Features of the Bioconversion of Pentacyclic Triterpenoid Oleanolic Acid Using Rhodococcus Actinobacteria

The ability of actinobacteria of the genus Rhodococcus to transform oleanolic acid (OA), a plant pentacyclic triterpenoid, was shown for the first time using bioresources of the Regional Specialized Collection of AlkanotrophicMicroorganisms (IEGM; WDCM #768;www.iegmcol.ru). The most promising strains (R.opacus IEGM 488 and R.rhodochrousIEGM 285) were selected, and these catalyzed80% bioconversion of OA (0.5 g/L) in the presence of n-hexadecane (0.1% v/v) for seven days. The process of OA bioconversion was accompanied by a gradual decrease in the culture medium pH. Adaptive responses of bacterial cells to the OA effects included the formation of compact cellular aggregates, a marked change in the surface-to-volume ratio of cells, and a significant increase in the Zeta potential values. The results demonstrated that the process of OA bioconversion was catalyzed by membrane-bound enzyme complexes. Participation of cytochrome P450-dependent monooxygenases in the oxidation of the OA moleculewas confirmedusing specific inhibitors. The obtained data expand our knowledge on the catalytic activity of actinobacteria of the genus Rhodococcus and their possible use as biocatalysts for the bioconversion of complex hydrophobic compounds. The results can also be used inthe searchfor promising OA derivatives to be used in the synthesis of biologically active agents. Keywords: bioconversion, oleanolic acid, Rhodococcus, biologically active compounds

Exploring the Mechanisms of Anti-Aβ42 Aggregation Activity of Walnut-derived Peptides using Transcriptomics and Proteomics in vitro

Inhibiting β-amyloid (Aβ) aggregation is of significance in finding potential candidates for Alzheimer’s disease (AD) treatment. Accumulating evidence suggests that nutrition is important for improving cognition and reducing AD risk. Walnut has been widely used as a functional food for brain health; however the underlying mechanisms remain unknown. Here, we investigated the molecular level alteration in Arctic mutant Aβ42 induced aggregation cell model by RNA-seq and iTRAQ approaches after walnut-derived peptides Pro-Pro-Lys-Asn-Trp (PW5) and Trp-Pro-Pro-Lys-Asn (WN5) interventions. PW5 or WN5 could significantly decrease abnormal Aβ42 aggregates. However, resultant alterations in transcriptome (substantially unchanged) were inconsistent with proteomic data (marked change). Proteomic analysis revealed 184 and 194 differentially expressed proteins unique to PW5 and WN5 treatment, respectively, for inhibiting Aβ42 protein production or increasing protein degradation via the mismatch repair pathways. Our study provides new insights into the effectiveness of food-derived peptides for anti-Aβ42 aggregation in AD.

Assessing Mottled Indications when Digitally Radiographing Austenitic Stainless Steel Welds

When radiographing an austenitic stainless steel weld with an appreciable weld deposit size, selecting a low radiographic kilovoltage (keV) can contribute to producing a radiographic indication that is not an imperfection. The contributors to this mottled condition are both radiographical and metallurgical. Electrons from low keV can diffract or absorb when penetrating through the dendritic grain structure of a weld. The increase in keV, or using gamma ray–equivalent isotopes, produces a marked change in electron output and penetration in material.

Evaluation of the Relationships between Intestinal Regional Lymph Nodes and Immune Responses in Viral Infections in Children

Viral infections increase the risk of developing allergies in childhood, and disruption of mucosal homeostasis is presumed to be involved. However, no study has reported a role for viral infections in such disruption. In this study, we clarified the mechanism of immunoglobulin A (IgA) overproduction in viral infections. Autopsies were performed on 33 pediatric cases, IgA and interferon (IFN)β levels were measured, and histopathological and immunohistochemical examinations were conducted. Furthermore, we cultured human cells and measured IFNβ and IgA levels to examine the effect of viral infections on IgA production. Blood IgA levels in viral infections were higher than in bacterial infections. Moreover, IFNβ levels in most viral cases were below the detection limit. Cell culture revealed increased IgA in gastrointestinal lymph nodes, especially in Peyer’s patches, due to enhanced IFNβ after viral stimulation. Conversely, respiratory regional lymph nodes showed enhanced IgA with no marked change in IFNβ. Overproduction of IgA, identified as an aberration of the immune system and resulting from excessive viral infection-induced IFNβ was observed in the intestinal regional lymph nodes, particularly in Peyer’s patches. Further, increased IgA without elevated IFNβ in the respiratory system suggested the possibility of a different mechanism from the gastrointestinal system.

Coumarin 153 Dynamics in Ethylammonium Nitrate: The Effects of Dilution with Methanol

Magic angle intensity decay and dynamic fluorescence anisotropy measurements were made on the binary solvent system composed of ethylammonium nitrate ([N2,0,0,0+][NO3−], EAN) + methanol (MeOH) across the complete EAN mole fraction range (xIL = 0–1) using the neutral dipolar solute coumarin 153 (C153) at 295 K. Stokes–Einstein–Debye (SED) hydrodynamic theory was used as a model framework to assess the C153 rotational reorientation dynamics. Departure from stick SED prediction was observed (in contrast to literature reports that used cationic or anionic dyes) and indicated a significant influence of domain nanoheterogeneity on probe dynamics. Steady-state spectroscopy indicated minimal changes in spectral peak and width with mole fraction, except at xIL = 0.3 where absorption widths decreased by ~170 cm−1, signaling that C153 sensed a change in solution heterogeneity. Magic angle intensity decays corroborated the steady-state observation and the excited-state lifetimes showed a marked change from xIL = 0.2–0.4 where EAN-EAN interactions became notably more significant. C153 average rotation times (⟨τrot⟩) showed significant solvent decoupling with increased EAN. The rotational data were fit to a power law dependence, ⟨τrot⟩ ∝ (ηT)p, where p = 0.82, demonstrating the presence of dynamic heterogeneity in the EAN/MeOH solutions. With increased EAN, rotation times showed that the heterogeneity became increasingly more significant since the rotation times systematically decreased away from the hydrodynamic stick limit.

Acute and sub-acute toxicity assessment of the standardized extract of Sanguisorba minor in vivo

Although Sanguisorba minor has been used as herbal medicine, no study has ever examined its potential toxicity. This study investigated acute and subacute toxicities of S. minor hydroalcoholic extract (SE). In the acute toxicity test, a single oral dose (300, 2,000, and 3,000 mg/kg) of SE was given to mice. The oral administration of SE (100, 200, and 400 mg/kg for 4 weeks) was performed to evaluate subacute toxicity. After the treatments, neurobehavioral, histopathology, hematological, and biochemical parameters were monitored. In vitro cytotoxicity was also assessed. Moreover, high-performance liquid chromatography fingerprint was done for the standardization of SE. The no-observed-adverse-effect level of SE was up to 2,000 mg/kg, and the LD50 of the prepared extract was over 3,000 mg/kg. The rats exposed to the extract did not show any marked change in their body weight. The extract at used doses did not affect neuromuscular coordination. According to the hematological, biochemical, and histological examinations, no significant treatment-related adverse effect of the extract was observed, even at 400 mg/kg. Only 48 h exposure to 400 μg/mL of SE reduced the viability of PC12 cells. The findings revealed that this plant could be well-tolerated, regarded safe, and used as herbal medicine.

Deglacial Land-Ocean Linkages at the Alaskan Continental Margin in the Bering Sea

A marine sediment record from the central Bering Sea, spanning the last 20 thousand years (ka), was studied to unravel the depositional history with regard to terrigenous sediment supply and biogenic sedimentation. Methodic approaches comprised the inference of accumulation rates of siliciclastic and biogenic components, grain-size analysis, and (clay) mineralogy, as well as paleoclimatic modelling. Changes in the depositional history provides insight into land-ocean linkages of paleoenvironmental changes. During the finale of the Last Glacial Maximum, the depositional environment was characterized by hemipelagic background sedimentation. A marked change in the terrigenous sediment provenance during the late Heinrich 1 Stadial (15.7–14.5 ka), indicated by increases in kaolinite and a high glaciofluvial influx of clay, gives evidence of the deglaciation of the Brooks Range in the hinterland of Alaska. This meltwater pulse also stimulated the postglacial onset of biological productivity. Glacial melt implies regional climate warming during a time of widespread cooling on the northern hemisphere. Our simulation experiment with a coupled climate model suggests atmospheric teleconnections to the North Atlantic, with impacts on the dynamics of the Aleutian Low system that gave rise to warmer winters and an early onset of spring during that time. The late deglacial period between 14.5 and 11.0 ka was characterized by enhanced fluvial runoff and biological productivity in the course of climate amelioration, sea-level rise, seasonal sea-ice retreat, and permafrost thaw in the hinterland. The latter processes temporarily stalled during the Younger Dryas stadial (12.9-11.7 ka) and commenced again during the Preboreal (earliest Holocene), after 11.7 ka. High river runoff might have fertilized the Bering Sea and contributed to enhanced upper ocean stratification. Since 11.0 ka, advanced transgression has shifted the coast line and fluvial influence of the Yukon River away from the study site. The opening of the Bering Strait strengthened contour currents along the continental slope, leaving behind winnowed sand-rich sediments through the early to mid-Holocene, with non-deposition occurring since about 6.0 ka.

Full protection against all four SARS-CoV-2 variants of concern (VOC) in hamsters requires revision of spike antigen used for vaccination.

Current licensed COVID-19 vaccines are based on antigen sequences of initial SARS-CoV-2 isolates that emerged in 2019. By mid 2021 these historical virus strains have been completely replaced by new cosmopolitan SARS-CoV-2 lineages. The ongoing pandemic has been further driven by emerging variants of concern (VOC) Alpha, Beta, Gamma and, lately predominant, Delta. These are characterized by an increased transmissibility and possible escape from naturally acquired or vaccine-induced immunity. We here show, using a YF17D-vectored first-generation COVID-19 vaccine (Sanchez-Felipe et al., 2021) and a stringent hamster challenge model (Abdelnabi et al., 2021) that the immunity elicited by a prototypic spike antigen is insufficient to provide optimal protection against the Beta VoC, urging for an antigenic update. We therefore designed an updated second-generation vaccine candidate that carries the sequence of a spike antigen that includes crucial epitopes from multiple VOCs. This vaccine candidate yielded a marked change in target antigen spectrum covered as demonstrated by (i) antigenic cartography and (ii) full protection against infection and virus-induced disease caused by any of the four VOCs (Alpha, Beta, Gamma and Delta) used for challenge. This more universal COVID-19 vaccine candidate also efficiently blocked direct transmission of VOC Delta from vaccinated infected hamsters to non-vaccinated sentinels under prolonged co-housing conditions. In conclusion, our data suggest that current first-generation COVID-19 vaccines need to be adapted to cover emerging sequence diversity of VOC to preserve vaccine efficacy and to contain virus spread at the community level.

Maori and education : an annotated list of New Zealand university theses 1977-1999

<p>This annotated list provides references to New Zealand university theses written within the timeframe, 1977-1999, that relate to the topic of Maori and education. The purpose of this work is to provide a comprehensive list of New Zealand university theses, within this period, that deal with any aspect of Maori and education in New Zealand. It is envisaged that this list of theses could be used as a reference tool for people interested in 'Maori education'. This topic has been the subject of a lot of postgraduate research in the past. There has been a marked change in emphasis in terms of the approach taken to research into Maori and education over the last few decades. This list of relevant theses attempts to document theses changes by providing annotated entries, which will describe the research undertaken, for theses written within this topic, 1977-1999.</p>

Maori and education : an annotated list of New Zealand university theses 1977-1999

<p>This annotated list provides references to New Zealand university theses written within the timeframe, 1977-1999, that relate to the topic of Maori and education. The purpose of this work is to provide a comprehensive list of New Zealand university theses, within this period, that deal with any aspect of Maori and education in New Zealand. It is envisaged that this list of theses could be used as a reference tool for people interested in 'Maori education'. This topic has been the subject of a lot of postgraduate research in the past. There has been a marked change in emphasis in terms of the approach taken to research into Maori and education over the last few decades. This list of relevant theses attempts to document theses changes by providing annotated entries, which will describe the research undertaken, for theses written within this topic, 1977-1999.</p>