[Perceived stress in general public during prevalence of severe acute respiratory syndrome and its impact on health behavior].

OBJECTIVE: To find out the perceived stress in general public during prevalence of severe acute respiratory syndrome (SARS) and its impact on health behavior. METHODS: A retrospective survey was conducted in Guangzhou, Hangzhou, and Taiyuan according to the epidemic situations of SARS, and 2532 subjects were randomly selected from constructive industry, school, and commercial business and residents in urban and rural areas. The perceive stress was measured by Chinese perceived stress scale (CPSS), and health related behavior during SARS was tested by uniform and self-made questionnaire. EpiData 2.0 was used for data management and CPSS value was calculated according to answer to 14 questions contained in the scale. Health risk stress among different population group and health related behavior among low, medium and high stress state were analyzed by SPSS 11.5. RESULTS: 2424 subjects were involved in the survey. The CPSS value was measured from 0 - 49 (22.7 +/- 6.8), M = 24.0. 39.3% (953/2379) subjects were under the health risk stress. The health related behaviors such as washing hands, opening the window for air, keeping away from others when cough and sneeze, doing exercises etc were reduced with the stress increased. Logistic regression indicated that compared with the persons with the thoughts of nothing serious of SARS, without any dread of SARS, and knowing nothing about prevention of SARS, the perceived stress was significantly related with perceiving of the thread to certain extent (beta = 0.41, Wald chi(2) = 4.84, P = 0.03), worrying little about the epidemic (beta = 0.50, Wald chi(2) = 6.69, P = 0.01), worrying about it to certain extent (beta = 1.39, Wald chi(2) = 48.59, P = 0.00) and scared so much (beta = 1.77, Wald chi(2) = 53.59, P = 0.00), and knowing little about the prevention (beta = 0.74, Wald chi(2) = 4.48, P = 0.03), knowing something about prevention (beta = -0.98, Wald chi(2) = 8.29, P = 0.00) and knowing the prevention very well (beta = -1.18, Wald chi(2) = 10.66, P = 0.00). CONCLUSION: The adoption of health related behaviors declined with increase of perceived stress. Opening connection to authority and government, enhancing the awareness of outburst affairs among general public and providing positive social support may be effective ways to reduce the population perceived stress.

[Mechanism studies on the combination reaction between bovine serum albumin and zincon by fluorescence spectra].

The characteristics of binding reaction between bovine serum albumin (BSA) and zincon (ZCN) were studied by fluorescence spectra and ultraviolet-visible absorption spectra. The bovine serum albumin can emit fluorescence (lamda(em) = 345 nm) under irradiation of ultraviolet light (lamda(ex) = 280 nm). After the zincon (ZCN) was added into BSA solution the fluorescence of BSA was quenched partially. The results indicated that ZCN was strongly bound to BSA. According to Stern-Volmer equation and Lineweaver-Burk equation, the quenching constant and the thermodynamic parameters were obtained. From the thermodynamic parameters the binding power between ZCN and BSA can be judged. The binding distance (r = 5.07 nm) and energy transfer efficiency (E = 0.67) between donor (BSA) and acceptor (ZCN) were obtained by Forster's non-radiative energy transfer mechanism. It is confirmed that the combination reaction between ZCN and BSA is a single static quenching process, and their interaction may be interpreted with energy transfer mechanism.

[Study on the chemical reaction of DNA with Congo red].

The interaction of deoxyribonucleic acid(DNA) and Congo red (GGH) was investigated by UV-Vis spectrophotometry in Tris-HCl solution (pH 4.56). When DNA was added into GGH solution, the color of the system changed from red to purple, which indicated the formation of the DNA-GGH complex. The maximum absorption of the complex is at 600 nm. The molar absorptivity measured at this wavelength epsilon = 1.41 x 10(5) L x cm(-1) mol(-1), the maximum binding number is n = 32, and the detection limit is c = 8.04 x 10(-8) mol x L(-1). The basic reaction condition of best pH value, time, and temperature, and the interference of different materials on the system were also studied. The ionic strength could affect the absorption of the system. The interaction of small molecule and DNA, the molecule structure, and the relationship between the molecule conformation and the distribution of electron cloud were studied.

[Studies on the thermodynamics and mechanism of combination reaction of titan yellow with bovine serum albumin].

The characteristics of the binding reaction of titan yellow(TY) with bovine serum albumin(BSA) were studies by fluorescence and ultraviolet-visible absorption spectra. It was shown that TY has a powerful ability to quench the fluorescence intensity of BSA. The fluorescence quenching data were analyzed according to Stern-Volmer equation and Line weaver-Burk equation and the binding constant, and thermodynamic parameters were obtained. According to the thermodynamic parameters the main sorts of binding force were determined. The binding distance and energy transfer efficiency between the donor (BSA) and the acceptor (TY) were obtained by Förster's non-radiative energy transfer mechanism. It is confirmed that the combination reaction of TY with BSA is a single static quenching process, and their interaction may be interpreted with energy transfer mechanism.

[Study on the chemical reaction of cytosine with 3,3',5,5'-tetrabromo-m-cresojsulphonphthalein].

The system of reaction for t he cytosine (Cy) and 3,3',5,5'-tetrabrono-m-cresojsulphonphthalein (XJFL) was studied in acid solution using UV spectra. The factors that affect the reaction, such as temperature, time and concentration of ion were determined. The maximum absorption peak of the complex appeared at t he wavelength 620 nm, the molar absorptivity was epsilon = 1.32 x 10(3) L x cm(-1) x mol(-1), the linear range of standard was 0-32 micro x mL(-1), and the maximum combining number was 16. The reaction mechanism, and the interaction of inorganic substance, biological substance, and surface active agent were studied.

[Study on the reaction of Lys-ZCN-CTMAB complex].

The interaction of lysozyme (Lys), O-{2-[alpha-(2-Hydroxy-5-Sulphophenlylazo)-benzylidene] hydrazino} benzoic acid (ZCN) and cetyltrimethy ammonicumbromide (CTMAB) was investigated by UV spectrophotometric method. The effect of temperature, time, and ion intensity in the buffer solution (pH 4.46) on reaction system was determined. Linear range of the reaction was 0-10 microg x mL(-1). The molar absorptivity was epsilon = 4.6164 x 10(5) L x cm(-1) x mol(-1). The reaction mechanism and interference of inorganic substance, biological substance and surface active agent to the reaction was investigated. Study system was established.