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951.
Riaan Büchner Raymond J. Haines Robert McGuire Jr. Orde Q. Munro 《Inorganica chimica acta》2007,360(5):1633-1638
The synthesis and characterisation of an orange polymorph of [Pt(trpy)(CCPh)]SbF6 is described where trpy = 2,2′:6′,2″-terpyridine. An X-ray crystal structure determination at 293 K reveals that the cations are planar and stacked head-to-tail with alternating Pt?Pt distances of 3.604(1) and 4.412(1) Å. The perpendicular distances between successive cation planes are constant along the stack at a value of 3.33 Å. Crystal structure determinations at 240 and 200 K show that reducing the temperature to 200 K has no significant effect on the cation arrangement. However, below 200 K there is a phase change that we have not been able to characterise, but which has an effect on the solid state photoluminescence exhibited by [Pt(trpy)(CCPh)]SbF6. Thus, whereas at temperatures of ?200 K, a broad peak with two components at ca. 566 and 597 nm is observed, below 200 K a longer wavelength peak develops that red-shifts as the temperature is lowered [λ(em)max = 637 nm at 80 K]. We assign the ?200 K emission as 3MLLCT in origin, since the X-ray data show that ligand-ligand (LL) and not metal-metal (MM) interactions are important at T ? 200 K. On the other hand, the long wavelength emission observed below 200 K is typical of 3MMLCT emission, suggesting that the phase change leads to dz2(Pt)-dz2(Pt) orbital interactions. Of particular interest is that the cation exhibits 3MLCT emission in dichloromethane that maximizes at 619 nm, i.e., the high temperature solid state emission occurs at a shorter wavelength, an unexpected result since intermolecular interactions in the solid usually cause the emission to occur at longer wavelengths. A possible explanation for this unexpected result is given. 相似文献
952.
P B Jacklin J A Roberts P Wallace A Haines R Harrison J A Barber S G Thompson L Lewis R Currell S Parker P Wainwright the Virtual Outreach Project Group 《BMJ (Clinical research ed.)》2003,327(7406):84
Objectives To test the hypotheses that, compared with conventional
outpatient consultations, joint teleconsultation (virtual outreach) would
incur no increased costs to the NHS, reduce costs to patients, and reduce
absences from work by patients and their carers.Design Cost consequences study alongside randomised controlled
trial.Setting Two hospitals in London and Shrewsbury and 29 general
practices in inner London and Wales.Participants 3170 patients identified; 2094 eligible for inclusion
and willing to participate. 1051 randomised to virtual outreach and 1043 to
standard outpatient appointments.Main outcome measures NHS costs, patient costs, health status
(SF-12), time spent attending index consultation, patient satisfaction.Results Overall six months costs were greater for the virtual
outreach consultations (£724 per patient) than for conventional
outpatient appointments (£625): difference in means £99 ($162;
€138) (95% confidence interval £10 to £187, P=0.03). If the
analysis is restricted to resource items deemed “attributable” to
the index consultation, six month costs were still greater for virtual
outreach: difference in means £108 (£73 to £142, P <
0.0001). In both analyses the index consultation accounted for the excess
cost. Savings to patients in terms of costs and time occurred in both centres:
difference in mean total patient cost £8 (£5 to £10, P <
0.0001). Loss of productive time was less in the virtual outreach group:
difference in mean cost £11 (£10 to £12, P < 0.0001).Conclusion The main hypothesis that virtual outreach would be cost
neutral is rejected, but the hypotheses that costs to patients and losses in
productivity would be lower are supported. 相似文献
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954.
Considerable literature exists on the benefits of breast feeding on the health and survival of infants and young children, but there is less on the effects on later life outcomes. One such measure of health and well-being that has received attention in the historical literature is terminal adult stature. Information on height is rather widely available; however, it is much more difficult to obtain data on breast feeding. One country that does have such information is Imperial Germany (1871-1919). A number of physicians and local health officials collected information on the incidence and duration of breast feeding early in the 20th century, particularly because of concern about the unusually high infant mortality rates in parts of Germany. Hallie Kintner has surveyed the published results of these studies. The information on the prevalence of breast feeding for the period 1903/10 has been inputed into a database of demographic and economic variables for the counties (Regierungsbezirke) of Germany (1850-1939). There are also published data on heights of military recruits from the Imperial German military forces in 1906. These can be linked to areas in the database and related to breast feeding practices and infant mortality both contemporaneously and approximately 20 years previous to 1906. Results indicate a significant effect of infant feeding practices on later life outcomes operating through infant health conditions, proxied by the infant mortality rate. 相似文献
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958.
Primate locomotor patterns are the result of osteological and myological interactions, the effectiveness of which is governed by various afferent, internuncial and efferent central nervous system pathways. The distribution of primary afferents following lumbosacral ganglionectomies and the distribution of corticospinal fibers following lesion of contralateral motor cortex to medial and lateral ventral horn motor nuclei have been discussed for the tree shrew and bushbaby. Based on limited data it has been suggested that the tree shrew is the best living example of the quadrupedal Paleocene forms from which primates presumably evolved, and the bushbaby is one of the best examples of the vertical clingers and leapers which appeared in the Eocene. Both forms have dense primary afferent distribution to cells of the lateral portion of the ventral horn, which are related to appendicular musculature, and sparse projection to the medial part of the ventral horn which innervates axial musculature. Corticospinal fibers in the tree shrew do not synapse in any portion of the ventral horn at any spinal cord level. The bushbaby has direct cortical motor control over cells located in the medial portion of the ventral horn and, consequently, over axial musculature. Extrapolations from studies on the tree shrew and other generalized forms suggested that Paleocene quadrupeds lacked cortical control over axial and appendicular musculature and depended primarily on subcorticospinal pathways and spinal reflexes for the execution of their locomotor pattern. Eocene vertical clingers and leapers retained the reflex pathways of their Paleocene ancestors but acquired direct cortical motor control over axial musculature, thus indicating a first level of neuroanatomical adaptation related to evolving locomotor styles. It was suggested that there are correlations between locomotor style and neuromorphological specializations, and that comparative observations on key extant phylogenetic forms may provide a clearer and more complete picture of initial locomotor adaptations in the primate series. 相似文献
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960.