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Clinical Ophthalmology (Auckland, N.Z.) 2018Multifocal intraocular lenses (IOLs) can be associated with unwanted visual phenomena, including halos. Predicting potential for halos is desirable when designing new...
PURPOSE
Multifocal intraocular lenses (IOLs) can be associated with unwanted visual phenomena, including halos. Predicting potential for halos is desirable when designing new multifocal IOLs. Halo images from 6 IOL models were compared using the Optikos modulation transfer function bench system and a new high dynamic range (HDR) system.
MATERIALS AND METHODS
One monofocal, 1 extended depth of focus, and 4 multifocal IOLs were evaluated. An off-the-shelf optical bench was used to simulate a distant (>50 m) car headlight and record images. A custom HDR system was constructed using an imaging photometer to simulate headlight images and to measure quantitative halo luminance data. A metric was developed to characterize halo luminance properties. Clinical relevance was investigated by correlating halo measurements to visual outcomes questionnaire data.
RESULTS
The Optikos system produced halo images useful for visual comparisons; however, measurements were relative and not quantitative. The HDR halo system provided objective and quantitative measurements used to create a metric from the area under the curve (AUC) of the logarithmic normalized halo profile. This proposed metric differentiated between IOL models, and linear regression analysis found strong correlations between AUC and subjective clinical ratings of halos.
CONCLUSION
The HDR system produced quantitative, preclinical metrics that correlated to patients' subjective perception of halos.
PubMed: 29503526
DOI: 10.2147/OPTH.S152201 -
ACS Omega Oct 2023To clarify the coal structure, spatial distribution, and controlling factors of the 2# coal seam in Jiaozuo mining, the drilling coal samples were collected to observe...
To clarify the coal structure, spatial distribution, and controlling factors of the 2# coal seam in Jiaozuo mining, the drilling coal samples were collected to observe the coal type and coal structure. The coal macerals were identified by a MPVSP microscope photometer, and the spatial characteristics of the coal structure were obtained through interpreting deep lateral resistivity logging, natural gamma ray logging, density logging, and acoustic logging curves. The influence of coal properties, burial depth, geological stress, and faults on the coal structure were discussed correspondingly. The results exhibit that granulitic-mylonite coal was most developed in the 2# coal seam, followed by primary coal and cataclastic coal; the coal type was dominated by semibright coal, followed by clarain and semidull coal. Granulitic-mylonite, cataclastic, and primary coals were the main components of clarain, semibright coal, and semidull coal, respectively. Higher vitrinite and organic matter contents were conducive to the development of granulitic-mylonite. The coal structure combinations were spatially varied, and the granulitic-mylonite combinations were the most common. Granulitic-mylonite coal was developed in the east and south parts of the study area, and the coal structure was fragmented with a greater burial depth and larger thickness. The geological stress is the fundamental cause of coal structure damage as well as the cutting of faults.
PubMed: 37901576
DOI: 10.1021/acsomega.3c04643 -
Toxicological Research Apr 2017Hexavalent chromium is a bio accumulative toxic metal in water and fish. It enters aquaculture ponds mainly through anthropogenic sources. Hexavalent chromium...
Hexavalent chromium is a bio accumulative toxic metal in water and fish. It enters aquaculture ponds mainly through anthropogenic sources. Hexavalent chromium concentrations and its effects on the morphology and behavior of were investigated from four aquaculture ponds for 12 weeks. Chromium was measured using diphenyl carbohdrazide method; alkalinity and hardness were measured using colometric method and analyzed with Bench Photometer. Temperature and pH were measured using pH/EC/TDS/Temp combined tester. Temporal and spatial replications of samples were done with triplicates morphological and behavioural effects of the metal on fish were observed visually. Chromium ranged from no detection to 0.05 mg/L, alkalinity 105 to 245 mg/L, hardness 80 to 165 mg/L, pH 6.35 to 8.03 and temperature 29.1 to 35.9°C. Trend in the chromium concentrations in the ponds is natural > earthen > concrete > collapsible. There was a significant difference ( < 0.05) in chromium, alkalinity, water hardness, pH and temperature among the four ponds. Significant positive correlation also existed between alkalinity, water hardness, pH, with chromium. Morphological and behavioural changes observed in the fish include irregular swimming, frequent coming to the surface, dark body colouration, mucous secretion on the body, erosion of gill epithelium, fin disintegration, abdominal distension and lethargy. High chromium concentration in natural pond was due to anthropogenic run-off of materials in to the pond. Acidic pH, low alkalinity, low water hardness also contributed to the high chromium concentration. Morphological and behavioural changes observed were attributed to the high concentrations, toxicity and bio accumulative effect of the metal. Toxicity of chromium to fish in aquaculture could threaten food security. Watershed best management practices and remediation could be adopted to reduce the effects of toxicity of chromium on pond water quality, fish flesh quality and fish welfare.
PubMed: 28503260
DOI: 10.5487/TR.2017.33.2.119 -
Journal of Anaesthesiology, Clinical... 2022Blood loss in neurosurgical procedures can be rapid and tremendous leading to consequential hemodynamic instability. HemoCue is a portable photometer used for the...
BACKGROUND AND AIMS
Blood loss in neurosurgical procedures can be rapid and tremendous leading to consequential hemodynamic instability. HemoCue is a portable photometer used for the measurement of blood hemoglobin concentration. Using this point of care device, we contemplated this study to assess the reliability of HemoCue for suction hemoglobin determination and calculation of surgical blood loss by comparing with the gold standard laboratory Coulter Counter method in patients undergoing neurosurgical procedures.
MATERIAL AND METHODS
This prospective observational study was conducted in 233 patients undergoing elective neurosurgical procedures in the age group of 18 to 60 years and having preoperative hemoglobin (Hb) values above 9 g/dL. Values of preoperative hemoglobin, suction hemoglobin, and volume in the suction container were used to obtain the estimated blood loss. The normality of the data was tested using the Kolmogorov Smirnov test. Bland Altman analysis was used to test the reliability of HemoCue in estimating hemoglobin and blood loss with reference to the gold standard laboratory Coulter Counter automated hematology analyzer.
RESULTS
Median blood loss calculated in our study using HemoCue was 554.65 mL with an interquartile range of 336.81 mL to 982.39 mL. Laboratory counter method estimated median blood loss was 533.37 mL with an interquartile range of 335.21 mL to 994.73 mL. The majority of the data obtained and analyzed using the Bland and Altman analysis method were within a 95% confidence interval.
CONCLUSION
The HemoCue method is a reliable method and henceforth can be used to estimate blood loss in suction fluid in patients undergoing neurosurgical procedures.
PubMed: 36778832
DOI: 10.4103/joacp.JOACP_638_20 -
Measurement : Journal of the... May 2021Respirators are one of the most useful personal protective equipment which can effectively limit the spreading of coronavirus (COVID-19). There are a worldwide shortage...
Respirators are one of the most useful personal protective equipment which can effectively limit the spreading of coronavirus (COVID-19). There are a worldwide shortage of respirators, melt-blown non-woven fabrics, and respirator testing possibilities. An easy and fast filtering efficiency measurement method was developed for testing the filtering materials of respirators. It works with a laser-based particle counting method, and it can determine two types of filtering efficiencies: Particle Filtering Efficiency (PFE) at given particle sizes and Concentration Filtering Efficiency (CFE) in the case of different aerosols. The measurement method was validated with different aerosol concentrations and with etalon respirators. Considerable advantages of our measurement method are simplicity, availability, and the relatively low price compared to the flame-photometer based methods. The ability of the measurement method was tested on ten different types of Chinese KN95 respirators. The quality of these respirators differs much, only two from ten reached 95% filtering efficiency.
PubMed: 33642662
DOI: 10.1016/j.measurement.2021.109173 -
Applied Optics Apr 2021The Ocean Color component of the global Aerosol Robotic Network (AERONET-OC) utilizes CE-318 sun photometers modified for above-water radiometry from fixed structures...
The Ocean Color component of the global Aerosol Robotic Network (AERONET-OC) utilizes CE-318 sun photometers modified for above-water radiometry from fixed structures such as oil rigs, lighthouses, and service platforms. Primarily, AERONET-OC measurements allow determination of the water-leaving radiance required for the validation of ocean color satellite data products. One instrument from the AERONET-OC network, identified as AERONET #080, was studied in this work. A laser-illuminated integrating sphere of known radiance enabled determination of the linearity with flux and absolute radiance responsivity at multiple wavelengths within seven of the AERONET #080 filter bands. We compared the results to calibrations from the AERONET facility at the Goddard Space Flight Center of the National Aeronautics and Space Administration and from the Joint Research Centre of the European Commission. These results agree within the estimated mean comparison uncertainty of 1.88 % (=2). We also assessed these results using calibrated lamp-illuminated integrating spheres and observed a spectral dependence to the comparison results that is unexplained.
PubMed: 33983243
DOI: 10.1364/AO.419766 -
Poultry Science May 2024A total of 720 male Cobb 500 broiler chicks were used in a 5 treatment and 8 replicate experiment to explore dynamic changes in blood metabolites in response to...
A total of 720 male Cobb 500 broiler chicks were used in a 5 treatment and 8 replicate experiment to explore dynamic changes in blood metabolites in response to short-term nutrient depletion and repletion. Day old chicks were offered a corn and soybean meal-based common starter diet from d1 to 14 that was formulated to meet all nutrient requirements of the birds. From d15 to 17, the experimental diets were offered, before returning all groups to a common diet from d18 to 20, at which point the experiment was terminated. A total of 5 experimental diets were designed. A standard grower diet served as a control and was offered to 1 of the 5 groups of chicks. The additional 4 experimental groups comprised diets that were low in digestible phosphorus (P), total calcium (Ca), crude protein and digestible amino acids (AA) or apparent metabolizable energy (AME). The common grower diet that was offered from d18-20 was designed to be nutritionally complete and was intended to explore dynamic response to nutrient repletion. Blood was drawn from 8 chicks per treatment at time 0 (immediately prior to introduction of the experimental diets) and then again 3, 6, 12, 24, and 48h after introduction of the nutrient depleted diets. Additionally, blood was drawn 3, 6, 12, 24, and 48h after the introduction of the nutritionally complete common grower diet. Chicks were not sampled more than once. Feed intake, body weight and feed conversion ratio (FCR) were assessed on d14, 17, and 20. Blood metabolites were analyzed using the iSTAT Alinity V handheld blood analyzer, the Vetscan VS2 Chemistry Analyzer and the iCheck Carotene Photometer. Live performance metrics were not affected by the short-term nutrient depletion and all chicks grew normally throughout the experiment. The diet with low digestible P generated a rapid temporary decrease in plasma P and an increase in plasma Ca, that were returned to baseline following the re-introduction of the common grower feed. Introduction of the diet with low total Ca resulted in a significant increase in plasma P, effects which were also mitigated during the nutrient repletion phase. Total plasma protein, albumin and uric acid (UA) were decreased, and plasma glucose increased, in the chicks that received the diet with low crude protein and digestible AA. There was a delayed increase in aspartate amino transaminase (AST) associated with the diets with low digestible P and low AME. These results demonstrate the capacity of blood biochemistry to adapt to quantitative and qualitative changes in nutrient intake. Point-of-care analysis of blood biomarkers offers nutritionists a valuable opportunity to calibrate nutritional matrices for common dietary ingredients, zootechnical feed additives and to optimize diet phase changes. It can be concluded that many blood biomarkers are plastic to changes in diet nutrient density and offer an objective index for optimization of nutritional programs for commercial broiler production.
PubMed: 38823292
DOI: 10.1016/j.psj.2024.103859 -
The American Journal of Tropical... May 2018Undernutrition among under-five children is a public health concern in developing countries and has been linked with poor water, sanitation, and hygiene (WASH)...
Undernutrition among under-five children is a public health concern in developing countries and has been linked with poor water, sanitation, and hygiene (WASH) practices. This study aimed at assessing WASH practices and its association with nutritional status of under-five children in semi-pastoral communities of Arusha. The study was cross-sectional in design. Mother-child pairs from 310 households in four villages of Monduli and Longido were involved. Weight and height of children were measured using weighing scale and length/height board, respectively. Children's age was recorded using clinic cards. Hemoglobin level of each child was tested using Hemo Cue Hb 201 + photometer (HemoCue AB, Ängelholm, Sweden) machine. Structured questionnaire was used to gather information on WASH, child morbidity, demographic, and sociocultural characteristics. Prevalence of stunted, underweight, wasted, anemia, and diarrhea were 31.6%, 15.5%, 4.5% 61.2%, and 15.5%, respectively. Children with diarrhea 2 weeks preceding the survey ( = 0.004), children using surface water for domestic purposes ( < 0.001), and those with uneducated mothers ( = 0.001) had increased risk of being stunted and underweight. Children introduced to complementary foods before 6 months of age ( = 0.02) or belonging to polygamous families ( = 0.03) had increased risk of being stunted. Consumption of cow's milk that is not boiled ( = 0.05) or being a boy ( = 0.03) was associated with underweight. Prevalence of undernutrition among under-five children in the population under study was alarming and it could be associated with poor WASH practices and other sociocultural factors. This study underlines the importance of incorporating WASH strategies in formulation of interventions targeting on promotion of nutrition and disease prevention in pastoral communities.
Topics: Agriculture; Child Nutrition Disorders; Child, Preschool; Family Characteristics; Female; Humans; Hygiene; Infant; Male; Sanitation; Tanzania; Water Supply
PubMed: 29532770
DOI: 10.4269/ajtmh.17-0399 -
Therapeutic Advances in Ophthalmology 2023Anthropometry facilitates the evaluation of risks associated with reduced macular pigment optical density (MPOD).
BACKGROUND
Anthropometry facilitates the evaluation of risks associated with reduced macular pigment optical density (MPOD).
OBJECTIVES
To investigate the predictors and anthropometric indices associated with MPOD in healthy adult in Arab population.
DESIGN
This is a cross-sectional study.
METHODS
The MPOD was measured at 0.5° from fovea using a heterochromatic flicker photometer. Healthy participants aged between 20 and 40 years were recruited. The study evaluated the following data of the participants: height, weight, body mass index, body fat percentage, basal metabolic rate, visceral fat level, muscle mass, bone mineral content, and percentage of protein and body water. The correlation between MPOD with anthropometrics and demographic data was evaluated using Spearman's correlation test. The differences among genders were investigated using the Mann-Whitney test. The smoking effect on MPOD was analyzed using the Friedman test.
RESULTS
In all, 143 participants were recruited. The median ± interquartile range was calculated for age (23 ± 4 years), visual acuity (0.00 ± 0.00 logMAR), and MPOD (0.41 ± 0.18). The average MPOD was higher in males than in females but it was not statistically significant ( > 0.05); on the other hand, they were statistically significantly different in most of the anthropometric data. A significant relationship was found between MPOD and percentage of body fat, protein, and body water ( = 0.30, < 0.05). The observed median MPOD value was higher in this study than that found in previous studies in white populations, but lower than that found in studies investigating Asian populations.
CONCLUSION
One of the most important risk factors of age-related macular degeneration is associated with a relative absence of macular pigment. This study brought into focus percentage of protein and body water for further studies as well as the well-established links with body fat and obesity. Unknown predictors of MPOD remain uncovered. The study also provided first report on normative values of MPOD for Arab population and confirmed the differences from other ethnicities.
PubMed: 37599800
DOI: 10.1177/25158414231189099 -
Ultrasonics Sonochemistry Jan 2017In this study, the effects of ultrasound with different ultrasonic frequencies on the properties of sodium alginate (ALG) were investigated, which were characterized by...
In this study, the effects of ultrasound with different ultrasonic frequencies on the properties of sodium alginate (ALG) were investigated, which were characterized by the means of the multi-angle laser light scattering photometer analysis (GPC-MALLS), rheological analysis, circular dichroism (CD) spectrometer and scanning electron microscope (SEM). It showed that the molecular weight (M) and molecular number (M) of the untreated ALG was 1.927×10g/mol and 4.852×10g/mol, respectively. The M of the ultrasound treated ALG was gradually increased from 3.50×10g/mol to 7.34×10g/mol while the M of ALG was increased and then decreased with the increase of the ultrasonic frequency. The maximum value of M was 9.988×10g/mol when the ALG was treated by ultrasound at 40kHz. It indicated that ultrasound could induce ALG degradation and rearrangement. The number of the large molecules and small molecules of ALG was changed by ultrasound. The value of d/d suggested that the ultrasound could enhance the stability of ALG. Furthermore, it was found that ALG treated by ultrasound at 50kHz tended to be closer to a Newtonian behavior, while the untreated and treated ALG solutions exhibited pseudoplastic behaviours. Moreover, CD spectra demonstrated that ultrasound could be used to improve the strength of the gel by changing the ratio of M/G, which showed that the minimum ratio of M/G of ALG treated at 135kHz was 1.34. The gel-forming capacity of ALG was correlated with the content of G-blocks. It suggested that ALG treated by ultrasound at 135kHz was stiffer in the process of forming gels. The morphology results indicated that ultrasound treatment of ALG at 135kHz increased its hydrophobic interaction and interfacial activity. This study is important to explore the effect of ultrasound on ALG in improving the physical properties of ALG as food additives, enzyme and drug carriers.
Topics: Alginates; Glucuronic Acid; Hexuronic Acids; Molecular Weight; Rheology; Ultrasonic Waves
PubMed: 27773287
DOI: 10.1016/j.ultsonch.2016.06.038