Near-Extremal Limits of de Sitter Black Holes

We analyze the thermodynamic response near extremality of charged black holes in four-dimensional Einstein-Maxwell theory with a positive cosmological constant. The latter exhibit three different extremal limits, dubbed cold, Nariai and ultracold configurations, with near-horizon geometries AdS$_2 \times S^2$, dS$_2 \times S^2$, Mink$_2 \times S^2$, respectively. For each of these three cases we analyze small deformations away from extremality, and contrast their response. We also construct the effective two-dimensional theory, obtained by dimensional reduction, that captures these features and we provide a more detailed analysis of the perturbations around the near-horizon geometry for each case. Our results for the ultracold case in particular show an interesting interplay between the entropy variation and charge variation, realizing a different symmetry breaking with respect to the other two near-extremal limits.Comment: 32 pages, 2 figures; v3: typos fixed, clarifications on branches of 2D solutions added, comments on metric backreaction in sec. 4.2 removed. Section with outlook and conclusions adde

La kV Cone Beam CT (kV-CBCT) in radioterapia guidata dalle immagini (IGRT): misure di dose e ottimizzazione di un protocollo di acquisizione clinico

Scopo: Il presente lavoro di tesi, svolto presso le Unità Operative di Radioterapia e di Fisica Sanitaria dell’Ospedale Bellaria di Bologna, si pone l’obiettivo di valutare la dose erogata al paziente in seguito all’acquisizione di immagini CT volumetriche prima del trattamento radiante. Inoltre, si presenta una procedura per ottimizzare la dose dovuta a tali procedure di imaging. Materiali e Metodi: Si è misurato il parametro “CTDI” (Computed Tomography Dose Index) quale indice dosimetrico correlato alla dose assorbita dal paziente sottoposto a kV-CBCT. Le misure sono state effettuate con una camera a ionizzazione di tipo “pencil”, lunga 10 cm, in un apposito fantoccio in polimetil-metacrilato avente 5 alloggiamenti per la camera a ionizzazione (4 in periferia e 1 al centro). Sono state effettuate misure di dose sia per i protocolli di acquisizione di immagini di kV-CBCT (“preset”) forniti dalla casa costruttrice, sia per quelli modificati, per diverse esigenze cliniche, dall’utente. Infine, allo scopo di ottimizzare la dose dovuta alla kV-CBCT, si è agito sul parametro radiologico dei mAs/frame, abbassando tale valore fino al punto oltre il quale un ulteriore abbassamento avrebbe causato un detrimento della qualità di immagine, non più accettabile dal punto di vista clinico. Risultati: Nel lavoro, sono state effettuate e presentate circa 90 misure sperimentali di CTDI. I risultati relativi alle misure dei preset clinici di fabbrica hanno confermato i valori dichiarati dal costruttore. Un preset clinico utilizzato frequentemente nella pratica clinica è stato ottimizzato, riducendone la dose erogata al paziente del 20%. Conclusioni: In questo lavoro di tesi sono state effettuate misure di dose in kV-CBCT sia per preset di acquisizione forniti dalla ditta costruttrice sia per i protocolli personalizzati dall’utente. Per il preset ottimizzato, è stato raggiuto un buon compromesso tra il risparmio di dose erogata al paziente e la qualità dell’immagine ottenuta

Trattamento chirurgico dell'incontinenza urinaria da sforzo nel maschio:relazione tra posizione dello sling transotturatorio valutata con RMN 3T e risultati clinici.

Retrourethral transobturator sling is a new functional treatment of stress urinary incontinence after prostatectomy with reported success rate of 54 to 80% and a failure rate of 20 to 45%. Objective: Aim of the study was to retrospectively analyze morphologic changes visible on MRI after sling procedure in continent patients compared with the incontinent ones, in order to detect possible factors explaining the different clinicoutcomes. Design, Setting, and Participants: 21 male patients treated with the Advance ® sling, were enrolled: 13/21 had clinical recovery, while 8/21 had persistent incontinence. The procedure outcome was defined as cured patients (0 - 1 security pad) or incontinent ones (>2 pads). The MRI protocol performed with a 3 T system included: 3D T2w sequence (CUBE) and a high temporal resolution Fiesta for dynamic sequence. On the T2w sequence, we measured the length of the urethral bulb posterior to the sling (LB) and the distance of the sling from a line bisecting the pubic symphysis (LBPS). The bladder neck activity was evaluated with dynamic sequence. Results were analyzed with two-tailed Mann-Whitney test. Results and Limitations: In the 8 incontinent patients the length of the urethral bulb posterior to the sling was 10mm (range 10-28mm) (p<0.0002). The sling was located posterior to the LBPS in 7/8 incontinent patients (4.4-12.6mm) and almost coincident with it in 8/13 continent patients (p=0.0549). On the dynamic study, during the Valsalva manoeuvre all incontinent patients showed urine leakage. Conclusions: The failure of RTS, still poorly understood, can be related to inappropriate indications; based on our results, an incorrect sling placement seems to be another cause of failure. In particular, the LB posterior to the sling seems to be strongly correlated with continence

Endoluminal calprotectin measurement in assessment of pouchitis and a new index of disease activity. A pilot study

Pouchitis is the most common complication following proctocolectomy with ileal pouch-anal anastomosis for ulcerative colitis (UC). To provide a standardized definition of pouchitis clinical, endoscopic and histological markers were grouped and weighted in the pouch disease activity index (PDAI). However, the delay in the assessment of the final score due to the time requested for histological analysis remains the main obstacle to the index implementation in clinical practice so that the use of modified-PDAI (mPDAI) with exclusion of histologic subscore has been proposed. We tested the ability of calprotectin measurement in the pouch endoluminal content to mimic the histologic score as defined in the PDAI, the index that we adopted as gold standard for pouchitis diagnosis. Calprotectin was measured by ELISA in the pouch endoluminal content collected during endoscopy in 40 consecutive patients with J-pouch. In each patient PDAI and mPDAI were calculated and 15% of patients were erroneously classified by mPDAI. ROC analysis of calprotectin values vs. acute histological subscore 3 identified different calprotectin cut-off values with corresponding sensitivity and specificity allowing the definition and scoring of different range of calprotectin subscores. We incorporated the calprotectin score in the mPDAI obtaining a new score that shows the same specificity as PDAI for diagnosis of pouchitis and higher sensitivity when compared with mPDAI. The use of the proposed new score, once validated in a larger series of patients, might be useful in the early management of patients with symptoms of pouchitis

Defective FoxP3+ Treg cell differentiation in the gut of Type 1 Diabetic patients

Environmental factors that act at the intestinal level such as diet, drugs, and microflora have a high impact on the pathogenesis of autoimmune Type 1 Diabetes (T1D), but it is still unclear how the gut milieu affects autoimmunity outside the intestine. Here we show that peripheral FoxP3+ Treg cell differentiation, a mechanism that takes place in the gut and is crucial to maintain systemic immune tolerance, is impaired in T1D patients. These results provide the first evidence that gut mucosa alteration could predispose to autoimmune T1D by affecting systemic immune regulation

Colonization by Escherichia coli strains with increased minimal inhibitory concentration for cefiderocol: When resistance anticipates drug use.

n/

Enhancing walking efficiency of adolescents with neurological impairments using an exosuit for ambulatory activities of daily living

INTRODUCTION: Children and adolescents with neurological impairments face reduced participation and independence in daily life activities due to walking difficulties. Existing assistive devices often offer insufficient support, potentially leading to wheelchair dependence and limiting physical activity and daily life engagement. Mobile wearable robots, such as exoskeletons and exosuits, have shown promise in supporting adults during activities of daily living but are underexplored for children. METHODS: We conducted a cross-sectional study to examine the potential of a cable-driven exosuit, the Myosuit, to enhance walking efficiency in adolescents with diverse ambulatory impairments. Each participant walked a course including up-hill, down-hill, level ground walking, and stairs ascending and descending, with and without the exosuit's assistance. We monitored the time and step count to complete the course and the average heart rate and muscle activity. Additionally, we assessed the adolescents' perspective on the exosuit's utility using a visual analog scale. RESULTS: Six adolescents completed the study. Although not statistically significant, five participants completed the course with the exosuit's assistance in reduced time (time reduction range: [-3.87, 17.42]%, p-value: 0.08, effect size: 0.88). The number of steps taken decreased significantly with the Myosuit's assistance (steps reduction range: [1.07, 15.71]%, p-value: 0.04, effect size: 0.90). Heart rate and muscle activity did not differ between Myosuit-assisted and unassisted conditions (p-value: 0.96 and 0.35, effect size: 0.02 and 0.42, respectively). Participants generally perceived reduced effort and increased safety with the Myosuit's assistance, especially during tasks involving concentric contractions (e.g., walking uphill). Three participants expressed a willingness to use the Myosuit in daily life, while the others found it heavy or too conspicuous. DISCUSSION: Increased walking speed without increasing physical effort when performing activities of daily living could lead to higher levels of participation and increased functional independence. Despite perceiving the benefits introduced by the exosuit's assistance, adolescents reported the need for further modification of the device design before using it extensively at home and in the community