julilili42/papers huggingface dataset:
Reduced metabolic rate and oxygen radicals production in stored insect sperm
2012-01-25

Females of internally fertilizing species can significantly extend sperm lifespan and functionality during sperm storage. The mechanisms for such delayed cellular senescence remain unknown. Here, we apply current hypotheses of cellular senescence developed for diploid cells to sperm cells, and empirically test opposing predictions on the relationship between sperm metabolic rate and oxygen radical production in an insect model, the cricket Gryllus bimaculatus . Using time-resolved microfluorimetry, we found a negative correlation between metabolic rate (proportion of protein-bound NAD[P]H) and in situ intracellular oxygen radicals production in freshly ejaculated sperm. In contrast, sperm stored by females for periods of 1 h to 26 days showed a positive correlation between metabolic rate and oxygen radicals production. At the same time, stored sperm showed a 37 per cent reduced metabolic rate, and 42 per cent reduced reactive oxygen species (ROS) production, compared with freshly ejaculated sperm. Rank differences between males in ROS production and metabolic rate observed in ejaculated sperm did not predict rank differences in stored sperm. Our method of simultaneously measuring ROS production and metabolic rate of the same sample has the advantage of providing data that are independent of sperm density and any extracellular antioxidants that are proteins. Our method also excludes effects owing to accumulated hydrogen peroxide. Our results unify aspects of competing theories of cellular ageing and suggest that reducing metabolic rate may be an important means of extending stored sperm lifespan and functionality in crickets. Our data also provide a possible explanation for why traits of ejaculates sampled from the male may be rather poor predictors of paternity in sexual selection studies and likelihood of pregnancy in reproductive medicine.
Leading-order infrared quantum chromodynamics in Coulomb gauge
2012-01-25

A truncation scheme for the Dyson-Schwinger equations of quantum\\nchromodynamics in Coulomb gauge within the first order formalism is presented.\\nThe truncation is based on an Ansatz for the Coulomb kernel occurring in the\\naction. Results at leading loop order and in the infrared are discussed for\\nboth the Yang-Mills and quark sectors. It is found that the resulting equations\\nfor the static gluon and quark propagators agree with those derived in a\\nquasi-particle approximation to the canonical Hamiltonian approach. Moreover, a\\nconnection to the heavy quark limit is established. The equations are analyzed\\nnumerically and it is seen that in both the gluonic and quark sectors, a\\nnontrivial dynamical infrared mass scale emerges.\\n
Toll‐like receptors 2 and 4 impair insulin‐mediated brain activity by interleukin‐6 and osteopontin and alter sleep architecture
2012-01-25

Impaired insulin action in the brain represents an early step in the progression toward type 2 diabetes, and elevated levels of saturated free fatty acids are known to impair insulin action in prediabetic subjects. One potential mediator that links fatty acids to inflammation and insulin resistance is the Toll‐like receptor (TLR) family. Therefore, C3H/HeJ/TLR2‐KO (TLR2/4‐deficient) mice were fed a high‐fat diet (HFD), and insulin action in the brain as well as cortical and locomotor activity was analyzed by using telemetric implants. TLR2/4‐deficient mice were protected from HFD‐induced glucose intolerance and insulin resistance in the brain and displayed an improvement in cortical and locomotor activity that was not observed in C3H/HeJ mice. Sleep recordings revealed a 42% increase in rapid eye movement sleep in the deficient mice during daytime, and these mice spent 41% more time awake during the night period. Treatment of control mice with a neutralizing IL‐6 antibody improved insulin action in the brain as well as cortical activity and diminished osteopontin protein to levels of the TLR2/4‐deficient mice. Together, our data suggest that the lack of functional TLR2/4 protects mice from a fat‐mediated impairment in insulin action, brain activity, locomotion, and sleep architecture by an IL‐6/osteopontin‐dependent mechanism.—Sartorius, T., Lutz, S. Z., Hoene, M., Waak, J., Peter, A., Weigert, C., Rammensee, H.‐G., Kahle, P. J., Häring, H.‐U., Hennige, A. M. Toll‐like receptors 2 and 4 impair insulin‐mediated brain activity by interleukin‐6 and osteopontin and alter sleep architecture. FASEB J. 26, 1799‐1809 (2012). www.fasebj.org
Limits to reconstructing paleotopography from thermochronometer data
2012-01-25

Recent studies suggest that orogens can achieve a topographic steady state whereby equilibrium is reached between tectonics and erosion. However, steady state topography may not be the norm in many orogens experiencing large changes in climate or tectonics, which can produce topographic transients. The quantification of transient topography over geologic timescales requires reconstructing paleotopography, but this has proven difficult in many cases. This study investigates the utility of bedrock thermochronometer data to reconstruct orogen paleotopography over million year timescales. Apatite (U‐Th)/He and fission track ages are integrated with a thermokinematic model for a single‐parameter inversion of paleotopography. An iterative scheme is used that minimizes the misfit between predicted and observed cooling ages to identify the range of paleotopographies that could produce observed ages within sample uncertainty. Two approaches are considered. First, synthetic 2‐D topographies are used to test the robustness of the approach. The following topographic evolution scenarios are considered: (1) lateral ridge migration, (2) topographic relief change, and (3) valley widening and deepening from glaciation. Second, the method is applied in three dimensions to existing data from the Coast Mountains of British Columbia, Canada. Results from both applications of the model suggest that (1) paleotopographic reconstruction will typically underpredict the magnitude of topographic change, especially relief change; (2) paleotopography is most successfully reconstructed after lateral ridge migration in long‐wavelength topographies; and (3) reconstructed paleotopography from the Coast Mountains, British Columbia, suggests that glacial erosion may have the potential to remove drainage divides and laterally shift topographic ridges and peaks.
A FlAsH Reporter for Protein‐Dimerization Triggers
2012-01-25

A FlAsH of potential: the specific binding of the biarsenical probe to the tetracysteine motif has matured as a tool for cell biology studies. Combining two such binders in one probe generates a useful reporter of protein dimerization events. The current state of art and the perspective for future developments are highlighted.
A Novel Lily-of-the-Valley Fragrance Contrast Agent for Magnetic Resonance and Fluorescence Imaging of Prostate Cancer Cells
2012-01-25

Detection of prostate carcinoma metastases is currently performed either via indirect tests like the prostate specific antigen (PSA) or prostate cancer gene 3 (PCA3) or by biopsies from masses found with medical imaging methods. Our goal was to use an ectopic odorant receptor to target prostate-derived cells throughout the body for imaging by magnetic resonance and fluorescence imaging. We synthesized a conjugate containing undecylic aldehyde (an antagonist of the human olfactory receptor hOR17-4), gadolinium-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (a common magnetic resonance contrast agent) and fluorescein isothiocyanate (a fluorescent dye). Two different prostate cancer cell lines as well as five other different malignant cell lines and healthy prostate epithelial cells were incubated with this conjugate and evaluated by flow cytometry, confocal laser scanning microscopy and magnetic resonance imaging. The prostate- derived healthy and malignant cells showed stronger fluorescence than the non-prostate cancer cell lines in the flow cytometry and confocal laser scanning microscopy experiments. In the magnetic resonance imaging experiments the T1 relaxation time reduction (higher signal intensity) was also stronger for the prostate-derived cells than for the non-prostate cells. The examined conjugate showed high prostate-cell-specificity. This property makes it of potential value in the diagnosis of prostate cancer lymph node metastases.
Use of CPT and other direct push methods for (hydro-) stratigraphic aquifer characterization — a field study
2012-01-26

Every environmental site investigation aims at delineating near-surface (hydro-) stratigraphic units and their characterization. To determine the type and hydraulic properties of sedimentary deposits, direct push (DP) sensor probes and tools are promising methods and are therefore frequently applied to measure high-resolution vertical profiles of soil properties. Given the variety of these tools, the objective of this paper is to compare selected DP tools for the (hydro-) stratigraphic subsurface characterization in a heterogeneous unconsolidated sedimentary aquifer. An overview of current DP applications is given and selected DP tools were tested for reproducibility, as well as their ability to reflect soil variability and to estimate hydraulic conductivity, K. Although resolution differences exist, all of the applied methods captured the main aquifer structure. Correlations of the DP-based K estimates or proxies with DP slug tests (DPST) show that it is possible to describe the aquifer hydraulic structure on less than a metre scale by combining DPST data and continuous DP measurements. Although correlations are site-specific and appropriate DP tools must be chosen, DP is a reliable and efficient alternative for characterizing even strongly heterogeneous sites with complex sedimentary architectures.
Local refractive index probed via the fluorescence decay of semiconductor quantum dots
2012-01-26

We present a novel approach for convenient tuning of the local refractive index around nanostructures. We apply this technique to study the influence of the local refractive index on the radiative decay time of CdSe/ZnS quantum dots with three distinct emission wavelengths. The dependence of the luminescence decay time on the environment is well described by an effective medium approach. A critical distance of about 80 nm is found for the determination of the effective local index of refraction. An estimation for the emitting-state quantum efficiency can be extracted.
Organic–Organic Heterostructures: Concepts and Applications
2012-01-27

Abstract We review basic concepts as well as recent examples and applications of organic–organic heterostructures. We organize the different types of heterostructures according to material A deposited on material B (A/B), A co‐deposited with B (A:B), heterostructures in the monolayer regime including nanostructuring concepts and systems involving self‐assembled monolayers, as well as various other architectures, including superlattices. While most examples are related to small‐molecule organic semiconductors, many of the ideas can be applied to other systems. The central theme is growth and structure as well as optical and electronic properties. Finally, we comment on implications for device applications.
Advances in the Detection of As in Environmental Samples Using Low Energy X-ray Fluorescence in a Scanning Transmission X-ray Microscope: Arsenic Immobilization by an Fe(II)-Oxidizing Freshwater Bacteria
2012-01-27

Speciation and quantitative mapping of elements, organic and inorganic compounds, and mineral phases in environmental samples at high spatial resolution is needed in many areas of geobiochemistry and environmental science. Scanning transmission X-ray microscopes (STXMs) provide a focused beam which can interrogate samples at a fine spatial scale. Quantitative chemical information can be extracted using the transmitted and energy-resolved X-ray fluorescence channels simultaneously. Here we compare the relative merits of transmission and low-energy X-ray fluorescence detection of X-ray absorption for speciation and quantitative analysis of the spatial distribution of arsenic(V) within cell-mineral aggregates formed by Acidovorax sp. strain BoFeN1, an anaerobic nitrate-reducing Fe(II)-oxidizing β-proteobacteria isolated from the sediments of Lake Constance. This species is noted to be highly tolerant to high levels of As(V). Related, As-tolerant Acidovorax-strains have been found in As-contaminated groundwater wells in Bangladesh and Cambodia wherein they might influence the mobility of As by providing sorption sites which might have different properties as compared to chemically formed Fe-minerals. In addition to demonstrating the lower detection limits that are achieved with X-ray fluorescence relative to transmission detection in STXM, this study helps to gain insights into the mechanisms of As immobilization by biogenic Fe-mineral formation and to further the understanding of As-resistance of anaerobic Fe(II)-oxidizing bacteria.
Skin cancer in organ transplant recipients
2012-01-27

Cancer development is one of the most important late complications in organ transplant recipients. Skin cancer represents 40–50% of post-transplant malignancies and is the most common cancer. Within the first 10 years post-transplantation, 15–40% of graft recipients develop skin cancer, mainly cancers of epithelial origin induced by UV irradiation, infection with certain human papillomaviruses or other viruses that either promote or even directly induce various skin cancers. These cancers frequently grow rapidly with an increased risk of metastasis, and dermatologists have a prominent position in managing these patients. Management of skin cancer comprises primary prevention, more frequently secondary prophylaxis and appropriate treatment of established cancers. In high-risk skin cancer patients or metastatic disease, reduction of immunosuppression and change of calcineurin inhibitors to mTOR inhibitors may substantially improve the prognosis.
Spectroscopy of a fractional Josephson vortex molecule
2012-01-27

In long Josephson junctions with multiple discontinuities of the Josephson phase, fractional vortex molecules are spontaneously formed. At each discontinuity point a fractional Josephson vortex carrying a magnetic flux , Wb being the magnetic flux quantum, is pinned. Each vortex has an oscillatory eigenmode with a frequency that depends on and lies inside the plasma gap. We experimentally investigate the dependence of the eigenfrequencies of a two-vortex molecule on the distance between the vortices, on their topological charge and on the bias current applied to the Josephson junction. We find that with decreasing distance between vortices, a splitting of the eigenfrequencies occurs, that corresponds to the emergence of collective oscillatory modes of both vortices. We use a resonant microwave spectroscopy technique and find good agreement between experimental results and theoretical predictions.
European Governance: On the Relationship Between Democratic and Non-democratic Deliberation Within the European Multi-level System
2012-01-27

Abstract A few scholars regard the European Union and its specific forms of governance as an experimental ground for the development of democratic structures and processes beyond the nation-state. Over the past years, the debate has been strongly affected by representatives of a theory of deliberative democracy who – often following the conceptual reflections of Jürgen Habermas – emphasize the communicative potential of reason inherent to European networks of deliberation and decision-making. The present article addresses the question of whether or rather to what extent the theory of deliberative democracy conceives and interprets the non-democratic character of the forms of European network governance in an appropriate way. The article argues that this is only partly the case. On the one hand, the developed theoretical perspective is instructive to focus on the procedural political-institutional embeddedness of deliberative policy-making; on the other hand, the theory of deliberative democracy is analytically too weak in order to identify the political economic and political sociological causes of the non-democratic quality of European network governance.
Influence of sandblasting of zirconia veneered with Zirox on bond strength and static fatigue behaviour by Schwickerath-Test
2012-01-27

There are different recommendations for sandblasting of zirconia.The aim of this study was to compare the influence of sandblasted zirconia veneered with Zirox on bond strength and static fatigue.120 stripes of zirconia were prepared, 60 samples were sandblasted with 110 μm Al2O3.For each test 30 samples were used of each group.The bond strength test was done according to ISO 9693.The fatigue behaviour was investigated using a static staircase test.The bond strength results according to ISO 9693 were not significantly different for both groups, however, the static fatigue test of sandblasted zirconia revealed higher bond strength values.
Introducing a Large Animal Model to Create Urethral Stricture Similar to Human Stricture Disease: A Comparative Experimental Microscopic Study
2012-01-28

We successfully developed a large animal model in which to study urethral stricture formation by defined iatrogenic intervention. The established animal model advances investigation to evaluate new therapy modalities in a preclinical setting to treat urethral stricture and predict clinical outcome.
Beyond quantitative decline: Conceptual shifts in adolescents' development of interest in mathematics.
2012-01-30

Research has shown that the average values for academic interest decrease during adolescence. Looking beyond such quantitative decline, we explored qualitative change of interest in the domain of mathematics across adolescence. Study 1 was based on a longitudinal data set (annual assessments from Grade 5 to Grade 9; N = 3,193). Latent variable modeling showed that the measurement coefficients of the latent variable of interest (intercepts, structural weights, and error variances) significantly differed across time points, indicating structural changes of the construct. Study 2 was based on interviews with adolescents (Grades 5 and 9, N = 70). Cognitive validation was used to explore differences in subjective concepts of interest across age groups. As expected, there were significant age-related differences, indicating a shift from an affect-laden concept in 5th grade to a more cognitively oriented concept in 9th grade. The findings suggest that developmental research should integrate quantitative and qualitative perspectives of construct change over time and pay more attention to issues of measurement invariance and qualitative changes of constructs over time.
GATA5 CpG island methylation in renal cell cancer: a potential biomarker for metastasis and disease progression
2012-01-30

What's known on the subject? and What does the study add? GATA5 CpG island (CGI) methylation and transcriptional inactivation is involved in colorectal and gastric cancer. Whether DNA methylation of GATA5 affects clinical pathology is still unclear. In the present study, we analysed, for the first time, CGI methylation in RCC and its association with clinicopathological parameters and progression‐free survival of patients. We show for the first time GATA5 CGI hypermethylation in RCC. Moreover, we found out that increased methylation is statistically associated with status of metastasis, progressive disease and shortened progression‐free survival. The present study underline the necessity for further functional investigations as well as prospective survival analyses to clarify whether GATA5 promoter methylation can provide independent information for future clinical management of patients with RCC. OBJECTIVE To investigate whether GATA5 CpG island (CGI) methylation occurs in renal cell carcinoma (RCC) and is associated with clinical, histopathological characteristics or progression‐free survival of patients. PATIENTS AND METHODS Methylation was quantified in 117 RCC samples and 89 paired adjacent normal tissues using quantitative combined bisulphite restriction analysis (COBRA). COBRA was evaluated in advance by pyrosequencing analyses of control RCC cell lines (coefficient of correlation, R = 0.95). Statistical analyses were carried out using the paired t ‐test for matched tumour tissue (TU) and adjacent normal tissue (adN) samples, logistic regression for comparisons of independent sample groups and Cox regression for analysis of progression‐free survival. RESULTS In the present study, we found a significant higher mean relative methylation in TU (20.4%) than in adN (7.9%, P &lt; 0.001) in paired samples of all RCCs. Increased GATA5 methylation in tumours was associated with metastasis ( P = 0.005) and decreased progression‐free survival ( P = 0.005, HR = 4.59) in the clear‐cell RCC (ccRCC) group. CGI methylation in advanced ccRCCs (pT ≥3 and/or N1, M1 or G2–3/G3) exceeds those detected in localized tumours (pT ≤2, N0, M0, G1/G1–2) (27.8% vs 11.0%, P &lt; 0.001). CONCLUSIONS The association of GATA5 hypermethylation with metastasis and progression‐free survival of patients indicates that epigenetic alterations of GATA5 participate in renal cell carcinogenesis. Moreover, GATA5 CGI methylation could serve as a biomarker for tumour progression, although prospective and functional investigations are necessary to clarify whether independent information for future clinical management of patients with RCC can be obtained.
A Pilot Study on Cytotoxic T Lymphocyte-4 Gene Polymorphisms in Urinary Schistosomiasis
2012-01-30

Urinary schistosomiasis is caused by the digenetic trematode Schistosoma haematobium, characterized by accumulation of eggs in the genitourinary tract. Cytotoxic T-lymphocyte antigen 4 (CTLA-4) can play an important role in parasitic infection due to its major role as a negative regulator of T-cell activation and proliferation. This study was performed in patients with schistosomiasis and healthy controls to analyze the allele and genotype frequencies of four CTLA-4 gene polymorphisms. The CTLA-4 gene was amplified using Taqman real-time polymerase chain reaction, and allele and genotypes of 49 patients with schistosomiasis were analyzed using allelic discrimination analysis followed by subsequent direct sequencing. The results were compared with healthy control subjects. The frequencies of CTLA-4 rs733618 A allele at position -1722 (p=0.001), rs11571316 C allele at position -1577 (p<0.001), and rs231775 A allele at position +49 (p=0.002) in the patient group were significantly higher than the control group. The rs733618 AA genotype (p=0.001), rs11571316 CC genotype (p<0.001), and rs231775 AA genotype (p=0.007) were also significantly overrepresented. Meanwhile, rs733618 AG genotype (p=0.001), rs11571316 CT genotype (p=0.02), and rs231775 GG genotype (p=0.029) were significantly decreased in the patients with schistosomiasis, as compared with the controls. No significant difference was observed in both allele and genotype of rs16841252. The results of this study suggest that the rs733618, rs11571316, and rs231775 polymorphisms in the CTLA-4 gene may influence susceptibility to schistosomiasis infection in the Gabonese children.
Low-cost electrochemical multisensor card for medical applications comprising a novel stable solid-state reference electrode
2012-01-30

Article Low-cost electrochemical multisensor card for medical applications comprising a novel stable solid-state reference electrode was published on August 30, 2012 in the journal Biomedical Engineering / Biomedizinische Technik (volume 57, issue SI-1-Track-E).