Release of cadmium in contaminated paddy soil amended with NPK fertilizer and lime under water management.

Agricultural soils contaminated with cadmium (Cd) pose a risk to receiving surface water via drainage or runoff. A 90-day laboratory incubation experiment was conducted to investigate the release characteristics and transformation of Cd from contaminated paddy soil amended with agrochemical (NPK fertilizer) and lime (L) under water management regimes of continuous flooding (F) and drying-wetting cycles (DW). The result showed that the dissolved Cd concentrations in overlying water of the fertilizer treatment under flooding (NPK+F) and drying-wetting (NPK+DW) reached up to 81.0 µg/L and 276 µg/L, and were much higher than that from the corresponding controls without NPK fertilizer addition at the end of experiment. The Cd concentration showed significantly negative correlation with overlying water pH, but positive correlation with soil redox potential and concentrations of dissolved total nitrogen, sulfate and manganese in overlying water (P < 0.05), indicating that drying-wetting cycles and N fertilizer addition may enhance soil Cd release. The Cd concentrations in overlying water from all treatments except NPK+L+F treatment exceeded the Cd threshold limit of Chinese Environmental Quality Standards for Surface Water (10 µg/L Grade V) and poses potential risk to surface water quality. Meanwhile, the proportion of Cd in the acid-soluble fraction from all incubated soil except NPK+L+F treatment increased compared to before incubation. The results indicated that continuous flooding was a reasonable water management candidate coupled with lime addition for immobilizing soil Cd.

Response of soil microbial activities and microbial community structure to vanadium stress.

High levels of vanadium (V) have long-term, hazardous impacts on soil ecosystems and biological processes. In the present study, the effects of V on soil enzymatic activities, basal respiration (BR), microbial biomass carbon (MBC), and the microbial community structure were investigated through 12-week greenhouse incubation experiments. The results showed that V content affected soil dehydrogenase activity (DHA), BR, and MBC, while urease activity (UA) was less sensitive to V stress. The average median effective concentration (EC50) thresholds of V were predicted using a log-logistic dose-response model, and they were 362mgV/kg soil for BR and 417mgV/kg soil for DHA. BR and DHA were more sensitive to V addition and could be used as biological indicators for soil V pollution. According to a polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis, the structural diversity of the microbial community decreased for soil V contents ranged between 254 and 1104mg/kg after 1 week of incubation. As the incubation time increased, the diversity of the soil microbial community structure increased for V contents ranged between 354 and 1104mg/kg, indicating that some new V-tolerant bacterial species might have replicated under these conditions.

[The Effect of Chronic Intermittent Hypoxia on Cognitive Function and Prefrontal Cortex Neurons in Rats].

OBJECTIVE: To determine the effect of chronic intermittent hypoxia on cognitive function and prefrontal cortex neurons in rats. METHODS: 48 adult male Wistar rats were randomly divided into two groups: control group and 50 mL/L intermittent hypoxia group (50 mL/L CIH). Rats in the CIH group were placed in the low oxygen tank, simulating intermittent hypoxia environment. At 7 d, 14 d, 21 d, and 28 d, the learning and memory ability of the rats was assessed with the Morris water maze (MWM) test; the expressions of cysteinyl aspartate specific protease (caspase)-8 protein in their prefrontal cortex were determined using Western blot method; the apoptosis of neurons was detected by the TdT mediated UTP nick end labeling (TUNEL) method. RESULTS: Compared with the controls, the CIH rats had significantly prolonged escape latency at 14 d, 21 d, and 28 d (P<0. 05) and decreased target quadrant time (P<0. 05). The prolonged escape latency increased and target quadrant time shortened with length of exposure to hypoxia (P<0. 05). Compared with controls, the CIH rats had gradually increased caspase-8 in their frontal cortex neurons, peaked at 28 d (P<0. 05). The CIH rats showed obvious structural damage and reduced neuron density in their frontal cortex neurons. They had higher levels of nerve cell apoptosis (P<0. 05), with apoptosis index increasing with length of exposure to hypoxia (P<0. 05). CONCLUSION: Severe chronic intermittent hypoxia can lead to pathological changes of frontal,cortex of rats, possibly

Dearomatizing [2+2+1] Spiroannulation of Indoles with Alkynes.

A palladium-catalyzed dearomatizing [2+2+1] spiroannulation of indoles with two molecular internal alkynes is developed in the presence of Cu(OAc)2/O2 as the oxidant, in which a domino sequence including C-H activation of indole followed by consecutive Heck reactions is involved. A range of 3,3'-spiroindolines bearing tetrasubstituted cyclopentadiene moieties and exocyclic C═C bonds at C2 are obtained in moderate to excellent yields.

Effect of two surgical approaches on the lung function and prognosis of patients with combined esophagogastric cancer.

BACKGROUND: Adenocarcinoma of the esophagogastric junction has a center of origin within 5 cm of the esophagogastric junction. Surgical resection remains the main treatment. A transthoracic approach is recommended for Siewert I adenocarcinoma of the esophagogastric junction and a transabdominal approach is recommended for Siewert III adenocarcinoma of the esophagogastric junction. However, there is a need to determine the optimal surgical approach for Siewert II adenocarcinoma of the esophagogastric junction to improve lung function and the prognosis of patients. AIM: To investigate and compare the surgical effects, postoperative changes in pulmonary function, and prognoses of two approaches to treating combined esophagogastric cancer. METHODS: One hundred and thirty-eight patients with combined esophagogastric cancer treated by general and thoracic surgeries in our hospital were selected. They were divided into group A comprising 70 patients (transabdominal approach) and group B comprising 68 patients (transthoracic approach) based on the surgical approach. The indexes related to surgical trauma, number of removed lymph nodes, indexes of lung function before and after surgery, survival rate, and survival duration of the two groups were compared 3 years after surgery. RESULTS: The duration of surgery, length of hospital stay, and postoperative drainage duration of the patients in group A were shorter than those of the patients in group B, and the volume of blood loss caused by surgery was lower for group A than for group B (P < 0.05). At the one-month postoperative review, the first second, maximum ventilation volume, forceful lung volume, and lung volume values were higher for group A than for group B (P < 0.05). Preoperatively, the QLQ-OES18 scale scores of the patients in group A were higher than those in group B on re-evaluation at 3 mo postoperatively (P < 0.05). The surgical complication rate of the patients in group A was 10.00%, which was lower than that of patients in group B, which was 23.53% (P < 0.05). CONCLUSION: Transabdominal and transthoracic surgical approaches are comparable in treating combined esophagogastric cancer; however, the former results in lesser surgical trauma, milder changes in pulmonary function, and fewer complications.

[The relation of learning deficits with oxidative stress in rats exposed to severe intermittent hypoxia].

OBJECTIVE: To observe the relations between learning memory function and oxidative stress in rats exposed to severe intermittent hypoxia (IH). METHODS: Adult male Wistar rats (n = 48) were randomly assigned to 2 groups: untreated control group (UC) and 5% intermittent hypoxia group (5%IH). At 2, 4, 6 and 8 weeks, the learning and memory ability of the rats in each group were assessed with the Morris water maze (MWM) test. The ultrastructural changes in the hippocampus of the rats were observed with transmission electron microscopy (TEM). The levels of malondialdehyde (MDA) and superoxide dismutase (SOD) were detected by colorimetric method. RESULTS: The water maze test showed that the rats in the 5% IH group had prolonged latency in escaping, reduced target quadrant time in crossing and reduced frequency of crossing the platform, as compared to the UC group (P < 0.05). With longer time of hypoxia, the damage became more significant. It was observed that the structure of neuron cell was complete and organelles were abundant in UC groups. With the extension of exposure time, the number of hippocampus neurons and synaptic were decreased in 5%IH groups, nucleus shrank, synaptic frame became indefinite and synaptic cleft widen. Comparing with control group, the level of MDA in the hippocampal region group was significantly higher (P < 0.05) and the activity of SOD significantly was lower (P < 0.05) in 5%IH, along with the time expand, which aggravated. CONCLUSION: Severe intermittent hypoxia that results in learning and memory dysfunction. It is possible that oxidative stress change the quantity and structure of hippocampal neurons and synaptic, which aggravates along with the intermittent low oxygen time expand.

LINC00511 promotes gastric cancer cell growth by acting as a ceRNA.

BACKGROUND: Gastric cancer (GC) is one of the most aggressive malignancies, with a high incidence and poor prognosis worldwide. Recently, accumulating evidence has illustrated that long noncoding RNAs (lncRNAs) play pivotal roles in many cancers. It has been reported that LINC00511 contributes to tumorigenesis in various diseases. However, the role of LINC00511 in GC cell growth remains mostly unknown. AIM: To determine whether the lncRNA LINC00511 exerted its carcinogenic function in GC via the miR-124-3p/PDK4 axis. METHODS: Cell culture and transfection, RNA extraction and quantitative real-time PCR, CCK-8 assay, Colony formation assay, Luciferase reporter assay, RIP assay, RNA pull-down assay, and Western blot analysis were used to show expression and mechanisms of LINC00511 in GC progression and apoptosis. Rescue assays were performed to verify the relationships among LINC00511, miR-124-3p and PDK4 further. RESULTS: The expression of LINC00511 was remarkably upregulated in GC cells compared to that in corresponding normal cell lines. Compared to the controls, cell proliferation was inhibited, and cell apoptosis was increased upon LINC00511 knockdown, demonstrating that LINC00511 influenced GC cell growth. An exploration of the molecular mechanism revealed that LINC00511 functioned as a molecular sponge of miR-124-3p and that PDK4 was a downstream target of miR-124-3p in GC. Rescue assays showed that the overexpression of PDK4 could partly restore the inhibitory function of si-LINC00511 in GC. CONCLUSION: These data demonstrate that LINC00511 promotes gastric cancer cell growth by acting as a ceRNA to regulate the miR-124-3p/PDK4 axis, which may be a promising therapeutic target for GC.

[Distribution and Accumulation of Cadmium in Paddy Soil and Rice Affected by Pollutant Sources Control and Improvement Measures].

The objective of this study was to determine the effect of five scenarios on the accumulation of Cd in the soil-rice system, including the return of straw to the field and the lack of the return, atmospheric deposition control, use of clean water for irrigation, and the use of lime. For the field experiments, three typical paddies were selected and divided into five plots (5 m×6 m) in Xiangtan, Zhuzhou, and Liling in the Hunan province from April to October 2016. The results showed that the application of lime can increase pH by 0.87, while the available Cd concentration in the soil was decreased by 33.7%. The accumulations of Cd in roots, stems, and brown rice were decreased by 47.9%, 46.7%, and 54.8%, respectively, with a decrease in the corresponding bioconcentration factors. Irrigating with clean water and liming tended to increase the soil pH by 0.44 and 0.49, respectively, while the available Cd concentration in the soil was decreased by 18.2% and 14.5%, respectively. The Cd concentrations in roots, stems, and brown rice were decreased by 32.6%, 24.2%, and 18.0%, and 17.6%, 11.3%, and 25.4% with decreased bioconcentration factors under both treatments (irrigating with clean water and liming). The available Cd concentration in the soil was increased by 6.1% and the Cd accumulation in the rice plants also increased with the return of straw to the soil. The bioconcentration factors of the rice plants were also increased when the paddy straw was returned to the fields. The results showed that the measures, such as the use of lime, atmospheric deposition control, use of clean water for irrigation, and lack of the return of straw to the paddy soil, should be helpful for the safe production of brown rice. The possible long-term risks associated with returning straw to the paddy field should be evaluated scientifically.

Expression of annexin A5 in serum and tumor tissue of patients with colon cancer and its clinical significance.

AIM: To investigate the expression of annexin A5 in serum and tumor tissue of patients with colon cancer and to analyze its clinical significance. METHODS: Ninety-three patients with colon cancer treated at our hospital between February 2013 and March 2016 were included in an observation group, and 40 healthy individuals were included in a control group. Enzyme-linked immunosorbent assay was performed to determine the serum level of annexin A5, while immunohistochemistry was performed to determine the expression of annexin A5 in cancer tissues. RESULTS: The serum level of annexin A5 was 0.184 ± 0.043 ng/mL in the observation group, which was significantly higher than that in the control group (P < 0.05). Annexin A5 expression was detected in 79.31% of the patients with lymph node metastasis, which was significantly higher than that in patients without lymph node metastasis (P < 0.05). Moreover, annexin A5 expression was detected in 86.96% of the patients with stage III to IV disease, which was significantly higher than that in patients with stage I to II disease (P < 0.05). The serum level of annexin A5 was 0.215 ± 0.044 ng/mL in patients whose tumors were positive for annexin A5 expression, which was significantly higher than that in patients whose tumors were negative for annexin A5 expression (P < 0.05). The serum level of annexin A5 was correlated with annexin A5 expression in colon cancer tissues (r = 0.312, P < 0.05). When a cutoff value of > 0.148 ng/mL for serum level of annexin A5 was used in the diagnosis of colon cancer, the sensitivity was 83.90%, and the specificity was 57.50%. CONCLUSION: For patients with colon cancer, annexin A5 expression in cancer tissues is related to lymph node metastasis and tumor grade. Serum level of annexin A5 is related to annexin A5 expression in cancer tissues and is of diagnostic relevance.

[Yearly Changes of Phytoplankton Community in the Ecology-monitoring Area of Changli, Hebei in Summer].

Based on the investigation of phytoplankton and water body nutrient concentration in the ecology-monitoring area of Changli in summer from 2005 to 2013, the phytoplankton community structure was analyzed. The result showed that in recent 9 years, 3 phyla including 23 families, 39 genera and 105 species of phytoplankton were identified, in which 85.7% were diatoms and 13.3% were dinoflagellate. Only one species was found belonging to golden algae. There was great difference in dominant species among different years. According to the value of dominance, there were Coscinodiscus radiatus, Coscinodiscus debilis, Rhizosolenia styliformis, Cerataulina bergoni, Coscinodiscus wailesii, Thalassiosira sp., Ceratium tripos, Chaetoceros lorenzianus, Skeletonema costatum. The cell abundance was decreased yearly. The Shannon-Wiener index of phytoplankton community ranged from 0.015 to 3.889, and the evenness index ranged from 0.009 to 1, which showed little yearly change. And phytoplankton species were unevenly distributed among the 19 sites, there were relatively low amount of dominant species, but the dominance was relatively high. Canonical Correspondence Analysis (CCA) results of the phytoplankton community and its environmental factors showed that the environmental factors influencing the change of phytoplankton community structure in summer included water temperature, nutrients (TP, TN and NO3(-) -N, NH4(+)-N) and salinity, and the structural change was the result of the interactions of different environmental factors.

[Influence of different degrees of chronic intermittent hypoxia on c-fos protein and apoptosis in rats].

OBJECTIVE: To establish different degrees and duration of animal hypoxia model of sleep apnea hypopnea syndrome according to the mechanism of intermittent hypoxia, to observe the effect of c-fos protein and apoptosis, and to explore the mechanism of nervous system injury. METHODS: By using the model of chronic intermittent hypoxia in rats, male Wistar rats (n = 72) were randomly divided into three groups: 5% of chronic intermittent hypoxia group (the fraction of oxygen volume reduced to 5% under hypoxia), 10% of chronic intermittent hypoxia group (the fraction of oxygen volume reduced to 5% under hypoxia) and control group. The levels of on c-fos protein and apoptosis of hippocampal cell in three groups were detected at the 2nd, 4th, 6th and 8th week respectively. The expression of c-fos protein in hippocampal cell was detected by immunohistochemical method and the apoptosis of hippocampal cell was detected by TUNEL. RESULTS: The relative quantity of c-fos protein and apoptotic index in CIH groups were significantly higher than that of the control group on the 2nd, 4th, 6th and 8th weeks (F were 44.52, 57.56, 24.20 and 13.18, P < 0.05), and these were higher obviously in 5% CIH group than that in 10% CIH group (P < 0.05). The expression of c-fos protein and apoptotic index in two CIH groups was different depending upon the different degree and duration of chronic intermittent hypoxia. With increased exposure time, the expression of c-fos protein and apoptotic index was high generally at first, peaked at 6th week, then down at 8th week (P < 0.05). While it in UC group was invariability in different time (P > 0.05). The correlation between the relative quantity of c-fos protein and apoptotic index in two CIH groups was positive (r were 0.816 and 0.701, P < 0.01). CONCLUSION: Moderate and severe intermittent hypoxia induced the excessive expression of c-fos protein in hippocampus, caused nerve cell apoptosis, and may play an important role in the mechanism of early brain injury of intermittent hypoxia.