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A method of mathematically processing the digital images of targets is developed. The theoretical and mathematical justification and the experimental validation of the possibility of estimating the amount of gunshot residue (GSR) and determining the GSR distribution over the target on the basis of its digital image is provided. The analysis of the optical density in selected concentric rings in the images reveals the radial dependence of soot distribution in the cross section of a gas–gunpowder jet. The analysis of the optical density in selected sectors of the circle reveals the angular dependence of the soot distribution in the gas–gunpowder jet cross section. It is shown that the integral optical density averaged over a selected area in the target image characterizes the mass of GSP deposited on it. It is possible to quantify the differences in the radial and angular distributions of the thickness of the GSR layer on various targets obtained both with the help of weapons of different types at the same distances and with the help of weapons of the same type at different distances, by calculating the distribution of optical density on their digital images.

Optical density (OD) measurement is the standard method used in microbiology for estimating bacterial concentrations in cultures. However, most studies do not compare these measurements with viable cell counts and assume that they reflect the real cell concentration. Burkholderia thailandensis was recently identified as a polyhydroxyalkanoate (PHA) producer. PHA biosynthesis seems to be coded by an orthologue of the Cupriavidus necator phaC gene. When growing cultures of wild-type strain E264 and an isogenic phaC mutant, we noted a difference in their OD600values, although viable cell counts indicated similar growth. Investigating the cellular morphologies of both strains, we found that under our conditions the wild-type strain was full of PHA granules, deforming the cells, while the mutant contained no granules. These factors apparently affected the light scattering, making the OD600values no longer representative of cell density. We show a direct correlation between OD600values and the accumulation of PHA. We conclude that OD measurement is unreliable for growth evaluation of B. thailandensis because of PHA production. This study also suggests that B. thailandensis could represent an excellent candidate for PHA bioproduction. Correlation between OD measurements and viable cell counts should be verified in any study performed with B. thailandensis.

Antibiotic resistance is a global threat to modern society. Rapid determination of suitable antibiotics that inhibit bacterial growth can effectively reduce antibiotic resistance and improve clinical treatment. The conventional methods of antimicrobial susceptibility testing (AST) depend on optical density measurements, which require long-time incubation. Various kinds of rapid AST systems which utilize various technologies from the field of lab on a chip have promised a great reduction in measurement time, but cannot achieve high-throughput, user-friendly testing due to the complexity of the testing system. Here, we introduce a capillary and centrifuge-based rapid AST system that reduces the time of loading the sample and culture media while achieving a high-throughput testing capacity. The capability of the proposed system is validated in a systematic analysis that includes sample loading characteristics and AST trials with standard strains. The proposed system provides a useful tool for drug testing in cell-culture systems with user-friendly and high-throughput analysis.

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.

In recent years, many studies have found that mechanical tension can activiate NF-kB signal pathway and NF-kB plays an important role in the process of osteogenesis. However, it is still unclear whether this process exists in the anterior palatal suture expansion. In this paper, we mainly studied the effect of intraperitoneal injection of PDTC on the NF-kB signaling pathway and osteogenesis index of the anterior palatal suture expansion model in young adult rats. The expansion model is grouped and established: 45 male 8-week-old Sprague-Dawley rats were randomly divided into three groups, an expansion only (EO) group, an expansion plus PDTC (PE) group, and a control group. The results revealed that PDTC inhibited the activity of NF-kB signaling pathway and promote one morphogenetic protein 2 (BMP-2), steocalatin (OCN) expression. Compared with the control group, the optical density (OD) value of BMP in the EO group and PE group rats increased significantly from the first day to the seventh day, and the difference was statistically significant (P

In this paper, we tried to create a contractile model from proteins of the catch muscle of the Gray mussel, similar to the well-described suspension contractile model of vertebrate skeletal muscles. This model makes it possible to characterize the processes in the reconstructed contractile apparatus with the help of monitoring the two characteristics of muscle suspensions - the optical density and the particle size. Contractile model of the catch muscle we constructed was the simplest model consisting of two proteins, actin and myosin. During this work we compared the optical manifestations of the contraction and relaxation states of constructed model with earlier data on the actomyosin suspension of skeletal muscles. It appeared that the approach used in the study of skeletal muscle actomyosin relaxing – the use of an increased amount of ATP − cannot be applied to the contractile model of the molluscan catch muscle. Nevertheless we managed to reach relaxed state of this model with modifying calcium concentration. As a result, we laid the foundation for further reconstruction of the third state of the catch muscle – the catch tone.

A redox potential-driven fermentation, maintaining dissolved oxygen at a prescribed level while simultaneously monitoring the changes of fermentation redox potential, was developed to guide the cultivation progress of recombinant protein expression. A recombinant E. coli harboring prolinase-expressing plasmid (pKK-PepR2) was cultivated using the developed process. Two distinct ORP valleys were noticeable based on recorded profile. The first ORP valley is equivalent to the timing for the addition of inducing agent, and the second ORP valley serves to guide the timing for cell harvesting. The final prolinase activity is 0.172 μmol/mg/min as compared to that of 0.154 μmol/mg/min where the optical density was employed to guide the timing of inducer addition and an empirically determined length of the cultivation. The developed process can be further modified to become an automatic operation.

As compared with 2D cell line cultures, 3D intestinal organoids are better at maximally recapitulating the physiological features of stem cells in vivo. However, the complex 3D structure is an obstacle which must be objectively and automatically evaluated to assess colony growth and regeneration. Meanwhile, no internal standard currently exists for evaluating the size of heterogeneities in organoids or defining those regenerating colonies. Herein, we developed a simple morphometry system to image MTT-stained organoids. The growth curve of organoids can be automatically generated based upon analyzing the integrated optical density using software. Referencing the definition standards of in vivo regenerating crypts, the perimeters of crypts cultured 24 h after seeding were selected as an “Organoid Unit” to further evaluate colony survival rate and colony size heterogeneities after exposure to varying doses of irradiation. Moreover, the morphometry-based quantification data collected confirmed other findings associated with radiation sensitizing effects of ataxia telangiectasia mutated (ATM) and ataxia telangiectasia and Rad3-related protein (ATR) inhibitor and the radiation protective effect of IL-22. In summary, the novel organoid morphometry system combined with a new internal reference is a practical means for standardizing assessment of growth, survival and regeneration of intestinal organoid colonies. This method has promise to facilitate drug screens in intestinal and other organoid systems.

Most amphibians produce their own defensive chemicals; however, poison frogs sequester their alkaloid-based defenses from dietary arthropods. Alkaloids function as a defense against predators, and certain types appear to inhibit microbial growth. Alkaloid defenses vary considerably among populations of poison frogs, reflecting geographic differences in availability of dietary arthropods. Consequently, environmentally driven differences in frog defenses may have significant implications regarding their protection against pathogens. While natural alkaloid mixtures in dendrobatid poison frogs have recently been shown to inhibit growth of non-pathogenic microbes, no studies have examined the effectiveness of alkaloids against microbes that infect these frogs. Herein, we examined how alkaloid defenses in the dendrobatid poison frog, Oophaga pumilio, affect growth of the known anuran pathogens Aeromonas hydrophila and Klebsiella pneumoniae. Frogs were collected from five locations throughout Costa Rica that are known to vary in their alkaloid profiles. Alkaloids were isolated from individual skins, and extracts were assayed against both pathogens. Microbe subcultures were inoculated with extracted alkaloids to create dose-response curves. Subsequent spectrophotometry and cell counting assays were used to assess growth inhibition. GC-MS was used to characterize and quantify alkaloids in frog extracts, and our results suggest that variation in alkaloid defenses lead to differences in inhibition of these pathogens. The present study provides the first evidence that alkaloid variation in a dendrobatid poison frog is associated with differences in inhibition of anuran pathogens, and offers further support that alkaloid defenses in poison frogs confer protection against both pathogens and predators.

International audience; Diclofenac (DCF) adverse reactions involve diverse mechanisms in different models. We recently demonstrated that DCF-induced toxicity in HepaRG decreases as they express DCF-metabolizing enzymes. DCF metabolism promotes toxicity in Saccharomyces cerevisiae expressing heterologous cytochromes-P450. N-Acetylcysteine (NAC) is used to treat diverse medical conditions due to its multiple properties (antioxidant, metal chelator, thiol-disulfide disruption). The latter property accounts for its mucolytic effects and broadens its potential molecular targets to signal transduction proteins, ABC transporters and others. Interaction of NAC with DCF effects depends on the experimental model. This study aims to investigate NAC/DCF interaction and the involvement of ABC transporters in wild type and mutant Saccharomyces cerevisiae. DCF inhibited yeast growth in a dose- and time-dependent manner and the cells started adapting to DCF 24-h post-treatment. NAC potentiated DCF-induced toxicity if added prior or parallel to DCF. Pretreatment with NAC increased its potentiation effect and compromised cells adaption to DCF. Post-treatment with NAC potentiated DCF toxicity without compromising adaptation. Moreover, mutant strains in ABC transporters Pdr5, Yor1, Bpt1 or Pdr15, were more sensitive to DCF; while mutant strains in Pdr5, Vmr1 or Pdr12 were more sensitive to NAC/DCF interaction. DCF ± NAC elicited on the mutant strain in Yap1, an oxidative stress-related protein, the same effects as on the wild type. Therefore, oxidative stress does not seem to be key actor in DCF toxicity in our model. Our hypothesis is that NAC potentiation effect is at least due to its ability to disrupt disulfide bridge in proteins required to overcome DCF toxicity in yeast.

The performance of recently developed polydimethylsiloxane (PDMS)-based optical system was tested for measuring optical density of microbial culture. The data showed that PDMS-based spectrometer is superior to “one drop” spectrometers in the accuracy, and has an advantage over conventional spectrometers in measuring dense culture without dilution.

In the manufacture of biodiesel, glycerol is a byproduct. Acetone-butanol-ethanol (ABE) fermentation by anaerobe Clostridium acetobutylicum ia also a source of biofuel. Growth of C. acetobutylicum in the presence of waste biodiesel glycerol byproduct was examined in this investigation. In cultures containing added glucose or a mixture of glucose and byproduct the optical density (OD) was increased and a positive fermentation reaction was exhibited while results in cultures containing byproduct or pure glycerol were similar to those in the base medium. The pH of cultures containing glucose markedly decreased. The concentration of glucose dropped to an undetectable level. All cultures were determined to contain alcohol. The potential applications for biodiesel glycerol byproduct need to e explored.

Цель настоящей работы разработка доступного теста для скрининга функциональной активности системы комплемента по классическому пути. Материалы и методы. В работе исследовали сыворотки крови 90 относительно здоровых лиц с избыточной массой тела (ИМТ 25) без метаболического синдрома. Иммуноферментный анализ функциональной активности системы комплемента по классическому пути проводили с использованием коммерческого набора. Реакцию лизиса эритроцитов барана, сенсибилизированных антителами (ЕА), оценивали турбидиметрически по снижению оптической плотности суспензии при длине волны 620 нм, степень лизиса определяли по калибровочному графику. Результаты. Разработан простой скринингтест для определения функциональной активности классического пути системы комплемента. Корреляционный анализ показал высокую степень сходимости результатов (r 0,496), полученных разными методами. Заключение. Скринингтест для определения функциональной активности классического пути системы комплемента является быстрым, информативным и доступным для рутинных исследований., The aim of this work was to develop an accessible test for screening the functional activity of the complement system classic pathway. Materials and methods. Blood serum from 90 relatively healthy, overweight (BMI25) individuals without the metabolic syndrome was studied. Enzyme immunoassay of the complement system functional activity following the classic pathway was performed using a commercial kit. The lysis of antibodysensitized sheep erythrocytes was evaluated turbidimetrically by a decrease in suspension optical density at a wavelength of 620 nm the lysis intensity was determined by the calibration curve. Results. A simple screening test was developed to determine the functional activity of the complement classic pathway. A high degree of correlation (r 0.496) was observed between results obtained by different methods. This screening test for evaluating the functional activity of classic complement system pathway is fast, informative, and available for routine research., №4 (2019)

Growth in minimal salts medium meant that a microorganism has the full repertoire of biosynthetic machinery for surviving in habitats lacking in vitamins and growth factors. This significantly expands the types of habitats suitable for colonization by the microbe. Such evolutionary selected and endowed survival advantage provided a critical growth advantage and colonization potential to particular microbes. Pseudomonas protegens Pf-5 (ATCC BAA-477) potential for growth in minimal salts medium was evaluated by aerobic growth experiments at 25 and 30 oC in M9 medium. Experiment results revealed that the bacterium could grow in M9 medium without nutrient and yeast extract supplementation, but with a long lag phase of 18 hours and a small optical density of 0.7 and 1.0 at 25 and 30 oC, respectively after 45 hours of incubation. Variation in pH, on the other hand, revealed similar pH profiles of net secretion of acidic metabolites during growth in M9 medium, that stabilized prior to attainment of maximal optical density in the cultures at the two temperatures. Supplementation of M9 medium with 1 g/L yeast extract at 25 oC resulted in a shorter lag phase of 3 hours in P. protegens Pf-5 and a maximal optical density of 3.1, which indicated the importance of vitamins and growth factors in yeast extract in supplying necessary building blocks for biomass formation. Similarly, net secretion of acidic metabolites was observed in pH profile prior to exponential phase growth in P. protegens Pf-5, which was followed by a gradual rise in culture broth’s pH. Collectively, P. protegens Pf-5 could grow in minimal salts medium without supplementation of vitamins and growth factors at 25 and 30 oC; thereby, pointing to a significant competitive advantage in survival and colonization of new habitats in the face of nutritional and environmental stressors.

A multi-wavelength based optical density sensor unit was designed, developed, and evaluated to monitor microalgae growth in real time. The system consisted of five main components including: (1) laser diode modules as light sources, (2) photodiodes as detectors, (3) driver circuit, (4) flow cell, and (5) sensor housing temperature controller. The sensor unit was designed to be integrated into any microalgae culture system for both real time and non-real time optical density measurements and algae growth monitoring applications. It was shown that the sensor unit was capable of monitoring the dynamics and physiological changes of the microalgae culture in real-time. Algae biomass concentration was accurately estimated with optical density measurements at 650, 685 and 780 nm wavelengths used by the sensor unit. The sensor unit was able to monitor cell concentration as high as 1.05 g·L−1 (1.51 × 108 cells·mL−1) during the culture growth without any sample preparation for the measurements. Since high cell concentrations do not need to be diluted using the sensor unit, the system has the potential to be used in industrial microalgae cultivation systems for real time monitoring and control applications that can lead to improved resource use efficiency.

Using gold nanoparticles (AuNPs) on “capillary enzyme-linked immunosorbent assay (ELISA)”, we produced highly sensitive and rapid assays, which are the major attributes for point-of-care applications. First, in order to understand the size effect of AuNPs, AuNPs of varying diameters (5 nm, 10 nm, 15 nm, 20 nm, 30 nm, and 50 nm) conjugated with Horseradish Peroxidase (HRP)-labeled anti-C reactive protein (antiCRP) (AuNP•antiCRP-HRP) were used for well-plate ELISA. AuNP of 10 nm produced the largest optical density, enabling detection of 0.1 ng/mL of CRP with only 30 s of incubation, in contrast to 10 ng/mL for the ELISA run in the absence of AuNP. Then, AuNP of 10 nm conjugated with antiCRP-HRP (AuNP•antiCRP-HRP) was used for “capillary ELISA” to detect as low as 0.1 ng/mL of CRP. Also, kinetic study on both 96-well plates and in a capillary tube using antiCRP-HRP or AuNP•antiCRP-HRP showed a synergistic effect between AuNP and the capillary system, in which the fastest assay was observed from the “AuNP capillary ELISA”, with its maximum absorbance reaching 2.5 min, while the slowest was the typical well-plate ELISA with its maximum absorbance reaching in 13.5 min.

Beer’s law describes the diminution in intensity as light passes through an absorbing medium. Photometry, the primary application of the law in chemistry, is used to deduce the concentration of a light-absorbing component from the decrease in the intensity of monochromatic radiation during passage through a known length of the medium. This article describes the history and nomenclature of the law, as well as its mathematical basis. It goes on to show how the law becomes modified if the absorbing species not only absorbs the light but is also slowly destroyed by it. An intriguing feature is that the same function—the so-called “bleaching function”—describes not only the way in which the light intensity declines with distance, but also the dependence of concentration on time.

Effect of the steroidal saponins of Fructus tribuli on growth of Lactobacillus acidophilus LA04, LA05 and LA06 was studied by measuring optical density at 600 nm (OD 600) and pH using MRS media as the control. The addition of steroidal saponins (w/v) was 0.05, 0.10, 0.15, 0.20 and 0.25%, respectively. Results were as follows: addition of steroidal saponins of Fructus tribuli could promote the growth of Lactobacillus acidophilus LA04, LA05 and LA06 and the optimum concentration of steroidal saponins was all 0.25% for the three strains.

Effect of polysaccharides and water extract from Fructus tribuli on growth of Lactobacillus brevis was studied by measuring the optical density at 600 nm and pH using commercial MRS broth as the control. The addition (mg/mL) of steroidal saponins was 0.10, 0.20, 0.30, 0.40 and 0.50 and the addition (%, v/v) of water extract was 1, 2, 3, 4 and 5. Results were as follows: The additions of polysaccharides and water extract had a significant promotion on the growth of Lactobacillus brevis. The optimum concentrations of steroidal saponins and water extract were 0.40 mg/mL and 5%, respectively.

The ratio of H 2 /acetate in glucose fermentation shall be equal or less than 2. However, the ratio over 2 is found in the literature. Two possible reasons were proposed in this study: acetate oxidation or biomass growth via acetyl-CoA. In order to find out the right reason, glucose fermentation by Caldicellulosiruptor saccharolyticus was investigated. Under different glucose concentrations (1.0 g/L, 2.0 g/L, 3.5 g/L and 7.5 g/L), the Optical Density (OD) reached a maximum value of 0.35, 0.48, 0.53 and 0.55, respectively. It was found that the ratios of H 2 /acetate under different glucose concentrations were all greater than 2. When CH 3 - 13 COOH was added to the system, 60% of CH 3 - 13 COOH was converted to isotope ethanol. About the same amount of 13 CO 2 (0.01 mmol) was detected in both the control and isotopic experiments, illustrating acetate oxidation didn't occur in this study. The corrected ratio of H 2 /acetate after the compensation from biomass growth was around 2, demonstrating the biomass growth from acetyl-CoA was the right reason for the abnormal high ratio.

The acetylation/deacetylation of Lys40 of the α-subunit is an important posttranslational modification undergone by tubulin during the life of a cell. Many previous studies have addressed the physiological role of this acetylation process using various approaches based on changes of acetylated tubulin (AcTubulin) content. In most of these studies, however, the actual amounts of AcTubulin were not known and it was difficult to draw conclusions. We present here a simple method to estimate the percentage of AcTubulin relative to total tubulin. The method is based on acetylation of the tubulin sample with acetic anhydride, Western blotting stained by antiAcTubulin antibody, and comparison of the optical density of the AcTubulin band with that of a corresponding sample that was not chemically acetylated. © 2013 Wiley Periodicals, Inc.

Antibodies against the chemokine platelet factor 4 (PF4) in complex with heparin cause the prothrombotic adverse drug reaction heparin-induced thrombocytopenia (HIT). The current dilemma for laboratory diagnosis of HIT is that only about 50% of these antibodies are pathogenic, but the widely available enzyme immunosorbent assays (EIA), used for diagnosis in the clinical laboratory cannot differentiate between non-pathogenic- and pathogenic (platelet activating) antibodies. It would be highly desirable to improve diagnosis for HIT. Here, we use single-molecule force spectroscopy to identify conditions at which non-pathogenic antibodies show a different reactivity pattern compared to pathogenic antibodies. At physiological conditions (pH 7.4, 150 mM NaCl), non-pathogenic antibodies bound to PF4/heparin complexes with weaker binding forces than pathogenic ones. Binding forces measured over a wide range of pH or ionic strength show that non-pathogenic antibodies are not significantly affected by environmental changes, whereas pathogenic antibodies are. Based on the dissimilar behavior of these antibodies at 500 mM salt, we performed a PF4/heparin EIA at this condition and observed that optical density of non-pathogenic antibodies slightly reduced while it drastically reduced for pathogenic antibodies. Our results suggest that the specificity of anti-PF4/heparin EIAs for clinically relevant antibodies can be improved by changing test conditions.

Radiographic photodensitometry has been used to track changes in bone mineral content in the distal limb of horses through traditional film radiographs. With increasing popularity of digital radiographs, the technique has been adapted for digital technology. The objective of this study was to validate and describe the analysis of digital radiographs and to compare traditional densitometric analysis to digital analysis. Twelve traditional and 12 digital radiographs were taken of the left third metacarpal (MCIII) of 12 horses with an aluminium stepwedge penetrometer attached to the radiographic cassette. Both medial-lateral and dorsal-palmar views were represented. The traditional and digital radiographs were each analysed using two different methods to compare results. Analysis involved determining optical density at each step of the aluminium stepwedge, plotting optical density verses mm Al, and then determining the equation of the subsequent line. The optical density of each cortice was inserted into the equation and radiographic bone aluminium equivalents (RBAE) in mm Al for each cortice was determined. Total RBAE was also examined 1 cm distal to the nutrient foramen of the MCIII. Data were analysed using Proc CORR (SAS v. 9.1) and are reported as mean ± standard deviation. Total RBAE on the dorsal-palmar view from traditional radiographs averaged 286±154 mm Al for digital analysis and 292±173 mm Al for densitometric analysis (R2=0.98). Total RBAE on medial-lateral view from the digital radiographs averaged 539±137 mm Al for digital analysis and 530±165 mm Al for densitometric analysis (R2=0.95). The results demonstrate high correlations between analyses, thereby validating that digital analysis yields similar results as densitometric analysis. Digital radiographs, with increased clarity as compared to traditional films, should allow greater ability to detect treatment differences in research trials, and monitor changes associated with training or nutrition.

Drip loss is an important meat quality trait of fresh meat affecting economic losses. The cytochrome P450c21 (CYP21) protein has a role on cortisol production and depends on stress. This might affect meat quality. The present study aimed to investigate the expression of CYP21 protein in correlation with drip loss. The samples were taken from the Longissimus dorsi muscle to evaluate drip loss (n = 300). Five muscles per group (low and high drip loss) were selected to evaluate CYP21 protein expression levels. Statistical analysis revealed that CYP21 protein expression levels were significantly difference between the drip loss groups. The high drip loss group had higher CYP21 protein expression levels than the low drip loss group (P

This study aimed to deparaffinize formalin-fixed paraffin-embedded (FFPE) tissues using hot water instead of xylene and measuring the quantity and quality of the extracted DNA from the respective tissues. To deparaffinize the tissue sections with hot water, small sections were exposed to 90 °C distilled sterile water. After 25 FFPE tissue samples were deparaffinized with the hot water method, DNA was then extracted. The mean of optical density and the ratio of absorbance of the DNA solution were 220.01 ± 36.1 ng/μl and 1.65 ± 0.1, respectively. Polymerase chain reaction (PCR) analysis of the toll-like receptor 4(TLR4) gene showed that the method can be used as a tool for different applications.

This study presents the biodecolorization potential of basidiomycete fungi Trametes hirsuta, Pycnoporus sp., and Irpex sp. for different reactive dyes viz. Reactive Red 120, Remazol Brilliant Blue R (RBBR), Reactive Orange G, and Reactive Orange 16 under static and shaking conditions. The screening trials revealed that T. hirsuta exhibited maximum potential (83.75 %) for biodecolorization of RBBR dye under static conditions after the fifth day of incubation. However, the rate of biodecolorization of RBBR dye by Pycnoporus sp. was much slow and reached maximum (81.25 %) after 15 days of incubation under shaking conditions. By process optimization, enhanced decolorization (91.2 %) of RBBR by T. hirsuta was achieved at pH 5.5 within 24 h using a defined salt medium amended with p-coumaric acid under static conditions. pH was found to be an important parameter for the enzymatic system involved in RBBR dye decolorization by T. hirsuta and Pycnoporus sp. Biodecolorization of RBBR dye was determined by a reduction in optical density at the wavelength of maximum absorbance (λ, 578 nm) by UV-vis spectrophotometer. The shift in maximum wavelength toward shorter/longer wavelength in UV-vis scanning spectrum revealed the degradation of RBBR dye into different transformation products.

Effect of steroidal saponins and flavonoid from Fructus tribuli on growth of Lactobacillus brevis was studied by measuring the optical density at 600nm and pH using De Man, Rogosa and Sharpe (MRS) broth as the control. The addition (mg/ml) of steroidal saponins was 0.10, 0.20, 0.30, 0.40 and 0.50, and the addition (mg/ml) of flavonoid was 0.10, 0.15, 0.20, 0.25 and 0.30. Results were as follows: The additions of steroidal saponins and flavonoid had a significant promotion on the growth of Lactobacillus brevis. The optimum concentrations of steroidal saponins and flavonoid were 0.20mg/ml and 0.15mg/ml respectively.

We demonstrated direct assimilation of cellooligosaccharide using Escherichia coli displaying beta-glucosidase (BGL). BGL from Thermobifida fusca YX (Tfu0937) was displayed on the E. coli cell surface using a novel anchor protein named Blc. This strain was grown successfully on 0.2% cellobiose, and the optical density at 600 nm (OD 600 ) was 1.05 after 20 h.

Effect of steroidal saponins fromFructus tribuli on growth of Bifidobacterium bifidum BB01, BB03 and Lactobacillus acidophilus LA09 was studied by measuring optical density at 600nm (OD600) and pH using MRS media as the control. The concentration of steroidal saponins (w/v) added in was 0.05%, 0.10%, 0.15%, 0.20% and 0.25%. Results were as follows: addition of steroidal saponins could improve the buffer ability of MRS and promote the growth of Bifidobacterium bifidum BB01 and BB03. The optimum concentration of nutrient supplement in MRS media was 0.20% at incubation 24h for Bifidobacterium bifidum BB01 and 0.25% at incubation 24h for Bifidobacterium bifidum BB03. Addition of steroidal saponins on Lactobacillus acidophilus LA09 didn’t play an obvious role in promoting growth when it was in high level.

Effect of the extract of Fructus tribuli (EFT) on growth of Lactobacillus acidophilus LA04, LA05, LA06 and LA09 was studied by measuring optical density at 600nm (OD600) and pH using MRS culture media as the control. The addition of EFT (v/v) was 1%, 2%, 3%, 4% and 5%. Results were as follows: addition of EFT could promote the growth of Lactobacillus acidophilus LA09, The optimum concentration of EFT in MRS media was 1% at incubation 24h, but addition of EFT on growth of Lactobacillus acidophilus LA04, LA05 and LA06 has no significant effect.

The present study is focused on the experimental verification of the efficiency of Arbutus unedo L. leaves against the crystallization of calcium oxalate. The inhibition of crystallization has been studied in vitro with the absence and the presence of the different concentrations of the infusion and hydroalcoholic extract of the plant. This study consists of measuring, using a UV-Visible spectrophotometer, the temporal evolution of the optical density at λ = 620 nm corresponding to the crystals formation. The latter have been characterized by microscopic observation using an optical microscope, and by Fourier Transform Infrared Spectroscopy (FT-IR). The results suggest a greater effectiveness of the plant infusion with respect to the hydroalcoholic extract against crystallization or nucleation at percentages of 69.41 ± 0.24 or 19.76 ± 0.27% and at 93.92 ± 2.61 and 45.16 ± 3.06% against the aggregation, for both the infusion and the hydroalcoholic extract respectively. A. unedo leaves is a very promising and effective remedy against the crystallization of calcium oxalate and especially in the aggregation stage.

SUMMARY The aerial parts of methanol extract of Oxystelma esculentum (MEOE) (Asclepiadaceae) was evaluated forin vitro lipid peroxidation and antimicrobial activity. Lipid peroxidation was assayed by thechange in optical density of the various concentrations (20 - 320 µg/ml) and the percentageinhibition was estimated. Ascorbate/FeSO4-induced peroxidation was inhibited by MEOE andstandard antioxidants such as BHA, BHT and the percentage inhibition of the methanol extractwas increased with dose dependent manner. The IC 50 value of the MEOE, BHA and BHT for lipidperoxidation was found to be 135.24 µg/ml, 25.62 µg/ml and 17.13 µg/ml, respectively. Theantimicrobial activity of MEOE was determined by disc diffusion method with three gram-positive, five gram-negative and two fungal microorganisms. MEOE exhibited the antimicrobialactivity against the tested microorganisms except Salmonella typhimurium (MTCC 98). In presentstudy, it is concluded that MEOE has significant effect in the inhibition of lipid peroxidation andpossesses good antimicrobial activity.Key words: Oxystelma esculentum; Lipid peroxidation; Antimicrobial activity

The effects of manganese on the activities of GS, PAG, SDH and Na+-K+-ATPase were investigated and the impact of MK-801, Tau and DM on manganese-induced neurotoxicity were observed in rats. Seventy Wistar rats were divided into seven groups, 10 animals for each group. The first group was the control group, the second to fourth groups were 8, 40 and 200 μmol/kg MnCl2 groups, the fifth to seventh groups were 0.3 μmol/kg MK-801, 1 μmol/kg Tau and 13.5 μmol/kg DM pretreatment groups. The animals were injected with manganese chloride for 25 days and pretreated for every other day. Manganese resulted in the reduction of GS, SDH and Na+-K+-ATPase activities, and the increase of PAG activity. The percentage of positive area and integral optical density of glutamate immunocreative cell were significantly increased in the group given 200 μmol/kg MnCl2 alone. Pretreatment with MK-801, Tau and DM can antagonize neurotoxicity induced by manganese in the certain extent.

A multianalyte lateral-flow immunochromatographic technique using colloidal gold-labeled polyclonal antibodies was developed for the rapid simultaneous detection of clenbuterol and ractopamine. The assay procedure could be accomplished within 5 min, and the results of this qualitative one-step assay were evaluated visually according to whether test lines appeared or not. When applied to the swine urines, the detection limit and the half maximal inhibitory concentration (IC(50)) of the test strip under an optical density scanner were calculated to be 0.1 +/- 0.01 ng mL(-1) and 0.1 +/- 0.01 ng mL(-1), 0.56 +/- 0.08 ng mL(-1), and 0.71 +/- 0.06 ng mL(-1), respectively, the cut-off levels with the naked eye of 1 ng mL(-1) and 1 ng mL(-1) for clenbuterol and ractopamine were observed. Parallel analysis of swine urine samples with clenbuterol and ractopamine showed comparable results obtained from the multianalyte lateral-flow test strip and GC-MS. Therefore, the described multianalyte lateral-flow test strip can be used as a reliable, rapid, and cost-effective on-site screening technique for the simultaneous determination of clenbuterol and ractopamine residues in swine urine.

The ability of bacteria to reduce nitroblue tetrazolium (NBT) to formazan, and the inhibition of this process by antibiotics, have been utilized in a method to determine antibiotic concentrations in serum. Escherichia coli, growing in the presence of increasing but subinhibitory concentrations of antibiotics, produces diminished amounts of formazan. This is photometrically quantified and the optical density obtained with the sample is compared with those obtained with know concentrations. Levels of aminoglycosides below 1 microgram/ml can be measured in the presence of other antibiotics also, and the assay can be carried out in three hours. Good correlation was obtained when 49 serum samples containing varying concentrations of sisomicin were tested simultaneously by the NBT assay and a disc diffusion method.

A simple spectrophotometric method of standardization of platelet suspensions is described which demonstrates an initial gradual change in optical density for 4 days followed by a stable light transmittance for up to 2 years. Hence standardization is possible at any suspension age. Several series of microcomplement-fixation tests are presented which characterize the slow deterioration of antigenic strength of these suspensions, with good reactions still obtained on suspensions almost 2 years old when strong antisera are investigated.

We report the synthesis and the photochromic behavior of a newly designed, photochromic, radical diffusion-inhibited hexaarylbiimidazole (HABI) derivative with markedly improved photochromic performance in coloration and decoloration rates as well as greater optical density in the colored state. The thermal bleaching rate (tau1/2 = 260 ms at 295 K) is the fastest among the reported ones for HABI derivatives.

BACKGROUND Lutein and docosahexaenoic acid (DHA) may protect against age-related macular degeneration (AMD). Lutein is a component of macular pigment. DHA is in the retina. OBJECTIVE The objective of this 4-mo study was to determine the effects of lutein (12 mg/d) and DHA (800 mg/d) on their serum concentrations and macular pigment optical density (MPOD). DESIGN Forty-nine women (60-80 y) were randomly assigned to placebo, DHA, lutein, or lutein + DHA supplement. Serum was analyzed for lutein and DHA (0, 2, and 4 mo). MPOD was determined (0 and 4 mo) at 0.4, 1.5, 3, and 5 degrees temporal retinal eccentricities. Serum was analyzed for lipoproteins (4 mo). RESULTS There was no interaction between lutein and DHA supplementations for serum lutein and MPOD. The lutein supplementation x DHA supplementation x month interaction was significant for serum DHA response (P < 0.05). In the lutein group, serum lutein increased from baseline at 2 and 4 mo (P < 0.001), and MPOD increased at 3.0 degrees (P < 0.01). In the DHA group, serum DHA increased at 2 and 4 mo (P < 0.0001), and MPOD increased at 0.4 degrees (P < 0.05). In the lutein + DHA group, serum lutein and DHA increased at 2 and 4 mo (P < 0.01), and MPOD increased at 0.4, 1.5, and 3 degrees (P = 0.06, 0.08, and 0.09, respectively). Differences from placebo in lipoprotein subfractions were greatest for the lutein + DHA group (4 mo). CONCLUSIONS Lutein supplementation increased MPOD eccentrically. DHA resulted in central increases. These results may be due to changes in lipoproteins. Lutein and DHA may aid in prevention of age-related macular degeneration.

Summary A number of bacterial, organoleptic and chemical evaluations were made on iced queen scallops in shell over 14 days total. The spoilage flora, qualitative and quantitative, is described. Organoleptic descriptions are given along with determinations of trimethylamine, total volatile bases, volatile reducing substances, glycogen, hypoxanthine, ribose fractions and optical density ratios at 248 nm before and after treatment with ion-exchange resin. Hypoxanthine showed the most promise as a spoilage indicator while total volatile bases and optical density ratio showed some promise but to a lesser extent.

Purpose To investigate macular pigment optical density (MPOD) and serum concentration changes of lutein in Japanese subjects participating in a clinical trial in which two formulations of lutein and zeaxanthin supplements with different physiochemical properties are used. Methods Thirty-six healthy volunteers were recruited into this prospective, randomized, parallel-group, double-masked comparative study at a single institute. Two products were used, FloraGLO® (Kemin Japan) and XanMax® (Katra Phytochem). The lutein particle size and zeaxanthin concentrations differed between the formulations. The subjects consumed one of the two supplements for a duration of up to 6 months. MPOD levels were measured by resonance Raman spectrometry at baseline and once a month until the end of the study. Serum lutein concentration was measured at baseline, month 3, and month 6. The subjects were also tested for contrast sensitivity, glare sensitivity, visual acuity, and in addition had a focal electroretinogram measured. Results The mean serum lutein concentrations increased significantly after the first three months, but the mean MPOD levels in either supplement group did not show any statistically significant increase. A detailed analysis, however, revealed three response patterns in both groups for the increase of MPOD levels and serum lutein concentration, i.e. “retinal responders”, who had an increase of both MPOD levels and serum lutein concentrations (n = 13), “retinal non-responders”, who had only increased serum concentrations and no change in MPOD levels (n = 20), and “retinal and serum non-responders”, who had neither MPOD level nor plasma concentration increases (n = 3). The subjects with low MPOD levels at baseline appeared to show increased MPOD levels at the 6 month time point upon lutein supplementation (r = -0.4090, p = 0.0133). Glare sensitivity improved in retinal responders in both supplement groups, while there were no remarkable changes in contrast sensitivity. Conclusions No statistically significant differences could be detected for MPOD levels and serum lutein concentrations between the two investigated lutein supplement formulations. Responses to lutein supplementation regarding MPOD levels and serum lutein concentrations varied between subjects. Subjects with lower MPOD levels at baseline responded well to lutein supplementation. However, since the number of subjects was low, a further study with more subjects is needed to prove that subjects with low MPOD levels will benefit from lutein supplementation. Trial Registration UMIN-CTR UMIN000004593

It is traditionally difficult to incorporate two classes of diagnostic tests into a single platform. In this work, we demonstrate a microfluidic-based smartphone dongle that simultaneously measures concentration of hemoglobin and detects HIV antibodies. Specifically, we demonstrate how a previously published immunoassay device, which measured optical density of silver precipitation on gold colloids, can be expanded to quantitatively measure hemoglobin concentration via a colorimetric assay. By lysing whole blood components with CHAPS detergent, we achieved highly reproducible measurement of hemoglobin concentration with the device. We tested this dual test on 38 patient samples from Columbia University Medical Center. Compared with the Hemocue Hb 201+ analyzer, hemoglobin concentrations from our device were accurate within 1.2 g dL(-1), while the HIV immunoassay (in the presence of CHAPS detergent) showed 95% sensitivity and 95% specificity, comparable to our previous studies. This work demonstrates the feasibility of integrating two classes of diagnostic tests (a colorimetric-based quantitative measurement and an immunoassay based on silver precipitation on gold colloids) into a low-cost, fast, and low-power dongle that works with smartphones, and creates a novel dual panel with clinical utility for antenatal-care settings.

There exist relatively few drug classes on the market to treat dermatophyte infections. This investigation was designed to develop and validate high-throughput methodology for screening and confirmation of chemicals for activity against Trichophyton tonsurans. Growth characteristics were examined on two platforms (96- and 384-well) in three media at eight spore concentrations over a period of up to 120 h. Microspectrophotometry was used to automate plate reads. The 384-well platform was used to screen more than 7000 compounds from six chemical libraries. Z-scores for optical density relative to positive growth controls were used to flag compounds of interest and activity confirmed in separate assays. The final conditions selected for both screening and confirmation with minimum inhibitory concentration (MIC) determination were growth for 48 h at 32 °C in SabDex with 1 × 10(4) spores per reaction. Sensitivity and specificity averaged 99.2% (range, 95.2%-100%) and 99.8% (range, 99.1%-100%), respectively. MICs for known antifungals were similar to those reported by others using Clinical and Laboratory Standards Institute methods. Several novel compound classes were identified to have activity against T. tonsurans with potency comparable to known antifungals. A robust, reproducible assay is described that permits high-throughput screening in T. tonsurans.

The biological activity of the catholyte and anolyte of double distilled water was studied in experiments on the germination of wheat grains in the period from March to May. The activity of the solutions, which was characterized by a growth index, was high early in this period, then decreased almost to zero in the middle of the period, and then increased to about the initial value by the end of the period. Throughout, the efficiency of the anolyte of double distilled water generally exceeded the efficiency of the catholyte. Early and late in the period, the stimulatory effect of the anolyte exceeded that of the catholyte by a factor of 5–5.5. The changes in the biological activity of the catholyte and anolyte of double distilled water were also compared with the changes in the biological activity of the catholyte of nutrient medium M9. The stimulatory effect of the catholyte of the nutrient medium was evaluated from the change in the growth of E. coli cells. Early in the period at a cultivation temperature of 20°C, the stimulatory effect determined from the increase in the optical density of the cell suspension in the experiment with respect to a reference value was 55–60%. Next, the stimulatory effect decreased almost to zero in the middle of the period and increased to approximately initial value by the end of the period. It was assumed that the physicochemical mechanisms of action of the catholyte and anolyte of double distilled water on the wheat seed germination and of the catholyte of the nutrient medium on E. coli cell growth are of different nature.

The medium formulation and robust process modeling for anti-HIV peptide (T-20) production by recombinant Escherichia coli overexpression were studied by employing a crossed experimental design. The crossed design, a mixture design combined with process factor (induction duration), was used to find the optimal medium formulation and process time. The optimal settings for three major components (7.75 mL of NPK sources, 5.5 mL of glucose, and 11.75 mL of MgSO4) characterized by %T-20 (14.45%), the proportion of peptide to the total protein, were observed in a total of 100 mL of medium inducted at an optical density of 0.67 with 0.7 mM isopropyl-beta-D-thiogalactopyranoside) for a 3-h induction duration at shake-flask scale. These conditions were further investigated to find robust process conditions (8.2 mL of NPK sources, 5.6 mL of glucose, and 11.3 mL of MgSO4, and a 3.5-h induction duration time) for T-20 production (13.9%) by applying propagation of error.

BACKGROUND: Platelet concentrates (PCs) contain non-transferrin-bound iron (NTBI) owing to the displacement of iron from plasma-derived transferrin by citrate. NTBI in the PC medium supports the growth of Staphylococcus epidermidis. The possibilities of lowering the level of NTBI have been studied with the aim to inhibit the growth of S. epidermidis in the PC medium. STUDY DESIGN AND METHODS: NTBI in PC supernatants was determined by a chelation method and by the bleomycin-detectable iron assay. Iron binding by transferrin was determined by spectrophotometry. The growth of inoculated S. epidermidis in PC supernatants was monitored by optical density and determination of viable counts. RESULTS: Bicarbonate enhanced in a dose-dependent manner transferrin iron binding in citrate-containing solutions, including citrated plasma and PAS-II. The use of a modified anticoagulant supplemented with bicarbonate effectively lowered the level of NTBI and inhibited bacterial growth in citrated plasma. Supplementation of bicarbonate to the additive solution to increase the ratio of bicarbonate to citrate in a reconstituted PC medium further inhibited bacterial growth. Maintenance of stable pH and bicarbonate level in the reconstituted medium necessitated storage under 5 percent CO2. CONCLUSIONS: The relatively low bicarbonate level in PC medium promotes iron displacement by citrate from plasma-derived transferrin. The appearance of NTBI can be decreased and iron-dependent bacterial growth can be inhibited by increasing bicarbonate level in citrated plasma and PC medium. To achieve the same beneficial effect in blood banking, other more practical ways to bind NTBI in a harmless form should be developed.

Fundus reflectance spectroscopy has proven to be a reliable method for objective, in vivo determination of the macular pigment optical density. This paper discusses the technique and reviews measurements, including the observed absence of an age effect.