Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Zentralbl Chir ; 146(5): 452-457, 2021 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-34666356

RESUMO

Vascular surgery has developed very dynamically in recent years, especially with the introduction of endovascular techniques. However, this has also changed surgeons' requirements. Classical surgical procedures have been almost completely displaced by endovascular techniques; new hybrid interventions have emerged while complex operations are concentrated in few centres. Therefore, developing expertise in open aortic surgery is increasingly challenging in vascular surgical training programs.Cadaver models provide an opportunity for exposure and repetitive training of individual surgical steps without endangering patients.As part of the training of highly complex vascular surgery operations, we carried out and evaluated the thoracoabdominal aortic replacement with 13 participants in 6 ethanol-preserved corpses.A simulation of surgical procedures on human cadaveric models cannot fully replace real experiences, but allows surgeons in training to practice and achieve dexterity in performing procedures in a safe and reproducible way.


Assuntos
Procedimentos Endovasculares , Cirurgiões , Cadáver , Competência Clínica , Educação de Pós-Graduação em Medicina , Humanos
2.
Molecules ; 25(11)2020 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-32545377

RESUMO

The extraction and characterization of defined and carboxyl-rich oligomeric lignin fragments with narrow molecular weight distribution is presented herein. With regard to the well-known pulp bleaching process, oxidative lignin depolymerization was investigated using hydrogen peroxide in an aqueous alkaline solution (i.e., at T = 318 K, t = 1 h) and subsequent selective fractionation with a 10/90 (v/v) acetone/water mixture. While the weight average molecular weight (MW) of lignin in comparison to the starting material was reduced by 82% after oxidation (T = 318 K, t = 1 h, clignin = 40 g L-1, cH2O2 = 80 g L-1, cNaOH = 2 mol L-1) and subsequent solvent fractionation (T = 298 K, t = 18 h, ccleavage product = 20 g L-1), the carboxyl group (-COOH) content increased from 1.29 mmol g-1 up to 2.66 mmol g-1. Finally, the successful scale-up of this whole process to 3 L scale led to gram amounts (14% yield) of oligomeric lignin fragments with a MW of 1607 g mol-1, a number average molecular weight (MN) of 646 g mol-1, a narrow polydispersity index of 3.0, and a high -COOH content of 2.96 mmol g-1. Application of these oligomeric lignin fragments in epoxy resins or as adsorbents is conceivable without further functionalization.


Assuntos
Peróxido de Hidrogênio/química , Lignina/química , Fracionamento Químico , Oxirredução
3.
Int J Legal Med ; 132(6): 1699-1712, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29882059

RESUMO

Fatal falls are frequent and seem to be an increasing problem in the elderly. Especially ground level falls (GLFs) and falls on or from stairs and steps (stairs falls) are worth examining for forensic classification and in order to improve the development of preventive measures. We retrospectively analyzed 261 fatal falls of elderly age 65 + years, which were autopsied at the Institute of Legal Medicine in Munich between 2008 and 2014. After careful screening, the sub-set of all 77 GLFs and 39 stairs falls were analyzed towards socio-demographic characteristics, fall circumstances, injuries, and circumstances of death. A subsequent analysis of GLF cases regarding the presence of proximal femur fractures (PFF) was performed. The injury pattern of the GLFs and the stairs falls clearly differ with a higher share of injuries to the lower extremities in the GLFs. However, the most severely injured body region was the head in both groups (62% of the stairs cases, 49% of the GLF cases). Alcohol as contributing to the fall was seen more frequently in the stairs falls. PFF were not seen in the stairs falls, but then in 18 GLF cases. Yet, for 17 among them (22% of 77), their hip fracture was the only serious injury leading to hospitalization and death. Only one GLF case was already found dead. This finding indicates a potential of avoiding up to 22% of the GLF fatalities by preventing hip fractures by optimized hip protectors or other measures, especially for the elderly aged 75 + years.


Assuntos
Acidentes por Quedas/mortalidade , Fraturas do Fêmur/epidemiologia , Acidentes por Quedas/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Consumo de Bebidas Alcoólicas/efeitos adversos , Consumo de Bebidas Alcoólicas/epidemiologia , Lesões Encefálicas/mortalidade , Doenças Cardiovasculares/mortalidade , Feminino , Alemanha/epidemiologia , Hospitalização/estatística & dados numéricos , Humanos , Escala de Gravidade do Ferimento , Masculino , Limitação da Mobilidade , Sistema de Registros , Estudos Retrospectivos , Fraturas Cranianas/mortalidade
4.
Int J Legal Med ; 131(4): 1023-1037, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28180986

RESUMO

Older traffic participants have higher risks of injury than the population up to 65 years in case of comparable road traffic accidents and further, higher mortality rates at comparable injury severities. Rib fractures as risk factors are currently discussed. However, death on scene is associated with hardly survivable injuries and might not be a matter of neither rib fractures nor age. As 60% of traffic accident fatalities are estimated to die on scene, they are not captured in hospital-based trauma registries and injury patterns remain unknown. Our database comprises 309 road traffic fatalities, autopsied at the Institute of Legal Medicine Munich in 2004 and 2005. Injuries are coded according to Abbreviated Injury Scale, AIS© 2005 update 2008 [1]. Data used for this analysis are age, sex, site of death, site of accident, traffic participation mode, measures of injury severity, and rib fractures. The injury patterns of elderly, aged 65+ years, are compared to the younger ones divided by their site of death. Elderly with death on scene more often show serious thorax injuries and pelvic fractures than the younger. Some hints point towards older fatalities showing less frequently serious abdominal injuries. In hospital, elderly fatalities show lower Injury Severity Scores (ISSs) compared to the younger. The number of rib fractures is significantly higher for the elderly but is not the reason for death. Results show that young and old fatalities have different injury patterns and reveal first hints towards the need to analyze death on scene more in-depth.


Assuntos
Escala Resumida de Ferimentos , Acidentes de Trânsito/mortalidade , Ferimentos e Lesões/mortalidade , Ferimentos e Lesões/patologia , Adolescente , Adulto , Idoso , Feminino , Alemanha/epidemiologia , Mortalidade Hospitalar , Humanos , Escala de Gravidade do Ferimento , Masculino , Pessoa de Meia-Idade , Pedestres/estatística & dados numéricos , Adulto Jovem
5.
Polymers (Basel) ; 11(9)2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31466239

RESUMO

Structural properties of resins based on epoxidized linseed oil (ELO) were investigated in reference to varying amounts of the hardener components methyltetrahydrophthalic anhydride (MTHPA), pyromellitic dianhydride (PMDA) and maleic acid (MA). This includes gel time and the Shore A and D hardness. The shortest gel time of 0.9 min and the highest Shore A and D hardness of 85 and 34 were found at a nMTHPA/nPMDA/nMA molar ratio of 8/1/8. To study the effect of the ELO mass on gel time and hardness, different masses of ELO (8, 10, 12, 14 and 16 g) were used, keeping the amount of the hardener system (4 g) (MTHPA, PMDA and MA) constant. With increased ELO mass, gel time increased while the Shore A and D hardness of the samples did not differ when up to 14 g ELO was applied. Substitution of petrol-based PMDA with biogenic compounds, specifically oxalic acid and citric acid, resulted in new bio-based epoxy resins with shorter gel times while maintaining hardness.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA