Selection of the experimental conditions for white-light SRIXE measurements

Synchrotron-radiation-induced X-ray emission has enormous potential as a technique for trace-element analysis. To fully utilize the many advantages of SRIXE measurements, one must optimize the experimental conditions. In this paper the problems associated with the selection of experimental conditions are discussed in theory. In addition, examples of experimental work done at the National Synchrotron Light Source at Brookhaven National Laboratory, USA are presented.     

The clinico-genetic characteristics of the origin and manifestation of colorectal cancer

A clinical and genealogical investigation has been carried out in 169 subjects of both sexes, presenting with colorectal oncopathology. Particular features of the colorectal carcinoma in the patients have been recognized. The frequency of the tumours spread in the relatives of the probands is determined as is the spectrum of aggregation of large intestine carcinoma with neoplasia of other genesis in the pedigrees. The data obtained suggest an important contribution of genetic factors into the origination of colorectal carcinoma.     

The weak link

Public network reliability has become a mandatory issue. In the second quarter of 1991 alone, there were 331 switch-related outages, which affected more than 3.5 million phone lines and lasted an average of 45 minutes each. The carriers are trying but they still represent the ‘Weak Link’ in data and voice communications. There will be improvements but will they be enough?     

American university students' beliefs about success in science: A case study

Atribution theory as a new perspective for studying the psychology of science and scientists is introdced through use of a case study of college students' attributions for success and failure in science. The atributional perspective incorporates views of one's own competence as well as beliefs bout the importance of effort for success in science. It also provides a framework for analyzing differences in attitudes about various fields of science. Sex differences in science participation are a further area which can be analyzed from an atributional perspective. Results from the college student study are discussed along with suggestions for future research.     

Single-Source Oriented Application Level Multicast

1　Introduction　TherearevariousIPmulticastprotocols[1～6] havebeenproposedandstandardized ,butfewofthemhavebeendeployedwidespreadlyintheglobalInter netduetotechnicalandcommercialissues[7] .RE UNITE[8] usesrecursiveunicasttreestoimplementmulticastservicewithoutIPmulticastdelpoyment.Withoutanymodificationofrouters,applicationlev elmulticastapproaches[9～ 1 4 ] usingoverlaynetworkshavebeenproposedasaviablealternativetoIPmul ticast.Theseapproachesusedifferentmetrics (de lay ,bandwidthandoth…     

Phase-polarisation contrast for surface plasmon resonance biosensors

A technique of phase-polarisation contrast (PPC) for the enhancement of the contrast of a surface plasmon resonance (SPR) intensity profile is proposed and experimentally realised. The technique exploits the peculiarities of light phase and polarisation behaviour under SPR. It applies to non-optimum SPR coupling conditions and enables one to lower the resonant minimum of reflected intensity nearly to zero, and hence to increase substantially the ratio of the intensity from the resonance to that at the minimum. We observed the contrast enhancement by more than one order of magnitude when we applied the PPC scheme. The PPC can be efficiently employed in commercial SPR sensors, as it significantly reduces restrictions on allowable parameters of SPR-supporting metal films and biomolecular layers immobilised on them, facilitates SPR observation, and increases the accuracy of SPR shift measurements.     

Anti-CD36 autoantibodies in thrombotic thrombocytopenic purpura and other thrombotic disorders: identification of an 85 kD form of CD36 as a target antigen

The presence of anti-CD36 antibodies in plasma of patients with thrombotic thrombocytopenic purpura (TTP), idiopathic thrombocytopenic purpura (ITP), and heparin-induced thrombocytopenia without/with thrombosis (HIT/HITT) has been examined by immunoblots, and a monoclonal antibody capture assay, the platelet-associated IgG characterization assay (PAICA). Results with PAICA showed that 73% (8/11) of patients with TTP were positive, and 71% (10/14) by immunoblots. With ITP, 20% (6/30) were positive by PAICA and 19% (3/16) by immunoblots; HIT, 30% (3/10) were positive by PAICA and 60% (6/10) by immunoblot; HITT, 50% (2/4) by PAICA and 100% (4/4) by immunoblot. Purification of CD36 by fast protein liquid chromatography (FPLC) from Triton X-100 extracts of normal platelet membranes resulted in the isolation of two different forms: the classic 88 kD form, and a second, lighter 85 kD form. Our data indicated that the patients' plasma autoantibodies reacted strongly with the 85 kD form. Conventional monoclonal and polyclonal antisera produced to the 88 kD form reacted strongly with the 88 kD form but weakly with the 85 kD form. These results confirm the possible importance of anti-CD36 antibodies in the pathophysiology of TTP and other thrombocytopenias and demonstrate the presence of a previously unrecognized target antigen for these antibodies.     

Persistent loss of tyrosine hydroxylase immunoreactivity in the substantia nigra after neuroleptic withdrawal

A 37 year woman developed neuroleptic induced parkinsonism that persisted long after the drug had been discontinued. This prompted a study of the effect of an eight week course of haloperidol (HAL) followed by two week withdrawal, on dopaminergic neurons of the substantia nigra in rats. Animals treated with HAL showed a highly significant 32%-46% loss of tyrosine hydroxylase (TH) immunoreactive neurons in the substantia nigra, and 20% contraction of the TH stained dendritic arbour. Neuroleptic drug induced downregulation of nigral dopaminergic neurons may help to explain the persistent parkinsonism found in many patients after withdrawal of medication.