Microvascular Rarefaction and Myocardial Fibrosis in Hypertrophic Obstructive Cardiomyopathy: A Histopathological Comparison of Pediatric and Adult Patients.

BACKGROUND: Hypertrophic obstructive cardiomyopathy (HOCM) is a genetic cardiomyopathy characterized by microvascular ischemia and myocardial fibrosis. Microvessels play an important role in myocardial fibrosis in HOCM. However, the changes of myocardial microvessels and myocardial fibrosis in pediatric and adult patients with HOCM remain unclear. This study was to investigate the changes in myocardial microvessel density (MVD) and myocardial fibrosis in pediatric and adult patients with HOCM. METHODS: We analyzed the changes in MVD and myocardial fibrosis in myectomy left ventricular (LV) septal wall specimens in 12 adult patients and five pediatric patients with HOCM. Control myocardium from the LV septal wall was collected at autopsy of 5 adults and 4 pediatric individuals, who died of non-cardiac causes. RESULTS: There was no significant difference in MVD between pediatric HOCM patients and control subjects (706.4±187.5 vs. 940.2±491.1, P > 0.05), but the myocardial fibrosis area ratio was significantly increased in HOCM than in control subjects (10.6±3.5 vs. 4.9±1.2, P < 0.01). MVD was significantly reduced, and myocardial fibrosis area ratio was significantly higher in adult HOCM patients than in control subjects (i.e. 523.3± 209.4 vs. 845.7±260.7, P < 0.05; 12.8±5.1 vs. 4.4±1.3, P < 0.05). There was no significant difference in MVD and myocardial fibrosis between pediatric and adult HOCM patients (706.4±187.5 vs. 523.3±209.4, P > 0.05; 10.6±3.5 vs. 12.8±5.1, P > 0.05).  Conclusions: Pediatric and adult patients with HOCM have high myocardial fibrosis. The present findings suggest that myocardial microvascular density lesions contribute to myocardial fibrosis during childhood.

Coronary artery bypass grafting in patients with malignancy: a single-institute case series of eight patients.

BACKGROUND: The surgical strategy among patients with malignancy and coronary artery disease (CAD) remains controversial. In this study, we present the experiences of coronary artery bypass grafting (CABG) in patients with malignancy and analyzed the treatment outcomes. METHODS: From January 2011 to October 2021, eight patients combined with coronary artery disease and malignancy, six of them with three-vessel disease and two with anterior descending branch lesions on coronary angiography. The age ranged from 54 to 73 years (61.8 ± 7.7years). Four patients underwent CABG and staging for surgical oncology, and 2 patients underwent CABG and surgical oncology simultaneously. Four patients underwent CABG procedure with cardiopulmonary bypass (on-pump CABG), and the other patients underwent the procedure without cardiopulmonary bypass (off-pump CABG). All patients were followed up for 3 to 96 months (40.4 ± 31.5 months) postoperatively. RESULTS: The mean number of grafts was 2.6 ± 1.1, there was no in-hospital death, postoperative myocardial infarction, and stroke. Among the eight patients, one patient received chemotherapy and radiation before bypass surgery, which occurred postoperatively pulmonary infection, and the rest of 7 patients had no major adverse cardiovascular events during follow-up periods. CONCLUSION: Based on the results of the present study, simultaneous or staged CABG and oncologic surgery according to the TNM stage of the tumor and cardiac assessment is an effective treatment for patients with severe CAD combined with malignancy.

Comparative efficacy and safety of PD-1/PD-L1 Inhibitors versus platinum-based chemotherapy for the first-line treatment of advanced non-small cell lung cancer: a meta analysis of randomized controlled trials.

OBJECTIVE: The main aim of this study was to systematically evaluate the efficacy and safety of inhibitors of programmed cell death receptor 1 (PD-1) and its ligand, programmed cell death ligand-1 (PD-L1), in the treatment of advanced non-small cell lung cancer (NSCLC). METHODS: Randomized controlled trials assessing the efficacy of PD-1/PD-L1 inhibitors relative to platinum-based chemotherapy for advanced NSCLC in PubMed, EMBASE, and Cochrane libraries from 2015 to 2020 were searched, along with review of studies at American Society of Clinical Oncology (ASCO) and European society for Medical Oncology (ESMO). Pooled hazard ratios (HR) for progression-free survival (PFS) and overall survival (OS) and odds ratios (OR) for adverse events (AE) were calculated using STATA and Revman software. RESULTS: PD-1/PD-L1 inhibitors alone or combined with chemotherapy significantly improved OS (HR = 0.82, 95% CI:0.74-0.91, P = 0.01 or HR = 0.74, 95% CI:0.67-0.82, P = 0.001). PD-1/PD-L1 inhibitors alone did not benefit PFS (HR = 0.99, 95% CI: 0.89-1.10, P = 0.892), while combination therapy led to prolonged PFS (HR = 0.61, 95% CI: 0.56-0.67, P < 0.001). Subgroup analysis showed that in NSCLC with PD-L1 ≥ 50%, treatment with PD-1/PD-L1 inhibitors alone significantly improved both PFS and OS. In patients subjected to the combined treatment regimen, we observed significant differences in PFS among groups stratified by PD-L1 expression (p < 0.001), immune drug type (p = 0.029), gender (p = 0.014) and liver metastasis (p = 0.035) and OS among groups stratified by immune drug type (p < 0.001), gender (P = 0.001) and smoking status (P = 0.041). Safety analysis showed that combination therapy increased chemotherapy-induced adverse events (AE), while PD-1/PD-L1 inhibitors alone were associated with a lower incidence of any grade of treatment-related AEs (TRAE). A higher incidence of Grade 3-5 TRAEs and hypothyroidism was observed with PD-1 inhibitors than PD-L1 inhibitors. CONCLUSIONS: First-line treatment of advanced NSCLC with immune monotherapy or immunochemotherapy confers a greater survival benefit than chemotherapy alone. Combination of chemotherapy with PD-1/PD-L1 inhibitors leads to an increase in adverse events, and PD-1 inhibitors offer enhanced survival benefits and fewer adverse events than PD-L1 inhibitors. Remarkably, female patients undergoing combination therapy had longer overall survival than male patients.

Surgical intervention of myocardial bridge combined coronary artery disease: could a combination of supra-arterial myotomy and CABG be a better option?

BACKGROUND: The treatment of coronary artery disease combined with severe atherosclerotic stenosis proximal to a left anterior descending artery myocardial bridge (LAD-MB) is still controversial. This study aimed to analyze the outcomes of surgical intervention in patients with severe atherosclerotic stenosis proximal to a LAD-MB. METHODS: We retrospectively reviewed all patients with coronary artery disease combined with severe atherosclerotic stenosis proximal to the LAD-MB. The enrolled criteria were systolic compression of LAD more than or equal to 50% and atherosclerotic stenosis proximal to the LAD-MB more than or equal to 70%. All patients suffered from anginal symptoms refractory to medical therapy. All patients received supra-arterial myotomy and coronary artery bypass grafting (CABG) procedures. Clinical characteristics, intraoperative findings, and postoperative outcomes were evaluated. RESULTS: Between 2004 and 2021, sixteen patients underwent supra-arterial myotomy and CABG procedure. The compression and length of LAD-MB were 63 ± 17.9% and 25.9 ± 16.3 mm, respectively. Of the 16 patients, one patient had a LAD-MB and proximal coronary stenosis, and 15 patients had LAD-MBs and multivessel lesions. All patients survived and recovered uneventfully without in-hospital mortality or severe complications. The median transfusion amount of red blood cells in the operation was 2 units, and no patients required unplanned reoperation for bleeding. The average length of intensive care unit stay was 2.74 days. Fifteen patients were followed up for 6-146.1 months (mean 45.3 ± 42.9 months). One patient had a recurrence of angina pectoris one year after surgery, and 14 patients had no symptoms of myocardial ischemia during the follow-up period. Significant improvement in symptoms and quality of life using the Seattle Angina Questionnaire assessment was observed in all five categories after surgery (p < 0.01). CONCLUSIONS: Based on the results, supra-arterial myotomy and concomitant bypass surgery may be a better option for the treatment of LAD-MB combined with severe proximal stenosis.

Left ventricle reverse remodeling in chronic aortic regurgitation patients with dilated ventricle after aortic valve replacement.

BACKGROUND: Aortic valve replacement (AVR) for chronic aortic regurgitation (AR) with a severe dilated left ventricle and dysfunction leads to left ventricle remodeling. But there are rarely reports on the left ventricle reverse remodeling (LVRR) after AVR. This study aimed to investigate the LVRR and outcomes in chronic AR patients with severe dilated left ventricle and dysfunction after AVR. METHODS: We retrospectively analyzed the clinical datum of chronic aortic regurgitation patients who underwent isolated AVR. The LVRR was defined as an increase in left ventricular ejection fraction (LVEF) at least 10 points or a follow-up LVEF ≥ 50%, and a decrease in the indexed left ventricular end-diastolic diameter of at least 10%, or an indexed left ventricular end-diastolic diameter ≤ 33 mm/m2. The changes in echocardiographic parameters after AVR, survival analysis, the predictors of major adverse cardiac events (MACE), the association between LVRR and MACE were analyzed. RESULTS: Sixty-nine patients with severe dilated left ventricle and dysfunction underwent isolated AVR. LV remodeling in 54 patients and no LV remodeling in 15 patients at 6-12 months follow-up. The preoperative left ventricular dimensions and volumes were larger, and the EF was lower in the LV no remodeling group than those in the LV remodeling group (all p < 0.05). The adverse LVRR was the predictor for MACE at follow-up. The mean follow-up period was 47.29 months (range 6 to 173 months). The rate of freedom from MACE was 94.44% at 5 years and 92.59% at 10 years in the remodeling group, 60% at 5 years, and 46.67% at 10 years in the no remodeling group. CONCLUSIONS: The left ventricle remodeling after AVR was the important predictor for MACE. LV no remodeling may not be associated with benefits from AVR for chronic aortic regurgitation patients with severe dilated LV and dysfunction.

Significant loss of soil inorganic carbon at the continental scale.

Widespread soil acidification due to atmospheric acid deposition and agricultural fertilization may greatly accelerate soil carbonate dissolution and CO2 release. However, to date, few studies have addressed these processes. Here, we use meta-analysis and nationwide-survey datasets to investigate changes in soil inorganic carbon (SIC) stocks in China. We observe an overall decrease in SIC stocks in topsoil (0-30 cm) (11.33 g C m-2 yr-1) from the 1980s to the 2010s. Total SIC stocks have decreased by ∼8.99 ± 2.24% (1.37 ± 0.37 Pg C). The average SIC losses across China (0.046 Pg C yr-1) and in cropland (0.016 Pg C yr-1) account for ∼17.6%-24.0% of the terrestrial C sink and 57.1% of the soil organic carbon sink in cropland, respectively. Nitrogen deposition and climate change have profound influences on SIC cycling. We estimate that ∼19.12%-19.47% of SIC stocks will be further lost by 2100. The consumption of SIC may offset a large portion of global efforts aimed at ecosystem carbon sequestration, which emphasizes the importance of achieving a better understanding of the indirect coupling mechanisms of nitrogen and carbon cycling and of effective countermeasures to minimize SIC loss.

[Clinical study of anticoagulation with warfarin and heparin in patients after mechanical valve replacement].

OBJECTIVE: To investigate the effect of different methods of anticoagulation after mechanical valve replacement. METHODS: Totally 172 cases of mechanical valve replacement performed from October 2005 to June 2008 were divided into two groups and then analyzed retrospectively. Patients on warfarin and heparin were classified as the heparin group while those on warfarin alone were classified as the warfarin group. The operation, anticoagulation, anticoagulation index and associated complications were recorded to compare the effect of anticoagulation between two groups. RESULTS: warfarin group: the overall anticoagulation effect was satisfactory except for cerebral embolism (n=1, 1.1%) and lower gastrointestinal hemorrhage (n=1, 1.1%) during hospitalization. Heparin group: no anticoagulation-related complication was found. The time to reach stable warfarin anticoagulation was shorter than the warfarin group and difference was of significance (8 d±3 d vs 11 d±4 d, P<0.01). After adjustment of potential confounding factors such as age, gender, weight by linear regression analysis, the result showed that, the time to reach stable warfarin anticoagulation was shortened than the warfarin group by 2.11 days. Statistical significance of difference was observed between two groups (P<0.01). CONCLUSION: It is both safe and effective to anticoagulated the patients after mechanical valve replacement with warfarin and heparin.

[One-stage repair of congenital aortic arch disease with other cardiac defects by using autologous pulmonary artery tissue].

OBJECTIVE: To analyze the surgical strategy and result of one-stage repair for congenital aortic arch disease associated with other cardiac anomalies. METHODS: Between April 1993 and November 2009, 25 consecutive patients aged 26 d to 6.5 years underwent one-stage repair for congenital aortic arch disease with other cardiac anomalies. Among them, 6 patients had coarctation of aorta, 6 patients had interrupted aortic arch, and 13 cases had hypoplasia of aortic arch. The surgical techniques include excision of the anterior wall of pulmonary artery, resection of patent ductus arteriosus tissue, aortic arch reconstruction with autologous pulmonary artery wall, reconstruction of the pulmonary artery and repair of the associated defects. RESULTS: Twenty-four patients survived and recovered uneventfully. One patient died of pulmonary hypertension crisis in hospital. The reconstruction of the aorta and the correction of the intracardiac anomalies were proved by postoperative echocardiography and CT scan. There were no neurological or other complications. The follow-up showed that all patients developed normally and there were no restenosis of the aorta arch. CONCLUSIONS: With the benefits of growth potential and less tension, autologous pulmonary artery tissue is an optimal choice in aortic arch reconstruction. One-stage repair of congenital aortic arch disease associated with other cardiac anomalies can achieve good results.

[Response of Aggregate Distribution to Input Straw and Their Linkages to Organic Carbon Mineralization in Soils Developed from Five Different Parent Materials].

Development and the dynamics of stable aggregates in many soils are known to be closely related to the cycling as well as accumulation of soil organic carbon (SOC). This study explored the aggregation processes and distributions of soil organic carbon in soils developed from limestone (L), quaternary red earth (Q), granite (G), basalt (B), and tertiary red sandstone (T) subtropical China related to the addition of maize residues during 7 days and 184 days of incubation. The soils were sieved to<0.25 mm before incubation. We aimed to clarify the mechanisms underlying SOC mineralization across soils from the perspective of soil aggregate protection. Fractionation of the water stable aggregates showed that addition of maize straw promoted the formation of>2 mm and 2-1 mm aggregates, while only 1.0-0.5, 0.5-0.25 and <0.25 mm aggregates were detected in the absence maize straw. The proportion of macroaggregates as well as their stability was always higher in L, Q, and B developed soils than those in G and T developed soils. In amended soils, the accumulation of total SOC was much obvious in L, Q, and B developed soils than those in G and T developed soils, and these increases were mainly contributed by the >0.25 mm macroaggregate-associated SOC. This result indicated that>0.25 mm macroaggregates were important spots for SOC sequestration. Furthermore, the proportions of>0.25 mm macroaggregate-associated SOC were also significantly (P<0.05) higher in L, Q, and B developed soils than those in G and T developed soils, and the free light organic carbon (fLOC) followed an inverse parent material pattern as>0.25 mm macroaggregate-associated SOC. Results also demonstrated that ratios of accumulative mineralized CO2-C to total soil organic carbon in L, Q, and B soils were significantly (P<0.05) lower than those in G and T soils. The correlation analysis further suggested that ratios of cumulative respired CO2-C to total soil organic carbon were significantly and positively correlated (P<0.01) with the proportion of fLOC, but inversely correlated (P<0.01) with the proportion of>0.25 mm macroaggregate-associated SOC. By applying 13C-NMR to characterize the inherent chemical composition of soil organic carbon fractions, we noted that fLOC was more deeply decomposed than intra-aggregate light organic carbon (intra-aggregate LOC), and both the fractions were advanced decomposed in G and T developed soils, verifying enhanced protection of added maize residues inside soil aggregates. The findings of the research suggested that the parent material exerts a significant influence on SOC mineralization by controlling the formation of aggregates and location of SOC in the hierarchical structure of the soil aggregate system. We demonstrated that enhanced physical protection of SOC by forming more stable macroaggregates contributes to carbon accumulation in limestone, quaternary red earth, and basalt developed soils treated with organic amendments.

[Staged total cavopulmonary connection for complex congenital heart diseases].

OBJECTIVE: To review the experience of staged total cavopulmonary connection (TCPC) in complex congenital heart diseases. METHODS: From June 1998 to March 2008, 22 patients underwent staged TCPC for complex congenital heart diseases. Among them, 9 were univentricular and pulmonary artery valve stenosis; 3 were univentricular and pulmonary artery atresia; 1 was transposition of great arteries, crisscross heart and pulmonary artery valve stenosis; 1 was complete atrioventricular canal defects, left ventricular hypoplasia, pulmonary artery atresia and atrioventricular valvular regurgitation; 1 was complete atrioventricular canal defects, left ventricular hypoplasia, pulmonary artery valve stenosis and atrioventricular valvular regurgitation after Glenn procedure; 1 was mirror image dextrocardia, single ventricle, pulmonary artery atresia, major aortopulmonary collateral arteries (MAPCAs) and right pulmonary arteriovenous fistula after Glenn procedure; 4 were tricuspid atresia and pulmonary artery valve stenosis; 1 was tricuspid atresia and pulmonary atresia; 1 was mirror image dextrocardia, double-outlet of right ventricle, left ventricular hypoplasia, pulmonary artery valve stenosis, tricuspid incompetence, and MAPCAs. Among them, 5 patients received systemic-to-pulmonary artery shunt, bidirectional Glenn procedure and TCPC. Seventeen patients received bidirectional Glenn procedure, the mean age was (5.9+/-4.4) years old. Pulmonary artery pressure pre-Glenn procedure was 17 to 20 mm Hg (1 mm Hg=0.133 kPa). Atrioventricular valve incompetence in 3 patients. Nakata index was less than 200 mm2/m2 in 4 patients before the first stage operation. The age of TCPC procedure was (9.6+/-4.9) years old, the interval time was (3.7+/-1.2) years. RESULTS: There was one in-hospital death, the mortality was 4.5%. The patient with univentricular and pulmonary atresia, received systemic-to-pulmonary artery shunt, bidirectional Glenn procedure and TCPC and died of pneumorrhagia. Other patients were recovered well, postoperative central venous pressure was 12 to 18 mm Hg, percutaneous oxygen saturation was 90% to 96%. The cardiac function were in NYHA class I to II. CONCLUSIONS: The staged TCPC was a good procedure in high-risk Fontan candidates. The results were satisfactory for those patients. This staged strategy may extend the operative indications for the Fontan procedure.

[Coronary artery bypass grafting in patients over 70 years old].

OBJECTIVE: To retrospectively analyze the experiences, indications, technique, and results of coronary artery bypass grafting (CABG) in patients over 70 years old. METHODS: Ninety-one patients received coronary artery bypass grafting from March 2004 to March 2008. Ages ranged from 70 to 83 years old, 22 patients over 75 years old. Conventional CABG (CCABG) in 72 patients, off-pump CABG (OPCAB) in 19 patients. Clinical data has no significant differences in two groups. The rate of using left internal mammary artery was 96.7%. The number of grafts in CCABG and OPCAB group were 2 to 5 (3.5 +/- 0.8) and 1 to 4 (2.9 +/- 0.7) respectively. RESULTS: In-hospital death in 2 cases, both were from chronic obstructive pulmonary disease and pulmonary infection. Cerebral infarction in 1 case and pulmonary infection in 2 cases in CCABG group, but no significant difference between two groups, and no difference in intubation, ICU stay, respiratory failure, renal function failure. But number of grafts in CCABG was significantly more than that in OPCAB (P < 0.01). Postoperative follow-up was 3 to 36 months, 1 case with recurrent angina in OPCAB. CONCLUSIONS: According to the characteristic of coronary artery disease in elderly, fully revascularization and improving myocardial blood supply, patients over 70 years old with CABG can obtain the same efficacy as younger patients. There were not significant difference between CCABG and OPCAB.

Spatial and temporal variation of nitrogen exported by runoff from sandy agricultural soils.

The eutrophication problem has drawn attention to nutrient leaching from agricultural soils, and an understanding of spatial and temporal variability is needed to develop decision-making tools. Thus, eleven sites were selected to monitor, over a two-year period, spatial and temporal variation of runoff discharge and various forms of N in surface runoff in sandy agricultural soils. Factors influencing the variation of runoff discharge and various forms of N in surface runoff were analyzed. Variation of annual rainfall was small among 11 sites, especially between 2001 and 2002. However, variation of annual discharge was significant among the sites. The results suggest that rainfall patterns and land use had significant effect on discharge. The concentrations of total N, total kjeldahl N (TKN), organic matter-associated N (OM-N), NO3(-)-N, and NH4(+)-N in the runoff ranged widely from 0.25 to 54.1, 0.15 to 20.3, 0.00 to 14.6, 0.00 to 45.3, and 0.00 to 19.7 mg/L, respectively. Spatial and temporal variations in the N concentration and runoff discharge were noted among the different sites. Annual loads of N in the runoff varied widely among monitoring sites and depend mainly on runoff discharge. High loads of total N, OM-N, NO3(-)-N, and NH4(+)-N in the runoff either in citrus groves or on vegetable farms occurred from June to October for each year, which coincided with the rainy season in the region. This study found that N in surface runoff was related to rainfall intensity, soil N level, and fertilizer use.

[Surgical treatment of complex congenital heart diseases with extracardiac conduit total cavopulmonary connection].

OBJECTIVE: To report the experience of extracardiac conduit total cavopulmonary connection (ECTCPC) in surgical treatment of complex congenital heart diseases. METHODS: From 1998 to 2006, 68 patients underwent ECTCPC for complex congenital heart diseases. Among them, 45 had functional univentricle with transposition of the great artery (TGA) and pulmonary artery valve stenosis, 19 had tricuspid atresia with hypoplasia of right ventricle, 4 had Ebstein's anomaly with hypoplasia of right ventricle. Six had left superior vena cava, 18 had received Bidirectional Glenn operation; Fifty-seven cases were performed under cardiopulmonary bypass with general anesthesia and hypothermia, 11 cases were performed without cardiopulmonary bypass. RESULTS: There were two death, the mortality was 2.9%. All patients were followed up from 1 to 8 years with no clinical symptoms and have been doing well. The arterial oxygen saturation was 90% - 96%, the cardiac function were in NYHA class I - II. CONCLUSION: The extra cardiac conduit TCPC is a simple procedure and superior to other type of Fontan procedure in most patients.

Surgical Treatment of Double Outlet Right Ventricle Complicated by Pulmonary Hypertension.

BACKGROUND: Double outlet right ventricle (DORV) is a group of complex congenital heart abnormalities. Preoperative pulmonary hypertension (PH) is considered an important risk factor for early death during the surgical treatment of DORV. The aim of this study was to report our experience on surgical treatment of DORV complicated by PH. METHODS: From June 2004 to November 2016, 61 patients (36 males and 25 females) aged 2 weeks to 26 years (median: 0.67 years and interquartile range: 0.42-1.67 years) with DORV (two great arteries overriding at least 50%) complicated by PH underwent surgical treatment in our center. All patients were categorized according to surgical age and lesion type, respectively. Pulmonary artery systolic pressure (PASP), pulmonary artery diastolic pressure (PADP), and mean pulmonary artery pressure (mPAP) were measured directly before cardiopulmonary bypass (CPB) was established and after CPB was removed. An intracardiac channel procedure was performed in 37 patients, arterial switch procedure in 19 patients, Rastelli procedure in three patient, Senning procedure in one patients, and Mustard procedure in one patient. The Student's t-test and Chi-squared test were performed to evaluate clinical outcomes of the surgical timing and operation choice. RESULTS: Fifty-five patients had uneventful recovery. PASP fell from 55.3 ± 11.2 mmHg to 34.7 ± 11.6 mmHg (t = 14.05, P < 0.001), PADP fell from 29.7 ± 12.5 mmHg to 18.6 ± 7.9 mmHg (t = 7.39, P < 0.001), and mPAP fell from 40.3 ± 10.6 mmHg to 25.7 ± 8.3 mmHg (t = 11.85, P < 0.001). Six (9.8%) patients died owing to complications including low cardiac output syndrome in two patients, respiratory failure in two, pulmonary hemorrhage in one, and sudden death in one patient. Pulmonary artery pressure (PAP) dropped significantly in infant and child patients. Mortality of both infants (13.9%) and adults (33.3%) was high. CONCLUSIONS: PAP of patients with DORV complicated by PH can be expected to fall significantly after surgery. An arterial switch procedure can achieve excellent results in patients with transposition of the great arteries type. Higher incidence of complications may occur in patients with ventricular septal defect (VSD) type before 1 year of age. For those with remote VSD type, VSD enlargement and right ventricle outflow tract reconstruction are usually required with acceptable results. The degree of aortic overriding does not influence surgical outcome.

Phosphorus accumulation and eutrophication in feed-supply freshwater fishponds.

The rapid growth and intensification of freshwater fishery can cause imbalances between phosphorus (P) input in feed and its output in produce. This aquaculture can result in enriching exogenous P in fishponds and, consequently, accelerates the process of eutrophication. To assess relations among input, accumulation, release of P and as a consequence degrading water quality in terms of chlorophyll-a (Chl-a) in freshwater fishponds, fourteen fishponds with feed supply, nine fishponds without feed supply, and five non-fish ponds in Shaoxing Plain, southeast China were selected for comparing P accumulation in their waters and surface sediments. Surface sediment samples were collected from each pond to evaluate their total P, water soluble P, Olsen P, algal available P, and P fractions. Water samples were also collected from the ponds to measure concentrations of dissolved P and Chl-a. Total P in the sediments ranged from 0.88 to 1.73 g/kg in the fishponds with feed supply, that in the non-fish ponds ranged from 0.47 to 0.86 g/kg. Organic P, accounted for 23% to 60% of total P in the sediments, was an important P fraction and increased linearly with increasing organic matter. Long-term application of feeds resulted in increased P availability in the bottom sediments and degradation of water quality in the freshwater fishponds. Compared with non-fish ponds, sediments from the feed-supplied fishponds contained considerably higher Olsen P, algal available P, and water soluble P. Higher proportions of the labile P (NH4Cl-P) and potentially labile P (NaOH-IP) were also found in the sediments from the fishponds. High solubility of P in the sediments resulted in elevation of P and chlorophyll-a concentration in the pond water. The dissolved P concentration in the pond water increased in the order of non-fish ponds (12 microg/L) < fishponds without feed supply (24 microg/L) < fishponds with feed supply (66 microg/L). Linear correlations between concentrations of total P, Olsen-P, algal available P, water-soluble P and P concentration in saturation extracts in the sediments and dissolved P in the pond water indicated that there was a buffering action of the sediment constituents on the dissolved P.

[Comprehensive evaluation of improving effects of different organic wastes on a newly reclaimed cultivated land].

There are many problems such as low soil organic matter, available nutrients and microbial activity, compaction, and poor tillage properties for a newly reclaimed cultivated land, and the establishment of a fast, effective measure for improving soil fertility quality is of importance to enhance the quality and production performance of the newly cultivated land. A field experiment was carried out to observe the effect of organic wastes on soil fertility of a newly reclaimed cultivated land, and compared the differences of different types of urban organic wastes. The field experiment included nine treatments, i.e., pig manure, chicken manure, rice straw, vegetable harvest residue, urban sludge, biogas residue, manure+rice straw compost, garbage compost and control without organic fertilizer at annual application rate of 30 t . hm-2, and ran for three consecutive years. The results showed that the application of each type of the eight organic wastes had obvious effects on improving soil fertility. Among them, pig manure, chicken manure, pig manure+rice straw compost, rice straw and biogas residue were the most effective to enhance the carbon pool management index of soil. The addition of pig manure+rice straw compost and biogas residue had the best effect on increasing the soil water stable aggregates and decreasing soil bulk density. Sewage sludge, pig manure+rice straw compost and garbage compost could enhance soil water holding capacity. Pig manure, chicken manure and pig manure+rice straw compost had most obvious effect on increasing soil available nutrients. All kinds of organic wastes increased the number of soil microorganisms and the activity of enzymes. There were some risk of soil heavy metals pollution.for the long-term application of sludge, garbage compost and manure. However, the impact of short-term application of the wastes on soil environmental quality was not obvious. Overall, effects of organic wastes on soil fertility decreased in the order of pig manure+rice straw compost>chicken manure>pig manure>biogas residue >garbage compost>rice straw>urban sludge>vegetable harvest residue, and the effects on soil pollution increased in the sequence of rice straw

Release behavior of copper and zinc from sandy soils.

The concentrations and chemical forms of copper (Cu) and zinc (Zn) in surface soils directly influence the movement of Cu and Zn. In this study, thirteen sandy soil samples with a wide range of total Cu and Zn concentrations were collected for evaluating the relationships between Cu and Zn release and extraction time, ratio of soil to water, pH and electrolyte types. The results indicated that Cu released in batch extraction that represents long-term leaching was mainly from exchangeable, and carbonate bound Cu fractions, and Zn released in the batch extraction was mainly from its carbonate bound fraction. However, the Cu and Zn leached from the soils using the column leaching that represents short-term leaching were mainly from their exchangeable fractions. Soil column leaching at different pH values indicated that the amounts of leached Zn and Cu were greatly affected by pH. The Cu and Zn release experiments with varying extraction times and ratio of soil to water suggest that long-term water-logging in the soils after rain may increase contact time of the soils with water and the release of Cu and Zn to water from the soils, and total amounts of Cu or Zn released from the soils increase, but the Cu or Zn concentration in the surface runoff decrease with increasing rainfall intensity. The increased Ca concentration in soil solution increased stability of organic matter-mineral complexes and might decrease the dissolution of organic matter, and thus decreased the release of Cu-binding component of organic matter. However, high concentration of Na in the soil solution increased the dispersion of the organic matter-mineral complexes and increased dissolution of organic matter and the release of Cu from the soils.

[Effects of irrigation of untreated livestock farm wastewater on accumulation and vertical mig- ration of nitrogen and phosphorus in paddy soil].

Although a series of process techniques for treating wastewater from livestock and poultry breeding have been developed in China and overseas, it is still common in China's rural areas for utilization of the untreated wastewater to irrigate farmland directly because of economic reasons. The impact of untreated wastewater irrigation on accumulation and vertical migration of nitrogen and phosphorus in paddy soil is concerned. Consequently, four representative paddy fields with different histories of livestock farm wastewater irrigation (0, 4, 7, 13 years) were selected for collecting profile soil samples to study the effects of long-term irrigation of untreated livestock farm wastewater on various forms of nitrogen and phosphorus in the soils at different vertical depths. As compared with control field without any irrigation of wastewater, long-term irrigation of untreated livestock farm wastewater significantly increased the accumulation of N and P in the soils with increasing the irrigation year, and the increment of total P in the soil was greater than that of total N. Total P content in surface soil from fields with 4, 7, and 13 years irrigation was increased by 43.6%, 95.2%, and 148.4%, while total N increased by 7.6%, 16.9%, and 28.4%, respectively. Different forms of soil N were increased in order of NH4+ -N, NO3- -N > acid hydrolyzable N > non-acid hydrolyzable N, and soil available P changed much more than total P. Long-term irrigation of untreated livestock farm wastewater could promote vertical migration of soil nitrogen and phosphorus, and increase the pollution risk for groundwater.

A comparison of physiologically based extraction test (PBET) and single-extraction methods for release of Cu, Zn, and Pb from mildly acidic and alkali soils.

In vitro digestion test can be applied to evaluate the bioaccessibility of soil metals by measuring the solubility of the metals in synthetic human digestive tract. Physiologically based extraction test (PBET), composed of sequential digestion of gastric and intestinal phase, is one of the frequently used in vitro digestion tests. In this study, the PBET was chosen to determine the bioaccessibility of Cu, Zn, and Pb in 14 mildly acidic and alkali (pH 5.87-8.30) soils. The phytoavailability of Cu, Zn, and Pb in the same soils was also measured using six single-extraction methods (0.1 M HNO3, 0.4 M HOAc, 0.1 M NaNO3, 0.01 M CaCl2, 0.05 M EDTA, and 0.5 M DTPA). The extraction efficiencies of the methods were compared. The PBET had a strong ability to extract metals from soil, which was much greater than neutral salt extraction and close to dilute acid and complex extraction in spite of the last 2 h neutral intestinal digestion. The amounts of bioaccessible Cu, Zn, and Pb in the gastric phase and in the gastrointestinal phase were both largely determined by the total content of soil Cu, Zn, and Pb. But the results of gastrointestinal digestion reflected more differences resulting from element and soil types than those of gastric digestion did. It was noticed that most of variations in the amounts of soil Cu, Zn, and Pb extracted by EDTA were well explained by the total soil Cu, Zn, and Pb, as same as the PBET. Moreover, the solubility of Cu, Zn, and Pb in the gastric phase and gastrointestinal phase were all positively linearly correlated with the results of EDTA. It was suggested that EDTA extraction can be used to predict the bioaccessibility of Cu, Zn, and Pb in mildly acidic and alkali (pH > 5.8) soils, and the PBET and EDTA could be applied to measure, in a certain extent, the bioaccessibility and phytoavailability of Cu, Zn, and Pb in mildly acidic and alkali (pH > 5.8) soils at the same time.

The function of digestive enzymes on Cu, Zn, and Pb release from soil in in vitro digestion tests.

The bioaccessibility of soil heavy metals is the solubility of soil heavy metals in synthetic human digestive juice, which is usually determined using in vitro digestion test. To reveal the effects of digestive enzymes on soil heavy metals bioaccessibility, three representative in vitro digestion tests, Simple Bioaccessibility Extraction Test (SBET), Physiologically Based Extraction Test (PBET), and Simple Gastrointestinal Extraction Test (SGET), were chosen. The bioaccessibility of soil Cu, Zn, and Pb in each method were respectively evaluated with and without digestive enzymes, and the differences were compared. The results showed that the effects of digestive enzymes varied with different methods and elements. Because of digestive enzymes addition, the environmental change from acid gastric phase to neutral intestinal phase of PBET did not result in apparently decrease of the bioaccessibility of soil Cu. However, the solubility of soil Zn and Pb were pH-dependent. For SGET, when digestive enzymes were added, its results reflected more variations resulting from soil and element types. The impacts of digestive enzymes on heavy metal dissolution are mostly seen in the intestinal phase. Therefore, digestive enzyme addition is indispensable to the gastrointestinal digestion methods (PBET and SGET), while the pepsin addition is not important for the methods only comprised of gastric digestion (SBET).