Supramolecular assembly of platinum-containing polyhedral oligomeric silsesquioxanes: an interplay of intermolecular interactions and a correlation between structural modifications and morphological transformations

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EL2 deep donor state in semi-insulating GaAs revealed by frequency dependent positron mobility measurements

Positron mobility measurements carried out on semi-insulating GaAs, using the Doppler shift in annihilation radiation technique, show a sharp transition from a high mobility value ∼120 cm2 V-1 s-1 to a lower value ∼45 V-1 s-1 just below room temperature. The temperature of the transition is found to be dependent on the frequency of the applied AC bias. We show that this effect is an artifact due to the thermal ionization of the EL2 deep donor state, which in its ionized state forms a positive space charge that causes the positron to experience large electric fields. This observation suggests a new positron annihilation-based deep-level transient technique applicable to semi-insulating materials. © 1994 The American Physical Society.published_or_final_versio

Active site of praseodymium orthovanadate catalyst in oxidative dehydrogenation of propane

The pure phase of praseodymium orthovanadate (PrVO4) has been prepared by the citrate method. The active sire of PrVO4 was studied by ESR, NO-TPD, O-2-TPD and O-18(2)-isotope exchange methods. The results of ESR and NO-TPD confirmed the presence of V4+ in the catalyst. O-18(2)-isotope exchange was through a single exchange procedure. From the result of O-2 + TPD and the kinetic study of O-18(2)-isotope exchange, one can reach a conclusion that the V4+ species associated with oxygen vacancies are the site for O-2 activation. The adsorbed O-2 or O- are the active oxygen species in propane oxidative dehydrogenation

Transformable Nanostructures of Luminescent Platinum-Containing Organosilane Hybrids: Non-Covalent Self- Assembly of Polyhedral Oligomeric Silsesquioxanes Assisted by Pt···Pt and π–π Stacking Interactions of Alkynylplatinum(II) Terpyridine Moieties

Poster Presentation: S9- Supramolecular Chemistry and Self-Assembly - no. S9.P

The active sites of the reference phase of SmVO4 as catalyst for propane oxidative dehydrogenation

The active sites of samarium orthovanadate (SmVO4) were studied by means of ESR, NO-TPD and temperature programmed O-18(2)-isotope exchange (TPIE) methods. The results of ESR and NO-TPD confirm the presence of V4+ in the catalyst. The TPIE revealed that the O-18(2)-isotope exchange was carried out through a single exchange procedure. The V4+ species associated with oxygen vacancies are the sites for O-2 activation

A synopsis of current haemophilia care in Hong Kong

Objective To provide a synopsis of current haemophilia care in Hong Kong. Design Retrospective survey. Setting All haematology units of the Hospital Authority in Hong Kong. Patients All patients with haemophilia A and haemophilia B. Results To date, there were 222 mild-to-severe haemophilia patients (192 type A, 30 type B) under regular public care in Hong Kong (43% were considered severe, 33% moderate, and 24% mild), which gave a crude prevalence of 6.8/100 000 male inhabitants. A total of 12.8 million units of Factor VIII and 3 million units of Factor IX were prescribed annually. This amounts to 1.83 units of FVIII per capita of the population, which is comparable to that of other developed countries. Leading causes of mortality were human immunodefciency virus-related complications (10 cases) and cerebral bleeding (2 cases). The life expectancy of patients with severe haemophilia in Hong Kong is improving; currently the oldest patient is 60 years old. Such improved survival may be due to enhanced factor availability, prompt treatment of bleeding episodes at home, safer factor products, and better antiviral treatment. Primary prophylaxis is the accepted standard of care for severe and moderate cases, and "Factor First" has become hospital policy. However, 12 patients continue to present treatment challenges, due to the documented presence of factor inhibitors. In all, 28,100, and 14 cases respectively were positive for human immunodefciency virus, hepatitis C virus, and hepatitis B virus; the youngest patients with the corresponding infections being 28,13, and 22 years old. Comprehensive care with dedicated physiotherapy, surgical support, and radionucleotide synovectomy may reduce morbidity further. Conclusion A multidisciplinary approach can further improve the future care for haemophilia patients in Hong Kong.published_or_final_versio

A synopsis of current care of thalassaemia major patients in Hong Kong

OBJECTIVE: To provide a synopsis of current thalassaemia major patient care in Hong Kong. DESIGN: Retrospective study. SETTING: All haematology units of the Hospital Authority in Hong Kong. PATIENTS: All patients with thalassaemia major with regular transfusion. RESULTS: To date, there were 363 thalassaemia major patients under the care of the Hospital Authority. Prenatal diagnosis has helped to reduce the number of indigenous new cases, but in recent years immigrant cases are appearing. The patients have a mean age of 23 (range, 1-52) years, and 78% of them are adults. In 2009, they received 18 782 units of blood. This accounted for 9.5% of all blood consumption from the Hong Kong Red Cross. In the past, cardiac iron overload was the major cause of death (65%) and few patients survived beyond the age of 45 years. The availability of cardiac iron assessment by magnetic resonance imaging (T2 MRI) to direct the use of oral deferiprone chelation has reduced the prevalence of heart failure and cardiac haemosiderosis, which should reduce mortality and improve life expectancy. CONCLUSION: The future for thalassaemia care in Hong Kong is bright. With better transfusion and chelation, it should be possible to avoid growth and endocrine deficiencies in younger patients.published_or_final_versio

In vitro synergistic cytoreductive effects of zoledronic acid and radiation on breast cancer cells

INTRODUCTION: Bisphosphonates are mostly used in the treatment of bone metastases. They have been shown to act synergistically with other chemotherapeutic agents. It is not known, however, whether similar synergistic effects exist with radiation on breast cancer cells. METHODS: Human MCF-7 breast cancer cells were treated with up to 100 μM zoledronic acid, were irradiated with up to 800 cGy or were exposed to combinations of both treatments to determine the antiproliferative effects of zoledronic acid and radiation. RESULTS: Zoledronic acid and radiation caused a dose-dependent and time-dependent decrease in cell viability (approximate 50% growth inhibition values were 48 μM and 20 μM for 24 hours and 72 hours, respectively, for zoledronic acid and 500 cGy for radiation). A synergistic cytotoxic effect of the combination of zoledronic acid and radiation was confirmed by isobologram analysis. CONCLUSION: These data constitute the first in vitro evidence for synergistic effects between zoledronic acid and radiation. This combination therapy might thus be expected to be more effective than either treatment alone in patients with metastatic breast carcinoma

Cross-sectional survey of a sample of UK primary care dental professionals' experiences of sharps injuries and perception of access to occupational health support

Background: The 2013 Sharps Regulations were introduced to minimise the risk of sharps injuries and blood borne virus transmission throughout healthcare. Occupational health (OH) services are pivotal for helping employers implement these regulations. Despite this, no research has been conducted on the prevalence of sharps injuries, underreporting of injuries or access to OH among primary care dental professionals in the UK since 2013. Aim: To estimate the prevalence of sharps injuries, the level of underreporting and of self-reported access to an OH service both for the care of sharps injuries and for general health and wellbeing. Method: A cross-sectional survey was administered at the 2017 British Dental Association (BDA) Conference and Exhibition in Manchester, and at the 2017 BDA Scottish Conference and Exhibition in Glasgow. The survey covered questions relating to sharps injuries and OH support. Statistical analyses were conducted using SPSS Version 22 (IBM Corp., 2013). Results: A total of 796 delegates participated, of whom 166 (20.8%) had experienced a sharps injury in the past year and 58 (35%) did not report the incident. Of the participants, 190 (23.9%) reported no, or uncertain, access to OH support. Most respondents' practices had a sharps safety policy (771; 96.9%), but fewer (611; 76.8%) had received training on the prevention of sharps injuries and neither policy nor training were associated with incident reporting. Conclusion: Despite the introduction of the sharps regulations, sharps injuries and underreporting of injuries remain prevalent among those practising in primary dental care. Our results also suggest that there are significant shortfalls in OH support, at a time when changes to guidance on health clearance and management of BBV infected healthcare workers, in addition to sharps injury management, increase the need for such services