132 research outputs found
Cutting corners: The impact of storage and DNA extraction on quality and quantity of DNA in honeybee (Apis mellifera) spermatheca
The purpose of our study was to investigate methods of short-term storage that allow preservation, transport and retrieval of genetic information contained in honeybee queen's spermatheca. Genotyping of the honeybee colony requires well ahead planned sample collection, depending on the type of data to be acquired. Sampling and genotyping of spermatheca's content instead of individual offspring is timesaving, allowing answers to the questions related to patriline composition immediately after mating. Such procedure is also cheaper and less error prone. For preservation either Allprotect Tissue Reagent (Qiagen) or absolute ethanol were used. Conditions during transportation were simulated by keeping samples 6-8 days at room temperature. Six different storing conditions of spermathecas were tested, complemented with two DNA extraction methods. We have analysed the concentration of DNA, RNA, and proteins in DNA extracts. We also analysed how strongly the DNA is subjected to fragmentation (through amplification of genetic markers ANT2 and tRNA(leu)-COX2) and whether the quality of the extracted DNA is suitable for microsatellite (MS) analysis. Then, we tested the usage of spermatheca as a source of patriline composition in an experiment with three instrumentally inseminated virgin queens and performed MS analysis of the extracted DNA from each spermatheca, as well as queens' and drones' tissue. Our results show that median DNA concentration from spermathecas excised prior the storage, regardless of the storing condition and DNA extraction method, were generally lower than median DNA concentration obtained from spermathecas dissected from the whole queens after the storage. Despite the differences in DNA yield from the samples subjected to different storing conditions there was no significant effect of storage method or the DNA extraction method on the amplification success, although fewer samples stored in EtOH amplified successfully in comparison to ATR storing reagent. However, we recommend EtOH as a storing reagent due to its availability, low price, simplicity in usage in the field and in the laboratory, and capability of good preservation of the samples for DNA analysis during transport at room temperature
On the dynamics of a nonlinear energy harvester with multiple resonant zones
The dynamics of a nonlinear vibration energy harvester for rotating systems is investigated analytically through harmonic balance, as well as by numerical analysis. The electromagnetic harvester is attached to a spinning shaft at constant speed. Magnetic levitation is used as the system nonlinear restoring force for broadening the resonant range of the oscillator. The system is modelled as a Duffing oscillator with linear frequency variation under static, as well as harmonic excitation. Behaviour charts and backbone curves are extracted for the fundamental harmonic response and validated against frequency response curves for selected cases, using direct numerical integration. It is found that variation in stiffness, together with asymmetric forcing, gives rise to a novel structure of multiple resonant zones, incorporating mono-stable and bi-stable dynamics. Contrary to previously considered bi-stable energy harvesters, cross-well oscillations are realized through a transition from single-well potential energy to double-well with forward frequency sweep. Furthermore, in-well_oscillations present a hardening behaviour, unlike the well-known softening in-well response of bi-stable Duffing oscillators. The analysis shows that the proposed system has multiple resonant responses to a frequency sweep, influenced by consecutive interacting backbone curves similar to a multi-modal system. This combined effect of the transition to bi-stable dynamics and the hardening in-well oscillations induces resonant response of the harvester over multiple distinct frequency ranges. Thus, the system exhibits a broadened frequency response, enhancing its energy harvesting potential
The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2
Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase 1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age 6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score 652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc = 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N = 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in Asia and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701
Elucidating the Photocatalytic Behavior of TiO2-SnS2 Composites Based on Their Energy Band Structure
TiO2-SnS2 composite semiconducting photocatalysts with different building component ratios were prepared by hydrothermal synthesis (TiO2-SnS2-HT) and by immobilization of commercial TiO2 and SnS2 particles (TiO2-SnS2-COMM). The band gap values, which determine the catalysts’ photoactivity, were examined by diffuse reflectance spectroscopy and Kubelka–Munk transformations. The catalysts’ surface properties: specific surface area, charge and adsorption capacitance at the solid–solution interface were characterized using BET analysis, potentiometric titration and electrochemical impedance spectroscopy, respectively. The electronic band structure of TiO2-SnS2 photocatalyst, as the key property for the solar-driven photocatalysis, was deduced from the thermodynamic data and the semiconducting parameters (type of semiconductivity, concentration of the charge carriers, flat band potential) obtained by Mott–Schottky analysis. The photoactivity of both composites was studied in photocatalytic treatment of diclofenac (DCF) under simulated solar irradiation and was compared to the benchmark photocatalyst (TiO2 P25) activity. The influence of process parameters, such as pH, H2O2, and composite formulation on the effectiveness of DCF removal and conversion was investigated and discussed by employing response surface modeling (RSM) approach. The photocatalytic efficiency of both composite materials was discussed on the basis of the hetereojunction formation that facilitated the photoelectron transfer, promoting more efficient photocatalytic degradation of DCF
Distribution géographique des gobies (Gobiidae) en mer Adriatique, avec 13 nouveaux signalements dans sa partie méridionale
[EN] Prior to the present study, the gobiid biodiversity of the Adriatic Sea varied significantly between the northern (98% of the known Adriatic gobiid biodiversity) and central (89%) as compared to the southern Adriatic Sea (39%). Thirteen species are newly recorded for the southern Adriatic area and one for the central Adriatic. The relatively small collecting effort in this survey produced a large increase in the known gobiid biodiversity, which suggests that the low number of known Adriatic gobiid species in the southern Adriatic mirrors only sampling intensity and not the real species richness of the area. The gobiid zoogeography in the Adriatic is compared with that of the Mediterranean.[FR] Antérieurement à cette étude, la biodiversité des Gobiidés de la mer Adriatique variait significativement entre le nord (98% de la biodiversité des Gobiidés connus de l’Adriatique), le centre (89%) et le sud (39%). Treize espèces sont signalées ici comme nouvelles pour le sud et une pour le centre. Un effort de collecte relativement léger contribue ainsi à une augmentation significative de la biodiversité des Gobiidés, ce qui signifie que le petit nombre d’espèces connu à ce jour dans la partie méridionale de l’Adriatique n’est que le reflet de l’effort d’échantillonnage, et non la réalité de la diversité spécifique dans cette zone. La zoogéographie des Gobiidés en Adriatique est comparée à celle de la Méditerranée.RŠ received support from the Czech Ministry of Culture (project MK00002327201) and from the SYNTHESYS Programme (project ES-TAF-1249), financed by European Community Research Infrastructure Action under the FP7 “Capacities” Programme at the Museo Nacional de Ciencias Naturales (CSIC).Peer reviewe
Comparative analysis of UV-C/H2O2 and UV-A/TiO2 processes for the degradation of diclofenac in water
The study investigates the treatment of diclofenac (DCF), a pharmaceutical
included in the first watch list of the European Water Framework Directive
as a new potential priority substance in water. Since the conventional wastewater
treatment technologies do not efficiently remove DCF, advanced treatment technologies
capable of its complete removal or destruction of its biological activity,
need to be evaluated and eventually employed. For that purpose, typical representatives
of photooxidative and photocatalytic advanced oxidation processes were
applied. The effectiveness of UV-C/H2O2 and UV-A/TiO2 were compared regarding
DCF conversion and mineralization kinetics, water quality parameters for
assessing biodegradability and toxicity. In spite of similar biodegradability profiles,
the obtained results indicate different DCF degradation pathways, which are
reflected in different profiles of toxicity towards Vibrio fischeri. The observed DCF
conversion and mineralization kinetics revealed the benefits of UV-C/H2O2 process.
However, lower toxicity favored the application of photocatalytic over photooxidative
treatment for DCF removal
Degradation of polar and non-polar pharmaceutical pollutants in water by solar assisted photocatalysis using hydrothermal TiO2-SnS2
International audiencePhotocatalytic performance of a hydrothermally obtained TiO2-SnS2-HT composite was evaluated for the degradation of polar and non-polar pharmaceuticals in water, diclofenac (DCF) and memantine (MEM) respectively, under simulated solar irradiation. Favourable action of SnS2 for band gap narrowing and consequent higher effectiveness of TiO2-SnS2-HT in comparison to TiO2-P25 benchmark, came forth in the case of DCF, which is prone to adsorption and subsequent h+ attack under illumination. Subpar degradation of MEM was attributed to its’ non-reactive structure and the lack of surface interactions in accordance with the density functional theory calculations, which indicated lower interaction energies for SnS2 and MEM than SnS2 and DCF. In comparison, the initial removal of DCF at pH 4 was 59.8% with 50% SnS2 wt.%, whereas the removal of MEM was <5.3%. After 60 min of treatment, TiO2-SnS2 with 50% SnS2 wt.% achieved DCF conversion of 76.21%, outperforming the benchmark TiO2-P25, however in the case of MEM the conversion was miniscule. Solar/TiO2-SnS2 treatment of DCF yielded a decrease of toxicity towards Vibrio fischeri whilst biodegradability remained low. The observed decrease in effectiveness of solar/TiO2-SnS2 treatment in the presence of water matrix constituents is mainly contributed to sulfates and phosphates, acting as h+ scavengers
Elucidating the Photocatalytic Behavior of TiO2-SnS2 Composites Based on Their Energy Band Structure
TiO2-SnS2 composite semiconducting photocatalysts with different building component ratios were prepared by hydrothermal synthesis (TiO2-SnS2-HT) and by immobilization of commercial TiO2 and SnS2 particles (TiO2-SnS2-COMM). The band gap values, which determine the catalysts’ photoactivity, were examined by diffuse reflectance spectroscopy and Kubelka–Munk transformations. The catalysts’ surface properties: specific surface area, charge and adsorption capacitance at the solid–solution interface were characterized using BET analysis, potentiometric titration and electrochemical impedance spectroscopy, respectively. The electronic band structure of TiO2-SnS2 photocatalyst, as the key property for the solar-driven photocatalysis, was deduced from the thermodynamic data and the semiconducting parameters (type of semiconductivity, concentration of the charge carriers, flat band potential) obtained by Mott–Schottky analysis. The photoactivity of both composites was studied in photocatalytic treatment of diclofenac (DCF) under simulated solar irradiation and was compared to the benchmark photocatalyst (TiO2 P25) activity. The influence of process parameters, such as pH, H2O2, and composite formulation on the effectiveness of DCF removal and conversion was investigated and discussed by employing response surface modeling (RSM) approach. The photocatalytic efficiency of both composite materials was discussed on the basis of the hetereojunction formation that facilitated the photoelectron transfer, promoting more efficient photocatalytic degradation of DCF
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