Extended Downhole Protection by Preservative Biocides as Demonstrated in High Pressure, High Temperature Bioreactors

Preservative biocides are designed to control microbial growth and biogenic souring in the downhole environment. We report the prevention of biogenic souring by 4,4-dimethyloxazolidine (DMO, a preservative biocide) and glutaraldehyde as compared to that afforded by tributyl tetradecyl phosphonium chloride (TTPC, a cationic surface-active biocide), in a first-of-its kind suite of High Pressure, High Temperature (HPHT) Bioreactors that simulate hydraulically fractured shale reservoirs. The design of these new bioreactors, which recreate the downhole environment (temperatures, pressures, formation solids, and frac additives) in a controlled laboratory environment, enables the evaluation of biocides under field-relevant conditions. The bioreactors receiving either no biocide treatment or treatment with a high concentration of TTPC (50 ppm active ingredient) rapidly soured within the first two weeks of shut-in, and all surpassed the maximum detectable level of H2S (343 ppm) after the addition of live microbes to the reactors. Conversely, a higher loading of DMO (150 pppm active ingredient) maintained H2S concentrations below the minimum dectable level (5 ppm) for six weeks, and held H2S concentrations to 10.3 +/- 5.2 ppm after fifteen weeks of shut-in and two post shut-in microbial rechallenges. In a second study, a lower concentration of DMO (50 ppm active ingredient) maintained H2S concentrations below the minimum detectable level through the addition of live microbes after three weeks, and H2S concentrations only registered above 10 ppm upon a second addition of live microbes after five weeks. In this same study (which was performed at moderate temperatures), a 50 ppm (active ingredient) treatment of glutaraldehyde also maintained H2S concentrations below the minimum detectable level through the addition of live microbes after three weeks, and H2S concentrations registered 15.0 +/- 9.7 ppm H2S after four weeks. Similar time scales of protection are observed for each treatment condition through the enumeration of microbes present in each reactor. The differentiation in antimicrobial activity (and specifically, prevention of biogenic souring) afforded by DMO and glutaraldehyde suggests that such nonionic, preservative biocides are a superior choice for maintaining control over problematic microorganisms as compared to surface-active biocides like TTPC at the concentrations tested. The significant duration of efficacy provided by DMO and glutaraldehyde in this first-of-its-kind suite of simulated reservoirs demonstrates that comprehensive preservation and prevention of biogenic souring from completion through to production is feasible. Such comprehensive, prolonged protection is especially relevant for extended shut-ins or drilled but uncompleted wells (DUCS) such as those experienced during the COVID-19 pandemic. The environment simulated within the bioreactors demonstrates that the compatibility afforded by a preservative biocide offers downhole protection that cationic, surface-active biocides do not.

Side effects and Immunogenicity following administration of the Sputnik V COVID-19 vaccine in health care workers in Iran

The Sputnik V is a COVID- 19 vaccine developed by the Gamalia institute of epidemiology and microbiology and released on August 11, 2020. We provided independent evidence on side effects and immunogenicity following the administration of the Sputnik V COVID-19 in Iran. In this observational study, the healthcare workers who were vaccinated with the Sputnik V COVID-19 vaccine within February and April 2021 were evaluated. Among a total of 13,435 vaccinated healthcare workers, we received 3236 self-declaration reports of Sputnik V associated adverse events with the mean age 39.32 ± 10.19 years old which 38.8% were men and 61.2% were women. Totally 68.8% of females versus 66.2% of males reported side effects after receiving the first dose and 31.2% of females versus 33.8% of males reported side effects after the second dose of vaccine. The most common side effect was a pain in the injection site (56.9%), fatigue (50.9%), body pain (43.9%), headache (35.7%), fever (32.9%), joint pain (30.3%), chilling (29.8%) and drowsiness (20.3%). Side effects of the vaccine were significantly more frequent in females and younger individuals. Among a total of 238 participants, more than 90% after the first and second dose of vaccine had a detectable level of SARS-CoV-2 RBD antibody and SARS-CoV-2 neutralizing antibody. Although the overall rate of adverse effects was higher than the interim results from randomized controlled trials, our findings support the manufacturer’s reports about the high humoral immunogenicity of vaccine against COVID-19.

Phenological and Geographical Effects on Phenolic and Triterpenoid Content in Vaccinium vitis-idaea L. Leaves

Lingonberry leaves have been proposed as a potential raw material for nutraceutical products and functional food due to the richness of phenolic and triterpenic compounds. However, contents of these bioactive compounds tend to vary greatly with physiological, climatic, and edaphic conditions, resulting in lingonberry leaves’ nutritional-pharmaceutical quality changes. In this context, we examined the effects of seasonal and geographical factors on phenolic and triterpenoid contents in lingonberry leaves. Quantitative and qualitative differences between samples were determined using validated HPLC-PDA methods. A total of 43 bioactive compounds were found at a detectable level throughout the year in young and old lingonberry leaves, with the highest contents of most compounds observed in samples collected in autumn–first half of spring. This suggests the potential to exploit the continuous biosynthesis for a longer harvesting season. Considerable variations in phytochemical profiles of lingonberry leaves, obtained from 28 locations in Lithuania, were found. Correlation analyses revealed significant negative correlations between contents of particular constituents and sunshine duration, temperature, and precipitation, and positive correlation with air humidity, longitudes, and altitudes of collecting locations and macronutrients in soil. These results suggest that harsh weather is favorable for most identified compounds and it may be possible to achieve appropriate accumulation of secondary metabolites by adjusting edaphic conditions. Taken together, the accumulation of phenolics and triterpenoids in lingonberry leaves highly depends on phenological and geographical factors and the influence of both variables differ for the particular compounds due to different metabolic processes in response to stresses.

Analysis of over-the-counter analgesics purported to contain mescaline from the peyote cactus (Lophophora williamsii: Cactaceae)

The purpose of this study was to investigate samples of commercial over-the-counter products purported to contain extracts from peyote cactus (Lophophora williamsii), a vulnerable species. Samples were extracted with organic solvent and then washed to remove impurities. The extracts of these products were subjected to an analysis by real-time mass spectrometry (DART-MS) to determine the presence or absence of the alkaloid mescaline (3,4,5-trimethoxyphenethylamine). High-performance liquid chromatography (HPLC) was used to determine mescaline concentrations in the samples and to provide quantitative evidence of the concentration—if any—of mescaline in the products. If a detectable level of mescaline—a stable and abundant alkaloid of L. williamsii—was found in a given extract, then it was inferred that L. williamsii was present in the corresponding topical product. The results of this investigation show that most consumers who purchase the products in question are being defrauded if they believe they are buying L. williamsii-based medicines. The lack of mescaline—implying the lack of peyote—in these products suggests that wild populations of the vulnerable cactus L. williamsii, though currently being decimated on a massive scale in Mexico and the U.S. for other purposes, are rarely harvested for use in topical analgesic products. This conclusion is based on the finding that less than 5% of the ostensible L. williamsii-containing topical analgesic products that were analyzed in this study actually contained mescaline.

Reduction of Salmonella Enteritidis in Fish by Microwave Cooking

The effect of microwave cooking on the survival of Salmonella Enteritidis was investigated. Inoculated whiting and salmon fillets (6-7 log cfu/cm2) were cooked in microwave either packed or unpacked at two internal temperatures (50 and 70°C). When the samples were cooked up to the internal temperature of 50°C, the reductions were 1.82 log cfu/cm2 (29%) for packed and 0.69 log cfu/cm2 (11%) for unpacked whiting. For the same cooking temperature, the reductions were 2.39 (33%) and 0.73 log cfu/ cm2 (10%) for packed and unpacked salmon, respectively. When the internal temperature was 70°C, the reductions in S. Enteritidis counts were 2.89 (45%) and 3.90 cfu/cm2 (54%) unpacked whiting and salmon, respectively. However, the reductions were higher in packed samples of both fish cooked to 70C internal temperature than that of unpacked samples and counts of the pathogen were below the detectable level (<1.00 log cfu/cm2 ). These results suggested that packaging increased the S. Enteritidis reduction during microwave cooking and the reductions were higher in salmon than that of whiting. Microwave-cooking instructions must be included in the MW operating manuals. The foods must be cooked in microwave not lower than 360 W and 70°C.

GROUNDWATER QUALITY IN BIRATNAGR OF MORANG DISTRICT, NEPAL

A study was conducted to assess the groundwater quality in Biratnagar of Morang district of Nepal on the basis of some important physicochemical and microbiological analysis. During the study, the elevated value of turbidity ranged from 2.1±2.80 NTU (ward no. 8) to 81.46±44.28 NTU (ward no. 10), free-carbondioxide (FCO2) ranged from 12±2.45 mg /L (ward no. 21) to 17.2±3.03 mg/L (ward no. 8), arsenic ranged from nil (ward no. 3) to 0.17±0.21 mg /L (ward no. 1), iron (Fe) ranged from 0.45 mg/L (ward no. 7) to 3.67 mg/L (ward no. 4), manganese (Mn), ranged from 0.45 mg/L (ward no. 7) to 5.99 mg/L (ward no. 16) and fecal coliform bacteria were found positive in 10 wards (ward nos. 2, 3, 4, 9, 10, 11,14,15,20 and 21) constituting 45.45% of the total samples ranging from 3 to 25 MPN/100 ml . Out of the total analyzed samples, turbidity in 78 samples (70.90%), FCO2, Fe, and Mn in all samples (100%) and arsenic in 37 water samples (33.64 %) were crossed the permissible limit of WHO guideline. However, the value of pH, EC, DO, TH, PO4-P, NO3-N, Cd, Zn, and Pb were below the WHO guideline value. The status of fluoride was below detectable level in all the analyzed groundwater samples.

Rapid Inactivation In Vitro of SARS-CoV-2 in Saliva by Black Tea and Green Tea

Saliva plays major roles in the human-to-human transmission of SARS-CoV-2. If the virus in saliva in SARS-CoV-2-infected individuals can be rapidly and efficiently inactivated by a beverage, the ingestion of the beverage may attenuate the spread of virus infection within a population. Recently, we reported that SARS-CoV-2 was significantly inactivated by treatment with black tea, green tea, roasted green tea and oolong tea, as well as their constituents, (-) epigallocatechin gallate (EGCG), theasinensin A (TSA), and galloylated theaflavins. However, it remains unclear to what extent tea inactivates the virus present in saliva, because saliva contains various proteins, nitrogenous products, electrolytes, and so on, which could influence the antivirus effect of tea. Here, we assessed whether tea inactivated the SARS-CoV-2 which was added in human saliva. A virus was added in healthy human saliva in vitro, and after treatment with black tea or green tea, the infectivity of the virus was evaluated by TCID50 assays. The virus titer fell below the detectable level or less than 1/100 after treatment with black tea or green tea for 10 s. The black tea-treated virus less remarkably replicated in cells compared with the untreated virus. These findings suggest the possibility that the ingestion of tea may inactivate SARS-CoV-2 in saliva in infected individuals, although clinical studies are required to determine the intensity and duration of the anti-viral effect of tea in saliva in humans.

Contamination of Slovak Bilberry (Vaccinium Myrtillus L.) with Radiocaesium 137Cs in Selected Slovak Locations

The aim of this study was to determine the activity of post-Chernobyl 137Cs in Slovak bilberry (Vaccinium myrtillus L.) from selected locations of Slovakia depending upon: the season, location and the soil-plant transfer factor (TF). The 137Cs activity was determined in samples of forest soil and bilberry bushes (stems, leaves and fruits) growing on the soil in three locations: Arboretum Mlyňany (1), Hodruša-Hámre (2) and Javorníky (3). Altogether we collected 35 samples; namely 15 samples from Arboretum Mlyňany, 10 samples from Hodruša-Hámre and 10 from Javorníky. The samples of soil were examined also for the activity of 40K. The samples were collected in the spring, summer and autumn in the years 2019 and 2020 and were analysed by a gamma-ray spectrometry method. The highest levels of 137Cs activity concentrations were determined in Hodruša-Hámre in September where they reached 161 ± 13 Bq.kg−1 in the soil, 3.95 ± 1.07 Bq.kg−1 in the stems and 14.7 ± 4.26 Bq.kg−1 in the leaves. The lowest levels were determined in the Arboretum Mlyňany in October where the 137Cs activity in the soil reached 13.1 ± 1 15 Bq.kg−1, while in the stems, leaves and fruits it was lower than the minimum detectable level. In the latter location, we also determined the highest activity of 40K, the radioactive isotope physiologically and metabolically similar to 137Cs. The mass activity of 137Cs in all samples of bilberries were lower than the minimum detectable activity (MDA). The comparison of the results obtained in this study with the limit for total mass activity of radiocaesium (134Cs + 137Cs) in the food (600 Bq.kg−1) allowed us to conclude that the fruits, stems and leaves of Slovak bil-berries present neither health nor environmental risk.

High Pressure, High Temperature Bioreactors as a Biocide Selection Tool for Hydraulically Fractured Reservoirs

We report the design, operation and biogenic souring data from a first-of-its kind suite of High Pressure, High Temperature (HPHT) Bioreactors for hydraulically fractured shale reservoirs. These bioreactors vet the ability of microbial control technologies, such as biocides, to prevent the onset of microbial contamination and reservoir souring at larger experimental volumes and higher pressures and temperatures than have been previously possible outside of field trials. The bioreactors were charged with proppant, crushed Permian shale, and sterile simulated fracturing fluids (SSFF). Subsets of bioreactors were charged with SSFF dosed with either no biocide, tributyl tetradecyl phosphonium chloride (TTPC, a cationic surface-active biocide), or 4,4-dimethyloxazolidine (DMO, a preservative biocide). The bioreactors were shut in under 1,000-2,500 psi and elevated temperatures for up to fifteen weeks; hydrogen sulfide (H2S) and microbial counts were measured approximately once per week, and additional microbes were introduced after weeks three and five. Across two separate studies, the bioreactors containing no biocide soured within the first week of shut-in and H2S concentrations increased rapidly beyond the maximum detectable level (343 ppm) within the first three to six weeks of shut-in. In the first study, the bioreactors treated with TTPC soured within two weeks of shut-in (prior to the first addition of fresh microbes), and H2S concentrations increased rapidly to nearly 200 ppm H2S within the first six weeks of shut-in and beyond the maximum detectable level after fifteen weeks of shut-in. The bioreactors containing DMO did not sour during either study until at least the first addition of fresh microbes, and higher levels of the preservative biocide continued to prevent the biogenic formation of H2S even during and after the addition of fresh microbes. Microbial counts correlate with the H2S readings across all bioreactor treatments. The differentiation in antimicrobial activity afforded by the different types of biocide treatments validates the use of these simulated laboratory reservoirs as a biocide selection tool. This first-of-its-kind suite of HPHT Bioreactors for hydraulic fracturing provides the most advanced biocide selection tool developed for the hydraulic fracturing industry to date. The bioreactors will guide completions and stimulation engineers in biocide program optimization under reservoir-relevant conditions prior to beginning lengthy and expensive field trials.

Polarized kilonovae from black hole–neutron star mergers

ABSTRACT We predict linear polarization for a radioactively powered kilonova following the merger of a black hole and a neutron star. Specifically, we perform 3D Monte Carlo radiative transfer simulations for two different models, both featuring a lanthanide-rich dynamical ejecta component from numerical-relativity simulations while only one including an additional lanthanide-free disc-wind component. We calculate polarization spectra for nine different orientations at 1.5, 2.5, and 3.5 d after the merger and in the $0.1\!-\!2\, \mu$m wavelength range. We find that both models are polarized at a detectable level 1.5 d after the merger while show negligible levels thereafter. The polarization spectra of the two models are significantly different. The model lacking a disc wind shows no polarization in the optical, while a signal increasing at longer wavelengths and reaching $\sim 1\!-\!6{{\ \rm per\ cent}}$ at $2\, \mu$m depending on the orientation. The model with a disc-wind component, instead, features a characteristic ‘double-peak’ polarization spectrum with one peak in the optical and the other in the infrared. Polarimetric observations of future events will shed light on the debated neutron richness of the disc-wind component. The detection of optical polarization would unambiguously reveal the presence of a lanthanide-free disc-wind component, while polarization increasing from zero in the optical to a peak in the infrared would suggest a lanthanide-rich composition for the whole ejecta. Future polarimetric campaigns should prioritize observations in the first ∼48 h and in the $0.5\!-\!2\, \mu$m range, where polarization is strongest, but also explore shorter wavelengths/later times where no signal is expected from the kilonova and the interstellar polarization can be safely estimated.