Management of germ cell tumors in children: Approaches to cure

The introduction of cisplatinum chemotherapy and current advances in the surgical treatment have resulted in a dramatic improvement of the prognosis of children with malignant germ cell tumors (GCT). Cisplatinum chemotherapy generally results in sufficient systemic tumor control, but local relapses may still occur in patients who did not receive adequate local treatment. Therefore, the therapeutic consideration must take into account age, primary site of the tumor, and its histology. In gonadal tumors, there is a high chance of primary complete resection since these tumors tend to be encapsulated, and particularly testicular GCT are often detected at a low tumor stage. In contrast, a primary complete resection may be impossible in large nongonadal tumors such as sacrococcygeal or mediastinal GCT. In these tumors, a neoadjuvant or pre-operative chemotherapy after clinical diagnosis by imaging and evaluation of tumor markers significantly facilitates complete resection on delayed surgery. In addition, the impact of chemotherapy on local tumor control may be enhanced by locoregional hyperthermia. In most intracranial GCT complete resection is impossible and may be associated with significant morbidity. Nevertheless, biopsy is essential for diagnosis in nonsecreting tumors. In intracranial GCT, radiotherapy significantly contributes to local tumor control, and doses are stratified according to histology. These general considerations have been integrated into national and international cooperative treatment protocols. In most current protocols, treatment is stratified according to an initial risk assessment that includes the parameters age, site, histology, stage, completeness of resection and the tumor markers alpha(1)-fetoprotein (AFP) and human choriogonadotropin (beta-HCG). With such modern protocols overall cure rates above 80% can be achieved. Moreover, the previously high-risk groups may now expect a favorable prognosis with this risk-adapted treatment, whereas an increasing number of low-risk patients are treated expectantly or with significantly reduced chemotherapy. As current biologic studies reveal distinct genetic patterns in childhood GCT, it can be expected that further combined clinical and genetic studies will be valuable for risk assessment of childhood GCT

Outer automorphism groups of metabelian groups

AbstractRecall that the outer automorphism group of a group G, denoted OutG, is the quotient group AutG/InnG. If M is any group, then there exists a torsion-free, metabelian group G with trivial center such that OutG≅M. This answers a problem in the Kourovka Notebook (Mazurov, Khukhro, Unsolved problems in group theory; the Kourovka Notebook, Russian Academy of Science, Novosibirsk, 1992)

Does a Joint Academic-Practitioner Review Reconcile Rigor and Relevance?

A substantial body of literature discusses the so-called rigor-relevance gap in management science and possible ways of overcoming it. A frequently advocated approach, in line with Gibbons, Limoges, Nowotny, Schwartz, and Trow’s “Mode 2” idea of creating “hybrid fora,” is the introduction of joint academic–practitioner review processes in management journals. In an empirical case study of one of the oldest management journals in the world, the authors show that the demands of academic and practitioner reviewers are hardly compatible, and, to some extent, inversely correlated. In contrast to other studies, here the authors show that the reason for the tension between academics and practitioners with regard to this issue does not lie in differences in the evaluation criteria of each group. Rather, the different worldviews of academics and practitioners lead to different interpretations of these criteria and a striking incongruence between the two groups’ ideas of practical relevance

Intrahepatic type II gall bladder perforation by a gall stone in a CAPD patient

<p>Abstract</p> <p>Introduction</p> <p>Perforation of the gall bladder represents a rare, but life-threatening complication of cholecystitis. Clinical presentation may vary between severe peritonism in acute perforation and absence of symptoms in subacute or chronic progression of perforation. Abdominal imaging like ultrasound or CT-scan are important tools for immediate diagnose of gall bladder perforation.</p> <p>Case presentation</p> <p>We report a case of a 30-year old female patient with end-stage kidney disease treated by continuous ambulatory peritoneal dialysis (CAPD) who was admitted to the emergency room with fever and mild abdominal pain. A type II gall bladder perforation by a solitary gall stone with development of a liver abscess was detected by abdominal ultrasound.</p> <p>Conclusion</p> <p>Gall bladder perforations are rare but have to be considered in patients with abdominal pain and fever. Abdominal ultrasound is a reliable tool to establish diagnosis.</p

Insights into intermetallic phases on pulse welded dissimilar metal joints

The Magnetic Pulse Welding (MPW) process has been developed to an industrially used joining method which is considered to be a fast, noncontact, clean and "cold" solid state welding process. Unlike fusion welding, the absence of direct heat during the welding cycle makes it possible to join dissimilar metals, for instance aluminium to copper or copper to steel, without noticeable detrimental metallurgical defects. This is very desirable, as today s industry lacks technologies to join often not fusion-weldable dissimilar materials effectively. However, current metallographic studies show that for many material combinations the formation of intermetallic seams in the joint region of magnetic pulse welds can not be completely avoided. Modern technical equipment for MPW is used to join aluminium with copper in order to study the microstructure and the intermetallic phases formed in the weld region in dependence of the processing parameters. The welds are analysed by means of metallographic and electron microscopic (SEM) methods. Relations between the parameters and the microstructures formed within the weld joints are shown. Based on the obtained results conclusions will be drawn with respect to the intermetallic phase formation process and the optimization of the weld microstructure and properties

A Latent Class Analysis of University Lecturers’ Switch to Online Teaching during the First COVID-19 Lockdown: The Role of Educational Technology, Self-Efficacy, and Institutional Support

The switch to emergency remote teaching (ERT) due to the first COVID-19 lockdown demanded a lot from university lecturers yet did not pose the same challenge to all of them. This study sought to explain differences among lecturers (n = 796) from universities in France, Germany, Switzerland, and the UK in their use of educational technology for teaching, institutional support, and personal factors. Guided by the Social Cognitive Theory (SCT), lecturers’ behavior (educational technology use), environment (institutional support), and personal factors (ERT self-efficacy, continuance intentions, and demographics) were examined. Latent class analysis was employed to identify different types of lecturers in view of educational technology use, while multinomial regression and Wald chi-square test were used to distinguish classes. The largest latent class were Presenters (45.6%), who focused on content delivery, followed by Strivers (22.1%), who strived for social interaction, Routineers (19.6%), who were ready for online teaching, and Evaders (12.7%), who evaded using technology for educational purposes. Both personal factors and perceived institutional support explained class membership significantly. Accordingly, Evaders were older, less experienced, and rarely perceived institutional support as useful. Routineers, the Evaders’ counterparts, felt most self-efficient in ERT and held the highest continuance intentions for educational technology use. This research suggests that universities engage lecturers in evidence-based professional development that seeks shared visions of digital transformation, networks and communities, and design-based researc

Stochastic optimization of a cold atom experiment using a genetic algorithm

We employ an evolutionary algorithm to automatically optimize different stages of a cold atom experiment without human intervention. This approach closes the loop between computer based experimental control systems and automatic real time analysis and can be applied to a wide range of experimental situations. The genetic algorithm quickly and reliably converges to the most performing parameter set independent of the starting population. Especially in many-dimensional or connected parameter spaces the automatic optimization outperforms a manual search.Comment: 4 pages, 3 figure