20 research outputs found

    Stimuli-responsive poly- N -isopropylacrylamide: Phenylene vinylene oligomer conjugate

    No full text
    Phenylene vinylene trimer (OPV) and PNIPAM conjugate with stimuli-responsive optical properties has been synthesized through the formation of amide linkage between PNIPAM and carboxylic-acid-terminated OPV. This material exhibits thermoresponsive optical properties as temperature exceeds the lower critical solution temperature (LCST), which is 32 °C for PNIPAM and the conjugate. This PNIPAM-trimer conjugate is fully characterized by using NMR, FT-IR, temperature-dependent UV-vis, and fluorescence spectroscopy. We have found that the polymer conjugate solution turns opaque as temperature exceeds lower critical solution temperature and a five-fold increase in fluorescence intensity as temperature increases from 20 to 70 °C. Such distinct increase in fluorescence intensity is likely due to the rigidchromism, that is, the change in optical properties due to confinement of the chromophores resulting from restriction of polymer conformational structures. The PNIPAM-trimer conjugate also shows a decrease in decay lifetime with increasing temperature, whereas OPV trimer alone shows no change in decay lifetime as a function of temperature. These unique optical properties are not observed in the trimer and PNIPAM mixture, suggesting that the stimuli-responsive optical properties can occur only in PNIPAM-trimer conjugate linked through covalent bond.Reprinted (adapted) with permission from Journal of Physical Chemistry C, 117 (2013):, pp.7757-7763., doi: 10.1021/jp312157q. Copyright 2013 American Chemical Society.</p

    Real-World Long-Term Clinical Outcomes of Ultrathin Strut Biodegradable Polymer Drug-Eluting Stents in Korean ST-Segment-Elevation Myocardial Infarction (STEMI) Patients with or without Acute Heart Failure Undergoing Primary Percutaneous Coronary Intervention

    No full text
    Biodegradable polymers (BDPs) and ultrathin struts were recently introduced to drug-eluting stents (DES) to further improve outcomes. In this study, we analyzed and compared the effect of the ultrathin strut BDP-DES (UBDP-DES) with the conventional durable polymer-DES (DP-DES) in patients with ST-segment elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PPCI). A total of 356 STEMI patients (n = 160 in the UBDP-DES group and n = 196 in the DP-DES group) were enrolled. The primary endpoint was target lesion failure (TLF), including cardiac death, target vessel myocardial infarction, and ischemic-driven, target lesion revascularization (ID-TLR). The mean age was 60.3 ± 12.7 years (male 81.7%), and the median follow-up duration was 63.8 months. TLF was numerically more frequent in the UBDP-DES group (8.1% vs. 4.1%; HR 2.14; 95% CI 0.89–5.18; p = 0.091). Propensity score matching (PSM) was performed to balance discrepancies in the baseline characteristics due to patients in the UBDP-DES group initially having more unstable vital signs. However, after PSM (n = 116 in each group), there was no significant difference in TLF (5.3% vs. 5.3%; HR 1.04, 95% CI 0.34-3.22; p = 0.947) or other secondary endpoints including ID-TLR. In the subgroup analysis, subjects with initial acute heart failure (AHF), defined as Killip class ≥ 3, were associated with 13.6% chance of 30-day mortality (9-fold of those without AHF), although chances of repeat revascularization were low (3.0%). Among patients with AHF, the UBDP-DES group was associated with a numerically higher chance of TLF compared with the DP-DES group. There was no difference in TLF between groups in patients without AHF. This study showed that UBDP-DES has long-term clinical outcomes similar to those of conventional DP-DES in real-world Korean STEMI patients receiving PPCI, especially in those without initial AHF

    Improved early risk stratification of patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention using a combination of serum soluble ST2 and NT-proBNP.

    No full text
    Although soluble suppression of tumorigenicity 2 (sST2) in serum is known to be associated with ischemic heart disease and heart failure, data regarding its prognostic impact in ST-segment elevation myocardial infarction (STEMI) is limited. We evaluated the prognostic impacts of serum sST2 and other serum biomarkers in STEMI patients undergoing primary percutaneous coronary intervention (PCI).Consecutive all 323 patients with STEMI that underwent primary PCI were enrolled. Blood tests and samples were obtained in an emergency room. The primary endpoint was 1-year major adverse cardiovascular and cerebrovascular events (MACCEs), defined as a composite of cardiovascular death, non-fatal MI, non-fatal stroke, and ischemia-driven revascularization.Mean age was 59.1±13.1 years (men 84%). MACCE (20 cardiovascular deaths, 7 non-fatal MI, 4 non-fatal stroke, 7 ischemia-driven revascularizations) occurred in 38 patients (12%). After adjusting for confounding factors, Cox regression analysis revealed that high serum sST2 (>75.8 ng/mL mean value, adjusted hazard ratio 2.098, 95% CI 1.008-4.367, p = 0.048) and high serum NT-proBNP level (>400 pg/mL, adjusted hazard ratio 2.606, 95% CI 1.086-6.257, p = 0.032) at the time of presentation independently predicted MACCE within a year of primary PCI. Furthermore, when high serum sST2 level was combined with high serum NT-proBNP level, the hazard ratio of MACCE was highest (adjusted hazard ratio 7.93, 95% CI 2.97-20.38, p<0.001).Elevated serum levels of sST2 or NT-proBNP at the time of presentation were found to predict 1-year MACCE independently and elevated serum levels of sST2 plus NT-proBNP were associated with even poorer prognosis in patients with STEMI undergoing primary PCI

    Scientific Missions and Technologies of the ISSS on board the NEXTSat-1

    No full text
    A package of space science instruments, dubbed the Instruments for the Study of Space Storms (ISSS), is proposed for the Next Generation Small Satellite-1 (NEXTSat-1), which is scheduled for launch in May 2016. This paper describes the instrument designs and science missions of the ISSS. The ISSS configuration in NEXTSat-1 is as follows: the space radiation monitoring instruments consist of medium energy particle detector (MEPD) and high energy particle detector (HEPD); the space plasma instruments consist of a Langmuir probe (LP), a retarding potential analyzer (RPA), and an ion drift meter (IDM). The space radiation monitoring instruments (MEPD and HEPD) measure electrons and protons in parallel and perpendicular directions to the geomagnetic field in the sub-auroral region, and they have a minimum time resolution of 50 msec for locating the region of the particle interactions with whistler mode waves and electromagnetic ion cyclotron (EMIC) waves. The MEPD measures electrons and protons with energies of tens of keV to ~400 keV, and the HEPD measures electrons with energies of ~100 keV to > ~1 MeV and protons with energies of ~10 MeV. The space plasma instruments (LP, RPA, and IDM) observe irregularities in the low altitude ionosphere, and the results will be compared with the scintillations of the GPS signals. In particular, the LP is designed to have a sampling rate of 50 Hz in order to detect these small-scale irregularities

    Stimuli-Responsive Poly‑<i>N</i>‑isopropylacrylamide: Phenylene Vinylene Oligomer Conjugate

    No full text
    Phenylene vinylene trimer (OPV) and PNIPAM conjugate with stimuli-responsive optical properties has been synthesized through the formation of amide linkage between PNIPAM and carboxylic-acid-terminated OPV. This material exhibits thermoresponsive optical properties as temperature exceeds the lower critical solution temperature (LCST), which is 32 °C for PNIPAM and the conjugate. This PNIPAM-trimer conjugate is fully characterized by using NMR, FT-IR, temperature-dependent UV–vis, and fluorescence spectroscopy. We have found that the polymer conjugate solution turns opaque as temperature exceeds lower critical solution temperature and a five-fold increase in fluorescence intensity as temperature increases from 20 to 70 °C. Such distinct increase in fluorescence intensity is likely due to the rigidchromism, that is, the change in optical properties due to confinement of the chromophores resulting from restriction of polymer conformational structures. The PNIPAM-trimer conjugate also shows a decrease in decay lifetime with increasing temperature, whereas OPV trimer alone shows no change in decay lifetime as a function of temperature. These unique optical properties are not observed in the trimer and PNIPAM mixture, suggesting that the stimuli-responsive optical properties can occur only in PNIPAM–trimer conjugate linked through covalent bond

    Is Pathologic Axillary Staging Valid If Lymph Nodes Are Less than 10 with Axillary Lymph Node Dissection after Neoadjuvant Chemotherapy?

    No full text
    Introduction: The aim of this study was to evaluate the prognostic value of the number of lymph nodes removed in breast cancer patients who undergo axillary lymph node dissection (ALND) after neoadjuvant chemotherapy (NAC). Methods: We included patients who were diagnosed with invasive breast cancer and cytology with proven involved axillary node metastasis at diagnosis and treated with NAC followed by curative surgery at Samsung Medical Center between January 2007 and December 2015. The primary outcomes were disease-free survival (DFS) and overall survival (OS). Results: Among 772 patients with NAC and ALND, there were 285 ypN0, 258 ypN1, 135 ypN2, and 94 ypN3 cases. The median follow-up duration was 69.0 months. The group with less than 10 lymph nodes number (p = 0.501) or OS (p = 0.883) between the two groups. In the ypN0 subgroup, the p = 0.024). In the ypN1 subgroup, there were no significant differences in DFS (p = 0.846) or OS (p = 0.774) between the two groups. In the ypN2 subgroup, the p = 0.025) and OS (p = 0.031) than ≥10 nodes group Conclusion: In ypN0 and ypN2 subgroups, breast cancer patients with less than 10 lymph nodes number in ALND after NAC might be considered for additional staging or closer surveillance when compared to patients with 10 or more than lymph node

    Effectiveness and safety of adalimumab in patients with intestinal Behçet’s disease: a real-world prospective observational study in South Korea

    No full text
    Abstract Background Intestinal Behçet’s disease (BD) is characterized by typical gastrointestinal ulcers in patients with BD followed by complications such as bleeding, perforation and fistula. Biologic agents are currently under active investigation to delay the disease course. Various data regarding infliximab are available, but there is relatively lack of data regarding adalimumab. Methods This was a multicenter, real-world prospective observational study to evaluate the effectiveness and safety of adalimumab in intestinal BD. The primary endpoint was disease activity at each follow up, including disease activity index for intestinal Behçet’s disease (DAIBD), serum C-reactive protein (CRP) level, and endoscopic findings. The secondary endpoint was the incidence of adverse drug reactions (ADRs). Results A total of 58 patients were enrolled and 8 of them were excluded. Adverse events were reported in 72.0% of patients with 122 events. ADRs were reported in 24.0% with 28 events. For adverse events, arthralgia was most commonly reported (13.1%: 16/122) and only one experienced critical adverse event (0.82%, 1/122: death due to stroke). On multivariable regression analysis, a longer disease duration was significantly associated with decreased ADRs [Odds ratio 0.976 (0.953–0.999, 95% CI); p = 0.042]. Clinical response rates as assessed by DAIBD were 90.9% at Week 12 and 89.7% at Week 56, respectively. The mean serum CRP level at baseline was significantly decreased after 12 weeks (3.91 ± 4.93 to 1.26 ± 2.03 mg/dL; p = 0.0002). Conclusion Adalimumab was found to be safe and effective in Korean patients with intestinal BD. A longer disease duration was significantly associated with decreased ADRs

    Tailored Electronic Structure and Optical Properties of Conjugated Systems through Aggregates and Dipole–Dipole Interactions

    No full text
    A series of PPVO (<i>p</i>-phenylene vinylene oligomer) derivatives with functional groups of varying electronegativity were synthesized via the Horner–Wadsworth–Emmons reaction. Subtle changes in the end group functionality significantly impact the molecular electronic and optical properties of the PPVOs, resulting in broadly tunable and efficient UV absorption and photoluminescence spectra. Of particular interest is the NO<sub>2</sub>-substituted PPVO which exhibits photoluminescence color ranging from the blue to the red, thus encompassing the entire visible spectrum. Our experimental study and electronic structure calculations suggest that the formation of aggregates and strong dipole–dipole solute–solvent interactions are responsible for the observed strong solvatochromism. Experimental and theoretical results for the NH<sub>2</sub>-, H-, and NO<sub>2</sub>-substituted PPVOs suggest that the stabilization of ground or excited state dipoles leads to the blue or red shift of the optical spectra. The electroluminescence (EL) spectra of H-, COOH-, and NO<sub>2</sub>-PPVO have maxima at 487, 518, and 587 nm, respectively, in the OLED device. This trend in the EL spectra is in excellent agreement with the end group-dependent PL spectra of the PPVO thin-films
    corecore