1,463 research outputs found
Bioprospecting and molecular characterization of laccase producing bacteriafrom industrial contaminated sites
Laccases have vast prospective for biotechnological applications due to their outstanding bioremediation potential. These include abundant applications in effluent detoxification, enzymatic conversion of chemical intermediates, wine clarification degradation of textile dyes etc. In the present study, two potential microbes were isolated on solid medium containing guaiacol and ABTS for laccase activity out of 10 microbes. Two cultures PHP7 and PKD5 were selected for molecular characterization was carried out using 16S rRNA gene technology of PHP7 revealed as Bacillus cereus (KU878970.1).Partial amplification of laccase gene contain conserved domain of multicopper oxidase family. The biomass produced by PHP7 was 0.053 mg/5 mL, while PKD5 was 0.058 mg/5 mL. While dye degradation of PHP7dye of 64.28% after incubation of 6 days at pH7 whereas PKD5 shows highest degradation of dye i.e. 61.90% after incubation of 8 days at pH8. PHP7 showed highest Laccase activity of 0.489 U/L at pH 7 while PKD5 showed 0.404 U/L Laccase activity at pH 8 at 8th day of incubation. Using laccase from PHP7 and PKD5 isolates, explored at industrial level for decolorization of coloured effluents that significance in environmentally friendly and play critical role as bioremediation at commercial scale
Analytical time-like geodesics
Time-like orbits in Schwarzschild space-time are presented and classified in
a very transparent and straightforward way into four types. The analytical
solutions to orbit, time, and proper time equations are given for all orbit
types in the form r=r(\lambda), t=t(\chi), and \tau=\tau(\chi), where \lambda\
is the true anomaly and \chi\ is a parameter along the orbit. A very simple
relation between \lambda\ and \chi\ is also shown. These solutions are very
useful for modeling temporal evolution of transient phenomena near black holes
since they are expressed with Jacobi elliptic functions and elliptic integrals,
which can be calculated very efficiently and accurately.Comment: 15 pages, 10 figures, accepted by General Relativity and Gravitatio
Enhanced expression of fibroblast growth factors and receptor FGFR-1 during vascular remodeling in chronic obstructive pulmonary disease
Important characteristics of chronic obstructive pulmonary disease (COPD)
include airway and vascular remodeling, the molecular mechanisms of which
are poorly understood. We assessed the role of fibroblast growth factors
(FGF) in pulmonary vascular remodeling by examining the expression pattern
of FGF-1, FGF-2, and the FGF receptor (FGFR-1) in peripheral area of lung
tissues from patients with COPD (FEV(1) < or = 75%; n = 15) and without
COPD (FEV(1) > or = 85%; n = 13). Immunohistochemical staining results
were evaluated by digital video image analysis as well as by manual
scoring. FGF-1 and FGFR-1 were detected in vascular smooth muscle (VSM),
airway smooth muscle, and airway epithelial cells. FGF-2 was localized in
the cytoplasm of airway epithelium and in the nuclei of airway smooth
muscle, VSM, and endothelial cells. In COPD cases, an unequivocal increase
in FGF-2 expression was observed in VSM (3-fold, P = 0.001) and
endothelium (2-fold, P = 0.007) of small pulmonary vessels with a luminal
diameter under 200 micro m. In addition, FGFR-1 levels were elevated in
the intima (1.5-fold, P = 0.05). VSM cells of large (> 200 micro m)
pulmonary vessels showed increased staining for FGF-1 (1.6-fold, P < 0.03)
and FGFR-1 (1.4-fold, P < 0.04) in COPD. Pulmonary vascular remodeling,
assessed as the ratio of alpha-smooth muscle actin staining and vascular
wall area with the lumen diameter, was increased in large vessels of
patients with COPD (P = 0.007) and was inversely correlated with FEV(1)
values (P < 0.007). Our results suggest an autocrine role of the
FGF-FGFR-1 system in the pathogenesis of COPD-associated vascular
remodeling
Neutron Stars and Nuclei in the Modified Relativistic Hartree Approximation
We have examined the properties of neutron-rich matter and finite nuclei in
the modified relativistic Hartree approximation for several values of the
renormalization scale, , around the standard choice of equal to the
nucleon mass . Observed neutron star masses do not effectively constrain the
value of . However for finite nuclei the value , suggested by
nuclear matter data, provides a good account of the bulk properties with a
sigma mass of about 600 MeV. This value of renders the effective three
and four body scalar self-couplings to be zero at 60\% of equilibrium nuclear
matter density, rather than in the vacuum. We have also found that the matter
part of the exchange diagram has little impact on the bulk properties of
neutron stars.Comment: 33 pages, Latex, 8 figures (available from authors by fax), Minnesota
preprint NUC-MINN-93/7-
Pumping current of a Luttinger liquid with finite length
We study transport properties in a Tomonaga-Luttinger liquid in the presence
of two time-dependent point like weak impurities, taking into account
finite-length effects. By employing analytical methods and performing a
perturbation theory, we compute the backscattering pumping current (I_bs) in
different regimes which can be established in relation to the oscillatory
frequency of the impurities and to the frequency related to the length and the
renormalized velocity (by the electron-electron interactions) of the charge
density modes. We investigate the role played by the spatial position of the
impurity potentials. We also show how the previous infinite length results for
I_bs are modified by the finite size of the system.Comment: 9 pages, 7 figure
Entanglement generation and transfer between remote atomic qubits interacting with squeezed field
A pair of two level atoms A1A2, prepared either in a separable state or in an
entangled state, interacts with a single mode of two mode squeezed cavity field
while a third atomic qubit B interacts with the second mode of the squeezed
field in a remote cavity. We analyze, numerically, the generation, sudden death
and revival of three qubit entanglement as a function of initial entanglement
of qubits A1A2 and degree of squeezing of electromagnetic field. Global
negativity of partially transposed state operator is used to quantify the
entanglement of three atom state. It is found that the initial entanglement of
two mode field as well as that of the pair A1A2, both, contribute to three atom
entanglement. A maximally entangled single excitation Bell pair in first cavity
and two mode field with squeeze parameter s=0.64 are the initial conditions
that optimize the peak value of three qubit mixed state entanglement. A smaller
value of s=0.4 under similar conditions is found to generate a three qubit
mixed state with comparable entanglement dynamics free from entanglement sudden
death.Comment: 14 pages, 7 figures, sections III and IV merged with section II and
analytic expressions moved to Appendices A and B. Figures improved and
corrected typo
Correlation between NS5A dimerization and hepatitis C virus replication
Hepatitis C virus (HCV) is the main agent of acute and chronic liver diseases leading to cirrhosis and hepatocellular carcinoma. The current standard therapy has limited efficacy and serious side effects. Thus, the development of alternate therapies is of tremendous importance. HCV NS5A (nonstructural 5A protein) is a pleiotropic protein with key roles in HCV replication and cellular signaling pathways. Here we demonstrate that NS5A dimerization occurs through Domain I (amino acids 1-240). This interaction is not mediated by nucleic acids because benzonase, RNase, and DNase treatments do not prevent NS5A-NS5A interactions. Importantly, DTT abrogates NS5A-NS5A interactions but does not affect NS5A-cyclophilin A interactions. Other reducing agents such as tris(2-carboxyethyl) phosphine and 2-mercaptoethanol also abrogate NS5A-NS5A interactions, implying that disulfide bridges may play a role in this interaction. Cyclophilin inhibitors, cyclosporine A, and alisporivir and NS5A inhibitor BMS-790052 do not block NS5A dimerization, suggesting that their antiviral effects do not involve the disruption of NS5A-NS5A interactions. Four cysteines, Cys-39, Cys-57, Cys-59, and Cys-80, are critical for dimerization. Interestingly, the four cysteines have been proposed to form a zinc-binding motif. Supporting this notion, NS5A dimerization is greatly facilitated by Zn2+ but not by Mg2+ or Mn2+. Importantly, the four cysteines are vital not only for viral replication but also critical for NS5A binding to RNA, revealing a correlation between NS5A dimerization, RNA binding, and HCV replication. Altogether our data suggest that NS5A-NS5A dimerization and/or multimerization could represent a novel target for the development of HCV therapies
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