Protective Effect of Curcumin on D-Galactose-Induced Senescence and Oxidative Stress in LLC-PK1 and HK-2 Cells.

D-galactose has been widely used as an inducer of cellular senescence and pathophysiological processes related to aging because it induces oxidative stress. On the other hand, the consumption of antioxidants such as curcumin can be an effective strategy to prevent phenotypes related to the enhanced production of reactive oxygen species (ROS), such as aging and senescence. This study aimed to evaluate the potential protective effect of curcumin on senescence and oxidative stress and endoplasmic reticulum stress induced by D-galactose treatment in Lilly Laboratories Culture-Porcine Kidney 1 (LLC-PK1) and human kidney 2 (HK-2) proximal tubule cell lines from pig and human, respectively. For senescence induction, cells were treated with 300 mM D-galactose for 120 h and, to evaluate the protective effect of the antioxidant, cells were treated with 5 µM curcumin for 24 h and subsequently treated with curcumin + D-galactose for 120 h. In LLC-PK1 cells, curcumin treatment decreased by 20% the number of cells positive for senescence-associated (SA)-ß-D-galactosidase staining and by 25% the expression of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and increased by 40% lamin B1 expression. In HK-2 cells, curcumin treatment increased by 60% the expression of proliferating cell nuclear antigen (PCNA, 50% Klotho levels, and 175% catalase activity. In both cell lines, this antioxidant decreased the production of ROS (20% decrease for LLC-PK1 and 10 to 20% for HK-2). These data suggest that curcumin treatment has a moderate protective effect on D-galactose-induced senescence in LLC-PK1 and HK-2 cells.

Isoliquiritigenin pretreatment regulates ER stress and attenuates cisplatin-induced nephrotoxicity in male Wistar rats.

Cisplatin (CP) is a chemotherapeutic drug used to treat solid tumors. However, studies have revealed its nephrotoxic effect. Oxidative stress, endoplasmic reticulum (ER) stress, and mitochondrial dysfunction are involved in CP-induced renal damage. Thus, preconditioning (hormetic effect) of ER stress is a strategy to prevent CP-induced renal damage. On the other hand, isoliquiritigenin (IsoLQ) is recognized as a flavonoid with antioxidant properties and an inducer of ER stress. Therefore, we evaluated the ER stress-inducing capacity of IsoLQ and its possible protective effect against CP-induced nephrotoxicity in adult male Wistar rats. The findings reflected that IsoLQ pretreatment might decrease renal damage by reducing plasma creatinine and blood urea nitrogen levels in animals with CP-induced nephrotoxicity. These may be associated with IsoLQ activating ER stress and unfolded protein response (UPR). We found increased messenger RNA levels of the ER stress marker glucose-related protein 78 kDa (GRP78). In addition, we also found that pretreatment with IsoLQ reduced the levels of CCAAT/enhancer-binding protein-homologous protein (CHOP) and X-box-binding protein 1 (XBP1) in the renal cortex, reflecting that IsoLQ can regulate the UPR and activation of the apoptotic pathway. Moreover, this preconditioning with IsoLQ of ER stress had oxidative stress-regulatory effects, as it restored the activity of glutathione peroxidase and glutathione reductase enzymes. Finally, IsoLQ modifies the protein expression of mitofusin 2 (Mfn-2) and voltage-dependent anion channel (VDAC). In conclusion, these data suggest that IsoLQ pretreatment has a nephroprotective effect; it could functionally regulate the ER and mitochondria and reduce CP-induced renal damage by attenuating hormesis-mediated ER stress.

Occurrence of extended-spectrum ß-lactamase-producing Enterobacteriaceae in raw milk from cows with subclinical mastitis in northeast Brazil.

Extended-spectrum ß-lactamase (ESBL)-producing Gram negative bacteria are becoming increasingly important in veterinary and human medicine because they can hydrolyze the third generation ß-lactams, penicillins, and monobactams. The aim of this study was to identify ESBL-producing Enterobacteriaceae in raw cow milk samples from northeast Brazil. Twenty-six bacterial isolates belonging to the Enterobacteriaceae family were obtained from milk samples from 257 cows with subclinical mastitis. Using microbiological tests, 53.85% (14/26) were identified as Escherichia coli, 15.38% (4/26) as Proteus mirabilis, 26.92% (7/26) as Klebsiella spp., and 3.85% (1/26) as Citrobacter spp. Of all the isolates, 61.54% (16/26) were positive in the ESBL screening test, of which 12.5% (2/16) were positive in the double-disc synergy test using three types of cephalosporins and amoxicillin/clavulanic acid. The two isolates were identified as Klebsiella spp. Among all the isolates, 53.85% (14/26) were positive for one or both ESBL-encoding genes, blaSHV and blaTEM; among these, 71.43% (10/14) were identified as E. coli. This study demonstrates that ESBL-producing bacteria can be found in raw cow milk from northeast Brazil. Cows with subclinical mastitis should be recognized as reservoirs of these strains, which can propagate to humans.

Antimicrobial Activity of Spices Popularly Used in Mexico against Urinary Tract Infections.

Urinary tract infections (UTIs) are the most common infectious diseases worldwide. These infections are common in all people; however, they are more prevalent in women than in men. The main microorganism that causes 80-90% of UTIs is Escherichia coli. However, other bacteria such as Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Proteus mirabilis, and Klebsiella pneumoniae cause UTIs, and antibiotics are required to treat them. However, UTI treatment can be complicated by antibiotic resistance and biofilm formation. Therefore, medicinal plants, such as spices generally added to foods, can be a therapeutic alternative due to the variety of phytochemicals such as polyphenols, saponins, alkaloids, and terpenes present in their extracts that exert antimicrobial activity. Essential oils extracted from spices have been used to demonstrate their antimicrobial efficacy against strains of pathogens isolated from UTI patients and their synergistic effect with antibiotics. This article summarizes relevant findings on the antimicrobial activity of cinnamon, clove, cumin, oregano, pepper, and rosemary, spices popularly used in Mexico against the uropathogens responsible for UTIs.

Antioxidants affect endoplasmic reticulum stress-related diseases.

The endoplasmic reticulum (ER) is a complex multifunctional organelle that maintains cell homeostasis. Intrinsic and extrinsic factors alter ER functions, including the rate of protein folding that triggers the accumulation of misfolded proteins and alters homeostasis, thus generating stress in the ER, which activates the unfolded protein response (UPR) pathway to promote cell survival and restore their homeostasis; however, if the damage is not corrected, it could also trigger cell death. In addition, ER stress and oxidative stress are closely related because excessive production of reactive oxygen species (ROS), a well-known inducer of ER stress, promotes the accumulation of misfolded proteins; at the same time, the ER stress enhances ROS production, generating a pathological cycle. Furthermore, it has been described that the dysregulation of the UPR contributes to the progression of various diseases, so the use of compounds capable of regulating ER stress, such as antioxidants, has been used in several experimental models of diseases to alleviate the damage induced by the maladaptive signaling of the UPR, the mechanism of action of antioxidants generally is dose-dependent, and it is specific in each tissue and pathology, could decrease or enhance specific proteins of the UPR to have beneficial or detrimental effects.

Effect of nanocellulose polymorphism on electrochemical analytical performance in hybrid nanocomposites with non-oxidized single-walled carbon nanotubes.

Two cellulose nanocrystals/single-walled carbon nanotube (CNC/SW) hybrids, using two cellulose polymorphs, were evaluated as electrochemical transducers: CNC type I (CNC-I/SW) and CNC type II (CNC-II/SW). They were synthesized and fully characterized, and their analytical performance as electrochemical sensors was carefully studied. In comparison with SWCNT-based and screen-printed carbon electrodes, CNC/SW sensors showed superior electroanalytical performance in terms of sensitivity and selectivity, not only in the detection of small metabolites (uric acid, dopamine, and tyrosine) but also in the detection of complex glycoproteins (alpha-1-acid glycoprotein (AGP)). More importantly, CNC-II/SW exhibited 20 times higher sensitivity than CNC-I/SW for AGP determination, yielding a LOD of 7 mg L-1.These results demonstrate the critical role played by nanocellulose polymorphism in the electrochemical performance of CNC/SW hybrid materials, opening new directions in the electrochemical sensing of these complex molecules. In general, these high-active-surface hybrids smartly exploited the preserved non-oxidized SW conductivity with the high aqueous dispersibility of the CNC, avoiding the use of organic solvents or the incorporation of toxic surfactants during their processing, making the CNC/SW hybrids promising nanomaterials for electrochemical detection following greener approaches.

Evaluation of Uroflowmetry Curve Patterns and Nomogram Construct in Healthy Nulliparous Female Adults.

OBJECTIVE: The aims of the study were to construct uroflowmetry nomograms, evaluate uroflowmetry flow rate patterns, and graphically illustrate overlaid uroflowmetry curves in nulliparous female adult volunteers. METHODS: We performed a prospective cross-sectional study evaluating uroflowmetry curve and flow rate patterns on a cohort of nulliparous female adult volunteers. Primary outcome was construction of uroflowmetry maximum and average flow rate nomograms. Secondary outcomes included evaluation of uroflowmetry flow rate patterns and graphical illustrations of overlaid uroflowmetry curves. Uroflowmetry printouts were overlaid and used to create a model of uroflow patterns, and nomogram curves were analyzed in 5 groups based on voided volumes. RESULTS: We enrolled 164 participants and 158 had voided volumes between 50 mL and 800 mL. Participants' mean age and body mass index were 25 years and 23, respectively. Maximum and average flow rate nomograms were created, and analysis of uroflow parameters was performed. Median voided volume was 241 mL (149-431 mL), the median maximum flow was 29 mL/s (20-38 mL/s), and the median average flow was 15 mL/s (10-19 mL/s). Participants were divided into 5 groups based on voided volumes. The nomogram patterns for each voided volume group were visually different from typical nomogram patterns. CONCLUSIONS: Uroflowmetry curves and flow rates vary significantly according to voided volume. Our study suggests that in normal healthy nulliparous female adults there is likely a broader range of normal flow rates and uroflowmetry curves than what has been previously reported. Further research is needed to investigate the accuracy of these finding.

Investigation of soil contaminated with Toxoplasma gondii oocyst in urban public environment, in Brazil.

In this study, we determined the occurrence of Toxoplasma gondii oocysts in soil samples from public places. A total of 120 samples were collected from 24 sites, including squares, parks, university, hospitals in the city of Recife. The recovered oocysts were subjected to a nested-PCR test, and nine sites (9/24) were found to be positive for gene of apicomplexan parasites. The PCR product was sequenced, and 8.33% (10/120) of the samples showed 100% similarity to T. gondii DNA. T. gondii oocysts were detected in 75% (3/4) of the evaluated hospital soil samples and in 23.81% (5/21) soils samples from the public squares and parks. The results of this study demonstrate the potential of the soil in the areas analyzed as a source of T. gondii infection and therefore highlight the importance of devising educational strategies on the use of these sites, in addition to future cleaning protocols in public areas.

Pump-Free Microfluidic Device for the Electrochemical Detection of α1-Acid Glycoprotein.

α1-Acid glycoprotein (AGP) is a glycoprotein present in serum, which is associated with the modulation of the immune system in response to stress or injuries, and a biomarker for inflammatory diseases and cancers. Here, we propose a pump-free microfluidic device for the electrochemical determination of AGP. The microfluidic device utilizes capillary-driven flow and a passive mixing system to label the AGP with the Os (VI) complex (an electrochemical tag) inside the main channel, before delivering the products to the electrode surface. Furthermore, thanks to the resulting geometry, all the analytical steps can be carried out inside the device: labeling, washing, and detection by adsorptive transfer stripping square wave voltammetry. The microfluidic device exhibited a linear range from 500 to 2000 mg L-1 (R2 = 0.990) and adequate limit of detection (LOD = 231 mg L-1). Commercial serum samples were analyzed to demonstrate the success of the method, yielding recoveries around 83%. Due to its simplicity, low sample consumption, low cost, short analysis time, disposability, and portability, the proposed method can serve as a point-of-care/need testing device for AGP.

Backstage players of fibrosis: NOX4, mTOR, HDAC, and S1P; companions of TGF-ß.

The fibrotic process could be easily defined as a pathological excess of extracellular matrix deposition, leading to disruption of tissue architecture and eventually loss of function; however, this process involves a complex network of several signal transduction pathways. Virtually almost all organs could be affected by fibrosis, the most affected are the liver, lung, skin, kidney, heart, and eyes; in all of them, the transforming growth factor-beta (TGF-ß) has a central role. The canonical and non-canonical signal pathways of TGF-ß impact the fibrotic process at the cellular and molecular levels, inducing the epithelial-mesenchymal transition (EMT) and the induction of profibrotic gene expression with the consequent increase in proteins such as alpha-smooth actin (α-SMA), fibronectin, collagen, and other extracellular matrix proteins. Recently, it has been reported that some molecules that have not been typically associated with the fibrotic process, such as nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (NOX4), mammalian target of rapamycin (mTOR), histone deacetylases (HDAC), and sphingosine-1 phosphate (S1P); are critical in its development. In this review, we describe and discuss the role of these new players of fibrosis and the convergence with TGF-ß signaling pathways, unveiling new insights into the panorama of fibrosis that could be useful for future therapeutic targets.

Electrochemical sensor for the assessment of carbohydrate deficient transferrin: Application to diagnosis of congenital disorders of glycosilation.

Carbohydrate deficient transferrin (CDT) is used as biomarker of different health problems as, for example, congenital disorders of glycosylation (CDG). We propose a screen-printed-based electrochemical sensor for the determination of carbohydrate deficient transferrin using an Os (VI) tag-based electrochemistry. When transferrin is labeled with Os (VI) complex, it generates two voltammetric signals: one from carbohydrates (electrochemical signal of osmium (VI) complex at -0.9 V/Ag) and one from the amino acids present in glycoprotein (intrinsic electrochemical signal of glycoprotein at +0.8 V/Ag). The relationship between the two analytical signals (carbohydrate signal/protein signal) is an indicator of the degree of glycosylation (electrochemical index of glycosylation), which has shown an excellent correlation (r = 0.990) with the official parameter %CDT obtained by CE-UV. The suitability of this approach was demonstrated by analyzing serum samples from CDG patients.

The Effect of Phenazopyridine on Immediate Postoperative Voiding After Prolapse Surgery: A Randomized Controlled Trial.

OBJECTIVES: The objective of our study was to determine if phenazopyridine reduces void trial (VT) failure rates after prolapse surgery. METHODS: A single-institution randomized controlled trial was conducted comparing a second dose of phenazopyridine 200 mg on postoperative day 1 versus no additional phenazopyridine in women undergoing prolapse surgery. All subjects (including controls) received 200 mg of phenazopyridine preoperatively for ureteral patency verification. The intervention group received a second dose of phenazopyridine 200 mg the morning of postoperative day 1. The primary outcome was assessed using a standardized VT. Secondary outcomes included pain, opioid usage, urinary tract infections, and prolonged or recurrent urinary retention. An intent-to-treat analysis was performed with a χ2 test to compare failure rates between the intervention and control groups. RESULTS: We enrolled 152 women, and 76 were randomized to each group. There was no difference in VT failures between the 2 groups-34% failed without phenazopyridine on postoperative day 1, and 42% failed with phenazopyridine on postoperative day 1 (P = 0.326). Subject characteristics were similar across both groups. Pain scores immediately before the VT were 3 out of 10 in both groups (P = 0.206), with no difference in opioid consumption (P = 0.750). There were no differences in the rate of urinary tract infections or prolonged or recurrent urinary retention between the groups (P = 0.304 and P = 0.745). CONCLUSIONS: While previous studies suggested an improvement in immediate postoperative voiding with phenazopyridine, our randomized controlled trial does not support this.

Effect of Pudendal Blockade on Bladder Emptying After Midurethral Sling: A Randomized Controlled Trial.

OBJECTIVES: To evaluate the effect of bilateral pudendal nerve blockade on immediate postoperative bladder emptying after midurethral sling. METHODS: We performed a double-blinded, randomized, placebo-controlled trial of women undergoing a midurethral sling procedure between October 2017 and February of 2019. Women older than 18 years were eligible if they were undergoing a midurethral sling with no concomitant procedures and had no preoperative urinary retention. Participant demographics and medical conditions that may affect bladder emptying were recorded preoperatively. Participants were randomized to a bilateral pudendal injection of either bupivacaine or normal saline. After induction of anesthesia, the pudendal injection was administered before any incisions. No other local anesthesia was used. The primary outcome was the rate of passing a standardized void trial. Secondary outcomes included perioperative pain scores, analgesia use, and complications. RESULTS: Ninety-one participants were enrolled in the study. One patient had a delayed void trial on postoperative day 1, leaving 90 participants for the final analysis. Demographic and perioperative characteristics were similar between the groups. Adjusted logistic regression showed that the administration of a bupivacaine pudendal block led to a higher rate of void trial failure (43% vs 20%, odds ratio = 0.32, P = 0.02 adjusted for age, body mass index, and comorbidities). Postoperative pain scores and analgesia use were similar between the groups. Postoperative complications, including urinary tract infection, mesh erosion, pelvic hematoma, or urinary retention within 6 weeks were similar between the groups. CONCLUSIONS: Our prospective trial demonstrates that a bilateral pudendal blockade before midurethral sling procedure worsens postoperative bladder emptying.

Satisfaction With Telephone Versus In-Person Interpretation Services in Limited English-Proficient Urogynecology Patients: A Randomized Controlled Trial.

OBJECTIVE: The objective of this study was to determine if in-person interpreters improve patient satisfaction scores compared with phone interpreters for urogynecology office visits in limited English proficient (LEP) patients. METHODS: Portuguese and Spanish LEP subjects were randomized to phone or in-person interpreter, and a 14-item questionnaire was administered with 3 subscales assessing the primary outcome of patient satisfaction with the interpreter, physician, and nursing. Subject demographics, English proficiency, overall health status, and yearly household income were recorded. Sample size calculations indicated that a mean difference of 12 in satisfaction scores could be detected with 44 subjects per arm. Analysis was conducted using descriptive statistics, and comparisons between the intervention versus control group were analyzed using Fisher exact test, Wilcoxon rank sum test, and linear regression. RESULTS: We enrolled and randomized 106 subjects, and 82 subjects completed the study. There was a statistically significant difference in subject satisfaction between randomization groups, favoring in-person interpreters. In the as-treated analysis, the median satisfaction score for the phone interpreter group was 92.9 and 100 for in-person interpreter group (P < 0.001). Linear regression adjusted for English proficiency showed that there was a difference between median scores of 7.14 (P = 0.002). CONCLUSIONS: Portuguese and Spanish LEP patients experienced higher satisfaction scores for urogynecology office visits when in-person interpreters are used compared with a phone interpreter. Although we found a statistically significant difference between these groups, the clinical significance of our finding is less clear. This topic should continue to be investigated for the field of urogynecology and further studies are needed.

Isoliquiritigenin Pretreatment Induces Endoplasmic Reticulum Stress-Mediated Hormesis and Attenuates Cisplatin-Induced Oxidative Stress and Damage in LLC-PK1 Cells.

Isoliquiritigenin (IsoLQ) is a flavonoid with antioxidant properties and inducer of endoplasmic reticulum (ER) stress. In vitro and in vivo studies show that ER stress-mediated hormesis is cytoprotective; therefore, natural antioxidants and ER stress inducers have been used to prevent renal injury. Oxidative stress and ER stress are some of the mechanisms of damage involved in cisplatin (CP)-induced nephrotoxicity. This study aims to explore whether IsoLQ pretreatment induces ER stress and produces hormesis to protect against CP-induced nephrotoxicity in Lilly Laboratories Cell-Porcine Kidney 1 (LLC-PK1) cells. During the first stage of this study, both IsoLQ protective concentration and pretreatment time against CP-induced toxicity were determined by cell viability. At the second stage, the effect of IsoLQ pretreatment on cell viability, ER stress, and oxidative stress were evaluated. IsoLQ pretreatment in CP-treated cells induces expression of glucose-related proteins 78 and 94 kDa (GRP78 and GRP94, respectively), attenuates CP-induced cell death, decreases reactive oxygen species (ROS) production, and prevents the decrease in glutathione/glutathione disulfide (GSH/GSSG) ratio, free thiols levels, and glutathione reductase (GR) activity. These data suggest that IsoLQ pretreatment has a moderately protective effect on CP-induced toxicity in LLC-PK1 cells, through ER stress-mediated hormesis, as well as by the antioxidant properties of IsoLQ.

Mitochondrial dysfunction and endoplasmic reticulum stress in the promotion of fibrosis in obstructive nephropathy induced by unilateral ureteral obstruction.

Obstructive nephropathy favors the progression to chronic kidney disease (CKD), a severe health problem worldwide. The unilateral ureteral obstruction (UUO) model is used to study the development of fibrosis. Impairment of renal mitochondria plays a crucial role in several types of CKD and has been strongly related to fibrosis onset. Nevertheless, in the UUO model, the impairment of mitochondria, their relationship with endoplasmic reticulum (ER) stress induction and the participation of both to induce the fibrotic process remain unclear. In this review, we summarize the current information about mitochondrial bioenergetics, redox dynamics, mitochondrial mass, and biogenesis alterations, as well as the relationship of these mitochondrial alterations with ER stress and their participation in fibrotic processes in UUO models. Early after obstruction, there is metabolic reprogramming related to mitochondrial fatty acid ß-oxidation impairment, triggering lipid deposition, oxidative stress, (calcium) Ca2+ dysregulation, and a reduction in mitochondrial mass and biogenesis. Mitochondria and the ER establish a pathological feedback loop that promotes the impairment of both organelles by ER stress pathways and Ca2+ levels dysregulation. Preserving mitochondrial and ER function can prevent or at least delay the fibrotic process and loss of renal function. However, deeper understanding is still necessary for future clinically-useful therapies.

Natural antioxidants' effects on endoplasmic reticulum stress-related diseases.

Endoplasmic reticulum (ER) stress is a normal molecular process induced by the over-accumulation of misfolded or unfolded proteins. ER stress induces the unfolded protein response (UPR), which reduces global protein synthesis, increases ER capacity and protein degradation, to restart ER homeostasis, allowing cell survival. However, the over-induction of UPR can also trigger inflammatory processes, tissue damage and cell death. ER stress is involved in several pathologies, like endothelial dysfunction, diabetes and heart, liver, kidney or neurological diseases. Although the progression of these diseases is the result of several pathological mechanisms, oxidative stress has been widely related to these pathologies. Moreover, ER stress can establish a progressive pathological cycle with oxidative stress. Therefore, the use of natural antioxidants, able to modulate both oxidative and ER stress, can be a new strategy to mitigate these diseases. This review is focused on the effects of natural antioxidant compounds on ER stress in endothelial dysfunction, diabetes and heart, liver, kidney or neurological diseases.

Accuracy of Bladder Scanner for the Assessment of Postvoid Residual Volumes in Women With Pelvic Organ Prolapse.

OBJECTIVES: The aim of the study was to evaluate the accuracy of the bladder scanner in assessing postvoid residual (PVR) volumes in patients with pelvic organ prolapse (POP). METHODS: We performed a prospective parallel cohort study evaluating the accuracy of the BVI 3000 bladder scanner in patients with POP. Patients with POP to the hymen were offered inclusion. Primary outcome was the absolute difference between bladder scanner and catheterization PVR. We also investigated the effect of prolapse stage on bladder scanner accuracy. A prevoid bladder volume was obtained by bladder scan. Subjects voided volume was then collected. A PVR was obtained by bladder scan, followed by a PVR by catheterization. Descriptive statistics, Wilcoxon signed-rank test, linear regression analysis, and sensitivity/specificity analysis were performed. RESULTS: We enrolled 87 subjects. There was a statistically significant difference between catheter and bladder scan PVR, with an absolute median difference of 20 mL (SD = 37.7), P < 0.001. Linear regression analysis showed a difference between mild and advanced prolapse groups. The regression coefficients of the mild prolapse group and advanced prolapse were 0.91 (confidence interval = 0.75-1.06) and 0.66 (confidence interval = 0.54-0. 78), P = 0.015, respectively, indicating a deterioration of accuracy of the bladder scanner for advanced prolapse. The sensitivity of the bladder scanner identifying catheterized PVR volumes less than 100 mL was 93.7%. For catheter PVRs greater than 100 mL, the specificity of the bladder scanner was 72.7%. CONCLUSIONS: Bladder scanner PVRs are less accurate in advanced prolapse, and PVRs of greater than 100 mL should be confirmed by catheterization.

Diseño y validación de una escala de actitudes hacia personas con orientación homosexual, estudio con estudiantes universitarios / Design and validation of a scale of attitudes towards people with homosexual orientation, study with university students

Diseñar y validar una prueba psicométrica para la medición de actitudes de jóvenes universitarios colombianos hacia las personas con orientación homosexual. MÉTODO: Se llevó a cabo una revisión teórica para conformar los componentes de la escala, se elaboró la tabla de especificaciones y luego la construcción de los reactivos. Posteriormente. se realizó un proceso de validación de contenido por jueces expertos, se hicieron los ajustes correspondientes y se realizó la aplicación inicial con 179 participantes, obteniendo los análisis factoriales exploratorios y los análisis de confiabilidad, y luego la segunda aplicación a 200 estudiantes para obtener el análisis factorial confirmatorio. RESULTADOS: se obtuvo una escala con 18 ítems agrupados en cuatro factores que explican el 56,2% de la varianza total acumulada, con un modelo factorial que presenta adecuados índices de bondad de ajuste, un alfa de Cronbach de ,926. DISCUSIÓN: se obtuvo una escala válida, confiable y consistente para evaluar las actitudes de estudiantes universitarios hacia personas con orientación homosexual

To design and corroborate a psychometrical test which measures the different outlooks of university students in Colombia towards people with a homosexual orientation. METHOD: A theoretical review was applied to the study to determine the main factors of the test. Also, a clear-cut chart was designed and with it a Licket reactive scale. Subsequently, the items validation process was executed by a group of expert judges and all the necessary modifications were made in order to have accurate results. The first application was performed on 179 participants; the obtained results were represented throughout a factor and reliability analysis. In order to acquire a confirmatory factorial analysis, a second application was made on a different group of 200 students. RESULTS: After the analysis, it was obtained a scale with 18 items which were distributed among four main factors. These factors expound the 56.2% of the total accumulated variance with a factorial model that shows adequated indexes of the goodness of fit, being alpha Cronbach of, 926. DISCUSSION: It was obtained a valid, reliable and consistent scale that allows the evaluation of university students towards people with a homosexual orientation.

Electrochemically Reduced Graphene Oxide-Based Screen-Printed Electrodes for Total Tetracycline Determination by Adsorptive Transfer Stripping Differential Pulse Voltammetry.

Disposable electrochemically reduced graphene oxide-based (ERGO) screen-printed electrodes (SPE) were developed for the determination of total tetracyclines as a sample screening approach. To this end, a selective adsorption-detection approach relied on adsorptive transfer stripping differential pulse voltammetry (AdTDPV) was devised, where the high adsorption capacity and the electrochemical properties of ERGO were simultaneously exploited. The approach was very simple, fast (6 min.), highly selective by combining the adsorptive and the electrochemical features of tetracyclines, and it used just 10 µL of the sample. The electrochemical sensor applicability was demonstrated in the analysis of environmental and food samples. The not-fully explored AdTDPV analytical possibilities on disposable nanostructured transducers become a new tool in food and environmental fields; drawing new horizons for "in-situ" analysis.