Spin squeezing and quantum correlations

We discuss the notion of spin squeezing considering two mutually exclusive classes of spin-s states, namely, oriented and non-oriented states. Our analysis shows that the oriented states are not squeezed while non-oriented states exhibit squeezing. We also present a new scheme for construction of spin-s states using 2s spinors oriented along different axes. Taking the case of s=1, we show that the ‘non-oriented’ nature and hence squeezing arise from the intrinsic quantum correlations that exist among the spinors in the coupled state.     

Sleep disturbances in highly stress reactive mice: Modeling endophenotypes of major depression

Background  

Neuronal mechanisms underlying affective disorders such as major depression (MD) are still poorly understood. By selectively breeding mice for high (HR), intermediate (IR), or low (LR) reactivity of the hypothalamic-pituitary-adrenocortical (HPA) axis, we recently established a new genetic animal model of extremes in stress reactivity (SR). Studies characterizing this SR mouse model on the behavioral, endocrine, and neurobiological levels revealed several similarities with key endophenotypes observed in MD patients. HR mice were shown to have changes in rhythmicity and sleep measures such as rapid eye movement sleep (REMS) and non-REM sleep (NREMS) as well as in slow wave activity, indicative of reduced sleep efficacy and increased REMS. In the present study we were interested in how far a detailed spectral analysis of several electroencephalogram (EEG) parameters, including relevant frequency bands, could reveal further alterations of sleep architecture in this animal model. Eight adult males of each of the three breeding lines were equipped with epidural EEG and intramuscular electromyogram (EMG) electrodes. After recovery, EEG and EMG recordings were performed for two days.     

Mercury speciation analysis on cell lines of the human central nervous system to explain genotoxic effects

A method for mercury speciation analysis on cell lines of the human central nervous system has been developed in order to study the intracellular mercury uptake and the distribution of mercury species. Glioblastoma (U373) and neuroblastoma (B103) human cell lines were exposed to different levels of monomethylmercury (MMHg). Mercury species were simultaneously extracted with tetramethylammonium hydroxide (TMAH) using a closed-vessel microwave system. The analysis was performed by ethylation and injection into a CGC-pyro-AFS system. An excellent procedural detection limit of 0.008 µM for MMHg was achieved. Recovery studies of cell extracts spiked with MMHg were done to check the reliability of the method and in all cases satisfactory recoveries (90-108%) were obtained. Remarkable differences between MMHg levels inside both human glioblastoma and neuroblastoma cell lines were found in initial experiments, which seem to be related to different genotoxic effects.     

Effects of lipopolysaccharide-induced inflammation on expression of growth-associated genes by corticospinal neurons

Background  

Inflammation around cell bodies of primary sensory neurons and retinal ganglion cells enhances expression of neuronal growth-associated genes and stimulates axonal regeneration. We have asked if inflammation would have similar effects on corticospinal neurons, which normally show little response to spinal cord injury. Lipopolysaccharide (LPS) was applied onto the pial surface of the motor cortex of adult rats with or without concomitant injury of the corticospinal tract at C4. Inflammation around corticospinal tract cell bodies in the motor cortex was assessed by immunohistochemistry for OX42 (a microglia and macrophage marker). Expression of growth-associated genes c-jun, ATF3, SCG10 and GAP-43 was investigated by immunohistochemistry or in situ hybridisation.     

Extractive Fermentation of Xylanase from Aspergillus tamarii URM 4634 in a Bioreactor

Of the many reported applications for xylanase, its use as a food supplement has played an important role for monogastric animals, because it can improve the utilisation of nutrients. The aim of this work was to produce xylanase by extractive fermentation in an aqueous two-phase system using Aspergillus tamarii URM 4634, increasing the scale of production in a bioreactor, partially characterising the xylanase and evaluating its influence on monogastric digestion in vitro. Through extractive fermentation in a bioreactor, xylanase was obtained with an activity of 331.4 U mL^?1 and 72 % yield. The xylanase was stable under variable pH and temperature conditions, and it was optimally active at pH 3.6 and 90 °C. Xylanase activity potentiated the simulation of complete monogastric digestion by 6 %, and only Mg²⁺ inhibited its activity. This process provides a system for efficient xylanase production by A. tamarii URM 4634 that has great potential for industrial use.     

Diagnosis of inflammatory lesions by high-wavenumber FT-Raman spectroscopy

The Raman spectroscopy technique has been extensively used for biological sample characterization. In particular, the fingerprint spectral region (800?C1,800?cm^?1) has been shown to be very promising for optical biopsy purposes. However, limitations for the widespread use of Raman-based optical biopsy technique still persist. For example, fluorescence when one uses visible light (400?C700?nm) spectral sources is often present and appears to affect the mid-IR/Raman region more than the high-wavenumber region (2,800?C3,600?cm^?1). But, both the higher wavenumber spectral region and the mid-IR/Raman region can be fluorescence-free when one uses lasers sources, which do not cause fluorescence, for example, 1,064, 830 or 785?nm sources. In addition, the Raman spectral signal of inflammatory infiltrates can influence the biopsy diagnoses and is one important source of misdiagnosis of normal versus pathological tissues. The present work seeks to evaluate whether the Raman spectra in the high-wavenumber spectral region can be used to distinguish between oral inflammatory fibrous hyperplasia (IFH) lesions and normal (NM) tissues and hence be used as a new diagnostic tool. Thirty spectra of oral IFH lesions and NM tissues from biopsies of 12 patients were analyzed using both principal components analysis (PCA) and a binary logistic regression (BLR) model. It was found that the high-wavenumber region Raman spectra can be used to discriminate between NM tissue and oral IFH tissues by analyzing the 2,800?C3,050?cm^?1 (CH₂ and CH₃ vibrations of lipids and proteins) and 3,050?C3,600?cm^?1 (CH, OH, and NH vibrations of proteins and water) spectral intensities. A simple classification model based on the relative areas of the above cited regions resulted in concordant pairs of 95.3%. Considering the standard errors in the model parameters, it was found that the sensitivity (Se) and specificity (Sp) fall in the interval 87%?<?Se?<?100% and 73%?<?Sp?<?93%, respectively. In addition, it has been found that the Raman scattering cross-sections in the NH, OH, and CH stretching region are more intense than in the mid-IR/Raman (fingerprint) region.     

Cellulase Production by Aspergillus japonicus URM5620 Using Waste from Castor Bean (Ricinus communis L.) Under Solid-State Fermentation

The activity of β-glucosidase (βG), total cellulase (FPase) and endoglucanase (CMCase), produced by Aspergillus japonicus URM5620, was studied on solid-state fermentation using castor bean meal as substrate. The effect of the substrate amount, initial moisture, pH, and temperature on cellulase production was studied using a full factorial design (2(4)). The maximum βG, FPase, and CMCase activity was 88.3, 953.4, and 191.6 U/g dry substrate, respectively. The best enzyme activities for all three enzymes were obtained at the same conditions with 5.0 g of substrate, initial moisture 15% at 25 °C and pH 6.0 with 120 h of fermentation. The optimum activity for FPase and CMCase was found at pH 3.0 at an optimum temperature of 50 °C for FPase and of 55 °C for CMCase. The cellulases were stable in the range of pH 3.0-10.0 at 50 °C temperature. The enzyme production optimization demonstrated clearly the impact of the process parameters on the yield of the cellulolytic enzymes.     

Photodamage in a Mitochondrial Membrane Model Modulated by the Topology of Cationic and Anionic Meso‐Tetrakis Porphyrin Free Bases

The photodynamic effects of the cationic TMPyP (meso‐tetrakis [N‐methyl‐4‐pyridyl]porphyrin) and the anionic TPPS4 (meso‐tetrakis[4‐sulfonatophenyl]porphyrin) against PC/CL phosphatidylcholine/cardiolipin (85/15%) membranes were probed to address the influence of phorphyrin binding on lipid damage. Electronic absorption spectroscopy and zeta potential measurements demonstrated that only TMPyP binds to PC/CL large unilamellar vesicles (LUVs). The photodamage after irradiation with visible light was analyzed by dosages of lipid peroxides (LOOH) and thiobarbituric reactive substance and by a contrast phase image of the giant unilamellar vesicles (GUVs). Damage to LUVs and GUVs promoted by TMPyP and TPPS4 were qualitatively and quantitatively different. The cationic porphyrin promoted damage more extensive and faster. The increase in LOOH was higher in the presence of D₂O, and was impaired by sodium azide and sorbic acid. The effect of D₂O was higher for TPPS4 as the photosensitizer. The use of DCFH demonstrated that liposomes prevent the photobleaching of TMPyP. The results are consistent with a more stable TMPyP that generates long‐lived singlet oxygen preferentially partitioned in the bilayer. Conversely, TPPS4 generates singlet oxygen in the bulk whose lifetime is increased in D₂O. Therefore, the affinity of the porphyrin to the membrane modulates the rate, type and degree of lipid damage.     

A combined experimental and theoretical approach for radical-scavenging activity of edaravone and its related derivatives

The experimental and theoretical study for evaluation of scavenging activity of edaravone (S1) and related derivatives, such as antipyrine (S2), dipyrone (S3), and phenylbutazone (S4), was carried out against DPPH and ABTS radicals. Structure–activity relationship study was performed using quantum chemical calculations at the DFT/B3LYP level of theory along with the 6-31G* basis sets. S1 and S4 are more effective scavengers against DPPH and ABTS. We observed little effects of S2 and S3 at several concentrations against these two free radicals. The calculations of HOMO, ionization potential, and bond dissociation energy confirmed that a hydrogen transfer is more preferential than an electron transfer. The radical stability of these compounds is related with spin densities. In accordance with experimental and theoretical results, edaravone is more active than phenylbutazone as scavenging drug.