A sputtered thin film of nanostructured Ni/Pt/Ti on Al2O3 substrate for ethanol sensing

A novel thin film ethanol sensor using sputtered Ni/Pt/Ti on an Al2O3 substrate as the working electrode in an alkaline solution was developed. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to characterize the nanostructure of nickel films. Sputtering deposition conditions for maximum catalytic efficiency, electrode selectivity, and reproducibility were discussed. The results showed that ethanol oxidation was more efficient on the sputtered Ni/Pt/Ti on an Al2O3 substrate electrode than that on the conventional nickel electrode. The optimal operating conditions to generate the sputtered Ni/Pt/Ti on the Al2O3 substrate electrode were: 45 min of Ni sputtering deposition time, and 50 W of Ni sputtering power. The results also indicated that the response time of the prepared ethanol sensor is 27 s and the best sensitivity is 3.08 microA microM(-1) cm(-2).     

The molecular basis of spinocerebellar ataxia type 48 caused by a de novo mutation in the ubiquitin ligase CHIP

The spinocerebellar ataxias (SCAs) are a class of incurable diseases characterized by degeneration of the cerebellum that results in movement disorder. Recently, a new heritable form of SCA, spinocerebellar ataxia type 48 (SCA48), was attributed to dominant mutations in STIP1 homology and U box-containing 1 (STUB1); however, little is known about how these mutations cause SCA48. STUB1 encodes for the protein C terminus of Hsc70 interacting protein (CHIP), an E3 ubiquitin ligase. CHIP is known to regulate proteostasis by recruiting chaperones via a N-terminal tetratricopeptide repeat domain and recruiting E2 ubiquitin-conjugating enzymes via a C-terminal U-box domain. These interactions allow CHIP to mediate the ubiquitination of chaperone-bound, misfolded proteins to promote their degradation via the proteasome. Here we have identified a novel, de novo mutation in STUB1 in a patient with SCA48 encoding for an A52G point mutation in the tetratricopeptide repeat domain of CHIP. Utilizing an array of biophysical, biochemical, and cellular assays, we demonstrate that the CHIP^A52G point mutant retains E3-ligase activity but has decreased affinity for chaperones. We further show that this mutant decreases cellular fitness in response to certain cellular stressors and induces neurodegeneration in a transgenic Caenorhabditis elegans model of SCA48. Together, our data identify the A52G mutant as a cause of SCA48 and provide molecular insight into how mutations in STUB1 cause SCA48.     

Frequent Unanticipated Alleles of lethal giant larvae in Drosophila Second Chromosome Stocks

Forty years ago, a high frequency of lethal giant larvae (lgl) alleles in wild populations of Drosophila melanogaster was reported. This locus has been intensively studied for its roles in epithelial polarity, asymmetric neural divisions, and restriction of tissue proliferation. Here, we identify a high frequency of lgl alleles in the Bloomington second chromosome deficiency kit and the University of California at Los Angeles Bruinfly FRT40A-lethal P collection. These unrecognized aberrations confound the use of these workhorse collections for phenotypic screening or genetic mapping. In addition, we determined that independent alleles of insensitive, reported to affect asymmetric cell divisions during sensory organ development, carry lgl deletions that are responsible for the observed phenotypes. Taken together, these results encourage the routine testing of second chromosome stocks for second-site alleles of lgl.     

Absence of radiofrequency heating from auditory implants during magnetic resonance imaging

The possibility of tissue heating due to an auditory brainstem implant (ABI) or a modified cochlear implant (CI) during magnetic resonance imaging (MRI) of the head was tested on a full-sized human phantom using a realistic phantom head consisting of simulated skull, brain, and muscle. Dielectric properties of the brain, muscle, and bone materials were similar to those of human tissues at 64 MHz. The body consisted of homogeneous phantom muscle enclosed in a human-shaped fiberglass shell. Thermographic and fiber-optic temperature measurements were conducted to reveal any heating. Thermograms of sagittal, frontal, and horizontal planes of the head with the ABI and CI electrodes were taken immediately before and after a 26 min MRI scan. The MRI sequence was set at 94 excitations and 25 ms echo time to induce maximum radiofrequency heating, as suggested by the General Electric Company. The difference of these two thermograms gives the heating results. In two uncut phantom heads, Teflon tubes were placed along the implanted ABI and CI, and temperature data were recorded via fiber-optic probes before, during, and after the MRI. Results showed no observable heating associated with the ABI and the modified CI during worst-case MRI of the head. © 1995 Wiley-Liss, Inc.     

Image Corruption Detection in Diffusion Tensor Imaging for Post-Processing and Real-Time Monitoring

Due to the high sensitivity of diffusion tensor imaging (DTI) to physiological motion, clinical DTI scans often suffer a significant amount of artifacts. Tensor-fitting-based, post-processing outlier rejection is often used to reduce the influence of motion artifacts. Although it is an effective approach, when there are multiple corrupted data, this method may no longer correctly identify and reject the corrupted data. In this paper, we introduce a new criterion called “corrected Inter-Slice Intensity Discontinuity” (cISID) to detect motion-induced artifacts. We compared the performance of algorithms using cISID and other existing methods with regard to artifact detection. The experimental results show that the integration of cISID into fitting-based methods significantly improves the retrospective detection performance at post-processing analysis. The performance of the cISID criterion, if used alone, was inferior to the fitting-based methods, but cISID could effectively identify severely corrupted images with a rapid calculation time. In the second part of this paper, an outlier rejection scheme was implemented on a scanner for real-time monitoring of image quality and reacquisition of the corrupted data. The real-time monitoring, based on cISID and followed by post-processing, fitting-based outlier rejection, could provide a robust environment for routine DTI studies.     

Epinephrine-induced pigment aggregation in goldfish melanophoroma cells: apparent involvement of an unknown second messenger

Using a goldfish-derived melanized cell line, we attempted to determine the identity of the signal transduction system/second messenger for epinephrine-induced aggregation of melanosomes in a goldfish cell line. The results show that the second messenger is unknown. It is not 1) influx of extracellular calcium, 2) release of intracellular stored calcium via the phosphoinositide pathway, 3) cGMP, or 4) decrease of cAMP. These results suggest that there is an unknown second messenger for this activity of epinephrine.     

A Two-Level Computation Model Based on Deep Learning Algorithm for Identification of piRNA and Their Functions via Chou’s 5-Steps Rule

International Journal of Peptide Research and Therapeutics - Piwi interacting RNA (piRNA) molecules belong to a largest class of small non coding RNA molecules which are originally discovered in...