Histoire d’eau : le tolvaptan dans tous ses états [Clinical use of tolvaptan: a 2021 review]

Along with the arrival of the first vasopressin-receptor V2R inhibitor, the indications for its use have increased. We review here and focus on polycystic kidney disease (PKD) and hyponatremia. Tolvaptan is the first drug available to slow down the progression of PKD in patients with rapid progressing disease. However, the benefits are moderate and the side effects are important, making important to share the decision of treatment together with the patient. Hyponatremia with preserved extra-cellular volume or associated with edema may be reversed by tolvaptan. Patients with SIADH or hyponatremia and edema might benefit from this treatment under strict monitoring. Overall, vaptans are helpful in several conditions, but remain tools that must be used under close control

Transcutaneous flow related variables measured in vivo: the effects of gender

BACKGOUND: The identification of potential sources of error is a crucial step for any new assessment technique. This is the case for transcutaneous variables, such as flow and arterial gases, which have been applied as functional indicators of various aspects of human health. Regarding gender, a particular subject-related determinant, it is often claimed that women present higher transcutaneous oxygen pressure (tcpO(2)) values than men. However, the statistical significance of this finding is still uncertain. METHODS: The haemodynamical-vascular response to a local reactive hyperaemia procedure (the tourniquet cuff manoeuvre) was studied in two previously selected group of volunteers (n = 16; 8 women and 8 men). The effect of gender was assessed under standardised experimental conditions, using the transcutaneous flow-related variables tcpO(2)-tcpCO(2) and Laser-doppler Flowmetry (LDF). RESULTS: Regarding tcpO(2), statistically significant differences between genders were not found, although higher values were consistently found for the gases in the female group. Regarding LDF, high statistically significant differences (p < 0.005) were found, with the men's group presenting the highest values and variability. Other derived parameters used to characterise the vascular response following the cuff-deflation (t-peak) were similar in both groups. CONCLUSIONS: The relative influence of gender was not clearly demonstrated using these experimental conditions. However the gender-related LDF differences suggest that further investigation should be done on this issue. Perhaps in the presence of certain pathological disparities involving peripheral vascular regulation, other relationships may be found between these variables

Joint effects of intensity and duration of cigarette smoking on the risk of head and neck cancer: A bivariate spline model approach

Objectives: This study aimed at re-evaluating the strength and shape of the dose-response relationship between the combined (or joint) effect of intensity and duration of cigarette smoking and the risk of head and neck cancer (HNC). We explored this issue considering bivariate spline models, where smoking intensity and duration were treated as interacting continuous exposures. Materials and Methods: We pooled individual-level data from 33 case-control studies (18,260 HNC cases and 29,844 controls) participating in the International Head and Neck Cancer Epidemiology (INHANCE) consortium. In bivariate regression spline models, exposures to cigarette smoking intensity and duration (compared with never smokers) were modeled as a linear piecewise function within a logistic regression also including potential confounders. We jointly estimated the optimal knot locations and regression parameters within the Bayesian framework. Results: For oral-cavity/pharyngeal (OCP) cancers, an odds ratio (OR) &gt;5 was reached after 30 years in current smokers of ∼20 or more cigarettes/day. Patterns of OCP cancer risk in current smokers differed across strata of alcohol intensity. For laryngeal cancer, ORs &gt;20 were found for current smokers of ≥20 cigarettes/day for ≥30 years. In former smokers who quit ≥10 years ago, the ORs were approximately halved for OCP cancers, and ∼1/3 for laryngeal cancer, as compared to the same levels of intensity and duration in current smokers. Conclusion: Referring to bivariate spline models, this study better quantified the joint effect of intensity and duration of cigarette smoking on HNC risk, further stressing the need of smoking cessation policies

Minimizing defects between adjacent foils in ultrasonically consolidated parts

Two types of defects normally occur in ultrasonically consolidated parts: (i) Defects that occur between mating foils in successive layers ( type 1 defects) and (ii) defects that occur within a layer between two foils laid side-by-side ( type 2 defects). While some success has been achieved in minimizing type 1 defects, type 2 defects, however, have been given very little attention. Both types of defects are undesirable and should be minimized if ultrasonically consolidated parts are to be used in structural applications. This work describes an investigation of how to minimize type 2 defects in ultrasonically consolidated parts. According to our hypothesis, a foil being deposited must overlap the adjacent deposited foil by an optimum amount to ensure a defect-free joint between the two foils. Transverse tensile specimens were fabricated with various amounts of foil overlap (by changing the foil width setting) to test this hypothesis. Metallographic and fractographic studies showed a clear correlation between foil overlap, defect incidence, and tensile strength. It was found that a foil width setting of 23.81 mm helps minimize type 2 defects in ultrasonically consolidated Al 3003 parts using standard foils of 23.88 mm (equivalent to 0.94 in.) nominal width. © 2010 by ASME

Design for Additively Manufactured Lightweight Structure: A Perspective

The design of lightweight structures realized via additive manufacturing has been drawing considerable amount of attentions in academia and industries for a wide range of applications. However, various challenges remain for AM lightweight structures to be reliably used for these applications. For example, despite extensive advancement with geometric design, there still lacks adequate understanding with the process-material property relationship of AM lightweight structures. In addition, a more integrated design approach must also be adopted in order to take non-uniform material design into consideration. In our works, a design approach based on unit cell cellular structure was taken in the attempt to establish a comprehensive design methodology for lightweight structures. Analytical cellular models were established to provide computationally efficient property estimation, and various design factors such as size effect, stress concentration and joint angle effect were also investigated in order to provide additional design guidelines. In addition, it was also found that the geometry and microstructure of the cellular structures are dependent on both the process setup and the feature dimensions, which strongly support the argument to establish a multi-scale hierarchical cellular design tool