Toward the development of Raman spectroscopy as a nonperturbative online monitoring tool for gasoline adulteration.

There is a critical need for a real-time, nonperturbative probe for monitoring the adulteration of automotive gasoline. Running on adulterated fuel leads to a substantive increase in air pollution, because of increased tailpipe emissions of harmful pollutants, as well as a reduction in engine performance. Consequently, both classification of the gasoline type and quantification of the adulteration content are of great significance for quality control. Gasoline adulteration detection is currently carried out in the laboratory with gas chromatography, which is time-consuming and costly. Here, we propose the application of Raman spectroscopic measurements for on-site rapid detection of gasoline adulteration. In this proof-of-principle report, we demonstrate the effectiveness of Raman spectra, in conjunction with multivariate analysis methods, in classifying the base oil types and simultaneously detecting the adulteration content in a wide range of commercial gasoline mixtures, both in their native states and spiked with different adulterants. In particular, we show that Raman spectra acquired with an inexpensive noncooled detector provides adequate specificity to clearly discriminate between the gasoline samples and simultaneously characterize the specific adulterant content with a limit of detection below 5%. Our promising results in this study illustrate, for the first time, the capability and the potential of Raman spectroscopy, together with multivariate analysis, as a low-cost, powerful tool for on-site rapid detection of gasoline adulteration and opens substantive avenues for applications in related fields of quality control in the oil industry.

Combined confocal Raman and quantitative phase microscopy system for biomedical diagnosis.

We have developed a novel multimodal microscopy system that incorporates confocal Raman, confocal reflectance, and quantitative phase microscopy (QPM) into a single imaging entity. Confocal Raman microscopy provides detailed chemical information from the sample, while confocal reflectance and quantitative phase microscopy show detailed morphology. Combining these intrinsic contrast imaging modalities makes it possible to obtain quantitative morphological and chemical information without exogenous staining. For validation and characterization, we have used this multi-modal system to investigate healthy and diseased blood samples. We first show that the thickness of a healthy red blood cell (RBC) shows good correlation with its hemoglobin distribution. Further, in malaria infected RBCs, we successfully image the distribution of hemozoin (malaria pigment) inside the cell. Our observations lead us to propose morphological screening by QPM and subsequent chemical imaging by Raman for investigating blood disorders. This new approach allows monitoring cell development and cell-drug interactions with minimal perturbation of the biological system of interest.

Platelet function in pregnant women receiving aspirin and dipyridamole.

PURPOSE: This study was undertaken to evaluate the hemostasis and coagulation profile of pregnant women receiving antiplatelet therapy with low-dose aspirin and dipyridamole for prevention of preeclampsia, intrauterine growth retardation, or pregnancy losses. METHODS: Twenty-three pregnant women who received antiplatelet therapy with combined aspirin (40 mg.day(-1)) and dipyridamole (150 mg.day(-1)) were enrolled in the study. Platelet aggregation and coagulation tests were performed before the start of aspirin and dipyridamole, during medication, and at 3 days and 6 days after cessation of medication. RESULTS: Collagen-induced platelet aggregation was decreased during medication (25 +/- 26%, P < 0.001) and at 3 days after cessation of medication (46 +/- 35%, P < 0.001) compared with that before the start of medication (89 +/- 7%). ADP-induced platelet aggregation was decreased during medication compared with that before medication (66 +/- 18% vs 92 +/- 7%, P < 0.001). The platelet count, prothrombin time, activated partial thromboplastin time, bleeding time, and levels of fibrinogen and antithrombin III did not change over time. The blood loss of these patients during vaginal delivery and cesarean section did not differ from that of normal women during vaginal delivery and repeat cesarean section, respectively. CONCLUSION: At the doses used in this study, aspirin and dipyridamole inhibited platelet aggregation for up to 3 days after cessation of medication. This abnormality of aggregation was not detected by the bleeding time and was not associated with clinically abnormal bleeding.

Mevalonic acidemia: first case of Japan.

Mevalonic acidemia is a rare metabolic disorder due to mevalonate kinase deficiency which affects the biosynthesis of cholesterol and nonsterol isoprenes. We report the first case of Japan. The clinical course is characterized by intrauterine growth retardation, postnatal growth failure, intractable diarrhea, liver dysfunctions and death at three months of age. Dysmorphic features including triangular face, protrusion of forehead, hypertelorism, low set ears and micrognathism were noted. High mevalonic acid level was found by GC/MS.