bluuebunny/crossref_metadata_2025_split huggingface dataset:
Health authority cervical screening recall policies and time since last smear: a retrospective cohort analysis in the north west of England
Authors: Howe A , Owen-Smith V , Richardson J 
Published: January 2004

Objectives: To evaluate the impact of health authority cervical screening programmes upon the actual screening interval for women attending as a result of routine recall and to assess the impact of general practice recall policies on attendance for smears. Setting: Nine health authorities constituting the Lancashire and Greater Manchester zones of the North West region of the National Health Service. Methods: Information was obtained on the invitation and recall policies of each health authority. A retrospective analysis of information held on cervical screening databases ("Exeter" computer systems) was performed. The proportions of smears, classified by a screening interval of "unscheduled", "on-time", or "overdue", in the different health authority recall programmes were compared. General practices in one health authority (operating five-yearly recall) were contacted to determine their current practice screening policy. Results: Women who were invited as part of a three-yearly recall programme were more likely to attend for smears at intervals of 3-5 years than those on a five-yearly recall programme (68% vs 47%). Those health authorities operating three-yearly recall that issued recall invitations to women more than four weeks before the date the smear was due had higher rates of "unscheduled" smears. In the one health authority (operating a five-yearly recall programme) in which we determined general practice screening policy, 62% of the general practitioners (GPs) were operating their own three-yearly recall policy; these GPs had a higher proportion of the women who attended for smears "on-time" (51%) than did those who relied on the heath authority five-yearly recall procedure (44%). Conclusions: Despite the cervical screening programme being a national programme, there is scope at a local level for considerable variation in the interpretation of national guidance. This variation effects the extent to which programmes comply with the requirement to screen all women at an interval of 3-5 years.
Risk of invasive cervical cancer after three consecutive negative Pap smears
Authors: Coldman A , Phillips N , Kan L , Matisic J , Benedet L , Towers L 
Published: January 2004

Objectives: To determine the factors that influence risk of cervical cancer after three consecutive negative Pap smears. Methods: A cohort study was conducted using data from the British Columbia Cervical Cancer Screening Program and British Columbia Cancer Registry. Analysis was based on a one percent sample of women aged 20-69 years with Pap smears enriched with all invasive cervical cancer cases diagnosed between 1994-99. Screening intervals, after three negative screens, were created with the following variables: age at beginning of interval, interval length, previous cytologic abnormality and previous cervical procedure. The risk of cervical cancer by histologic type was calculated using survival analysis methods. Results: The sample consisted of 10,509 women, who contributed 28,309 intervals, and 371 cervical cancer cases. The incidence rate of invasive squamous cervical cancer increased with time since last screen up to six years. Women with a history of dysplasia remained at elevated risk for squamous cancer, hazard ratio=2.6 (95% confidence interval [CI]=1.9, 3.4) but age or previous procedure were not related to risk. No relationship between time since last screen and non-squamous cancer risk was found although history of a previous procedure was significant. The marginal effectiveness of Pap smears declined with increasing frequency of use. Conclusions: This study confirmed the preventive effect of Pap smear screening and its dependency on frequency of use. Women with a history of dysplasia, prior to three consecutive negatives, were at increased risk of developing invasive squamous cervical cancer compared with women with no such history.
An assessment of smear taker training in the Northern & Yorkshire cervical screening programme
Authors: Faulkner Keith , Greenwood Lesley , Stamp Elaine 
Published: January 2004

Objective: To assess the impact of a regional smear taker training scheme within the Northern and Yorkshire Cervical Screening Programme. Design: An analysis of cervical screening KC activity returns to the Department of Health before and after the introduction of a structured training programme for smear takers. Setting: Northern and Yorkshire Region of England. Subjects: Women participating in cervical screening. Results: The introduction of a region-wide smear taker training programme has resulted in fewer inadequate cervical smears, fewer opportunistic smears and fewer women aged below 20 having cervical smears. The training programme is cost effective. Conclusions: It is recommended that all cervical screening programmes consider the introduction of smear taker training. It is a cost-effective approach to running the cervical screening programme.
Screening for liver cancer: results of a randomised controlled trial in Qidong, China
Authors: Chen J-G , Parkin D M , Chen Q-G , Lu J-H , Shen Q-J , Zhang B-C , Zhu Y-R 
Published: January 2004

Objectives: To investigate the effectiveness of screening for liver cancer in reducing mortality from the disease in a high-risk population in China. Setting: A randomised controlled trial was carried out among men aged 30-69 who were chronic carriers of hepatitis-B virus (HBsAg positive) during the period 1989-1995 in Qidong county, Jiangsu Province, China. Methods: 5581 HBsAg carriers were identified by population screening and randomly assigned to a screening group (group A, 3712 men), and controls (group B, 1869 men). Screening was planned to be six monthly alpha-fetoprotein (AFP) assays, with follow-up of subjects having an abnormal (≥20 μg/l) test. All subjects were followed up for liver cancer and/or death until 31 December 1995. Results: The overall sensitivity and specificity of the programme was 55.3% and 86.5%, respectively; in subjects who complied with all scheduled screening tests, the values were 80.0% and 80.9%. Three hundred and seventy-four primary liver cancer (PLC) cases were diagnosed. The percentage of cases in stage I was significantly higher in group A (29.6%) than in group B (6.0%). The one-, three-, and five-year relative survival rates were 23.7%, 7.0%, and 4.0% in group A, and 9.7%, 4.0%, and 4.1% in group B respectively, with no difference in five-year survival between the groups. The mortality rate in the screened group (1138 per 100,000 person-years) was not significantly different from that in the controls (1114 per 100,000). A Poisson regression model showed that the probability of death (rate ratio) in the screening group was 0.83 (95% CI 0.68-1.03) relative to the control group. Conclusions: Screening with AFP resulted in earlier diagnosis of liver cancer, but the gain in lead time did not result in any overall reduction in mortality, because therapy for the patients found by screening was ineffective. Further studies using improved methods of screening, diagnosis and treatment are indicated.
Book Reviews
Authors: Lev Benjamin 
Published: January 2004

The range of books reviewed is wide, covering theory and applications in operations research, statistics, management science, econometrics, mathematics, computers, and information systems (no software is reviewed). In addition, we include books in other fields that emphasize technical applications. Publishers who wish to have their books reviewed should send them to Professor Benjamin Lev. We list the books received; not all books received can be reviewed because space is limited. Those who would like to review books are urged to send me their names, addresses, and specific areas of expertise. We commission all reviews and do not accept unsolicited book reviews. Readers are encouraged to suggest books that might be reviewed or to ask publishers to send me copies of such books. The authors or editors of the books reviewed in this issue are Louis Anthony Cox, Jr., George S. Fishman, Paolo Toth, and Daniele Vigo.
Does the Community Dental Service Provide Primary Dental Care for Dentally Disadvantaged Children?
Authors: Dugmore Christopher R , Nunn June H 
Published: January 2004

Objective To compare the caries prevalence of Community Dental Service (CDS) patients in Leicestershire with the same age groups in the population, and to assess the effectiveness of the CDS in reaching dentally disadvantaged children. Method The caries prevalence of five- and 12-year-old children attending CDS clinics in Leicestershire was recorded in parallel with population data obtained from the British Association of Community Dentistry (BASCD) survey of these age groups in the county. BASCD criteria and conventions were used in both studies. Participants A total of 354 five-year-old and 383 12-year-old CDS clinic patients, and the respective BASCD population samples of 1815 for five-year-olds and 1753 for 12-year-olds. Results In both age groups CDS clinic patients had a significantly (P<0.01) higher caries experience. The provision of treatment for five-year-old CDS clinic patients was greater than that for the five-year-old BASCD population sample. This was also the case for the 12-year-old CDS clinic patients, who, in addition, had twice as many fissure sealants per patient than those in the BASCD sample. The mean DMFT of 12-year-old clinic attenders and the proportion of these children with caries experience were found to be higher than those for children with the poorest scores on the Townsend Deprivation Index. Conclusion The CDS appeared to be effective in reaching, and providing treatment for, dentally disadvantaged children in Leicestershire, and as such in providing a complementary service to the GDS.
Angioedema of the Lips and Tongue Induced by Angiotensin-Converting Enzyme Inhibitor. A Report of Two Cases
Authors: Stevenson Helen A , Steele John C , Field E Anne , Darroch Campbell J 
Published: January 2004

The following case reports describe the clinical presentation, diagnosis and management of two patients who attended Liverpool University Dental Hospital with rapidly increasing swelling of the lips and tongue. Both patients were suffering from angioedema and were taking an angiotensin-converting enzyme (ACE) inhibitor (ACEI). A provisional diagnosis of ACEI-induced angioedema was made. An intramuscular injection of chlorpheniramine maleate was given to both patients and they were immediately transferred to the local accident and emergency department. These cases illustrate the potential role of the general dental practitioner in the early recognition and management of this potentially life-threatening condition.
Do Referrals from Primary Dental Care for Treatment Using General Anaesthesia Comply with General Dental Council Guidelines?
Authors: Thomas David , Royle Ian , John Jeyanthi H , Bainton Peter 
Published: January 2004

Objectives To investigate the quality of information in referrals for patients aged under 16 years referred for dental extraction under general anaesthesia (GA), to ascertain the knowledge and expectations of the parents of these patients, and to determine whether the number of teeth extracted in secondary care coincides with that of the referring dentist. Design Retrospective study of referrals of all patients aged under 16 years referred to community dental clinics in Berkshire, Buckinghamshire, Northamptonshire and Oxfordshire over a 26-day period. Results The majority (62.2%) of the 251 referrals examined were for extractions under GA. Of these, 125 were by letter and 117 using a pro forma. Significantly more pro formas (33) than letters (8) contained a full medical history (P<0.001). A treatment plan was included in significantly more pro formas (76) than letters (49) (P<0.01). Few referrals contained a note about the discussion of alternatives to a GA procedure and only 37% (58/156) of parents reported that the referring general dental practitioner had discussed alternative treatments with them. A total of 551 primary teeth were indicated for removal but 846 teeth were eventually removed. Conclusions Our findings indicate a need for parents of patients referred for GA procedures to be better informed about alternatives. Improvement in the quality of referrals, perhaps with the aid of standard pro formas, would also facilitate more effective management of referred patients.
Geological and Mineralogical Characterization of Zeolites in Lacustrine Tuffs, Ngakuru, Taupo Volcanic Zone, New Zealand
Authors: Brathwaite R. L. 
Published: January 2004

AbstractMordenite and clinoptilolite have replaced glass shards and pumice in vitric tuffs that are the products of ash fall-out into lake basins of late Quaternary age in the Taupo Volcanic Zone. The vitric tuffs are intercalated with siltstone and diatomite and overlie pumice-rich, rhyolitic ignimbrite. A Zr/TiO2-Nb/Y immobile element ratio plot indicates that the vitric tuffs, like the ignimbrite, are of rhyolitic composition. X-ray diffraction and scanning electron microscopy studies indicate that the mordenite and clinoptilolite are accompanied by authigenic K-feldspar and Opal-CT. The zeolites and other authigenic minerals are very fine grained (<10 µm), with open meshes of acicular mordenite crystals that result in low densities (0.7–1.0 g cm−3) in mordenite-rich tuffs. From Pearce element ratio analysis of whole-rock chemical analyses, only Na and K appear to have been mobilized during alteration. The zeolite deposits are associated with sinter, hydrothermal eruption breccias and silicified fault breccias that represent surface or near-surface manifestations of geothermal activity. Plant material extracted from a sinter overlying one of the deposits has a 14C age of 8498±60 BP, which is interpreted to be the age of zeolite deposition for this deposit. Mordenite and clinoptilolite occur in the lower-T (60–110°C) parts of some active or recently active geothermal systems elsewhere in the Taupo Volcanic Zone. The main fluid in these systems is weakly saline (alkali-chloride) water heated by geothermal activity. The Ngakuru zeolite deposits are interpreted as the products of the reaction of vitric tuffs with this type of water in the near-surface part of recently active geothermal systems.
The Mineralogy and Distribution of Zeolitic Tuffs in the Maramures Basin, Romania
Authors: Cochemé Jean-jacques , Leggo Peter J. , Damian Gheorghe , Fulop Alexandrina , Ledésert Béatrice , Grauby Olivier 
Published: January 2004

AbstractThe Maramures Basin, in the Carpathian mountain belt of northern Romania on the border with the Ukraine, belongs to the eastern part of the Pannonian Basin. In the study area, extensional tectonic movements during the Miocene were coeval with silicic and intermediate volcanism in the inner part of the Eastern Carpathians. Throughout this region, explosive events have resulted in the deposition of pyroclastic flows and ash-fall deposits interbedded with marine sediments.Several tuff units of Badenian (15–13.6 Ma) age occurring throughout the area are extensively zeolitized. These rocks occur as massive homogeneous beds, white to pale greenish-blue, and are commonly extensively jointed. In the Bârsana-Calinesti area and along the Morii Valley, two conspicuous tuff units that can be traced over many km are separated by a calcareous sandstone bed. Most tuffs have a vitroclastic texture in which former glass shards are pseudomorphed by clay minerals and clinoptilolite. Opal-CT commonly occurs as clumps of radiating rods that produce a spherical morphology. Also, rare celadonite is found in the lower greenish tuffs. Pyrogenic crystal fragments are quartz, plagioclase and biotite. Folded muscovite plates and fragments of basement rocks are dominant among the lithic clasts. Above the Bârsana Formation, a second series of white zeolitized tuff, the Ocna Sugatag Formation, is represented by at least two different units overlying an evaporite salt deposit. A large outcrop of a massive white tuff at this locality contains abundant fine-grained clinoptilolite and cation-exchange capacity values of >160 meq/100 g. Clinoptilolite-Ca is also present in the Sighetu tuff unit in the northern part of the Maramures Basin where a distinctive horizon contains plant remains preserved in spherical concretions. Plant material and algal limestones in the same succession strongly suggest that the marine depositional environment was close inshore, and shallow-rather than deep-water conditions are inferred. A mineralogically similar, unaltered, volcanic tuff found in the Coas area suggests that the precursor glass was rhyolitic (72–74% SiO2) with a high-K calc-alkaline affinity. We conclude that pervasive zeolitization is due to the interaction between seawater and vitroclasts at an early stage after deposition.
Remediation of Cd- and Pb-Polluted Soil by Treatment with Organozeolite Conditioner
Authors: Coppola Elio , Battaglia Giampiero , Bucci Maria , Ceglie Donato , Colella Abner , Langella Alessio , Buondonno Andrea , Colella Carmine 
Published: January 2004

AbstractThe present work is part of a study focused on the use of organo-zeolite conditioner to remediate soil polluted by toxic elements. The Neapolitan yellow tuff (NYT) was utilized as a component of an organo-mineral sorbent/exchanger soil conditioner with pellet manure (NYT/PM) to reduce the mobility of Cd and Pb and recover plant performance in heavily polluted soils from illegal dumps near Santa Maria La Fossa (Lower Volturno river basin, Campania Region, southern Italy). Pot experiments were performed by adding the NYT/PM mixture (1:1, w/w) to polluted soil at the rates of 0%, 25%, 50% or 75% (w/w). Wheat (Triticum aestivum) was used as the test plant. The addition of organo-zeolite NYT/PM mixture significantly reduced the DTPA (diethylene-triamine-pentaaceti c acid)-extractable Cd and Pb from 1.01 and 97.5 mg kg−1 in the polluted soil, to 0.14 and 11.6 mg kg−1, respectively, in the soil amended with 75% NYT/PM. The best plant response was observed in amended soil systems treated with 25% NYT/PM, whereas larger additions induced plant toxicities due to increased soil salinity.
Effects of the Nature of the Exchangeable Cation and Clay Concentration on the Rheological Properties of Smectite Suspensions
Authors: Malfoy C. , Pantet A. , Monnet P. , Righi D. 
Published: January 2004

AbstractThe rheological characteristics of purified bentonite suspensions as a function of exchangeable cation (Ca2+,NH4+,Li+)$({\rm{C}}{{\rm{a}}^{2 + }},{\rm{NH}}_4^ + ,\;{\rm{L}}{{\rm{i}}^ + })$ are studied at three different clay concentrations (40 gL−1, 60 gL−1, 80 gL−1). A Herschel-Bulkley model is used to determine rheological parameters such as yield value, consistency and fluidification index. The flow curves are typical for shear thinning fluids but differ on two points; presence of yield stress and/or thixotropy. The Li suspensions are not yield stress fluid, and the thixotropy is weakly expressed only for the 80 gL−1 suspension. On the contrary, Ca-clay suspension flow curves always present yield stress and a large thixotropic area. The NH4-clay suspensions exhibit an intermediate behavior as there is no thixotropy, but a yield stress appears for the most concentrated suspension. These differences in macroscopic mechanical properties are discussed with reference to the suggested microscopic clay organization in suspension.
Alteration of Volcanic Rocks and Genesis of Kaolin Deposits in the Şile Region, Northern Istanbul, Turkey. I: Clay mineralogy
Authors: Ece O. Isik , Nakagawa Zenbe-E , Schroeder Paul A. 
Published: January 2004

AbstractThe Şile Region contains discontinuous, cyclic, thin coal beds and industrial clay deposits that were accumulated in lacustrine basins which received extensive volcanoclastic sediments due to transport of highly weathered calc-alkaline volcanic rocks. The Sülüklü area has the largest kaolin deposit in this region. Cyclic kaolinization depended on the degree of leaching of Si and alkalis in cyclic swamp environments and, therefore, kaolinite contents vary in each discontinuous lens-shaped clay bed and underclay within the basin. The kaolins comprise disordered kaolinite, illite, smectite, gibbsite, quartz, pyrite, anatase, K-feldspar and goethite. Depth-related changes in the distribution of clay minerals, associated with coal beds, are indicative of organic acid-mineral reactions. Kaolinite crystallization initiated at the edges of sericitic mica sheets in the form of composite kaolinite stacks. The small size (<1 µm), morphology and poor crystallinity of kaolinite crystals suggest that kaolinization post dated transportation. Primary or secondary origins of particles can be determined from the stacking sequences of kaolinite particles using high-resolution transmission electron microscopy images. Kaolinite stacks always contain a small amount of illite, but smectite is only present in the middle and upper levels. Gibbsite is a main constituent of refractory bauxitic clays locally found as discontinuous lenses and exploited from the lower level of the basin.Genesis of kaolin deposits took place in two stages: first, there was in situ weathering of the oldest andesitic agglomerates, tuffs and ashes at the base of the lacustrine basin coupled with discharge of shallow thermal waters which were initiated by local hydrothermal alteration; second, surface weathering enhanced transportation of altered rocks from the surrounding hills into the lacustrine basin. Kaolinization took place in cyclic swamp environments, as indicated by the presence of cyclic thin- to thick-bedded coals that provided necessary humic and fulvic acids for the post-depositional alteration of altered volcanic rocks to kaolin in dysaerobic, relatively low-pH conditions in saturated groundwater zones.
Effect of Sonication on Particle-Size Distribution in Natural Muscovite and Biotite
Authors: Pérez-Maqueda Luis A. , Franco Francisco , Avilés Miguel A. , Poyato Juan , Pérez-Rodríguez José L. 
Published: January 2004

AbstractThe effects of ultrasound treatment on the mean particle size, crystal structure, crystallite dimensions and specific surface area of natural muscovite and biotite samples have been investigated. Sonication of macroscopic flakes of muscovite and biotite produced a drastic particle-size reduction. The conditions for the preparation of micron and submicron-sized muscovite and biotite particles of narrow particle-size distribution by sonochemistry are described. The effect of sonication on particle-size reduction is more significant for muscovite than for biotite. Thus, for long sonication times (100 h), submicron and micron particles are predominant in muscovite and biotite, respectively. The resulting materials are crystalline, as assayed by X-ray diffraction, only broadening of the diffraction lines due to size-reduction was observed. Nuclear magnetic resonance studies revealed that the coordination of Al and Si was not modified by the treatment. Chemical analysis showed that the composition of the sample was not affected by the sonication except for a small contamination by Ti from the tip cup of the sonication instrument.