4,629 research outputs found
Quadrature decomposition of optical fields using two orthogonal phase sensitive amplifiers
We propose a new technique to optically process coherent signals by simultaneously extracting their two (I and Q) quadrature components into two orthogonal polarizations at the same frequency. Two possible implementations are demonstrated
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High-energy guanine nucleotides as a signal capable of linking growth to cellular energy status via the control of gene transcription.
This mini-review considers the idea that guanylate nucleotide energy charge acts as an integrative signal for the regulation of gene expression in eukaryotic cells and discusses possible routes for that signal's transduction. Gene expression is intimately linked with cell nutrition and diverse signaling systems serve to coordinate the synthesis of proteins required for growth and proliferation with the prevailing cellular nutritional status. Using short pathways for the inducible and futile consumption of ATP or GTP in engineered cells of Saccharomyces cerevisiae, we have recently shown that GTP levels can also play a role in determining how genes act to respond to changes in cellular energy supply. This review aims to interpret the importance of GTP as an integrative signal in the context of an increasing body of evidence indicating the spatio-temporal complexity of cellular de novo purine nucleotide biosynthesis
Efficient binary phase quantizer based on phase sensitive four wave mixing
We experimentally demonstrate an efficient binary phase quantizer operating at low pump powers. Phase-sensitive operation is obtained by polarization mixing the phase-locked signal/idler pair in a degenerate dual-pump vector parametric amplifier
Signal regeneration techniques for advanced modulation formats
We review recent results on all-optical regeneration of phase encoded signals based on phase sensitive amplification achieved by avoiding phase-to-amplitude conversion in order to facilitate the regeneration of amplitude/phase encoded (QAM) signals
Novel polarization-assisted phase sensitive optical signal processor requiring low nonlinear phase shifts
We demonstrate a new scheme to achieve binary step-like phase response and high phase-sensitive extinction ratio at low powers. Phase-sensitive operation is achieved by polarization filtering phase-locked signal/idler in a degenerate dual-pump vector parametric amplifier
Investigation into the role of pump to signal power ratio in FWM-based phase preserving amplitude regeneration
We carry out a detailed experimental characterization of a four-wave mixing based amplitude limiter in highly nonlinear fiber based on the Bessel-like power transfer characteristics and highlight trade-offs for phase preserving capabilities
Palliative care medical student education: a cross-sectional medical school survey in mainland China
OBJECTIVE According to the 2015 Quality of
Death Index, China ranks 71st in terms of quality
of palliative care out of 80 countries. Lack of
palliative care education for health professionals
is regarded as largely responsible. The study aims
to evaluate the status of palliative care education
for medical students in mainland China.
METHODS A list of all medical schools was
obtained from the Ministry of Education. A
telephone survey of associate deans responsible
for medical education at all 282 medical schools
in mainland China was conducted in May 2019,
following a standardised protocol. Telephone
interviews focused on attitudes to palliative care
teaching and the extent and manner in which
palliative care is incorporated into the curriculum.
RESULTS Associate deans from 173 (61.2%) of
the 282 medical schools responded. A total of
120 schools (42.5%) completed the interview,
while 53 (18.7%) evaded direct questions related
to palliative care. Of the responding deans,
92 (76.7%) regarded palliative care education
as very important. However, only 11 (9.2%)
provided specific teaching on palliative care. A
few schools (n=18) integrated palliative care
education within required curricula, such as
medical ethics and nursing science. The main
reason reported for not providing palliative
care education was that the medical curriculum
dictated by the Ministry of Education does not
require it.
CONCLUSION A very small minority of medical
schools in mainland China have any formal
teaching about palliative care. Clearly, national
standards for didactic and clinical teaching in
palliative care for medical students and other
health professionals are needed
Selenoprotein expression in the rat colon during Se deficiency.
Selenium is an essential trace element, which is present in several proteins, called seleneproteins, that have various biological roles
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