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Chlorophyll extracted from Mangifera indica leaves in acetone (80%) has been explored for its feasibility as a radiation dosimeter in therapeutic X-rays. The UV−VIS spectroscopic analysis of the irradiated samples shows a decrease in optical density at 664 nm with an increase in the X-ray dose. A linear response has been observed up to 2 Gy (Pearson’s correlation coefficient is 0.90), and a supralinear trend thereafter. The dosimeter has been found to be energy dependent and dose rate independent. The chlorophyll molecule has shown the potential to be used as a radiation dosimeter.

Lutein and zeaxanthin (L/Z), xanthophylls obtained from the diet, are deposited in the macula of the eye. The macular concentration of L/Z is quantifiable as macular pigment optical density (MPOD). The aim of this review was to critically appraise the effect on MPOD of increasing L/Z intake by dietary intervention in adults. Pubmed, Cochrane Library, Web of Science, and Cinahl were searched up to April 2020. Ten studies investigating populations with and without age-related macular degeneration were included. MPOD increased significantly in 2 of the 8 controlled studies. Studies varied largely in the prescribed dietary L/Z dosage, duration, and participant characteristics. No relationships between types of dietary L/Z interventions and MPOD response could be determined. Limited monitoring of habitual dietary L/Z intake was identified as a major limitation of all 10 studies. Habitual dietary L/Z intake should be closely monitored in future studies to account for their effects on MPOD response to dietary L/Z interventions.

Lutein, zeaxanthin, and meso-zeaxanthin are the only carotenoids found in the human macula and may have a role in visual function. These carotenoids are reported to protect the retina, and thus vision, as antioxidants and by acting as a blue light filter. Our objective was to determine a minimum concentration of lutein/zeaxanthin intake that is associated with a statistically significant and/or clinically important change in macular pigment optical density (MPOD) among adults with healthy eyes. We searched Ovid MEDLINE, CENTRAL, and the Commonwealth of Agriculture Bureau for English-language studies through to July 2020. Two reviewers screened results to identify studies that evaluated supplements or dietary sources of lutein/zeaxanthin on MPOD among adults with healthy eyes. One reviewer extracted data and assessed strength of evidence, which was confirmed by a second reviewer. Two independent reviewers assessed the risk of bias. Meta-analyses were stratified by total lutein/zeaxanthin dose. We included 46 studies (N = 3189 participants; mean age = 43 y; 42% male). There was no statistically significant change in MPOD among studies evaluating, Statement of Significance: We conducted a systematic review to determine the quantities of lutein/zeaxanthin intake from either dietary or supplemental sources that are associated with macular pigment optical density (MPOD) among adults with healthy eyes. We concluded that >10 mg/d of lutein/zeaxanthin can increase MPOD, but the effects at doses

Background and Aim: Different Candida species isolated in humans and animals have different types of parasite activity. The most pathogenic species is Candida albicans followed by Candida tropicalis. However, the effects of the morphology of Candida krusei, Candida guilliermondii, and Candida glabrata biofilms on the pathogenicity of these species have not been fully characterized. To the best of our knowledge, there is no literature on the effect of farnesol on rare Candida species. This study aimed to check the effect of different farnesol concentrations on the species C. krusei, C. guilliermondii, and C. glabrata compared with the strain C. albicans ATCC 10231, which has been widely studied, and is a strong producer of biofilms. Materials and Methods: We studied the morphological and densitometric parameters of biofilms produced by Candida species under the influence of the drug farnesol (Sigma-Aldrich, St. Louis, MO). We used a heart brain broth with the addition of 2% bovine blood serum in 96-well plates. To each well, we added 100 μL of C. albicans, C. krusei, C. guilliermondii, or C. glabrata culture, and 0.2-400 μM farnesol. The microliter plates were cultured with the lid closed at 37°C for 48 h. Then, the liquid was removed, and the wells were washed 3 times with 200 μL phosphate buffer solution (pH 7.3). Biofilm fixation was performed using 150 μL of 96% ethanol for 15 min. Then, the microliter plates were dried for 20 min at 37°C, a 0.5% solution of crystalline violet was added, and the plates were placed in an incubator at 37°C. After 5 min, the contents of the wells were removed, washed 3 times with 200 μL of phosphate buffer solution (pH 7.2), and dried. The dye was extracted by washing with 200 μL of 96% ethanol for 30 min. The results were obtained using a photometric analyzer of enzyme immunoassay reactions at an optical density (OD) wavelength of 450 nm. Results: All of Candida spp. strains tested were susceptible to farnesol at concentrations ranging from 0.8 to 400 μM for C. albicans, C. krusei, and C. guilliermondii, and 12.5 to 400 μM for C. glabrata. Conclusion: This study provides new insights into the use of farnesol against biofilms produced by Candida species, but further studies in vivo are necessary to evaluate the effectiveness of the reduction of OD. To the best of our knowledge, the antimicrobial activity of farnesol against C. krusei, C. guilliermondii, and C. glabrata has not been reported previously, although studies have confirmed the inhibitory effect of farnesol on the growth of different microorganisms.

Structural features of films and fibers obtained from mixtures of a chitosan solution in acetic acid with an ethanol and NaOH solution were investigated. Phase separation in the system that included chitosan, acetic acid, ethanol, NaOH and water was studied using scanning electron microscopy and time dependence of optical density. Optical densities of the mixtures were measured at λ = 330 nm. Structural studies involved two types of films: (a) the samples obtained from the mixtures of the chitosan solutions and various precipitants by lyophilization; and (b) the samples obtained by drying at room temperature. It was demonstrated that the most stable structure is formed upon the mixing of the chitosan solution with the ethanol–alkali mixture. Chitosan fibers prepared by wet spinning had the following characteristics: tensile strength σ = 188 ± 9.1 МPа; Young’s modulus E = 11.5 ± 0.6 GPа; tensile strain ε = 4.8 ± 0.6%.

The study was conducted to evaluate the culture and growth performance of spirulina (Spirulina platensis) in supernatant of three different amounts of digested rotten potato (DRP), and Kosaric medium (KM) as control in 16 days after 26 days digestion. Three different concentrations such as 20, 40 and 60% of DRP were used. Spirulina was inoculated in supernatant DRP along with 9.0 g/L NaHCO3 and micronutrients, and KM for a period of 14 days. The cell weight of spirulina was attained a maximum of 12.42 ± 0.21 mg/L in KM followed by 8.352 ± 0.21, 6.256 ± 2.34 and 9.505 ± 0.43 mg/L in supernatant of 40, 20 and 60% DRP, respectively on the 10th day of culture. Similar trend was also observed in the cases of optical density, chlorophyll a, total biomass, specific growth rates. Cell weight of spirulina grown in the media were highly significant (p

Introduction: Cataract surgery has been reported as a long-term risk of reduced macular pigment optical density (MPOD). This study investigated changes in MPOD in pseudophakic patients after lutein supplementation. Methods: Fifty-seven patients who had no ocular diseases and underwent cataract surgery with concurrent implantation of clear intraocular lenses were included. MPOD was measured before lutein supplementation and every week during 6 weeks of supplementation. Two additional measurements were conducted after the end of supplementation. Results: Compared with baseline, MPOD was increased after 1 week of supplementation (p < 0.01) and remained elevated after cessation of supplementation. After 3 weeks of supplementation, MPOD in females was higher than that in males (p < 0.05). Compared with patients at the highest quintile baseline MPOD, patients of both genders at the lowest quintile had significant increases after 6 weeks of supplementation (p < 0.05). Conclusion: MPOD increased after lutein supplementation in patients who had undergone cataract surgery. With the same amount of lutein supplementation, MPOD increased more in patients with low MPOD at baseline; it also increased more in females than in males. Lutein supplementation is presumed to support increased MPOD, which can reduce the risk of age-related macular degeneration, especially in females with low MPOD.

Sunscreens are used to protect human skin against harmful UV radiation. Today there is a trend towards high sun protection factors (SPF) and good UVA protection. Methods for the assessment of SPF and UVA protection involve irradiation of the product, and the photostability properties of the sunscreen have an influence on its performance. Sunscreens often contain more than one UV filter. Some photolabile UV absorbers may be stabilized by the presence of other photostable UV-absorbers. Stabilization can be achieved just by a certain optical density due to the presence of such UV-filter substances. However, photostabilization may also be caused by quenching mechanisms, such as singlet-singlet or triplet-triplet energy transfer. Investigation of butyl methoxy dibenzoylmethane and ethylhexyl methoxycinnamate as photolabile sunscreens in the presence of either octocrylene or bis ethylhexyloxyphenol methoxyphenyl triazine showed that both mechanisms may apply. With the systems butyl methoxy dibenzoylmethane plus octocrylene and ethylhexyl methoxycinnamate plus bis ethylhexyloxyphenol methoxyphenyl triazine the quenching mechanism appears to be predominant.

Flex barrier and optical density (OD) are two unique properties for metallized films and aluminum foil. This study investigated the effect of flexing on barrier properties of a laminate comprising metallized films and aluminum foil, as well as OD and adhesive lamination process on the overall multilayer laminate performance. Three (3) barrier layers, namely aluminum foil, metallized polyethylene terephthalate (met OPET) film with a high OD, and standard metallized PET film(met OPET), were laminated with the same printing layer OPET and sealing layer linear low density polyethylene (LLDPE), into OPET/adhesive/foil/adhesive/LLDPE and OPET/adhesive/met OPET/adhesive/LLDPE structures. The oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) were measured before and after flexing. The aluminum foil centered laminate had an excellent oxygen barrier after the 20-cycle flexing test and failed to retain its oxygen barrier after the 270-cycle flexing. Compared to the aluminum foil centered laminate, the metallized film centered laminates were less affected by the flexing on the oxygen barrier. For all laminates, the water vapor barrier was less severely affected by flexing than the oxygen barrier. This study suggests that the ASTMF392 Gelbo D (20- cycle flexing) can determine if aluminum foil and metallized film centered laminates are resistant to flex-formed pinhole failures. A higher OD, a thicker film thickness and lamination process improved laminate’s actual barrier, resulting in lower measured transmission rates versus that predicted using Henry's solubility law and Fick's diffusion law. The laminate’s water vapor transmission rate is 55–74% lower than predicted. The oxygen transmission rate is 15–31% lower than predicted.

In the production of low-alcohol and non-alcoholic beverages, the use of preservatives is allowed, including benzoic acid (BК) and its salts. Standard methods based on high performance liquid chromatography are used to control the content of this preservative. This work presents the results on the determination of benzoic acid in samples of low-alcohol and non-alcoholic products by the spectrophotometric method. Research has been carried out to establish the optimal wavelength when measuring the optical density of benzoic acid solutions. A calibration characteristic has been constructed to determine the mass concentration of benzoic acid, which makes it possible to determine its concentration in the range from 10 mg/dm3 to 500 mg/dm3 of benzoic acid, taking into account dilution. Metrological data have been obtained for constructing a calibration characteristic for the determination of benzoic acid in low-alcohol and non-alcoholic products. It is shown that the results of the determination of this preservative in the indicated products by the spectrophotometric method are comparable with the analogous results obtained using standard methods based on high performance liquid chromatography. The research results became the basis for the developed Methodology for measuring the mass concentration of sorbic and benzoic acids in low-alcohol and non-alcoholic products by the spectrophotometric method. The developed technique allows measuring the mass concentration of benzoic acid in low-alcohol and non-alcoholic products containing only benzoic acid. The spectrophotometric method for determining the mass concentration of BA is a less costly method for determining this preservative in a product than the currently used method of high-performance liquid chromatography, does not require special expensive equipment, additional consumables and specially trained personnel..

Tea as a refreshing beverage is consumed socially and habitually. Tea contains several bioactive compounds. The present research work has been designed to work on characterization of tea and tea infusion collected from major tea growing regions of India as climate influences aroma and taste of tea. CTC-tea and Orthodox-tea (O-tea) samples were collected from different tea growing regions of India. In both the type of tea samples maximum and minimum percentage of moisture were recorded in Nilgiri and Dooars tea. Amount of Crude fibres in manufactured CTC-tea was more than O-tea. Ash content of CTC-tea and O-tea ranged between 1.308%-1.66% and 0.233-0.315% respectively. The pH of infusions was found to be acidic. Optical density of O-tea infusions was found to be less than CTC-tea infusions. Insoluble and soluble matter in tea infusions was extremely variable. Theaflavin of tea infusions prepared from CTC-tea were more than that of O-tea of the same region. Thearubigins was recorded more in all CTC-tea samples over O-tea except for the sample manufactured at Nilgiri. Caffeine content was high in CTC-tea samples of Nilgiri, Terai and Shillong whereas for Assam and Dooars it was high in O-tea. Free radical scavenging activity was more in CTC-tea than O-tea of the same region. O-tea showed better antibacterial activity than CTC-tea.

Background Salep is obtained by grinding dried orchid tubers and used as a valuable ingredient in the food industry. Because of the glucomannan content of salep, it is thought to have prebiotic potential. However, there is little information in studies concerning the fermentation characteristics and potential prebiotic properties of salep. The objective of this study was to investigate the effect of salep on bifidobacterial growth by measuring the highest optical density (OD), calculating the specific growth rates, and determining the production of lactic acid and short-chain fatty acids (acetic, propionic, and butyric acid) as a result of bacterial fermentation. Result The OD and pH values obtained in this study showed that salep was utilized as a source of assimilable carbon and energy by the Bifidobacterium species (BS). All Bifidobacterium strains produced lactic, acetic, propionic, and butyric acid, indicating that salep is readily fermented by these bacteria. Salep at 1% (w/v) showed a similar effect on bifidobacterial growth as that promoted by 1% (w/v) glucose used as a traditional carbon source. Conclusions Bifidobacterium species can develop in media containing salep as well as in glucose and exhibit the potential to be used as new sources of prebiotics. How to cite: Usta-Gorgun B, Yilmaz-Ersan L. Short-chain fatty acid production by the Bifidobacterium species in the presence of salep. Electron J Biotechnol 2020;47. https://doi.org/10.1016/j.ejbt.2020.06.004 .

Indoor and outdoor air of five (5) hospitals in Ilorin, Kwara state were sampled using settling plate method to isolate fifteen (15) bacteria. Bacillus cereus was the identified spore former. Biodegradation performance of Bacillus cereus on hexadecane and heptane using Mineral Salts Medium (MSM) was studied for 20 days at four days interval using the Jenway 6320D Spectrophotometer to assess the optical density. The degradation and utilization of the hydrocarbons occurred before the fourth day with readings for optical density obtained as 1.051nm and 0.820nm for hexadecane and heptane respectively. After day 4, there was a sharp decline in the utilization of hydrocarbons. A second experiment was setup for optical density with heptane and decane utilization being checked daily for a period of 5days. Bacillus cereus utilized the hydrocarbons till the fourth day as the optical density dropped on the fifth day. The readings for decane obtained on day 4 and day 5 were 0.431nm and 0.338nm respectively. Also, there was a decline in the readings of heptane from 0.451nm obtained on day 4 to 0.343nm obtained on day 5. This study shows that Bacillus cereus is promising in the biodegradation of alkanes and can also be utilized to clean up pollution from petroleum spill which is becoming a prevalent ecological hazard. Keywords: Air, Bacillus cereus, Biodegradation, Hospitals, Hydrocarbons

—IR spectroscopy is used to assess the ease and depth of oxidation of roadmaking bitumen on the basis of the relative integral optical density of the carbonyl group’s absorption band during RTFOT and PAV tests. For different samples, the ease of short-term oxidation (the short-term oxidizability) of bitumen differs by an order of magnitude, while the difference in the long-term oxidizability is no more than 1.5-fold. The oxidation depth of different bitumen samples differs fivefold, with about 1.3-fold variation in aromatic content. The overall influence of increased oxidizability and oxidation depth of bitumen is established, in terms of increase in viscosity and softening temperature (ring and ball method) and decrease in penetration and extensibility.

Background and Aim: Candida albicans is a dimorphic fungus that has both yeast and filamentous forms. It is part of the normal flora in the oral and genital areas of mammals. One factor for the pathogenicity of C. albicans is its ability to switch from yeast to hyphae. The hyphal form adheres and penetrates tissues more readily than the yeast form and produces biofilms that are associated with chronic infection. Biofilms are protective niches that enable microorganisms to be more resistant to antibiotic treatment, thus allowing for persistent infection. The first stage in the transition from yeast to hyphae involves the formation of a germ tube, and this transition is triggered by interactions with host cells. Germ tube formation is dependent on serum, pH, temperature, and quorum-sensing molecules (QSMs). Farnesol, which is a QSM in C. albicans, can prevent yeast to hyphae conversion and inhibits the growth of fungal biofilm. Lyticase is a synergistic enzyme complex that catalyzes yeast cell lysis by β-1,3-glucanase and is a highly specific alkaline protease that produces protoplasts or spheroplasts. This study investigated the effect of farnesol and lyticase on the formation of C. albicans biofilms. Materials and Methods: C. albicans ATCC 2091 was cultivated on liquid and solid Sabouraud media. The presence of C. albicans was confirmed using HiCrome Candida Agar chromogenic medium. Enzyme activities were assayed using a HiCandida Identification Kit. The morphology and densitometry parameters of C. albicans biofilms were considered in the presence of farnesol (Sigma-Aldrich, Germany), lyticase (from Arthrobacter luteus; Sigma-Aldrich, Germany), and farnesol–lyticase. Results: This study shows that both farnesol and lyticase possess antifungal activity against C. albicans biofilms. A significant difference among treatment groups (p

Bicarbonate is an alternative carbon source for production of photosynthetic microalgae, although sparging of CO2-enriched gas is commonly practised, its efficiency seems to be scarcely considered. This study evaluated the photosynthetic activities of microalgae (Tetradesmus wisconsinensis) using chlorophyll fluorescence under different concentrations of bicarbonate (HCO3-) and CO2. Chlorophyll fluorescence analysis showed noticeable difference in photosynthetic activity between the bicarbonate (HCO3-) and CO2 supplied cultures. The JIP-test parameters obtained for the cultures supplemented by HCO3- or CO2 were distinct, but of similar values in quantum yield of PSII. The typical polyphasic rise, called the OJIP curves, showed a typical difference between the treatments at the J and I inflection of the fluorescence transient curve. Both HCO3- (20 mM) and CO2 (5%, v/v) gave higher biomass yield than the other carbon regimes, i.e., 673 ± 12 and 658 ± 11 mg L-1, respectively. We concluded that bicarbonate resulted in similar photosynthetic yield as CO2 supplementation.

The use of nanocelluloses is being conducted for the most diverse applications. Their performance as coating agent has been mainly explored to improve barrier properties, as they emerge as perfect candidate for plastic substitution, but it is also important to explore their potential to improve printing quality. In the present work, the influence of different nanocelluloses, obtained through mechanical, enzymatic, TEMPO-mediated oxidation and carboxymethylation treatments, in the coating process and inkjet printability of office papers was assessed. The results revealed that the cellulose nanofibrils are better for printability than the microfibrils. But the size and charge of the former must be taken into account, since fibrils of very small size penetrate the paper structure, dragging the pigments from the surface, and very anionic nanofibrils can also have negative influence on the optical density. Besides, an interesting synergy between surface-sizing starch and the cellulose nanofibrils was found to occur as the latter closed the paper structure, which prevented starch from penetrating, while potentiating both of their positive effects on ink pigment entrapment. An additional study of characterization of inkjet pigments was also performed.

Introduction. An innovative antifungal agent based on hydrochloride with combination of PEG-400 and PEG-1000 has been developed based at the chairs of Sechenov University. This solution is designated for external application as an antifungal agent. Naftifine hydrochloride has a broad spectrum of action against various fungi capable of causing onychomycosis. PEGs, forming part of the developed dosage form, bring about necessary viscosity of the solution (for retention in application area) and do not prevent drug product performance. Naftifine hydrochloride has an apparent UV absorption band with maximum of 256 ± 2 mn, in connection with this, it is supposed to use the UV spectrophotometry method for further development of quantitation method of naftifine hydrochloride detection in tested oral liquid.Aim. To evaluate the feasibility of using the UV spectrophotometry method for development of quantitation of naftifine hydrochloride in its solution with a combination of PEG for mycotic infection treatment.Materials and methods. The substance of naftifine hydrochloride, PEG-400 and PEG-1000, ethyl alcohol 96 %, UV spectrophotometry, «Millipore» filter.Results and discussion. A set of operations was carried out with UV spectrophotometer, including trials of solutions of initial substance of naftifine hydrochloride, PEG solutions, a solution of developed prolonged antimycotic drug and its placebo. The identity of UV spectra of the actual substance in various media was determined, maximum absorption of actual substance and dependence preservation between specified concentration and optical density of the solution were proved. It was found that auxiliary substances included in liquid dosage form do not affect the main characteristics of the UV spectrum of actual substance.Conclusion. The possibility in principle of using the UV spectrophotometry method for quantitative and qualitative analysis of innovative prolonged antimycotic drug – liquid dosage form of naftifine hydrochloride with a combination of PEG has been established.

Aim : to evaluate the diagnostic value and objectification of the STARS questionnaire in the evaluation of risk of age-related macular degeneration (AMD) development. Patients and methods . 104 patients (206 eyes) 40 males (32.3 %), 84 women (67.7 %), who filled the self-administered STARS screening questionnaire, were enrolled in the study. All patients were referred without suspicion or established diagnosis of AMD of any other retinal pathology. Optical coherent tomography (OCT) and macular pigment optical density (MPOD) were carried out in order to objectify questionnaire score points and retinal structural changes. Results. The significant difference was found between patient without AMD and those with newly established AMD diagnosis not only in questionnaire score but also in some structural changes indicators: mean retinal thickness, foveal retinal thickness by OCT (

The existing methods for monitoring the performance of multi-criteria fire detectors do not provide for verification of their characteristics in the conditions of transition from smoldering to flame burning. The aim of the work is the development of the research methods of the environmental parameters during the transition from smoldering (pyrolysis) to flame combustion for simulation a test fire while checking the quality of multi-criteria fire detectors.A technique to conduct research of environmental parameters under conditions of heating wood samples of different sizes to a temperature of selfignition and burning crumpled and smooth paper has been developed.Changes in the concentration of carbon monoxide, specific optical density, and scattering ability during the transition from smoldering (pyrolysis) to flame burning of prepared wood and crumpled paper were studied for the first time.It is shown that the controlled environmental parameters during the transition from smoldering pyrolysis to flame burning change together. Conclusion: the speed of growth of the scattering ability of smoke decreases by 2.4 times, the speed of increase in the specific optical density and concentration of carbon monoxide increases by 2 and 5.3 times (respec-tively), during the transition from pyrolysis to flame burning of wood.

Background Recently it was shown that production of recombinant proteins in E. coli BL21(DE3) using pET based expression vectors leads to metabolic stress comparable to a carbon overfeeding response. Opposite to original expectations generation of energy as well as catabolic provision of precursor metabolites were excluded as limiting factors for growth and protein production. On the contrary, accumulation of ATP and precursor metabolites revealed their ample formation but insufficient withdrawal as a result of protein production mediated constraints in anabolic pathways. Thus, not limitation but excess of energy and precursor metabolites were identified as being connected to the protein production associated metabolic burden. Results Here we show that the protein production associated accumulation of energy and catabolic precursor metabolites is not unique to E. coli BL21(DE3) but also occurs in E. coli K12. Most notably, it was demonstrated that the IPTG-induced production of hFGF-2 using a tac-promoter based expression vector in the E. coli K12 strain TG1 was leading to persistent accumulation of key regulatory molecules such as ATP, fructose-1,6-bisphosphate and pyruvate. Conclusions Excessive energy generation, respectively, accumulation of ATP during recombinant protein production is not unique to the BL21(DE3)/T7 promoter based expression system but also observed in the E. coli K12 strain TG1 using another promoter/vector combination. These findings confirm that energy is not a limiting factor for recombinant protein production. Moreover, the data also show that an accelerated glycolytic pathway flux aggravates the protein production associated “metabolic burden”. Under conditions of compromised anabolic capacities cells are not able to reorganize their metabolic enzyme repertoire as required for reduced carbon processing.

The multilayer perceptron (MLP) topology of an artificial neural network (ANN) was applied to create two predictor models in Agrobacterium-mediated gene transformation of tobacco. Agrobacterium-mediated transformation parameters, including Agrobacterium strain, Agrobacterium cell density, acetosyringone concentration, and inoculation duration, were assigned as inputs for ANN–MLP, and their effects on the percentage of putative and PCR-verified transgenic plants were investigated. The best ANN models for predicting the percentage of putative and PCR-verified transgenic plants were selected based on basic network quality statistics. Ex-post error calculations of the relative approximation error (RAE), the mean absolute error (MAE), the root mean square error (RMS), and the mean absolute percentage error (MAPE) demonstrated the prediction quality of the developed models when compared to stepwise multiple regression. Moreover, significant correlations between the ANN-predicted and the actual values of the percentage of putative transgenes (R2 = 0.956) and the percentage of PCR-verified transgenic plants (R2 = 0.671) indicate the superiority of the established ANN models over the classical stepwise multiple regression in predicting the percentage of putative (R2 = 0.313) and PCR-verified (R2= 0.213) transgenic plants. The best combination of the multiple inputs analyzed in this investigation, to achieve maximum actual and predicted transgenic plants, was at OD600 = 0.8 for the LB4404 strain of Agrobacterium × 300 μmol/L acetosyringone × 20 min immersion time. According to the sensitivity analysis of ANN models, the Agrobacterium strain was the most important influential parameter in Agrobacterium-mediated transformation of tobacco. The prediction efficiency of the developed model was confirmed by the data series of Agrobacterium-mediated transformation of an important medicinal plant with low transformation efficiency. The results of this study are pivotal to model and predict the transformation of other important Agrobacterium-recalcitrant plant genotypes and to increase the transformation efficiency by identifying critical parameters. This approach can substantially reduce the time and cost required to optimize multi-factorial Agrobacterium-mediated transformation strategies.

Biofilm formation is triggered by unfavourable external conditions that modify the expression of several genes. Biofilm, in turn, alters the microenvironment of its inhabitants that leads to alteration of gene expression and maturation of biofilm. Stenotrophomonas maltophilia is an aerobic, glucose non-fermentative, Gram-negative bacterium wide spread in the environment. The present study reports the isolation, identification, genotypic and phenotypic characterization, of the Stenotrophomonas strains isolated from the industrial effluent sample and the ability of Stenotrophomonas maltophiliaSRS05-GRD (KF558319) for biofilm formation is evaluated using different substrates and different medium. Based on the graphical representation of optical density values obtained by incorporating various substrates in Tryptone Soya Broth (TSB), glass was found to support high biofilm formation of Stenotrophomonas maltophilia SRS05-GRD. The results obtained indicate that the commercial media (TSB with glucose and soybean meal at pH 7) shows optimum biofilm formation. This study has, therefore, confirmed the potential of Stenotrophomonas maltophilia SRS05-GRD to form biofilm. Optimum medium and dilution of the culture was also determined that yield effective biofilm formation.

The article considers the change in chemical and biological characteristics in some legumes grains, under conditions of high-temperature micronization with different moisture contents during heat treatment with infrared rays. The heat treatment of grains was carried out on a laboratory apparatus with a quartz radiant infrared panel. The temperature variation in the heat treatment zone occurred due to changing the distance between the panel and the surface of grains. The grain temperature was determined using a laser thermometer, and with a timer. To determine chemical and biological characteristics, we used a special optical density metering device. We have studied: 1. The dependence of starch content on the temperature in the changing initial moisture content. We found that after 30 seconds of high-temperature micronization of, “Tsanava“ beans at a grain moisture content of 12.7%, the starch content in the grain increases from 39.65% to 40.12%, then gradually decreases, and at 18.3% moisture content, it increases from 38.71% to 41.2%, with a moisture content of 28.6% it increases from 37.36% to 42.42%. Similar processes are also observed for the beans “field red“ and “white lupine“; 2. The dependence of glucose content on the temperature in the changing initial moisture content. As the mass fraction of starch decreases, the percentage of sugar (in terms of the equivalent amount of glucose) at a moisture content of 12.7% at the initial stage increases from 1.36% to 1.46%, and then the percentage of sugar increases relatively quickly to 1.64%, at a moisture content of 18.3% it increases from 1.3% to 1.38%, and then increases to 1.51, with a moisture content of 28.6%, it increases from 1.28% to 1.35% and then increases to 1.54. Similar processes are also observed for the beans “field red“ and “white lupine“.

Aim. To study the resistance of lactobacilli strains to some aggressive factors of gastrointestinal tract in vitro depending on the primary isolation source. Methods. 13 lactobacilli strains isolated from self-fermenting vegetables, meat raw materials, children excrements were used in this work. The stability of bacteria to metabolites of the digestive system was determined by their cultivation in the MRS medium with bile, sodium chloride and phenol. Results. The vast majority of lactobacilli was tolerant at 2.5–5.0% NaCl. The increasing NaCl concentration to 7.5% has resulted in decrease of the viable cells number and its growth intensity. It was shown that the strains isolated from self-fermenting vegetables were the most resistant to NaCl. The presence of 20 and 40 % bile in the cultural medium slowed but did not inhibit the lactobacilli growth. The most resistant to bile were the strains isolated from raw meat. All lactobacilli strains grew in the presence of phenol in cultivation medium at concentrations of 0.2–0.6%, but it was shown that with increasing of phenol concentration, the optical density was significantly reduced. Conclusion. Investigated lactobacilli strains showed a variable reaction to the action of sodium chloride, salts of bile and phenol, which was determined by the specific strain and the concentration of the active substance. It has been shown that there is the partial relationship between resistance to the investigated factors and the source of lactobacilli isolation.

We evaluate the robustness of optical density (OD) as a tool in the assessment of the biomass of the cryptophyte Rhodomonas salina under different growth conditions. We measure the OD under three different wavelengths, 550, 665 and 750 nm. We find, as expected, that growth rates of the microalga depend strongly on growth conditions, being highest in saturating light conditions under non‐limiting nitrogen (N) availability. OD – cell count relationships are strong and well defined regardless of the growth conditions and wavelength used for measurement. However, measuring within the absorption range of chlorophyll, at 550 and 665 nm, does give higher regression coefficients under conditions leading to a high cell chlorophyll content, while the coefficients of determinations are slightly higher when cell chlorophyll content is low. We conclude that to use OD as a proxy for biomass under large‐scale production of microalgae, it is important to take into account that the precise relationship between OD and algal biomass does depend on factors such as irradiance and nutrient availability, and hence the physiological state of the microalgae as well as the production conditions. Errors in estimation of biomass may range from 44% to 95%, if these factors are not taken into consideration.

The aim of this research was to study the bifidogenic effect of salep powder on some Bifidobacterium species, namely B. lactis, B. infantis, B. longum and B. bifidum. The growth of the Bifidobacterium species was investigated by measuring the pH and optical density (OD) during 48 h-fermentation. In order to evaluate the efficiency of the fermentation of salep powder by the Bifidobacterium subsp. lactic, acetic, butyric and propionic acid values in the growth media were quantified by HPLC. It was determined that Bifidobacterium species might be used salep powder as a source of carbon and the highest OD values were found for B. lactis in media containing glucose and for B. infantis in media containing salep powder. All the tested strains observed the ability to produce higher amounts of lactic and acetic acids than amounts of propionic and butyric acids. Consequently, it was determined that all four Bifidobacterium species were able to ferment salep powder. Moreover, because salep powder enhanced the growth and activity of Bifidobacteria and it might be conferred as a bifidogenic effect.

Temperature effect on the kinetics of plasticization of cellulose nitrate/plasticizer compositions is studied. The obtained experimental data are used to construct a mathematical model of the dissolution of cellulose nitrate in plasticizer. The mathematical model describes the dependence of the optical density of 1 % cellulose nitrate/plasticizer compositions on time, temperature, and type of the plasticizer, as well as the rate of change of the optical density as a function of temperature and type of the plasticizer.

In this research, we purposed to study some biochemical characteristics and effects of fertilizers on the accumulation of inulin polysaccharides in the tubers of Helianthus tuberosus L. For this purpose, three types fertilizers of organic, organic-mineral complex and mineral mixed pellets were used, and the inulin polysaccharide content was determined optical density using spectrophotometer in 285 nm light range. The content of the inulin polysaccharide was the highest in control sample to 31.0% and the lowest in mineral mixed pellets fertilizer to 9.9%. From this point of view, mineral mixtures fertilizer negatively affect the accumulation of inulin is polysaccharide. Protein analysis results shows that two variants with mineral-containing fertilizers give more protein content to control samples, particularly, leaf proteins are 5.08% and 4.21% and the tuber protein is 2.79% and 2.37%. It is proved that mineral fertilizers have a positive effect on protein synthesis. Булцуут цэцгийн (helianthus tuberosus l) биохимийн зарим үзүүлэлтэд бордооны нөлөө Хураангуй: Бид энэ удаа Булцуут цэцгийн биохимийн зарим үзүүлэлт болон булцуун дахь инулины полисахаридын хуримтлалд бордооны үзүүлэх нөлөөг судлах зорилго тавилаа. Үүний тулд 3 төрлийн буюу органик, органик-эрдэс нийлмэл, эрдэсхолимог үрлэн бордоонуудаар булцуут цэцгийг бордож ургуулан инулины полисахаридын агууламжийг 285 нм гэрлийн мужид оптик нягтыг нь спектрофотометр ашиглан тодорхойлсон. Инулины полисахаридын агууламж нь хяналтын хувилбар дээр хамгийн өндөр буюу 31.0%, харин эрдэс бордоо хэрэглэсэн хувилбар дээр хамгийн бага буюу 9.9% байв. Эндээс дүгнэхэд эрдэс холимог үрлэн бордоо нь инулины полисахаридын хуримтлалд сөргөөр нөлөөлж байгааг харуулж байна. Харин булцуу болон навчиндуургийн агууламж тодорхойлсон дүнгээс харахад хяналттай харьцуулахад органик-эрдэс нийлмэл бордоогоор бордсон хувилбарт навчны уураг 5.08%, булцууны уураг нь 2.79%, эрдэс холимог үрлэн бордоотойд 4.21%, 2.37%-иар тус тус илүү байна. Энэ нь эрдэс бордоо уургийн нийлэгжилтэнд эерэг нөлөөтэй болохыг харуулж байна. Түлхүүр үг: Инулин, уураг, эслэг, шим тэжээлийн элемент

The amylosecontents in starch is one of its qualitycharacteristics. Generally it is a specific sign of astarch-containing material and the starch received from it. Physical and chemical properties of starch and its use in the national economy depend on it. In small quantities the amylose is received by starch fractionating. It is the difficult and expensive technology. Selectors carry out research workson creation of new varieties of potatoes, grain and leguminous crops with the increased content of amylose in starch. They need techniques of definition of amylose in different types of raw materials. But before developing a technique, it is necessary to investigate optical properties of this or that type of starch and the components making it. It showed from researches, different types of starchhad differentoptical properties of itscomponents. For example, the technique developed for definition of amylose in corn starch isn't acceptable for its definition in starch of triticale and wheat. Earlier we studied properties of iodine polysaccharides of corn and triticale starches and factors affecting the optical properties of iodine polysaccharides. In this work it was investigated the influence of amylose, concentration of iodine and potassium iodide at KI:I from 3 to 15 on an optical density of wheat iodine polysaccharidessolutions. It is established that the iodine amylose of wheat has a maximum at 600 nanometers, an iodine amylopectin has at 565 nanometers. Spectra of wheatpolysaccharides differ in value of an optical density ?max and a form of curves from related polysaccharides of triticale. Concentration of an iodine in the studied solution has to be equal 0.6 mg/cm3, and a ratio of potassium iodide to an iodine has to be 5.

Background and Objective: Infusion containing lorazepam is used by geriatric department to limit anxiety disorders in the elderly. Currently, these infusions are prepared according to demand by the nursing staff, but the preparation in advance in a centralized service could improve quality of preparation and time management. The aim of this study was to investigate the long-term stability of this infusion in polypropylene syringes stored at 5 ± 3°C. Then, results obtained were compared with stability data of lorazepam in syringes stored at room temperature, glass bottles at 5 ± 3°C, and glass bottles at room temperature. Method: Eight syringes and 6 bottles of infusion were prepared by diluting 1 mL lorazepam 4 mg in 23 mL of NaCl 0.9% under aseptic conditions. Five syringes and 3 bottles were stored at 5 ± 3°C and 3 syringes and 3 bottles were stored at room temperature for 30 days. During the storage period, particle appearance or color change were periodically checked by visual and microscope inspection. Turbidity was assessed by measurements of optical density (OD) at 3 wavelengths (350 nm, 410 nm, 550 nm). The stability of pH was also evaluated. The lorazepam concentrations were measured at each time point by high-performance liquid chromatography with ultraviolet detector at 220 nm. Results: Solutions were physically unstable in syringes at 5 ± 3°C after 4 days: crystals and a drop of OD at 350 nm were observed. However, pH was stable. After 2 days, solutions were considered as chemically unstable because a loss of lorazepam concentration higher than 10% was noticed: the lower 1-sided confidence limit at 95% was below 90% of the initial concentration. To assess temperature and polypropylene influence, results were compared with those obtained for syringes at room temperature and bottles at 5 ± 3°C and room temperature. Precipitation, drop of OD at 350 nm, and chemical instability were observed in all conditions. Conclusion: Solutions of lorazepam were unstable after 2 days in syringes at 5 ± 3°C. Preparation in advance appears, therefore, not possible for the clinical use. Storage conditions (temperature and form) do not improve the stability.

Effect of various nitrate replete concentrations have been investigated in terms of biomass yield, cell and nitrate concentrations. Media used in this study is Bold’s basal medium which contains nitrate that act as nutrient. Its concentrations have been varied for obtaining the high biomass yield. The nitrate concentrations used were 30 mg nitrate/L, 35 mg nitrate/L, 40 mg nitrate/L, 45 mg nitrate/L and 50 mg nitrate/L) with 30 mg nitrate/L as a control. Microalgae Chlorella sp. is cultured and aerated in a Schott bottle with presents of light. Results showed that the best concentration to obtain highest biomass yield was 45 mg nitrate/L. It also gave the highest optical density reading at day 9 with 2.100 ± 0.070 and showed the highest cell concentration with 703 ± 29 x 106 cells/mL. Dry algae produced by this concentration after the end of the cycle was 291 ± 9 mg which was the highest compared to other concentration. It is suggested that as the biomass yield is increased by using 45 mg nitrate/L concentration, other methods to increase lipid content can be paired with nitrate replete method and can be further studied in the future.

We experimentally demonstrate and elucidate by numerical simulations that breaking circular symmetry of large apertures of vertical-cavity surface-emitting lasers (VCSELs) significantly enhances their emission properties by increasing the optical density of states. Specifically, deformed shapes of circular oxide apertures of VCSELs enhance stimulated emission and suppress undesired non-radiative recombination contributing to an increase in output optical output power of more than 60% and in quantum efficiency of more than 10%. Our example deformed VCSEL structures demonstrate that the optical density of states appears to be of high importance for conventional optoelectronic devices in accordance to the predictions of quantum electrodynamics theory.

Echinops kebericho Mesfin is traditionally used for the treatment of various infectious diseases. This study investigated antibacterial activity of the essential oil (EO) and the different fractions of ethanol extract. The most active component was isolated and identified. Isolation and purification was accomplished using chromatographic techniques while identification was done by spectroscopic method. Minimum inhibitory concentration (MIC) was determined using the broth micro-dilution method. In bioactive-guided isolation, percent inhibition was determined using optical density (OD) measurement. The MICs of the essential oil ranged from 78.125 μg/ml to 625 μg/ml, and its activity was observed against methicillin-resistant Staphylococcus aureus (MRSA, NCTC 12493). Ethyl acetate fraction showed high activity against MRSA (NCTC 12493), MIC = 39.075 μg/ml followed by Enterococcus faecalis (ATCC 49532), MIC = 78.125 μg/ml and was least active against Klebsiella pneumoniae (ATCC 700603), MIC = 1,250 μg/ml. MIC of hexane fraction ranged from 156.2 µg/ml to Escherichia coli (ATCC 49532) to 1,250 μg/ml to E. coli (NCTC 11954). The MICs of chloroform fraction ranged from 312.5 to 2500 μg/ml; while butanol fraction could be considered pharmacologically inactive as its MIC value was 2,500 μg/ml for all and no activity against E. coli (NCTC 11954). Dehydrocostus lactone was successfully isolated and identified whose MIC was 19.53 μg/ml against MRSA. Dehydrocostus lactone isolated from E. kebericho M. showed noteworthy antibacterial activity which lends support to ethnopharmacological use of the plant. Further optimization should be done to improve its antibacterial activities and pharmacokinetic profile.

The present study investigate the optical density of Streptococcus Mutans (S. mutans) at 450 nm (OD450 nm) as well as the change in surface roughness of three commercially available chitosan- and nanodiamond-modified glass ionomers. The results indicated that the optical density of S. mutans OD450 nm decreased significantly (p < 0.0001) from 0 hours through 2 hours to 4 hours for each of the control materials. The lowest S. mutans OD450 nm was noted for Fuji IX followed by Ketac Universal. Riva Self Cure had the largest increase in the S. mutans OD450 nm. The control materials and their chitosan / nanodiamond modifications showed significant growth at 6 hours compare to the preceding time periods of 2 and 4 hours. The materials Fuji IX, Fuji IX modified with 5% Nanodiamonds, Fuji IX modified with 10% Chitosan and Ketac Universal modified with 10% Chitosan performed the best with regard to the bacterial reduction. Only the chitosan modifications showed an increase in the surface roughness after 24 hours of exposure to the S. mutans. The chitosan and the nanodiamond modifications provided the best disruption of the S. mutans biofilm formation.

Background: Airway hyperresponsiveness is related to the intensification of the lipid peroxidation (LP) in asthma. We aimed to study the effect of smoking on the LP status of asthma patients with EIB. Methods: 62 subjects (36.2±1.3 years) with EIB (drop of FEV1 -21.9±2.0%) were divided into 2 groups: the 1st included 30 non-smokers, the 2nd - 32 smokers (8.2±1.5 pack/year). The contents of conjugated dienes and non-oxidized lipids in the exhaled breath condensate were analyzed before and after 6-minute submaximal exercise on treadmill, using ultraviolet spectra of lipid extracts absorption and evaluated in terms of optical density at 233 nm (E233) and 206 nm (E206), respectively. Results: In group 2, FEV1 was lower (84.6±2.7 vs. 92.0±2.5%; p 0.05) in the2nd group led to a change in E233/E206 after exercise: 0.39±0.09 (p>0.05) vs. 0.38±0.05 (p Conclusion: Smoking in asthmatics with EIB leads to changes in the LP, which is accompanied by a deterioration of airway patency and a decrease of the response to dosed exercise.

This work is aimed at creating a modified invasive technique for assessing the liver&rsquo, s functional reserves. A study of the degree of hepatodepression is carried out by measuring the plasma elimination of indocyanine green using the method of optical densitometry. This paper presents test results for an aqueous solution and an albumin solution, as well as the results of measurements of plasma elimination of indocyanine green for patients with liver disease. Perfecting the proposed method will make an important scientific contribution to modern diagnostic medicine. Diagnosing the stages in the progression of the disease and its developing complications can make it possible to rapidly correct the patient&rsquo, s treatment algorithm, achieving positive outcomes in medical practice.

A low-cost bifunctional immunochromatographic colorimetric biosensor was developed that can be read visually or by using an optical density scanner. Five test lines (T lines) coated with different antigens were set on a nitrocellulose (NC) membrane to indicate the concentration of analyte. This method was applied for the detection of dexamethasone. The corresponding detection range was 0.1–9 ng mL−1, and the detection limit for dexamethasone in food supplements and cosmetic samples was 2.0 μg kg−1. For visual inspection of the colour the quantitative relative error range between the proposed method and liquid chromatography was −62 to −25%, with a detection time of only 10 min. More accurate assay results were obtained by using an optical density scanner with the relative error range of −31 to 20%. The results indicated that the proposed method has the potential of application for rapid and efficient screening of dexamethasone in cosmetics and food supplements.

Objective: The aim of this study is to compare macular pigment optical density levels across four different ethnicities and study its influence on ganglion cell layer and retinal nerve fibre layer thickness across these ethnicities. Methods: Consenting adults visiting the ophthalmology and optometry clinics for a routine eye examination without any ocular comorbidity were enrolled. Participants underwent optical coherence tomography for macular thickness, retinal nerve fibre layer thickness and ganglion cell layer thickness. The macular pigment optical density levels were determined in the dominant eye using the QuantifEye device by trained observers. Results: In total, 336 eyes of 336 participants with a mean age of 39.2 ± 14.4 years were included of which 103 (30%) were Caucasians, 111 (33%) were African Americans, 29 (9%) were South Asian Indians and 94 (28%) were Hispanics. The mean macular pigment optical density value across the entire study population was 0.47 ± 0.15. South Asian Indians (0.58 ± 0.16) and Hispanics (0.52 ± 0.15) had significantly higher mean macular pigment optical density values compared with Caucasians (0.41 ± 0.16) and African Americans (0.38 ± 0.15). Linear regression analysis showed that there was a significant association between ethnicities and macular pigment optical density values when adjusted for age (β coefficient = 0.31, 95% confidence interval = 0.029–0.58, p Conclusion: Caucasians and African Americans have lower macular pigment optical density compared with South Asian Indians and Hispanics. There is no clinically significant association between macular pigment optical density levels and retinal nerve fibre layer and ganglion cell layer thickness in healthy individuals across races.

To explore predisease biomarkers, which may help screen for the risk of age-related macular degeneration (AMD) at very early stages, macular pigment optical density (MPOD) and photoreceptor outer segment (PROS) length were analyzed. Thirty late AMD fellow eyes, which are at high risk and represent the predisease condition of AMD, were evaluated and compared with 30 age-matched control eyes without retinal diseases, there was no early AMD involvement in the AMD fellow eyes. MPOD was measured using MPS2&reg, (M.E. Technica Co. Ltd., Tokyo, Japan), and PROS length was measured based on optical coherence tomography images. MPOD levels and PROS length in the AMD fellow eyes were significantly lower and shorter, respectively, than in control eyes. MPOD and PROS length were positively correlated in control eyes (R = 0.386, p = 0.035) but not in AMD fellow eyes. Twenty (67%) AMD fellow eyes met the criteria of MPOD &lt, 0.65 and/or PROS length &lt, 35 &mu, m, while only five (17%) control eyes did. After adjusting for age and sex, AMD fellow eyes more frequently satisfied the definition (p &lt, 0.001, 95% confidence interval, 3.50&ndash, 60.4, odds ratio, 14.6). The combination of MPOD and PROS length may be a useful biomarker for screening predisease AMD patients, although further studies are required in this regard.

Spectrophotometric monitoring of 4-nitrophenol (4-NP) reduction by sodium borohydride (NaBH4) using gold nanoparticles (GNPs) as a catalyst has been extensively studied, but the stability of GNPs in terms of change in the surface plasmon resonance (SPR) at different temperatures has not been explored. In the present investigation, our aim was to evaluate the SPR stability of GNPs as a catalyst during the reduction of 4-NP at different elevated temperatures (i.e. 30-60 degrees C) and sodium borohydride concentrations. Sensitivity of this degradation process toward concentration of GNPs at a range of temperatures is also evaluated. The spectrophotometric results reveal that up to 45 degrees C, 12 +/- 1.5 nm catalyst has a consistent optical density (OD) during the entire 4-NP reduction process, which is related to the surface integrity of catalyst atoms. As the temperature approached 50 degrees C, the OD gradually decreased and showed a blue shift as the reaction proceeded, which could be related to a decrease in particle size or surface dissolution of gold atoms. The present study may find application in the design of catalysts for the reduction of organic pollutants in industrial wastewater at a range of temperatures.

A method for rapid and accurate determination of avian pathogenic Escherichia coli serotype O78 (APEC O78) by the gold nanoparticle-labeled lateral flow strip method, entitled molecule capturer analysis system (MCAS), is described. Target virulence-associated gene of APEC O78 is adopted as the analyte. After pre-amplification with the designed functional primer set, numerous new-formed amplicons are simultaneously labeled with fluorescein isothiocyanate (FITC) and digoxin. AuNPs with a diameter of 18 nm and the characteristic plasmonic peak at 526 nm are utilized for labeling. These two labels of FITC and digoxin are further captured and measured with the AuNP-labeled lateral flow strip, and the AuNPs are retained on the test line through the immunoreaction for signal output. Under optimized conditions, this MCAS protocol can determine the target APEC O78 with excellent determination limit of 4.3 cfu mL−1 based on the optical density of AuNPs on the test line of lateral flow strips. The working range is 2.52 × 101 to 1.63 × 107 cfu mL−1. Spiked serum samples are rapid and accurately measured, and the results are highly correlated with those of the real-time PCR. With this MCAS protocol, rapid and on-site determination of APEC O78 can be realized without expensive instruments or professional personnel. This MCAS protocol can be easily applied to other analytes by just replacing the traditional primer set with functionalization primer set.

Macular pigment (MP), comprising the dietary carotenoids lutein, zeaxanthin and meso-zeaxanthin, is believed to benefit eye health and vision. Numerous clinical and research devices and techniques are currently available to facilitate MP optical density (MPOD) measurement. One of those techniques, dual-wavelength fundus autofluorescence (AF) is being increasingly used for measurement of MP in the eye. There is substantial methodological variation across the published studies that have employed this technique, including in relation to the use of mydriasis, the possible influence of which does not appear to have been addressed in the literature. This prospective cross-sectional study was designed to investigate the effect of mydriasis on MP measurement quality and MPOD values obtained with dual-wavelength AF using the Heidelberg Spectralis HRA+OCT device.Twenty-one healthy participants were recruited to the study. The mean age of participants was 44.8 years (± 14.63). Pupil size and MPOD were measured in one eye for each participant, initially under natural pupil conditions and subsequently 30 minutes following instillation of one drop of 0.5% tropicamide.Despite providing MPOD measurements for the majority of undilated eyes (85.7% of eyes herein), pupillary dilation resulted in statistically significant changes in MPOD (This study clearly demonstrates that dual-wavelength AF measurements of MPOD in the same eye vary as a function of pupillary dilation status, with MPOD under-estimated across the entire spatial profile of MP for natural relative to dilated pupillary conditions. Mydriasis should, therefore, be used routinely for MPOD measurements using dual wavelength AF, pupil size should be reported and image quality optimized in order to ensure accurate MPOD quantification.

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals, In an inter-laboratory study, the authors compare the accuracy and performance of three optical density calibration protocols (colloidal silica, serial dilution of silica microspheres, and colony-forming unit (CFU) assay). They demonstrate that serial dilution of silica microspheres is the best of these tested protocols, allowing precise and robust calibration that is easily assessed for quality control and can also evaluate the effective linear range of an instrument.

BACKGROUND: Four parallel continuous stirred tank reactors were used to investigate the single and joint exposure of Zn and Cu to Arthrobacter sp. JM018, in terms of the impact on the adenosine triphosphate (ATP) pool and microbial tolerance. RESULTS: ATP, optical density (OD), and substrate concentration measurements indicated that Cu was more toxic than Zn under all conditions studied. The results showed that although both OD and ATP measurements individually reflected a decrease in microbial growth rate after the addition of metals for the reactors exposed to Cu, specific ATP (i.e. ATP/OD) showed only a temporary reduction followed by a monotonic return to pre‐exposure levels within 100 h. The latter implied tolerance and recovery in the energy status of these cells, after the initial shock due to the exposure to Cu. CONCLUSION: Specific ATP is an important quantity to be considered as a measure of the activity or energy status of microbial biomass surviving after exposure to toxic metals or other unfavorable conditions. The study provides insights for maintaining metal‐tolerant microbial communities and to explore both quantitatively and experimentally the dynamics of ATP pool and microbial tolerance in metal‐contaminated environments. © 2018 Society of Chemical Industry

PURPOSE To evaluate the radiopacity of luting cements submitted to different aging procedures. MATERIALS AND METHODS Twenty discs (1 × 4 mm) of each of the following cements were prepared: zinc phosphate, RelyX Luting 2, Variolink 2, AllCem, RelyX U200, Multilink, Panavia F2.0, and RelyX ARC. Then, they were randomly divided into two groups (n = 10/group), according to the aging procedure: thermal cycling group and water storage group. Before and after aging procedures, specimens were x-rayed with an aluminum step-wedge (11 steps, 1 mm thick each) and three dental slices (1 mm thick). The radiopacity was evaluated by means of optical density, which was measured using ImageJ software. The values were converted into millimeters of aluminum with a logistic regression calibration curve. The data were analyzed by one-way ANOVA and Tukey post-hoc test (α = 0.05). RESULTS In the thermal cycling group, RelyX Luting 2, RelyX U200, and Panavia F2.0 showed a statistically significant reduction in radiopacity (p < 0.05). In the water storage group, all cements showed a significant reduction in radiopacity (p < 0.05), and RelyX Luting 2 and Panavia F2.0 performed below the desired ISO 4049 standard. CONCLUSIONS The radiopacity of luting cements can decrease after aging, especially after 1-year water storage.

In this work, the conditions of spectrophotometric evaluation of the ninhydrin assay for L-lysine in a water dimethyl sulfoxide solution were investigated. The absorption spectrum of the L-lysine–ninhydrin reaction product exhibited two maxima at 420 and 500 nm. It was shown that pH of the reaction medium affected the intensity of the product color. The stability of the ninhydrin reaction products was the highest at pH 8–9. The phase proportion of the water–organic solution had little effect on the optical density of the product. The absorption spectra of the ninhydrin reaction products of L-lysine derivatives: Nα-boc-lysine and Ne-z-lysine, indicated that it was the α amino group of lysine that participated in the reaction.

Methane (CH4) emissions are a major environmental concern in composting facilities. Therefore, this study initially visualized the dynamic distribution and quantity of methanogens and methanotrophs in composting particles during manure aerobic composting using fluorescence in situ hybridization–confocal laser scanning microscopy (FISH–CLSM) and quantified their correlation with CH4 emissions. The visualization results showed that methanogens existed inside the particles, while methanotrophs clustered in the outer layer; a facultative anaerobic zone existed in between. The quantification results of integral optical density of methanogens and methanotrophs per unit particle area (Ugen and Uoxi, respectively) indicated that, in the cooling phase, CH4 generation and oxidation could still be high and could strike a balance if the initial organic matter content of composting materials is high, while both could be extremely low if the content is low. A strong linearity between Ugen obtained by FISH–CLSM and methyl-coenzyme M reductase copy number obtained by quantitative polymerase chain reaction analysis (R2 = 0.88) was observed, which justified the effectiveness of the FISH–CLSM method and demonstrated that macro-scale CH4 emissions were essentially an accumulation of particle-scale CH4 emissions. CH4 emissions were equal to 3.3297 × 107 Ugen – 3.1814 × 106 Uoxi – 3902.9900 (R2 = 0.98). Overall, the results showed that methanogens exerted more influence on CH4 emissions than methanotrophs. Combining these results with CH4-generation and -oxidation kinetics may help illustrate CH4-emission mechanisms, improve particle-scale CH4-emission models, and thereby provide theoretical guidance for operation optimization and emission reduction in composting processes.