At pH 1.7, a combination of rhein with some nucleic acids such as calf thymus DNA(ctDNA) or yeast RNA(yRNA), can result in a great quenching of resonance light scattering and the maximum scattering wavelength appears at 481 nm. Based on this, a new method for the determination of trace amounts of nucleic acids has been developed. Under optimal conditions, the calibration graphs are linear over the range of 0.045-9.0μg/mL for ctDNA and 0.060-9.0μg/mL for yRNA. The corresponding detection limits are 33.9 ng/mL for ctDNA and 45.9 ng/mL for yRNA, respectively. The method has been applied to determine the ctDNA and yRNA in four synthetic samples and three real samples with a recovery range between 98.5% and 101.2%. Moreover, the quenching reasons of RLS and the interaction mechanism have been primarily discussed and the coplanarity change of rhein molecule before and after combination with ctDNA have been calculated.
OBJECTIVE:To study the effect of the hematostatic effective components of Herba Lamiophlomis rotata on rat’s blood conglomeration parameters.The toxicity of these components was simultaneously studied.METHODS:Herba Lamiophlomis rotata water extract (HLRE)(3g·kg-1),Total Flavonoids(P1,0.36g·kg-1),Total Iridoid Glycosides(P2,0.99g ·kg-1),Maximus Polarity Components(P3,1.65g·kg-1)and normal sodium NS were given orally in rats for 14 days.Blood samples were collected from common carotid artery;prothrombin time (PT),activated partial thromboplastin time (APTT),thrombin time (TT)and fibrinogen (FIB)were tested.Different oral doses of(P2 ,1.4,0.7,0.35 g·kg-1)and Yunnan white powder (BY,0.9g·kg-1)were given to rats and conglomeration parameters were determined too.The maximum tolerable dose (MTD)and LD50 of mice were determined after different doses of P2 were given with oral administration and intraperitoneal injection.RESULTS:Compared to NS control group,each composition of Lamiophlomis rotata Kudo can shorten the TT by 18.59%、—3.12%、24.11%and 9.92%respectively,and increase the content of FIB by 25.32%、8.67%、28.29%and 5.36%respectively.There was obvious change in HLRE and P2(P0.05).After 14 days intragastric administration of different dosage P2,TT decreased and FIB increased.As compared to NS and BY,the high dose group had significantly change (P0.05),meanwhile there was no obvious diffenrence in PT.High dosage can remarkedly increase APTT (P0.05).Given 55g·kg-1 of P2 with oral administration,there was no significant toxicant and adverse reaction in mice.But ginven P2 with intraperitoneal injection,the MTD was 5.31g·kg-1 and LD50 was 7.834g·kg-1.CONCLUSIONS:The Total Iridoid Glycosides (P2)of Herba Lamiophlomis rotata can increase the contents of FIB and shorten TT value with a good dose-effect relationship.No visible toxicant and adverse reactions were observed in mice after oral administration.The Total Iridoid Glycosides is safer than water extract.
Abstract A flow coulometric detector was applied to a study of the separation of heavy metal ions by cation exchange chromatography using succinate as an eluent. The separation of Fe, Cd, Zn and Go was carried out within 20 minutes under suitable conditions. The IEC behavior of the ions was discussed and the following formula was obtained: where VR, Z/r are the retention volume and ion-potential of the ion, a and b are constants. The formation constants of three ions were determined with HPIEC method. The suitable working voltage of the detector was selected from theory and reported in the experimental part. The amount of Zn, Cu and Fe in samples was determined.
Objective To evaluate the predictive value of serum C-reactive protein(CRP) for hospital death events in patients with severe community-acquired pneumonia(CAP).Methods The clinical data of 202 patients with CAP in Changhai Hospital and Second People's Hospital of Wuxi between Sep.2006 and Sep.2010 were retrospectively reviewed.The clinical and laboratory parameters,including the serum CRP level,white blood cell count,erythrocyte sedimentation rate(ESR) and serum creatine concentration were collected from Hospital Information System(HIS) and Laboratory Information System(LIS).The patients were divided into two groups according to the final death(CAP related complications) or survival of patients in the hospital.The receiver operating curve(ROC) analysis and multivariable logistical model were used to assess the predictive value of CRP on hospital death events.Results The median(interquartile range) serum CRP level of survival patients and patients who died during the hospital stay were 167.00(132.50,208.50) mg/L and 327.00(246.25,411.50) mg/L,respectively(Z=-7.481,P0.001).ROC analysis showed that CRP was an effective predictor for hospital death of CAP patients,with the area under curve(AUC) being 0.85(95%CI: 0.78-0.91).The optimal cot-off value for serum CRP was 230.50 mg/L,with the sensitivity being 0.83(95%CI: 0.76-0.89) and specificity being 0.79(95%CI: 0.65-0.89).Logistic regression analysis showed that,after adjusted for age,serum creatinine and ESR,CRP on admission was still independently associated with hospital death of CAP patients(OR=13.42,P0.01).Conclusion Increased CRP is an independent risk factor for hospital death events in patients with severe CAP.
The 683 guideline data in UCI machine-learning database in the diagnosis of breast cancer were analyzed by the correlation analysis, stepwise regression analysis and principal component analysis methods for the ?rst time. The uniformity of cell size (X2) and the uniformity of cell shape (X3) were the key guideline data.
Abstract A flow injection kinetic method has been developed for the determination of nitrite, based on its catalytic effect on bromate oxidation of chlorophosphonazo-pN in H2SO4 medium. The reaction is followed spectrophotometrically by measuring the decrease in the absorbance at 551 nm. The sampling frequency was 83 h−1. The calibration curve was linear between 0.050 and 1.00 μg/ml, and the detection limit was 0.018 μg/ml. The proposed method was applied to the determination of nitrite in waters and soil with satisfactory results.
A fluorescence Rayleigh light scattering (RLS) method for the determination of the amounts of deoxyribonucleic acid (DNA) was established by using hematoxylin as a fluorescent probe.The RLS intensity of hemt-DNA system was greatly enhanced at pH 7.3 Tris-HC1 buffer solution,and the intensity was proportional to the concentration of DNA in the range of 0.5～100μg/mL.The detection limit was 3.61μg/mL.In the reaction system,thermodynamic parametersΔH0 andΔS0 indicated the driving forces for the interaction between hematoxylin and DNA were mainly hydrophobic and electrostatic forces.
Abstract A room temperature flow injection spectrofluorimetric method is presented for the determination of niobium(V), based on the use of morin in the presence of cetyltrimethylammonium bromide(CTAB). Various chemical and physical variables affecting the reaction in the flow system were evaluated. The proposed method is very sensitive, with a detection limit of 3.0 ng/ml and a linear calibration graph in the range 8.0 to 240.0 ng/ml. The sampling frequency is 60 h −1 . The method has been successfully applied to the determination of niobium in steel samples.
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