Determination of the Neutron Lifetime Using Magnetically Trapped Neutrons

We report progress on an experiment to measure the neutron lifetime using magnetically trapped neutrons. Neutrons are loaded into a 1.1 T deep superconducting Ioffe-type trap by scattering 0.89 nm neutrons in isotopically pure superfluid ⁴He. Neutron decays are detected in real time using the scintillation light produced in the helium by the beta-decay electrons. The measured trap lifetime at a helium temperature of 300 mK and with no ameliorative magnetic ramping is substantially shorter than the free neutron lifetime. This is attributed to the presence of neutrons with energies higher than the magnetic potential of the trap. Magnetic field ramping is implemented to eliminate these neutrons, resulting in an 833−63+74s trap lifetime, consistent with the currently accepted value of the free neutron lifetime.     

On the physical meaning of the dispersion equation and its solutions for different initial and boundary conditions

lt is shown that similarly to the movement in capillaries, also in other dispersive systems, the distinction between the concentration of solute in resIt is also shown how particular solutions are related by known and new transformations. Time and spatial moments of all solutions as well as changes ofTo make the paper more general all the considerations are performed in normal time and space variables. However, a change to dimensionless variables, gThe paper deals only with solutions for infinite and semi-infinite media in the case of a conservative tracer. However, there is no doubt that the appl     

Serum affinity chromatography for the detection of IgG alloantibodies in a patient with high-titer IgM cold agglutinins

Although infantile hypertrophic pyloric stenosis (IHPS) is the most common condition requiring surgery in the first few months of life, its pathogenesis is not fully understood. Reviews of the recent progress in the pathogenesis of IHPS show: (1) there is increasing evidence to suggest that smooth-muscle cells in IHPS are not properly innervated; (2) because non-adrenergic, non-cholinergic nerves are mediators of smooth-muscle relaxation, it is likely that the absence of these nerves in pyloric muscle is the cause of excessively contracted hypertrophic circular pyloric muscle; (3) there are abnormal amounts of extracellular matrix proteins in hypertrophic pyloric muscle. Circular muscle cells in IHPS are actively synthesizing collagen, and this may be responsible for the characteristic "firm" nature of the pyloric tumor; and (4) the increased expression of insulin-like growth factor-I, transforming growth factor-beta 1, and platelet-derived growth factor-BB and their receptors in hypertrophic pyloric muscle suggests that increased local synthesis of growth factors may play an important role in smooth-muscle hypertrophy in IHPS.     

Cytotoxic Activity of LLO Y406A Is Targeted to the Plasma Membrane of Cancer Urothelial Cells

Identification of novel agents for bladder cancer treatment is highly desirable due to the high incidence of tumor recurrence and the risk of progression to muscle-invasive disease. The key feature of the cholesterol-dependent toxin listeriolysin O mutant (LLO Y406A) is its preferential activity at pH 5.7, which could be exploited either directly for selective targeting of cancer cells or the release of accumulated therapeutics from acidic endosomes. Therefore, our goal was to compare the cytotoxic effect of LLO Y406A on cancer cells (RT4) and normal urothelial cells (NPU), and to identify which cell membranes are the primary target of LLO Y406A by viability assays, life-cell imaging, fluorescence, and electron microscopy. LLO Y406A decreased viability, altered cell morphology, provoked membrane blebbing, and induced apoptosis in RT4 cells, while it did not affect NPU cells. LLO Y406A did not cause endosomal escape in RT4 cells, while the plasma membrane of RT4 cells was revealed as the primary target of LLO Y406A. It has been concluded that LLO Y406A has the ability to selectively eliminate cancer urothelial cells through pore-forming activity at the plasma membrane, without cytotoxic effects on normal urothelial cells. This promising selective activity merits further testing as an anti-cancer agent.     

可靠性和维修性——现代设计的关键因素（一）

提高利润的压力迫使管理人员不得不改进技术以降低资产管理成本,这改变了维修人员和维修操作的地位。日益复杂的技术系统、公众对产品质量的要求以及关于产品责任的新法律等也进一步推进了可靠性和维修性的发展。本文描述了可靠性和维修性在总体设计中的地位以及其对寿命周期费用和总体设备效率的影响,列举了一些实际可行的可靠性和维修性的评估方法,并给出了一些实例。最后简单地介绍了一些系统方法在斯洛文尼亚“早期设备管理”领域的基本运用和早期成果。     

Adapting metric indexes for searching in multi-metric spaces

An important research issue in multimedia databases is the retrieval of similar objects. For most applications in multimedia databases, an exact search is not meaningful. Thus, much effort has been devoted to develop efficient and effective similarity search techniques. A recent approach that has been shown to improve the effectiveness of similarity search in multimedia databases resorts to the usage of combinations of metrics (i.e., a search on a multi-metric space). In this approach, the desirable contribution (weight) of each metric is chosen at query time. It follows that standard metric indexes cannot be directly used to improve the efficiency of dynamically weighted queries, because they assume that there is only one fixed distance function at indexing and query time. This paper presents a methodology for adapting metric indexes to multi-metric indexes, that is, to support similarity queries with dynamic combinations of metric functions. The adapted indexes are built with a single distance function and store partial distances to estimate the dynamically weighed distances. We present two novel indexes for multimetric space indexing, which are the result of the application of the proposed methodology.     

Identification,in vitro and in vivo Antioxidant Activity,and Gastrointestinal Stability of Lignans from Silver Fir (Abies alba) Wood Extract

Lignans are generally known for their beneficial impact on human health. In this study, we found that the water extract of silver fir (Abies alba) wood contains lignans, which constitute approximately 10% of the extract and include isolariciresinol, hydroxymatairesinol, secoisolariciresinol, lariciresinol, pinoresinol, and matairesinol. The antioxidant activity of the extract was measured by several in vitro assays and an assay in a eukaryotic cell model (yeast). The extract had greater in vitro antioxidative activity than ascorbic acid, resveratrol, or butylated hydroxytoluene (BHT) and similar antioxidative activity to epigallocatechin gallate. The intracellular antioxidant effect in the yeast gave indirect evidence that the components of the silver fir wood extract (SFWE) effectively pass through eukaryotic cell membranes and have higher in vivo antioxidative activity than ascorbic acid, resveratrol, tocopheryl succinate, or BHT and similar to epigallocatechin gallate. The in vitro gastrointestinal digestion of the lignans in the extract is not significant; therefore, it is reasonable to expect antioxidative effects from orally applied SFWE.     

Cell Growth-Inhibiting Properties of Selected Carrier-Bound, Monoamine-Coordinated Platinum(II) Compounds

In contradistinction to the ligand arrangement in coordination compounds of the square-planar cis-diamminedichloroplatinum(II) type as represented by the prototype anticancer drug cisplatin, scant attention has been paid in cancer research to those platinum complexes in which only a single amino group (in addition to different ligands) is coordinated to the metal. In continuation of earlier research in this laboratory focused on macromolecular compounds containing monoamine-coordinated platinum, we have now synthesized a series of such polymeric platinum conjugates and assessed their antiproliferative activity in cell culture tests conducted against several human cancer cell lines. Conjugates containing hydroxylated side groups as hydrosolubilizing entities are found to exhibit poor, or no, activity up to the highest drug concentration tested (50 g Pt/mL). In contrast, those conjugates in which the solubilizing units are characterized by the presence of potentially cationic tert-amine side chain terminals show remarkably high cell-killing activity, with IC₅₀ in the range of 1–6 g Pt/mL against the HeLa cervical epitheloid carcinoma line. Two selected samples tested against the A-2780 human ovarian cancer line and its cisplatin-resistant A-2780-cis counterpart shows lack of cross-resistance with cisplatin (resistance factor 1). These findings augur well for the development of polymer-conjugated monoamine-coordinated platinum compounds with carcinostatic properties.     

Follow-up in 103 patients with catecholamine-secreting tumours

BACKGROUND: It is necessary to have an easy and quickly test to distinguish "false positive" rubella IgM results and residual antibodies from the antibodies produced in the primary infection, in pregnant women. The avidity of IgG antibodies test seems to differentiate between primary rubella infection and past infections, reinfections or postvaccination, showing its utility in the diagnosis of primary infection in other infectious diseases. METHOD: For 30 months, 178 sera from 157 patients with clinical and/or epidemiological rubella suspicion or with a positive rubella IgM result as result of an accidental serological finding, were remitted to our laboratory for a serological follow up. We distinguished 3 patient groups: outbreak group, 112; pregnant women, 36, and newborn 11. Rubella IgM antibodies by indirect EIA previous the rheumatoid factor absorption; IgG antibodies of low avidity by indirect EIA previous treatment of serum with 6 M urea, were detected in the sera. It considered a positive result, a rubella avidity index (AI) < 50%. RESULTS: In the epidemic outbreak group, 90.2% of the patients were not vaccinated. 80% of cases occurred in young men between 14 an 20 years old. From 109 patients (97.3%) with rubella IgG antibodies, 92 (84.4%) showed AI-IgG lower than 50%. In this group, the mean rate of AI-IgG rubella was 29.0%. In the pregnant women group, except for two of them, rubella IgM antibodies were an accidental finding in a serological pregnancy screening. Thirty patients (83.8%) showed AI-IgG rubella > 50%. The two pregnant women who had evidence of clinical and epidemiological rubella showed AI-IgG rubella of 37.4% and 20.9%. Another four pregnant women showed AI-IgG rubella close to cut-off (44.7-49.0%). The mean AI-IgG rubella in this group was 71.8%. The mean AI-IgG Rubella between the epidemic outbreak group and the pregnant women group, 29.0 and 71.8% respectively, was statistical significance (p < 0.001). CONCLUSIONS: The avidity IgG test is simple and quickly, and it allow to exclude most of positive results because of residual IgM antibodies and false reactive.