Lamellar keratoplasty using position-guided surgical needle and M-mode optical coherence tomography

Deep anterior lamellar keratoplasty (DALK) is an emerging surgical technique for the restoration of corneal clarity and vision acuity. The big-bubble technique in DALK surgery is the most essential procedure that includes the air injection through a thin syringe needle to separate the dysfunctional region of the cornea. Even though DALK is a well-known transplant method, it is still challenged to manipulate the needle inside the cornea under the surgical microscope, which varies its surgical yield. Here, we introduce the DALK protocol based on the position-guided needle and M-mode optical coherence tomography (OCT). Depth-resolved 26-gage needle was specially designed, fabricated by the stepwise transitional core fiber, and integrated with the swept source OCT system. Since our device is feasible to provide both the position information inside the cornea as well as air injection, it enables the accurate management of bubble formation during DALK. Our results show that real-time feedback of needle end position was intuitionally visualized and fast enough to adjust the location of the needle. Through our research, we realized that position-guided needle combined with M-mode OCT is a very efficient and promising surgical tool, which also to enhance the accuracy and stability of DALK

Liquid crystal display using combined fringe and in-plane electric fields

A high performance liquid crystal display using combined fringe and in-plane horizontal electric fields is proposed. The strong electric fields cause more liquid crystals to reorient almost in plane above and between the pixel electrodes. As a result, the operation voltage is lower and transmittance is higher than those of fringe field switching and in-plane switching modes, while preserving a wide viewing angle. Such a high performance device is particularly attractive for large panel liquid crystal displays

Accelerated Ulcer Healing and Resistance to Ulcer Recurrence with Gastroprotectants in Rat Model of Acetic Acid-induced Gastric Ulcer

Quality of ulcer healing (QOUH) is defined as ideal ulcer healing featuring with the fine granular ulcer scar, high functional restoration and the resistance to recurrence. This study was designed to compare the rates of QOUH achievement in rat gastric ulcer model between acid suppressant treated group and gastroprotectant treated group accompanied with elucidations of molecular mechanisms. Serosal injection of acetic acids for generating gastric ulcer and intraperitoneal (ip) injection of recombinant interleukin 1-beta (IL-1β) for recurring healed ulcer was done in SD rats. The 72 rats were divided into three groups according to treatment as follows; Group I, no further treatment, Group II, 8 weeks treatment of omeprazole, and Group III, 8 weeks of gastroprotectant treatment. IL-1β was administered for ulcer recurrence after 28 weeks of acetic acid injection. At four weeks after gastric ulcerogenesis, 58.3% (7/12) of active gastric ulcer were converted to healing stage in Group III, but 16.7% (2/12) in Group II and none in Group I, for which significant levels of epidermal growth factor, mucin, and pS2/trefoil peptide1 were contributive to these accelerated healings of Group III. ip injections of rIL-1β (200 µg/kg) at 28 weeks after acetic acid injection led to 100% of ulcer recurrence in Group I and 75.0% in Group II, but only 16.7% of Group III rats showed ulcer recurrence. Significantly attenuated levels of inflammatory cytokines including IL-2, transforming growth factor-alpha (TNF-α), cyclooxygenase-2 (COX-2), nitrotyrosine were responsible for the resistance to ulcer recurrence in Group III. Conclusively, gastroprotectant might be prerequisite in order to achieve ideal QOUH through significant inductions of remodeling

The Association Between Masticatory Function Assessment and Masseter Muscle Thickness in the Elderly

Purpose: Purpose: This study investigated the association between the objective indicator of masticatory function assessment and the masseter muscle thickness (MMT) using ultrasound imaging. Methods: Methods: A total of 99 subjects (males: 24, females: 75, mean age: 76) were analyzed. The maximum bite force (MBF) was measured with a pressure-sensitive sheet and an image scanner. The mixing ability index (MAI) was calculated by image analysis after asking the subjects to chew a wax specimen. The MMT during rest and clenching were obtained with a diagnostic ultrasound system, and the difference in MMT during rest and MMT during clenching was defined as the difference in masseter muscle thickness (DMMT). Multiple regression analysis was performed to determine the independent variables affecting MBF and MAI. Results: Results: The MBF showed correlation with the number of remaining teeth (β=0.346, p=0.002) and DMMT (β=0.251, p=0.011). The MAI correlated with only the number of remaining teeth (β=0.476, p<0.001). Conclusions: Conclusions: The DMMT reflects the state of masseter muscle contraction, and can be used as a predictor as well as the number of teeth when assessing masticatory function.22Nkc

Mucoepidermoid Carcinoma of the Thymus: A Case Report

Mucoepidermoid carcinoma of the thymus is an extremely rare malignant mediastinal neoplasm, and to our knowledge, only 13 cases have been reported. We report a case of mucoepidermoid carcinoma of the thymus that was seen in a 53-yr-old man with right chest pain. Chest CT scan showed a huge, cystic mass having a focal solid portion with direct invasion of the adjacent anterior chest wall and pericardium in the anterior mediastinum. Mucoepidermoid carcinoma of the thymus should be included in the differential diagnosis for masses of the anterior mediastinum associated with extensive cystic changes, although the carcinoma is exceedingly rare

Solution-processed near-infrared Cu(In,Ga)(S,Se)(2) photodetectors with enhanced chalcopyrite crystallization and bandgap grading structure via potassium incorporation

Although solution-processed Cu(In,Ga)(S,Se)(2) (CIGS) absorber layers can potentially enable the low-cost and large-area production of highly stable electronic devices, they have rarely been applied in photodetector applications. In this work, we present a near-infrared photodetector functioning at 980 nm based on solution-processed CIGS with a potassium-induced bandgap grading structure and chalcopyrite grain growth. The incorporation of potassium in the CIGS film promotes Se uptake in the bulk of the film during the chalcogenization process, resulting in a bandgap grading structure with a wide space charge region that allows improved light absorption in the near-infrared region and charge carrier separation. Also, increasing the Se penetration in the potassium-incorporated CIGS film leads to the enhancement of chalcopyrite crystalline grain growth, increasing charge carrier mobility. Under the reverse bias condition, associated with hole tunneling from the ZnO interlayer, the increasing carrier mobility of potassium-incorporated CIGS photodetector improved photosensitivity and particularly external quantum efficiency more than 100% at low light intensity. The responsivity and detectivity of the potassium-incorporated CIGS photodetector reach 1.87 A W-1 and 6.45 x 10(10) Jones, respectively, and the - 3 dB bandwidth of the device extends to 10.5 kHz under 980 nm near-infrared light

Grape seed proanthocyanidin extract inhibits glutamate-induced cell death through inhibition of calcium signals and nitric oxide formation in cultured rat hippocampal neurons

<p>Abstract</p> <p>Background</p> <p>Proanthocyanidin is a polyphenolic bioflavonoid with known antioxidant activity. Some flavonoids have a modulatory effect on [Ca²⁺]_i. Although proanthocyanidin extract from blueberries reportedly affects Ca²⁺buffering capacity, there are no reports on the effects of proanthocyanidin on glutamate-induced [Ca²⁺]_ior cell death. In the present study, the effects of grape seed proanthocyanidin extract (GSPE) on glutamate-induced excitotoxicity was investigated through calcium signals and nitric oxide (NO) in cultured rat hippocampal neurons.</p> <p>Results</p> <p>Pretreatment with GSPE (0.3-10 μg/ml) for 5 min inhibited the [Ca²⁺]_iincrease normally induced by treatment with glutamate (100 μM) for 1 min, in a concentration-dependent manner. Pretreatment with GSPE (6 μg/ml) for 5 min significantly decreased the [Ca²⁺]_iincrease normally induced by two ionotropic glutamate receptor agonists, N-methyl-D-aspartate and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA). GSPE further decreased AMPA-induced response in the presence of 1 μM nimodipine. However, GSPE did not affect the 50 mM K⁺-induced increase in [Ca²⁺]_i. GSPE significantly decreased the metabotropic glutamate receptor agonist (<it>RS</it>)-3,5-Dihydroxyphenylglycine-induced increase in [Ca²⁺]_i, but it did not affect caffeine-induced response. GSPE (0.3-6 μg/ml) significantly inhibited synaptically induced [Ca²⁺]_ispikes by 0.1 mM [Mg²⁺]_o. In addition, pretreatment with GSPE (6 μg/ml) for 5 min inhibited 0.1 mM [Mg²⁺]_o- and glutamate-induced formation of NO. Treatment with GSPE (6 μg/ml) significantly inhibited 0.1 mM [Mg²⁺]_o- and oxygen glucose deprivation-induced neuronal cell death.</p> <p>Conclusions</p> <p>All these data suggest that GSPE inhibits 0.1 mM [Mg²⁺]_o- and oxygen glucose deprivation-induced neurotoxicity through inhibition of calcium signals and NO formation in cultured rat hippocampal neurons.</p

Analysis of stress distribution in piezoelectric MEMS energy harvester using shaped cantilever structure

Much interest in energy harvesters has been focused on maintaining their conversion efficiency during scaling down via the micromachining process. The piezoelectric PZTbased MEMS energy harvester was designed and fabricated to increase the fraction of the material strained during deflection since the geometric change of the cantilever shape can change the strain distribution on the beam and improve the output power. The generated power during beam deflection was separately collected from individual electrodes located at different positions of the cantilever, and they had good agreement with the strain estimation from finite element analysis. The trapezoidal shape showed 39% higher power than that of rectangular one.OAIID:RECH_ACHV_DSTSH_NO:T200700101RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A080442CITE_RATE:.512DEPT_NM:조경·지역시스템공학부SCOPUS_YN:YCONFIRM: