A near-infrared photoinverter based on ZnO and quantum-dots

Near-infrared (NIR) photoswitching transistors have been fabricated using a hybrid structure of zinc oxide (ZnO) and quantum-dots (QDs). The ZnO active layer was prepared using a solution process, while colloidal QDs were inserted between a silicon dioxide (SiO₂) gate insulator and a ZnO active layer. The small band gap QDs (1.59 eV) were used to absorb low-energy NIR photons, generate photo-excited carriers, and inject them into the conduction band of the ZnO film. The device with the interfacial QDs induced photocurrents upon exposure to 780 nm-wavelength light. The photoresponsivity of the ZnO/QD device was 0.06 mA W⁻¹, while that of the device without QDs was 1.7 × 10⁻⁵ mA W⁻¹, which indicated that the small band gap QDs enabled a photo-induced current when exposed to NIR light. Furthermore, a photoinverter was prepared which was composed of a ZnO/QDs phototransistor and a load resistor. Photoswitching characteristics indicated that the photoinverter was well modulated by a periodic light signal of 780 nm in wavelength. The results demonstrate a useful way to fabricate NIR optoelectronics based on ZnO and QDs.

A near-infrared photoinverter was fabricated based on ZnO and quantum-dots. We found that the small band gap quantum-dots could absorb low-energy near-infrared photons, generate photo-excited carriers, and inject them into the conduction band of ZnO.     

Decreased serum level of antibody against human cytomegalovirus in patients with Behçet’s disease

Behçets disease (BD) is a connective tissue disorder characterized by recurrent orogenital ulcer, uveitis, and skin lesions. Recurrent aphthous ulcer is associated with human cytomegalovirus (HCMV). To investigate the possible role of HCMV in BD, we measured the titers of IgG, IgM, and IgA anti-HCMV antibodies in 73 Korean patients with BD, 50 with scleroderma, 70 with systemic lupus erythematosus, and 50 from healthy controls by indirect immunofluorescent staining. The titer of IgG anti-HCMV antibody was significantly lower in patients with BD than in controls (geometric mean 3115.4 vs 9687.6, P=0.0001 by Wilcoxons rank sum test), as was the titer of IgA anti-HCMV antibody (geometric mean 1.9 vs 15.7, P=0.0001, Wilcoxons rank sum test). In conclusion, we found significantly lower antibody responses to HCMV in patients with BD.     

Treatment of verruca vulgaris with topical cidofovir in an immunocompromised patient: a case report and review of the literature

Lesions caused by verrucus vulgaris are commonly refractory to therapy and may become large, painful, or disfiguring in immunocompromised patients. Cidofovir is a potent nucleoside analog antiviral agent shown to have in vitro and in vivo activity against a broad spectrum of DNA viruses. We report a successful use of topical cidofovir to treat verruca vulgaris lesions in a highly immunocompromised patient, who was not considered a candidate for conventional therapy.     

Limitation of the validity of the homeostasis model assessment as an index of insulin resistance in Korea

Homeostasis model assessment of insulin resistance (HOMA-IR) is a less invasive, inexpensive, and less labor-intensive method to measure insulin resistance (IR) as compared with the glucose clamp test. The aim of this study was to evaluate the validity of HOMA-IR by comparing it with the euglycemic clamp test in determining IR. We assessed the validity of HOMA-IR by comparing it with the total glucose disposal rate measured by the 3-hour euglycemic-hyperinsulinemic clamp in subjects with type 2 diabetes (n = 47), impaired glucose tolerance (n = 21), and normal glucose tolerance (n = 22). There was a strong inverse correlation (r = -0.558; P < .001) between the log-transformed HOMA-IR and the total glucose disposal rate. There was moderate agreement between the 2 methods in the categorization according to the IR (weighted kappa = 0.294). The magnitude of the correlation coefficients was smaller in the subjects with a lower body mass index (BMI <25.0 kg/m2 , r = -0.441 vs BMI > or =25.0 kg/m2 , r = -0.615; P = .032), a lower HOMA-beta cell function (HOMA- beta <60.0, r = -0.527 vs HOMA- beta > or =60.0, r = -0.686; P = .016), and higher fasting glucose levels (fasting glucose < or =5.66 mmol/L, r = -0.556 vs fasting glucose >5.66 mmol/L, r = -0.520; P = .039). The limitation of the validity of the HOMA-IR should be carefully considered in subjects with a lower BMI, a lower beta cell function, and high fasting glucose levels such as lean type 2 diabetes mellitus with insulin secretory defects.     

A new technique: Right ventriculography using a preshaped catheter

Right ventriculography with a preshaped catheter (J- or L-shaped) was evaluated in make the diagnosis of tricuspid regurgitation. Thirty normal subjects who did not have valvular disease showed no evidence of tricuspid regurgitation or premature ventricular contractions during injection except in one case. On the other hand, 24 patients with combined aortic and mitral valve disease showed mild to moderate tricuspid regurgitation in 11 patients and severe tricuspid regurgitation in eight patients. Only two patients developed frequent run of premature ventricular contraction during injection. Seven patients with severe tricuspid regurgitation were found to have severe tricuspid regurgitation during surgery. No evidence of tricuspid regurgitation was found In all six patients with isolated aortic valve disease. We can conclude that right ventriculography by the preshaped catheter improves the diagnostic accuracy of tricuspid regurgitation and a grading system of tricuspid regurgitation by angiography is proposed.     

Association between BMI and risk of severe hypoglycaemia in type 2 diabetes

Aim

This study aimed to assess the association between body mass index (BMI) and the development of severe hypoglycaemia in patients with type 2 diabetes (T2D), using nationwide data for the entire South Korean population.

Leptin receptors are down-regulated in uterine implantation sites compared to interimplantation sites

Leptin is a circulating hormone that plays an important role in the regulation of metabolism, obesity, and reproduction. Leptin binds to its receptors on the cell membrane and is involved in the activation of STAT3. Recently, endometrium was suggested to be a novel target for leptin recently. We, therefore, examined the expression of leptin, leptin receptors, and STAT3 in the mouse uterus (implantation and interimplantation sites) to investigate the role of the leptin system during the early implantation period. Leptin mRNA was not detected in mouse uterine tissues or blastocysts, although adipose tissue, the positive control, showed a strong signal. Both of the receptor splice variants were expressed in the uterus and blastocysts, but the mRNA level was much lower in implantation sites compared to interimplantation sites. The mRNA expression of leptin receptors was determined to be higher in stromal cells than in the luminal epithelium using laser capture microdissection (LCM) analysis. Using immunohistochemistry, leptin was detected as a strong signal in the luminal epithelium and embryo, whereas the receptor was detected in subepithelial stromal cells rather than the luminal epithelium. As leptin itself was not detected by RT-PCR, the immunohistologically detected leptin may originate elsewhere, such as in adipose tissue. The differential expression of leptin receptors in implantation sites compared to interimplantation sites suggests that the leptin/leptin receptor system may be a delicate regulator of the implantation process.     

The role of interferon in virus-induced diabetes

The repeated administration of interferon (IFN) or an IFN inducer reduced the development of diabetes in mice infected with the D variant of encephalomyocarditis (EMC) virus. Mice treated with the IFN inducer had less infectious virus, fewer pathologic changes, and higher concentrations of immunoreactive insulin in the islets of Langerhans in comparison with untreated mice. Antibody to mouse IFN (MuIFN) suppressed circulating IFN in mice infected with the B variant of EMC virus. Mice treated with antibody to MuIFN had four times more infected islet cells and 10 times more infectious virus in the pancreas compared with untreated mice. Of the surviving animals treated with antibody to MuIFN, approximately 40% developed mild diabetes whereas none of the mice developed diabetes when infected with the B variant of EMC virus alone. The IFN system is an important determinant of the outcome in EMC virus-induced diabetes in mice.