AIM:To compare the 12-month outcomes of visual performance and patient satisfaction of a higherorder aspheric monofocal intraocular lens(IOL)and a conventional monofocal IOL.METHODS:Prospective,randomized,comparative,...AIM:To compare the 12-month outcomes of visual performance and patient satisfaction of a higherorder aspheric monofocal intraocular lens(IOL)and a conventional monofocal IOL.METHODS:Prospective,randomized,comparative,double-blinded study including 22 patients who underwent bilateral cataract surgery with implantation of the Tecnis Eyhance ICB00 IOL in one eye(ICB00 group)and the Tecnis ZCB00 IOL in the fellow eye(ZCB00 group).Uncorrected distance(UDVA),corrected distance(CDVA),uncorrected intermediate(UIVA),distance-corrected intermediate(DCIVA),uncorrected near(UNVA),and distance-corrected near visual acuities(DCNVA)were evaluated during a 12-month follow-up.Contrast sensitivity,defocus curves,and reading text size were also evaluated.Patient satisfaction was assessed with a questionnaire at the 6-month postoperative visit.RESULTS:Mean postoperative logMAR UDVA was 0.01±0.12 and-0.02±0.10 in ICB00 and ZCB00 groups,respectively(P=0.37).Mean logMAR UIVA was 0.32±0.19 and 0.45±0.16 in ICB00 and ZCB00 groups,respectively(P=0.010).Differences between groups in UNVA did not reach statistical significance(P=0.16).The intermediate reading acuity at 66 cm(P=0.02)and 80 cm(P=0.04)was significantly better in the ICB00 group.Postoperative contrast sensitivity results did not differ significantly between groups(P>0.05).Patients reported high overall satisfaction,with 62%of patients using spectacles for reading in everyday life.CONCLUSION:The eyes of patients implanted with the enhanced monofocal IOL evaluated have significantly better visual acuity for intermediate distances with the same contrast sensitivity as a conventional monofocal IOL.展开更多
AIM:To assess whether the implantation of a posterior chamber phakic intraocular lens produces changes in optical coherence tomography(OCT)measurements of macular thickness(MT)and two parameters that define the struct...AIM:To assess whether the implantation of a posterior chamber phakic intraocular lens produces changes in optical coherence tomography(OCT)measurements of macular thickness(MT)and two parameters that define the structure of the optic nerve,the peripapillary nerve fiber layer(RNFL)and the Bruch’s membrane opening-minimum rim width(BMO-MRW).METHODS:This nonrandomized prospective pre-post study included 86 eyes of 48 patients(age,20-47y;axial length:23.10-28.95 mm)scheduled for myopia or myopic astigmatism correction with implantation of the implantable collamer lens(ICL).Eyes with glaucoma or any other ocular disease that could alter OCT results were excluded.RNFL,BMO-MRW and MT were measured preoperatively,and at 1 and 6mo after surgery using spectral-domain OCT.Changes between preoperative and postoperative values were evaluated.RESULTS:There was a significant increase in BMOMRW at 1mo(mean change:3.48±15.07μm,P=0.041).No significant changes were found during the rest of followup(1-6mo postop.,P=0.623).There was also a significant increase in RNFL thickness at 1mo af ter surger y(1.45±2.18μm,P<0.001),but with a significant reduction from 1 to 6mo postoperatively(P=0.002).Regarding MT,it increased significantly at 1mo(2.46±3.76μm,P<0.001),with a significant decrease afterwards(P=0.048).Measurements of the three parameters at 6mo were slightly superior to preoperative values(P<0.01).CONCLUSION:Minimal changes are induced in BMOMRW,RNFL and MT after ICL implantation in healthy eyes,confirming the safety of the surgical procedure regarding the structure of the optic nerve head and the macula,and indicating that this phakic intraocular lens seems to have a slight impact on OCT measurements.展开更多
AIM： To determine the presence of symptomatic accommodative and non-strabismic binocular dysfunctions （A.sBD） in a non-presbyopic population of video display unit （VDU） users with flat-panel displays. METHODS： ...AIM： To determine the presence of symptomatic accommodative and non-strabismic binocular dysfunctions （A.sBD） in a non-presbyopic population of video display unit （VDU） users with flat-panel displays. METHODS： One hundred and one VDU users, aged between 20 to 34y, initially participated in the study. This study excluded contact-lens wearers and subjects who had undergone refractive surgery or had any systemic or ocular disease. First, subjects were asked about the type and nature of eye symptoms they experienced during VDU use. Then, a thorough eye examination excluded those subjects with a significant uncorrected refractive error or other problem, such as ocular motility disorders, vertical deviation, strabismus and eye diseases. Finally, the remaining participants underwent an exhaustive assessment of their accommodative and binocular vision status. RESULTS： Eighty-nine VDU users （46 females and 43 males） were included in this study. They used flat-panel displays for an average of 5±1.9h a day. Twenty subjects presented A.sBD （22.5%）. Convergence excess was the most frequent non-strabismic binocular dysfunction （9 subjects）, followed by fusional vergence dysfunction （3 subjects） and convergence insufficiency （2 subjects）. Within the accommodative dysfunctions, accommodative excess was the most common （4 subjects）, followed by accommodative insufficiency （2 subjects）. Moderate to severe eye symptoms were found in 13 subjects with ANSBD. CONCLUSION： Significant eye symptoms in VDU users with accommodative and/or non-strabismic binocular dysfunctions often occur and should not be underestimated; therefore, an appropriate evaluation of accommodative and binocular vision status is more important for this population,展开更多
AIM:To evaluate the accuracy of spherical equivalent(SE) estimates of a double-pass system and to compare it with retinoscopy,subjective refraction and a table mounted autorefractor.METHODS:Non-cycloplegic refraction ...AIM:To evaluate the accuracy of spherical equivalent(SE) estimates of a double-pass system and to compare it with retinoscopy,subjective refraction and a table mounted autorefractor.METHODS:Non-cycloplegic refraction was performed on 125 eyes of 65 healthy adults(age 23.5±3.0 years) from October 2010 to January 2011 using retinoscopy,subjective refraction,autorefraction(Auto kerato refractometer TOPCON KR-8100,Japan) and a double pass system(Optical Quality Analysis System,OQAS,Visiometrics S.L.,Spain).Nine consecutive measurements with the double-pass system were performed on a subgroup of 22 eyes to assess repeatability.To evaluate the trueness of the OQAS instrument,the SE laboratory bias between the double pass system and the other techniques was calculated.RESULTS:The SE mean coefficient of repeatability obtained was 0.22D.Significant correlations could be established between the OQAS and the SE obtained with retinoscopy(r=0.956,P【0.001),subjective refraction(r=0.955,P【0.001) and autorefraction(r=0.957,P【0.001).The differences in SE between the double-pass system and the other techniques were significant(P【0.001),but lacked clinical relevance except for retinoscopy;Retinoscopy gave more hyperopic values than the double-pass system-0.51±0.50D as well as the subjective refraction-0.23±0.50D;More myopic values were achieved by means of autorefraction 0.24±0.49D. CONCLUSION:The double-pass system provides accurate and reliable estimates of the SE that can be used for clinical studies.This technique can determine the correct focus position to assess the ocular optical quality.However,it has a relatively small measuring range in comparison with autorefractors(-8.00 to +5.00D),and requires prior information on the refractive state of the patient.展开更多
AIM:To evaluate and compare the efficacy of the astigmatic correction achieved with laser in situ keratomileusis(LASIK)in eyes with myopic astigmatism using wavefront-guided(WFG)and wavefront-optimized(WFO)ablation pr...AIM:To evaluate and compare the efficacy of the astigmatic correction achieved with laser in situ keratomileusis(LASIK)in eyes with myopic astigmatism using wavefront-guided(WFG)and wavefront-optimized(WFO)ablation profiles.METHODS:Prospective study included 221 eyes undergoing LASIK:99 and 122 eyes with low and moderate myopic astigmatism(low and moderate myopia groups).Two subgroups were differentiated in each group according to the ablation profile:WFG subgroup,109 eyes(45/64,low/moderate myopia groups)treated using the Advanced Custom Vue platform(Abbott Medical Optics Inc.),and WFO subgroup,112 eyes(54/58,low/moderate myopia groups)treated using the EX-500 platform(Alcon).Clinical outcomes were evaluated during a 6-month follow-up,including a vector analysis of astigmatic changes.RESULTS:Significantly better postoperative uncorrected visual acuity and efficacy index was found in the WFG subgroups of each group(P≤0.041).Postoperative spherical equivalent and cylinder were significantly higher in WFO subgroups(P≤0.003).In moderate myopia group,a higher percentage of eyes with a postoperative cylinder≤0.25 D was found in the WFG subgroup(90.6%vs 65.5%,P=0.002).In low and moderate myopia groups,the difference vector was significantly higher in the WFO subgroup compared to WFG(P〈0.001).In moderate myopia group,the magnitude(P=0.008)and angle of error(P〈0.001)were also significantly higher in the WFO subgroup.Significantlyless induction of high order aberrations were found with WFG treatments in both low and moderate myopia groups(P≤0.006).CONCLUSION:A more efficacious correction of myopic astigmatism providing a better visual outcome is achieved with WFG LASIK compared to WFO LASIK.展开更多
Spectroscopic properties of flashlamp pumped Nd^3＋：YAG laser are studied as a function of temperature in a range from-30℃ to 60℃. The spectral width and shift of quasi three-level 946.0-nm inter-Stark emission wit...Spectroscopic properties of flashlamp pumped Nd^3＋：YAG laser are studied as a function of temperature in a range from-30℃ to 60℃. The spectral width and shift of quasi three-level 946.0-nm inter-Stark emission within the respective intermanifold transitions of ^4F3/2→^4I9/2are investigated. The 946.0-nm line shifts toward the shorter wavelength and broadens. In addition, the threshold power and slope efficiency of the 946.0-nm laser line are quantified with temperature.The lower the temperature, the lower the threshold power is and the higher the slope efficiency of the 946.0-nm laser line is,thus the higher the laser output is. This phenomenon is attributed to the ion-phonon interaction and the thermal population in the ground state.展开更多
Multifocal intraocular lenses(IOLs) are currently usually implanted for the treatment of cataracts because they have been proved to be superior to monofocal IOLs with respect to spectacle independence. In turn, they a...Multifocal intraocular lenses(IOLs) are currently usually implanted for the treatment of cataracts because they have been proved to be superior to monofocal IOLs with respect to spectacle independence. In turn, they are associated with a higher prevalence of dysphotopsia symptoms that is one of the most common causes of patient dissatisfaction. Neuroadaptation seems to play a major role in the optimal adaptation to multifocal IOLs. In this context, the development of strategies that facilitate the neuroadaptation process to multifocality might be an effective strategy to reduce patients' dissatisfaction. Video games have been proved to be effective for the improvement of visual acuity and for the promotion of neuroplasticity in elderly subjects and other populations with cortical-related visual impairment. This narrative review highlights the physiological potential of video games as a perceptual strategy to improve visual acuity and promote neuroplasticity in patients using multifocalIOLs, although research is still needed to confirm these benefits in this specific population, with only one comparative study to this date providing evidence of them.展开更多
AIM： To evaluate the prevalence of eye symptoms in a non-presbyopic population of video display unit （VDU） users with flat-panel displays. METHODS： One hundred and sixteen VDU users with flat-panel display from an...AIM： To evaluate the prevalence of eye symptoms in a non-presbyopic population of video display unit （VDU） users with flat-panel displays. METHODS： One hundred and sixteen VDU users with flat-panel display from an urban population participated in the study; their ages ranging from 20 to 34y. There were 60 females and 56 males. An eye examination to rule out the presence of significant uncorrected refractive errors, general binocular dysfunctions and eye conditions was carried out. In order to determine and quantify the type and nature of eye symptoms, participants were asked to answer written questionnaire and the results were grouped by gender, age and number of hours a day spent using a VDU. RESULTS： Seventy-two percent of participants reported eye symptoms related to VDU use. Eye symptoms from moderate-to-severe were found in 23% of participants. The main symptom was moderate-to- severe tired eyes （14%）; followed by sensitivity to bright lights （12%）, blurred vision at far distances （10%）, eyestrain or dry eye or irritated or burning eyes （9%）, difficulty in refocusing from one distance to another or headache （8%） and blurred vision at near or intermediate distances （〈4%）. Eye symptoms were greater among females （P=0.005） and increased with VDU use, markedly above 6h spent using a VDU in a typical day （P=0.01）. CONCLUSION： Significant eye symptoms relate to VDU use often occur and should not be underestimated. The increasing use of electronic devices with flat-panel display should prompt users to take appropriate measures to prevent or to relieve the eye symptoms arising from their use.展开更多
The optical limiting properties of the mixed liquid of carbon black suspensions （CBS） and green tea solution were studied by using an 8 ns laser pulse at 532 nm. The optical limiting effects of the CBS and mixed liq...The optical limiting properties of the mixed liquid of carbon black suspensions （CBS） and green tea solution were studied by using an 8 ns laser pulse at 532 nm. The optical limiting effects of the CBS and mixed liquid have been compared between 5 and 10 Hz repetition frequencies with nanosecond laser pulse. The experimental results indicate that the optical limiting threshold of the sample with the incidence laser at 10 Hz repetition frequency is lower than at 5 Hz repetition frequency. The possible reasons for the influence of the repetition frequency on the samples are discussed. And by observing the optical radiant distributions when the laser pulse passing through different samples, a possible mechanism for the observed effects is suggested. At the same time, the result shows that the optical limiting of CBS is the dominant factor to optical limiting of the mixed liquid.展开更多
A multiple-image encryption method based on two-step phase-shifting interferometry （PSI） and spatial multiplexing of a smooth compressed signal is proposed. In the encoding and encryption process, with the help of f...A multiple-image encryption method based on two-step phase-shifting interferometry （PSI） and spatial multiplexing of a smooth compressed signal is proposed. In the encoding and encryption process, with the help of four index matrices to store original pixel positions, all the pixels of four secret images are firstly reordered in an ascending order; then, the four reordered images are transformed by five-order Haar wavelet transform and performed sparseness operation. After Arnold transform and pixels sampling operation, one combined image can be grouped with the aid of compressive sensing （CS） and spatial multiplexing techniques. Finally, putting the combined image at the input plane of the PSI encryption scheme, only two interferograms ciphertexts can be obtained. During the decoding and decryption, utilizing all the secret key groups and index matrices keys, all the original secret images can be successfully decrypted by a wave-front retrieval algorithm of two-step PSI, spatial de-multiplexing, inverse Arnold transform, inverse discrete wavelet transform, and pixels reordering operation.展开更多
AIM: To evaluate the interchangeability of keratometric and asphericity measurements provided by three measurement systems based on different optical principles.METHODS: A total of 40 eyes of 40 patients with a mean a...AIM: To evaluate the interchangeability of keratometric and asphericity measurements provided by three measurement systems based on different optical principles.METHODS: A total of 40 eyes of 40 patients with a mean age of 34.1 y were included. In all cases, a corneal curvature analysis was performed with IOL-Master(IOLM), iDesign 2(ID2), and Sirius systems(SIR). Differences between instruments for flattest(K1) and steepest(K2) keratometric readings, as well as for magnitude and axis of corneal astigmatism were analyzed. Likewise, differences in asphericity(Q) between SIR and ID2 were also evaluated. RESULTS: Mean differences between devices for K1 were 0.20±0.21(P<0.001),-0.12±0.36(P=0.046) and-0.32±0.36 D(P<0.001) for the comparisons IOLM-SIR, IOLM-ID2 and SIR-ID2, respectively. The ranges of agreement for these comparisons between instruments were 0.41, 0.70, and 0.70 D. For K2, mean differences were 0.31±0.33(P<0.001),-0.08±0.43(P=0.265) and-0.39±0.38 D(P<0.001), with ranges of agreement of 0.65, 0.84, and 0.74 D. Concerning magnitude of astigmatism, ranges of agreement were in the limit of clinical relevance(0.49 D, P=0.011; 0.55 D, P=0.386; 0.43 D, P=0.05). In contrast, ranges of agreement were clinically relevant for astigmatic axis(26.68o, 33.83o and 18.37o, P≥0.121) and for Q between SIR and ID2(0.16, P<0.001). CONCLUSION: The keratometric corneal power, astigmatic axis and asphericity measurements provideby the three systems evaluated cannot be considered as interchangeable, whereas measurements of corneal astigmatism obtained with SIR and ID2 can be considered as interchangeable for clinical purposes.展开更多
Lead halide perovskites have attracted considerable attention as potential candidates for high-performance nano/microlasers,owing to their outstanding optical properties.However,the further development of perovskite m...Lead halide perovskites have attracted considerable attention as potential candidates for high-performance nano/microlasers,owing to their outstanding optical properties.However,the further development of perovskite microlaser arrays(especially based on polycrystalline thin films)produced by the conventional processing techniques is hindered by the chemical instability and surface roughness of the perovskite structures.Herein,we demonstrate a laser patterning of large-scale,highly crystalline perovskite single-crystal films to fabricate reproducible perovskite single-crystal-based microlaser arrays.Perovskite thin films were directly ablated by femtosecond-laser in multiple low-power cycles at a minimum machining line width of approximately 300 nm to realize high-precision,chemically clean,and repeatable fabrication of microdisk arrays.The surface impurities generated during the process can be washed away to avoid external optical loss due to the robustness of the single-crystal film.Moreover,the high-quality,large-sized perovskite single-crystal films can significantly improve the quality of microcavities,thereby realizing a perovskite microdisk laser with narrow linewidth(0.09 nm)and low threshold(5.1µJ/cm2).Benefiting from the novel laser patterning method and the large-sized perovskite single-crystal films,a high power and high color purity laser display with single-mode microlasers as pixels was successfully fabricated.Thus,this study may offer a potential platform for mass-scale and reproducible fabrication of microlaser arrays,and further facilitate the development of highly integrated applications based on perovskite materials.展开更多
This paper reports that the nonlinear refractive index of a novel organic optical storage film doped azodiphenylamine polymer is measured by using the Z-scan technique. The nonlinear refractive index up to 3.7× 1...This paper reports that the nonlinear refractive index of a novel organic optical storage film doped azodiphenylamine polymer is measured by using the Z-scan technique. The nonlinear refractive index up to 3.7× 10^-6 cm^2/W induced by thermo-optical effect is obtained. It indicates that the sample has excellent optical non- linear properties. The physical mechanism of the great nonlinear optical effect is analysed and the optical conjugate characteristic is also discussed with degenerate four-wave-mixing. The phase conjugate wave diffracted from the formative refractive index grating in the sample is acquired and its equivalent reflectivity reaches about 22%. On this basis, the reflective wave phase-conjugated mirror system was designed, and the image aberration experienced in propagation in the storage experiment is corrected by using the system.展开更多
This paper presents the anisotropic optical feedback of a single frequency intra-cavity He-Ne laser. A novel phenomenon was discovered that the laser output an elliptical polarized frequency instead of the initial lin...This paper presents the anisotropic optical feedback of a single frequency intra-cavity He-Ne laser. A novel phenomenon was discovered that the laser output an elliptical polarized frequency instead of the initial linear polarized one. Two intensities with a phase difference were detected, both of which were modulated in the form of cosine wave and a fringe shift corresponds to a λ/2 movement of the feedback mirror. The phase difference can be continuously modulated by the wave plate in the external cavity. Frequency stabilization was used to stabilize the laser frequency so as to enlarge the measuring range and improve the measurement precision. This anisotropic optical feedback system offers a potential displacement measurement technology with the function of subdivision of λ/2 and in-time direction judgment. The three-mirror Fabry Perot cavity model is used to present the experimental results. Given the lack of need of lasing adjustment, this full intra-cavity laser can significantly improve the simplicity and stability of the optical feedback system.展开更多
We report the optical response characteristics of A1/Ti bilayer transition edge sensors （TESs）, which are mainly comprised of A1/Ti bilayer thermometers and suspended SiN membranes for thermal isolation. The measure...We report the optical response characteristics of A1/Ti bilayer transition edge sensors （TESs）, which are mainly comprised of A1/Ti bilayer thermometers and suspended SiN membranes for thermal isolation. The measurement was performed in a 3He sorption refrigerator and the device＇s response to optical pulses was investigated using a pulsed laser source. Based on these measurements, we obtained the effective recovery time （τeff） of the devices at different biases and discussed the dependence of Veff on the bias. The device with a 940 μm × 940 μm continuous suspended SiN membrane demonstrated a fast response speed with τeff = 3.9 μs, which indicates a high temperature sensitivity （a = T/R·dR/dT = 326）. The results also showed that the TES exhibits good linearity under optical pulses of variable widths.展开更多
Background:Athletes tend to have better visuo-motor performance than do sedentary individuals.However,several basic visual-function and perceptual parameters remain unexplored to date.In this study,we investigated whe...Background:Athletes tend to have better visuo-motor performance than do sedentary individuals.However,several basic visual-function and perceptual parameters remain unexplored to date.In this study,we investigated whether differences exist in visual function,performance,and processing between basketball players and individuals without a sport-involvement background.Methods:A total of 33 healthy men with no visual impairment or pathology were divided into 2 groups,depending on the involvement in sport(semi-professional basketball players and sedentary individuals).We tested their baseline heart-rate variability in the resting position apart from subjective questionnaires to determine their physical fitness level,and we checked their visual function,performance,and processing through an extended battery of optometric tests.Results:The 2 groups differed in resting heart-rate variability parameters(p<0.001),confirming their dissimilarities in regular time practising sports per week.The basketball players showed a closer breakpoint and recovery nearpoint of convergence,a higher fusional-vergence rate,better discriminability halos,and better eye-hand coordination(all p values<0.05).Conclusion:These results show evidence that athletes,basketball players in this case,exhibit better performance in several visual abilities in comparison to a group of individuals without sporting backgrounds,suggesting an improvement due to the systematic involvement of those skills during basketball practice.展开更多
A novel dmit^2- salt： （tetramethylammonium）bis（1,3-dithiole-2-thione-4,5-dithiolato） copper, abbreviated as MECu, is synthesized and its third-order optical nonlinearity is characterized by Z-scan technique at a ...A novel dmit^2- salt： （tetramethylammonium）bis（1,3-dithiole-2-thione-4,5-dithiolato） copper, abbreviated as MECu, is synthesized and its third-order optical nonlinearity is characterized by Z-scan technique at a wavelength of 1064nm with laser duration of 30ps. Z-scan curves reveal a negative Kerr coefficient at 1064nm and no nonlinear absorption is observed. The nonlinear refraction coefficient n2 and the second hyperpolarizability γ have been determined to be as large as 2.15 × 10^-11 esu and 3.23 × 10^-31 esu, respectively, suggesting MECu is a potential material for optical device applications.展开更多
AIM:To simulate and compare accommodation in accommodative and non-accommodative human eye models.METHODS:Ray tracing and optical design program was used.Three eye models were designed and studied:the Navarro,the Ariz...AIM:To simulate and compare accommodation in accommodative and non-accommodative human eye models.METHODS:Ray tracing and optical design program was used.Three eye models were designed and studied:the Navarro,the Arizona and the Liou-Brennan.In order to make the Navarro and Liou-Brennan models to accommodate,specific geometric parameters of the models were altered with values that were chosen from the literature.For the Arizona model,its’mathematical functions for accommodation were used for the same accommodative demands.The simulation included four distances of accommodation for each model:at infinity,3,1 and 0.5 m.The results were diffraction images of a“letter F”for graphical comparison,spot diagrams on the retinal field and Modulation Transfer Function(MTF)graphs.RESULTS:Zernike coefficients for the aberrations,Airy disk diameter,root mean square(RMS)error diameter and total axial length of the model were provided from the program.These were compared between them in all distances.The Navarro model had the smallest axial length change as a simple model.The Arizona did not change its axial length because it is designed to be accommodative.The Liou-Brennan model had different results concerning the aberrations because of the decentration of the pupil.The MTF graphs showed small differences between the models because of the differences in their designs.CONCLUSION:All the three models are able to simulate accommodation with the expected results.There is no model that can be assumed as the best choice.Accommodation can be simulated in non-accommodativemodels and in customized ones.展开更多
The complex and mostly multiple and unknown aetiology of neurodegenerative diseases always give way to an intricate scenario of dying tissue that involves multiple cell mediators and cell types.All neurodegenerative d...The complex and mostly multiple and unknown aetiology of neurodegenerative diseases always give way to an intricate scenario of dying tissue that involves multiple cell mediators and cell types.All neurodegenerative diseases of the central nervous system(CNS)share common mechanisms,regardless their origin:oxidative stress,neuroinflammation and cell death.Accordingly,retinal degenerative diseases,with or without a genetic cause,as retinitis pigmentosa(RP),glaucoma,agerelated macular degeneration(AMD)or diabetic retinopathy(DR)do not differ in their basic mechanisms of cell death neither one to another,nor from those observed in other CNS diseases as Parkinson’s or Alzheimer’s(Cuenca et al.,2014).Indeed,the therapeutic findings should be able to be more or less easily extrapolated between these conditions,as far as they are directed to common dartboards.展开更多
The third-order optical nonlinearities of [（CH3）4N]Au（dmit）2 （dmit = 4,5-dithiolate-1,3-dithiole-2-thione） at 532 nm and 1064 nm are investigated using the Z-scan technique with pulses of picoseconds duration. T...The third-order optical nonlinearities of [（CH3）4N]Au（dmit）2 （dmit = 4,5-dithiolate-1,3-dithiole-2-thione） at 532 nm and 1064 nm are investigated using the Z-scan technique with pulses of picoseconds duration. The Z-scan spectra reveal a strong nonlinear absorption （reverse saturable absorption） and a negative nonlinear refraction at 532 nm. No nonlinear absorption is observed at 1064 nm. The molecular second-order hyperpolarizability γ for the [（CH3）4N]Au（dmit）2 molecule at 532nm is estimated to be as high as （2.1 ±0.1） × 10^-31 esu, which is nearly three times larger than that at 1064 nm. The mechanism responsible for the difference between the results is analysed. Nonlinear transmission measurements suggest that this material has potential applications in optical limiting.展开更多
文摘AIM:To compare the 12-month outcomes of visual performance and patient satisfaction of a higherorder aspheric monofocal intraocular lens(IOL)and a conventional monofocal IOL.METHODS:Prospective,randomized,comparative,double-blinded study including 22 patients who underwent bilateral cataract surgery with implantation of the Tecnis Eyhance ICB00 IOL in one eye(ICB00 group)and the Tecnis ZCB00 IOL in the fellow eye(ZCB00 group).Uncorrected distance(UDVA),corrected distance(CDVA),uncorrected intermediate(UIVA),distance-corrected intermediate(DCIVA),uncorrected near(UNVA),and distance-corrected near visual acuities(DCNVA)were evaluated during a 12-month follow-up.Contrast sensitivity,defocus curves,and reading text size were also evaluated.Patient satisfaction was assessed with a questionnaire at the 6-month postoperative visit.RESULTS:Mean postoperative logMAR UDVA was 0.01±0.12 and-0.02±0.10 in ICB00 and ZCB00 groups,respectively(P=0.37).Mean logMAR UIVA was 0.32±0.19 and 0.45±0.16 in ICB00 and ZCB00 groups,respectively(P=0.010).Differences between groups in UNVA did not reach statistical significance(P=0.16).The intermediate reading acuity at 66 cm(P=0.02)and 80 cm(P=0.04)was significantly better in the ICB00 group.Postoperative contrast sensitivity results did not differ significantly between groups(P>0.05).Patients reported high overall satisfaction,with 62%of patients using spectacles for reading in everyday life.CONCLUSION:The eyes of patients implanted with the enhanced monofocal IOL evaluated have significantly better visual acuity for intermediate distances with the same contrast sensitivity as a conventional monofocal IOL.
文摘AIM:To assess whether the implantation of a posterior chamber phakic intraocular lens produces changes in optical coherence tomography(OCT)measurements of macular thickness(MT)and two parameters that define the structure of the optic nerve,the peripapillary nerve fiber layer(RNFL)and the Bruch’s membrane opening-minimum rim width(BMO-MRW).METHODS:This nonrandomized prospective pre-post study included 86 eyes of 48 patients(age,20-47y;axial length:23.10-28.95 mm)scheduled for myopia or myopic astigmatism correction with implantation of the implantable collamer lens(ICL).Eyes with glaucoma or any other ocular disease that could alter OCT results were excluded.RNFL,BMO-MRW and MT were measured preoperatively,and at 1 and 6mo after surgery using spectral-domain OCT.Changes between preoperative and postoperative values were evaluated.RESULTS:There was a significant increase in BMOMRW at 1mo(mean change:3.48±15.07μm,P=0.041).No significant changes were found during the rest of followup(1-6mo postop.,P=0.623).There was also a significant increase in RNFL thickness at 1mo af ter surger y(1.45±2.18μm,P<0.001),but with a significant reduction from 1 to 6mo postoperatively(P=0.002).Regarding MT,it increased significantly at 1mo(2.46±3.76μm,P<0.001),with a significant decrease afterwards(P=0.048).Measurements of the three parameters at 6mo were slightly superior to preoperative values(P<0.01).CONCLUSION:Minimal changes are induced in BMOMRW,RNFL and MT after ICL implantation in healthy eyes,confirming the safety of the surgical procedure regarding the structure of the optic nerve head and the macula,and indicating that this phakic intraocular lens seems to have a slight impact on OCT measurements.
文摘AIM： To determine the presence of symptomatic accommodative and non-strabismic binocular dysfunctions （A.sBD） in a non-presbyopic population of video display unit （VDU） users with flat-panel displays. METHODS： One hundred and one VDU users, aged between 20 to 34y, initially participated in the study. This study excluded contact-lens wearers and subjects who had undergone refractive surgery or had any systemic or ocular disease. First, subjects were asked about the type and nature of eye symptoms they experienced during VDU use. Then, a thorough eye examination excluded those subjects with a significant uncorrected refractive error or other problem, such as ocular motility disorders, vertical deviation, strabismus and eye diseases. Finally, the remaining participants underwent an exhaustive assessment of their accommodative and binocular vision status. RESULTS： Eighty-nine VDU users （46 females and 43 males） were included in this study. They used flat-panel displays for an average of 5±1.9h a day. Twenty subjects presented A.sBD （22.5%）. Convergence excess was the most frequent non-strabismic binocular dysfunction （9 subjects）, followed by fusional vergence dysfunction （3 subjects） and convergence insufficiency （2 subjects）. Within the accommodative dysfunctions, accommodative excess was the most common （4 subjects）, followed by accommodative insufficiency （2 subjects）. Moderate to severe eye symptoms were found in 13 subjects with ANSBD. CONCLUSION： Significant eye symptoms in VDU users with accommodative and/or non-strabismic binocular dysfunctions often occur and should not be underestimated; therefore, an appropriate evaluation of accommodative and binocular vision status is more important for this population,
基金Spanish Ministry of Education and Science(No.DPI2008-06455-C02-01)European Union and the Spanish Agency for International Cooperation(AECI)(No.D/030286/10)
文摘AIM:To evaluate the accuracy of spherical equivalent(SE) estimates of a double-pass system and to compare it with retinoscopy,subjective refraction and a table mounted autorefractor.METHODS:Non-cycloplegic refraction was performed on 125 eyes of 65 healthy adults(age 23.5±3.0 years) from October 2010 to January 2011 using retinoscopy,subjective refraction,autorefraction(Auto kerato refractometer TOPCON KR-8100,Japan) and a double pass system(Optical Quality Analysis System,OQAS,Visiometrics S.L.,Spain).Nine consecutive measurements with the double-pass system were performed on a subgroup of 22 eyes to assess repeatability.To evaluate the trueness of the OQAS instrument,the SE laboratory bias between the double pass system and the other techniques was calculated.RESULTS:The SE mean coefficient of repeatability obtained was 0.22D.Significant correlations could be established between the OQAS and the SE obtained with retinoscopy(r=0.956,P【0.001),subjective refraction(r=0.955,P【0.001) and autorefraction(r=0.957,P【0.001).The differences in SE between the double-pass system and the other techniques were significant(P【0.001),but lacked clinical relevance except for retinoscopy;Retinoscopy gave more hyperopic values than the double-pass system-0.51±0.50D as well as the subjective refraction-0.23±0.50D;More myopic values were achieved by means of autorefraction 0.24±0.49D. CONCLUSION:The double-pass system provides accurate and reliable estimates of the SE that can be used for clinical studies.This technique can determine the correct focus position to assess the ocular optical quality.However,it has a relatively small measuring range in comparison with autorefractors(-8.00 to +5.00D),and requires prior information on the refractive state of the patient.
基金Partially supported by a grant from Abbott Medical Optics
文摘AIM:To evaluate and compare the efficacy of the astigmatic correction achieved with laser in situ keratomileusis(LASIK)in eyes with myopic astigmatism using wavefront-guided(WFG)and wavefront-optimized(WFO)ablation profiles.METHODS:Prospective study included 221 eyes undergoing LASIK:99 and 122 eyes with low and moderate myopic astigmatism(low and moderate myopia groups).Two subgroups were differentiated in each group according to the ablation profile:WFG subgroup,109 eyes(45/64,low/moderate myopia groups)treated using the Advanced Custom Vue platform(Abbott Medical Optics Inc.),and WFO subgroup,112 eyes(54/58,low/moderate myopia groups)treated using the EX-500 platform(Alcon).Clinical outcomes were evaluated during a 6-month follow-up,including a vector analysis of astigmatic changes.RESULTS:Significantly better postoperative uncorrected visual acuity and efficacy index was found in the WFG subgroups of each group(P≤0.041).Postoperative spherical equivalent and cylinder were significantly higher in WFO subgroups(P≤0.003).In moderate myopia group,a higher percentage of eyes with a postoperative cylinder≤0.25 D was found in the WFG subgroup(90.6%vs 65.5%,P=0.002).In low and moderate myopia groups,the difference vector was significantly higher in the WFO subgroup compared to WFG(P〈0.001).In moderate myopia group,the magnitude(P=0.008)and angle of error(P〈0.001)were also significantly higher in the WFO subgroup.Significantlyless induction of high order aberrations were found with WFG treatments in both low and moderate myopia groups(P≤0.006).CONCLUSION:A more efficacious correction of myopic astigmatism providing a better visual outcome is achieved with WFG LASIK compared to WFO LASIK.
基金Project supported by Estahban Branch,Islamic Azad University
文摘Spectroscopic properties of flashlamp pumped Nd^3＋：YAG laser are studied as a function of temperature in a range from-30℃ to 60℃. The spectral width and shift of quasi three-level 946.0-nm inter-Stark emission within the respective intermanifold transitions of ^4F3/2→^4I9/2are investigated. The 946.0-nm line shifts toward the shorter wavelength and broadens. In addition, the threshold power and slope efficiency of the 946.0-nm laser line are quantified with temperature.The lower the temperature, the lower the threshold power is and the higher the slope efficiency of the 946.0-nm laser line is,thus the higher the laser output is. This phenomenon is attributed to the ion-phonon interaction and the thermal population in the ground state.
基金Coco-Martin MB,Maldonado-López MJ,Molina-Martín A and Pi?ero DP are supported by CDTI(Centro para el Desarrollo Tecnológico Industrial,Ministry of Economy and Competitiveness of Spain)by means of the program PID(“Proyectos de Investigación y Desarrollo”)The author Pi?ero DP has been also supported by the Ministry of Economy,Industry and Competitiveness of Spain within the program Ramón y Cajal(RYC-2016-20471)Valenzuela PL is supported by a contract granted by University of Alcalá(FPI2016)
文摘Multifocal intraocular lenses(IOLs) are currently usually implanted for the treatment of cataracts because they have been proved to be superior to monofocal IOLs with respect to spectacle independence. In turn, they are associated with a higher prevalence of dysphotopsia symptoms that is one of the most common causes of patient dissatisfaction. Neuroadaptation seems to play a major role in the optimal adaptation to multifocal IOLs. In this context, the development of strategies that facilitate the neuroadaptation process to multifocality might be an effective strategy to reduce patients' dissatisfaction. Video games have been proved to be effective for the improvement of visual acuity and for the promotion of neuroplasticity in elderly subjects and other populations with cortical-related visual impairment. This narrative review highlights the physiological potential of video games as a perceptual strategy to improve visual acuity and promote neuroplasticity in patients using multifocalIOLs, although research is still needed to confirm these benefits in this specific population, with only one comparative study to this date providing evidence of them.
文摘AIM： To evaluate the prevalence of eye symptoms in a non-presbyopic population of video display unit （VDU） users with flat-panel displays. METHODS： One hundred and sixteen VDU users with flat-panel display from an urban population participated in the study; their ages ranging from 20 to 34y. There were 60 females and 56 males. An eye examination to rule out the presence of significant uncorrected refractive errors, general binocular dysfunctions and eye conditions was carried out. In order to determine and quantify the type and nature of eye symptoms, participants were asked to answer written questionnaire and the results were grouped by gender, age and number of hours a day spent using a VDU. RESULTS： Seventy-two percent of participants reported eye symptoms related to VDU use. Eye symptoms from moderate-to-severe were found in 23% of participants. The main symptom was moderate-to- severe tired eyes （14%）; followed by sensitivity to bright lights （12%）, blurred vision at far distances （10%）, eyestrain or dry eye or irritated or burning eyes （9%）, difficulty in refocusing from one distance to another or headache （8%） and blurred vision at near or intermediate distances （〈4%）. Eye symptoms were greater among females （P=0.005） and increased with VDU use, markedly above 6h spent using a VDU in a typical day （P=0.01）. CONCLUSION： Significant eye symptoms relate to VDU use often occur and should not be underestimated. The increasing use of electronic devices with flat-panel display should prompt users to take appropriate measures to prevent or to relieve the eye symptoms arising from their use.
基金supported by the National Science Foundation for Post-doctoral Scientists of China (Grant No 20060400418)the Key Scientific Research Foundation of the Ordnance Engineering College,China (Grant No YJJXM05002)
文摘The optical limiting properties of the mixed liquid of carbon black suspensions （CBS） and green tea solution were studied by using an 8 ns laser pulse at 532 nm. The optical limiting effects of the CBS and mixed liquid have been compared between 5 and 10 Hz repetition frequencies with nanosecond laser pulse. The experimental results indicate that the optical limiting threshold of the sample with the incidence laser at 10 Hz repetition frequency is lower than at 5 Hz repetition frequency. The possible reasons for the influence of the repetition frequency on the samples are discussed. And by observing the optical radiant distributions when the laser pulse passing through different samples, a possible mechanism for the observed effects is suggested. At the same time, the result shows that the optical limiting of CBS is the dominant factor to optical limiting of the mixed liquid.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61775121,61307003,61405122,and 11574311)Key R&D Program of Shandong Province,China(Grant No.2018GGX101002)+1 种基金the Natural Science Foundation of Shandong Province,China(Grant No.R2016FM03)the Fundamental Research Funds of Shandong University,China(Grant No.2015GN031)
文摘A multiple-image encryption method based on two-step phase-shifting interferometry （PSI） and spatial multiplexing of a smooth compressed signal is proposed. In the encoding and encryption process, with the help of four index matrices to store original pixel positions, all the pixels of four secret images are firstly reordered in an ascending order; then, the four reordered images are transformed by five-order Haar wavelet transform and performed sparseness operation. After Arnold transform and pixels sampling operation, one combined image can be grouped with the aid of compressive sensing （CS） and spatial multiplexing techniques. Finally, putting the combined image at the input plane of the PSI encryption scheme, only two interferograms ciphertexts can be obtained. During the decoding and decryption, utilizing all the secret key groups and index matrices keys, all the original secret images can be successfully decrypted by a wave-front retrieval algorithm of two-step PSI, spatial de-multiplexing, inverse Arnold transform, inverse discrete wavelet transform, and pixels reordering operation.
基金supported by the Ministry of Economy,Industry and Competitiveness of Spain within the program Ramón y Cajal,RYC-2016-20471Additionally he received an unrestricted grant from Johnson and Johnson Vision for the performance of this research
文摘AIM: To evaluate the interchangeability of keratometric and asphericity measurements provided by three measurement systems based on different optical principles.METHODS: A total of 40 eyes of 40 patients with a mean age of 34.1 y were included. In all cases, a corneal curvature analysis was performed with IOL-Master(IOLM), iDesign 2(ID2), and Sirius systems(SIR). Differences between instruments for flattest(K1) and steepest(K2) keratometric readings, as well as for magnitude and axis of corneal astigmatism were analyzed. Likewise, differences in asphericity(Q) between SIR and ID2 were also evaluated. RESULTS: Mean differences between devices for K1 were 0.20±0.21(P<0.001),-0.12±0.36(P=0.046) and-0.32±0.36 D(P<0.001) for the comparisons IOLM-SIR, IOLM-ID2 and SIR-ID2, respectively. The ranges of agreement for these comparisons between instruments were 0.41, 0.70, and 0.70 D. For K2, mean differences were 0.31±0.33(P<0.001),-0.08±0.43(P=0.265) and-0.39±0.38 D(P<0.001), with ranges of agreement of 0.65, 0.84, and 0.74 D. Concerning magnitude of astigmatism, ranges of agreement were in the limit of clinical relevance(0.49 D, P=0.011; 0.55 D, P=0.386; 0.43 D, P=0.05). In contrast, ranges of agreement were clinically relevant for astigmatic axis(26.68o, 33.83o and 18.37o, P≥0.121) and for Q between SIR and ID2(0.16, P<0.001). CONCLUSION: The keratometric corneal power, astigmatic axis and asphericity measurements provideby the three systems evaluated cannot be considered as interchangeable, whereas measurements of corneal astigmatism obtained with SIR and ID2 can be considered as interchangeable for clinical purposes.
基金the support from the National Natural Science Foundation of China (No. 61925506)the Natural Science Foundation of Shanghai (No. 20JC1414605)+1 种基金Hangzhou Science and Technology Bureau of Zhejiang Province (No. TD2020002)the Academic/Technology Research Leader Program of Shanghai (23XD1404500)
文摘Lead halide perovskites have attracted considerable attention as potential candidates for high-performance nano/microlasers,owing to their outstanding optical properties.However,the further development of perovskite microlaser arrays(especially based on polycrystalline thin films)produced by the conventional processing techniques is hindered by the chemical instability and surface roughness of the perovskite structures.Herein,we demonstrate a laser patterning of large-scale,highly crystalline perovskite single-crystal films to fabricate reproducible perovskite single-crystal-based microlaser arrays.Perovskite thin films were directly ablated by femtosecond-laser in multiple low-power cycles at a minimum machining line width of approximately 300 nm to realize high-precision,chemically clean,and repeatable fabrication of microdisk arrays.The surface impurities generated during the process can be washed away to avoid external optical loss due to the robustness of the single-crystal film.Moreover,the high-quality,large-sized perovskite single-crystal films can significantly improve the quality of microcavities,thereby realizing a perovskite microdisk laser with narrow linewidth(0.09 nm)and low threshold(5.1µJ/cm2).Benefiting from the novel laser patterning method and the large-sized perovskite single-crystal films,a high power and high color purity laser display with single-mode microlasers as pixels was successfully fabricated.Thus,this study may offer a potential platform for mass-scale and reproducible fabrication of microlaser arrays,and further facilitate the development of highly integrated applications based on perovskite materials.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 19834030 and 50533010）.
文摘This paper reports that the nonlinear refractive index of a novel organic optical storage film doped azodiphenylamine polymer is measured by using the Z-scan technique. The nonlinear refractive index up to 3.7× 10^-6 cm^2/W induced by thermo-optical effect is obtained. It indicates that the sample has excellent optical non- linear properties. The physical mechanism of the great nonlinear optical effect is analysed and the optical conjugate characteristic is also discussed with degenerate four-wave-mixing. The phase conjugate wave diffracted from the formative refractive index grating in the sample is acquired and its equivalent reflectivity reaches about 22%. On this basis, the reflective wave phase-conjugated mirror system was designed, and the image aberration experienced in propagation in the storage experiment is corrected by using the system.
基金supported by the National Natural Science Foundation of China (Grant No 60437010)
文摘This paper presents the anisotropic optical feedback of a single frequency intra-cavity He-Ne laser. A novel phenomenon was discovered that the laser output an elliptical polarized frequency instead of the initial linear polarized one. Two intensities with a phase difference were detected, both of which were modulated in the form of cosine wave and a fringe shift corresponds to a λ/2 movement of the feedback mirror. The phase difference can be continuously modulated by the wave plate in the external cavity. Frequency stabilization was used to stabilize the laser frequency so as to enlarge the measuring range and improve the measurement precision. This anisotropic optical feedback system offers a potential displacement measurement technology with the function of subdivision of λ/2 and in-time direction judgment. The three-mirror Fabry Perot cavity model is used to present the experimental results. Given the lack of need of lasing adjustment, this full intra-cavity laser can significantly improve the simplicity and stability of the optical feedback system.
基金supported by the National Basic Research Program of China(Grant No.2011CBA00304)Tsinghua University Initiative Scientific Research Program,China(Grant No.20131089314)the National Natural Science Foundation of China(Grant Nos.60836001 and 11273023)
文摘We report the optical response characteristics of A1/Ti bilayer transition edge sensors （TESs）, which are mainly comprised of A1/Ti bilayer thermometers and suspended SiN membranes for thermal isolation. The measurement was performed in a 3He sorption refrigerator and the device＇s response to optical pulses was investigated using a pulsed laser source. Based on these measurements, we obtained the effective recovery time （τeff） of the devices at different biases and discussed the dependence of Veff on the bias. The device with a 940 μm × 940 μm continuous suspended SiN membrane demonstrated a fast response speed with τeff = 3.9 μs, which indicates a high temperature sensitivity （a = T/R·dR/dT = 326）. The results also showed that the TES exhibits good linearity under optical pulses of variable widths.
文摘Background:Athletes tend to have better visuo-motor performance than do sedentary individuals.However,several basic visual-function and perceptual parameters remain unexplored to date.In this study,we investigated whether differences exist in visual function,performance,and processing between basketball players and individuals without a sport-involvement background.Methods:A total of 33 healthy men with no visual impairment or pathology were divided into 2 groups,depending on the involvement in sport(semi-professional basketball players and sedentary individuals).We tested their baseline heart-rate variability in the resting position apart from subjective questionnaires to determine their physical fitness level,and we checked their visual function,performance,and processing through an extended battery of optometric tests.Results:The 2 groups differed in resting heart-rate variability parameters(p<0.001),confirming their dissimilarities in regular time practising sports per week.The basketball players showed a closer breakpoint and recovery nearpoint of convergence,a higher fusional-vergence rate,better discriminability halos,and better eye-hand coordination(all p values<0.05).Conclusion:These results show evidence that athletes,basketball players in this case,exhibit better performance in several visual abilities in comparison to a group of individuals without sporting backgrounds,suggesting an improvement due to the systematic involvement of those skills during basketball practice.
基金Supported by the National Natural Science Foundation under Grant No 60377016 and 60476020, and the National High Technology Development Program of China under Grant No 2002AA313070.
文摘A novel dmit^2- salt： （tetramethylammonium）bis（1,3-dithiole-2-thione-4,5-dithiolato） copper, abbreviated as MECu, is synthesized and its third-order optical nonlinearity is characterized by Z-scan technique at a wavelength of 1064nm with laser duration of 30ps. Z-scan curves reveal a negative Kerr coefficient at 1064nm and no nonlinear absorption is observed. The nonlinear refraction coefficient n2 and the second hyperpolarizability γ have been determined to be as large as 2.15 × 10^-11 esu and 3.23 × 10^-31 esu, respectively, suggesting MECu is a potential material for optical device applications.
基金Supported by the Marie Curie Grant FP7-LIFEITN-2013-608049-AGEYE
文摘AIM:To simulate and compare accommodation in accommodative and non-accommodative human eye models.METHODS:Ray tracing and optical design program was used.Three eye models were designed and studied:the Navarro,the Arizona and the Liou-Brennan.In order to make the Navarro and Liou-Brennan models to accommodate,specific geometric parameters of the models were altered with values that were chosen from the literature.For the Arizona model,its’mathematical functions for accommodation were used for the same accommodative demands.The simulation included four distances of accommodation for each model:at infinity,3,1 and 0.5 m.The results were diffraction images of a“letter F”for graphical comparison,spot diagrams on the retinal field and Modulation Transfer Function(MTF)graphs.RESULTS:Zernike coefficients for the aberrations,Airy disk diameter,root mean square(RMS)error diameter and total axial length of the model were provided from the program.These were compared between them in all distances.The Navarro model had the smallest axial length change as a simple model.The Arizona did not change its axial length because it is designed to be accommodative.The Liou-Brennan model had different results concerning the aberrations because of the decentration of the pupil.The MTF graphs showed small differences between the models because of the differences in their designs.CONCLUSION:All the three models are able to simulate accommodation with the expected results.There is no model that can be assumed as the best choice.Accommodation can be simulated in non-accommodativemodels and in customized ones.
基金supported by Ministerio de Ciencia e innovación FEDER-PID2019-106230RB-I00.Instituto Carlos III,RETICS-FEDER RD16/0008/0016Retina Asturias/Cantabria.FARPE-FUNDALUCE.Generalitat Valenciana IDIFEDER/2017/064(to NC)。
文摘The complex and mostly multiple and unknown aetiology of neurodegenerative diseases always give way to an intricate scenario of dying tissue that involves multiple cell mediators and cell types.All neurodegenerative diseases of the central nervous system(CNS)share common mechanisms,regardless their origin:oxidative stress,neuroinflammation and cell death.Accordingly,retinal degenerative diseases,with or without a genetic cause,as retinitis pigmentosa(RP),glaucoma,agerelated macular degeneration(AMD)or diabetic retinopathy(DR)do not differ in their basic mechanisms of cell death neither one to another,nor from those observed in other CNS diseases as Parkinson’s or Alzheimer’s(Cuenca et al.,2014).Indeed,the therapeutic findings should be able to be more or less easily extrapolated between these conditions,as far as they are directed to common dartboards.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 60377016 and 60476020） and the National High Technology Development Program of China （Grant No 2002AA313070）.
文摘The third-order optical nonlinearities of [（CH3）4N]Au（dmit）2 （dmit = 4,5-dithiolate-1,3-dithiole-2-thione） at 532 nm and 1064 nm are investigated using the Z-scan technique with pulses of picoseconds duration. The Z-scan spectra reveal a strong nonlinear absorption （reverse saturable absorption） and a negative nonlinear refraction at 532 nm. No nonlinear absorption is observed at 1064 nm. The molecular second-order hyperpolarizability γ for the [（CH3）4N]Au（dmit）2 molecule at 532nm is estimated to be as high as （2.1 ±0.1） × 10^-31 esu, which is nearly three times larger than that at 1064 nm. The mechanism responsible for the difference between the results is analysed. Nonlinear transmission measurements suggest that this material has potential applications in optical limiting.
