273 research outputs found
Fracture resistance of roots filled with three different obturation techniques
Objectives: The aim of this study was to compare in vitro root fracture resistance following root canal filling with AH 26 using lateral condensation, BeeFill, and Thermafil techniques. Study Design: Eighty extracted human mandibular premolars with similar dimensions were selected. In order to standardize the roots, measurements were taken in two separate regions of the teeth?at the cemento-enamel junction and 8 mm apically from the junction?buccolingual as well as mesiodistal for every tooth. Teeth were then randomly divided into five groups (n=16). With the exception of the non-prepared group (Group 1), instrumentation was done in all groups. In group 2, instrumentation but no filling was performed; in group 3, the obturation was done with AH 26 + gutta-percha; in group 4, with AH 26 + BeeFill and in group 5, AH 26 + a Thermafil obturator was used. All the roots were mounted vertically in copper rings and filled with acrylic resin, exposing 8 mm of the coronal part. A universal testing machine was used for the strength test. Results: The results were analyzed using the one-way ANOVA test. The significance between the groups was tested with Temhane?s T2 test. The results indicate that instrumentation of root canals had a significant effect on fracture resistance (p0.05). Conclusions: The results suggest that instrumentation of root canals significantly weakens the tooth structure to fracture and the root canal obturation techniques that are used are not able to form reinforcement
Prognosis of a case with paresthesia associated with prolonged touching of an endodontic paste to the inferior alveolar nerve
Paresthesia is described as an abnormal sensation, such as burning, pricking, tickling, tingling, formication or numbness.
Several conditions can cause paresthesia. This article presents a case of paresthesia caused by the extrusion
of endodontic paste (Endomethasone®) into the mandibular canal. The clinical manifestations comprised the numbness
on the right side of the mandible and right lower lip, appearing after endodontic treatment. After a mandibular
block and infiltration anesthesia a mucoperiostal flap was raised and the extruded Endomethasone® was removed
successfully. A therapy with antibiotic, B vitamin complex and an analgesic were prescribed. The patient reported
an improvement in pain and headache after one week later and in burning after two weeks. After a four months
follow-up, she became symptom free. Also sixteen months later she had any symptoms. Normalization of sensation
shows that the neurotoxic effects of Endomethasone® are reversible after more than one month from the first touch
of Endomethasone® to the inferior alveolar nerv
Scheduling data flow program in xkaapi: A new affinity based Algorithm for Heterogeneous Architectures
Efficient implementations of parallel applications on heterogeneous hybrid
architectures require a careful balance between computations and communications
with accelerator devices. Even if most of the communication time can be
overlapped by computations, it is essential to reduce the total volume of
communicated data. The literature therefore abounds with ad-hoc methods to
reach that balance, but that are architecture and application dependent. We
propose here a generic mechanism to automatically optimize the scheduling
between CPUs and GPUs, and compare two strategies within this mechanism: the
classical Heterogeneous Earliest Finish Time (HEFT) algorithm and our new,
parametrized, Distributed Affinity Dual Approximation algorithm (DADA), which
consists in grouping the tasks by affinity before running a fast dual
approximation. We ran experiments on a heterogeneous parallel machine with six
CPU cores and eight NVIDIA Fermi GPUs. Three standard dense linear algebra
kernels from the PLASMA library have been ported on top of the Xkaapi runtime.
We report their performances. It results that HEFT and DADA perform well for
various experimental conditions, but that DADA performs better for larger
systems and number of GPUs, and, in most cases, generates much lower data
transfers than HEFT to achieve the same performance
Assessment of the prevalence and characteristics of dens invaginatus in a sample of Turkish Anatolian population
Objective: The objective of this study was to assess the prevalence and characteristics of dens invaginatus in anterior teeth and to classify the type of dens invaginatus in a sample of Turkish Anatolian population. Study design: A retrospective study was performed using full-mouth periapical and panoramic radiographs of 1012 patients. Maxillary and mandibular anterior teeth were evaluated for the presence and characteristics of dens invaginatus. Statistical evaluation of the presence of dens invaginatus related to gender was performed by the Pearson chi-squared test. Results: Dens invaginatus was observed in 13 out of 1012 subjects and in only maxillary lateral incisors. There were no periapical lesions in teeth with types I and II, whereas both of the subjects with type III had apical periodontitis at the time of referral. Males and females were almost equally affected by dens invaginatus (P= 0.98). Conclusion: The anomaly was detected in only maxillary lateral incisors with no gender difference and the most commonly observed type of dens invaginatus was type I (81.25%)
Automatic Calibration of Performance Models on Heterogeneous Multicore Architectures
International audienceMulticore architectures featuring specialized accelerators are getting an increasing amount of attention, and this success will probably influence the design of future High Performance Computing hardware. Unfortunately, programmers are actually having a hard time trying to exploit all these heterogeneous computing units efficiently, and most existing efforts simply focus on providing tools to offload some computations on available accelerators. Recently, some runtime systems have been designed that exploit the idea of scheduling -- as opposed to offloading -- parallel tasks over the whole set of heterogeneous computing units. Scheduling tasks over heterogeneous platforms makes it necessary to use accurate prediction models in order to assign each task to its most adequate computing unit. A deep knowledge of the application is usually required to model per-task performance models, based on the algorithmic complexity of the underlying numeric kernel. We present an alternate, auto-tuning performance prediction approach based on performance history tables dynamically built during the application run. This approach does not require that the programmer provides some specific information. We show that, thanks to the use of a carefully chosen hash-function, our approach quickly achieves accurate performance estimations automatically. Our approach even outperforms regular algorithmic performance models with several linear algebra numerical kernels
Solving the Uncapacitated Single Allocation p-Hub Median Problem on GPU
A parallel genetic algorithm (GA) implemented on GPU clusters is proposed to
solve the Uncapacitated Single Allocation p-Hub Median problem. The GA uses
binary and integer encoding and genetic operators adapted to this problem. Our
GA is improved by generated initial solution with hubs located at middle nodes.
The obtained experimental results are compared with the best known solutions on
all benchmarks on instances up to 1000 nodes. Furthermore, we solve our own
randomly generated instances up to 6000 nodes. Our approach outperforms most
well-known heuristics in terms of solution quality and time execution and it
allows hitherto unsolved problems to be solved
Predictive runtime code scheduling for heterogeneous architectures
Heterogeneous architectures are currently widespread. With
the advent of easy-to-program general purpose GPUs, virtually every re-
cent desktop computer is a heterogeneous system. Combining the CPU
and the GPU brings great amounts of processing power. However, such
architectures are often used in a restricted way for domain-speci c appli-
cations like scienti c applications and games, and they tend to be used
by a single application at a time. We envision future heterogeneous com-
puting systems where all their heterogeneous resources are continuously
utilized by di erent applications with versioned critical parts to be able
to better adapt their behavior and improve execution time, power con-
sumption, response time and other constraints at runtime. Under such a
model, adaptive scheduling becomes a critical component.
In this paper, we propose a novel predictive user-level scheduler based on
past performance history for heterogeneous systems. We developed sev-
eral scheduling policies and present the study of their impact on system
performance. We demonstrate that such scheduler allows multiple appli-
cations to fully utilize all available processing resources in CPU/GPU-
like systems and consistently achieve speedups ranging from 30% to 40%
compared to just using the GPU in a single application mode.Postprint (published version
Missing paternal demographics: A novel indicator for identifying high risk population of adverse pregnancy outcomes
BACKGROUND: One of every 6 United Status birth certificates contains no information on fathers. There might be important differences in the pregnancy outcomes between mothers with versus those without partner information. The object of this study was to assess whether and to what extent outcomes in pregnant women who did not have partner information differ from those who had. METHODS: We carried out a population-based retrospective cohort study based on the registry data in the United States for the period of 1995–1997, which was a matched multiple birth file (only twins were included in the current analysis). We divided the study subjects into three groups according to the availability of partner information: available, partly missing, and totally missing. We compared the distribution of maternal characteristics, maternal morbidity, labor and delivery complications, obstetric interventions, preterm birth, fetal growth restriction, low birth weight, congenital anomalies, fetal death, neonatal death, post-neonatal death, and neonatal morbidity among three study groups. RESULTS: There were 304466 twins included in our study. Mothers whose partner's information was partly missing and (especially) totally missing tended to be younger, of black race, unmarried, with less education, smoking cigarette during pregnancy, and with inadequate prenatal care. The rates of preterm birth, fetal growth restriction, low birth weight, Apgar score <7, fetal mortality, neonatal mortality, and post-neonatal mortality were significantly increased in mothers whose partner's information was partly or (especially) totally missing. CONCLUSIONS: Mothers whose partner's information was partly and (especially) totally missing are at higher risk of adverse pregnant outcomes, and clinicians and public health workers should be alerted to this important social factor
QUANTITATIVE VS. CONVENTIONAL PCR FOR DETECTION OF HUMAN ADENOVIRUSES IN WATER AND SEDIMENT SAMPLES
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