AIM:To determine the agreement of ocular biometric indices including axial length,keratometric readings,anterior chamber depth,and horizontal corneal diameter between the Pentacam AXL and IOL Master 500.METHODS:The st...AIM:To determine the agreement of ocular biometric indices including axial length,keratometric readings,anterior chamber depth,and horizontal corneal diameter between the Pentacam AXL and IOL Master 500.METHODS:The study was a large cross-sectional population-based study(Tehran Geriatric Eye Study)conducted from Jan 2019 to Jan 2020.A total of 160 clusters were randomly selected proportional to size(each cluster contained 20 individuals)from 22 strata of Tehran city.All people aged 60y and above were invited to participate in the study.For all participants,preliminary ocular examinations were performed including the measurement of uncorrected and best-corrected visual acuity,objective and subjective refraction,anterior and posterior segment examinations.All participants underwent an ocular biometry using the Pentacam AXL and IOL Master 500.RESULTS:The 95%limits of agreement(LoA)between the two devices were-0.13 to 0.19,-0.15 to 0.17,and-0.13 to 0.19 in normal,pseudophakic,and cataractous eyes,respectively.With increasing the axial length,the difference between the two devices significantly increased in all three groups of normal,pseudophakic,and cataractous eyes(P<0.001).The 95% LoAs between the two devices regarding the mean keratometry shows that the best LoAs were seen in cataractous(-0.33 to 0.81)and followed by normal eyes(-0.36 to 0.86)and the pseudophakic eyes(-0.48 to 0.90)had the widest LoA.The 95% LoAs for horizontal corneal diameter measurements were-0.08 to 0.86,-0.03 to 0.83,and-0.07 to 0.87 in normal,pseudophakic,and cataractous eyes,respectively.The 95% LoAs of anterior chamber depth measurements between the two devices was-0.39 to 0.19 and-0.37 to 0.13 in normal eyes and cataractous,respectively.CONCLUSION:The Pentacam AXL has excellent agreement with the gold standard,IOL Master 500 in measuring axial length.In eyes with cataracts,the difference between the two devices is more scattered.With the increasing of axial length,the difference between the two devices increased,which should be considered when using Pentacam AXL.展开更多
Background:Cataract surgery is the most common surgical procedure in ophthalmology.Biometry data and accurate intraocular lens(IOL)calculations are very important in achieving the desired refractive outcomes.The aim o...Background:Cataract surgery is the most common surgical procedure in ophthalmology.Biometry data and accurate intraocular lens(IOL)calculations are very important in achieving the desired refractive outcomes.The aim of this study was to compare measurements using a new optical low coherence reflectometry(OLCR)biometer(OA-2000)and the gold standard partial coherence interferometry(PCI)optical biometer(IOLMaster 500).Methods:Ocular biometry of cataract patients were measured by the OA-2000 and IOLMaster 500 to compare keratometry(K),axial length(AL),anterior chamber depth(ACD),white-to-white(WTW)diameter,and IOL power using the SRK/T formula.Results:One hundred and two eyes of 68 cataract patients were evaluated with the two optical biometers.The mean values of the AL,K,ACD,and WTW differed very little(OCLR biometer,23.12 mm,44.50 diopters(D),3.06,and 11.64 mm,respectively;PCI biometer,23.18 mm,44.6 D,3.15,and 11.86 mm,respectively),but the differences were significant(all,p≤0.05).The AL,K,and ACD showed excellent correlations(r=0.999,0.980,and 0.824,respectively;all p<0.001);however,there was a weak correlation of the WTW diameter between the two devices(r=0.256).The IOL powers using the SRK-T formula derived from both instruments were very similar,with an excellent correlation(r=0.989).The mean difference between the two instruments was 0.32 D.Conclusions:The OLCR biometer showed very a strong agreement with the standard PCI optical biometer for almost all ocular biometry measurements,except for the WTW diameter.Trial registration:TCTR20160614003;date 06/09/2016;‘retrospectively registered’.展开更多
Recent progress in bioinorganic chemistry studies of rare earth elements (REE) in animal cells was outlined, and the definition of REE′s biological intelligence as well as their mechanism were also explained. The mig...Recent progress in bioinorganic chemistry studies of rare earth elements (REE) in animal cells was outlined, and the definition of REE′s biological intelligence as well as their mechanism were also explained. The migration of REE from weathering rocks to the environment is accelerated by various anthropogenic activities, which can eventually result in the entrance of REE into animal and human bodies via food chain. REE can be found in body tissues such as brain, blood, muscle as well as bone. Based on their geochemical properties, REE in low dose show their unique biological intelligence by intervening in the process of signal transduction and its regulation, arteriosclerosis and blood clotting prevention, anticancer, and the promotion of cellular defense enzymes′ activities, nucleic acid metabolism enzymes as well as ATPases, etc. The meaning of REE′s biological intelligence refers to physicochemical properties-based capability to choose the targets (e.g., biometals) in biomolecules for the chelation or replacement of REE, and change the structures and functions of biomolecules, and consequently impact or control the biological functions or behaviors in living organisms. The regulation of various cellular processes caused by REE is mainly via antagonism or replacement of essential target biometals like calcium or via chelation of organic molecules, thereby embodying the unparalleled biological intelligence of REE. Additionally, the dosage effect of REE was also discussed from the angles of yin-yang dichotomy, bioavailability, entropy and evolution. In order to make full use of REE′s biological intelligence in the application for medicine, more detailed studies concerning dosage effect of REE and REE bioaccumulation in organisms should be conducted in future research.展开更多
Iron and its alloys are attractive as biodegradable materials because of their low toxicity and suitable mechanical properties;however,they generally have a slow degradation rate.Given that corrosion is an electrochem...Iron and its alloys are attractive as biodegradable materials because of their low toxicity and suitable mechanical properties;however,they generally have a slow degradation rate.Given that corrosion is an electrochemical phenomenon where an exchange of electrons takes place,the application of magnetic fields from outside the body may accelerate the degradation of a ferrous temporary implant.In the present study,we have investigated the effect of alternating and direct low magnetic field(H=6.5 kA/m)on the corrosion process of pure iron(Fe)and an iron-manganese alloy(FeMnC)in modified Hanks’solution.A 14-day static immersion test was performed on the materials.The corrosion rate was assessed by mass and cross-sectional loss measurements,scanning electron microscopy,X-ray diffractometry,Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy before and after degradation.The results show that the presence of magnetic fields significantly accelerates the degradation rate of both materials,with the corrosion rate being twice as high in the case of Fe and almost three times as high for FeMnC.In addition,a homogenous degradation layer is formed over the entire surface and the chemical composition of the degradation products is the same regardless of the presence of a magnetic field.展开更多
基金Supported by the Deputy of Research and Technology of Tehran University of Medical Sciences as a PhD Thesis.
文摘AIM:To determine the agreement of ocular biometric indices including axial length,keratometric readings,anterior chamber depth,and horizontal corneal diameter between the Pentacam AXL and IOL Master 500.METHODS:The study was a large cross-sectional population-based study(Tehran Geriatric Eye Study)conducted from Jan 2019 to Jan 2020.A total of 160 clusters were randomly selected proportional to size(each cluster contained 20 individuals)from 22 strata of Tehran city.All people aged 60y and above were invited to participate in the study.For all participants,preliminary ocular examinations were performed including the measurement of uncorrected and best-corrected visual acuity,objective and subjective refraction,anterior and posterior segment examinations.All participants underwent an ocular biometry using the Pentacam AXL and IOL Master 500.RESULTS:The 95%limits of agreement(LoA)between the two devices were-0.13 to 0.19,-0.15 to 0.17,and-0.13 to 0.19 in normal,pseudophakic,and cataractous eyes,respectively.With increasing the axial length,the difference between the two devices significantly increased in all three groups of normal,pseudophakic,and cataractous eyes(P<0.001).The 95% LoAs between the two devices regarding the mean keratometry shows that the best LoAs were seen in cataractous(-0.33 to 0.81)and followed by normal eyes(-0.36 to 0.86)and the pseudophakic eyes(-0.48 to 0.90)had the widest LoA.The 95% LoAs for horizontal corneal diameter measurements were-0.08 to 0.86,-0.03 to 0.83,and-0.07 to 0.87 in normal,pseudophakic,and cataractous eyes,respectively.The 95% LoAs of anterior chamber depth measurements between the two devices was-0.39 to 0.19 and-0.37 to 0.13 in normal eyes and cataractous,respectively.CONCLUSION:The Pentacam AXL has excellent agreement with the gold standard,IOL Master 500 in measuring axial length.In eyes with cataracts,the difference between the two devices is more scattered.With the increasing of axial length,the difference between the two devices increased,which should be considered when using Pentacam AXL.
文摘Background:Cataract surgery is the most common surgical procedure in ophthalmology.Biometry data and accurate intraocular lens(IOL)calculations are very important in achieving the desired refractive outcomes.The aim of this study was to compare measurements using a new optical low coherence reflectometry(OLCR)biometer(OA-2000)and the gold standard partial coherence interferometry(PCI)optical biometer(IOLMaster 500).Methods:Ocular biometry of cataract patients were measured by the OA-2000 and IOLMaster 500 to compare keratometry(K),axial length(AL),anterior chamber depth(ACD),white-to-white(WTW)diameter,and IOL power using the SRK/T formula.Results:One hundred and two eyes of 68 cataract patients were evaluated with the two optical biometers.The mean values of the AL,K,ACD,and WTW differed very little(OCLR biometer,23.12 mm,44.50 diopters(D),3.06,and 11.64 mm,respectively;PCI biometer,23.18 mm,44.6 D,3.15,and 11.86 mm,respectively),but the differences were significant(all,p≤0.05).The AL,K,and ACD showed excellent correlations(r=0.999,0.980,and 0.824,respectively;all p<0.001);however,there was a weak correlation of the WTW diameter between the two devices(r=0.256).The IOL powers using the SRK-T formula derived from both instruments were very similar,with an excellent correlation(r=0.989).The mean difference between the two instruments was 0.32 D.Conclusions:The OLCR biometer showed very a strong agreement with the standard PCI optical biometer for almost all ocular biometry measurements,except for the WTW diameter.Trial registration:TCTR20160614003;date 06/09/2016;‘retrospectively registered’.
文摘Recent progress in bioinorganic chemistry studies of rare earth elements (REE) in animal cells was outlined, and the definition of REE′s biological intelligence as well as their mechanism were also explained. The migration of REE from weathering rocks to the environment is accelerated by various anthropogenic activities, which can eventually result in the entrance of REE into animal and human bodies via food chain. REE can be found in body tissues such as brain, blood, muscle as well as bone. Based on their geochemical properties, REE in low dose show their unique biological intelligence by intervening in the process of signal transduction and its regulation, arteriosclerosis and blood clotting prevention, anticancer, and the promotion of cellular defense enzymes′ activities, nucleic acid metabolism enzymes as well as ATPases, etc. The meaning of REE′s biological intelligence refers to physicochemical properties-based capability to choose the targets (e.g., biometals) in biomolecules for the chelation or replacement of REE, and change the structures and functions of biomolecules, and consequently impact or control the biological functions or behaviors in living organisms. The regulation of various cellular processes caused by REE is mainly via antagonism or replacement of essential target biometals like calcium or via chelation of organic molecules, thereby embodying the unparalleled biological intelligence of REE. Additionally, the dosage effect of REE was also discussed from the angles of yin-yang dichotomy, bioavailability, entropy and evolution. In order to make full use of REE′s biological intelligence in the application for medicine, more detailed studies concerning dosage effect of REE and REE bioaccumulation in organisms should be conducted in future research.
基金Financial support of Ministry of Science and Innovation of Spain(MICINN)PID2021-123891OB-I00.PID2021-124341OB-C21 and PID2022-139323NB-I00 funded by MCIN/AEI/10.13039/501100011033Rey Juan Carlos University,M′ostoles(Madrid)Spain has funded the C1PREDOC2020 grant of Irene Lim′onsupported by the Natural Science and Engineering Research Council of Canada,the Fonds de la Recherche du Qu′ebec sur les Natures et les Technologies,and the Canada Foundation for Innovation.
文摘Iron and its alloys are attractive as biodegradable materials because of their low toxicity and suitable mechanical properties;however,they generally have a slow degradation rate.Given that corrosion is an electrochemical phenomenon where an exchange of electrons takes place,the application of magnetic fields from outside the body may accelerate the degradation of a ferrous temporary implant.In the present study,we have investigated the effect of alternating and direct low magnetic field(H=6.5 kA/m)on the corrosion process of pure iron(Fe)and an iron-manganese alloy(FeMnC)in modified Hanks’solution.A 14-day static immersion test was performed on the materials.The corrosion rate was assessed by mass and cross-sectional loss measurements,scanning electron microscopy,X-ray diffractometry,Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy before and after degradation.The results show that the presence of magnetic fields significantly accelerates the degradation rate of both materials,with the corrosion rate being twice as high in the case of Fe and almost three times as high for FeMnC.In addition,a homogenous degradation layer is formed over the entire surface and the chemical composition of the degradation products is the same regardless of the presence of a magnetic field.
