733 research outputs found
Steady-State Two Atom Entanglement in a Pumped Cavity
In this paper we explore the possibility of a steady-state entanglement of
two two-level atoms inside a pumped cavity by taking into account cavity
leakage and the spontaneous emission of photons by the atoms. We describe the
system in the dressed state picture in which the coherence is built into the
dressed states while transitions between the dressed states are incoherent. Our
model assumes the vacuum Rabi splitting of the dressed states to be much larger
than any of the decay parameters of the system which allows atom-field
coherence to build up before any decay process takes over. We show that, under
our model, a pumping field cannot entangle two closed two-level atoms inside
the cavity in the steady-state, but a steady-state entanglement can be achieved
with two open two-level atoms.Comment: 19 pages, 5 figure
Effects of Estrogen Treatment on the Responses of cAMP and Sex Steroids to hCG by the Testes of Patients with Prostatic Cancer
The effects of diethylstilbestrol diphosphate (DESDP) on testicular steroidogenesis were investigated in patients undergoing orchiectomy for prostatic carcinoma.
In non-DESDP treated patients the concentration of cAMP in the spermatic venous blood was 17.8 ± 3.1 (SE) pmoles/ml, which increased to 343.3 ± 18.6 (SE) pmoles/ml 30 min after hCG (1,000 IU) injection into the testis. T increased gradually from the pretreated level of 26.5 ± 7.2 (SE) μg/dl at 50 min. A slight increase in DHT was observed after hCG injection. Ten days' injections of DESDP significantly reduced the responses of T and DHT to hCG and 20 days' injections decreased T and DHT responses as well as cAMP response to hCG.
These findings indicate that DESDP can directly suppress the hCG stimulated steroidogenesis and cAMP production in human testis in vivo. The inhibitory effects of DESDP on Leydig cell function are probably on T biosynthesis as well as on cAMP formation
Direct Inhibitory Effects of 17β-Estradiol on hCG-Stimulated cAMP and Testosterone Responses of Canine Testis
The direct effects of 17β-estradiol (E2) on testicular function were investigated using in situ perfusion of canine testis. During perfusion of E2 (10^-8-10^-4M), we measured the concentrations of cAMP, testosterone (T), androstenedione and 5α-dihydrotestosterone (DHT) in the spermatic venous effluent after hCG (500 IU) injection into the spermatic artery.
The cAMP concentration in the spermatic venous effluent was 122 ± 3. 7 (SE) pmoles/ml, increasing after hCG to a peak level of 259.1 ± 33.0 (SE) pmoles/ml at 45 min and decreasing thereafter. T increased gradually from the pretreated level of 12.2 ± 4.4 (SE) mg/ml to 90.9 ± 30.9 (SE) ng/ml at 90 min after hCG injection. Androstenedione production was also stimulated by hCG. Although the pattern of changes of DHT in the venous effluent was similar to that of T, a statistical significant increase was not observed after hCG injection. Continuous infusion with E2 at the concentrations of 10^-8-^-4 M decreased hCG-induced cAMP increase in a dose-dependent fashion. The peak level of cAMP after hCG was shown to be increasingly depleted (50 and 80%) by the increasing doses of 10^-6 and 10^-4 M of exogenous E2. The responses of T and androstenedione were also suppressed by E2 and at 10^-4 M of E2 no increase was observed, although the response of cAMP to hCG remained. These findings indicate that E2 can directly suppress the hCG-stimulated steroidogenesis and cAMP production in in situ canine testis
Robust Multi-Partite Multi-Level Quantum Protocols
We present a tripartite three-level state that allows a secret sharing
protocol among the three parties, or a quantum key distribution protocol
between any two parties. The state used in this scheme contains entanglement
even after one system is traced out. We show how to utilize this residual
entanglement for quantum key distribution purposes, and propose a realization
of the scheme using entanglement of orbital angular momentum states of photons.Comment: 9 pages, 2 figure
Development of the Guernsey Community Participation and Leisure Assessment – Revised (GCPLA-R).
A sufficiently psychometrically robust measure of community and leisure participation of adults with intellectual disabilities was not in existence, despite research identifying this as an important outcome and a key contributor to quality of life. The current study aimed to update the Guernsey Community Participation and Leisure Assessment (GCPLA). Adults with intellectual disabilities, carers and experts were consulted in creating a revised pool of 46 items. These were then tested and data from 326 adults with intellectual disabilities were analysed for their component structure and psychometric properties. Principal Component analysis discovered a stable set of components describing seven different clusters. This revised measure (the GCPLA-R) was demonstrated to have satisfactory reliability, and scores were related to challenging behaviour and adaptive behaviour in theoretically consistent ways and were correlated with scores on comparable measures
Presence of Cell Wall Lytic Enzyme in Stable Staphylococcal L-Form
The stable L-form cells derived from Staphylococcus aureus 209P were examined for the presence of cell wall lytic enzymes. The enzyme preparations from cells and culture fluid of the parent strain lysed both Micrococcus lysodeikticus cells and S. aureus cells, whereas the enzyme preparations from the L-form lysed M. lysodeikticus cells but not S. aureus cells. Lipoteichoic acid, which has been reported to be a regulator of the lytic enzyme, inhibited both enzyme preparations from the parent strain and the L-form. However, the susceptibility of the enzyme preparation from the L-form to lipoteichoic acid was lower than that from the parent strain
Production of Insect Toxin Beauvericin From Entomopathogenic Fungi Cordyceps Militaris by Heterologous Expression of Global Regulator
Cordyceps militaris is one of entomopathogenic fungi species that is well known to be a traditional medicine in China for decades. Although the pharmaceutical and/or toxic properties of C. militaris has attracted attention as a promising resource for finding bioactive compounds, only a few substances including cordycepin have been reported so far. In the previous report heterologous expression of LaeA, a global regulator for secondary metabolites production in fungi, has been succeeded in C. militaris. The LaeA-engineered transformants are proved to produce new and/or elevated production of secondary metabolites, as detected by HPLC analysis. In order to further characterize the secondary metabolites that were being significantly produced by LaeA transformant, HPLC profiling and structure elucidation by proton NMR were conducted in two target compounds, designated as compound 1 and compound 2. Compound 1 possessed the highly similar characters to insect toxin beauvericin in UV spectrum, molecular weight, and retention time in HPLC analysis. Proton NMR analysis revealed that compound 1 had the same proton signals as beauvericin
Penicillin Resistance of Pseudomonas aeruginosa Clinical Isolates from Urinary Tract Infections
One hundred and thirteen clinical isolates of Pseudomonas aeruginosa from urinary tract infections were tested for their mechanisms of resistance to penicillins. Ninety-eight percent and 100.0% of the strains were resistant (MIC≧100 μg/ml) to ampicillin and penicillin G, respectively, while only 5.3% were resistant to piperacillin. Low permeability of the outer membrane, and penicillinase production were involved in their resistance mechanisms. Peptidoglycan synthesis in ether-treated cells of two representative strains was inhibited by ampicillin and piperacillin at the concentrations markedly lower than that for penicillin G
Effect of Hyperprolactinemia Induced by Prolactinoma (MtT/F84) on the Accessory Sexual Organs of Male Rat
A new transplantable prolactinoma, designated MtT/F84 has been serially passaged in female F344 rats. Persistently high levels of serum prolactin could be achieved in male F344 rats by MtT/F84 inoculating under the skin.
This investigation deals with the effects of hyperprolactinemia upon the accessory sexual organs of male rats during puberty. The weights and the concentrations of dihydrotestosterone (DHT) in the dorsal prostate increased significantly in rats with moderate hyperprolactinemia (756 ± 179 ng/ml), but they in rats with marked hyperprolactinemia (3612 ± 1089 ng/ml) were similar t.o those of control rats. In contrast, serum testosterone levels (0.52 ± 0/17 ng/ml) in those of hyperprolactinemic rats were significantly decreased compared to that of controls (1.11± 0.13 ng/ml).
These results suggested that the growth-promoting effect of prolactin on the rat prostate mediated through the action of androgen varied according to the degree of hyperprolactinemia
Orthogonal Regulatory Circuits for Escherichia coli Based on the gamma-Butyrolactone System of Streptomyces coelicolor
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