No abstract

Heterogeneous neurological responses of acupuncture between different groups have been proposed by previous studies but rarely studied. The study described here was designed to explore the divergence of acupuncture at Taixi (KI3) on spontaneous activity of brain regions and functional connectivity (FC) between healthy youth and elder with functional magnetic resonance imaging (fMRI). 20 healthy young volunteers and 20 healthy elders underwent 10-minute-resting-state fMRI before acupuncture, and then acupuncture at Taixi (KI3) for 3 minutes; after withdrawing the needles, volunteers underwent a second fMRI scan for 10 minutes. Regional homogeneity (ReHo) and large-scale FC analysis using Power 264 atlas were utilized to analyze the changes of brain spontaneous activity. Compared with the resting state, the decreased ReHo after acupuncture at KI3 in both groups were concentrated in the left postcentral, right paracentral lobule, and right SMA. Moreover, the subjects in the HY group showed declined ReHo in brain regions involving the right lingual and precentral. However, those subjects in the HE group presented decreased ReHo in the right postcentral and precentral, left supramarginal gyrus and SMA, and both cingulum middle after needling in KI3. Compared with the resting state, the HY group in the postneedling state showed lower mean intranetwork FC in sensory/somatomotor and subcortical network. And the internetwork FC between sensory/somatomotor and dorsal attention had significantly decreased after acupuncture. Furthermore, the internetwork FC between subcortical and dorsal attention and between subcortical and cerebellar showed the most obvious elevations after needling in the HY group. In the elder group, both FCs of internetwork and intranetwork primarily involving sensory/somatomotor, cingulo-opercular, and dorsal attention were declined after acupuncture. These results indicated that acupuncture at KI3 had heterogeneous acupuncture effects in different age groups. Our study led to converging evidence supporting the acupuncture effect segregation of different condition subjects and supporting evidence for prevention and treatment with acupuncture in the future.

No abstract

Speckle is an important phenomenon in various applications. It can be quantified by speckle contrast. However, at present, the influence of the phase relations among the various wavelengths on speckle contrast is rarely analyzed theoretically. Herein, a thorough method for numerically simulating the speckle pattern is presented to considering the impact of relative phase relations among wavelengths on speckle contrast. This method contains spectral shape, spectral width, and phase relations. In addition, a superluminescent pulse amplifier (SPA) with 6.5-nm bandwidth and a mode-locked laser (MLL) with 21-nm bandwidth are established to conduct the verification experiment. The experimental results show that the SPA light attains lower speckle contrast even with a narrower bandwidth than the MLL light. It is manifested that relative phase relations among wavelengths has significant effect on speckle contrast, and chaotic phase relations could be more advantageous for reducing speckle than just a broad spectrum. The simulation results agree well with experimental results. Therefore, this thorough method could provide a reliable approach to describe the characteristics of speckle pattern caused by broadband light carrying phase information. Considering the speckle contrast is positively proportional to optical coherence, this method could also be used to analyze the coherence of partially coherent light.

A comprehensive method is proposed to investigate gain narrowing and the gain saturation effect in a fiber chirped pulse amplification system. It can solve the comprehensive gain effect in time and spectral domains simultaneously based on the nonlinear Schrödinger equation. Through numerical simulation under various pump powers, our simulation results benefit from good agreement in principle with the corresponding experimental results. Our model enjoys ameliorated accuracy and generalized compatibility compared to some conventional models, thus paving the way for further applications in chirped pulse amplifications.