다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Surface topographical factors influencing bacterial attachment

Erratum : An Overview of Injectable Polymeric Hydrogels for Tissue Engineering

In it for the long haul: Clusters of Pt nanowires (3D Pt nanoassemblies, Pt NA) serve as an electrocatalyst for low-temperature fuel cells. These Pt nanoassemblies exhibit remarkably high stability following thousands of voltage cycles and good catalytic activity, when compared with a commercial Pt catalyst and 20 % wt Pt catalyst supported on carbon black (20 % Pt/CB).

Self-Supported Interconnected Pt Nanoassemblies as Highly Stable Electrocatalysts for Low-Temperatur

While the bulk of the finished microbial genomes sequenced to date are derived from cultured bacterial and archaeal representatives, the vast majority of microorganisms elude current culturing attempts, severely limiting the ability to recover complete or even partial genomes from these environmental species. Single cell genomics is a novel culture-independent approach, which enables access to the genetic material of an individual cell. No single cell genome has to our knowledge been closed and finished to date. Here we report the completed genome from an uncultured single cell of Candidatus Sulcia muelleri DMIN. Digital PCR on single symbiont cells isolated from the bacteriome of the green sharpshooter Draeculacephala minerva bacteriome allowed us to assess that this bacteria is polyploid with genome copies ranging from approximately 200-900 per cell, making it a most suitable target for single cell finishing efforts. For single cell shotgun sequencing, an individual Sulcia cell was isolated and whole genome amplified by multiple displacement amplification (MDA). Sanger-based finishing methods allowed us to close the genome. To verify the correctness of our single cell genome and exclude MDA-derived artifacts, we independently shotgun sequenced and assembled the Sulcia genome from pooled bacteriomes using a metagenomic approach, yielding a nearly identical genome. Four variations we detected appear to be genuine biological differences between the two samples. Comparison of the single cell genome with bacteriome metagenomic sequence data detected two single nucleotide polymorphisms (SNPs), indicating extremely low genetic diversity within a Sulcia population. This study demonstrates the power of single cell genomics to generate a complete, high quality, non-composite reference genome within an environmental sample, which can be used for population genetic analyzes.

One Bacterial Cell, One Complete Genome

The investigation of human disease mechanisms is difficult due to the heterogeneity in gene expression and the physiological state of cells in a given population. In comparison to bulk cell measurements, single-cell measurement technologies can provide a better understanding of the interactions among molecules, organelles, cells, and the microenvironment, which can aid in the development of therapeutics and diagnostic tools. In recent years, single-cell technologies have become increasingly robust and accessible, although limitations exist. In this review, we describe the recent advances in single-cell technologies and their applications in single-cell manipulation, diagnosis, and therapeutics development.

Current Trends of Microfluidic Single-Cell Technologies.

Nanocellulose, a versatile platform: From the delivery of active molecules to tissue engineering applications.

The behaviors of cell to cell or cell to environment with their organelles and their intracellular physical or biochemical effects are still not fully understood. Analyzing millions of cells together cannot provide detailed information, such as cell proliferation, differentiation or different responses to external stimuli and intracellular reaction. Thus, single cell level research is becoming a pioneering research area that unveils the interaction details in high temporal and spatial resolution among cells. To analyze the cellular function, single cell electroporation can be conducted by employing a miniaturized device, whose dimension should be similar to that of a single cell. Micro/nanofluidic devices can fulfill this requirement for single cell electroporation. This device is not only useful for cell lysis, cell to cell fusion or separation, insertion of drug, DNA and antibodies inside single cell, but also it can control biochemical, electrical and mechanical parameters using electroporation technique. This device provides better performance such as high transfection efficiency, high cell viability, lower Joule heating effect, less sample contamination, lower toxicity during electroporation experiment when compared to bulk electroporation process. In addition, single organelles within a cell can be analyzed selectively by reducing the electrode size and gap at nanoscale level. This advanced technique can deliver (in/out) biomolecules precisely through a small membrane area (micro to nanoscale area) of the single cell, known as localized single cell membrane electroporation (LSCMEP). These articles emphasize the recent progress in micro/nanofluidic single cell electroporation, which is potentially beneficial for high-efficient therapeutic and delivery applications or understanding cell to cell interaction.

Recent Trends on Micro/Nanofluidic Single Cell Electroporation

Diamond-like nanocomposite (DLN) thin films, comprising the networks of a-C:H and a-Si:O were deposited on pyrex glass or silicon substrate using gas precursors (e.g., hexamethyldisilane, hexamethyldisiloxane, hexamethyldisilazane, or their different combinations) mixed with argon gas, by plasma enhanced chemical vapor deposition technique. Surface morphology of DLN films was analyzed by atomic force microscopy. High-resolution transmission electron microscopic result shows that the films contain nanoparticles within the amorphous structure. Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and x-ray photoelectron spectroscopy (XPS) were used to determine the structural change within the DLN films. The hardness and friction coefficient of the films were measured by nanoindentation and scratch test techniques, respectively. FTIR and XPS studies show the presence of CC, CH, SiC, and SiH bonds in the a-C:H and a-Si:O networks. Using Raman spectroscopy, we also found that the hardness of the DLN films varies with the intensity ratio ID/IG. Finally, we observed that the DLN films has a better performance compared to DLC, when it comes to properties like high hardness, high modulus of elasticity, low surface roughness and low friction coefficient. These characteristics are the critical components in microelectromechanical systems (MEMS) and emerging nanoelectromechanical systems (NEMS).

Characterization of diamond-like nanocomposite thin films grown by plasma enhanced chemical vapor deposition

© 2018 IOP Publishing Ltd. The ability to deliver foreign molecules into a single living cell with high transfection efficiency and high cell viability is of great interest in cell biology for applications in therapeutic development, diagnostics and drug delivery towards personalized medicine. Many chemical and physical methods have been developed for cellular delivery, however most of these techniques are bulk approach, which are cell-specific and have low throughput delivery. On the other hand, electroporation is an efficient and fast method to deliver exogenous biomolecules such as DNA, RNA and oligonucleotides into target living cells with the advantages of easy operation, controllable electrical parameters and avoidance of toxicity. The rapid development of micro/nanofluidic technologies in the last two decades, enables us to focus an intense electric field on the targeted cell membrane to perform single cell micro-nano-electroporation with high throughput intracellular delivery, high transfection efficiency and cell viability. This review article will emphasize the basic concept and working mechanism associated with electroporation, single cell electroporation and biomolecular delivery using micro/nanoscale electroporation devices, their fabrication, working principles and cellular analysis with their advantages, limitations, potential applications and future prospects.

https://iopscience.iop.org/article/10.1088/1361-6439/aae5ae/pdf

Tuhin Subhra Santra

Papers

Current Trends of Microfluidic Single-Cell Technologies.

Nanocellulose, a versatile platform: From the delivery of active molecules to tissue engineering applications.

Recent Trends on Micro/Nanofluidic Single Cell Electroporation

Characterization of diamond-like nanocomposite thin films grown by plasma enhanced chemical vapor deposition

Single-cell electroporation: current trends, applications and future prospects