Transcutaneous electrical nerve stimulation for cancer pain in adults.

Background Cancer-related pain is complex and multi-dimensional but the mainstay of cancer pain management has predominately used a biomedical approach. There is a need for non-pharmacological and innovative approaches. Transcutaneous Electric Nerve Stimulation (TENS) may have a role for a significant number of patients but the effectiveness of TENS is currently unknown. Objectives The aim of this systematic review was to determine the effectiveness of TENS for cancer-related pain in adults. Search strategy We searched The Cochrane Library, MEDLINE, EMBASE, CINAHL, PsychINFO, AMED and PEDRO databases (11/04/08). Selection criteria Only randomised controlled trials (RCTS) investigating the use of TENS for the management of cancer-related pain in adults were included. Data collection and analysis The search strategy identified 37 possible published studies which were divided between two pairs of review authors that decided on study selection. A study eligibility form was used to screen each abstract and where study eligibility could not be determined from the abstract, the full paper was obtained and assessed by one pair of review authors. A standardised data extraction sheet was used to collect information on the studies and the quality of the studies was assessed independently by two review authors using the validated five-point Oxford Quality Scale. Final scores were discussed and agreed between all four review authors. The small sample sizes and differences in patient study populations of the two included studies prevented meta-analysis. Main results Only two RCTs met the eligibility criteria (64 participants). These studies were heterogenous with respect to study population, sample size, study design, methodological quality, mode of TENS, treatment duration, method of administration and outcome measures used. In one RCT, there were no significant differences between TENS and placebo in women with chronic pain secondary to breast cancer treatment. In the other RCT, there were no significant differences between acupuncture-type TENS and sham in palliative care patients; this study was underpowered. Authors' conclusions The results of this systematic review are inconclusive due to a lack of suitable RCTs. Large multi-centre RCTs are required to assess the value of TENS in the management of cancer-related pain in adults

Quantum secret sharing

Secret sharing is a procedure for splitting a message into several parts so that no subset of parts is sufficient to read the message, but the entire set is. We show how this procedure can be implemented using GHZ states. In the quantum case the presence of an eavesdropper will introduce errors so that his presence can be detected. We also show how GHZ states can be used to split quantum information into two parts so that both parts are necessary to reconstruct the original qubit.Comment: 6 pages, revtex, revised version, to appear in Phys. Rev.

Extended γ‐ray emission in solar flares

During the solar flare events on 11 and 15 June 1991, COMPTEL measured extended emission in the neutron capture line for about 5 hours after the impulsive phase. The time profiles can be described by a double exponential decay with decay constants on the order of 10 min for the fast and 200 min for the slow component. Within the statistical uncertainty both flares show the same long‐term behaviour. The spectrum during the extended phase is significantly harder than during the impulsive phase and pions are not produced in significant numbers before the beginning of the extended emission. Our results with the measurements of others allow us to rule out long‐term trapping of particles in non‐turbulent loops to explain the extended emission of these two flares and our data favour models based on continued acceleration

COMPTEL observations of the Virgo blazars 3C 273 and 3C 279

We report the main MeV properties (detections, light curves, spectra) of the Virgo blazars 3C 273 and 3C 279 which were derived from a consistent analysis of all COMPTEL Virgo observations between 1991 and 1997

COMPTEL observations of the blazars 3C 454.3 and CTA 102

We have analyzed the two blazars of 3C 454.3 and CTA 102 using all available COMPTEL data from 1991 to 1999. In the 10–30 MeV band, emission from the general direction of the sources is found at the 4σ-level, being consistent with contributions from both sources. Below 10 MeV only 3C 454.3 is significantly detected, with the strongest evidence (5.6 σ) in the 3–10 MeV band. Significant flux variability is not observed for both sources, while a low emission is seen most of the years in the 3–10 MeV light curve for 3C 454.3. Its time-averaged MeV spectrum suggests a power maximum between 3 to 10 MeV

Quantum cryptography with squeezed states

A quantum key distribution scheme based on the use of displaced squeezed vacuum states is presented. The states are squeezed in one of two field quadrature components, and the value of the squeezed component is used to encode a character from an alphabet. The uncertainty relation between quadrature components prevents an eavesdropper from determining both with enough precision to determine the character being sent. Losses degrade the performance of this scheme, but it is possible to use phase-sensitive amplifiers to boost the signal and partially compensate for their effect.Comment: 15 pages, no figure

Cost-effectiveness analysis of the management of distal ureteral stones in children

Objective To determine the most cost-effective approach to the management of distal ureteral stones in children given the potential for recurrent renal colic during a trial of passage versus potential stent discomfort and complications of ureteroscopy. Methods We developed a decision tree to project costs and clinical outcomes associated with observation, medical explusive therapy (MET), and ureteroscopy for the management of an index patient with a 4mm distal ureteral stone. We determined which strategy would be least costly and offer the most pain-free days within 30 days of diagnosis. We performed a one-way sensitivity analysis on the probability of successful stone passage with MET. We obtained probabilities from the literature and costs from the 2016 Pediatric Health Information System Database. Results Ureteroscopywas the costliest strategy but maximized the number of pain-free days within 30 days of diagnosis ($5,282/29 pain-free days). MET was less costly than ureteroscopybut also less effective ($615/21.8 pain-free days). Observation cost more than MET and was also less effective ($2,139/15.5 pain-free days). The one-way sensitivity analysis on the probability of successful stone passage with MET demonstrated that ureteroscopyalways has the highest net monetary benefits value and is therefore the recommended strategy given a fixed WTP. Discussion Using a rigorous decision-science approach, we found that ureteroscopy is the recommended strategy in children with small distal ureteral stones. Although it cost more than MET, it resulted in more pain-free days in the first 30 days following diagnosis given the faster resolution of the stone episode

The quantum dynamic capacity formula of a quantum channel

The dynamic capacity theorem characterizes the reliable communication rates of a quantum channel when combined with the noiseless resources of classical communication, quantum communication, and entanglement. In prior work, we proved the converse part of this theorem by making contact with many previous results in the quantum Shannon theory literature. In this work, we prove the theorem with an "ab initio" approach, using only the most basic tools in the quantum information theorist's toolkit: the Alicki-Fannes' inequality, the chain rule for quantum mutual information, elementary properties of quantum entropy, and the quantum data processing inequality. The result is a simplified proof of the theorem that should be more accessible to those unfamiliar with the quantum Shannon theory literature. We also demonstrate that the "quantum dynamic capacity formula" characterizes the Pareto optimal trade-off surface for the full dynamic capacity region. Additivity of this formula simplifies the computation of the trade-off surface, and we prove that its additivity holds for the quantum Hadamard channels and the quantum erasure channel. We then determine exact expressions for and plot the dynamic capacity region of the quantum dephasing channel, an example from the Hadamard class, and the quantum erasure channel.Comment: 24 pages, 3 figures; v2 has improved structure and minor corrections; v3 has correction regarding the optimizatio

Activation in the COMPTEL double-scattering gamma-ray telescope

Abstract-The COMPTEL gamma-ray telescope has been operating in low Earth orbit for six years, since the launch of the Compton Gamma-Ray Observatory in April 1991. Comparisons of data for different orbits and epochs show evidence of activation on time scales from minutes (27Mg, q,2=9.5 min) to years C2Na, q&.58 yr). The activation is correlated with both the orbital altitude and solar cosmic-ray modulation. Because it requires coincident measurements in two different detectors, COMPTEL is most susceptible to instrumental background events in which two or more photons are produced simultaneously

COMPTEL 1.8 MeV all sky survey: The Cygnus region

We present an updated version of COMPTEL’s 1.809 MeV sky survey. Based on eight years of observations we compare results from different imaging techniques using background from adjacent energy bands. We confirm the previously reported characteristics of the galactic 1.809 MeV emission, specifically an extended galactic ridge emission, mainly concentrated towards the inner galaxy, a peculiar emission feature in the Cygnus region, and a low-intensity ridge extending towards Carina and Vela. Because this gamma ray line is due to the decay of radioactive 26Al, predominantly synthesized in massive stars, one anticipates flux enhancements aligned with regions of recent star formation. This is born out by the observations. In particular the Cygnus feature, first presented in 1996 based on three years of COMPTEL data, is confirmed. Based on the stellar population we distinguish three prominent areas in this region, for which we separately derive fluxes, and discuss interpretations