4,254 research outputs found
High resolution Fourier transform far infrared spectroscopy of CH3OD
No full textThe high resolution Fourier transform far infrared spectrum of the torsion rotation band of CH3OD has been recorded in the range 20-350 cm(-1) at a resolution of 0.002 cm(-1). The spectrum shows splitting of the lines due to strong torsional, rotational, and vibrational interactions in the molecule. Assignments were possible for rotational subbands in the ground torsional state (n = 0) for K values up to 15 and J values of up to 30, for all the symmetry species. In addition, some subbands were also identified which involve torsionally excited states. A total of 63 b-type subband origins, including 6 Q-branch origins obtained from microwave (MW) and millimeter-wave (MMW) studies, were fitted to a semiempirical model. The molecular parameters so determined were able to reproduce the subband origins almost to within experimental uncertainty. The torsional-rotational state-dependent effective molecular parameters and the asymmetry splitting parameters have also been determined. These should prove valuable in the assignment of transitions involving torsionally excited states in the ground vibrational state. (C) 1997 Academic Press
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Early Buddhist architecture of Bengal: morphological study on the vihāra of c. 3rd to 8th centuries
No full textThis dissertation examines the evolution of early Buddhist architectural forms of Bengal, specifically its vihāra and shrine structures. In general, this research explores Gupta and post-Gupta (c. third to eighth centuries AD) vihāra architecture of Bengal, where the primary focus is on the Buddhist shrine architecture constructed during this period. There is a preconception amongst historians that the period between the Gupta and the Pāla periods was characterized by disorder and chaos, commonly known as the period of Matsyanyayam. This is the reason why discussions on the architectural history of Bengal have generally commenced from the Pāla period (c. 750 AD onwards). Analyzing extant and new evidences this study argues that the Buddhist architecture of Bengal thrived during the intervening period, albeit under the patronage of local kings and rulers. In the field of art and sculpture it is accepted that Buddhist Pāla art was a continuation of previous Gupta art forms, where post-Gupta period acted as the transition or a bridge. Following this general pattern, as this thesis argues, the rectangular Gupta shrine plan takes a mature cruciform shape during the Pāla period through a complex morphological development. The nature of Buddhist shrine architecture in Bengal during the early Gupta, later Gupta, and post-Gupta periods is described in the light of analyzed archaeological findings and architectural trends
Photodynamic effects of toluidine blue on staphylococcal biofilms
No full textStaphylococci are important causes of nosocomial and medical-device-related infections. Their virulence is attributed to the elaboration of biofilms that protect the organisms from immune system clearance and to increased resistance to phagocytosis and antibiotics. Photodynamic treatment (PDT) has been proposed as an alternative approach for the inactivation of bacteria in biofilms. In this study, we have investigated the effect of the photodynamic action of toluidine blue O (TBO) on the viability and structure of biofilms of Staphylococcus epidermidis and of a methicillin-resistant Staphylococcus aureus strain. Significant inactivation of cells was observed when staphylococcal biofilms were exposed to TBO and laser simultaneously. The effect was found to be light dose dependent. Confocal laser scanning microscopic study suggested damage to bacterial cell membranes in photodynamically treated biofilms. In addition, scanning electron microscopy provided direct evidence for the disruption of biofilm structure and a decrease in cell numbers in photodynamically treated biofilms. Furthermore, the treatment of biofilms with tetrasodium EDTA followed by PDT enhanced the photodynamic efficacy of TBO in Staphylococcus epidermidis, but not in Staphylococcus aureus, biofilms. The results suggest that photodynamic treatment may be a useful approach for the inactivation of staphylococcal biofilms adhering to solid surfaces of medical implants. The results are quite interesting for future applications
Computing many faces in arrangements of lines and segments
No full textWe present randomized algorithms for computing many faces in an arrangement of lines or of segments in the plane, which are considerably simpler and slightly faster than the previously known ones. pn The main new idea is a simple randomized O(n log n) expected time algorithm for computing root n cells in an arrangement of n lines.A part of this work was done while the first and third authors were visiting Charles University and while the first author was visiting Utrecht University. The first author has been supported by National Science Foundation Grant CCR-93-01259 and an NYI aword. The second author has been supported by Charles University grant No. 351 and Czech Republic Grant GACR 201/93/2167. The third author has been supported by the Netherlands' Organization for Scientific Research (NWO) and partially supported by ESPRIT Basic Research Action No. 7141 (project ALCOM 2:Algorithms and Complexity)
Fluctuations of entropy production of a run-and-tumble particle
No full textOut-of-equilibrium systems continuously generate entropy, with its rate of production being a fingerprint of nonequilibrium conditions. In small-scale dissipative systems subject to thermal noise, fluctuations of entropy production are significant. Hitherto, mean and variance have been abundantly studied, even if higher moments might be important to fully characterize the system of interest. Here, we introduce a graphical method to compute any moment of entropy production for a generic discrete-state system. Then, we focus on a paradigmatic model of active particles, i.e., run-and-tumble dynamics, which resembles the motion observed in several micro-organisms. Employing our framework, we compute the first three cumulants of the entropy production for a discrete version of this model. We also compare our analytical results with numerical simulations. We find that as the number of states increases, the distribution of entropy production deviates from a Gaussian. Finally, we extend our framework to a continuous state-space run-and-tumble model, using an appropriate scaling of the transition rates. The approach presented here might help uncover the features of nonequilibrium fluctuations of any current in biological systems operating out-of-equilibrium.LB
Search for CP violation using triple product asymmetries in Λ b 0 → pK−π+π−, Λ b 0 → pK−K+K− and Ξ b 0 → pK−K−π+ decays
No full text© 2018, The Author(s). A search for CP and P violation using triple-product asymmetries is performed with Λb0 → pK−π+π−, Λb0 → pK−K+K− and Ξb0 → pK−K−π+ decays. The data sample corresponds to integrated luminosities of 1.0 fb−1 and 2.0 fb−1, recorded with the LHCb detector at centre-of-mass energies of 7 TeV and 8 TeV, respectively. The CP - and P - violating asymmetries are measured both integrating over all phase space and in specific phase-space regions. No significant deviation from CP or P symmetry is found. The first observation of Λb0 → pK−χc0(1P)(→π+π−, K+K−) decay is also reported
Test of lepton universality with Λb0→ pK-ℓ+ℓ- decays
No full text© 2020, The Author(s). The ratio of branching fractions of the decays Λb0 → pK−e+e− and Λb0 → pK−μ+μ−,RpK−1, is measured for the first time using proton-proton collision data corresponding to an integrated luminosity of 4.7 fb−1 recorded with the LHCb experiment at center-of-mass energies of 7, 8 and 13 TeV. In the dilepton mass-squared range 0.1 < q2< 6.0 GeV2/c4 and the pK− mass range m(pK−) < 2600 MeV/c2, the ratio of branching fractions is measured to be RpK−1=1.17−0.16+0.18±0.07, where the first uncertainty is statistical and the second systematic. This is the first test of lepton universality with b baryons and the first observation of the decay Λb0 → pK−e+e−. [Figure not available: see fulltext.]
Test of lepton universality with Λb0→ pK-ℓ+ℓ- decays
No full text© 2020, The Author(s). The ratio of branching fractions of the decays Λb0 → pK−e+e− and Λb0 → pK−μ+μ−,RpK−1, is measured for the first time using proton-proton collision data corresponding to an integrated luminosity of 4.7 fb−1 recorded with the LHCb experiment at center-of-mass energies of 7, 8 and 13 TeV. In the dilepton mass-squared range 0.1 < q2< 6.0 GeV2/c4 and the pK− mass range m(pK−) < 2600 MeV/c2, the ratio of branching fractions is measured to be RpK−1=1.17−0.16+0.18±0.07, where the first uncertainty is statistical and the second systematic. This is the first test of lepton universality with b baryons and the first observation of the decay Λb0 → pK−e+e−. [Figure not available: see fulltext.]
A prospective study of incidence and risk factors for secondary glaucoma after penetrating keratoplasty
No full textAim: To carry out a prospective study to analyze the incidence and risk factors for secondary glaucoma after penetrating keratoplasty (PK). Materials and Methods: Three hundred and eleven consecutive penetrating keratoplasties that were performed between January 1, 2006, and December 31, 2008, with a follow-up of 12 months were prospectively analyzed to determine the factors associated with postoperative glaucoma. Results: Of 311 eyes, secondary glaucoma developed in 57 cases. This yields an incidence of 18.3%. In conditions, such as aphakic bullous keratopathy, the incidence of post-PK glaucoma was 3.0%; in pseudophakic bullous keratopathy 14.0%, and in cases of failed graft 16.0%, while in cases of corneal ulcer and corneal opacity it was 49.0% and 18.0%, respectively. Conclusion: We conclude in our study that the incidence of glaucoma developing post-PK was highest in phakic eyes, which may be due to the formation of posterior synechiae and development of intumescent cataract. Higher incidence of glaucoma developing in infective cases could be due to recipient hot eye and the high incidence in cases of large graft could be attributed to the formation of peripheral anterior synechiae
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