Determining a continuous marker for sleep depth

Detection and quantification of sleep arousals is an important issue, as the frequent arousals are known to reduce the quality of sleep and cause daytime sleepiness. In typical sleep staging, electroencephalograph (EEG) is the core signal and based on the visual inspection of the frequency content of EEG, non-rapid eye movement sleep is staged into four somewhat rough categories. In this study, we aimed at developing a continuous marker based on a more rigorous spectral analysis of EEG to measure or quantify the depth of sleep. In order to develop such a marker, we obtained the time-frequency map of two EEG channels around sleep arousals and identified the frequency bands that show the most change during arousals. We then evaluated classification performance of the potential signals for representing the depth of sleep, using receiver operating characteristic analysis. Our comparisons based on the area under the curve values revealed that the sum of absolute powers in alpha and beta bands is a good continuous marker to represent the depth of sleep. Higher values of this marker indicate low-quality sleep and vice versa. We believe that use of this marker will lead to a better quantification of sleep quality.     

Functional properties of rotation-sensitive neurons in the posterior parietal association cortex of the monkey

We studied the functional properties of rotation-sensitive (RS) neurons of the posterior parietal association cortex in detail. We classified 58 neurons as RS neurons on the basis of statistical analysis, to indicate that their responses to rotary movement were significantly greater (P<0.01) than those to linear movement of the same stimulus. We calculated rotation index, 1 — (L/R), in 82 cells, where L/R is the ratio of net response to linear movement to that to rotary movement. All the RS neurons had rotation index greater than or equal to 0.3. The recording site of these RS neurons was localized in the posterolateral part of area PG (area 7a of Vogt), on the anterior bank of the caudal superior temporal sulcus (STS), in the region partly overlapping the medial superior temporal (MST) area. We compared the response of RS neurons to rotation with that to shearing movement as well as to linear movement. In the majority of RS neurons the ratio of shearing response to rotation response (S/R) was smaller than the ratio of linear response to rotation response (L/R), indicating that the response to rotation was not due to a simple combination of linear movements in the opposite direction. Most of the RS neurons responded to the rotary movement of a single spot as well as that of a slit, although the response was smaller (average 70%) for the former. Most of the RS neurons had large receptive fields (60–180° in diameter) and their responses were independent of the position within the receptive field. The responses of most RS neurons increased monotonically with the increase in angular velocity and were also dependent on the size of the stimulus, although the rate of increase was small when the length was more than 10°. The majority of RS neurons (37/58) responded better to rotation in depth than to that in the frontoparallel plane. Some of them (12/37) responded to diagonal rotation rather than to sagittal or horizontal rotation. We found that some depth RS neurons showed reversal in the preferred direction when we used a trapezoidal window-like plate as the rotating stimulus in the monocular viewing condition, just as occurs in the case of the Ames window illusion. The response of some RS neurons (5/7) was enhanced by tracking eye movement. The enhanced responses were observed during rotary tracking but not during linear tracking. Other RS neurons (n = 2) showed maximum response to the rotation of the monkey chair in the light, as a result of convergence of visual and vestibular signals. We concluded that the continuous change of direction of movement was the most important cue for RS neurons to respond selectively to rotary movement in contrast to linear translational movement, and that these neurons were likely to discriminate the direction and orientation of the plane of rotation of the object in space.     

Fast,epithermal and thermal photoneutron dosimetry in air and in tissue equivalent phantom for a high-energy X-ray medical accelerator

Photoneutron (PN) dosimetry in fast, epithermal and thermal energy ranges originated from the beam and albedo neutrons in high-energy X-ray medical accelerators is highly important from scientific, technical, radiation protection and medical physics points of view. Detailed dose equivalents in the fast, epithermal and thermal PN energy ranges in air up to 2 m as well as at 35 positions from the central axis of 12 cross sections of the phantom at different depths were determined in 18 MV X-ray beams of a Siemens ONCOR accelerator. A novel dosimetry method based on polycarbonate track dosimeters (PCTD)/¹⁰B (with/without cadmium cover) was used to determine and separate different PN dose equivalents in air and in a multilayer polyethylene phantom. Dose equivalent distributions of PNs, as originated from the main beam and/or albedo PNs, on cross-plane, in-plane and diagonal axes in 10 cm × 10 cm fields are reported. PN dose equivalent distributions on the 3 axes have their maxima at the isocenter. Epithermal and thermal PN depth dose equivalent distributions in the phantom for different positions studied peak at ～3 cm depth. The neutron dosimeters used for the first time in such studies are highly effective for separating dose equivalents of PNs in the studied energy ranges (beam and/or albedo). The PN dose equivalent data matrix made available in this paper is highly essential for detailed patient dosimetry in general and for estimating secondary cancer risks in particular.     

Early Relapse for Multiple Myeloma Patients Undergoing Single Autologous Stem Cell Therapy: A Single-center Experience

Introduction

Multiple myeloma is a heterogeneous disease with diverse clinical courses and patient outcomes. Although the introduction of novel agents has improved the overall survival (OS) of multiple myeloma patients, reports have highlighted that a subset of patients persists who experience early relapse (ER) and whose prognosis is significantly poorer than that of patients with a longer therapy response.

Narcotrend 监测在老年无痛肠镜检查中的运用

目的：评价 Narcortrend 监测在老年患者无痛肠镜肠道肿瘤筛查中的效果。方法：选择2015年3月至2015年12月进行肠镜肠道肿瘤筛查患者240例,65～75岁,其中男性130例,女性110例。随机分为 A 组、B组、C 组,每组80例。麻醉方法采用靶控输入（target-controlled infusion,TCI）丙泊酚,使用麻醉深度监测仪（Narcor-trend）监测麻醉深度,A 组维持麻醉深度指数（narcortrend index,NI）值为 D0（64～57）,即常规较浅麻醉,B 组维持NI 值为 D1（56～47）,即常规中等深度麻醉,C 组维持 NI 值为 D2（46～37）,即常规深度麻醉。手术结束停止用药。记录患者入睡时间、苏醒时间、丙泊酚用量,及术中体动、高血压、低血压、心动过速、心动过缓、呼吸抑制的发生情况。结果：三组顺利完成手术,各组均未发生术中体动;B 组相比于 A 组,C 组,麻醉并发症发生率较低（χ2＝6.337,P ＝0．038）。三组入睡时间、苏醒时间无明显差异（P ＞0．05）。结论：无痛肠镜检查中,Narcortrend 镇静 NI值为 D1（56～47）时比较适合老年患者。     

高频超声对膝关节半月板急慢性损伤的诊断价值分析

目的分析探讨高频超声对膝关节半月板急慢性损伤的诊断价值。方法选取2017年1月至2018年2月牡丹江医学院第二附属医院收治的50例膝关节半月板急慢性损伤患者(设为研究组)及50例健康体检者(设为对照组)作为研究对象,应用高频超声检测其膝关节滑膜厚度、髌上囊积液深度及滑膜血流状况,并予以对比。结果研究组患者膝关节半月板在基线外侧较为突出且可见点状或条状强回声区,内侧副韧带变形,部分患者伴有不同程度的水肿,滑膜厚度为(6.25±2.20) mm,髌上囊积液深度为(7.35±1.45) mm,滑膜血流为0级者23例、Ⅰ级者12例、Ⅱ级者12例、Ⅲ级者3例;对照组研究对象膝关节半月板回声强度中等且均匀,边缘清晰,滑膜厚度为(1. 10±0.46) mm,髌上囊积液深度为(2. 12±0.43) mm,滑膜血流为0级者38例、Ⅰ级者12例。两组研究对象膝关节滑膜厚度、髌上囊积液深度及滑膜血流状况对比,P均0.01,差异具有统计学意义。结论高频超声对膝关节滑膜厚度、髌上囊积液及滑膜血流均较敏感,在膝关节半月板急慢性损伤的诊断中特异性较高,且操作简便,可作为膝关节半月板急慢性损伤的首选诊断方法予以推广、普及。     

Maintenance of anaesthesia

The maintenance phase of general anaesthesia begins immediately following induction of, and ends immediately prior to emergence from, a state of intended unrousable unconsciousness. Maintenance of anaesthesia requires the application of a wide range of knowledge and skills, demanding a solid grounding in basic science, practical abilities and team management. These factors are considered in this article.     

Concept of depth dose functions for radiotherapy beams: definition and values for different energy beams.

Depth dose functions are defined and based on empirically observed interrelation of percent depth doses for different energy beams. By using this function, if the depth dose for a given source-surface distance (SSD), field size and depth are known for a standard beam energy, the corresponding depth dose for another beam energy can be derived. The results obtained are accurate to within ±1% in a considerable range of SSD, field size and depths used in routine radiotherapy. The formulation can be extended to hold at depths between the surface and depth of maximum but is somewhat less accurate than ±1% for depths up to two times the depth of maximum. This method is of considerable usefulness in computer dosimetry algorithms to save memory space and/or to increase speed by avoiding multiple table look up procedures. It is the particular importance in irregular field dose calculations for high energy beams where specific measured data for separation of primary and scatter components of dose are not available.     

Differential localization in dorsal funiculus of fibres originating from different receptors

Summary The cervical part of the dorsal funiculus in the cat was investigated by recording from single fibres and by recording of mass activity in dissected fascicles. It is demonstrated that large myelinated fibres originating from different receptors ascend at different depths of the funiculus. Fibres from hair and claw receptors occupy the superficial part of the funiculus and fibres from touch and vibration receptors the deep part. Fibres from muscle receptors occur at an intermediate depth of the funiculus. A large number of synaptically activated fibres ascend in the deep part.     

Rapid evaluation of many pulse echo system characteristics by use of a triggered pulse burst generator with exponential decay

A pulse burst generator is utilized in which the pulses are triggered by the transmitter pulse of the ultrasound system being tested. The pulses are spaced the equivalent of every 2 mm in the body, and their amplitude decays with 0, 1.25, or 2.5 dB/cm over greater than a 50 dB dynamic range. By replacing the ultrasound transducer with the pulse generator, one can record quite easily the accuracy of depth gain compensation (DGC) and of distance measurements in A mode and B mode. If the DGC on the ultrasound unit can be turned to zero, the unit's A mode display characteristic and B mode gray scale curve can be determined rapidly and the receiver gain control or attenuator can be calibrated. Measurement of a receiver signal-to-noise ratio is possible, and more quantitative imaging should be facilitated as well.