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Stephan Bechtel Rouven Schweitzer Maximilian Frey Ralf Busch Hans-Georg Herrmann 《Materials》2022,15(9)
Generating polymer–metal structures by means of additive manufacturing offers huge potential for customized, sustainable and lightweight solutions. However, challenges exist, primarily with regard to reliability and reproducibility of the additively generated joints. In this study, the polymers ABS, PETG and PLA, which are common in material extrusion, were joined to grit-blasted aluminum substrates. Temperature dependence of polymer melt rheology, wetting and tensile single-lap-shear strength were examined in order to obtain appropriate thermal processing conditions. Joints with high adhesive strength in the fresh state were aged for up to 100 days in two different moderate environments. For the given conditions, PETG was most suitable for generating structural joints. Contrary to PETG, ABS–aluminum joints in the fresh state as well as PLA–aluminum joints in the aged state did not meet the demands of a structural joint. For the considered polymers and processing conditions, this study implies that the suitability of a polymer and a thermal processing condition to form a polymer–aluminum joint by material extrusion can be evaluated based on the polymer’s rheological properties. Moreover, wetting experiments improved estimation of the resulting tensile single-lap-shear strength. 相似文献
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Ruys AT van Haelst S Busch OR Rauws EA Gouma DJ van Gulik TM 《World journal of surgery》2012,36(9):2179-2186
Background
Radical resection remains the only curative treatment for hilar cholangiocarcinoma (HCCA). Only a limited proportion of patients, however, are eligible for resection. The survival and prognostic factors of these patients are largely unknown. The aim of this study was to evaluate survival and prognostic factors in unresectable patients presenting with HCCA.Methods
We performed a cohort study of the denominator of HCCA patients seen in a tertiary referral center between March 2003 and March 2009. Demographics, treatment, pathology results, and survival were analyzed.Results
A total of 217 patients with suspected HCCA were identified. Ninety-five patients (40?%) underwent laparotomy, and in 57 (63?%) of these patients resection was performed. Overall median and 5-year survival of resected patients were 37?months and 43?%, respectively, as compared to 13?months and 7?% in unresectable patients. In unresectable patients, median survival was better in patients with locally advanced disease (16?months) as compared to patients with hepatic and extrahepatic metastases (5 and 3?months, p?0.001). Of the 160 unresectable patients, 17 (10?%) survived longer than 3?years.Conclusion
Of the patients presenting with HCCA in our center, 26?% proved resectable. The 7?% long-term survival rate of unresectable patients is remarkable and emphasizes the indolent growth of some of these tumors. Patients with metastases had a much worse prognosis with a median of 4?months. 相似文献56.
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Vaginal epithelial cells mature from basal to intermediate to superficial cells. Estrogen causes more superficial cells to be shed, and the proportion of exfoliated cell types is called a Maturation Index. This index helps clinicians manage dysfunctional bleeding, evaluate hormone change at menopause or prepuberty, and predict ovulation. 相似文献
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Glutamine Improves Innate Immunity and Prevents Bacterial Enteroinvasion During Parenteral Nutrition 下载免费PDF全文
Xinying Wang MD Joseph F. Pierre PhD Aaron F. Heneghan PhD Rebecca A. Busch MD Kenneth A. Kudsk MD 《JPEN. Journal of parenteral and enteral nutrition》2015,39(6):688-697
Background: Patients receiving parenteral nutrition (PN) are at increased risk of infectious complications compared with enteral feeding, which is in part explained by impaired mucosal immune function during PN. Adding glutamine (GLN) to PN has improved outcome in some clinical patient groups. Although GLN improves acquired mucosal immunity, its effect on innate mucosal immunity (defensins, mucus, lysozymes) has not been investigated. Methods: Forty‐eight hours following venous cannulation, male Institute of Cancer Research mice were randomized to chow (n = 10), PN (n = 12), or PN + GLN (n = 13) for 5 days. Small intestine tissue and luminal fluid were collected for mucin 2 (MUC2), lysozyme, cryptdin 4 analysis, and luminal interleukin (IL)–4, IL‐10, and IL‐13 level measurement. Tissue was also harvested for ex vivo intestinal segment culture to assess tissue susceptibility to enteroinvasive Escherichia coli. Results: In both luminal and tissue samples, PN reduced MUC2 and lysozyme (P < .0001, respectively) compared with chow, whereas GLN addition increased MUC2 and lysozyme (luminal, P < .05; tissue, P < .0001, respectively) compared with PN alone. PN significantly suppressed cryptdin 4 expression, while GLN supplementation significantly enhanced expression. IL‐4, IL‐10, and IL‐13 decreased significantly with PN compared with chow, whereas GLN significantly increased these cytokines compared with PN. Functionally, bacterial invasion increased with PN compared with chow (P < .05), while GLN significantly decreased enteroinvasion to chow levels (P < .05). Conclusions: GLN‐supplemented PN improves innate immunity and resistance to bacterial mucosal invasion lost with PN alone. This work confirms a clinical rationale for providing glutamine for the protection of the intestinal mucosa. 相似文献