Approximation of diffuse attenuation,Kd, for MODIS high-resolution bands

A high resolution depth attenuation product (K_d^hires) was developed using MODIS 500 m and 250 m spectral bands. The K_d^hires was compared with Wang’s operational K_d for the Chesapeake Bay. Minimal differences were observed between the two methods, with greatest deviation occurring in areas of high turbidity in the tributaries. After tuning the new K_d^hires, the mean absolute error and bias between the two algorithms was 0.22 m^?1 and 0.026 m^?1, indicating good agreement. Higher spatial resolution provides for improved retrievals along the coast and into the narrow sections of the tributaries, coinciding with areas of concern to estuarine health and coastal management applications.     

不同穴位针刺蝶腭神经节深度及方向的研究

目的:观测下关、颧髎、"蝶腭"穴的体表位置,及各穴至蝶腭神经节的针刺深度和针刺方向.方法:15具成年男性尸体,面部左右共30侧,对其面侧区进行由浅入深的解剖.以下关、颧髎、"蝶腭"穴各穴针刺至蝶腭神经节方向为穿刺入路,电动钻带克氏针穿刺延伸至对侧区域,坐标定位法测量各穴的对应穿刺点.结果:①体表位置:"蝶腭"穴与颧髎的体表距离为21 mm,与下关的体表距离为17 mm.②各穴针刺蝶腭神经节的深度:下关为49.9 mm,"蝶腭"穴为46.9 mm,颧髎为46.6 mm.③对应穿刺点坐标定位:下关针刺方向为前内上,对应于对侧的太阳和瞳子髎的中点处附近区域,对应穿刺点距对侧丝竹空的距离为17.6 mm;"蝶腭"穴针刺方向为后内上,对应穿刺点与颧弓水平线的距离为33 mm,与目外眦垂直线的距离为42 mm;颧髎针刺方向为后内上,对应穿刺点与两外耳门连线的距离为28 mm,头部正中线旁开62 mm.结论:了解下关、颧髎、"蝶腭"穴的体表位置、针刺深度、针刺方向,为临床针刺蝶腭神经节提供了依据.     

Light exposure required for optimum conversion of light activated resin systems

OBJECTIVE: The aim of this study was to evaluate the relationship between the degree of conversion (DC) of composites and the light intensity using LED-curing units and also to determine the amount of exposure required to achieve optimal curing. METHOD: The light outputs of light-curing units and the depths of cure of composites exposed to these units were determined using the methods outlined in modified ISO standards, ISO/TS10650 and ISO 4049, respectively. The distributions of DC in composites were investigated by IR spectra of microareas obtained at various depths from the irradiated surface of thin specimens cut out from the cured composites. IR spectra were measured using a Fourier transform infrared spectrometer equipped with a microscopic unit. DC was calculated from the changes in the amount of C=C double bonds in the IR spectra. RESULTS: The light intensity at various depths through the cured composite was calculated from the attenuation coefficient of each material, obtained from the linear relationship between the depth of cure and the logarithm of the amount of exposure, which is defined as the product of the irradiance and irradiation time. There was a third or fourth order regression relationship between DC and the logarithm of total light energy at a particular depth. SIGNIFICANCE: The minimum light energy required to produce a saturated DC was about 1000 s mW/cm2.     

听觉诱发电位指数、脑电双频指数及心血管反应评估"过浅麻醉"的价值

目的通过研究丙泊酚诱导过程中,听觉诱发电位指数(AAI)、脑电双频指数(BIS)及心血管反应与插管体动的关系,探讨上述监测手段是否能够反映“过浅麻醉”。方法35例ASAⅠ~Ⅱ级妇科择期手术患者,以丙泊酚进行诱导,患者入睡后,用压力袖带隔离一侧前臂,静注维库溴铵0·1mg/kg。当丙泊酚靶控输注(TCI)达到设定血浆靶浓度(3·5μg/ml)后行气管内插管。记录隔离侧手臂运动(体动)情况,并以是否发生体动反应为准将患者分为体动组与非体动组。记录患者诱导前、插管前的SBP、DBP、HR、BIS、AAI及插管后2min内上述指标的最大值。结果体动组AAI插管后明显高于插管前(P<0·01),而非体动组插管前、后的差异无显著意义;两组患者BIS插管前、后组内及组间的差异均无显著意义;插管引起的DBP、SBP增高体动组明显大于非体动组(P<0·01),但HR变化两组相似。结论BIS仅是衡量睡眠深度的指标,AAI及BP反映“过浅麻醉”,反映机体对伤害性刺激的反应较BIS敏感。     

经尿道前列腺汽化电切术中电切深度标识的探讨

目的 探讨经尿道前列腺汽化电切术(transurethral electrovaporization of the prostate，TUVP)电切深度标识的可行性。方法 回顾性分析616例前列腺增生症临床资料，其中310例术前彩超提示合并前列腺钙化，156例合并膀胱结石，23例合并膀胱肿瘤。TUVP操作过程中，观察到合并前列腺结石和机械操作“打滑现象”，停止电切。结果 全组手术时间30～120min，平均75min。术中验证术前彩超提示合并前列腺钙化的310例前列腺钙化为结石，同时发现其余306例均存在结石。1例术中膀胱穿孔，无尿道直肠瘘和尿道电切综合征发生。325例随访3～6个月，平均4．5月，最大尿流率由6．5～8．5ml／s提高到18～22ml／s，残余尿由70～150ml降至0～10ml，国际前列腺症状评分由19～24．5分降至0～7分。138例膀胱结石和23例膀胱肿瘤无复发。结论 前列腺结石和机械操作“打滑现象”作为TUVP的电切深度标识是切实可行的。     

Epileptic seizure of El mouse initiates at the parietal cortex: depth EEG observation in freely moving condition using buffer amplifier

The initiation site of seizure discharges and the relationship between behavioral manifestations and electroencephalography were investigated in the El mouse, a hereditary epilepsy model. The chronic depth electrodes were implanted stereotaxically into the frontal cortex, parietal cortex, temporal cortex, hippocampus, striatum, amygdaloid complex, non-specific nuclei of thalamus and substantia nigra. Electrical activities were recorded in freely moving condition with use of the buffer amplifier devised in the laboratory and behaviors were monitored simultaneously. Seizure spike discharges started in the parietal cortex and spread out into other brain areas. When the hippocampus was involved, the tonic convulsion occurred behaviorally. The paper describes the first direct evidence of the initiation and propagation of seizure discharges in the brain of El mouse.     

The Reliability of Arousal Threshold During Sleep

Thirty-five subjects from two independent studies were awakened at EEG-defined periods during the night with 1000 Hz ascending tone series. Awakenings were made five to eight times per night during stage 2, stage 4, or REM sleep over a series of nights in good and poor sleepers. Reliability was assessed within stage, within night, between stages, and between nights. Good and poor sleepers did not differ in either depth of sleep or reliability of arousal threshold and were thus pooled in the analyses. From night to night, the most consistency was seen in stage 4 (r=.74), although REM reliability (r?₁= .49) and stage 2 reliability (r?₁= .50 and r?₁= .69 in the two respective studies) estimates were also greater than zero. Early sleep onset and morning arousals were more variable. Reliability estimates on arousal thresholds taken within the same night for stage 2 were r= .64 and r?₁= .77 for the two studies and r= .96 for REM. The depth of sleep was not correlated with awake auditory threshold. It was concluded that five or six carefully placed arousals could give a good estimate of an individual's usual arousal threshold.     

FT-IR photoacoustic depth profiling spectroscopy of enamel

Photoacoustic Fourier transform infrared (PA-FT-IR) depth profiling spectra of the enamel of an intact human tooth are obtained in a completely nondestructive fashion. The compositional and structural changes in the tissue are probed from the enamel surface to a depth of about 200 m. These changes reflect the state of tissue development. The subsurface carbonate gradient in the enamel could be observed over the range of about 10–100 m. The carbonate-to-phosphate ratio increases in the depth profile. The depth profile also reveals changes in the substitutional distribution of carbonate ions. Type A carbonates (hydroxyl substituted) increase relative to type B carbonates (phosphate substituted) with increasing thermal diffusion length. In addition to the changes in the carbonate ion distribution and content, the PA-FT-IR depth profile clearly indicates a dramatic increase in the protein content relative to the phosphate content with increased depth. The changes in the carbonate content and distribution, along with the changes in the protein content, may be responsible for the changes observed in the apatitic structure in the depth profile of the enamel.     

深刺局部穴治疗三叉神经痛疗效观察

目的:寻找提高三叉神经痛疗效的有效方法.方法:将90例原发性三叉神经痛患者随机分为深刺组(45例)、常规针刺组(45例).常规针刺组以局部近取浅刺和循经远取手足阳明经穴位为主,深刺组在此基础上对局部穴位采用深刺达神经干的方法.治疗3个疗程后统计疗效.结果:两组均收到明显疗效,深刺组临床治愈12例,显效24例,好转7例,无效2例,有效率为95.6%;而常规针刺组分别为7例、15例、12例、11例、75.6%.深刺组疗效优于常规针刺组(P＜0.05).结论:针刺治疗三叉神经痛,局部穴位深刺加循经远取手足阳明经穴位,能明显提高疗效.     

危险穴位针刺深度与角度的研究

目的:为临床医生提供安全的进针深度和角度的参考数值.方法:(1)经穴的断层解剖法为先在尸体上标经定穴,经-20～-30 ℃冰冻,再通过穴位作多种断面,以反映在各种角度、深度、范围进针时所涉及的断面解剖结构.(2)经穴的层次解剖法为先在尸体上选穴定位,在穴位处用钢针刺入或刺染,再逐层解剖,以反映穴位区的解剖结构.结果:得到头颈部、胸腹部和腰背部常用危险穴位针刺的安全深度和危险深度的范围,以及部分危险穴位进针的方向和角度.