In this paper, a nucleic acid protein analyzer based on Lambert-Beer law and ultraviolet spectrophotometry is introduced, which is composed of ultraviolet monochromatic light generator, photoelectric signal detection module, vortex mixer, touch screen and embedded central controller. For ultra-micro measurement, a continuous-wavelength full-spectrum spectrophotometric detection circuit is designed in the hardware part. The transmitted light signal is collected by silicon photodiode, amplified and processed by subsequent circuit, and then transmitted to a single chip computer STM32F407VGT6 with CortexTM-M4 core after A/D conversion. The concentration and purity of nucleic acid protein are evaluated by assistant software detection algorithm. The instrument has the characteristics of compact size, flexible use, simple operation, high sensitivity and high detection efficiency. The experimental results show that the instrument has good sensitivity, repeatability and accuracy, and is suitable for the ultra-micro measurement of nucleic acid sample concentration, purity and protein concentration.
Algorithms ; Nucleic Acids/analysis* ; Proteins ; Software ; Spectrophotometry, Ultraviolet

Artemisiae Argyi Folium,the dried leaves of Artemisia argyi,has been widely used in traditional Chinese and folk medicines for a long time. Qiai is one of the top-geoherb of Artemisiae Argyi Folium. Trying to investigate dynamic changes of chemical components of Qiai in different harvest periods and explore the optimum harvest time of Qiai,in this study,the contents of total flavonoids and total phenolic acids of 36 batches of Qiai collected in 6 different harvest periods were analyzed by ultraviolet-visible spectrophotometry. Furthermore,an HPLC method was applied for simultaneous determination of eight bioactive compounds including six phenolic acids( 5-caffeoylquinic acid,3-caffeoylquinic acid,4-caffeoylquinic acid,3,4-di-O-caffeoylquinic acid,3,5-di-O-caffeoylquinic acid and 4,5-di-O-caffeoylquinic acid) and two flavonoids( jaceosidin and eupatilin) in Qiai samples. The quantitative results indicated that there were some differences in the contents of total flavonoids,total phenolic acids and bioactive compounds of Qiai samples in different harvest periods. The dynamic changes of total flavonoids and total phenolic acids of Qiai in different harvest periods were consistent. The contents of total flavonoids and total phenolic acids of Qiai samples were higher in the third harvest period( around the Dragon Boat Festival),which is basically consistent with the traditional harvest periods. This present study can provide the basis for determining the suitable harvest time of Qiai,and might be useful for the quality evaluation of this herbal medicine.
Artemisia/chemistry* ; Chromatography, High Pressure Liquid ; Drugs, Chinese Herbal/chemistry* ; Flavonoids/analysis* ; Hydroxybenzoates/analysis* ; Plant Leaves/chemistry* ; Spectrophotometry, Ultraviolet ; Time Factors

PURPOSE: In this study, three bioceramic materials, [IPS Empress CAD (Ivoclar), IPS e.max CAD (Ivoclar), and Lava Ultimate CAD (3M ESPE)] were treated with three commercial mouthrinses [Listerine, Tantum Verde, and Klorhex]; and changes in colour reflectance and surface roughness values were then quantitatively assessed. MATERIALS AND METHODS: One hundred and twenty ceramic samples, with dimensions of 2 × 12 × 14 mm, were prepared and divided into nine sample groups, except three control samples. The samples were immersed in the mouthrinse solutions for 120 hrs, and changes in colour reflectance and surface roughness values were measured by UV light spectrophotometry (Vita Easyshade; VITA Zahnfabrik) and by profilometer device (MitutoyoSurftest SJ-301), respectively. The change of surface roughness was inspected by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). RESULTS: There was a positive correlation between the ΔE and increase in the surface roughness. Two of the ceramic materials, IPS Empress and Lava Ultimate, were affected significantly by the treatment of the mouthrinse solutions (P<.05). The most affecting solution was Tantum Verde and the most affected material was Lava Ultimate. As expected, the most resistant material to ΔE and chemical corrosion was IPS e max CAD among the materials used. CONCLUSION: This work implied that mouthrinse with lower alcohol content had less deteriorating effect on colour and on the surface morphology of the bioceramic materials.
Benzydamine ; Ceramics ; Corrosion ; Microscopy, Atomic Force ; Microscopy, Electron, Scanning ; Refractometry ; Spectrophotometry ; Ultraviolet Rays

This study is to develop a sensitive method by using reversed-phase high performance liquid chromatography coupled with UV detector (HPLC-UV) to simultaneously determine four bioactive compounds, iriflophenone 3-C-beta-D-glucoside, iriflophenone 3,5-C-beta-D-diglucoside, mangiferin, and iriflophenone 2-O-alpha-L-rhamnoside in the leaves of Aquilaria sinensis. An Agilent Zorbax SB-C, column (4, 6 mm x 250 mm, 5 microm) was used, and the gradient elution was performed with mobile phase of 0.1% aqueous phosphoric acid and acetonitrile at a flow rate of 1 mL x min(-1). The detection wavelength was 280 nm, and the column temperature was 25 degrees C. The four marker compounds were well separated with good linearity (R2 > 0.9990), precision, stability and repeatabili y. The-recovery rates were in the range of 98.80%-101.39%. For 15 branch of the leaves, the contents of iriflophenone 3-C-beta-D-gluoside, iriflophenone 3,5-C-beta-D-diglucoside, mangiferin, and iriflophenone 2-O-alpha-L-rhamnoside were between 0.41-14.48, 0.72-3.85, 4.30-29.07, 0.24-5.06 mg, respectivley. This method is precise, accurate and reliable, which provides an efficient way for the quality control of the leaves of A. sinensis. This will promote the comprehensive usage of this plant.
Benzophenones ; analysis ; Chromatography, High Pressure Liquid ; methods ; Drugs, Chinese Herbal ; analysis ; Plant Leaves ; chemistry ; Spectrophotometry, Ultraviolet ; methods ; Thymelaeaceae ; chemistry ; Xanthones ; analysis

This article explores the possible influencing factor and regular pattern of temperature rise induced by photo-thermal effect of gold nanorods when irradiated with near infrared region (NIR) laser. We used transmission electron microscope and UV-Vis-NIR spectrometer to characterize gold nanorods, then used 808 nm NIR laser with different power to irradiate the gold nanorods in different conditions and measured the temperature of the above solution. The higher the concentration of gold nanorods, the faster the temperature rose and the bigger its amplitude was. When the concentration of gold nanorods was fixed, the relation between power of laser and amplitude of temperature rise was linear. Temperature rise was also related to the shape of container. It could be concluded that amplitude of temperature rise of gold nanorods reaction system was related with concentration of the particles, irradiated power and shape of the container, so that we could control the temperature easily by regulating the irradiated power size of NIR laser in the experiments.
Gold ; Lasers ; Light ; Microscopy, Electron, Transmission ; Nanotubes ; Spectrophotometry, Ultraviolet ; Spectroscopy, Near-Infrared ; Temperature

OBJECTIVE: To explore the interaction between cefdinir (CE) and bovine serum albumin (BSA) by fluorescence and ultraviolet-visible absorption spectrometry.
 METHODS: Under the optimal conditions, the interaction between CE and BSA was investigated by fluorescence and ultraviolet-visible absorption spectrometry.
 RESULTS: CE could quench (static quenching) the intrinsic fluorescence of BSA by forming the CE-BSA complex. The main binding forces were considered as hydrogen bonds and Van der Waals forces based on the calculated values of the thermodynamic parameter. The process of binding was spontaneous because Gibbs free energy change was negative. The primary binding site for CE was located at sub-domain II of BSA. The values of Hill's coefficients were less than 1, indicating a negative cooperative effect. Synchronous fluorescence spectra showed that the conjugation reaction between CE and BSA did not affect the conformation of BSA, and the binding site was close to the tyrosine residue.
 CONCLUSION This test provides a theoretical basis for revealing the pharmacokinetic issue and the development for new drugs.
Binding Sites ; Cefdinir ; Cephalosporins ; chemistry ; Serum Albumin, Bovine ; chemistry ; Spectrophotometry, Ultraviolet ; Thermodynamics

Humans ; Serum ; chemistry ; Spectrophotometry, Ultraviolet ; methods ; Sulpiride ; blood

The marine biological source of mineral drugs recorded in Chinese Pharmacopoeia (2010 version) mainly including pearl, nacre, clam shell, common oyster shell, ark shell, cuttle bone, and sea-ear shell are widely used in clinical. Calcium carbonate and a small amount of protein are the main components in this type of drugs. In this paper, a systematical and comparable study were carried out by determination of calcium carbonate by EDTA titration method, the crystal of calcium carbonate by X-Ray powder diffraction and the total amino acids (TAAs) of the hydrolyzed samples by ultraviolet spectrophotometry method. As a result, the crystal structure is calcite for common oyster shell, mixture of calcite and aragonite for nacre and sea-ear shell, aragonite for the other drugs. The content of calcium carbonate ranged from 86% to 96%. Cuttle bone has the highest amount of TAAs among the seven drugs which reached 1.7% while clam shell has the lowest content of 0.16% on average. In conclusion, an effective method was developed for the quality control of marine mineral drugs by comprehensive analysis of calcium carbonate and TAAs in the seven marine mineral drugs.
Amino Acids ; analysis ; chemistry ; Animal Shells ; chemistry ; Animals ; Calcium Carbonate ; analysis ; chemistry ; Crystallization ; Edetic Acid ; chemistry ; Mollusca ; chemistry ; classification ; Pharmaceutical Preparations ; analysis ; chemistry ; standards ; Quality Control ; Reproducibility of Results ; Seawater ; Species Specificity ; Spectrophotometry, Ultraviolet ; X-Ray Diffraction

This paper reports the determination of the drug antibody ratio in an antibody-drug conjugate with two methods, i.e. LC-MS and UV/VIS, and to provide a reliable method to scientifically evaluate and effectively control the drug antibody ratio. Deglycosylated sample was analyzed with C4 column followed by MS, and the number of conjugated drugs in the antibody was determined by the molecular weight increase due to the addition of different number of drugs to the antibody, and then drug antibody ratio was calculated by weighted average of different number of drugs conjugated to the antibody. Optical density at 252 and 280 nm was measured with UV/VIS, and due to the difference of extinction coefficients between the antibody and the drug, the drug antibody ratio was calculated from linear equation with two unknowns. The drug antibody ratio was 3.21 and 3.25 respectively measured by the two methods, and the results were similar with the two methods. Our study indicated that both methods, LC-MS and UV/VIS, could be applied to the analysis of drug antibody ratio of the antibody drug conjugate.
Antibodies ; analysis ; chemistry ; Gas Chromatography-Mass Spectrometry ; methods ; Glycosylation ; Immunoconjugates ; analysis ; chemistry ; Maleimides ; analysis ; chemistry ; Molecular Weight ; Pharmaceutical Preparations ; analysis ; chemistry ; Spectrophotometry, Ultraviolet ; methods

OBJECTIVETo study the molecular action mechanism of active constituents desoxyrhaponticin (DES) and human serum albumin (HSA).

METHODUnder the simulated physiological condition, computer analog technology, fluorescent spectrometry and ultraviolet spectrum were combined to study the binding mechanism between drug and protein.

RESULTMolecular modeling was adopted to establish the binding model between DES and HSA, suggesting that the interaction force maintaining drug and protein is mainly the hydrophobic interaction with a hydrogen-bond interaction. The results from spectroscopy indicated that the interaction between DES and HSA is a dynamic binding process with a high intensity. The value of the binding distance (r) between DES and HSA was low, which demonstrate the occurrence of energy transfer. DES made an impact on HSA' structural domain microcell conformation, which resulted in hydrophobic changes in binding areas. According to the fluorescent phase diagram technical analysis, the changes in the DES-HSA reaction conformational pattern showed a "two-state" model. According to the obtained thermodynamic parameters for the DES-HSA interaction, the interactional force between DES and HSA was mainly a hydrophobic interaction. The fluorescence polarization proved that a non-covalent compound was generated during the interaction between DES and HSA.

CONCLUSIONThe spectrum experiment showed consistent results with the computer analog technology, which could provided certain reference for studies on the interaction between DES and HSA.

Humans ; Models, Molecular ; Protein Binding ; Protein Conformation ; Serum Albumin ; chemistry ; metabolism ; Spectrometry, Fluorescence ; Spectrophotometry, Ultraviolet ; Stilbenes ; metabolism ; Thermodynamics