Modified Surface Relief Layer Created by Holographic Lithography: Application to Selective Sodium and Potassium Sensing

Point-of-care diagnostics will rely upon the development of low-cost, noncomplex, and easily integrated systems in order to examine biological samples such as blood and urine obtained from the patient. The development of metal ion sensors is a subject of significant relevance for physiological samples. The level of different blood electrolytes, mainly H+, Na+, K+ and Cl− is considerably used to monitor irregular physiologies. The particular challenge in biosensing, and in fact for any other sensor, is signal differentiation between non-specifically bound material and the specific detecting of the target molecule/ion. The biosensors described in this paper are fabricated by a holographic recording of surface relief structures in a photopolymer material. The surface structures are modified by coating with either dibenzo-18-crown-6 (DC) or tetraethyl 4-tert-butylcalix[4]arene (TBC), which are embedded in a polymer matrix. Interrogation of these structures by light allows indirect measurement of the concentration of the analyte. The influence of polymer matrices with different porosities, plasticised polyvinyl chloride (PVC) and a sol-gel matrix, on the performance of the sensors for detection of K+ and Na+ is examined. Here we demonstrate a proof of concept that by using a matrix with higher porosity one can increase the sensitivity of the sensor. The results showed that the DC sensing layer provides a selective response to K+ over Na+ and the TBC modified grating is more responsive to Na+ over K+. The sensor responds to K+ and Na+ within the physiological concentration range

Depressive symptoms and perceived burdens related to being a student: Survey in three European countries

Mikolajczyk RT, Maxwell AE, Naydenova V, Meier S, El Ansari W. Depressive symptoms and perceived burdens related to being a student: survey in three European countries. Clinical Practice and Epidemiology in Mental Health. 2008;4(1): 19.Background: Despite a high prevalence of depressive symptoms among university students, few studies have examined how this mental health problem is associated with perceived stress and perceived burdens related to being a student. Methods: We conducted a cross-sectional study of 2,103 first year students from one western (Germany), one central (Poland), and one south-eastern European country (Bulgaria). The self-administered questionnaires included the modified Beck Depression Inventory and Cohen's Perceived Stress Scale. A 13 item scale measured perceived burdens related to being a student with four subscales: ''Course work'', ''Relationships'', ''Isolation'', and ''Future''. Results: Depressive symptoms were highly prevalent in all three countries (M-BDI ≥35: 34% in Poland, 39% in Bulgaria, and 23% in Germany). Students felt more burdened by course work and bad job prospects (''Future'') than by relationship problems or by feelings of isolation. The perceived burdens subscales ''Future'', ''Relationship'' and ''Isolation'' remained associated with depressive symptoms after adjusting for perceived stress, which displayed a strong association with depressive symptoms. The association between perceived stress and depressive symptoms differed by gender. These findings were similar in all three countries. Conclusion: Perceived burdens related to studying are positively associated with higher depression scores among students, not only by mediation through perceived stress but also directly. While the strong association between perceived stress and depressive symptoms suggests the need for interventions that improve stress management, perceived burdens should also be addressed

Сross-analysis of big data in accreditation of health specialists

Objective: The relevance of this study is due to the mass accreditation of health professionals that is developing in Russia, which requires innovative measurement tools and opens new opportunities for a well-founded cross-analysis of specialists’ professional readiness quality. Purpose of the study: The purpose of this article is to present approved methodical approaches to the transformation of accreditation data into a format suitable for secondary analysis of medical schools graduates quality based on the requirements of Professional Standards. Method: The leading methods of secondary data analysis are: a) codification of indicators in the primary data accumulation array; b) statistical processing of study results (evaluation of the relationships between the arrays of primary data accumulation and instrumental data, the correlation of test scores obtained by accreditation results with the labor functions of Professional Standards); c) the creation of representative samples for data analysis. The implementation of methods is carried out in the mode of working with arrays of big data, which also uses the method of cross-analysis to identify additional factors that affect to specialists’ professional readiness quality. Results: As a results of the research, there were: 1) approaches to the codification of data in the array and their secondary analysis were developed; 2) three samples were constructed with an estimation of representativeness for different strata, including subjects, assignments and corresponding labor functions; 3) the matrix of primary data in the specialty “Pediatrics” was verified using the example of the results of students from 50 medical universities in Russia. Conclusion: Approbation of methods of secondary data analysis conducted on representative samples of the subjects showed the effectiveness of the developed approaches that should be used when analyzing large data sets in the procedures of certification or accreditation. The materials of the article can be useful for specialists in the field of assessing the quality of education or assessing the professional readiness of health professionals, managers, professors and pedagogical staff of medical schools, specialists of centers for independent assessment of qualifications. © 2018, Modestum Ltd.. All rights reserved

Synthesis of Fast Curing, Water-Resistant and Photopolymerizable Glass for Recording of Holographic Structures by One- and Two-Photon Lithography

Advancements in hybrid sol-gel technology have provided a new class of holographic materials as photopolymerizable glasses. Recently, a number of photosensitive glass compositions with high dynamic range and high spatial resolution have been reported and their excellent capability for volume holography has been demonstrated. Nevertheless, challenges remain, particularly in relation to the processing time and environmental stability of these materials, that strongly affect the performance and durability of the fabricated holograms. State-of-the-art photopolymerizable glasses possess long curing times (few days) required to achieve thick films, thus limiting the industrial implementation of this technology and its commercial viability. This article presents a novel, fast curing, water-resistant, photopolymerizable hybrid sol-gel (PHSG) for holographic applications. Due to introducing an amine-based modifier that increases the condensation ability of the sol-gel network, this PHSG overcomes the problem of long curing time and can readily produce thick (up to a few hundred micrometers) layers without cracking and breaking. In addition, this PHSG exhibits excellent water-resistance, providing stable performance of holographic gratings for up to 400 h of immersion in water. This finding moves photopolymerizable glasses to the next development stage and renders the technology attractive for the mass production of holographic optical elements and their use across a wide number of outdoor applications

Self-processing photopolymer materials for versatile design and fabrication of holographic sensors and interactive holograms

The aim of this paper is to discuss the benefits as well as the limitations of utilizing photopolymer materials in the design of holograms that are responsive to changes in their environment, such as changes in the concentration of a specific substance, temperature, and pressure. Three different case studies are presented, including both surface and volume phase holograms, in order to demonstrate the flexibility in the approach of utilizing holographic photopolymers for the design of sensors and interactive optical devices. First, a functionalized surface relief hologram is demonstrated to operate as an optical sensor for the detection of metal ions in water. The sensitivity and selectivity of the sensor are investigated. The second example demonstrates a volume transmission hologram recorded in a temperature-sensitive photopolymer and the memory effects of its exposure to elevated temperature. Finally, a pressure-sensitive reflection hologram that changes color under application of pressure is characterized, and its potential application in document authentication is described

The power of data mining in diagnosis of childhood pneumonia

Childhood pneumonia is the leading cause of death of children under the age of five globally. Diagnostic information on presence of infection, severity and aetiology (bacterial versus viral) is crucial for appropriate treatment. However, the derivation of such information requires advanced equipment (such as X-rays) and clinical expertise to correctly assess observational clinical signs (such as chest indrawing); both of these are often unavailable in resource-constrained settings. In this study, these challenges were addressed through the development of a suite of data mining tools, facilitating automated diagnosis through quantifiable features. Findings were validated on a large dataset comprising 780 children diagnosed with pneumonia, and 801 age-matched healthy controls. Pneumonia was identified via four quantifiable vital signs (98.2% sensitivity and 97.6% specificity). Moreover, it was shown that severity can be determined through a combination of three vital signs and two lung sounds (72.4% sensitivity and 82.2% specificity); addition of a conventional biomarker (Creactive protein) further improved severity predictions (89.1% sensitivity and 81.3% specificity). Finally, we demonstrated that aetiology can be determined using three vital signs and a newly proposed biomarker (Lipocalin-2) (81.8% sensitivity and 90.6% specificity). These results suggest that a suite of carefully designed machine learning tools can be used to support multi-faceted diagnosis of childhood pneumonia in resource-constrained settings, compensating for the shortage of expensive equipment and highly trained clinicians

Setting-up of the Database on the Nucleotide Sequences of the Genomes of the Strains of Bacterial and Viral Infections Agents of the I–II Pathogenicity Groups

Set-up is database containing characteristics of variable tandem repeats, oligo-nucleotide primers and probes of the genomes of the strains bacterial and viral infections agents of the I-II pathogenicity groups. It allows for accumulation of information on genome regions. Using the incorporated VBA one can rapidly analyze the data and carry out substantiated calculation of gene-diagnostic preparations based on various PCR frameworks

Current State of Dengue Fever Laboratory Diagnostics (Scientific Review)

The paper contains the data on the distribution, morphology and classification of Dengue viruses as well as laboratory diagnostics of the diseases caused by them using conventional and modern virology methods. Discussed is the possibility of application of various laboratory techniques at different stages from the onset of the disease. In addition, up to date cases of Dengue fever importation into the territory of the Russian Federation are becoming more frequent which testifies to the need of the development of domestically produced test-system, as well as introduction of modern technologies of virus isolation on the biological model or cell culture into the practice of plague control institutions

Detection of vancomycin-resistant Enterococcus faecium hospital-adapted lineages in municipal wastewater treatment plants indicates widespread distribution and release into the environment.

Vancomycin-resistant Enterococcus faecium (VREfm) is a leading cause of healthcare-associated infection. Reservoirs of VREfm are largely assumed to be nosocomial although there is a paucity of data on alternative sources. Here, we describe an integrated epidemiological and genomic analysis of E. faecium associated with bloodstream infection and isolated from wastewater. Treated and untreated wastewater from 20 municipal treatment plants in the East of England, United Kingdom was obtained and cultured to isolate E. faecium, ampicillin-resistant E. faecium (AREfm), and VREfm. VREfm was isolated from all 20 treatment plants and was released into the environment by 17/20 plants, the exceptions using terminal ultraviolet light disinfection. Median log10 counts of AREfm and VREfm in untreated wastewater from 10 plants in direct receipt of hospital sewage were significantly higher than 10 plants that were not. We sequenced and compared the genomes of 423 isolates from wastewater with 187 isolates associated with bloodstream infection at five hospitals in the East of England. Among 481 E. faecium isolates belonging to the hospital-adapted clade, we observed genetic intermixing between wastewater and bloodstream infection, with highly related isolates shared between a major teaching hospital in the East of England and 9/20 plants. We detected 28 antibiotic resistance genes in the hospital-adapted clade, of which 23 were represented in bloodstream, hospital sewage, and municipal wastewater isolates. We conclude that our findings are consistent with widespread distribution of hospital-adapted VREfm beyond acute healthcare settings with extensive release of VREfm into the environment in the East of England

Ports and Dynamics Colonial: the main ports of the captaincies of northern Brazil

En este artículo se presenta un estudio sobre los principales puertos y lugares de atraque existentes a lo largo de la costa del norte de Brasil, especialmente entre las capitanías de Pernambuco y Ceará, al objeto de probar la dinámica que implican la organización y funcionamiento de los puertos coloniales, dando énfasis en temas acerca de la logística portuaria.This article presents a study on the main ports and places to existing berthing along the coast of northern Brazil, especially among the captaincies of Pernambuco and Ceará, seeking to show the dynamics involving the organization and functioning of the colonial ports, giving emphasis on issues about port logistics