We report on the impact of direct ultraviolet germicidal irradiation（UVGI）on reflective optics,used in the excimer laser system Allegretto Eye-Q.The aim of our work was to confirm our hypothesis based on long-rate o...We report on the impact of direct ultraviolet germicidal irradiation（UVGI）on reflective optics,used in the excimer laser system Allegretto Eye-Q.The aim of our work was to confirm our hypothesis based on long-rate observations of obtained anomalies in post-operative results that are attributed to degradation of reflective optics upon ultraviolet radiation.The presence of direct UVGI coupled with humidity in the operating environment caused merging anomalies and unwanted post-operative correction values.Ultraviolet-A radiation caused a similar effect on the reflective cover of the mirrors.展开更多
Ge self-assembled quantum dots （SAQDs） are grown with a self-assembled UHV/CVD epitaxy system. Then, the as-grown Ge quantum dots are annealed by ArF excimer laser. In the ultra-shot laser pulse duration, -20ns, bul...Ge self-assembled quantum dots （SAQDs） are grown with a self-assembled UHV/CVD epitaxy system. Then, the as-grown Ge quantum dots are annealed by ArF excimer laser. In the ultra-shot laser pulse duration, -20ns, bulk diffusion is forbidden,and only surface diffusion occurs, resulting in a laser induced quantum dot （LIQD）. The diameter of the LIQD is 20-25nm which is much smaller than the as-grown dot and the LIQD has a higher density of about 6 ×10^10cm^-2. The surface morphology evolution is investigated by AFM.展开更多
Ablation experiments of A950 Liquid Crystal Polymer (LCP), as a kind of typical matrix of fibre reinforced polymer composites, are carried out in this paper. Data on the ablation of A950 LCP by excimer laser at 24...Ablation experiments of A950 Liquid Crystal Polymer (LCP), as a kind of typical matrix of fibre reinforced polymer composites, are carried out in this paper. Data on the ablation of A950 LCP by excimer laser at 248 nm are presented. The experimental results show that the ablation depth is a linear function of the number of pulse at constant laser fluence, The ablation rate varies with the logorithm of the fluence in a linear manner at different fluences. A satisfactory linear relationship is found between ablation energy and incident fluence. Perhaps due to the plume absorption and thermal effect, the ablation rate varies complicatedly with pulse repetition frequency.展开更多
In this study,a KrF excimer laser was used to modify the biodegradable Mg-1Ca alloy and the time-evolution degradation behavior of the alloy before and after laser treatment was investigated in simulated body fluid(SB...In this study,a KrF excimer laser was used to modify the biodegradable Mg-1Ca alloy and the time-evolution degradation behavior of the alloy before and after laser treatment was investigated in simulated body fluid(SBF)solution using immersion tests and electrochemical impedance spectroscopy(EIS).A 5μm melted layer with a homogeneous microstructure and an MgO film on the surface were achieved by laser radiation.Corrosion observations(hydrogen evolution,morphology and corrosion products)and EIS results revealed an improvement of corrosion resistance after laser treatment for 48 h.It was found a two-layer structure developed after 2 h immersion on both the untreated and laser-treated alloys,but the sequence of forming the two layers was opposite and greatly influenced by the laser-treated layer.The time-evolution corrosion processes on the untreated and laser-treated alloys were discussed,providing a better understanding of corrosion behavior of biodegradable Mg alloys modified by excimer laser.展开更多
AIM:To investigate the size of functional optical zone(FOZ)after small incision lenticule extraction(SMILE)versus femtosecond laser assisted excimer laser keratomileusis(FS-LASIK)for myopia correction and potential as...AIM:To investigate the size of functional optical zone(FOZ)after small incision lenticule extraction(SMILE)versus femtosecond laser assisted excimer laser keratomileusis(FS-LASIK)for myopia correction and potential associated factors for FOZ.METHODS:A total of 133 patients who received corneal refractive surgery in our hospital between November 2018 and July 2021 were retrospectively enrolled.There were 63 patients(123 eyes)in SMILE group and 70patients(139 eyes)in FS-LASIK group.The size of FOZ was measured using Pentacam 3-dementional anterior segment analyzer before and 3mo after surgery,so as to analyze postoperative achieved functional optical zone(AFOZ)and its contributing parameters.RESULTS:When planned functional optical zone(PFOZ)was 6.5 mm for both groups,AFOZ was 1.45±0.27 and 1.67±0.25 mm smaller than preoperative FOZ in SMILE group and FS-LASIK group 3mo after surgery.AFOZ in SMILE group was significantly larger than that in FS-LASIK group(P<0.001).Variation of FOZ was negatively correlated with preoperative spherical equivalent(SE)and positively correlated with variation of mean keratometry value(△Km),variation of spherical aberration(△SA),and variation of Q-value(△Q,all P<0.001)in both groups.Multiple variable linear regression equations were△FOZ=1.354-0.1×pre-SE+0.336×△Q+1.462×△SA in SMILE group and△FOZ=1.512+0.137×△Q+0.468×△SA in FS-LASIK group.CONCLUSION:AFOZ is significantly smaller than preoperative FOZ in both SMILE and FS-LASIK groups.With the same PFOZ,larger AFOZ is achieved in SMILE group than in FS-LASIK group.展开更多
BACKGROUND Percutaneous coronary intervention can be challenging for ostial coronary artery lesions due to calcium burden and elastic fiber content.Excimer laser coronary atherectomy(ELCA)is a less common treatment fo...BACKGROUND Percutaneous coronary intervention can be challenging for ostial coronary artery lesions due to calcium burden and elastic fiber content.Excimer laser coronary atherectomy(ELCA)is a less common treatment for severe calcified coronary ostium lesions.CASE SUMMARY An 81-year-old male presented to the Cardiology Department of Qingdao Municipal Hospital with a 1-year history of chest pain.Coronary angiography showed severe calcific stenosis(approximately 90%)in the right coronary artery ostium.The right coronary artery ostium was unable to be advanced using a 2.5 mm×12.0 mm balloon(NC Sprinter,Medtronic,United States)or dilated using a 2.0 mm×12.0 mm balloon(Sprinter,Medtronic,United States).The patient underwent successful ELCA and balloon dilation of the calcified coronary ostium lesion.CONCLUSION ELCA appears to be a safe and effective treatment for the management of severe calcified coronary ostium lesions.展开更多
Polycrystalline silicon （poly-Si） thin film has been prepared by means of nickel-disilicide （NiSi2） assisted excimer laser crystallization （ELC）. The process to prepare a sample includes two steps. One step cons...Polycrystalline silicon （poly-Si） thin film has been prepared by means of nickel-disilicide （NiSi2） assisted excimer laser crystallization （ELC）. The process to prepare a sample includes two steps. One step consists of the formation of NiSi2 precipitates by heat-treating the dehydrogenated amorphous silicon （a-Si） coated with a thin layer of Ni. And the other step consists of the formation of poly-Si grains by means of ELC. According to the test results of scanning electron microscopy （SEM）, another grain growth model named two-interface grain growth has been proposed to contrast with the conventional Ni-metal-induced lateral crystallization （Ni-MILC） model and the ELC model. That is, an additional grain growth interface other than that in conventional ELC is formed, which consists of NiSi2 precipitates and a-Si. The processes for grain growth according to various excimer laser energy densities delivered to the a-Si film have been discussed. It is discovered that grains with needle shape and most of a uniform orientation are formed which grow up with NiSi2 precipitates as seeds. The reason for the formation of such grains which are different from that of Ni-MILC without migration of Ni atoms is not clear. Our model and analysis point out a method to prepare grains with needle shape and mostly of a uniform orientation. If such grains are utilized to make thin-film transistor, its characteristics may be improved.展开更多
The diffusion and the activation of phosphorus in phosphorus and fluorine co-implanted Ge after being annealed by excimer laser are investigated.The results prove that the fluorine element plays an important role in s...The diffusion and the activation of phosphorus in phosphorus and fluorine co-implanted Ge after being annealed by excimer laser are investigated.The results prove that the fluorine element plays an important role in suppressing phosphorus diffusion and enhancing phosphorus activation.Moreover,the rapid thermal annealing process is utilized to evaluate and verify the role of fluorine element.During the initial annealing of co-implanted Ge,it is easier to form high bonding energy FnVm clusters which can stabilize the excess vacancies,resulting in the reduced vacancy-assisted diffusion of phosphorus.The maximum activation concentration of about 4.4 ×10^(20) cm^(-3) with a reduced diffusion length and dopant loss is achieved in co-implanted Ge that is annealed at a tailored laser fluence of 175 mJ/cm^(2).The combination of excimer laser annealing and co-implantation technique provides a reference and guideline for high level n-type doping in Ge and is beneficial to its applications in the scaled Ge MOSFET technology and other devices.展开更多
Surface of Al 2O 3 ceramic was processed by an excimer laser and the characteristics of topography were examined based on the application of the microelectromechanical system(MEMS). It is indicated that the statisti...Surface of Al 2O 3 ceramic was processed by an excimer laser and the characteristics of topography were examined based on the application of the microelectromechanical system(MEMS). It is indicated that the statistic parameters of surface topography processed by the excimer laser have an obvious regularity. The arithmetic-mean value R a and the root-mean square value R q change with the changing of processing parameters in the same step and trend, and there is a quantitative relation between them.A simplified model is proposed for the excimer laser processing surface profile, whose results of the analysis and calculation agree basically with the experimental data. Furthermore,the surfaces processed by excimer laser are greatly flat. Skewness root-mean-square value Z· q changed little with the change of the technological parameters. The above characteristics depend on the processing principle of excimer laser, quite different from the cutting processing.展开更多
The effect of domestically-manufactured excimer laser with adjunctive balloon angioplasty in achieving revascularization and reduction of residual stenosis was assessed. 20 femoral arteries with thrombosis and occlusi...The effect of domestically-manufactured excimer laser with adjunctive balloon angioplasty in achieving revascularization and reduction of residual stenosis was assessed. 20 femoral arteries with thrombosis and occlusion from 12 dogs were subject to angiography. At first excimer laser angioplasty was done followed by balloon angioplasty. The diameter and residual stenosis of revascularized vessel were measured. The result showed that 17 out of 20 vessels (85 %) were revascularized. The diameter of revascularized vessel by excimer laser were 1. 22±0.14 mm,while residual stenoses were 54 %±5%. After adjunctive balloon angioplasty the diameter and residual stenoses were 2. 04±0. 16 mm and 20 %±7 %respectively (P<0. 05 and P<0. 01), Complication in form of vasoperforation occurred in 3/20 vessels (15%). It is concluded that China-manufactured excimerlaser angioplasty is effective when used for revascularization. While the reduction of narrowing and residual stenoses was enhanced after adjunction of balloon angioplasty. This method can be employed in treating peripheral occlusive disease effectively and safely.展开更多
Changes of surface morphology following XeCI excimer laser irradiation were investigated for three engineering ceramic materials (Al2O3, Al2O3-SiC nanocomposite and Si3N4). Al2O3 and AI2O3-SiC nanocomposite samples ex...Changes of surface morphology following XeCI excimer laser irradiation were investigated for three engineering ceramic materials (Al2O3, Al2O3-SiC nanocomposite and Si3N4). Al2O3 and AI2O3-SiC nanocomposite samples exhibit a smooth rapid melt layer on the surface, and the formation of the metastabfe γ-Al2Oa was observed. A silicon-rich layer on the surface was formed after laser irradiation of Si3N4. The toughness K1c of the materials was measured by the indentation fracture method. After laser irradiation, the toughness of Al2O3, Al2O3-SiC nanocomposite and Si3N4 was improved to various degrees: Al2O3-SiC nanocomposite, 60% (max.); AI203, 40% (max.); Si3N4, 12% (max.).展开更多
Thin metallic layers (~ 2 μm) of Ni were deposited on polycrystalline Al2O3. ZrO2 and (Ce-TZP)+Al2O3 ceramic substrates. and further irradiated with pulsed excimer (Xeno chloride) laser pulses. The laser energy densi...Thin metallic layers (~ 2 μm) of Ni were deposited on polycrystalline Al2O3. ZrO2 and (Ce-TZP)+Al2O3 ceramic substrates. and further irradiated with pulsed excimer (Xeno chloride) laser pulses. The laser energy density was varied from 0.21 to 0.81 J / cm2 to optimize bending strength. For ZrO2 ceramic, it was found that the strength increases from 530 to 753 MPa at 0.51 J / cm2 irradiation. For Al2O3 and (Ce-TZP)+ Al2O3 the fracture strength also increases in varying degree. The causes of strength increment were discussed.展开更多
Formation and decay processes of pyrene excimer in acetonitrile have been measured by laser flash spectroscopy at 475nm,and the dependence of λ_1+λ_2 on the pyrene concentration has also been measured at 290°K....Formation and decay processes of pyrene excimer in acetonitrile have been measured by laser flash spectroscopy at 475nm,and the dependence of λ_1+λ_2 on the pyrene concentration has also been measured at 290°K.On the basis of these measurements,six rate parameters which describe the behaviour of pyrene excimer system in acetonitrile solution have been evaluated.At 355 nm laser light irradiation,the ΔG of the pyrene excimer formation in acetonitrile is evaluated to be -30.18kJ/mol. This value is quite different from the corresponding ΔG in cyclohexane (-16.72kJ/mol).展开更多
An optical fiber sensor for strain and temperature measurement based on long period fiber grating(LPFG) cascaded with fiber Bragg grating(FBG) structure has been proposed and realized both theoretically and experiment...An optical fiber sensor for strain and temperature measurement based on long period fiber grating(LPFG) cascaded with fiber Bragg grating(FBG) structure has been proposed and realized both theoretically and experimentally. Theoretical analysis shows that two microstructures with similar sensitivities cannot be used for double parameters measurement. The LPFG is micromachined by the CO_2 laser, and the FBG is micromachined by the excimer laser. For the validation and comparison, two FBGs and one LPFG are cascaded with three transmission valleys, namely FBG1 valley at 1 536.3 nm, LPFG valley at 1 551.2 nm, and FBG2 valley at 1 577.3 nm. The temperature and strain characteristics of the proposed sensor are measured at 45—70 °C and 250—500 με, respectively. The sensitivity matrix is determined by analyzing wavelength shifts and parameter response characterization of three different dips. The proposed optical fiber sensor based on LPFG cascaded with FBG structure can be efficiently used for double parameters measurement with promising application prospect and great research reference value.展开更多
In order to investigate the therapeutic effects of undercorrection following radial keratoto- my (RK) and photorefractive keratectomy (PRK) for correction of high myopia by excimer laser in situ keratomileusis (LASIK...In order to investigate the therapeutic effects of undercorrection following radial keratoto- my (RK) and photorefractive keratectomy (PRK) for correction of high myopia by excimer laser in situ keratomileusis (LASIK), LASIK was performed on 32 eyes of 16 patients undergoing RK 2 years ago and 38 eyes of 20 patients undergoing PRK 1 year ago. The postoperative uncorrected visu- al was better than or equal to the preoperative spectacle corrected visual acuity in 49 of 70 eyes (70. 00 %) and achieved the best status of refraction in 64 of 70 (91.43 %). The best postoperatively corrected visual in all operated eyes were equal to their preoperative ones respectively or just lost 1 line. No severe complication occurred during and after operation. It was suggested that LASIK was a better method for treatment of undercorrection following RK and PRK.展开更多
Navigation technology in ophthalmology,colloquially called“eye-tracking”,has been applied to various areas of eye care.This approach encompasses motion-based navigation technology in both ophthalmic imaging and trea...Navigation technology in ophthalmology,colloquially called“eye-tracking”,has been applied to various areas of eye care.This approach encompasses motion-based navigation technology in both ophthalmic imaging and treatment.For instance,modern imaging instruments use a real-time eye-tracking system,which helps to reduce motion artefacts and increase signal-to-noise ratio in imaging acquisition such as optical coherence tomography(OCT),microperimetry,and fluorescence and color imaging.Navigation in ophthalmic surgery has been firstly applied in laser vision corrective surgery and spread to involve navigated retinal photocoagulation,and positioning guidance of intraocular lenses(IOL)during cataract surgery.It has emerged as one of the most reliable representatives of technology as it continues to transform surgical interventions into safer,more standardized,and more predictable procedures with better outcomes.Eye-tracking is essential in refractive surgery with excimer laser ablation.Using this technology for cataract surgery in patients with high preoperative astigmatism has produced better therapeutic outcomes.Navigated retinal laser has proven to be safer and more accurate compared to the use of conventional slit lamp lasers.Eye-tracking has also been used in imaging diagnostics,where it is essential for proper alignment of captured zones of interest and accurate follow-up imaging.This technology is not routinely discussed in the ophthalmic literature even though it has been truly impactful in our clinical practice and represents a small revolution in ophthalmology.展开更多
A method to improve Ge n＋/p junction diode performance by excimer laser annealing （ELA） and epitaxial Si passi- vation under a low ion implantation dose is demonstrated. The epitaxial Si passivation layer can unpin...A method to improve Ge n＋/p junction diode performance by excimer laser annealing （ELA） and epitaxial Si passi- vation under a low ion implantation dose is demonstrated. The epitaxial Si passivation layer can unpin the Fermi level of the contact of Al/n-Ge to some extent and reduce the contact resistance. In addition, the fabricated Ge n ：/p junction diode by ELA plus epitaxial Si passivation exhibits a decreased reverse current density and an increased forward current density, resulting in a rectification ratio of about 6.5 x 10^6 beyond two orders magnitude larger than that by ELA alone. The reduced specific contact resistivity of metal on n-doped germanium and well-behaved germanium n＋/p diode arc beneficial for the performance improvement of Ge n-MOSFETs and other opto-electronic devices.展开更多
AIM:To evaluate the feasibility of promoting genetic detection for granular corneal dystrophy type 2(GCD2)by a questionnaire conducted among citizens in five cities in China.METHODS:The data were collected by question...AIM:To evaluate the feasibility of promoting genetic detection for granular corneal dystrophy type 2(GCD2)by a questionnaire conducted among citizens in five cities in China.METHODS:The data were collected by questionnaire,and analyzed by Chi-square test and one-tailed t test in IBM SPSS statistics.RESULTS:Based on the survey data on the awareness of GCD2 genetic detection in this study and the positive predictive analysis report of the citizens in five cities in China,the vast majority(84.2%)of respondents had never heard of it and did not know that GCD2 patients have been prohibited from performing excimer surgery that can deteriorate GCD2 patients’condition even leading to blindness.Though 3.4%of patients understood GCD2 very much,they have no idea that GCD2 could not be 100%accuracy diagnosed by the conventional inspection methods.CONCLUSION:It is feasible and necessary to use GCD2 genetic detection as an excimer preoperative examination project.In order to promote the development of detection project,a few improvements should be carried out in terms of the promoting efforts,costs,and research progress.展开更多
Objective To evaluate the relevant factors of regression phenomenon of laser in situ kerato-mileusis (LASIK) for treatment of myopia. Methods We studied 408 eyes of 250 myopic patients who received LASIK. Patients wer...Objective To evaluate the relevant factors of regression phenomenon of laser in situ kerato-mileusis (LASIK) for treatment of myopia. Methods We studied 408 eyes of 250 myopic patients who received LASIK. Patients were divided into 2 groups according to preoperative diopters (- 6 .00D- -10 .00D, 194 eyes;-10.10D- -15 .00D, 214 eyes). Mean period of follow-up were 12 months and the results were statistically analyzed. Results 12 months after surgery, in the first group (- 6.00--10.00D) the regressionequal to or beyond -1 .0D were 21 eyes (10.8%), range from -1 .0D to - 3 .0D. The average regression was -1.33D. In the second group (- 10 .10D - - 15 .00D) regression equal to or beyond -1.0D were 78 eyes (36.5%), range from -1 .0D to -5.50D. The average regression was -1 .99D. Conclusion The results indicate that excimer LASIK can be used to treat myopia between -6 .00D-- 15 .00D effectively with minimal regression within 12 months. Preoperative thin corneas with intraoperative small ablation zone could induce regression . Some modification of the surgical algorithms and laser nomogram will help to improve predictability and reduce regression.展开更多
Objective: To evaluate the effectiveness, predictability and city of laser in situ keratomileusis (LASIK) for correction of hyperopia. Methods 54 eyes of 35 patients with hyperopia ranging from+1.00 to + 6. 00 diopter...Objective: To evaluate the effectiveness, predictability and city of laser in situ keratomileusis (LASIK) for correction of hyperopia. Methods 54 eyes of 35 patients with hyperopia ranging from+1.00 to + 6. 00 diopter(D) received a one-pass, multizone scanning excimer laser ablations using the Chiron Technolas Keracor 11 7C excimer laser and System ALK automated corneal shaper H-230.Data on uncorrected and hot corrected visual acuity, predictability, stability of refraction, and complications were analyzed. The average follow-up was 12 months. Results At 12 months, the average residual refraction was(+ 0. 29 ±0. 78)D. 45 eyes (83.3% ) were in the range of ±1. OD and 33 eyes(61. 1% ) were within the range of ± 0. 5D. 50 eyes (92. 6% ) had uncorrected visual acuity of 20/40 or better and 34 eyes (63. 0% ) had 20/20 or better. 1 eyes (1. 9% ) lost 2 line of the best-corrected visual acuity and 2 eyes (3. 7% ) gained 2 lines or more. 2 eyes (3. 7%) had complaint of halos and 1 eyes (1. 9% ) had glare at 12 months. Conclusion LASIK can he used to treat hyperopia from + 1. 0D to + 6. 0D with good predictability and city. Primary and second hyperopia should he treated with different nomogram. some modification of the surgical algorithms and laser nomogram will help to improve predictability and stability of outcome.展开更多
文摘We report on the impact of direct ultraviolet germicidal irradiation（UVGI）on reflective optics,used in the excimer laser system Allegretto Eye-Q.The aim of our work was to confirm our hypothesis based on long-rate observations of obtained anomalies in post-operative results that are attributed to degradation of reflective optics upon ultraviolet radiation.The presence of direct UVGI coupled with humidity in the operating environment caused merging anomalies and unwanted post-operative correction values.Ultraviolet-A radiation caused a similar effect on the reflective cover of the mirrors.
文摘Ge self-assembled quantum dots （SAQDs） are grown with a self-assembled UHV/CVD epitaxy system. Then, the as-grown Ge quantum dots are annealed by ArF excimer laser. In the ultra-shot laser pulse duration, -20ns, bulk diffusion is forbidden,and only surface diffusion occurs, resulting in a laser induced quantum dot （LIQD）. The diameter of the LIQD is 20-25nm which is much smaller than the as-grown dot and the LIQD has a higher density of about 6 ×10^10cm^-2. The surface morphology evolution is investigated by AFM.
文摘Ablation experiments of A950 Liquid Crystal Polymer (LCP), as a kind of typical matrix of fibre reinforced polymer composites, are carried out in this paper. Data on the ablation of A950 LCP by excimer laser at 248 nm are presented. The experimental results show that the ablation depth is a linear function of the number of pulse at constant laser fluence, The ablation rate varies with the logorithm of the fluence in a linear manner at different fluences. A satisfactory linear relationship is found between ablation energy and incident fluence. Perhaps due to the plume absorption and thermal effect, the ablation rate varies complicatedly with pulse repetition frequency.
文摘In this study,a KrF excimer laser was used to modify the biodegradable Mg-1Ca alloy and the time-evolution degradation behavior of the alloy before and after laser treatment was investigated in simulated body fluid(SBF)solution using immersion tests and electrochemical impedance spectroscopy(EIS).A 5μm melted layer with a homogeneous microstructure and an MgO film on the surface were achieved by laser radiation.Corrosion observations(hydrogen evolution,morphology and corrosion products)and EIS results revealed an improvement of corrosion resistance after laser treatment for 48 h.It was found a two-layer structure developed after 2 h immersion on both the untreated and laser-treated alloys,but the sequence of forming the two layers was opposite and greatly influenced by the laser-treated layer.The time-evolution corrosion processes on the untreated and laser-treated alloys were discussed,providing a better understanding of corrosion behavior of biodegradable Mg alloys modified by excimer laser.
基金Supported by Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(No.2022L201)。
文摘AIM:To investigate the size of functional optical zone(FOZ)after small incision lenticule extraction(SMILE)versus femtosecond laser assisted excimer laser keratomileusis(FS-LASIK)for myopia correction and potential associated factors for FOZ.METHODS:A total of 133 patients who received corneal refractive surgery in our hospital between November 2018 and July 2021 were retrospectively enrolled.There were 63 patients(123 eyes)in SMILE group and 70patients(139 eyes)in FS-LASIK group.The size of FOZ was measured using Pentacam 3-dementional anterior segment analyzer before and 3mo after surgery,so as to analyze postoperative achieved functional optical zone(AFOZ)and its contributing parameters.RESULTS:When planned functional optical zone(PFOZ)was 6.5 mm for both groups,AFOZ was 1.45±0.27 and 1.67±0.25 mm smaller than preoperative FOZ in SMILE group and FS-LASIK group 3mo after surgery.AFOZ in SMILE group was significantly larger than that in FS-LASIK group(P<0.001).Variation of FOZ was negatively correlated with preoperative spherical equivalent(SE)and positively correlated with variation of mean keratometry value(△Km),variation of spherical aberration(△SA),and variation of Q-value(△Q,all P<0.001)in both groups.Multiple variable linear regression equations were△FOZ=1.354-0.1×pre-SE+0.336×△Q+1.462×△SA in SMILE group and△FOZ=1.512+0.137×△Q+0.468×△SA in FS-LASIK group.CONCLUSION:AFOZ is significantly smaller than preoperative FOZ in both SMILE and FS-LASIK groups.With the same PFOZ,larger AFOZ is achieved in SMILE group than in FS-LASIK group.
文摘BACKGROUND Percutaneous coronary intervention can be challenging for ostial coronary artery lesions due to calcium burden and elastic fiber content.Excimer laser coronary atherectomy(ELCA)is a less common treatment for severe calcified coronary ostium lesions.CASE SUMMARY An 81-year-old male presented to the Cardiology Department of Qingdao Municipal Hospital with a 1-year history of chest pain.Coronary angiography showed severe calcific stenosis(approximately 90%)in the right coronary artery ostium.The right coronary artery ostium was unable to be advanced using a 2.5 mm×12.0 mm balloon(NC Sprinter,Medtronic,United States)or dilated using a 2.0 mm×12.0 mm balloon(Sprinter,Medtronic,United States).The patient underwent successful ELCA and balloon dilation of the calcified coronary ostium lesion.CONCLUSION ELCA appears to be a safe and effective treatment for the management of severe calcified coronary ostium lesions.
基金Project supported by the National High Technology Development Program of China （Grant No 2002AA303250） and by the National Natural Science Foundation of China （Grant No 60576056）.
文摘Polycrystalline silicon （poly-Si） thin film has been prepared by means of nickel-disilicide （NiSi2） assisted excimer laser crystallization （ELC）. The process to prepare a sample includes two steps. One step consists of the formation of NiSi2 precipitates by heat-treating the dehydrogenated amorphous silicon （a-Si） coated with a thin layer of Ni. And the other step consists of the formation of poly-Si grains by means of ELC. According to the test results of scanning electron microscopy （SEM）, another grain growth model named two-interface grain growth has been proposed to contrast with the conventional Ni-metal-induced lateral crystallization （Ni-MILC） model and the ELC model. That is, an additional grain growth interface other than that in conventional ELC is formed, which consists of NiSi2 precipitates and a-Si. The processes for grain growth according to various excimer laser energy densities delivered to the a-Si film have been discussed. It is discovered that grains with needle shape and most of a uniform orientation are formed which grow up with NiSi2 precipitates as seeds. The reason for the formation of such grains which are different from that of Ni-MILC without migration of Ni atoms is not clear. Our model and analysis point out a method to prepare grains with needle shape and mostly of a uniform orientation. If such grains are utilized to make thin-film transistor, its characteristics may be improved.
基金Project supported by the National Natural Science Foundation of China(Grant No.61904155)the Science and technology Project of Fujian Provincial Department of Education,China(Grant No.JAT200484)+1 种基金the Natural Science Foundation of Fujian Province,China(Grant No.2018J05115)the Scientific Research Projects of Xiamen University of Technology,China(Grant No.YKJCX2020078).
文摘The diffusion and the activation of phosphorus in phosphorus and fluorine co-implanted Ge after being annealed by excimer laser are investigated.The results prove that the fluorine element plays an important role in suppressing phosphorus diffusion and enhancing phosphorus activation.Moreover,the rapid thermal annealing process is utilized to evaluate and verify the role of fluorine element.During the initial annealing of co-implanted Ge,it is easier to form high bonding energy FnVm clusters which can stabilize the excess vacancies,resulting in the reduced vacancy-assisted diffusion of phosphorus.The maximum activation concentration of about 4.4 ×10^(20) cm^(-3) with a reduced diffusion length and dopant loss is achieved in co-implanted Ge that is annealed at a tailored laser fluence of 175 mJ/cm^(2).The combination of excimer laser annealing and co-implantation technique provides a reference and guideline for high level n-type doping in Ge and is beneficial to its applications in the scaled Ge MOSFET technology and other devices.
文摘Surface of Al 2O 3 ceramic was processed by an excimer laser and the characteristics of topography were examined based on the application of the microelectromechanical system(MEMS). It is indicated that the statistic parameters of surface topography processed by the excimer laser have an obvious regularity. The arithmetic-mean value R a and the root-mean square value R q change with the changing of processing parameters in the same step and trend, and there is a quantitative relation between them.A simplified model is proposed for the excimer laser processing surface profile, whose results of the analysis and calculation agree basically with the experimental data. Furthermore,the surfaces processed by excimer laser are greatly flat. Skewness root-mean-square value Z· q changed little with the change of the technological parameters. The above characteristics depend on the processing principle of excimer laser, quite different from the cutting processing.
文摘The effect of domestically-manufactured excimer laser with adjunctive balloon angioplasty in achieving revascularization and reduction of residual stenosis was assessed. 20 femoral arteries with thrombosis and occlusion from 12 dogs were subject to angiography. At first excimer laser angioplasty was done followed by balloon angioplasty. The diameter and residual stenosis of revascularized vessel were measured. The result showed that 17 out of 20 vessels (85 %) were revascularized. The diameter of revascularized vessel by excimer laser were 1. 22±0.14 mm,while residual stenoses were 54 %±5%. After adjunctive balloon angioplasty the diameter and residual stenoses were 2. 04±0. 16 mm and 20 %±7 %respectively (P<0. 05 and P<0. 01), Complication in form of vasoperforation occurred in 3/20 vessels (15%). It is concluded that China-manufactured excimerlaser angioplasty is effective when used for revascularization. While the reduction of narrowing and residual stenoses was enhanced after adjunction of balloon angioplasty. This method can be employed in treating peripheral occlusive disease effectively and safely.
文摘Changes of surface morphology following XeCI excimer laser irradiation were investigated for three engineering ceramic materials (Al2O3, Al2O3-SiC nanocomposite and Si3N4). Al2O3 and AI2O3-SiC nanocomposite samples exhibit a smooth rapid melt layer on the surface, and the formation of the metastabfe γ-Al2Oa was observed. A silicon-rich layer on the surface was formed after laser irradiation of Si3N4. The toughness K1c of the materials was measured by the indentation fracture method. After laser irradiation, the toughness of Al2O3, Al2O3-SiC nanocomposite and Si3N4 was improved to various degrees: Al2O3-SiC nanocomposite, 60% (max.); AI203, 40% (max.); Si3N4, 12% (max.).
文摘Thin metallic layers (~ 2 μm) of Ni were deposited on polycrystalline Al2O3. ZrO2 and (Ce-TZP)+Al2O3 ceramic substrates. and further irradiated with pulsed excimer (Xeno chloride) laser pulses. The laser energy density was varied from 0.21 to 0.81 J / cm2 to optimize bending strength. For ZrO2 ceramic, it was found that the strength increases from 530 to 753 MPa at 0.51 J / cm2 irradiation. For Al2O3 and (Ce-TZP)+ Al2O3 the fracture strength also increases in varying degree. The causes of strength increment were discussed.
文摘Formation and decay processes of pyrene excimer in acetonitrile have been measured by laser flash spectroscopy at 475nm,and the dependence of λ_1+λ_2 on the pyrene concentration has also been measured at 290°K.On the basis of these measurements,six rate parameters which describe the behaviour of pyrene excimer system in acetonitrile solution have been evaluated.At 355 nm laser light irradiation,the ΔG of the pyrene excimer formation in acetonitrile is evaluated to be -30.18kJ/mol. This value is quite different from the corresponding ΔG in cyclohexane (-16.72kJ/mol).
基金supported by the Program for Changjiang Scholars and Innovative Research Team in University(No.IRT_16R07)the Project Plan of Beijing Municipal Education Commission for Enhancing the Innovation Capability in 2015(No.TJSHG201510772016)the Open Project of Beijing Engineering Research Center of Optoelectronic Information and Instruments(No.GD2016008)
文摘An optical fiber sensor for strain and temperature measurement based on long period fiber grating(LPFG) cascaded with fiber Bragg grating(FBG) structure has been proposed and realized both theoretically and experimentally. Theoretical analysis shows that two microstructures with similar sensitivities cannot be used for double parameters measurement. The LPFG is micromachined by the CO_2 laser, and the FBG is micromachined by the excimer laser. For the validation and comparison, two FBGs and one LPFG are cascaded with three transmission valleys, namely FBG1 valley at 1 536.3 nm, LPFG valley at 1 551.2 nm, and FBG2 valley at 1 577.3 nm. The temperature and strain characteristics of the proposed sensor are measured at 45—70 °C and 250—500 με, respectively. The sensitivity matrix is determined by analyzing wavelength shifts and parameter response characterization of three different dips. The proposed optical fiber sensor based on LPFG cascaded with FBG structure can be efficiently used for double parameters measurement with promising application prospect and great research reference value.
文摘In order to investigate the therapeutic effects of undercorrection following radial keratoto- my (RK) and photorefractive keratectomy (PRK) for correction of high myopia by excimer laser in situ keratomileusis (LASIK), LASIK was performed on 32 eyes of 16 patients undergoing RK 2 years ago and 38 eyes of 20 patients undergoing PRK 1 year ago. The postoperative uncorrected visu- al was better than or equal to the preoperative spectacle corrected visual acuity in 49 of 70 eyes (70. 00 %) and achieved the best status of refraction in 64 of 70 (91.43 %). The best postoperatively corrected visual in all operated eyes were equal to their preoperative ones respectively or just lost 1 line. No severe complication occurred during and after operation. It was suggested that LASIK was a better method for treatment of undercorrection following RK and PRK.
文摘Navigation technology in ophthalmology,colloquially called“eye-tracking”,has been applied to various areas of eye care.This approach encompasses motion-based navigation technology in both ophthalmic imaging and treatment.For instance,modern imaging instruments use a real-time eye-tracking system,which helps to reduce motion artefacts and increase signal-to-noise ratio in imaging acquisition such as optical coherence tomography(OCT),microperimetry,and fluorescence and color imaging.Navigation in ophthalmic surgery has been firstly applied in laser vision corrective surgery and spread to involve navigated retinal photocoagulation,and positioning guidance of intraocular lenses(IOL)during cataract surgery.It has emerged as one of the most reliable representatives of technology as it continues to transform surgical interventions into safer,more standardized,and more predictable procedures with better outcomes.Eye-tracking is essential in refractive surgery with excimer laser ablation.Using this technology for cataract surgery in patients with high preoperative astigmatism has produced better therapeutic outcomes.Navigated retinal laser has proven to be safer and more accurate compared to the use of conventional slit lamp lasers.Eye-tracking has also been used in imaging diagnostics,where it is essential for proper alignment of captured zones of interest and accurate follow-up imaging.This technology is not routinely discussed in the ophthalmic literature even though it has been truly impactful in our clinical practice and represents a small revolution in ophthalmology.
基金Project supported by the High Level Talent Project of Xiamen University of Technology,China(Grant No.YKJ16012R)
文摘A method to improve Ge n＋/p junction diode performance by excimer laser annealing （ELA） and epitaxial Si passi- vation under a low ion implantation dose is demonstrated. The epitaxial Si passivation layer can unpin the Fermi level of the contact of Al/n-Ge to some extent and reduce the contact resistance. In addition, the fabricated Ge n ：/p junction diode by ELA plus epitaxial Si passivation exhibits a decreased reverse current density and an increased forward current density, resulting in a rectification ratio of about 6.5 x 10^6 beyond two orders magnitude larger than that by ELA alone. The reduced specific contact resistivity of metal on n-doped germanium and well-behaved germanium n＋/p diode arc beneficial for the performance improvement of Ge n-MOSFETs and other opto-electronic devices.
基金Supported by National Natural Science Foundation of China(No.81570870)Natural Science Foundation of Fujian Province(No.2016J01375)Innovation and Entrepreneurship Training Program of Fujian Medical University(No.C4015,No.C19067,No.S202010392022X)。
文摘AIM:To evaluate the feasibility of promoting genetic detection for granular corneal dystrophy type 2(GCD2)by a questionnaire conducted among citizens in five cities in China.METHODS:The data were collected by questionnaire,and analyzed by Chi-square test and one-tailed t test in IBM SPSS statistics.RESULTS:Based on the survey data on the awareness of GCD2 genetic detection in this study and the positive predictive analysis report of the citizens in five cities in China,the vast majority(84.2%)of respondents had never heard of it and did not know that GCD2 patients have been prohibited from performing excimer surgery that can deteriorate GCD2 patients’condition even leading to blindness.Though 3.4%of patients understood GCD2 very much,they have no idea that GCD2 could not be 100%accuracy diagnosed by the conventional inspection methods.CONCLUSION:It is feasible and necessary to use GCD2 genetic detection as an excimer preoperative examination project.In order to promote the development of detection project,a few improvements should be carried out in terms of the promoting efforts,costs,and research progress.
文摘Objective To evaluate the relevant factors of regression phenomenon of laser in situ kerato-mileusis (LASIK) for treatment of myopia. Methods We studied 408 eyes of 250 myopic patients who received LASIK. Patients were divided into 2 groups according to preoperative diopters (- 6 .00D- -10 .00D, 194 eyes;-10.10D- -15 .00D, 214 eyes). Mean period of follow-up were 12 months and the results were statistically analyzed. Results 12 months after surgery, in the first group (- 6.00--10.00D) the regressionequal to or beyond -1 .0D were 21 eyes (10.8%), range from -1 .0D to - 3 .0D. The average regression was -1.33D. In the second group (- 10 .10D - - 15 .00D) regression equal to or beyond -1.0D were 78 eyes (36.5%), range from -1 .0D to -5.50D. The average regression was -1 .99D. Conclusion The results indicate that excimer LASIK can be used to treat myopia between -6 .00D-- 15 .00D effectively with minimal regression within 12 months. Preoperative thin corneas with intraoperative small ablation zone could induce regression . Some modification of the surgical algorithms and laser nomogram will help to improve predictability and reduce regression.
文摘Objective: To evaluate the effectiveness, predictability and city of laser in situ keratomileusis (LASIK) for correction of hyperopia. Methods 54 eyes of 35 patients with hyperopia ranging from+1.00 to + 6. 00 diopter(D) received a one-pass, multizone scanning excimer laser ablations using the Chiron Technolas Keracor 11 7C excimer laser and System ALK automated corneal shaper H-230.Data on uncorrected and hot corrected visual acuity, predictability, stability of refraction, and complications were analyzed. The average follow-up was 12 months. Results At 12 months, the average residual refraction was(+ 0. 29 ±0. 78)D. 45 eyes (83.3% ) were in the range of ±1. OD and 33 eyes(61. 1% ) were within the range of ± 0. 5D. 50 eyes (92. 6% ) had uncorrected visual acuity of 20/40 or better and 34 eyes (63. 0% ) had 20/20 or better. 1 eyes (1. 9% ) lost 2 line of the best-corrected visual acuity and 2 eyes (3. 7% ) gained 2 lines or more. 2 eyes (3. 7%) had complaint of halos and 1 eyes (1. 9% ) had glare at 12 months. Conclusion LASIK can he used to treat hyperopia from + 1. 0D to + 6. 0D with good predictability and city. Primary and second hyperopia should he treated with different nomogram. some modification of the surgical algorithms and laser nomogram will help to improve predictability and stability of outcome.
