Incorporation of a Metal Oxide Interlayer using a Virus-Templated Assembly for Synthesis of Graphene-Electrode-Based Organic Photovoltaics.

Transition metal oxide (TMO) thin films have been exploited as interlayers for charge extraction between electrodes and active layers in organic photovoltaic (OPV) devices. Additionally, graphene-electrode-based OPVs have received considerable attention as a means to enhance device stability. However, the film deposition process of a TMO thin-film layer onto the graphene electrode is highly restricted owing to the hydrophobic nature of the graphene surface; thus, the preparation of the device should rely on a vacuum process that is incompatible with solution processing. In this study, we present a novel means for creating a thin tungsten oxide (WO3 ) interlayer on a graphene electrode by employing an engineered biotemplate of M13 viruses, whereby nondestructive functionalization of the graphene and uniform synthesis of a WO3 thin interlayer are concurrently achieved. As a result, the incorporated virus-templated WO3 interlayer exhibited solar-conversion efficiency that was 20 % higher than that of conventional OPVs based on the use of a (3,4-ethylenedioxythiophene):poly(styrenesulfonate) ( PEDOT: PSS) interlayer. Notably, bilayer-structured OPVs with synergistically integrated WO3 /PEDOT:PSS achieved >60 % enhancement in device performance.

Multiscale porous interconnected nanocolander network with tunable transport properties.

A nanocolander network is developed by embedding mesoporous block copolymers inside the structural frame of a macroporous inverse-opal structure. Spontaneously formed macroconduits interconnecting the macropores are utilized as internal bypasses for enhancing the bulk transport properties. A demonstrative application for the membrane of the nanocolander network is of perfect size-selectivity for nanoparticle separation without compromising the high permeability of the transporting medium.

Nanoparticles of conjugated polymers prepared from phase-separated films of phospholipids and polymers for biomedical applications.

Phase separation in films of phospholipids and conjugated polymers results in nanoassemblies because of a difference in the physicochemical properties between the hydrophobic polymers and the polar lipid heads, together with the comparable polymer side-chain lengths to lipid tail lengths, thus producing nanoparticles of conjugated polymers upon disassembly in aqueous media by the penetration of water into polar regions of the lipid heads.

Endovascular management for retreatment of postsurgical intracranial aneurysms.

INTRODUCTION: Incomplete surgical treatment of intracranial aneurysms and recurrent postsurgical aneurysms are associated with a risk of rebleeding, and additional treatment is generally recommended. Surgical retreatment may carry a risk of procedural complications due to technical difficulty. We present here our experience with the endovascular approach for the retreatment of intracranial aneurysms that were initially treated with open surgery. METHODS: From January 2002 through January 2013, a total of 43 patients with 43 postsurgical index aneurysms were identified and underwent subsequent endovascular treatment. Clinical and radiological data were retrospectively reviewed. RESULTS: Thirty-one patients were surgically clipped before endovascular coiling and 12 patients were nonclipped, which included wrapping. Hemorrhagic presentation occurred in 21 patients prior to coiling. The interval between the initial surgical treatment and coiling varied from 0 days to 264 months (median, 9 months). Endovascular coiling resulted in the successful occlusion of 36 aneurysms (84 %). Procedure-related complications included asymptomatic thrombus formation in six patients, symptomatic cerebral infarction in two patients, and retroperitoneal hemorrhage in one patient. Delayed cerebral infarction occurred in two patients with a deployed stent. The procedure-related permanent morbidity and mortality rates were 6.9 and 0 %, respectively. Radiological follow-up evaluations beyond 6 months were available in 26 patients (60 %), which revealed major recanalization in three patients (11.5 %). There was no rebleeding during the follow-up period, which ranged from 3 to 115 months (mean, 34.5 months). CONCLUSION: Endovascular embolization may serve as a safe, efficacious, and durable treatment option in the management of postsurgical intracranial aneurysms.

Effect of stellate ganglion block on laryngopharyngeal reflux disease.

BACKGROUND: Laryngopharyngeal reflux (LPR) disease has many symptoms such as globus pharyngeus, excessive throat clearing and hoarseness. The aim of this study was to investigate the effect of stellate ganglion block (SGB) in addition to proton pump inhibitors (PPI) on LPR. METHODS: Fifty patients complaining of more than 3 typical LPR symptoms for over 3 months were enrolled in the study. The P group took PPI for 8 weeks. The SP group took PPI and interwent a series of 8 SGB procedure once a week during the period of treatment. The blocks were performed one at a time unilaterally on the right and left stellate ganglions by injecting 1% mepivacaine 6 ml. We evaluated the reflux symptom index (RSI) before treatment and following 4 weeks and 8 weeks of treatment in both groups. RESULTS: After 4 weeks of treatment, the RSI of the P group decreased, but not significantly, to 16.6 ± 6.8 compared with the baseline value of 19.2 ± 2.7 (P = 0.093), whereas the RSI of the SP group decreased significantly to 9.8 ± 3.3 compared with the baseline value of 19.0 ± 4.7 (P = 0.000). After 8 weeks of treatment, the RSI of the P group decreased significantly to 13.7 ± 6.7 (P = 0.001) and the RSI of the SP group also decreased significantly to 7.7 ± 3.4 (P = 0.000). There were significant differences in the RSI between the two groups after 4 weeks (P = 0.000) and 8 weeks (P = 0.001) of treatment. CONCLUSIONS: The symptoms of LPR improved earlier when PPI therapy was combined with SGB compared with PPI therapy alone.

A simple one-step assay platform based on fluorescence quenching of macroporous silicon.

We synthesized 3D macroporous silicon through a simple electrochemical dissolution process and systematically estimated its protein adsorption and effect on fluorescence emission. Compared with conventional 2D polystyrene plate, the macroporous silicon showed a superior protein adsorption capacity and significant fluorescence quenching effect. We developed a 3D macroporous silicon-based adenosine assay system through the following fabrication process: streptavidin molecules that have been immobilized on the surface of macroporous silicon are attached with biotin-linked and adenosine-specific DNA aptamer, followed by hybridization between the attached aptamer and fluorescent chemical (carboxytetramethylrhodamine/CTMR) that is conjugated with a short complementary DNA sequence. In the absence of adenosine, the aptamer-CTMR complexes remain closely attached to the surface of porous silicon, hence fluorescence being significantly quenched. Upon binding to adenosine, the DNA aptamer is subject to structure switching that leads to dissociation of CTMR from DNA aptamer, and consequently the CTMR fluorescence is restored, indicating a simple one-step assay of adenosine. Compared to the conventional 2D PS and ZnO nanorods-based assays, adenosine at much lower (sub-micromolar) concentration was successfully detected through the 3D macroporous silicon-based assay. The three-dimensionally and densely immobilized aptamer probes and effective fluorescence quenching on the surface of macroporous silicon enables adenosine to be detected at lower levels. Although the adenosine detection is reported here as a proof-of-concept, the developed macroporous silicon-based simple one-step assay platform can be applied in general to fluorescence quenching -based detection of many other biomolecules.

Long-term Study of Sialodochoplasty for Preventing Submandibular Sialolithiasis Recurrence.

OBJECTIVES: The transoral removal of stones by sialodochoplasty has been popularized in the treatment of submandibular sialolithiasis. However, the effectiveness of sialodochoplasty is controversial, and there are no reports on the long-term outcomes of this procedure. The purpose of this study was to assess the effectiveness and long-term outcomes of sialodochoplasty in patients with submandibular sialolithiasis. METHODS: We conducted a cross-sectional study that included retrospective chart reviews and prospective telephone or interview surveys of 150 patients treated for submandibular sialolithiasis from March 2001 to January 2008. The patients were treated with two different procedures by two different surgeons. One surgeon performed a transoral sialolithectomy without sialodochoplasty in 107 patients (SS group), and the other surgeon performed a transoral sialolithectomy with sialodochoplasty in 43 patients (SP group). RESULTS: The success rate of transoral sialolithectomy was 98.1% in the SS group and 93% in the SP group. The recurrence rates of symptoms or stones were 1.9% and 4.7% in the SS and SP groups, respectively. The incidence of postoperative transient hypoesthesia was 13.1% in the SS group and 34.9% in the SP group. The mean operating times were 29.79 and 47.44 minutes in the SS and SP groups, respectively. The mean percentage of general anesthesia was 42.1% in the SS group and 83.7% in the SP group. CONCLUSION: Sialodochoplasty in addition to transoral sialolithectomy for submandibular sialolithiasis did not affect the rate of symptom or stone recurrence, but did increase the postoperative hypoesthesia incidence and general anesthesia percentage.

Hierarchical nanoflake surface driven by spontaneous wrinkling of polyelectrolyte/metal complexed films.

A mechanical or physical change observed in nanocomposite thin films has recently offered new opportunities to generate intriguing nanostructures. In this study, we present a novel means of creating a hierarchically developed nanoflake structure by exploiting surface wrinkles that occur during the incorporation process of metallic nanoparticles into layer-by-layer assembled polyelectrolyte multilayer (PEM) thin films. The PEM film composed with linear polyethylenimine (LPEI) and poly(acrylic acid) (PAA) allows for facilitated cationic exchange reaction within the film even after the electrostatic complexation and chemical cross-linking reaction. The subsequent reduction process induces an in situ complexation of metallic nanoparticles with a PEM matrix, causing an accumulation of lateral compressive stress for surface wrinkling. The wrinkling characteristics of the complexed films can be theoretically interpreted by employing the gradationally swollen film model, whereby a gradual change in the elastic property along the axial direction of the film can be appropriately reflected. In addition, wrinkled surfaces are further processed to form vertically aligned and hierarchically ordered nanoflakes after selective removal of the PEM matrix with plasma ashing. Consequently, superhydrophobic surface properties (water contact angle = 170°, sliding angle <1°) can be attained from the hierarchical nanoflake structure. The method presented here is advantageous in that large-scale preparation can be readily implemented by a stepwise dipping process without resorting to specific patterning or a serially applied complex structuring process, which can provide a promising platform technique for various surface engineering applications.

Spontaneous surface flattening via layer-by-layer assembly of interdiffusing polyelectrolyte multilayers.

We report a facile means to achieve planarization of nonflat or patterned surfaces by utilizing the layer-by-layer (LbL) assembly of highly diffusive polyelectrolytes. The polyelectrolyte pair of linear polyethylenimine (LPEI) and poly(acrylic acid) (PAA) is known to maintain intrinsic diffusive mobility atop or even inside ionically complexed films prepared by LbL deposition. Under highly hydrated and swollen conditions during the sequential film buildup process, the LbL-assembled film of LPEI/PAA undergoes a topological self-deformation for minimizing surface area to satisfy the minimum-energy state of the surface, which eventually induces surface planarization along with spontaneous filling of surface textures or nonflat structures. This result is clearly different from other cases of applying nondiffusive polyelectrolytes onto patterned surfaces or confined structures, wherein surface roughening or incomplete filling is developed with the LbL assembly. Therefore, the approach proposed in this study can readily allow for surface planarization with the deposition of a relatively thin layer of polyelectrolyte multilayers. In addition, this strategy of planarization was extended to the surface modification of an indium tin oxide (ITO) substrate, where surface smoothing and enhanced optical transmittance were obtained without sacrificing the electronic conductivity. Furthermore, we investigated the potential applicability of surface-treated ITO substrates as photoelectrodes of dye-sensitized solar cells prepared at room temperature. As a result, an enhanced photoconversion efficiency and improved device characteristics were obtained because of the synergistic role of polyelectrolyte deposition in improving the optical properties and acting as a blocking layer to prevent electron recombination with the electrolytes.

Spin-assembled layer-by-layer films of weakly charged polyelectrolyte multilayer.

We investigate the effect of film deposition methods on the film properties of layer-by-layer assembled polyelectrolyte multilayers. Multilayered structures of linear polyethylenimine (LPEI) and poly(acrylic acid) (PAA) are prepared by using conventional dipping-based assembly as well as spin-assisted assembly. While the polyelectrolyte interpenetration by the diffusion motion of LPEI species is allowed in dipping-based assembly, an instantaneously and kinetically frozen phase of the film deposition is obtainable from spin-assisted assembly. Being kept from the interdiffusion of LPEI, a stratified internal structure is expected in the spin-assisted assembly, which is completely contrasted to the intermixed phase in the dipping-based assembly. The ability to control the inner structure of the multilayered film enables us to manipulate the physical properties or chemical activity of the functionalized thin films. We also demonstrate that the control over the strength of polyelectrolyte interdiffusion on a very top surface can be utilized for a quantitative manipulation on the degree of macromolecular self-assembly of nanomaterials.

Is lack of placement of drains after thyroidectomy with central neck dissection safe? A prospective, randomized study.

OBJECTIVE: Selective use of drains after thyroidectomy has been suggested in the literature. Although the safety of thyroidectomy without drains has been reviewed, there is little specific data available to identify the safety of thyroidectomy combined with central neck dissection (CND) without drains. This study aims to determine the feasibility and safety of thyroidectomy without drains, especially in cases of combined CND. STUDY DESIGN: Prospective, randomized study. MATERIALS AND METHODS: One hundred ninety-eight consecutive thyroidectomized patients were enrolled in this study. Drain group (n = 101) consisted of 41 hemithyroidectomies (HT), 28 total thyroidectomies (TT), and 32 total TT with CND. No-drain group (n = 97) consisted of 42 HT, 18 TT, and 37 TT with CND. The following variables were examined: perioperative complications (hemorrhage, hematoma, seroma), intraoperative bleeding, operation time, volume of resected thyroid gland, time of hospital discharge after operation, duration of drain placement, and total amount of drainage (drain group). RESULTS: There were no significant differences in age, sex, volume of resected thyroid gland, types of operation, operation time, and histopathlologic diagnosis between two groups. In the drain group, overall perioperative complications occurred in seven (7/101, 6.9%) patients. In the no-drain group, overall perioperative complications occurred in nine (10/97, 10.3%) patients. There was no significant difference in overall perioperative complications between the drain and no-drain groups, even in cases of performing CND. Time of hospital discharge after operation was significantly shorter in the no-drain group than the drain group (P < .05). CONCLUSIONS: We conclude that thyroidectomy without drains is safe and effective even in combination with CND and appears to confer several advantages over the routine drainage method. In addition, we achieved significant reduction of hospital stay, which led to a reduction in costs for the patients.