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1.
J Anim Sci ; 1022024 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-38581217

RESUMEN

Pelleted total mixed ration (P-TMR) feeding, which has become a common practice in providing nutrition for fattening sheep, requires careful consideration of the balance between forage neutral detergent fiber (FNDF) and rumen degradable starch (RDS) to maintain proper rumen functions. The present study aimed to investigate the effects of the dietary FNDF/RDS ratio (FRR) on chewing activity, ruminal fermentation, ruminal microbes, and nutrient digestibility in Hu sheep fed a P-TMR diet. This study utilized eight ruminally cannulated male Hu sheep, following a 4 × 4 Latin square design with 31 d each period. Diets consisted of four FRR levels: 1.0 (high FNDF/RDS ratio, HFRR), 0.8 (middle high FNDF/RDS ratio, MHFRR), 0.6 (middle low FNDF/RDS ratio, MLFRR), and 0.4 (low FNDF/RDS ratio, LFRR). Reducing the dietary FRR levels resulted in a linear decrease in ruminal minimum pH and mean pH, while linearly increasing the duration and area of pH below 5.8 and 5.6, as well as the acidosis index. Sheep in the HFRR and MHFRR groups did not experience subacute ruminal acidosis (SARA), whereas sheep in another two groups did. The concentration of total volatile fatty acid and the molar ratios of propionate and valerate, as well as the concentrate of lactate in the rumen linearly increased with reducing dietary FRR, while the molar ratio of acetate and acetate to propionate ratio linearly decreased. The degradability of NDF and ADF for alfalfa hay has a quadratic response with reducing the dietary FRR. The apparent digestibility of dry matter, organic matter, neutral detergent fiber, and acid detergent fiber linearly decreased when the dietary FRR was reduced. In addition, reducing the dietary FRR caused a linear decrease in OTUs, Chao1, and Ace index of ruminal microflora. Reducing FRR in the diet increased the percentage of reads assigned as Firmicutes, but it decreased the percentage of reads assigned as Bacteroidetes in the rumen. At genus level, the percentage of reads assigned as Prevotella, Ruminococcus, Succinivibrio, and Butyrivibrio linearly decreased when the dietary FRR was reduced. The results of this study demonstrate that the dietary FRR of 0.8 is crucial in preventing the onset of SARA and promotes an enhanced richness of ruminal microbes and also improves fiber digestibility, which is a recommended dietary FRR reference when formulating P-TMR diets for sheep.


Forage neutral detergent fiber (FNDF) and rumen degradable starch (RDS) are key components of carbohydrates in the diet for ruminants, which would reflect saliva secretion and the acid production potential of feed. However, appropriate FNDF to RDS ratios (FRR) applicable to ruminants under the condition of pelleted total mixed ration (P-TMR) feeding have not been reported. In this study, we investigated the effects of the dietary FRR on chewing activity, ruminal fermentation, ruminal microbial communities, and nutrient digestibility of Hu sheep under P-TMR feeding. The results indicate that reducing dietary FRR levels would induce acidosis in sheep, which negatively affected fiber utilization and ruminal bacterial communities. The FRR of 0.8 was a recommended dietary FRR when formulating a P-TMR diet for fattening sheep, as indicated by decreased ruminal acidosis risk and increased richness of ruminal microbes in the rumen as well as nutrient digestibility.


Asunto(s)
Acidosis , Enfermedades de las Ovejas , Masculino , Femenino , Animales , Ovinos , Leche/metabolismo , Masticación/fisiología , Almidón/metabolismo , Lactancia/fisiología , Detergentes/metabolismo , Ensilaje/análisis , Propionatos/metabolismo , Fermentación , Rumen/metabolismo , Fibras de la Dieta/metabolismo , Carbohidratos de la Dieta/metabolismo , Dieta/veterinaria , Nutrientes , Acetatos/metabolismo , Acidosis/veterinaria , Digestión/fisiología
2.
Genes (Basel) ; 13(12)2022 12 17.
Artículo en Inglés | MEDLINE | ID: mdl-36553664

RESUMEN

The Tibetan pig is an endemic economic animal in the plateau region of China, and has a unique adaptation mechanism to the plateau hypoxic environment. Research into microRNAs (miRNAs) involved in the mechanism underlying hypoxia adaptation of Tibetan pig is very limited. Therefore, we isolated alveolar type II epithelial (ATII) cells from the lungs of the Tibetan pig, cultured them in normoxia/hypoxia (21% O2; 2% O2) for 48 h, and performed high-throughput sequencing analysis. We identified a hypoxic stress-related ssc-miR-141 and predicted its target genes. The target genes of ssc-miR-141 were mainly enriched in mitogen-activated protein kinase (MAPK), autophagy-animal, and Ras signaling pathways. Further, we confirmed that PDCD4 may serve as the target gene of ssc-miR-141. Real-time quantitative polymerase chain reaction (RT-qPCR) analysis was performed to confirm the expression levels of ssc-miR-141 and PDCD4, and a dual-luciferase gene reporter system was used to verify the targeted linkage of ssc-miR-141 to PDCD4. The results showed that the expression level of ssc-miR-141 in the hypoxia group was higher than that in the normoxia group, while the expression level of PDCD4 tended to show the opposite trend and significantly decreased under hypoxia. These findings suggest that ssc-miR-141 is associated with hypoxia adaptation and provide a new insight into the role of miRNAs from ATII cells of Tibetan pig in hypoxia adaptation.


Asunto(s)
MicroARNs , Porcinos/genética , Animales , Tibet , MicroARNs/genética , MicroARNs/metabolismo , Proteínas Reguladoras de la Apoptosis/genética , Hipoxia/genética , Células Epiteliales/metabolismo
3.
Molecules ; 27(17)2022 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-36080330

RESUMEN

Calcium-enriched compounds have great potential in the treatment of heavy-metal contaminated wastewater. Preparing stable basic calcium carbonate (BCC), which is a calcium-enriched compound, and applying it in practice is a great challenge. This work investigated the formation process of hierarchical hydroxyapatite (HAP)/BCC nanocomposites and their adsorption behaviors regarding lead ions (Pb2+). The morphology of the HAP/BCC nanocomposite was controlled by the addition of monododecyl phosphate (MDP). The carnation-like HAP/BCC nanocomposite was achieved with the addition of 30 g of MDP. The carnation-like HAP/BCC nanocomposite had a high Pb2+ adsorption capacity of 860 mg g-1. The pseudo-second-order and Freundlich model simulation results indicated that the adsorptions of Pb2+ on the nanocomposites belonged to the chemisorption and multilayer adsorption processes. The main effective adsorption components for the nanocomposites were calcium-enriched HAP and BCC. Through the Ca2+ ions exchanging with Pb2+, the HAP and BCC phases were converted to hydroxyl-pyromorphite (Pb-HAP) and hydrocerussite (Pb3(CO3)2(OH)2), respectively. The carnation-like HAP/BCC nanocomposite has great potential in the treatment of heavy metal ions. This facile method provides a new method for preparing a stable HAP/BCC nanocomposite and applying it in practice.


Asunto(s)
Dianthus , Metales Pesados , Nanocompuestos , Contaminantes Químicos del Agua , Adsorción , Calcio , Carbonato de Calcio , Durapatita , Iones , Cinética , Plomo , Fenómenos Magnéticos , Agua , Contaminantes Químicos del Agua/análisis
4.
Phys Chem Chem Phys ; 24(33): 19853-19864, 2022 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-35960148

RESUMEN

The structure and electronic properties of the MoSe2/PtS2 van der Waals heterostructure and their dependence on the interlayer coupling, biaxial strain and external electric field are systematically investigated by using first-principles calculations. Herein, six stacking patterns are taken into consideration. The most energy favorable one is the AC stacking pattern, which is an indirect band gap semiconductor with type-I band alignment. The interlayer coupling, biaxial strain and external electric field can not only tune the band alignment of the MoSe2/PtS2 heterostructure from type-I band alignment to the type-II one, but also effectively modulate the band gap, ranging from 0 eV to 0.805 eV. These interesting properties induced by interlayer charge transfer, such as tunable band gaps and the characteristic of type-II band alignment, are beneficial for the application of the 2D MoSe2/PtS2 van der Waals heterostructure in future electronic and optoelectronic devices.

5.
Animals (Basel) ; 12(15)2022 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-35953930

RESUMEN

This study aimed to explore the effects of different levels of barley starch instead of corn starch on the rumen fermentation and microflora when feeding a corn-based diet to Hu sheep. Thirty-two male Hu sheep equipped with permanent rumen fistulas were selected and fed in individual metabolic cages. All sheep were randomly divided into four groups (eight sheep in each group) and fed with four diets containing a similar starch content, but from different starch sources, including 100% of starch derived from corn (CS), 33% of starch derived from barley + 67% of starch derived from corn (33 BS), 67% of starch derived from barley + 33% of starch derived from corn (67 BS) and 100% of starch derived from barley (100 BS). The experimental period included a 14 d adaptation period and a 2 d continuous data collection period. The results showed that the molar proportions of acetate, isobutyrate, butyrate and isovalerate and the ratio of acetate to propionate in the 67 BS and 100 BS groups decreased compared with the CS and 33 BS groups (p < 0.001), while the molar proportions of propionate and valerate increased (p < 0.001). The combination of 33% barley starch and 67% corn starch in the diet improved the production of TVFAs (p = 0.007). The OTUs and Shannon indexes of the CS and 33 BS groups were higher than the 67 BS and 100 BS groups (p < 0.001), and the Chao1 and Ace indexes were higher than the 100 BS group (p < 0.05). In addition, the 33 BS group had increased the relative abundances of Bacteroidetes, Prevotella and Ruminococcus and the abundances of Fibrobacter succinogenes, Ruminococcus flavefaciens, Streptococcus bovis, Selenomonas ruminantium and Prevotella brevis relative to the CS group (p < 0.05). These results indicate that the substitution of 33% of the CS with BS did not change the rumen fermentation pattern relative to the CS group, and increased the richness and diversity of the rumen microbes in Hu sheep compared with other two starch substitute groups.

6.
Nat Commun ; 11(1): 992, 2020 02 20.
Artículo en Inglés | MEDLINE | ID: mdl-32080182

RESUMEN

The Asian monsoon (AM) played an important role in the dynastic history of China, yet it remains unknown whether AM-mediated shifts in Chinese societies affect earth surface processes to the point of exceeding natural variability. Here, we present a dust storm intensity record dating back to the first unified dynasty of China (the Qin Dynasty, 221-207 B.C.E.). Marked increases in dust storm activity coincided with unified dynasties with large populations during strong AM periods. By contrast, reduced dust storm activity corresponded to decreased population sizes and periods of civil unrest, which was co-eval with a weakened AM. The strengthened AM may have facilitated the development of Chinese civilizations, destabilizing the topsoil and thereby increasing the dust storm frequency. Beginning at least 2000 years ago, human activities might have started to overtake natural climatic variability as the dominant controls of dust storm activity in eastern China.

7.
Trop Anim Health Prod ; 52(1): 115-121, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31273580

RESUMEN

Tropical and subtropical regions were quite short of high-quality protein forage. Ramie (Boehmeria nivea L. Gaud) leaves as crop by products, are rich in protein and widely cultivated in tropical and subtropical regions. Thence, the development and utilization of ramie is of great significance to animal production in these regions. But it contained high level of tannins and total phenols, which may produce potentially adverse effect. It is very essential to evaluate the safety of ramie leaves before they are used as feed supplements. To evaluate potential toxic level of ramie leaf, control group, low dose and high dose (0, 1, 2 g/kg·BW) groups of ramie leaf were conducted orally in Sprague-Dawley rats (SD rats). Body weight, hematology, and histopathology was assessed during 28 d of treatment and 14 d of recovery period. The results showed that there were no toxic symptoms appeared in the treated and control groups. There were a few individual indicators showed abnormal, but most indices of body weight, organ weight ratios and hematology were normal. And compared to control group, it showed no significant differences (P>0.05). Histopathological examination of the high dose group and control group showed that there was no lesions related to ramie administration. The pathological changes appeared in the liver, and lungs of rats in individual rat of both groups were common and spontaneous, and had no significant differences (P>0.05). These results suggest that under this experimental condition, up to 2 g/kg·BW intragastric administration of ramie leaf did not produce adverse effect to SD rats. These findings would provide available information for ramie leaf to utilize as a feed supplement, particularly in P.R. China.


Asunto(s)
Alimentación Animal/análisis , Boehmeria/química , Suplementos Dietéticos/análisis , Hojas de la Planta/química , Alimentación Animal/efectos adversos , Animales , China , Suplementos Dietéticos/efectos adversos , Femenino , Masculino , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley
8.
BMC Plant Biol ; 19(1): 205, 2019 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-31109303

RESUMEN

BACKGROUND: Fall dormancy and freezing tolerance characterized as two important phenotypic traits, have great effects on productivity and persistence of alfalfa (Medicago sativa L.). Despite the fact that one of the most limiting traits for alfalfa freezing tolerance in winter is fall dormancy, the interplay between fall dormancy and cold acclimation processes of alfalfa remains largely unknown. We compared the plant regrowth, winter survival, raffinose and amino acids accumulation, and genome-wide differentially expressed genes of fall-dormant cultivar with non-dormant cultivar under cold acclimation. RESULTS: Averaged over both years, the non-dormant alfalfa exhibited largely rapid regrowth compared with fall dormant alfalfa after last cutting in autumn, but the winter survival rate of fall dormant alfalfa was about 34-fold higher than that of non-dormant alfalfa. The accumulation of raffinose and amino acids were significantly increased in fall dormant alfalfa, whereas were decreased in non-dormant alfalfa under cold acclimation. Expressions of candidate genes encoding raffinose biosynthesis genes were highly up-regulated in fall dormant alfalfa, but down-regulated in non-dormant alfalfa under cold acclimation. In fall dormant alfalfa, there was a significantly down-regulated expression of candidate genes encoding the glutamine synthase, which is indirectly involved in the proline metabolism. A total of eight significantly differentially expressed transcription factors (TFs) related to CBF and ABRE-BFs were identified. The most up-regulated TFs in fall dormant alfalfa cultivar were ABF4 and DREB1C. CONCLUSIONS: Fall dormant alfalfa drastically increased raffinose and amino acids accumulation under cold acclimation. Raffinose-associated and amino acid-associated genes involved in metabolic pathways were more highly expressed in fall dormant alfalfa than non-dormant alfalfa under cold acclimation. This global survey of transcriptome profiles provides new insights into the interplay between fall dormancy and cold acclimation in alfalfa.


Asunto(s)
Regulación de la Expresión Génica de las Plantas/fisiología , Medicago sativa/fisiología , Latencia en las Plantas/genética , Proteínas de Plantas/genética , Transcriptoma/fisiología , Perfilación de la Expresión Génica , Longevidad , Medicago sativa/genética , Estaciones del Año
9.
Asian-Australas J Anim Sci ; 32(8): 1145-1152, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30744357

RESUMEN

OBJECTIVE: Mulberry (Morus alba L.) is a cultivated shrub grown widely in the sub-tropical and tropical areas. It has been shown that mulberry leaf contains high levels of protein while having polyphenols as phytonutrients. Therefore, it is important to conduct an experiment to assess potential toxic level from mulberry on behavior, blood hematological and coagulation parameter using Sprague-Dawley (SD) rats. METHODS: Both male and female SD rats were given an intragastric administration of respective treatments of mulberry leaf intakes (control, low and high levels). Parameters of feed intake, hematological and coagulation of blood parameters, as well as liveweight changes were taken during the 7 d of adaptation, 28 d of treatment exposure, and 14 d of recovery periods, respectively. All treatment data were statistically analyzed using analysis of variance of SPSS17.0 for Windows Statistical Software following the Randomized complete block design with sex as a block. RESULTS: Most of the parameters of the physical symptoms of the SD rats, were not significantly different (p>0.05) when compared with that of the control group. Those which remain unchanged in each dose group were, body weight (BW) gain, feed intake, the hematology and coagulation indexes. Although, there were a few individual indicators that were abnormal, but the overall physiological appearance of the rats were normal. CONCLUSION: Results under this experiment revealed that most hematological and coagulation parameters of the SD rats in both male and female were normal, although the weight gain of female rats in high-dose group was significantly reduced than those of the male rats. Under this study, the use of mulberry leaf up to 2 g/kg BW did not result in abnormal phenomenon in the SD rats. These findings would offer useful information for further in vivo feeding trials in animals to extensively use of mulberry leaf to improve animal production, particularly in P.R. China.

10.
Can J Microbiol ; 63(10): 811-821, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28742981

RESUMEN

Large quantities of carbon are stored in alpine grassland of the Tibetan Plateau, which is extremely sensitive to climate change. However, it remains unclear whether soil organic matter (SOM) in different layers responds to climate change analogously, and whether microbial communities play vital roles in SOM turnover of topsoil. In this study we measured and collected SOM turnover by the 14C method in alpine grassland to test climatic effects on SOM turnover in soil profiles. Edaphic properties and microbial communities in the northwestern Qinghai Lake were investigated to explore microbial influence on SOM turnover. SOM turnover in surface soil (0-10 cm) was more sensitive to precipitation than that in subsurface layers (10-40 cm). Precipitation also imposed stronger effects on the composition of microbial communities in the surface layer than that in deeper soil. At the 5-10 cm depth, the SOM turnover rate was positively associated with the bacteria/fungi biomass ratio and the relative abundance of Acidobacteria, both of which are related to precipitation. Partial correlation analysis suggested that increased precipitation could accelerate the SOM turnover rate in topsoil by structuring soil microbial communities. Conversely, carbon stored in deep soil would be barely affected by climate change. Our results provide valuable insights into the dynamics and storage of SOM in alpine grasslands under future climate scenarios.


Asunto(s)
Bacterias/crecimiento & desarrollo , Hongos/crecimiento & desarrollo , Microbiota , Microbiología del Suelo , Acidobacteria/crecimiento & desarrollo , Biomasa , Carbono/análisis , Cambio Climático , Pradera , Lluvia , Suelo , Tibet
11.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 33(6): 871-874, 2016 Dec 10.
Artículo en Chino | MEDLINE | ID: mdl-27984625

RESUMEN

Bardet-Biedl syndrome (BBS) is a rare autosomal recessive disease characterized by retinopathy, obesity, and polydactyly. So far 21 candidate genes have been discovered, and mutations of such genes can all cause the BBS phenotype. As one of the main features of the disease, the obesity in BBS has been associated with leptin resistance and abnormal adipogenesis. However, its molecular etiology is not yet completely clear. Here the molecular mechanism of BBS-associated obesity is reviewed.


Asunto(s)
Síndrome de Bardet-Biedl/genética , Obesidad/genética , Humanos , Fenotipo , Polidactilia/genética
12.
Neuropathology ; 36(3): 227-36, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26607557

RESUMEN

Various types of eosinophilic neurons (ENs) are found in the post-ischemic brain. The aim of the present study was to elucidate the temporal and spatial profile of ENs, the expression of TUNEL staining and ultrastructural characteristics in the core and peripheral regions of the cortex post-ischemia. Unilateral forebrain ischemia was induced in Mongolian gerbils by transient common carotid artery occlusions, and the brains from 3 h to 2 weeks post-ischemia were prepared for morphometric, electron microscopy (EM) and TUNEL staining of the ENs. Light microscopy showed that ENs with minimally abnormal nuclei and swollen cell bodies appeared at 3 h in the ischemic core and at 12 h in the periphery. Thereafter, ENs with pyknosis and irregular atrophic cytoplasm peaked at 12 h, pyknosis with scant cytoplasm peaked at 4 days, and TUNEL-positive staining was observed in the ischemic core. In the ischemic periphery, ENs had slightly atrophic cytoplasm and sequentially developed pyknosis, karyorrhexis and karyolysis over 1 week. These cells were also positive for TUNEL. In EM, severe organelle dilation and vacuolization preceded chromatin fragmentation in the ischemic core, while chromatin fragmentation and homogenization were the vital characteristics in the ischemic periphery. There might be two region-dependent pathways for EN changes in the post-ischemic brain: pyknosis with cytoplasmic shrinkage in the core and nuclear disintegration with slightly atrophic cytoplasm in the periphery. These pathways were comparable to necrosis and proceeded from non-classical apoptosis to necrosis, respectively.


Asunto(s)
Isquemia Encefálica/patología , Muerte Celular , Neuronas/ultraestructura , Prosencéfalo/ultraestructura , Animales , Eosina Amarillenta-(YS) , Gerbillinae , Masculino , Coloración y Etiquetado
13.
PLoS One ; 10(8): e0135934, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26281014

RESUMEN

Fall dormancy (FD) in alfalfa (Medicago sativa L.) can be described using 11 FD ratings, is widely used as an important indicator of stress resistance, productive performance and spring growth. However, the contrasting growth strategies in internode length and internode number in alfalfa cultivars with different FD rating are poorly understood. Here, a growth chamber study was conducted to investigate the effect of FD on plant height, aboveground biomass, internode length, and internode number in alfalfa individuals in the early growth stages. In order to simulate the alfalfa growth environment in the early stage, 11 alfalfa cultivars with FD ratings from one to 11 were chosen and seeded at the greenhouse, and then were transplanted into an artificial growth chamber. The experimental design was a randomized complete block in a split-plot arrangement with three replicates. Plant height, above-ground biomass, internode length, and internode number were measured in early growth stage in all individuals. Our findings showed that plant height and the aboveground biomass of alfalfa did not significantly differ among 11 different FD rated cultivars. Also, internode length and internode number positively affected plant height and the aboveground biomass of alfalfa individuals and the average internode length significantly increased with increasing FD rating. However, internode number tended to sharply decline when the FD rating increased. Moreover, there were no correlations, slightly negative correlations, and strongly negative correlations between internode length and internode number in alfalfa individuals among the three scales, including within-FD ratings, within-FD categories and inter-FD ratings, respectively. Therefore, our results highlighted that contrasting growth strategies in stem elongation were adopted by alfalfa with different FD ratings in the early growth stage. Alfalfa cultivars with a high FD rating have longer internodes, whereas more dormant alfalfa cultivars have a larger number of internodes. There were tradeoffs between internode length and internode number in response to FD in alfalfa, which reflected certain scale-dependence.


Asunto(s)
Medicago sativa/crecimiento & desarrollo , Tallos de la Planta/crecimiento & desarrollo , Fenómenos Biológicos/fisiología , Biomasa
14.
Sci Rep ; 5: 11186, 2015 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-26084560

RESUMEN

The lack of a precisely-dated, unequivocal climate proxy from northern China, where precipitation variability is traditionally considered as an East Asian summer monsoon (EASM) indicator, impedes our understanding of the behaviour and dynamics of the EASM. Here we present a well-dated, pollen-based, ~20-yr-resolution quantitative precipitation reconstruction (derived using a transfer function) from an alpine lake in North China, which provides for the first time a direct record of EASM evolution since 14.7 ka (ka = thousands of years before present, where the "present" is defined as the year AD 1950). Our record reveals a gradually intensifying monsoon from 14.7-7.0 ka, a maximum monsoon (30% higher precipitation than present) from ~7.8-5.3 ka, and a rapid decline since ~3.3 ka. These insolation-driven EASM trends were punctuated by two millennial-scale weakening events which occurred synchronously to the cold Younger Dryas and at ~9.5-8.5 ka, and by two centennial-scale intervals of enhanced (weakened) monsoon during the Medieval Warm Period (Little Ice Age). Our precipitation reconstruction, consistent with temperature changes but quite different from the prevailing view of EASM evolution, points to strong internal feedback processes driving the EASM, and may aid our understanding of future monsoon behaviour under ongoing anthropogenic climate change.

15.
J Vet Diagn Invest ; 24(3): 568-71, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22529127

RESUMEN

Three Holstein sires were identified as complex vertebral malformation (CVM) carriers using the polymerase chain reaction-primer introduced restriction analysis (PCR-PIRA) method. Using the carriers as positive controls, the PCR mismatch amplification mutation assay (MAMA PCR) method was developed and validated by sequence analysis. With MAMA PCR, 154 Chinese Holstein sires were tested for CVM, among which 24 were confirmed to be CVM carriers. With DNA isolated from hair follicles, 10 daughters of one CVM-positive bull were detected, among which 7 were confirmed to be CVM carriers.


Asunto(s)
Enfermedades de los Bovinos/genética , Vértebras Cervicales/anomalías , Tamización de Portadores Genéticos/métodos , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinaria , Enfermedades de la Columna Vertebral/veterinaria , Animales , Bovinos , Enfermedades de los Bovinos/patología , ADN/química , ADN/genética , Femenino , Masculino , Mutación Puntual , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Enfermedades de la Columna Vertebral/genética , Enfermedades de la Columna Vertebral/patología
16.
Anal Bioanal Chem ; 394(1): 17-32, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19274456

RESUMEN

Communication between cells by release of specific chemical messengers via exocytosis plays crucial roles in biological process. Electrochemical detection based on ultramicroelectrodes (UMEs) has become one of the most powerful techniques in real-time monitoring of an extremely small number of released molecules during very short time scales, owing to its intrinsic advantages such as fast response, excellent sensitivity, and high spatiotemporal resolution. Great successes have been achieved in the use of UME methods to obtain quantitative and kinetic information about released chemical messengers and to reveal the molecular mechanism in vesicular exocytosis. In this paper, we review recent developments in monitoring exocytosis by use of UMEs-electrochemical-based techniques including electrochemical detection using micrometer and nanometer-sized sensors, scanning electrochemical microscopy (SECM), and UMEs implemented in lab-on-a-chip (LOC) microsystems. These advances are of great significance in obtaining a better understanding of vesicular exocytosis and chemical communications between cells, and will facilitate developments in many fields, including analytical chemistry, biological science, and medicine. Furthermore, future developments in electrochemical probing of exocytosis are also proposed.


Asunto(s)
Células/citología , Exocitosis , Nanoestructuras/química , Células/metabolismo , Electroquímica , Procedimientos Analíticos en Microchip , Microelectrodos , Tamaño de la Partícula
17.
Recent Pat Nanotechnol ; 3(1): 1-9, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19149750

RESUMEN

Silicon nanowires (SiNWs) have been demonstrated as one of the promising building blocks for future nanodevices such as field effect transistors, solar cells, sensors and lithium battery; much progress has been made in this field during last decades. In this review paper, the synthesis and physical properties of SiNWs are introduced briefly. Significant advances of SiNWs-related nanodevices reported in recent literature and registered patents are reviewed. The latest development and prospects of SiNWs-related nanodevices are also discussed.


Asunto(s)
Electroquímica/tendencias , Electrónica/instrumentación , Nanotecnología/instrumentación , Nanotubos/química , Nanotubos/ultraestructura , Patentes como Asunto , Silicio/química , Electroquímica/instrumentación , Nanotecnología/tendencias
18.
Biosens Bioelectron ; 24(3): 415-21, 2008 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-18585028

RESUMEN

In this paper, a novel NO electrochemical microsensor, which is fabricated by modifying the surface of a carbon fiber microdisk electrode (CFMDE, diameter: 5-7 microm) with single-walled carbon nanotubes (SWNTs) and Nafion membrane, is reported for the first time. The modification of SWNTs dramatically improves the sensitivity of CFMDEs, and the detection limit for NO is 4.3 nM that is nearly 10 times lower than that from the bare one and lower than most NO electrochemical sensors reported before. The Nafion membrane offers a good barrier to some interferents such as nitrite and ascorbic acid without losing response speed to NO. The sensor has been successfully applied to the measurement of NO release from single isolated human umbilical vein endothelial cells (HUVECs). Real-time amperometric data show that the addition of l-arginine (l-arg) or acetylcholine (ACh) can cause a quick increase in NO production with a maximum concentration of 232+/-44 nM (n=5) and 159+/-29 nM (n=5), respectively.


Asunto(s)
Técnicas Biosensibles/instrumentación , Carbono/química , Electrodos , Nanotubos de Carbono/química , Óxido Nítrico/análisis , Técnicas Biosensibles/métodos , Calibración , Fibra de Carbono , Células Cultivadas , Electroquímica , Células Endoteliales/metabolismo , Humanos , Microscopía Electrónica de Rastreo , Óxido Nítrico/metabolismo , Sensibilidad y Especificidad
19.
J Chromatogr B Analyt Technol Biomed Life Sci ; 866(1-2): 104-22, 2008 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-18262479

RESUMEN

Cells are the fundamental unit of life, and studies on cell contribute to reveal the mystery of life. However, since variability exists between individual cells even in the same kind of cells, increased emphasis has been put on the analysis of individual cells for getting better understanding on the organism functions. During the past two decades, various techniques have been developed for single-cell analysis. Capillary electrophoresis is an excellent technique for identifying and quantifying the contents of single cells. The microfluidic devices afford a versatile platform for single-cell analysis owing to their unique characteristics. This article provides a review on recent advances in single-cell analysis using capillary electrophoresis and microfluidic devices; focus areas to be covered include sampling techniques, detection methods and main applications in capillary electrophoresis, and cell culture, cell manipulation, chemical cytometry and cellular physiology on microfluidic devices.


Asunto(s)
Electroforesis Capilar/instrumentación , Microfluídica/instrumentación
20.
Nanotechnology ; 19(20): 205702, 2008 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-21825745

RESUMEN

Quaternary mixed-valence compound TlIn(4)S(5)Cl micro- and nanowires are prepared by partial substitution of chalcogen with halogen starting from a stoichiometric mixture of TlCl, In and S. Their electrical conductivity and gas sensitivity properties are investigated by using standard four-terminal systems. The specific nanowire resistivity is about 10(7) Ω cm and corresponds to the value of a typical undoped semiconductor in air. This resistivity is, however, extremely sensitive to NO(2) (sensitivity about 150) or NH(3), with a rapid response of about 2 s and recovery times. This phenomenon is supposed to be particularly important for future nanodevice applications.

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