12,227 research outputs found
Application of Neural Networks for Energy Reconstruction
The possibility to use Neural Networks for reconstruction of the energy
deposited in the calorimetry system of the CMS detector is investigated. It is
shown that using feed - forward neural network, good linearity, Gaussian energy
distribution and good energy resolution can be achieved. Significant
improvement of the energy resolution and linearity is reached in comparison
with other weighting methods for energy reconstruction.Comment: 18 pages, 13 figures, LATEX, submitted to: Nuclear Instruments &
Methods
Preface
This special issue contains selected papers from the 18th European Symposium of Computer Aided Process Engineering (ESCAPE-18) which took place in Lyon, France, 1–4 June 2008. ESCAPE-18 was the 667th event of the European Federation of Chemical Engineering (EFCE) under responsibility of its CAPE Working Party. CAPE refers to computer aided methods, algorithms and techniques related to process and product engineering. The ESCAPE series brings the latest innovations and achievements by leading professionals from the industrial and academic communities. It serves as a forum for engineers, scientists, researchers, managers and students from academia and industry to present and discuss progress being made in the area of CAPE
Unsymmetrical, cyclic diborenes and thermal rearrangement to a borylborylene
Cyclic diboranes(4) based on a chelating monoanionic benzylphosphine linker were prepared by boron-silicon exchange between arylsilanes and B2Br4. Coordination of Lewis bases to the remaining sp2 boron atom yielded unsymmetrical sp3-sp3 diboranes, which were reduced with KC8 to their corresponding trans-diborenes. These compounds were studied by a combination of spectroscopic methods, X-ray diffraction and DFT calculations. PMe3-stabilized diborene 6 was found to undergo thermal rearrangement to gem-diborene 8. DFT calculations on 8 reveal a polar boron-boron bond, and indicate that the compound is best described as a borylborylene
Size-Dependent Tile Self-Assembly: Constant-Height Rectangles and Stability
We introduce a new model of algorithmic tile self-assembly called
size-dependent assembly. In previous models, supertiles are stable when the
total strength of the bonds between any two halves exceeds some constant
temperature. In this model, this constant temperature requirement is replaced
by an nondecreasing temperature function that depends on the size of the smaller of the two halves. This
generalization allows supertiles to become unstable and break apart, and
captures the increased forces that large structures may place on the bonds
holding them together.
We demonstrate the power of this model in two ways. First, we give fixed tile
sets that assemble constant-height rectangles and squares of arbitrary input
size given an appropriate temperature function. Second, we prove that deciding
whether a supertile is stable is coNP-complete. Both results contrast with
known results for fixed temperature.Comment: In proceedings of ISAAC 201
Engineering a small HOMO-LUMO gap and intramolecular C-H borylation by diborene/anthracene orbital intercalation
The diborene 1 was synthesized by reduction of a mixture of 1,2-di-9-anthryl-1,2-dibromodiborane(4) (6) and trimethylphosphine with potassium graphite. The X-ray structure of 1 shows the two anthryl rings to be parallel and their π(C14) systems perpendicular to the diborene π(B=B) system. This twisted conformation allows for intercalation of the relatively high-lying π(B=B) orbital and the low-lying π* orbital of the anthryl moiety with no significant conjugation, resulting in a small HOMO-LUMO gap (HLG) and ultimately an anthryl C-H borylation. The HLG of 1 was estimated to be 1.57 eV from the onset of the long wavelength band in its UV-vis absorption spectrum (THF, λonset = 788 nm). The oxidation of 1 with elemental selenium afforded diboraselenirane 8 in quantitative yield. By oxidative abstraction of one phosphine ligand by another equivalent of elemental selenium, the B-B and C1-H bonds of 8 were cleaved to give the cyclic 1,9-diborylanthracene 9
Embolization in an adrenocortical carcinoma as palliative therapy
Background: With an annual incidence of 0.2% of new cases per 100,000 inhabitants, adrenocortical carcinoma is rare. In advanced tumor only palliative treatment modalities are practicable. Because of scarcity of the tumor, standard treatment has not been defined. The decision on therapy frequently depends on the individual situation. Tumor embolization and chemotherapy are amongst the possible options. Patient and Methods: We report on a case of a 32-year-old female patient with a large-volume hormonally active adrenocortical carcinoma and hematogenous liver metastases. This carcinoma was confirmed histologically by means of liver biopsy. Owing to the large tumor extent and metastatic spreading and also in view of the poor general condition of the patient, curative surgical therapy was not possible. For this reason, a local approach was chosen primarily with transarterial tumor embolization at the capillary level. Systemic chemotherapy was given afterwards. Results: Improvement of the patient's general condition, especially the pronounced pain symptoms, could be achieved for a short time by the embolization: both, the patient's clinical condition and the laboratory test parameters improved. However, a rapid tumor progression occured under chemotherapy, which was started after embolization. Conclusion: In advanced adrenocortical carcinoma, tumor embolization can lead to a stabilization of the disease and improvement of the symptoms as appraised by palliative criteria in some patients
Association of a MET genetic variant with autism-associated maternal autoantibodies to fetal brain proteins and cytokine expression.
The contribution of peripheral immunity to autism spectrum disorders (ASDs) risk is debated and poorly understood. Some mothers of children with ASD have autoantibodies that react to fetal brain proteins, raising the possibility that a subset of ASD cases may be associated with a maternal antibody response during gestation. The mechanism by which the maternal immune system breaks tolerance has not been addressed. We hypothesized that the mechanism may involve decreased expression of the MET receptor tyrosine kinase, an ASD risk gene that also serves as a key negative regulator of immune responsiveness. In a sample of 365 mothers, including 202 mothers of children with ASD, the functional MET promoter variant rs1858830 C allele was strongly associated with the presence of an ASD-specific 37+73-kDa band pattern of maternal autoantibodies to fetal brain proteins (P=0.003). To determine the mechanism of this genetic association, we measured MET protein and cytokine production in freshly prepared peripheral blood mononuclear cells from 76 mothers of ASD and typically developing children. The MET rs1858830 C allele was significantly associated with MET protein expression (P=0.025). Moreover, decreased expression of the regulatory cytokine IL-10 was associated with both the MET gene C allele (P=0.001) and reduced MET protein levels (P=0.002). These results indicate genetic distinction among mothers who produce ASD-associated antibodies to fetal brain proteins, and suggest a potential mechanism for how a genetically determined decrease in MET protein production may lead to a reduction in immune regulation
Does enternal nutrition affect clinical outcome? A systematic review of the randomized trials
Background: Both parenteral nutrition (PN) and enteral nutrition (EN) are widely advocated as adjunctive care in patients with various diseases. A systematic review of 82 randomized controlled trials (RCTs) of PN published in 2001 found little, if any, effect on mortality, morbidity, or duration of hospital stay; in some situations, PN increased infectious complication rates. Objective: To assess the effect of EN or volitional nutrition support (VNS) in individual disease states from available randomized controlled trials (RCTs). Design: We conducted a systematic review. RCTs comparing EN or VNS to untreated controls, or comparing EN to PN, were identified and separated according to the underlying disease state. Meta-analysis was performed when at least 3 RCTs provided data. The evidence from the RCTs was summarized into one of five grades. A or B indicated the presence of strong or weak (low quality RCTs) evidence supporting the use of the intervention. C indicated a lack of adequate evidence to make any decision about efficacy. D indicated that limited data could not support the intervention. E indicated either that strong data found no effect, or that either strong or weak data suggested that the intervention caused harm. Patients and settings: RCTs could include either hospitalized or non-hospitalized patients. The EN or VNS had to be provided as part of a treatment plan for an underlying disease process. Interventions: The RCT had to compare recipients of either EN or VNS to controls not receiving any type of artificial nutrition or had to compare recipients of EN with recipients of PN. Outcome measures: Mortality, morbidity (disease-specific), duration of hospitalization, cost, or interventional complications. Summary of grading: A – No indication was identified. B – EN or VNS in the perioperative patient or in patients with chronic liver disease; EN in critically ill patients or low birth weight infants (trophic feeding); VNS in malnourished geriatric patients. (The low quality trials found a significant difference in survival favoring the VNS recipients in the malnourished geriatric patient trials; two high quality trials found non-significant differences that favored VNS as well.) C – EN or VNS in liver transplantation, cystic fibrosis, renal failure, pediatric conditions other than low birth weight infants, well-nourished geriatric patients, non-stroke neurologic conditions, AIDS; EN in acute pancreatitis, chronic obstructive pulmonary disease, non-malnourished geriatric patients; VNS in inflammatory bowel disease, arthritis, cardiac disease, pregnancy, allergic patients, preoperative bowel preparation D – EN or VNS in patients receiving non-surgical cancer treatment or in patients with hip fractures; EN in patients with inflammatory bowel disease; VNS in patients with chronic obstructive pulmonary disease E – EN in the first week in dysphagic, or VNS at any time in non-dysphagic, stroke patients who are not malnourished; dysphagia persisting for weeks will presumably ultimately require EN. Conclusions: There is strong evidence for not using EN in the first week in dysphagic, and not using VNS at all in non-dysphagic, stroke patients who are not malnourished. There is reasonable evidence for using VNS in malnourished geriatric patients. The recommendations to consider EN/VNS in perioperative/liver/critically ill/low birth weight patients are limited by the low quality of the RCTs. No evidence could be identified to justify the use of EN/VNS in other disease states
The Igf2as Transcript is Exported into Cytoplasm and Associated with Polysomes
Murine insulin-like growth factor 2 antisense (Igf2as) transcripts originate from the opposite strand of the same Igf2 locus as the Igf2 sense mRNA. The Igf2, insulin 2 (Ins2), and H19 genes form a cluster of imprinted genes on chromosome 7. Loss of imprinting of IGF2 in humans is associated with Beckwith-Wiedemann syndrome and Silver-Russell syndrome, as well as with Wilm's tumor and colorectal cancer. We developed a RNA-FISH protocol to detect Igf2as and Igf2 transcripts. The results from the RNA-FISH were confirmed with quantitative real-time PCR and clearly indicate that the Igf2as transcripts are predominantly located in the cytoplasm of C2C12 cells. In a polysome association study, we showed that the Igf2as sedimented with polysomes in a sucrose gradient. The cellular localization of Igf2as transcripts together with polysome fractionation analysis provides compelling evidence that the Igf2as is protein codin
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