Extensible chip of optofluidic variable optical attenuator.

A core chip of optofluidic variable optical attenuator (VOA) is reported. The chip, with a simple structure, utilizes microfluid and compressed air to regulate the optical attenuation, and it can be expanded to form a number of VOAs by using different microfluidic driving technologies. Three VOAs based on this chip and different driving technologies are introduced. The theoretical and experimental results show that the proposed chip possesses the advantages of large optical attenuation range (> 50dB) and low insertion loss (0.55 dB). Moreover it is a broadband optical device which can be operated in visible and near infrared wavelengths. The proposed chip provides a new method for seeking miniaturized VOAs with good performances, and it is promising to develop a number of different VOAs.

Root tip chromosome karyotype analysis of hyacinth cultivars.

Karyotype analysis in plants helps to reveal the affinity relationships of species and their genetic evolution. The current study aimed to observe chromosome karyotypes and structures of Hyacinthus orientalis. Twenty hyacinth cultivars were introduced from Holland, and their water-cultivated root tips were used as experimental samples. A solution of colchicine (0.02%) and 8-hydroxyquinoline (0.02 M) was used as a 20-h pre-treatment. Subsequently, Carnot I was used for fixation and 45% acetic acid was used for dissociation. The squash method was selected to prepare chromosome spreads for microscopic observation. The basic chromosome number of the hyacinth cultivar was 8, and the number of chromosomes in the diploid, triploid, tetraploid, and aneuploid cultivars was 16, 23, 24, 31, and 32, respectively. The L-type chromosome was predominant in the chromosomal composition. The hyacinth satellite was located on the short arm in numbers equivalent to the ploidy. This satellite is located on the middle-sized chromosome in the fourth group of chromosomes, demonstrating that Hyacinthus has a more primitive evolution than Lilium and Polygonatum. Among 20 hyacinth cultivars, 'Fondant' had the highest level of evolution and a maximum asymmetric coefficient of 61.69%. Moreover, the ratio between the shortest and longest chromosomes in this cultivar was 4.40, and its karyotype was type 2C. This study may elucidate long-term homonym and synonym phenomena. It may also provide a method of cytological identification as well as direct proof of the high outcross compatibility between hyacinth cultivars.

Development of the control system for electron cyclotron resonance heating on J-TEXT tokamak.

A 105 GHz/500 kW/1 s electron cyclotron resonance heating (ECRH) system has been developed on J-TEXT tokamak since 2017. The core component of the ECRH system is a gyrotron manufactured by Gyrotron Complexes Ltd. (GYCOM Ltd.), which generates microwaves of a certain frequency and power. To guarantee safe and stable operation, it is necessary to design a specialized control system. The control system is expected to perform time sequence trigger, protection, signal monitoring, communication, and data acquisition. The hardware is built with real-time processors and data acquisition modules from National Instruments. The control program is realized by LabVIEW. Test results indicate that the control system can commit stable and safe operation of the gyrotron, which guarantees the integrated commissioning tests of the whole ECRH system and ECRH related physics experiments. Under the operation of this control system, the gyrotron can generate microwaves as expected, and the ECRH system is well protected when a fault takes place.

Zinc oxide nanoparticles promotes liver cancer cell apoptosis through inducing autophagy and promoting p53.

OBJECTIVE: Emerging evidence has highlighted the promising potential of the application of Zinc Oxide nanoparticles (nano-ZnO) but the mechanism by how it functions in liver cancer remains elusive. We aimed to explore the effect of nano-ZnO on liver cancer cells. MATERIALS AND METHODS: Liver cancer cells Huh7 cells were transfected with GFP-LC3, and then, treated with DMSO, Sorafenib, and nano-ZnO respectively to set blank group, Sorafenib control group, and nano-ZnO group followed by the analysis of the expression of GFP-LC3, p53, and Caspase by Western blot and RT-qPCR, cell apoptosis and viability by flow cytometry and CCK-8 assay. RESULTS: With a diameter of nano-ZnO 14.13±0.92 nm, the amount of GFP-LC3 protein was increased after treatment of nano-ZnO. Besides, the expressions of GFP-LC3, p53, and Caspase in Sorafenib group and nano-ZnO group were significantly higher than that of control group, while their levels were highest in nano-ZnO group (p<0.05). In nano-ZnO group, the values of D450nm at 24 h, 48h, and 72 h were 0.56±0.06, 0.39±0.05, and 0.22±0.04, respectively, and the apoptotic rate (83.11±2.79%) was significantly lower than that of blank group and control group. CONCLUSIONS: Nano-ZnO induced autophagy, upregulated the p53 gene, and facilitated the apoptosis of liver cancer cells, indicating that nano-ZnO might be a therapeutic approach for the treatment of liver cancer patients.

Changes of anti-ß2 glycoprotein I antibody IgA/G/M, platelet aggregation rate, plasma fibrinogen and d-dimer in guiding venous thrombosis during pregnancy.

OBJECTIVE: This study provides a theoretical basis for the prevention, treatment and diagnosis of venous thrombosis during pregnancy. PATIENTS AND METHODS: Sixty patients with venous thrombosis in gestation period were treated as the research group, including every 30 people in the middle and late pregnancy groups, and the control group randomly selected 33 healthy pregnant women during the same period. The anti-ß2 glycoprotein I antibody IgA/G/M, platelet aggregation rate, plasma fibrinogen, and D-dimer levels were measured in all subjects. RESULTS: Resistance-ß2 glycoprotein I antibody IgA/G/M, platelet aggregation rate, plasma fibrinogen, and compared with the control group, D-dimer levels were significantly increased (p<0.05), but for the middle pregnancy group and late pregnancy group, the difference was not statistically significant (p>0.05). In the control group of pregnant women anti-ß2 glycoprotein Ⅰ antibody IgA/G/M, platelet aggregation rate, plasma fibrinogen, and D-dimer no obvious correlation (p>0.05), Anti-ß2 glycoprotein Ⅰ antibody IgA/G/M, platelet aggregation rate, plasma fibrinogen, D-dimer entry equation are closely related risk factors for venous thrombosis during pregnancy (p<0.05), and D-dimer is the most important. CONCLUSIONS: Vein thrombosis during pregnancy patients anti-ß2 glycoprotein I antibody IgA/G/M, platelet aggregation rate, plasma fibrinogen, and D-dimer in pregnant women group increased significantly compared with the control group, suggesting these above indicators are closely related to Venous thrombosis in pregnant women and associated with the severity of the disease. Vascular endothelial injury plays an important role in phlebothrombosis in gestation period.

A comparison of the effect of carbomer-, cellulose- and mineral oil-based artificial tear formulations.

PURPOSE: To compare the efficacy, safety, and local tolerance between carbomer-based artificial tears, cellulose-, and mineral oil-based artificial tears. METHODS: A randomized, open-label, parallel-group comparative 28-day study was designed for 67 patients who were randomized into three treatment groups. Measurements included the scoring of total subjective symptoms and objective signs, Schirmer-Jones test values, and tear break-up time (BUT) at baseline, and after 2 and 4 weeks of treatment. Safety of study treatment was also assessed. Outcomes measured at baseline and 2 and 4 weeks follow-up included the scoring of total subjective symptoms and objective signs, Schirmer-Jones test values, and tear BUT, subjective assessments, and safety. RESULTS: There were no differences regarding total scores, Schirmer-Jones test, or tear BUT at baseline among these three groups at 2 and 4 weeks. Patients in all three treatment groups experienced a significant improvement from baseline in total scores and Schirmer-Jones test values after treatment. Subjective assessment was better with carbomer-based treatment. CONCLUSIONS: Each artificial tear formulation successfully relieved symptoms and signs of keratoconjunctivitis sicca. The tolerance of carbomer-based artificial tears was comparable to that of cellulose- and mineral oil-based artificial tears.

Fast island phase identification for tearing mode feedback control on J-TEXT tokamak.

A new method to control the tearing mode (TM) in tokamaks has been proposed [Q. Hu and Q. Yu, Nucl. Fusion 56, 034001 (5pp.) (2016)], according to which, the external resonant magnetic perturbation needs to be applied in certain magnetic island phase regions. Therefore, it is very important to identify the helical phase of magnetic islands in real time. The TM in tokamak plasmas is normally rotating and carries magnetic oscillations, which are known as Mirnov oscillations and can be detected by Mirnov probes. When the O-point or X-point of the magnetic island passes through the probe, the signal will experience a zero-crossing. A poloidal Mirnov probe array and a corresponding island phase identification method are presented. A field-programmable gate array is used to provide the magnetic island helical phase in real time by using multichannel zero crossing detection. This system has been developed on the J-TEXT tokamak and works well. This paper introduces the establishment of the fast magnetic island phase identifying system.

Extensive lamellar keratectomy for treatment of nontuberculous mycobacterial keratitis.

PURPOSE: To determine the efficacy of using extensive lamellar keratectomy for treating patients who have nontuberculous mycobacterial keratitis that is unresponsive to medical treatment. METHODS: Nine patients with bacteriologically proven nontuberculous keratitis, who had poor response to medical treatment and whose corneal infiltrate was not deeper than 80% of corneal thickness, were selected for extensive lamellar keratectomy. This procedure was performed freehand to remove all the corneal infiltration visible by operation-microscopic examination, to have a clean stromal bed. RESULTS: Corneal infection was eradicated in seven patients by a single procedure. In the other two patients, the condition was controlled by a second operation. Epithelialization was rapid and complete in all cases within ten days (mean, 4.8 days). Pain relief was dramatic after surgery. Visual acuity after surgery was improved in seven patients, but remained the same in two. There were no complications as a result of the lamellar keratectomy. CONCLUSIONS: Lamellar keratectomy should be considered as a treatment option for patients with nontuberculous mycobacterial keratitis who are unresponsive to medical therapy.

Shewannela putrefaciens endophthalmitis after penetrating keratoplasty.

PURPOSE: To report a case of Shewannela putrefaciens endophthalmitis after penetrating keratoplasty. METHODS: Case report. Vitreous of the recipient and the preservative medium of donor cornea were cultured. RESULTS: Vitreous of the recipient eye and the donor eye corneal preservative medium both grew S putrefaciens. The patient failed to respond to intravitreal, topical, and systemic amikacin and cefotaxime. Vision was lost rapidly. Evisceration was performed. CONCLUSION: Shewannela putrefaciens should be considered as a potential pathogen contaminating donor cornea. Shewannela putrefaciens endophthalmitis is devastating and responds poorly to medical treatment.

Interferon treatment for corneolimbal squamous dysplasia.

PURPOSE: To report a patient with corneolimbal squamous dysplasia successfully treated with interferon therapy. METHODS: A 78-year-old man had a gelatinous and vascularized lesion involving the left cornea and adjacent limbus. Impression cytology studied with periodic acid--Schiff-hematoxylin stain disclosed severe squamous dysplasia. Topical instillation and subconjunctival injection of interferon alpha-2b was instituted. RESULTS: The gelatinous tumor mass involving the cornea and adjacent limbus completely resolved 2 months after interferon treatment. He showed no sign of recurrence during the 10-month follow-up. CONCLUSION: Interferon therapy may be a therapeutic alternative for treating corneolimbal squamous dysplasia.

T-cell malignant lymphoma with conjunctival involvement.

PURPOSE: To report a rare case of T-cell malignant lymphoma involving the conjunctiva. METHODS: A 63-year-old woman had rapid onset of bilateral perilimbal congestion and chemosis. Perilimbal thickening with corneal infiltration developed 20 days later. Computed tomography incidentally disclosed a right maxillary sinus mass. Biopsy specimens from the maxillary sinus mass and the left limbus were subjected to histopathologic examination and immunohistochemical study. RESULTS: T-cell malignant lymphoma of diffuse large cell type, stage IV, was diagnosed. The patient was treated with combination chemotherapy plus 13-cis-retinoic acid and remained in remission 1 1/2 years after diagnosis. CONCLUSION: Conjunctival involvement with T-cell lymphoma may present as episcleritis and chemosis.

Immunohistochemical study of subepithelial haze after phototherapeutic keratectomy.

PURPOSE: Subepithelial haze is a frequent complication and is often the cause of regression after photorefractive keratectomy (PRK). The lack of understanding of this undesirable complication following PRK is in part due to the limited availability of suitable tissues for pathological studies. METHODS: We examined the expression of various extracellular components in the cornea of a 46-year-old man who underwent phototherapeutic keratectomy (PTK) to remove a central corneal scar secondary to trauma. The patient subsequently underwent penetrating keratoplasty. A scar-free region containing an area of slight subepithelial haze adjacent to normal cornea was used for immunohistochemical staining with antibodies directed against cytoskeletal proteins, ie, vimentin, desmin and smooth muscle actin, and the extracellular components, laminin, heparan sulfate, keratan sulfate, and collagen types III, IV, V, and VII. RESULTS: Immunohistochemistry revealed that basal epithelial cells expressed components of basement membrane. The stromal fibroblasts within the haze tissue were labeled by anti-smooth muscle actin antibodies, a characteristic of myofibroblasts, which synthesized and secreted extracellular matrix components that contributed to the formation of the disorganized collagenous matrix and may account for subepithelial haze. CONCLUSIONS: The expression patterns for the cytoskeletal proteins and extracellular components indicated that the formation of subepithelial haze is a process of tissue remodeling, involving both corneal basal epithelial cells and keratocytes during wound repair.

Corneal epithelial recovery following photorefractive keratectomy.

AIMS: To further understand the morphological and functional recovery of corneal epithelium following excimer laser photorefractive keratectomy (PRK). METHODS: The right eyes (group 1) of 15 male, New Zealand white rabbits weighing 2-3 kg underwent PRK. The left eye of each rabbit (group 2) underwent simple mechanical de-epithelialisation and were examined as treated controls. Both eyes of another eight rabbits (group 3) served as untreated controls. All eyes underwent a corneal epithelial permeability study by fluorophotometry at 2, 4, and 8 weeks after surgery. Five animals in groups 1 and 2 were sacrificed at 9, 10, and 12 weeks after surgery. The animals in group 3 were sacrificed at the end of the 12 week experimental period. Both eyes of each sacrificed animal were enucleated immediately and processed for both haematoxylin and eosin stain and electron microscopic study. The electron micrograph was magnified to 14,000x and the extent of hemidesmosome formation was quantified and analysed. RESULTS: The corneal epithelial barrier to sodium fluorescein was subnormal and returned to a normal barrier state 4 weeks after PRK in group 1 whereas it was normal in group 2 throughout the examination period. The extent of hemidesmosome formation was abundant yet subnormal in both groups 1 and 2 up to 12 weeks, when compared with that in group 3. CONCLUSION: The corneal epithelium regained its functional barrier 4 weeks after PRK in rabbits while the extent of hemidesmosome formation was still subnormal 12 weeks after mechanical de-epithelialisation, with or without PRK.

The cornea in young myopic adults.

AIMS: To further understand the effect of refractive error on the corneal dimensions and function. METHODS: Corneal curvature, corneal thickness, and axial length measurements were performed, as well as specular microscopy and fluorophotometry, on patients with various refractive statuses. 216 subjects, mean age 22.2 (SD 4.2) years, were examined. Patients with previous contact lens wear history, external eye diseases, as well as previous ocular surgeries, were excluded. RESULTS: The corneas were flatter in eyes with longer axial length (r = -0.22, p = 0.003). Eyes with more myopic spherical equivalent had longer axial length (r = -0.90, p <0.001) as well as less corneal endothelial density (r = 0.20, p = 0.037). Corneal endothelial density decreased in eyes with longer axial length (r = 0.24, p = 0.019); however, it correlated neither with corneal thickness (r = -0.06, p = 0.59) nor with corneal curvature (r = -0.07, p = 0.52). The corneas had a mean corneal thickness of 533 (SD 29) microm and were thinner in more myopic eyes (r = 0.16, p = 0.021). The corneas tended to be thinner in eyes with longer axial length. However, the correlation did not reach statistical significance (r = -0.11, p = 0.14). Besides, there was no significant correlation between the corneal thickness and the corneal curvature (r = -0.13, p = 0.093) and the endothelial permeability (r = 0.042, p = 0.69). The corneas with higher endothelial density had larger corneal transfer coefficient (r = 0.26, p = 0.024) and higher permeability to fluorescein molecules (r = 0.28, p = 0.014). Nevertheless, the corneal endothelial permeability did not correlate significantly with either the axial length (r = -0.18, p = 0.11) or the degree of myopia (r = 0.12, p = 0.26). CONCLUSION: Changes in the anterior segments as the eyeball elongates in myopia progression included flatter corneal curvature, decreased corneal thickness, as well as decreased endothelial density. These factors should be considered in refractive surgery.

Laser in situ keratomileusis for the correction of myopia and myopic astigmatism.

PURPOSE: To evaluate the efficacy, safety, predictability, and surgically induced astigmatism (SIA) of laser in situ keratomileusis (LASIK) for the correction of myopia and myopic astigmatism. SETTING: Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan. METHODS: This retrospective study comprised 69 eyes that had LASIK to correct myopia and 74 eyes that had LASIK to correct myopic astigmatism. The excimer laser keratectomy was performed using a Summit Apex Plus machine. Refraction, visual acuity, and computerized corneal videokeratography data from the preoperative and postoperative examinations were collected. The astigmatic change was calculated by the Alpins vector analysis method. RESULTS: The preoperative spherical equivalent at the glasses plane in the myopia and myopic astigmatism groups was -8.08 diopters (D) and -9.73 D, respectively. At 6 months, the spherical equivalent and residual corneal astigmatism were -0.25 D and 0.85 D, respectively, in the myopia group and -0.71 D and 0.82 D, respectively, in the myopic astigmatism group. In the myopia group, 88% of eyes were within +/-1.0 D of the intended myopia correction and in the myopic astigmatism group, 85% were within +/-1.0 D of the targeted spherical equivalent and 90% were within +/-1.0 D of the intended astigmatism correction. The uncorrected visual acuity was 20/40 or better in 94.1% of eyes in the myopia group and 92.5% of eyes in the myopic astigmatism group. The SIA magnitude was 0.66 D with the axis randomly distributed in the myopia group. The mean astigmatism correction index was 0.97, the mean magnitude of error was 0.13 D +/- 0.62 (SD), and the mean angle of error was -3.70 +/- 13.73 degrees in the myopic astigmatism group. CONCLUSION: Laser in situ keratomileusis had similar predictability, safety, and efficacy in the treatment of myopia and myopic astigmatism. The astigmatism correction was effective, but the results suggest that subjective astigmatism of less than 1.0 D need not be treated with the Summit Apex Plus laser.

Surgical results of photorefractive keratectomy with different operative modes.

PURPOSE: To compare the predictability, efficacy, and safety of photorefractive keratectomy (PRK) using different operative modes. SETTING: National Taiwan University Hospital, Taipei, Taiwan. METHODS: One hundred fifty-three eyes of 80 patients who had PRK for myopia with a follow-up of at least 6 months were studied. All patients were sequentially assigned to 1 of the following surgical modes: mode 1: PRK with the Summit OmniMed excimer laser; mode 2: PRK with the Summit Apex Plus laser; mode 3: PRK with the Summit Apex Plus laser with anti-central-island pretreatment. RESULTS: Six months after treatment, a homogeneous topographic pattern was seen in 76% of mode 1 eyes, 70% of mode 2 eyes, and 88% of mode 3 eyes. In the low myopia group (< or =-6.0 diopters [D]), the mean residual refractive error was -0.79 D +/- 0.59 (SD) in mode 1, -0.94 +/- 1.02 D in mode 2, and -0.31 +/- 0.42 D in mode 3. In the high myopia group (>-6.0 D), it was -1.93 +/- 1.51 D, -1.54 +/- 0.88 D, and -0.70 +/- 0.81 D, respectively. Uncorrected visual acuity of 20/25 or better was achieved in 81% of mode 1 eyes, 56% of mode 2 eyes, and 89% of mode 3 eyes in the low myopia group, and in 48%, 28%, and 72%, respectively, in the high myopia group. CONCLUSIONS: Photorefractive keratectomy appears to be a predictable and effective procedure. The best results were achieved with the Summit Apex Plus laser with anti-central-island pretreatment, followed by the Summit OmniMed laser. The Summit Apex Plus laser without anti-central-island pretreatment produced less satisfactory results.

Changes in corneal autofluorescence and corneal epithelial barrier function with aging.

Corneal epithelial permeability studies using fluorophotometers were performed on 90 eyes of 51 normal subjects. After recording the autofluorescence of the cornea (AFC) and of the lens (AFL), we applied 20 microliters of 2% sodium fluorescein to the conjunctival sac. The corneal fluorescence 45 min later (F45), which paralleled the corneal epithelial permeability to fluorescein, was measured by fluorophotometer and analyzed. All parameters of the two eyes of each subject correlated well with each other. There was positive correlation between AFL and patient age and between AFC and patient age (r = 0.78, p < 0.001, and r = 0.74, p < 0.001, respectively). The F45 increased exponentially with advancing age (r = 0.67, p < 0.001). The strong correlation between AFC and AFL in each eye (r = 0.79, p < 0.001) indicated corresponding aging processes in both the cornea and the lens. The increase in epithelial permeability with age possibly represents a subclinical breakdown of barrier function, rendering the corneas more vulnerable to insults.

Acyclovir treatment for linear endotheliitis on grafted corneas.

Two patients with previous corneal transplants developed unusual rejection-like episodes of the grafted cornea. Both had a migrating line of keratic precipitates and stromal edema involving both the donor and recipient corneas. Intensive steroid treatment attained little effect, but oral acyclovir treatment dramatically suppressed the disease process. The facts suggest that a virus-related immune mechanism against both the donor and recipient endothelia, rather than simple allograft rejection, may have been responsible for the clinical presentations. Oral acyclovir therapy might be considered in patients with steroid-nonresponsive corneal endotheliitis mimicking allograft rejection.

Nocardia brasiliensis keratitis successfully treated with therapeutic lamellar keratectomy.

A 36-year-old man sustained an indolent keratitis following a minor corneal trauma. Nocardia brasiliensis was isolated from cultures of the corneal scrapings. Fortified topical antibiotics, based on in vitro drug sensitivity testing, were intensively applied for weeks without clinical improvement. The patient underwent therapeutic lamellar keratectomy, which led to a rapid and complete resolution. The site of the keratectomy reepithelialized within 2 days and became a faint subepithelial haze thereafter. The visual acuity improved to 20/20 and there was no evidence of recurrence during the subsequent follow-up. It appears that lamellar keratectomy is a valuable treatment alternative for localized chronic nocardial keratitis.

Changing indications for penetrating keratoplasty in Taiwan from 1987 to 1999.

PURPOSE: To determine the leading indications for penetrating keratoplasty and to identify changing trends in these indications during the past 12 years. METHODS: We retrospectively performed a chart review of the hospital records of all patients undergoing penetrating keratoplasty at the National Taiwan University Hospital during a 12-year period (1987-1999). When possible, the clinical indication was corroborated by the pathologic report. RESULTS: A total of 770 corneal transplants were performed. The leading indications for penetrating keratoplasty. in order of decreasing frequency, were corneal scars (27.9%), regraft (21.0%), acute necrotizing and ulcerative keratitis (17.9%), pseudophakic or aphakic bullous keratopathy (17.6%), Fuchs' dystrophy (4.5%), and keratoconus (2.5%). A trend of increasing frequency of regraft and acute necrotizing and ulcerative keratitis, a decreasing frequency of corneal scar, and an initially decreasing then increasing frequency of pseudophakic and aphakic bullous keratopathy were found during the 12-year study period. Acute necrotizing and ulcerative keratitis was found to be the most frequent indication for regraft. CONCLUSION: In this series, corneal scars, regraft, and acute necrotizing and ulcerative keratitis were the leading indications for penetrating keratoplasty. A changing incidence of pseudophakic and aphakic bullous keratopathy noted during the study period was related to the type of intraocular lens implanted and the method of cataract surgery performed. This study found a comparatively high frequency of acute necrotizing and ulcerative keratitis and an extremely low frequency of keratoconus compared with previous reports.