RF and IF mixer optimum matching impedances extracted by large-signal vectorial measurements

This paper introduces a new technique that allows us to measure the admittance conversion matrix of a two-port device,using a Nonlinear Vector Network Analyzer.This method is applied to extract the conversion matrix of a 0.2 µµµµm pHEMT,driven by a 4.8 GHz pump signal,at different power levels,using an intermediate frequency of 600 MHz.The issue on data inconsistency due to phase randomization among different measurements is discussed and a proper pre- processing algorithm is proposed to fix the problem. The output of this work consists of a comprehensive experimental evaluation of up-and down-conversion maximum gain,stability,and optimal RF and IF impedances

Serotonin-mediated tuning of human helper T cell responsiveness to the chemokine CXCL12

In addition to its role as neurotransmitter, serotonin (5-HT) is an important modulator of inflammation and immunity. Here, we report novel findings suggesting a 5-HT involvement in T cell migration. In particular, we show that 5-HT tunes the responsiveness of human T lymphocytes to the broadly expressed chemokine CXCL12 in transwell migration assays. By real-time PCR, western blot analysis and electrophysiological patch clamp experiments, we demonstrate that the type 3 5-HT receptor (5-HT 3) is functionally expressed in human primary T cells. In addition, specific 5-HT 3 receptor agonists selectively decrease T cell migration towards gradients of CXCL12 but not of inflammatory chemokines, such as CCL2 and CCL5. In transmigration experiments, 5-HT 3 receptor stimulation reverts the inhibitory effect of endothelial-bound CXCL12 on T cell migration. Our data suggest that the reduced T cell responsiveness to CXCL12 induced by 5-HT may occur to facilitate T cell extravasation and migration into inflamed tissues

Global access to affordable direct oral anticoagulants

Poor control of cardiovascular disease accounts for a substantial proportion of the disease burden in developing countries, but often essential anticoagulant medicines for preventing strokes and embolisms are not widely available. In 2019, direct oral anticoagulants were added to the World Health Organization's WHO Model list of essential medicines. The aims of this paper are to summarize the benefits of direct oral anticoagulants for patients with cardiovascular disease and to discuss ways of increasing their usage internationally. Although the cost of direct oral anticoagulants has provoked debate, the affordability of introducing these drugs into clinical practice could be increased by: price negotiation; pooled procurement; competitive tendering; the use of patent pools; and expanded use of generics. In 2017, only 14 of 137 countries that had adopted national essential medicines lists included a direct oral anticoagulant on their lists. This number could increase rapidly if problems with availability and affordability can be tackled. Once the types of patient likely to benefit from direct oral anticoagulants have been clearly defined in clinical practice guidelines, coverage can be more accurately determined and associated costs can be better managed. Government action is required to ensure that direct oral anticoagulants are covered by national budgets because the absence of reimbursement remains an impediment to achieving universal coverage. Tackling cardiovascular disease with the aid of direct oral anticoagulants is an essential component of efforts to achieve the World Health Organization's target of reducing premature deaths due to noncommunicable disease by 25% by 2025

Indurimento superficiale di leghe di alluminio mediante diffusione di rame

Lo scopo di questo lavoro è quello di sviluppare un processo per incrementare la durezza superficialedelle leghe di alluminio 2024 e 7075 mediante trattamenti di diffusione di rame, depositato elettroliticamentesulla superficie. I trattamenti diffusivi sono stati effettuati in forno in atmosfera inerte a temperaturecomprese nell’intervallo 470-500 °C per un tempo massimo di 24 h, seguiti da trattamenti di solubilizzazionee invecchiamento. I campioni sono stati caratterizzati mediante analisi al microscopio ottico (OM),microscopia elettronica a scansione (SEM), diffrazione a raggi X (XRD) e misure di microdurezza Vickers.La lega 2024, in seguito ai trattamenti di diffusione del rame condotti a temperature prossime ai 495 °C,raggiunge una durezza superficiale di 500 HV0,1, contro 80 HV0,1 del cuore del campione.Ciò è dovuto alla formazione dell’intermetallico Al2Cu. Il trattamento di invecchiamento non influenzalo spessore di diffusione che rimane di circa 50 ?m, bensì modifica la durezza in maniera diversa a secondache l’invecchiamento sia naturale o artificiale. I trattamenti di diffusione condotti sulla lega 7075 atemperature prossime a 500 °C provocano la diffusione del rame fino ad una profondità di 600 ?m e causanouna parziale fusione degli intermetallici superficiali, non permettendo di ottenere un aumento significativodella durezza superficiale. Abbassando la temperatura del trattamento diffusivo (470 °C), la zona interessatadalla diffusione del rame è di circa 100 ?m con una durezza di 860 HV0,1, dovuta alla formazione diintermetallici Al-Cu e Zn-Cu. Anche in questo caso, il successivo invecchiamento artificiale non varia lospessore di diffusione, ma porta ad una diminuzione della durezza superficiale a valori attorno a 500 HV0,1

Quantum dot-doped silica nanoparticles as probes for targeting of T-lymphocytes

To enhance diagnostic or therapeutic efficacy, novel nanomaterials must be engineered to function in biologically relevant environments, be visible by conventional fluorescent microscopy, and have multivalent loading capacity for easy detection or effective drug delivery. Here we report the fabrication of silica nanoparticles doped with quantum dots and superficially functionalized with amino and phosphonate groups. The amino groups were acylated with a water-soluble biotin-labeling reagent. The biotinylated nanoparticles were subsequently decorated with neutravidin by exploiting the strong affinity between neutravidin and biotin. The resultant neutravidin-decorated fluorescent silica nanoparticles stably dispersed under physiological conditions, were visible by conventional optical and confocal fluorescent microscopy, and could be further functionalized with macromolecules, nucleic acids, and polymers. We also coated the surface of the nanoparticles with biotinylated mouse anti-human CD3 (αCD3). The resultant fluorescent nanoassembly was taken up by Jurkat T cells through receptor-mediated endocytosis and was partially released to lysosomes. Thus, quantum dot-doped silica nanoparticles decorated with neutravidin represent a potentially excellent scaffold for constructing specific intracellular nanoprobes and transporters

Short-term reproducibility of nocturnal non-dipping pattern in recently diagnosed essential hypertensives.

Objective: To investigate in a selected population of patients with a recently diagnosed essential hypertension the short-term intrasubject variability of diurnal changes in blood pressure (BP). Methods: Two hundred and eight consecutive, recently diagnosed, never treated essential hypertensives (119 men, 89 women, 46 ± 12 years) underwent 24-h ambulatory BP monitoring (ABPM) twice within 3 weeks. Dipping pattern was defined as a reduction in average systolic and diastolic BP at night greater than 10% compared to average daytime values. Results: 177 subjects (85%) showed no change in their diurnal variations in BP. Of the 159 subjects who had a dipping pattern on first ABPM, 134 (90.6%) confirmed this type of profile on the second ABPM, while 15 (9.4%) showed a non-dipping pattern. Of the 59 subjects who had a non-dipping pattern on the first ABPM, 43 (72.2%) confirmed their initial profile on the second ABPM, while 16 (28.8%) did not. Conclusion: These findings indicate that short-term reproducibility of diurnal changes in BP in early phases of untreated essential hypertension, characterized by a large prevalence of dipping pattern, is overall satisfactory. However, our study underlines that also in this particularly selected population of hypertensives the definition of non-dipping status on the basis of a single ABPM remains unreliable in about one-third of patients

A Mechanism for the Oxygen and Iron Bimodal Radial Distribution Formation in the Disc of our Galaxy

Recently it has been proposed that there are two types of SN Ia progenitors -- short-lived and long-lived. On the basis of this idea, we develope a theory of a unified mechanism for the formation of the bimodal radial distribution of iron and oxygen in the Galactic disc. The underlying cause for the formation of the fine structure of the radial abundance pattern is the influence of spiral arms, specifically, the combined effect of the corotation resonance and turbulent diffusion. From our modelling we conclude that to explain the bimodal radial distributions simultaneously for oxygen and iron and to obtain approximately equal total iron output from different types of supernovae, the mean ejected iron mass per supernova event should be the same as quoted in literature if maximum mass of stars, that eject heavy elements, is $50 M_{\odot}$. For the upper mass limit of $70 M_{\odot}$ the production of iron by a supernova II explosion should be increased by about 1.5 times.Comment: 7 pages, 6 figures, MNRAS submitte

Searching for GC-like abundance patterns in young massive clusters

Studies during the last decade have revealed that nearly all Globular Clusters (GCs) host multiple populations (MPs) of stars with a distinctive chemical patterns in light elements. No evidence of such MPs has been found so far in lower-mass ($10^5$ M$_{\odot}$) clusters in the Local Group. Young massive clusters (YMCs) have masses and densities similar to those expected of young GCs in the early universe, and their near-infrared (NIR) spectra are dominated by the light of red super giants (RSGs). The spectra of these stars may be used to determine the cluster's abundances, even though the individual stars cannot be spatially resolved from one another. We carry out a differential analysis between the Al lines of YMC NGC 1705: 1 and field Small Magellanic Cloud RSGs with similar metallicities. We exclude at high confidence extreme [Al/Fe] enhancements similar to those observed in GCs like NGC 2808 or NGC 6752. However, smaller variations cannot be excluded

The Herschel Virgo Cluster Survey: X.The relationship between cold dust and molecular gas content in Virgo spirals

Using the far-infrared emission, as observed by the Herschel Virgo Cluster Survey (HeViCS), and the integrated HI and CO brightness, we infer the dust and total gas mass for a magnitude limited sample of 35 metal rich spiral galaxies in Virgo. The CO flux correlates tightly and linearly with far-infrared fluxes observed by Herschel. Molecules in these galaxies are more closely related to cold dust rather than to dust heated by star formation or to optical/NIR brightness. We show that dust mass establishes a stronger correlation with the total gas mass than with the atomic or molecular component alone. The dust-to-gas ratio increases as the HI deficiency increases, but in highly HI deficient galaxies it stays constant. Dust is in fact less affected than atomic gas by weak cluster interactions, which remove most of the HI gas from outer and high latitudes regions. Highly disturbed galaxies, in a dense cluster environment, can instead loose a considerable fraction of gas and dust from the inner regions of the disk keeping constant the dust-to-gas ratio. There is evidence that the molecular phase is also quenched. This quencing becomes evident by considering the molecular gas mass per unit stellar mass. Its amplitude, if confirmed by future studies, highlights that molecules are missing in Virgo HI deficient spirals, but to a somewhat lesser extent than dust.Comment: 11 pages, 8 figures. Accepted for publication in A&

Loco-regional adjuvant radiation therapy in breast cancer patients with positive axillary lymph-nodes at diagnosis (CN2) undergoing preoperative chemotherapy and with complete pathological lymph-nodes response. Development of GRADE (Grades of recommendation, assessment, Development and Evaluation) recommendation by the Italian Association of radiation therapy and Clinical Oncology (AIRO)

Objective: To perform a meta-analysis to determine the effect of loco-regional radiation therapy (RT) compared to no loco-regional RT for operated patients in clinical stage cN2 breast cancer at diagnosis and ypN0 after preoperative chemotherapy (PST). Material and Methods: Eligible studies were identified through a systematic search of the medical literature performed independently by two researchers using a validated search strategy. An electronic search of Medline via PubMed and Embase (Breast cancer AND preoperative chemotherapy AND radiation therapy) was conducted with no language or publication status restrictions. The effect of loco-regional RT on overall (OS), disease free (DFS), loco-regional recurrence-free (LRRFS) survival and local recurrence was evaluated. An electronic search of Medline via PubMed and Embase (Toxicity AND radiation therapy breast cancer AND preoperative therapy; toxicity AND breast surgery AND preoperative chemotherapy) was conducted for outcomes of harm: major acute and late skin toxicity, lymphedema and cardiac events. Results: Of 333 studies identified, 4 retrospective studies reporting on a total of 1107 patients were included in the meta-analysis. Six and 3 reported data of acute and late skin toxicity, while 2 studies provided information on cardiac events. Pooled results showed no difference in terms of hazard ratio for loco-regional RT versus no loco-regional RT [hazard ratio (HR) = 0.82, 95% confidence interval (CI) 0.63\u20131.68]. Loco-regional RT was associated with an OS benefit in the subgroup analysis: IIIB-C (loco-regional RT 79.3% vs no loco-regional RT 71.2%, p = 0.027) and T3-T4 (loco-regional RT 82.6% vs no loco-regional RT 76.6%, p = 0.025). No difference was shown in terms of 5-year DFS (loco-regional RT 91.2% vs no loco-regional RT 83%, p = 0.441) and LRRFS (loco-regional RT 98.1% vs no loco-regional RT 92.3%, p = 0.148). There was no significant difference between the groups in terms of acute and late skin toxicities, lymphedema and cardiac events. Conclusions: Because of the limitations due to the small number of studies and heterogeneity in the analysis, the present study does not allow to draw any definitive conclusion, highlighting the need for well-controlled trials to determine the effect of loco-regional RT in patients with cN2 having a pathological complete response in the axillary nodes after preoperative chemotherapy