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Given the medical and social significance of Helicobacter pylori infection, timely and reliable diagnosis of the disease is required. The traditional invasive and non-invasive conventional diagnostic techniques have several limitations. Recently, opportunities for new diagnostic methods have appeared based on the recent advance in the study of H. pylori outer membrane proteins and their identified receptors. In the present study we assess the way in which outer membrane protein-cell receptor reactions are applicable in establishing a reliable diagnosis. Herein, as well as in other previous studies of ours, we explore the reliability of the binding reaction between the best characterized H. pylori adhesin BabA and its receptor, the blood antigen Leb. For the purpose we developed surface plasmon resonance (SPR) and double resonance long period grating (DR LPG) biosensors based on the BabA-Leb binding reaction for diagnosing H. pylori infection. In SPR detection, the sensitivity was estimated at 3000 CFU/mL-a much higher sensitivity than that of the RUT test. The DR LPG biosensor proved to be superior in terms of accuracy and sensitivity-concentrations as low as 102 CFU/mL were detected.

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One of the first clinical observations related to COVID-19 identified hematological dysfunctions. These were explained by theoretical modeling, which predicted that motifs from SARS-CoV-2 structural proteins could bind to porphyrin. At present, there is very little experimental data that could provide reliable information about possible interactions. The surface plasmon resonance (SPR) method and double resonance long period grating (DR LPG) were used to identify the binding of S/N protein and the receptor bind domain (RBD) to hemoglobin (Hb) and myoglobin (Mb). SPR transducers were functionalized with Hb and Mb, while LPG transducers, were only with Hb. Ligands were deposited by the matrix-assisted laser evaporation (MAPLE) method, which guarantees maximum interaction specificity. The experiments carried out showed S/N protein binding to Hb and Mb and RBD binding to Hb. Apart from that, they demonstrated that chemically-inactivated virus-like particles (VLPs) interact with Hb. The binding activity of S/N- and RBD proteins was assessed. It was found that protein binding fully inhibited heme functionality. The registered N protein binding to Hb/Mb is the first experimental fact that supports theoretical predictions. This fact suggests another function of this protein, not only binding RNA. The lower RBD binding activity reveals that other functional groups of S protein participate in the interaction. The high-affinity binding of these proteins to Hb provides an excellent opportunity for assessing the effectiveness of inhibitors targeting S/N proteins.

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The danger of the emergence of new viral diseases and their rapid spread demands apparatuses for continuous rapid monitoring in real time. This requires the creation of new bioanalytical methods that overcome the shortcomings of existing ones and are applicable for point-of-care diagnostics. For this purpose, a variety of biosensors have been developed and tested in proof-of-concept studies, but none of them have been introduced for commercial use so far. Given the importance of the problem, in this study, long-period grating (LPG) and surface plasmon resonance (SPR) biosensors, based on antibody detection, were examined, and their capabilities for SARS-CoV-2 structural proteins detection were established. Supersensitive detections of structural proteins in the order of several femtomoles were achieved by the LPG method, while the SPR method demonstrated a sensitivity of about one hundred femtomoles. The studied biosensors are compatible in sensitivity with ELISA and rapid antigen tests but, in contrast, they are quantitative, which makes them applicable for acute SARS-CoV-2 infection detection, especially during the early stages of viral replication.

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This Study describes eleven patients positive for severe acute respiratory syndrome coronavirus 2. In our cases, females and younger patients developed more severe disease. In contrast, improvement in left ventricular ejection fraction and N-terminal prohormone brain natriuretic peptide within the first week of treatment contributed to promising outcomes.

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The Caspian Sea is the largest land-locked lake in the world that includes numerous endemic species. Because of its enclosed nature, the pollutants entering this water body become entrapped. The present paper examines the influence of human activity and beach morphology on the abundance and distribution of stranded plastic debris along the Caspian Sea coastlines. It would be possible by relating some characteristics of these beaches (population, urbanization, substrate type, and slope of beaches) with the abundance of plastic debris through a PCo analysis. The results showed that in our study area, the most effective factors on plastic debris distribution were urbanization and population followed by the slope and substrate of beaches. Three size classes of plastic debris were defined as "large microplastic" (1 to < 5 mm), "mesoplastic" (5 to < 25 mm), and "macroplastic" (> 25 mm). The density of the large microplastic, mesoplastic, and macroplastic materials on the Caspian Sea coastline was 8.43 ± 0.54, 8.74 ± 0.42, and 7.53 ± 0.30 particles/m2, respectively. Foam was the most abundant microplastic debris along the study area (47.58%), followed by resin pellets (33.93%) and fragments (16.30%), respectively. We also selected the Boujagh National Park with limited accessibility as an appropriate area for the study of marine debris as one sampling station. Cigarette butts and film pieces displayed a different distribution pattern compared to other debris types in the Boujagh National Park station likely due to their distinct buoyancy specification.

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Straight-chain alkanes (n-alkanes) have been proposed as biomarkers to assess petroleum pollution sources in marine environments. In this work, three sampling sites were selected along Iranian-protected mangrove forests in the Persian Gulf. Sample sites were chosen to represent different compositions and sources of n-alkanes in surface sediments (0-5 cm) from different locations in the Khamir Port, in the middle part of the Gulf, and in the Qeshm Island. Samples were analyzed by gas chromatography-mass spectrometry (GC-MS), and the obtained n-alkanes concentrations were analyzed by principal component analysis (PCA) and multivariate curve resolution alternating least squares (MCR-ALS) to deduce their possible sources and distribution patterns. Results revealed that n-alkanes have a dominant biogenic source in marginal Qeshm Island stations, which changed from biogenic to petrogenic sources in the Khamir Port areas. Sediment samples from the Khamir Port showed the significant presence of oil pollution due to transportation. These samples are being exposed to basic Persian Gulf currents entering from the Hormuz Strait causing oil pollution spread over the entire Gulf area. Sediment samples of the Middle Part stations located between two other sites show a combined condition of the two previous sections, with petrogenic and biogenic contributions. The present study demonstrates that the Hara Protected Area was already contaminated by background oil pollution as a result of continuous oil spills and war conflicts in the Persian Gulf.Additionally, the MCR-ALS method is shown to be a powerful chemometric tool for the investigation, resolution, identification, and description of pollution patterns distributed over a particular geographical area and environmental compartment. They can be used as well as parameters like unresolved to resolved ratio (U/R), pristane to phytane (Pr/Ph), n-C17/Pr, n-C18/Ph, and unresolved complex mixture (UCM) to assess petroleum pollution sources in the sediments.

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This study is the first detailed ecotoxicological study of the annulated sea snake, Hydrophis cyanocinctus. Concentrations of lead, cadmium, nickel and vanadium were evaluated in muscle, liver, kidney, skin and blood of the annulated sea snake (H. cyanocinctus) and in the whole bodies of its main prey species (Periophthalmus waltoni and Boleophthalmus dussumieri) in the Hara Protected Area, the Persian Gulf. The mean concentrations of lead and vanadium were highest in the kidney, which identified the kidney as a target organ for metals in sea snakes as it is in other reptilian groups. Mean concentrations of cadmium and nickel were highest in the liver and skin, respectively. Mean cadmium concentrations were significantly higher in the liver compared to prey species, which indicated that prey items may be a source of cadmium for the annulated sea snake in the study area. Data presented here may be considered as a baseline for further ecotoxicological studies in sea snakes.

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