scholarly journals Comprehensive Survey of Seismic Hazard at Geothermal Sites by a Meta-Analysis of the Underground Feedback Activation Parameter afb

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7998
Author(s):  
Arnaud Mignan ◽  
Marco Broccardo ◽  
Ziqi Wang

Global efforts to tame CO2 emissions include the use of renewable energy sources, such as geo-energy harnessing. However, injecting pressurised fluids into the deep underground can induce earthquakes, hence converting CO2-related risk into seismic risk. Induced seismicity hazard is characterised by the overall seismic activity afb that is normalised by the injected fluid volume V and the parameter b of the Gutenberg–Richter law. The (afb,b) set has so far been estimated for a dozen of reservoir stimulations, while at least 53 geothermal fluid stimulations are known to exist, based on our survey. Here, we mined the induced seismicity literature and were able to increase the number of estimates to 39 after calculating afb from related published parameters and by imputing b with its expectation where this parameter was missing (0.65 ≤ b ≤ 2.9, with mean 1.16). Our approach was a two-step procedure: we first reviewed the entire literature to identify seismic hazard information gaps and then did a meta-analysis to fill those gaps. We find that the mean and median afb estimates slightly decrease from afb ≈ −2.2 to afb = −2.9 and −2.4, respectively, and that the range of observations expands from −4.2 ≤ afb ≤ 0.4 to −8.9 ≤ afb ≤ 0.4, based on a comprehensive review unbiased towards high-seismicity experiments. Correcting for potential ambiguities in published parameters could further expand the range of possibilities but keep the mean and the median relatively close to original estimates, with afb ≈ −2.3 and −2.4, respectively. In terms of the number of earthquakes induced (function of 10afb), our meta-analysis suggests that it is about half the number that could previously be inferred from published afb estimates (i.e., half the seismic hazard). These results are hampered by high uncertainties, demonstrating the need to re-analyse past earthquake catalogues to remove any ambiguity and to systematically compute afb in future geothermal projects to reduce uncertainty in induced seismicity hazard assessment. Such uncertainties are so far detrimental to the further development of the technology.

2020 ◽  
Vol 228 (1) ◽  
pp. 14-24 ◽  
Author(s):  
Tanja Burgard ◽  
Michael Bošnjak ◽  
Nadine Wedderhoff

Abstract. A meta-analysis was performed to determine whether response rates to online psychology surveys have decreased over time and the effect of specific design characteristics (contact mode, burden of participation, and incentives) on response rates. The meta-analysis is restricted to samples of adults with depression or general anxiety disorder. Time and study design effects are tested using mixed-effects meta-regressions as implemented in the metafor package in R. The mean response rate of the 20 studies fulfilling our meta-analytic inclusion criteria is approximately 43%. Response rates are lower in more recently conducted surveys and in surveys employing longer questionnaires. Furthermore, we found that personal invitations, for example, via telephone or face-to-face contacts, yielded higher response rates compared to e-mail invitations. As predicted by sensitivity reinforcement theory, no effect of incentives on survey participation in this specific group (scoring high on neuroticism) could be observed.


1995 ◽  
Vol 74 (04) ◽  
pp. 1064-1070 ◽  
Author(s):  
Marco Cattaneo ◽  
Alan S Harris ◽  
Ulf Strömberg ◽  
Pier Mannuccio Mannucci

SummaryThe effect of desmopressin (DDAVP) on reducing postoperative blood loss after cardiac surgery has been studied in several randomized clinical trials, with conflicting outcomes. Since most trials had insufficient statistical power to detect true differences in blood loss, we performed a meta-analysis of data from relevant studies. Seventeen randomized, double-blind, placebo-controlled trials were analyzed, which included 1171 patients undergoing cardiac surgery for various indications; 579 of them were treated with desmopressin and 592 with placebo. Efficacy parameters were blood loss volumes and transfusion requirements. Desmopressin significantly reduced postoperative blood loss by 9%, but had no statistically significant effect on transfusion requirements. A subanalysis revealed that desmopressin had no protective effects in trials in which the mean blood loss in placebo-treated patients fell in the lower and middle thirds of distribution of blood losses (687-1108 ml/24 h). In contrast, in trials in which the mean blood loss in placebo-treated patients fell in the upper third of distribution (>1109 ml/24 h), desmopressin significantly decreased postoperative blood loss by 34%. Insufficient data were available to perform a sub-analysis on transfusion requirements. Therefore, desmopressin significantly reduces blood loss only in cardiac operations which induce excessive blood loss. Further studies are called to validate the results of this meta-analysis and to identify predictors of excessive blood loss after cardiac surgery.


2021 ◽  
pp. 219256822097914
Author(s):  
Lei Zhu ◽  
Jun-Wu Wang ◽  
Liang Zhang ◽  
Xin-Min Feng

Study Design: A systematic review and meta-analysis. Objectives: To evaluate clinical and radiographic outcomes, and perioperative complications of oblique lateral interbody fusion (OLIF) for adult spinal deformity (ASD). Methods: We performed a systematic review and meta-analysis of related studies reporting outcomes of OLIF for ASD. The clinical outcomes were assessed by visual analogue scale (VAS) and Oswestry Disability Index (ODI). The radiographic parameters were evaluated by sagittal vertical axis (SVA), pelvic tilt (PT), sacral slope (SS), thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence-lumbar lordosis (PI-LL), Cobb angle and fusion rate. A random effects model and 95% confidence intervals (CI) were performed to investigate the results. Results: A total of 16 studies involving 519 patients were included in the present study. The mean difference of VAS-back score, VAS-leg score and ODI score before and after surgery was 5.1, 5.0 and 32.3 respectively. The mean correction of LL was 20.6°, with an average of 6.9° per level and the mean correction of Cobb was 16.4°, with an average of 4.7° per level. The mean correction of SVA, PT, SS, TK and PI-LL was 59.3 mm, 11.7°, 6.9°, 9.4° and 20.6° respectively. The mean fusion rate was 94.1%. The incidence of intraoperative and postoperative complications was 4.9% and 29.6% respectively. Conclusions: OLIF is an effective and safe surgery method in the treatment of mild or moderate ASD and it has advantages in less intraoperative blood loss and lower perioperative complications.


2021 ◽  
Vol 11 (15) ◽  
pp. 6853
Author(s):  
Filippo Migliorini ◽  
Lucio Cipollaro ◽  
Francesco Cuozzo ◽  
Francesco Oliva ◽  
Andrea Valerio Marino ◽  
...  

Introduction: Outpatient total hip arthroplasty (THA) is increasingly popular. This meta-analysis investigated the potential advantages of outpatient regimes for THA. Methods: This study followed the PRISMA guidelines. PubMed, Web of Science, Google Scholar, Embase, and Scopus databases were accessed in June 2021. All clinical studies investigating outpatient THA were considered. The outcomes of interest were pain, infection, mortality, revision, dislocation, readmission rates, and deep vein thrombosis (DVT). Results: Data from 102,839 patients were included. A total of 52% (153,168 of 102,839 patients) were women. The mean age of patients was 62.6 ± 4.6 years, the mean BMI was 29.1 ± 1.8 kg/m2. Good comparability was found in age, BMI, and gender (p > 0.1). No difference was found in pain (p = 0.4), infections (p = 0.9), mortality (p = 0.9), rate of revision (p = 0.1), dislocation (p = 0.9), and readmission (p = 0.8). The outpatient group demonstrated a greater rate of DVT (OR 3.57; 95% CI 2.47 to 5.18; p < 0.0001). Conclusions: In selected patients, outpatient THA can be performed safely with optimal outcomes comparable with inpatient THA. Clear and comprehensive pre-operative planning should involve a multi-disciplinary group composed of orthopaedic surgeons, anaesthesia and rehabilitation specialists, and physiotherapists. Each centre performing outpatient THA should implement continuous homecoming welfare activity, to supervise physiotherapy and monitor anticoagulant therapy.


Author(s):  
Daniele Piovani ◽  
Claudia Pansieri ◽  
Soumya R R Kotha ◽  
Amanda C Piazza ◽  
Celia-Louise Comberg ◽  
...  

Abstract Background and aims The association between smoking and inflammatory bowel disease (IBD) relies on old meta-analyses including exclusively non-Jewish White populations. Uncertainty persists regarding the role of smoking in other ethnicities. Methods We systematically searched Medline/PubMed, Embase and Scopus for studies examining tobacco smoking and the risk of developing IBD, i.e., Crohn’s disease (CD) or ulcerative colitis (UC). Two authors independently extracted study data and assessed each study’s risk-of-bias. We examined heterogeneity and small-study effect, and calculated summary estimates using random-effects models. Stratified analyses and meta-regression were employed to study the association between study-level characteristics and effect estimates. The strength of epidemiological evidence was assessed through prespecified criteria. Results We synthesized 57 studies examining the smoking-related risk of developing CD and UC. Non-Jewish White smokers were at increased risk of CD (29 studies; RR: 1.95, 95% CI: 1.69‒2.24; moderate evidence). No association was observed in Asian, Jewish and Latin-American populations (11 studies; RR: 0.97; 95% CI: 0.83–1.13), with no evidence of heterogeneity across these ethnicities. Smokers were at reduced risk of UC (51 studies; RR: 0.55, 95% CI: 0.48–0.64; weak evidence) irrespectively of ethnicity; however, cohort studies, large studies and those recently published showed attenuated associations. Conclusions This meta-analysis did not identify any increased risk of CD in smokers in ethnicities other than non-Jewish Whites, and confirmed the protective effect of smoking on UC occurrence. Future research should characterize the genetic background of CD patients across different ethnicities to improve our understanding on the role of smoking in CD pathogenesis.


2021 ◽  
Vol 10 (4) ◽  
pp. 816
Author(s):  
Javier Montero

Background: The treatment plan of prosthetic restorations supported by dental implants requires comprehensive scientific knowledge to deliver prostheses with good prognosis, even before the implant insertion. This review aims to analyze the main prosthetic determinants of the prognosis of implant-supported prostheses. Methods: A comprehensive review of the literature was conducted with a PICO (Patient Intervention Comparison Outcomes) question: “For partially or complete edentulous subjects treated with implant-supported prostheses, which prosthetic factors could affect clinical outcomes?”. A literature search was performed electronically in PubMed (MEDLINE), Scopus and Cochrane Library with the following equation [PROGNOS * OR RISK] FACTOR IMPLANT DENTAL, and by hand search in relevant journals and throughout the selected papers. Results: This revision was carried out based on 50 papers focused on several prosthodontics-related risk factors that were grouped as follows: implant-connection, loading protocol, transmucosal abutments, prosthetic fit, provisionalization, type of retention, impression technique, fabrication technique, and occlusion. More than a half of the studies were systematic reviews (30%), meta-analysis (16%), or prospective evaluations of prosthesis with various kinds of events (18%). However, narrative reviews of literature (14%) and in vitro/animal studies (16%) were also found. Conclusions: The current literature provides insufficient evidence for most of the investigated topics. However, based on the accumulated data, it seems reasonable to defend that the best treatment approach is the use of morse taper implants with transmucosal abutments, recorded by means of rigidly splinted copings through the pick-up technique, and screwed by milled prosthesis occlusally adjusted to minimize functional overloading.


2021 ◽  
pp. rapm-2020-102427
Author(s):  
Hanns-Christian Dinges ◽  
Thomas Wiesmann ◽  
Berit Otremba ◽  
Hinnerk Wulf ◽  
Leopold H Eberhart ◽  
...  

Background/ImportanceLiposomal bupivacaine (LB) is a prolonged release formulation of conventional bupivacaine designed for prolonging local or peripheral regional single injection anesthesia. To this day, the benefit of the new substance on relevant end points is discussed controversial.ObjectiveThe objective was to determine whether there is a difference in postoperative pain scores and morphine consumption between patients treated with LB and bupivacaine hydrochloride in a systematic review and meta-analysis.Evidence reviewRandomized controlled trials (RCT) were identified in Embase, CENTRAL, MEDLINE and Web of Science up to May 2020. Risk of bias was assessed using Cochrane methodology. Primary end points were the mean pain score difference and the relative morphine equivalent (MEQ) consumption expressed as the ratio of means (ROM) 24 and 72 hours postoperatively.Findings23 RCTs including 1867 patients were eligible for meta-analysis. The mean pain score difference at 24 hours postoperatively was significantly lower in the LB group, at −0.37 (95% CI −0.56 to −0.19). The relative MEQ consumption after 24 hours was also significantly lower in the LB group, at 0.85 (0.82 to 0.89). At 72 hours, the pain score difference was not significant at −0.25 (−0.71 to 0.20) and the MEQ ratio was 0.85 (0.77 to 0.95).ConclusionThe beneficial effect on pain scores and opioid consumption was small but not clinically relevant, despite statistical significance. The effect was stable among all studies, indicating that it is independent of the application modality.


2021 ◽  
pp. 019459982199066
Author(s):  
Sandra Ho ◽  
Prayag Patel ◽  
Daniel Ballard ◽  
Richard Rosenfeld ◽  
Sujana Chandrasekhar

Objective To systematically review the current literature regarding the operative outcomes of stapes surgery for stapes fixation via the endoscopic and microscopic approaches. Data Sources PubMed, Embase, and Web of Science. Review Methods An electronic search was conducted with the keywords “endoscop* or microscop*” and “stapes surgery or stapedectomy or stapedotomy or otosclerosis or stapes fixation.” Studies were included if they compared endoscopy with microscopy for stapes surgery performed for stapes fixation and evaluated hearing outcomes and postoperative complications. Articles focusing on stapes surgery other than for stapes fixation were excluded. Results The database search yielded 1317 studies; 12 remained after dual-investigator screening for quantitative analysis. The mean MINORS score was 18 of 24, indicating a low risk of bias. A meta-analysis demonstrated no statistically significant difference between the groups with regard to operative time, chorda tympani nerve manipulation or sacrifice, or postoperative vertigo. There was a 2.6-dB mean improvement in the change in air-bone gap in favor of endoscopic stapes surgery and a 15.2% increased incidence in postoperative dysgeusia in the microscopic group, but the studies are heterogeneous. Conclusions Endoscopic stapes surgery appears to be a reasonable alternative to microscopic stapes surgery, with similar operative times, complications, and hearing outcomes. Superior visibility with the endoscope was consistently reported in all the studies. Future studies should have standardized methods of reporting visibility, hearing outcomes, and postoperative complications to truly establish if endoscopic stapes surgery is equivalent or superior to microscopic stapes surgery.


2020 ◽  
Vol 7 (1) ◽  
Author(s):  
P. G. Robinson ◽  
T. Williamson ◽  
I. R. Murray ◽  
K. Al-Hourani ◽  
T. O. White

Abstract Purpose The purpose of this study was to perform a systematic review of the reparticipation in sport at mid-term follow up in athletes who underwent biologic treatment of chondral defects in the knee and compare the rates amongst different biologic procedures. Methods A search of PubMed/Medline and Embase was performed in May 2020 in keeping with Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. The criteria for inclusion were observational, published research articles studying the outcomes and rates of participation in sport following biologic treatments of the knee with a minimum mean/median follow up of 5 years. Interventions included microfracture, osteochondral autograft transfer (OAT), autologous chondrocyte implantation (ACI), matrix-induced autologous chondrocyte implantation (MACI), osteochondral allograft, or platelet rich plasma (PRP) and peripheral blood stem cells (PBSC). A random effects model of head-to-head evidence was used to determine rates of sporting participation following each intervention. Results There were twenty-nine studies which met the inclusion criteria with a total of 1276 patients (67% male, 33% female). The mean age was 32.8 years (13–69, SD 5.7) and the mean follow up was 89 months (SD 42.4). The number of studies reporting OAT was 8 (27.6%), ACI was 6 (20.7%), MACI was 7 (24.1%), microfracture was 5 (17.2%), osteochondral allograft was 4 (13.8%), and one study (3.4%) reported on PRP and PBSC. The overall return to any level of sport was 80%, with 58.6% returning to preinjury levels. PRP and PBSC (100%) and OAT (84.4%) had the highest rates of sporting participation, followed by allograft (83.9%) and ACI (80.7%). The lowest rates of participation were seen following MACI (74%) and microfracture (64.2%). Conclusions High rates of re-participation in sport are sustained for at least 5 years following biologic intervention for chondral injuries in the knee. Where possible, OAT should be considered as the treatment of choice when prolonged participation in sport is a priority for patients. However, MACI may achieve the highest probability of returning to the same pre-injury sporting level. Level of evidence IV


2021 ◽  
pp. 174749302110132
Author(s):  
Ahmed Mohamed ◽  
Nida Fatima ◽  
Ashfaq Shuaib ◽  
Maher Saqqur

Introduction There is controversy if direct to comprehensive center “mothership” (MS) or stopping at primary center for thrombolysis before transfer to comprehensive center “drip-and- ship” (DS) are best models of treatment of acute stroke. In this study, we compare MS and DS models to evaluate the best option of functional outcome. Methods Studies between 1990 and 2020 were extracted from online electronic databases. We compared the clinical outcomes, critical time measurements, functional independence and mortality were then compared. Results A total of 7,824 patients’ data were retrieved from 13 publications (3 randomized control trials and 10 retrospective ones). 4,639 (59.3%) patients were treated under MS model and 3,185 (40.7%) followed the DS model with mean age of 70.01±3.58 vs. 69.03±3.36; p< 0 .001, respectively. The National Institute Health Stroke Scale was 15.57±3.83 for the MS and 15.72±2.99 for the DS model (p=<0.001). The mean symptoms onset-to-puncture time was significantly shorter in the MS group compared to the DS (159.69 min vs. 223.89 min; p=<0.001, respectively). Moreover, the collected data indicated no significant difference between symptom’s onset to intravenous (IV) thrombolysis time and stroke onset-to-successful recanalization time (p=0.205 and p=<0.001, respectively). Patients had significantly worse functional outcome [modified rankin score (mRS)] (3-6) at 90-days in the DS model [Odds Ratio (OR): 1.47, 95% Confidence Interval (CI): 1.13-1.92, p<0.004] and 1.49-folds higher likelihood of symptomatic intracerebral hemorrhage (OR: 1.49, 95%CI: 1.22-1.81, p<0.0001) compared to MS. However, there were no statistically significant difference in terms of mortality (OR: 1.16, 95%CI: 0.87-1.55, p=0.32) and successful recanalization (OR: 1.12, 95%CI: 0.76-1.65, p=0.56) between the two models of care. Conclusion Patients in the MS model have significantly improved functional independence and recovery. Further studies are needed as the data from prospectively randomized studies is not of sufficient quality to make definite recommendations.


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