Detection of hazardous chemical using dual-wavelength Raman spectroscopy in the ultraviolet region.

This study proposes a stand-off Raman spectroscopy system using dual-wavelength in the ultraviolet (UV) region to detect hazardous chemicals. The Raman spectrum generated by the UV excitation source avoids solar background noise during daytime for chemical detection as the spectrum is in the solar blind range. Wavelengths of 213 and 266 nm by 5th and 4th harmonics are generated from Nd:YAG laser. However, Raman spectra of chemicals exhibit different signal-to-noise ratios for both the excitation wavelengths; therefore, to detect such chemicals, Raman spectra by two sources are required. Raman spectra were acquired using a dual-wavelength laser and spectrometer with a single grating and detector at the wavelengths of 213 and 266 nm simultaneously. The Raman spectra of sulfuric acid, 2-chloroethyl ethyl sulfide, and dimethyl methylphosphonate were acquired and analyzed, thus highlighting the application of dual-wavelength Raman spectroscopy. For efficient chemical detection in the field, we have ensured that the system developed in this study is robust.

Current Scenario and Challenges in the Direct Identification of Microorganisms Using MALDI TOF MS.

MALDI TOF MS-based microbial identification significantly lowers the operational costs because of minimal requirements of substrates and reagents for extraction. Therefore, it has been widely used in varied applications such as clinical, food, military, and ecological research. However, the MALDI TOF MS method is laced with many challenges including its limitation of the reference spectrum. This review briefly introduces the background of MALDI TOF MS technology, including sample preparation and workflow. We have primarily discussed the application of MALDI TOF MS in the identification of microorganisms. Furthermore, we have discussed the current trends for bioaerosol detection using MALDI TOF MS and the limitations and challenges involved, and finally the approaches to overcome these challenges.

SFPQ, a multifunctional nuclear protein, regulates the transcription of PDE3A.

Phosphodiesterase 3A (PDE3A), a member of the cGMP-inhibited cyclic nucleotide phosphodiesterase (PDE) family, plays important roles in oocyte maturation and vascular smooth muscle cell proliferation. However, the molecular mechanisms that regulate PDE3A gene expression remain largely unknown. In this study, we investigated the transcriptional regulation of PDE3A , and found that the splicing factor proline and glutamine rich (SFPQ) protein modulated PDE3A mRNA levels. Multiple transcription start sites (TSS1, 2, and 3) were identified within the first exon of PDE3A using 5'-rapid amplification of cDNA ends (RACE). Variable expression levels of three PDE3A variants were also observed in human tissues and HeLa cells. Several putative SFPQ-binding sites were identified upstream of the regulatory region of PDE3A -TSSs using chromatin immunoprecipitation sequencing (ChIP-seq). Serum-induced PDE3A expression was affected by increasing the amount of SFPQ binding to the upstream regulatory region of PDE3A In addition, transcription of PDE3A was lower in human cervical adenocarcinoma cells compared to normal cervical tissue. Furthermore, over-expression of PDE3A induced sensitivity to anti-cancer therapeutic agent, 6-(4-(diethylamino)-3-nitrophenyl)-5-methyl-4,5-dihydropyridazin-3(2H)-one (DNMDP), in HeLa cells. Taken together, these results suggest that SFPQ functions as a transcriptional activator of PDE3A, which is involved in the regulation of DNMDP sensitivity , offering a novel molecular target for the development of anticancer therapies.

Green tea seed oil reduces weight gain in C57BL/6J mice and influences adipocyte differentiation by suppressing peroxisome proliferator-activated receptor-gamma.

Given that tea contains a number of chemical constituents possessing medicinal and pharmacological properties, green tea seed is also believed to contain many biologically active compounds such as saponin, flavonoids, vitamins, and oil materials. However, little is known about the physiologic functions of green tea seed oil. The aim of this study is to investigate the anti-obesity effects of green tea seed oil in C57BL/6J mice and in preadipocyte 3T3L-1 cell lines. In vivo, three groups of mice were fed with a standard diet, a high-fat diet containing 30% shortening, or 30% of green tea seed oil based on a standard diet for 85 days. The levels of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglyceride, glucose, and alanine aminotransferase in blood were analyzed at the end of the study. The mice given green tea seed oil gained less weight compared to mice given the shortening diet (p < 0.01). The plasma level of total cholesterol was decreased by a significant level of 32.4% in mice given the green tea seed oil compared to the mice given the shortening diet (p < 0.01). In addition, 3T3-L1 cells were treated for 2 days to evaluate effects of green tea seed oil on adipocyte differentiation. Green tea seed oil inhibited expression of peroxisome proliferator-activated receptor-gamma(2) and CCAAT/enhancer binding protein-alpha in adipocytes and adipose tissue from the experimental animals. These results indicate that the anti-obesity effects of green tea seed oil might be, in part, through suppression of transcription factors related to adipocyte differentiation.

Mechanistic insights into the reversible formation of iodosylarene-iron porphyrin complexes in the reactions of oxoiron(IV) porphyrin pi-cation radicals and iodoarenes: equilibrium, epoxidizing intermediate, and oxygen exchange.

We have shown previously that iodosylbenzene-iron(III) porphyrin intermediates (2) are generated in the reactions of oxoiron(IV) porphyrin pi-cation radicals (1) and iodobenzene (PhI), that 1 and 2 are at equilibrium in the presence of PhI, and that the epoxidation of olefins by 2 affords high yields of epoxide products. In the present work, we report detailed mechanistic studies on the nature of the equilibrium between 1 and 2 in the presence of iodoarenes (ArI), the determination of reactive species responsible for olefin epoxidation when two intermediates (i.e., 1 and 2) are present in a reaction solution, and the fast oxygen exchange between 1 and H(2)18O in the presence of ArI. In the first part, we have provided strong evidence that 1 and 2 are indeed at equilibrium and that the equilibrium is controlled by factors such as the electronic nature of iron porphyrins, the electron richness of ArI, and the concentration of ArI. Secondly, we have demonstrated that 1 is the sole active oxidant in olefin epoxidation when 1 and 2 are present concurrently in a reaction solution. Finally, we have shown that the presence of ArI in a reaction solution containing 1 and H(2)18O facilitates the oxygen exchange between the oxo group of 1 and H(2)18O and that the oxygen exchange is markedly influenced by factors such as ArI incubation time, the amounts of ArI and H(2)18O used, and the electronic nature of ArI. The latter results are rationalized by the formation of an undetectable amount of 2 from the reaction of 1 and ArI through equilibrium that leads to a fast oxygen exchange between 2 and H(2)18O.

A highly active zinc catalyst for the controlled polymerization of lactide.

We report the preparation, structural characterization, and detailed lactide polymerization behavior of a new Zn(II) alkoxide complex, (L(1)ZnOEt)(2) (L(1) = 2,4-di-tert-butyl-6-{[(2'-dimethylaminoethyl)methylamino]methyl}phenolate). While an X-ray crystal structure revealed the complex to be dimeric in the solid state, nuclear magnetic resonance and mass spectrometric analyses showed that the monomeric form L(1)ZnOEt predominates in solution. The polymerization of lactide using this complex proceeded with good molecular weight control and gave relatively narrow molecular weight distribution polylactide, even at catalyst loadings of <0.1% that yielded M(n) as high as 130 kg mol(-)(1). The effect of impurities on the molecular weight of the product polymers was accounted for using a simple model. Detailed kinetic studies of the polymerization reaction enabled integral and nonintegral orders in L(1)ZnOEt to be distinguished and the empirical rate law to be elucidated, -d[LA]/dt = k(p)[L(1)ZnOEt][LA]. These studies also showed that L(1)ZnOEt polymerizes lactide at a rate faster than any other Zn-containing system reported previously. This work provides important mechanistic information pertaining to the polymerization of lactide and other cyclic esters by discrete metal alkoxide complexes.