[Show abstract][Hide abstract] ABSTRACT: Flexible oxide thin-film transistors (Oxide-TFTs) have emerged as next generation transistors because of their applicability in electronic device. In particular, the major driving force behind solution-processed zinc oxide film research is its prospective use in printing for electronics. A low-temperature process to improve the performance of solution-processed n-channel ZnO thin-film transistors (TFTs) fabricated via spin-coating and inkjet-printing is introduced here. ZnO nanoparticles were synthesized using a facile sonochemical method that was slightly modified based on a previously reported method. The influence of the annealing atmosphere on both nanoparticle-based TFT devices fabricated via spin-coating and those created via inkjet printing was investigated. For the inkjet-printed TFTs, the characteristics were improved significantly at an annealing temperature of 150 °C. The field effect mobility, V th, and the on/off current ratios were 3.03 cm2/Vs, −3.3 V, and 104, respectively. These results indicate that annealing at 150 °C 1 h is sufficient to obtain a mobility (μ sat) as high as 3.03 cm2/Vs. Also, the active layer of the solution-based ZnO nanoparticles allowed the production of high-performance TFTs for low-cost, large-area electronics and flexible devices.
Journal of Nanoscience and Nanotechnology 11/2014; 14(11). · 1.15 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We demonstrate an organic one-time programmable memory cell formed entirely at plastic-compatible temperatures. All the processes are performed at below 130 °C. Our memory cell consists of a printed organic transistor and an organic capacitor. Inkjet-printed organic transistors are fabricated by using high-k polymer dielectric blends comprising poly(vinylidenefluoride-trifluoroethylene) [P(VDF-TrFE)] and poly(methyl methacrylate) (PMMA) for low-voltage operation. P(NDI2OD-T2) transistors have a high field-effect mobility of 0.2 cm2/Vs and a low operation gate voltage of less than 10 V. The operation voltage effectively decreases owing to the high permittivity of the P(VDF-TrFE):PMMA blended film. The data in the memory cell are programmed by electrically breaking the organic capacitor. The organic capacitor acts like an antifuse capacitor, because it is initially open, and it becomes permanently short-circuited by applying a high voltage. The organic memory cells are programmed with 4 V, and they are read out with 2 V. The memory data are read out by sensing the current in the memory cell. The printed organic one-time programmable memory is suitable for applications storing small amount of data, such as low-cost radio-frequency identification (RFID) tag.
Journal of Nanoscience and Nanotechnology 11/2014; 14(11). · 1.15 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: ProblemTo investigate whether peripheral blood natural killer (pbNK) cell levels are associated with uterine blood flow, and low molecular weight heparin (LMWH) treatment is effective to improve uterine blood flow in women with decreased uterine blood flow and unexplained recurrent pregnancy loss (RPL).Method of studyThis was a prospective controlled study. Study population included 33 pregnant women (between 5 and 7 weeks gestation) with ≥2 RPL and controls were 47 healthy pregnant women. pbNK cell fractions (CD3−/56+/16+) of peripheral blood mononuclear cells were measured by flow cytometry. Uterine color-pulsed Doppler ultrasound was performed to evaluate uterine radial artery resistance index (URa-RI). In RPL women with elevated URa-RI (≥0.5), LMWH (ranges 40–60 mg/day) was administered subcutaneously daily and URa-RI was reassessed 1 week later. Pregnancy outcome was analyzed at 12 weeks gestation.ResultsURa-RI was significantly higher in pregnant women with RPL than controls (0.60 ± 0.14 versus 0.54 ± 0.12, P = 0.039). In pregnant women with RPL, pbNK cell fractions displayed a positive correlation with URa-RI (Pearson's r = 0.429, P = 0.013). URa-RI was significantly decreased 1 week after LMWH treatment as compared to that of pretreatment (pretreatment RI: 0.65 ± 0.11 versus post-treatment RI: 0.56 ± 0.13, P = 0.011). Pregnancy outcome of RPL women with LMWH treatment was not different from that of pregnant controls (73.3% versus 85.0%, P = NS).Conclusion
Increased pbNK cells are associated with decreased uterine radial artery blood flow. LMWH treatment effectively decreases URa-RI with improved pregnancy outcome in women with RPLs and elevated URa-RI. A larger scale study is needed to verify these findings.
American Journal Of Reproductive Immunology 10/2014; · 3.32 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The flexible organic ferroelectric nonvolatile memory thin film transistors (OFMTs) were fabricated on polydimethylsiloxane (PDMS) elastomer substrates, in which an organic ferroelectric poly(vinylidene-trifluoroethylene) and an organic semiconducting poly(9,9-dioctylfluorene-co-bithiophene) layers were used as gate insulator and active channel, respectively. The carrier mobility, on/off ratio, and subthreshold swing of the OFMTs fabricated on PDMS showed 5 × 10−2 cm2 V−1 s−1, 7.5 × 103, and 2.5 V/decade, respectively. These obtained values did not markedly change when the substrate was bent with a radius of curvature of 0.6 cm. The memory on/off ratio was initially obtained to be 1.5 × 103 and maintained to be 20 even after a lapse of 2000 s. The fabricated OFMTs exhibited sufficiently encouraging device characteristics even on the PDMS elastomer to realize mechanically stretchable nonvolatile memory devices.
[Show abstract][Hide abstract] ABSTRACT: Malignant rhabdoid tumor was first discovered in the kidney, and rhabdoid tumor of the lung was first reported in 1995. These were included as the variants of large-cell carcinoma, according to the 1999 World Health Organization classification of lung tumors. The rhabdoid tumor of the lung exhibits aggressive biological behavior and has a poor prognosis, and only a few reports of this tumor exist. We report a case of lung carcinoma with a rhabdoid phenotype, initially misdiagnosed as an aspergilloma, in a 48-year-old man who presented with recurrent hemoptysis. The chest computed tomography scans showed a huge consolidative lesion with an air crescent sign in the left upper lung and no contrast-enhancing lesion. An aspergilloma was diagnosed by the radiologist. However, after surgical excision and pathological examination, rhabdoid carcinoma was diagnosed. A surgical resection helps to make it possible to pathologically distinguish a malignancy from an aspergilloma.
Tuberculosis and Respiratory Diseases 07/2014; 77(1):38-41.
[Show abstract][Hide abstract] ABSTRACT: Intrauterine insemination (IUI) is a widely used fertility treatment for couples with male and/or non-male factor infertility and is a relatively simple and inexpensive procedure. When used for unexplained infertility, IUI combined with ovarian stimulation increases the pregnancy rates, but evidence does not support this to be true when applied for male factor infertility. Recently, the revised World Health Organization laboratory manual for semen criteria provided a new insight for practical guidelines. Further randomized, controlled studies are necessary to develop standardized IUI strategies. The authors reviewed, via literature search, on the indications, prognostic factors, ovarian stimulation protocols, and methods that have been employed for IUI treatment.
Seminars in Reproductive Medicine 07/2014; 32(4):306-312. · 3.21 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Abstract Context: Local delivery systems for treatment of intractable inner ear disorders have been attempted by many investigators. Objective: To evaluate the permeability and safety of a drug delivery system for the inner ear using a poly(2-hydroxyethyl aspartamide) (PHEA) polymersome. Materials and methods: One-month-old male C57/BL6 mice were used. We administered the same amount of the fluorescent dye, Nile red, into the middle ear in two forms: loaded in PHEA polymersomes (NP group) or diluted in ethanol (NR group). At 1 day after administration, we harvested the cochlea and counted visible red particles in the tissues of cochlea under confocal microscopy and compared the groups. In a safety evaluation, 1 week after the same surgery, we conducted hearing tests and histological evaluations of the bulla and cochlea, and compared the results with those of the sham operation and negative control groups. Results: In terms of permeability, the number of red particles in the organ of Corti was increased significantly in the NP group, and three subjects in the NP group showed uptake of red particles in inner hair cells. However, there was no statistically significant difference in the observations in the lateral wall or modiolus. In safety tests, the NP and sham-operation groups showed decreased DPOAE responses and mildly swollen middle ear mucosa, compared with the negative control group, which was thought to be the result of postoperative changes. Conclusions: PHEA nanoparticles may have utility as a drug carrier into the inner ear in terms of both permeability and safety.
[Show abstract][Hide abstract] ABSTRACT: Objective
To investigate the complete metabolic and phenotypic profiles of a large cohort of untreated, consecutively recruited Korean women with polycystic ovary syndrome (PCOS), for whom a registry for Korean women with PCOS was constructed.
Three infertility clinics and 10 university hospitals.
Eight hundred sixty-five women with PCOS were recruited using the Rotterdam criteria.
Standardized evaluation protocol and web-based case report form.
Main Outcome Measure(s)
Metabolic and phenotypic profiles.
The subjects with PCOS mainly consisted of young and nonobese women. The most problematic subjective symptom was menstrual disturbance or infertility, and, on average, the patients seemed to menstruate every 2 months. PCO morphology was observed in 96.5% of the patients. Although few women visited hospitals owing to HA symptoms alone, hirsutism was observed in one-third of the patients (33.9%) and half (47.4%) of the patients had biochemical HA. About one-fifth (20.1%) of the patients had generalized obesity, and one-third (33.2%) had central obesity. Prevalence of dyslipidemia, diabetes, hypertension, and metabolic syndrome were 35.7%, 3.5%, 4.0%, and 13.7%, respectively. Prevalence of prediabetes was 20.8%, and a substantial proportion of additional subjects with normal fasting plasma glucose or oral glucose tolerance tests were identified as having prediabetes by hemoglobin A1C testing.
Our well-defined cohort provided comprehensive estimates of the features of metabolic and phenotypic profiles related to PCOS in Korean women. Further longitudinal follow-up studies are needed to investigate the changes in phenotypic and metabolic markers in this PCOS cohort.
Fertility and sterility 01/2014; · 3.97 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We propose a new technique for fabricating well-controlled wavy surface structures on an elastomeric substrate at a few-micrometer scale without any pre-stretching and deposition steps, as the platform for stretchable metal interconnects. In this process, the wavy structure is defined by photolithography on a stress-free elastomeric substrate, so that we can provide various types of wavy profiles for metal interconnects with arbitrary sizes and orientations within a single substrate. As the wavy structures can be formed only within selected regions while keeping the whole substrate area free of strain, it may be possible to fabricate entire circuitry including active devices directly on the elastomeric substrate with no need for mechanical transfer steps. The present technique can provide a practical strategy for realizing large-area stretchable electronic circuits, for various applications such as stretchable display or wearable electronic systems.
[Show abstract][Hide abstract] ABSTRACT: Copper (Cu)-carbon nanotube (CNT) composite surface coatings with CNT contents of up to 15 vol.% were fabricated by mechanical alloying (MA) and cold gas dynamic spray (CGDS) process. The MA powder and CGDS coating samples were characterized by weight and size measurements, optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction. The coatings were also examined by profilometry and porosimetry. The results showed that the particle sizes of MA composite powders and their deposition efficiencies (DEs) in CGDS decreased with the increase of CNT content. The DE also decreased with the increase of coating layers. The XRD results indicated that the composite powders and coatings had microstrains and undergone grain size reduction due to the deformation caused by MA and CGDS. The coating surface and internal microstructures had flattened lamellar features, which indicated severe deformation that resulted from impact during the deposition of particles as well as from the impact of the rebounded particles. Some internal pores were present along the interfaces of the deposited particles. The surface roughness values of the coatings were observed to be related to the sizes of the powder particles. The roughness tended to decrease with the reduction of particle sizes. Also, the coatings contained about 1.0–2.5 vol.% surface micropores. However, the comparison between the trend of the surface roughness and the quantity of surface pores did not show direct correlation. Composition analysis of the coatings revealed the uniform dispersion of CNTs within the coatings.
[Show abstract][Hide abstract] ABSTRACT: A controlled magnetic field creates patterns of superparamagnetic nanoparticles with a minimum line width of 10 μm on a flexible substrate. This magnetic printing method is also successfully used to print conductive patterns consisting of copper or carbon nanomaterials.
[Show abstract][Hide abstract] ABSTRACT: We propose a new scheme of stretchable metal interconnects utilizing the
electroplated three-dimensional (3D) coil structure, as a strategy for
improving the stretching performance of spring-like electrodes through
the suppression of local stress concentration. In this process, the 3D
copper coils are fabricated by a multi-step electroplating process, and
embedded within an elastomeric substrate forming stretchable
configuration. By comparing the stretching behavior of the
two-dimensional and 3D coils under static or cyclic deformation, the
beneficial effects of the 3D configuration have been demonstrated. The
present technique can be regarded as an effective way to enhance the
stability of interconnects under cyclic deformation significantly, while
maintaining the high mechanical strength and electrical conductivity of
Journal of Micromechanics and Microengineering 12/2013; 23(12):7002-. · 1.79 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Chemokines and their receptors are important players in organism homeostasis, development and immune response to inflammatory stimuli. In the present study, we examined effects of ischemia-reperfusion injury on the immunoreactivity and protein levels of chemokine C-C motif receptor 7 (CCR7) in the gerbil hippocampus (CA1-3 regions) after 5min of transient global cerebral ischemia. CCR7 immunoreactivity was dramatically changed in the pyramidal neurons of the CA1, not CA2/3, region after ischemia-reperfusion. The immunoreactivity was increased after ischemia-reperfusion, and it was barely found from 5days post-ischemia. In addition, CCR7 immunoreactivity was newly expressed in astrocytes, not microglia, in the ischemic CA1 region from 5days post-ischemia. However, we did not observe this finding in the ischemic CA2/3 region. Furthermore, CCR7 protein levels in the ischemic CA1 region were changed like the change pattern of its immunoreactivity. These results indicate that both CCR7 immunoreactivity and protein levels are distinctively altered only in the CA1 region after transient cerebral ischemia and that the changes in CCR7 expression may be related to the ischemia-induced delayed neuronal death.
Journal of the neurological sciences 11/2013; · 2.32 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We evaluated the effect of intrawound application of vancomycin powder for infection prophylaxis in wounds caused by instrumented spinal surgery.
From July 2012 to December 2012, 74 instrumented spinal fusion procedures were performed by 1 neurosurgeon at a single institute. We divided the patients into 2 groups, depending on the use of local application of vancomycin powder: Group A (intrawound application of vancomycin powder with perioperative intravenous cefazolin) and Group B (perioperative intravenous cefazolin alone). A retrospective cohort comparative study was conducted between the 2 groups. The age, sex, comorbidities, smoking, surgical procedure, and surgical site infection (SSI) of consecutive patients were analyzed.
Among the 74 patients, 34 patients were assigned to group A and 40 patients to group B. No wound infections were found in group A. However, in group B, 5 cases of SSI (12.5%) were found. A statistically significant reduction in SSI incidence was observed in group A (p<0.033). The 5 cases of SSI in group B consisted of 3 cases of deep wound infection and 2 cases of superficial wound infection. All SSIs were found in cases of posterior approach surgery and tended to be more frequent in older patients.
Adjunctive intrawound local application of vancomycin powder is a simple uncomplicated procedure and can result in a significant reduction of SSI in instrumented spinal fusions. Furthermore, culture of the drainage tip is very important for confirmation of deep wound infection.
[Show abstract][Hide abstract] ABSTRACT: To evaluate correlations between serum anti-Müllerian hormone (AMH) levels, phenotypes of polycystic ovary syndrome (PCOS), obesity, and metabolic parameters in patients with PCOS.
A total of 175 patients with PCOS were diagnosed according to the Rotterdam Consensus were included. Exclusion criteria were age over 40, FSH>25 mIU/mL, and 17a-OHP>1.5 ng/mL. The Phenotypes of PCOS were divided into a severe form (oligo-anovulation, ANOV/hyperandrogenism/polycystic ovary morphology [PCOM]; n=59) and a mild form without HA (ANOV/PCOM, n=105). The serum AMH levels were classified into 3 groups (<5 vs. 5-10 vs. >10 ng/mL). Obesity was defined as body mass index (BMI) ≥25 kg/m(2) (n=34).
The mean age was 25.9±5.7 year and mean AMH level was 10.1±5.4 ng/mL. The BMI (kg/m(2)) was higher in group 1 (24.2±6.3) than in group 2 (21.9±4.3, p=0.046) or group 3 (21.6±3.3, p=0.019). There was no difference among the three groups in age, menstrual interval, antral follicle counts, androgens, or other metabolic parameters. The obesity group showed significantly lower AMH (7.7±3.9 ng/mL vs. 10.7±5.6 ng/mL), p=0.004) and low-density lipoprotein levels (93.1±21.2 mg/dL vs. 107.5±39.3 mg/dL, p=0.031), and showed higher total T (0.74±0.59 ng/mL vs. 0.47±0.36 ng/mL, p=0.001), free T (2.01±1.9 vs. 1.04±0.8 pg/mL, p=0.0001), and free androgen index (6.2±7.9 vs. 3.5±3.0, p=0.003). After controlling for age factors and BMI, the serum AMH levles did not show any significant correlations with other hormonal or metabolic parmeters.
For PCOS patients under the age 40, serum AMH is not negatively correlated with age. High serum AMH levels can not predict the phenotype of PCOS and metabolic disturbances in PCOS patients in the non-obese group. Further study might be needed to define the relation more clearly.
Clinical and experimental reproductive medicine. 09/2013; 40(3):135-40.
[Show abstract][Hide abstract] ABSTRACT: The objectives of the present study were to characterize the natural course of initially non-operated traumatic acute subdural hematoma (ASDH) and to identify the risk factors of hematoma progression.
Retrospective analysis was performed using sequential computed tomography (CT) images maintained in a prospective observational database containing 177 ASDH cases treated from 2005 to 2011. Patients were allocated to four groups as followings; 136 (76.8%) patients to the spontaneous resolution group, 12 (6.8%) who underwent operation between 4 hours and 7 days to the rapid worsening group (RWG), 24 (13.6%) who experienced an increase of hematoma and that underwent operation between 7 and 28 days to the subacute worsening group (SWG), and 5 (2.8%) who developed delayed aggravation requiring surgery from one month after onset to the delayed worsening group (DWG). Groups were compared with respect to various factors.
No significant intergroup difference was found with respect to age, mechanism of injury, or initial Glasgow Coma Scale. The presence of combined cerebral contusion or subarachnoid hemorrhage was found to be a significant prognostic factor. Regarding CT findings, mixed density was common in the RWG and the SWG. Midline shifting, hematoma thickness, and numbers of CT slices containing hematoma were significant prognostic factors of the RWG and the SWG. Brain atrophy was more severe in the SWG and the DWG.
A large proportion of initially non-operated ASDHs worsen in the acute or subacute phase. Patients with risk factors should be monitored carefully for progression by repeat CT imaging.
Journal of Korean Neurosurgical Society 09/2013; 54(3):211-219. · 0.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We present a case of acute hydrocephalus secondary to cervical spinal cord injury in a patient with diffuse ossification of the posterior longitudinal ligament (OPLL). A 75-year-old male patient visited the emergency department with tetraparesis and spinal shock. Imaging studies showed cervical spinal cord injury with hemorrhage and diffuse OPLL from C1 to C4. We performed decompressive laminectomy and occipitocervical fusion. Two days after surgery, his mental status had deteriorated to drowsiness with dilatation of the right pupil. Findings on brain computed tomography revealed acute hydrocephalus and subarachnoid hemorrhage in the cerebellomedullary cistern, therefore, extraventricular drainage was performed immediately. Acute hydrocephalus as a complication of cervical spine trauma is rare, however, it should be considered if the patient shows deterioration of neurologic symptoms.
Journal of Korean Neurosurgical Society 08/2013; 54(2):145-7. · 0.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The extent of neuronal damage/death in some brain regions is highly correlated to duration time of transient ischemia. In the present study, we carried out neuronal degeneration/death and glial changes in the septum 4 days after 5, 10, 15, and 20 min of transient cerebral ischemia using gerbils. To examine neuronal damage, Fluoro-Jade B (F-J B, a marker for neuronal degeneration) histofluorescence staining was used. F-J B positive ((+)) cells were detected in the septo-hippocampal nucleus (SHN) of the septum only in the 20 min ischemia-group; the mean number of F-J B(+) neurons was 14.9 ± 2.5/400 μm(2) in a section. Gliosis of astrocytes and microglia was examined using anti-glial fibrillary acidic protein (GFAP) and anti-ionized calcium-binding adapter molecule 1 (Iba-1), respectively. In all the ischemia-groups, GFAP- and Iba-1-immunoreactive astrocytes and microglia, respectively, were increased in number, and apparently tended to be increased in their immunoreactivity. Especially, in the 20 min ischemia-group, the number and immunoreactivity of Iba-immunoreactive microglia was highest and strongest in the ischemic SHN 4 days after ischemia-reperfusion. In brief, our findings showed that neuronal damage/death in the SHN occurred and gliosis was apparently increased in the 20 min ischemia-group at 4 days after ischemia-reperfusion.
Cellular and Molecular Neurobiology 07/2013; · 2.29 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To evaluate the efficacy of earlier oocyte retrieval in IVF patients with a premature LH surge on hCG day.
One hundred forty IVF patients (164 cycles) with premature LH surge on hCG day were included, retrospectively. We divided them into 2 study groups: LH surge with timed ovum pick-up (OPU) 36 hours after hCG injection (group B, 129 premature cycles), and LH surge with earlier OPU within 36 hours after hCG injection (group C, 35 cycles). Control groups were tubal factor infertility without premature LH surge (group A, 143 cycles).
The mean age (year) was statistically higher in group C than in groups A or B (38.2±5.4 vs. 36.2±4.2 vs. 36.8±4.9, respectively; p=0.012). The serum LH levels (mIU/mL) on hCG day were significantly higher in group B and C than in group A (22.7±14.9 vs. 30.3±15.9 vs. 3.2±2.9, respectively; p>0.001). Among groups A, B, and C, 4.9%, 31.7%, and 51.4% of the cycles, respectively, had no oocytes, and the overall rates of cycle cancellation (OPU cancellation, no oocyte, or no embryos transferrable) were 15.4%, 65.9%, and 74.3%, respectively. The fertilization rate (%) was significantly higher in group B than in group C (73.2±38.9 vs. 47.8±42.9, p=0.024). The clinical pregnancy rate was significantly higher in group C than in groups A and B (44.4% vs. 27.3% vs. 9.1%, respectively, p=0.021). However, the miscarriage rate was also higher in group C than in group B (22% vs. 0%, respectively, p=0.026).
Earlier OPU may not be effective in reducing the risk of cycle cancellation in patients with premature LH surge on hCG day. A larger scale study will be required to reveal the effectiveness of earlier ovum retrieval with premature LH surge.
Clinical and experimental reproductive medicine. 06/2013; 40(2):90-4.
[Show abstract][Hide abstract] ABSTRACT: Superparamagnetic iron oxide nanoparticles are widely used as nanoprobes for magnetic resonance imaging (MRI). In this study, a novel type of cross-linked magnetic nanoparticle was developed in an effort to improve the structural stability of amphiphilic polymer-coated iron oxide nanoparticles. Iron oxide nanocrystals were coated with a cross-linkable amphiphilic graft copolymer, poly(succinimide) grafted with folate-conjugated polyethylene glycol (PEG) and alkyl chains. The tumor-specific targeting ligand, folate, was included to target and detect cancer cells. The hydrophobic portions of the amphiphilic copolymer on the surfaces of the nanoparticles were cross-linked via an aminolysis reaction between the succinimide units and a bifunctional primary amine. The folate-conjugated cross-linked magnetic nanoparticles (F-CLMNPs) were 40 nm in diameter and displayed a low cytotoxicity, even at relatively high concentrations. The F-CLMNPs exhibited highly efficient intracellular uptake into KB cells, which overexpress the folate receptor, as determined by fluorescence microscopy, flow cytometry, and Prussian blue staining. In vivo MR images of a mouse bearing a KB cell tumor displayed a 75% drop in the T2 signal in the tumor tissues within 3 hours. These results indicated that the F-CLMNPs accumulated at the tumor site and were highly effective for tumor detection using in vivo MRI techniques.