Paeonol attenuates nonalcoholic steatohepatitis by regulating intestinal flora and AhR/NLRP3/Caspase-1 metabolic pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Non-alcoholic steatohepatitis (NASH) is a common metabolic liver injury disease that is closely associated with obesity and metabolic disorders. Paeonol, an active ingredient found in Moutan Cortex, a traditional Chinese medicine which exhibits significant therapeutic effect on liver protection, has shown promising effects in treating liver diseases, particularly NASH. However, the specific intervention mechanism of paeonol on NASH is still unknown. AIM OF THE STUDY: Our objective is to elucidate the pharmacological mechanism of paeonol in intervening NASH at the in vivo level, focusing on the impact on intestinal flora, tryptophan-related targeted metabolome, and related Aryl hydrocarbon receptor (AhR) pathways. MATERIALS AND METHODS: Here, we explored the intervention effect of paeonol on NASH by utilizing the NASH mouse model. The Illumina highthroughput sequencing technology was preformed to determine the differences of gut microbiota of model and paeonol treatment group. The concentration of Indoleacetic acid is determined by ELISA. The intervention effect of NASH mouse and AhR/NLRP3/Caspase-1 metabolic pathway is analyzed by HE staining, oil red O staining, Immunohistochemistry, Immunofluorescence, Western blot and qRT-PCR assays. Fecal microbiota transplantation experiment also was performed to verify the intervention effect of paeonol on NASH by affecting gut microbiota. RESULTS: Firstly, we discovered that paeonol effectively reduced liver pathology and blood lipid levels in NASH mice, thereby intervening in the progression of NASH. Subsequently, through 16S meta-analysis, we identified that paeonol can effectively regulate the composition of intestinal flora in NASH mice, transforming it to resemble that of normal mice. Specifically, paeonol decreased the abundance of certain Gram-negative tryptophan-metabolizing bacteria. Moreover, we discovered that paeonol significantly increased the levels of metabolites Indoleacetic acid, subsequently enhancing the expression of AhR-related pathway proteins. This led to the inhibition of the NOD-like receptor protein 3 (NLRP3) inflammasome production and inflammation generation in NASH. Lastly, we verified the efficacy of paeonol in intervening NASH by conducting fecal microbiota transplantation experiments, which confirmed its role in promoting the AhR/NLRP3/cysteinyl aspartate specific proteinase (Caspase-1) pathway. CONCLUSIONS: Our findings suggest that paeonol can increase the production of Indoleacetic acid by regulating the gut flora, and promote the AhR/NLRP3/Caspase-1 metabolic pathway to intervene NASH.

The interaction between autophagy and the epithelial-mesenchymal transition mediated by NICD/ULK1 is involved in the formation of diabetic cataracts.

BACKGROUND: Cataracts are the leading cause of blindness and a common ocular complication of diabetes. The epithelial-mesenchymal transition (EMT) of lens epithelial cells (LECs) and altered autophagic activity occur during the development of diabetic cataracts. The disturbed interaction of autophagy with EMT in LECs stimulated by high glucose levels may participate in cataract formation. METHODS: A rat diabetic cataract model induced by streptozotocin (STZ) and human lens epithelial cells (HLE-B3) stimulated with a high glucose concentration were employed in the study. These models were treated with rapamycin (an inhibitor of mammalian target of rapamycin (mTOR)), and N-(N-[3,5-difluorophenacetyl]-1-alanyl)-S-phenylglycine t-butyl ester (DAPT, an inhibitor of γ-secretase) alone or in combination. Lens opacity was observed and photographed under a slit-lamp microscope. Histological changes in paraffin sections of lenses were detected under a light microscope after hematoxylin and eosin staining. Alterations of autophagosomes in LECs were counted and evaluated under a transmission electron microscope. The expression levels of proteins involved in the EMT, autophagy, and the signaling pathways in LECs were measured using Western blotting and immunofluorescence staining. Cell migration was determined by performing transwell and scratch wound assays. Coimmunoprecipitation (Co-IP) was performed to verify protein-protein interactions. Proteins were overexpressed in transfected cells to confirm their roles in the signaling pathways of interest. RESULTS: In LECs, a high glucose concentration induces the EMT by activating Jagged1/Notch1/Notch intracellular domain (NICD)/Snail signaling and inhibits autophagy through the AKT/mTOR/unc 51-like kinase 1 (ULK1) signaling pathway in vivo and in vitro, resulting in diabetic cataracts. Enhanced autophagic activity induced by rapamycin suppressed the EMT by inducing Notch1 degradation by SQSTM1/p62 and microtubule-associated protein light chain 3 (LC3) in LECs, while inhibition of the Notch signaling pathway with DAPT not only prevented the EMT but also activated autophagy by decreasing the levels of NICD, which bound to ULK1, phosphorylated it, and then inhibited the initiation of autophagy. CONCLUSIONS: We describe a new interaction of autophagy and the EMT involving NICD/ULK1 signaling, which mediates crosstalk between these two important events in the formation of diabetic cataracts. Activating autophagy and suppressing the EMT mutually promote each other, revealing a potential target and strategy for the prevention of diabetic cataracts.

Correlation between neutrophil-to-lymphocyte ratio and clinical manifestations and complications of retinitis pigmentosa.

PURPOSE: The role of inflammation in retinitis pigmentosa (RP) has been receiving additional attention. However, the association between inflammation and the clinical manifestations and complications of RP is still unclear. This study aimed to evaluate the neutrophil-to-lymphocyte ratio (NLR) of RP complicated with cataract and explore the correlations between the NLR and specific clinical features of RP. METHODS: This retrospective study included 79 RP patients complicated with cataract (125 eyes) and 63 age- and sex-matched patients (63 eyes) with age-related cataract (ARC). Patients' ocular examination results were collected and complete blood count results were used to calculate NLRs. The correlations between the NLR of RP patients and the parameters of ocular examinations were analysed. RESULTS: The NLRs of RP patients with cataracts were significantly higher than those of ARC (1.93 ± 0.83 versus 1.65 ± 0.59, p = 0.029). The NLRs increased with the severity of posterior subcapsular cataract (PSC), zonular deficiency, poor preoperative best-corrected visual acuity (LogMAR>1), and visual field defects. Analysis of receiver operating characteristic curves suggested that NLR > 1.36 could predict higher degrees (PSC area >3%, >P1) of PSC (p = 0.002, 95% CI, 0.672-0.934), and that NLR > 2.12 could predict zonular weakness (p = 0.002, 95% CI, 0.665-0.928) in RP. CONCLUSION: The NLRs in RP patients with cataract are not only higher but also associated with several clinical manifestations of RP. The NLR can be a predictive biomarker of higher degrees of PSC (>P1) and zonular weakness in RP before cataract surgery. These results suggest that systemic inflammation may play a role in the pathogenesis of RP.

Infrared Spectroscopy of Solvation in the TaO2+ Hydrolysis Reaction.

The solvent effect of the TaO2+ reaction with water molecules in the gas phase is examined. Stoichiometric TaO2(H2O)n+ cations are generated by the laser vaporization of a tantalum metal target in the pulsed supersonic expansion of H2O/He mixed gas. The infrared photodissociation spectra of TaO2(H2O)n+ cations are measured using the argon-tagging technology in the 2800-3850 cm-1 region. Density functional theory calculations are carried out to identify the observed infrared bands and elucidate the reaction mechanism. In the TaO2+ reaction with one H2O molecule, both the hydrated adduct H2O-TaO2+ and dihydroxide TaO(OH)2+ are generated. The coexistence of tetrahydroxide Ta(OH)4+ and hydrated dihydroxide H2O-TaO(OH)2+ is seen when the second H2O molecule is involved. However, only the hydrated H2O-Ta(OH)4+ product is obtained in the TaO2 reaction with three H2O molecules. Theoretical calculations indicate that in the reaction, the formation of a six-membered cyclic transition state through the hydrogen bond lowers the energy barrier significantly, which promotes the transfer of the hydrogen of hydrated adducts to generate di- and tetrahydroxides.

Sensitive quantitation of ESR1 mutations in cell-free DNA from breast cancer patients using base-specific invasive reaction assisted qPCR.

Acquired estrogen receptor 1 (ESR1) mutation is being promoted as a key mechanism of resistance to endocrine therapies in breast cancers. It is significative to monitor ESR1 mutations in real time, which provide an opportunity to alter therapy as these mutations emerge. Previous assays based on next-generation sequencing (NGS) and digital PCR (dPCR) usually due to high costs and complicated workflows hampered their clinical adoption in general medical institutions. Here, we proposed a new strategy using base-specific invasive reaction assisted qPCR measure for ESR1 mutations in cfDNA. Two pivotal steps involved in this strategy are target-specific signal generation and the quantification without adding any internal reference or making standard calibration curves. The strategy enabled a high specificity of 0.1% (better than traditional NGS-based method) and a minimum sensitivity of 0.1 copies µL-1. As validation, with the strategy, cfDNA from endocrine therapy-resistant breast cancers and untreated ones were successfully analyzed (20% mutation rate (2/10) with mutation abundance of 0.54-1.65% vs. 0% mutation rate (0/5)). By virtue of cost-effective, highly flexible and precise, the strategy could be readily implemented in general laboratory, showing promising application perspectives in analysis of other types of mutations.

Infrared photodissociation spectroscopic investigation on VO+ and NbO+ hydrolysis catalyzed by water molecules.

We investigate the hydrolysis of vanadium/niobium monoxide cation (VO+/NbO+) with water molecules in the gas phase. Cationic argon-tagged intermediates, TMO(H2O)nArm+ (TM = V, Nb; n = 1-2, m = 1-2), are prepared for examination using infrared photodissociation spectroscopy. The structures of the intermediates are elucidated by comparing them with simulated spectra. VO(H2O)Ar+ or NbO(H2O)Ar+ (for n = 1) is intrinsically a hydrated adduct, represented by H2O-VOAr+ or H2O-NbOAr+, rather than a dihydroxide, V(OH)2Ar+ or Nb(OH)2Ar+. However, when a second H2O molecule is involved (for n = 2), the dihydroxide V(OH)2(H2O)Ar+ and trihydroxide HNb(OH)3Ar+ are formed. In this process, the six-member cyclic transition state formed by two H2O molecules markedly reduces the hydrogen transfer energy barrier based on our calculations. This work provides more precise experimental evidence for the Grotthuss-like mechanism proposed in the studies of hydrolysis and tautomerization reactions.

LncRNA MALAT1 Regulates miR-144-3p to Facilitate Epithelial-Mesenchymal Transition of Lens Epithelial Cells via the ROS/NRF2/Notch1/Snail Pathway.

Diabetic cataract is a common complication of diabetes. The epithelial-mesenchymal transition (EMT) of lens epithelial cells (LECs) is a key event in the development of diabetic cataracts. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been reported to be highly expressed in different tissues of diabetic patients. This study is aimed at investigating the function and mechanism of MALAT1 in the regulation of EMT in human LECs under high glucose conditions. MALAT1, α-smooth muscle actin (α-SMA), fibronectin (FN), and nuclear factor erythroid-derived 2-like 2 (NRF2) were highly expressed in the LECs of diabetic cataract patients and in the human LECs under high glucose conditions; meanwhile, the decreased expressions of E-cadherin and zonula occludens 1 (ZO-1) were detected. Knockdown of MALAT1 could significantly reduce ROS, prevent EMT, arrest S phase cell cycle, and suppress the expression of total NRF2 and its nucleus translocation in LECs. Furthermore, after NRF2 was knocked down, total NRF2, α-SMA, and FN in cells, and NRF2, Notch intracellular domain (NICD), and Snail were decreased in the nucleus. Using bioinformatics methods, we predicted that MALAT1 and NRF2 shared the same microRNA-144-3p (miR-144-3p) combining site. Luciferase reporter coupled with qRT-PCR assays revealed that miR-144-3p was a target of MALAT1, which was confirmed to downregulate miR-144-3p in the LECs. In addition, after transfection of miR-144-3p mimics or inhibitor, western blot assay demonstrated that miR-144-3p negatively regulated the expression of total NRF2, α-SMA, and FN in cells, and NRF2, NICD, and Snail in the nucleus without affecting Kelch-like ECH-associated protein 1 (KEAP1). Finally, we confirmed that transfection of shMALAT1 inhibited NRF2 expression, and its mediated EMT could be rescued by miR-144-3p inhibitor; transfection of pcDNA3.1-MALAT1 promoted NRF2 expression, and its mediated EMT could be reversed by miR-144-3p inhibitor. In summary, we demonstrate that MALAT1 regulates miR-144-3p to facilitate EMT of LECs via the ROS/NRF2/Notch1/Snail pathway.

Binary Gas Analyzer Based on a Single Gold Nanoparticle Photothermal Response.

Although thermal conductivity gas analyzers are ubiquitous in industry, shrinking the sensing unit to a microscopic scale is rarely achieved. Since heat transfer between a metal nanoparticle and its ambient gas changes the temperature, refractive index, and density of the gaseous surrounding, one may tackle the problem using a single nanoparticle's photothermal effect. Upon heating by a 532 nm laser, a single gold nanoparticle transfers heat to the surrounding gas environment, which results in a change in the photothermal polarization of a 633 nm probe laser. The amplitude of the photothermal signal correlates directly with the concentration of binary gas mixture. In He/Ar, He/N2, He/air, and H2/Ar binary gas mixtures, the signal is linearly proportional to the He and H2 molar concentrations up to about 10%. The photothermal response comes from the microscopic gaseous environment of a single gold nanoparticle, extending from the nanoparticle roughly to the length of the gas molecule's mean free path. This study points to a way of sensing binary gas composition in a microscopic volume using a single metal nanoparticle.

Activation of autophagy inhibits epithelial to mesenchymal transition process of human lens epithelial cells induced by high glucose conditions.

Subcapsular cataracts are common phenotype of diabetic cataracts, and abnormal lens epithelial cells (LECs) under the lens capsules have been considered to involve in the pathogenesis. Our previous studies have shown that the epithelial to mesenchymal transition (EMT), which is responsible for the LECs to lose their original polarity and tight junctions, occurs in a diabetic cataract mouse model. Autophagy is known to function in the EMT process in multiple tissues. However, the relationship between autophagy and EMT process in LECs has not yet been fully demonstrated. We found that high glucose retreatment reducing expression level of E-cadherin, an epithelial marker, but increasing that of α-smooth muscle actin (α-SMA), a mesenchymal marker, by Western blot and immunoflurence staining assays, and increased the cell migration by Transwell assay in human lens epithelial cell line HLE-B3. High glucose retreatment also led to impairment of autophagy, representing by downregulation of Beclin, LC3II/LC3I, and reducing the number of autophagosomes. Activation of autophagy by rapamycin could prevent high glucose-induced EMT. In addition, the levels of p62 and Snail were increased in high glucose-treated HLE-B3 cells, and their interactions were demonstrated by co-immunoprecipitation and immunoflurence staining, but all these changes were attenuated by application of rapamycin. These findings delineated a novel autophagy-mediated mechanism, p62 might mediate Snail underlying high glucose-induced EMT in LECs, suggesting a potential therapeutic approach for diabetic cataract by regulating autophagy.

Audible Sound from Vibrating Sessile Droplets for Monitoring Chemicals and Reactions in Liquid.

To reduce environmental impact and sensor footprint, researchers need cost-effective and small-size surface tension and viscosity measurement devices. New measurement principles are needed for such sensors. We demonstrate that a sessile droplet's mechanical vibration can be transformed to audible sound, by recording the ultrasonic Doppler frequency shift in the form of an acoustic signal. The recorded sound wave reveals a droplet's surface tension and its viscosity, through its frequency spectrum and attenuation rate of the signal, respectively. Based on such sensors, two chemical measurements inside sessile droplets are shown: (I) titration of a Ni2+ and Co2+ mixture with a surface-active indicator (using surface tension) and (II) measurement of the molecular weight of a polymer in solution (using viscosity). Unlike the commercial technique, our ultrasound-based sensor is cost-effective in terms of equipment price and sample volume.

Infrared Photodissociation Spectroscopy of Mass-Selected Cu2O2(CO)n+ Clusters in the Gas Phase.

Stoichiometric Cu2O2(CO)n+ (n = 3-7) clusters were generated via a laser vaporization supersonic cluster source in the gas phase and identified by infrared photodissociation spectroscopy in the C-O stretching region. The infrared spectra were interpreted, and the cluster structures were determined by density functional calculations. The ground states of the Cu2O2(CO)n+ complexes were formed by a dicopper superoxide carbonyl with [(OC)xCuOOCu(CO)y]+ (x + y = n) structures in which the CO ligands coordinate a zigzag Cu(OO)Cu+ core. The structural characterization for the Cu(OO)Cu+ core-based clusters is crucial in order to correctly understand the associated reactions catalyzed by metal clusters.

Influencing Mechanisms of Urban Heat Island on Respiratory Diseases.

BACKGROUND: Urban heat island (UHI) is being intensified with the progress of urbanization. Meanwhile, respiratory diseases caused by high temperature become common. This study explores the influences of UHI on respiratory diseases (J00-J99) and the evolutionary characteristics of the spatial pattern of such influences. METHODS: The pattern-process-function and the influencing mechanism of UHI on respiratory diseases were evaluated through landscape pattern indexes from 1992 to 2018 in Tianjin, China. The basis was on data from Landsat TM/OLI/TIRS remote-sensing images, meteorological stations, and mortality of respiratory diseases. RESULTS: The fluctuating influence of UHI on the respiratory diseases in Tianjin has increased from 1992 to 2018, showing a significant phase-based characteristic. During 2011-2018, the influence has soared greatly, and mortality risk has increased by 101%, and the influenced area has reached 349 km2. Furthermore, the regional space clustered, and the influenced patches are in irregular shape, and the highly influenced area is enlarged. Moreover, the indexes of the landscape level of the influenced areas all decrease. The patches at all levels are fragmented and distributed discontinuously. Spatially, the influenced areas gradually extend from the urban center to the suburbs. CONCLUSION: UHI causes a higher mortality of respiratory diseases because it increases daily average air temperature in summer. With respect to landscape pattern, the influenced areas at low level is highly interconnected and relatively concentrated, whereas the influenced area at high level is distributed in clusters. In general, the influenced area is fragmented and discontinuously distributed in urban center.

External validity of a prognostic nomogram for locoregionally advanced nasopharyngeal carcinoma based on the 8th edition of the AJCC/UICC staging system: a retrospective cohort study.

BACKGROUND: The tumor-node-metastasis (TNM) staging system does not perform well for guiding individualized induction or adjuvant chemotherapy for patients with locoregionally advanced nasopharyngeal carcinoma (NPC). We attempted to externally validate the Pan's nomogram, developed based on the 8th edition of the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) staging system, for patients with locoregionally advanced disease. In addition, we investigated the reliability of Pan's nomogram for selection of participants in future clinical trials. METHODS: This study included 535 patients with locoregionally advanced NPC who were treated between March 2007 and January 2012. The 5-year overall survival (OS) rates were calculated using the Kaplan-Meier method and compared with predicted outcomes. The calibration was tested using calibration plots and the Hosmer-Lemeshow test. Discrimination ability, which was assessed using the concordance index, as compared with other predictors. RESULTS: Pan's nomogram was observed to underestimate the 5-year OS of the entire cohort by 8.65% [95% confidence interval (CI) - 9.70 to - 7.60%, P < 0.001] and underestimated the 5-year OS of each risk group. The differences between the predicted and observed 5-year OS rates were smallest among low-risk patients (< 135 points calculated using Pan's nomogram; which predicted minus observed OS, - 6.41%, 95% CI - 6.75 to - 6.07%, P < 0.001) and were largest among high-risk patients (≥ 160 points) (- 13.56%, 95% CI - 15.48 to - 11.63%, P < 0.001). The Hosmer-Lemeshow test suggested that the predicted and observed 5-year OS rates had no ideal relationship (P < 0.001). Pan's nomogram had better discriminatory ability compared with the levels of Epstein-Barr virus DNA acid (EBV DNA) and the 7th or 8th AJCC/UICC staging system, although not better compared with the combination of EBV DNA and the 8th staging system. Additionally, Pan's nomogram was marginally inferior to our predictive model, which included the 8th AJCC/UICC N-classification, age, gross primary tumor volume, lactate dehydrogenase, and body mass index. CONCLUSIONS: Pan's nomogram underestimated the 5-year OS of patients with locoregionally advanced NPC at our cancer center, and may not be a precise tool for selecting participants for clinical trials.

The total number of lymph nodes harvested from pathological T3N0 rectal cancer patients: Prognostic significance and potential indication for postoperative radiotherapy.

BACKGROUND: Lymph node status is important in staging colorectal cancer. The use of combination treatment for pathological T3N0 (pT3N0) rectal cancer patients has been controversial. We aimed to explore the prognostic significance of the total number of lymph nodes harvested from pT3N0 rectal cancer patients. METHODS: Between June 2004 and November 2011, 289 pT3N0 rectal cancer patients who received total mesorectal excision (TME) with or without postoperative chemotherapy were retrospectively reviewed. The main independent variable was the total number of harvested lymph nodes, and the endpoints included local recurrence-free survival (LRFS), disease-free survival (DFS), and overall survival (OS). RESULTS: The patients had a median of 13 lymph nodes harvested. When compared with patients who had < 12 lymph nodes harvested, patients who had ≥12 lymph nodes harvested had higher 5-year LRFS (84.7% vs. 98.0%, P < 0.001), DFS (71.4% vs. 86.8%, P < 0.001), and OS (77.6% vs. 94.9%, P < 0.001) rates. Multivariate analysis demonstrated that the patients who had ≥12 lymph nodes harvested had a significantly lower risks of local relapse (hazard ratio [HR], 0.099; P < 0.001), treatment failure (HR: 0.291; P < 0.001), and death (HR: 0.231; P < 0.001) when compared with patients who had <12 lymph nodes harvested. CONCLUSIONS: The number of lymph nodes harvested was independently associated with local relapse, treatment failure, and OS rates in pT3N0 rectal cancer patients who received initial TME with or without postoperative chemotherapy. Postoperative radiotherapy should not be omitted for pT3N0 rectal cancer patients who had <12 lymph nodes harvested.

Nanometer-Thick Newton Black Film for Selective Formaldehyde Gas Detection.

A fluorescence spectroscopic assay using Newton black film (NBF) for sensitive and selective detection of gaseous formaldehyde at room temperature is reported. The method relies on the Hantzsch reaction of formaldehyde with ammonium citrate and acetylacetone, plus a combination of the large surface area-to-volume ratio (5 × 108 m-1) and efficient uptake of gas by the nanometer-thick aqueous core of NBF. The assay has a limit of detection (LOD) of 4 ppb, a linear signal-to-concentration correlation up to 300 ppb of HCHO gas in the air, and a nonlinear monotonic increasing correlation in the range of 300 ppb to 1.2 ppm. It is unaffected by relevant analytes such as acetaldehyde, benzaldehyde, acetone, and propionaldehyde. We also demonstrate the sensing of formaldehyde outgassing from a plywood sample using this method and the results agree with the factory specifications.

Controlled fluorescence quenching by antibody-conjugated graphene oxide to measure tau protein.

We report an ultrasensitive immunoassay for tau protein-a key marker of Alzheimer's disease. This sensing platform relies on graphene oxide (GO) surfaces conjugated with anti-human tau antibody to provide quantitative binding sites for the tau protein. The GO quenches standard fluorescein isothiocyanate labelled tau (tau-FITC) when tau protein and tau-FITC are both present and compete for the binding sites. This change in fluorescence signal can be used to quantitate tau protein. In contrast with traditional enzyme-linked immunosorbent assay (ELISA), our method does not require enzyme-linked secondary antibodies for protein recognition nor does it require an enzyme substrate for optical signal generation. This requires fewer reagents and has less systematic error than the antigen-antibody recognition steps in ELISA. Our method has a tau protein detection limit of 0.14 pmol ml-1 in buffer. This approach could be developed into a promising biosensor for the detection of tau protein and may be useful in the clinical diagnosis of tau-induced neurodegeneration syndromes.

Sensing Parts per Million Level Ammonia and Parts per Billion Level Acetic Acid in the Gas Phase by Common Black Film with a Fluorescent pH Probe.

Relying on the nanometer-thick water core and large surface area-to-volume ratio (∼2 × 108 m-1) of common black film (CBF), we are able to use a pH-sensitive dye (carboxy-seminaphthorhodafluor-1, SNARF-1) to detect ammonia and acetic acid gas adsorption into the CBF, with the limit of detection reaching 0.8 ppm for NH3 gas and 3 ppb for CH3COOH gas in the air. Data analysis reveals that fluorescence signal change is linearly proportional to the gas concentration up to 15 ppm and 65 ppb for NH3 and CH3COOH, respectively.

Identification and Characterization of Diacylglycerol Acyltransferase from Oleaginous Fungus Mucor circinelloides.

Acyl-CoA:diacylglycerol acyltransferase (DGAT) is a pivotal regulator of triacylglycerol (TAG) synthesis. The oleaginous fungus Mucor circinelloides has four putative DGATs: McDGAT1A, McDGAT1B, McDGAT2A, and McDGAT2B, classified into the DGAT1 and DGAT2 subfamilies, respectively. To identify and characterize DGATs in M. circinelloides, these four genes were expressed in Saccharomyces cerevisiae H1246 (TAG-deficient quadruple mutant), individually. TAG biosynthesis was restored only by the expression of McDGAT2B, and TAG content was significantly higher in the mutants with McDGAT2B expression than in a S. cerevisiae mutant with endogenous DGA1 expression. McDGAT2B prefers saturated fatty acids to monounsaturated fatty acids and has an obvious preference for C18:3 (ω-6) according to the results of substrate preference experiments. Furthermore, only the mRNA expression pattern of McDGAT2B correlated with TAG biosynthesis during a fermentation process. Our experiments strongly indicate that McDGAT2B is crucial for TAG accumulation, suggesting that it may be an essential target for metabolic engineering aimed at increasing lipid content of M. circinelloides.

Microsphere Assisted Super-resolution Optical Imaging of Plasmonic Interaction between Gold Nanoparticles.

Conventional far-field microscopy cannot directly resolve the sub-diffraction spatial distribution of localized surface plasmons in metal nanostructures. Using BaTiO3 microspheres as far-field superlenses by collecting the near-field signal, we can map the origin of enhanced two-photon photoluminescence signal from the gap region of gold nanosphere dimers and gold nanorod dimers beyond the diffraction limit, on a conventional far-field microscope. As the angle θ between dimer's structural axis and laser polarisation changes, photoluminescence intensity varies with a cos4θ function, which agrees quantitatively with numerical simulations. An optical resolution of about λ/7 (λ: two-photon luminescence central wavelength) is demonstrated at dimer's gap region.

Validation and comparison of the 7th and 8th edition of AJCC staging systems for non-metastatic nasopharyngeal carcinoma, and proposed staging systems from Hong Kong, Guangzhou, and Guangxi.

OBJECTIVES: We aimed to validate and compare the 7th and 8th edition of AJCC staging systems for non-metastatic nasopharyngeal carcinoma, and proposed staging systems from Hong Kong, Guangzhou, and Guangxi. MATERIALS AND METHODS: We retrospectively included 899 patients treated between November 5, 2002 and May 27, 2010. Separation and discrimination of each staging system in overall survival were primarily compared. RESULTS: Compared with the 7th AJCC, the 8th AJCC and all proposed staging systems well separated across T-classification. T-classification from Guangzhou seemed to perform best in discrimination (C-index 0.6454), followed by the 8th AJCC (0.6451), the 7th AJCC (0.6386), Hong Kong (0.6376) and Guangxi (0.5889). For N-classification, no staging systems improved the weakness of the 7th AJCC in separating N2 and N1, except that suggestion from Guangzhou showed higher potential (P=0.096). Besides, N-classification from Guangzhou had a C-index of 0.6444, larger than that of the 8th AJCC (0.6235), the 7th AJCC (0.6179), Hong Kong (0.6175) and Guangxi (0.6175). Accordingly, stage group of staging system from Guangzhou showed higher discrimination (C-index 0.6839), compared with the 8th AJCC (0.6791), the 7th AJCC (0.6766), Hong Kong (0.6765) and Guangxi (0.6688), despite that stage I and II remained inseparable (P=0.322). CONCLUSIONS: The 8th AJCC staging system appeared to be better than the 7th AJCC. But the proposed staging system from Guangzhou was more likely to improve the separation and discrimination abilities.