Search

Supplemental Digital Content is available in the text

A coating of poly(dimethylsiloxane) (PDMS) on a stir bar is typically used for sorptive extraction and preconcentration of nonpolar organic analytes from aqueous matrices. Here, we used sol–gel to synthesize three new coatings based on hydroxy-terminated PDMS crosslinked with 3-cyanopropyltriethoxysilane (CN) and phenyltriethoxysilane (PH) with three molar ratios of CN:PH (2:1, 1:1, and 1:2). The water contact angle of the coatings was below 90°. Cyanopropyl and phenyl groups were identified by infrared spectroscopy. The coatings were thermally stable up to 200°C. Also, they were stable to organic solvents and aqueous solutions at different pH. Glass stir bars were covered with the coatings to explore its potential application in stir-bar sorptive extraction. The test included polar antibiotics (sulfathiazole, sulfamethoxazole, trimethoprim, and chloramphenicol) dissolved in spiked water (pH 4.5) and organic solvent. Different experimental conditions were used to explore the capacity of the coatings to extract and preconcentrate the antibiotics. Unsatisfactory results of enrichment effect were obtained in aqueous solutions of antibiotics. In organic medium, the antibiotics were extracted and preconcentrated with the three coatings.

The main aim of this work is to manufacture a composite material based on a natural material (marble) with acceptable mechanical properties and fire resistance, for being used in habitat industry as floor or wall in buildings. Marble used as raw material is the waste powder of quarry or plate manufacturing. To achieve this objective, polyester matrix composites with 50 wt.% of marble and 3 wt.% of glass fiber (short fiber or mesh) were prepared. The novelty of this study is the high percentage of ceramic material added to a polymer matrix composite and the fire resistance study. Samples were characterized mechanically through flexural test, Charpy impact test, compression test and wear resistance by pin-on-disk test. Fracture surfaces were analyzed by scanning electron microscope (SEM), and wear tracks were studied by SEM and 3D optical profilometer. Besides, samples were subjected to fire test using a Bunsen burner at 900 °C for 20 min. Sample temperature at the opposite-to-fire test side was measured with an infrared thermometer. Results show that marble improves mechanical properties of polyester and the effect of the glass fiber depends on its morphology (fiber or mesh). Fire resistance is high, and the fire goes out when the flame is turned off. Furthermore, the mesh maintains the integrity of the sample.

ABSTRACTThis paper analyses the effects on liquidity of voluntary pre-trade anonymity in the trading process. We confirm previous studies showing that market liquidity improves immediately after anonymous trading. Using the daily percentage of effective volume traded anonymously, we show that the anonymity–liquidity relationship presents a non-linear U-shape. We focus on the voluntary concealment of broker identification introduced by the Spanish Stock Exchange in October 2015. We conclude that, in our sample, anonymity increases stock liquidity but at a decreasing rate; when a considerable part of the effective volume is traded anonymously, additional percentages of anonymous trading deteriorates stock liquidity.

Psoriasis is currently considered to be an immune-mediated disease whose patho-mechanisms involve platelet activation, which seems to correlate with the activity of the disease. Platelet activation is associated with the formation of platelet-lymphocyte complexes (PLyC), although their significance remains unknown. Moreover, biological treatments that target tumor necrosis factor-α (TNF-α) reduce platelet activation. To clarify the significance of PLyC, we compared their levels in patients with psoriasis with those of healthy donors and determined whether platelet binding modifies the secretion of IL-17A by T helper cells. Finally, we assessed the effect of anti–TNF-α treatment on PLyC in responder and non-responder patients with psoriasis. Ours results demonstrated an increase in PLyC in patients with psoriasis. Moreover, the percentage of IL-17-secreting cells was observed to be higher in the platelet-lymphocyte complex population, and these cells tended to secrete greater amounts of IL-17A. Psoriasis patients treated with anti–TNF-α normalized platelet-lymphocyte complex values, and the basal percentage of platelet-T helper lymphocyte complexes was significantly higher in the responder group. In conclusion, PLyC are increased in psoriasis patients, and the number of complexes decreases in response to anti–TNF-α treatment, specifically in the responder group of patients. This finding suggests that PLyC are a prognostic biomarker of response to anti–TNF-α therapy, but prospective studies are necessary to verify these results in patients with psoriasis.

Reviewing their experience in 1375 kidney transplant recipients, the authors suggest that IgA anti-beta-2 glycoprotein1 antibodies at time of transplantation is an independent factor of graft loss mainly due to artery and vein thrombosis. Supplemental digital content is available in the text.

Dado el déficit de hígados para trasplante se está potenciando la donación de vivo hepática (DVH) en el ámbito de habla hispana. Para ello es fundamental que los profesionales de centros hospitalarios estén a favor de dicha donación, dado que son una pieza clave en este tratamiento y son un grupo generador de opinión ante la población.

Los profesionales hospitalarios son un colectivo generador de opinión para el resto de la población en temas sanitarios. La actitud no favorable de dicho grupo es un obstáculo hacia el incremento de las tasas de donación de órganos propios de cadáver.

Background The knowledge and acceptance of the concept of brain death (BD) among health care personnel is fundamental.Objective To analyze the level of understanding of the BD concept among personnel in Spanish and Latin American healthcare centers and to determine the factors affecting this attitude.Material and methods Data from 12 hospitals and 32 primary care centers in 4 countries within the International Collaborative Donor Project were selected (Spain, Mexico, Cuba and Costa Rica (n = 4378)).Results 62% of the personnel (n = 2714) understood BD and believed that this was the death of an individual. Of the rest, 30% (n = 1 333) did not understand it and the remaining 8% (n = 331) believed it did not mean the death of a patient. 83% (n = 931) of physicians understood BD, compared to 75% (n = 895) of nurses, 55% (n = 299) of healthcare assistants, 53% (n = 108) of non-healthcare university-educated personnel and 36% (n = 481) of those without a university education (p<0.001). 68% (n = 1084) of Mexicans understood BD compared to 66% (n = 134) of Cubans, 58% (n = 1411) of Spaniards, and 52% (n = 85) (p<0.001) of Costa Ricans. There were significant relationships between knowledge of the concept and the following: type of healthcare center (p<0.001), clinical service (p<0.001), having spoken about organ donation within the family (p<0.001) and one's partner's attitude to the subject (p<0.001). A direct relationship has been found between understanding the concept and attitude toward deceased donation (p<0.001).Conclusions The understanding of BD by personnel from healthcare centers was not as good as expected. There were marked differences depending on job category.

We have explored the effect of antiretroviral drugs on the antiviral immune response in human immunodeficiency virus-1 (HIV-1)–infected patients by using an enzymatic immunosensor that detects epitope-modifying anti-gp41 antibodies. By this molecular sensing approach, we have identified an irreversible impact of drug administration on the functionality of IgG4 and IgM specific antibodies regarding the structural modification promoted on their target epitope. During the antiretroviral therapy, the prevalent induced fit promoted by IgM on the epitope was lost at the expense of that promoted by IgG4, suggesting alternativeness in the neutralization potency of these antibody subpopulations. Because the particular drug composition of the antiretroviral treatment did not affect such immune shift, the obtained data strongly suggest that the drop in the viral load and the consequent lost of antigenemia are responsible for the functional adaptation observed in the humoral response.

This paper examines the macro- and microstructural characteristics of perforating projectiles type Armour Piercing Discarding Sabot (APDS) 20 mm, after being detained by armour plates normally used as defence against projectiles. The effect of impact of these projectiles against high density alumina tiles with several materials of backing plate (steel, alumina and composite) is studied to determine the structural modifications of these projectiles by microhardness and image analysis. The results provide data for studies of simulation of impacts in the design of armour plating.

ABSTRACTHuman immunodeficiency virus type 1 (HIV-1) resistance to antiretroviral drugs is the main cause of patient treatment failure. Despite the problems associated with interpretation of HIV-1 resistance testing, resistance monitoring should help in the rational design of initial or rescue antiretroviral therapies. It has previously been shown that the activity of the HIV-1 protease can be monitored by using a bacteriophage lambda-based genetic assay. This genetic screening system is based on the bacteriophage lambda regulatory circuit in which the viral repressor cI is specifically cleaved to initiate the lysogenic to lytic switch. We have adapted this simple lambda-based genetic assay for the analysis of the activities and phenotypes of different HIV-1 proteases. Lambda phages that encode HIV-1 proteases either from laboratory strains (strain HXB2) or from clinical samples are inhibited in a dose-dependent manner by the HIV-1 protease inhibitors indinavir, ritonavir, saquinavir, and nelfinavir. Distinct susceptibilities to different drugs were also detected among phages that encode HIV-1 proteases carrying different resistance mutations, further demonstrating the specificity of this assay. Differences in proteolytic processing activity can also be directly monitored with this genetic screen system since two phage populations compete in culture with each other until one phage outgrows the other. In summary, we present here a simple, safe, and rapid genetic screening system that may be used to predict the activities and phenotypes of HIV-1 proteases in the course of viral infection and antiretroviral therapy. This assay responds appropriately to well-known HIV-1 protease inhibitors and can be used to search for new protease inhibitors.

The emergence of genotypic resistance in protease and reverse transcriptase (RT) gene regions was longitudinally evaluated in plasma samples from a group of 12 HIV‐1–infected patients treated with different combination of antiretroviral therapies and selected on the basis of their clinical failure. Complex mutational patterns in the reverse transcriptase gene were observed. In particular, combinations of AZT (41L, 67N, 70R, 210W, and 219Q/E) and 3TC (184M) were seen in 10 patients. Two patients presented codon 151 multinucleoside analogue resistance (MNR). Additionally, seven patients harbored RT nonnucleoside analogue‐related resistance substitutions (98G, 103N, and 181C). Multiple protease‐selected mutations were found in each patient with an average of six substitutions per patient, with 10I/F/V, 63P, 71V, 82A/T, 84V, and 90M being the most prevalent substitutions. Overall, these results showed that for most patients virological failure was coupled with detectable genotypic resistance. Furthermore, most patients exhibited genotypic resistance to almost all available anti–HIV‐1 drugs. The high viral loads found in most patients at the end of the study suggest that the replication of these multidrug resistant viruses are not severely compromised. Phylogenetic analysis of these polsequences revealed that a specific HIV‐1 genotype prone to develop multidrug resistance was not found. J. Med. Virol. 59:480–490, 1999. © 1999 Wiley‐Liss, Inc.

We observed that some patients do not develop hypoalbuminemia despite the presence of massive proteinuria. To investigate whether the absence or presence of hypoalbuminemia could be a marker in the distinction between idiopathic focal segmental glomerulosclerosis (FSG) and FSG secondary to hyperfiltration, we reviewed all our patients with biopsy-proven FSG and persistent nephrotic-range proteinuria (3.5 g/24 h). Patients who met these conditions were then separated into those with hypoalbuminemia (serum albumin level <3 g/dL; group I; n = 19) and those with normoalbuminemia (3.5 g/24 h; group II; n = 18). All group I patients had nephrotic edema in contrast with the absence of edema in all group II patients. Serum cholesterol and triglyceride levels were significantly greater in group I. All group I patients had been diagnosed with idiopathic FSG. The diagnoses of group II patients were FSG secondary to massive obesity in eight patients (44%), vesicoureteral reflux in five patients (27%), and renal mass reduction in three patients (16%); only two patients (11%) in this group had idiopathic FSG. The case histories of 19 other patients with nephrotic-range proteinuria associated with hyperfiltering disorders (reflux nephropathy, massive obesity, renal mass reduction), but without renal biopsy, were also reviewed; despite massive proteinuria (5.8 ± 3.1 g/24 h), serum albumin and total protein levels were always within normal values. In conclusion, patients with FSG secondary to hyperfiltration do not develop hypoalbuminemia or the other characteristic complications of nephrotic syndrome, despite the presence of massive proteinuria values.

The development of new antiretroviral agents may improve survival of HIV‐infected individuals, and therefore chronic viral hepatitis may become more relevant in these patients. The presence of GBV‐C/HGV and hepatitis C virus (HCV) RNA were investigated by reverse transcriptase‐nested polymerase chain reaction in plasma from 168 Spanish HIV‐infected patients belonging to four different risk groups: intravenous drug users (IVDUs), hemophiliacs, homosexuals, and heterosexuals. GBV‐C/HGV‐RNA and HCV‐RNA were detected in 18% and 43% of the patients, respectively. The prevalence of current infection with these viruses was notably high, 19% for GBV‐C/HGV and 69% for HCV, among individuals with parenteral risk of infection (intravenous drug abusers and hemophiliacs), but sexual transmission with GBV‐C/HGV was also suggested because 16.5% of patients with sexual risk, either homosexual or heterosexual, had GBV‐C/HGV‐RNA in plasma. Although investigation of GBV‐C/HGV‐RNA possibly underestimates the actual prevalence of infection with GBV‐C/HGV, the above data suggest that sexual contact may play a relevant role in the spread of this virus. Phylogenetic analysis showed no evidence for clustering of NS3 sequences into different genotypes or subtypes of GBV‐C/HGV. J. Med. Virol. 55:293–299, 1998. © 1998 Wiley‐Liss, Inc.

Collapsing glomerulopathy is a pattern of renal injury that is seen in association with human immunodeficiency virus (HIV) infection. Patients with this HIV-associated nephropathy (HIVAN) present nephrotic syndrome and rapid deterioration of the renal function. There is no proven effective therapy for HIVAN, and the majority of the patients become dialysis dependent. We report a case of biopsy-proven HIVAN that showed spontaneous improvement of the renal function.