146 research outputs found
Narrow band imaging (NBI) during medical thoracoscopy: first impressions
<p>Abstract</p> <p>Background</p> <p>This is the first ever evaluation of narrow band imaging (NBI), an innovative endoscopic imaging procedure, for the visualisation of pleural processes.</p> <p>Methods</p> <p>The pleural cavity was examined in 26 patients with pleural effusions using both white light and narrow band imaging during thoracoscopy under local anaesthesia.</p> <p>Results</p> <p>In the great majority of the patients narrow band imaging depicted the blood vessels more clearly than white light, but failed to reveal any differences in number, shape or size. Only in a single case with pleura thickened by chronic inflammation and metastatic spread of lung cancer did narrow band imaging show vessels that were not detectable under white light.</p> <p>Conclusion</p> <p>It is not yet possible to assess to what extent the evidence provided by NBI is superior to that achieved with white light. Further studies are required, particularly in the early stages of pleural processes.</p
Gemcitabine combined with oxaliplatin in pretreated patients with malignant pleural mesothelioma: an observational study
<p>Abstract</p> <p>Background</p> <p>The aim of this study was to investigate the efficacy and safety of oxaliplatin ± gemcitabine in patients with diffuse malignant pleural mesothelioma (MPM) pretreated with pemetrexed.</p> <p>Methods</p> <p>The study enrolled consecutive patients with relapsed MPM, all of them pretreated with a platin-pemetrexed-based chemotherapy. Oxaliplatin 80 mg/m<sup>2 </sup>was administered as monotherapy or in combination with gemcitabine 1000 mg/m<sup>2 </sup>given on day 1 and 8. Cycles were repeated every 21 days. The primary endpoints were response rate and disease control rate. Secondary endpoints included overall survival (OS), time to tumour progression (TTP), progression-free survival (PFS), time to treatment failure (TTF), and toxicity.</p> <p>Results</p> <p>Between February 2005 and September 2007 29 patients (median age: 65.0 years, World Health Organisation (WHO) performance status: 0–3) were enrolled. The follow-up period encompassed 5.4 to 97.4 weeks (median: 24.3 weeks). Out of these 29 patients, 15 were treated in second, 10 in third, 3 in fourth and 1 in fifth line, respectively. The majority of the patients received the combination oxaliplatin and gemcitabine (n = 25 vs. 4; 86.2 vs. 13.8%).</p> <p>The median overall survival (OS) was 71.7 weeks (30.6–243.3 weeks), whereas survival from the start of oxaliplatin/gemcitabine-treatment was 24.3 weeks (5.4–97.3 weeks). Median time to tumour progression (TTP) was 9.3 weeks (3.0–67.6 weeks).</p> <p>Partial response (PR) was observed in 2 patients (6.9%), stable disease (SD) for at least three courses of treatment in 11 patients (37.9%). Thus, disease control rate was 44.8%, whereas 16 of 29 patients exhibited progressive disease (55.2%).</p> <p>The toxicity profile was favourable, with no WHO grade 4-toxicities, only few dose-reductions were performed due to non-symptomatic haematotoxicities (neutropenia, thrombopenia). Mild WHO grade 2 neurotoxicity was seen in 6 patients.</p> <p>Conclusion</p> <p>Pemetrexed-pretreated patients with progressive MPM may benefit from a consecutive chemotherapy with oxaliplatin and gemcitabine without significant toxicity.</p
BNDB – The Biochemical Network Database
<p>Abstract</p> <p>Background</p> <p>Technological advances in high-throughput techniques and efficient data acquisition methods have resulted in a massive amount of life science data. The data is stored in numerous databases that have been established over the last decades and are essential resources for scientists nowadays. However, the diversity of the databases and the underlying data models make it difficult to combine this information for solving complex problems in systems biology. Currently, researchers typically have to browse several, often highly focused, databases to obtain the required information. Hence, there is a pressing need for more efficient systems for integrating, analyzing, and interpreting these data. The standardization and virtual consolidation of the databases is a major challenge resulting in a unified access to a variety of data sources.</p> <p>Description</p> <p>We present the Biochemical Network Database (BNDB), a powerful relational database platform, allowing a complete semantic integration of an extensive collection of external databases. BNDB is built upon a comprehensive and extensible object model called BioCore, which is powerful enough to model most known biochemical processes and at the same time easily extensible to be adapted to new biological concepts. Besides a web interface for the search and curation of the data, a Java-based viewer (BiNA) provides a powerful platform-independent visualization and navigation of the data. BiNA uses sophisticated graph layout algorithms for an interactive visualization and navigation of BNDB.</p> <p>Conclusion</p> <p>BNDB allows a simple, unified access to a variety of external data sources. Its tight integration with the biochemical network library BN++ offers the possibility for import, integration, analysis, and visualization of the data. BNDB is freely accessible at <url>http://www.bndb.org</url>.</p
Error in hydraulic head and gradient time-series measurements: a quantitative appraisal
&lt;p&gt;&lt;strong&gt;Abstract.&lt;/strong&gt; Hydraulic head and gradient measurements underpin practically all investigations in hydro(geo)logy. There is sufficient information in the literature to suggest that head measurement errors may be so large that flow directions can not be inferred reliably, and that their magnitude can have as great an effect on the uncertainty of flow rates as the hydraulic conductivity. Yet, educational text books contain limited content regarding measurement techniques and studies rarely report on measurement errors. The objective of our study is to review currently-accepted standard operating procedures in hydrological research and to determine the smallest head gradients that can be resolved. To this aim, we first systematically investigate the systematic and random measurements errors involved in collecting time series information on hydraulic head at a given location: (1) geospatial position, (2) point of head, (3) depth to water, and (4) water level time series. Then, by propagating the random errors, we find that with current standard practice, horizontal head gradients&amp;#8201;&lt;&amp;#8201;10&lt;sup&gt;&amp;#8722;4&lt;/sup&gt; are resolvable at distances&amp;#8201;&amp;#10886;&amp;#8201;170&amp;#8201;m. Further, it takes extraordinary effort to measure hydraulic head gradients&amp;#8201;&lt;&amp;#8201;10&lt;sup&gt;&amp;#8722;3&lt;/sup&gt; over distances&amp;#8201;&lt;&amp;#8201;10&amp;#8201;m. In reality, accuracy will be worse than our theoretical estimates because of the many possible systematic errors. Regional flow on a scale of kilometres or more can be inferred with current best-practice methods, but processes such as vertical flow within an aquifer cannot be determined until more accurate and precise measurement methods are developed. Finally, we offer a concise set of recommendations for water level, hydraulic head and gradient time series measurements. We anticipate that our work contributes to progressing the quality of head time series data in the hydro(geo)logical sciences, and provides a starting point for the development of universal measurement protocols for water level data collection.&lt;/p&gt; </jats:p
Exposing metal and silicate charges to electrical discharges: Did chondrules form by nebular lightning?
In order to investigate the hypothesis that dust aggregates were transformed
to meteoritic chondrules by nebular lightning, we exposed silicatic and
metallic dust samples to electric discharges with energies of 120 to 500 J in
air at pressures between 10 and 10^5 Pa. The target charges consisted of
powders of micrometer-sized particles and had dimensions of mm. The dust
samples generally fragmented leaving the major fraction thermally unprocessed.
A minor part formed sintered aggregates of 50 to 500 micrometer. In a few
experiments melt spherules having sizes smaller than 180 micrometer in diameter
(and, generally, interior voids) were formed; the highest spherule fraction was
obtained with metallic Ni. Our experiments indicate that chondrule formation by
electric current or by particle bombardment inside a discharge channel is
unlikely.Comment: Accepted by Icaru
Risk Assessment for Patients with Chronic Respiratory Conditions in the Context of the SARS-CoV-2 Pandemic Statement of the German Respiratory Society with the Support of the German Association of Chest Physicians
Assessing the risk for specific patient groups to suffer from
severe courses of COVID-19 is of major importance in the
current SARS-CoV-2 pandemic. This review focusses on the
risk for specific patient groups with chronic respiratory conditions, such as patients with asthma, chronic obstructive
pulmonary disease, cystic fibrosis (CF), sarcoidosis, interstitial lung diseases, lung cancer, sleep apnea, tuberculosis,
neuromuscular diseases, a history of pulmonary embolism,
and patients with lung transplants. Evidence and recommendations are detailed in exemplary cases. While some patient
groups with chronic respiratory conditions have an increased risk for severe courses of COVID-19, an increasing
number of studies confirm that asthma is not a risk factor
for severe COVID-19. However, other risk factors such as
higher age, obesity, male gender, diabetes, cardiovascular
diseases, chronic kidney or liver disease, cerebrovascular
and neurological disease, and various immunodeficiencies
or treatments with immunosuppressants need to be taken
into account when assessing the risk for severe COVID-19 in
patients with chronic respiratory diseases
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