483 research outputs found

    Recent epidemiologic trends in periodontitis in the USA

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    The most important development in the epidemiology of periodontitis in the USA during the last decade is the result of improvements in survey methodologies and statistical modeling of periodontitis in adults. Most of these advancements have occurred as the direct outcome of work by the joint initiative known as the Periodontal Disease Surveillance Project by the Centers for Disease Control and Prevention and the American Academy of Periodontology that was established in 2006. This report summarizes some of the key findings of this important initiative and its impact on our knowledge of the epidemiology of periodontitis in US adults. This initiative first suggested new periodontitis case definitions for surveillance in 2007 and revised them slightly in 2012. This classification is now regarded as the global standard for periodontitis surveillance and is used worldwide. First, application of such a standard in reporting finally enables results from different researchers in different countries to be meaningfully compared. Second, this initiative tackled the concern that prior national surveys, which used partial‐mouth periodontal examination protocols, grossly underestimated the prevalence of periodontitis of potentially more than 50%. Consequently, because previous national surveys significantly underestimated the true prevalence of periodontitis, it is not possible to extrapolate any trend in periodontitis prevalence in the USA over time. Any difference calculated may not represent any actual change in periodontitis prevalence, but rather is a consequence of using different periodontal examination protocols. Finally, the initiative addressed the gap in the need for state and local data on periodontitis prevalence. Through the direct efforts of the Centers for Disease Control and Prevention and the American Academy of Periodontology initiative, full‐mouth periodontal probing at six sites around all nonthird molar teeth was included in the 6 years of National Health and Nutrition Examination Surveys from 2009‐2014, yielding complete data for 10 683 dentate community‐dwelling US adults aged 30 to 79 years. Applying the 2012 periodontitis case definitions to the 2009‐2014 National Health and Nutrition Examination Surveys data, the periodontitis prevalence turned out to be much greater than previously estimated, namely affecting 42.2% of the population with 7.8% of people experiencing severe periodontitis. It was also discovered that only the moderate type of periodontitis is driving the increase in periodontitis prevalence with age, not the mild or the severe types whose prevalence do not increase consistently with age, but remain ~ 10%‐15% in all age groups of 40 years and older. The greatest risk for having periodontitis of any type was seen in older people, in males, in minority race/ethnic groups, in poorer and less educated groups, and especially in cigarette smokers. The Centers for Disease Control and Prevention and the American Academy of Periodontology initiative reported, for the first time, the periodontitis prevalence estimated at both local and state levels, in addition to the national level. Also, this initiative developed and validated in field studies a set of eight items for self‐reported periodontitis for use in direct survey estimates of periodontitis prevalence in existing state‐based surveys. These items were also included in the 2009‐2014 National Health and Nutrition Examination Surveys for validation against clinically determined cases of periodontitis. Another novel result of this initiative is that, for the first time, the geographic distribution of practicing periodontists in relation to the geographic distribution of people with severe periodontitis is illustrated. In summary, the precise periodontitis prevalence and distribution among subgroups in the dentate US noninstitutionalized population aged 30‐79 years is better understood because of application of valid periodontitis case definitions to full‐mouth periodontal examination, in combination with reliable information on demographic and health‐related measures. We now can monitor the trend of periodontitis prevalence over time as well as guide public health preventive and intervention initiatives for the betterment of the health of the adult US population.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153044/1/prd12323.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153044/2/prd12323_am.pd

    Risk Indicators for Periodontitis in US Adults: NHANES 2009 to 2012

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142205/1/jper1174.pd

    Enhanced light-matter interaction in an atomically thin semiconductor coupled with dielectric nano-antennas

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    Unique structural and optical properties of atomically thin two-dimensional semiconducting transition metal dichalcogenides enable in principle their efficient coupling to photonic cavities having the optical mode volume close to or below the diffraction limit. Recently, it has become possible to make all-dielectric nano-cavities with reduced mode volumes and negligible non-radiative losses. Here, we realise low-loss high-refractive-index dielectric gallium phosphide (GaP) nano-antennas with small mode volumes coupled to atomic mono- and bilayers of WSe2. We observe a photoluminescence enhancement exceeding 10(4) compared with WSe2 placed on planar GaP, and trace its origin to a combination of enhancement of the spontaneous emission rate, favourable modification of the photoluminescence directionality and enhanced optical excitation efficiency. A further effect of the coupling is observed in the photoluminescence polarisation dependence and in the Raman scattering signal enhancement exceeding 10(3). Our findings reveal dielectric nano-antennas as a promising platform for engineering light-matter coupling in two-dimensional semiconductors

    Human-to-Human Interaction: the Killer Application of Ubiquitous Computing

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    Twenty-five years past the Weiser\u2019s vision of Ubiquitous Computing, and there is not a clear understanding of what is or is not a pervasive system. Due to the loose boundaries of such paradigm, almost any kind of remotely ac-cessible networked system is classified as a pervasive system. We think that that is mainly due to the lack of killer applications that could make this vi-sion clearer. Actually, we think that the most promising killer application is already here, but we are so used to it that we do not see it, as a perfect fitting of the Weiser\u2019s vision: the Human-to-Human Interaction mediated by com-puters

    Adjustable Intragastric Balloons: A 12-Month Pilot Trial in Endoscopic Weight Loss Management

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    Intragastric balloons are associated with (1) early period intolerance, (2) diminished effect within 3–4 months, and (3) bowel obstruction risk mandating removal at 6 months. The introduction of an adjustable balloon could improve comfort and offer greater efficacy. A migration prevention function, safely enabling prolonged implantation, could improve efficacy and weight maintenance post-extraction. The first implantations of an adjustable balloon with an attached migration prevention anchor are reported. The primary endpoint was the absence of bowel perforation, obstruction, or hemorrhage. Eighteen patients with mean BMI of 37.3 were implanted with the Spatz Adjustable Balloon system (ABS) for 12 months. Balloon volumes were adjusted for intolerance or weight loss plateau. Mean weight loss at 24 weeks was 15.6 kg with 26.4% EWL (percent of excess weight loss) and 24.4 kg with 48.8% EWL at 52 weeks. Sixteen adjustments were successfully performed. Six downward adjustments alleviated intolerance, yielding additional mean weight loss of 4.6 kg. Ten upward adjustments for weight loss plateau yielded a mean additional weight loss of 7 kg. Seven balloons were removed prematurely. Complications necessitating early removal included valve malfunction (1), gastritis (1), Mallory–Weiss tear (1), NSAID (2× dose/2 weeks) perforating ulcer (1), and balloon deflation (1). Two incidents of catheter shear from the chain: one passed uneventfully and one caused an esophageal laceration without perforation during extraction. The Spatz ABS has been successfully implanted in 18 patients. (1) Upward adjustments yielded additional weight loss. (2) Downward adjustments alleviated intolerance, with continued weight loss. (3) Preliminary 1-year implantation results are encouraging

    Nonlinear interactions of dipolar excitons and polaritons in MoS2 bilayers

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    Nonlinear interactions between excitons strongly coupled to light are key for accessing quantum many-body phenomena in polariton systems. Atomically-thin two-dimensional semiconductors provide an attractive platform for strong light-matter coupling owing to many controllable excitonic degrees of freedom. Among these, the recently emerged exciton hybridization opens access to unexplored excitonic species, with a promise of enhanced interactions. Here, we employ hybridized interlayer excitons (hIX) in bilayer MoS2 to achieve highly nonlinear excitonic and polaritonic effects. Such interlayer excitons possess an out-of-plane electric dipole as well as an unusually large oscillator strength allowing observation of dipolar polaritons(dipolaritons) in bilayers in optical microcavities. Compared to excitons and polaritons in MoS2 monolayers, both hIX and dipolaritons exhibit about 8 times higher nonlinearity, which is further strongly enhanced when hIX and intralayer excitons, sharing the same valence band, are excited simultaneously. This gives rise to a highly nonlinear regime which we describe theoretically by introducing a concept of hole crowding. The presented insight into many-body interactions provides new tools for accessing few-polariton quantum correlations

    Resonant band hybridization in alloyed transition metal dichalcogenide heterobilayers

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    Bandstructure engineering using alloying is widely utilised for achieving optimised performance in modern semiconductor devices. While alloying has been studied in monolayer transition metal dichalcogenides, its application in van der Waals heterostructures built from atomically thin layers is largely unexplored. Here, we fabricate heterobilayers made from monolayers of WSe2_2 (or MoSe2_2) and Mox_xW1−x_{1-x}Se2_2 alloy and observe nontrivial tuning of the resultant bandstructure as a function of concentration xx. We monitor this evolution by measuring the energy of photoluminescence (PL) of the interlayer exciton (IX) composed of an electron and hole residing in different monolayers. In Mox_xW1−x_{1-x}Se2_2/WSe2_2, we observe a strong IX energy shift of ≈\approx100 meV for xx varied from 1 to 0.6. However, for x<0.6x<0.6 this shift saturates and the IX PL energy asymptotically approaches that of the indirect bandgap in bilayer WSe2_2. We theoretically interpret this observation as the strong variation of the conduction band K valley for x>0.6x>0.6, with IX PL arising from the K-K transition, while for x<0.6x<0.6, the bandstructure hybridization becomes prevalent leading to the dominating momentum-indirect K-Q transition. This bandstructure hybridization is accompanied with strong modification of IX PL dynamics and nonlinear exciton properties. Our work provides foundation for bandstructure engineering in van der Waals heterostructures highlighting the importance of hybridization effects and opening a way to devices with accurately tailored electronic properties.Comment: Supporting Information can be found downloading and extracting the gzipped tar source file listed under "Other formats
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