Work function measurements using a field emission retarding potential technique.

Herein we describe the measurement of the work function of a metal with advanced equipment based on the field emission retarding potential (FERP) method using a carbon nanotube (CNT) as cathode. The accuracy of the FERP method using a CNT emitter is described and a comparison between measurements of the work functions of aluminum, barium, calcium, gold, and platinum with published data will be presented. Our FERP equipment could be optimized with the aid of particle tracing simulations. These simulations led us to insert a magnetic collimator to improve the collection efficiency at the anode.

Field emission from hybrid diamond-like carbon and carbon nanotube composite structures.

A thin diamond-like carbon (DLC) film was deposited onto a densely packed "forest" of vertically aligned multiwalled carbon nanotubes (VACNT). DLC deposition caused the tips of the CNTs to clump together to form a microstructured surface. Field-emission tests of this new composite material show the typical low threshold voltages for carbon nanotube structures (2 V µm(-1)) but with greatly increased emission current, better stability, and longer lifetime.

A case of manganese induced parkinsonism in hereditary haemorrhagic telangiectasia.

A 44 year old right handed woman complained of difficulty in moving. She and her relatives had skin telangiectasia or recurrent epistaxis. On neurological examination, she had a mask-like facies and bradykinesia in both extremities. Laboratory examinations showed iron deficiency anaemia and mild liver dysfunction with raised serum manganese. On T1 weighted cranial magnetic resonance imaging there were hyperintense areas in the globus pallidus bilaterally, suggesting manganese deposition. Abdominal angiography confirmed multiple portal-systemic shunts in the liver, and a needle biopsy of the liver showed diffuse dilatation of the sinusoids with fatty change. Levodopa did not improve the bradykinesia. This appears to be a case of hereditary haemorrhagic telangiectasia with manganese induced parkinsonism, which may be a new type of neurological disorder in such patients.

New bisdesmosidic triterpene saponins from the roots of Pulsatilla chinensis.

Further phytochemical analysis aimed at the triterpene saponin constituents of the roots of Pulsatilla chinensis has resulted in the isolation of four new bisdesmosidic triterpene saponins whose aglycons are based on the lupane skeleton (1-4), together with three known saponins (5-7). The structures of the new compounds were determined by spectroscopic analysis and acid-catalyzed hydrolysis.

[A case of hypertrophic obstructive cardiomyopathy with left atrial giant thrombus during anti-platelet therapy].

A case of a 77-year-old female with hypertrophic obstructive cardiomyopathy having the left atrial "giant" thrombus was reported; the diagnosis of the localization and size of the thrombus was made by employing echocardiography and contrast enhancement computed tomography as well. The clinical record indicated that the thrombus formation, which happened in the course of the antiplatelet therapy, was to be considered due to the complicated condition of the patient, i.e., the combination of atrial fibrillation, low cardiac output, enlargement of left atrium and left ventricular diastolic disfunction, which assumed to predispose the giant thrombus. Avoiding the surgical removal of the thrombus because of the poor conditions of the patient, urokinase treatment was attempted, but not successful, which might be derived from the nature of the thrombus already organized. In general, left atrial giant thrombus is very uncommon status; if any, it is occasionally complicated with mitral stenosis. The case reported deems to be very rare, enough worthy to be reported.