超声彩色脉搏波技术在定量评价2型糖尿病患者颈动脉弹性变化中的应用

目的 探讨超声彩色脉搏波(UFPWV)技术在定量评价2型糖尿病患者颈动脉血管管壁弹性变化中的应用价值。方法 回顾性研究。纳入2018年7月-2019年3月蚌埠医学院第一附属医院收治的97例2型糖尿病患者为观察组,其中男47例、女50例,年龄20~74(46.6±9.3)岁;根据颈动脉内中膜厚度(IMT)将观察组分为颈动脉粥样斑块组(A组)、颈动脉内中膜增厚组(B组)和颈动脉内中膜正常组(C组),依据下肢动脉有无斑块将C组分为下肢动脉斑块组(C1组)、下肢动脉无斑块组(C2组)。选取2017年12月-2018年12月在蚌埠医学院第一附属医院体检中心血糖及颈动脉IMT正常的健康体检者64人为对照组,其中男25人、女39人,年龄20~74(44.3±12.0)岁。运用UFPWV采集脉搏波速度 (PWV),计算颈动脉收缩早期PWV(PWV-BS)及收缩晚期PWV(PWV-ES),分析各项参数组间的差异。结果 观察组中,A组颈动脉PWV-BS、PWV-ES分别为(9.51±1.25)m/s、(10.79±1.64)m/s,B组分别为(8.47±0.91)m/s、(9.81±1.05)m/s,C组分别为(7.97±0.77)m/s、(9.07±0.74)m/s,对照组颈动脉PWV-BS、PWV-ES分别为(6.10±1.00)m/s、(7.40±1.20)m/s,A组、B组、C组及对照组间颈动脉PWV-BS、PWV-ES测量值依次降低,差异均有统计学意义(P值均<0.05)。C组中,C1组颈动脉PWV-BS、PWV-ES分别为(7.83±0.85)m/s、(8.82±0.59)m/s,C2组分别为(8.14±0.64)m/s、(9.34±0.79)m/s, C1组PWV-ES显著高于C2组,差异有统计学意义(t=3.402,P＜0.01),而两组间PWV-BS的差异无统计学意义(P>0.05)。结论 UFPWV技术可定量评价2型糖尿病患者颈动脉弹性变化,并可通过PWV-ES的改变评估颈动脉形态学正常的患者动脉粥样硬化的进展程度,对临床诊疗具有一定意义。     

Reflection of an Orienting Reflex in the Phases of Evoked Potentials in the Rabbit Visual Cortex and Hippocampus during Substitution of Stimulus Intensity

Experiments on conscious rabbits were performed using the oddball paradigm, in which a rare (deviant) and common (standard) stimuli were of the same color but different intensities. Deviant stimuli were of lesser intensity. Recordings were made of evoked potentials induced by series of uniform deviant stimuli (without using standard stimuli), which were presented at the beginning and end of stimulation. Visual evoked potentials recorded in response to deviant stimuli in the visual cortex and hippocampus showed increases in the amplitudes of phases, shifted towards positivity as compared with responses to standard stimuli and uniform deviant stimuli at the beginning and end of stimulus blocks. Significant changes affected phases P1 and P2 of visual evoked potentials in the cortex and phases P1, N1, and P2 in the hippocampus. The most significant increase in evoked potentials in the cortex was seen for the P2 peak (P130). It is suggested that changes in responses to oddball-deviant stimuli result from an orienting reflex to rare, unexpected stimuli and that the P2 (P130) peak in the cortex is associated with transmission of information regarding changes in the intensity of the light. The amplitude of this peak was shown to be decreased in responses to uniform deviant stimuli at the beginning and end of stimulus blocks. It was also demonstrated that the clearest and most contrasting changes in visual evoked potentials in responses to deviant and standard stimuli were seen with the smallest differences in intensity between these types of stimulus, this reflecting increases in the orienting reflex at threshold differences.     

Estimation of bladder wall location in ultrasound images

A method of automatically estimating the location of the bladder wall in ultrasound images is proposed. Obtaining this estimate is intended to be the first stage in the development of an automatic bladder volume calculation system. The first step in the bladder wall estimation scheme involves globally processing the images using standard image processing techniques to highlight the bladder wall. Separate processing sequences are required to highlight the anterior bladder wall and the posterior bladder wall. The sequence to highlight the anterior bladder wall involves Gaussian smoothing and second differencing followed by zero-crossing detection. Median filtering followed by thresholding and gradient detection is used to highlight as much of the rest of the bladder wall as was visible in the original images. Then a ‘bladder wall follower’—a line follower with rules based on the characteristics of ultrasound imaging and the anatomy involved—is applied to the processed images to estimate the bladder wall location by following the portions of the bladder wall which are highlighted and filling in the missing segments. The results achieved using this scheme are presented.     

Molecular genetics of human color vision

The significant advances in our understanding of color vision has been due to the convergence of information from behavioral and molecular genetic analyses. The molecular biology of the visual pigments; molecular genetic basis of variation in normal and abnormal color vision, and regulation of the genes at the LWS-MWS pigment gene locus are discussed.     

Role of the blue mechanism in wavelength discrimination

The role of blue cones as well as the pathways they supply (collectively called the "blue mechanism") is evaluated by comparing ordinary wavelength discrimination functions with those obtained using two methods designed to inhibit the blue mechanism selectively. These methods use a just-noticeable-border criterion (JNB), instead of the usual one of just-noticeable-difference, and a yellow preadapting field to induce transient tritanopia. Without transient tritanopia, the data obtained using the just-noticeable-border criterion reveal a small contribution of the blue mechanism to wavelength discrimination. Transient tritanopia, with JNB, produces an additional selective loss of wavelength discrimination in a spectral region flanking 460 nm, which yields a function resembling those for tritanopes previously examined.     

Eccentric visual acuity in patients with macular disease

A series of cards each containing a two dimensional array of identical Snellen "E's" was used to determine best eccentric visual acuity in patients with macular disease having Snellen visual acuity of 20/70 or worse. Each "full field E" card simultaneously presents the same letter to foveal and parafoveal areas. This test can therefore determine quickly if potentially useful vision is present in any area of the central visual field. In our study of 37 eyes, 70% demonstrated potential visual acuity at least two times better than visual acuity measured by conventional methods, and 20% demonstrated at least a fourfold improvement. This suggests that most patients with macular disease do not spontaneously employ their best remaining area of retina for fixation.     

Colored neon flanks and line gap enhancement

When a colored line connects two black (or differently colored) lines across a gap, colored neon flanks are seen on either side of it. These flanks extend over gap sizes of 50 min arc foveally and are not explained by Bezold-type assimilation. They may be elicited by black lines as short as 6 min arc adjoining the colored line at each end. To maximize these flanks, the black and colored lines must appear linearly continuous. Nonaligned junctions weaken the effect and an angular tilt of more than 40 dog destroys it. In this and other respects, (local) neon flanks are similar to van Tuijl's (global) neon color spreading (1975). Both phenomena have analogs in brightness perception. We propose that neon spreading is a lateral extension of neon flanks across the empty space between them, and discuss similarities of these effects with other brightness illusions (Schumann, Prandtl, Ehrenstein). For this group of illusions the term "line gap enhancement" is introduced to imply perceptual enhancement of changes in brightness and/or color along lines. Correspondences between the psychophysical properties and structural prerequisites for line gap enhancement on one hand and neuronal response properties of end-zone inhibited (hypercomplex) cortical cells on the other are discussed.     

Binocular contrast summation—II. Quadratic summation

Quadratic summation is presented as a rule that describes binocular contrast summation. The rule asserts that for left-eye and right-eye contrasts C_L and C_R, there is an effective binocular contrast C given by the formula:$C=\sqrt{{(C_L)}^2+{(C_R)}^2}.$Pairs of left-eye and right-eye stimuli that produce equal values of C are equivalent. Quadratic summation is applied to the results of experiments in which stimuli presented to the two eyes differ only in contrast. It provides a good, first-order account of binocular summation in contrast detection, contrast discrimination, dichoptic masking, contrast matching and reaction time studies. A binocular energy-detector model is presented as a basis for quadratic summation.     

经阴道彩色多普勒超声对子宫腺肌瘤的诊断价值

目的：探讨经阴道彩色多普勒超声对子宫腺肌瘤的诊断价值。方法：选取许昌中医院2020年1月至2022年1月期间收治的80例子宫腺肌瘤患者为研究对象,对上述患者实施经阴道彩色多普勒超声诊断,获得对应的诊断结果,随后将该结果和术后病理分析结果进行比较,最终得出诊断效果。结果：本研究80例子宫腺肌瘤患者中,经阴道彩色多普勒超声检出75例,漏诊或误诊5例,诊断准确率为93.75%;经阴道彩色多普勒检查诊断为子宫腺肌瘤的75例患者中,按照发病部位划分,有10例(13.33%)子宫腺肌瘤出现在子宫前壁区域,65例(86.67%)出现在子宫后壁部位;按照病情特点划分,有63例(84.00%)为单发子宫腺肌瘤,12例(16.00%)为子宫腺肌瘤合并子宫肌瘤。此外,75例患者中有3例患者并发卵巢内膜异位症。75例患者的子宫动脉血流阻力指数为0.75±0.05、搏动指数为1.37±0.04、舒张期峰值速度为(5.83±0.14)cm·s^-1、收缩期峰值速度为(71.74±0.25)cm·s^-1。结论：经阴道彩色多普勒超声可通过超声特征、血流分布、多普勒频谱特点,准...     

Prevalence of Vision Loss and Associations With Age-Related Eye Diseases Among Nursing Home Residents Aged ≥65 Years

ObjectivesTo examine data from Delaware nursing homes to determine prevalence of age-related eye diseases (AREDs), vision impairment, and blindness and to compare the findings with the results of 11 US investigations of vision and eye health in nursing homes.DesignThis is a cross-sectional, retrospective study of nursing home patients.Setting and ParticipantsTwenty nursing homes in Delaware participated in the study, yielding comprehensive eye examination records for 2019 study participants.MethodsSummary statistics and regression analyses.ResultsThe overall prevalence of vision impairment or blindness was 63.8% and was above 60% for each age, sex, and race category. Prevalence of vision impairment or blindness was 68.4% among patients with cataracts, 69.4% among patients with macular degeneration, 70.5% among patients with glaucoma, and 68.4% among patients with diabetic retinopathy. Prevalence of blindness was 14.1%. Among patients with AREDs, prevalence of blindness ranged from 15.0% for patients with cataracts to 22.6% for patients with diabetic retinopathy. When compared with other investigations, we found wide variation in vision and eye factors reported and wide variation in the prevalence of those factors. Only 4 studies diagnosed both AREDs and visual function. Seven studies reported AREDs, and 7 reported vision impairment and/or blindness. Vision impairment or blindness ranged from 29% to 67%; cataract ranged from 32% to 83%; macular degeneration ranged from 4.6% to 70.7%. Glaucoma ranged from 5.3% to 41.4%; diabetic retinopathy ranged from 1.7% to 3.1%.Conclusions and ImplicationsComprehensive eye examinations showed that vision impairment and blindness affected 63.8% of nursing home residents. Compared with other studies, there was a wide range of vision factors reported and wide variation in the prevalence of vision impairment or blindness and AREDs. This investigation suggests the importance of eye care in nursing homes and the importance of reporting standard vision and eye health factors to inform policy and practice.