NEUROENDOCRINE PEPTIDES IN THE PATHOGENESIS OF COLORECTAL CARCINOMA.

Colorectal carcinoma (CRC) is the third most frequent neoplasm worldwide and the second leading cause of mortality. Neuroendocrine peptides such as glucagon, bombesin, somatostatin, cholecystokinin, and gastrin as well as growth factors such as platelet-derived growth factor, epidermal growth factor, insulin-like growth factor, and fibroblast growth factor have been postulated as being involved in carcinogenesis. The fact that these neuroendocrine peptides are involved in the development of CRC through the activation of growth factors that stimulate a series of molecular pathways that activate oncogenic signaling mechanisms is emphasized in this review. Peptides such as CCK1, serotonin, and bombesin have been found to be over-expressed in human tumor tissues. Meanwhile, the expression of peptides such as GLP2 has been seen mainly in murine models. The information contained in this review provides a better understanding of the role these peptides play in the pathogenesis of CRC for basic and clinical science studies.

Effect of PTPN22, FAS/FASL, IL2RA and CTLA4 genetic polymorphisms on the risk of developing alopecia areata: A systematic review of the literature and meta-analysis.

OBJECTIVES: Genetic association studies on alopecia areata (AA) performed in various populations have shown heterogeneous results. The aim of the current review was to synthesize the results of said studies to estimate the impact of FAS, FASL, PTPN22, CTLA4 and IL2RA gene polymorphisms on AA susceptibility. DESIGN: A systematic literature search was conducted in the Medline, Web of Science, Scopus, EMBASE and LILACS databases. Studies published up to June 2020 were included. The results available in the grey literature including the Open Grey and Google Scholar databases were also used. The texts of potentially related studies were screened by individual reviewers. Evidence of publication bias was assessed using the Newcastle-Ottawa scale and the quality of evidence was assessed using the GRADE system. The quantitative synthesis was performed using the fixed effect model. RESULTS: Out of 1784 articles, we identified 18 relevant articles for the qualitative synthesis and 16 for the quantitative synthesis. In a study of rs2476601 polymorphism of PTPN22 gene, including 1292 cases and 1832 controls, a correlation was found with the risk of developing AA in the allelic model (OR1.49 [95% C:1.13-1.95]), the heterozygous codominant (OR1.44 [95% CI:1:19-1.76]) and dominant model (OR1.43 [95% CI:1.18-1.73]). No association was found between the presence of FASL, PTPN22, CTLA and IL2RA gene polymorphisms with AA susceptibility. CONCLUSIONS: The results suggest that the T allele of the single nucleoid polymorphism (SNP) rs2476601 in PTPN22 gene is a risk factor for developing alopecia areata. However, more robust studies defining the ethnic background of the population of origin are required, so that the risk identified in the present study can be validated. Additionally, a greater number of studies is necessary to evaluate the role of the FAS, FASL, PTPN22, CTLA4 and IL2RA genetic variants, given the heterogenous results found in the literature.

Periodontitis en la diabetes tipo 2 y la copaiba como coadyuvante del tratamiento: reporte de casos / Periodontitis in diabetes and copaiba as a coadjuvant of the treatment: case reports

La diabetes mellitus tipo 2 es una enfermedad metabólica que en estos últimos años viene creciendo en varias regiones del mundo, siendo considerada una pandemia. Entre las complicaciones que se presenta en esta patología, se menciona a la periodontitis como la sexta complicación más común. Así también la diabetes es el mayor factor de riesgo para desarrollar periodontitis, incrementándose tres veces la posibilidad de periodontitis en estas personas, mencionándose el concepto de bidireccionalidad del complejo diabetes-periodontitis. En el presente caso clínico se plantea la posibilidad de uso como apoyo a la terapia periodontal de un producto natural obtenido de la amazonia peruana que por su propiedad antibacteriana estudiada, así como su fácil manejo y costo accesible sería una posible opción para su uso como coadyuvante en la terapia periodontal no quirúrgica en pacientes diabéticos tipo 2 con periodontitis (AU)

Diabetes mellitus type 2 is a metabolic disease that in recent years has been growing in several regions of the world, being considered a pandemic. Among the complications that occur in this pathology, periodontitis is mentioned as the sixth most common complication. Diabetes is also the greatest risk factor for developing periodontitis, increasing the possibility of periodontitis three times in these people, mentioning the concept of bidirectionality of the diabetes-periodontitis complex. In the present clinical case, the possibility of use as a support to the periodontal therapy of a natural product obtained from the Peruvian Amazon, which because of its antibacterial property studied, as well as its easy handling and accessible cost, would be a possible option for its use as an adjunct. in non-surgical periodontal therapy in type 2 diabetic patients with periodontitis. (AU)

MnO2 Nanoparticles Anchored Multi Walled Carbon Nanotubes as Potential Anode Materials for Lithium Ion Batteries.

Herein, we report a facile hydrothermal synthesis of MnO2 nanoparticles anchored multi walled carbon nanotubes (MnO2@MWCNTs) as potential anode materials for lithium-ion (Li-ion) batteries. The prepared MnO2@MWCNTs were characterized by several techniques which confirmed the formation of MnO2 nanoparticles anchored MWCNTs. The X-ray diffraction and Raman-scattering analyses of the prepared material further revealed the effective synthesis of MnO2@MWCNTs. The fabricated Li-ion battery based on MnO2@MWCNTs exhibited a reversible capacity of ~823 mAhg-1 at a current density of 100 mAg-1 for the first cycle, and delivered a capacity of ~421 mAhg-1 for the 60 cycles. The coulombic efficiency was found to be ~100% which showed excellent reversible charge-discharge behavior. The outstanding performance of the MnO2@MWCNTs anode for the Li-ion battery can be attributed to the distinctive morphology of the MnO2 nanoparticles anchored MWCNTs that facilitated the fast transport of lithium ions and electrons and accommodated a broad volume change during the cycles of charge/discharge.

Assembly and Electroluminescence of Sheet-Like Zinc Oxide/Silicon Light-Emitting Diode by Radio Frequency Magnetron Sputtering Technique.

Sheet-like Zinc Oxide/Silicon ([ZnO]/[Si]) light emitting diode (LED) has been fabricated through depositing nanoscale ZnO on the p-type single crystal silicon by using a radio frequency (RF) magnetron sputtering method. The (100), (002) and (101) diffraction peaks can be observed. With the increasing sputtering time, however, the intensity of (100) and (101) diffraction peaks has gradually decreased and the intensity of (002) diffraction peak has gradually enhanced. Through low the sputtering power, the obtained ZnO shows better (002)-orientation growth. Electroluminescence (EL) from [ZnO]/[Si] LED have been decomposed into three emission bands, i.e., UV, green and orange emissions, which origin from the band gap, zinc interstitial or vacancies oxygen and shallow level, respectively. At the low sputtering power, orange emission is disappeared. It is indicated that the structures and EL properties are sensitive to the fabrication conditions. It is important to optimize and tune the fabrication condition for purposeful application in the future works.

Surface analysis by GXRD and XPS in the austenitic steel DIN by nickel ions.

The composition changes in the close to surface of the austenitic stainless steel DIN 1.4981 irradiated at high doses. Theoretical simulations using the SRIM-2013 program show that the damage due to Nickel cation [Ni2+] ions irradiation of 3.66 MeV extends to up 2 µm deep in the steel under study. Then the applications of Grazing incidence X-ray Diffraction (GXRD) and X-ray Photoelectron Spectroscopy (XPS), Gallium cation [Ga3+] ions sputtering assisted, were necessary to detect respectively, any compositional changes with the depth. GXRD differences were recorded in the intensity and it's Full Width at Half Maximum (FWHM), of the austenite (111) diffraction peak, at different depths in the Irradiate Zone (IZ). Through XPS was found that Nickel [Ni], Niobium [Nb], and Manganese [Mn] were depleted it is important to highlight Chromium [Cr], and Molybdenum [Mo] were improved at the irradiated surface; such behavior was contrary to the element migration under irradiation reported for austenitic stainless steels irradiated at low doses.

2D Nanomaterial-Based Surface Plasmon Resonance Sensors for Biosensing Applications.

The absorption and binding energy of material plays an important role with a large surface area and conductivity for the development of any sensing device. The newly grown 2D nanomaterials like black phosphorus transition metal dichalcogenides (TMDCs) or graphene have excellent properties for sensing devices' fabrication. This paper summarizes the progress in the area of the 2D nanomaterial-based surface plasmon resonance (SPR) sensor during last decade. The paper also focuses on the structure of Kretschmann configuration, the sensing principle of SPR, its characteristic parameters, application in various fields, and some important recent works related to SPR sensors have also been discussed, based on the present and future scope of this field. The present paper provides a platform for researchers to work in the field of 2D nanomaterial-based SPR sensors.

Mechatronic design and implementation of a bicycle virtual reality system.

The aim of this study is to design and implement a virtual reality bicycle system based on a functional-based mechatronic design approach. The development of virtual reality technologies with haptic systems demands a proper integration of the involved disciplines to provide immerse experiences for users. The proposed design approach provides a formal manner to gather the subsystems in the mechatronic device. The developed system is divided in a Virtual Reality System (VRS) and a Physical System (PS) for the design process. The former includes an interactive virtual environment in which an Avatar is animated using a simple kinematic bicycle model. The latter includes an adapted mountain bicycle with haptic feedback mechanisms to interact with the user and to produce the corresponding inputs for the bicycle model. Both systems are integrated by a control behavior system that works under two operation modes, where the user carries out virtual tours and gets feedbacks from a stereoscopic display system, audio cues, and haptic mechanisms. A multibody simulation validates the consistency and the integration of the physical system. In addition, a set of experimental results show the performance of instrumentation elements, control strategies, and feedback mechanisms, to provide the user with an immersive experience in the virtual environment. A brief survey was carried out to assess the opinion of users about the virtual bicycle tours, providing feedback for future improvements. The different designed modules and sub-systems allow modifying and enhancing the VRS without major modifications of the PS, or allow enhancing the physical platform without affecting the functionality of the virtual environment.

Toxicidad de agentes antiparasitarios, antimicrobianos e insecticidas sobre larvas del camarón salino Artemia franciscana (Crustacea: Artemiidae) / Toxicity of antiparasitic, antimicrobial agents and insecticides on larvae of brine shrimp Artemia franciscana (crustacea: artemiidae)

Artemia franciscana "camarón salino", es un crustáceo sensible a un amplio rango de compuestos químicos, de fácil manejo en el laboratorio, y con un cultivo relativamente sencillo y barato. El objetivo del presente trabajo fue evaluar la toxicidad de agentes antiparasitarios, antimicrobianos e insecticidas sobre A. franciscana para establecer la concentración prevista que no causa efectos (PNEC) sobre los organismos marinos y obtener los niveles guía para la protección de la vida acuática. Con los nauplios II de A. franciscana, dentro de las 24 h de eclosión, se procedió a realizar los bioensayos de toxicidad calculando la Concentración letal media (CL50) a 24 h y 48 h de exposición. Se observó la siguiente secuencia de mayor a menor toxicidad a 48 h de exposición para tres agentes antiparasitarios comerciales: Mebendazol >Albendazol >Metronidazol. Con relación al efecto tóxico letal de seis agentes antimicrobianos comerciales se vio la siguiente secuencia de mayor a menor toxicidad a 48 h de exposición: Triclosan >Clotrimazol >Itraconazol >Ketoconazol >Oxitetraciclina >Mimosa. El camarón salino mostró efectos de mortalidad por acción de cinco sustancias con propiedades insecticidas, encontrándose el siguiente orden de mayor a menor mortalidad a 48 h de exposición: Cipermetrina >Rotenona >Carbaryl >Canela >Malation. Las tres sustancias químicas calificadas como muy tóxicas y que presentaron los niveles guía más bajos para la protección de la vida acuática fueron Triclosan (0,72 ug·L-1), Cipermetrina (0,84 ug·L-1) y Clotrimazol (0,97 ug·L-1). Se observó que diez (71,42%) de las sustancias químicas mostraron fuerte actividad citotóxica (AU)

Artemia franciscana "brine shrimp", is sensitive to a wide range of chemical structures, and easy handling in the laboratory and with a relatively simple and inexpensive crustacean culture. The aim of this study was to evaluate the toxicity of parasiticides agent, antimicrobials agent and insecticides on A. franciscana to establish Predicted No-Effect Concentration (PNEC) on marine organisms and obtain guidance levels for the protection of aquatic life. With A. franciscana nauplii II, within 24 h of hatching, we proceeded to perform toxicity bioassays calculating the average lethal concentration (LC50) at 24 h and 48 h of exposure. The following sequence of high to low toxicity to 48 h of exposure to three commercial antiparasitic agents were observed: Mebendazole> Albendazole> Metronidazole. Regarding the lethal toxic effect of six commercial antimicrobial agents about A. franciscana, the following sequence of toxicity at 48 h of exposure was observed: Triclosan> Clotrimazole> Itraconazole> Ketoconazole> oxytetracycline> Mimosa. The brine shrimp mortality showed effects on five substances with insecticidal properties, meeting the following order from highest to lowest mortality at 48 h of exposure Cipermethrin >Rotenone >Carbaryl >Cinnamon >Malathion. The three chemicals were classified as very toxic and presented lower levels guidance for the protection of aquatic life were Triclosan (0,72 ug·L-1), Cipermetrina (0,84 ug·L-1) y Clotrimazol (0,97 ug·L-1). Ten of chemicals (71.42%) showed strong cytotoxic activity (AU)

ADMINISTRATION OF EARLY POST-PARTUM ORLAN DRENCH IN DAIRY COWS: EFFECT ON METABOLIC PROFILE / ADMINISTRACIÓN ORAL DE DRENCH EN EL POSPARTO TEMPRANO EN VACAS LECHERAS: EFECTO SOBRE EL PERFIL METABÓLICO

Some prophylactic treatments have been proposed in high-yielding dairy cattle in order to minimize the effects of negative energy balance and some disturbances such as hypocalcaemia and ketosis. The objective of this study was to evaluate the effects of two doses of Drench within 24 h after calving on the metabolic profile and prevention of ketosis. A total of 48 cows from a herd in Rio Grande do Sul state (southern Brazil) was used in the study. The animals were randomly selected and treated orally with Drench (N= 32, propylene glycol, electrolytes and choline in 40 L of water) and water (N= 16) used as control. Blood samples were collected by blood coccygeal venipuncture through a vacutainer plain system tubes. Biochemical determinations were performed in serum (albumin, urea, cholesterol, triglycerides, non-esterified fatty acids -NEFA-, calcium, phosphorus, magnesium, aspartate transaminase -AST- and gammaglutamyl-transferase -GGT-) and a cow-side determination of beta-hydroxybutyrate (BHB) was performed using the Abbot blood Precision Xtra system. All cows in the experiment had their milk production controlled. The Drench treatment produces a tendency to a better milk yield (32.5 vs 29.6 L/cow/day) and helps to prevent subclinical ketosis, as indicated by a lesser prevalence of subclinical ketosis (29.7% vs 37.2%) and mean values of BHB (1.19 vs 1.27 mmol/L) as well as a lesser lipolysis as indicated by NEFA values (509 vs 1.560 pmol/L). The other components of the metabolic profile did not have substantial effects between treatments. In short, on the conditions of the present work, the Drench treatment is an effective management tool for prevention of subclinical ketosis and severe lipolysis.

Alguns tratamentos profiláticos têm sido propostos em vacas leiteiras de alta produção a fim de minimizar os efeitos do balanço energético negativo e alguns distúrbios como hipocalcemia e cetose. Os objetivos desse estudo foram avaliar os efeitos da administração de duas doses de Drench em até 24 h depois do parto sobre o perfil metabólico e a prevenção da cetose. Um grupo de 48 vacas de um rebanho no Rio Grande do Sul foi usado no estudo. Os animais foram selecionados aleatoriamente e tratado oralmente com Drench (N= 32, propileno-glicol, eletrólitos e colina em 40 L de água) e água (N= 16) usado como controle. Amostras de sangue foram coletadas por punção venosa coccígea, através do sistema vacutainer, em tubos sem anticoagulante. Foram realizadas determinações bioquímicas no soro (albumina, ureia, colesterol, triglicerídeos, ácidos graxos não esterificados -NEFA-, cálcio, fósforo, magnésio, aspartato aminotransferase -AST- e gama-glutamil-transferase -GGT-), e na propriedade, ao pé da vaca, foi feita a determinação do beta-hidroxibutirato (BHB) no sangue com o sistema Abbot Precision Xtra. Todas as vacas do experimento tiveram sua produção leiteira controlada. O tratamento com Drench causou tendência a uma melhor produção de leite (32.5 vs 29.6 L/vaca/dia) e ajudou a prevenir a cetose subclínica, como indicou a menor prevalência (29.7% vs 37.2%) e menores médias de BHB (1.19 vs 1.27 mmol/L) bem como menor lipólise, indicado pelos valores de NE FA (509 vs 1.560 μmol/L). Os demais componentes do perfil metabólico não tiveram efeitos substanciais entre os tratamentos. Em suma, nas condições do presente trabalho, o tratamento com Drench pode ser considerado eficaz como ferramenta para a prevenção de cetose subclínica e da lipólise severa.

[Impact of Lean methodology to improve care processes and levels of satisfaction in patient care in a clinical laboratory]. / Impacto de la metodología Lean en la mejora de procesos asistenciales y niveles de satisfacción en la atención de pacientes en un laboratorio clínico.

INTRODUCTION: The application of the Lean methodology in health institutions is an effective tool to improve the capacity and workflow, as well as to increase the level of satisfaction of patients and employees. OBJECTIVE: To optimise the time of outpatient care in a clinical laboratory, by implementing a methodology based on the organisation of operational procedures to improve user satisfaction and reduce the number of complaints for delays in care. MATERIAL AND METHODS: A quasi-experimental before and after study was conducted between October 2011 to September 2012. XBar and S charts were used to observe the mean service times and standard deviation. The user satisfaction was assessed using service questionnaires. RESULTS: A reduction of 17 minutes was observed in the time of patient care from arrival to leaving the laboratory, and a decrease of 60% in complaints of delay in care. Despite the high staff turnover and 38% increase in the number of patients seen, a culture of empowerment and continuous improvement was acquired, as well as greater efficiency and productivity in the care process, which was reflected by maintaining standards 12 months after implementation. CONCLUSION: Lean is a viable methodology for clinical laboratory procedures, improving their efficiency and effectiveness.

Exclusive-OR Encryption by Photoconduction and Two-Photon Absorption in Carbon Nanotubes.

A two-wave photoconductive system dependent on the nonlinear optical absorption in carbon nano-tubes is presented. Optical irradiation at 532 nm wavelength and 1 nanosecond pulse duration was employed for performing the experiments. A vectorial two-wave mixing configuration was used in order to measure the absorptive and refractive nonlinearities. A single-beam transmittance technique was carried out to evaluate the photoconductivity and also it allows us to confirm the participation of the nonlinear optical absorption displayed by the samples. A two-photon absorption effect was identified as the main physical mechanism associated to the third order absorptive nonlinearity. The exclusive disjunctive logic function was achieved by the optoelectronic response of an interferometric configuration. An ultrasonic spray pyrolysis processing route was utilized for the preparation of the samples. The morphology of the nanotubes was estimated by using scanning electronic microscopy. By combining the photoconductive response of two different carbon nanotubes thin film samples, a straightforward XOR encryption was performed.

Optical Kerr phase shift in a nanostructured nickel-doped zinc oxide thin solid film.

The optical Kerr effect exhibited by a nickel doped zinc oxide thin solid film was explored with femto- and pico-second pulses using the z-scan method. The samples were prepared by the ultrasonic spray pyrolysis technique. Opposite signs for the value of the nonlinear refractive index were observed in the two experiments. Self-defocusing together with a two-photon absorption process was observed with 120 ps pulses at 1064 nm, while a dominantly self-focusing effect accompanied by saturated absorption was found for 80 fs pulses at 825 nm. Regarding the nanostructured morphology of the resulting film, we attribute the difference in the two ultrafast optical responses to the different physical mechanism responsible of energy transfer generated by multiphoton processes under electronic and thermal effects.

Modulation of the propagation speed of mechanical waves in silicon quantum dots embedded in a silicon-nitride film.

Using a vectorial picosecond self-diffraction method, we evaluate the modification of the speed of the sound in a silicon-nitride film containing silicon quantum dots prepared by remote plasma-enhanced chemical vapor deposition. Our non-contact technique is based on the stimulation of the electrostriction contribution to the nonlinearity of index exhibited by the sample in a multiwave mixing laser experiment. We identified the electronic birefringence using two of the incident beams to generate a self-diffraction signal, then, we modified the third order nonlinear response by means of the optical Kerr effect given by a phase-mismatched third beam which induced electrostriction. Our results indicated that the speed of the sound in a silicon-nitride film can be simultaneously tailored by an electronic nonlinear refractive index, and by an electrostriction effect, both resulting from silicon quantum dots doping.

Hsp70 protein levels and thermotolerance in Drosophila subobscura: a reassessment of the thermal co-adaptation hypothesis.

Theory predicts that geographic variation in traits and genes associated with climatic adaptation may be initially driven by the correlated evolution of thermal preference and thermal sensitivity. This assumes that an organism's preferred body temperature corresponds with the thermal optimum in which performance is maximized; hence, shifts in thermal preferences affect the subsequent evolution of thermal-related traits. Drosophila subobscura evolved worldwide latitudinal clines in several traits including chromosome inversion frequencies, with some polymorphic inversions being apparently associated with thermal preference and thermal tolerance. Here we show that flies carrying the warm-climate chromosome arrangement O(3+4) have higher basal protein levels of Hsp70 than their cold-climate O(st) counterparts, but this difference disappears after heat hardening. O(3+4) carriers are also more heat tolerant, although it is difficult to conclude from our results that this is causally linked to their higher basal levels of Hsp70. The observed patterns are consistent with the thermal co-adaptation hypothesis and suggest that the interplay between behaviour and physiology underlies latitudinal and seasonal shifts in inversion frequencies.

Ultrafast nonlinear optical response of photoconductive ZnO films with fluorine nanoparticles.

The absorptive and refractive third order nonlinear optical properties exhibited by a ZnO thin solid film with fluorine nanoparticles were studied with picosecond and femtosecond pulses using different techniques. We were able to evaluate the photoconductivity of the material and the quenching of the induced birefringence observed in the presence of two-photon absorption. The samples were prepared by a chemical spray deposition technique. In order to investigate the different contributions of the third order nonlinearities of the film, we analyzed the vectorial self-diffraction effect and the optical Kerr transmittance observed in the sample. A dominantly absorptive nonlinearity was measured at a 532 nm wavelength with 50 ps pulses, while nonlinear refraction was found to be negligible in this regime. On the other side, a pure electronic refractive third order nonlinearity without the contribution of nonlinear absorption was detected at 830 nm with 80 fs pulse duration. A quasi-instantaneous optical response and a strong enhancement in the ultrafast nonlinear refraction with the inhibition of the picosecond two-photon absorption mechanism were measured for the case of the femtosecond excitation.

Do insect pests perform better on highly defended plants? Costs and benefits of induced detoxification defences in the aphid Sitobion avenae.

Induced defences are a typical case of phenotypic plasticity, involving benefits for 'plastic' phenotypes under environments with variable degree of stress. Defence induction, in turn, could be energetically expensive incurring costs on growth and reproduction. In this study, we investigated the genetic variation and induction of detoxification enzymes mediated by wheat chemical defences (hydroxamic acids; Hx), and their metabolic and fitness costs using five multilocus genotypes of the grain aphid (Sitobion avenae). Cytochrome P450 monooxygenases and glutathione S-transferases activities were seen to increase with Hx levels, whereas esterases activity and standard metabolic rate increased in wheat hosts with low Hx levels. Additionally, the intrinsic rate of increase (a fitness proxy) increased in highly defended hosts. However, we did not find significant genetic variation or genotype-host interaction for any studied trait. Therefore, aphids feeding on host plants with elevated chemical defences appeared to reduce their detoxification costs and to increase their reproductive performance, which we interpret as a novel adaptation to defended plants. In brief, this study supports the notion that aphids perform better on highly defended host plants, probably related to the selective pressures during the colonization of New World agroecosystems, characterized by highly defended host plants.

Inhibition of the two-photon absorption response exhibited by a bilayer TiO2 film with embedded Au nanoparticles.

We use two different synthesis approaches for the preparation of TiO(2) films in order to study their resulting third order optical nonlinearity, and its modification by the inclusion of Au nanoparticles in one of the samples. An ultrasonic spray pyrolysis method was used for preparing a TiO(2) film in which we found two-photon absorption as a dominant nonlinear effect for 532 nm and 26 ps pulses; and a purely electronic nonlinearity at 830 nm for 80 fs pulses. A strong optical Kerr effect and the inhibition of the nonlinear optical absorption in 532 nm can be obtained for the first sample if Au nanoparticles embedded in a second TiO(2) film prepared by a sol-gel technique are added to it. We used an optical Kerr gate, z-scan, a multi-wave mixing experiment and an input-output transmittance experiment for measuring the optical nonlinearities.

Influence of colloidal silver nanoparticles on the novel flower-like titanium dioxide oxygen sensor performances.

Titanium dioxide (TiO2-anatase phase) thin films, consisting of agglomerated flower-like nanoparticles, have been synthesized using an ultrasonic spray pyrolysis (USP) method in combination with titanium (IV) oxide acetylacetonate [TiO(acac)2], and methanol at 550 degrees C. These thin films were subsequently thermally treated in air, at 950 degrees C for six hours, and the flower-like particles were transformed into smooth surfaces mainly formed by the TiO2-rutile phase. In order to prepare oxygen sensors of good performance, TiO2 thin films were deposited on interdigitated gold electrodes with contacted alumina substrates. The silver colloidal solution was impregnated on the TiO2 thin film. Since the solvent in which the silver nanoparticles are suspended evaporates at 200 degrees C, the thin films were then annealed at this temperature in air for one hour. The effect of colloidal silver nanoparticles on the response of the thin films TiO2 oxygen sensors has been studied, in a mixture with zero-grade air. The gas-sensing properties of TiO2 sensors in an atmosphere of 10(4) ppm of oxygen were measured between 25 and 500 degrees C. The experimental results obtained with colloidal silver nanoparticles as surface additive show that the sensitivity to an O2 concentration of 100 ppm in zero grade air at 300 degrees C reaches a stationary value of 0.40, and 0.03, for TiO2-anatase and -rutile phase films, respectively. This values are as high as those reported for oxygen sensors prepared by more expensive techniques.

[Effect of the consumption of a food supplement on plasma zinc concentrations of free-living Chilean elderly adults]. / Efecto del consumo de un complemento alimentario en la concentración plasmática de cinc en adultos mayores residentes en Santiago de Chile.

BACKGROUND: Zinc intake is well below recommendation among Chilean free living elderly adults of low socioeconomic level. AIM: To assess the effect of the consumption of a food supplement on plasma zinc concentrations in elderly adults (EA). MATERIAL AND METHODS: Ambulatory EA (> or = 70) with controlled type 2 diabetes mellitus or high blood pressure, ascribed to public family health centers were studied. They were separated in a control and intervention group, without blinding techniques. The intervention group consumed daily 50 g of a special nutritional supplement prepared as a soup or porridge, provided by the Government, for 3 months. The control group did not receive the supplement. A good compliance with the supplement was defined as a consumption of 7 portions per week. A fasting venous blood sample was obtained to determine plasma zinc at the beginning and end of the study. RESULTS: Forty three supplemented EA aged 76+/-5 years (21 women) and 31 non supplemented EA aged 78+/-5 years (20 women), completed 3 months of follow up. Mean compliance with the supplement was 40.5% (95% confidence intervals (CI) 40.3-40.6%). General characteristics of the study subjects upon recruitment were similar, except for the literacy that was higher in the intervention group. We fitted a multiple linear regression model which explained 39% of the variance, where the consumption of the nutritional supplement increased the concentration of plasmatic zinc by 4.14 microg/dL (95% CI 0.25-8.02) (p<0.037), after controlling for sex, age, energy, vitamin E and calcium consumption. CONCLUSIONS: The consumption of a food supplement significantly increased plasma zinc concentrations in Chilean elderly adults.