The measurement of virus concentration in the supernates and the infective center assay of the virus‐treated p.e.c. showed no significant differences in viral uptake between the p.e.c. of mice treated with CP for 1 and 24 hours, and the cells of normal untreated mice. However, a significant decrease in viral uptake was found in p.e.c. of mice collected 72 hours after treatment with CP. This relationship in viral uptake between the CP‐treated and normal p.e.c. was reversed when the cells were exposed to antimacrophage serum (AMS). The p.e.c. from normal mice exposed to AMS inactivated significantly less virus than similar cells treated with normal rabbit serum. The peritoneal cell‐free fluid of mice treated with CP and coxsackievirus B‐3 for 24 hours, contained less virus than the fluid from mice injected with virus alone. It is therefore concluded that the reduction in viral uptake by the p.e.c. derived from mice 72 hours after CP‐treatment may contribute to the severity of infection in CP‐treated mice.
Multiple buoyant densities of hepatitis A virus in cesium chloride gradients
Authors: Bradley Daniel W. , McCaustland Karen A. , Schreeder Marshall T. , Cook E. H. , Gravelle Clifton R. , Maynard James E. 
Published: March 2007

AbstractHepatitis A virus (HAV) recovered from stools of human cases of hepatitis A and from stools of chimpanzees experimentally infected with HAV was shown to possess multiple buoyant densities in CsCl gradients. The greatest proportion of HAV was most frequently found at a buoyant density of 1.32–1.34 g/cm3, however, large proportions of HAV were also frequently found at higher densities, including 1.36–1.37, 1.40–1.42, and 1.45–1.48 g/cm3. These findings are consistent with the notion that HAV may be a parvovirus.
The isolation of a Bwamba virus variant from man in Western Kenya
Authors: Johnson B. K. , Chanas A. C. , Squires E. J. , Shockley Pauline , Simpson D. I. H. , Smith D. H. 
Published: March 2007

AbstractA Bwamba group virus was isolated from the blood of a febrile child on the Kano Plain, Kenya. The isolate (NY‐45), closely resembling Bwamba, established infection in both Anopheles gambiae and Mansonia uniformis. Neither the Bwamba nor the Pongola prototype strains grew in both species. In gel‐diffusion tests NY‐45 virus passaged through mosquitoes exhibited a line of identity with Pongola antiserum. In contrast no cross‐reaction was observed with NY–45 virus which had not previously been passaged through mosquitoes.
A nonlytic transforming mutant of herpes simplex virus type 2
Authors: Howett Mary K. , Rapp Fred 
Published: March 2007

AbstractA small‐plaque mutant (No. 69) of herpes simplex virus type 2 (HSV‐2) strain 333 has been previously isolated and characterized in this laboratory. This mutant was shown to produce a high ratio of noninfectious to infectious particles when grown at the nonpermissive temperature in hamster embryo fibroblasts [Westmoreland D. and Rapp F. (1976). Journal of Virology 18:92–102]. In this study, we have demonstrated that it is possible to obtain noninfectious stocks of this virus which retain transforming ability in a biochemical transformation assay specific for detection of the HSV gene for thymidine kinase. This mutant contains a DNA genome that has a density identical to the DNA of wildtype virus. Virus and cell DNA synthesis after infection with the mutant at both the permissive and nonpermissive temperature are similar to that observed in cultures infected with the parental virus. Clones of mouse cells biochemically transformed by this virus contain HSV antigens and are presently being examined for oncogenicity.
Prevalence of hepatitis B e antigen and its antibody as detected by radioimmunoassays
Authors: Mushahwar Isa K. , Overby Lacy R. , Frosner G. , Deinhardt Friedrich , Ling Chung‐M. 
Published: March 2007

AbstractA solid‐phase radioimmunoassay (RIA) for the detection of hepatitis B e antigen (HBeAg) and antibody (anti‐HBe) was developed. The RIA was approximately 1,000‐fold more sensitive than rheophoresis for HBeAg, and approximately 6,000‐fold more sensitive than rheophoresis for anti‐HBe. Generally, less than one‐fifth of hepatitis B antigen (HBsAg)‐positive sera from blood donors were positive for either HBeAg or anti‐HBe by rheophoresis; in contrast, more than 90% of the samples were positive by the RIA method. The ratio of HBeAg to anti‐HBe among HBsAg carriers varied in different geographic localities. Also, the presence of HBeAg correlated directly with the titer of HBsAg and the presence of Dane core particles. Anti‐HBe was associated with lower titers of serum HBsAg.
Evaluation of a simplified sucrose gradient method for the detection of rubella‐specific IgM in routine diagnostic practice
Authors: Caul E. O. , Hobbs S. J. , Roberts P. C. , Clarke S. K. R. 
Published: March 2007

AbstractRubella‐specific IgM was measured in a single fraction of serum from a sucrose density gradient. Haemagglutination inhibition (HAI) tests were performed on paired aliquots of the fraction untreated and after treatment with 2‐mercaptoethanol, dilutions of the aliquots being incubated over night with rubella antigen before the addition of red cells. Of 822 sera tested, specific IgM was found in 249, but not in 492. When first tested, the remaining 81 sera gave unsatisfactory results because of contamination of the IgM fraction with IgG (6.0%), probable aggregation of IgG (3.5%), or the persistence of chick red cell agglutinins (0.4%). Tests were performed on 134 patients with rubella confirmed by a rise of HAI antibodies. Rubella‐specific IgM was found at a litre‐of more than eight in the sera taken from 62 of 64 patients between 10 and 29 days after the onset of the rash but in only one of the sera taken between 80 and 119 days, and in none taken later. However, specific IgM was still to be found at lower titre in the sera of 13 patients collected between 80 and 162 days after the onset of the illness. In routine diagnostic tests over three years on the serum from 479 patients with suspected acquired rubella, specific IgM was found at a titre of more than eight in 51 patients and in only 10 instances (2.1%) did a lower level pose a problem in interpretation.
Biochemical and biophysical characterization of light and heavy density hepatitis A virus particles: Evidence HAV is an RNA virus
Authors: Bradley Daniel W. , Fields Howard A. , McCaustland Karen A. , Cook E. H. , Gravelle Clifton R. , Maynard James E. 
Published: March 2007

AbstractHeavy density HAV was also shown to be sensitive to low concentrations of RNase. The results of these biophysical and biochemical studies strongly support the notion HAV is an enterovirus.
Effects of phosphonoacetic acid on subacute myeloopticoneuropathy virus in vitro and in vivo
Authors: Nishibe Y. , Inoue Y. K. 
Published: March 2007

AbstractThe effect of phosphonoacetic acid (PAA) in vitro and in vivo on subacute myeloopticoneuropathy (SMON) virus isolated from the spinal fluid of SMON patients was studied. PAA inhibited multiplication of SMON virus in cultures, but it did not show a direct effect on the virus. The drug did not influence the disease when the medication was started from 10 days after infection of suckling mice. However, the drug did elicit a delay in the incubation period.