Molecular engineering of liquid crystalline polymers by living polymerization

Summary This paper describes the synthesis and characterization of poly{3-[4-cyano-4-biphenyl)oxy]propyl vinyl ether} [poly(6-3)] macromonomers obtained by the functionalization of the growing chain end of the corresponding living polymer obtained by the initiation of the cationic polymerization of 3-[4-cyano-4-biphenyl)oxy]propyl vinyl ether with CF₃SO₃H/S(CH₃)₂, with 2-hydroxy ethyl methacrylate [poly(6-3)-I], 2-[2-(2-allyloxyethoxy)ethoxy]ethanol [poly(6-3)-II] and 10-undecen-1-ol [poly(6-3)-III].Part 20: V. Percec and M. Lee, J. Mater. Chem., submitted     

Multi-field 3D scanning light microscopy of early embryogenesis

A computer‐controlled microscopy system was devised to allow the observation of avian embryo development over an extended time period. Parallel experiments, as well as extended specimen volumes, can be recorded at cellular resolution using a three‐dimensional scanning procedure. The resulting large set of data is processed automatically into registered, focal‐ and positional‐drift corrected mosaic images, assembled as montages of adjacent microscopic fields. The configuration of the incubator and a sterile embryo chamber prevents condensation of the humidified culturing atmosphere in the optical path and is compatible with both differential interference contrast and epifluorescence optics. As a demonstration, recordings are presented showing the large‐scale remodelling of the embryonic primordial vascular structure.     

Developmental patterns of expected consequences for simulated bicycle injury events

Three patients with shunt malfunction, who had previously undergone a shunting procedure for noncommunicating hydrocephalus of adolescent and adult onset, successfully underwent a percutaneous flexible neuroendoscopic ventriculostomy. This procedure was performed as an alternative treatment for shunt revision by the use of our newly developed flexible fiberoptic ventriculoscope. All patients were able to remain independent of the shunt system after the ventriculostomy. These results thus suggest that a percutaneous flexible neuroendoscopic ventriculostomy can be effective for the treatment of shunt-dependent patients with shunt malfunction in adolescents and adults.     

Multimedia synchronization protocols for broadband integratedservices

Protocols to provide synchronization of data elements with arbitrary temporal relationships of both stream and non-stream broadband traffic types are proposed. It is specified that the provision of a synchronization function be performed within a packet switched network, and, accordingly, a two-level communication architecture is presented. The lower level, called the network synchronization protocol (NSP), provides the ability to establish and maintain individual connections with specified synchronization characteristics. The upper level, the application synchronization protocol (ASP), supports an integrated synchronization service for multimedia applications. The ASP identifies the temporal relationships among an application's data objects and manages the synchronization of arriving data for playout. The proposed NSP and ASP are mapped to the session and application layers of the open-systems-interconnection (OSI) reference model, respectively     

Care: from theory to orientation and back

In this paper, I urge that the very real lessons Carol Gilligan's work in moral psychology offer to moral philosophy can best be appreciated if we take seriously the gap between the two disciplines. The care and justice perspectives Gilligan explores are psychological orientations, and orientations are defined as much by matters of emphasis, selectivity of interpretation, and gestalt as they are by propositional commitment. As such, I argue, their contribution to moral theory is best seen as stances from which to do theory, rather than as constituting ready-made theories themselves. In pursuing this train of thought, I examine how Gilligan's work has developed over time and how, in the end, we should understand the juxtaposition between the two orientations.     

Nurse triage for house call requests in a Tyneside general practice: patients' views and effect on doctor workload

BACKGROUND: Demand for consultations in primary care has risen recently, necessitating a change in working practices. As part of this process, the possible contribution of practice nurses in the telephone assessment of home visit requests merits attention. AIMS: To survey the views of our patients encountering our nurse triage system for home visit requests, set up in June 1995, and to plot its effect on the routine visiting workload of our doctors and thus their availability at the surgery. METHOD: The outcome of each request was categorized as: doctor to visit (DV), surgery consultation with doctor (SC), nurse advice given and accepted (NA), or call passed to doctor for advice (DA). Frequency data from September 1995 to December 1996 were recovered. Questionnaires for self-completion were sent to all those requesting a routine weekday house call during two four-week periods in 1995 and 1996. RESULTS: Analysable activity data revealed 1764 house call requests, with 41% DV, 18% SC, 24% NA, and 8% DA. In the first survey, 121 questionnaires were sent out and 84 returned (69% response rate) and, in the second, the corresponding figures were 113, 85, and 75%. About 80% of responders reported that they were satisfied with the help received from the nurse. CONCLUSIONS: Nurse triage of house call requests has led to more efficient care for our patients, as we have increased the availability of surgery consultations by reducing the number of house calls made by our general practitioners.     

Combined nicotinic and muscarinic blockade in elderly normal volunteers: cognitive, behavioral, and physiologic responses

1-, 3-, and 6-nitrobenzo[a]pyrene (nitro-BaP) are environmental contaminants that can be metabolized to genotoxic derivatives by either nitroreduction or ring-oxidation. In this study, we examined the types of mutations produced by the primary nitroreduced metabolites, 1-, 3-, and 6-nitroso-BaP (NO-BaP) in the hprt gene of Chinese hamster ovary cells. RNA from 6-thioguanine-resistant mutants was reverse-transcribed to cDNA and the hprt coding sequence was amplified and sequenced. The mutational patterns produced by the three compounds exhibited extensive similarities: 1) base pair substitutions accounted for 67% (28/42) of 1-NO-BaP, 51% (26/51) of 3-NO-BaP, and 50% (11/22) of 6-NO-BaP mutations; 19-36% of the mutations were exon deletions and 14-18% were frameshifts; 2) most (64-84%) of the simple base pair substitutions occurred at G:C, mainly G:C-->T:A and G:C-->C:G transversions; 3) 98% (46/47) of the simple base pair substitutions at G:C had the mutated dG on the non-transcribed strand and 81% (38/47) were located with the mutated dG flanked 3' by at least one purine; and 4) most simple base pair substitutions (48/62, 77%) occurred in exons 2, 3, and 8 of the hprt gene. Although there were no significant differences among the mutation profiles of the NO-BaPs, a significant difference did exist between the mutation pattern produced by 3-NO-BaP and the mutation pattern previously determined for the ring-oxidized product of 3-nitro-BaP metabolism, trans-7,8-dihydroxy-anti-9,10-epoxy-7,8,9, 10-tetrahydro-3-nitrobenzo[a]pyrene. This observation indicates that differences in the structures of closely related adducts can be important enough to have an effect on mutation profiles.