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Cureus Aug 2023One of the most important aspects that determines the clinical lifetime of aesthetic restorations, is the color stability (CS) over the long term. This study aims to...
OBJECTIVES
One of the most important aspects that determines the clinical lifetime of aesthetic restorations, is the color stability (CS) over the long term. This study aims to assess the effect of artificial aging and thermocycling in different staining solutions on the CS of bioactive restorative materials compared to conventional ones.
METHODS
The following four material groups were investigated: ACTIVA™ Bioactive (AB) (Pulpdent Corporation, Massachusetts, United States), Beautifil II (BF) (SHOFU Inc., Kyoto, Japan), Fuji II (FJ) (GC Corporation, Tokyo Japan), and Filtek™ Z350 XT (FT) (3M, Minnesota, United States). A total of 100 specimens were fabricated using an acrylic mold and then immersed in five staining solutions groups: coffee, black tea, Cola, mixed berry juice, and saline. Baseline shade (T0) was recorded using two spectro-photometer devices, VITA Easyshade® Advance (VITA Zahnfabrik, Baden-Wurttemberg, Germany) and Color-Eye® 7000A (X-Rite, Inc., Grand Rapids, Michigan, United States). Following this, the shade was recorded at 30 days (T1), three months (T2), and after 5000 thermocycles (5C-55C) (T3). CIE L*a*b* (International Commission on Illumination color space) data was used to calculate ΔE for each group.
RESULTS
All samples showed a significant color change (P<0.001) following one and three months of storage and after thermocycling. AB and BF showed the highest CS over time, whereas FT and FJ showed the least CS.
CONCLUSION
The CS of restorative materials is mostly determined by their type, followed by staining solution type and thermocycling. The most potent solutions were coffee, tea, and berry juice.
PubMed: 37674947
DOI: 10.7759/cureus.43038 -
Environment International Aug 2023This study analyzed the variability of equivalent black carbon (eBC) mass concentrations and their sources in urban Europe to provide insights into the use of eBC as an...
This study analyzed the variability of equivalent black carbon (eBC) mass concentrations and their sources in urban Europe to provide insights into the use of eBC as an advanced air quality (AQ) parameter for AQ standards. This study compiled eBC mass concentration datasets covering the period between 2006 and 2022 from 50 measurement stations, including 23 urban background (UB), 18 traffic (TR), 7 suburban (SUB), and 2 regional background (RB) sites. The results highlighted the need for the harmonization of eBC measurements to allow for direct comparisons between eBC mass concentrations measured across urban Europe. The eBC mass concentrations exhibited a decreasing trend as follows: TR > UB > SUB > RB. Furthermore, a clear decreasing trend in eBC concentrations was observed in the UB sites moving from Southern to Northern Europe. The eBC mass concentrations exhibited significant spatiotemporal heterogeneity, including marked differences in eBC mass concentration and variable contributions of pollution sources to bulk eBC between different cities. Seasonal patterns in eBC concentrations were also evident, with higher winter concentrations observed in a large proportion of cities, especially at UB and SUB sites. The contribution of eBC from fossil fuel combustion, mostly traffic (eBC) was higher than that of residential and commercial sources (eBC) in all European sites studied. Nevertheless, eBC still had a substantial contribution to total eBC mass concentrations at a majority of the sites. eBC trend analysis revealed decreasing trends for eBC over the last decade, while eBC remained relatively constant or even increased slightly in some cities.
Topics: Air Pollutants; Environmental Monitoring; Aerosols; Air Pollution; Europe; Seasons; Soot; Carbon; Particulate Matter
PubMed: 37451041
DOI: 10.1016/j.envint.2023.108081 -
The Journal of Biological Chemistry Sep 1996Chinese hamster ovary cells were stably transfected with a human hepatic lipase (HL) cDNA. The recombinant enzyme was purified from culture medium in milligram...
Chinese hamster ovary cells were stably transfected with a human hepatic lipase (HL) cDNA. The recombinant enzyme was purified from culture medium in milligram quantities and shown to have a molecular weight, specific activity, and heparin affinity equivalent to HL present in human post-heparin plasma. The techniques of intensity light scattering, sedimentation equilibrium, and radiation inactivation were employed to assess the subunit structure of HL. For intensity light scattering, purified enzyme was subjected to size exclusion chromatography coupled to three detectors in series: an ultraviolet absorbance monitor, a differential refractometer, and a light scattering photometer. The polypeptide molecular weight (without carbohydrate contributions) was calculated using the measurements from the three detectors combined with the extinction coefficient of human HL. A single protein peak containing HL activity was identified and calculated to have a molecular mass of 107,000 in excellent agreement with the expected value for a dimer of HL (106.8 kDa). In addition, sedimentation equilibrium studies revealed that HL had a molecular mass (with carbohydrate contributions) of 121 kDa. Finally, to determine the smallest structural unit required for lipolytic activity, HL was subjected to radiation inactivation. Purified HL was exposed to various doses of high energy electrons at -135 degrees C; lipase activity decreased as a single exponential function of the radiation dose to less than 0.01% remaining activity. The target size of functional HL was calculated to be 109 kDa, whereas the size of the structural unit was determined to be 63 kDa. These data indicate that two HL monomer subunits are required for lipolytic activity, consistent with an HL homodimer. A model for active dimeric hepatic lipase is presented with implications for physiological function.
Topics: Animals; Cell Line; Chromatography, Gel; Cricetinae; Cricetulus; Female; Humans; Lipase; Liver; Protein Conformation; Recombinant Proteins; Scattering, Radiation; Transfection; Ultracentrifugation
PubMed: 8798474
DOI: 10.1074/jbc.271.37.22931 -
Evidence-based Complementary and... 2012Rhodomyrtus tomentosa (Myrtaceae) has been employed in traditional Thai medicine to treat colic diarrhoea, dysentery, abscesses, haemorrhage, and gynaecopathy. In...
Rhodomyrtus tomentosa (Myrtaceae) has been employed in traditional Thai medicine to treat colic diarrhoea, dysentery, abscesses, haemorrhage, and gynaecopathy. In addition, it has been used to formulate skin-whitening, anti-aging and skin beautifying agents. Ethnomedical activities of this plant may be due its antioxidant property. Hence, the aim of this study was to evaluate both in vitro and in vivo antioxidant activities of R. tomentosa leaf extract. In vitro antioxidant activity of the extract was assessed by lipid peroxidation inhibition capacity, ferric reducing antioxidant power, and metal chelating activity. R. tomentosa extract demonstrated its free radical scavenging effects in concentration dependent manner. In vivo antioxidant activity of the extract was conducted in Swiss Albino mice. Levels of thio-barbituric acid reactive substances (TBARS), glutathione (GSH), and the activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in blood, liver, and kidney were analyzed using microtitre plate photometer. Administration of CCl(4) caused significant increase in TBARS and decrease in GSH, SOD, CAT and GPx levels. In contrast, R. tomentosa extract (0.8 g/kg) effectively prevented these alterations and maintained the antioxidant status. The results suggest that R. tomentosa extract can serve as a potent antioxidant.
PubMed: 23125869
DOI: 10.1155/2012/535479 -
Frontiers in Microbiology 2021Optical density (OD) measurement is the gold standard to estimate microbial cell density in aqueous systems. Recording microbial growth curves is essential to assess...
Optical density (OD) measurement is the gold standard to estimate microbial cell density in aqueous systems. Recording microbial growth curves is essential to assess substrate utilization, gauge sensitivity to inhibitors or toxins, or determine the perfect sampling point. Manual sampling for cuvette-photometer-based measurements can cause disturbances and impact growth, especially for strictly anaerobic or thermophilic microbes. For slow growing microbes, manual sampling can cause data gaps that complicate analysis. Online OD measurement systems provide a solution, but are often expensive and ill-suited for applications such as monitoring microbial growth in custom or larger anaerobic vessels. Furthermore, growth measurements of thermophilic cultures are limited by the heat sensitivity of complex electronics. Here, we present two simple, low-cost, self-assembled photometers-a "TubeOD" for online measurement of anaerobic and thermophilic cultures in Hungate tubes and a "ClampOD" that can be attached to virtually any transparent growth vessel. Both OD-meters can be calibrated in minutes. We detail the manufacturing and calibration procedure and demonstrate continuous acquisition of high quality cell density data of a variety of microbes, including strict anaerobes, a thermophile, and gas-utilizing strains in various glassware. When calibrated and operated within their detection limits (ca. 0.3-90% of the photosensor voltage range), these self-build OD-meters can be used for continuous measurement of microbial growth in a variety of applications, thereby, simplifying and enhancing everyday lab operations.
PubMed: 35095803
DOI: 10.3389/fmicb.2021.790576 -
American Journal of Ophthalmology Case... Dec 2022To report the efficacy of combination therapy using intravitreal injection of brolucizumab (IVbr) and sub-Tenon's injection of triamcinolone acetonide (STTA) and of...
PURPOSE
To report the efficacy of combination therapy using intravitreal injection of brolucizumab (IVbr) and sub-Tenon's injection of triamcinolone acetonide (STTA) and of monitoring with a laser flare-cell photometer (LFP) in a case of polypoidal choroidal vasculopathy (PCV) with intraocular inflammation (IOI).
OBSERVATIONS
A 72-year-old Japanese woman with PCV had her treatment switched to IVbr due to being refractory to aflibercept. Two weeks after starting IVbr, her visual acuity (VA) declined to 0.40 from 0.10 logarithm of the minimum angle of resolution (logMAR) VA at baseline. In addition, the LFP flare increased to 51.2 photon count/ms (pc/ms) compared with the baseline of 16.1 pc/ms. We diagnosed her with the onset of IOI and immediately started treatment with sub-Tenon's injection of 20 mg triamcinolone acetonide (STTA). Two weeks after receiving STTA, her VA had recovered to 0.15 logMAR, and the LFP flare had decreased to 17.9 pc/ms with dry macula. Eight weeks after the first IVbr treatment, the logMAR VA had improved to -0.18 with achievement of dry macula and stabilization of the LFP flare at 12.2 pc/ms. We administered combined therapy using IVbr and STTA to our patient, and 12 weeks later, the logMAR VA remained at 0.00 with dry macula and 18.1 pc/ms for LFP flare. We continued combination therapy, and after 8 months, her logMAR VA remained at -0.08, and optical coherence tomography showed dry macula, while the LFP flare had stabilized at 16.6 pc/ms.
CONCLUSIONS AND IMPORTANCE
Combination therapy of IVbr and STTA stabilized IOI and achieved dry macula. The LFP flare score clearly showed the degree of and changes in inflammation.
PubMed: 36281264
DOI: 10.1016/j.ajoc.2022.101727 -
Journal of Toxicology and Environmental... Jun 2021This comprehensive review introduces occupational (industrial) hygienists and toxicologists to the seven basic additive manufacturing (AM) process categories. Forty-six...
This comprehensive review introduces occupational (industrial) hygienists and toxicologists to the seven basic additive manufacturing (AM) process categories. Forty-six articles were identified that reported real-world measurements for all AM processes, except sheet lamination. Particles released from powder bed fusion (PBF), material jetting (MJ), material extrusion (ME), and directed energy deposition (DED) processes exhibited nanoscale to submicron scale; real-time particle number (mobility sizers, condensation nuclei counters, miniDiSC, electrical diffusion batteries) and surface area monitors (diffusion chargers) were generally sufficient for these processes. Binder jetting (BJ) machines released particles up to 8.5 µm; optical particle sizers (number) and laser scattering photometers (mass) were sufficient for this process. PBF and DED processes (powdered metallic feedstocks) released particles that contained respiratory irritants (chromium, molybdenum), central nervous system toxicants (manganese), and carcinogens (nickel). All process categories, except those that use metallic feedstocks, released organic gases, including (but not limited to), respiratory irritants (toluene, xylenes), asthmagens (methyl methacrylate, styrene), and carcinogens (benzene, formaldehyde, acetaldehyde). Real-time photoionization detectors for total volatile organics provided useful information for processes that utilize polymer feedstock materials. More research is needed to understand 1) facility-, machine-, and feedstock-related factors that influence emissions and exposures, 2) dermal exposure and biological burden, and 3) task-based exposures. Harmonized emissions monitoring and exposure assessment approaches are needed to facilitate inter-comparison of study results. Improved understanding of AM process emissions and exposures is needed for hygienists to ensure appropriate health and safety conditions for workers and for toxicologists to design experimental protocols that accurately mimic real-world exposure conditions. ABS : acrylonitrile butadiene styrene; ACGIH® TLV® : American Conference of Governmental Industrial Hygienists Threshold Limit Value; ACH : air change per hour; AM : additive manufacturing; ASA : acrylonitrile styrene acrylate; AVP : acetone vapor polishing; BJ : binder jetting; CAM-LEM : computer-aided manufacturing of laminated engineering materials; CNF : carbon nanofiber; CNT : carbon nanotube; CP : co-polyester; CNC : condensation nuclei counter; CVP : chloroform vapor polishing; DED : directed energy deposition; DLP : digital light processing; EBM : electron beam melting; EELS : electron energy loss spectrometry; EDB : electrical diffusion batteries; EDX : energy dispersive x-ray analyzer; ER : emission rate; FDM™ : fused deposition modeling; FFF : fused filament fabrication; IAQ : indoor air quality; LSP : laser scattering photometer; LCD : liquid crystal display; LDSA : lung deposited particle surface area; LOD : limit of detection; LOM : laminated object manufacturing; LOQ : limit of quantitation; MCE : mixed cellulose ester filter; ME : material extrusion; MJ : material jetting; OEL : occupational exposure limit; OPS : optical particle sizer; PBF : powder bed fusion; PBZ : personal breathing zone; PC : polycarbonate; PEEK : poly ether ether ketone; PET : polyethylene terephthalate; PETG : Polyethylene terephthalate glycol; PID : photoionization detector; PLA : polylactic acid; PM : particulate matter with aerodynamic diameter less than 1 µm; PM : particulate matter with aerodynamic diameter less than 2.5 µm; PM : particulate matter with aerodynamic diameter less than 10 µm; PSL : plastic sheet lamination; PVA : polyvinyl alcohol; REL : recommended exposure limit; SDL : selective deposition lamination; SDS : safety data sheet; SEM : scanning electron microscopy; SL : sheet lamination; SLA : stereolithography; SLM : selective laser melting; SMPS : scanning mobility particle sizer; SVOC : semi-volatile organic compound; TEM : transmission electron microscopy; TGA : thermal gravimetric analysis; TPU : thermo polyurethane; UAM : ultrasonic additive manufacturing; UC : ultrasonic consolidation; TVOC : total volatile organic compounds; TWA : time-weighted average; VOC : volatile organic compound; VP : vat photopolymerization.
PubMed: 34139957
DOI: 10.1080/10937404.2021.1936319 -
Journal of Occupational and... Aug 2019The quality of mass concentration estimates from increasingly popular networks of low-cost particulate matter sensors depends on accurate conversion of sensor output...
The quality of mass concentration estimates from increasingly popular networks of low-cost particulate matter sensors depends on accurate conversion of sensor output (e.g., voltage) into gravimetric-equivalent mass concentration, typically using a calibration procedure. This study evaluates two important sources of variability that lead to error in estimating gravimetric-equivalent mass concentration: the temporal changes in sensor calibration and the spatial and temporal variability in gravimetric correction factors. A 40-node sensor network was deployed in a heavy vehicle manufacturing facility for 8 months. At a central location in the facility, particulate matter was continuously measured with three sensors of the network and a traditional, higher-cost photometer, determining the calibration slope and intercept needed to translate sensor output to photometric-equivalent mass concentration. Throughout the facility, during three intensive sampling campaigns, respirable mass concentrations were measured with gravimetric samplers and photometers to determine correction factors needed to adjust photometric-equivalent to gravimetric-equivalent mass concentration. Both field-determined sensor calibration slopes and intercepts were statistically different than those estimated in the laboratory (α = 0.05), emphasizing the importance of aerosol properties when converting voltage to photometric-equivalent mass concentration and the need for field calibration to determine slope. Evidence suggested the sensors' weekly field calibration slope decreased and intercept increased, indicating the sensors were deteriorating over time. The mean correction factor in the cutting and shot blasting area (2.9) was substantially and statistically lower than that in the machining and welding area (4.6; p = 0.01). Therefore, different correction factors should be determined near different occupational processes to accurately estimate particle mass concentrations.
Topics: Air Pollutants; Calibration; Environmental Monitoring; Manufacturing and Industrial Facilities; Motor Vehicles; Occupational Exposure; Particulate Matter
PubMed: 31251121
DOI: 10.1080/15459624.2019.1628965 -
Journal of Oral and Maxillofacial... 2017Oral submucous fibrosis (OSMF), a precancerous condition, is highly prevalent in the Indian subcontinent. Among many trace elements, copper and iron are required for the...
INTRODUCTION
Oral submucous fibrosis (OSMF), a precancerous condition, is highly prevalent in the Indian subcontinent. Among many trace elements, copper and iron are required for the functioning of numerous enzymes. The biochemical alterations of these trace elements in the serum of patients with premalignant conditions can help in determining the staging of the disease, its appropriate treatment and as an indicator for prognosis.
AIMS AND OBJECTIVES
The objective of the study was to evaluate the role of iron and copper as well as to identify the better predictor of the two in the diagnosis and progression of OSMF.
MATERIALS AND METHODS
The study sample consisted of 150 patients, out of which the cases group consisting of 100 OSMF patients and control group consisting of 50 individuals. All the cases were confirmed of having OSMF by histopathological examination. The blood sample was obtained from all 150 patients and evaluated by digital autoanalyzer photometer for serum level of copper and iron by the colorimetric method. The results obtained for cases and controls were compared by statistical analysis.
RESULTS
The mean serum copper level increases while the mean serum iron level decreases with the advancement in the severity of clinical and histological stages of OSMF.
CONCLUSION
Biopsy is the gold standard to diagnose OSMF, but it is an invasive and time-consuming technique. However, nowadays, many recent advances are used to diagnose OSMF at an early stage and reduce its progression into late and reversible stages. The trace elements serve as potential prognostic and diagnostic markers for OSMF patients.
PubMed: 29391727
DOI: 10.4103/jomfp.JOMFP_106_14 -
African Journal of Laboratory Medicine 2023Haemolysis - one of the major limiting factors of red cell concentrate quality - must be measured as a quality-monitoring requirement. According to international quality...
BACKGROUND
Haemolysis - one of the major limiting factors of red cell concentrate quality - must be measured as a quality-monitoring requirement. According to international quality standards, percentage haemolysis must be monitored in 1.0% of red cell concentrates produced monthly and maintained under 0.8%.
OBJECTIVE
This study assessed three alternative methods for determining plasma haemoglobin concentration in peripheral blood banks that lack a plasma or low haemoglobin photometer - the gold-standard method - in Sri Lanka.
METHODS
A standard haemolysate was prepared using an unexpired whole blood pack of normal haemoglobin concentration. A concentration series from 0.1 g/dL to 1.0 g/dL was prepared by diluting portions of standard haemolysate with saline. The alternative methods, namely visual haemoglobin colour scale, spectrophotometric calibration graph, and standard haemolysate capillary tube comparison, were designed using this concentration series and were used to test red cell concentrates received at the Quality Control Department of the National Blood Center, Sri Lanka, from February 2021 to May 2021.
RESULTS
A strong correlation was observed between the haemoglobin photometer method and the alternative methods ( = ~0.9). Based on the linear regression model, the standard haemolysate capillary tube comparison method was the best of the three alternative methods ( = 0.974).
CONCLUSION
All three alternative methods are recommended for use in peripheral blood banks. The standard haemolysate capillary tube comparison method was the best model.
PubMed: 36873291
DOI: 10.4102/ajlm.v12i1.1987