Cascaded Parametric Amplification for Highly Efficient Terahertz Generation

A highly efficient, practical approach to high-energy terahertz (THz) generation based on spectrally cascaded optical parametric amplification (THz-COPA) is introduced. The THz wave initially generated by difference frequency generation between a strong narrowband optical pump and optical seed (0.1-10% of pump energy) kick-starts a repeated or cascaded energy down-conversion of pump photons. This helps to greatly surpass the quantum-defect efficiency and results in exponential growth of THz energy over crystal length. In cryogenically cooled periodically poled lithium niobate, energy conversion efficiencies >8% for 100 ps pulses are predicted. The calculations account for cascading effects, absorption, dispersion and laser-induced damage. Due to the coupled nonlinear interaction of multiple triplets of waves, THz-COPA exhibits physics distinct from conventional three-wave mixing parametric amplifiers. This in turn governs optimal phase-matching conditions, evolution of optical spectra as well as limitations of the nonlinear process.Comment: 5 pages, double colum

Towards Process-Driven Mobile Data Collection Applications: Requirements, Challenges, Lessons Learned

In application domains like healthcare, psychology and e-learning, data collection is based on specifically tailored paper & pencil questionnaires. Usually, such a paper-based data collection is accomplished by a massive workload regarding the processing, analysis, and evaluation of the data collected. To relieve domain experts from these manual tasks and to increase the efficiency of the data collection process, we developed a generic approach for realizing process-driven smart mobile device applications based on process management technology. According to this approach, the logic of a questionnaire is described in terms of an explicit process model whose enactment is driven by a generic process engine. Our goal is to demonstrate that such a process-aware design of mobile business applications is useful with respect to mobile data collection. Hence, we developed a generic architecture comprising the main components of mobile data collection applications. Furthermore, we used these components for developing mobile electronic questionnaires for psychological studies. The paper presents the challenges identified in this context and discusses the lessons learned. Overall, process management technology offers promising perspectives for developing mobile business applications at a high level of abstraction

Generic Concept for Integrating Voice Assistance Into Smart Therapeutic Interventions

Therapeutic Interventions (TIs) play an important role in modern medical and psychological treatments, but their integration into the digital world still shows deficits, e.g., in the integration of the auditory interface. Initiatives to integrate this interface into existing Internet- and Mobile-Based Inter- ventions (IMIs) are largely focused on a small group of Voice Assistants (VAs) and their specific capabilities. To mitigate these drawbacks, the presented concept seamlessly integrates arbitrary VAs into the treatment process of TIs. To this end, an architecture - including a discussion of relevant requirements - is presented that, on the one hand, uses VAs as the only point of contact with patients and, on the other hand, provides a comprehensive web- based backend for Healthcare Providers (HCPs). Based on the architecture, a proof-of-concept implementation using Amazon Alexa is presented. Finally, it is discussed that the scenario addressed and the solution presented have great potential, but still need a lot of work and technical consideration

Techniques and Emerging Trends for State of the Art Equipment Maintenance Systems - A Bibliometric Analysis

The increasing interconnection of machines in industrial production on one hand, and the improved capabilities to store, retrieve, and analyze large amounts of data on the other, offer promising perspectives for maintaining production machines. Recently, predictive maintenance has gained increasing attention in the context of equipment maintenance systems. As opposed to other approaches, predictive maintenance relies on machine behavior models, which offer several advantages. In this highly interdisciplinary field, there is a lack of a literature review of relevant research fields and realization techniques. To obtain a comprehensive overview on the state of the art, large data sets of relevant literature need to be considered and, best case, be automatically partitioned into relevant research fields. A proper methodology to obtain such an overview is the bibliometric analysis method. In the presented work, we apply a bibliometric analysis to the field of equipment maintenance systems. To be more precise, we analyzed clusters of identified literature with the goal to obtain deeper insight into the related research fields. Moreover, cluster metrics reveal the importance of a single paper and an investigation of the temporal cluster development indicates the evolution of research topics. In this context, we introduce a new measure to compare results from different time periods in an appropriate way. In turn, among others, this simplifies the analysis of topics, with a vast amount of subtopics. Altogether, the obtained results particularly provide a comprehensive overview of established techniques and emerging trends for equipment maintenance systems

What are the Systemic Factors Associated with the Molar-Incisor Hypomineralization Etiology?

Objective: To evaluate the systemic factors associated with Molar-Incisor Hypomineralization (MIH) etiology. Material and Methods: A total of 731 8-year-old schoolchildren enrolled in the public school system in Curitiba, Brazil, was randomly selected. The MIH diagnosis was performed by calibrated examiners (Kappa >0.80) according to the European Academy of Pediatric Dentistry criteria (2003). The systemic factors were collected through a semi-structured questionnaire and applied to the children’s mothers, addressing the medical history from pregnancy to the first three years of children’s life. Associations were analyzed by Poisson regression analysis with robust variance (p<0.05). Results: The systemic factors in the prenatal and perinatal periods were not associated with MIH (p>0.05). The children who used medications during the first years of life had a significantly higher prevalence of MIH (PRc = 2.18 CI = 95% 1.06–4.48; p=0.033). Conclusion: The use of medications during the first three years of children’s life is associated with a higher prevalence of MIH

Dental and oral manifestations of celiac disease

The objective of this study was to evaluate the dental and oral manifestations in patients with celiac disease. The sample consisted of 40 patients with the disease and 40 without the disease matched by age in southern Brazil. The CD group included patients previously diagnosed by positive anti-endomysial (IgA) examination and confirmed by small intestine biopsy. The presence of dental enamel defects and dental caries was evaluated by a calibrated researcher according to AINE?s and WHO?s criteria, respectively. The history of recurrent aphthous ulcers and dry mouth was obtained through reporting. For the evaluation of the salivary flow, the saliva samples were obtained through the non-stimulated and stimulated saliva collection method. There was a significant association between CD and dental enamel defects (OR=2.38, P=0.045) and dry mouth (OR=9.15, P=0.002). No difference was found for the report of recurrent aphthous ulcers and caries experience between the two groups. Patients with CD had normal pattern of unstimulated and stimulated saliva flow rates (0.67 ± 0.38 ml / min and 1.14 ± 0.47 ml / min, respectively). A higher occurrence of dental enamel defects was observed in patients with classic CD (P=0.054). Of the 1,962 permanent teeth, 59 presented dental enamel defects, 71.8% of which were in patients with CD (P=0.001), predominantly in molars (P=0.009). CD increased the likelihood of dental enamel defects and dry mouth sensation. The oral examination can be an important auxiliary tool for the identification of cases of the disease

Association Between Periodontal Health Knowledge and Oral Hygiene in Brazilian Adolescents

Objective: To evaluate the influence of oral health knowledge in adolescents’ oral hygiene pattern. Material and Methods: Cross-sectional study involving 291 participants aged between 14 and 19 years old enrolled in a public school in Curitiba, Brazil. A self-administered questionnaire containing five affirmations about periodontal diseases and their forms of prevention was arranged on a three-point Likert scale. Correct answers were given a weight=1 and incorrect ones, weight=0. The knowledge score (KS) was determined by the sum. Socioeconomic and demographic data were obtained by a questionnaire sent to those responsible. The oral hygiene pattern was evaluated through the simplified oral hygiene index (OHI-S) by a calibrated researcher (K=0.89). Mann-Whitney U test and univariate and multivariate Poisson regression with robust variance were used for data analysis (α=0.05). Results: There was an inversely proportional association between KS and OHI-S (p=0.018). The multiple model showed that adolescents with a lower KS (PR = 0.93, CI95%: 0.88-0.99), male gender (PR = 1.17, CI95%: 1.01-1.37) and whose caregivers presented a lower level of education (PR=1.30, CI95%: 1.03-1.64) showed a higher index of dental plaque. Conclusion: The level of oral health knowledge, the gender and the caregivers’ level of education influences the adolescents’ oral hygiene pattern

Membranolytic Mechanism of Amphiphilic Antimicrobial β-Stranded [KL]n_n Peptides

Amphipathic peptides can act as antibiotics due to membrane permeabilization. KL peptides with the repetitive sequence [Lys-Leu]$_n$-NH$_2$ form amphipathic β-strands in the presence of lipid bilayers. As they are known to kill bacteria in a peculiar length-dependent manner, we suggest here several different functional models, all of which seem plausible, including a carpet mechanism, a β-barrel pore, a toroidal wormhole, and a β-helix. To resolve their genuine mechanism, the activity of KL peptides with lengths from 6–26 amino acids (plus some inverted LK analogues) was systematically tested against bacteria and erythrocytes. Vesicle leakage assays served to correlate bilayer thickness and peptide length and to examine the role of membrane curvature and putative pore diameter. KL peptides with 10–12 amino acids showed the best therapeutic potential, i.e., high antimicrobial activity and low hemolytic side effects. Mechanistically, this particular window of an optimum β-strand length around 4 nm (11 amino acids × 3.7 Å) would match the typical thickness of a lipid bilayer, implying the formation of a transmembrane pore. Solid-state $^{15}$N- and $^{19}$F-NMR structure analysis, however, showed that the KL backbone lies flat on the membrane surface under all conditions. We can thus refute any of the pore models and conclude that the KL peptides rather disrupt membranes by a carpet mechanism. The intriguing length-dependent optimum in activity can be fully explained by two counteracting effects, i.e., membrane binding versus amyloid formation. Very short KL peptides are inactive, because they are unable to bind to the lipid bilayer as flexible β-strands, whereas very long peptides are inactive due to vigorous pre-aggregation into β-sheets in solution

A Survival Analysis of Different Pulp Therapies in Decayed Primary Teeth

Objective: To identify the clinical and radiographic conditions associated with failure of pulp therapy in primary teeth through a survival analysis. Material and Methods: A total of 1000 records of children assisted at the pediatric dentistry clinic of the Federal University of Parana, Brazil, from the years 2000 to 2010, were analyzed. The mean evaluation time was 10.61 months (minimum/maximum: 1/28) from the report of pulp therapy. The different types of treatments analyzed included indirect pulp treatment (IPT), direct pulp treatment (DPT), pulpotomy and pulpectomy. The Kaplan-Meyer method and log-rank test were used for the survival analysis. Exodontia was considered as the outcome variable and censors included: traumatic tooth loss, presence of the tooth in the oral cavity and physiologic tooth exfoliation. Results: A total of 122 records reporting pulp therapy in the primary teeth were selected. From this, 16 teeth (13.12%) were extracted. Survival analysis showed that pulpectomy presented lower survival rates when compared to conservative therapies (p=0.0297). Teeth with furcal lesions and pathological root resorption before pulp therapy had lower survival rates when compared to those that did not present these conditions (P=0.006). Presence of fistula and abscess after pulp therapy were also associated with lower survival rates (P=0.0062 and 0.0143, respectively). Conclusion: Signals of pulp necrosis were associated to lower survival rates in primary teeth submitted to pulp therapy