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Institution

Leibniz University of Hanover

EducationHanover, Niedersachsen, Germany
About: Leibniz University of Hanover is a education organization based out in Hanover, Niedersachsen, Germany. It is known for research contribution in the topics: Finite element method & Population. The organization has 14283 authors who have published 29845 publications receiving 682152 citations.


Papers
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Journal ArticleDOI
15 Nov 1992-Cancer
TL;DR: This first German soft tissue sarcoma (STS) study, CWS‐81, 344 patients younger than 19 years of age who had previously untreated soft tissue Sarcoma were studied, and there were 218 patients with chemosensitive STS who could be studied for a minimum potential follow‐up time of 6 years.
Abstract: Background In the first German soft tissue sarcoma (STS) study, CWS-81, 344 patients younger than 19 years of age who had previously untreated soft tissue sarcoma were studied. For this analysis, there were 218 patients with chemosensitive STS (Group A: rhabdomyosarcoma [RMS], synovial sarcoma, extraosseous Ewing sarcoma, leiomyosarcoma, undifferentiated sarcoma, and malignant peripheral neuroectodermal tumor) who could be studied for a minimum potential follow-up time of 6 years. Methods A staging system based on the postoperative extent of the disease was used. The chemotherapy for Stage I-III disease consisted of vincristine, dactinomycin, cyclophosphamide, and doxorubicin (VACA). Patients with metastatic disease and patients with Stage III disease who failed to respond to VACA were given ifosfamide instead of cyclophosphamide. The definitive procedure for local tumor control (either no radiation exposure, 40 Gy, or 50 Gy) for patients with Stage II-III disease depended on the tumor status at second-look surgery after 16 weeks of chemotherapy. Results The rates of disease-free survival (DFS) and survival after 5 years was 61% +/- 4% and 57% +/- 4%, respectively, in group A; for patients with nonmetastatic tumors (Stages I-III), the rates were 69% +/- 4% and 72% +/- 4, respectively. Patients with nonmetastatic rhabdomyosarcoma had a similar prognosis: the survival rate was 73% +/- 4%, and the DFS rate was 68% +/- 4%. There was no difference in prognosis between patients with Stage I and and those with Stage II disease (DFS rate, 88% +/- 5% and 88% +/- 6%, respectively). The DFS rate for patients with Stage III disease was 54% +/- 5% and for those with Stage IV, 11% +/- 5%. Lack of local tumor control was the primary cause of therapy failure: 10% of patients with localized disease did not achieve complete remission, whereas 18% who were in complete remission experienced local relapse. The most important prognostic factors were tumor size (P = 0.005) and the degree of tumor regression after primary chemotherapy (P = 0.007). The prognosis also differed according to primary site: paratesticular tumors had the best prognosis, whereas tumors located in the parameningeal regions of the head and neck had the worst prognosis (DFS rate, 96% +/- 4% versus 49% +/- 7%, respectively). Conclusions The following conclusions were drawn from the CWS-81 study: (1) intensive chemotherapy (VACA for 35 weeks) provides long-term control for most patients with Stage I-II disease; (2) patients with primary unresectable tumors (i.e., Stage III) who achieve complete remission with chemotherapy alone have the same prognosis as patients with postoperative disease of Stages I and II; (3) tumor size and the degree of tumor regression after primary chemotherapy influence outcome and thus can be used as a basis for risk-adapted therapy.

123 citations

Journal ArticleDOI
TL;DR: The 3D metal-organic framework (MOF) structure UiO-66, featuring triangular pores of approximately 6 Å, has been successfully prepared as a thin supported membrane layer with high crystallographic orientation on ceramic α-Al2O3 supports and a multilayer composite is prepared.
Abstract: The 3D metal–organic framework (MOF) structure UiO-66 [Zr6O4(OH)4(bdc)6], featuring triangular pores of approximately 6 A, has been successfully prepared as a thin supported membrane layer with high crystallographic orientation on ceramic α-Al2O3 supports. The adhesion of the MOF layer to the ceramic support was investigated in different taxing conditions. Furthermore, by coating this UiO-66 membrane with a thin polyimide (Matrimid) top layer, we prepared a multilayer composite. Said membranes have been evaluated in the separation of hydrogen (H2) from different binary mixtures at room temperature. H2 as the smallest molecule (2.9 A) should pass the UiO-66 membrane preferably since the kinetic diameters of all the other gases under study are larger. The gas mixture separation factors for the neat UiO-66 membrane were indeed found to be H2/CO2 = 5.1, H2/N2 = 4.7, H2/CH4 = 12.9, H2/C2H6 = 22.4, and H2/C3H8 = 28.5. The coating with Matrimid led to a sharp cutoff for gases with kinetic diameters greater than ...

123 citations

Journal ArticleDOI
TL;DR: The gas-separation performance of a 2D laminated membrane was improved by its partial self-conversion to metal-organic frameworks, ultimately leading to a remarkably enhanced H2 /CH4 separation factor and H2 permeance.
Abstract: Separation methods based on 2D interlayer galleries are currently gaining widespread attention. The potential of such galleries as high-performance gas-separation membranes is however still rarely explored. Besides, it is well recognized that gas permeance and separation factor are often inversely correlated in membrane-based gas separation. Therefore, breaking this trade-off becomes highly desirable. Here, the gas-separation performance of a 2D laminated membrane was improved by its partial self-conversion to metal–organic frameworks. A ZIF-8-ZnAl-NO3 layered double hydroxide (LDH) composite membrane was thus successfully prepared in one step by partial conversion of the ZnAl-NO3 LDH membrane, ultimately leading to a remarkably enhanced H2/CH4 separation factor and H2 permeance.

123 citations

Journal ArticleDOI
TL;DR: A tensor network method is presented that can find the steady state of 2D driven-dissipative many-body models, based on the intuition that strong dissipation kills quantum entanglement before it gets too large to handle.
Abstract: Understanding dissipation in 2D quantum many-body systems is an open challenge which has proven remarkably difficult. Here we show how numerical simulations for this problem are possible by means of a tensor network algorithm that approximates steady states of 2D quantum lattice dissipative systems in the thermodynamic limit. Our method is based on the intuition that strong dissipation kills quantum entanglement before it gets too large to handle. We test its validity by simulating a dissipative quantum Ising model, relevant for dissipative systems of interacting Rydberg atoms, and benchmark our simulations with a variational algorithm based on product and correlated states. Our results support the existence of a first order transition in this model, with no bistable region. We also simulate a dissipative spin 1/2 XYZ model, showing that there is no re-entrance of the ferromagnetic phase. Our method enables the computation of steady states in 2D quantum lattice systems.

123 citations

Journal ArticleDOI
TL;DR: The authors examined the role of committees as strategic practice during the implementation of personnel development in a public administration and found that the interaction between the management levels is not only organized in formal committees where the middle managers undertake strategic initiatives and the strategic context is set by the senior managers.
Abstract: This longitudinal qualitative study examined the role of committees as strategic practice during the implementation of personnel development in a public administration. The results show that the interaction between the management levels is not only organized in formal committees where the middle managers undertake strategic initiatives and the strategic context is set by the senior managers. Rather, the middle managers and the senior managers organize the discussion on strategic issues in informal interactions around committees. These close informal interactions can be understood as a strategic conversation that entails the micro-mechanisms of generating an understanding, aligning towards an issue and making prearrangements which give support for the flow of discussion. The findings show that the strategic conversations are beneficial within shaping strategy as they frame the committee as strategic practice and enable the strategic context to be reshaped and redefined.

123 citations


Authors

Showing all 14621 results

NameH-indexPapersCitations
Hyun-Chul Kim1764076183227
Peter Zoller13473476093
J. R. Smith1341335107641
Chao Zhang127311984711
Benjamin William Allen12480787750
J. F. J. van den Brand12377793070
J. H. Hough11790489697
Hans-Peter Seidel112121351080
Karsten Danzmann11275480032
Bruce D. Hammock111140957401
Benno Willke10950874673
Roman Schnabel10858971938
Jan Harms10844776132
Hartmut Grote10843472781
Ik Siong Heng10742371830
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
2023221
2022520
20212,280
20202,210
20192,105
20181,959