Search

BACKGROUND AND OBJECTIVES Vasospasm is a thorny problem often encountered in microvascular surgery that seriously threatens the survival of vascularized tissue transfers. This investigation is dedicated to establishing a model of vasospasm and to evaluating the antispasmodic efficacy of 10 pharmacologic agents. STUDY DESIGN/MATERIALS AND METHODS Eighty Sprague-Dawley rats were used. After anesthesia and depilation, the femoral neurovascular bundle was exposed, and a pair of microsurgical forceps were used to trigger vasospasm of the femoral vessels by blunt dissection. Then, 10 pharmacological agents, namely, prostaglandin E1, sodium nitroprusside, magnesium sulfate, papaverine, normal saline, phentolamine, verapamil, 2% lidocaine hydrochloride, amrinone, and 12% lidocaine hydrochloride, were dripped to the femoral vessels, after which laser speckle contrast imaging was used to collect perfusion images, acquiring the perfusion and the inner caliber of the femoral vessels at multiple timepoints. Furthermore, blood perfusion and the time consumed to escape vasospasm and reach hyperperfusion in each group were calculated. The difference of spasmolytic efficacy among the agents was statistically analyzed by one-way analysis of variance. RESULTS There was a significant difference in antispasmodic ability among the 10 agents (P

New metal dithiocarbamate complex [(HOC2H4)2NCSS]2 Ni was synthesized by method of One-Pot synthesis and characterized by elemental analysis, IR spectra, melting point. The crystal structure was determined by X-ray single crystal diffraction. Complex [(HOC2H4)2NCSS]2Ni is monoclinic with space group P2(1)/c. Lattice parameters: a=6.3798(8) Å, b=11.8298(14) Å, c=11.4586(13) Å, β=93.63(0) °. Parameter ratio: a/b=0.5393, b/c=1.0324, c/a=1.7961. The data agreed well with the structure determined by X-ray single crystal diffraction.

A novel actinomycete strain, YN-5-1T, isolated from the rhizosphere soil of a medicinal plant, Aconitum napellus, was characterized by a polyphasic approach to determine its taxonomic position. The strain showed highest 16S rRNA gene sequence similarities of 97.3, 97.2 and 97.1 % to Nonomuraea turkmeniaca DSM 43926T, Nonomuraea ferruginea DSM 43553T and Nonomuraea candida DSM 45086T, respectively. A wide range of genotypic and phenotypic characteristics, as well as levels of DNA–DNA relatedness between strain YN-5-1T and N. turkmeniaca DSM 43926T (57.46 %), N. ferruginea DSM 43553T (53.50 %) and N. candida DSM 45086T (48.80 %), distinguished the novel isolate from its closest phylogenetic neighbours. The morphological characteristics of strain YN-5-1T were typical of the genus Nonomuraea. Chemotaxonomic characteristics, such as diagnostic diamino acid of the peptidoglycan, whole-cell sugars, phospholipid type, major menaquinone and major fatty acids, further supported the assignment of strain YN-5-1T to the genus Nonomuraea. The G+C content of the genomic DNA was 72.1 mol%. Based on the above data, strain YN-5-1T is considered to represent a novel species of the genus Nonomuraea, for which the name Nonomuraea flavida sp. nov. is proposed. The type strain is YN-5-1T ( = CCTCC AB 2012909T = KCTC 29143T).

A novel amperometric immunosensor for the detection of α-fetoprotein (AFP) based on the integration of microelectronic technology, mixed self-assembled monolayers (mixed SAMs), gold nanoparticles (nanogold) and enzyme amplification has been developed. Using microelectronic technology, an immunosensor was fabricated which has an “Au, Pt, Pt” three-microelectrode system and two microwells constructed by SU-8 photoresist on silicon wafer. Using mixed SAMs and nanogold, a mixed monolayer comprising cysteamine and 1,6-hexanedithiol was formed on the working electrode surface to assemble nanogold and further to immobilize AFP antibody for detecting AFP in human serum samples. The stepwise mixed SAMs and nanogold based immobilization procedure was characterized by means of cyclic voltammetry. The factors influencing the performance of the resulting immunosensor were studied in detail. After the addition of H2O2 and KI to the immunosensor incubated with AFP and further with horseradish peroxidase-labeled AFP antibody, the cathodic current varied linearly in concentration range of AFP from 15 to 350 ng/ml with a detection limit of 5 ng/ml. Moreover, the studied immunosensor has attractive advantages, such as miniaturization, compatibility with the complementary metal oxide semiconductor (CMOS) techniques, high specificity, good reproducibility and long-term stability, which make it potentially attractive for clinical immunoassays.

A new silicon-based amperometric microelectrode biosensor with consecutive platinization and polymerization of pyrrole is designed and fabricated with bulk micromachining technology. The biosensor consists of a p-type silicon substrate, two respective Au microelectrodes fabricated in two respective in-device micropools formed by anisotropic silicon wet etching, and an SU-8 microreaction pool. To our knowledge, consecutive platinization and polymerization of pyrrole is the first such use for surface modification. The biosensor aims for low unit cost, small dimensions and compatibility with CMOS technology. Successful experimental results have been achieved for glucose detection. Compared to conventional amperometric biosensors and amperometric microelectrode biosensors made with surface micromachining technology, it has several advantages, such as smaller sensitive surface area (1 mm × 1 mm), lower detection limit (1 × 10−4 M), larger linear range (1 × 10−4–1 × 10−2 M), larger sensitivity per unit area (39.640 nA mM−1 mm−2), better reproducibility (3.2% RSD for five detections) and stability (relative remaining sensitivity per unit area kept well above 95% after being stored in a clean container at room temperature for a month), easier to be made into arrays and to be integrated with processing circuitry, etc.

According to theoretical analysis and empirical verification based on IPAT identity, the evolutionary process of carbon dioxide emissions driven by technical advances over time generally follow in sequence three inverted U shape curves in the long run, which are the inverted U shape curve of carbon dioxide emissions intensity, carbon dioxide emissions per capita, and total carbon dioxide emissions respectively. According to three inverted U shape curves, the evolutionary process of carbon dioxide emissions can be divided into four stages, that is: stage before the peak of carbon dioxide emissions intensity, stage between the peak of carbon dioxide emissions intensity and the peak of carbon dioxide emissions per capita, stage between the peak of carbon dioxide emissions per capita and the peak of total carbon emissions, the last stage comes behind total carbon dioxide emissions. Four stages’ driving forces are: carbon-intensive technological advance, economic growth, carbon-reducing technical advances, carbon-reducing technical advances respectively. Finally, our conclusion is: carbon dioxide emissions evolutionary process follows the law of three inverted U shape curves in turn, if we take measures to dealing with climate change, we should not be divorced from the basic development stage.

In this paper, the Raman spectra of the cancer nude mouse serum were measured using surface-enhanced Raman scattering (SERS) with the silver colloid substrate. The result indicated that the SERS spectra of the serum increased several peaks compared with conventional Raman spectra. More ever, these peaks were so crucial for analysis of the serum component and structure so that the information of the protein, carbohydrate, lipid and other trace amounts component could be analyzed through SERS spectra. Therefore, SERS technique is reliably used to compare relative intensity shifts and to investigate the adsorption of biological molecular proteins on Ag nanoparticles.

A micro amperometric immunosensor with a novel antibody immobilization scheme has been developed to detect human immunoglobulin G (HIgG). The microsensor was fabricated using standard silicon micromachining technique, with the sensitive area of only 2 mm2 . A double exposure of SU-8 photoresist process was developed to create both the sensor pool and reaction pool. Antibody was immobilized using two-layer electrochemical polymers. Firstly polypyrrole was electropolymerized on the electrode as the transition layer. Then antibody and poly o-phenylenediamine were electropolymerized. This is a fast and simple method to immobilize antibody and is the first time to be used in amperometric immunoassay. At working potential of -0.3V, the immunosensor displayed a good linear dose-response behavior for HIgG concentrations between 5 and 355ng/ml. The response time was about 5 minutes

A new silicon-based bulk micro-machined amperometric microelectrode biosensor, especially its fabrication, is provided. We designed the biosensor and fabricated it with anisotropic silicon wet etching. P-type silicon wafers are used as substrates, and Au and SU-8 are used for making electrodes and micro reaction pools, respectively. To our knowledge, consecutive platinization and polymerization of pyrrole is firstly used for surface modification. Successful experimental results have been achieved for glucose detection. It has several advantages, such as smaller sensitive surface area (1 mm/spl times/1 mm), lower detection limit (1/spl times/10/sup 4/ M), broader linear range (1/spl times/10/sup -4/ -1/spl times/10/sup -2/ M), larger sensitive coefficient (39.640 nA/spl middot/mm/sup -2//sub /spl middot//mM/sup -1/), better replicability (RSD 3.2% for five respective detections) and stability (sensitive coefficient remains well above 95% after being stored in a clean container at room temperature for a month), easier to be made into arrays and to be integrated with processing circuitry, etc.

A new microdevice for measuring the thermal conductivity of thin film is presented. It is based on the static-state method, which is widely used and a simple technique for measuring the lateral thermal conductivity of thin film. The device is fabricated using micromachining process, which is 800/spl times/2000/spl mu/m bridge membrane with 30/spl times/100/spl mu/m beams. The heater and thermometer across the bridge membrane through the beams are used to create heat flux and to measure the temperature. On the membrane, heat flux is very uniform and the temperature is evenly distributed, which has been verified by simulation, making the system error smaller than conventional rectangular structure. Silicon nitride thin films with thickness from 0.5/spl mu/m to 2/spl mu/m have been investigated using the technique. The measurement result supports the size effect of the thermal conductivity for thin film.

A new silicon-based amperometric microelectrode biosensor made with bulk micromachining technology is provided. We designed this new biosensor and fabricated it with anisotropic silicon wet etching technique. P-type silicon wafers, Au and SU-8 are used for making substrate, microelectrode and micro reaction pool respectively. To our knowledge, consecutive platinization and polymerization of pyrrole is firstly used consecutively for microelectrode surface modification. The sensor aims for low unit cost, small dimensions and compatibility with CMOS technology. SU-8 micro reaction pools are made to contain detection solution to reduce reagent volume and unit cost. Bulk micromachining, platinization and polymerization of pyrrole enhance sensitive coefficient, thus helping to miniaturize its dimensions and to reduce unit cost. Using p-type silicon wafers as substrates make compatibility with CMOS technology possible. Successful experimental results have been achieved for glucose detection. Compared to conventional amperometric biosensors and amperometric microelectrode biosensors made with surface micromachining technology, it has several advantages, such as smaller sensing surface area (1 mm /spl times/ 1 mm), lower detection limit (1/spl times/10/sup -4/ M), larger sensitive coefficient (39.640 nA mM/sup -1/ mm/sup -2/), broader linear range (1/spl times/10/sup -4/-1/spl times//sup -2/ M), better replicability (3.2% RSD for five respective detections) and stability (enzyme efficiency remains well above 95% after being stored for a month), easier to be made into arrays and to be integrated with processing circuitry, etc.