119 research outputs found
Tunable single- and dual-wavelength SHG from diode-pumped PPKTP waveguides
A compact, all-room-temperature, widely tunable, continuous wave laser source in the green spectral region (502.1–544.2 nm) with a maximum output power of 14.7 mW is demonstrated. This was made possible by utilizing second-harmonic generation (SHG) in a periodically poled potassium titanyl phosphate (PPKTP) crystal waveguide pumped by a quantum-well external-cavity fiber-coupled diode laser and exploiting the multimode-matching approach in nonlinear crystal waveguides. The dual-wavelength SHG in the wavelength region between 505.4 and 537.7 nm (with a wavelength difference ranging from 1.8 to 32.3 nm) and sum-frequency generation in a PPKTP waveguide is also demonstrated
Magnetic structural effect in nonequilibrium defective solids
Scientific study of the effect of structural memory of nonequilibrium
defective solids about the processing in magnetic field (the magnetic
structural effect (MSE) was continued in this paper. The study was aimed to
reveal the universal nature of the MSE, which was investigated in several new
nonequilibrium defective solids. The results of investigation of the processing
in the vortical magnetic field (PVMF) and its effect on the structure of the
natural magnetite Fe3O4 and the SnO2 films were presented. The methods of
Mössbauer and X-ray spectroscopy were used. The PVMF reduction of a
defectiveness of Fe3O4 structure in the magnetite was detected. The MSE was
also observed in the Mössbauer spectra of diamagnetic tin oxide SnO2 films
after the PVMF. One of the possible explanations of the MSE was given in the
paper.Comment: 6 pages, 6 figures, 3 table
New generalized fuzzy metrics and fixed point theorem in fuzzy metric space
In this paper, in fuzzy metric spaces (in the sense of Kramosil and Michalek (Kibernetika 11:336-344, 1957)) we introduce the concept of a generalized fuzzy metric which is the extension of a fuzzy metric. First, inspired by the ideas of Grabiec (Fuzzy Sets Syst. 125:385-389, 1989), we define a new G-contraction of Banach type with respect to this generalized fuzzy metric, which is a generalization of the contraction of Banach type (introduced by M Grabiec). Next, inspired by the ideas of Gregori and Sapena (Fuzzy Sets Syst. 125:245-252, 2002), we define a new GV-contraction of Banach type with respect to this generalized fuzzy metric, which is a generalization of the contraction of Banach type (introduced by V Gregori and A Sapena). Moreover, we provide the condition guaranteeing the existence of a fixed point for these single-valued contractions. Next, we show that the generalized pseudodistance J:X×X→[0,∞) (introduced by Włodarczyk and Plebaniak (Appl. Math. Lett. 24:325-328, 2011)) may generate some generalized fuzzy metric NJ on X. The paper includes also the comparison of our results with those existing in the literature
Typological classification of health groups of schoolboys with comorbidity and behavioural risk factors
The purpose of study is estimation of a state of health by typological classification Complex examination of 142 girls and 116 boys in the age of 14-17 years has shown, that 2,1 % of girls and 11,2% of boys have la type of the status of health without risk factors. Premorbid types (lla, lib, lie) were in 20,4% and 25,9% accordingly. Among schoolboys persons with monomorbid (40,9% and 43,0 %) and bimorbid (23,9% and 12,1%) types of the status of health (Ilia and lllb) prevailed. Comorbidity is revealed in 68,3% of girls and 52,3% of boys. A prevailing pathology were dysplasia of connective tissue.Цель исследования оценить состояние здоровья подростков в соответствии с типологической классификацией. Комплексное обследование 142 девонек и 116 мальчиков в возрасте 14-17 лет показало, что 2,1 % девочек и 11,2% мальчиков относятся к la типу статуса здоровья без факторов риска. Преморбидные типы (На, НЬ, Не) были в 20,4% и 25,9% соответственно. Среди школьников преобладали лица с мономорбидным (40,9% и 43,0%) и биморбидным (23,9% и 12,1 %) типами статуса здоровья (Ша и lllb). Коморбидная патология выявлена в 68,3% девочек и 52,3% мальчиков. Преобладающей патологией была дисплазия соединительной ткани
Fixed point theorems for complex non-self mappings satisfying an implicit relation in Kaleva-Seikkala’s type fuzzy metric spaces
Robust regression for periodicity detection in non-uniformly sampled time-course gene expression data
<p>Abstract</p> <p>Background</p> <p>In practice many biological time series measurements, including gene microarrays, are conducted at time points that seem to be interesting in the biologist's opinion and not necessarily at fixed time intervals. In many circumstances we are interested in finding targets that are expressed periodically. To tackle the problems of uneven sampling and unknown type of noise in periodicity detection, we propose to use robust regression.</p> <p>Methods</p> <p>The aim of this paper is to develop a general framework for robust periodicity detection and review and rank different approaches by means of simulations. We also show the results for some real measurement data.</p> <p>Results</p> <p>The simulation results clearly show that when the sampling of time series gets more and more uneven, the methods that assume even sampling become unusable. We find that M-estimation provides a good compromise between robustness and computational efficiency.</p> <p>Conclusion</p> <p>Since uneven sampling occurs often in biological measurements, the robust methods developed in this paper are expected to have many uses. The regression based formulation of the periodicity detection problem easily adapts to non-uniform sampling. Using robust regression helps to reject inconsistently behaving data points.</p> <p>Availability</p> <p>The implementations are currently available for Matlab and will be made available for the users of R as well. More information can be found in the web-supplement <abbrgrp><abbr bid="B1">1</abbr></abbrgrp>.</p
The risk of cryptorchidism among sons of women working in horticulture in Denmark: a cohort study
<p>Abstract</p> <p>Background</p> <p>Androgens are crucial for normal testicular descent. Studies show that some pesticides have estrogenic or antiandrogenic effects, and that female workers exposed to pesticides have increased risk of having a boy with cryptorchidism. The main objective of the present study was to investigate whether pregnant women exposed to pesticides due to their work in horticulture experience excess risk of having sons with cryptorchidism.</p> <p>Methods</p> <p>We conducted a cohort study of pregnant women working in horticulture using four cohorts including one cohort established with data from the departments of occupational medicine in Jutland and Funen and three existing mother-child cohorts (n = 1,468). A reference group was established from the entire Danish population of boys born in the period of 1986-2007 (n = 783,817). Nationwide Danish health registers provided information on birth outcome, cryptorchidism diagnosis and orchiopexy. The level of occupational exposure to pesticides was assessed by expert judgment blinded towards outcome status. Risk of cryptorchidism among exposed horticulture workers compared to the background population and to unexposed horticulture workers was assessed by Cox regression models.</p> <p>Results</p> <p>Pesticide exposed women employed in horticulture had a hazard ratio (HR) of having cryptorchid sons of 1.39 (95% CI 0.84; 2.31) and a HR of orchiopexy of 1.34 (0.72; 2.49) compared to the background population. Analysis divided into separate cohorts revealed a significantly increased risk of cryptorchidism in cohort 2: HR 2.58 (1.07;6.20) and increased risk of orchiopexy in cohort 4: HR 2.76 (1.03;7.35), but no significant associations in the other cohorts. Compared to unexposed women working in horticulture, pesticide exposed women had a risk of having sons with cryptorchidism of 1.34 (0.30; 5.96) and of orchiopexy of 1.93 (0.24;15.4).</p> <p>Conclusions</p> <p>The data are compatible with a slightly increased risk of cryptorchidism in sons of women exposed to pesticides by working in horticulture.</p
Management of cryptorchidism: a survey of clinical practice in Italy
<p>Abstract</p> <p>Background</p> <p>An evidence-based Consensus on the treatment of undescended testis (UT) was recently published, recommending to perform orchidopexy between 6 and 12 months of age, or upon diagnosis and to avoid the use of hormones. In Italy, current practices on UT management are little known. Our aim was to describe the current management of UT in a cohort of Italian children in comparison with the Consensus guidelines. As management of retractile testis (RT) differs, RT cases were described separately.</p> <p>Methods</p> <p>Ours is a retrospective, multicenter descriptive study. An online questionnaire was filled in by 140 Italian Family Paediatricians (FP) from <it>Associazione Culturale Pediatri </it>(ACP), a national professional association of FP. The questionnaire requested information on all children with cryptorchidism born between 1/01/2004 and 1/01/2006. Data on 169 children were obtained. Analyses were descriptive.</p> <p>Results</p> <p>Overall 24% of children were diagnosed with RT, 76% with UT. Among the latter, cryptorchidism resolved spontaneously in 10% of cases at a mean age of 21.6 months. Overall 70% of UT cases underwent orchidopexy at a mean age of 22.8 months (SD 10.8, range 1.2-56.4), 13% of whom before 1 year. The intervention was performed by a paediatric surgeon in 90% of cases, with a success rate of 91%. Orchidopexy was the first line treatment in 82% of cases, while preceded by hormonal treatment in the remaining 18%. Hormonal treatment was used as first line therapy in 23% of UT cases with a reported success rate of 25%. Overall, 13 children did not undergo any intervention (mean age at last follow up 39.6 months). We analyzed the data from the 5 Italian Regions with the largest number of children enrolled and found a statistically significant regional difference in the use of hormonal therapy, and in the use of and age at orchidopexy.</p> <p>Conclusions</p> <p>Our study showed an important delay in orchidopexy. A quarter of children with cryptorchidism was treated with hormonal therapy. In line with the Consensus guidelines, surgery was carried out by a paediatric surgeon in the majority of cases, with a high success rate.</p
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