На основе определенной математической модели рассмотрен способ измерения и контроля свойств контактов металл – полупроводник. Предложенная математическая модель не требует создания специальной тестовой структуры и может быть использована для определения концентрации и подвижности носителей заряда по результатам измерений удельного сопротивления и коэффициента Холла, а также для оценки однородности пластин и пленок по удельному сопротивлению. Расчетные формулы получены без приближений путем решения краевых задач, адекватных физическим условиям. Проанализированы условия, при которых сопротивление растекания двух контактов складывается из сопротивлений растекания каждого контакта в отдельности.

В статье при помощи показателя Перкаля рассчитана транспортная доступность в разрезе районов Республики Беларусь

In infected plant cells, closterovirus replicative polyproteins 1a and 1ab drive membrane remodeling and formation of multivesicular replication platforms. Polyprotein 1a contains a variable Central Region (CR) between the methyltransferase and helicase domains. In a previous study, we have found that transient expression of the Beet yellows virus CR-2 segment (aa 1305-1494) in Nicotiana benthamiana induces the formation of ~1 µm mobile globules originating from the ER membranes. In the present study, sequence analysis has shown that a part of the CR named the “Zemlya region” (overlapping the CR-2), is conserved in all members of the Closterovirus genus and contains a predicted amphipathic helix (aa 1368-1385). By deletion analysis, the CR-2 region responsible for the induction of 1-μm globules has been mapped to aa 1368-1432. We suggest that the conserved membrane-modifying region of the BYV 1a may be involved in the biogenesis of closterovirus replication platforms.

Human B-cell receptor-associated protein BAP31 (HsBAP31) is the endoplasmic reticulum-resident protein involved in protein sorting and transport as well as pro-apoptotic signaling. Plant orthologs of HsBAP31 termed 'plant BAP-like proteins' (PBL proteins) have thus far remained unstudied. Recently, the PBL protein from Nicotiana tabacum (NtPBL) was identified as an interactor of Nt-4/1, a plant protein known to interact with plant virus movement proteins and affect the long-distance transport of potato spindle tuber viroid (PSTVd) via the phloem. Here, we have compared the sequences of PBL proteins and studied the biochemical properties of NtPBL. Analysis of a number of fully sequenced plant genomes revealed that PBL-encoding genes represent a small multigene family with up to six members per genome. Two conserved motifs were identified in the C-terminal region of PBL proteins. The NtPBL C-terminal hydrophilic region (NtPBL-C) was expressed in bacterial cells, purified, and used for analysis of its RNA binding properties in vitro. In gel shift experiments, NtPBL-C was found to bind several tested RNAs, showing the most efficient binding to microRNA precursors (pre-miRNA) and less efficient interaction with PSTVd. Mutational analysis suggested that NtPBL-C has a composite RNA-binding site, with two conserved lysine residues in the most C-terminal protein region being involved in binding of pre-miRNA but not PSTVd RNA. Virus-mediated transient expression of NtPBL-C in plants resulted in stunting and leaf malformation, developmental abnormalities similar to those described previously for blockage of miRNA biogenesis/function. We hypothesize that the NtPBL protein represents a previously undiscovered component of the miRNA pathway.

The plant-specific 4/1 protein interacts, both in yeast two-hybrid system and in vitro, and co-localizes in plant cells with plant BAP-like protein, the orthologue of human protein BAP31. In yeast two-hybrid system, we identified a number of Nicotiana benthamiana protein interactors of Nt-4/1, the protein known to affect systemic transport of potato spindle tuber viroid. For one of these interactors, an orthologue of human B-cell receptor-associated protein 31 (BAP31) termed plant BAP-like protein (PBL), the ability to interact with Nt-4/1 was studied in greater detail. Analyses of purified proteins expressed in bacterial cells carried out in vitro with the surface plasmon resonance (SPR) spectroscopy revealed that the N. tabacum PBL (NtPBL) was able to interact with Nt-4/1 with high-affinity, and that their complex can form at physiologically relevant concentrations of both proteins. Subcellular localization studies of 4/1-GFP and NtPBL-mRFP transiently co-expressed in plant cells revealed the co-localization of the two fusion proteins in endoplasmic reticulum-associated bodies, suggesting their interaction in vivo. The N-terminal region of the Nt-4/1 protein was found to be required for the specific subcellular targeting of the protein, presumably due to a predicted amphipathic helix mediating association of the Nt-4/1 protein with cell membranes. Additionally, this region was found to contain a trans-activator domain responsible for the Nt-4/1 ability to activate transcription of a reporter gene in yeast.

Enteroviruses (EVs) belong to the family Picornaviridae and are responsible for mild to severe diseases in mammals including humans and non-human primates (NHP). Simian EVs were first discovered in the 1950s in the Old World Monkeys and recently in wild chimpanzee, gorilla and mandrill in Cameroon. In the present study, we screened by PCR EVs in 600 fecal samples of wild apes and monkeys that were collected at four sites in Gabon. A total of 32 samples were positive for EVs (25 from mandrills, 7 from chimpanzees, none from gorillas). The phylogenetic analysis of VP1 and VP2 genes showed that EVs identified in chimpanzees were members of two human EV species, EV-A and EV-B, and those identified in mandrills were members of the human species EV-B and the simian species EV-J. The identification of two novel enterovirus types, EV-B112 in a chimpanzee and EV-B113 in a mandrill, suggests these NHPs could be potential sources of new EV types. The identification of EV-B107 and EV90 that were previously found in humans indicates cross-species transfers. Also the identification of chimpanzee-derived EV110 in a mandrill demonstrated a wide host range of this EV. Further research of EVs in NHPs would help understanding emergence of new types or variants, and evaluating the real risk of cross-species transmission for humans as well for NHPs populations. Published online 2017 Jan 12. doi: 10.1371/journal.pone.0169067

Near complete rabies virus N gene sequences (1,110 nt) were determined for 82 isolates obtained from different regions of Russia between 2008 and 2016. These sequences were analyzed together with 108 representative GenBank sequences from 1977–2016 using the Bayesian coalescent approach. The timing of the major evolutionary events was estimated. Most of the isolates represented the steppe rabies virus group C, which was found over a vast geographic region from Central Russia to Mongolia and split into three groups (C0-C2) with discrete geographic prevalence. A single strain of the steppe rabies virus lineage was isolated in the far eastern part of Russia (Primorsky Krai), likely as a result of a recent anthropogenic introduction. For the first time the polar rabies virus group A2, previously reported in Alaska, was described in the northern part of European Russia and at the Franz Josef Land. Phylogenetic analysis suggested that all currently circulating rabies virus groups in the Russian Federation were introduced within the few last centuries, with most of the groups spreading in the 20th century. The dating of evolutionary events was highly concordant with the historical epidemiological data. Published: February 22, 2017https://doi.org/10.1371/journal.pone.0171855

В целях разработки чувствительной и селективной методики фотометрического определения рения в кислых нитратно-сульфатных растворах, образуемых при разложении молибденитовых концентратов азотной кислотой, и выявления закономерностей протекающих при этом реакций комплексообразования рения переменной валентности с сероорганическими лигандами спектрофотометрическим методом изучена система Re(VII)-HNO3-HCl-меркаптоуксусная кислота - Sn(II). Установлены оптимальные условия образования окрашенного комплексного соединения с меркаптоуксусной кислотой в смешанном соляно-азотнокислом растворе, определены состав и устойчивость образующегося комплекса. Предложен механизм окислительно-восстановительных реакций, протекающих в процессе комплексообразования. Разработана методика контроля содержания рения в продуктах гидрометаллургической переработки молибденитовых концентратов, позволяющая определять рений в присутствии сопутствующих элементов (Mo, Cu, Fe, Ni и др.) и окислителей (>120 г/л NOg), включающая в себя предварительное отделение молибдена и других мешающих примесей путем селективной сорбции ионов ReO 4 на сильноосновном анионите марки ЧФО с последующей десорбцией их 5 М HNO3 и фотометрическое определение рения в элюате в виде окрашенного в оранжево-желтый цвет (Amax = 460 нм) смешанно-ли- гандного комплекса Re (III) предполагаемого состава [Re(L)3NOCl]-, где L — анион меркаптоуксусной кислоты. Разработанная методика определения рения применена к анализу сливов промывной серной кислоты сернокислотного цеха медеплавильного завода АО «Алмалыкский ГМК».