954 research outputs found
An experimental proposal to study collapse of the wave function in travelling-wave parametric amplifiers
The read-out of a microwave qubit state occurs using an amplification chain
that enlarges the quantum state to a signal detectable with a classical
measurement apparatus. However, at what point in this process did we really
`measure' the quantum state? In order to investigate whether the `measurement'
takes place in the amplification chain, we propose to construct a microwave
interferometer that has a parametric amplifier added to each of its arms.
Feeding the interferometer with single photons, the visibility depends on the
gain of the amplifiers and whether a measurement collapse has taken place
during the amplification process. We calculate the interference visibility as
given by standard quantum mechanics as a function of gain, insertion loss and
temperature and find a magnitude of in the limit of large gain without
taking into account losses. This number reduces to in case the insertion
loss of the amplifiers is dB at a temperature of mK. We show that if
the wave function collapses within the interferometer, we will measure a
reduced visibility compared to the prediction from standard quantum mechanics
once this collapse process sets in.Comment: 21 pages and 23 figures (including appendices and subfigures). v4:
Abstract and introduction rewritten and note on stochasticity of quantum
state collapse added to section 6. v5: no content changes w.r.t. v
122Outcome of unrelated umbilical cord-blood transplants (UCBT) in pediatric patients: Experience of one center
This item contains two issues of the Take One newsletter: September 8, and 22, 1977.Take One was published every two weeks and focused on short news items and announcements "for the people of University Hospital.
Аліментні обов'язки інших членів сім'ї та родичів
Виявлено проблеми у врегулюванні аліментних обов’язків інших членів сім’ї та родичів, вироблено рекомендації щодо їх вирішення. Проаналізовано специфіку правового
регулювання аліментних зобов’язань зазначених суб’єктів, сімейне законодавство та
міжнародний досвід.
Ключові слова: аліментні обов’язки, правове регулювання, сімейне законодавство.Выявлены проблемы в урегулировании алиментных обязанностей других членов семьи и родственников, выработаны рекомендации по их решению. Проанализирована
специфика правового регулирования алиментных обязательств указанных субъектов,
семейное законодательство и международный опыт.
Ключевые слова: алиментные обязанности, правовое регулирование, семейное законодавствоThis article is dedicated to identifying problems in the regulation of the alimentary obligations of other family members and relatives, and to making recommendations and proposing solutions. Studing the specificity of the legal regulation of alimentary obligations of these
entities, analysing the current family law and international experience are very important.
Key words: alimentary obligations, legal regulation, family law
Urocortin 2 Infusion in Healthy Humans Hemodynamic, Neurohormonal, and Renal Responses
ObjectivesWe sought to examine the effects of urocortin (UCN) 2 infusion on hemodynamic status, cardiovascular hormones, and renal function in healthy humans.BackgroundUrocortin 2 is a vasoactive and cardioprotective peptide belonging to the corticotrophin-releasing factor peptide family. Recent reports indicate the urocortins exert important effects beyond the hypothalamo-pituitary-adrenal axis upon cardiovascular and vasohumoral function in health and cardiac disease.MethodsWe studied 8 healthy unmedicated men on 3 separate occasions 2 to 5 weeks apart. Subjects received placebo, 25-μg low-dose (LD), and 100-μg high-dose (HD) of UCN 2 intravenously over the course of 1 h in a single-blind, placebo-controlled, dose-escalation design. Noninvasive hemodynamic indexes, neurohormones, and renal function were measured.ResultsThe administration of UCN 2 dose-dependently increased cardiac output (mean peak increments ± SEM) (placebo 0.5 ± 0.2 l/min; LD 2.1 ± 0.6 l/min; HD 5.0 ± 0.8 l/min; p < 0.001), heart rate (placebo 3.3 ± 1.0 beats/min; LD 8.8 ± 1.8 beats/min; HD 17.8 ± 2.1 beats/min; p < 0.001), and left ventricular ejection fraction (placebo 0.6 ± 1.4%; LD 6.6 ± 1.5%; HD 14.1 ± 0.8%; p < 0.001) while decreasing systemic vascular resistance (placebo −128 ± 50 dynes·s/cm5; LD −407 ± 49 dynes·s/cm5; HD −774 ± 133 dynes·s/cm5; p < 0.001). Activation of plasma renin activity (p = 0.002), angiotensin II (p = 0.001), and norepinephrine (p < 0.001) occurred only with the higher 100-μg dose. Subtle decreases in urine volume (p = 0.012) and natriuresis (p = 0.001) were observed.ConclusionsBrief intravenous infusions of UCN 2 in healthy humans induced pronounced dose-related increases in cardiac output, heart rate, and left ventricular ejection fraction while decreasing systemic vascular resistance. Subtle renal effects and activation of plasma renin, angiotensin II, and norepinephrine (at high-dose only) were observed. These findings warrant further investigation of the role of UCN 2 in circulatory regulation and its potential therapeutic application in heart disease
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Optical pump-probe processes in Nd 3+ doped KPb2Br5, RbPb2Br5, and KPb2CI5
Recently, laser activity has been achieved in the low phonon energy, moisture-resistant bromide host crystals, neodymium-doped potassium lead bromide (Nd{sup 3+}:KPb{sub 2}Br{sub 5}) and rubidium lead bromide (Nd{sup 3+}:RbPb{sub 2}Br{sub 5}). Laser activity at 1.07 {micro}m was observed for both crystalline materials. Laser operation at the new wavelengths 1.18 {micro}m and 0.97 {micro}m resulting from the {sup 4}F{sub 5/2}+{sup 2}H{sub 9/2} {yields} {sup 4}I{sub J} transitions (J=13/2 and 11/2) in Nd:RPB was achieved for the first time in a solid state laser material. In this paper we present cw pump-probe spectra in order to discuss excited state absorption, reabsorption processes due to the long lived lower laser levels as well as possible depopulation mechanisms feasible for more efficient laser operation in these crystals. The bromides will be compared with potassium lead chloride (Nd{sup 3+}:KPb{sub 2}Cl{sub 5})
Visualization of HIV-1 interactions with penile and foreskin epithelia: clues for female-to-male HIV transmission
To gain insight into female-to-male HIV sexual transmission and how male circumcision protects against this mode of transmission, we visualized HIV-1 interactions with foreskin and penile tissues in ex vivo tissue culture and in vivo rhesus macaque models utilizing epifluorescent microscopy. 12 foreskin and 14 cadaveric penile specimens were cultured with R5-tropic photoactivatable (PA)-GFP HIV-1 for 4 or 24 hours. Tissue cryosections were immunofluorescently imaged for epithelial and immune cell markers. Images were analyzed for total virions, proportion of penetrators, depth of virion penetration, as well as immune cell counts and depths in the tissue. We visualized individual PA virions breaching penile epithelial surfaces in the explant and macaque model. Using kernel density estimated probabilities of localizing a virion or immune cell at certain tissue depths revealed that interactions between virions and cells were more likely to occur in the inner foreskin or glans penis (from local or cadaveric donors, respectively). Using statistical models to account for repeated measures and zero-inflated datasets, we found no difference in total virions visualized at 4 hours between inner and outer foreskins from local donors. At 24 hours, there were more virions in inner as compared to outer foreskin (0.0495 +/- 0.0154 and 0.0171 +/- 0.0038 virions/image, p = 0.001). In the cadaveric specimens, we observed more virions in inner foreskin (0.0507 +/- 0.0079 virions/image) than glans tissue (0.0167 +/- 0.0033 virions/image, p<0.001), but a greater proportion was seen penetrating uncircumcised glans tissue (0.0458 +/- 0.0188 vs. 0.0151 +/- 0.0100 virions/image, p = 0.099) and to significantly greater mean depths (29.162 +/- 3.908 vs. 12.466 +/- 2.985 μm). Our in vivo macaque model confirmed that virions can breach penile squamous epithelia in a living model. In summary, these results suggest that the inner foreskin and glans epithelia may be important sites for HIV transmission in uncircumcised men
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