Broadband coherent Raman scattering spectroscopy at 50,000,000 spectra/s

Raman scattering spectroscopy is widely used as an analytical technique in various fields, but its measurement process tends to be slow due to the low scattering cross-section. In the last decade, various broadband coherent Raman scattering spectroscopy techniques have been developed to address this limitation, achieving a measurement rate of about 100 kSpectra/s. Here, we present a significantly increased measurement rate of 50 MSpectra/s, which is 500 times higher than the previous state-of-the-art, by developing time-stretch coherent Raman scattering spectroscopy. Our newly-developed system, based on a mode-locked Yb fiber laser, enables highly-efficient broadband excitation of molecular vibrations via impulsive stimulated Raman scattering with an ultrashort femtosecond pulse and sensitive time-stretch detection with a picosecond probe pulse at a high repetition rate of the laser. As a proof-of-concept demonstration, we measure broadband coherent Stokes Raman scattering spectra of organic compounds covering the molecular fingerprint region from 200 to 1,200 cm-1. This high-speed broadband vibrational spectroscopy technique holds promise for unprecedented measurements of sub-microsecond dynamics of irreversible phenomena and extremely high-throughput measurements

The relationship between histochemical enzyme activities of brain tumors and clinical features of the patients

Human brain turnors removed from 126 patients were histochemically examined and following results were obtained. 1. In general, alkaline phosphatase activity is decreased in poorly differentiated gliomas, but is not related to the tumor cell infiltration. 2. All the cases of alkaline phosphatase negative gliomas have poor reconvalescent course and most of the positive cases show good reconvalescence. 3. Alkaline phosphatase, leucine aminopeptidase and acid phosphatase activities are remarkable in fibroblastic meningioma, moderate or feeble in meningocytic meningioma, and negative in malignant meningioma. 4. The activities of alkaline phosphatase, &#946;-esterase, leucine aminopeptidase and acid phosphatase are decreased in most of meningocytic meningiomas when the duration of symptoms and signs is short. 5. Succinic dehydrogenase, malic dehydrogenase, isocitric dehydrogenase and &#946;-glucuronidase are strongly reactive in malignant meningioma; from strong to moderate in meningocytic meningioma and from moderate to feeble in fibroblastic meningioma. 6. There is a slight increasing tendency of the activities of succinic dehydrogenase, malic dehydrogenase, isocitric dehydrogenase in fibroblastic meningioma and p·glucuronidase for a short duration of symtoms and signs. 7. In the case of acoustic neurinomas the higher the alkaline phosphatase activity, the longer is the duration of symptoms and signs.</p

Mid-infrared optical coherence tomography with MHz axial line rate for real-time non-destructive testing

Non-destructive testing (NDT) is crucial for ensuring product quality and safety across various industries. Conventional methods such as ultrasonic, terahertz, and X-ray imaging have limitations in terms of probe-contact requirement, depth resolution, or radiation risks. Optical coherence tomography (OCT) is a promising alternative to solve these limitations, but it suffers from strong scattering, limiting its penetration depth. Recently, OCT in the mid-infrared (MIR) spectral region has attracted attention with a significantly lower scattering rate than in the near-infrared region. However, the highest reported A-scan rate of MIR-OCT has been 3 kHz, which requires long data acquisition time to take an image, unsatisfying industrial demands for real-time diagnosis. Here, we present a high-speed MIR-OCT system operating in the 3-4 um region that employs the swept-source OCT technique based on time-stretch infrared spectroscopy. By integrating a broadband femtosecond MIR pulsed laser operating at a repetition rate of 50 MHz, we achieved an A-scan rate of 1 MHz with an axial resolution of 11.6 um and a sensitivity of 55 dB. As a proof-of-concept demonstration, we imaged the surface of substrates covered by highly scattering paint coatings. The demonstrated A-scan rate surpasses previous state-of-the-art by more than two orders of magnitude, paving the way for real-time NDT of industrial products, cultural assets, and structures

Broadband dielectric spectroscopy of glucose aqueous solution: Analysis of the hydration state and the hydrogen bond network.

Recent studies of saccharides' peculiar anti-freezing and anti-dehydration properties point to a close association with their strong hydration capability and destructuring effect on the hydrogen bond (HB) network of bulk water. The underlying mechanisms are, however, not well understood. In this respect, examination of the complex dielectric constants of saccharide aqueous solutions, especially over a broadband frequency region, should provide interesting insights into these properties, since the dielectric responses reflect corresponding dynamics over the time scales measured. In order to do this, the complex dielectric constants of glucose solutions between 0.5 GHz and 12 THz (from the microwave to the far-infrared region) were measured. We then performed analysis procedures on this broadband spectrum by decomposing it into four Debye and two Lorentz functions, with particular attention being paid to the β relaxation (glucose tumbling), δ relaxation (rotational polarization of the hydrated water), slow relaxation (reorientation of the HB network water), fast relaxation (rotation of the non-HB water), and intermolecular stretching vibration (hindered translation of water). On the basis of this analysis, we revealed that the hydrated water surrounding the glucose molecules exhibits a mono-modal relaxational dispersion with 2-3 times slower relaxation times than unperturbed bulk water and with a hydration number of around 20. Furthermore, other species of water with distorted tetrahedral HB water structures, as well as increases in the relative proportion of non-HB water molecules which have a faster relaxation time and are not a part of the surrounding bulk water HB network, was found in the vicinity of the glucose molecules. These clearly point to the HB destructuring effect of saccharide solutes in aqueous solution. The results, as a whole, provide a detailed picture of glucose-water and water-water interactions in the vicinity of the glucose molecules at various time scales from sub-picosecond to hundreds of picoseconds

Somatic chromosomal translocation between Ewsr1 and Fli1 loci leads to dilated cardiomyopathy in a mouse model

A mouse model that recapitulates the human Ewing's sarcoma-specific chromosomal translocation was generated utilizing the Cre/loxP-mediated recombination technique. A cross between Ewsr1-loxP and Fli1-loxP mice and expression of ubiquitous Cre recombinase induced a specific translocation between Ewsr1 and Fli1 loci in systemic organs of both adult mice and embryos. As a result Ewsr1-Fli1 fusion transcripts were expressed, suggesting a functional Ews-Fli1 protein might be synthesized in vivo. However, by two years of age, none of the Ewsr1-loxP/Fli1-loxP/CAG-Cre (EFCC) mice developed any malignancies, including Ewing-like small round cell sarcoma. Unexpectedly, all the EFCC mice suffered from dilated cardiomyopathy and died of chronic cardiac failure. Genetic recombination between Ewsr1 and Fli1 was confirmed in the myocardial tissue and apoptotic cell death of cardiac myocytes was observed at significantly higher frequency in EFCC mice. Moreover, expression of Ews-Fli1 in the cultured cardiac myocytes induced apoptosis. Collectively, these results indicated that ectopic expression of the Ews-Fli1 oncogene stimulated apoptotic signals, and suggested an important relationship between oncogenic signals and cellular context in the cell-of-origin of Ewing's sarcoma

Molecular phylogeny and evolution of alcohol dehydrogenase (Adh) genes in legumes

BACKGROUND: Nuclear genes determine the vast range of phenotypes that are responsible for the adaptive abilities of organisms in nature. Nevertheless, the evolutionary processes that generate the structures and functions of nuclear genes are only now be coming understood. The aim of our study is to isolate the alcohol dehydrogenase (Adh) genes in two distantly related legumes, and use these sequences to examine the molecular evolutionary history of this nuclear gene. RESULTS: We isolated the expressed Adh genes from two species of legumes, Sophora flavescens Ait. and Wisteria floribunda DC., by a RT-PCR based approach and found a new Adh locus in addition to homologues of the Adh genes found previously in legumes. To examine the evolution of these genes, we compared the species and gene trees and found gene duplication of the Adh loci in the legumes occurred as an ancient event. CONCLUSION: This is the first report revealing that some legume species have at least two Adh gene loci belonging to separate clades. Phylogenetic analyses suggest that these genes resulted from relatively ancient duplication events

Chimeric Anti-PDPN Antibody ChLpMab-2

Human podoplanin (hPDPN ), a platelet aggregation‐inducing transmembrane glycoprotein, is expressed in different types of tumors, and it binds to C‐type lectin‐like receptor 2 (CLEC ‐2). The overexpression of hPDPN is involved in invasion and metastasis. Anti‐hPDPN monoclonal antibodies (mAbs) such as NZ ‐1 have shown antitumor and antimetastatic activities by binding to the platelet aggregation‐stimulating (PLAG ) domain of hPDPN . Recently, we developed a novel mouse anti‐hPDPN mAb, LpMab‐2, using the cancer‐specific mAb (CasMab) technology. In this study we developed chLpMab‐2, a human–mouse chimeric anti‐hPDPN antibody, derived from LpMab‐2. chLpMab‐2 was produced using fucosyltransferase 8‐knockout (KO ) Chinese hamster ovary (CHO )‐S cell lines. By flow cytometry, chLpMab‐2 reacted with hPDPN ‐expressing cancer cell lines including glioblastomas, mesotheliomas, and lung cancers. However, it showed low reaction with normal cell lines such as lymphatic endothelial and renal epithelial cells. Moreover, chLpMab‐2 exhibited high antibody‐dependent cellular cytotoxicity (ADCC ) against PDPN ‐expressing cells, despite its low complement‐dependent cytotoxicity. Furthermore, treatment with chLpMab‐2 abolished tumor growth in xenograft models of CHO /hPDPN , indicating that chLpMab‐2 suppressed tumor development via ADCC . In conclusion, chLpMab‐2 could be useful as a novel antibody‐based therapy against hPDPN ‐expressing tumors