| 1. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
- Zhang, Huai, et al.
(författare)
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A global survey on the use of the international classification of diseases codes for metabolic dysfunction-associated fatty liver disease.
- 2024
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Ingår i: Hepatology international. - 1936-0541.
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Tidskriftsartikel (refereegranskat)abstract
- With the implementation of the 11th edition of the International Classification of Diseases (ICD-11) and the publication of the metabolic dysfunction-associated fatty liver disease (MAFLD) nomenclature in 2020, it is important to establish consensus for the coding of MAFLD in ICD-11. This will inform subsequent revisions of ICD-11.Using the Qualtrics XM and WJX platforms, questionnaires were sent online to MAFLD-ICD-11 coding collaborators, authors of papers, and relevant association members.A total of 890 international experts in various fields from 61 countries responded to the survey. We also achieved full coverage of provincial-level administrative regions in China. 77.1% of respondents agreed that MAFLD should be represented in ICD-11 by updating NAFLD, with no significant regional differences (77.3% in Asia and 76.6% in non-Asia, p=0.819). Over 80% of respondents agreed or somewhat agreed with the need to assign specific codes for progressive stages of MAFLD (i.e. steatohepatitis) (92.2%), MAFLD combined with comorbidities (84.1%), or MAFLD subtypes (i.e., lean, overweight/obese, and diabetic) (86.1%).This global survey by a collaborative panel of clinical, coding, health management and policy experts, indicates agreement that MAFLD should be coded in ICD-11. The data serves as a foundation for corresponding adjustments in the ICD-11 revision.
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| 3. |
- Zhang, Li, et al.
(författare)
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Characterization of anti-BCG benz[α]anthraquinones and new siderophores from a Xinjiang desert-isolated rare actinomycete Nocardia sp. XJ31
- 2020
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Ingår i: Applied Microbiology and Biotechnology. - : Springer Science and Business Media LLC. - 0175-7598 .- 1432-0614. ; 104:19, s. 8267-8278
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Tidskriftsartikel (refereegranskat)abstract
- The current global demand for novel anti-TB drugs has drawn urgent attention on the discovery of natural product compounds with anti-TB activity. Lots of efforts have emphasized on environmental samples from unexplored or underexplored natural habits and identified numerous rare actinomycete taxa producing structurally diverse bioactive natural products. Herein, we report a survey of the rare actinobacteria diversity in Xinjiang region together with the discovery of anti-TB active natural products from these strains. We have collected 17 soil samples at different sites with different environmental conditions, from which 39 rare actinobacteria were identified by using a selective isolation strategy with 5 media variations. Among those isolated strains, XJ31 was identified as a new Nocardia sp. based on 16S rRNA gene analysis. Through one strain-many compounds (OSMAC) strategy combined with anti-Bacillus Calmette-Guérin bioassay-guided isolation, two groups of compounds were identified. They were twelve siderophores (nocardimicins, 1-12) and two anthraquinones (brasiliquinones, 13 and 14) and ten of them were identified as new compounds. The structures of the purified compounds were elucidated using HR-ESI-MS, 1D NMR, and 2D NMR techniques. The anti-TB bioassays revealed that the two benz[α]anthraquinones have potent activity against BCG (MICs = 25 μM), which can be used as a promising start point for further anti-TB drug development.
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| 4. |
- Long, Chang, et al.
(författare)
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Regulating reconstruction of oxide-derived Cu for electrochemical CO2 reduction toward n-propanol
- 2023
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Ingår i: Science Advances. - 2375-2548. ; 9:43
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Tidskriftsartikel (refereegranskat)abstract
- Oxide-derived copper (OD-Cu) is the most efficient and likely practical electrocatalyst for CO2 reduction toward multicarbon products. However, the inevitable but poorly understood reconstruction from the pristine state to the working state of OD-Cu under strong reduction conditions largely hinders the rational construction of catalysts toward multicarbon products, especially C-3 products like n-propanol. Here, we simulate the reconstruction of CuO and Cu2O into their derived Cu by molecular dynamics, revealing that CuO-derived Cu (CuOD-Cu) intrinsically has a richer population of undercoordinated Cu sites and higher surficial Cu atom density than the counterpart Cu2O-derived Cu (Cu2OD-Cu) because of the vigorous oxygen removal. In situ spectroscopes disclose that the coordination number of CuOD-Cu is considerably lower than that of Cu2OD-Cu, enabling the fast kinetics of CO2 reaction and strengthened binding of *C-2 intermediate(s). Benefiting from the rich undercoordinated Cu sites, CuOD-Cu achieves remarkable n-propanol faradaic efficiency up to similar to 17.9%, whereas the Cu2OD-Cu dominantly generates formate.
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| 5. |
- Su, Changqing, et al.
(författare)
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Gene-Viral Cancer Therapy Using Dual-Regulated Oncolytic Adenovirus with Antiangiogenesis Gene for Increased Efficacy.
- 2008
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Ingår i: Molecular Cancer Research. - 1557-3125. ; 6, s. 568-575
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Tidskriftsartikel (refereegranskat)abstract
- Conditionally replicative adenovirus (CRAD) represents a promising approach for cancer therapy. Several CRADs controlled by the human telomerase reverse transcriptase promoter have been developed. However, because of their replicative capacity, the importance of cancer specificity for CRADs needs to be further emphasized. In this study, we have developed a novel dual-regulated CRAD, CNHK500-mE, which has its E1a and E1b gene controlled by the human telomerase reverse transcriptase promoter and the hypoxia response element, respectively. It also carries a mouse endostatin expression cassette controlled by the cytomegalovirus promoter. These properties allow for increased cancer cell targeting specificity and decreased adverse side effects. We showed that CNHK500-mE preferentially replicated in cancer cells. Compared with a replication-defective vector carrying the same endostatin expression cassette, CNHK500-mE-mediated transgene expression level was markedly increased via viral replication within cancer cells. In the nasopharyngeal tumor xenograft model, CNHK500-mE injection resulted in antitumor efficacy at day 7 after therapy. Three weeks later, it led to significant inhibition of xenograft tumor growth due to the combined effects of viral oncolytic therapy and antiangiogenesis gene therapy. Pathologic examination showed that most cancer cells were positive for adenoviral capsid protein and for apoptotic terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling in the CNHK500-mE-treated tumor tissues, and the microvessels in these tumor tissues were diminished in quantity and abnormal in morphology. These results suggest that, as a potential cancer therapeutic agent, the CNHK500-mE is endowed with higher specificity to cancer cells and low cytotoxicity to normal cells. (Mol Cancer Res 2008;6(4):OF1-8).
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| 6. |
- Cai, Jing, et al.
(författare)
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Influence of organic aerosol molecular composition on particle absorptive properties in autumn Beijing
- 2022
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Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 22:2, s. 1251-1269
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Tidskriftsartikel (refereegranskat)abstract
- Organic aerosol (OA) is a major component of fine particulate matter (PM), affecting air quality, human health, and the climate. The absorptive and reflective behavior of OA components contributes to determining particle optical properties and thus their effects on the radiative budget of the troposphere. There is limited knowledge on the influence of the molecular composition of OA on particle optical properties in the polluted urban environment. In this study, we characterized the molecular composition of oxygenated OA collected on filter samples in the autumn of 2018 in Beijing, China, with a filter inlet for gases and aerosols coupled to a high-resolution time-of-flight chemical ionization mass spectrometer (FIGAERO–CIMS). Three haze episodes occurred during our sampling period with daily maximum concentrations of OA of 50, 30, and 55 µg m−3. We found that the signal intensities of dicarboxylic acids and sulfur-containing compounds increased during the two more intense haze episodes, while the relative contributions of wood-burning markers and other aromatic compounds were enhanced during the cleaner periods. We further assessed the optical properties of oxygenated OA components by combining detailed chemical composition measurements with collocated particle light absorption measurements. We show that light absorption enhancement (Eabs) of black carbon (BC) was mostly related to more oxygenated OA (e.g., dicarboxylic acids), likely formed in aqueous-phase reactions during the intense haze periods with higher relative humidity, and speculate that they might contribute to lensing effects. Aromatics and nitro-aromatics (e.g., nitrocatechol and its derivatives) were mostly related to a high light absorption coefficient (babs) consistent with light-absorbing (brown) carbon (BrC). Our results provide information on oxygenated OA components at the molecular level associated with BrC and BC particle light absorption and can serve as a basis for further studies on the effects of anthropogenic OA on radiative forcing in the urban environment.
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| 7. |
- Cai, Jing, et al.
(författare)
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Influence of organic aerosol molecular composition on particle absorptive properties in autumn Beijing
- 2022
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Ingår i: Atmospheric Chemistry and Physics. - 1680-7316 .- 1680-7324. ; 22, s. 1251-1269
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Tidskriftsartikel (refereegranskat)abstract
- Organic aerosol (OA) is a major component of fine particulate matter (PM), affecting air quality, human health, and the climate. The absorptive and reflective behavior of OA components contributes to determining particle optical properties and thus their effects on the radiative budget of the troposphere. There is limited knowledge on the influence of the molecular composition of OA on particle optical properties in the polluted urban environment. In this study, we characterized the molecular composition of oxygenated OA collected on filter samples in the autumn of 2018 in Beijing, China, with a filter inlet for gases and aerosols coupled to a high-resolution time-of-flight chemical ionization mass spectrometer (FIGAERO-CIMS). Three haze episodes occurred during our sampling period with daily maximum concentrations of OA of 50, 30, and 55 μg m-3. We found that the signal intensities of dicarboxylic acids and sulfur-containing compounds increased during the two more intense haze episodes, while the relative contributions of wood-burning markers and other aromatic compounds were enhanced during the cleaner periods. We further assessed the optical properties of oxygenated OA components by combining detailed chemical composition measurements with collocated particle light absorption measurements. We show that light absorption enhancement (Eabs) of black carbon (BC) was mostly related to more oxygenated OA (e.g., dicarboxylic acids), likely formed in aqueous-phase reactions during the intense haze periods with higher relative humidity, and speculate that they might contribute to lensing effects. Aromatics and nitro-aromatics (e.g., nitrocatechol and its derivatives) were mostly related to a high light absorption coefficient (babs) consistent with light-absorbing (brown) carbon (BrC). Our results provide information on oxygenated OA components at the molecular level associated with BrC and BC particle light absorption and can serve as a basis for further studies on the effects of anthropogenic OA on radiative forcing in the urban environment. Copyright:
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| 8. |
- Cai, Jing, et al.
(författare)
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Size-segregated particle number and mass concentrations from different emission sources in urban Beijing
- 2020
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Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 20:21, s. 12721-12740
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Tidskriftsartikel (refereegranskat)abstract
- Although secondary particulate matter is reported to be the main contributor of PM2.5 during haze in Chinese megacities, primary particle emissions also affect particle concentrations. In order to improve estimates of the contribution of primary sources to the particle number and mass concentrations, we performed source apportionment analyses using both chemical fingerprints and particle size distributions measured at the same site in urban Beijing from April to July 2018. Both methods resolved factors related to primary emissions, including vehicular emissions and cooking emissions, which together make up 76% and 24% of total particle number and organic aerosol (OA) mass, respectively. Similar source types, including particles related to vehicular emissions (1.6 +/- 1.1 mu gm(-3); 2.4 +/- 1.8 x 10(3) cm(-3) and 5.5 +/- 2.8 x 10(3) cm(-3) for two traffic-related components), cooking emissions (2.6 +/- 1.9 mu gm(-3) and 5.5 +/- 3.3 x 10(3) cm(-3)) and secondary aerosols (51 +/- 41 mu gm(-3) and 4.2 +/- 3.0 x 10(3) cm(-3)), were resolved by both methods. Converted mass concentrations from particle size distributions components were comparable with those from chemical fingerprints. Size distribution source apportionment separated vehicular emissions into a component with a mode diameter of 20 nm (traffic-ultrafine) and a component with a mode diameter of 100 nm (traffic-fine). Consistent with similar day- and nighttime diesel vehicle PM2.5 emissions estimated for the Beijing area, traffic-fine particles, hydrocarbon-like OA (HOA, traffic-related factor resulting from source apportionment using chemical fingerprints) and black carbon (BC) showed similar diurnal patterns, with higher concentrations during the night and morning than during the afternoon when the boundary layer is higher. Traffic-ultrafine particles showed the highest concentrations during the rush-hour period, suggesting a prominent role of local gasoline vehicle emissions. In the absence of new particle formation, our re-sults show that vehicular-related emissions (14% and 30% for ultrafine and fine particles, respectively) and cooking-activity-related emissions (32 %) dominate the particle number concentration, while secondary particulate matter (over 80 %) governs PM2.5 mass during the non-heating season in Beijing.
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| 9. |
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| 10. |
- Chen, Dongfeng, et al.
(författare)
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Glioma Cell Proliferation Controlled by ERK Activity-Dependent Surface Expression of PDGFRA.
- 2014
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Increased PDGFRA signaling is an essential pathogenic factor in many subtypes of gliomas. In this context the cell surface expression of PDGFRA is an important determinant of ligand sensing in the glioma microenvironment. However, the regulation of spatial distribution of PDGFRA in glioma cells remains poorly characterized. Here, we report that cell surface PDGFRA expression in gliomas is negatively regulated by an ERK-dependent mechanism, resulting in reduced proliferation of glioma cells. Glioma tumor tissues and their corresponding cell lines were isolated from 14 patients and analyzed by single-cell imaging and flow cytometry. In both cell lines and their corresponding tumor samples, glioma cell proliferation correlated with the extent of surface expression of PDGFRA. High levels of surface PDGFRA also correlated to high tubulin expression in glioma tumor tissue in vivo. In glioma cell lines, surface PDGFRA declined following treatment with inhibitors of tubulin, actin and dynamin. Screening of a panel of small molecule compounds identified the MEK inhibitor U0126 as a potent inhibitor of surface PDGFRA expression. Importantly, U0126 inhibited surface expression in a reversible, dose- and time-dependent manner, without affecting general PDGFRA expression. Treatment with U0126 resulted in reduced co-localization between PDGFRA and intracellular trafficking molecules e.g. clathrin, RAB11 and early endosomal antigen-1, in parallel with enhanced co-localization between PDGFRA and the Golgi cisternae maker, Giantin, suggesting a deviation of PDGFRA from the endosomal trafficking and recycling compartment, to the Golgi network. Furthermore, U0126 treatment in glioma cells induced an initial inhibition of ERK1/2 phosphorylation, followed by up-regulated ERK1/2 phosphorylation concomitant with diminished surface expression of PDGFRA. Finally, down-regulation of surface PDGFRA expression by U0126 is concordant with reduced glioma cell proliferation. These findings suggest that manipulation of spatial expression of PDGFRA can potentially be used to combat gliomas.
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