397 research outputs found
Epidemiologische Verlaufsbeobachtung eines Neugeborenenscreening der Hüfte durch Ultraschall
Epidemiologische Verlaufsbeobachtung eines Neugeborenenscreening der Hüfte durch Ultraschall
In vitro Evaluation der lateralen Guttapercha-Kondensationstechnik mit Fingerspreadern verschiedener Spitzengeometrie.
Ziel: Ziel der Studie war es, den Einfluss von Spreaderform und Aufbereitungstaper bei der lateralen Kondensation auf die Dichtigkeit der Wurzelfüllungen zu untersuchen.
Für diese Studie wurde ein handelsüblicher Spreader so modifiziert, dass seine Arbeitsspitze durch Abflachung Pluggerfunktionalität erhält.
Material&Methode: Insgesamt n=75 frisch extrahierte menschliche Zähne mit geraden Wurzeln wurden so vorbereitet, dass 75 gerade Zahnwurzeln. Diese Zahnwurzeln wurden randomisiert so auf 5 Gruppen aufgeteilt, mit rotierenden Ni/Ti Instrumenten vom Typ Profile 02/50 und 04/50 aufbereitet und unter Verwendung der lateraler Kondensation mit den konventionellen Spreadern pointed sowie modifizierten Spreadern "flat tip gefüllt. Eine negative Kontrollgruppe wurde unter Anwendung der Zentralstifttechnik ohne Sealer abgefüllt. Die Wurzeln wurden bis auf 1 mm oberhalb des Apex mit Nagellack überzogen und anschließend verblindet. Nach Lagerung in 2%-Methylenblau für 4 Tage wurden die Proben in Kaltpolymerisat eingebettet und es wurden sechs serielle Querschnitte im Abstand von 0,8 mm ab dem Apex angefertigt. Die Querschnitte wurden digitalisiert. Bewertet wurden die Penetrationstiefe in mm ab dem Apex und der Penetrationsgrad.
Ergebnisse: Alle Proben zeigten eine ausgeprägte Penetration. Lediglich der Parameter Penetrationsgrad konnte für eine Differenzierung zwischen den Prüfgruppen verwendet werden. Es zeigte sich ein signifikanter Unterschied zwischen der Kontrollgruppe und allen Prüfgruppen. Innerhalb der Prüfgruppen, welche als normalverteilt und varianzhomogen befunden wurden, wurde eine zweifaktorielle Varianzanalyse für die Faktoren "Spreader" und "Taper" durchgeführt. Es ergab sich für den Faktor "Spreader" ein signifikanter Unterschied (p=0,030) ebenso wie für den Faktor "Taper" (p=0,006). Wurzelfüllungen welche mit dem modifizierten Spreader angefertigt wurden zeigen demnach eine statistisch signifikant schlechtere Dichtigkeit (gemessen mittels Penetrationsgrad) als solche die mit konventionellem Spreader kondensiert wurden. Eine Aufbereitung auf einen Taper von 0,04 führt zu einer statistisch signifikant besseren Dichtigkeit (gemessen mittels Penetrationsgrad) als eine Aufbereitung auf einen ISO-normkonformen Taper von 0,02.
Schlussfolgerung: Es konnte gezeigt werden, dass mit dem gewählten Spreaderdesign kein zusätzlicher Nutzen verbunden ist, ja sogar die Dichtigkeit der resultierenden Wurzelfüllungen abnahm. Es ist also nicht angezeigt, Spreader in der beschriebenen Form klinisch zu verwenden.
Weiterhin konnte gezeigt werden, dass die Verwendung eines größeren Aufbereitungstapers auch bei lateraler Kondensation zu dichteren Füllungen führt. Klinisch sollte daher ein entsprechend großer Aufbereitungskonus angestrebt werden
Extensive Copy-Number Variation of Young Genes across Stickleback Populations
MM received funding from the Max Planck innovation funds for this project. PGDF was supported by a Marie Curie European Reintegration Grant (proposal nr 270891). CE was supported by German Science Foundation grants (DFG, EI 841/4-1 and EI 841/6-1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Understanding Variation in Sets of N-of-1 Trials.
A recent paper in this journal by Chen and Chen has used computer simulations to examine a number of approaches to analysing sets of n-of-1 trials. We have examined such designs using a more theoretical approach based on considering the purpose of analysis and the structure as regards randomisation that the design uses. We show that different purposes require different analyses and that these in turn may produce quite different results. Our approach to incorporating the randomisation employed when the purpose is to test a null hypothesis of strict equality of the treatment makes use of Nelder's theory of general balance. However, where the purpose is to make inferences about the effects for individual patients, we show that a mixed model is needed. There are strong parallels to the difference between fixed and random effects meta-analyses and these are discussed
The Global Atlas of Helminth Infection: Mapping the Way Forward in Neglected Tropical Disease Control
A Measurement of Rb using a Double Tagging Method
The fraction of Z to bbbar events in hadronic Z decays has been measured by
the OPAL experiment using the data collected at LEP between 1992 and 1995. The
Z to bbbar decays were tagged using displaced secondary vertices, and high
momentum electrons and muons. Systematic uncertainties were reduced by
measuring the b-tagging efficiency using a double tagging technique. Efficiency
correlations between opposite hemispheres of an event are small, and are well
understood through comparisons between real and simulated data samples. A value
of Rb = 0.2178 +- 0.0011 +- 0.0013 was obtained, where the first error is
statistical and the second systematic. The uncertainty on Rc, the fraction of Z
to ccbar events in hadronic Z decays, is not included in the errors. The
dependence on Rc is Delta(Rb)/Rb = -0.056*Delta(Rc)/Rc where Delta(Rc) is the
deviation of Rc from the value 0.172 predicted by the Standard Model. The
result for Rb agrees with the value of 0.2155 +- 0.0003 predicted by the
Standard Model.Comment: 42 pages, LaTeX, 14 eps figures included, submitted to European
Physical Journal
Measurement of the B+ and B-0 lifetimes and search for CP(T) violation using reconstructed secondary vertices
The lifetimes of the B+ and B-0 mesons, and their ratio, have been measured in the OPAL experiment using 2.4 million hadronic Z(0) decays recorded at LEP. Z(0) --> b (b) over bar decays were tagged using displaced secondary vertices and high momentum electrons and muons. The lifetimes were then measured using well-reconstructed charged and neutral secondary vertices selected in this tagged data sample. The results aretau(B+) = 1.643 +/- 0.037 +/- 0.025 pstau(Bo) = 1.523 +/- 0.057 +/- 0.053 pstau(B+)/tau(Bo) = 1.079 +/- 0.064 +/- 0.041,where in each case the first error is statistical and the second systematic.A larger data sample of 3.1 million hadronic Z(o) decays has been used to search for CP and CPT violating effects by comparison of inclusive b and (b) over bar hadron decays, No evidence fur such effects is seen. The CP violation parameter Re(epsilon(B)) is measured to be Re(epsilon(B)) = 0.001 +/- 0.014 +/- 0.003and the fractional difference between b and (b) over bar hadron lifetimes is measured to(Delta tau/tau)(b) = tau(b hadron) - tau((b) over bar hadron)/tau(average) = -0.001 +/- 0.012 +/- 0.008
Adaptive plasticity of killifish (Fundulus heteroclitus) embryos: dehydration-stimulated development and differential aquaporin-3 expression
13 pages, 7 figures, 3 tablesEmbryos of the marine killifish Fundulus heteroclitus are adapted to survive aerially. However, it is unknown if they are able to control development under dehydration conditions. Here, we show that air-exposed blastula embryos under saturated relative humidity were able to stimulate development, and hence the time of hatching was advanced with respect to embryos continuously immersed in seawater. Embryos exposed to air at later developmental stages did not hatch until water was added, while development was not arrested. Air-exposed embryos avoided dehydration probably because of their thickened egg envelope, although it suffered significant evaporative water loss. The potential role of aquaporins as part of the embryo response to dehydration was investigated by cloning the aquaporin-0 (FhAqp0), -1a (FhAqp1a), and -3 (FhAqp3) cDNAs. Functional expression in Xenopus laevis oocytes showed that FhaAqp1a was a water-selective channel, whereas FhAqp3 was permeable to water, glycerol, and urea. Expression of fhaqp0 and fhaqp1a was prominent during organogenesis, and their mRNA levels were similar between water- and air-incubated embryos. However, fhaqp3 transcripts were highly and transiently accumulated during gastrulation, and the protein product was localized in the basolateral membrane of the enveloping epithelial cell layer and in the membrane of ingressing and migrating blastomers. Interestingly, both fhaqp3 transcripts and FhAqp3 polypeptides were downregulated in air-exposed embryos. These data demonstrate that killifish embryos respond adaptively to environmental desiccation by accelerating development and that embryos are able to transduce dehydration conditions into molecular responses. The reduced synthesis of FhAqp3 may be one of these mechanisms to regulate water and/or solute transport in the embryo.This study was supported by the European Commission New and Emerging
Science and Technologies (NEST) program (contract no. 012674-2 Sleeping
Beauty) and by a grant from the Spanish Ministry of Education and Science
(MEC; AGL2004-00316/ACU) to J. Cerda`. Participation of C. Zapater and F.
Chauvigne´ was financed by a predoctoral fellowship from MEC (Spain) and by
the European Commission [Marie Curie Research Training Network Aqua
(glycero)porins, MRTN-CT-2006-035995], respectively.Peer reviewe
An assessment of orofacial clefts in Tanzania
<p>Abstract</p> <p>Background</p> <p>Clefts of the lip (CL), the palate (CP), or both (CLP) are the most common orofacial congenital malformations found among live births, accounting for 65% of all head and neck anomalies. The frequency and pattern of orofacial clefts in different parts of the world and among different human groups varies widely. Generally, populations of Asian or Native American origin have the highest prevalence, while Caucasian populations show intermediate prevalence and African populations the lowest. To date, little is known regarding the epidemiology and pattern of orofacial clefts in Tanzania.</p> <p>Methods</p> <p>A retrospective descriptive study was conducted at Bugando Medical Centre to identify all children with orofacial clefts that attended or were treated during a period of five years. Cleft lip and/or palate records were obtained from patient files in the Hospital's Departments of Surgery, Paediatrics and medical records. Age at presentation, sex, region of origin, type and laterality of the cleft were recorded. In addition, presence of associated congenital anomalies or syndromes was recorded.</p> <p>Results</p> <p>A total of 240 orofacial cleft cases were seen during this period. Isolated cleft lip was the most common cleft type followed closely by cleft lip and palate (CLP). This is a departure from the pattern of clefting reported for Caucasian and Asian populations, where CLP or isolated cleft palate is the most common type. The distribution of clefts by side showed a statistically significant preponderance of the left side (43.7%) (χ<sup>2 </sup>= 92.4, p < 0.001), followed by the right (28.8%) and bilateral sides (18.3%). Patients with isolated cleft palate presented at very early age (mean age 1.00 years, SE 0.56). Associated congenital anomalies were observed in 2.8% of all patients with orofacial clefts, and included neural tube defects, Talipes and persistent ductus arteriosus.</p> <p>Conclusions</p> <p>Unilateral orofacial clefts were significantly more common than bilateral clefts; with the left side being the most common affected side. Most of the other findings did not show marked differences with orofacial cleft distributions in other African populations.</p
Lower age at menarche affects survival in older Australian women: results from the Australian Longitudinal Study of Ageing
Extent: 10p.Background: While menarche indicates the beginning of a woman's reproductive life, relatively little is known about the association between age at menarche and subsequent morbidity and mortality. We aimed to examine the effect of lower age at menarche on all-cause mortality in older Australian women over 15 years of follow-up. Methods: Data were drawn from the Australian Longitudinal Study of Ageing (n = 1,031 women aged 65-103 years). We estimated the hazard ratio (HR) associated with lower age at menarche using Cox proportional hazards models, and adjusted for a broad range of reproductive, demographic, health and lifestyle covariates. Results: During the follow-up period, 673 women (65%) died (average 7.3 years (SD 4.1) of follow-up for decedents). Women with menses onset < 12 years of age (10.7%; n = 106) had an increased hazard of death over the follow-up period (adjusted HR 1.28; 95%CI 0.99-1.65) compared with women who began menstruating aged ≥ 12 years (89.3%; n = 883). However, when age at menarche was considered as a continuous variable, the adjusted HRs associated with the linear and quadratic terms for age at menarche were not statistically significant at a 5% level of significance (linear HR 0.76; 95%CI 0.56 - 1.04; quadratic HR 1.01; 95%CI 1.00-1.02). Conclusion: Women with lower age at menarche may have reduced survival into old age. These results lend support to the known associations between earlier menarche and risk of metabolic disease in early adulthood. Strategies to minimise earlier menarche, such as promoting healthy weights and minimising family dysfunction during childhood, may also have positive longer-term effects on survival in later life.Lynne C Giles, Gary FV Glonek, Vivienne M Moore, Michael J Davies and Mary A Luszc
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