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Two decades before his groundbreaking discovery of X-rays in 1895, Wilhelm Conrad Röntgen worked from 1872-1879 as an assistant, private lecturer, and finally associate professor at the University of Strasbourg, which was then part of the German Empire. This period was briefly interrupted in 1875/76 by Röntgen's first professorship at the Agricultural Academy in Hohenheim.Based on publications about W. C. Röntgen and research in a total of seven archives (Strasbourg, Hohenheim, Remscheid-Lennep, Würzburg), this work describes his professional career and private life during this period.In addition to his workplaces, a total of seven places of residence were identified for this period, four of which are described for the first time. A GPX track leading past the Strasbourg addresses is available for download. Archival material documenting his career during this period has been compiled. All of Röntgen's publications from this period are also listed. A detailed exchange of letters between Bertha Röntgen and a friend provides an insight into the Röntgen couple's private life.This early period in W. C. Röntgen's career forms the basis for his successful career with three subsequent full professorships, including his discovery of X-rays in 1895. · After the Franco-Prussian War of 1870/71, the University of Strasbourg was newly founded.. · The University of Strasbourg was heavily subsidized for reasons of power and cultural policy.. · Röntgen worked from 1872-1879 under the direction of the Chair of Physics, Professor August Kundt.. · Röntgen received his first professorship at the Hohenheim Agricultural Academy in 1875.. · In Strasbourg, Röntgen worked as an assistant, private lecturer, and finally as an associate professor.. · Rabe J, Busch U, Michels M et al. Wilhelm Conrad Röntgen's Strasbourg Years (1872-1879): W.C. Röntgen - Two Decades before the Discovery of X-rays (with GPX Track "Röntgen in Strasbourg"). Rofo 2025; 197: 1162-1175. Zwei Jahrzehnte vor seiner bahnbrechenden Entdeckung der Röntgenstrahlung im Jahr 1895 arbeitete Wilhelm Conrad Röntgen in der Zeit von 1872–1879 als Assistent, Privatdozent und schließlich außerordentlicher Professor an der damals zum Deutschen Reich gehörenden Universität Straßburg. Diese Periode wurde 1875/76 kurz durch Röntgens erste Professur an der Landwirtschaftlichen Akademie in Hohenheim unterbrochen.Auf der Grundlage der Publikationen über W. C. Röntgen und der Recherche in insgesamt sieben Archiven (Straßburg, Hohenheim, Remscheid-Lennep, Würzburg) beschreibt diese Arbeit den beruflichen Werdegang und sein Privatleben in dieser Zeit.Insgesamt konnten für diese Periode neben seinen Arbeitsplätzen sieben Wohnorte ermittelt werden, von denen vier erstmals beschrieben werden. Ein GPX-Track, der an den Straßburger Adressen vorbeiführt, wird zum Download angeboten. Es wurden Archivalien zusammengestellt, die seinen Werdegang in dieser Zeit dokumentieren. Zudem werden sämtliche Publikationen Röntgens aus dieser Periode gelistet. Ein ausführlicher Briefwechsel zwischen Bertha Röntgen und einer Freundin erlaubt Einblicke in das Privatleben des Ehepaars Röntgen.Diese frühe Periode in W. C. Röntgens Karriere bildet die Grundlage für seine erfolgreiche Karriere mit drei folgenden Ordinariaten, inclusive seiner Entdeckung der X-Strahlen im Jahr 1895. · Nach dem deutsch-französischen Krieg 1870/71 wurde die Universität Straßburg neu gegründet.. · Die Straßburger Universität wurde aus macht- und kulturpolitischen Gründen massiv gefördert.. · Röntgen arbeitete von 1872–1879 unter der Leitung des Lehrstuhlinhabers für Physik Prof. August Kundt.. · Röntgen erhielt 1875 seine erste Professur an der Landwirtschaftlichen Akademie Hohenheim.. · In Straßburg arbeitete Röntgen als Assistent, Privatdozent und schließlich außerordentlicher Professor.. · Rabe J, Busch U, Michels M et al. Wilhelm Conrad Röntgen’s Strasbourg Years (1872–1879): W.C. Röntgen – Two Decades before the Discovery of X-rays (with GPX Track “Röntgen in Strasbourg”). Rofo 2025; 197: 1162–1175.
The urinary excretion of kidney-specific marker proteins before and 120 hours after intravenous injection of either high- or low-osmolar contrast media (CM; diatrizoate, iopamidol 370) was monitored in patients after digital vascular imaging. Inclusion criteria for the randomized clinical study in a total of 40 patients (15 women, 25 men; mean age, 64.5 years) were at least 50 years of age or diabetes mellitus with normal creatinine concentration in serum. Compared with the control period, the elimination of tubular indicator enzymes alanine aminopeptidase, gamma-glutamyltranspeptidase, alkaline phosphatase, as well as of glomerular localized angiotensinase A was significantly higher in all patients after injection of the CM. The most significant differences were observed after 48 hours. In contrast, lysosomal N-acetyl-beta-D-glucosaminidase activity in urine specimens reacted less clearly and appears to be a less sensitive parameter in assessing CM nephrotoxicity. Elimination of brush border as well as of glomerular marker proteins was significantly lower after intravenous injection of low-osmolar CM iopamidol 370 (832 mOsm/kg) than after meglumine diatrizoate 76 (2100 mOsm/kg). In all 40 patients a significant decrease in creatinine clearance was observed; however, patients receiving diatrizoate had a significant decrease in creatinine clearance (period 0 versus 24 to 48 hours after CM), whereas patients after administration of iopamidol had not. No difference was found between creatinine clearance after 48 hours of CM injection within both groups of CM. Due to noninvasive parameters of kidney damage nonionic, low-osmolar CM are less nephrotoxic in potential risk patients, and should be preferred to conventional CM.
To investigate image quality and agreement of derived cardiac function parameters in a novel joint image reconstruction and segmentation approach based on disentangled representation learning, enabling real-time cardiac cine imaging during free-breathing. A multi-tasking neural network architecture, incorporating disentangled representation learning, was trained using simulated examinations based on data from a public repository along with cardiovascular magnetic resonance (CMR) scans specifically acquired for model development. An exploratory feasibility study evaluated the method on undersampled real-time acquisitions using an in-house developed spiral balanced steady-state free precession pulse sequence in eight healthy participants and five patients with intermittent atrial fibrillation. Images and predicted left ventricle segmentations were compared to the reference standard of electrocardiography (ECG)-gated segmented Cartesian cine with repeated breath-holds and corresponding manual segmentation. On a 5-point Likert scale, image quality of the real-time breath-hold approach and Cartesian cine was comparable in healthy participants (RT-BH: 1.99 ± 0.98, Cartesian: 1.94 ± 0.86, p = 0.052), but slightly inferior in free-breathing (RT-FB: 2.40 ± 0.98, p < 0.001). In patients with arrhythmia, both real-time approaches demonstrated favorable image quality (RT-BH: 2.10 ± 1.28, p < 0.001, RT-FB: 2.40 ± 1.13, p < 0.01, Cartesian: 2.68 ± 1.13). Intra-observer reliability was good (intraclass correlation coefficient = 0.77, 95% confidence interval [0.75, 0.79], p < 0.001). In functional analysis, a positive bias was observed for ejection fractions derived from the proposed model compared to the clinical reference standard (RT-BH mean: 58.5 ± 5.6%, bias: +3.47%, 95% confidence interval [-0.86, 7.79%], RT-FB mean: 57.9 ± 10.6%, bias: +1.45%, [-3.02, 5.91%], Cartesian mean: 54.9 ± 6.7%). The introduced real-time CMR imaging technique enables high-quality cardiac cine data acquisitions in 1-2 min, eliminating the need for ECG gating and breath-holds. This approach offers a promising alternative to the current clinical practice of segmented acquisition, with shorter scan times, improved patient comfort, and increased robustness to arrhythmia and patient non-compliance.
Four nonionic contrast media (iohexol, iopamidol, iopromide, and iosimide) are compared in this clinical study in their pharmacokinetic behavior with an ionic reference preparation (meglumine diatrizoate). At a dose of 1 ml of contrast medium per kilogram of body weight with approximately the same iodine content, virtually no differences could be established in the pharmacokinetic behavior. The osmotic diuresis of the ionic substance, compared with that of the nonionic preparations--implies an increased osmotic diuresis, thus, a lower maximal iodine concentration in the urine. The elderly patients included in this study have a reduced glomerular filtration rate, which in turn implies a prolonged half-life in the blood and a retarded renal elimination.
The liver and kidney tolerance of iopromide 370 in comparison to that of sodium meglumine diatrizoate 370 or iopamidol 370 in doses of 2 ml/kg body weight was examined in two controlled double-blind studies with intravenous digital subtraction angiography on the basis of enzyme assays in serum and urine. In patients with normal kidney function no changes were observed in the levels of the liver enzymes GPT, GOT, and gamma glutamyl transpeptidase (GGT) serum up to 72 hours after injection of iopromide or sodium meglumine diatrizoate. Among the kidney-specific enzymes, the excretion of GGT in urine increased after injection of iopromide and iopamidol. The maximum increase of GGT excretion was, however, statistically significantly lower in the group treated with iopromide than in the iopamidol group. Within 72 hours, the activities had been returned to the initial values in both groups.
The healthy thyroid can adapt to an iodine excess in many different ways. The autoregulation mechanisms may, however, fail in a diseased thyroid and severe hyperthyroidism may result. There must be autonomous portions of the thyroid functionally present to cause an iodine-induced hyperthyroidism. Retrospective and prospective studies, as well as animal experiments, were performed to establish further these pathophysiologic mechanisms. It was demonstrated that 15% of all cases of hyperthyroidism can be attributed to the use of iodine-containing contrast media. Furthermore, all contrast media exhibit a deiodinization during their intracorporeal retention time. The most frequent thyroid disorders, usually of a temporary nature, occur after choledochal contrast media. To some extent, these pathophysiologic processes can be reproduced in the animal model. Beyond this, the animal experimental studies show that it is possible to determine functionally autonomous portions of the thyroid by means of a dynamic thyroid scintigraph.
Iotrolan, a nonionic, hexaiodinated dimer, is an extremely hydrophilic compound (P = 0.005). Due to its larger Stokes' radius compared with monomeric compounds such as metrizamide, the diffusion time through membranes is extended. Iotrolan deforms erythrocytes only minimally. There is practically no binding to plasma proteins. The new contrast agent has been shown to exert a very limited effect on the complement system (in vitro); it does not inhibit lysozyme (a standard enzyme) in concentrations less than 100 mg I/ml. To inhibit activity of the enzyme collagenase, much higher concentrations of iotrolan than of metrizamide or iopamidol are needed and this could offer an advantage when used for diskography preceding diskolysis with collagenase. After a single intravenous injection in rats, iotrolan has an LD50 of 28.3 g I/kg - the best general tolerance known for water-soluble contrast media thus far. The superior tolerance of iotrolan compared with iohexol and iopamidol (p less than or equal to 0.05) in rats is statistically significant. On the basis of preclinical experience, iotrolan is a very promising contrast medium for intrathecal and intravascular use.
Due to the fact that Röntgen never reported the details of the discovery of his "new rays", he left the door open for speculative interpretations. As a contribution to a serious analysis of the history of Röntgen's discovery, this paper presents a previously unnoticed letter relating to an order of a number of very thin crystalline absorbers. The addressee is unfortunately unknown. The letter is dated November 15, 1895. Therefore, this letter must be considered to be the first well documented remark made by Röntgen after seeing the earliest indications of the new rays only one week earlier. The order seems to emphasize the role of a particular type of cathode ray tube developed by Philipp Lenard, Nobel Prize winner of 1905, and manufactured by the glassblower Louis Müller-Unkel in the discovery of the new radiation. It partly contradicts an analysis based on Röntgen's order book from Würzburg made by the author et al. some years ago. Completed by the document presented here, Röntgen's order correspondence allows some insight into Röntgen's intentions during this productive period. The autograph was found at Staatsbibliothek Berlin, Sammlung Darmstaedter, by the author.
The survival rate of human melanoma cells after X-ray irradiation, treatment with adriamycin derivatives and combined treatment with X-rays and adriamycin derivatives was measured by means of the colony formation test. After X-ray irradiation the melanoma cells showed a high resistance for cell survival. In all tests the Be11-cells were more resistant than MeWo-cells. On combined exposure especially with higher doses of adriamycin derivatives, both cell lines showed the interesting effect, that with increasing concentration the survival rate decreased whereas the D(o) increased. Aclacinomycin-A (ACM-A) and Pirarubicin reduced recovery processes after X-ray irradiation. Therefore Be11-cells showed a four times higher DMF (dosis modifying factor) after ACM-A-treatment than MeWo-cells. Low ACM-A-concentrations combined with low X-ray doses showed on both cell lines supraadditive effects. The effect of pirarubicin was in most of the tests only additive. Compared with ACM-A, pirarubicin was less cytotoxic, showed a larger therapeutic range, caused a smaller D(o) and Dq and had a supraadditive effect in low concentrations on both cell lines. For clinical combined therapy with patients ACM-A is probably better suited than pirarubicin.
The surface dose in megavoltage x-ray therapy can be modified using two different techniques: either varying the thickness of an absorber positioned directly on the surface of the patient or varying the distance to the surface of an absorber with constant thickness. Surface dose as a function of distance and absorber thickness has been measured at 4 MV and 8 MV x-rays. Both methods yield sufficiently and well-defined dose enhancements at the surface of the patient as desired clinically. The variation of the absorber-surface distance however has been proved to be the more simple and practicable method, offering the additional advantage of no contacting the patients skin.
Since the introduction of ionizing radiation as a treatment and diagnostic tool in humans, scientists have been trying to estimate its side effects and potential health risks. There is now ample evidence for the principal existence of a direct relationship between higher doses and the risks of side effects. Most of the uncertainties lie in the field of low-dose effects especially with respect to the risk of cancer induction. Low-dose effects are usually of relevance in diagnostic medicine while high-dose radiation effects are typically observed after radiotherapeutic treatment for cancer or after nuclear accidents. The current state of the "war of theories" may be summarized as follows: one group of scientists and health regulatory officials favors the hypothesis that there is no threshold dose, i.e. the linear-no-threshold hypothesis (LNT) of radiation which can be regarded as safe. On the contrary, the critics of this hypothesis suggest that the risks of doses below 50 mSv are not measurable or even of clinical relevance and are not adequately described by a linear dose-response relationship. The aim of this article is to summarize the major unresolved issues in this field. Arguments are presented why the validity of the LNT model in the low-dose range should be regarded as at least inconsistent and is thus questionable.
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In January 1896 experiments were made around the world with cathode-tubes to test Röntgen's paper "a new kind of rays". Mostly hands without pathological variations were X-rayed. At the same time in Vienna the clinical applications of X-rays were investigated. Two patients were successfully operated on after X-ray-examination. Remarkable for that time was an X-ray of an arteriogram of the arm of a dead person. It was made on 17th January 1896. The experiments with Lenard's cathode-tube were important for the discovery of X-rays. His experimentation was the inspiration for Röntgen's discovery of X-rays.
The early and reliable detection of breast cancer is often difficult with conventional mammography, especially within dense breast parenchyma. An alternative approach using x-rays are phase-sensitive imaging techniques, which are able to visualize the borders of tissues with different refraction indices with very high contrast. These phase contrast imaging techniques can generate projection images with much less glandular dose than conventional mammography. Even the acquisition of phase contrast CT data sets with an acceptable exposure dose is possible. As brilliant x-ray beams are required for phase contrast imaging, which up to now were only available at synchrotron facilities, these methods were restricted to only a few laboratories. However, with the advent of newly developed high intensity lasers which are also able to produce such radiation, a widespread and affordable use of this technique seems realistic. The further development of phase contrast imaging is funded by the excellence cluster MAP of the Munich universities.
Eponyms are derived from the name of a person. Eponymic verbs are rare compared to eponymic nouns and adjectives. The German Duden dictionary lists eponymic derivatives from the following persons: Amerigo (Vespucci), Bal(1)horn, Beckmesser, Boycott, Faraday, Galvani, Guillotin, Lumbeck, Lynch, Mendel, Morse, Pasteur und Roentgen. Only the verb "to roentgen" is formally identical to the name Roentgen. A computerized analysis of a newspaper that represents standard German (Frankfurter Allgemeine Zeitung from January 1, 1993 through March 7, 1995) proves that "to roentgen" (19x) ranges five in frequency of eponymic verbs of contemporary German-behind to boycott (363x), to ballhornize (33x), to lynch (30x), to americanize (29x).