Estudio experimental de la adhesión interfacial del sistema Sn/Pb - Al2O3 asistido con láser

OpenAIRE

Guerrero, A; Puerta, J; Lira, J

2006-01-01

En el presente trabajo se propuso y construyó un diseño de cámara de experimentación que permitió realizar diferentes mediciones del ángulo de contacto. El substrato cerámico (Sn/Pb - Al2O3) fue previamente tratado con un láser de CO2 y sobre el mismo se depositó una aleación de Estaño-Plomo fundido empleando el método de la gota en reposo en alto vacío. Estas mediciones experimentales se realizaron con el fin de conocer el comportamiento físico-químico de la mojabilidad del sistema metal-cer...

Laser in medicine Láser en medicina

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Juan C. Cárdenas

1993-03-01

Full Text Available The fundamentals of laser functioning and a brief historic description on the subject are presented; laser Is classified according to emission potency, materials with which it is built and pulsation. Different mechanisms of action of laser as well as Its indications and contraindications are discussed. Emphasis is given to low-power laser. Local and foreign experiences with Its medlcal use are briefly described

Se revisan los principios fundamentales del funcionamiento del láser, se hace una breve revisión histórica del mismo y se lo clasifica de acuerdo con la potencia de emisión, los materiales de fabricación y la pulsación. Se enumeran los diferentes mecanismos de acción del láser y sus indicaciones y contraindicaciones haciendo énfasis en lo concerniente al láser de baja potencia, tanto pulsado como no pulsado; se alude a las experiencias nacionales y de otros países.

Láser helio-neón combinado con clorhexidina al 0,2 %.: Efectos clínicos y microbiológicos en el tratamiento de la gingivitis crónica

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Tatiana Peña Ruiz

Full Text Available La gingivitis crónica constituye una de las formas más frecuentes de enfermedad periodontal, caracterizada por la inflamación crónica de la encías, tumefacción, enrojecimiento y sangramiento. Su principal factor de riesgo lo constituye la microbiota del surco gingival, que resulta necesario, pero no suficiente para desencadenarla. Se realizó un ensayo clínico-terapéutico fase II, controlado, aleatorizado y a simple ciegas, para evaluar los efectos clínicos y microbiológicos del tratamiento combinado de la radiación láser helio-neón (He-Ne con la clorhexidina al 0,2 %. Todos los pacientes recibieron tratamiento inicial; al mes de finalizado este, se distribuyeron aleatoriamente en 2 grupos: un grupo estudio que recibió la combinación láser-neón y clorhexidina al 0,2 % y otro grupo control que solo recibió clorhexidina al 0,2 %. Se realizó una evaluación a los 15, 30 y 45 días, con criterios de eficacia clínicos y microbiológicos. Los resultados clínicos fueron satisfactorios en el grupo estudio con predominio de los morfotipos I, caracterizados por cocos gramnegativos y positivos, compatibles con un periodonto sano. Los eventos adversos detectados con esta terapéutica fueron mínimos, todos relacionados con la somnolencia.

Ser y acción en la obra del primer M. Blondel

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José Javier FERNÁNDEZ PEREIRA

2009-12-01

Full Text Available RESUMEN: La pregunta por el ser cuando se hace desde la filosofía de la acción, como la de M. Blondel en su tesis L'Action. Essai d'une critique de la vie et d'une science de lapratiquede 1893, adquiere un interés inédito pues al integrar las aportaciones de la crítica moderna puede contribuir al replanteamiento de los viejos problemas ontológicos para dar origen a un -realismo superior» con sentido para el hombre de hoy.De la fenomenología integral de la acción se llega inevitablemente al planteamiento necesario del problema del ser. Puesto que la acción implica siempre una opción que es emergente respecto a sus condiciones científicas de posibilidad, ésta se convierte en la condición necesaria para que del conocimiento del ser se pase al ser en el conocimiento. La libertad se pone así en el centro de la ontología sin que ésta pierda su rigor racional.ABSTRACT: When the question about the being is made from the point of view of the action philosophy, as the one made by M. Blondel in his thesis L'Action. Essai d'une critique de la vie et d'une science de lapratique in 1893, adquires an unusual interest.By putting together the contributions of modern critic, it may help us to consider again the oíd ontological problems and so give rise to a superior realism with meaning for up-to-date man.The action integral phenomenology takes us inevitably to a necessary reconsideration of the problem of being. Since the action always implies an emerging option regarding its scientific condition of possibility, it becomes the necessary condition for the knowledge of the being to turn into the being in the knowledge. Thus, freedom becomes the centre of ontology with no loss of its rational exactness.

Facile synthesis of Ag dendrites on Al foil via galvanic replacement reaction with [Ag(NH3)2]Cl for ultrasensitive SERS detecting of biomolecules

International Nuclear Information System (INIS)

Fu, Jiajia; Ye, Weichun; Wang, Chunming

2013-01-01

Symmetric silver dendrites have been synthesized on commercial aluminum foil via galvanic replacement reaction with [Ag(NH 3 ) 2 ]Cl. This process is facile and environmentally friendly, without the use of any templates, surfactants or oxidants, and also avoiding the introduction of fluoride anions as a strong toxicity resulting in hypocalcemia. The products were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM) and X-ray diffraction (XRD). SEM characterizations and electrochemical measurements including an electrochemical direct current polarization method and OCP-t technique demonstrate that chloride has proven to be the key factor to the formation of well-defined dendritic shape. The as-prepared Ag dendrites are developed as a surface-enhanced Raman scattering (SERS)-active platform for detection of folic acid, DNA and RNA with well resolved bands and high Raman intensities. The detection concentration for the three biomolecules reaches the level of 10 −12 M, and thus the symmetric silver dendrites can potentially be employed as effective SERS sensors for label-free and ultrasensitive biomolecule detection. - Highlights: • Simple galvanic replacement is used to synthesize Ag dendrites on commercial Al foils. • This method avoids the introduction of fluoride anions. • The as-prepared dendrites exhibit high SERS activities for biomolecules. • The detection concentration for the biomolecules reaches the level of 10 −12 M

La "historia de los omeyas de al-Andalus" en los Masalik al-Absar

OpenAIRE

Molina, Luis

2005-01-01

[ES]Los Masalik al-absar de Ibn Fadl Allah al-`Umari incluyen un breve resumen de la Historia de los omeyas de al-Andalus. En este trabajo se analizan las relaciones textuales entre ese pasaje y el Muqtabis de Ibn Hayyan, crónica que resulta ser la fuente casi única utilizada por al-`Umari para redactar ese capítulo. [EN]The Masalik al-absar by Ibn Fadl Allah al-`Umari contains a brief summary of the Umayyad history in al-Andalus. In this article, the textual relationship between this p...

Relación entre el proceso evolutivo del ser humano y su predisposición al cáncer

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Armando Ernesto Pérez Cala

2018-02-01

Full Text Available El cáncer se ha convertido en la primera causa de morbimortalidad en numerosos países. En las últimas décadas se ha asistido a un cambio en el paradigma conceptual de las enfermedades neoplásicas, que ahora se enfoca hacia la perspectiva ecológica-evolutiva de estas. Con el objetivo de analizar, con elementos actualizados, la relación entre el proceso evolutivo del ser humano y su predisposición al cáncer, se realizó una revisión sistemática de la literatura, a partir de tres bases de datos, Medline, Scopus, y SciELO. Se tuvieron en cuenta atributos de consistencia de los artículos revisados, se excluyeron los estudios con niveles IV y V de evidencia y los de calidad insuficiente. Las búsquedas acumuladas actuales sugieren la necesidad de ver a las diversas neoplasias desde la perspectiva de la dinámica de sistemas complejos y sus implicaciones evolutivas. El proceso evolutivo humano posee particularidades biosociales que le predisponen a sufrir tumores malignos. La postura bípeda incrementó vulnerabilidad al efecto oncogénico de las radiaciones ultravioletas. La conducta sexual incrementó el riesgo de contraer infecciones por virus oncogénicos. El paso a una predominantemente cárnica y la introducción de la cocción, se tradujo en la incorporación de agentes xenobióticos cuyo metabolismo deriva agentes carcinógenos. La postergación del envejecimiento humano devino en un mayor tiempo para el acúmulo de mutaciones. Las modificaciones en el patrón sexual y reproductivo en la mujer han influido en su predisposición al cáncer de mama. En la génesis poblacional del cáncer subyacen fundamentos biosociales vinculados al proceso evolutivo de la especie.

Facile synthesis of Ag dendrites on Al foil via galvanic replacement reaction with [Ag(NH{sub 3}){sub 2}]Cl for ultrasensitive SERS detecting of biomolecules

Energy Technology Data Exchange (ETDEWEB)

Fu, Jiajia; Ye, Weichun [Department of Chemistry, Lanzhou University, Lanzhou 73000 (China); Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou 73000 (China); Wang, Chunming, E-mail: wangcm@lzu.edu.cn [Department of Chemistry, Lanzhou University, Lanzhou 73000 (China); Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou 73000 (China)

2013-08-15

Symmetric silver dendrites have been synthesized on commercial aluminum foil via galvanic replacement reaction with [Ag(NH{sub 3}){sub 2}]Cl. This process is facile and environmentally friendly, without the use of any templates, surfactants or oxidants, and also avoiding the introduction of fluoride anions as a strong toxicity resulting in hypocalcemia. The products were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM) and X-ray diffraction (XRD). SEM characterizations and electrochemical measurements including an electrochemical direct current polarization method and OCP-t technique demonstrate that chloride has proven to be the key factor to the formation of well-defined dendritic shape. The as-prepared Ag dendrites are developed as a surface-enhanced Raman scattering (SERS)-active platform for detection of folic acid, DNA and RNA with well resolved bands and high Raman intensities. The detection concentration for the three biomolecules reaches the level of 10{sup −12} M, and thus the symmetric silver dendrites can potentially be employed as effective SERS sensors for label-free and ultrasensitive biomolecule detection. - Highlights: • Simple galvanic replacement is used to synthesize Ag dendrites on commercial Al foils. • This method avoids the introduction of fluoride anions. • The as-prepared dendrites exhibit high SERS activities for biomolecules. • The detection concentration for the biomolecules reaches the level of 10{sup −12} M.

Background information for the SER Energy Agreement for Sustainable Growth calculations. Sector Built Environment; Achtergronddocument bij doorrekening SER Energieakkoord. Sector Gebouwde omgeving

Energy Technology Data Exchange (ETDEWEB)

Menkveld, M.; Tigchelaar, C. [ECN Beleidsstudies, Petten (Netherlands)

2013-09-01

This publication is part of the support given by ECN and PBL in the development of a national energy agreement between March and September 2013 as initiated by the SER (Social and Economic Council of the Netherlands). The report gives background information on the evaluation of measures in the agreement aimed at the built environment. It is an annex of the general evaluation of PBL/ECN [Dutch] Dit rapport is geschreven als onderdeel van de ondersteuning door ECN en PBL bij het tot stand komen van het energieakkoord in de periode maart tot september 2013. Dit rapport dient als achtergrond bij de doorrekening van de maatregelen gericht op energiebesparing in de gebouwde omgeving.

Review on SERS of Bacteria

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Pamela A. Mosier-Boss

2017-11-01

Full Text Available Surface enhanced Raman spectroscopy (SERS has been widely used for chemical detection. Moreover, the inherent richness of the spectral data has made SERS attractive for use in detecting biological materials, including bacteria. This review discusses methods that have been used to obtain SERS spectra of bacteria. The kinds of SERS substrates employed to obtain SERS spectra are discussed as well as how bacteria interact with silver and gold nanoparticles. The roll of capping agents on Ag/Au NPs in obtaining SERS spectra is examined as well as the interpretation of the spectral data.

Comparison of ALS functionality and plant growth in ALS-inhibitor susceptible and resistant Myosoton aquaticum L.

Science.gov (United States)

Liu, Weitang; Bai, Shuang; Jia, Sisi; Guo, Wenlei; Zhang, Lele; Li, Wei; Wang, Jinxin

2017-10-01

Herbicide target-site resistance mutations may cause pleiotropic effects on plant ecology and physiology. The effect of several known (Pro197Ser, Pro197Leu Pro197Ala, and Pro197Glu) target-site resistance mutations of the ALS gene on both ALS functionality and plant vegetative growth of weed Myosoton aquaticum L. (water chickweed) have been investigated here. The enzyme kinetics of ALS from four purified water chickweed populations that each homozygous for the specific target-site resistance-endowing mutations were characterized and the effect of these mutations on plant growth was assessed via relative growth rate (RGR) analysis. Plants homozygous for Pro197Ser and Pro197Leu exhibited higher extractable ALS activity than susceptible (S) plants, while all ALS mutations with no negative change in ALS kinetics. The Pro197Leu mutation increased ALS sensitivity to isoleucine and valine, and Pro197Glu mutation slightly increased ALS sensitivity to isoleucine. RGR results indicated that none of these ALS resistance mutations impose negative pleiotropic effects on relative growth rate. However, resistant (R) seeds had a lowed germination rate than S seeds. This study provides baseline information on ALS functionality and plant growth characteristics associated with ALS inhibitor resistance-endowing mutations in water chickweed. Copyright © 2017. Published by Elsevier Inc.

Advanced Gas Sensors Using SERS-Activated Waveguides

Science.gov (United States)

Lascola, Robert; McWhorter, Scott; Murph, Simona Hunyadi

2010-08-01

This contribution describes progress towards the development and testing of a functionalized capillary that will provide detection of low-concentration gas-phase analytes through SERS. Measurement inside a waveguide allows interrogation of a large surface area, potentially overcoming the short distance dependence of the SERS effect. The possible use of Raman spectroscopy for gas detection is attractive for IR-inactive molecules or scenarios where infrared technology is inconvenient. However, the weakness of Raman scattering limits the use of the technique to situations where low detection limits are not required or large gas pressures are present. With surface-enhanced Raman spectroscopy (SERS), signal enhancements of 106 are often claimed, and higher values are seen in specific instances. However, most of the examples of SERS analysis are on liquid-phase samples, where the molecular density is high, usually combined with some sort of sample concentration at the surface. Neither of these factors is present in gas-phase samples. Because the laser is focused to a small point in the typical experimental setup, and the spatial extent of the effect above the surface is small (microns), the excitation volume is miniscule. Thus, exceptionally large enhancements are required to generate a signal comparable to that obtained by conventional Raman measurements. A reflective waveguide offers a way to increase the interaction volume of the laser with a SERS-modified surface. The use of a waveguide to enhance classical Raman measurements was recently demonstrated by S.M. Angel and coworkers, who obtained 12- to 30-fold sensitivity improvements for nonabsorbing gases (CO2, CH4) with a silvered capillary (no SERS enhancement). Shi et al.. demonstrated 10-to 100-fold enhancement of aqueous Rhodamine 6G in a capillary coated with silver nanoparticles. They observed enhancements of 10- to 100-fold compared to direct sampling, but this relied on a "double substrate", which required

LA ELOCUENCIA, SISTEMA DE VIDA ÍNSITO EN EL SER HUMANO

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Bulmaro Reyes Coria

2013-01-01

Full Text Available Resumen Este artículo se funda en el repaso directo de las preceptivas retóricas aristotélica y ciceroniana, incluida la Retórica a Herenio. Pretende mostrar que la elocuencia, o retórica, no es una simple asignatura escolar que se desliga de la esencia del ser humano, sino un sistema que le es inherente a este. Tal sistema es capaz de ser cultivado y fortalecido por el estudio o la ejercitación, y estas dos tareas constituyen el lugar donde se nutre la invención: ahí se hace evidente la materia prima de los entimemas, ahí el ser humano cobra consciencia de que ese otro sistema es parte de su integridad, a pesar de que le sea intangible al tacto, como lo era para Sancho, quien, sin embargo, no podía vivir sin hablar ni siquiera contra los mandatos del amo.

Surface modification of nanoporous alumina layers by deposition of Ag nanoparticles. Effect of alumina pore diameter on the morphology of silver deposit and its influence on SERS activity

Science.gov (United States)

Pisarek, Marcin; Nowakowski, Robert; Kudelski, Andrzej; Holdynski, Marcin; Roguska, Agata; Janik-Czachor, Maria; Kurowska-Tabor, Elżbieta; Sulka, Grzegorz D.

2015-12-01

Self-organized Al2O3 nanoporous/nanotubular (Al2O3-NP) oxide layers decorated with silver nanoparticles (Ag-NPs) exhibiting specific properties may serve as attractive SERS substrates for investigating the interactions between an adsorbate and adsorbent, or as stable platforms for detecting various organic compounds. This article presents the influence of the size of the alumina nanopores with a deposit of silver nanoparticles obtained by the magnetron sputtering technique on the morphology of silver film. Moreover, the effect of pore diameter on the intensity of SERS spectra in Ag-NPs/Al2O3-NP/Al composites has also been estimated. For such investigations we used pyridine as a probe molecule, since it has a large cross-section for Raman scattering. To characterize the morphology of the composite oxide layer Ag-NPs/Al2O3-NP/Al, before and after deposition of Ag-NPs by PVD methods (Physical Vapor Deposition), we used scanning electron microscopy (SEM) and atomic force microscopy (AFM). The surface analytical technique of surface-enhanced Raman spectroscopy (SERS) was used to investigate the surface activity of the composite. The results obtained show that, for a carefully controlled amount of Ag (0.020 mg/cm2 - deposited on the top of alumina nanopores whose average size varies from ∼86 nm up to ∼320 nm) in the composites investigated, pore size significantly affects SERS enhancement. We obtained distinctly higher intensities of SERS spectra for substrates with an Ag-NPs deposit having a larger diameter of the alumina nanopores. AFM results suggest that both the lateral and perpendicular distribution of Ag-NPs within and on the top of the largest pores is responsible for the highest SERS activity of the resulting Ag-NPs/Al2O3-NP/Al composite layer, since it produces a variety of cavities and slits which function as resonators for the adsorbed molecules. The Ag-NPs/MeOx-NP/Me composite layers obtained ensure a good reproducibility of the SERS measurements.

Eficacia de plaguicidas sobre larvas de Capnodis tenebrionis (L.)

OpenAIRE

Sanna Passino, G.; Delrio, Gavino

2001-01-01

Se determina la eficacia de algunos plaguicidas sobre larvas recién nacidas de Capnodis tenebrionis (L.) en ensayos de laboratorio. Se utilisaron algunos productos comerciales que contenían isofenfos+foxim, clorpirifos, diazinon y carbaril. Las formulaciones más tóxicas eran las que contenían clorpirifos y isofenfos+foxim que causaron una mortandad media de 83.3 y 76.2% respectivamente. El análisis de los datos reveló que el efecto residual tenía una influencia significativa en mortandad de l...

Myofilament Calcium Sensitivity: Mechanistic Insight into TnI Ser-23/24 and Ser-150 Phosphorylation Integration

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Hussam E Salhi

2016-12-01

Full Text Available Troponin I (TnI is a major regulator of cardiac muscle contraction and relaxation. During physiological and pathological stress, TnI is differentially phosphorylated at multiple residues through different signaling pathways to match cardiac function to demand. The combination of these TnI phosphorylations can exhibit an expected or unexpected functional integration, whereby the function of two phosphorylations are different than that predicted from the combined function of each individual phosphorylation alone. We have shown that TnI Ser-23/24 and Ser-150 phosphorylation exhibit functional integration and are simultaneously increased in response to cardiac stress. In the current study, we investigated the functional integration of TnI Ser-23/24 and Ser-150 to alter cardiac contraction. We hypothesized that Ser-23/24 and Ser-150 phosphorylation each utilize distinct molecular mechanisms to alter the TnI binding affinity within the thin filament. Mathematical modeling predicts that Ser-23/24 and Ser-150 phosphorylation affect different TnI affinities within the thin filament to distinctly alter the Ca2+-binding properties of troponin. Protein binding experiments validate this assertion by demonstrating pseudo-phosphorylated Ser-150 decreases the affinity of isolated TnI for actin, whereas Ser-23/24 pseudo-phosphorylation is not different from unphosphorylated. Thus, our data supports that TnI Ser-23/24 affects TnI-TnC binding, while Ser-150 phosphorylation alters TnI-actin binding. By measuring force development in troponin-exchanged skinned myocytes, we demonstrate that the Ca2+ sensitivity of force is directly related to the amount of phosphate present on TnI. Furthermore, we demonstrate that Ser-150 pseudo-phosphorylation blunts Ser-23/24-mediated decreased Ca2+-sensitive force development whether on the same or different TnI molecule. Therefore, TnI phosphorylations can integrate across troponins along the myofilament. These data demonstrate

Synergistic effects of semiconductor substrate and noble metal nano-particles on SERS effect both theoretical and experimental aspects

Science.gov (United States)

Yang, Chen; Liang, Pei; Tang, Lisha; Zhou, Yongfeng; Cao, Yanting; Wu, Yanxiong; Zhang, De; Dong, Qianmin; Huang, Jie; He, Peng

2018-04-01

As a means of chemical identification and analysis, Surface enhanced Raman spectroscopy (SERS), with the advantages of high sensitivity and selectivity, non-destructive, high repeatability and in situ detection etc., has important significance in the field of composition detection, environmental science, biological medicine etc. Physical model of coupling effect between different semiconductor substrates and noble metal particles were investigated by using 3D-FDTD method. Mechanism and the effects of excitation wavelength, particle spacing and semiconductor substrate types on the SERS effect were discussed. The results showed that the optimal excitation wavelengths of three noble metals of Ag, Au, Cu, were located at 510, 600 and 630 nm, respectively; SERS effect of Ag, Au, Cu increases with the decreasing of the inter distance of particles, while the distance of the NPs reaches the critical value of 3 nm, the strength of SERS effect will be greatly enhanced. For the four different types of substrate of Ge, Si, SiO2 (glass) and Al2O3, the SERS effect of Ag on SiO2 > Ge > Al2O3 > Si. For Au and Cu nanoparticles, the SERS effect of them on oxide substrate is stronger than that on non-oxide substrate. In order to verify FDTD simulations, taking silver nanoparticles as an example, and silver nanoparticles prepared by chemical method were spinning coating on the four different substrates with R6G as probe molecules. The results show that the experimental results are consistent with FDTD theoretical simulations, and the SERS enhancement effect of Ag-SiO2 substrate is best. The results of this study have important theoretical significance to explain the variations of SERS enhancement on different noble metals, which is also an important guide for the preparation of SERS substrates, especially for the microfluidics. The better Raman effect can be realized by choosing proper substrate type, particle spacing and excitation wavelength, result in expanding the depth and width

Emergindo a complexidade do cuidado de enfermagem ao ser em morte encefálica Complejidad emergente del cuidado de enfermería al paciente con muerte cerebral Emerging the complexity of nursing care facing a brain death

Directory of Open Access Journals (Sweden)

Aline Lima Pestana

2012-12-01

Full Text Available O estudo objetivou desvelar a complexidade do cuidado de enfermagem ao ser em morte encefálica. Utilizaram-se como referenciais teórico e metodológico o pensamento complexo e a Grounded Theory, respectivamente. Os dados foram coletados em um hospital universitário do nordeste brasileiro, de dezembro de 2010 a junho de 2011, por meio de entrevistas não estruturadas. A amostra teórica constituiu-se de 12 enfermeiros, distribuídos em três grupos amostrais. O fenômeno "Desvelando relações e interações múltiplas do ser enfermeiro na complexidade do cuidado ao ser em morte encefálica" foi delimitado por cinco categorias. Neste artigo, foi abordada a categoria "Emergindo a complexidade do cuidado de enfermagem ao ser em morte encefálica". O estudo evidenciou que o cuidado ao ser em morte encefálica é caracterizado por desordem e incertezas, fazendo com que o enfermeiro vivencie sentimentos diversos e ambivalentes. A sua complexidade está em compreender a sua singularidade e dialogicidade.Este estudio objetivó desvelar la complejidad del cuidado en enfermería al paciente con muerte encefálica. Se utilizaron como marcos teórico y metodológico el pensamiento complejo y la Grounded Theory, respectivamente. Los datos fueron recolectados en un hospital universitario en el nordeste de Brasil, entre diciembre de 2010 y junio de 2011, a través de entrevistas no estructuradas. La muestra teórica fue compuesta por 12 enfermeras asignadas en tres grupos. El fenómeno "Revelando las múltiples relaciones e interacciones en ser un enfermero en la complejidad del cuidado del paciente con muerte cerebral" fue delimitada en cinco categorías. En este artículo, se dirigió a la categoría de "Emergiendo la complejidad del cuidado de enfermería al paciente en muerte cerebral". El estudio mostró que el cuidado al ser en muerte cerebral se acompaña de desorden e incertidumbres, haciendo con que la enfermera pueda experimentar diferentes y

Toward practical SERS sensing

Science.gov (United States)

Zhao, Yiping

2012-06-01

Since its discovery more than 30 years ago, surface-enhanced Raman scattering (SERS) has been recognized as a highly sensitive detection technique for chemical and biological sensing and medical diagnostics. However, the practical application of this remarkably sensitive technique has not been widely accepted as a viable diagnostic method due to the difficulty in preparing robust and reproducible substrates that provide maximum SERS enhancement. Here, we demonstrate that the aligned silver nanorod (AgNR) array substrates engineered by the oblique angle deposition method are capable of providing extremely high SERS enhancement factors (>108). The substrates are large area, uniform, reproducible, and compatible with general microfabrication process. The enhancement factor depends strongly on the length and shape of the Ag nanorods and the underlying substrate coating. By optimizing AgNR SERS substrates, we show that SERS is able to detect trace amount of toxins, virus, bacteria, or other chemical and biological molecules, and distinguish different viruses/bacteria and virus/bacteria strains. The substrate can be tailored into a multi-well chip for high throughput screening, integrated into fiber tip for portable sensing, incorporated into fluid/microfluidic devices for in situ real-time monitoring, fabricated onto a flexible substrate for tracking and identification, or used as on-chip separation device for ultra-thin layer chromatography and diagnostics. By combining the unique SERS substrates with a handheld Raman system, it can become a practical and portable sensor system for field applications. All these developments have demonstrated that AgNR SERS substrates could play an important role in the future for practical clinical, industrial, defense, and security sensing applications.

Morpho-toxicology of chlorpyrifos to prolactin cells of a freshwater catfish, Heteropneustes fossilis =Morpho-toxicology of chlorpyrifos to prolactin cells of a freshwater catfish, Heteropneustes fossilis

Directory of Open Access Journals (Sweden)

Diwakar Mishra

2012-10-01

Full Text Available In the present study, an organophosphorus compound Coroban (active ingredient chlorpyrifos – E.C. 20% was used. In short-term exposure the fish were subjected to 0.8 of 96h LC50 value of chlorpyrifos (1.76 mg L-1 for 96h. In long-term exposure the experiment was performed for 28 days by using 0.2 of 96h LC50 value of chlorpyrifos (0.44 mg L-1. Fish were killed on each time intervals from control and experimental (chlorpyrifos groups after 24, 48, 72, and 96h in short-term exposure and after 7, 14, 21, and 28 days in long-term experiment. Blood samples were collected and sera were analyzed for calcium. Pituitary glands were fixed for histological studies and stained with Herlant tetrachrome and Heidenhain’s azan techniques. Short-term exposure of chlorpyrifos caused decrease in the serum calcium levels. No change was noticed in the prolactin cells of chlorpyrifos treated fish. Long-term treatment with chlorpyrifos provoked hypocalcemia. The prolactin cells of treated fish exhibited slight degranulation after 21 days whereas the nuclear volume remained unchanged. After 28 days, the prolactin cells exhibited further degranulation and the nuclear volume recorded an increase. Cytolysis and vacuolization were also visible. No estudo presente, o composto organofosforo Coroban (ingrediente ativo clorpirifo – E.C. 20% foi usado. Na exposição a curto prazo os peixes foram submetido a 0,8 de valor LC50 de 96h de clorpirifo (1,76 mg L-1 durante 96h. Na exposição a longo prazo o experimento foi executado durante 28 dias usando 0,2 de valor LC50 de 96h de clorpirifos (0,44 mg L-1. Os peixes foram mortos a cada intervalo dos grupos controle e experimental (clorpirifos após 24, 48, 72, e 96h em exposição a curto prazo e após 7, 14, 21, e 28 dias no experimento a longo prazo. As amostras de sangue foram colhidas e o soro foi analisado para cálcio. As glândulas pituitárias foram fixadas para estudos histológicos e colorido por tetracromo de

Criatividade em ação: ser criativo é ser criança

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Antonio Mendes Silva Filho

2012-11-01

Full Text Available Todo ser humano é criativo e isso decorre da capacidade de imaginação. Essa capacidade é acentuada quando você tem a possibilidade de explorar e a curiosidade aguçada. Não exemplo melhor do que uma criança. Ser criativo é ser criança. Esta capacidade alcança o ápice quando se busca criar como criança fazendo uso de sagacidade, persistência, desorganização e com a possibilidade de errar. Isso é explorar e experimentar, deixando o cérebro livre e sem pressão, agindo despreocupadamente em determinado período de tempo. Nesse sentido, este artigo explora a importancia dar oportunidade do ser humano explorar sua capacidade de criar via imaginação

Láser en ortodoncia

OpenAIRE

Ruíz-Esculpi, María; Ricse-Chaupis, Estela; Villanueva-Vega, Judith; Torres-Maita, Liz

2014-01-01

La primera aplicación del láser en un diente fue realizada en 1965. Desde entonces ha presentado una constante evolución y desarrollo. La tecnología láser permite realizar procedimientos en tejidos duros y blandos, pudiendo ser utilizado con las siguientes finalidades: como prevención de la desmineralización, en la adhesión y remoción de brackets, en la reducción del dolor producto del movimiento dental, en la reparación ósea después de la expansión, en diversas cirugías y otras aplicaciones ...

SERS detection of biomolecules using lithographed nanoparticles towards a reproducible SERS biosensor

Energy Technology Data Exchange (ETDEWEB)

David, Catalina; Guillot, Nicolas; Chapelle, Marc Lamy de la [Laboratoire CSPBAT (FRE 3043), UFR SMBH, Universite Paris XIII, 74 rue Marcel Cachin, F-93017 Bobigny (France); Shen, Hong; Toury, Timothee, E-mail: marc.lamydelachapelle@univ-paris13.fr [ICD-LNIO-UMR, CNRS 6279, Universite de technologie de Troyes, 12 rue Marie Curie, F-10010 Troyes (France)

2010-11-26

In this paper we highlight the accurate spectral detection of bovine serum albumin and ribonuclease-A using a surface-enhanced Raman scattering (SERS) substrate based on gold nanocylinders obtained by electron-beam lithography (EBL). The nanocylinders have diameters from 100 to 180 nm with a gap of 200 nm. We demonstrate that optimizing the size and the shape of the lithographed gold nanocylinders, we can obtain SERS spectra of proteins at low concentration. This SERS study enabled us to estimate high enhancement factors (10{sup 5} for BSA and 10{sup 7} for RNase-A) of important bands in the protein Raman spectrum measured for 1 mM concentration. We demonstrate that, to reach the highest enhancement, it is necessary to optimize the SERS signal and that the main parameter of optimization is the LSPR position. The LSPR have to be suitably located between the laser excitation wavelength, which is 632.8 nm, and the position of the considered Raman band. Our study underlines the efficiency of gold nanocylinder arrays in the spectral detection of proteins.

Caída abrupta del tono muscular al entrar a sueño MOR en el ser humano

OpenAIRE

Rosales-Lagarde, Alejandra; del Río-Portilla, Irma Yolanda; Guevara, Miguel Ángel; Corsi-Cabrera, María

2009-01-01

De acuerdo con el manual estandarizado para la clasificación del sueño en el ser humano, tres variables fisiológicas marcan el inicio del sueño con movimientos oculares rápidos (MOR): la desincronización electroencefalográfica (EEG), los movimientos oculares rápidos y la pérdida de tono muscular. De estos tres indicadores, uno de ellos, los movimientos oculares rápidos, es una manifestación intermitente o fásica que consiste en movimientos que pueden ser aislados o emitirse en salvas de vario...

Microfluidic setup for on-line SERS monitoring using laser induced nanoparticle spots as SERS active substrate

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Oana-M. Buja

2017-01-01

Full Text Available A microfluidic setup which enables on-line monitoring of residues of malachite green (MG using surface-enhanced Raman scattering (SERS is reported. The SERS active substrate was prepared via laser induced synthesis of silver or gold nanoparticles spot on the bottom of a 200 μm inner dimension glass capillary, by focusing the laser beam during a continuous flow of a mixture of silver nitrate or gold chloride and sodium citrate. The described microfluidic setup enables within a few minutes the monitoring of several processes: the synthesis of the SERS active spot, MG adsorption to the metal surface, detection of the analyte when saturation of the SERS signal is reached, and finally, the desorption of MG from the spot. Moreover, after MG complete desorption, the regeneration of the SERS active spot was achieved. The detection of MG was possible down to 10−7 M concentration with a good reproducibility when using silver or gold spots as SERS substrate.

La inconstitucionalidad de algunas restricciones al derecho a ser elegido en Colombia

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Juan Fernando Reyes Kuri

2009-12-01

Full Text Available Este artículo cuestiona la facultad normativa que existe en Colombia para restringir el derecho a ser elegido por razones distintas de las contenidas en los tratados internacionales que hacen parte del bloque de constitucionalidad y que, es claro, deben primar en el orden interno. El Código Único Disciplinario (Ley 734 de 2002, por ejemplo, permite que mediante un proceso de carácter administrativo, distinto del penal, se limiten duramente los derechos políticos fundamentales de los ciudadanos, a pesar de lo establecido en el artículo 23 de la Convención Americana sobre Derechos Humanos referente a esta clase de derechos. Sin embargo, la Corte Constitucional insiste en la constitucionalidad de las referidas normas que a todas luces resultan violatorias de nuestra Constitución.

O sentido do ser-mãe-que-tem-a-possibilidade-de-tocar-o-filho-prematuro na unidade intensiva: contribuições para a enfermagem neonatal El significado de ser la madre-que-tiene-la-posibilidad-de-tocar-al-hijo-prematuro en la unidad de cuidados intensivos: contribuciones para la enfermería neonatal The meaning of being the mother-that-has-the-possibility-to-touch-the-premature-baby in the intensive unit: contributions for the neonatal nursing

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Rita de Cássia de Jesus Melo

2012-06-01

Full Text Available Estudo na abordagem teórico-metodológica heideggeriana com o objetivo de desvelar o sentido do ser-mãe que tem a possibilidade de tocar o filho prematuro na UTIN. Após aprovação foi desenvolvida entrevista fenomenológica com nove mulheres-mães. A análise compreensiva constituiu oito unidades de significação, e a hermenêutica permitiu desvelar o movimento existencial do sermãe em sua cotidianidade, nos modos de ser da inautenticidade e impessoalidade, movida pelo falatório, ambiguidade e temor, modos de ocupação. Ao compreender como sua a possibilidade de ter um filho prematuro, toca-o cautelosamente e cuidadosamente, transita para um entendimento no qual não mais se ocupa, se preo-cupa. Ao pre-ocupar, o ser-mãe estabelece a possibilidade de ser-aí-com-o-filho. Foi possível entender este modo de ser mãe, no qual passa por estágios antes de ver o bebê como seu e confiar em si. Possibilitar que toque seu filho, compreendendo-a em sua individualidade, singularidade, mostrou-se como um cuidado ao RNP em sua complexidade como ser-aí.Estudio en el enfoque teórico-metodológico heideggeriana con el objetivo de revelar el sentido del ser la madre que tiene la possibilidad de tocar el hijo prematuro en una Unidad de Cuidados Intensivos Neonatal. Después de la aprobación, fue desarrollada una entrevista fenomenológica con nueve madres. El análisis comprehensivo constituyó ocho unidades de significación, la hermenéutica permitió revelar el movimiento existencial del ser madre en su cotidianidad, en los modos de ser de la falta de autenticidad e impersonalidad, movida por el chisme, la ambigüedad y miedo, modos de ocupación. Al comprender como de ella la posibilidad de tener un bebé prematuro, lo toca con cautela y cuidado, transita para un entendimiento en el cual no más se ocupa, se preocupa. Al preocuparse, el ser madre establece la posibilidad de ser-ahí-con-el-hijo. Fue posible entender este modo de ser madre, que

Stabilization of alanine substituted p53 protein at Ser15, Thr18, and Ser20 in response to ionizing radiation

International Nuclear Information System (INIS)

Yamauchi, Motohiro; Suzuki, Keiji; Kodama, Seiji; Watanabe, Masami

2004-01-01

Phosphorylation of p53 at Ser15, Thr18, and Ser20 has been thought to be important for p53 stabilization in response to ionizing radiation. In the present study, we examined the X-ray-induced stabilization of Ala-substituted p53 protein at Ser15, Thr18, and Ser20, whose gene expression was controlled under an ecdyson-inducible promoter. We found that all single-, double-, or triple-Ala-substituted p53 at Ser15, Yhr18, and Ser20 were accumulated in the nucleus similarly to wild-type p53 after X-irradiation. These results indicate that the phosphorylation of p53 at Ser15, Thr18, and Ser20 is not necessarily needed for p53 stabilization in response to ionizing radiation

Bello et al (9)

African Journals Online (AJOL)

Timade VENTURE

family Solanaceae and it is one of the largest and ... al.,2004). The taxonomy of this important genus is of ... importance of numerical taxonomic method in ..... SME. SAE. SAM. SNI. SER. SWR. SMA. SGI. -6.4. -4.8. -3.2. -1.6. 0. 1.6. 3.2. 4.8.

SERS-Active Nanoinjector for Intracellular Spectroscopy

Science.gov (United States)

Vitol, Elina; Orynbayeva, Zulfiya; Bouchard, Michael; Azizkhan-Clifford, Jane; Friedman, Gary; Gogotsi, Yury

2009-03-01

We developed a multifunctional nanopipette which allows simultaneous cell injection and intacellular surface-enhanced Raman spectroscopy (SERS) analysis. SERS spectra contain the characteristic frequencies of molecular bond vibrations. This is a unique method for studying cell biochemistry and physiology on a single organelle level. Unlike the fluorescence spectroscopy, it does not require any specific staining. The principle of SERS is based on very large electromagnetic field enhancement localized around a nano-rough metallic surface. Gold colloids are widely used SERS substrates. Previously, the colloidal nanoparticles were introduced into a cell by the mechanism of endocytosis. The disadvantage of this method is the uncontrollable aggregation and distribution of gold nanoparticles inside a cell which causes a significant uncertainty in the origin of the acquired data. At the same time, the nanoparticle uptake is irreversible. We present a SERS-active nanoinjector, coated with gold nanoparticles, which enables selective signal acquisition from any point-of-interest inside a cell. The nanoinjector provides a highly localized SERS signal with sub-nanometer resolution in real time.

Leucipo, Demócrito e Kant: uma Reflexão sobre a Equivalência entre Ser e Não-Ser

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Eberth Eleuterio dos Santos

2015-08-01

Full Text Available De início, apresentaremos a tese de Demócrito e Leucipo, segundo a qual o ser não é mais que o não-ser, tendo como contraponto o pensamento eleata acerca da inexistência necessária do não-ser. Esta discussão nos remete à oposição entre o pleno (cheio e o vazio que será posteriormente traduzida na oposição entre o ser e o nada (ou o não-ser. Desse modo, a oposição entre o pleno e o vazio é uma oposição que se desloca para o ser e o não-ser. Em seguida, faremos a apreciação do escrito pré-crítico kantiano Ensaio para introduzir em filosofia o conceito de grandeza negativa, no qual distinguimos certo tipo de oposição tomada entre grandezas em geral que, acreditamos, poderia ser interpretado como estando de acordo com o posicionamento de Demócrito e Leucipo sobre o estatuto ontológico do não-ser como princípio equivalente ao ser, e não como sua contradição em sentido puramente lógico.

O ser criança: percepção de alunas de um curso de graduação em enfermagem El ser niño: percepción de alumnas de un curso de pregrado de enfermería Perception of children by nursing undergraduate students

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Maria Aparecida Munhoz Gaíva

1999-01-01

Full Text Available As autoras tiveram como objetivo conhecer a percepção sobre criança, de alunas do 4º semestre de graduação em enfermagem de uma Universidade Pública Brasileira. Para tanto solicitaram às alunas que escrevessem acerca de sua percepção sobre crianças, no primeiro e último dias de atividades acadêmicas na disciplina de Enfermagem Pediátrica. Utilizando a abordagem qualitativa, analisaram os relatos, identificando os seguintes núcleos temáticos: "ser pequeno, frágil e inocente", "ser humano cidadão", "ser humano em fase de desenvolvimento", "ser que se diverte", "O ambiente e a formação da criança" e a "interação da criança com o adulto". Os resultados mostram que, inicialmente, as alunas percebiam a criança como ser frágil, imaturo e despreparado para enfrentar a vida, necessitando da proteção do adulto. Ao final da disciplina passam a ver a criança como um ser em fase de desenvolvimento, como cidadão e com os mesmos direitos do adulto.Las autoras tuvieron como objetivo conocer la percepción sobre el ser niño, que tienen las alumnas del cuarto semestre de pregrado en enfermería de una Universidad Pública Brasileña. Para esto solicitaron a las alumnas que escribieran acerca de su percepción sobre el niño, en el primero y último día de actividades académicas de la disciplina de enfermería pediatrica. Utilizando un abordaje cualitativo, analizaron los relatos, identificando los siguientes núcleos temáticos: "ser pequeño, frágil e inocente", "ser humano ciudadano", "ser humano en fase de desarrollo", "ser que se divierte", "El ambiente y la formación del niño" y la "interacción del niño con el adulto". Los resultados muestran que inicialmente las alumnas percibían al niño como ser frágil, inmaduro y no preparado para enfrentar la vida, necesitando de la protección del adulto. Al final de la disciplina pasan a ver al niño, como un ser en fase de desarollo, como ciudadano y con los mismos derechos del

Necesidad de la creación de una sanción penal especial para ser impuesta al sujeto que padece trastorno antisocial de la personalidad (psicopatía en Colombia

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María Margarita Tirado-Álvarez

2010-06-01

Full Text Available El propósito del artículo se centra en analizar la necesidad que hay o no de crear una sanción especial para el sujeto con psicopatía, teniendo en cuenta sus particulares características (incurable, ausencia de remordimiento, ausencia de temor al castigo, alto nivel de reincidencia, cosificación del ser humano, y la naturaleza de las sanciones contenidas en la ley penal nacional, en defensa de la justicia, el respeto por los derechos humanos de víctima y victimario, la seguridad de la sociedad y la adecuada punición.

Stamping SERS for creatinine sensing

Science.gov (United States)

Li, Ming; Du, Yong; Zhao, Fusheng; Zeng, Jianbo; Santos, Greggy M.; Mohan, Chandra; Shih, Wei-Chuan

2015-03-01

Urine can be obtained easily, readily and non-invasively. The analysis of urine can provide metabolic information of the body and the condition of renal function. Creatinine is one of the major components of human urine associated with muscle metabolism. Since the content of creatinine excreted into urine is relatively constant, it is used as an internal standard to normalize water variations. Moreover, the detection of creatinine concentration in urine is important for the renal clearance test, which can monitor the filtration function of kidney and health status. In more details, kidney failure can be imminent when the creatinine concentration in urine is high. A simple device and protocol for creatinine sensing in urine samples can be valuable for point-of-care applications. We reported quantitative analysis of creatinine in urine samples by using stamping surface enhanced Raman scattering (S-SERS) technique with nanoporous gold disk (NPGD) based SERS substrate. S-SERS technique enables label-free and multiplexed molecular sensing under dry condition, while NPGD provides a robust, controllable, and high-sensitivity SERS substrate. The performance of S-SERS with NGPDs is evaluated by the detection and quantification of pure creatinine and creatinine in artificial urine within physiologically relevant concentration ranges.

Láser escáner y nubes de puntos. Un horizonte aplicado al análisis arqueológico de edificios

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García-Gómez, Ismael

2011-12-01

Full Text Available This paper analyses the laser scanner, a powerful tool for graphic recording of cultural heritage sites. Although attention will be drawn to those technical and logistical aspects and methods related to its employment, this report will mainly focus on its applicability on Building Archaeology, highlighting those diagnosing capacities which may help the stratigrapher to establish an evolutionary sequence of the building. The basis of this study is our work on San Miguel church in Vitoria-Gasteiz.En el siguiente artículo analizamos uno de los más modernos instrumentos de documentación gráfica del patrimonio, el láser escáner. Aunque profundizaremos en todos aquellos aspectos técnicos, logísticos y de método relativos a su empleo, nos centraremos en su efectiva aplicabilidad dentro del campo de la Arqueología de la Arquitectura, incidiendo en aquellas capacidades diagnósticas que pueden ayudar al estratígrafo a determinar la secuencia evolutiva de un edificio. Tomaremos como base nuestra experiencia en la iglesia de San Miguel de Vitoria-Gasteiz.

Engineering Metal Nanostructure for SERS Application

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Yanqin Cao

2013-01-01

Full Text Available Surface-enhanced Raman scattering (SERS has attracted great attention due to its remarkable enhancement and excellent selectivity in the detection of various molecules. Noble metal nanomaterials have usually been employed for producing substrates that can be used in SERS because of their unique local plasma resonance. As the SERS enhancement of signals depends on parameters such as size, shape, morphology, arrangement, and dielectric environment of the nanostructure, there have been a number of studies on tunable nanofabrication and synthesis of noble metals. In this work, we will illustrate progress in engineering metallic nanostructures with various morphologies using versatile methods. We also discuss their SERS applications in different fields and the challenges.

Fasting mediated increase in p-BAD(ser155) and p-AKT(ser473) in the prefrontal cortex of mice.

Science.gov (United States)

Pitchaimani, Vigneshwaran; Arumugam, Somasundaram; Thandavarayan, Rajarajan Amirthalingam; Karuppagounder, Vengadeshprabhu; Sreedhar, Remya; Afrin, Rejina; Harima, Meilei; Suzuki, Hiroshi; Miyashita, Shizuka; Nomoto, Mayumi; Sone, Hirohito; Suzuki, Kenji; Watanabe, Kenichi

2014-09-05

BAD-deficient mice and fasting have several common functional roles in seizures, beta-hydroxybutyrate (BHB) uptake in brain and alteration in counterregulatory hormonal regulation during hypoglycemia. Neuronal specific insulin receptor knockout (NIRKO) mice display impaired counterregulatory hormonal responses during hypoglycemia. In this study we investigated the fasting mediated expression of p-BAD(ser155) and p-AKT(ser473) in different regions of brain (prefrontal cortex, hippocampus, midbrain and hypothalamus). Fasting specifically increases p-BAD(ser155) and p-AKT(ser473) in prefrontal cortex and decreases in other regions of brain. Our results suggest that fasting may increase the uptake BHB by decreasing p-BAD(ser155) in the brain during hypoglycemia except prefrontal cortex and it uncovers specific functional area of p-BAD(ser155) and p-AKT(ser473) that may regulates counter regulatory hormonal response. Overall in support with previous findings, fasting mediated hypoglycemia activates prefrontal cortex insulin signaling which influences the hypothalamic paraventricular nucleus mediated activation of sympathoadrenal hormonal responses. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Batch fabrication of disposable screen printed SERS arrays.

Science.gov (United States)

Qu, Lu-Lu; Li, Da-Wei; Xue, Jin-Qun; Zhai, Wen-Lei; Fossey, John S; Long, Yi-Tao

2012-03-07

A novel facile method of fabricating disposable and highly reproducible surface-enhanced Raman spectroscopy (SERS) arrays using screen printing was explored. The screen printing ink containing silver nanoparticles was prepared and printed on supporting materials by a screen printing process to fabricate SERS arrays (6 × 10 printed spots) in large batches. The fabrication conditions, SERS performance and application of these arrays were systematically investigated, and a detection limit of 1.6 × 10(-13) M for rhodamine 6G could be achieved. Moreover, the screen printed SERS arrays exhibited high reproducibility and stability, the spot-to-spot SERS signals showed that the intensity variation was less than 10% and SERS performance could be maintained over 12 weeks. Portable high-throughput analysis of biological samples was accomplished using these disposable screen printed SERS arrays.

Achieving optimal SERS through enhanced experimental design.

Science.gov (United States)

Fisk, Heidi; Westley, Chloe; Turner, Nicholas J; Goodacre, Royston

2016-01-01

One of the current limitations surrounding surface-enhanced Raman scattering (SERS) is the perceived lack of reproducibility. SERS is indeed challenging, and for analyte detection, it is vital that the analyte interacts with the metal surface. However, as this is analyte dependent, there is not a single set of SERS conditions that are universal. This means that experimental optimisation for optimum SERS response is vital. Most researchers optimise one factor at a time, where a single parameter is altered first before going onto optimise the next. This is a very inefficient way of searching the experimental landscape. In this review, we explore the use of more powerful multivariate approaches to SERS experimental optimisation based on design of experiments and evolutionary computational methods. We particularly focus on colloidal-based SERS rather than thin film preparations as a result of their popularity. © 2015 The Authors. Journal of Raman Spectroscopy published by John Wiley & Sons, Ltd.

Llegar a ser Simone de Beauvoir

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Nora Levinton Dolman

2009-01-01

Full Text Available A la manera de un Psicoanálisis aplicado a la obra de Simone de Beauvoir se señalan algunos aspectos cruciales que reflejan cómo se va configurando la vida y el pensamiento de una mujer que encarnó, para muchas de nosotras, un modelo de identificación. Su trabajo es en este sentido un espejo y una valiosa muestra de la naturaleza proyectiva de muchos de sus enunciados, donde a partir de su irreemplazable experiencia Simone arriba a conclusiones en las que podemos seguir el rastro de sus vivencias personales. En el contexto singular de su historia personal y en cómo es relatada. Al exponer su vida en sus libros y en numerosas entrevistas concedidas a distintos medios, ha dado lugar a que surgieran diferentes interpretaciones, por lo tanto a que sus palabras y argumentos puedan, como en este artículo, ser utilizados, contrastados entre sí y sometidos a exploración.

Comentarios al Salto Social

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Facultad de Ciencias Económicas

1995-06-01

Full Text Available 1. El Plan considera que la política social es un componente central de la estrategia macroeconómica. A diferencia de la administración Gaviria, lo social ha dejado de ser un asunto marginal, es consustancial al desarrollo y, por tanto, se le confiere una dimensión cualitativamente diferente.

¿PERMITE SER FELIZ LA MORAL CRISTIANA?

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Waldo Romo P

2006-01-01

Full Text Available La pregunta que encabeza el artículo ya es desafiante: "¿Permite ser feliz la moral cristiana?". Existe la posibilidad de responder negativamente. El autor, después de analizar algunos pensadores (Nietzsche, entre ellos que han negado a la moral cristiana la posibilidad de hacer feliz al ser humano, presenta las condiciones de posibilidad para que dicha moral se encauce a ser un camino de felicidad. Entre esas condiciones se destaca: el paso de una moral heterónama a una moral de autonomía teónoma, una moral centrada en la persona más que una moral centrada en la ley, una moral de discipulado que pone primero el amor y luego el cumplimiento normativo. Profundiza, al respecto, en el logion de Jesucristo: "El que me ama, cumple mis mandamientos". Esta enseñanza plantea el orden secuencial de toda moral cristiana: porque se ama a Jesús, se entiende el cumplimiento de las normas. Estas se transforman, entonces, en el "test" verificador del amor. De lo contrario, se permanece en un ritualismo normativo, que en defintiva hastía y no lleva a la felicidad. Por ello, el artículo profundiza en una moral de opción fundamental expresada en actitudes y actos morales coherentes con esa opción. Si las condiciones de posibilidad propuestas se llegan a dar, la interrogante que organiza el artículo tendrá una respuesta positivaThe question that heads this article is already challenging: "Does Christian morality permit one to be happy?" The possibility of responding negatively exists. The author, after analyzing the contributions of some thinkers (Nietszche among them who have denied the possibility that Christian morality could make human beings happy, presents the conditions that would orient said morality towards the possibility of becoming a path to happiness. Among those conditions, the author highlights: the passage from a "heteronomous" morality to a morality of "theonomous" autonomy, a morality centered on the person rather than a morality

Determinação das propriedades termomecânicas de ligas Cu-Al-Ni e Cu-Al-Be com efeito memória de forma para utilização como atuadores mecânicos

OpenAIRE

Oliveira, Danniel Ferreira de

2009-01-01

Ligas Cu-Al-Ni e Cu-Al-Be forma elaboradas sob atmosfera ambiente e caracterizadas por microscopia, difração de R-X e Calorimetria Diferencial de varredura. Foram realizados nestas ligas ensaios de tração, recuperação de forma e superelasticidade. As propriedades termomecânicas destas ligas realizadas em diferentes temperaturas permitiu concluir que as ligas Cu-Al-Ni podem ser utilizadas como atuadores mecânicos para temperaturas acima de 90°C e que estas ligas não devem ser empregadas em tem...

Label-free in situ SERS imaging of biofilms.

Science.gov (United States)

Ivleva, Natalia P; Wagner, Michael; Szkola, Agathe; Horn, Harald; Niessner, Reinhard; Haisch, Christoph

2010-08-12

Surface-enhanced Raman scattering (SERS) is a promising technique for the chemical characterization of biological systems. It yields highly informative spectra, can be applied directly in aqueous environment, and has high sensitivity in comparison with normal Raman spectroscopy. Moreover, SERS imaging can provide chemical information with spatial resolution in the micrometer range (chemical imaging). In this paper, we report for the first time on the application of SERS for in situ, label-free imaging of biofilms and demonstrate the suitability of this technique for the characterization of the complex biomatrix. Biofilms, being communities of microorganisms embedded in a matrix of extracellular polymeric substances (EPS), represent the predominant mode of microbial life. Knowledge of the chemical composition and the structure of the biofilm matrix is important in different fields, e.g., medicine, biology, and industrial processes. We used colloidal silver nanoparticles for the in situ SERS analysis. Good SERS measurement reproducibility, along with a significant enhancement of Raman signals by SERS (>10(4)) and highly informative SERS signature, enables rapid SERS imaging (1 s for a single spectrum) of the biofilm matrix. Altogether, this work illustrates the potential of SERS for biofilm analysis, including the detection of different constituents and the determination of their distribution in a biofilm even at low biomass concentration.

La bioluminiscencia como recurso para potenciar la capacidad creativa del ser humano

OpenAIRE

Laugerud Tabarini, Isabel

2014-01-01

La bioluminiscencia, capacidad que poseen algunos organismos vivos de producir luz, ocurre mayormente en hábitats marinos donde raramente tiene testigos humanos. Al asombro natural que nos causa lo desconocido se le suma la particularidad de este fenómeno, poco representado y que además nos es solamente evidente en total ausencia de luz. Fuera de su zona de confort es donde el ser humano generalmente incrementa su habilidad de generar y/o conectar ideas para crear algo e implementarlo en su r...

Silver coated aluminium microrods as highly colloidal stable SERS platforms.

Science.gov (United States)

Pazos-Perez, Nicolas; Borke, Tina; Andreeva, Daria V; Alvarez-Puebla, Ramon A

2011-08-01

We report on the fabrication of a novel material with the ability to remain in solution even under the very demanding conditions required for structural and dynamic characterization of biomacromolecule assays. This stability is provided by the increase in surface area of a low density material (aluminium) natively coated with a very hydrophilic surface composed of aluminium oxide (Al(2)O(3)) and metallic silver nanoparticles. Additionally, due to the dense collection of active hot spots on their surface, this material offers higher levels of SERS intensity as compared with the same free and aggregated silver nanoparticles. This journal is © The Royal Society of Chemistry 2011

SERS Technique for Rapid Bacterial Screening

Science.gov (United States)

This study reports the feasibility of citrate-reduced colloidal silver SERS for differentiating E. coli, Listeria, and Salmonella. FT-Raman and SERS spectra of both silver colloids and colloid-K3PO4 mixtures were collected and analyzed to evaluate the reproducibility and stability of silver colloids...

El SERS como sensor de pH en entornos nanométricos

OpenAIRE

López-Tocón, Isabel

2015-01-01

La Espectroscopia SERS (Surface-Enhanced Raman Spectroscopy) se caracteriza por la enorme intensificación de la señal Raman de una molécula cuando se encuentra en las proximidades de una superficie metálica rugosa a escala nanométrica. Se trata, por tanto, de una técnica de alta sensibilidad que permite el registro de muestras a muy baja concentración y además, de alta selectividad, ya que únicamente aquellas moléculas que presenten un centro capaz de interaccionar con el metal, como un par ...

Disfruto el poder de ser feliz: experiencia en personas que viven con VIH

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Guadalupe Erendira Montoya Ramirez

2016-12-01

Full Text Available Las personas que viven con virus de inmunodeficiencia humana (VIH pueden presentar alteraciones biopsicosociales que generan infelicidad. La gaudibilidad (capacidad para ser feliz y disfrutar, puede favorecerse al crear nuevos patrones de conducta mental con la programación neurolingüística (PNL. El propósito fue: analizar la experiencia vivida en un taller de PNL para personas que viven con VIH, a la luz del referente teórico de; Rogers. Estudio cualitativo con diseño fenomenológico, participaron 12 personas de la Asociación CONVIHVE A.C. Michoacán, en un taller de PNL conformado por ocho sesiones. Tratamiento de datos por análisis de contenido, emergieron cinco dimensiones dejando ver el poder de cambio que tienen dichas personas para disfrutar la vida, al generar emociones positivas que se anclaron al inconsciente. Conclusiones. La PNL como intervención de enfermería favorece la gaudibilidad de las personas que viven con VIH.

SERS microscopy: plasmonic nanoparticle probes and biomedical applications

Science.gov (United States)

Gellner, M.; Schütz, M.; Salehi, M.; Packeisen, J.; Ströbel, P.; Marx, A.; Schmuck, C.; Schlücker, S.

2010-08-01

Nanoparticle probes for use in targeted detection schemes and readout by surface-enhanced Raman scattering (SERS) comprise a metal core, Raman reporter molecules and a protective shell. One design of SERS labels specifically optimized for biomedical applications in conjunction with red laser excitation is based on tunable gold/silver nanoshells, which are completely covered by a self-assembled monolayer (SAM) of Raman reporters. A shell around the SAM-coated metal core stabilizes the colloid and prevents particle aggregation. The optical properties and SERS efficiencies of these plasmonic nanostructures are characterized both experimentally and theoretically. Subsequent bioconjugation of SERS probes to ligands such as antibodies is a prerequisite for the selective detection of the corresponding target molecule via the characteristic Raman signature of the label. Biomedical imaging applications of SERS-labeled antibodies for tumor diagnostics by SERS microscopy are presented, using the localization of the tumor suppressor p63 in prostate tissue sections as an example.

Ser lo mismo, ser diferente: contra la masificación

OpenAIRE

Saldarriaga Roa, Alberto

2005-01-01

La sociedad moderna se ha configurado, en los dos últimos siglos, como una sociedad de masas. Esto parece ser una condición sine qua non de su estructura y operatividad. La masificación se manifiesta no sólo en el comportamiento social sino también en el

SERS-Based Prognosis of Kidney Transplant Outcome

Science.gov (United States)

Chi, Jingmao

Kidney transplant is the predominant procedure of all organ transplants around the world. The number of patients on the waiting list for a kidney is growing rapidly, yet the number of donations does not keep up with the fast-growing need. This thesis focuses on the surface-enhanced Raman scattering (SERS) analysis of urine samples for prognosis of kidney transplant outcome, which can potentially let patients have a more timely treatment as well as expand the organ pool for transplant. We have observed unique SERS spectral features from urine samples of kidney transplant recipients that have strong associations with the kidney acute rejection (AR) based on the analysis of urine one day after the transplant. Our ability to provide an early prognosis of transplant outcome is a significant advance over the current gold standard of clinical diagnosis, which occurs weeks or months after the surgical procedure. The SERS analysis has also been applied to urine samples from deceased kidney donors. Excellent classification ability was achieved when the enhanced PCA-LDA analysis was used to classify and identify urine samples from different cases. The sensitivity of the acute tubular necrosis (ATN) class is more than 90%, which can indicate the usable kidneys in the high failure risk category. This analysis can help clinicians identify usable kidneys which would be discarded using conventional clinic methods as high failure risk. To investigate the biomarkers that cause the unique SERS features, an HPLC-SERS-MS approach was established. The high-performance liquid chromatography (HPLC) was used to separate the urinary components to reduce the sample complexity. The mass spectrometry (MS) was used to determine the formulas and the structures of the biomarkers. The presence of 1-methyl-2-pyrrolidone (NMP) and adenine in urine samples were confirmed by both MS and SERS analysis. Succinylmonocholine, a metabolite of suxamethonium, has a potential to be the biomarker that causes

Factores asociados al desplazamiento activo en bicicleta al colegio en el Distrito Bogotá, Colombia. Estudio FUPRECOL

OpenAIRE

Beltrán Ahumada, César Augusto

2016-01-01

Introducción: El transporte activo (TA) puede ser una oportunidad para incrementar los niveles de actividad física diarios de los niños y adolescentes, además de destacarse como una estrategia práctica, accesible y sostenible a largo plazo. Objetivos: El objetivo del presente estudio es doble: Analizar los patrones de desplazamiento activo en bicicleta al y desde el centro educativo, y b) Identificar los factores asociados al uso de la bicicleta como TA; en una muestra de niños...

La condición humana desde la visión socio-antropológico-cultural del ser humano

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Dr. Cs. Homero Calixto Fuentes-González

2015-10-01

Full Text Available Se incursiona en la búsqueda de respuestas sobre la condición humana del sujeto contemporáneo, en la relación entre su existencia y esencia, para interpretar el desarrollo de la cultura desde el proceso de construcción del conocimiento científico acerca del ser humano como ser vivo que interactúa con el medio, lo transforma y se transforma a sí mismo, condicionando su naturaleza biológica y ecológica, en la unidad con lo social y lo espiritual.Al considerar el desarrollo de la condición humana se hace indispensable el reconocimiento de los estadios del progreso filogenético del ser humano, significando que son expresión de la identidad humana, la sensibilidad humana cultural y lo humano universal que trascienden en una sucesión continua y sistemática cuando se interpreta el desarrollo humano y se cualifica como dignidad humana en constante transformación.

La experiencia de ser cuidadora de un anciano con enfermedad crónica

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Gabriela Aldana-González

2011-01-01

Full Text Available Objetivo: conocer la construcción de la experiencia de ser cuidador de un anciano con enfermedad crónico-degenerativa en mujeres de San Cristóbal Ecatepec, México. Método: investigación de corte cualitativo, con cuatro personas de sexo femenino todas ellas cuidadoras de ancianos con enfermedades crónico-degenerativas. Se utilizó la entrevista a profundidad como técnica para la recolección de datos. Los datos se analizaron a partir de ubicar categorías de análisis desde una orientación fenomenológica. La investigación se llevó a cabo en la ciudad de San Cristóbal Ecatepec, Estado de México, México, entre marzo y junio del 2008. Resultados: el rol de cuidador está asignado a las mujeres. La categoría que aquí se describe se refiere a la cotidianidad del cuidado. Los discursos nos permiten develar el conflicto al que se enfrentan las cuidadoras: la responsabilidad moral del cuidado al adulto mayor y la necesidad de desarrollar un proyecto de vida autónomo. Conclusiones: la experiencia de ser cuidadora se asume como una responsabilidad y un compromiso moral que tiene que cumplirse por encima del cuidado personal. Tiene relación con la cultura mexicana respecto a la construcción de género y familia.

Enfermagem: uma maneira própria de ser, estar, pensar e fazer

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Maria Ribeiro Lacerda

1998-06-01

Full Text Available O presente ensaio busca estimular os enfermeiros e estudantes de Graduação e Pós-graduação de Enfermagem a terem cada vez mais conhecimento e orgulho dá Enfermagem. Trás uma explanação sintética da Enfermagem enquanto profissão, disciplina, ciência, arte, tecnologia e para além de ciência e arte. Considera a Enfermagem como algo que a enfermeiras criam ao cuidar de alguém através de um conhecimento profissional e de uma maneira própria de ser enfermeira.

Female-biased sex ratios in marine pelagic copepods: Comment on Gusmao et al. (2013)

DEFF Research Database (Denmark)

Hirst, Andrew G.; Bonnet, D; Conway, DVP

2013-01-01

Gusmao et al. (2013; Mar Ecol Prog Ser 482:279-298) review causes of sex ratio skew in pelagic copepods and in doing so repeatedly dispute the paper of Hirst et al. (2010) ‘Does predation control adult sex ratios and longevities in marine pelagic copepods?’ Here we respond to some important error...... in their citation of our paper and briefly highlight where future work is needed in order to attribute the causes of strong sex ratio skew seen in some copepod families......Gusmao et al. (2013; Mar Ecol Prog Ser 482:279-298) review causes of sex ratio skew in pelagic copepods and in doing so repeatedly dispute the paper of Hirst et al. (2010) ‘Does predation control adult sex ratios and longevities in marine pelagic copepods?’ Here we respond to some important errors...

Dynamic SERS nanosensor for neurotransmitter sensing near neurons.

Science.gov (United States)

Lussier, Félix; Brulé, Thibault; Bourque, Marie-Josée; Ducrot, Charles; Trudeau, Louis-Éric; Masson, Jean-François

2017-12-04

Current electrophysiology and electrochemistry techniques have provided unprecedented understanding of neuronal activity. However, these techniques are suited to a small, albeit important, panel of neurotransmitters such as glutamate, GABA and dopamine, and these constitute only a subset of the broader range of neurotransmitters involved in brain chemistry. Surface-enhanced Raman scattering (SERS) provides a unique opportunity to detect a broader range of neurotransmitters in close proximity to neurons. Dynamic SERS (D-SERS) nanosensors based on patch-clamp-like nanopipettes decorated with gold nanoraspberries can be located accurately under a microscope using techniques analogous to those used in current electrophysiology or electrochemistry experiments. In this manuscript, we demonstrate that D-SERS can measure in a single experiment ATP, glutamate (glu), acetylcholine (ACh), GABA and dopamine (DA), among other neurotransmitters, with the potential for detecting a greater number of neurotransmitters. The SERS spectra of these neurotransmitters were identified with a barcoding data processing method and time series of the neurotransmitter levels were constructed. The D-SERS nanosensor was then located near cultured mouse dopaminergic neurons. The detection of neurotransmitters was performed in response to a series of K + depolarisations, and allowed the detection of elevated levels of both ATP and dopamine. Control experiments were also performed near glial cells, showing only very low basal detection neurotransmitter events. This paper demonstrates the potential of D-SERS to detect neurotransmitter secretion events near living neurons, but also constitutes a strong proof-of-concept for the broad application of SERS to the detection of secretion events by neurons or other cell types in order to study normal or pathological cell functions.

O ser-enfermeiro em face do cuidado à criança no pós-operatório imediato de cirurgia cardíaca El ser-enfermero frente a la atención al niño en el posoperativo inmediato de cirugía cardíaca The nurse-being dealing with the care to the child in the immediate post-operative cardiac surgery

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Herwellyn Camilo de Melo

2012-09-01

Full Text Available Objetivou-se compreender o cuidado à criança durante o pós-operatório imediato de cirurgia cardíaca a partir da percepção do ser-enfermeiro. Utilizou-se a entrevista fenomenológica com seis enfermeiras lotadas na Unidade de Recuperação de Cirurgia Torácica do Pronto-Socorro Cardiológico de Pernambuco, de março a maio de 2011. A pesquisa é de natureza qualitativa com abordagem ancorada na fenomenologia existencial de Martin Heidegger. Os dados foram produzidos e analisados de acordo com os quatro momentos propostos por Martins e Bicudo. A análise permitiu delinear o cuidado do enfermeiro como sistemático, complexo e minucioso, que requer ao mesmo tempo aptidões técnico-científicas, exigindo do ser que cuida habilidade para lidar com seus sentimentos diante das eventualidades do dia a dia. Conclui-se que o cuidado à criança é construído em meio a uma dinâmica constitutiva entre tecnologias duras e subjetividade, onde haverá momentos em que uma será valorizada em detrimento da outra.Esta investigación objetivó analizar la atención al niño durante el posoperativo inmediato de cirugía cardíaca desde la percepción del ser-enfermero. La entrevista fenomenológica se llevó a cabo con seis enfermeras que trabajan en la Unidad de Recuperación de Cirugía Torácica del Pronto-Socorro Cardiológico de Pernambuco, de marzo a mayo de 2011. La investigación tiene naturaleza cualitativa con abordaje anclado en la fenomenología existencial de Martin Heidegger. Los datos fueron producidos y analizados según los cuatro momentos sugeridos por Martins y Bicudo. El análisis permitió delinear la atención del enfermero como sistemática, complexa y minuciosa, que requiere al mismo tiempo aptitudes técnicas y científicas, exigiendo del ser que cuida habilidad para lidiar con sus sentimientos en las eventualidades del día a día. Se concluye que la atención al niño es construida en medio a una dinámica constitutiva entre

SER Y ESTAR CON ADJETIVOS – SIGNIFICACION DE LAS PROPOSICIONES SER Y ESTAR CON ADJETIVOS – SIGNIFICACION DE LAS PROPOSICIONES

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Javier García de María

2008-07-01

Full Text Available Ser y estar: uno de los temas difíciles de la enseñanza/aprendizaje del español. Este trabajo expone un enfoque que recurre a la significación como hilo conductor. Por una parte, a la significación de ser y de estar como verbos, en sí mismos. Por otra, a la significación de los adjetivos. El planteamiento no es ya qué significa un determinado adjetivo con ser o con estar, sino cuál de estos verbos puede expresar su significado único o cada uno de sus significados. Sobre esta base el análisis considera, primero, los significados de ser/estar y los significados de un adjetivo dado y, segundo, los resultados significativos que arroja la relación entre verbos y adjetivo. Cuando el significado de un adjetivo se pueda expresar con los dos verbos, la elección vendrá determinada por la intencionalidad del hablante en el contexto comunicativo en que se encuentre. A partir de aquí las construcciones en las que aparecen ser y estar son tratadas como proposiciones retórico-argumentativas.Ser and estar: a difficult aspect of Spanish as a foreign language. This essay presents an approach that takes signification as guide line. On the one hand, the signification of ser and estar for their own cause; on the other hand the signification of the adjectives. The question is no longer what the meaning of a given adjective is with ser or with estar, but with which of the two verbs is it possible to express the unique meaning or each of the meanings of that adjective. Starting from this basis the approach considers first, the isolated meanings of the verbs and of the adjectives and, second, the resultant signification out of the relation between the two sides. If the meaning of a given adjective can be expressed by both verbs, the selection of the verb is determined by the intentionality of the speaker in the communicative context in which he negotiates. From this background on the syntactical constructions in which ser and estar appear are treated as

Reassessing SERS enhancement factors: using thermodynamics to drive substrate design.

Science.gov (United States)

Guicheteau, J A; Tripathi, A; Emmons, E D; Christesen, S D; Fountain, Augustus W

2017-12-04

Over the past 40 years fundamental and application research into Surface-Enhanced Raman Scattering (SERS) has been explored by academia, industry, and government laboratories. To date however, SERS has achieved little commercial success as an analytical technique. Researchers are tackling a variety of paths to help break through the commercial barrier by addressing the reproducibility in both the SERS substrates and SERS signals as well as continuing to explore the underlying mechanisms. To this end, investigators use a variety of methodologies, typically studying strongly binding analytes such as aromatic thiols and azarenes, and report SERS enhancement factor calculations. However a drawback of the traditional SERS enhancement factor calculation is that it does not yield enough information to understand substrate reproducibility, application potential with another analyte, or the driving factors behind the molecule-metal interaction. Our work at the US Army Edgewood Chemical Biological Center has focused on these questions and we have shown that thermodynamic principles play a key role in the SERS response and are an essential factor in future designs of substrates and applications. This work will discuss the advantages and disadvantages of various experimental techniques used to report SERS enhancement with planar SERS substrates and present our alternative SERS enhancement value. We will report on three types of analysis scenarios that all yield different information concerning the effectiveness of the SERS substrate, practical application of the substrate, and finally the thermodynamic properties of the substrate. We believe that through this work a greater understanding for designing substrates will be achieved, one that is based on both thermodynamic and plasmonic properties as opposed to just plasmonic properties. This new understanding and potential change in substrate design will enable more applications for SERS based methodologies including targeting

Ventajas de la cicatrización cutánea asistida por láser (LASH

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S. Mordon

Full Text Available La fase final de toda cirugía es la sutura y su cicatriz correspondiente y, frecuentemente, ésta es la única secuela visible de una intervención. La técnica LASH (cicatrización cutánea asistida por láser, estimula los mecanismos de reparación de la piel por efecto térmico, condicionando la calidad de la cicatrización. Estudios experimentales en ratones comparando los resultados obtenidos en heridas quirúrgicas radiadas con laser diodo 810 nm tras ser suturadas, con los obtenidos en igual tipo de heridas suturadas de manera convencional, han demostrado que se consiguen cicatrices mucho menos visibles cuando se practica el tratamiento con láser. La histología confirma, comparativamente, una notable aceleración del proceso cicatricial con modificación del TGFβ (Transforming Growth Factor-Beta directamente implicado en la reparación tisular, en los animales en los que la sutura fue asistida por láser. Igualmente, el análisis tensiométrico demostró mayor resistencia a la acción de estiramiento mecánico en estas heridas. Estudios clínicos en pacientes sometidos a dermolipectomia, reducción mamaria y estiramiento facial, demuestran que al tratar con LASH una parte o una de las líneas de sutura, los análisis realizados tanto por los pacientes como por cirujanos independientes a los 8 días, 3 meses y un año, evidencian resultados más favorables para la técnica láser, Las dosis eficaces determinadas para las fluencias láser están entre 80 y 120 J/cm². La técnica LASH es simple de efectuar, reproducible, rápida y ofrece una clara evidencia de que es posible reducir considerablemente la cicatriz, logrando que ésta sea de mejor calidad y más estética.

The frequency of genotypes for the SNP Ser/Ser in the studied population of Albanian women is higher in the Balkan region

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Zafer Gashi

2016-08-01

Full Text Available In women undergoing natural cycles, just one oocyte is usually selected for ovulation, yet routine clinical techniques to support the development of multiple follicles using additional gonadotrophins result in numerous ovulations. Several parameters have been postulated as predictors of ovarian response (inhibin B, 17-β-estradiol and antiMüllerian hormone. Nevertheless, the FSH level on the day 3 of menstrual cycle remains, the most widely used biomarker due to its low cost, although, the genetic background of individuals seems to determine the response of patients to rFSH stimulation better than the stimulation design. Consequently, the variants of FSHR were explored and they may be involved in the role of FSH receptor in mediated signal transduction and with ovarian response in infertile women submitted to ovarian stimulation. In this study we examined, for the first time, the prevalence of genotype variants Asn680Ser in population Albanian women from Kosovo Dukagjin region who took part in IVF / ICSI program. The frequencies of the Asn680Ser genotype variants were as follows: Asn/Asn 22.1%, Asn/Ser 47.1%, and Ser/Ser 30.8%, respectively (Table 1. bE2 levels between the three genotype variants showed slight but statistically significant difference (p= 0.0308. No difference was also found between the genotype groups either in terms of AFC, amount of the FSH required for ovulation induction, stimulation length days, number of dominant follicles, oocyte retrieval number or endometrial thickness (Table 2. BMI was significantly higher in the Ser/Ser group as compared to those from the Asn/Ser or the Asn/Asn group (p= 0.0010 (Table 2. In the study population of Albanian women Dukagjin region of Kosovo had a higher incidence of Ser / SER genotype compared to Asn / Asn genotype. Our research results in the Albanian population differ from published data for other ethnic groups in the Balkans.

La «historia de los omeyas de al-Andalus» en los Masālik al-Abṣār

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Molina, Luis

2005-06-01

Full Text Available The Māsilik al-abṣār by Ibn Faḍl Allāh al-'Umarī contains a brief summary of the Umayyad history in al-Andalus. In this article, the textual relationship between this passage and the Muqtabis by Ibn Ḥayyān is analysed. Ibn Ḥayyān's chronicle has proved to be the most important source used by al-'Umarī to compose this chapter.

Los Māsilik al-abṣār de Ibn Faḍl Allāh al-'Umarī incluyen un breve resumen de la Historia de los omeyas de al-Andalus. En este trabajo se analizan las relaciones textuales entre ese pasaje y el Muqtabis de Ibn Ḥayyān, crónica que resulta ser la fuente casi única utilizada por al-'Umarī para redactar ese capítulo.

The IkappaB kinase family phosphorylates the Parkinson's disease kinase LRRK2 at Ser935 and Ser910 during Toll-like receptor signaling.

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Nicolas Dzamko

Full Text Available Mutations in leucine-rich repeat kinase 2 (LRRK2 are strongly associated with late-onset autosomal dominant Parkinson's disease. LRRK2 is highly expressed in immune cells and recent work points towards a link between LRRK2 and innate immunity. Here we demonstrate that stimulation of the Toll-Like Receptor (TLR pathway by MyD88-dependent agonists in bone marrow-derived macrophages (BMDMs or RAW264.7 macrophages induces marked phosphorylation of LRRK2 at Ser910 and Ser935, the phosphorylation sites that regulate the binding of 14-3-3 to LRRK2. Phosphorylation of these residues is prevented by knock-out of MyD88 in BMDMs, but not the alternative TLR adaptor protein TRIF. Utilising both pharmacological inhibitors, including a new TAK1 inhibitor, NG25, and genetic models, we provide evidence that both the canonical (IKKα and IKKβ and IKK-related (IKKε and TBK1 kinases mediate TLR agonist induced phosphorylation of LRRK2 in vivo. Moreover, all four IKK members directly phosphorylate LRRK2 at Ser910 and Ser935 in vitro. Consistent with previous work describing Ser910 and Ser935 as pharmacodynamic biomarkers of LRRK2 activity, we find that the TLR independent basal phosphorylation of LRRK2 at Ser910 and Ser935 is abolished following treatment of macrophages with LRRK2 kinase inhibitors. However, the increased phosphorylation of Ser910 and Ser935 induced by activation of the MyD88 pathway is insensitive to LRRK2 kinase inhibitors. Finally, employing LRRK2-deficient BMDMs, we present data indicating that LRRK2 does not play a major role in regulating the secretion of inflammatory cytokines induced by activation of the MyD88 pathway. Our findings provide the first direct link between LRRK2 and the IKKs that mediate many immune responses. Further work is required to uncover the physiological roles that phosphorylation of LRRK2 by IKKs play in controlling macrophage biology and to determine how phosphorylation of LRRK2 by IKKs impacts upon the use of Ser

Síntesis de nanopartículas de plata por ablación láser funcionalizadas con bicapa de grafeno

OpenAIRE

Damián Briones, María Angelica; Damián Briones, María Angelica; Damián Briones, María Angelica

2015-01-01

En este trabajo se obtuvo nanopartículas de plata por ablación laser para luego ser funcionalizadas con bicapa de grafeno, mediante la técnica de evaporación. Para la obtención de las nanopartículas de plata se usó un “target” de plata al 99,9% de pureza el cual fue colocado dentro de un recipiente que contenía agua ultrapura, sobre él se incidió un láser de Nd:AYG modelo Brillant, en el cual se pudo controlar la fluencia, longitud de onda, el medio y el tiempo de ablación. Para la obte...

Libertas que serás enfermagem

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Mary Anne Fontenele Martins

1998-09-01

Full Text Available O título deste ensaio nos faz lembrar a Inconfidência Mineira, que teve como líder José Joaquim da Silva Xavier, o Tiradentes, sendo um movimento que ansiava por liberdade, assim como a enfermagem que, ao longo dos anos, vem construindo sua história e caminhando em busca de sua autonomia. A presente pesquisa tem como objetivo investigar os caminhos percorridos pela enfermagem, enquanto ciência na busca de sua autonomia, e refletir sobre a atuação do enfermeiro enquanto profissional criativo e autônomo. Estudo respaldado no materialismo histórico e dialético, realizado no período de maio a agosto de 1997 com enfermeiras do Estado do Ceará, que estão envolvidas com o processo histórico da profissão. Os resultados deram origem a uma categoria central, prática profissional e outras três: autonomia, criatividade e disposição para enfrentar desafios, que favoreceram uma melhor compreensão dos caminhos já trilhados pela enfermagem, além de nos permitir entender que o enfermeiro pode ser autônomo e livre.

SERS-based application in food analytics (Conference Presentation)

Science.gov (United States)

Cialla-May, Dana; Radu, Andreea; Jahn, Martin; Weber, Karina; Popp, Jürgen

2017-02-01

To establish detection schemes in life science applications, specific and sensitive methods allowing for fast detection times are required. Due to the interaction of molecules with strong electromagnetic fields excited at metallic nanostructures, the molecular fingerprint specific Raman spectrum is increased by several orders of magnitude. This effect is described as surface-enhanced Raman spectroscopy (SERS) and became a very powerful analytical tool in many fields of application. Within this presentation, we will introduce innovative bottom-up strategies to prepare SERS-active nanostructures coated with a lipophilic sensor layer. To do so, the food colorant Sudan III, an indirect carcinogen substance found in chili powder, palm oil or spice mixtures, is detected quantitatively in the background of the competitor riboflavin as well as paprika powder extracts. The SERS-based detection of azorubine (E122) in commercial available beverages with different complexity (e.g. sugar content, alcohol concentration) illustrates the strong potential of SERS as a qualitative as well as semiquantitative prescan method in food analytics. Here, a good agreement between the estimated concentration employing SERS as well as the gold standard technique HPLC, a highly laborious method, is found. Finally, SERS is applied to detect vitamin B2 and B12 in cereals as well as the estimate the ratio of lycopene and β-carotene in tomatoes. Acknowledgement: Funding the projects "QuantiSERS" and "Jenaer Biochip Initiative 2.0" within the framework "InnoProfile Transfer - Unternehmen Region" the Federal Ministry of Education and Research, Germany (BMBF) is gratefully acknowledged.

Como gostaria de ser cuidado na velhice? Opiniões dos Conselheiros Municipais de Saúde da Região Metropolitana de São Paulo.

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Ruth Gelehrter da Costa LOPES

2014-12-01

Full Text Available Sabendo-se que a participação da comunidade contribui em nível local para a formulação de estratégias e controle da execução das políticas de saúde, o objetivo deste estudo consistiu em apresentar as opiniões de Conselheiros atuantes na Região Metropolitana de São Paulo (RMSP sobre como gostariam de ser cuidados em 2030, marco temporal em alusão à própria velhice. Adotamos o método descritivo para interpretação de entrevistas semiestruturadas conduzidas com 39 sujeitos voluntários. Além de revelar o perfil sociodemográfico do Conselheiro de Saúde da RMSP, identificou-se que os entrevistados adotaram, de forma não diretiva, três outras categorias significativas em suas falas além do ‘como ser cuidado’, a saber: ‘por quem’, ‘onde’ e ‘quando’. As opiniões colhidas refletem uma carga de idealização e contraste com o cuidado que se entende ser direcionado pelo SUS ao idoso na atualidade.

Graphene-Plasmonic Hybrid Platform for Label-Free SERS Biomedical Detection

Science.gov (United States)

Wang, Pu

Surface Enhanced Raman Scattering (SERS) has attracted explosive interest for the wealth of vibrational information it provides with minimal invasive effects to target analyte. Nanotechnology, especially in the form of noble metal nanoparticles exhibit unique electromagnetic and chemical characteristics that are explored to realize ultra-sensitive SERS detection in chemical and biological analysis. Graphene, atom-thick carbon monolayer, exhibits superior chemical stability and bio-compatibility. A combination of SERS-active metal nanostructures and graphene will create various synergies in SERS. The main objective of this research was to exploit the applications of the graphene-Au tip hybrid platform in SERS. The hybrid platform consists of a periodic Au nano-pyramid substrate to provide reproducible plasmonic enhancement, and the superimposed monolayer graphene sheet, serving as "built-in" Raman marker. Extensive theoretical and experimental studies were conducted to determine the potentials of the hybrid platform as SERS substrate. Results from both Finite-Domain Time-Domain (FDTD) numerical simulation and Raman scattering of graphene suggested that the hybrid platform boosted a high density of hotspots yielding 1000 times SERS enhancement of graphene bands. Ultra-high sensitivity of the hybrid platform was demonstrated by bio-molecules including dye, protein and neurotransmitters. Dopamine and serotonin can be detected and distinguished at 10-9 M concentration in the presence of human body fluid. Single molecule detection was obtained using a bi-analyte technique. Graphene supported a vibration mode dependent SERS chemical enhancement of ˜10 to the analyte. Quantitative evaluation of hotspots was presented using spatially resolved Raman mapping of graphene SERS enhancement. Graphene plays a crucial role in quantifying SERS hotspots and paves the path for defining SERS EF that could be universally applied to various SERS systems. A reproducible and statistically

Ser649 and Ser650 are the major determinants of protein kinase A-mediated activation of human hormone-sensitive lipase against lipid substrates

DEFF Research Database (Denmark)

Krintel, Christian; Osmark, Peter; Larsen, Martin Røssel

2008-01-01

Hormone-sensitive lipase (HSL) is a key enzyme in the mobilization of fatty acids from stored triacylglycerols. Its activity is regulated by reversible protein phosphorylation. In rat HSL Ser563, Ser659 and Ser660 have been shown to be phosphorylated by protein kinase A (PKA) in vitro as well...

La fundamentalidad del derecho al agua en Colombia

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Mies Sutorius

2015-12-01

Full Text Available El agua es un recurso natural finito de vital importancia para el ser humano, lo que explica que con el paso del tiempo se busque con mayor fuerza su protección, no solo en el ámbito internacional sino también en el orden jurídico interno. De ahí el interés en realizar una revisión normativa y especialmente jurisprudencial que permita evidenciar la evolución del derecho al agua, los matices y las diversas formas de protección del mismo, profundizando en su dimensión personal. La Constitución Política colombiana omite enunciar el derecho al agua como derecho individual, razón por la cual se procede a estudiar la jurisprudencia constitucional, seleccionándose algunas sentencias en donde existen sujetos de especial protección, en tanto al reconocerse a estos la vulneración y garantía de derechos se prevé la protección de los derechos del resto de la población; así como algunos casos en donde existen condiciones particulares, a partir de la suspensión del servicio por falta de pago a la empresa encargada del suministro, conexión fraudulenta y reconexión ilegal; para concluir que se han presentado dos tendencias en el amparo de este derecho, que ha pasado de ser protegido por vía de la “teoría de la conexidad” a ser catalogado como fundamental con una tutela restringida a la cantidad mínima necesaria para sobrevivir.

Ser lugar e ser território como experiências do ser-no-mundo: um exercício de existencialismo geográfico

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Angelo Serpa

2017-10-01

Full Text Available Este ensaio busca aprofundar uma abordagem existencialista dos conceitos de lugar e território assumindo o pressuposto de que eles remetem, antes de tudo, a experiências geográficas que ora se distinguem, ora se aproximam e carregam em si a marca do espaço vivido. Para esta análise, parte-se do conceito de geograficidade – a base pré-consciente e pré-conceitual da geografia – assumindo também que, antes de qualquer conceituação ou estratégia de representação conceitual, as pessoas são seres essencialmente espaciais e que viver é produzir/experienciar espaço. O ensaio está dividido em seis seções: a introdução, uma problematização da dialética entre interior e exterior e seu desdobramento numa abordagem de como lugar e território se exprimem como modos geográficos de existência no espaço público; nas duas últimas seções, reflete-se sobre o papel do corpo nos processos de apropriação do espaço e sobre como ser lugar e ser território se exprimem como facetas do ser-no-mundo em seu sentido mais político.

Security effectiveness review (SER)

International Nuclear Information System (INIS)

Kouprianova, I.; Ek, D.; Showalter, R.; Bergman, M.

1998-01-01

As part of the on-going DOE/Russian MPC and A activities at the Institute of Physics and Power Engineering (IPPE) and in order to provide a basis for planning MPC and A enhancements, an expedient method to review the effectiveness of the MPC and A system has been adopted. These reviews involve the identification of appropriate and cost-effective enhancements of facilities at IPPE. This effort requires a process that is thorough but far less intensive than a traditional vulnerability assessment. The SER results in a quick assessment of current and needed enhancements. The process requires preparation and coordination between US and Russian analysts before, during, and after information gathering at the facilities in order that the analysis is accurate, effective, and mutually agreeable. The goal of this paper is to discuss the SER process, including the objectives, time scale, and lessons learned at IPPE

and Au nanoparticles for SERS applications

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Fazio Enza

2018-01-01

Full Text Available The morphological and optical properties of noble metal nanoparticles prepared by picosecond laser generated plasmas in water were investigated. First, the ablation efficiency was maximized searching the optimal focusing conditions. The nanoparticle size, measured by Scanning Transmission Electron Microscopy, strongly depends on the laser fluence, keeping fixed the other deposition parameters such as the target to scanner objective distance and laser repetition frequency. STEM images indicate narrow gradients of NP sizes. Hence the optimization of ablation parameters favours a fine tuning of nanoparticles. UV-Visible spectroscopy helped to determine the appropriate laser wavelength to resonantly excite the localized surface plasmon to carry out Surface Enhanced Raman Scattering (SERS measurements. The SERS activity of Ag and Au substrates, obtained spraying the colloids synthesized in water, was tested using crystal violet as a probe molecule. The good SERS performance, observed at excitation wavelength 785 nm, is attributed to aggregation phenomena of nanoparticles sprayed on the support.

Dynamic phosphorylation of RelA on Ser42 and Ser45 in response to TNFα stimulation regulates DNA binding and transcription.

Science.gov (United States)

Lanucara, Francesco; Lam, Connie; Mann, Jelena; Monie, Tom P; Colombo, Stefano A P; Holman, Stephen W; Boyd, James; Dange, Manohar C; Mann, Derek A; White, Michael R H; Eyers, Claire E

2016-07-01

The NF-κB signalling module controls transcription through a network of protein kinases such as the IKKs, as well as inhibitory proteins (IκBs) and transcription factors including RelA/p65. Phosphorylation of the NF-κB subunits is critical for dictating system dynamics. Using both non-targeted discovery and quantitative selected reaction monitoring-targeted proteomics, we show that the cytokine TNFα induces dynamic multisite phosphorylation of RelA at a number of previously unidentified residues. Putative roles for many of these phosphorylation sites on RelA were predicted by modelling of various crystal structures. Stoichiometry of phosphorylation determination of Ser45 and Ser42 revealed preferential early phosphorylation of Ser45 in response to TNFα. Quantitative analyses subsequently confirmed differential roles for pSer42 and pSer45 in promoter-specific DNA binding and a role for both of these phosphosites in regulating transcription from the IL-6 promoter. These temporal dynamics suggest that RelA-mediated transcription is likely to be controlled by functionally distinct NF-κB proteoforms carrying different combinations of modifications, rather than a simple 'one modification, one effect' system. © 2016 The Authors.

NEK1 genetic variability in a Belgian cohort of ALS and ALS-FTD patients.

Science.gov (United States)

Nguyen, Hung Phuoc; Van Mossevelde, Sara; Dillen, Lubina; De Bleecker, Jan L; Moisse, Matthieu; Van Damme, Philip; Van Broeckhoven, Christine; van der Zee, Julie

2018-01-01

We evaluated the genetic impact of the amyotrophic lateral sclerosis (ALS) risk gene never in mitosis gene a-related kinase 1 (NEK1) in a Belgian cohort of 278 patients with ALS (n = 245) or ALS with frontotemporal dementia (ALS-FTD, n = 33) and 609 control individuals. We identified 2 ALS patients carrying a loss-of-function (LOF) mutation, p.Leu854Tyrfs*2 and p.Tyr871Valfs*17, that was absent in the control group. A third LOF variant p.Ser1036* was present in 2 sibs with familial ALS but also in an unrelated control person. Missense variants were common in both patients (3.6%) and controls (3.0%). The missense variant, p.Arg261His, which was previously associated with ALS risk, was detected with a minor allele frequency of 0.90% in patients compared to 0.33% in controls. Taken together, NEK1 LOF variants accounted for 1.1% of patients, although interpretation of pathogenicity and penetrance is complicated by the observation of occasional LOF variants in unaffected individuals (0.16%). Furthermore, enrichment of additional ALS gene mutations was observed in NEK1 carriers, suggestive of a "second hit" model were NEK1 variants may modify disease presentation of driving mutations. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Characterization of the interaction layer in diffusion couples U-Mo-Zr/Al and U-Mo-Zr/Al-A356 at 550 C degrees; Caracterizacion de la zona de interaccion en pares de difusion a 550 grados C U-Mo-Zr/Al y U-Mo-Zr/Al-A356

Energy Technology Data Exchange (ETDEWEB)

Komar Varela, Carolina; Arico, Sergio; Mirandou, Marcela; Balart, Silvia; Gribaudo, Luis [Comision Nacional de Energia Atomica, General San Martin (Argentina). Dept. de Materiales; com, carolinakomar@gmail

2007-07-01

Out-of-pile diffusion experiments were performed between U-7 wt.% Mo-1 wt.% Zr and Al or Al A356 (7,1 wt.% Si) at 550 C degrees. In this work morphological characterization and phase identification on both interaction layers are presented. They were carried out by the use of different techniques: optical and scanning electron microscopy, X-ray diffraction and WDS microanalysis. In the interaction layer U-7 wt.% Mo-1 wt.% Zr/Al, the phases UAl{sub 3}, UAl{sub 4}, Al{sub 20}Mo{sub 2}U and Al{sub 43}Mo{sub 4}U{sub 6} were identified. Similar results in the interaction layer of the U-7 % Mo/Al at 580 C degrees were previously obtained. In the interaction layer U-7 wt.% Mo-1 wt.% Zr/Al A356, the phases U(Al,Si){sub 3} with 25 at.% Si and Si{sub 5}U{sub 3} were identified. This last phase, with a higher Si concentration, was identified with X-ray diffraction synchrotron radiation performed at the National Synchrotron Light Laboratory, Campinas, Brazil. (author) [Spanish] Se realizaron experiencias fuera de reactor en pares de difusion quimica U-7 % Mo-1 % Zr/Al y U-7 % Mo-1 % Zr/Al A356. En este trabajo se presentan los resultados de la caracterizacion morfologica e identificacion de fases presentes en la zona de interaccion que se forma al ser sometidos a un tratamiento isotermico de 1,5 h a 550 grados C. Las tecnicas utilizadas fueron: microscopia optica y electronica de barrido, difraccion de rayos X y microanalisis cuantitativo por sonda electronica. En la zona de interaccion correspondiente al par U-7 % Mo-1 % Zr/Al se identificaron las fases UAl{sub 3}, UAl{sub 4}, Al{sub 20}Mo{sub 2}U y Al{sub 43}Mo{sub 4}U{sub 6}. Estas cuatro fases fueron identificadas en pares U-7 % Mo/Al a 580 grados C en trabajos anteriores. En la zona de interaccion correspondiente al par U-7 % Mo-1 % Zr/Al A356 se identificaron las fases U(Al,Si){sub 3} (con una concentracion de 25 %at.Si) y Si{sub 5}U{sub 3}. Este compuesto rico en Si solo pudo ser identificado mediante la utilizacion de

“Mató para ser un hombre completo”. Aproximaciones al estatuto de masculinidad de los sesenta y setenta en la Argentina

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Patricio Simonetto

2015-03-01

Full Text Available Este trabajo inicia con la denuncia de un grupo de homosexuales sobre la decisión de un juez de liberar a un muchacho tras un asesinato, con la argumentación de que "mató" para ser un hombre. Desde este punto se propone reflexionar sobre los modos de ser y existir, de imaginar y se imaginados, de los varones argentinos durante las décadas del sesenta y setenta. Para esto se vale del análisis de obras literarias claves del período, como así también, de la reconstrucción de los principales cambios operados en el siglo xx. De este modo, se propone entender los cambios en los patrones de género con relación a cambios socio-económicos, culturales y políticos que afectaron a la Argentina.

Photonic Crystal Fibre SERS Sensors Based on Silver Nanoparticle Colloid

International Nuclear Information System (INIS)

Zhi-Guo, Xie; Yong-Hua, Lu; Pei, Wang; Kai-Qun, Lin; Jie, Yan; Hai, Ming

2008-01-01

A photonic crystal fibre (PCF) surface enhanced Raman scattering (SERS) sensor is developed based on silver nanoparticle colloid. Analyte solution and silver nanoparticles are injected into the air holes of PCF by a simple modified syringe to overcome mass-transport constraints, allowing more silver nanoparticles involved in SERS activity. This sensor offers significant benefit over the conventional SERS sensor with high flexibility, easy manufacture. We demonstrate the detection of 4-mercaptobenzoic acid (4-MBA) molecules with the injecting way and the common dipping measurement. The injecting way shows obviously better results than the dipping one. Theoretical analysis indicates that this PCF SERS substrate offers enhancement of about 7 orders of magnitude in SERS active area

Single molecule SERS: Perspectives of analytical applications

Czech Academy of Sciences Publication Activity Database

Vlčková, B.; Pavel, I.; Sládková, M.; Šišková, K.; Šlouf, Miroslav

834-836, - (2007), s. 42-47 ISSN 0022-2860. [European Congress on Molecular Spectroscopy /28./. Istanbul, 03.09.2006-08.09.2006] R&D Projects: GA ČR GA203/04/0688 Institutional research plan: CEZ:AV0Z40500505 Keywords : surface-enhanced Raman scattering (SERS) * surface-enhanced resonance Raman (SERRS) * single molecule SERS Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.486, year: 2007

Taladrado de pizarra mediante láser de Nd:Yag

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Larosi, M. S.

1998-04-01

Full Text Available A serie of experiments to investigate the feasibility of using a Nd: YAG laser to process slate tiles and the influence of the processing parameters have been undertaken. The objective of this work is to investigate the capabilities of a Nd:YAG pulsed laser to drill tiny holes in slate tiles, in order to produce a better quality drilled slate tile in a reduced time. Part of the results obtained in a systematic study about the influence of the processing parameters, such as average power, pulse width, frequency, pressure and type of assisting gas is presented.

Se ha desarrollado una serie de experimentos para investigar la viabilidad del uso de un láser de Nd: YAG para el procesamiento de piezas de pizarra, así como los parámetros que más afectan al proceso. El objetivo concreto de este trabajo es investigar la capacidad de un láser de Nd:YAG pulsado para taladrar orificios de pequeño diámetro en láminas de pizarra, con el fin de obtener mejor calidad de taladrado en un tiempo reducido. Se presenta parte de los resultados obtenidos en un estudio sistemático de la influencia de los parámetros de procesamiento en la forma del orificio, tales como, potencia, duración de pulso, frecuencia, presión y tipo de gas de aportación.

Development of SERS active fibre sensors

International Nuclear Information System (INIS)

Polwart, Ewan

2002-01-01

Surface-enhanced Raman scattering (SERS) is sensitive and selective and when coupled with fibre-optics could potentially produce an effective chemical sensing system. This thesis concerns the development of a single-fibre-based sensor, with an integral SERS-active substrate. A number of different methods for the manufacture of SERS-active surfaces on glass substrates were investigated and compared. The immobilisation of metal nanoparticles on glass functionalised with (3-aminopropyl)trimethoxysilane emerged as a suitable approach for the production of sensors. Substrates prepared by this approach were characterised using UV-visible spectroscopy, electron microscopy and Raman mapping. It was found that exposure of substrates to laser radiation led to a decrease in the signal recorded from adsorbed analytes. This speed of the decrease was shown to depend on the analyte, and the exciting wavelength and power. SERS-active fibre sensors were produced by immobilisation of silver nanoparticles at the distal end of a (3-aminopropyl)trimethoxysilane-derivatised optical fibre. These sensors were used to obtain spectra with good signal to noise ratios from 4-(benzotriazol-5-ylazo)-3,5-dimethoxyphenylamine and crystal violet. Sensing of dyes in effluent was also investigated. The development of sensors for the measurement of pH, by treating the SERS-active fibre tip with pH sensitive dyes is also described. Spectral changes were observed with these sensors as a response to the pH. Partial least squares regression was used to produce linear calibration models for the pH range 5-11 from which it was possible to predict the pH with an accuracy of ∼0.2 pH units. Some of the limitations of these sensors were explored. The feasibility of using these sensors for measurement of oxygen and thiols, was investigated. The measurement of oxygen using methylene blue as a transducer was demonstrated. Two transduction methodologies--reactions with iron porphyrins and pyrrole-2,5-diones

Superhydrophobic Ag nanostructures on polyaniline membranes with strong SERS enhancement.

Science.gov (United States)

Liu, Weiyu; Miao, Peng; Xiong, Lu; Du, Yunchen; Han, Xijiang; Xu, Ping

2014-11-07

We demonstrate here a facile fabrication of n-dodecyl mercaptan-modified superhydrophobic Ag nanostructures on polyaniline membranes for molecular detection based on SERS technique, which combines the superhydrophobic condensation effect and the high enhancement factor. It is calculated that the as-fabricated superhydrophobic substrate can exhibit a 21-fold stronger molecular condensation, and thus further amplifies the SERS signal to achieve more sensitive detection. The detection limit of the target molecule, methylene blue (MB), on this superhydrophobic substrate can be 1 order of magnitude higher than that on the hydrophilic substrate. With high reproducibility, the feasibility of using this SERS-active superhydrophobic substrate for quantitative molecular detection is explored. A partial least squares (PLS) model was established for the quantification of MB by SERS, with correlation coefficient R(2) = 95.1% and root-mean-squared error of prediction (RMSEP) = 0.226. We believe this superhydrophobic SERS substrate can be widely used in trace analysis due to its facile fabrication, high signal reproducibility and promising SERS performance.

Surface enhanced Raman scattering (SERS) fabrics for trace analysis

International Nuclear Information System (INIS)

Liu, Jun; Zhou, Ji; Tang, Bin; Zeng, Tian; Li, Yaling; Li, Jingliang; Ye, Yong; Wang, Xungai

2016-01-01

Highlights: • Gold nanoparticles are in-situ synthesized on silk fabrics by heating. • Flexible silk fabrics with gold nanoparticles are used for surface-enhanced Raman scattering (SERS). • SERS activities of silk fabrics with different gold contents are investigated. - Abstract: Flexible SERS active substrates were prepared by modification of silk fabrics with gold nanoparticles. Gold nanoparticles were in-situ synthesized after heating the silk fabrics immersed in gold ion solution. Localized surface plasmon resonance (LSPR) properties of the treated silk fabrics varied as the concentration of gold ions changed, in relation to the morphologies of gold nanoparticles on silk. In addition, X-ray diffraction (XRD) was used to observe the structure of the gold nanoparticle treated silk fabrics. The SERS enhancement effect of the silk fabrics treated with gold nanoparticles was evaluated by collecting Raman signals of different concentrations of p-aminothiophenol (PATP), 4-mercaptopyridine (4-MPy) and crystal violet (CV) solutions. The results demonstrate that the silk fabrics corresponding to 0.3 and 0.4 mM of gold ions possess high SERS activity compared to the other treated fabrics. It is suggested that both the gold content and morphologies of gold nanoparticles dominate the SERS effect of the treated silk fabrics.

Surface enhanced Raman scattering (SERS) fabrics for trace analysis

Energy Technology Data Exchange (ETDEWEB)

Liu, Jun [National Engineering Laboratory for Advanced Yarn and Fabric Formation and Clean Production, Wuhan Textile University, Wuhan 430073 (China); Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials & Key Laboratory for the Synthesis and Application of Organic Functional Molecules, Ministry of Education & College of Chemistry & Chemical Engineering, Hubei University, Wuhan 430062 (China); Zhou, Ji [Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials & Key Laboratory for the Synthesis and Application of Organic Functional Molecules, Ministry of Education & College of Chemistry & Chemical Engineering, Hubei University, Wuhan 430062 (China); Tang, Bin, E-mail: bin.tang@deakin.edu.au [National Engineering Laboratory for Advanced Yarn and Fabric Formation and Clean Production, Wuhan Textile University, Wuhan 430073 (China); Institute for Frontier Materials, Deakin University, Geelong, Victoria 3216 (Australia); Zeng, Tian; Li, Yaling [Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials & Key Laboratory for the Synthesis and Application of Organic Functional Molecules, Ministry of Education & College of Chemistry & Chemical Engineering, Hubei University, Wuhan 430062 (China); Li, Jingliang [Institute for Frontier Materials, Deakin University, Geelong, Victoria 3216 (Australia); Ye, Yong, E-mail: yeyong@hubu.edu.cn [Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials & Key Laboratory for the Synthesis and Application of Organic Functional Molecules, Ministry of Education & College of Chemistry & Chemical Engineering, Hubei University, Wuhan 430062 (China); Wang, Xungai [National Engineering Laboratory for Advanced Yarn and Fabric Formation and Clean Production, Wuhan Textile University, Wuhan 430073 (China); Institute for Frontier Materials, Deakin University, Geelong, Victoria 3216 (Australia)

2016-11-15

Highlights: • Gold nanoparticles are in-situ synthesized on silk fabrics by heating. • Flexible silk fabrics with gold nanoparticles are used for surface-enhanced Raman scattering (SERS). • SERS activities of silk fabrics with different gold contents are investigated. - Abstract: Flexible SERS active substrates were prepared by modification of silk fabrics with gold nanoparticles. Gold nanoparticles were in-situ synthesized after heating the silk fabrics immersed in gold ion solution. Localized surface plasmon resonance (LSPR) properties of the treated silk fabrics varied as the concentration of gold ions changed, in relation to the morphologies of gold nanoparticles on silk. In addition, X-ray diffraction (XRD) was used to observe the structure of the gold nanoparticle treated silk fabrics. The SERS enhancement effect of the silk fabrics treated with gold nanoparticles was evaluated by collecting Raman signals of different concentrations of p-aminothiophenol (PATP), 4-mercaptopyridine (4-MPy) and crystal violet (CV) solutions. The results demonstrate that the silk fabrics corresponding to 0.3 and 0.4 mM of gold ions possess high SERS activity compared to the other treated fabrics. It is suggested that both the gold content and morphologies of gold nanoparticles dominate the SERS effect of the treated silk fabrics.

Cyanuric acid hydrolase from Azorhizobium caulinodans ORS 571: crystal structure and insights into a new class of Ser-Lys dyad proteins.

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Seunghee Cho

Full Text Available Cyanuric acid hydrolase (CAH catalyzes the hydrolytic ring-opening of cyanuric acid (2,4,6-trihydroxy-1,3,5-triazine, an intermediate in s-triazine bacterial degradation and a by-product from disinfection with trichloroisocyanuric acid. In the present study, an X-ray crystal structure of the CAH-barbituric acid inhibitor complex from Azorhizobium caulinodans ORS 571 has been determined at 2.7 Å resolution. The CAH protein fold consists of three structurally homologous domains forming a β-barrel-like structure with external α-helices that result in a three-fold symmetry, a dominant feature of the structure and active site that mirrors the three-fold symmetrical shape of the substrate cyanuric acid. The active site structure of CAH is similar to that of the recently determined AtzD with three pairs of active site Ser-Lys dyads. In order to determine the role of each Ser-Lys dyad in catalysis, a mutational study using a highly sensitive, enzyme-coupled assay was conducted. The 10⁹-fold loss of activity by the S226A mutant was at least ten times lower than that of the S79A and S333A mutants. In addition, bioinformatics analysis revealed the Ser226/Lys156 dyad as the only absolutely conserved dyad in the CAH/barbiturase family. These data suggest that Lys156 activates the Ser226 nucleophile which can then attack the substrate carbonyl. Our combination of structural, mutational, and bioinformatics analyses differentiates this study and provides experimental data for mechanistic insights into this unique protein family.

Recubrimiento por láser de aleaciones cuasicristalinas

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Audebert, F.

1998-04-01

Full Text Available Quasicrystals are a new class of ordenated structures with metaestable characteristics at room temperature. Quasicrystalline phases can be obtained by rapid quenching from the melt of some alloys. In general, quasicrystals present properties which make these alloys promising for wear and corrosion resistant coatings applications. During the last years, the development of quasicrystalline coatings by means of thermal spray techniques has been impulsed. However, no references have been found of their application by means of laser techniques. In this work four claddings of quasicrystalline compositions formed over aluminum substrate, produced by a continuos CO₂ laser using simultaneous powders mixture injection are presented. The claddings were characterized by X ray diffraction, scanning electron microscopy and Vickers microhardness.

Los cuasicristales constituyen un nuevo tipo de estructuras ordenadas con características metaestables a temperatura ambiente. En general, en determinadas aleaciones, pueden obtenerse por enfriamiento rápido desde el estado líquido. Han demostrado poseer buenas propiedades para su aplicación como recubrimientos resistentes al desgaste y a la corrosión. En este sentido, desde hace unos años, se ha impulsado el desarrollo de su aplicación mediante técnicas de thermal spray, aunque no se han encontrado referencias de su aplicación mediante técnicas de láser. En este trabajo, se presenta la formación de cuatro recubrimientos de aleaciones con composiciones cuasicristalinas sobre un sustrato de aluminio, utilizando un láser continuo de CO₂, con inyección simultánea del material en forma de mezcla de polvos. Los mismos fueron caracterizados por difracción de rayos X, microscopía electrónica de barrido y microdureza Vickers.

Reflexión crítica en torno al hecho religioso

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John Alexis Rengifo Carpintero

2015-07-01

Full Text Available El hecho religioso, como objeto de estudio, es un acontecimiento que ha de ser abordado desde distintos enfoques disciplinarios si se quiere adentrar en su comprensión más amplia. Por ello, este artículo es un bosquejo investigativo de tal hecho bajo el horizonte conceptual de su origen dogmático-teológico, el de su acción socio-cultural y el del marco de referencia reflexivo filosófico, horizontes que dan cuerpo, cada uno y en su orden, a un apartado, desde los cuales se piensa como acontecimiento que cumple una doble finalidad: la de sacar al hombre de su ser precario, su biología carencial; y la de mostrar que este siempre, en todo momento y lugar, se dirige al mismo fin, brindarle la esperanza al hombre de su propia trascendencia. Pero a un terrible costo, la pérdida del juicio crítico. Cada uno de estos horizontes de análisis da cuerpo a un apartado.

SERS substrates for in-situ biosensing (Conference Presentation)

Science.gov (United States)

Venugopalan, Priyamvada; Quilis, Nestor; Jakub, Dostalek; Wolfgang, Knoll

2017-06-01

Abstract: Recent years have seen a rapid progress in the field of surface-enhanced Raman spectroscopy (SERS) which is attributed to the thriving field of plasmonics [1]. SERS is a susceptible technique that can address basic scientific questions and technological problems. In both cases, it is highly dependent upon the plasmonic substrate, where excitation of the localized surface plasmon resonance enhances the vibrational scattering signal of the analyte molecules adsorbed on to the surface [2]. In this work, using finite difference time domain (FDTD) method we investigate the optical properties of plasmonic nanostructures with tuned plasmonic resonances as a function of dielectric environment and geometric parameters. An optimized geometry will be discussed based on the plasmonic resonant position and the SERS intensity. These SERS substrates will be employed for the detection of changes in conformation caused by interactions between an aptamer and analyte molecules. This will be done by using a microfluidic channel designed within the configuration of the lab-on-a-chip concept based on the intensity changes of the SERS signal. More efficient and reproducible results are obtained for such a quantitative measurement of analytes at low concentration levels. We will also demonstrate that the plasmonic substrates fabricated by top down approach such as e-beam lithography (EBL) and laser interference lithography (LIL) are highly reproducible, robust and can result in high electric field enhancement. Our results demonstrate the potential to use SERS substrates for highly sensitive detection schemes opening up the window for a wide range of applications including biomedical diagnostics, forensic investigation etc. Acknowledgement: This work was supported by the Austrian Science Fund (FWF), project NANOBIOSENSOR (I 2647). References: [1] J. N. Anker, W. P. Hall, O. Lyandres, N. C. Shah, J. Zhao and R. P. V. Duyne., " Biosensing with plasmonic nanosensors," Nature

Salvar al planeta

OpenAIRE

Thomas Sancton

2015-01-01

El desastre de Exxon Valdez en Canadá (1989)en que derramaron 262 mil barriles de petróleo en las aguas de Alaska cambió la conciencia de los norteamericanos para bien. Comienzan a preocuparse, les gusta ser ecologistas. Se espera que no sea moda o novelería y que asuman el liderazgo para salvar al planeta, pues la deforestación, el incremento de la población, la quema de combustibles fósiles, el calentamiento global, el agujero de ozono sobre la Antártida dejan intuir que la Tierra está en g...

SERS substrates fabricated using ceramic filters for the detection of bacteria

Science.gov (United States)

Mosier-Boss, P. A.; Sorensen, K. C.; George, R. D.; Obraztsova, A.

2016-01-01

SERS substrates were fabricated by filtering either Ag or Au colloidal particles onto rigid, ceramic filters - onto which suspensions of bacteria were then filtered. SERS spectra of the bacteria were obtained using a Raman spectrometer that has an 'orbital raster scan' capability. It was shown that bacteria samples prepared in this manner were uniformly distributed onto the surface of the SERS substrate. The effect of common buffer systems on the SERS spectra was investigated and the utility of using the SERS technique for speciation of bacteria was explored.

EFECTO DEL PRECALENTAMIENTO Y LA SEVERIDAD DE TEMPLE SOBRE LA RESISTENCIA AL DESGASTE ADHESIVO DEL ACERO AUSTENÍTICO AL MANGANESO

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OSCAR FABIÁN HIGUERA COBOS

2010-01-01

Full Text Available En este trabajo de investigación se estudió el efecto del precalentamiento y la severidad de temple sobre la resistencia al desgaste adhesivo del acero austenítico al manganeso ASTM A 128 grado C. El material se sometió a ciclos térmicos de temple y revenido con y sin precalentamiento con el fin de evaluar su influencia sobre la resistencia al desgaste. Posteriormente el material fue sometido a prueba según norma ASTM G83 y se determinó que el acero Austenítico al manganeso, es un material que presenta una microestructura metaestable en condiciones estables y no debe ser sometido a tratamiento térmico de revenido a altas temperaturas debido que favorece la descomposición de esta a ferrita (fase blanda de los acero y por ende disminuye su resistencia al desgaste.

Development of optimized nanogap plasmonic substrate for improved SERS enhancement

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Jayakumar Perumal

2017-05-01

Full Text Available SERS enhancement factor (EF of planar substrates depends on the size and shape of the fine nanostructure forming a defect free, well-arranged matrix. Nano-lithographic process is considered to be the most advanced methods employed for the fabrication SERS substrates. Nanostructured plasmonic substrates with nanogap (NG pattern often results in stable, efficient and reproducible SERS enhancement. For such substrates, NG and their diagonal length (DL need to be optimized. Theoretically smaller NGs (∼30-40 nm or smaller results in higher SERS enhancement. However, fabrication of NG substrates below such limit is a challenge even for the most advanced lithography process. In this context, herein, we report the optimization of fabrication process, where higher SERS enhancement can be realized from larger NGs substrates by optimizing their DL of nanostructures between the NGs. Based on simulation we could demonstrate that, by optimizing the DL, SERS enhancement from larger NG substrate such as 60 and 80 nm could be comparable to that of smaller (40nm NG substrates. We envision that this concept will open up new regime in the nanofabrication of practically feasible NG based plasmonic substrates with higher SERS enhancement. Initial results of our experiments are in close agreement with our simulated study.

Al clamor de les vuvuzeles

Directory of Open Access Journals (Sweden)

Javier Olivera Betrán

2010-09-01

Full Text Available El Mundial de Futbol de Sud-àfrica ha situat l’Àfrica al mapa mundial i ha mostrat al món el triomf de l’estil de futbol d’Espanya basat en la col·lectivitat, l’esperit d’equip, la humilitat, la cohesió interna i el joc bonic. L’organització africana, seriosa i eficaç, ha sabut mobilitzar i il·lusionar la població del país que ha participat en el mundial des de l’orgull de ser africà, amb l’esperit alegre, festiu i també reivindicatiu de la gent de l’Àfrica. Aquest esdeveniment suposa el llançament de la marca “Sud-àfrica” al món amb un avís clar d’optar a l’organització d’uns primers Jocs Olímpics a Àfrica (potser els de 2020. S’obre una finestra d’esperança al segle xxi per al continent perdut de la mà de l’esport espectacle tan universal, massiu, emocional i mercantil que també es juga a la canxa de la política i de l’economia.

Analytical characterization using surface-enhanced Raman scattering (SERS) and microfluidic sampling

International Nuclear Information System (INIS)

Wang, Chao; Yu, Chenxu

2015-01-01

With the rapid development of analytical techniques, it has become much easier to detect chemical and biological analytes, even at very low detection limits. In recent years, techniques based on vibrational spectroscopy, such as surface enhanced Raman spectroscopy (SERS), have been developed for non-destructive detection of pathogenic microorganisms. SERS is a highly sensitive analytical tool that can be used to characterize chemical and biological analytes interacting with SERS-active substrates. However, it has always been a challenge to obtain consistent and reproducible SERS spectroscopic results at complicated experimental conditions. Microfluidics, a tool for highly precise manipulation of small volume liquid samples, can be used to overcome the major drawbacks of SERS-based techniques. High reproducibility of SERS measurement could be obtained in continuous flow generated inside microfluidic devices. This article provides a thorough review of the principles, concepts and methods of SERS-microfluidic platforms, and the applications of such platforms in trace analysis of chemical and biological analytes. (topical review)

TLC-SERS Plates with a Built-In SERS Layer Consisting of Cap-Shaped Noble Metal Nanoparticles Intended for Environmental Monitoring and Food Safety Assurance

Directory of Open Access Journals (Sweden)

H. Takei

2015-01-01

Full Text Available We report on a thin layer chromatograph (TLC with a built-in surface enhanced Raman scattering (SERS layer for in-situ identification of chemical species separated by TLC. Our goal is to monitor mixture samples or diluted target molecules suspended in a host material, as happens often in environmental monitoring or detection of food additives. We demonstrate that the TLC-SERS can separate mixture samples and provide in-situ SERS spectra. One sample investigated was a mixture consisting of equal portions of Raman-active chemical species, rhodamine 6 G (R6G, crystal violet (CV, and 1,2-di(4-pyridylethylene (BPE. The three components could be separated and their SERS spectra were obtained from different locations. Another sample was skim milk with a trace amount of melamine. Without development, no characteristic peaks were observed, but after development, a peak was observed at 694 cm−1. Unlike previous TLC-SERS whereby noble metal nanoparticles are added after development of a sample, having a built-in SERS layer greatly facilitates analysis as well as maintaining high uniformity of noble metal nanoparticles.

SERS Engineering Collaboration

Science.gov (United States)

2012-06-01

laser beam. In the second approach, a pulsed laser was used to texture a silicon wafer to form sharp features. Silver was evaporated onto the wafer...orders of magnitude larger than that measured on a gold nanoparticle array on a glass substrate. The largest SERS enhancement for a silver device was...surface plasmons," Yizhuo Chu and Kenneth B. Crozier, Optics Letters vol. 34, 244 (2009) K3. "Gold nanorings as substrates for surface-enhanced Raman

CisSERS: Customizable In Silico Sequence Evaluation for Restriction Sites.

Science.gov (United States)

Sharpe, Richard M; Koepke, Tyson; Harper, Artemus; Grimes, John; Galli, Marco; Satoh-Cruz, Mio; Kalyanaraman, Ananth; Evans, Katherine; Kramer, David; Dhingra, Amit

2016-01-01

High-throughput sequencing continues to produce an immense volume of information that is processed and assembled into mature sequence data. Data analysis tools are urgently needed that leverage the embedded DNA sequence polymorphisms and consequent changes to restriction sites or sequence motifs in a high-throughput manner to enable biological experimentation. CisSERS was developed as a standalone open source tool to analyze sequence datasets and provide biologists with individual or comparative genome organization information in terms of presence and frequency of patterns or motifs such as restriction enzymes. Predicted agarose gel visualization of the custom analyses results was also integrated to enhance the usefulness of the software. CisSERS offers several novel functionalities, such as handling of large and multiple datasets in parallel, multiple restriction enzyme site detection and custom motif detection features, which are seamlessly integrated with real time agarose gel visualization. Using a simple fasta-formatted file as input, CisSERS utilizes the REBASE enzyme database. Results from CisSERS enable the user to make decisions for designing genotyping by sequencing experiments, reduced representation sequencing, 3'UTR sequencing, and cleaved amplified polymorphic sequence (CAPS) molecular markers for large sample sets. CisSERS is a java based graphical user interface built around a perl backbone. Several of the applications of CisSERS including CAPS molecular marker development were successfully validated using wet-lab experimentation. Here, we present the tool CisSERS and results from in-silico and corresponding wet-lab analyses demonstrating that CisSERS is a technology platform solution that facilitates efficient data utilization in genomics and genetics studies.

Incompatibilidade física de misturas entre herbicidas e inseticidas Physical incompatibility of herbicide and insecticide mixtures

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F.A. Petter

2012-06-01

Full Text Available Objetivou-se, com este trabalho, avaliar a interação física entre misturas em tanque de diferentes classes de defensivos agrícolas. O experimento foi conduzido no laboratório de Química da Universidade do Estado de Mato Grosso, no período de junho a agosto de 2010. Os tratamentos foram constituídos pelas misturas de seis herbicidas (glyphosate SC, glyphosate WG, lactofen CE, fomesafen SC, haloxifop-R CE e fluazifop-pbutil EW com seis inseticidas (methomyl CS, clorpirifós CE, teflubenzuron SC, triflumuron SC, cipermetrina CE e tiametoxam + lambda-cialotrina SC na ausência e presença de dois redutores de pH (ácido pirolenhoso e ácido bórico, com quatro repetições. Utilizou-se escala de 1 a 5, visando avaliar o grau de incompatibilidade, em que 1 é a separação imediata da mistura e recomenda-se não aplicar e 5 é a homogeneidade das misturas. As maiores incompatibilidades físicas nas misturas de herbicidas e inseticidas foram observadas na presença dos herbicidas glyphosate na formulação WG e lactofen CE. O ácido pirolenhoso e o ácido bórico demonstraram ser boas alternativas, como redutores de pH, no preparo de calda de pulverização com misturas de herbicidas e inseticidas. Devem-se evitar misturas em tanque de glyphosate na formulação SC + clorpirifós CE e lactofen CE + clorpirifós CE.The objective ofthis study was to evaluate the physical interaction between simulated tank mixtures of different classes of pesticides. The experiment was conducted at the Chemistry Laboratory of the University of Mato Grosso, Brazil, from June to August 2010. The treatments consisted of mixtures of six herbicides (glyphosate SC, glyphosate WG, lactofen CE, fomesafen SC, haloxifop-R CE, and fluazifop-p-butyl EW with six types of insecticide (methomyl CS, clorpirifos CE, teflubenzuron SC, triflumuron SC, cipermetrin CE, and tiametoxam + lambda-cialotrin SC in the absence and presence oftwo pH reducers (pyroligneous acid and boric acid

por láser

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Mayra Garcimuño

2013-01-01

Full Text Available En el presente trabajo, la técnica Espectroscopia de plasmas producidos por láser (Laser-induced breakdown spectroscopy –LIBS– se aplicó a la determinación cuan- titativa de Na en agua natural dulce, de interés en agricultura para el estudio de la alcalinidad de aguas de regadío. Para efectuar el análisis, se prepararon soluciones con concentraciones conocidas del analito, se mezclaron con óxido de calcio y se compactaron en pastillas sólidas. Los plasmas se produjeron en aire a presión atmos- férica utilizando un láser pulsado Nd:YAG. Se construyó una curva de calibración y se calculó el límite de detección. Se analizaron muestras de agua natural y los resultados se compararon con los obtenidos mediante espectroscopia de absorción atómica. Se demostró la factibilidad del método para la determinación de Na en agua natural dulce.

Historia de una coma. Gadamer y el sentido del ser

OpenAIRE

Vattimo, Gianni

2005-01-01

A partir de la doble posibilidad de traducir en las lenguas románicas la expresión gadameriana «Sein, das verstanden werden kann, ist Sprache» como «El ser, que puede ser comprendido, es lenguaje» o como «El ser que puede ser comprendido es lenguaje», se consideran las importantes repercusiones ontológicas que tendría una interpretación más moderada (y más habitual) de ese enunciado (la primera exhibida), o una lectura más radical y nihilista (la que aquí se defiende) del mismo (la ...

Superhydrophobic SERS substrates based on silicon hierarchical nanostructures

Science.gov (United States)

Chen, Xuexian; Wen, Jinxiu; Zhou, Jianhua; Zheng, Zebo; An, Di; Wang, Hao; Xie, Weiguang; Zhan, Runze; Xu, Ningsheng; Chen, Jun; She, Juncong; Chen, Huanjun; Deng, Shaozhi

2018-02-01

Silicon nanostructures have been cultivated as promising surface enhanced Raman scattering (SERS) substrates in terms of their low-loss optical resonance modes, facile functionalization, and compatibility with today’s state-of-the-art CMOS techniques. However, unlike their plasmonic counterparts, the electromagnetic field enhancements induced by silicon nanostructures are relatively small, which restrict their SERS sensing limit to around 10-7 M. To tackle this problem, we propose here a strategy for improving the SERS performance of silicon nanostructures by constructing silicon hierarchical nanostructures with a superhydrophobic surface. The hierarchical nanostructures are binary structures consisted of silicon nanowires (NWs) grown on micropyramids (MPs). After being modified with perfluorooctyltriethoxysilane (PFOT), the nanostructure surface shows a stable superhydrophobicity with a high contact angle of ˜160°. The substrate can allow for concentrating diluted analyte solutions into a specific area during the evaporation of the liquid droplet, whereby the analytes are aggregated into a small volume and can be easily detected by the silicon nanostructure SERS substrate. The analyte molecules (methylene blue: MB) enriched from an aqueous solution lower than 10-8 M can be readily detected. Such a detection limit is ˜100-fold lower than the conventional SERS substrates made of silicon nanostructures. Additionally, the detection limit can be further improved by functionalizing gold nanoparticles onto silicon hierarchical nanostructures, whereby the superhydrophobic characteristics and plasmonic field enhancements can be combined synergistically to give a detection limit down to ˜10-11 M. A gold nanoparticle-functionalized superhydrophobic substrate was employed to detect the spiked melamine in liquid milk. The results showed that the detection limit can be as low as 10-5 M, highlighting the potential of the proposed superhydrophobic SERS substrate in

Empleo de la terapia láser en la reparación ósea periapical

Directory of Open Access Journals (Sweden)

MARÍA I. GARRIGÓ ANDREU

1997-06-01

Full Text Available El efecto bioestimulante de la radiación láser de baja potencia en el tejido óseo, se ha comprobado en cultivos de células y animales de experimentación. El objetivo de esta investigación fue evaluar dicho efecto en la reparación ósea periapical. Se atendieron 40 pacientes que presentaban procesos periapicales crónicos, a los que se les realizó tratamiento pulpo radicular y láser. Para la terapia láser, se útilizó la técnica puntual en el área lesionada y laserpuntura, con depósitos energéticos de 15 J/cm² y 7 J/cm², respectivamente. Los resultados obtenidos demuestran que existió aceleración en los procesos de reparación ósea periapical al utilizar la terapia láser, pues en el 67,5 % de los pacientes atendidos, la misma ocurrió en un período menor a 6 meses después de iniciado el tratamiento.The biostimulant effect of low energy laser radiation on the bone tissue has been tested in cell cultures and experimental animals. The objective of our investigation was to evaluate this effect on the periapical bone reparation. 40 patients received attention and underwent radicular, pulpar, and laser treatment. The acupuncture points technique in the injured area and the laserpuncture were used as part of the laser terapy with energetic depots of 15 J/cm² and 7 J/cm², respectively. The results show that the processes of periapical bone reparation were accelerated, since in 67.5 % of these patients it took place in less than 6 months.

De GPS al mapa

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Esteban Dörries

2016-03-01

Full Text Available Las coordenadas Lambert obtenidas a partir de mediciones con equipos GPS de mano, llamados a veces navegadores, en ciertos casos confunden al usuario, por diferir claramente de su posición real al ser graficadas en un mapa del Instituto Geográfico Nacional (IGN: Esto puede resolverse con suficiente exactitud mediante una transformación de Molodensky, seguida de la correspondiente proyección cartográfica. Sin embargo, los tres parámetros necesarios para la transformación, supuestamente válidos para Costa Rica, se encuentran en muchas variantes y producen obviamente resultados diferentes. En este trabajo se analizan los fundamentos del problema y sus posibles soluciones, culminando con un estudio comparativo de ocho casos, que permite seleccionar los valores más adecuados para los parámetros.

Normal Raman and SERS spectroscopy of the vitamin E

International Nuclear Information System (INIS)

Cai Tiantian; Gu Huaimin; Yuan Xiaojuan; Liu Fangfang

2011-01-01

In this study, surface-enhanced Raman scattering(SERS)spectra of vitamin E were obtained on colloidal silver(Ag). Alpha-(-) tocopherol which is the only form that is recognized to meet human requirements was selected to study. The analytes (±)- -tocopherol were dissolved in chloroform (CHCl 3 ) and the silver colloid was poured into the compound. Silver colloid was reduced by hydroxylamine hydrochloride. The analytes were the supernatant after standing the mixture for the reason that chloroform have no signals in surface-enhanced Raman scattering in the Ag colloid, and it would not affect the determination of the (±)- -tocopherol. The Normal Raman and SERS spectrum of Vitamin E were contrastively studied to realize how the vitamin E stuck to the silver nanoparticles. The results show the fat-soluble substances can be analysed by SERS. The spectra indicate that the molecules are adsorbed on the surface through the COO- groups by the simultaneous involvement of a and -type coordination. These results suggest some important criteria for consideration in SERS measurements and also provide important insights into the problem of predicting SERS activities for different fat-soluble substances.

Normal Raman and SERS spectroscopy of the vitamin E

Energy Technology Data Exchange (ETDEWEB)

Cai Tiantian; Gu Huaimin; Yuan Xiaojuan; Liu Fangfang, E-mail: guhm@scnu.edu.cn [MOE Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, 510631, Guangzhou (China)

2011-01-01

In this study, surface-enhanced Raman scattering(SERS)spectra of vitamin E were obtained on colloidal silver(Ag). Alpha-(-) tocopherol which is the only form that is recognized to meet human requirements was selected to study. The analytes ({+-})- -tocopherol were dissolved in chloroform (CHCl{sub 3}) and the silver colloid was poured into the compound. Silver colloid was reduced by hydroxylamine hydrochloride. The analytes were the supernatant after standing the mixture for the reason that chloroform have no signals in surface-enhanced Raman scattering in the Ag colloid, and it would not affect the determination of the ({+-})- -tocopherol. The Normal Raman and SERS spectrum of Vitamin E were contrastively studied to realize how the vitamin E stuck to the silver nanoparticles. The results show the fat-soluble substances can be analysed by SERS. The spectra indicate that the molecules are adsorbed on the surface through the COO- groups by the simultaneous involvement of a and -type coordination. These results suggest some important criteria for consideration in SERS measurements and also provide important insights into the problem of predicting SERS activities for different fat-soluble substances.

CisSERS: Customizable In Silico Sequence Evaluation for Restriction Sites.

Directory of Open Access Journals (Sweden)

Richard M Sharpe

Full Text Available High-throughput sequencing continues to produce an immense volume of information that is processed and assembled into mature sequence data. Data analysis tools are urgently needed that leverage the embedded DNA sequence polymorphisms and consequent changes to restriction sites or sequence motifs in a high-throughput manner to enable biological experimentation. CisSERS was developed as a standalone open source tool to analyze sequence datasets and provide biologists with individual or comparative genome organization information in terms of presence and frequency of patterns or motifs such as restriction enzymes. Predicted agarose gel visualization of the custom analyses results was also integrated to enhance the usefulness of the software. CisSERS offers several novel functionalities, such as handling of large and multiple datasets in parallel, multiple restriction enzyme site detection and custom motif detection features, which are seamlessly integrated with real time agarose gel visualization. Using a simple fasta-formatted file as input, CisSERS utilizes the REBASE enzyme database. Results from CisSERS enable the user to make decisions for designing genotyping by sequencing experiments, reduced representation sequencing, 3'UTR sequencing, and cleaved amplified polymorphic sequence (CAPS molecular markers for large sample sets. CisSERS is a java based graphical user interface built around a perl backbone. Several of the applications of CisSERS including CAPS molecular marker development were successfully validated using wet-lab experimentation. Here, we present the tool CisSERS and results from in-silico and corresponding wet-lab analyses demonstrating that CisSERS is a technology platform solution that facilitates efficient data utilization in genomics and genetics studies.

Enhancing SERS by Means of Supramolecular Charge Transfer

Science.gov (United States)

Wong, Eric; Flood, Amar; Morales, Alfredo

2009-01-01

In a proposed method of sensing small quantities of molecules of interest, surface enhanced Raman scattering (SERS) spectroscopy would be further enhanced by means of intermolecular or supramolecular charge transfer. There is a very large potential market for sensors based on this method for rapid detection of chemical and biological hazards. In SERS, the Raman signals (vibrational spectra) of target molecules become enhanced by factors of the order of 108 when those molecules are in the vicinities of nanostructured substrate surfaces that have been engineered to have plasmon resonances that enhance local electric fields. SERS, as reported in several prior NASA Tech Briefs articles and elsewhere, has remained a research tool and has not yet been developed into a practical technique for sensing of target molecules: this is because the short range (5 to 20 nm) of the field enhancement necessitates engineering of receptor molecules to attract target molecules to the nanostructured substrate surfaces and to enable reliable identification of the target molecules in the presence of interferants. Intermolecular charge-transfer complexes have been used in fluorescence-, photoluminescence-, and electrochemistry-based techniques for sensing target molecules, but, until now, have not been considered for use in SERS-based sensing. The basic idea of the proposed method is to engineer receptor molecules that would be attached to nanostructured SERS substrates and that would interact with the target molecules to form receptor-target supramolecular charge-transfer complexes wherein the charge transfer could be photoexcited.

Nanosphere Lithography on Fiber: Towards Engineered Lab-On-Fiber SERS Optrodes

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Giuseppe Quero

2018-02-01

Full Text Available In this paper we report on the engineering of repeatable surface enhanced Raman scattering (SERS optical fiber sensor devices (optrodes, as realized through nanosphere lithography. The Lab-on-Fiber SERS optrode consists of polystyrene nanospheres in a close-packed arrays configuration covered by a thin film of gold on the optical fiber tip. The SERS surfaces were fabricated by using a nanosphere lithography approach that is already demonstrated as able to produce highly repeatable patterns on the fiber tip. In order to engineer and optimize the SERS probes, we first evaluated and compared the SERS performances in terms of Enhancement Factor (EF pertaining to different patterns with different nanosphere diameters and gold thicknesses. To this aim, the EF of SERS surfaces with a pitch of 500, 750 and 1000 nm, and gold films of 20, 30 and 40 nm have been retrieved, adopting the SERS signal of a monolayer of biphenyl-4-thiol (BPT as a reliable benchmark. The analysis allowed us to identify of the most promising SERS platform: for the samples with nanospheres diameter of 500 nm and gold thickness of 30 nm, we measured values of EF of 4 × 105, which is comparable with state-of-the-art SERS EF achievable with highly performing colloidal gold nanoparticles. The reproducibility of the SERS enhancement was thoroughly evaluated. In particular, the SERS intensity revealed intra-sample (i.e., between different spatial regions of a selected substrate and inter-sample (i.e., between regions of different substrates repeatability, with a relative standard deviation lower than 9 and 15%, respectively. Finally, in order to determine the most suitable optical fiber probe, in terms of excitation/collection efficiency and Raman background, we selected several commercially available optical fibers and tested them with a BPT solution used as benchmark. A fiber probe with a pure silica core of 200 µm diameter and high numerical aperture (i.e., 0.5 was found to be the

COSTA RICA: ELEMENTOS PARA UNA ESTRATEGIA DE POSICIONAMIENTO HACIA EL DESARROLLO (De cara al TLC y al neoliberalismo

Directory of Open Access Journals (Sweden)

Henry Mora Jiménez

2006-07-01

Full Text Available Costa Rica, económicamente hablando, no es un país pequeño, es un país diminuto. Por eso, toda estrategia de desarrollo económico1 que se enmarque en un determinado proyecto político de país, debe ser una estrategia de desarrollo “hacia fuera”, es decir, en amplia interacción (comercial, financiera, tecnológica y de cooperación, con otras economías nacionales, regionales y al nivel mundial. En este plano, y de cara a la formulación de una estrategia de desarrollo, no hay otra alternativa.“Desde adentro”, porque esa integración (inserción debe sustentarse en un desarrollo articulado de la economía nacional y de su tejido empresarial y productivo. Articulación significa,en este nivel, generación, apropiación y (redistribución interna de un alto valor agregado, con la creación de encadenamientos productivos y de empleos de calidad; muy al contrario de losenclaves de plantación, industriales y de exportación que han sido la norma durante toda nuestra historia como país formalmente independiente (modelo agroexportador, modelo desustitución de importaciones, modelo importadormaquilador-exportador.“Desde abajo”, porque tiene que traducirse en un desarrollo no excluyente (desarrollo inclusivo, en la construcción de una sociedad donde quepamos todos y todas, sin dejar por fuera en esta inclusión a la naturaleza (desarrollo ambientalmentesustentable. No se trata de crecer para luego distribuir, sino que la propia racionalidad económica del proyecto transformador debe ser inclusiva (ser humano y naturaleza.

IR, Raman and SERS studies of methyl salicylate

Science.gov (United States)

Varghese, Hema Tresa; Yohannan Panicker, C.; Philip, Daizy; Mannekutla, James R.; Inamdar, S. R.

2007-04-01

The IR and Raman spectra of methyl salicylate (MS) were recorded and analysed. Surface enhanced Raman scattering (SERS) spectrum was recorded in silver colloid. The vibrational wave numbers of the compound have been computed using the Hartree-Fock/6-31G * basis and compared with the experimental values. SERS studies suggest a flat orientation of the molecule at the metal surface.

Implicações para o cuidar de enfermagem a partir de percepções do ser portador de neurofibromatose

Directory of Open Access Journals (Sweden)

Claudia de Carvalho-Dantas

2009-01-01

Full Text Available La neurofibromatosis 1 es un síndrome genético autosómico muy frecuente en el ser humano. Se caracteriza por el crecimiento de tumores benignos de los nervios; puede presentarse en cualquier parte del cuerpo. Objetivos: identificar la percepción del paciente con neurofibromatosis al ser portador de esta enfermedad; analizar los factores que intervienen en su vida personal o profesional con base en sus relatos; discutir las implicaciones de esas percepciones en la asistencia de enfermería. Esta investigación, llevada a cabo en la Unidad de Apoyo Mutuo a la Neurofibromatosis -vinculada al Centro Nacional de Fibromatosis en Río de Janeiro-, es cualitativa y descriptivo-exploratoria. La recolección de datos se realizó en 2008 mediante una entrevista semiestructurada a 8 pacientes mayores de 18 años. Del análisis surgieron una categoría principal y 5 subcategorías. Se concluyó que las percepciones originan preocupaciones cotidianas de corte social, emocional, estético, físico y educativo que conducen al portador a experimentar el conflicto de la exclusión interna y de la sociedad, debido a la falta de información respecto de su enfermedad. Se sugiere realizar otras investigaciones e invertir en procesos educativo-informativos para los portadores y la sociedad, así como preparar profesionales de salud que puedan brindar orientaciones y diagnósticos correctos, lo cual redunda en el mejoramiento de la calidad de vida de los portadores y ayuda a integrarlos en la sociedad.

Au coated PS nanopillars as a highly ordered and reproducible SERS substrate

Science.gov (United States)

Kim, Yong-Tae; Schilling, Joerg; Schweizer, Stefan L.; Sauer, Guido; Wehrspohn, Ralf B.

2017-07-01

Noble metal nanostructures with nanometer gap size provide strong surface-enhanced Raman scattering (SERS) which can be used to detect trace amounts of chemical and biological molecules. Although several approaches were reported to obtain active SERS substrates, it still remains a challenge to fabricate SERS substrates with high sensitivity and reproducibility using low-cost techniques. In this article, we report on the fabrication of Au sputtered PS nanopillars based on a template synthetic method as highly ordered and reproducible SERS substrates. The SERS substrates are fabricated by anodic aluminum oxide (AAO) template-assisted infiltration of polystyrene (PS) resulting in hemispherical structures, and a following Au sputtering process. The optimum gap size between adjacent PS nanopillars and thickness of the Au layers for high SERS sensitivity are investigated. Using the Au sputtered PS nanopillars as an active SERS substrate, the Raman signal of 4-methylbenzenethiol (4-MBT) with a concentration down to 10-9 M is identified with good signal reproducibility, showing great potential as promising tool for SERS-based detection.

Obtención tecnológica de mullita a partir de arcillas y caolines refractarios argentinos, y alúmina calcinada o alúminas hidratadas

OpenAIRE

Moreno Erazo, Ángela Ximena

2014-01-01

En el presente trabajo de investigación se busca mostrar la posibilidad de producir mullita de alta calidad en Argentina, utilizando materias primas nacionales y comodities internacionales con el objetivo de obtener un material confiable, de excelentes propiedades en el uso y con un costo razonable para ser incorporada en la producción de refractarios. El estudio de la obtención tecnológica de mullita a partir de arcillas y caolines refractarios argentinos, y alúmina calcinada ó alú...

Salvar al planeta

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Thomas Sancton

2015-01-01

Full Text Available El desastre de Exxon Valdez en Canadá (1989en que derramaron 262 mil barriles de petróleo en las aguas de Alaska cambió la conciencia de los norteamericanos para bien. Comienzan a preocuparse, les gusta ser ecologistas. Se espera que no sea moda o novelería y que asuman el liderazgo para salvar al planeta, pues la deforestación, el incremento de la población, la quema de combustibles fósiles, el calentamiento global, el agujero de ozono sobre la Antártida dejan intuir que la Tierra está en grave peligro. Se recomienda entonces optar por un desarrollo sustentable.

Fabrication of Semiconductor ZnO Nanostructures for Versatile SERS Application

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Lili Yang

2017-11-01

Full Text Available Since the initial discovery of surface-enhanced Raman scattering (SERS in the 1970s, it has exhibited a huge potential application in many fields due to its outstanding advantages. Since the ultra-sensitive noble metallic nanostructures have increasingly exposed themselves as having some problems during application, semiconductors have been gradually exploited as one of the critical SERS substrate materials due to their distinctive advantages when compared with noble metals. ZnO is one of the most representative metallic oxide semiconductors with an abundant reserve, various and cost-effective fabrication techniques, as well as special physical and chemical properties. Thanks to the varied morphologies, size-dependent exciton, good chemical stability, a tunable band gap, carrier concentration, and stoichiometry, ZnO nanostructures have the potential to be exploited as SERS substrates. Moreover, other distinctive properties possessed by ZnO such as biocompatibility, photocatcalysis and self-cleaning, and gas- and chemo-sensitivity can be synergistically integrated and exerted with SERS activity to realize the multifunctional potential of ZnO substrates. In this review, we discuss the inevitable development trend of exploiting the potential semiconductor ZnO as a SERS substrate. After clarifying the root cause of the great disparity between the enhancement factor (EF of noble metals and that of ZnO nanostructures, two specific methods are put forward to improve the SERS activity of ZnO, namely: elemental doping and combination of ZnO with noble metals. Then, we introduce a distinctive advantage of ZnO as SERS substrate and illustrate the necessity of reporting a meaningful average EF. We also summarize some fabrication methods for ZnO nanostructures with varied dimensions (0–3 dimensions. Finally, we present an overview of ZnO nanostructures for the versatile SERS application.

Comparison of time-gated surface-enhanced Raman spectroscopy (TG-SERS) and classical SERS based monitoring of Escherichia coli cultivation samples.

Science.gov (United States)

Kögler, Martin; Paul, Andrea; Anane, Emmanuel; Birkholz, Mario; Bunker, Alex; Viitala, Tapani; Maiwald, Michael; Junne, Stefan; Neubauer, Peter

2018-06-08

The application of Raman spectroscopy as a monitoring technique for bioprocesses is severely limited by a large background signal originating from fluorescing compounds in the culture media. Here we compare time-gated Raman (TG-Raman)-, continuous wave NIR-process Raman (NIR-Raman) and continuous wave micro-Raman (micro-Raman) approaches in combination with surface enhanced Raman spectroscopy (SERS) for their potential to overcome this limit. For that purpose, we monitored metabolite concentrations of Escherichia coli bioreactor cultivations in cell-free supernatant samples. We investigated concentration transients of glucose, acetate, AMP and cAMP at alternating substrate availability, from deficiency to excess. Raman and SERS signals were compared to off-line metabolite analysis of carbohydrates, carboxylic acids and nucleotides. Results demonstrate that SERS, in almost all cases, led to a higher number of identifiable signals and better resolved spectra. Spectra derived from the TG-Raman were comparable to those of micro-Raman resulting in well-discernable Raman peaks, which allowed for the identification of a higher number of compounds. In contrast, NIR-Raman provided a superior performance for the quantitative evaluation of analytes, both with and without SERS nanoparticles when using multivariate data analysis. This article is protected by copyright. All rights reserved. © 2018 American Institute of Chemical Engineers.

SERS sensors for DVD platform

DEFF Research Database (Denmark)

Brøgger, Anna Line

This Ph.D. thesis explores the engineering of a portable sensor system for detection of rare and small molecules. The Ph.D. project is part of the research project 'Multi-Sensor DVD platform' (MUSE), aiming to integrate different sensors on a rotating disc. The sensors are chosen to complement each...... other, creating more reliable and stable results for the end user. The rotating disc comprises microfluidic channels, which can be utilized for handling and manipulating liquid samples such as blood or water. The focus of this Ph.D. thesis, is on the integration of one specific sensor on a rotating disc....... The sensor is based upon surface enhanced Raman spectroscopy (SERS), which detects molecular vibrations. The aim of this thesis is to cover the different aspects of the sensor system. SERS substrates, consisting of nanopillars with gold or silver caps on top, have been fabricated by standard micro and nano...

A Ag synchronously deposited and doped TiO2 hybrid as an ultrasensitive SERS substrate: a multifunctional platform for SERS detection and photocatalytic degradation.

Science.gov (United States)

Yang, Libin; Sang, Qinqin; Du, Juan; Yang, Ming; Li, Xiuling; Shen, Yu; Han, Xiaoxia; Jiang, Xin; Zhao, Bing

2018-06-06

Ag simultaneously deposited and doped TiO2 (Ag-TiO2) hybrid nanoparticles (NPs) were prepared via a sol-hydrothermal method, as both a sensitive surface-enhanced Raman scattering (SERS) substrate and a superior photocatalyst for the first time. Ag-TiO2 hybrid NPs exhibit excellent SERS performance for several probe molecules and the enhancement factor is calculated to be 1.86 × 105. The detection limit of the 4-mercaptobenzoic acid (4-MBA) probe on the Ag-TiO2 substrate is 1 × 10-9 mol L-1, which is four orders of magnitude lower than that on pure TiO2 as a consequence of the synergistic effects of TiO2 and Ag. This is the highest SERS sensitivity among the reported semiconductor substrates and even comparable to noble metal substrates, and a SERS enhancement mechanism from the synergistic contribution of the semiconductor and noble metal was proposed. And importantly, the Ag-TiO2 hybrid shows excellent photocatalytic degradation activity for the detected species under UV light irradiation at lower concentration conditions, even for the hard to degrade 4-MBA molecule. This makes the Ag-TiO2 hybrid promising as a dual-function platform for both highly sensitive SERS detection and photocatalytic degradation of a pollutant system. Moreover, it also proves that the Ag-TiO2 hybrid can serve as a promising recyclable SERS-active substrate by virtue of its photocatalytic self-cleaning properties for some specific applications, for instance comparative studies of different species on the same SERS platform, in addition to the economic benefit.

Entre contener y ser contenido

Directory of Open Access Journals (Sweden)

Jorge Morales Meneses

2016-08-01

Full Text Available El presente artículo propone una nueva manera de entender los elementos comunes en la formación y el hacer del diseño y de la arquitectura, posibilitando un pensar común y un coactuar en diversas escalas de intervención, necesarias para el manejo de la complejidad del paisaje contemporáneo. La convicción de un pensar común entre ambas disciplinas permite explorar un marco filosófico que incluye a pensadores tan trascendentales como Aristóteles, Kant y Heidegger, estableciendo un orden de pensamiento que los relaciona y sitúa. En momentos en que el territorio está siendo visible y negativamente afectado por elementos no pensados o que fueron imaginados separadamente, este artículo propone una mirada que le dé sentido de totalidad a las acciones del diseño y de la arquitectura, como elementos que permanentemente se contienen en otros de diferente escala, pero que siempre están vinculados. Reconocer el paisaje físico y mental, tangible e intangible que contiene al diseño y a la arquitectura contribuirá a establecer un marco de acción donde todos los elementos construidos por el ser humano puedan tener un rol específico y una escala asumida, e intercomprenderse para mejor utilización de los recursos, disminuir el impacto ambiental y contribuir a un orden social mejor interpretado por los objetos, espacios y sus representaciones.

La polémica sobre el ser en el Avicena y Averroes latinos

OpenAIRE

García-Marqués, A. (Alfonso)

1987-01-01

Fiosofía medieval; recepción del aristotelismo árabe en Occidente; metafísica; aristotelismo platonizante; esencia; universal; accidentalidad del ser; ser y esencia; ser veritativo y ser extramental; crítica de Averroes a Avicena.

Láser blando en puntos de acupuntura para el tratamiento de enfermedades bucales

Directory of Open Access Journals (Sweden)

CAROLINA J VALIENTE ZALDÍVAR

1997-06-01

Full Text Available La radiación láser blanda o de baja energía es de uso terapéutico, pues en ella predomina un efecto fotoquímico que desencadena, a nivel celular, reacciones bioquímicas, bioenergéticas y bioeléctricas, lo que produce en el organismo un efecto al reducir el dolor, el edema y estimular la regeneración tisular, según el depósito energético que se realice. Teniendo en cuenta que la medicina tradicional oriental considera que las enfermedades se producen a consecuencia de un desequilibrio energético en la zona lesionada, y por ende, en el organismo, se trata de lograr estabilidad de la energía estimulando puntos de acupuntura con agujas, moxa, presión digital, etcétera, y en la actualidad con láser (técnica denominada laserpuntura. Presentamos el procedimiento terapéutico para la utilización del láser blando sobre puntos de acupuntura y se hacen recomendaciones con puntos de acción general que apoyan este procedimiento.The soft or low energy laser radiation has a therapeutic use due to its photochemical effect that causes at the cellular level biochemical, bioenergetic and bioelectric reactions, which reduce pain and edema and stimulate tissue regeneration, according to the energetic depot made. Taking into account that the oriental traditional medicine considers that diseases result from an energetic unbalance in the injured zone, and consequently in the organism, energy stability in tried to be achieved by stimulating acupuncture points with needles, moxa, digital pressure, etc., and at present with laser (this technique is called laserpuncture. The therapeutical procedure for the utilization of soft laser on acupuncture points is presented, and recommendations with points of general action supporting this procedure are made.

Arcillas pilarizadas con Al-Fe y Al-Ce-Fe como sistema de postratamiento de las aguas residuales del beneficio húmedo del café

OpenAIRE

Peralta Ladino, Yury Marlén

2013-01-01

El efluente del sistema de tratamiento biológico de las aguas residuales del beneficio húmedo del café contiene compuestos no biodegradables, principalmente (ácidos hidroxicinámicos y clorogénicos) los cuales fueron identificados mediante análisis preliminares por LC-MS, por su toxicidad deben ser tratados antes de su descarga en las fuentes hídricas. El sistema Fenton heterogéneo empleando como soportes Al-Fe-PILC y Al-Ce-Fe-PILC (en polvo) mostró importantes conversión de compuestos fenólic...

Improving SERS uniformity by isolating hot spots in gold rod-in-shell nanoparticles

International Nuclear Information System (INIS)

Wang, Shanshan; Liu, Zhonghui; Bartic, Carmen; Xu, Hong; Ye, Jian

2016-01-01

Surface-enhanced Raman scattering (SERS) tags show ultrasensitivity and multiplexing abilities due to strong and characteristic Raman signals and therefore can be utilized as optical labeling agents similar to fluorescent dyes and quantum dots for biosensing and bioimaging. However, SERS tags have the difficulty to realize quantitative analysis due to the uniformity and reproducibility issue. In this work, we have reported on a new type of SERS tag called Au rod-in-shell (RIS) gap-enhanced Raman tag (GERT). With the high-resolution transmission electron microscopy (TEM) and optical absorbance measurements, we have demonstrated the subnanometer sized gap junctions inside the RIS GERTs. SERS measurements and FDTD calculations show that the core–shell subnanometer gap geometry in the RIS GERTs not only generates strong SERS hot spots but also isolates SERS hot spots by Au shells to avoid the influence when the particle aggregates form, therefore showing better SERS uniformity and stronger SERS intensity than normal Au nanorods. Those RIS NPs exhibit great potential as the labeling agents for SERS-based bioimaging and biosensing applications.

Improving SERS uniformity by isolating hot spots in gold rod-in-shell nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Wang, Shanshan; Liu, Zhonghui [Shanghai Jiao Tong University, School of Biomedical Engineering & Med-X Research Institute (China); Bartic, Carmen [KU Leuven, Department of Physics (Belgium); Xu, Hong, E-mail: xuhong@sjtu.edu.cn; Ye, Jian, E-mail: yejian78@sjtu.edu.cn [Shanghai Jiao Tong University, School of Biomedical Engineering & Med-X Research Institute (China)

2016-08-15

Surface-enhanced Raman scattering (SERS) tags show ultrasensitivity and multiplexing abilities due to strong and characteristic Raman signals and therefore can be utilized as optical labeling agents similar to fluorescent dyes and quantum dots for biosensing and bioimaging. However, SERS tags have the difficulty to realize quantitative analysis due to the uniformity and reproducibility issue. In this work, we have reported on a new type of SERS tag called Au rod-in-shell (RIS) gap-enhanced Raman tag (GERT). With the high-resolution transmission electron microscopy (TEM) and optical absorbance measurements, we have demonstrated the subnanometer sized gap junctions inside the RIS GERTs. SERS measurements and FDTD calculations show that the core–shell subnanometer gap geometry in the RIS GERTs not only generates strong SERS hot spots but also isolates SERS hot spots by Au shells to avoid the influence when the particle aggregates form, therefore showing better SERS uniformity and stronger SERS intensity than normal Au nanorods. Those RIS NPs exhibit great potential as the labeling agents for SERS-based bioimaging and biosensing applications.

Tuning SERS for living erythrocytes

DEFF Research Database (Denmark)

Brazhe, Nadezda; Parshina, E.Y.; Khabanova, V.V.

2013-01-01

Surface-enhanced Raman spectroscopy (SERS) is a unique technique to study submembrane hemoglobin (Hbsm) in erythrocytes. We report the detailed design of SERS experiments on living erythrocytes to estimate dependence of the enhancemen t factor for main Raman bands of Hbsm on silver nanoparticle (Ag......NP) properties. We demonstrate that the enhancement factor for 4/A1g, 10/B1g and A2g Raman bands of Hbsm varies from 105 to 107 under proposed experimental conditions with 473 nm laser excitation. For the first time we show that the enhancement of Raman scattering increases with the increase in the relative...... between small AgNPs and Hbsm and, consequently, leads to the higher enhancement of Raman scattering of Hbsm. The enhancement of higher wavenumber bands 10/B1g and A2g is more sensitive to AgNPs' size and the relative amount of small AgNPs than the enhancement of the lower wavenumber band 4/A1g. This can...

Potential application of SERS for arsenic speciation in biological matrices.

Science.gov (United States)

Yang, Mingwei; Matulis, Shannon; Boise, Lawrence H; McGoron, Anthony J; Cai, Yong

2017-08-01

Speciation of arsenic is usually carried out using chromatography-based methods coupled with spectroscopic determination; however, the inevitable procedures involving sample preparation and separation could potentially alter the integrity of the arsenic metabolites present in biological samples. Surface-enhanced Raman spectroscopy (SERS) could be a promising alternative for providing a reliable arsenic analysis under the influence of a cellular matrix. A method for arsenic speciation using SERS in cellular matrix was developed in this study and four arsenicals were selected, including arsenite (As III ), arsenate (As V ), monomethylarsonic acid (MMA V ) and dimethylarsinic acid (DMA V ). Silver nanoparticles in the form of colliodal suspension with different surface charges, i.e., coated with citrate (AgNPs-Citrate) and spermine (AgNPs-Spermine) were employed as SERS substrates. Adsorption of arsenicals on nanoparticles in colloidal suspensions and the cellular matrix and the pH, size, and zeta potential of the colloidal suspensions were investigated for a better understanding of the SERS signal response of arsenicals in the colloidal suspensions or under the influence of cellular matrix. Arsenicals showed substantially different SERS responses in the two colloidal suspensions, mainly because of the distinct difference in the interaction between the arsenicals and the nanoparticles. Arsenic speciation in cell lysate could be successfully carried out in AgNPs-Spermine suspension, while AgNPs-Citrate could not yield significant SERS signals under the experimental conditions. This study proved that AgNPs-Spermine colloidal suspension could be a promising SERS substrate for studying arsenic metabolism in a biological matrix, reducing the bias caused by traditional techniques that involve sample extraction and pretreatment.

Expansión estacionaria del plasma producido por un pulso de láser sobre una microesfera

OpenAIRE

Sanz Recio, Javier

1981-01-01

Para obtener energía de fusión mediante el láser, es necesario comprimir una microesfera a densidades muy altas (diez mil veces la densidad inicial), calentando al mismo tiempo un pequeño núcleo central del blanco a temperaturas del orden de 10 KeV. El problema queda dividido en dos partes bien diferenciadas cuando existe una superficie de ablación que separa el problema interior que es no estacionario y el problema exterior,, el cual se puede tomar cuasi estacionario si la densidad crítica d...

Correlative SEM SERS for quantitative analysis of dimer nanoparticles.

Science.gov (United States)

Timmermans, F J; Lenferink, A T M; van Wolferen, H A G M; Otto, C

2016-11-14

A Raman microscope integrated with a scanning electron microscope was used to investigate plasmonic structures by correlative SEM-SERS analysis. The integrated Raman-SEM microscope combines high-resolution electron microscopy information with SERS signal enhancement from selected nanostructures with adsorbed Raman reporter molecules. Correlative analysis is performed for dimers of two gold nanospheres. Dimers were selected on the basis of SEM images from multi aggregate samples. The effect of the orientation of the dimer with respect to the polarization state of the laser light and the effect of the particle gap size on the Raman signal intensity is observed. Additionally, calculations are performed to simulate the electric near field enhancement. These simulations are based on the morphologies observed by electron microscopy. In this way the experiments are compared with the enhancement factor calculated with near field simulations and are subsequently used to quantify the SERS enhancement factor. Large differences between experimentally observed and calculated enhancement factors are regularly detected, a phenomenon caused by nanoscale differences between the real and 'simplified' simulated structures. Quantitative SERS experiments reveal the structure induced enhancement factor, ranging from ∼200 to ∼20 000, averaged over the full nanostructure surface. The results demonstrate correlative Raman-SEM microscopy for the quantitative analysis of plasmonic particles and structures, thus enabling a new analytical method in the field of SERS and plasmonics.

La importancia de ser grande

OpenAIRE

Baisre, J. A.

2007-01-01

Se responde a las preguntas ¿por qué los mamíferos marinos son los animales más grandes del planeta?, ¿Por qué los peces no pueden ser más grandes?. Éstas y otras interrogantes son respondidas de forma sencilla y clara.

Study of pyruvate decarboxylase and thiamine kinase from brewer's yeast by SERS

Science.gov (United States)

Maskevich, Sergei A.; Chernikevich, Ivan P.; Gachko, Gennedy A.; Kivach, Leonid N.; Strekal, Nataliya D.

1993-06-01

The Surface Enhanced Raman Scattering (SERS) spectra of holopyruvate decarboxylase (PDC) and thiamine kinase (ThK) adsorbed on silver electrode were obtained. In contrast to the Raman, the SERS spectrum of PDC contained no modes of tryptophan residues, it indicates a removal of this moiety from the surface. In the SERS spectrum of ThK the bands belonging to ligands bound to the protein were observed. A correlation between the SERS signal intensity and the enzymatic activity of the ThK separate fraction and found. The influence of amino acids on SERS spectra of thiamine (Th) was studied to determine the possible composition on microsurrounding of coenzyme.

PTA hardfacing of Nb/Al coatings Revestimentos Nb/Al depositados por PTA

Directory of Open Access Journals (Sweden)

Karin Graf

2012-06-01

Full Text Available Hardfacing is widely applied to components yet the majority of the welding techniques available restrain the variety of hard alloys that can be deposited. Plasma Transferred Arc hardfacing offsets this drawback by using powdered feedstock offering the ability to tailor the chemical composition of the coating and as a consequence its properties. The high strength and chemical inertia of aluminide alloys makes them very suitable to protect components. However, the strong interaction with the substrate during hardfacing requires analysis of each alloy system to optimize its properties and weldability. This work analyzed coatings processed with a cast and ground Nb40wt%Al alloy and the effect of Fe and C on the coatings features. It confirmed that sound Nb aluminide coatings can be processed by plasma Transferred arc hardfacing and will have a strong interaction with the substrate, which determines the final microstructure and properties of coatings. Final remarks point out that during Nb-Al coating tailoring the interaction with the substrate has to be considered at the early stages of design process.Revestimentos soldados são amplamente usados para proteger componentes mecânicos entretanto a maioria das técnicas de soldagem disponíveis restringe a variedade de ligas de alta resistência que podem ser depositadas. O processo de plasma por arco transferido permite ultrapassar esta limitação ao utilizar material de adição na forma de pó, oferecendo a possibilidade de se customizar a composição dos revestimentos e em consequências as suas propriedades. A elevada resistência mecânica e inercia química das ligas de aluminetos tornam estas ligas atrativas para a proteção de componentes diversos. Entretanto a grande interação com o substrato que ocorre quando do processamento exige que para a otimização das propriedades e soldabilidade seja realizada uma a análise de cada sistema liga e substrato. Neste trabalho foram processados e

Sonochemically synthesized Ag nanoparticles as a SERS active substrate and effect of surfactant

Energy Technology Data Exchange (ETDEWEB)

Dar, Nitzan, E-mail: n58987012@mail.ncku.edu.tw [Department of Material Science and Engineering, National Cheng Kung University, Tainan 70101 Taiwan (China); Chen, Kuang-Yu [Department of Material Science and Engineering, National Cheng Kung University, Tainan 70101 Taiwan (China); Nien, Yung-Tang, E-mail: ytnien@nfu.edu.tw [Department of Materials Science and Engineering, National Formosa University, Huwei, Yunlin 63201, Taiwan (China); Perkas, Nina [Institute of nanotechnology and advanced materials, Department of Chemistry, Bar-Ilan University, Ramat-Gan 5290002 (Israel); Gedanken, Aharon, E-mail: Aharon.Gedanken@biu.ac.il [Institute of nanotechnology and advanced materials, Department of Chemistry, Bar-Ilan University, Ramat-Gan 5290002 (Israel); Chen, In-Gann, E-mail: ingann@mail.ncku.edu.tw [Department of Material Science and Engineering, National Cheng Kung University, Tainan 70101 Taiwan (China)

2015-03-15

Highlights: • Solid state Ag SERS active substrates were sonochemically synthesized. • High intensity SERS spectra of both crystal violet and rhodamine 6G were observed. • We discovered that PVP aided synthesized substrates showed higher SERS intensity. - Abstract: Surface enhanced Raman scattering (SERS) enables the detection of substances at low concentrations using silver or gold nanostructure. The SERS technique has many applications, such as environmental detection and biosensing. Sonochemistry is an excellent and cheap deposition technique for coating substrates in a form of nanostructure at ambient temperature. It can also be utilized to prepare large SERS substrates. Here, we used the advantages of sonochemistry to deposit solid SERS substrates immobilized on GaN nanostructure. Morphology was studied by scanning electron microscopy. The elemental composition and the spatial distribution were examined by energy dispersive X-ray spectroscopy. The crystal structure and atomic presence was confirmed by X-ray diffraction. SERS substrates were examined with the analytes crystal violet (10{sup −5} M) and rhodamine 6G (10{sup −6} M), they showed prominent characteristic peaks. We discovered that the SERS intensity of poly-vinyl-pyrrolidinone aided sonochemical deposition of Ag nanoparticles was increased. The reason for the effect is morphological changes of the Ag nanoparticles. Smaller nanoparticles were fabricated, which increase their SERS intensity.

Designing multilayered nanoplatforms for SERS-based detection of genetically modified organisms

Science.gov (United States)

Uluok, Saadet; Guven, Burcu; Eksi, Haslet; Ustundag, Zafer; Tamer, Ugur; Boyaci, Ismail Hakki

2015-01-01

In this study, the multilayered surface-enhanced Raman spectroscopy (SERS) platforms were developed for the analysis of genetically modified organisms (GMOs). For this purpose, two molecules [11-mercaptoundecanoic acid (11-MUA) and 2-mercaptoethylamine (2-MEA)] were attached with Aurod and Auspherical nanoparticles to form multilayered constructions on the gold (Au)slide surface. The best multilayered platform structure was chosen depending on SERS enhancement, and this surface was characterised with atomic force microscopy (AFM) and attenuated total reflectance Fourier transform infrared spectroscopy. After the optimum multilayered SERS platform and nanoparticle interaction was identified, the oligonucleotides on the Aurod nanoparticles and Auslide were combined to determine target concentrations from the 5,5'-dithiobis (2-nitrobenzoic acid) (DTNB) signals using SERS. The correlation between the SERS intensities for DTNB and target concentrations was found to be linear within a range of 10 pM to 1 µM, and with a detection limit of 34 fM. The selectivity and specificity of the developed sandwich assay were tested using negative and positive controls, and nonsense and real sample studies. The obtained results showed that the multilayered SERS sandwich method allows for sensitive, selective, and specific detection of oligonucleotide sequences.

SERS-based pesticide detection by using nanofinger sensors

Science.gov (United States)

Kim, Ansoon; Barcelo, Steven J.; Li, Zhiyong

2015-01-01

Simple, sensitive, and rapid detection of trace levels of extensively used and highly toxic pesticides are in urgent demand for public health. Surface-enhanced Raman scattering (SERS)-based sensor was designed to achieve ultrasensitive and simple pesticide sensing. We developed a portable sensor system composed of high performance and reliable gold nanofinger sensor strips and a custom-built portable Raman spectrometer. Compared to the general procedure and previously reported studies that are limited to laboratory settings, our analytical method is simple, sensitive, rapid, and cost-effective. Based on the SERS results, the chemical interaction of two pesticides, chlorpyrifos (CPF) and thiabendazole (TBZ), with gold nanofingers was studied to determine a fingerprint for each pesticide. The portable SERS-sensor system was successfully demonstrated to detect CPF and TBZ pesticides within 15 min with a detection limit of 35 ppt in drinking water and 7 ppb on apple skin, respectively.

PKCδ-mediated IRS-1 Ser24 phosphorylation negatively regulates IRS-1 function

International Nuclear Information System (INIS)

Greene, Michael W.; Ruhoff, Mary S.; Roth, Richard A.; Kim, Jeong-a; Quon, Michael J.; Krause, Jean A.

2006-01-01

The IRS-1 PH and PTB domains are essential for insulin-stimulated IRS-1 Tyr phosphorylation and insulin signaling, while Ser/Thr phosphorylation of IRS-1 disrupts these signaling events. To investigate consensus PKC phosphorylation sites in the PH-PTB domains of human IRS-1, we changed Ser24, Ser58, and Thr191 to Ala (3A) or Glu (3E), to block or mimic phosphorylation, respectively. The 3A mutant abrogated the inhibitory effect of PKCδ on insulin-stimulated IRS-1 Tyr phosphorylation, while reductions in insulin-stimulated IRS-1 Tyr phosphorylation, cellular proliferation, and Akt activation were observed with the 3E mutant. When single Glu mutants were tested, the Ser24 to Glu mutant had the greatest inhibitory effect on insulin-stimulated IRS-1 Tyr phosphorylation. PKCδ-mediated IRS-1 Ser24 phosphorylation was confirmed in cells with PKCδ catalytic domain mutants and by an RNAi method. Mechanistic studies revealed that IRS-1 with Ala and Glu point mutations at Ser24 impaired phosphatidylinositol-4,5-bisphosphate binding. In summary, our data are consistent with the hypothesis that Ser24 is a negative regulatory phosphorylation site in IRS-1

O cotidiano do ser-adolescendo com aids: movimento ou momento existencial? El cotidiano del ser-adolecer con sida: ¿movimiento o momento existencial? The daily life of adolescents with aids: existential movement or moment?

Directory of Open Access Journals (Sweden)

Cristiane Cardoso de Paula

2009-09-01

diarias, ocio y relacionamientos. Transitando entre estos momentos, se re-vela como un ser-adolecer . En este movimiento existencial se re-vela como un ser-de-posibilidades, que no está limitado a este doble acontecer : adolecer (según demarcaciones de la edad y características predeterminadas y Sida (fragilidad clínica. Ahí reside el desafío de conjugar la dimensión biológica y existencial, en un modelo asistencial-institucional de cuidado al ser-adolecer.Children with vertical transmission HIV pass from childhood to adolescence and little is known about how they care for themselves. The objective was to understand the daily life of adolescents with AIDS. Heiddeger's hermeneutic analyzes was applied. The phenomenological interview of 11 non-institutionalized boys and girls (12-14 years with a disclosed diagnosis took place in 3 reference healthcare facilities in Rio de Janeiro. The comprehensive analysis showed that adolescents' daily live is marked by childhood and adolescent moments. In childhood, there is a desire to play like other children. In adolescence, there is a desire to be like others in appearance, mood, daily activities, leisure and relationship. In passing between these two moments, a process of becoming adolescent is revealed. In this existential movement they reveal as a being-with-possibilities that are not limited in the double-facticity: adolescence (according to etaria marks and predetermined characteristics and AIDS (clinical fragility. Therein resides the challenge of conjugating biological and existential dimensions in adolescent care.

Effect of the size of silver nanoparticles on SERS signal enhancement

Science.gov (United States)

He, Rui Xiu; Liang, Robert; Peng, Peng; Norman Zhou, Y.

2017-08-01

The localized surface plasmon resonance arising from plasmonic materials is beneficial in solution-based and thin-film sensing applications, which increase the sensitivity of the analyte being tested. Silver nanoparticles from 35 to 65 nm in diameter were synthesized using a low-temperature method and deposited in a monolayer on a (3-aminopropyl)triethoxysilane (APTES)-functionalized glass slide. The effect of particle size on monolayer structure, optical behavior, and surface-enhanced Raman scattering (SERS) is studied. While increasing particle size decreases particle coverage, it also changes the localized surface plasmon resonance and thus the SERS activity of individual nanoparticles. Using a laser excitation wavelength of 633 nm, the stronger localized surface plasmon resonance coupling to this excitation wavelength at larger particle sizes trumps the loss in surface coverage, and greater SERS signals are observed. The SERS signal enhancement accounts for the higher SERS signal, which was verified using a finite element model of a silver nanoparticle dimer with various nanoparticle sizes and separation distances.

Positive selection at codon 38 of the human KCNE1 (= minK gene and sporadic absence of 38Ser-coding mRNAs in Gly38Ser heterozygotes

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Pfeufer Arne

2009-08-01

Full Text Available Abstract Background KCNE1 represents the regulatory beta-subunit of the slowly activating delayed rectifier potassium channel (IKs. Variants of KCNE1 have repeatedly been linked to the long-QT syndrome (LQTS, a disorder which predisposes to deafness, ventricular tachyarrhythmia, syncope, and sudden cardiac death. Results We here analyze the evolution of the common Gly38Ser variant (rs1805127, using genomic DNAs, complementary DNAs, and HEK293-expressed variants of altogether 19 mammalian species. The between species comparison reveals that the human-specific Gly38Ser polymorphism evolved under strong positive Darwinian selection, probably in adaptation to specific challenges in the fine-tuning of IKs channels. The involved amino acid exchanges (Asp > Gly, Gly > Ser are moderately radical and do not induce apparent changes in posttranslational modification. According to population genetic analyses (HapMap phase II a heterozygote advantage accounts for the maintenance of the Gly38Ser polymorphism in humans. On the other hand, the expression of the 38Ser allele seems to be disadvantageous under certain conditions, as suggested by the sporadic deficiency of 38Ser-coding mRNAs in heterozygote Central Europeans and the depletion of homozygotes 38Ser in the Yoruban sample. Conclusion We speculate that individual differences in genomic imprinting or genomic recoding might have contributed to conflicting results of recent association studies between Gly38Ser polymorphism and QT phenotype. The findings thus highlight the relevance of mRNA data in future association studies of genotypes and clinical disorders. To the best of our knowledge, they moreover provide first time evidence for a unique pattern; i.e. coincidence of positive Darwinian selection and polymorphism with a sporadically suppressed expression of one allele.

"Ser diferente é normal?"/"Being different: is it normal?"

Directory of Open Access Journals (Sweden)

Viviane Veras

2007-01-01

Full Text Available A pergunta título deste trabalho retoma o slogan “Ser diferente é normal”, que é parte da campanha criada para uma organização não-governamental que atende portadores de Síndrome de Down. O objetivo é a inclusão social da pessoa com deficiência e o primeiro passo foi propor a inclusão de um grupo de diferentes no grupo dito normal. No vídeo de lançamento da campanha, o diferente, identificado como normal, é mostrado por meio de exemplos – um negro com cabelo black-power, um skin-head, um corpo tatuado, um corpo feminino halterofílico, uma família hippie, uma garota com síndrome de Down. A visão da adolescente dançando reduz, de certo modo, o efeito imaginário que vai além da síndrome, uma vez que apenas o corpo com seus olhinhos puxados se destacam, e não se interrogam questões cognitivas. Minha proposta é refletir sobre o estatuto paradoxal do exemplo, tal como é trabalhado nesse vídeo: se, por definição, um exemplo mostra de fato seu pertencimento a uma classe, pode-se concluir que é exatamente por ser exemplar que ele se encontra fora dela, no exato momento em que a exibe e define. The question in the title of this paper refers to the slogan "ser diferente é normal" ("It´s normal to be different", which is part of a campaign created for a NGO that supports people with Down syndrome. The objective of the campaign is to promote the social inclusion of individuals with Down syndrome, and the first step was to propose the inclusion of a group of "differents" in the so-called normal group. The film launching the campaign shows the different identified as normal by means of examples: a black man exhibiting blackpower haircut, a skin-head, a tattooed body, an over-athletic female body, a hippie family and a girl with Down syndrome. The vision of the dancing teenager lessens the imaginary effect that surpasses the syndrome, since only her body and her little oriental eyes stand out and no cognitive issues are

Nota editorial. La cirugía en París: Carta de un cirujano parisiense al doctor Jorge Calvo Escobar

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J. Braine

1938-07-01

La creación de un diploma especial de cirujano ha sido muy discutida en el curso de los últimos años. Estaría destinada a encauzar la ola creciente de ciertas incompetencias que arriesgan, al democratizar en exceso, envilecer y arrastrar al abismo el ejercicio de la cirugía. Esta idea, por el momento latente, será vuelta a tener en cuenta próximamente. Parece cierto que si este diploma de especialidad se adopta, debe ser conferido por la Facultad y no por un órgano corporativo como el Sindicato de Cirujanos Franceses, que pensó recientemente reservarse el privilegio.

Effect of Interface energy and electron transfer on shape, plasmon resonance and SERS activity of supported surfactant-free gold nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Giangregorio, Maria M. [Institute of Inorganic Methodologies and of Plasmas, CNR-IMIP; Dastmalchi, Babak [Ames Laboratory; Suvorova, Alexandra [University of Western Australia; Bianco, Giuseppe V. [Institute of Inorganic Methodologies and of Plasmas, CNR-IMIP; Hingerl, Kurt [Johannes Kepler University Linz; Bruno, Giovanni [Institute of Inorganic Methodologies and of Plasmas, CNR-IMIP; Losurdo, Maria [Institute of Inorganic Methodologies and of Plasmas, CNR-IMIP

2014-01-01

For device integration purposes plasmonic metal nanoparticles must be supported/deposited on substrates. Therefore, it is important to understand the interaction between surfactant-free plasmonic metal nanoparticles and different substrates, as well as to identify factors that drive nanoparticles nucleation and formation. Here we show that for nanoparticles grown directly on supports, the substrate/nanoparticle interfacial energy affects the equilibrium shape of nanoparticles. Therefore, oblate, spherical and prolate Au nanoparticles (NPs) with different shapes have been deposited by radiofrequency sputtering on substrates with different characteristics, namely a dielectric oxide Al2O3 (0001), a narrow bandgap semiconductor Si (100), and a polar piezoelectric wide bandgap semiconductor 4H–SiC (0001). We demonstrate that the higher the substrate surface energy, the higher the interaction with the substrate, resulting in flat prolate Au nanoparticles. The resulting localized surface plasmon resonance characteristics of Au NPs/Al2O3, Au NPs/Si and Au NPs/SiC have been determined by spectroscopic ellipsometry and correlated with their structure and shape studied by transmission electron microscopy. Finally, we have demonstrated the diverse response of the tailored plasmonic substrates as ultrasensitive SERS chemical sensors. Flat oblates Au NPs on SiC result in an enhanced and more stable SERS response. The experimental findings are validated by numerical simulations of electromagnetic fields.

Chemically Roughened Solid Silver: A Simple, Robust and Broadband SERS Substrate

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Shavini Wijesuriya

2016-10-01

Full Text Available Surface-enhanced Raman spectroscopy (SERS substrates manufactured using complex nano-patterning techniques have become the norm. However, their cost of manufacture makes them unaffordable to incorporate into most biosensors. The technique shown in this paper is low-cost, reliable and highly sensitive. Chemical etching of solid Ag metal was used to produce simple, yet robust SERS substrates with broadband characteristics. Etching with ammonium hydroxide (NH4OH and nitric acid (HNO3 helped obtain roughened Ag SERS substrates. Scanning electron microscopy (SEM and interferometry were used to visualize and quantify surface roughness. Flattened Ag wires had inherent, but non-uniform roughness having peaks and valleys in the microscale. NH4OH treatment removed dirt and smoothened the surface, while HNO3 treatment produced a flake-like morphology with visibly more surface roughness features on Ag metal. SERS efficacy was tested using 4-methylbenzenethiol (MBT. The best SERS enhancement for 1 mM MBT was observed for Ag metal etched for 30 s in NH4OH followed by 10 s in HNO3. Further, MBT could be quantified with detection limits of 1 pM and 100 µM, respectively, using 514 nm and 1064 nm Raman spectrometers. Thus, a rapid and less energy intensive method for producing solid Ag SERS substrate and its efficacy in analyte sensing was demonstrated.

Surface-enhanced Raman scattering (SERS) for detection of phenylketonuria for newborn screening

Science.gov (United States)

Javanmard, M.; Davis, R. W.

2014-02-01

Diagnosis of Phenylketonuria (PKU) in newborns is important because it can potentially help prevent mental retardation since it is treatable by dietary means. PKU results in phenylketonurics having phenylalanine levels as high as 2 mM whereas the normal upper limit in healthy newborns is 120 uM. To this end, we are developing a microfluidic platform integrated with a SERS substrate for detection of high levels of phenylalanine. We have successfully demonstrated SERS detection of phenylalanine using various SERS substrates fabricated using nanosphere lithography, which exhibit high levels of field enhancement. We show detection of SERS at clinically relevant levels.

Plasmonic crystal based solid substrate for biomedical application of SERS

Science.gov (United States)

Morasso, Carlo F.; Mehn, Dora; Picciolini, Silvia; Vanna, Renzo; Bedoni, Marzia; Gramatica, Furio; Pellacani, Paola; Frangolho, Ana; Marchesini, Gerardo; Valsesia, Andrea

2014-02-01

Surface Enhanced Raman Spectroscopy is a powerful analytical technique that combines the excellent chemical specificity of Raman spectroscopy with the good sensitivity provided by the enhancement of the signal observed when a molecule is located on (or very close to) the surface of suitable nanostructured metallic materials. The availability of cheap, reliable and easy to use SERS substrates would pave the road to the development of bioanalytical tests that can be used in clinical practice. SERS, in fact, is expected to provide not only higher sensitivity and specificity, but also the simultaneous and markedly improved detection of several targets at the same time with higher speed compared to the conventional analytical methods. Here, we present the SERS activity of 2-D plasmonic crystals made by polymeric pillars embedded in a gold matrix obtained through the combination of soft-lithography and plasma deposition techniques on a transparent substrates. The use of a transparent support material allowed us to perform SERS detection from support side opening the possibility to use these substrates in combination with microfluidic devices. In order to demonstrate the potentialities for bioanalytical applications, we used our SERS active gold surface to detect the oxidation product of apomorphine, a well-known drug molecule used in Parkinson's disease which has been demonstrated being difficult to study by traditional HPLC based approaches.

Narrativas em convergências: ser-agir em uma metodologia complexa / Narratives in convergences: being-acting in a complex methodology

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Felipe Gustsack

2007-01-01

Full Text Available Esse estudo questiona a suficiência dos aportes teóricos vinculados ao paradigma da complexidade para a emergência de uma metodologia complexa da aprendizagem e demais afazeres do campo da educação. Nossas hipóteses partem da convicção de que tais constructos dão conta dessas especificidades, potencializando o conhecer como um ser-agir em convivência. Procuramos demonstrar essa perspectiva, nesse texto, procedendo à descrição do funcionamento do Grupo de Ações e Investigações Autopoiéticas - GAIA, colocando-nos como sujeitos das ações de pesquisa, como observadores implicados no ato mesmo de observar, o que vincula este estudo às abordagensautopoiéticas e metacognitivas. O desafio é possibilitar, a partir de vivências dialógicas em ambientes complexos como as redes presenciais e virtuais de aprendizagens, novas compreensões acerca da inseparabilidade do conhecer-viver como fluxo passível de aplicação na educação. Articulando pesquisas de diferentes áreas do conhecimento, os pesquisadores envolvidos com o GAIA tendem a convergir na defesa de uma educação que se tece junto; que faz emergir o respeito mútuo, a amorosidade e também a morosidade necessária ao ser-agir na consciência de que cada organismo conspira para a vida com seu próprio ritmo e implicações cósmicas. Nossas conclusões apontam para vínculos significativos entre os recortes teóricos apresentados e a compreensão do observar-agir com um modo de pesquisar e de aprender, tendo como veículos as narrativas dogrupo em convergências diversas, processo que nominamos como ontoepistemogênese. Além disso, demonstramos com esse estudo a processualidade das narrativas como fluxos que nos permitem mapear uma metodologia complexa, que emerge e faz emergir o ser-conhecer a partir de padrões que conectam e marcadores conceituais.AbstractEse estudio cuestiona la suficiencia de los aportes teóricos vinculados al paradigma de la complejidad para la

Descripción del coronógrafo a ser instalado en Argentina (MICA)

Science.gov (United States)

Stenborg, G.; Francile, C.; Schwenn, R.; Epple, A.; Rovira, M.

El ``Coronógrafo de espejo para Argentina'' es un telescopio solar terrestre a ser colocado en el Observatorio Astronómico Félix Aguilar (El Leoncito), antes de finalizar 1996, como parte de un programa de ciencia bilateral entre Alemania y Argentina. Eclipses fotográficos de alta resolución han revelado que la corona solar es altamente estructurada y variable. De hecho, está contínuamente deformada y moldeada por los movimientos convectivos de los extremos de los arcos magnéticos en la fotosfera, estando, en muchas oportunidades, afectada por explosivas liberaciones de energía. MICA, en conjunción con otros telescopios solares espaciales y terrestres, tratará de contribuir al entendimiento de cuestiones fundamentales de la física solar. Entre ellas: cómo la corona está siendo calentada, dónde y cómo el viento solar es acelerado, qué causa los transitorios coronales, etc. Para ello investigará la distribución de los parámetros del plasma y su evolución con el tiempo, la estructura espacial de la corona en fina y gran escala, procesos que ocurren en los transitorios coronales y factores que los disparan, etc. Para responder a estas cuestiones MICA observará la atmósfera solar por sobre el limbo entre 1.1 y 2 radios solares aproximadamente, usando un nuevo tipo de sistema coronográfico que permite suprimir el brillo del disco solar suficientemente bien, tomando las imágenes con una cámara CCD de 1024x1024 pixels, codificada en 12 bits, pudiendo el mismo ser operado en forma remota. En la presente exposición describiremos las características del instrumento, cómo será controlado y qué esperamos observar basados en las imágenes obtenidas por los telescopios de similares características LASCO C1 a bordo del SOHO y PICO (ubicado en el Observatorio de Pic du Midi, Francia).

La filosofía de Marcel: del idealismo al realismo, del realismo a la filosofía concreta

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Julia Urabayen

2016-10-01

Full Text Available En estas páginas se reflexiona acerca del significado del pensamiento de Marcel para delimitar qué es la filosofia concreta. Se incide en su formación neoidealista y su contacto con Bergson, que le conduce a una crítica del pensamiento sistemático que se agudiza tras la Primera Guerra Mundial. En segundo lugar, se produce un acercamiento al realismo, pero aparece un punto de desavenencia: para Marcel el ser está más allá del juicio predicativo. De ahí que opte por una filosofía existencial basada en dualismos y que se desarrolla como una serie de acercamientos al ser y no como una ontología.

Comparison of H/Al stoichiometry of mineral and organic soils in Brazil Comparação da estequiometria H/Al em solos minerais e orgânicos brasileiros

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Daniel Vidal Perez

2009-08-01

Full Text Available Exchangeable Al has been used as a criterion for the calculation of lime requirement in several Brazilian States. However, the laboratory method with extraction by a 1 mol L-1 KCl solution followed by indirect alkaline titration is not accurate for some Brazilian soils, mainly in the case of soils with high organic matter content. The objective of this study was therefore to evaluate the stoichiometry of H+/Al3+ in KCl soil extracts. The results suggested that organically complexed Al is the main contributor to exchangeable acidity in soils enriched with organic matter. Liming recommendations for organic soils based exclusively on exchangeable Al determined by the NaOH titration method should therefore be revised.A determinação de alumínio trocável é utilizada como critério para cálculo de calagem em vários estados brasileiros. Contudo, a determinação indireta pela titulação com NaOH, após extração com solução de KCl 1 mol L-1, pode não ser adequada para certos tipos de solos brasileiros, notadamente aqueles que apresentem altos teores de carbono orgânico. Dessa forma, o principal objetivo deste trabalho foi avaliar a estequiometria da relação H+/Al3+ em extratos de KCl. Os resultados obtidos sugerem que o Al complexado pela matéria orgânica, em solos orgânicos, é o principal contribuinte para a acidez trocável obtida por titulação. Dessa forma, a recomendação de calagem em solos orgânicos baseado somente na determinação de alumínio trocável por titulação com NaOH deve ser revista.

An association between apo-A4 gene polymorphism (Thr347Ser ...

African Journals Online (AJOL)

Pramod Kumar

Objective: We aimed at studying the relationship between apoA4 gene polymorphisms (Thr347Ser and ... showed significant association with lipid risk factors like high levels of ..... in German population showed that Ser347 allele is associated.

Highly Sensitive Filter Paper Substrate for SERS Trace Explosives Detection

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Pedro M. Fierro-Mercado

2012-01-01

Full Text Available We report on a novel and extremely low-cost surface-enhanced Raman spectroscopy (SERS substrate fabricated depositing gold nanoparticles on common lab filter paper using thermal inkjet technology. The paper-based substrate combines all advantages of other plasmonic structures fabricated by more elaborate techniques with the dynamic flexibility given by the inherent nature of the paper for an efficient sample collection, robustness, and stability. We describe the fabrication, characterization, and SERS activity of our substrate using 2,4,6-trinitrotoluene, 2,4-dinitrotoluene, and 1,3,5-trinitrobenzene as analytes. The paper-based SERS substrates presented a high sensitivity and excellent reproducibility for analytes employed, demonstrating a direct application in forensic science and homeland security.

BACH1 Ser919Pro variant and breast cancer risk

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Eerola Hannaleena

2006-01-01

Full Text Available Abstract Background BACH1 (BRCA1-associated C-terminal helicase 1; also known as BRCA1-interacting protein 1, BRIP1 is a helicase protein that interacts in vivo with BRCA1, the protein product of one of the major genes for hereditary predisposition to breast cancer. Previously, two BACH1 germ line missense mutations have been identified in early-onset breast cancer patients with and without family history of breast and ovarian cancer. In this study, we aimed to evaluate whether there are BACH1 genetic variants that contribute to breast cancer risk in Finland. Methods The BACH1 gene was screened for germ line alterations among probands from 43 Finnish BRCA1/2 negative breast cancer families. Recently, one of the observed common variants, Ser-allele of the Ser919Pro polymorphism, was suggested to associate with an increased breast cancer risk, and was here evaluated in an independent, large series of 888 unselected breast cancer patients and in 736 healthy controls. Results Six BACH1 germ line alterations were observed in the mutation analysis, but none of these were found to associate with the cancer phenotype. The Val193Ile variant that was seen in only one family was further screened in an independent series of 346 familial breast cancer cases and 183 healthy controls, but no additional carriers were observed. Individuals with the BACH1 Ser919-allele were not found to have an increased breast cancer risk when the Pro/Ser heterozygotes (OR 0.90; 95% CI 0.70–1.16; p = 0.427 or Ser/Ser homozygotes (OR 1.02; 95% CI 0.76–1.35; p = 0.91 were compared to Pro/Pro homozygotes, and there was no association of the variant with any breast tumor characteristics, age at cancer diagnosis, family history of cancer, or survival. Conclusion Our results suggest that the BACH1 Ser919 is not a breast cancer predisposition allele in the Finnish study population. Together with previous studies, our results also indicate that although some rare germ line variants

BACH1 Ser919Pro variant and breast cancer risk

International Nuclear Information System (INIS)

Vahteristo, Pia; Yliannala, Kristiina; Tamminen, Anitta; Eerola, Hannaleena; Blomqvist, Carl; Nevanlinna, Heli

2006-01-01

BACH1 (BRCA1-associated C-terminal helicase 1; also known as BRCA1-interacting protein 1, BRIP1) is a helicase protein that interacts in vivo with BRCA1, the protein product of one of the major genes for hereditary predisposition to breast cancer. Previously, two BACH1 germ line missense mutations have been identified in early-onset breast cancer patients with and without family history of breast and ovarian cancer. In this study, we aimed to evaluate whether there are BACH1 genetic variants that contribute to breast cancer risk in Finland. The BACH1 gene was screened for germ line alterations among probands from 43 Finnish BRCA1/2 negative breast cancer families. Recently, one of the observed common variants, Ser-allele of the Ser919Pro polymorphism, was suggested to associate with an increased breast cancer risk, and was here evaluated in an independent, large series of 888 unselected breast cancer patients and in 736 healthy controls. Six BACH1 germ line alterations were observed in the mutation analysis, but none of these were found to associate with the cancer phenotype. The Val193Ile variant that was seen in only one family was further screened in an independent series of 346 familial breast cancer cases and 183 healthy controls, but no additional carriers were observed. Individuals with the BACH1 Ser919-allele were not found to have an increased breast cancer risk when the Pro/Ser heterozygotes (OR 0.90; 95% CI 0.70–1.16; p = 0.427) or Ser/Ser homozygotes (OR 1.02; 95% CI 0.76–1.35; p = 0.91) were compared to Pro/Pro homozygotes, and there was no association of the variant with any breast tumor characteristics, age at cancer diagnosis, family history of cancer, or survival. Our results suggest that the BACH1 Ser919 is not a breast cancer predisposition allele in the Finnish study population. Together with previous studies, our results also indicate that although some rare germ line variants in BACH1 may contribute to breast cancer development, the

Trace determination of thiram using SERS-active hollow sea-urchin gold nanoparticles

International Nuclear Information System (INIS)

Zhang, Guanghui; Zhang, Chuankun; Ma, Yanan; Wang, Zheng; Wang, Shun; Xu, Chan; Wang, Dashuang

2017-01-01

Surface-enhanced Raman scattering (SERS) is greatly structure-dependent on the absorbed nanoparticles. Nanostructures with different novel morphologies show different Raman enhancement factor orders of magnitude. Herein, a unique nanostructure with fruitful SERS-active sites, composed of hollow interiors and thorns which named as hollow sea-urchin gold nanoparticles (HSU-GNPs), was synthesized by using a one-pot galvanic replacement method. And the corresponding morphologies and optical properties were characterized by TEM images and absorption spectra. Importantly, the synthetic parameters of HSU-GNPs were optimized to obtain a superior SERS performance by analyzing the formation mechanism and the SERS spectra of R6G-labeled HSU-GNPs which obtained at different concentrations of AgNO_3. Furthermore, the SERS-based application of HSU-GNPs was performed on the dose-response detection of thiram. The experimental result shows this detection strategy is available for thiram with decent sensitivity and reproducibility, which suggests that it is an excellent candidate for the detection of pesticides.

Trace determination of thiram using SERS-active hollow sea-urchin gold nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Zhang, Guanghui; Zhang, Chuankun, E-mail: zhangchk-lx@huat.edu.cn; Ma, Yanan; Wang, Zheng; Wang, Shun; Xu, Chan; Wang, Dashuang [Hubei University of Automotive Technology, School of Science (China)

2017-04-15

Surface-enhanced Raman scattering (SERS) is greatly structure-dependent on the absorbed nanoparticles. Nanostructures with different novel morphologies show different Raman enhancement factor orders of magnitude. Herein, a unique nanostructure with fruitful SERS-active sites, composed of hollow interiors and thorns which named as hollow sea-urchin gold nanoparticles (HSU-GNPs), was synthesized by using a one-pot galvanic replacement method. And the corresponding morphologies and optical properties were characterized by TEM images and absorption spectra. Importantly, the synthetic parameters of HSU-GNPs were optimized to obtain a superior SERS performance by analyzing the formation mechanism and the SERS spectra of R6G-labeled HSU-GNPs which obtained at different concentrations of AgNO{sub 3}. Furthermore, the SERS-based application of HSU-GNPs was performed on the dose-response detection of thiram. The experimental result shows this detection strategy is available for thiram with decent sensitivity and reproducibility, which suggests that it is an excellent candidate for the detection of pesticides.

Technology transfer and application of SERS continuous monitor for trace organic compounds

International Nuclear Information System (INIS)

Swindle, D.W. Jr.; Vo-Dinh, T.; Yalcintas, M.G.

1992-01-01

An in situ-enhanced Raman Scattering (SERS) continuous monitoring system was developed for exciting and collecting SERS signals generated on silver-coated microparticles deposited on a continuously rotating filter-paper support. SERS measurements were successfully conducted for several organic compounds. An in situ SERS fiber-optic system was also developed for exciting and collecting SERS signals generated from a sensing tip having silver-coated microparticles deposited on a glass-plate support. These devices will be very useful in remote identification of unknown chemicals from hazardous waste sites. This patented technology has been licensed from Oak Ridge National Laboratory to an analytical instrumentation firm which is in the process of completing development and marketing these detectors. Advantages to using this technology range from increased safety and sensitivity for detecting hazardous compounds to better statistics and reliable results. During this presentation, efforts of the Environmental Restoration Program to evaluate and support development of this technology will be described

Gold dimer nanoantenna with slanted gap for tunable LSPR and improved SERS

KAUST Repository

Kessentini, Sameh

2014-02-13

We focus on improving the surface-enhanced Raman scattering (SERS) of dimer nanoantenna by tailoring the shape of the coupled nanoantennas extremities from rounded to straight or slanted ones. A numerical model based on the discrete dipole approximation method-taking into account periodicity, adhesion layer, and roughness-is first validated by comparison with localized surface plasmon resonance (LSPR) and SERS experiments on round-edged dimer nanoantennas and then used to investigate the effect of the straight or slanted gap in the dimer antenna. Simulations show that both LSPR and SERS can be tuned by changing the gap slanting angle. The SERS enhancement factor can also be improved by 2 orders of magnitude compared to the one reached using a rounded gap. Therefore, the slanting angle can be used as a new control parameter in the design of SERS substrates to guarantee stronger field confinement and higher sensitivity, especially as its feasibility is demonstrated. © 2014 American Chemical Society.

Gold dimer nanoantenna with slanted gap for tunable LSPR and improved SERS

KAUST Repository

Kessentini, Sameh; Barchiesi, Dominique; D'Andrea, Cristiano; Toma, Andrea; Guillot, Nicolas; Di Fabrizio, Enzo M.; Fazio, Barbara; Maragó , Onofrio M.; Gucciardi, Pietro Giuseppe; Lamy De La Chapelle, Marc L.

2014-01-01

We focus on improving the surface-enhanced Raman scattering (SERS) of dimer nanoantenna by tailoring the shape of the coupled nanoantennas extremities from rounded to straight or slanted ones. A numerical model based on the discrete dipole approximation method-taking into account periodicity, adhesion layer, and roughness-is first validated by comparison with localized surface plasmon resonance (LSPR) and SERS experiments on round-edged dimer nanoantennas and then used to investigate the effect of the straight or slanted gap in the dimer antenna. Simulations show that both LSPR and SERS can be tuned by changing the gap slanting angle. The SERS enhancement factor can also be improved by 2 orders of magnitude compared to the one reached using a rounded gap. Therefore, the slanting angle can be used as a new control parameter in the design of SERS substrates to guarantee stronger field confinement and higher sensitivity, especially as its feasibility is demonstrated. © 2014 American Chemical Society.

El Marketing Sensorial : Un estudio empírico aplicado al marketing olfativo

OpenAIRE

Hernández Callejón, Mario

2016-01-01

En cuanto a la estructura del trabajo, será la siguiente: En primer lugar,bloque de introducción a la importancia de la experiencia en el proceso de compra. En segundo lugar, bloque dedicado al marketing sensorial. El tercer bloque irá destinado al diseño de la investigación en la que se analizará el efecto del olfato sobre el recuerdo. Finalmente, estableceremos las oportunas conclusiones, así como futuras líneas de investigación. Facultad de Ciencias de la Empresa Universidad Politécn...

El Hotel Burj Al Arab. Consideraciones de su desempeño sostenible.

OpenAIRE

Avila Higuera, Luis Fernando; Caicedo Lemus, José Fabio; Reyes Gaona, Javier Andrés; Tibaquirá Quintero, Carlos Alberto; Villamizar Bermúdez, María Clara

2013-01-01

El Hotel Burj Al Arab, ubicado en Dubai, Emiratos Árabes Unidos fue concebi-do y construido debido a la necesidad económica de convertir al emirato en un destino turís-tico, considerando que la actividad petrolera predominante en la región, no perdurará. Con un clima bastante exigente (Tropical húmedo), el edificio ha debido ser diseñado teniendo en cuenta consideraciones bioclimáticas y sostenibles. El artículo presenta un análisis bioclimático y de automatización del edificio considera...

IDENTIFICACIÓN DE POLÍMEROS MEDIANTE ESPECTROSCOPIA DE EMISIÓN DE PLASMAS PRODUCIDOS POR LÁSER (LIBS

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DANIEL DÍAZ

2009-01-01

Full Text Available Se espera que en Colombia en los próximos años se realicen misiones humanitarias para la remoción de Artefactos Explosivos Improvisados (AEI para asegurar el tránsito de personas y bienes, particularmente en zonas rurales. Entre las tecnologías que apoyan las labores de desminado humanitario, la espectroscopia de emisión de plasmas producidos por láser (LIBS tiene la capacidad de identificar explosivos y las cubiertas utilizadas en la fabricación de AEIs. En este trabajo la técnica LIBS se usó para identificar y caracterizar a nivel de laboratorio cinco polímeros que pueden ser usados en la fabricación de AEIs: polivinil cloruro, polietileno de alta densidad, polietileno tereftalato, poliestireno y polipropileno. Se utilizó el coeficiente de correlación lineal para la identificación de los polímeros. Se lograron identificar satisfactoriamente todos los polímeros al compararlos con librerías de distintas sustancias utilizando el promedio de cinco espectros en la ventana de análisis centrada en 255 nm.

Self-assembly Ag nanoparticle monolayer film as SERS Substrate for pesticide detection

Energy Technology Data Exchange (ETDEWEB)

Zhang, Li, E-mail: zhlisuzh@163.com [School of Chemistry and Life Science, Anhui Key Laboratory of Spin Electron and Nanomaterials (Cultivating Base), Suzhou University, SuZhou 234000 (China)

2013-04-01

A self-assembled protocol is introduced to provide effective platforms for the fabrication of ordered Ag nanosized monolayer film. The assembled Ag nanosized monolayer film was characterized using scanning electronic microscopy and surface-enhanced Raman scattering (SERS). The results show that the assembled SERS substrate own excellent Raman enhancement and reproducibility. The synthesized SERS-active substrate was further used to detect methyl-parathion, and the limitation of detection can reach 10{sup −7} M.

Development of an optical fiber SERS microprobe for minimally invasive sensing applications

Science.gov (United States)

Mamun, Md Abdullah Al; Juodkazis, Saulius; Mahadevan-Jansen, Anita; Stoddart, Paul R.

2018-02-01

Numerous potential biomedical sensing applications of surface-enhanced Raman scattering (SERS) have been reported, but its practical use has been limited by the lack of a robust sensing platform. Optical fiber SERS probes show great promise, but are limited by the prominent silica Raman background, which requires the use of bulky optics for filtering the signal collection and excitation delivery paths. In the present study, a SERS microprobe has been designed and developed to eliminate the bottlenecks outlined above. For efficient excitation and delivery of the SERS signal, both hollow core photonic crystal fiber and double clad fiber have been investigated. While the hollow core fiber was still found to have excessive silica background, the double clad fiber allows efficient signal collection via the multi-mode inner cladding. A micro filtering mechanism has been designed, which can be integrated into the tip of the optical fiber SERS probe, providing filtering to suppress silica Raman background and thus avoiding the need for bulky optics. The design also assists in the efficient collection of SERS signal from the sample by rejecting Rayleigh scattered light from the sample. Optical fiber cleaving using ultra-short laser pulses was tested for improved control of the fiber tip geometry. With this miniaturized and integrated filtering mechanism, it is expected that the developed probe will promote the use of SERS for minimally invasive biomedical monitoring and sensing applications in future. The probe could potentially be placed inside a small gauge hypodermic needle and would be compatible with handheld portable spectrometers.

De las pasiones al conocimiento en Farabeuf, de Salvador Elizondo

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Mari Carmen Esquivel-Colín

2015-01-01

Full Text Available Se exploraron las diferencias entre filosofía y literatura como modos de razonamiento presentes en la novela de Salvador Elizondo: Farabeuf , y se analizó la manera en que ambas disciplinas se acercan al cuerpo y las pasiones. Se encontró que el erotismo aparece en esa novela como un modo de acceder al conocimiento del alma humana. Así entendida, la verdad que la literatura propone es interior, se aparta del mero razonamiento y exige de su lector la experiencia para ser aprehendida; también ofrece la oportunidad de imaginar la muerte y el erotismo como escapes del mundo.

¿Pueden ser los tributos una herramienta de protección del medio ambiente?

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Andrés Blanco

2013-11-01

Full Text Available La lesión humana al medio ambiente, adquiere una dimensión inusitada en el capitalismo, este modo de producción tiene una propensión intrínseca al crecimiento incesante. No es esperable en lo inmediato la desaparición del capitalismo, por lo que es improbable un cambio radical en esas condiciones desfavorables. Sin embargo, es imperioso proteger la naturaleza pues el daño causado tiende a ser irreversible. Es un imperativo ético y fácticamente puede aprovecharse la adaptabilidad de la economía capitalista. El modelo más famoso de tributo para proteger el medio ambiente es el de los impuestos pigouvianos que responden a la idea de que el impuesto a quien contamine constituye para éste un costo que compensa el “costo social” que supone el daño ambiental. Esta función es incompatible con preservar a todo trance el medio ambiente: su estructura de “pago por daño” convierte al medio ambiente en una mercancía más, cuyo precio es el impuesto. No impide el desarrollo de las actividades dañinas, el carácter monopólico u oligopólico de las grandes empresas contaminantes permite compensar el costo de estos impuestos con aumentos de precios. En consecuencia, sólo la prohibición de actividades es una medida de real protección del medio ambiente.

Prominent stylistic aspects in music of Nāser Khosrow's poetry

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Morteza Mohseni

2017-04-01

Full Text Available It is axiomatic  for those who are stylistically a little familiar  about  the periods of  Persian  poetry  that  quasidas  of  Nāser-e Khosrow are totally  different  from  those  of  the  poets  in  fifth  lunar  century  both  in  terms  of  their  contents  and  technically.  This difference  is  seen  even  in  those  areas  of  his  poetry in which the poet is confided to make innovations. This paper investigates Nāser-e Khosrow's style in the field of the music of poetry. It also aims to identify his slylistic differences comparing with those of his most famous contemporaries (Onsori, Farrokhi and Manoochehri in external, lateral and internal areas.      As the first  step, all the Nāser Khosrow's poems -exept for additions section- was considered the Scope of this study, accompanied by main parts of other three cited  poets' divans (poetical works which consists almost 23600 distiches. For the second stage, each poet's divan were separatly scrutinized in three fields of the music of poetry. The frequency of each cases were recorded and after comparing statistics related to Nāser-e Khosrow's poems with other tree poets,  stylistic charachteristics of his poetry were explored. Statistical information related to the poets were generally recorded in a table and some parts of them were shown in a bar graph. It seems necessary to note that the researcher considered two items of  innovation and frequncy in all phases of the study.     Most of the studies done in the field of Nāser-e Khosrow's music of poetry, investigated the prosody and meter of his poetry. Most of these studies considered difficulty and relevancy as the important prosodic characteristics of  his poetry. Regarding the lateral and internal areas of Nāser-e Khosrow's poetry, there are not much argument proposed except for using difficult rhymes and nominal radifs ( for lateral music of poetry and attending to figures of

Effects of surface topography on SERS response: Correlating nanoscopy with spectroscopy

Science.gov (United States)

Das, Sumit Kumar; Ghosh, Manash; Chowdhury, Joydeep

2018-05-01

This paper reports for the first time the hidden correlation between the topographical features of the bilayer Langmuir-Blodgett (LB) film substrates of stearic acid (SA) incubated in Au@Ag nanocolloids over various dipping times (DTs) with their corresponding SERS responses. The topographies of the as prepared substrates are investigated from the statistical considerations in terms of lateral correlation length, interface width, Hurst and Lyapnov exponents. The real space of the substrates are mapped directly from the FESEM and AFM images of the bilayer LB film of SA immersed in Au@Ag nanocolloids over various DTs ranging between 6 and 72 h. The SERS spectra of the Rhodamine 6G molecules adsorbed on the as prepared substrates have been reported. The statistical parameters of the substrates that exhibit maximum SERS efficacy have been suggested. The far field distributions in presence and in absence of Raman dipole together with spatial distribution of the near field from the hottest spot of the as prepared substrate have also been reported. To our knowledge, this is the first report that links nanoscopy with SERS spectroscopy from statistical considerations and is expected to open a new window towards the fabrication of more efficient and reproducible SERS active substrates in future endeavours.

Evaluación del comportamiento mecánico y superficial de materiales metálicos sometidos a tratamientos de compresión mediante ondas de choque generadas por láser

OpenAIRE

Gutiérrez González, Javier

2016-01-01

El presente trabajo de fin de grado se ha desarrollado en el Centro Láser de la Universidad Politécnica de Madrid y ha consistido en la caracterización mecánica y superficial del acero AISI 316L tras haber sido tratado mediante el tratamiento “Laser peening” y el estudio de la estabilidad de las tensiones residuales inducidas al ser sometido a un tratamiento a 500ºC durante dos horas. El tratamiento LSP es un tratamiento mecánico superficial que consiste en la creación de ondas de choque ...

Rapid detection of salmonella using SERS with silver nano-substrate

Science.gov (United States)

Sundaram, J.; Park, B.; Hinton, A., Jr.; Windham, W. R.; Yoon, S. C.; Lawrence, K. C.

2011-06-01

Surface Enhanced Raman Scattering (SERS) can detect the pathogen in rapid and accurate. In SERS weak Raman scattering signals are enhanced by many orders of magnitude. In this study silver metal with biopolymer was used. Silver encapsulated biopolymer polyvinyl alcohol nano-colloid was prepared and deposited on stainless steel plate. This was used as metal substrate for SERS. Salmonella typhimurium a common food pathogen was selected for this study. Salmonella typhimurium bacteria cells were prepared in different concentrations in cfu/mL. Small amount of these cells were loaded on the metal substrate individually, scanned and spectra were recorded using confocal Raman microscope. The cells were exposed to laser diode at 785 nm excitation and object 50x was used to focus the laser light on the sample. Raman shifts were obtained from 400 to 2400 cm-1. Multivariate data analysis was carried to predict the concentration of unknown sample using its spectra. Concentration prediction gave an R2 of 0.93 and standard error of prediction of 0.21. The results showed that it could be possible to find out the Salmonella cells present in a low concentration in food samples using SERS.

Convocatoria al Premio Literario Casa de las Américas 2004

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Boletín Cultural y Bibliográfico Banco de la República

2001-09-01

Full Text Available Premio extraordinario sobre estudios de la mujer. La Casa de las Américas convoca, por segunda vez, al Premio extraordinario de ensayo sobre estudios de la mujer, dedicado a ampliar el conocimiento de obras, figuras o grupos de mujeres latinoamericanas y del Caribe que se hayan destacado en cualquier campo de la vida intelectual, social o política. Los libros que concursen se someterán a las bases generales del Premio y podrán ser enviados a cualquiera de los lugares enumerados en la base 8 antes del 30 de noviembre de 2003. El fallo del jurado será dado a conocer conjuntamente con el de los demás premios en enero de 2004.

Analysis of silver nanoparticles in antimicrobial products using surface-enhanced Raman spectroscopy (SERS).

Science.gov (United States)

Guo, Huiyuan; Zhang, Zhiyun; Xing, Baoshan; Mukherjee, Arnab; Musante, Craig; White, Jason C; He, Lili

2015-04-07

Silver nanoparticles (AgNPs) are the most commonly used nanoparticles in consumer products. Concerns over human exposure to and risk from these particles have resulted in increased interest in novel strategies to detect AgNPs. This study investigated the feasibility of surface-enhanced Raman spectroscopy (SERS) as a method for the detection and quantification of AgNPs in antimicrobial products. By using ferbam (ferric dimethyl-dithiocarbamate) as an indicator molecule that binds strongly onto the nanoparticles, AgNPs detection and discrimination were achieved based on the signature SERS response of AgNPs-ferbam complexes. SERS response with ferbam was distinct for silver ions, silver chloride, silver bulk particles, and AgNPs. Two types of AgNPs with different coatings, citrate and polyvinylpirrolidone (PVP), both showed strong interactions with ferbam and induced strong SERS signals. SERS was effectively applicable for detecting Ag particles ranging from 20 to 200 nm, with the highest signal intensity in the 60-100 nm range. A linear relationship (R(2) = 0.9804) between Raman intensity and citrate-AgNPs concentrations (60 nm; 0-20 mg/L) indicates the potential for particle quantification. We also evaluated SERS detection of AgNPs in four commercially available antimicrobial products. Combined with ICP-MS and TEM data, the results indicated that the SERS response is primarily dependent on size, but also affected by AgNPs concentration. The findings demonstrate that SERS is a promising analytical platform for studying environmentally relevant levels of AgNPs in consumer products and related matrices.

Surface-enhanced Raman spectroscopy (SERS) using Ag nanoparticle films produced by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Smyth, C.A., E-mail: smythc2@tcd.ie [School of Physics, Trinity College Dublin, Dublin 2 (Ireland); Mirza, I.; Lunney, J.G.; McCabe, E.M. [School of Physics, Trinity College Dublin, Dublin 2 (Ireland)

2013-01-01

Highlights: Black-Right-Pointing-Pointer Pulsed laser deposition (PLD) produces silver nanoparticle films. Black-Right-Pointing-Pointer These films can be used for surface-enhanced Raman spectroscopy (SERS). Black-Right-Pointing-Pointer Commercial film shows good SERS reproducibility but poor signal intensity. Black-Right-Pointing-Pointer PLD shows a good SERS response coupled with good reproducibility. - Abstract: Thin silver nanoparticle films, of thickness 7 nm, were deposited onto glass microslides using pulsed laser deposition (PLD). The films were then characterised using UV-vis spectroscopy and scanning transmission electron microscopy before Rhodamine 6G was deposited onto them for investigation using surface-enhanced Raman spectroscopy (SERS). The sensitivity obtained using SERS was compared to that obtained using a colloidal silver suspension and also to a commercial SERS substrate. The reproducibility of the films is also examined using statistical analysis.

Pensar la arqueología desde el ser nasa-académico dentro del territorio Nasa

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Juan Carlos Piñacué Achicué

2013-10-01

Full Text Available El presente texto emerge desde el lenguaje del ser nasa como antropólogo, de allí, se reflexiona la concepción nasa sobre las huellas de debajo de la tierra, riquezas o bienes arqueológicos (recursos para el aparato gubernamental y piezas u objetos arqueológicos para los arqueólogos. Al intentar ver estas acepciones en conjunto, se presenta la ausencia de unidad de criterios para la construcción de una verdadera agenda arqueológica con “indígenas” en. Esta divergencia se hace inevitable porque existe un parámetro jurídico que opera sobre cada una de las nociones en mención. En síntesis, se vislumbra un poco el panorama que subyace de las posiciones enfrentadas y que al establecer un dialogo horizontal, es posible una arqueología colombiana que mire mas allá de un museo y se construya una política integral.

SERS study of transformation of phenylalanine to tyrosine under particle irradiation

Science.gov (United States)

Zhang, Jingjing; Huang, Qing; Yao, Guohua; Ke, Zhigang; Zhang, Hong; Lu, Yilin

2014-08-01

Surface enhanced Raman scattering or spectroscopy (SERS) is a very powerful analytical tool which has been widely applied in many scientific research and application fields. It is therefore also very intriguing for us to introduce SERS technique in the radiobiological research, where in many cases only a very few of biomolecules are subjected to changes which however can lead to significant biological effects. The radiation induced biochemical reactions are normally very sophisticated with different substances produced in the system, so currently it is still a big challenge for SERS to analyze such a mixture system which contains multiple analytes. In this context, this work aimed to establish and consolidate the feasibility of SERS as an effective tool in radiation chemistry, and this purpose, we employed SERS as a sensitive probe to a known process, namely, the oxidation of phenylalanine (Phe) under particle irradiation, where the energetic particles were obtained from either plasma discharge or electron-beam. During the irradiation, three types of tyrosine (Tyr), namely, p-Tyr, m-Tyr and o-Tyr were produced, and all these tyrosine isomers together with Phe could be identified and measured based on the SERS spectral analysis of the corresponding enhanced characteristic signals, namely, 1002 cm-1 for Phe, 1161 cm-1 for p-Tyr, 990 cm-1 for m-Tyr, and 970 cm-1 for o-Tyr, respectively. The estimation of the quantities of different tyrosine isomers were also given and verified by conventional method such as high performance liquid chromatography (HPLC). As for comparison of different ways of particle irradiation, our results also indicated that electron-beam irradiation was more efficient for converting Phe into Tyr than plasma discharge treatment, confirming the role of hydroxyl radicals in the Phe-Tyr conformation. Therefore, our work has not only demonstrated that SERS can be successfully applied in the radiobiological study, but also given insights into the

A practicable detection system for genetically modified rice by SERS-barcoded nanosensors.

Science.gov (United States)

Chen, Kun; Han, Heyou; Luo, Zhihui; Wang, Yanjun; Wang, Xiuping

2012-04-15

Since the global cultivation of genetically modified crops constantly expands, it remains a high demand to establish different ways to sort food and feed that consist or contain genetically modified organisms. Surface-enhanced Raman scattering (SERS) spectroscopy is a flexible tool for biological analysis due to its excellent properties for detecting wide varieties of target biomolecules including nucleic acids. In the present study, a SERS-barcoded nanosensor was developed to detect Bacillus thuringiensis (Bt) gene-transformed rice expressing insecticidal proteins. The barcoded sensor was designed by encapsulation of gold nanoparticles with silica and conjugation of oligonucleotide strands for targeting DNA strands. The transition between the cry1A(b) and cry1A(c) fusion gene sequence was used to construct a specific SERS-based detection method with a detection limit of 0.1 pg/mL. In order to build the determination models to screen transgene, a series mixture of Bt rice and normal rice were prepared for SERS assay, and the limit of detection was 0.1% (w/w) transgenic Bt rice relative to normal rice. The sensitivity and accuracy of the SERS-based assay was comparable with real-time PCR. The SERS-barcoded analytical method would provide precise detection of transgenic rice varieties but also informative supplement to avoid false positive outcomes. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

Juan O’Gorman. Formas de no ser arquitecto

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Javier Jerez González

2015-12-01

Full Text Available La obra proyectada y construida por Juan O’Gorman a lo largo de su vida traza un recorrido largo y sincopado entre formas de entender la arquitectura totalmente antagónicas. Su primera etapa de radical racionalismo desarrolla, según procedimientos estrictamente técnicos, un lenguaje revolucionario basado en la austeridad y la precisión. A pesar de ello muchas de sus obras destacan por la plasticidad de sus composiciones volumétricas, la riqueza espacial o, incluso, por la creación de atmósferas oníricas. Los primeros años de frenética actividad dan paso a un periodo de voluntario alejamiento de la práctica profesional de la arquitectura: ni una sola obra, ni un solo proyecto durante cerca de 15 años. Tan solo su actividad docente le mantiene en contacto con el mundo de la arquitectura. Cuando Juan O’Gorman vuelve a ejercer como arquitecto, lo hace construyendo algunos de los iconos del movimiento de integración plástica de México: la biblioteca central de la UNAM y su casa en San Jerónimo. A pesar de las enormes diferencias, o más bien oposiciones, entre unos momentos y otros, puede identificarse una invariante clara como señal de identidad personal: una velada voluntad de no ser arquitecto

Starting points for the reference path in the evaluation of the SER Energy Agreement for Sustainable Growth; Uitgangspunten voor het referentiepad bij de evaluatie van het SER-energieakkoord

Energy Technology Data Exchange (ETDEWEB)

Koelemeijer, R.; Verdonk, M. [Planbureau voor de Leefomgeving PBL, Den Haag (Netherlands); Van Dril, T.; Seebregts, A. [ECN Beleidsstudies, Amsterdam (Netherlands)

2013-09-01

The effect of the measures from the SER (Social and Economic Council of the Netherlands) energy agreement on energy, renewable energy and greenhouse gas emissions is assessed by ECN and PBL in relation to the so-called SER-reference path. This paper provides an overview of the assumptions for this reference path with regard to policy, macro-economic development, demography and energy prices and the CO2 price and gives the effect on the price for electricity [Dutch] Het effect van de maatregelen uit het SER-energieakkoord op energiegebruik, hernieuwbare energie en broeikasgasemissies is door ECN en PBL geraamd ten opzichte van het z.g. SER-referentiepad. Deze notitie geeft een overzicht van de gehanteerde uitgangspunten voor dit referentiepad ten aanzien van beleid, macro-economische groei, demografie en energie- en de CO2-prijs en geeft het effect daarvan op de elektriciteitsprijs.

Tatuajes y su eliminación por láser

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T. Castro

Full Text Available La eliminación de los tatuajes con buen resultado cosmético ha sido una inquietud mantenida durante siglos. La introducción del tratamiento láser ha supuesto un avance importante de cara a obtener buenos resultados con mínimos efectos secundarios. En este trabajo se exponen los diferentes tipos de tatuajes con sus características de pigmento, origen, tipos de tratamientos para su eliminación, y entre ellos, la utilización de la tecnología láser, más concretamente de los láseres de emisión en Q-Switch con sus ventajas y limitaciones. Presentamos también los avances y el futuro de la aplicación del láser en el tratamiento de los tatuajes.

Condiciones sociales en torno al suicidio en la región occidental de El Salvador.

OpenAIRE

Serreño Menéndez, Ángel Fredi

2011-01-01

Definición de suicidio -- Antigüedad clásica: Algunos abordajes acerca de la moralidad del suicidio -- El suicidio en la Edad Media: Satanás y las sanciones de la Iglesia -- El Renacimiento y la popularización del suicidio -- Ser o no ser, ésa es la cuestión”: Un debate filosófico -- Suicidio en el siglo XVII: Con una legitimación del suicidio -- Iluminismo: Apología y hostilidad al suicidio -- El suicidio en el siglo XIX: la culpabilización del suicidio -- El suicidio en el siglo XX: Nuevas ...

Adherencia al tratamiento en mujeres con diagnóstico de fibromialgia y los factores asociados

OpenAIRE

Betancourt Santamaria, Belsy Yohana; Gallego Gómez, María Elena

2016-01-01

La Fibromialgia (FM) es una enfermedad que en los últimos años ha aumentado su prevalencia en la población mundial (2%). En Colombia, no se encuentra registro de prevalencia oficial por parte del sistema de Salud, a pesar de ser una enfermedad crónica que cada vez es más común sobre todo en mujeres. En el caso de la FM por ser una enfermedad crónica, la adherencia a los tratamientos juega un papel muy importante para el control de síntomas Objetivo. Determinar el nivel de adherencia al tra...

SERS Raman Sensor Based on Diameter-Modulated Sapphire Fiber

Energy Technology Data Exchange (ETDEWEB)

Shimoji, Yutaka

2010-08-09

Surface enhanced Raman scattering (SERS) has been observed using a sapphire fiber coated with gold nano-islands for the first time. The effect was found to be much weaker than what was observed with a similar fiber coated with silver nanoparticles. Diameter-modulated sapphire fibers have been successfully fabricated on a laser heated pedestal growth system. Such fibers have been found to give a modest increase in the collection efficiency of induced emission. However, the slow response of the SERS effect makes it unsuitable for process control applications.

O cotidiano do ser-adolescendo com aids: movimento ou momento existencial?

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Cristiane Cardoso de Paula

Full Text Available As crianças com AIDS por transmissão vertical transitam da infância para adolescência, e pouco se sabe sobre como cuidam de si. Compreender este cotidiano do adolescer foi o objetivo desta investigação fenomenológica com análise hermenêutica heideggeriana. A entrevista com 11 meninos/meninas (12-14 anos não institucionalizados, que conheciam seu diagnóstico, ocorreu depois da aprovação do projeto pelo Comitê de Ética de três instituições do Rio de Janeiro, cenários da pesquisa. Os resultados apontaram um cotidiano marcado pelos momentos infância e adolescência. Às vezes quer voltar a ser-criança para brincar; se re-conhece como ser-adolescente pela aparência, humor, atividades diárias, lazer e relacionamentos. Transitando entre esses momentos, re-vela-se como ser-adolescendo. Neste movimento existencial des-vela-se como ser-de-possibilidades, que não está limitado à dupla-facticidade: adolescer (segundo demarcações etárias e características predeterminadas e AIDS (fragilidade clínica. Portanto, conjugar as dimensões biológica e existencial, no modelo assistencial-institucional, é o desafio do cuidado ao ser-adolescendo.

Cirugía refractiva láser corneal LASIK vs PRK en miopía baja, media y elevada

OpenAIRE

Hurtado Sánchez, Esther

2011-01-01

El propósito de este trabajo es comparar los resultados, en cuanto a eficacia y seguridad, de las dos técnicas de cirugía refractiva láser más utilizadas actualmente, como son PRK y LASIK. Para ello, y haciendo uso de una revisión bibliográfica, se han escogido una serie de estudios donde se valoraban los resultados de las dos técnicas anteriormente mencionadas en cuanto a agudeza visual, sensibilidad al contraste, cambios en las aberraciones, y cambios fisiólogicos a nivel corneal, así como ...

Análisis de datos con Excel: Una herramienta al alcance de todos.

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M. L. Martínez Romero

2000-01-01

Full Text Available En la actualidad, cualquier alumno puede disponer de un ordenador y del paquete Microsoft office, el cual incorpora un módulo de herramientas para análisis de datos. Elegimos dicho programa por varias razones, en primer lugar por su facilidad de manejo, en segundo por ser utilizado en la asignatura Informática Aplicada a la Gestión de la Empresa y por último por ser uno de los programas de más uso en la empresa hoy en día. El objetivo de dicha práctica era que el alumno resolviese un problema estadístico de actualidad utilizando como soporte informático el programa Excel, y a partir de los resultados obtenidos, comprender la información y usarla eficazmente. Al finalizar la práctica se pasó una encuesta a los alumnos para medir la consecución de los objetivos a conseguir, así como su nivel de satisfacción. Los resultados obtenidos los presentamos al final del trabajo.

Narrativas do envelhecimento: ser velho na sociedade contemporânea

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Sofia Aboim

2014-06-01

Full Text Available Com base em entrevistas realizadas a homens e mulheres com mais de 65 anos de idade residentes em Portugal, procura-se elaborar um retrato do que significa ser velho e de qual o impacto do processo de envelhecimento na vida e na identidade da pessoa idosa. Partindo do pressuposto de que, não obstante a maior regulação da idade na sociedade contemporânea, existe grande diversidade nas formas de viver a velhice, mobiliza-se uma perspectiva microssociológica de análise, na primeira pessoa, dos discursos sobre o envelhecimento. Além de diferenças de gênero e de estatuto social, a população idosa revela um relativo conformismo com a velhice, enquanto algo que é natural. Porém, algumas dimensões surgem como problemáticas para a identidade do idoso: o declínio do corpo e da saúde, a sexualidade, a perda de atividade, o isolamento e a discriminação social são dimensões particularmente relevantes para conceituar a pessoa idosa como ator reflexivo e portador de reflexividade.

Generation Y : salutogenes unternehmerisches Engagement und Work-Life-Balance Maßnahmen als Auslöser affektiven Mitarbeiter-Commitments

OpenAIRE

Fischer, Jennifer

2013-01-01

In einem Artikel der Zeitschrift Die Zeit wird die Generation Y, die Generation deren Angehörige derzeit zum Großteil ihre akademische Ausbildung beenden und sich dem Arbeitsmarkt zuwenden, auch als Generation Pippi, angelehnt an Astrid Lindgrens Kinderbuchheldin Pippi Langstrumpf, bezeichnet (Bund et al., 2013: 1). Individualität, eine ausgeprägte Abneigung gegenüber Autoritätspersonen, der Wunsch nach Spaß und Abwechslung sowie das Bestreben, sich selbst zu verwirklichen, charakterisieren P...

INTERVENCIÓN PARA REDUCIR EL TRASTORNO DE ANSIEDAD ASOCIADO AL TDA/TDAH

OpenAIRE

García-Fernández, Laura

2012-01-01

El trastorno por déficit de atención con o sin hiperactividad es abordado aquí valorando la comorbilidad asociada al mismo. Principalmente nos centramos en el trastorno de ansiedad por ser uno de los más frecuentes dentro de este grupo. Además de dar a conocer la sintomatología de ambas problemáticas y la relación que entre ellas existe, se propone un programa de intervención dirigido a la infancia, para disminuir la ansiedad asociada al TDAH. Para llegar a este punto primero se realiza un re...

Ambiguidade: modo de ser da mulher na prevenção secundária do câncer de mama Ambigüedad: modo de ser de la mujer en la prevención secundaria del cancer de mama Ambiguity: woman's manner of being in the secondary prevention of the breast cancer

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Maria Carmen Simões Cardoso de Melo

2012-03-01

Full Text Available A magnitude do câncer de mama impõe valorizar o saber e agir diante da doença e sua detecção precoce. Neste estudo, de natureza qualitativa, norteado pela fenomenologia e fundado no pensamento teórico-metodológico de Martin Heidegger, buscouse ouvir o ser-mulher-que-pertence-ao-grupo-de-risco-familiar, com o objetivo de analisar compreensivamente seus significados de prevenção secundária. Mediante relação empática e redução de pressupostos, entrevistaram-se 13 mulheres indicadas por suas familiares clientes. A hermenêutica possibilitou a compreensão interpretativa do ser-aí, que mostrou facetas de sua dimensão existencial. Regida pelo falatório e temor, sob o domínio da ambiguidade, não se reconhece como ser de possibilidades. Carece melhor compreensão para movimentar-se para a de-cisão pela prevenção secundária. A construção do conceito de ser e o desvelamento do sentido podem alicerçar a prática assistencial do enfermeiro e favorecer o cuidado singular, integral e humano, que privilegia o ouvir atento ao vivido do ser-mulher, em seu movimento existencial de in-compreensões e indagações.La magnitud del cáncer de mama impone valorar el saber y actuar frente a la enfermedad y su detección precoz. En este estudio, de naturaleza cualitativa, norteado por la fenomenología y fundado en el pensamiento teórico-metodológico de Martin Heidegger, se buscó oír el ser-mujer-que-pertenece-al-grupode-riesgo-familiar, con el objetivo de analizar comprensivamente sus significados de prevención secundaria. Mediante relación empática y reducción de presupuestos, se entrevistaron trece mujeres indicadas por sus familiares clientes. La hermenéutica posibilitó la comprensión interpretativa del ser-ahí, que mostró facetas de su dimensión existencial. Regida por el parlatorio y temor, bajo el dominio de la ambigüedad, no se reconoce como ser de posibilidades. Carece mejor comprensión para moverse para la de

Acerca de tres dimensiones del ser humano

OpenAIRE

Fúnez, Rubén

2007-01-01

El autor resume las ideas importantes del libro "Tres dimensiones del ser humano", se pregunta por la importancia del planteamiento zubiriano, tanto para la historia de la filosofía, como para la situación que actualmente nos ha tocado vivir.

SERS Detection of Penicillin G Using Magnetite Decorated with Gold Nanoparticles

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Paula C. Pinheiro

2017-10-01

Full Text Available Sensitive and reliable procedures for detecting vestigial antibiotics are of great relevance for water quality monitoring due to the occurrence of such emergent pollutants in the aquatic environment. As such, we describe here research concerning the use of multifunctional nanomaterials combining magnetic and plasmonic components. These nanomaterials have been prepared by decorating magnetite nanoparticles (MNP with colloidal gold nanoparticles (Au NPs of distinct particle size distributions. Several analytical conditions were investigated in order to optimize the surface enhanced Raman scattering (SERS detection of penicillin G (PG dissolved in water. In particular, the dependence of the SERS signal by using distinct sized Au NPs adsorbed at the MNP was investigated. Additionally, microscopic methods, including Raman confocal microscopy, were employed to characterize the SERS substrates and then to qualitatively detect penicillin G using such substrates. For example, magnetic–plasmonic nanocomposites can be employed for magnetically concentrate analyte molecules and their removal from solution. As a proof of concept, we applied magneto-plasmonic nanosorbents in the removal of aqueous penicillin G and demonstrate the possibility of SERS sensing this antibiotic.

Evolución del cuidado desde una práctica ancestral hasta ser la esencia del profesional de enfermería

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Mirith Vásquez Munive

2013-10-01

Full Text Available Cuidar ha sido desde tiempos inmemoriales una capacidad inherente e identificativa del sexo femenino, que se extendió al generó masculino en el momento de la división sexual del trabajo; en este punto nació una forma de cuidar diferente, de acuerdo a las capacidades físicas de cada cual, y a las labores que hasta ese momento habían sido la responsabilidad de hombres por un lado y mujeres por el otro. Significa esto que hay varias formas de cuidar, cada una dependiendo de las características individuales de la vida de cada ser humano, pero todos, absolutamente todos tenemos la capacidad de cuidar. Luego, cuando fue necesario, que una persona se encargara de preservar la salud de los individuos de la comunidad, y adoptara medidas curativas, apareció la mujer como cuidadora, por la sapiencia acumulada a través de la observación de la naturaleza, que la dotó de un bagaje de conocimientos que no poseía ningún otro ser diferente a ella. Aquí surgió la mujer como cuidadora natural, empírica, y pragmática, y con el paso del tiempo llegó a la mujer preparada académicamente, para brindar un cuidado, organizado de acuerdo al conocimiento científico, es decir hasta la enfermera del día de hoy, ampliamente preparada para brindar cuidado de calidad. (Duazary 2006; 1: 76 - 80.

[Preparation of a kind of SERS-active substrates for spot fast analysis].

Science.gov (United States)

Ji, Nan; Li, Zhi-Shi; Zhao, Bing; Zou, Bo

2013-02-01

A kind of SERS-active substrates was prepared using chemical self-assembly method, aiming at spot fast analysis using portable Raman spectrometer. PDDA was first absorbed on the inner wall of vials, and then Ag colloids were assembled on the inner wall. UV-Vis spectra and Raman spectra of two kinds of blank vials were investigated and the transparent vials were thought to be better for SERS-vials. UV-Vis spectra were used to monitor the assembly process of Ag colloids. SERS activity of our substrates was characterized using p-ATP as probing molecules.

Electrodeposited Silver Nanoparticles Patterned Hexagonally for SERS

International Nuclear Information System (INIS)

Gu, Geun Hoi; Lee, Sue Yeone; Suh, Jung Sang

2010-01-01

We have fabricated hexagonally patterned silver nanoparticles for surface-enhanced Raman scattering (SERS) by electrodepositing silver on the surface of an aluminum plate prepared by completely removing the oxide from anodic aluminum oxide (AAO) templates. Even after completely removing the oxide, well-ordered hexagonal patterns, similar to the shape of graphene, remained on the surface of the aluminum plate. The borders of the hexagonal pattern protruded up to form sorts of nano-mountains at both the sides and apexes of the hexagon, with the apexes protruding even more significantly than the sides. The aluminum plate prepared by completely removing the oxide has been used in the preparation of SERS substrates by sputter-coating of gold or silver on it. Instead of sputter-coating, here we have electro-deposited silver on the aluminum plate. When silver was electro-deposited on the plate, silver nanoparticles were made along the hexagonal margins.

Instaurando maneiras de ser, conhecer e interpretar

Directory of Open Access Journals (Sweden)

Maria Stephanou

1998-01-01

Full Text Available O artigo propõe a discussão e a problematização do tema "currículo e história". Na primeira parte explicita os fundamentos propostos para a abordagem, as concepções de currículo e história. Na segunda, privilegia as indicações de autores e a experiência pessoal para: a caracterizar o que têm sido os currículos e o ensino de história, particularmente no ensino fundamental, comentan-do suas implicações; b examinar alternativas e encaminhamentos propostos pelos debates da atualidade. Sugere que a aprendizagem de conteúdos históricos na escola, para além da mera aquisição de informações, implica a produção ativa de subjetividades, ou maneiras de ser, conhecer e interpretar o mundo e a si próprio.This article proposes to discuses and to question the theme "curriculum & history". On first part, it explains the fundaments proposed to the dissertation, the conception of curriculum & history. On the second, it grants privilege upon authors remarks and personal experience for purpose to: a characterize what were the curricular activities and the teaching of history, inside primary school particularly, with comments about its implications. b examine alternatives and forwarding proposed by present debates. It suggests that in the school the apprenticeship around historical contents, other than a pure acquisition of information, implies and actives production of subjectivities or manners of being, knowing and interpreting the world and oneself.

Flexible SERS Substrates: Challenges and Opportunities

Science.gov (United States)

2016-01-28

are still widely used due to the ease with which silver and gold nanoparticles can be produced. Nanoparticle inks are colloidal suspensions of...interactions between the analyte, silver nanoparticles, and a salt. This system has also been applied to detection of trace antibiotics for food safety...Cleanable SERS Substrates Based on Silver Nanoparticle Decorated Electrospun Nano-fibrous Membranes Chaoyang Jiang Porous electrospun nanofibrous

Los trastornos temporomandibulares y la radiación láser Temporomandibular disorders and the application of laser therapy.

Directory of Open Access Journals (Sweden)

Ileana Grau León

2007-09-01

Full Text Available Los trastornos temporomandibulares constituyen un problema de salud mundial. Estudios epidemiológicos en relación con su prevalencia indican que más del 50 % de la población ha padecido de signos y síntomas relacionados con esta patología, entre los que se encuentran ruidos, dolor articular y limitación al movimiento. El grupo de estudio estuvo constituido por 40 pacientes con trastornos de la articulación temporomandibular (ATM, de ambos sexos y mayores de 20 años, que acudieron a consulta en la Facultad de Estomatología de La Habana. El diagnóstico se estableció por el interrogatorio y el examen clínico. Para la obtención de los datos se creó un formulario con el objetivo de evaluar la eficacia del uso del miniláser en la terapia de los trastornos de la ATM, evaluar la evolución de intensidad dolorosa presente, antes y después del tratamiento con láser y tratamiento farmacológico, así como determinar el número de aplicaciones necesarias para el alivio total o parcial del dolor y músculo con mayor afectación. La aplicación de la técnica se realizó en 2 grupos; el primero recibió terapia farmacológica activa y el segundo terapia láser. Al culminar el tratamiento se evaluaron los casos y se remitieron a la consulta de ATM para el tratamiento definitivo. Los resultados revelaron que el mayor porcentaje de los pacientes tuvo remisión total del dolor con el tratamiento con láser terapia, en relación con los que se trataron con fármacos, al igual que el índice de dolor presente.Temporomandibular Disorders (TMD are a world health problem. Epidemiological studies indicate that over 50% of population has suffered some kind of sign and sympton caused by this pathology like joint sounds, joint pain and restricted movement. The study group was composed by 40 patients of both sexes and over 20 years of age that had come to the dental service of the Faculty of Dentistry in Havana province because of their temporomandibular

[TLC-FT-SERS study on ingredients of Isrhynchophylline].

Science.gov (United States)

Wang, Yuan; Wang, Song-ying; Zhao, Yi-xue; Ren, Gui-fen; Zi, Feng-lan

2002-02-01

A new method for analysing the ingredients of Isrhynchophylline in Uncaria Rhynchophylla Jacks by thin layer chromatography (TLC) and the surface-enhanced Raman spectroscopy (SERS) is reported in this paper. The results show that the characteristic spectra bands of Isrhynchophylline situated at the thin layer with the amount of sample about 2.5 micrograms were obtained. The difference between SERS and solid spectra was found. Great enhancement of the 1,615 cm-1 spectral band was abstained. Molecule was absorbed in surface silver sol by pi electrons in phenyl and by pair of electrons in N together. An absorption model of Isrhynchophylline and silver sol was proposed. This method can be used to analyse the chemical ingredients with high sensitivity.

Ser cuidada por profissionais da saúde: percepções e sentimentos de mulheres que sofreram abortamento

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Kellen Daiane Valandro Bazotti

2009-01-01

Full Text Available El objetivo de la investigación es identificar las percepciones y sentimientos de mujeres que sufrieron aborto, principalmente, las relacionadas al cuidado de profesionales de la salud en un hospital. Es un estudio cualitativo, exploratorio-descriptivo. Los instrumentos para la recolección de los datos fueron: entrevista abierta y registro en el diario de campo. La recolección de los datos se hizo en dos momentos: durante la internación hospitalaria y en los domicilios. Integraron la investigación cinco mujeres que tuvieron aborto espontáneo. Para el análisis de las declaraciones se utilizó el análisis temático, del cual emergió una categoría: "ser cuidada" en un hospital: la visión de mujeres que abortaron, dividida en nueve subcategorías. Varios sentimientos y percepciones fueron mencionados, incluyendo miedo, nerviosismo, tristeza, vergüenza, dolor por la pérdida del hijo, satisfacción con la atención de los profesionales, apoyo, seguridad, entre otros. Esa investigación puede ser una contribución para los profesionales y estudiantes del área de la salud, en el sentido de permitirles reflexionar y darle calidad a la atención.

Parameter optimization for Ag-coated TiO2 nanotube arrays as recyclable SERS substrates

Science.gov (United States)

Sun, Yuyang; Yang, Lulu; Liao, Fan; Dang, Qian; Shao, Mingwang

2018-06-01

The Ag-coated titanium dioxide nanotube arrays (Ag-coated TNTs) are obtained via the deposition of Ag nanoparticles on the two-step anodized TNTs. The wall thickness of TNTs is modulated via finite difference time domain simulation to get the favorable electromagnetic field for surface enhanced Raman scattering (SERS). Ag-coated TNTs with optimal wall thickness of 20 nm were employed as the SERS substrates to detect 2-mercaptobenzoxazole, which show superior detection sensitivity and uniformity. In addition, due to the photocatalysis of TNTs, the SERS substrates could clean themselves and be repeatedly used by photo-degradation of target molecules under the ultra-violet irradiation. The Ag-coated TNTs are a kind of bifunctional SERS substrates which can produce high-quality SERS signals and reuse to reduce the cost.

Aproximación conceptual al “acceso efectivo a la administración de justicia” a partir de la teoría de la acción procesal

Directory of Open Access Journals (Sweden)

Fredy Hernando Toscano López

2013-06-01

Full Text Available La teoría de la acción procesal en su sentido abstracto puede servir de fundamento para la construcción conceptual del derecho fundamental al acceso efectivo a la administración de justicia, puesto que solo bajo dicha concepción es posible afirmar que todo sujeto de derecho, tenga o no la razón desde el punto de vista del derecho sustancial, tiene que ser escuchado en el proceso. Así las cosas, este derecho fundamental deja de ser una simple institución teórica o formalista, para convertirse en un elemento esencial al Estado de derecho, pues legitima al proceso judicial como genuino instrumento institucionalizado de solución pacífica de controversias (heterocomposición, al contribuir con la proscripción de la justicia por mano propia.

El ser humano y sus posibilidades de construcción desde el cuidado

Directory of Open Access Journals (Sweden)

Alacoque Lorenzini Erdmann

2003-01-01

Full Text Available El artículo presenta algunas concepciones del ser humano en relación con el cuidado de enfermería. A partir de la organización de la vida se establecen relaciones, interacciones del ser humano, sus límites y posibilidades para el cuidado con la vida, con lo cotidiano y con la naturaleza. Resalta la importancia y el compromiso en la construcción colectiva del ser ciudadano.

Processing ser and estar to locate objects and events

Science.gov (United States)

Dussias, Paola E.; Contemori, Carla; Román, Patricia

2016-01-01

In Spanish locative constructions, a different form of the copula is selected in relation to the semantic properties of the grammatical subject: sentences that locate objects require estar while those that locate events require ser (both translated in English as ‘to be’). In an ERP study, we examined whether second language (L2) speakers of Spanish are sensitive to the selectional restrictions that the different types of subjects impose on the choice of the two copulas. Twenty-four native speakers of Spanish and two groups of L2 Spanish speakers (24 beginners and 18 advanced speakers) were recruited to investigate the processing of ‘object/event + estar/ser’ permutations. Participants provided grammaticality judgments on correct (object + estar; event + ser) and incorrect (object + ser; event + estar) sentences while their brain activity was recorded. In line with previous studies (Leone-Fernández, Molinaro, Carreiras, & Barber, 2012; Sera, Gathje, & Pintado, 1999), the results of the grammaticality judgment for the native speakers showed that participants correctly accepted object + estar and event + ser constructions. In addition, while ‘object + ser’ constructions were considered grossly ungrammatical, ‘event + estar’ combinations were perceived as unacceptable to a lesser degree. For these same participants, ERP recording time-locked to the onset of the critical word ‘en’ showed a larger P600 for the ser predicates when the subject was an object than when it was an event (*La silla es en la cocina vs. La fiesta es en la cocina). This P600 effect is consistent with syntactic repair of the defining predicate when it does not fit with the adequate semantic properties of the subject. For estar predicates (La silla está en la cocina vs. *La fiesta está en la cocina), the findings showed a central-frontal negativity between 500–700 ms. Grammaticality judgment data for the L2 speakers of Spanish showed that beginners were significantly less

SERS imaging of cell-surface biomolecules metabolically labeled with bioorthogonal Raman reporters.

Science.gov (United States)

Xiao, Ming; Lin, Liang; Li, Zefan; Liu, Jie; Hong, Senlian; Li, Yaya; Zheng, Meiling; Duan, Xuanming; Chen, Xing

2014-08-01

Live imaging of biomolecules with high specificity and sensitivity as well as minimal perturbation is essential for studying cellular processes. Here, we report the development of a bioorthogonal surface-enhanced Raman scattering (SERS) imaging approach that exploits small Raman reporters for visualizing cell-surface biomolecules. The cells were cultured and imaged by SERS microscopy on arrays of Raman-enhancing nanoparticles coated on silicon wafers or glass slides. The Raman reporters including azides, alkynes, and carbondeuterium bonds are small in size and spectroscopically bioorthogonal (background-free). We demonstrated that various cell-surface biomolecules including proteins, glycans, and lipids were metabolically incorporated with the corresponding precursors bearing a Raman reporter and visualized by SERS microscopy. The coupling of SERS microscopy with bioorthogonal Raman reporters expands the capabilities of live-cell microscopy beyond the modalities of fluorescence and label-free imaging. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Phospho-Bcl-xL(Ser62) influences spindle assembly and chromosome segregation during mitosis.

Science.gov (United States)

Wang, Jianfang; Beauchemin, Myriam; Bertrand, Richard

2014-01-01

Functional analysis of a series of phosphorylation mutants reveals that Bcl-xL(Ser62Ala) influences cell entry into anaphase and mitotic exit in taxol-exposed cells compared with cells expressing wild-type Bcl-xL or a series of other phosphorylation mutants, an effect that appears to be independent of its anti-apoptotic activity. During normal mitosis progression, Bcl-xL(Ser62) is strongly phosphorylated by PLK1 and MAPK14/SAPKp38α at the prometaphase, metaphase, and the anaphase boundaries, while it is de-phosphorylated at telophase and cytokinesis. Phospho-Bcl-xL(Ser62) localizes in centrosomes with γ-tubulin and in the mitotic cytosol with some spindle-assembly checkpoint signaling components, including PLK1, BubR1, and Mad2. In taxol- and nocodazole-exposed cells, phospho-Bcl-xL(Ser62) also binds to Cdc20- Mad2-, BubR1-, and Bub3-bound complexes, while Bcl-xL(Ser62Ala) does not. Silencing Bcl-xL expression and expressing the phosphorylation mutant Bcl-xL(Ser62Ala) lead to an increased number of cells harboring mitotic spindle defects including multipolar spindle, chromosome lagging and bridging, aneuploidy with micro-, bi-, or multi-nucleated cells, and cells that fail to resolve undergo mitosis within 6 h. Together, the data indicate that during mitosis, Bcl-xL(Ser62) phosphorylation impacts on spindle assembly and chromosome segregation, influencing chromosome stability. Observations of mitotic cells harboring aneuploidy with micro-, bi-, or multi-nucleated cells, and cells that fail to resolve undergo mitosis within 6 h were also made with cells expressing the phosphorylation mutant Bcl-xL(Ser49Ala) and dual mutant Bcl-xL(Ser49/62Ala).

Improved size-tunable synthesis and SERS properties of Au nanostars

Science.gov (United States)

Khlebtsov, Boris; Panfilova, Elizaveta; Khanadeev, Vitaly; Khlebtsov, Nikolai

2014-10-01

Multibranched Au nanoparticles with sharp tips (commonly called nanostars, NSTs) have attracted significant attention as bright scattering labels, photothermal transducers, nanocarriers, and surface-enhanced Raman scattering (SERS) tags. However, for surfactant-free synthesized NSTs, the existing data on the size tuning and the relation between the size of NSTs and their SERS efficiency still remain limited. Here, we address these questions by synthesizing and comparing SERS for surfactant-free NSTs of different sizes and plasmon resonance (PR) wavelengths. The NSTs were fabricated by seeded growth through a two-step surfactant-free approach in which quasispherical seeds were overgrown via reduction of added Au by ascorbic acid in the presence of Ag ions. By varying the seed size from 3 to 35 nm, we tuned the final NST size from 45 to 150 nm while retaining the star-like morphology with sharp tips and ensuring PR tunability from 630 to 900 nm. The NST size and PR limits can be expanded from 40 to 200 nm and from 600 to 930 nm, respectively, by simultaneous variation in the seed size and concentration. The SERS efficiency of the fabricated NSTs was examined by Raman measurements of 1,4-aminothiophenol (ATP) adsorbed on the surface of colloidal NST particles. Although the homogenous analytical enhancement factor (AEF) did not depend essentially on the NST size and varied from 4 × 106 to 107, the enhancing properties of single-particle NST tags were strongly size-dependent. Specifically, the AEF for 150-nm NST35-ATP complexes was 30 and 100 times greater than that for 70-nm NST15-ATP and 45-nm NST3-ATP complexes, respectively. These properties make the NST-ATP complex a prospective platform for SERS imaging.

Modificación superficial de aceros y hierros fundidos mediante láser de Nd: YAG. // Steels and cast irons superficial modification by means of laser Nd: YAG.

Directory of Open Access Journals (Sweden)

R. Sagaró Z.

2001-10-01

Full Text Available Se presentan los resultados de los autores en el tratamiento térmico superficial con técnica láser (TTSL. Con el empleo deun láser de Nd: YAG se procedió al endurecimiento superficial de los aceros AISI 1045, W1, W112 y hierros fundidos detipo laminar y nodular. Los autores prestan atención a las rutas de endurecimiento superficial atendiendo a los parámetrosoperacionales del láser: potencia incidente en la zona de interacción (P y la velocidad de barrido del haz de láser (V. Deigual forma se establecen valoraciones acerca de las estructuras metalográficas obtenidas. En todos los casos se reportanvalores de microdureza Vickers que oscilan entre los 500-900 HV (incrementos de 3-4 veces respecto al substratooriginal. Los resultados obtenidos permiten establecer en todos los casos experimentados que el incremento de lavelocidad de barrido provocó una disminución de la profundidad de la capa endurecida. Las experiencias del TTSL en losaceros ensayados muestran una tendencia a la disminución de la profundidad del endurecimiento con el incremento delcontenido de carbono.Palabras claves: Endurecimiento superficial, parámetros de operación de láser., microdureza, profundidadde capa endurecida, de fallo, vibraciones.____________________________________________________________________________AbstractThis paper expose the experiences of researchers on the laser surface heat treatment. The hardening of AISI 1045, W1,W112 steels and cast irons flake and nodular was carried out by using a Nd: YAG laser. Operation parameters of laser, likebeam power (P and traverse speed of the laser spot (V are closely with hardening depth . Authors present some analysesabout metallographic studies. In all cases are reported Vickers microhardness about 500-900 HV (three or four times higherthan original substrates. Relations between microhardness and depth of hardening are presented for the processedmaterials. Experimental results showed that the increased

Fabrication of large-area self-organizing gold nanostructures on a porous Al2O3 template for application as a SERS-substrate

DEFF Research Database (Denmark)

Nielsen, Peter; Hassing, Søren; Albrektsen, Ole

A new technique for fabrication of large-area self-organizing variably ordered gold nanostructures with sub-10 nm gaps on templates of hexagonally ordered porous anodic aluminum oxide is demonstrated. The size as well as the interparticle distance of the fabricated gold nanostructures are adjusted...... by application of various electrolytes used in anodization of the aluminum template and the thickness of gold sputter-coated on the pore layer. The fabricated substrates are characterized by SEM, and the applicability as SERS substrates is investigated by adsorption of rhodamine 6G on the nanostructures...

Self-catalytic stabilized Ag-Cu nanoparticles with tailored SERS response for plasmonic photocatalysis

Science.gov (United States)

He, Lili; Liu, Changqing; Tang, Jia; Zhou, Youchen; Yang, Hui; Liu, Ruiyu; Hu, Jiugang

2018-03-01

In-situ SERS monitoring of direct plasmon-driven photocatalysis was achieved using relatively earth-abundant Cu NPs following their decoration with tiny amounts of silver, which promoted excellent SERS and high catalytic activity. The SERS and catalytic performance of the Ag-Cu NPs can be tuned by changing their composition. In particular, it was found that the surface oxidation state of copper could be switched to its metallic state via self-plasmon catalysis under laser irradiation, highlighting the potential of air-unstable copper NPs as stable plasmonic catalysts. These dual functional Ag-Cu NPs were used for SERS real-time monitoring of plasmon-driven photocatalysis reactions involving the degradation of Rhodamine 6G and the dimerization of 4-nitrothiophenol. The corresponding catalytic reaction mechanisms were discussed.

A Widely Applicable Silver Sol for TLC Detection with Rich and Stable SERS Features

Science.gov (United States)

Zhu, Qingxia; Li, Hao; Lu, Feng; Chai, Yifeng; Yuan, Yongfang

2016-04-01

Thin-layer chromatography (TLC) coupled with surface-enhanced Raman spectroscopy (SERS) has gained tremendous popularity in the study of various complex systems. However, the detection of hydrophobic analytes is difficult, and the specificity still needs to be improved. In this study, a SERS-active non-aqueous silver sol which could activate the analytes to produce rich and stable spectral features was rapidly synthesized. Then, the optimized silver nanoparticles (AgNPs)-DMF sol was employed for TLC-SERS detection of hydrophobic (and also hydrophilic) analytes. SERS performance of this sol was superior to that of traditional Lee-Meisel AgNPs due to its high specificity, acceptable stability, and wide applicability. The non-aqueous AgNPs would be suitable for the TLC-SERS method, which shows great promise for applications in food safety assurance, environmental monitoring, medical diagnoses, and many other fields.

[Study on the ingredients of reserpine by TLC-FT-SERS].

Science.gov (United States)

Wang, Y; Zi, F; Wang, Y; Zhao, Y; Zhang, X; Weng, S

1999-12-01

A new method for analysing the ingredients of reserpine by thin layer chromatography (TLC) and surface-enhanced Raman spectroscopy (SERS) is reported in this paper. The results show that the characteristic spectral bands of reserpine satuated at the thin layer with the amount of sample about 2 microg were obtained. The difference between SERS and solid spectra was found. An absorption model of reserpine and silver sol was proposed. This method can be used to analyse the chemical ingredients with high sensitivity.

New nanocomposites for SERS studies of living cells and mitochondria

DEFF Research Database (Denmark)

Sarycheva, A. S.; Brazhe, N. A.; Baizhumanov, A. A.

2016-01-01

A great enhancement in Raman scattering (SERS) from heme-containing submembrane biomolecules inside intact erythrocytes and functional mitochondria is demonstrated for the first time using silver–silica beads prepared using a new method involving aerosol pyrolysis with aqueous diamminesilver...... molecules. The SERS spectra of functional mitochondria are sensitive to the activity of the mitochondrial electron transport chain, thus making the method a novel label-free approach to monitor the redox state and conformation of cytochromes in their natural cell environment. The developed nanocomposites...

Requisitos e impedimentos para ser árbitro en el derecho español

Directory of Open Access Journals (Sweden)

Marcela Rodríguez Mejía

2011-06-01

Full Text Available La ley española de arbitraje, Ley 60 de 2003, contempla en distintos artículos los requisitos legales que debe reunir todo aquel que pretenda ser árbitro en una controversia regida por la misma, así como también, aquellas situaciones que de presentarse, les impedirán obrar como tal. Al mismo tiempo, y en consonancia con la prevalencia que da a la autonomía de la voluntad de las partes, el legislador español permitió que éstas acuerden otros requisitos a los futuros árbitros. Así las cosas, el artículo analiza, de forma crítica, los requisitos e impedimentos legales a los árbitros bajo el marco de la ley, el fundamento e importancia de que las partes a su vez determinen otros requisitos, así como también, el momento en el que se espera se cumplan los mismos.

Requisitos e impedimentos para ser árbitro en el derecho español

Directory of Open Access Journals (Sweden)

Marcela Rodríguez Mejía

2011-07-01

Full Text Available La ley española de arbitraje, Ley 60 de 2003, contempla en distintos artículos los requisitos legales que debe reunir todo aquel que pretenda ser árbitro en una controversia regida por la misma, así como también, aquellas situaciones que de presentarse, les impedirán obrar como tal. Al mismo tiempo, y en consonancia con la prevalencia que da a la autonomía de la voluntad de las partes, el legislador español permitió que éstas acuerden otros requisitos a los futuros árbitros. Así las cosas, el artículo analiza, de forma crítica, los requisitos e impedimentos legales a los árbitros bajo el marco de la ley, el fundamento e importancia de que las partes a su vez determinen otros requisitos, así como también, el momento en el que se espera se cumplan los mismos.

Modos de ser enfermeiro-professor-no-ensino-do-cuidadode-enfermagem: um olhar heideggeriano

Directory of Open Access Journals (Sweden)

Luciara Fabiane Sebold

2013-08-01

Full Text Available Estudo qualitativo de abordagem fenomenológica. Objetivou desvelar, à luz do pensamento de Martin Heidegger, os modos de ser dos enfermeiros-professores na vivência de ensinar-aprender o cuidado de enfermagem em uma instituição federal de ensino superior do sul do Brasil. A técnica utilizada para captar os significados foi a entrevista fenomenológica com 11 docentes. A análise permitiu compreender os Modos de Ser enfermeiro-professor, que foram didaticamente apresentados em duas unidades de significado: Modo de ser enfermeiro para o cuidado; Modo de ser professor para o ensino do cuidado. Alguns professores identificam-se como enfermeiros, suas experiências profissionais são suas bases e a coexistência com outros pôde lhes servir de exemplo. Outros se percebem professores de enfermagem e desejam ensinar os desafios de ser enfermeiro, e aprimoram o cuidado através de pesquisas. Ao ensinar, envolvem-se com o universo de ensino no qual o cuidar também é aprender e ensinar.

Apps y gestión de marca ¿es indispensable ser mobile?

Directory of Open Access Journals (Sweden)

Zahaira González Romo

2011-05-01

Full Text Available La gestión estratégica de la marca a través de los medios de comunicación digital ha cobrado especial relevancia en los últimos años, y prácticamente todas las empresas que se aprecien de llevar una comunicación acorde a sus públicos han desarrollado herramientas y adaptado su comunicación de marca a los diferentes soportes, medios y entornos que han ido emergiendo, hasta el punto de que este proceso ha sufrido una metamorfosis que no todas las empresas consiguen asumir y entender. No sólo hablamos de un replanteamiento y adaptación a las nuevas tecnologías, sino una “nueva forma” de pensar las marcas y su repercusión e imagen en la mente de los consumidores. Tal es el caso de las aplicaciones para los smartphones, que se han desarrollado con una virulencia impresionante, aproximadamente 200.000 actualmente, y el número continúa creciendo. Este estudio pretende ser una primera aproximación a la aparición de las marcas en las aplicaciones para móviles, específicamente en las aplicaciones destinadas a iPhone.Gracias esta investigación sabemos que es indispensable tener en cuenta tres criterios básicos en el desarrollo de aplicaciones; el primero y más importante es que los anunciantes deben centrarse en el análisis de las necesidades de los usuarios, determinar sus objetivos, elaborar planes de integración y sobre todo preparar los medios de comunicación multicanal y de apoyo a la comercialización. Si la aplicación es correcta pero no funciona adecuadamente, deteriora la imagen de la marca de cara al cliente. En segundo lugar, la experiencia del usuario en las aplicaciones móviles debe ser complementaria y coherente con su experiencia a través de otros canales, es decir, debe mantenerse fiel a la marca y a la identidad de la empresa. Y el tercer criterio, es importante para la marca ir adaptándose a las nuevas tecnologías, pues una incorporación precaria y mal desarrollada puede ser más perjudicial que no el

SERS-active ZnO/Ag hybrid WGM microcavity for ultrasensitive dopamine detection

Science.gov (United States)

Lu, Junfeng; Xu, Chunxiang; Nan, Haiyan; Zhu, Qiuxiang; Qin, Feifei; Manohari, A. Gowri; Wei, Ming; Zhu, Zhu; Shi, Zengliang; Ni, Zhenhua

2016-08-01

Dopamine (DA) is a potential neuro modulator in the brain which influences a variety of motivated behaviors and plays a key role in life science. A hybrid ZnO/Ag microcavity based on Whispering Gallery Mode (WGM) effect has been developed for ultrasensitive detection of dopamine. Utilizing this effect of structural cavity mode, a Raman signal of R6G (5 × 10-3 M) detected by this designed surface-enhanced Raman spectroscopy (SERS)-active substrate was enhanced more than 10-fold compared with that of ZnO film/Ag substrate. Also, this hybrid microcavity substrate manifests high SERS sensitivity to rhodamine 6 G and detection limit as low as 10-12 M to DA. The Localized Surface Plasmons of Ag nanoparticles and WGM-enhanced light-matter interaction mainly contribute to the high SERS sensitivity and help to achieve a lower detection limit. This designed SERS-active substrate based on the WGM effect has the potential for detecting neurotransmitters in life science.

Stilbazolium Merocyanine Dye Determination in Different Solutions, Concentrations and Colloids Using SERS

DEFF Research Database (Denmark)

Pajchrowski, Grzegorz; Abdali, Salim; Nørbygaard, Thomas

2006-01-01

Surface Enhanced Raman Scattering (SERS) measurements were carried out on stilbazolium merocyanine dye in methanol and pyridine solvents. Both solutions were measured in series of concentrations, covering a range of 5·10-5 M to 5·10-8 M. In these measurements Ag and Au colloids were used and the ......Surface Enhanced Raman Scattering (SERS) measurements were carried out on stilbazolium merocyanine dye in methanol and pyridine solvents. Both solutions were measured in series of concentrations, covering a range of 5·10-5 M to 5·10-8 M. In these measurements Ag and Au colloids were used...... report here on the success of using SERS to obtain Raman spectra of merocyanine dye at very low concentration in an attempt of new approach, which can be used for further investigations of the dye. The SERS spectra will here be reported and the results from different solutions, colloids, concentrations...

[TLC-FT-SERS study on a pair of optic isomers in ephedra].

Science.gov (United States)

Wang, Yuan; Zhang, Jin-zhi; Ma, Xin-yong

2004-11-01

A new method for analyzing the ingredients of a pair of optic isomers in ephedra, nor-ephedrine and nor-pseudo-ephedrine, using hyphenated high-efficiency thin layer chromatography (TLC) and surface-enhanced Raman spectroscopy (SERS) techniques, is reported. The results show that the characteristic spectral bands of nor-ephedrine and nor-pseudo-ephedrine can be obtained from the TLC spot with 8 microg sample of about 2.0 mm in diameter. The difference between the SERS and solid spectra was found. Spectral bands at 1004 cm(-1) and 1605 cm(-1) were found greatly enhanced. Molecule was absorbed in surface silver sol by pi electrons in ring. Under similar experimental conditions the spectral information of Levo-nor-ephedrine ramifications TLC-SERS is rich with strong credibility, whereas dextral-nor-ephedrine ramifications show a relatively strong fluorescence backdrop with less spectral information and weak credibility. The effective combination of TLC and SERS can be used to analyse the chemical ingredients with high sensitivity.

Structure-dependent SERS activity of plasmonic nanorattles with built-in electromagnetic hotspots.

Science.gov (United States)

Liu, Keng-Ku; Tadepalli, Sirimuvva; Wang, Zheyu; Jiang, Qisheng; Singamaneni, Srikanth

2017-11-20

Hollow plasmonic nanostructures with built-in and accessible electromagnetic hotspots such as nanorattles, obtained through a galvanic replacement reaction, have received wide attention in chemical and biological sensing and targeted drug delivery. In this study, we investigate the surface enhanced Raman scattering (SERS) activity of plasmonic nanorattles obtained through different degrees of galvanic replacement of Au@Ag nanocubes. We found that the SERS efficacy of the nanorattles is governed by the plasmon extinction intensity, localized surface plasmon resonance (LSPR) wavelength of the nanostructures with respect to the excitation source and intensity of the electromagnetic field at the hotspot, with the latter playing a determining role. Finite-difference time-domain (FDTD) simulations showed excellent agreement with the experimental findings that an optimal degree of galvanic replacement is critical for maximum SERS enhancement. The rational design and synthesis of the plasmonic nanorattles based on these findings can make these nanostructures highly attractive for SERS-based chemical and biological sensing and bioimaging.

La responsabilidad social empresarial en los sectores de bebidas alcohólicas y gaseosas frente al problema de la publicidad sexista

OpenAIRE

Sotomayor Vizarreta, Jamali

2013-01-01

Una empresa puede mejorar su competitividad, no solo al supervisar la calidad de sus productos, sino también al comprometerse con su entorno: los grupos de interés o stakeholders. Esta perspectiva de competitividad, que implica nuevas estrategias, puede ser utilizada tanto para los directivos como para los trabajadores de la empresa. Al adoptar estas prácticas socialmente responsables, cualquier tipo de empresa construye u na necesaria estabilidad social dentro de la comu...

A reagent-assisted method in SERS detection of methyl salicylate

Science.gov (United States)

Li, Yali; Li, Qianwen; Wang, Yanan; Oh, Joohee; Jin, Sila; Park, Yeonju; Zhou, Tieli; Zhao, Bing; Ruan, Weidong; Jung, Young Mee

2018-04-01

With the explosive application of methyl salicylate (MS) molecules in food and cosmetics, the further detection of MS molecules becomes particularly important. Here we investigated the detection of MS molecules based on surface-enhanced Raman scattering (SERS) in a novel molecule/assistant/metal system constructed with MS, 4,4‧-(hexafluoroisopropylidene) bis (benzoic acid) and Ag nanoparticles (AgNPs). The minimum detection concentration is 10-4 M. To explore the function of assisted reagent, we also referred another system without assistant molecules. The result demonstrates that SERS signals were not acquired, which proves that the assistant molecules are critical for the capture of MS molecules. Two possible mechanisms of MS/assistant/AgNPs system were speculated through two patterns of hydrogen bonds. The linker molecules acted as the role of the bridge between metallic substrates and target molecules through the molecular recognition. This strategy is very beneficial to the expanding of MS detection techniques and other hydrogen bond based coupling detections with SERS.

In Vitro and In Vivo SERS Biosensing for Disease Diagnosis

Directory of Open Access Journals (Sweden)

T. Joshua Moore

2018-05-01

Full Text Available For many disease states, positive outcomes are directly linked to early diagnosis, where therapeutic intervention would be most effective. Recently, trends in disease diagnosis have focused on the development of label-free sensing techniques that are sensitive to low analyte concentrations found in the physiological environment. Surface-enhanced Raman spectroscopy (SERS is a powerful vibrational spectroscopy that allows for label-free, highly sensitive, and selective detection of analytes through the amplification of localized electric fields on the surface of a plasmonic material when excited with monochromatic light. This results in enhancement of the Raman scattering signal, which allows for the detection of low concentration analytes, giving rise to the use of SERS as a diagnostic tool for disease. Here, we present a review of recent developments in the field of in vivo and in vitro SERS biosensing for a range of disease states including neurological disease, diabetes, cardiovascular disease, cancer, and viral disease.

Development of chitosan-coated gold nanoflowers as SERS-active probes

Science.gov (United States)

Xu, Dan; Gu, Jiangjiang; Wang, Weina; Yu, Xuehai; Xi, Kai; Jia, Xudong

2010-09-01

Surface-enhanced Raman scattering (SERS) has been intensely researched for many years as a potential technique for highly sensitive detection. This work, through the reduction of HAuCl4 with pyrrole in aqueous solutions, investigated a facile one-pot synthesis of flower-like Au nanoparticles with rough surfaces. The formation process of the Au nanoflowers (AuNFs) was carefully studied, and a spontaneous assembly mechanism was proposed based on the time-course experimental results. The key synthesis strategy was to use pyrrole as a weak particle stabilizing and reducing agent to confine crystal growth in the limited ligand protection region. The nanometer-scale surface roughness of AuNFs provided several hot spots on a single particle, which significantly increased SERS enhancement. Good biocompatible stable Raman-active probes were synthesized by coating AuNFs with chitosan. The conservation of the SERS effects in living cells suggested that the chitosan-capped AuNFs could be suitable for highly sensitive detection and have potential for targeting of tumors in vivo.

Mujeres y poder en el islam. II: La Reina Libre sulayh?? al-Sayyida (Arw??) bint Ahmad (440-532/1048-9-1138)

OpenAIRE

Chaves Hern??ndez, Eva

2008-01-01

Este trabajo es una biograf??a y estudio de la Reina Libre al-Sayyida bint Ahmad de la dinast??a de los sulayh??es de Yemen. Al-Sayyida al- Hurra fue un gran personaje pol??tico en su ??poca y su figura tiene un protagonismo especial en la historia de Yemen y del ismaelismo y sobre todo en el ismaelismo tayyib??, al ser ella quien diera origen a esta nueva orden religiosa. No s??lo destaca como gran referente de mujer gobernante ??rabe y musulmana de la Edad Media, sino tambi??n como ejemplo ...

Development of surface enhanced Raman scattering (SERS) spectroscopy monitoring of fuel markers to prevent fraud

Science.gov (United States)

Wilkinson, Timothy; Clarkson, John; White, Peter C.; Meakin, Nicholas; McDonald, Ken

2013-05-01

Governments often tax fuel products to generate revenues to support and stimulate their economies. They also subsidize the cost of essential fuel products. Fuel taxation and subsidization practices are both subject to fraud. Oil marketing companies also suffer from fuel fraud with loss of legitimate sales and additional quality and liability issues. The use of an advanced marking system to identify and control fraud has been shown to be effective in controlling illegal activity. DeCipher has developed surface enhanced Raman scattering (SERS) spectroscopy as its lead technology for measuring markers in fuel to identify and control malpractice. SERS has many advantages that make it highly suitable for this purpose. The SERS instruments are portable and can be used to monitor fuel at any point in the supply chain. SERS shows high specificity for the marker, with no false positives. Multiple markers can also be detected in a single SERS analysis allowing, for example, specific regional monitoring of fuel. The SERS analysis from fuel is also quick, clear and decisive, with a measurement time of less than 5 minutes. We will present results highlighting our development of the use of a highly stable silver colloid as a SERS substrate to measure the markers at ppb levels. Preliminary results from the use of a solid state SERS substrate to measure fuel markers will also be presented.

Ser y estar. Fenomenología y lingüística: Un acercamiento a la comprensión de la cultura latinoamericana

Directory of Open Access Journals (Sweden)

Witton Becerra Mayorga

2008-01-01

Full Text Available La fenomenología en la tradición del pensamiento europeo es la corriente filosófica de inflexión que permite pensar otros modos de ser de la cultura de otros pueblos, de otros ethos , como lo es el del hombre latinoamericano. En el siguiente trabajo me permito postular para el caso de América Latina una nueva forma de concebir la cultura desde las bases de la fenomenología como punto de inexión del pensamiento occi - dental que posibilita crear nuevos espacios de conformación de nuestro modo de ser. Lo primero que hago es definir las profundas separaciones entre la lingüística tradicional y positiva con una lingüística de la significación cercana a los postulados de una feno - menología del lenguaje. Luego de esto, bosquejo una legitimación del pensamiento situado para referirme al caso de la inexión de la fenomenología para pensar la cultura latinoamericana haciendo énfasis en la literatura. Y, nalmente, trato la cuestión del ser y el estar como característica gramatical y ontológica de Latinoamérica como punto eje para pensar nuestra cultura en nuestro tiempo, en una época de crisis.

Fabrication of SERS Substrate by Multilayered Nanosphere Deposition Technique

International Nuclear Information System (INIS)

Fu, Chit Yaw; Dinish, U. S.; Praveen, Thoniyot; Koh, Zhen Yu; Kho, Khiang Wei; Malini, Olivo

2010-01-01

Metal film over nanosphere (MFON) has been employed as a reproducible and predictable SERS-active device in biosensing applications. In addition to its economic fabrication process, such substrate can be further processed to a prism-structure with increased SERS enhancement and wider Plasmon tunability. In this work, we investigate an alternative coating method to deposit a larger area of well-ordered PS beads with different sizes (oe = 100nm and 400 nm) onto a glass. The result suggests that the proposed well-coating technique can be suitably used to form closely-packed PS beads with diameter less than 100 nm for developing MFON substrates.

Label-free SERS in biological and biomedical applications: Recent progress, current challenges and opportunities

Science.gov (United States)

Zheng, Xiao-Shan; Jahn, Izabella Jolan; Weber, Karina; Cialla-May, Dana; Popp, Jürgen

2018-05-01

To achieve an insightful look within biomolecular processes on the cellular level, the development of diseases as well as the reliable detection of metabolites and pathogens, a modern analytical tool is needed that is highly sensitive, molecular-specific and exhibits fast detection. Surface-enhanced Raman spectroscopy (SERS) is known to meet these requirements and, within this review article, the recent progress of label-free SERS in biological and biomedical applications is summarized and discussed. This includes the detection of biomolecules such as metabolites, nucleic acids and proteins. Further, the characterization and identification of microorganisms has been achieved by label-free SERS-based approaches. Eukaryotic cells can be characterized by SERS in order to gain information about the outer cell wall or to detect intracellular molecules and metabolites. The potential of SERS for medically relevant detection schemes is emphasized by the label-free detection of tissue, the investigation of body fluids as well as applications for therapeutic and illicit drug monitoring. The review article is concluded with an evaluation of the recent progress and current challenges in order to highlight the direction of label-free SERS in the future.

Synthesis of Dendritic Silver Nanoparticles and Their Applications as SERS Substrates

Directory of Open Access Journals (Sweden)

Jinshan Yu

2013-01-01

Full Text Available The silver nanoparticles are synthesized by electrodeposition in ultradilute Ag+ concentration electrolyte under high overpotential. The as prepared Ag nanoparticles, with the sizes ranging from 20 to 30 nm, are arrayed orderly and formed dendritic morphology. The formation of this special dendritic nanoparticle structure can be contributed to the relatively high growth rate and the preferential growth directions along 111 due to the high overpotential, as well as the relative small number of Ag+ ions arriving at the Ag crystal surface per unit time due to the ultradilute Ag+ concentration. Surface enhanced Raman scattering (SERS experiments reveal that the as-prepared dendritic Ag nanoparticles possess high SERS properties and can be used as a candidate substrate for practical SERS applications to detect the Rhodamine 6G molecules.

Development of protective coatings to improve the Ti6Al4V alloy behavior in orthopedic applications

OpenAIRE

Sáenz de Viteri Gimeno, Virginia

2016-01-01

332 p. Hoy en día, debido al aumento de la esperanza de vida, al elevado ritmo de vida y al aumento del número de personas que practican deporte, es necesario que el ser humano esté activo y dinámico durante más tiempo. Esto implica una serie de problemas a nivel osteo-articular que pueden limitar la actividad física y la calidad de vida de las personas. En algunos casos, estas complicaciones pueden llegar a necesitar una total o parcial reconstrucción o reemplazo de un tejido, hueso o art...

EL ACCESO AL CRÉDITO PARA MICROEMPRESAS EN ALAJUELA, CARTAGO Y HEREDIA

Directory of Open Access Journals (Sweden)

Esteban Méndez Chacón

2013-03-01

Full Text Available El objetivo principal de este trabajo es analizar el grado de acceso al crédito para microempresarios en Alajuela, Cartago y Heredia. Se toma como muestra un grupo de 401 negocios, que posean de 1 a 5 trabajadores y que no se dediquen a actividades agrícolas. El artículo muestra que el grado de acceso al crédito de los microempresarios suele ser bajo en lo que respecta a créditos formales (instituciones financieras reguladas por la SUGEF e informales (prestamistas, parientes o amigos, pero alto en lo relativo a créditos semi-informales (proveedores y clientes.

ENSAIO DE CONTROLE QUÍMICO ÀS PRINCIPAIS LAGARTAS E PERCEVEJOS DA SOJA EM GOIÁS ESSAY ON CHEMICAL CONTROL OF THE MAIN LARVAS AND CHINCH BUGS OF SOYBEAN IN GOIÁS

Directory of Open Access Journals (Sweden)

Valquíria da R. S. Veloso

2007-09-01

Full Text Available

Foi realizado em 1979/80, um ensaio de campo visando a avaliar a eficiência e adequar as doses dos inseticidas Bacillus thuringienses, Carbaryl , Clorpirifos , Deltametrina, Deltametrina + S 339, Endosulfan, Metil Paration, monocrotofos e triclorfon no combate a Anticarsia gemmatalis e Pseudoplusia includens. No mesmo ano, usaram-se os inseticidas Carbaryl Cyanamid AC 222 705, Deltametrina, Deltametrina + S 339, Dimetoato, Endosulfan, FMC 35001, Metil Paration, Monocrotofos, Permetrina, Phosalone + Paration Etil e Triciorfon, para o controle de Piezodorus guildinii, Nezara viridula e Euschistus heros. Todos os tratamentos foram aplicados em blocos ao acaso com quatro repetições. As avaliações de controle para lagartas foram efetuadas em 1, 2 e 7 dias após aplicação e para percevejos foram efetuadas em 2 e 7 dias após aplicação. Pelos resultados obtidos, verificou-se o seguinte: aA. gemmatalis foi sensível à maioria dos produtos; bapenas Clorpirifos Etil, Hetil Paration e Triclorfon não apresentaram eficiência acima de 80% para P. includens sete dias após a aplicação; c os inseticidas Monocrotofos, Metil Paration, Carbaryl e FMC 35001 mostraram eficiência acima de 80% para as espécies N. viridula e P. guildinii; Endosulfon e Dimetoato foram eficientes para controlar P. guildinii e E. heros.

During the 1979/80 planting period, a field test was performed to estimate the insecticides efficiency and adjust their doses in order to control Anticarsia qemmatalis and Pseudoplusia includens and also Piezodorus guildinii, Nezara viridula and Euschistus heros. For A. gemmatalis and P. includens control, the following insecticides were used: Baccilus thuringienses, Carbaryl, Clorpirifos, Decamethrin + S 339, Dimetoate, Endosulfan, Methyl Parathion, Monocrotophos and Triclorfon. For stink bugs, the

In cellulo phosphorylation of XRCC4 Ser320 by DNA-PK induced by DNA damage

International Nuclear Information System (INIS)

Sharma, Mukesh Kumar; Imamichi, Shoji; Fukuchi, Mikoto; Samarth, Ravindra Mahadeo; Tomita, Masanori; Matsumoto, Yoshihisa

2016-01-01

XRCC4 is a protein associated with DNA Ligase IV, which is thought to join two DNA ends at the final step of DNA double-strand break repair through non-homologous end joining. In response to treatment with ionizing radiation or DNA damaging agents, XRCC4 undergoes DNA-PK-dependent phosphorylation. Furthermore, Ser260 and Ser320 (or Ser318 in alternatively spliced form) of XRCC4 were identified as the major phosphorylation sites by purified DNA-PK in vitro through mass spectrometry. However, it has not been clear whether these sites are phosphorylated in vivo in response to DNA damage. In the present study, we generated an antibody that reacts with XRCC4 phosphorylated at Ser320 and examined in cellulo phosphorylation status of XRCC4 Ser320. The phosphorylation of XRCC4 Ser320 was induced by γ-ray irradiation and treatment with Zeocin. The phosphorylation of XRCC4 Ser320 was detected even after 1 Gy irradiation and increased in a manner dependent on radiation dose. The phosphorylation was observed immediately after irradiation and remained mostly unchanged for up to 4 h. The phosphorylation was inhibited by DNA-PK inhibitor NU7441 and was undetectable in DNA-PKcs-deficient cells, indicating that the phosphorylation was mainly mediated by DNA-PK. These results suggested potential usefulness of the phosphorylation status of XRCC4 Ser320 as an indicator of DNA-PK functionality in living cells

Análisis probabilista con caminata al azar del número de personas viviendo con VIH mundialmente

Directory of Open Access Journals (Sweden)

Javier Oswaldo Rodríguez-Velásquez

2018-01-01

Full Text Available Introducción: El estudio de la dinámica anual de la epidemia de VIH a partir de la caminata al azar ha mostrado ser de utilidad para llevar este fenómeno altamente variable a un comportamiento predecible Objetivo: Predecir el comportamiento de la dinámica del número de personas viviendo con VIH mediante la caminata al azar probabilista. Metodología: Se analizaron los valores anuales de personas que a nivel global viven con VIH desde el año 1990 hasta el 2009, a partir de los espacios de probabilidad generados con la caminata al azar probabilista, para posteriormente desarrollar la predicción del valor anual de personas viviendo con VIH para los años 2010, 2011 y 2012. Resultados: Se predijeron los valores anuales de personas viviendo con VIH con un porcentaje de acierto de 98,95% para el año 2010, de 98,82% para el año 2011 y de 98,99% para la predicción realizada para el año 2012. Conclusiones: Se establecieron órdenes matemáticos a partir de la caminata al azar probabilista, estableciendo predicciones prácticamente deterministas del número de personas viviendo con VIH, lo que podría ser útil para las decisiones en Salud Pública y para la evaluación de intervenciones.

Why Ser and not Thr brokers catalysis in the trypsin fold.

Science.gov (United States)

Pelc, Leslie A; Chen, Zhiwei; Gohara, David W; Vogt, Austin D; Pozzi, Nicola; Di Cera, Enrico

2015-02-24

Although Thr is equally represented as Ser in the human genome and as a nucleophile is as good as Ser, it is never found in the active site of the large family of trypsin-like proteases that utilize the Asp/His/Ser triad. The molecular basis of the preference of Ser over Thr in the trypsin fold was investigated with X-ray structures of the thrombin mutant S195T free and bound to an irreversible active site inhibitor. In the free form, the methyl group of T195 is oriented toward the incoming substrate in a conformation seemingly incompatible with productive binding. In the bound form, the side chain of T195 is reoriented for efficient substrate acylation without causing steric clash within the active site. Rapid kinetics prove that this change is due to selection of an active conformation from a preexisting ensemble of reactive and unreactive rotamers whose relative distribution determines the level of activity of the protease. Consistent with these observations, the S195T substitution is associated with a weak yet finite activity that allows identification of an unanticipated important role for S195 as the end point of allosteric transduction in the trypsin fold. The S195T mutation abrogates the Na(+)-dependent enhancement of catalytic activity in thrombin, activated protein C, and factor Xa and significantly weakens the physiologically important allosteric effects of thrombomodulin on thrombin and of cofactor Va on factor Xa. The evolutionary selection of Ser over Thr in trypsin-like proteases was therefore driven by the need for high catalytic activity and efficient allosteric regulation.

Láser helio-neón combinado con clorhexidina al 0,2 %.: Efectos clínicos y microbiológicos en el tratamiento de la gingivitis crónica Helium-neon laser combined with 0.2% chlorhexidine: Clinical and microbiological effects in the treatment of chronic gingivitis.

Directory of Open Access Journals (Sweden)

Tatiana Peña Ruiz

2007-09-01

Full Text Available La gingivitis crónica constituye una de las formas más frecuentes de enfermedad periodontal, caracterizada por la inflamación crónica de la encías, tumefacción, enrojecimiento y sangramiento. Su principal factor de riesgo lo constituye la microbiota del surco gingival, que resulta necesario, pero no suficiente para desencadenarla. Se realizó un ensayo clínico-terapéutico fase II, controlado, aleatorizado y a simple ciegas, para evaluar los efectos clínicos y microbiológicos del tratamiento combinado de la radiación láser helio-neón (He-Ne con la clorhexidina al 0,2 %. Todos los pacientes recibieron tratamiento inicial; al mes de finalizado este, se distribuyeron aleatoriamente en 2 grupos: un grupo estudio que recibió la combinación láser-neón y clorhexidina al 0,2 % y otro grupo control que solo recibió clorhexidina al 0,2 %. Se realizó una evaluación a los 15, 30 y 45 días, con criterios de eficacia clínicos y microbiológicos. Los resultados clínicos fueron satisfactorios en el grupo estudio con predominio de los morfotipos I, caracterizados por cocos gramnegativos y positivos, compatibles con un periodonto sano. Los eventos adversos detectados con esta terapéutica fueron mínimos, todos relacionados con la somnolencia.Chronic gingivitis is one of the most common periodontal diseases that is characterized by chronic inflammation, tumefaction, redness and bleeding. The main risk factor is gingival sulcus microbiota that is essential but not enough to unleash it. A phase II controlled randomized blind clinical/therapeutical assay was conducted to evaluate the clinical and microbiological effects of the combined treatment based on helium-neon laser (He-Ne with 0.2% chlorhexidine. All the patients were initially treated; after a month, they were randomly distributed into two groups, that is, the study group received a helium-neon laser plus 0.2% chlorhexidine combination and the control group was treated with 0

Patchy silica-coated silver nanowires as SERS substrates

International Nuclear Information System (INIS)

Hunyadi Murph, Simona E.; Murphy, Catherine J.

2013-01-01

We report a class of core–shell nanomaterials that can be used as efficient surface-enhancement Raman scattering (SERS) substrates. The core consists of silver nanowires, prepared through a chemical reduction process, that are used to capture 4-mercaptobenzoic acid (4-MBA), a model analyte. The shell was prepared through a modified Stöber method and consists of patchy or full silica coats. The formation of silica coats was monitored via transmission electron microscopy, UV–visible spectroscopy, and phase-analysis light-scattering for measuring effective surface charge. Surprisingly, the patchy silica-coated silver nanowires are better SERS substrate than silver nanowires; nanomolar concentration of 4-MBA can be detected. In addition, “nano-matryoshka” configurations were used to quantitate/explore the effect of the electromagnetic field at the tips of the nanowire (“hot spots”) in the Raman scattering experiment.

Patchy silica-coated silver nanowires as SERS substrates

Energy Technology Data Exchange (ETDEWEB)

Hunyadi Murph, Simona E.; Murphy, Catherine J.

2013-05-08

We report a class of core-shell nanomaterials that can be used as efficient surface-enhancement Raman scattering (SERS) substrates. The core consists of silver nanowires, prepared through a chemical reduction process, that are used to capture 4- mercaptobenzoic acid (4-MBA), a model analyte. The shell was prepared through a modified Stöber method and consists of patchy or full silica coats. The formation of silica coats was monitored via transmission electron microscopy, UV-visible spectroscopy and phase-analysis light scattering for measuring effective surface charge. Surprisingly, the patchy silica coated silver nanowires are better SERS substrate than silver nanowires; nanomolar concentration of 4-MBA can be detected. In addition, “nano-matryoshka” configurations were used to quantitate/explore the effect of the electromagnetic field at the tips of the nanowire (“hot spots”) in the Raman scattering experiment.

Ultra-thin layer chromatography with integrated silver colloid-based SERS detection.

Science.gov (United States)

Wallace, Ryan A; Lavrik, Nickolay V; Sepaniak, Michael J

2017-01-01

Simplified lab-on-a-chip techniques are desirable for quick and efficient detection of analytes of interest in the field. The following work involves the use of deterministic pillar arrays on the micro-scale as a platform to separate compounds, and the use of Ag colloid within the arrays as a source of increased signal via surface enhanced Raman spectroscopy (SERS). One problem traditionally seen with SERS surfaces containing Ag colloid is oxidation; however, our platforms are superhydrophobic, reducing the amount of oxidation taking place on the surface of the Ag colloid. This work includes the successful separation and SERS detection of a fluorescent dye compounds (resorufin and sulforhodamine 640), fluorescent anti-tumor drugs (Adriamycin and Daunomycin), and purine and pyrimidine bases (adenine, cytosine, guanine, hypoxanthine, and thymine). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis, characterization and SERS activity of biosynthesized silver nanoparticles

Science.gov (United States)

Bindhu, M. R.; Sathe, V.; Umadevi, M.

2013-11-01

Silver nanoparticles were rapidly synthesized using Moringa oleifera flower extract as the reducing agent shows surface plasmon resonance peak at 439 nm. The size and shape of the nanoparticles controlled by varying the concentration of M. oleifera flower extract in the reaction medium. The synthesized silver nanoparticles were well-dispersed spherical nanoparticles with the average size of 14 nm. The retinoic acid present in M. oleifera flower extract used as reducing agent and proteins was responsible for capping of the bioreduced silver nanoparticles. The obtained nanoparticle shows size-dependent SERS activity. The SERS spectrum indicates that the pyridine adsorbed on the silver surface in a stand-on orientation via its nitrogen lone pair electrons.

Design of SERS nanoprobes for Raman imaging: materials, critical factors and architectures.

Science.gov (United States)

Li, Mingwang; Qiu, Yuanyuan; Fan, Chenchen; Cui, Kai; Zhang, Yongming; Xiao, Zeyu

2018-05-01

Raman imaging yields high specificity and sensitivity when compared to other imaging modalities, mainly due to its fingerprint signature. However, intrinsic Raman signals are weak, thus limiting medical applications of Raman imaging. By adsorbing Raman molecules onto specific nanostructures such as noble metals, Raman signals can be significantly enhanced, termed surface-enhanced Raman scattering (SERS). Recent years have witnessed great interest in the development of SERS nanoprobes for Raman imaging. Rationally designed SERS nanoprobes have greatly enhanced Raman signals by several orders of magnitude, thus showing great potential for biomedical applications. In this review we elaborate on recent progress in design strategies with emphasis on material properties, modifying factors, and structural parameters.

Interpenetrating polyaniline-gold electrodes for SERS and electrochemical measurements

Science.gov (United States)

West, R. M.; Semancik, S.

2016-11-01

Facile fabrication of nanostructured electrode arrays is critical for development of bimodal SERS and electrochemical biosensors. In this paper, the variation of applied potential at a polyaniline-coated Pt electrode is used to selectivity deposit Au on the polyaniline amine sites or on the underlying Pt electrode. By alternating the applied potential, the Au is grown simultaneously from the top and the bottom of the polyaniline film, leading to an interpenetrated, nanostructured polymer-metal composite extending from the Pt electrode to the electrolyte solution. The resulting films have unique pH-dependent electrochemical properties, e.g. they retain electrochemical activity in both acidic and neutral solutions, and they also include SERS-active nanostructures. By varying the concentration of chloroaurate used during deposition, Au nanoparticles, nanodendrites, or nanosheets can be selectively grown. For the films deposited under optimal conditions, using 5 mmol/L chloroaurate, the SERS enhancement factor for Rhodamine 6G was found to be as high as 1.1 × 106 with spot-to-spot and electrode-to-electrode relative standard deviations as low as 8% and 12%, respectively. The advantages of the reported PANI-Au composite electrodes lie in their facile fabrication, enabling the targeted deposition of tunable nanostructures on sensing arrays, and their ability to produce orthogonal optical and electrochemical analytical results.

Surface enhanced Raman spectroscopy (SERS for in vitro diagnostic testing at the point of care

Directory of Open Access Journals (Sweden)

Marks Haley

2017-06-01

Full Text Available Point-of-care (POC device development is a growing field that aims to develop low-cost, rapid, sensitive in-vitro diagnostic testing platforms that are portable, self-contained, and can be used anywhere – from modern clinics to remote and low resource areas. In this review, surface enhanced Raman spectroscopy (SERS is discussed as a solution to facilitating the translation of bioanalytical sensing to the POC. The potential for SERS to meet the widely accepted “ASSURED” (Affordable, Sensitive, Specific, User-friendly, Rapid, Equipment-free, and Deliverable criterion provided by the World Health Organization is discussed based on recent advances in SERS in vitro assay development. As SERS provides attractive characteristics for multiplexed sensing at low concentration limits with a high degree of specificity, it holds great promise for enhancing current efforts in rapid diagnostic testing. In outlining the progression of SERS techniques over the past years combined with recent developments in smart nanomaterials, high-throughput microfluidics, and low-cost paper diagnostics, an extensive number of new possibilities show potential for translating SERS biosensors to the POC.

Surface enhanced Raman spectroscopy (SERS) for in vitro diagnostic testing at the point of care

Science.gov (United States)

Marks, Haley; Schechinger, Monika; Garza, Javier; Locke, Andrea; Coté, Gerard

2017-06-01

Point-of-care (POC) device development is a growing field that aims to develop low-cost, rapid, sensitive in-vitro diagnostic testing platforms that are portable, self-contained, and can be used anywhere - from modern clinics to remote and low resource areas. In this review, surface enhanced Raman spectroscopy (SERS) is discussed as a solution to facilitating the translation of bioanalytical sensing to the POC. The potential for SERS to meet the widely accepted "ASSURED" (Affordable, Sensitive, Specific, User-friendly, Rapid, Equipment-free, and Deliverable) criterion provided by the World Health Organization is discussed based on recent advances in SERS in vitro assay development. As SERS provides attractive characteristics for multiplexed sensing at low concentration limits with a high degree of specificity, it holds great promise for enhancing current efforts in rapid diagnostic testing. In outlining the progression of SERS techniques over the past years combined with recent developments in smart nanomaterials, high-throughput microfluidics, and low-cost paper diagnostics, an extensive number of new possibilities show potential for translating SERS biosensors to the POC.

El láser de helio-neon en la regeneración del nervio ciático seccionado y suturado

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Pedro Rodríguez Sotelo

Full Text Available Para valorar el efecto del láser de helio-neón (He-Ne sobre la regeneración del nervio ciático, seccionado y suturado, se utilizaron un total de 72 ratas Wistar, que se dividieron en 3 grupos, los cuales fueron irradiados con He-Ne, luz de xenón y luz solar respectivamente. Al grupo testigo sólo se les realizó la sección y sutura del nervio ciático. Lasratas a las que se les irradió el nervio con luz de xenón y luz solar evolucionaron igual que el grupo testigo, es decir, se presentaron en su totalidad, lesiones tróficas de mayor o menor grado, así como lesiones motrices. En el grupo en el que se utilizó He-Ne, sólo se observó en un animal la pérdida de la una de un dedo y no se apreciaron trastornos motrices. La irradiación con láser de He-Ne tiene una importante influencia en la restauración de las lesiones nerviosas en la rata

Rapid detection of acetamiprid in foods using surface-enhanced Raman spectroscopy (SERS).

Science.gov (United States)

Wijaya, Wisiani; Pang, Shintaro; Labuza, Theodore P; He, Lili

2014-04-01

Acetamiprid is a neonicotinoid pesticide that is commonly used in modern farming. Acetamiprid residue in food commodities can be a potential harm to human and has been implicated in the honey bee hive die off crisis. In this study, we developed rapid, simple, and sensitive methods to detect acetamiprid in apple juice and on apple surfaces using surface-enhanced Raman spectroscopy (SERS). No pretreatment of apple juice sample was performed. A simple surface swab method was used to recover acetamiprid from the apple surface. Samples were incubated with silver dendrites for several minutes and SERS spectra were taken directly from the silver surface. Detection of a set of 5 apple juice samples can be done within 10 min. The swab-SERS method took 15 min for a set of 5 samples. Resulting spectral data were analyzed using principal component analysis. The highest acetamiprid peak at 634 cm(-1) was used to detect and quantify the amount of acetamiprid spiked in 1:1 water-methanol solvent, apple juice, and on apple surface. The SERS method was able to successfully detect acetamiprid at 0.5 μg/mL (0.5 ppm) in solvent, 3 μg/mL (3 ppm) in apple juice, and 0.125 μg/cm(2) on apple surfaces. The SERS methods provide simple, rapid, and sensitive ways to detect acetamiprid in beverages and on the surfaces of thick skinned fruits and vegetables. © 2014 Institute of Food Technologists®

Discurso de Benedicto XVI al cuerpo diplomático acreditado ante la Santa Sede

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Antonio Alonso

2008-01-01

Full Text Available El autor glosa el Discurso que al comienzo de cada año dirige el Santo Padre a los miembros del cuerpo diplomático acreditado ante la Santa Sede. El Papa divide su intervención en dos partes: una, dedicada a ofrecer una panorámica de las situaciones internacionales más preocupantes relacionadas con la paz y la seguridad; y la otra, dedicada a hacer un llamamiento a buscar en la Ley natural la base de la convivencia humana, sea nacional o internacional, pues es la más adecuada al ser humano.

Ser do tempo em Bergson

OpenAIRE

Coelho, Jonas Gonçalves

2004-01-01

O artigo apresenta a concepção bergsoniana de duração. Pretende-se mostrar que, segundo Bergson, o tempo dos filósofos e cientistas é um tempo fictício, um esquema espacial que oculta a natureza do tempo real, o qual não pode ser separado dos acontecimentos físicos e psicológicos. Para Bergson, o tempo real é sucessão, continuidade, mudança, memória e criação. We considered Bergson's duration concept. We intended to show that, according to Bergson, the time of philosophers and scientists i...

Sintomatologia da depress?o e representa??es sociais de ser idoso e depress?o

OpenAIRE

Oliveira, Marcos Francisco de

2011-01-01

Introdu??o: O envelhecimento, apesar de ser uma grande vit?ria, est? causando uma ampla preocupa??o para os governantes, devido ao aumento populacional e ao risco de adoecimento, capaz de afetar a qualidade de vida das pessoas idosas. Objetivos: Avaliar a sintomatologia da depress?o referida por idosos; conhecer as representa??es sociais sobre ser idoso e depress?o; e identificar aspectos psicossociais associados a ser idoso e depress?o. Metodologia: Estudo explorat?rio, realiz...

Application of surface-enhanced Raman spectroscopy (SERS) for cleaning verification in pharmaceutical manufacture.

Science.gov (United States)

Corrigan, Damion K; Cauchi, Michael; Piletsky, Sergey; Mccrossen, Sean

2009-01-01

Cleaning verification is the process by which pharmaceutical manufacturing equipment is determined as sufficiently clean to allow manufacture to continue. Surface-enhanced Raman spectroscopy (SERS) is a very sensitive spectroscopic technique capable of detection at levels appropriate for cleaning verification. In this paper, commercially available Klarite SERS substrates were employed in order to obtain the necessary enhancement of signal for the identification of chemical species at concentrations of 1 to 10 ng/cm2, which are relevant to cleaning verification. The SERS approach was combined with principal component analysis in the identification of drug compounds recovered from a contaminated steel surface.

[TLC-SERS study on evodiamine in evodia rutaecarpa].

Science.gov (United States)

Zhang, Jin-zhi; Wang, Yuan; Chen, Hui; Shao, Hui-bo

2007-05-01

A new method for analyzing the ingredients of evodiamine (EV), rutaecarpine (RU), hydroxyevodiamine (HYD), evodiamide (ED), dihydrorutaecarpine (DRU) and 14-formyldihydrorutaecarpine (FDRU) in evodia rutaecarpa using high performance thin layer chromatography (TLC) and surface enhanced Raman spectroscopy (SERS) technique is reported. The character of this method is that standard samples are not needed. The results show that the characteristic spectral bands of EV, RU, HYD, and ED can be obtained from the TLC spot with microgramme of sample. The spectral band at 1562 cm(-1) was obtained with great enhancement. Molecule absorbed in surface silver sol by nr electrons in ring. The spectral bands of EV, RU, HYD and ED are obviously different due to their differences in structure. The TLC and SERS techniques standard samples are a convenient and speedy method to analyze chemical ingredients with high sensitivity for the study of the Chinese traditional medicine.

SERS analysis of Ag nanostructures produced by ion-beam deposition

Science.gov (United States)

Atanasov, P. A.; Nedyalkov, N. N.; Nikov, Ru G.; Grüner, Ch; Rauschenbach, B.; Fukata, N.

2018-03-01

This study deals with the development of a novel technique for formation of advanced Ag nanostructures (NSs) to be applied to high-resolution analyses based on surface enhanced Raman scattering (SERS). It has direct bearing on human health and food quality, e.g., monitoring small amount or traces of pollutants or undesirable additives. Three types of nanostructured Ag samples were produced using ion-beam deposition at glancing angle (GLAD) on quartz. All fabricated structures were covered with BI-58 pesticide (dimethoate) or Rhodamine 6G (R6G) for testing their potential for use as substrates for (SERS).

Abdome agudo em pós-operatório tardio de apendicite aguda: pode não ser bridas

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Bruno Castro Fernandes

2014-10-01

Full Text Available As ressecções intestinais em países desenvolvidos ocorrem devido às malformações congênitas. Em países em desenvolvimento essas resseções ocorrem por causas potencialmente evitáveis, como invaginação intestinal irredutível, trauma abdominal fechado, volvo de jejuno-íleo, enterocolite necrosante, hérnia inguinal estrangulada e obstrução por bridas pós-operatórias. O volvo intestinal na infância é raro e geralmente de causas iatrogênicas causado, por exemplo, pela presença de grampos soltos a cavidade intestinal após apendicectomia laparoscópica. O volvo de jejuno-íleo pode ser secundário à isquemia nos casos de gastrosquise tratadas com silo ou mesmo pela colocação de banda gástrica pós-laparoscopia, ou ainda pela presença de lipoma mesentérico. Não foi identificado trabalho na literatura recente sobre volvo jejuno-íleo e isquemia e necrose de segmento de alça intestinal. O autores relatam um caso de abdome agudo obstrutivo em criança de 6 anos, em pós-operatório tardio (4 anos de apendicectomia aberta e cuja ressecção de segmento de Alça intestinal foi necessária nas duas oportunidades mas por motivos diferentes. Situações adversas em abdome agudo pós-operatório podem não ser por aderências intestinais, mas por situações mais graves e o cirurgião deve estar preparado para corrigir sua tática operatória.

Surface Enhanced Raman Spectroscopy (SERS) methods for endpoint and real-time quantification of miRNA assays

Science.gov (United States)

Restaino, Stephen M.; White, Ian M.

2017-03-01

Surface Enhanced Raman spectroscopy (SERS) provides significant improvements over conventional methods for single and multianalyte quantification. Specifically, the spectroscopic fingerprint provided by Raman scattering allows for a direct multiplexing potential far beyond that of fluorescence and colorimetry. Additionally, SERS generates a comparatively low financial and spatial footprint compared with common fluorescence based systems. Despite the advantages of SERS, it has remained largely an academic pursuit. In the field of biosensing, techniques to apply SERS to molecular diagnostics are constantly under development but, most often, assay protocols are redesigned around the use of SERS as a quantification method and ultimately complicate existing protocols. Our group has sought to rethink common SERS methodologies in order to produce translational technologies capable of allowing SERS to compete in the evolving, yet often inflexible biosensing field. This work will discuss the development of two techniques for quantification of microRNA, a promising biomarker for homeostatic and disease conditions ranging from cancer to HIV. First, an inkjet-printed paper SERS sensor has been developed to allow on-demand production of a customizable and multiplexable single-step lateral flow assay for miRNA quantification. Second, as miRNA concentrations commonly exist in relatively low concentrations, amplification methods (e.g. PCR) are therefore required to facilitate quantification. This work presents a novel miRNA assay alongside a novel technique for quantification of nuclease driven nucleic acid amplification strategies that will allow SERS to be used directly with common amplification strategies for quantification of miRNA and other nucleic acid biomarkers.

Servicios auxiliares asociados al transporte marítimo

OpenAIRE

Godes Gallardo, Daniel

2014-01-01

En este proyecto, mi intención es profundizar en los servicios auxiliares asociados al transporte marítimo, como su título indica. En él haré referencia a todos los servicios que el transporte marítimo en sí, y más en concreto los buques, utilizan cada vez que entran a puerto.En algunos casos, estos servicios no se prestan en las instalaciones del puerto, como pueden ser los servicios exclusivospara la explotación comercial del buque. Hay que tener en cuenta que, se podría hacer un trabajo...

The SIP express router: An open source SIP platform: Presentation held at EVOLUTE - seamlEss multimedia serVices Over alL IP-based infrastrUcTurEs Workshop, 10. November 2003, Guildford, UK

OpenAIRE

Rebahi, Y.; Sisalem, D.; Kuthan, J.; Pelinescu-Oncicul, A.; Iancu, B.; Janak, J.; Mierla, D.C.

2003-01-01

The session initiation protocol (SIP) is constantly gaining in popularity and acceptance as the signaling protocol for next generation multimedia communication. This paper describes a scalable and reliable open source SIP platform called the SIP Express Router (SER). SER does not only support basic SIP features but also advanced features such as messaging and presence, translation between SIP and SMS or Jabber as well as full featured application programming interfaces. In this paper we will ...

Monitoring prion protein expression in complex biological samples by SERS for diagnostic applications

Energy Technology Data Exchange (ETDEWEB)

Manno, D; Filippo, E; Fiore, R; Serra, A [Dipartimento di Scienza dei Materiali, Universita del Salento, Lecce (Italy); Urso, E; Rizzello, A; Maffia, M [Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Universita del Salento, Lecce (Italy)

2010-04-23

Surface-enhanced Raman spectroscopy (SERS) allows a new insight into the analysis of cell physiology. In this work, the difficulty of producing suitable substrates that, besides permitting the amplification of the Raman signal, do not interact with the biological material causing alteration, has been overcome by a combined method of hydrothermal green synthesis and thermal annealing. The SERS analysis of the cell membrane has been performed with special attention to the cellular prion protein PrP{sup C}. In addition, SERS has also been used to reveal the prion protein-Cu(II) interaction in four different cell models (B104, SH-SY5Y, GN11, HeLa), expressing PrP{sup C} at different levels. A significant implication of the current work consists of the intriguing possibility of revealing and quantifying prion protein expression in complex biological samples by a cheap SERS-based method, replacing the expensive and time-consuming immuno-assay systems commonly employed.

Monitoring prion protein expression in complex biological samples by SERS for diagnostic applications

International Nuclear Information System (INIS)

Manno, D; Filippo, E; Fiore, R; Serra, A; Urso, E; Rizzello, A; Maffia, M

2010-01-01

Surface-enhanced Raman spectroscopy (SERS) allows a new insight into the analysis of cell physiology. In this work, the difficulty of producing suitable substrates that, besides permitting the amplification of the Raman signal, do not interact with the biological material causing alteration, has been overcome by a combined method of hydrothermal green synthesis and thermal annealing. The SERS analysis of the cell membrane has been performed with special attention to the cellular prion protein PrP C . In addition, SERS has also been used to reveal the prion protein-Cu(II) interaction in four different cell models (B104, SH-SY5Y, GN11, HeLa), expressing PrP C at different levels. A significant implication of the current work consists of the intriguing possibility of revealing and quantifying prion protein expression in complex biological samples by a cheap SERS-based method, replacing the expensive and time-consuming immuno-assay systems commonly employed.

Nanosphere Templating Through Controlled Evaporation: A High Throughput Method For Building SERS Substrates

Science.gov (United States)

Alexander, Kristen; Hampton, Meredith; Lopez, Rene; Desimone, Joseph

2009-03-01

When a pair of noble metal nanoparticles are brought close together, the plasmonic properties of the pair (known as a ``dimer'') give rise to intense electric field enhancements in the interstitial gap. These fields present a simple yet exquisitely sensitive system for performing single molecule surface-enhanced Raman spectroscopy (SM-SERS). Problems associated with current fabrication methods of SERS-active substrates include reproducibility issues, high cost of production and low throughput. In this study, we present a novel method for the high throughput fabrication of high quality SERS substrates. Using a polymer templating technique followed by the placement of thiolated nanoparticles through meniscus force deposition, we are able to fabricate large arrays of identical, uniformly spaced dimers in a quick, reproducible manner. Subsequent theoretical and experimental studies have confirmed the strong dependence of the SERS enhancement on both substrate geometry (e.g. dimer size, shape and gap size) and the polarization of the excitation source.

SERS and DFT study of p-hydroxybenzoic acid adsorbed on colloidal silver particles.

Science.gov (United States)

Chen, Y; Chen, S J; Li, S; Wei, J J

2015-10-16

In this study, normal Raman spectra of p—hydroxybenzoic acid (PHBA) powder and its surface—enhanced Raman scattering (SERS) spectra in silver colloidal solutions were measured under near infrared excitation conditions. In theoretical calculation, two models of PHBA adsorbed on the surfaces of silver nanoparticles were established. The Raman frequencies of these two models using density functional theory (DFT) method were calculated, and compared with the experimental results. It was found that the calculated Raman frequencies were in good agreement with experimental values, which indicates that there are two enhanced mechanism physical (electromagnetic, EM) enhancement and chemical (charge—transfer, CT) enhancement, in silver colloidal solutions regarding SERS effect. Furthermore, from high—quality SERS spectrum of PHBA obtained in silver colloids, we inferred that PHBA molecules in silver colloids adsorb onto the metal surfaces through carboxyl at a perpendicular orientation. The combination of SERS spectra and DFT calculation is thus useful for studies of the adsorption—orientation of a molecule on a metal colloid.

Modification of the SERS spectrum of cyanide traces due to complex formation between cyanide and silver

Science.gov (United States)

Cao Dao, Tran; Kieu, Ngoc Minh; Quynh Ngan Luong, Truc; Cao, Tuan Anh; Hai Nguyen, Ngoc; Le, Van Vu

2018-06-01

It is well known that cyanide is an extremely toxic lethal poison with human death within minutes after exposure to only 300 ppm cyanide. On the other hand, cyanide is released into the environment (mainly through waste water) every day from various human activities. Therefore, rapid, sensitive and cost-effective cyanide trace detection is an urgent need. Surface-enhanced Raman scattering (SERS) is a method that meets these requirements. It should be noted, however, that in this technique SERS substrates, which are usually made of gold or silver, will be leached with aqueous cyanide by the formation of complexes between gold or silver with cyanide. This will cause the SERS spectrum of cyanide to be modified. When determining cyanide concentrations by SERS analysis, this spectral modification should be taken into account. This report presents the SERS spectral modification of aqueous cyanide traces (in ppm and lower concentration range) when the SERS substrates used are flower-like silver micro-structures.

Highly Sensitive Magnetic-SERS Dual-Function Silica Nanoprobes for Effective On-Site Organic Chemical Detection

Science.gov (United States)

Jeong, Cheolhwan; Kim, Hyung-Mo; Park, So Yeon; Cha, Myeong Geun; Park, Sung-Jun; Kyeong, San; Pham, Xuan-Hung; Hahm, Eunil; Ha, Yuna; Jeong, Dae Hong; Jun, Bong-Hyun; Lee, Yoon-Sik

2017-01-01

We report magnetic silver nanoshells (M-AgNSs) that have both magnetic and SERS properties for SERS-based detection. The M-AgNSs are composed of hundreds of Fe3O4 nanoparticles for rapid accumulation and bumpy silver shell for sensitive SERS detection by near-infrared laser excitation. The intensity of the SERS signal from the M-AgNSs was strong enough to provide single particle-level detection. We obtained much stronger SERS signal intensity from the aggregated M-AgNSs than from the non-aggregated AgNSs. 4-Fluorothiophenol was detected at concentrations as low as 1 nM, which corresponds to 0.16 ppb. The limit of detection for tetramethylthiuram disulfide was 10 μM, which corresponds to 3 ppm. The M-AgNSs can be used to detect trace amounts of organic molecules using a portable Raman system. PMID:28608835

Highly Sensitive Magnetic-SERS Dual-Function Silica Nanoprobes for Effective On-Site Organic Chemical Detection

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Cheolhwan Jeong

2017-06-01

Full Text Available We report magnetic silver nanoshells (M-AgNSs that have both magnetic and SERS properties for SERS-based detection. The M-AgNSs are composed of hundreds of Fe3O4 nanoparticles for rapid accumulation and bumpy silver shell for sensitive SERS detection by near-infrared laser excitation. The intensity of the SERS signal from the M-AgNSs was strong enough to provide single particle-level detection. We obtained much stronger SERS signal intensity from the aggregated M-AgNSs than from the non-aggregated AgNSs. 4-Fluorothiophenol was detected at concentrations as low as 1 nM, which corresponds to 0.16 ppb. The limit of detection for tetramethylthiuram disulfide was 10 μM, which corresponds to 3 ppm. The M-AgNSs can be used to detect trace amounts of organic molecules using a portable Raman system.

Neighboring phosphoSer-Pro motifs in the undefined domain of IRAK1 impart bivalent advantage for Pin1 binding.

Science.gov (United States)

Rogals, Monique J; Greenwood, Alexander I; Kwon, Jeahoo; Lu, Kun Ping; Nicholson, Linda K

2016-12-01

The peptidyl prolyl isomerase Pin1 has two domains that are considered to be its binding (WW) and catalytic (PPIase) domains, both of which interact with phosphorylated Ser/Thr-Pro motifs. This shared specificity might influence substrate selection, as many known Pin1 substrates have multiple sequentially close phosphoSer/Thr-Pro motifs, including the protein interleukin-1 receptor-associated kinase-1 (IRAK1). The IRAK1 undefined domain (UD) contains two sets of such neighboring motifs (Ser131/Ser144 and Ser163/Ser173), suggesting possible bivalent interactions with Pin1. Using a series of NMR titrations with 15N-labeled full-length Pin1 (Pin1-FL), PPIase, or WW domain and phosphopeptides representing the Ser131/Ser144 and Ser163/Ser173 regions of IRAK1-UD, bivalent interactions were investigated. Binding studies using singly phosphorylated peptides showed that individual motifs displayed weak affinities (> 100 μm) for Pin1-FL and each isolated domain. Analysis of dually phosphorylated peptides binding to Pin1-FL showed that inclusion of bivalent states was necessary to fit the data. The resulting complex model and fitted parameters were applied to predict the impact of bivalent states at low micromolar concentrations, demonstrating significant affinity enhancement for both dually phosphorylated peptides (3.5 and 24 μm for peptides based on the Ser131/Ser144 and Ser163/Ser173 regions, respectively). The complementary technique biolayer interferometry confirmed the predicted affinity enhancement for a representative set of singly and dually phosphorylated Ser131/Ser144 peptides at low micromolar concentrations, validating model predictions. These studies provide novel insights regarding the complexity of interactions between Pin1 and activated IRAK1, and more broadly suggest that phosphorylation of neighboring Ser/Thr-Pro motifs in proteins might provide competitive advantage at cellular concentrations for engaging with Pin1. © 2016 Federation of European

Ser respetuoso es ser persona. El niño y la pedagogía moral de los nahuas del centro de México

Directory of Open Access Journals (Sweden)

Lorente Fernández, David

2012-12-01

diversas actividades cotidianas. A pesar de estar sometidos al respeto «mestizo» transmitido en el interior de las escuelas, entre los niños la moralidad nahua se impone como algo «dado» y constitutivo de la manera de ser serrana.

La crítica de Hicks al Tratado del Dinero de Keynes

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Alexander Tobón

2004-12-01

Full Text Available El objetivo de este artículo es mostrar que la crítica que hace Hicks al Tratado del Dinero de Keynes es incorrecta. Para ello, presentamos el modelo de Keynes, mostrando que la igualdad entre la inversión y el ahorro es una condición de equilibrio monetario y no una identidad. Este resultado no puede ser obtenido en el análisis de Hicks.

Determinación de la absorción de haz láser en ensayos de refusión en régimen continuo

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Lima, M.

1998-04-01

Full Text Available Not available

[pt] Este trabalho estuda a absorção do feixe laser sobre a superfície de um ferro fundido branco por meio de ensaios calorimétricos. Um láser de CO₂, trabalhando no modo contínuo, foi utilizado para produzir um traço refundido sobre a superfície de um ferro fundido branco em intervalos de velocidade de varredura do feixe entre 0,01 e 1,00 cm/s. O registro da temperatura em função do tempo foi realizada por três termopares fixados à superfície inferior da amostra. Verificou-se que cerva de 13 % da radiação incidente sobre a superfície da amostra é absorvida em forma de calor, para um feixe com 0,65 mm de diâmetro, idependentemente da velocidade de varredura do feixe. No caso do feixe com diâmetro de 1,11 mm, a absorção cai para cerca de 11 %. [es] Se estudia la absorción del rayo láser por la superficie de una fundición blanca utilizando ensayos calorimétricos. Se utilizó un láser tipo CO₂ trabajando en modo continuo. Se realizaron trazos refundidos continuos en la superficie de la fundición blanca con velocidad de desplazamiento del haz láser comprendida entre 0,01 y 1,00 cm/s. Para el registro de la temperatura en función del tiempo se utilizaron tres termopares colocados sobre la superficie de la muestra. Se comprobó que, aproximadamente, el 13 % de la radiación incidente sobre la superficie de la muestra es absorbida en forma de calor, para un haz láser de 0,65 mm de diámetro, independientemente de la velocidad de paso del mismo. En el caso del haz láser de 1,11 mm de diámetro, la absorción disminuye a valores próximos al 11 %.

SERS and in situ SERS spectroscopy of riboflavin adsorbed on silver, gold and copper substrates. Elucidation of variability of surface orientation based on both experimental and theoretical approach

Science.gov (United States)

Dendisová-Vyškovská, Marcela; Kokaislová, Alžběta; Ončák, Milan; Matějka, Pavel

2013-04-01

Surface-enhanced Raman scattering and in situ surface-enhanced Raman scattering spectra have been collected to study influences of (i) used metal and (ii) applied electrode potential on orientation of adsorbed riboflavin molecules. Special in situ SERS spectroelectrochemical cell was used to obtain in situ SERS spectra of riboflavin adsorbed on silver, gold and copper nanostructured surfaces. Varying electrode potential was applied in discrete steps forming a cycle from positive values to negative and backward. Observed spectral features in in situ SERS spectra, measured at alternate potentials, have been changing very significantly and the spectra have been compared with SERS spectra of riboflavin measured ex situ. Raman spectra of single riboflavin molecule in the vicinity to metal (Ag, Au and Cu) clusters have been calculated for different mutual positions. The results demonstrate significant changes of bands intensities which can be correlated with experimental spectra measured at different potentials. Thus, the orientation of riboflavin molecules adsorbed on metal surfaces can be elucidated. It is influenced definitely by the value of applied potential. Furthermore, the riboflavin adsorption orientation on the surface depends on the used metal. Adsorption geometries on the copper substrates are more diverse in comparison with the orientations on silver and gold substrates.

SERS and DFT study of copper surfaces coated with corrosion inhibitor

Directory of Open Access Journals (Sweden)

Maurizio Muniz-Miranda

2014-12-01

Full Text Available Azole derivatives are common inhibitors of copper corrosion due to the chemical adsorption occurring on the metal surface that gives rise to a protective film. In particular, 1,2,4-triazole performs comparable to benzotriazole, which is much more widely used, but is by no means an environmentally friendly agent. In this study, we have analyzed the adsorption of 1,2,4-triazole on copper by taking advantage of the surface-enhanced Raman scattering (SERS effect, which highlights the vibrational features of organic ligand monolayers adhering to rough surfaces of some metals such as gold, silver and copper. To ensure the necessary SERS activation, a roughening procedure was implemented on the copper substrates, resulting in nanoscale surface structures, as evidenced by microscopic investigation. To obtain sufficient information on the molecule–metal interaction and the formation of an anticorrosive thin film, the SERS spectra were interpreted with the aid of theoretical calculations based on the density functional theory (DFT approach.

Surface-Enhanced Raman Scattering (SERS) for Detection in Immunoassays: applications, fundamentals, and optimization

International Nuclear Information System (INIS)

Jeremy Daniel Driskell

2006-01-01

Immunoassays have been utilized for the detection of biological analytes for several decades. Many formats and detection strategies have been explored, each having unique advantages and disadvantages. More recently, surface-enhanced Raman scattering (SERS) has been introduced as a readout method for immunoassays, and has shown great potential to meet many key analytical figures of merit. This technology is in its infancy and this dissertation explores the diversity of this method as well as the mechanism responsible for surface enhancement. Approaches to reduce assay times are also investigated. Implementing the knowledge gained from these studies will lead to a more sensitive immunoassay requiring less time than its predecessors. This dissertation is organized into six sections. The first section includes a literature review of the previous work that led to this dissertation. A general overview of the different approaches to immunoassays is given, outlining the strengths and weaknesses of each. Included is a detailed review of binding kinetics, which is central for decreasing assay times. Next, the theoretical underpinnings of SERS is reviewed at its current level of understanding. Past work has argued that surface plasmon resonance (SPR) of the enhancing substrate influences the SERS signal; therefore, the SPR of the extrinsic Raman labels (ERLs) utilized in our SERS-based immunoassay is discussed. Four original research chapters follow the Introduction, each presented as separate manuscripts. Chapter 2 modifies a SERS-based immunoassay previously developed in our group, extending it to the low-level detection of viral pathogens and demonstrating its versatility in terms of analyte type, Chapter 3 investigates the influence of ERL size, material composition, and separation distance between the ERLs and capture substrate on the SERS signal. This chapter links SPR with SERS enhancement factors and is consistent with many of the results from theoretical treatments

Surface-Enhanced Raman Scattering (SERS) for Detection in Immunoassays. Applications, fundamentals, and optimization

Energy Technology Data Exchange (ETDEWEB)

Driskell, Jeremy Daniel [Iowa State Univ., Ames, IA (United States)

2006-08-09

Immunoassays have been utilized for the detection of biological analytes for several decades. Many formats and detection strategies have been explored, each having unique advantages and disadvantages. More recently, surface-enhanced Raman scattering (SERS) has been introduced as a readout method for immunoassays, and has shown great potential to meet many key analytical figures of merit. This technology is in its infancy and this dissertation explores the diversity of this method as well as the mechanism responsible for surface enhancement. Approaches to reduce assay times are also investigated. Implementing the knowledge gained from these studies will lead to a more sensitive immunoassay requiring less time than its predecessors. This dissertation is organized into six sections. The first section includes a literature review of the previous work that led to this dissertation. A general overview of the different approaches to immunoassays is given, outlining the strengths and weaknesses of each. Included is a detailed review of binding kinetics, which is central for decreasing assay times. Next, the theoretical underpinnings of SERS is reviewed at its current level of understanding. Past work has argued that surface plasmon resonance (SPR) of the enhancing substrate influences the SERS signal; therefore, the SPR of the extrinsic Raman labels (ERLs) utilized in our SERS-based immunoassay is discussed. Four original research chapters follow the Introduction, each presented as separate manuscripts. Chapter 2 modifies a SERS-based immunoassay previously developed in our group, extending it to the low-level detection of viral pathogens and demonstrating its versatility in terms of analyte type, Chapter 3 investigates the influence of ERL size, material composition, and separation distance between the ERLs and capture substrate on the SERS signal. This chapter links SPR with SERS enhancement factors and is consistent with many of the results from theoretical treatments

Al sonido lo voy convirtiendo en ser

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Santiago Yahuarcani

2014-09-01

Full Text Available De niño travieso a pintor de sonidos, el testimonio de Santiago Yahuarcani conmueve por su sentido del humor y su inusitado recorrido. Sus experimentos infantiles solitarios con unos hongos que encontraba en el camino a la chacra de su madre, le sirvieron, años más tarde, de fuente de inspiración para crear nuevas figuras y sustentar a sus propios hijos con la venta de su arte. Nacido con madre uitoto y padre cocama, Santiago siguió, sin saberlo, los pasos de Fídoma, el héroe de la historia oral del clan Aymenu que coloreó todos los seres de la selva. Santiago, coloreó inclusive, sus sonidos. 

FACTORES INTERVINIENTES EXTERNOS A LA ORGANIZACIÓN ASOCIADOS AL ÉXITO GERENCIAL EN LA EMPRESA: “SUPLIDORA DEL CARIBE, C.A.”.

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Karin Silvestri

2009-04-01

cincuenta empresas en el sector de los químicos similares y conexas existentes en la Región Zuliana ubicadas en la Costa Oriental y Occidental del Lago, arrojando una muestra de veinte compañías a través de un muestreo probabilístico–aleatorio; aplicándoles el instrumento denominado cuestionario que permita el análisis, descripción e identificación exhaustiva de los factores mencionados asociados al éxito gerencial, a través de conductas gerenciales que permitan impulsar virtualmente un programa detallado de éxito tanto para él como para la organización que dirige, a través de las estrategias que involucran las fuerzas que deben ser utilizadas; las limitaciones que deben ser minimizadas; las oportunidades que deben ser aprovechadas y las amenazas que deben ser controladas.

Applications of the surface enhanced Raman scattering (SERS)

International Nuclear Information System (INIS)

Picquart, M.; Haro P, E.; Bernard, S.

2007-01-01

Full text: Vibration spectroscopy techniques are used for many times to identify substances, determine molecular structure and quantify them, independently of their physical state. Raman spectroscopy as infrared absorption permit to access the vibration energy levels of molecules. In the second case, the permanent dipolar moment is involved while in the first one it is the polarizability (and the induced dipolar moment). Unfortunately, the classical Raman spectroscopy is low sensitive in particular in the case of biological molecules. On the opposite, the surface enhanced Raman spectroscopy (SERS) offers great potentialities. In this case, the molecules are adsorbed on a rough surface or on nanoparticles of gold or silver and the: signal can be increased by a factor of 10 7 to 10 8 . Moreover, the spectral enhancement is greater for the vibrations of the functional group of the molecule adsorbed on the substrate. In this work, we present the main theoretical bases of SERS, and some results obtain on different systems. (Author)

Ser do tempo em Bergson

OpenAIRE

Coelho,Jonas Gonçalves

2004-01-01

O artigo apresenta a concepção bergsoniana de duração. Pretende-se mostrar que, segundo Bergson, o tempo dos filósofos e cientistas é um tempo fictício, um esquema espacial que oculta a natureza do tempo real, o qual não pode ser separado dos acontecimentos físicos e psicológicos. Para Bergson, o tempo real é sucessão, continuidade, mudança, memória e criação. El presente artículo trata de la concepción bergsoniana de duración. Pretendemos mostrar que, según Bergson, el tiempo de los filós...

EXPERIENCIAS RELACIONADAS A UNA INTERVENCIÓN PARA REDUCIR EL ESTIGMA RELACIONADO AL VIH/SIDA ENTRE ESTUDIANTES DE MEDICINA EN PUERTO RICO

OpenAIRE

Cintrón-Bou, Francheska; Varas-Díaz, Nelson; Marzán-Rodríguez, Melissa; Neilands, Torsten B.

2016-01-01

Existe estigma relacionado al VIH. A las personas con VIH/SIDA-PCVS se les viola sus derechos y obstaculiza su bienestar mental/físico. Profesionales de la salud-PS son fuente de apoyo primordial, sin embargo estos/as le estigmatizan. Es útil adiestrar a PS en relación al estigma social. Implantamos la intervención para reducir el estigma relacionado al VIH/SIDA con 507 estudiantes de medicina. Resultó ser una intervención efectiva, hubo reducción en los niveles de estigma a partir de nuestra...

“INSEGUROS, POBRES Y FELICES”. LA SEGURIDAD PRIVADA COMO RESPUESTA AL INCREMENTO DE LA PERCEPCIÓN DE INSEGURIDAD CIUDADANA EN PARAGUAY

OpenAIRE

Carlos Aníbal Peris Castiglioni; Sarah Patricia Cerna Villagra

2015-01-01

En Paraguay uno puede sentirse inseguro, ser pobre pero a la vez ser feliz, al menos así lo demuestran las encuestas de opinión sobre esta nación sudamericana. Para comprender la curiosa afirmación, el presente trabajo tiene como objetivo relacionar los factores de: a) el incremento de la percepción de inseguridad ciudadana con; b) altos niveles de pobreza y desigualdad y; c) deficientes capacidades estatales con la expansión de la seguridad corporativa en Paraguay. Entre los principales h...

The BARD1 Cys557Ser variant and breast cancer risk in Iceland.

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Simon N Stacey

2006-07-01

Full Text Available Most, if not all, of the cellular functions of the BRCA1 protein are mediated through heterodimeric complexes composed of BRCA1 and a related protein, BARD1. Some breast-cancer-associated BRCA1 missense mutations disrupt the function of the BRCA1/BARD1 complex. It is therefore pertinent to determine whether variants of BARD1 confer susceptibility to breast cancer. Recently, a missense BARD1 variant, Cys557Ser, was reported to be at increased frequencies in breast cancer families. We investigated the role of the BARD1 Cys557Ser variant in a population-based cohort of 1,090 Icelandic patients with invasive breast cancer and 703 controls. We then used a computerized genealogy of the Icelandic population to study the relationships between the Cys557Ser variant and familial clustering of breast cancer.The Cys557Ser allele was present at a frequency of 0.028 in patients with invasive breast cancer and 0.016 in controls (odds ratio [OR] = 1.82, 95% confidence interval [CI] 1.11-3.01, p = 0.014. The alleleic frequency was 0.037 in a high-predisposition group of cases defined by having a family history of breast cancer, early onset of breast cancer, or multiple primary breast cancers (OR = 2.41, 95% CI 1.22-4.75, p = 0.015. Carriers of the common Icelandic BRCA2 999del5 mutation were found to have their risk of breast cancer further increased if they also carried the BARD1 variant: the frequency of the BARD1 variant allele was 0.047 (OR = 3.11, 95% CI 1.16-8.40, p = 0.046 in 999del5 carriers with breast cancer. This suggests that the lifetime probability of a BARD1 Cys557Ser/BRCA2 999del5 double carrier developing breast cancer could approach certainty. Cys557Ser carriers, with or without the BRCA2 mutation, had an increased risk of subsequent primary breast tumors after the first breast cancer diagnosis compared to non-carriers. Lobular and medullary breast carcinomas were overrepresented amongst Cys557Ser carriers. We found that an excess of ancestors

Micro-nano zinc oxide film fabricated by biomimetic mineralization: Designed architectures for SERS substrates

Science.gov (United States)

Lu, Fei; Guo, Yue; Wang, Yunxin; Song, Wei; Zhao, Bing

2018-05-01

In this study, we have investigated the effect of the surface morphologies of the zinc oxide (ZnO) substrates on surface enhanced Raman spectroscopy (SERS). During synthetic process, the self-assembly monolayers (SAMs) with different terminal groups are used as templates to induce the nucleation and growth of Zn(NO3)2·6H2O crystals, then different morphologies micro-nano ZnO powders are obtained by annealing Zn(NO3)2·6H2O crystals at 450 °C. The products obtained at different conditions are characterized by means of X-ray diffraction (XRD) patterns, scanning electron microscopy (SEM) and Raman spectra. The as-prepared ZnO micro-sized particles have been used the efficient Surface enhanced Raman scattering (SERS) substrates, and the SERS signals of 4-mercaptopyridine (Mpy) probe molecules are much influenced by the morphologies of the ZnO structures. Results indicated that the more (0001) facets appear in the of ZnO morphology, the greater degree of charge-transfer (PCT) for the SERS enhancement on the surface of semiconductors is achieved. The chemical interaction between ZnO structures and Mpy molecules plays a very important role in the SERS enhancement.

Una ventana al mundo de Kafka.

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Guillermo Sánchez Medina

2003-03-01

Full Text Available

COMENTARIO AL LIBRO " EL MUNDO PSICOLÓGICO DE KAFKA" POR EL ACADÉMICO ADOLFO DE FRANCISCO ZEA.

Fui invitado en forma comedida, por el doctor Adolfo De Francisco, para comentar su obra: "El Mundo Psicológico de Kafka". Respondí que no era literato y menos crítico de Kafka. Sin embargo, acepté
hacerlo siendo consciente de las limitaciones que me acompañan y para las que pido de todos ustedes su consideración. Tenía sí el deseo al reto de lo incógnito.
Además sus argumentos fueron contundentes, pues se referían al compromiso con la Academia y, sin decírmelo, era también con él en nuestra historia compartida. Mis motivaciones y expectativas personales conscientes eran múltiples para sumergirme en sus ideas que mueven el espíritu desde la piel a lo trascendente, de lo interno a lo externo y viceversa, y en que cada palabra puede ser objeto de análisis profundo, pues esa es su esencia. Por ejemplo cuando el doctor De Francisco se refiere a la sublimación y a la estética, a la política, a la religiosidad, a la burguesía, al campesinado, a la nobleza, al absolutismo, al arte o a la historia, a la cosmovisión sociológica y literaria, al psicoanálisis para afrontar la realidad interna y externa, entonces el autor penetra en el mundo de la fantasía y del psiquismo, para entender el simbolismo implícito de Kafka.
Las motivaciones personales inconscientes, pertenecen a las tendencias irracionales de hundirme en espacios complejos para luego intentar'ordenarlos; en medio está
la contratransferencia que me une con el autor Adolfo De Francisco y otra la que se refiere a la temática kafkiana...

Physikalische Grundlagen von chemischen Raman-Sensoren mit Schwerpunkt auf faseroptischen SERS-Sonden

OpenAIRE

Viets, Carmen

2001-01-01

Faseroptische SERS-Sensoren wurden durch die Beschichtung der Endflächen von optischen Fasern mit rauhen Metallfilmen erzeugt. Zu den verschiedenen Präparationstechniken, die angewendet und verglichen wurden, gehörten das langsame Aufdampfen von Metall-Inselfilmen und das Bedampfen von Nanopartikeln, aufgerauhten oder elektronenlithographisch strukturierten Oberflächen mit Metallfilmen. Der Einfluß der Laserleistung auf die Messungen mit SERS-Sensoren wurde untersucht, und es wurden maximale ...

Exponerse o ser expuesto : la revolución expositiva de las vanguardias históricas

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María Ángeles Layuno Rosas

1997-01-01

Full Text Available Desde los comienzos del siglo xx emerge con fuerza la voluntad, por parte de los artistas de los diferentes «ismos» de determinar las formas y lugares en que llevar a cabo la presentación de sus obras al público, con el fin de asegurar la transmisión de unos contenidos artísticos e ideológicos. Junto al medio literario — manifiesto—, será el expositivo, la vía de transmisión artística por excelencia de las vanguardias históricas. A la vez que estos movimientos supusieron una ruptura radical desde el punto de vista estético respecto al arte del pasado, también desarrollaron nuevas experiencias museográficas —cuyas consecuencias han llegado tiasta nuestros días. En este proceso, se establece una relación conflictiva con el museo, que marca la tónica de una época de cuestionamiento y transformación de la institución.The intention to determine the patterns and places where show their works to the public was spread by the artists of the different avant-garde artistic mouvements, from the beggining of our century. By this way, they ensure the transmisión of an ideological and artistic concepts. The exhibition practice will be, together with the literary texts —Manifestó—, the main vehicle for modern artists to communicate their aesthetic programs. These mouvements involved a radical aesthetic breaking in relation to the traditional art, and, at the same time, they developped revolutionary museographic experiences, whose consequences have reached the present days.

Análisis de la crítica social al marketing

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Raymond Prada Daza

2002-01-01

Full Text Available Cada vez un mayor número de analistas y críticos sociales asocian el marketing con el consumo exagerado, y afirman que las empresas a menudo planifican la obsolescencia de sus productos con el ánimo de que los compradores adquieran nuevas versiones que incorporan muy pocas mejoras funcionales. Pero, además, aseveran que la publicidad agrega demasiados costos al precio de los productos y que la ganancia bruta de los fabricantes es exagerada. Las críticas se extienden al señalamiento de abusos en el poder político de algunos grupos de industrias y a la discriminación de distritos habitados por familias de bajos ingresos. Al compás de las respuestas de los mercadólogos, los consumidores se organizan y cobra relevancia el concepto de que el marketing debe ser socialmente responsable y que los compradores potenciales pueden educar sus deseos más superfluos y caprichosos.

La teoría de la alóstasis como mecanismo explicativo entre los apegos inseguros y la vulnerabilidad a enfermedades crónicas

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Mariantonia Lemos

2015-05-01

Full Text Available El vínculo de apego ha mostrado ser un factor de vulnerabilidad para las enfermedades crónicas. El presente artículo busca clarificar esta relación mediante la teoría de la alóstasis. La teoría de la alóstasis hace referencia a la regulación de los procesos fisiológicos corporales complejos en el tiempo mediante una respuesta sistémica que mantiene la estabilidad fisiológica cuando se confronta la persona con cambios o retos. Los apegos inseguros confrontan a los niños desde sus primeros años con eventos estresantes, al no brindar al niño la seguridad sentida, finalidad fundamental del apego. De esta forma los apegos inseguros podrían tener impacto en la calibración del sistema de estrés en la edad temprana y serían factores de aumento de la carga alostática mediante mayores eventos vitales estresantes que las personas con apego seguro, una valoración cognitiva de amenaza que lleva al desarrollo de la hipervigilancia y el impacto en los sistemas de regulación del estrés en el cuerpo.

Biofabrication of chitosan-silver composite SERS substrates enabling quantification of adenine by a spectroscopic shift

International Nuclear Information System (INIS)

Luo, X L; Bentley, W E; Buckhout-White, S; Rubloff, G W

2011-01-01

Surface-enhanced Raman scattering (SERS) has grown dramatically as an analytical tool for the sensitive and selective detection of molecules adsorbed on nano-roughened noble metal structures. Quantification with SERS based on signal intensity remains challenging due to the complicated fabrication process to obtain well-dispersed nanoparticles and well-ordered substrates. We report a new biofabrication strategy of SERS substrates that enable quantification through a newly discovered spectroscopic shift resulting from the chitosan-analyte interactions in solution. We demonstrate this phenomenon by the quantification of adenine, which is an essential part of the nucleic acid structure and a key component in pathways which generate signal molecules for bacterial communications. The SERS substrates were fabricated simply by sequential electrodeposition of chitosan on patterned gold electrodes and electroplating of a silver nitrate solution through the chitosan scaffold to form a chitosan-silver nanoparticle composite. Active SERS signals of adenine solutions were obtained in real time from the chitosan-silver composite substrates with a significant concentration-dependent spectroscopic shift. The Lorentzian curve fitting of the dominant peaks suggests the presence of two separate peaks with a concentration-dependent area percentage of the separated peaks. The chitosan-mediated composite SERS substrates can be easily biofabricated on predefined electrodes within microfluidic channels for real-time detection in microsystems.

Paper membrane-based SERS platform for the determination of glucose in blood samples.

Science.gov (United States)

Torul, Hilal; Çiftçi, Hakan; Çetin, Demet; Suludere, Zekiye; Boyacı, Ismail Hakkı; Tamer, Uğur

2015-11-01

In this report, we present a paper membrane-based surface-enhanced Raman scattering (SERS) platform for the determination of blood glucose level using a nitrocellulose membrane as substrate paper, and the microfluidic channel was simply constructed by wax-printing method. The rod-shaped gold nanorod particles were modified with 4-mercaptophenylboronic acid (4-MBA) and 1-decanethiol (1-DT) molecules and used as embedded SERS probe for paper-based microfluidics. The SERS measurement area was simply constructed by dropping gold nanoparticles on nitrocellulose membrane, and the blood sample was dropped on the membrane hydrophilic channel. While the blood cells and proteins were held on nitrocellulose membrane, glucose molecules were moved through the channel toward the SERS measurement area. Scanning electron microscopy (SEM) was used to confirm the effective separation of blood matrix, and total analysis is completed in 5 min. In SERS measurements, the intensity of the band at 1070 cm(-1) which is attributed to B-OH vibration decreased depending on the rise in glucose concentration in the blood sample. The glucose concentration was found to be 5.43 ± 0.51 mM in the reference blood sample by using a calibration equation, and the certified value for glucose was 6.17 ± 0.11 mM. The recovery of the glucose in the reference blood sample was about 88 %. According to these results, the developed paper-based microfluidic SERS platform has been found to be suitable for use for the detection of glucose in blood samples without any pretreatment procedure. We believe that paper-based microfluidic systems may provide a wide field of usage for paper-based applications.

El conductismo y algunas implicaciones de lo que significa ser conductista hoy

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Camilo Hurtado

2006-01-01

Full Text Available Se discuten varios aspectos relacionados con el conductismo, sus múltiples versiones, una definición amplia de éste y a quienes se les puede denominar actualmente “conductistas”. Además, a partir de una anécdota se analiza, en términos de barreras epistemológicas, el rechazo a esta tradición de pensamiento y se discute como dicho rechazo está enraizado y mantenido en una serie de malentendidos y en las contradicciones que existen entre los principios del conductismo genérico y los de la llamada “resto de la psicología” o “mainstream psychology” la cual se caracteriza por diversas formas de cognoscitivismo y ser muy afín con la que se ha llamado “psicología popular”. Finalmente, se analizan algunas propuestas que han sido sugeridas para superar las barreras epistemológicas del conductismo, concluyendo que el contexto académico actual no es el apropiado para que estos intentos cumplan con su finalidad, en cambio, al parecer dicho contexto es fuente en sí mismo de otro tipo de barreras.

Foucault y su crítica al humanismo

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Ignacio Bárcenas Monroy

2007-01-01

Full Text Available El objetivo del presente trabajo es determinar el significado de la frase “la muerte del Hombre” en la filosofía contemporánea. Para ello se comienza por dar un panorama general del lugar que ocupa esta reflexión en la filosofía contemporánea. Después se muestra que, a partir de los análisis de Michel Foucault, el hombre es una invención reciente, pues no ha sido una constante en la historia del pensamiento. En seguida se describen aquellos saberes que tienen como objeto de estudio al hombre, mostrando que en lugar de darnos una respuesta sobre lo que éste sea, antes bien lo disuelven, más aún las ciencias humanas producen mecanismos de poder que normalizan a los seres humanos. Se concluye que una reflexión así planteada promueve la indagación de nuevas formas para pensar al ser humano, alejadas de un viejo humanismo.

Condiciones de favorabilidad al maternaje y violencia materna

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Mauricio Hernando Bedoya

2010-10-01

Full Text Available Realizamos un acercamiento al problema de las prácticas de violencia materna hacia los niños y niñas y su impacto en el vínculo materno-filial. Objetivo: reconocer en madres que se nombran como maltratadoras, y en sus hijos e hijas maltratados, el significado dado a su vínculo afectivo. Método: fenomenológico-hermenéutico del enfoque cualitativo con muestra multinivel. Técnicas de Producción de Información: entrevistas en profundidad con madres, grupos focales con sus hijos e hijas y con madres y padres de tres instituciones educativas. Conclusiones: las madres explican la violencia hacia sus hijos e hijas acudiendo a una cadena vincular generacional con su propia madre; las condiciones de favorabilidad al maternaje adversas predicen tal violencia; no todo niño o niña violentado será padre violento o madre violenta y, finalmente, postulamos que existe una tipología de madre violenta.

Using Ag-embedded TiO{sub 2} nanotubes array as recyclable SERS substrate

Energy Technology Data Exchange (ETDEWEB)

Ling, Yunhan, E-mail: yhling@mail.tsinghua.edu.cn [Lab of Advanced Materials, School of Materials Science & Engineering, Tsinghua University, Beijing 100084 (China); Zhuo, Yuqing; Huang, Liang [Lab of Advanced Materials, School of Materials Science & Engineering, Tsinghua University, Beijing 100084 (China); Mao, Duolu [School of Physical and Electronic Information Engineering, Qinghai Nationalities University, Xining, Qinghai 810007 (China)

2016-12-01

Highlights: • Ag embedded nanoparticles inside nanotube have better SERS enhancement than surface cap. • Ag NPs reconstruction via self-migration with UV and humidity control. • Self-cleaning effects both on organic molecule photo-oxidation as well as Ag ions photo-reduction. - Abstract: A simple strategy for synthesizing Ag-loaded TiO{sub 2} nanotube film for use as multifunctional photocatalyst and recyclable surface-enhanced Raman scattering (SERS) substrate is introduced. Highly aligned TiO{sub 2} nanotube arrays (TNTA) prepared via electrochemical anodization were used as a 3D rough host for silver nanoparticles. Ag deposits were sputtered in a vacuum, and it was found that their morphologies were mainly influenced by the diameters of nanotubes and the UV irradiation induced aging process, especially the self-migration of silver along the tubular wall. SERS and the self-cleaning effect were observed using Rhodamine 6G (R6G) as the probe molecule. The results showed that narrow nanotube and silver nanoparticles embedment contributed significantly to both the phenomenal SERS and recyclability.

Las limitaciones al financiamiento bancario de las Pymes de alta tecnología

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M. Belén Guercio

2017-01-01

Full Text Available El objetivo de este trabajo es analizar el efecto del grado de intensidad tecnológica asociado a las Pymes en el acceso al financiamiento. Por lo tanto, se estima un modelo Logit ordenado considerando un conjunto de variables independientes como el tamaño de la empresa, la antigüedad, la capacidad exportadora y la intensidad tecnológica asociada al sector. Los resultados obtenidos muestran que la intensidad tecnológica de la empresa resulta ser la variable que más impacta en la probabilidad de financiarse en el sector bancario. Esta conclusión es relevante para Argentina, dado que, a diferencia de otros países emergentes, las empresas no cuentan con instrumentos alternativos al financiamiento bancario que se adapten a las características propias de las Pymes de alta tecnología.

Project W-320, waste retrieval sluicing system: BIO/SER implementation matrices

International Nuclear Information System (INIS)

Bailey, J.W.

1998-01-01

This document provides verification that the safety related commitments specified in HNF-SD-WM-810-001, Addendum 1 for the Waste Retrieval Sluicing System, Project W-320 and Project W-320 Safety Evaluation Report (SER), have been implemented in the project hardware, procedures and administrative controls. Four appendices include matrices which show where the 810 commitments are implemented for limiting conditions of operation and surveillance requirements controls, administrative controls, defense-in-depth controls and controls discussed in 810 Addendum 1. A fifth appendix includes the implementation of Project W-320 SER issues and provisions

on Ti6AL4V for biomedical applications

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Juan José Pavón

2006-01-01

Full Text Available La fijación al tejido receptor de implantes para el reemplazo de hueso puede ser mejorada si poseen una superficie bioactiva con la capacidad de precipitar hidroxiapatita in vivo. Las aleaciones de titanio, a pesar de sus buenas propiedades mecánicas y comportamiento no-tóxico, no son bioactivas y, por tanto, no se enlazan directamente al hueso. Una de las maneras de modificar una superficie metálica bioinerte es recubriéndola con material bioactivo. En este trabajo se presenta la evaluación del comportamiento a fatiga mediante indentación hertziana (esférica de un recubrimiento de vidrio sobre Ti6Al4V. Este recubrimiento pertenece al sistema SiO2-CaO-MgO-Na2O-K2O-P2O5 y, a pesar de que puede usarse para protección contra la corrosión, ha sido específicamente diseñado para ser utilizado como capa interna de un recubrimiento bicapa bioactivo con una capa externa de bajo contenido en SiO2 para garantizar la bioactividad. Los ensayos hertzianos monotónicos permitieron obtener una secuencia de daños comenzando con tres eventos de daño tipo frágil (agrietamiento tipo anillo, cono y radial seguidos por la delaminación del recubrimiento asociada a la deformación plástica del substrato. El primer daño frágil, el agrietamiento tipo anillo, fue usado como criterio para la evaluación del agrietamiento por corrosión bajo tensión y por carga cíclica, en aire y agua destilada. Los resultados mostraron la sensibilidad del recubrimiento a la degradación bajo ambos tipos de carga, estática y cíclica, siendo esta degradación considerablemente mayor en agua destilada debido a la susceptibilidad del vidrio a la corrosión. La delaminación fue también sensible a la carga cíclica hertziana presentando dos mecanismos diferentes dependiendo de la máxima carga aplicada.

SERS activity with tenfold detection limit optimization on a type of nanoporous AAO-based complex multilayer substrate

Science.gov (United States)

Sui, Chaofan; Wang, Kaige; Wang, Shuang; Ren, Junying; Bai, Xiaohong; Bai, Jintao

2016-03-01

Most of SERS applications are constricted by heterogeneous hotspots and aggregates of nanostructure, which result in low sensitivity and poor reproducibility of characteristic signals. This work intends to introduce SERS properties of a type of SERS-active substrate, Au-CuCl2-AAO, which is innovatively developed on a porous anodic alumina oxide (AAO) template. Spectral measuring results of Rhodamine 6G (R6G) on this substrate optimized by controlling morphology and gold thickness showed that enhancement factor (2.30 × 107) and detection limit (10-10 M) were both improved and represented better performance than its template AAO. Homogenous hot spots across the region of interest were achieved by scanning SERS intensity distribution for the band at 1505 cm-1 in 5 × 5 μm2 area. Furthermore, the promising SERS activity of the flower-patterned substrate was theoretically explained through simulation of the electromagnetic field distribution. In addition, this SERS substrate is proposed for applications within the field of chemical and biochemical analyses.Most of SERS applications are constricted by heterogeneous hotspots and aggregates of nanostructure, which result in low sensitivity and poor reproducibility of characteristic signals. This work intends to introduce SERS properties of a type of SERS-active substrate, Au-CuCl2-AAO, which is innovatively developed on a porous anodic alumina oxide (AAO) template. Spectral measuring results of Rhodamine 6G (R6G) on this substrate optimized by controlling morphology and gold thickness showed that enhancement factor (2.30 × 107) and detection limit (10-10 M) were both improved and represented better performance than its template AAO. Homogenous hot spots across the region of interest were achieved by scanning SERS intensity distribution for the band at 1505 cm-1 in 5 × 5 μm2 area. Furthermore, the promising SERS activity of the flower-patterned substrate was theoretically explained through simulation of the

EFFECTS OF WEEVILS (INSECTA: COLEOPTERA: CURCULIONIDAE) CONTROL PRODUCTS, OVER THE GROWTH, DEVELOPMENT, AND PRODUCTION OF PLANTAIN

OpenAIRE

M. Muñoz, Liliana; Cañas, Guillermo L.; Urrea, Aura I.; Guarín, Juan H.

2013-01-01

In a farm in the municipality of Andes (Antioquia, Colombia), parcels were planted with Dominico Hartón plantain associated with Caturra-type coffee, where weevil damage (Insecta: Coleoptera: Curculionidae) occurred in 100% of the plantain plants, corms of approximately 2 kg were planted under the same association system. From the sowing until harvest, six types of products were applied every two months on these plantations: chemical of the region (Clorpirifos and Carboxin + Thiram), Carbofur...

[AgBr colloids prepared by electrolysis and their SERS activity research].

Science.gov (United States)

Si, Min-Zhen; Fang, Yan; Dong, Gang; Zhang, Peng-Xiang

2008-01-01

Ivory-white AgBr colloids were prepared by means of electrolysis. Two silver rods 1.0 cm in diameter and 10.0 cm long were respectively used as the negative and positive electrodes, the aqueous solution of hexadecyl trimethyl ammonium bromide was used as the electrolyte, and a 7 V direct current was applied on the silver rods for three hours. The obtained AgBr colloids were characterized by UV-Vis spectroscopy, transmission electron microscopy, and SERS using a 514. 5 nm laser line on Renishaw 2000 Raman spectrometer. These particles are about nanometer size and their shapes are as spherical or elliptic, with a slight degree of particle aggregation. The UV-Vis spectra exhibit a large plasmon resonance band at about 292.5 nm, similar to that reported in the literature. The AgBr colloids were very stable at room temperature for months. In order to test if these AgBr colloids can be used for SERS research, methyl orange, Sudan red and pyridine were used. It was found that AgBr colloids have SERS activity to these three molicules. For methyl orange, the intense Raman peaks are at 1 123, 1 146, 1 392, 1 448 and 1 594 cm(-1); for Sudan red, the intense Raman peaks are at 1 141, 1 179, 1 433 and 1 590 cm(-1); and for pyridine, the intense Raman peaks are at 1 003, 1 034 and 1 121 cm(-1). It is noticeable that SERS of methyl orange was observed on AgBr colloids, but not on the gray and yellow silver colloids prepared by traditional means. The possible reason was explained. One major advantage of this means is the absence of the spectral interference such as citrate, BH4- arising from reaction products of the colloids formation process. On AgBr colloids, one can get some molecular SERS impossible to get on the gray and yellow silver colloids.

DETERMINANTES DEL ACCESO AL CRÉDITO DE LOS HOGARES COLOMBIANOS

OpenAIRE

Andrés Murcia Pabón

2007-01-01

Este documento busca identificar los determinantes de acceso al crédito de los hogares colombianos y encuentra que características tales como el ingreso, la riqueza, la posición geográfica, el acceso a la seguridad social, el nivel de educación y la edad afectan la probabilidad de ser usuario de los servicios financieros acá analizados (tarjeta de crédito y crédito hipotecario). Adicionalmente se encontró que una porción importante de población cuenta con unas condiciones financieras favorabl...

On the chemical enhancement in SERS

Science.gov (United States)

Jensen, Lasse

2012-12-01

In Surface-enhanced Raman scattering (SERS), the Raman signal of a molecule adsorbed on a metal surface is enhanced by many orders of magnitude. This provides a "finger-print" of molecules which can be used in ultrasensitive sensing devises. Here we present a time-dependent density functional theory (TDDFT) study of the molecule-surface chemical coupling in SERS. A systematic study of the chemical enhancement (CHEM) of meta-and para-substituted pyridines interacting with a small silver cluster (Ag20) is presented. We find that the magnitude of chemical enhancement is governed to a large extent by the energy difference between the highest occupied energy level (HOMO) of the metal and the lowest unoccupied energy level (LUMO) of the molecule. A two-state approximation shows that the enhancement scales roughly as (ωX/ω¯e)4, where accent="true">ω¯e is an average excitation energy between the HOMO of the metal and the LUMO of the molecule and wX the HOMO-LUMO gap of the free molecule. Furthermore, we demonstrate that it is possible to control the CHEM enhancement by switching a dithienylethene photoswitch from its closed form to its open form. The open form of the photoswitch is found to be the strongest Raman scatterer when adsorbed on the surface whereas the opposite is found for the free molecule. This trend is explained using the simple two-state approximation.

Notas introdutórias sobre a Manualidade do mundo em “ser e tempo” (zuhandenheit

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Silva, Jayme Camargo da

2009-01-01

Full Text Available O filósofo Martin Heidegger explicitou que, a diferença específica entre a existência do homem (Dasein e a dos demais objetos da realidade – aos quais denominou como “Vorhandenheit” (entes intramundanos ou meramente subsistentes -, é que o homem ao existir na compreensão do ser, se autocompreende como ser-no-mundo que é, e assim torna possível a manifestação dos entes subsistentes (circulo hermenêutico. O processo operativo dos modos de ser da existência no cotidiano, se dá através da ocupação (Besorgen e se manifesta no “serem” constitutivo do modo de ser-no-mundo do homem

From Kitāb al-ḥadā’iq to Kitāb al-dawā’ir: Reconsidering Ibn al-Sīd al-Batalyawsī’s Philosophical Treatise

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Eliyahu, Ayala

2015-06-01

adscribe este tratado, teniendo en cuenta su texto, una revisión de los datos ya conocidos y la comparación entre este tratado y el resto de la producción de al-Batalyawsī. Como conclusión se propone, en primer lugar, que el Kitāb al-ḥadā’iq no es el título original del tratado, sino que debe ser Kitāb al-dawā’ir. Por otro lado, este Kitāb al-dawā’ir era originalmente parte (una de las versiones del Kitāb al-masā’il de al-Batalyawsī. En tercer lugar, las similitudes textuales y estilísticas entre este tratado con otras obras de al-Batalyawsī prueban su autoría. Además, el uso que al-Batalyawsī hace de fórmulas que ya encontramos en las Rasā’il Ikhwān al-Safā, y que aparecen en sus Kitāb al-ḥadā’iq y Kitāb al-masā’il, profundizan en la hipótesis del impacto que las Rasā’il causaron en el pensamiento del autor, así como en la estrecha conexión que existe entre el Kitāb al-ḥadā’iq y el Kitāb al-masā’il. De hecho, esta conexión resulta más clara cuando se atribuyen ambos tratados al género de «preguntas y respuestas» en la literatura árabe. Este artículo demuestra, por tanto, que el Kitāb al-dawā’ir de al-Batalyawsī debe entenderse como parte de su obra literaria y, así, como parte de la producción filosófica andalusí.

¿CUÁN LIVIANA PUEDE SER LA RISA? NIETZSCHE Y LEVINAS FRENTE AL "FIN DEL HOMBRE"

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Aïcha Liviana Messina

2012-01-01

Full Text Available El artículo parte de la siguiente lectura: en distintas ocasiones, Levinas se refiere al pensamiento de Nietzsche, a su risa, que "rechaza el lenguaje"; sorprendentemente, Levinas no sitúa a Nietzsche, a diferencia de Heidegger, como el último metafísico, sino que lo descoloca en esta historia, subrayando más bien la "extrema juventud" de la risa nietzscheana. Este artículo propone mostrar cómo la risa nietzscheana se articula con lo que Levinas llamaba una "subjetividad del sujeto inocente de conjunciones ontológicas". Se concluye con una reflexión sobre la vergüenza y los límites del hombre.

Un acercamiento al paradigma cuántico

OpenAIRE

Zapata Mesa, John Fernando

2009-01-01

En este breve escrito se hace algunos comentarios sobre la física cuántica con el objetivo de hacer un acercamiento al lector a este nuevo paradigma y de motivar una reflexión en esta línea.La física cuántica es la ciencia más desarrollada y mejor fundamentada hasta el momento junto con la teoría de la relatividad de Einstein. Toda la tecnología actual es una consecuencia directa de la física cuántica, es decir sin física cuántica no hubiese sido posible la construcción de un láser, computado...

¿Cómo servirse de la teoría lacaniana sin dejar de ser marxista?

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David Pavón-Cuéllar

2014-01-01

Full Text Available Se partirá de una situación hipotética definida por tres supuestos: alguien es marxista y quiere seguir siéndolo, pero no desea privarse de los recursos teóricos ofrecidos por el psicoanalista francés Jacques Lacan, aun si considera que el empleo de estos recursos puede llegar a ser más perjudicial que beneficioso para su marxismo. En estas condiciones, ¿qué hacer para obtener los beneficios y conjurar los perjuicios? Para empezar, ¿cómo asir a Lacan para no soltar a Marx? ¿Cómo hacer para mantenernos fieles a nuestro compromiso militante con el marxismo al atravesar el tentador escepticismo lacaniano? ¿Cómo evitar que el cuestionamiento psicoanalítico erosione y debilite nuestro posicionamiento crítico revolucionario? Y más allá de esto, ¿podemos conseguir lo contrario? ¿Es posible afilar y revigorizar nuestro marxismo con la fuerza del psicoanálisis lacaniano?

Paper based Flexible and Conformal SERS Substrate for Rapid Trace Detection on Real-world Surfaces

Science.gov (United States)

Singamaneni, Srikanth; Lee, Chang; Tian, Limei

2011-03-01

One of the important but often overlooked considerations in the design of surface enhanced Raman scattering (SERS) substrates for trace detection is the efficiency of sample collection. Conventional designs based on rigid substrates such as silicon, alumina, and glass resist conformal contact with the surface under investigation, making the sample collection inefficient. We demonstrate a novel SERS substrate based on common filter paper adsorbed with gold nanorods, which allows conformal contact with real-world surfaces, thus dramatically enhancing the sample collection efficiency compared to conventional rigid substrates. We demonstrate the detection of trace amounts of analyte (140 pg spread over 4 cm2) by simply swabbing the surface under investigation with the novel SERS substrate. The hierarchical fibrous structure of paper serves as a 3D vasculature for easy uptake and transport of the analytes to the electromagnetic hot spots in the paper. Simple yet highly efficient and cost effective SERS substrate demonstrated here brings SERS based trace detection closer to real-world applications. We acknowledge the financial support from Center for Materials Innovation at Washington University.

La ayuda oficial al desarrollo en el sector agrario

OpenAIRE

Areta García, Álvaro; Marín, Gonzalo

2006-01-01

El primer Objetivo de Desarrollo del Milenio habla de erradicar la pobreza extrema y el hambre. Por tanto, dado que la mayoría de la gente pobre vive en el medio rural o depende de la agricultura, y que en las naciones más pobres la agricultura prepara el terreno para el desarrollo económico, será imprescindible una gran inversión en el desarrollo rural y, por ende, en uno de sus “pilares” básicos, la agricultura. Sin embargo, el papel de la agricultura en el marco de la Ayuda Oficial al Desa...

Following the Dynamics of pH in Endosomes of Live Cells with SERS Nanosensors

DEFF Research Database (Denmark)

Kneipp, J.; Kneipp, Harald; Wittig, B.

2010-01-01

The surface enhanced Raman scattering (SERS) spectrum of a reporter molecule attached to gold or silver nanostructures, which is pH-sensitive, can deliver information on the local pH in the environment of the nanostructure. Here, we demonstrate the use of a mobile SERS nanosensor made from gold...... nanaoaggregates and 4-mercaptobenzoic acid (pMBA) attached as a reporter for monitoring changes in local pH of the cellular compartments of living NIH/3T3 cells. We show that SERS nanosensors enable the dynamics of local pH in individual live cells to be followed at subendosomal resolution in a timeline...

El Segundo Cerebro del ser humano.

OpenAIRE

Rocío Ponce

2015-01-01

Existen dos tipos de cerebros, el conocido por todos formado por el sistema nervioso central, que sería el cerebro donde las emociones se forman en base a las experiencias anteriores. El segundo cerebro, el otro, ignorado por la mayoría de seres humanos es el cerebro que está en los intestinos, Sistema Nervioso Enteral o mesentérico, que se caracteriza por la relación del cerebro y aparato digestivo, este cerebro posee más neuronas que su par, guarda emociones, determina la respuesta de acuer...

¿El Hombre del Siglo XXI será más Miope?

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Eduardo Arenas Archila

2002-08-01

Full Text Available

Se hace una revisión de lo que ha sido la evolución del sistema ocular en la especie humana desde las formas más primitivas de visión. Se observa que los ojos han venido sufriendo un proceso de maduración y excelencia, en gran parte ligado a las necesidades de cada especie. La percepción de colores y ondas electromagnéticas, por ejemplo, varía en ciertos animales según los propósitos alimenticios.

El tamaño del ojo parece ir ligado al desarrollo del cerebro. La miopía que consiste en la presencia de un ojo más alargado, ha venido incrementándose en el último siglo. Aparentemente hay una asociación muy fuerte entre la presencia de miopía y el grado de culturización e inteligencia. Los pueblos más desarrollados presentan mayor incidencia de miopía, y ésta a su vez se incrementa con la escolaridad. Basados en estudios filogenéticos y epidemiológicos se esboza la hipótesis: «que el hombre del futuro será cada vez más miope y a su vez más inteligente».

EVOLUCIÓN DEL SISTEMA OCULAR.

El primer ser multicelular con «ojos» rudimentarios aparece en la mitad de la era proterozoica, es decir, hace 1500 millones de años y sólo hasta el mesozoico, hace apenas 248 millones de años, se desarrollan los primeros animales con cerebro y ojos**. En los últimos 40 millones emergen los primates predecesores de los humanoides

Al igual que para muchas especies animales, a lo largo de la historia de la evolución, la exposición a la luz marcó un cambio dramático en el ciclo vital. El hombre salió de las cavernas, para acostumbrarse a la luz: sin luz no hay visión. La tierra ha sido bombardeada por ondas electromagnéticas desde su creación.

La luz, entre otros fenómenos, es la responsable de uno de las manifestaciones más primitivas de vida y se traduce en las escalas inferiores como un simple fototropismo. El anterior mecanismo da origen a los primeros esbozos

MARCADO CON LÁSER SOBRE CERÁMICA VIDRIADA POR APORTE SUPERFICIAL DE UN PIGMENTO DE COBALTO

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Maryory Astrid Gómez

2008-07-01

Full Text Available El procesamiento de materiales por láser tiene gran aplicación a escala industrial, para imprimir patrones gráficos sobre superficies cerámicas. La rápida implementación de este proceso se debe a que, respecto al proceso convencional de horneado, tiene ventajas tales como: se concentra el calor sólo en la zona irradiada, lo que conlleva un menor consumo de energía sin afectar significativamente el resto de la pieza; se obtienen patrones gráficos de alta resolución espacial; permite introducir cambios durante el proceso sin requerir largas paradas, y la generación de residuos es mínima o casi nula. En este estudio se presentan los resultados obtenidos en el vidriado con láser Nd:YAG (λ&=1064 nm sobre las superficies esmaltadas de azulejos, las cuales fueron previamente recubiertas con pigmento negro de cobalto. Con el láser operando en modo continuo (CW, se marcaron una serie de líneas, cuyo ancho y profundidad evidenciaron una dependencia directa con la variación de la potencia y velocidad de desplazamiento del haz láser sobre la superficie del azulejo. Estas líneas vidriadas fueron finalmente caracterizadas por microscopía óptica, espectroscopia de dispersión de energía (EDS y difracción de rayos X.Laser materials processing has great application to industrial scale, to print graphic patterns on ceramics surfaces. The fast implementation of this process is due to the fact that, with respect to the conventional baking process, has advantages, such as: heat is concentrated only in the radiated zone that involves a smaller energy consumption without affecting significantly the rest of the piece, graphic patterns with of highly spatial resolution are obtained, it permits to introduce changes during the process without requiring long stops, and low or almost none generation of residues. In this study the results obtained from Nd:YAG (λ=1064 nm laser glazing on the enameled surfaces of glazed tiles, which were previously

APRENDENDO A SER AFETADO: CONTRIBUIÇÕES PARA A EDUCAÇÃO EM CIÊNCIAS NA EDUCAÇÃO INFANTIL

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Francisco Ângelo Coutinho

Full Text Available RESUMO: O vínculo entre educação científica e educação infantil tem se constituído de modo tímido. Isso porque, muitas vezes, pensa-se equivocadamente que a maneira como a criança pequena interroga e investiga o mundo à sua volta não é apropriada. No entanto, fazendo uso da teoria ator-rede e de sua concepção de aprendizagem, analisamos episódio no qual crianças de 4 e 5 anos estavam engajadas na exploração de pistas deixadas em um jardim de uma Unidade Municipal de Educação Infantil. Nossos achados indicam que as crianças participam ativamente de atividades investigativas e aprendem a ser afetadas pelos elementos constitutivos do espaço designado para a exploração. Além disso, as crianças foram capazes de transformar os objetos tecnológicos disponibilizados em instrumentos científicos. Nossa análise foi possível por romper com uma concepção de aprendizagem como apropriação conceitual. Nesse sentido, procuramos entender a aprendizagem como capacidade de ser afetado e, portanto, como construção de um corpo.

SERS and fluorescence-based ultrasensitive detection of mercury in water.

Science.gov (United States)

Makam, Pandeeswar; Shilpa, Rohilla; Kandjani, Ahmad Esmaielzadeh; Periasamy, Selvakannan R; Sabri, Ylias Mohammad; Madhu, Chilakapati; Bhargava, Suresh Kumar; Govindaraju, Thimmaiah

2018-02-15

The development of reliable and ultrasensitive detection marker for mercury ions (Hg 2+ ) in drinking water is of great interest for toxicology assessment, environmental protection and human health. Although many Hg 2+ detection methods have been developed, only few offer sensitivities below 1pM. Herein, we describe a simple histidine (H) conjugated perylene diimide (PDI) bolaamphiphile (HPH) as a dual-responsive optical marker to develop highly selective and sensitive probe as visible (sol-to-gel transformation), fluorescence and SERS-based Hg 2+ sensor platform in the water. Remarkably, HPH as a SERS marker supported on Au deposited monodispersed nanospheres monolayers (Au-MNM) of polystyrene offers an unprecedented selectivity and the best ever reported detection limit (LOD) of 60 attomolar (aM, 0.01 parts-per-quadrillion (ppq)) for Hg 2+ in water. This is ten orders of magnitude lower than the United States Environmental Protection Agency (USEPA) tolerance limit of Hg 2+ in drinking water (10nM, 2 ppb). This simple and effective design principle of host-guest interactions driven fluorescence and SERS-based detection may inspire the future molecular engineering strategies for the development of ultrasensitive toxic analyte sensor platforms. Copyright © 2017 Elsevier B.V. All rights reserved.

A Sensitive Gold Nanoplasmonic SERS Quantitative Analysis Method for Sulfate in Serum Using Fullerene as Catalyst

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Chongning Li

2018-04-01

Full Text Available Fullerene exhibited strong catalysis of the redox reaction between HAuCl4 and trisodium citrate to form gold nanoplasmon with a strong surface-enhanced Raman scattering (SERS effect at 1615 cm−1 in the presence of Vitoria blue B molecule probes. When fullerene increased, the SERS peak enhanced linearly due to formation of more AuNPs as substrate. Upon addition of Ba2+, Ba2+ ions adsorb on the fullerene surface to inhibit the catalysis of fullerene that caused the SERS peak decreasing. Analyte SO42− combined with Ba2+ to form stable BaSO4 precipitate to release free fullerene that the catalysis recovered, and the SERS intensity increased linearly. Thus, a new SERS quantitative analysis method was established for the detection of sulfate in serum samples, with a linear range of 0.03–3.4 μM.

Nonequilibrium Chemical Effects in Single-Molecule SERS Revealed by Ab Initio Molecular Dynamics Simulations

Energy Technology Data Exchange (ETDEWEB)

Fischer, Sean A.; Apra, Edoardo; Govind, Niranjan; Hess, Wayne P.; El-Khoury, Patrick Z.

2017-02-03

Recent developments in nanophotonics have paved the way for achieving significant advances in the realm of single molecule chemical detection, imaging, and dynamics. In particular, surface-enhanced Raman scattering (SERS) is a powerful analytical technique that is now routinely used to identify the chemical identity of single molecules. Understanding how nanoscale physical and chemical processes affect single molecule SERS spectra and selection rules is a challenging task, and is still actively debated. Herein, we explore underappreciated chemical phenomena in ultrasensitive SERS. We observe a fluctuating excited electronic state manifold, governed by the conformational dynamics of a molecule (4,4’-dimercaptostilbene, DMS) interacting with a metallic cluster (Ag20). This affects our simulated single molecule SERS spectra; the time trajectories of a molecule interacting with its unique local environment dictates the relative intensities of the observable Raman-active vibrational states. Ab initio molecular dynamics of a model Ag20-DMS system are used to illustrate both concepts in light of recent experimental results.

Grosor corneal central y conteo de células endoteliales en pacientes sometidos a cirugía de catarata asistida con láser de femtosegundos comparada con cirugía facoemulsificación tradicional

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Georgina Givaudan Pedroza

2016-09-01

Conclusiones: Aunque se observó una diferencia estadísticamente significativa en cuanto al tiempo efectivo de faco, siendo menor en el grupo de femtosegundos, no se encontraron diferencias estadísticamente significativas en el CCE y grosor corneal central entre el grupo de facoemulsificación convencional y el asistido por láser de femtosegundos.

Ser educador(a é ... (também socializar inquietações

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Sandra Marisa Allebrandt-Padilha

2011-11-01

Full Text Available O presente artigo convida os educadores a refletir sobre questões candentes do cotidiano escolar, tais como: o sofrimento diante do aluno que não aprende, o mal-estar-docente decorrente das transformações sociopolíticas que convergem para a Educação Inclusiva. Nessa perspectiva, com o propósito de buscar respostas para a Educação na Diversidade, elegemos algumas iniciativas que desafiam aqueles que desejam ser protagonistas no ofício SER EDUCADOR.Palavras-chave: Cotidiano Escolar. Dificuldade de Aprendizagem. Educação Inclusiva, Mal-Estar-Docente. Diversidade..

Fabrication of SERS Active Surface on Polyimide Sample by Excimer Laser Irradiation

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T. Csizmadia

2014-01-01

Full Text Available A possible application of excimer laser irradiation for the preparation of surface enhanced Raman spectroscopy (SERS substrate is demonstrated. A polyimide foil of 125 μm thickness was irradiated by 240 pulses of focused ArF excimer laser beam (λ = 193 nm, FWHM = 20 ns. The applied fluence was varied between 40 and 80 mJ/cm2. After laser processing, the sample was coated with 40 nm silver by PLD in order to create a conducting layer required for the SERS application. The SERS activity of the samples was tested by Raman microscopy. The Raman spectra of Rhodamine 6G aqueous solution (c=10−3 mol/dm3 were collected from the patterned and metalized areas. For areas prepared at 40–60 mJ/cm2 laser fluences, the measured Raman intensities have shown a linear dependence on the applied laser fluence, while above 60 mJ/cm2 saturation was observed. The morphology of the SERS active surface areas was investigated by scanning electron microscopy. Finite element modeling was performed in order to simulate the laser-absorption induced heating of the polyimide foil. The simulation resulted in the temporal and spatial distribution of the estimated temperature in the irradiated polyimide sample, which are important for understanding the structure formation process.

Análisis de plasmas inducidos por láser con excitación multipulso para el proceso de ablación de areolas de Tuna

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Teresa Flores

2010-01-01

Full Text Available Introducción: La técnica de análisis de plasmas inducidos por láser (LIBS, posee importantes ventajas como son que la muestra no requiere preparación previa, puede estar en fase sólida, liquida o gaseosa y tener cualquier forma y dimensión, se requiere una cantidad mínima de material y, finalmente, el análisis se realiza en tiempo real. Estas ventajas, hacen posible el seguimiento en tiempo real de un proceso de ablación láser, incluso para muestras de composición compleja. Para el monitoreo de un proceso industrial, esta herramienta sería más adecuada, si se cuenta con una calibración del equipo y un protocolo particular definido. En el trabajo, se ejemplifica esta posibilidad para el caso de la ablación láser de areolas de Tuna (fruto de el Opuntia ficus-indica. Método: Se realiza el análisis LIBS de muestras de tuna, tanto en las areolas como en la corteza. Para la excitación del plasma se emplea un láser de Nd:YAG en régimen de Q:Switch con tren de pulsos. Con el objeto de asegurar el reconocimiento de las líneas en los espectros LIBS, se realizaron análisis en patrones de composición conocida, estableciéndose un protocolo para la interpretación de los espectros. Resultados: Se logró una clara lectura de la línea de H ubicada en 656.2 nm. Se estableció un protocolo para la interpretación de los espectros, que permitió la identificación de 49 picos característicos. Finalmente, se determina la composición para la corteza y la areola y se lleva a cabo una comparación cualitativa entre éstas. Discusión: Se muestra que la excitación láser en forma de tren de pulsos, entendido este régimen como modalidad particular del Q:Switch, permite la determinación eficiente de elementos, con una adecuada relación señal-ruido. Por otra parte, que es posible determinar diferencias composicionales evidentes entre corteza y la areola, lo cual permite monitorear un proceso de ablación de areolas con láser de manera

Morbidade e mortalidade associadas ao fechamento de colostomias e ileostomias em alça acessadas pelo estoma intestinal

OpenAIRE

Oliveira,Ricardo Augusto Nahuz de; Oliveira,Paulo Gonçalves de; Santos,Antônio Carlos Nobrega dos; Sousa,João Batista de

2012-01-01

OBJETIVO: Avaliar a morbimortalidade de operações realizadas para fechamento de colostomias e ileostomias em alça. MÉTODOS: Foram analisados os dados epidemiológicos, complicações pós-operatórias, morbidade e mortalidade de pacientes que se submeteram à operações para fechamento de colostomias e ileostomias em alça. Foram excluídos os pacientes cujos dados não puderam ser obtidos nos prontuários e os que operações para fechamento requereram laparotomia mediana. RESULTADOS: Foram operados 88 p...

SERS internship fall 1995 abstracts and research papers

Energy Technology Data Exchange (ETDEWEB)

Davis, Beverly

1996-05-01

This report is a compilation of twenty abstracts and their corresponding full papers of research projects done under the US Department of Energy Science and Engineering Research Semester (SERS) program. Papers cover a broad range of topics, for example, environmental transport, supercomputers, databases, biology. Selected papers were indexed separately for inclusion the the Energy Science and Technology Database.

Die Inhibition der Casein Kinase 2 durch DMAT als Therapieoption bei Pankreaskarzinom

OpenAIRE

Plötz, Katharina

2011-01-01

1.1.1 Hintergrund Das Pankreaskarzinom stellt mit einer Inzidenz von etwa 9-10 neuen Fällen pro Jahr eine nicht zu vernachlässigende Krebserkrankung der Zivilbevölkerung dar. Unter den verschiedenen Formen tritt das duktale Adenokarzinom am häufigsten auf. Als Auslöser werden heute sehr viele unterschiedliche Ursachen diskutiert. So schreibt man dem Rauchen beispielsweise nahezu 30 % aller Fälle des Pankreaskarzinoms zu. Genauso aber erhöhen bestimmte genetische Faktoren das Risiko, an Bauchs...

Factores asociados a la no adherencia al tratamiento anti tuberculosis

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Laura Inés Plata-Casas

2015-12-01

Full Text Available Objetivo: describir los factores de riesgo asociados a la no adherencia al tratamiento en los pacientes adscritos al programa de tuberculosis en el Municipio de Villavicencio, cohorte 2012. Materiales y Métodos: se ha realizado un estudio descriptivo de corte transversal con enfoque cuantitativo. Se obtuvieron datos de caracterización sociodemográfica sobre factores de riesgo de personas que abandonaron el tratamiento para la enfermedad- cohorte 2012- mediante la aplicación de un instrumento diseñado por el investigador y revisado por expertos. Los datos fueron tabulados y analizados mediante la herramienta Microsoft Excel® 2007 y Epi-info 7.0. Resultados: el 75% de los pacientes pertenecen al género masculino; el promedio de edad es de 30 años, el 63% pertenecen al régimen subsidiado de salud. Las principales causas de abandono fueron: efectos adversos a los medicamentos (58%, inadecuada atención del personal de salud (43%, dificultad de acceso al servicio (32%. Los factores sociales encontrados fueron hacinamiento 67% y desempleo 62%. Conclusiones: algunos factores no modificables como la edad y el género, así como factores modificables como estilos de vida inadecuados y efectos adversos; cuyo control mejoraría el cumplimiento; contribuyen al abandono del tratamiento. Las variables psicológicas y sociales deben ser evaluadas para que se conviertan en predictores de probables abandonos o irregularidades en el tratamiento antituberculoso.

El modo de ser cínico de los dirigentes The Way of Being Cynical of the Leaders

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Álvaro Zapata Domínguez

2009-06-01

Full Text Available Bédard (1995, 2002, ha identificado tres modos de ser que ella designa como “Modo de Ser mítico”, “Modo de Ser sistemático”, “Modo de Ser pragmático”, un cuarto modo de Ser, el “Modo de Ser relacional” ha sido propuesto por Alain Chanlat (1995. Estos modos de Ser, son para los autores, la manifestación de las grandes tendencias del pensamiento occidental. En este contexto en el presente artículo se desarrolla el “Modo de Ser Cínico” de los dirigentes. Los valores fundamentales que distinguen el cinismo, son: la resistencia, la impasibilidad, la maldad.Bédard (1995, 2002, has identified three manners of being, that she designates as the “Way of being mythical”, the “Way of being systematic”, and the “Way of being pragmatic”. A fourth way of being, the “Way of being relational” has been proposed by Alain Chanlat (1995. These ways of being, are for the authors, the manifestation of big trends in Western thought. In this context, in the present article, the “Way of being cynical” of the leaders is developed. The fundamental values that distinguish the cynicism are: resistance, impassivity and evil.

Preparation of sensitive and recyclable porous Ag/TiO{sub 2} composite films for SERS detection

Energy Technology Data Exchange (ETDEWEB)

Zhang, Zhengyi; Yu, Jiajie; Yang, Jingying; Lv, Xiang; Wang, Tianhe, E-mail: thwang56@126.com

2015-12-30

Graphical abstract: - Highlights: • A new but simple method of fabricating robust TiO{sub 2} films on glass. • AgNPs were deposited on the surface of TiO{sub 2} films with the assistance of UV irradiation. • Substrates with high SERS sensitivity and excellent recyclability. - Abstract: Porous Ag/TiO{sub 2} composite films were prepared by spin coating of titania on normal glass slides and subsequent photochemical deposition of silver nanoparticles (AgNPs). The films were characterized by XRD and FESEM to reveal micro structural and morphological differences between films obtained under varied conditions. The SERS properties of these films were investigated using aqueous crystal violet (CV) as probe molecules. The results indicate that the content of polyethylene glycol (PEG) and photo-reduction time had significant influences on both the microstructure and SERS performance of Ag/TiO{sub 2} films. The highest SERS sensitivity that allowed as low as 10{sup −10} M aqueous CV to be detected, was achieved with the PEG/(C{sub 4}H{sub 9}O){sub 4}Ti molar ratio being 0.08% and with 30 min of UV irradiation. With this film a linear relationship was established through experiment between SERS intensity and CV concentration from 10{sup −10} to 10{sup −5} M, which could be used as a calibration curve for CV concentration measurement. In addition, the film could be reused as a SERS substrate for up to four times without significantly losing SERS sensitivity if a simple regeneration was followed. It is visualized that the Ag/TiO{sub 2} film on glass has potentials for being developed into a practical SERS substrate with high sensitivity and good reusability.

Amnesic shellfish poisoning biotoxin detection in seawater using pure or amino-functionalized Ag nanoparticles and SERS.

Science.gov (United States)

Müller, Csilla; Glamuzina, Branko; Pozniak, Iva; Weber, Karina; Cialla, Dana; Popp, Jürgen; Cîntă Pînzaru, Simona

2014-12-01

Domoic acid (DA) biotoxin responsible for the amnesic shellfish poisoning (ASP) has been unambiguously detected in seawater in a broad range of concentration, with both pure and amino-functionalized Ag nanoparticles employed for surface enhanced Raman scattering (SERS). To achieve this, a comprehensive SERS study on DA dissolved in distilled water has been conducted. SERS of DA dissolved in seawater in concentrations ranging from 3.3 × 10(-4) to 3.3 × 10(-8) mol l(-1) exhibited specific signal, completely different to those of the corresponding DA aqueous solutions, due to the seawater interference in the overall SERS effect. In order to assess the capability of the technique as a cheaper alternative for rapid and unambiguous detection of the DA biotoxin in seawater, three detection schemes have been proposed. DA was detectable at 0.33 nmoll(-1) concentration (0.33) dissolved in distilled water and 0.033 nmol l(-1) (0.033 ppb) in seawater respectively, much lower than the admitted level by the current regulation. A solvent specific interaction of DA with the NPs was concluded, since DA aqueous solution added to Ag nanoparticles provided different SERS signal compared to that of DA directly dissolved in seawater. Employing amino-functionalized Ag nanoparticles with 4-aminothiophenol as SERS tag, SERS signal of DA on amino-AgNPs revealed significant specificity associated with the aromatic primary amine interaction of the SERS tag with DA, thus allowing DA detection in seawater at 4.16 × 10(-4) mol l(-1) concentration, much higher than in the case of pure NPs. To highlight the findings, a brief literature review to date on the DA biotoxin detection was also provided. Copyright © 2014 Elsevier B.V. All rights reserved.

Modelo numérico tridimensional para la simulación de procesos de tratamiento superficial de materiales con láser

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García-Beltrán, A.

1999-04-01

Full Text Available A numerical model for the predictive assessment of laser transformation hardening of steels and other surface treatments both in metallic and non-metallic materials has been developed. Starting from material and geometry data, the problem of heat diffusion from the thermal source provided by the laser is solved with complete space and temperature-dependence. The developed 3D simulation model has been successfully checked against theoretical and experimental results both for metallic and non-metallic materials. Typical examples of its application have been the thermal surface hardening of steels and the analysis of thermal fields in low diffusivity materials (as optical glass in laser polishing applications.

Se desarrolla un modelo numérico para la predicción y análisis del temple superficial de aceros por láser y de otros tratamientos superficiales de materiales metálicos y no metálicos. Partiendo de los datos del material y de su geometría, el modelo tridimensional de simulación desarrollado resuelve el problema de la transferencia de calor de la fuente generada por el haz láser dependiente del tiempo y de la temperatura y ha sido contrastado teórica y experimentalmente tanto para materiales metálicos como no metálicos. Ejemplos típicos de su aplicación son el temple superficial de acero al carbono y el análisis de los campos térmicos en materiales de baja conductividad térmica (como el vidrio óptico en aplicaciones de pulido con láser.

Colorimetry and SERS dual-mode detection of telomerase activity: combining rapid screening with high sensitivity.

Science.gov (United States)

Zong, Shenfei; Wang, Zhuyuan; Chen, Hui; Hu, Guohua; Liu, Min; Chen, Peng; Cui, Yiping

2014-01-01

As an important biomarker and therapeutic target, telomerase has attracted considerable attention concerning its detection and monitoring. Here, we present a colorimetry and surface enhanced Raman scattering (SERS) dual-mode telomerase activity detection method, which has several distinctive advantages. First, colorimetric functionality allows rapid preliminary discrimination of telomerase activity by the naked eye. Second, the employment of SERS technique results in greatly improved detection sensitivity. Third, the combination of colorimetry and SERS into one detection system can ensure highly efficacious and sensitive screening of numerous samples. Besides, the avoidance of polymerase chain reaction (PCR) procedures further guarantees fine reliability and simplicity. Generally, the presented method is realized by an "elongate and capture" procedure. To be specific, gold nanoparticles modified with Raman molecules and telomeric repeat complementary oligonucleotide are employed as the colorimetric-SERS bifunctional reporting nanotag, while magnetic nanoparticles functionalized with telomerase substrate oligonucleotide are used as the capturing substrate. Telomerase can synthesize and elongate telomeric repeats onto the capturing substrate. The elongated telomeric repeats subsequently facilitate capturing of the reporting nanotag via hybridization between telomeric repeat and its complementary strand. The captured nanotags can cause a significant difference in the color and SERS intensity of the magnetically separated sediments. Thus both the color and SERS can be used as indicators of the telomerase activity. With fast screening ability and outstanding sensitivity, we anticipate that this method would greatly promote practical application of telomerase-based early-stage cancer diagnosis.

P-Ser-HPr-a link between carbon metabolism and the virulence of some pathogenic bacteria

DEFF Research Database (Denmark)

Mijakovic, Ivan

2005-01-01

HPr kinase/phosphorylase phosphorylates HPr, a phosphocarrier protein of the phosphoenolpyruvate:carbohydrate phosphotransferase system, at serine-46. P-Ser-HPr is the central regulator of carbon metabolism in Gram-positive bacteria, but also plays a role in virulence development of certain...... pathogens. In Listeria monocytogenes, several virulence genes, which depend on the transcription activator PrfA, are repressed by glucose, fructose, etc., in a catabolite repressor (CcpA)-independent mechanism. However, the catabolite co-repressor P-Ser-HPr was found to inhibit the activity of Prf...... is preceded by an operator site, which serves as target for the CcpA/P-Ser-HPr complex. Numerous Gram-negative pathogens also contain hprK, which is often organised in an operon with transcription regulators necessary for the development of virulence, indicating that in these organisms P-Ser-HPr also plays...

for SERS and Photocatalytic Applications

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Xue Chen

2011-01-01

Full Text Available ZnS/Si nanocables were synthesized via a simple two-step thermal evaporation method. The shape and diameter of the ZnS/Si nanocables can be controlled by adjusting the morphologies of the ZnS nanostructures (nanowire or nanoribbon obtained in the first step and the deposition time of the Si shell in the second step, respectively. Furthermore, we obtained polycrystalline Si nanotubes with different shapes and diameters by etching away the inner ZnS core. The as-prepared Si nanotubes were employed as SERS-active substrates, which exhibited a high sensitivity for the detection of R6G. The Si nanotubes also showed effective photocatalytic activity on the decomposition of R6G under the irradiation of visible light.

Enhanced Self-Organized Dewetting of Ultrathin Polymer Blend Film for Large-Area Fabrication of SERS Substrate.

Science.gov (United States)

Zhang, Huanhuan; Xu, Lin; Xu, Yabo; Huang, Gang; Zhao, Xueyu; Lai, Yuqing; Shi, Tongfei

2016-12-06

We study the enhanced dewetting of ultrathin Polystyrene (PS)/Poly (methyl methacrylate) (PMMA) blend films in a mixed solution, and reveal the dewetting can act as a simple and effective method to fabricate large-area surface-enhanced Raman scattering (SERS) substrate. A bilayer structure consisting of under PMMA layer and upper PS layer forms due to vertical phase separation of immiscible PS/PMMA during the spin-coating process. The thicker layer of the bilayer structure dominates the dewetting structures of PS/PMMA blend films. The diameter and diameter distribution of droplets, and the average separation spacing between the droplets can be precisely controlled via the change of blend ratio and film thickness. The dewetting structure of 8 nm PS/PMMA (1:1 wt%) blend film is proved to successfully fabricate large-area (3.5 cm × 3.5 cm) universal SERS substrate via deposited a silver layer on the dewetting structure. The SERS substrate shows good SERS-signal reproducibility (RSD dewetting of polymer blend films broadens the application of dewetting of polymer films, especially in the nanotechnology, and may open a new approach for the fabrication of large-area SERS substrate to promote the application of SERS substrate in the rapid sensitive detection of trace molecules.

Facile fabrication of Ag dendrite-integrated anodic aluminum oxide membrane as effective three-dimensional SERS substrate

Science.gov (United States)

Zhang, Cong-yun; Lu, Ya; Zhao, Bin; Hao, Yao-wu; Liu, Ya-qing

2016-07-01

A novel surface enhanced Raman scattering (SERS)-active substrate has been successfully developed, where Ag-dendrites are assembled on the surface and embedded in the channels of anodic aluminum oxide (AAO) membrane, via electrodeposition in AgNO3/PVP aqueous system. Reaction conditions were systematically investigated to attain the best Raman enhancement. The growth mechanism of Ag dendritic nanostructures has been proposed. The Ag dendrite-integrated AAO membrane with unique hierarchical structures exhibits high SERS activity for detecting rhodamine 6G with a detection limit as low as 1 × 10-11 M. Furthermore, the three-dimensional (3D) substrates display a good reproducibility with the average intensity variations at the major Raman peak less than 12%. Most importantly, the 3D SERS substrates without any surface modification show an outstanding SERS response for the molecules with weak affinity for noble metal surfaces. The potential application for the detection of polycyclic aromatic hydrocarbons (PAHs) was evaluated with fluoranthene as Raman target molecule and a sensitive SERS detection with a limit down to 10-8 M was reached. The 3D SERS-active substrate shows promising potential for rapid detection of trace organic pollutants even weak affinity molecules in the environment.

Aprendendo a ser psicoterapeuta

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Elizabeth Amelio Faleiros

Full Text Available Este estudo investiga, na perspectiva de Jacob Levy Moreno, a concepção que alunos de Psicologia têm sobre o que é ser psicoterapeuta, quais elementos são necessários para o desenvolvimento dessa tarefa e os fatores impeditivos para realizá-la. Propõe formas de soluções para o desempenho daquela função, favorecendo a reflexão sobre a importância dessa tarefa e a responsabilidade do profissional junto ao paciente. A metodologia utilizada é a qualitativa, pois esta permite abordar dimensões da subjetividade dos sujeitos. Os resultados revelam que os alunos possuem em sua concepção os alicerces básicos, cujos indicadores são apontados por Moreno e por outros autores, percebem os requisitos básicos que constituem a essência do papel de terapeuta, evidenciam críticas realistas sobre os fatores limitadores e sugerem ações pedagógicas para minimizá-los.

The application of Silver nanoparticle based SERS in diagnosing thyroid tissue

Energy Technology Data Exchange (ETDEWEB)

Huang Zufang; Chen Rong; Chen Guannan; Lin Duo; Xi Gangqin; Chen Yongjian; Lin Hongxin; Lei Jinping [Key Laboratory of Optoelectronic Science and Technology for Medicine, Ministry of Education, Fujian Normal University, Fuzhou 350007 (China); Li Zuanfang, E-mail: chenr@fjnu.edu.cn [Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou 350108 (China)

2011-01-01

Surface-enhanced Raman scattering (SERS) is proved to be a powerful analytical tool for investigation of biological tissue. In this study, SERS based on Ag nanoparticles was used to investigate the normal and cancerous thyroid tissue. Preliminary results indicated that Raman peaks and the spectra profile from both normal and cancerous tissues showed a basic similarity, obvious differences are that, first, Raman peaks 563cm{sup -1}, 1449cm{sup -1} and 1587cm{sup -1} in cancerous tissue decreased obviously compared with the normal thyroid tissue. Besides, Raman peaks 1004cm{sup -1} and 1128cm{sup -1} might be specific peaks for normal thyroid tissue, whereas 1294cm{sup -1} might attribute to specific peak for cancerous thyroid tissue. In addition, some peaks in normal thyroid tissue appeared to have shifted in cancerous tissue. Intensity ratio of 656cm{sup -1} vs. 725cm{sup -1} in normal tissue are significantly different from cancerous tissue (P<0.005), and it can be a reference for spectroscopic diagnostics of thyroid tissue. This study demonstrates that SERS can be used to monitor the changes at molecular level as well as a complementary tool in thyroid histopathology.

Sodium Chloride Crystal-Induced SERS Platform for Controlled Highly Sensitive Detection of Illicit Drugs.

Science.gov (United States)

Yu, Borong; Li, Pan; Zhou, Binbin; Tang, Xianghu; Li, Shaofei; Yang, Liangbao

2018-04-03

A sodium chloride crystal-driven spontaneous 'hot spot' structure was demonstrated as a SERS-active platform, to get reproducible SERS signals, and eliminate the need for mapping large areas, in comparison with solution phase testing. During the process of solvent evaporation, the crystals produced induced silver aggregates to assemble around themselves. The micro-scale crystals can also act as a template to obtain an optical position, such that the assembled hot area is conveniently located during SERS measurements. More importantly, the chloride ions added in colloids can also replace the citrate and on the surface of the silver sol, and further decrease the background interference. High quality SERS spectra from heroin, methamphetamine (MAMP), and cocaine have been obtained on the crystal-driven hot spot structure with high sensitivity and credible reproducibility. This approach can not only bring the nanoparticles to form plasmonic hot spots in a controlled way, and thus provide high sensitivity, but also potentially be explored as an active substrate for label-free detection of other illicit drugs or additives. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Progress in the Development of SERS-Active Substrates Based on Metal-Coated Porous Silicon.

Science.gov (United States)

Bandarenka, Hanna V; Girel, Kseniya V; Zavatski, Sergey A; Panarin, Andrei; Terekhov, Sergei N

2018-05-21

The present work gives an overview of the developments in surface-enhanced Raman scattering (SERS) with metal-coated porous silicon used as an active substrate. We focused this review on the research referenced to SERS-active materials based on porous silicon, beginning from the patent application in 2002 and enclosing the studies of this year. Porous silicon and metal deposition technologies are discussed. Since the earliest studies, a number of fundamentally different plasmonic nanostructures including metallic dendrites, quasi-ordered arrays of metallic nanoparticles (NPs), and metallic nanovoids have been grown on porous silicon, defined by the morphology of this host material. SERS-active substrates based on porous silicon have been found to combine a high and well-reproducible signal level, storage stability, cost-effective technology and handy use. They make it possible to identify and study many compounds including biomolecules with a detection limit varying from milli- to femtomolar concentrations. The progress reviewed here demonstrates the great prospects for the extensive use of the metal-coated porous silicon for bioanalysis by SERS-spectroscopy.

Progress in the Development of SERS-Active Substrates Based on Metal-Coated Porous Silicon

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Hanna V. Bandarenka

2018-05-01

Full Text Available The present work gives an overview of the developments in surface-enhanced Raman scattering (SERS with metal-coated porous silicon used as an active substrate. We focused this review on the research referenced to SERS-active materials based on porous silicon, beginning from the patent application in 2002 and enclosing the studies of this year. Porous silicon and metal deposition technologies are discussed. Since the earliest studies, a number of fundamentally different plasmonic nanostructures including metallic dendrites, quasi-ordered arrays of metallic nanoparticles (NPs, and metallic nanovoids have been grown on porous silicon, defined by the morphology of this host material. SERS-active substrates based on porous silicon have been found to combine a high and well-reproducible signal level, storage stability, cost-effective technology and handy use. They make it possible to identify and study many compounds including biomolecules with a detection limit varying from milli- to femtomolar concentrations. The progress reviewed here demonstrates the great prospects for the extensive use of the metal-coated porous silicon for bioanalysis by SERS-spectroscopy.

O ser humano da sociedade capitalista na concepção de Erich Fromm

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Edmilson Ferreira Marques

2010-07-01

Full Text Available

A proposta deste texto é buscar na psicanálise pensada e desenvolvida por Erich Fromm elementos para se pensar o ser humano da sociedade capitalista. Erich Fromm, dentre a maioria dos psicanalistas existentes, desde Freud, procurou desenvolver suas pesquisas e reflexões a partir da “psicanálise humanista”, oferecendo, assim, recursos heurísticos fundamentais para se pensar a vida na sociedade. Nesse sentido, propomos analisar primeiramente o seu método de análise, a partir do qual acreditamos ser fundamental para compreender o procedimento teórico/metodológico que utilizava para pensar os temas por ele abordados, e, nesse sentido, encontrar o caminho a ser percorrido na busca em seu pensamento da seguinte questão: como abordar a partir de seu ponto de vista, o ser humano da sociedade capitalista? Enfim, propomos uma avaliação da própria teoria de Fromm, apontando suas principais contribuições.

Cuándo deberían los utilitaristas ser teóricos de la virtud

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Jamieson, Dale

2005-06-01

Full Text Available The contrast typically between utilitarianism and virtue theory is overdrawn. Utilitarianism in a universal emulator: it implies that we should lie, cheat, steal, even appropriate Aristotle, when that is what brings about the best outcomes. In some cases and in some worlds it is best for us to be concerned with character traits. Global environmental change leads to concerns about character because the best results will be produced by generally uncoupling my behaviour from that of others. Thus, in this case an in this case an in this world, utilitarians should be virtue theorist.

El contraste que habitualmente se establece entre el Utilitarismo y la teoría de la virtud queda en entredicho en este ensayo. El Utilitarismo puede encamar cualquier conducta, ya que implica que deberíamos mentir, engañar, robar y aun apropiamos de Aristóteles, si con ello vamos a ocasionar los mejores resultados. En algunas situaciones y en algunos mundos posibles, lo mejor se obtendría centrándonos en los rasgos de carácter. El Cambio Medioambiental Global nos lleva al estudio de los caracteres, puesto que en este caso los mejores resultados se obtienen, generalmente, al disociar nuestro comportamiento del de los demás. Por ello, en este caso y en este mundo, los utilitaristas deberían ser teóricos de la virtud.

Acerca de la doctrina de la indestructibilidad de nuestro verdadero ser por la muerte

OpenAIRE

Schopenhauer, Arthur

2010-01-01

"Acerca de la doctrina de la indestructibilidad de nuestro verdadero ser por la muerte" es un escrito complementario del famoso capítulo 41 del Tomo II de El mundo como voluntad y representación, que lleva el paradójico título: "Sobre la muerte y su relación con la indestructibilidad de nuestro ser en sí" . El título es paradójico porque Schopenhauer habla de "nuestro ser en sí" y no parece fácilmente concebible la adscripción del posesivo"nuestro" a lo que"es en sí", o sea, a lo que existe i...

Metal Nanoparticles Deposited on Porous Silicon Templates as Novel Substrates for SERS

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Lara Mikac

2015-12-01

Full Text Available In this paper, results on preparation of stable and uniform SERS solid substrates using macroporous silicon (pSi with deposited silver and gold are presented. Macroporous silicon is produced by anodisation of p-type silicon in hydrofluoric acid. The as prepared pSi is then used as a template for Ag and Au depositions. The noble metals were deposited in three different ways: by immersion in silver nitrate solution, by drop-casting silver colloidal solution and by pulsed laser ablation (PLA. Substrates obtained by different deposition processes were evaluated for SERS efficiency using methylene blue (MB and rhodamine 6G (R6G at 514.5, 633 and 785 nm. Using 514.5 nm excitation and R6G the limits of detection (LOD for macroporous Si samples with noble metal nanostructures obtained by immersion of pSi sample in silver nitrate solution and by applying silver colloidal solution to pSi template were 10–9 M and 10–8 M respectively. Using 633 nm laser and MB the most noticeable SERS activity gave pSi samples ablated with 30000 and 45000 laser pulses where the LODs of 10–10 M were obtained. The detection limit of 10–10 M was also reached for 4 mA cm–2-15 min pSi sample, silver ablated with 30000 pulses. Macroporous silicon proved to be a good base for the preparation of SERS substrates.

Label-free direct surface-enhanced Raman scattering (SERS) of nucleic acids (Conference Presentation)

Science.gov (United States)

Guerrini, Luca; Morla-Folch, Judit; Gisbert-Quilis, Patricia; Xie, Hainan; Alvarez-Puebla, Ramon

2016-03-01

Recently, plasmonic-based biosensing has experienced an unprecedented level of attention, with a particular focus on the nucleic acid detection, offering efficient solutions to engineer simple, fast, highly sensitive sensing platforms while overcoming important limitations of PCR and microarray techniques. In the broad field of plasmonics, surface-enhanced Raman scattering (SERS) spectroscopy has arisen as a powerful analytical tool for detection and structural characterization of biomolecules. Today applications of SERS to nucleic acid analysis largely rely on indirect strategies, which have been demonstrated very effective for pure sensing purposes but completely dismiss the exquisite structural information provided by the direct acquisition of the biomolecular vibrational fingerprint. Contrarily, direct label-free SERS of nucleic acid shows an outstanding potential in terms of chemical-specific information which, however, remained largely unexpressed mainly because of the inherent poor spectral reproducibility and/or limited sensitivity. To address these limitations, we developed a fast and affordable high-throughput screening direct SERS method for gaining detailed genomic information on nucleic acids (DNA and RNA) and for the characterization and quantitative recognition of DNA interactions with exogenous agents. The simple strategy relies on the electrostatic adhesion of DNA/RNA onto positively-charged silver colloids that promotes the nanoparticle aggregation into stable clusters yielding intense and reproducible SERS spectra at picogram level (i.e. the analysis can be performed without the necessity of amplification steps thus providing realistic direct information of the nucleic acid in its native state). We anticipate this method to gain a vast impact and set of applications in different fields, including medical diagnostics, genomic screening, drug discovery, forensic science and even molecular electronics.

Selective epitaxial growth of monolithically integrated GaN-based light emitting diodes with AlGaN/GaN driving transistors

International Nuclear Information System (INIS)

Liu, Zhaojun; Ma, Jun; Huang, Tongde; Liu, Chao; May Lau, Kei

2014-01-01

In this Letter, we report selective epitaxial growth of monolithically integrated GaN-based light emitting diodes (LEDs) with AlGaN/GaN high-electron-mobility transistor (HEMT) drivers. A comparison of two integration schemes, selective epitaxial removal (SER), and selective epitaxial growth (SEG) was made. We found the SER resulted in serious degradation of the underlying LEDs in a HEMT-on-LED structure due to damage of the p-GaN surface. The problem was circumvented using the SEG that avoided plasma etching and minimized device degradation. The integrated HEMT-LEDs by SEG exhibited comparable characteristics as unintegrated devices and emitted modulated blue light by gate biasing

Derivatization reaction-based surface-enhanced Raman scattering (SERS) for detection of trace acetone.

Science.gov (United States)

Zheng, Ying; Chen, Zhuo; Zheng, Chengbin; Lee, Yong-Ill; Hou, Xiandeng; Wu, Li; Tian, Yunfei

2016-08-01

A facile method was developed for determination of trace volatile acetone by coupling a derivatization reaction to surface-enhanced Raman scattering (SERS). With iodide modified Ag nanoparticles (Ag IMNPs) as the SERS substrate, acetone without obvious Raman signal could be converted to SERS-sensitive species via a chemical derivatization reaction with 2,4-dinitrophenylhydrazine (2,4-DNPH). In addition, acetone can be effectively separated from liquid phase with a purge-sampling device and then any serious interference from sample matrices can be significantly reduced. The optimal conditions for the derivatization reaction and the SERS analysis were investigated in detail, and the selectivity and reproducibility of this method were also evaluated. Under the optimal conditions, the limit of detection (LOD) for acetone was 5mgL(-1) or 0.09mM (3σ). The relative standard deviation (RSD) for 80mgL(-1) acetone (n=9) was 1.7%. This method was successfully used for the determination of acetone in artificial urine and human urine samples with spiked recoveries ranging from 92% to 110%. The present method is convenient, sensitive, selective, reliable and suitable for analysis of trace acetone, and it could have a promising clinical application in early diabetes diagnosis. Copyright © 2016 Elsevier B.V. All rights reserved.

Evaluación clínico-citológica del herpes labial tratado con láser

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Teresa García Sánchez,

2001-08-01

Full Text Available Se realizó un estudio descriptivo, longitudinal y prospectivo consistente en la descripción citológica y clínica de las muestras obtenidas en 150 pacientes con herpes labial diagnosticadas y atendidas en las diferentes consultas, que reunieron criterios de inclusión objetivos y subjetivos. Las muestras obtenidas por raspado de la superficie afectada se fijaron con cytospray y se colorearon con el método de Papanicolau; fueron leídas al inicio y a las 48 horas para evaluar la recuperación de la mucosa bajo los efectos del láser infrarrojo de arsenurio de galio y aluminio en dosis de 0,6 J/cm2 durante 1 minuto, para un total de 2 a 3 sesiones. Las células intermedias de las mucosas mostraron el mayor nivel de multiplicación, la recuperación fue identificada a partir de las 48 horas de evaluación citológica, clínicamente al 4to. día. Se recomienda evaluar la eficiencia del nuevo esquema terapéutico con láser para esta afección, así como su costo y efectividad.A descriptive, longitudinal and prospective study consisting in the cytological and clinical description of the samples obtained in 150 patients with herpes labialis diagnosed and seen in different consultation rooms was conducted. Objective and subjective inclusion criteria were gathered. The samples of the affected surfaces obtained by curettage were fixed with cytospray and they were colored by using Papanicolau’s method. They were read at the beginning and 48 hours later to evaluate the recovery of the mucosa under the effects of the infrared laser of gallium and alluminum arsenide at doses of 0.6 J/cm3 during a minute for a total of 2 or 3 sessions. The intermediate cells of the mucosas showed the highest level of multiplication. The recovery was identified 48 hours after the cytologic evaluation and from the clinical point of view on the 4th day. It was recommended to evaluate the efficiency of the new therapeutic scheme with laser to treat this affection, as well

Recomendaciones de política para reducir el impacto al medio ambiente de la actividad petrolera en el Ecuador

OpenAIRE

Domínguez Pazmiño, José Luis

2010-01-01

Los daños o costos ambientales que la sociedad ha provocado al medio ambiente muestran ya sus efectos; la explotación petrolera irracional ha provocado contaminación en casi todos los ecosistemas del mundo afectando al suelo, agua, aire, fauna, flora y en especial a la vida del ser humano, tal es así que en aquellas comunidades que están en contacto con la actividad petrolera existe una mayor presencia de enfermedades relacionadas en comparación con aquellas en las que no hay actividad petrol...

Size- and morphology-dependent optical properties of ZnS:Al one-dimensional structures

Energy Technology Data Exchange (ETDEWEB)

Zeng, Xianghua, E-mail: xhzeng@yzu.edu.cn; Yan, Shunjun; Cui, Jieya; Liu, Hongfei; Dong, Jing; Xia, Weiwei; Zhou, Min; Chen, Haitao [Yangzhou University, School of Physics Science and Technology & Institute of Optoelectronic Technology (China)

2015-04-15

Typical morphology substrates can improve the efficiency of surface-enhanced Raman scattering; the need for SERS substrates of controlled morphology requires an extensive study. In this paper, one-dimensional ZnS:Al nanostructures with the width of approximately 300 nm and the length of tens um, and micro-scale structures with the width of several um and the length of tens um were synthesized via thermal evaporation on Au-coated silicon substrates and were used to study their size effects on Raman scattering and photoluminescent spectra. The photoluminescence spectra reveal the strongest green emission at a 5 at% Al source, which originates from the Al-dopant emission. The Raman spectra reveal that the size and morphology of the ZnS:Al nanowires greatly influences the Raman scattering, whereas the Al-dopant concentration has a lesser effect on the Raman scattering. The observed Raman scattering intensity of the saw-like ZnS:Al nanowires with the width of tens nm was eight times larger than that of the bulk sample. The enhanced Raman scattering can be regarded as multiple scattering and weak exciton—phonon coupling. The branched one-dimensional nanostructure can be used as an ideal substrate to enhance Raman scattering.

Quantification of Protein Biomarker Using SERS Nano-Stress Sensing with Peak Intensity Ratiometry

Science.gov (United States)

Goh, Douglas; Kong, Kien Voon; Jayakumar, Perumal; Gong, Tianxun; Dinish, U. S.; Olivo, Malini

We report a surface enhanced Raman spectroscopy (SERS) ratiometry method based on peak intensity coupled in a nano-stress sensing platform to detect and quantify biological molecules. Herein, we employed an antibody-conjugated p-aminothiophenol (ATP) functionalized on a bimetallic-film-over-nanosphere (BMFON) substrate as a sensitive SERS platform to detect human haptoglobin (Hp) protein, which is an acute phase protein and a biomarker for various cancers. Correlation between change in the ATP spectral characteristics and concentration of Hp protein was established by examining the peak intensity ratio at 1572cm-1 and 1592cm-1 that reflects the degree of stress experienced by the aromatic ring of ATP during Hp protein-antibody interaction. Development of this platform shows the potential in developing a low-cost and sensitive SERS sensor for the pre-screening of various biomarkers.

Fe2O3-Au hybrid nanoparticles for sensing applications via sers analysis

International Nuclear Information System (INIS)

Murph, Simona Hunyadi; Searles, Emily

2017-01-01

Nanoparticles with large amounts of surface area and unique characteristics that are distinct from their bulk material provide an interesting application in the enhancement of inelastic scattering signal. Surface Enhanced Raman Spectroscopy (SERS) strives to increase the Raman scattering effect when chemical species of interest are in the close proximity of metallic nnaostructures. Gold nanoparticles of various shapes have been used for sensing applications via SERS as they demonstrate the greatest effect of plasmonic behavior in the visible-near IR region of the spectrum. When coupled with other nanoparticles, namely iron oxide nanoparticles, hybrid structures with increased functionality were produced. Multifunctional iron oxide-gold hybrid nanostructures have been created via solution chemistries and investigated for analyte detection of a model analyte. By exploiting their magnetic properties, nanogaps or “hot spots” were rationally created and evaluated for SERS enhancement studies.

Combining surface enhanced Raman scattering (SERS) and high-performance thin-layer chromatography (HPTLC)

Science.gov (United States)

Koglin, E.

A new method for preparing SERS active surfaces using silver colloidal spheres deposited on HPTLC plates, used for thin-layer chromatography, is discussed in detail. The sensitivity of these activated HPTLC plates is so high that in-situ vibrational investigations of chromatogram spots are possible at the nanogram level. The HPTLC/SERS spectra of purine, benzoic acid and 1-nitro-pyrene adsorbed on silver colloidal activated silica gel plates are measured in the nanogram region. In addition we also report in this paper on the results of a feasibility study performed to evaluate the analytical potential of micro-Raman spectroscopy (triple monochromator, multichannel detection system) in SERS/HPTLC spot characterization. It permits the acquisition of Raman spectra from HPTLC spots down to 1 μm in size or other forms of microsamples approaching the picogram level in mass.

DETERMINANTES DEL ACCESO AL CRÉDITO DE LOS HOGARES COLOMBIANOS

OpenAIRE

Murcia Pabón, Andrés

2007-01-01

En este documento se busca identificar los determinantes de acceso al crédito de los hogar es colombianos; así, se encuentra que características tales como el ingreso, la riqueza, la posición geográfica, el acceso a la seguridad social, el nivel de educación y la edad influyen sobre la probabilidad de ser usuario de los servicios financieros acá analizados (tarjeta de crédito y crédito hipotecario). Adicionalmente, se encontró que una porción importante de población cuenta con unas condicione...

Nuevos esquemas de inmunoterapia específicas con alérgenos

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José Fernando Cantillo

2010-09-01

Con estos nuevos esquemas se han diseñado vacunas basadas en alérgenos recombinantes y variantes o péptidos derivados de éstos, para ser administrados solos o con adyuvantes en preparaciones que favorecen la captación y presentación antigénica por las células dendríticas o tienen como blanco las células efectoras, como mastocitos y basófilos. Los estudios in vitro, en modelos animales y algunos en fase clínica en humanos, indican que estas preparaciones pueden brindar protección frente a la exposición alergénica o mejorar la sintomatología, al inducir la producción de anticuerpos bloqueadores de la actividad de la IgE, de células T reguladoras y de citocinas del perfil Th1.

SERS spectra of pyridine adsorbed on nickel film prepared by magnetron sputtering

Science.gov (United States)

Li, Daoyong; Ouyang, Yu; Chen, Li; Cao, Weiran; Shi, Shaohua

2011-02-01

As a repeating well and cheaper enhancement substrate, the nickel film was fabricated with magnetron sputtering coating instrument. Surface enhanced Raman spectra (SERS) of pyridine adsorbed on this nickel film are compared with the experimental values of gaseous pyridine, the theoretical value of pyridine solution listed in other literatures and our method is better than electro-chemical etching electrode method for large scale preparation. The enhancement factor of the nickel film is calculated and the result indicates that magnetron sputtering coating technology is feasible for obtaining good SERS active surface.

Um modelo de otimização para alíquotas do IPTU socialmente mais justas

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José Delfino Sá

2013-02-01

Full Text Available Este artigo apresenta um modelo de otimização matemática não linear que determina novas alíquotas para o Imposto sobre a Propriedade Predial e Territorial Urbana (IPTU incidente sobre os apartamentos residenciais no município do Salvador (BA. São considerados a progressividade das alíquotas, os valores venais dos imóveis, as rendas médias dos contribuintes e as usuais metodologias de cálculo do valor do imposto. Os resultados obtidos na aplicação desse modelo demonstram ser possível tratar de forma objetiva e socialmente mais justa a definição das alíquotas de IPTU para todos os tipos de imóveis de um município.

Au@Ag core/shell cuboids and dumbbells: Optical properties and SERS response

Science.gov (United States)

Khlebtsov, Boris N.; Liu, Zhonghui; Ye, Jian; Khlebtsov, Nikolai G.

2015-12-01

Recent studies have conclusively shown that the plasmonic properties of Au nanorods can be finely controlled by Ag coating. Here, we investigate the effect of asymmetric silver overgrowth of Au nanorods on their extinction and surface-enhanced Raman scattering (SERS) properties for colloids and self-assembled monolayers. Au@Ag core/shell cuboids and dumbbells were fabricated through a seed-mediated anisotropic growth process, in which AgCl was reduced by use of Au nanorods with narrow size and shape distribution as seeds. Upon tailoring the reaction rate, monodisperse cuboids and dumbbells were synthesized and further transformed into water-soluble powders of PEGylated nanoparticles. The extinction spectra of AuNRs were in excellent agreement with T-matrix simulations based on size and shape distributions of randomly oriented particles. The multimodal plasmonic properties of the Au@Ag cuboids and dumbbells were investigated by comparing the experimental extinction spectra with finite-difference time-domain (FDTD) simulations. The SERS efficiencies of the Au@Ag cuboids and dumbbells were compared in two options: (1) individual SERS enhancers in colloids and (2) self-assembled monolayers formed on a silicon wafer by drop casting of nanopowder solutions mixed with a drop of Raman reporters. By using 1,4-aminothiophenol Raman reporter molecules, the analytical SERS enhancement factor (AEF) of the colloidal dumbbells was determined to be 5.1×106, which is an order of magnitude higher than the AEF=4.0×105 for the cuboids. This difference can be explained by better fitting of the dumbbell plasmon resonance to the excitation laser wavelength. In contrast to the colloidal measurements, the AEF=5×107 of self-assembled cuboid monolayers was almost twofold higher than that for dumbbell monolayers, as determined with rhodamine 6G Raman reporters. According to TEM data and electromagnetic simulations, the better SERS response of the self-assembled cuboids is due to uniform

SERS- and Electrochemically Active 3D Plasmonic Liquid Marbles for Molecular-Level Spectroelectrochemical Investigation of Microliter Reactions.

Science.gov (United States)

Koh, Charlynn Sher Lin; Lee, Hiang Kwee; Phan-Quang, Gia Chuong; Han, Xuemei; Lee, Mian Rong; Yang, Zhe; Ling, Xing Yi

2017-07-17

Liquid marbles are emergent microreactors owing to their isolated environment and the flexibility of materials used. Plasmonic liquid marbles (PLMs) are demonstrated as the smallest spectroelectrochemical microliter-scale reactor for concurrent spectro- and electrochemical analyses. The three-dimensional Ag shell of PLMs are exploited as a bifunctional surface-enhanced Raman scattering (SERS) platform and working electrode for redox process modulation. The combination of SERS and electrochemistry (EC) capabilities enables in situ molecular read-out of transient electrochemical species, and elucidate the potential-dependent and multi-step reaction dynamics. The 3D configuration of our PLM-based EC-SERS system exhibits 2-fold and 10-fold superior electrochemical and SERS performance than conventional 2D platforms. The rich molecular-level electrochemical insights and excellent EC-SERS capabilities offered by our 3D spectroelectrochemical system are pertinent in charge transfer processes. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A green, reusable SERS film with high sensitivity for in-situ detection of thiram in apple juice

Science.gov (United States)

Sun, Hongbao; Liu, Hai; Wu, Yiyong

2017-09-01

We report a green and reusable surface-enhanced Raman scattering (SERS) film based on PMMA/Ag NPs/graphene. By using this Raman substrate, the SERS signals of R6G were significantly enhanced reaching a minimum detectable concentration of 5 × 10-8 M, due to having lots of hot spots adhered backside to the exposed graphene. The SERS film can be used for in-situ monitoring of trace thiram in apple juice with a detection limit of 1 × 10-6 M (0.24 ppm), which is below the maximal residue limit (MRL) of 7 ppm in fruit prescribed by the U.S. Environmental Protection Agency (EPA). Furthermore, reusability studies show that the SERS film can be used repeatedly. In addition, the graphene-enhanced SERS technique shows great potential applications for the in-situ detection and identification of pesticide residues in environmental water, fruits and vegetables.

The hOGG1 Ser326Cys Gene Polymorphism and Breast Cancer Risk in Saudi Population.

Science.gov (United States)

Alanazi, Mohammed; Pathan, Akbar Ali Khan; Shaik, Jilani P; Alhadheq, Abdullah; Khan, Zahid; Khan, Wajahatullah; Al Naeem, Abdulrahman; Parine, Narasimha Reddy

2017-07-01

The purpose of this study was to test the association between human 8-oxoguanine glycosylase 1 (hOGG1) gene polymorphisms and susceptibility to breast cancer in Saudi population. We have also aimed to screen the hOGG1 Ser326Cys polymorphism effect on structural and functional properties of the hOGG1 protein using in silico tools. We have analyzed four SNPs of hOGG1 gene among Saudi breast cancer patients along with healthy controls. Genotypes were screened using TaqMan SNP genotype analysis method. Experimental data was analyzed using Chi-square, t test and logistic regression analysis using SPSS software (v.16). In silco analysis was conducted using discovery studio and HOPE program. Genotypic analysis showed that hOGG1 rs1052133 (Ser326Cys) is significantly associated with breast cancer samples in Saudi population, however rs293795 (T >C), rs2072668 (C>G) and rs2075747 (G >A) did not show any association with breast cancer. The hOGG1 SNP rs1052133 (Ser326Cys) minor allele T showed a significant association with breast cancer samples (OR = 1.78, χ2 = 7.86, p = 0.02024). In silico structural analysis was carried out to compare the wild type (Ser326) and mutant (Cys326) protein structures. The structural prediction studies revealed that Ser326Cys variant may destabilize the protein structure and it may disturb the hOGG1 function. Taken together this is the first In silico study report to confirm Ser326Cys variant effect on structural and functional properties of hOGG1 gene and Ser326Cys role in breast cancer susceptibility in Saudi population.

Projecte AIPCAP: Atenció inicial al pacient crític en atenció primària /

OpenAIRE

Cánovas Zaldúa, Yoseba,

2016-01-01

Introducció: Una prioritat formativa en emergències per als professionals d'atenció primària és el suport vital immediat (SVI) o atenció immediata al pacient crític, i que inclou tot el relacionat amb el suport vital bàsic (SVB) i l'ús del desfibril·lador automàtic (DEA). El curs de SVI està basat en la metodologia A(Airway) – B(Breathing) – C(Circulation) – D(Disability) – E(Exposure), i tot pacient crític hauria de ser tractat segons aquesta metodologia i amb un estricte ordre. En el nostre...

Being elderly with functional dependence and their family caregivers Ser anciano con incapacidad y sus cuidadores familiares Ser idoso com incapacidade e seus cuidadores familiares

Directory of Open Access Journals (Sweden)

Amanda Maria Souza de Oliveira

2012-01-01

Full Text Available OBJECTIVE: To identify the authors` point of discussion on the elderly with functional dependence, correlating it with the ontological time discussed in Heidegger. METHODS: This is a bibliographic, systematic and qualitative study. Data was collected in the Scientific Electronic Library Online database. A total of 123 studies were identified, 15 studies were included considering the inclusion criteria. RESULTS: Based on the semantic analysis of Bardin, the following categories of analysis were established: being caregiver for the elderly with functional dependence, being elderly with functional dependence, family dynamics. CONCLUSION: It was understood that factors related to the worldliness of these people as family relationships, support of formal and informal services, economic and social situation, among others, are part of the history of these people influencing their modes of being. Searching to understand these factors is important to promote the health of these people, thinking of the biological and existential care.OBJETIVO: Identificar el punto de discusión de los autores sobre el anciano con incapacidad funcional, correlacionando con el tiempo ontológico heideggeriano. MÉTODOS: Estudio de tipo bibliográfico, sistemático y cualitativo. Los datos fueron recolectados en el banco de datos del Scientific Electronic Library Online. De un total de 123 publicaciones identificadas, fueron seleccionados 15 estudios, de acuerdo a los criterios de inclusión adoptados. RESULTADOS: Con base en el análisis temático de Bardin, fueron constituídas las siguientes categorías de análisis: ser-cuidador del anciano con incapacidad, ser-anciano con incapacidad, dinámica familiar. CONCLUSIÓN: Se comprendió que los factores relacionados a a relación familiar, apoyo de los servicios formales e informales, situación económica, social, entre otras, forman parte de la historicidad de éstas influenciando su modo de ser. Es importante buscar la

MICROSTRUCTURAL ANALYSIS OF Al-Mg-Si-Zn ALLOY

Directory of Open Access Journals (Sweden)

SERGIO VALADEZ

2010-01-01

Full Text Available En un esfuerzo por desarrollar una nueva aleación con aplicación estructural, se ha desarrollado una aleación base Aluminio aleada con magnesio, silicio y zinc. La investigación pretende correlacionar la microestructura y con el tratamiento térmico. La aleación AlMgSiZn, fue elegida para ese propósito debido a la presencia de precipitados tanto en la matriz del aAl, como en los límites de grano, los cuales permiten una excelente relación entre la dureza y la resistencia mecánica. En lo que respecta a la microestructura, esta fue caracterizada bajo condición de colada y después de ser tratada térmicamente por envejecimiento. Este tratamiento fue realizado en dos etapas, la primera a 450ºC durante 3 horas que corresponde al tratamiento de homogeneización: y la segunda al proceso de envejecimiento artificial llevado a cabo a 160ºC durante 1hr. Los resultados indican la presencia de dendritas de aAl, además un eutéctico binario y partículas de Mg7Zn3 adentro de las regiones interdendríticas. El eutéctico y las partículas fueron modificados por el tratamiento de envejecido. Las observaciones realizadas con el microscopio electrónico de transmisión en especímenes con y sin tratamientos térmicos, demostraron una distribución uniforme de precipitados con diversas morfologías, tales como cúbico, esférico y plaqueta: para la matriz de aAl, los cuales no fueron detectados durante las observaciones en el microscopio electrónico de barrido.

Compreendendo o ser familiar de criança com Vírus da Imunodeficiência Humana/ Síndrome da Imunodeficiência Adquirida pelo olhar da complexidade Comprendiendo al familiar de un niño afectado por el Virus de la Inmunodeficiencia Humana/Síndrome de la Inmunodeficiencia Adquirida, bajo la perspectiva de la complejidad Understanding the family member of a child affected by Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome, from the perspective of complexity

Directory of Open Access Journals (Sweden)

Hilda Maria Barbosa de Freitas

2010-10-01

Full Text Available OBJETIVO: Compreender o significado do ser familiar de uma criança com Vírus da Imunodeficiência Humana/ Síndrome da Imunodeficiência Adquirida na perspectiva do pensamento complexo. MÉTODOS: Estudo qualitativo, exploratório; os dados foram coletados, entre julho e novembro de 2008, por meio de uma entrevista com cinco familiares de crianças com AIDS, abrigadas em uma instituição de apoio. RESULTADOS: O significado das falas codificadas e analisadas resultou em três categorias: Vivenciando a ordem, desordem e organização do ser familiar de uma criança com AIDS; Dialogando com as certezas e incertezas do revelar ou não o diagnóstico à criança com AIDS; e Confrontando-se com os limites do acaso, ocaso, viver e morrer. CONCLUSÃO: Evidenciou-se que ser familiar e cuidar de uma criança com AIDS, constitui-se em um processo complexo que requer, além de uma compreensão biopsicossócio-espiritual dos fatores que envolvem a doença e o ser doente, uma atitude de cuidado focada no ser humano como um ser uno, complexo e multidimensional.OBJETIVO: Comprender el significado del familiar de un niño portador del Virus de la Inmunodeficiencia Humana/Síndrome de la Inmunodeficiencia Adquirida bajo la perspectiva del pensamiento complejo. MÉTODOS: Se trata de estudio cualitativo y exploratorio; los datos fueron recolectados entre julio y noviembre de 2008, por medio de entrevistas con cinco familiares de niños con SIDA, que estaban acogidos en una institución de apoyo. RESULTADOS: El significado de las declaraciones codificadas y analizadas resultó en tres categorías: experimentando el orden, desorden y la organización del familiar de un niño con SIDA; dialogando con la seguridad y la duda de revelar el diagnóstico al niño con SIDA; y, enfrentando los límites del acaso, ocaso, vivir y morir. CONCLUSIÓN: Se evidenció que ser familiar y cuidar de un niño con SIDA, constituye un proceso complejo que requiere, además de una

Introducción al tema monográfico

Directory of Open Access Journals (Sweden)

Sofía Salas Ibarra

2009-06-01

Full Text Available Este número de Ars Medica está por entero dedicado al tema de Anticoncepción de Emergencia (AE y a la discusión de sus aspectos biológicos, éticos, sociales y jurídicos, incluyendo un análisis sobre los aspectos científicos y jurídicos contenidos en el reciente fallo del Tribunal Constitucional de Chile. Como es de conocimiento público, con fecha 18 de abril de 2008 dicho tribunal dictó sentencia sobre el requerimiento presentado por un grupo de diputados en contra del decreto supremo Nº 48 de 2007 del Ministerio de Salud, el cual prohíbe la entrega de AE en los servicios públicos de salud. Pocos días después, el Gobierno de Chile declaró la supresión de las normas sobre AE de las Normas Nacionales sobre Regulación de la Fertilidad, que forman parte del decreto supremo Nº 48, de 2007, del Ministerio de Salud, por ser inconstitucionales de acuerdo al fallo antes señalado1

Alkaline phosphatase labeled SERS active sandwich immunoassay for detection of Escherichia coli

Science.gov (United States)

Bozkurt, Akif Goktug; Buyukgoz, Guluzar Gorkem; Soforoglu, Mehmet; Tamer, Ugur; Suludere, Zekiye; Boyaci, Ismail Hakki

2018-04-01

In this study, a sandwich immunoassay method utilizing enzymatic activity of alkaline phosphatase (ALP) on 5-bromo-4-chloro-3-indolyl phosphate (BCIP) for Escherichia coli (E. coli) detection was developed using surface enhanced Raman spectroscopy (SERS). For this purpose, spherical magnetic gold coated core-shell nanoparticles (MNPs-Au) and rod shape gold nanoparticles (Au-NRs) were synthesized and modified for immunomagnetic separation (IMS) of E. coli from the solution. In order to specify the developed method to ALP activity, Au-NRs were labeled with this enzyme. After successful construction of the immunoassay, BCIP substrate was added to produce the SERS-active product; 5-bromo-4-chloro-3-indole (BCI). A good linearity (R2 = 0.992) was established between the specific SERS intensity of BCI at 600 cm- 1 and logarithmic E. coli concentration in the range of 1.7 × 101-1.7 × 106 cfu mL- 1. LOD and LOQ values were also calculated and found to be 10 cfu mL- 1 and 30 cfu mL- 1, respectively.

Low-cost and large-scale flexible SERS-cotton fabric as a wipe substrate for surface trace analysis

Science.gov (United States)

Chen, Yanmin; Ge, Fengyan; Guang, Shanyi; Cai, Zaisheng

2018-04-01

The large-scale surface enhanced Raman scattering (SERS) cotton fabrics were fabricated based on traditional woven ones using a dyeing-like method of vat dyes, where silver nanoparticles (Ag NPs) were in-situ synthesized by 'dipping-reducing-drying' process. By controlling the concentration of AgNO3 solution, the optimal SERS cotton fabric was obtained, which had a homogeneous close packing of Ag NPs. The SERS cotton fabric was employed to detect p-Aminothiophenol (PATP). It was found that the new fabric possessed excellent reproducibility (about 20%), long-term stability (about 57 days) and high SERS sensitivity with a detected concentration as low as 10-12 M. Furthermore, owing to the excellent mechanical flexibility and good absorption ability, the SERS cotton fabric was employed to detect carbaryl on the surface of an apple by simply swabbing, which showed great potential in fast trace analysis. More importantly, this study may realize large-scale production with low cost by a traditional cotton fabric.

Plasmonic nanoholes as SERS devices for biosensing applications: An easy route for nanostructures fabrication on glass substrates

KAUST Repository

Candeloro, Patrizio

2016-12-26

Surface enhanced Raman spectroscopy (SERS) has been largely exploited in the last decade for biochemical and biomedical research. But some issues still require attention before transferring SERS to bioclinical routinely practices, such as reproducibility, quantitative analysis and signal background interference. In this work we propose an easy and cheap route, based on a template stripping technique, for producing plasmonic nanostructured films with SERS capabilities. We focus our attention to nanoholes in a continuous gold film, conversely to the majority of the literature which is dealing with individual nanostructures. Plasmon resonances occur at the holes edges, thus enabling the possibility of SERS signals from biomolecules and the potential application as biosensors. One advantage of the nanoholes patterned film is the optical-subdiffraction pitch, which prevents any Raman and/or fluorescence signal arising from the bottom slide. This effect paves the way to standard glass slides, much cheaper than CaF2 ones, as suitable substrates for SERS devices, without any interfering signal coming from the glass itself.

Quaternized chitosan/silver nanoparticles composite as a SERS substrate for detecting tricyclazole and Sudan I

International Nuclear Information System (INIS)

Chen, Kaihang; Shen, Zuguang; Luo, Jiwen; Wang, Xiaoying; Sun, Runcang

2015-01-01

Graphical abstract: - Highlights: • Synthesis optimization of Ag NPs with quaternized chitosan (QCS) was studied. • The size of Ag NPs was tuned by changing the DS and Mw of QCS. • QCS/Ag NPs exhibited much better SERS performance than Ag NPs without free QCS. • QCS/Ag NPs as SERS substrate detected tricyclazole in low concentration of 50 ppb. • QCS/Ag NPs as SERS substrate detected Sudan I with the detection limit of 10 ppm. - Abstract: There is an urgent need to develop a highly sensitive detection system for detecting trace amounts of food contaminants. In this study, optimal synthesis of silver nanoparticles (Ag NPs) with stable and narrow size distribution in the range of 15–25 nm was performed under microwave irradiation, using quaternized chitosan (QCS) as reducing and stabilizing agent. The results showed that the ratio of QCS to [Ag(NH 3 ) 2 ] + , reaction temperature, irradiation time, the degree of substitution (DS) and molecular weight (Mw) of QCS had obvious effects on the formation, particle size and size distribution of Ag NPs. In addition, utilizing QCS/Ag NPs composite as SERS substrate, tricyclazole and Sudan I could be rapidly and sensitively detected with the limit of detection (LOD) as low as 50 ppb and 10 ppm, respectively. Compared with previously reported works, our detection system are of great stability and operability. The QCS was coated on the surface of Ag core, avoiding aggregation of Ag NPs and creating hot spots, in turn, providing superior amplification of SERS. Thus, it is believed that the QCS/Ag NPs composite could be considered as an ideal SERS-active substrate for detection of food contaminants

Subnanomolar Sensitivity of Filter Paper-Based SERS Sensor for Pesticide Detection by Hydrophobicity Change of Paper Surface.

Science.gov (United States)

Lee, Minwoo; Oh, Kyudeok; Choi, Han-Kyu; Lee, Sung Gun; Youn, Hye Jung; Lee, Hak Lae; Jeong, Dae Hong

2018-01-26

As a cost-effective approach for detecting trace amounts of pesticides, filter paper-based SERS sensors have been the subject of intensive research. One of the hurdles to overcome is the difficulty of retaining nanoparticles on the surface of the paper because of the hydrophilic nature of the cellulose fibers in paper. This reduces the sensitivity and reproducibility of paper-based SERS sensors due to the low density of nanoparticles and short retention time of analytes on the paper surface. In this study, filter paper was treated with alkyl ketene dimer (AKD) to modify its property from hydrophilic to hydrophobic. AKD treatment increased the contact angle of the aqueous silver nanoparticle (AgNP) dispersion, which consequently increased the density of AgNPs. The retention time of the analyte was also increased by preventing its rapid absorption into the filter paper. The SERS signal was strongly enhanced by the increased number of SERS hot spots owing to the increased density of AgNPs on a small contact area of the filter surface. The reproducibility and sensitivity of the SERS signal were optimized by controlling the distribution of AgNPs on the surface of the filter paper by adjusting the concentration of the AgNP solution. Using this SERS sensor with a hydrophobicity-modified filter paper, the spot-to-spot variation of the SERS intensity of 25 spots of 4-aminothiophenol was 6.19%, and the limits of detection of thiram and ferbam as test pesticides were measured to be 0.46 nM and 0.49 nM, respectively. These proof-of-concept results indicate that this paper-based SERS sensor can serve for highly sensitive pesticide detection with low cost and easy fabrication.

Silver-gelatine bionanocomposites for qualitative detection of a pesticide by SERS.

Science.gov (United States)

Fateixa, S; Soares, S F; Daniel-da-Silva, A L; Nogueira, H I S; Trindade, T

2015-03-07

The controlled release of pesticides using hydrogel vehicles is an important procedure to limit the amount of these compounds in the environment, providing an effective way for crop protection. A key-step in the formulation of new materials for these purposes encompasses the monitoring of available pesticides in the gel matrix under variable working conditions. In this work, we report a series of bionanocomposites made of Ag nanoparticles (NPs) and gelatine A for the surface enhanced Raman scattering (SERS) detection of sodium diethyldithiocarbamate (EtDTC) as a pesticide model. These studies demonstrate the effectiveness of these substrates for the detection of EtDTC in aqueous solutions in a concentration as low as 10(-5) M. We have monitored the Raman signal enhancement of this analyte in bionanocomposites having an increasing amount of gelatine due to their relevance in formulating hydrogels of variable gel strengths. Under these conditions, the bionanocomposites have shown an effective SERS activity using EtDTC, demonstrating their effectiveness in the qualitative detection of this analyte. Finally, experiments involving the release of EtDTC from Ag/gelatine samples have been monitored by SERS, which attest the potential of this spectroscopic method in the laboratorial monitoring of hydrogels for pesticide release.

Porous plasmonic nanocomposites for SERS substrates fabricated by two-step laser method

Energy Technology Data Exchange (ETDEWEB)

Koleva, M.E., E-mail: mihaela_ek@yahoo.com [Institute of Electronics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chaussee blvd., Sofia 1784 (Bulgaria); International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044 (Japan); Nedyalkov, N.N.; Atanasov, P.A. [Institute of Electronics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chaussee blvd., Sofia 1784 (Bulgaria); Gerlach, J.W.; Hirsch, D.; Prager, A.; Rauschenbach, B. [Leibniz Institute of Surface Modification (IOM), Permoserstrasse 15, D-04318 Leipzig (Germany); Fukata, N.; Jevasuwan, W. [International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044 (Japan)

2016-04-25

This research is focused on investigation of coupled plasmonic/metal-semiconductor nanomaterials. A two-step laser-assisted method is demonstrated for formation of plasmonic Ag nanoparticles (NPs) distributed into porous metal–oxide semiconductors. The mosaic Ag-ZnO target is used for laser ablation and, subsequently, laser annealing of the deposited layer is applied. The plasmon resonance properties of the nanostructures produced are confirmed by optical transmission spectroscopy. The wurtzite structure of ZnO is formed with tilted c-axis orientation and, respectively, a mixed Raman mode appears at 580 cm{sup −1}. The oxygen pressure applied during a deposition process has impact on the morphology and thickness of the porous nanostructures, but not on the size and size distribution of AgNPs. The porous nanocomposites exhibited potential for SERS applications, most pronounced for the oxygen deficient sample, grown at lower oxygen pressure. The observed considerable SERS enhancement of R6G molecules on AgNP/ZnO can be attributed to the ZnO-to-molecule charge transfer contribution, enhanced by the additional electrons from the local surface plasmon resonance (LSPR) of AgNPs to the ZnO through the conduction band. - Highlights: • Porous AgNPs/ZnO composites are obtained by laser deposition and laser annealing. • Morphology and properties depend on growth oxygen pressure. • The emergence of mixed-symmetry Raman mode at 580 cm{sup −1} is registered. • The AgNPs/ZnO porous nanocomposites are suitable for SERS-active substrates. • The charge transfer enhanced by LSPR has a contribution to SERS effect.

La respuesta hegeliana al acosmismo de Spinoza. El alma como primera manifestación del universo en el espíritu

OpenAIRE

Padial, Juan J.

2013-01-01

La acusación hegeliana de acosmismo a Spinoza no tiene repercusiones tan sólo en el ámbito metafísico, sino también en el an-tropológico. La filosofía del espíritu subjetivo se inaugura con una discusión sobre la presencia del cosmos en el ser humano y el puesto de éste en el universo. Los hábitos, cuyo estudio se realiza al final de la primera parte de la filosofía del espíritu subjetivo, posibilitan que la libertad llegue a las dimensiones naturales del ser humano. Universidad de Málaga....

SERS spectroscopy of kaempferol and galangin under the interaction of human serum albumin with adsorbed silver nanoparticles

Science.gov (United States)

Zhang, Wei; Bai, Xueyuan; Wang, Yingping; Zhao, Bing; Zhao, Daqing; Zhao, Yu

Raman and surface-enhanced Raman scattering (SERS) spectroscopy were employed to probe the interaction of the flavonol drugs, kaempferol and galangin, with human serum albumin (HSA). SERS spectra of both flavonol derivatives were obtained from a colloidal silver surface in physiological condition, based on the high performance of the enhanced substrate, the most enhanced modes of kaempferol and galangin were those with certain motions perpendicular to the metal surface. The SERS spectra were allowed to predict similar orientation geometry for both of the drugs on the colloidal surface with minor difference. In addition, both flavonols-HSA complexes were prepared in different concentration ratios and the orientated differences between kaempferol and galangin were investigated by SERS.

SERS activity of Au nanoparticles coated on an array of carbon nanotube nested into silicon nanoporous pillar

International Nuclear Information System (INIS)

Jiang Weifen; Zhang Yanfeng; Wang Yusheng; Xu Lei; Li Xinjian

2011-01-01

A novel composite structure, Au nanoparticles coated on a nest-shaped array of carbon nanotube nested into a silicon nanoporous pillar array (Au/NACNT/Si-NPA), was fabricated for surface-enhanced Raman scattering (SERS). The morphology of the Au/NACNT/Si-NPA composite structure was characterized with the aid of scanning electron microscopy, X-ray diffraction instrumentation and Transmission electron microscopy. Compared with SERS of rhodamine 6G (R6G) adsorbed on SERS-active Au substrate reported, the SERS signals of R6G adsorbed on these gold nanoparticles were obviously improved. This was attributed to the enlarged specific surface area for adsorption of target molecules brought by the nest-shaped CNTs structure.

Heidegger: o estudo dos fenômenos humanos baseados na existência humana como ser-aí (Dasein

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Ida Elizabeth Cardinalli

2015-08-01

Full Text Available O presente artigo pretende esclarecer a posição crítica do filósofo Martin Heidegger, explicitada no livro Seminários de Zollikon, em relação à transposição do método da ciência natural moderna para o estudo dos fenômenos humanos e apresentar sua proposição de um método mais pertinente ao estudo da existência humana. O autor propõe indicações de um método baseado na compreensão do existir humano como "ser-aí" e "ser-no-mundo" e também nos existenciais descritos em Ser e tempo, tais como espacialidade, temporalidade, ser-com-o-outro e corporeidade. Ao mesmo tempo, destaca que os fenômenos humanos não deveriam ser submetidos e circunscritos às descrições ontológicas dos existenciais, quando o método visa ao esclarecimento das experiências específicas e singulares de cada ser humano.

Organelle-targeting surface-enhanced Raman scattering (SERS) nanosensors for subcellular pH sensing.

Science.gov (United States)

Shen, Yanting; Liang, Lijia; Zhang, Shuqin; Huang, Dianshuai; Zhang, Jing; Xu, Shuping; Liang, Chongyang; Xu, Weiqing

2018-01-25

The pH value of subcellular organelles in living cells is a significant parameter in the physiological activities of cells. Its abnormal fluctuations are commonly believed to be associated with cancers and other diseases. Herein, a series of surface-enhanced Raman scattering (SERS) nanosensors with high sensitivity and targeting function was prepared for the quantification and monitoring of pH values in mitochondria, nucleus, and lysosome. The nanosensors were composed of gold nanorods (AuNRs) functionalized with a pH-responsive molecule (4-mercaptopyridine, MPy) and peptides that could specifically deliver the AuNRs to the targeting subcellular organelles. The localization of our prepared nanoprobes in specific organelles was confirmed by super-high resolution fluorescence imaging and bio-transmission electron microscopy (TEM) methods. By the targeting ability, the pH values of the specific organelles can be determined by monitoring the vibrational spectral changes of MPy with different pH values. Compared to the cases of reported lysosome and cytoplasm SERS pH sensors, more accurate pH values of mitochondria and nucleus, which could be two additional intracellular tracers for subcellular microenvironments, were disclosed by this SERS approach, further improving the accuracy of discrimination of related diseases. Our sensitive SERS strategy can also be employed to explore crucial physiological and biological processes that are related to subcellular pH fluctuations.

Thin silica shell coated Ag assembled nanostructures for expanding generality of SERS analytes.

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Myeong Geun Cha

Full Text Available Surface-enhanced Raman scattering (SERS provides a unique non-destructive spectroscopic fingerprint for chemical detection. However, intrinsic differences in affinity of analyte molecules to metal surface hinder SERS as a universal quantitative detection tool for various analyte molecules simultaneously. This must be overcome while keeping close proximity of analyte molecules to the metal surface. Moreover, assembled metal nanoparticles (NPs structures might be beneficial for sensitive and reliable detection of chemicals than single NP structures. For this purpose, here we introduce thin silica-coated and assembled Ag NPs (SiO2@Ag@SiO2 NPs for simultaneous and quantitative detection of chemicals that have different intrinsic affinities to silver metal. These SiO2@Ag@SiO2 NPs could detect each SERS peak of aniline or 4-aminothiophenol (4-ATP from the mixture with limits of detection (LOD of 93 ppm and 54 ppb, respectively. E-field distribution based on interparticle distance was simulated using discrete dipole approximation (DDA calculation to gain insight into enhanced scattering of these thin silica coated Ag NP assemblies. These NPs were successfully applied to detect aniline in river water and tap water. Results suggest that SiO2@Ag@SiO2 NP-based SERS detection systems can be used as a simple and universal detection tool for environment pollutants and food safety.

Effect of Irrigation Levels on Dissolved Organic Carbon Soil Distribution and the Depth Mobility of Chlorpyrifos Efecto de Niveles de Riego sobre la Distribución de Carbono Orgánico Disuelto en el Suelo y La Mobility en Profundidad de Clorpirifos

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Julio Junod

2009-09-01

Full Text Available Water flows provided by irrigation systems may be associated with dissolved organic carbon (DOC content in the soil solution and may modify the mobility of pesticides, such as chlorpyrifos (CHP. These compounds were analyzed under field conditions, evaluating their distribution in the soil profile under excessive irrigation in a Humic Haploxerand soil. The trial was carried out in soil columns located under the canopy of apple trees (Malus domestica Borkh. in an orchard located in the Bío-Bío Region, Chile. The insecticide CHP was applied 120 g hL-1, and later the natural run off was collected from the foliage to the columns. Surface irrigation was used as a control, the equivalent to 4 L h-1 weekly, plus two treatments over the columns of 6 and 8 L h-1 per pulse, respectively. Samples were obtained at three column depths: 0-5, 5-20 and 20-30 cm. The results showed that in spite of the fact there was no interaction between depth and irrigation, a greater concentration of CHP was observed in the samples with greater water flow, with significant differences between the treatments at a depth of 20-30 cm, which suggests some level of influence on vertical mobility. DOC shows stratification with greater concentrations at the surface and lower concentrations at depth, with significant differences between the superficial stratum (0-5 cm and the lower strata (5-20, 20-30 cm. These results are discussed in relation to explaining the movement of CHP in the soil profile.Los flujos de agua aportados por los sistemas de riego pueden estar asociados al contenido de carbono orgánico disuelto (DOC en la solución del suelo y modificar la movilidad de pesticidas como el clorpirifos (CHP. Se analizan estos compuestos bajo condiciones de campo, evaluando su distribución en el perfil de suelo ante un exceso de riego en un suelo Humic Haploxerands. El ensayo se desarrolló en columnas de suelo ubicadas bajo la canopia de un huerto de manzanos (Malus domestica

A study on the correlation between the dewetting temperature of Ag film and SERS intensity.

Science.gov (United States)

Quan, Jiamin; Zhang, Jie; Qi, Xueqiang; Li, Junying; Wang, Ning; Zhu, Yong

2017-11-07

The thermally dewetted metal nano-islands have been actively investigated as cost-effective SERS-active substrates with a large area, good reproducibility and repeatability via simple fabrication process. However, the correlation between the dewetting temperature of metal film and SERS intensity hasn't been systematically studied. In this work, taking Ag nano-islands (AgNIs) as an example, we reported a strategy to investigate the correlation between the dewetting temperature of metal film and SERS intensity. We described the morphology evolution of AgNIs on the SiO 2 planar substrate in different temperatures and got the quantitative information in surface-limited diffusion process (SLDP) as a function of annealing temperature via classical mean-field nucleation theory. Those functions were further used in the simulation of electromagnetic field to obtain the correlation between the dewetting temperature of Ag film and theoretical analysis. In addition, Raman mapping was done on samples annealed at different temperatures, with R6G as an analyte, to accomplish the analysis of the correlation between the dewetting temperature of Ag film and SERS intensity, which is consistent with the theoretical analysis. For SLDP, we used the morphological characterization of five samples prepared by different annealing temperatures to successfully illustrate the change in SERS intensity with the temperature fluctuation, obtaining a small deviation between the experimental results and theoretic prediction.

con bajo peso al nacer

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Adriana Mora Antó

2005-01-01

Full Text Available Esta investigación dio cuenta de la relación entre el estilo de funcionamiento familiar, los patrones de crianza y las edades de desarrollo evolutivo en niños, nacidos con bajo peso. El estudio descriptivo correlacional se realizó con 41 niños y sus madres, aplicándose cuestionarios sobre funcionamiento familiar, prácticas de crianza y desarrollo infantil. Los resultados señalaron la existencia de un funcionamiento familiar caracterizado por una cohesión amalgamada y una adaptabilidad caótica, una disciplina complaciente, falta de control y de límites claros en la díada madre-hijo. Se trataba de familias monoparentales, donde la temprana edad de concepción, el madresolterismo y el apoyo de la familia extensa eran constantes. Las edades evolutivas registradas indicaron un desarrollo inferior a la edad cronológica, en la mayor parte de los casos; sin embargo, éstas tendieron a ser superiores al compararlas con la edades reales de los infantes. No se encontró una correlación estadísticamente significativa entre la edad de desarrollo y los diferentes factores del funcionamiento familiar para algunos de los rangos de edad considerados; sin embargo, no se lo descartó por completo, especialmente en lo referente al optimismo familiar

EL MODELO ESPAÑOL DE RECONOCIMIENTO MÉDICO Y PSICOTÉCNICO EN EL CONTEXTO DE LA 2ª DIRECTIVA (91/439/CEE. RESULTADOS AL SER APLICADO SOBRE UN GRUPO ESPECÍFICO DE CONDUCTORES (45 a 70 AÑOS

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Luis Montoro González

2003-01-01

Full Text Available Fundamento: Con la Directiva 91/439/CEE se inició lo que en un futuro será el permiso de conducir comunitario. Ahora bien, en el momento actual existen diferencias en cuanto a las condiciones de aptitud y a los periodos de prórroga del mismo. El presente estudio ofrece los resultados del reconocimiento médico y psicotécnico realizado a 606 conductores. Métodos: 606 conductores que reunían las siguientes características: edad entre 45 y 70 años, revisan el permiso del grupo 1 (B; hombres y mujeres; y finalmente, el periodo de prorroga es < 5 años. Posteriormente, se hace un seguimiento de los que, siendo aptos, regresan al centro y de esta manera podemos comprobar si existen modificaciones en cuanto al resultado del reconocimiento. Resultados: El 86,47% fueron aptos, un 12,21% aptos con restricción y un 1,65% no aptos. Por grupos de edad se apreció que a medida que avanza la edad disminuye el porcentaje de aptos y aumenta el de aptos con restricción (de 45-49 años hay un 93,19% de aptos, mientras que en el grupo de 65-69 se sitúa en un 67,35%. A los 5 años, un 11,13% de los conductores aptos habían modificado su condición (9,98% aptos con restricción; 1,15% no aptos, apreciándose que por grupos de edad también existen diferencias significativas (en el grupo de 45-49 años modifican su condición un 6,8%, mientras que en el de 65-69 lo hace un 18,1%. Conclusiones: De esta manera, podemos decir que existen diferencias entre las distintas edades y las condiciones de aptitud para la conducción, y también que un porcentaje significativo de conductores aptos modifica su condición de aptitud transcurridos al menos 5 años.

Smart SERS Hot Spots: Single Molecules Can Be Positioned in a Plasmonic Nanojunction Using Host-Guest Chemistry.

Science.gov (United States)

Kim, Nam Hoon; Hwang, Wooseup; Baek, Kangkyun; Rohman, Md Rumum; Kim, Jeehong; Kim, Hyun Woo; Mun, Jungho; Lee, So Young; Yun, Gyeongwon; Murray, James; Ha, Ji Won; Rho, Junsuk; Moskovits, Martin; Kim, Kimoon

2018-04-04

Single-molecule surface-enhanced Raman spectroscopy (SERS) offers new opportunities for exploring the complex chemical and biological processes that cannot be easily probed using ensemble techniques. However, the ability to place the single molecule of interest reliably within a hot spot, to enable its analysis at the single-molecule level, remains challenging. Here we describe a novel strategy for locating and securing a single target analyte in a SERS hot spot at a plasmonic nanojunction. The "smart" hot spot was generated by employing a thiol-functionalized cucurbit[6]uril (CB[6]) as a molecular spacer linking a silver nanoparticle to a metal substrate. This approach also permits one to study molecules chemically reluctant to enter the hot spot, by conjugating them to a moiety, such as spermine, that has a high affinity for CB[6]. The hot spot can accommodate at most a few, and often only a single, analyte molecule. Bianalyte experiments revealed that one can reproducibly treat the SERS substrate such that 96% of the hot spots contain a single analyte molecule. Furthermore, by utilizing a series of molecules each consisting of spermine bound to perylene bisimide, a bright SERS molecule, with polymethylene linkers of varying lengths, the SERS intensity as a function of distance from the center of the hot spot could be measured. The SERS enhancement was found to decrease as 1 over the square of the distance from the center of the hot spot, and the single-molecule SERS cross sections were found to increase with AgNP diameter.

Synthesis and characterization of Ag@Cu nano/microstructure ordered arrays as SERS-active substrates

Science.gov (United States)

Zhang, Pinhua; Cui, Guangliang; Xiao, Chuanhai; Zhang, Mingzhe; Chen, Li; Shi, Changmin

2016-06-01

We fabricated an Ag decorated Cu (Ag@Cu) nano/microstructure ordered array by facile template-free 2D electrodeposition combined with a galvanic reduction method for SERS applications. The Cu nano/microstructure ordered arrays were first synthesized by a 2D electrodeposition method, then Ag nanocubes were decorated on the arrays by galvanic reduction without any capping agent. The pollution-free surface and edge-to-face heterostructure of Ag nanocubes and Cu nano/microstructure arrays provide the powerful field-enhancements for SERS performance. The results verified that the Ag@Cu nano/microstructure ordered arrays have excellent activity for 4-Mercaptopyridine, and the sensitivity limit is as low as 10-8 M. Therefore, this facile route provides a useful platform for the fabrication of a SERS substrate based on nano/microstructure ordered arrays.

Liposucción láser-asistida en ginecomastia: seguimiento ecográfico y estadístico de los efectos observados de retracción cutánea

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M.A. Trelles

2013-12-01

Full Text Available Valoramos por ecografía y estadísticamente la eficacia de la liposucción láser-asistida en casos de ginecomastia, teniendo en cuenta la respuesta de retracción de la piel, la rapidez de la recuperación del paciente, y el grado de satisfacción que originan los resultados. Presentamos un estudio prospectivo de 28 pacientes con ginecomastia de diferente grado, tratados mediante liposucción asistida por láser de Diodo de 1470 nm, previa sedación y con anestesia tumescente. El láser se programó a 15 Watios (W en emisión continua y se administraron 8 a 12 kilojulios (kJ por cada mama. No se realizaron escisiones de piel ni se emplearon drenajes. Se realizó valoración objetiva y subjetiva empleando la misma escala visual analógica (VAS completada por médicos y pacientes. Se tomaron fotografías antes y 6 meses después de la intervención, y se realizaron mediciones del perímetro torácico y del diámetro de las areolas. El seguimiento ecográfico de las áreas tratadas fue comparativo antes y 6 meses después del tratamiento. Para el estudio estadístico se empleó t de Student como test de contraste. No observamos complicaciones, como signos de isquemia o quemaduras cutáneas. La disminución del perímetro torácico y del diámetro de las areolas fue estadísticamente significativa. Tanto la valoración objetiva como la subjetiva alcanzaron resultados superiores al 90 %. Mediante la ecografía también se demostró disminución, estadísticamente significativa, de la banda de tejido graso subcutáneo (p < 0,05 al comparar las imágenes de antes y 6 meses después del tratamiento. La recuperación laboral se realizó en un promedio de 3 días. En conclusión, creemos que la liposucción láser-asistida es un método eficaz y reproducible, comprobado ecográfica y estadísticamente, que alcanza buenos resultados con menos trauma quirúrgico, lo que conlleva un alto grado de satisfacción por parte de los pacientes.

Violencia intrafamiliar como causa de trastorno depresivo en mujeres que acuden al Centro de Apoyo Integral las tres Manuelas y al Hospital Cantonal de Sangolquí durante el año 2011

OpenAIRE

Moreno Ronquillo, Tania Paulina

2014-01-01

El Trastorno Depresivo ocupa el primer lugar dentro de las causas de discapacidad en el mundo. La Violencia Intrafamiliar es un grave problema de Salud Pública, pudiendo ser una causa importante de depresión. Objetivo. Determinar si la Violencia Intrafamiliar es causa del desarrollo de Trastorno Depresivo en mujeres que acuden al Centro de Equidad y Justicia “Las Tres Manuelas”. Diseño: Observacional, Epidemiológico Analítico Longitudinal de casos y controles. Lugar y sujetos. El presente est...

Two-step fabrication of nanoporous copper films with tunable morphology for SERS application

Science.gov (United States)

Diao, Fangyuan; Xiao, Xinxin; Luo, Bing; Sun, Hui; Ding, Fei; Ci, Lijie; Si, Pengchao

2018-01-01

It is important to design and fabricate nanoporous metals (NPMs) with optimized microstructures for specific applications. In this contribution, nanoporous coppers (NPCs) with controllable thicknesses and pore sizes were fabricated via the combination of a co-sputtering of Cu/Ti with a subsequent dealloying process. The effect of dealloying time on porous morphology and the corresponding surface enhanced Raman scattering (SERS) behaviors were systematically investigated. Transmission electron microscopy (TEM) identified the presences of the gaps formed between ligaments and also the nanobumps on the nanoparticle-aggregated ligament surface, which were likely to contribute as the ;hot spots; for electromagnetic enhancement. The optimal NPC film exhibited excellent SERS performance towards Rhodamine 6G (R6G) with a low limiting detection (10-9 M), along with good uniformity and reproducibility. The calculated enhancement factor of ca. 4.71 × 107 was over Au substrates and comparable to Ag systems, promising the proposed NPC as a cheap candidate for high-performance SERS substrate.

Ser derivation and power optimization of a two-way multirelay cooperative communication system

International Nuclear Information System (INIS)

Rehman, S.U.; Shah, S.I.; Fareed, M.M.

2014-01-01

In this paper, we consider Rayleigh fading based cooperative communication system with AaF (Amplify and Forward) relaying using multiple relays. We take spectrally efficient two-way model of cooperative communication terminals and formulate performance evaluation framework in terms of SER (Symbol Error Rate). We not only consider fading channel for this performance evaluation but also consider the effect of relay terminal location into our model which does not require any CSI (Channel State Information) at transmitting nodes. We have proposed power allocation framework for these nodes and analytically derived SER performance results. We have numerically evaluated this framework for power optimization as well as minimizing required SER. Significant performance improvement as compared with equal power sharing among the cooperating terminals is achieved using our proposed framework. It is shown that virtual cooperative antenna configurations is able to demonstrate up to 3dB gain as compared with co-located antenna configurations. Thus incorporating relay location information for performance evaluation results significant power savings. (author)

Controllable Ag nanostructure patterning in a microfluidic channel for real-time SERS systems.

Science.gov (United States)

Leem, Juyoung; Kang, Hyun Wook; Ko, Seung Hwan; Sung, Hyung Jin

2014-03-07

We present a microfluidic patterning system for fabricating nanostructured Ag thin films via a polyol method. The fabricated Ag thin films can be used immediately in a real-time SERS sensing system. The Ag thin films are formed on the inner surfaces of a microfluidic channel so that a Ag-patterned Si wafer and a Ag-patterned PDMS channel are produced by the fabrication. The optimum sensing region and fabrication duration for effective SERS detection were determined. As SERS active substrates, the patterned Ag thin films exhibit an enhancement factor (EF) of 4.25 × 10(10). The Ag-patterned polymer channel was attached to a glass substrate and used as a microfluidic sensing system for the real-time monitoring of biomolecule concentrations. This microfluidic patterning system provides a low-cost process for the fabrication of materials that are useful in medical and pharmaceutical detection and can be employed in mass production.

Design of Hybrid Nanostructural Arrays to Manipulate SERS-Active Substrates by Nanosphere Lithography.

Science.gov (United States)

Zhao, Xiaoyu; Wen, Jiahong; Zhang, Mengning; Wang, Dunhui; Wang, Yaxin; Chen, Lei; Zhang, Yongjun; Yang, Jinghai; Du, Youwei

2017-03-01

An easy-handling and low-cost method is utilized to controllably fabricate nanopattern arrays as the surface-enhanced Raman scattering (SERS) active substrates with high density of SERS-active areas (hot spots). A hybrid silver array of nanocaps and nanotriangles are prepared by combining magnetron sputtering and plasma etching. By adjusting the etching time of polystyrene (PS) colloid spheres array in silver nanobowls, the morphology of the arrays can be easily manipulated to control the formation and distribution of hot spots. The experimental results show that the hybrid nanostructural arrays have large enhancement factor, which is estimated to be seven times larger than that in the array of nanocaps and three times larger than that in the array of nanorings and nanoparticles. According to the results of finite-difference time-domain simulation, the excellent SERS performance of this array is ascribed to the high density of hot spots and enhanced electromagnetic field.

Identificación y mapeo de AFLPs ligados al gen de resistencia al PVX en Solanum commersonii

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Mónica Blanco

2005-01-01

Full Text Available Solanum commersonii es una especie silvestre de papa considerada como una fuente de genes de resistencia al PVX. Para identificar marcadores moleculares relacionados con los genes de resistencia a este virus, se realizó un análisis en el que se combinó la técnica de BSA con el uso de AFLPs. Del cruce de 2 padres heterocigotos y resistentes al PVX, provenientes de una F1, se obtuvo una F2. La población fue inoculada con el PVXMS y 30 días después mediante un ELISA, la progenie fue dividida en individuos infectados y no infectados con el PVXMS; a estos 2 grupos se les realizó un BSA. El ADN de los individuos resistentes fue mezclado aparte del ADN de los individuos susceptibles y con la ayuda de AFLPs se logró identificar 22 combinaciones de imprimadores que produjeron bandas específicas relacionadas con el carácter de resistencia al PVX. Las combinaciones de imprimadores seleccionadas fueron utilizadas para evaluar cada uno de los individuos de la F2 en forma independiente. Producto de este análisis se obtuvo 63 bandas polimórficas relacionadas al carácter de resistencia, cuya información fue introducida en el programa MAPRF6. Como resultado se obtuvo 4 grupos de ligamiento. Se encontró un RGA, obtenido en otro estudio que co-segrega (0 cM con el locus del gen de resistencia extrema (Rx y los AFLPs 42 y 39 que están rodeando el mismo locus a 22,6 cM o más. La información obtenida será básica para implementar programas de selección asistida por marcadores moleculares en el mejoramiento genético.

Quaternized chitosan/silver nanoparticles composite as a SERS substrate for detecting tricyclazole and Sudan I

Energy Technology Data Exchange (ETDEWEB)

Chen, Kaihang; Shen, Zuguang [State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640 (China); Luo, Jiwen, E-mail: holdit@126.com [State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640 (China); Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Wang, Xiaoying, E-mail: xyw@scut.edu.cn [State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640 (China); Sun, Runcang [State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640 (China); Institute of Biomass Chemistry and Technology, Beijing Forestry University, Beijing 100083 (China)

2015-10-01

Graphical abstract: - Highlights: • Synthesis optimization of Ag NPs with quaternized chitosan (QCS) was studied. • The size of Ag NPs was tuned by changing the DS and Mw of QCS. • QCS/Ag NPs exhibited much better SERS performance than Ag NPs without free QCS. • QCS/Ag NPs as SERS substrate detected tricyclazole in low concentration of 50 ppb. • QCS/Ag NPs as SERS substrate detected Sudan I with the detection limit of 10 ppm. - Abstract: There is an urgent need to develop a highly sensitive detection system for detecting trace amounts of food contaminants. In this study, optimal synthesis of silver nanoparticles (Ag NPs) with stable and narrow size distribution in the range of 15–25 nm was performed under microwave irradiation, using quaternized chitosan (QCS) as reducing and stabilizing agent. The results showed that the ratio of QCS to [Ag(NH{sub 3}){sub 2}]{sup +}, reaction temperature, irradiation time, the degree of substitution (DS) and molecular weight (Mw) of QCS had obvious effects on the formation, particle size and size distribution of Ag NPs. In addition, utilizing QCS/Ag NPs composite as SERS substrate, tricyclazole and Sudan I could be rapidly and sensitively detected with the limit of detection (LOD) as low as 50 ppb and 10 ppm, respectively. Compared with previously reported works, our detection system are of great stability and operability. The QCS was coated on the surface of Ag core, avoiding aggregation of Ag NPs and creating hot spots, in turn, providing superior amplification of SERS. Thus, it is believed that the QCS/Ag NPs composite could be considered as an ideal SERS-active substrate for detection of food contaminants.

Design of analog-type high-speed SerDes using digital components for optical chip-to-chip link

Science.gov (United States)

Sangirov, Jamshid; Nguyen, Nga T. H.; Ngo, Trong-Hieu; Im, Dong-min; Ukaegbu, Augustine I.; Lee, Tae-Woo; Cho, Mu Hee; Park, Hyo-Hoon

2010-02-01

An analog-type high-speed serializer/deserializer (SerDes) has been designed for optical links especially between CPU and memory. The circuit uses a system clock and its phases to multiplex data to the serial link which avoids the need for a PLL-based high frequency clock generation used in serializing parallel data as in conventional SerDes design. The multiplexed link combined with the de-serializing clock is used as a reference signal for de-serialization. The SerDes is being designed in a 0.13 μm Si-CMOS technology. The fabricated serializer has a core chip size of 360 x750 μm2. Power dissipation for the SerDes is 71.4 mW operating up to 6.5 Gbps.

Fabrication of chitosan-silver nanoparticle hybrid 3D porous structure as a SERS substrate for biomedical applications

Science.gov (United States)

Jung, Gyeong-Bok; Kim, Ji-Hye; Burm, Jin Sik; Park, Hun-Kuk

2013-05-01

We propose a simple, low-cost, large-area, and functional surface enhanced Raman scattering (SERS) substrate for biomedical applications. The SERS substrate with chitosan-silver nanoparticles (chitosan-Ag NPs) hybrid 3D porous structure was fabricated simply by a one-step method. The chitosan was used as a template for the Ag NPs deposition. SERS enhancement by the chitosan-Ag NPs substrate was experimentally verified using rhodamine B as an analyte. Thiolated single stranded DNA was also measured for atopic dermatitis genetic markers (chemokines CCL17) at a low concentration of 5 pM. We successfully designed a novel SERS substrate with silver nanoparticle hybridized 3D porous chitosan that has the potential to become a highly sensitive and selective tool for biomedical applications.

Hierarchical Ag mesostructures for single particle SERS substrate

Energy Technology Data Exchange (ETDEWEB)

Xu, Minwei, E-mail: xuminwei@xjtu.edu.cn; Zhang, Yin

2017-01-30

Highlights: • Hierarchical Ag mesostructures with the size of 250, 360 and 500 nm are synthesized via a seed-mediated approach. • The Ag mesostructures present the tailorable size and highly roughened surfaces. • The average enhancement factors for individual Ag mesostructures were estimated to be as high as 10{sup 6}. - Abstract: Hierarchical Ag mesostructures with highly rough surface morphology have been synthesized at room temperature through a simple seed-mediated approach. Electron microscopy characterizations indicate that the obtained Ag mesostructures exhibit a textured surface morphology with the flower-like architecture. Moreover, the particle size can be tailored easily in the range of 250–500 nm. For the growth process of the hierarchical Ag mesostructures, it is believed that the self-assembly mechanism is more reasonable rather than the epitaxial overgrowth of Ag seed. The oriented attachment of nanoparticles is revealed during the formation of Ag mesostructures. Single particle surface enhanced Raman spectra (sp-SERS) of crystal violet adsorbed on the hierarchical Ag mesostructures were measured. Results reveal that the hierarchical Ag mesostructures can be highly sensitive sp-SERS substrates with good reproducibility. The average enhancement factors for individual Ag mesostructures are estimated to be about 10{sup 6}.

Monitoreo radiológico ambiental debido al accidente nuclear de Fukushima

OpenAIRE

Osores, José; Jara, Raúl

2014-01-01

Debido al accidente de Fukushima (Japón), entre los años 2011 y 2012, se realizó el monitoreo radiológico ambiental con la finalidad de evaluar algún posible impacto en el medioambiente del Perú. Los resultados confirman que, por la posición geográfica de nuestro país, no se produjo ningún tipo de contaminación radiactiva que pueda ser de riesgo para la población. Because of the accident of Fukushima (Japan), between 2011 and 2012, we performed the environmental radiological monitoring in ...

Intracellular surface-enhanced Raman scattering (SERS) with thermally stable gold nanoflowers grown from Pt and Pd seeds

KAUST Repository

Song, Hyon Min

2013-01-01

SERS provides great sensitivity at low concentrations of analytes. SERS combined with near infrared (NIR)-resonant gold nanomaterials are important candidates for theranostic agents due to their combined extinction properties and sensing abilities stemming from the deep penetration of laser light in the NIR region. Here, highly branched gold nanoflowers (GNFs) grown from Pd and Pt seeds are prepared and their SERS properties are studied. The growth was performed at 80°C without stirring, and this high temperature growth method is assumed to provide great shape stability of sharp tips in GNFs. We found that seed size must be large enough (>30 nm in diameter) to induce the growth of those SERS-active and thermally stable GNFs. We also found that the addition of silver nitrate (AgNO3) is important to induce sharp tip growth and shape stability. Incubation with Hela cells indicates that GNFs are taken up and reside in the cytoplasm. SERS was observed in those cells incubated with 1,10-phenanthroline (Phen)-loaded GNFs. This journal is © 2013 The Royal Society of Chemistry.

Intracellular surface-enhanced Raman scattering (SERS) with thermally stable gold nanoflowers grown from Pt and Pd seeds.

Science.gov (United States)

Song, Hyon Min; Deng, Lin; Khashab, Niveen M

2013-05-21

SERS provides great sensitivity at low concentrations of analytes. SERS combined with near infrared (NIR)-resonant gold nanomaterials are important candidates for theranostic agents due to their combined extinction properties and sensing abilities stemming from the deep penetration of laser light in the NIR region. Here, highly branched gold nanoflowers (GNFs) grown from Pd and Pt seeds are prepared and their SERS properties are studied. The growth was performed at 80 °C without stirring, and this high temperature growth method is assumed to provide great shape stability of sharp tips in GNFs. We found that seed size must be large enough (>30 nm in diameter) to induce the growth of those SERS-active and thermally stable GNFs. We also found that the addition of silver nitrate (AgNO3) is important to induce sharp tip growth and shape stability. Incubation with Hela cells indicates that GNFs are taken up and reside in the cytoplasm. SERS was observed in those cells incubated with 1,10-phenanthroline (Phen)-loaded GNFs.

Highly sensitive and stable Ag@SiO2 nanocubes for label-free SERS-photoluminescence detection of biomolecules

Science.gov (United States)

Nguyen, Minh-Kha; Su, Wei-Nien; Chen, Ching-Hsiang; Rick, John; Hwang, Bing-Joe

2017-03-01

Surface-enhanced Raman scattering (SERS) and fluorescence microscopy are a widely used biological and chemical characterization techniques. However, the peak overlapping in multiplexed experiments and rapid photobleaching of fluorescent organic dyes is still the limitations. When compared to Ag nanocubes (NCs), higher SERS sensitivities can be obtained with thin shelled silica Ag@SiO2 NCs, in contrast metal-enhanced photoluminescence (MEPL) is only found with NCs that have thicker silica shells. A 'dual functionality' represented by the simultaneous strengthening of SERS and MEPL signals can be achieved by mixing Ag@SiO2 NCs, with a silica shell thickness of 1.5 nm and 4.4 nm. This approach allows both the Ag@SiO2 NCs SERS and MEPL sensitivities to be maintained at 90% after 12 weeks of storage. Based on the distinguished detection of creatinine and flavin adenine dinucleotide in the mixture, the integration of SERS and MEPL together on a stable single plasmonic nanoparticle platform offers an opportunity to enhance both biomarker detection sensitivity and specificity.

Glutamate Counteracts Dopamine/PKA Signaling via Dephosphorylation of DARPP-32 Ser-97 and Alteration of Its Cytonuclear Distribution*

Science.gov (United States)

Nishi, Akinori; Matamales, Miriam; Musante, Veronica; Valjent, Emmanuel; Kuroiwa, Mahomi; Kitahara, Yosuke; Rebholz, Heike; Greengard, Paul; Girault, Jean-Antoine; Nairn, Angus C.

2017-01-01

The interaction of glutamate and dopamine in the striatum is heavily dependent on signaling pathways that converge on the regulatory protein DARPP-32. The efficacy of dopamine/D1 receptor/PKA signaling is regulated by DARPP-32 phosphorylated at Thr-34 (the PKA site), a process that inhibits protein phosphatase 1 (PP1) and potentiates PKA action. Activation of dopamine/D1 receptor/PKA signaling also leads to dephosphorylation of DARPP-32 at Ser-97 (the CK2 site), leading to localization of phospho-Thr-34 DARPP-32 in the nucleus where it also inhibits PP1. In this study the role of glutamate in the regulation of DARPP-32 phosphorylation at four major sites was further investigated. Experiments using striatal slices revealed that glutamate decreased the phosphorylation states of DARPP-32 at Ser-97 as well as Thr-34, Thr-75, and Ser-130 by activating NMDA or AMPA receptors in both direct and indirect pathway striatal neurons. The effect of glutamate in decreasing Ser-97 phosphorylation was mediated by activation of PP2A. In vitro phosphatase assays indicated that the PP2A/PR72 heterotrimer complex was likely responsible for glutamate/Ca2+-regulated dephosphorylation of DARPP-32 at Ser-97. As a consequence of Ser-97 dephosphorylation, glutamate induced the nuclear localization in cultured striatal neurons of dephospho-Thr-34/dephospho-Ser-97 DARPP-32. It also reduced PKA-dependent DARPP-32 signaling in slices and in vivo. Taken together, the results suggest that by inducing dephosphorylation of DARPP-32 at Ser-97 and altering its cytonuclear distribution, glutamate may counteract dopamine/D1 receptor/PKA signaling at multiple cellular levels. PMID:27998980

Modelo de educación holística: Una propuesta para la formación del ser humano

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Gluyas Fitch, Rosa Isela

2015-09-01

Full Text Available Este ensayo se propone plantear una aproximación al Modelo de Educación Holística (MEH aplicado a la enseñanza de las artes, con el fin de lograr su incorporación formal en los modelos educativos desde una perspectiva cocurricular. Para lo anterior se realizó una investigación documental por medio de la selección, revisión y análisis de diversos autores sobre la concepción de la formación holística como eje del desarrollo del ser humano. Los resultados muestran que la visión integral de la persona y del mundo en el que ésta se desarrolla, orienta a las instituciones educativas en el diseño de un currículum holístico, con la incorporación de la enseñanza de las artes para que el estudiante identifique, analice, aborde, examine y viva con intensidad cada una de las relaciones existentes entre las esferas de la vida humana. Las conclusiones señalan que la educación que ha de ser impartida tiene que poseer una visión holística del estudiante para establecer una vinculación con otras esferas nunca o poco abordadas en los contextos de aprendizaje, y la formación artística tiene el potencial para desarrollar la dimensión sensible de la persona para recrear su interacción con el mundo en busca del bienestar de la humanidad.

SERS-Based Flavonoid Detection Using Ethylenediamine-β-Cyclodextrin as a Capturing Ligand

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Jae Min Choi

2017-01-01

Full Text Available Ethylenediamine-modified β-cyclodextrin (Et-β-CD was immobilized on aggregated silver nanoparticle (NP-embedded silica NPs (SiO2@Ag@Et-β-CD NPs for the effective detection of flavonoids. Silica NPs were used as the template for embedding silver NPs to create hot spots and enhance surface-enhanced Raman scattering (SERS signals. Et-β-CD was immobilized on Ag NPs to capture flavonoids via host-guest inclusion complex formation, as indicated by enhanced ultraviolet absorption spectra. The resulting SiO2@Ag@Et-β-CD NPs were used as the SERS substrate for detecting flavonoids, such as hesperetin, naringenin, quercetin, and luteolin. In particular, luteolin was detected more strongly in the linear range 10−7 to 10−3 M than various organic molecules, namely ethylene glycol, β-estradiol, isopropyl alcohol, naphthalene, and toluene. In addition, the SERS signal for luteolin captured by the SiO2@Ag@Et-β-CD NPs remained even after repeated washing. These results indicated that the SiO2@Ag@Et-β-CD NPs can be used as a rapid, sensitive, and selective sensor for flavonoids.

SERS-Fluorescence Dual-Mode pH-Sensing Method Based on Janus Microparticles.

Science.gov (United States)

Yue, Shuai; Sun, Xiaoting; Wang, Ning; Wang, Yaning; Wang, Yue; Xu, Zhangrun; Chen, Mingli; Wang, Jianhua

2017-11-15

A surface-enhanced Raman scattering (SERS)-fluorescence dual-mode pH-sensing method based on Janus microgels was developed, which combined the advantages of high specificity offered by SERS and fast imaging afforded by fluorescence. Dual-mode probes, pH-dependent 4-mercaptobenzoic acid, and carbon dots were individually encapsulated in the independent hemispheres of Janus microparticles fabricated via a centrifugal microfluidic chip. On the basis of the obvious volumetric change of hydrogels in different pHs, the Janus microparticles were successfully applied for sensitive and reliable pH measurement from 1.0 to 8.0, and the two hemispheres showed no obvious interference. The proposed method addressed the limitation that sole use of the SERS-based pH sensing usually failed in strong acidic media. The gastric juice pH and extracellular pH change were measured separately in vitro using the Janus microparticles, which confirmed the validity of microgels for pH sensing. The microparticles exhibited good stability, reversibility, biocompatibility, and ideal semipermeability for avoiding protein contamination, and they have the potential to be implantable sensors to continuously monitor pH in vivo.

Enfermedad periodontal: ¿es factor de riesgo para parto pretérmino, bajo peso al nacer o preeclampsia?

Directory of Open Access Journals (Sweden)

José Luis Castaldi

2006-04-01

Full Text Available OBJETIVOS: Evaluar si la enfermedad periodontal (EP constituye un factor de riesgo de parto pretérmino, bajo peso al nacer o preeclampsia y si hay alguna relación entre las formas clínicas de la EP y los resultados obstétricos mencionados. MÉTODOS: Estudio analítico, transversal y prospectivo de todas las mujeres que tuvieron su parto en el Hospital Dr. José Penna, de la ciudad de Bahía Blanca, Argentina, entre el 1.º de febrero y el 18 de julio de 2003 y entre el 1.º de marzo y el 31 de mayo de 2004. A las mujeres que cumplieron los criterios de inclusión (ser mayor de 18 años, tener al menos 18 dientes, no ser diabética y que los hijos hubieran sobrevivido al parto se les practicó un examen odontológico en busca de hemorragia al sondaje, movilidad dentaria o inflamación gingival y se realizaron mediciones clínicas de la pérdida de inserción. Se calcularon las razones de posibilidades (odds ratios, RP con sus intervalos de confianza del 95% (IC95% y se ajustaron los resultados por las variables "ser fumadora" y "tener anemia". RESULTADOS: Se registraron 2 003 nacimientos, correspondientes a 1 982 partos. Se excluyeron 420 (21,2% mujeres por no cumplir los criterios de inclusión o por no poder realizárseles el diagnóstico odontológico previsto. De las 1 562 mujeres evaluadas, 809 (51,8% presentaban alguna de las afecciones buscadas; de ellas, 274 (17,5% padecían EP grave y 535 (34,3% tenían gingivitis. En total, 149 (9,5% partos fueron pretérmino, en 161 (10,3% nacieron niños con bajo peso y en 157 (10,0% se presentaron casos de preeclampsia. No se observó asociación alguna entre la EP y el parto pretérmino (RP = 1,06; IC95%: 0,74 a 1,50, el bajo peso al nacer (RP = 1,05; IC95%: 0,74 a 1,47 y la preeclampsia (RP = 0,99; IC95%: 0,70 a 1,40. El riesgo de dar a luz un niño con bajo peso al nacer en el subgrupo de fumadoras de más de 10 cigarrillos diarios fue mayor en las que tenían enfermedad periodontal grave que

Complete urinary tract infection (UTI) diagnosis and antibiogram using surface enhanced Raman spectroscopy (SERS)

Science.gov (United States)

Hadjigeorgiou, Katerina; Kastanos, Evdokia; Kyriakides, Alexandros; Pitris, Costas

2012-03-01

There are three stages to a complete UTI diagnosis: (1) identification of a urine sample as positive/negative for an infection, (2) identification of the responsible bacterium, (3) antibiogram to determine the antibiotic to which the bacteria are most sensitive to. Using conventional methods, all three stages require bacterial cultures in order to provide results. This long delay in diagnosis causes a rise in ineffective treatments, chronic infections, health care costs and antibiotic resistance. In this work, SERS is used to identify a sample as positive/negative for a UTI as well as to obtain an antibiogram against different antibiotics. SERS spectra of serial dilutions of E. coli bacteria mixed with silver nanoparticles, showed a linear correlation between spectral intensity and concentration. For antibiotic sensitivity testing, SERS spectra of three species of gram negative bacteria were collected four hours after exposure to the antibiotics ciprofloxacin and amoxicillin. Spectral analysis revealed clear separation between bacterial samples exposed to antibiotics to which they were sensitive and samples exposed to antibiotics to which they were resistant. With the enhancement provided by SERS, the technique can be applied directly to urine samples leading to the development of a new, rapid method for UTI diagnosis and antibiogram.

Condiciones de favorabilidad al maternaje y violencia materna

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Mauricio Hernando Bedoya

2010-01-01

como maltratadoras, y en sus hijos e hijas maltratados, el significado dado a su vínculo afectivo. Método: fenomenológico-hermenéutico del enfoque cualitativo con muestra multinivel. Técnicas de Producción de Información: entrevistas en profundidad con madres, grupos focales con sus hijos e hijas y con madres y padres de tres instituciones educativas. Conclusiones: las madres explican la violencia hacia sus hijos e hijas acudiendo a una cadena vincular generacional con su propia madre; las condiciones de favorabilidad al maternaje adversas predicen tal violencia; no todo niño o niña violentado será padre violento o madre violenta y, finalmente, postulamos que existe una tipología de madre violenta.

Ethik als transdisziplinärer Ansatz für Geschlechterforschung

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Regina Harzer

2007-07-01

Full Text Available „Ethik“ hat Hochkonjunktur, theoretisch und praktisch. Tierethik, Medizin- und Bioethik, Rechtsethik und Neuroethik, um nur einige aktuelle Auseinandersetzungen mit rekonstruierten und modernisierten Moralphilosophien zu nennen. „Ethikräte“ schießen wie Pilze aus dem Boden: Im Bereich des Sports ebenso wie im Rahmen kulturell-religiöser Gegenwartsdiskurse. Von daher verwundert es nicht, dass auch die Kategorie „Geschlecht“ ethischen Überprüfungen unterzogen wird. Im vorliegenden Sammelband werden Grundanliegen der feministischen Ethik aber nicht nur anhand feministischer Einzelbeschreibungen untersucht, sondern in den Kontext von unterschiedlichen Disziplinanforderungen gestellt. Deshalb präsentiert sich das Buch auch als Gang durch die Wissenschaften selbst.

Intracellular surface-enhanced Raman scattering (SERS) with thermally stable gold nanoflowers grown from Pt and Pd seeds

KAUST Repository

Song, Hyon Min; Deng, Lin; Khashab, Niveen M.

2013-01-01

SERS provides great sensitivity at low concentrations of analytes. SERS combined with near infrared (NIR)-resonant gold nanomaterials are important candidates for theranostic agents due to their combined extinction properties and sensing abilities

A FILOSOFIA DOS JOVENS SOBRE O SER JOVEM: UMA PESQUISA SOCIOPOÉTICA

OpenAIRE

Carneiro, Cristianne Teixeira; Universidade Federal do Piauí - UFPI; Bezerra, Maria Augusta Rocha; Universidade Federal do Piauí - UFPI; Adad, Shara Jane Holanda Costa; Universidade Federal do Piauí - UFPI; Santos, Kathia Raquel Piauilino; Universidade Federal do Piauí - UFPI; Carvalho, Francimeiry Santos; Universidade Federal do Piauí - UFPI

2015-01-01

Objetivou-se conhecer os modos de pensar dos jovens de um curso técnico em enfermagem de um colégio técnico federal sobre “o que é ser jovem?”. A pesquisa se insere no paradigma qualitativo de investigação utilizando a Sociopoética, foi realizada com 11 jovens que cursavam o ensino médio concomitante ao técnico em enfermagem em 2013. Os jovens problematizaram a dimensão do tempo de espera para o mundo adulto, mostrando que não há um único modo de ser jovem e nem de se tornar adulto, pois para...

Surface-enhanced vibrational spectroscopy of B vitamins: what is the effect of SERS-active metals used?

Science.gov (United States)

Kokaislová, A; Matějka, P

2012-05-01

Surface-enhanced Raman scattering (SERS) spectroscopy and surface-enhanced infrared absorption (SEIRA) spectroscopy are analytical tools suitable for the detection of small amounts of various analytes adsorbed on metal surfaces. During recent years, these two spectroscopic methods have become increasingly important in the investigation of adsorption of biomolecules and pharmaceuticals on nanostructured metal surfaces. In this work, the adsorption of B-group vitamins pyridoxine, nicotinic acid, folic acid and riboflavin at electrochemically prepared gold and silver substrates was investigated using Fourier transform SERS spectroscopy at an excitation wavelength of 1,064 nm. Gold and silver substrates were prepared by cathodic reduction on massive platinum targets. In the case of gold substrates, oxidation-reduction cycles were applied to increase the enhancement factor of the gold surface. The SERS spectra of riboflavin, nicotinic acid, folic acid and pyridoxine adsorbed on silver substrates differ significantly from SERS spectra of these B-group vitamins adsorbed on gold substrates. The analysis of near-infrared-excited SERS spectra reveals that each of B-group vitamin investigated interacts with the gold surface via a different mechanism of adsorption to that with the silver surface. In the case of riboflavin adsorbed on silver substrate, the interpretation of surface-enhanced infrared absorption (SEIRA) spectra was also helpful in investigation of the adsorption mechanism.

Functional paper-based SERS substrate for rapid and sensitive detection of Sudan dyes in herbal medicine

Science.gov (United States)

Wu, Mianmian; Li, Pan; Zhu, Qingxia; Wu, Meiran; Li, Hao; Lu, Feng

2018-05-01

There has been an increasing demand for rapid and sensitive techniques for the identification of Sudan compounds that emerged as the most often illegally added fat-soluble dyes in herbal medicine. In this report, we have designed and fabricated a functionalized filter paper consisting of gold nanorods (GNRs) and mono-6-thio-cyclodextrin (HS-β-CD) as a surface-enhanced Raman spectroscopy (SERS) substrate, in which the GNR provides sufficient SERS enhancement, and the HS-β-CD with strong chemical affinity toward GNR provides the inclusion compound to capture hydrophobic molecules. Moreover, the CD-GNR were uniformly assembled on filter paper cellulose through the electrostatic adsorption and hydrogen bond, so that the CD-GNR paper-based SERS substrate (CD-GNR-paper) demonstrated higher sensitivity for the determination of Sudan III (0.1 μM) and Sudan IV (0.5 μM) than GNRs paper-based SERS substrate (GNR-paper), with high stability after the storage in the open air for 90 days. Importantly, CD-GNR-paper can effectively collect the Sudan dyes from illegally adulterated onto samples of Resina Draconis with a simple operation, further open up new exciting opportunity for SERS detection of more compounds illegally added with high sensitivity and fast signal responses.

Porous Au-Ag Nanospheres with High-Density and Highly Accessible Hotspots for SERS Analysis.

Science.gov (United States)

Liu, Kai; Bai, Yaocai; Zhang, Lei; Yang, Zhongbo; Fan, Qikui; Zheng, Haoquan; Yin, Yadong; Gao, Chuanbo

2016-06-08

Colloidal plasmonic metal nanoparticles have enabled surface-enhanced Raman scattering (SERS) for a variety of analytical applications. While great efforts have been made to create hotspots for amplifying Raman signals, it remains a great challenge to ensure their high density and accessibility for improved sensitivity of the analysis. Here we report a dealloying process for the fabrication of porous Au-Ag alloy nanoparticles containing abundant inherent hotspots, which were encased in ultrathin hollow silica shells so that the need of conventional organic capping ligands for stabilization is eliminated, producing colloidal plasmonic nanoparticles with clean surface and thus high accessibility of the hotspots. As a result, these novel nanostructures show excellent SERS activity with an enhancement factor of ∼1.3 × 10(7) on a single particle basis (off-resonant condition), promising high applicability in many SERS-based analytical and biomedical applications.

Non-labeling multiplex surface enhanced Raman scattering (SERS) detection of volatile organic compounds (VOCs)

DEFF Research Database (Denmark)

Wong, Chi Lok; Dinish, U. S.; Schmidt, Michael Stenbæk

2014-01-01

chemical sensing layer for the enrichment of gas molecules on sensor surface. The leaning nano-pillar substrate also showed highly reproducible SERS signal in cyclic VOCs detection, which can reduce the detection cost in practical applications. Further, multiplex SERS detection on different combination...... device for multiplex, specific and highly sensitive detection of complex VOCs samples that can find potential applications in exhaled breath analysis, hazardous gas analysis, homeland security and environmental monitoring....

Ser mujer en el barrio : análisis de significados de ser mujer para las adultas mayores de los barrios Pañuelito, Delicias del Carmen y Unicerros, barrios populares de la localidad de Usaquén

OpenAIRE

Baracaldo Silva, Flor del Pilar

2017-01-01

Este estudio de tipo etnográfico busca reflexionar a partir de las historias de vida de un grupo de mujeres mayores, sobre la construcción de significados de ser mujer en el contexto de los barrios populares de la localidad de Usaquén. Sus narrativas se tejen alrededor de las tensiones de lo que implica el progreso en la ciudad en situación de migración y marginalidad, y a su vez en lo que esta búsqueda de salir adelante, o ser alguien en la vida. Confronta los significados de ser una mujer b...

Comentario al libro “Creación, Arte y Psiquis”

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Fernando Sánchez Torres

2004-06-01

Full Text Available

La Junta Directiva de la Academia Nacional de Medicina ha tenido a bien encomendarme el comentario de rigor del libro Creación, Arte y Psiquis que nos acaba de presentar el académico Guillermo Sánchez Medina. Para ello se me han asignado diez minutos. Dado que el libro es de aquellos de tomo y lomo, vale decir que es denso de contenido y además extenso (445 páginas, con la venia del señor Presidente voy a exceder en algunos minutos el límite establecido.

Antes de entrar en materia debo señalar, además, que no soy docto en los asuntos de la psique, que es, como ya sabemos, de lo que trata el libro. Sin embargo, acepté el encargo en virtud del aprecio y admiración que me merece su autor. Confío en que él y ustedes sepan perdonar mi atrevimiento y mis flaquezas.

El doctor Guillermo Sánchez Medina, reconocido psicoanalista e intelectual de trayectoria, pone a circular ahora una nueva obra suya, esta vez para explorar y diseccionar, sirviéndose del psicoanálisis aplicado, nada más ni nada menos que el mecanismo de sublimación que conduce a la creación artística. Lo que pretende el autor es poner al descubierto y luego comentar a su criterio el origen de lo estético y lo bello, en particular en los campos de la pintura y la literatura. Gracias a su amplia cultura y a su sagacidad psicoanalítica, de la pretensión sale airoso pues logra lo buscado.

Equivocadamente su libro no es todo de su autoría. No entiendo bien por qué ni para qué solicitó la colaboración de pares académicos suyos, y aun de personas que no lo son, si no la necesitaba. Su desbordada imaginación y el conocimiento de los temas que trata eran prenda de garantía para escribirlo en solitario, sin pedir el concurso de nadie. Para ser franco, quienes fuimos invitados a escribir algunas páginas servimos solo de distractores de la parte sustancial del libro, que es, precisamente, la escrita por el autor titular. Se aumentan las páginas, es

Glutamate Counteracts Dopamine/PKA Signaling via Dephosphorylation of DARPP-32 Ser-97 and Alteration of Its Cytonuclear Distribution.

Science.gov (United States)

Nishi, Akinori; Matamales, Miriam; Musante, Veronica; Valjent, Emmanuel; Kuroiwa, Mahomi; Kitahara, Yosuke; Rebholz, Heike; Greengard, Paul; Girault, Jean-Antoine; Nairn, Angus C

2017-01-27

The interaction of glutamate and dopamine in the striatum is heavily dependent on signaling pathways that converge on the regulatory protein DARPP-32. The efficacy of dopamine/D1 receptor/PKA signaling is regulated by DARPP-32 phosphorylated at Thr-34 (the PKA site), a process that inhibits protein phosphatase 1 (PP1) and potentiates PKA action. Activation of dopamine/D1 receptor/PKA signaling also leads to dephosphorylation of DARPP-32 at Ser-97 (the CK2 site), leading to localization of phospho-Thr-34 DARPP-32 in the nucleus where it also inhibits PP1. In this study the role of glutamate in the regulation of DARPP-32 phosphorylation at four major sites was further investigated. Experiments using striatal slices revealed that glutamate decreased the phosphorylation states of DARPP-32 at Ser-97 as well as Thr-34, Thr-75, and Ser-130 by activating NMDA or AMPA receptors in both direct and indirect pathway striatal neurons. The effect of glutamate in decreasing Ser-97 phosphorylation was mediated by activation of PP2A. In vitro phosphatase assays indicated that the PP2A/PR72 heterotrimer complex was likely responsible for glutamate/Ca 2+ -regulated dephosphorylation of DARPP-32 at Ser-97. As a consequence of Ser-97 dephosphorylation, glutamate induced the nuclear localization in cultured striatal neurons of dephospho-Thr-34/dephospho-Ser-97 DARPP-32. It also reduced PKA-dependent DARPP-32 signaling in slices and in vivo Taken together, the results suggest that by inducing dephosphorylation of DARPP-32 at Ser-97 and altering its cytonuclear distribution, glutamate may counteract dopamine/D1 receptor/PKA signaling at multiple cellular levels. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Reproducible and recyclable SERS substrates: Flower-like Ag structures with concave surfaces formed by electrodeposition

Science.gov (United States)

Bian, Juncao; Shu, Shiwei; Li, Jianfu; Huang, Chao; Li, Yang Yang; Zhang, Rui-Qin

2015-04-01

Direct synthesis of three-dimensional Ag structures on solid substrates for the purposes of producing reproducible and recyclable surface-enhanced Raman scattering (SERS) applications remains challenging. In this work, flower-like Ag structures with concave surfaces (FACS) were successfully electrodeposited onto ITO glass using the double-potentiostatic method. The FACS, with an enhancement factor of the order of 108, exhibited a SERS signal intensity 3.3 times stronger than that measured from Ag nanostructures without concave surfaces. A cleaning procedure involving lengthy immersion of the sample in ethanol and KNO3 was proposed to recycle the substrate and confirmed by using rhodamine 6G, adenine, and 4-aminothiophenol as target molecules. The findings can help to advance the practical applications of Ag nanostructure-based SERS substrates.

Comentario al libro "Del Macroscopio al Microscopio- Historia de la Medicina Científica"

Directory of Open Access Journals (Sweden)

Efraim Otero Ruiz

2002-04-01

Full Text Available

Del Dr. Alberto Gómez Gutierrez - (Bogotá Febrero 14 de 2002.

Si el tercer milenio se inicia con los portentos de la biofísica, la genómica, la microelectrónica y la biología molecular, el segundo finalizó con los horizontes que le habían abierto Newton, Galileo y Leibnitz en el siglo XVII cuyas bases, después ampliadas por Planck, Rutherford y Einstein, permitieron abrir la novísima instrumentación de los siglos XIX y XX. Ello no sólo afectó las ciencias físicas y químicas, teóricas o experimentales: también la medicina pasó, de ser el arte observacional y empírico que venía desde los sumerios y desde Hipócrates, a convertirse más y más en una ciencia, en que las mediciones y las comprobaciones estadísticas o las evidencias dominan cada vez más las avenidas del conocimiento. A los precursores de ese surgimiento milenario de una medicina mensurable y experimental es a quienes dedica Alberto Gómez Gutiérrez su libro “Del macroscopio al microscopio- Historia de la medicina científica” que ha presentado como trabajo de ingreso de Miembro Asociado a la Academia Nacional de Medicina y que, después de ser aprobado casi que por aclamación, tenemos el agrado y el honor de comentar esta noche.

La magna obra, que veremos publicada e ilustrada próximamente, consta de 4 grandes partes o divisiones, comenzadas por una introducción –como parte Ia- y terminadas por un epílogo y por 93 referencias bibliográficas, bien leídas y analizadas por el autor.

Esas divisiones están a su vez formadas por capítulos o secciones, encabezados por letras. La segunda, titulada “Antecedentes de la medicina experimental” va desde lo que el autor llama “las primeras luces” hasta el “nacimiento de la ciencia”, en capítulos de la letra A hasta la F. Pero no es estrictamente una historia de la ciencia o de la medicina, como pudiera esperarse.

Son m

Plasmonic Hotspots in Air: An Omnidirectional Three-Dimensional Platform for Stand-Off In-Air SERS Sensing of Airborne Species.

Science.gov (United States)

Phan-Quang, Gia Chuong; Lee, Hiang Kwee; Teng, Hao Wen; Koh, Charlynn Sher Lin; Yim, Barnabas Qinwei; Tan, Eddie Khay Ming; Tok, Wee Lee; Phang, In Yee; Ling, Xing Yi

2018-05-14

Molecular-level airborne sensing is critical for early prevention of disasters, diseases, and terrorism. Currently, most 2D surface-enhanced Raman spectroscopy (SERS) substrates used for air sensing have only one functional surface and exhibit poor SERS-active depth. "Aerosolized plasmonic colloidosomes" (APCs) are introduced as airborne plasmonic hotspots for direct in-air SERS measurements. APCs function as a macroscale 3D and omnidirectional plasmonic cloud that receives laser irradiation and emits signals in all directions. Importantly, it brings about an effective plasmonic hotspot in a length scale of approximately 2.3 cm, which affords 100-fold higher tolerance to laser misalignment along the z-axis compared with 2D SERS substrates. APCs exhibit an extraordinary omnidirectional property and demonstrate consistent SERS performance that is independent of the laser and analyte introductory pathway. Furthermore, the first in-air SERS detection is demonstrated in stand-off conditions at a distance of 200 cm, highlighting the applicability of 3D omnidirectional plasmonic clouds for remote airborne sensing in threatening or inaccessible areas. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Metal-interconnection-free integration of InGaN/GaN light emitting diodes with AlGaN/GaN high electron mobility transistors

Energy Technology Data Exchange (ETDEWEB)

Liu, Chao; Cai, Yuefei; Liu, Zhaojun; Ma, Jun; Lau, Kei May, E-mail: eekmlau@ust.hk [Photonics Technology Center, Department of Electronic and Computer Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

2015-05-04

We report a metal-interconnection-free integration scheme for InGaN/GaN light emitting diodes (LEDs) and AlGaN/GaN high electron mobility transistors (HEMTs) by combining selective epi removal (SER) and selective epitaxial growth (SEG) techniques. SER of HEMT epi was carried out first to expose the bottom unintentionally doped GaN buffer and the sidewall GaN channel. A LED structure was regrown in the SER region with the bottom n-type GaN layer (n-electrode of the LED) connected to the HEMTs laterally, enabling monolithic integration of the HEMTs and LEDs (HEMT-LED) without metal-interconnection. In addition to saving substrate real estate, minimal interface resistance between the regrown n-type GaN and the HEMT channel is a significant improvement over metal-interconnection. Furthermore, excellent off-state leakage characteristics of the driving transistor can also be guaranteed in such an integration scheme.

Metal-interconnection-free integration of InGaN/GaN light emitting diodes with AlGaN/GaN high electron mobility transistors

International Nuclear Information System (INIS)

Liu, Chao; Cai, Yuefei; Liu, Zhaojun; Ma, Jun; Lau, Kei May

2015-01-01

We report a metal-interconnection-free integration scheme for InGaN/GaN light emitting diodes (LEDs) and AlGaN/GaN high electron mobility transistors (HEMTs) by combining selective epi removal (SER) and selective epitaxial growth (SEG) techniques. SER of HEMT epi was carried out first to expose the bottom unintentionally doped GaN buffer and the sidewall GaN channel. A LED structure was regrown in the SER region with the bottom n-type GaN layer (n-electrode of the LED) connected to the HEMTs laterally, enabling monolithic integration of the HEMTs and LEDs (HEMT-LED) without metal-interconnection. In addition to saving substrate real estate, minimal interface resistance between the regrown n-type GaN and the HEMT channel is a significant improvement over metal-interconnection. Furthermore, excellent off-state leakage characteristics of the driving transistor can also be guaranteed in such an integration scheme

Porous Silicon Covered with Silver Nanoparticles as Surface-Enhanced Raman Scattering (SERS) Substrate for Ultra-Low Concentration Detection.

Science.gov (United States)

Kosović, Marin; Balarin, Maja; Ivanda, Mile; Đerek, Vedran; Marciuš, Marijan; Ristić, Mira; Gamulin, Ozren

2015-12-01

Microporous and macro-mesoporous silicon templates for surface-enhanced Raman scattering (SERS) substrates were produced by anodization of low doped p-type silicon wafers. By immersion plating in AgNO3, the templates were covered with silver metallic film consisting of different silver nanostructures. Scanning electron microscopy (SEM) micrographs of these SERS substrates showed diverse morphology with significant difference in an average size and size distribution of silver nanoparticles. Ultraviolet-visible-near-infrared (UV-Vis-NIR) reflection spectroscopy showed plasmonic absorption at 398 and 469 nm, which is in accordance with the SEM findings. The activity of the SERS substrates was tested using rhodamine 6G (R6G) dye molecules and 514.5 nm laser excitation. Contrary to the microporous silicon template, the SERS substrate prepared from macro-mesoporous silicon template showed significantly broader size distribution of irregular silver nanoparticles as well as localized surface plasmon resonance closer to excitation laser wavelength. Such silver morphology has high SERS sensitivity that enables ultralow concentration detection of R6G dye molecules up to 10(-15) M. To our knowledge, this is the lowest concentration detected of R6G dye molecules on porous silicon-based SERS substrates, which might even indicate possible single molecule detection.

[Size dependent SERS activity of gold nanoparticles studied by 3D-FDTD simulation].

Science.gov (United States)

Li, Li-mei; Fang, Ping-ping; Yang, Zhi-lin; Huang, Wen-da; Wu, De-yin; Ren, Bin; Tian, Zhong-qun

2009-05-01

By synthesizing Au nanoparticles with the controllable size from about 16 to 160 nm and measuring their SERS activity, the authors found that Au nanoparticles film with a size in the range of 120-135 nm showed the highest SERS activity with the 632.8 nm excitation, which is different from previous experimental results and theoretical predictions. The three dimensional finite difference time domain (3D-FDTD)method was employed to simulate the size dependent SERS activity. At the 632.8 nm excitation, the particles with a size of 110 nm shows the highest enhancement under coupling condition and presents an enhancement as high as 10(9) at the hot site. If the enhancement is averaged over the whole surface, the enhancement can still be as high as 10(7), in good agreement with our experimental data. For Au nanoparticles with a larger size such as 220 nm, the multipolar effect leads to the appearance of the second maximum enhancement with the increase in particles size. The averaged enhancement for the excitation line of 325 nm is only 10(2).

Therapeutic drug monitoring of flucytosine in serum using a SERS-active membrane system

Science.gov (United States)

Berger, Adam G.; White, Ian M.

2017-02-01

A need exists for near real-time therapeutic drug monitoring (TDM), in particular for antibiotics and antifungals in patient samples at the point-of-care. To truly fit the point-of-care need, techniques must be rapid and easy to use. Here we report a membrane system utilizing inkjet-fabricated surface enhanced Raman spectroscopy (SERS) sensors that allows sensitive and specific analysis despite the elimination of sophisticated chromatography equipment, expensive analytical instruments, and other systems relegated to the central lab. We utilize inkjet-fabricated paper SERS sensors as substrates for 5FC detection; the use of paper-based SERS substrates leverages the natural wicking ability and filtering properties of microporous membranes. We investigate the use of microporous membranes in the vertical flow assay to allow separation of the flucytosine from whole blood. The passive vertical flow assay serves as a valuable method for physical separation of target analytes from complex biological matrices. This work further establishes a platform for easy, sensitive, and specific TDM of 5FC from whole blood.

Synthesis and characterization of silver colloidal nanoparticles with different coatings for SERS application

International Nuclear Information System (INIS)

Mikac, L.; Ivanda, M.; Gotić, M.; Mihelj, T.; Horvat, L.

2014-01-01

Silver colloids were produced by chemical reduction of silver salt (silver nitrate, AgNO 3 ) solution. As reducing agents, trisodium citrate, sodium borohydride, ascorbic acid, polyvinylpyrrolidone, and glucose were used. The colloids were characterized by UV–Vis, DLS, zeta potential measurements, and SEM. The colloids were stabilized with negative groups or large molecules attached to their surface. The surface-enhanced Raman scattering (SERS) effect of stabilized nanoparticles was measured by using pyridine and rhodamine 6G molecules as analytes and NaNO 3 , KCl, and KBr at different concentrations as aggregating agents. The best Raman signal enhancement was achieved using silver nanoparticles of 40 nm size reduced and stabilized with citrate. The SERS signal of analyte molecules was further enhanced with the addition of sodium borohydride as an alternative aggregating agent. The borohydride had the strongest impact on the SERS effect of the colloid consistent of large (0.5 µm) silver nanoparticles stabilized with aminodextran. The mixture colloid-borohydride-pyridine was stable for hours. The mechanism of borohydride in the colloids is discussed

Synthesis and characterization of silver colloidal nanoparticles with different coatings for SERS application

Energy Technology Data Exchange (ETDEWEB)

Mikac, L.; Ivanda, M., E-mail: ivanda@irb.hr [Ruđer Bošković Institute, Laboratory for Molecular Physics (Croatia); Gotić, M. [Ruđer Bošković Institute, Laboratory for Synthesis of New Materials (Croatia); Mihelj, T. [Ruđer Bošković Institute, Laboratory for Synthesis and Processes of Self-assembling of Organic Molecules (Croatia); Horvat, L. [Ruđer Bošković Institute, Laboratory for Electron Microscopy (Croatia)

2014-12-15

Silver colloids were produced by chemical reduction of silver salt (silver nitrate, AgNO{sub 3}) solution. As reducing agents, trisodium citrate, sodium borohydride, ascorbic acid, polyvinylpyrrolidone, and glucose were used. The colloids were characterized by UV–Vis, DLS, zeta potential measurements, and SEM. The colloids were stabilized with negative groups or large molecules attached to their surface. The surface-enhanced Raman scattering (SERS) effect of stabilized nanoparticles was measured by using pyridine and rhodamine 6G molecules as analytes and NaNO{sub 3}, KCl, and KBr at different concentrations as aggregating agents. The best Raman signal enhancement was achieved using silver nanoparticles of 40 nm size reduced and stabilized with citrate. The SERS signal of analyte molecules was further enhanced with the addition of sodium borohydride as an alternative aggregating agent. The borohydride had the strongest impact on the SERS effect of the colloid consistent of large (0.5 µm) silver nanoparticles stabilized with aminodextran. The mixture colloid-borohydride-pyridine was stable for hours. The mechanism of borohydride in the colloids is discussed.

Synthesis of silver nanocubes as a SERS substrate for the determination of pesticide paraoxon and thiram

Science.gov (United States)

Wang, Bin; Zhang, Li; Zhou, Xia

2014-03-01

The silver cube-like nanostructure with uniform size and high yield have been synthesized through the rapid sulfide-mediated polyol method. The morphology, structure and optical properties of the as-prepared silver nanocubes were characterized by UV-Visible spectroscopy, field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). The Surface-Enhanced Raman Scattering (SERS) performance of the as-prepared Ag nanocubes was characterized by crystal violet (CV) as the probe molecules. Furthermore, the low levels of thiram and pesticide paraoxon can be detected by the SERS technique, which shows that the silver nanocubes as a SERS substrate have excellent sensitivity and reproducibility.

SERS Substrates by the Assembly of Silver Nano cubes: High-Throughput and Enhancement Reliability Considerations

International Nuclear Information System (INIS)

Rabin, O.; Lee, S.Y.; Rabin, O.

2012-01-01

Small clusters of nanoparticles are ideal substrates for SERS measurements, but the SERS signal enhancement by a particular cluster is strongly dependent on its structural characteristics and the measurement conditions. Two methods for high-throughput assembly of silver nano cubes into small clusters at predetermined locations on a substrate are presented. These fabrication techniques make it possible to study both the structure and the plasmonic properties of hundreds of nanoparticle clusters. The variations in SERS enhancement factors from cluster to cluster were analyzed and correlated with cluster size and configuration, and laser frequency and polarization. Using Raman instruments with 633 nm and 785 nm lasers and linear clusters of nano cubes, an increase in the reproducibility of the enhancement and an increase in the average enhancement values were achieved by increasing the number of nano cubes in the cluster, up to 4 nano cubes per cluster. By examining the effect of cluster configuration, it is shown that linear clusters with nano cubes attached in a face-to-face configuration are not as effective SERS substrates as linear clusters in which nano cubes are attached along an edge

Quantitative SERS detection of low-concentration aromatic polychlorinated biphenyl-77 and 2,4,6-trinitrotoluene.

Science.gov (United States)

Bao, Zhi Yong; Liu, Xin; Chen, Y; Wu, Yucheng; Chan, Helen L W; Dai, Jiyan; Lei, Dang Yuan

2014-09-15

This paper reports a simple label-free high-sensitive method for detecting low-concentration persistent organic pollutants and explosive materials. The proposed method combines surface-enhanced Raman spectroscopy (SERS) and magnetomotive enrichment of the target molecules on the surface of Ag nanoparticles (NPs). This structure can be achieved through self-assembling integration of Ag NPs with ferromagnetic Fe3O4 microspheres, forming a hybrid SERS nanoprobe with both optical and magnetic properties. Moreover, the magnetic response of ferromagnetic Fe3O4 microspheres can be used to dynamically modulate the optical property of Ag NPs through controlling their geometric arrangement on the substrate by applying an external magnetic field. It is also demonstrated from the full-wave numerical simulation results that the maximum electromagnetic field enhancement can be greatly increased by shortening the distance of neighboring Ag NPs and therefore resulting in an improved SERS detecting limit. More importantly, by using the prepared substrate, the SERS signals from organic pollution substances, i.e. aromatic polychlorinated biphenyl-77 and 2,4,6-trinitrotoluene, were quantitatively analyzed. Copyright © 2014 Elsevier B.V. All rights reserved.

A SERS protocol as a potential tool to access 6-mercaptopurine release accelerated by glutathione-S-transferase.

Science.gov (United States)

Wang, Ying; Sun, Jie; Yang, Qingran; Lu, Wenbo; Li, Yan; Dong, Jian; Qian, Weiping

2015-11-21

The developed method for monitoring GST, an important drug metabolic enzyme, could greatly facilitate researches on relative biological fields. In this work, we have developed a SERS technique to monitor the absorbance behaviour of 6-mercaptopurine (6-MP) and its glutathione-S-transferase (GST)-accelerated glutathione (GSH)-triggered release behaviour on the surface of gold nanoflowers (GNFs), using the GNFs as excellent SERS substrates. The SERS signal was used as an indicator of absorbance or release of 6-MP on the gold surface. We found that GST can accelerate GSH-triggered release behaviour of 6-MP from the gold surface. We speculated that GST catalyzes nucleophilic GSH to competitively bind with the electrophilic substance 6-MP. Experimental results have proved that the presented SERS protocol can be utilized as an effective tool for accessing the release of anticancer drugs.

Excepciones a la prueba prohibida para garantizar el derecho al debido proceso penal, en la Corte Superior de Justicia del Distrito Judicial de Huánuco, 2014 - 2015

OpenAIRE

Flores León, Vilma Felicitas

2016-01-01

La presente investigación ha tenido el objetivo de identificar las excepciones a la prueba prohibida que deben ser admitidas y valoradas para garantizar el derecho al debido proceso penal en la Corte Superior de Justicia del Distrito Judicial de Huánuco, 2014 - 2015, planteándose como una hipótesis que, la investigación de la verdad en el proceso penal, la defensa de los derechos fundamentales de la persona humana y el interés público, son las excepciones a la prueba prohibida que deben ser a...

Visualization of elongation measurements using an SER universal testing platform

Czech Academy of Sciences Publication Activity Database

Pivokonský, Radek; Filip, Petr; Zelenková, Jana

2015-01-01

Roč. 25, č. 1 (2015), s. 1-8 ISSN 1430-6395 R&D Projects: GA ČR(CZ) GAP105/11/2342 Institutional support: RVO:67985874 Keywords : elongational viscosity * Universal Testing Platform (SER) * polymer melts * LDPE Subject RIV: BK - Fluid Dynamics Impact factor: 1.241, year: 2015

Coupling FT Raman and FT SERS microscopy with TLC plates for in situ identification of chemical compounds

Science.gov (United States)

Caudin, J. P.; Beljebbar, A.; Sockalingum, G. D.; Angiboust, J. F.; Manfait, M.

1995-11-01

Direct analysis of sub-femtogram quantities of chemical compounds on thin layer chromatography plates has been made possible by associating Fourier transform Raman microspectroscopy with SERS spectroscopy. The interfacing elements of the FT Raman microscope system are discussed and optimised such that a lateral resolution on the micron scale is achieved in the sample plane. Micro-FT SERS results obtained from a model biological molecule indicate preservation of molecular conformation upon adsorption at the SERS active surface. With NIR radiation it is thus possible to analyse plates with or without fluorescence indicators.

O ser adolescente gestante em transição: um enfoque de cuidar-pesquisar sob a ótica da enfermagem

Directory of Open Access Journals (Sweden)

Ivete Palmira Sanson Zagonel

2002-08-01

Full Text Available Este trabalho tem como objeto o significado do ex-sistir feminino na cotidianidade diante da transição da adolescência e gestação. Objetiva compreender o sentido de ser adolescente gestante em transição ex-sistindo, como fenômeno situado, diante da simultaneidade dos eventos vitais, expressos pelos discursos e cuidar do ser adolescente gestante ao mesmo tempo em que desvela o sentido que funda a simultaneidade transicional feminina dos eventos vitais. Foram analisados oito discursos, utilizando a entrevista fenomenológica guiada pela questão norteadora "o que é ser adolescente e gestante em transição ex-sistindo, como fenômeno situado diante da simultaneidade dos eventos vitais, enquanto este ser é cuidado". A análise compreensiva dos depoimentos deu-se à luz da hermenêutica heideggeriana. Permitiu desvelar o ser adolescente gestante em transição, enquanto ser de possibilidades, projeta-se enquanto ser exsistindo, mostra-se surpresa, temerosa, fragilizada, vivência a ambiguidade entre o prazer e o sofrimento, a partir das significações atribuídas às vivências.

Using a silver-enhanced microarray sandwich structure to improve SERS sensitivity for protein detection.

Science.gov (United States)

Gu, Xuefang; Yan, Yuerong; Jiang, Guoqing; Adkins, Jason; Shi, Jian; Jiang, Guomin; Tian, Shu

2014-03-01

A simple and sensitive method, based on surface-enhanced Raman scattering (SERS), for immunoassay and label-free protein detection is reported. A series of bowl-shaped silver cavity arrays were fabricated by electrodeposition using a self-assembled polystyrene spheres template. The reflection spectra of these cavity arrays were recorded as a function of film thickness, and then correlated with SERS enhancement using sodium thiophenolate as the probe molecule. The results reveal that SERS enhancement can be maximized when the frequency of both the incident laser and the Raman scattering approach the frequency of the localized surface plasmon resonance. The optimized array was then used as the bottom layer of a silver nanoparticle-protein-bowl-shaped silver cavity array sandwich. The second layer of silver was introduced by the interactions between the proteins in the middle layer of the sandwich architecture and silver nanoparticles. Human IgG bound to the surface of this microcavity array can retain its recognition function. With the Raman reporter molecules labeled on the antibody, a detection limit down to 0.1 ng mL(-1) for human IgG is easily achieved. Furthermore, the SERS spectra of label-free proteins (catalase, cytochrome C, avidin and lysozyme) from the assembled sandwich have excellent reproducibility and high quality. The results reveal that the proposed approach has potential for use in qualitative and quantitative detection of biomolecules.

Moniliophthora roreri (Cif y Par Evans et al. en el cultivo de cacao

Directory of Open Access Journals (Sweden)

Fernando David Sánchez Mora

2012-01-01

Full Text Available Más de un siglo, el cacao (Theobroma cacaoL. en el Ecuador ha sido fuente importante de ingresos para losagricultoresy de divisas para el país, llegando a ser uno de los exportadores más grandes a nivel mundial.Posteriormente, perdió paulatinamente ese estatus debido al ataque de enfermedades, entre ellas la moniliasiscausada por [Moniliophthoraroreri(Cif y ParEvanset al.]. Esta enfermedad puede causar daños hasta del80% en la producción. Actualmente no existe mucha información actualizada y científica, sobre su ocurrencia,sintomatología, etiología, epidemiología, ciclo de vida y manejo o estrategias de controlde la mencionadaenfermedad, por la tanto se realiza esta revisión con estos tópicos importantes, aportando con esto a esta áreadel conocimiento.

Influence of the OGG1 Ser326Cys polymorphism on oxidatively damaged DNA and repair activity

DEFF Research Database (Denmark)

Jensen, Annie Aarup; Løhr, Mille; Eriksen, Louise

2012-01-01

of the comet assay. We collected blood samples from 1,019 healthy subjects and genotyped for the OGG1 Ser326Cys polymorphism. We found 49 subjects homozygous for the variant genotype (Cys/Cys) and selected same numbers of age-matched subjects with the heterozygous (Ser/Cys) and homozygous wild-type genotype...

SERS detection of the biomarker hydrogen cyanide from Pseudomonas aeruginosa cultures isolated from cystic fibrosis patients

DEFF Research Database (Denmark)

Lauridsen, Rikke Kragh; Madsen Sommer, Lea Mette; Johansen, Helle Krogh

2017-01-01

. The P. aeruginosa biomarker hydrogen cyanide (HCN) contains a triple bond, which is utilized in this study because of the resulting characteristic C≡N peak at 2135 cm-1 in a Raman spectrum. The Raman signal was enhanced by surface-enhanced Raman spectroscopy (SERS) on a Au-coated SERS substrate. After...

PGC-1alpha Gly482Ser polymorphism associates with hypertension among Danish whites

DEFF Research Database (Denmark)

Andersen, Gitte; Wegner, Lise; Jensen, Dorit Packert

2005-01-01

in combination with previously published results. The Ser/Ser genotype was significantly associated with a reduced risk of hypertension and with lower systolic, diastolic, and mean arterial blood pressure levels, predominantly among women. Finally, in a combined analysis using data obtained in both sexes...... to elucidate the differential role of this polymorphism in men and women.......PGC-1alpha is a coactivator of numerous transcription factors and is expressed in tissues with high energy demands and abundant in mitochondria. It is induced in the myocardium on fasting and physical exercise, and cardiac-specific overexpression stimulates mitochondrial biogenesis in mice...

Dilemas e conflitos de ser mãe na vigência do HIV/Aids Dilemas y conflictos de ser madre en casos de VIH/Sida Dilemmas and conflitcs of being a mother with HIV/Aids

Directory of Open Access Journals (Sweden)

Marli Teresinha Gimeniz Galvão

2010-06-01

Full Text Available Objetivou-se apreender os dilemas e conflitos revelados por mulheres que engravidaram na vigência da infecção pelo HIV/Aids. Estudo qualitativo com oito mulheres atendidas em ambulatório em Fortaleza-CE. Mediante entrevistas observou-se que as mulheres gestam com expectativa do resultado da sorologia do concepto; depois de nascidos vivenciam incertezas e mantêm superproteção da criança. Relatam maneiras inadequadas da comunicação do diagnóstico e pouca orientação para gestar em face do HIV. As mulheres transformam o desejo de ser mãe em realidade. Para elas, lidar com uma criança com possibilidade de contrair infecção pelo HIV é algo além de sua capacidade. Conclui-se ser essencial oferecer suporte emocional e social para essas mulheres independente das fases da vida.La finalidad fue aprehender los dilemas y conflictos revelados por mujeres infectadas por el VIH/Sida que quedaron embarazadas. Estudio cualitativo con ocho mujeres atendidas en ambulatorio en Fortaleza-CE. Mediante entrevistas fue observado que las mujeres gestan con expectativa del resultado de la serología del concepto; después de nacidos viven incertidumbres y mantienen protección exagerada del niño. Relatan maneras inadecuadas de comunicar el diagnóstico y poca orientación para gestar ante el VIH. Las mujeres transforman el deseo de ser madre en realidad. Para ellas, lidiar con un niño con posibilidad de contraer infección por el VIH es algo más allá de su capacidad. Se concluye que es esencial ofrecer soporte emocional y social para esas mujeres independientemente de las fases de la vida.This study aimed to apprehend the dilemmas and conflicts revealed by women infected with HIV/Aids who got pregnant. This qualitative study involved eight women attended at an outpatient clinic in Fortaleza-CE. Through interviews, it was observed that the women go through their pregnancy with expectations about their child's serological status; after birth, they

Evaluation and Optimization of Paper-Based SERS Substrate for Potential Label-Free Raman Analysis of Seminal Plasma

Directory of Open Access Journals (Sweden)

Zufang Huang

2017-01-01

Full Text Available Characterization and optimization of paper SERS substrate were performed in detail, in which morphologies and distribution of silver nanoparticles (AgNPs on the paper substrate pretreated with different concentrations of NaCl and the subsequent soaking with colloidal AgNPs for different period of time were evaluated. Our results show that both NaCl concentration and soaking time with AgNPs have a significant influence on SERS enhancement, showing that an optimal EF of 2.27 × 107 was achieved when the paper substrate was treated with 20 mM NaCl and one-hour soak with AgNPs. Moreover, seminal plasma (SP was specifically selected to evaluate the performance of paper-based SERS substrate for potential clinical detection and diagnosis. The optimization of the paper SERS substrate demonstrates potential applications in reliable on-site detection of SP and clinical diagnosis of fertility-related diseases as well.

Multi-branched gold nanostars with fractal structure for SERS detection of the pesticide thiram

Science.gov (United States)

Zhu, Jian; Liu, Mei-Jin; Li, Jian-Jun; Li, Xin; Zhao, Jun-Wu

2018-01-01

The surface-enhanced Raman scattering (SERS) activity of multi-branched gold nanostars with fractal structure has been investigated for trace detection of pesticide thiram. Raman spectrum results show that the gold nanostars substrate can produce about 102 fold stronger signal than the thiram alone with the thiram concentration increase of 103 times and 1.4 fold stronger signal than the gold nanostars without fractal feature. In the detection procedure, the most prominent SERS peak at 1376 cm- 1 has been chosen to characterize and quantify the concentration of thiram. Experimental results indicate this Raman substrate based on fractal gold nanostars exhibits excellent selective probing performance for thiram with a detection limit as low as 10- 10 M in solution and 0.24 ng/cm2 in apple peels. Interference experiment results show that the effects from the interfering pesticides could be neglected in the detection procedure. Therefore, the gold nanostars as a SERS substrate have excellent sensitivity and selectivity.

SER Derivation and Power Optimization of a Two-Way MultiRelay Cooperative Communication System

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Shakeel-Ur-Rehman Rehman

2014-01-01

Full Text Available In this paper, we consider Rayleigh fading based cooperative communication system with AaF (Amplify and Forward relaying using multiple relays. We take spectrally efficient two-way model of cooperative communication terminals and formulate performance evaluation framework in terms of SER (Symbol Error Rate. We not only consider fading channel for this performance evaluation but also consider the effect of relay terminal location into our model which does not require any CSI (Channel State Information at transmitting nodes. We have proposed power allocation framework for these nodes and analytically derived SER performance results. We have numerically evaluated this framework for power optimization as well as minimizing required SER. Significant performance improvement as compared with equal power sharing among the cooperating terminals is achieved using our proposed framework. It is shown that virtual cooperative antenna configurations is able to demonstrate up to 3dB gain as compared with co-located antenna configurations. Thus incorporating relay location information for performance evaluation results significant power savings

Nanostructured gold microelectrodes for SERS and EIS measurements by incorporating ZnO nanorod growth with electroplating

Science.gov (United States)

Zong, Xianli; Zhu, Rong; Guo, Xiaoliang

2015-01-01

In this paper, a fine gold nanostructure synthesized on selective planar microelectrodes in micro-chip is realized by using an advanced hybrid fabrication approach incorporating growth of nanorods (NRs) with gold electroplating. By this developed nanostructure, integration of in-situ surface-enhanced Raman spectroscopy (SERS) detection with electrochemical impedance spectroscopy (EIS) measurement for label-free, nondestructive, real-time and rapid monitoring on a single cell has been achieved. Moreover, parameters of Au nanostructures such as size of nanoholes/nanogaps can be controllably adjusted in the fabrication. We have demonstrated a SERS enhancement factor of up to ~2.24 × 106 and double-layer impedance decrease ratio of 90% ~ 95% at low frequency range below 200 kHz by using nanostructured microelectrodes. SERS detection and in-situ EIS measurement of a trapped single cell by using planar microelectrodes are realized to demonstrate the compatibility, multi-functions, high-sensitivity and simplicity of the micro-chip system. This dual function platform integrating SERS and EIS is of great significance in biological, biochemical and biomedical applications. PMID:26558325

Optimizing silver-capped silicon nanopillars to simultaneously realize macroscopic, practical-level SERS signal reproducibility and high enhancement at low costs

DEFF Research Database (Denmark)

Wu, Kaiyu; Rindzevicius, Tomas; Schmidt, Michael Stenbæk

2017-01-01

and show that the improved structures exhibit unrivalled macroscale SERS uniformities (RSD: ∼2.5% in millimeter scale, ∼7% in wafer scale) and reproducibility (RSD: ∼1.5% across 3 wafers), while at the same time exhibiting a very large average SERS enhancement factor of >108. The obtained SERS uniformity...

Effect of Etching on the Optical, Morphological Properties of Ag Thin Films for SERS Active Substrates

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Desapogu Rajesh

2013-01-01

Full Text Available Structural, optical, and morphological properties of Ag thin films before and after etching were investigated by using X-ray diffraction, UV-Vis spectrophotometer, and field emission scanning electron microscopy (FESEM. The HNO3 roughened Ag thin films exhibit excellent enhancement features and better stability than pure Ag thin films. Further, the Ag nanostructures are covered with Rhodamine 6G (Rh6G and then tested with surface enhanced raman spectroscopy (SERS for active substrates. Etched Ag films were found to exhibit a strong SERS effect and excellent thermal stability. Hence, the present method is found to be useful in the development of plasmon-based analytical devices, especially SERS-based biosensors.

Towards field detection of polycyclic aromatic hydrocarbons (PAHs) in environment water using a self-assembled SERS sensor

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Yan, Xia; Shi, Xiaofeng; Yang, Jie; Zhang, Xu; Jia, Wenjie; Ma, Jun

2017-10-01

A self-assembled surface enhanced Raman scattering (SERS) sensor is reported in this paper. To achieve high sensitivity, a high sensitive SERS substrate and a high efficient self-constructed light path were made. The SERS substrate was composed by gold nanoparticles (AuNPs, pH=13), glycidyl methacrylate-ethylene dimethacrylate (GMA-EDMA) porous material and syringe filter. The substrate had a good repeatability, and the relative standard deviation (RSD) of the same substrate was less than 5%. The efficiency of the self-constructed light path is about two times better than RPB Y type reflection fiber when the energy density was roughly equal on samples. The size of the SERS sensor is 350×300×180 mm and the weight is 15 kg. Its miniaturization and portable can comply with the requirements of field detection. Besides, it has good sensitivity, stability and selectivity. For lab experiments, strong enhancements of Raman scattering from organic pollutant polycyclic aromatic hydrocarbons (PAHs) molecules were exhibited. The dependences of SERS intensities on concentrations of PAHs were investigated, and the results indicated that they revealed a satisfactory linear relationship in low concentrations. The limits of detection (LODs) of PAHs phenanthrene and fluorene are 8.3×10-10 mol/L and 7.1×10-10 mol/L respectively [signal to noise ratio (S/N) =3]. Based on this SERS sensor, signals of benzo (a) pyrene and pyrene were found in environmental water and the sensor would be an ideal candidate for field detection of PAHs.

Efectividad del Nd- Yag láser en la capsulotomía posterior Effectiveness of Nd-Yag laser in posterior capsulotomy

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Alina Pedroso Llanes

2004-06-01

Full Text Available Este trabajo se propuso determinar la efectividad del neodimio YAG láser (Nd-YAG láser en la realización de capsulotomía posterior a 150 pacientes (ojos operados de catarata senil o presenil en el centro de Microcirugía Ocular en Serie del Hospital Oftalmológico Docente "Ramón Pando Ferrer" en el período comprendido de febreroa diciembre de 1999. En este grupo se analizaron como variables la edad, sexo, raza, implante o no de lente intraocular, tipo de opacidad de cápsula posterior, agudeza visual con corrección pre y postratamiento, complicaciones encontradas, comportamiento de la presión intraocular, así como la energía empleada para realizar dicho proceder. Estos datos se analizaron a través de tablas de contingencias Chi cuadrado. Como resultado de esta investigación se encontró que el láser es altamente efectivo para el mejoramiento de la agudeza visual en los pacientes afectados de catarata secundaria (74,7 %. Se observó además aumento transitorio de la presión intraocular en las dos primeras horas posteriores al láser (60,7 %, y no se encontró ninguna complicación que afectara la visión de los ojos estudiadosThe aim of this paper was to determine the effectiveness of neodymium YAG laser (Nd-YAG laser on performing the posterior capsulotomy in 150 patients (eyes operated on of senile or presenile cataract at the Center of Serial Ocular Microsurgery (CSOM of "Ramón Pando Ferrer" Ophthalmological Teaching Hospital from February to December 1999. Age, sex, race, implantation or not of the intraocular lens (IOL, type of opacity of the posterior capsule, visual acuity with pre- and posttreatment correction (Avcc, complications found, behavior of the intraocular pressure (IOP, as well as the energy used to carry out such procedure, were analyzed. The Chi square contingency tables were used to this end. As a result of this research, it was found that the laser is highly effective for improving visual acuity in patients

La cuestión de Dios en Heidegger: metafísica, pensamiento del ser, pensamiento según la poesía

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NÉSTOR CORONA

2008-01-01

Full Text Available El artículo plantea la cuestión de Dios a partir de la crítica de Heidegger a la metafísica. En primer lugar, se presenta el carácter derivado del proceder lógico fundamentante causalístico, para mostrar luego que, según Heidegger, el fundamento verdadero que se ha ocultado, dando lugar así al fundamentar óntico, es el ser mismo (abismo que, manifestado como tal, anula el preguntar "¿por qué?". Desde allí queda criticado el ente supremo, causa primera, que la metafísica onoto-teo-lógica ha identificado con Dios. Dios se presenta en su divinidad, según Heidegger, en primer lugar en la palabra de Hólderlin, donde el ser-Cuarteto, con sus Divinos, señala hacia ese Dios, que así aparece más allá de tal ser-Cuarteto. El pensamiento tiene entonces su tarea propia en el seguimiento de ese poetizar. Tanto el poeta, como el pensador del ser que llega hasta lo Ereígnísy el pensador que piensa en seguimiento de la poesía acaban en el silencio. En tal silencio, precedido por "nombres que no nombran", se hace presente propiamente el Dios divino, el Dios "verdadero" según Heidegger.The article sets out the question of God from the starting point of Heidegger's criticism of metaphysics. In the first place, the derivative character of the fundamentally causal, logical procedure is presented in order to then show that, according to Heidegger, the true fundamental that has been hidden, resulting in this way in ontic fundamentation, is Being itself (abyss that, manifested as such, annuls the questioning "Why?" From there the Supreme Being, First Cause, that onto-theo-logical metaphysics has identified with God, is criticized. God is presented in His divinity, according to Heidegger, in the first place in the word of Hólderlin, where the Quartet-being, with his Divine beings, points towards that God, which thus appears beyond such a Quartet-being. Thinking then has as its own task the following of that poetic language. The poet as much as

Ser reina

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José Manuel NIETO SORIA

2006-07-01

Full Text Available L’historiographie du règne des Rois Catholiques, héritière directe de celle des autres Trastamare, se caractérise par son étroite relation avec des enjeux politiques concrets. L’activité historiographie s’est ainsi inscrite elle-même dans le cadre des conflits politiques en cours. C’est pourquoi la royauté d’Isabelle Ire de Castille impliqua une bonne part de la production historiographique de cettte époque : soit qu’on dénonçât un déficit de légitimité dû à sa condition féminine, soit qu’on démentît, au contraire, ce déficit en attribuant à la reine des qualités « masculines ». Bien entendu, ces débats furent fonction de l’engagement politique de chacun des historiens.La cronística y la historiografía del reinado de los Reyes Católicos, como directas herederas de la labor historiográfica de la época de los monarcas Trastámara, se caracterizó por su estrecha vinculación con intereses políticos concretos, inscribiéndose la propia actividad historiográfica en el marco de los conflictos políticos en curso. Por ello, la dimensión regia de Isabel I de Castilla supuso una dimensión significativa del quehacer historiográfico de la época, bien para plantear un déficit de legitimidad por razón de su propia condición femenina, bien para negar tal déficit con la atribución de “cualidades masculinas” en su persona. De este modo, la toma en consideración del hecho de “ser reina” representó una dimensión significativa del quehacer historiográfico, de acuerdo siempre con los compromisos políticos de los distintos historiadores de la época.

Tratamento inseticida e qualidade de sementes de milho durante o armazenamento Insecticide treatment and seed quality of corn during storage

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Oscar José Smiderle

1999-01-01

Full Text Available A presente pesquisa objetivou verificar os efeitos dos inseticidas deltametrina, clorpirifos, fosfina e da terra diatomácea no controle de insetos em sementes de milho, armazenadas durante 12 meses, visando oferecer alternativas de produtos inseticidas, utilizando delineamento inteiramente casualizado. As sementes do híbrido AG 303, tratadas com deltametrina e clorpirifos, aplicados na forma isolada ou em combinação, fosfina e terra diatomácea, foram acondicionadas em sacos de papel multifoliado e armazenadas por doze meses (maio/1997 a abril/1998 em condições normais de ambiente. Em intervalos bimestrais, sete épocas no total, as sementes foram submetidas às seguintes determinações: exame de sementes infestadas, massa de 100 sementes, teste de germinação, teste de frio, envelhecimento acelerado, condutividade elétrica, emergência de plântulas em campo e velocidade de emergência de plântulas. A análise dos dados e interpretação dos resultados permitiram concluir que: os inseticidas deltametrina e clorpirifos (isolados ou associados, a terra diatomácea e a fosfina promovem, de maneira similar, o controle de insetos-praga que ocorrem no armazenamento e não causam toxicidade às sementes; a qualidade fisiológica das sementes é efetivamente preservada pelos tratamentos com inseticidas químicos e terra diatomácea.To study the effects of insecticides (deltamethrin, chlorpyrifos, phosphin, and diatomaceous earth on the insect control of stored corn seeds during 12 months, this research was performed to find an alternative product, using a randomized design. Seeds of the hybrid AG 303 were treated with either isolated or combined deltamethrin and chlorpyrifos, phosphin and diatomaceous earth, and they were further arranged into multifoliated paper bags and stored for twelve months (May/1997 through April/1998 under normal environmental conditions. Seeds were submitted to an infested seed exam, mass of 100 seeds, germination

Incapacidades laborales: problemas en la reinserción al trabajo

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Sampaio Rosana F.

1999-01-01

Full Text Available En este estudio transversal se evalúan los factores asociados con la probabilidad de reincorporación al trabajo de los trabajadores incapacitados permanentes para la profesión habitual por accidente de trabajo. La muestra la forman los casos atendidos por el Centro de Rehabilitación Profesional (CRP de Belo Horizonte, Brasil, en 1995. Se analiza el hecho del trabajador ser aceptado o no en el programa, así como la posterior reinserción laboral mediante modelos logit. Respecto al primer, los factores más influyentes fueron la edad, la presencia de Lesiones por Esfuerzo Repetitivo (LER y el nivel de estudios. Analizado el resultado del programa, se observa que los hombres jóvenes de alta escolarización son los que tienen mayor probabilidad de reinserción laboral (90,9%. Existe una incongruencia respecto a la admisión de los trabajadores y el resultado del programa: para su admisión, el trabajador debe cumplir un perfil exigido por el mercado en lo que se refiere a la edad y al nivel de estudios; los portadores de LER cumplen estos criterios y, sin embargo, son los que con mayor dificultad se reincorporan al trabajo. Se observa, así mismo, una discriminación laboral clara hacia las mujeres, a pesar del hecho que las mismas presentan iguales condiciones de edad o de nivel educativo que los hombres.

Incapacidades laborales: problemas en la reinserción al trabajo

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Rosana F. Sampaio

1999-10-01

Full Text Available En este estudio transversal se evalúan los factores asociados con la probabilidad de reincorporación al trabajo de los trabajadores incapacitados permanentes para la profesión habitual por accidente de trabajo. La muestra la forman los casos atendidos por el Centro de Rehabilitación Profesional (CRP de Belo Horizonte, Brasil, en 1995. Se analiza el hecho del trabajador ser aceptado o no en el programa, así como la posterior reinserción laboral mediante modelos logit. Respecto al primer, los factores más influyentes fueron la edad, la presencia de Lesiones por Esfuerzo Repetitivo (LER y el nivel de estudios. Analizado el resultado del programa, se observa que los hombres jóvenes de alta escolarización son los que tienen mayor probabilidad de reinserción laboral (90,9%. Existe una incongruencia respecto a la admisión de los trabajadores y el resultado del programa: para su admisión, el trabajador debe cumplir un perfil exigido por el mercado en lo que se refiere a la edad y al nivel de estudios; los portadores de LER cumplen estos criterios y, sin embargo, son los que con mayor dificultad se reincorporan al trabajo. Se observa, así mismo, una discriminación laboral clara hacia las mujeres, a pesar del hecho que las mismas presentan iguales condiciones de edad o de nivel educativo que los hombres.

Suero autólogo al 50 % en las queratitis bacterianas

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Arelys Ariocha Cambas Andreu

Full Text Available Objetivo: evaluar el comportamiento de las queratitis bacterianas con el tratamiento coadyuvante de suero autólogo tópico al 50 %. Métodos: estudio comparativo, longitudinal y prospectivo. La muestra estuvo constituida por 60 pacientes, divididos de forma aleatoria en dos grupos: A utilizó tratamiento antibiótico convencional y suero autólogo y B utilizó solo tratamiento antibiótico convencional (cefazolina y amikacina. Los datos almacenados se procesaron utilizando el paquete estadístico SPSS 15. Las variables se expresaron según sus respectivas medidas de resumen y para la comparación de las terapias se aplicaron pruebas de hipótesis, con un nivel de confianza del 95 % y de error inferior al 0,05 %. Resultados: predominaron en los aislamientos microbiológicos Staphylococcus y Pseudomonas; seguidas por los Streptococcus, gonococos y enterobacterias. En cuanto al tiempo de aparición de los signos que favorecen la cicatrización corneal y la respuesta terapéutica, encontramos que con la aplicación tópica del suero autólogo, en casi dos tercios de los pacientes, estos se manifestaron a partir de la segunda semana de tratamiento y se obtuvo una respuesta terapéutica favorable. Conclusiones: El suero autólogo al 50 % resulta ser un complemento terapéutico efectivo en el manejo de las queratitis infecciosas de etiología bacteriana.

Ser professor de Língua Inglesa em cursos livres: identificações e práticas docentes

OpenAIRE

Martins, Maria Waleska Siga Peil

2014-01-01

Adapte-se ou fique para trás parece ser a ordem do dia na sociedade pós-moderna e estar pronto para mudanças passa a ser requisito em um mundo relativamente estável. É a partir dessas constatações que se traz a discussão para o âmbito educacional, mais especificamente, ao campo do ensino de língua inglesa. Quem é o professor de inglês da pós-modernidade e como este se representa diante das várias possibilidades entre o ser e o estar? Uma pesquisa sobre identidade voltada para ...

Rapid and sensitive phenotypic marker detection on breast cancer cells using surface-enhanced Raman scattering (SERS) imaging.

Science.gov (United States)

Lee, Sangyeop; Chon, Hyangah; Lee, Jiyoung; Ko, Juhui; Chung, Bong Hyun; Lim, Dong Woo; Choo, Jaebum

2014-01-15

We report a surface-enhanced Raman scattering (SERS)-based cellular imaging technique to detect and quantify breast cancer phenotypic markers expressed on cell surfaces. This technique involves the synthesis of SERS nano tags consisting of silica-encapsulated hollow gold nanospheres (SEHGNs) conjugated with specific antibodies. Hollow gold nanospheres (HGNs) enhance SERS signal intensity of individual particles by localizing surface electromagnetic fields through pinholes in the hollow particle structures. This capacity to enhance imaging at the level of single molecules permits the use of HGNs to detect specific biological markers expressed in living cancer cells. In addition, silica encapsulation greatly enhances the stability of nanoparticles. Here we applied a SERS-based imaging technique using SEHGNs in the multiplex imaging of three breast cancer cell phenotypes. Expression of epidermal growth factor (EGF), ErbB2, and insulin-like growth factor-1 (IGF-1) receptors were assessed in the MDA-MB-468, KPL4 and SK-BR-3 human breast cancer cell lines. SERS imaging technology described here can be used to test the phenotype of a cancer cell and quantify proteins expressed on the cell surface simultaneously. Based on results, this technique may enable an earlier diagnosis of breast cancer than is currently possible and offer guidance in treatment. © 2013 Elsevier B.V. All rights reserved.

SERS study of surface plasmon resonance induced carrier movement in Au@Cu2O core-shell nanoparticles

Science.gov (United States)

Chen, Lei; Zhang, Fan; Deng, Xin-Yu; Xue, Xiangxin; Wang, Li; Sun, Yantao; Feng, Jing-Dong; Zhang, Yongjun; Wang, Yaxin; Jung, Young Mee

2018-01-01

A plasmon induced carrier movement enhanced mechanism of surface-enhanced Raman scattering (SERS) was investigated using a charge-transfer (CT) enhancement mechanism. Here, we designed a strategy to study SERS in Au@Cu2O nanoshell nanoparticles with different shell thicknesses. Among the plasmonically coupled nanostructures, Au spheres with Cu2O shells have been of special interest due to their ultrastrong electromagnetic fields and controllable carrier transfer properties, which are useful for SERS. Au@Cu2O nanoshell nanoparticles (NPs) with shell thicknesses of 48-56 nm are synthesized that exhibit high SERS activity. This high activity originates from plasmonic-induced carrier transfer from Au@Cu2O to 4-mercaptobenzoic acid (MBA). The CT transition from the valence band (VB) of Cu2O to the second excited π-π* transition of MBA, and is of b2 electronic symmetry, which was enhanced significantly. The Herzberg-Teller selection rules were employed to predict the observed enhanced b2 symmetry modes. The system constructed in this study combines the long-range electromagnetic effect of Au NPs, localized surface plasmon resonance (LSPR) of the Au@Cu2O nanoshell, and the CT contribution to assist in understanding the SERS mechanism based on LSPR-induced carrier movement in metal/semiconductor nanocomposites.

Un ser humano construído socialmente: una aproximación (biotecnológica

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Francesca Randazzo

2011-07-01

Full Text Available Como una construcción social, la (biotecnología no debe ser estudiada fuera del campo social. Desde una perspectiva analítica sobre los imaginarios sociales, la (biotecnología puede ser considerada como un magma social formado por factores biológicos, técnicos, psicológicos, sociológicos y axiológicos. Orbitando alrededor de la metáfora del cyborg, en este artículo nos proponemos construir un enfoque multidisciplinar de esta polycontextura.

¿Cuán liviana puede ser la risa? Nietzsche y levinas frente al “fin del hombre”

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Aïcha Liviana Messina

2012-10-01

Full Text Available El artículo parte de la siguiente lectura: en distintas ocasiones, Levinas se refiere al pensamiento de Nietzsche, a su risa, que “rechaza el lenguaje”; sorprendentemente, Levinas no sitúa a Nietzsche, a diferencia de Heidegger, como el último metafísico, sino que lo descoloca en esta historia, subrayando más bien la “extrema juventud” de la risa nietzscheana. Este artículo propone mostrar cómo la risa nietzscheana se articula con lo que Levinas llamaba una “subjetividad del sujeto inocente de conjunciones ontológicas”. Se concluye con una reflexión sobre la vergüenza y los límites del hombre.

Terapia combinada con magneto, láser y ejercicios en la tendinitis de hombro: Servicio de Rehabilitación Integral José Jacinto Milanés. Junio 2007-junio 2008

OpenAIRE

Solís de la Paz, Dayma; Peñate Brito, Jayne Bárbara

2011-01-01

La magnetoterapia, aunque ha sido utilizada para diversas afecciones ortopédicas, no se ha empleado en la tendinitis asociada al láser y a los ejercicios terapéuticos, por lo que se realizó un estudio explicativo, experimental, tipo ensayo clínico terapéutico, para comprobar la eficacia de esta terapia en pacientes con tendinitis en el Servicio de Rehabilitación Integral José Jacinto Milanés. Se conformaron dos grupos con 42 pacientes, uno experimental con aplicación local de campos magnético...

Tolerancia al co en celdas de combustible

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BIBIAN HOYOS

2008-01-01

Full Text Available El entendimiento completo del proceso de adsorción y posterior oxidación de moléculas de CO en platino es de fundamental importancia para el desarrollo de celdas de combustible poliméricas que operan a baja temperatura. En este trabajo se presenta una revisión de las cinco estrategias experimentales más importantes en la búsqueda de mejorar la tolerancia al CO: disminución del potencial de inicio de la reacción de oxidación, reducción de la cantidad de CO adsorbido, utilización de pequeñas cantidades de oxígeno en la corriente de alimentación al ánodo, aumento de la temperatura de operación y limpieza del CO a la entrada. Aunque se han desarrollado catalizadores bastante promisorios (PtMo y PdAu, todavía se sigue considerando a la mezcla Pt-Ru como el catalizador anódico más eficiente para combustibles que contienen 10 ppm de CO o más. La estrategia de inyectar oxígeno al ánodo parece promisoria pero requiere el desarrollo de nuevas membranas más resistentes y de la implementación de condiciones más seguras de operación de la celda. El diseño estructural de ánodos especiales con múltiples capas soportando catalizadores específicos para cada tipo de combustible puede ser una estrategia muy atractiva.

The hOGG1 Ser326Cys polymorphism contributes to digestive system cancer susceptibility: evidence from 48 case-control studies.

Science.gov (United States)

Wang, Yang; Gao, Xujie; Wei, Feng; Zhang, Xinwei; Yu, Jinpu; Zhao, Hua; Sun, Qian; Yan, Fan; Yan, Cihui; Li, Hui; Ren, Xiubao

2015-02-01

The Ser326Cys polymorphism in the human 8-oxogunaine DNA glycosylase (hOGG1) gene had been implicated in cancer susceptibility. Studies investigating the associations between the Ser326Cys polymorphism and digestion cancer susceptibility showed conflicting results. Therefore, a meta-analysis was performed to derive a more precise estimation of the relationship. We conducted a meta-analysis of 48 studies that included 12,073 cancer cases and 19,557 case-free controls. We assessed the strength of the association using odds ratios (ORs) with 95% confidence intervals (CIs). In our analysis, the hOGG1 Ser326Cys polymorphism was significantly associated with the risk of digestive system cancers (Cys/Cys vs. Ser/Ser: OR = 1.17, 95% CI = 1.00-1.35, P digestive cancers.