In this work we analyze the incidence of the plates' thickness on the Casimir force and radiative heat transfer for a configuration of parallel plates in a non-equilibrium scenario, relating to ...Lifshitz's and Landauer's formulas. From a first-principles canonical quantization scheme for the study of the matter-field interaction, we give closed-form expressions for the non-equilibrium Casimir force and the heat transfer between plates of thickness \(d_{\rm L},d_{\rm R}\). We distinguish three different contributions to the Casimir force and to the heat transfer in the general non-equilibrium situation: two associated to each of the plates, and one to the initial state of the field. We analyze the dependence of the Casimir force and heat transfer with the plate thickness (setting \(d_{\rm L}=d_{\rm R}\equiv d\)), showing the scale at which each magnitude converges to the value of infinite thickness (\(d\rightarrow+\infty\)) and how to correctly reproduce the non-equilibrium Lifshitz's formula. For the heat transfer, we show that Landauer's formula does not apply to every case (where the three contributions are present), but it is correct for some specific situations. We also analyze the interplay of the different contributions for realistic experimental and nanotechnological conditions, showing the impact of the thickness in the measurements. For small thickness (compared to the separation distance), the plates act to decrease the background blackbody flux, while for large thickness the heat is given by the baths' contribution only. The combination of these behaviors allows for the possibility of having a tunable minimum in the heat transfer that is experimentally attainable and observable for metals, and also of having vanishing heat flux in the gap when those difference are of opposite signs (thermal shielding). These features turns out to be relevant for nanotechnological applications.
Benign prostatic hyperplasia (BPH) is an androgen-dependent disease; it
originates exclusively in the inner prostate, which includes tissue
surrounding the urethra. Stromal-epithelial interaction has ...a pivotal
role in the regulation of the development and growth of the prostate,
and locally produced peptide growth factors are considered important
mediators of this interaction. Insulin-like growth factor I (IGF-I) and
IGF-II, acting mainly through type 1 IGF receptor (IGFR1), have
mitogenic and antiapoptotic effects on epithelial and stromal prostatic
cells. In this study the expression of IGF-I, IGF-II, and IGFR1
messenger ribonucleic acid (mRNA), the immunoreactive content of IGF-I
(irIGF-I) and IGF-II (irIGF-II) were determined in periurethral,
intermediate, and subcapsular regions of BPH tissue to verify their
possible regional variation; a correlation to the tissue levels of
dihydrotestosterone (DHT) and 3α-androstanediol (3αDiol) was also
determined to verify their possible androgen dependence.
Prostates were removed by suprapubic prostatectomy from 14 BPH patients
and sectioned in the periurethral, intermediate, and subcapsular
regions. Gene expression of IGF-I, IGF-II, and IGFR1 was evaluated by
semiquantitative RT-PCR, using β-actin as a control. irIGF-I was
measured by RIA, and irIGF-II was measured by IRMA after acidification
and chromatography on Sep-Pak C18 cartridges. DHT and
3αDiol concentrations were evaluated by RIA after extraction and
purification on Celite microcolumns.
IGF-II and IGFR1, but not IGF-I, mRNA was higher in the periurethral
than in the intermediate (P < 0.05) and
subcapsular (P < 0.01) region. Also, prostatic
levels of irIGF-II, expressed as picomoles per g tissue, were higher in
the periurethral (20.84 ± 1.84) than in the intermediate
(14.81 ± 2.11; P < 0.05) and subcapsular
(10.88 ± 1.21; P < 0.001) region. No
significant differences were found in irIGF-I content. Considering
prostatic androgen levels, DHT and 3αDiol presented a regional
variation, with the highest concentrations in the periurethral region.
IGF-II mRNA and irIGF-II levels were positively correlated with both
DHT and 3αDiol content.
These results demonstrate that in BPH tissue a greater IGF-II activity
is present in the periurethral region, the site of origin of BPH.
Moreover, we can hypothesize that the tissue androgen content may
modulate prostatic production of IGF-II, acting at the transcriptional
and probably the posttranscriptional level. Therefore, even though
further studies will need to confirm this hypothesis, DHT may increase
IGF-II activity, mainly in the periurethral region, which, in turn,
induces, through IGFR1, benign proliferation of both epithelial and
stromal cells, characteristic of BPH.
In an ethnically homogeneous population of women living in Tuscany, Italy, the relationships between age, body weight, bone mineral density and the vitamin D receptor (VDR) gene polymorphism were ...studied, with the objective of recognizing patients at risk for osteoporosis. In 275 women bone mineral density was measured by Dual Energy X-rays Absorptiometry (DEXA). In 50 of them the individual genetic pattern for VDR was evaluated by DNA extraction followed by PCR amplification of the VDR gene, and digestion with the restriction enzyme BsmI. Age and bone mineral density were inversely related (R2 = 0.298). Body weight was associated with bone mineral density (R2 = 0.059), but not with age. In osteoporotic women, mean (+/- SD) body weight was 59.9 +/- 6.5 Kg, lower than that recorded in non osteoporotic women (64.2 +/- 9.4 Kg), even though not significantly different (p = 0.18). No association was found between VDR gene polymorphism, bone density or body weight. The performance of anthropometric and genetic components appear to be poor, and, at least for the time being, bone mineral density measurement by means of MOC-DEXA represents the optimal method to detect women at risk for postmenopausal osteoporosis.
Uniform title: The bohemian. Extract
Titre uniforme : Rigoletto. Extrait
Titre uniforme : Manon Lescaut. Extrait
Titre uniforme : La bohème. Extrait
Titre uniforme : La Gioconda. Extrait
Titre ...uniforme : Andrea Chénier. Extrait
Titre uniforme : Adriana Lecouvreur. Extrait
Titre uniforme : La sonnambula. Extrait
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Titre uniforme : Rigoletto. Extrait
Titre uniforme : Manon Lescaut. Extrait
Titre uniforme : La bohème. Extrait
Titre uniforme : La Gioconda. Extrait
Titre uniforme : Andrea Chénier. Extrait
Titre uniforme : Adriana Lecouvreur. Extrait
Titre uniforme : La sonnambula. Extrait
Comprend : La Somnambule / Bellini - La Bohême / Puccini - LA GIOCONDA / Ponchielli - Manon Lescaut / Puccini - RIGOLETTO / Verdi - Adrienne Lecouvreur / Cilea - André Chenier / Giordano
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Contient une table des matières
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