2,272 research outputs found
Moxifloxacin: Clinically compatible contrast agent for multiphoton imaging
Multiphoton microscopy (MPM) is a nonlinear fluorescence microscopic technique widely used for cellular imaging of thick tissues and live animals in biological studies. However, MPM application to human tissues is limited by weak endogenous fluorescence in tissue and cytotoxicity of exogenous probes. Herein, we describe the applications of moxifloxacin, an FDA-approved antibiotic, as a cell-labeling agent for MPM. Moxifloxacin has bright intrinsic multiphoton fluorescence, good tissue penetration and high intracellular concentration. MPM with moxifloxacin was demonstrated in various cell lines, and animal tissues of cornea, skin, small intestine and bladder. Clinical application is promising since imaging based on moxifloxacin labeling could be 10 times faster than imaging based on endogenous fluorescence.1152sciescopu
Load-Balancing for Parallel Delaunay Triangulations
Computing the Delaunay triangulation (DT) of a given point set in
is one of the fundamental operations in computational geometry.
Recently, Funke and Sanders (2017) presented a divide-and-conquer DT algorithm
that merges two partial triangulations by re-triangulating a small subset of
their vertices - the border vertices - and combining the three triangulations
efficiently via parallel hash table lookups. The input point division should
therefore yield roughly equal-sized partitions for good load-balancing and also
result in a small number of border vertices for fast merging. In this paper, we
present a novel divide-step based on partitioning the triangulation of a small
sample of the input points. In experiments on synthetic and real-world data
sets, we achieve nearly perfectly balanced partitions and small border
triangulations. This almost cuts running time in half compared to
non-data-sensitive division schemes on inputs exhibiting an exploitable
underlying structure.Comment: Short version submitted to EuroPar 201
Comparison of post-treatment plasma EBV DNA with nasopharyngeal biopsy in patients after radical (chemo) radiotherapy for non-metatatic nasopharyngeal cancer
This journal suppl. entitled: Proceedings of the American Society for Radiation Oncology 56th Annual Meeting, ASTRO's 56th Annual Meeting ... 2014Oral Scientific SessionPURPOSE/OBJECTIVE(S): Random nasopharyngeal biopsy after completion of intensity-modulated radiation therapy (IMRT) for non-metastatic nasopharyngeal cancer (NPC) is routinely practiced in Hong Kong to confirm local remission. Plasma EBV DNA is proven an accurate marker for NPC. We carried out a prospective study comparing the correlation between post-IMRT nasopharyngeal biopsy and EBV DNA, to investigate if EBV DNA can substitute biopsy to confirm local remission.
MATERIALS/METHODS: Patients with non-metastatic NPC treated with definitive (chemo) IMRT diagnosed between January 2011 and March 2013 were recruited. After baseline workup ...postprin
Acute cardiac injury after subarachnoid haemorrhage: two case reports
It is well known that cardiopulmonary complications are often associated to subarachnoid haemorrhage. For appropriate therapeutic managing it is very important to distinguish acute coronary syndrome from neurogenic myocardial injury, which is a reversible condition. Furthermore, because the hearts of brain dead patients may be utilized for therapeutic purpose, it has became of importance to rule out erroneous diagnosis of cardiac ischemia in order to avoid rejection of hearts potential suitable for transplantation
Different definition of sarcopenia and mortality in cancer: A meta-analysis
Objectives: Sarcopenia has been an emerging theme in clinical oncology. Various definitions of sarcopenia have been proposed, but their prognostic performance have yet to be evaluated and compared. The aim of this meta-analysis is to comprehensively evaluate the performance of different cutoff definitions of sarcopenia in cancer mortality prognostication. /
Methods: This is a meta-analysis. Cohort studies on lean mass and mortality published before December 20, 2017 were obtained by systematic search on PubMed, Cochrane Library, and Embase. Inclusion criteria were cohort studies reporting binary lean mass categorized according to clearly defined cutoffs, and with all-cause mortality as study outcome. Studies were stratified according to the cutoff(s) used in defining low lean mass. The cutoff-specific hazard ratios (HRs) and 95% confidence intervals (CIs) of low lean mass on cancer mortality were pooled with a random-effects model and compared. /
Results: Altogether 81 studies that studied binary lean mass were included. The pooled HRs on cancer mortality using the 3 most used definitions were: 1.74 (95% CI, 1.46–2.07) using the definition proposed by International Consensus of Cancer Cachexia, 1.45 (95% CI, 1.21–1.75) using that by Martin, and 1.58 (95% CI, 1.35–1.84) using that by Prado. The associations between sarcopenia and cancer mortality using other definitions were all statistically significant, despite different estimates were observed. /
Conclusions: The association of low lean mass with increased mortality was consistent across different definitions; this provides further evidence on the poorer survival in cancer patients with sarcopenia. However, further studies evaluating the performance of each definition are warranted
Stroke from A Large Left Atrial Myxoma
A 36-year-old male involved in a car accident was found to have an embolic stroke due to a left atrial myxoma. Open heart surgery was delayed 4 weeks to decrease the risk of neurologic complications from the anticoagulation required for cardiopulmonary bypass. After resection of the myxoma, intraoperative transesophageal echocardiography found severe mitral regurgitation, which was repaired
Topoisomer Differentiation of Molecular Knots by FTICR MS: Lessons from Class II Lasso Peptides
Lasso peptides constitute a class of bioactive peptides sharing a knotted
structure where the C-terminal tail of the peptide is threaded through and
trapped within an N-terminalmacrolactamring. The structural characterization of
lasso structures and differentiation from their unthreaded topoisomers is not
trivial and generally requires the use of complementary biochemical and
spectroscopic methods. Here we investigated two antimicrobial peptides
belonging to the class II lasso peptide family and their corresponding
unthreaded topoisomers: microcin J25 (MccJ25), which is known to yield
two-peptide product ions specific of the lasso structure under collisioninduced
dissociation (CID), and capistruin, for which CID does not permit to
unambiguously assign the lasso structure. The two pairs of topoisomers were
analyzed by electrospray ionization Fourier transform ion cyclotron resonance
mass spectrometry (ESI-FTICR MS) upon CID, infrared multiple photon
dissociation (IRMPD), and electron capture dissociation (ECD). CID and
ECDspectra clearly permitted to differentiate MccJ25 from its non-lasso
topoisomer MccJ25-Icm, while for capistruin, only ECD was informative and
showed different extent of hydrogen migration (formation of c\bullet/z from
c/z\bullet) for the threaded and unthreaded topoisomers. The ECD spectra of the
triply-charged MccJ25 and MccJ25-lcm showed a series of radical b-type product
ions {\eth}b0In{\TH}. We proposed that these ions are specific of
cyclic-branched peptides and result from a dual c/z\bullet and y/b
dissociation, in the ring and in the tail, respectively. This work shows the
potentiality of ECD for structural characterization of peptide topoisomers, as
well as the effect of conformation on hydrogen migration subsequent to electron
capture
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Burnout and work-related stressors in gastroenterology: a protocol for a multinational observational study in the ASEAN region.
BACKGROUND: Clinician burnout is an important occupational hazard that may be exacerbated by the novel COVID-19 pandemic. Within Southeast Asia, burnout in gastroenterology is understudied. The primary objective of this study is to estimate the prevalence of burnout symptoms within gastroenterology, in member states of the Associations of Southeast Asian Nations (ASEAN), during and after the COVID-19 pandemic. The secondary objective is to identify work-related stressors that contribute to burnout in ASEAN gastroenterologists. METHODS AND ANALYSIS: This is an observational study that will use anonymised online surveys to estimate the prevalence of burnout symptoms at two time points: during the COVID-19 pandemic in 2020 and in 2022 (assumed to be after the pandemic). Gastroenterologists from Singapore, Malaysia, Thailand, Indonesia, Philippines and Brunei will be invited to participate in the online survey through their national gastroenterology and endoscopy societies. Burnout will be assessed using the Maslach Burnout Inventory-Human Services Survey tool. Supplementary questions will collect demographic and qualitative data. Associations between demographic characteristics and burnout will be tested by multiple regression. RESULTS: The prevalence of burnout symptoms in gastroenterology during the COVID-19 pandemic, and the baseline prevalence after COVID-19, will be established in the above-mentioned countries. Work-related stressors commonly associated with burnout will be identified, allowing the introduction of preventative measures to reduce burnout in the future. ETHICS AND DISSEMINATION: Ethical approval was granted by the Singhealth Centralised Institutional Review Board (2020/2709). Results will be submitted for publication
Strained graphene structures: from valleytronics to pressure sensing
Due to its strong bonds graphene can stretch up to 25% of its original size
without breaking. Furthermore, mechanical deformations lead to the generation
of pseudo-magnetic fields (PMF) that can exceed 300 T. The generated PMF has
opposite direction for electrons originating from different valleys. We show
that valley-polarized currents can be generated by local straining of
multi-terminal graphene devices. The pseudo-magnetic field created by a
Gaussian-like deformation allows electrons from only one valley to transmit and
a current of electrons from a single valley is generated at the opposite side
of the locally strained region. Furthermore, applying a pressure difference
between the two sides of a graphene membrane causes it to bend/bulge resulting
in a resistance change. We find that the resistance changes linearly with
pressure for bubbles of small radius while the response becomes non-linear for
bubbles that stretch almost to the edges of the sample. This is explained as
due to the strong interference of propagating electronic modes inside the
bubble. Our calculations show that high gauge factors can be obtained in this
way which makes graphene a good candidate for pressure sensing.Comment: to appear in proceedings of the NATO Advanced Research Worksho
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