Photodegradation of microcystin-LR using visible light-activated C/N-co-modified mesoporous TiO 2 photocatalyst

Microcystin-LR (MC-LR), a potent hepatotoxin produced by the cyanobacteria, is of increasing concern worldwide because of severe and persistent impacts on humans and animals by inhalation and consumption of contaminated waters and food. In this work, MC-LR was removed completely from aqueous solution using visible-light-active C/N-co-modified mesoporous anatase/brookite TiO 2 photocatalyst. The co-modified TiO 2 nanoparticles were synthesized by a one-pot hydrothermal process, and then calcined at different temperatures (300, 400, and 500 °C). All the obtained TiO 2 powders were analyzed by X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscope (TEM), specific surface area (SSA) measurements, ultraviolet-visible diffuse reflectance spectra (UV-vis DRS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, and photoluminescence (PL) analysis. It was found that all samples contained mixed-phase TiO 2 (anatase and brookite), and the content of brookite decreased with an increase in calcination temperature, as well as the specific surface area and the content of non-metal elements. The effects of initial pH value, the TiO 2 content, and MC-LR concentration on the photocatalytic activity were also studied. It was found that the photocatalytic activity of the obtained TiO 2 photocatalysts declined with increasing temperature. The complete degradation (100%) of MC-LR (10 mg L -1 ) was observed within 3 h, using as-synthesized co-modified TiO 2 (0.4 g L -1 ) at pH 4 under visible light. Based on the obtained results, the mechanism of MC-LR degradation has been proposed. © 2019 by the authors

Geographical differences in semen characteristics of 13 892 infertile men

Objective: To assess the relationship between geographical differences and all semen parameters, across 13,892 infertile men of 84 diverse nationalities, recruited at a specialised tertiary hospital that represents the main healthcare provider in Qatar. Male infertility is an important and global public health problem. Despite this, there is a significant scarcity of epidemiological male infertility and semen analysis research in the Middle East and North Africa (MENA) region, as well as geographical comparisons with other parts of the world. Patients and methods: Retrospective study of semen findings of 13 892 infertile men assessed at the Male Infertility Unit at Hamad Medical Corporation, in Qatar between January 2012 and August 2015. Based on country of origin, patients were categorised into those from the MENA region (n = 8799) and non-MENA patients (n = 5093). The two groups were compared across demographic features and semen characteristics: age, sperm volume, sperm total motility, sperm progressive motility (PMot), abnormal sperm forms (ABF), and sperm DNA fragmentation (SDF). Results: The whole sample's mean (SD) age was 35.7 (0.7) years, sperm concentration was 32.3 (0.25) × 106 sperm/mL, total motility was 45.4 (0.2)%, sperm PMot was 25.1 (0.2)%, and ABF was 79.9 (0.2)%. Overall, 841 patients had azoospermia (6.05%), 3231 had oligospermia (23.3%), 4239 had asthenospermia (30.5%) and 6772 had teratospermia (48.7%). SDF (1050 patients) was abnormal in 333 patients (31.7%). MENA patients were significantly younger than their non-MENA counterparts and had a greater semen volume. Non-MENA patients had significantly higher sperm counts, total motility and PMot, and lower ABF. SDF showed no statistical difference between the two groups. MENA patients had significantly higher prevalence of oligospermia, asthenospermia, and teratospermia; and lower prevalence of normal sperm concentration, normal motility, and normal morphology. Throughout the 4 years of the study, MENA patients constantly had significantly lower sperm counts; generally lower sperm total motility percentage and generally lower quality sperm morphology. We compared patients by age (≤40 and >40 years): in the patients aged ≤40 years, the same results as for the overall study were reproduced; in the >40-years group, the same results were reproduced with the exception of morphology, which was not significantly different between the MENA and non-MENA patients. Conclusion: Semen quality is generally lower in male infertility patients from the MENA region compared to non-MENA regions. © 2018 Arab Association of UrologyScopu

Over-expression of β-catenin is associated with high grade of prostatic cancer in Libyan patients

Objectives: At present, sufficient prognostic markers for prostate cancer (PCa) progression are still lacking, in spite of thorough investigation. The aim of this study was to evaluate abnormalities of β-catenin protein expression, subcellular localization and determine its relation to different clinicopathological features anddisease free survival in prostate cancer patients.Patients and methods: Forty prostate cancer specimens, obtained from patients with different stages of prostate cancer (83% stage IV) who underwent a radical prostatectomy or TURP flanked by 2006 and 2011, β-catenin was determined by immuno-histochemistry (IHC). The membranous expression was semi- quantitatively evaluated in four scores (0, 1+, 2+, 3+). Clinical records of these patients were studied for follow up data.Results: β-Catenin immune staining results show over-expression of β-catenin in PCa Libyan patients. There was no statistically significant difference in β-catenin immune expression as regards histopathological type, perineural invasion, tumor stage, biological recurrence. However, β-catenin over-expression showed significant correlation with old age (p < 0.014).Conclusions: We concluded that changes in expression and cell distribution of β-catenin correlated with the progression degree of prostate adenocarcinoma, signifying a role of this molecule as a marker of progression and prognosis. Further investigations, on a larger and more heterogeneous population, should be carried out to validate and extend our results.Keywords: Prostate cancer; β-Catenin expression; Immuno-histochemistry; Gleason score; Prognosi

A comparative study of microcystin-LR degradation by UV-a, solar and visible light irradiation using bare and C/N/S-modified titania

In an endeavor to tackle environmental problems, the photodegradation of microcystin- LR (MC-LR), one of the most common and toxic cyanotoxins, produced by the cyanobacteria blooms, was examined using nanostructured TiO2 photocatalysts (anatase, brookite, anatase- brookite, and C/N/S co-modified anatase-brookite) under UV-A, solar and visible light irradiation. The tailoring of TiO2 properties to hinder the electron-hole recombination and improve MC-LR adsorption on TiO2 surface was achieved by altering the preparation pH value. The highest photocatalytic efficiency was 97% and 99% with degradation rate of 0.002 mmol L-1 min-1 and 0.0007 mmol L-1 min-1 under UV and solar irradiation, respectively, using a bare TiO2 photocatalyst prepared at pH 10 with anatase to brookite ratio of ca. 1:2.5. However, the bare TiO2 samples were hardly active under visible light irradiation (<25%) due to a large band gap. Upon UV, solar and vis irradiation, the complete MC-LR degradation (100%) was obtained in the presence of C/N/S comodified TiO2 with a degradation rate constant of 0.26 min-1, 0.11 min-1 and 0.04 min-1, respectively. It was proposed that the remarkable activity of co-modified TiO2 might originate from its mixedphase composition, mesoporous structure, and non-metal co-modification

Oxidation–reduction potential and sperm DNA fragmentation, and their associations with sperm morphological anomalies amongst fertile and infertile men

Objective: To assess seminal oxidation–reduction potential (ORP) and sperm DNA fragmentation (SDF) in male infertility and their relationships with sperm morphology in fertile and infertile men. Patients and methods: Prospective case-control study comparing the findings of infertile men (n = 1168) to those of men with confirmed fertility (n = 100) regarding demographics and semen characteristics (conventional and advanced semen tests). Spearman rank correlation assessed the correlation between ORP, SDF, and different morphological indices. Means of ORP and SDF were assessed in variable levels of normal sperm morphology amongst all participants. Results: Infertile patients had a significantly lower mean sperm count (32.7 vs 58.7 × 10 6 sperm/mL), total motility (50.1% vs 60.4%), and normal morphology (5.7% vs 9.9%). Conversely, infertile patients had significantly higher mean head defects (54% vs 48%), and higher ORP and SDF values than fertile controls. ORP and SDF showed significant positive correlations and significant negative correlations with sperm head defects and normal morphology in infertile patients, respectively. ORP and SDF were significantly inversely associated with the level of normal sperm morphology. Using receiver operating characteristic curve analysis, ORP and SDF threshold values of 1.73 mV/10 6 sperm/mL and 25.5%, respectively, were associated with 76% and 56% sensitivity and 72% and 72.2% specificity, respectively, in differentiating <4% from ≥4% normal morphology. Conclusion: A direct inverse relationship exists between seminal ORP and SDF with various levels of normal sperm morphology. Using ORP and SDF measures in conjunction with standard semen morphology analysis could validate the result of the fertility status of patients. © 2017 Arab Association of UrologyScopu

Cubically cage-shaped mesoporous ordered silica for simultaneous visual detection and removal of uranium ions from contaminated seawater

A dual-function organic-inorganic mesoporous structure is reported for naked-eye detection and removal of uranyl ions from an aqueous environment. The mesoporous sensor/adsorbent is fabricated via direct template synthesis of highly ordered silica monolith (HOM) starting from a quaternary microemulsion liquid crystalline phase. The produced HOM is subjected to further modifications through growing an organic probe, omega chrome black blue G (OCBBG), in the cavities and on the outer surface of the silica structure. The spectral response for [HOM-OCBBG → U(VI)] complex shows a maximum reflectance at λmax = 548 nm within 1 min response time (tR); the LOD is close to 9.1 μg/L while the LOQ approaches 30.4 μg/L, and this corresponds to the range of concentration where the signal is linear against U(VI) concentration (i.e., 5-1000 μg/L) at pH 3.4 with standard deviation (SD) of 0.079 (RSD% = 11.7 at n = 10). Experiments and DFT calculations indicate the existence of strong binding energy between the organic probe and uranyl ions forming a complex with blue color that can be detected by naked eyes even at low uranium concentrations. With regard to the radioactive remediation, the new mesoporous sensor/captor is able to reach a maximum capacity of 95 mg/g within a few minutes of the sorption process. The synthesized material can be regenerated using simple leaching and re-used several times without a significant decrease in capacity. Graphical abstract: [Figure not available: see fulltext.

Mutation analysis of BRCA1 and BRCA2 genes in Iranian high risk breast cancer families

Background: Telomerase is a ribonucleoprotein enzyme that synthesises telomeres after cell division and maintains chromosomal stability leading to cellular immortalization. Telomerase has been associated with negative prognostic indicators in some studies. The present study aims to detect any association between telomerase sub-units: hTERT and hTR and the prognostic indicators including tumour's size and grade, nodal status and patient's age. Methods: Tumour samples from 46 patients with primary invasive breast cancer and 3 patients with benign tumours were collected. RT-PCR analysis was used for the detection of hTR, hTERT, and PGM1 (as a housekeeping) genes expression. Results: The expression of hTR and hTERT was found in 31(67.4%) and 38 (82.6%) samples respectively. We observed a significant association between hTR gene expression and younger age at diagnosis (p = 0.019) when comparing patients ≤ 40 years with those who are older than 40 years. None of the benign tumours expressed hTR gene. However, the expression of hTERT gene was revealed in 2 samples. No significant association between hTR and hTERT expression and tumour's grade, stage and nodal status was seen. Conclusion: The expression of hTR and hTERT seems to be independent of tumour's stage. hTR expression probably plays a greater role in mammary tumourogenesis in younger women (≤ 40 years) and this may have therapeutic implications in the context of hTR targeting strategies

Cobalt doped titania-carbon nanosheets with induced oxygen vacancies for photocatalytic degradation of uranium complexes in radioactive wastes

The photocatalytic degradation of uranium complexes is considered among the most efficient techniques for the efficient removal of uranium ions/complexes from radioactive wastewater. Described here is a nanostructured photocatalyst based on a cobalt-doped TiO2 composite with induced oxygen vacancies (Co@TiO2-C) for the photocatalytic removal of uranium complexes from contaminated water. The synergy between oxygen vacancies and Co-doping produced a material with a 1.7 eV bandgap, while the carbon network facilitates electron movement and hinders the e-h recombination. As a result, the new photocatalyst enables the decomposition of uranium-arsenazo iii complexes (U-ARZ3), followed by photocatalytic reduction of hexavalent uranium to insoluble tetravalent uranium. Combined with the nanosheet structure's high surface area, the photocatalytic decomposition, reduction efficiency, and kinetics were significantly enhanced, achieving almost complete U(vi) removal in less than 20 minutes from solution with a concentration as high as 1000 mL g−1. Moreover, the designed photocatalyst exhibits excellent stability and reusability without decreasing the photocatalytic performance after 5 cycles

Atrial-like cardiomyocytes from human pluripotent stem cells are a robust preclinical model for assessing atrial-selective pharmacology

Drugs targeting atrial-specific ion channels, K(v)1.5 or K(ir)3.1/3.4, are being developed as new therapeutic strategies for atrial fibrillation. However, current preclinical studies carried out in non-cardiac cell lines or animal models may not accurately represent the physiology of a human cardiomyocyte (CM). In the current study, we tested whether human embryonic stem cell (hESC)-derived atrial CMs could predict atrial selectivity of pharmacological compounds. By modulating retinoic acid signaling during hESC differentiation, we generated atrial-like (hESC-atrial) and ventricular-like (hESC-ventricular) CMs. We found the expression of atrial-specific ion channel genes, KCNA5 (encoding Kv1.5) and KCNJ3 (encoding K-ir 3.1), in hESC-atrial CMs and further demonstrated that these ion channel genes are regulated by COUP-TF transcription factors. Moreover, in response to multiple ion channel blocker, vernakalant, and K(v)1.5 blocker, XEN-D0101, hESC-atrial but not hESC-ventricular CMs showed action potential (AP) prolongation due to a reduction in early repolarization. In hESC-atrial CMs, XEN-R0703, a novel K(ir)3.1/3.4 blocker restored the AP shortening caused by CCh. Neither CCh nor XEN-R0703 had an effect on hESC-ventricular CMs. In summary, we demonstrate that hESC-atrial CMs are a robust model for pre-clinical testing to assess atrial selectivity of novel antiarrhythmic drugs