1,314 research outputs found
ELF3 controls thermoresponsive growth in Arabidopsis
Plant development is highly responsive to ambient temperature, and this trait has been linked to the ability of plants to adapt to climate change [1]. The mechanisms by which natural populations modulate their thermoresponsiveness are not known [2]. To address this, we surveyed Arabidopsis accessions for variation in thermal responsiveness of elongation growth and mapped the corresponding loci. We find that the transcriptional regulator EARLY FLOWERING3 (ELF3) controls elongation growth in response to temperature. Through a combination of modeling and experiments, we show that high temperature relieves the gating of growth at night, highlighting the importance of temperature-dependent repressors of growth. ELF3 gating of transcriptional targets responds rapidly and reversibly to changes in temperature. We show that the binding of ELF3 to target promoters is temperature dependent, suggesting a mechanism where temperature directly controls ELF3 activity
Optical Shaping of Plasma Cavity for Controlled Laser Wakefield Acceleration
Laser wakefield accelerators rely on relativistically moving micron-sized
plasma cavities that provide extremely high electric field >100GV/m. Here, we
demonstrate transverse shaping of the plasma cavity to produce controlled
sub-GeV electron beams, adopting laser pulses with an axially rotatable
ellipse-shaped focal spot. We showed the control capability on electron
self-injection, charge, and transverse profile of the electron beam by rotating
the focal spot. We observed that the effect of the elliptical focal spot was
imprinted in the profiles of the electron beams and the electron energy
increased, as compared to the case of a circular focal spot. We performed 3D
particle-in-cell (PIC) simulations which reproduced the experimental results
and revealed dynamics of a new asymmetric self-injection process. This simple
scheme offers a novel control method on laser wakefield acceleration to produce
tailored electron beams and x-rays for various applications.Comment: 5 pages, 5 figure
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Genetic framework for flowering-time regulation by ambient temperature-responsive miRNAs in Arabidopsis
Flowering is the primary trait affected by ambient
temperature changes. Plant microRNAs
(miRNAs) are small non-coding RNAs playing an
important regulatory role in plant development. In
this study, to elucidate the mechanism of
flowering-time regulation by small RNAs, we
identified six ambient temperature-responsive
miRNAs (miR156, miR163, miR169, miR172, miR398
and miR399) in Arabidopsis via miRNA microarray
and northern hybridization analyses. We also determined
the expression profile of 120 unique miRNA
loci in response to ambient temperature changes by
miRNA northern hybridization analysis. The expression
of the ambient temperature-responsive
miRNAs and their target genes was largely
anticorrelated at two different temperatures (16
and 23 C). Interestingly, a lesion in short vegetative
phase (SVP), a key regulator within the
thermosensory pathway, caused alteration in the
expression of miR172 and a subset of its target
genes, providing a link between a thermosensory
pathway gene and miR172. The miR172-
overexpressing plants showed a temperatureindependent
early flowering phenotype, suggesting
that modulation of miR172 expression leads to temperature
insensitivity. Taken together, our results
suggest a genetic framework for flowering-time regulation
by ambient temperature-responsive
miRNAs under non-stress temperature conditions
Hepatoid adenocarcinoma of the stomach: an unusual case of elevated alpha-fetoprotein with prior treatment for hepatocellular carcinoma
Hepatoid adenocarcinoma (HAC) is a rare type of extrahepatic carcinoma whose morphology is similar to that of hepatocellular carcinoma (HCC). Metachronous HCC and HAC in the same patient is extremely rare. The case of a 68-year-old man with chronic hepatitis B infection who had both HCC and HAC of the stomach is reported herein. Nine years previously this patient had been diagnosed with HCC and received a right lobectomy. HCC that recurred at the caudate lobe at 6 months after the operation was successfully treated with transarterial chemoembolization. The patient was followed up regularly thereafter without evidence of tumor recurrence for 9 years. In July 2010 his serum alpha-fetoprotein (AFP) level elevated from 6.5 ng/mL to 625.4 ng/mL, and he developed a probable single metastatic lymph node around the hepatic artery without intrahepatic lesions. Subsequent evaluation with upper endoscopy revealed a 4-cm ulcerative lesion on the antrum of the stomach. Subtotal gastrectomy was performed with lymph-node dissection. Histologic examination revealed a special type of extrahepatic AFP-producing adenocarcinoma-HAC with lymph-node metastasis-which indicates that HAC can be a cause of elevated AFP even in patients with HCC. HAC should be considered if a patient with stable HCC exhibits unusual elevation of AFP
The Functional Assessment of Cancer Therapy-Prostate (FACT-P) Scales in Men with Prostate Cancer: Reliability and Validity of the Korean Version
The Functional Assessment of Cancer Therapy-Prostate (FACT-P) questionnaire is a relevant, worldwide tool used for assessing the health-related quality of life in men with prostate cancer. The purpose of this study was to translate the FACT-P into Korean, to assess its reliability and validity, and to test its discriminative ability between the cancer patients and normal controls. The Korean version was developed via the FACT multilingual translation project. The translated questionnaire was self-administered to 70 prostate cancer patients and 70 age-matched controls. In evaluating its psychometric properties for cancer patients, internal consistency and test-retest reliability were used. Validity was estimated by using inter-subscale correlations and discriminant validity between cancer patients and controls. Cronbach's alpha coefficient for the individual subscales were 0.7 or greater (range 0.73 to 0.89), except for emotional well-being (0.61). The test-retest reliability showed high correlations (intraclass coefficients ranged from 0.72 to 0.93). Inter-subscale correlations demonstrated each subscale was unrelated, but moderate correlation was observed between social/family well-being and functional well-being subscales (r=0.56). The FACT-P scale could discriminate reliably between the cancer patients and controls in most subscales. In conclusion, the Korean version of the FACT-P is a reliable and valid questionnaire in patients with prostate cancer
Prevalence and Correlates of Depressive Symptoms among North Korean Defectors Living in South Korea for More than One Year
Characteristics, Outcomes and Predictors of Long-Term Mortality for Patients Hospitalized for Acute Heart Failure: A Report From the Korean Heart Failure Registry
BACKGROUND AND OBJECTIVES: Acute heart failure (AHF) is associated with a poor prognosis and it requires repeated hospitalizations. However, there are few studies on the characteristics, treatment and prognostic factors of AHF. The aims of this study were to describe the clinical characteristics, management and outcomes of the patients hospitalized for AHF in Korea.
SUBJECTS AND METHODS: We analyzed the clinical data of 3,200 hospitalization episodes that were recorded between June 2004 and April 2009 from the Korean Heart Failure (KorHF) Registry database. The mean age was 67.6±14.3 years and 50% of the patients were female.
RESULTS: Twenty-nine point six percent (29.6%) of the patients had a history of previous HF and 52.3% of the patients had ischemic heart disease. Left ventricular ejection fraction (LVEF) was reported for 89% of the patients. The mean LVEF was 38.5±15.7% and 26.1% of the patients had preserved systolic function (LVEF ≥50%), which was more prevalent in the females (34.0% vs. 18.4%, respectively, p<0.001). At discharge, 58.6% of the patients received beta-blockers (BB), 53.7% received either angiotensin converting enzyme-inhibitors or angiotensin receptor blockers (ACEi/ARB), and 58.4% received both BB and ACEi/ARB. The 1-, 2-, 3- and 4-year mortality rates were 15%, 21%, 26% and 30%, respectively. Multivariate analysis revealed that advanced age {hazard ratio: 1.023 (95% confidence interval: 1.004-1.042); p=0.020}, a previous history of heart failure {1.735 (1.150-2.618); p=0.009}, anemia {1.973 (1.271-3.063); p=0.002}, hyponatremia {1.861 (1.184-2.926); p=0.007}, a high level of serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) {3.152 (1.450-6.849); p=0.004} and the use of BB at discharge {0.599 (0.360-0.997); p=0.490} were significantly associated with total death.
CONCLUSION: We present here the characteristics and prognosis of an unselected population of AHF patients in Korea. The long-term mortality rate was comparable to that reported in other countries. The independent clinical risk factors included age, a previous history of heart failure, anemia, hyponatremia, a high NT-proBNP level and taking BB at discharge.ope
Electron energy increase in a laser wakefield accelerator using up-ramp plasma density profiles
The phase velocity of the wakefield of a laser wakefield accelerator can, theoretically, be manipulated by shaping the longitudinal plasma density profile, thus controlling the parameters of the generated electron beam. We present an experimental method where using a series of shaped longitudinal plasma density profiles we increased the mean electron peak energy more than 50%, from 175 +/- 1 MeV to 262 +/- 10 MeV and the maximum peak energy from 182 MeV to 363 MeV. The divergence follows closely the change of mean energy and decreases from 58.9 +/- 0.45 mrad to 12.6 +/- 1.2 mrad along the horizontal axis and from 35 +/- 0.3 mrad to 8.3 +/- 0.69 mrad along the vertical axis. Particle-in-cell simulations show that a ramp in a plasma density profile can affect the evolution of the wakefield, thus qualitatively confirming the experimental results. The presented method can increase the electron energy for a fixed laser power and at the same time offer an energy tunable source of electrons.© The Author(s) 201
Nonimmunity against hepatitis B virus infection in patients newly diagnosed with inflammatory bowel disease
Background/AimsThis study aimed to elucidate the prevalence of hepatitis B virus (HBV) serologic markers in Korean patients newly diagnosed with, but not yet treated for inflammatory bowel disease (IBD).MethodsWe prospectively enrolled 210 patients newly diagnosed with IBD (109 with ulcerative colitis and 101 with Crohn's disease). Hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and hepatitis B core antibody (anti-HBc) levels were measured and compared with those of 1,100 sex- and age-matched controls.ResultsThe prevalence of chronic HBV infection (positive HBsAg, positive anti-HBc, and negative anti-HBs results) and past infection (negative HBsAg, positive anti-HBc, and positive or negative anti-HBs results) were not significantly different between the patients and controls (chronic HBV infection: IBD, 3.8% vs. control, 4.9%, P=0.596; past infection: IBD, 26.2% vs. control, 28.8%, P=0.625). The patients with IBD aged <20 years were at a higher susceptibility risk (nonimmune) for HBV infection than the controls (IBD, 41.5% vs. control, 22.4%; P=0.018). In the multivariate analysis, an age of <20 years (P=0.024) and symptom duration of ≥12 months before diagnosis (P=0.027) were identified as independent risk factors for nonimmunity against HBV infection.ConclusionsThe patients newly diagnosed with IBD were susceptible to HBV infection. The frequency of nonimmunity was high, especially in the patients aged <20 years and those with a longer duration of symptoms before diagnosis. Therefore, it is necessary to screen for HBV serologic markers and generate a detailed vaccination plan for patients newly diagnosed with IBD
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