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We investigate the extreme X-ray variability of a z = 1.608 active galactic nucleus in the 7 Ms Chandra Deep Field-South (XID 403), which showed two significant X-ray brightening events. In the first event, XID 403 brightened by a factor of $>2.5$ in $\lesssim6.1$ rest-frame days in the observed-frame 0.5-5 keV band. The event lasted for $\approx5.0\textrm{-}7.3$ days, and then XID 403 dimmed by a factor of $>6.0$ in $\lesssim6.1$ days. After $\approx1.1\textrm{-}2.5$ years in the rest frame (including long observational gaps), it brightened again with the 0.5-5 keV flux increasing by a factor of $>12.6$. The second event lasted over 251 days and the source remained bright until the end of the 7 Ms exposure. The spectrum is a steep power law (photon index $Γ=2.8\pm0.3$) without obscuration during the second outburst, and the rest-frame 2-10 keV luminosity reaches $1.5^{+0.8}_{-0.5}\times10^{43}$ erg s$^{-1}$; there is no significant spectral evolution within this epoch. The infrared-to-UV spectral energy distribution of XID 403 is dominated by the host galaxy. There is no significant optical/UV variability and $R$-band (rest-frame $\approx2500$ $\unicode{xC5}$) brightening contemporaneous with the X-ray brightening. The extreme X-ray variability is likely due to two X-ray unveiling events, where the line of sight to the corona is no longer shielded by high-density gas clumps in a small-scale dust-free absorber. XID 403 is probably a high-redshift analog of local narrow-line Seyfert 1 galaxies, and the X-ray absorber is a powerful accretion-disk wind. On the other hand, we cannot exclude the possibility that XID 403 is an unusual candidate for tidal disruption events., 23 pages, 9 figures, accepted for publication in ApJ

We study the ensemble X-ray variability properties of Active Galactic Nuclei (AGN) over a large range of timescales (20 ks $\leq T\leq$ 14 yrs), redshift ($0\leq z \lesssim 3$), luminosities ($10^{40}$ erg s$^{-1}\leq L_X\leq 10^{46}$ erg s$^{-1}$) and black hole (BH) masses ($10^6 \leq $M$_\odot \leq 10^9$). We propose the use of the variance-frequency diagram, as a viable alternative to the study of the power spectral density (PSD), which is not yet accessible for distant, faint and/or sparsely sampled AGN. We show that the data collected from archival observations and previous literature studies are fully consistent with a universal PSD form which does not show any evidence for systematic evolution of shape or amplitude with redshift or luminosity, even if there may be differences between individual AGN at a given redshift or luminosity. We find new evidence that the PSD bend frequency depends on BH mass and, possibly, on accretion rate. We finally discuss the implications for current and future AGN population and cosmological studies., Comment: In press on Astronomy and Astrophysics

Herein we report the anaerobic cleavage of alkenes into carbonyl compounds using nitroarenes as oxygen transfer reagents under visible light. This approach serves as a safe and practical alternative to mainstream oxidative cleavage protocols, such as ozonolysis and the Lemieux-Johnson reaction. A wide range of alkenes possessing oxidatively sensitive functionalities underwent anaerobic cleavage to generate carbonyl derivatives with high efficiency and regioselectivity. Mechanistic studies support that the transformation occurs via direct photoexcitation of the nitroarene followed by a nonstereospecific radical cycloaddition event with alkenes. This leads to 1,3,2- and 1,4,2-dioxazolidine intermediates that fragment to give the carbonyl products. A combination of radical clock experiments and

Very-high Energy (VHE) gamma-ray astroparticle physics is a relatively young field, and observations over the past decade have surprisingly revealed almost two hundred VHE emitters which appear to act as cosmic particle accelerators. These sources are an important component of the Universe, influencing the evolution of stars and galaxies. At the same time, they also act as a probe of physics in the most extreme environments known - such as in supernova explosions, and around or after the merging of black holes and neutron stars. However, the existing experiments have provided exciting glimpses, but often falling short of supplying the full answer. A deeper understanding of the TeV sky requires a significant improvement in sensitivity at TeV energies, a wider energy coverage from tens of GeV to hundreds of TeV and a much better angular and energy resolution with respect to the currently running facilities. The next generation gamma-ray observatory, the Cherenkov Telescope Array Observatory (CTAO), is the answer to this need. In this talk I will present this upcoming observatory from its design to the construction, and its potential science exploitation. CTAO will allow the entire astronomical community to explore a new discovery space that will likely lead to paradigm-changing breakthroughs. In particular, CTA has an unprecedented sensitivity to short (sub-minute) timescale phenomena, placing it as a key instrument in the future of multi-messenger and multi-wavelength time domain astronomy. I will conclude the talk presenting the first scientific results obtained by the LST-1, the prototype of one CTAO telescope type - the Large-Sized Telescope, that is currently under commission., PoS: Proceedings of Science, 395, ISSN:1824-8039, Proceedings of 37th International Cosmic Ray Conference (ICRC2021)

Objective Neurocognitive performance among older persons, including those living with HIV (people living with HIV [PLWH]), exhibits significant heterogeneity, suggesting subpopulations with differing profiles of neurocognitive impairment (NCI). Metabolic factors are associated with NCI, but their relationships to cluster-derived NCI profiles are unknown. Method Participants (144 PLWH and 102 HIV uninfected) aged 50+ years completed a neuropsychological battery assessing seven cognitive domains. Latent class analysis (LCA) identified NCI profiles separately by HIV serostatus and in a combined sample. Obtained classes were examined against the Montreal Cognitive Assessment (MoCA) and diagnoses of HIV-associated neurocognitive disorders (HAND). Multinomial regression identified metabolic predictors of classification. Results LCA identified three latent classes in each participant sample: Class1Multidomain NCI (high probability of impairment across multiple domains), Class 2Learning & Recall NCI (high probability of impairment in learning and recall), and Class 3NC Unimpaired (low probability of NCI across all domains). Severity of NCI implied by classes corresponded with MoCA scores and HAND diagnoses. In analyses on the combined sample, compared to HIV-uninfected individuals, PLWH were more likely to be in Class1Multidomain NCI. Among PLWH, those with dyslipidemia and hypertension had greater odds of classification in Class 1Multidomain NCI while those with central obesity had higher odds of classification in Class 2Learning & Recall NCI; metabolic syndrome approached significance as a differential predictor. Regardless of HIV status, individuals with diabetes were more likely to be in Class 1Multidomain NCI. Conclusions Metabolic risk factors confer heightened risk of NCI in HIV infection. Interventions to reduce metabolic risk may improve neurocognitive outcomes among PLWH.

We present a study of the intra-cluster population of low-mass X-ray binaries (LMXB) residing in globular clusters (GC) in the central 1 $deg^2$ of the Fornax galaxy cluster. Differently from previous studies, which were restricted to the innermost regions of individual galaxies, this work is aimed at comparing the properties of the intra-cluster population of GC-LMXBs with those of the host galaxy. We use VLT Survey Telescope (VST) and Chandra observations. We identify 168 LMXBs residing in GCs and divide it into host-galaxy and intra-cluster objects based on their distance from the nearest galaxy in terms of effective radius. We found 82 intra-cluster GC-LMXBs and 86 objects that are hosted in galaxies. We perform a Gaussian mixture model to divide the population into red and blue GCs. As has been found for the innermost regions of galaxies, LMXBs tend to form in red and bright GCs in intra-cluster space as well. We find, however, that the likelihood of a red GC to host an LMXB decreases with galactocentric distance, but it remains approximately constant for the blue GC population. Investigating the X-ray properties of the LMXBs residing in GCs, we find a difference in the X-ray luminosity function between the intra-cluster and host-galaxy sample: both follow a power-law down to $\sim 8.5\times 10^{37}$ erg s$^{-1}$, which is consistent with field LMXBs for the intra-cluster sample, while the latter agree with previous estimates for LMXBs in GCs. We detect a tentative difference in the hardness ratio of two populations, where the intra-cluster GC-LMXBs appear to have harder spectra than the host-galaxy objects. We find the same trend when we compare red and blue GC-LMXBs: the spectra of the blue sample are harder spectra than those of the red sample. This result could suggest a relation between the spectral properties of LMXBs and the host GC colour and therefore its metallicity., Comment: Accepted by A&A

A methodology is reported for preparing amides using amines as an acyl source. The protocol involves the visible-light-promoted oxidative amidation of amines with pyrazole to synthesize N-acyl pyra...

We present an alcohol oxidation strategy to access α-trifluoromethyl ketones (TFMKs) merging catalytic oxoammonium cation oxidation with visible-light photoredox catalysis. This work uses 4-acetamido-(2,2,6,6-tetramethyl-piperidin-1-yl)oxyl as an organic oxidant capable of generating TFMKs in good yields. The methodology serves as an improvement over previous reports of an analogous oxidation strategy requiring superstoichiometric quantities of oxidant. Both primary and secondary non-fluorinated alcohols can also be oxidised in good yields.

As part of the Fornax Deep Survey with the ESO VLT Survey Telescope, we present new $g$ and $r$ bands mosaics of the SW group of the Fornax cluster. It covers an area of $3 \times 2$ square degrees around the central galaxy NGC1316. The deep photometry, the high spatial resolution of OmegaCam and the large covered area allow us to study the galaxy structure, to trace stellar halo formation and look at the galaxy environment. We map the surface brightness profile out to 33arcmin ($\sim 200$kpc $\sim15R_e$) from the galaxy centre, down to $\mu_g \sim 31$ mag arcsec$^{-2}$ and $\mu_r \sim 29$ mag arcsec$^{-2}$. This allow us to estimate the scales of the main components dominating the light distribution, which are the central spheroid, inside 5.5 arcmin ($\sim33$ kpc), and the outer stellar envelope. Data analysis suggests that we are catching in act the second phase of the mass assembly in this galaxy, since the accretion of smaller satellites is going on in both components. The outer envelope of NGC1316 still hosts the remnants of the accreted satellite galaxies that are forming the stellar halo. We discuss the possible formation scenarios for NGC1316, by comparing the observed properties (morphology, colors, gas content, kinematics and dynamics) with predictions from cosmological simulations of galaxy formation. We find that {\it i)} the central spheroid could result from at least one merging event, it could be a pre-existing early-type disk galaxy with a lower mass companion, and {\it ii)} the stellar envelope comes from the gradual accretion of small satellites., Comment: Accepeted for publication in ApJ

Clinical effectiveness of botulinum toxin (BTX) in the treatment of both neurogenic and idiopathic detrusor overactivity has been demonstrated in several studies. However, different protocols and techniques have been used by authors. Methods. Literature review on intradetrusor injection of BTX for detrusor overactivity. Results. The greatest clinical experience reports the use of 200 and 300 U Botox®. Available data suggest that clinical efficacy, duration, and the side effect profile is similar at these doses. Very few data, on the other hand, are available regarding the clinical outcomes using the Dysport® preparation; isolated reports support that efficacy is similar when using a dosing range of 500 to 1000 SU with increased risk of systemic side effects using 1000 SU. A variety of injection volumes was used, demonstrating similar efficacy and tolerability profile. Clinical effect duration extends six to ten months in the majority of studies. Data suggest that a repeated injection scheme proves successful in the vast majority of initial responders. Conclusions. Safety, effectiveness, specificity and reversibility make BTX a new attractive treatment modality for overactive bladder syndrome. However, more experience is needed to standardize the injection protocol with respect to therapeutic outcomes and adverse effects.

Clinical effectiveness of botulinum toxin (BTX) in the treatment of both neurogenic and idiopathic detrusor overactivity has been demonstrated in several studies. However, different protocols and techniques have been used by authors. METHODS. Literature review on intradetrusor injection of BTX for detrusor overactivity. RESULTS. The greatest clinical experience reports the use of 200 and 300 U Botox®. Available data suggest that clinical efficacy, duration, and the side effect profile is similar at these doses. Very few data, on the other hand, are available regarding the clinical outcomes using the Dysport® preparation; isolated reports support that efficacy is similar when using a dosing range of 500 to 1000 SU with increased risk of systemic side effects using 1000 SU. A variety of injection volumes was used, demonstrating similar efficacy and tolerability profile. Clinical effect duration extends six to ten months in the majority of studies. Data suggest that a repeated injection scheme proves successful in the vast majority of initial responders. CONCLUSIONS. Safety, effectiveness, specificity and reversibility make BTX a new attractive treatment modality for overactive bladder syndrome. However, more experience is needed to standardize the injection protocol with respect to therapeutic outcomes and adverse effects.

We present a wide field study of the Globular Clusters/Low Mass X-ray Binaries connection in the cD elliptical NGC1399, combining HST/ACS and Chandra high resolution data. We find evidence that LMXB formation likelihood is influenced by GCs structural parameters, in addition to the well known effects of mass and metallicity, independently from galactocentric distance., in press in the Proceedings of the X-ray 2009 Conference, 7-11 September 2009, Bologna, Italy

Sensitive surveys of the X-ray universe have been limited to small areas of the sky due to the intrinsically small field of view of Wolter-1 X-ray optics. High angular resolution is needed to achieve a low background per source, minimize source confusion, and distinguish point from extended objects. WFXT consists of three co-aligned wide field X-ray telescopes with a 1 degrees field of view and a less than or similar to 10 '' (goal of 5 '') angular resolution (HEW) over the full field. Total effective area at 1 keV will be > 5000 cm(-2). WFXT will perform three extragalactic surveys that will cover most of the sky to 100-1000 times the sensitivity of the ROSAT All Sky Survey, greater than or similar to 2000 deg(2) to deep Chandra or XMM-Newton sensitivity, and greater than or similar to 100 deg(2) to the deepest Chandra sensitivity. WFXT will generate a legacy X-ray dataset of a half million clusters and groups of galaxies to z approximate to 2, also characterizing the physics of the intracluster gas for a significant fraction of them, thus providing an unprecedented data set for cosmological applications; it will detect > 10(7) AGN to z > 6, again obtaining spectra for a substantial fraction, to study the growth of supermassive black holes; it will detect > 10(5) normal/starburst galaxies; and it will detect and characterize star formation regions across the Galaxy. WFXT is the only X-ray survey mission that will match, in area and sensitivity, the next generation of wide-area optical, IR and radio surveys.

Recent work on nearby AGNs has shown that X-ray variability is correlated with the mass and accretion rate onto the central SMBH. Here we present the application of the variability-luminosity relation to high redshift AGNs in the CDFS, making use of XMM-Newton observations. We use Monte Carlo simulations in order to properly account for bias and uncertainties introduced by the sparse sampling and the very low statistics. Our preliminary results indicate that BH masses span over the range from 10^5 to 10^9 solar mass while accretion rates range from 10^-3 up to values greater than 1, in unit of Eddington accretion rate., Comment: 2 pages, 2 figures,in press in the X-ray 2009 Conference Proceedings (Bologna, 7-11 September 2009)

Metabotropic glutamate receptors have been shown to potentiate the cyclic adenosine monophosphate (cAMP) formation induced by activation of several receptors linked to adenylyl cyclase via Gs-protein. Here we show that, in primary cultures of striatal neurons, group I metabotropic receptors potentiate the cAMP formation induced by activation of D1-like dopamine receptors. Reverse transcription associated with polymerase chain reaction revealed that mGluR5, mGluR3, mGluR4 and mGluR7 are present in striatal cell cultures. The potentiation of cAMP formation is induced by the selective group I mGluRs agonist (S)-3,5-dihydroxyphenylglycine and by other non-selective mGluRs agonists with a typical group I-like pharmacology (quisqualateibotenate1-aminocyclopentane-1,3-dicarboxylic acid). The rank order potency of mGluRs agonists in potentiating cAMP formation correlates with their ability to induce inositol phosphates production; the potentiation of cAMP formation and the inositol phosphates production are blocked by the group I mGluRs antagonists (S)-4-carboxyphenylglycine and are not affected by group II antagonist 2S,3S,4S)-2-methyl-2-(carboxycyclopropyl)-glycine or group III antagonist (S)-2-amino-2-methyl-4-phosphonobutanoic acid. The potentiating mechanism involves the activation of protein kinase C, being mimicked by phorbol-12-myristate-13acetate and blocked by the specific protein kinase C inhibitors bisindolylmaleimide I and chelerythrine or by protein kinase C downregulation. Our results indicate that this interaction could have a functional importance in modulating the cAMP-dependent transmission in the striatum.

Endogenous electric fields are instructive during embryogenesis by acting to direct cell migration, and postnatally, they can promote axonal growth after injury (McCaig 1991, Al-Majed 2000). However, the mechanisms for these changes are not well understood. Application of an appropriate electrical stimulus may increase the rate and success of nerve repair by directly promoting axonal growth. Previously, DC electrical stimulation at 50 mV/mm (1 mA, 8 h duration) was shown to promote neurite outgrowth and a more pronounced effect was observed if both peripheral glia (Schwann cells) and neurons were co-stimulated. If electrical stimulation is delivered to an injury site, both the neurons and all resident non-neuronal cells [e.g., Schwann cells, endothelial cells, fibroblasts] will be treated and this biophysical stimuli can influence axonal growth directly or indirectly via changes to the resident, non-neuronal cells. In this work, non-neuronal cells were electrically stimulated, and changes in morphology and neuro-supportive cells were evaluated. Schwann cell response (morphology and orientation) was examined after an 8 h stimulation over a range of DC fields (0–200 mV/mm, DC 1 mA), and changes in orientation were observed. Electrically prestimulating Schwann cells (50 mV/mm) promoted 30% more neurite outgrowth relative to co-stimulating both Schwann cells with neurons, suggesting that electrical stimulation modifies Schwann cell phenotype. Conditioned medium from the electrically prestimulated Schwann cells promoted a 20% increase in total neurite outgrowth and was sustained for 72 h poststimulation. An 11-fold increase in nerve growth factor but not brain-derived neurotrophic factor or glial-derived growth factor was found in the electrically prestimulated Schwann cell-conditioned medium. No significant changes in fibroblast or endothelial morphology and neuro-supportive behavior were observed poststimulation. Electrical stimulation is widely used in clinical settings; however, the rational application of this cue may directly impact and enhance neuro-supportive behavior, improving nerve repair.

The subject of this paper is to present the basic ideas for the organization of a software package developed at ELECTRICITE DE FRANCE for static and dynamic analysis of tridimensional structures in areas such as piping, civil engineering or rotating machines. (A.V.I.S. computer code: Analysis and Vibrations of Industrial Structures).

Turnover of sodium in the human hand was studied by neutron activation. Patients suffering from various metabolic abnormalities affecting the skeleton, who were undergoing routine neutron activation for the measurement of calcium, were investigated along with a group of healthy volunteers. Neutron activation labels the sodium atoms simultaneously and with equal probability regardless of the turnover time of individual body compartments. The loss of sodium can be described either by a sum of two exponentials or by a single power function. Distinctions between patients and normal subjects were not apparent from the exponential model but were brought out by the power function. The exponent of time in the latter is a measure of clearance rate. The mean values of this parameter in (a) a group of patients suffering from acromegaly: (b) a group including Paget's disease, osteoporosis, Cushing's disease, and hyperparathyroidism; and (c) a group of healthy subjects, were found to be significantly different from each other.

Our survey of 146 cases of thyroid carcinoma showed the following points: (a) in 20% of the cases the gland was diffusely enlarged without nodules; (b) in 35% of 34 cases, thyroid carcinoma was located in areas other than the "cold" zones; (c) multiple foci of carcinoma were found in 67% of cases with total or subtotal thyroidectomy and in 33% of cases with partial thyroidectomy; (d) anaplastic carcinomas (13% of cases) occurred in patients of all ages, 29% of them in patients younger than 30 years.

Results obtained with Althesin as anaesthetic in 100 patient subjected to urological surgery are presented. The continuous perfusion of Althesin gave a level of stable and flexible anaesthesia that, like the return to consciousness, was particularly appreciated by aged patients. Stress is laid on the fact that the harm caused by volatile anaesthetics is avoided.

One patient was seen with Candida albicans infection in a gastric ulcer. Gastric biopsy was of value in the diagnosis. The patient responded well to Nistatin therapy.

Contributo teso a fornire un sintetico quadro storico-geografico sulla Cina tradizionale, e sull'area dell'antico Distretto di Huizhou

A concise article on the history and geography of China, and on the historical and cultural features of Huizhou District

A description of the importance of landscape in Chinese tradition, from geographical and mythical sources to Daoism, from the concept of "inner landscape" to fengshui and the theory of landscape painting

Viene qui descritto il ruolo e l'importanza del paesaggio nella tradizione cinese in tutti i suoi aspetti: dal simbolismo geografico al paesaggio sacro del Daoismo, dal concetto di paesaggio interiore al fengshui e alle fonti sulla pittura di paesaggio