Unveiling the Molecular Characteristics, Origins, and Formation Mechanism of Reduced Nitrogen Organic Compounds in the Urban Atmosphere of Shanghai Using a Versatile Aerosol Concentration Enrichment System.

Reduced nitrogen-containing organic compounds (NOCs) in aerosols play a crucial role in altering their light-absorption properties, thereby impacting regional haze and climate. Due to the low concentration levels of individual NOCs in the air, the utilization of accurate detection and quantification technologies becomes essential. For the first time, this study investigated the diurnal variation, chemical characteristics, and potential formation pathways of NOCs in urban ambient aerosols in Shanghai using a versatile aerosol concentration enrichment system (VACES) coupled with HPLC-Q-TOF-MS. The results showed that NOCs accounted over 60% of identified components of urban organic aerosols, with O/N < 3 compounds being the major contributors (>70%). The predominance of the positive ionization mode suggested the prevalence of reduced NOCs. Higher relative intensities and number fractions of NOCs were observed during nighttime, while CHO compounds showed an opposite trend. Notably, a positive correlation between the intensity of NOCs and ammonium during the nighttime was observed, suggesting that the reaction of ammonium to form imines may be a potential pathway for the formation of reduced NOCs during the nighttime. Seven prevalent types of reduced NOCs in autumn and winter were identified and characterized by an enrichment of CH2 long-chain homologues. These NOCs included alkyl, cyclic, and aromatic amides in CHON compounds, as well as heterocyclic or cyclic amines and aniline homologue series in CHN compounds, which were associated with anthropogenic activities and may be capable of forming light-absorbing chromophores or posing harm to human health. The findings highlight the significant contributions of both primary emissions and ammonium chemistry, particularly amination processes, to the pollution of reduced NOCs in Shanghai's atmosphere.

Alkaloid diversity expansion of a talent fungus Penicillium raistrichii through OSMAC-based cultivation.

Introduction: Alkaloidal natural products are attractive for their broad spectrum of pharmaceutical bioactivities. In the present work, the highly productive saline soil derived fungus, Penicillium raistrichii, was subjected to the strategy of OSMAC (one strain many compounds) with changes of cultivation status. Then, the work-flow led to the expansion of the alkaloid chemical diversity and subsequently induced the accumulation of four undescribed alkaloids, named raistrimides A-D (1-4), including three ß-carbolines (1-3), one 2-quinolinone (4), and one new natural product, 2-quinolinone (5), along with five known alkaloid chemicals (6-10). Methods: A set of NMR techniques including 1H, 13C, HSQC and HMBC, along with other spectroscopic data of UV-Vis, IR and HRESIMS, were introduced to assign the plain structures of compounds 1-10. The absolute configuration of 1-3 were elucidated by means of X-ray crystallography or spectroscopic analyses on optical rotation values and experimental electronic circular dichroism (ECD) data. In addition, it was the first report on the confirmation of structures of 6, 7 and 9 by X-ray crystallography data. The micro-broth dilution method was applied to evaluate antimicrobial effect of all compounds towards Staphylococcus aureus, Escherichia coli, and Candida albicans. Results and discussion: The results indicated compounds 1, 3 and 4 to be bioactive, which may be potential for further development of anti-antimicrobial agents. The finding in this work implied that OSMAC strategy was a powerful and effective tool for promotion of new chemical entities from P. raistrichii.

Accurate observation of black and brown carbon in atmospheric fine particles via a versatile aerosol concentration enrichment system (VACES).

Carbonaceous aerosols (CAs) are major components of fine particulate matter (PM2.5) that dramatically influence the energy budget of Earth. However, accurate assessment of the climatic impacts of CAs is still challenging due to the large uncertainties remaining in the measurement of their optical properties. In this respect, a modified versatile aerosol concentration enrichment system integrated into optical instruments (VACES-OPTS) was set up to increase particle concentration and amplify signal-noise ratio during optical measurement. Based on the novel technique, this study was able to lower the detection limit of CAs by an order of magnitude under high temporal resolution (2 h) and small sampling flow (6 L min-1). Besides, stable and reliable optical data were obtained for absorption apportionment and source identification of black carbon (BC) and brown carbon (BrC). In the field application of the new system, high absorption coefficient of CAs in Shanghai, China was witnessed. Further analysis of the contribution of black carbon BC and BrC to light absorption revealed that BrC could account for over 15% of the total absorption at 370 nm. According to the potential source contribution function model (PSCF) classification, CAs with strong light absorption in urban Shanghai originated not only from highly polluted inland China but also from active marine ship emissions.

PM1.0-Nitrite Heterogeneous Formation Demonstrated via a Modified Versatile Aerosol Concentration Enrichment System Coupled with Ion Chromatography.

Particulate nitrite is a critical source of hydroxyl radicals; however, it lacks high-resolution methods due to its low abundance and stability to explore its formation mechanism. In this study, a modified versatile aerosol concentration enrichment system (VACES) coupled with ion chromatography (IC) was used to measure particulate NO2- hourly online and achieve a lowered detection limit of 10-3 µg m-3. VACES-IC was used to observe a high- and low-concentration events of PM1.0-NO2- in Shanghai, corresponding to the ambient-level concentrations of 0.34 and 0.05 µg m-3, respectively. The morning peak concentrations of NO2- even exceeded 3σ (standard deviation) in the high-concentration event due to the reduction of NO2 by aerosol SO32- based on kinetics and regression analysis. This implies that controlling SO2 emissions would be an effective strategy to decrease morning NO2- concentrations, correspondingly reducing the kinetic formation of SO42- by 20.8-34.8%. However, after sunrise, NO2- formation was primarily attributed to NO2 hydrolysis at pH 4.97-6.14. In the low-concentration event, NO2 hydrolysis also accounted for an overwhelming proportion (∼90%) of NO2- formation. This work estimates the contribution of different paths to particulate NO2- formation based on newly established high-resolution measurements.

Iizukines C-E from a saline soil fungus Aspergillus iizukae.

Three new alkaloids, iizukines C-E (1-3), including two aspochalasins (1 and 2), and one brasiliamide derivative (3), along with two known aspochalasins, rosellichalasin (4) and cytochalasin Z17 (5), were isolated from the culture of Aspergillus iizukae. Compound 1 was the first aspochalasin uniquely featuring a 1,2,4-triazole functionality, and 3 showed a pair of NMR signals in CDCl3 with a ratio of about 2:1 due to the existence of conformational isomers. Their structures were determined by extensive spectroscopic analyses and single-crystal X-ray diffractions. In particular, the 1,2,4-triazole moiety in 1 was assigned on the basis of extremely valuable 1H-15N HMBC spectrum. Compound 1 exhibited cytotoxic effect towards HL-60 and A549 cell lines with IC50 values of 3.8 and 7.2 µM, respectively.

New Butenolides and Cyclopentenones from Saline Soil-Derived Fungus Aspergillus Sclerotiorum.

Three new γ-hydroxyl butenolides (1-3), a pair of new enantiomeric spiro-butenolides (4a and 4b), a pair of enantiomeric cyclopentenones (5a new and 5b new natural), and six known compounds (6-11), were isolated from Aspergillus sclerotiorum. Their structures were established by spectroscopic data and electronic circular dichroism (ECD) spectra. Two pairs of enantiomers [(+)/(-)-6c and (+)/(-)-6d] obtained from the reaction of 6 with acetyl chloride (AcCl) confirmed that 6 was a mixture of two pairs of enantiomers. In addition, the X-ray data confirmed that 7 was also a racemate. The new metabolites (1-5) were evaluated for their inhibitory activity against cancer and non-cancer cell lines. As a result, compound 1 exhibited moderate cytotoxicity to HL60 and A549 with IC50 values of 6.5 and 8.9 µM, respectively, and weak potency to HL-7702 with IC50 values of 17.6 µM. Furthermore, compounds 1-9 were screened for their antimicrobial activity using the micro-broth dilution method. MIC values of 200 µg/mL were obtained for compounds 2 and 3 towards Staphylococcus aureus and Escherichia coli, while compound 8 exhibited a MIC of 50 µ/mL towards Candida albicans.

Improving photoelectrochemical response of ZnO nanowire arrays by coating with p-type ZnO-resembling metal-organic framework.

Coupling semiconducting metal-organic frameworks (MOFs) with metal oxide (MO) semiconductor nanowires is an efficient solution to tune the photoelectric properties of both the parties. In this report, we demonstrate a facile surfactant-free growth strategy for modification of zinc oxide (ZnO) single-crystal nanowire arrays (NWAs) with the MOF zinc glycolate (noted as Zn-GA) that contains an embedded continuous 3D Zn-O network. Due to the structural resemblance of the Zn-O network between Zn-GA and ZnO, the prepared ZnO@Zn-GA nanowires present a tight contact at the core-shell interface in a partially epitaxial manner, and the loading amount of Zn-GA can be well controlled in the synthetic process. The inherent p-type Zn-GA in combination with the widely available n-type ZnO assures the construction of tandem n-p heterojunctions at the core-shell interface, which is confirmed by Mott-Schottky analysis. By implementation of the ZnO@Zn-GA NWAs as photoanodes for photoelectrochemical oxidation of water and oxalic acid, improved photocurrent responses are obtained relative to the primary ZnO NWAs. The most significant photoresponse is observed in the ZnO nanowires shelled by a compact Zn-GA particulate thin film with the largest junction region. These results are elucidated by the enhanced spatial separation efficiency of photogenerated charge carriers, which is favored by the built-in electric field at the interface of the n-p heterojunctions.

Potential Antiviral Xanthones from a Coastal Saline Soil Fungus Aspergillus iizukae.

Five new (1⁻5) and two known xanthones (6 and 7), one of the latter (6) obtained for the first time as a natural product, together with three known anthraquinones, questin, penipurdin A, and questinol, were isolated from the coastal saline soil-derived Aspergillus iizukae by application of an OSMAC (one strain many compounds) approach. Their structures were determined by interpretation of nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectroscopy (HRESIMS) data, as well as comparison of these data with those of related known compounds. Antiviral activity of xanthones 1-7 was evaluated through the cytopathic effect (CPE) inhibition assay, and compound 2 exhibited distinctly strong activity towards influenza virus (H1N1), herpes simplex virus types 1 (HSV-1) and 2 (HSV-2) with IC50 values of 44.6, 21.4, and 76.7 µM, respectively, which indicated that it was worth to further investigate it as a potential lead compound. The preliminary structure-activity relationship of the xanthones is discussed.

Raistrickiones A-E from a Highly Productive Strain of Penicillium raistrickii Generated through Thermo Change.

Three new diastereomers of polyketides (PKs), raistrickiones A−C (1⁻3), together with two new analogues, raistrickiones D and E (4 and 5), were isolated from a highly productive strain of Penicillium raistrickii, which was subjected to an experimental thermo-change strategy to tap its potential of producing new secondary metabolites. Metabolites 1 and 2 existed in a diastereomeric mixture in the crystal packing according to the X-ray data, and were laboriously separated by semi-preparative HPLC on a chiral column. The structures of 1⁻5 were determined on the basis of the detailed analyses of the spectroscopic data (UV, IR, HRESIMS, 1D, and 2D NMR), single-crystal X-ray diffractions, and comparison of the experimental and calculated electronic circular dichroism spectra. Compounds 1⁻5 represented the first case of 3,5-dihydroxy-4-methylbenzoyl derivatives of natural products. Compounds 1⁻5 exhibited moderate radical scavenging activities against 1,1-diphenyl-2-picrylhydrazyl radical 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl (DPPH).

Pyran Rings Containing Polyketides from Penicillium raistrickii.

Five new pyran rings containing polyketides, penicipyrans A-E (1-5), together with the known pestapyrone A (6), were isolated from the saline soil-derived Penicillium raistrickii. Their structures were determined by interpretation of NMR and HRESIMS data. The absolute configurations of compounds 4 and 5 were established by the modified Mosher's method and single-crystal X-ray diffraction analysis, respectively. These compounds possessed high structural diversity including two α-pyrones (1, 2), three isocoumarins (3, 4, 6), and one dihydropyran derivative (5). Among them, Compound 5 exhibited cytotoxicity against HL-60 and K562 cell lines with IC50 values of 4.4 and 8.5 µM, respectively.

The Clinical Implications of Transforming Growth Factor Beta in Pathological Grade and Prognosis of Glioma Patients: A Meta-Analysis.

The transforming growth factor beta (TGF-ß) pathway plays a key role in oncogenesis of advanced cancers. However, the effects of TGF-ß pathway on gliomas are still controversial. So, it is essential to conduct a meta-analysis to determine their correlations. Eligible studies were included, and then odds ratios (ORs), standard mean differences (SMDs), and hazard ratios (HRs) with 95 % confidence intervals (95% CIs) were estimated. Funnel plots were available for evaluation of publication bias. In this meta-analysis, all 14 eligible studies involving 875 patients were included and conducted in China. Six studies with dichotomous data revealed altered TGF-ß expression in glioma tissues was closely associated with high WHO grade (III + IV) (OR 4.39, 95% CI 2.90-6.63; p = 0.000), meanwhile, seven studies with continuous data also demonstrated TGF-ß expression intensity extremely related to high grade (SMD -2.44, 95% CI -2.71, -2.16; p = 0.000). To our interest, TGF-ß expression was associated with old age (OR 0.59, 95% CI 0.36-0.93; p = 0.025) rather than gender (OR 1.04, 95% CI 0.64-1.67; p = 0.884). Besides, TGF-ß expression significantly correlated to 3-year-OS (n = 2; HR 2.53, 95% CI 1.18-5.41; p = 0.017) rather than 5-year-OS (n = 1; HR 1.04, 95% CI 0.66-1.64; p = 0.872) in glioma patients. No heterogeneity and publication bias were observed across all studies. Taken together, the present meta-analysis testifies TGF-ß is potently associated with high grade and poor 3 years prognosis, and TGF-ß test combined with survivin [1 Mol Neurobiol] and MMP9 [2 Mol Neurobiol] in glioma tissues should be clinically recommended as criteria of glioma grade in department of pathology.

The association of CXCR4 expression with prognosis and clinicopathological indicators in colorectal carcinoma patients: a meta-analysis.

AIMS: The clinical relevance of expression of chemokine receptor 4 (CXCR4) in colorectal carcinoma (CRC) remains controversial; our aim was to identify the precise relationship of CXCR4 to prognosis and clinicopathological features. METHODS AND RESULTS: A meta-analysis was performed. Original data included the hazard ratios (HRs) of recurrence-free survival (RFS), overall survival (OS) and odds ratio (OR) in CRC patients. We pooled HR/OR with 95% confidence intervals (CIs) to estimate the hazard. A total of 20 published studies (including 2253 patients) were eligible. RFS and OS were related significantly to CXCR4 expression, with HRs 1.62 (95% CI 1.24-2.11; P < 0.0001) and 1.68 (95% CI 1.31-2.14; P < 0.0001), respectively. In addition, a significant association was revealed between positive CXCR4 expression and age (less than median age: OR 0.78, 95% CI 0.62-0.98; P = 0.03), stage (I and II: OR 0.46, 95% CI 0.32-0.66; P < 0.0001), grade (well/moderately differentiated: OR 0.74, 95% CI 0.56-0.98; P = 0.04), location (colon: OR: 0.73, 95% CI 0.57-0.95; P = 0.02), lymph node invasion (present: OR2.14, 95% CI 1.36-3.37; P = 0.001),and distant metastasis (present: OR 2.40; 95% CI 1.36-4.23; P = 0.003). Heterogeneity was observed among the included studies with regard to stage (I(2) = 58 %), lymph node invasiveness (I(2) = 74%) and distant metastasis (I(2) = 56%). No publication bias was observed. CONCLUSIONS: Chemokine receptor 4 expression indicates poorer prognosis in older patients and advanced stage or poor differentiation in CRC, and also serves as an indicator of lymph node and distal organ metastasis. Surprisingly, high CXCR4 expression may indicate that the location of the tumour is the rectum. Thus, CXCR4 could help to predict outcome and guide clinical therapy.

Prognostic and clinicopathological significance of survivin expression in bladder cancer patients: a meta-analysis.

Survivin has been widely reported to play a role in diagnosis and prognosis of bladder cancer patients. However, published data on this subject are heterogeneous. Here, we conducted a meta-analysis to obtain a complete evaluation of the association between survivin and recurrence-free survival (RFS), disease-specific survival (DSS), overall survival (OS), and odds ratio (OR) in bladder cancer patients. Published studies on this subject were selected for further assessment by online articles in PubMed, MEDLINE, EMBASE, and OVID databases. Pooled hazard ratios (HR) with 95 % confidence interval (95 % CI) were estimated. Funnel plots were used to evaluate the publication bias. As well, heterogeneity and sensitivity were analyzed. In this meta-analysis, we included 13 studies with the total number of 1,963 patients. Positive survivin expression in bladder cancer was associated with a poor RFS (HR, 1.831; 95 % CI, 1.344-2.49), DSS (HR, 1.721; 95 % CI, 1.477-2.004), or OS (HR, 1.753; 95 % CI, 1.092-2.816) in patients. In addition, a significant association between expression of survivin and age (OR, 0.641; 95 % CI, 0.416-0.987) as well as stage (OR, 0.37; 95 % CI, 0.190-0.750) was revealed. Heterogeneity was observed among the included studies with RFS (x (2) =29.58, p = 0.009, I (2) = 52.7 %), OS (x (2) = 15.67, p = 0.008, I (2) = 68.1 %), and stage (x (2) = 11.97, p = 0.035, I (2) = 58.2 %). There was no publication bias according to Begg's and Egger's tests except for studies with gender. Furthermore, sensitivity analysis obtained the source of heterogeneity and confirmed opposite results of some studies. This study suggests that expression of survivin indicates poor prognosis in older patients and muscle invasive or advanced stage in bladder cancer. Survivin expression could be used in identifying a subgroup of patients with potential to benefit from a targeted therapy against survivin.

CrkL efficiently mediates cell proliferation, migration, and invasion induced by TGF-ß pathway in glioblastoma.

Crk-like (CrkL) is an adapter protein that has crucial roles in cell proliferation, adhesion, and migration. However, the expression pattern and potential mechanism of CrkL protein in glioblastoma multiforme (GBM) have not been fully elucidated. To determine roles of CrkL in cell signaling, proliferation, and migration, small interfering RNAs and plasmids transfection were used to suppress or overexpress CrkL in U87 and U251; soft-agar assay and wound-healing assay were used to observe cell invasiveness, migration, and proliferation. Erk1/2, Smad2, and matrix metalloproteinase 9 (MMP9) were also analyzed by western blot. CrkL was expressed in U87 and U251 cell lines and can be activated by transforming growth factor-beta 1 (TGF-ß1) in vitro; CrkL knockdown significantly suppressed the expression of phosph-ERK1/2 and MMP9 but enhanced phosph-Smad2 expression compared with control (p <0.001). Overexpression of CrkL against control upregulated phosph-ERK1/2 and MMP9 and, at the same time, downregulated phosph-Smad2 (p <0.01). On the other hand, CrkL knockdown could significantly affect U87 and U251 invasiveness (p <0.01) and wound closure (p <0.01) using soft-agar assay and wound-healing assay. These studies suggest that CrkL efficiently mediates cell proliferation, migration, and invasion induced by TGF-ß pathway in glioblastoma. Furthermore, CrkL can be used as a potential and efficient therapeutic target of GBM and may also mediate other signaling pathway.