946 resultados para Minimal quantity of lubricant (MQL)


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When evaluated for promotion or tenure, faculty members are increasingly judged more on the quality than on the quantity of their scholarly publications. As a result, they want help from librarians in locating all citations to their published works for documentation in their curriculum vitae. Citation analysis using Science Citation Index and Social Science Citation Index provides a logical starting point in measuring quality, but the limitations of these sources leave a void in coverage of citations to an author's work. This article discusses alternative and additional methods of locating citations to published works.

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Although several detailed models of molecular processes essential for circadian oscillations have been developed, their complexity makes intuitive understanding of the oscillation mechanism difficult. The goal of the present study was to reduce a previously developed, detailed model to a minimal representation of the transcriptional regulation essential for circadian rhythmicity in Drosophila. The reduced model contains only two differential equations, each with time delays. A negative feedback loop is included, in which PER protein represses per transcription by binding the dCLOCK transcription factor. A positive feedback loop is also included, in which dCLOCK indirectly enhances its own formation. The model simulated circadian oscillations, light entrainment, and a phase-response curve with qualitative similarities to experiment. Time delays were found to be essential for simulation of circadian oscillations with this model. To examine the robustness of the simplified model to fluctuations in molecule numbers, a stochastic variant was constructed. Robust circadian oscillations and entrainment to light pulses were simulated with fewer than 80 molecules of each gene product present on average. Circadian oscillations persisted when the positive feedback loop was removed. Moreover, elimination of positive feedback did not decrease the robustness of oscillations to stochastic fluctuations or to variations in parameter values. Such reduced models can aid understanding of the oscillation mechanisms in Drosophila and in other organisms in which feedback regulation of transcription may play an important role.

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Object Resection of lesions close to the primary motor cortex (M1) and the corticospinal tract (CST) is generally regarded as high-risk surgery due to reported rates of postoperative severe deficits of up to 50%. The authors' objective was to determine the feasibility and safety of low-threshold motor mapping and its efficacy for increasing the extent of lesion resection in the proximity of M1 and the CST in children and adolescents. Methods The authors analyzed 8 consecutive pediatric patients in whom they performed 9 resections for lesions within or close (≤ 10 mm) to M1 and/or the CST. Monopolar high-frequency motor mapping with train-of-five stimuli (pulse duration 500 μsec, interstimulus interval 4.0 msec, frequency 250 Hz) was used. The motor threshold was defined as the minimal stimulation intensity that elicited motor evoked potentials (MEPs) from target muscles (amplitude > 30 μV). Resection was performed toward M1 and the CST at sites negative to 1- to 3-mA high-frequency train-of-five stimulation. Results The M1 was identified through high-frequency train-of-five via application of varying low intensities. The lowest motor thresholds after final resection ranged from 1 to 9 mA in 8 cases and up to 18 mA in 1 case, indicating proximity to motor neurons. Intraoperative electroencephalography documented an absence of seizures during all surgeries. Two transient neurological deficits were observed, but there were no permanent deficits. Postoperative imaging revealed complete resection in 8 patients and a very small remnant (< 0.175 cm(3)) in 1 patient. Conclusions High-frequency train-of-five with a minimal threshold of 1-3 mA is a feasible and safe procedure for resections in the proximity of the CST. Thus, low-threshold motor mapping might help to expand the area for safe resection in pediatric patients with lesions located within the precentral gyrus and close to the CST, and may be regarded as a functional navigational tool. The additional use of continuous MEP monitoring serves as a safety feedback for the functional integrity of the CST, especially because the true excitability threshold in children is unknown.

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BACKGROUND The quality and quantity of social relationships are associated with depression but there is less evidence regarding which aspects of social relationship are most predictive. We evaluated the relative magnitude and independence of the association of four social relationship domains with major depressive disorder and depressive symptoms. METHODS We analyzed a cross-sectional telephone interview and postal survey of a probability sample of adults living in Switzerland (N = 12,286). Twelve-month major depressive disorder was assessed via structured interview over the telephone using the Composite International Diagnostic Interview (CIDI). The postal survey assessed depressive symptoms as well as variables representing emotional support, tangible support, social integration, and loneliness. RESULTS Each individual social relationship domain was associated with both outcome measures, but in multivariate models being lonely and perceiving unmet emotional support had the largest and most consistent associations across depression outcomes (incidence rate ratios ranging from 1.55-9.97 for loneliness and from 1.23-1.40 for unmet support, p's < 0.05). All social relationship domains except marital status were independently associated with depressive symptoms whereas only loneliness and unmet support were associated with depressive disorder. CONCLUSIONS Perceived quality and frequency of social relationships are associated with clinical depression and depressive symptoms across a wide adult age spectrum. This study extends prior work linking loneliness to depression by showing that a broad range of social relationship domains are associated with psychological well-being.

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Cadmium is a highly volatile element and its abundance in meteorites may help better understand volatility-controlled processes in the solar nebula and on meteorite parent bodies. The large thermal neutron capture cross section of 113Cd suggests that Cd isotopes might be well suited to quantify neutron fluences in extraterrestrial materials. The aims of this study were (1) to evaluate the range and magnitude of Cd concentrations in magmatic iron meteorites, and (2) to assess the potential of Cd isotopes as a neutron dosimeter for iron meteorites. Our new Cd concentration data determined by isotope dilution demonstrate that Cd concentrations in iron meteorites are significantly lower than in some previous studies. In contrast to large systematic variations in the concentration of moderately volatile elements like Ga and Ge, there is neither systematic variation in Cd concentration amongst troilites, nor amongst metal phases of different iron meteorite groups. Instead, Cd is strongly depleted in all iron meteorite groups, implying that the parent bodies accreted well above the condensation temperature of Cd (i.e., ≈650 K) and thus incorporated only minimal amounts of highly volatile elements. No Cd isotope anomalies were found, whereas Pt and W isotope anomalies for the same iron meteorite samples indicate a significant fluence of epithermal and higher energetic neutrons. This observation demonstrates that owing to the high Fe concentrations in iron meteorites, neutron capture mainly occurs at epithermal and higher energies. The combined Cd-Pt-W isotope results from this study thus demonstrate that the relative magnitude of neutron capture-induced isotope anomalies is strongly affected by the chemical composition of the irradiated material. The resulting low fluence of thermal neutrons in iron meteorites and their very low Cd concentrations make Cd isotopes unsuitable as a neutron dosimeter for iron meteorites.

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Abstract The objectives of this study were: 1) To determine factors which inhibit and facilitate child and adolescent use of outdoor spaces for healthy physical activity by race and ethnicity in four Houston communities and 2) To propose guidelines for encouraging and maintaining child and adolescent outdoor physical activity. Using local health data and Houston Police Department crime statistics, four communities were identified for the study that had the highest concentration of crime and the racial/ ethnic groups of interest. The researchers then identified public parks in the communities. At least two parks were observed in each of the four communities from 2010 to 2011 during spring, summer, fall and winter. The parks were observed for use by children and adolescents and to describe the condition of the park spaces. The communities were Alief (Asian), Sunnyside (Black), Eldridge- West Oaks (White) and Northside- Northline (Hispanic). Observations were made at varying hours of both day and night, weekdays and weekends. Photographs were taken and the condition of the spaces noted in detail. One hundred and twenty persons, 18 years and over, using the spaces or otherwise in these communities were conveniently sampled and interviewed about their health and the extent to which they, or any children or adolescents under their care, used the outdoor spaces of interest. Data were analyzed qualitatively and with basic descriptive statistics. The photographs, journal notes and observation notes of all investigators and key personnel were analyzed. Interview data were also coded to identify patterns and themes in the responses. The findings indicate disparities in the quality and quantity of park equipment and the maintenance of the areas. Where perceptions of disorder were described, there was often visible evidence to support the perceptions. In many cases, residents' perceptions of crime were corroborated by police data. While interview reports did not seem to support the expectation that the condition of the parks was a significant deterrent to their use by children and adolescents, the condition of the parks might be said to limit the extent of that use. Specific reports of disorder that inhibited use included hearing gunfire, seeing drug dependent homeless persons and/or suspected prostitutes in an area.

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Heparanase, an endo-$\beta$-D-glucuronidase, has been associated with melanoma metastasis. Polyclonal antibodies directed against the murine N-terminal heparanase peptide detected a M$\sb{\rm r}\sim 97,000$ protein upon SDS-polyacrylamide gel electrophoresis of mouse melanoma and human melanoma cell lysates. In an indirect immunocytochemical study, metastatic human A375-SM and mouse B16-BL6 melanoma cells were stained with the anti-heparanase antibodies. Heparanase antigen was localized in the cytoplasm of permeabilized melanoma cells as well as at the cell surface of unpermeabilized cells. Immunohistochemical staining of frozen sections from syngeneic mouse organs containing micrometastases of B16-BL6 melanoma demonstrated heparanase localized in metastatic melanoma cells, but not in adjacent normal tissues. Similar studies using frozen sections of malignant melanomas resected from patients indicated that heparanase is localized in invading melanoma cells, but not in adjacent connective tissues.^ Monoclonal antibodies directed against murine heparanase were developed and characterized. Monoclonal antibody 10E5, an IgM, precipitated and inhibitated the enzymatic activity of heparanase. A 2.6 kb cDNA was isolated from a human melanoma $\lambda$gt11 cDNA library using the monoclonal antibody 10E5. Heparan sulfate cleavage activity was detected in the lysogen lysates from E. Coli Y1089 infected with the $\lambda$gt11 cDNA and this activity was inhibited in the presence of 10-fold excess of heparin, a potent inhibitor of heparanase. The nucleotide sequence of the cDNA was determined and insignificant homology was found with the gene sequences currently known. The cDNA hybridized to a 3.2-3.4 kb mRNA in human A375 melanoma, WI-38 fibroblast, and THP-1 leukemia cells using Northern blots.^ Heparanase expression was examined using Western and Northern blots. In comparison to human A375-P melanoma cells, the quantity of 97,000 protein recognized by the polyclonal anti-heparanase antibodies doubled in the metastatic variant A375-SM cells and the quantity of 3.2-3.4 kb mRNA doubled in A375MetMix, a metastatic variant similar to A375-SM cells. In B16 murine melanoma cell, the intensity of the 97,000 protein increased more than 2 times comparing with B16-F1 cells. The extent in the increase of the protein and the mRNA levels is comparable to the change of heparanase activity observed in those cells.^ In summary, the studies suggest that (a) the N-terminus of the heparanase molecule in mouse and human is antigenically related; (b) heparanase antigens are localized at the cell surface and in the cytoplasm of metastatic human and mouse melanoma cells; (c) heparanase antigens are localized in invasive and metastatic murine and human melanomas in vivo, but not in adjacent normal tissues; (d) heparanase molecule appeared to be differentially expressed at the transcriptional as well as at the translational level; and (e) the size of human heparanase mRNA is 3.2-3.4 kilobase. ^

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The purpose of this research is to examine the relative profitability of the firm within the nursing facility industry in Texas. An examination is made of the variables expected to affect profitability and of importance to the design and implementation of regulatory policy. To facilitate this inquiry, specific questions addressed are: (1) Do differences in ownership form affect profitability (defined as operating income before fixed costs)? (2) What impact does regional location have on profitability? (3) Do patient case-mix and access to care by Medicaid patients differ between proprietary and non-profit firms and facilities located in urban versus rural regions, and what association exists between these variables and profitability? (4) Are economies of scale present in the nursing home industry? (5) Do nursing facilities operate in a competitive output market characterized by the inability of a single firm to exhibit influence over market price?^ Prior studies have principally employed a cost function to assess efficiency differences between classifications of nursing facilities. The inherent weakness in this approach is that it only considers technical efficiency. Not both technical and price efficiency which are the two components of overall economic efficiency. One firm is more technically efficient compared to another if it is able to produce a given quantity of output at the least possible costs. Price efficiency means that scarce resources are being directed towards their most valued use. Assuming similar prices in both input and output markets, differences in overall economic efficiency between firm classes are assessed through profitability, hence a profit function.^ Using the framework of the profit function, data from 1990 Medicaid Costs Reports for Texas, and the analytic technique of Ordinary Least Squares Regression, the findings of the study indicated (1) similar profitability between nursing facilities organized as for-profit versus non-profit and located in urban versus rural regions, (2) an inverse association between both payor-mix and patient case-mix with profitability, (3) strong evidence for the presence of scale economies, and (4) existence of a competitive market structure. The paper concludes with implications regarding reimbursement methodology and construction moratorium policies in Texas. ^

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The rate and direction of fibroblast locomotion is regulated by the formation of lamellipodia. In turn, lamellipodal formation is modulated in part by adhesion of that region of the cell from which the lamellipodia will extend or orginate. Cell surface $\beta$1,4-galactosyltransferase (GalTase) is one molecule that has been demonstrated to mediate cellular interactions with extracellular matrices. In the case of fibroblasts, GalTase must be associated with the actin cytoskeleton in order to mediate cellular adhesion to laminin. The object of this study was to determine how altering the quantity of GalTase capable of associating with the cytoskeleton impacts cell motility. Stably transfected cell lines were generated that have increased or decreased levels of surface GalTase relative to its cytoskeleton-binding sites. Biochemical analyses of these cells reveals that there is a limited number of sites on the cytoskeleton with which GalTase can interact. Altering the ratio of GalTase to its cytoskeleton binding sites does not affect the cells' abilities to spread, nor does it affect the localization of cytoskeletally-bound GalTase. It does, however, appear to interfere with stress fiber bundling. Cells with altered GalTase:cytoskeleton ratios change their polarity of laminin more frequently, as compared to controls. Therefore, the ectopic expression of GalTase cytoplasmic domains impairs a cell's ability to control the placement of lamellipodia. Cells were then tested for their ability to respond to a directional stimulus, a gradient of platelet-derived growth factor (PDGF). It was found that the ability of a cell to polarize in response to a gradient of PDGF is directly proportional to the quantity of GalTase associated with its cytoskeleton. Finally, the rate of unidirectional cell migration on laminin was found to be directly dependent upon surface GalTase expression and is inversely related to the ability of surface GalTase to interact with the cytoskeleton. It is therefore proposed that cytoskeletal assembly and lamellipodal formation can be regulated by the altering the ratio of cytoplasmic domains for specific matrix receptors, such as GalTase, relative to their cytoskeleton-binding sites. ^

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AIM To compare treatment strategies for respiratory failure in extremely low birth weight (ELBW) infants in Germany in 1997 to Germany, Austria and Switzerland in 2011. METHODS A detailed questionnaire about treatment strategies for ELBW infants was sent to all German centres treating ELBW infants in 1997. A follow-up survey was conducted in 2011 in Germany, Austria and Switzerland. RESULTS In 1997 and 2011, 63.6% and 66.2% of the hospitals responded. In 2011 the response rate was higher in Switzerland than in Germany, and in university hospitals versus non-university hospitals. Treatment strategies did not differ between university and non-university hospitals as well as NICUs of different sizes in 2011. Differences between Germany, Austria and Switzerland were minimal. Administration of caffeine increased significantly, whereas theophylline and doxapram declined (all p<0.001). While the use of dexamethasone decreased and the use of hydrocortisone increased, the overall use of corticosteroids declined (all p<0.001). Between 1997 and 2011 therapy with inhalations and mucolytics decreased (both p<0.001) whereas the use application of diuretics did not change significantly. In mechanically ventilated infants the application of muscle relaxants and sedation declined significantly (p=0.009 and p<0.001), whereas analgesia use did not change. CONCLUSION Treatment strategies for respiratory failure in ELBW infants have changed significantly between 1997 and 2011. This article is protected by copyright. All rights reserved.

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Objective: Since the beginning of the integrated care model for severely ill patients with psychotic disorders ("Hamburg model") in 2007 different clinical parameters have been consecutively assessed within a naturalistic, observational, prospective study.Methods: Clinical outcome of the 2-year and 4-year follow-ups of n = 158 patients.Results: A significant and ongoing improvement of psychopathology, severity of illness, functional outcome, quality of life and satisfaction with care in this sample of severely ill and merely chronic patients with psychosis was shown. Moreover, medication adherence improved and quality and quantity of outpatient treatment increased.Conclusion: The ongoing psychosocial stabilisation of the patients most likely result from a combination of various factors: continuity of care, multimodal and individualized care, therapeutic specialisation and the multidisciplinary ACT team. Results provide clinical and scientific evidence for future implementations of the integrated care model "Hamburg Model" for the treatment of psychosis.

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Stylonychia lemnae is a classical model single-celled eukaryote, and a quintessential ciliate typified by dimorphic nuclei: A small, germline micronucleus and a massive, vegetative macronucleus. The genome within Stylonychia's macronucleus has a very unusual architecture, comprised variably and highly amplified "nanochromosomes," each usually encoding a single gene with a minimal amount of surrounding noncoding DNA. As only a tiny fraction of the Stylonychia genes has been sequenced, and to promote research using this organism, we sequenced its macronuclear genome. We report the analysis of the 50.2-Mb draft S. lemnae macronuclear genome assembly, containing in excess of 16,000 complete nanochromosomes, assembled as less than 20,000 contigs. We found considerable conservation of fundamental genomic properties between S. lemnae and its close relative, Oxytricha trifallax, including nanochromosomal gene synteny, alternative fragmentation, and copy number. Protein domain searches in Stylonychia revealed two new telomere-binding protein homologs and the presence of linker histones. Among the diverse histone variants of S. lemnae and O. trifallax, we found divergent, coexpressed variants corresponding to four of the five core nucleosomal proteins (H1.2, H2A.6, H2B.4, and H3.7) suggesting that these ciliates may possess specialized nucleosomes involved in genome processing during nuclear differentiation. The assembly of the S. lemnae macronuclear genome demonstrates that largely complete, well-assembled highly fragmented genomes of similar size and complexity may be produced from one library and lane of Illumina HiSeq 2000 shotgun sequencing. The provision of the S. lemnae macronuclear genome sets the stage for future detailed experimental studies of chromatin-mediated, RNA-guided developmental genome rearrangements.

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Despite the numerous available possibilities for the surgical treatment of peripheral nerve lesions found in the dog, the success of these treatments is often unsatisfactory. It has been proven that Schwann cells (SC) have a positive influence on the regeneration of nerve stumps. Implanting a guidance channel seeded with autologous SC at the lesion site could be a new therapeutic approach. The aim of this research was to investigate the in vitro cultivation and expansion of canine SC as the main requirement for the treatment referred to above. Biopsies were carried out on 17 nerve samples originating from dogs of different breed, age, gender and condition. The reexplantation method was employed, followed by dissociation using hyaluronidase, collagenase and trypsin and further expansion. The samples were divided into six groups which were treated with a varying combination of mitogens (forskolin, bovine PEX, choleratoxin, heregulin). To obtain the quantities of SC, the specimens were immunostained by a p75-antibody. By employing a growing number of agents it was possible to obtain an increase in both the quantity of cells and purity of cultures. A maximum of 16x10(5) cells per millilitre of suspension was achieved. The largest SC purity measured 27.1%. The maximum SC quantity achieved was 43.3x10(4) SC per millilitre.

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In previous work, Alpine glaciers have been identified as a secondary source of persistent organic pollutants (POPs). However, detailed understanding of the processes organic chemicals undergo in a glacial system was missing. Here, we present results from a chemical fate model describing deposition and incorporation of polychlorinated biphenyls (PCBs) into an Alpine glacier (Fiescherhorn, Switzerland) and an Arctic glacier (Lomonosovfonna, Norway). To understand PCB fate and dynamics, we investigate the interaction of deposition, sorption to ice and particles in the atmosphere and within the glacier, revolatilization, diffusion and degradation, and discuss the effects of these processes on the fate of individual PCB congeners. The model is able to reproduce measured absolute concentrations in the two glaciers for most PCB congeners. While the model generally predicts concentration profiles peaking in the 1970s, in the measurements, this behavior can only be seen for higher-chlorinated PCB congeners on Fiescherhorn glacier. We suspect seasonal melt processes are disturbing the concentration profiles of the lower-chlorinated PCB congeners. While a lower-chlorinated PCB congener is mainly deposited by dry deposition and almost completely revolatilized after deposition, a higher-chlorinated PCB congener is predominantly transferred to the glacier surface by wet deposition and then is incorporated into the glacier ice. The incorporated amounts of PCBs are higher on the Alpine glacier than on the Arctic glacier due to the higher precipitation rate and aerosol particle concentration on the former. Future studies should include the effects of seasonal melt processes, calculate the quantities of PCBs incorporated into the entire glacier surface, and estimate the quantity of chemicals released from glaciers to determine the importance of glaciers as a secondary source of organic chemicals to remote aquatic ecosystems.

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Stepwise uncertainty reduction (SUR) strategies aim at constructing a sequence of points for evaluating a function  f in such a way that the residual uncertainty about a quantity of interest progressively decreases to zero. Using such strategies in the framework of Gaussian process modeling has been shown to be efficient for estimating the volume of excursion of f above a fixed threshold. However, SUR strategies remain cumbersome to use in practice because of their high computational complexity, and the fact that they deliver a single point at each iteration. In this article we introduce several multipoint sampling criteria, allowing the selection of batches of points at which f can be evaluated in parallel. Such criteria are of particular interest when f is costly to evaluate and several CPUs are simultaneously available. We also manage to drastically reduce the computational cost of these strategies through the use of closed form formulas. We illustrate their performances in various numerical experiments, including a nuclear safety test case. Basic notions about kriging, auxiliary problems, complexity calculations, R code, and data are available online as supplementary materials.