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Perioperative anticoagulation in head and neck free flap reconstructions: Experience of an anticoagulative scheme and its modification.
No full textOBJECTIVES: Microvascular anastomoses in microvascular reconstructions induce rheological changes in the anastomosed vessels and are usually counteracted by anticoagulative medication. There is no regimen commonly agreed on. This study provides an easy to use anticoagulative regimen.
PATIENTS AND METHODS: Consecutive cases of either anticoagulative regimen between 2013 and 2018 that underwent microvascular reconstruction in the head and neck area were included in this retrospective study, resulting in 400 cases in total. Two different anticoagulative regimens were applied to 200 patients in each group: (a) intraoperatively administered unfractionated 5000 I.U. high molecular weight heparin (HMWH) and postoperatively low molecular weight heparin (LMWH, Enoxaparin) 1 mg/kg/body weight postoperatively and (b) intraoperatively LMWH 0.5 mg/kg/body weight as well as 12 h later and 1 mg/kg/body weight postoperatively.
RESULTS: The LMWH cohort showed fewer overall thromboembolic (8.5% vs. 11%; p = .40) and peripheral thrombotic events (1% vs. 3.5%; p = .18) and lung embolisms (3% vs. 4%; p = .59). The number of thromboses at the site of the anastomosis was equally distributed. In regard to flap-specific complications, LMWH was associated with a positive effect, in particular with respect to total flap losses (5% vs. 7%; p = .40) and wound-healing disorders (14.5% vs. 20%; p = .145).
CONCLUSION: Findings indicate that intra- and postoperatively administered LMWH as the only anticoagulative medication seems reliable in our clinical routine of head and neck free flap reconstructions
Deep-learning-based image quality enhancement of CT-like MR imaging in patients with suspected traumatic shoulder injury.
No full textPURPOSE: To evaluate the diagnostic performance of CT-like MR images reconstructed with an algorithm combining compressed sense (CS) with deep learning (DL) in patients with suspected osseous shoulder injury compared to conventional CS-reconstructed images.
METHODS: Thirty-two patients (12 women, mean age 46 ± 14.9 years) with suspected traumatic shoulder injury were prospectively enrolled into the study. All patients received MR imaging of the shoulder, including a CT-like 3D T1-weighted gradient-echo (T1 GRE) sequence and in case of suspected fracture a conventional CT. An automated DL-based algorithm, combining CS and DL (CS DL) was used to reconstruct images of the same k-space data as used for CS reconstructions. Two musculoskeletal radiologists assessed the images for osseous pathologies, image quality and visibility of anatomical landmarks using a 5-point Likert scale. Moreover, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated.
RESULTS: Compared to CT, all acute fractures (n = 23) and osseous pathologies were detected accurately on the CS only and CS DL images with almost perfect agreement between the CS DL and CS only images (κ 0.95 (95 %confidence interval 0.82-1.00). Image quality as well as the visibility of the fracture lines, bone fragments and glenoid borders were overall rated significantly higher for the CS DL reconstructions than the CS only images (CS DL range 3.7-4.9 and CS only range 3.2-3.8, P = 0.01-0.04). Significantly higher SNR and CNR values were observed for the CS DL reconstructions (P = 0.02-0.03).
CONCLUSION: Evaluation of traumatic shoulder pathologies is feasible using a DL-based algorithm for reconstruction of high-resolution CT-like MR imaging
Betriebsverhalten und Degradation von Materialien beim Einsatz von Wirbelschichtreaktoren in thermochemischen Energiespeichern
No full textThis thesis experimentally investigates critical aspects of thermochemical energy storage using CaO and Ca(OH)2 in a fluidized bed reactor. It reveals the dominance of reaction-related attrition effects and highlights the pivotal role of excess velocity for system design. Addressing material degradation, it stresses the need for enhanced source material pre-processing, to prolong system longevity. Finally, the thesis demonstrates a successful and scaleable make-up strategy, ensuring sustained operation by replacing degraded material across cycles. Challenges in defining stable operational points due to evolving bulk properties are outlined, but the material exchange approach offers a cost-effective solution for industrial-scale operations.Diese Arbeit erforscht thermochemische Energiespeicherung mit CaO und Ca(OH)2 in einem Wirbelschichtreaktor. Sie betont den starken Einfluss von reaktionsbedingtem Zerfall und Überschussgeschwindigkeit. Optimierungen in der Vorbehandlung des Materials verlängern die Nutzungsdauer. Die Studie präsentiert eine skalierbare Austauschstrategie für degradiertes Material im laufenden Betrieb. Herausforderungen bei der Stabilität der Betriebspunkte werden erläutert. Materialaustausch bietet kostengünstige Lösungen für Industrieanwendungen
A multitask deep learning model for simultaneous detection, segmentation and classification of bone tumors based on X-ray images
No full textDiese Arbeit, basierend auf einer klinischen Studie, thematisiert die Entwicklung eines Multitask Deep-Learning-Modells zur Klassifizierung von Knochentumoren als benigne oder maligne Läsion. Die Leistung des Modells in der Klassifizierung der Knochentumore als benigne oder maligne Läsion übertraf die Leistung der Assistenzärzt*innen für Radiologie und erreichte eine vergleichbar gute Leistung wie die der Fachärzt*innen für Radiologie mit muskuloskelettaler Expertise.This work, based on a clinical study, focuses on the development of a multitask deep learning model for the classification of bone tumors as benign or malignant lesions. The performance of the model in classifying bone tumors as benign or malignant lesions outperformed radiology residents and achieved a performance comparable to that of radiology specialists with musculoskeletal expertise
On the Severity of Self-Heating in FDSOI at Cryogenic Temperatures: In-depth analysis from Transistors to Full Processor
No full text3D Landslide Monitoring in High Spatial Resolution by Feature Tracking and Histogram Analyses Using Laser Scanners
No full textTriethylsilane introduced precursor engineering towards efficient and stable perovskite solar cells
No full text
Evaluating the photochemical reactivity of disinfection byproducts formed during seawater desalination processes
No full textNovel Tumor Organoid-Based Mouse Model to Study Image Guided Radiation Therapy of Rectal Cancer After Noninvasive and Precise Endoscopic Implantation.
No full textPURPOSE: Preoperative (neoadjuvant) radiation therapy (RT) is an essential part of multimodal rectal cancer therapy. Recently, total neoadjuvant therapy (TNT), which combines simultaneous radiochemotherapy with additional courses of chemotherapy, has emerged as an effective approach. TNT achieves a pathologic complete remission in approximately 30% of resected patients, opening avenues for treatment strategies that avoid radical organ resection. Furthermore, recent studies have demonstrated that anti-programmed cell death protein 1 immunotherapy can induce clinical complete responses in patients with specific genetic alterations. There is significant potential to enhance outcomes through intensifying, personalizing, and de-escalating treatment approaches. However, the heterogeneous response rates to RT or TNT and strategies to sensitize patients without specific genetic changes to immunotherapy remain poorly understood.
METHODS AND MATERIALS: We developed a novel orthotopic mouse model of rectal cancer based on precisely defined endoscopic injections of tumor organoids that reflect tumor heterogeneity. Subsequently, we employed endoscopic- and computed tomography-guided RT and validated rectal tumor growth and response rates to therapy using small-animal magnetic resonance imaging and endoscopic follow-up.
RESULTS: Rectal tumor formation was successfully induced in all mice after 2 organoid injections. Clinically relevant RT regimens with 5 × 5 Gy significantly delayed clinical signs of tumor progression and significantly improved survival. Consistent with human disease, rectal tumor progression correlated with the development of liver and lung metastases. Notably, long-term survivors after RT showed no evidence of tumor recurrence, as demonstrated by in vivo radiologic tumor staging and histopathologic examination.
CONCLUSIONS: Our novel mouse model combines orthotopic tumor growth via noninvasive and precise rectal organoid injection and small-animal RT. This model holds significant promise for investigating the effect of tumor cell-intrinsic aspects, genetic alterations of the host, and exogenous factors (eg, nutrition or microbiota) on RT outcomes. Furthermore, it allows for the exploration of combination therapies involving chemotherapy, immunotherapy, or novel targeted therapies