Synthesis and photophysical properties of some conjugated polymers functionalized with ruthenium polypyridine complexes

Symposium J: Electrical, Optical and Magnetic Properties of Organic Solid-State Materials IVA series of conjugated polymers functionalized with different ruthenium polypyridine metal complexes were synthesized by the palladium catalyzed reaction. Two conjugated polymer systems have been studied: 1. poly(phenylenevinylene) with bis(2,2':6',2''-terpyridine) ruthenium (II) on the mainchain and 2. quinoxaline based polymers with tris(2,2'-bipyridine) ruthenium (II). The ruthenium polypyridine complexes exhibit a long-lived metal to ligand charge transfer excited state which can enhance the photosensitivity of the resulting polymers. Different physical properties such as the photoconductivity and charge mobility in these polymers are also studied.published_or_final_versio

Electric vehicle charging at telco base station and bidirectional charging at hillslope descent technical-commercial cost-benefit study and scheduling-reservation system

© 2018 IEEE. Installing grid-connected photovoltaics (GCPV) at telecommunication company (Telco) base stations along highways, and providing electric vehicle (EV) charging facilities at strategic locations such as highway-side base stations offers a synergistic solution to both 1) displacing engine emissions using electricity from a renewable energy source, and 2) providing more highway EV charging stations for long distance EV driving. Strategically placed hillslope EV discharge stations would also offer EV users travelling downhill for long distances to sell their EV battery energy obtained from regenerative braking to the grid, freeing up the needed battery capacity to continue downhill with regenerative braking rather than losing it due to an already fully charged battery. This paper explores potential cost-benefits for investments in (i) highway-side Telco base stations with GCPV systems and EV charging stations as an additional source of revenue, and (ii) investments in EV discharge stations along hillslopes for EV users to sell battery energy from regenerative braking. The methodology used to gauge annual demand of new EV charge stations was by observation of existing highway-side EV charge station usage rates, estimating growth of EVs and charge stations, and reference to existing literature on EV charging tariffs, local electricity costs, and sizing/costing electrical equipment needed for the base station upgrade. To verify discharge kWh calculations from downhill descent regenerative braking, a downhill test drive of a Plug-in Hybrid Electric Vehicle (PHEV) was done. To discourage non-charging EVs remaining parked at charger units, a design framework involving remote charger unit monitoring, reservation, messaging and automated financial incentives is also presented

Light-emitting multifunctional rhenium (I) and ruthenium (II) 2,2′-bipyridyl complexes with bipolar character

A series of multifunctional molecules consisting of hole transport, electron transport, and light-emitting moieties were synthesized and fabricated into single-layer organic light-emitting devices. The light-emitting units were based on 2,2′-bipyridine complexes of rhenium and ruthenium. It was found that, due to the bipolar character of the molecules, the charge carrier mobilities, charge injection barrier, and the device performance were improved. The electron carrier mobilities are on the order of 10-4 cm2V-1 s-1 and a maximum luminescence of 730 cd/m2 was observed. © 1999 American Institute of Physics.published_or_final_versio

Review article: Venous thromboembolism after total joint replacement

published_or_final_versio

Development of metal-containing polymers for optoelectronic applications

Most of the work in organic electroluminescent polymers has been focused on organic conjugated polymers. However, polymers attached with transition metal complex have received relatively less attention. We have synthesized and studied the light emitting properties of some metal containing polymers based on the polypyridine complexes of rhenium and ruthenium. These complexes exhibit long-lived excited states caused by the metal to ligand charge transfer transitions. By varying the structure of the ligand and/or the transition metal, we are able to fine-tune the electronic properties of the resulting metal complexes.We have synthesized a series of poly(phenylenevinylene) (PPV) derivatives which are functionalized with ruthenium polypyridine complexes at the polymer mainchain or side chain. These complexes are able to act as photosensitizers which enhance the photoconductivity of these polymers at longer wavelength. Both the conjugatedbackbone and the metal complex can emit light upon excitation. As a result, it is possible to tune the color by loading different amount of ruthenium complex to the polymer. Luminescence studies showed that the ruthenium complex could quench the emission of the conjugated backbone in some polymers, which suggests an energy transfer processbetween the backbone and the metal complexes. It was also found that the presence of metal complexes could enhance the charge carrier mobilities of the polymers, as the metal and/or ligands can act as extra charge carriers in the charge transport process.published_or_final_versio

Surgical debridement with prostheses retention for the treatment of acute periprosthetic infections following total knee arthroplasty

Free Paper Presentation Session 6 – Adult Joint Reconstruction: no. 6.3INTRODUCTION: Periprosthetic infection after total knee arthroplasty (TKA) is difficult to treat. Surgical debridement with retention of prostheses is one of the valid methods ...postprin

於香港一所大學醫院推行以畸變產物耳聲發射檢查為新生兒進行聽覺普查計劃之可行性

OBJECTIVE: To assess the feasibility of implementing a universal neonatal hearing screening programme using distortion product otoacoustic emission detection at a major teaching hospital in Hong Kong. DESIGN: Descriptive study and questionnaire. SETTING. Teaching hospital, Hong Kong. METHODS: A total of 1064 infants, together with their mothers, were successfully recruited for the study. The participation rate was 99.3%. A three-stage hearing screening protocol using distortion product otoacoustic emission detection was adopted. Each of the participating infants was screened on three separate occasions (day 1-4, day 5-14, and day 21-30 after birth), irrespective of the test results. A questionnaire was administered to 364 randomly selected mothers to determine whether as consumers of the hearing screening service, mothers would find screening desirable. RESULTS: Results of the screening demonstrated an incidence of permanent bilateral hearing loss (>or=40 dB in the better ear) of 0.28%. The results also showed that 3.5% of the screened infants were referred for subsequent diagnostic audiological assessment, including those suspected with unilateral as well as bilateral hearing loss. Data obtained were comparable to other reported results obtained using multi-stage screening protocols. Taking both the false positive rate and the default rate into consideration, the most appropriate time for screening in this hospital setting appeared to be around day 5 to 14 when infants returned to the hospital's day centre as out-patients for routine medical follow-up. Since this day centre service is not generally provided by all maternity hospitals in Hong Kong, an alternative time for screening would be around day 21 to 30 when infants could return as out-patients solely for the hearing test. The results of the questionnaire suggested that most mothers thought a neonatal hearing screening would be desirable (91.35%). The majority (81.70%) indicated a preference for screening either within a few days of birth at the maternity ward prior to discharge from the hospital, or between 5 and 30 days when returning to the hospital as an out-patient. CONCLUSION: It was concluded that a universal neonatal hearing screening programme could be readily implemented in a maternity hospital setting in Hong Kong.published_or_final_versio

Why do Hong Kong patients need total hip arthroplasty? An analysis of 512 hips from 1998 to 2010

published_or_final_versio

Perioperative antithrombotic management in joint replacement surgeries

Objectives To determine optimal perioperative antithrombotic management for patients with cardiac diseases undergoing joint replacement surgeries. Data sources MEDLINE and PubMed database search up to January 2013. Study selection Those dealing with perioperative antithrombotic management of patients undergoing orthopaedic operations, especially joint replacement, and also those undergoing general surgery. Various combinations of the following key words were used in our search: 'antiplatelet', 'antithrombotic', 'anticoagulant', 'coronary stent', 'perioperative', 'venous thromboembolism', 'cardiovascular', 'surgery', 'orthopaedic', 'knee replacement', 'hip replacement', 'joint replacement', and 'arthroplasty'. Data extraction Literature review, original articles, and best practice guidelines. Data synthesis Patients should be stratified according to their risk of developing arterial thromboembolism in order to decide the most appropriate perioperative antiplatelet or anticoagulant regimen for them. After recent coronary stenting, including bare-metal stents implanted within 6 weeks and drug-eluting stents implanted within 6 months, surgery should be deferred. For venous thromboembolism prophylaxis in patients already on aspirin, the dosage should be adjusted as necessary or additional low-molecular-weight heparin administered. Conclusion The perioperative management of patients with cardiac diseases in receipt of antithrombotic agents is based upon a delicate balance between the perceived risk of arterial thromboembolism and the perceived risk of perioperative bleeding. One must exercise good judgement in deciding the most appropriate perioperative antithrombotic regimen. Venous thromboembolism is also a common problem after joint replacement surgeries. For patients already on aspirin, optimal venous thromboembolism prophylaxis is still being debated.published_or_final_versio

Case series of Jehovah's witnesses having Total Knee Arthroplasty in Hong Kong

Electronic Poster Presentations: P48INTRODUCTION: Total knee arthroplasty (TKA) is challenging in Jehovah’s Witnesses (JW), as they do not accept transfusions. We report our experiences with a series of TKAs in JW in our ...postprin