Facile Synthesis of Porous Silicon Nanofibers by Magnesium Reduction for Application in Lithium Ion Batteries

We report a facile fabrication of porous silicon nanofibers by a simple three-stage procedure. Polymer/silicon precursor composite nanofibers are first fabricated by electrospinning, a water-based spinning dope, which undergoes subsequent heat treatment and then reduction using magnesium to be converted into porous silicon nanofibers. The porous silicon nanofibers are coated with a graphene by using a plasma-enhanced chemical vapor deposition for use as an anode material of lithium ion batteries. The porous silicon nanofibers can be mass-produced by a simple and solvent-free method, which uses an environmental-friendly polymer solution. The graphene-coated silicon nanofibers show an improved cycling performance of a capacity retention than the pure silicon nanofibers due to the suppression of the volume change and the increase of electric conductivity by the graphene.Korea Institute of Energy Technology Evaluation and Planning (Human Resources Development Program Grant 20144030200600

Successful Treatment of Protein-Losing Enteropathy Induced by Intestinal Lymphangiectasia in a Liver Cirrhosis Patient with Octreotide: A Case Report

A 47-yr-old man with hepatitis B virus associated liver cirrhosis was admitted to our hospital with diarrhea and generalized edema and diagnosed as protein-losing enteropathy due to intestinal lymphangiectasia by intestinal biopsy and 99mTc albumin scan. During hospitalization, he received subcutaneous octreotide therapy. After 2 weeks of octreotide therapy, follow-up albumin scan showed no albumin leakage, and the serum albumin level was sustained. We speculate that liver cirrhosis can be a cause of intestinal lymphangiectasia and administration of octreotide should be considered for patients with intestinal lymphangiectasia whose clinical and biochemical abnormalities do not respond to a low-fat diet

Endoscopic Pancreatic Sphincterotomy: Indications and Complications

Background/Aims: Although a few recent studies have reported the effectiveness of endoscopic pancreatic sphincterotomy (EPST), none has compared physicians' skills and complications resulting from the procedure. Thus, we examined the indications, complications, and safety of EPST performed by a single physician at a single center. Methods: Among 2,313 patients who underwent endoscopic retrograde cholangiopancreatography between January 1996 and March 2008, 46 patients who underwent EPST were included in this retrospective study. We examined the indications, complications, safety, and effectiveness of EPST, as well as the need for a pancreatic drainage procedure and the concomitant application of EPST and endoscopic sphincterotomy (EST). Results: Diagnostic indications for EPST were chronic pancreatitis (26 cases), pancreatic divisum (4 cases), and pancreatic cancer (8 cases). Therapeutic indications for EPST were removal of a pancreaticolith (10 cases), stent insertion for pancreatic duct stenosis (9 cases), nasopancreatic drainage (7 cases), and treatment of sphincter of Oddi dysfunction (1 case). The success rate of EPST was 95.7% (44/46). Acute complications of EPST included five cases (10.9%) of pancreatitis and one of cholangitis (2.2%). EPST with EST did not reduce biliary complications. Endoscopic pancreatic drainage procedures following EPST did not reduce pancreatic complications. Conclusions: EPST showed a low incidence of complications and a high rate of treatment success; thus, EPST is a relatively safe procedure that can be used to treat pancreatic diseases. Pancreatic drainage procedures and additional EST following EPST did not reduce the incidence of procedure-related complications

Multiple Feeding Strategy for Phase Transformation of GMP in Continuous Couette–Taylor Crystallizer

A continuous Couette–Taylor (CT) crystallizer with a multiple feed mode was developed to promote the phase transformation of guanosine 5-monophosphate (GMP). In drowning-out crystallization, amorphous GMP is initially precipitated and then transformed into hydrate GMP crystals via the spontaneous nucleation of hydrate crystals and consecutive dissolution of the amorphous GMP and growth of hydrate GMP crystals. Importantly, the multiple feeding strategy had a significant accelerating effect on the phase transformation process, resulting in the complete conversion of the amorphous GMP into hydrate crystals within an overall mean residence time of 2.5 min, even with a high GMP feed concentration of 152.8 g/L and low rotation speed of 300 rpm. Thus, the phase transformation in the continuous CT crystallizer with the multiple feed mode (feeding mode IV) was at least 2 times faster than the phase transformation with the conventional feeding mode (feeding mode I), and 10 times faster when compared to the phase transformation in a continuous MSMPR crystallizer. The effectiveness of the multiple feeding mode for the phase transformation can be explained in terms of independently controlling the supersaturation, mean residence time, seeding effect, and mass transfer rates in each region of CT crystallizer depending on the multiple feeding strategy and feeding distribution ratio

Role of Nanoparticle Selectivity in the Symmetry Breaking of Cylindrically Confined Block Copolymers

We have comprehensively studied the effect of nanoparticle selectivity on the self-assembly of symmetrical block copolymer (BCP) under cylindrical confinement using simulation and experiment. For the simulation, a coarse-grained molecular dynamics (CGMD) simulation has been utilized, and we investigated the confined assembly using nanoparticles with three different interactions with block copolymer: (i) neutral to both <i>A</i> (wall-attractive) and <i>B</i> (wall-repulsive) phases, (ii) <i>B</i> domain selective, and (iii) <i>A</i> domain selective. It is predicted that nonselective (neutral) nanoparticles (NPs) tend to be placed near the interface between radially alternating layers of <i>A</i> or <i>B</i> domains, while selective (<i>A</i> or <i>B</i>) NPs swell the corresponding phase, inducing discrete asymmetrical morphologies. We also find that pure asymmetrical BCP forms more radially perforated morphologies, while symmetrical BCP/NP forms more discrete morphologies. Experimentally, we have incorporated gold or magnetite NPs with the matching three types of selectivity toward symmetrical diblock PS-<i>b</i>-PI and electrospun them. The morphologies observed from our study have been quantified by morphological classification numbers to identify the degree of asymmetry formed. The qualitative and quantitative comparisons between experiment and simulation confirm the validity of the simulation tool and shed light on the NP’s role on breaking the symmetry of BCP under cylindrical confinement