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121.
To maintain the original distribution pattern of diffusible elements in biological samples, electron probe microanalysis is carried out with frozen hydrated bulk specimens and cryosections, analysed at temperatures below 130 K. Ice has a very low intrinsic conductivity at this working temperature and surface- and space-charging appears, when uncoated specimens are irradiated with non-penetrating electrons. Although coating with a grounded conductor abolishes the surface potential, the build-up of an internal space-charge field is possible, depending on the sample thickness and beam voltage used. Consequently, the geometry of the X-ray source volume and the spectral distribution of the emitted continuous and characteristic X-rays are affected. To simulate the situation for microanalysis of frozen hydrated specimens the charging process in electron irradiated ice is studied by recording simultaneous specimen currents from the top and bottom of ice layer preparations. The external currents yield information on the build-up of internal space-charge fields which result from the balance of charge injection, storage, and transport. Irradiation of uncoated bulk specimens with a finely focused beam results in the build-up of a space-charge field close to the surface, which causes a reduction of the depth of microprobe analysis. In coated bulk specimens the induced conductivity renders possible a current flow to the front electrode, thereby limiting the space-charge field. Sections with an effective rear electrode will not charge appreciably if the electron range is larger than about half the section thickness. 相似文献
122.
Walter Michaeli Dirk Opfermann Thomas Kamps 《The International Journal of Advanced Manufacturing Technology》2007,33(1-2):206-211
In micro systems technology, the process of micro assembly injection moulding is used for the generation of hybrid micro systems.
With this process, more functions are integrated in less space. In the field of medical technology, miniaturisation also means
new methods of treatment with fewer side effects on the patient. New cures are developed by the miniaturisation of medical
instruments, such as keyhole surgery. For detailed investigations a specific demonstration was developed to display the potential
of micro assembly injection moulding in medical science. This part consists of a carbon-fibre reinforced PEEK puncture needle,
which incorporates three lumens. The selected materials allow use of the needle during magnetic resonance imaging. In order
to attach additional equipment a plastic connector needs to be overmoulded on the needle. The investigations focus on the
injection moulding process by characterising the influences of temperature, moulding parameters and material combinations
on the resulting bond strength between needle and connector. 相似文献
123.
124.
Z. F. Tomashik V. G. Ivanits’ka V. N. Tomashik L. P. Shcherbak J. Franc P. Moravec P. Höschl J. Walter 《Inorganic Materials》2010,46(8):812-817
This paper examines the dissolution behavior of the (111)A, (111)B, (110), and (100) surfaces of CdTe single crystals in aqueous H2O2-HI-C6H8O7 (citric acid) solutions. We have determined the dissolution rate of the crystals as a function of temperature and solution
concentration, located the composition regions of polishing and selective etchants, and studied the microstructure and roughness
of surfaces polished with optimized etchants. The etching behavior of CdTe is shown to depend on its crystallographic orientation. 相似文献
125.
Syed HUSSAIN Walter PIERING Tayyab MOHYUDDIN Mohammad SALEH Yong-Ran ZHU Mary HANAN Eric COHEN 《Hemodialysis international. International Symposium on Home Hemodialysis》2009,13(2):205-214
Outcome of acute renal failure (ARF) and use of continuous renal replacement therapy (CRRT) have shown a consistently high mortality. (1) Evaluate the short-term patient survival. (2) Evaluate dialysis-free survival. (3) Evaluate risk factors associated with overall survival and the continued need for intermittent dialysis. We identified adults (≥18 years) needing CRRT, treated in the critical care units of Froedtert Medical and Lutheran Hospital from January 1, 2003 till December 31, 2005. Patients were divided into two major groups needing CRRT, end stage renal disease (ESRD) (chronic dialysis) and non-ESRD with ARF. Continuous renal replacement therapy was performed with an average of 2 L replacement fluid exchanges/h. Sigma stat software was used for analysis. Comparison was done for noncontinuous variables by chi-square and t test for categorical and continuous variables, respectively. A total of 110 (ESRD 24/non-ESRD 86) patients received CRRT during study period. Over all in-hospital mortality among non-ESRD patients was 63% vs. 46% for ESRD. Among non-ESRD patients who survived, 47% needed intermittent hemodialysis on intensive care unit discharge and 28% continued to need hemodialysis at last follow-up. Among non-ESRD patients alive at discharge, those who were dialysis dependent on last follow-up were older (64.5) than those who did not require dialysis on last follow-up (58.4) P=0.347. Non-ESRD patients who died were in the hospital for an average of 17.5 days compared with 29 days for those who were discharged from the hospital. Patients with ARF needing CRRT have high in-hospital mortality. A significant percentage of patients remained dialysis dependant on last follow-up. 相似文献
126.
Ramona Erber Miriam Angeloni Robert Sthr Michael P. Lux Daniel Ulbrich-Gebauer Enrico Pelz Agnes Bankfalvi Kurt W. Schmid Robert F. H. Walter Martina Vetter Christoph Thomssen Doris Mayr Frederick Klauschen Peter Sinn Karl Sotlar Katharina Stering Albrecht Stenzinger Marius Wunderle Peter A. Fasching Matthias W. Beckmann Oliver Hoffmann Rainer Kimmig Nadia Harbeck Rachel Wuerstlein Fulvia Ferrazzi Arndt Hartmann 《International journal of molecular sciences》2022,23(15)
In intermediate risk hormone receptor (HR) positive, HER2 negative breast cancer (BC), the decision regarding adjuvant chemotherapy might be facilitated by multigene expression tests. In all, 142 intermediate risk BCs were investigated using the PAM50-based multigene expression test Prosigna® in a prospective multicentric study. In 119/142 cases, Prosigna® molecular subtyping was compared with local and two central (C1 and C6) molecular-like subtypes relying on both immunohistochemistry (IHC; HRs, HER2, Ki-67) and IHC + tumor grade (IHC+G) subtyping. According to local IHC, 35.4% were Luminal A-like and 64.6% Luminal B-like subtypes (local IHC+G subtype: 31.9% Luminal A-like; 68.1% Luminal B-like). In contrast to local and C1 subtyping, C6 classified >2/3 of cases as Luminal A-like. Pairwise agreement between Prosigna® subtyping and molecular-like subtypes was fair to moderate depending on molecular-like subtyping method and center. The best agreement was observed between Prosigna® (53.8% Luminal A; 44.5% Luminal B) and C1 surrogate subtyping (Cohen’s kappa = 0.455). Adjuvant chemotherapy was suggested to 44.2% and 88.6% of Prosigna® Luminal A and Luminal B cases, respectively. Out of all Luminal A-like cases (locally IHC/IHC+G subtyping), adjuvant chemotherapy was recommended if Prosigna® testing classified as Prosigna® Luminal A at high / intermediate risk or upgraded to Prosigna® Luminal B. 相似文献
127.
Alessandro Salvucci Patrick E. Longhi Sergio Colangeli Walter Ciccognani Antonio Serino Ernesto Limiti 《国际射频与微波计算机辅助工程杂志》2019,29(9)
Low‐noise amplifier (LNA) designers often struggle to simultaneously satisfy gain, noise, stability, and I/O matching requirements. In this article, a novel design technique, tailored for two‐stage low‐noise amplifiers, is presented. The proposed design method is completely deterministic and exploits inductive source degeneration to obtain a two‐stage LNA featuring perfect input and output match together with low noise figure (NF) and a pre‐determined gain, including stability analysis. A novel flowchart is provided together with the corresponding design chart that contains gain, matching, and stability information, therefore addressing all key figures‐of‐merit of a linear amplifier. The design chart is easily implementable in commercial Electronic Design Automation software, to aid designers in the difficult task of selecting the appropriate source degeneration inductor value. The noise performance, on the other hand, is the best possible since the matching networks are designed to provide the input of the two Field Effect Transistors with the optimum termination for noise. The design method is validated with two separate test vehicles operating respectively at Ka‐band (26.5‐31.5 GHz) and K‐band (20.0‐24.0 GHz). The realized Monolithic Microwave Integrated Circuits exhibit 18 dB gain for both versions, NF of 1.5 and 1.2 dB, respectively for the Ka‐band and K‐band version. Input and output matching are typically better than 12 and 15 dB. 相似文献
128.
Mario Pukall Christian Kästner Walter Cazzola Sebastian Götz Alexander Grebhahn Reimar Schröter Gunter Saake 《Software》2013,43(2):153-185
Software is changed frequently during its life cycle. New requirements come, and bugs must be fixed. To update an application, it usually must be stopped, patched, and restarted. This causes time periods of unavailability, which is always a problem for highly available applications. Even for the development of complex applications, restarts to test new program parts can be time consuming and annoying. Thus, we aim at dynamic software updates to update programs at runtime. There is a large body of research on dynamic software updates, but so far, existing approaches have shortcomings either in terms of flexibility or performance. In addition, some of them depend on specific runtime environments and dictate the program's architecture. We present JavAdaptor , the first runtime update approach based on Java that (a) offers flexible dynamic software updates, (b) is platform independent, (c) introduces only minimal performance overhead, and (d) does not dictate the program architecture. JavAdaptor combines schema changing class replacements by class renaming and caller updates with Java HotSwap using containers and proxies. It runs on top of all major standard Java virtual machines. We evaluate our approach's applicability and performance in non‐trivial case studies and compare it with existing dynamic software update approaches. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
129.
Type 2 diabetes mellitus (T2DM) can result in microvascular complications such as neuropathy, retinopathy, nephropathy, and cerebral small vessel disease, and contribute to macrovascular complications, such as heart failure, peripheral arterial disease, and large vessel stroke. T2DM also increases the risks of depression and dementia for reasons that remain largely unclear. Perturbations in the cytochrome P450-soluble epoxide hydrolase (CYP-sEH) pathway have been implicated in each of these diabetes complications. Here we review evidence from the clinical and animal literature suggesting the involvement of the CYP-sEH pathway in T2DM complications across organ systems, and highlight possible mechanisms (e.g., inflammation, fibrosis, mitochondrial function, endoplasmic reticulum stress, the unfolded protein response and autophagy) that may be relevant to the therapeutic potential of the pathway. These mechanisms may be broadly relevant to understanding, preventing and treating microvascular complications affecting the brain and other organ systems in T2DM. 相似文献
130.
Daniel H. Mendelsohn Katja Schnabel Andreas Mamilos Samuel Sossalla Steffen Pabel Georg Daniel Duerr Karsten Keller Volker H. Schmitt Friedrich Barsch Nike Walter Ronald Man Yeung Wong Thaqif El Khassawna Tanja Niedermair Volker Alt Markus Rupp Christoph Brochhausen 《International journal of molecular sciences》2022,23(9)
Mitochondria play a crucial role in cell physiology and pathophysiology. In this context, mitochondrial dynamics and, subsequently, mitochondrial ultrastructure have increasingly become hot topics in modern research, with a focus on mitochondrial fission and fusion. Thus, the dynamics of mitochondria in several diseases have been intensively investigated, especially with a view to developing new promising treatment options. However, the majority of recent studies are performed in highly energy-dependent tissues, such as cardiac, hepatic, and neuronal tissues. In contrast, publications on mitochondrial dynamics from the orthopedic or trauma fields are quite rare, even if there are common cellular mechanisms in cardiovascular and bone tissue, especially regarding bone infection. The present report summarizes the spectrum of mitochondrial alterations in the cardiovascular system and compares it to the state of knowledge in the musculoskeletal system. The present paper summarizes recent knowledge regarding mitochondrial dynamics and gives a short, but not exhaustive, overview of its regulation via fission and fusion. Furthermore, the article highlights hypoxia and its accompanying increased mitochondrial fission as a possible link between cardiac ischemia and inflammatory diseases of the bone, such as osteomyelitis. This opens new innovative perspectives not only for the understanding of cellular pathomechanisms in osteomyelitis but also for potential new treatment options. 相似文献