| 1. |
- Meuller, Bengt, et al.
(författare)
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Review of Spark Discharge Generators for Production of Nanoparticle Aerosols
- 2012
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Ingår i: Aerosol Science and Technology. - : Informa UK Limited. - 1521-7388 .- 0278-6826. ; 46:11, s. 1256-1270
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Forskningsöversikt (refereegranskat)abstract
- In the growing field of nanotechnology there is an increasing need to develop production methods for nanoparticles, especially methods that provide control and reproducibility. The spark discharge generator (SDG) is a versatile device for the production of nanoparticle aerosols. It can produce aerosol nanoparticles in the entire nanometer range (1-100 nm), and beyond. Depending on requirements, and the system used, these nanoparticles can be completely contamination free and composed of one or more materials. This provides a unique opportunity to create new materials on the nanoscale. Already in use in semiconductor, materials, health and environmental research, the SDG shows promise for yet more applications. If needed, particle production by the SDG could be scaled up using parallel generators facilitating continuous high-volume production of aerosol nanoparticles. Still, there is a surprisingly low knowledge of fundamental processes in the SDG. In this article we present a thorough review of the most common and relevant SDGs and the theory of their operation. Some possible improvements are also discussed.
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| 2. |
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| 3. |
- Edgren, M, et al.
(författare)
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Postoperative radiotherapy after prostatectomy can be associated with severe side effects.
- 2001
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Ingår i: Anticancer research. - 0250-7005. ; 21, s. 2231-
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Tidskriftsartikel (refereegranskat)abstract
- This retrospective study was initiated to evaluate the efficacy and side effects of post-prostatectomy external beam radiation therapy (XRT) with a short time interval between surgery and irradiation in patients with prostate adenocarcinoma. Sixteen patients were investigated. The overall results in this study were 3 deaths due to recurring disease and two relapses after an average follow-up of 60 months. Severe side effects were observed. Two patients required surgical intervention due to severe post-radiotherapy side effects. The reason for this could be the high dose delivered to peripheral organs and/or a too short time interval between surgery and postoperative XRT. The results of this study confirmed that postoperative XRT can improve local control frequency in prostate carcinomas. It is recommended that the time interval between surgery and postoperative radiotherapy should to be 3-6 month.
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| 4. |
- Heidsma, Charlotte M, et al.
(författare)
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International Validation of a Nomogram to Predict Recurrence after Resection of Grade 1 and 2 Nonfunctioning Pancreatic Neuroendocrine Tumors
- 2022
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Ingår i: Neuroendocrinology. - : S. Karger. - 0028-3835 .- 1423-0194. ; 112:6, s. 571-579
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Despite the low recurrence rate of resected nonfunctional pancreatic neuroendocrine tumors (NF-pNETs), nearly all patients undergo long-term surveillance. A prediction model for recurrence may help select patients for less intensive surveillance or identify patients for adjuvant therapy. The objective of this study was to assess the external validity of a recently published model predicting recurrence within 5 years after surgery for NF-pNET in an international cohort. This prediction model includes tumor grade, lymph node status and perineural invasion as predictors.METHODS: Retrospectively, data were collected from 7 international referral centers on patients who underwent resection for a grade 1-2 NF-pNET between 1992 and 2018. Model performance was evaluated by calibration statistics, Harrel's C-statistic, and area under the curve (AUC) of the receiver operating characteristic curve for 5-year recurrence-free survival (RFS). A sub-analysis was performed in pNETs >2 cm. The model was improved to stratify patients into 3 risk groups (low, medium, high) for recurrence.RESULTS: Overall, 342 patients were included in the validation cohort with a 5-year RFS of 83% (95% confidence interval [CI]: 78-88%). Fifty-eight patients (17%) developed a recurrence. Calibration showed an intercept of 0 and a slope of 0.74. The C-statistic was 0.77 (95% CI: 0.70-0.83), and the AUC for the prediction of 5-year RFS was 0.74. The prediction model had a better performance in tumors >2 cm (C-statistic 0.80).CONCLUSIONS: External validity of this prediction model for recurrence after curative surgery for grade 1-2 NF-pNET showed accurate overall performance using 3 easily accessible parameters. This model is available via www.pancreascalculator.com.
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| 6. |
- Kitano, M, et al.
(författare)
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Ischemia of rat stomach mobilizes ECL cell histamine
- 2005
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Ingår i: American Journal of Physiology: Gastrointestinal and Liver Physiology. - : American Physiological Society. - 1522-1547 .- 0193-1857. ; 288:5, s. 1084-1090
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Tidskriftsartikel (refereegranskat)abstract
- Microdialysis was used to study how ischemia-evoked gastric mucosal injury affects rat stomach histamine, which resides in enterochromaffin-like (ECL) cells and mast cells. A microdialysis probe was inserted into the gastric submucosa, and the celiac artery was clamped (30 min), followed by removal of the clamp. Microdialysate histamine was determined by enzyme-linked immunosorbent assay. In addition, we studied the long-term effects of ischemia on the oxyntic mucosal histidine decarboxylase activity in omeprazole-treated rats. Gastric mucosal lesions induced by the ischemia were enlarged on removal of the clamp. The microdialysate histamine concentration increased immediately on clamping (50-fold rise within 30 min) and declined promptly after the clamp was removed. In contrast, histidine decarboxylase activity of the ECL cells was lowered by the ischemia and returned to preischemic values 9 days later. Mast cell-deficient rats responded to ischemia-reperfusion much like wild-type rats with respect to histamine mobilization. Pretreatment with the irreversible inhibitor of histidine decarboxylase, alpha-fluoromethylhistidine, which is known to eliminate histamine from ECL cells, prevented the rise in microdialysate histamine. Pharmacological blockade of acid secretion (cimetidine or omeprazole) prevented the lesions induced by ischemia-reperfusion insult but not the mobilization of histamine. In conclusion, ischemia of the celiac artery mobilizes large amounts of histamine from ECL cells, which occurs independently of the gross mucosal lesions. The prompt reduction of the mucosal histidine decarboxylase activity in response to ischemia probably reflects ECL cell damage. The lesions develop not because of mobilization of histamine per se but because of ischemia plus reperfusion plus gastric acid.
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| 8. |
- Lennernäs, Bo, 1963, et al.
(författare)
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Postoperative radiotherapy after prostatectomy--a review
- 2003
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Ingår i: Scand J Urol Nephrol. - 0036-5599. ; 37:1, s. 10-5
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The management of prostate adenocarcinomas using postoperative irradiation is a controversial question. The purpose of this study was to review the literature on the subject. MATERIAL AND METHODS: A total of 417 articles dealing with postoperative radiotherapy after radical prostatectomy in English literature (1990-2002) were reviewed in aspects of effect on survival, time of irradiation, risk factors, dose and technique and side effects. RESULTS AND DISCUSSION: No randomised studies have been performed and therefore no definitive conclusive data can be made concerning the efficiency of the concept. However, postoperative radiotherapy appears to increase local control preferably in pT3/4 prostatic carcinomas with seminal vesicles involvement and/or positive margins and/or high Gleason score and high postoperative PSA level. It has not been shown to improve survival. Severe side effects are reported in a low frequency. However, postoperative irradiation can cause severe side effects and postoperative adjuvant/salvage treatments should be delivered earliest 3-6 months after surgery and the total dose delivered to the prostate bed should be 65-70 Gy. Postoperative radiotherapy induces improved local control in patients with positive surgical margins and in patients with a local relapse, preferably if the tumour is small (i.e. PSA <1-2 ng/mL).
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