Interaction between lactose and cadmium chloride in aqueous solutions as seen by diffusion coefficients measurements

Diffusion coefficients of an aqueous system containing cadmium chloride 0.100 mol · dm−3 and lactose at different concentrations at 25 °C have been measured, using a conductimetric cell and an automatic apparatus to follow diffusion. The cell relies on an open-ended capillary method and a conductimetric technique is used to follow the diffusion process by measuring the resistance of a solution inside the capillaries, at recorded times. From these results and by ab initio calculations, it was possible to obtain a better understanding of the effect of lactose on transport of cadmium chloride in aqueous solutions

Binary Mutual Diffusion Coefficients of Isoniazid Aqueous Solutions at (298.15 and 310.15) K

Binary mutual diffusion coefficients measured by the Taylor dispersion method in two different laboratories (University of Naples, Federico II, Italy, and University of Coimbra, Portugal) are reported for aqueous solutions of isoniazid at concentrations from (0.000 to 0.100) mol·dm−3 and at two temperatures (298.15 and 310.15) K. The hydrodynamic radii for the isoniazid in aqueous solution are calculated from the experimental results. In addition, the Hartley equation and the experimental diffusion coefficients are used to estimate activity coefficients for aqueous isoniazid at both temperature

Diffusion Coefficients of Copper Chloride in Aqueous Solutions at 298.15 K and 310.15 K

Mutual diffusion coefficients (interdiffusion coefficients) and molar conductivities have been measured for copper(II) chloride in water at 298.15 K and 310.15 K at concentrations between 0.005 mol·dm-3 and 0.05 mol·dm-3. The diffusion coefficients were measured using a conductometric cell. The experimental data are discussed on the basis of the Onsager−Fuoss model. The Nernst diffusion coefficients derived from diffusion (1.297 × 10-9 and 1.690 × 10-9) m2·s-1 and from conductance (1.282 × 10-9 and 1.663 × 10-9) m2·s-1 at two temperatures (298.15 K and 310.15 K, respectively) are in good agreement

Cryopreservation of testicular tissue from the dog (Canis familiaris) and wild boar (Sus scrofa) by slow freezing and vitrification: Differences in cryoresistance according to cell type

8 Pág.Sperm cryopreservation is the most common procedure used to establish germplasm banks for endangered species - but sometimes sperm cells cannot be obtained. In such cases, freezing testicular tissue may be the only option. The testes contains germ cells at different stages of differentiation, including spermatogonia, primary spermatocytes, secondary spermatocytes, spermatids, and spermatozoa, among which differences in cryoresistance might be expected. The present work compares the viability and DNA integrity of 'rounded' cells, and of elongated spermatids and spermatozoa, from the dog and wild boar, following the cryopreservation of testicular tissue by slow freezing or vitrification. Cell viability was analyzed by PI/SYBR14 staining, and DNA integrity via the TUNEL technique. For wild boar, no significant differences were seen between the two methods with respect to the percentage of viable cells, nor in the percentage of cells with DNA damage. In the dog, the percentage of viable rounded germ cells (65.0 ± 2.4%) was higher (P < 0.05) after vitrification than after slow freezing (45.1 ± 6.7%). No difference was found between the two methods in terms of the viability of elongated cells. For rounded cells, the percentage of intact DNA was greater (P < 0.05) after vitrification (90.5 ± 2.1%) than after slow freezing (42.6 ± 11.0%), while for elongated spermatids and spermatozoa it was higher (P < 0.05) after slow freezing (66.9 ± 6.1%) than after vitrification (50.7 ± 4.5%). Thus, the response to cryopreservation is cell type-, cryopreservation type-, and species-dependent. Vitrification would appear to be the most appropriate method for preserving dog testicular tissue given the associated high cell viability and low degree of DNA fragmentation, while in wild boar, either method might be used.This study was funded by grant PID2020-113288RB-100/AEI/10.13039/501100011033.Peer reviewe

Transcriptome profiling of grapevine seedless segregants during berry development reveals candidate genes associated with berry weight

Indexación: Web of Science; PubMedBackground Berry size is considered as one of the main selection criteria in table grape breeding programs. However, this is a quantitative and polygenic trait, and its genetic determination is still poorly understood. Considering its economic importance, it is relevant to determine its genetic architecture and elucidate the mechanisms involved in its expression. To approach this issue, an RNA-Seq experiment based on Illumina platform was performed (14 libraries), including seedless segregants with contrasting phenotypes for berry weight at fruit setting (FST) and 6–8 mm berries (B68) phenological stages. Results A group of 526 differentially expressed (DE) genes were identified, by comparing seedless segregants with contrasting phenotypes for berry weight: 101 genes from the FST stage and 463 from the B68 stage. Also, we integrated differential expression, principal components analysis (PCA), correlations and network co-expression analyses to characterize the transcriptome profiling observed in segregants with contrasting phenotypes for berry weight. After this, 68 DE genes were selected as candidate genes, and seven candidate genes were validated by real time-PCR, confirming their expression profiles. Conclusions We have carried out the first transcriptome analysis focused on table grape seedless segregants with contrasting phenotypes for berry weight. Our findings contributed to the understanding of the mechanisms involved in berry weight determination. Also, this comparative transcriptome profiling revealed candidate genes for berry weight which could be evaluated as selection tools in table grape breeding programs.http://bmcplantbiol.biomedcentral.com/articles/10.1186/s12870-016-0789-

Dependence of viscosity and diffusion on β-cyclodextrin and chloroquine diphosphate interactions

Mutual diffusion coefficients of chloroquine diphosphate (CDP) in aqueous solutions both without and with β-cyclodextrin (β-CD) were measured at concentrations from (0.0000 to 0.0100) mol dm−3 and 298.15 K, using the Taylor dispersion technique. Ternary mutual diffusion coefficients (Dik) measured by the same technique are reported for aqueous CDP + β-CD solutions at 298.15 K. The presence of β CD led to relevant changes in the diffusion process, as showed by nonzero values of the cross-diffusion coefficients, D12 and D21 . β-CD concentration gradients produced significant co-current coupled flows of CDP. In addition, the effects of β-CD on the transport of CDP are assessed by comparing the binary diffusion coefficient of aqueous CDP solutions with the main diffusion coefficient (D11 ) measured for ternary {CDP(1) + β-CD(2)} solutions. These observations are supported by viscosity analysis. All data allow to have a better interpretation on the effect of cyclodextrin on the transport behavior of CDP. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Coimbra Chemistry Centre - FundacAo para a Ciencia e a Tecnologia (FCT), Portuguese Agency for Scientific Research [UID/QUI/UI0313/2019]; COMPETE; Ministry of Education, Youth and Sports of the Czech Republic DKRVO [RP/CPS/2020/003]; University of Alcala (Spain)RP/CPS/2020/003; UID/QUI/UI0313/2019; Fundação para a Ciência e a Tecnologia, FCT; Universidad de Alcalá, UAH; Programa Operacional Temático Factores de Competitividade, POF

Mutual and self-diffusion of charged porphyrines in aqueous solutions

a b s t r a c t We have investigated the diffusion properties for an ionic porphyrin in water. Specifically, for the {tetra-sodium tetraphenylporphyrintetrasulfonate (Na 4 TPPS) + water} binary system, the self-diffusion coefficients of TPPS 4À and Na + , and the mutual diffusion coefficients were experimentally determined as a function of Na 4 TPPS concentration from (0 to 4) Á 10 À3 mol Á dm À3 at T = 298.15 K. Absorption spectra for this system were obtained over the same concentration range. Molecular mechanics were used to compute size and shape of the TPPS 4À porphyrin. We have found that, at low solute concentrations ), the mutual diffusion coefficient sharply decreases as the concentration increases. This can be related to both the ionic nature of the porphyrin and complex associative processes in solution. Our experimental results are discussed on the basis of the Nernst equation, Onsager-Fuoss theory and porphyrin metal ion association. In addition, self-diffusion of TPPS 4À was used, together with the Stokes-Einstein equation, to determine the equivalent hydrodynamic radius of TPPS 4À . By approximating this porphyrin to a disk, we have estimated structural parameters of TPPS 4À . These were found to be in good agreement with those obtained using molecular mechanics. Our work shows how the self-diffusion coefficient of an ionic porphyrin in water is substantially different from the corresponding mutual-diffusion coefficient in both magnitude and concentration dependence. This aspect should be taken into account when diffusion-based transport is modelled for in vitro and in vivo applications of pharmaceutical relevance

Comparison of three different staining methods for the assessment of epididymal red deer sperm morphometry by computerized analysis with ISAS®

When collection of ejaculated sperm samples is not possible, as is the case with wild species, the epididymides of sacrificed wild males become the only possible source of spermatozoa. Mature cauda epididymal spermatozoa display characteristics similar to those of ejaculated sperm cells. The present work proposes a sperm staining technique suitable for the morphometric evaluation of red deer epididymal sperm using a new computerized system. Epididymides from wild animals were extracted no later than 2 h post mortem. After epididymal sectioning, sperm samples were collected, cooled to and equilibrated at 5 °C, and frozen in liquid nitrogen. Before staining, sperm samples were thawed for 20 s at 37 °C, and used for the preparation of slides. Three different sperm stains were tested: Hemacolor, Diff-Quik, and Harris’ Hematoxylin. Morphometric analyses of sperm samples were performed using the morphologic module of the ISAS®. Two hundred spermatozoa per sample and stain were captured at random and analyzed. Sperm morphometric values were significantly affected by the staining technique used. Moreover, significant differences were observed between animals. In our study, Diff-Quik could be considered to be the best sperm staining method, as it provided the highest percentage of well automatically analyzed cells by the ISAS®, and discriminates better between animals. This sperm staining technique also proved to be a useful method for characterizing and discriminating between sperm samples of different animals.This study was partially supported by the Ministerio de Ciencia y Tecnología, INIA (RZ01-008).Peer reviewe

Premelting of ice adsorbed on a rock surface

Considering ice-premelting on a quartz rock surface (i.e. silica) we calculate the Lifshitz excess pressures in a four layer system with rock–ice–water–air. Our calculations give excess pressures across (1) ice layer, (2) water layer, and (3) ice–water interface for different ice and water layer thicknesses. We analyse equilibrium conditions where the different excess pressures take zero value, stabilized in part by repulsive Lifshitz interactions. In contrast to previous investigations which considered varying thickness of only one layer (ice or water), here we present theory allowing for simultaneous variation of both layer thicknesses. For a given total thickness of ice and water, this allows multiple alternative equilibrium solutions. Consequently the final state of a system will depend on initial conditions and may explain variation in experimental measurements of the thicknesses of water and ice layers

Slow and ultra-rapid freezing protocols for cryopreserving roe deer (Capreolus capreolus) epididymal sperm collected at different times of year

10 Pág. Centro de Investigación en Sanidad Animal (CISA) / Departamento de Reproducción animalThe roe deer is a monoestrous species with a very short rutting season. The present work reports the most suitable period for collecting epididymal sperm and describes the effect of two cooling rates on the post-thaw quality of sperm. Testes were collected 24–48 h after death. Samples of sperm flushed from the epididymis were subjected to either (1) dilution in a Tris-citric acid-glucose-egg yolk-based medium with glycerol, and slow freezing in straws, or (2) dilution in the same extender but replacing the glycerol with 100 mM of sucrose, and ultra-rapid freezing in pellets. Sperm motility, acrosome and membrane integrity, morphometry and morphological abnormalities were analysed before and after cryopreservation. Spermatogenic activity was investigated via histological examination of testis sections. Several testes collected between April, May and September showed no spermatogenic activity. All those collected in June–August showed spermatogenic activity. No significant difference was detected in the cryoresistance ratios associated with the conventional slow freezing, between sperm collected during the pre-rutting (April–May) and rutting (June–August) periods. No significant differences were seen between the slow-frozen-thawed and the ultra-rapid-frozen-thawed sperm in terms of percentage of viable sperm or the percentage of sperm with morphological abnormalities. Slow freezing returned significantly better (P<0.05) values for post-thaw acrosome integrity (43.3% vs. 25.0%) and straight-line velocity (19 μm/s vs. 4 μm/s). For both freezing methods, sperm heads were smaller post-thawing than pre-freezing (P<0.001). In conclusion, both the pre-rutting and rutting season are suitable periods for freezing roe deer sperm. Ultra-rapid freezing did not provide suitable results.This research was funded by MINECO/AEI/FEDER and EU grant AGL2017-85753-R. P. Bóveda was the recipient of a grant for pre-doctoral researchers from MINECO (AEI/FSE, UE). Octavio Mejía was the recipient of a research fellowship from the PASPA-DGAPA-UNAM (México). V.N. Flores-Gil was funded by FONDECYT-CONCYTEC (grant contract number 000245-2015-FONDECYT).Peer reviewe