389 research outputs found
Von Open Access zu Open Science: zum Wandel digitaler Kulturen der wissenschaftlichen Kommunikation
Mit der Digitalisierung geht der Ruf nach freiem Zugang zu wissenschaftlichen Forschungsergebnissen und einer Ă–ffnung des Forschungsprozesses einher. Open Access und Open Science sind die Leitbegriffe dieses Transformationsprozesses, der von den einen euphorisch begrĂĽĂźt und von den anderen heftig abgelehnt wird. Auf der Grundlage einer quantitativen Erhebung und eines reflexiven Experiments gibt das Buch Einblick in die aktuellen Debatten ĂĽber die Chancen aber auch Hindernisse der Ă–ffnung der Wissenschaften
Integrated Planning of Multi-energy Grids: Concepts and Challenges
In order to meet ever-stricter climate targets and achieve the eventual
decarbonization of the energy supply of German industrial metropolises, the
focus is on gradually phasing out nuclear power, then coal and gas combined
with the increased use of renewable energy sources and employing hydrogen as a
clean energy carrier. While complete electrification of the energy supply of
households and the transportation sector may be the ultimate goal, a
transitional phase is necessary as such massive as well as rapid expansion of
the electrical distribution grid is infeasible. Additionally, German industries
have expressed their plans to use hydrogen as their primary strategy in meeting
carbon targets. This poses challenges to the existing electrical, gas, and
heating distribution grids. It becomes necessary to integrate the planning and
developing procedures for these grids to maximize efficiencies and guarantee
security of supply during the transition. The aim of this paper is thus to
highlight those challenges and present novel concepts for the integrated
planning of the three grids as one multi-energy grid.Comment: NEIS 2022; Conference on Sustainable Energy Supply and Energy Storage
System
Study Protocol of the ESAP Study: Endoscopic Papillectomy vs. Surgical Ampullectomy vs. Pancreaticoduodenectomy for Ampullary Neoplasm—A Pancreas2000/EPC Study
Background: Lesions of the Ampulla of Vater are a rare condition and represent <10%
of peri-ampullary neoplasms. Nevertheless, ampullary adenomas have the potential
for malignant transformation to ampullary carcinomas by an adenoma-to-carcinoma
sequence. Thus, adequate patient selection and complete resection (R0) of non-invasive
ampullary lesions either by endoscopic papillectomy (EP), surgical ampullectomy (SA),
or pancreaticoduodenectomy (PD) is essential. Although PD was traditionally performed,
recent studies reported considerable efficacy and fewer complications following EP and
SA. Since consistent comparative data are lacking, the Endoscopic Papillectomy vs.
Surgical Ampullectomy vs. Pancreaticoduodectomy (ESAP) study will provide evidence
for a therapeutic standard and post procedure morbidity in ampullary lesions.
Methods: International multicenter retrospective study. Adult patients (>18 years of
age) who underwent SA or PD for ampullary neoplasm between 2004 and 2018 or
EP between 2007 and 2018 will be evaluated. Main inclusion criteria are ampullary
lesions strictly located to the ampulla. This includes adenoma, adenocarcinoma (T1 and
T2), neuroendocrine tumors, gastrointestinal stroma tumors and other rare conditions.
Exclusion criteria are peri-ampullary lesions, e.g., from the duodenal wall or the head
of the pancreas, and interventions for tumor stages higher than T2. The main objective
of this study is to analyze rates of complete resection (R0), recurrence and necessity
for complementary interventions following EP, SA, and PD. Treatment-quality for each
procedure will be defined by morbidity, mortality and complication rates and will be
compared between EP, SA, and PD. Secondary objectives include outcome for patients
with incomplete resection or initially understated tumors, lesions of the minor papilla,
hereditary syndromes, neuroendocrine tumors, mesenchymal lesions, and other rare
conditions. Additionally, we will analyze therapy by argon plasma coagulation and
radiofrequency ablation. Furthermore, outcome in curative and palliative interventions
can be distinguished.
Conclusion: The ESAP study will provide evidence for therapeutic algorithms and
data for the implementation of guidelines in the treatment of different types of ampullary
tumors, including recurrent, or incomplete resected lesions
A four-hours long burst from Serpens X-1
During a serendipitous observation of the BeppoSAX Wide Field Cameras, a very
long Type I X-ray burst was observed from the low mass X-ray binary Serpens
X-1. The burst lasted for approximately 4 hours and had an exponential decay
time of 69+/-2 min (2-28 keV). The bolometric peak-luminosity is
(1.6+/-0.2)x10^38 erg/s and the fluence (7.3+/-1.4)x10^41 erg. The first
'normal' Type I burst was observed 34 days after the superburst. This is in
rough agreement with recent predictions for unstable carbon burning in a heavy
element ocean.Comment: 4 pages, 2 figures, accepted for publication by A&
Systematic Review with Meta-Analysis: Endoscopic and Surgical Resection for Ampullary Lesions
Ampullary lesions (ALs) can be treated by endoscopic (EA) or surgical ampullectomy (SA) or pancreaticoduodenectomy (PD). However, EA carries significant risk of incomplete resection while surgical interventions can lead to substantial morbidity. We performed a systematic review and meta-analysis for R0, adverse-events (AEs) and recurrence between EA, SA and PD. Electronic databases were searched from 1990 to 2018. Outcomes were calculated as pooled means using fixed and random-effects models and the Freeman-Tukey-Double-Arcsine-Proportion-model. We identified 59 independent studies. The pooled R0 rate was 76.6% (71.8–81.4%, I2 = 91.38%) for EA, 96.4% (93.6–99.2%, I2 = 37.8%) for SA and 98.9% (98.0–99.7%, I2 = 0%) for PD. AEs were 24.7% (19.8–29.6%, I2 = 86.4%), 28.3% (19.0–37.7%, I2 = 76.8%) and 44.7% (37.9–51.4%, I2 = 0%), respectively. Recurrences were registered in 13.0% (10.2–15.6%, I2 = 91.3%), 9.4% (4.8–14%, I2 = 57.3%) and 14.2% (9.5–18.9%, I2 = 0%). Differences between proportions were significant in R0 for EA compared to SA (p = 0.007) and PD (p = 0.022). AEs were statistically different only between EA and PD (p = 0.049) and recurrence showed no significance for EA/SA or EA/PD. Our data indicate an increased rate of complete resection in surgical interventions accompanied with a higher risk of complications. However, studies showed various sources of bias, limited quality of data and a significant heterogeneity, particularly in EA studies
CoScience : gemeinsam forschen und publizieren mit dem Netz
Der Arbeitsalltag von Wissenschaftlerinnen und Wissenschaftlern hat sich in den letzten Jahren dramatisch verändert. Forschen, Schreiben und Publizieren sind mittlerweile stark durch netzbasierte Anwendungen geprägt. Das digitale Zeitalter aber hat nicht nur neue technische Werkzeuge hervorgebracht, sondern auch neue Wege eröffnet, um Wissen zu generieren und zu verbreiten. Dies gilt sowohl innerhalb der akademischen Welt als auch über diese hinaus. Das Arbeiten mit dem Netz stellt unsere bisherigen etablierten wissenschaftlichen Praktiken in Frage. Forschung wird zunehmend vernetzt, kollaborativ, multimedial, trans- bzw. interdisziplinär durchgeführt. Das vorliegende Handbuch beschreibt diese sich herausbildenden wissenschaftlichen Praktiken. Ziel der Autoren war es dabei, ein praxisnahes und leicht verständliches Handbuch zu schreiben
A model for the optical high state light curve of AM Herculis
We present a simple quantitative model that can describe the photometric B
and V band light curves of AM Herculis obtained during a high state. The
double-humped shape of the V band light curve is dominated by cyclotron
emission from a region at the main accreting pole with an area of ~5x10e16 cm^2
and sustaining an inflow of ~0.06 g/cm^2/s. The almost unmodulated B band is
dominated by emission from the accretion stream. The contribution of the heated
white dwarf to the optical emission is small in the B band, but comparable to
that of the accretion stream in the V band. The emission of the secondary star
is negligible both in B and in V.Comment: 6 pages A&A-Latex, 6 Figures, accepted for publication in A&
Prognostic Factors for Mortality in Acute Mesenteric Ischemia.
Postoperative mortality in patients undergoing surgical and/or interventional treatment for acute mesenteric ischemia (AMI) has remained an unsolved problem in recent decades. Here, we investigated clinical predictors of postoperative mortality in a large European cohort of patients undergoing treatment for AMI. In total, 179 patients who underwent surgical and/or interventional treatment for AMI between 2009 and 2021 at our institution were included in this analysis. Associations between postoperative mortality and various clinical variables were assessed using univariate and multivariable binary logistic regression analysis. Most of the patients were diagnosed with arterial ischemia (AI; n = 104), while venous ischemia (VI; n = 21) and non-occlusive mesenteric ischemia (NOMI; n = 54) were present in a subset of patients. Overall inhouse mortality was 55.9% (100/179). Multivariable analyses identified leukocytes (HR = 1.08; p = 0.008), lactate (HR = 1.25; p = 0.01), bilirubin (HR = 2.05; p = 0.045), creatinine (HR = 1.48; p = 0.039), etiology (AI, VI or NOMI; p = 0.038) and portomesenteric vein gas (PMVG; HR = 23.02; p = 0.012) as independent predictors of postoperative mortality. In a subanalysis excluding patients with fatal prognosis at the first surgical exploration (n = 24), leukocytes (HR = 1.09; p = 0.004), lactate (HR = 1.27; p = 0.003), etiology (AI, VI or NOMI; p = 0.006), PMVG (HR = 17.02; p = 0.018) and intraoperative FFP transfusion (HR = 4.4; p = 0.025) were determined as independent predictors of postoperative mortality. Further, the risk of fatal outcome changed disproportionally with increased preoperative lactate values. The clinical outcome of patients with AMI was determined using a combination of pre- and intraoperative clinical and radiological characteristics. Serum lactate appears to be of major clinical importance as the risk of fatal outcome increases significantly with higher lactate values
In vitro and in vivo investigation of a thyroid hormone system-specific interaction with triazoles
Alterations in thyroid hormones (TH) and thyroid-stimulating hormone levels are frequently found following exposure to chemicals of concern. Dysregulation of TH levels can severely perturb physiological growth, metabolism, differentiation, homeostasis in the adult and developmental processes in utero. A frequently identified mode of action for this interaction is the induction of hepatic detoxification mechanisms (e.g. SULTs and UGTs), which lead to TH conjugation and elimination and therefore interfere with hormonal homeostasis, fulfilling the endocrine disruptors (EDs) definition. A short-term study in rats with dietary exposure to cyproconazole, epoxiconazole and prochloraz was conducted and hepatocyte hypertrophy, hepatic UGT activity and Phase 1/2 gene expression inductions were observed together with changes in TH levels and thyroid follicular hypertrophy and hyperplasia. To test for specific interaction with the thyroid hormone system, in vitro assays were conducted covering thyroidal I-uptake (NIS), TH transmembranal transport via MCT8 and thyroid peroxidase (TPO) function. Assays for iodothyronine deiodinases (DIO1–DIO3) and iodotyrosine deiodinase (DEHAL1) were included, and from the animal experiment, Dio1 and Dehal1 activities were measured in kidney and liver as relevant local indicators and endpoints. The fungicides did not affect any TH-specific KEs, in vitro and in vivo, thereby suggesting hepatic conjugation as the dominant MoA
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