112 research outputs found
Self-assembly of three cationic silver(I) coordination networks with flexible bis(pyrazolyl)-based linkers
No full textThree new cationic silver(I) coordination polymers, {[Ag(mu-bpmb)](SO3CF3)}n (1), {[Ag(mu-bdb)1.5] (SO3CF3)}n (2) and {[Ag(mu-bpb)2](NO3)}n (3), with flexible 1,4-bis[(pyrazolyl)methyl]benzene (bpmb), 1,4-bis[(3,5-dimethylpyrazolyl)methyl]benzene (bdb), and 1,4-bis(pyrazolyl)butane (bpb) have been prepared at room temperature by the solvent layering method. The three compounds were characterized by FT-IR spectroscopy, PXRD, elemental analyses and single-crystal X-ray diffraction. Compound 1 is a highly undulated polymeric 1D chain in which the silver ions adopt a linear geometry, coordinating two bpmb linkers. Compounds 2 and 3 are both 2D coordination polymers with their silver atoms being three and four coordinated, and resulting in 6^3-hcb and 4^4-sql underlying net topologies, respectively. The flexible bispyrazolyl ligands display various conformations in the solid state, causing the formation of different Ag. . .Ag separations in the polymeric structures
Anion-directed assembly of three cationic silver(I) coordination polymers with bis(imidazolyl)-based linker: Structural characterization and anion exchange study
No full textThree cationic silver(I) coordination polymers, namely [Ag2(μ-bib)3](SO3CF3)2·(CH3CN)n (1), [Ag(μ-bib)](NO3)·(H2O)n (2), and [Ag(μ-bib)]BF4n (3), have been prepared using flexible bis(imidazolyl)butane (bib) ligand and silver salts of different anions. All compounds are characterized by FT-IR, PXRD, elemental analysis, and single-crystal X-ray diffraction. Compound 1, containing triflate (SO3CF3−) anions, exhibits a two dimensional 63-hcb network with an amazing ABCDEF packing mode of the single hexagonal layers. Compound 2, containing nitrate ions, forms a simple one dimensional wavy chain, while compound 3 with BF4− anions, shows a double helix DNA-shaped structure stabilized by Ag⋯Ag interactions between the two strands. The anions in the structures 1–3 are non-coordinating and participate in weak H-bonding, while imidazolyl rings are involved in π⋯π stacking interactions. Anion exchange experiments in aqueous solution, monitored by FT-IR and PXRD analyses, reveal interesting structural transformations
A preliminary analysis of late structural failures of the Navion stent graft in the treatment of descending thoracic aortic aneurysms
No full textObjective: Patients in the Valiant Evo U.S. and international clinical trials had positive short-term outcomes; however, late structural failures, including type IIIb endoleaks have been recently discovered. Type IIIb endoleaks are serious adverse events because the repressurization of the aneurysm sac increases the risk of rupture. The purpose of the present study was to detail the imaging patterns associated with the structural failures with the aim of increasing awareness of failing graft presentation, early recognition, and prompt treatment. Methods: The Valiant Evo clinical trial was a prospective, single-arm investigation of a thoracic stent graft system. With the recent late structural failures, sites were requested to submit all available imaging studies to date to allow the core laboratory to assess for structural failures such as type IIIb endoleaks, stent ring fractures, and stent ring enlargement. Of the 100 patients originally enrolled in the trial from 2016 to 2018, the core laboratory assessed the imaging studies performed at ≥1 year for 83 patients. Results: No structural failures of the graft were reported through 1 year of follow-up. At 1 to 4 years, graft structural failures were detected in 11 patients with descending thoracic aortic aneurysms. Of the 11 patients, 5 had a type IIIb endoleak. Four of the five had imaging findings showing stent fractures consistent with the location of the graft seam and one had a type IIIb endoleak attributed to calcium erosion with no stent fracture or ring enlargement. Of the four patients with stent fracture in line with the graft seam, three underwent a relining procedure that successfully excluded the type IIIb endoleak. One of these three patients died 4 days later of suspected thoracic aortic rupture because the distal thoracic endovascular aortic repair extension had been landed in a previously dissected and fragile section of the aorta. The remaining six patients had had stent ring enlargement. One of the six patients had had persistent aneurysm expansion from the time of implantation onward and had died of unknown causes. The remaining five patients have continued to be monitored. Conclusions: In the present preliminary analysis, the imaging patterns associated with type IIIb endoleaks, stent fractures, and stent ring enlargement appear to be related to the loss of seam integrity or detachment of the stent rings from the surface of the graft material. The imaging patterns we have detailed should be closely monitored using computed tomography angiography surveillance to allow structural failures to be promptly identified and treated
Outcomes from the Gore Global Registry for Endovascular Aortic Treatment in patients undergoing thoracic endovascular aortic repair for type B dissection
No full textObjective: The Global Registry for Endovascular Aortic Treatment (GREAT) is a prospective multicenter registry collecting real-world data on the performance of W. L. Gore (Flagstaff, Ariz) aortic endografts. The purpose of the present study was to analyze the implementation and outcomes of thoracic endovascular aortic repair (TEVAR) in GREAT patients with type B aortic dissection (TBAD).Methods: From 2010 to 2016, >5000 patients were enrolled in the GREAT from 113 centers in 14 countries across 4 continents. The study population comprised those treated for TBAD. The primary outcomes of interest were mortality and freedom from aortic events (AEs).Results: A total of 264 patients (80% male; mean age, 62 years) underwent TEVAR for the treatment of 170 (64%) acute and 94 (36%) chronic cases of TBAD. Chronic TBAD patients required significantly longer endograft coverage than did acute TBAD patients (P=.05). Early postoperative complications occurred in 9% of patients, with no difference in chronic vs acute dissection (P=.11). The 30-day aortic mortality and all-cause mortality were 1.5% and 2.3%, respectively, with no differences based on chronicity. During a mean follow-up of 26 months, the total aortic mortality was 2.7% and the total all-cause mortality was 12.5%. The all-cause mortality was significantly greater for chronic vs acute TBAD (19.2% vs 8.8%, respectively; P=.02). On multivariate analysis, patients with acute uncomplicated dissections had significantly improved overall survival compared with all other categories of dissections (93% vs 83% at 2 years; P<.05). A proximal landing zone diameter >40 mm was associated with an increased risk of retrograde type A dissection (18% vs 2%; P=.02). Patients undergoing left subclavian artery (LSA) coverage experienced a twofold greater rate of AEs compared with noncoverage patients (P<.01). Patients who underwent LSA revascularization experienced a 1.5-fold greater rate of AEs compared with patients covered without revascularization (P=.04).Conclusions: TEVAR for TBAD using the conformable GORE TAG thoracic endoprosthesis device can be performed with a low incidence of aortic mortality and complications. Acute uncomplicated TBAD patients had a significantly lower mortality rate than that of other patients. Larger proximal landing zones were associated with more frequent retrograde type A dissection. LSA involvement (coverage and/or revascularization) was associated with an increased risk of AEs during follow-up
Five-year outcomes of endovascular treatment for aortic dissection from the Global Registry for Endovascular Aortic Treatment
No full textObjective: The Global Registry for Endovascular Aortic Treatment (GREAT) is an International prospective multicenter registry collecting real-world data on performance of Gore aortic endografts. The purpose was to analyze the long-term outcomes and patient survival rates, as well as device performance in patients undergoing thoracic endovascular aortic repair for acute and chronic and complicated or uncomplicated type B aortic dissection (TBAD).
Methods: From August 2010 to October 2016, 5014 patients were enrolled in the GREAT registry. The study population were patients treated with thoracic endovascular aortic repair for TBAD through 5-year follow-up (days 0-2006). The primary outcomes for this analysis were all-cause and aortic-related mortality, stroke, aortic rupture, endoleaks, migration, fracture, compression, and any reintervention through 5 years.
Results: We identified 265 patients. The mean age was 60.9 ± 11.9 years (range, 19-84 years; 211 males [79.6%]). Devices used were the Gore TAG and Conformable Gore TAG Thoracic Endoprosthesis. There were 228 patients (86.0%) who underwent primary endovascular treatment (144 off-label [54.3%]); 22 (8.3%) underwent reintervention after prior endovascular procedure and 15 (5.7%) underwent reintervention after prior open procedure. Kaplan-Meier estimated freedom from all-cause mortality at 5 years was 71.1%. Freedom from aortic-related mortality through 5 years was 95.8%. There was no significant difference in freedom from all-cause mortality during the follow-up period in complicated or uncomplicated disease. At 30 days and through 5 years, respectively, for all the following outcomes, the aortic rupture rate was 1.1% (n = 3) and 1.9% (n = 5). The stroke rate was 1.1% (n = 3) and 4.2% (n = 11). The spinal cord ischemic event rate was 1.5% (n = 4) and 2.6% (n = 7). Reinterventions were required in 6.4% (n = 17) and 21.1% (n = 56) of patients. The need for conversion to open repair was 0.4% (n = 1) and 2.6% (n = 7). Additional graft placement was required in 3 patients (1.1%) and 16 patients (6.0%). The endoleak rate at 30 days was 3.4% (n = 9); type IA (n = 1 [0.4%]), type IB (n = 4 [1.5%]), type II (n = 1 [0.4%]), type III (n = 1 [0.4%]), and unspecified (n = 4 [1.6%]). Through 5 years, the endoleak rate was 12.1% (n = 32); type IA (n = 7 [2.6%]), type IB (n = 10 [3.8%]), type II (n = 9 [3.4%]), type III (n = 2 [0.8%]), and unspecified (n = 12 [4.5%]). There were no cases of stent migration, compression or fracture through 5 years.
Conclusions: Results at the 5-year follow-up demonstrate that the use of the Gore TAG and Conformable Gore TAG Thoracic Endoprosthesis can be supported in treatment of TBAD (acute, chronic, complicated, and uncomplicated). These data demonstrate strong device durability, beneficial patient outcomes, and support for the treatment of thoracic aortic dissection with an endovascular approach. Complete 10-year follow-up in GREAT as planned will be advantageous
Legitimacy in the Literature: Distinguishing Between Perceived and Actual Value Congruence in Carbon Reduction Initiatives
No full text\ua9 2025 The Author(s). Business Strategy and the Environment published by ERP Environment and John Wiley & Sons Ltd.Academic and social concerns regarding the management of carbon emissions are pressing due to the importance of carbon reduction in the fight against climate change and the strategic implications of the various approaches. In particular, the relationship between carbon reduction and legitimacy has received significant attention, with academics noting both the positive relationship between the two and the risk of ‘greenwashing’. Here, we review the extant literature on carbon reduction and legitimacy, presenting insights into the current academic discourse and highlighting an important distinction between ‘legitimacy’ as it relates to perception and ‘legitimacy’ as it relates to actual congruence between the actions of the company and social expectations. Our review demonstrates that legitimacy as perception is the dominant application of the concept in the literature, and we highlight the importance of more academic consideration of the way in which companies\u27 carbon reduction efforts actually cohere with relevant norms and values
Differences in Mid-Term Outcomes Between Patients Undergoing Thoracic Endovascular Aortic Repair for Aneurysm or Acute Aortic Syndromes: Report From the Global Registry for Endovascular Aortic Treatment
No full textPurpose: To analyze differences in baseline characteristics, overall mortality, device-related mortality, and re-intervention rates in patients who underwent thoracic endovascular aortic repair (TEVAR) for descending thoracic aortic aneurysm (DTAA) with atherosclerotic/degenerative cause or acute aortic syndrome (AAS), using the Global Registry For Endovascular Aortic Treatment (GREAT). Materials and Methods: Patients submitted to TEVAR for AAS or DTAA, included in GREAT, were eligible for this analysis. Primary outcome was 30-day all-cause mortality rate. Secondary outcomes were 30-day aorta-related mortality and re-intervention rate, 1-year and 3-year all-cause mortality, aorta-related mortality and re-intervention rate. Results: Five-hundred and seventy-five patients were analyzed (305 DTAA and 270 AAS). Thirty-day mortality rate was 1.3% and 1.8% for DTAA and AAS, respectively (p=0.741). One-year and 3-year mortality rates were 6.2% versus 9.3 and 17.3% versus 15.9% for DTAA and AAS, respectively (p=0.209 and p=0.655, respectively). Aorta-related mortality rates at 30 days, 1 year and 3 years were 1.3%, 1.3%, and 2.6% for DTAA, 1.8%, 4.2%, and 4.2% for AAS (p=ns). Re-intervention rates at 30 days, 1 year, and 3 years were 1.3%, 4.3%, and 7.5% for DTAA, 3.3%, 8.1%, and 10.7% for AAS (p=ns). Furthermore, a specific analysis with similar outcomes was performed dividing follow-up in 3 periods (1-30 days, 31-365 days, 366-1096 days) and describing mutual differences between 2 groups and temporal trends in each group. Conclusion: Patients who underwent TEVAR for DTAA or AAS experienced different mortality and re-intervention rates among years during mid-term follow-up. Although all-cause related deaths within 30 days were TEVAR-related, aorta-related deaths were more common for AAS patients within 1 year. A greater re-intervention rate was described for AAS patients, although only 1 year after TEVAR
Is corporate social responsibility always a function of good management?: an ethical relativism perspective
No full textThe debate on the relationship between business and society is an issue of practical importance and theoretical interest. This paper discusses the perspectives on the social responsibilities of organisations to indicate the diversity of approaches to the legitimacy and the boundaries of corporate social responsibility (CSR) practices. Classical Theories of Social Responsibility, The Stakeholder Theory, The Social Demandingness Theory, and The Social Activist Theory are critiqued. Finally, major arguments behind the social responsibility theories are discussed and an ethical relativism framework is proposed to assess the morality and the legitimacy of CSR practices
Is corporate social responsibility always a function of good management?
No full textThe debate on the relationship between business and society is an issue of practical importance and theoretical interest. This paper discusses the perspectives on the social responsibilities of organisations to indicate the diversity of approaches to the legitimacy and the boundaries of corporate social responsibility (CSR) practices. Classical Theories of Social Responsibility, The Stakeholder Theory, The Social Demandingness Theory, and The Social Activist Theory are critiqued. Finally, major arguments behind the social responsibility theories are discussed and an ethical relativism framework is proposed to assess the morality and the legitimacy of CSR practices. Keywords: Corporate social responsibility; philantrophy; relativism; management; stakeholde
Characterisation of adjacent pits with combined application of MFL and laser scanning techniques
No full textThe most common corrosion defect found in pipelines is adjacent pits. Adjacent pits are a group of individual pits interacting with each other. Due to their geometry, discriminating between these defects and accurately sizing them is not possible using the traditional magnetic flux
leakage (MFL) technique. Significant improvements in depth sizing accuracy can be obtained if sizing models can be optimised on high-resolution data that allows the shapes and actual dimensions of the adjacent pits to be more clearly discerned. This paper presents a new combination method
of MFL and high-resolution laser scanning techniques for improving the accuracy of depth sizing of adjacent pits. MFL and laser scanning experiments have been conducted in a laboratory set-up on pits with different edge-to-edge distances. The results of the new combination method reveal how
the additional laser scanning data, which allows increased distinction of individual pits, can help the MFL sizing model and improve the depth sizing accuracy.</jats:p
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