Nicotinamide adenine dinucleotide(NAD)is one of the most important metabolites in mammalian cells(Figure 1 A).Its oxidized form(NAD+)and reduced form(NADH)play a role in many reactions within cells,most prominently in...Nicotinamide adenine dinucleotide(NAD)is one of the most important metabolites in mammalian cells(Figure 1 A).Its oxidized form(NAD+)and reduced form(NADH)play a role in many reactions within cells,most prominently in the redox reactions that lead to the production of ATP.NAD functions more broadly than that。展开更多
Background:The so-called macular carotenoids(MC)lutein(L),zeaxanthin(Z),and meso-zeaxanthin(MZ)comprise the diet-derived macular pigment(MP).The purpose of this study was to determine effects of MC supplementation on ...Background:The so-called macular carotenoids(MC)lutein(L),zeaxanthin(Z),and meso-zeaxanthin(MZ)comprise the diet-derived macular pigment(MP).The purpose of this study was to determine effects of MC supplementation on the optical density of MP(MPOD),repeated-exposure photostress recovery(PSR),and disability glare(DG)thresholds.Methods:This was a double-blind,placebo-controlled trial.Fifty-nine young(mean age=21.7),healthy volunteers participated in this study.Subjects supplemented their daily diet with either 10 mg L+2 mg total Z(1 mg Z+1 mg MZ;n=24),20 mg L+4 mg total Z(2 mg Z+2 mg MZ;n=25),or placebo(n=10)for 12 months.The primary outcome was a composite measure of visual performance in glare,defined by change in DG and PSR.Secondary outcomes included MPOD and visual fatigue.The primary endpoint for outcomes was 12 months.MPOD was assessed with customized heterochromatic flicker photometry.PSR times for an 8 cycle/degree,15%contrast Gabor patch target were determined after each of five successive exposures to intense LED lights.DG threshold was defined as the intensity of a ring of lights through which subjects were able to maintain visibility of the aforementioned target.Measures of all parameters were conducted at baseline,6 months,and 12 months.Repeated-measures ANOVA,and Pearson product-moment correlations were used to determine statistically significant correlations,and changes within and between groups.Results:MPOD for subjects in both supplementation groups increased significantly versus placebo at both 6-and 12-month visits(p<0.001 for all).Additionally,PSR times and DG thresholds improved significantly from baseline compared to placebo at 6-and 12-month visits(p<0.001 for all).At baseline,MPOD was significantly related to both DG thresholds(r=0.444;p=0.0021)and PSR times(r=-0.56;p<0.001).As a function of MPOD,the repeated-exposure PSR curves became more asymptotic,as opposed to linear.The change in subjects’DG thresholds were significantly related to changes in PSR times across the study period(r=-0.534;p<0.001).Conclusions:Increases in MPOD lead to significant improvements in PSR times and DG thresholds.The asymptotic shape of the repeated-exposure PSR curves suggests that increases in MPOD produce more consistent steady-state visual performance in bright light conditions.The mechanism for this effect may involve both the optical filtering and biochemical(antioxidant)properties of MP.Trial registration:ISRCTN trial registration number:ISRCTN54990825.Data reported in this manuscript represent secondary outcome measures from the registered trial.展开更多
For survival,bats of the suborder Microchiropetra emit intense ultrasonic pulses and analyze the weak returning echoes to extract the direction,distance,velocity,size,and shape of the prey.Although these bats and othe...For survival,bats of the suborder Microchiropetra emit intense ultrasonic pulses and analyze the weak returning echoes to extract the direction,distance,velocity,size,and shape of the prey.Although these bats and other mammals share the common layout of the auditory pathway and sound coding mechanism,they have highly developed auditory systems to process biologically relevant pulses at the expense of a reduced visual system.During this active biosonar behavior,they progressively shorten the pulse duration,decrease the amplitude and pulse-echo gap as they search,approach and finally intercept the prey.Presumably,these changes in multiple pulse parameters throughout the entire course of hunting enable them to extract maximal information about localized prey from the returning echoes.To hunt successfully,the auditory system of these bats must be less sensitive to intense emitted pulses but highly sensitive to weak returning echoes.They also need to recognize and differentiate the echoes of their emitted pulses from echoes of pulses emitted by other conspecifics.Past studies have shown the following mechanical and neural adaptive mechanisms underlying the successful bat biosonar behavior:(1)Forward orienting and highly mobile pinnae for effective scanning,signal reception,sound pressure transformation and mobile auditory sensitivity;(2)Avoiding and detecting moving targets more successfully than stationary ones;(3)Coordinated activity of highly developed laryngeal and middle ear muscles during pulse emission and reception;(4)Mechanical and neural attenuation of intense emitted pulses to prepare for better reception of weak returning echoes;(5)Increasing pulse repetition rate to improve multiple-parametric selectivity to echoes;(6)Dynamic variation of duration selectivity and recovery cycle of auditory neurons with hunting phase for better echo analysis;(7)Maximal multiple-parametric selectivity to expected echoes returning within a time window after pulse emission;(8)Pulse-echo delaysensitive neurons in higher auditory centers for echo ranging;(9)Corticofugal modulation to improve on-going multiple-parametric signal processing and reorganize signal representation,and(10)A large area of the superior colliculus,pontine nuclei and cerebellum that is sensitive to sound for sensori-motor integration.All these adaptive mechanisms facilitate the bat to effectively extract prey features for successful hunting.展开更多
基金the National Institute of Health grants R01NS069726 and R01NS094539the America Heart Association grants 13GRANT17020004 and 16IRG27780023 to SD。
文摘Nicotinamide adenine dinucleotide(NAD)is one of the most important metabolites in mammalian cells(Figure 1 A).Its oxidized form(NAD+)and reduced form(NADH)play a role in many reactions within cells,most prominently in the redox reactions that lead to the production of ATP.NAD functions more broadly than that。
基金This study was funded by Omniactive Health Technologies,Inc.,who had no role in study design,data collection,or analysis.
文摘Background:The so-called macular carotenoids(MC)lutein(L),zeaxanthin(Z),and meso-zeaxanthin(MZ)comprise the diet-derived macular pigment(MP).The purpose of this study was to determine effects of MC supplementation on the optical density of MP(MPOD),repeated-exposure photostress recovery(PSR),and disability glare(DG)thresholds.Methods:This was a double-blind,placebo-controlled trial.Fifty-nine young(mean age=21.7),healthy volunteers participated in this study.Subjects supplemented their daily diet with either 10 mg L+2 mg total Z(1 mg Z+1 mg MZ;n=24),20 mg L+4 mg total Z(2 mg Z+2 mg MZ;n=25),or placebo(n=10)for 12 months.The primary outcome was a composite measure of visual performance in glare,defined by change in DG and PSR.Secondary outcomes included MPOD and visual fatigue.The primary endpoint for outcomes was 12 months.MPOD was assessed with customized heterochromatic flicker photometry.PSR times for an 8 cycle/degree,15%contrast Gabor patch target were determined after each of five successive exposures to intense LED lights.DG threshold was defined as the intensity of a ring of lights through which subjects were able to maintain visibility of the aforementioned target.Measures of all parameters were conducted at baseline,6 months,and 12 months.Repeated-measures ANOVA,and Pearson product-moment correlations were used to determine statistically significant correlations,and changes within and between groups.Results:MPOD for subjects in both supplementation groups increased significantly versus placebo at both 6-and 12-month visits(p<0.001 for all).Additionally,PSR times and DG thresholds improved significantly from baseline compared to placebo at 6-and 12-month visits(p<0.001 for all).At baseline,MPOD was significantly related to both DG thresholds(r=0.444;p=0.0021)and PSR times(r=-0.56;p<0.001).As a function of MPOD,the repeated-exposure PSR curves became more asymptotic,as opposed to linear.The change in subjects’DG thresholds were significantly related to changes in PSR times across the study period(r=-0.534;p<0.001).Conclusions:Increases in MPOD lead to significant improvements in PSR times and DG thresholds.The asymptotic shape of the repeated-exposure PSR curves suggests that increases in MPOD produce more consistent steady-state visual performance in bright light conditions.The mechanism for this effect may involve both the optical filtering and biochemical(antioxidant)properties of MP.Trial registration:ISRCTN trial registration number:ISRCTN54990825.Data reported in this manuscript represent secondary outcome measures from the registered trial.
文摘For survival,bats of the suborder Microchiropetra emit intense ultrasonic pulses and analyze the weak returning echoes to extract the direction,distance,velocity,size,and shape of the prey.Although these bats and other mammals share the common layout of the auditory pathway and sound coding mechanism,they have highly developed auditory systems to process biologically relevant pulses at the expense of a reduced visual system.During this active biosonar behavior,they progressively shorten the pulse duration,decrease the amplitude and pulse-echo gap as they search,approach and finally intercept the prey.Presumably,these changes in multiple pulse parameters throughout the entire course of hunting enable them to extract maximal information about localized prey from the returning echoes.To hunt successfully,the auditory system of these bats must be less sensitive to intense emitted pulses but highly sensitive to weak returning echoes.They also need to recognize and differentiate the echoes of their emitted pulses from echoes of pulses emitted by other conspecifics.Past studies have shown the following mechanical and neural adaptive mechanisms underlying the successful bat biosonar behavior:(1)Forward orienting and highly mobile pinnae for effective scanning,signal reception,sound pressure transformation and mobile auditory sensitivity;(2)Avoiding and detecting moving targets more successfully than stationary ones;(3)Coordinated activity of highly developed laryngeal and middle ear muscles during pulse emission and reception;(4)Mechanical and neural attenuation of intense emitted pulses to prepare for better reception of weak returning echoes;(5)Increasing pulse repetition rate to improve multiple-parametric selectivity to echoes;(6)Dynamic variation of duration selectivity and recovery cycle of auditory neurons with hunting phase for better echo analysis;(7)Maximal multiple-parametric selectivity to expected echoes returning within a time window after pulse emission;(8)Pulse-echo delaysensitive neurons in higher auditory centers for echo ranging;(9)Corticofugal modulation to improve on-going multiple-parametric signal processing and reorganize signal representation,and(10)A large area of the superior colliculus,pontine nuclei and cerebellum that is sensitive to sound for sensori-motor integration.All these adaptive mechanisms facilitate the bat to effectively extract prey features for successful hunting.
