비만아 부모의 돌봄 경험: q 방법론

Micromachining technology was used to prepare chemical analysis systems on glass chips (1 centimeter by 2 centimeters or larger) that utilize electroosmotic pumping to drive fluid flow and electrophoretic separation to distinguish sample components. Capillaries 1 to 10 centimeters long etched in the glass (cross section, 10 micrometers by 30 micrometers) allow for capillary electrophoresis-based separations of amino acids with up to 75,000 theoretical plates in about 15 seconds, and separations of about 600 plates can be effected within 4 seconds. Sample treatment steps within a manifold of intersecting capillaries were demonstrated for a simple sample dilution process. Manipulation of the applied voltages controlled the directions of fluid flow within the manifold. The principles demonstrated in this study can be used to develop a miniaturized system for sample handling and separation with no moving parts.

Micromachining a miniaturized capillary electrophoresis-based chemical analysis system on a chip

Owing to its high carrier mobility, conductivity, flexibility and optical transparency, graphene is a versatile material in micro- and macroelectronics. However, the low density of electrochemically active defects in graphene synthesized by chemical vapour deposition limits its application in biosensing. Here, we show that graphene doped with gold and combined with a gold mesh has improved electrochemical activity over bare graphene, sufficient to form a wearable patch for sweat-based diabetes monitoring and feedback therapy. The stretchable device features a serpentine bilayer of gold mesh and gold-doped graphene that forms an efficient electrochemical interface for the stable transfer of electrical signals. The patch consists of a heater, temperature, humidity, glucose and pH sensors and polymeric microneedles that can be thermally activated to deliver drugs transcutaneously. We show that the patch can be thermally actuated to deliver Metformin and reduce blood glucose levels in diabetic mice.

A graphene-based electrochemical device with thermoresponsive microneedles for diabetes monitoring and therapy

Capillarity and Wetting Phenomena: Drops, Bubbles, Pearls, Waves

The light microscope is traditionally an instrument of substantial size and expense. Its miniaturized integration would enable many new applications based on mass-producible, tiny microscopes. Key prospective usages include brain imaging in behaving animals for relating cellular dynamics to animal behavior. Here we introduce a miniature (1.9 g) integrated fluorescence microscope made from mass-producible parts, including a semiconductor light source and sensor. This device enables high-speed cellular imaging across ∼0.5 mm2 areas in active mice. This capability allowed concurrent tracking of Ca2+ spiking in >200 Purkinje neurons across nine cerebellar microzones. During mouse locomotion, individual microzones exhibited large-scale, synchronized Ca2+ spiking. This is a mesoscopic neural dynamic missed by prior techniques for studying the brain at other length scales. Overall, the integrated microscope is a potentially transformative technology that permits distribution to many animals and enables diverse usages, such as portable diagnostics or microscope arrays for large-scale screens.

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Miniaturized integration of a fluorescence microscope

Controlled release plays an essential role in formulating topical and transdermal drug delivery systems. In this study, we correlated the skin permeation of Sesamin, a lipophilic drug, with the rheological properties of two different organogel carriers, i.e., low molecular weight gelling agent N-lauroyl-l-glutamic acid di-n-butylamide (GP-1) and Carbopol polymeric gels. Although these two gels have distinct network structures, they share the same trend: the more rigid the gel network and the higher the gelator concentration, the lower the steady flux of Sesamin through skin. This negative correlation lies in the fact that organogel network hinders the diffusion of drug to the gel–skin interface; as a result, the depletion zone near the interface is non-negligible and contributes to the resistance of the whole diffusion system, and thus, the permeation flux is reduced. More interestingly, the dependence of the steady flux against gel complex modulus at the linear viscoelastic region followed a “universal” ...

Drug Permeation through Skin Is Inversely Correlated with Carrier Gel Rigidity

Dissolvable microneedle (MN) patches have been widely investigated for transdermal drug delivery. The dissolution rate of MN controls the status of drug release from the MN, which in turn determines drug absorption through skin. However, no systematic approaches have been reported to tune the dissolution profile of dissolvable MN matrices. This is the first study to show polyvinylpyrrolidone (PVP)-based dissolvable MN patches with varying dissolution profiles when PVP is copolymerized with cellulose materials. The MN patches were fabricated through thermal curing and photolithography in tandem. The various grades of pharmaceutical cellulose, such as hydroxypropyl methylcellulose and methyl cellulose, have been investigated as dissolution modifier incorporated in the MN patches. The resultant MN patches had dissolution profiles ranging from 45 min to 48 h. The dissolution rates varied with the grades of cellulose materials. Besides dissolution examination, the MN patches were characterized for their mechanical strength, moisture absorption, and skin penetration efficiency. All of the MN patches were able to penetrate the human skin in vitro. Overall, the PVP MN patches have great potential for skin applications as drug carriers with tunable dissolution profiles.

Microneedles with Tunable Dissolution Rate.

Rapid microneedle fabrication by heating and photolithography.

Objectives Reproducing human hair follicles in vitro is often limited by various reasons such as the lack of a systematic approach to culture distinct hair follicle cell types to reproduce their spatial relationship. Here, we reproduce hair follicle-like constructs resembling the spatial orientation of different cells in vivo, to study the role of keratinocytes in maintaining cellular compartmentalization among hair follicle-related cells. Materials and methods Dermal papilla (DP) cells, HaCaT keratinocytes and human dermal fibroblast (HDF) cells were seeded sequentially into three-dimensional (3D) microwells fabricated from polyethylene glycol diacrylate hydrogels. Quantitative polymerase chain reaction was used to compare inductive gene expression of 3D and two-dimensional (2D) DP. DP and HaCaT cells were transfected with green fluorescent protein and red fluorescent protein lentivirus, respectively, to enable cell visualization using confocal microscopy. Results The 3D DP cultures showed significantly enhanced expression of essential DP genes as compared 2D cultures. Core-shell configurations containing keratinocytes forming the outer shell and DP forming the core were observed. Migratory polarization was mediated by cell-cell interaction between the keratinocytes and HDF cells, while preserving the aggregated state of the DP cells. Conclusions Keratinocytes may play a role in maintaining compartmentalization between the DP and the surrounding HDF residing in the dermis, and therefore maintains the aggregative state of the DP cells, necessary for hair follicle development and function.

https://onlinelibrary.wiley.com/doi/epdf/10.1111/cpr.12668

Lifeng Kang

Papers

Drug Permeation through Skin Is Inversely Correlated with Carrier Gel Rigidity

Microneedles with Tunable Dissolution Rate.

Rapid microneedle fabrication by heating and photolithography.

Keratinocytes maintain compartmentalization between dermal papilla and fibroblasts in 3D heterotypic tri-cultures.

Proposome for transdermal delivery of tofacitinib.