56 research outputs found
Molecular simulation of chevrons in confined smectic liquid crystals
Chevron structures adopted by confined smectic liquid crystals
are investigated via molecular dynamics simulations of the Gay-Berne
model. The chevrons are formed by quenching nematic films confined
between aligning planar substrates whose easy axes have opposing
azimuthal components. When the substrates are perfectly smooth, the
chevron formed migrates rapidly towards one of the confining walls to
yield a tilted layer structure. However, when substrate roughness is
included, by introducing a small-amplitude modulation to the particle-
substrate interaction well-depth, a symmetric chevron is formed which
remains stable over sufficiently long runtimes for detailed structural
information, such as the relevant order parameters and director orien-
tation, to be determined. For both smooth and rough boundaries, the
smectic order parameter remains non-zero across the entire chevron,
implying that layer identity is maintained across the chevron tip. Also, when the surface-stabilised chevron does eventually revert to a tilted layer structure, it does so via surface slippage, such that layer integrity is maintained throughout the chevron to tilted layer relaxation process.
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Perspectives on care and communication involving incurably ill Turkish and Moroccan patients, relatives and professionals: a systematic literature review
<p>Abstract</p> <p>Background</p> <p>Our aim was to obtain a clearer picture of the relevant care experiences and care perceptions of incurably ill Turkish and Moroccan patients, their relatives and professional care providers, as well as of communication and decision-making patterns at the end of life. The ultimate objective is to improve palliative care for Turkish and Moroccan immigrants in the Netherlands, by taking account of socio-cultural factors in the guidelines for palliative care.</p> <p>Methods</p> <p>A systematic literature review was undertaken. The data sources were seventeen national and international literature databases, four Dutch journals dedicated to palliative care and 37 websites of relevant national and international organizations. All the references found were checked to see whether they met the structured inclusion criteria. Inclusion was limited to publications dealing with primary empirical research on the relationship between socio-cultural factors and the health or care situation of Turkish or Moroccan patients with an oncological or incurable disease. The selection was made by first reading the titles and abstracts and subsequently the full texts. The process of deciding which studies to include was carried out by two reviewers independently. A generic appraisal instrument was applied to assess the methodological quality.</p> <p>Results</p> <p>Fifty-seven studies were found that reported findings for the countries of origin (mainly Turkey) and the immigrant host countries (mainly the Netherlands). The central themes were experiences and perceptions of family care, professional care, end-of-life care and communication. Family care is considered a duty, even when such care becomes a severe burden for the main female family caregiver in particular. Professional hospital care is preferred by many of the patients and relatives because they are looking for a cure and security. End-of-life care is strongly influenced by the continuing hope for recovery. Relatives are often quite influential in end-of-life decisions, such as the decision to withdraw or withhold treatments. The diagnosis, prognosis and end-of-life decisions are seldom discussed with the patient, and communication about pain and mental problems is often limited. Language barriers and the dominance of the family may exacerbate communication problems.</p> <p>Conclusions</p> <p>This review confirms the view that family members of patients with a Turkish or Moroccan background have a central role in care, communication and decision making at the end of life. This, in combination with their continuing hope for the patient’s recovery may inhibit open communication between patients, relatives and professionals as partners in palliative care. This implies that organizations and professionals involved in palliative care should take patients’ socio-cultural characteristics into account and incorporate cultural sensitivity into care standards and care practices<it>.</it></p
Robot-assisted versus laparoscopic pancreatoduodenectomy: a pan-European multicenter propensity-matched study
Background: The use of robot -assisted and laparoscopic pancreatoduodenectomy is increasing, yet large adjusted analyses that can be generalized internationally are lacking. This study aimed to compare outcomes after robot -assisted pancreatoduodenectomy and laparoscopic pancreatoduodenectomy in a pan-European cohort. Methods: An international multicenter retrospective study including patients after robot -assisted pancreatoduodenectomy and laparoscopic pancreatoduodenectomy from 50 centers in 12 European countries (2009-2020). Propensity score matching was performed in a 1:1 ratio. The primary outcome was major morbidity (Clavien-Dindo >= III). Results: Among 2,082 patients undergoing minimally invasive pancreatoduodenectomy, 1,006 underwent robot -assisted pancreatoduodenectomy and 1,076 laparoscopic pancreatoduodenectomy. After matching 812 versus 812 patients, the rates of major morbidity (31.9% vs 29.6%; P = .347) and 30-day/inhospital mortality (4.3% vs 4.6%; P = .904) did not differ significantly between robot -assisted pancreatoduodenectomy and laparoscopic pancreatoduodenectomy, respectively. Robot -assisted pancreatoduodenectomy was associated with a lower conversion rate (6.7% vs 18.0%; P < .001) and higher lymph node retrieval (16 vs 14; P = .003). Laparoscopic pancreatoduodenectomy was associated with shorter operation time (446 minutes versus 400 minutes; P < .001), and lower rates of postoperative pancreatic fistula grade B/C (19.0% vs 11.7%; P < .001), delayed gastric emptying grade B/C (21.4% vs 7.4%; P < .001), and a higher R0 -resection rate (73.2% vs 84.4%; P < .001). Conclusion: This European multicenter study found no differences in overall major morbidity and 30day/in-hospital mortality after robot -assisted pancreatoduodenectomy compared with laparoscopic pancreatoduodenectomy. Further, laparoscopic pancreatoduodenectomy was associated with a lower rate of postoperative pancreatic fistula, delayed gastric emptying, wound infection, shorter length of stay, and a higher R0 resection rate than robot -assisted pancreatoduodenectomy. In contrast, robot -assisted pancreatoduodenectomy was associated with a lower conversion rate and a higher number of retrieved lymph nodes as compared with laparoscopic pancreatoduodenectomy. (c) 2024 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
Defining Global Benchmarks for Laparoscopic Liver Resections: An International Multicenter Study
Impact of liver cirrhosis, the severity of cirrhosis, and portal hypertension on the outcomes of minimally invasive left lateral sectionectomies for primary liver malignancies
Analytical expression for off-axis light transmission through homogeneously oriented LC.
Statistically sound application of fiber push-out method for the study of locally non-uniform interfacial properties of SiC-SiC fiber composites
Push-out tests were performed on SiC-SiC fiber composites with single- and multi-layered pyrolytic carbon fiber-matrix interphases. It is shown that experimental scatter is significant and a large number of tests is necessary in order to obtain statistically relevant values of interfacial shear strength. A difference between the regions of an individual fiber tow is observed, linked to local porosity. Interfacial debonding occurs along the boundary between the fiber and the first carbon layer, regardless of the structure of the interphase, and therefore interfacial shear strength is not directly linked to the structure of the interphase
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