Thin active region HgCdTe-based quantum cascade laser with quasi-relativistic dispersion law.

HgCdTe is promising as a material to solve a problem of the development of semiconductor sources with an operational frequency range of 6-10 THz due to the small optical phonon energies and electron effective mass. In this study, we calculate the dependence of the metal-metal waveguide characteristics on the number of cascades for the 3-well design HgCdTe-based quantum cascade laser at 8.3 THz. It is shown that four cascades are sufficient for lasing at a lattice temperature of 80 K due to the large gain in the active medium. The results of this study provide a way to simplify the fabrication of thin active region HgCdTe-based quantum cascade lasers for operation in the range of the GaAs phonon Reststrahlen band inaccessible to existing quantum cascade lasers.

Contributi scientifici in memoria di Antonio Fusco.

Come si leggerà nell'Introduzione della sezione propriamente scientifica del Volume, il presente testo nasce dalla volontà e, soprattutto, dall'esigenza culturale di omaggiare il fu Prof. Antonio Fusco. Un debito scientifico ed umano che trova il suo locus naturale in questa prima parte del testo stesso, cui farà poi seguito la parte propriamente scientifica. In siffatta parentesi dovuta per le ragioni appena menzionate, il lettore, l'amico o l'allievo dell'opera del Prof. Fusco potranno trovare un suo sintetico Curriculum Vitae, correlato da una specifica ed accurata prosa, svolta dal già Magnifico Rettore Carlo Cipolli; il quale, oltre che evidenziare, ricordando, i meriti del collega oramai scomparso, aggiunge alsuo scritto un elemento che sarebbe imprescindibile a non trasformare lo stesso in una mera sequenza di parole: l'amicizia e l'affetto per un amico che, oramai, non c'è più. A fine lettura, evidente risuonerà il fatto che la vita di ognuno, se mossa dalla passione per ciò per cui si è predisposti cognitivamente e psicologicamente, può essere ricca di riconoscimenti, riconoscenze e soddisfazioni che, lungi dal divenire un cuscino di allori su cui adagiarsi, per una mente creativa come quella del Prof. Fusco hanno funto solo da motivazioni ad agire instancabilmente guardando sempre al futuro. Il lavoro di una vita che, materialmente, è sancito da un supporto poco più di cm 25x15: una targa. Una materialità evidente che, con grande commozione e riconoscenza, è stata affissa il 25 ottobre 2019 sull'aula fronte l'Aula Magna del Campus "La Folcara", a testimonianza che quello spirito creativo in continua evoluzione non si ferma; non si arresta neppure con la fine biologica di chi lo ha "posseduto". Rimangono le opere ed il pensiero del Prof. Fusco e restano gli affetti. A tal proposito, il lettore troverà una breve e sentita sezione su Testimonianze; coloro i quali hanno avuto modo, nell'arco della vita accademica ed umana, personale, di Fusco di conoscerlo. Ecco, allora, che i ricordi saranno i veri protagonisti di questa parentesi. Dopo di ciò, prima dei contributi prettamente scientifici dei lavori, tenutisi in occasione del Convegno Internazionale Psicologia, Arte, Letteratura. Antiche e Nuove Tendenze, seguiranno i saluti delle autorità che in quei due giorni si sono succedute a rappresentare non solo l'istituzione affiliata, ma anche la relazione di stima e di affetto che le legava al compianto Professore. Si passerà, infine, al volume tradizionalmente inteso.

γδ T cells compose a developmentally regulated intrauterine population and protect against vaginal candidiasis.

This most comprehensive analysis to date of γδ T cells in the murine uterus reveals them to compose a unique local T-cell compartment. Consistent with earlier reports, most cells expressed a canonical Vγ6Vδ1 TCR, and produced interleukin (IL)-17A upon stimulation. Nonetheless, contrasting with earlier reports, uterine γδ T cells were not obviously intraepithelial, being more akin to sub-epithelial Vγ6Vδ1+ T cells at several other anatomical sites. By contrast to other tissues however, the uterine compartment also included non-Vγ6+, IFN-γ-producing cells; was strikingly enriched in young mice; expressed genes hitherto associated with the uterus, including the progesterone receptor; and did not require microbes for development and/or maintenance. This notwithstanding, γδ T-cell deficiency severely impaired resistance to reproductive tract infection by Candida albicans, associated with decreased responses of IL-17-dependent neutrophils. These findings emphasise tissue-specific complexities of different mucosal γδ cell compartments, and their evident importance in lymphoid stress-surveillance against barrier infection.

Expression of microRNA Potentially Regulated by AhR and CAR in Malignant Tumors of the Endometrium.

We studied microRNA whose expression can be regulated by carcinogenic compounds. Bioinformatic analysis has detected microRNA potentially regulated by xenosensor receptors AhR (miR-28, miR-30c, miR-30e, miR-139, and miR-153) and CAR (miR-29c, miR-31, miR-185, miR-625, and miR-652). Published data indicate that these microRNAs are oncosuppressors, except miR-31 that can act as an oncogene. The expression of these microRNAs in malignant tumors of the endometrium was studied. The expression of the majority of the studied microRNAs, except miR-652, was 2-3-fold below the normal, which confirms their oncosuppressor function and indicates their involvement in the endometrial carcinogenesis and hence, allows considering them as potential markers of the disease.

[Expression of miR-21 and Its Acat1, Armcx1, and Pten Target Genes in Liver of Female Rats Treated with DDT and Benzo[a]pyrene].

MiR-21 is the most studied cancer-promoting oncomiR, which target numerous tumor suppressor genes associated with proliferation, apoptosis, and invasion. Here we have studied the synthesis of miR-21 and quantified the mRNA and protein levels for miR-21 potential target genes, i.e., Acat1, Armcx1, and Pten, in the livers of female Wistar rats after their treatment with either 1,1-trichloro-2,2-di(4-chlorophenyl)ethane (DDT) or benzo[a]pyrene (BP). The most important finding appears to be the significant decrease in the miR-21 level the day after treatment with DDT with subsequent rebound. These changes are accompanied by an increase and subsequent drop in the levels of mRNAs and proteins of the Acat1, Armcx1, and Pten genes. These observations indicate the involvement of miR-21 in the posttranscriptional regulation of the Acat1, Armcx1, and Pten genes in response to xenobiotics. We hypothesize that the toxic effects of xenobiotics may be indirect and may manifest by inducing epigenetic changes, particularly through the regulation of miRNAs and their target genes.

[Effect of xenobiotics on microRNA expression in rat liver].

Using bioinformatics analysis we selected microRNAs which could bind 3'-UTR-region of cytochrome P450 (CYP) genes. Three microRNA miR-21, -221, -222, their potential targets might be mRNA for CYP1A1, and two microRNA miR-143, miR-152 for CYP2B1 accordingly were selected for experimental verification. Expression level of these microRNAs in rat liver upon benzo(a)pyrene (BP), phenobarbital (PB), and DDT induction was determined using RT-qPCR method. In rats treated by both BP, and DDT the hepatic content of miR-21, -221, -222 significantly demonstrated a 2-3-fold decrease. The decrease in miR expression was accompanied by a considerable (5.5-8.7-fold) increase in the CYP1A1-mediated EROD activity. The expression of miR-143 remained unchanged after the PB treatment, while the expression of miR-152 increased by 2 times, however, the (10.5-fold) increase in PROD activity of CYP2B was much higher. In the DDT-treated liver PROD activity increased by 20 times, the expression of miR-152 didn't change, and the expression of miR-143 increased by 2 times. The bioinformatics analysis of interactions between microRNAs and targets showed that the studied miRs can potentially bind 3'-end of AhR, ESR1, GR, CCND1, PTEN mRNA. Thus, the expression profile of miR-21, -221, -222, -143, -152 might change under the xenobiotics exposure. In silico analysis confirmed, that microRNAs target not only cytochrome P450 mRNA but also other genes, including those involved in hormonal carcinogenesis, they also can be regulated with studied miRs.

[Methodological aspects of the assessment of phytotoxicic properties of ice-melter reagents].

One of the main criteria which determine the possibility of the use of a particular type of ice-melter reagents (IMR) is the degree of their safety for the environment and human health, which is reflected in the establishment of safe doses and concentrations. In this regard, the current area of research is to improve the ecological and epidemiological principles of risk assessment of modern types of anti-icing agents. Currently available data concerning monitoring soil studies and the snow held in various cities of Russia, show that there is a process of accumulation of the main components of IMR - sodium and chlorine ions in the areas related to the roadway. The article is designated a problem of existing methodological approaches to the assessment of the phytotoxic impact in the investigation of anti-icing agents in the laboratory. There was executed the comparative characteristics of the results of the preliminary pilot studies on the phytotoxic properties of IMR under using different substrates for germination of seeds - soil and filter paper. The data obtained are characterized by differences in the degree of phytotoxic action of the same species depending upon ice-melter reagents methodical setting circuit laboratory experiment. As a result, there was shown the imperfection of the existing method of rapid analysis in relation to ice-melter materials (IMM).

[Ecological hygienic assessment of soils quality in urban areas].

Assessment of the soil quality is ofprime importance essential for the characterization of the ecological and hygienic condition of the territory, as the soil is the first link of the food chain, the source of secondary air and water pollution, as well as an integral index of ecological well-being of the environment. Herewith the qualitative analysis of soil complicated by the specifics of the soil genesis in the urban environment, in which an important role is played by manmade land bulk and alluvial soils; the inclusion of construction of material debris and household garbage in upper horizons; the growing up of the profile due to the perpetual introduction of different materials and intensive aeolian deposition. It is advisable to consider the currently neglected question of the study of soil vapor containing volatile chemicals. These pollutants penetrate into the building through cracks in the foundation and openings for utilities. Soil evaporation may accumulate in residential areas or in the soil under the building. Because of this, it is necessary to pay attention to the remediation of areas allocated for the built-up area, possessing a large-scale underground parking. Soil contamination is the result of significant anthropogenic impacts on the environment components. In general, about 89.1 million people (62.6% of the population of the country) live in terms of complex chemical load, determined by contamination offood, drinking water, air and soil. The list of microbiological and sanitary-chemical indices of the assessment of soils of urban areas may vary in dependence on the data obtained in pilot studies due to changes and additions to the assigned tasks. Timely forecast for the possibility of the usage of released lands of urban territories for the construction and the creation of new objects for different purposes should become the prevention of chronic non-infectious diseases in the population residing in urban areas.

[SCIENTIFIC EVIDENCE FOR HYGIENIC STANDARDS HARMONIZED WITH INTERNATIONAL RECOMMENDATIONS FOR PRIORITY POLLUITIONS OF SOILS].

In accordance with international approaches the ranking of permissible levels of chemicals in the soil for the Russian Federation was performed with the use of actual maximum permissible concentration (MPC), there were scientifically substantiated 33 standardsfor 26 substances and their combinations in the soil, differentiatedfor 6 groups offunctional areas for soil use. There is presented the algorithm determining the procedure for the establishment of MPC for unstudied chemicals for various functional areas of soil of populated areas, as well as draft of amendments to existing sanitary-hygienic regulations prior to processing the latter in accordance with modern requirements.

[Methodical approaches to the substantiation of hygienic requirements for the application of deicing materials].

In the paper there is presented a review of existing guidelines and rules of operation of deicing materials (DIM), as well as opportunities for their processing with the aim to ensure the security for the environment and public health. There are described the ecological- hygienic and toxicological properties of chemicals. There are reported results of a pot experiment for the assessment of the impact of DIM on the lawn.

[Regulation of safe levels of polychlorinated biphenyls in soil: Russian and international experience].

The article presents data on the levels of soil pollution by polychlorinated biphenyls (PCBs) in different regions of Russia and foreign countries. For the time present proposed regulatory value for the regulation of PCBs in soils of different land uses have been established to be set mainly on the results of the calculations of risk. However used initial values and features of the methodology for calculating determine significant variability of proposed levels of PCBs in soils. Analysis of the discussed problem of regulation of PCBs in soils in different countries permitted to make the conclusion that for the sound management of PCBs in the environment, it is necessary, first of all, the solution of questions of selection of a single standardized PCBs sample and the most appropriate method for risk assessment for the characterization of the state of contaminated soils.

[Chemoanalytical studies in the hygienic safety assessment of the influence of biological factors on the population's health].

Chromatography-mass spectrometric identification of chemical pollutants released into the ambient air and water prior to and after microbiotic purification facilities, as well as those contained in the sludge has indicated a risk from underestimation of transformation and biotransformation products resulting from the influence of biological factors. Methods for physicochemical analysis have demonstrated to be of importance for adequate hygienic evaluation of the safety and efficiency of novel technologies for biological purification of atmospheric emissions and industrial and household sewage.

[Structure and function of the essential light chain of myosin].

The review summarizes recent data on the structure and functions of the essential light chain of myosin. The essential light chain of myosin is known to stabilize the arm. Consistent with the model of the shift of the dynamic population of conformations, the conformational flexibility of the essential light chain of myosin is emphasized, which opens the way to the determination of its novel functions. The assumption is substantiated that the interaction between the C-terminal domain of the essential light chain and the N-terminal subdomain of the heavy chain of myosin is involved in the coupling of ATP hydrolysis and rotation of the arm. The recent data indicate that the isoforms of the essential light chain with the additional N-terminal peptide are capable of interacting with actin and the src-homologous domain 3 of myosin. The structural aspects of these interactions and the modulatory role of the isoforms of the essential light chain of myosin are discussed.

The power stroke causes changes in the orientation and mobility of the termini of essential light chain 1 of myosin.

Binding of ATP to the catalytic domain of myosin induces a local conformational change which is believed to cause a major rotation of an 8.5 nm alpha-helix that is stabilized by the regulatory and essential light chains. Here we attempt to follow this rotation by measuring the mobility and orientation of a fluorescent probe attached near the C- or N-terminus of essential light chain 1 (LC1). Cysteine 178 of wild-type LC1, or Cys engineered near the N-terminus of mutant LC1, was labeled with tetramethylrhodamine and exchanged into skeletal subfragment-1 (S1) or into striated muscle fibers. In the absence of ATP, the fluorescence anisotropy (r) and the rotational correlation time (rho) of S1 reconstituted with LC1 labeled near the C-terminus were 0.195 and 66.6 ns, respectively. In the presence of ATP, r and rho increased to 0.233 and 233 ns, indicating considerable immobilization of the probe. A related parameter indicating the degree of order of cross-bridges in muscle fibers, Deltar, was small in rigor fibers (-0.009) and increased in relaxed fibers (0.030). For S1 reconstituted with LC1 labeled near the N-terminus, the steady-state anisotropy was 0.168 in rigor, and increased to 0.223 in relaxed state. In fibers, the difference in rigor was large (Deltar = 0.080), because of binding to the thin filaments, and decreased to 0.037 in relaxed fibers. These results suggest that before the power stroke, in the presence of ATP or its products of hydrolysis, the termini of LC1 are immobilized and ordered, and after the stroke, they become more mobile and partially disordered. The results are consistent with crystallographic structures that show that the level of putative stabilizing interactions of LC1 with the heavy chain of S1 in the transition state is reduced as the regulatory domain rotates to its post-power stroke position.

Effect of ADP on binding of skeletal S1 to F-actin.

The proximity of skeletal myosin subfragment-1 (S1) to actin, and its orientation with respect to thin filaments of single muscle fibers, were compared in the presence and in the absence of ADP. The proximity was assessed by the efficiency of carbodiimide-induced cross-linking and the orientation by polarization of fluorescence of probes attached to the essential light chains. ADP made no difference in proximity or orientation when the molar ratio of S1 to actin was low or high. However, at the intermediate ratios, ADP made a significant difference. Strong dissociating agents, AMP-PNP and PPi, made significant differences at all ratios. To explain this behavior, it is unnecessary to invoke the ADP-induced "swinging" of the tail of S1. Rather, it is simply explained by the "two-state" model which we proposed earlier, in which S1 binds to one or to two actin protomers, depending on the saturation of the filaments with S1s. The dissociation induced by the ADP shifts the equilibrium between the two bound states. At high and low degrees of saturation, ADP is unable to significantly decrease the amount of S1 bound to F-actin. However, at intermediate saturation levels, ADP causes significantly more S1s to bind to two actins. These results suggest that the ADP-induced changes seen at the intermediate molar ratios are due to the dissociation-induced reorientation of S1.