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91.
Aynajian P da Silva Neto EH Gyenis A Baumbach RE Thompson JD Fisk Z Bauer ED Yazdani A 《Nature》2012,486(7402):201-206
In solids containing elements with f orbitals, the interaction between f-electron spins and those of itinerant electrons leads to the development of low-energy fermionic excitations with a heavy effective mass. These excitations are fundamental to the appearance of unconventional superconductivity and non-Fermi-liquid behaviour observed in actinide- and lanthanide-based compounds. Here we use spectroscopic mapping with the scanning tunnelling microscope to detect the emergence of heavy excitations with lowering of temperature in a prototypical family of cerium-based heavy-fermion compounds. We demonstrate the sensitivity of the tunnelling process to the composite nature of these heavy quasiparticles, which arises from quantum entanglement of itinerant conduction and f electrons. Scattering and interference of the composite quasiparticles is used to resolve their energy-momentum structure and to extract their mass enhancement, which develops with decreasing temperature. The lifetime of the emergent heavy quasiparticles reveals signatures of enhanced scattering and their spectral lineshape shows evidence of energy-temperature scaling. These findings demonstrate that proximity to a quantum critical point results in critical damping of the emergent heavy excitation of our Kondo lattice system. 相似文献
92.
Yiannis Laouris Ali Erel Marios Michaelides Mustafa Damdelen Tatjana Taraszow Ilke Dagli Romina Laouri Aleco Christakis 《Systemic Practice and Action Research》2009,22(5):361-381
This paper summarizes results of a co-laboratory that took place 33 months after the negative outcome of the referendum on the UN’s proposal for the solution of the Cyprus problem, and which was a follow-up (3 months later) of a previous co-laboratory. The earlier co-laboratory explored factors contributing to the increasing gap between the two conflicting communities. The co-laboratory reported here engaged relevant stakeholders (peace pioneers, academics, business people, activists and others representing the Turkish and Greek speaking communities of Cyprus) to come up with options aiming to enhance the social dialogue between the two communities. The Structured Dialogic Design Process was used to structure 27 proposed options and develop an influence map. The deep drivers, i.e., most influential factors, determined decisions taken by the participating peace pioneers regarding their future interventions. The results are also discussed within the framework of current (analysis reflects the political situation during the period reported here) political developments. 相似文献
93.
Electronic medical records (EMR) are generally used by nurses in hospitals. However, studies investigating views on and evaluations of EMR by nurses are limited in Turkey and in other countries around the world. In this study, nurses’ views on EMR systems were investigated in terms of “Nursing care management”, “Order entry”, “Information Management”, “Information quality”, “Service quality”, “Impact of EMR system on clinical care”. The purpose of this study was to investigate the views/perceptions on EMR used by nurses working at hospital clinics in Turkey. The research questions were: (a) What are nurses’ perceptions on EMR? (b) Were there relationships among nurses’ perceptions on EMR? (c) Were there differences among nurses’ perceptions on EMR according to hospitals in Turkey. This study is composed of field research conducted using questionnaires. To prepare the data-measuring instrument, the literature on EMR was reviewed. A Likert scale type was used in this questionnaire. The study was planned and conducted on nurses working at inpatient care units at four Turkish hospitals. At the end of this study, the questionnaire had been conducted on 517 nurses. Total response rate is 66.70 %. We found that the Information quality of EMR, impact of EMR system on clinical care and service quality were high level. Information quality has the highest mean score. EMR system is an important system for nurses’ hospital has the highest mean score in this study. Nurses feel about impact of EMR system on clinical care that generally ‘EMR system’s usefulness’, ‘improving quality of information due to EMR system’, ‘improving quality of nurses’ work’, ‘improving quality of information due to EMR system’. All of the six subscales of EMR were positively correlated with each other. This study revealed that there are significant differences among the mean scores for six subscales according to the ownership of hospitals. EMR systems were not well integrated into their workflow. In addition, half of all respondents had not been trained in using EMR systems. This study will added to evaluation views and assessments of nurses about EMR literature. The results will assist in determining “Information quality”, “Service quality”, of EMR, and “Impact of EMR system on clinical for nurses in Turkish health system”. This survey suggests that nurses favor the use of an EMR and suggests opportunities for EMR enhancement. 相似文献
94.
Muhammad Mehmood Shahi Ahmad H. Ismail Ali MA. Abdul Amir AL-Mokaram R. Vikneswaran Sohail Ahm Amir Hamz Arshid Numan 《自然科学进展(英文版)》2017,27(5):582-587
Nitrogen-doped reduced graphene oxide(NrGO)sheets decorated with Co(OH)_2nanoflakes were prepared by a single-step hydrothermal process.The morphological and structural characterizations of as synthesized Nr GO@Co(OH)_2nanoflakes were performed by field emission scanning electron microscopy(FESEM),EDX-mapping and X-ray diffraction(XRD).Nr GO@Co(OH)_2nanoflakes modified glassy carbon electrode(GCE)was used for electrochemical sensing of dopamine in neutral medium.The nanocomposite modified electrode showed enhanced electrochemical sensing ability for the detection of dopamine and the limit of detection(Lo D)was found to be 0.201μM with a sensitivity value of 0.0286±0.002 m A m M~(-1).Interference studies revealed that Nr GO@Co(OH)_2─GCE endow excellent selectivity for DA detection even in the presence of higher concentration of common co-existing physiological interfering analytes.Additionally,proposed sensor demonstrated excellent performance in urine samples with promising reproducibility and stability. 相似文献
95.
96.
Heat shock protein gene expression during Xenopus development 总被引:2,自引:0,他引:2
J. J. Heikkila N. Ohan Y. Tam A. Ali 《Cellular and molecular life sciences : CMLS》1997,53(1):114-121
Stress-induced heat shock protein gene expression is developmentally regulated during early embryogen esis of the frog, Xenopus laevis. For example, a number of heat shock protein genes, such as hsp70,
hsp90, and ubiquitin are not heat-inducible until after the midblastula stage of embryogenesis. Furthermore, the family of small heat shock protein
genes, hsp30, are differentially expressed after the midblastula stage as well as being regulated at the level of mRNA stability. Many
of these stress proteins are also synthesized constitutively during oogenesis and embryogenesis during which they may act
as molecular chaperones as well as being involved in sequestering proteins in an inactive state until required by the developing
embryo. Furthermore the induction of these stress protein genes has been correlated with enhanced thermoresistance. During
stressful conditions heat shock proteins probably prevent aggregation or misfolding of damaged protei
ns within the embryo. 相似文献
97.
98.
Ferrari MJ Grais RF Bharti N Conlan AJ Bjørnstad ON Wolfson LJ Guerin PJ Djibo A Grenfell BT 《Nature》2008,451(7179):679-684
Although vaccination has almost eliminated measles in parts of the world, the disease remains a major killer in some high birth rate countries of the Sahel. On the basis of measles dynamics for industrialized countries, high birth rate regions should experience regular annual epidemics. Here, however, we show that measles epidemics in Niger are highly episodic, particularly in the capital Niamey. Models demonstrate that this variability arises from powerful seasonality in transmission-generating high amplitude epidemics-within the chaotic domain of deterministic dynamics. In practice, this leads to frequent stochastic fadeouts, interspersed with irregular, large epidemics. A metapopulation model illustrates how increased vaccine coverage, but still below the local elimination threshold, could lead to increasingly variable major outbreaks in highly seasonally forced contexts. Such erratic dynamics emphasize the importance both of control strategies that address build-up of susceptible individuals and efforts to mitigate the impact of large outbreaks when they occur. 相似文献
99.
Summary UV-irradiation of phenylalanine by 253.7 nm light in the presence of hydrogen peroxide formed 5 ninhydrin reactive products and ammonia. Four of them were identified as aspartic acid, serine, alanine and lysine.Acknowledgments. This work was supported by the Council of Scientific and Industrial Research. Thanks are due to the Head of the Department for facilities and to. Mr.Rakesh C. Sharma for help. 相似文献
100.
N. M. Ali 《Cellular and molecular life sciences : CMLS》1984,40(2):197-198
Summary Experimental infection byDiplostomum phoxini of the brain of laboratory hatched and rearedPhoxinus phoxinus induces the migration along the Xth cranial nerve of periodic acid Schiff positive granular leucocytes (PAS-GLs). These differentiate and grow into cells that lie between the parasite and the neurones of the host. The transformed cells are associated with elevated levels of heparin and serotonin in the brain; little histamine was detected. The reactive cell is identified as a mast cell.This work was carried out with M.R.L. Johnston's guidance. Teresa Townshend is thanked for assistance with techniques to hatch and raiseP. phoxinus. 相似文献