Temperature measurements of a wearable and wireless axillary sensor iThermonitor but not a bladder probe represents the core temperature during laparoscopic rectal surgery.

OBJECTIVE: To investigate whether the temperature recorded by an iThermonitor has better concordance with the core temperature than the bladder temperature recorded by a Foley catheter sensor in laparoscopic rectal surgery. METHODS: Eighty-two adults undergoing laparoscopic rectal surgery were enrolled. Temperatures were continuously measured by a distal oesophageal probe (the reference core temperature), axillary iThermonitor and Foley catheter sensor (bladder temperature) in each patient during surgery. Pairs of axillary and core temperatures or pairs of bladder temperature and core temperatures were compared and summarized using linear regression and the repeated-measured Bland-Altman method during the whole surgical period and pneumoperitoneum period. RESULTS: There were 3303 pairs of temperature measurements during the whole surgical period. The mean difference between iThermonitor and oesophageal was 0.05 °C ; the limits of agreement were - 0.48 to 0.56 °C. The mean difference between the oesophagus and bladder was 0.28 °C; the limits of agreement were - 0.39 to 0.94 °C (P < 0.001, F-test vs. iThermonitor). Ninety -five% of all iThermonitor values were within 0.5 °C of oesophageal temperature, whereas the proportion for oesophageal and bladder differences within 0.5 °C was only 84% (95% confidence interval 80-88%). Lin's CCC for the iThermonitor and bladder measurements were 0.842 (95%CI: 0.831-0.851) and 0.688 (95%CI: 0.673-0.703) respectively. Similar results were found during the pneumoperitoneum period. CONCLUSIONS: The temperature recorded by iThermonitor has better concordance with the core temperature than the bladder temperature recorded by Foley catheter sensor in laparoscopic rectal surgery.

Response of the common reed (Phragmites australis) to nutrient enrichment depends on the growth stage and degree of enrichment: A mesocosm experiment.

Human-induced nutrient enrichment is a major stressor in aquatic ecosystems that has resulted in the alteration of ecosystem structures and functions. However, to date, relatively few studies have explored the temporal dynamics of reed biomass and morphological and biochemical traits under different nutrient levels, as well as the phenological pattern. Based on a mesocosm experiment, we monitored the aboveground and underground biomass of reed at the different plant growth stages, along with plant height, ramet and leaf number, leaf length and width, and carbohydrate and nutrient contents in different organs. We found that the significantly different ratio of aboveground to underground biomass was only observed at the late flowering stage between the slight enrichment (S-E) and heavy enrichment (H-E) groups. The start of the fast-growth phase of the aboveground part and underground part was delayed in the higher nutrient enrichment groups. The length of the fast-growth phase of the aboveground part was the same in the medium enrichment (M-E) and H-E groups and longer than that in the S-E group. For the underground part, the longest fast-growth phase was found in the S-E group (105 days), followed by the H-E and M-E groups (46 and 41 days, respectively). As the nutrient level increased, both increased and decreased values were observed for the 29 monitored morphological and biochemical traits, and the magnitude changed with the different growth stages. Moreover, different degrees of nutrient enrichment could differentially enhance or weaken the relationships among the groups between total biomass and the integrated morphological trait, between structural carbohydrate (SC) and total nitrogen (TN) contents, between total organic carbon (TOC) and TN, between total phosphorus (TP) contents, between TOC and SC contents. Our findings highlight a crucial contribution of ambient nutrient supply to temporal variation in plant biomass and phenological, morphological and biochemical traits.

Facile Synthesis of Magnetic Biochar Derived from Burley Tobacco Stems towards Enhanced Cr(VI) Removal: Performance and Mechanism.

In this study, ferric-loaded magnetic burley tobacco stem biochar (MBTS) was synthesized via pyrolysis to improve the removal of Cr(VI). The results showed that MBTS had an adsorption capacity of 54.92 mg Cr(VI)/g, which was about 14 times higher than raw burley tobacco stem biochar (i.e., 3.84 mg/g). According to the findings obtained, a three-step mechanism of Cr(VI) removal by MBTS was further put forward, i.e., (1) Cr(VI) exchanged with hydroxyl groups on MBTS, (2) the reduction in Cr(VI) to Cr(III) mediated by oxygen-containing groups, and (3) the chelation of produced Cr(III) with the amino groups on MBTS. FTIR spectra further revealed that C-N, C-H, and C=C groups played an important role in Cr(VI) removal. Furthermore, the adsorption equilibrium and kinetics of Cr(VI) on MBTS could better be described by the Langmuir equation and pseudo-second-order rate equation. This study clearly demonstrated that ferric-loaded biochar derived from burley tobacco stems could serve as a cost-effective magnetic adsorbent for the high-efficiency removal of soluble Cr(VI) from wastewater. Tobacco stem-adsorbed Cr(VI) realized a green path for treating waste by waste.

Physiological Responses and Phytotoxicities of Lythrum salicaria to Decabromodiphenyl Ether (BDE-209).

Decabromodiphenyl ether (BDE-209), a member of a major group of brominated flame retardants, is detected in aquatic environments at considerable levels and induces physiological and toxic effects on aquatic plants. In this study, the physiological responses induced by and the toxic effects of BDE-209 at different concentrations (0, 0.2, 0.5 and 1.0 mg L-1) in Lythrum salicaria were examined. OJIP transient curves indicated that BDE-209 treatment negatively affected photosystem II (PSII) grouping. Additionally, the results showed that BDE-209 inhibited seedling development and elevated reactive oxygen species (ROS), phosphorylated histone H2AX (γ-H2AX), malondialdehyde (MDA) levels and antioxidative enzyme activities in the roots and shoots of L. salicaria. The results revealed that BDE-209 exposure contributed to ROS accumulation, which was considered as the probable toxicity mechanism. The current results provided an insight into the development of L. salicaria with high BDE-209 tolerance.

Effects of macrophytes on ecosystem metabolism and net nutrient uptake in a groundwater fed lowland river.

Transport and transformation of inorganic nutrients are influenced by abiotic-biotic interactions and determine downstream water quality. Macrophytes play an important role in these complex ecological interactions. The role of macrophytes was studied in three reaches of the groundwater-fed, oligotrophic River Fischa with different macrophyte coverage and biomass. This was done by measuring metabolism and calculating changes in nutrient loading and concentrations, which were determined via an upstream-downstream mass balance approach. As the dominant autotrophs, we expected macrophytes (i) to have a direct effect by uptake and release, and (ii) an indirect effect by slowing down flow, which results in changed sedimentation patterns and altered conditions for heterotrophic microbial organisms implicating higher turnover and uptake rates. The seasonal development of macrophytes in 2017 had a strong impact on gross primary production, but not on ecosystem respiration. Increase in macrophyte biomass led to higher GPP (max. 5.4 g O2m-2d-1). ER was highest in autumn in the reach with intermediate macrophyte biomass (max. 10.1 g O2m-2d-1). We observed that the autotrophic uptake of phosphorus accounted for 80-145% of the P-PO4-flux and concluded that P-uptake by macrophytes from the sediment is an important source of phosphate for macrophytes in the river. By accumulating fine sediment, macrophytes are improving the availability of phosphate for their own long-term development. N-NO3, represented >99% of the nitrogen flux. N-NO3 net uptake was higher in the reaches with more macrophytes (0.84 vs. 0.12 g m-2d-1), but in average only 21% of the net uptake could be related to autotrophic nitrogen uptake in the reach with high macrophyte biomass. Dissimilatory uptake by heterotrophic organisms, most probably denitrification, were of high relevance. Macrophytes supported microbial uptake and release by improving conditions and slowing down flow. In the River Fischa, an oligotrophic river with low variability of environmental parameters, macrophytes greatly affected nutrient uptake by direct and indirect pathways.

Influence of water temperature and water depth on macrophyte-bacterioplankton interaction in a groundwater-fed river.

Biotic interactions shape the community structure and function of ecosystems and thus play an important role in ecosystem management and restoration. To investigate how water temperature (related to the season) and water depth (related to spatial patterns of river morphology) affect macrophyte-bacterioplankton interactions in a groundwater-fed river, we conducted the structural equation modeling on datasets grouped by hydrological conditions. In addition to direct effects on macrophyte growth and/or bacterioplankton development, water temperature and water depth could both regulate the role of different nutrients (inorganic and organic) on affecting these biological indicators. Deeper water depth intensified the positive relationship between macrophytes and bacterioplankton, while higher temperature switched the relationship from being positive to negative. Our study provides empirical evidences that abiotic variables, even with relatively low fluctuations, play a critical role in regulating the patterns and strengths of interaction between macrophytes and bacterioplankton.

Treatment performance and microbial response to dibutyl phthalate contaminated wastewater in vertical flow constructed wetland mesocosms.

Phthalic acid esters (PAEs), especially dibutyl phthalate (DBP) pollution in the environment, have attracted worldwide attention. Four Phragmites australis-based, mesocosm-scale vertical flow constructed wetlands (VFCWs) with different hydraulic loading rates (HLRs) were operated for one year to study the removal efficiency and mechanisms of DBP in the reclaimed water. The average removal efficiencies for DBP were 93.77 ± 3.27%, 94.9 ± 2.60% and 97.0 ± 3.00% in the VFCWs under HLRs of 0.33, 0.22 and 0.11 m/d, respectively. DBP can be accumulated and degraded by wetland plants and its concentration in the roots (0.256-8.45 mg/kg) were higher than in the leaves (0.243-0.482 mg/kg). The concentrations of primary and secondary metabolites mono-n-butyl phthalate (MBP) and phthalic acid (PA) were 0.142-2.35 mg/kg and 0.113-0.545 mg/kg respectively in the plant tissues. The concentrations of DBP were 38.2-271 µg/kg in the substrates. Mass balance for DBP indicates that the estimated plant uptake and substrate adsorption of total DBP is negligible. This suggests that biodegradation and other process are the primary pathways for DBP removal in VFCWs. The results of 16S rDNA and ITS rDNA high-throughput sequencing indicated that both bacterial and fungal community diversity decreased with the exposure of DBP. Janthinobacterium, Flavobacterium and Curvularia genera may be the main participants in the biodegradation of DBP in the CWs.

Responses of water quality and phytoplankton assemblages to remediation projects in two hypereutrophic tributaries of Chaohu Lake.

Water shortages and the presence of point and diffuse source pollution have caused a serious deterioration in water quality in two tributaries (the Tangxi River and Shiwuli River) of Chaohu Lake, China. To reduce nutrient pollution and suppress harmful algal blooms (HABs), hard engineering and ecological remediation projects were implemented. A post-project investigation from 2013 to 2016 was carried out to evaluate the outcome of the remediation projects by monitoring the seasonal and spatial variations in water quality and the phytoplankton community. In the Tangxi River, the average total phosphorus (TP) concentrations in the four seasons were below 0.5 mg L-1, with the lowest concentration (0.29 ±â€¯0.12 mg L-1) found in autumn. Remediation measures including sediment dredging, riparian buffer zone creation, downstream wetland park construction, and water augmentation using reclaimed water and filtered lake water might combine to promote P source mitigation. Moreover, the percentage of bloom-forming cyanobacteria (i.e., Microcystis, Aphanizomenon, Anabaena, Oscillatoria, Phormidium and Planktothrix) in the phytoplankton assemblage and the biomass of the dominant species indicated successful HAB control. In the Shiwuli River, water quality improvements and phytoplankton responses have been observed since 2015 after the upgrading of a local wastewater treatment plant (WWTP) with effluent that was used for flow augmentation. Nevertheless, there is still room for improvement via increasing the river self-purification ability (e.g., the creation of downstream wetlands and riparian buffer zones) and promoting water augmentation according to the experience gained in the remediation projects of the Tangxi River.

Removal efficiency and enzymatic mechanism of dibutyl phthalate (DBP) by constructed wetlands.

Four vertical-flow constructed wetland systems were set up in the field in order to study the removal efficiency and possible enzymatic mechanism of the constructed wetlands in treating sewage containing different concentrations of dibutyl phthalate (DBP). Under DBP spiked concentrations of 0.5, 1.0, and 2.0 mg/L, good DBP removal rates of 62.08, 82.17, and 84.17% were achieved, respectively. Meanwhile, certain removal effects of general water quality parameters were observed in all four constructed wetlands: with high average removal rates of nitrate nitrogen (NO3--N) and chemical oxygen demand (COD) of 91.10~93.89 and 82.83~89.17%, respectively, with moderate removal efficiencies of total nitrogen (TN), total phosphorus (TP), ammonia nitrogen (NH4+-N) of 44.59~49.67, 30.58~37.18, and 28.52~37.45%, respectively. Compared to the control, an increase of enzyme activities of urease, phosphatase, dehydrogenase, and nitrate reductase was observed in the treatments with DBP addition. In the presence of 0.5 mg/L of DBP concentration, the urease, phosphatase, and dehydrogenase activities reached the highest levels, with an increase of 350.02, 36.57, and 417.88% compared with the control, respectively. It appeared that the low concentration of DBP might better stimulate the release of enzymes.

Influence of nitrogen loading and flooding on seedling emergence and recruitment from a seed bank in Chaohu Lake Basin, China.

Vegetation severely degraded and even disappeared in the water bodies of Chaohu Lake basin, which is the fifth largest freshwater lake in the Yangtze flood plain in China, because of water pollution and eutrophication. Vegetation restoration projects have been carried out. However, the influences of water quality and hydrology on vegetation restoration from seed banks have been rarely investigated. This experiment aimed to identify the effect of water level and nitrogen loading (ammonium and nitrate) on seedling emergence and recruitment from the riparian seed bank of the river in this basin. Most of the species in the seed bank germinated under moist conditions. Under flooding conditions, however, the growth of aquatic species, especially Vallisneria natans (Lour.) Hara, was inhibited when the nitrogen concentration increased. At 0.37 mg/L NH4+-N in the water column, the growth of V. natans was inhibited. The results suggested that flooding was a primary limiting factor of seedling emergence. The inhibitory effect of high nitrogen loading on the growth of aquatic species was one of the main driving mechanisms of macrophyte degradation under flooding conditions; nevertheless, competitive advantage might determine the community pattern in moist habitats. Therefore, water level control and water quality improvement should be the key aspects of vegetation restoration in degraded rivers or lakes.

Triazophos (TAP) removal in horizontal subsurface flow constructed wetlands (HSCWs) and its accumulation in plants and substrates.

Triazophos (TAP) is a widely used phosphorus pesticide in China that possesses a potential risk for water pollution. We have studied the removal efficiency of TAP using pilot-scale horizontal subsurface flow constructed wetlands (HSCWs) as well as the contribution of plants, substrates and other pathways to its removal. For TAP concentrations of 0.12 ± 0.04 mg L-1, 0.79 ± 0.29 mg L-1 and 3.96 ± 1.17 mg L-1, the removal efficiencies were 94.2 ± 3.7%, 97.8 ± 2.9% and 84.0 ± 13.5%, respectively, at a hydraulic loading rate (HLR) of 100 mm d-1; at an HLR of 200 mm d-1, the removal efficiencies were 96.7 ± 1.3%, 96.2 ± 1.7% and 61.7 ± 11.1%, respectively. The isopleth maps of TAP along the direction of flow indicate that most of the TAP removal occurred in the front and middle regions, while the major removal region would move forward with increasing influent TAP. Plant and substrate accumulation accounted for 0.035 ± 0.034% and 4.33 ± 0.43% of the total removal, respectively, indicating that over 95% of the TAP removal was achieved through other mechanisms. Thus, these results suggest HSCWs can be an effective approach with which to treat TAP contaminated water. Furthermore, the longitudinal scale and hydraulic conditions, as well as the roles of plants, substrates and microbes and their interactions, should be further considered in the design and application of CWs for pesticide pollution control.

Seasonal variation of microbial community for the treatment of tail water in constructed wetland.

Effects of seasons and hydraulic loading rates (HLR) on the treatment performance and the response of the microbial community of vertical flow constructed wetland treating tail water were investigated. The seasonal treatment performance was evaluated at four HLR of 125, 250, 375 and 500 mm/d, respectively. The microbial community was detected by MiSeq Illumina platform at HLR 125 and 375 mm/d. The wetland showed significantly higher chemical oxygen demand (COD) and total nitrogen (TN), total phosphorus (TP) at HLR 125 mm/d, compared with other HLR. Overall removal efficiency was 61.47%, 71.40% and 76.31% for COD, TN and TP, respectively, while no significant differences for COD, TN and TP removal were found at HLR of 250, 375 and 500 mm/d. The best removal efficiency for COD and TN was achieved in summer and autumn, while the best TP removal was achieved in winter. Nitrification bacteria (Nitrosomonas and Nitrospira) were significantly higher in HLR 125 mm/d, whereas sequences associated with denitrification had no significant difference at the two HLR. The results can partially explain the significantly higher NH4+-N removal in HLR 125 mm/d and relatively low nitrogen performance in winter.

Increasing phytoplankton-available phosphorus and inhibition of macrophyte on phytoplankton bloom.

We assembled mesocosms to address the coherent mechanisms that an increasing phosphorus (P) concentration in water columns coupled with the phytoplankton bloom and identify the performance gap of regulating phytoplankton growth between two macrophyte species, Ceratophyllum demersum L. and Vallisneria spiralis L. Intense alkaline phosphatase activities (APA) were observed in the unplanted control, with their predominant part, phytoplankton APA (accounting for up to 44.7% of the total APA), and another large share, bacterial APA. These correspond with the large average concentration of total phosphorus (TP), total dissolved phosphorus (TDP) and soluble reactive (SRP) as well as high phytoplankton density in the water column. The consistency among P concentrations, phytoplankton density and APA, together with the positive impact of phytoplankton density on total APA revealed by the structural equation modelling (SEM), indicates that facilitated APA levels in water is an essential strategy for phytoplankton to enhance the available P. Furthermore, a positive interaction between phytoplankton APA and bacteria APA was detected, suggesting a potential collaboration between phytoplankton and bacteria to boost available P content in the water column. Both macrophyte species had a prominent performance on regulating phytoplankton proliferation. The phytoplankton density and quantum yield in C. demersum systems were all significantly lower (33.8% and 24.0%) than those in V. spiralis systems. Additionally, a greater decoupling effect of C. demersum on the relationship between P, APA, phytoplankton density, bacteria dynamic and quantum yield was revealed by SEM. These results imply that the preferred tactic of different species could lead to the performance gap.

Biological mechanisms associated with triazophos (TAP) removal by horizontal subsurface flow constructed wetlands (HSFCW).

Triazophos (TAP) is a widely used pesticide that is easily accumulated in the environment due to its relatively high stability: this accumulation from agricultural runoff results in potential hazards to aquatic ecosystems. Constructed wetlands are generally considered to be an effective technology for treating TAP polluted surface water. However, knowledge about the biological mechanisms of TAP removal is still lacking. This study investigates the responses of a wetland plant (Canna indica), substrate enzymes and microbial communities in bench-scale horizontal subsurface-flow constructed wetlands (HSCWs) loaded with different TAP concentrations (0, 0.1, 0.5 and 5 mg · L(-1)). The results indicate that TAP stimulated the activities of superoxide dismutase (SOD) and peroxidase (POD) in the roots of C. indica. The highest TAP concentrations significantly inhibited photosynthetic activities, as shown by a reduced effective quantum yield of PS II (ΦPS II) and lower electron transport rates (ETR). However, interestingly, the lower TAP loadings exhibited some favorable effects on these two variables, suggesting that C. indica is a suitable species for use in wetlands designed for treatment of low TAP concentrations. Urease and alkaline phosphatase (ALP) in the wetland substrate were activated by TAP. Two-way ANOVA demonstrated that urease activity was influenced by both the TAP concentrations and season, while acidphosphatase (ACP) only responded to seasonal variations. Analysis of high throughput sequencing of 16S rRNA revealed seasonal variations in the microbial community structure of the wetland substrate at the phylum and family levels. In addition, urease activity had a greater correlation with the relative abundance of some functional microbial groups, such as the Bacillaceae family, and the ALP and ACP may be influenced by the plant more than substrate microbial communities.

Enhancing the water purification efficiency of a floating treatment wetland using a biofilm carrier.

Floating treatment wetlands (FTWs) and biofilm carriers are widely used in water purification. The objective of the present work was to explore whether and to what extent an FTW integrated with plants and biofilm carriers (FTW-I) could enhance the nutrient removal efficiency. Significantly higher removal rates of ammonia nitrogen (85.2 %), total phosphorus (82.7 %), and orthophosphate (82.5 %) were observed in the FTW-I treatment relative to the FTW with plants (FTW-P; 80.0, 78.5, and 77.6 %, respectively) and the FTW with biofilm carriers (FTW-B; 56.7, 12.9, and 13.4 %, respectively) (p < 0.05). The mass balance results indicated that plant uptake was the main pathway for N and P removal (accounting for 58.1 and 91.4 %, respectively) in FTW-I, in which only 1.2 % of the N and 5.7 % of the P was deposited on the bottom of the tank. In addition, the plants translocated 43.9 and 80.2 % of the N and P in the water and 83.5 and 88.3 % of the absorbed N and P, respectively, into their aboveground tissues. The combination of an FTW and biofilm carriers can improve the efficiency of water purification, and nutrients can be rapidly removed from the system by harvesting the aboveground plant tissues.

Acclimation of Hydrilla verticillata to sediment anoxia in vegetation restoration in eutrophic waters.

Sediment anoxia generally results from intense organic enrichment and is a limiting factor in the restoration of vegetation in eutrophic waters. To investigate the effect of sediment anoxia on a typical pollution-tolerant submerged macrophyte species, Hydrilla verticillata, and acclimation mechanisms in the plant, a gradient of sediment anoxia was simulated with additions of sucrose to the sediment, which can stimulate increased concentrations of total nitrogen, NH4(+) and Fe in pore water. H. verticillata growth was significantly affected by highly anoxic conditions, as indicated by reduced total biomass in the 0.5 and 1% sucrose treatments. However, slight anoxia (0.1% sucrose addition) promoted growth, and the shoot biomass was 22.64% higher than in the control. In addition to morphologic alterations, H. verticillata showed physiological acclimations to anoxia, including increased anaerobic respiration and changes in carbon and nitrogen metabolism in roots. The soluble protein and soluble carbohydrate contents in roots of the 1% treatment were both significantly higher compared with those in the control. The increase in alcohol dehydrogenase activity and pyruvate content in the roots suggested that H. verticillata has a well-developed capacity for anaerobic fermentation. This study suggests that highly anoxic sediments inhibit the growth of H. verticillata and the species has a degree of tolerance to anoxic conditions. Further in situ investigations should be conducted on the interactions between sediment conditions and macrophytes to comprehensively evaluate the roles of sediment in the restoration of vegetation in eutrophic waters.

Performance evaluation of wastewater treatment using horizontal subsurface flow constructed wetlands optimized by micro-aeration and substrate selection.

The effects of micro-aeration and substrate selection on domestic sewage treatment performance were explored using three pairs (with or without micro-aeration) of horizontal subsurface flow (HSSF) constructed wetlands (CWs) filled with zeolite, ceramsite or quartz granules. The individual and combined effects of micro-aeration and substrate selection on the purification performance of the experimental-scale HSSF CWs were evaluated. The results showed that micro-aeration significantly increased the treatment efficiencies for chemical oxygen demand, total nitrogen, total phosphorus (TP), ortho-phosphate (PO4(3-)-P) and ammonium nitrogen (NH4+-N) using HSSF CWs, while the substrate selection significantly affected the TP, PO4(3-)-P and NH4+-N removal efficiencies (p<0.05). A two-way analysis of variance (ANOVA) indicated that there was a significant interaction term (i.e. micro-aeration×substrate selection) for NH4+-N removal (p<0.05). Among the three substrates, ceramsite was the best substrate for the treatment of domestic sewage using HSSF CWs. Therefore, the results of this study suggest that a ceramsite-filled HSSF CW with micro-aeration could be the optimal configuration for decentralized domestic sewage treatment.

Submerged macrophyte Ceratophyllum demersum affects phosphorus exchange at the sediment-water interface.

Substantial research efforts were made to assess the effects of submerged macrophytes on water quality improvement, but information on the mechanism of submerged macrophytes relative to the exchange of phosphorus (P) at the sediment-water interface is very limited. To help fill the void, a popular species, Ceratophyllum demersum L. was chosen to address the effects and mechanisms of submerged macrophyte growth on the processes of P exchange across the sediment--water interface. In treatment mesocosms (planted), equilibrium phosphorus concentration (EPC0) value falls from 68.4 to 36.0 µg/L, with a mean value of 52.5 µg/L. Conversely, the distribution coefficient (Kd) value has a predominantly increasing trend. But they are both significantly higher than an unplanted control (p < 0.05). Also, in the planted mesocosm, maximum phosphate sorption capacity (Qmax) was significantly reduced (4,721-3,845 mg/kg), and most of the linear correlations between different forms of phosphorus and sediment P adsorption parameters were affected (p < 0.05). The EPC0 Percentage Saturation percentages (EPCsat) in planted groups were 325% higher than that in control (p < 0.05). We conclude that C. demersum could promote the release of P from sediments, and soluble reactive phosphorus concentration in overlying water is probably the driving force for P exchange at the sediment-water interface.

Bacterial community analysis by PCR-DGGE and 454-pyrosequencing of horizontal subsurface flow constructed wetlands with front aeration.

Horizontal subsurface flow constructed wetlands (HSSF CWs) with and without redox manipulation by front aeration were operated to treat mechanically pretreated wastewater from a nearby wastewater treatment plant. Polymerase chain reaction-denaturing gradient gel electrophoresis and 454-pyrosequencing were used to characterize the shifts in bacterial community diversity and composition in response to front aeration in the HSSF CWs. Both techniques revealed similar bacterial diversity between the HSSF CWs with (ACW) and without front aeration (NACW). Differences in microbial functional groups between the ACW and the NACW substrate samples were identified with 454-pyrosequencing. Nitrite-oxidizing bacteria (Nitrospira) and ammonia-oxidizing bacteria (Nitrosomonas) had much higher abundances in the ACW, whereas more sequences related to sulfate-reducing bacteria and anaerobic sulfur-oxidizing bacteria (genera Sulfuricella, Sulfuritalea, and Sulfuricurvum) were detected in the NACW. Removal efficiencies for NH4(+)-N, PO4(3-)-P and chemical oxygen demand in the ACW were 48.7 ± 15.5, 70.2 ± 13.5, and 82.0 ± 6.4%, respectively, whereas the removal efficiencies for these parameters in the NACW were 10.3 ± 14.0, 53.1 ± 18.9, and 68.8 ± 10.7%, respectively. In the ACW, the stimulation of nitrification via front aeration supplied more NO2(-)-N and NO3(-)-N to the subsequent denitrification process than in the NACW, resulting in higher total inorganic nitrogen removal efficiency. The differences in treatment efficiencies between the ACW and the NACW could be partially explained by the different bacterial community compositions in the two CWs.

[Sacral neuromodulation in the treatment of intractable constipation].

OBJECTIVE: To assess the efficacy of sacral neuromodulation (SNM) in patients with intractable constipation. METHODS: A total of 7 patients with intractable constipation were treated with pereutaneous test stimulation of the S3 nerve root and were assessed by sacral never stimulation system in our department from January 2013 to January 2014. Four of these 7 patients received operation for constipation before. The efficacy was assessed by bowel habit diary, clinic constipation scores, subjective questionnaire and clinical signs. RESULTS: The constipation symptoms were improved significantly in all the 7 patients. The frequency and volume of defecation per week were increased obviously, and the average urine was increased. Six patients underwent permanent implantation of the SNS system. After a median 4 months follow-up, the defecation frequency increased from 0.6 ± 0.5 to 8.0 ± 2.5 per week (P<0.01), and the defecation time decreased from (22.9 ± 11.5) to (3.7 ± 0.8) min (P<0.01). The Cleveland clinic constipation score decreased from 24.6 ± 4.2 to 9.0 ± 0.9 (P<0.01), and the visual analogue scale(VAS) score increased from 8.1 ± 0.9 to 82.5 ± 5.2 (P<0.01). CONCLUSION: SNM is a clinically efficacious, minimally invasive and safe new technique, which offers an alternative treatment for the patients with intractable constipation resistant to conservative treatment, especially for the patients refractory to traditional operations.