Detection of magnetic iron nanoparticles by single-particle ICP-TOFMS: case study for a magnetic filtration medical device.

Nanoparticles are increasingly used in medical products and devices. Their properties are critical for such applications, as particle characteristics determine their interaction with the biological system, and, therefore, the performance and safety of the final product. Among the most important nanoparticle characteristics and parameters are particle mass distribution, composition, total particle mass, and number concentration. In this study, we utilize single-particle inductively coupled plasma time-of-flight mass spectrometry (spICP-TOFMS) for the characterization of inorganic nanoparticles in complex biological fluids. We report online microdroplet calibration for reference-nanomaterial-free and matrix-matched calibration of carbon-coated iron carbide nanoparticles (C/Fe3C NPs). As a case study, we analyze C/Fe3C NPs designed for targeted blood purification. Through the analysis of NP mass distributions, we study the effect of the NP surface modification on aggregation of C/Fe3C NPs in whole blood. We also demonstrate the efficiency of removal of coated C/Fe3C NP from saline by magnetically enhanced filters. Magnetic filtering is shown to reduce the mass concentration of detectable C/Fe3C NPs by 99.99 ± 0.01% in water.

Continued dysregulation of the B cell lineage promotes multiple sclerosis activity despite disease modifying therapies.

A clear understanding of the origin and role of the different subtypes of the B cell lineage involved in the activity or remission of multiple sclerosis (MS) is important for the treatment and follow-up of patients living with this disease. B cells, however, are dynamic and can play an anti-inflammatory or pro-inflammatory role, depending on their milieu. Depletion of B cells has been effective in controlling the progression of MS, but it can have adverse side effects. A better understanding of the role of the B cell subtypes, through the use of surface biomarkers of cellular activity with special attention to the function of memory and other regulatory B cells (Bregs), will be necessary in order to offer specific treatments without inducing undesirable effects.

Efectividad de las intervenciones estructurales para la promoción del uso del preservativo en adolescentes y jóvenes: revisión sistemática / Effectiveness of structural interventions to promote condom use in adolescents and young people: Systematic Review

RESUMEN Objetivo Evaluar la efectividad de las intervenciones de tipo estructural o multicomponente dirigidas al incremento del uso del preservativo en adolescentes y jóvenes, identificar las estrategias que conforman las intervenciones evaluadas y reconocer los modelos teóricos que sustentan dichas intervenciones. Metodología Diseño: revisión sistemática de la literatura. Fuente de datos: se consultaron las bases de datos MEDLINE vía OVID, Embase y CENTRAL para buscar estudios sobre intervenciones dirigidas al incremento del uso del preservativo en adolescentes y jóvenes. Selección de estudios: se seleccionaron un total de 7 investigaciones primarias donde se evaluaba el efecto de una intervención estructural o multicomponente para incrementar el uso del preservativo en adolescentes y jóvenes. La calidad de los estudios fue evaluada usando la herramienta para valoración de riesgo de sesgos de Cochrane. Resultados Cinco investigaciones mostraron cambios en los porcentajes del uso del preservativo con valores entre 53 % y el 68 %. Las intervenciones planteadas orientaban sus acciones más a nivel individual con estrategias como: educación sobre salud sexual, consejería en salud reproductiva, conocimientos acerca del preservativo, conocimientos acerca de las ITS/VIH. A nivel organizacional y del entorno iban dirigidas a la provisión de preservativos. Los modelos teóricos planteados en los estudios están centrados en la conducta humana, comportamiento del individuo y el aprendizaje social. Discusión Las intervenciones de tipo estructural que tienen como fin el incremento del uso del preservativo en adolescentes y jóvenes parecen mostrar cambios significativos a nivel individual, pero se desconocen los posibles cambios generados a nivel de la organización y del entorno.(AU)

ABSTRACT Objective Evaluate the effectiveness of structural or multicomponent interventions aimed at increasing the use of condoms in adolescents and young adults, identifying the strategies that form the interventions evaluated, and recognizing the theoretical models that support these interventions. Methodology Design: Systematic review of literature. Data source: MEDLINE databases were consulted via OVID, Embase, and CENTRAL in order to search for studies on interventions aimed at increasing the use of condoms in adolescents and young adults. Selection of studies: A total of 7 primary investigations were selected, in which the effect of a structured or multicomponent intervention to increase the use of condoms in adolescents and young adults was evaluated. The quality of the studies was evaluated using the Cochrane bias risk assessment. Results Five investigations show changes in the percentages of condom use with values between 53% and 68%. The interventions targeted guided their actions more at individual level with strategies such as sexual health education, reproductive health counseling, knowledge about the condom, knowledge about STIs / HIV, than at organizational and environ-mental levels, which were aimed at the provision of condoms. The theoretical models proposed in the studies are focused on human behavior, individual behavior, and social learning. Conclusion Structural interventions that aim to increase the use of condoms in adolescents and young adults seem to show significant changes at individual level, but possible changes generated at both organization and environment levels are unknown.(AU)

[Effectiveness of structural interventions to promote condom use in adolescents and young people: Systematic Review]. / Efectividad de las intervenciones estructurales para la promoción del uso del preservativo en adolescentes y jóvenes: revisión sistemática.

OBJECTIVE: Evaluate the effectiveness of structural or multicomponent interventions aimed at increasing the use of condoms in adolescents and young adults, identifying the strategies that form the interventions evaluated, and recognizing the theoretical models that support these interventions. METHODOLOGY: Design: Systematic review of literature. Data source: MEDLINE databases were consulted via OVID, Embase, and CENTRAL in order to search for studies on interventions aimed at increasing the use of condoms in adolescents and young adults. Selection of studies: A total of 7 primary investigations were selected, in which the effect of a structured or multicomponent intervention to increase the use of condoms in adolescents and young adults was evaluated. The quality of the studies was evaluated using the Cochrane bias risk assessment. RESULTS: Five investigations show changes in the percentages of condom use with values between 53% and 68%. The interventions targeted guided their actions more at individual level with strategies such as sexual health education, reproductive health counseling, knowledge about the condom, knowledge about STIs / HIV, than at organizational and environ-mental levels, which were aimed at the provision of condoms. The theoretical models proposed in the studies are focused on human behavior, individual behavior, and social learning. CONCLUSION: Structural interventions that aim to increase the use of condoms in adolescents and young adults seem to show significant changes at individual level, but possible changes generated at both organization and environment levels are unknown.

OBJETIVO: Evaluar la efectividad de las intervenciones de tipo estructural o multicomponente dirigidas al incremento del uso del preservativo en adolescentes y jóvenes, identificar las estrategias que conforman las intervenciones evaluadas y reconocer los modelos teóricos que sustentan dichas intervenciones. METODOLOGÍA: Diseño: revisión sistemática de la literatura. Fuente de datos: se consultaron las bases de datos MEDLINE vía OVID, Embase y CENTRAL para buscar estudios sobre intervenciones dirigidas al incremento del uso del preservativo en adolescentes y jóvenes. Selección de estudios: se seleccionaron un total de 7 investigaciones primarias donde se evaluaba el efecto de una intervención estructural o multicomponente para incrementar el uso del preservativo en adolescentes y jóvenes. La calidad de los estudios fue evaluada usando la herramienta para valoración de riesgo de sesgos de Cochrane. RESULTADOS: Cinco investigaciones mostraron cambios en los porcentajes del uso del preservativo con valores entre 53 % y el 68 %. Las intervenciones planteadas orientaban sus acciones más a nivel individual con estrategias como: educación sobre salud sexual, consejería en salud reproductiva, conocimientos acerca del preservativo, conocimientos acerca de las ITS/VIH. A nivel organizacional y del entorno iban dirigidas a la provisión de preservativos. Los modelos teóricos planteados en los estudios están centrados en la conducta humana, comportamiento del individuo y el aprendizaje social. DISCUSIÓN: Las intervenciones de tipo estructural que tienen como fin el incremento del uso del preservativo en adolescentes y jóvenes parecen mostrar cambios significativos a nivel individual, pero se desconocen los posibles cambios generados a nivel de la organización y del entorno.

Role of CXCL13 in the formation of the meningeal tertiary lymphoid organ in multiple sclerosis.

Immunomodulatory therapies available for the treatment of patients with multiple sclerosis (MS) accomplish control and neutralization of peripheral immune cells involved in the activity of the disease cascade but their spectrum of action in the intrathecal space and brain tissue is limited, taking into consideration the persistence of oligoclonal bands and the variation of clones of lymphoid cells throughout the disease span. In animal models of experimental autoimmune encephalomyelitis (EAE), the presence of CXCL13 has been associated with disease activity and the blockade of this chemokine could work as a potential complementary therapeutic strategy in patients with MS in order to postpone disease progression. The development of therapeutic alternatives with ability to modify the intrathecal inflammatory activity of the meningeal tertiary lymphoid organ to ameliorate neurodegeneration is mandatory.

Estudio bibliométrico de la producción científica encontrada en Scopus y Web Of Science sobre rehabilitación vocal fisiológica / Bibliometric analysis of the scientific production found in Scopus and Web Of Science about physiological vocal rehabilitation

Introducción: El presente estudio analiza la producción científica internacional encontrada en Scopus y Web of Science relacionada con la Corriente de Rehabilitación Vocal Fisiológica en el periodo 2006 a 2015. Metodología: Estudio exploratorio-descriptivo con 3 fases de desarrollo: a) selección de palabras clave y criterios de búsqueda; b) búsqueda y sistematización de información; c) análisis de la información. Resultados: La mayor producción científica se identifica en la herramienta de búsqueda Scopus bajo el criterio de búsqueda «voice therapy». Se analizaron un total de 167 publicaciones, realizando correlaciones a partir de las variables año, criterios de búsqueda, autores, factor de impacto por cuartil y por citación. Conclusión: Existe alta correlación y grado de solapamiento entre ambas bases de datos. Sin embargo, Scopus comparada con Web of Science, con relación a las líneas de la Corriente de Rehabilitación Vocal Fisiológica y para el periodo estudiado, presentó un mayor porcentaje de producción científica. Las líneas con mayor impacto científico son «terapia Lee Silverman» y «ejercicios de la función vocal». «Ejercicios TVSO» y «terapia de voz resonante», con menos porcentaje de publicaciones, desde 2011 incrementan progresivamente factores de alto impacto

Introduction: The present study looks at the international scientific production found in Scopus and Web of Science, related to the Physiological Vocal Rehabilitation Current in the period 2006-2015. Methodology: Exploratory-descriptive study with three phases of development: A) selection of keywords and search criteria; B) search and systematization of information; C) analysis of information. Results: The highest scientific production is identified in the Scopus search tool under the "voice therapy" search criterion. A total of 167 publications were analyzed, making correlations from the year, search criteria, authors, impact factor by quartile and by citation variables. Conclusion: There is a high correlation and degree of overlap between the two databases. However, Scopus compared to Web of Science, in relation to the Physiological Vocal Rehabilitation Current lines and for the period studied, presented a higher percentage of scientific production. The lines with the greatest scientific impact are "Lee Silverman therapy" and "vocal function exercises". "SOVT exercises" and "resonant voice therapy", with less percentage of publications, since 2011 progressively increase high impact factors

Revisión sistemática de la literatura sobre medidas aerodinámicas de la fonación / Systematic literature review on aerodynamic measures of the phonation

Objetivo: El presente estudio muestra una revisión sistemática de la literatura relacionada con las aplicaciones clínicas e investigativas de las medidas aerodinámicas de la fonación: presión subglótica, flujo transglótico y resistencia glótica. Metodología: La revisión se realizó en las bases de datos PubMed y Web Of Science con una ventana temporal 2000-2017. Todos los artículos revisados obtuvieron nivelI. Luego de realizar una evaluación crítica de la evidencia científica, fueron catalogados como estudios clínicos aleatorizados con diseños experimentales. Resultados: Se entregan a partir de la asociación de las medidas aerodinámicas con seis categorías de análisis: a)como método objetivo de evaluación clínica; b)estudios con profesionales de la voz cantada y hablada; c)aplicaciones clínicas e investigativas en patologías laríngeas funcionales; d)investigaciones en diferentes grupos etarios; e)estudios en laringes caninas, y f)estudios en ejercicios con tracto vocal semiocluido. Conclusiones: Se demuestra la objetividad de aplicar medidas aerodinámicas en los estudios de la voz patológica y profesional; las medidas aerodinámicas de la fonación pueden aplicarse en población tanto pediátrica como adulta, y en adultos mayores

Objective: The present study shows a systematic review of the literature, related to the clinical and investigative implementations of aerodynamic measurements of phonation: subglottic pressure, transglottic airflow and glottal resistance. Method: The review was performed in PubMed and Web of Science databases with a time window 2000-2017. All articles reviewed obtained levelI. After performing a critical assessment of the scientific evidence, articles were classified as randomized clinical studies with experimental designs. Results: They are delivered from the association of aerodynamic measurements with six categories of analysis: a)as an objective method for clinical evaluation; b)studies with professional singing and speaking voice users; c)clinical and research implementations in functional laryngeal pathologies; d)research in different age groups; e)studies in canine larynx; and f)studies in voice exercises with semi-occluded vocal tract. Conclusions: The objectivity of implementing aerodynamic measures in pathological and professional voice studies is demonstrated; the aerodynamic measures of phonation can be applied in the pediatric population, as well as in adults and the elderly

Factores asociados con la adherencia a la actividad física en pacientes con enfermedades crónicas no transmisibles / Factors associated with adherence to physical activity in patients with chronic non-communicable diseases

RESUMEN Objetivo Determinar los factores asociados a la adherencia a la actividad física en pacientes con enfermedades crónicas no transmisibles ECNT en la red de salud Ladera del municipio de Santiago de Cali. Métodos Se realizó un estudio de casos y controles con 268 adultos con diagnóstico de Diabetes o Hipertensión u obesidad, 134 casos y 134 controles de la red de salud E.S.E Ladera. Para el análisis univariado se realiza análisis de frecuencias y estadística descriptiva. En el análisis bivariado se aplican pruebas de Chi-cuadrado y t de Student, ambas con un IC del 95%, para el análisis Multivariado se realizó regresión logística binaria y se estimó la razón de probabilidad a través del Odds Ratio (OR). Resultados Factores con OR<1: la autopercepción del estado de salud, espacios adecuados para la actividad física, autocuidado de la salud, periodicidad de actividad, demostraron ser facilitadores para la adherencia a la actividad física. Los factores con OR>1: estar solo durante el día, haber dejado de realizar ejercicio físico, considerar el ejercicio físico poco importante, espacios inseguros, falta de prescripción del ejercicio, fueron barreras para la adherencia a la actividad física. Conclusiones Percibirse con buena calidad de vida, tener la actividad física programada por el sistema de salud y ambientes adecuados y seguros, facilitan la adherencia, mientras no pertenecer a un grupo familiar, no considerar la prescripción a la actividad física importante y estar en zonas inseguras, limitan la adherencia.(AU)

ABSTRACT Objective To determine the factors associated with adherence to physical activity in patients with chronic non-communicable diseases (CND) in the Ladera health network of the municipality of Santiago de Cali. Methods A case-control study was conducted with 268 adults diagnosed with diabetes, high blood pressure or obesity, 134 cases and 134 controls, treated at the Empresa Social del Estado (E.S.E) Ladera healthcare network. Univariate analysis included frequency analysis and descriptive statistics. Chi-square and t Student tests were applied for bivariate analysis, both with a 95% CI; binary logistic regression was performed for the multivariate analysis and probability was estimated using the Odds Ratio (OR). Results Factors with OR<1 -self-perception of physical condition, appropriate spaces for physical activity, self-care, and frequency of activity- promote adherence to physical activity. Factors with OR>1 -being alone during the day, having stopped doing physical exercise, considering physical exercise as unimportant, unsafe spaces, and lack of indication of exercise- were barriers to adherence to physical activity. Conclusions Perceiving oneself with good quality of life and having a physical activity prescription by the healthcare system, as well as adequate and safe environments, promote adherence. On the other hand, not belonging to a family group, considering physical activity prescription as unimportant and being in unsafe areas, hinder adherence.(AU)

Nondestructive in-line sub-picomolar detection of magnetic nanoparticles in flowing complex fluids.

Over the last decades, the use of magnetic nanoparticles in research and commercial applications has increased dramatically. However, direct detection of trace quantities remains a challenge in terms of equipment cost, operating conditions and data acquisition times, especially in flowing conditions within complex media. Here we present the in-line, non-destructive detection of magnetic nanoparticles using high performance atomic magnetometers at ambient conditions in flowing media. We achieve sub-picomolar sensitivities measuring ~30 nm ferromagnetic iron and cobalt nanoparticles that are suitable for biomedical and industrial applications, under flowing conditions in water and whole blood. Additionally, we demonstrate real-time surveillance of the magnetic separation of nanoparticles from water and whole blood. Overall our system has the merit of in-line direct measurement of trace quantities of ferromagnetic nanoparticles with so far unreached sensitivities and could be applied in the biomedical field (diagnostics and therapeutics) but also in the industrial sector.

[Factors associated with adherence to physical activity in patients with chronic non-communicable diseases]. / Factores asociados con la adherencia a la actividad física en pacientes con enfermedades crónicas no transmisibles.

OBJECTIVE: To determine the factors associated with adherence to physical activity in patients with chronic non-communicable diseases (CND) in the Ladera health network of the municipality of Santiago de Cali. METHODS: A case-control study was conducted with 268 adults diagnosed with diabetes, high blood pressure or obesity, 134 cases and 134 controls, treated at the Empresa Social del Estado (E.S.E) Ladera healthcare network. Univariate analysis included frequency analysis and descriptive statistics. Chi-square and t Student tests were applied for bivariate analysis, both with a 95% CI; binary logistic regression was performed for the multivariate analysis and probability was estimated using the Odds Ratio (OR). RESULTS: Factors with OR<1 -self-perception of physical condition, appropriate spaces for physical activity, self-care, and frequency of activity- promote adherence to physical activity. Factors with OR>1 -being alone during the day, having stopped doing physical exercise, considering physical exercise as unimportant, unsafe spaces, and lack of indication of exercise- were barriers to adherence to physical activity. CONCLUSIONS: Perceiving oneself with good quality of life and having a physical activity prescription by the healthcare system, as well as adequate and safe environments, promote adherence. On the other hand, not belonging to a family group, considering physical activity prescription as unimportant and being in unsafe areas, hinder adherence.

OBJETIVO: Determinar los factores asociados a la adherencia a la actividad física en pacientes con enfermedades crónicas no transmisibles ECNT en la red de salud Ladera del municipio de Santiago de Cali. MÉTODOS: Se realizó un estudio de casos y controles con 268 adultos con diagnóstico de Diabetes o Hipertensión u obesidad, 134 casos y 134 controles de la red de salud E.S.E Ladera. Para el análisis univariado se realiza análisis de frecuencias y estadística descriptiva. En el análisis bivariado se aplican pruebas de Chi-cuadrado y t de Student, ambas con un IC del 95%, para el análisis Multivariado se realizó regresión logística binaria y se estimó la razón de probabilidad a través del Odds Ratio (OR). RESULTADOS: Factores con OR<1: la autopercepción del estado de salud, espacios adecuados para la actividad física, autocuidado de la salud, periodicidad de actividad, demostraron ser facilitadores para la adherencia a la actividad física. Los factores con OR>1: estar solo durante el día, haber dejado de realizar ejercicio físico, considerar el ejercicio físico poco importante, espacios inseguros, falta de prescripción del ejercicio, fueron barreras para la adherencia a la actividad física. CONCLUSIONES: Percibirse con buena calidad de vida, tener la actividad física programada por el sistema de salud y ambientes adecuados y seguros, facilitan la adherencia, mientras no pertenecer a un grupo familiar, no considerar la prescripción a la actividad física importante y estar en zonas inseguras, limitan la adherencia.

Evidence of disease control: a realistic concept beyond NEDA in the treatment of multiple sclerosis.

Although no evidence of disease activity (NEDA) permits evaluation of response to treatment in the systematic follow-up of patients with multiple sclerosis (MS), its ability to accomplish detection of surreptitious activity of disease is limited, thus being unable to prevent patients from falling into a non-reversible progressive phase of disease. A protocol of evaluation based on the use of validated biomarkers that is conducted at an early stage of disease would permit the capture of abnormal neuroimmunological phenomena and lead towards intervention with modifying therapy before tissue damage has been reached.

Hollow Carbon Nanobubbles: Synthesis, Chemical Functionalization, and Container-Type Behavior in Water.

Thin-walled, hollow carbon nanospheres with a hydrophobic interior and good water dispersability can be synthesized in two steps: First, metal nanoparticles, coated with a few layers of graphene-like carbon, are selectively modified on the outside with a covalently attached hydrophilic polymer. Second, the metal core is removed at elevated temperature treatment with acid, leaving a well-defined carbon-based hydrophobic cavity. Loading experiments with the dye rhodamine B and doxorubicin confirmed the filling and release of a cargo and adjustment of a dynamic equilibrium (cargo-loaded versus release). Rhodamine B preferably accumulates in the interior of the bubbles. Filled nanobubbles allowed constant dye release into pure water. Studies of the concentration-dependent loading and release show an unusual hysteresis.

Application of the Prunus spp. Cyanide Seed Defense System onto Wheat: Reduced Insect Feeding and Field Growth Tests.

Many crops are ill-protected against insect pests during storage. To protect cereal grains from herbivores during storage, pesticides are often applied. While pesticides have an undoubtable functionality, increasing concerns are arising about their application. In the present study, we investigated a bioinspired cyanogenic grain coating with amygdalin as cyanogenic precursor mimicking the feeding-triggered release of hydrogen cyanide (HCN) found for example in bitter almonds. The multilayer coating consisted of biodegradable polylactic acid with individual layers containing amygdalin or ß-glucosidase which is capable of degrading amygdalin to HCN. This reaction occurred only when the layers were ruptured, e.g., by a herbivore attack. Upon feeding coated cyanogenic wheat grains to Tenebrio molitor (mealworm beetle), Rhizopertha dominica (lesser grain borer), and Plodia interpunctella (Indianmeal moth), their reproduction as well as consumption rate were significantly reduced, whereas germination ability increased compared to noncoated grains. In field experiments, we observed an initial growth delay compared to uncoated grains which became negligible at later growth stages. The here shown strategy to artificially apply a naturally occurring defense mechanisms could be expanded to other crops than wheat and has the potential to replace certain pesticides with the benefit of complete biodegradability and increased safety during storage.

DNA-Based Sensor Particles Enable Measuring Light Intensity in Single Cells.

"Lab on a particle" architecture is employed in designing a light nanosensor. Light-sensitive protecting groups are installed on DNA, which is encapsulated in silica particles, qualifying as a self-sufficient light sensor. The nanosensors allow measuring light intensity and duration in very small volumes, such as single cells, and store the irradiation information until readout.

Autologous Bone Marrow Transplantation in Multiple Sclerosis: Biomarker Relevance for Patient Recruitment and Follow up.

BACKGROUND: Despite the current availability of disease modifying therapies for the treatment of multiple sclerosis, there are still patients who suffer from severe neurological dysfunction in the relapsing-remitting or early progressive forms of the disease. For these patients autologous hematopoietic stem cell transplant offers an important therapeutic solution to prevent progression to irreversible disability. In spite of multiple studies in the last two decades, patient inclusion criteria, protocols for peripheral blood stem cell mobilization and bone marrow cell conditioning and methodology of follow up for autologous hematopoietic stem cell transplant in multiple sclerosis have not been strictly unified. METHODS: We reviewed five recent clinical studies that confirmed the positive outcome of transplant in spite of disclosing significant differences in methodology of enrollment including patient disease subtypes, disease duration range, disability, regimens of peripheral blood stem cell mobilization and bone marrow cell conditioning, scheduling of imaging studies after transplant, and absence of laboratory biomarkers consistently applied to these studies. RESULTS: Therapy with autologous hematopoietic stem cell transplant has shown best results among young individuals with severe relapsing-remitting or early progressive disease through its ability to maintain no evidence of disease activity status in a significantly higher proportion of patients after transplant in comparison to patients treated with disease modifying therapies. Important cross-sectional differences in the reviewed studies were found. CONCLUSION: A specific and careful selection of biomarkers, based on the current physiopathological mechanisms known to result in multiple sclerosis, will contribute to a better and earlier patient selection for autologous hematopoietic stem cell transplant and follow up process. An objective and measurable response could be obtained with the determination of biomarkers at the onset of treatment and after follow-up on reconstitution of the immune response. The application of such parameters could also help further our understanding of pathogenesis of the disease.

Detecting and Number Counting of Single Engineered Nanoparticles by Digital Particle Polymerase Chain Reaction.

The concentrations of nanoparticles present in colloidal dispersions are usually measured and given in mass concentration (e.g. mg/mL), and number concentrations can only be obtained by making assumptions about nanoparticle size and morphology. Additionally traditional nanoparticle concentration measures are not very sensitive, and only the presence/absence of millions/billions of particles occurring together can be obtained. Here, we describe a method, which not only intrinsically results in number concentrations, but is also sensitive enough to count individual nanoparticles, one by one. To make this possible, the sensitivity of the polymerase chain reaction (PCR) was combined with a binary (=0/1, yes/no) measurement arrangement, binomial statistics and DNA comprising monodisperse silica nanoparticles. With this method, individual tagged particles in the range of 60-250 nm could be detected and counted in drinking water in absolute number, utilizing a standard qPCR device within 1.5 h of measurement time. For comparison, the method was validated with single particle inductively coupled plasma mass spectrometry (sp-ICPMS).

Programmable living material containing reporter micro-organisms permits quantitative detection of oligosaccharides.

The increasing molecular understanding of many diseases today permits the development of new diagnostic methods. However, few easy-to-handle and inexpensive tools exist for common diseases such as food disorders. Here we present a living material based analytical sensor (LiMBAS) containing genetically modified bacteria (Escherichia coli) immobilized and protected in a thin layer between a nanoporous and support polymer membrane for a facile quantification of disease-relevant oligosaccharides. The bacteria were engineered to fluoresce in response to the analyte to reveal its diffusion behavior when using a blue-light source and optical filter. We demonstrated that the diffusion zone diameter was related semi-logarithmically to the analyte concentration. LiMBAS could accurately quantify lactose or galactose in undiluted food samples and was able to measure food intolerance relevant concentrations in the range of 1-1000 mM requiring a sample volume of 1-10 µL. LiMBAS was storable for at least seven days without losing functionality at 4 °C. A wide range of genetic tools for E. coli are readily available thus allowing the reprogramming of the material to serve as biosensor for other molecules. In combination with smartphones, an automated diagnostic analysis becomes feasible which would also allow untrained people to use LiMBAS.

Nonconventional MRI biomarkers for in vivo monitoring of pathogenesis in multiple sclerosis.

To date, biomarkers based on nonconventional MRI have not been standardized for diagnosis and follow-up of patients with multiple sclerosis (MS). The sequential monitoring of pathogenesis in MS by imaging of the normal appearing brain tissue is an important research tool in understanding the early stages of MS. In this review, we focus on the importance of deciphering the physiopathogenesis of the disease cascade in vivo based on imaging biomarkers that allow a correlation with immunohistochemistry and molecular biology findings in order to provide earlier clinical diagnosis and better individualization of treatment and follow-up in patients with MS. Among the nonconventional imaging techniques available, we remark on the importance of proton magnetic resonance spectroscopy imaging because of its ability to assist in the simultaneous evaluation of different events in the pathogenesis of MS that cannot be determined by conventional MRI. Nonconventional MRI and the use of novel contrast agents are expected to elucidate the process of neuroinflammation and excitotoxicity in vivo that characterizes MS, thus leading to more specific neuroprotective and immunomodulatory therapies and reducing progression toward disability.

Labeling milk along its production chain with DNA encapsulated in silica.

The capability of tracing a food product along its production chain is important to ensure food safety and product authenticity. For this purpose and as an application example, recently developed Silica Particles with Encapsulated DNA (SPED) were added to milk at concentrations ranging from 0.1 to 100 ppb (µg per kg milk). Thereby the milk, as well as the milk-derived products yoghurt and cheese, could be uniquely labeled with a DNA tag. Procedures for the extraction of the DNA tags from the food matrixes were elaborated and allowed identification and quantification of previously marked products by quantitative polymerase chain reaction (qPCR) with detection limits below 1 ppb of added particles. The applicability of synthetic as well as naturally occurring DNA sequences was shown. The usage of approved food additives as DNA carrier (silica = E551) and the low cost of the technology (<0.1 USD per ton of milk labeled with 10 ppb of SPED) display the technical applicability of this food labeling technology.

In vitro activation of NAD-dependent alcohol dehydrogenases by Nudix hydrolases is more widespread than assumed.

In the Gram-positive methylotroph Bacillus methanolicus, methanol oxidation is catalyzed by an NAD-dependent methanol dehydrogenase (Mdh) that belongs to the type III alcohol dehydrogenase (Adh) family. It was previously shown that the in vitro activity of B. methanolicus Mdh is increased by the endogenous activator protein Act, a Nudix hydrolase. Here we show that this feature is not unique, but more widespread among type III Adhs in combination with Act or other Act-like Nudix hydrolases. In addition, we studied the effect of site directed mutations in the predicted active site of Mdh and two other type III Adhs with regard to activity and activation by Act.