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101.
Brian a. Maurer 《Evolutionary ecology》1998,12(8):935-944
Given that body mass evolves non-randomly in birds, it is important to ask what factors might be responsible. One suggestion is that the rate at which individuals turn resources into offspring, termed reproductive power, might explain this non-randomness. This is because, in mammals, the body mass with the highest reproductive power is the most common (modal) one. Reproductive power was estimated for birds from data on energetic content of eggs and population productivity. According to the formulation of Brown et al. (1993), reproductive power is composed of two component processes: acquisition (acquiring resources and storing them in reproductive biomass) and conversion (converting reproductive biomass into offspring). As with mammals, estimates of reproductive power indicate that the most common body mass in birds is also the body mass that maximizes reproductive power. The relationship between reproductive power and diversity is different for species smaller than this modal body mass when compared to those that are larger. The relationship of body mass and reproductive power is different between birds and mammals in two ways: (1) the body mass that maximizes reproductive power is smaller in birds (33g) than in mammals (100g), and (2) mammals generate more reproductive power than an equivalent-sized bird. Reproductive power is determined primarily by acquisition in small birds and mammals, while it is determined by conversion in the largest birds and mammals. It is likely that reproductive power is closely tied to the evolution and diversification of body masses because it constrains the ways in which traits affecting fitness can evolve. 相似文献
102.
Ingo Ott Konrad Kowalski Ronald Gust Jörg Maurer Philipp Mücke Rainer F. Winter 《Bioorganic & medicinal chemistry letters》2010,20(3):866-869
Two ethylene linked binuclear mixed ferrocene/ruthenium complexes were biologically investigated in comparison to structurally related mononuclear ferrocene or ruthenium species with styryl substituents or ligands. Results indicated that the electron distribution (but not the redox potential), cellular uptake and (to some minor extent) anti-estrogenic effects were the key contributors to antiproliferative effects observed in tumor cell lines. 相似文献
103.
Peter Maurer Marcus S Kriwalsky Rafael Block Veras J?rg Brandt Christian Heiss 《Biomedizinische Technik》2007,52(5):351-355
INTRODUCTION: The novel ultrasonic osteotomy technique (Piezosurgery) is an alternative to conventional osteotomy devices. The aim of the present study was to carry out morphological comparison of the bone surface using conventional osteotomy techniques in comparison to the rather new ultrasonic osteotomy technique by means of a reflected-light microscopic examination. MATERIALS AND METHODS: Following the sacrifice of 12 rabbits, 24 standardized bone samples were removed from the skull. The osteotomy devices used were a rotating instrument (Lindemann bur), an oscillating micro-saw, and an ultrasonic osteotomy device (Piezosurgery) with insert tips OT6 and OT7. The times needed for osteotomy were measured. The bone surfaces were examined using a reflected-light microscope with a magnification of 40x and 100x. RESULTS: Osteotomy with Piezosurgery is significantly more time consuming than osteotomy with conventional methods (p<0.05). Following osteotomy with the ultrasonic device, the reflected-light microscopic examinations of the unmodified bone samples revealed typical bone structure of the calvaria, including compacta externa, diploe and compacta interna. On the contrary, following osteotomy with the conventional devices, the diploe structure presented distinct modifications. The cancellous spaces were filled with bone debris, and the cancellous structure was demolished. The samples prepared by the micro-saw technique showed a superficially condensed and grooved surface. CONCLUSION: In the present study, well-defined differences were observed following osteotomy with conventional devices and osteotomy with the ultrasonic device. The integrity of the bony structure observed after the ultrasonic technique could benefit the bone healing process. Further studies dealing with the bone healing process after using different osteotomy techniques are recommended. 相似文献
104.
Estimation of anisotropy coefficient of swine pancreas,liver and muscle at 1064 nm based on goniometric technique 下载免费PDF全文
Paola Saccomandi Vitali Vogel Babak Bazrafshan Jürgen Maurer Emiliano Schena Thomas J. Vogl Sergio Silvestri Werner Mäntele 《Journal of biophotonics》2015,8(5):422-428
Optical properties of tissues are required for theoretical modeling of Laser Ablation in tumor therapy. The light scattering characteristic of tissues is described by the anisotropy coefficient, g. The relationship between the angular distribution of scattered light and g is given by the Henyey‐Greenstein (HG) phase function. This work describes the estimation of anisotropy coefficients of ex vivo swine pancreas, liver and muscle at 1064 nm. The intensities of scattered light at fixed angles were measured under repeatability conditions. Experimental data were fitted with a two‐term HG, estimating the anisotropy coefficients for the forward (e.g., 0.956 for pancreas, 0.964 for liver and 0.968 for muscle) and the backward (e.g., –0.481 for pancreas, –0.414 for liver and –0.372 for muscle) scattering.
105.
Erik T. Sakowski Stefan Koster Cynthia Portal Celhay Heidi S. Park Elina Shrestha Stefanie E. Hetzenecker Katie Maurer Ken Cadwell Jennifer A. Philips 《PLoS pathogens》2015,11(7)
The success of Mycobacterium tuberculosis (Mtb) as a pathogen rests upon its ability to grow intracellularly in macrophages. Interferon-gamma (IFN-γ) is critical in host defense against Mtb and stimulates macrophage clearance of Mtb through an autophagy pathway. Here we show that the host protein ubiquilin 1 (UBQLN1) promotes IFN-γ-mediated autophagic clearance of Mtb. Ubiquilin family members have previously been shown to recognize proteins that aggregate in neurodegenerative disorders. We find that UBQLN1 can interact with Mtb surface proteins and associates with the bacilli in vitro. In IFN-γ activated macrophages, UBQLN1 co-localizes with Mtb and promotes the anti-mycobacterial activity of IFN-γ. The association of UBQLN1 with Mtb depends upon the secreted bacterial protein, EsxA, which is involved in permeabilizing host phagosomes. In autophagy-deficient macrophages, UBQLN1 accumulates around Mtb, consistent with the idea that it marks bacilli that traffic through the autophagy pathway. Moreover, UBQLN1 promotes ubiquitin, p62, and LC3 accumulation around Mtb, acting independently of the E3 ligase parkin. In summary, we propose a model in which UBQLN1 recognizes Mtb and in turn recruits the autophagy machinery thereby promoting intracellular control of Mtb. Thus, polymorphisms in ubiquilins, which are known to influence susceptibility to neurodegenerative illnesses, might also play a role in host defense against Mtb. 相似文献
106.
Katharina M. Katsaros Walter S Speidl Svitlana Demyanets Stefan P. Kastl Konstantin A. Krychtiuk Anna Wonnerth Gerlinde Zorn Ioannis Tentzeris Serdar Farhan Gerald Maurer Johann Wojta Kurt Huber 《PloS one》2015,10(11)
Granulocyte-colony-stimulating-factor (G-CSF) induces mobilization of progenitor cells but may also exert pro-inflammatory and pro-thrombotic effects. Treatment with recombinant G-CSF after acute myocardial infarction is currently under examination and has been associated with in-stent restenosis. However, it is not known whether plasma levels of endogenous G-CSF are also associated with an increased cardiovascular risk. Therefore we included 280 patients with angiographically proven stable coronary artery disease. G-CSF was measured by specific ELISA and patients were followed for a median of 30 months for the occurrence of major adverse cardiovascular events (MACE: death, myocardial infarction, re-hospitalization). Those with cardiac events during follow-up showed significant higher G-CSF levels (32.3 pg/mL IQR 21.4–40.5 pg/mL vs. 24.6 pg/mL IQR 16.4–34.9 pg/mL; p<0.05) at baseline. Patients with G-CSF plasma levels above the median had a 2-fold increased risk for MACE (p<0.05). This was independent from established cardiovascular risk factors. In addition, G-CSF above the median was a predictor of clinical in-stent restenosis after implantation of bare-metal stents (6.6% vs. 19.4%; p<0.05) but not of drug-eluting stents (7.7% vs. 7.6%; p = 0.98). This data suggests that endogenous plasma levels of G-CSF predict cardiovascular events independently from established cardiac risk factors and are associated with increased in-stent restenosis rates after implantation of bare metal stents. 相似文献
107.
Stefan Hoerzer Peter A. Federolf Christian Maurer Jennifer Baltich Benno M. Nigg 《PloS one》2015,10(10)
Previous research on elderly people has suggested that footwear may improve neuromuscular control of motion. If footwear does in fact improve neuromuscular control, then such an influence might already be present in young, healthy adults. A feature that is often used to assess neuromuscular control of motion is the level of gait asymmetry. The objectives of the study were (a) to develop a comprehensive asymmetry index (CAI) that is capable of detecting gait asymmetry changes caused by external boundary conditions such as footwear, and (b) to use the CAI to investigate whether footwear influences gait asymmetry during running in a healthy, young cohort. Kinematic and kinetic data were collected for both legs of 15 subjects performing five barefoot and five shod over-ground running trials. Thirty continuous gait variables including ground reaction forces and variables of the hip, knee, and ankle joints were computed for each leg. For each individual, the differences between the variables for the right and left leg were calculated. Using this data, a principal component analysis was conducted to obtain the CAI. This study had two main outcomes. First, a sensitivity analysis suggested that the CAI had an improved sensitivity for detecting changes in gait asymmetry caused by external boundary conditions. The CAI may, therefore, have important clinical applications such as monitoring the progress of neuromuscular diseases (e.g. stroke or cerebral palsy). Second, the mean CAI for shod running (131.2 ± 48.5; mean ± standard deviation) was significantly lower (p = 0.041) than the CAI for barefoot running (155.7 ± 39.5). This finding suggests that in healthy, young adults gait asymmetry is reduced when running in shoes compared to running barefoot, which may be a result of improved neuromuscular control caused by changes in the afferent sensory feedback. 相似文献
108.
109.
Kevin K.-C. Liu Peter Cornelius Terrell A. Patterson Yuan Zeng Stephanie Santucci Elizabeth Tomlinson Colleen Gibbons Tristan S. Maurer Ravi Marala Janice Brown Jimmy X. Kong Eunsun Lee Wendy Werner Zane Wenzel Chandra Vage 《Bioorganic & medicinal chemistry letters》2010,20(1):266-271
Based on our original pyrazine hit, CP-0809101, novel conformationally-restricted 5HT2c receptor agonists with 2-piperazin-azaindane scaffold were designed. Synthesis and structure–activity relationship (SAR) studies are described with emphasis on optimization of the selectivity against 5HT2a and 5HT2b receptors with excellent 2c potency. Orally-active and selective compounds were identified with dose–responsive in vivo efficacy in our pre-clinical food intake model. 相似文献
110.
Stefan Sturm Felix Hammann Juergen Drewe Hans H. Maurer André Scholer 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2010,878(28):2726-2732
A fully automated screening using liquid chromatography–mass spectrometric method applying data-dependent acquisition was developed to identify toxicologically relevant substances in serum and urine. A library including more than 405 spectra of about 365 compounds (main drugs and important metabolites) was established. An easy to use program was created to automate and accelerate library search. Drugs were identified based on their relative retention times, molecular ions and fragment ions. Limits of detection were tested with 100 of the 365 compounds the majority of these were lower than 100 μg/l (67%). The developed LC–MS–MS system seems to be a valuable alternative to other general unknown screening methods allowing fast and specific identification of drugs in serum and urine samples. 相似文献