Investigation of Different Gas Sensor-Based Artificial Olfactory Systems for Screening <Emphasis Type="Italic">Salmonella typhimurium</Emphasis> Contamination in Beef

Two different electronic nose systems (metal oxide and conducting polymer based) were used to identify Salmonella typhimurium contaminated beef strip loin samples (stored at two temperatures). The sensors present in the two systems were ranked based on their Fisher criteria of ranking to evaluate their importance in discriminant analysis. The most informative sensors were then used to develop linear discriminant analysis and quadratic discriminant analysis-based classification models. Further, sensor signals collected from both the sensor systems were combined to improve the classification accuracies. The developed models classified meat samples based on the Salmonella population into “No Salmonella” (microbial counts < 0.7 log₁₀ cfu/g) and “Salmonella inoculated” (microbial counts ≥ 0.7 log₁₀ cfu/g). The performances of the developed models were validated using leave-1-out cross-validation. Classification accuracies of 80% and above were observed for the samples stored at 10 °C using the sensor fusion approach. However, the classification accuracies were relatively low for the meat samples stored at 4 °C when compared to the samples stored at 10 °C. The results indicate that the electronic nose systems could be effectively used as a first stage screening device to identify the meat samples contaminated with S. typhimurium.     

Easy synthesis of nitrogen-doped graphene–silver nanoparticle hybrids by thermal treatment of graphite oxide with glycine and silver nitrate

Nitrogen-doped graphene–silver nanoparticle hybrids were prepared by thermal treatment of graphite oxide (GO) with glycine and silver nitrate at 500 °C. Glycine was used to reduce the nitrate ions, resulting in the decomposition of a glycine–nitrate mixture near 200 °C. The products of decomposition act as sources for nitrogen doping. The thermal treatment of a mixture of GO, glycine and silver nitrate results in the formation of silver nanoparticles at 100 °C, promotes the reduction of GO near 200 °C, and generates pyrrolic and pyridinic type nitrogen doping in graphene at 300 and 500 °C, respectively. The atomic percentage of nitrogen in as-prepared sample is about 13.5%. This approach opens up a new possibility for the synthesis of nitrogen-doped graphene decorated with various metallic nanoparticles, which could find important applications in the fields of energy storage and conversion devices.     

Long time behaviour of the solution of a system of equations from new theory of shock dynamics

The new theory of shock dynamics gives a system of n + 2 equations, the solution of which determines the propagation of a discontinuity in the initial condition. For the model equation u_t + u u_x = 0, the long time behaviour of the solution is investigated for various confined initial data. The suitability of using Padé approximants for the solution is examined. Special exact solutions are obtained.     

Comparison between measured and simulated shoreline changes near the tip of Indian peninsula

The coastline of Kannyakumari (8^°4^′N 77^°33^′E to 8^°13^′N 77^°14^′E), along the Arabian Sea is located near the southern tip of the Indian peninsula. This coast experiences heavy erosion particularly during the seasonal monsoons. This in turn results in considerable damage to properties, economic loss and leads to a number of socio economic problems. Protection measures in the form of groins have been implemented at selected locations along the coast. Prediction of shoreline oscillation due to the presence of such structures is extremely important prior to their construction. Although several formulae are available in the literature for the prediction of long shore sediment transport, studies regarding their application and validation with field problems along this coast are scanty. In the present work, seasonal measurements of shoreline oscillation adjacent to the shore connected structures were carried out during the year 2007 for which satellite data have also been adopted. These measurements are adopted to validate a finite difference based numerical model based on the formulation of Janardanan and Sundar (1994) for the prediction of shoreline evolution in the presence of shore connected structures. The offshore wave climate for the year 2007 is simulated from National Centre for Environmental Prediction (NCEP) wind data using Wave Analysis Model (WAM) model, whereas, the near shore wave climate was derived by adopting MIKE21 Parabolic Mild Slope (PMS) module The alongshore sediment transport is calculated using the approach of Van Rijn (2001). The prediction revealed that the net average annual alongshore transport varies from about 0.008 to 0.040 million m³ and is towards the west.     

Magnetism and magnetotransport in sonochemically-prepared amorphous Co(100-x)Pt(x) nanoalloys

Amorphous nanoalloys of Co(100-x)Pt(x) (0 < or = x < or = 50) prepared sonochemically exhibit a negative magnetotransport effect, showing a maximum for platinum volume fraction of 10%. The oscillatory peak maxima observed in x = 30 composition for residual resistivity, rho0 and Tmin corresponds to the peak minima for the negative MR% in the range of compositions studied. We observe that in weakly exchange coupled amorphous alloys, the local magnetic order at Tmin and the disorder effects observed from rho0 become crucial.     

Photovoltaic effect in single-layer organic solar cell devices fabricated with two new imidazolin-5-one molecules

Organic solar cells were fabricated with two new imidazolin-5-one molecules as active layers. The use of imidazolin-5-ones, derivatives of a biomolecule chromophore, for photovoltaic applications is particularly attractive due to its biodegradable nature and tunable properties. Single-layer devices with two analogues of imidazolin-5-ones were prepared and characterized. Devices fabricated with one of the molecules as the active layer showed a maximum J_sc of 0.52 μA cm⁻² and V_oc of 0.68 V at an incident power of 20.32 mW cm⁻², while the other set of devices showed a maximum J_sc of 0.63 μA cm⁻² and V_oc of 0.57 V at the same incident power.     

Fabrication of Ternary AgPdAu Alloy Nanoparticles on c-Plane Sapphire by the Systematical Control of Film Thickness and Deposition Sequence

Metallurgical and Materials Transactions A - In this work, a systematic study on the fabrication of ternary AgPdAu alloy nanoparticles (NPs) on c-plane sapphire (0001) is presented and the...     

Cytocompatible chitosan-graft-mPEG-based 5-fluorouracil-loaded polymeric nanoparticles for tumor-targeted drug delivery

Biodegradable materials like chitosan (CH) and methoxy polyethylene glycol (mPEG) are widely being used as drug delivery carriers for various therapeutic applications. In this study, copolymer (CH-g-mPEG) of CH and carboxylic acid terminated mPEG was synthesized by carbodiimide-mediated acid amine reaction. The resultant hydrophilic copolymer was characterized by Fourier transform infrared spectroscopy and ¹H NMR studies, revealing its relevant functional bands and proton peaks, respectively. Blank polymeric nanoparticles (B-PNPs) and 5-fluorouracil loaded polymeric nanoparticles (5-FU-PNPs) were formulated by ionic gelation method. Furthermore, folic acid functionalized FA-PNPs and FA-5-FU-PNPs were prepared for folate receptor-targeted drug delivery. FA-5-FU-PNPs were characterized by particle size, zeta potential, and in vitro drug release studies, resulting in 197.7?nm,?+29.9?mv, and sustained drug release of 88% in 24?h, respectively. Cytotoxicity studies were performed for FA-PNPs and FA-5-FU-PNPs in MCF-7 cell line, which exhibited a cell viability of 80 and 41%, respectively. In vitro internalization studies were carried out for 5-FU-PNPs and FA-5-FU-PNPs which demonstrated increased cellular uptake of FA-5-FU-PNPs by receptor-mediated transport. Significant (p?相似文献   

Neurochemicals measured by 1H-MR spectroscopy: putative vulnerability biomarkers for obsessive compulsive disorder

Object

Obsessive compulsive disorder (OCD) is the fourth most common psychiatric disorder characterized by recurrent, intrusive thoughts and repetitive, ritualistic behaviors that are debilitating to the patient. Despite its high prevalence and the attendant morbidity, the pathophysiology of OCD remains unclear. Magnetic resonance spectroscopy (MRS) provides a noninvasive method to characterize the molecular biochemistry that may contribute to the pathophysiology of OCD. This study aimed to identify alterations in neurochemical measures that are specific to OCD using in vivo proton (¹H) MRS of the caudate nucleus, anterior cingulate cortex, and medial thalamus in these patients, and to identify their role as vulnerability markers by comparing them with the healthy first degree relatives of these patients and healthy controls.

Materials and methods

Appropriate psychometric instruments were applied in the study population followed by ¹H- MRS. The absolute neurochemical measures were quantified using a linear combination model.

Results

Significant differences in neurochemical measures were demonstrated in two of the three candidate regions (except the medial thalamus) between the three study groups.

Conclusions

Our results lend support to the neurodegenerative hypothesis of OCD, and also raise the possibility of exploring these neurochemical measures (as measured by MRS) as putative vulnerability biomarkers in OCD that may aid in early identification and devising early prevention or management strategies for the population vulnerable to OCD.