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Cortical hem signaling center: functions, development, and potential implications for evolution and brain disorders

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Neural Regeneration Research 2025年第4期20卷 1079-1080页

作者： Victor V.Chizhikov Igor y.Iskusnykh Department of Anatomy and Neurobiology University of Tennessee Health Science CenterMemphisTNUSA

Development of the telencephalon relies upon several signaling centers-localized cellular populations that supply secreted factors to pattern the cortical *** such signaling center is the cortical hem,which arises during embryonic development at the telencephalic dorsal midline,adjacent to the choroid plexus and hippocampal primordium(Figure 1A).While the cortical hem has also been described in reptiles and birds,most of our knowledge about the developmental roles of the cortical hem is derived from the analysis in *** cortical hem produces several types of secreted molecules,including wingless-related integration site(Wnt)and bone morphogenetic(Bmp)*** cortical hem is particularly important for the development of the hippocampus,which is involved in learning and memory,and the neocortex,which is the most complex brain region that mediates multiple types of behavior and higher cognitive functions(Mangale et al.,2008;Dal-Valle-Anton and Borrell,2022).

关键词： epithelium Figure center

Programmed cell death in developing human fetal CNS

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Chinese Science Bulletin 2000年第22期45卷 2082-2084页

作者： chan W.y. Department of Anatomy Faculty of MedicineThe Chinese University of Hong KongShatinN.T.Hong KongChina

The spatial and temporal distributions of programmed cell death (PCD) in developing central nervous system (CNS) of human fetuses ranging from 12 to 39 weeks of gestation were investigated using techniques of flow cytometry and terminal transferase-mediated nick end labeling (TUNEL). The results showed that PCD did occur in every representative brain region of all fetuses examined in different stages. It was found that there were two peaks of PCD appearing at the 12th and 39th weeks respectively, which suggested that the first peak of apoptosis may be involved in the selective elimination of neurons overproduced during the early development and the second may play an important role in establishing the correct neuronal circuitry.

关键词： programmed cell death (PCD) fetus central nervous system development.

Performance of LIDAR- and radar-based turbulence intensity measurement in comparison with anemometer-based turbulence intensity estimation based on aircraft data for a typical case of terrain-induced turbulence in association with a typhoon

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第7期14卷 469-481页

作者： P.W.chan y.F.LEE Hong Kong Observatory

The Hong Kong Observatory (HKO) provides low-level turbulence alerting service for the Hong Kong International Airport (HKIA) through the windshear and turbulence warning system (WTWS). In the WTWS, turbulence intensities along the flight paths of the airport are estimated based upon correlation equations established between the surface anemometer data and the turbulence data from research aircraft before the opening of the airport. The research aircraft data are not available on day-to-day basis. The remote sensing meteorological instruments, such as the Doppler light detection and ranging (LIDAR) and radar, may be used to provide direct measurements of turbulence intensities over the runway corridors. The performances of LIDAR- and radar-based turbulence intensity data are studied in this paper based on actual turbulence intensity measurements made on 423 commercial jets for a typical case of terrain-induced turbulence in association with a typhoon. It turns out that, with the tuning of the relative operating characteristic (ROC) curve between hit rate and false alarm rate, the LIDAR-based turbulence intensity measurement performs better than the anemometer-based estimation of WTWS for turbulence intensity at moderate level or above. On the other hand, the radar-based measurement does not perform as well when compared with WTWS. By combining LIDAR- and radar-based measurements, the performance is slightly better than WTWS, mainly as a result of contribution from LIDAR-based measurement. As a result, the LIDAR-based turbulence intensity measurement could be used to replace anemometer-based estimate for non-rainy weather conditions. Further enhancements of radar-based turbulence intensity measurement in rain would be necessary.

关键词： Fault tolerant High availability quadruple vital computer (HAQVC) Reliability availability maintainability and safety (RAMS)

Synthesis and properties of poly(1-phenyl-1-octyne)s containing stereogenic and chromophoric pendant groups

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Science China Chemistry 2009年第10期52卷 1691-1702页

作者： LAM Jacky W.y. JIM Cathy K.W. KWOK Hoi sing Department of Chemistry The Hong Kong University of Science & Technology Center for Display Research The Hong Kong University of Science & Technology

Poly(1-phenyl-1-octyne)s containing different stereogenic and chromophoric pendants {-[(C6H13)C= C(C6H4-p-CO2-R)] n -R = [(1S)-endo]-(?)-borneyl (P3), (1R,2S,5R)-(?)-menthyl (P4), -C6H4-p-(1R,2S,5R)-(?)-menthyl (P5), 2-napthyl (P6), 4-biphenylyl (P7)} have been designed and synthesized. The polymers are prepared in moderate yields by WCl6-Ph4Sn and possess high molecular weights (M w up to 64000). The structures and properties of the polymers are characterized and evaluated by NMR, TGA, UV, CD, PL, and EL analyses. All the polymers are thermally stable and their temperatures for 5% weight loss locate in the range of 300 to 416°C under nitrogen. The energy band gaps of all the polymers are ～3.0 eV. Polymers P4 and P5 show CD absorptions associated with the helicity of the polymer segments. Excitation of the THF solutions of P3–P7 by UV irradiation gives strong blue lights of ～485 nm with quantum yields higher than 20%. The thin films of the polymers also emit in the same spectral region, indicative of little aggregation-caused quenching of light emission. Multilayer EL devices with a configuration of ITO/Polymer:PVK/BCP/Alq3/LiF/Al are constructed, which emit blue lights of ～487 nm. The maximum luminance and external quantum efficiency vary with the pendant groups, with P6 exhibiting the highest external quantum efficiency of 0.16%. The spectra stability of the EL devices is outstanding and the EL peak maximum experiences little change with the applied voltage.

关键词： chiral photoluminescence polyacetylene electroluminescence helicity

Purge and trap method to determine alpha factors of VOC liquid-phase mass transfer coefficients

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Chinese Science Bulletin 2000年第S1期45卷 76-79页

作者： S.C.Lee L.y.chan C.y.chan Department of Civil & Structural Engineering The Hong Kong Polytechnic UniversityHong KongChina Correspondence should be addressed to Wang XinmingDepartment of Civil & Structural EngineeringThe Hong Kong Polytechnic UniversityHong KongChina Correspondence should be addressed to Wang XinmingDepartment of Civil & Structural EngineeringThe Hong Kong Polytechnic UniversityHong KongChina Correspondence should be addressed to Wang Xinming

A theoretical approach and laboratory practice of determining the alpha factors of volatile organic compound (VOC) liquid-phase mass transfer coefficients are present in this study. Using Purge & Trap Concentrator, VOC spiked water samples are purged by high-purity nitrogen in the laboratory, the VOC liquid-phase mass transfer rate constants under the laboratory conditions are then obtained by observing the variation of VOCs purged out of the water with the purge time. The alpha factors of VOC liquid-phase mass transfer coefficients are calculated as the ratios of the liquid-phase mass transfer rate constants in real water samples to their counterparts in pure water under the same experimental conditions. This direct and fast approach is easy to control in the laboratory, and would benefit mutual comparison among researchers, so might be useful for the study of VOC mass transfer across the liquid-gas interface.

关键词： mass transfer coefficient purge and trap volatile organic compounds alpha factor.

Perception of Potential Health Risk of Climate change and Utilization of Fans and Air Conditioners in a Representative Population of Hong Kong

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International Journal of Disaster Risk Science 2020年第1期11卷 105-118页

作者： yang Gao Emily y.y.chan Holly C.y.Lam Aiwei Wang Department of Sport and Physical Education Hong Kong Baptist UniversityHong KongChina Collaborating Centre for Oxford University and CUHK for Disaster and Medical Humanitarian Response The Jockey Club School of Public Health and Primary CareThe Chinese University of Hong KongHong KongChina

Climate change, especially as reflected in heat waves, is a rising threat worldwide. Appropriate use of cooling devices can protect people from health impacts during a heat wave. A population-based telephone survey was conducted in a representative sample of residents in Hong Kong to investigate ownership and use of domestic cooling devices, identify correlates, and examine their associations with risk perception of potential health impact of climate change. More than 90% of the 1002 respondents owned and used cooling devices at home. The majority(57.7%) perceived the potential health risk of climate change at a high level. However, risk perception had no relationship with ownership and utilization of cooling devices. Old people(≥ 65 years), the low-educated, those with low income, and those with chronic diseases were more likely not to use air conditioners when feeling *** findings suggest that there are no signs showing people have taken more protective actions although half of respondents recognized climate change as a threat. Familial economic condition may be a major determinant in ownership and use of air conditioners at home. Old people and those with chronic diseases are at high risk of adverse exposure to climate change and therefore should be equipped with appropriate measures to use cooling devices.

关键词： Climate change Domestic cooling device Heat wave health impact Hong Kong Risk perception

Exercise preconditioning alleviates ischemia-induced memory deficits by increasing circulating adiponectin

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Neural Regeneration Research 2025年第5期20卷 1445-1454页

作者： Meifeng Zheng Borui Zhang Sonata S y yau Kwok-Fai So Li Zhang Haining Ou Department of Rehabilitation Medicine Guangzhou Medical UniversityGuangzhouGuangdong ProvinceChina Department of Rehabilitation Medicine The Fifth Clinical College of Guangzhou Medical UniversityGuangzhouGuangdong ProvinceChina Key Laboratory of CNS Regeneration(Ministry of Education) Guangdong-Hong Kong-Macao Institute of CNS RegenerationJinan UniversityGuangzhouGuangdong ProvinceChina Department of Rehabilitation Sciences The Hong Kong Polytechnic UniversityHong Kong Special Administrative RegionChina State Key Laboratory of Brain and Cognitive Science Li Ka Shing Faculty of MedicineThe University of Hong KongHong Kong Special Administrative RegionChina Center for Exercise and Brain Science School of PsychologyShanghai University of SportShanghaiChina Neuroscience and Neurorehabilitation Institute University of Health and Rehabilitation SciencesQingdaoShandong ProvinceChina

Cerebral ischemia is a major health risk that requires preventive approaches in addition to drug *** exercise enhances neurogenesis and synaptogenesis,and has been widely used for functional rehabilitation after *** this study,we determined whether exercise training before disease onset can alleviate the severity of cerebral *** also examined the role of exercise-induced circulating factors in these *** mice were subjected to 14 days of treadmill exercise training before surgery for middle cerebral artery *** found that this exercise pre-conditioning strategy effectively attenuated brain infarct area,inhibited gliogenesis,protected synaptic proteins,and improved novel object and spatial memory *** analysis showed that circulating adiponectin plays a critical role in these preventive effects of *** activation of adiponectin receptors by Adipo Ron mimicked the effects of exercise,while inhibiting receptor activation abolished the exercise *** summary,our results suggest a crucial role of circulating adiponectin in the effects of exercise pre-conditioning in protecting against cerebral ischemia and supporting the health benefits of exercise.

关键词： adiponectin cerebral ischemia exercise pre-conditioning hippocampus memory function middle cerebral artery occlusion prefrontal cortex synaptic proteins treadmill exercise

Synthetic brochosomes:Design,synthesis,and applications

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Nano Research 2024年第2期17卷 734-742页

作者： Lin Wang Jinsol Choi Tak-sing Wong Department of Mechanical Engineering The Pennsylvania State UniversityUniversity ParkPA 16802USA Materials Research Institute The Pennsylvania State UniversityUniversity ParkPA 16802USA Department of Biomedical Engineering The Pennsylvania State UniversityUniversity ParkPA 16802USA

Brochosomes,which are nanoscopic buckyball-shaped granules produced by leafhoppers,are one of the most intricate structures discovered in *** functions of brochosomes have been proposed but only a few have been experimentally validated due to the challenge of fabricating their synthetic *** in micro-and nanofabrication have recently led to the emergence of synthetic brochosomes,opening up new possibilities for innovative *** review explores the early discovery of natural brochosomes and their geometrical features,followed by the recent progress in fabricating synthetic brochosomes and their *** on future applications and challenges in the scalable manufacturing of synthetic brochosomes are discussed.

关键词： synthetic brochosomes leafhopper antireflection superhydrophobicity surface-enhanced Raman scattering photocatalyst energy harvesting

Pancreatic enzyme replacement therapy for pancreatic exocrine insufficiency in the 21^(st) century

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World Journal of Gastroenterology 2014年第33期20卷 11467-11485页

作者： Tony Trang Johanna chan David y Graham Department of Medicine Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine Houston TX 77030 United States

Restitution of normal fat absorption in exocrine pancreatic insufficiency remains an elusive goal. Although many patients achieve satisfactory clinical results with enzyme therapy, few experience normalization of fat absorption, and many, if not most, will require individualized therapy. Increasing the quantity of lipase administered rarely eliminates steatorrhea but increases the cost of therapy. Enteric coated enzyme microbead formulations tend to separate from nutrients in the stomach precluding coordinated emptying of enzymes and nutrients. Unprotected enzymes mix well and empty with nutrients but are inactivated at pH 4 or below. We describe approaches for improving the results of enzyme therapy including changing to, or adding, a different product, adding non-enteric coated enzymes,(e.g., giving unprotected enzymes at the start of the mealand acid-protected formulations later), use of antisecretory drugs and/or antacids, and changing the timing of enzyme administration. Because considerable lipid is emptied in the first postprandial hour, it is prudent to start therapy with enteric coated microbead prior to the meal so that some enzymes are available during that first hour. Patients with hyperacidity may benefit from adjuvant antisecretory therapy to reduce the duodenal acid load and possibly also sodium bicarbonate to prevent duodenal acidity. Comparative studies of clinical effectiveness of different formulations as well as the characteristics of dispersion, emptying, and dissolution of enteric-coated microspheres of different diameter and density are needed; many such studies have been completed but not yet made public. We discuss the history of pancreatic enzyme therapy and describe current use of modern preparations, approaches to overcoming unsatisfactory clinical responses, as well as studies needed to be able to provide reliably effective therapy.

关键词： Pancreatic insufficiency Pancreatic enzyme replacement therapy Lipase Clinical trials Steator-rhea Fat malabsorption Chronic pancreatitis