Perturbation of Short Hydrogen Bonds in Photoactive Yellow Protein via Noncanonical Amino Acid Incorporation.

Photoactive yellow protein (PYP) is a small photoreceptor protein that has two unusually short hydrogen bonds between the deprotonated p-coumaric acid chromophore and two amino acids, a tyrosine and a glutamic acid. This has led to considerable debate as to whether the glutamic acid-chromophore hydrogen bond is a low barrier hydrogen bond, with conflicting results in the literature. We have modified the p K of the tyrosine by amber suppression and of the chromophore by chemical substitution.

New association between Amblyomma parvitarsum (Acari: Ixodidae) and the endemic lizard Liolaemus eleodori (Iguania: Liolaemidae) in Argentina.

Records of lizard parasitizing ticks in Argentina are scarce and incomplete. We recorded a new population of Liolaemus eleodori, a lizard endemic to Argentina, parasitized by the hard tick Amblyomma parvitarsum. Hence, the objective of this study is to report this new association and enhance knowledge about its parasitism on reptiles of Argentina.

Nonadiabatic Photodynamics of Retinal Protonated Schiff Base in Channelrhodopsin 2.

Channelrhodopsin 2 (ChR2) is a light-gated ion channel and an important tool in optogenetics. Photoisomerization of retinal protonated Schiff base (RPSB) in ChR2 triggers channel activation. Despite the importance of ChR2 in optogenetics, the detailed mechanism for photoisomerization and channel activation is still not fully understood.

On combining the conductor-like screening model and optimally tuned range-separated hybrid density functionals.

Range-separated hybrid functionals whose range-separation parameter γ has been nonempirically tuned to a particular molecule have been shown to yield frontier orbital energies and other properties in very good agreement with experiments. However, many cases, such as organic optoelectronic devices, require the description of molecules embedded in an environment. This can be done by combining the γ-tuning procedure with polarizable continuum models in general and the very versatile conductor-like screening model in particular.

Geodesic interpolation for reaction pathways.

The development of high throughput reaction discovery methods such as the ab initio nanoreactor demands massive numbers of reaction rate calculations through the optimization of minimum energy reaction paths. These are often generated from interpolations between the reactant and product endpoint geometries. Unfortunately, straightforward interpolation in Cartesian coordinates often leads to poor approximations that lead to slow convergence.

Rank reduced coupled cluster theory. I. Ground state energies and wavefunctions.

We propose a compression of the opposite-spin coupled cluster doubles amplitudes of the form τ ≡U TU , where U are the n-highest magnitude eigenvectors of the MP2 or MP3 doubles amplitudes. Together with a corresponding parameterization of the opposite-spin coupled cluster Lagrange multipliers of the form λ ≡U LU , this yields a fully self-consistent parameterization of reduced-rank coupled cluster equations in terms of the Lagrangian LT,L. Making this Lagrangian stationary with respect to the L parameters yields a perfectly determined set of equations for the T equations and coupled cluster energy.

The photochemical ring-opening of 1,3-cyclohexadiene imaged by ultrafast electron diffraction.

The ultrafast photoinduced ring-opening of 1,3-cyclohexadiene constitutes a textbook example of electrocyclic reactions in organic chemistry and a model for photobiological reactions in vitamin D synthesis. Although the relaxation from the photoexcited electronic state during the ring-opening has been investigated in numerous studies, the accompanying changes in atomic distance have not been resolved. Here we present a direct and unambiguous observation of the ring-opening reaction path on the femtosecond timescale and subångström length scale using megaelectronvolt ultrafast electron diffraction.

What do the US advanced kidney disease patients want? Comprehensive pre-ESRD Patient Education (CPE) and choice of dialysis modality.

Improvement in Home Dialysis (HoD) utilizations as a mean to improve the patient reported and health services outcomes, has been a long-held goal of the providers and healthcare system in United States. However, measures to improve HoD rates have yielded limited success so far. Lack of patient awareness of chronic kidney disease (CKD) and its management options, is one of the important barriers against patient adoption of HoD.

CDK12 phosphorylates 4E-BP1 to enable mTORC1-dependent translation and mitotic genome stability.

The RNA polymerase II (RNAPII) C-terminal domain kinase, CDK12, regulates genome stability, expression of DNA repair genes, and cancer cell resistance to chemotherapy and immunotherapy. In addition to its role in mRNA biosynthesis of DNA repair genes, we show here that CDK12 phosphorylates the mRNA 5' cap-binding repressor, 4E-BP1, to promote translation of mTORC1-dependent mRNAs. In particular, we found that phosphorylation of 4E-BP1 by mTORC1 (T37 and T46) facilitates subsequent CDK12 phosphorylation at two Ser-Pro sites (S65 and T70) that control the exchange of 4E-BP1 with eIF4G at the 5' cap of and other target mRNAs.

Evolutionary effects of the AID/APOBEC family of mutagenic enzymes on human gamma-herpesviruses.

The human gamma-herpesviruses, Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus, establish lifelong latency in B cells and are associated with multiple malignancies. Virus-host coevolution often drive changes in both host immunity and in the viral genome. We consider one host immune mechanism, the activation-induced deaminase (AID)/APOBEC family of cytidine deaminases, that induces mutations in viral DNA.

Concurrent Criterion-related Validity, Reliability, and Responsiveness to Treatment of the Figure-of-Four Position for Measurement of Anterior Hip Joint Structures Tightness.

Objective: The objective of this study was to examine the intra- and intertester reliability, concurrent criterion-related validity, and responsiveness to treatment of the "figure-of-four" position.

Methods: A total of 52 asymptomatic male soccer players participated in this study. The intraclass correlation coefficient (2, 1) was used to determine intra- and intertester reliability of the figure-of-four position.

Large Impact of the Decay of Niobium Isomers on the Reactor ν[over ¯]_{e} Summation Calculations.

Even mass neutron-rich niobium isotopes are among the principal contributors to the reactor antineutrino energy spectrum. They are also among the most challenging to measure due to the refractory nature of niobium, and because they exhibit isomeric states lying very close in energy. The β-intensity distributions of ^{100gs,100m}Nb and ^{102gs,102m}Nb β decays have been determined using the total absorption γ-ray spectroscopy technique.

Ab Initio Computation of Rotationally-Averaged Pump-Probe X-ray and Electron Diffraction Signals.

We develop a new algorithm for the computation of the rotationally averaged elastic molecular diffraction signal for the cases of perpendicular or parallel pump-probe geometries. The algorithm first collocates the charge density from an arbitrary ab initio wave function onto a Becke quadrature grid [A. Becke, J.

Sub-Femtosecond Stark Control of Molecular Photoexcitation with Near Single-Cycle Pulses.

Electric fields can tailor molecular potential energy surfaces by interaction with the electronic state-dependent molecular dipole moment. Recent developments in optics have enabled the creation of ultrashort few-cycle optical pulses with precise control of the carrier envelope phase (CEP) that determines the offset of the maxima in the field and the pulse envelope. This opens news ways of controlling ultrafast molecular dynamics by exploiting the CEP.

Multicolor Mechanochromism of a Polymer/Silica Composite with Dual Distinct Mechanophores.

The development of a multicolor mechanochromic polymer/silica composite is achieved by using two distinct types of mechanochromophores. The multicolor mechanochromism of the composite containing diarylbibenzofuranone in silica-rich domains and naphthopyran in the polymer-rich domain is observed. The obtained composite shows blue, green, and orange colors according to the intensity of applied mechanical stimuli, solvent addition, and lapse of time.

Rab29 activation of the Parkinson's disease-associated LRRK2 kinase.

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Mechanisms of action and historical facts on the use of intravenous immunoglobulins in systemic lupus erythematosus.

The current existing therapies for severe cases of systemic lupus erythematosus (SLE) patients are still limited. Intravenous immunoglobulin (IVIGs), which are purified from the plasma of thousands of healthy human donors, have been profiled as efficacious and life-saving options for SLE patients refractory to conventional therapy. The specific mechanism of action by which IVIGs generate immunomodulation in SLE is not currently understood.

Indomethacin blocks the increased conditioned rewarding effects of cocaine induced by repeated social defeat.

It is well established that repeated social defeat stress can induce negative long-term consequences such as increased anxiety-like behavior and enhances the reinforcing effect of psychostimulants in rodents. In the current study, we evaluated how the immune system may play a role in these long-term effects of stress. A total of 148 OF1 mice were divided into different experimental groups according to stress condition (exploration or social defeat) and pre-treatment (saline, 5 or 10 mg/kg of the anti-inflammatory indomethacin) before each social defeat or exploration episode.

Ab Initio Prediction of Fluorescence Lifetimes Involving Solvent Environments by Means of COSMO and Vibrational Broadening.

The fluorescence lifetime is a key property of fluorophores that can be utilized for microenvironment probing, analyte sensing, and multiplexing as well as barcoding applications. For the rational design of lifetime probes and barcodes, theoretical methods have been developed to enable the ab initio prediction of this parameter, which depends strongly on interactions with solvent molecules and other chemical species in the emitteŕs immediate environment. In this work, we investigate how a conductor-like screening model (COSMO) can account for variations in fluorescence lifetimes that are caused by such fluorophore-solvent interactions.

Photoannealing of Merocyanine Aggregates.

In this work we elucidate the fundamental difference between aggregate formation of donor-π-acceptor merocyanines in their electronic ground and excited states. While increasing the π-bridge size favors formation of π-stacked aggregates in the dark, irradiation with visible light causes reorientation of the dyes to form prototype H-aggregates with compensating dipole moments. This photoannealing changes the supramolecular structure and its UV-vis spectroscopic properties dramatically, thus being of importance for the function of active layers composed of these dyes.

Tourniquet Training Program Assessed by a New Performance Score.

Unlabelled: IntroductionApplication of a tourniquet is the cornerstone in management of combat-related extremity hemorrhages. Continuous and appropriate training is required to use tourniquets correctly.HypothesisThe aim of this study was to analyze the impact of a refresher training session, conducted directly in the theater of military operations, on the performance of tourniquet use.