Inflammatory polyarthritis in the community is not a benign disease: predicting functional disability one year after presentation

OBJECTIVE: To predict which patients with early inflammatory polyarthritis presenting to primary care will be functionally disabled one year after presentation, in order to inform treatment and referral decisions. METHODS: The study population consisted of 381 patients notified to the Norfolk Arthritis Register, a primary care based inception cohort of patients with inflammatory polyarthritis. Patients were regarded as functionally disabled if they had a Health Assessment Questionnaire (HAQ) score of one or more. Clinical, laboratory, and demographic variables easily measured at baseline were analyzed for their ability to predict future disability. Recursive partitioning was used to create a simple decision tree to predict those patients who would be disabled at one year. A logistic regression model was generated on a sample of 277 patients and tested on an independent sample of 104 patients. This was compared with other models, one of which consisted of the 1987 ARA criteria. RESULTS: 112 (29%) patients had a HAQ score of at least 1 at one year. The strongest predictors of future disability were a high baseline HAQ, large joint involvement, female sex, and longer disease duration. The decision tree predicted disability accurately in 67% of patients. CONCLUSION: It is possible to predict functional outcome at one year among patients with early inflammatory polyarthritis presenting to primary care using simple clinical variables measured at baseline. Satisfying the 1987 ARA criteria could not be used to predict future disability.     

Biodegradation of phenols by the alga Ochromonas danica

The eukaryotic alga Ochromonas danica, a nutritionally versatile, mixotrophic chrysophyte, grew on phenol as the sole carbon source in axenic culture and removed the phenol carbon from the growth medium. Respirometric studies confirmed that the enzymes involved in phenol catabolism were inducible and that the alga oxidized phenol; the amount of oxygen consumed per mole of oxidized substrate was approximately 65% of the theoretical value. [U-14C]phenol was completely mineralized, with 65% of the 14C label appearing as 14CO2, approximately 15% remaining in the aqueous medium, and the rest accounted for in the biomass. Analysis of the biomass showed that 14C label had been incorporated into the protein, nucleic acid, and lipid fractions; phenol carbon is thus unequivocally assimilated by the alga. Phenol-grown cultures of O. danica converted phenols to the corresponding catechols, which were further metabolized by the meta-cleavage pathway. This surprising result was rigorously confirmed by taking the working stock culture through a variety of procedures to check that it was axenic and repeating the experiments with algal extracts. This is, as far as is known, the first definitive identification of the meta-cleavage pathway for aromatic ring degradation in a eukaryotic alga, though its incidence in other eukaryotes has been (infrequently) suggested.     

Isolation,identification, and synthesis of the sex pheromone of the tobacco budworm

The sex attractant of adult tobacco budworms,Heliothis virescens (F.) was isolated from ether washes of “calling” females and verified as active by field cage bioassays. The components of the pheromone were identified as (Z)-11-hexadecenal and (Z)-9-tetradecenal by spectroscopic and microdegradative methods. The two components are inactive when tested separately, but when they are mixed in the ratio in which they occur in female washes (16∶1, respectively), the synthesized mixture is equivalent to the natural one in attracting males in large cages. In field tests, 53 μg of synthesized mixture was competitive with four live females.     

High field transport in GaAs,InP and InAs

Calculations of the steady state and transient electron drift velocities and impact ionization rate are presented for GaAs, InP and InAs based on a Monte Carlo simulation using a realistic band structure derived from an empirical pseudopotential. The impact ionization results are obtained using collision broadening of the initial state and are found to fit the experimental data well through a wide range of applied fields. In InP the impact ionization rate is much lower than in GaAs and no appreciable anisotropy has been observed. This is due in part to the larger density of states in InP and the corresponding higher electron-phonon scattering rate. The transient drift velocities are calculated under the condition of high energy injection. The results for InP show that higher velocities can be obtained over 1000–1500 Å device lengths for a much larger range of launching energies and applied electric fields than in GaAs. For the case of InAs, due to the large impact ionization rate, high drift velocities can be obtained since the ionization acts to limit the transfer of electrons to the satellite minima. In the absence of impact ionization, the electrons show the usual runaway effect and transfer readily occurs, thus lowering the drift velocity substantially.     

The structure of epitaxial overgrowths of Cu2S formed on (111) Cu

Overgrowths of Cu₂S were formed on (111) single-crystal films of copper by exposing them to sulfur vapor in the temperature range 25–300 °C. Reflection high energy electron diffraction (RHEED) analysis revealed that the resultant overgrowths were epitaxial and of various structural forms depending predominantly on the duration of exposure and not on the temperature. The overgrowth started as a cubic form of Cu₂S but transformed to the hexagonal form and finally to the orthorhombic form. The morphology of the Cu₂S indicated by RHEED, scanning electron microscopy and transmission electron microscopy proceeds from a smooth flat structure to an island-type formation.     

Malfunction detection of nuclear reactor by dynamic data system methodology

A new time series modeling technique called Dynamic Data System (DOS) is applied to malfunction detection of the nuclear reactor by using operating neutron flux data. An AR(1) model and an ARMA (5,4) model are found adequate to characterize the normal and abnormal data respectively of fuel cycle #14, #15, and #16 from the High Flux Isotope Reactor (HFIR). Using an AR(1) model the time of malfunction occurring at the 13th day of cycle #15 is detected by the estimated parameter. A malfunction detection scheme employing control chart is developed for diagnosis, surveillance and early malfunction detection of the reactor system for online application. A control chart is established from cycle #14 data and tested on cycle #15 and #16. It is shown that malfunction is clearly detected in cycle #15 while cycle #16 is free from malfunction.     

CONCUR: A language for continuous, concurrent processes

Hendrix's robot modeling system presented a simulation method in which time is represented as a continuous phenomenon. This paper introduces the language CONCUR, which realizes Hendrix's concept through an extension of the LISP environment. CONCUR uses generalized procedures (scenarios) operating in a data-driven mode to implement Hendrix's events. The heart of CONCUR is a generalized pattern-matcher which permits operators within the patterns to bind variables and modify the match process. We include several detailed examples in addition to an implementation of the pattern matcher.     

Comments on 'Increasing film-focus distance (FFD) reduces radiation dose for X-ray examinations' by P.C. Brennan, S. McDonnell and D. O'Leary

Sir, Comments on ‘Increasing film-focus distance (FFD) reducesradiation dose for X-ray examinations’ by P.C. Brennan,S. McDonnell and D. O'Leary. In a recent publication, Brennan et al.⁽¹⁾ claim that increasingthe film-focus distance (FFD) from 100 to 130 cm will reduceeffective doses (E) by 33% for a pelvic X-ray examination. Thisconclusion is based on a reported 33% reduction in the entrancesurface dose (ESD), by the use of the same effective dose perunit ESD conversion coefficient (E/ESD) at both FFD values.However, E/ESD values are only valid for the specific     

Entrapment of fluorescent signaling DNA aptamers in sol-gel-derived silica

We report on the first successful immobilization of a DNA aptamer, in particular, a fluorescence-signaling DNA aptamer, within a sol-gel-derived matrix. The specific aptamer examined in this study undergoes a structural switch in the presence of adenosine triphosphate (ATP) to release a dabcyl-labeled nucleotide strand (QDNA), which in turn relieves the quenching of a fluorescein label that is also present in the aptamer structure. It was demonstrated that aptamers containing a complementary QDNA strand along with either a short complimentary strand bearing fluorescein (tripartite structure) or a directly bound fluorescein moiety (bipartite structure) remained intact upon entrapment within biocompatible sol-gel derived materials and retained binding activity, structure-switching capabilities, and fluorescence signal generation that was selective and sensitive to ATP concentration. Studies were undertaken to evaluate the properties of the immobilized aptamers that were either in their native state or bound to streptavidin using a terminal biotin group on the aptamer, including response time, accessibility, and leaching. Furthermore, signaling abilities were optimized through evaluation of different QDNA constructs. These studies indicated that the aptamers remained in a state that was similar to solution, with moderate leaching, only minor decreases in accessibility to ATP, and an expected reduction in response time due to diffusional barriers to mass transport of the analyte through the silica matrix. Entrapment of the aptamer also resulted in protection of the DNA against degradation from nucleases, improving the potential for use of the aptamer for in vivo sensing. This work demonstrates that sol-gel-derived materials can be used to successfully immobilize and protect DNA-based biorecognition elements and, in particular, DNA aptamers, opening new possibilities for the development of DNA aptamer-based devices, such as affinity columns, microarrays, and fiber-optic sensors.