Chemical characteristics of aerosols at coastal station in Hong Kong.Ⅱ. Environmental behavior of trace elements during the April 1995 to April 1996

An one-year of sampling aerosol program was carried out during the period of April 1995 to April 1996 at coastal region, Cape D′Aguilar, in Hong Kong. The trace element composition of aerosol particles(TSP and PM 10 ) were measured and analyzed by using the Instrumental Neutron Activation Analysis(INAA) and Inductive Couple Plasma-Mass Spectrometry(ICP-MS) techniques. The results showed that the polluted elements such as: V, Zn, As, Pb, Cd, Sb, I, Se, Bi, with high enrichment factor(E.F) values, are derived from anthropogenic sources, while Sc, Al, Fe, Mn, Sm, La, Sr are less than 10 in E.F, these elements are related the crust and soil. The concentration of the trace elements are present seasonal variation i.e. summer low and winter high, whereas the V or noncrustal V(V *) present summer high and winter low, this phenomenon might be explained by local or regional oil combustion sources. Use three type of elemental ratio, e.g. La/Sm, Mn */V * and Bi/Al indicate that both TSP and PM 10 of La/Sm ratios are mainly related to soil and dust, Mn */V * are probably represent fossil combustion and Bi/Al are possibly associated with refuse incineration, ferromanganese alloys and aluminum production. The varimax rotation factor analysis for trace elements was performed. By means of the absolute principal component analysis(APCA) and multiple regression, the contribution of trace elements to possible sources and overall means of trace elements were estimated. The results showed that the present station is impacted by the anthropogenic species, although the quantities are different during the summertime and wintertime.

On the Variability and Correlation of Surface Ozone and Carbon Monoxide Observed in Hong Kong Using Trajectory and Regression Analyses

This paper investigates, the variability and correlation of surface ozone (Os) and carbon monoxide (CO) observed at Cape D'Aguilar in Hong Kong from 1 January 1994 to 31 December 1995. Statistical analysis shows that the average O3 and CO mixing ratios during the two years are 32±17ppbv and 305±191 ppbv, respectively. The O3/CO ratio ranges from 0.05 to 0.6 ppbv/ppbv with its frequency peaking at 0.15. The raw dataset is divided into six groups using backward trajectory and cluster analyses. For data assigned to the same trajectory type, three groups are further sorted out based on CO and NOX mixing ratios. The correlation coefficients and slopes of O3/CO for the 18 groups are calculated using linear regression analysis. Finally, five kinds of air masses with different chemical features are identified: continental background (CB), marine background (MB), regional polluted continental (RPC), perturbed marine (P*M), and local polluted (LP) air masses. Further studies indicate that O3 and CO in the continental and marine background air masses (CB and MB) are positively correlated for the reason that they are well mixed over the long range transport before arriving at the site. The negative correlation between O3 and CO in air mass LP is believed to be associated with heavy anthropogenic influence, which results from the enhancement by local sources as indicated by high CO and NOx and depletion of O3 when mixed with fresh emissions. The positive correlation in the perturbed marine air mass P*M favors the low photochemical production of O3. The negative correlation found in the regional polluted continental air mass RPC is different from the observations at Oki Island in Japan due to the more complex O3 chemistry at Cape D'Aguilar.

Pharmacological Investigation on the Qi-Invigorating Action of Schisandrin B: Effects on Mitochondrial ATP Generation in Multiple Tissues and Innate/Adaptive Immunity in Mice

Schisandrae Fructus, containing schisandrin B (Sch B) as its main active component, is recognized in traditional Chinese medicine (TCM) for its Qi-invigorating properties in the five visceral organs. Our laboratory has shown that the Qi-invigorating action of Chinese tonifying herbs is linked to increased mitochondrial ATP generation and an enhancement in mitochondrial glutathione redox status. To explore whether Sch B can exert Qi-invigorating actions across various tissues, we investigated the effects of Sch B treatment on mitochondrial ATP generation and glutathione redox status in multiple mouse tissues ex vivo. In line with TCM theory, which posits that Zheng Qi generation relies on the Qi function of the visceral organs, we also examined Sch B’s impact on natural killer cell activity and antigen-induced splenocyte proliferation, both serving as indirect measures of Zheng Qi. Our findings revealed that Sch B treatment consistently enhanced mitochondrial ATP generation and improved mitochondrial glutathione redox status in mouse tissues. This boost in mitochondrial function was associated with stimulated innate and adaptive immune responses, marked by increased natural killer cell activity and antigen-induced T/B cell proliferation, potentially through the increased generation of Zheng Qi.

The Essential Role of Zheng Qi in Promoting Health: From the Perspective of Chinese Medicine and Modern Medicine

The concept of Zheng Qi in traditional Chinese medicine (TCM) refers to the vital energy produced by the interaction of Yin and Yang forces in the body. Zheng Qi performs two main functions: Wei Qi (defensive Qi), which shields the body from external pathogens, and Ying Qi (nutritive Qi), which sustains the internal organs and enhances their functionality. In TCM, Chinese tonifying herbs can help restore the balance of Yin/Yang and Qi/Blood function in visceral organs (i.e., optimal physiological functions), thereby fostering the efficient production of Zheng Qi and enhancing health. To ensure the quality of Chinese herbal products, functional assays to measure Yin/Yang, Qi/Blood functions, and Zheng Qi production should be implemented. The efficacy of Yang and Qi herbs can be evaluated by their ability to increase mitochondrial ATP in cultured mouse cardiomyocytes, while Yin and Blood herbs are tested through their immunostimulatory effects on antigen-induced T/B cell proliferation in mouse splenocytes and the production of erythropoietin/nitric oxide in hepatocytes/vascular endothelial cells, respectively. Additionally, Zheng Qi’s effect can be gauged by examining natural killer cell activity and antigen-induced T/B cell proliferation in mice ex vivo. These assays act as biomarkers for assessing the quality and effectiveness of herbal health products within TCM theory.

Differential Effects of Yin- and Yang-Chinese Tonifying Herbs on Innate and Adaptive Immunity

The present study investigated the effect of treatment with methanolic extracts of Yin- and Yang-Chinese tonifying herbs on concanavalin A (Con A)/lipopolysaccharide (LPS)-stimulated splenocyte proliferation (adaptive immunity) and natural killer (NK) cell activity (innate immunity) in an ex vivo mouse model. The results indicated that while treatment with most Yin herbal extracts potentiated the Con A/LPS-stimulated splenocyte proliferation, only Yang (but not Yin) herbal extracts stimulated NK cell activity. The differential effects of Yin- and Yang-Chinese tonifying herbs on innate and adaptive immunity are consistent with the Chinese medicine theory which depicts the Yin and Yang functional components of Zheng Qi (vital energy), with the Yang component being responsible for the first line of defense against invading microorganisms (i.e., innate immunity) and the Yin oner serving as a follow-up defensive response (adaptive immunity).

The Electrical Resistivity of Cement Paste Incorporated with Retarder

A non contacting electrical resistivity measurement device was used for measuring the electrical resistivity of cement paste incorporated with retarder.The hydration process was divided into dissolving period,setting period,hardening period.With the increase of the retarder,the dissolution time will increase.The setting time happens between minimum point time and inflexion point time based on the electrical resistivity curve.The strength isoline was proposed to predict the strength trend.

Effect of Rubber Particles on Cement Stabilized Gravel System

The primary objective of this paper was to study the mechanical properties and durability of the cement stabilized gravel by different compact method. The influence of rubber particle content on mechanical properties of samples was studied by compaction tests and freezing thawing recycle tests. Pore structure and fractal characteristic of mixture were analyzed quantitatively using mercury intrusion porosimetry （MIP）. X-ray diffraction （XRD） was adopted to identify the composition phases. The morphology analysis in micro scale and elemental analysis of samples were carried out by scanning electron microscope （SEM）. The optimum compressive strengths of rubber cement stabilized gravel （RCSG） with static compaction method and with vibratory compaction method were obtained by controlling compaction degree and vibration time, respectively. From the compaction tests, the vibratory compaction method is preferred compared with the static compaction method as better compressive strength can be improved by about 340%-360%. Besides, test results also reveal that compressive strength of samples with vibratory compaction method or static compaction method will decrease with the rubber particle bulk content increasing. The freezing thawing recycle tests indicate that freezing thawing resistance has been improved （frozen stability coefficient K has been increased from 0.89 to 0.97） by the addition of rubber particles. MIP tests show that the mean pore diameter and porosity of mixture have been increased from 70 to 250 nm and 9% to 24% respectively, with the rubber particles content increasing. Component analysis shows that the calcium silicate hydrate （CSH） is the predominant hydrate product with or without the addition of rubber particles.

SYNTHESIS,CHARACTERIZATION AND OPTICAL PROPERTIES OF THE COPOLYMERS OF C_(60) AND 1-PHENYL-1-PROPYNE

While WCl_6-Ph_4Sn fails to polymerize 1-phenyl-1-propyne (PP) at room temperature, highmolecular weight (M_w up to 410× 10~3) polymers are obtained in high yields (up to 80%) when thepolymerizations of PP are carried out in the presence of C_(60) using the W catalyst under the same conditions.The polymers are soluble in common organic solvents such as THF, chloroform, and toluene. Molecularstructures of the polymers are characterized by FT-IR, UV, NMR, GPC and XRD, and it is found that C_(60) iscopolymerized with PP. Thus C_(60) plays the dual roles of comonomer and cocatalyst in the polymerizationreaction. C_(60) contents of the copolymers can be easily changed by varying the C_(60) amounts in the feedmixtures. The copolymers effectively limit strong 532 nm laser pulses, whose limiting performance issuperior to that of parent C_(60).

SYNTHESIS AND OPTICAL PROPERTIES OF POLY (THIENYLACETYLENES)

3-Ethynyl-4-(trimethylsilyl)thiophene (1a) and 3-ethynyl-4-bromothiophene (1b) selectively undergo acetylene polymerizations in the presence of the MoCl5- and WCl6-Ph3SiH catalysts to give soluble, high-molecular-weight poly(thienylacetylenes) (2) (M-w up to 602000) in high yields (up to 100%). Light transmission spectra of THF solutions of 2 continuously red-shift with increasing concentration. The concentratochromism shows a logarithmic concentration dependence; that is, the optical transitions of 2 are predictably tunable by simply changing their concentrations.

Fluidized-Bed Drying of Biological Materials:Two Case Studies

Drying is the last operation for processing most biomaterials. Due to the heat and moisture sensitivity of biomaterials, selections of drying methods and operating parameters are very important to keep the viability of these materials. In the present study, experiments were carried out in fluidized bed drying of photosynthetic microorganism liquid and mixed culture animal food. Results show that most activities can be kept in dried products. Appropriate operation parameters were determined.

Inter-Organ Relationships among Gut, Lung and Skin beyond the Pathogenesis of Allergies: Relevance to the Zang-Fu Theory in Chinese Medicine

Research on allergy has recently uncovered an apparent co-occurrence of allergies in skin and the lungs, a phenomenon that has been coined “atopic march”. A positive correlation has been found between gut microbiota at birth and the development of asthma and skin eczema later in life. Chinese medicine has long described a functional relationship between the large intestine and the lungs, and between the lungs and skin. In this short article, we examined the evidence in support of these inter-organ physiological/pathological relationships. In addition to the clinical observation of the relationship between the composition of gut microbiota at birth and the development of asthma later in childhood, gut microorganisms have also been shown to exert a protective effect on bacteria-induced pneumonia in experimental animals. Genetic predisposition was also found to play an important role in the co-existence of certain diseases of lung and skin. Despite the fact that the mechanism(s) underlying the connection of immune systems between two organs (such as the large intestine and the lungs) is still not clearly understood, it is the first time to correlate the relationship among gut, lung and skin based on recent clinical studies in relation to the Zang-Fu Theory in Chinese medicine. Future investigation of the gut-lung and lung-skin axes in terms of physiological/pathological relationships may help to provide a greater understanding of the pathogenesis of allergies, possibly establishing relevance to the Zang-Fu Theory in Chinese medicine.

INFLUENCE OF BACKBONE RIGIDITY ON THE LIQUID CRYSTALLINITY OF MESOGEN-CONTAINING POLYACETYLENES

Two acetylene polymers containing cyanobiphenyl-based mesogens, poly{10-[((4'-cyano-4-biphenylyl)oxy)carbonyl]-1-decyne} (PA8CN), which has a relatively flexible polyalkyne backbone, and poly {[4-(((12-((4'-cyano-4-biphenylyl)oxy)dodecyl)oxy) carbonyl) phenyl]-acetylene} (PB12CN), which has a fairly rigid poly(phenylacetylene) backbone, were synthesized using respectively WCl6 and [Rh(nbd)Cl](2) as the catalysts. PA8CN exhibits enantiotropic interdigitated smectic A phase (S-Ad) over a temperature range as wide as ca. 100 degrees C, whereas PB12CN is non-mesomorphic, demonstrating that the backbone rigidity plays an important role in determining the liquid crystallinity of the polyacetylenes.

SYNTHESIS AND PROPERTIES OF POLY(AROMATIC DIACETYLENE)S CONTAINING FLUORENE

Novel fluorene-based poly(aromatic diacetylene)s have been synthesized by CuCl-catalyzed oxidative coupling of aromatic diynes.New aromatic diynes 2,7-diethynyl-9,9-bis(triphenylamine)fluorene(M_1)is synthesized by multistep reactions.The structures and properties of the polymers are characterized and evaluated by IR,NMR,TGA,UV, photoluminescence(PL),and cyclic voltammetry analyses.These polymers possess good thermal stability.All the polymers are completely soluble in coammon solvents such as toluene,THF,c...

Effects of aspect ratio on flapping wing aerodynamics in animal flight

Morphology as well as kinematics is a critical determinant of performance in flapping flight.To understand the effects of the structural traits on aerodynamics of bioflyers,three rectangular wings with aspect ratios（AR）of1,2,and 4 performing hovering-like sinusoidal kinematics at wingtip based Reynolds number of 5 300 are experimentally investigated.Flow structures on sectional cuts along the wing span are compared.Stronger K-H instability is found on the leading edge vortex of wings with higher aspect ratios.Vortex bursting only appears on the outer spanwise locations of high-aspect-ratio wings.The vortex bursting on high-aspect-ratio wings is perhaps one of the reasons why bio-flyers normally have low-aspect-ratio wings.Quantitative analysis exhibits larger dimensionless circulation of the leading edge vortex（LEV）over higher aspect ratio wings except when vortex bursting happens.The average dimensionless circulation of AR1 and AR2 along the span almost equals the dimensionless circulation at the 50%span.The flow structure and the circulation analysis show that the sinusoidal kinematics suppresses breakdown of the LEV compared with simplified flapping kinematics used in similar studies.The Reynolds number effect results on AR4 show that in the current Re range,the overall flow structure is not sensitive to Reynolds number.

SYNTHESIS OF A HYPERBRANCHED POLY(AROYLARYLENE) CONTAINING TRIAZOLE AND FLUORENE FUNCTIONALITIES BY CLICK CHEMISTRY AND METAL-FREE,REGIOSELECTIVE POLYCYCLOTRIMERIZATION

A new bis(aroylacetylene) containing tfiazole and fluorene moieties is synthesized by click chemistry. Polycyclotrimerization of the monomer is catalyzed by piperidine in refluxed dioxane,furnishing a regioregular poly(aroylarylene) in a satisfactory yield.The hyperbranched structure of the polymer is characterized spectroscopically with satisfactory results.The polymer enjoys no metal detriment and is soluble in common organic solvents such as tetrahydrofuran (THF),chloroform,dichloromethane (DCM),and N,N-...

MULTI-DIMENSIONAL NUMERICAL STUDIES OF CONVECTION-RELATED STELLAR PROBLEMS

To assist researchers who are not in the numerical field specified by the title but who wish to get some understanding about the field, condensed reviews of the essential concepts, popular techniques, and recent works are given here.

Pharmacological Investigation of “Meridian Tropism” in Three “Shen” Chinese Herbs

“Meridian tropism” refers to the organ-specific biological action(s) produced by a Chinese herb following its oral administration, which is analogous to the concept of “bioavailability” in Western medicine. In this study, we compared the in vitro and ex vivo pharmacological actions of three herbs [namely, Dangshen (DS, Codonopsis Radix), Ranshen (RS, Ginseng Radix) and Xiyangshen (XYS, Panacis Qinquifolii Ra-dix)] to validate their meridian tropism. We compared the in vitro and ex vivo pharmacological actions [i.e. the ability to increase splenocyte proliferation and adenosine triphosphate-generation capacity (ATP-GC)] of the ethanolic extracts of DS, RS and XYS to validate their meridian tropism. Results showed that DS, RS and XYS (at 30 - 300 μg/mL) can both stimulate the proliferation of primary mouse splenocytes in vitro and increase adenosine triphosphate-generation capacity (ATP-GC) in cultured Caco 2 colon epithelial cells in vitro. Interestingly, oral administration of DS and RS (but not XYS, at 3 and 6 g/kg/day × 3 consecutive days) was found to stimulate the proliferation of splenocytes ex vivo at 24 h post-treatment in mice. Similarly, DS and RS (but not XYS) increased the ATP-GC of mitochondrial fractions isolated from a small segment of mouse intestine at 48 h post-treatment. This observation is consistent with the meridian tropism of the pharmacological action of “Shen”, i.e., the accessibility of DS and RS (but not XYS) to the “Spleen” meridian. The comparison between the results obtained from in vitro and in vivo/ex vivo bioassays may offer a potential method for assessing meridian tropism in Chinese herbs.

A Hypothetical Anti-Aging Mechanism of “Yang-Invigorating” Chinese Tonic Herbs

Chinese tonic herbs are generally classified into Yin and Yang categories based on their health-promoting action. Emerging evidence has suggested that in addition to up-regulating mitochondrial functional status, Yang tonic herbs also enhance cellular/mitochondrial antioxidant capacity, and may thus prevent age-related diseases and prolong the healthy part of lifespan (i.e. healthspan). The proposed biochemical mechanism underlying the antioxidant action of Yang tonic herbs involves a sustained and low level of mitochondrial reactive oxygen species production, which is secondary to the increased activity of the electron transport chain, with the possible involvement of mitochondrial uncoupling. “Yang invigoration” improves antioxidant defense in the body in the long term and thereby offers a promising prospect for preventing or possibly delaying age-related diseases and the detrimental effects of aging.

Antioxidant and Immunopotentiating Effects of <i>Cordyceps </i>Mycelium Extract, Chicken Essence, and Their Combination in Experimental Models

Cordyceps mycelium extract (Cs-4), Chicken Essence (CE), and their combination were investigated for antioxidant and immunomodulatory activities in mouse models. Long-term treatment with Cs-4 or CE at equivalent human doses improved antioxidant status in various tissues, as evidenced by the enhancement of mitochondrial glutathione redox status in the brain, liver, heart, and kidney of mice. Cs-4 or CE treatment also produced an immunomodulatory action, as indicated by the potentiation of Concanavalin A-/lipopolysaccharide-induced proliferation of mouse splenocytes ex vivo. While doubling of the equivalent human doses of Cs-4 and CE did not further enhance their antioxidant or immunopotentiating effects, the combined treatment with Cs-4 and CE at their respective equivalent human doses produced an additive effect, with the extents of stimulation being larger than those produced by Cs-4 or CE alone. The results have demonstrated for the first time that the combined use of Cs-4 and CE can produce an additive effect on both antioxidation and immunopotentiation that cannot otherwise be achieved by increasing the equivalent human doses of Cs-4 or CE alone.

A Unifying Theory of Aging between Modern Medicine and Traditional Chinese Medicine

With the increasing aging population around the world as a result of birth rates and advances in medical technologies, there is an urgent need to unravel the primary cause of aging, in the hope of developing a rational approach to retard the aging process. This is crucial to reduce the societal impact of aging. Although modern medicine and traditional Chinese medicine view the process of aging from different perspectives, this article aims to develop a common understanding between these two distinct medical systems in relation to the aging process. As such, a unified approach can hopefully be developed to effectively slow down the aging process. Modern medicine has proposed the “mitochondrial theory” of aging, which implicates a causal relationship between the rate of mitochondrial reactive oxygen species generation and lifespan as noted in a wide spectrum of primate species, while traditional Chinese medicine views aging as the result of a gradual depletion of congenital primordial Qi, which can be spared by the sufficient generation of postnatal pectoral Qi. By amalgamating the knowledge of modern medicine with that of traditional Chinese medicine in relation to aging, it is suggested that while Chinese tonifying herbs can be used to restore the balance of body functions enabling the generation of sufficient pectoral Qi, active ingredients isolated from Chinese tonifying herbs or other plant sources capable of inducing mitohormesis and mitophagy, as well as senolysis, can be used to retard the aging process.