开角型青光眼患者结膜微血管结构的临床研究

目的应用功能裂隙灯活体显微镜(FSLB)探究开角型青光眼患者结膜微循环的血流动力学情况。方法采用FSLB对18例开角型青光眼患者的结膜微血管血流动力学进行测量并将其分为两组,右眼为A组,左眼为B组。球结膜经数字相机进行较高清晰度的视野成像后,形成非侵入性球结膜微循环血流灌注图(n MPMs),同时以60帧/s高成像速率和×210高放大率对血流动力学成像。应用定制软件,进一步对结膜n MPMs进行分形分析,进行血管密度及血流动力学测定。结果与A组比较,B组结膜的微血管各方位密度、长度、直径、微动脉及微静脉血流速度均无改变,差异无统计学意义(P>0.05);A、B两组上、下侧微动脉和微静脉的血流速度<鼻、颞侧微动及静脉血流速度,差异有统计学意义(P<0.05);A、B两组内结膜的各方位微血管密度、长度、直径比较,差异有统计学意义(P<0.05)。结膜微血管密度、长度、直径由大到小排列为:颞侧/鼻侧>下方>上方。结论功能性裂隙灯生物显微镜能用于检测开角型青光眼患者球结膜微循环血流动力学改变情况。

Design and Experiment of Triangular Prism Mast with Tape-Spring Hyperelastic Hinges

Because of the limited space of the launch rockets, deployable mechanisms are always used to solve the phenomenon. One dimensional deployable mast can deploy and support antenna, solar sail and space optical camera. Tape-spring hyperelastic hinges can be folded and extended into a rod like configuration. It utilizes the strain energy to realize self-deploying and drive the other structures. One kind of triangular prism mast with tape-spring hyperelastic hinges is proposed and developed. Stretching and compression stiffness theoretical model are established with considering the tape-spring hyperelastic hinges based on static theory. The finite element model of ten-module triangular prism mast is set up by ABAQUS with the tape-spring hyperelastic hinge and parameter study is performed to investigate the influence of thickness, section angle and radius. Two-module TPM is processed and tested the compression stiffness by the laser displacement sensor, deploying repeat accuracy by the high speed camera, modal shape and fundamental frequency at cantilever position by LMS multi-channel vibration test and analysis system, which are used to verify precision of the theoretical and finite element models of ten-module triangular prism mast with the tape-spring hyperelastic hinges. This research proposes an innovative one dimensional triangular prism with tape-spring hyperelastic hinge which has great application value to the space deployable mechanisms.

Configuration Design of an Under-Actuated Robotic Hand Based on Maximum Grasping Space

Capture is a key component for on?orbit service and space debris clean. The current research of capture on?orbit focuses on using special capture devices or full?actuated space arms to capture cooperative targets. However, the structures of current capture devices are complex, and both space debris and abandoned spacecraft are non?cooperative targets. To capture non?cooperative targets in space, a lightweight, less driven under?actuated robotic hand is proposed in this paper, which composed by tendon?pulley transmission and double?stage mechanisms, and always driven by only one motor in process of closing finger. Because of the expandability, general grasping model is constructed. The equivalent joint driving forces and general grasping force are analyzed based on the model and the principle of virtual work. Which reveal the relationship among tendon driving force, joint driving forces and grasping force. In order to configure the number of knuckles of finger, a new analysis method which takes the maximum grasping space into account, is proposed. Supposing the maximum grasped object is an envelope circle with diameter of 2.5m. In the condition, a finger grasping maximum envelope circle with different knuckles is modeled. And the finger lengths with corresponding knuckles are calculated out. The finger length which consists of three knuckles is the shortest among under?actuated fingers consists of not more than five knuckles. Finally, the principle prototype and prototype robotic hand which consists of two dingers are designed and assembled. Experiments indicate that the under?actuated robotic hand can satisfy the grasp requirements.

Altered spontaneous brain activity pattern in patients with ophthalmectomy: an resting-state fMRI study

●AIM:To use the voxel-wise degree centrality(DC)method to explore the underlying functional network brain-activity in patients with ophthalmectomy.●METHODS:A total of 32 ophthalmic surgery patients(10 women and 22 men),and 32 healthy subjects(10 women and 22 men)highly matched in gender,age,and the same operation method.Everyone experienced a restingstate functional magnetic resonance imaging scan.The spontaneous brain activity could be assessed by DC.Correlation analysis was used to explore the relationships between the average DC signal values and behavior performance in different regions.Receiver operating characteristic(ROC)cur ve analysis was utilized to differentiate between ophthalmectomy patients and healthy controls(HCs).●RESULTS:Compared with HCs,ophthalmectomy patients had greatly reduced DC values in left lingual gyrus,bilateral lingual lobe,left cingulate gyrus,and increased DC values of left cerebellum posterior lobe,left middle frontal gyrus1,right supramarginal gyrus,left middle frontal gyrus2,right middle frontal gyrus.However,we did not find that there was a correlation between the average DC values from various brain regions and clinical manifestations.●CONCLUSION:Dysfunction may be caused by ophthalmectomy in lots of cerebral areas,which may show the potential pathological mechanism of ophthalmectomy and it is beneficial to clinical diagnosis.

Clinical research of fenofibrate and spironolactone for acute central serous chorioretinopathy

AIM：To compare the effectiveness of combined fenofibrate and spironolactone with fenofibrate alone for treatment of central serous chorioretinopathy（CSCR）.METHODS： Totally 60 patients（60 eyes） with a history of acute CSCR were randomed into two groups： group A with combination of fenofibrate（200 mg） and spironolactone（100 mg）,and group B with only fenofibrate（200 mg）.They were taken half an hour before meals and once per day for 8wk.The changes of the visual acuity,subjective symptom,ocular surface disease index（OSDI）,the tear film and optical coherence tomography were observed at 2,4,6,and 8wk before and after treatment.RESULTS： The best corrected visual acuity（BCVA,log MAR） was improved to 0.22 and 0.27 after treatment from baseline of 0.35 and 0.36 in groups A and B（P 〈0.05）,respectively.After 8wk treatment,the central subfield thickness（CST）,and subretinal fluid volumn（SFV） decreased significantly to 49.5% and 78.8% in group A,37.0% and 57.2% in group B.There were significant differences of CST and SFV in both groups（all P 〈0.05）.CONCLUSION：Fenofibratecombinedwithspironolactone may have more clinical efficacy in the treatment of CSCR than fenofibrate only.

Nonlinear Dynamics Analysis of Joint Dominated Space Deployable Truss Structures

Joints are necessary components in the larger space deployable truss structures which have significant effect on the dynamics behavior of these deployable joint-dominated structures. Four kinds of joints' nonlinear force-displacement relationship are analyzed based on describing function method. The dynamic responses of one-DOF jointed system under different exciting force levels are investigated to understand the influence of joint nonlinearity on dynamic responses. The influences of joint characterizing parameters on joint nonlinearities are analyzed. Dynamic responses of the modular beam-like deployable joint-dominated truss structure are tested under different sinusoidal exciting force levels. The experimental results show obvious nonlinear behaviors contributed by joints that dynamic response shifts to lower resonance frequency and higher amplitude with the increase of exciting force. The nonlinearity of the joints in the tested structure is compared with the theoretical results and identified to meet with the hysteresis nonlinearity.

Slip Detection of Robotic Hand Based on Vibration Power of Pressure Center

This paper proposes an incipient slip detection method for a robotic hand based on the vibration power of the pressure center. Firstly,an array-type pressure sensor was planted into the soft skin of the robotic hand to measure the stick-slip vibration component of the pressure center generated in the process of slip of the grasped object. Secondly,the vibration power of the pressure center was calculated based on the measured stick-slip vibration component,and was used as a slip-detection function to judge the incipient slip of the grasped object. Finally,in order to use the same threshold value to judge incipient slip for different grasping forces,a weight coefficient was experimentally identified and used in the slip-detection function. The effectiveness of the proposed slip detection method was verified by experimental results,which showed that incipient slip can be detected by the proposed slip-detection function with the same threshold value for various materials,different slipping speeds grasping forces. In addition,multiple iterations of the experiment had demonstrated that the slip detection is repeatable.

Results of meta-analysis should be treated critically

Proton pump inhibitors use increases hepatic encephalopathy risk in patients with liver disease.

Analysis of corneal morphologic and pathologic changes in early-stage congenital aniridic keratopathy

AIM：To determine typical corneal changes of congenital aniridic keratopathy（CAK）using corneal topography and confocal systems,and to identify characteristics that might assist in early diagnosis.METHODS：Patients with CAK and healthy control subjects underwent detailed ophthalmic examinations including axial length,corneal thickness,tear film condition,corneal topography,and laser-scanning in vivo confocal microscopy（IVCM）. RESULTS：In early stage aniridic keratopathy,Schirmer I test（SIT）,break-up time（BUT）,mean keratometry（mean K）and simulated keratometry（sim K）were reduced relative to controls（P〈0.05）,while simulation of corneal astigmatism（sim A）and corneal thickness were increased（P〈0.05）. In addition,significantly more eyes exhibited flat cornea compared with the control group. Inflammatory dendritic cells were present in the aniridic epithelium,with significantly increased density relative to controls（P〈0.05）. Palisade ridge-like features and abnormal cell morphology were observed in six out of sixteen CAK cases. In central cornea area,the aniridic corneas had the increased subbasal nerve density. CONCLUSION：These changes in corneal morphology in borderline situations can be useful to confirm the diagnosis of CAK.