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AbstractBesides the well-known positive impacts of public sector-led urban redevelopment projects on housing prices in their vicinity, we found that there were less noticeable negative impacts on the prices of very new and old housing units nearby, especially in high density urban areas where housing is mainly in the form of multiple-owned high-rise apartment units. First, the prices of older housing units declined faster after the announcement of a nearby public sector-led development. We explain this by decomposing the value of the property into existing use value and real redevelopment option value. The latter component was significantly reduced by a nearby public sector-led redevelopment. Second, for the very new nearby housing units, their prices also declined when there was nearby redevelopment due to an expected increase in the supply of new housing units. Based on second-hand housing transaction records in the vicinity of public sector-led redevelopment projects over a 12-year period, we were able to isolate the above negative impacts from other external effects. The empirical results support the existence of both negative impacts of public sector-led urban redevelopment projects.

Highly efficient orange and green emission from single‐layered solid‐state light‐emitting electrochemical cells based on cationic transition‐metal complexes [Ir(ppy)2sb]PF6and [Ir(dFppy)2sb]PF6(where ppy is 2‐phenylpyridine, dFppy is 2‐(2,4‐difluorophenyl)pyridine, and sb is 4,5‐diaza‐9,9′‐spirobifluorene) is reported. Photoluminescence measurements show highly retained quantum yields for [Ir(ppy)2sb]PF6and [Ir(dFppy)2sb]PF6in neat films (compared with quantum yields of these complexes dispersed in m‐bis(N‐carbazolyl)benzene films). The spiroconfigured sb ligands effectively enhance the steric hindrance of the complexes and reduce the self‐quenching effect. The devices that use single‐layered neat films of [Ir(ppy)2sb]PF6and [Ir(dFppy)2sb]PF6achieve high peak external quantum efficiencies and power efficiencies of 7.1 % and 22.6 lm W–1) at 2.5 V, and 7.1 % and 26.2 lm W–1at 2.8 V, respectively. These efficiencies are among the highest reported for solid‐state light‐emitting electrochemical cells, and indicate that cationic transition‐metal complexes containing ligands with good steric hindrance are excellent candidates for highly efficient solid‐state electrochemical cells.

A novel host material for efficient green and red electrophosphorescence devices is obtained by adopting the new molecular strategy of nonconjugated linkage of carbazole and fluorene moieties. The new host combines characteristics of both carbazole and fluorene, giving a large-gap host material suitable for green and red phosphorescent OLEDs. Green and red phosphoresecent OLEDs with external quantum efficiencies up to 10% have been achieved with this new host material.

Remarkable UV OLED devices using novel spiro-configured bifluorenes as UV emitters have been successfully achieved with external quantum efficiencies up to 2.6−3.1% and emission wavelengths as short as 370 nm. In addition, these large-gap materials have been shown to be effective hosts for red phosphorescent emitters in phosphorescent OLEDs. This result represents the first example that pure hydrocarbon molecules can serve as an efficient host for red electrophosphorescence devices.

A more efficient OLED device with blue emission characteristic of terfluorene has been achieved by using a novel molecular doping strategy, in which 4,5-diazafluorene was incorporated as the substitution group of terfluorene to facilitate electron injection from the metal cathode yet without altering emission characteristics.

Recent developments in gene therapy using adenoviral (Ad) vectors have fueled renewed interest in the 293 human embryonic kidney cell line traditionally used to produce these vectors. Low-glutamine fed-batch cultures of serum-free, suspension cells in a 5-L bioreactor were conducted. Our aim was to tighten the control on glutamine metabolism and hence reduce ammonia and lactate accumulation. Online direct measurement of glutamine was effected via a continuous cell-exclusion system that allows for aseptic, cell-free sampling of the culture broth. A feedback control algorithm was used to maintain the glutamine concentration at a level as low as 0.1 mM with a concentrated glucose-free feed medium. This was tested in two media:  a commercial formulation (SFM II) and a chemically defined DMEM/F12 formulation. The fed-batch and batch cultures were started at the same glucose concentration, and it was not controlled at any point in the fed-batch cultures. In all cases, fed-batch cultures with double the cell density and extended viable culture time compared to the batch cultures were achieved. An infection study on the high density fed-batch culture using adenovirus-green fluorescent protein (Ad-GFP) construct was also done to ascertain the production capacity of the culture. Virus titers from the infected fed-batch culture showed that there is an approximately 10-fold improvement over a batch infection culture. The results have shown that the control of glutamine at low levels in cultures is sufficient to yield significant improvements in both cell densities and viral production. The applicability of this fed-batch system to cultures in different media and also infected cultures suggests its potential for application to generic mammalian cell cultures.

A series of novel 9,9-diarylfluorene-capped oligothiophenes were synthesized by Suzuki coupling reactions in good yields. The color of the emissions can be controlled by varying the conjugation length of the oligothiophene core. The bulky and rigid terminal groups of the resulting oligomers are significantly beneficial for their high morphological and thermal stability. These new oligothiophenes exhibit intriguing reversible oxidation and reduction redox behavior.

Conjugated oligomers with an alternating phenylene−pyrimidine structure have been synthesized by the successive Suzuki coupling reaction starting from 2-bromo-5-iodopyrimidine. The photoluminescence properties and quasi-reversible redox behavior of these oligomers make them applicable as an active material for a light-emitting device. Blue light-emitting electroluminescent devices with an external quantum efficiency up to 1.8% have been fabricated.

9,9-Diaryl-2,7-dibromofluorene was synthesized by a triflic acid promoted Friedel−Crafts reaction. Introduction of diarylamino groups at its C2 and C7 positions by a Pd-catalyzed amination results in the formation of a novel class of triaryldiamines. The 9,9-diaryl substituents at the central linkage play a less important role in the photophyscial properties but affect the oxidation potential and improve the morphological stability of these new triarylamines.

5,6-Dihydroxyindole (1a) was isolated by bioactivity-directed fractionation from fresh leaves of Rhaphidophora korthalsii. The unstable compound and its stable diacetate (1b) were characterized spectroscopically and confirmed by synthesis. The ED50 of 1a against P388 cells was 3.5 μg/ml.

The records of 71 consecutive patients who underwent percutaneous nephrostomy for malignant ureteral obstruction were reviewed. The average post-nephrostomy survival time was seven months, of which 25% was spent in the hospital. When comparing these figures to older studies of open nephrostomy, the percutaneous procedure is associated with less morbidity and an increased percentage of time spent at home (75% compared to 36%). Long-term survival, however, is still poor, with only 25% of patients alive at one year. We suggest that the criteria previously adopted for open nephrostomy generally remain appropriate for patients being considered for percutaneous urinary diversion.

The kinetics of the acetone-sensitized photoaddition of HBr to ethylene are consistent with the free radical chain mechanism of Vaughan, Rust, and Evans. In the presence of excess propane the combination of bromine atoms (reaction [4]) is the main termination step, and bromoethyl radicals formed by the addition of bromine atoms to ethylene (reaction [2]) are collisionally stabilized. They undergo thermal decomposition (reaction [−2]) or abstract a hydrogen atom from hydrogen bromide (reaction [3a]) to form the product, ethyl bromide. The rate constant ratio, k−2/k3a, increases from 5.6 × 1018molecules cm−3at 15.3 °C to 11.5 × 1018molecules cm−3at 45.0 °C. This corresponds to E−2 − E3a = 4.5 ± 0.5 kcal mole−1, and is in accord with the thermochemical data. Within experimental error, k2and k−2are independent of propane pressure in the range 260 to 390 Torr. Also, is equal to 5.5 ± 0.3 × 108 cm3/2molecule−1/2s−1/2, independent of temperature over the range 15.3 to 45.0 °C, and E2 = 0.0 ± 0.5 kcal mole−1. In the absence of propane, and at ethylene pressures in excess of 400 Torr, the combination and disproportionation of bromoethyl radicals is the main termination process (reaction [7]). The value of is 8.9 ± 0.1 × 10−10 cm3/2molecule−1/2s−1/2at 35.1 °C, in agreement with kinetic data for related reactions.

The rate of combination of bromine atoms in the photosensitized hydrobromination of ethylene has been determined by the rotating sector technique. From this and kinetic data reported previously the rate constant for the addition of bromine atoms to ethylene in the presence of 380 Torr of propane as deactivating gas has been calculated to be 1.5 ± 0.3 × 10−14 cm3molecule−1s−1, independent of temperature in the range 15 to 35 °C. This result is discussed and compared with rate constants for other addition reactions to ethylene.

The assays for antibodies to rubella virus are time consuming and complicated by the lack of simple and accurate indicator systems. The recent development of rubella CF antigen in RK-13 and AGMK cells(2) as well as in BHK-21 cells (1) made it possible to measure complement fixing antibodies quickly and accurately in a well standardized system(7). However, whereas RK-13 and AGMK cells had to be concentrated over 200-fold (30% cell suspension) to yield antigen titers of 1/8(2), BHK-21 cells required only 20-fold concentration (3-4% cell suspension) to produce similar titers without anticomplementary complications.The production procedure described here resulted in improved antigen yields of consistently high titers sufficient to carry out reproducible, highly satisfactory tests for complement fixing antibodies to rubella, Peak antigen titers were preceded by the appearance of cytopathic effect and acidification of the maintenance medium. The antigen produced by this procedure reduced the costs of production sufficiently to make the complement fixation test a diagnostic tool feasible for use in epidemiological studies of rubella infections and for evaluation of immunogenic properties of future rubella vaccines.

Four thieno[3,2-b]thiophene (TT)-based donor-π-acceptor–type small-molecule donors DTCPTT, DTCPTT-2CN, DTDCPTT, and DTDCPTT-2CN were synthesized and characterized. A clear structure-property relationship correlating the effects of introducing cyano groups onto the TT and the end-capping groups has been successfully established. DTDCPTT and DTDCPTT-2CN were adopted as electron donors for organic photovoltaics (OPVs) mainly due to the strong intramolecular charge transfer absorption in the visible light region, sufficiently high thermal stability, and appropriate energy level alignment with C70. Moreover, the analyses of crystal structures reveal that DTDCPTT and DTDCPTT-2CN form antiparallel dimer pairs through strong dipolar and non-covalent intermolecular interactions. X-ray structures also indicate that introducing cyano groups onto the TT moiety does not affect the backbone planarity significantly. Compared with DTDCPTT-2CN, the more compact and uniform crystal packing renders DTDCPTT advantageous for exciton dissociation and charge carrier transport. DTDCPTT-based device achieves power conversion efficiency as high as 7.81% and 16.89%, respectively, under simulated AM 1.5G illumination and 500 lux TLD-840 fluorescent lamp illumination, which could be attributed to stronger absorption and better photocurrent extraction. In addition, both devices exhibit high stability under continuous simulated 1 sun illumination for more than 300 h. As far as we know, this is the best performance for vacuum-processed small-molecule indoor OPVs to date.

Linear molecules with different arrangement of dipolar pyrimidine moieties in the π-conjugated backbone were synthesized by a Pd-catalyzed Sonogashira coupling reaction. Significant reduction of the HOMO−LUMO energy band gap and improvement of fluorescence quantum yield were observed upon incorporating pyrimidine into the conjugated backbone.

We report two patients with myopathic dropped head syndrome, a rare and interesting neuromuscular syndrome characterised by a predominant weakness of the neck extensor muscles. The first patient, a middle aged Chinese man, presented with progressive weakness of neck extension but his clinical course later stabilised despite a lack of response to corticosteroids. Muscle biopsy revealed a necrotising myopathy with no evidence of inflammation. This patient supports the existence of an idiopathic restricted non-inflammatory myopathy, a so called isolated neck extensor myopathy syndrome which is recognised to pursue a less progressive, more benign course. Our second patient had histopathological evidence for polymyositis; there was a favourable response to steroids. Our cases underscore the fact that there may be a spectrum of pathological processes associated with the myopathic dropped head syndrome ranging from non-inflammatory muscle necrosis to a full blown inflammatory myositis. Copyright 2000 Harcourt Publishers LtdCopyright 2000 Harcourt Publishers Ltd

Plasma cell granuloma of the breast is an extremely rare condition. Only one other case has been reported in the literature. We report here the second case of plasma cell granuloma of the breast. After the initial excision, the lesion recurred in both breasts after 5 months.

Established criteria for morphological typing of sarcocysts was applied to a large series of cases of human skeletal muscle sarcocystosis in Malaysia to determine the type of sarcocyst present. We also wanted to test the general usefulness of this classification and to determine if there are any new cyst types. Three-dimensional (3-D) reconstruction was done to see if the sarcocyst has a distinct 3-D morphology. A total of 66 sarcocysts from 21 cases of human muscle sarcocystosis obtained from a previous prevalence study were examined. Tissue sections (5 µm thick) were stained with haematoxylin and eosin and studied under the light microscope. For 3-D reconstruction, an, image analyser was used to align and reconstruct the sarcocyst after microscopic images had been captured with a charge-coupled device (CCD) camera. All the cysts best fit into the type 4 category. This classification is generally useful, although cyst wall characteristics and zoite size appear to be the most reliable criteria for classification. The cyst width averaged 77 µm (range, 30–137.5 µm). Cyst walls were smooth, had no cytophaneres and were less than 1 µm thick. No secondary cyst wall or surrounding inflammation was evident. Numerous cyst merozoites with diameters averaging 1 µm filled the cyst lumen. Although septa were not apparent, in many cysts, zoites were arranged in a unique, curvilinear fashion that suggested their presence. 3-D reconstruction showed the sarcocyst to be a long, tortuous “cylinder” with no branching or other distinguishing feature.

An increase in cases of acute febrile encephalitis occurred in Western Malaysia between September 1998 and May 1999, and a similar illness was reported in Singapore in March 1999. Most cases occurred in males who had been exposed to pigs, or among abattoir workers, and at least 100 deaths were reported. The illness was characterized by fever and headache, followed by drowsiness and disorientation; patients with severe cases developed seizures and coma within 24 to 48 hours. Concurrently, there were also illnesses and deaths among pigs in the same region, although the symptoms predominantly involved the respiratory system, and only a few pigs had signs of neurologic disease. From a cerebral spinal fluid specimen from a human patient, Dr. Chua and colleagues were successful in isolating a virus that was morphologically identified as belonging to the family Paramyxoviridae,and is now known as Nipah virus.

No abstract.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.