Publications by authors named "Gruner G"

Background: Nuclear envelope proteins play an important role in the pathogenesis of hereditary cardiomyopathies. Recently, a new form of arrhythmic cardiomyopathy caused by a homozygous mutation (p.L13R) in the inner nuclear membrane protein LEMD2 was discovered.

View Article and Find Full Text PDF

Atrial fibrillation is the most common cardiac arrhythmia and symptoms overlap with physiological sensations of anxiety. Patients with atrial fibrillation can demonstrate anxiety sensitivity even in the absence of actual atrial fibrillation symptoms. Interoceptive exposure is effective in treating anxiety sensitivity, and recently, mindfulness has been proposed as an enhancement strategy to facilitating inhibitory learning in exposure therapy.

View Article and Find Full Text PDF

A new method to enhance the stability of quantum dots (QDs) in aqueous solution by encapsulating them with conducting polymer polyaniline was reported. The polyaniline-encapsulated QDs were then decorated onto graphene through π-π interactions between graphene and conjugated polymer shell of QDs, forming stable polyaniline/QD/graphene hybrid. A testing electronic device was fabricated using the hybrid in order to investigate the photoinduced charge transfer between graphene and encapsulated QDs within the hybrid.

View Article and Find Full Text PDF

Graphene, as a rising star in the field of nanomaterials, possesses a unique planar structure and exceptional electronic, mechanical, and optical properties. The material has attracted tremendous interest not only for its intrinsic properties but also promising application opportunities in a wide range of technologies and markets. This review specifically summarizes recent research advancements of graphene in the areas of biotechnology and biomedicine.

View Article and Find Full Text PDF

Background: Semiconductor doped nanostructure materials have attained considerable attention owing to their electronic, opto-electronic, para-magnetic, photo-catalysis, electro-chemical, mechanical behaviors and their potential applications in different research areas. Doped nanomaterials might be a promising owing to their high-specific surface-area, low-resistances, high-catalytic activity, attractive electro-chemical and optical properties. Nanomaterials are also scientifically significant transition metal-doped nanostructure materials owing to their extraordinary mechanical, optical, electrical, electronic, thermal, and magnetic characteristics.

View Article and Find Full Text PDF

We study in detail here the application of transparent, conductive carbon single-wall nanotube (SWNT) networks as electrodes in flexible organic light-emitting diodes (FOLEDs). Overall comparisons of these networks to the commonly used electrodes poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and indium tin oxide (ITO) are made, and SWNT networks are shown to have excellent optical and superior mechanical properties. The effects of protruding nanotubes, rough surface morphology, and SWNT network-adjacent layer dewetting are shown to be problematic, and approaches for addressing these issues are identified.

View Article and Find Full Text PDF

We report a method of fabrication of free standing and ultra-thin carbon nanotube-parylene-C interpenetrating networks. The network is highly transparent, highly flexible, and more conductive than transparent nanotube/polymer composites. Scanning electron microscope imaging reveals that the interpenetrated networks are dense and pinhole free compared to bare nanotube networks.

View Article and Find Full Text PDF

In this work, we reported high performance OLED devices with transparent and conductive carbon nanotube anodes after modification. The modifications include IMRE proprietary PEDOT:PSS composite top coating (PS(C)), concentrated HNO(3) acid soaking, and polymer encapsulation. For PS(C)-modified nanotube thin film anode, we achieved maximum luminescence of approximately 9000 cd/m(2), close to ITO-based OLED device performance, and high efficiency of approximately 10 cd/A, similar with ITO-based OLED device.

View Article and Find Full Text PDF

Thin film supercapacitors were fabricated using printable materials to make flexible devices on plastic. The active electrodes were made from sprayed networks of single-walled carbon nanotubes (SWCNTs) serving as both electrodes and charge collectors. Using a printable aqueous gel electrolyte as well as an organic liquid electrolyte, the performances of the devices show very high energy and power densities (6 W h/kg for both electrolytes and 23 and 70 kW/kg for aqueous gel electrolyte and organic electrolyte, respectively) which is comparable to performance in other SWCNT-based supercapacitor devices fabricated using different methods.

View Article and Find Full Text PDF

Carbon nanotube network field effect transistors (CNTN-FETs) are promising candidates for low cost macroelectronics. We investigate the microscopic transport in these devices using electric force microscopy and simulations. We find that in many CNTN-FETs the voltage drops abruptly at a point in the channel where the current is constricted to just one tube.

View Article and Find Full Text PDF

A pyrene-modified beta-cyclodextrin (pyrenecyclodextrin)-decorated single-walled carbon nanotube (SWNT) field-effect transistor (FET) device was fabricated, which can serve as a tunable photosensor to sense a fluorescent adamantyl-modified Ru complex (ADA-Ru). When the light is on (I = 40 W m(-2) and lambda = 280 nm), the transfer curve of the pyrenecyclodextrin-SWNT/FET device shifts toward a negative gate voltage by about 1.6 V and its sheet resistance increases quickly, indicating a charge-transfer process from the pyrenecyclodextrins to the SWNTs.

View Article and Find Full Text PDF

Single-walled carbon nanotube (SWNT) films on flexible PET (polyethyleneterephthalate) substrates are used as transparent, flexible anodes for organic light-emitting diodes (OLEDs). For polymer-based OLEDs having the structure: SWNT/PEDOT-PSS:MeOH/TFB (poly(9,9-dioctylfluorene-co-N-(4-butylphenyl)diphenylamine)) + TPD-Si(2) (4,4'-bis[(p-trichlorosilylpropylphenyl)phenylamino]biphenyl) /BT (poly(9,9-dioctylfluorene-co-benzothiadiazole))/CsF/Al, a maximum light output of 3500 cd/m(2) and a current efficiency of 1.6 cd/A have been achieved.

View Article and Find Full Text PDF

Single-wall carbon nanotube (SWNT) field effect transistors (FETs), functionalized noncovalently with a zinc porphyrin derivative, were used to directly detect a photoinduced electron transfer (PET) within a donor/acceptor (D/A) system. We report here that the SWNTs act as the electron donor and the porphyrin molecules as the electron acceptor. The magnitude of the PET was measured to be a function of both the wavelength and intensity of applied light, with a maximum value of 0.

View Article and Find Full Text PDF

Electronic detection of biomolecules, although still in its early stages, is gradually emerging as an effective alternative to optical detection methods. We describe field effect transistor devices with carbon nanotube conducting channels that have been developed and used for biosensing and biodetection. Both transistors with single carbon nanotube conducting channels and devices with nanotube network conducting channels have been fabricated and their electronic characteristics examined.

View Article and Find Full Text PDF

We report the integration of a complex biological system and a nanoelectronic device, demonstrating that both components retain their functionality while interacting with each other. As the biological system, we use the cell membrane of Halobacterium salinarum. As the nanoelectronic device, we use a nanotube network transistor, which incorporates many individual nanotubes in such a way that entire patches of cell membrane are contacted by nanotubes.

View Article and Find Full Text PDF

We report the fabrication of transparent and flexible transistors where both the bottom gate and the conducting channel are carbon nanotube networks of different densities and Parylene N is the gate insulator. Device mobilities of 1 cm(2) V(-1) s(-1) and on/off ratios of 100 are obtained, with the latter influenced by the properties of the insulating layer. Repetitive bending has minor influence on the characteristics, with full recovery after repeated bending.

View Article and Find Full Text PDF

[reaction: see text] The enzymatic degradation of starch can be monitored electronically using single-walled carbon nanotubes (SWNTs) as semiconducting probes in field-effect transistors (FETs). Incubation of these devices in aqueous buffer solutions of amyloglucosidase (AMG) results in the removal of the starch from both the silicon surfaces and the side walls of the SWNTs in the FETs, as evidenced by direct imaging and electronic measurements.

View Article and Find Full Text PDF

We report the use of nanotube field-effect transistor devices for chemical sensing in a conducting liquid environment. Detection of ammonia occurs through the shift of the gate voltage dependence of the source-drain current. We attribute this shift to charge transfer from adsorbed ammonia molecules, with the amount of charge estimated to be as small as 40 electrons for the smallest shift detected.

View Article and Find Full Text PDF

Measurements of the complex frequency dependent conductivity of uncompensated n-type silicon are reported. The experiments are done in the quantum limit, variant Planck's over 2pi omega>k(B)T, across a broad doping range on the insulating side of the metal-insulator transition. The low energy linear frequency dependence is consistent with theories of a Coulomb glass, but discrepancies exist in the relative magnitudes of the complex components.

View Article and Find Full Text PDF

The optical conductivity of the heavy fermions UPd(2)Al(3) and UPt(3) has been measured in the energy range from 0.04 to 5 meV. In both compounds a well pronounced pseudogap of less than 1 meV develops in the optical response at low temperatures; we relate this to the antiferromagnetic ordering.

View Article and Find Full Text PDF

We have conducted temperature and frequency dependent transport measurements in amorphous NbxSi1-x samples in the insulating regime. We find a temperature dependent dc conductivity consistent with variable range hopping in a Coulomb glass. The frequency dependent response in the millimeter-wave frequency range can be described by the expression sigma(omega) varies with (-iota omega)(alpha) with the exponent somewhat smaller than 1.

View Article and Find Full Text PDF

We propose a model Hamiltonian for charge transfer along the DNA double helix with temperature-driven fluctuations in the base pair positions acting as the rate limiting factor for charge transfer between neighboring base pairs. We compare the predictions of the model with the recent work of Barton and Zewail on the unusual two-stage charge transfer of DNA.

View Article and Find Full Text PDF