The COVID-19 pandemic is expected to increase suicidal behavior. However, data available to date are inconsistent. This study examines suicidal thoughts and behaviors and suicide trends in 2020 ...relative to 2019 as an approximation to the impact of the pandemic on suicidal behavior and death in the general population of Catalonia, Spain. Data on suicide-related thoughts and behaviors (STBs) and suicidal mortality were obtained from the Catalonia Suicide Risk Code (CSRC) register and the regional police, respectively. We compared the monthly crude incidence of STBs and suicide mortality rates of 2020 with those of 2019. Joinpoint regression analysis was used to assess changes in trends over time during the studied period. In 2020, 4,263 consultations for STBs and 555 suicide deaths were registered in Catalonia (approx. 7.5 million inhabitants). Compared to 2019, in 2020 STBs rates decreased an average of 6.3% (incidence rate ratio, IRR=0.94, 95% CI 0,90–0,98) and overall suicide death rates increased 1.2% (IRR=1.01, 95% CI 0.90–1.13). Joinpoint regression results showed a substantial decrease in STBs rates with a monthly percent change (MPC) of -22.1 (95% CI: -41.1, 2.9) from January-April 2020, followed by a similar increase from April-July 2020 (MPC=24.7, 95% CI: -5.9, 65.2). The most restrictive measures implemented in response to the COVID-19 pandemic reduced consultations for STBs, suggesting that the “stay at home” message may have discouraged people from contacting mental health services. STBs and mortality should continue to be monitored in 2021 and beyond to understand better the mid-to-long term impact of COVID-19 on suicide trends.
The mechanical properties of cold-drawn pearlitic wires are controlled largely by the microstructure developed during processing and, to some extent, by the residual stresses during drawing. The ...advent of powerful computers and the availability of equipment to perform diffraction experiments, have made possible numerical predictions and accurate measurements of residual stresses. This paper—a review of work done by the author and collaborators—shows how stress-relaxation losses, environmental assisted cracking and fatigue life of cold-drawn pearlitic wires are influenced by residual stresses. The role of pre-stretching loads, or of stress relieving treatments, on stress-relaxation can be understood when the profile of residual stresses is known. Some awkward results in times to fracture during hydrogen embrittlement tests can be explained if accurate values of residual stresses near the surface are known, and the same is true of fatigue life. In this context numerical simulations and measurements performed on cold-drawn pearlitic wires, with different profiles of residual stresses, have shown very good quantitative agreement.
The influence of
aggregate shape on the fracture energy, tensile strength and elasticity modulus in concrete is considered. For this purpose, eight simple cement-based composites were designed, ...manufactured and tested, with two purposes: to provide experimental data that can throw some light on this involved problem and help in the design of future cement-based composites, and supply information that can be used as a benchmark for checking numerical models of concrete failure, as this simple composite is amenable to being modelled quite easily. Thirty-six notched beams were tested and values of the fracture energy and elasticity modulus were recorded. The tensile strength was measured from indirect standard tensile tests. Comparison with available experimental data is also included and discussed. Fracture was modelled using a cohesive crack with a bilinear softening function; data of the softening function inferred from the experimental measurements are also provided and discussed.
The influence of the
aggregate size on the fracture energy, tensile strength and elasticity modulus in different types of concrete are analyzed. For this purpose, nine simple cement-based composites ...have been designed, manufactured and tested, with one objective to provide experimental results that can be used as a benchmark for checking numerical models of concrete fracture, as this simple composite (a matrix, spherical aggregates of the same radius, and two types of matrix–aggregate interface) is amenable to modelling. All in all, 44 specimens were tested. From notched beam tests, values of the fracture energy and modulus of elasticity were obtained. The tensile stress was deduced from indirect standard tensile test. Data for bilinear softening functions extracted from the experimental measurements are also provided. Comparison with available experimental data is also included and discussed.
Introduction
Suicide is a leading cause of preventable death in the world. Interventions that can
quickly reach a large and geographically dispersed population are needed. Web-based programs
are ...potentially cost-effective, allowing continuity of care. The iFightDepression-SURVIVE
(iFD-Survive) is a web-based program designed as an add-on to iFightDepression, a tool
developed by the European Alliance Against Depression to target depressive symptoms
(https://ifightdepression.com/en/). iFD-Survive is based on dialectical behavioral therapy
skills and includes four modules: a safety plan, mindfulness, emotion regulation, and
distress tolerance. The content is presented in various formats, including audio, videos, and
registers. In addition, weekly telephone support is offered by a mental health
nurse.
Objectives
To investigate the feasibility (acceptability, usability, and satisfaction) of the
iFD-Survive.
Methods
30 participants who received the intervention as part of a large RCT completed an
online survey. To receive the intervention, participants needed to meet the following
criteria: 1) digital literacy, 2) having attempted suicide in the last month, and 3) PHQ-9
scores above 5. The online survey included an ad-hoc questionnaire to collect
socio-demographic data and data regarding participants’ opinions on the program’s content.
The following instruments were also administered:
System Usability Scale (SUS)
Credibility of analogue of therapy rationales
Results
Most respondents were women (20/30), with a mean age of 44 years, and secondary
studies (15/30). Most participants (57%) used a mobile phone to access the website and
regarded it as “easy to use” (53%). According to the SUS, many of them (57%) reported that
they would like to use it frequently and that the tool was “easy” and “safe” to use (53%).
Regarding acceptability, 47% of the sample indicated that the iFD-Survive content was
adequate to improve their symptoms, and 56% considered that their symptoms of depression have
improved as a result of the intervention. 83% of the sample considered telephone follow-up
“very useful.” The majority (70%) consulted the program once a week. The “safety plan” and
the mindfulness module were regarded as the most useful, followed by “distress tolerance.”
The audio for practicing mindfulness skills and the written material were considered very
useful, while the videos were valuable.
Conclusions
Online tools can promote continuity of care, helping to prevent further suicide
attempts in vulnerable populations. These preliminary findings suggest that the iFD-Survive
is feasible among participants with depressive symptoms who have recently attempted suicide.
However, these results are based on a small sample of highly educated women; therefore,
future research is needed to determine if these can be transferred to other
sub-populations.
Disclosure of Interest
None Declared
► Seventy new tests on notched specimens made of polymethyl-methacrylate are summarised. ► The tests are carried out at room temperature under torsion loading. ► In all cases static failure occurs ...under large scale yielding conditions. ► Such results can help in evaluating theoretical models of the fracture under mode III loading. ► A non-conventional application of the strain energy density is carried out.
The first part of the paper gives an account of more than 70 new fracture tests on notched specimens made of polymethyl-methacrylate. All static tests are carried out at room temperature under torsion loading conditions. Semi-circular notches as well as U- and V-notches (with an opening angle equal to 120°) are considered, with a root radius ranging from 0.1 to 7.0mm. Plots of torque loads versus twist angles are recorded varying the notch root radius and the notch depth. In all cases static failure occurs under large scale yielding conditions. Such results can help in evaluating numerical and theoretical models of the fracture of notched components under mode III loading.
The second part of the paper deals with a discussion on the experimental results and different approaches are applied to the new data. The notched specimens during the torsion tests present a substantial plastic behaviour and the influence of the effective resistant net area is found to be the predominant parameter with respect to the notch shape (i.e. notch opening angle and tip radius). A non-conventional application of the strain energy density is carried out showing a good agreement between experimental results and theoretical fracture assessments and it is used to justify the link between nominal and local fracture approaches.
ABSTRACT
A large bulk of static test results carried out on notched specimens are presented in a unified way by using the mean value of the strain energy density (SED) over a given finite‐size volume ...surrounding the highly stressed regions. In plane problems, when cracks or pointed V‐notches are considered, the volume becomes a circle or a circular sector, respectively, with RC being the radius. RC depends on the fracture toughness of the material, the ultimate tensile strength and the Poisson's ratio. When the notch is blunt, the control area assumes a crescent shape and RC is its width as measured along the notch bisector.
About 900 experimental data, taken from recent literature, are involved in the local SED‐based synthesis. They have been obtained from (a) U‐ and V‐notched specimens made of different materials tested under mode I loading; (b) U‐ and V‐notched specimens made of polymethyl‐metacrylate (PMMA) and an acrylic resin, respectively, tested in mixed, I + II, mode; (c) U‐notched specimens made of ceramics materials tested under mode I.
The local SED values are normalized to the critical SED values (as determined from unnotched specimens) and plotted as a function of the R/RC ratio. A scatter band is obtained whose mean value does not depend on R/RC, whereas the ratio between the upper and the lower limits are found to be about equal to 1.6. The strong variability of the non‐dimensional radius R/RC (ranging here from about zero to around 1000) makes stringent the check of the approach based on the mean value of the local SED on a material‐dependent control volume.
This article explores the capability of the Cohesive Zone Model in predicting the critical load of blunt notched specimens made of coarse‐grained polycrystalline graphite, a brittle material that has ...gained the attention of researchers because of its favourable properties for protection against thermal loads. To that aim, 39 different tests on U‐notched and V‐notched specimens made of this material, with loading modes raging from mode I to mixed mode I/II, have been modelled by using the Cohesive Zone Model. The model has been implemented through the embedded crack approach, avoiding thus the necessity of defining the crack trajectory prior to the simulation because it is automatically generated once the maximum principal stress overcomes the tensile strength of the material. The numerical predictions obtained show good agreement with the experimental results.
The extraordinary mechanical performance of spider dragline silk is explained by its highly ordered microstructure and results from the sequences of its constituent proteins. This optimized ...microstructural organization simultaneously achieves high tensile strength and strain at breaking by taking advantage of weak molecular interactions. However, elucidating how the original design evolved over the 400 million year history of spider silk, and identifying the basic relationships between microstructural details and performance have proven difficult tasks. Here we show that the analysis of maximum supercontracted single spider silk fibers using X ray diffraction shows a complex picture of silk evolution where some key microstructural features are conserved phylogenetically while others show substantial variation even among closely related species. This new understanding helps elucidate which microstructural features need to be copied in order to produce the next generation of biomimetic silk fibers.
To investigate the response to therapy of entheseal abnormalities assessed with power Doppler (PD) ultrasound (US) in spondyloarthropathies (SpA).
A total of 327 patients with active SpA who were ...starting anti-tumor necrosis factor (TNF) therapy were prospectively recruited at 35 Spanish centers. A PDUS examination of 14 peripheral entheses was performed by the same investigator in each center at baseline and at 6 months. The following elementary lesions were assessed at each enthesis (presence/absence): morphologic abnormalities (hypoechogenicity and/or thickening), entheseal calcific deposits, cortical abnormalities (bone erosion and/or proliferation), adjacent bursitis and intraenthesis and perienthesis (tendon body and/or bursa) PD signal. Response to therapy of each elementary lesion was assessed by calculating change in the cumulative presence from baseline to 6 months. Intraobserver reliability of PDUS was evaluated by blindly assessing the stored baseline images 3 months after the real-time examination.
Complete data were obtained on 197 patients who received anti-TNF therapy for 6 months. In 91.4% of the patients there were gray-scale or PD elementary lesions at baseline and at 6 months. Cumulative entheseal morphologic abnormalities, intraenthesis PD, perienthesis PD, and bursitis showed a significant decrease from baseline to 6 months (p < 0.05). There was high intraobserver reliability for all elementary lesions (interclass correlation coefficient > 0.90, p < 0.0005).
Entheseal morphologic abnormalities, PD signal, and bursitis were US abnormalities that were responsive to anti-TNF therapy in SpA. PDUS can be a reproducible method for multicenter monitoring of therapeutic response in enthesitis of SpA.
PDF
