Direct Identification of Disaccharide Structural Isomers Using Ambient Ionization Tandem Mass Spectrometry with In Situ Methylation.

Carbohydrates play critically important roles in energy supply and biological functions in living systems. However, it has been a great challenge to identify saccharides and distinguish their isomers because they have highly similar structures and many possible positions for glycosidic linkages. In this work, an ambient ionization tandem mass spectrometry method was developed to characterize disaccharide structural isomers with in situ methylation. The direct analysis in real time ion source can be used to facilitate the methylation reaction of disaccharides with tetramethylammonium hydroxide. The hydroxyl groups of disaccharides can be methylated instantaneously, and the products can be ionized at the same time. The methylated product ions from full scan mass spectrometry (MS) and tandem MS can be used to distinguish a variety of disaccharide structural isomers with different glycosidic linkages, compositions, and configurations. Characteristic marker ions were discovered, and they can be used for the assignment of linkage type and identification of specific isomeric forms. The method was used for the direct identification of disaccharide isomers from real commercial products such as honey, wine, and milk without complex sample pretreatment or chromatographic separation.

Influence of spatial incident angles on polarizer with a slit in grooved metal slabs for terahertz communication.

We report the influence of two spatial incident angles on a terahertz polarizer, which is based on an aluminum slab with a center slit flanked by symmetrically distributed parallel grooves on both sides. Experimental results show that the polarizer shows narrow bandpass filtering effect with a very small divergence angle at normal incidence, which is very suitable for terahertz communication, and the extinction ratio (ER) can be achieved above 20 dB in the frequency band between 0.3 and 0.36 THz due to the excitation of spoof surface plasmon. As the structure rotates around the slit direction (ß), the transmission peak will split into two and degrade quickly and the ER decreased down to 20 dB for ß=10° at peak position. Rotating along grating period direction (γ) shows better tuning performance. The tuning frequency window can reach from 0.3 to 0.36 THz to promise an ER above 20 dB as γ is smaller than 25°.

A new novel mutation in FBN1 causes autosomal dominant Marfan syndrome in a Chinese family.

PURPOSE: Screening of mutations in the fibrillin-1 (FBN1) gene in a Chinese family with autosomal dominant Marfan syndrome (MFS). METHODS: It has been reported that FBN1 mutations account for approximately 90% of Autosomal Dominant MFS. FBN1 mutations were analyzed in a Chinese family of 36 members including 13 MFS patients. The genomic DNAs from blood leukocytes of the patients and their relatives were isolated and the entire coding region of FBN1 was amplified by PCR. The sequence of FBN1 was dertermined with an ABI 3100 Genetic Analyzer. RESULTS: A previously unreported the missense mutation G214S (caused by a 640 A→G heterozygous change) in FBN1 was identified in the Chinese family. The mutation was associated with the disease phenotype in patients, but not detected in their relatives or in the 100 normal controls. CONCLUSIONS: This is the first report of molecular characterization of FBN1 in the MFS family of Chinese origin. Our results expand the spectrum of FBN1 mutations causing MFS and further confirm the role of FBN1 in the pathogenesis of MFS. Direct sequencing of the mutation in FBN1 may be used for diagnosis of MFS.

Betulin Targets Lipin1/2-Meidated P2X7 Receptor as a Therapeutic Approach to Attenuate Lipid Accumulation and Metaflammation.

The present study focused on the potential mechanism of betulin (BT), a pentacyclic triterpenoid isolated from the bark of white birch (Betula pubescens), against chronic alcohol-induced lipid accumulation and metaflammation. AML-12 and RAW 264.7 cells were administered ethanol (EtOH), lipopolysaccharide (LPS) or BT. Male C57BL/6 mice were fed Lieber-DeCarli liquid diets containing 5% EtOH for 4 weeks, followed by single EtOH gavage on the last day and simultaneous treatment with BT (20 or 50 mg/kg) by oral gavage once per day. In vitro, MTT showed that 0-25 mM EtOH and 0-25 µM BT had no toxic effect on AML-12 cells. BT could regulate sterolregulatory-element-binding protein 1 (SREBP1), lipin1/2, P2X7 receptor (P2X7r) and NOD-like receptor family, pyrin domains-containing protein 3 (NLRP3) expressions again EtOH-stimulation. Oil Red O staining also indicated that BT significantly reduced lipid accumulation in EtOH-stimulated AML-12 cells. Lipin1/2 deficiency indicated that BT might mediate lipin1/2 to regulate SREBP1 and P2X7r expression and further alleviate lipid accumulation and inflammation. In vivo, BT significantly alleviated histopathological changes, reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and triglyceride (TG) levels, and regulated lipin1/2, SREBP1, peroxisome proliferator activated receptor α/γ (PPARα/γ) and PGC-1α expression compared with the EtOH group. BT reduced the secretion of inflammatory factors and blocked the P2X7r-NLRP3 signaling pathway. Collectively, BT attenuated lipid accumulation and metaflammation by regulating the lipin1/2-mediated P2X7r signaling pathway.

Protective role of Siberian onions against toxin-induced liver dysfunction: an insight into health-promoting effects.

Siberian onions (SOs) are delicious wild vegetables. Their taste is most unique, not only like scallions but also like leeks or garlic. They also have a traditional medicinal value for anti-inflammation, anti-oxidation, and anti-pyretic analgesia, particularly facilitating hepatoprotective effects. The current study investigates the potential mechanism of SOs against toxin-induced liver dysfunction. BALB/c mice were administrated with SO or silymarin by oral gavage for one week, followed by injecting carbon tetrachloride (CCl4) to induce hepatic fibrosis. The effect of SO against hepatic fibrosis was evaluated by examining the liver tissue for serum transaminase, oxidative stress, extracellular matrix, histological alterations, cytokine levels, and apoptosis. In vitro, HSC-T6 cells were cultured with the supernatant from Raw 264.7 cells stimulated with lipopolysaccharides, followed by SO extracts or Niclosamide (Signal Transducer and Activator of Transcription 3 (STAT3) inhibitor) at indicated time periods and doses. SO decreased serum transaminase levels and oxidative stress, and regulated the balance of ECM in CCl4-induced mice, including α-SMA, collagen-I and TIMP-1. SO reduced the release of inflammatory factors and regulated apoptosis-associated proteins, which is related to the inhibition of STAT3 phosphorylation. Moreover, SO reduced the positive expressions of α-SMA and NLRP3 by inhibiting STAT3 phosphorylation in activated HSCs. SO could show health-promoting effects for liver dysfunction by alleviating hepatic fibrogenesis, apoptosis and inflammation in the development of hepatic fibrosis potential depending on the STAT3 signaling pathway.

Allium victorialis L. Extracts Promote Activity of FXR to Ameliorate Alcoholic Liver Disease: Targeting Liver Lipid Deposition and Inflammation.

Allium victorialis L. (AVL) is a traditional medicinal plant recorded in the Compendium of Materia Medica (the Ming Dynasty). In general, it is used for hemostasis, analgesia, anti-inflammation, antioxidation, and to especially facilitate hepatoprotective effect. In recent years, it has received more and more attention due to its special nutritional and medicinal value. The present study investigates the effect and potential mechanism of AVL against alcoholic liver disease (ALD). C57BL/6 mice were fed Lieber-DeCarli liquid diet containing 5% ethanol plus a single ethanol gavage (5 g/kg), and followed up with the administration of AVL or silymarin. AML12 cells were stimulated with ethanol and incubated with AVL. AVL significantly reduced serum transaminase and triglycerides in the liver and attenuated histopathological changes caused by ethanol. AVL significantly inhibited SREBP1 and its target genes, regulated lipin 1/2, increased PPARα and its target genes, and decreased PPARγ expression caused by ethanol. In addition, AVL significantly enhanced FXR, LXRs, Sirt1, and AMPK expressions compared with the EtOH group. AVL also inhibited inflammatory factors, NLRP3, and F4/80 and MPO, macrophage and neutrophil markers. In vitro, AVL significantly reduced lipid droplets, lipid metabolism enzymes, and inflammatory factors depending on FXR activation. AVL could ameliorate alcoholic steatohepatitis, lipid deposition and inflammation in ALD by targeting FXR activation.

Crystallization of microporous TiO2 through photochemical deposition of Pt for photocatalytic degradation of volatile organic compounds.

The photocatalytic mineralization efficiency of volatile organic compounds (VOCs) is determined by adsorption of reactants, separation of charge carriers, and reaction activity of catalyst surface. Herein, we provide a strategy to synthesize a novel catalyst, namely, PhPt-Micro, which is characterized by high adsorption ability, charge separation efficiency, and surface reaction activity. Toluene was chosen as the model VOC. The effects of photochemical deposition of Pt on the physical properties of microporous amorphous TiO2 (Micro) and toluene mineralization were studied using N2 adsorption/desorption, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, GC-flame ionization detection, and surface photovoltage spectroscopy (SPS) analyses. After photochemical treatment, the structure of Micro was optimized, and Pt nanoparticles were successfully deposited at the outlet of electrons on the catalyst surface. SPS result proved that the optimized structure enhanced the separation efficiency of charge carriers and the migration of photo-generated electrons to the PhPt-Micro surface. The quasi-equilibrium adsorption amount of toluene over PhPt-Micro was two times higher than that with commercial nano TiO2 (P25). The micropores concentrated toluene on the catalyst surface and hindered intermediate desorption. The mineralization efficiency of toluene over PhPt-Micro was 2.4 and 5.9 times higher than those over Micro and P25, respectively.

[Development and application of geographic information system of Aedes vector in Chaozhou city, Guangdong province].

OBJECTIVE: To explore the spatial distribution character of dengue fever and the change of Aedes' population, so as to provide macroscopical decision-making evidences of prevention and supervision on dengue fever. METHODS: (1) Collecting data on morbidity of dengue and supervision on vector's population in the corresponding period. (2) Drawing digitized map of Chaozhou in scale of 1:50,000, including elements of boundary, residential areas, road and traffic, altitude, water systems etc. (3) Measuring the latitude and longitude of center position of surveillance safes on the scene. (4) Processing spatial analysis by the ArcGIS 8.5 software. RESULTS: Distribution of Aedes showed spatial cluster in Chaozhou, while its density was related to the distance to the watersides. The closer to the watersides, the higher the density was. Map on spatial distribution showed that although the Aedes epidemic situation changed yearly, but primarily be kept in high, middle, low regions. Cross-validation effects of the distribution maps were satisfactory. CONCLUSION: Geographic information system was promising in analyzing data on dengue fever, and better than other routine research methods.