942 research outputs found
Foot-operated cell-counter
Cell-counter for cell indices consists of a footboard with four pressure sensitive switches and an enclosure for the components and circuitry. This device increases the operators efficiency by reducing the number of required hand movements
Fibre laser hydrophones for cosmic ray particle detection
The detection of ultra high energetic cosmic neutrinos provides a unique
means to search for extragalactic sources that accelerate particles to extreme
energies. It allows to study the neutrino component of the GZK cut-off in the
cosmic ray energy spectrum and the search for neutrinos beyond this limit. Due
to low expected flux and small interaction cross-section of neutrinos with
matter large experimental set-ups are needed to conduct this type of research.
Acoustic detection of cosmic rays may provide a means for the detection of
ultra-high energetic neutrinos. Using relative low absorption of sound in
water, large experimental set-ups in the deep sea are possible that are able to
detect these most rare events, but it requires highly sensitive hydrophones as
the thermo-acoustic pulse originating from a particle shower in water has a
typical amplitude as low as a mPa. It has been shown in characterisation
measurements that the fibre optic hydrophone technology as designed and
realised at TNO provides the required sensitivity. Noise measurements and pulse
reconstruction have been conducted that show that the hydrophone is suited as a
particle detector.Comment: Submitted to the proceedings of "13th Topical Seminar on Innovative
Particle and Radiation Detectors (IPRD13)
Successful Thrombectomy via a Surgically Reopened Umbilical Vein for Extended Portal Vein Thrombosis Caused by Portal Vein Embolization prior to Extended Liver Resection
Selective portal vein embolization (PVE) before extended liver surgery is an accepted method to stimulate growth of the future liver remnant. Portal vein thrombosis (PVT) of the main stem and the non-targeted branches to the future liver remnant is a rare but major complication of PVE, requiring immediate revascularization. Without revascularization, curative liver surgery is not possible, resulting in a potentially life-threatening situation. We here present a new surgical technique to revascularize the portal vein after PVT by combining a surgical thrombectomy with catheter-based thrombolysis via the surgically reopened umbilical vein. This technique was successfully applied in a patient who developed thrombosis of the portal vein main stem, as well as the left portal vein and its branches to the left lateral segments after selective right-sided PVE in preparation for an extended right hemihepatectomy. The advantage of this technique is the avoidance of an exploration of hepatoduodenal ligament and a venotomy of the portal vein. The minimal surgical trauma facilitates additional intravascular thrombolytic therapy as well as the future right extended hemihepatectomy. We recommend this technique in patients with extensive PVT in which percutaneous less invasive therapies have been proven unsuccessful
Social Contacts and the Economic Performance of Immigrants: A Panel Study of Immigrants in Germany
Using data from the German Socio-Economic Panel, we examined the impact of social contacts on immigrant occupational status and income. In addition to general social contacts, we also analyzed the effects of bonding (i.e., co-ethnic) and bridging (i.e., interethnic) ties on economic outcomes. Results show that general social contacts have a positive effect on the occupational status and, in particular, annual income of immigrants. We also find that bridging ties with Germans lead to higher occupational status, but not to increased income. These effects remain visible even when social contacts are measured (at least) one year prior to the economic outcomes, as well as when earlier investments in German human capital are considered. Finally, we show that co-ethnic concentration in the region of residence weakly affects economic returns to German language proficiency and schooling
Multi-layer coating development for XEUS
Graded depth multi-layer coatings have the potential to optimise the performance of X-ray reflective surfaces for improved energy response. A study of deposition techniques on silicon substrates representative of the XEUS High Performance Pore Optics (HPO) technology has been carried out. Measurements at synchrotron radiation facilities have been used to confirm the excellent performance improvements achievable with Mo/Si and W/Si multilayers. Future activities that will be necessary to implement such coatings in the HPO assembly sequence are highlighted. Further coating developments that may allow an optimisation of the XEUS effective area in light of potential changes to science requirements and telescope configurations are also identified. Finally an initial measurement of effects of radiation damage within the multilayers is reported
Actual postoperative protein and calorie intake in patients undergoing major open abdominal cancer surgery:A prospective, observational cohort study
Background Adequate nutritional protein and energy intake are required for optimal postoperative recovery. There are limited studies reporting the actual postoperative protein and energy intake within the first week after major abdominal cancer surgery. The main objective of this study was to quantify the protein and energy intake after major abdominal cancer surgery. Methods We conducted a prospective cohort study. Nutrition intake was assessed with a nutrition diary. The amount of protein and energy consumed through oral, enteral, and parenteral nutrition was recorded and calculated separately. Based on the recommendations of the European Society for Clinical Nutrition and Metabolism (ESPEN), protein and energy intake were considered insufficient when patients received Fifty patients were enrolled in this study. Mean daily protein and energy intake was 0.61 +/- 0.44 g/kg/day and 9.58 +/- 3.33 kcal/kg/day within the first postoperative week, respectively. Protein and energy intake were insufficient in 45 [90%] and 41 [82%] of the 50 patients, respectively. Patients with Clavien-Dindo grade >= III complications consumed less daily protein compared with the group of patients without complications and patients with grade I or II complications. Conclusion During the first week after major abdominal cancer surgery, the majority of patients do not consume an adequate amount of protein and energy. Incorporating a registered dietitian into postoperative care and adequate nutrition support after major abdominal cancer surgery should be a standard therapeutic goal to improve nutrition intake
Selective serotonin reuptake inhibitors in the treatment of generalized anxiety disorder
Selective serotonin reuptake inhibitors have proven efficacy in the treatment of panic disorder, obsessive–compulsive disorder, post-traumatic stress disorder and social anxiety disorder. Accumulating data shows that selective serotonin reuptake inhibitor treatment can also be efficacious in patients with generalized anxiety disorder. This review summarizes the findings of randomized controlled trials of selective serotonin reuptake inhibitor treatment for generalized anxiety disorder, examines the strengths and weaknesses of other therapeutic approaches and considers potential new treatments for patients with this chronic and disabling anxiety disorder
The MRN complex is transcriptionally regulated by MYCN during neural cell proliferation to control replication stress
The MRE11/RAD50/NBS1 (MRN) complex is a major sensor of DNA double strand breaks, whose role in controlling faithful DNA replication and preventing replication stress is also emerging. Inactivation of the MRN complex invariably leads to developmental and/or degenerative neuronal defects, the pathogenesis of which still remains poorly understood. In particular, NBS1 gene mutations are associated with microcephaly and strongly impaired cerebellar development, both in humans and in the mouse model. These phenotypes strikingly overlap those induced by inactivation of MYCN, an essential promoter of the expansion of neuronal stem and progenitor cells, suggesting that MYCN and the MRN complex might be connected on a unique pathway essential for the safe expansion of neuronal cells. Here, we show that MYCN transcriptionally controls the expression of each component of the MRN complex. By genetic and pharmacological inhibition of the MRN complex in a MYCN overexpression model and in the more physiological context of the Hedgehog-dependent expansion of primary cerebellar granule progenitor cells, we also show that the MRN complex is required for MYCN-dependent proliferation. Indeed, its inhibition resulted in DNA damage, activation of a DNA damage response, and cell death in a MYCN- and replication-dependent manner. Our data indicate the MRN complex is essential to restrain MYCN-induced replication stress during neural cell proliferation and support the hypothesis that replication-born DNA damage is responsible for the neuronal defects associated with MRN dysfunctions.Cell Death and Differentiation advance online publication, 12 June 2015; doi:10.1038/cdd.2015.81
DNA resection in eukaryotes: deciding how to fix the break
DNA double-strand breaks are repaired by different mechanisms, including homologous
recombination and nonhomologous end-joining. DNA-end resection, the first step in
recombination, is a key step that contributes to the choice of DSB repair. Resection, an
evolutionarily conserved process that generates single-stranded DNA, is linked to checkpoint
activation and is critical for survival. Failure to regulate and execute this process results in
defective recombination and can contribute to human disease. Here, I review recent findings on
the mechanisms of resection in eukaryotes, from yeast to vertebrates, provide insights into the
regulatory strategies that control it, and highlight the consequences of both its impairment and its
deregulation
Hunt for new phenomena using large jet multiplicities and missing transverse momentum with ATLAS in 4.7 fb−1 of s√=7TeV proton-proton collisions
Results are presented of a search for new particles decaying to large numbers of jets in association with missing transverse momentum, using 4.7 fb−1 of pp collision data at s√=7TeV collected by the ATLAS experiment at the Large Hadron Collider in 2011. The event selection requires missing transverse momentum, no isolated electrons or muons, and from ≥6 to ≥9 jets. No evidence is found for physics beyond the Standard Model. The results are interpreted in the context of a MSUGRA/CMSSM supersymmetric model, where, for large universal scalar mass m 0, gluino masses smaller than 840 GeV are excluded at the 95% confidence level, extending previously published limits. Within a simplified model containing only a gluino octet and a neutralino, gluino masses smaller than 870 GeV are similarly excluded for neutralino masses below 100 GeV
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