Optimizing the connection of CRRT and ECMO lines with additional pressure regulator on the therapeutic effect, filter life, and incidence of complications.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is used for severe cardiopulmonary failure, with veno-arterial ECMO for cardiogenic shock and veno-venous ECMO for acute respiratory failure. ECMO's application has expanded to ICUs, emergency departments, and operating rooms. ECMO patients are at high risk for complications, including acute kidney injury (AKI), often requiring renal replacement therapy (RRT), posing significant management challenges. METHODS: From August 2015 to June 2022, 120 patients were cured with veno-venous ECMO (n = 60) or veno-arterial ECMO (VA-ECMO, n = 60) combined with CRRT in our hospital. In the control group (n = 60), the input end (arterial end) of CRRT was connected to the ECMO oxygenator. The reinfusion end (venous end) of CRRT was connected to the oxygenator of ECMO for CRRT + ECMO treatment. In the experimental group (n = 60), the input end (arterial end) of CRRT was connected to the oxygenator of ECMO, and an additional pressure regulating device was installed on the connection of the 2 lines. The observation indexes including clinical therapeutic effect, clinical therapeutic effect, the incidence of complications, and the incidence of complications were compared. RESULTS: There was a notable decrease in serum creatinine, and the differences in blood urea nitrogen, procalcitonin, and C-reactive protein after operation were statistically significant (P < .05). The filter use time in the study group was notably longer (P < .01). There exhibited no remarkable difference in the incidences of bleeding, thrombosis, numbness of hands and feet, metabolic alkalosis, disseminated intravascular coagulation, organ dysfunction syndrome, hyperbilirubinemia, and infection. CONCLUSION: This study demonstrates that additional pressure regulation devices are installed at the line connection between the CRRT input end and the CRRT return end to ensure that the flow rate of ECMO does not affect the CRRT treatment. ECMO and CRRT provide a safe pressure range so that the ECMO line can be safely connected to the CRRT machine at physiological pressure, reducing the occurrence of complications related to CRRT machine interruption and improving the efficiency of CRRT without affecting the efficiency of ECMO, ensuring patient safety.

The knowledge, attitude and behavior of ICU nurses regarding ICU-acquired weakness: a cross-sectional survey.

BACKGROUND: Intensive care unit-acquired weakness (ICU-AW) is very common in ICU patients. It is important to understand the status quo of knowledge, attitude and behavior of ICU nurses about ICU-AW. This survey aimed to investigate the knowledge, attitude and behavior of ICU nurses about ICU-AW, to provide useful implications for clinical care. METHODS: ICU nurses from two tertiary hospitals in China from October 10 to November 15, 2023 were included. The ICU-AW knowledge, attitude and behavior questionnaire of ICU nurses with 31 items were used for survey. SPSS24.0 statistical software was used for data analysis. RESULTS: A total of 364 ICU nurses were included for survey. The ICU-AW knowledge of ICU nurses was 21.96 ± 5.72 (< 50% of the total knowledge score), the ICU-AW attitude of ICU nurses was 30.24 ± 5.05(< 75% of the total attitude score), the ICU-AW behavior of ICU nurses was 26.77 ± 5.81(< 75% of the total behavior score), the total score was 79.21 ± 12.69(< 75% of the total score). Nurses' ICU-AW knowledge, attitude and behavior were all correlated (all P < 0.05). Multiple linear regression analyses indicated that age, years of ICU work experience, professional ranks and titles, had received the training about the ICU-AW were the influencing factors of knowledge, attitude and behavior of ICU nurses about ICU-AW (all P < 0.05). CONCLUSIONS: The knowledge, attitude and behavior of ICU nurses' ICU-AW needs to be improved, and there are many influencing factors. Hospital nursing administrators should strengthen the training of nurses' ICU-AW knowledge and improve the cognitive and practical ability of ICU nurses on ICU-AW, so as to reduce the occurrence of ICU-AW.

The correlation between early net fluid balance and the clinical outcomes of patients receiving extracorporeal cardiopulmonary resuscitation.

OBJECTIVE: To investigate correlation between early net fluid balance and the clinical outcomes of patients receiving extracorporeal cardiopulmonary resuscitation (ECPR). METHODS: Adult patients on ECPR admitted to the Department of Emergency in the First Affiliated Hospital of Nanjing Medical University from May 2015 to December 2020 were included. Net fluid balance for consecutive 4 days after ECPR was recorded. The primary outcome was survival to intensive care unit (ICU) discharge. We used multivariable logistic regression to assess the association between fluid status and clinical outcomes. RESULTS: A total of 72 patients were enrolled and divided into two groups: the survivor group and the non-survivor group. The overall rate of survival to ICU discharge was 44.4%. Daily fluid balance (DFB) in the survivor group was lower than that in the non-survivor group at day 4 (-11.47 (-19.74, 8.7) vs. -5.08 (-12.94, 13.9) mL/kg, P=0.046), as was cumulative fluid balance (CFB) over the first 4 days (-36.03 (-51.45, 19.03) vs. -7.22 (-32.79, 21.02) mL/kg, P=0.009). Both continuous renal replacement therapy (CRRT) and CFB from days 1-4 were significantly correlated with survival to ICU discharge (OR=14.617, 95% CI: 1.344, 48.847, P=0.028; OR=1.261, 95% CI: 1.091, 1.375, P=0.003, respectively). CFB from days 1-4 was determined to have a roughly linear association with the log odds of survival to ICU discharge. CONCLUSION: Early negative fluid balance maybe associated with survival to ICU discharge in patients receiving ECPR.

Impact of connecting methods of continuous renal replacement therapy device on patients underwent extracorporeal membrane oxygenation: A retrospectively observational study.

OBJECTIVE: The objective of this study was to compare the safety and efficiency of different extracorporeal membrane oxygenation (ECMO) and continuous renal replacement therapy (CRRT) connection methods. BACKGROUND: The number of patients receiving ECMO is increasing, and the fields of application are getting wider. However, patients receiving ECMO are prone to acute kidney injury and fluid overload requiring CRRT. There are few comparative studies of two different systems of connecting CRRT device and ECMO from safety and efficacy perspective. METHODS: This retrospective observational study included patients receiving ECMO in the extracorporeal life support centre of the First Affiliated Hospital of Nanjing Medical University from June, 2015, to December, 2020. Patients were divided into the parallel system group and integrated system group according to the connecting method between ECMO circuit and CRRT line. The outcomes were discharge survival rate, CRRT therapeutic dose completion rate, CRRT catheterisation time, CRRT initiating time, local bleeding at the CRRT catheter site, mean filter life, ECMO circuit thrombosis, ECMO air leakage, or blood leakage due to CRRT. RESULTS: Thirty patients in the parallel system group and 70 patients in the integrated system group were finally included. The discharge survival rate and CRRT therapeutic dose completion rate were not significantly different between the two groups. The parallel system group had significant longer CRRT initiating time (49.0 ± 12.1 min vs. 14.6 ± 2.1 min, P < 0.001) and shorter filter life (11.5 ± 3.2 h vs. 47.3 ± 14.0 h, P < 0.001) than the integrated system group. The occurrence rate of local bleeding was 93.3% in the parallel system group, and there is no bleeding case in the integrated system group. There was no case of ECMO circuit thrombosis from CRRT as well as ECMO air or blood leakage caused by CRRT in either group. ECMO therapy can be adapted by adjusting the position of the CRRT outlet in the integrated system. CONCLUSIONS: Connecting CRRT and ECMO as an integrated system might accelerate CRRT initiation, avoid local bleeding, and prolong filter life compared to the parallel system. The chance of developing CRRT-related ECMO circuit leak and thrombosis is manageable.

Clinical observation of different targeted temperature management methods in patients with cardiac arrest.

OBJECTIVE: To explore the clinical value of extracorporeal cardiopulmonary resuscitation (ECPR) combined with different targeted temperature management (TTM) for the treatment of cardiac arrest. METHODS: From January 2018 to September 2020, ECPR was initiated in patients with cardiac arrest who did not have their spontaneous circulation restored after 20 minutes of traditional cardiopulmonary resuscitation (CPR). A total of 22 patients (observation group) given TTM were treated with Hico-variotherm 550 (HU 550) and 30 patients (control group) not given TTM were treated with a medical water circulation cooling blanket. The Glasgow Coma scale (GCS) score, serum neuron-specific enolase (NSE), survival rate and neurological prognosis after ECMO weaning were compared between the two groups. RESULTS: There was no significant difference between the two groups in GCS score on the third and seventh days after resuscitation and serum NSE on the first and third day after treatment (P>0.05). Compared with the control group, the survival rate (40.91% vs 33.33%) and favorable neurological outcome (36.36% vs 26.67%) of patients in the observation group were slightly higher, but the differences were not statistically significant (all P>0.05). The incidence of shivering and body temperature fluctuation during rewarming in the observation group was lower than that in the control group (P<0.05). CONCLUSION: HU550 poikilothermia water cabinet combined with ECMO can better control the targeted temperature of patients in a more accurate range and improve the survival rate; however, it exerts no statistical improvement in the incidence of complications.

FT-like paralogs are repressed by an SVP protein during the floral transition in Phalaenopsis orchid.

KEY MESSAGE: An SVP protein, PhSVP, bound to the CArG-boxes in the promoter regions of FT-like paralogs and repressed their expression, thus affecting the floral transition in Phalaenopsis orchid. Phalaenopsis is an important ornamental flower native to tropical rain forests. It usually reaches vegetative maturity after 4-5 leaves and, after a juvenile stage, forms a flower spike (inflorescence) from the axillary buds. The PEBP gene family encodes a phosphatidyl-ethanolamine-binding protein (PEBP) domain involved in regulating flowering and other aspects of plant development. Here, we identified eight PEBP family genes in Phalaenopsis and detected the expression patterns of seven of them in various organs. Among them, PhFT1 (Phalaenopsis hybrid FLOWERING LOCUS T1), PhFT3, PhFT5, and PhMFT (Phalaenopsis hybrid MOTHER OF FT AND TFL1) promoted flowering in transgenic Arabidopsis, while PhFT6 inhibited flowering. PhSVP (Phalaenopsis hybrid SHORT VEGETATIVE PHASE), an SVP protein that repressed flowering in Arabidopsis, bound to the CArG-boxes in the promoter regions of PhFT3, PhFT6, and PhMFT in a yeast one-hybrid assay. Additionally, dual-luciferase and transient expression assays showed that PhSVP significantly inhibits the expression of both PhFT3 and PhFT6. Together, our work provides a comprehensive understanding of the PhFT-like genes that can promote or repress flowering, and it suggests strategies for regulating the floral transition in Phalaenopsis that exploit the evolutionary versatility of PhFTs to respond to various signals stimuli.

Can Cardiopulmonary Rehabilitation Facilitate Weaning of Extracorporeal Membrane Oxygenation (CaRe-ECMO)? Study Protocol for a Prospective Multidisciplinary Randomized Controlled Trial.

Background: Mortality of patients suffering from critical illness has been dramatically improved with advanced technological development of extracorporeal membrane oxygenation (ECMO) therapy. However, the majority of ECMO-supported patients failed to wean from ECMO therapy. As one of several options, cardiopulmonary rehabilitation serves as effective intervention in the improvement of cardiovascular and respiratory function in various major critical illness. Nonetheless, its role in facilitating ECMO weaning has not yet been explored. The purpose of this study is to investigate the effectiveness of cardiopulmonary rehabilitation on rate of ready for ECMO weaning in ECMO-supported patients (CaRe-ECMO). Methods: The CaRe-ECMO trial is a randomized controlled, parallel group, clinical trial. This trial will be performed in a minimum number of 366 ECMO-supported eligible patients. Patients will be randomly assigned to either: (1) the CaRe-ECMO group, which will be treated with usual care including pharmacotherapy, non-pharmacotherapy, and specific nursing for ECMO therapy and the CaRe-ECMO program; or (2) the control group, which will receive usual care only. The CaRe-ECMO program consists of protocolized positioning, passive range of motion (PROM) training, neuromuscular electrical stimulation (NMES), surface electrical phrenic nerve stimulation (SEPNS), and pulmonary rehabilitation. The primary outcome of the CaRe-ECMO trial is the rate of ready for ECMO weaning at CaRe-ECMO day 7 (refers to 7 days after the CaRe-ECMO program initiation). Secondary outcomes include rate of ECMO and mechanical ventilation weaning, total length in day of ready for ECMO weaning, ECMO weaning and mechanical ventilation, all-cause mortality, rate of major post-ECMO complications, ECMO unit length of stay (LOS) and hospital LOS, total cost for hospitalization, cerebral performance category (CPC), activities of daily living (ADL), and health-related quality of life (HRQoL). Discussion: The CaRe-ECMO is designed to answer the question "whether cardiopulmonary rehabilitation can facilitate weaning of ECMO (CaRe-ECMO)." Should the implementation of the CaRe-ECMO program result in superior primary and secondary outcomes as compared to the controls, specifically the add-on effects of cardiopulmonary rehabilitation to the routine ECMO practice for facilitating successful weaning, the CaRe-ECMO trial will offer an innovative treatment option for ECMO-supported patients and meaningfully impact on the standard care in ECMO therapy. Clinical Trial Registration: ClinicalTrials.gov, identifier: NCT05035797.

Spatial and temporal distribution characteristics of different forms of inorganic nitrogen in three types of rivers around Lake Taihu, China.

In order to control nitrogen (N) pollution of Lake Taihu, China, we studied the spatial and temporal distribution characteristics of inorganic N in inflowing rivers polluted by industry, agriculture, and domestic sewage during low, moderate, and high flow periods. The results showed that dissolved total nitrogen (DTN) was the main fraction of total nitrogen (TN) input from these rivers. Inflowing rivers had distinct impacts on TN, DTN, ammonium N (NH4+), and nitrate N (NO3-) concentrations of Lake Taihu during the low flow period. Particulate nitrogen (PN) had an impact on Lake Taihu during the three flow periods and all the three types of rivers would increase PN concentration in the lake. Rivers polluted by agriculture had the greatest impact on Lake Taihu's TN, DTN, NO3-, and dissolved inorganic N (DIN) concentrations, while rivers polluted by industry had the greatest impact on NH4+ concentration. Therefore, agriculture and industry should be key targets for nutrient reductions. The in-lake N concentrations were higher than those of inflowing rivers during moderate and high flow periods.

[Predictive values of different critical scoring systems for survival rate after discharge in critically ill patients supported by extracorporeal membrane oxygenation].

OBJECTIVE: To determine the predictive values of different critical scoring systems for survival rate after discharge in critically ill patients supported by extracorporeal membrane oxygenation (ECMO). METHODS: The clinical data of 34 critically ill patients supported by ECMO admitted to Department of Emergency of the First Affiliated Hospital of Nanjing Medical University (Jiangsu Provincial People's Hospital) from July 2015 to September 2017 were retrospectively analyzed. The general information and the worst values of vital signs and related pathophysiological indicators within 12 hours before ECMO treatment of patients were collected, and sequential organ failure assessment (SOFA), multiple organs dysfunction score (MODS), simplified acute physiology score II (SAPS II), and acute physiology and chronic health evaluation IV (APACHE IV) scores were calculated. The patients were divided into survival group and non-survival group according to 28-day survival after hospital discharge. General clinical characteristics and aforementioned scores were compared between the two groups. Scoring systems for predicting prognosis were assessed by using the receiver operating characteristic (ROC) curve. The Kaplan-Meier method was used to depict the surviving curve. RESULTS: Thirty-four patients were finally enrolled, 13 of whom were dead at the follow-up period of 28 days after hospital discharge, and 21 survived. Duration of ECMO support in non-survival group was significantly shorter than that in survival group (hours: 101.4±7.8 vs. 134.4±12.6), SOFA, SAPS II, and APACHE IV scores were significantly higher than those of survival group (SOFA score: 10.6±3.6 vs. 8.8±3.3, SAPS II score: 38.7±14.3 vs. 31.8±12.5, APACHE IV score: 46.5±15.5 vs. 38.1±11.3, all P < 0.05). There was no significant difference in gender, age, body mass index (BMI), vital signs or related pathophysiological indicators within 12 hours before ECMO treatment, or MODS score between the two groups. ROC curve analysis showed that the area under ROC curve (AUC) of SAPS II score for predicting 28-day survival rate was the highest, which was significantly higher than that of SOFA, MODS, and APACHE IV score (0.880 vs. 0.694, 0.654, 0.682, all P < 0.05). When the best cut-off value of SAPS II score was 43, the sensitivity was 81.2%, and the specificity was 77.9%. Kaplan-Meier survival analysis showed that 28-day survival rate after hospital discharge in patients with SAPS II score < 43 (n = 18) was significantly higher than that in patients with SAPS II score ≥ 43 (n = 16; χ2 = 2.444, P = 0.018). CONCLUSIONS: Four critical scoring systems of SOFA, MODS, SAPS II and APACHE IV have been proved to have good prognostic ability to predict 28-day survival after hospital discharge in critically ill patients supported by ECMO. Among them, SAPS II score system has more accurate prediction value.

Video versus direct laryngoscopy on successful first-pass endotracheal intubation in ICU patients.

BACKGROUND: Airway management in intensive care unit (ICU) patients is challenging. The aim of this study was to compare the rate of successful first-pass intubation in the ICU by using the direct laryngoscopy (DL) and that by using the video laryngoscopy (VL). METHODS: A randomized, non-blinded trial comparing first-pass success rate of intubation between VL and DL was performed. Patients were recruited in the period from August 2014 to August 2016. All physicians working at ICU received hands-on training in the use of the video and direct laryngoscope. The primary outcome measure was the first-pass intubation success. RESULTS: A total of 163 ICU patients underwent intubation during the study period (81 patients in VL group and 82 in DL group). The rate of successful first-pass intubation was not significantly different between the VL and the DL group (67.9% vs. 69.5%, P=0.824). Moreover, the overall intubation success and total number of attempts to achieve intubation success did not differ between the two groups. In patients with successful first-pass intubation, the median duration of the intubation procedure did not differ between the two groups. The Cormack-Lehane grades and the percentage of glottic opening score were similar, and no significant differences were found between the two groups. There were no statistical differences between the VL and the DL group in intubation complications (all P>0.05). CONCLUSION: Among ICU patients requiring intubation, there was no significant difference in the rate of successful first-pass intubation between VL and DL.

Expression profiles of five FT-like genes and functional analysis of PhFT-1 in a Phalaenopsis hybrid

Background: Phalaenopsis is an important ornamental flowering plant that belongs to the Orchidaceae family and is cultivated worldwide. Phalaenopsis has a long juvenile phase; therefore, it is important to understand the genetic elements regulating the transition from vegetative phase to reproductive phase. In this study, FLOWERING LOCUS T (FT) homologs in Phalaenopsis were cloned, and their effects on flowering were analyzed. Results: A total of five FT-like genes were identified in Phalaenopsis. Phylogenetic and expression analyses of these five FT-like genes indicated that some of these genes might participate in the regulation of flowering. A novel FT-like gene, PhFT-1, distantly related to previously reported FT genes in Arabidopsis and other dicot crops, was also found to be a positive regulator of flowering as heterologous expression of PhFT-1 in Arabidopsis causes an early flowering phenotype. Conclusions: Five FT homologous genes from Phalaenopsis orchid were identified, and PhFT-1 positively regulates flowering.

Effects of epiphytic algae on biomass and physiology of Myriophyllum spicatum L. with the increase of nitrogen and phosphorus availability in the water body.

The disappearance of submerged vascular macrophytes in shallow eutrophic lakes is a common phenomenon in the world. To explore the mechanism of the decline in submerged macrophyte abundance due to the growth of epiphytic algae along a nutrient gradient in eutrophic water, a 2 × 3 factorial experiment was performed over 4 weeks with the submerged macrophyte (Myriophyllum spicatum L.) by determining the plant's biomass and some physiological indexes, such as chlorophyll (Chl) content, malondialdehyde (MDA) content, and superoxide dismutase (SOD) activity in the leaves of M. spicatum L. on days 7, 14, 21, and 28, which are based on three groups of nitrogen and phosphorus levels in the water body (N-P [mg L-1]: NP1 0.5-0.05, NP2 2.5-0.25, NP3 4.5-0.45) and two levels of epiphytic algae (the epiphytic algae group and the control group). Epiphytic algal biomass was also assayed. The results indicated that epiphytic algal biomass remarkably enhanced in the course of the experiment with elevated levels of nitrogen and phosphorus in the water. Under the same level of nutrient condition, plants' biomass accumulation and Chl content were higher in the control group than that in the epiphytic algae group, respectively, while MDA content and SOD activity in the former were lower than that in the latter. The influences of epiphytic algae on the biomass accumulation and Chl content and MDA content became greater and greater with elevated levels of nutrients. In general, in this experiment, water nutrients promoted the growth of both epiphytic algae and submerged plants, while the growth of epiphytic algae hindered submerged macrophytes' growth by reducing Chl content and promoting peroxidation of membrane lipids in plants.

[Spatial and Temporal Distribution Characteristics of Different Forms of Phosphorus in Three Sorts of Rivers around Lake Taihu].

Different forms of phosphorus from the upper reaches of river to lower reaches of river in nine rivers were analyzed to clarify the pollution characteristics of industrial effluent, agriculture effluent and sanitary wastewater to Lake Taihu in February (low water period), May (average water period) and August (abundant water period) of 2009. The results showed that total phosphorus (TP) dissolved total phosphorus (DTP) and soluble reactive phosphorus ( SRP) mass concentration all showed decreasing trend while enzymatic phosphorus (EHP) mass concentration increased with the increase of algal biomass from low water period to abundant water period. Mass concentrations of several forms of phosphorus were all the highest in the rivers impacted by sanitary wastewater, but sanitary wastewater's self-purification capabity from the upper reaches of river to lower reaches of river was the best, and the pollution to Lake Taihu was the lowest. Pollution from rivers impacted by industrial effluent was the highest. Mass concentration of EHP was higher than that of SRP in most cases, so EHP played an important role in Cyanbacterial harmful algal blooms events in Lake Taihu.

The physiological responses of Vallisneria natans to epiphytic algae with the increase of N and P concentrations in water bodies.

To reveal the mechanism of submerged plants decline in progressively eutrophicated freshwaters, physiological responses of Vallisneria natans to epiphytic algae were studied in simulation lab by measuring plant physiological indexes of chlorophyll content, malondialdehyde (MDA) content, and superoxide dismutase (SOD) activity based on a 2 × 4 factorial design with two epiphytic conditions (with epiphytic algae and without) and four levels of N and P concentrations in water (N-P[mg.L(-1)]: 0.5, 0.05; 2.5, 0.25; 4.5, 0.45; 12.5, 1.25). Compared with control (non-presence of epiphytic algae), chlorophyll contents of V. natans were significantly decreased (p < 0.01) for the presence of epiphytic algae under any concentrations of N and P in water bodies. While the presence of epiphytic algae induced peroxidation of membrane lipids, MDA contents of V. natans had significantly increased (p < 0.05) by comparing with control. SOD activity significantly enhanced (p < 0.05) with the presence of epiphytic algae in the treatments of T2 and T3 in the whole culture process by comparing with control, sometimes reaching an extremely significant level (p < 0.01). However, in the treatments of T1 and T4, SOD activity had no obvious change with the presence of epiphytic algae (p < 0.05) by comparing with control. At the end of the experiment, the effects of epiphytic algae on chlorophyll content and SOD activity in the leaves of V. natans were increased at first and then decreased with the concentrations of N and P in water, and MDA content became higher with the increase of N and P. concentrations. Repeated measurement data testing showed that the effects of epiphytic algae on the chlorophyll content and MDA content and SOD activity were significant, respectively (p < 0.001), the effects of epiphytic algae were combining with effects of concentrations of N and P (p < 0.001), respectively, and their interaction (p < 0.001). Our observations confirmed that this prediction: the growth of epiphytic algae directly produced adverse effects on physiology of V. natans and epiphytic algal biomass were positively correlated with nutrient available in the water column.

Influence of UV radiation on chlorophyll, and antioxidant enzymes of wetland plants in different types of constructed wetland.

A surface- and vertical subsurface-flow-constructed wetland were designed to study the response of chlorophyll and antioxidant enzymes to elevated UV radiation in three types of wetland plants (Canna indica, Phragmites austrail, and Typha augustifolia). Results showed that (1) chlorophyll content of C. indica, P. austrail, and T. augustifolia in the constructed wetland was significantly lower where UV radiation was increased by 10 and 20 % above ambient solar level than in treatment with ambient solar UV radiation (p < 0.05). (2) The malondialdehyde (MDA) content, guaiacol peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) activities of wetland plants increased with elevated UV radiation intensity. (3) The increased rate of MDA, SOD, POD, and CAT activities of C. indica, P. australis, and T. angustifolia by elevated UV radiation of 10 % was higher in vertical subsurface-flow-constructed wetland than in surface-flow-constructed wetland. The sensitivity of MDA, SOD, POD, and CAT activities of C. indica, P. austrail, and T. augustifolia to the elevated UV radiation was lower in surface-flow-constructed wetland than in the vertical subsurface-flow-constructed wetland, which was related to a reduction in UV radiation intensity through the dissolved organic carbon and suspended matter in the water. C. indica had the highest SOD and POD activities, which implied it is more sensitive to enhanced UV radiation. Therefore, different wetland plants had different antioxidant enzymes by elevated UV radiation, which were more sensitive in vertical subsurface-flow-constructed wetland than in surface-flow-constructed wetland.

[Variation of water quality and trophic state of Lake Tianmu, China].

Water quality survey was carried out in 2006 and 2007 in Lake Tianmu (Shahe Reservoir) of China in order to make clear the eutrophication reasons of urban lake-type reservoirs in the middle and lower reaches of Yangtze River, and then put forward the corresponding control measures for such reservoirs. The survey frequency was once a month in 2006 and once two months from May 2007 to Dec. 2007. The results indicate that total nitrogen (TN) and total phosphorus (TP) average concentrations were 1.49 mg/L and 0.06 mg/L respectively in 2006, which are 2.7 and 2 times those of 2001-2002. The average permanganate index was 3.68 mg/L in 2006 and it is a little higher than that of 2001-2002. Secchi disk depth (SD) was 1.2 m in 2006 and it is 25 cm lower than that of 2001-2002. The average algal biomass of 2006 was 46.39 mg/L. All of these show that Lake Tianmu has been situated meso-eutrophication in 2006 from the meso to meso-eutrophication in 2001-2002. Control measures of Lake Tianmu were put forward according to the joint survey results of water quality, sediments, fishery, plankton, benthos etc. in 2006, which considered exogenous, endogenesis and substance cycle of the lake ecosystem in together. The measures pointed out that it was needed to control the pollution of agriculture, river, tourism, soil and water erosion as well as fishery etc. in order to increase SD of the reservoirs. TN and TP average concentrations in 2007 were 1.25 mg/L and 0.05 mg/L respectively, and the average algal biomass of 2007 was 22.56 mg/L. Water quality variation between 2006 and 2007 showed that the control measures had effect on reducing nutrients contents and phytoplankton biomass of the lake.

[Release of colloidal N and P from sediment of lake caused by continuing hydrodynamic disturbance].

The course of continuing hydrodynamic disturbance and succeeding long time settlement of lake water was simulated to study the release of nitrogen (N) and phosphorus (P) from lake sediment. It was showed in the experiment that the hydrodynamic disturbance caused abundant release of particulate and colloidal phosphorus and nitrogen. The concentration of total nitrogen (TN) and total phosphorus (TP) in water reached the highest values of 2.106 mg/L and 0.272 mg/L, respectively, when the water was disturbed for 0.5 d, and the concentration of colloidal nitrogen (CN) and colloidal phosphorus (CP) in water reached the highest values of 0.452 mg/L and 0.052 mg/L, respectively, when the water was disturbed for 1 day. Then, the concentration of TN, TP, CN and CP turned to decrease despite the continuing disturbance, for the particles and colloid deposited exceeded that suspended. During the settling phase after disturbance, the bigger suspended particles deposited quickly while the tiny colloid deposited much slower, and the concentration of CN and CP did not decrease until the water was settled for 1 day. The concentration of ultra-filtrated dissolved nitrogen (UDN) and ultra-filtrated dissolved phosphorus (UDP) increased much more in the settling phase than in the disturbing phase. It can be drawn that the adsorption of colloid limited the increase of dissolved N and P in lake water in the disturbing phase and prolonged the time of suspended N and P stayed in water. And the N and P adsorbed by colloid could also be released into water in the settling phase after disturbance, which delayed the elimination of nutrition and improvement of water quality.