49 research outputs found
Existence and multiplicity of solutions for Dirichlet problems involving nonlinearities with arbitrary growth.
In this article we study the existence and multiplicity of solutions for the Dirichlet problem
\displaylines{ -\Delta_p u=\lambda f(x,u)+ \mu g(x,u)\quad\hbox{in }\Omega,\cr
u=0\quad\hbox{on } \partial \Omega}
where is a bounded domain in , are Caratheodory functions, and are nonnegative parameters. We impose no growth condition at on the nonlinearities f,g. A corollary to our main result improves an existence result recently obtained by Bonanno via a critical point theorem for functionals which do not satisfy the usual sequential weak lower semicontinuity property
Analysis of Bacterial Stent Colonization: The Role of Urine and Device Microbiological Cultures
: In this study, we explored the incidence of double J (JJ) contamination of patients who underwent an endourological procedure for urinary stones and ureteral stenosis. We developed a prospective study between January 2019 and December 2021. Ninety-seven patients, 54 male and 43 female, were enrolled. Urine culture was taken during four steps: before stent insertion, a sample from selective renal pelvis catheterization, a sample two days after the JJ insertion and finally, after the stent removal procedure. At the time of the stent removal, 1 cm of proximal and distal ends were cut off and placed in the culture for bacterial evaluation. Cohen's kappa coefficient value (k) and concordance rates of microbiological culture results were evaluated. The study group comprised 56% of male patients. Proximal and distal stent cultures were positive in 81 and 78 patients. The concordance rate of microbiological cultures between proximal and distal double J stent is 88% (k 0.6). The most common pathogens isolated from urine and stent cultures were Enterococcus spp. in 52 cases and Klebsiella spp. in 27 cases
A cardinal role for cathepsin D in co-ordinating the host-mediated apoptosis of macrophages and killing of pneumococci
The bactericidal function of macrophages against pneumococci is enhanced by their apoptotic demise, which is controlled by the anti-apoptotic protein Mcl-1. Here, we show that lysosomal membrane permeabilization (LMP) and cytosolic translocation of activated cathepsin D occur prior to activation of a mitochondrial pathway of macrophage apoptosis. Pharmacological inhibition or knockout of cathepsin D during pneumococcal infection blocked macrophage apoptosis. As a result of cathepsin D activation, Mcl-1 interacted with its ubiquitin ligase Mule and expression declined. Inhibition of cathepsin D had no effect on early bacterial killing but inhibited the late phase of apoptosis-associated killing of pneumococci in vitro. Mice bearing a cathepsin D-/- hematopoietic system demonstrated reduced macrophage apoptosis in vivo, with decreased clearance of pneumococci and enhanced recruitment of neutrophils to control pulmonary infection. These findings establish an unexpected role for a cathepsin D-mediated lysosomal pathway of apoptosis in pulmonary host defense and underscore the importance of apoptosis-associated microbial killing to macrophage function
Stool Xpert MTB/RIF as a possible diagnostic alternative to sputum in Africa: a systematic review and meta-analysis
Introduction: Worldwide, COVID-19 pandemic lead to a large fall in the number of newly reported TB cases. In sub-Saharan Africa, microbiological diagnosis of TB is generally based on smear microscopy and Xpert MTB/RIF on sputum samples, but good quality sputum samples are often difficult to obtain, leading clinicians to rely on more invasive procedures for diagnosis. Aim of this study was to investigate pooled sensitivity and specificity of Xpert MTB/RIF on stool samples compared to respiratory microbiological reference standards in African countries. Methods: Four investigators independently searched PubMed, SCOPUS, and Web of Science until 12th October 2022, then screened titles and abstracts of all potentially eligible articles. The authors applied the eligibility criteria, considered the full texts. All the studies reported the data regarding true positive (TP), true negative (TN), false positive (FP) and false negative (FN). Risk of bias and applicability concerns were assessed with the Quadas-2 tool. Results: overall, among 130 papers initially screened, we evaluated 47 works, finally including 13 papers for a total of 2,352 participants, mainly children. The mean percentage of females was 49.6%, whilst the mean percentage of patients reporting HIV was 27.7%. Pooled sensitivity for Xpert MTB/RIF assay for detecting pulmonary tuberculosis was 68.2% (95%CI: 61.1–74.7%) even if characterized by a high heterogeneity (I2=53.7%). Specificity was almost 100% (99%, 95%CI: 97–100%; I2 = 45.7%). When divided for reference standard, in the six studies using sputum and nasogastric aspirate the accuracy was optimal (AUC = 0.99, SE = 0.02), whilst in the studies using only sputum for tuberculosis detection the AUC was 0.85 (with a SE = 0.16). The most common source of bias was exclusion of enrolled patients in the analysis. Conclusions: Our study confirms that, in Africa, stool Xpert MTB/RIF may be a useful rule-in test for children above and below 5 years of age under evaluation for pulmonary tuberculosis. Sensitivity increased substantially when using both sputum and nasogastric aspirate as reference samples
On the Almost Everywhere Convergence of Multiple Fourier-Haar Series
The paper deals with the question of convergence of multiple Fourier-Haar series with partial sums taken over homothetic copies of a given convex bounded set W⊂R+n containing the intersection of some neighborhood of the origin with R+n. It is proved that for this type sets W with symmetric structure it is guaranteed almost everywhere convergence of Fourier-Haar series of any function from the class L(ln+L)n−1
On the possible values of upper and lower derivatives with respect to differentiation bases of product structure.
A solution of the Guzm\ue1n's problem on possible values of upper and lower derivatives
is given for the class of translation invariant and product type differentiation bases formed by ndimensional
intervals. Namely, the bases from the mentioned class are characterized, for which
integral means of a summable function can boundedly diverge only on a set of zero measur
An existence result for fractional kirchhoff-type equations
none2noThe aim of this paper is to study a class of nonlocal fractional Laplacian equations of Kirchhoff-type. More precisely, by using an appropriate analytical context on fractional Sobolev spaces, we establish the existence of one non-trivial weak solution for nonlocal fractional problems exploiting suitable variational methods.mixedMolica Bisci G; Tulone F.Molica Bisci, G; Tulone, F
Turbidity analysis in Sicilian coastal zones by means of remote sensing images and spectroradiometric measurements
Water turbidity has a wide range of variability both spatially and temporally. Rivers transport sediments to the river mouth following a seasonal behaviour and occasionally during flood events (Doxaran et al., 2006; Pribble et al., 2001). Once in the sea, sediments are spatially driven by currents, and re-suspended by waves from the bottom, changing water turbidity in the tidal and sub-tidal zones (Cloern et al., 1989; Uncles et al., 2002; Wolanski & Spagnol, 2003). Moreover human activities such as transport and dredging occasionally and locally influence turbidity magnitude and distribution (Schoellhamer, 1996).
In recent years the pollution of the maritime environment suggests that only operational monitoring activities can improve the preservation of this vulnerable and valuable ecosystem. Furthermore, these practices can aid the understanding of the anthropic impact on the maritime ecosystem. Within this framework, monitoring the spatial-temporal distribution of coastal water quality parameters plays a fundamental role. To this aim remote sensing techniques represent a suitable tool for water quality assessment, and for continuous monitoring of the Sicilian coastal waters. A chain of automatic processes has been developed in order to assess the Nephelometric Turbidity (NT). An algorithm has be calibrated using in situ data, obtained by intensive field campaigns undertaken in the three Sicilian gulfs (Castellammare, Augusta and Gela gulfs) during three periods in 2008 (at the beginning of July, August and September for each gulf)