Study of the efficiency of profile subjects taught to students of the dental faculty from the first semester of the first year

The purpose of the study is to find out the differences in knowledge and attitude to oral hygiene among the first and second–year students as well as fourth and fifth-year students of USMU Faculty of Dentistry to assess the effectiveness of teaching junior students the profile subjects.Цель исследования – выявление отличий в знаниях и отношении к гигиене полости рта между студентами 1–2 и 4–5 курсов стоматологического факультета УГМУ для оценки эффективности обучения студентов 1–2 курсов профильным предметам

Принципы хирургического лечения рецидивных грыж пищеводного отверстия диафрагмы (обзор литературы)

Recurrent hiatal hernia is the re-displacement of the abdominal organs into the chest after surgical treatment. Indications for repeated surgical interventions for this pathology are resistant to medical correction gastroesophageal reflux or anatomical disorders, bearing the risk of developing life-threatening conditions. The key task of revision interventions is to identify and address the causes of the failure of the primary operation. The main factors of the recurrence of hernias of this localization are the large size of the hiatal opening, the mechanical weakness of the legs of the diaphragm and the shortening of the esophagus. To increase the reliability of the esophageal aperture plasty in the surgical treatment of recurrent hiatal hernias, prosthetic materials are widely used. When the esophagus is shortened, it is possible to increase its length by creating a gastric stalk (gastroplasty) or fixing the stomach to the anterior abdominal wall (gastropexy). The disadvantage of both methods is the occurring functional impairment. An alternative approach is the formation of a fundoplication wrap in the chest with the closure of the esophageal opening only with its own tissues. To eliminate or prevent the development of gastroesophageal reflux, antireflux reconstruction is an essential component of operations for recurrent hiatal hernias. The option of fundoplication is selected in accordance with the contractility of the esophagus. With normokinesia, circular fundoplication was preferred, with impaired motor skills – free reconstructions.Под рецидивными грыжами пищеводного отверстия диафрагмы понимают любые варианты повторного смещения органов брюшной полости в грудную клетку после хирургического лечения. Показаниями к повторным оперативным вмешательствам при данной патологии являются не поддающийся медикаментозной коррекции гастроэзофагеальный рефлюкс или анатомические нарушения, несущие риск развития угрожающих жизни состояний. Ключевая задача ревизионных вмешательств заключается в выявлении и устранении причин неудачного исхода первичной операции. Основными факторами повторного возникновения грыж данной локализации являются большие размеры хиатального отверстия, механическая слабость ножек диафрагмы и укорочение пищевода. Для повышения надежности пластики пищеводного отверстия диафрагмы при хирургическом лечении рецидивных хиатальных грыж широко используются протезирующие материалы. При укорочении пищевода возможно увеличение его длины созданием желудочного стебля (гастропластика), фиксация желудка к передней брюшной стенке (гастропексия). Недостатком обеих методик являются возникающие функциональные нарушения. Альтернативный подход – формирование фундопликационной манжеты в грудной клетке с закрытием пищеводного отверстия только собственными тканями. Для устранения или профилактики развития желудочно-пищеводного заброса обязательным компонентом операций при рецидивных хиатальных грыжах является антирефлюксная реконструкция. Вариант фундопликации выбирается в соответствии с сократительной способностью пищевода. При нормокинезии предпочтительны циркулярные фундопликации, при нарушениях моторики – свободные реконструкции

Comparison of advanced gravitational-wave detectors

We compare two advanced designs for gravitational-wave antennas in terms of their ability to detect two possible gravitational wave sources. Spherical, resonant mass antennas and interferometers incorporating resonant sideband extraction (RSE) were modeled using experimentally measurable parameters. The signal-to-noise ratio of each detector for a binary neutron star system and a rapidly rotating stellar core were calculated. For a range of plausible parameters we found that the advanced LIGO interferometer incorporating RSE gave higher signal-to-noise ratios than a spherical detector resonant at the same frequency for both sources. Spheres were found to be sensitive to these sources at distances beyond our galaxy. Interferometers were sensitive to these sources at far enough distances that several events per year would be expected

Searching for gravitational waves from known pulsars

We present upper limits on the amplitude of gravitational waves from 28 isolated pulsars using data from the second science run of LIGO. The results are also expressed as a constraint on the pulsars' equatorial ellipticities. We discuss a new way of presenting such ellipticity upper limits that takes account of the uncertainties of the pulsar moment of inertia. We also extend our previous method to search for known pulsars in binary systems, of which there are about 80 in the sensitive frequency range of LIGO and GEO 600.Comment: Accepted by CQG for the proceeding of GWDAW9, 7 pages, 2 figure

Setting upper limits on the strength of periodic gravitational waves from PSR J1939+2134 using the first science data from the GEO 600 and LIGO detectors

Data collected by the GEO 600 and LIGO interferometric gravitational wave detectors during their first observational science run were searched for continuous gravitational waves from the pulsar J1939+2134 at twice its rotation frequency. Two independent analysis methods were used and are demonstrated in this paper: a frequency domain method and a time domain method. Both achieve consistent null results, placing new upper limits on the strength of the pulsar's gravitational wave emission. A model emission mechanism is used to interpret the limits as a constraint on the pulsar's equatorial ellipticity

Titin truncating variants affect heart function in disease cohorts and the general population

Titin-truncating variants (TTNtv) commonly cause dilated cardiomyopathy (DCM). TTNtv are also encountered in ~1% of the general population, where they may be silent, perhaps reflecting allelic factors. To better understand TTNtv, we integrated TTN allelic series, cardiac imaging and genomic data in humans and studied rat models with disparate TTNtv. In patients with DCM, TTNtv throughout titin were significantly associated with DCM. Ribosomal profiling in rat showed the translational footprint of premature stop codons in Ttn, TTNtv-position-independent nonsense-mediated degradation of the mutant allele and a signature of perturbed cardiac metabolism. Heart physiology in rats with TTNtv was unremarkable at baseline but became impaired during cardiac stress. In healthy humans, machine-learning-based analysis of high-resolution cardiac imaging showed TTNtv to be associated with eccentric cardiac remodeling. These data show that TTNtv have molecular and physiological effects on the heart across species, with a continuum of expressivity in health and disease

Improving the sensitivity to gravitational-wave sources by modifying the input-output optics of advanced interferometers

We study frequency dependent (FD) input-output schemes for signal-recycling interferometers, the baseline design of Advanced LIGO and the current configuration of GEO 600. Complementary to a recent proposal by Harms et al. to use FD input squeezing and ordinary homodyne detection, we explore a scheme which uses ordinary squeezed vacuum, but FD readout. Both schemes, which are sub-optimal among all possible input-output schemes, provide a global noise suppression by the power squeeze factor, while being realizable by using detuned Fabry-Perot cavities as input/output filters. At high frequencies, the two schemes are shown to be equivalent, while at low frequencies our scheme gives better performance than that of Harms et al., and is nearly fully optimal. We then study the sensitivity improvement achievable by these schemes in Advanced LIGO era (with 30-m filter cavities and current estimates of filter-mirror losses and thermal noise), for neutron star binary inspirals, and for narrowband GW sources such as low-mass X-ray binaries and known radio pulsars. Optical losses are shown to be a major obstacle for the actual implementation of these techniques in Advanced LIGO. On time scales of third-generation interferometers, like EURO/LIGO-III (~2012), with kilometer-scale filter cavities, a signal-recycling interferometer with the FD readout scheme explored in this paper can have performances comparable to existing proposals. [abridged]Comment: Figs. 9 and 12 corrected; Appendix added for narrowband data analysi

Upper limits on the strength of periodic gravitational waves from PSR J1939+2134

The first science run of the LIGO and GEO gravitational wave detectors presented the opportunity to test methods of searching for gravitational waves from known pulsars. Here we present new direct upper limits on the strength of waves from the pulsar PSR J1939+2134 using two independent analysis methods, one in the frequency domain using frequentist statistics and one in the time domain using Bayesian inference. Both methods show that the strain amplitude at Earth from this pulsar is less than a few times $10^{-22}$.Comment: 7 pages, 1 figure, to appear in the Proceedings of the 5th Edoardo Amaldi Conference on Gravitational Waves, Tirrenia, Pisa, Italy, 6-11 July 200

Analysis of LIGO data for gravitational waves from binary neutron stars

We report on a search for gravitational waves from coalescing compact binary systems in the Milky Way and the Magellanic Clouds. The analysis uses data taken by two of the three LIGO interferometers during the first LIGO science run and illustrates a method of setting upper limits on inspiral event rates using interferometer data. The analysis pipeline is described with particular attention to data selection and coincidence between the two interferometers. We establish an observational upper limit of $\mathcal{R}<$1.7 \times 10^{2}$per year per Milky Way Equivalent Galaxy (MWEG), with 90coalescence rate of binary systems in which each component has a mass in the range 1--3$M_\odot$.Comment: 17 pages, 9 figure

First upper limits from LIGO on gravitational wave bursts

We report on a search for gravitational wave bursts using data from the first science run of the LIGO detectors. Our search focuses on bursts with durations ranging from 4 ms to 100 ms, and with significant power in the LIGO sensitivity band of 150 to 3000 Hz. We bound the rate for such detected bursts at less than 1.6 events per day at 90% confidence level. This result is interpreted in terms of the detection efficiency for ad hoc waveforms (Gaussians and sine-Gaussians) as a function of their root-sum-square strain h_{rss}; typical sensitivities lie in the range h_{rss} ~ 10^{-19} - 10^{-17} strain/rtHz, depending on waveform. We discuss improvements in the search method that will be applied to future science data from LIGO and other gravitational wave detectors.Comment: 21 pages, 15 figures, accepted by Phys Rev D. Fixed a few small typos and updated a few reference