A 3D hybrid zinc formate framework, [NH(4)][Zn(HCOO)(3)], possessing an acs topology, shows a high degree of mechanical anisotropy and negative linear compressibility (NLC) along its c axis. High-pressure single-crystal X-ray diffraction studies and density functional theory calculations indicate that contraction of the Zn-O bonds and tilting of the formate ligands with increasing pressure induce changes in structure that result in shrinkage of the a and b axes and the NLC effect along c.
View Article and Find Full Text PDFHybrid inorganic-organic framework materials exhibit unique properties that can be advantageously tuned through choice of the inorganic and organic components and by control of the crystal structure. We present a new hydrothermally prepared 3D hybrid framework, [Mn(2-methylsuccinate)](n) (1), comprising alternating 2D manganese oxide sheets and isolated MnO(6) octahedra, pillared via syn, anti-syn carboxylates. Powder magnetic characterization shows that the compound is a homospin Mn(II) ferrimagnet below 2.
View Article and Find Full Text PDFA 2D homochiral inorganic-organic framework {[Mn(NPTA)(4,4'-bpy)(H(2)O)]·(H(2)O)(2)}(n) was prepared by assembling achiral polar 4-nitrophthalic acid, manganese ions, and ancillary 4,4'-bipyridine ligands (NPTA = 4-nitrophthalate) (4,4'-bpy = 4,4'-bipyridine). The isomorphous Zn(ii) compound was also prepared as a diamagnetic analogue. Adjacent manganese spin centres are linked by the syn-anti carboxylate to form a helical chain, and chains of the same chirality are connected by 4,4'-bpy ligands to generate a homochiral layered framework.
View Article and Find Full Text PDFThe equipment, staffing levels and imaging workload of all 14 radiologist directed nuclear medicine services in district general hospitals in the South Thames Region are presented. These are generally single camera departments providing a broad range of imaging procedures, including cardiac studies and white cell labelling, as well as the more usual renal, lung, thyroid and bone examinations. All departments have a high throughput, averaging 2358 examinations per year.
View Article and Find Full Text PDFData on the equipment available, staffing levels, number and type of procedures carried out in the South Thames Region during 1993-94 and 1996-97 are presented. These are compared with national data for 1993. The number of gamma cameras has increased by 5%, overall staffing by 15% and the number of procedures has increased by 31%.
View Article and Find Full Text PDFA programme of audit, including clinical audit, organizational audit and patient/clinician satisfaction surveys, has been implemented in nuclear medicine departments throughout the South Thames Regional Health Authority (RHA). The clinical topics which have been audited include. ventilation-perfusion lung imaging, bone imaging, liver imaging, thyroid imaging and renal static DMSA imaging.
View Article and Find Full Text PDFHypertension is the most common side-effect of treatment with recombinant human erythropoietin (EPO) for the anemia of chronic renal failure. To elucidate why this occurs in some patients we measured changes in blood volumes and diurnal blood pressure (BP) variation during treatment. Isotope labelled measurements of red cell and plasma volume (RCV and PV) were carried out along with ambulatory BP monitoring before starting EPO and after target hemoglobin (Hb) was reached.
View Article and Find Full Text PDFWe studied 30 patients 6 weeks after first myocardial infarction in order to compare early and delayed imaging after resting injection of thallium for the detection of viable myocardium. Twenty-six of the 30 patients studied had received thrombolysis. Conventional stress and redistribution thallium tomography was followed by a resting injection of thallium with imaging immediately after in all patients and 3 h later in a subgroup of 15 patients.
View Article and Find Full Text PDFThe role of combined alpha and beta blockade as a means of limiting infarct size has been studied in a randomised controlled trial using labetalol. Only 166 of 630 (26%) consecutive patients admitted to a cardiac care unit with suspected myocardial infarction were deemed suitable for inclusion; most of the remainder had delayed admission to hospital, were over the age limit of 75, or had complications which precluded the use of labetalol. Those on active treatment received a loading dose followed by a slow intravenous infusion over six hours, and oral therapy for the subsequent five days.
View Article and Find Full Text PDFThe results of needle aspiration cytology of solid renal lesions in Brighton from 1977 have been reviewed. Thirty-one lesions were aspirated and of the 21 malignant tumours, cytology accurately diagnosed 19 (90%) when sufficient material was sent for analysis. Of the eight avascular solid renal space-occupying lesions aspirated, cytology gave a correct differentiation (benign versus malignant) in seven (87%).
View Article and Find Full Text PDFBr Med J (Clin Res Ed)
September 1981
Twelve patients with acute myocardial infarction and radiological evidence of pulmonary oedema were observed in whom the left atrial pressure, measured indirectly as pulmonary artery end-diastolic pressure, was not critically increased (range 5-12 mm Hg with reference to sternal angle). Eight of the patients had been treated with frusemide, but only six had responded: hence in at least half of the series diuresis could not account for the anomalous finding. Six patients with low cardiac output were given infusions to expand plasma volume.
View Article and Find Full Text PDFScand J Gastroenterol
December 1978
A prospective study of the endoscopic, radiological, and surgical features of chronic duodenal ulceration has been performed. Double contrast barium meal and upper gastrointestinal endoscopy were both performed within five days of elective surgery for chronic duodenal ulceration on 50 patients. The surgical diagnosis correlated with endoscopy in 88% and radiology in 82%, but if both techniques were employed, an accurate pre-operative diagnosis was achieved in 96% of cases.
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