静息态功能磁共振技术在针灸研究中的应用进展

探讨静息态功能磁共振技术（fMRI）在针灸治疗各种临床疾病的机理。由于其广泛的可用性、无创性,相对较低的成本以及良好的空间分辨率使其应用越来越广泛,但基于静息态fMRI的应用进展的综述较少。本文就其在针灸治疗脑血管相关疾病、针灸镇痛、针灸治疗药物成瘾作用及治疗其他脑相关性疾病做一综述,以便更好地研究并阐明相关机理。     

儿童癫痫静息态fMRI的研究进展

癫痫是脑神经元同步异常放电导致的脑功能紊乱综合征,其反复发作可造成认知功能的损伤和行为的异常。静息态功能MRI（rs-fMRI）是一种血氧水平依赖功能MRI,可对大脑静息态下的自发活动进行研究。目前大量癫痫rs-fMRI 的研究主要集中于成年病人,然而儿童癫痫的病因、发病机制及临床治疗等都与成人癫痫不尽相同。主要对近年来rs-fMRI 在儿童癫痫静息态网络、认知功能障碍研究及其在儿童癫痫手术治疗方面的应用予以综述。     

儿童癫静息态fMRI的研究进展

癲是脑神经元同步异常放电导致的脑功能紊乱综合征,其反复发作可造成认知功能的损伤和行为的异常。静息态功能MRI(rs-fMRI)是一种血氧水平依赖功能MRI,可对大脑静息态下的自发活动进行研究。目前大量癲rs-fMRI的研究主要集中于成年病人,然而儿童癫的病因、发病机制及临床治疗等都与成人癫不尽相同。主要对近年来rs-fMRI在儿童癫静息态网络、认知功能障碍研究及其在儿童癫手术治疗方面的应用予以综述。     

静息态fMRI在神经精神疾病中的研究进展

静息态功能MRI(rs-f MRI)是一种利用血氧水平依赖(BOLD)功能MRI来研究大脑静息状态下脑功能活动的方法。其能够反映静息态下脑功能的生理或病理状态,并且具有无辐射、影响因素少、操作简便易行等优势,对临床诊断和治疗效果评估具有重要价值。近年来,随着影像数据分析技术的快速发展,rs-f MRI已经成为大脑功能研究的有效工具,临床应用逐渐扩展。对rs-f MRI技术的基本原理、方法及其在神经精神疾病研究中的应用进行综述。     

静息态脑功能网络分析方法及在肝性脑病的研究进展

静息态脑功能网络分析方法是目前脑功能研究最常用、最基本的方法之一。该方法利用血氧水平依赖功能磁共振成像(BOLD-f MRI)采集数据,分析全脑或特定脑区脑网络连接强弱的情况,不仅能无创定位功能网络连接异常的脑区,还能了解各种神经心理疾病的病理生理基础及发病机制。近年来,随着影像技术的发展、脑网络分析方法的不断完善,静息态脑功能网络的研究为临床疾病的诊断治疗提供了更为广阔的思路。     

针刺治疗轻度认知功能障碍的静息态fMRI研究进展

轻度认知障碍(MCI)是处在正常老龄化和痴呆间的一个移行状态,可进展为阿尔兹海默病,给社会和家庭带来沉重负担。针刺作为中医的重要治疗手段,其疗效已在国际上得到认可,且已用于MCI的治疗。然而,针刺治疗MCI的机制尚未阐明。静息态f MRI作为一种无创、无辐射的影像学检查方法,可显示患者早期的脑功能变化及治疗的中枢响应,已用于MCI的早期诊断及针刺治疗机制的研究。现就基于静息态f MRI的MCI诊断及其针刺治疗研究进行综述。     

静息态脑功能成像在青少年网络成瘾中的初步研究

目的运用静息态脑功能磁共振成像局部一致性(ReHo)方法探索网络成瘾(internet addiction,IA)青少年静息态脑功能的变化。资料与方法采用3.0TMRI对18名IA青少年和18名年龄、性别相匹配的正常对照组进行静息态脑功能扫描。采用静息态功能磁共振数据处理工具包(DPARSF)进行数据预处理和ReHo分析,采用双样本t检验分析,P<0.001,体素个数>10个被认为有统计学意义。结果在静息状态下,与正常组比较,IA组以下脑区ReHo降低有统计意义,包括右侧海马旁回、右侧舌回、左侧脑岛、右侧中央后回和左侧顶下小叶。结论 IA青少年静息状态下脑默认网络与正常对照组存在差异,这可能为研究IA的发病机制提供新的依据。     

重度吸烟依赖者脑局部一致性静息态功能MRI研究

目的 基于脑静息态功能MRI(fMRI)研究重度吸烟依赖者(HS)脑局部一致性(ReHo),探讨HS自我觉醒机制.方法 选取30例HS(HS组)和年龄、性别匹配的31名无酒精烟草滥用健康志愿者(对照组)行3.0T静息态fMRI采集,采用统计参数图(SPM)5软件进行数据预处理,Rest软件计算ReHo值,HS组和对照组间ReHo值比较采用两样本t检验,最终获得ReHo值有统计差异的功能图.结果(1)与对照组比较,静息态下HS组ReHo值减低脑区包括两侧楔前叶、额上回、前额叶内侧及右角回、额下回、枕下回、小脑和左额中回等.(2)与对照组比较,静息态下HS组ReHo值增高脑区包括两侧岛叶、海马旁回、顶叶白质、桥脑及左侧顶下小叶、舌回、丘脑、额下眶回、额颞叶白质、小脑等,且呈左侧化趋势.结论 HS静息态脑默认模式网络活动减低;活动增强脑区组成吸烟成瘾静息态网络,并呈左侧化趋势,反映HS自我觉醒机制.     

脊髓损伤后大脑网络连接变化的功能MRI研究进展

脊髓损伤(SCI)后大脑功能的重塑对患者的感觉运动恢复起着重要作用,但亦会导致病理性损害。到目前为止,其重塑和对功能影响的机制尚不清楚。静息态f MRI作为一种无创且能直观显示脑区活动的技术,已经成为评估大脑功能变化的重要手段,为SCI后脑网络及功能连接的机制研究提供了有效的方法。本文针对SCI后静息态脑功能连接(FC)的变化及其可能机制进行综述。     

静息态功能MRI对注意障碍性多动症病人内在脑功能异常的研究

正摘要目的采用静息态功能MRI研究注意障碍性多动症(ADHD)儿童及青少年病人的局域及网络水平的脑功能改变,并评估静息脑活动改变与ADHD病人执行功能障碍的相     

Influence of a TcN core on the biological and physicochemical behavior of Tc complexes of L,L-EC and L,L-ECD

^99mTc-nitrido complexes of L,L-ethylene dicysteine (^99mTcN-L,L-EC) and ^99mTcN-L,L-ethylene dicysteine diethylester (^99mTcN-L,L-ECD) were prepared and their characteristics compared to those of the respective ^99mTc-oxo complexes. ^99mTcN-L,L-EC and ^99mTcO-L,L-EC migrate to similar extents during electrophoresis at pH 12, but, at pH 6, ^99mTcN-L,L-EC migrates further than ^99mTcO-L,L-EC. Renal excretion of ^99mTcN-L,L-EC is inferior to that of ^99mTcO-L,L-EC, indicating that the TcN-glycine sequence has lower affinity for the renal tubular system. Both ^99mTcO-L,L-ECD and ^99mTcN-L,L-ECD are neutral, but ^99mTcN-L,L-ECD is hydrophilic and shows minimal brain uptake in both mice and the baboon.     

Theoretical basis for long-term measurements of equilibrium factors using LR 115 detectors

In this paper, we propose a method to determine the equilibrium factor using a bare LR 115 detector. The partial sensitivities ρ_i of the LR 115 detector to ²²²Rn and its alpha-emitting short-lived progeny, ²¹⁸Po and ²¹⁴Po, were investigated. We first determined the distributions of lengths of major and minor axes of the perforated alpha tracks in the LR 115 detector produced by ²²²Rn, ²¹⁸Po and ²¹⁴Po through Monte Carlo simulations. The track parameters were calculated using a track development model with a published V function, by assuming a removed active layer of 6.54 μm. The distributions determined for different alpha emitters were found to completely overlap with one another. This implied equality of partial sensitivities for radon and its progeny, which was also confirmed through analytical considerations. Equality of partial sensitivities makes possible convenient measurements of the proxy equilibrium factor F_p, which is defined in the present work as (F₁+F₃) and is equal to the ratio between the sum of concentrations of the two alpha emitting radon progeny (²¹⁸Po+²¹⁴Po) to the concentration of radon gas (²²²Rn). In particular, we have found F_p=(ρ/ρ_itC₀)−1, where ρ (track/m²) is the total track density on the detector, ρ_i=0.288×10⁻² m, t is the exposure time and C₀ (Bq/m³) is the concentration of ²²²Rn. If C₀ is known (e.g. from a separate measurement), we can obtain F_p. The proxy equilibrium factor F_p is also found to be well correlated with the equilibrium factor between radon gas and its progeny through the Jacobi room model. This leads to a novel method for long-term determination of the equilibrium factor.     

Effects of increased ventilation and improved pulmonary gas-exchange on maximal oxygen uptake and power output

Recent reports suggest that aerobic performance at very high levels may be limited by the pulmonary system. The purpose of the present study was to compare respiratory functions at rest and during graded maximal aerobic exercise (cycle ergometry) between well-trained (TR, n = 11) and untrained (UT, n = 14) individuals while breathing atmospheric air, normoxic helium (He) and oxygen-enriched mixture. When the subjects breathed air, TR exhibited lower exercise ventilatory reserve (MVV-VE_max), ratio between minute ventilation (VE) and oxygen uptake (V_o2) and SaO₂ than UT. Breathing HE resulted in an increase in VE and V_o2max in both groups but in an increased VE/V_o2 and SaO₂ and maximal mechanical cycle ergometer load, only in TR. Compared with air, breathing an oxygen-enriched mixture resulted in increased peak exercise SaO₂ and maximal mechanical load in both groups. It is concluded that arterial O₂ desaturation secondary to a relative hypoventilatory response may limit V_o2max and aerobic performance capacity at high work levels.     

Assessment of the skeletal status by MR relaxometry techniques of the lumbar spine: comparison with dual X-ray absorptiometry

Purpose: To measure lumbar spine T2*, T2, T2′ and T1 MR relaxometry parameters and compare them with lumbar spine bone mineral density (BMD) in a group of postmenopausal women. Materials and methods: Lumbar spine T2*, T2, T2′ and T1 MR relaxometry parameters and BMD values were assessed in 101 postmenopausal women (mean age: 61.8±7.1 (1 S.D.) years); of them 63 referred to as control subjects (group A, BMD T-scores ≥ −2.5 S.D.) and 38 as osteoporotic (group B, BMD T-scores < −2.5 S.D.). All magnetic resonance imaging (MRI) examinations were performed on an 1.5 T imaging system using: (a) a 2D single slice multi echo (32 echoes) gradient echo (MEGRE) sequence (TR/TE1/TE32/FA: 160/2.7/74.93 ms/25°) for the T2* measurement, (b) a respiratory gated 2D single slice Multi Echo (16 echoes) Spin Echo (MESE) sequence (TR/TE1/TE16/FA: 2000–2500/22.5/360 ms/90°) for the T2 measurement and (c) a 2D single slice multi TI (18 repeats) turbo Fast Low Angle Shot (turbo FLASH) sequence (TR/TE/TI1/TI16/FA: 11/4.2/10/5000 ms/10°) for the T1 measurement. T2′ was calculated from its definition equation: (1/T2′ = 1/T2* − 1/T2). Lumbar spine BMD was assessed using DXA. Results: All measured parameters showed statistically significant differences between groups A and B (from P<0.05 to <0.001). All parameters showed significant associations with subject’s age ranging from r=0.245 (P<0.05) for the T2 up to r=0.377 (P<0.001) for the T2*. All parameters showed significant associations with subject’s BMD measurements ranging from r=−0.184 (P<0.05) for the R1 = (1/T1) up to r=−0.345 (P<0.0005) for the T2. Conclusion: Among the MR relaxometry parameters studied, T2* and T2 showed better discrimination of patients with osteoporosis from control subjects.     

Effects of a YMCA Starter Fitness Program

This paper reports the findings of the effect of an eight-week starter fitness program on the first 1,362 people enrolled in it. The subjects were tested for cardiorespiratory fitness, body fat and weight, O₂ max, muscular strength and endurance, and flexibility, using the YMCA physical fitness test battery before the program started and after eight weeks of training. The classes met for one hour, three times a week. Both men and women reduced body weight, body fat, and resting heart rate, and increased O₂ max, flexibility, and muscular strength and endurance. Improved fitness was related to compliance and whether the subject or his company paid for the program.     

Maximal oxygen uptake as a predictor of performance ability in women and men elite cross-country skiers

Maximal oxygen uptake (O_2max) was measured in 51 females and males classified as either world-class, medium-class or less successful elite skiers. The O_2max in the male world-class skiers was significantly higher (mean 85.6 ml·kg⁻¹·min⁻¹ or 355 ml·min⁻¹ kg⁻²³) than in the other elite skiers. World-class and medium-class female skiers had identical mean O_2max expressed in ml·kg⁻¹·min⁻¹ (70.7 and 70.6, respectively), but the values differed significantly when the unit ml·min⁻¹kg^−2/3 was used (274 and 264, respectively). O_2max expressed as ml·min⁻¹·kg^−2/3 reflects differences in performance capability among elite skiers better than the unit ml·kg⁻¹·min⁻¹.     

Evaluation of peak-to-total ratio for germanium detectors

An equation for the peak-to-total ratio, P, of a germanium detector is proposed in the following form. P=_p/_t+a(V/A)+b(V/A)²/2 where _p/_t is the ratio of the photoelectric to the total detection efficiency for a germanium detector, V/A is the volume-to-surface ratio of the detector, and the parameters of a and b are experimentally given as a function of incident photon energy. The first term in the right side of the equation expresses the fractional single photoelectric-to-total interaction between photons and the detector. The second and third terms correspond to the multiple interactions. The peak-to-total ratios for the germanium detector with a sensitive volume up to 200 cm³ were calculated by the equation. They coincide with the experimental values to within an uncertainty of several percent in the energy region 0.3–3 MeV.