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
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
In percutaneous coronary intervention (PCI), chronic total occlusion (CTO) coronary artery disease still remains difficult to treat. One of the reasons for the failure is the hard of the CTO lesions that balloon is di...In percutaneous coronary intervention (PCI), chronic total occlusion (CTO) coronary artery disease still remains difficult to treat. One of the reasons for the failure is the hard of the CTO lesions that balloon is difficult to pass through or expand. Previous methods to deal with CTO lesions that cannot be passed by balloon, include selecting reinforced catheter (such as 5 in 6 guiding catheter, Guidzilla catheter, or Tornus microcatheter), guidewire extrusion or rotary grinding technology. In recent years, excimer laser coronary angioplasty (ELCA) has been gradually applied to CTO lesions. Using inert halide as the laser medium, ELCA emits a 308 nm high-intensity unidirectional light wave with absorption depth of only 50 μmL, resulting in less thermal effect and less damage to non-target lesions. In this paper, we will describe a successful PCI case of an in-stent CTO lesion using ELCA with long term coronary angiography follow-up.展开更多
Patients presenting with recurrence of anginal symptoms after saphenous vein bypass surgery pose an increasingly frequent challenge.In general,approximately 40%to 50%of saphenous vein graft(SVG)will become diseased or...Patients presenting with recurrence of anginal symptoms after saphenous vein bypass surgery pose an increasingly frequent challenge.In general,approximately 40%to 50%of saphenous vein graft(SVG)will become diseased or occluded within the first ten years after surgery.[1]Because adverse clinical outcomes,such as high restenosis rates and distal embolization,have been reported,percutaneous coronary intervention(PCI)for SVG is not recommended as a first-line strategy.[2]Distal embolization occurs in 2%–17%of patients despite advances in therapy,including the utilization of embolic protection device(EPD),which may lead to increased mortality at both short follow-up and midterm follow-up.[3]However,these patients often associated with inappropriate anatomic characteristics of native vessel intervention including calcification,tortuosity,abundant plaque burden,and complex chronic total occlusion(CTO)lesions.Moreover,repeat coronary bypass surgery is an option but is technically more demanding and is associated with a higher mortality.Therefore,it can sometimes result in SVG stenosis being the only intervention option.This is why the recanalization of SVG lesions,especially totally occluded lesions,remains one of the most challenging procedures in interventional cardiology.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
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
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
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
Dear Editor,I am Chihiro Koiwa,from the Department of Ophthalmology,Juntendo University Hospital.I am writing this letter to present a case of multiple excimer laser phototherapeutic keratectomies(PTKs)for Avellino co...Dear Editor,I am Chihiro Koiwa,from the Department of Ophthalmology,Juntendo University Hospital.I am writing this letter to present a case of multiple excimer laser phototherapeutic keratectomies(PTKs)for Avellino corneal dystrophy(ACD).Corneal dystrophy is a common type of hereditary,noninflammatory,and bilateral corneal disorder that involves various pathological,histological,and clinical manifestations[1].Advanced molecular gene sequencing has identified specific mutations that are associated with most dystrophies of this type.ACD,also known as granular corneal dystrophy typeⅡ[2],is autosomal dominant and associated with the R124H mutation of the transforming growth factor beta-induced(TGFBI)gene and characterized by deposits consistent with both discrete granular and lattice corneal opacities[3-4].An analysis of the TGFBI gene is essential to differentiate ACD because heterozygous R124H mutation carriers have minimal corneal abnormalities,whereas homozygotes have severe visual impairment,starting from early childhood,and early postoperative recurrence of corneal opacity.展开更多
Purpose: To study the clinical manifestations and histopathologic changes of trabeculum after excimer laser trabeculectomy ab interno (ELT), and to investigate the mechanisms of ELT in reducing intraocular pressure.Me...Purpose: To study the clinical manifestations and histopathologic changes of trabeculum after excimer laser trabeculectomy ab interno (ELT), and to investigate the mechanisms of ELT in reducing intraocular pressure.Methods : ELT was performed on ten rabbit eves and postoperative responses were documented. Comeoscleral tissue samples were harvested consecutively each week until the 5th postoperative week and these samples were examined under light and electrical microscopy.Results: Mild stimulation signs were present postoperatix'ely in nine of ten eyes, but no serious complications were experienced. Obvious inflammation was observed in one rabbit eye as a result of iris damage during the surgical manipulations. Local kactures on the trabecular meshwork and openings into Schlemm' s canal were detected in all tissue samples under light microscope. Mitochondria were found to be turgescent and dilated like vacuoles and endoplasmic reticula were found to be dilated under electrical microscope in the early postoperative period. Later, all trabecular cells returned normal and no fihroblast cells were ever detected.Conclusions: Permanent openings through trabecular meshwork into the inner wall of Schlemm's canal can be created with ELT. The outflow resistance of aqueous humor can be reduced with these openings and intraocular pressure can be controlled thereafter. Eye Science 2001; 17:11 ～ 15.展开更多
AIM: To compare and evaluate the clinical outcomes of deep anterior lamellar keratoplasty(DALK) and excimer laser assisted anterior lamellar keratoplasty(ELLK) in eyes with keratoconus.METHODS: In this study, 57 eyes ...AIM: To compare and evaluate the clinical outcomes of deep anterior lamellar keratoplasty(DALK) and excimer laser assisted anterior lamellar keratoplasty(ELLK) in eyes with keratoconus.METHODS: In this study, 57 eyes of 56 patients operated between 2013 to 2017 were included. Thirty-one eyes underwent big-bubble DALK and twenty-six eyes underwent ELLK. Preoperative and at control visits complete ophthalmic examination was performed. RESULTS: The mean patient age at the time of DALK surgery was 27 y and mean follow-up period was 21±5.4 mo. The mean patient age at the time of ELLK surgery was 27 y and mean follow-up period was 40±18 mo. Mean best spectacle corrected visual acuity(BSCVA) at postoperative period was significantly higher for DALK group(0.66±0.11) versus ELLK group(0.4±0.2)(P<0.05). Descemet's membrane microperforation was occurred in 7 patients in DALK group versus in 1 patient in ELLK group. In 4 eyes, interface irregularity was developed in ELLK group. None of the patients in follow-up had graft rejection in both groups.CONCLUSION: In ELLK group, complication rate is lower, the surgical technique is simpler, faster and safer and also ELLK requires less experience with respect to DALK. Further, DALK can be performed unless satisfactory visual acuity is achieved after ELLK.展开更多
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
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
We reported 11 cases of excimer laser coronary angioplasty (ELCA). All were males, the average age being 59.7 years. Five patients had sustained previous myocardial infarctions with post-infarction angina in 2 cases a...We reported 11 cases of excimer laser coronary angioplasty (ELCA). All were males, the average age being 59.7 years. Five patients had sustained previous myocardial infarctions with post-infarction angina in 2 cases and 6 presented angina only. Coronary angiograms showed stenosis in LAD (N9), LCX(N6) and RCA (N6). According to the ACC/AHA classification, 6 were categorized as type B, and 5 type C. ELCA with adjunctive PTCA were performed in all 8 patients, 1. 3 mm (energy density 14. 5 mJ) and 1.6 mm (energy density 21.0 mJ) laser catheters with 20Hz pulse frequency were used There was one failure and in another ELCA was successful but death followed the procedure. The overall result was laser success 10 out of the 11 cases and procedure success 9.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
-Purpose: To evaluate early visual, refractive and aberrometric outcomes after wave front-guided LASIK for the correction of low to moderate myopia and myopic astigmat is musing the excimer laser platform Advanced Cus...-Purpose: To evaluate early visual, refractive and aberrometric outcomes after wave front-guided LASIK for the correction of low to moderate myopia and myopic astigmat is musing the excimer laser platform Advanced Custom Vue. Methods: A prospective, non-comparative study in 100 myopic eyes of 50 patients evaluating LASIK results over a period of 3 months. Main outcome variables included visual acuity, refraction, total higher-order aberrations (HOAs), spherical aberration (SA) and coma-like aberration. The surgery was performed using the VISX STAR S4 (Johnson and Johnson Vision) excimer laser and a wave front-guided ablation designed according to the iDesign aberrometer data (Johnson and Johnson Vision). Results: Mean preoperative sphere decreased from -4.07 ± 1.78 D to 0.32 ± 0.30 D at 3 months after surgery. Mean preoperative cylinder was reduced from -1.09 ± 0.88 D to -0.26 ± 0.28 D after the complete follow-up. Postoperative uncorrected distance visual acuity (UDVA) was 0.00 logMAR (20/20) or better in 100% of eyes, and 65.3% of eyes reached an UDVA of -0.20 logMAR (20/12.5) or better (p < 0.05). For a 6-mm pupil, the root mean square (RMS) for total ocular HOAs increased with surgery by 0.03 μm (p = 0.050), whereas the coma-like RMS increased by 0.05 μm (p < 0.001). The change in spherical aberration was +0.08 μm (p < 0.001). Conclusion: Wavefront-guided LASIK using the new generation excimer laser platform Advanced Custom Vue is safe and effective for treating myopia and myopic astigmatism, minimizing the postoperative level of HOAs.展开更多
Background: Refractive surgery may change the individual life to the better largely eliminating the need for spectacles. However, expectations may vary and postoperative reality may come as a surprise. Aim: To emphasi...Background: Refractive surgery may change the individual life to the better largely eliminating the need for spectacles. However, expectations may vary and postoperative reality may come as a surprise. Aim: To emphasize the need for thorough alignment of expectations and options between surgeon and patient. Methods: A case is presented in which a successful refractive laser operation is a part of a trigger mechanism for a depressive episode leading to suicide. It emphasizes the crucial importance of constructive alignment of expectations between patient and treating physician prior to surgery. Results: The case presented outlines that ophthalmic surgery at the edge of high-tec with all its tempting features is also very attractive to individuals with very well defined and less flexible expectations. The possible irreversibility of some of the refractive surgery may force the patient postoperatively into a psychological corner, immobilizing him/her and restricting his/her options. Conclusions: High-tec operations dealing with one of the most elementary senses we have, vision, demand a thorough estimation of the patients profile prior to any surgery. Only matching expectations between the possible and desired outcome and reconfirmation of the match may reduce the risk of postoperative crisis which may carry a risk the patient’s life.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
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In percutaneous coronary intervention (PCI), chronic total occlusion (CTO) coronary artery disease still remains difficult to treat. One of the reasons for the failure is the hard of the CTO lesions that balloon is difficult to pass through or expand. Previous methods to deal with CTO lesions that cannot be passed by balloon, include selecting reinforced catheter (such as 5 in 6 guiding catheter, Guidzilla catheter, or Tornus microcatheter), guidewire extrusion or rotary grinding technology. In recent years, excimer laser coronary angioplasty (ELCA) has been gradually applied to CTO lesions. Using inert halide as the laser medium, ELCA emits a 308 nm high-intensity unidirectional light wave with absorption depth of only 50 μmL, resulting in less thermal effect and less damage to non-target lesions. In this paper, we will describe a successful PCI case of an in-stent CTO lesion using ELCA with long term coronary angiography follow-up.
文摘Patients presenting with recurrence of anginal symptoms after saphenous vein bypass surgery pose an increasingly frequent challenge.In general,approximately 40%to 50%of saphenous vein graft(SVG)will become diseased or occluded within the first ten years after surgery.[1]Because adverse clinical outcomes,such as high restenosis rates and distal embolization,have been reported,percutaneous coronary intervention(PCI)for SVG is not recommended as a first-line strategy.[2]Distal embolization occurs in 2%–17%of patients despite advances in therapy,including the utilization of embolic protection device(EPD),which may lead to increased mortality at both short follow-up and midterm follow-up.[3]However,these patients often associated with inappropriate anatomic characteristics of native vessel intervention including calcification,tortuosity,abundant plaque burden,and complex chronic total occlusion(CTO)lesions.Moreover,repeat coronary bypass surgery is an option but is technically more demanding and is associated with a higher mortality.Therefore,it can sometimes result in SVG stenosis being the only intervention option.This is why the recanalization of SVG lesions,especially totally occluded lesions,remains one of the most challenging procedures in interventional cardiology.
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.
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Dear Editor,I am Chihiro Koiwa,from the Department of Ophthalmology,Juntendo University Hospital.I am writing this letter to present a case of multiple excimer laser phototherapeutic keratectomies(PTKs)for Avellino corneal dystrophy(ACD).Corneal dystrophy is a common type of hereditary,noninflammatory,and bilateral corneal disorder that involves various pathological,histological,and clinical manifestations[1].Advanced molecular gene sequencing has identified specific mutations that are associated with most dystrophies of this type.ACD,also known as granular corneal dystrophy typeⅡ[2],is autosomal dominant and associated with the R124H mutation of the transforming growth factor beta-induced(TGFBI)gene and characterized by deposits consistent with both discrete granular and lattice corneal opacities[3-4].An analysis of the TGFBI gene is essential to differentiate ACD because heterozygous R124H mutation carriers have minimal corneal abnormalities,whereas homozygotes have severe visual impairment,starting from early childhood,and early postoperative recurrence of corneal opacity.
文摘Purpose: To study the clinical manifestations and histopathologic changes of trabeculum after excimer laser trabeculectomy ab interno (ELT), and to investigate the mechanisms of ELT in reducing intraocular pressure.Methods : ELT was performed on ten rabbit eves and postoperative responses were documented. Comeoscleral tissue samples were harvested consecutively each week until the 5th postoperative week and these samples were examined under light and electrical microscopy.Results: Mild stimulation signs were present postoperatix'ely in nine of ten eyes, but no serious complications were experienced. Obvious inflammation was observed in one rabbit eye as a result of iris damage during the surgical manipulations. Local kactures on the trabecular meshwork and openings into Schlemm' s canal were detected in all tissue samples under light microscope. Mitochondria were found to be turgescent and dilated like vacuoles and endoplasmic reticula were found to be dilated under electrical microscope in the early postoperative period. Later, all trabecular cells returned normal and no fihroblast cells were ever detected.Conclusions: Permanent openings through trabecular meshwork into the inner wall of Schlemm's canal can be created with ELT. The outflow resistance of aqueous humor can be reduced with these openings and intraocular pressure can be controlled thereafter. Eye Science 2001; 17:11 ～ 15.
文摘AIM: To compare and evaluate the clinical outcomes of deep anterior lamellar keratoplasty(DALK) and excimer laser assisted anterior lamellar keratoplasty(ELLK) in eyes with keratoconus.METHODS: In this study, 57 eyes of 56 patients operated between 2013 to 2017 were included. Thirty-one eyes underwent big-bubble DALK and twenty-six eyes underwent ELLK. Preoperative and at control visits complete ophthalmic examination was performed. RESULTS: The mean patient age at the time of DALK surgery was 27 y and mean follow-up period was 21±5.4 mo. The mean patient age at the time of ELLK surgery was 27 y and mean follow-up period was 40±18 mo. Mean best spectacle corrected visual acuity(BSCVA) at postoperative period was significantly higher for DALK group(0.66±0.11) versus ELLK group(0.4±0.2)(P<0.05). Descemet's membrane microperforation was occurred in 7 patients in DALK group versus in 1 patient in ELLK group. In 4 eyes, interface irregularity was developed in ELLK group. None of the patients in follow-up had graft rejection in both groups.CONCLUSION: In ELLK group, complication rate is lower, the surgical technique is simpler, faster and safer and also ELLK requires less experience with respect to DALK. Further, DALK can be performed unless satisfactory visual acuity is achieved after ELLK.
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We reported 11 cases of excimer laser coronary angioplasty (ELCA). All were males, the average age being 59.7 years. Five patients had sustained previous myocardial infarctions with post-infarction angina in 2 cases and 6 presented angina only. Coronary angiograms showed stenosis in LAD (N9), LCX(N6) and RCA (N6). According to the ACC/AHA classification, 6 were categorized as type B, and 5 type C. ELCA with adjunctive PTCA were performed in all 8 patients, 1. 3 mm (energy density 14. 5 mJ) and 1.6 mm (energy density 21.0 mJ) laser catheters with 20Hz pulse frequency were used There was one failure and in another ELCA was successful but death followed the procedure. The overall result was laser success 10 out of the 11 cases and procedure success 9.
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-Purpose: To evaluate early visual, refractive and aberrometric outcomes after wave front-guided LASIK for the correction of low to moderate myopia and myopic astigmat is musing the excimer laser platform Advanced Custom Vue. Methods: A prospective, non-comparative study in 100 myopic eyes of 50 patients evaluating LASIK results over a period of 3 months. Main outcome variables included visual acuity, refraction, total higher-order aberrations (HOAs), spherical aberration (SA) and coma-like aberration. The surgery was performed using the VISX STAR S4 (Johnson and Johnson Vision) excimer laser and a wave front-guided ablation designed according to the iDesign aberrometer data (Johnson and Johnson Vision). Results: Mean preoperative sphere decreased from -4.07 ± 1.78 D to 0.32 ± 0.30 D at 3 months after surgery. Mean preoperative cylinder was reduced from -1.09 ± 0.88 D to -0.26 ± 0.28 D after the complete follow-up. Postoperative uncorrected distance visual acuity (UDVA) was 0.00 logMAR (20/20) or better in 100% of eyes, and 65.3% of eyes reached an UDVA of -0.20 logMAR (20/12.5) or better (p < 0.05). For a 6-mm pupil, the root mean square (RMS) for total ocular HOAs increased with surgery by 0.03 μm (p = 0.050), whereas the coma-like RMS increased by 0.05 μm (p < 0.001). The change in spherical aberration was +0.08 μm (p < 0.001). Conclusion: Wavefront-guided LASIK using the new generation excimer laser platform Advanced Custom Vue is safe and effective for treating myopia and myopic astigmatism, minimizing the postoperative level of HOAs.
文摘Background: Refractive surgery may change the individual life to the better largely eliminating the need for spectacles. However, expectations may vary and postoperative reality may come as a surprise. Aim: To emphasize the need for thorough alignment of expectations and options between surgeon and patient. Methods: A case is presented in which a successful refractive laser operation is a part of a trigger mechanism for a depressive episode leading to suicide. It emphasizes the crucial importance of constructive alignment of expectations between patient and treating physician prior to surgery. Results: The case presented outlines that ophthalmic surgery at the edge of high-tec with all its tempting features is also very attractive to individuals with very well defined and less flexible expectations. The possible irreversibility of some of the refractive surgery may force the patient postoperatively into a psychological corner, immobilizing him/her and restricting his/her options. Conclusions: High-tec operations dealing with one of the most elementary senses we have, vision, demand a thorough estimation of the patients profile prior to any surgery. Only matching expectations between the possible and desired outcome and reconfirmation of the match may reduce the risk of postoperative crisis which may carry a risk the patient’s life.
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.
