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Rationale and Objectives The purpose of this study is to improve accuracy of near-term breast cancer risk prediction by applying a new mammographic image conversion method combined with a two-stage artificial neural network (ANN)-based classification scheme. Materials and Methods The dataset included 168 negative mammography screening cases. In developing and testing our new risk model, we first converted the original grayscale value (GV)-based mammographic images into optical density (OD)-based images. For each case, our computer-aided scheme then computed two types of image features representing bilateral asymmetry and the maximum of the image features computed from GV and OD images, respectively. A two-stage classification scheme consisting of three ANNs was developed. The first stage included two ANNs trained using features computed separately from GV and OD images of 138 cases. The second stage included another ANN to fuse the prediction scores produced by two ANNs in the first stage. The risk prediction performance was tested using the rest 30 cases. Results With the two-stage classification scheme, the computed area under the receiver operating characteristic curve (AUC) was 0.816 ± 0.071, which was significantly higher than the AUC values of 0.669 ± 0.099 and 0.646 ± 0.099 achieved using two ANNs trained using GV features and OD features, respectively ( P Conclusion This study demonstrated that applying an OD image conversion method can acquire new complimentary information to those acquired from the original images. As a result, fusion image features computed from these two types of images yielded significantly higher performance in near-term breast cancer risk prediction.

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.

Background HIV-1 incidence calculation currently includes recency classification by HIV-1 incidence assay and unsuppressed viral load (VL ≥ 1000 copies/mL) in a recent infection testing algorithm (RITA). However, persons with recent classification not virally suppressed and taking antiretroviral (ARV) medication may be misclassified. Setting We used data from 13 African household surveys to describe the impact of an ARV-adjusted RITA on HIV-1 incidence estimates. Methods HIV-seropositive samples were tested for recency using the HIV-1 Limiting Antigen (LAg)-Avidity enzyme immunoassay, HIV-1 viral load, ARVs used in each country, and ARV drug resistance. LAg-recent result was defined as normalized optical density values ≤1.5. We compared HIV-1 incidence estimates using 2 RITA: RITA1: LAg-recent + VL ≥ 1000 copies/mL and RITA2: RITA1 + undetectable ARV. We explored RITA2 with self-reported ARV use and with clinical history. Results Overall, 357 adult HIV-positive participants were classified as having recent infection with RITA1. RITA2 reclassified 55 (15.4%) persons with detectable ARV as having long-term infection. Those with detectable ARV were significantly more likely to be aware of their HIV-positive status (84% vs. 10%) and had higher levels of drug resistance (74% vs. 26%) than those without detectable ARV. RITA2 incidence was lower than RITA1 incidence (range, 0%-30% decrease), resulting in decreased estimated new infections from 390,000 to 341,000 across the 13 countries. Incidence estimates were similar using detectable or self-reported ARV (R2 > 0.995). Conclusions Including ARV in RITA2 improved the accuracy of HIV-1 incidence estimates by removing participants with likely long-term HIV infection.

Immunohistochemical analysis of somatostatin receptor 2 (SSTR2) provides important information regarding the potential therapeutic efficacy of somatostatin analogues (SSAs) in patients with neuroendocrine tumors. HER2 scoring has been proposed to interpret SSTR2 immunoreactivity but their reproducibility was relatively low because of its intrinsic subjective nature. Digital image analysis (DIA) has recently been proposed as an objective and more precise method of evaluating immunoreactivity. Therefore, in this study, we used DIA for analyzing SSTR2 immunoreactivity in pancreatic neuroendocrine tumors (PanNETs) to obtain its H score and "(%) strong positive cells" and compared the results with those of manually obtained HER2 scores. Membranous SSTR2 immunoreactivity evaluated by DIA was calculated by two scales as: "Membrane Optical Density" and "Minimum Membrane Completeness". PanNETs with HER2 score of > 2 demonstrated the highest concordance with results of "(%) strong positive cells" obtained by DIA when "Minimum Membrane Completeness" was tentatively set at 80%. The SSTR2 immunoreactivity, evaluated based on all scoring systems, was different between grades G1 and G2 in insulinoma but not in non-functional PanNETs. DIA provided reproducible results of SSTR2 immunoreactivity in PanNETs and yielded important information as to the potential application of SSAs.

The study involved an analysis of optical density of the maxillary and mandibular bone tissue based on cone-beam computed tomography data. It has been shown that the structure and bone tissue density depend on the severity of diabetes mellitus and complications. The results of the study revealed a significant decrease in the bone tissue optical density at the tooth necks in people suffering from diabetes mellitus, whereas fewer changes were manifested at the middle third of the dental roots. Minor changes or even an increase in the optical density were observed at the dental root tips.

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

Panretinal photocoagulation, an important treatment method in diabetic retinopathy, can affect macular pigment optical density, which has protective and antioxidant properties. As a result of this effect, the retina may become more sensitive to high-energy visible light.The current study assesses the effect of panretinal photocoagulation treatment on macular pigment optical density, which has essential functions for the retina.In this prospective clinical study, the colour perimetry method was used to measure macular pigment optical density. Thirty-six eyes of 36 participants with severe non-proliferative diabetic retinopathy without macular involvement were included in the study. Conventional panretinal photocoagulation treatments were applied at baseline, one month, two months, and at three months to the participants who clinically required this treatment. Macular pigment optical density and retinal thickness measurements were performed at baseline, months one, two, three and six.The mean macular pigment optical density reduction in the fovea over the six-months was 0.02 ± 0.02 logarithmic units (p 0.001). Similarly, the pericentral areas declined by 0.04 ± 0.03 logarithmic units (p 0.001). Mean central macular thickness and foveal thickness increased by 5.03 ± 5.02 μm and 2.78 (interquartile range 2-4) μm, respectively. In this study, correlation analysis shows that the laser energy applied was significantly and strongly correlated with reductions in macular pigment optical density (for the fovea and pericentral area respectively: r = -0.855, p 0.001; r = -0.895, p 0.001). Further, there were significant and strong correlations between the applied laser energy, and central macular thickness and fovea thickness (r = 0.751, p 0.001; ρ = 0.718, p 0.001, respectively).Panretinal photocoagulation may potentially cause a decrease in macular pigment density in proportion to the laser energy applied.

The sensitivity of pneumothorax diagnosis via handheld ultrasound is low, and there is no equipment suitable for use with life-threatening tension pneumothorax in a prehospital setting. This study proposes a novel technology involving optical fibers and near-infrared spectroscopy to assist in needle thoracostomy decompression. The proposed system via the optical fibers emitted dual wavelengths of 690 and 850 nm, allowing distinction among different layers of tissue in vivo. The fundamental principle is the modified Beer–Lambert law (MBLL) which is the basis of near-infrared tissue spectroscopy. Changes in optical density corresponding to different wavelengths (690 and 850 nm) and hemoglobin parameters (levels of Hb and HbO2) were examined. The Kruskal–Wallis H test was used to compare the differences in parameter estimates among tissue layers; all p-values were 2 levels relative to those observed in the vein and artery, all p-values were also

Aim: To report the optical characteristics of the fluid in an anterior chamber iris cyst. Method: A 26-year-old male presented with blurring of vision in his right eye for two months, without any other associated ocular complaints. His visual acuity was 6/ 9 on Snellen’s chart. On slit lamp examination, a small translucent pigmented cyst was noted inferiorly in the anterior chamber, struck on to the cornea at 6 o’clock periphery, without any feeder vessel. Anterior segment optical coherence tomography (OCT) revealed a cystic lesion with hyperreflective walls and hypo reflective lumen attached to the cornea, compressing the endothelium. Results: The optical density (OD) of the cyst fluid was determined using ImageJ, an open code Java-based image processing software. The OD of cyst fluid was found comparable to the anterior chamber fluid. Conclusion: Ultrasound biomicroscopy (UBM) and OCT are useful tools for the diagnosis of cystic lesions of the anterior segment. The innovative use of an OCT image and the ImageJ software to determine the optical density of the iris cyst may aid in the diagnosis and follow-up of such cases.

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.

Purpose There is robust evidence that higher macular pigment concentrations help reduce both veiling and discomfort glare in patients with or without ocular disease. We investigated whether there was also a relationship between macular pigment optical density (MPOD) and patient surveys about glare or ocular discomfort. Methods We measured MPOD psychophysically in 23 healthy subjects and administered the National Eye Institute Visual Functioning Questionnaire (VFQ-25). Responses for each survey question were sorted from low (no limitation) to high (very severe limitation). The median response for each question was determined, and independent t-tests were performed on the mean MPOD values for survey responses above and below the median. We also performed a non-parametric correlation analysis between MPOD and survey responses. Results While the median response was “no limitation” for most (22 of 25) survey questions, responses were slightly higher for two questions concerning ocular discomfort and one question related to driving at night. MPOD levels were significantly higher in subjects that reported no discomfort in or around their eyes than in those that reported mild discomfort. There was also a trend toward higher MPOD levels in subjects who reported that pain in or around their eyes never limited their activity as well as in subjects who reported no difficulty driving at night. Conclusion These preliminary findings are consistent with the well-established discomfort and glare hypotheses for MPOD. The current findings on subjective ocular discomfort in the absence of glare deserve further study.

OBJECTIVE The aim of the study was to conduct a comparative assessment of the optical density of bone tissue of the alveolar process of the jaws of rats in supraocclusive relationships of individual teeth in the age aspect. PATIENTS AND METHODS Materials and methods: The study was performed on 60 white laboratory rats. Rats were divided into control (30 individuals) and experimental (30 individuals) groups. According to the age of rats each group was divided into 3 subgroups (10 animals): young, mature and senile. In the experimental group, the state of supraocclusion was modeled by increasing the height of the lower right second molars placing a seal 1 mm high. Experimental animals were removed from the experiment on the 15th day through decapitation. The lower jaws were skeletonized, jaw blocks were sawn in the molar area. Bone mineral density was determined using optical densitometry. The statistical processing def i ned the average (M) and its error (m). The statistical signif i cance of the dif f erence in two independent groups was performed according to nonparametric criteria (Mann-Whitney U-test and W-Wilcoxon test). Statistical processing was conducted with the help of integrated package of statistical program AtteStat 12.0.5 for MS Excel. Dif f erences at p≤ 0.05 were considered statistically signif i cant. RESULTS Results: Statistical discrepancy is present in rats of mature and senile age, as well as between the indicators of all rats of the control and experimental groups (≤0.05). No signif i cant dif f erence was observed in young rats, but the indicators of the experimental group were 3.82% worse than in the control group. In senile rats, the density of the alveolar process decreased by 26.6%, in adult rats by 17.5%. CONCLUSION Conclusions: The presence of supraocclusive relationships of individual teeth causes a decrease in bone density of the alveolar process of the jaws in rats. The greatest loss of density among age groups in elderly rats.

AIM: To determine the relationship among the macular pigment optical density (MPOD), central macular thickness (CMT) and body mass index (BMI). METHODS: This is a comparative cross-sectional study performed in a single institution. Totally 210 volunteers who met the inclusion criteria were included in this study. The subject’s MPOD was measured using Macula Pigment Screener II (MPS II, by Electron Technology). CMT was measured with Spectral Domain Cirrus Optical Coherence Tomography (OCT), Cirrus (Model 4000, Carl Zeiss Meditec). The information of both MPOD and OCT from both eyes were recorded. The data was analysed using Microsoft® Excel, SPSS, and R (version 3.2.1; R Core Team 2015). RESULTS: There was significant positive correlation between MPOD and CMT (r=0.42, P

Introduction Medication-related osteonecrosis of the jaw (MRONJ) is a complication associated with the intake of osteomodifying agents (bisphosphonates, denosumab). At present, its frequency, according to various authors, may reach from one to 10 cases per 100 subjects. The literature describes the main factors in the pathogenesis of the disease. The prognostic signs of its development, which would allow timely diagnosis and prevention of the disease, remain not fully understood. Materials and methods The retrospective analysis was based on the results of a study of 52 patients with MRONJ who were treated at the Department for Maxillofacial Surgery at the Central City Hospital No. 23 in Yekaterinburg from January 2015 to December 2019 Multispiral computed tomography was used for visualization, quantitative and qualitative assessment of the jaw bone tissue. The optical density of the spongy substance was determined in Hounsfield units (HU) on the side opposite to the lesion. Results The analysis of the results of optical density showed that D1 bone type was not detected in any patient. We observed type D2 using CT in 5 cases in the central part of the lower jaw (9.61 %), in 9 cases in the central part of the upper jaw (17.3 %), as well as in the area of the angle of the lower jaw on 6 CT-scans (11.53 %). D3 and D4 bone types prevailed, D5 bone type was less common. The optical density of the structures under study was in the range from 229.8 ± 56.6 to 534.8 ± 155.4 HU. Thus, patients receiving osteomodifying therapy with bone types D3, D4, D5 are more at risk of developing MRONJ than patients with bone types D1 and D2. Conclusion It is advisable to include a mandatory MSCT with classification of bone types according to Misch and determine optical density of bone tissue in the examination protocols of such patients.

Currently, despite the wide variety of methods and tests for screening blood serum for antibodies to HCV, there are no reliable criteria that guarantee a reliable result. To date, the interpretation of the results of anti-HCV detection in samples with low CP values (low optical density in ELISA) remains one of the major tasks of laboratory diagnostics. Continuous improvement of analytical sensitivity and specificity of laboratory tests remains one of the priority tasks for manufacturers of modern test systems. The purpose of this article was to assess the specificity and sensitivity of the new Hepatitis ELISA-anti-HCV test system produced by Alkor Bio when compared with test systems from other manufacturers in settings with sera from real patients and in a series of control seroconversion panels. The article is intended for doctors of clinical laboratory diagnostics, epidemiologists, virologists, infectious disease specialists, students of medical and biological universities.

Introduction. Biofi lm-forming ability among Candida spp. on indwelling medical devices may have a negative infl uence on the outcome of invasive candidiasis in various groups of patients. Aim. The objective of this study was to evaluate the biofi lm-forming ability among Candida spp. isolated from clinical specimens in patients with hematological malignancies and patients without hematological malignancies. Materials and methods. Biofi lm production among Candida spp. was studied using XTT (Sigma-Aldrich, USA) reduction assay. Candida spp. were classifi ed as biofi lm-forming, having optical density equal to and more than 0.1, and non-biofi lmforming with optical density less than 0.1. Results. A total of 428 Candida spp. (C. albicans n = 192, C. parapsilosis n = 121, C. krusei n = 40, C. tropicalis n = 38, C. glabrata n = 37) were evaluated (172 from hematological patients, 256 from non-hematological patients, 361 from blood culture, 67 from other sterile specimens). Biofi lm-forming ability was detected among 179 (41.8%) Candida spp. with the same rate in hematological patients and non-hematological patients (41.9 % and 41.8 %, respectively). Biofi lm production predominated among non-C. albicans (52.5 %) compared to C. albicans (28.6 %, p = 0.001). Biofi lm production prevailed among C. tropicalis (89.5 %) and C. krusei (75 %) compared to C. parapsilosis (41.3 %), C. albicans (28.6 %), and C. glabrata (27 %, respectively, p Conclusion. Biofi lm-forming ability varied among the Candida spp. and prevailed among C. tropicalis and C. krusei. Biofi lm production among Candida spp. was detected with the same rate in hematological and non-hematological patients.

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 .

Background We tested the hypothesis whether there is a correlation between the echogenicity and calcium and water contents of carotid plaques. Patients and methods Ninety carotid befurcations from 45 deceased patients were removed during autopsy. Thirty-four plaques were categorized as homogenous echolucent (HEL), homogenous echogenic (HEG) and heterogenous (HE) plaques based on premortem B-mode image. Water content was expressed in % of wet weight. Ca was determined by proton-induced X-ray emission and expressed in ppm. Relative optical density of the B-mode images was analyzed offline using a computer program. Results HEL plaques had lower Ca content (medians and IQRs: 6,145 [4,465–6,536 ppm]) compared to HEG (74,100 [15,300–1,44,500−ppm]), P ≤ 0.001). HE plaques showed an intermediate calcium content (7,310 [4,840–9,920 ppm]) that was statistically not different from echolucent plaques. Water content of HEG plaques was statistically not different from HEL and HE (HEG:53.5 [35.5–64%], HEL: 73.5 [69.7–78.5%], HE: 70.6 [67.4–73.9%]). HEG plaques had the highest relative optical densities (196 [188–217%]). HEL and HE had similar relative optical densities (HEL: 176 [164–187%], HE: 164 [144–188%], respectively). A significant positive correlation was found between the Ca content and relative optical density of plaques. Conclusions Echogenicity of carotid plaques increases along with their calcium content. Water content may be an important factor in differentiation of different plaques.

The traditional needle cricothyroidotomy procedure is performed blindly without any medical equipment. Complications including posterior tracheal wall perforation, accidental vessel puncture, and missed tracheal puncture are reported. Therefore, we proposed a dual-wavelength fiber-optic technique based on the technique of near-infrared spectroscopy to assist operators performing needle cricothyroidotomy in a swine model. We embedded optical fibers in a 16-gauge intravenous needle catheter. Real-time data were displayed on an oscilloscope, and we used the program to analyze the data immediately. The change of optical density corresponding to 690-nm and 850-nm wavelengths and hemoglobin parameters (HbO2 and Hb concentrations) was analyzed immediately using the program in the laptop. Unique and significant optical differences were presented in this experiment. We could easily identify every different tissue by the change of optical density corresponding to 690-nm and 850-nm wavelengths and hemoglobin parameters (HbO2 and Hb concentrations). Statistical method (Kruskal-Wallis H test) was used to compare differences in tissues at each time-point, respectively. The p values in every tissue in optical density change corresponding to 690 nm and 850 nm were all p values in every tissue in Hb and HbO2 were also all

Yeast-like fungi of the genus Candida are causative agents of the infectious pathology of the mucous membrane of the gastrointestinal, respiratory, urogenital tracts and skin of mammals, sepsis, and disseminated infection in birds. The search and testing of multilevel algorithms for biofilm identification when exposed to chemotherapeutic and disinfectant drugs for blocking the synthesis or destruction of the intercellular matrix in the development of superficial, deep and systemic candidiasis of animals are relevant for developing and improving diagnostic and antiepidemic measures. It was established that the formation of biofilm heterogeneous structure comprises multiple stages implementing the processes of intercellular communication due to the synthesis of a polymer matrix composites. Optical microscopy revealed a three-dimensional structure of biofilms in the form of a dense network consisting of yeast cells, hyphal and pseudohyphalic forms surrounded by an intercellular polymer matrix. Candida spp. pathogenicity factors contribute to infection of susceptible species due to adhesion, invasion, secretion of hydrolases, dimorphism. Formation of mono-species or poly-species biofilms of microorganisms, including Candida spp., causes the development of superficial, deep and systemic candidiasis. Detection of a large amount of yeast and micellar phases in C. albicans and C. africana isolates was a differential sign of a significant degree of colonization of the mucous membranes of the larynx, pharynx, and tonsils in case of local and systemic pathologies in pigs. The results of studies of the biofilm heterogeneous structure and phenotypic signs of yeast-like fungi can be used in a comparative study of biological characteristics and the identification of common patterns and differential signs of microorganisms, optimization of mycological diagnostics, and also in the development of antimycotic drugs.

Aim: To determine the antibacterial activity and biofilm inhibitory activity of Nicotiana tabacum leaf extract against Streptococcus mutans isolated from oral cavity. Place and Duration of Study: Department of Microbiology, Faculty of Science, Imo State University, Owerri, Nigeria, between April and November 2019. Methodology: The study was carried out using the agar diffusion method for antibacterial activity and microtiter assay method for the biofilm inhibition effect. Results: All four extracts of hot water, ethanol, acetone and methanol tested against S. mutans had no antibacterial activity as no zone of inhibition was recorded. Likewise, all the extracts did not inhibit the formation of biofilm by the organism on glass. This is seen in the increase of the optical density (OD) values from 0.572 to 0.804 for water, 0.260 to 1.420 for ethanol, 0.216 to 0.626 for acetone and 0.236 to 0.725 for methanol extracts respectively. Conclusion: This study therefore indicates that N. tabacum does not have antibacterial and biofilm inhibitory against S. mutans. This also explains why a lot of tobacco users still suffer from dental caries and other oral infections caused by S. mutans.

The paper presents the results of a study of the surface and optical properties of the PM-1 polyimide film and the polyimide track membrane. For the study, polyimide (track) nuclear membranes manufactured by ION TRACK TECHNOLOGY FOR INNOVATIVE PRODUCT (it4ip, Belgium)) is used. The pore diameter is 200 nm, the pore density is 5 • 108 cm-1, and the thickness of the polyimide membrane is 25 μm. The data of IR spectroscopy are presented. It is shown that the decrease in the intensity of the peaks of the IR spectra of the membrane compared to the film is a consequence of the oxidative degradation of the polyimide after exposure to heavy ions and chemical etching. The data on the effects of heavy ion irradiation and chemical etching of a polyimide film to obtain a membrane on surface hydrophobicity / hydrophilicity are presented. The optical density of the film and track membranes is determined in the wavelength range of 350-950 nm. The optical density is measured in increments of 50 nm. It is shown that despite the strong difference in the spectral dependence of the optical density of the polyimide film and the track membrane, the optical density of the PM-1 film and the track membrane is quite low in the entire studied wavelength range and does not exceed 0.26 and 0.42, respectively.

This study assessed an enzyme-linked immunosorbent assay (ELISA) based assay to detect Salmonella in swine as a potential tool to predict the presence of Salmonella in swine carcasses. The following samples were collected from 10 swine batches: blood (n = 100); environment (barn floor, n = 10, and lairage floor, n = 10); meat juice (n = 100, obtained after defrosting of diaphragm); tonsils (n = 100); mesenteric lymph nodes (MLNs) (n = 100); and carcasses after bleeding (n = 100), after singeing (n = 100), after evisceration (n = 100), and after final rinsing (n = 100). Blood and meat juice were subjected to ELISA to detect antibodies against Salmonella, and other samples were subjected to Salmonella detection by ISO 6579. Salmonella was detected in 3 samples from barn floors, 7 lairage floors, 45 tonsils, 43 MLNs and in 3 carcasses. Based on ELISA, Salmonella positive samples were: 86 and 46 blood serum (20% and 40% cut-offs) and 68 and 46 meat juice (20% and 40% cut-offs). Optical density readings from blood serum and meat juice presented a high and significant correlation (r = 0.93, p

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.

Background: To compare the optical density of iris pigment epithelium (ODIPE) and iris stromal thickness (IST) measurements in patients having pseudoexfoliation syndrome (PXS) and age-gender matched participants. Methods: This is a cross-sectional study. Patients with PXS were enrolled in the study group. Age and gendermatched healthy subjects with no evidence of PXS were recruited as controls. After a comprehensive ophthalmological evaluation, the anterior segment images were acquired using anterior segment spectral-domain optical coherence tomography (AS SD-OCT). The acquired pictures were further analyzed using the ImageJ program. Two investigators measured the ODIPE and the IST of the subjects, and the repeatability and reproducibility were checked. SPSS program was used for statistical analysis. Results: The PXS group was comprised of twenty-two eyes (n = 22 patients), and the control group contained twenty-six eyes of 26 age and gender-matched healthy subjects. The mean temporal ODIPE of the study group was found to be decreased significantly in comparison to the mean temporal ODIPE of the control eye (p = 0.018). Both the mean nasal (N) and temporal (T) ISTs of the PEX eyes were thinner than the control eyes (p = 0.006 and p = 0.002, respectively). The mean baseline IOP was found to significantly negatively correlate with the ODIPE in the PEX group at both N and T sides (r = -0.531, p = 0.011 and r = -0.685, p < 0.001, respectively). Conclusion: The pupillary margin IPE was found more depigmented, and the mean N and T IST were significantly thinner in the PEX group by comparison with the age-gender matched healthy controls. The mean baseline IOP was negatively correlated with the pupillary margin's IPE pigmentation degree in patients with PXS.

Prompt COVID-19 diagnosis is urgently required to support infection control measures. Currently available serological tests for measuring SARS-CoV-2 antibodies use different target antigens, although their sensitivity and specificity presents a challenge. We aimed to develop an “in-house” serological ELISA to measure antibodies against SARS-CoV-2 by combining different protein antigens. Sera (n = 44) from COVID-19-confirmed patients were evaluated against different SARS-CoV-2 protein antigens and all potential combinations using ELISA. Patients’ sera were also evaluated against commercially available ELISA diagnostic kits. The mixture containing RBD 2.5 μg/mL, S2 1 μg/mL and N 1.5 μg/mL was found to be the most potent. Plates were incubated with patients’ sera (1:100), and goat anti-human alkaline phosphatase-conjugated IgG, ΙgM and IgA antibody was added. The cut-off value for each assay was determined using the mean optical density plus two standard deviations of pre-pandemic controls. The “in-house” ELISA displayed 91% sensitivity and 97% specificity for IgG antibodies, whereas its sensitivity and specificity for IgM and IgA were 75% and 95% and 73% and 91%, respectively. The “in-house” ELISA developed here combined three SARS-CoV-2 antigens (RBD, S2 and N) as capture antigens and displayed comparable and even higher sensitivity and specificity than otherwise quite reliable commercially available ELISA diagnostic kits.

To pursue the least corneal implication during cataract surgery, this study aimed to monitor corneal wound injury after cataract surgery with a novel method. The prospective cohort study involved thirty-two patients, who were assessed by a Scheimpflug tomography AxL® (Oculus GmbH, Wetzlar, Germany) via the following two kinds of indices: whole corneal optical density (COD) and corneal thickness (CT), two weeks before and one month after cataract surgery. The results of the COD revealed that corneal annuli 0.0–2.0 mm and 2.0–6.0 mm, and the average and maximal values at the incisional site significantly increased postoperatively. Also, the anterior and central stroma of 0.0–2.0 mm, and all three depths of 2.0–6.0 mm, increased remarkably after the operation. For the CT, all ranges of diameters plus incisional sites showed significant increases postoperatively. Furthermore, we analyzed the differences (delta) of COD and CT between pre- and post-operation, and found significant correlations between the delta of COD and the delta of CT, regarding annuli 0.0–2.0 mm, 2.0–6.0 mm, and 6.0–10.0 mm, but no correlation at the incisional site, with either average density or maximal density, was detected. We concluded that whole COD and CT, especially at the central zones of the cornea (annulus &lt, 6 mm), are both valuable parameters in the assessment of corneal damage post-cataract surgery, and are independent indices at the incisional site.

Amethod for assay of total isoflavonoids in an oil extract of the osage orange by spectrophotometry in the visible part of the spectrum was developed, based on selective interaction of aluminum chloride solution with compounds of flavonoid structure. The results were validated by their demonstrated specificity and the linear relationship between optical density and product concentration, with a correlation coefficient of r = 0.9988, with satisfactory reproducibility with a relative error of the mean result of ±2.57%.

Objectives Heparin-induced thrombocytopenia is a recognized concern in patients on extracorporeal life support. The purpose of this study was to evaluate the applicability of an enzyme-linked immunosorbent assay optical density threshold less than 1 to rule out heparin-induced thrombocytopenia in patients on extracorporeal membrane oxygenation. Design Retrospective, single-center study. Setting Patients were recruited from a prospectively maintained database of all patients on extracorporeal membrane oxygenation from 2012 to 2018 at a tertiary referral center. Patients Forty-seven patients on extracorporeal membrane oxygenation support. Interventions The primary objective was to evaluate the application of enzyme-linked immunosorbent assay optical density thresholds and the serotonin release assay in patients on extracorporeal membrane oxygenation. Patients were divided into two cohorts, serotonin release assay negative and serotonin release assay positive. In order to perform a sensitivity and specificity analysis of enzyme-linked immunosorbent assay optical density thresholds, heparin-induced thrombocytopenia negative was defined as an optical density less than 1.0 and heparin-induced thrombocytopenia positive as an optical density greater than or equal to 1.0. Measurements and main results Utilizing the prespecified optical density thresholds, a specificity and negative predictive value of 89% and 95% were achieved, respectively. Conclusions This assessment has helped to identify optical density thresholds for patients undergoing extracorporeal membrane oxygenation. Our data suggest that an optical density threshold of 1.0 may aid clinicians in objectively ruling out heparin-induced thrombocytopenia without sending a confirmatory serotonin release assay. Increasing the optical density threshold to 1.0 resulted in a high specificity and negative predictive value.

Objective: To investigate the effect of ND:YAG laser cap- sulotomy on macular pigment optical density(MPOD) in patients with posterior capsule opacification(PCO). Material and Methods: This prospective and single-arm clinical trial included 38 participants with pseudophakic eyes. MPOD, choroidal(CT) and central macular thick- nesses(CMT), as well as anterior chamber parameters, were measured be- fore ND:YAG laser and the measurements were repeated after one week, one month and two months. The changes in the parameters and correla- tions were evaluated statistically. Results: There were significant de- creases in the MPODs of the fovea and pericentral during the study (p0.6, p0.6, p0,6, p0,6, p

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 (

In situ measurement to determine mammalian cell number in a non-invasive, non-destructive and reagent-free manner is needed to enable continuous cell manufacturing. An analytical method is presented for non-invasive cell counting by conducting multiwavelength spectral analysis of mammalian cells achieving a minimal detectable cell count of 62,500 at 295 nm. Light absorbance was insensitive to culture volume, giving an absolute cell count rather than a concentration. The activation state of cells was also considered. The study was extended to quantification within polymeric microcapsules as an advanced substrate for mammalian cell growth in bioreactor formats and resulted in an offset directly correlating with the absorbance maxima of the polymer. These studies provide feasibility for optical density as a simple end point to indirectly quantify mammalian cell number for continuous monitoring of cell cultures., METHOD SUMMARY Cell type and anchorage-dependent cells versus suspension cells, as well as cell state (activated vs unactivated), were assessed for changes in optical density to develop an analytical method for cell counting. A multiwavelength spectral analysis was conducted from 200 to 800 nm with a 5-nm step size to detect peak and minimal detectable cell absorbance. The optical density of cell-laden polymeric microcapsules was also evaluated.

We performed retrospective analysis of cytological and histological smears from 52 women examined and treated in N.N. Petrov National Medical Research Center of Oncology, Ministry of Health of Russia. We have developed a simplified method of densitomorphometry using cytological smears stained with hematoxylin and eosin to verify the diagnosis of cervical intraepithelial neoplasia (CIN). We have identified threshold values for the differentiation between CIN-1/2 and CIN-3: integrated optical density of 4.5 C and percentage of atypical nuclei with a ploidy level ≥5 C of 40 %. The new method verified the morphological diagnosis of CIN in 18 out of 52 patients (34.6 %), including those with discrepant results of cytology and histology. The method can be also used to verify the cytological diagnosis of CIN-3 in patients with negative histology.

Andropause, the culminating phase of male ageing, is characterized by deregulation of the hypothalamic-pituitarygonadal axis and low circulating free testosterone. The aim of this study was to investigate the immunohistomorphometric characteristics of the pituitary gonadotropic i.e. follicle-stimulating hormone (FSH) and the luteinizing hormone (LH) producing cells after testosterone application in a rat model of the andropause. Middle-aged Wistar rats were divided into orchidectomized (ORX; n=8) and testosterone treated orchidectomized (ORX+T; n=8) groups. Testosterone propionate (5 mg/kg b.m./day) was administered for three weeks, while the ORX group received the vehicle alone. Immunohistochemically stained FSH and LH cells underwent morphometric and optical density-related analysis, while circulating concentrations of the sex steroids were measured by immunoassays. Serum concentrations of testosterone and estradiol were significantly (pi.e. this parameter of FSH and LH cells was significantly (p

Graphical abstract, The use of sulfate reducing bacteria (SRBs) in laboratory studies is a common approach for investigating microbially influenced corrosion (MIC). The characteristic formation of black iron sulfide precipitates during SRB growth, however, preclude the use of traditional spectrophotometric approaches for capturing growth data instead necessitating labour-intensive or technically specialized approaches. As such, an understanding of SRB growth responses to experimental conditions is often missing from MIC studies. Bernardez and de Andrade Lima (2015) have outlined a spectrophotometric approach for estimating SRB cell mass via the addition of HCl. This method has potential for the study SRB growth however its applicability is currently limited by the use of large aliquot volumes (45 mL), which restrict the number of timepoints that can sampled from one culture, and the extensive time devoted to cell preparation prior to OD readings. • We demonstrate an improved method for capturing SRB growth data via spectrophotometry following acidification. We incorporate lower sample volumes and adapt the method described in Bernardez and de Andrade Lima (2015) to a high throughput microtiter plate approach that increases the efficiency of this method and its applicability to growth rate studies. • Our results allay theoretical concerns that acidification may distort growth rate analysis by impacting cells differently depending on their metabolic state. • We further demonstrate that this method (acid-amended OD measurements) is more accurate and far more cost efficient than traditional methods (dilution spread-plate counting) and popular molecular methods (quantitative PCR) currently in use in SRB growth research.

Background: The aim of this study was to determine the intra-session repeatability and inter-examiner reproducibility of the colour perimetry technique when assessing in vivo macular pigment optical density in age-related macular degeneration patients. Methods: Age-related macular degeneration patients were classified into four groups: early age-related macular degeneration, intermediate age-related macular degeneration, atrophic age-related macular degeneration and neovascular age-related macular degeneration after undergoing fundus photography (TRC 50DX type IA) and spectral-domain optical coherence tomography analysis (Topcon 3D-2000). Central fixation was confirmed in all patients using the MP-1 microperimeter (Nidek, Padua, Italy). To analyse repeatability, one examiner obtained three consecutive macular pigment optical density measures with MonCV3 device (Metrovision, Perenchies, France). To study agreement between two observers, a second examiner performed another macular pigment optical density measurement in random order. Within-subject standard deviation, coefficient of variation, and intraclass correlation coefficient data were obtained. Results: Fifty two (32 females and 20 males) consecutive age-related macular degeneration patients having a mean age of 71.5 ± 8.2 years were recruited. Six had early age-related macular degeneration, 25 had intermediate age-related macular degeneration, 10 had atrophic age-related macular degeneration and 11 had neovascular age-related macular degeneration. For repeatability, coefficient of variation values ranged from 22.3% (neovascular age-related macular degeneration) to 41.0% (atrophic age-related macular degeneration) and intraclass correlation coefficient values from 0.52 (intermediate age-related macular degeneration) to 0.79 (neovascular age-related macular degeneration). For agreement between two examiners, coefficient of variation values ranged from 20.1% (intermediate age-related macular degeneration) to 37.8% (neovascular age-related macular degeneration) and intraclass correlation coefficient values from 0.61 (neovascular age-related macular degeneration) to 0.80 (atrophic age-related macular degeneration). Conclusion: The reliability (intra-session repeatability and inter-examiner reproducibility) of colour perimetry technique to assess macular pigment optical density in age-related macular degeneration patients is only moderate. Thus, it cannot be recommended to be performed when evaluating and monitoring age-related macular degeneration patients in the daily clinic.

MRSA (Methicillin-Resistant Staphylococcus aureus) arises due to excessive use of methicillin antibiotics and complications from all medical practices that have been carried out lately. The prevalence of MRSA tends to increase and its ability to form biofilms so that it has the potential to significantly increase mortality and morbidity. Biofilms are considered one of the microbial virulence factors. Biofilm formation in S. aureus is regulated by the expression of PIA which mediates attachment between cells to cells and is a product of the ABDC ica gene. This study aims to determine the ability of biofilm formation as one of the virulence factors in MRSA compared to MSSA (Methicillin-Sensitive Staphylococcus aureus) . its relationship to the presence of A and D ica genes as biofilm coding genes. Biofilm formation assay on MRSA and MSSA using the Microtiter Plate (MtP) method and the A/D gene detection assay performed by PCR method. The results showed that the incubation end value of Optical Density (OD) for MSSA1 (0.75), MSSA2 (0.46), MRSA1 (0.53) isolates according to the formula were interpreted as moderate biofilm producer. The conclusions of this study were all of the test isolates (MSSA1, MSSA2 and MRSA1) were able to form a biofilm. Distribution of ica A and ica D genes in MSSA 1 and MSSA 2 was varied while MRSA1 had the ica A and ica D genes.

Pseudomonas aeruginosa and Streptococcus pyogenes are the most common pathogens to humans and are able to form a biofilm following ineffective precautionary approach. Biofilm is defined as a surface-attached community of bacterium embedded in an extracellular matrix which leads to tremendous problems in the environment, among humans and animals. This study aims to investigate the ability of P. aeruginosa and S. pyogenes to form biofilms in 96-well plate before further study in antibiofilm will be done. Initially, the 96-well plate was added with 100 μl of overnight P. aeruginosa culture with optical density (OD) 0.1 and S. pyogenes culture with OD 0.05. The cultures were incubated for 7 days at 37 °C to justify the formation of biofilm. Subsequently, stained blue biofilm was detached from the plate by using 95% ethanol. Biofilms were finally measured using a micro plate reader at 570 nm and were classified based on the adherence strength formula. P. aeruginosa and S. pyogenes biofilms strongly adhered to the plates on days three, four, five and six. Interestingly on day three, biofilms showed the highest formation. However, moderate biofilm formation onto the plates by both P. aeruginosa and S. pyogenes were observed on day two, but non-adherence was observed on days one and seven. Day three is the optimum cultivation period for P. aeruginosa and S. pyogenes to switch into a strong biofilm in microtiter plate and could be beneficial for antibiofilm experiments.

Clinical instruments using Scheimpflug image-based methods to obtain optical sectional images of the cornea have been introduced in recent years along with proposals that it should be possible to routinely and reliably measure the optical density (referred to as the densitometry) of the human cornea in situ. Such a concept is reviewed from the perspective of what might be considered as the basic principles underlying the understanding of corneal transparency (from the 1950's) and the progressive changes in these ideas from subjective slitlamp-based clinical observations from the late 1960's, especially in contact lens wearers. Much more has been learned about the overall macrostructure (including corneal thickness) and the ultrastructure of the cornea from contemporary studies in the 1990's, and these aspects of the cornea will be reviewed alongside consideration of the methods of assessing the optical characteristics of the cornea in the living eye. From these perspectives, in this review systematic consideration will be given to what objective (quantitative) output one of these Scheimpflug-based systems provides and how this information might be actually related to corneal transparency characteristics that might be observed clinically, particularly after long-term contact lens wear.

Background: To evaluate macular pigment optical density (MPOD) after bimanual femtosecond laser-assisted cataract surgery (FLACS) compared to standard bimanual phacoemulsification (B-MICS). Methods: A prospective, case matched, comparative cohort study conducted at the Institute of Ophthalmology, University of Modena and Reggio Emilia (Italy); 30 eyes underwent bimanual FLACS with low-energy Ziemer LDV Z8 (FLACS) and 30 underwent B-MICS standard technique (B-MICS). All interventions were conducted by the same expert surgeon. MPOD using the Macular Pigment Screener II (MPS II) was evaluated at baseline, 7 and 30 days after surgery. As secondary outcomes, we considered best corrected visual acuity (BCVA) and central macular thickness (CMT) obtained using optical coherence tomography. Results: In all cases, a BunnyLens AF IOL was safely implanted in the capsular bag through a 1.4 mm incision. We found a significant reduction in MPOD in both groups at 7 and 30 days; 0.16±0.14 and 0.10±0.12 (FLACS) and 0.18±0.13 and 0.15±0.14 (B-MICS), respectively (P

Purpose To investigate the optical density (OD) characteristics and clinical relevance of subretinal fluid in choroidal melanoma and choroidal metastasis. Methods Medical records of patients with choroidal melanoma and choroidal metastasis who underwent optical coherence tomography examinations at diagnosis before any intervention and whose optical coherence tomography scans showed sufficient subretinal fluid for sampling were reviewed. The highest quality B-scan containing subretinal fluid was analyzed. Optical density measurements obtained using ImageJ and optical density ratios (ODRs) were calculated as subretinal fluid OD divided by vitreous OD. Patient details and diagnosis were masked during measurements. Nonparametric tests for independent samples were used to detect differences in ODR between groups. Results Of the 39 cases of choroidal tumors that met the inclusion criteria, 14 were diagnosed as metastases and 25 as malignant melanoma. There were no significant differences between the groups in age, optical coherence tomography acquisition and parameters of quality, and vitreous OD. Optical density ratio values were significantly lower in metastases cases (mean 0.68, SD ±0.18) than in melanoma cases (0.95 ± 0.33, P = 0.006). Receiver operating characteristic curve analysis yielded an optimal cutoff of ODR = 0.771 (sensitivity = 78.6%, specificity = 72.0%). Conclusion Optical density ratio can serve as an additional test to differentiate between choroidal melanoma and choroidal metastases.