465 research outputs found
Postprocessing for quantum random number generators: entropy evaluation and randomness extraction
Quantum random-number generators (QRNGs) can offer a means to generate
information-theoretically provable random numbers, in principle. In practice,
unfortunately, the quantum randomness is inevitably mixed with classical
randomness due to classical noises. To distill this quantum randomness, one
needs to quantify the randomness of the source and apply a randomness
extractor. Here, we propose a generic framework for evaluating quantum
randomness of real-life QRNGs by min-entropy, and apply it to two different
existing quantum random-number systems in the literature. Moreover, we provide
a guideline of QRNG data postprocessing for which we implement two
information-theoretically provable randomness extractors: Toeplitz-hashing
extractor and Trevisan's extractor.Comment: 13 pages, 2 figure
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Urinary incontinence related to perineal muscle strength in the first trimester of pregnancy: cross-sectional study
Objective To analyze pelvic floor muscle strength (PFMS), urinary continence and quality of life related to urinary incontinence (UI) of women in the first trimester of pregnancy. Method Cross-sectional study with a sample of 500 women who started prenatal care in a complementary healthcare facility in Guarulhos, state of São Paulo, from 2012 and 2013. Pelvic floor muscle strength was evaluated through perineometry. The pregnant women who presented UI answered the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF). Results It was found that maternal age (OR=1.06; CI95% 1.02-1.11) and prior UI (OR=15.12; 95%CI 8.19-27.92) are the variables that, in tandem, best explain the occurrence of UI at the beginning of pregnancy. The mean score on the ICIQ-SF was 8.2 (SD=3.9), considered a moderate impact on quality of life. Conclusion Older pregnant women with prior UI are more likely to have UI in the first trimester of pregnancy.
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Biochemical alterations in duckweed and algae induced by carrier solvents: Selection of an appropriate solvent in toxicity testing
Carrier solvents are often used in aquatic toxicity testing for test chemicals with hydrophobic properties. However, the knowledge of solvent effects on test organisms remains limited. This study aimed to understand biochemical effects of the four common solvents ((methanol, ethanol, acetone and dimethylsulfoxide (DMSO)) on two test species Lemna minor and Raphidocelis subcapitata by applying Fourier transform infrared spectroscopy (FTIR) coupled with multivariate analysis in order to select appropriate solvents in the toxicity testing. The results showed biochemical variations associated with solvent treatments at different doses on test species. From the obtained infrared spectra, the structures of lipid membrane and protein phosphorylation in the test species were found sensitive to the solvents. Methanol and ethanol mainly affected the protein secondary structure, while acetone and DMSO primarily induced the alterations of carbohydrate and proteins in the test species. The FTIR results demonstrated that methanol and ethanol showed higher biochemical alterations in the test species than acetone and DMSO, especially at the high doses (0.1% and 1% v/v). Based on the growth inhibition and FTIR spectroscopy, acetone and DMSO can be used as carrier solvent in the toxicity testing when their doses are lower than 0.1% v/v. This article is protected by copyright. All rights reserve
Nuclear EMC Effect in a Statistical Model
A simple statistical model in terms of light-front kinematic variables is
used to explain the nuclear EMC effect in the range , which
was constructed by us previously to calculate the parton distribution functions
(PDFs) of the nucleon. Here, we treat the temperature as a parameter of the
atomic number , and get reasonable results in agreement with the
experimental data. Our results show that the larger , the lower thus the
bigger volume , and these features are consistent with other models.
Moreover, we give the predictions of the quark distribution ratios,
\emph{i.e.}, , , and , and also the gluon ratio for iron as an example. The
predictions are different from those by other models, thus experiments aiming
at measuring the parton ratios of antiquarks, strange quarks, and gluons can
provide a discrimination of different models.Comment: 26 latex pages, 3 figure
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Women’s pelvic floor muscle strength and urinary and anal incontinence after childbirth: a cross-sectional study
Abstract OBJECTIVE To analyse pelvic floor muscle strength (PFMS) and urinary and anal incontinence (UI and AI) in the postpartum period. METHOD Cross-sectional study carried out with women in their first seven months after child birth. Data were collected through interviews, perineometry (Peritron™), and the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF). RESULTS 128 women participated in the study. The PFMS mean was 33.1 (SD=16.0) cmH2O and the prevalence of UI and AI was 7.8% and 5.5%, respectively. In the multiple analyses, the variables associated with PFMS were type of birth and cohabitation with a partner. Newborn’s weight, previous pregnancy, UI during pregnancy, and sexual activity showed an association with UI after child birth. Only AI prior to pregnancy was associated with AI after childbirth. CONCLUSION Vaginal birth predisposes to the reduction of PFMS, and caesarean section had a protective effect to its reduction. The occurrence of UI during pregnancy is a predictor of UI after childbirth, and women with previous pregnancies and newborns with higher weights are more likely to have UI after childbirth.AI prior to pregnancy is the only risk factor for its occurrence after childbirth. Associations between PFMS and cohabitation with a partner, and between UI and sexual activity do not make possible to conclude that these variables are directly associated
Surface-enhanced Raman spectroscopy of the endothelial cell membrane
We applied surface-enhanced Raman spectroscopy (SERS) to cationic gold-labeled endothelial cells to derive SERS-enhanced spectra of the bimolecular makeup of the plasma membrane. A two-step protocol with cationic charged gold nanoparticles followed by silver-intensification to generate silver nanoparticles on the cell surface was employed. This protocol of post-labelling silver-intensification facilitates the collection of SERS-enhanced spectra from the cell membrane without contribution from conjugated antibodies or other molecules. This approach generated a 100-fold SERS-enhancement of the spectral signal. The SERS spectra exhibited many vibrational peaks that can be assigned to components of the cell membrane. We were able to carry out spectral mapping using some of the enhanced wavenumbers. Significantly, the spectral maps suggest the distribution of some membrane components are was not evenly distributed over the cells plasma membrane. These results provide some possible evidence for the existence of lipid rafts in the plasma membrane and show that SERS has great potential for the study and characterization of cell surfaces
Deletion of scavenger receptor A protects mice from progressive nephropathy independent of lipid control during diet-induced hyperlipidemia
Scavenger receptor A (SR-A) is a key transmembrane receptor in the endocytosis of lipids and contributes to the pathogenesis of atherosclerosis. To assess its role in hyperlipidemic chronic kidney disease, wild-type and SR-A-deficient (knockout) mice underwent uninephrectomy followed by either normal or high-fat diet. After 16 weeks of diet intervention, hyperlipidemic wild-type mice presented characteristic features of progressive nephropathy: albuminuria, renal fibrosis, and overexpression of transforming growth factor (TGF)-β1/Smad. These changes were markedly diminished in hyperlipidemic knockout mice and attributed to reduced renal lipid retention, oxidative stress, and CD11c+ cell infiltration. In vitro, overexpression of SR-A augmented monocyte chemoattractant protein-1 release and TGF-β1/Smad activation in HK-2 cells exposed to oxidized low-density lipoprotein. SR-A knockdown prevented lipid-induced cell injury. Moreover, wild-type to knockout bone marrow transplantation resulted in renal fibrosis in uninephrectomized mice following 16 weeks of the high-fat diet. In contrast, knockout to wild-type bone marrow transplantation led to markedly reduced albuminuria, CD11c+ cell infiltration, and renal fibrosis compared to wild-type to SR-A knockout or wild-type to wild-type bone marrow transplanted mice, without difference in plasma lipid levels. Thus, SR-A on circulating leukocytes rather than resident renal cells predominantly mediates lipid-induced kidney injury
Quantum metric nonlinear Hall effect in a topological antiferromagnetic heterostructure
Quantum geometry - the geometry of electron Bloch wavefunctions - is central
to modern condensed matter physics. Due to the quantum nature, quantum geometry
has two parts, the real part quantum metric and the imaginary part Berry
curvature. The studies of Berry curvature have led to countless breakthroughs,
ranging from the quantum Hall effect in 2DEGs to the anomalous Hall effect
(AHE) in ferromagnets. However, in contrast to Berry curvature, the quantum
metric has rarely been explored. Here, we report a new nonlinear Hall effect
induced by quantum metric by interfacing even-layered MnBi2Te4 (a PT-symmetric
antiferromagnet (AFM)) with black phosphorus. This novel nonlinear Hall effect
switches direction upon reversing the AFM spins and exhibits distinct scaling
that suggests a non-dissipative nature. Like the AHE brought Berry curvature
under the spotlight, our results open the door to discovering quantum metric
responses. Moreover, we demonstrate that the AFM can harvest wireless
electromagnetic energy via the new nonlinear Hall effect, therefore enabling
intriguing applications that bridges nonlinear electronics with AFM
spintronics.Comment: 19 pages, 4 figures and a Supplementary Materials with 66 pages, 4
figures and 3 tables. Originally submitted to Science on Oct. 5, 202
Hyperglycemia and prostate cancer recurrence in men treated for localized prostate cancer.
Background:Obesity is consistently linked with prostate cancer (PCa) recurrence and mortality, though the mechanism is unknown. Impaired glucose regulation, which is common among obese individuals, has been hypothesized as a potential mechanism for PCa tumor growth. In this study, we explore the relationship between serum glucose at time of treatment and risk of PCa recurrence following initial therapy.Methods:The study group comprised 1734 men treated with radical prostatectomy (RP) or radiation therapy (RT) for localized PCa between 2001-2010. Serum glucose levels closest to date of diagnosis were determined. PCa recurrence was determined based on PSA progression (nadir PSA+2 for RT; PSA0.2 for RP) or secondary therapy. Multivariate Cox regression was performed to determine whether glucose level was associated with biochemical recurrence after adjusting for age, race, body mass index, comorbidity, diagnosis of diabetes, Gleason Sum, PSA, treatment and treatment year.Results:Recurrence was identified in 16% of men over a mean follow-up period of 41 months (range 1-121 months). Those with elevated glucose (100 mg/dl) had a 50% increased risk of recurrence (HR 1.5, 95% CI: 1.1-2.0) compared with those with a normal glucose level (<100 mg/dl). This effect was seen in both those undergoing RP (HR 1.9, 95% CI: 1.0-3.6) and those treated with RT (HR 1.4, 95% CI: 1.0-2.0).Conclusions:Glucose levels at the time of PCa diagnosis are an independent predictor of PCa recurrence for men undergoing treatment for localized disease
Treatment of recurrent malignant gliomas with fotemustine monotherapy: impact of dose and correlation with MGMT promoter methylation
<p>Abstract</p> <p>Background</p> <p>In recurrent malignant gliomas (MGs), a high rate of haematological toxicity is observed with the use of fotemustine at the conventional schedule (100 mg/m<sup>2 </sup>weekly for 3 consecutive weeks followed by triweekly administration after a 5-week rest period). Also, the impact of O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status on fotemustine activity has never been explored in the clinical setting.</p> <p>Methods</p> <p>40 patients with recurrent pretreated MG were identified as being treated with fotemustine at doses ranging from 65 mg/m<sup>2 </sup>to 100 mg/m<sup>2</sup>. Patients were classified into 3 groups according to the dose of fotemustine received, from the lowest dosage received in group A, to the highest in group C. Analysis of MGMT promoter methylation in tumor tissue was successfully performed in 19 patients.</p> <p>Results</p> <p>Overall, 20% of patients responded to treatment, for a disease control rate (DCR, responses plus stabilizations) of 47.5%. Groups A and B experienced a response rate of 40% and 26.5% respectively, while the corresponding value for group C was 10%. Out of 19 patients, MGMT promoter was found methylated in 12 cases among which a DCR of 66.5% was observed. All 7 patients with unmethylated MGMT promoter were progressive to fotemustine.</p> <p>Conclusion</p> <p>Low-dose fotemustine at 65–75 mg/m<sup>2 </sup>(induction phase) followed by 75–85 mg/m<sup>2 </sup>(maintenance phase) has an activity comparable to that of the conventional schedule. By determination of the MGMT promoter methylation status patients might be identified who are more likely to benefit from fotemustine chemotherapy.</p
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