Oxidative stress is caused by an imbalance of the antioxidant defense system and excessive production of free radicals,which can damage biological macromolecules such as proteins,lipids and nucleic acids,and can cause...Oxidative stress is caused by an imbalance of the antioxidant defense system and excessive production of free radicals,which can damage biological macromolecules such as proteins,lipids and nucleic acids,and can cause aging,ischemia-reperfusion injury,inflammatory injury,liver and kidney injury and other diseases.The nuclear factor erytheroid-2-related factor 2(Nrf2)is a major regulator of redox balance.The Nrf2 pathway also exerts a central function in cell apoptosis,oxidative stress damage and metabolic diseases.Bioactive peptides are small molecular peptides composed of amino acid residues.They have many biological activities and play important physiological roles in human body.Antioxidant peptide is a kind of peptide which can reduce oxidative stress damage.They are safe,non-toxic and easily absorbed.In this review,we summarized the mechanism of bioactive peptides in regulating oxidative stress,especially antioxidant peptides,through regulating the Nrf2 signaling pathway and the expressions of oxidative stress-related genes,to alleviate oxidative stress-induced damage.The paper will provide valuable reference to investigators in the antioxidant peptide field and also promote the applications of antioxidant peptides in the oxidative stress-associated diseases.展开更多
Acute myocardial infarction(MI)remains one of the leading causes of mortality and morbidity in the global communities.A prevailing topic that has attracted increasing attentions over the past few decades is the so-cal...Acute myocardial infarction(MI)remains one of the leading causes of mortality and morbidity in the global communities.A prevailing topic that has attracted increasing attentions over the past few decades is the so-called heart-brain interaction,in particular following a major traumatic event such as MI.Increased prevalence of depression and other mental disorders has been recognized in cardiac patients after MI,coronary catheterization,or cardiothoracic surgeries.In this review,we focus on the potential pathogenic mechanisms and pre-clinical transcriptomic evidence for identifying potential mediators of post-MI depression.We first summarize the conventional mechanistic understanding that leads to the current clinical management of post-MI depression with the use of selective serotonin reuptake inhibitors(SSRIs)and cognitive behavior and exercise therapies.We further envisage a possible role played by certain chemokines,e.g.,Chemokine(C-X-C motif)ligand 12(CXCL12)and Chemokine(C-C motif)ligand 2(CCL22),in serving as signaling molecules to connect the MI-induced heart damage to the pro-depressive changes in brain during the post-MI period.Future in-depth investigations into this chemokine hypothesis will be instrumental in developing new chemokine-targeted therapies for better management of the cardiac patients suffering from post-MI depression.展开更多
Suppression of stimulated Raman scattering(SRS)by means of chirped and tilted fiber Bragg gratings(CTFBGs)has become a key topic.However,research on high-power systems is still lacking due to two problems.Firstly,afte...Suppression of stimulated Raman scattering(SRS)by means of chirped and tilted fiber Bragg gratings(CTFBGs)has become a key topic.However,research on high-power systems is still lacking due to two problems.Firstly,after the inscription,there are a large number of hydroxyl compounds and hydrogen molecules in CTFBGs that cause significant heating due to their strong infrared absorption.Secondly,CTFBGs can couple Stokes light from the core to the cladding and the coating,which causes serious heating in the coating of the CTFBG.Aimed at overcoming these bottlenecks,a process that combines constant-low-temperature and variable-high-temperature annealing is used to reduce the thermal slope of the CTFBG.Also,a segmented-corrosion cladding power stripping technology is used on the CTFBG to remove the Stokes light which is coupled to the cladding,which solves the problem of overheating in the coating of the CTFBG.Thereby,a CTFBG with both a kilowatt-level power-carrying load and the ability to suppress SRS in a fiber laser has been developed.Further,we establish a kW-level CW oscillator to test the CTFBG.Experimental results demonstrate that the power-carrying load of the CTFBG is close to 1 kW,the thermal slope is lower than 0.015 ℃/W,and the SRS suppression ratio is nearly 23 dB.展开更多
Suppressing nonlinear effects in high-power fiber lasers based on fiber gratings has become a hotspot.At present,research is mainly focused on suppressing stimulated Raman scattering in a high-power fiber laser.Howeve...Suppressing nonlinear effects in high-power fiber lasers based on fiber gratings has become a hotspot.At present,research is mainly focused on suppressing stimulated Raman scattering in a high-power fiber laser.However,the suppression of spectral broadening,caused by self-phase modulation or four-wave mixing,is still a challenging attribute to the close distance between the broadened laser and signal laser.If using a traditional fiber grating with only one stopband to suppress the spectral broadening,the signal power will be stripped simultaneously.Confronting this challenge,we propose a novel method based on phase-shifted long-period fiber grating(PS-LPFG)to suppress spectral broadening in a high-power fiber master oscillator power amplifier(MOPA)laser system in this paper.A PS-LPFG is designed and fabricated on 10/130 passive fiber utilizing a point-by-point scanning technique.The resonant wavelength of the fabricated PS-LPFG is 1080 nm,the full width at half maximum of the passband is 5.48 nm,and stopband extinction exceeds 90%.To evaluate the performance of the PS-LPFG,the grating is inserted into the seed of a kilowattlevel continuous-wave MOPA system.Experiment results show that the 30 dB linewidth of the output spectrum is narrowed by approximately 37.97%,providing an effective and flexible way for optimizing the output linewidth of highpower fiber MOPA laser systems.展开更多
基金the funds from the National Key R&D Program of China(2022YFF1100200).
文摘Oxidative stress is caused by an imbalance of the antioxidant defense system and excessive production of free radicals,which can damage biological macromolecules such as proteins,lipids and nucleic acids,and can cause aging,ischemia-reperfusion injury,inflammatory injury,liver and kidney injury and other diseases.The nuclear factor erytheroid-2-related factor 2(Nrf2)is a major regulator of redox balance.The Nrf2 pathway also exerts a central function in cell apoptosis,oxidative stress damage and metabolic diseases.Bioactive peptides are small molecular peptides composed of amino acid residues.They have many biological activities and play important physiological roles in human body.Antioxidant peptide is a kind of peptide which can reduce oxidative stress damage.They are safe,non-toxic and easily absorbed.In this review,we summarized the mechanism of bioactive peptides in regulating oxidative stress,especially antioxidant peptides,through regulating the Nrf2 signaling pathway and the expressions of oxidative stress-related genes,to alleviate oxidative stress-induced damage.The paper will provide valuable reference to investigators in the antioxidant peptide field and also promote the applications of antioxidant peptides in the oxidative stress-associated diseases.
文摘Acute myocardial infarction(MI)remains one of the leading causes of mortality and morbidity in the global communities.A prevailing topic that has attracted increasing attentions over the past few decades is the so-called heart-brain interaction,in particular following a major traumatic event such as MI.Increased prevalence of depression and other mental disorders has been recognized in cardiac patients after MI,coronary catheterization,or cardiothoracic surgeries.In this review,we focus on the potential pathogenic mechanisms and pre-clinical transcriptomic evidence for identifying potential mediators of post-MI depression.We first summarize the conventional mechanistic understanding that leads to the current clinical management of post-MI depression with the use of selective serotonin reuptake inhibitors(SSRIs)and cognitive behavior and exercise therapies.We further envisage a possible role played by certain chemokines,e.g.,Chemokine(C-X-C motif)ligand 12(CXCL12)and Chemokine(C-C motif)ligand 2(CCL22),in serving as signaling molecules to connect the MI-induced heart damage to the pro-depressive changes in brain during the post-MI period.Future in-depth investigations into this chemokine hypothesis will be instrumental in developing new chemokine-targeted therapies for better management of the cardiac patients suffering from post-MI depression.
基金supported by the National Key Research and Development Program of China(No.2017YFB1104400)
文摘Suppression of stimulated Raman scattering(SRS)by means of chirped and tilted fiber Bragg gratings(CTFBGs)has become a key topic.However,research on high-power systems is still lacking due to two problems.Firstly,after the inscription,there are a large number of hydroxyl compounds and hydrogen molecules in CTFBGs that cause significant heating due to their strong infrared absorption.Secondly,CTFBGs can couple Stokes light from the core to the cladding and the coating,which causes serious heating in the coating of the CTFBG.Aimed at overcoming these bottlenecks,a process that combines constant-low-temperature and variable-high-temperature annealing is used to reduce the thermal slope of the CTFBG.Also,a segmented-corrosion cladding power stripping technology is used on the CTFBG to remove the Stokes light which is coupled to the cladding,which solves the problem of overheating in the coating of the CTFBG.Thereby,a CTFBG with both a kilowatt-level power-carrying load and the ability to suppress SRS in a fiber laser has been developed.Further,we establish a kW-level CW oscillator to test the CTFBG.Experimental results demonstrate that the power-carrying load of the CTFBG is close to 1 kW,the thermal slope is lower than 0.015 ℃/W,and the SRS suppression ratio is nearly 23 dB.
基金supported by the National Key Research and Development Program of China(No.2017YFB1104402)the Pre-research Foundation of Equipment Development Department(No.61404140105)+3 种基金the Key Laboratory of Optical System Advanced Manufacturing Technology of the Chinese Academy of Sciences(No.KLOMT190101)the Jiangsu Provincial Key Research and Development Program(No.BE2019114)the Basic Research Program of Jiangsu Province(No.BK20190456)the National Natural Science Foundation of China(No.62005120)。
文摘Suppressing nonlinear effects in high-power fiber lasers based on fiber gratings has become a hotspot.At present,research is mainly focused on suppressing stimulated Raman scattering in a high-power fiber laser.However,the suppression of spectral broadening,caused by self-phase modulation or four-wave mixing,is still a challenging attribute to the close distance between the broadened laser and signal laser.If using a traditional fiber grating with only one stopband to suppress the spectral broadening,the signal power will be stripped simultaneously.Confronting this challenge,we propose a novel method based on phase-shifted long-period fiber grating(PS-LPFG)to suppress spectral broadening in a high-power fiber master oscillator power amplifier(MOPA)laser system in this paper.A PS-LPFG is designed and fabricated on 10/130 passive fiber utilizing a point-by-point scanning technique.The resonant wavelength of the fabricated PS-LPFG is 1080 nm,the full width at half maximum of the passband is 5.48 nm,and stopband extinction exceeds 90%.To evaluate the performance of the PS-LPFG,the grating is inserted into the seed of a kilowattlevel continuous-wave MOPA system.Experiment results show that the 30 dB linewidth of the output spectrum is narrowed by approximately 37.97%,providing an effective and flexible way for optimizing the output linewidth of highpower fiber MOPA laser systems.
