Purpose: To evaluate the efficacy and safety of transepithelial collagen cross-linking by iontophoretic delivery of riboflavin in treatment of progressive keratoconus.Methods:.Eleven patients(15 eyes) with progressive...Purpose: To evaluate the efficacy and safety of transepithelial collagen cross-linking by iontophoretic delivery of riboflavin in treatment of progressive keratoconus.Methods:.Eleven patients(15 eyes) with progressive keratoconus were enrolled. After 0.1% riboflavin-distilled water solution was deliveried via transepithelial iontophpresis for 5 min with 1 m A current, and ultraviolet radiation(370 nm,.3 m W /cm2) was performed at a 1.5 cm distance for 30 min. The follow up were 6 months in all eyes. The uncorrected visual acuity, corrected visual acuity,endothelial cell counting, corneal thickness,.intraocular pressure, corneal curvature, corneal topography,.OCT and corneal opacity before and 6-month after surgery were analyzed.Results: At 6 month postoperatively, mean uncorrected visual acuity and corrected visual acuity changed from 0.36 to 0.30 and from 0.42 to 0.57 without statistical significance..The mean value of each index of corneal curvature declined without statistical significance.Kmax value dereased from 60.91 to59.91, and the astigmatism declined from 3.86 to 3.19. Central corneal thickness decreased from 460.93 μm to 455.40μm,.and thinnest corneal thickness declined from 450.87 μm to 440.60 μm with no statistical significance..Intraocular pressure was significantly elevated from 10.85 mm Hg to 12.62 mm Hg. Endothelial cell count did not change significantly. No corneal haze occurred. Mean depth of corneal demarcation line was 288.46 μm at 1 month postoperatively..Conclusion:.Transepithelial corneal collagen cross-linking by iontophoresis is effective and safe in the treatment of progressive keratoconus, and yields stable clinical outcomes during 6-month follow up..However,.long-term follow up is urgently required.展开更多
Purpose:To evaluate the efficacy and safety of pranoprofen eye drops for reducing postoperative ocular pain and inflammation after corneal cross-linking (CXL). Methods:Twenty-seven patients (38 eyes) with keratoconus ...Purpose:To evaluate the efficacy and safety of pranoprofen eye drops for reducing postoperative ocular pain and inflammation after corneal cross-linking (CXL). Methods:Twenty-seven patients (38 eyes) with keratoconus undergoing CXL were examined and randomly divided into control (12 cases; 18 eyes) and experimental groups (15 cases;20 eyes).The patients in the control group were given fluorometholone eye drops,and those in the experimental group were administered with fluorometholone combined with pranoprofen eye drops.Corneal irritation and haze were compared between the two groups at 1 month postoperatively. Results:At 1 to 3 days after surgery,the corneal irritation in the experimental group was significantly reduced compared with that in the control group (P<0.05), but there was no significant difference on 5 to 7 days postoperatively (P>0.05). The average degree of haze in the experimental group was significantly lower than that in the control group 1 month after surgery (P<0.05), but there was no significant difference in the best-corrected vision acuity and intraocular pressure between the two groups. There were 2 cases with >20 mmHg intraocular pressure in the control group. Conclusion:The combined use of fluorometholone and pranoprofen can significantly reduce inflammatory response,alleviate corneal irritation at early stage after CXL,effectively prevent and control the average of haze,and reduce the incidence of steroid-induced ocular hypertension after surgery.展开更多
Magnesium-based hydrogen storage materials are considered as one of the most promising candidates for solid state hydrogen storage due to their advantages of high hydrogen capacity,excellent reversibility and low cost...Magnesium-based hydrogen storage materials are considered as one of the most promising candidates for solid state hydrogen storage due to their advantages of high hydrogen capacity,excellent reversibility and low cost.In this paper,Mg_(91.4)Ni_(7)Y_(1.6) and Mg_(92.8)Ni_(2.4)Y_(4.8) alloys were prepared by melting and ball milling.Their microstructures and phases were characterized by X-ray diffraction,scanning electron microscope and transmission electron microscope,and hydrogen absorbing and desorbing properties were tested by the high pressure gas adsorption apparatus and differential scanning calorimetry(DSC).In order to estimate the activation energy and growth mechanism of alloy hydride,the JMAK,Arrhenius and Kissinger methods were applied for calculation.The hydrogen absorption content of Mg_(92.8)Ni_(2.4)Y_(4.8) alloy reaches 3.84 wt.%within 5 min under 350℃,3 MPa,and the maximum hydrogen capacity of the alloy is 4.89 wt.%in same condition.However,the hydrogen absorption of Mg_(91.4)Ni_(7)Y_(1.6) alloy reaches 5.78 wt.%within 5 min,and the maximum hydrogen absorption of the alloy is 6.44 wt.%at 350℃and 3 MPa.The hydrogenation activation energy of Mg_(94.4)Ni_(7)Y_(1.6) alloy is 25.4 kJ/mol H_(2),and the enthalpy and entropy of hydrogen absorption are-60.6 kJ/mol H_(2) and 105.5 J/K/mol H_(2),separately.The alloy begins to dehydrogenate at 210℃,with the dehydrogenation activation energy of 87.7 kJ/mol H_(2).By altering the addition amount of Ni and Y elements,the 14 H-LPSO phase with smaller size and ternary eutectic areas with high volume fraction are obtained,which provides more phase boundaries and catalysts with better dispersion,and there are a lot of fine particles in the alloy,these structures are beneficial to enhance the hydrogen storage performance of the alloys.展开更多
AIM:To report the clinical results of iontophoresis-assisted epithelium-on corneal crosslinking(I-CXL) using 0.1% riboflavin in distilled water for progressive keratoconus. METHODS:In this prospective clinical stu...AIM:To report the clinical results of iontophoresis-assisted epithelium-on corneal crosslinking(I-CXL) using 0.1% riboflavin in distilled water for progressive keratoconus. METHODS:In this prospective clinical study, we examined 94 eyes of 75 patients with progressive keratoconus who were treated with I-CXL using 0.1% riboflavin in distilled water. Best correct visual acuity(BCVA), Scheimpflug tomography, corneal topography, anterior segment optical coherence tomography, intraocular pressure, and endothelial cell density were evaluated at baseline and 1, 3, 6, 12, and 24 mo after I-CXL.RESULTS:After 24 mo I-CXL, compared to the level at baseline, BCVA significantly improved 0.14±0.07(P=0.010); mean keratometry signifi cantly decreased 0.72±1.97(P=0.021); maximum keratometry significantly reduced 2.30±5.01(P=0.014); central keratoconus index significantly reduced 0.04±0.08(P=0.007). The demarcation line was visible in 83.1% of eyes at 1mo after treatment, with a depth of 298.95±51.97 μm, and gradually indistinguishable. One eye had repeat treatment. Intraocular pressure and endothelial cell density did not change significantly.CONCLUSION:I-CXL using 0.1% riboflavin halts keratoconus progression within 24 mo, resulting in a significant improvement in visual and topographic parameters. Moreover, the depth of the demarcation line is similar to that previously reported in standard epithelium-off CXL procedures.展开更多
AIM: To evaluate the enrichment of riboflavin in the corneal stroma after intracameral injection to research the barrier ability of the corneal endothelium to riboflavin in vivo.METHODS: The right eyes of 30 New Zeala...AIM: To evaluate the enrichment of riboflavin in the corneal stroma after intracameral injection to research the barrier ability of the corneal endothelium to riboflavin in vivo.METHODS: The right eyes of 30 New Zealand white rabbits were divided into three groups. Different concentrations riboflavin-balanced salt solutions(BSS)were injected into the anterior chamber(10 with 0.5%, 10 with 1%, and 10 with 2%). Eight corneal buttons of 8.5mm in diameter from each group were dissected at 30 min after injection and the riboflavin concentrations in the corneal stroma were determined using high-performance liquid chromatography(HPLC) after removing the epithelium and endothelium. The other two rabbits in every group were observed for 24 h and sacrificed. As a comparison, the riboflavin concentrations from 16 corneal stromal samples were determined using HPLC after instillation of 0.1% riboflavin-BSS solution for30 min on the corneal surface(8 without epithelium and 8with intact epithelium).RESULTS: The mean riboflavin concentrations were11.19, 18.97, 25.08, 20.18, and 1.13 μg/g for 0.5%, 1%, 2%,de-epithelialzed samples, and the transepithelial groups,respectively. The color change of the corneal stroma and the HPLC results showed that enrichment with riboflavin similar to classical de-epithelialized corneal collagen crosslinking(CXL) could be achieved by intracameral 1%riboflavin-BSS solution after 30min; the effect appeared to be continuous for at least 30 min.CONCLUSION: Riboflavin can effectively penetrate the corneal stroma through the endothelium after an intracameral injection in vivo, so it could be an enhancing method that could improve the corneal riboflavin concentration in transepithelial CXL.展开更多
AIM:To observe changes in the content of matrix metalloproteinases(MMPs)in the corneal stroma after corneal cross-linking(CXL)in rabbits,and further explore the corneal pathophysiological process after CXL.METHODS:For...AIM:To observe changes in the content of matrix metalloproteinases(MMPs)in the corneal stroma after corneal cross-linking(CXL)in rabbits,and further explore the corneal pathophysiological process after CXL.METHODS:Forty-two rabbits(42 eyes)were randomly divided into seven groups.One group served as the control group,while the other six groups were treated with CXL.The concentrations of MMPs in corneal stroma were evaluated through parallel reaction monitoring at baseline and 3,7,15,30,90,and 180 d after treatment.RESULTS:The levels of MMP-2 in the corneal stroma of rabbits were 0.76±0.07,2.78±1.39,4.12±0.69,2.00±0.29,2.00±0.30,1.22±0.18,and 1.35±0.18(10^(-9)mol/g)at baseline and 3,7,15,30,90,and 180 d after treatment,respectively.The contents of tissue inhibitor of metalloproteinase-1(TIMP-1)were 1.83±0.26,7.94±0.58,6.95±2.64,3.81±0.48,3.07±0.92,1.72±0.19,and 1.69±0.74(10^(-9)mol/g),respectively.The ratios of MMP-2/TIMP-1 were 0.42±0.33,0.36±0.20,0.62±0.10,0.54±0.15,0.68±0.13,0.71±0.10,and 0.68±0.09,respectively.After CXL,the expression of MMP-2 and TIMP-1 in the rabbit corneal stroma was initially increased and subsequently decreased.The levels of MMP-2 remained higher than those recorded at baseline 180 d after treatment,but it was not statistically significant.The levels of TIMP-1 returned to baseline levels at 90 d after treatment.The ratio of MMP-2/TIMP-1 started to rise from 7 d after CXL.It was significantly higher than that calculated at baseline 30-180 d after CXL.The results for MMP-1,-3,-7,-9,-13,and TIMP-2 were negative.CONCLUSION:CXL can lead to changes in the content of MMP-2 and TIMP-1 in the rabbit corneal stroma.The ratio of MMP-2/TIMP-1 remains higher versus baseline,indicating that MMP-2 is involved in the corneal pathophysiological process after CXL.展开更多
Ditian 6 is super sweet corn hybrid. Its parents are inbred line 201-2 and 769 respectively. It was certificated by Variety Certification Committee of Shanxi Province in 2013. Ditian 6 participated in regional trials ...Ditian 6 is super sweet corn hybrid. Its parents are inbred line 201-2 and 769 respectively. It was certificated by Variety Certification Committee of Shanxi Province in 2013. Ditian 6 participated in regional trials of Shanxi Province in 2010 and 2011. The average fresh ear yield is 14257. 5 kg / ha. Its growth period is 81 d,belonging to the early variety. It has obvious advantages if it is early cultivated. The kernel is yellow,and the quality reaches a high level. In the early or late market,it has significant economic benefits. The variety has strong resistance to disease and adversity,with wide adaptability,high and stable yield. It can be planted in the areas where accumulated temperature is above 2300℃.展开更多
Purpose:To assess the effect of having an open or closed eye on the variation in central corneal thickness during riboflavin instillation for corneal collagen cross-linking (CXL).Methods:.Thirty eyes of 15 New Zealand...Purpose:To assess the effect of having an open or closed eye on the variation in central corneal thickness during riboflavin instillation for corneal collagen cross-linking (CXL).Methods:.Thirty eyes of 15 New Zealand White rabbits underwent an in vivo anterior segment optical coherence tomography (OCT) examination at 0,10,20,and 30 min after riboflavin instillation on the de-epithelialized corneal surface.Each eye of every rabbit was randomly placed into one of two different treatment groups(open-eye or closed-eye)during the instillation;.the examinations were performed one after the other.After instillation for 30 min,the changes in the corneal stroma and anterior chamber were observed by slit lamp.Results:.A significant decrease in the central corneal thickness(CCT).was demonstrated during riboflavin instillation;.the variations were smaller in the measurements performed with the eye closed than with the eye open.(81.36±15.13μm and129.20±12.05μm respectively)..Both methods turned the corneal stroma and anterior chamber yellow.Conclusion:Keeping the eye closed during riboflavin instillation reduced the decrease in the CCT..The same yellow change in the corneal stroma and anterior chamber occurred,but the exposure time of the ocular surface was shorter.Therefore,.keeping the eye closed was a more effective and safer method than keeping the eye open.展开更多
Purpose:To study variation in central corneal thickness (CCT) during corneal collagen cross-linking(CXL) using ultrasound pachymetry. Methods:Twenty patients (26 eyes) with progressing keratoconus undergoing riboflavi...Purpose:To study variation in central corneal thickness (CCT) during corneal collagen cross-linking(CXL) using ultrasound pachymetry. Methods:Twenty patients (26 eyes) with progressing keratoconus undergoing riboflavin-UVA-induced CXL were involved in this study. Intraoperative CCT measurement using ultrasonic pachymetry was performed during the procedure.Measurements were obtained before operation, after epithelial removal, after riboflavin drop instillation, and after UVA irradiation. Results:Mean CCT was 495±56 and 450±52 μm before and after epithelial removal, respectively. Mean CCT was 443±42 and 411±39 μm after riboflavin drop instillation and after UVA irradiation, respectively. Statistically significant decreases in CCT occurred between the preoperative period and after epithelial removal, after riboflavin drop instillation and after UVA irradiation. Twenty-six eyes from 20 patients undergoing CXL were divided into 2 groups (I with CCT≥400 μm after UVA irradiation and II with CCT<400 μm after UVA irradiation). No statistically significant difference was noted between I and II in preoperative endothelial cell count, but a statistically greater postoperative endothelial cell count was noted in I compared to II. A statistically significant difference was evident between preoperative and postoperative endothelial cell counts in Group II (P<0.05). Conclusion:Performing CXL with the use of riboflavin and UVA irradiation resulted in a statistically significant decrease in CCT, to a level where the corneal endothelium may be damaged.(Eye Science 2013; 28:15-19)展开更多
Background:To compare the safety and efficacy of iontophoresis-assisted epithelial-on corneal crosslinking(I-CXL)using 0.1%riboflavin-distilled water solution with standard epithelium-off corneal crosslinking(S-CXL)fo...Background:To compare the safety and efficacy of iontophoresis-assisted epithelial-on corneal crosslinking(I-CXL)using 0.1%riboflavin-distilled water solution with standard epithelium-off corneal crosslinking(S-CXL)for progressive keratoconus.Methods:In a retrospective analysis,progressive keratoconus patients treated with I-CXL(17 eyes of 17 patients)or S-CXL(13 eyes of 13 patients)were included.All patients were followed up at least 12 months.All patients underwent detailed ophthalmologic examinations involving pre-and postoperative visual acuity,topographic parameters and pachymetry.Intra-and postoperative complications were recorded.Results:No statistically significant differences were observed between the two groups at baseline with respect to visual acuity,age and thinnest corneal thickness(TCT).The postoperative decreases of K1 and Kmean in the S-CXL group represented statistically significantly better results than in the I-CXL group(t=2.093 and 2.123,P=0.046 and 0.043,respectively).Alterations of other parameters showed no significant differences between the two groups.There were no failure cases in the two groups.Conclusions:I-CXL using 0.1%riboflavin-distilled water solution provided effective treatment for progressive keratoconus at 12-month follow-up.However,the decreases of K1 and Kmean caused by I-CXL were less than those by S-CXL.Although treatment time,postoperative patient pain and risk of infection in I-CXL are all less than those in S-CXL,I-CXL is unable to completely replace S-CXL for progressive keratoconus temporarily.展开更多
文摘Purpose: To evaluate the efficacy and safety of transepithelial collagen cross-linking by iontophoretic delivery of riboflavin in treatment of progressive keratoconus.Methods:.Eleven patients(15 eyes) with progressive keratoconus were enrolled. After 0.1% riboflavin-distilled water solution was deliveried via transepithelial iontophpresis for 5 min with 1 m A current, and ultraviolet radiation(370 nm,.3 m W /cm2) was performed at a 1.5 cm distance for 30 min. The follow up were 6 months in all eyes. The uncorrected visual acuity, corrected visual acuity,endothelial cell counting, corneal thickness,.intraocular pressure, corneal curvature, corneal topography,.OCT and corneal opacity before and 6-month after surgery were analyzed.Results: At 6 month postoperatively, mean uncorrected visual acuity and corrected visual acuity changed from 0.36 to 0.30 and from 0.42 to 0.57 without statistical significance..The mean value of each index of corneal curvature declined without statistical significance.Kmax value dereased from 60.91 to59.91, and the astigmatism declined from 3.86 to 3.19. Central corneal thickness decreased from 460.93 μm to 455.40μm,.and thinnest corneal thickness declined from 450.87 μm to 440.60 μm with no statistical significance..Intraocular pressure was significantly elevated from 10.85 mm Hg to 12.62 mm Hg. Endothelial cell count did not change significantly. No corneal haze occurred. Mean depth of corneal demarcation line was 288.46 μm at 1 month postoperatively..Conclusion:.Transepithelial corneal collagen cross-linking by iontophoresis is effective and safe in the treatment of progressive keratoconus, and yields stable clinical outcomes during 6-month follow up..However,.long-term follow up is urgently required.
文摘Purpose:To evaluate the efficacy and safety of pranoprofen eye drops for reducing postoperative ocular pain and inflammation after corneal cross-linking (CXL). Methods:Twenty-seven patients (38 eyes) with keratoconus undergoing CXL were examined and randomly divided into control (12 cases; 18 eyes) and experimental groups (15 cases;20 eyes).The patients in the control group were given fluorometholone eye drops,and those in the experimental group were administered with fluorometholone combined with pranoprofen eye drops.Corneal irritation and haze were compared between the two groups at 1 month postoperatively. Results:At 1 to 3 days after surgery,the corneal irritation in the experimental group was significantly reduced compared with that in the control group (P<0.05), but there was no significant difference on 5 to 7 days postoperatively (P>0.05). The average degree of haze in the experimental group was significantly lower than that in the control group 1 month after surgery (P<0.05), but there was no significant difference in the best-corrected vision acuity and intraocular pressure between the two groups. There were 2 cases with >20 mmHg intraocular pressure in the control group. Conclusion:The combined use of fluorometholone and pranoprofen can significantly reduce inflammatory response,alleviate corneal irritation at early stage after CXL,effectively prevent and control the average of haze,and reduce the incidence of steroid-induced ocular hypertension after surgery.
基金Chongqing Special Key Project of Technology Innovation and Application Development,China(Grant No.cstc2019jscx-dxwt B0029)。
文摘Magnesium-based hydrogen storage materials are considered as one of the most promising candidates for solid state hydrogen storage due to their advantages of high hydrogen capacity,excellent reversibility and low cost.In this paper,Mg_(91.4)Ni_(7)Y_(1.6) and Mg_(92.8)Ni_(2.4)Y_(4.8) alloys were prepared by melting and ball milling.Their microstructures and phases were characterized by X-ray diffraction,scanning electron microscope and transmission electron microscope,and hydrogen absorbing and desorbing properties were tested by the high pressure gas adsorption apparatus and differential scanning calorimetry(DSC).In order to estimate the activation energy and growth mechanism of alloy hydride,the JMAK,Arrhenius and Kissinger methods were applied for calculation.The hydrogen absorption content of Mg_(92.8)Ni_(2.4)Y_(4.8) alloy reaches 3.84 wt.%within 5 min under 350℃,3 MPa,and the maximum hydrogen capacity of the alloy is 4.89 wt.%in same condition.However,the hydrogen absorption of Mg_(91.4)Ni_(7)Y_(1.6) alloy reaches 5.78 wt.%within 5 min,and the maximum hydrogen absorption of the alloy is 6.44 wt.%at 350℃and 3 MPa.The hydrogenation activation energy of Mg_(94.4)Ni_(7)Y_(1.6) alloy is 25.4 kJ/mol H_(2),and the enthalpy and entropy of hydrogen absorption are-60.6 kJ/mol H_(2) and 105.5 J/K/mol H_(2),separately.The alloy begins to dehydrogenate at 210℃,with the dehydrogenation activation energy of 87.7 kJ/mol H_(2).By altering the addition amount of Ni and Y elements,the 14 H-LPSO phase with smaller size and ternary eutectic areas with high volume fraction are obtained,which provides more phase boundaries and catalysts with better dispersion,and there are a lot of fine particles in the alloy,these structures are beneficial to enhance the hydrogen storage performance of the alloys.
基金Supported by Beijing Municipal Science and Technology Commission(No.Z151100004015217)
文摘AIM:To report the clinical results of iontophoresis-assisted epithelium-on corneal crosslinking(I-CXL) using 0.1% riboflavin in distilled water for progressive keratoconus. METHODS:In this prospective clinical study, we examined 94 eyes of 75 patients with progressive keratoconus who were treated with I-CXL using 0.1% riboflavin in distilled water. Best correct visual acuity(BCVA), Scheimpflug tomography, corneal topography, anterior segment optical coherence tomography, intraocular pressure, and endothelial cell density were evaluated at baseline and 1, 3, 6, 12, and 24 mo after I-CXL.RESULTS:After 24 mo I-CXL, compared to the level at baseline, BCVA significantly improved 0.14±0.07(P=0.010); mean keratometry signifi cantly decreased 0.72±1.97(P=0.021); maximum keratometry significantly reduced 2.30±5.01(P=0.014); central keratoconus index significantly reduced 0.04±0.08(P=0.007). The demarcation line was visible in 83.1% of eyes at 1mo after treatment, with a depth of 298.95±51.97 μm, and gradually indistinguishable. One eye had repeat treatment. Intraocular pressure and endothelial cell density did not change significantly.CONCLUSION:I-CXL using 0.1% riboflavin halts keratoconus progression within 24 mo, resulting in a significant improvement in visual and topographic parameters. Moreover, the depth of the demarcation line is similar to that previously reported in standard epithelium-off CXL procedures.
文摘AIM: To evaluate the enrichment of riboflavin in the corneal stroma after intracameral injection to research the barrier ability of the corneal endothelium to riboflavin in vivo.METHODS: The right eyes of 30 New Zealand white rabbits were divided into three groups. Different concentrations riboflavin-balanced salt solutions(BSS)were injected into the anterior chamber(10 with 0.5%, 10 with 1%, and 10 with 2%). Eight corneal buttons of 8.5mm in diameter from each group were dissected at 30 min after injection and the riboflavin concentrations in the corneal stroma were determined using high-performance liquid chromatography(HPLC) after removing the epithelium and endothelium. The other two rabbits in every group were observed for 24 h and sacrificed. As a comparison, the riboflavin concentrations from 16 corneal stromal samples were determined using HPLC after instillation of 0.1% riboflavin-BSS solution for30 min on the corneal surface(8 without epithelium and 8with intact epithelium).RESULTS: The mean riboflavin concentrations were11.19, 18.97, 25.08, 20.18, and 1.13 μg/g for 0.5%, 1%, 2%,de-epithelialzed samples, and the transepithelial groups,respectively. The color change of the corneal stroma and the HPLC results showed that enrichment with riboflavin similar to classical de-epithelialized corneal collagen crosslinking(CXL) could be achieved by intracameral 1%riboflavin-BSS solution after 30min; the effect appeared to be continuous for at least 30 min.CONCLUSION: Riboflavin can effectively penetrate the corneal stroma through the endothelium after an intracameral injection in vivo, so it could be an enhancing method that could improve the corneal riboflavin concentration in transepithelial CXL.
基金Supported by Beijing Municipal Science and Technology Commission(No.Z151100004015217)。
文摘AIM:To observe changes in the content of matrix metalloproteinases(MMPs)in the corneal stroma after corneal cross-linking(CXL)in rabbits,and further explore the corneal pathophysiological process after CXL.METHODS:Forty-two rabbits(42 eyes)were randomly divided into seven groups.One group served as the control group,while the other six groups were treated with CXL.The concentrations of MMPs in corneal stroma were evaluated through parallel reaction monitoring at baseline and 3,7,15,30,90,and 180 d after treatment.RESULTS:The levels of MMP-2 in the corneal stroma of rabbits were 0.76±0.07,2.78±1.39,4.12±0.69,2.00±0.29,2.00±0.30,1.22±0.18,and 1.35±0.18(10^(-9)mol/g)at baseline and 3,7,15,30,90,and 180 d after treatment,respectively.The contents of tissue inhibitor of metalloproteinase-1(TIMP-1)were 1.83±0.26,7.94±0.58,6.95±2.64,3.81±0.48,3.07±0.92,1.72±0.19,and 1.69±0.74(10^(-9)mol/g),respectively.The ratios of MMP-2/TIMP-1 were 0.42±0.33,0.36±0.20,0.62±0.10,0.54±0.15,0.68±0.13,0.71±0.10,and 0.68±0.09,respectively.After CXL,the expression of MMP-2 and TIMP-1 in the rabbit corneal stroma was initially increased and subsequently decreased.The levels of MMP-2 remained higher than those recorded at baseline 180 d after treatment,but it was not statistically significant.The levels of TIMP-1 returned to baseline levels at 90 d after treatment.The ratio of MMP-2/TIMP-1 started to rise from 7 d after CXL.It was significantly higher than that calculated at baseline 30-180 d after CXL.The results for MMP-1,-3,-7,-9,-13,and TIMP-2 were negative.CONCLUSION:CXL can lead to changes in the content of MMP-2 and TIMP-1 in the rabbit corneal stroma.The ratio of MMP-2/TIMP-1 remains higher versus baseline,indicating that MMP-2 is involved in the corneal pathophysiological process after CXL.
基金Supported by Breeding Project of Shanxi Academy of Agricultural Sciences(11yzgc026)
文摘Ditian 6 is super sweet corn hybrid. Its parents are inbred line 201-2 and 769 respectively. It was certificated by Variety Certification Committee of Shanxi Province in 2013. Ditian 6 participated in regional trials of Shanxi Province in 2010 and 2011. The average fresh ear yield is 14257. 5 kg / ha. Its growth period is 81 d,belonging to the early variety. It has obvious advantages if it is early cultivated. The kernel is yellow,and the quality reaches a high level. In the early or late market,it has significant economic benefits. The variety has strong resistance to disease and adversity,with wide adaptability,high and stable yield. It can be planted in the areas where accumulated temperature is above 2300℃.
文摘Purpose:To assess the effect of having an open or closed eye on the variation in central corneal thickness during riboflavin instillation for corneal collagen cross-linking (CXL).Methods:.Thirty eyes of 15 New Zealand White rabbits underwent an in vivo anterior segment optical coherence tomography (OCT) examination at 0,10,20,and 30 min after riboflavin instillation on the de-epithelialized corneal surface.Each eye of every rabbit was randomly placed into one of two different treatment groups(open-eye or closed-eye)during the instillation;.the examinations were performed one after the other.After instillation for 30 min,the changes in the corneal stroma and anterior chamber were observed by slit lamp.Results:.A significant decrease in the central corneal thickness(CCT).was demonstrated during riboflavin instillation;.the variations were smaller in the measurements performed with the eye closed than with the eye open.(81.36±15.13μm and129.20±12.05μm respectively)..Both methods turned the corneal stroma and anterior chamber yellow.Conclusion:Keeping the eye closed during riboflavin instillation reduced the decrease in the CCT..The same yellow change in the corneal stroma and anterior chamber occurred,but the exposure time of the ocular surface was shorter.Therefore,.keeping the eye closed was a more effective and safer method than keeping the eye open.
文摘Purpose:To study variation in central corneal thickness (CCT) during corneal collagen cross-linking(CXL) using ultrasound pachymetry. Methods:Twenty patients (26 eyes) with progressing keratoconus undergoing riboflavin-UVA-induced CXL were involved in this study. Intraoperative CCT measurement using ultrasonic pachymetry was performed during the procedure.Measurements were obtained before operation, after epithelial removal, after riboflavin drop instillation, and after UVA irradiation. Results:Mean CCT was 495±56 and 450±52 μm before and after epithelial removal, respectively. Mean CCT was 443±42 and 411±39 μm after riboflavin drop instillation and after UVA irradiation, respectively. Statistically significant decreases in CCT occurred between the preoperative period and after epithelial removal, after riboflavin drop instillation and after UVA irradiation. Twenty-six eyes from 20 patients undergoing CXL were divided into 2 groups (I with CCT≥400 μm after UVA irradiation and II with CCT<400 μm after UVA irradiation). No statistically significant difference was noted between I and II in preoperative endothelial cell count, but a statistically greater postoperative endothelial cell count was noted in I compared to II. A statistically significant difference was evident between preoperative and postoperative endothelial cell counts in Group II (P<0.05). Conclusion:Performing CXL with the use of riboflavin and UVA irradiation resulted in a statistically significant decrease in CCT, to a level where the corneal endothelium may be damaged.(Eye Science 2013; 28:15-19)
基金This work was suppor ted by Beijing Municipal Science and Technology Commission(No.Z151100004015217).
文摘Background:To compare the safety and efficacy of iontophoresis-assisted epithelial-on corneal crosslinking(I-CXL)using 0.1%riboflavin-distilled water solution with standard epithelium-off corneal crosslinking(S-CXL)for progressive keratoconus.Methods:In a retrospective analysis,progressive keratoconus patients treated with I-CXL(17 eyes of 17 patients)or S-CXL(13 eyes of 13 patients)were included.All patients were followed up at least 12 months.All patients underwent detailed ophthalmologic examinations involving pre-and postoperative visual acuity,topographic parameters and pachymetry.Intra-and postoperative complications were recorded.Results:No statistically significant differences were observed between the two groups at baseline with respect to visual acuity,age and thinnest corneal thickness(TCT).The postoperative decreases of K1 and Kmean in the S-CXL group represented statistically significantly better results than in the I-CXL group(t=2.093 and 2.123,P=0.046 and 0.043,respectively).Alterations of other parameters showed no significant differences between the two groups.There were no failure cases in the two groups.Conclusions:I-CXL using 0.1%riboflavin-distilled water solution provided effective treatment for progressive keratoconus at 12-month follow-up.However,the decreases of K1 and Kmean caused by I-CXL were less than those by S-CXL.Although treatment time,postoperative patient pain and risk of infection in I-CXL are all less than those in S-CXL,I-CXL is unable to completely replace S-CXL for progressive keratoconus temporarily.