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1.
Capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) is a promising new method for the analysis of protein sequencing products. It gives 10 zmol (1 zmol = 10(-21) mol) limits of detection (3 sigma) for fluorescein thiohydantoin (FTH) amino acids. We have developed a separation for the (FTH)-amino acid products generated from 18 of the 20 coded amino acids. The extremely low volume requirement associated with CE-LIF makes it incompatible with commercial sequencers. For this reason, we have also been developing a miniaturized sequencer that can be more easily coupled to our detection system. Both the CE-LIF system and the miniaturized sequencer are described.  相似文献   
2.
Central nervous system (CNS) disease is a major feature of simian immunodeficiency virus (SIV) infection of macaques. To define the spectrum of CNS lesions in SIV-infected macaques and the potential associations with viral strain and disease course, we performed a retrospective analysis of necropsies on 124 macaques with SIV-induced AIDS. Histologic evidence of CNS disease was observed in 71 (57.3%) of the 124 animals. SIV encephalitis was the most common CNS lesion occurring in 43.7% (31/71) of the animals with CNS disease and 25% of all animals. The incidence of SIVE correlated significantly with shortened survival (P=0.0207). In addition, SIVE was seen in 42.9% (15/35) of rapid progressors (animals that died within 200 days) compared to only 18% (16/89) of normal progressors (animals that lived longer than 200 days) (P=0.011). Animals with SIVE had higher viral loads in peripheral blood than those that did not, but this difference did not reach statistical significance. Similarly, while animals infected with uncloned SIVmac251 had a higher incidence of SIVE (27.5%; 14/51) than animals infected with molecularly cloned SIVmac239 and its T-cell tropic derivatives (18.5%; 10/54) this difference was not statistically significant. In this study rapid disease progression and SIVE were highly correlated making separation of viral determinants of virulence from those of neurovirulence difficult.  相似文献   
3.
Abstract— The current status of AC powder electroluminescent (ACPEL) displays is reviewed with particular emphasis given to color and lifetime. The printing of the displays in forward and reverse architectures is also discussed, in addition to the fabrication of ACPEL displays with interdigitated electrodes, and different types of ACPEL phosphors and materials for back electrodes, transparent conducting electrodes, binders, and dielectrics are considered. Furthermore, shape conformable and highly flexible ACPEL displays are surveyed.  相似文献   
4.
Liquid marbles may be traditionally formed by rolling a droplet on a bed of non-wetting particles resulting in encapsulation and stabilisation. Particles used in this process may range from nanometre to millimetre if handled with sufficient care. This method, however, runs the risk of droplet coalescence and is limited to non-wetting particles. Currently there exist some alternative methods of formulation including using electrostatics to either deliver a particle bed to the droplet or pull the droplet to the particles. The former has shown some promise in potential batch processes but is hindered by interparticle forces. Additional production methods include a form of blender, but this has shown to be unable to produce marbles of a narrow size distribution. Once formed, liquid marbles have demonstrated value as potential blood typing devices, as micro-reaction vessels due to the inherent barrier between the internal phase and the substrate whilst maintaining gas permeability, and as contaminant sensors. Liquid marbles also demonstrate a remarkable level of elasticity under compressive force and reduced evaporation rates when compared to bare water droplets, a function of the size and composition of the stabilising particles. In addition to this, liquid marbles have been proposed as actuators. Locomotion may easily be induced in these structures, using electrostatics, sound, magnetism or light depending on the particle/liquid combinations used in formation, and the environment of deployment. This review seeks to present and summarise recent advances in the field of liquid marble manufacture and methods for actuation. We also aim to highlight potential future avenues of further study within this arena.  相似文献   
5.
Using automated reasoning techniques, we tackle the niche activity of proving that a program is free from run-time exceptions. Such a property is particularly valuable in high integrity software, for example, safety- or security-critical applications. The context for our work is the SPARK Approach for the development of high integrity software. The SPARK Approach provides a significant degree of automation in proving exception freedom. Where this automation fails, however, the programmer is burdened with the task of interactively constructing a proof and possibly also having to supply auxiliary program annotations. We minimize this burden by increasing the automation, through an integration of proof planning and a program analysis oracle. We advocate a ‘cooperative’ integration, where proof-failure analysis directly constrains the search for auxiliary program annotations. The approach has been successfully tested on industrial data.  相似文献   
6.
In a previous letter, a matrix ?0 was introduced, and an algorithm was derived for its inversion. The inverse matrix is shown in this letter to be simply related to the characteristic polynomial of the shift-register circuit. Those shift-register configurations which are most amenable to the matrix method for generating delayed sequences are discussed.  相似文献   
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8.
The variable absorption of melphalan from the gastrointestinal tract results in response rates between 40 and 60%. High dose melphalan increases response rates but at the cost of increased morbidity and mortality. We have investigated intravenous intermediate dose melphalan and dexamethasone in the treatment of patients presenting with de novo multiple myeloma with the object of reducing toxicity while preserving an improved response rate compared to oral melphalan and prednisolone. The results show that this treatment can be delivered safely on an outpatient basis in patients up to the age of 78 yr; 82% of patients achieved an objective response and 30% a complete haematological and clinical remission. Median overall survival for the whole group is 37 months.  相似文献   
9.
Transforming growth factor beta1 (TGF-beta1) regulates both cell growth and cellular plasticity and is therefore important in the molecular control of both the developmental and neoplastic processes. It has been suggested that TGF-beta1 may be a positive or negative regulator of tumorigenesis. Stimulation of tumorigenesis could be due to its action as an immunosuppressor or as an inducer of angiogenesis, or by its direct action on the cell in promoting cellular plasticity. In the current study, we provide evidence that TGF-beta1 can act directly on keratinocytes in vivo to induce the reversible epithelial-mesenchymal conversion of a malignant metastatic keratinocyte cell line. Two squamous clones from the cell line were shown to undergo a reversible conversion to a fibroblastoid phenotype after culture in 1 ng/ml TGF-beta1. The morphological conversion became apparent at 24 h post-TGF-beta treatment and was complete after another 24 h. The conversion was characterized by a rapid delocalization of E-cadherin within 6-12 h posttreatment, followed by down-regulation of E-cadherin levels by 72 h. These squamous clones spontaneously converted to a fibroblastoid phenotype after s.c. injection in nude mice. Importantly, four of four clones that had been stably transfected with a dominant negative TGF-beta type II receptor were unable to undergo this mesenchymal switch in vivo, despite the fact that all clones stably transfected with neomyocin resistance alone retained their spindle characteristics in vivo. This demonstrates that the epithelial-mesenchymal conversion event is mediated directly via the TGF-beta signaling pathway of the tumor cell per se, and that it is sufficient to significantly enhance tumorigenicity and the malignant and invasive characteristics of the tumor in vivo.  相似文献   
10.
The author suggests that anxiety disorders are related to a deficiency in the endogenous opioid system. The author classifies deficiencies of the endogenous opioid system as congenital or acquired, and also as real or relative. Individuals with 'real deficiency' cannot function adequately in any situations, including situations which are natural for human beings. Persons with 'relative deficiency' are unable to function adequately under circumstances which are unnatural for humans: their 'adaptational reserve' is insufficient. The use of opioid substances and alcohol is a form of self-medication to reduce anxiety. Acupuncture and its variations, psychotherapy, and the administration of placebo can decrease anxiety because these therapeutic maneuvers activate the endogenous opioid system.  相似文献   
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