Effect of Crystallization Modes in TIPS-Pentacene/Insulating Polymer Blends on the Gas Sensing Properties of Organic Field-Effect Transistors

Blending organic semiconductors with insulating polymers has been known to be an effective way to overcome the disadvantages of single-component organic semiconductors for high-performance organic field-effect transistors (OFETs). We show that when a solution processable organic semiconductor (6,13-bis(triisopropylsilylethynyl)pentacene, TIPS-pentacene) is blended with an insulating polymer (PS), morphological and structural characteristics of the blend films could be significantly influenced by the processing conditions like the spin coating time. Although vertical phase-separated structures (TIPS-pentacene-top/PS-bottom) were formed on the substrate regardless of the spin coating time, the spin time governed the growth mode of the TIPS-pentacene molecules that phase-separated and crystallized on the insulating polymer. Excess residual solvent in samples spun for a short duration induces a convective flow in the drying droplet, thereby leading to one-dimensional (1D) growth mode of TIPS-pentacene crystals. In contrast, after an appropriate spin-coating time, an optimum amount of the residual solvent in the film led to two-dimensional (2D) growth mode of TIPS-pentacene crystals. The 2D spherulites of TIPS-pentacene are extremely advantageous for improving the field-effect mobility of FETs compared to needle-like 1D structures, because of the high surface coverage of crystals with a unique continuous film structure. In addition, the porous structure observed in the 2D crystalline film allows gas molecules to easily penetrate into the channel region, thereby improving the gas sensing properties

Enhanced cytotoxic effect of radiation and temozolomide in malignant glioma cells: targeting PI3K-AKT-mTOR signaling, HSP90 and histone deacetylases

BACKGROUND: Despite aggressive treatment with radiation therapy and concurrent adjuvant temozolomide (TMZ), glioblastoma multiform (GBM) still has a dismal prognosis. We aimed to identify strategies to improve the therapeutic outcome of combined radiotherapy and TMZ in GBM by targeting pro-survival signaling from the epidermal growth factor receptor (EGFR). METHODS: Glioma cell lines U251, T98G were used. Colony formation, DNA damage repair, mode of cell death, invasion, migration and vasculogenic mimicry as well as protein expression were determined. RESULTS: U251 cells showing a low level of methyl guanine transferase (MGMT) were highly responsive to the radiosensitizing effect of TMZ compared to T98G cells having a high level of MGMT. Treatment with a dual inhibitor of Class I PI3K/mTOR, PI103; a HSP90 inhibitor, 17-DMAG; or a HDAC inhibitor, LBH589, further increased the cytotoxic effect of radiation therapy plus TMZ in U251 cells than in T98G cells. However, treatment with a mTOR inhibitor, rapamycin, did not discernibly potentiate the radiosensitizing effect of TMZ in either cell line. The mechanism of enhanced radiosensitizing effects of TMZ was multifactorial, involving impaired DNA damage repair, induction of autophagy or apoptosis, and reversion of EMT (epithelial-mesenchymal transition). CONCLUSIONS: Our results suggest possible strategies for counteracting the pro-survival signaling from EGFR to improve the therapeutic outcome of combined radiotherapy and TMZ for high-grade gliomas

Skin wound healing rate in fish depends on species and microbiota

The skin is a barrier between the body and the environment that protects the integrity of the body and houses a vast microbiota. By interacting with the host immune system, the microbiota improves wound healing in mammals. However, in fish, the evidence of the role of microbiota and the type of species on wound healing is scarce. We aimed to examine the wound healing rate in various fish species and evaluate the effect of antibiotics on the wound healing process. The wound healing rate was much faster in two of the seven fish species selected based on habitat and skin types. We also demonstrated that the composition of the microbiome plays a role in the wound healing rate. After antibiotic treatment, the wound healing rate improved in one species. Through 16S rRNA sequencing, we identified microbiome correlates of varying responses on wound healing after antibiotic treatment. These findings indicate that not only the species difference but also the microbiota play a significant role in wound healing in fish.1

Hepatic glycogenosis in type 1 diabetes mellitus mimicking Mauriac syndrome

Hepatic glycogenosis in type 1 diabetes mellitus (DM) can be caused by poor glycemic control due to insulin deficiency, excessive insulin treatment for diabetic ketoacidosis, or excessive glucose administration to control hypoglycemia. Mauriac syndrome, which is characterized by hepatomegaly due to hepatic glycogenosis, growth retardation, delayed puberty, and Cushingoid features, is a rare diabetic complication. We report a case of hepatic glycogenosis mimicking Mauriac syndrome. A 14-year-old girl with poorly controlled type 1 DM was admitted to The Catholic University of Korea, Seoul St. Mary's Hospital for abdominal pain and distension. Physical examination revealed hepatomegaly and a Cushingoid face. The growth rate of the patient had decreased, and she had not yet experienced menarche. Laboratory findings revealed elevated liver enzyme levels. A liver biopsy confirmed hepatic glycogenosis. Continuous glucose monitoring showed hyperglycemia after meals and frequent hypoglycemia before meals. To control hyperglycemia, we increased insulin dosage by using an insulin pump. In addition, we prescribed uncooked cornstarch to prevent hypoglycemia. After strict blood glucose control, the patient's liver functions and size normalized. The patient subsequently underwent menarche. Hepatic glycogenosis is a complication of type 1 DM that is reversible with appropriate glycemic control

Tuberculosis-associated hemophagocytic lymphohistiocytosis in adolescent diagnosed by polymerase chain reaction

We present a case of tuberculosis-associated hemophagocytic lymphohistiocytosis in a 14-year-old girl. The patient presented with weight loss, malaise, fatigue, prolonged fever, and generalized lymphadenopathy. Laboratory investigation revealed pancytopenia (white blood cells, 2,020 cells/µL; hemoglobin, 10.2 g/dL; platelets, 52,000 cells/µL), hypertriglyceridemia (229 mg/dL), and hyperferritinemia (1,420 ng/mL). Bone marrow biopsy showed a hypocellular bone marrow with a large numbers of histiocytes and marked hemophagocytosis; based on these findings, she was diagnosed with hemophagocytic lymphohistiocytosis. Polymerase chain reaction (PCR) with both the bone marrow aspiration and sputum samples revealed the presence of Mycobacterium tuberculosis. Antitubercular therapy with immune modulation therapy including dexamethasone and intravenous immunoglobulin was initiated. The results of all laboratory tests including bone marrow biopsy and PCR with both the bone marrow aspiration and sputum samples were normalized after treatment. Thus, early bone marrow biopsy and the use of techniques such as PCR can avoid delays in diagnosis and improve the survival rates of patients with tuberculosis-associated hemophagocytic lymphohistiocytosis

Identification of novel urinary biomarkers for assessing disease activity and prognosis of rheumatoid arthritis

To optimize treatment for rheumatoid arthritis (RA), it is ideal to monitor the disease activity on a daily basis because RA activity fluctuates over time. Urine can be collected routinely at home by patients. Recently, we identified four urinary biomarker candidates-gelsolin (GSN), orosomucoid (ORM)1, ORM2 and soluble CD14 (sCD14)-in RA patients through transcriptomic and proteomic studies. Here, we investigated the clinical significance of the aforementioned urinary biomarker candidates in a prospective manner. For the first time, we found that urinary ORM1, ORM2 and sCD14 levels, but not GSN, were elevated in RA patients and had a positive correlation with the status of the disease activity. In particular, urine tests for ORM 1, ORM 2 and sCD14 efficiently represented the presence of high RA activity without the need for measuring blood markers. In a parallel study, a more rapid radiographic progression over 3 years was observed in patients with higher ORM2 levels. Combined measurements of urinary ORM2 and serum C-reactive protein synergistically increased the predictability of the radiographic progression of RA (odds ratio: 46.5). Collectively, our data provide evidence that blood-free, urinary biomarkers are promising surrogates for assessing disease activity and prognosis of RA. We anticipate that our urinary biomarkers will provide novel candidates for patient-driven measurements of RA activity at home and can shift the paradigm from blood to urine testing in the assessment of RA activity and prognosis in hospitals.1