Cutting nanodisks in graphene down to 20 nm in diameter.

A direct focused He+beam direct machining is presented to fabricate solid-state nano-disk at the surface of a graphene multilayer micro-flake deposited on an Au/Ti/sapphire surface. At irradiation doses larger than 5.0 × 1017ions cm-2and with a beam size well below 1 nm, graphene disks down to 20 nm in diameter have been machined with for nano-disk down to 50 nm in diameter, a central hole for preparing the positioning of a rotation axle. The local heat generated by this irradiation is inducing a partial graphene amorphization and deformation, leading to a complete graphene nano-disk vaporization at doses larger than 5 × 1018ions cm-2. A dry transfer printing technique followed by a graphene surface cleaning was used to transfer the nano-disks from its initial surface to a fresh and clean surface. Tapping mode atomic force micrograph have been recorded to follow the vaporization as a function of the He+dose to confirm the graphene solid-state nano-disk fabrication limit to about 20 nm with this process.

Sorghum (Sorghum bicolor) Extract-Induced Adipogenesis Is Independent of PPARγ Ser273 Phosphorylation in 3T3-L1 Adipocytes.

Previously we showed that the water-soluble fraction of sorghum extract (SE) improves adipogenesis in 3-isobutyl-1-methylxanthine (IBMX)/dexamethasone/insulin (MDI)/thiazolidinedione (TZD)-induced 3T3-L1 preadipocytes but downregulates genes related to peroxisome proliferator-activated receptor γ (PPARγ) and adipogenesis in both MDI- and MDI/TZD-induced 3T3-L1 adipocytes. In this study, we showed that SE treatment altered the accumulation of stained lipids in 3T3-L1 adipocytes induced by MDI/troglitazone (Tro). Immunoblot analyses indicated that SE treatment reduced adipocyte protein 2 (aP2) expression and induced peroxisome proliferator-activated receptor α (PPARα) protein expression in the presence of Tro in 3T3-L1 adipocytes. MDI/Tro treatment, but not MDI treatment, of 3T3-L1 cells induced PPARγ phosphorylation at Ser273. SE downregulated PPARγ expression in MDI-induced 3T3-L1 adipocytes and did not affect its phosphorylation at Ser273 in MDI- and MDI/Tro-induced 3T3-L1 adipocytes. Therefore, SE likely promotes adipogenesis and lipid metabolism in 3T3-L1 preadipocytes by cooperating with Tro independent of PPARγ Ser273 phosphorylation.

Evaluation of Drug-Loading Ability of Poly(Lactic Acid)/Hydroxyapatite Core-Shell Particles.

Poly(lactic acid)/hydroxyapatite (PLA/HAp) core-shell particles are prepared using the emulsification method. These particles are safe for living organisms because they are composed of biodegradable polymers and biocompatible ceramics. These particles are approximately 50-100 nm in size, and their hydrophobic substance loading can be controlled. Hence, PLA/HAp core-shell particles are expected to be used as drug delivery carriers for hydrophobic drugs. In this work, PLA/HAp core-shell particles with a loading of vitamin K1 were prepared, and their drug-loading ability was evaluated. The particles were 40-80 nm in diameter with a PLA core and a HAp shell. The particle size increased with an increase in the vitamin K1 loading. The drug-loading capacity (LC) value of the particles, an indicator of their drug-loading ability, was approximately 250%, which is higher than the previously reported values. The amount of vitamin K1 released from the particles increased as the pH of the soaking solution decreased because the HAp shell easily dissolved under the acidic conditions. The PLA/HAp particles prepared in this work were found to be promising candidates for drug delivery carriers because of their excellent drug-loading ability and pH sensitivity.

Local heat generated by a focused He+ ion beam.

A focused He+ beam with a beam diameter less than 1 nm is heating up the targeted surface for a He+ dose larger than 1 × 1020 ions cm-2. The temperature can reach 1000 °C locally, resulting in surface decomposition or chemical reactions. This temperature was measured by fabricating gold nanodisks down to 20 nm in diameter and 10 nm in thickness on mica and sapphire surfaces. The melting and vaporization of these nanodisks were used to determine this temperature according to the known gold nanocluster melting temperature variations as a function of their volume. This local heat production is very negative for precise He+ nanolithography resist processes but advantageous without a resist when used to directly nano-sculpture a nanomaterial when a very thermally conductive support like sapphire is selected.

Tunable Magnetism of Organometallic Nanoclusters by Graphene Oxide On-Surface Chemistry.

Assembly of interacting molecular spins is an attractive candidate for spintronic and quantum computing devices. Here, we report on-surface chemical assembly of aminoferrocene molecules on a graphene oxide (GO) sheet and their magnetic properties. On the GO surface, organometallic molecules having individual spins through charge transfer between the molecule and the sheet are arranged in nanoclusters having diameters of about 2 nm. The synthetic fine tuning of the reaction time enables to change the interspacing between the nanoclusters, keeping their size intact. Their magnetism changes from paramagnetic behavior to collective one gradually as the interspacing decreases. The creation of collective nature among weakly interacting molecular spins through their nanoscale arrangement on the GO surface opens a new avenue to molecular magnetism.

Evolution of bidirectional sex change and gonochorism in fishes of the gobiid genera Trimma, Priolepis, and Trimmatom.

Size-advantage and low-density models have been used to explain how mating systems favor hermaphroditism or gonochorism. However, these models do not indicate historical transitions in sexuality. Here, we investigate the evolution of bidirectional sex change and gonochorism by phylogenetic analysis using the mitochondrial gene of the gobiids Trimma (31 species), Priolepis (eight species), and Trimmatom (two species). Trimma and Priolepis formed a clade within the sister group Trimmatom. Gonadal histology and rearing experiments revealed that Trimma marinae, Trimma nasa, and Trimmatom spp. were gonochoric, whereas all other Trimma and Priolepis spp. were bidirectional sex changers or inferred ones. A maximum-likelihood reconstruction analysis demonstrated that the common ancestor of the three genera was gonochoristic. Bidirectional sex change probably evolved from gonochorism in a common ancestor of Trimma and Priolepis. As the gonads of bidirectional sex changers simultaneously contain mature ovarian and immature testicular components or vice versa, individuals are always potentially capable of functioning as females or males, respectively. Monogamy under low-density conditions may have been the ecological condition for the evolution of bidirectional sex change in a common ancestor. As T. marinae and T. nasa are a monophyletic group, gonochorism should have evolved from bidirectional sex change in a common ancestor.

Controlled Fabrication of Silk Protein Sericin Mediated Hierarchical Hybrid Flowers and Their Excellent Adsorption Capability of Heavy Metal Ions of Pb(II), Cd(II) and Hg(II).

Fabrication of protein-inorganic hybrid materials of innumerable hierarchical patterns plays a major role in the development of multifunctional advanced materials with their improved features in synergistic way. However, effective fabrication and applications of the hybrid structures is limited due to the difficulty in control and production cost. Here, we report the controlled fabrication of complex hybrid flowers with hierarchical porosity through a green and facile coprecipitation method by using industrial waste natural silk protein sericin. The large surface areas and porosity of the microsize hybrid flowers enable water purification through adsorption of different heavy metal ions. The high adsorption capacity depends on their morphology, which is changed largely by sericin concentration in their fabrication. Superior adsorption and greater selectivity of the Pb(II) ions have been confirmed by the characteristic growth of needle-shaped nanowires on the hierarchical surface of the hybrid flowers. These hybrid flowers show excellent thermal stability even after complete evaporation of the protein molecules, significantly increasing the porosity of the flower petals. A simple, cost-effective and environmental friendly fabrication method of the porous flowers will lead to a new solution to water pollution required in the modern industrial society.

A new approach to molecular self-assembly through formation of dipeptide-based unique architectures by artificial supersaturation.

Morphological transition and the fabrication of unique architectures through molecular self-assembly of dipeptides are caused by the formation of a small nucleus in artificial supersaturation, achieved by quick drying of the solvent due to the local Joule heating. The growth mechanism of "diatom-like" porous microspheres and microtubes is proposed on the basis of several new techniques developed in the study.

Stabilities of the Divalent Metal Ion Complexes of a Short-Chain Polyphosphate Anion and Its Imino Derivative.

ABSTRACT: The stability constants of ML-type complexes of the two linear triphosphate ligand anion analogues triphosphate ([Formula: see text]) and diimidotriphosphate ([Formula: see text]) were investigated thermodynamically using potentiometric titrations according to Schwarzenbach's procedure. The stability constants of the ML-type complexes of different divalent metal ions with [Formula: see text] are larger than those of the corresponding complexes with [Formula: see text] because of the greater basicity of the imino group. The order of the stability constants for the ML-type complexes follows the Irving-Williams order, indicating that only non-bridging oxygen atoms are coordinated directly to the different metal ions in both ligands, and that the imino groups cannot participate in coordination to the metal ions. In the complexation reactions of the Ca2+, Sr2+, Ba2+-[Formula: see text] and Cu2+, Zn2+, Ni2+-[Formula: see text] systems, each metal ion forms an enthalpically stable complex, and there was no suggestion of a conspicuous entropic effect based on the chelate effect. Monodentate complexes that are strongly coordinated with the ligands were therefore formed, whereas entropically stable bidentate complexes were formed in the complexation reactions of the Cu2+, Zn2+, Ni2+-[Formula: see text] and Ca2+, Ba2+, Sr2+-[Formula: see text] systems. According to the HSAB concept, hard metal cations such as Ca2+, Ba2+ and Sr2+ should bind to the harder oxygen atoms rather than the softer nitrogen atoms of the imidopolyphosphate anions, preventing direct coordination to the imino nitrogen atom.

Revision of the Indo-West Pacific genus Brachypterois (Scorpaenidae: Pteroinae), with description of a new species from northeastern Australia.

A taxonomic revision of the scorpaenid genus Brachypterois resulted in three valid species. Brachypterois serrulifer Fowler 1938, previously regarded as ajunior synonym of Sebastes serrulatus Richardson 1846, can be distinguished from its congeners by having usually 16 pectoral-fin rays (vs. 15 in the congeners) and 0-22 spines on the median lateral ridge of the maxilla (vs. almost always absent), in addition to longer dorsal- and anal-fin soft rays, relatively fewer large dark spots on the caudal fin, and the posterior lacrimal spines usually directed ventrally. Brachypterois curvispina sp. nov., described on the basis of 32 specimens, can be distinguished from B. serrulata (Richardson 1846) by having fewer number of scale rows in the longitudinal series 41-45 (vs. 44-51 in B. serrulata); relatively long head, its length 41.6-44.5 (mean 43.1)% SL [vs. 38.3-43.1 (mean 40.2)% SL]; posterior lacrimal spines usually directed posteriorly, with the tip curved strongly upward in large males (vs. simply directed posteroventrally); and posteriorly directed spine(s) on the posterior corner of the outer angular ridge (vs. directed ventrally). Brachypterois serrulifer is distributed widely in the Indo-West Pacific, whereas distributional ranges of B. curvispina sp. nov. and B. serrulata are restricted to northeastern Australia and the northwestern Pacific, respectively. Intraspecific variation, including sexual dimorphism and ontogenetic changes in the three species are described in detail. A neotype, collected from southern Taiwan, is designated for S. serrulatus Richardson 1846.

Enhancing the humidity sensitivity of Ga2O3 /SnO2 core/shell microribbon by applying mechanical strain and its application as a flexible strain sensor.

The humidity sensitivity of a single ß-Ga(2) O(3) /amorphous SnO(2) core/shell microribbon on a flexible substrate is enhanced by the application of tensile strain and increases linearly with the strain. The strain-induced enhancement originates from the increase in the effective surface area where water molecules are adsorbed. This strain dependence of humidity sensitivity can be used to monitor the external strain. The strain sensing of the microribbon device under various amounts of mechanical loading shows excellent reliability and reproducibility with a gauge factor of -41. The flexible device has high potential to detect both humidity and strain at room temperature. These findings and the mechanism involved are expected to pave the way for new flexible strain and multifunctional sensors.

Controlling semiconducting and insulating states of SnO2 reversibly by stress and voltage.

By applying mechanical stress (by bending a flexible substrate) and an appropriate voltage, the conductance of a single-crystal SnO(2) microrod on a flexible substrate can be tuned in a reversible and nonvolatile manner. The creation and elimination of lattice defects controlled by strain and electrical healing is the origin of this novel transition. A SnO(2) microrod changes continually from its normal semiconducting state to an insulating state by bending the flexible substrate. The insulating state is maintained even after straightening the substrate. Interestingly, by applying an appropriate voltage, the defects are electrically healed and the insulating state reverts to the original semiconducting state. The structural changes in the SnO(2) microrod observed in the Raman spectra are consistent with the nonvolatile property of the transport. This flexible SnO(2) device with the reversible and nonvolatile modification of electrical properties is expected to lead to a better understanding of the mechanism of defect creation and elimination and has potential application in novel flexible strain sensors and switches.

ZnO-based ultraviolet photodetectors.

Ultraviolet (UV) photodetection has drawn a great deal of attention in recent years due to a wide range of civil and military applications. Because of its wide band gap, low cost, strong radiation hardness and high chemical stability, ZnO are regarded as one of the most promising candidates for UV photodetectors. Additionally, doping in ZnO with Mg elements can adjust the bandgap largely and make it feasible to prepare UV photodetectors with different cut-off wavelengths. ZnO-based photoconductors, Schottky photodiodes, metal-semiconductor-metal photodiodes and p-n junction photodetectors have been developed. In this work, it mainly focuses on the ZnO and ZnMgO films photodetectors. We analyze the performance of ZnO-based photodetectors, discussing recent achievements, and comparing the characteristics of the various photodetector structures developed to date.

Study of catalytic decomposition of formaldehyde on Pt/TiO2 alumite catalyst at ambient temperature.

Formaldehyde (HCHO) emitted from buildings, furnishing materials and consumer products is one of the most dominant volatile organic compounds (VOCs) in an indoor environment. In this work, a Pt/TiO(2)/Al(2)O(3) catalyst was prepared on an anodic alumite plate and was employed in the catalytic decomposition of formaldehyde at ambient temperature. Firstly, TiO(2) was deposited on the anodic alumite plate with electro-deposition technology. Then, platinum was supported on the anodic alumite plate with wet impregnation method. The developed catalyst exhibits good activity towards the decomposition of HCHO at ambient temperature. TPR (temperature programmed reduction) and TPD (temperature programmed desorption) analysis results indicate that oxygen adsorbed on the Pt/TiO(2)/Al(2)O(3) catalyst can be activated and generated to O:Pt(surface) species quickly at ambient temperature. Hence, the developed catalyst experiences the high activity towards the catalytic decomposition of formaldehyde at ambient temperature. Moreover, in accordance with the process requirements, the developed catalyst can be formed into various shapes such as a mesh, plate, fin, serrate etc., because aluminum can be formed into any shapes. The serrate type catalyst was prepared in this work and it also exhibits fine activity towards the decomposition of HCHO.

Catalytic oxidation of dichloromethane and toluene over platinum alumite catalyst.

Catalytic oxidation technology is one of the most promising technologies for the reduction of volatile organic compound (VOC) emissions. It is very necessary to study the catalytic oxidation of mixture of VOCs and volatile organic compounds (CVOCs), because VOCs are always emitted accompanying with CVOCs. Hence, the catalytic oxidation reaction of toluene and CH2Cl2 is explored on a platinum alumite catalyst in this work. The results show that the addition of toluene has no effect on the decomposition of CH2Cl2, although it can suppress CH3Cl formation because the steam generated from the catalytic combustion of toluene suppresses the formation of CH3Cl from CH2Cl2. High concentrations of CH2Cl2 have a negative effect on the catalytic combustion of toluene.

Effects of masticatory muscle force on temporomandibular joint disc growth in rats.

Biomechanical factors in masticatory function are related to the development of the mandible and the condyle. Previous studies have reported that reduced masticatory muscle force influences mandibular bone formation and chondroblastic proliferation. We examined the importance of compressive force in temporomandibular joint (TMJ) disc growth by reducing the masticatory load. Thirty 3-week-old male Wistar rats were used in this study. In the experimental group, the masseter muscles were bilaterally resected to evaluate the influence of masticatory muscle force on morphology and composition of TMJ disc during growth. No surgery was performed in the control group. The thickness of the TMJ disc was measured to evaluate the morphological changes. The localization of type I collagen and decorin was performed by immunostaining to examine compositional change. Cell proliferation in the disc was identified by insulin-like growth factor-1 receptor (IGF-1r) immunostaining. The disc thickness at each region in the experimental group was reduced compared to the control group. While in the control group, type I collagen and decorin were identified throughout the disc, it was concentrated on the superior portion of the disc at the anterior and posterior bands in the experimental group. The expression of IGF-1r immunopositive cells in the experimental group was also significantly lower than in the control. We conclude that masticatory muscle force is closely related to TMJ disc morphology and composition during growth.

Effect of plaque debulking before stent implantation on in-stent neointimal proliferation: a serial 3-dimensional intravascular ultrasound study.

BACKGROUND: Recent intravascular ultrasound (IVUS) studies have suggested that plaque burden has a role in promoting intimal hyperplasia after stenting. We report on volumetric assessments of in-stent neointimal formation with 3-dimensional IVUS analysis, comparing directional coronary atherectomy (DCA) plus stenting (DCA/stenting) to stenting without DCA. METHODS: Twenty-four patients (24 lesions) treated with DCA before stenting were matched to 24 patients (24 lesions) receiving stenting without DCA. All stents were a single Multilink stent. In both groups, serial IVUS was performed before and after intervention and during the 6-month follow-up period. The arterial segments that were analyzed with a computer-based contour detection program were the same as the stented segments analyzed on serial studies. These measurements were obtained: (1) lumen volume (LV), (2) stent volume (SV), (3) vessel volume (VV), (4) in-stent neointimal volume (ISV) calculated as SV-LV, and (5) percent in-stent neointimal volume (%ISV) calculated as ([SV-LV]/SV) x 100. RESULTS: Baseline characteristics of the 2 groups were similar. After intervention, both groups achieved similar LV (140.0 mm(3) DCA/stenting vs 135.2 mm(3) stenting alone). However, the follow-up ISV and %ISV were significantly smaller in the DCA/stenting group (19.6 +/- 12.2 mm(3) DCA/stenting vs 44.6 +/- 29.5 mm(3) stenting alone; P =.00040; 15.3% +/- 10.6% DCA/stenting vs 31.5% +/- 17.7% stenting alone; P =.00040). Consequently, the DCA/stenting group showed a significantly greater follow-up LV (121.0 +/- 51.5 mm(3) DCA/stenting vs 91.5 +/- 26.7 mm(3) stenting alone; P =.016). CONCLUSIONS: Plaque removal with DCA before stenting inhibits in-stent neointimal hyperplasia.

Coronary artery bypass grafting for a patient with Tangier disease.

A 56-year-old man with Tangier disease suffering from angina pectoris due to triple-vessel coronary artery disease evidenced extremely low blood high-density lipoprotein of 1 mg/dl, a specific laboratory indicator of this rare genetic disorder of lipid metabolism, considered to accompany juvenile arteriosclerosis. Because of the calcified ascending aorta, we conducted combined minimally invasive coronary artery bypass (CAB) for the left anterior descending coronary artery and percutaneous transluminal coronary angioplasty for other coronary artery lesions initially instead of conventional coronary artery bypass grafting. Angina recurred, however, due to refractory restenosis of the left circumflex coronary artery lesion. Two years later, we redid the CAB, grafting the free right internal thoracic artery from the functional left internal thoracic artery sequentially onto obtuse marginal and posterolateral coronary arteries. The patient returned to work angina-free.

Debulking and stenting versus debulking only of coronary artery disease in patients treated with cilostazol (final results of ESPRIT).

Stenting inhibits vascular constrictive remodeling after directional coronary atherectomy (DCA). Cilostazol has been reported to control neointimal proliferation after stenting. This study's aim was to examine the effect of debulking and stenting with antirestenotic medication on restenosis. After optimal DCA, 117 lesions were randomly assigned to either the DCA with stent (DCA-stent) (58 lesions) group or the DCA only (59 lesions) group. Multilink stents were implanted in the DCA-stent group. Cilostazol (200 mg/day) without aspirin was administered to both groups for 6 months. Ticlopidine (200 mg/day) was given to the DCA-stent group for 1 month. Serial quantitative angiography and intravascular ultrasound (IVUS) were performed at the time of the procedure and at 6-month follow-up. The primary end point was 6-month angiographic restenosis. Clinical event rates at 1 year were also assessed. Baseline characteristics were similar. All procedures were successful. No adverse effects to cilostazol were observed. Postprocedural lumen diameter was significantly larger (3.27 vs 2.92 mm; p <0.0001) in the DCA-stent group. However, the follow-up lumen diameter was not significantly different (2.53 vs 2.41 mm, DCA-stent vs DCA). IVUS revealed that intimal proliferation was significantly larger in the DCA-stent group (4.2 vs 1.5 mm(2); p <0.0001), which accounted for the similar follow-up lumen area (6.5 vs 7.1 mm(2)). The restenosis rate was low in both groups (5.4% vs 8.9%), and the difference was not significant. Clinical event rates at 1 year were also not significantly different. These results suggest that optimal lesion debulking by DCA does not always need adjunctive stenting if cilostazol is administered.