Is photoelectrocatalysis an efficient process to degrade endocrine disruptors chemicals?

Endocrine disruptors chemicals (EDCs) pose significant health risks, including cancer, behavioral disorders, and infertility. In this study, we employed the photoelectrocatalysis (PEC) technique with optimized tungsten oxide (WO3) nanostructures as a photoanode to degrade three diverse EDCs: methiocarb, dimethyl phthalate, and 4-tert-butylphenol. PEC degradation tests were carried out for individual contaminants and a mixture of them, assessing efficiency across different EDC families. Ultra High-Performance Liquid Chromatography and Mass Spectrometry was used to control the course of the experiments. For individual solutions, 4-tert-butylphenol and methiocarb were 100% degraded at 1 hour of PEC degradation. Among the tested EDCs, dimethyl phthalate showed the highest resistance to degradation when treated individually. However, when assessed in a mixture with the other EDCs, the degradation efficiency of dimethyl phthalate increased compared to its individual treatment. Furthermore, four degradation intermediates were identified for each contaminant. Finally, toxicity tests revealed that the initial solution was more toxic than the samples treated for all the contaminants tested, except for the phthalate.

Degradation of Methylparaben Using Optimal WO3 Nanostructures: Influence of the Annealing Conditions and Complexing Agent.

In this work, WO3 nanostructures were synthesized with different complexing agents (0.05 M H2O2 and 0.1 M citric acid) and annealing conditions (400 °C, 500 °C and 600 °C) to obtain optimal WO3 nanostructures to use them as a photoanode in the photoelectrochemical (PEC) degradation of an endocrine disruptor chemical. These nanostructures were studied morphologically by a field emission scanning electron microscope. X-ray photoelectron spectroscopy was performed to provide information of the electronic states of the nanostructures. The crystallinity of the samples was observed by a confocal Raman laser microscope and X-ray diffraction. Furthermore, photoelectrochemical measurements (photostability, photoelectrochemical impedance spectroscopy, Mott-Schottky and water-splitting test) were also performed using a solar simulator with AM 1.5 conditions at 100 mW·cm-2. Once the optimal nanostructure was obtained (citric acid 0.01 M at an annealing temperature of 600 °C), the PEC degradation of methylparaben (CO 10 ppm) was carried out. It was followed by ultra-high-performance liquid chromatography and mass spectrometry, which allowed to obtain the concentration of the contaminant during degradation and the identification of degradation intermediates. The optimized nanostructure was proved to be an efficient photocatalyst since the degradation of methylparaben was performed in less than 4 h and the kinetic coefficient of degradation was 0.02 min-1.

Photodegradation of 2,4-D (dichlorophenoxyacetic acid) with Rh/TiO2; comparative study with other noble metals (Ru, Pt, and Au).

In this work the effect of noble metal on the photodegradation of 2,4-dichlorophenoxyacetic acid herbicide using TiO2 as support was studied. The metals and concentration were: Rh, Ru, Pt and Au and 1, 0.98, 1.89, and 1.91 wt% respectively. Rhodium was taken as reference for this experiment. The samples were characterized by X-Ray Diffraction (XRD), UV-vis absorption spectra, N2 physisorption (BET Specific Surface Area), High Annular Angle Analysis Darkfield (HAADF) and Transmission Electron Microscopy Scanning (STEM), H2 chemisorption, optical emission spectroscopy with inductive coupling plasma analysis (ICP-OES), solid fluorescence, X-ray Photoelectron Spectroscopy (XPS) and OH quantification. The presence of the anatase crystalline phase was mostly confirmed in all samples. The band gap decreased with the presence of metal (from 3.24 to 2.92 eV). The specific area was a function of the metal particle size. The metal particle diameter showed the following sequence Pt > Ru > Au > Rh. By XPS, TiO2 does not manifest changes in oxidation states, but when impregnated with metals, only Pt shows the highest abundance of any oxidized state (Pt2+). The presence of metal reveals less electron-hole recombination compared with titanium oxide. The results of photocatalytic activity showed that Pt and Rh are the two metals with the highest mineralization (99.0 and 98.3%, respectively).

Does ipsilateral corticospinal excitability play a decisive role in the cross-education effect caused by unilateral resistance training? A systematic review. / ¿Desempeña un papel decisivo la excitabilidad corticoespinal ipsilateral en el efecto cruzado provocado por el entrenamiento de fuerza unilateral? Una revisión sistemática.

INTRODUCTION: Unilateral resistance training has been shown to improve muscle strength in both the trained and the untrained limb. One of the most widely accepted theories is that this improved performance is due to nervous system adaptations, specifically in the primary motor cortex. According to this hypothesis, increased corticospinal excitability (CSE), measured with transcranial magnetic stimulation, is one of the main adaptations observed following prolonged periods of training. The principal aim of this review is to determine the degree of adaptation of CSE and its possible functional association with increased strength in the untrained limb. DEVELOPMENT: We performed a systematic literature review of studies published between January 1970 and December 2016, extracted from Medline (via PubMed), Ovid, Web of Science, and Science Direct online databases. The search terms were as follows: (transcranial magnetic stimulation OR excitability) AND (strength training OR resistance training OR force) AND (cross transfer OR contralateral limb OR cross education). A total of 10 articles were found. CONCLUSION: Results regarding increased CSE were inconsistent. Although the possibility that the methodology had a role in this inconsistency cannot be ruled out, the results appear to suggest that there may not be a functional association between increases in muscle strength and in CSE.

Photoelectrocatalyzed degradation of organophosphorus pesticide fenamiphos using WO3 nanorods as photoanode.

In this study, WO3 nanostructures were synthesized by the electrochemical anodization technique to use them on the degradation of persistent organic compounds such as the pesticide fenamiphos. The acids electrolyte used during the anodization were two different: 1.5 M H2SO4 - 0.05 M H2O2 and 1.5 M CH4O3S - 0.05 M H2O2. Once the samples have been manufactured, they have been subjected to different tests to analyze the properties of the nanostructures. With Field Emission Scanning Electron Microscopy (FE-SEM) the samples have been examined morphologically, their composition and crystallinity has been studied through Raman Spectroscopy and their photoelectrochemical behaviour by Photoelectrochemical Impedance Spectroscopy (PEIS). Finally, degradation tests have been carried out using the technique known as photoelectrocatalysis (PEC). The conditions that were applied in this technique were a potential of 1 VAg/AgCl and simulated solar illumination. The degradation process was monitored by UV-Visible and High-Performance liquid Chromatography (HPLC) to control the course of the experiment. The nanostructures obtained with 1.5 M CH4O3S - 0.05 M H2O2 electrolyte showed a better photoelectrochemical behaviour than nanostructures synthesized with 1.5 M H2SO4 - 0.05 M H2O2. The fenamiphos degradation was achieved at 2 h of experiment and the intermediate formation was noticed at 1 h of PEC experiment.

Effects of acute and chronic unilateral resistance training variables on ipsilateral motor cortical excitability and cross-education: A systematic review.

OBJECTIVE: The increase in voluntary force of an untrained limb (i.e. Cross-education) after unilateral resistance training (RT) is believed to be a consequence of cortical adaptations. However, studies measuring neurophysiological adaptations with transcranial magnetic stimulation (TMS) found inconsistent results. One unexamined factor contributing to the conflicting data is the variation in the type and intensity of muscle contractions, fatigue, and the strategies of pacing the movement. Therefore, the purpose was to analyse how those unilateral RT variables affect the adaptations in ipsilateral M1 (iM1) and cross-education. METHODS: We performed a systematic literature review, with the following search terms with Boolean conjunctions: "Transcranial magnetic stimulation" AND "Ipsilateral cortex" AND "Resistance training". RESULTS: The 11 acute and 12 chronic studies included partially support the idea of increased cortical excitability and reduced intracortical inhibition in iM1, but the inconsistency between studies was high. CONCLUSIONS: Differences in type and intensity of contraction, fatigue, and strategies of pacing the movement contributed to the inconsistencies. The tentative conclusion is that high intensity eccentric or externally paced contractions are effective to increase iM1 excitability but cross-education can occur in the absence of such changes. Thus, the mechanism of the cross-education examined with TMS remains unclear.

Talus fractures. Functional results for polytraumatized patients. / Fracturas de astrágalo. Resultados funcionales en pacientes politraumatizados.

Talar fractures are uncommon lesions (0.1-0.9%) and have a high rate of complications. One of the situations in which a fracture of the talus can occur is in the context of polytrauma which may further compromise the functional prognosis. The aim of this study was to analyze the functional results in patients with talar fractures whether or not they occurred in the context of polytrauma. Observational study on a retrospective cohort of 24 patients operated in our centre (2008-2016). They were grouped according to whether they were polytraumatized (ISS>16) or not (ISS≤16). Review of sociodemographic, radiographic, functional variables (VAS pain scale and FADI -Foot and Ankle Disability Index-) and the onset of complications such as arthrosis, arthrodesis or avascular necrosis. Review of 25 talar fractures in 24 patients with a mean age of 38 years (19-75) and a mean follow-up of 4.2 years (0.5-9). According to the ISS, 44% of patients (11) were polytraumatized and 56% (14) were not. The average score according to the FADI scale was 62 points for the polytraumatized patients and 76.9 for the non-polytraumatized patients. The pain according to the VAS scale was 5.8 points in the group of polytraumatized patients and 4.3 in the non-polytraumatized patient group. Regarding complications, 64% of the polytraumatized patients and 43% of the non-traumatized patients had a complication. 36% of the polytraumatized patients had clinical and radiological signs of subtalar arthrosis compared to 35% of the non-traumatized patients, of whom 27% underwent arthrodesis compared to 28% of the non-traumatized patients. 27% of the polytraumatized patients were diagnosed with avascular necrosis as opposed to 0% of the non-polytraumatized patients.

Photoelectrocatalyzed degradation of a pesticides mixture solution (chlorfenvinphos and bromacil) by WO3 nanosheets.

A photoelectrocatalyst consisting of WO3 nanosheets or nanorods has been synthesized by electrochemical anodization under hydrodynamic conditions, and has been used for the degradation of two toxic pesticides: chlorfenvinphos and bromacil. Nanostructures have been characterized by FESEM and Raman spectroscopy. Photoelectrochemical degradation tests have been carried out both for individual pesticide solutions and for a mixture solution, and the concentration evolution with time has been followed by UV-Vis spectrophotometry. For individual pesticides, pseudo-first order kinetic coefficients of 0.402h-1 and 0.324h-1 have been obtained for chlorfenvinphos and bromacil, respectively, while for the mixture solution, these kinetic coefficients have been 0.162h-1 and 0.408h-1. The change in behavior towards pesticide degradation depending on whether individual or mixture solutions were used might be indicative of a competitive process between the two pesticide molecules when interacting with the WO3 nanostructures surface or when approaching the semiconductor/electrolyte interface.

Zika y casos de microcefalia en el estado Zulia: aspectos clínicos y epidemiológicos del brote, año 2016 / Zika and cases of microcephaly in the state of Zulia: clinical and epidemiological aspects of the sprout, year 2016

El Zika es una enfermedad emergente en Venezuela y en el estado Zulia, evoluciona generalmente de manera benigna y puede producir complicaciones como síndrome Guillain Barré y microcefalia en recién nacidos. Se plantea describir los aspectos clínicos, epidemiológicos del brote de Zika y los casos de microcefalia. La investigación es descriptiva, transversal, realizada de mayo 2016 a marzo 2017. La población fue de 1.155 casos sospechosos, la muestra 228 pacientes, resultando 108 positivos por PCR en tiempo real. El mayor número de casos se presentó en la edad de 17 a 33 años (59,3%), predomina el sexo femenino (81,5%), en los municipios Maracaibo y San Francisco (75%). En relación a la sintomatología, la frecuencia fue erupción (84,3%), cefalea y fiebre (76,9%), menos común la artralgia (65,7%) y mialgias (47,2%). Durante el brote, se presentaron dos muertes del sexo masculino, representando el 1,9%; 146 casos con el síndrome de Guillain Barré y 7 casos con microcefalia correspondiente al sexo masculino (85%), con una edad gestacional del recién nacido de 37,4 semanas y sobrevida de 85%. La principal recomendación, debe estar orientada al control del vector transmisor de la enfermedad y hacer el diagnóstico de los casos sospechosos para su confirmación.

Zika is an emerging disease in Venezuela and in the state of Zulia, it generally evolves in a benign manner and can produce complications such as Guillain-Barré syndrome and microcephaly in newborns. Itis proposed to describe the clinical and epidemiological aspects of the Zika outbreak and the cases of microcephaly. The research is descriptive, cross-sectional, conducted from May 2016 to March 2017. The population consisted of 1,155 suspected cases, with a sample of 228 patients, resulting in 108 positive PCR in real time. The largest number of cases occurred at the age of 17 to 33 years (59.3%), with a predominance of females (81.5%), in the municipalities of Maracaibo and San Francisco (75%). In relation to the symptomatology, the frequent are rash (84.3%), headache and fever (76.9%), while arthralgia (65.7%) and myalgia (47.2%) are less common. During the outbreak, there were two deaths of the male sex, representing 1.9%; 146 cases with Guillain-Barré syndrome and 7 cases with microcephaly, corresponding to the male sex (85%), with a newborn gestational age of 37.4 weeks and 85% survival. The main recommendation should be directed to the control of the transmitting vector of the disease and to make the diagnosis of the suspicious cases for their confirmation.

Comparison of plasma ctDNA and tissue/cytology-based techniques for the detection of EGFR mutation status in advanced NSCLC: Spanish data subset from ASSESS.

PURPOSE: The analysis of epidermal growth factor receptor (EGFR) mutations in many patients with advanced non-small-cell lung cancer (aNSCLC) has provided the opportunity for successful treatment with specific, targeted EGFR tyrosine kinase inhibitors. However, this therapeutic decision may be challenging when insufficient tumor tissue is available for EGFR mutation testing. Therefore, blood surrogate samples for EGFR mutation analysis have been suggested. METHODS: Data were collected from the Spanish cohort of patients in the large, non-interventional, diagnostic ASSESS study (NCT01785888) evaluating the utility of circulating free tumor-derived DNA from plasma for EGFR mutation testing. The incidence of EGFR mutation in Spain and the level of concordance between matched tissue/cytology and plasma samples were evaluated. RESULTS: In a cohort of 154 eligible patients, EGFR mutations were identified in 15.1 and 11.0% of tumor and plasma samples, respectively. The most commonly used EGFR mutation testing method for the tumor tissue samples was the QIAGEN Therascreen® EGFR RGQ PCR kit (52.1%). Fragment Length Analysis + PNA LNA Clamp was used for the plasma samples. The concordance rate for EGFR mutation status between the tissue/cytology and plasma samples was 88.8%; the sensitivity was 45.5%, and the specificity was 96.7%. CONCLUSIONS: The high concordance between the different DNA sources for EGFR mutation testing supports the use of plasma samples when tumor tissue is unavailable.

Neural adaptations after short-term wingate-based high-intensity interval training.

OBJECTIVES: This study examined the neural adaptations associated with a low-volume Wingate-based High Intensity Interval Training (HIIT). METHODS: Fourteen recreationally trained males were divided into an experimental (HIIT) and a control group to determine whether a short-term (4 weeks) Wingate-based HIIT program could alter the Hoffmann (H-) reflex, volitional (V-) wave and maximum voluntary contraction (MVC) of the plantar-flexor muscles, and the peak power achieved during a Wingate test. RESULTS: Absolute and relative peak power increased in the HIIT group (ABS_Ppeak: +14.7%, P=0.001; and REL_Ppeak: +15.0%, P=0.001), but not in the control group (ABS_Ppeak: P=0.466; and REL_Ppeak: P=0.493). However, no significant changes were found in the MVC (P>0.05 for both groups). There was a significant increase in H-reflex size after HIIT (+24.5%, P=0.004), while it remained unchanged in the control group (P=0.134). No significant changes were observed either in the V-wave or in the Vwave/Mwave ratio (P>0.05 for both groups). CONCLUSION: The Wingate-based training led to an increased peak power together with a higher spinal excitability. However, no changes were found either in the volitional wave or in the MVC, indicating a lack of adaptation in the central motor drive.

Gas exchanges and water use efficiency in the selection of tomato genotypes tolerant to water stress.

Water stress can affect the yield in tomato crops and, despite this, there are few types of research aiming to select tomato genotypes resistant to the water stress using physiological parameters. This experiment aimed to study the variables that are related to the gas exchanges and the efficiency in water use, in the selection of tomato genotypes tolerant to water stress. It was done in a greenhouse, measuring 7 x 21 m, in a randomized complete block design, with four replications (blocks), being five genotypes in the F2BC1 generation, which were previously obtained from an interspecific cross between Solanum pennellii versus S. lycopersicum and three check treatments, two susceptible [UFU-22 (pre-commercial line) and cultivar Santa Clara] and one resistant (S. pennellii). At the beginning of flowering, the plants were submitted to a water stress condition, through irrigation suspension. After that CO2 assimilation, internal CO2, stomatal conductance, transpiration, leaf temperature, instantaneous water use efficiency, intrinsic efficiency of water use, instantaneous carboxylation efficiency, chlorophyll a and b, and the potential leaf water (Ψf) were observed. Almost all variables that were analyzed, except CO2 assimilation and instantaneous carboxylation efficiency, demonstrated the superiority of the wild accession, S. pennellii, concerning the susceptible check treatments. The high photosynthetic rate and the low stomatal conductance and transpiration, presented by the UFU22/F2BC1#2 population, allowed a better water use efficiency. Because of that, these physiological characteristics are promising in the selection of tomato genotypes tolerant to water stress.

Characterization of Fluorotic Enamel After Microabrasion and Desensitizing Agent

ntroduction. Enamel microabrasion is a procedure used for removing a superficial layer of enamel that has some alteration of color and/or texture caused by dental fluorosis. The purpose of this study was to compare the microhardness and micromorphology of the fluorotic enamel surface after microabrasion with 6.6% hydrochloric acid and silica or 18% hydrochloric acid and evaluate the effect of desensitizing agent exposure on the treated enamel. Materials and Methods. Twenty anterior teeth with moderate fluorosis were divided into two groups: 1) Perla-Dent® group and 2) Opalustre® group. Each buccal surface of incisors was sectioned to obtain samples 3x3 mm. The samples were then mounted in acrylic blocks. The enamel surface of the blocks was polished, after the microabrasion materials and desensitizing agent were applied according to the manufacturer's instructions. All samples were analyzed by Vickers microhardness tester and scanning electron microscopy (SEM). Results. Both experimental groups presented a decrease in the microhardness values, with statistically significant differences (p<0.0001) when comparing the baseline and after treatments values. To compare the microhardness values after both microabrasion and desensitizing treatment in the study groups, it was observed that the Perla-Dent® group obtained lower values than the Opalescence® group with a statistically significant difference (p<0.0001). The representative images of study groups in SEM showed the enamel surface morphology after Perla-Dent® treatment more irregular and a very marked relief than that observed in enamel surface morphology after Opalustre® treatment. Conclusion. The surface of the enamel was more affected with Perla-Dent® treatment than with Opalustre® treatment and the placement of UltraEz® agent does not recover its baseline microhardness.

ntroducción. La microabrasión del esmalte es un procedimiento usado para remover la capa superficial de esmalte que tiene alguna alteración de color y / o textura causada por la fluorosis dental. El objetivo de este estudio fue comparar la microdureza y micromorfología de la superficie del esmalte fluorado después de microabrasión con ácido clorhídrico al 6,6% y sílice ó 18% de ácido clorhídrico y evaluar el efecto de la exposición del agente desensibilizante sobre el esmalte tratado. Materiales y métodos. 20 dientes anteriores con fluorosis moderada se dividieron en dos grupos: 1) grupo PerlaDent® y 2) grupo Opalustre®. La superficie bucal se seccionó para obtener muestras de 3x3 mm. Las muestras se montaron luego en bloques acrílicos. La superficie del esmalte de los bloques fue pulida, y posteriormente los materiales de microabrasión y el agente desensibilizante se aplicaron de acuerdo con las instrucciones del fabricante. Todas las muestras fueron analizadas por medio de microdureza Vickers y Microscopía electrónica de barrido (MEB). Resultados. Ambos grupos experimentales presentaron disminución de los valores de microdureza con diferencias estadísticamente significativas (p<0.0001) al comparar los valores de antes y después de los tratamientos. Al comparar los valores de microdureza después del tratamiento de microabrasión y desensibilizante en los grupos de estudio, se observó que el grupo Perla-Dent® obtuvo valores más bajos que el grupo Opalustre® con diferencia estadísticamente significativa (p<0.0001). Las imágenes representativas de los grupos de estudio en MEB mostraron la morfología de la superficie del esmalte después del tratamiento con Perla-Dent® más irregular y con un relieve más marcado que el observado en la superficie del esmalte después del tratamiento con Opalustre®. Conclusión. La superficie del esmalte se presentó más afectada posterior al tratamiento con Perla-Dent® que con Opalustre® y la colocación del agente UltraEz® no logró recuperar el grado de microdureza basal.

Mini tomato genotypes resistant to the silverleaf whitefly and to two-spotted spider mites.

The mini tomato production has expanded, becoming an amazing alternative for enterprise. Despite all commercial potential, the cultivation has the occurrence of pests as main obstacle during the crop development. Nowadays, there are no researches that aimed obtaining genotypes with high acylsugar content, capable of providing a broad-spectrum resistance to pests. This study aimed the selection of mini tomato genotypes, with high acylsugar content, and checking the resistance level to the silverleaf whitefly [Bemisia tabaci (Gennadius)] and to the two-spotted spider mites (Tetranychus urticae Koch). Sixteen genotypes were evaluated, from which 12 were on the generation F2BC1, originated from the interespecific cross between Solanum pennellii versus Solanum lycopersicum L. and 4 were check treatments, being three of cultivated tomatos (cv. Santa Clara, UFU-02, and UFU-73) and the wild accession LA-716 (S. pennellii). The variables analyzed were acylsugar content, repellency to the silverleaf whitefly, repellence to the two-spotted spider mites, and density of glandular trichomes. The genotypes UFU-22-F2BC1#9 and UFU-73-F2BC1#11 have high acylsugar content and both are resistant to the pests that were evaluated. New studies must be conducted seeking for inbred lines, obtained from the selected genotypes, aiming to get commercial hybrids with high acylsugar content.

Sex differences in kinetic and neuromuscular control during jumping and landing.

In the present study, we analysed the kinetic profile together with the lower limb EMG activation pattern during a countermovement jump and its respective landing phase in males and females. Twenty subjects (10 males and 10 females) took part in the study. One experimental session was conducted in order to record kinetic and electromyographic (EMG) parameters during a countermovement jump (CMJ) and the subsequent landing phase. During the CMJ, males recorded a higher (p<0.001) performance than females in terms of jump height and power production. Stiffness values were lower in males than females due to greater centre of mass displacement during the countermovement (p<0.01). According to the EMG activity, males demonstrated greater (p<0.05) activation during the concentric phase of the jump. However, females revealed a higher co-contraction ratio in the plantar flexors during the push-off phase. During landings males showed higher (p<0.01) peak ground reaction forces (Fpeak), greater (p<0.05) stiffness and a higher maximal displacement of the CoM (p<0.05) than females. EMG analysis revealed greater EMG activity in the tibialis anterior (p<0.05) and rectus femoris (p=0.05) muscles in males. Higher plantar flexor co-activation during landing has also been found in males. Our findings demonstrated different neuromuscular control in males and females during jumping and landing.

Characterization of bacterial diversity associated with calcareous deposits and drip-waters, and isolation of calcifying bacteria from two Colombian mines.

Bacterial carbonate precipitation has implications in geological processes and important biotechnological applications. Bacteria capable of precipitating carbonates have been isolated from different calcium carbonate deposits (speleothems) in caves, soil, freshwater and seawater around the world. However, the diversity of bacteria from calcareous deposits in Colombia, and their ability to precipitate carbonates, remains unknown. In this study, conventional microbiological methods and molecular tools, such as temporal temperature gradient electrophoresis (TTGE), were used to assess the composition of bacterial communities associated with carbonate deposits and drip-waters from two Colombian mines. A genetic analysis of these bacterial communities revealed a similar level of diversity, based on the number of bands detected using TTGE. The dominant phylogenetic affiliations of the bacteria, determined using 16S rRNA gene sequencing, were grouped into two phyla: Proteobacteria and Firmicutes. Within these phyla, seven genera were capable of precipitating calcium carbonates: Lysinibacillus, Bacillus, Strenotophomonas, Brevibacillus, Methylobacterium, Aeromicrobium and Acinetobacter. FTIR and SEM/EDX were used to analyze calcium carbonate crystals produced by isolated Acinetobacter gyllenbergii. The results showed that rhombohedral and angular calcite crystals with sizes of 90µm were precipitated. This research provides information regarding the presence of complex bacterial communities in secondary carbonate deposits from mines and their ability to precipitate calcium carbonate from calcareous deposits of Colombian mines.

Therapeutic benefit of melatonin in refractory central serous chorioretinopathy.

PURPOSE: To evaluate the efficacy and safety of melatonin for the treatment of chronic central serous chorioretinopathy (CSCR). METHODS: Prospective comparative case series. A total of 13 patients with chronic CSCR were treated for 1 month: 8 patients were treated orally with 3 mg melatonin t.i.d., and 5 with placebo. All patients had 20/40 or worse Early Treatment Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity (BCVA) in the affected eye or presented an incapacitating scotoma. Most of the patients had previous failed treatments for their condition. Observational procedures included ETDRS BCVA, and complete ophthalmic examination. Optical coherence tomography (OCT) was performed at day 1 and week 4. Fluorescein angiography was performed at baseline only for diagnostic purposes. Data were subjected to two-sample t-test statistical analysis. P-values of <0.05 were considered statistically significant. RESULTS: At 1-month follow-up, BCVA significantly improved in 87.5% of patients treated with melatonin (7 of 8 patients, P<0.05). All patients showed a mean significant reduction (P<0.01) of central macular thickness (CMT) when compared with the baseline, with 3 patients (37.5%) exhibiting complete resolution of subretinal fluid at 1-month follow-up. No significant side effects were observed. No changes in BCVA or CMT were noted in the control group. CONCLUSIONS: These results suggest that melatonin is safe, well tolerated, and effective in the treatment of chronic CSCR, as it significantly improved BCVA and CMT in patients with this pathology. Further evaluations with longer follow-up and a larger patient population are desirable.

Heterogeneous variances and genetics by environment interactions in genetic evaluation of crossbred lambs.

Accounting for environmental heteroscedasticity and genetics by environment interaction (G×E) in genetic evaluation is important because animals may not perform predictably across environments. The objectives of this study were to evaluate the presence and consequences of heteroscedasticity and G×E on genetic evaluation. The population considered was crossbred lambs sired by terminal sires and reared under commercial conditions in the UK. Data on 6325 lambs sired by Charollais, Suffolk and Texel rams were obtained. The experiment was conducted between 1999 and 2002 on three farms located in England, Scotland and Wales. There were 2322, 2137 and 1866 lambs in England, Scotland and Wales, respectively. A total of 89 sires were mated to 1984 ewes of two types (Welsh and Scottish Mules). Most rams were used for two breeding seasons with some rotated among farms to create genetic links. Lambs were reared on pasture and had their parentage, birth, 5 week, 10 week, and slaughter weights recorded. Lambs were slaughtered at a constant fatness, at which they were ultrasonically scanned for fat and muscle depth. Heteroscedasticity was evaluated in two ways. First, data were separated into three subsets by farm. Within-farm variance component estimates were then compared with those derived from the complete data (Model 1). Second, the combined data were fitted, but with a heterogeneous (by farm) environmental variance structure (Model 2). To investigate G×E, a model with a random farm by sire (F×S) interaction was used (Model 3). The ratio of the F×S variance to total variance was a measure of the level of G×E in the population. Heterogeneity in environmental variability across farm was identified for all traits (P<0.01). Rank correlations of sire estimated breeding value between farms differed for Model 1 for all traits. However, sires ranked similarly (rank correlation of 0.99) for weight traits with Model 2, but less so for ultrasonic measures. Including the F×S interaction (Model 3) improved model fit for all traits. However, the F×S term explained a small proportion of variation in weights (<2%) although more in ultrasonic traits (at least 10%). In conclusion, heteroscedasticity and G×E were not large for these data, and can be ignored in genetic evaluation of weight but, perhaps, not ultrasonic traits. Still, before incorporating heteroscedasticity and G×E into routine evaluations of even ultrasonic traits, their consequences on selection response in the breeding goal should be evaluated.

Effect of surface stiffness on the neural control of stretch-shortening cycle movements.

AIM: It is accepted that leg stiffness (Kleg ) increases when surface stiffness decreases, and vice versa. However, little is known how the central nervous system fulfils this task. To understand the effect of surface stiffness on the neural control of stretch-shortening cycle movements, this study aimed to compare modulation of spinal and corticospinal excitability at distinct phases after ground contact during two-legged hopping when changing from solid to elastic ground. METHODS: Motor-evoked potentials (MEPs) induced by transcranial magnetic stimulation (TMS) and H-reflexes were elicited at the time of the short (SLR)-, medium (MLR)- and long (LLR)-latency responses of the soleus muscle (SOL) during two-legged hopping on different stiffness surfaces, elastic and stiff. RESULTS: Soleus H-reflexes during two-legged hopping on the elastic surface were lower at SLR and larger at LLR than on the stiff surface (P < 0.05 for both comparisons). SOL MEP size was higher at the time of SLR during hopping on the elastic surface than on the stiff surface (P < 0.05) although the background EMG was similar. CONCLUSION: It is argued that this phase-specific adaptation in spinal reflex excitability is functionally relevant to adjust leg stiffness to optimally exploit the properties of the elastic surface. Thus, the increased corticospinal excitability on the elastic surface may reflect a more supraspinal control of the ankle muscles to compensate the decrease in reflexive stiffness at the beginning of touchdown and/or counteract the higher postural challenges associated with the elastic surface.