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In an effort to answer many unresolved questions concerning orthotopic homotransplantation of the canine liver, a complete reappraisal of this preparation was under-taken in early 1964 in both the untreated and modified host. A particular effort was made to (A) reduce the operative mortality; (B) interpret the significance of pathologic changes in the homograft and in the recipient tissues; (C) define the presence or absence of a graft-host reaction; (D) study the effect of variations in therapy upon results; (E) assess the hepatotoxic properties of azathioprine; (F) determine if and with what regularity hepatic rejection could be reversed and chronic survival attained; and (G) find if and when a state of relative host-graft non-reactivity developed some time after homotransplantation. METHODS Mongrel dogs weighing 8.3 to 27.3 kilograms were used. All animals had hematologic and liver function determinations before and at regular intervals after the experiments were begun. Red cell survival studies were performed with a Cr 51 technique. 6 Tetracycline and chloramphenicol were routinely administered. Azathioprine * was employed in most experiments with a dose of 2 to 8 mg. per kilogram per day. Insofar as possible, the induction of leukopenia was avoided. Azathioprine and antibiotic therapy was discontinued at 120 days in all surviving animals. Other variations in therapy are described below. Tissues were examined with light and electron microscopy. For homotransplantation, livers were obtained from donors of dissimilar appearance, but of approximately the same weight as the recipients. Prior to removal, the donor liver was cooled by perfusion of chilled Ringer's lactate solution through the portal vein. The technique of transplantation 24 resulted in an essentially normal blood supply (Fig. 1). The intervals of ischemia were almost all less than one hour. Cholecystoduodenostomy was established for internal biliary drainage. Azathioprine toxicity study In 18 non-transplanted dogs the effects of 40 days of azathioprine were studied. The animals were divided into 3 groups of 6 each which received: Group I. Daily azathioprine (2 to 4 mg. per kilogram).

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Abstract:For the last three decades, a large scale integration of distributed generation (DG) is beginning to change the electrical distribution network from passive to active. Consequently, technical difficulties are created by significant impacts generated by DGs with voltage variation being the dominant effect. This paper presents a comprehensive review of voltage control techniques on electrical distribution networks connected with DG, recommendations are provided in terms of enhancing network voltage stability and maximising the DG utilisation.

Currently the operators of electrical distribution networks face a number of challenges, such as load growth, the proliferation of distributed generation and ageing infrastructure. This is drawing attention to techniques which will allow more efficient asset utilisation and carefully selected reinforcement projects. This paper presents the findings of research into the technical challenges and potential benefits of dynamic thermal rating (DTR) systems. The adoption of DTR systems has the potential to improve network capacity and in some cases to offer an effective alternative to traditional reinforcement methods. The research presented in this paper suggests that, when compared to traditional solutions of network reinforcement, a DTR system can, in some cases, offer a less invasive and more cost effective solution which allows the DNO to realise improved network component utilisation.