369 research outputs found

    Cryogenic Magneto-Terahertz Scanning Near-field Optical Microscope (cm-SNOM)

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    We have developed a versatile near-field microscopy platform that can operate at high magnetic fields and below liquid-helium temperatures. We use this platform to demonstrate an extreme terahertz (THz) nanoscope operation and to obtain the first cryogenic magneto-THz time-domain nano-spectroscopy/imaging at temperatures as low as 1.8 K and magnetic fields of up to 5 T simultaneously. Our cryogenic magneto-THz scanning near-field optical microscopy, or cm-SNOM, instrument comprises three main equipment: i) a 5 T split pair magnetic cryostat with a custom made insert for mounting SNOM inside; ii) an atomic force microscope (AFM) unit that accepts ultrafast THz excitation and iii) a MHz repetition rate, femtosecond laser amplifier for high-field THz pulse generation and sensitive detection. We apply the cm-SNOM to obtain proof of principle measurements of superconducting and topological materials. The new capabilities demonstrated break grounds for studying quantum materials that requires extreme environment of cryogenic operation and applied magnetic fields simultaneously in nanometer space, femtosecond time, and terahertz energy scales

    Relapsed acute myeloid leukemia presenting as conjunctival myeloid sarcoma: a case report

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    Abstract Background Conjunctival myeloid sarcoma (MS) as an isolated presentation of acute myeloid leukemia (AML) relapse is rare. Here, we report a case of unilateral conjunctival MS revealed as a sign of AML relapse. Case presentation A 50-year-old man with a history of AML in remission visited our clinic presenting with a left conjunctival injection persisting for 1 month. Diffuse subconjunctival thickening with conjunctival vascular engorgement was observed. Ultrasound biomicroscopy revealed a hyper-reflective, thickened conjunctiva in his left eye. During the incisional biopsy, the lesion was strongly attached to the underlying sclera; histopathologic examination revealed infiltration of leukemic blasts. The relapse of AML was confirmed by a successive bone marrow biopsy. The ocular lesion disappeared after allogeneic peripheral blood stem cell transplantation (PBSCT) and concomitant salvage radiotherapy on the left eye. The patient has remained in remission for 3 years after allogeneic PBSCT. Conclusions Incidental conjunctival lesions can indicate AML relapse in patients treated earlier for AML. An ophthalmologist may have a role in the early detection of AML when a patient presents with an atypical conjunctival lesion

    Unresectable gastric cancer with gastric outlet obstruction and distant metastasis responding to intraperitoneal and folfox chemotherapy after palliative laparoscopic gastrojejunostomy: report of a case

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    <p>Abstract</p> <p>Background</p> <p>Gastric outlet obstruction (GOO) caused by unresectable gastric cancer is a challenging aspect of patient care. There have been no reports involving patients with obstructing gastric cancer and several incurable factors curatively treated by multimodal treatments.</p> <p>Case presentation</p> <p>We report a case of 55-year-old man who was diagnosed with a poorly differentiated adenocarcinoma in the pre-pyloric antrum with GOO by gastroscopy. An abdominal computed tomography (CT) scan revealed thickening of the gastric wall and adjacent fat infiltration, and a large amount of food in the stomach suggesting a passage disturbance, enlarged lymph nodes along the common hepatic and left gastric arteries, and multiple hepatic metastases. The serum carcinoembryonic antigen (CEA) level was 343 ng/ml and the carbohydrate antigen (CA) 19-9 level was within normal limits. The patient underwent a laparoscopic gastrojejunostomy for palliation of the GOO. On the 3<sup>rd </sup>and 12<sup>th </sup>days after surgery, he received intraperitoneal chemotherapy with 40 mg of docetaxel and 150 mg of carboplatin. Simultaneously, combined chemotherapy with 85 mg/m<sup>2 </sup>of oxaliplatin for the 1<sup>st </sup>day and 600 mg/m<sup>2 </sup>of 5-FU for 2 days (FOLFOX regimen) was administered from the 8<sup>th </sup>post-operative day. After completion of nine courses of FOLFOX, the patient achieved a complete response (CR) with complete disappearance of the primary tumor and the metastatic foci. He underwent a radical subtotal gastrectomy with D3 lymph node dissection 4 months after the initial palliative surgery. The pathologic results revealed no residual primary tumor and no lymph node metastasis in 43 dissected lymph nodes. He has maintained a CR for 18 months since the last operation.</p> <p>Conclusion</p> <p>Combination chemotherapy with systemic and intraperitoneal chemotherapy following laparoscopic bypass surgery showed marked efficacy in the treatment for unresectable advanced gastric cancer with GOO.</p

    Ultrafast Control of Excitonic Rashba Fine Structure by Phonon Coherence in the Metal Halide Perovskite CH3NH3PbI3

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    We discover hidden Rashba fine structure in CH3NH3PbI3 and demonstrate its quantum control by vibrational coherence through symmetry-selective vibronic (electron-phonon) coupling. Above a critical threshold of a single-cycle terahertz pump field, a Raman phonon mode distinctly modulates the middle excitonic states with persistent coherence for more than ten times longer than the ones on two sides that predominately couple to infrared phonons. These vibronic quantum beats, together with first-principles modeling of phonon periodically modulated Rashba parameters, identify a threefold excitonic fine structure splitting, i.e., optically forbidden, degenerate dark states in between two bright ones with a narrow, similar to 3 nm splitting. Harnessing of vibronic quantum coherence and symmetry inspires light-perovskite quantum control and sub-THz-cycle Rashba engineering of spin-split bands for ultimate multifunction device

    An Antireflective Nanostructure Array Fabricated by Nanosilver Colloidal Lithography on a Silicon Substrate

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    An alternative method is presented for fabricating an antireflective nanostructure array using nanosilver colloidal lithography. Spin coating was used to produce the multilayered silver nanoparticles, which grew by self-assembly and were transformed into randomly distributed nanosilver islands through the thermodynamic action of dewetting and Oswald ripening. The average size and coverage rate of the islands increased with concentration in the range of 50–90 nm and 40–65%, respectively. The nanosilver islands were critically affected by concentration and spin speed. The effects of these two parameters were investigated, after etching and wet removal of nanosilver residues. The reflection nearly disappeared in the ultraviolet wavelength range and was 17% of the reflection of a bare silicon wafer in the visible range

    Efficacy of fixed-dose amlodipine and losartan combination compared with amlodipine monotherapy in stage 2 hypertension: a randomized, double blind, multicenter study

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    <p>Abstract</p> <p>Background</p> <p>The objective of this trial was to compare the blood-pressure lowering efficacy of amlodipine/losartan combination with amlodipine monotherapy after 6 weeks of treatment in Korean patients with stage 2 hypertension.</p> <p>Results</p> <p>In this multi-center, double-blind, randomized study, adult patients (n = 148) with stage 2 hypertension were randomized to amlodipine 5 mg/losartan 50 mg or amlodipine 5 mg. After 2 weeks, patients with systolic blood pressure (SBP) > 140 mmHg were titrated to amlodipine 10 mg/losartan 50 mg or amlodipine 10 mg. After 4 weeks of titration, hydrochlorothiazide 12.5 mg could be optionally added to both groups. The change from baseline in SBP was assessed after 6 weeks. The responder rate (defined as achieving SBP < 140 mmHg or DBP < 90 mmHg) was also assessed at 2, 6 and 8 weeks as secondary endpoints. Safety and tolerability were assessed through adverse event monitoring and laboratory testing. Baseline demographics and clinical characteristics were generally similar between treatment groups. Least-square mean reduction in SBP at 6 weeks (primary endpoint) was significantly greater in the combination group (36.5 mmHg vs. 31.6 mmHg; p = 0.0117). The responder rate in SBP (secondary endpoints) was significantly higher in the combination group at 2 weeks (52.1% vs. 33.3%; p = 0.0213) but not at 6 weeks (p = 0.0550) or 8 weeks (p = 0.0592). There was no significant difference between groups in the incidence of adverse events.</p> <p>Conclusion</p> <p>These results demonstrate that combination amlodipine/losartan therapy provides an effective and generally well-tolerated first line therapy for reducing blood pressure in stage 2 hypertensive patients.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01127217">NCT01127217</a></p

    SNPs and Other Features as They Predispose to Complex Disease: Genome-Wide Predictive Analysis of a Quantitative Phenotype for Hypertension

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    Though recently they have fallen into some disrepute, genome-wide association studies (GWAS) have been formulated and applied to understanding essential hypertension. The principal goal here is to use data gathered in a GWAS to gauge the extent to which SNPs and their interactions with other features can be combined to predict mean arterial blood pressure (MAP) in 3138 pre-menopausal and naturally post-menopausal white women. More precisely, we quantify the extent to which data as described permit prediction of MAP beyond what is possible from traditional risk factors such as blood cholesterol levels and glucose levels. Of course, these traditional risk factors are genetic, though typically not explicitly so. In all, there were 44 such risk factors/clinical variables measured and 377,790 single nucleotide polymorphisms (SNPs) genotyped. Data for women we studied are from first visit measurements taken as part of the Atherosclerotic Risk in Communities (ARIC) study. We begin by assessing non-SNP features in their abilities to predict MAP, employing a novel regression technique with two stages, first the discovery of main effects and next discovery of their interactions. The long list of SNPs genotyped is reduced to a manageable list for combining with non-SNP features in prediction. We adapted Efron's local false discovery rate to produce this reduced list. Selected non-SNP and SNP features and their interactions are used to predict MAP using adaptive linear regression. We quantify quality of prediction by an estimated coefficient of determination (R2). We compare the accuracy of prediction with and without information from SNPs

    Proton-transfer-induced 3D/2D hybrid perovskites suppress ion migration and reduce luminance overshoot

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    Abstract: Perovskite light-emitting diodes (PeLEDs) based on three-dimensional (3D) polycrystalline perovskites suffer from ion migration, which causes overshoot of luminance over time during operation and reduces its operational lifetime. Here, we demonstrate 3D/2D hybrid PeLEDs with extremely reduced luminance overshoot and 21 times longer operational lifetime than 3D PeLEDs. The luminance overshoot ratio of 3D/2D hybrid PeLED is only 7.4% which is greatly lower than that of 3D PeLED (150.4%). The 3D/2D hybrid perovskite is obtained by adding a small amount of neutral benzylamine to methylammonium lead bromide, which induces a proton transfer from methylammonium to benzylamine and enables crystallization of 2D perovskite without destroying the 3D phase. Benzylammonium in the perovskite lattice suppresses formation of deep-trap states and ion migration, thereby enhances both operating stability and luminous efficiency based on its retardation effect in reorientation

    Impact of age on sorafenib outcomes in hepatocellular carcinoma: an international cohort study.

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    BACKGROUND: There is no consensus on the effect of sorafenib dosing on efficacy and toxicity in elderly patients with hepatocellular carcinoma (HCC). Older patients are often empirically started on low-dose therapy with the aim to avoid toxicities while maximising clinical efficacy. We aimed to verify whether age impacts on overall survival (OS) and whether a reduced starting dose impacts on OS or toxicity experienced by the elderly. METHODS: In an international, multicentre cohort study, outcomes for those aged 7 cm) (39 vs 33%, p < 0.01) with preserved liver function (67 vs 57.7%) (p < 0.01). No difference in the median OS of those aged ≥75 years and <75 was noted (7.3 months vs 7.2 months; HR 1.00 (95% CI 0.93-1.08), p = 0.97). There was no relationship between starting dose of sorafenib 800 mg vs 400 mg/200 mg and OS between those <75 and ≥75 years. The elderly experienced a similar overall incidence of grade 2-4 sorafenib-related toxicity compared to <75 years (63.5 vs 56.7%, p = 0.11). However, the elderly were more likely to discontinue sorafenib due to toxicity (27.0 vs 21.6%, p < 0.01). This did not vary between different starting doses of sorafenib. CONCLUSIONS: Clinical outcomes in the elderly is equivalent to patients aged <75 years, independent of dose of sorafenib prescribed
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