Potential Effects of Traditional Chinese Medicine on COVID-19 and Cardiac Injury: Mechanisms and Clinical Evidence.

Coronavirus disease 2019 is a "Public Health Emergency of International Concern" from 30 January 2020 to 5 May 2023. While battling Coronavirus disease 2019, the Chinese government has actively promoted the collaborative treatment model of Western medicine and traditional Chinese medicine, and clinical and scientific research has applied appropriate and rigorous methodology. Severe acute respiratory syndrome coronavirus 2 infection may damage the cardiovascular system via an unclarified pathogenic mechanism. The National Health Commission of China recommends 'three formulas and three medicines' for the treatment of coronavirus disease 2019, which have been shown to be most effective in the treatments. Data from randomized controlled trials of 'three formulas and three medicines' suggested that the traditional Chinese medicine is safe and can alleviate the symptoms of cardiac injury. Therefore, we further evaluate the benefits and safety of traditional Chinese medicine treatment for Coronavirus disease 2019 patients with cardiac injury across the care continuum.

Circ_0000395 Promoted CRC Progression via Elevating MYH9 Expression by Sequestering miR-432-5p.

Colorectal cancer (CRC) has been listed as the fourth deadly cancer. Circular RNA hsa_circRNA_001046, also termed as hsa_circ_0000395 (circ_0000395), has been shown to be upregulated in CRC. Nevertheless, the function of circ_0000395 in CRC progression is unclear. 42 CRC patients were enrolled in the study. Detection of circ_0000395 expression in tissues and cells was executed using real-time quantitative polymerase chain reaction (RT-qPCR). Evaluation of circ_0000395 function was performed using loss-of-function experiments in vitro and in vivo. The regulatory mechanism of circ_0000395 was predicted by bioinformatics analysis and validated by dual-luciferase reporter and RIP assays. Exosomes were isolated by ultracentrifugation and validated by western blotting, TEM, and NTA. Circ_0000395 was strongly expressed in CRC samples and cell lines. Also, circ_0000395 repressed CRC growth in mouse models in vivo and induced CRC cell apoptosis, restrained CRC cell proliferation, migration, invasion, and EMT in vitro. Mechanistically, circ_0000395 sequestered miR-432-5p to regulate MYH9 expression. Furthermore, miR-432-5p knockdown reversed circ_0000395 silencing-mediated effects on CRC cell malignant phenotypes. MYH9 overexpression counteracted the inhibiting effects of miR-432-5p upregulation on CRC cell malignant phenotypes. Additionally, CRC cells derived from exosomal circ_0000395 promoted cancer cell malignant phenotypes. Our findings demonstrated that circ_0000395 sequestered miR-432-5p to elevate MYH9 expression, resulting in facilitating CRC progression, manifesting a potential therapeutic target for CRC.

Cardioprotective Role of Swertiamarin, a Plant Glycoside Against Experimentally Induced Myocardial Infarction via Antioxidant and Anti-inflammatory Functions.

The study examined the protective effects of swertiamarin on rats with experimentally induced myocardial infarction. Three to six week-old male albino Wistar rats were used in this study and experimental myocardial infarction (MI) was induced using isoproterenol. Our results showed that swertiamarin restored the alteration in heart weight, body weight, and heart weight/tibia length ratio of MI-induced rats to basal levels significantly (p < 0.05). Swertiamarin significantly (p < 0.05) restored the levels of cardiac pathophysiological marker creatine kinase (CKMB), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), alanine transaminase (ALT), and cardiac troponin I (cTn-1) to near normalcy in MI-induced rats. Levels of oxidative stress markers malondialdehyde (MDA), protein carbonyls (PC), and levels of Vitamin C and Vitamin E were significantly (p < 0.05) reverted to near basal levels in MI-induced rats by swertiamarin. Levels of the antioxidant glutathione (GSH) and antioxidant enzymes which include superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-s-transferase (GST), glutathione reductase (GR), and plasma total antioxidant capacity (TAC) were (p < 0.05) brought to near normalcy in MI-induced rats by swertiamarin. Levels of sodium (Na), potassium (k), and calcium (Ca) ATPases were significantly (p < 0.05) restored to near normalcy in MI-induced rats by swertiamarin. Status of pro-inflammatory cytokines including tumor necrosis factor (TNF-α), interleukin-6 (IL-6), and histological aberrations were also significantly (p < 0.05) restored to near normalcy in MI-induced rats by swertiamarin. Together, our results concluded that swertiamarin exerts significant cardioprotective functions in experimental MI in rats.

Clinical value of conventional magnetic resonance imaging combined with diffusion-weighted imaging in predicting pelvic lymph node metastasis of cervical cancer.

Background: In cervical cancer (CC), the involvement of pelvis lymph nodes is a crucial factor for patients' outcome. We aimed to investigate the value of conventional magnetic resonance imaging (MRI) combined with diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC) in predicting CC pelvic lymph node metastasis (PLNM). Methods: This retrospective study included CC patients who received surgical treatments. Surgical pathology results served as the gold standard for investigating the diagnostic performance of conventional MRI combined with DWI. We analyzed the association between tumor ADC and PLNM, as well as other pathological factors. The areas under the receiver operating characteristic curves (AUCs) for ADC in assessing PLNM and pathological factors were evaluated, and optimal cut-off points were obtained. Results: A total of 261 CC patients were analyzed. PLNM patients had significantly lower tumor ADC (0.829 ± 0.144×10-3mm2/s vs. 1.064 ± 0.345×10-3mm2/s, p<0.0001), than non-PLNM CC. The agreement between conventional MRI combined with DWI and pathological results on PLNM diagnosis was substantial (Kappa=0.7031, p<0.0001), with 76% sensitivity, 94.31% specificity, and 90.8% accuracy. The AUC of tumor ADC was 0.703, and the optimal cut-off was 0.95×10-3 mm2/s. In multivariate analysis model 1, tumor ADC<0.95×10-3mm2/s was significantly associated with PLNM (OR, 2.83; 95%CI, 1.08-7.43; p= 0.0346) after adjusting for age and pathological risk factors. In multivariate analysis model 2, tumor ADC<0.95×10-3mm2/s (OR, 4.00; 95%CI, 1.61-9.89; p=0.0027), age<35 years old (OR, 2.93; 95%CI, 1.04-8.30; p=0.0428), increased tumor diameter on MRI (OR, 2.17; 95%CI, 1.18-3.99; p=0.0128), vaginal vault involvement on MRI (OR, 2; 95%CI, 1.002-3.99; p=0.0494) were independent predictors for PLNM. Tumor ADC<0.95×10-3mm2/s was significantly associated with higher risk of tumor diameter ≥4cm (OR, 2.60; 95%CI, 1.43-4.73; p=0.0017), muscular layer infiltration >1/2 (OR, 5.46; 95%CI, 3.19-9.34; p<0.0001), vaginal vault involvement (OR, 2.25; 95%CI, 1.28-3.96; p=0.0051), and lymphovascular space involvement (OR, 3.81; 95%CI, 2.19-6.63; p<0.0001). Conclusion: Conventional MRI combined with DWI had a good diagnostic performance in detecting PLNM. The tumor ADC value in PLNM patients was significantly lower than that in non-PLNM patients. Tumor ADC <0.95×10-3mm2/s, age <35 years old, increased tumor diameter on MRI, vaginal vault involvement on MRI were independent predictors for PLNM.

Traditional Chinese Medicine in Treatment of COVID-19 and Viral Disease: Efficacies and Clinical Evidence.

Coronavirus disease 2019 (COVID-19) remains an uncontained, worldwide pandemic. While battling the disease in China, the Chinese government has actively promoted the use of traditional Chinese medicine, and many studies have been conducted to determine the efficacy of traditional Chinese medicine for treating COVID-19. The present review discusses the effectiveness and safety of traditional Chinese medicine in curing COVID-19 and provides clinical evidence from all confirmed cases in China. Applications of traditional Chinese medicine and specific recipes for treating other viral infections, such as those caused by severe acute respiratory syndrome coronavirus and influenza A viruses (including H1N1), are also discussed. Studies have reported that traditional Chinese medicine treatment plays a significant role in improving clinical symptoms. Therefore, further investigation may be of high translational value in revealing novel targeted therapies for COVID-19.

The Preparation of N-Doped Titanium Dioxide Films and Their Degradation of Organic Pollutants.

N-doped TiO2 films supported by glass slides showed superior photocatalytic efficiency compared with naked TiO2 powder due to them being easier to separate and especially being responsive to visible light. The films in this study were prepared via the sol-gel method using TBOT hydrolyzed in an ethanol solution and the nitrogen was provided by cabamide. The N-doped TiO2 coatings were prepared via a dip-coating method on glass substrates (30 × 30 × 2 mm) and then annealed in air at 490 °C for 3 h. The samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-vis. The doping rate of N ranged from 0.1 to 0.9 (molar ratio), which caused redshifts to a longer wavelength as seen in the UV-vis analysis. The photocatalytic activity was investigated in terms of the degradation of phenol under both UV light and visible light over 4 h. Under UV light, the degradation rate of phenol ranged from 86% to 94% for all the samples because of the sufficient photon energy from the UV light. Meanwhile, under visible light, a peak appeared at the N-doping rate of 0.5, which had a degrading efficiency that reached 79.2%, and the lowest degradation rate was 32.9%. The SEM, XRD and UV-vis experimental results were consistent with each other.

Dihydromyricetin ameliorates osteogenic differentiation of human aortic valve interstitial cells by targeting c-KIT/interleukin-6 signaling pathway.

Aims: Calcific aortic valve disease (CAVD) is a chronic cardiovascular disease with high morbidity that lacks effective pharmacotherapeutics. As a natural flavonoid extracted from Ampelopsis grossedentata, dihydromyricetin (DHM) has been shown to be effective in protecting against atherosclerosis; yet, the therapeutic role of DHM in CAVD remains poorly understood. Herein, we aimed to clarify the therapeutic implications of DHM in CAVD and the underlying molecular mechanisms in human valvular interstitial cells (hVICs). Methods and Results: The protein levels of two known osteogenesis-specific genes (alkaline phosphatase, ALP; runt-related transcription factor 2, Runx2) and calcified nodule formation in hVICs were detected by Western blot and Alizarin Red staining, respectively. The results showed that DHM markedly ameliorated osteogenic induction medium (OM)-induced osteogenic differentiation of hVICs, as evidenced by downregulation of ALP and Runx2 expression and decreased calcium deposition. The SwissTargetPrediction database was used to identify the potential AVC-associated direct protein target of DHM. Protein-protein interaction (PPI) analysis revealed that c-KIT, a tyrosine-protein kinase, can act as a credible protein target of DHM, as evidenced by molecular docking. Mechanistically, DHM-mediated inhibition of c-KIT phosphorylation drove interleukin-6 (IL-6) downregulation in CAVD, thereby ameliorating OM-induced osteogenic differentiation of hVICs and aortic valve calcification progression. Conclusion: DHM ameliorates osteogenic differentiation of hVICs by blocking the phosphorylation of c-KIT, thus reducing IL-6 expression in CAVD. DHM could be a viable therapeutic supplement to impede CAVD.

The KMT1A/TIMP3/PI3K/AKT circuit regulates tumor growth in cervical cancer.

The epigenetic mechanism of tissue inhibitor of metalloproteinase 3 (TIMP3), a well-known tumor suppressor, in cervical cancer (CC) is still unclear. Integrated GEO database, protein interaction network, and a pan-cancer analysis revealed a KMT1A/TIMP3 axis in CC. KMT1A was highly expressed, and TIMP3 was poorly expressed in CC tissues and cells. KMT1A inhibited the activity of TIMP3. Silencing of KMT1A hampered the proliferation, migration, invasion, tumorigenesis and metastases of CC cells in vivo, and increased the apoptosis of cells. TIMP3 downregulation promoted the malignant phenotype and in vivo tumorigenesis and metastasis of CC cells. KMT1A downregulation impaired PI3K/AKT pathway in cells, while TIMP3 silencing promoted PI3K/AKT pathway activity. We propose a novel perspective that KMT1A involves in the growth and metastases via the TIMP3/PI3K/AKT axis in CC. In summary, our study identified a vital role played by KMT1A in the development of CC and the epigenetic mechanism, indicating that targeting KMT1A-related pathways could be conducive to the therapies for CC.

G protein-coupled receptor MAS1 induces an inhibitory effect on myocardial infarction-induced myocardial injury.

Myocardial infarction (MI) is the most prevalent disease with high mortality, leading to devastating heart injury. Here, we aimed to explore the effect of MAS1 on the MI-induced myocardial injury. Significantly, we identified that the expression of MAS1 was decreased in the MI rat model and hypoxia and reoxygenation (H/R)-treated H9C2 cells. Hematoxylin & Eosin (H&E) staining revealed that the overexpression of MAS1 notably attenuated MI-related myocardium injury in the MI rat model. Echocardiography analysis revealed that MI inhibited left ventricular ejection fraction (LVEF) and left ventricular fraction shortening (LVFS), whereas the MAS1 overexpression could increase LVEF and LVFS in the MI rats. Meanwhile, the expression of collagen I, collagen III, α-SMA, ANP, and BNP was decreased by MAS1 overexpression in the MI rats. MAS1 attenuated cardiomyocyte apoptosis in vivo and in vitro. Mechanically, the overexpression of MAS1 decreased the expression of PTEN and enhanced the phosphorylation of PI3K and AKT in vivo and in vitro. The overexpression of PTEN and the PI3k inhibitor LY294002 could reverse the MAS1-mediated MI injury. Thus, we conclude that MAS1 inhibits MI-induced myocardial injury by modulating PTEN/PI3K/AKT signaling. Our finding provides new insight into the mechanism by which MAS1 attenuates MI-related cardiac dysfunction.

A rare case report: vaginal paraganglioma.

Vaginal paraganglioma (VP), usually solitary and primary, is a rare adrenal type paraganglioma derived from the anterior neural crest, and can be classified as a functional or non-functional tumor. Only 10 cases of VP have been reported since 1955. Herein, we report an unusual case of a 39-year-old female VP patient with symptoms of hypercatecholaminism and a family history of hypertension. After preoperative control of blood pressure with an alpha-receptor blocker, laparoscopic surgery was performed. The blood pressure fluctuated after touching the tumor intraoperatively, and the tumor was successfully and completely removed under anesthesia by surgery. Postoperative pathology confirmed the diagnosis. The clinical characteristics, auxiliary examination, morphological and pathological immunohistochemical characteristics, and perioperative treatment of VP are analyzed, and the literature of the previous 10 cases is reviewed, so as to help further understand VP and provide clinical guidance.

Response of heavy metal and antibiotic resistance genes and related microorganisms to different heavy metals in activated sludge.

With the recent growing interest of antibiotic resistance genes (ARGs) and their co-selection with heavy metal resistance genes (HMRGs), their relationship to heavy metals needs further analysis. This study examined the response of heavy metal resistant microorganisms (HMRMs) and antibiotic resistant microorganisms (ARMs) and their resistance genes (HMRGs and ARGs) to Cu and Cr stresses using metagenome. Results showed that Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Deltaproteobacteria, and Nitrospirae are the dominant HMRMs and ARMs, with majority of HMRMs taxa presenting changes similar to ARMs under heavy metal stresses. Types of HMRGs and ARGs changed (increased or decreased) under Cu and Cr stresses, and a significant relationship was noted between HMRGs and ARGs and their related microbe (p < 0.05). Network analysis revealed synergistic relationships between majority of HMRGs and ARGs; however, negative correlations were also noted between them. Co-occurrence of HMRGs and ARGs was mainly observed in chromosomes, and plasmids were found to provide limited opportunities for heavy metals to promote antibiotic resistance through co-selection. These findings imply that the response of HMRMs and ARMs is induced by heavy metals, and that the changes in these microbial communities are the main factor driving the diversity and abundance of HMRGs and ARGs.

Mercury accumulation in vegetable Houttuynia cordata Thunb. from two different geological areas in southwest China and implications for human consumption.

Houttuynia cordata Thunb. (HCT) is a common vegetable native to southwest China, and grown for consumption. The results suggested that THg contents in all parts and MeHg in underground parts of HCT in Hg mining areas were much higher than those in non-Hg mining areas. The highest THg and MeHg content of HCT were found in the roots, followed by the other tissues in the sequence: roots > leaves > rhizomes > aboveground stems (THg), and roots > rhizomes > aboveground stems > leaves (MeHg). The average THg bioaccumulation factor (BCF) of HCT root in the Hg mining area and in non-Hg mining areas could reach 1.02 ± 0.71 and 0.99 ± 0.71 respectively, indicating that HCT is a Hg accumulator. And the THg and MeHg contents in all tissues of HCT, including the leaves, were significantly correlated with THg and MeHg content in the soil. Additionally, preferred dietary habits of HCT consumption could directly affect the Hg exposure risk. Consuming the aboveground parts (CAP) of HCT potentially poses a high THg exposure risk and consuming the underground parts (CUP) may lead to a relatively high MeHg exposure risk. Only consuming the rhizomes (OCR) of the underground parts could significantly reduce the exposure risk of THg and to some extent of MeHg. In summary, HCT should not be cultivated near the Hg contaminated sites, such as Hg tailings, as it is associated with a greater risk of Hg exposure and high root Hg levels, and the roots should be removed before consumption to reduce the Hg risk.

Metagenomic analysis of the inhibitory effect of chromium on microbial communities and removal efficiency in A2O sludge.

This is the first study exploring the effects of persistent Cr(VI) treatment on microbial communities and function as well as the process efficiency of an A2O system. The inhibitory effect was clearly higher at a high Cr(VI) concentration than a low Cr(VI) concentration, and different Cr(VI) concentrations had distinct effects on the microbial communities as well as on the performance efficiency of the system. Functional annotation analysis indicated that Cr(VI) stress inhibited most of the metabolic pathway and functional genes of the microbial communities, especially those involved in the denitrification pathway. Network analysis was used to investigate the co-occurrence patterns between denitrification genes and microbial taxa; the results indicated that microorganisms with functional genes had high diversity and were adversely affected by Cr(VI) exposure. This study is the first to establish a relationship between Cr(VI) stress and microbial communities and function as well as to determine the underlying mechanisms and roles of Cr(VI) in A2O sludge.

The Shock Effect of Inorganic Suspended Solids in Surface Runoff on Wastewater Treatment Plant Performance.

Previous studies on the water quality of surface runoff often focused on the chemical oxygen demand (COD), nitrogen, phosphorus, and total suspended solid (TSS), but little is known in terms of the inorganic suspended solids (ISS). This research investigated the effects of ISS carried by surface runoff on the treatment efficiency of the pretreatment facilities and the ratio of mixed liquor volatile suspended solid to mixed liquor suspended solid (MLVSS/MLSS) of the activated sludge in a wastewater treatment plant (WWTP) with the anaerobic-anoxic-oxic (AAO) process in Chongqing city, China. The results showed that the surface runoff had a long-lasting impact on the grit removal capacity of the grit chamber, affecting the normal operation after the rainfall. In contrast, the primary sedimentation tank showed strong impact resistance with higher removal rates of COD, TSS, and ISS. Nonetheless, the primary settling tank aggravates the removal of organic carbon in sewage during rainfall, having a negative impact on subsequent biological treatment. The ISS in the surface runoff could increase the sludge concentration and decrease the MLVSS/MLSS ratio. After repeated surface runoff impact, the MLVSS/MLSS ratio in the activated sludge would drop below even 0.3, interrupting the normal operation of WWTP.

Ti3+ self-doped mesoporous black TiO2/graphene assemblies for unpredicted-high solar-driven photocatalytic hydrogen evolution.

Ti3+ self-doped mesoporous black TiO2/graphene assemblies are fabricated by a facile solvothermal method and surface hydrogenation. The structure, crystallinity, morphology, and chemical state of the as-prepared samples are characterized in detail by X-ray diffraction, Raman, X-ray photoelectron spectroscopy, transmission electron microscopy, N2 adsorption and UV-visible diffuse reflectance spectroscopy. The results show that the presence of Ti3+ can efficiently extend the photoresponse of anatase TiO2 to visible light region. The solar-driven photocatalytic hydrogen evolution shows that Ti3+ self-doped mesoporous black TiO2/graphene assemblies exhibit the highest photocatalytic activity (186µmolh-1 0.01g-1), exceeding to mesoporous TiO2/graphene assemblies and mesoporous black TiO2. It also exhibits superior photoelectrochemical properties compared with mesoporous TiO2/graphene assemblies. The unpredicted-high photocatalytic performance is attributed to the close contact between the unique two-dimensional graphene structures coupled with TiO2 mesoporous architectures resulting in outstanding charge separation efficient and the Ti3+ self-doping extending the utilization ratio of visible light.

Effects of C/N ratio on nitrous oxide production from nitrification in a laboratory-scale biological aerated filter reactor.

Emission of nitrous oxide (N2O) during biological wastewater treatment is of growing concern. This paper reports findings of the effects of carbon/nitrogen (C/N) ratio on N2O production rates in a laboratory-scale biological aerated filter (BAF) reactor, focusing on the biofilm during nitrification. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and microelectrode technology were utilized to evaluate the mechanisms associated with N2O production during wastewater treatment using BAF. Results indicated that the ability of N2O emission in biofilm at C/N ratio of 2 was much stronger than at C/N ratios of 5 and 8. PCR-DGGE analysis showed that the microbial community structures differed completely after the acclimatization at tested C/N ratios (i.e., 2, 5, and 8). Measurements of critical parameters including dissolved oxygen, oxidation reduction potential, NH4+-N, NO3--N, and NO2--N also demonstrated that the internal micro-environment of the biofilm benefit N2O production. DNA analysis showed that Proteobacteria comprised the majority of the bacteria, which might mainly result in N2O emission. Based on these results, C/N ratio is one of the parameters that play an important role in the N2O emission from the BAF reactors during nitrification.

Effect of copper on the performance and bacterial communities of activated sludge using Illumina MiSeq platforms.

The anaerobic-anoxic-aerobic (A2O) process is a highly efficient sewage treatment method, which uses complex bacterial communities. However, the effect of copper on this process and the bacterial communities involved remains unknown. In this study, a systematic investigation of the effect of persistent exposure of copper in the A2O wastewater treatment system was performed. An A2O device was designed to examine the effect of copper on the removal efficiency and microbial community compositions of activated sludge that was continuously treated with 10, 20, and 40 mg L(-1) copper, respectively. Surprisingly, a decrease in chemical oxygen demand (COD) and ammonia nitrogen (NH4N) removal efficiency was observed, and the toxicity of high copper concentration was significantly greater at 7d than at 1d. Proteobacteria, Bacteroidetes, Acidobacteria, Chlorobi, and Nitrospirae were the dominant bacterial taxa in the A2O system, and significant changes in microbial community were observed during the exposure period. Most of the dominant bacterial groups were easily susceptible to copper toxicity and diversely changed at different copper concentrations. However, not all the bacterial taxa were inhibited by copper treatment. At high copper concentration, many bacterial species were stimulated and their abundance increased. Cluster analysis and principal coordinate analysis (PCoA) based on operational taxonomic units (OTUs) revealed clear differences in the bacterial communities among the samples. These findings indicated that copper severely affected the performance and key microbial populations in the A2O system as well as disturbed the stability of the bacterial communities in the system, thus decreasing the removal efficiency.

[Planktonic Algae's Distribution and Correlation with Dissolved Organic Matters' Fluorescence in the End of the Three Gorges Reservoir's Back Water Zone].

For researching the community structure, composition, and distribution of the planktonic algae in the Three Gorges Reservoir (TRG), especially, within TRG water levels' fluctuating, mpacting to water quality with the algae's growing, 6 sampling cites in the end of the TGR's back water zone, from Chaotianmen to Taihonggang Town, are chosen to monitor, at the sensitive stages time of algal bloom between March to May 2012, namely, water levels lowing from the highest impounding. The community's structure, composition, and distribution of the planktonic algae in the TGR, and the correlation of water quality parameters and DOM's fluorescence features with algae density, are obtained. According to the experimental results, blue algae fibre, chlorella, melosira, navicula are the dominated algae in the end of the TGR's back water zone, from Chaotianmen to Taihonggang Town, algae density are 0.40~0.56 × 10(6), 1.9~0.8 × 10(6), 0.36~0.25 × 10(6), 0.42~0.15 × 10(6) cells · L(-1) respectively. Besides, anabaena, phormidium, cladophora, feather, ovate algae are existing in only limited 2 sections. The fitting results reveal obvious linear correlation of the EEM characteristics of DOM with the 4 kinds of dominated algal density, which could be useful conference for the algae bloom monitor, conveniently and effectively.

Vortex-assisted liquid-liquid microextraction using a low-toxicity solvent for the determination of five organophosphorus pesticides in water samples by high-performance liquid chromatography.

Vortex-assisted liquid-liquid microextraction followed by high-performance liquid chromatography with UV detection was applied to determine Isocarbophos, Parathion-methyl, Triazophos, Phoxim and Chlorpyrifos-methyl in water samples. 1-Bromobutane was used as the extraction solvent, which has a higher density than water and low toxicity. Centrifugation and disperser solvent were not required in this microextraction procedure. The optimum extraction conditions for 15 mL water sample were: pH of the sample solution, 5; volume of the extraction solvent, 80 µL; vortex time, 2 min; salt addition, 0.5 g. Under the optimum conditions, enrichment factors ranging from 196 to 237 and limits of detection below 0.38 µg/L were obtained for the determination of target pesticides in water. Good linearities (r > 0.9992) were obtained within the range of 1-500 µg/L for all the compounds. The relative standard deviations were in the range of 1.62-2.86% and the recoveries of spiked samples ranged from 89.80 to 104.20%. The whole proposed methodology is simple, rapid, sensitive and environmentally friendly for determining traces of organophosphorus pesticides in the water samples.

Long-term evolution of an activated sludge system under low dissolved oxygen conditions.

This study aims to evaluate the impacts of low dissolved oxygen (DO) levels on activated sludge performance. Two sequencing batch reactors (SBR), each with a working volume of 10 l, were investigated with different DO levels. Compared with high DO conditions (above 2 mg l(-1) on average), low DO conditions in the SBR did not result in poor sludge bulking, lower chemical oxygen demand, and ammonium removal efficiency. Moreover, simultaneous nitrification and denitrification (SND) via nitrite and shortcut nitrification-denitrification were carried out under low DO levels. The average efficiencies of SND and nitrite accumulation ratios (NAR) in reactors A and B were 10.6 and 60.4%, respectively, under high DO levels and 4.1 and 76%, respectively, under low DO levels. Scanning electron microscopy revealed that the main types of bacteria in reactor A were spherical and short rod-shaped bacteria, whereas those in reactor B were long rod-shaped bacteria and filamentous bacteria. Thus, the appropriate DO concentration created excellent microbial community structures, which helped the biological systems to perform well under low DO level operating conditions.