Two-photon absorption in silicon using the real density matrix approach.

Two-photon absorption in indirect gap semiconductors is a frequently encountered, but not well-understood phenomenon. To address this, the real-density matrix approach is applied to describe two-photon absorption in silicon through the excitonic response to the interacting fields. This approach produces an analytical expression for the dispersion of the two-photon absorption coefficient for indirect-gap materials and can be used to explain trends in reported experimental data for bulk silicon both old and new with minimal fitting.

Photon Momentum Enabled Light Absorption in Silicon.

Photons do not carry sufficient momentum to induce indirect optical transitions in semiconducting materials, such as silicon, necessitating the assistance of lattice phonons to conserve momentum. Compared to direct bandgap semiconductors, this renders silicon a less attractive material for a wide variety of optoelectronic applications. In this work, we introduce an alternative strategy to fulfill the momentum-matching requirement in indirect optical transitions.

Biodegradable biopolymers: Real impact to environment pollution.

Biobased biodegradable polymers (BBP) derived from different renewable resources are commonly considered as attractive alternative to petroleum-based polymers, such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), etc. It is because they can address the issues of serious environmental problems resulted from accumulation of plastic wastes. In the review current methods of obtaining of most abundant BBP, polylactic acid (PLA) and polyhydroxybutyrate (PHB), have been studied with an emphasis on the toxicity of compounds used for their production and additives improving consumer characteristics of PLA and PHB based market products.

Photon-Momentum-Enabled Electronic Raman Scattering in Silicon Glass.

The nature of enhanced photoemission in disordered and amorphous solids is an intriguing question. A point in case is light emission in porous and nanostructured silicon, a phenomenon that is still not fully understood. In this work, we study structural photoemission in heterogeneous cross-linked silicon glass, a material that represents an intermediate state between the amorphous and crystalline phases, characterized by a narrow distribution of structure sizes.

Nature 4.0: A networked sensor system for integrated biodiversity monitoring.

Ecosystem functions and services are severely threatened by unprecedented global loss in biodiversity. To counteract these trends, it is essential to develop systems to monitor changes in biodiversity for planning, evaluating, and implementing conservation and mitigation actions. However, the implementation of monitoring systems suffers from a trade-off between grain (i.

Single-domain antibody delivery using an mRNA platform protects against lethal doses of botulinum neurotoxin A.

Single-domain antibodies (sdAbs, VHHs, or nanobodies) are a promising tool for the treatment of both infectious and somatic diseases. Their small size greatly simplifies any genetic engineering manipulations. Such antibodies have the ability to bind hard-to-reach antigenic epitopes through long parts of the variable chains, the third complementarity-determining regions (CDR3s).

rAAV expressing recombinant neutralizing antibody for the botulinum neurotoxin type A prophylaxis.

Botulinum neurotoxin (BoNT) is one of the most dangerous bacterial toxins and a potential biological weapon component. BoNT mechanism of pathological action is based on inhibiting the release of neurotransmitters from nerve endings. To date, anti-BoNT therapy is reduced to the use of horse hyperimmune serum, which causes many side effects, as well as FDA-approved drug BabyBig which consists of human-derived anti-BoNT antibodies (IgG) for infant botulinum treatment.

Structure, physicochemical properties, and adsorption performance of the ethyl cellulose/bentonite composite films.

Ethyl cellulose (EC) was filled with bentonite (Bent) particles by mechanical dispersion to produce composite film materials that were studied using various methods. According to X-ray diffraction (XRD) analysis, the inter-chain separation length was larger in EC/Bent composite then those in pure polymer. Infrared spectrometry indicated a formation of hydrogen bonds between the hydroxyl groups of EC and the silanol groups of clay.

Enhancing the Thermal Stability of Ionogels: Synthesis and Properties of Triple Ionic Liquid/Halloysite/MCC Ionogels.

In this study, an ionic liquid (IL), 1-butyl-3-methylimidazolium acetate, was used to prepare ionogels with microcrystalline cellulose (MCC) and halloysite (Hal). SEM, XRD, TG, DSC, FTIR spectroscopy, conductometry and mechanical tests were used to study the morphology, structure, thermal behaviour and electrophysical and mechanical characteristics of synthesised ionogels. XRD analysis showed a slight decrease in the interlayer space of halloysite in ionogels containing MCC, which may have been associated with the removal of residual water molecules resulting from hydrophilic IL anions and polymer macromolecules.

SARS-CoV-2 Seroprevalence Structure of the Russian Population during the COVID-19 Pandemic.

The SARS-CoV-2 pandemic, which came to Russia in March 2020, is accompanied by morbidity level changes and can be tracked using serological monitoring of a representative population sample from Federal Districts (FDs) and individual regions. In a longitudinal cohort study conducted in 26 model regions of Russia, distributed across all FDs, we investigated the distribution and cumulative proportions of individuals with antibodies (Abs) to the SARS-CoV-2 nucleocapsid antigen (Ag), in the period from June to December 2020, using a three-phase monitoring process. In addition, during the formation of the cohort of volunteers, the number of seropositive convalescents, persons who had contact with patients or COVID-19 convalescents, and the prevalence of asymptomatic forms of infection among seropositive volunteers were determined.

A Review of Insect Monitoring Approaches with Special Reference to Radar Techniques.

Drastic declines in insect populations are a vital concern worldwide. Despite widespread insect monitoring, the significant gaps in the literature must be addressed. Future monitoring techniques must be systematic and global.

Characterization of ultrafine particles emitted during laser-based additive manufacturing of metal parts.

Particulate matter (PM) emitted during laser additive manufacturing with stainless steel powder materials has been studied in detail. Three different additive manufacturing techniques were studied: selective laser melting, direct metal deposition and laser cladding. Gas flow and temperature fields accompanying the processes were numerically modeled for understanding particle growth and oxidation.

Synthesis, structure and thermal properties of montmorillonite/ionic liquid ionogels.

Sodium montmorillonite (Na-MMT) was synthesized as a result of two-stage processing of natural bentonite (Bent), and its particle-size distribution, structure and morphology were studied. It was found that the two-stage processing of the original clay resulted in a significant increase in the specific surface area (from 72 to 120 m g). The prepared Na-MMT powder was modified by two ionic liquids (ILs), namely, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMImNTf) and 1-butyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide (BMImNTf).

Camelid VHHs Fused to Human Fc Fragments Provide Long Term Protection Against Botulinum Neurotoxin A in Mice.

The bacterium is the causative agent of botulism-a severe intoxication caused by botulinum neurotoxin (BoNT) and characterized by damage to the nervous system. In an effort to develop novel immunotherapeutics, camelid single-domain antibodies (sdAbs, VHHs, or nanobodies) could be used due to their unique structure and characteristics. In this study, VHHs were produced using phage display technology.

Characterization of air contaminants emitted during laser cutting of carbon fiber-reinforced composite materials.

The emission of ultrafine carbonaceous particles during the laser cutting of fiber-reinforced polymer (CFRP) composite materials was investigated. The study was based on characterization of air contaminants emitted during laser cutting of an epoxy-based CFRP material with respect to particle size distribution, particle morphology, and chemical composition. Results indicate that about 90% of the total particulate mass is present as fine particulate matter with an aerodynamic cut-off diameter of 0.

Supplementation of specific carbohydrates results in enhanced deposition of chondrogenic-specific matrix during mesenchymal stem cell differentiation.

Repair or regeneration of hyaline cartilage in knees, shoulders, intervertebral discs, and other assorted joints is a major therapeutic target. To date, therapeutic strategies utilizing chondrocytes or mesenchymal stem cells are limited by expandability or the generation of mechanically inferior cartilage. Our objective is to generate robust cartilage-specific matrix from human mesenchymal stem cells suitable for further therapeutic development.

[POPULATION MORBIDITY BY INFECTIONS TRANSMITIED VIA IXODES PER- SULCATUS IN THE NORTH AND SOUTH OF IRKUTSK REGION].

Aim: Evaluate the degree of epidemic risk of emergence of tick-borne encephalitis (TBE) and ixodes ticks' borreliosis (ITB) in municipalities (MPs) of Irkutsk region with various natural- climate conditions.

Materials And Methods: Morbidity was compared for TBE and ITB during 2001 - 2015 in MPs of Irkutsk region located, to the north or south of the 55th parallel, i.e.

Neural Stem Cell Tumorigenicity and Biodistribution Assessment for Phase I Clinical Trial in Parkinson's Disease.

Human pluripotent stem cells (PSC) have the potential to revolutionize regenerative medicine. However undifferentiated PSC can form tumors and strict quality control measures and safety studies must be conducted before clinical translation. Here we describe preclinical tumorigenicity and biodistribution safety studies that were required by the US Food and Drug Administration (FDA) and Australian Therapeutic Goods Administration (TGA) prior to conducting a Phase I clinical trial evaluating the safety and tolerability of human parthenogenetic stem cell derived neural stem cells ISC-hpNSC for treating Parkinson's disease (ClinicalTrials.

Neural Stem Cells Derived from Human Parthenogenetic Stem Cells Engraft and Promote Recovery in a Nonhuman Primate Model of Parkinson's Disease.

Cell therapy has attracted considerable interest as a promising therapeutic alternative for patients with Parkinson's disease (PD). Clinical studies have shown that grafted fetal neural tissue can achieve considerable biochemical and clinical improvements in PD. However, the source of fetal tissue grafts is limited and ethically controversial.

[PLAGUE IN MANCHURIA (1910-1911) AND EBOLA VIRUS DISEASE IN WEST AFRICA (2014-2015): COMMON PREREQUISITES FOR THE DEVELOPMENT OF EPIDEMICS].

The paper gives the results of a comparative analysis of the prerequisites for the emergence and spread of epidemics of particularly dangerous infections, by using plague in Manchuria (1910-1911) and Ebola virus disease in West Africa (2014-2015) as examples. Analysis of literature and archival data and online information could reveal a number of common factors and conditions, which substantially contributed to the epidemics. Organization of anti-epidemic (preventive) measures in cases of the threatening epidemic spread, of particularly dangerous diseases must be based on the minimization, of the influence of the specific factors and conditions, which facilitate disease transmission in a given area in a given time.

[Molecular model of anthrax toxin translocation into target-cells].

Anthrax toxin is formed from three components: protective antigen (PA), lethal (LF) and edema (EF) factors. PA83 is cleaved by cell surface protease furin to produce a 63-kDa fragment (PA63). PA63 and LF/EF molecules are assembled to anthrax toxin complexes: oligomer PA63 x 7 + LF/EF x 3.

Proof of concept studies exploring the safety and functional activity of human parthenogenetic-derived neural stem cells for the treatment of Parkinson's disease.

Recent studies indicate that human pluripotent stem cell (PSC)-based therapies hold great promise in Parkinson's disease (PD). Clinical studies have shown that grafted fetal neural tissue can achieve considerable biochemical and clinical improvements in PD. However, the source of fetal tissue grafts is limited and ethically controversial.