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1.
Small ; : e2406229, 2024 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-39263781

RESUMEN

Highly vertically thermally conductive silicon rubber (SiR) composites are widely used as thermal interface materials (TIMs) for chip cooling. Herein, inspired by water transport and transpiration of Moso bamboo-forests extensively existing in south China, and guided by filler self-assembly simulation, bamboo-forest-like heat conduction networks, with bamboo-stems-like vertically aligned polydopamine-coated carbon fibers (VA-PCFs), and bamboo-leaves-like horizontally layered Al2O3(HL-Al2O3), are rationally designed and constructed. VA-PCF/HL-Al2O3/SiR composites demonstrated enhanced heat conduction properties, and their through-plane thermal conductivity and thermal diffusivity reached 6.47 W (mK)-1 and 3.98 mm2 s-1 at 12 vol% PCF and 4 vol% Al2O3 loadings, which are 32% and 38% higher than those of VA-PCF (12 vol%) /SiR composites, respectively. The heat conduction enhancement mechanisms of VA-PCF/HL-Al2O3 networks on their SiR composites are revealed by multiscale simulation: HL-Al2O3 bridges the separate VA-PCF heat flow channels, and transfers more heat to the matrix, thereby increasing the vertical heat flux in composites. Along with high volume resistivity, low compression modulus, and coefficient of thermal expansion, VA-PCF/HL-Al2O3/SiR composites demonstrate great application potential as TIMs, which is proven using multiphysics simulation. This work not only makes a meaningful attempt at simulation-driven biomimetic material structure design but also provides inspiration for the preparation of TIMs.

2.
Opt Lett ; 49(13): 3717-3720, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38950250

RESUMEN

In this paper, we proposed a 2 × 2 multiple-input multiple-output (MIMO) dual spiral octagonal prism liquid dielectric resonator antenna (DRA) with snake-shaped defective ground structure (DGS) for space multiplexing of orbital angular momentum (OAM). The DRA element adopts an inner and outer nested dual spiral structure filled with 0.035 g/ml of brine outside and a cylinder filled with distilled water inside. The proposed MIMO antenna can generate resonance at 1.78-3.02 GHz and 4.01-7.73 GHz (S11≤-10 dB). The isolation among ports is below -20 dB at 2.6 GHz and below -40 dB at 5.1 GHz, which can effectively isolate the l = ±1 and l = ±3 modes' OAM waves through the snake-shaped DGS. The proposed MIMO antenna improves spectral efficiency by OAM spatial multiplexing with l = ±1 and l = ±3 modes' OAM, which improves the data transmission efficiency. The proposed MIMO antenna provides a novel, to the best of our knowledge, solution for wireless communications to improve spectral efficiency.

3.
Sensors (Basel) ; 24(6)2024 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-38544041

RESUMEN

Infrared video target detection is a fundamental technology within infrared warning and tracking systems. In long-distance infrared remote sensing images, targets often manifest as circular spots or even single points. Due to the weak and similar characteristics of the target to the background noise, the intelligent detection of these targets is extremely complex. Existing deep learning-based methods are affected by the downsampling of image features by convolutional neural networks, causing the features of small targets to almost disappear. So, we propose a new infrared video weak-target detection network based on central point regression. We focus on suppressing the image background by fusing the different features between consecutive frames with the original image features to eliminate the background's influence. We also employ high-resolution feature preservation and incorporate a spatial-temporal attention module into the network to capture as many target features as possible and improve detection accuracy. Our method achieves superior results on the infrared image weak aircraft target detection dataset proposed by the National University of Defense Technology, as well as on the simulated dataset generated based on real-world observation. This demonstrates the efficiency of our approach for detecting weak point targets in infrared continuous images.

4.
Int J Mol Sci ; 25(19)2024 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-39409099

RESUMEN

The BTB gene superfamily is widely distributed among higher eukaryotes and plays a significant role in numerous biological processes. However, there is limited knowledge about the structure and function of BTB genes in the critically endangered species Alligator sinensis, which is endemic to China. A total of 170 BTB genes were identified from the A. sinensis genome, classified into 13 families, and unevenly distributed across 16 chromosomes. Analysis of gene duplication events yielded eight pairs of tandem duplication genes and six pairs of segmental duplication genes. Phylogenetics shows that the AsBTB genes are evolutionarily conserved. The cis-regulatory elements in the AsBTB family promoter region reveal their involvement in multiple biological processes. Protein interaction network analysis indicates that the protein interactions of the AsBTB genes are centered around CLU-3, mainly participating in the regulation of biological processes through the ubiquitination pathway. The expression profile and protein interaction network analysis of AsBTB genes during sex differentiation and early gonadal development indicate that AsBTB genes are widely expressed in this process and involves numerous genes and pathways for regulation. This study provides a basis for further investigation of the role of the BTB gene in sex differentiation and gonadal development in A. sinensis.


Asunto(s)
Caimanes y Cocodrilos , Familia de Multigenes , Filogenia , Procesos de Determinación del Sexo , Animales , Procesos de Determinación del Sexo/genética , Caimanes y Cocodrilos/genética , Caimanes y Cocodrilos/crecimiento & desarrollo , Gónadas/metabolismo , Gónadas/crecimiento & desarrollo , Regulación del Desarrollo de la Expresión Génica , Masculino , Duplicación de Gen , Femenino , Mapas de Interacción de Proteínas/genética , Perfilación de la Expresión Génica , Diferenciación Sexual/genética , Genoma , Evolución Molecular
5.
Reprod Fertil Dev ; 34(12): 819-832, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35577543

RESUMEN

Although oviductal sperm storage are essential steps in reproduction for female animals with internal fertilisation, no systematic study on the identification of genes involving sperm storage has been performed in crocodilian species. In the present research, the relationship between morphological variation related to sperm storage in the oviduct and gene expression patterns derived from RNA sequencing analyses between active period (AP), breeding period (BP), and hibernation period (HP) were investigated. The corresponding results indicated that sperm were observed not only in the ciliated cells within infundibulum and mucosal layer of uterus during BP, but also been detected in the spermatosperm storage tube (SST) in the anterior uterus at HP stage. The further transmission electron microscopy analysis indicated that the differences in the number and activity of the secretory cells likely to attributed to the seasonal variation of microenvironment related to the sperm storage. Based on the RNA-sequecing, 13147 DEGs related to the Peroxisome proliferator-activated receptors (PPARs) and FOXO signalling were identified, including these, the down-regulated ATG12 and BCL2L11 in the HP group may thus constitute an important point of convergence between autophagy and apoptosis involving the FOXO1 pathway. The genes involved in the PPARs pathway might modulate the immune response and thereby contribute to prolong the life span of stored spermatozoa in Alligator sinensis . The outcomes of this study provide fundamental insights into the mechanism of sperm storage in A. sinensis .


Asunto(s)
Caimanes y Cocodrilos , Oviductos , Caimanes y Cocodrilos/fisiología , Animales , China , Femenino , Expresión Génica , Masculino , Oviductos/fisiología , Receptores Activados del Proliferador del Peroxisoma/metabolismo , Estaciones del Año , Semen , Espermatozoides/fisiología
6.
J Microsc ; 283(2): 117-126, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33826151

RESUMEN

Through-focus scanning optical microscopy (TSOM) is an economical, non-contact and nondestructive method for rapid measurement of three-dimensional nanostructures. There are two methods using TSOM image to measure the dimensions of one sample, including the library-matching method and the machine-learning regression method. The first has the defects of small measurement range and strict environmental requirements; the other has the disadvantages of feature extraction method greatly influenced by human subjectivity and low measurement accuracy. To solve the problems above, a TSOM dimensional measurement method based on deep-learning classification model is proposed. TSOM images are used to train the ResNet50 and DenseNet121 classification model respectively in this paper, and the test images are used to test the model, the classification result of which is taken as the measurement value. The test results showed that with the number of training linewidths increasing, the mean square error (MSE) of the test images is 21.05 nm² for DenseNet121 model and 31.84 nm² for ResNet50 model, both far lower than machine-learning regression method, and the measurement accuracy is significantly improved. The feasibility of using deep-learning classification model, instead of machine-learning regression model, for dimensional measurement is verified, providing a theoretical basis for further improvement on the accuracy of dimensional measurement.


Asunto(s)
Aprendizaje Profundo , Humanos , Aprendizaje Automático , Microscopía , Fenómenos Ópticos
7.
Reprod Fertil Dev ; 32(8): 792-804, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32389180

RESUMEN

Kisspeptin1 (Kiss1), a product of the Kiss1 gene, plays an important role in the regulation of reproduction in vertebrates by activating the Kiss1 receptor (Kiss1R) and its coexpression with gonadotrophin-releasing hormone (GnRH) in GnRH neurons. The purpose of this study was to clone the Kiss1 and Kiss1R genes found in the brain of Alligator sinensis and to explore their relationship with reproduction. The full-length cDNA of Kiss1 is 816bp, the open reading frame (ORF) is 417bp and the gene encodes a 138-amino acid precursor protein. The full-length cDNA of Kiss1R is 2348bp, the ORF is 1086bp and the gene encodes a 361-amino acid protein. Quantitative polymerase chain reaction showed that, except for Kiss1R expression in the hypothalamus, the expression of Kiss1 and Kiss1Rduring the reproductive period of A. sinensis was higher than that in the hypothalamus, pituitary gland and ovary during the hibernation period. The changes in GnRH2 mRNA in the hypothalamus were similar to those of GnRH1 and peaked during the reproductive period. This study confirms the existence of Kiss1 and Kiss1R in A. sinensis and the findings strongly suggest that Kiss1 and Kiss1R may participate in the regulation of GnRH secretion in the hypothalamus of alligators during the reproductive period. Furthermore, this is the first report of the full-length cDNA sequences of Kiss1 and Kiss1R in reptiles.


Asunto(s)
Caimanes y Cocodrilos/genética , Hipotálamo/metabolismo , Kisspeptinas/genética , Ovario/metabolismo , Hipófisis/metabolismo , Receptores de Kisspeptina-1/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , China , Clonación Molecular , ADN Complementario/química , ADN Complementario/genética , Femenino , Expresión Génica , Hormona Liberadora de Gonadotropina/genética , Hormona Liberadora de Gonadotropina/metabolismo , Hipotálamo/química , Kisspeptinas/química , Ovario/química , Filogenia , Hipófisis/química , ARN Mensajero/análisis , Reproducción/fisiología , Alineación de Secuencia
8.
Asian-Australas J Anim Sci ; 33(1): 24-34, 2020 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-29879812

RESUMEN

OBJECTIVE: The effects of Pleurotus ostreatus on the feed utilization improvement of broad bean stalks (BBS), rape straw (RS), paddy straw (PS) and corn stalk (CS) was examined. METHODS: The four roughages were co-cultured with Pleurotus ostreatus. The chemical composition; enzyme activities of laccase, carboxymethylcellulase (CMCase) and xylanase; carbohydrate and protein fractions (based on CNCPS) were assessed at different days after inoculation (7, 14, 21, 28 d) and un-inoculated roughages (control, 0 d). The digestibility of nutrient compenentscomponents and the gas production of roughage with various incubation times were monitored at 0, 2, 4, 6, 9, 12, 24, 36, 48, 60 and 72 h using an in vitro ruminal fermentation method. RESULTS: A higher CMCase activity (0.1039 U/mL) and earlier time to peak (14 d) were detected in Pleurotus ostreatus cultured with CS (P < 0.05). Significantly, the incubation length-dependent responses of cumulative gas production were observed from 24 to 72 hours post fermentation (P < 0.05), and these incubation length-dependent effects on cumulative gas production of PS and CS were appeared earlier (24 h) for PS and CS than those (48 h) for BBS and RS (P < 0.05). The fast-degradable carbohydrate (CA) content for all four roughages significantly increased over time (P < 0.05). Nonetheless, increased degradation efficiency for CA treated with Pleurotus ostreatus was detected at both 21 and 28 days of incubation (P < 0.05). With the exception of PS (P < 0.05), there were no significant difference among the roughages (P > 0.05) in slowly-degradable carbohydrate (CB2) at different incubation times (P < 0.05). CONCLUSION: Assessment of the alterations in chemical composition, CNCPS system fractions, and the fermentation kinetics after biological pretreatment may yield valuable database for evaluating the biological pretreatment of Pleurotus ostreatus in ruminants feed.

9.
Reprod Domest Anim ; 54(1): 72-82, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30180283

RESUMEN

The nutritional alteration of amino acids (AAs) profile in physiological fluid was poorly characterized in livestock. After oestrus synchronization, 24 ewes were randomly assigned to two groups based on the nutrient requirement recommended for maintenance (M): the feed-supplemented group (S, 1.5 × M, N = 12) and feed-restricted group (R, 0.5 × M, N = 12) on days 6-12 of their oestrous cycle, which occurred shortly before ovulation. The concentration of 30 AAs in peripheral blood (PB) and follicular fluid (FF) was quantified to calculate the PB-to-FF concentration gap for each AA and determine its correlation with metabolites and hormones in PB and FF. Results showed that the feed restriction enlarged the oestrous cycle length, decreased the number of follicles 2.5-3.5 mm, increased the number of follicles >3.5 mm and augmented the volume of follicles >2.5 mm. Nineteen AAs from PB were significantly different between the groups. The phosphoethanolamine (PEtN) and ration of essential AAs to nonessential AAs (EAA/NEAA) in FF significantly (p < 0.05) increased and decreased in the R group, respectively. Most AAs, except aspartate (Asp) and carnosine (Car) in the R group and alanine (aAla) in both groups, were significantly lower within FF than those within PB. The correlation of AAs with FSH and progesterone (P4 ) was more significant than that of AAs with other endocrine milieu characteristics. In conclusion, our results revealed that the influence of short-term nutritional manipulation during luteal phase on folliculogenesis might not be due to the variation of intrafollicular AAs profile but rather attribute to the peripheral blood AAs profile alteration.


Asunto(s)
Aminoácidos/sangre , Cromatografía Líquida de Alta Presión/veterinaria , Dieta/veterinaria , Líquido Folicular/química , Animales , Cromatografía Líquida de Alta Presión/métodos , Etanolaminas/análisis , Femenino , Hormona Folículo Estimulante/sangre , Líquido Folicular/metabolismo , Fase Luteínica/sangre , Fase Luteínica/metabolismo , Folículo Ovárico/fisiología , Progesterona/sangre , Oveja Doméstica/sangre , Oveja Doméstica/metabolismo
10.
Reprod Fertil Dev ; 30(11): 1522-1531, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31039948

RESUMEN

The aims of the present study were to determine whether dietary supplementation with N-carbamylglutamate (NCG) and rumen-protected l-arginine (RP-Arg) to underfed Hu sheep would improve fetal thymus development and immune function. From Day 35 to Day 110 of gestation, 32 Hu ewes carrying twin fetuses were randomly allocated to one of four groups (n=8 per group): 100% National Research Council (NRC)-recommended nutrient requirements (CON), 50% NRC recommendations (RES), 50% NRC recommendations supplemented with 20gday-1 RP-Arg (RES+ARG), and 50% NRC recommendations supplemented with 5gday-1 NCG (RES+NCG). Medullary thickness was increased (P<0.05) in RES compared with CON ewes, but was reduced (P<0.05) in both RES+ARG and RES+NCG ewes compared with RES ewes. There were no differences in superoxide dismutase and glutathione peroxidase activity or malondialdehyde levels in the RES+ARG and RES+NCG groups compared with the CON group (P>0.05). Concentrations of IgA, interleukin (IL)-1ß and IL-10 in fetal umbilical cord blood were reduced (P<0.05) in RES compared with CON ewes, but were increased (P<0.05) in both RES+ARG and RES+NCG ewes. Expression of Bax, Fas and p53 mRNA was increased (P<0.05) in RES compared with CON ewes, but were reduced (P>0.05) in both RES+ARG and RES+NCG ewes. These results indicate that dietary supplementation with NCG and RP-Arg could help alleviate the negative effects of intrauterine growth restriction on fetal thymus development and immune function.


Asunto(s)
Arginina/administración & dosificación , Desarrollo Fetal/efectos de los fármacos , Retardo del Crecimiento Fetal/inmunología , Glutamatos/administración & dosificación , Sistema Inmunológico/efectos de los fármacos , Timo/embriología , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Dieta/veterinaria , Suplementos Dietéticos , Femenino , Fenómenos Fisiologicos Nutricionales Maternos , Embarazo , Ovinos , Timo/efectos de los fármacos
11.
Appl Opt ; 57(7): 1650-1656, 2018 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-29522014

RESUMEN

Wavefront sensorless (WFSless) adaptive optics (AO) systems have been widely studied in recent years. To reach optimum results, such systems require an efficient correction method. This paper presents a fast wavefront correction approach for a WFSless AO system mainly based on the linear phase diversity (PD) technique. The fast closed-loop control algorithm is set up based on the linear relationship between the drive voltage of the deformable mirror (DM) and the far-field images of the system, which is obtained through the linear PD algorithm combined with the influence function of the DM. A large number of phase screens under different turbulence strengths are simulated to test the performance of the proposed method. The numerical simulation results show that the method has fast convergence rate and strong correction ability, a few correction times can achieve good correction results, and can effectively improve the imaging quality of the system while needing fewer measurements of CCD data.

12.
Reproduction ; 154(2): 111-122, 2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-28624767

RESUMEN

During goat follicular development, abnormal expression of nuclear respiratory factor 1 (NRF1) in granulosa cells may drive follicular atresia with unknown regulatory mechanisms. In this study, we investigated the effects of NRF1 on steroidogenesis and cell apoptosis by overexpressing or silencing it in goat luteinized granulosa cells (LGCs). Results showed that knockdown of NRF1 expression significantly inhibited the expression of STAR and CYP19A1, which are involved in sex steroid hormones synthesis, and led to lower estrogen levels. Knockdown of NRF1 resulted in an increased percentage of apoptosis, probably due to the release of cytochrome c from mitochondria, accompanied by upregulating mRNA and protein levels of apoptosis-related markers BAX, caspase 3 and caspase 9. These data indicate that NRF1 might be related with steroidogenesis and cell apoptosis. Furthermore, NRF1 silence reduced mitochondrial transcription factor A (TFAM) transcription activity, mtDNA copy number and ATP level. Simultaneously, knockdown of NRF1 suppressed the transcription and translation levels of SOD, GPx and CAT, decreased glutathione level and increased 8-OHdG level. However, the overexpression of NRF1 in LGCs or gain of TFAM in NRF1 silenced LGCs increased the expression of genes involved in mitochondrial function and biogenesis, and elevated the antioxidant stress system and steroids synthesis. Taken together, aberrant expression of NRF1 could induce mitochondrial dysfunction and disturb the cellular redox balance, which lead to disturbance of steroid hormone synthesis, and trigger LGC apoptosis through the mitochondria-dependent pathway. These findings will be helpful for understanding the role of NRF1 in goat ovarian follicular development and atresia.


Asunto(s)
Apoptosis , Estradiol/biosíntesis , Células Lúteas/metabolismo , Factor Nuclear 1 de Respiración/metabolismo , Progesterona/biosíntesis , Animales , Proteínas Reguladoras de la Apoptosis/genética , Proteínas Reguladoras de la Apoptosis/metabolismo , Aromatasa/genética , Aromatasa/metabolismo , Supervivencia Celular , Células Cultivadas , Ciclo Estral/genética , Ciclo Estral/metabolismo , Femenino , Regulación del Desarrollo de la Expresión Génica , Regulación Enzimológica de la Expresión Génica , Cabras , Células Lúteas/patología , Mitocondrias/metabolismo , Mitocondrias/patología , Factor Nuclear 1 de Respiración/genética , Oxidación-Reducción , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Interferencia de ARN , Transducción de Señal , Transfección
13.
J Bioenerg Biomembr ; 48(5): 493-507, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27896503

RESUMEN

During goat follicular development, abnormal expression of peroxisome proliferator- activated receptor gamma coactivator-1 alpha (PGC-1α) in granulosa cells (GCs) may contribute to follicular atresia with unknown regulatory mechanisms. In this study, we investigate the effect of ectopic expression or interference of PGC-1α on cell apoptosis of goat first passage granulosa cells (FGCs) in vitro. The results indicate that PGC-1α silencing by short hairpin RNA (shRNA) in goat FGCs significantly reduced mitochondrial DNA (mtDNA) copy number (P < 0.05), changed mitochondria ultrastructure, and induced cell apoptosis (P < 0.05). The transcription and translation levels of the apoptosis-related genes BCL-2-associated X protein (BAX), caspase 3, and caspase 9 were significantly up-regulated (P < 0.05, respectively). Moreover, the ratio of BAX/B-cell lymphoma 2 (BCL-2) was reduced (P < 0.05), and the release of cytochrome c (cyt c) and lactate dehydrogenase (LDH) was significantly enhanced (P < 0.05, respectively) in PGC-1α interference goat FGCs. Furthermore, the expression of anti-oxidative related genes superoxide dismutase 2 (SOD2), glutathione peroxidase (GPx) and catalase (CAT) was down-regulated (P < 0.05, respectively) and the activity of glutathione/glutathione disulfide (GSH/GSSG) was inhibited (P < 0.05). While enforced expression of PGC-1α increased the levels of genes involved in the regulation of mitochondrial function and biogenesis, and enhanced the anti-oxidative and anti-apoptosis capacity. Taken together, our results reveal that lack of PGC-1α may lead to mitochondrial dysfunction and disrupt the cellular redox balance, thus resulting in goat GCs apoptosis through the mitochondria-dependent apoptotic pathway.


Asunto(s)
Apoptosis/efectos de los fármacos , Células de la Granulosa/patología , Luteinización , Mitocondrias/patología , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/genética , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/farmacología , Animales , Células Cultivadas , Femenino , Expresión Génica , Silenciador del Gen , Cabras , Mitocondrias/genética , Mitocondrias/ultraestructura , Oxidación-Reducción
14.
Reproduction ; 151(6): 623-35, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-26980807

RESUMEN

The objectives of this study were to determine how dietary supplementation of N-carbamylglutamate (NCG) and rumen-protected L-arginine (RP-Arg) in nutrient-restricted pregnant Hu sheep would affect (1) maternal endocrine status; (2) maternal, fetal, and placental antioxidation capability; and (3) placental development. From day 35 to day 110 of gestation, 32 Hu ewes carrying twin fetuses were allocated randomly into four groups: 100% of NRC-recommended nutrient requirements, 50% of NRC recommendations, 50% of NRC recommendations supplemented with 20g/day RP-Arg, and 50% of NRC recommendations supplemented with 5g/day NCG product. The results showed that in maternal and fetal plasma and placentomes, the activities of total antioxidant capacity and superoxide dismutase were increased (P<0.05); however, the activity of glutathione peroxidase and the concentration of maleic dialdehyde were decreased (P<0.05) in both NCG- and RP-Arg-treated underfed ewes. The mRNA expression of vascular endothelial growth factor and Fms-like tyrosine kinase 1 was increased (P<0.05) in 50% NRC ewes than in 100% NRC ewes, and had no effect (P>0.05) in both NCG- and RP-Arg-treated underfed ewes. A supplement of RP-Arg and NCG reduced (P<0.05) the concentrations of progesterone, cortisol, and estradiol-17ß; had no effect on T4/T3; and improved (P<0.05) the concentrations of leptin, insulin-like growth factor 1, tri-iodothyronine (T3), and thyroxine (T4) in serum from underfed ewes. These results indicate that dietary supplementation of NCG and RP-Arg in underfed ewes could influence maternal endocrine status, improve the maternal-fetal-placental antioxidation capability, and promote fetal and placental development during early-to-late gestation.


Asunto(s)
Arginina/farmacología , Desarrollo Fetal/efectos de los fármacos , Retardo del Crecimiento Fetal/veterinaria , Glutamatos/farmacología , Fenómenos Fisiologicos Nutricionales Maternos/efectos de los fármacos , Placenta/citología , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Arginina/administración & dosificación , Femenino , Retardo del Crecimiento Fetal/prevención & control , Glutamatos/administración & dosificación , Placenta/efectos de los fármacos , Placenta/fisiología , Embarazo , Ovinos
15.
Appl Opt ; 54(26): 7917-24, 2015 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-26368964

RESUMEN

The conventional Broyden-Fletcher-Goldfarb-Shanno (BFGS) method used to solve the cost function of a phase diversity (PD) algorithm converges to a global optimum only when the cost function is convex. We present a modified BFGS method, which has fine global convergences for both convex and nonconvex functions, guarantees that the solutions will converge to the global minimum, corresponding to the actual wavefront coefficients, and apply it to minimize the PD cost function to co-phase the segmented active optics system and recover the unknown object under different noise levels. The noise amplification effect on the accuracy of the algorithm is removed by our proposed estimated strategy of the regularization parameter for the PD problem. The vast contrast results demonstrate that the modified method has a much higher accuracy than the conventional BFGS method for the nonconvex condition even under a considerably high noise level.

16.
ACS Nano ; 17(19): 19323-19337, 2023 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-37769163

RESUMEN

Insulating thermally conductive polymer composites are in great demand in integrated-circuit packages, for efficient heat dissipation and to alleviative short-circuit risk. Herein, the continuous oriented hexagonal boron nitride (h-BN) frameworks (o-BN@SiC) were prepared via self-assembly and in situ chemical vapor infiltration (CVI) interface welding. The insulating o-BN@SiC/epoxy (o-BN@SiC/EP) composites exhibited enhanced thermal conductivity benefited from the CVI-SiC-welded BN-BN interface. Further, multiscale simulation, combining first-principles calculation, Monte Carlo simulation, and finite-element simulation, was performed to quantitatively reveal the effect of the welded BN-BN interface on the heat transfer of o-BN@SiC/EP composites. Phonon transmission in solders and phonon-phonon coupling of filler-solder interfaces enhanced the interfacial heat transfer between adjacent h-BN microplatelets, and the interfacial thermal resistance of the dominant BN-BN interface was decreased to only 3.83 nK·m2/W from 400 nK·m2/W, plunging by over 99%. This highly weakened interfacial thermal resistance greatly improved the heat transfer along thermal pathways and resulted in a 26% thermal conductivity enhancement of o-BN@SiC/EP composites, compared with physically contacted oriented h-BN/EP composites, at 15 vol % h-BN. This systematic multiscale simulation broke through the barrier of revealing the heat transfer mechanism of polymer composites from the nanoscale to the macroscale, which provided rational cognition about the effect of the interfacial thermal resistance between fillers on the thermal conductivity of polymer composites.

17.
BMC Zool ; 8(1): 8, 2023 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-37403129

RESUMEN

BACKGROUND: The precise mechanisms of hormone action responsible for the full course of events modulating folliculogenesis in crocodilian have not been determined, although histological features have been identified. RESULTS: The Alligator sinensis ovarian morphological characteristics observed at 1, 15, 30, 60, 90, and 300 days post hatching(dph) revealed that the dynamic changes in germ cells varied in different meiotic and developmental stages, confirming that the processes of folliculogenesis were protracted and asynchronous. The presence of endogenous follicle-stimulating hormone(FSH) mRNA and protein expression within the cerebrum at 1 dph, in parallel with the increase in germ cells within the germ cell nests(Nest) from 1 dph to 15 dph, suggested that endocrine regulation of the pituitary-gonad axis is an early event in oogonia division. Furthermore, the endogenous expression of FSH showed a trend of negative feedback augmentation accompanied by the exhaustion of maternal yolk E2 observed at 15 dph. Such significant elevation of endogenous FSH levels was observed to be related to pivotal events in the transition from mitosis to meiosis, as reflected by the proportion of oogonia during premeiosis interphase, with endogenous FSH levels reaching a peak at the earliest time step of 1 dph. In addition, the simultaneous upregulation of premeiotic marker STRA8 mRNA expression and the increase in endogenous FSH further verified the above speculation. The strongly FSHr-positive label in the oocytes within Pre-previtellogenic follicles was synchronized with the significant elevation of ovarian cAMP detected at 300 dph, which suggested that diplotene arrest maintenance during early vitellogenesis might be FSH dependent. In addition, preferential selection in asynchronous meiotic initiation has been supposed to act on somatic supportive cells and not directly on germ cells via regulation of FSH that in turn affects downstream estrogen levels. This suggestion was verified by the reciprocal stimulating effect of FSH and E2 on the accelerated meiotic marker SYCP3 and by the inhibited cell apoptosis demonstrated in ovarian cell culture in vitro. CONCLUSION: The corresponding results contribute an expansion of the understanding of physiological processes and shed some light on the specific factors responsible for gonadotropin function in the early folliculogenesis of crocodilians.

18.
Anim Reprod Sci ; 255: 107295, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37422950

RESUMEN

The critical role of the G protein-coupled receptor 1 (GPER1), a member of the seven-transmembrane G protein-coupled receptor family, in the functional regulation of oocytes accumulated abundant theories in the early research on model animals. However, the full-length cDNA encoding GPER1 and its role in the folliculogenesis has not been illustrated in crocodilians. 0.5, 3, and 12 months old Alligator sinensis cDNA samples were used to clone the full-length cDNA encoding GPER1. Immunolocalization and quantitative analysis were performed using Immunofluorescence technique, RT-PCR and Western blot. Simultaneously, studies on GPER1's promoter deletion and cis-acting transcriptional regulation mechanism were conducted. Immunolocalization staining for the germline marker DDX4 and GPER1 demonstrated that DDX4-positive oocytes were clustered tightly together within the nests, whereas scarcely any detectable GPER1 was present in the oocytes nest in Stage I. After that, occasionally GPER1-positive immunosignal was observed in oocytes and somatic cells additional with the primordial follicles, and it was mainly located at the granulosa cells or thecal cells within the early PFs in the Stage III. The single mutation of the putative SP1 motif, double mutating of Ets/SP1 and SP1/CRE binding sites all depressed promoter activities. This result will help to investigate the role of GPER1 in the early folliculogenesis of A. sinensis.


Asunto(s)
Caimanes y Cocodrilos , Femenino , Animales , Caimanes y Cocodrilos/genética , ADN Complementario/metabolismo , Ovario/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Proteínas de Unión al GTP/metabolismo
19.
Life (Basel) ; 12(11)2022 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-36362939

RESUMEN

Significant advances have been made in the morphological observations of the dorsal gland (DG), an oval organ/tissue which lies on both sides of the dorsal midline of the crocodilian. In the current study, RNA sequencing (RNA-seq) was used to identify the changing patterns of Alligator sinesis DGs at different timepoints from the 31st embryonic day (E31) to the newly hatched 1st day (NH1). A comprehensive transcriptional changes of differentially expression gene (DEGs) involved in the melanogenesis, cholesterol metabolism, and cell apoptosis pathways suggested that the DG might serves as a functional secretory gland in formation, transport and deposition of pigment, and lipids secretion via lysosomal exocytosis. Furthermore, the remarkable immunohistochemical staining of proliferating cell nuclear antigen (PCNA) and B-cell lymphoma 2 (Bcl-2)-positive signals in the basilar cells, in parallel with the immuno-reactive TdT-mediated dUTP nick-End labeling(TUNEL) within suprabasal cells, provided direct molecular evidence supporting for the speculation that DG serves as a holocrine secretion mode. Finally, subsequent phylogenetic and immunohistochemical analysis for the PITX2, the identified DEGs in the RNA-seq, was helpful to further elucidate the transcriptional regulatory mechanism of candidate genes. In conclusion, the current results are of considerable importance in enriching our understanding of the intrinsic relationship between the skin derivatives and lifestyles of newborn Alligator sinesis.

20.
Reproduction ; 142(5): 699-710, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21893609

RESUMEN

This study investigated the effects of short-term food restriction or supplementation on folliculogenesis and plasma and intrafollicular metabolite and hormone concentrations. Ewes were randomly assigned to three groups: the control group received a maintenance diet (M) while the supplemented group and restricted group received 1.5×M and 0.5×M respectively on days 6-12 of their estrous cycle. Estrus was synchronized by intravaginal progestogen sponges for 12 days. On days 7-12, blood samples were taken. After slaughter, the ovarian follicles were classified and the follicular fluid was collected. Compared with restriction, supplementation shortened the estrous cycle length, decreased the number of follicles 2.5-3.5 mm and follicular fluid estradiol (E2) concentration, increased the number of follicles>3.5 mm and plasma glucose, insulin and glucagon concentrations, and augmented the volume of follicles>2.5 mm. Restricted ewes had higher intrafollicular insulin concentration, but it was similar to that of supplemented ewes. Compared with follicles≤2.5 mm, the intrafollicular glucose and E2 concentrations were increased and the testosterone, insulin, and glucagon concentrations and lactate dehydrogenase (LDH) activity were decreased in follicles>2.5 mm. Only in restricted ewes were intrafollicular LDH and testosterone concentrations in follicles≤2.5 mm not different from those in follicles≤2.5 mm. In conclusion, the mechanism by which short-term dietary restriction inhibits folliculogenesis may involve responses to intrafollicular increased E2, testosterone, and LDH levels in late-stage follicles. This may not be due to the variation of intrafollicular insulin level but rather due to decreased circulating levels of glucose, insulin, and glucagon.


Asunto(s)
Ingestión de Alimentos/fisiología , Líquido Folicular/química , Glucosa/análisis , Hormonas/análisis , L-Lactato Deshidrogenasa/análisis , Folículo Ovárico/fisiología , Ovinos/fisiología , Alimentación Animal , Animales , Análisis Químico de la Sangre , Glucemia/análisis , Glucemia/metabolismo , Restricción Calórica/veterinaria , Suplementos Dietéticos , Femenino , Líquido Folicular/metabolismo , Glucosa/metabolismo , Hormonas/sangre , Hormonas/metabolismo , L-Lactato Deshidrogenasa/sangre , L-Lactato Deshidrogenasa/metabolismo , Fase Luteínica/sangre , Fase Luteínica/metabolismo , Fase Luteínica/fisiología , Concentración Osmolar , Ovinos/sangre , Ovinos/metabolismo , Factores de Tiempo
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