bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural Relaxation of Poly(methyl methacrylate)
Authors: Avramov I. , Vassilev Ts. 
Published: March 2023

The kinetics of structural, relaxation of poly(methyl methacrylate) (PMMA) is studied and it is shown that the activation energy of the process depends on the structural temperature Tf. A new method is proposed allowing the measurement experimentally of how the activation energy decreases with increasing Tf. The dependence of the glass transition temperature Tg on the heating rate q+ is investigated for samples that were previously cooled down at a rate q = 12.5 K/min. It is found that the activation energy for structural relaxation is E = (250 ± 10%) kJ/mol at T=386K. On the other hand, the value of the apparent ”activation energy” obtained from the dependence of the structural temperature Tf on the cooling rate q- is considerably higher. This is an indication that the activation energy depends on Tf. We found that the temperature dependence of the activation energy of PMMA in the vitrification interval is E(T) = 250–670* (386/T-1) kJ/mol.
Synthesis of Poly(methacrylic Acid)-Cellulose Composites Using Different Cellulosic Materials in the Presence of Potassium Permanganate and Activator
Authors: El-Sisi F. 
Published: March 2023

Polymerisation of methacrylic acid (MAA) in the presence of cellulose pulps prepared from bagasse, rice, straw and cotton stalk was carried out under a variety of conditions. Potassium permanganate (KMnO4) was used as initiator, along with either citric acid or sodium thiosulphate (Na2S2O3) as activator. The polymerisation products, including grafted cellulose, homopolymer, ungrafted cellulose and oxidised cellulose in a polyblended form, is called “composite”. Major factors affecting the polymerisation reaction were studied. These encompass initiator, activator and monomer concentrations, duration and temperature of polymerisation as well as the nature of the cellulose substrate. Results for the percent polymer yield of the composite and those of the total conversion of monomer to polymer suggest appropriate conditions for the synthesis of poly (MAA)-cellulose composite as: [KMnO4], 0 08%; [Na2S2O3], 2.5 m.mole L; [MAA], 100% based on weight of sample; material to liquor ratio, 1:30; temperature, 70°C and time, 60 minutes. The effect of the nature of the cellulose on the properties and characteristics of the composite could be realised from the following orders: (1) for the polymer yield, graft yield and swellability: bagasse > rice straw > cotton stalk; (2) for carboxyl content: bagasse > cotton stalk > rice straw; (3) for solubility: rice straw > cotton stalk > bagasse.
Image Analysis Method for Estimating 2-D Fibre Orientation and Fibre Length in Discontinuous Fibre Reinforced Composites
Authors: Pourdeyhimi B. , Ramanathan R. 
Published: March 2023

In discontinuous fibre reinforced composites (DFRC), the fibre length and orientation influence greatly the ultimate physical and mechanical properties of the material. A number of attempts dealing with methods for measuring fibre orientation are reported in the literature. These methods however, are unable to characterize fibre length. Fibre length may be affected by the type of processing involved. This study reports on the use of image analysis techniques for determining both fibre orientation and length. To verify the accuracy of the methods used, simulated images with known characteristics are used.
The Percolation Concept and the Electrical Conductivity of Carbon Black-Polymer Composites. 2: Amorphous Chloroprene Rubber Mixed with HAF Carbon Black
Authors: Ali M.H. , Abo-Hashem A. 
Published: March 2023

The concentration and temperature dependence of the electrical conductivity (a) of amorphous chloroprene rubber CR mixed with high abrasion furnace (HAF) carbon black was investigated. It was found that the concentration dependence of a satisfied the scaling law of percolation clusters [σ = σo (P-Pc)β] through the range of Pc ≤ P ≤ 0.43 where Pc is the percolation threshold, P is the carbon concentration and β is the exponent (relates to the cluster size). The difference between the value of β obtained and that given by the scaling law was attributed to the occluded rubber which acts as if it were carbon rather than matrix. The occupation number (Z) was found to be 8.2 as calculated from the percolation threshold. The correlation between β and Z was found to be β = Z + 1. It was also found that the filling factor for HAF carbon was 0.70, which is the mean of the values for random close packed spheres and uniaxial simple cubic packed rods. Conductivity was thermally activated below the percolation threshold. Above it, the variation of σ with temperature was attributed to the breakdown and reformation of carbon clusters with temperature.
The Percolation Concept and the Electrical Conductivity of Carbon Black-Polymer Composites. 3. Crystalline Chloroprene Rubber Mixed with FEF Carbon Black
Authors: Ali M.H. , Abo-Hashem A. 
Published: March 2023

The filler concentration and temperature dependence of the electrical conductivity (a) of crystalline chloroprene rubber CR (Butaclor 41H) mixed with fast extrusion furnace (FEF) carbon black was investigated. It was found that the percolation concept held true for these composites, where σ shows a fairly sharp increase when the mass fraction of FEF carbon black in the mixture exceeds 20%. The estimated values of the filling factor (f) and the occupation number (Z) were found to be 0.82 and 8.2 respectively. The scaling law for percolation clusters [σ = σo (P - Pc)β] was valid within the range Pc ≤ P ≤ 0.34 and the estimated value of the exponent β was 6.8, where P = concentration of filler and Pc = the critical concentration. The conductivity was thermally activated below and at the percolation threshold, with the same activation energy. The decrease in c with temperature (followed by a subsequent increase above a certain temperature) was attributed to the phase transition of CR (41H) and to the change in size of the carbon black clusters from infinite to finite with temperature. In the more highly loaded compounds, the temperature dependence of σ was controlled by the breakdown and reformation of carbon clusters with temperature.
Venous Thromboembolism in a Patient with Interrupted Inferior Vena Cava and Compressed Azygos Continuation: A Case Report and Review of Literature
Authors: Kwan Kristine JS , Li Hai-Lei , Chan Yiu Che , Huang Jian-Xiong , Cui Dong-Zhe , Cheng Stephen WK 
Published: March 2023

We report an unusual case of a 40-year-old male patient who experienced painful swelling of the left lower limb that persisted for 1 week. Imaging modalities not only confirmed the diagnosis of acute iliofemoral venous thrombosis and pulmonary embolism (PE), but also an incidental finding of interrupted inferior vena cava (IVC). This congenital anomaly is uncommon but rarely associated with venous thromboembolism (VTE). The azygos continuation was compressed by the descending aorta against the 11th thoracic vertebrae, which was identified as the cause of VTE. He was treated successfully with anticoagulation and compression therapy. The patient was discharged with lifelong oral Rivaroxaban and remained asymptomatic. In the literature, only 9 cases of interrupted IVC-associated PE were identified but none was due to significant venous compression.
Knowledge atlas analysis of virtual vascular interventional studies
Authors: Qingfu Hu , Zongkai Yu , Zhenhua Wang , Zhenshuang Du 
Published: March 2023

Objective To examine the research status, hot spots, and development trend of virtual vascular intervention simulation training in order to organize the knowledge and support its practice. Methods Publications on virtual vascular intervention and respective teaching evaluation (2001–2021) were retrieved from Web of Science. Citespace 5.2.R2 and Carrot2 software was used to perform the bibliometric and visual analysis on virtual vascular intervention research networks. Results Of the 1543 articles retrieved, 1520 were relevant to virtual vascular intervention research. Studies on vascular intervention emerged from 2002 with an upward trend being observed from 2010. The trend peaked between 2019 and 2020 with ∼140 published articles (9.21%) during the period. Spain published most studies ( n = 146) followed by USA ( n = 99) and England ( n = 49). COMPUT EDUC ( n = 177; 14.47%) journal publishing the highest number of articles. Among 705 authors, GARRISON D R, MAYER RE, DEDE C, COOK DA had highest publications. The frequent keywords used were “Virtual reality” ( n = 105) and “education” ( n = 105). Low cooperation between countries, authors’ networks, and relatively stable academic team was noted making clinical application of virtual vascular intervention weak. Conclusion Considerable growth was observed in vascular intervention therapy using VR technology in the last 20 years. With consistent efforts like strengthening cross-institutional and multidisciplinary collaboration networks, VR based simulation training capability can be increased that in turn can improve the outcomes of complex vascular interventions.
Reducing carbon footprint by switching to reusable soft-mist inhalers
Authors: Janson Christer , Hernando Platz Jaime , Soulard Stéphane , Langham Sue , Nicholson Lindsay , Hartgers-Gubbels Elisabeth Sophia 
Published: March 2023

ObjectiveInhalation therapy is the cornerstone of COPD, together with non-pharmacological treatments. Long-acting muscarinic antagonists (LAMAs), alone or in combination with long-acting β-agonists (LABAs), are commonly used. Pressurised metered-dose inhalers (pMDIs), dry powder inhalers (DPIs) and soft-mist inhalers (SMIs) are used, each with different carbon footprints. This study aimed to assess the carbon footprint of hypothetically replacing LAMA or LAMA/LABA inhalers with an SMI, Respimat Reusable, within the same therapeutic class.MethodsAn environmental impact model was established to assess the change in carbon footprint of replacing pMDIs/DPIs with Respimat Reusable within the same therapeutic class (LAMA or LAMA/LABA) across 12 European countries and the USA over 5 years. Inhaler use for country and disease-specific populations was derived from international prescribing data and the associated carbon footprint (CO2equivalents (CO2e)) was identified from published sources.ResultsOver 5 years and across all countries, replacing LAMA inhalers with Spiriva Respimat Reusable reduced CO2e emissions by 13.3–50.9%, saving 93–6228 tonnes of CO2e in the different countries studied. Replacing LAMA/LABA inhalers with Spiolto Respimat Reusable reduced CO2e emissions by 9.5–92.6%, saving 31–50 843 tonnes of CO2e. In scenario analyses, which included total replacement of DPIs/pMDIs, consistent CO2e savings were estimated. Sensitivity analyses showed that results were sensitive to changes in several parameters including varying assumptions around reusability of inhalers and potential CO2e impact.ConclusionReplacement of pMDIs and DPIs with Respimat Reusable within the same therapeutic class would result in substantial reductions in CO2e emissions.
Investigation and outcomes in patients with nonspecific pleuritis: results from the International Collaborative Effusion database
Authors: Sundaralingam Anand , Aujayeb Avinash , Jackson Karl A. , Pellas Emilia I. , Khan Irfan I. , Chohan Muhammad T. , Joosten Roos , Boersma Anton , Kerkhoff Jordy , Bielsa Silvia , Porcel Jose M. , Rozman Ales , Marc-Malovrh Mateja , Welch Hugh , Symonds Jenny , Anevlavis Stavros , Froudrakis Marios , Mei Federico , Zuccatosta Lina , Gasparini Stefano , Gonnelli Francesca , Dhaliwal Inderdeep , Mitchell Michael A. , Fjaellegaard Katrine , Petersen Jesper K. , Ellayeh Mohamed , Rahman Najib M. , Burden Tom , Bodtger Uffe , Koegelenberg Coenraad F.N. , Maskell Nick A. , Janssen Julius , Bhatnagar Rahul 
Published: March 2023

IntroductionWe present findings from the International Collaborative Effusion database, a European Respiratory Society clinical research collaboration. Nonspecific pleuritis (NSP) is a broad term that describes chronic pleural inflammation. Various aetiologies lead to NSP, which poses a diagnostic challenge for clinicians. A significant proportion of patients with this finding eventually develop a malignant diagnosis.Methods12 sites across nine countries contributed anonymised data on 187 patients. 175 records were suitable for analysis.ResultsThe commonest aetiology for NSP was recorded as idiopathic (80 out of 175, 44%). This was followed by pleural infection (15%), benign asbestos disease (12%), malignancy (6%) and cardiac failure (6%). The malignant diagnoses were predominantly mesothelioma (six out of 175, 3.4%) and lung adenocarcinoma (four out of 175, 2.3%). The median time to malignant diagnosis was 12.2 months (range 0.8–32 months). There was a signal towards greater asbestos exposure in the malignant NSP group compared to the benign group (0.63versus0.27, p=0.07). Neither recurrence of effusion requiring further therapeutic intervention nor initial biopsy approach were associated with a false-negative biopsy. A computed tomography finding of a mass lesion was the only imaging feature to demonstrate a significant association (0.18versus0.01, p=0.02), although sonographic pleural thickening also suggested an association (0.27versus0.09, p=0.09).DiscussionThis is the first multicentre study of NSP and its associated outcomes. While some of our findings are reflected by the established body of literature, other findings have highlighted important areas for future research, not previously studied in NSP.
Does hiatal hernia impact gastro-oesophageal reflux-related chronic cough?
Authors: Truba Olga , Żuchowska Joanna , Grabczak Elżbieta M. , Białek-Gosk Katarzyna , Rybka-Frączek Aleksandra , Krenke Rafał , Dąbrowska Marta 
Published: March 2023

BackgroundHiatal hernia may coexist with gastro-oesophageal reflux (GOR)-related chronic cough. This study aimed to evaluate whether the presence of hiatal hernia was related to chronic cough severity and the response to antireflux therapy.MethodsThis was a retrospective analysis of data on adults with GOR-related chronic cough managed in our cough centre between 2017 and 2021. Patients who had undergone chest computed tomography (CT) and in whom follow-up data were available were included. The presence and size of hiatal hernia were assessed based on thorax CT scanning. Patients were treated with modification of diet and proton pump inhibitors. The response to treatment was assessed by the change in quality of life (QOL) measured by Leicester Cough Questionnaire (LCQ) and cough severity was measured by 100-mm visual analogue scale.Results45 adults (28 female, 17 male) were included. Hiatal hernia was demonstrated in 12 (26.6%) patients. Patients with hiatal hernia did not differ from those without hiatal hernia in clinical characteristics, cough duration and severity and cough-related QOL. We found moderate positive correlations between maximal sagittal diameter of hiatal hernia and cough severity (ρ=0.692, p=0.013) and duration (ρ=0.720, p=0.008). Patients without hiatal hernia responded better to antireflux therapy, with significant LCQ improvement. A strong negative correlation between sagittal diameter of hiatal hernia gate and increase in LCQ (ρ= −0.764, p=0.004) was demonstrated.ConclusionThe presence of hiatal hernia identified in chest CT may impact cough severity, duration and response to antireflux treatment in patients with GOR-related chronic cough. Further prospective studies are justified to confirm significance of hiatal hernia in the management of chronic cough.
The association between diabetes and abdominal aortic aneurysms in men: results of two Danish screening studies, a systematic review, and a meta-analysis of population-based screening studies
Authors: Larsen Katrine Lawaetz , Kavaliunaite Egle , Rasmussen Lars Melholt , Hallas Jesper , Diederichsen Axel , Steffensen Flemming Hald , Busk Martin , Frost Lars , Urbonaviciene Grazina , Lambrechtsen Jess , Egstrup Kenneth , Lindholt Jes Sanddal 
Published: March 2023

Background
A paradoxical protective effect of diabetes on the development and progression of abdominal aortic aneurysms (AAA) has been known for years. This study aimed to investigate whether the protective role of diabetes on AAAs has evolved over the years.

Methods
A cross-sectional study, a systematic review and meta-analysis. This study was based on two large, population-based, randomised screening trials of men aged 65–74; VIVA (2008–2011) and DANCAVAS (2014–2018), including measurement of the abdominal aorta by ultrasound or CT, respectively. Analyses were performed using multiple logistic regressions to estimate the odds ratios (ORs) for AAAs in men with diabetes compared to those not having diabetes. Moreover, a systematic review and meta-analysis of population-based screening studies of AAAs to visualise a potential change of the association between diabetes and AAAs. Studies reporting only on women or Asian populations were excluded.

Results
In VIVA, the prevalence of AAA was 3.3%, crude OR for AAA in men with diabetes 1.04 (95% confidence interval, CI, 0.80-1.34), and adjusted OR 0.64 (CI 0.48-0.84). In DANCAVAS, the prevalence of AAA was 4.2%, crude OR 1.44 (CI 1.11-1.87), and adjusted OR 0.78 (CI 0.59-1.04). Twenty-three studies were identified for the meta-analysis (N = 224 766). The overall crude OR was 0.90 (CI 0.77-1.05) before 2000 and 1.16 (CI 1.03-1.30) after 1999. The overall adjusted OR was 0.63 (CI 0.59-0.69) before 2000 and 0.69 (CI 0.57-0.84) after 1999.

Conclusion
Both the crude and adjusted OR showed a statistically non-significant trend towards an increased risk of AAA by the presence of diabetes. If this represents an actual trend, it could be due to a change in the diabetes population.

Trial registration
DANCAVAS: Current Controlled Trials: ISRCTN12157806. VIVA: ClinicalTrials.gov NCT00662480.
Efficacy of azithromycin in treating Ureaplasma urealyticum: a systematic review and meta-analysis
Authors: Fan Weibin , Wang Qisheng , Liang Zuyu , Wang Jinyu , Zhang Lin 
Published: March 2023

Abstract
Background
Ureaplasma urealyticum is the most prevalent genital mycoplasma isolated from the urogenital tract of females, but there is no unified treatment plan. This study aimed to evaluate the efficacy of azithromycin in treating Ureaplasma urealyticum.

Methods
From the earliest to June 2022, published randomized controlled trials (RCTs) on azithromycin treatment of Ureaplasma urealyticum were retrieved by searching PubMed, Embase, Cochrane Library, and Web of Science. Two reviewers independently extracted the data. We utilized the Cochrane risk-of-bias assessment technique to assess the quality of included RCTs. The data were analyzed using the R language (version 4.0.4) software.

Results
Seven RCTs were finally included, involving 512 participants (240 in the experimental group, 272 in the control group). The experimental group was treated with azithromycin monotherapy, while the control group was treated with doxycycline or a placebo. Meta-analysis results suggested that azithromycin has a comparable therapeutic effect on Ureaplasma urealyticum in comparison to that of controls (risk ratio [RR] = 1.03, 95% confidence interval [CI] 0.94–1.12). Subgroup analysis showed that the dose and duration of azithromycin may don’t affect its efficacy.

Conclusion
Regarding the meta-analysis that we performed based on existing clinical studies, azithromycin is quite effective in treating Ureaplasma urealyticum.
SNHG18 inhibits bladder cancer cell proliferation by increasing p21 transcription through destabilizing c-Myc protein
Authors: Ke Meixia , Sun Ning , Lin Zhenni , Zhang Peipei , Hu Yan , Wu Shuilian , Zheng Zhijian , Lu Yongyong , Jin Honglei 
Published: March 2023

Abstract
Background
Long non-coding RNAs (lncRNAs) have been confirmed to play important roles in various cancers including bladder cancer (BC). The precise expression pattern of lncRNA small nucleolar RNA host gene 18 (SNHG18) in BC and its mechanisms of action have not been fully explored.

Materials and methods
The expression of SNHG18 was evaluated by RT-qPCR in bladder cancer clinical samples and human bladder cancer cell lines, and stable cell lines overexpressing SNHG18 were constructed. The effect of SNHG18 on the proliferation of bladder cancer cells was detected by soft agar colony formation test, ATP activity test and subcutaneous tumorigenesis model in nude mice. The specific mechanism of SNHG18 inhibition of bladder cancer proliferation was studied by flow cytometry, western blotting, dual luciferase reporter gene assay and protein degradation assay.

Results
We found that SNHG18 is significantly downregulated in BC tissues and cell lines. Kaplan–Meier analysis showed that SNHG18 expression is positively correlated with survival in BC patients. Ectopic overexpression of SNHG18 significantly inhibited the proliferation of BC cells in vitro and in vivo. Further mechanistic investigations demonstrated that SNHG18 inhibited c-Myc expression by modulating the ubiquitination-proteasome pathway and that c-Myc is the critical transcription factor that mediates SNHG18 inhibition of BC growth by directly binding to the p21 promoter, which was attributed with significant p21 accumulation.

Conclusions
SNHG18 promotes the transcription and expression of p21 by inhibiting c-Myc expression, leading to G0-G1 arrest and inhibiting the proliferation of bladder cancer cells. These findings highlight a novel cell cycle regulatory mechanism involving the SNHG18/c-Myc/p21 pathway in BC pathogenesis and could potentially lead to new lncRNA-based diagnostics and/or therapeutics for BC.
Anti-inflammatory activity of non-selective PDE inhibitor aminophylline on the lung tissue and respiratory parameters in animal model of ARDS
Authors: Kosutova Petra , Mikolka Pavol , Mokra Daniela , Calkovska Andrea 
Published: March 2023

AbstractAcute respiratory distress syndrome (ARDS) is a common complication of critical illness characterized by lung inflammation, epithelial and endothelial dysfunction, alveolar-capillary leakage, and worsening respiratory failure. The present study aimed to investigate the anti-inflammatory effects of non-selective phosphodiesterase (PDE) inhibitor aminophylline. New Zealand white rabbits were randomly divided into 3 groups: animals with respiratory failure defined as PaO2/FiO2 ratio (P/F) below < 26.7 kPa, and induced by saline lung lavage (ARDS), animals with ARDS treated with intravenous aminophylline (1 mg/kg; ARDS/AMINO), and healthy ventilated controls (Control). All animals were oxygen ventilated for an additional 4 h and respiratory parameters were recorded regularly. Post mortem, the lung tissue was evaluated for oedema formation, markers of inflammation (tumor necrosis factor, TNFα, interleukin (IL)-1β, -6, -8, -10, -13, -18), markers of epithelial damage (receptor for advanced glycation end products, RAGE) and endothelial injury (sphingosine 1-phosphate, S1P), oxidative damage (thiobarbituric acid reactive substances, TBARS, 3-nitrotyrosine, 3NT, total antioxidant capacity, TAC). Aminophylline therapy decreased the levels of pro-inflammatory cytokines, markers of epithelial and endothelial injury, oxidative modifications in lung tissue, reduced lung oedema, and improved lung function parameters compared to untreated ARDS animals. In conclusion, non-selective PDE inhibitor aminophylline showed a significant anti-inflammatory activity suggesting a potential of this drug to be a valuable component of ARDS therapy.