Weighted inequalities and pointwise estimates for the multilinear fractional integral and maximal operators

In this article we prove weighted norm inequalities and pointwise estimates between the multilinear fractional integral operator and the multilinear fractional maximal. As a consequence of these estimations we obtain weighted weak and strong inequalities for the multilinear fractional integral operator. In particular, we extend some results given in \cite{CPSS} to the multilinear context. On the other hand we prove weighted pointwise estimates between the multilinear fractional maximal operator ${\cal M}_{\alpha,B}$ associated to a Young function $B$ and the multilinear maximal operators ${\cal M}_{\psi}={\cal M}_{0,\psi}$, $\psi(t)=B(t^{1-\alpha/(nm)})^{{nm}/{(nm-\alpha)}}$. As an application of these estimate we obtain a direct proof of the $L^p-L^q$ boundedness results of ${\cal M}_{\alpha,B}$ for the case $B(t)=t$ and $B_k(t)=t(1+\log^+t)^k$ when $1/q=1/p-\alpha/n$. We also give sufficient conditions on the weights involved in the boundedness results of ${\cal M}_{\alpha,B}$ that generalizes those given in \cite{M} for $B(t)=t$. Finally, we prove some boundedness results in Banach function spaces for a generalized version of the multilinear fractional maximal operator

Boundedness of fractional operators in weighted variable exponent spaces with non doubling measures

In the context of variable exponent Lebesgue spaces equipped with a lower Ahlfors measure we obtain weighted norm inequalities over bounded domains for the centered fractional maximal function and the fractional integral operator

End-point estimates for iterated commutators of multilinear singular integrals

Iterated commutators of multilinear Calderon-Zygmund operators and pointwise multiplication with functions in $BMO$ are studied in products of Lebesgue spaces. Both strong type and weak end-point estimates are obtained, including weighted results involving the vectors weights of the multilinear Calderon-Zygmund theory recently introduced in the literature. Some better than expected estimates for certain multilinear operators are presented too.Comment: A typo in the original manuscript lead to overlook a gap in one of our arguments which has been fixed. The new arguments are provided in the proof of Theorem 3.1 in Section 3. With the exception of some new notation introduced and some minor changes in wording in a few places, those new details are the only modifications to the original manuscrip

Emergency nurses’ experiences of the implementation of early goal-directed fluid resuscitation therapy in the management of sepsis

Background: Severe sepsis is a life-threatening condition caused by the body’s overwhelming immune response to an infection. It can lead to organ failure and death if immediate treatment, such as intravenous (IV) fluids and antibiotics, are not commenced within the first hour. While a large number of studies have analysed the administration of first-dose antibiotics, the time-critical initiation of IV fluids has not always been given its deserved priority. To date, studies have not explored factors that inhibit timely IV fluid administration and the experience of emergency nurses relating to initiating early goal-directed fluid resuscitation (EGDFR). Purpose: To explore the experiences of emergency nurses related to initiating EGDFR in the care of patients with sepsis Methods: A qualitative exploratory approach, encompassing face-to-face semi-structured interviews, was used for data collection. Ten registered nurses were interviewed, who were currently practicing in emergency settings across New South Wales (NSW). Braun and Clarke’s (2006) thematic analysis framework guided the data analysis. Findings: Three themes and associated subthemes were identified. The three themes are (i) Nurses’ perceptions and experiences regarding IV fluid administration in sepsis, (ii) Challenges related to initiating IV fluid, and (iii) Strategies to improve compliance with EGDFR. Participants described various factors they found that inhibited timely initiation of IV fluids, including busyness of the department, delayed diagnosis of sepsis, complex patient presentations and limited scope of nurses’ practice to initiate IV fluids. Conclusion: It is anticipated that the outcomes of this research will provide an impetus for re-evaluating current protocol guidelines to provide a positive impact on the scope of emergency nurse practice for initiating EGDFR

Systematic review of the effect of exercise on the reduction of myocardial remodeling following a myocardial infarction compared to a sedentary approach

Background: Cardiovascular disease is one of the leading causes of morbidity and mortality in humans worldwide. Ventricular remodeling following a myocardial infarction leads to detrimental outcomes due to cardiovascular death and ventricular dysfunction. Exercise training is an adjunct strategy to reduce the myocardial remodeling process. Purpose: The paper seeks to answer the following PICO question: P: Population with post- infarct myocardial-remodeling I: Exercise following a myocardial infarction C: Sedentary approach O: Prevention of deleterious myocardial remodeling post-MI Methods: A comprehensive literature review was done using PubMed and Science Direct with articles published in 2019 or after. The search was conducted using the terms: myocardial remodeling exercise, post-infarct ventricular remodeling, post-infarct myocardial remodeling exercise, post-infarct myocardial remodeling, and myocardial remodeling training. Peer- reviewed articles and scholarly journals were included in the search. Conclusions: Studies in which exercise was introduced following a myocardial infarction have demonstrated a reduction in cardiac remodeling and an improvement in overall cardiac function. These findings suggest that an exercise program following a myocardial infarction can benefit patients in reducing negative complications such as cardiac wall thinning, infarct expansion, and heart failure