检索结果-南通市图书馆

Optic disc coloboma associated with macular retinoschisis:A case report

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2022年第20期10卷 6966-6973页

作者： Wei Zhang xiao-yan peng Beijing Ophthalmology and Visual Science Key Laboratory Beijing Institute of OphthalmologyBeijing Tongren Eye CenterBeijing Tongren HospitalCapital Medical UniversityBeijing 100005China

BACKGROUND To report an unusual case of bilateral optic disc coloboma associated with macular retinoschisis in the left *** SUMMARY A 37-year-old woman presented with complaints of blurred and distorted vision in her left eye for more than 1 *** examination demonstrated choroidal atrophy around the optic disc in both eyes,with a cup-to-disc ratio of *** retinal detachment in the macular area of the left *** eye macular blood flow imaging optical coherence tomography(Angio-OCT)showed macular retinal serous ***-face OCT showed that the canal gully-like structure formed by the defect of the optic disc nerve fiber layer between the optic disc and macula,serous detachment area was connected with the enlarged optic disc coloboma through the canal gully-like structure,and the fluid leaked from the enlarged and thinned optic disc coloboma into the retinal layer of the macular *** with optic disc abnormalities and macular degeneration must be monitored *** the follow-up period,the use of optic disc stereography and 3D-OCT,en-face,and Angio-OCT imaging can clarify the correlation between macular retinoschisis and optic disc *** Macular retinoschisis may be owing to the combined force of disc edge loss,enlarged optic disc coloboma,the canal gully-like structure formed by the defect of the nerve fiber layer around the optic disc,and the traction of the posterior vitreous cortex.

关键词： Optic disc coloboma Macular retinoschisis Optical coherence tomography Case report

A high performance waveform and a new ranging method for the proximity detector

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2020年第4期16卷 834-845页

作者： Qi-le Chen Xin-hong Hao xiao-peng yan Ping Li School of Mechatronical Engineering Beijing Institute of TechnologyBeijing 100081China

Signal modulation is an essential design factor for proximity detectors and directly affects the system's potential *** order to achieve the advantages of chaotic codes bi-phase modulation(CCBPM)and linear frequency modulation(LFM) simultaneously,this paper designed a waveform which combined chaotic codes bi-phase modulation and linear frequency modulation(CCBPM-LFM) for proximity *** CCBPM-LFM waveform was analyzed in the aspect of time delay resolution(TDR) and Doppler tolerance(DT) based on ambiguity function(AF).Then,a ranging method,which we called instant correlation harmonic demodulation(ICHD),was presented for the detector using the CCBPM-LFM *** combining time domain instant correlation with harmonic demodulation,the ICHD solved the problem caused by combination modulation and made the most of the linear frequency modulation(LFM) harmonics and the correlation of chaotic ***,a prototype was implemented and ranging experiments were carried *** the theoretical analysis and experimental results,the proximity detector used the CCBPM-LFM waveform has an outstanding detection performance.

关键词： Proximity detectors Detection performance Combination modulation Chaotic codes bi-phase modulation Linear frequency modulation

Optical Coherence Tomography Features of Tuberculous Serpiginous-like Choroiditis and Serpiginous Choroiditis

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2018年第5期31卷 327-334页

作者： wang xiao na you qi sheng zhao hui ying peng xiao yan Beijing Institute of Ophthalmology Beijing Tongren Eye Center Beijing Ophthalmology and Visual Science Key Lab Beijing Tongren Hospital Capital Medical University Beijing 100730 China

Objective To investigate optical coherence tomography（OCT） characteristics of tuberculous serpiginous-like choroiditis（Tb-SLC） and serpiginous choroiditis（SC） and to perform OCT to differentiate between these *** This retrospective,case-control study examined consecutively enrolled patients with active Tb-SLC or *** underwent comprehensive ocular examinations and imaging（OCT,color fundus photography,autofluorescence imaging,fluorescein angiography,and indocyanine green angiography）.Findings were examined and compared between eyes with SC and *** Nine patients with active Tb-SLC（14 eyes） and 8 with active SC（12 eyes） were *** following OCT findings were observed significantly more often in the Tb-SLC group than in the SC group： vitreal hyper-reflective spots [5 Tb-SLC eyes（36%）,no SC eyes：P = 0.02],intraretinal edema [11 Tb-SLC eyes（79%）,3 SC eyes（25%）：P = 0.01],sub-retinal pigment epithelium（RPE） drusenoid deposits [11 Tb-SLC eyes（79%）,2 SC eyes（17%）：P 〈 0.01],and choroidal granulomas [8 Tb-SLC eyes（57%）,2 SC eyes（17%）：P = 0.03].A hyporeflective,wedge-shaped band was observed more often in the SC group [5 Tb-SLC eyes（36%）,9 SC eyes（75%）：P = 0.045] than in the Tb-SLC *** incidence of other OCT signs did not differ between the groups and included outer nuclear layer hyper-reflection,outer retinal tabulation,and choriocapillaris point-like *** Vitreal hyper-reflective spots,intraretinal fluid,sub-RPE drusenoid deposits,and choroidal granulomas on OCT images may indicate ***,a hyporeflective,wedge-shaped band may indicate ***,OCT is likely helpful in differentiating between Tb-SLC and SC.

关键词： Optical coherence tomography Choroiditis Serpiginous Tuberculosis

Repeater jamming suppression method for pulse Doppler fuze based on identity recognition and chaotic encryption

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2021年第3期17卷 1002-1012页

作者： Jian Dai Xin-hong Hao Qiang Liu xiao-peng yan Ping Li Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing 100081China Ordnance Science Institute of China Beijing 100089China

Pulse Doppler(PD) fuze is widely used in current battlefield. However, with the threat of repeater jamming, especially digital radio frequency memory technology, the deficiency in the anti-repeater jamming of a traditional PD fuze increasingly emerges. Therefore, a repeater jamming suppression method for a PD fuze based on identity(ID) recognition and chaotic encryption is proposed. Every fuze has its own ID which is encrypted with different chaotic binary sequences in every pulse period of the transmitted signal. The thumbtack-shaped ambiguity function shows a good resolution and distance cutoff characteristic. The ability of anti-repeater jamming is emphatically analyzed, and the results at different signal-to-noise ratio(SNR) show a strong anti-repeater jamming ability and range resolution that the proposed method possesses. Furthermore, the anti-repeater jamming ability is influenced by processing gain, bit error rate(BER) and correlation function. The simulation result validates the theoretical analysis, it shows the proposed method can significantly improve the anti-repeater jamming ability of a PD fuze.

关键词： Pulse Doppler fuze ID Chaotic binary code Encryption Repeater jamming

Adaptive target and jamming recognition for the pulse doppler radar fuze based on a time-frequency joint feature and an online-updated naive bayesian classifier with minimal risk

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2022年第3期18卷 457-466页

作者： Jian Dai Xin-hong Hao Ze Li Ping Li xiao-peng yan Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing100081China

This paper considers the problem of target and jamming recognition for the pulse Doppler radar fuze(PDRF).To solve the problem,the matched filter outputs of the PDRF under the action of target and jamming are ***,the frequency entropy and peak-to-peak ratio are extracted from the matched filter output of the PDRF,and the time-frequency joint feature is *** on the time-frequency joint feature,the naive Bayesian classifier(NBC)with minimal risk is established for target and jamming *** improve the adaptability of the proposed method in complex environments,an online update process that adaptively modifies the classifier in the duration of the work of the PDRF is *** experiments show that the PDRF can maintain high recognition accuracy when the signal-to-noise ratio(SNR)decreases and the jamming-to-signal ratio(JSR)***,the applicable analysis shows that he ONBCMR method has low computational complexity and can fully meet the real-time requirements of PDRF.

关键词： Pulse Doppler radar fuze(PDRF) Target and jamming recognition Time-frequency joint feature Online-update naive Bayesian classifier minimal risk(ONBCMR)

Th lymphocyte subsets in patients with Vogt-KoyanagiHarada disease

在线全文

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2019年第2期12卷 207-211页

作者： Liang Liang xiao-yan peng Hong Wang The First Affiliated Hospital of Chongqing Medical University Chongqing Key Laboratory of Ophthalmology and Chongqing Eye Institute Beijing Tongren Eye Center Beijing Key Laboratory of Ophthalmology and Visual Science Beijing Tongren HospitalCapital Medical University

AIM: To assess helper T(Th) lymphocyte subset balance in patients with Vogt-Koyanagi-Harada(VKH) disease. METHODS: Sixty-eight active VKH patients and seventytwo inactive VKH patients were included in this study. One hundred healthy individuals served as controls. Peripheral blood was obtained from VKH patients and healthy controls. Th lymphocyte subsets were analyzed by flow cytometry. Plasma concentration of interleukin(IL)-17, IL-10, transforming growth factor(TGF)-β, IL-23 and IL-6 was examined by enzyme-linked immunosorbent assay(ELISA). RESULTS: VKH patients with active uveitis had significantly higher percentages of both Th1 and Th17 cells and lower percentages of regulatory T(Treg) cells as compared with inactive VKH patients and healthy controls. Th1/Th2 and Th17/Treg ratios were also significantly elevated in active VKH patients. The percentages of Th1, Th17 and Treg cells and the Th1/Th2, Th17/Treg ratio did not differ between inactive VKH patients and healthy controls. There was no difference concerning the percentage of Th2 cells among all the groups. VKH patients with active uveitis showed an elevated level of peripheral Th17 related cytokines levels(TGF-β, IL-6, IL-23, and IL-17) and a decreased level of Treg related cytokines(IL-10) compared with inactive VKH patients and healthy controls. Inactive VKH patients showed no differences in peripheral Th17 related cytokines(TGF-β, IL-6, IL-23, and IL-17) and Treg related cytokines(IL-10) levels compared with healthy controls. CONCLUSION: Th1 and Th17 cells are significantly increased and Treg cells significantly decreased in active VKH compared with inactive VKH or healthy controls. Therefore, Th lymphocyte subset analysis may serve as a disease biomarker for VKH.

关键词： Vogt-Koyanagi-Harada disease Th lymphocyte Th17 cell Treg cell cytokines

Macular ganglion cell complex injury in different stages of anterior ischemic optic neuropathy

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2021年第21期9卷 5830-5839页

作者： Wei Zhang Xin-Quan Sun xiao-yan peng Beijing Tongren Eye Hospital Capital Medical UniversityBeijing 100730China Beijing Aier Intech Eye Hospital Beijing 100021China China-Japanese Friendship Hospital Beijing 100029China

BACKGROUND Anterior ischemic optic neuropathy(AION)is a group of ophthalmic diseases in which the optic nerve is injured causing ***,the pathogenesis,clinical manifestations,and clinical treatments of AION are yet *** a few related experimental or clinical reports are available on the *** this study,spectral domain optical coherence tomography(SD-OCT)was used to examine the morphology of thickness swelling and atrophic changes of macular ganglion cell complex(mGCC)in the different stages of AION that were then compared with the visual ***,the clinical value of mGCC examination was alleged to be similar to that of the visual *** To explore the mGCC injury at different stages in AION and the clinical *** Cases with AION were analyzed in a retrospective ***-OCT was used to analyze the correlation between mGCC and peripapillary retinal nerve fiber layer thicknesses at different stages of AION and the changes in the corresponding stages of visual *** A total of 21 cases(28 eyes)presented *** onset time of AION was defined as early stage(within 3 wk of onset),middle stage(from 3 wk to 2 mo),and late stage(disease span>2 mo).In the early stage,the mGCC thickness of SD-OCT was within the normal high limit,and the perioptic nerve fibers thickness was more than the *** changes in the visual field in early stage were not consistent with the swelling changes in mGCC and peri-disc nerve *** addition,atrophy and thinning appeared in mGCC,and the perioptic nerve fibers were ***,the thickness was lower in the middle period than that in the early *** change in visual field was consistent with that of mGCC in this *** the late stage,mGCC shrank and thinned,and the thickness of the nerve fibers around the optic disc in the corresponding region shrank and *** The changes in mGCC thickness in patients with AION showed early,middle,and late stages of devel

关键词： Anterior ischemic optic neuropathy Macular ganglion cell complex Visual field Spectral domain optical coherence tomography Eyes

Air target recognition method against ISRJ for radio frequency proximity sensors using chaotic stream encryption

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2023年第10期28卷 267-279页

作者： Jian-feng Li Jian Dai Xin-hong Hao xiao-peng yan Xin-wei Wang Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing100081China BIT Tangshan Research Institute Beijing100081China

The interrupted-sampling repeater jamming(ISRJ)can cause false targets to the radio-frequency proximity sensors(RFPSs),resulting in a serious decline in the target detection capability of the *** article proposes a recognition method for RFPSs to identify the false targets caused by *** proposed method is realized by assigning a unique identity(ID)to each RFPS,and each ID is a periodically and chaotically encrypted in every pulse *** processing technique of the received signal is divided into ranging and ID *** the ranging part,a high-resolution range profile(HRRP)can be obtained by performing pulse compression with the binary chaotic *** suppress the noise,the singular value decomposition(SVD)is applied in the *** ID decryption,targets and ISRJ can be recognized through the encryption and decryption processes,which are controlled by random *** adaptability analysis conducted in terms of the peak-to-side lobe ratio(PSLR)and bit error rate(BER)indicates that the proposed method performs well within a 70-k Hz Doppler shift.A simulation and experimental results show that the proposed method achieves extremely stable target and ISRJ recognition accuracies at different signal-to-noise ratios(SNRs)and jamming-to-signal ratios(JSRs).

关键词： Interrupted-sampling repeater jamming(ISRJ) Radio frequency proximity sensors(RFPS) Chaotic stream encryption Air target recognition Identity(ID)decryption

Formation of ZrB2in MgO-C Composite Materials Using In-Situ Synthesis Method

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2006年第1期13卷 70-74页

作者： LI Lin HONG yan ruo SUN Jia-lin HE Zhi-yong peng xiao-yan Refractory Division Central Iron and Steel Research Institute Beijing 100081 China School of Materials Science and Engineering University of Science and Technology Beiiing Beiiing 100083 China

ZrB2 in MgO-C composite materials obtained by both microwave sintering synthesis and in-situ reaction at lower temperature was investigated. The test result shows that 66.67 % of reactant changed into Zrb2, and the other form Al2O3, which could optimize the properties of carbon containing materials. Therefore, the method of in situ synthesizing ZrB2 acting as antioxidant in carbon containing materials is considered as one of best ways to reduce the cost and ZrB2 as refractories is used on a large-scale.

关键词： ZrB2 microwave in situ synthesis carbon containing material