365 research outputs found

    Oxygen Partial Pressure during Pulsed Laser Deposition: Deterministic Role on Thermodynamic Stability of Atomic Termination Sequence at SrRuO3/BaTiO3 Interface

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    With recent trends on miniaturizing oxide-based devices, the need for atomic-scale control of surface/interface structures by pulsed laser deposition (PLD) has increased. In particular, realizing uniform atomic termination at the surface/interface is highly desirable. However, a lack of understanding on the surface formation mechanism in PLD has limited a deliberate control of surface/interface atomic stacking sequences. Here, taking the prototypical SrRuO3/BaTiO3/SrRuO3 (SRO/BTO/SRO) heterostructure as a model system, we investigated the formation of different interfacial termination sequences (BaO-RuO2 or TiO2-SrO) with oxygen partial pressure (PO2) during PLD. We found that a uniform SrO-TiO2 termination sequence at the SRO/BTO interface can be achieved by lowering the PO2 to 5 mTorr, regardless of the total background gas pressure (Ptotal), growth mode, or growth rate. Our results indicate that the thermodynamic stability of the BTO surface at the low-energy kinetics stage of PLD can play an important role in surface/interface termination formation. This work paves the way for realizing termination engineering in functional oxide heterostructures.Comment: 27 pages, 6 figures, Supporting Informatio

    Resveratrol induces autophagy by directly inhibiting mTOR through ATP competition

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    Resveratrol (RSV) is a natural polyphenol that has a beneficial effect on health, and resveratrol-induced autophagy has been suggested to be a key process in mediating many beneficial effects of resveratrol, such as reduction of inflammation and induction of cancer cell death. Although various resveratrol targets have been suggested, the molecule that mediates resveratrol-induced autophagy remains unknown. Here, we demonstrate that resveratrol induces autophagy by directly inhibiting the mTOR-ULK1 pathway. We found that inhibition of mTOR activity and presence of ULK1 are required for autophagy induction by resveratrol. In line with this mTOR dependency, we found that resveratrol suppresses the viability of MCF7 cells but not of SW620 cells, which are mTOR inhibitor sensitive and insensitive cancer cells, respectively. We also found that resveratrol-induced cancer cell suppression occurred ULK1 dependently. For the mechanism of action of resveratrol on mTOR inhibition, we demonstrate that resveratrol directly inhibits mTOR. We found that resveratrol inhibits mTOR by docking onto the ATP-binding pocket of mTOR (i.e., it competes with ATP). We propose mTOR as a novel direct target of resveratrol, and inhibition of mTOR is necessary for autophagy inductionopen

    Institutional Board Review for Clinical Investigations on Inflammatory Bowel Diseases: A Single-Center Study

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    Background/AimsThe growing volume and the diversity of clinical research has led to related laws and regulations as well as the Institutional Review Board (IRB) approval process becoming more stringent. To conduct clinical research efficiently and while following regulations, information about the IRB approval process and feedback is important for investigators. This has yet to be studied.MethodsWe included 381 gastrointestinal disease research proposals (79 with inflammatory bowel disease [IBD], and 302 with non-IBD) reviewed by the IRB of Severance Hospital between January 2009 and December 2013. We retrospectively analyzed research characteristics including research risk levels, results of initial reviews, frequencies of continuing review, numbers of IRB comments, frequencies of IRB comments, and durations from submission to approval.ResultsInvestigators' decisions on risk level were higher in the IBD group than in the non-IBD group (P<0.05). Results of initial reviews, frequencies of continuing reviews, the numbers of IRB review comments, and durations from submission to approval were not different between the two groups, but IRB decisions on risk level were higher in the IBD group (P<0.05). In subgroup analysis, the number of IRB comments from initial review on informed consent forms and procedures as well were quest of more information were significantly higher in the IBD group than in the non-IBD group (P<0.001 and 0.01, respectively).ConclusionsIn Korea, rare diseases such as IBD require more information for the IRB process due to their distinct characteristics. IBD researchers should develop research protocols more carefully and make their research as subject-friendly as possible

    Comparison of Endoscopic Tympanoplasty to Microscopic Tympanoplasty

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    Objectives This study aimed to compare the outcome of endoscopic and microscopic tympanoplasty. Methods This was a retrospective comparative study of 73 patients (35 males and 38 females) who underwent type I tympanoplasty at Samsung Medical Center from April to December 2014. The subjects were classified into two groups; endoscopic tympanoplasty (ET, n=25), microscopic tympanoplasty (MT, n=48). Demographic data, perforation size of tympanic membrane at preoperative state, pure tone audiometric results preoperatively and 3 months postoperatively, operation time, sequential postoperative pain scale (NRS-11), and graft success rate were evaluated. Results The perforation size of the tympanic membrane in ET and MT group was 25.3%±11.7% and 20.1%±11.9%, respectively (P=0.074). Mean operation time of MT (88.9±28.5 minutes) was longer than that of the ET (68.2±22.1 minutes) with a statistical significance (P=0.002). External auditory canal (EAC) width was shorter in the ET group than in the MT group (P=0.011). However, EAC widening was not necessary in the ET group and was performed in 33.3% of patients in the MT group. Graft success rate in the ET and MT group were 100% and 95.8%, respectively; the values were not significantly different (P=0.304). Pre- and postoperative audiometric results including bone and air conduction thresholds and air-bone gap were not significantly different between the groups. In all groups, the postoperative air-bone gap was significantly improved compared to the preoperative air-bone gap. Immediate postoperative pain was similar between the groups. However, pain of 1 day after surgery was significantly less in the ET group. Conclusion With endoscopic system, minimal invasive tympanoplasty can be possible with similar graft success rate and less pain

    Efficacy and Tolerability of Aripiprazole: A 26-Week Switching Study from Oral Antipsychotics

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    Objective To determine if the maintenance effectiveness and tolerability of aripiprazole demonstrated in a 12-week study were maintained in an extension phase (up to 26 weeks). Methods This study was the extension of our switching study from other antipsychotics to aripiprazole in symptomatically stable patients with schizophrenia or schizoaffective disorder. All the patients were randomly assigned to the aripiprazole group or the non-aripiprazole group. The effectiveness analysis consisted of the comparison of the upper bound of the 95% confidence interval (CI) of the mean Clinical Global Impression-Improvement (CGI-I) score to 4 (no change) at the end of the study. Results At the baseline, the aripiprazole group (n=135) and the non-aripiprazole group (n=31) were comparable with respect to their mean ages, gender distribution, baseline Positive and Negative Syndrome Scale scores, and Clinical Global Impression-Severity (CGI-S) scores. The study showed that the mean CGI-I score was 2.92 (95% CI: 2.72-3.12) in the aripiprazole group and 2.81 (95% CI: 2.35-3.26) in the non-aripiprazole group at 26 weeks. In the aripiprazole group, the remission rates at 12 and 26 weeks were 74.8% and 72.6%, respectively, and 80.2% of the patients with remission at 12 weeks maintained their remission state until the end of the study. About one-fourth of the patients in the aripiprazole group reported one or more spontaneous treatment-emergent adverse events, such as insomnia, headache, and nausea. Conclusion This study suggested that most clinically stable outpatients with schizophrenia maintain their remission states after being switched to aripiprazole, without serious symptom aggravation and adverse events over a course of 26 weeks. Psychiatry Investig 2010;7:189-195This study was supported by Korea Otsuka Pharmaceuticals (KOP 010402).Kim CY, 2009, INT CLIN PSYCHOPHARM, V24, P181, DOI 10.1097/YIC.0b013e32832c25d7Kolotkin RL, 2008, EUR PSYCHIAT, V23, P561, DOI 10.1016/j.eurpsy.2008.01.1421Findling RL, 2008, AM J PSYCHIAT, V165, P1432, DOI 10.1176/appi.ajp.2008.07061035Tandon R, 2008, SCHIZOPHR RES, V100, P20, DOI 10.1016/j.schres.2007.11.033Wolf J, 2007, CURR MED RES OPIN, V23, P2313, DOI 10.1185/030079907X225448Moeller KE, 2006, J CLIN PSYCHIAT, V67, P1942Chrzanowski WK, 2006, PSYCHOPHARMACOLOGY, V189, P259, DOI 10.1007/s00213-006-0564-3Tandon R, 2006, SCHIZOPHR RES, V84, P77, DOI 10.1016/j.schres.2005.12.857Lieberman JA, 2005, NEW ENGL J MED, V353, P1209Kim CY, 2005, J CLIN PSYCHIAT, V66, P887Kasper S, 2003, INT J NEUROPSYCHOPH, V6, P325, DOI 10.1017/S1461145703003651Pigott TA, 2003, J CLIN PSYCHIAT, V64, P1048Potkin SG, 2003, ARCH GEN PSYCHIAT, V60, P681Marder SR, 2003, SCHIZOPHR RES, V61, P123, DOI 10.1016/S0920-9964(03)00050-1Kane JM, 2002, J CLIN PSYCHIAT, V63, P763WEIDEN PJ, 1995, SCHIZOPHRENIA BULL, V21, P419

    Patterns of Recurrence after Breast-Conserving Treatment for Early Stage Breast Cancer by Molecular Subtype

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    Purpose: To study clinical features and patterns of recurrence after breast-conserving treatment (BCT) for three molecular subtypes of early stage breast cancer. Methods: The sample studied included 596 patients with T1-2N0-1 breast cancer who received BCT. Three groups were defined by receptor status. Luminal: estrogen receptor (ER) or progesterone receptor (PR) positive; triple negative (TN): ER, PR, and epidermal growth factor receptor-2 (HER2) receptor negative; and HER2 overexpressing: ER and PR negative but HER2 receptor positive. Results: The number of patients in each group was 408 (68.5%), 105 (17.6%), and 83 (13.9%), respectively. The median follow-up period was 79 months. The TN and HER2 subtypes occurred in younger patients (p=0.0007) and had higher nuclear grade and poorer histologic grade (p&lt;0.0001 and 0.0071, respectively). During the follow-up period, locoregional recurrence was detected as th

    Failure of a Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Efficacy of H. pylori Eradication in H. pylori-Infected Patients with Functional Dyspepsia

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    BACKGROUND/AIMS: The role of Helicobacter pylori eradication in patients with functional dyspepsia (FD) is still uncertain. We originally planned a randomized clinical study to observe dyspeptic symptoms after H. pylori eradication therapy. However, we failed to complete the study; therefore, we analyzed the factors that affected the failure of the study. METHODS: Interviews and questionnaire surveys were conducted to analyze the factors that induced early termination from the study. RESULTS: Many patients were screened by gastroenterologists at 11 tertiary referral hospitals between July 2009 and August 2010; however, only 4 patients met the enrollment criteria. Most patients who visited our clinics had been experiencing FD symptoms for less than 6 months or were already taking medication. They also demanded to continue taking medications and using other drugs. Only 3 of the 4 patients signed informed consent. CONCLUSIONS: The application of the current Rome III criteria to FD is difficult to evaluate in Korean patients with dyspeptic symptoms because of the early medical evaluation. Most Korean patients who were diagnosed with FD by the Rome III criteria did not overcome their fear of being unable to use rescue medications during the study period.ope
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