Publications by authors named "Hongfei Ye"

38 Publications

Generating Synthesized Ultrasound Biomicroscopy Images from Anterior Segment Optical Coherent Tomography Images by Generative Adversarial Networks for Iridociliary Assessment.

Ophthalmol Ther 2022 Jul 26. Epub 2022 Jul 26.

Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, No. 1665, Kongjiang Road, Shanghai, 200092, China.

Introduction: The aim of this study was to investigate the feasibility of generating synthesized ultrasound biomicroscopy (UBM) images from swept-source anterior segment optical coherent tomography (SS-ASOCT) images using a cycle-consistent generative adversarial network framework (CycleGAN) for iridociliary assessment on a cohort presenting for primary angle-closure screening.

Methods: The CycleGAN architecture was adopted to synthesize high-resolution UBM images trained on the SS-ASOCT dataset from the department of ophthalmology, Xinhua Hospital. The performance of the CycleGAN model was further tested in two separate datasets using synthetic UBM images from two different ASOCT modalities (in-distribution and out-of-distribution). We compared the ability of glaucoma specialists to assess the image quality of real and synthetic images. UBM measurements, including anterior chamber, iridociliary parameters, were compared between real and synthetic UBM images. Intra-class correlation coefficients, coefficients of variation, and Bland-Altman plots were used to assess the level of agreement. The Fréchet Inception Distance (FID) was measured to evaluate the quality of the synthetic images.

Results: The whole trained dataset included anterior chamber angle images, of which 4037 were obtained by SS-ASOCT and 2206 were obtained by UBM. The image quality of real versus synthetic SS-ASOCT images was similar as assessed by two glaucoma specialists. The Bland-Altman analysis also suggested high consistency between measurements of real and synthetic UBM images. In addition, there was fair to excellent agreement between real and synthetic UBM measurements for the in-distribution dataset (ICC range 0.48-0.97) and the out-of-distribution dataset (ICC range 0.52-0.86). The FID was 21.3 and 24.1 for the synthetic UBM images from the in-distribution and out-of-distribution datasets, respectively.

Conclusion: We developed a CycleGAN model to translate UBM images from non-contact SS-ASOCT images. The CycleGAN synthetic UBM images showed fair to excellent reproducibility when compared with real UBM images. Our results suggest that the CycleGAN technique is a promising tool to evaluate the iridociliary and anterior chamber in an alternative non-contact method.
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http://dx.doi.org/10.1007/s40123-022-00548-1DOI Listing
July 2022

One-Year Outcomes of Modified Technique for Scleral Fixation of a Three-Piece Intraocular Lens Without Conjunctival Opening.

Front Med (Lausanne) 2022 2;9:856800. Epub 2022 Jun 2.

Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.

Purpose: This study aimed to present the 1-year follow-up of a modified technique for scleral fixation of three-piece intraocular lens (IOLs) without conjunctival incision.

Materials And Methods: A retrospective chart review of a consecutive series of 10 eyes of nine patients who underwent scleral IOL fixation using the modified technique was performed. Data were collected 1 year after surgery for all patients.

Results: The range of follow-up time was between 1 year and 31 months. At the last follow-up point, the IOL was well-positioned and the visual acuity was good (as limited by primary diseases). Short-term complications included pupillary IOL capture ( = 1) and decreased intraocular pressure ( = 1), and no long-term complications were observed.

Conclusion: Outcome data support this technique as a viable option for the management of secondary IOL fixation with flexible usage of more designs of IOLs.
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http://dx.doi.org/10.3389/fmed.2022.856800DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9200955PMC
June 2022

A Novel Subfoveal Perfluorocarbon Liquid Removal Technique Combining a 25-Gauge Retrobulbar Needle With a Built-in 30-Gauge Needle.

Front Med (Lausanne) 2022 31;9:894991. Epub 2022 May 31.

Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.

Introduction: To report a novel combining a 25-gauge retrobulbar needle with a built-in 30-gauge needle surgical technique for subfoveal perfluorocarbon liquid (PFCL) removal.

Materials And Methods: Fourteen eyes of 14 patients who underwent subfoveal PFCL removal with a 25-gauge retrobulbar needle combined with a built-in 30-gauge needle were studied. The 30-gauge needle was inserted into the 25-gauge retrobulbar needle. The bent tip of the built-in 30-gauge needle was used to create a 30-gauge retinotomy at the farthest edge of the subfoveal PFCL droplet. Then, a flute cannula was used to aspirate the PFCL through the previously created retinotomy. The best-corrected visual acuity (BCVA) was determined, previous surgical history and post-operative complications were recorded.

Results: Fourteen cases were analyzed. Most eyes (92.85%) showed an improvement in BCVA after surgery. The mean change in the BCVA was -0.7 ± 0.72 logarithm of the minimum angle of resolution (logMAR) units ( = 0.006). Post-operative complications included a self-healing macular hole in one eye and vitreous hemorrhage in one eye. Post-operative optical coherence tomography confirmed removal of the subfoveal PFCL with restoration of the macular fovea.

Conclusion: Combining a 25-gauge retrobulbar needle with a built-in 30-gauge needle to remove subfoveal PFCL is easy to perform and carries little potential risk of subretinal impairment. This method also provides relatively good macular contour with functional improvement.
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http://dx.doi.org/10.3389/fmed.2022.894991DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9192974PMC
May 2022

Secondary glaucoma caused by a special type of persistent fetal vasculature.

Int Ophthalmol 2022 Apr 13. Epub 2022 Apr 13.

Department of Ophthalmology, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Kongjiang Road, No. 1665, Shanghai, 200092, China.

Purpose: To investigate the clinical features and surgical outcomes in infants with glaucoma secondary to a special anterior-anterior type of persistent fetal vasculature (AAPFV).

Methods: This study retrospectively reviewed the medical records of infants who underwent of the synechialysis, pupilloplasty, with or without lensectomy and limbal vitrectomy due to AAPFV and with at least 6 months of postoperative follow-up.

Results: Eleven patients were included. The median age at surgery was 4.0 months (interquartile range: 7 months). The mean follow-up was 21.0 ± 11.3 months. All patients achieved a normal anterior chamber, improved pupillary configuration, and normal intraocular pressure (IOP), except one that developed phthisis bulbi at the last visit. A total of 81.8% (9/11) eyes exhibited improved corneal transparency. Histopathologic findings of four pupillary membranous specimens under light microscopy showed similar components compared with PFV. Two eyes developed postoperative complications, including retinal detachment and hyphema, requiring additional surgeries. Postoperative visual acuity changed from no light perception to light perception in 6/9 patients.

Conclusions: AAPFV is a special type of PFV with a potential for secondary glaucoma. Surgery treatment may offer better vision with improved cosmetic outcomes and a better controlled IOP.

Trial Registration: The study was approved by the local institutional review board (IRB) (Approval No. XHEC-D-2021-043, Ethical Committee of Xin Hua Hospital Affiliated to Shanghai Jiao Tong University, Shanghai, China).
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http://dx.doi.org/10.1007/s10792-022-02277-7DOI Listing
April 2022

Oculocutaneous Albinism.

Asia Pac J Ophthalmol (Phila) 2022 Mar 25. Epub 2022 Mar 25.

Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China.

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http://dx.doi.org/10.1097/APO.0000000000000506DOI Listing
March 2022

Development and Clinical Validation of Semi-Supervised Generative Adversarial Networks for Detection of Retinal Disorders in Optical Coherence Tomography Images Using Small Dataset.

Asia Pac J Ophthalmol (Phila) 2022 May 1;11(3):219-226. Epub 2022 May 1.

Department of Ophthalmology, Xinhua Hospital, Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China.

Purpose: To develop and test semi-supervised generative adversarial networks (GANs) that detect retinal disorders on optical coherence tomography (OCT) images using a small-labeled dataset.

Methods: From a public database, we randomly chose a small supervised dataset with 400 OCT images (100 choroidal neovascularization, 100 diabetic macular edema, 100 drusen, and 100 normal) and assigned all other OCT images to unsupervised dataset (107,912 images without labeling). We adopted a semi-supervised GAN and a supervised deep learning (DL) model for automatically detecting retinal disorders from OCT images. The performance of the 2 models was compared in 3 testing datasets with different OCT devices. The evaluation metrics included accuracy, sensitivity, specificity, and the area under the receiver operating characteristic curves.

Results: The local validation dataset included 1000 images with 250 from each category. The independent clinical dataset included 366 OCT images using Cirrus OCT Shanghai Shibei Hospital and 511 OCT images using RTVue OCT from Xinhua Hospital respectively. The semi-supervised GANs classifier achieved better accuracy than supervised DL model (0.91 vs 0.86 for local cell validation dataset, 0.91 vs 0.86 in the Shanghai Shibei Hospital testing dataset, and 0.93 vs 0.92 in Xinhua Hospital testing dataset). For detecting urgent referrals (choroidal neo-vascularization and diabetic macular edema) from nonurgent referrals (drusen and normal) on OCT images, the semi-supervised GANs classifier also achieved better area under the receiver operating characteristic curves than supervised DL model (0.99 vs 0.97, 0.97 vs 0.96, and 0.99 vs 0.99, respectively).

Conclusions: A semi-supervised GAN can achieve better performance than that of a supervised DL model when the labeled dataset is limited. The current study offers utility to various research and clinical studies using DL with relatively small datasets. Semi-supervised GANs can detect retinal disorders from OCT images using relatively small dataset.
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http://dx.doi.org/10.1097/APO.0000000000000498DOI Listing
May 2022

Modified trisection technique: one-trip explantation for foldable intraocular lens.

Retina 2022 Feb 7. Epub 2022 Feb 7.

Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China Department of Ophthalmology, Zhenjiang Ruikang Hospital, Jiangsu, China Department of Ophthalmology, Shanghai International Medical Center, Shanghai, China Department of Ophthalmology, Shanghai Kongjiang Hospital, Shanghai, China Department of Ophthalmology, Shibei Hospital, Shanghai, China.

Purpose: We present a new technique that allows an intraocular lens (IOL) to be explanted through the small incisions used in modern cataract surgery.

Methods And Results: The IOL optic is cut into three connected pieces at the 1-mm-wide end with scissors. Then, with the stabilizing counterforce provided by a vitreo-retinal forceps via a paracentesis, the middle piece is removed first, followed by the two side pieces connected with haptics flipped over at the connected part. These two parts overlap each other when passing through the incision, eventually resulting in the explantation of the IOL as an intact piece.

Conclusions: We believe this method provides a simple and effective way to remove IOLs through very small incisions, which could also reduce complications and hasten patient's recovery.
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http://dx.doi.org/10.1097/IAE.0000000000003430DOI Listing
February 2022

Biomimetic Janus photonic soft actuator with structural color self-reporting.

Mater Horiz 2022 04 4;9(4):1243-1252. Epub 2022 Apr 4.

State Key Laboratory of Fine Chemicals, Dalian University of Technology, P. O. Box 89, West Campus, 2# Linggong Rd, Dalian 116024, China.

Soft actuators with variable signal/color play an important role in the fields of targeted locomotion, artificial phototropism, drug screening, cargo transportation, and interactive sensing. The ability to achieve rapid response, large curvature, wide bending angle, and full-color display continues to be an unresolved challenge for artificial actuating materials. Inspired by the angle-dependent structural color of broad-tailed hummingbird and the Janus wettability of the lotus leaf, a Janus photonic soft actuator (JPSA) was fabricated by integrating an underwater super-oleophilic copper micro-nano array and oil-phobic inverse opal through a Laplace channel. The JPSA exhibits unidirectional permeability to underwater oil droplets. Attractively, with the combination of a swellable super-oleophilic surface and photonic crystals, JPSAs were endowed with oil-controlled reversible bending behavior with self-reporting angle-dependent color indication. We described for the first time the directional actuating mechanism induced by underwater oil unidirectional penetration and revealed the corresponding actuating kinetics and the inner-stress distribution/transfer by using structural color. As an extension of such theory, a rapid responsive JPSA with a wide bending angle and full-color self-reporting is further fabricated. This work provides an efficient strategy for oil directional transportation and separation in aqueous media and inspires the fabrication of a soft actuator/sensor with structural color self-reporting.
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http://dx.doi.org/10.1039/d1mh01693hDOI Listing
April 2022

Influence of Mo Segregation at Grain Boundaries on the High Temperature Creep Behavior of Ni-Mo Alloys: An Atomistic Study.

Materials (Basel) 2021 Nov 18;14(22). Epub 2021 Nov 18.

International Research Center for Computational Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Faculty of Vehicle Engineering and Mechanics, Dalian University of Technology, Dalian 116024, China.

Based on molecular dynamics simulations, the creep behaviors of nanocrystalline Ni before and after the segregation of Mo atoms at grain boundaries are comparatively investigated with the influences of external stress, grain size, temperature, and the concentration of Mo atoms taken into consideration. The results show that the creep strain rate of nanocrystalline Ni decreases significantly after the segregation of Mo atoms at grain boundaries due to the increase of the activation energy. The creep mechanisms corresponding to low, medium, and high stress states are respectively diffusion, grain boundary slip and dislocation activities based on the analysis of stress exponent and grain size exponent for both pure Ni and segregated Ni-Mo samples. Importantly, the influence of external stress and grain size on the creep strain rate of segregated Ni-Mo samples agrees well with the classical Bird-Dorn-Mukherjee model. The results also show that segregation has little effect on the creep process dominated by lattice diffusion. However, it can effectively reduce the strain rate of the creep deformation dominated by grain boundary behaviors and dislocation activities, where the creep rate decreases when increasing the concentration of Mo atoms at grain boundaries within a certain range.
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http://dx.doi.org/10.3390/ma14226966DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8625863PMC
November 2021

Detection of shallow anterior chamber depth from two-dimensional anterior segment photographs using deep learning.

BMC Ophthalmol 2021 Sep 22;21(1):341. Epub 2021 Sep 22.

Department of Ophthalmology, Shanghai Aier Eye Hospital, No. 1286, Hongqiao Road, Changning District, Shanghai, 200050, China.

Background: The purpose of this study was to implement and evaluate a deep learning (DL) approach for automatically detecting shallow anterior chamber depth (ACD) from two-dimensional (2D) overview anterior segment photographs.

Methods: We trained a DL model using a dataset of anterior segment photographs collected from Shanghai Aier Eye Hospital from June 2018 to December 2019. A Pentacam HR system was used to capture a 2D overview eye image and measure the ACD. Shallow ACD was defined as ACD less than 2.4 mm. The DL model was evaluated by a five-fold cross-validation test in a hold-out testing dataset. We also evaluated the DL model by testing it against two glaucoma specialists. The performance of the DL model was calculated by metrics, including accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve (AUC).

Results: A total of 3753 photographs (1720 shallow AC and 2033 deep AC images) were assigned to the training dataset, and 1302 photographs (509 shallow AC and 793 deep AC images) were held out for two internal testing datasets. In detecting shallow ACD in the internal hold-out testing dataset, the DL model achieved an AUC of 0.86 (95% CI, 0.83-0.90) with 80% sensitivity and 79% specificity. In the same testing dataset, the DL model also achieved better performance than the two glaucoma specialists (accuracy of 80% vs. accuracy of 74 and 69%).

Conclusions: We proposed a high-performing DL model to automatically detect shallow ACD from overview anterior segment photographs. Our DL model has potential applications in detecting and monitoring shallow ACD in the real world.

Trial Registration: http://clinicaltrials.gov , NCT04340635 , retrospectively registered on 29 March 2020.
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http://dx.doi.org/10.1186/s12886-021-02104-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8457334PMC
September 2021

Case Report: Posterior Uveitis after Divalent Human Papillomavirus Vaccination in an Asian Female.

Optom Vis Sci 2020 06;97(6):390-394

Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China.

Significance: Vaccine-associated uveitis has appeared in recent years because of various vaccines, whereas cases for human papillomavirus (HPV) vaccination were rarely reported. With more and more females becoming aware of its importance and choosing HPV vaccination, much more attention should be paid on the adverse effects of it.

Purpose: The purpose of this study was to report a rare case of posterior uveitis after divalent HPV vaccination in an Asian female.

Case Report: A 29-year-old woman presented with acute vision loss accompanied by symptoms of headache, tinnitus, and myalgia after the third injection of HPV vaccination. The best-corrected visual acuity dropped to 20/500 for both eyes, and optical coherence tomography revealed bilateral multifocal submacular fluid. A short course of oral prednisone as well as Ozurdex intravitreal injection resulted in the reversal of all signs and symptoms.

Conclusions: Although this case resembled Harada disease, we diagnosed it as vaccine-induced uveitis rather than coincidental autoimmune disease based on the rapid response to a short course of systemic corticosteroids. Because vaccine-induced uveitis is rare and difficult to distinguish from coincidental autoimmune disease, our case reminds eye care providers to be aware of the possible association between vaccination and a Harada-like reaction and to ask appropriately directed questions when obtaining history from young patients with uveitis. Based on this case, we also suggest Ozurdex intravitreal injection as a potential therapeutic choice, especially for patients with contraindication or personal concern to systemic corticosteroid.
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http://dx.doi.org/10.1097/OPX.0000000000001523DOI Listing
June 2020

An adjustable permeation membrane up to the separation for multicomponent gas mixture.

Sci Rep 2019 May 14;9(1):7380. Epub 2019 May 14.

International Research Center for Computational Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Faculty of Vehicle Engineering and Mechanics, Dalian University of Technology, Dalian, 116024, P.R. China.

The mixture separation is of fundamental importance in the modern industry. The membrane-based separation technology has attracted considerable attention due to the high efficiency, low energy consumption, etc. However, the tradeoff between the permeability and selectivity is a crucial challenge, which is also difficult to adjust during the separation process. Based on the salt water-filled carbon nanotubes, a separation membrane with the adjustable molecular channels by the electric field is proposed in this work. The separation mechanism is clarified on the basis of the characteristic size of the molecular channel and the overall effective diameter of gas molecules. The molecular dynamics simulation is performed to examine the feasibility and validity of the designed separation membrane. The simulations on the binary gas mixture (H and N) reveal the flow control and high-purity separation as the electric field intensity varies. As for the mixed gas with the three components (H, N and Xe), the successive separations and the switch between the high-efficiency and high-purity separation could be achieved only through adjusting the electric field intensity. This work incorporates the control into the membrane-based separation technology, which provides a novel solution for the complex industrial separation requirement.
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http://dx.doi.org/10.1038/s41598-019-43751-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6517568PMC
May 2019

Regulating the mechanical properties of nanocrystalline nickel via molybdenum segregation: an atomistic study.

Nanotechnology 2019 Jul 5;30(27):275702. Epub 2019 Mar 5.

International Research Center for Computational Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Faculty of Vehicle Engineering and Mechanics, Dalian University of Technology, Dalian 116024, People's Republic of China.

The effects of segregation of impurity molybdenum (Mo) atoms on the tensile mechanical properties of nanocrystalline nickel (Ni) are investigated with molecular dynamics simulation. The results show that the segregation of Mo atoms induces an obvious increase in the elastic modulus and strength of nanocrystalline Ni, and the strengthening effect is more significant with smaller grain size. When the grain size decreases below a critical value, at which the softening occurs in non-segregated Ni-Mo alloy, no evident softening phenomenon is observed in Mo-segregated systems. Furthermore, based on a bicrystal configuration, it is found that Mo atoms segregating to the grain boundary reduce the energy and mobility of the grain boundary, increasing the grain boundary stability and thus accommodating the strengthening. The present findings will shed light on the fabrication of high strength nanocrystalline materials by controlling the segregation of atoms.
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http://dx.doi.org/10.1088/1361-6528/ab0cceDOI Listing
July 2019

Aggregation of nanoparticles regulated by mechanical properties of nanoparticle-membrane system.

Nanotechnology 2018 Oct 18;29(40):405102. Epub 2018 Jul 18.

International Research Center for Computational Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Faculty of Vehicle Engineering and Mechanics, Dalian University of Technology, Dalian 116024, People's Republic of China.

The aggregation of nanoparticles (NPs) on the cell membrane is crucial for the cellular uptake process and has important biological implications in protein-membrane interactions. In this paper, we systematically investigate how the aggregation is regulated by the mechanical properties of the NP-membrane system, including the membrane tension, and the size and shape of the NPs. Results show that when NPs aggregate parallel to the cell membrane, increasing the membrane tension will modulate the membrane-mediated interaction between the NPs from attractive to attractive-repulsive and finally to purely repulsive. In contrast, the membrane-mediated interaction is attractive and independent of the membrane tension when the NPs aggregate to a tubular configuration. For the aggregation of NPs of different sizes, the large-size NP is wrapped to a greater extent than the small-size NP. For the aggregation of nonspherical NPs, low aspect ratio and weak NP-membrane adhesion strength lead to the side-to-side configuration, whereas a system with a high aspect ratio and strong NP-membrane adhesion strength prefers the tip-to-tip configuration. Importantly, NPs of different sizes and anisotropic shapes are found to facilitate the aggregation process by reducing the energy barrier that should be overcome during the aggregation. The results reveal the mechanism of the aggregation of NPs on the cell membrane and provide guidelines to the design of NP-based drug delivery systems.
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http://dx.doi.org/10.1088/1361-6528/aad443DOI Listing
October 2018

Divergent effect of electric fields on the mechanical property of water-filled carbon nanotubes with an application as a nanoscale trigger.

Nanotechnology 2018 01 11;29(2):025707. Epub 2017 Dec 11.

International Research Center for Computational Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Faculty of Vehicle Engineering and Mechanics, Dalian University of Technology, Dalian 116024, People's Republic of China.

Polar water molecules exhibit extraordinary phenomena under nanoscale confinement. Through the application of an electric field, a water-filled carbon nanotube (CNT) that has been successfully fabricated in the laboratory is expected to have distinct responses to the external electricity. Here, we examine the effect of electric field direction on the mechanical property of water-filled CNTs. It is observed that a longitudinal electric field enhances, but the transverse electric field reduces the elastic modulus and critical buckling stress of water-filled CNTs. The divergent effect of the electric field is attributed to the competition between the axial and circumferential pressures induced by polar water molecules. Furthermore, it is notable that the transverse electric field could result in an internal pressure with elliptical distribution, which is an effective and convenient approach to apply nonuniform pressure on nanochannels. Based on pre-strained water-filled CNTs, we designed a nanoscale trigger with an evident and rapid height change initiated by switching the direction of the electric field. The reported finding provides a foundation for an electricity-controlled property of nanochannels filled with polar molecules and provides an insight into the design of nanoscale functional devices.
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http://dx.doi.org/10.1088/1361-6528/aa98eeDOI Listing
January 2018

Tilt, Decentration, and Internal Higher-Order Aberrations of Sutured Posterior-Chamber Intraocular Lenses in Patients with Open Globe Injuries.

J Ophthalmol 2017 29;2017:3517461. Epub 2017 Oct 29.

Department of Ophthalmology, Eye, Ear, Nose, and Throat Hospital of Fudan University, 83 Fenyang Road, Shanghai 200031, China.

Purpose: To evaluate the tilt, decentration, and internal higher-order aberrations (HOAs) of sutured posterior-chamber intraocular lenses (IOLs) in patients with open globe injuries.

Methods: 46 consecutive patients (47 eyes) who underwent transsclerally sutured IOL implantation were enrolled in this prospective cohort study. Nineteen eyes had a history of open globe injury. The tilt and decentration of the IOLs and the visual quality were measured 1 month after surgery.

Results: The horizontal tilt and decentration of the IOLs in the open-globe-injury group were significantly higher than those in the control group (both < 0.05). In the open-globe-injury group, the horizontal decentration was significantly greater in the limbus-sclera-involved group ( = 11) than in the only-cornea-involved group ( = 8, = 0.040). The internal coma, 3rd-order, and total HOA values at pupil sizes of 4 mm ( = 0.006) and 6 mm ( = 0.013) were significantly higher in the open-globe-injury group than in the controls. Consequently, the optical quality data for the modulation transfer function and the Strehl ratio (all < 0.05) were significantly poorer in the open-globe-injury group.

Conclusions: Open globe injuries damage the structural integrity of the eyeball, resulting in more-misaligned sutured IOLs and poorer visual quality.
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http://dx.doi.org/10.1155/2017/3517461DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5682077PMC
October 2017

Receptor-Mediated Endocytosis of Nanoparticles: Roles of Shapes, Orientations, and Rotations of Nanoparticles.

J Phys Chem B 2018 01 19;122(1):171-180. Epub 2017 Dec 19.

International Research Center for Computational Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Faculty of Vehicle Engineering and Mechanics, Dalian University of Technology , Dalian 116024, P. R. China.

A complete understanding of the interactions between nanoparticles (NPs) and the cell membrane is essential for the potential biomedical applications of NPs. The rotation of the NP during the cellular wrapping process is of great biological significance and has been widely observed in experiments and simulations. However, the underlying mechanisms of the rotation and their potential influences on the wrapping behavior are far from being fully understood. Here, by coupling the rotation of the NP with the diffusion of the receptors, we set up a model to theoretically investigate the wrapping pathway and the internalization rate of the rotatable NP in the receptor-mediated endocytosis. Based on this model, it is found that the endocytosis proceeds through the symmetric-asymmetric or asymmetric-symmetric-asymmetric wrapping pathway due to the bending and membrane tension competition induced rotation of NP. In addition, we show that the wrapping rate in the direction that the wrapping proceeds can be largely accelerated by the rotation. Moreover, the time to fully wrap the NP depends not only on the size and shape of the NP but also on its rotation and initial orientation. These results reveal the roles of the shape, rotation, and initial orientation of the NP on the receptor-mediated endocytosis and may provide guidelines for the design of NP-based drug delivery systems.
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http://dx.doi.org/10.1021/acs.jpcb.7b09619DOI Listing
January 2018

Hetero interface and twin boundary mediated strengthening in nano-twinned Cu//Ag multilayered materials.

Nanotechnology 2017 Oct 7;28(41):415705. Epub 2017 Aug 7.

International Research Center for Computational Mechanics, State Key Laboratory of Structure Analysis for Industrial Equipment, Department of Engineering Mechanics, Faculty of Vehicle Engineering and Mechanics, Dalian University of Technology, Dalian 116024, People's Republic of China.

Based on molecular dynamics simulations, tensile mechanical properties and plastic deformation mechanisms of nano-twinned Cu//Ag multilayered materials are investigated in this work. Simulation results show that, due to the stronger strengthening effect of the twin boundary than both the cube-on-cube and hetero-twin interfaces between Cu and Ag layers, the strength increases with the increase of layer thickness for nano-twinned Cu//Ag multilayered materials with a constant twin spacing, while it decreases with the increase of layer thickness for twin-free ones. The strength of hetero-twin multilayered materials is higher than that of the cube-on-cube samples due to the different hetero interfacial configurations. The confined layer slip of dislocation is found to be the dominant plastic deformation mechanism for twin-free hetero-twin multilayered materials and the strength versus twin spacing in nano-twinned samples follows the conventional Hall-Petch relationship. These findings will shed light on the understanding of the plastic deformation mechanisms and the fabrication of high strength nano-twinned multilayered metallic materials.
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http://dx.doi.org/10.1088/1361-6528/aa847cDOI Listing
October 2017

Association of alpha A-crystallin polymorphisms with susceptibility to nuclear age-related cataract in a Han Chinese population.

BMC Ophthalmol 2017 Jul 29;17(1):133. Epub 2017 Jul 29.

Department of Ophthalmology, Eye and ENT Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, People's Republic of China.

Background: Alpha A-crystallin (CRYAA) is considered critical for the maintenance of lens transparency and is related to the pathogenesis of age-related cataracts (ARCs), especially the nuclear subtype. As the 5' untranslated region (5' UTR) modulates gene expression, the purpose of current study was to investigate whether single nucleotide polymorphisms (SNPs) in the 5' UTR of CRYAA were associated with susceptibility to ARC in a Han Chinese population and to clarify the mechanism of this association.

Methods: SNPs in the 5' UTR (-1 to -1000) of CRYAA were identified in 243 nuclear ARC patients and 263 controls using polymerase chain reaction and DNA sequencing. Allele and genotype frequencies were calculated and compared between two groups. Haploview 4.2 was used to calculate the linkage disequilibrium index, and the SHEsis analysis platform was used to infer haplotype construction. A dual-luciferase reporter gene assay was used for transcription of CRYAA in the presence of a protective haplotype with individual SNP alteration, Chromatin immunoprecipitation (ChIP) was employed to determine whether SNPs regulated CRYAA expression by altering the binding affinity of transcription factors.

Results: Three polymorphisms were identified in the 5' UTR of CRYAA: rs3761381 (P = 0.000357, odds ratio [OR] = 1.837), rs13053109 (P = 0.788, OR = 1.086), and rs7278468 (P = 0.00136, OR = 0.652). The haplotype C-G-T (P = 0.0014, OR = 1.536) increased the risk of nuclear ARC, whereas the haplotype T-G-G (P = 0.00029, OR = 0.535) decreased the risk. The haplotype C-G-T decreased CRYAA transcription through rs7278468, which is located in the binding site of specificity protein 1 (Sp1). Furthermore, the G allele of rs7278468 increased CRYAA transcription by enhancing the binding affinity of Sp1.

Conclusions: These data indicate that the CRYAA polymorphism is a genetic marker of inter-individual differences in the risk of nuclear ARC.
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http://dx.doi.org/10.1186/s12886-017-0529-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5534246PMC
July 2017

Vibration-Induced Property Change in the Melting and Solidifying Process of Metallic Nanoparticles.

Nanoscale Res Lett 2017 Dec 26;12(1):308. Epub 2017 Apr 26.

International Research Center for Computational Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian, 116024, People's Republic of China.

Tuning material properties in the 3-D printing process of metallic parts is a challenging task of current interests. Much research has been conducted to understand the effects of controlling parameters such as the particle geometry (size and shape), heating, and cooling ways on the outcome of the printing process. However, nothing has been done to explore the system vibration effect. This letter reports our findings on the vibration-induced property change in the melting and solidifying process of silver nanoparticles with the use of molecular dynamics simulation. We find that the increase of system vibration magnitude would increase the number fraction of disordered atoms, which in turn changes the nanostructure of solidified products. For a given system vibration magnitude, the number fraction of disordered atoms reaches the maximum around the system natural frequency so that the stiffness of solidified products becomes the minimum. Since this trend is not affected by the system size, the above findings reveal a feasible path toward the real-time tuning of material properties for advancing additive manufacturing.
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http://dx.doi.org/10.1186/s11671-017-2085-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5406317PMC
December 2017

Risk factors for and diagnosis of pseudophakic cystoid macular edema after cataract surgery in diabetic patients.

J Cataract Refract Surg 2017 02;43(2):207-214

From the Department of Ophthalmology (Yang, Cai, Sun, Ye, Fan, Zhang, W. Lu, Y. Lu), Eye and ENT Hospital of Fudan University, and the Myopia Key Laboratory of Health PR China (Yang, Cai, Sun, Ye, Fan, Zhang, Y. Lu), Shanghai, China. Electronic address:

Purpose: To evaluate the risk factors and potential diagnostic criteria for pseudophakic cystoid macular edema (CME) in diabetic patients after phacoemulsification.

Setting: Department of Ophthalmology, Eye and ENT Hospital of Fudan University, Shanghai, China.

Design: Prospective nonrandomized study.

Methods: Diabetic patients were followed for up to 6 months after cataract surgery and examined to evaluate their foveal thickness, macular sensitivity, and corrected distance visual acuity. Multiple statistical analyses were performed to determine risk factors and diagnostic criteria for pseudophakic CME.

Results: The duration, type of diabetes, stage of diabetic retinopathy, nuclear opalescence grading, glycosylated hemoglobin A (HbA), and ultrasound time were correlated with the change in foveal thickness and macular sensitivity after cataract surgery. Unsupervised data analysis showed 3 groups of patients as follows: nonpseudophakic CME, level 1 pseudophakic CME, and level 2 pseudophakic CME. Subclinical level 1 patients had a 30% to 40% increase in foveal thickness 1 month postoperatively, while level 2 patients had at least a 40% increase in foveal thickness and a 20% decrease in macular sensitivity. The incidence of clinical pseudophakic CME was 3.2% in diabetic patients as per the diagnostic criteria. The change in macular sensitivity was more consistent and correlated with foveal thickness.

Conclusions: The duration, severity, type of diabetes, hardness of the lens, and HbA were risks for pseudophakic CME in diabetic patients after cataract surgery. A 40% or more increase in foveal thickness and 20% or more decrease in macular sensitivity offer an objective and reliable diagnostic standard to report pseudophakic CME in diabetics.
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http://dx.doi.org/10.1016/j.jcrs.2016.11.047DOI Listing
February 2017

Free-end adaptive nudged elastic band method for locating transition states in minimum energy path calculation.

J Chem Phys 2016 Sep;145(9):094104

State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Faculty of Vehicle Engineering and Mechanics, Dalian University of Technology, Dalian 116024,People's Republic of China.

A free-end adaptive nudged elastic band (FEA-NEB) method is presented for finding transition states on minimum energy paths, where the energy barrier is very narrow compared to the whole paths. The previously proposed free-end nudged elastic band method may suffer from convergence problems because of the kinks arising on the elastic band if the initial elastic band is far from the minimum energy path and weak springs are adopted. We analyze the origin of the formation of kinks and present an improved free-end algorithm to avoid the convergence problem. Moreover, by coupling the improved free-end algorithm and an adaptive strategy, we develop a FEA-NEB method to accurately locate the transition state with the elastic band cut off repeatedly and the density of images near the transition state increased. Several representative numerical examples, including the dislocation nucleation in a penta-twinned nanowire, the twin boundary migration under a shear stress, and the cross-slip of screw dislocation in face-centered cubic metals, are investigated by using the FEA-NEB method. Numerical results demonstrate both the stability and efficiency of the proposed method.
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http://dx.doi.org/10.1063/1.4962019DOI Listing
September 2016

Controllable deformation of salt water-filled carbon nanotubes using an electric field with application to molecular sieving.

Nanotechnology 2016 Aug 23;27(31):315702. Epub 2016 Jun 23.

State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Faculty of Vehicle Engineering and Mechanics, Dalian University of Technology, Dalian 116024, People's Republic of China.

Precisely controlling the deformation of carbon nanotubes (CNTs) has practical application in the development of nanoscale functional devices, although it is a challenging task. Here, we propose a novel method to guide the deformation of CNTs through filling them with salt water and applying an electric field. With the electric field along the axial direction, the height of CNTs is enlarged by the axial electric force due to the internal ions and polar water molecules. Under an electric field with two mutually orthogonal components, the transverse electric force could further induce the bending deformation of CNTs. Based on the classical rod and beam theories, two mechanical models are constructed to verify and quantitatively describe the relationships between the tension and bending deformations of CNTs and the electric field intensity. Moreover, by means of the electric field-driven tension behavior of CNTs, we design a stretchable molecular sieve to control the flow rate of mixed gas and collect a single high-purity gas. The present work opens up new avenues in the design and fabrication of nanoscale controlling units.
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http://dx.doi.org/10.1088/0957-4484/27/31/315702DOI Listing
August 2016

Distribution of gene mutations in sporadic congenital cataract in a Han Chinese population.

Mol Vis 2016 8;22:589-98. Epub 2016 Jun 8.

Key Laboratory of myopia,Ministry of Health, Shanghai, China; Department of Ophthalmology, Eye & ENT Hospital of Fudan University, Shanghai, China.

Purpose: This study aimed to investigate the genetic effects underlying non-familial sporadic congenital cataract (SCC).

Methods: We collected DNA samples from 74 patients with SCC and 20 patients with traumatic cataract (TC) in an age-matched group and performed genomic sequencing of 61 lens-related genes with target region capture and next-generation sequencing (NGS). The suspected SCC variants were validated with MassARRAY and Sanger sequencing. DNA samples from 103 healthy subjects were used as additional controls in the confirmation examination.

Results: By filtering against common variants in public databases and those associated with TC cases, we identified 23 SCC-specific variants in 17 genes from 19 patients, which were predicted to be functional. These mutations were further confirmed by examination of the 103 healthy controls. Among the mutated genes, CRYBB3 had the highest mutation frequency with mutations detected four times in four patients, followed by EPHA2, NHS, and WDR36, the mutation of which were detected two times in two patients. We observed that the four patients with CRYBB3 mutations had three different cataract phenotypes.

Conclusions: From this study, we concluded the clinical and genetic heterogeneity of SCC. This is the first study to report broad spectrum genotyping for patients with SCC.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4896834PMC
January 2018

Disturbance characteristics of half-selected cells in a cross-point resistive switching memory array.

Nanotechnology 2016 May 20;27(21):215204. Epub 2016 Apr 20.

Institute of Microelectronics, Peking University, Beijing 100871, People's Republic of China.

Disturbance characteristics of cross-point resistive random access memory (RRAM) arrays are comprehensively studied in this paper. An analytical model is developed to quantify the number of pulses (#Pulse) the cell can bear before disturbance occurs under various sub-switching voltage stresses based on physical understanding. An evaluation methodology is proposed to assess the disturb behavior of half-selected (HS) cells in cross-point RRAM arrays by combining the analytical model and SPICE simulation. The characteristics of cross-point RRAM arrays such as energy consumption, reliable operating cycles and total error bits are evaluated by the methodology. A possible solution to mitigate disturbance is proposed.
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http://dx.doi.org/10.1088/0957-4484/27/21/215204DOI Listing
May 2016

Twin Boundaries merely as Intrinsically Kinematic Barriers for Screw Dislocation Motion in FCC Metals.

Sci Rep 2016 Mar 10;6:22893. Epub 2016 Mar 10.

State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Faculty of Vehicle Engineering and Mechanics, Dalian University of Technology, Dalian 116024, P. R. China.

Metals with nanoscale twins have shown ultrahigh strength and excellent ductility, attributed to the role of twin boundaries (TBs) as strong barriers for the motion of lattice dislocations. Though observed in both experiments and simulations, the barrier effect of TBs is rarely studied quantitatively. Here, with atomistic simulations and continuum based anisotropic bicrystal models, we find that the long-range interaction force between coherent TBs and screw dislocations is negligible. Further simulations of the pileup behavior of screw dislocations in front of TBs suggest that screw dislocations can be blocked kinematically by TBs due to the change of slip plane, leading to the pileup of subsequent dislocations with the elastic repulsion actually from the pinned dislocation in front of the TB. Our results well explain the experimental observations that the variation of yield strength with twin thickness for ultrafine-grained copper follows the Hall-Petch relationship.
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http://dx.doi.org/10.1038/srep22893DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4790633PMC
March 2016

An analytic model for accurate spring constant calibration of rectangular atomic force microscope cantilevers.

Sci Rep 2015 Oct 29;5:15828. Epub 2015 Oct 29.

State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China.

Spring constant calibration of the atomic force microscope (AFM) cantilever is of fundamental importance for quantifying the force between the AFM cantilever tip and the sample. The calibration within the framework of thin plate theory undoubtedly has a higher accuracy and broader scope than that within the well-established beam theory. However, thin plate theory-based accurate analytic determination of the constant has been perceived as an extremely difficult issue. In this paper, we implement the thin plate theory-based analytic modeling for the static behavior of rectangular AFM cantilevers, which reveals that the three-dimensional effect and Poisson effect play important roles in accurate determination of the spring constants. A quantitative scaling law is found that the normalized spring constant depends only on the Poisson's ratio, normalized dimension and normalized load coordinate. Both the literature and our refined finite element model validate the present results. The developed model is expected to serve as the benchmark for accurate calibration of rectangular AFM cantilevers.
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http://dx.doi.org/10.1038/srep15828DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4625185PMC
October 2015

Wrapping of nanoparticles by the cell membrane: the role of interactions between the nanoparticles.

Soft Matter 2015 Nov;11(44):8674-83

State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Faculty of Vehicle Engineering and Mechanics, Dalian University of Technology, Dalian 116024, P. R. China.

A fundamental understanding of the interactions between nanoparticles (NPs) and the cell membrane is essential to improve the performance of the NP-based biomedical applications and assess the potential toxicity of NPs. Despite the great progress in understanding the interaction between individual NP and the membrane, little is known about the interaction between multiple NPs and the membrane. In this work, we investigate the wrapping of two parallel elongated NPs by the membrane, taking the NP-NP electrostatic interaction and van der Waals (vdW) interaction into consideration. Three types of NPs, namely the rigid NPs with circular and elliptic cross-sections and the deformable NPs, are systematically investigated. The results show that the electrostatic interaction would enhance the tendency of the independent wrapping and inhibit the rotation of the elongated and equally charged NPs with elliptic cross-sections. Under the vdW interaction, the competition of the NP-NP adhesion and the membrane elastic energies with the NP-membrane adhesion energy leads the NPs to be wrapped cooperatively or independently. For the system with elongated NPs with elliptic cross-sections, the NPs are more likely to be wrapped independently as the shapes become more anisotropic and the NPs would rotate to contact each other with the flat sides in the cooperative wrapping configuration. Moreover, the soft NPs are more likely to be wrapped cooperatively compared with the stiff NPs. These results may provide guidelines to control the internalization pathway of NPs and improve the efficiency of NP-based drug delivery systems.
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http://dx.doi.org/10.1039/c5sm01460cDOI Listing
November 2015

LOXL1 Hypermethylation in Pseudoexfoliation Syndrome in the Uighur Population.

Invest Ophthalmol Vis Sci 2015 Sep;56(10):5838-43

Department of Ophthalmology Eye and ENT Hospital of Fudan University, Shanghai, China.

Purpose: High prevalence of pseudoexfoliation syndrome (PEX) occurs in the Uighur population. This study investigated DNA methylation of the lysyloxidase-like 1 (LOXL1) gene in Uighur PEX patients with cataracts.

Methods: The research involved 10 lens capsule specimens from Uighur PEX patients with cataracts and 10 lens capsule specimens from Uighur control patients with age-related cataract (ARC) alone. All specimens were freshly collected during cataract surgery. Methylation status of the CpG islands was analyzed using pyrosequencing. The mRNA levels of LOXL1 were evaluated by quantitative real-time PCR, and protein levels were evaluated by Western blot assay.

Results: For all the six chosen CpG islands of the LOXL1 gene promoter, hypermethylation was found in the PEX with cataracts compared to the age-matched ARC group. At the same time, the expression level of LOXL1 mRNA was significantly reduced in the PEX with cataracts group than that in the ARC group, and the expression level of the LOXL1 protein product demonstrated a similar tendency.

Conclusions: The susceptible PEX gene LOXL1 undergoes DNA hypermethylation in its promoter region in Uighur PEX with cataracts patients. This indicates that epigenetic regulation might play roles in PEX pathogenesis.
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http://dx.doi.org/10.1167/iovs.15-16618DOI Listing
September 2015

Proteomic analysis of aqueous humor proteins associated with cataract development.

Clin Biochem 2015 Dec 8;48(18):1304-9. Epub 2015 Aug 8.

Department of Ophthalmology, Eye & ENT Hospital of Fudan University, Key Laboratory of Myopia of State Health Ministry, and Key Laboratory of Visual Impairment and Restoration of Shanghai, No. 83 Fenyang Road, Shanghai 200031, China. Electronic address:

Background: Cataract is one of the most common eye diseases that can further cause blindness. Discovering susceptibility factors contributing to cataract development is helpful in identifying predisposed patients and improving treatment efficacy. Although proteomics technology has been used in study of protein markers related to eye diseases, few were on studies of cataract development.

Methods: To explore cataract-associated susceptibility factors in aqueous humor (AH), a quantitative proteomics study using the iTRAQ methodology was employed to compare AH protein profiles between high myopia patients & controls, glaucoma surgery patients & controls, and vitrectomy surgery patients & controls, respectively.

Results: A total of 445 AH proteins were identified, and 210 proteins were differentially expressed between myopia patients and controls, 262 proteins were differentially expressed between glaucoma surgery patients and controls, and 161 proteins were differentially expressed between vitrectomy surgery patients and controls. Among the 445 identified proteins, 77 were considered to be cataract-associated, and 5 of the 77 proteins were randomly selected and confirmed by ELISA assay. Biological functions of these 77 proteins were annotated by GO/pathways analysis. Additionally, 17 proteins were found to be involved in protein-protein interaction networks, 5 of which were associated with nervous system disease and eye diseases including cataract.

Conclusions: The identified candidate protein biomarkers associated with cataract development may lead to more insights into the underlying mechanisms of cataract disease.
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http://dx.doi.org/10.1016/j.clinbiochem.2015.08.006DOI Listing
December 2015
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