bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conditional probability amplitudes in wave mechanics
Authors: Hunter Geoffrey 
Published: December 2004

AbstractThe total wave function of a system ψ(x, y) is expressed as a product of a marginal amplitude function f(y) and a conditional amplitude function ϕ(x | y). The original Schrödinger equation Hψ = Eψ is reduced to a Schrödinger equation for the marginal amplitude H′f = Ef. The factorization of ψ is in principle exact. It achieves a partial separation of the variables x and y.
Computation of Fourier transform quantities in Hartree–Fock calculations for simple crystals
Authors: Graovac Ante , Monkhorst Hendrik J. , Glasser M. L. 
Published: December 2004

AbstractAn efficient method is presented to compute the Fourier transforms of lattice sums over Slater‐type orbital products that arise in crystal Hartree–Fock calculations. Introduction of one‐dimensional integral representations for the Fourier transforms of the STO'S enables a separation of the three infinite sums under the (two‐dimensional) integral sign. This, in turn, makes it possible to calculate and store quantities associated with the three Fourier transform vector components separately. The orbital transform integrations are then performed numerically. The method is very advantageous when lattice sum transforms are needed for a large number of transform vectors. Formulas and results are presented for simple‐cubic crystals when 1s, 2s, and 2p Slater orbitals are involved.
The use of partitioning technique in the solution of operator equations for ionizations and excitations
Authors: Nerbrant Per‐Olof 
Published: December 2004

AbstractAn inhomogeneous operator equation is associated with the equations of motion for ionization‐ and excitation operators. The partitioning technique is applied to solve the equation. Formal expressions for the ionization‐ and excitation operators are obtained and examples of approximations to these are given.
Errors in the calculations of first‐order and second‐order energy perturbations
Authors: Hameka Hendrik F. , Svendsen E. Nørby 
Published: December 2004

AbstractWe consider the calculation of first‐order and second‐order atomic and molecular properties from approximate ground‐state wave‐functions by using variational procedures for solving the first‐ and second‐order perturbation equations. We evaluate the errors in the final results due to the error in the unperturbed wave‐function and to the errors caused by the approximations in solving the perturbation equations. By combining slightly different results we can eliminate all first‐order errors. Our analysis covers situations where perturbation expansions of the error in the ground‐state wave‐function are not feasible and it includes the effects due to approximations in solving the perturbation equations.
The spin‐density‐functional formalism for quantum mechanical calculations: Test on diatomic molecules with an efficient numerical method
Authors: Gunnarsson O. , Johansson P. 
Published: December 2004

AbstractWe have applied the spin‐density‐functional (SDF) formalism with the local‐spin‐density (LSD) approximation to a number of small molecules with the primary aim of testing the approximation for molecular applications. A new numerical method to solve the one‐electron wave equation is developed, utilizing the special features of the SDF formalism. We have calculated energy curves, dissociation energies, and equilibrium distances for some diatomic molecules [H (2Σ, 2Σ), H2(1Σ, 3Σ), He (1Σ), and He2(1Σ)] and the vibrational frequencies of H2. The deviations from the experimental results are typically 1/2 eV for the energies and ≤ 0.1 Å for the distances. We discuss the LSD approximation using the concept of an exchange‐correlation hole and make predictions about the applicability to other molecules. The LSD approximation is compared with the Hartree‐Fock and multiple‐scattering‐Xα methods and some difficulties in the latter methods are pointed out. It is argued that the SDF formalism within the LSD approximation has physical advantages compared to the Hartree‐Fock and Xα methods and that it should provide a simple and useful method for a broad range of applications.
Spin‐Extended Hartree–Fock calculation for hydrocarbon π‐radicals
Authors: Klimo Viliam , TiňO Jozef 
Published: December 2004

AbstractAn iterative method of solving the Mestechkin spin‐extended Hartree–Fock equations is proposed. On this basis projected and spin‐extended values of energies and spin densities for some hydrocarbon π‐radicals are calculated. Relations among UHF, ASA, AA, projected, and spin‐extended energies are discussed.
Calculations of electric dipole polarizabilities of polyatomic molecules
Authors: Lazzeretti Paolo , Cadioli Beniamino , Pincelli Ugo 
Published: December 2004

AbstractCoupled and uncoupled Hartree–Fock theories are used to compute the electric dipole polarizability of water, ammonia, and methane with three different GTO basis sets. Bounds for the geometric approximation to uncoupled polarizabilities are also computed to examine the accuracy of calculated values. The results are compared with those obtained by a variational‐perturbation method proposed by Rebane. The numerical tests provide some information on the correlation terms affecting total computed polarizabilities. The computed values are shown to be in fair or good agreement with experimental data for the largest basis sets. The reliability of Rebane's method with respect to coupled HF procedure is also discussed.
I. Lineare Fehlerminimisierung Ein Verfahren zur Eigenwertberechnung bei Schrödinger‐Operatoren
Authors: Kleindienst H. , Altmann W. 
Published: December 2004

AbstractA variational principle is derived from the spectral theorem of self‐adjoint operators. The principle allows to calculate simultaneously upper and lower bounds for each point of the spectrum. For Schrödinger operators this method of error minimization is reduced to a series of matrix diagonalizations using an iterative process and is linearized in this way. The convergence of this method and the equivalence with the nonlinear problem of variation are proven.
II. Eigenwertberechnung beim Dreikörperproblem
Authors: Kleindienst H. , Baumgarten E. , Altmann W. 
Published: December 2004

AbstractThe convergence and the quality of approximation of the variational method developed in part I are tested using the He atom as an example. For the three‐body problem the inner products and the norms were explicity expressed as functions of the optimization parameters. The method permits calculation of upper and lower bounds for the ground state of helium.
The instabilities of the Hartree–Fock solutions and the lattice instabilities for conjugated hydrocarbons: The bond‐order and bond‐length alternations
Authors: Toyota A. , Tanaka T. , Nakajima T. 
Published: December 2004

AbstractThe instabilities, especially the singlet instabilities, of the conventional Hartree–Fock (HF) solutions for a variety of alternant and nonalternant hydrocarbons, some of which have been known to show lattice instabilities (bond‐length alterations), are examined. The HF solutions for nonalternant hydrocarbons in the pentalene series larger than heptalene and [4n + 2]‐annulenes larger than C22H22 are found to be singlet unstable and there appear new solutions lower in energy than the conventional HF solutions and characterized by charge‐density waves exhibiting bond‐order alterations. It is found that such symmetry‐breaking solutions are energetically further stabilized by distorting the nuclear framework so that it may match up with the distribution of bond‐order matrix elements of the charge‐density wave, which means that in conjugated systems the singlet instability of the HF solution is always accompanied with the lattice instability. Further, it is shown that in conjugated systems, even when the HF solution is singlet stable, if it is not sufficiently stable as, for example, in pentalene and heptalene, there is every possibility for the occurrence of lattice instability. It is also shown that the singlet instability as well as the lattice instability arises from the existence of a sufficiently low‐lying singlet excited state.
Marine biogeography of southern Australia: phylogeographical structure in a temperate sea‐star
Authors: Waters Jonathan M. , Roy Michael S. 
Published: December 2004

AbstractAim  To test whether marine biogeographical patterns observed at the community level are also important within species. It is postulated that historical hydrogeographic barriers have driven in situ diversification.Location  The intertidal and shallow subtidal zones of southern Australia, New Zealand and nearby islands. Australia's temperate marine communities are characterized by a high degree of endemism and show strong biogeographical structure along an east–west axis.Methods  Phylogeographical analysis of the widespread asteriid sea‐star Coscinasterias muricata Verrill across southern Australia and New Zealand. Forty‐two samples from 27 locations were included in phylogenetic analyses of mitochondrial (CO1; control region) and nuclear (ITS2) DNA sequences.Results  Analysis of mtDNA revealed a deep phylogenetic split within Australian C. muricata, strongly correlated with latitude. ‘Northern’ haplotypes (latitude ≤ 37.6° S, nine sites, 15 samples) were 7.3–9.4% divergent from ‘southern’ haplotypes (latitude ≥ 37.6° S, 19 sites, 27 samples), consistent with late Pliocene separation. Eastern and western representatives of the ‘northern’ clade were 0.5–1.0% divergent, probably reflecting Pleistocene isolation. The ‘southern’ clade of Australia is also represented in New Zealand, indicating Pleistocene oceanic dispersal. Nuclear DNA (ITS2) sequences yielded relatively little phylogenetic resolution, but were generally congruent with mtDNA‐based groupings.Main conclusions  The phylogeographical pattern detected within Australian C. muricata closely resembles marine biogeographical groupings proposed on the basis of community and species distributions. Recurring evolutionary patterns may have been driven by the hydrographic history of southern Australia. Specifically, we suggest that Plio‐Pleistocene temperature change and the repeated opening and closure of Bass Strait promoted allopatric divergence and perhaps cryptic speciation in C. muricata.
Central venous catheter dressings: a systematic review
Authors: Gillies Donna , O'Riordan Elizabeth , Carr Debbie , O'Brien Ida , Frost Judy , Gunning Robbie 
Published: December 2004

Background.  Gauze and tape or transparent polyurethane film dressings such as Tegaderm®, Opsite® or Opsite IV3000® are the most common types of dressing used to secure central venous catheters (CVCs). Currently, there are no clear guidelines as to which type of dressing is the most appropriate.Aims.  To identify whether there are any differences between gauze and tape and/or transparent polyurethane film dressings in the incidence of CVC‐related infection, catheter‐related sepsis, catheter security, tolerance to dressing material, dressing condition and ease of application in hospitalized patients.Methods.  The Cochrane Controlled Trials Register and Medline, Embase and CancerLit databases were searched to identify any controlled trials comparing the effects of gauze and tape and/or transparent polyurethane dressings on CVCs. Additional references were sought from published and non‐published literature. Twenty‐three studies were reviewed. Data were extracted independently from each paper by two members of the review team and results compared. Differences were resolved either by consensus or referral to a third person. Authors were contacted for missing information.Results.  Of the 23 studies reviewed, 15 were excluded. Of the remaining eight, data were available for meta‐analysis from six studies. Of the six included studies, two compared gauze and tape with Opsite IV3000, two compared Opsite with Opsite IV3000, one compared Tegaderm with Opsite IV3000, and one compared Tegaderm with Opsite.Conclusions.  There was no evidence of any difference in the incidence of infectious complications between any of the dressing types compared in this review. Each of these comparisons was based on no more than two studies and all of these studies reported data from a small patient sample. Therefore it is unlikely that any of these comparisons would have had sufficient power to detect any differences between groups.
Workplace stress in nursing: a literature review
Authors: McVicar Andrew 
Published: December 2004

Background.  Stress perception is highly subjective, and so the complexity of nursing practice may result in variation between nurses in their identification of sources of stress, especially when the workplace and roles of nurses are changing, as is currently occurring in the United Kingdom health service. This could have implications for measures being introduced to address problems of stress in nursing.Aims.  To identify nurses’ perceptions of workplace stress, consider the potential effectiveness of initiatives to reduce distress, and identify directions for future research.Method.  A literature search from January 1985 to April 2003 was conducted using the key words nursing, stress, distress, stress management, job satisfaction, staff turnover and coping to identify research on sources of stress in adult and child care nursing. Recent (post‐1997) United Kingdom Department of Health documents and literature about the views of practitioners was also consulted.Findings.  Workload, leadership/management style, professional conflict and emotional cost of caring have been the main sources of distress for nurses for many years, but there is disagreement as to the magnitude of their impact. Lack of reward and shiftworking may also now be displacing some of the other issues in order of ranking. Organizational interventions are targeted at most but not all of these sources, and their effectiveness is likely to be limited, at least in the short to medium term. Individuals must be supported better, but this is hindered by lack of understanding of how sources of stress vary between different practice areas, lack of predictive power of assessment tools, and a lack of understanding of how personal and workplace factors interact.Conclusions.  Stress intervention measures should focus on stress prevention for individuals as well as tackling organizational issues. Achieving this will require further comparative studies, and new tools to evaluate the intensity of individual distress.
Prostate mucinous adenocarcinoma with signet ring cell
Authors: GUMUS EYUP , YILMAZ BANU , MIROGLU CENGIZ 
Published: December 2004

AbstractProstate mucinous adenocarcinoma with signet ring cell is a rare neoplasm with only 11 cases reported to date. We present the 12th case of prostate mucinous adenocarcinoma with signet ring cell. The case was detected incidentally as a result of a biopsy taken from a lesion in the prostatic urethra during a urethrocystoscopy of a 47‐year‐old male patient who underwent an internal urethrotomy operation due to urethrostenosis. Endoscopic examination showed a loose, spongy, gray–white structure covering the prostatic urethra, especially the right lobe of the prostate. The diagnosis resulting from the pathological examination of the biopsy was prostate mucinous adenocarcinoma with signet ring cell. A total of 50 Gy radiotherapy was applied to the patient. In the 27th month of follow‐up after treatment, thoracoabdominal computed tomography, bone scintigraphy, and tumor markers (PSA, CEA and CA19‐9) were found to be normal.
Combined effect of clarithromycin and imipenem/cilastatin against urinary biofilm infection after pyeloplasty
Authors: FURUHATA MASAYUKI , IWAMURA MASATSUGU , BABA SHIRO , INOUE MATSUHISA 
Published: December 2004

AbstractThe present report concerns a 38‐year‐old man, who had been treated with pyeloplasty and lithotomy for the improvement of urinary excretion and resolution of a kidney stone. The patient developed a biofilm infection involving Pseudomonas aeruginosa and Staphylococcus epidermidis, and had been suffering from recurrent acute pyelonephritis for one year. Combination therapy with clarithromycin (CAM) and imipenem/cilastatin (IMP/CS) consisted of administration of CAM at a dose of 400 mg/day for 1 week, followed by 500 mg/day of IMP by intravenous infusion combined with CAM (400 mg/day) for 5 days. This therapy produced an immediate antimicrobial effect and no further signs of pyuria have been seen during one year of follow‐up in this patient.
Unusual case of post‐cesarean vesicouterine fistula (Youssef's syndrome)
Authors: KILINC FERHAT , BAGIS TAYFUN , GUVEL SEZGIN , EGILMEZ TULGA , OZKARDES HAKAN 
Published: December 2004

AbstractVesicouterine fistula without vaginal leakage of urine, cyclic hematuria and amenorrhea is a rare condition, referred to as Youssef's syndrome. The most common cause of this syndrome is trauma during a cesarean section. Herein a new case is reported.
Delayed recovery of urinary continence after laparoscopic radical prostatectomy
Authors: EGAWA SHIN , KURUMA HIDETOSHI , SUYAMA KAZUHO , IWAMURA MASATSUGU , BABA SHIRO 
Published: December 2004

AbstractAim: To study the rate at which patients regained urinary continence during our institution's early experience with laparoscopic radical prostatectomy.Methods: The urinary continence of 34 patients was recorded at various intervals following laparoscopic radical prostatectomy. These data were compared with those from 49 patients who had undergone radical retropubic prostatectomy.Results: For laparoscopic prostatectomy patients, 2.9% had regained urinary continence at 1 month, 29.4% at 3 months, 46.9% at 6 months, 56.0% at 9 months and 60.0% at 12 months. For retropubic prostatectomy patients, the corresponding rates were 22.4% at 1 month, 63.3% at 3 months, 84.1% at 6 months, 92.9% at 9 months and 92.9% at 12 months. Backward stepwise logistic regression analysis indicated that laparoscopic surgery itself significantly predicted urinary incontinence at every interval from 1 to 9 months following surgery (P < 0.05).Conclusion: Patients’ postoperative recovery of urinary continence was not satisfactory in our early experience with laparoscopic radical prostatectomy. Further efforts to elucidate the reason for this poor functional outcome are mandatory before the procedure is accepted as part of standard practice.
Transitional cell carcinoma in an ectopic ureter
Authors: NARITA SHINTARO , AKAO TOSHIYA , TSUCHIYA NORIHIKO , KUMAZAWA TERUAKI , KAKINUMA HIDEAKI , SATOH SHIGERU , SATO KAZUNARI , HABUCHI TOMONORI , KATO TETSURO 
Published: December 2004

AbstractWe experienced an 82‐year‐old man with transitional cell carcinoma in an ectopic ureter draining into the prostatic urethra. Carcinoma arising from an ectopic ureter is very rare and a differential diagnosis is difficult. To our knowledge, our case is the third male case reported in the literature.
Soil Organic Carbon Build‐up and Dynamics in Rice–Rice Cropping Systems
Authors: Ramesh K. , Chandrasekaran B. 
Published: December 2004

AbstractIntensive irrigated rice system is the most important food production system in the world. Continued population growth necessitates increased rice production to meet the increased need of food production through increased rice productivity to ensure food security. In contrast, the recent slowdown in yield growth in intensive irrigated rice‐based cropping systems as a result of deterioration of soil health and decline in productivity level is a serious cause for concern. The objective of this research was to investigate the soil organic carbon (SOC) build‐up and its dynamics in rice–rice cropping system by including a green manure (GM) crop Sesbania rostrata Berm. either during fallow and/or intercrop at 4 : 1 ratio as additive series without changing rice geometry. The results revealed that there is a gradual build‐up of SOC when S. rostrata included and in situ incorporated at flowering stage as a basic means of improving soil quality in rice–rice cropping system. Further, the soil organic matter fractions viz. humic acid and fulvic acid were also improved in all GM‐incorporated systems. In general, the proportion of fulvic acid was higher than humic acid. Cropping system involving three GMs viz. S. rostrata‐rice/S. rostrata‐rice/S. rostrata registered significantly higher SOC and was 10.63 percent higher than traditional rice–rice cropping system (A1). This was followed by S. rostrata‐rice/S. rostrata‐rice system. Although the traditional rice–rice cropping system (A1) also conserved SOC (0.29 and 1.69 % higher than initial during first and second annual cropping cycle, respectively), the magnitude was very low. Repeated application of S. rostrata as GM improved SOC, which formed the basis for sustainable management of soil resources. It can be concluded that S. rostrata would affect the rate of loss of SOC in cropping systems and its ultimate level in soils.
Chemosensory proteins of Locusta migratoria
Authors: Ban L. , Scaloni A. , Brandazza A. , Angeli S. , Zhang L. , Yan Y. , Pelosi Paolo 
Published: December 2004

AbstractTwo different classes of chemosensory proteins (CSPs) in Locusta migratoria have been identified on the basis of the molecular cloning of a series of different cDNAs from the antennae of this insect. Several CSP isoforms have been purified and biochemically characterized from antennal and wing extracts, some of them corresponding to expression products predicted for the identified cDNAs. In wings, the nature of the main endogenous ligand binding to these proteins was determined as oleoamide by a gas chromatography–mass spectrometric approach. One of these isoforms has been expressed in a bacterial system with high yield and used in a fluorescent binding assay. Competitive binding experiments have indicated the presence of long‐chain compounds among the best ligands.
Molecular cloning and expression of the dihydrofolate reductase (DHFR) gene from adult buffalo fly (Haematobia irritans exigua): effects of antifolates
Authors: Elvin C. M. , Liyou N. E. , Pearson R. , Kemp D. H. , Dixon N. E. 
Published: December 2004

AbstractThe folate analogues methotrexate, aminopterin and pyrimethamine were toxic when fed in a blood meal to adult buffalo flies (Haematobia irritans exigua), but aminopterin caused greater mortality than methotrexate, while trimethoprim was not toxic to adult flies. This is the first recorded instance of mortality in adult insects caused by ingestion of folate analogues. In order to investigate the mechanism of this toxicity, the dihydrofolate reductase (DHFR) gene was cloned from adult buffalo fly cDNA using a PCR‐based approach. The full‐length DHFR coding sequence (BF‐DHFR) was 887 bp and contained an open reading frame encoding a protein of 188 amino acids. The deduced protein sequence identities between BF‐DHFR and the other known insect DHFR sequences were: Drosophila melanogaster, 75%; Aedes albopictus, 54%; Heliothis virescens, 43%. The BF‐DHFR gene has a single 52 bp intron, an organization more similar to Dipteran species (Drosophila and Aedes). The cDNA encoding BF‐DHFR was inserted into an Escherichia coli expression vector and the recombinant protein was expressed to levels representing about 25% of total cell protein. The active enzyme was purified by affinity chromatography on methotrexate‐agarose and displayed a relatively low affinity (IC50 = 30 nm) for methotrexate.