Introduction: The purpose of this study is to determine the success and complication rates of linear accelerator (LINAC)-based radiosurgery (X-knife) for indirect carotid-cavernous fistulas (CCFs).
...Materials and Methods: This retrospective study was performed at the Department of Radiosurgery, Chang Gung Memorial Hospital, Taiwan, and reviewed data from May 2006 to May 2018. Thirteen patients with CCF who were treated with stereotactic radiosurgery were included, and side, volume, pathological type, origin, location, postoperative regression, and recurrence rate were evaluated with postradiotherapy. Patients were either followed up with contrast magnetic resonance imaging or angiography. Radiosurgery was considered successful if the patients' clinical symptoms improved with radiological remission or if there was a reduction in CCF flow in angiography.
Results: Of the 11 patients, three (27.3%) received transarterial embolization (TAE) before radiosurgery. Successful radiological outcomes were seen in 10 (90.9%) patients, and the remaining one patient (9.1%) had stationary disease with no reduction in CCF flow. Ten patients (90.9%) had improved clinical symptoms; however, one patient (9.1%) was complicated with iatrogenic blindness after TAE treatment. No acute or subacute transient postradiation changes, optic nerve injuries, or brainstem radionecrosis were noted in any of the patients.
Conclusions: In this study, LINAC-based radiosurgery for CCF was found to be an effective, safe, and successful treatment alternative to TAE treatment in patients with indirect CCF. The risk of postradiotherapy complications was low, and obliteration and regression rates were high.
This study involved a simulation of transportation and basic life support on ambulances carrying coronavirus disease 2019 (COVID-19) patients, using a specially modified mannequin. The mannequin used ...can spew a fluorescent solution from its mouth to simulate the droplets or vomitus made by the patient and can be detected using ultraviolet light illumination. We determined that the most frequently contaminated areas of an ambulance in the driver's cabin are the left front door's outer handle, driver's handler, gear lever, and mat. The most frequently contaminated area in the rear patient's cabin is the rear door, rear door lining, and handle over the roof. The most frequently contaminated areas before the removal of personal protective equipment (PPE) are the lower chest to the belly area, bilateral hands, lower rim of the gown, and shoes. After the removal of PPE, traces of fluorescence were observed over the neck, hands, and legs. We therefore suggest taking a bath immediately after PPE removal.
We study the task of deterministically extracting randomness from sources containing computational entropy. The sources we consider have the form of a conditional distribution ( f ( X )| X ), for ...some function f and some distribution X , and we say that such a source has computational min-entropy k if any circuit of size 2 k can only predict f ( x ) correctly with probability at most 2 - k given input x sampled from X . We first show that it is impossible to have a seedless extractor to extract from one single source of this kind. Then we show that it becomes possible if we are allowed a seed which is weakly random (instead of perfectly random) but contains some statistical min-entropy, or even a seed which is not random at all but contains some computational min-entropy. This can be seen as a step toward extending the study of multisource extractors from the traditional, statistical setting to a computational setting. We reduce the task of constructing such extractors to a problem in computational learning theory: learning linear functions under arbitrary distribution with adversarial noise, and we provide a learning algorithm for this problem. In fact, this problem is a well-recognized one in computational learning theory and variants of this problem have been studied intensively before. Thus, in addition to its application to extractors, our learning algorithm also has independent interest of its own, and it can be considered as the main technical contribution of this paper.
We experimentally demonstrate a terahertz (THz) leaky mode directional coupler for future THz applications. The proposed directional coupler comprises two square pipe waveguides. The coupling ...efficiency is investigated for different frequencies, polarizations, and core sizes. Rectangular pipe-waveguide-based directional couplers and the issue of insertion loss are also discussed. It is found that the THz directional coupler works most efficiently in the minimal-attenuation wavelength regime.
We propose square and rectangular pipe waveguides for low-loss THz waveguiding and polarization control. Different from common circular-symmetric THz fibers and waveguides, the proposed rectangular ...pipe waveguides successfully remove the transmission degeneracy of two orthogonal polarizations and possess polarization sensitivity to the guided THz waves. By measuring the attenuation spectra, we find that the polarization sensitivity depends on the structure of the pipe waveguides. With butt coupling method, it is easy to combine circular pipe waveguides and the rectangular ones.
Background: The aging of society is a global trend, and care of older adults with dementia is an urgent challenge. As dementia progresses, patients exhibit negative emotions,memory disorders, sleep ...disorders, and agitated behavior. Agitated behavior is one of the most difficult problems for family caregivers and healthcare providers to handle when caring for older adults with dementia. Purpose: The aim of this study was to investigate the effectiveness of white noise in improving agitated behavior,mental status, and activities of daily living in older adults with dementia. Methods: An experimental research design was used to study elderly participants two times (pretest and posttest). Six dementia carecenters incentral andsouthernTaiwanwere targeted to recruit participants. There were 63 participants: 28 were in the experimental group, and 35 were in the comparison group. Experimental group participants received 20 minutes ofwhite noise consisting of ocean, rain, wind, and running water sounds between 4 and 5
In this paper, we consider the task of deterministically extracting randomness from sources consisting of a sequence of n independent symbols from {0,1} d . The only randomness guarantee on such a ...source is that the whole source has min-entropy k . We give an explicit deterministic extractor which extract Ω(log k -loglog(1/ ε)) bits with error ε , for any n , d , k ∈ \BBN and ε ∈ (0,1). For sources with a larger min-entropy, we can extract even more randomness. When k ≥ n 1/2+γ , for any constant γ ∈ (0,1/2), we can extract m = k - O ( d log(1/ ε)) bits with any error ε ≥ 2 -Ω( n γ ). When k ≥ log cn , for some constant c > 0, we can extract m = k -(1/ ε) O (1) bits with any error ε ≥ k -Ω(1) . Our results generalize those of Kamp and Zuckerman and Gabizon which only work for bit-fixing sources (with d =1 and each bit of the source being either fixed or perfectly random). Moreover, we show the existence of a nonexplicit deterministic extractor which can extract m = k - O (log(1/ ε)) bits whenever k =ω( d +log( n / ε)) . Finally, we show that even to extract from bit-fixing sources, any extractor, seeded or not, must suffer an entropy loss k - m =Ω(log(1/ ε)). This generalizes a lower bound of Radhakrishnan and Ta-Shma on extracting from general sources.
Background Immunotherapy has been widely used in the treatment of allergic diseases. We evaluated the clinical efficacy of specific immunotherapy with extracts of Dermatophagoides pteronyssinus ( Dp ...) and Dermatophagoides farinae ( Df ) in children with asthma. Methods All 40 children had moderate-to-severe asthma and positive allergen tests for Dp and Df . All required daily medication. They were randomly assigned to two groups: Half of them received immunotherapy with subcutaneous injections of Dp and Df extracts, while the other half were not given immunotherapy. Participants were followed up for more than 6 months. Results Children in both groups had apparent improvements in medication use and symptoms after 6 months. The mean medication scores declined from 3.6 ± 1.14 to 1.7 ± 0.66 in the immunotherapy group ( p < 0.01) and from 3.35 ± 0.87 to 2.4 ± 1.09 in the control group ( p < 0.01). There was a significant difference between the two groups (mean difference 0.95; p < 0.01). The symptom score improved in the immunotherapy group from 2.65 ± 0.98 to 1.20 ± 1.00 ( p < 0.01) and in the control group from 2.55 ± 0.99 to 1.40 ± 0.88 ( p < 0.01), with a significant difference between the two groups (mean difference 0.3; p < 0.01). The number of office visits in the immunotherapy group was greater than that of the controls, but the frequencies of emergency room visits and hospitalization decreased. Conclusion Our study showed that specific immunotherapy with Dp and Df was beneficial for asthmatic children.
On the Complexity of Hardness Amplification LU, Chi-Jen; TSAI, Shi-Chun; WU, Hsin-Lung
IEEE transactions on information theory,
10/2008, Volume:
54, Issue:
10
Journal Article
Peer reviewed
For deltaisin(0,1) and k , n isinN, we study the task of transforming a hard function f : {0,1} n rarr {0,1}, with which any small circuit disagrees on (1-delta)/2 fraction of the input, into a ...harder function f ', with which any small circuit disagrees on (1-delta k )/2 fraction of the input. First, we show that such hardness amplification, when carried out in some black-box way, must require a high complexity. In particular, it cannot be realized by a circuit of depth d and size 2 o ( k 1/d ) or by a nondeterministic circuit of size o ( k /log k ) (and arbitrary depth) for any deltaisin(0,1). This extends the result of Viola, which only works when (1-delta)/2 is small enough. Furthermore, we show that even without any restriction on the complexity of the amplification procedure, such a black-box hardness amplification must be inherently nonuniform in the following sense. To guarantee the hardness of the resulting function f ', even against uniform machines, one has to start with a function f , which is hard against nonuniform algorithms with Omega( k log(1/delta)) bits of advice. This extends the result of Trevisan and Vadhan, which only addresses the case with (1-delta)/2=2 - n . Finally, we derive similar lower bounds for any black-box construction of a pseudorandom generator (PRG) from a hard function. To prove our results, we link the task of hardness amplifications and PRG constructions, respectively, to some type of error-reduction codes, and then we establish lower bounds for such codes, which we hope could find interest in both coding theory and complexity theory.
We study the problem of deterministically extracting almost perfect random bits from multiple weakly random sources that are mutually independent. With two independent sources, we have an explicit ...extractor which can extract a number of random bits that matches the best construction currently known, via the generalized leftover hash lemma. We also extend our construction to extract randomness from more independent sources. One nice feature is that the extractor still works even with all but one source exposed. Finally, we apply our extractor for a cryptographic task in which a group of parties wants to agree on a secret key for group communication over an insecure channel, without using ideal local randomness.
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