After more than 70 years since its discovery, CF3CHN2 was found to possess a novel reactivity mode: N-terminal electrophile. With C-nucleophiles it gives hydrazones that are easily transformed into ...valuable CF3-heterocycles.
Dynamic characteristics of strongly coupled classical one-component Coulomb and Yukawa plasmas are obtained within the nonperturbative model-free moment approach without any data input from ...simulations so that the dynamic structure factor (DSF) satisfies the first three nonvanishing sum rules automatically. The DSF, dispersion, decay, sound speed, and other characteristics of the collective modes are determined using exclusively the static structure factor calculated from various theoretical approaches including the hypernetted chain approximation. A good quantitative agreement with molecular dynamics simulation data is achieved.
The study of the effects of auxins on potato tuberization corresponds to one of the oldest experimental systems in plant biology, which has remained relevant for over 70 years. However, only ...recently, in the postgenomic era, the role of auxin in tuber formation and other vital processes in potatoes has begun to emerge. This review describes the main results obtained over the entire period of auxin-potato research, including the effects of exogenous auxin; the content and dynamics of endogenous auxins; the effects of manipulating endogenous auxin content; the molecular mechanisms of auxin signaling, transport and inactivation; the role and position of auxin among other tuberigenic factors; the effects of auxin on tuber dormancy; the prospects for auxin use in potato biotechnology. Special attention is paid to recent insights into auxin function in potato tuberization and stress resistance. Taken together, the data discussed here leave no doubt on the important role of auxin in potato tuberization, particularly in the processes of tuber initiation, growth and sprouting. A new integrative model for the stage-dependent auxin action on tuberization is presented. In addition, auxin is shown to differentially affects the potato resistance to biotrophic and necrotrophic biopathogens. Thus, the modern auxin biology opens up new perspectives for further biotechnological improvement of potato crops.
Cytokinins (CK) are one of the most important classes of phytohormones that regulate a wide range of processes in plants. A CK receptor, a sensor hybrid histidine kinase, was discovered more than 20 ...years ago, but the structural basis for its signaling is still a challenge for plant biologists. To date, only two fragments of the CK receptor structure, the sensory module and the receiver domain, were experimentally resolved. Some other regions were built up by molecular modeling based on structures of proteins homologous to CK receptors. However, in the long term, these data have proven insufficient for solving the structure of the full-sized CK receptor. The functional unit of CK receptor is the receptor dimer. In this article, a molecular structure of the dimeric form of the full-length CK receptor based on AlphaFold Multimer and ColabFold modeling is presented for the first time. Structural changes of the receptor upon interacting with phosphotransfer protein are visualized. According to mathematical simulation and available data, both types of dimeric receptor complexes with hormones, either half- or fully liganded, appear to be active in triggering signals. In addition, the prospects of using this and similar models to address remaining fundamental problems of CK signaling were outlined.
The effectiveness of inhalation therapy can be significantly reduced by a number of problems. For example, inhalation technique errors can reduce the dose delivered by 22-95% compared to the optimal ...value in patients with technical errors in the use of the inhaler. Sub-optimal inspiratory flow rates in a number of patients with chronic obstructive pulmonary disease and asthma are often the cause of technical errors during inhalation. Patient education does not produce the expected results, as the underlying cause of reduced flow is high hyperinflation and weakening of the respiratory musculature. The use of technologically outdated inhalers is another significant cause of reduced therapy effectiveness. Patient education and even conversion to a different inhaler do not always increase the effectiveness of therapy. Respimat, a brand new delivery agent introduced in 2004, allows 39% to 67% of the nominal dose to be delivered to the airways, while the degree of pulmonary deposit is independent of inspiratory flow and pulmonary drug deposit does not decrease with increasing obstruction. Compared to powder inhalers, Respimat creates less resistance to airflow on inhalation. In addition, Respimat is an active device that requires no effort on the part of the patient to move the aerosol particles. These features make Respimat the new standard for inhalation therapy. This review aims to familiarise readers with the main features of the Respimat and the latest research findings
There are three ways in which the cell efficiency of silicon solar cells may be improved by better exploitation of the solar spectrum: down-conversion (cutting one high energy photon into two low ...energy photons), photoluminescence (shifting photons into wavelength regions better accepted by the solar cell) and up-conversion (combining low energy photons to one high energy photon). In this paper, we present the state of the art of these three methods and discuss the suitability of materials available today for application to silicon solar cells.
Ultrastructural studies of the hippocampus and the prefrontal cortex of rats were performed 7, 30, and 50 days after their damage by neurotoxicant trimethyltin chloride (TMT). Significant damage to ...neurons was observed in both brain structures. In the hippocampus, a large number of autophagosomes (0.9±0.1 per μm
2
) appeared in the soma of neurons, dendrites, and axons in 7 days after intoxication. In addition, we observed the appearance of hyperchromic neurons with abnormal structure of mitochondria. In the prefrontal cortex, damaged neurons also contained autophagosomes, but their number was significantly lower (0.3±0.1 per μm
2
). The number of autophagosomes decreased with increasing the time after TMT administration: 30 days after injection, the content of autophagosomes in the hippocampus was 0.10±0.01 per μm
2
, while in the prefrontal cortex, autophagosomes were no longer found. We hypothesized that autophagy in the hippocampus was not effective enough to prevent neuronal death caused by the neurotoxicant.
Abstract
On the basis of the generalized Poisson–Boltzmann equation derived from the Bogolyubov chain of equations for the equilibrium distribution functions in the pair correlation approximation, a ...general expression is proposed for the Helmholtz free energy of a system that contains any number of components and whose particles interact via arbitrary potentials. This opens up an extraordinary opportunity to simultaneously treat a whole range of physical effects including partial ionization, quantum effects of diffraction and electron degeneracy, short- and long-range interactions of charged particles with neutrals, finite size effects, etc. It is shown that all medium constituents are tied together in a single screening matrix, whose determinant and trace determine the excess contribution to the free energy. The approach developed is then applied to the problem of the ionization potential depression (IPD) leading to quite simple analytical expressions, which turn out to be useful for various practical purposes. In particular, for a single ionization from the neutral state the IPD is shown to significantly depend on the ionization degree such that it consists of the difference of charged and neutral contributions for a fully ionized plasma and turns non-zero for an almost neutral medium. On the other hand, for a multiple ionization process finite size effects of atoms and ions are demonstrated to be of great importance and accounted for in order to achieve good agreement with experimental data on the IPD under warm dense matter conditions.
The present study aimed to understand the relationship between pharmacological activation of mGlu4 receptors and regulation of its gene in the hippocampus.
The expression level of the GRM4 gene, ...encoding mGluR4 receptors, was studied in the hippocampus and frontal cortex of rats after pharmacological activation of the receptor with positive allosteric modulator (E)-4-(2-Phenylethenyl)-2-pyrimidinamine (TCN 238). The drug was injected subcutaneously four times at a dose of 2mg/kg. The animals were previously trained with hippocampal-dependent task and after the treatment were tested for memory retrieval. The expression level of GRM4 was determined by qRT-PCR in control and experimental groups of animals one and five days post-treatment.
We found that TCN 238 did not affect the performance of the learned task. However, the expression level of GRM4 in the hippocampus was reliable down-regulated five days after treatment with TCN 238. In addition, we showed that the expression level of GABRA1, encoding GABAA α-subunit was downregulated five days after the treatment in the frontal cortex.
Subacute pharmacological intervention in mGluR activity by the selective positive modulator TCN 238 has led to adaptive rearrangements of transcription processes in the hippocampus. Moreover, this regulation affected GABA system, confirming importance of the brain excitation-inhibition balance. Since the pharmacological influence on mGluR activity can be regarded as a promising tool aimed to correct brain dysfunction, the properties of mGluR modulators should be studied in more detail, including the level of gene transcription.
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