Alcohol-Triggered Capillarity through Porous Pyrolyzed Paper-Based Electrodes Enables Ultrasensitive Electrochemical Detection of Phosphate.

The sensing field has shed light on an urgent necessity for field-deployable, user-friendly, sensitive, and scalable platforms that are able to translate solutions into the real world. Here, we attempt to meet these requests by addressing a simple, low-cost, and fast electrochemical approach to provide sensitive assays that consist of dropping a small volume (0.5 µL) of off-the-shelf alcohols on pyrolyzed paper-based electrodes before adding the sample (150 µL). This method was applied in the detection of phosphate after the formation of the phosphomolybdate complex (250-860 nm in size). Prior drops of isopropanol allow for the fast penetration of the sample through pores of this hydrophobic paper, delivering hindrance-free redox reactions across increasing active areas and ultimately improving the detection performance. The sensitivity (-1.9 10-6 mA cm-2 ppb-1) and limit of detection (1.1 ppb) were improved, respectively, by factors of 33 and 99 over the data achieved without the addition of isopropanol, listing among the lowest values when compared with those results reported in the literature for phosphate (expressed in terms of the concentration of phosphorus). The approach enabled the quantification of this analyte in real samples with accuracies ranging from 87 to 103%. Furthermore, preliminary measurements demonstrated the successful performance of the electrodes with prior addition of other widely used alcohols, that is, methanol and ethanol. These results may extend the applicability of the method. In special, the scalability and eco-friendly character of the electrode fabrication combined with the sensitivity and simplicity of the analyses make the developed platform a promising alternative that may help to pave the way for a new generation of disposable sensors toward the daily monitoring of phosphate in water samples, thus contributing to prevent ecological side effects.

Effects of Riot Control Training on Systemic Microvascular Reactivity and Capillary Density.

Introduction: The main aim of the present study is to evaluate the effects of strenuous exercise, related to special military training for riot control, on systemic microvascular endothelial function and skin capillary density. Materials and Methods: Endothelium-dependent microvascular reactivity was evaluated in the forearm skin of healthy military trainees (age 23.4 ± 2.3 yr; n = 15) using laser speckle contrast imaging coupled with cutaneous acetylcholine (ACh) iontophoresis and post-occlusive reactive hyperemia (PORH). Functional capillary density was assessed using high-resolution, intra-vital color microscopy in the dorsum of the middle phalanx. Capillary recruitment (capillary reserve) was evaluated using PORH. Microcirculatory tests were performed before and after a 5-wk special military training for riot control. Results: Microvascular endothelium-dependent vasodilatory responses were markedly and significantly reduced after training, compared with values obtained before training. The peak values of microvascular conductance obtained during iontophoresis of ACh or PORH before training (0.84 ± 0.22 and 0.94 ± 0.72 APU/mmHg, respectively) were markedly reduced after training (0.47 ± 0.11 and 0.71 ± 0.14 APU/mmHg; p < 0.0001 and p = 0.0037, respectively). Endothelium-dependent capillary recruitment was significantly reduced after training (before 101 ± 9 and after 95 ± 8 capillaries/mm2; p = 0.0007). Conclusions: The present study showed that a 5-wk strenuous military training, performed in unfavorable climatic conditions, induces marked systemic microvascular dysfunction, mainly characterized by reduced endothelium-dependent microvascular vasodilation and blunted capillary recruitment.

Early regimes of water capillary flow in slit silica nanochannels.

Molecular dynamics simulations are conducted to investigate the initial stages of spontaneous imbibition of water in slit silica nanochannels surrounded by air. An analysis is performed for the effects of nanoscopic confinement, initial conditions of liquid uptake and air pressurization on the dynamics of capillary filling. The results indicate that the nanoscale imbibition process is divided into three main flow regimes: an initial regime where the capillary force is balanced only by the inertial drag and characterized by a constant velocity and a plug flow profile. In this regime, the meniscus formation process plays a central role in the imbibition rate. Thereafter, a transitional regime takes place, in which, the force balance has significant contributions from both inertia and viscous friction. Subsequently, a regime wherein viscous forces dominate the capillary force balance is attained. Flow velocity profiles identify the passage from an inviscid flow to a developing Poiseuille flow. Gas density profiles ahead of the capillary front indicate a transient accumulation of air on the advancing meniscus. Furthermore, slower capillary filling rates computed for higher air pressures reveal a significant retarding effect of the gas displaced by the advancing meniscus.

Substratos e recipientes para a produção de porta-enxertos de citros irrigados por subcapilaridade / Substrates and containers for the citrus rootstocks' production irrigated by capillarity

O conhecimento do porta-enxerto, do substrato e do recipiente são fundamentais para a definição do período necessário para produzir mudas cítricas de qualidade. O objetivo deste trabalho foi avaliar a emergência de plântulas e o desenvolvimento vegetativo de seis porta-enxertos cítricos, cultivados em dois substratos e mantidos em diferentes recipientes, em sementeira, irrigados por subcapilaridade. Foram testados dois substratos comerciais e a semeadura foi realizada em tubetes com 50cm³, tubetes com 120cm³ e bandejas de isopor contendo 72 células com volume de 120cm³. Os seis porta-enxertos cítricos avaliados foram: Trifoliata [Poncirus trifoliata [L.] Raf.]; Flying Dragon [Poncirus trifoliata (L.) Raf. var. monstrosa]; limoeiro Volkameriano (Citrus volkameriana Pasq.), citrangeiro Fepagro C37 [P. trifoliata x Citrus sinensis [L.] Osbeck.], tangerineira Sunki (C. sunki hort. ex Tan.) e citrumeleiro Swingle (P. trifoliata x C. paradisi). Avaliou-se emergência, altura e diâmetro das plantas ao longo do cultivo em casa de vegetação. Em laboratório, avaliou-se massa fresca e seca da parte aérea e raiz, número de folhas, área foliar por folha e área foliar por planta. Nas avaliações de emergência de plântulas, a tangerineira Sunki, o limoeiro Volkameriano e o citrumeleiro Swingle apresentaram maiores taxas em relação ao Trifoliata, ao citrangeiro Fepagro C 37 e ao Flying Dragon. Ao empregar-se o sistema de irrigação por subcapilaridade, o substrato comercial 1 é recomendado para todos recipientes. O substrato comercial 2 somente deve ser empregado em bandejas alveoladas de 120 cm³.(AU)

In the production of citrus seedling, the knowledge of rootstock substrate and container is essential to define the entire substantial period to produce quality seedling. The objective of this research was to evaluate seedling emergence and vegetative development of six citrus rootstocks grown on two substrates and kept in different containers at the stage of sowing irrigated by capillarity. Two commercial substrates were tested and seeding was performed in three containers: stiff plastic tubes with 50cm³, stiff plastic tubes with 120cm³ and polystyrene trays containing 72 cells with a volume of 120cm³. The six rootstocks citrus evaluated were: Trifoliata [Poncirus trifoliata [L.] Raf.]; Flying Dragon [Poncirus trifoliata (L.) Raf. var. monstrosa]; Volkameriano lemon (Citrus volkameriana Pasq.), Fepagro C37 citrange [P. trifoliata x Citrus sinensis [L.] Osbeck.], Sunki tangerine (C. sunki hort. ex Tan.) and Swingle citrumelo (P. trifoliata x C. paradisi). The emergence, height and diameter of plants in the greenhouse were evaluated. Fresh weight, root and shoot dry weight, leaf number, leaf area per plant and leaf area per leaf were evaluated in the laboratory. In the evaluations of emergence of seedlings, the Sunki tangerine, Volkameriano lemon and Swingle citrumelo had higher rates compared to Trifoliata, Fepagro C37 citrange and Flying Dragon. When the system in a floating irrigation system, commercial substrate 1 is recommended for all containers. The commercial substrate 2 should be only used in alveolate trays of 120cm³.(AU)

Adequacy and diagnostic accuracy of aspiration vs. capillary fine needle thyroid biopsies.

Thyroid nodules can be biopsied by fine needle aspiration (FNA) or fine needle capillary (FNC) biopsies. However, there is controversy on whether one technique is superior to another. In a randomized cytopathologist-blinded cross-sectional study, 260 patients (238 females, age 43.2 +/- 12.6) with nodular (82.7%) and diffuse goiter (17.3%) underwent 520 FNAs and 520 FNCs (not guided by ultrasound). Smears were scored for sample adequacy, and diagnosed as malignant, benign, suspicious, or nondiagnostic. Diagnostic accuracy was calculated based on the histological findings of 58 patients submitted to surgery. Intra-technique diagnostic accuracy and sample adequacy was seen in all samples. FNA and FNC provided similar cytological diagnosis, respectively (benign: 75.8% vs. 74.2%, p = 0.600; malignant: 3.8% vs. 3.8%, p = 0.871; suspicious: 10.4% vs. 10.8%, p = 0.913; and nondiagnostic: 10.0% vs. 11.2%, p = 0.598). Adequacy scores were similar by FNA (7.94 +/- 2.84) and FNC (7.96 +/- 2.81, p = 0.909). The same proportion of adequate or superior samples was seen in both techniques (91.6%). Sensitivity was equal to 85.7% for FNA and 100% for FNC. Similarly, specificity was 100% for both techniques. FNA and FNC provide the similar sample adequacy and diagnostic accuracy. The choice of technique should be based on the operator's personal preferences and experience.

The deacetylation reaction in Eucalyptus wood: kinetics and effects on the effective diffusion.

The removal of native acetyl groups from hardwood O-acetyl-glucuronoxylan has a strong effect on physical characteristics, accessibility and structure of this polymer. The removal also has effects on the swelling and ion transport capacity of the cell wall of hardwoods. In this work, a kinetic expression for Eucalyptus wood deacetylation is determined. Two liquid mediums are considered: a simple alkaline one and another with a higher sodium concentration. The kinetic expression is a power law for the acetyl content and the concentrations in the liquid medium dependence, and is an Arrhenius type expression for temperature dependence. The kinetic expression can be useful to predict the physical properties of wood since the analysis of deacetylation effects on effective capillarity (ECCSA) shows that the acetyl content is a determining factor of wood ionic transport capacity.

Comparacion entre la tecnica de capilaridad y la biopsia aspiracion con aguja fina (BACAF) en nodulos de tiroides / Comparison between capillary technique and fine-needle aspiration biopsy (BACAF) in thyroid nodules

La biopsia aspiración con aguja fina de tiroides es el examen de elección en los nódulos tiroideos. Se realizó un estudio en el cual se comparó la técnica de capilaridad con la biopsia por aspiración con aguja fina (BACAF) en lesiones de tiroides.Se efectuaron en total 50 biopsias de tiroides. Sc encontró que los resultados de los extendidos citológicos preparados para cada método fueron comparables en calidad, cantidad y rendimiento diagnóstico. Las dos técnicas tuvieron una adecuada eficacia diagnóstica. Se concluyó que la capilaridad es un excelente método diagnóstico y combinado con el bacaf mejora la sensibilidad diagnóstica.

The thyroid Fine-Needle Aspiration Biopsy is the test of choice for thyroid nodules. We carried out a study to compare the Capillarity technique versus Fine-Needle Aspiration Biopsy (FNAB) in thyroid lesions. We performed 50 thyroid biopsies. We found that the results of the cytology smears prepared for cach technique were comparable in qualit, amount and diagnostic reward. Both techniques had an adequate diagnostic efficacy. We concluded that capillarity, is an excellent diagnostic method and combined with FNAB improves the diagnostic sensitivity.

Dewetting processes in a cylindrical geometry.

Dewetting of liquid films of water-glycerol solutions of different viscosities has been studied experimentally in PVC cylindrical tubes. In contrast with plane surfaces, the dewetting capillary number Ca(vd) increases with the film thickness ho over a large part of the experimental range and follows a same global trend independent of viscosity as a function of ho. This increase is only partly explained by variations of the capillary driving force predicted in a recent theoretical work for a cylindrical geometry. An additional explanation is suggested, based on different spatial distributions of the viscous dissipation in the dewetting bump in the planar and cylindrical geometries. This mechanism is investigated for films of different thicknesses in a numerical model assuming a polynomial variation of the liquid thickness with distance in the bump region.

Evaluación de nódulos tiroídeos mediante punción aspirativa con aguja fina bajo ultrasonido: experiencia en 120 casos / Evaluation of thyroid nodules using ultrasound guided fine needle aspiration biopsy: experience in 120 cases

Los nódulos tiroideos son un problema clínico común, su prevalencia es de un 4 a 7 por ciento. La mayoría son benignos, pero alrededor de un 0,1 a 20 por ciento son malignos. La PAAF guíada por ultrasonido nos permite seleccionar aquellos nódulos que requieren cirugía con un alto grado de sensibilidad y especificidad evitando procedimientos innecesarios y costosos. El propósito del estudio es establecer la eficacia del método, determinando la incidencia de cáncer en la población estudiada y los parámetros técnicos mas adecuados que permitan una punción óptima

Evaluación de una técnica capilar modificada para inmunocitoquímica en cultivos adheridos a cubreobjetos de vidrio / Evaluation of a modified capillary technique for immunocytochemistry of coverslip adhered cultures

Con el objeto de evaluar una técnica inmunocitoquímica para cultivos celulares adheridos a cubreobjetos, se ensayó una modificación de la técnica capilar comparándola con la técnica convencional (en cajas de 24 pozos). Cultivos de ganglio de raíz dorsal de raton adulto se sometieron a inmunodetección por peroxidasa e inmunofluorescencia de neurofilamento, proteína S-100 y virus de la rabia; la especificidad e intensidad de la marca con una u otra técnica no cambió. El uso de la técnica capilar modificada significó un ahorro de 92 por ciento en los volúmenes de anticuerpos y reactivos usados, sin sacrificar los patrones de marca, sin incrementar el tiempo del procedimiento y usando materiales que corrientemente se encuentran en cualquier laboratorio

Fluid pressure and fibrinolytic activity in implanted subcutaneous and intramuscular capsules.

Using the capsule implantation method, the relationship between the intracapsular fluid pressure (IFP) and fibrinolytic activity of the intracapsular fluid was examined in subcutaneous and intramuscular capsules. When IFP was positive, the sterility test was positive (indicating infection), the fibrinolytic activity was enhanced, and the response of IFP to volume change or hypertonic solutions was poor. On the other hand, when IFP was negative, the sterility test was negative, the fibrinolytic activity was weak, and the response of IFP to volume change or hypertonic solutions was good. Also, the more negative the IFP, the weaker was the fibrinolytic activity in the intracapsular fluid (r = 0.60, p less than 0.01). The ratio of the intracapsular fluid fibrinolytic activity to the plasma fibrinolytic activity showed a good correlation to the intracapsular fluid pressure (r = 0.68, p less than 0.01). When the fibrinolytic activity was activated by injection of streptokinase and human plasma, the IFP showed a tendency to increase. These results suggest that the fibrinolytic system plays some role in the maintenance of local fluid balance.