Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 198
Filtrar
1.
Biol Reprod ; 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38832705

RESUMO

Following blastocyst hatching, ungulate embryos undergo a prolonged preimplantation period termed conceptus elongation. Conceptus elongation constitutes a highly susceptible period for embryonic loss and the embryonic requirements during this process are largely unknown, but multiple lipid compounds have been identified in the fluid nourishing the elongating conceptuses. Peroxisome proliferator-activated receptors (PPARs) mediate the signaling actions of prostaglandins and other lipids and, between them, PPARG has been pointed out to play a relevant role on conceptus elongation by a functional study that depleted PPARG in both uterus and conceptus. The objective of this study has been to determine if embryonic PPARG is required for bovine embryo development. To that aim, we have generated bovine PPARG KO embryos in vitro by two independent gene ablation strategies and assess their developmental ability. In vitro development to Day (D) 8 blastocyst was unaffected by PPARG ablation, as total, inner cell mass and trophectoderm cell numbers were similar between WT and KO D8 embryos. In vitro post-hatching development to D12 was also comparable between different genotypes, as embryo diameter, epiblast cell number, and embryonic disc formation and hypoblast migration rates were unaffected by the ablation. The development to tubular stages equivalent to E14 was assessed in vivo, following a heterologous embryo transfer experiment, observing that the development of extra-embryonic membranes and of the embryonic disc was not altered by PPARG ablation. In conclusion, PPARG ablation did not impaired bovine embryo development up to tubular stages.

2.
Liver Int ; 44(4): 996-1010, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38293766

RESUMO

BACKGROUND AND AIMS: We evaluated tolerogenic C-type lectin LSECtin loss in cirrhosis and its potential regulation by cytokines. METHODS: Liver tissue from patients with cirrhosis and healthy controls, immortalised and generated LSECtin-CRISPR immortalised LSECs, and murine primary LSECs from the CCl4 model were handled. RESULTS: LSECtin expression was reduced in liver tissue from cirrhotic patients, and it decreased from compensated to decompensated disease. Increased phosphorylation of MAPK, Akt and NFkB was observed upon LSECtin stimulation in LSEC murine cell line, showing a pattern of inflammatory and chemotactic cytokines either restrained (IL-10, CCL4) or unrestrained (TNF-α, IL-1ß, IL-6, CCL2). CD44 attenuated whereas LAG-3 increased all substrates phosphorylation in combination with TLR4 and TLR2 ligands except for NFkB. TNF-α, IL-1 ß, IL-6 and CCL2 were restrained by LSECtin crosslinking on TLRs studied. Conversely, IL-10 and CCL4 were upregulated, suggesting a LSECtin-TLRs synergistic effect. Also, LSECtin was significantly induced after IL-13 stimulation or combined with anti-inflammatory cytokines in cirrhotic and immortalised LSECs. Th17 and regulatory T cells were progressively increased in the hepatic tissue from compensated to decompensated patients. A significant inverse correlation was present between gene expression levels of CLEC4G/LSECtin and RORγT and FOXP3 in liver tissues. CONCLUSION: LSECtin restrains TLR proinflammatory secretome induced on LSECs by interfering immune response control, survival and MAPKs signalling pathways. The cytokine-dependent induction of LSECtin and the association between LSECtin loss and Th17 cell subset expansion in the liver, provides a solid background for exploring LSECtin retrieval as a mechanism to reprogram LSEC homeostatic function hampered during cirrhosis.


Assuntos
Citocinas , Interleucina-10 , Humanos , Camundongos , Animais , Citocinas/metabolismo , Interleucina-6/metabolismo , Fator de Necrose Tumoral alfa , Secretoma , Cirrose Hepática , NF-kappa B/metabolismo , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo
3.
Nature ; 554(7693): 493-496, 2018 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-29414939

RESUMO

Every star-forming galaxy has a halo of metal-enriched gas that extends out to at least 100 kiloparsecs, as revealed by the absorption lines that this gas imprints on the spectra of background quasars. However, quasars are sparse and typically probe only one narrow beam of emission through the intervening galaxy. Close quasar pairs and gravitationally lensed quasars have been used to circumvent this inherently one-dimensional technique, but these objects are rare and the structure of the circumgalactic medium remains poorly constrained. As a result, our understanding of the physical processes that drive the recycling of baryons across the lifetime of a galaxy is limited. Here we report integral-field (tomographic) spectroscopy of an extended background source-a bright, giant gravitational arc. We can thus coherently map the spatial and kinematic distribution of Mg ɪɪ absorption-a standard tracer of enriched gas-in an intervening galaxy system at redshift 0.98 (around 8 billion years ago). Our gravitational-arc tomography unveils a clumpy medium in which the absorption strength decreases with increasing distance from the galaxy system, in good agreement with results for quasars. Furthermore, we find strong evidence that the gas is not distributed isotropically. Interestingly, we detect little kinematic variation over a projected area of approximately 600 square kiloparsecs, with all line-of-sight velocities confined to within a few tens of kilometres per second of each other. These results suggest that the detected absorption originates from entrained recycled material, rather than in a galactic outflow.

4.
Appl Opt ; 62(1): 108-116, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36606852

RESUMO

The development and deployment of a real-time, in situ, non-invasive sensor to monitor the concentration of H 2 O during in situ combustion (ISC) experiments with a heavy-crude oil is described. A real-time sensor to monitor the gas-phase products from ISC can support the study of the kinetics of the complex chemical reactive system in ISC. The mole fraction of H 2 O was measured using tunable diode laser (TDL) absorption spectroscopy coupled with 1f-normalized wavelength modulation spectroscopy (WMS) and 2f detection. The WMS 2f/1f strategy was used to enhance sensitivity with effective noise rejection, particularly suitable when characterizing the water vapor evolved from oil-water emulsions. H 2 O was measured at 3934.10c m -1 from the fundamental band v 3. That transition was selected using the HITRAN database to increase the line strength and minimize interference from neighbor compounds. Measurements of H 2 O concentration were conducted at ambient temperature and pressure using a reference cell (H 2 O=2% at 98.6 kPa) to validate the sensor architecture under controlled laboratory environments. The TDL sensor was also successfully validated during real ISC experiments involving heavy-crude oil. Validation and combustion experiments showed the potential of the TDL-based sensor for non-invasive, real-time, in situ measurements of gas-phase species in conditions similar to those of laboratory-scale experimental ISC tests.

5.
Sensors (Basel) ; 22(6)2022 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-35336337

RESUMO

Hyperspectral Imaging (HSI) techniques have demonstrated potential to provide useful information in a broad set of applications in different domains, from precision agriculture to environmental science. A first step in the preparation of the algorithms to be employed outdoors starts at a laboratory level, capturing a high amount of samples to be analysed and processed in order to extract the necessary information about the spectral characteristics of the studied samples in the most precise way. In this article, a custom-made scanning system for hyperspectral image acquisition is described. Commercially available components have been carefully selected in order to be integrated into a flexible infrastructure able to obtain data from any Generic Interface for Cameras (GenICam) compliant devices using the gigabyte Ethernet interface. The entire setup has been tested using the Specim FX hyperspectral series (FX10 and FX17) and a Graphical User Interface (GUI) has been developed in order to control the individual components and visualise data. Morphological analysis, spectral response and optical aberration of these pushbroom-type hyperspectral cameras have been evaluated prior to the validation of the whole system with different plastic samples for which spectral signatures are extracted and compared with well-known spectral libraries.


Assuntos
Algoritmos , Cintilografia
6.
Br Poult Sci ; 63(2): 244-251, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34297642

RESUMO

1. Birchen and Blue Leonesa are two endangered chicken breeds mainly raised in Curueño Valley in North Spain. The establishment of a germplasm bank to guarantee the preservation of these breeds is needed. However, cockerels from different breeder flocks can show variance in semen cryoresistance.2. The following work focused on the sperm characterisation and cryopreservation of Birchen and Blue Leonesa cockerels from four different breeders. A total of 30 semen pools were analysed. Besides conventional sperm analysis, including motility by computer-aided sperm analysis (CASA) and DNA fragmentation by TUNEL, the present study tested a double staining method (MitoTrackerTM Green FM/propidium iodide). This gave simultaneous assessment of plasma and acrosomal and mitochondrial membranes, which were previously validated by SYBR-14/PI, CASA, aniline blue and TUNEL.3. No significant differences were found among fresh semen variables between breeds and breeders. For post-thawed variables, significant differences (P < 0.05) were found between breeders in sperm viability (58.0 ± 1.90 breeder D vs. 35.2 ± 7.41 breeder A, 37.2 ± 4.09 breeder B and 22.3 ± 5.92 breeder C) and DNA fragmentation (62.4 ± 9.91 breeder C vs. 31.8 ± 7.08 breeder B and 24.5 ± 5.49 breeder D). The lowest DNA fragmentation values for semen from breeder D birds were coincident with higher integrity of the mitochondrial membrane.4. The results revealed higher sperm cryoresistance in the cockerels from one of the breeders, possibly due to differences in management system (e.g. diet, housing, control of stress elements and pathogens, reproduction practices or maintenance of genetic diversity). These differences may determine the sperm freezability, and thus the effectiveness of developing a germplasm bank.


Assuntos
Preservação do Sêmen , Animais , Galinhas/genética , Criopreservação/métodos , Criopreservação/veterinária , Masculino , Melhoramento Vegetal , Análise do Sêmen/veterinária , Preservação do Sêmen/métodos , Preservação do Sêmen/veterinária , Motilidade dos Espermatozoides , Espermatozoides
7.
Reprod Domest Anim ; 55(7): 805-813, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32311171

RESUMO

This study examines the effect of L-carnitine (LC) on chilled ram semen stored for up to 96 hr. Semen samples were collected, placed in a skimmed milk + 6% egg yolk extender, pooled, aliquoted and diluted with the same extender supplemented with different LC concentration: 0 (control), 1 mM (LC1), 2.5 mM (LC2.5), 5 mM (LC5), 7.5 mM (LC7.5) or10 mM (LC10). Sperm kinetics and membranes (plasma, acrosome and mitochondrial) were examined using the CASA system and triple fluorescence staining (PI/ PNA-FITC/Mitotracker). The progressive motility was greater (p < .05) with LC7.5 treatment than the control sperm at 96 hr. The curvilinear velocity (p < .01) and the percentage of sperm with intact membranes (plasma/acrosome/mitochondria) (p < .01) were greater with all LC treatments than the control group at all times. Straight line velocity was greater (p < .01) with LC5 and LC7.5 treatments than the control group after 48 hr. The LC5 group also returned lower ALH values (p < .05) than these seen for the control groups after 48 hr. The fertilizing capacity of LC5 samples stored at 15°C for 2 hr (LC5-15°C-2h) and at 5°C for 24 hr (LC5-5°C-24h) was tested in three ewe groups via cervical fixed-time artificial insemination. In two groups, the fertilizing capacity of the LC5-5°C-24h was reduced (p < .001). In the remaining group, however, no significant difference was seen between the LC5-15°C-2h and LC5-5°C-24h sperm in this respect (pregnancy rates 52.4% versus 42.8%; p > .05). Overall, the present results suggest that supplementing skimmed milk-egg yolk-based extenders with LC has a positive effect on chilled sperm variables and fertilizing capacity.


Assuntos
Carnitina/farmacologia , Preservação do Sêmen/veterinária , Espermatozoides/efeitos dos fármacos , Acrossomo , Animais , Membrana Celular , Feminino , Inseminação Artificial/veterinária , Masculino , Gravidez , Análise do Sêmen/veterinária , Preservação do Sêmen/métodos , Carneiro Doméstico , Motilidade dos Espermatozoides/efeitos dos fármacos
8.
Sensors (Basel) ; 20(21)2020 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-33126521

RESUMO

Multispectral imaging (MI) techniques are being used very often to identify different properties of nature in several domains, going from precision agriculture to environmental studies, not to mention quality inspection of pharmaceutical production, art restoration, biochemistry, forensic sciences or geology, just to name some. Different implementations are commercially available from the industry and yet there is quite an interest from the scientific community to spread its use to the majority of society by means of cost effectiveness and ease of use for solutions. These devices make the most sense when combined with unmanned aerial vehicles (UAVs), going a step further and alleviating repetitive routines which could be strenuous if traditional methods were adopted. In this work, a low cost and modular solution for a multispectral camera is presented, based on the use of a single panchromatic complementary metal oxide semiconductor (CMOS) sensor combined with a rotating wheel of interchangeable band pass optic filters. The system is compatible with open source hardware permitting one to capture, process, store and/or transmit data if needed. In addition, a calibration and characterization methodology has been developed for the camera, allowing not only for quantifying its performance, but also able to characterize other CMOS sensors in the market in order to select the one that best suits the budget and application. The process was experimentally validated by mounting the camera in a Dji Matrice 600 UAV to uncover vegetation indices in a reduced area of palm trees plantation. Results are presented for the normalized difference vegetation index (NDVI) showing a generated colored map with the captured information.

9.
J Zoo Wildl Med ; 51(1): 196-201, 2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32212563

RESUMO

This article describes the urinogenital condition of three female Iberian ibexes (Capra pyrenaica-one infertile 3-yr-old adult and two prepubertal animals aged 1 (PP1) and 2 (PP2) yr, respectively, all raised in captivity. All showed constant urinal dribbling, leading to ulcerative dermatitis in the vulvar area. Housed in a stable with other females, the adult did not become pregnant after male contact in either of two consecutive mating seasons. Vaginoscopy and laparoscopic exploration performed on the prepubertal females revealed abnormalities of the vagina and urinary bladder. Ultrasound examination revealed atrophy of the left kidney in the adult female and PP1, and of the right kidney in PP2, with degeneration of the renal pelvis. A paraovarian cyst with hydrosalpinx was also detected in the left oviduct of the adult female. Postmortem analysis of the adult and PP2, which shared a mother, confirmed an extramural single ectopic ureter with vaginal insertion associated with atrophy of the ipsilateral kidney. Though PP1 was officially unrelated to the latter animals, all three might have had a common ancestor in their lineages.


Assuntos
Infertilidade/veterinária , Nefropatias/veterinária , Ureter/anormalidades , Animais , Animais de Zoológico , Atrofia/patologia , Atrofia/veterinária , Feminino , Cabras/anormalidades , Infertilidade/etiologia , Nefropatias/diagnóstico , Nefropatias/patologia , Espanha , Ureter/patologia
10.
Phys Chem Chem Phys ; 21(9): 5086-5096, 2019 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-30762849

RESUMO

The formation of heterostructures has proven to be a viable way to achieve high photoelectrochemical water splitting efficiencies with BiVO4 based photoanodes. Especially, cobalt and nickel based oxides are suitable low cost contact materials. However, the exact role of these contact materials is not yet completely understood because of the difficulty to individually quantify the effects of surface passivation, charge carrier separation and catalysis on the efficiency of a heterostructure. In this study, we used photoelectron spectroscopy in combination with in situ thin film deposition to obtain direct information on the interface structure between polycrystalline BiVO4 and NiO, CoOx and Sn-doped In2O3 (ITO). Strong upwards band bending was observed for the BiVO4/NiO and BiVO4/CoOx interfaces without observing chemical changes in BiVO4, while limited band bending and reduction of Bi and V was observed while forming the BiVO4/ITO interface. Thus, the tunability of the Fermi level position within BiVO4 seems to be limited to a certain range. The feasibility of high upwards band bending through junctions with high work function (WF) compounds demonstrate that nickel oxide and cobalt oxide are able to enhance the charge carrier separation in BiVO4. Similar studies could help to identify whether new photoelectrode materials and their heterostructures would be suitable for photoelectrochemical water splitting.

11.
Cryobiology ; 91: 84-89, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31628908

RESUMO

The present study compares a protocol that mimics freezing of ram semen in static nitrogen vapor with two protocols with an initial low cooling rate in the first step, followed by higher cooling rates where ice nucleation occurs. Semen ejaculates, obtained from twelve adults rams, were diluted with TEST-based extender and frozen with either Protocol 1 (three-step decelerating cooling): from +5 °C to -35 °C (40 °C/min), from -35 °C to -65 °C (17 °C/min), and then from -65 °C to -85 °C (3 °C/min); or Protocol 2 (three-step accelerating cooling): from +5 °C to -5 °C (4 °C/min), from -5 °C to -110 °C (25 °C/min), and then from -110 °C to -140 °C (35 °C/min); or Protocol 3 (two-step accelerating cooling), from +5 °C to -10 °C (5 °C/min), and then from -10 °C to -130 °C (60 °C/min). Post-thaw sperm quality was reduced for all protocols (p < .05) compared with fresh semen. Post-thaw percentages of sperm motility characteristics and sperm with intact plasma membrane, intact acrosome, and intact mitochondrial membrane were greater using Protocol 3 than Protocol 2 (p < .05) and Protocol 1 (p < .01). In addition, the post-thaw percentage of sperm with fragmented DNA was lower (p < .05) using Protocol 3 compared with Protocol 1. The present results indicate that a cooling rate of 60 °C/min around and after the time point of ice nucleation provided better post thaw survival and function of ram sperm than lower (and/or decelerating) cooling rates.


Assuntos
Acrossomo/fisiologia , Criopreservação/métodos , Fragmentação do DNA/efeitos dos fármacos , Preservação do Sêmen/métodos , Sêmen/fisiologia , Animais , Membrana Celular , DNA , Congelamento , Humanos , Masculino , Análise do Sêmen , Ovinos , Motilidade dos Espermatozoides/fisiologia
12.
New Phytol ; 217(3): 1307-1321, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29139551

RESUMO

Most plant leaves exhibit bilateral symmetry, which has been hypothesized as an inevitable consequence of the existence of the proximodistal and dorsoventral axes. No gene has been described that affects leaf bilateral symmetry but not dorsoventrality in Arabidopsis thaliana. We screened for viable insertional mutations that affect leaf morphology, and out of more than 700 mutants found only one, desigual1-1 (deal1-1), that exhibited bilateral symmetry breaking but no obvious defects in dorsoventrality. We found that deal1-1 is an allele of VASCULATURE COMPLEXITY AND CONNECTIVITY (VCC). Several overlapping regulatory pathways establish the interspersed lobes and indentations along the margin of Arabidopsis thaliana leaves. These pathways involve feedback loops of auxin, the PIN-FORMED1 (PIN1) auxin efflux carrier, and the CUP-SHAPED COTYLEDON2 (CUC2) transcriptional regulator. Early vcc (deal1) leaf primordia fail to acquire bilateral symmetry and instead form ectopic lobes and sinuses. The vcc leaves show aberrant recruitment of marginal cells expressing properly polarized PIN1, resulting in misplaced auxin maxima. Normal PIN1 polarization requires CUC2 expression and CUC2 genetically interacts with VCC; VCC also affects CUC2 expression. VCC has a domain of unknown function, DUF1218, and localizes to the endoplasmic reticulum membrane. VCC acts partially redundantly with its two closest paralogs, DEAL2 and DEAL3, in early leaf margin patterning and is required for bilateral symmetry, but its loss of function does not visibly affect dorsoventrality.


Assuntos
Arabidopsis/anatomia & histologia , Arabidopsis/genética , Padronização Corporal/genética , Genes de Plantas , Família Multigênica , Folhas de Planta/anatomia & histologia , Folhas de Planta/genética , Proliferação de Células , Retículo Endoplasmático/metabolismo , Epistasia Genética , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos/metabolismo , Mutação/genética , Fenótipo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Frações Subcelulares/metabolismo
13.
Tumour Biol ; 40(11): 1010428318810059, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30419802

RESUMO

A complex network of chemokines can influence cancer progression with the recruitment and activation of hematopoietic cells, including macrophages to the supporting tumor stroma promoting carcinogenesis and metastasis. The aim of this study was to investigate the relation between tissue and plasma chemokine levels involved in macrophage recruitment with tumor-associated macrophage profile markers and clinicopathological features such as tumor-node-metastases stage, desmoplasia, tumor necrosis factor-α, and vascular endothelial growth factor plasma content. Plasma and tumor/healthy mucosa were obtained from Chilean patients undergoing colon cancer surgery. Chemokines were evaluated from tissue lysates (CCL2, CCL3, CCL4, CCL5, and CX3CL1) by Luminex. Statistical analysis was performed using Wilcoxon match-paired test ( p < 0.05). Macrophage markers (CD68, CD163, and iNOS) were evaluated by immunohistochemistry samples derived from colorectal cancer patients. Correlation analysis between chemokines and macrophage markers and clinicopathological features were performed using Spearman's test. Plasmatic levels of chemokines and inflammatory mediators' vascular endothelial growth factor and tumor necrosis factor-α were evaluated by Luminex. Tumor levels of CCL2 (mean ± standard deviation = 530.1 ± 613.9 pg/mg), CCL3 (102.7 ± 106.0 pg/mg), and CCL4 (64.98 ± 48.09 pg/mg) were higher than those found in healthy tissue (182.1 ± 116.5, 26.79 ± 22.40, and 27.06 ± 23.69 pg/mg, respectively p < 0.05). The tumor characterization allowed us to identify a positive correlation between CCL4 and the pro-tumor macrophages marker CD163 ( p = 0.0443), and a negative correlation of iNOS with desmoplastic reaction ( p = 0.0467). Moreover, we identified that tumors with immature desmoplasia have a higher CD163 density compared to those with a mature/intermediated stromal tissue ( p = 0.0288). Plasmatic CCL4 has shown a positive correlation with inflammatory mediators (tumor necrosis factor-α and vascular endothelial growth factor) that have previously been associated with poor prognosis in patients. In conclusion High expression of CCL4 in colon cancer could induce the infiltration of tumor-associated macrophages and specifically a pro-tumor macrophage profile (CD163+ cells). Moreover, plasmatic chemokines could be considered inflammatory mediators associated to CRC progression as well as tumor necrosis factor-α and vascular endothelial growth factor. These data reinforce the idea of chemokines as potential therapeutic targets or biomarker in CRC.


Assuntos
Biomarcadores Tumorais/metabolismo , Quimiocina CCL2/metabolismo , Quimiocina CCL3/metabolismo , Quimiocina CCL4/metabolismo , Neoplasias Colorretais/patologia , Macrófagos/patologia , Microambiente Tumoral , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Neoplasias Colorretais/metabolismo , Feminino , Seguimentos , Humanos , Macrófagos/metabolismo , Masculino , Pessoa de Meia-Idade , Prognóstico
14.
Cryobiology ; 80: 12-17, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29352980

RESUMO

The rate at which lethal intracellular ice forms during sperm cryopreservation is highly dependent on the cooling protocol. The present work compares two cooling protocols for use with Iberian ibex (Capra pyrenaica) sperm by assessing the effects on the motility, viability, and size of frozen-thawed sperm cells. Ejaculates, obtained from six adult ibex males via transrectal, ultrasound-guided massage of the accessory sex glands plus electroejaculation if necessary, were cooled via either 1) Protocol 1 (decelerating cooling), involving cooling in liquid nitrogen vapor from 5 °C to -35 °C (40 °C/min), from -35 °C to -65 °C (17 °C/min), and then from -65 °C to -85 °C (3 °C/min); or 2) Protocol 2 (accelerating cooling) involving cooling in a biological freezer from 5 °C to -5 °C (4 °C/min), from -5 °C to -110 °C (25 °C/min), and then from -110 °C to -140 °C (35 °C/min). Compared to fresh ejaculates, sperm quality at thawing was found to be reduced by both protocols (p < .05), but especially by Protocol 1. Sperm head size was also significantly reduced by both protocols, although the Protocol 1 sperm heads were also significantly smaller than those of Protocol 2 sperms heads (p < .05). In fresh sperm samples, clustering analyses revealed two subpopulations of sperms with different morphometric characteristics, SP1 with larger cells, and SP2 with smaller cells. Both cooling protocols caused reduction in the proportion of SP1 cells, and an increase in the proportion of SP2 cells. In conclusion, the decelerating cooling protocol (Protocol 1) caused greater cryodamage to the sperm cells than the accelerating protocol (Protocol 2).


Assuntos
Criopreservação/métodos , Preservação do Sêmen/métodos , Espermatozoides , Animais , Criopreservação/veterinária , Cabras , Masculino , Preservação do Sêmen/veterinária , Cabeça do Espermatozoide , Temperatura
15.
Appl Opt ; 57(23): 6707-6716, 2018 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-30129616

RESUMO

A tunable diode laser-based sensor is reported to monitor carbon monoxide (CO) concentration under conditions similar to those of laboratory-scale tests used to characterize the behavior of heavy crude oil during in situ combustion (ISC). The sensor uses a DFB diode laser operating over the spectral range of the rotational transition R(11) of the first overtone, wherein simulations of spectral absorption bands for CO, CO2, and H2O showed minimal spectral interference. The absorption spectra were calculated using the HiTran 2008 database at temperatures varying between 150°C and 800°C, pressures from 1 to 5 atm, and the typical concentration of major species in ISC characterization experiments. The measurements of CO concentration were conducted at ambient temperature and pressure in a static glass cell of borosilicate, with a path length of 3.81 cm, to validate the CO sensor architecture under controlled laboratory environments. The calibration curve for CO obtained by quantifying the optical density at the line center of R(11) for a molar-concentration range between 0.7% and 3.4% demonstrated a linear response (coefficient of determination of 0.9986). Experiments at 4 atm and 600 K were carried out in a custom-designed optical chamber with two optical wedged sapphire windows (2°) to avoid the etalon effect. CO-absorption spectra were validated by a comparative study with the HiTran database, while a calibration-free methodology using scanned-wavelength direct absorption was investigated for future characterizing experiments involving ISC. Signal to noise ratios (SNRs) were above 40 in the optical chamber and higher than 14 in the glass cell. The TDL sensor was also successfully validated during real ISC experiments involving Colombian heavy crude oil. The calibration and oxidation experiments showed the potential of TDL-based sensors in the region of 2.3 µm for non-invasive, real-time, and in situ measurements of carbon monoxide generated at similar conditions to those of lab-scale experimental ISC tests.

16.
J Cardiothorac Vasc Anesth ; 32(1): 236-244, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28803768

RESUMO

OBJECTIVES: The aim of this study was to measure the level of preoperative anxiety in patients scheduled for cardiac surgery, identify any influencing clinical factors, and assess the relationship between anxiety and postoperative morbidity. DESIGN: A prospective and consecutive study. SETTING: A single university hospital. PARTICIPANTS: The study comprised 200 patients scheduled for cardiac surgery. INTERVENTIONS: Each patient was asked to grade his or her preoperative anxiety level using the Visual Analogue Scale for Anxiety, Amsterdam Preoperative Anxiety and Information Scale, and set of specific anxiety-related questions. Demographic data (age, sex, body mass index) and anesthetic and surgical data (American Society of Anesthesiologists physical status, EuroSCORE surgical risk, preoperative length of stay, and previous anesthetic experience) were registered. Also, postoperative morbidity was assessed. MEASUREMENTS AND MAIN RESULTS: Twenty-eight percent of the patients developed high preoperative anxiety. The mean Amsterdam Preoperative Anxiety and Information Scale score was 11.4 ± 4.3, and the mean Visual Analogue Scale for Anxiety score was 48 ± 21. Patients scheduled for coronary artery bypass surgery, who had no previous anesthetic experience, and who were hospitalized before surgery, had higher anxiety scores. Coronary bypass surgery (odds ratio 3.026; 1.509-6.067; p = 0.002) was associated independently with preoperative high-level anxiety. Anxiety most commonly was caused by waiting for surgery, not knowing what is happening, fearing not being able to awaken from anesthesia, and being at the mercy of staff. Anxiety did not modify the postoperative course. CONCLUSIONS: In patients waiting to undergo cardiac surgery, both fear of the unknown and lack of information, especially related to the surgery, are crucial factors in high levels of preoperative anxiety in cardiac surgery. Coronary bypass surgery is a determining factor for preoperative anxiety. The anxiety level did not modify the postoperative course in these patients.


Assuntos
Ansiedade/epidemiologia , Ansiedade/psicologia , Procedimentos Cirúrgicos Cardíacos/psicologia , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/psicologia , Cuidados Pré-Operatórios/psicologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Ansiedade/diagnóstico , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Morbidade , Complicações Pós-Operatórias/diagnóstico , Cuidados Pré-Operatórios/métodos , Estudos Prospectivos , Fatores de Risco
17.
Br J Neurosurg ; 32(6): 619-627, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30260251

RESUMO

Background: A prospective, randomized, double-blind study was designed to assess differences in brain relaxation between 2 doses of 3% HS during elective supratentorial brain tumour surgery.Methods: 60 patients undergoing supratentorial craniotomy for tumour resection were enrolled to receive either 3 mL/kg (group L) or 5 mL/kg (group H) of 3% HS administered at skin incision. Brain relaxation was assessed after dura opening on a scale ranging 1-4 (1 = perfectly relaxed, 2 = satisfactorily relaxed, 3 = firm brain, 4 = bulging brain). Hemodynamic variables and laboratory values (blood gases, osmolarity, haematocrit, and lactate) were collected before HS infusion and 30, 120 and 360 min after it. Presence of midline shift, postoperative complications, PCU and hospital stay, and mortality after 30 days were also recorded.Results: There was no difference in brain relaxation, with 2.0 (1.0-3.0) and 2.0 (1.0-2.3) (P = 0.535) for patients in groups L and H, respectively. If adjusted for the presence of midline shift, 50% of patients had adequate brain relaxation scores (grades 1 and 2) in group L and 61% in group H (OR 0.64, CI = 0.16-2.49, P = 0.515). No significant differences in perioperative outcome, mortality and length of PCU and hospital stay were observed.Conclusion: 3 mL/kg of 3% HS result in similar brain relaxation scores as 5 mL/kg in patients undergoing craniotomy for supratentorial brain tumour. This study reveals that both high and low doses of 3% HS may be less effective on intraoperative brain relaxation in patients with midline shift.


Assuntos
Craniotomia/métodos , Solução Salina Hipertônica/uso terapêutico , Neoplasias Supratentoriais/cirurgia , Encéfalo/efeitos dos fármacos , Encéfalo/cirurgia , Edema Encefálico/cirurgia , Diuréticos Osmóticos/uso terapêutico , Método Duplo-Cego , Procedimentos Cirúrgicos Eletivos , Feminino , Hemodinâmica/efeitos dos fármacos , Humanos , Masculino , Manitol/farmacologia , Pessoa de Meia-Idade , Complicações Pós-Operatórias/cirurgia , Estudos Prospectivos , Neoplasias Supratentoriais/fisiopatologia
18.
Andrologia ; 49(3)2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27375281

RESUMO

This work examines the effectiveness of a TCG (Tris, citric acid, glucose, 6% egg yolk and 5% glycerol) and a TEST (TES, Tris, glucose, 6% egg yolk and 5% glycerol) sperm extender in the freezing of mouflon spermatozoa at slow cooling rates, using different pre-freezing equilibration times (2-3 hr). It also examines the tolerance of mouflon spermatozoa to different concentrations of cryoprotectants (5, 10, 20% glycerol; 5%, 10%, 20% dimethyl sulfoxide; 6% polyvinylpyrrolidone) and/or sucrose (100, 300, 500 mm). The highest quality (p < .01) thawed spermatozoa were obtained when using the TEST extender and an equilibration time of 3 hr. Sperm motility and membrane integrity were strongly reduced when using rapid freezing rates (60-85°C min-1 ), independent of the concentration of cryoprotectants. The lowest sucrose concentration (100 mm) provided the highest (p < .05) percentage of motile spermatozoa and live spermatozoa with an intact acrosome. Vitrified-warmed sperm variables were at their best when the spermatozoa was diluted in TCG-6% egg yolk + 100 mm sucrose and warmed at 60°C. Slow warming at 37°C strongly reduced (p < .05) sperm motility and viability. However, sperm vitrification returned lower fertility, sperm motility and sperm viability values than conventional sperm freezing.


Assuntos
Criopreservação/veterinária , Crioprotetores/farmacologia , Preservação do Sêmen/veterinária , Carneiro Doméstico , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos , Vitrificação , Animais , Sobrevivência Celular/efeitos dos fármacos , Ácido Cítrico/farmacologia , Criopreservação/métodos , Congelamento , Glucose/farmacologia , Glicerol/farmacologia , Masculino , Propano/análogos & derivados , Propano/farmacologia , Sacarose/farmacologia , Ácidos Sulfônicos/farmacologia , Fatores de Tempo , Trometamina/farmacologia
19.
Rev Med Chil ; 145(9): 1122-1128, 2017 Sep.
Artigo em Espanhol | MEDLINE | ID: mdl-29424398

RESUMO

BACKGROUND: Moral competence (MC) in physicians is fundamental, given the increasing complexity of medicine. The "Moral Competence Test" (MCT © Lind) evaluates this feature and its indicator is the C Index (CI). AIM: To explore moral competence and its associated factors among physicians working in Chile. MATERIAL AND METHODS: The MCT was answered by 236 physicians from two medical centers who voluntarily participated in the study. Besides the test, participants completed an encrypted form giving information about gender, years in practice and post-graduate studies. RESULTS: The average CI value of the participants was 20,9. Post-graduate studies had a significant positive influence on CI. There was a significant decrease in CI, between 16 and 20 years of professional exercise. Gender and the area of post-graduate studies did not have a significant influence. CONCLUSIONS: The studied physicians showed a wide range of CI which was positively affected by the postgraduate studies performed. The years of professional practice had a negative influence. Expanding training opportunities during professional practice could have a positive effect on CM as measured by CI.


Assuntos
Corpo Clínico Hospitalar/ética , Desenvolvimento Moral , Competência Profissional/estatística & dados numéricos , Julgamento Moral Retrospectivo , Análise de Variância , Chile , Estudos Transversais , Educação Médica , Feminino , Humanos , Masculino , Prática Profissional/ética , Valores de Referência , Distribuição por Sexo , Fatores Sexuais , Inquéritos e Questionários , Fatores de Tempo
20.
Andrologia ; 48(4): 475-80, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26289632

RESUMO

The use of condoms could provide a means of collecting high-quality spermatozoa from different species under physiological ejaculation conditions. However, certain condom materials may affect sperm functionality. This study examined the spermiotoxicity of different commercial condom materials towards ram and goat spermatozoa. Sperm samples were diluted in Tyrode's medium and placed in contact with a piece of condom material (polyurethane, polyisoprene or latex) and incubated for 30 or 90 min. Contact time in the polyisoprene and latex treatments affected some sperm variables; no such effects were seen, however, in the polyurethane treatments. For ram spermatozoa in contact with polyisoprene, the percentage of dead spermatozoa with a damaged acrosome increased at 90 min, while for spermatozoa in contact with latex, the percentage of live spermatozoa with an intact acrosome decreased. For goat spermatozoa in contact with both polyisoprene and latex, the percentage of dead spermatozoa with a damaged acrosome increased at 90 min, while for spermatozoa in contact with polyisoprene, the percentage of live spermatozoa with an intact acrosome decreased. In conclusion, latex and polyisoprene contain components that affect sperm motility, plasma membrane integrity and acrosome function. Polyurethane does not seem to reduce the quality of semen.


Assuntos
Preservativos/efeitos adversos , Látex/toxicidade , Poliuretanos/toxicidade , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos , Acrossomo/efeitos dos fármacos , Animais , Criopreservação/instrumentação , Cabras , Hemiterpenos/toxicidade , Masculino , Modelos Animais , Sêmen/efeitos dos fármacos , Preservação do Sêmen/instrumentação , Ovinos
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa