Genome instability-related LINC02577, LINC01133 and AC107464.2 are lncRNA prognostic markers correlated with immune microenvironment in pancreatic adenocarcinoma.

BACKGROUND: Pancreatic adenocarcinoma (PAAD) is a leading cause of malignancy-related deaths worldwide, and the efficacy of immunotherapy on PAAD is limited. Studies report that long non-coding RNAs (lncRNAs) play an important role in modulating genomic instability and immunotherapy. However, the identification of genome instability-related lncRNAs and their clinical significance has not been investigated in PAAD. METHODS: The current study developed a computational framework for mutation hypothesis based on lncRNA expression profile and somatic mutation spectrum in pancreatic adenocarcinoma genome. We explored the potential of GInLncRNAs(genome instability-related lncRNAs) through co-expression analysis and function enrichment analysis. We further analyzed GInLncRNAs by Cox regression and used the results to construct a prognostic lncRNA signature. Finally, we analyzed the relationship between GILncSig (genomic instability derived 3-lncRNA signature) and immunotherapy. RESULTS: A GILncSig was developed using bioinformatics analyses. It could divide patients into high-risk and low-risk groups, and there was a significant difference in OS between the two groups. In addition, GILncSig was associated with genome mutation rate in pancreatic adenocarcinoma, indicating its potential value as a marker for genomic instability. The GILncSig accurately grouped wild type patients of KRAS into two risk groups. The prognosis of the low-risk group was significantly improved. GILncSig was significantly correlated with the level of immune cell infiltration and immune checkpoint. CONCLUSIONS: In summary, the current study provides a basis for further studies on the role of lncRNA in genomic instability and immunotherapy. The study provides a novel method for identification of cancer biomarkers related to genomic instability and immunotherapy.

Ferroptosis-related differentially expressed genes serve as new biomarkers in ischemic stroke and identification of therapeutic drugs.

Background: Iron is an essential nutrient element, and iron metabolism is related to many diseases. Ferroptosis is an iron-dependent form of regulated cell death associated with ischemic stroke (IS). Hence, this study intended to discover and validate the possible ferroptosis-related genes involved in IS. Materials and methods: GSE16561, GSE37587, and GSE58294 were retrieved from the GEO database. Using R software, we identified ferroptosis-related differentially expressed genes (DEGs) in IS. Protein-protein interactions (PPIs) and enrichment analyses were conducted. The ROC curve was plotted to explore the diagnostic significance of those identified genes. The consistent clustering method was used to classify the IS samples. The level of immune cell infiltration of different subtypes was evaluated by ssGSEA and CIBERSORT algorithm. Validation was conducted in the test sets GSE37587 and GSE58294. Results: Twenty-one ferroptosis-related DEGs were detected in IS vs. the normal controls. Enrichment analysis shows that the 21 DEGs are involved in monocarboxylic acid metabolism, iron ion response, and ferroptosis. Moreover, their expression levels were pertinent to the age and gender of IS patients. The ROC analysis demonstrated remarkable diagnostic values of LAMP2, TSC22D3, SLC38A1, and RPL8 for IS. Transcription factors and targeting miRNAs of the 21 DEGs were determined. Vandetanib, FERRIC CITRATE, etc., were confirmed as potential therapeutic drugs for IS. Using 11 hub genes, IS patients were categorized into C1 and C2 subtypes. The two subtypes significantly differed between immune cell infiltration, checkpoints, and HLA genes. The 272 DEGs were identified from two subtypes and their biological functions were explored. Verification was performed in the GSE37587 and GSE58294 datasets. Conclusion: Our findings indicate that ferroptosis plays a critical role in the diversity and complexity of the IS immune microenvironment.

Advances in microbial electrochemistry-enhanced constructed wetlands.

Constructed wetland (CW) is an effective ecological technology to treat water pollution and has the significant advantages of high impact resistance, simple construction process, and low maintenance cost. However, under extreme conditions such as low temperature, high salt concentration, and multiple types of pollutants, some bottlenecks exist, including the difficulty in improving operating efficiency and the low pollutant removal rate. Microbial electrochemical technology is an emerging clean energy technology and has the similar structure and pollutant removal mechanism to CW. Microbial electrochemistry combined with CW can improve the overall removal effect of pollutants in wetlands. This review summarizes characterization methods of microbial electrochemistry-enhanced constructed wetland systems, construction methods of different composite systems, mechanisms of single and composite systems, and removal effects of composite systems on different pollutants in water bodies. Based on the shortcomings of existing studies, the potential breakthroughs in microbial electrochemistry-enhanced constructed wetlands are proposed for developing the optimization solution of constructed wetlands.

Superhydrophobic and Breathable Polyacrylonitrile/Silica/Perfluoroalkyl Ethyl Methacrylate Nanofiber Membranes Prepared by Solution Blow Spinning.

Hydrophobic and breathable nanofiber membranes have attracted considerable attention owing to their applications in various fields. In this study, we fabricated superhydrophobic and breathable nanofiber membranes using solution blow spinning. We optimized the spinning process parameters by analyzing their effects on the structure and properties of the nanofiber membranes. And the nanofiber membranes achieved superhydrophobicity through hydrophobic modification treatment. The average fiber diameter and pore size of the obtained membrane were 0.51 and 13.65 µm, respectively. The membranes exhibited superhydrophobicity, breathability, and mechanical properties: water vapor transmission of 12.88 kg/m2/day, air permeability of 10.97 mm/s, water contact angle of 150.92°, maximum tensile stress of 5.36 MPa, and maximum elongation at break of 12.27%. Additionally, we studied the impact of heat treatment on the nanofiber membranes. The membranes prepared in this study can be applied to protective garments, outdoor clothing, antifouling materials, etc. Because of its relatively higher production efficiency, solution blow spinning is a prospective method for producing functional nanofibers.

Formation Mechanism of Fibrous Web in the Solution Blowing Process.

Solution blowing (SB) is a widely reported technology that can be used to fabricate fibers at the micro- and nanoscale. To reveal the fibrous web formation mechanism in SB, we improved our previous melt blowing (MB) model to predict fibrous web structures. Then, we fabricated two samples and simulated the same number of virtual samples in the computer to verify the model. Thereafter, we measured the structural parameters including the fiber diameter, fiber orientation, basis weight, and pore size. Our model provides a good prediction of the fiber orientation and basis weight. However, the predicted fiber diameter was slightly smaller than the measured diameter. The experimental pore size distribution was also different from that in the simulated results. The model provides a virtual fabrication process to reveal a fibrous web formation mechanism and finds a similar distribution of these structural parameters between SB and MB.

Influence of chemical speciation on enrofloxacin degradation by UV irradiation: Kinetics, mechanism and disinfection by-products formation.

Fluoroquinolones (FQs) were frequently detected in aqueous environment. The UV irradiation have been reported as an efficient method for FQs degradation. This study investigated the influence of chemical speciation on enrofloxacin (ENR) photolysis process by UV irradiation. The results showed that chemical speciation of ENR significantly affected the photodegradation kinetics, and the highest degradation rate was observed in the zwitterion form. Presence of natural organic matter (NOM) and inorganic anions had different degrees of influences on ENR photodegradation for three chemical speciation of ENR. The contribution of 1O2 on ENR degradation in neutral and alkalinity condition was significantly higher than that in acidic condition. The cation and zwitterion of ENR was beneficial to the formation of trichloromethane (TCM) and haloacetonitrile (HAN) during the chlorination alone. Compared with the chlorination of ENR, the UV pretreatment respectively caused 4.06-fold and 3.14-fold decrease in TCM formation at acidic and neutral reaction condition during subsequent chlorination. Also the decrease in HAN formation at neutral and alkalinity condition was found after UV treatment followed by chlorination. The UV pretreatment caused higher yield of HAN in the subsequent chlorination at acidic condition than that at neutral and alkalinity condition. Through the UV pretreatment at neutral condition, the generated concentration of halonitromethane (HNM) reached the maximum value during the subsequent chlorination. Potential toxic risk analysis showed the toxicity decreased in zwitterion form of ENR, while toxicity increased in cationic and anionic form after UV irradiation pretreatment.

A Novel Constructed Wetland Combined with Microbial Desalination Cells and its Application.

Wastewater recycling can alleviate the shortage of water resources. Saline water is seldom treated with biological processes, and its recycling rate is low. Constructed wetland (CW) is a safe, economical, and ecological water treatment method. However, the saline water treatment performance of CW is not good. Microbial desalination cells (MDC) utilizing a bioelectrochemical approach achieve functions of desalination and power generation. In this study, MDC was used to strengthen CW to form a composite system, MDC-CW. Through optimization of design parameters, MDC-CW was applied in the treatment of salt-containing water. The average total nitrogen removal rate in MDC-CW-P1 reached 87.33% and the average COD removal rate was 92.79%. The average desalination rate of MDC-CW-P1 was 55.78% and the average voltage of MDC-CW-P1 reached 0.40 mV. Planting Canna indica in the MDC-CW was conducive to the functions of desalination and power generation. The above results were also verified by the microbial analysis results of gravels in the substrate, plant rhizosphere, and electrodes. In addition, the decontamination of the device mainly depended on the function of the bacteria commonly used in water treatment, such as Proteobacteria and Bacteroidetes, whereas the generation of power depended on the function of Geobacter. Salt ions moved spontaneously to the cathode and anode under the influence of current generation so that the desalination function was realized under the selective isolation function of exchange membranes. The device design and laboratory applications of MDC-CW experimentally achieved the electrochemical function and broadened the treatment scale of CW.

CLEC4s as Potential Therapeutic Targets in Hepatocellular Carcinoma Microenvironment.

Immunosuppressive tumor microenvironment in hepatocellular carcinoma (HCC) is critical in tumor development. C-type (Ca2+ -dependent) lectin (CLEC) receptors, essential in innate pattern recognition, have potential regulatory effects on immune cell trafficking and modulatory effects on cancer cell activity. However, information on the expression and prognostic value of CLECs in HCC is scanty. Herein, we explored the potential role of CLECs in HCC based on TCGA, ONCOMINE, GEPIA, UALCAN, cBioPortal, Metascape, TRRUST, and TIMER databases. Results demonstrated a significantly higher mRNA level of CLEC4A and CLEC4L in HCC tissues than normal liver tissues. Contrarily, we found significantly low CLEC4G/H1/H2/M expression in HCC tissues. The IHC analysis revealed the following: Absence of CLEC4A/J/K/M in normal and liver cancer tissues; high CLEC4C expression in HCC tissues; low expression and zero detection of CLEC4D/E/H1/H2/L in HCC tissues and normal tissues, respectively. And the HepG2 and LX-2 were used to verify the expression level of CLEC4s via qRT-PCR in vitro. Furthermore, the expression of CLEC4H1 (ASGR1) and CLEC4H2 (ASGR2) exhibited a significant relation to clinical stages. However, the expression of CLEC4A, CLEC4D, CLEC4E, CLEC4J (FCER2), CLEC4K (CD207), CLEC4G, CLEC4H1, CLEC4M, and CLEC4H2 decreased with tumor progression. Patients expressing higher CLEC4H1/H2 levels had longer overall survival than patients exhibiting lower expression. Moreover, CLEC4A/D/E/J/K/G/H1/M/H2 had significant down-regulated levels of promoter methylation. The expression level of CLEC4s was correlated with the infiltration of B cells, CD8 + T cells, CD4 + T cells, macrophage cells, neutrophil cells, and dendritic cells. Functional analysis revealed the potential role of CLECL4s in virus infection, including COVID-19. Also, hsa-miR-4278 and hsa-miR-324-5p, two potential miRNA targets of CLEC4s, were uncovered. This article demonstrates that CLEC4 is crucial for the development of HCC and is associated with infiltration of various immune cells, providing evidence for new immunotherapy targets in HCC.

Identification of key pathways and genes in carotid atherosclerosis through bioinformatics analysis of RNA-seq data.

While acknowledging carotid atherosclerosis (CAS) as a risk factor for ischemic stroke, reports on its pathogenesis are scarce. This study aimed to explore the potential mechanism of CAS through RNA-seq data analysis. Carotid intima tissue samples from CAS patients and healthy subjects were subjected to RNA-seq analysis, which yielded, 1,427 differentially expressed genes (DEGs) related to CAS. Further, enrichment analysis (Gene Ontology, KEGG pathway, and MOCDE analysis) was performed on the DEGs. Hub genes identified via the protein-protein interaction network (PPI) were then analyzed using TRRUST, DisGeNET, PaGenBase, and CMAP databases. Results implicated inflammation and immunity in the pathogenesis of CAS. Also, lung disease was associated with CAS. Hub genes were expressed in multiple diseases, mainly regulated by RELA and NFKB1. Moreover, three small-molecule compounds were found via the CMAP database for management of CAS; hub genes served as potential targets. Collectively, inflammation and immunity are the potential pathological mechanisms of CAS. This study implicates CeForanide, Chenodeoxycholic acid, and 0317956-0000 as potential drug candidates for CAS treatment.

Identification of key genes in lung adenocarcinoma based on a competing endogenous RNA network.

Lung adenocarcinoma (LUAD) is the most commonly diagnosed type of lung cancer and exhibits a high morbidity. The present study aimed to investigate the long non-coding RNA (lncRNA)-associated competing endogenous RNA (ceRNA) mechanisms in LUAD. The receptor activity modifying protein 2-antisense RNA 1 (RAMP2-AS1) was identified using GSE113852 and GSE130779 datasets downloaded from the Gene Expression Omnibus database, and the downregulation of RAMP2-AS1 was the most significant in LUAD. In addition, microRNA (miR)-296-5p was identified to bind to RAMP2-AS1 via bioinformatics analysis. Subsequently, CD44, cyclin D3 (CCND3), neurocalcin δ (NCALD), microtubule actin crosslinking factor 1 (MACF1) and potassium channel tetramerization domain containing 15 were obtained by intersecting the predicted target genes of miR-296-5p and 368 differentially expressed mRNAs in LUAD. According to the Gene Expression Profiling Interactive Analysis and UALCAN databases, these five mRNAs were downregulated in LUAD, and their expression levels were positively correlated with those of RAMP2-AS1. CD44, CCND3, NCALD and MACF1 were selected as key mRNAs in LUAD based on prognostic analyses. Furthermore, functional enrichment analyses were performed and an interaction network was constructed to reveal the functions of the RAMP2-AS1-associated ceRNA in LUAD. The results indicated that the functions were mainly enriched in generic transcription pathways, cyclin D-associated events in G1 and epithelial stromal transformation. Reverse transcription-quantitative PCR assays revealed that RAMP2-AS1, CD44, CCND3, NCALD and MACF1 expression was lower in tumor tissues than in normal tissues, while miR-296-5p expression was higher in tumor tissues compared with in normal tissues. The association between RAMP2-AS1 and MACF1 was further confirmed using in vitro experiments. Overall, the present results indicated that RAMP2-AS1, miR-296-5p, CD44, CCND3, NCALD and MACF1 may be involved in LUAD progression and may therefore serve as potential biomarkers and provide a theoretical basis for the study of the pathogenesis of LUAD.

Long Noncoding RNA ADAMTS9-AS2 Inhibits the Proliferation, Migration, and Invasion in Bladder Tumor Cells.

BACKGROUND: Bladder tumor is the fifth most prevalent tumor in men, yet its pathogenesis remains to be fully identified. Albeit a host of long noncoding RNAs (lncRNA) are emerging as new players involved in bladder tumor, the functions of many lncRNAs are still enigmatic. Reports on the deluge of studies on lncRNA ADAMTS9-AS2 have been convincingly associated with various tumors, but without mention of its roles in bladder tumor. Therefore, the roles of ADAMTS9-AS2 in bladder tumor cells were explored in our study. MATERIALS AND METHODS: Quantitative real-time PCR assays and bioinformatic tools were applied in bladder tumor cells to identify the ADAMTS9-AS2 and ADAMTS9 expression. Western blot assays were performed to obtain the protein levels of bladder tumor related key molecules. CCK8, clonogenic assay, scratch wound healing, and transwell assays were separately applied to identify the functional roles of ADAMTS9-AS2 on proliferation, migration, and invasion in bladder tumor cells. RESULTS: First, ADAMTS9-AS2 downregulation in bladder tumor cells was identified. Overexpression and knockdown experiments showed that ADAMTS9-AS2 expression was positively related to ADAMTS9, which is in accordance with the results from GEO database. Second, ADAMTS9-AS2 contributed to the inhibition of proliferation, migration, and invasion in bladder tumor cells. Third, ADAMTS9-AS2 was linked with PI3K/AKT/mTOR pathway related-molecules, several key autophagy, and apoptotic proteins. CONCLUSION: Conjointly, our findings suggested that ADAMTS9-AS2 might function as a tumor suppressor to restrain the proliferation, migration, and invasion in bladder tumor cells. The potential mechanism of ADAMTS9-AS2 related to PI3K/AKT/mTOR signal pathway was further identified. Of note, we found that ADAMTS9-AS2 has a significant effect on several key autophagy and apoptotic proteins. Therefore, these observations will provide supportive evidence to ADAMTS9-AS2 as a potential biomarker in patients with bladder tumor.

Polytetrafluoroethylene/Polyphenylene Sulfide Needle-Punched Triboelectric Air Filter for Efficient Particulate Matter Removal.

The demand for air filtration materials in recent years has been substantially increasing on a worldwide scale because people are paying extensive attention to particulate matter (PM) pollution. In this work, we report a type of needle-punched triboelectric air filter (N-TAF) consisting of polytetrafluoroethylene (PTFE) fibers modified by silica nanoparticles and polyphenylene sulfide (PPS) fibers. Compared to conventional electrostatic precipitators, the N-TAF can be charged online by a unique nonwoven processing technology without additional energy consumption and toxic ozone emission. Owing to the triboelectrification effect, a large number of charges were generated during the process of carding and needle-punching, resulting in an increased filtration performance. Benefiting from the addition of silica nanoparticles, the PTFE fibers are endowed with many pores and grooves and substantial surface roughness, which contributes to the enhancement of triboelectrification. As a result, the N-TAF with 2 wt % silica nanoparticles (N-TAF-2) exhibited a high removal efficiency of 89.4% for PM, which is 45% higher than unmodified N-TAF (61.8%), and a low pressure drop of 18.6 Pa. Meanwhile, the decay of the removal efficiency for N-TAF-2 remained at a low level (6.4%) for 60 days. More importantly, N-TAF-2 could realize a high efficiency of 99.7% and a low pressure drop of 55.4 Pa at a high surface density. In addition, the washed N-TAF has an excellent charge regeneration performance via air blowing or manual rubbing, thus recovering the removal efficiency easily and rapidly. Ultimately, the powerful dust holding capacity (227 g m-2) for N-TAF-2 indicates that the filter has a long service life, which makes it a promising air purification material. The filter reported in this work has the potential to be practically applied to air purification fields because it has excellent filtration performance and is easy to be produced on a large industrial scale.

Influences of Iron Compounds on Microbial Diversity and Improvements in Organic C, N, and P Removal Performances in Constructed Wetlands.

The effects of various combinations of iron compounds on the contaminant removal performance in constructed wetlands (CWs) were explored under various initial iron concentrations, contaminant concentrations, different hydraulic retention time (HRT), and different temperatures. The Combo 6 (nanoscale zero-valent iron combined with Fe3+) in CW treatments showed the highest pollutant removal performance under the conditions of C2 initial iron dosage concentration (total iron 0.2 mM) and I2 initial contaminant concentration (COD:TN:TP = 60 mg/L:60 mg/L:1 mg/L) in influent after 72-h HRT. These results were directly verified by two different microbial tests (Biolog test and high-throughput pyrosequencing) and microbial community analysis (principal component analysis of community-level physiological profile, biodiversity index, cluster tree, relative abundance at order of taxonomy level). Specific bacteria related to significant improvements in contaminant removal were domesticated by various combinations of iron compounds. Iron dosage was advised as a green, new, and effective option for wastewater treatment. Graphical Abstract .

Time-Dependent Toxicities of Quorum Sensing Inhibitors to Aliivibrio fischeri and Bacillus subtilis.

Quorum sensing inhibitors (QSIs) are being used widely as a promising alternative to antibiotics and drawing attention as potential pollutants. However, the assessment methods of the toxicities of QSIs, including model organism and affecting time, have not been established. To investigate how model organism and acting time impact the toxicities of QSIs, the effect of 4 QSIs to Aliivibrio fischeri and Bacillus subtilis were determined at different exposing time in the present study. The results showed that the toxic effects of QSIs to gram-negative bacteria (A fischeri) and gram-positive bacteria (B subtilis) were different and time dependent. As for A fischeri, QSI (furaneol acetate, FA) merely showed inhibition on the bioluminescence from hours 1 to 2. But from hours 3 to 6, low concentration FA exerted stimulation on the bioluminescence. Then, this stimulation disappeared from hours 7 to 14, and after hour 15 the stimulation appeared again. That is to say, QSIs showed intermittent hormesis effect on the bioluminescence of A fischeri. By contrast, only inhibition was observed in the toxicity test process of QSIs to B subtilis. As exposing time goes, the inhibition weakened gradually when FA was at low concentration regions. What is more, in the present, study toxic mechanisms were also discussed based on model organisms and exposing time. This study demonstrates appreciable impacts of model organism and exposing time on toxicities of QSIs and provides a theoretical basis for risk assessments after QSIs being widely used into the environment.

Montmorillonite supported nanoscale zero-valent iron immobilized in sodium alginate (SA/Mt-NZVI) enhanced the nitrogen removal in vertical flow constructed wetlands (VFCWs).

Lacking of electron donor generally causes the low denitrification performance of constructed wetlands (CWs). Montmorillonite supported nanoscale zero-valent iron immobilized in sodium alginate (SA/Mt-NZVI) as novel electron donor-acceptor compounds were added in the denitrification zone of vertical flow constructed wetlands (VFCWs) to enhance the nitrogen removal. The key factors of the SA/Mt-NZVI dosage, the hydraulic retention time (HRT) of VFCWs, and the C/N ratios of influent were explored. SA/Mt-NZVI significantly improved the nitrogen (NO3--N) removal efficiency in VFCWs. When the optimal dosage of SA/Mt-NZVI was set as 2 g and the C/N was set as 6, the highest NO3--N removal efficiency was improved by 32.5 ±â€¯1.0%. The microbial community analysis of by 16S rRNA had revealed that Proteobacteria and Bacteroidetes at phylum level and Betaproteobacteria, Gammaproteobacteria, and Alphaproteobacteria at class level played an important role in nitrogen removal.

Environmentally friendly and breathable wet-laid hydroentangled nonwovens for personal hygiene care with excellent water absorbency and flushability.

Developing wet-laid papers with a good wet strength remains a longstanding challenge in the papermaking industry. In this study, hydroentanglement, a mechanical bonding technique is developed to consolidate the wet-laid fibre web. The results indicate that wet tensile strength, ductile stretching property, softness, air permeability and water absorbency of the wet-laid fibre web are significantly improved by hydroentanglement. In addition, the abrasion test shows that the dusting off rate of wet-laid fibre web can be effectively reduced through hydroentanglement. Moreover, the disintegration experiment proves that wet-laid hydroentangled nonwovens could be easily dispersed when compared with conventional carded hydroentangled nonwovens. Therefore, the new wet-laid hydroentangled nonwovens can maintain excellent performance in a wet state, showing a great potential for personal hygiene applications.

Effects of iron and calcium carbonate on contaminant removal efficiencies and microbial communities in integrated wastewater treatment systems.

In the paper, we explored the influences of different dosages of iron and calcium carbonate on contaminant removal efficiencies and microbial communities in algal ponds combined with constructed wetlands. After 1-year operation of treatment systems, based on the high-throughput pyrosequencing analysis of microbial communities, the optimal operating conditions were obtained as follows: the ACW10 system with Fe3+ (5.6 mg L-1), iron powder (2.8 mg L-1), and CaCO3 powder (0.2 mg L-1) in influent as the adjusting agents, initial phosphorus source (PO43-) in influent, the ratio of nitrogen to phosphorus (N/P) of 30 in influent, and hydraulic retention time (HRT) of 1 day. Total nitrogen (TN) removal efficiency and total phosphorus (TP) removal efficiency were improved significantly. The hydrolysis of CaCO3 promoted the physicochemical precipitation in contaminant removal. Meanwhile, Fe3+ and iron powder produced Fe2+, which improved contaminant removal. Iron ion improved the diversity, distribution, and metabolic functions of microbial communities in integrated treatment systems. In the treatment ACW10, the dominant phylum in the microbial community was PLANCTOMYCETES, which positively promoted nitrogen removal. After 5 consecutive treatments in ACW10, contaminant removal efficiencies for TN and TP respectively reached 80.6% and 57.3% and total iron concentration in effluent was 0.042 mg L-1.

[Annual dynamics of cladocera community structure in Backshore Wetland of Expo Garden, Shanghai].

The Backshore Wetland of Expo Garden, Shanghai was one of the key parts of the World Expo construction project in 2010. From September 2009 to August 2010, a monthly investigation was conducted to understand the spatiotemporal dynamics of cladocera community structure (including species composition and standing crop) and related main affecting factors in the Backshore Wetland. A total of 36 cladocera species in 13 genera of 5 families were identified through the year. There were 12 dominant species, mainly Chydorus sphaericus, C. ovalis, Diaphanosoma leuchtenbergianum, and Sida crystalline. The mean annual abundance and biomass of the cladocera were 5.7 ind x L(-1) and 0.3559 mg x L(-1), respectively, and the annual dynamics of the standing crop showed bimodal, with the main peak in April and July, and the second peak in July and May, respectively. The Shannon index, Pielou index, and Margelf index were high in summer and autumn, but low in winter and spring. The canonical correspondence analysis (CCA) showed that water temperature, pH, dissolved oxygen, and nitrite nitrogen were the main factors affecting the community structure of cladocera in the Backshore Wetland.

[Response of copepod community characteristics to environmental factors in the Backshore Wetland of Expo Garden, Shanghai].

The Backshore Wetland of Expo Garden was the emphasis of the World Expo construction project in Shanghai in 2010, China programming district. We carried out studies on the community structure and spatial-temporal variation of copepod from September 2009 to August 2010. Statistical Product and Service Solutions (SPSS) was used for relevant statistical analysis between physicochemical parameters and copepod standing crop. Canonical correspondence analysis (CCA) was applied to further explore the correlation between copepod species and environmental parameters using CANOCO 4.5. A total of 23 copepod species in 11 genera, 6 families were identified. 5 dominant species of copepod were recorded during the survey period. They were Eucyclops serrulatus, Thermocyclops taihokuensis, Mesocyclops leuckarti, Thermocyclops brevifurcatus and Microcyclops varicans. The annual mean density of copepod was (8.6 +/- 16.6) ind x L(-1) and the biomass was (0.083 6 +/- 0.143 1) mg x L(-1). The standing crop of copepod had its first peak in July, the second in October and the bottom in January. The highest trophic level was measured at Site 1, decreasing along the flowing direction of the water current, and the lowest level was found at Site 10. The Margelf index remained low in winter and spring, but was increased in summer and autumn. The community structure of copepod was analyzed in relation to water quality parameters by canonical correspondence analysis (CCA). Water temperature, pH, nitrate nitrogen, nitrite nitrogen, TN, TP and dissolved oxygen were strongly correlated with the copepod community structure.