Electroosmotic pumping is receiving increasing attention in recent years owing to the rapid development in micro total analytical systems. Compared with other micropumps, electroosmotic pumps (EOPs) offer a number of advantages such as creation of constant pulse-free flows and elimination of moving parts. The flow rates and pumping pressures of EOPs matches well with micro analysis systems. The common materials and fabrication technologies make it readily integrateable with lab-on-a-chip devices. This paper reviews the recent progress on EOP fabrications and applications in order to promote the awareness of EOPs to researchers interested in using micro-and nano-fluidic devices. The pros and cons of EOPs are also discussed, which helps these researchers in designing and constructing their micro platforms.

Complete surgical excisions with appropriate approaches have proven to be efficient and successful in the treatment of head and neck schwannomas.

A novel miniaturized capillary electrophoresis (CE) system is described where a Teflon AF-coated silica capillary serves both as the separation channel and as a transversely illuminated liquid core waveguide. This device uniquely uses flow injection (FI)-based split-flow sample introduction through a falling-drop interface. An H-channel structure fixed on a microscope glass slide utilizes a horizontal separation capillary with tubular sidearms on each end that serve as inlet and outlet flow-through electrode reservoirs. The inlet reservoir also functions as a falling-drop interface for coupling to the FI system. A blue LED is used as excitation source. A large-core optical fiber takes the emitted fluorescence to an inexpensive PMT with two layers of green plastic used for optical filtering. No focusing arrangement is needed. Continuous FI introduction of a series of 30-microL samples containing a mixture of of fluorescein isothiocyanate (FITC)-labeled amino acids allowed a throughput rate up to 144 samples/ h, with approximately 2% carryover and good precision (3.2% RSD). Baseline separation was achieved for FITC-labeled arginine, phenylalanine, glycine, and FITC in sodium tetraborate buffer (pH 9.5) with plate heights of 5.4-5.5 microm and plate numbers of 2.34 x 10(4)-2.37 x 10(4) under electrical field strengths of 214 V/cm for injection and 500 V/cm for separation (14-cm capillary, 48-microm i.d.). Detection limits (S/N = 3) were 1.3 microM for arginine and 1.9 microM for phenylalanine and glycine.

Muscle tissue represents an abundant, accessible, and replenishable source of adult stem cells for cell-based tissue and genetic engineering. A population of cells isolated from muscle exhibits both multipotentiality and self-renewal capabilities. Satellite cells, referred to by many investigators as muscle stem cells, are myogenic precursors that are capable of regenerating muscle and that demonstrate self-renewal properties; however, they are considered to be committed to the myogenic lineage. Muscle-derived stem cells (MDSCs), which may represent a predecessor of the satellite cell, are considered to possess a higher regeneration capacity and to exhibit better cell survival and a broader range of multilineage capabilities. Remarkably, MDSCs are not only able to differentiate into mesodermal cell types including the myogenic, adipogenic, osteogenic, chondrogenic, endothelial, and hematopoietic lineages, but also possess the potential to break germ layer commitment and differentiate into ectodermal lineages including neuron-like cells under certain conditions. This article reviews the current preclinical studies and potential clinical applications of MDSC-mediated gene therapy and tissue-engineering and methods for MDSC isolation, differentiation, and molecular characterization.

ObjectiveTo compare the clinical outcomes, including efficacy and complications, of Merocel versus Nasopore as a nasal packing material after nasal surgery.MethodsRelevant randomized controlled trials were identified from electronic databases (The Cochrane Library, PubMed, EMBASE, China National Knowledge Infrastructure and Chinese Biomedical Database). Conference proceedings and references from identified trials and review articles were also searched. Outcome measures were pain during nasal packing, pain and bleeding upon packing removal, pressure sensation, nasal blockage, formation of synechiae, mucosal healing, and patients' general satisfaction.ResultsSeven randomized controlled trials met criteria for analysis. Compared with Merocel, Nasopore significantly reduced patients' subjective symptoms including in situ pain (pain experienced while packing is in place), nasal pressure, pain and bleeding during packing removal, and increased patients' general satisfaction with nasal packing. There were no significant differences in nasal obstruction, adhesion and mucosal healing between the Merocel and Nasopore groups.ConclusionsPreliminary evidence suggests that Nasopore may be superior to Merocel as a nasal packing material with regard to in situ pain, pain and bleeding upon removal, pressure, and general satisfaction and does not differ from Merocel in terms of nasal obstruction, tissue adhesion, and long-term mucosal healing.

In this work, we demonstrate DNA separation and genotyping analysis in gel-free solutions using a nanocapillary under pressure-driven conditions without application of an external electric field. The nanocapillary is a ~50-cm-long and 500-nm-radius bare fused silica capillary. After a DNA sample is injected, the analytes are eluted out in a chromatographic separation format. The elution order of DNA molecules follows strictly with their sizes, with the longer DNA being eluted out faster than the shorter ones. High resolutions are obtained for both short (a few bases) and long (tens of thousands of base pairs) DNA fragments. Effects of key experimental parameters, such as eluent composition and elution pressure, on separation efficiency and resolution are investigated. We also apply this technique for DNA separations of real-world genotyping samples to demonstrate its feasibility in biological applications. PCR products (without any purification) amplified from Arabidopsis plant genomic DNA crude preparations are directly injected into the nanocapillary, and PCR-amplified DNA fragments are well resolved, allowing for unambiguous identification of samples from heterozygous and homozygous individuals. Since the capillaries used to conduct the separations are uncoated, column lifetime is virtually unlimited. The only material that is consumed in these assays is the eluent, and hence the operation cost is low.New, more cost-effective DNA separation methods are being sought to meet the need for simple and inexpensive assays for research and diagnostic purposes. Traditionally, DNA separations have been performed using slab-gel electrophoresis. A shift to capillary gel electrophoresis (CGE) 1 or capillary array electrophoresis (CAE) 2-4 has resulted in improved resolution and increased throughput. Both CGE and CAE use viscous polymer solutions (e.g., entangled solutions of linear polyacrylamide) as sieving matrices for size-based DNA separations. In addition to their cost, high pressures (e.g. 1000 psi) are often needed 5 to load and replenish these matrices after each run. Frequently, a coating is required on the inner wall of the capillary in order to obtain high quality separation results.To overcome the problems associated with the viscous polymer matrices, one would wish to separate DNA in gel-free (or free) solutions. 6-12 Unfortunately, DNA separations cannot normally be achieved by electrophoresis in gel-free solutions, 13 because the electrophoretic mobilities of all DNA molecules are virtually identical. Although a long DNA molecule possesses greater negative charge than a shorter molecule does, providing stronger pull, its large size induces more friction that limits its migration. These two forces largely balance one another, resulting in a mobility that is independent of the DNA size. Credit should be given to Noolandi 6 who suggested in 1992 that DNA could be electrophoretically separated in a gelfree solution if the molecules were attached to a monodisperse perturbing entity or a "dragtag". Becaus...

We report a unique property of nanocapillaries for chromatographic separations of ionic species. Due to the electric double layer overlap, ions are unevenly distributed inside a nanochannel, with counterions enriched near the wall and co-ions concentrated in the middle of the channel. As a pressure-driven flow is induced, the co-ions will move faster than the counterions. This differential transport results in a chromatographic separation. In this work, we introduce the fundamental mechanism of this separation technology and demonstrate its application for DNA separations. An outstanding feature of this technique is that each separation consumes less than 1 pL sample and generates less than 0.1 nL waste. We also apply this technique for separations of DNA molecules, and efficiencies of more than 1,00000 plates per meter are obtained.

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