One-dimensional hydrogen atom with minimal length uncertainty and maximal momentum

We present exact energy eigenvalues and eigenfunctions of the one-dimensional hydrogen atom in the framework of the Generalized (Gravitational) Uncertainty Principle (GUP). This form of GUP is consistent with various theories of quantum gravity such as string theory, loop quantum gravity, black-hole physics, and doubly special relativity and implies a minimal length uncertainty and a maximal momentum. We show that the quantized energy spectrum exactly agrees with the semiclassical results.Comment: 10 pages, 1 figur

Optimization of a Modified GS Medium for a Probiotic Strain (L. acidophilus ATCC4356)

Probiotics are defined as living microorganisms with beneficial effects on the host. Probiotics, according to the least negative effect on the body, are considered as a good alternative to chemical drugs. Lactobacillus acidophilus is used as a probiotic that is able to reduce cholesterol level in the blood. The effect of various concentrations of carbon, nitrogen and phosphorus for enhancing the biomass production of Lactobacillus acidophilus was examined. The response surface methodology based on Box–Wilson CCD was applied to explore the optimal medium composition. Glucose, yeast extract, K2HPO4 and KH2PO4 were selected as dependent variables. All experiments were run at 37°C for 31h under stationary conditions. By solving the regression equation and analyzing the response surface carton, optimal concentrations of the components were determined as glucose (5-8.75 g.l-1), yeast extract (36.75-39 g.l-1), K2HPO4 (0.1-0.2125 g.l-1) and KH2PO4 (0.3925-0.7075 g.l-1). Validation experiment confirmed that the optimized medium was comparable to the MRS medium (the most common medium for Lactobacillus acidophilus strain) in biomass production, having the advantages of economy andpracticality

Quantum Stephani exact cosmological solutions and the selection of time variable

We study perfect fluid Stephani quantum cosmological model. In the present work the Schutz's variational formalism which recovers the notion of time is applied. This gives rise to Wheeler-DeWitt equation for the scale factor. We use the eigenfunctions in order to construct wave packets for each case. We study the time-dependent behavior of the expectation value of the scale factor, using many-worlds and deBroglie-Bohm interpretations of quantum mechanics.Comment: 19 pages, 7 figure

Quantum Stephani Universe in vicinity of the symmetry center

We study a class of spherically symmetric Stephani cosmological models in the presence of a self-interacting scalar field in both classical and quantum domains. We discuss the construction of `canonical' wave packets resulting from the solutions of a class of Wheeler-DeWitt equations in the Stephani Universe. We suggest appropriate initial conditions which result in wave packets containing some desirable properties, most importantly good classical and quantum correspondence. We also study the situation from de-Broglie Bohm interpretation of quantum mechanics to recover the notion of time and compare the classical and Bohmian results. We exhibit that the usage of the canonical prescription and appropriate choices of expansion coefficients result in the suppression of the quantum potential and coincidence between classical and Bohmian results. We show that, in some cases, contrary to Friedmann-Robertson-Walker case, the bound state solutions also exist for all positive values of the cosmological constant.Comment: 22 pages, 19 figures, to appear in JCA

An EGFR Targeted PET Imaging Probe for the Detection of Colonic Adenocarcinomas in the Setting of Colitis

Colorectal cancer is a serious complication associated with inflammatory bowel disease, often indistinguishable by screening with conventional FDG PET probes. We have developed an alternative EGFR-targeted PET imaging probe that may be used to overcome this difficulty, and successfully assessed its utility for neoplastic lesion detection in preclinical models. Cetuximab F(ab′)2 fragments were enzymatically generated, purified, and DOTA-conjugated. Radiolabeling was performed with 67Ga for cell based studies and 64Cu for in vivo imaging. Competitive binding studies were performed on CT26 cells to assess affinity (KD) and receptors per cell (Bmax). In vivo imaging using the EGFR targeted PET probe and 18F FDG was performed on CT26 tumor bearing mice in both control and dextran sodium sulfate (DSS) induced colitis settings. Spontaneous adenomas in genetically engineered mouse (GEM) models of colon cancer were additionally imaged. The EGFR imaging agent was generated with high purity (> 98%), with a labeling efficiency of 60 ± 5% and ≥99% radiochemical purity. The KD was 6.6 ± 0.7 nM and the Bmax for CT26 cells was 3.3 ± 0.1 × 106 receptors/cell. Target to background ratios (TBR) for CT26 tumors compared to colonic uptake demonstrated high values for both 18F-FDG (3.95 ± 0.13) and the developed 64Cu-DOTA-cetuximab-F(ab′)2 probe (4.42 ± 0.11) in control mice. The TBR for the EGFR targeted probe remained high (3.78 ± 0.06) in the setting of colitis, while for 18F FDG, this was markedly reduced (1.54 ± 0.08). Assessment of the EGFR targeted probe in the GEM models demonstrated a correlation between radiotracer uptake in spontaneous colonic lesions and the EGFR staining level ex vivo. A clinically translatable PET imaging probe was successfully developed to assess EGFR. The imaging agent can detect colonic tumors with a high TBR for detection of in situ lesions in the setting of colitis, and opens the possibility for a new approach for screening high-risk patients

Generalized Uncertainty Principle, Modified Dispersion Relation and Barrier penetration by a Dirac particle

We have studied the energy band structure of a Dirac particle in presence of a generalised uncertainty principle (GUP). We start from defining a modified momentum operator and derive corresponding modified dispersion relation (MDR) and GUP. Apart from the forbidden band within the range $\pm m$, $m$ being the mass of the particle, we find the existence of additional forbidden bands at the both ends of the spectrum. Such band structure forbids a Dirac particle to penetrate a potential step of sufficient height ($\sim E_P$, $E_P$ being Planck energy). This is also true for massless particle. Unlike the relativistic case, a massless particle also can reflect from a barrier of sufficient height. Finally we discuss about the Klein's paradox in presence of the GUP.Comment: 10 pages, 7 figures, LaTe

Definition of Spam 2.0: New Spamming Boom

The most widely recognized form of spam is e-mail spam, however the term “spam” is used to describe similarabuses in other media and mediums. Spam 2.0 (or Web 2.0 Spam) is refereed to as spam content that is hosted on online Web 2.0 applications. In this paper: we provide a definition of Spam 2.0, identify and explain different entities within Spam 2.0, discuss new difficulties associated with Spam 2.0, outline its significance, and list possible countermeasure. The aim of this paper is to provide the reader with a complete understanding of this new form of spamming

Field-effect mobility extraction in nanowire field-effect transistors by combination of transfer characteristics and random telegraph noise measurements

A technique based on the combined measurements of random telegraph-signal noise amplitude and drain current vs. gate voltage characteristics is proposed to extract the channel mobility in inversion-mode and accumulation-mode nanowire transistors. This method does not require the preliminary knowledge of the gate oxide capacitance or that of the channel width. The method accounts for the presence of parasitic source and drain resistance effect. It has been used to extract the zero-field mobility and the field mobility reduction factor in inversion-mode and junctionless transistors operating in accumulation mode. (C) 2011 American Institute of Physics. (doi:10.1063/1.3626038

Random telegraph-signal noise in junctionless transistors

Random telegraph-signal noise (RTN) is measured in junctionless metal-oxide-silicon field-effect transistors (JL MOSFETs) as a function of gate and drain voltage and temperature. It is shown that the RTN in JL MOSFETs increases significantly when an accumulation layer is formed. The amplitude of RTN is considerably smaller in JL devices than in inversion-mode MOSFET fabricated using similar fabrication parameters. A measurement technique is developed to extract the main parameters of the traps, including the average charge capture and emission time from the traps. (C) 2011 American Institute of Physics. (doi:10.1063/1.3557505

Study of antioxidant activity and free radical scavenging power of Physalis alkekengi flower extract

According to the undesirable effects of many chemical preservatives in food products such as oilseed extraction industry, the possibility of substituting these materials with effective compounds of herbal plants have been considered by the researchers. In this study, at first, the Physalis Alkekengi flower extract was extracted by using maceration method with methanol. The Phenolic compounds and the amount of free radical scavenging activity of the flower extract were investigated in different concentrations (200, 400, 600, 800 and 1000 ppm), respectively by Folin–Ciocalteu method and DPPH test and were compared with the synthetic antioxidant activity (BHT) at 200 ppm. The results showed a significant difference between different concentrations of Physalis Alkekengi flower extract, in terms of the rate of Phenolic compounds and free radical scavenging activity of flower extract (p < 0.05). In general, the results of this study showed that the methanol extract of Physalis Alkekengi flower, as a source of cheap and available natural antioxidant, after conducting supplementary experiments can be used in food industry.Keywords: Physalis Alkekengi flower, Free radical scavenging power, Natural antioxidants,Phenolic compounds