scholarly journals Is Fracture Toughness of PUR Foams a Material Property? A Statistical Approach

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4868
Author(s):  
Adrian Pugna ◽  
Romeo Negrea ◽  
Emanoil Linul ◽  
Liviu Marsavina

The published data on the experimentally determined fracture toughness of foams are based on a small number of specimens, having a lack of statistical consistency. The paper proposes a statistical approach on the fracture toughness results of rigid polyurethane (PUR) foams of three different densities. Five types of fracture tests were considered. The results were statistically analyzed using six types of regressions and a meta-analysis to identify the factors influencing the fracture toughness. The statistical analysis indicates that the fracture toughness represents a material property because does not depend on the specimen type. The density plays a major role in the fracture toughness of PUR foams. The irregular shape of the cells induced small anisotropy for low-density foams (100 kg/m3 and 145 kg/m3). This effect could not be observed for the foam with 300 kg/m3 density, for which the cells have a more regular spherical shape. The statistical analysis indicates that the influence of the loading speed is very weak.

BMJ Open ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. e033267
Author(s):  
Dengfeng Wang ◽  
Yang Yu ◽  
Pengxian Tao ◽  
Dan Wang ◽  
Yajing Chen ◽  
...  

IntroductionVenous thromboembolism (VTE) is a serious life-threatening complication in patients with gastric cancer. Abnormal coagulation function and tumour-related treatment may contribute to the occurrence of VTE. Many guidelines considered that surgical treatment would put patients with cancer at high risk of VTE, so positive prevention is needed. However, there are no studies that have systematically reviewed the postoperative risk and distribution of VTE in patients with gastric cancer. We thus conduct this systematic review to determine the risk of VTE in patients with gastric cancer undergoing surgery and provide some evidence for clinical decision-making.Methods and analysisStudies reporting the incidence of VTE after gastric cancer surgery will be included. Primary studies of randomised controlled trials, cohort studies, population-based surveys and cross-sectional studies are eligible for this review and only studies published in Chinese and English will be included. We will search the Medline, Embase, Web of Science, CBM, CNKI and Wanfang data from their inception to November 2019. Two reviewers will independently select studies and extract data. The quality of each included study will be assessed with tools corresponding to their study design. Meta-analysis will be used to pool the incidence data from included studies. Heterogeneity of the estimates across studies will be assessed, if necessary, a subgroup analysis will be performed to explore the source of heterogeneity. The Grades of Recommendation, Assessment, Development and Evaluation method is applied to assess the level of evidence obtained from this systematic review.Ethics and disseminationThis proposed systematic review and meta-analysis is based on published data, and thus ethical approval is not required. The results of this review will be sought for publication.PROSPERO registration numberCRD42019144562


Vascular ◽  
2021 ◽  
pp. 170853812199127
Author(s):  
Lixin Wang ◽  
Enci Wang ◽  
Fei Liu ◽  
Wei Zhang ◽  
Xiaolong Shu ◽  
...  

Objective This systematic review and meta-analysis evaluated the published data on the efficacy and safety of therapies for superior mesenteric venous thrombosis (SMVT), aiming to provide a reference and set of recommendations for clinical treatment. Methods Relevant databases were searched for studies published from 2000 to June 2020 on SMVT treated with conservative treatment, surgical treatment, or endovascular approach. Different treatment types were grouped for analysis and comparison, and odds ratios with corresponding 95% confidence intervals were calculated. The outcomes were pooled using meta-analytic methods and presented by forest plots. Results Eighteen articles, including eight on SMVT patients treated with endovascular therapies, were enrolled. The treatment effectiveness was compared between different groups according to the change of symptoms, the occurrence of complications, and mortality as well. The conservative treatment group had better efficacy compared to the surgery group (89.0% vs. 78.6%, P <0.05), and the one-year survival rate was also higher (94.4% vs. 80.0%, P >0.05), but without statistical significance. As for endovascular treatment, the effectiveness was significantly higher than the surgery group (94.8% vs. 75.2%, P <0.05), and the conservative treatment group as well (93.3% vs. 86.3%, P >0.05), which still requires further research for the lack of statistical significance. Conclusions Present findings indicate that anticoagulation, as conservative treatment should be the preferred clinical option in the clinic for SMVT, due to its better curative effect compared to other treatment options, including lower mortality, fewer complications, and better prognosis. Moreover, endovascular treatment is a feasible and promising approach that is worth in-depth research, for it is less invasive than surgery and has relatively better effectiveness, thus can provide an alternative option for SMVT treatment and may be considered as a reliable method in clinical.


2021 ◽  
Vol 108 (Supplement_2) ◽  
Author(s):  
A A Tahir ◽  
K M Ali ◽  
A U Khan ◽  
S Kamal ◽  
A Hussain ◽  
...  

Abstract Introduction Diverticular disease is a common health problem with a wide clinical spectrum. About 75% of the patients would have uncomplicated diverticulitis. Cornerstones of treatment are antibiotics, analgesia, and dietary advice. Recent evidence has shown that its treatment is controversial, questioning the use of antibiotics. Aim is to assess the role of antibiotics in the treatment of acute uncomplicated diverticulitis. Method This is a systematic review and Meta-analysis. Literature review of the available studies was conducted using search engines like Pubmed, Medline, Embase, Google Scholar, and Cochrane databases. Statistical analysis was conducted using RevMan5.4. Results Out of 1754 records 1324 were duplicates, 430 studies were screened. 395 were further excluded.35 full text articles were assessed and in the final review 10 studies were included. PRISMA guidelines were used. Pooled OR for recurrence = 0.92 (95% CI = 0.74 to 1.13). Pooled OR for Hospital stay= -0.66 (95% CI= -1.12 to -0.21). Pooled OR for complications = 1.06 (95% CI = 0.69 to 1.64). Pooled OR for treatment failure= 1.24 (95% CI = 0.90-1.69). Conclusions We conclude that from the available evidence antibiotics have no role in reducing recurrence, complications, treatment failure, and duration of hospital stay in acute uncomplicated diverticulitis.


Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 120
Author(s):  
Emanuela Martina ◽  
Federico Diotallevi ◽  
Giulia Radi ◽  
Anna Campanati ◽  
Annamaria Offidani

Botulinum toxin is a superfamily of neurotoxins produced by the bacterium Clostridium Botulinum with well-established efficacy and safety profile in focal idiopathic hyperhidrosis. Recently, botulinum toxins have also been used in many other skin diseases, in off label regimen. The objective of this manuscript is to review and analyze the main therapeutic applications of botulinum toxins in skin diseases. A systematic review of the published data was conducted, following Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Botulinum toxins present several label and off-label indications of interest for dermatologists. The best-reported evidence concerns focal idiopathic hyperhidrosis, Raynaud phenomenon, suppurative hidradenitis, Hailey–Hailey disease, epidermolysis bullosa simplex Weber–Cockayne type, Darier’s disease, pachyonychia congenita, aquagenic keratoderma, alopecia, psoriasis, notalgia paresthetica, facial erythema and flushing, and oily skin. Further clinical trials are still needed to better understand the real efficacy and safety of these applications and to standardize injection and doses protocols for off label applications.


Author(s):  
Kirsty L. Ress ◽  
Gus Koerbin ◽  
Ling Li ◽  
Douglas Chesher ◽  
Phillip Bwititi ◽  
...  

AbstractObjectivesVenous blood gas (VBG) analysis is becoming a popular alternative to arterial blood gas (ABG) analysis due to reduced risk of complications at phlebotomy and ease of draw. In lack of published data, this study aimed to establish reference intervals (RI) for correct interpretation of VBG results.MethodsOne hundred and 51 adult volunteers (101 females, 50 males 18–70 y), were enrolled after completion of a health questionnaire. Venous blood was drawn into safePICO syringes and analysed on ABL827 blood gas analyser (Radiometer Pacific Pty. Ltd.). A non-parametric approach was used to directly establish the VBG RI which was compared to a calculated VBG RI based on a meta-analysis of differences between ABG and VBGResultsAfter exclusions, 134 results were used to derive VBG RI: pH 7.30–7.43, partial pressure of carbon dioxide (pCO2) 38–58 mmHg, partial pressure of oxygen (pO2) 19–65 mmHg, bicarbonate (HCO3−) 22–30 mmol/L, sodium 135–143 mmol/L, potassium 3.6–4.5 mmol/L, chloride 101–110 mmol/L, ionised calcium 1.14–1.29 mmol/L, lactate 0.4–2.2 mmol/L, base excess (BE) −1.9–4.5 mmol/L, saturated oxygen (sO2) 23–93%, carboxyhaemoglobin 0.4–1.4% and methaemoglobin 0.3–0.9%. The meta-analysis revealed differences between ABG and VBG for pH, HCO3−, pCO2 and pO2 of 0.032, −1.0 mmol/L, −4.2 and 39.9 mmHg, respectively. Using this data along with established ABG RI, calculated VBG RI of pH 7.32–7.42, HCO3− 23 – 27 mmol/L, pCO2 36–49 mmHg (Female), pCO2 39–52 mmHg (Male) and pO2 43–68 mmHg were formulated and compared to the VBG RI of this study.ConclusionsAn adult reference interval has been established to assist interpretation of VBG results.


2001 ◽  
Vol 85 (04) ◽  
pp. 626-633 ◽  
Author(s):  
Augusto Di Castelnuovo ◽  
Giovanni de Gaetano ◽  
Maria Benedetta Donati ◽  
Licia Iacoviello

SummaryMembrane glycoprotein IIb/IIIa plays a major role in platelet function. The gene encoding the glycoprotein IIIa shows a common polymorphism PlA1/PlA2 that was variably associated with vascular disease. To clarify the role of PlA1/PlA2 polymorphism in coronary risk, a meta-analysis of published data was conducted. Studies were identified both by MEDLINE searches, and hand searching of journals and abstract books.A total of 34 studies for coronary artery disease (CAD), and 6 for restenosis after revascularization were identified, for a total of 9,095 cases and 12,508 controls. In CAD, the overall odds ratio for carriers of the PlA2 allele was 1.10 (95% CI: 1.03 to 1.18), and it was 1.21 (95% CI: 1.05 to 1.38) in subjects younger than 60. Overall odds ratio was 1.31 (95% CI: 1.10 to 1.56) after revascularization procedures.The association of PlA2 status with overall cardiovascular disease in the general population is significant but weak; higher risk has been identified in less heterogeneous subgroups as in the younger cohorts and in the restenosis subset with stents.


Sign in / Sign up

Export Citation Format

Share Document