High-throughput intensity diffraction tomography with a computational microscope

We demonstrate a motion-free intensity diffraction tomography technique that enables direct inversion of 3D phase and absorption from intensity-only measurements for weakly scattering samples. We derive a novel linear forward model, featuring slice-wise phase and absorption transfer functions using angled illumination. This new framework facilitates flexible and efficient data acquisition, enabling arbitrary sampling of the illumination angles. The reconstruction algorithm performs 3D synthetic aperture using a robust, computation and memory efficient slice-wise deconvolution to achieve resolution up to the incoherent limit. We demonstrate our technique with thick biological samples having both sparse 3D structures and dense cell clusters. We further investigate the limitation of our technique when imaging strongly scattering samples. Imaging performance and the influence of multiple scattering is evaluated using a 3D sample consisting of stacked phase and absorption resolution targets. This computational microscopy system is directly built on a standard commercial microscope with a simple LED array source add-on, and promises broad applications by leveraging the ubiquitous microscopy platforms with minimal hardware modifications

High-throughput intensity diffraction tomography with a computational microscope

We demonstrate a motion-free intensity diffraction tomography technique that enables direct inversion of 3D phase and absorption from intensity-only measurements for weakly scattering samples. We derive a novel linear forward model, featuring slice-wise phase and absorption transfer functions using angled illumination. This new framework facilitates flexible and efficient data acquisition, enabling arbitrary sampling of the illumination angles. The reconstruction algorithm performs 3D synthetic aperture using a robust, computation and memory efficient slice-wise deconvolution to achieve resolution up to the incoherent limit. We demonstrate our technique with thick biological samples having both sparse 3D structures and dense cell clusters. We further investigate the limitation of our technique when imaging strongly scattering samples. Imaging performance and the influence of multiple scattering is evaluated using a 3D sample consisting of stacked phase and absorption resolution targets. This computational microscopy system is directly built on a standard commercial microscope with a simple LED array source add-on, and promises broad applications by leveraging the ubiquitous microscopy platforms with minimal hardware modifications

Use of sodium bicarbonate for acute dizziness after minor head injury

AbstractObjectiveDizziness after minor head injury (mHI) is common. In some eastern countries, it is treated with 7% sodium bicarbonate solution (SB). This prospective study evaluated the clinical efficacy of SB compared with normal saline (NS).Material and methodsFrom April 2009 to April 2010, we performed a prospective observational study on 228 patients (68% female, 32% male) with acute dizziness after mHI. At the emergency physician’s discretion, intravenous SB (1 mL/kg) in NS (250 mL) or NS (250 mL) was administered to 166 patients and 62 patients, respectively, as empiric antidizziness therapy. Outcome measures were severity of dizziness and treatment response, which were measured by a visual analog scale. Various characteristics were compared between treatment groups. Any continued dizziness of the patients during follow-up was also compared with their pre-injury condition, such as prior psychiatric disorders and the presence of vertigo.ResultsThe SB group had their visual analog scale scores reduced by 25.4% compared with 24.6% in the NS group. Both groups showed a statistically significant reduction in dizziness (p < 0.001); however, the dizziness improvement did not differ significantly between the two treatment groups (p = 0.699). Sixty-four patients (28.1%) suffered from continued dizziness during follow-up (mean period, 22.4 ± 28.9 days). The prevalence of continued dizziness was higher in patients with prior psychiatric disorders, although this was not statistically significant (40% vs. 27.2%, p = 0.276), whereas patients with prior vertigo did not experience a higher dizziness relapse rate (27% vs. 28.2%).ConclusionsSB and NS administrations are both effective individually when treating patients with acute dizziness from mHI; however, both results may be attributable to the placebo effect. Therefore more research is necessary to understand the complex conditions that determine the effects of SB on this disorder

OSSOS III - Resonant Trans-Neptunian Populations: Constraints from the first quarter of the Outer Solar System Origins Survey

The first two observational sky "blocks" of the Outer Solar System Origins Survey (OSSOS) have significantly increased the number of well-characterized observed trans-Neptunian objects (TNOs) in Neptune's mean motion resonances. We describe the 31 securely resonant TNOs detected by OSSOS so far, and we use them to independently verify the resonant population models from the Canada-France Ecliptic Plane Survey (CFEPS; Gladman et al. 2012), with which we find broad agreement. We confirm that the 5:2 resonance is more populated than models of the outer Solar System's dynamical history predict; our minimum population estimate shows that the high eccentricity (e>0.35) portion of the resonance is at least as populous as the 2:1 and possibly as populated as the 3:2 resonance. One OSSOS block was well-suited to detecting objects trapped at low libration amplitudes in Neptune's 3:2 resonance, a population of interest in testing the origins of resonant TNOs. We detected three 3:2 objects with libration amplitudes below the cutoff modeled by CFEPS; OSSOS thus offers new constraints on this distribution. The OSSOS detections confirm that the 2:1 resonance has a dynamically colder inclination distribution than either the 3:2 or 5:2 resonances. Using the combined OSSOS and CFEPS 2:1 detections, we constrain the fraction of 2:1 objects in the symmetric mode of libration to be 0.2-0.85; we also constrain the fraction of leading vs. trailing asymmetric librators, which has been theoretically predicted to vary depending on Neptune's migration history, to be 0.05-0.8. Future OSSOS blocks will improve these constraints.Comment: Accepted for publication in A

E2F transcription factor 1 overexpression as a poor prognostic factor in patients with nasopharyngeal carcinomas

AbstractNasopharyngeal carcinoma (NPC) is an endemic head and neck epithelial malignancy in Southeastern Asia and Taiwan. The E2 factor (E2F) family of transcription factors is downstream targets of the retinoblastoma protein 1. The E2F family of transcription factors is the key regulator of genes involved in cell cycle progression, cell fate determination, DNA damage repair and apoptosis. E2F1 is unique in that it contributes both to the control of cellular proliferation and cellular death. However, the expression of E2F1 protein and its clinicopathological associations in patients with NPC are yet to be evaluated. Immunoexpression of E2F1 was retrospectively assessed in biopsies of 124 consecutive NPC patients without initial distant metastasis and treated with consistent guidelines. The outcomes were correlated with clinicopathological features and patient survivals. Results indicated that high E2F1 protein level (50%) was correlated with primary tumor (p < 0.001) and stage (p = 0.002; 7th American Joint Committee on Cancer). In multivariate analyses, high E2F1 expression emerged as an independent prognosticator for worse disease-specific survival (p = 0.003), distal metastasis-free survival (p = 0.003), and local recurrence-free survival (p = 0.039). In conclusion, high E2F1 protein level is common, associated with adverse prognosticators, and might confer tumor aggressiveness through tumor cell proliferation and metastasis

Decentralized Base-Graph Routing for the Quantum Internet

Quantum repeater networks are a fundamental of any future quantum Internet and long-distance quantum communications. The entangled quantum nodes can communicate through several different levels of entanglement, leading to a heterogeneous, multi-level network structure. The level of entanglement between the quantum nodes determines the hop distance and the probability of the existence of an entangled link in the network. Here, we define a decentralized routing for entangled quantum networks. The proposed method allows an efficient routing to find the shortest paths in entangled quantum networks by using only local knowledge of the quantum nodes. We give bounds on the maximum value of the total number of entangled links of a path. The proposed scheme can be directly applied in practical quantum communications and quantum networking scenarios.Comment: 13 pages, Journal-ref: Phys. Rev.