3,905 research outputs found
Left ventricular dysfunction measured by tissue Doppler imaging and strain rate imaging in hypertensive adolescents
Purpose : Left ventricular (LV) hypertrophy and impaired diastolic function may occur early in systemic hypertension. Diastolic dysfunction is associated with increased cardiovascular risk. Tissue Doppler imaging (TDI)-derived tissue velocity and strain rate are new parameters for assessing diastolic dysfunction. The aim of this study is to determine whether TDI and strain rate imaging (SRI) would improve the ability to recognize early impaired diastolic and systolic functions compared with conventional echocardiography in hypertensive adolescents. Methods : We included 38 hypertensive patients with systolic blood pressure above 140 mmHg or diastolic blood pressure above 90 mmHg. Ejection fraction and myocardial performance index (MPI) were estimated by conventional echocardiography. Peak systolic myocardial velocity, early diastolic myocardial velocity (Em), and peak late diastolic myocardial velocity (Am) were obtained by using TDI and SRI. Results : In the hypertensive group, interventricular septal thickness was significantly increased on M-mode echocardiography. Em/Am was significantly decreased at the mitral valve annulus. Among hypertensive subjects, the E strain rate at basal, mid, and apex was significantly decreased. Systolic strain was significantly decreased at the septum in the hypertensive group. Conclusion : Strain rate might be a useful new parameter for the quantification of both regional and global LV functions and could be used in long-term follow up in hypertensive patients. Early identification by SRI of subjects at risk for hypertensive and ventricular dysfunction may help to stratify risk and guide therapy. Further studies, including serial assessment of LV structure and function in a larger number of adolescents with hypertension, is necessary
Reproductive output, foraging destinations, and isotopic niche of olive ridley and loggerhead sea turtles, and their hybrids, in Brazil
Hybridization is a fundamental evolutionary and ecological process with significant conservation ramifications. Sea turtle hybridization occurs at unusually high frequencies along the northeastern coast of Brazil. To better understand the process, we studied the reproductive output, migration patterns (through satellite telemetry), and isotopic niches of loggerhead turtles Caretta caretta and olive ridley turtles Lepidochelys olivacea and their hybrids. We classified 154 nesting females as loggerhead (n = 91), olive ridley (n = 38), or hybrid (n = 25) based on mitochondrial and nuclear DNA. Further, we compared nesting female morphological data and reproductive parameters (clutch size, emergence success, hatchling production, incubation period) of 405 nests among hybrids and parental species. We found no significant differences among the 3 groups when hatchling production was corrected for female body size, indicating that hybrids and parental species produce similar numbers of hatchlings per clutch. Satellite tracking of 8 post-nesting hybrid females revealed shared foraging grounds with both parental species, as well as neritic migrations between foraging and nesting areas similar to those previously reported for loggerheads and olive ridleys. Analyses of 13C and 15N isotope values (n = 69) further confirmed this pattern, as hybrid isotopic niches overlapped extensively with both parental species. Thus, given the similarities presented between hybrids and their parental species in reproductive, ecological, and behavioral characteristics, we conclude that these hybrids may persist along with other sea turtle nesting populations in the area, with research and conservation implications. © The authors 2021. Open Access under Creative Commons by Attribution Licence. Use, distribution and reproduction are unrestricted. Authors and original publication must be credited
Temporal change in India’s imbalance of carbon emissions embodied in international trade
In India, rapid industrialization and reorganization of the global supply chain are driving economic growth, accompanied by increasing exports and carbon emissions. India is poised to succeed China as the next world manufactory, which will lead to huge emissions in the country. To formulate appropriate emission mitigation measures, it is necessary to further understand the temporal change in India’s emissions at the sectoral level from both the production and consumption perspectives. However, existing studies that have estimated emissions in India have paid less attention to the link among original emitters, final producers and final consumers and to its temporal change. Based on an emission inventory compiled in this study, we trace emission flows from original emitters to final producers and then to final consumers through the international supply chain by using an environmentally extended multi-regional input-output model. This study finds that both production-based and consumption-based emissions in India increased constantly from 2000 to 2014, and production-based emissions had higher growth rates due to the increased coal share. The major receivers of India’s exported emissions were developed countries (e.g., the European Union and the United States), while the main sources of India’s imported emissions were developing countries (e.g., China and Russia). From 2011 to 2014, India’s net exported emissions increased by 29.2% because of the decrease of imported emissions. Moreover, intermediate products (63% and 73.7%) were the major contributors to exported and imported emissions, most of which were embodied in manufacturing products (48.8% and 65.7%, respectively). Therefore, international cooperation to optimize the energy and trade structure and to improve energy efficiency can be effective in mitigating carbon emissions in India
Non-invasive characterization of transverse beam emittance of electrons from a laser-plasma wakefield accelerator in the bubble regime using betatron x-ray radiation
We propose and use a technique to measure the transverse emittance of a
laser-wakefield accelerated beam of relativistic electrons. The technique is
based on the simultaneous measurements of the electron beam divergence given by
, the measured longitudinal spectrum
and the transverse electron bunch size in the bubble
. The latter is obtained via the measurement of the source size of
the x-rays emitted by the accelerating electron bunch in the bubble. We measure
a \textit{normalised} RMS beam transverse emittance mmmrad as
an upper limit for a spatially gaussian, spectrally quasi-monoenergetic
electron beam with 230 MeV energy in agreement with numerical modeling and
analytic theory in the bubble regime.Comment: 4 pages, 5 figure
Children and older adults exhibit distinct sub-optimal cost-benefit functions when preparing to move their eyes and hands
"© 2015 Gonzalez et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited"Numerous activities require an individual to respond quickly to the correct stimulus. The provision of advance information allows response priming but heightened responses can cause errors (responding too early or reacting to the wrong stimulus). Thus, a balance is required between the online cognitive mechanisms (inhibitory and anticipatory) used to prepare and execute a motor response at the appropriate time. We investigated the use of advance information in 71 participants across four different age groups: (i) children, (ii) young adults, (iii) middle-aged adults, and (iv) older adults. We implemented 'cued' and 'non-cued' conditions to assess age-related changes in saccadic and touch responses to targets in three movement conditions: (a) Eyes only; (b) Hands only; (c) Eyes and Hand. Children made less saccade errors compared to young adults, but they also exhibited longer response times in cued versus non-cued conditions. In contrast, older adults showed faster responses in cued conditions but exhibited more errors. The results indicate that young adults (18 -25 years) achieve an optimal balance between anticipation and execution. In contrast, children show benefits (few errors) and costs (slow responses) of good inhibition when preparing a motor response based on advance information; whilst older adults show the benefits and costs associated with a prospective response strategy (i.e., good anticipation)
Performance Assessment and Outlook of China’s Emission-Trading Scheme
China overtook the US as the world’s top emitter in 2007, and produced 1.5 times the emissions of the US by 2013 [1]. At present, China’s emissions make up over a quarter of the global total. China is expected to produce three times the emissions of the US by 2030 [2]. Indeed, China’s role and efforts in CO2 reductions matter greatly for the peaking of global emissions, even without further emission leakages to less-developed regions or countries. China recently announced the launch of a nation-wide emission-trading scheme (ETS) starting in 2017 [3] in order to help deliver its emission peak by 2030. A number of climate policies in China are ongoing, and require a full performance review, effective coordination, and appropriate implementation of planning and monitoring measures along with any newly added mechanisms. This paper utilizes the latest energy and emission data to explore the impact of emission trading as a policy driver toward absolute emission and emission intensity changes in China and in its seven provinces or municipalities
Spin-injection Hall effect in a planar photovoltaic cell
Successful incorporation of the spin degree of freedom in semiconductor
technology requires the development of a new paradigm allowing for a scalable,
non-destructive electrical detection of the spin-polarization of injected
charge carriers as they propagate along the semiconducting channel. In this
paper we report the observation of a spin-injection Hall effect (SIHE) which
exploits the quantum-relativistic nature of spin-charge transport and which
meets all these key requirements on the spin detection. The two-dimensional
electron-hole gas photo-voltaic cell we designed to observe the SIHE allows us
to develop a quantitative microscopic theory of the phenomenon and to
demonstrate its direct application in optoelectronics. We report an
experimental realization of a non-magnetic spin-photovoltaic effect via the
SIHE, rendering our device an electrical polarimeter which directly converts
the degree of circular polarization of light to a voltage signal.Comment: 14 pages, 4 figure
Capecitabine and Vinorelbine in Patients with Metastatic Breast Cancer Previously Treated with Anthracycline and Taxane
We have evaluated the efficacy and safety of the combination of capecitabine and vinorelbine in metastatic breast cancer (MBC) patients previously treated with anthracycline-and taxane-containing regimens. Between April 2000 and September 2002, 44 female MBC patients received oral capecitabine (1,250 mg/m2 twice daily on days 114), and intravenous vinorelbine (25 mg/m2 on days 1 and 8) during each 3 week-chemotherapy cycle (median, 5 cycles/patient; total, 235 cycles). One patient achieved a complete response and 21 patients had partial responses, giving an overall response rate of 50% in the intention-to-treat analysis (95% CI, 35.0-65.0%). Median duration of response was 6.0 months (range 1.2-23.0 months). Patients were followed-up for a median of 16 months, with median progression-free survival being 5.3 months, and median overall survival being 17 months. Toxicities included grades III and IV neutropenia in 63 (26.8%) and 4 (1.7%) cycles, respectively, and grades II and III hand-foot syndrome in 12 (5.1%) and 4 (1.7%) cycles, respectively. Other nonhematologic toxicities were minimal and manageable. In conclusion, the combination of capecitabine and vinorelbine was effective and well tolerated in MBC patients even after treatment with anthracyclines and taxanes
Treatment of Solitary Extramedullary Plasmacytoma of the Stomach with Endoscopic Submucosal Dissection
Extramedullary plasmacytoma (EMP) is an uncommon manifestation of plasma cell neplasia, which occurs outside the bone marrow. Intestinal involvement usually occur secondarily in multiple myeloma but it occur primarily less commonly. We experienced a woman who had a primary EMP localized in the stomach and the EMP was removed successfully by endoscopic submucosal dissection. The lesion was pathologically confirmed as confined to the gastric mucosa
Loquat (Eriobotrya japonica) extracts suppress the adhesion, migration and invasion of human breast cancer cell line
We examined the inhibitory effects of loquat methanol extract on the adhesion, migration, invasion and matrix metalloproteinase (MMP) activities of MDA-MB-231 human breast cancer cell line. Cells were cultured with DMSO or with 10, 25, or 50 µg/ml of loquat methanol extract. Both leaf and seed extracts significantly inhibited growth of MDA-MB-231 cells in a dose-dependent manner, although leaf extract was more effective. Adhesion and migration were significantly inhibited by loquat extracts in a dose-dependent manner. Loquat extract also inhibited the invasion of breast cancer cells in a dose-dependent manner and leaf extract was more effective than seed extract. MMP-2 and MMP-9 activities were also inhibited by loquat extract. Our results indicate that methanol extracts of loquat inhibit the adhesion, migration and invasion of human breast cancer cells partially through the inhibition of MMP activity and leaf extract has more anti-metastatic effects in cell based assay than seed extract. Clinical application of loquat extract as a potent chemopreventive agent may be helpful in limiting breast cancer invasion and metastasis
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