RESUMEN
A new species of Nemacheilidae, Triplophysa sanduensis sp. nov., is described here based on specimens collected from a small cave in Dengguang Village, Zhonghe Town, Sandu County, Guizhou Province, China. The new species can be distinguished from its congeners by the following combination of characters: branched dorsal-fin rays 8-9; branched pectoral-fin rays 8-9; branched pelvic-fin rays 5; branched anal-fin rays 5; vertebrae 4+37; snout length 45.5-50.1% of head length; postdorsal length 39.0-42.8% of standard length; caudal-peduncle depth/caudal-peduncle length range from 56.4% to 71.9%; the posterior chamber of the gas bladder degenerated; body elongated, covered by scattered scales; eyes present and normal in size, not reduced or absent; and a complete lateral line. A phylogenetic analysis based on the mitochondrial cytochrome oxidase subunit 1 (COI) gene resolved Triplophysa sanduensis as sister to Triplophysa longliensis. Kimura's 2-parameter genetic distance of the COI gene sequences between these two species was 1.9%.
Asunto(s)
Cipriniformes , Animales , China , Ojo , FilogeniaRESUMEN
Recent biochemical results suggest that auxin (IAA) efflux is mediated by a vesicular cycling mechanism, but no direct detection of vesicular IAA release from single plant cells in real-time has been possible up to now. A TiC@C/Pt-QANFA micro-electrochemical sensor has been developed with high sensitivity in detection of IAA, and it allows real-time monitoring and quantification of the quantal release of auxin from single plant protoplast by exocytosis.
Asunto(s)
Técnicas Electroquímicas , Ácidos Indolacéticos/análisis , Nanocables/química , Plantas/química , Carbono/química , Exocitosis , Microelectrodos , Tamaño de la Partícula , Platino (Metal)/química , Protones , Propiedades de Superficie , Factores de Tiempo , Titanio/químicaRESUMEN
Reproducing the physiological environment of blood vessels for the in vitro investigation of endothelial cell functions is very challenging. Here, we describe a vascular-like structure based on a three-dimensional (3D) gelatin chip with good compatibility and permeability which is also cost-effective and easy to produce. The controllable lumen diameter and wall thickness enable close mimicking of blood vessels in vitro. The 3D gelatin matrix between adjacent lumens is capable of generating soluble-factor gradients inside, and diffusion of molecules with different molecular weights through the matrix is studied. The cultured human umbilical vein endothelial cells proliferate on the gelatin lumen linings to form a vascular lumen. The hemodynamic behavior including adhesion, alignment of endothelial cells (ECs) under shear stress and pulsatile stretch is studied. Furthermore, a microelectrode comprising TiC/C nanowire arrays is fabricated to detect nitric oxide with sub-nM detection limits and NO generation from the cultured ECs is monitored in real time. This vascular model reproduces the surrounding parenchyma of endothelial cells and mimics the hemodynamics inside blood vessels very well, thereby enabling potential direct investigation of hemodynamics, angiogenesis, and tumor metastasis in vitro.
Asunto(s)
Carbono/química , Gelatina/química , Técnicas Analíticas Microfluídicas/instrumentación , Nanotubos de Carbono/química , Nanocables/química , Óxido Nítrico/análisis , Talio/química , Proliferación Celular , Células Cultivadas , Difusión , Células Endoteliales/citología , Células Endoteliales/metabolismo , Humanos , Microelectrodos , Peso Molecular , Óxido Nítrico/biosíntesisRESUMEN
Electrochemical techniques based on ultramicroelectrodes (UMEs) play a significant role in real-time monitoring of chemical messengers' release from single cells. Conversely, precise monitoring of cells in vitro strongly depends on the adequate construction of cellular physiological microenvironment. In this paper, we developed a multilayer microdevice which integrated high aspect ratio poly(dimethylsiloxane) (PDMS) microfluidic device for long-term automated perfusion culture of cells without shear stress and an independently addressable microelectrodes array (IAMEA) for electrochemical monitoring of the cultured cells in real time. Novel design using high aspect ratio between circular "moat" and ring-shaped micropillar array surrounding cell culture chamber combined with automated "circular-centre" and "bottom-up" perfusion model successfully provided continuous fresh medium and a stable and uniform microenvironment for cells. Two weeks automated culture of human umbilical endothelial cell line (ECV304) and neuronal differentiation of rat pheochromocytoma (PC12) cells have been realized using this device. Furthermore, the quantal release of dopamine from individual PC12 cells during their culture or propagation process was amperometrically monitored in real time. The multifunctional microdevice developed in this paper integrated cellular microenvironment construction and real-time monitoring of cells during their physiological process, and would possibly provide a versatile platform for cell-based biomedical analysis.