Publications by authors named "Steudel A"

In this paper, we show that both continuous phase transitions of liquid water, the liquid-gas and the liquid-liquid, can be articulated within a single thermodynamic analytical formalism. This result follows from a combination of the two-liquid model (TLM), recently confirmed for water, with the idea of a thermal-dependent excluded volume, , concept introduced by van der Waals, in his famous state equation. Starting from the fundamentals of thermodynamics, it will be shown that the TLM naturally leads to the idea of an extensive thermal-dependent that acts as a parameter of the sample thermodynamic potentials.

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Polyacrylamide (PAM) and its derivatives are the most commercially available water-soluble polymers and are frequently used for the production of clay-polymer composites. The characterization of their thermal behavior and decomposition was carried out mainly under reduced conditions by using N, He or Ar gas flow. The object of this study was to investigate the thermal decomposition of cationic (PAMCl), nonionic (PAM°), and anionic (NaPAM) polyacrylamide under synthetic air (SynA) in detail using a thermogravimetry/differential scanning calorimetry (TG/DSC) system connected to a quadrupole mass spectrometer (MS).

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The clay mineral montmorillonite is a member of the phyllosilicate group of minerals, which has been detected on martian soil. Montmorillonite catalyzes the condensation of activated monomers to form RNA-like oligomers. Extent of catalysis, that is, the yield of oligomers, and the length of the longest oligomer formed in these reactions widely varies with the source of montmorillonite (i.

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In this paper, we will study theoretically and experimentally the anisotropy of the thermal diffusivity in nematic liquid crystals. We will show that the Baalss-Hess conformal transformation [D. Baalss and S.

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Purpose: Evaluation of the diagnostic value of the imaging modalities computed tomography (CT), magnetic resonance imaging (MRI), and thoracic sonography in the preoperative staging of malignant pleural mesothelioma.

Materials And Methods: The diagnostic accuracy of CT (n = 41), MRI (n = 24), and thoracic sonography (n = 37) were evaluated in 51 patients with histologically proven diffuse malignant pleural mesothelioma. Values of sensitivity, specificity, positive and negative predictive values, and accuracy were calculated for the assessment of the diaphragm, lung, thoracic wall, pericardial wall, myocardium, and (retro)peritoneal space.

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Background: Bone marrow is a common site of metastases in patients with small cell lung carcinoma (SCLC) and female breast carcinoma (FBC). Metastatic bone marrow involvement is found in approximately 50% of SCLC patients and up to 85% of FBC patients at autopsy. Initial staging procedures detect malignant bone marrow lesions in only 2-30% of patients with these tumors.

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Purpose: Evaluation of percutaneously implanted covered stents in acute vascular bleeding as therapeutic alternative to conventional surgical treatment.

Materials And Methods: 8 patients aged 26 to 83 years with acute vascular lesions caused by traumas, and subsequent haemorrhage, were transferred to our department. Because of general inoperability or difficult surgical access, interdisciplinary evaluation favoured an interventional treatment.

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The aim of this work was to compare MR imaging and CT in the detection of renal masses and in the differential diagnosis between benign and malignant lesions. In 33 patients with 54 renal lesions CT and MR images were evaluated by four readers with regard to tumor detection and characterization using a receiver-operating-characteristics (ROC) analysis. The MRI protocol consisted of a T1-weighted spin-echo (SE) sequence (TR/TE: 300/10 ms) before and after contrast administration and a heavily T2-weighted turbo-SE (TSE) sequence (TR/TE: 5500/150 ms).

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In clinical practice, Alzheimer's disease (AD), multi-infarct Dementia (MID) and depression are often difficult to differentiate and may coexist. This study reports the findings of CT and MRI focused on hippocampal atrophy (HA). Quantitative volumetric MRI measurements of the hippocampus showed a reduced volume in AD patients compared to normal controls with no overlap.

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Purpose: To evaluate new pulse sequences (turbo-spin-echo [TSE] and turbo-field-echo [TFE] sequences) for study protocol optimisation and to assess the role of MRI in the differential diagnosis of renal tumours.

Methods: In six volunteers MRI of the kidney was performed at 0.5 T using a conventional T2 weighted spin-echo (SE) sequence (TR/TE 1800/90 ms) and three different TSE sequences (TR 1800-5000 ms, TE 90-150 ms).

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Purpose: Evaluation of intraarterial cancer treatment in recurrent pelvic tumors, which were resistent to other treatment modalities.

Patients And Methods: Ninety-seven patients suffering from pelvic recurrences originating from bladder (n = 40), rectum (n = 19), cervix (n = 21) oder other organs (n = 17) were treated by intraarterial chemotherapy (111 times) or transcatheter embolisation (52 times).

Results: Less than 20% of our patients had remission of the tumor burden but tumor symptoms (especially pain and bleeding) could be controlled in 35 to 87% of the patients.

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Purpose: To determine whether dynamic MR mammography is possible on midfield systems without loss of diagnostic sensitivity when compared to the standard highfield technique.

Materials And Methods: 42 consecutive patients were examined twice: Once using the standard dynamic 2D gradient echo technique at 1.5 T; a second examination was performed on a 0.

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DIL filters were permanently inserted through the cubital vein, using a 7-F catheter, in 15 patients and were followed up for six months in 12 patients. One filter could not be opened and 4 others were only partly open. Clinically there were no recurrences of pulmonary emboli.

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The aim of this study was the evaluation of spiral computed tomography (Spiral-CT), multiplane transesophageal echocardiography (multiplane TEE) and magnetic resonance imaging (MRI) in the diagnosis of thoracic aortic dissection. 41 patients were examined: 30 with clinically suspected acute aortic dissection (14 Stanford A, 7 Stanford B), 11 with aortic repair (7/11 with persisting distal dissection). In 14 patients there was involvement of the supraaortic vessels.

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The clinical and radiological findings of 5 patients with a total of 7 hepatobiliary cystadenomas are reported. In all cases sonography and computed tomography were performed, in three cases angiography was carried out, and in one case magnetic resonance imaging was used. On sonography and computed tomography hepatobiliary cystadenomas exhibit relatively typical findings as a multicystic, space-occupying lesion with septation and papillary mucosal nodes; hence the diagnosis can be made preoperatively in most cases.

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The value of rapid T1- and T2-weighted fast field (T1-FFE, T2-FFE) gradient-echo sequences and T2 weighted turbo-spin echo (TSE) sequences in the diagnosis of focal liver lesions using 0.5 Tesla was compared with conventional spin-echo sequences (SE). Amongst 88 liver lesions T1-SE sequences showed 98%, T2-TSE sequences showed 92%, T2-SE sequence showed 84%, T1-FFE sequence showed 78% and T2-FFE sequence showed 69%.

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Nitinol stents were used in ten patients as palliative treatment for carcinoma of the esophagus and the cardia. Following insertion of the stent the severity of dysphagia decreased on average from 3.2 to 1.

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46 patients with recently diagnosed carcinoma of the breast were included in a prospective comparative study of MRI and bone marrow scintigraphy. The aim of the study was to compare these procedures within a histologically unified patient collective. It was shown that MRI was superior to bone marrow scintigraphy in respect of sensitivity (92% vs 58%) and specificity (97% vs.

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MRT is of considerable significance in the investigation of epilepsy because of its ability to render soft tissue contrast for the demonstration of structural lesions. The present retrospective study consists of an analysis of MRT findings in operatively confirmed, circumscribed temporal tumours and in hippocampal sclerosis. The examinations were performed under standard conditions using T1- and T2-weighted spin-echo sequences of the head and coronal T2-weighted gradient-echo sequences of the brain stem.

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17 patients with hemophilic arthropathy of the knee joint were studied with static and dynamic MRT before and after i.v. bolus injection of Gadolinium-DTPA (0.

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Primary idiopathic amyloidosis may be a diagnostic problem because of its low incidence and its variable manifestations. The clinical and radiographic findings in a patient with accidentally discovered primary amyloidosis of the lung are presented. The extensive mediastinal and hilar lymph-node enlargement was striking.

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