ftr-raman spectra of human dental enamel, both laser-irradiated and untreated, are reported. spectra are compared with hydroxyapatite. it is evident that unlike the co2 laser, the nd/yag laser does not induce any chemical change in dental enamel.

h-point standard addition method (hpsam) was applied for the simultaneous determination of v(v) and fe(iii). the method is based on the complex formation of v(v) and fe(iii) with chromazurol s (cas) in acidic media and in the presence of cetyltrimethylammonium bromide (ctab) as a micellizing agent. acidic media and the presence of a micellar system improve selectivity and sensitivity. fe (iii) ...

fibers of poplar wood (populus nigra l.) were prepared and oven dried. afterwards, they were acetylated with acetic anhydride without a catalyst. acetylation was carried out for different durations at 120ºc. different weight percentage gains (wpgs) were achieved based on the operating conditions. acetylated fibers were exposed to varying levels of relative humidity to determine equilibrium mois...

introduction: the aim of this study was to in-vestigate the effect of irradiation duration and distance of light tip to prepared samples in two different light curing unites on the degree of conversion of resin composite. materials and methods: conventional halogen and blue light emitting diode (led) units were used for polymerization of an opalis resin com-posite. the conversion measurements w...

surface-enhanced raman spectroscopy (sers) is a promising tool in the analytical science because it provides good selectivity and sensitivity without the labeling process required by fluorescence detection. this technique consists of locating the target analyte on nanometer range of roughed au-nanoparticles. the presence of the metal nanoparticles provides a tremendous enhancement to the result...

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background: the seminal plasma is an excellent source for noninvasive detection of spermatogenesis. the seminal plasma of normospermic and azoospermic men has been analyzed for detection of spermatogenesis. methods: optical spectroscopy (attenuated total reflectance-infrared spectroscopy (atr-ir) and fourier transform infrared spectroscopy (ft-ir) has been used to analyze the seminal plasma and...

in this study, laser induced breakdown spectroscopy (libs) is used for qualitative analysis of healthy and carious teeth. the technique of laser ablation is receiving increasing attention for applications in dentistry, specifically for the treatment of teeth such as drilling of micro-holes and plaque removal. in the process of ablation a luminous micro-plasma is normally generated which may be ...

Objective(s): Determination of stages of colon cancer is done by biopsy usually after surgery. Metabolomics is the study of all the metabolites using LC-MS and 1HNMR spectroscopy with chemometric techniques. The stages of colon cancer were detected from patients' sera using 1HNMR. Materials and Methods: Five ml blood was collected from 16 confirmed patients referred for colonoscopy.  One group ...

in this study, copper chromite (cucr2o4) nanoparticles was prepared by inverse co-precipitation method. in this method, cupric nitrate trihydrate, (cu (no3)2.3h2o) and chromium nitrate nonahydrate, (cr (no3) 3.9h2o) with a mole ratio of 1:2 were used. characterization of cucr2o4 nanoparticles was performed by fourier transform infrared spectroscopy (ft-ir), raman spectroscopy, x-ray diffraction...