665 research outputs found
Characterization of metabolically healthy obese people and metabolically unhealthy normal-weight people in a general population cohort of the ABCD Study
There is actually no consensus about the possibility that in some instances, obesity may be a benign metabolically healthy (MH) condition as opposed to a normal-weight but metabolically unhealthy (MUH) state. The aim of this study was to characterize MH condition and to investigate possible associations with metabolic and cardiovascular complications. One thousand nineteen people (range of age 18-90 years) of the cohort of the ABCD-2 study were investigated. Participants were classified as normal weight (BMI < 24.9 kg/m2) or overweight-obese (BMI \ue2\u89\ua525 kg/m2); they were also classified as MH in the presence of 0-1 among the following conditions: (a) prediabetes/type 2 diabetes, (b) hypertension, (c) hypertriglyceridemia or low HDL cholesterolemia, and (d) hypercholesterolemia. MUH condition was diagnosed if \ue2\u89\ua52 of the conditions listed were found. The prevalence of overweight/obese people was 71.1%, of whom 27.4% were found to be MH. In addition, 36.7% of the normal-weight participants were MUH. HOMA-IR, high sensitivity C-reactive protein, and the carotid intima-media thickness were significantly different in the 4 subgroups (P < 0.001), with higher values observed in the MUH normal-weight and obese groups. In conclusion, this study highlights the importance of identifying a MH condition in normal-weight and in obese people in order to offer better treatment
Superbroadcasting of continuous variables mixed states
We consider the problem of broadcasting quantum information encoded in the
average value of the field from N to M>N copies of mixed states of radiation
modes. We derive the broadcasting map that preserves the complex amplitude,
while optimally reducing the noise in conjugate quadratures. We find that from
two input copies broadcasting is feasible, with the possibility of simultaneous
purification (superbroadcasting). We prove similar results for purification
(M<=N) and for phase-conjugate broadcasting.Comment: 11 pages, 1 figure, revtex4 style, revised versio
Electron interference and entanglement in coupled 1D systems with noise
We estimate the role of noise in the formation of entanglement and in the
appearance of single- and two-electron interference in systems of coupled
one-dimensional channels semiconductors. Two cases are considered: a
single-particle interferometer and a two-particle interferometer exploiting
Coulomb interaction. In both of them, environmental noise yields a
randomization of the carrier phases. Our results assess how that the
complementarity relation linking single-particle behavior to nonlocal
quantities, such as entanglement and environment-induced decoherence, acts in
electron interferometry. We show that, in a experimental implementation of the
setups examined, one- and two-electron detection probability at the output
drains can be used to evaluate the decoherence phenomena and the degree of
entanglement.Comment: 12 pages, 6 figures. v2: added some references and corrected tex
Argon plasma coagulation in the treatment of post-radiotherapy rectal bleeding
Introduction: Chronic radiation proctitis is often associated to radiotherapy for treatment of pelvic cancer. The most common side effect of this pathological condition is rectal bleeding but despite the great number of clinical approaches and techniques that have been employed no consensus for the management of it is available. Although prospective randomized trials about hemorrhagic radiation proctitis are still lacking, endoscopic approach delivering an Argon Plasma Coagulation (APC) seems to be a successful and available option. Patients and Methods: Sixteen patients suffering from post-radiotherapy rectal
bleeding were followed. In the nine cases
presenting a rectum ulcerative colitis (RUC) like endoscopic picture a 5-ASA therapeutic
approach was chosen initially, followed by an APC treatment of areas of telangectasias. The other cases, presenting only areas of telangectasias, were treated only with APC. Results: 5-ASA therapy led to an improvement of inflammation state related to RUC but recurrence of rectal bleeding caused by telangectasias was observed. In these cases an additional APC treatment gave a total remission of the problem. Also in the other cases, presenting only areas of telangectasias, a remission of rectal bleeding was achieved through APC application. Conclusions: In the cases of radiation proctitis characterized by a severe compromission of rectal mucosa integrity an anti-inflammatory pharmacological therapy is necessary but not sufficient to abrogate
rectal bleeding which is often caused by the
presence of areas of telangectasias. In these cases a remission of the problem could be achieved through a combination of anti-inflammatory therapy (5-ASA) and APC
Clean Positive Operator Valued Measures
In quantum mechanics the statistics of the outcomes of a measuring apparatus
is described by a positive operator valued measure (POVM). A quantum channel
transforms POVM's into POVM's, generally irreversibly, thus loosing some of the
information retrieved from the measurement. This poses the problem of which
POVM's are "undisturbed", namely they are not irreversibly connected to another
POVM. We will call such POVM clean. In a sense, the clean POVM's would be
"perfect", since they would not have any additional "extrinsical" noise. Quite
unexpectedly, it turns out that such cleanness property is largely unrelated to
the convex structure of POVM's, and there are clean POVM's that are not
extremal and vice-versa. In this paper we solve the cleannes classification
problem for number n of outcomes n<=d (d dimension of the Hilbert space), and
we provide a a set of either necessary or sufficient conditions for n>d, along
with an iff condition for the case of informationally complete POVM's for
n=d^2.Comment: Minor changes. amsart 21 pages. Accepted for publication on J. Math.
Phy
The modern tools of quantum mechanics (A tutorial on quantum states, measurements, and operations)
This tutorial is devoted to review the modern tools of quantum mechanics,
which are suitable to describe states, measurements, and operations of
realistic, not isolated, systems in interaction with their environment, and
with any kind of measuring and processing devices. We underline the central
role of the Born rule and and illustrate how the notion of density operator
naturally emerges, together the concept of purification of a mixed state. In
reexamining the postulates of standard quantum measurement theory, we
investigate how they may formally generalized, going beyond the description in
terms of selfadjoint operators and projective measurements, and how this leads
to the introduction of generalized measurements, probability operator-valued
measures (POVM) and detection operators. We then state and prove the Naimark
theorem, which elucidates the connections between generalized and standard
measurements and illustrates how a generalized measurement may be physically
implemented. The "impossibility" of a joint measurement of two non commuting
observables is revisited and its canonical implementations as a generalized
measurement is described in some details. Finally, we address the basic
properties, usually captured by the request of unitarity, that a map
transforming quantum states into quantum states should satisfy to be physically
admissible, and introduce the notion of complete positivity (CP). We then state
and prove the Stinespring/Kraus-Choi-Sudarshan dilation theorem and elucidate
the connections between the CP-maps description of quantum operations, together
with their operator-sum representation, and the customary unitary description
of quantum evolution. We also address transposition as an example of positive
map which is not completely positive, and provide some examples of generalized
measurements and quantum operations.Comment: Tutorial. 26 pages, 1 figure. Published in a special issue of EPJ -
ST devoted to the memory of Federico Casagrand
Laser Pressure Catapulting (LPC): Optimization LPC-System and Genotyping of Colorectal Carcinomas
Genotype analysis is becoming more and more useful in clinical practice, since specific mutations in tumors often correlate with prognosis and/or therapeutic response. Unfortunately, current molecular analytical techniques often require time-consuming and costly steps of analysis, thus making their routine clinical use difficult. Moreover, one of the most difficult problems arising during tumor research is that of their cell heterogeneity, which depends on their clear molecular heterogeneity. SSCP analysis discriminates by means of aberrant electrophoresis migration bands, mutated alleles which may represent as little as 15-20% of their total number. Nevertheless, in order to identify by sequencing the type of alteration revealed by this technique, only the mutated allele must be isolated. The advent of laser microdissection is a procedure which easily solves these problems of accuracy, costs, and time. The aims of this study were to perfect the system of laser pressure catapulting (LPC) laser microdissection for the assessment of the mutational status of p53 and k-ras genes in a consecutive series of 67 patients with colorectal carcinomas (CRC), in order to compare this technique with that involving hand-dissection and to demonstrate that since the LPC system guarantees more accurate biomolecular analyses, it should become part of clinical routine in this field. The LPC-system was perfected with the use of mineral oil and the LPC-membrane. To compare the techniques of hand- and LPC-microdissection, alcohol-fixed, paraffin-embedded tissue from 67 cases of CRC were both hand- and laser-microdissected. In either case, dissected samples were analyzed by SSCP/sequencing and direct sequencing for k-ras and p53 gene mutations. LPC-microdissection made it possible to pick up mutations by direct sequencing or SSCP/sequencing, whereas hand-microdissection mutations were identified only by means of SSCP followed by sequencing; direct sequencing did not reveal any mutation. In the 67 patients examined by either method, 36% (24/67) showed p53 mutations, 32 of which identified. Seventy-eight percent (25/32) were found in the conserved areas of the gene, while 12% (4/32) were in the L2 loop, 50% (16/32) were in the L3 loop, and 12% (4/32) in the LSH motif of the protein. Moreover, of the 67 cases examined, 40% (27/67) showed mutations in k-ras, with a total of 29 mutations identified. Of these, 14 (48%) were found in codon 12 and 15 (52%) in codon 13. The modifications which we brought to the LPC system led to a vast improvement of the technique, making it an ideal substitution for hand-microdissection and guaranteeing a considerable number of advantages regarding facility, accuracy, time, and cost. Furthermore, the data obtained from the mutational analyses performed confirm that the LPC system is more efficient and rapid than hand-microdissection for acquiring useful information regarding molecular profile and can therefore be used with success in clinical routine
Generalised quantum weakest preconditions
Generalisation of the quantum weakest precondition result of D'Hondt and
Panangaden is presented. In particular the most general notion of quantum
predicate as positive operator valued measure (POVM) is introduced. The
previously known quantum weakest precondition result has been extended to cover
the case of POVM playing the role of a quantum predicate. Additionally, our
result is valid in infinite dimension case and also holds for a quantum
programs defined as a positive but not necessary completely positive
transformations of a quantum states.Comment: 7 pages, no figures, added references, changed conten
Local channels preserving maximal entanglement or Schmidt number
Maximal entanglement and Schmidt number play an important role in various
quantum information tasks. In this paper, it is shown that a local channel
preserves maximal entanglement state(MES) or preserves pure states with Schmidt
number ( is a fixed integer) if and only if it is a local unitary
operation.Comment: 10 page
A novel crosstalk between CCAR2 and AKT pathway in the regulation of cancer cell proliferation
Human CCAR2 has recently emerged as having a pivotal role in the DNA damage response, promoting apoptosis and repair of heterochromatic DNA breaks. However, less is known about the function of CCAR2 in tumor formation and cancer progression. Here, we demonstrate, for the first time, that CCAR2 loss inhibits the proliferation of cancer cells, but preserves the growth of normal cells. Investigating the mechanisms responsible for this differential effect, we found that CCAR2 depletion specifically impairs the activation of AKT pathway in cancer cells, but not in normal cells, by reducing AKT phosphorylation on Ser473. This effect is achieved through the transcriptional upregulation of TRB3 gene and accumulation of TRB3 protein, which then binds to and inhibits the phosphorylation and activation of AKT. The defective activation of AKT finally results in reduced GSK3\u3b2 phosphorylation, prevention of G1/S transition and inhibition of cancer cell growth. These results establish an important role for CCAR2 in cancer cells proliferation and could shed new light on novel therapeutic strategies against cancer, devoid of detrimental side effects
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