The impact of air pollution on green investments: Green preference and investor sentiment.

Green assets are sensitive to environmental changes and are pivotal in achieving sustainable development. Some empirical studies have shown that air pollution, as part of environmental change, affects stock market investment; however, the mechanisms by which air pollution affects investment in green assets have not been explored in depth. This study investigates the impact of air pollution on green stocks through investor sentiment and green preference. Our empirical analysis reveals that declining air quality prompts negative investor sentiment, exerting an adverse impact on the stock market. Conversely, green preference exerts a positive influence on green stocks, with the magnitude of this effect being contingent on the degree of greenness (i.e., depth and breadth) of the stocks. Companies with a high degree of greenness experience a significant positive correlation between air pollution and stock prices, whereas this relationship is not significant for companies with lower greenness. Furthermore, the COVID-19 pandemic has served to alleviate the impact of air pollution on the stock market due to the diversion of public attention by COVID-19. These findings show that governments can take measures to mitigate negative impacts and facilitate green preference to promote green economic transformation and upgrading.

[The fenrou zhijian theory in The Inner Canon of Huangdi and the stratified treatment of painful bi syndrome of meridian tendons].

The fenrou zhijian is defined as potential gap between different layers in the three-dimensional network structure formed by the twelve meridian tendons. Various pathological changes of the meridian tendons lead to the adhesion and closure of fenrou zhijian, causing abnormal mechanical conduction of the meridian tendon system, which in turn leads to painful bi syndrome of meridian tendons. As such, restarting the fenrou zhijian is the key to acupuncture treatment for painful bi syndrome of meridian tendons. Under the guidance of musculoskeletal ultrasound, the level and the angle of needle insertion of acupuncture at fenrou zhijian could be accurately controlled, the efficacy of acupuncture is improved.

Clinical efficacy of electromagnetic field therapy combined with traditional Chinese pain-reducing paste in myofascial pain syndrome.

BACKGROUND: Pulsed electromagnetic field (PEMF) therapy is widely used to treat myofascial pain syndrome (MPS). Damp-clearing and pain-reducing paste (DPP) comprises medical herbs and has been a traditional method of reducing myofascial pain in China for a long time, and it is usually administered with heating. However, the synergistic effect of PEMF therapy on heating-DPP in patients with MPS is unclear. AIM: To investigate the synergistic effect of PEMF therapy plus heating-DPP in lumbar MPS. METHODS: This double-blind, randomized, placebo-controlled trial was conducted on 120 patients with lumbar MPS who were randomly divided into an experimental group (EG, n = 60) and a control group (CG, n = 60). Patients in both groups were treated with heating-DPP combined with PEMF therapy; however, the electromagnetic function of the therapeutic apparatus used in the CG was disabled. Each treatment lasted for 20 min and was applied five times a week for two weeks. The short-form McGill Pain Questionnaire was applied at five time points: pretest, end of the first and second weeks of treatment, and end of the first and fourth week after completing treatment. Visual analog scale (VAS), present pain intensity index (PPI), and pain rating index (PRI; total, affective pain, and sensory pain scores) scores were then analyzed. RESULTS: Compared with the CG, the VAS, PPI and PRI scores (total, affective pain and sensory pain scores) in the EG were significantly lower after treatment and during follow-up. CONCLUSION: PEMF therapy combined with heating-DPP showed better efficacy than heating-DPP alone in reducing the overall intensity of pain and sensory and affective pain.

Dysfunction of Emotion Regulation in Mild Cognitive Impairment Individuals Combined With Depressive Disorder: A Neural Mechanism Study.

Depression increases the risk of progression from mild cognitive impairment (MCI) to dementia, where impaired emotion regulation is a core symptom of depression. However, the neural mechanisms underlying the decreased emotion regulation in individuals with MCI combined with depressive symptoms are not precise. We assessed the behavioral performance by emotion regulation tasks and recorded event-related electroencephalography (EEG) signals related to emotion regulation tasks simultaneously. EEG analysis, including event-related potential (ERP), event-related spectral perturbation (ERSP), functional connectivity and graph theory, was used to compare the difference between MCI individuals and MCI depressed individuals in behavioral performance, the late positive potential (LPP) amplitudes, neural oscillations and brain networks during the processing of emotional stimuli. We found that MCI depressed individuals have negative preferences and are prone to allocate more attentional resources to negative stimuli. Results suggested that theta and alpha oscillations activity is increased, and gamma oscillations activity is decreased during negative stimulus processing in MCI depressed individuals, thus indicating that the decreased emotion regulation in MCI depressed individuals may be associated with enhanced low-frequency and decreased high-frequency oscillations activity. Functional connectivity analysis revealed a decrease in functional connectivity in the left cerebral hemisphere of the alpha band and an increase in functional connectivity in the right cerebral hemisphere of the alpha band in MCI depressed individuals. Graph theory analysis suggested that global network metrics, including clustering coefficients and disassortative, decreased, while nodal and modular network metrics regarding local nodal efficiency, degree centrality, and betweenness centrality were significantly increased in the frontal lobe and decreased in the parieto-occipital lobe, which was observed in the alpha band, further suggesting that abnormal alpha band network connectivity may be a potential marker of depressive symptoms. Correlational analyses showed that depressive symptoms were closely related to emotion regulation, power oscillations and functional connectivity. In conclusion, the dominant processing of negative stimuli, the increased low-frequency oscillations activity and decreased high-frequency activity, so as the decrease in top-down information processing in the frontal parieto-occipital lobe, results in the abnormality of alpha-band network connectivity. It is suggested that these factors, in turn, contribute to the declined ability of MCI depressed individuals in emotion regulation.

Improving the catalytic efficiency of Bacillus pumilus CotA-laccase by site-directed mutagenesis.

Bacterial laccases are potential enzymes for biotechnological applications because of their remarkable advantages, such as broad substrate spectrum, various reactions, high thermostability, wide pH range, and resistance to strongly alkaline environments. However, the use of bacterial laccases for industrialized applications is limited because of their low expression level and catalytic efficiency. In this study, CotA, a bacterial laccase from Bacillus pumilus, was engineered through presumptive reasoning and rational design approaches to overcome low catalytic efficiency and thermostability. L386W/G417L, a CotA double-mutant, was constructed through site-directed mutagenesis. The catalytic efficiency of L386W/G417L was 4.3 fold higher than that of wild-type CotA-laccase, but the thermostability of the former was decreased than that of the latter and other mutants. The half-life (t 1/2) of wild-type and G417L were 1.14 and 1.47 h, but the half-life of L386W/G417L was only 0.37 h when incubating the enzyme at 80 °C. Considering the high catalytic efficiency of L386W/G417L, we constructed L386W/G417L/G57F, another mutant, to improve thermostability. Results showed that the half-life of L386W/G417L/G57F was 0.54 h when incubating the enzyme at 90 °C for 2 h with about 34% residual activity, but the residual activity of L386W/G417L was less than 40% when incubating the enzyme at 90 °C for 5 min. L386W/G417L was more efficient in decolorizing various industrial dyes at pH 10 than other mutants. L386W/G417L/G57F also exhibited an efficient decolorization ability. L386W/G417L/G57F is appropriate for biotechnological applications because of its high activity and thermostability in decolorizing industrial dyes. CotA-laccase may be further subjected to molecular modification and be used as an enhancer to improve decolorization efficiency for the physical and chemical treatment of dye wastewater.

Synthesis of La-Co-O Mixed Oxides via Polyethylene Glycol-Assisted Co-Precipitation Method for Total Oxidation of Benzene.

La-Co-O mixed oxides (LCO) were prepared by co-precipitation method with the presence of polyethylene glycol (PEG) as dispersant. The influence of adding different molecular weight of PEG (0, 2 000, 6 000, 20 000 g·mol-1) on the physicochemical and catalytic properties of La-Co-O mixed oxides for total oxidation of benzene was investigated. The samples were characterized by means of N2 physical adsorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), temperature-programmed reduction by H2 (H2-TPR), temperature-programmed desorption of O2 (O2-TPD), and X-ray photoelectron spectroscopy (XPS). The order of catalytic activity was found to be LCO-PEG6000>LCO>LCO-PG20000>LCO-PG2000. Particularly, LCO-PEG6000 exhibited benzene conversion of 99% at temperature as low as 383 ℃, which was 126 ℃ lower than that of LCO. The characterization result reveals that all samples had a BET surface area of about 9～10 m2·g-1. The XRD result shows that on all samples LaCoO3 perovskite was mainly formed together with a small amount of La2O3 and Co3O4. The addition of PEG was favorable for the formation of LaCoO3 perovskite. Particularly, the addition of PEG-6000 effectively suppressed the agglomeration of LaCoO3 perovskite, giving rise to small and uniform particles as observed by SEM. Moreover, the results of H2-TPR and O2-TPD indicate that the obtained La-Co-O mixed oxides showed higher reducibility and lattice oxygen mobility, and the Co 2p XPS analysis suggests that more surface Co3+ active species were presented by the addition of PEG-6000. These properties are thought to contribute to the high activity in benzene total oxidation.

Cell microenvironment stimuli-responsive controlled-release delivery systems based on mesoporous silica nanoparticles.

To develop novel tumor cell microenvironment stimuli-responsive smart controlled-release delivery systems is one of the current common interests of materials science and clinical medicine. Meanwhile, mesoporous silica nanoparticles as a promising drug carrier have become the new area of interest in the field of biomedical application in recent years because of their unique characteristics and abilities to efficiently and specifically entrap cargo molecules. This review describes the more recent developments and achievements of mesoporous silica nanoparticles in drug delivery. In particular, we focus on the stimuli-responsive controlled-release systems that are able to respond to tumor cell environmental changes, such as pH, glucose, adenosine-5'-triphosphate (ATP), glutathione (GSH), and H(2)O(2).

Curative effect of radiotherapy at various doses on subcutaneous alveolar echinococcosis in rats.

BACKGROUND: Alveolar echinococcosis (AE) is a disease in human and animals, and the cure rate is unsatisfactory. This study aimed to investigate the curative efficacy of different doses of locally applied radiotherapy on alveolar echinococcosis in rats. METHODS: Rats infected with Echinococcus multilocularis were randomly divided into 4 groups of 15 rats each: low-, middle-, and high-irradiation groups and a control group. Rats in the control group underwent no treatment, while rats in the irradiation groups received 6-MeV radiotherapy at 20 Gy/8 f, 40 Gy/8 f, and 60 Gy/8 f respectively, once every 3 days for a total of 8 times. One month after radiotherapy, wet weight and AE vesicle inhibitory rate were detected in rats of each group. Histopathologic and ultrastructural observations of tissues with AE lesions were performed. RESULTS: In the treatment groups, an obvious inhibitory effect was found in AE rats; the inhibitory rates were 50%, 72%, and 82%, respectively. There were also statistical differences in pathological changes and average wet weight of the lesions compared with the control group (P < 0.05). In the treatment groups, injuries of various degrees were found in the ultrastructure of the laminated and germinal layers in the capsular wall of AE, and injury was most severe in the high-dose group. CONCLUSION: Radiotherapy has a dose-dependent inhibitory effect on the growth of AE.

[X-ray irradiation against Echinococcus multilocularis protoscoleces in vitro].

OBJECTIVE: To explore the effect of X-ray irradiation on Echinococcus multilocularis protoscoleces in vitro. METHODS: Echinococcus multilocularis protoscoleces were collected from cysts of infected Meriones meridianus and then cultured in RPMI 1640 medium. Protoscoleces were subpackaged into culture flasks at a density of about 10(4) per flask after culture for 3 days. Each group has 10 culture flasks. There were seven groups named as blank control group, low dose group (15 Gy and 30 Gy), medium dose group (45 Gy and 60 Gy), high dose group (75 Gy and 90 Gy), albendazole group (2 500 ng/ml), 45 Gy X-ray + 2 500 ng/ml albendazole group, and 75 Gy X-ray + 2 500 ng/ml albendazole group. Protoscoleces received three radiations on every other day with a source-skin distance of 100 cm and at a dose rate of 200 cGy/min after 3 days in culture. At each day after irradiation, protoscoleces were counted by light microscope with 0.1% eosin staining, and calculated mortality rate (per 100 protoscoleces) until all the parasites in experimental groups died. At the same time, the morphological changes of protoscoleces were observed. RESULTS: There were significant differences in protoscolex mortality between X-ray groups and blank control group (P < 0.05), between X-ray + albendazole groups and albendazole group (P < 0.05). Protoscolex mortality in albendazole group were higher than that of blank control group (P < 0.05). Significant difference were also found in protoscolex mortality between albendazole combined with radiation and radiation only (P < 0.05). Before radiation, protoscoleces was normal with complete structure. After radiation, the parasites were mostly valgus type protoscoleces with disordered rostellar hooks and deformed acetabulum, and finally died. CONCLUSION: X-ray can kill Echinococcus multilocularis protoscoleces in vitro.

[Effect of 6 MeV radiotherapy on secondary Echinococcus multilocularis infection in rats].

OBJECTIVE: To explore the effect of 6-MeV X-ray radiotherapy on secondary Echinococcus multilocularis infection in rats. METHODS: Female SD rats were used to develop a secondary infection model, and then randomly divided into experimental group and control group (5/group). Rats in experimental group received two irradiations at 7-day intervals with the same dose (20 Gy) which applied with 6-MeV ray. The rats in control group did not receive any treatment. At one month after the second irradiation, the pathomorphological changes of E. multilocularis cysts were observed. RESULTS: Cysts in experimental group showed different degrees of damage, including that the laminated layer and germinal layer became swollen and separated from each other, brood capsules and protoscoleces were rare. The structure of cysts was normal in control group, laminated layer and germinal layer were clear, and there were many protoscoleces in the brood capsule. CONCLUSION: 6 MeV radiotherapy can inhibit the growth of E. multilocularis.

Depression of reactivity by the collision energy in the single barrier H + CD4 -> HD + CD3 reaction.

Crossed molecular beam experiments and accurate quantum scattering calculations have been carried out for the polyatomic H + CD(4) --> HD + CD(3) reaction. Unprecedented agreement has been achieved between theory and experiments on the energy dependence of the integral cross section in a wide collision energy region that first rises and then falls considerably as the collision energy increases far over the reaction barrier for this simple hydrogen abstraction reaction. Detailed theoretical analysis shows that at collision energies far above the barrier the incoming H-atom moves so quickly that the heavier D-atom on CD(4) cannot concertedly follow it to form the HD product, resulting in the decline of reactivity with the increase of collision energy. We propose that this is also the very mechanism, operating in many abstraction reactions, which causes the differential cross section in the backward direction to decrease substantially or even vanish at collision energies far above the barrier height.

[Determination of palladium in automobile exhaust catalysts by FAAS method].

Palladium in automotive exhaust catalyst was determined by flame atomic absorption spectrometry (FAAS). The analytical conditions and the coexisting elements interference were studied. The catalyst was dissolved by the mixture of H2O2 and HCl. Pd in the solution was directly determined by FAAS method. The linearity of working curve ranges from 0.1 to 15 microg x mL(-1); the detection limit is 0.029 microg x mL(-1); the relative standard deviation (RSD) range is from 0.8% to 2.5%; and the recovery rate range is from 99.6% to 101.2%. It is a simple and convenient method for accurate analysis of Pd in the exhaust catalysts.

[Determination of protein by synchronous fluorometric method with a new indole homodimeric cyanine as fluorescence probe].

Using a new homodimeric hydrophilic indole dye (Dye-I) as fluorescence probe, a sensitive synchronous spectrofluorometric determination for protein was developed. Characteristics of the fluorescence reaction between DYE-1 and BSA protein were investigated. Effects of the concentration of the hydrophilic dye, pH value of the buffer solution, and ion-intensity of NaCl were also studied and the optimum condition was gained. At pH of 2.50, electrostatic interactions of positive charges of the BSA chain and negative charges on the sulfonic groups of DYE-1 were carried out. The interactions of the indole group of DYE-1 and some active groups of BSA (viz. amido, carboxyl or sulfhydryl) were also achieved, and resulted in the combination of indole group of dye at the chain of BSA, which caused a notable increase in synchronous fluorescence with an observable shift to the longer emission wavelength. Effects of the concentration of indole dye on the determination of BSA were also investigated. With the augmentation of BSA, the alpha-helix structure of BSA molecular would change from the unwrapped state to the enfolded state, which was in favor of restraining free-oscillation of fluorescence probe in the solution and maintaining a high energy transfer efficiency. Such a fact would fuel a high fluorescence enhancement and the change in fluorescence intensity (deltaF) gained the peak at 3.00 micromol x L(-1). The influences of ion-intensity of NaCl on the fluorescence of BSA-DYE-1 system was visible. Effects of coexistent substances such as amino acid and metal ions such as Cu2+, K+, Ca2+, Mg2+, Al3+, and Zn2+ were also investigated. Most substances showed no notable influences on the determination of BSA except Zn2+ and Cu2+ ions. Under the optimum conditions, good calibration curves of the protein were also obtained in the range of 5.00 x 10(-7) -2. 50 x 10(-5) g x mL(-1) (BSA) with a detection limit of 3 x 10(-8) g x mL(-1). Applied to simulant protein samples at the level of 1.00, 2.00, and 5.00 microg x mL(-1) of BSA, the recoveries were in the range of 98.6%-103.0% with the RSD of 1.1%-1.9%. Compared with the UV standard method, the relative deviation was obtained in the range of 0.4%-3.9%.

[Spectrofluorometric detection of protein with a novel hydrophilic cyanine dye].

A sensitive fluorescence quantitative determination for bovine serum albumin (BSA) or human serum albumin (HSA) has been developed by using a new hydrophilic cyanine dye 1, 1'-sulfonopropyl-3,3,3', 3'-tetramethylindolium-5,5'-disulfonic potassium (STDP) as a fluorescence probe. Using BSA as a representative protein, characteristics of the fluorescence reaction of STDP with protein were investigated. Effects of the concentration of the hydrophilic cyanine dye, pH value of the buffer solution, and ion-intensity of NaCl were also studied as well as the ratio of ethanol. In the citrate-HCl buffer solution, the fluorescence emission wavelength of BSA-STDP system was 562 nm with the maximum excitation wavelength of 548 nm, and the Stokes displacement was 14 nm. With the pH ranging from 1.0 to 2.0, the fluorescence was increasing and up to the maximum at pH 2.0. However, in the pH range of 3.0-5.0, the interaction of BSA and STDP was weakened due to the decrease in positive charge on the BSA chain, which resulted in an observable decrease of the enhancement of the fluorescence intensity. At the optimum pH of 2.0, electrostatic interactions of positive charges of the BSA chain and negative charges on the sulfonic groups of STDP were carried out. The interactions of the indole group of STDP and some active groups of BSA (viz. amido, carboxyl or sulfhydryl) were also achieved, and resulted in the combination of indole group of cyanine dye into the chain of BSA. So the hydrophobic effect and the protection provided by the skeleton chain of BSA were both improved to prevent the fluorescent energy of STDP from losing in the solution, which caused a notable fluorescence increase with an observable shift to the longer emission wavelength. Furthermore, with the augmentation of BSA, the alpha-helix structure of BSA molecular turned from the unwrapped state to the enfolded state, in favor of restraining free-oscillation of fluorescence probe in the solution and maintaining a high energy transfer efficiency. Such a fact fueled a highly enhancement of the fluorescence too. Besides, effects of the concentration of cyanine dye on the determination of BSA were also investigated. The fluorescence intensity (DeltaF) was enhanced with the increase in the quantity of STDP and gained the peak at 1.00 micromol x L(-1). However, when STDP ranged from 1.50 to 5.00 micromol x L(-1), some negative congregate effects on the nature of cyanine dye might happen and resulted in a too high fluorescence background. A rapid decrease of the fluorescence intensity was observed. The effects of ion-intensity of NaCl and ethanol on the fluorescence of BSA-STDP system were obvious. Though the fluorescence still remained high at the level of NaCl of 0.025 mol x L(-1), a rapid decrease happen at the level of NaCl from 0.05 to 0.15 mol x L(-1). With the addition of ethanol, the dissolvation capacity of both STDP and BSA was improved and their interactions were accelerated. An increasing fluorescence with the augment of ethanol was obtained and the maximum was achieved with the ratio of ethanol at 10%. Influences of coexistent substances such as amino acid, metal ions such as Cu2+, Na+, Ca2+, Mg2+, Al3+ and Fe3+ were also investigated. Most substances had no notable influences on the determination of BSA except Fe3+ and Cu2+ ions. Under the optimum conditions, the fluorescence of STDP was enhanced markedly with the addition of the BSA or HSA protein. Good calibration curves of the proteins were obtained in the range of 0.20-15.00 microg x mL(-1) for BSA and 0.20-12.00 microg x mL(-1) for HSA with detection limits (3sigma/K) of 0.01 microg x mL(-1). Applied to simulant BSA samples, this method was adaptable. And the results were satisfied with good recoveries ranging from 94.5% to 103.3% at the revels of 4.00, 6.00 and 8.00 microg x mL(-1) respectively.

[Study of the pH sensitive polymer].

A pH sensitive polymer was prepared by copolymerization of methacrylic acid as monomer, diethylene glycol dimethacrylate as cross-linking reagent, heptane as porogen, and fluorescent dye eosin as indicator. The factors of influence on the preparation, and the character of the pH sensitive polymer for pH were studied. The maximal emission wavelength of eosin was red shifted in the polymer than in solution, the apparent Ka largened, and the dissociation equilibrium of indicator was shifted to acidity direction, because the polarity of polymer diminished. Under the optimal condition, the calibration curve of the pH sensitive polymer covered the range of pH 0-3.0 with good reproduction and reversibility.

[Research of Hg2+ sol-gel membrane made of organically modified silicates].

A photochemical sensor for the determination of Hg2+ consisting of organically modified silicates (ormosils) was developed. Hg(2+)-sensitive fluorescent sol-gel films were prepared by co-condensation of tetramethoxysilane (TMOS) and dimethyldimethoxysilane (DMOS), and the fluorescent indicator 5,10,15, 20-tetra (p-sulfonatophenyl) porphyrin sodium was embedded in sol-gel in the form of ion pairs with cetyltrimethyl ammonium bromide. The optimization condition of preparation and response performance of sol-gel membrane were investigated. The experimental results showed a linear range of Hg2+ concentrations from 1.0 x 10(-5) to 1.0 x 10(-4) mol x L(-1) in a Tris-HCl buffer at pH 8.0 with fast response and good repetition. The indicators in the sol-gel membrane did not leak out and the sensor showed good selectivity over other metal ions.

[Determination of nucleic acids using toluidine blue as a fluorescence probe].

A new fluorimetric method has been developed for the determination of deoxyribonucleic acid (DNA) with toluidine blue (TB) as a fluorescence probe. It is based on the fluorescence quenching of toluidine blue in the presence of DNA. In Tris-HCl buffer solution (pH 8.5), the calibration graph was linear over the range 0.10-6.00 microg x mL(-1) for ctDNA, and the detection limit was 27 ng x mL(-1). The result of the determination of DNA of camphor tree's leaf by this method was satisfactory.

Thioacetamide chemically immobilized on silica gel as a solid phase extractant for the extraction and preconcentration of copper(II), lead(II), and cadmium(II).

Thioacetamide immobilized on silica gel was prepared via the Mannich reaction. The extraction and enrichment of copper(II), lead(II), and cadmium(II) ions from aqueous solutions has been investigated. Conditions for effective extraction are optimized with respect to different experimental parameters in both batch and column processes prior to their determination by flame atomic absorption spectrometry (FAAS). The optimum pH ranges for quantitative adsorption are 4.0-8.0, 2.0-7.0, and 5.0-10.0 for Pb(II), Cu(II), and Cd(II), respectively. Pb(II) and Cd(II) can be desorbed with 3 mol/L and 0.1 mol/L HCl/HNO3, and Cu(II) can be desorbed with 2.5% thiourea. The adsorption capacity of the matrix has been found to be 19.76, 16.35, and 12.50 mg/g for Pb(II), Cu(II), and Cd(II), respectively, with the preconcentration factor of approximately equal to 300 for Pb(II) and approximately equal to 200 for Cu(II) and Cd(II). Analytical utility is illustrated in real aqueous samples generated from distilled water, tap water, and river water samples.

[Study on beta-cyclodexdrin sensitizing catalytic kinetic spectrophotometric determination of Mn(II)].

A new catalytic spectrophotometric method for the determination of trace amount of Mn(II) has been developed. The method is based on the oxidation of alizarin green(AG) by potassium periodate in the presence of beta-cylodexdrin(beta-CD) as a sensitizer and nitrilotriacetic acid as an activator. The linear range of the method was 0-2.4 ng x mL(-1) for Mn(II), the determination limit was 0.097 ng x mL(-1), the relative standard deviation was 0.45% (n = 12) for 1.6 ng x mL(-1) of Mn(II), and the sensitivity was increased by a factor of 2.5 compared to that in the absence of the beta-CD. The method was used for the determination of Mn(II) in cereal samples and wine samples with satisfactory results. The mechanism of this reaction system was also presented.