- [Magnetic resonance imaging features of tear outflow and structural changes of the lacrimal sac and nasolacrimal duct in normal subjects with eyes closed]. [Journal Article]
- ZYZhonghua Yan Ke Za Zhi 2018 Mar 11; 54(3):205-211
- Objective: To investigate the static and dynamic features of the normal lacrimal sac (LS)-nasolacrimal duct (NLD), and find out if tear flows while the subject is in supine position with eyes closed...
Objective: To investigate the static and dynamic features of the normal lacrimal sac (LS)-nasolacrimal duct (NLD), and find out if tear flows while the subject is in supine position with eyes closed. Methods: Cross-sectional study. Healthy volunteers and patients whose head were examined by MRI in Guangdong Provincial Hospital of Integrated Traditional Chinese and Western Medicine with normal LS-NLD were recruited. The normal lacrimal ducts of the candidates were scanned, while candidates remained in supine position, by static or dynamic imaging procedures with a 1.5T MRI system, which adopted the thinnest slice thickness, consecutive sections (no spacing) and two scanning planes (axial and coronal planes of LS-NLD). The static and dynamic imaging procedures were done in June and July 2014 and October 2015, respectively. The static imaging was performed with conventional T(2)WI, contrast-enhanced 3D FIESTA-C, contrast-enhanced T(1)WI and heavy T(2)WI pulse sequences under normal physiological condition, and 104 eyes with normal LS-NLD from 39 patients and 13 healthy volunteers (21 male and 31 female) aged 10 to 75 years were scanned with the static procedure. The dynamic imaging was done with heavy T(2)WI pulse sequence. The coronal dynamic imaging was done only after 0.9% NaCl was instilled in the conjunctival sacs, and 20 eyes with normal LS-NLD of 10 volunteers (6 male and 4 female) aged 23 to 53 years were scanned with the coronal dynamic procedure. The axial dynamic imaging was done under normal physiological condition and after 0.9% NaCl was instilled in the conjunctival sacs respectively, and 20 eyes with normal LS-NLD of 10 volunteers (8 male and 2 female) aged 20 to 40 years were scanned with the axial dynamic procedure. The incidences on the axial dynamic imaging under the two conditions were compared with χ(2) test. Results: A total of 104 eyes with normal LS-NLD (52 candidates) were scanned with the static imaging sequences. In all LS-NLDs, an indentation located at the posterior-lateral side wall of the junction of LS-NLD was discovered, and its depth was variable. In 28.8% (30/104) of LS, 64.4% (67/104) of the junctions and 22.1% (23/104) of NLD, lumens were closed. As for the coronal dynamic imaging (20 eyes with normal LS-NLD in 10 subjects), segmental tear transit was observed in 15/20 of NLD. As for the axial dynamic imaging (20 eyes with normal LS-NLD in 10 subjects), after 0.9% NaCl was instilled, dynamic changing of their lumen size was revealed in 17/20 of LS-NL and the occurrence rate of the lumen size changing (29.3%, 94/321, the number of the axial slices with lumen changes/total number of the axial slices imaged) was higher than that (16.4%,52/317) under normal physiological condition. The difference between the two rates was statistically significant (χ(2)=14.993, P<0.001). LS contained more tear than NLD. Conclusion: While the candidates are in supine position with eyes closed (absolutely no blinking), an indentation is at the posterior-lateral side wall of the junction of LS-NLD, and there are autonomous, segmental lumen open-close actions in normal LS-NLD and tear transit in their lumens. (Chin J Ophthalmol, 2018, 54: 205-211).
- Sensitivity of Diagnostic Tests for Dry Eye in Patients with Blepharospasm. [Journal Article]
- ACActa Clin Croat 2017; 56(3):375-381
- The aim of the study was to evaluate diagnostic tests for keratoconjunctivitis sicca (Schirmer test, tear break-up time (TBUT) test, and corneal staining with fluorescein and lissamine green dye) in ...
The aim of the study was to evaluate diagnostic tests for keratoconjunctivitis sicca (Schirmer test, tear break-up time (TBUT) test, and corneal staining with fluorescein and lissamine green dye) in patients with blepharospasm. This prospective study included 60 female patients older than 40 with blepharospasm, divided into two groups according to clinical symptoms. For fluorescein test, the surface under the ROC curve was 1.0 with standard error (SE) 0 and 95% confidence interval (95% CI) 0.940-1.0; for Schirmer test, the surface under the ROC curve was 0.817 with SE 0.0555 and 95% CI 0.696-0.905; for lissamine green test, the surface under the ROC curve was 0.813 with SE 0.056 and 95% CI 0.691-0.902; and for TBUT test, the surface under the ROC curve was 0.772 with SE 0.061 and 95% CI 0.645-0.870. According to the results of ROC curve, which determines the sensitivity and specificity of normal values, comparison of diagnostic tests for keratoconjunctivitis sicca used in this study showed that fluorescein test had the best sensitivity and specificity. Schirmer test should be avoided in patients with blepharospasm because its results are influenced by frequent blinking and are not appropriate for study interpretation. Despite the pathologic values of TBUT test (numerically), this test is still acceptable for patients with blepharospasm because its interval takes more time than the interval between two blinks.
- Chemical Structure, Ensemble and Single-Particle Spectroscopy of Thick-Shell InP-ZnSe Quantum Dots. [Journal Article]
- NLNano Lett 2018 Feb 14; 18(2):709-716
- Thick-shell (>5 nm) InP-ZnSe colloidal quantum dots (QDs) grown by a continuous-injection shell growth process are reported. The growth of a thick crystalline shell is attributed to the high temperat...
Thick-shell (>5 nm) InP-ZnSe colloidal quantum dots (QDs) grown by a continuous-injection shell growth process are reported. The growth of a thick crystalline shell is attributed to the high temperature of the growth process and the relatively low lattice mismatch between the InP core and ZnSe shell. In addition to a narrow ensemble photoluminescence (PL) line-width (∼40 nm), ensemble and single-particle emission dynamics measurements indicate that blinking and Auger recombination are reduced in these heterostructures. More specifically, high single-dot ON-times (>95%) were obtained for the core-shell QDs, and measured ensemble biexciton lifetimes, τ2x ∼ 540 ps, represent a 7-fold increase compared to InP-ZnS QDs. Further, high-resolution energy dispersive X-ray (EDX) chemical maps directly show for the first time significant incorporation of indium into the shell of the InP-ZnSe QDs. Examination of the atomic structure of the thick-shell QDs by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) reveals structural defects in subpopulations of particles that may mitigate PL efficiencies (∼40% in ensemble), providing insight toward further synthetic refinement. These InP-ZnSe heterostructures represent progress toward fully cadmium-free QDs with superior photophysical properties important in biological labeling and other emission-based technologies.
- Content validation of behaviours and autonomic responses for the assessment of pain in critically ill adults with a brain injury. [Journal Article]
- ACAust Crit Care 2018; 31(3):145-151
- CONCLUSIONS: Facial expressions, movements towards the pain site, and vocalisation of pain were the most relevant pain-related behaviours rated by critical care clinicians. The relevance of some behaviours (e.g., moaning and verbal complaints of pain) varied across LOCs, thereby calling forth adaptations of behavioural pain scales to allow for interpretation in the context of a patient's LOC and ability to express specific behaviours.
- Influence of exercise on the structure of the anterior chamber of the eye. [Journal Article]
- AOActa Ophthalmol 2018; 96(2):e247-e253
- CONCLUSIONS: The blinking rate did not change significantly during exercise, while ACA, AOD500 and TISA500 increased after exercise. Exercise also induced or increased IC. These changes in anterior chamber structure were only associated with exercise, but not with the postexercise change in PD or IOP.
- Shell thickness effects on quantum dot brightness and energy transfer. [Journal Article]
- NNanoscale 2017 Nov 02; 9(42):16446-16458
- Heterostructured core/shell quantum dots (QDs) are prized in biomedical imaging and biosensing applications because of their bright, photostable emission and effectiveness as Förster resonance energy...
Heterostructured core/shell quantum dots (QDs) are prized in biomedical imaging and biosensing applications because of their bright, photostable emission and effectiveness as Förster resonance energy transfer (FRET) donors. However, as nanomaterials chemistry has progressed beyond traditional QDs to incorporate new compositions, ultra-thick shells, and alloyed structures, few of these materials have had their optical properties systematically characterized for effective application. For example, thick-shelled QDs, also known as 'giant' QDs (gQDs) are useful in single-particle tracking microscopy because of their reduced blinking, but we know only that CdSe/CdS gQDs are qualitatively brighter than thin-shelled CdSe/CdS in aqueous media. In this study, we quantify the impact of shell thickness on the nanoparticle molar extinction coefficient, quantum yield, brightness, and effectiveness as a FRET donor for CdSe/xCdS core/shell and CdSe/xCdS/ZnS core/shell/shell QDs, with variable thicknesses of the CdS shell (x). Molar extinction coefficients up to three orders of magnitude higher than conventional dyes and forty-fold greater than traditional QDs are reported. When thick CdS shells are combined with ZnS capping, quantum yields following thiol ligand exchange reach nearly 40%-5-10× higher than either the commercially available QDs or gQDs without ZnS caps treated the same way. These results clearly show that thick CdS shells and ZnS capping shells work in concert to provide the brightest possible CdSe-based QDs for bioimaging applications. We demonstrate that thicker shelled gQDs are over 50-fold brighter than their thin-shelled counterparts because of significant increases in their absorption cross-sections and higher quantum yield in aqueous milieu. Consistent with the point-dipole approximation commonly used for QD-FRET, these data show that thick shells contribute to the donor-acceptor distance, reducing FRET efficiency. Despite the reduction in FRET efficiency, even the thickest-shell gQDs exhibited energy transfer. Through this systematic study, we elucidate the tradeoffs between signal output, which is much higher for the gQDs, and FRET efficiency, which decreases with shell thickness. This study serves as a guide to nanobiotechnologists striving to use gQDs in imaging and sensing devices.
- Visual Fatigue Induced by Viewing a Tablet Computer with a High-resolution Display. [Journal Article]
- KJKorean J Ophthalmol 2017; 31(5):388-393
- CONCLUSIONS: Visual fatigue and discomfort were significantly induced by viewing smart mobile devices, even though the devices were equipped with state-of-the-art display technology.
- Clinical relationship of meibometry with ocular symptoms and tear film stability. [Journal Article]
- CLCont Lens Anterior Eye 2017; 40(6):408-416
- CONCLUSIONS: Meibometer MB550 can discriminate asymptomatic from dry eye symptomatic patients. Furthermore, there is a relationship between meibometry and the tear film stability.
- A Single-Channel EOG-Based Speller. [Journal Article]
- ITIEEE Trans Neural Syst Rehabil Eng 2017; 25(11):1978-1987
- Electrooculography (EOG) signals, which can be used to infer the intentions of a user based on eye movements, are widely used in human-computer interface (HCI) systems. Most existing EOG-based HCI sy...
Electrooculography (EOG) signals, which can be used to infer the intentions of a user based on eye movements, are widely used in human-computer interface (HCI) systems. Most existing EOG-based HCI systems incorporate a limited number of commands because they generally associate different commands with a few different types of eye movements, such as looking up, down, left, or right. This paper presents a novel single-channel EOG-based HCI that allows users to spell asynchronously by only blinking. Forty buttons corresponding to 40 characters displayed to the user via a graphical user interface are intensified in a random order. To select a button, the user must blink his/her eyes in synchrony as the target button is flashed. Two data processing procedures, specifically support vector machine (SVM) classification and waveform detection, are combined to detect eye blinks. During detection, we simultaneously feed the feature vectors extracted from the ongoing EOG signal into the SVM classification and waveform detection modules. Decisions are made based on the results of the SVM classification and waveform detection. Three online experiments were conducted with eight healthy subjects. We achieved an average accuracy of 94.4% and a response time of 4.14 s for selecting a character in synchronous mode, as well as an average accuracy of 93.43% and a false positive rate of 0.03/min in the idle state in asynchronous mode. The experimental results, therefore, demonstrated the effectiveness of this single-channel EOG-based speller.
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- Neural mechanisms underlying sound-induced visual motion perception: An fMRI study. [Journal Article]
- APActa Psychol (Amst) 2017; 178:66-72
- Studies of crossmodal interactions in motion perception have reported activation in several brain areas, including those related to motion processing and/or sensory association, in response to multim...
Studies of crossmodal interactions in motion perception have reported activation in several brain areas, including those related to motion processing and/or sensory association, in response to multimodal (e.g., visual and auditory) stimuli that were both in motion. Recent studies have demonstrated that sounds can trigger illusory visual apparent motion to static visual stimuli (sound-induced visual motion: SIVM): A visual stimulus blinking at a fixed location is perceived to be moving laterally when an alternating left-right sound is also present. Here, we investigated brain activity related to the perception of SIVM using a 7T functional magnetic resonance imaging technique. Specifically, we focused on the patterns of neural activities in SIVM and visually induced visual apparent motion (VIVM). We observed shared activations in the middle occipital area (V5/hMT), which is thought to be involved in visual motion processing, for SIVM and VIVM. Moreover, as compared to VIVM, SIVM resulted in greater activation in the superior temporal area and dominant functional connectivity between the V5/hMT area and the areas related to auditory and crossmodal motion processing. These findings indicate that similar but partially different neural mechanisms could be involved in auditory-induced and visually-induced motion perception, and neural signals in auditory, visual, and, crossmodal motion processing areas closely and directly interact in the perception of SIVM.