A facile route for 3D aerogels from nanostructured 1D and 2D materials

Aerogels have numerous applications due to their high surface area and low densities. However, creating aerogels from a large variety of materials has remained an outstanding challenge. Here, we report a new methodology to enable aerogel production with a wide range of materials. The method is based on the assembly of anisotropic nano-objects (one-dimensional (1D) nanotubes, nanowires, or two-dimensional (2D) nanosheets) into a cross-linking network from their colloidal suspensions at the transition from the semi-dilute to the isotropic concentrated regime. The resultant aerogels have highly porous and ultrafine three-dimensional (3D) networks consisting of 1D (Ag, Si, MnO2, single-walled carbon nanotubes (SWNTs)) and 2D materials (MoS2, graphene, h-BN) with high surface areas, low densities, and high electrical conductivities. This method opens up a facile route for aerogel production with a wide variety of materials and tremendous opportunities for bio-scaffold, energy storage, thermoelectric, catalysis, and hydrogen storage applications.National Science Foundation (U.S.) (award number NSF DMR 0845358)MIT Energy InitiativeDouglas Spreng '65Massachusetts Institute of Technology. Institute for Soldier Nanotechnologie

Transparent, flexible supercapacitors from nano-engineered carbon films

Here we construct mechanically flexible and optically transparent thin film solid state supercapacitors by assembling nano-engineered carbon electrodes, prepared in porous templates, with morphology of interconnected arrays of complex shapes and porosity. The highly textured graphitic films act as electrode and current collector and integrated with solid polymer electrolyte, function as thin film supercapacitors. The nanostructured electrode morphology and the conformal electrolyte packaging provide enough energy and power density for the devices in addition to excellent mechanical flexibility and optical transparency, making it a unique design in various power delivery applications

Possible Room Temperature Ferromagnetism in Hydrogenated Carbon Nanotubes

We find that ferromagnetism can be induced in carbon nanotubes (CNTs) by introducing hydrogen. Multiwalled CNTs grown inside porous alumina templates contain a large density of defects resulting in significant hydrogen uptake when annealed at high temperatures. This hydrogen incorporation produces H-complex and adatom magnetism which generates a sizeable ferromagnetic moment and a Curie temperature near Tc=1000 K. We studied the conditions for the incorporation of hydrogen, the temperature-dependent magnetic behavior, and the dependence of the ferromagnetism on the size of the nanotubes.Comment: 15 pages with 3 figures included; Accepted by Phys. Rev.

Design of high SERS sensitive substrates based on branched Ti nanorods

Article reports a rational design of branched titanium (Ti) nanorods formed by glancing angle physical vapor deposition and their applications as substrates for surface-enhanced Raman scattering (SERS). The authors investigation provides a mechanism to fabricate sensitive SERS sensors of Ti nanorods that are known to be thermally and chemically stable and compatible with silicon-based electronics

Manufacturing and performance evaluation of carbon nanotube-parylene sandwich thin films

Parylene-C, an inert and relatively mechanically strong polymer, which can be deposited in a conformal manner, is a promising substrate candidate for flexible electronics (Flextronics) devices. Parylene-CNT sandwich-films were fabricated by utilizing single-walled carbon nanotube (SWNT) layers sandwiched between two, 10 μm thick parylene layers. The device was fabricated using shadow mask technology and SWNT drop casting on top of the Parylene substrate. The electrical conductivity and mechanical properties of the samples were tested under tensile loading. The load-unload tests showed small change in electrical resistance (~1%) when applying a strain in the range 0 - 2%, with negligible hysterisis. The tensile test also showed ~32% increase in the elastic modulus (E) of the sandwich film, relative to pure parylene. Potential applications are in interconnects for flexible electronics devices, and strain sensors for biological systems

Surgical Results of Endoscopic Dacryocystorhinostomy and Lacrimal Trephination in Distal or Common Canalicular Obstruction

ObjectivesTo evaluate the surgical outcomes of endoscopic dacryocystorhinostomy followed by canalicular trephination and silicone stenting in patients with distal or common canalicular obstructions.MethodsThe medical records of 29 patients (31 eyes) from January 2001 to December 2009 who underwent endoscopic dacryocystorhinostomy followed by canalicular trephination and silicone tube insertion for the treatment of distal or common canalicular obstructions were retrospectively reviewed. The level of obstruction was confirmed by intraoperative probing. The outcome of the surgery was categorized as a complete success, partial success, or failure according to the functional and anatomic patency.ResultsThe average age of the patients was 52 years. The duration of silicone intubation ranged from 4 to 11 months with an average of 5.7±1.6 months. The follow-up period after stent removal ranged from 4 to 15 months with an average of 8.2±3.3 months. Complete success was achieved in 25 out of 31 eyes (80.6%), partial success in 4 out of 31 eyes (12.9%), and failure in 2 out of 31 eyes (6.5%).ConclusionEndoscopic dacryocystorhinostomy followed by canalicular trephination and silicone stent intubation may be safe and considered as an initial treatment of patients with distal or common canalicular obstructions

Release of SOS2 kinase from sequestration with GIGANTEA determines salt tolerance in Arabidopsis

Kim, Woe-Yeon et al.--Environmental challenges to plants typically entail retardation of vegetative growth and delay or cessation of flowering. Here we report a link between the flowering time regulator, GIGANTEA (GI), and adaptation to salt stress that is mechanistically based on GI degradation under saline conditions, thus retarding flowering. GI, a switch in photoperiodicity and circadian clock control, and the SNF1-related protein kinase SOS2 functionally interact. In the absence of stress, the GI:SOS2 complex prevents SOS2- based activation of SOS1, the major plant Na+/H+-antiporter mediating adaptation to salinity. GI over-expressing, rapidly flowering, plants show enhanced salt sensitivity, whereas gi mutants exhibit enhanced salt tolerance and delayed flowering. Salt-induced degradation of GI confers salt tolerance by the release of the SOS2 kinase. The GISOS2 interaction introduces a higher order regulatory circuit that can explain in molecular terms, the long observed connection between floral transition and adaptive environmental stress tolerance in Arabidopsis.This research was supported by the Next-Generation BioGreen 21 Program (Systems and Synthetic Agrobiotech Center, no. PJ008025), a Cooperative Research Program for Agriculture Science & Technology Development (Project No. PJ007850), and the Ministry of Education, Science and Technology for the World Class University (WCU) program (R32-10148) from the Rural Development Administration, Republic of Korea, and by grant BIO2009-08641 financed by the Spanish Ministry of Science and Innovation and the FEDER program.Peer reviewe