bluuebunny/crossref_metadata_2025_split huggingface dataset:
Low-temperature aqueous alteration of crystalline pyrochlore: correspondence between nature and experiment
Authors: Geisler T. , Berndt J. , Meyer H.-W. , Pollok K. , Putnis A. 
Published: January 2005

AbstractPyrochlore has been considered as a waste form to immobilize high-level nuclear waste such as excess weapons-grade plutonium. In order to study the aqueous stability of pyrochlore, we have carried out hydrothermal experiments with a natural microlite (Nb + Ta > 2Ti; Ta ⩾ Nb) at 175°C in a neutral and acidic solution for 14 days. The starting material and the experimental products were studied by electron microprobe, backscattered electron (BSE) imaging, powder infrared (IR) and micro-Raman spectroscopy, and powder X-ray diffractrometry (XRD). The microlite has small U (∼200 ppm) and Th (∼800 ppm) contents and is crystalline. The hydrothermal treatment in a solution containing l mol/l HCl and l mol/l CaCl2 causes the partial replacement of the microlite (up to ∼10 μm) by a new pyrochlore phase. This new phase is characterized by a larger unit-cell volume and contains a large number of vacancies at the A site (A = Ca, Na) as well as anion vacancies, molecular water, and possibly OH groups. Analyses of the experimental fluid further revealed that U was also selectively lost to the solution. Treatment in pure water did not produce reaction zones detectable by BSE imaging or powder XRD. However, significant spectral changes in powder IR spectra of the reaction product and the detection of Na and Ca in the solution indicate that the microlite has also reacted in pure water. The experimental alteration features bear a remarkable resemblance to those seen in naturally altered microlite samples, suggesting that short-term experimental results can be applied to natural systems and vice versa in order to evaluate the long-term stability of a pyrochlore waste form.
Ore genesis at La Colorada Ag-Zn-Pb deposit in Zacatecas, Mexico
Authors: Chutas N. I. , Sack R. O. 
Published: January 2005

AbstractLa Colorada, in Zacatecas State, Mexico is an epithermal Ag-Zn-Pb system hosted in Mesozoic calcareous sedimentary rocks overlain by Tertiary volcanic rocks. The dominant vein is associated with a fault system that accommodates Tertiary normal and strike-slip faulting. The ore consists of fahlore [(Cu,Ag)10(Zn,Fe)2(Sb,As)4S13], polybasite [(Ag,Cu)16Sb2S11]–pearceite [(Ag,Cu)16As2S11] solid solution, pyrargyrite [Ag3SbS3]–proustite [Ag3AsS3] solid solution, acanthite-argentite [Ag2S], and native silver; associated sulphides include galena, sphalerite, chalcopyrite and pyrite. The Ag:Sb of the bulk concentrate from the mine is 1.076 and the Ag:Pb is 0.088. Compositions of the assemblages fahlore + pyrargyrite-proustite + sphalerite, and fahlore + polybasite-pearceite solid solution + (Ag,Cu)2S solid solution + sphalerite encapsulated in quartz and sphalerite indicate a primary depositional temperature of ∼325°C for a depth between 725 and 960 m below the inferred palaeosurface, which is in accord with fluid-inclusion data for higher elevations in the mine.
Surface expression, single-channel analysis and membrane topology of recombinant Chlamydia trachomatis Major Outer Membrane Protein
Authors: Findlay Heather E , McClafferty Heather , Ashley Richard H 
Published: January 2005

Abstract
Background
Chlamydial bacteria are obligate intracellular pathogens containing a cysteine-rich porin (Major Outer Membrane Protein, MOMP) with important structural and, in many species, immunity-related roles. MOMP forms extensive disulphide bonds with other chlamydial proteins, and is difficult to purify. Leaderless, recombinant MOMPs expressed in E. coli have yet to be refolded from inclusion bodies, and although leadered MOMP can be expressed in E. coli cells, it often misfolds and aggregates. We aimed to improve the surface expression of correctly folded MOMP to investigate the membrane topology of the protein, and provide a system to display native and modified MOMP epitopes.

Results
C. trachomatis MOMP was expressed on the surface of E. coli cells (including "porin knockout" cells) after optimizing leader sequence, temperature and medium composition, and the protein was functionally reconstituted at the single-channel level to confirm it was folded correctly. Recombinant MOMP formed oligomers even in the absence of its 9 cysteine residues, and the unmodified protein also formed inter- and intra-subunit disulphide bonds. Its topology was modeled as a (16-stranded) β-barrel, and specific structural predictions were tested by removing each of the four putative surface-exposed loops corresponding to highly immunogenic variable sequence (VS) domains, and one or two of the putative transmembrane strands. The deletion of predicted external loops did not prevent folding and incorporation of MOMP into the E. coli outer membrane, in contrast to the removal of predicted transmembrane strands.

Conclusions
C. trachomatis MOMP was functionally expressed on the surface of E. coli cells under newly optimized conditions. Tests of its predicted membrane topology were consistent with β-barrel oligomers in which major immunogenic regions are displayed on surface-exposed loops. Functional surface expression, coupled with improved understanding of MOMP's topology, could provide modified antigens for immunological studies and vaccination, including live subunit vaccines, and might be useful to co-express MOMP with other chlamydial membrane proteins.
Survey of general practitioners' knowledge about Helicobacter pylori infection
Authors: Canbaz Sevgi , Sunter Ahmet Tevfik , Peksen Yildiz , Leblebicioglu Hakan 
Published: January 2005

Abstract
Background
Helicobacter pylori, occurring throughout the world and causing gastroduodenal diseases, is one of the most common chronic bacterial agents in humans. The purpose of this study was to measure the general practitioners' (GPs) knowledge and practices pertaining to H. pylori infection.

Methods
A cross-sectional type questionnaire survey was conducted in all of 19 primary health care centres (PHCC) in Samsun, Turkey, between November 1 and December 31, 2003. The questionnaire was sent to 124 GPs and 109 (87.9 %) of those filled in. They were requested to answer the questions on the knowledge, sources of medical information, diagnostic tests and treatment to H. pylori.

Results
Medical journals were the most frequently used source of information on H. pylori, being cited by 86 (78.9%) of GPs. Ninety-two (84.4%) of the GPs reported having used one or more tests and 17 (15.6%) never used any test for the diagnosis of H. pylori infection. Only 9.8% had used stool antigen test for diagnosis. GPs reported that they would prescribe symptomatic treatment without ordering diagnostic tests for 29 (26.6%). 54.1% of the GPs explain that they sent patients with H. pylori infection to a specialist, and most used a triple drug regimen containing a PPI. Treatment duration varies between 7 to 28 days. 80.7 of the GPs treat patients for 14 days.

Conclusion
GPs may not have enough knowledge about the importance of stool antigen test or possibility of usage of this test. GPs have not sufficient knowledge about the difference between symptomatic and asymptomatic individuals. It is thought that GPs preferred to treat the patients with suspected ulcer empirically or to send them to a specialist because of the limited diagnostic conditions. The efforts to educate the GPs about the algorithms regarding the management of H. pylori infection during post-graduation period should be improved in PHCCs.
Human cytomegalovirus plasmid-based amplicon vector system for gene therapy
Authors: Mahmood Kutubuddin , Prichard Mark N , Duke Gregory M , Kemble George W , Spaete Richard R 
Published: January 2005

AbstractWe have constructed and evaluated the utility of a helper-dependent virus vector system that is derived from Human Cytomegalovirus (HCMV). This vector is based on the herpes simplex virus (HSV) amplicon system and contains the HCMV orthologs of the two cis-acting functions required for replication and packaging of HSV genomes, the complex HCMV viral DNA replication origin (oriLyt), and the cleavage packaging signal (the a sequence). The HCMV amplicon vector replicated independently and was packaged into infectious virions in the presence of helper virus. This vector is capable of delivering and expressing foreign genes in infected cells including progenitor cells such as human CD34+ cells. Packaged defective viral genomes were passaged serially in fibroblasts and could be detected at passage 3; however, the copy number appeared to diminish upon serial passage. The HCMV amplicon offers an alternative vector strategy useful for gene(s) delivery to cells of the hematopoietic lineage.
In memoriam: Celso-Ramon Garcia, M.D. (1922–2004), reproductive medicine visionary
Authors: Strauss Jerome F , Mastroianni Luigi 
Published: January 2005

Abstract

This article traces the career of Celso-Ramon Garcia (1922–2004), noted physician, educator, and internationally renowned pioneer in the field of reproductive endocrinology. His work helped to formulate oral contraceptives used by millions of women throughout the world. Garcia's research collaborators included Gregory Pincus and John Rock, who together finalized the landmark clinical data needed to secure initial FDA approval for "the pill" in 1960. In addition to Garcia's monumental work in contraceptive endocrinology, his scholarly interests encompassed physiology of the menopause, minimally invasive reproductive surgery, as well as psychological aspects of infertility. Closely identified with the University of Pennsylvania, Garcia was instrumental in establishing the first formal clinical program in reproductive biology and influenced countless young scientists whose training he supervised and mentored. His distinguished career was emblematic of the best of the medical profession, characterized by compassion, intellect, and a sincere desire to help others. Our manuscript outlines Garcia's wide range of interests, acknowledges his superior fund of knowledge, and honors his humanitarian spirit – all of which contributed to an impressive legacy of medical discoveries. The impact of Prof. Garcia's work will continue to be felt for many years.
Long-term prognostic significance of HER-2/neu in untreated node-negative breast cancer depends on the method of testing
Authors: Schmidt Marcus , Lewark Barbara , Kohlschmidt Nikolai , Glawatz Christiane , Steiner Erik , Tanner Berno , Pilch Henryk , Weikel Wolfgang , Kölbl Heinz , Lehr Hans-Anton 
Published: January 2005

Abstract
Introduction
The prognostic significance of HER-2/neu in breast cancer is a matter of controversy. We have performed a study in 101 node-negative breast cancer patients with long-term follow-up not treated in the adjuvant setting, and analysed the prognostic significance of immunohistochemistry (IHC) and fluorescence in situ hybridisation (FISH), both separately and in combination, in comparison with traditional prognostic factors.

Methods
Overexpression was classified semiquantitatively according to a score (0 to 3+) (HER-2_SCO). FISH was used to analyse HER2/neu amplification (HER-2_AMP). Patients classified 2+ by IHC were examined with FISH for amplification (HER-2_ALG). Patients with 3+ overexpression as well as amplification of HER-2/neu were positive for the combined variable HER2_COM. These variables were compared with tumour size, histological grade and hormone receptor status.

Results
HER-2_SCO was 3+ in 20% of all tumours. HER-2_ALG was positive in 22% and amplification (HER-2_AMP) was found in 17% of all tumours. Eleven percent of the tumours showed simultaneous 3+ overexpression and amplification. Only histological grade (relative risk [RR] 3.22, 95% confidence interval [CI] 1.73–5.99, P = 0.0002) and HER-2_AMP (RR 2.47, 95% CI 1.12–5.48, P = 0.026) were significant for disease-free survival in multivariate analysis. For overall survival, both histological grade (RR 3.89, 95% CI 1.77–8.55, P = 0.0007) and HER-2_AMP (RR 3.08, 95% CI 1.24–7.66, P = 0.016) retained their independent significance.

Conclusion
The prognostic significance of HER-2/neu in node-negative breast cancer depends on the method of testing: only the amplification of HER-2/neu is an independent prognostic factor for the long-term prognosis of untreated node-negative breast cancer.
Practice of sedation and analgesia in German intensive care units: results of a national survey
Authors: Martin Jörg , Parsch Axel , Franck Martin , Wernecke Klaus D , Fischer Matthias , Spies Claudia 
Published: January 2005

Abstract
Introduction
Sedation and analgesia are provided by using different agents and techniques in different countries. The goal is to achieve early spontaneous breathing and to obtain an awake and cooperative pain-free patient. It was the aim of this study to conduct a survey of the agents and techniques used for analgesia and sedation in intensive care units in Germany.

Methods
A survey was sent by mail to 261 hospitals in Germany. The anesthesiologists running the intensive care unit were asked to fill in the structured questionnaire about their use of sedation and analgesia.

Results
A total of 220 (84%) questionnaires were completed and returned. The RAMSAY sedation scale was used in 8% of the hospitals. A written policy was available in 21% of hospitals. For short-term sedation in most hospitals, propofol was used in combination with sufentanil or fentanyl. For long-term sedation, midazolam/fentanyl was preferred. Clonidine was a common part of up to two-thirds of the regimens. Epidural analgesia was used in up to 68%. Neuromuscular blocking agents were no longer used.

Conclusion
In contrast to the US 'Clinical practice guidelines for the sustained use of sedatives and analgesics in the critically ill adult', our survey showed that in Germany different agents, and frequently neuroaxial techniques, were used.
ZnO Microspheres Self-assembled by Hexagonal Nanoplates
Authors: Wang Huihu , Xie Changsheng , Zeng Dawen 
Published: January 2005

Abstract
Because of the polar growth manner ZnO of different shapes has been synthesized. However, the isotropic shapes of ZnO have not reported yet. In this paper, the novel ZnO microspheres were synthesized by the complex system in which starting reagents, Zn(AC)2, H2O, and HMT, were kept in methanol solution at 60 °C for 12 h. The FE-SEM images and XRD pattern results show that the microspheres are formed by ZnO nanoplates that align in a regular periodicity via self-assembly. The formation mechanism of this nanostructure was discussed briefly.
Strong Base Catalysis of Sulfated Mesoporous Alumina for the Tishchenko Reaction in Supercritical Carbon Dioxide
Authors: Seki Tsunetake , Onaka Makoto 
Published: January 2005

Abstract
Heterogeneous strong base catalysis for the Tishchenko reaction in acidic scCO2 solvent has been realized with mesoporous alumina modified with SO42−, while a conventional solid base like CaO showed almost no catalytic performance in scCO2.
Very Short and Efficient Syntheses of the Spermine Alkaloid Kukoamine A and Analogs Using Isolable Succinimidyl Cinnamates
Authors: Garnelis Thomas , Athanassopoulos Constantinos M , Papaioannou Dionissios , Eggleston Ian M , Fairlamb Alan H 
Published: January 2005

Abstract
Direct selective acylation of the primary amino functions of spermine and spermidine with a variety of isolable succinimidyl cinnamates, followed by catalytic hydrogenation, gave high yields of the spermine alkaloid kukoamine A and analogs suitable for structure-activity relationship studies. Suitable succinimidyl cinnamates were readily obtained through Wittig reaction of aromatic aldehydes with the ylides Ph3P=CRCO2Me, followed by saponification and activation with N-hydroxysuccinimide in the presence of N,N′-dicyclohexylcarbodiimide.
Electron Beam-Induced Fries Rearrangement of Sulfonamide and Sulfonate Crystals
Authors: Kato Jun , Maekawa Yasunari , Yoshida Masaru 
Published: January 2005

Abstract
The electron beam (EB) sensitivity of sulfonic acid derivatives in the crystalline state was much higher than that of the corresponding carboxylic acid derivatives, which was distinct from the results using other energy sources such as heat and UV; especially, sulfonamide derivatives could undergo the chemoselective Fries rearrangement to give ortho and para products in the ratio of ca. 7/3 without the meta isomer.
Direct Addition of Glycine Derivatives to Enamines
Authors: Kobayashi Jun , Yamashita Yasuhiro , Kobayashi Shu 
Published: January 2005

Abstract
Direct addition of glycine derivatives to enamines proceeded smoothly in the presence of a catalytic amount of a Lewis acid to afford the corresponding α,β-diamino acid derivatives in excellent yields. In this reaction, enamines would initially act as a base and subsequently as a C=N electrophile. This is the first example of Mannich-type reactions using enamines as imine equivalents.
Barotropic Phase Transitions of 1-Palmitoyl-2-stearoylphosphatidylcholine Bilayer Membrane
Authors: Matsuki Hitoshi , Goto Masaki , Kusube Masataka , Tamai Nobutake , Kaneshina Shoji 
Published: January 2005

Abstract
The barotropic phase transitions of an asymmetric phosphatidylcholine, 1-palmitoyl-2-stearoylphosphatidylcholine (PSPC), bilayer membrane were observed by the methods of high-pressure light transmittance and differential scanning calorimetry. The temperature–pressure phase diagram and thermodynamic quantities of the phase transitions were compared with those of three kinds of symmetric phosphatidylcholines. The different transition properties of PSPC bilayer from those of symmetric phosphatidylcholines may be attributable to the enhanced cohesive interaction between acyl chains in the gel state of the bilayer membrane.
Effect of Lipid-Lowering Drug Therapy on Small-Dense Low-Density Lipoprotein
Authors: Backes James M , Gibson Cheryl A 
Published: January 2005

OBJECTIVE: To review the effects of lipid-lowering therapy on small-dense low-density lipoprotein cholesterol (sdLDL-C). DATA SOURCES: Literature was obtained from MEDLINE (1989–September 2004) and references of selected articles. Key search terms included small-dense LDL-C and lipid-lowering drug therapy. DATA SYNTHESIS: Statins, fibrates, and niacin have demonstrated favorable effects on sdLDL-C, especially among patients with mixed dyslipidemia or hypertriglyceridemia. These effects include a reduction of sdLDL-C and/or a shift to the larger, less atherogenic LDL-C. CONCLUSIONS: Data suggest that statins, fibrates, and niacin are effective at reducing concentrations of sdLDL-C and possibly normalizing LDL-C subclasses.
State-Funded Comprehensive Primary Medical Care Service Programs for Medically Underserved Populations: 1995 vs 2000
Authors: Wilensky Sara , Rosenbaum Sara , Hawkins Dan , Mizeur Heather 
Published: January 2005

Objectives. We analyzed responses to the 2000 Comprehensive Primary Medical Care programs for Medically Underserved Populations Survey and compared them with the 1995 survey results to identify trends. Methods. Surveys were mailed to all primary care program offices. State primary care program associations reviewed primary care program offices’ responses and completed surveys for offices that did not respond. Results. We identified 30 qualified primary care programs in 24 states that had an overall funding level of $215 million. Most states allowed funds to be spent on expanding service areas, buying equipment, and hiring and training staff. Conclusions. Although state funding has increased overall, many states do not have comprehensive primary care programs, and an increasing number of states are experiencing budget deficits that may lead to reductions in existing programs.
Barriers to Medicaid Enrollment: Who Is at Risk?
Authors: Stuber Jennifer , Bradley Elizabeth 
Published: January 2005

Objectives. We identified factors associated with levels of knowledge about Medicaid eligibility rules and perceived Medicaid enrollment barriers. Methods. Community health center patients who were parents of children potentially eligible for Medicaid (n=901) were interviewed in person during their clinic visit between April and December 1999. Results. Individuals reporting physical health problems were more likely to be misinformed as were non-Hispanic Black individuals, compared with non-Hispanic White individuals. In states where more policies had been enacted to simplify Medicaid enrollment procedures, individuals were less likely to be misinformed. Individuals reporting mental health problems, those with less education, and women were more likely to perceive Medicaid enrollment barriers. Prior experience in Medicaid was associated with both a reduced risk of perceiving Medicaid enrollment barriers and being misinformed. Conclusions. Findings highlight target groups for whom additional outreach and additional simplification policies may be most needed.
Welfare Reform and Health Insurance: Consequences for Parents
Authors: Holl Jane L. , Slack Kristen Shook , Stevens Amy Bush 
Published: January 2005

Objectives. We assessed the relation between the work promotion, welfare reduction, and marriage goals of welfare reform and the stability of health insurance of parents in transition from welfare to work. Methods. We analyzed a panel survey (1999–2002) of a stratified random sample of Illinois families receiving welfare in 1998 (n=1363). Results. Medicaid remains the foremost source of health insurance despite a significant decline in the proportion of parents with Medicaid. Regardless of work/welfare status in year 1, transitioning to work only or no work/no welfare increased the likelihood of having unstable health insurance in years 2 and 3 compared with those who remained on welfare only. Conclusions. Parents who meet the welfare reform goals of work promotion and reduction of welfare dependence experience significant loss and instability of health insurance.
A Community-Based Intervention Designed to Increase Preventive Health Care Seeking Among Adolescents: The Gonorrhea Community Action Project
Authors: VanDevanter Nancy L. , Messeri Peter , Middlestadt Susan E. , Bleakley Amy , Merzel Cheryl R. , Hogben Matthew , Ledsky Rebecca , Malotte C. Kevin , Cohall Renee M. , Gift Thomas L. , St. Lawrence Janet S. 
Published: January 2005

Objectives. We evaluated the effectiveness of an intervention designed to increase preventive health care seeking among adolescents. Methods. Adolescents and young adults aged 12 to 21 years, recruited from community-based organizations in 2 different communities, were randomized into either a 3-session intervention or a control condition. We estimated outcomes from 3-month follow-up data using logistic and ordinary least squares regression. Results. Female intervention participants were significantly more likely than female control participants to have scheduled a health care appointment (odds ratio [OR]=3.04), undergone a checkup (OR=2.87), and discussed with friends or family members the importance of undergoing a checkup (OR=4.5). There were no differences between male intervention and male control participants in terms of outcomes. Conclusions. This theory-driven, community-based group intervention significantly increased preventive health care seeking among female adolescents. Further research is needed, however, to identify interventions that will produce successful outcomes among male adolescents.