46 research outputs found
Effect of glycerol, n, n-dimethylformamide and n-methyl-2-pyrrolidone on rabbit sperm stored at 4 °C and 16 °C
Artificial insemination with cooled semen is the most common practice in rabbit farms and any improvement on it helps to increase the efficiency and productivity of rabbit meat farms. Therefore, the aim of this study was to assess whether different cryoprotectant agents (CPA) as glycerol, N, N-Dimethylformamide (DMF) and N-Methyl--2-Pyrrolidone (NMP) can improve cooled rabbit sperm quality stored at 4C and 16C. Sperm samples were diluted with INRA 96® (Extender A), INRA 96® with 6% glycerol (Extender B) or 6% DMF (Extender C) or 6% NMP (Extender D) respectively and stored at 4C and 16C. Samples were then analysed at 4, 24, 48 and 72 hours after refrigeration by integrated sperm analysis system (ISAS), eosin-nigrosin stain (vitality), hypo-osmotic swelling test (HOS test) and acrosome integrity test. Extender C showed higher percentage of motility, vitality and HOS test than extender B and D (p<0.05). Whereas sperm quality decreased over time (p<0.05), data showed that the addition of DMF kept the motility and sperm plasma membrane integrity after 24 hours of storage better than other diluents. These results suggest that the addition of DMF to INRA 96® exerts a protective effect on the membrane of spermatozoa improving seminal quality
Long-term preservation of freeze-dried rabbit sperm by adding rosmarinic acid and different chelating agents
Freeze-drying (FD) technique has been applied as an alternative technology to preserve gene resources to allow simple sperm preservation and shipment at 4 degrees C. Nevertheless, DNA sperm might be damaged by mechanical or oxidative stress throughout FD procedure. Therefore, suitable protection to maintain DNA integrity is required. The aim of this study was to determine the effect of rosmarinic acid (RA) as an antioxidant and two chelating agents (EGTA and EDTA) on the DNA integrity of freeze-dried rabbit sperm after storage of the samples at 4 degrees C and room temperature for 8 months. Rabbit sperm were freeze-dried in basic medium (10 mM Tris-HCl buffer and 50 mM NaCl) supplemented with 50 mM EGTA (1), 50 mM EGTA plus 105 mu M RA (2), 50 mM EDTA (3) or 50 mM EDTA plus 105 mu M RA (4). Semen samples were kept at 4 degrees C and room temperature during 8 months. After rehydration, DNA integrity was evaluated with Sperm Chromatin Dispersion test observing that DNA fragmentation was higher when semen samples were freeze-dried with EGTA (10.9%) than with EDTA (4.1%) (p < 0.01). Furthermore, RA acted better under adverse conditions and no significant differences were found in temperature storage. Summarizing, FD is a method that can allow simple gene resources preservation among 4 degrees C to 25 degrees C during 8 months and transportation without the need for liquid nitrogen or dry ice. EDTA chelating agent is the most suitable media for freeze-dried rabbit sperm and the addition of RA protects the DNA against the oxidative stress caused during FD procedure
Struvite precipitation in wastewater treatment plants anaerobic digestion supernatants using a magnesium oxide by-product
Struvite precipitation is a well-known technology to recover and upcycle phosphorus from municipal wastewater as a slow-release fertiliser. However, the economic and environmental costs of struvite precipitation are constrained by using technical-grade reagents as a magnesium source. This research evaluates the feasibility of using a low-grade magnesium oxide (LG-MgO) by-product from the calcination of magnesite as a magnesium source to precipitate struvite from anaerobic digestion supernatants in wastewater treatment plants. Three distinct LG-MgOs were used in this research to capture the inherent variability of this by-product. The MgO content of the LG-MgOs varied from 42 % to 56 %, which governed the reactivity of the by-product. Experimental results showed that dosing LG-MgO at P:Mg molar ratio close to stoichiometry (i.e. 1:1 and 1:2) favoured struvite precipitation, whereas higher molar ratios (i.e. 1:4, 1:6 and 1:8) favoured calcium phosphate precipitation due to the higher calcium concentration and pH. At a P:Mg molar ratio of 1:1 and 1:2, the percentage of phosphate precipitated was 53-72 % and 89-97 %, respectively, depending on the LG-MgO reactivity. A final experiment was performed to examine the composition and morphology of the precipitate obtained under the most favourable conditions, which showed that (i) struvite was the mineral phase with the highest peaks intensity and (ii) struvite was present in two different shapes: hopper and polyhedral. Overall, this research has demonstrated that LG-MgO is an efficient source of magnesium for struvite precipitation, which fits the circular economy principles by valorising an industrial by-product, reducing the pressure on natural resources, and developing a more sustainable technology for phosphorus recovery
Traducció i immigració : la formació de traductors i intèrprets als serveis públics, noves solucions per a noves realitats
L'estudi que presentem té com a propòsit difondre els objectius, la metodologia i els principals resultats del projecte Traducció i immigració: la formació de traductors i intèrprets als serveis públics, noves solucions per a noves realitats, dut a terme pel grup MIRAS (Mediació i Interpretació: Recerca en l'Àmbit Social) entre els anys 2009 i 2010. L'objectiu general d'aquest projecte ha estat recopilar i analitzar un corpus significatiu de dades empíriques sobre la situació de la traducció i interpretació als serveis públics a Catalunya des de la perspectiva dels tres agents que participen en la interacció comunicativa: a) els mediadors-traductors-intèrprets, b) els usuaris dels serveis públics, i c) els proveïdors directes d'aquests serveis. Les dades obtingudes -tant quantitatives com qualitatives- ens han permès no tan sols definir el perfil i la pràctica professional del traductor i intèrpret als serveis públics de Catalunya, sinó també obtenir una gran quantitat d'informació objectiva sobre les necessitats i les preferències dels usuaris i proveïdors dels serveis públics: amb quin tipus de dificultats comunicatives se solen enfrontar, quin tipus de mediació prefereixen uns i altres, quines són les llengües estrangeres més requerides, quines particularitats presenta cada àmbit d'actuació, etc.The aim of the present study is to publish the principal objectives, methodology and results of the project Translation and Immigration: the training of public service translators and interpreters, new solutions for new scenarios. The overall objective of the project, which was carried out during the period 2009 -2010, was to assemble and analyze a significant corpus of empirical data on the situation of Public Service Interpreting and Translating in Catalonia from the perspective of the three agents participating in the communicative interaction: a) the mediator-translator-interpreter, b) the public services end-user and c) the front-line public services provider. From the data obtained -both quantitative and qualitative- we were able not only to define the professional profile and practice of the public services translator and interpreter in Catalonia, but also to obtain a large quantity of objective information about the needs and preferences of the endusers and providers of public services: what sort of difficulties do they encounter in their communication exchanges; what sort of mediation do the two groups prefer; which foreign languages are most in demand; what are the specific characteristics involved in each field of intervention, etc
Effects of seminal plasma and different cryoprotectants on rabbit sperm preservation at 16°c
The purpose of this research was to assess whether the presence of seminal plasma (SP) can improve sperm quality of rabbit spermatozoa stored at 16°C for 72 h and moreover evaluate the cryoprotectant effects of glycerol, N-N-Dimethylformamide (DMF), and N-methyl-2-pyrrolidone (NMP). Semen samples were pooled and divided in eight fractions. Four of them were diluted with INRA (extender A), INRA with 6% glycerol (extender B), INRA with 6% DMF (extender C), or INRA with 6% NMP (extender D), respectively. The other four fractions were centrifuged, and the supernatant was removed in order to eliminate SP. Each sample was then resuspended with extender A, B, C, or D, respectively. All samples were stored at 16°C and analysed at 4, 24, 48, and 72 h by ISAS®, vitality test, HOS test, and acrosome integrity test. After analyse of the results, SP samples showed a significantly higher percentage (P=0.020) in the HOS test (71.9 ± 1.6%) than non-SP samples (66.5 ± 1.6%). Non-SP samples had better results for kinematic parameters. Extenders A and C showed great results for the percentage of motile spermatozoa (63.1 ± 4.3% and 63.4 ± 3.7%, respectively), vitality (88.9 ± 2.6% and 87.7 ± 2.7%, respectively), and HOS test (68.9 ± 1.4% and 75.2 ± 1.4%, respectively). Extenders B and D showed worse data for sperm quality. These results suggest that SP has a protective effect on rabbit sperm membranes and maintains better sperm motility. The addition of glycerol and NMP to INRA does not improve rabbit sperm quality; nevertheless, the DMF cryoprotectant exerts a protective effect on the membrane of spermatozoa, improving seminal quality during rabbit sperm preservation at 16°C
2D EPID dosimetry for an MR-linac: proof of concept
Purpose: At our institute, in-vivo
patient dose distributions are reconstructed for all treatments delivered using
conventional linacs from Electronic Portal Imaging Device (EPID) transit images
acquired during treatment using a simple back-projection model. Currently, the
clinical implementation of MRI-guided radiotherapy systems, which aims for
online and real-time adaptation of the treatment plan, is progressing. In our
department the MR-linac (Unity, Elekta AB, Stockholm, Sweden) is now in
clinical use. The aim of this work is to demonstrate the feasibility of 2D EPID
dosimetric verification for the MR-linac by comparing back-projected EPID doses
to ionization chamber (IC) array dose distributions.
Materials and methods:
Our conventional back projection algorithm was adapted for the MR-linac. The
most important changes involve modeling of the attenuation by and scatter from
the cryostat. The commissioning process involved the acquisition of square
field EPID measurements using various phantom setups (varying SSD, phantom
thickness and field size). Commissioning models were created for gantry 0, 90
and 180 degrees and verified by comparing EPID reconstructed 2D dose
distributions to measurements made with the OCTAVIUS 1500 IC array (PTW,
Freiburg, Germany) for 2 prostate and 1 rectum IMRT plans (25 beams total). The
average of the γ parameters (y-mean and y-pass rate) and the dose difference at
a reference point were reported. Due to their construction, the attenuation of
couch, bridge and cryostat shows a much stronger dependence on gantry angle in
the MR-linac compared to conventional linacs. We present a method to correct
for these effects. This method is validated by dose reconstruction of the 25
IMRT beams recorded at a certain gantry angle using the model of another gantry
angle, combined with the correction method.
Results: For dose verification performed at a gantry angle
identical to the commissioned model the average y-mean and y-pass rate values
(3% global dose, 2 mm, 10% isodose) were 0.37 ± 0.07 and 98.1, 95% CI [98.1 ±
2.4], respectively. The average dose difference at the reference point was
-0.5% ± 1.8%. Verification at gantry angles different from the commissioned
model (i.e., using the gantry angle dependent correction) reported 0.39 ± 0.08
and 97.6, 95% CI [96.9, 98.3] average y-mean and y-pass rate values. The
average dose difference at the reference point was: -0.1% ± 1.8%.
of MRI-guided radiotherapy systems, which aims for online and real-time adaptation of the treatment plan, is progressing. In our department the MR-linac (Unity, Elekta AB, Stockholm, Sweden) is now in clinical use. The aim of this work is to demonstrate the feasibility of 2D EPID dosimetric verification for the MR-linac by comparing back-projected EPID doses to ionization chamber (IC) array dose distributions.Biological, physical and clinical aspects of cancer treatment with ionising radiatio
Two‐dimensional EPID dosimetry for an MR‐linac: Proof of concept
Purpose: At our institute, in-vivo
patient dose distributions are reconstructed for all treatments delivered using
conventional linacs from Electronic Portal Imaging Device (EPID) transit images
acquired during treatment using a simple back-projection model. Currently, the
clinical implementation of MRI-guided radiotherapy systems, which aims for
online and real-time adaptation of the treatment plan, is progressing. In our
department the MR-linac (Unity, Elekta AB, Stockholm, Sweden) is now in
clinical use. The aim of this work is to demonstrate the feasibility of 2D EPID
dosimetric verification for the MR-linac by comparing back-projected EPID doses
to ionization chamber (IC) array dose distributions.
Materials and methods:
Our conventional back projection algorithm was adapted for the MR-linac. The
most important changes involve modeling of the attenuation by and scatter from
the cryostat. The commissioning process involved the acquisition of square
field EPID measurements using various phantom setups (varying SSD, phantom
thickness and field size). Commissioning models were created for gantry 0, 90
and 180 degrees and verified by comparing EPID reconstructed 2D dose
distributions to measurements made with the OCTAVIUS 1500 IC array (PTW,
Freiburg, Germany) for 2 prostate and 1 rectum IMRT plans (25 beams total). The
average of the γ parameters (y-mean and y-pass rate) and the dose difference at
a reference point were reported. Due to their construction, the attenuation of
couch, bridge and cryostat shows a much stronger dependence on gantry angle in
the MR-linac compared to conventional linacs. We present a method to correct
for these effects. This method is validated by dose reconstruction of the 25
IMRT beams recorded at a certain gantry angle using the model of another gantry
angle, combined with the correction method.
Results: For dose verification performed at a gantry angle
identical to the commissioned model the average y-mean and y-pass rate values
(3% global dose, 2 mm, 10% isodose) were 0.37 ± 0.07 and 98.1, 95% CI [98.1 ±
2.4], respectively. The average dose difference at the reference point was
-0.5% ± 1.8%. Verification at gantry angles different from the commissioned
model (i.e., using the gantry angle dependent correction) reported 0.39 ± 0.08
and 97.6, 95% CI [96.9, 98.3] average y-mean and y-pass rate values. The
average dose difference at the reference point was: -0.1% ± 1.8%.
of MRI-guided radiotherapy systems, which aims for online and real-time adaptation of the treatment plan, is progressing. In our department the MR-linac (Unity, Elekta AB, Stockholm, Sweden) is now in clinical use. The aim of this work is to demonstrate the feasibility of 2D EPID dosimetric verification for the MR-linac by comparing back-projected EPID doses to ionization chamber (IC) array dose distributions.Biological, physical and clinical aspects of cancer treatment with ionising radiatio