AIM:To investigate the effects of adenosine triphosphate(ATP)and melatonin,which have antioxidant and antiinflammatory activities,on potential 5-fluorouracil(5-FU)-induced optic nerve damage in rats.METHODS:Twenty-fou...AIM:To investigate the effects of adenosine triphosphate(ATP)and melatonin,which have antioxidant and antiinflammatory activities,on potential 5-fluorouracil(5-FU)-induced optic nerve damage in rats.METHODS:Twenty-four rats were categorized into four groups of six rats:healthy(HG),5-FU(FUG),ATP+5-FU(AFU),and melatonin+5-FU(MFU).ATP(4 mg/kg)and melatonin(10 mg/kg)were administered intraperitoneally and orally,respectively.One hour after ATP and melatonin administration,rats in the AFU,MFU,and FUG were intraperitoneally injected with 5-FU(100 mg/kg).ATP and melatonin were administered once daily for 10d.5-FU was administered at a single dose on days 1,3,and 5 of the experiment.After 10d,the rats were euthanized and optic nerve tissues were extracted.Optic nerve tissues were biochemically and histopathologically examined.RESULTS:ATP and melatonin treatments inhibited the increase in malondialdehyde(MDA)and interleukin-6(IL-6)levels,which were elevated in the FUG.The treatments also prevented the decrease in total glutathione(tGSH)levels and the superoxide dismutase(SOD)and catalase(CAT)activities(P<0.001).This inhibition was higher in the ATP group than in the melatonin group(P<0.001).ATP prevented histopathological damage better than melatonin(P<0.05).CONCLUSION:ATP and melatonin have the potential to be used in alleviating 5-FU-induced optic nerve damage.In addition,ATP treatment shows better protective effects than melatonin.展开更多
Retinal ganglion cells are the bridging neurons between the eye and the central nervous system,transmitting visual signals to the brain.The injury and loss of retinal ganglion cells are the primary pathological change...Retinal ganglion cells are the bridging neurons between the eye and the central nervous system,transmitting visual signals to the brain.The injury and loss of retinal ganglion cells are the primary pathological changes in several retinal degenerative diseases,including glaucoma,ischemic optic neuropathy,diabetic neuropathy,and optic neuritis.In mammals,injured retinal ganglion cells lack regenerative capacity and undergo apoptotic cell death within a few days of injury.Additionally,these cells exhibit limited regenerative ability,ultimately contributing to vision impairment and potentially leading to blindness.Currently,the only effective clinical treatment for glaucoma is to prevent vision loss by lowering intraocular pressure through medications or surgery;however,this approach cannot halt the effect of retinal ganglion cell loss on visual function.This review comprehensively investigates the mechanisms underlying retinal ganglion cell degeneration in retinal degenerative diseases and further explores the current status and potential of cell replacement therapy for regenerating retinal ganglion cells.As our understanding of the complex processes involved in retinal ganglion cell degeneration deepens,we can explore new treatment strategies,such as cell transplantation,which may offer more effective ways to mitigate the effect of retinal degenerative diseases on vision.展开更多
A theory of excitation of ultrasonic waves in the stimulated Brillouin scattering （SBS） process is presented in this paper. By using several reasonable approximations, a numerical calculation of the transient longit...A theory of excitation of ultrasonic waves in the stimulated Brillouin scattering （SBS） process is presented in this paper. By using several reasonable approximations, a numerical calculation of the transient longitudinal SBS shows that large amplitude of acoustic waves can be built up by the nanosecond pulse of high-power laser, which may result in the damage of optical glasses. The maximal density change and the maximal acoustic wave intensity in optical glasses of 5cm in thickness are calculated by using different parameters of the high-energy laser, such as the intensity, the pulse width, and the wave length. The damage threshold of the optical glasses is about 80 GW/cm^2 when using a 1064 nm laser. The dynamic mechanism of SBS is the electrostriction effect of the components coupling with the high-power laser.展开更多
We report on the performance improvement of long-wave infrared quantum cascade lasers(LWIR QCLs)by studying and optimizing the anti-reflection(AR)optical facet coating.Compared to the Al2O3 AR coat⁃ing,the Y_(2)O_(3)A...We report on the performance improvement of long-wave infrared quantum cascade lasers(LWIR QCLs)by studying and optimizing the anti-reflection(AR)optical facet coating.Compared to the Al2O3 AR coat⁃ing,the Y_(2)O_(3)AR coating exhibits higher catastrophic optical mirror damage(COMD)level,and the optical facet coatings of both material systems have no beam steering effect.A 3-mm-long,9.5-μm-wide buried-heterostruc⁃ture(BH)LWIR QCL ofλ~8.5μm with Y_(2)O_(3)metallic high-reflection(HR)and AR of~0.2%reflectivity coating demonstrates a maximum pulsed peak power of 2.19 W at 298 K,which is 149%higher than that of the uncoated device.For continuous-wave(CW)operation,by optimizing the reflectivity of the Y_(2)O_(3)AR coating,the maximum output power reaches 0.73 W,which is 91%higher than that of the uncoated device.展开更多
A novel coupled multi-active-region large optical cavity structure cascaded by a tunnel junction is proposed to solve the problems of facet catastrophic optical damage （COD） and the large vertical divergence caused ...A novel coupled multi-active-region large optical cavity structure cascaded by a tunnel junction is proposed to solve the problems of facet catastrophic optical damage （COD） and the large vertical divergence caused by the thin emitting area in conventional laser diodes. For a laser with three active regions, a slope efficiency as high as 1.49 W/A, a vertical divergence angle of 17.4~, and a threshold current density of 271 A/cm~ are achieved. By optimizing the structural parameters, the beam quMity is greatly improved, and the level of the COD power increases by more than two times compared with that of the conventional laser.展开更多
Rho-associated kinase (ROCK) is a serine/threonine kinase and one of the major downstream effectors of the small GTPase RhoA. The Rho/ROCK pathway is closely related to the pathogenesis of several central nervous syst...Rho-associated kinase (ROCK) is a serine/threonine kinase and one of the major downstream effectors of the small GTPase RhoA. The Rho/ROCK pathway is closely related to the pathogenesis of several central nervous system (CNS) disorders, and involved in many aspects of neuronal functions including neurite outgrowth and retraction. In the adult CNS, the damaged neuron regeneration is very difficult due to the presence of myelin-associated axon growth inhibitors such as Nogo, myelin-associated glycoprotein (MAG) and oligodendrocyte-myelin glycoprotein (Omgp), etc. The effects of these axon growth inhibitors are reversed by blocking the Rho/ROCK pathway 47 vitro, and the inhibition of Rho/ROCK pathway can promote axon regeneration and functional recovery in the injured CNS in viva In addition, the therapeutic effects of the Rho/ROCK inhibitors have also been demonstrated in some animal models and the Rho/ROCK pathway becomes an attractive target for the development of drugs for treating CNS disorders. In this review, we summarized on the effect of the Rho and the downstream factor ROCK in neural regeneration, and the potential therapeutic effect of Rho/ROCK inhibitors in the survival and axonal regeneration of retinal ganglion cell was also discussed.展开更多
Based on the diffraction theory model for hot-image formation, the evolution of hot-images induced by multiscatterers located in the same plane perpendicular to the propagation axis is numerically simulated. The simul...Based on the diffraction theory model for hot-image formation, the evolution of hot-images induced by multiscatterers located in the same plane perpendicular to the propagation axis is numerically simulated. The simulation results show that hot-images induced by coplanar multi-scatterers are also coplanar no matter whether they exist simultaneously or severally. However, if they exist simultaneously the peak intensity of the primary hot-images is weaker than if they exist severally. The unequal competition for energy between the scattered beams from the scatterers leads to the fact that part of the corresponding hot-images are relatively enhanced and the others are restrained. The results show that the hot-images of certain scatterers become stronger when any of these parameters, i.e. amplitude modulation coefficient, phase modulation coefficient and size of the surrounding scatterer, decrease.展开更多
Output power and reliability are the most important characteristic parameters of semiconductor lasers.However,catas-trophic optical damage(COD),which usually occurs on the cavity surface,will seriously damage the furt...Output power and reliability are the most important characteristic parameters of semiconductor lasers.However,catas-trophic optical damage(COD),which usually occurs on the cavity surface,will seriously damage the further improvement of the output power and affect the reliability.To improve the anti-optical disaster ability of the cavity surface,a non-absorption window(NAW)is adopted for the 915 nm InGaAsP/GaAsP single-quantum well semiconductor laser using quantum well mix-ing(QWI)induced by impurity-free vacancy.Both the principle and the process of point defect diffusion are described in detail in this paper.We also studied the effects of annealing temperature,annealing time,and the thickness of SiO_(2) film on the quan-tum well mixing in a semiconductor laser with a primary epitaxial structure,which is distinct from the previous structures.We found that when compared with the complete epitaxial structure,the blue shift of the semiconductor laser with the primary epi-taxial structure is larger under the same conditions.To obtain the appropriate blue shift window,the primary epitaxial struc-ture can use a lower annealing temperature and shorter annealing time.In addition,the process is less expensive.We also pro-vide references for upcoming device fabrication.展开更多
The optical catastrophic damage that usually occurs at the cavity surface of semiconductor lasers has become the main bottleneck affecting the improvement of laser output power and long-term reliability.To improve the...The optical catastrophic damage that usually occurs at the cavity surface of semiconductor lasers has become the main bottleneck affecting the improvement of laser output power and long-term reliability.To improve the output power of 680 nm AlGaInP/GaInP quantum well red semiconductor lasers,Si-Si_(3)N_(4)composited dielectric layers are used to induce its quantum wells to be intermixed at the cavity surface to make a non-absorption window.Si with a thickness of 100 nm and Si_(3)N_(4)with a thickness of 100 nm were grown on the surface of the epitaxial wafer by magnetron sputtering and PECVD as diffusion source and driving source,respectively.Compared with traditional Si impurity induced quantum well intermixing,this paper realizes the blue shift of 54.8 nm in the nonabsorbent window region at a lower annealing temperature of 600 ℃ and annealing time of 10 min.Under this annealing condition,the wavelength of the gain luminescence region basically does not shift to short wavelength,and the surface morphology of the whole epitaxial wafer remains fine after annealing.The application of this process condition can reduce the difficulty of production and save cost,which provides an effective method for upcoming fabrication.展开更多
The combination of deep wet etching and a magneto-rheological finishing （MRF） process is investigated to simultaneously improve laser damage resistance of a fused-silica surface at 355 nm. The subsequently deposited...The combination of deep wet etching and a magneto-rheological finishing （MRF） process is investigated to simultaneously improve laser damage resistance of a fused-silica surface at 355 nm. The subsequently deposited SiO2 coatings are researched to clarify the impact of substrate finishing technology on the coatings. It is revealed that a deep removal proceeding from the single side or double side had a significant impact on the laser-induced damage threshold （LIDT） of the fused silica, especially for the rear surface. After the deep etching, the MRF process that followed does not actually increase the LIDT, but it does ameliorate the surface qualities without additional LIDT degradation. The combination guarantee both the integrity of the surface＇s finish and the laser damage resistance of the fused silica and subsequent SiO2 coatings.展开更多
AIM:To investigate the effect of Bak Foong Pills(BFP) on the expression of β-amyloid(Aβ) in rats retina with optic nerve transaction,and its roles and possible mechanisms in protecting optic nerve damage.· METH...AIM:To investigate the effect of Bak Foong Pills(BFP) on the expression of β-amyloid(Aβ) in rats retina with optic nerve transaction,and its roles and possible mechanisms in protecting optic nerve damage.· METHODS:Seventy-two healthy,Sprague-Dawley,adult rats were randomly assigned to three groups:negative control group(control group),optic nerve transection group(model group) and BFP treatment group(BFP group,100μg/mL) followed by establishing optic nerve transection model.The expression of Aβ was measured at 48 hours by Western-blotting.Moreover,the expressions of Bcl-2,Bax and Caspase-3 mRNA were evaluated at 48 hours by reverse transcriptase polymerase chain reaction(RT-PCR).RESULTS:There were significant differences among the control,model and BFP groups in the expression of Aβ(all P <0.01).Aβ expression was significantly higher in the model and BFP groups than that in the control group(P < 0.01),with a more significant reduction in the BFP group than that in the model group(P <0.01).Moreover,there were also significant differences among the three groups in the expressions of Bcl-2/Bax(Bcl-2:anti-apoptotic;Bax:proapoptotic) and Caspase-3 mRNA(proapoptotic)(all P<0.01).Bcl-2/Bax ratio was significantly lower and Caspase-3 mRNA expression was significantly higher in the model and BFP groups than those in the control group(P <0.01),with a significant growing of Bcl-2/Bax and reduction of Caspase-3 in the BFP group than those in the model group(P<0.01).· CONCLUSION:BFP can down-regulate Aβ expression in retina and may inhibit apoptosis and protect optic nerve by enhancing Bcl-2/Bax ratio and inhibiting Caspase-3 pathway.展开更多
Based on network pharmacology,this study predicted the potential molecular mechanism and related pathways of the protective effect of traditional Chuanxiong Rhizoma,a traditional Chinese herb,on glaucomatous optic ner...Based on network pharmacology,this study predicted the potential molecular mechanism and related pathways of the protective effect of traditional Chuanxiong Rhizoma,a traditional Chinese herb,on glaucomatous optic nerve injury,and conducted in vitro experimental verification of the predicted results of network analysis.We analyzed the molecular mechanism of Chuanxiong Rhizoma in the potential treatment of glaucoma by revealing its main active ingredients and predicting its targets,so as to provide reference for subsequent basic research.Network pharmacological research results showed that the potential hub targets and key signaling pathways of Chuanxiong Rhizoma in the treatment of glaucoma were closely related to biological processes such as apoptosis,autophagy,inflammation,oxidative stress and angiogenesis.Molecular docking showed that many active ingredients,such as chrysophanol(CHR),myricanone and retinol,could combine well with their target proteins by intermolecular forces,especially CHR had strong binding ability with each target.We speculated that the main active component of Chuanxiong Rhizoma might be involved in the regulation of PI3K-Akt,Nod-like receptor,IL-4 and IL-13,MAPK,AGE-RAGE and neurotrophin signaling pathway by regulating of PI3K,Akt,TLR4,RAGE,NTRK2 and other key targets.Furthermore,it may achieve multi-directional intervention on apoptosis/autophagy,inflammation/immunity,oxidative stress and nutrient metabolism of axoplasma flow,and then delay the degeneration of optic nerve injury.In vitro experiments showed that the active component CHR of Chuanxiong Rhizoma could reverse the M1-type polarization and autophagy/apoptosis of mouse microglia(BV2)induced by lipopolysaccharide(LPS)at the transcriptional level.Meanwhile,the expression of inflammatory mediators IL-1βand TNF-αwas inhibited,and the mRNA level of anti-inflammatory factor IL-10 was significantly increased.In addition,CHR down-regulates activation of the RAGE-NOX4 pathway mediated by LPS in reducing oxidative stress.In this study,network pharmacology and molecular docking technology were integrated for the first time to explore the potential molecular mechanism of traditional Chinese herb“Chuanxiong Rhizoma”in the treatment on glaucoma,and CHR was innovatively proposed as an important ingredient in Chuanxiong Rhizoma that plays a protective role in the damage of optic nerve.Preliminary verification was conducted through in vitro experiments.The results suggest that Chuanxiong Rhizoma may interfere with autophagy and apoptosis,inhibit immune inflammation,as well as reduce oxidative stress in the treatment of glaucoma through the active components represented by CHR,so as to resist progressive optic nerve injury.Our study provides theoretical basis for the clinical use of Chinese herbal medicine or its extract in glaucoma,and also lays a solid foundation for the research of Chinese medicine in the field of optic nerve protection.展开更多
Enhanced acceleration of protons to high energy by relatively modest high power ultra-short laser pulses, interacting with snow micro-structured targets was recently proposed. A notably increased proton energy was att...Enhanced acceleration of protons to high energy by relatively modest high power ultra-short laser pulses, interacting with snow micro-structured targets was recently proposed. A notably increased proton energy was attributed to a combination of several mechanisms such as localized enhancement of the laser field intensity near the tip of 1 μm size whisker and increase in the hot electron concentration near the tip. Moreover, the use of mass-limited target prevents undesirable spread of absorbed laser energy out of the interaction zone. With increasing laser intensity a Coulomb explosion of the positively charged whisker will occur. All these mechanisms are functions of the local density profile and strongly depend on the laser pre-pulse structure. To clarify the effect of the pre-pulse on the state of the snow micro-structured target at the time of interaction with the main pulse, we measured the optical damage threshold(ODT) of the snow targets. ODT of 0.4 J/cm^2 was measured by irradiating snow micro-structured targets with 50 fs duration pulses of Ti:Sapphire laser.展开更多
In-situ laser-induced surface damage inspection plays a key role in protecting the large aperture optics in an inertial confinement fusion(ICF)high-power laser facility.In order to improve the initial damage detection...In-situ laser-induced surface damage inspection plays a key role in protecting the large aperture optics in an inertial confinement fusion(ICF)high-power laser facility.In order to improve the initial damage detection capabilities,an in-situ inspection method based on image super-resolution and adaptive segmentation method is presented.Through transfer learning and integration of various attention mechanisms,the super-resolution reconstruction of darkfield images with less texture information is effectively realized,and,on the basis of image super-resolution,an adaptive image segmentation method is designed,which effectively adapts to the damage detection problems under conditions of uneven illumination and weak signal.An online experiment was carried out by using edge illumination and the telescope optical imaging system,and the validity of the method was proved by the experimental results.展开更多
文摘AIM:To investigate the effects of adenosine triphosphate(ATP)and melatonin,which have antioxidant and antiinflammatory activities,on potential 5-fluorouracil(5-FU)-induced optic nerve damage in rats.METHODS:Twenty-four rats were categorized into four groups of six rats:healthy(HG),5-FU(FUG),ATP+5-FU(AFU),and melatonin+5-FU(MFU).ATP(4 mg/kg)and melatonin(10 mg/kg)were administered intraperitoneally and orally,respectively.One hour after ATP and melatonin administration,rats in the AFU,MFU,and FUG were intraperitoneally injected with 5-FU(100 mg/kg).ATP and melatonin were administered once daily for 10d.5-FU was administered at a single dose on days 1,3,and 5 of the experiment.After 10d,the rats were euthanized and optic nerve tissues were extracted.Optic nerve tissues were biochemically and histopathologically examined.RESULTS:ATP and melatonin treatments inhibited the increase in malondialdehyde(MDA)and interleukin-6(IL-6)levels,which were elevated in the FUG.The treatments also prevented the decrease in total glutathione(tGSH)levels and the superoxide dismutase(SOD)and catalase(CAT)activities(P<0.001).This inhibition was higher in the ATP group than in the melatonin group(P<0.001).ATP prevented histopathological damage better than melatonin(P<0.05).CONCLUSION:ATP and melatonin have the potential to be used in alleviating 5-FU-induced optic nerve damage.In addition,ATP treatment shows better protective effects than melatonin.
基金supported by the National Key Research and Development Program of China,No.2019YFA0111200the National Natural Science Foundation of China,Nos.U23A20436,82371047+3 种基金Key Research Project in Shanxi Province,No.202302130501008Shanxi Provincial Science Fund for Distinguished Young Scholars,No.202103021221008Key Research and Development Program in Shanxi Province,No.202204051001023Shanxi Medical University Doctor’s Startup Fund Project,No.SD22028(all to YG)。
文摘Retinal ganglion cells are the bridging neurons between the eye and the central nervous system,transmitting visual signals to the brain.The injury and loss of retinal ganglion cells are the primary pathological changes in several retinal degenerative diseases,including glaucoma,ischemic optic neuropathy,diabetic neuropathy,and optic neuritis.In mammals,injured retinal ganglion cells lack regenerative capacity and undergo apoptotic cell death within a few days of injury.Additionally,these cells exhibit limited regenerative ability,ultimately contributing to vision impairment and potentially leading to blindness.Currently,the only effective clinical treatment for glaucoma is to prevent vision loss by lowering intraocular pressure through medications or surgery;however,this approach cannot halt the effect of retinal ganglion cell loss on visual function.This review comprehensively investigates the mechanisms underlying retinal ganglion cell degeneration in retinal degenerative diseases and further explores the current status and potential of cell replacement therapy for regenerating retinal ganglion cells.As our understanding of the complex processes involved in retinal ganglion cell degeneration deepens,we can explore new treatment strategies,such as cell transplantation,which may offer more effective ways to mitigate the effect of retinal degenerative diseases on vision.
基金Project supported by the joint fund of the National Natural Science Foundation of China and the China Academy of Engineering Physics （Grant No 10076004）.
文摘A theory of excitation of ultrasonic waves in the stimulated Brillouin scattering （SBS） process is presented in this paper. By using several reasonable approximations, a numerical calculation of the transient longitudinal SBS shows that large amplitude of acoustic waves can be built up by the nanosecond pulse of high-power laser, which may result in the damage of optical glasses. The maximal density change and the maximal acoustic wave intensity in optical glasses of 5cm in thickness are calculated by using different parameters of the high-energy laser, such as the intensity, the pulse width, and the wave length. The damage threshold of the optical glasses is about 80 GW/cm^2 when using a 1064 nm laser. The dynamic mechanism of SBS is the electrostriction effect of the components coupling with the high-power laser.
基金Supported by the National Natural Science Foundation of China(12393830)。
文摘We report on the performance improvement of long-wave infrared quantum cascade lasers(LWIR QCLs)by studying and optimizing the anti-reflection(AR)optical facet coating.Compared to the Al2O3 AR coat⁃ing,the Y_(2)O_(3)AR coating exhibits higher catastrophic optical mirror damage(COMD)level,and the optical facet coatings of both material systems have no beam steering effect.A 3-mm-long,9.5-μm-wide buried-heterostruc⁃ture(BH)LWIR QCL ofλ~8.5μm with Y_(2)O_(3)metallic high-reflection(HR)and AR of~0.2%reflectivity coating demonstrates a maximum pulsed peak power of 2.19 W at 298 K,which is 149%higher than that of the uncoated device.For continuous-wave(CW)operation,by optimizing the reflectivity of the Y_(2)O_(3)AR coating,the maximum output power reaches 0.73 W,which is 91%higher than that of the uncoated device.
基金Project supported by the State Key Development Program for Basic Research of China (Grant No. G20000863-02)the Natural Science Foundation of Beijing, China (Grant No. 4032007)
文摘A novel coupled multi-active-region large optical cavity structure cascaded by a tunnel junction is proposed to solve the problems of facet catastrophic optical damage （COD） and the large vertical divergence caused by the thin emitting area in conventional laser diodes. For a laser with three active regions, a slope efficiency as high as 1.49 W/A, a vertical divergence angle of 17.4~, and a threshold current density of 271 A/cm~ are achieved. By optimizing the structural parameters, the beam quMity is greatly improved, and the level of the COD power increases by more than two times compared with that of the conventional laser.
基金Supported by National Nature Science Foundation of China (No.81070728)Shanghai "Science and Technology Innovation Action Plan" Basic Research Key Project,China (No.11JC1407700 and 11 JC1407701)+1 种基金Shanghai Nature Science Foundation, China (No.08ZR1413900)Shanghai Leading Academic Discipline Project, China(No.S30205)
文摘Rho-associated kinase (ROCK) is a serine/threonine kinase and one of the major downstream effectors of the small GTPase RhoA. The Rho/ROCK pathway is closely related to the pathogenesis of several central nervous system (CNS) disorders, and involved in many aspects of neuronal functions including neurite outgrowth and retraction. In the adult CNS, the damaged neuron regeneration is very difficult due to the presence of myelin-associated axon growth inhibitors such as Nogo, myelin-associated glycoprotein (MAG) and oligodendrocyte-myelin glycoprotein (Omgp), etc. The effects of these axon growth inhibitors are reversed by blocking the Rho/ROCK pathway 47 vitro, and the inhibition of Rho/ROCK pathway can promote axon regeneration and functional recovery in the injured CNS in viva In addition, the therapeutic effects of the Rho/ROCK inhibitors have also been demonstrated in some animal models and the Rho/ROCK pathway becomes an attractive target for the development of drugs for treating CNS disorders. In this review, we summarized on the effect of the Rho and the downstream factor ROCK in neural regeneration, and the potential therapeutic effect of Rho/ROCK inhibitors in the survival and axonal regeneration of retinal ganglion cell was also discussed.
基金supported by the Joint Foundation of National Natural Science Foundation of China and the Science Foundation of the Chinese Academy of Engineering Physics,China(Grant No 10576023)the Doctorate Foundation of Northwestern Polytechnical University,China(Grant No CX200714)
文摘Based on the diffraction theory model for hot-image formation, the evolution of hot-images induced by multiscatterers located in the same plane perpendicular to the propagation axis is numerically simulated. The simulation results show that hot-images induced by coplanar multi-scatterers are also coplanar no matter whether they exist simultaneously or severally. However, if they exist simultaneously the peak intensity of the primary hot-images is weaker than if they exist severally. The unequal competition for energy between the scattered beams from the scatterers leads to the fact that part of the corresponding hot-images are relatively enhanced and the others are restrained. The results show that the hot-images of certain scatterers become stronger when any of these parameters, i.e. amplitude modulation coefficient, phase modulation coefficient and size of the surrounding scatterer, decrease.
基金This work was supported by the National Natural Science Foundation of China(NNSFC)(Grant No.62174154).
文摘Output power and reliability are the most important characteristic parameters of semiconductor lasers.However,catas-trophic optical damage(COD),which usually occurs on the cavity surface,will seriously damage the further improvement of the output power and affect the reliability.To improve the anti-optical disaster ability of the cavity surface,a non-absorption window(NAW)is adopted for the 915 nm InGaAsP/GaAsP single-quantum well semiconductor laser using quantum well mix-ing(QWI)induced by impurity-free vacancy.Both the principle and the process of point defect diffusion are described in detail in this paper.We also studied the effects of annealing temperature,annealing time,and the thickness of SiO_(2) film on the quan-tum well mixing in a semiconductor laser with a primary epitaxial structure,which is distinct from the previous structures.We found that when compared with the complete epitaxial structure,the blue shift of the semiconductor laser with the primary epi-taxial structure is larger under the same conditions.To obtain the appropriate blue shift window,the primary epitaxial struc-ture can use a lower annealing temperature and shorter annealing time.In addition,the process is less expensive.We also pro-vide references for upcoming device fabrication.
基金supported by the National Natural Science Foundation of China(NNSFC)(Grant No.62174154).
文摘The optical catastrophic damage that usually occurs at the cavity surface of semiconductor lasers has become the main bottleneck affecting the improvement of laser output power and long-term reliability.To improve the output power of 680 nm AlGaInP/GaInP quantum well red semiconductor lasers,Si-Si_(3)N_(4)composited dielectric layers are used to induce its quantum wells to be intermixed at the cavity surface to make a non-absorption window.Si with a thickness of 100 nm and Si_(3)N_(4)with a thickness of 100 nm were grown on the surface of the epitaxial wafer by magnetron sputtering and PECVD as diffusion source and driving source,respectively.Compared with traditional Si impurity induced quantum well intermixing,this paper realizes the blue shift of 54.8 nm in the nonabsorbent window region at a lower annealing temperature of 600 ℃ and annealing time of 10 min.Under this annealing condition,the wavelength of the gain luminescence region basically does not shift to short wavelength,and the surface morphology of the whole epitaxial wafer remains fine after annealing.The application of this process condition can reduce the difficulty of production and save cost,which provides an effective method for upcoming fabrication.
基金supported by the National Natural Science Foundation of China under Grant Nos.11104293 and 61308021
文摘The combination of deep wet etching and a magneto-rheological finishing （MRF） process is investigated to simultaneously improve laser damage resistance of a fused-silica surface at 355 nm. The subsequently deposited SiO2 coatings are researched to clarify the impact of substrate finishing technology on the coatings. It is revealed that a deep removal proceeding from the single side or double side had a significant impact on the laser-induced damage threshold （LIDT） of the fused silica, especially for the rear surface. After the deep etching, the MRF process that followed does not actually increase the LIDT, but it does ameliorate the surface qualities without additional LIDT degradation. The combination guarantee both the integrity of the surface＇s finish and the laser damage resistance of the fused silica and subsequent SiO2 coatings.
文摘AIM:To investigate the effect of Bak Foong Pills(BFP) on the expression of β-amyloid(Aβ) in rats retina with optic nerve transaction,and its roles and possible mechanisms in protecting optic nerve damage.· METHODS:Seventy-two healthy,Sprague-Dawley,adult rats were randomly assigned to three groups:negative control group(control group),optic nerve transection group(model group) and BFP treatment group(BFP group,100μg/mL) followed by establishing optic nerve transection model.The expression of Aβ was measured at 48 hours by Western-blotting.Moreover,the expressions of Bcl-2,Bax and Caspase-3 mRNA were evaluated at 48 hours by reverse transcriptase polymerase chain reaction(RT-PCR).RESULTS:There were significant differences among the control,model and BFP groups in the expression of Aβ(all P <0.01).Aβ expression was significantly higher in the model and BFP groups than that in the control group(P < 0.01),with a more significant reduction in the BFP group than that in the model group(P <0.01).Moreover,there were also significant differences among the three groups in the expressions of Bcl-2/Bax(Bcl-2:anti-apoptotic;Bax:proapoptotic) and Caspase-3 mRNA(proapoptotic)(all P<0.01).Bcl-2/Bax ratio was significantly lower and Caspase-3 mRNA expression was significantly higher in the model and BFP groups than those in the control group(P <0.01),with a significant growing of Bcl-2/Bax and reduction of Caspase-3 in the BFP group than those in the model group(P<0.01).· CONCLUSION:BFP can down-regulate Aβ expression in retina and may inhibit apoptosis and protect optic nerve by enhancing Bcl-2/Bax ratio and inhibiting Caspase-3 pathway.
基金National Natural Science Foundation of China(No.81704123)Science and Technology Program of Guangzhou(No.2023A03J0774).
文摘Based on network pharmacology,this study predicted the potential molecular mechanism and related pathways of the protective effect of traditional Chuanxiong Rhizoma,a traditional Chinese herb,on glaucomatous optic nerve injury,and conducted in vitro experimental verification of the predicted results of network analysis.We analyzed the molecular mechanism of Chuanxiong Rhizoma in the potential treatment of glaucoma by revealing its main active ingredients and predicting its targets,so as to provide reference for subsequent basic research.Network pharmacological research results showed that the potential hub targets and key signaling pathways of Chuanxiong Rhizoma in the treatment of glaucoma were closely related to biological processes such as apoptosis,autophagy,inflammation,oxidative stress and angiogenesis.Molecular docking showed that many active ingredients,such as chrysophanol(CHR),myricanone and retinol,could combine well with their target proteins by intermolecular forces,especially CHR had strong binding ability with each target.We speculated that the main active component of Chuanxiong Rhizoma might be involved in the regulation of PI3K-Akt,Nod-like receptor,IL-4 and IL-13,MAPK,AGE-RAGE and neurotrophin signaling pathway by regulating of PI3K,Akt,TLR4,RAGE,NTRK2 and other key targets.Furthermore,it may achieve multi-directional intervention on apoptosis/autophagy,inflammation/immunity,oxidative stress and nutrient metabolism of axoplasma flow,and then delay the degeneration of optic nerve injury.In vitro experiments showed that the active component CHR of Chuanxiong Rhizoma could reverse the M1-type polarization and autophagy/apoptosis of mouse microglia(BV2)induced by lipopolysaccharide(LPS)at the transcriptional level.Meanwhile,the expression of inflammatory mediators IL-1βand TNF-αwas inhibited,and the mRNA level of anti-inflammatory factor IL-10 was significantly increased.In addition,CHR down-regulates activation of the RAGE-NOX4 pathway mediated by LPS in reducing oxidative stress.In this study,network pharmacology and molecular docking technology were integrated for the first time to explore the potential molecular mechanism of traditional Chinese herb“Chuanxiong Rhizoma”in the treatment on glaucoma,and CHR was innovatively proposed as an important ingredient in Chuanxiong Rhizoma that plays a protective role in the damage of optic nerve.Preliminary verification was conducted through in vitro experiments.The results suggest that Chuanxiong Rhizoma may interfere with autophagy and apoptosis,inhibit immune inflammation,as well as reduce oxidative stress in the treatment of glaucoma through the active components represented by CHR,so as to resist progressive optic nerve injury.Our study provides theoretical basis for the clinical use of Chinese herbal medicine or its extract in glaucoma,and also lays a solid foundation for the research of Chinese medicine in the field of optic nerve protection.
文摘Enhanced acceleration of protons to high energy by relatively modest high power ultra-short laser pulses, interacting with snow micro-structured targets was recently proposed. A notably increased proton energy was attributed to a combination of several mechanisms such as localized enhancement of the laser field intensity near the tip of 1 μm size whisker and increase in the hot electron concentration near the tip. Moreover, the use of mass-limited target prevents undesirable spread of absorbed laser energy out of the interaction zone. With increasing laser intensity a Coulomb explosion of the positively charged whisker will occur. All these mechanisms are functions of the local density profile and strongly depend on the laser pre-pulse structure. To clarify the effect of the pre-pulse on the state of the snow micro-structured target at the time of interaction with the main pulse, we measured the optical damage threshold(ODT) of the snow targets. ODT of 0.4 J/cm^2 was measured by irradiating snow micro-structured targets with 50 fs duration pulses of Ti:Sapphire laser.
文摘In-situ laser-induced surface damage inspection plays a key role in protecting the large aperture optics in an inertial confinement fusion(ICF)high-power laser facility.In order to improve the initial damage detection capabilities,an in-situ inspection method based on image super-resolution and adaptive segmentation method is presented.Through transfer learning and integration of various attention mechanisms,the super-resolution reconstruction of darkfield images with less texture information is effectively realized,and,on the basis of image super-resolution,an adaptive image segmentation method is designed,which effectively adapts to the damage detection problems under conditions of uneven illumination and weak signal.An online experiment was carried out by using edge illumination and the telescope optical imaging system,and the validity of the method was proved by the experimental results.
