[Analysis of the Spatiotemporal Distribution of Algal Blooms and Its Driving Factors in Chaohu Lake Based on Multi-source Datasets].

Eutrophication and harmful algae blooms are one of the common ecological and environmental problems faced by freshwater lakes all over the world. As a typical inland freshwater lake, Chaohu Lake exhibits a high level of eutrophication and algae blooms year-round and shows a spatiotemporal difference in different regions of the lake. In order to understand the basic regularity of the development and outbreak of algal blooms in Chaohu Lake, the data from the comprehensive water observation platform and remote sensing were integrated to obtain the spatiotemporal distribution of algal blooms from 2015 to 2020. Then, an evaluation model based on Boosted Regression Trees (BRT) was constructed to quantitatively assess the importance and interactions of various environmental factors on algal blooms at different stages. The results indicated that:① The occurrence of algal blooms in Chaohu Lake exhibited significant seasonal variations, with the cyanobacteria beginning to recover in spring and bring about a light degree of algal blooms in the western and coastal areas of Chaohu Lake. The density of cyanobacteria reached its maximum in summer and autumn, accompanied by moderate and severe degrees of algal bloom outbreaks. ② During the non-outbreak period, the variation in the cyanobacteria density was greatly affected by physical and chemical factors, which explained 80.3% of the variance in the change in cyanobacteria density. The high concentrations of dissolved oxygen content in the water column and the weak alkalinity (7.2-7.6) and appropriate water temperature (about 3℃) provided a favorable environmental condition for the breeding and growth of cyanobacteria. In addition, the onset of algal blooms was closely related to the air temperature steadily passing through the threshold. According to the statistics, the date of first outbreak of algal blooms in Chaohu Lake was 11 days or so after the air temperature steadily remained above 7℃. ③ During the outbreak period, the occurrence of algal blooms was influenced by the combination of cyanobacterial biomass and meteorological conditions such as temperature, wind speed, and sunshine duration. The cumulative contribution ratio of the four factors was as high as 95%, and each factor had an optimal interval conductive to the outbreak of algal blooms. Furthermore, the results of multi-factor interaction analysis indicated a larger probability of the outbreak of algal blooms in Chaohu Lake under the combined effect of high cyanobacteria density, suitable temperature, and the breeze. This study analyzed and revealed the spatiotemporal characteristics and the dominant influencing factors of algal blooms in Chaohu Lake at different stages, which could provide the scientific basis for the prediction, early warning, and disposal of algal blooms under the context of climate change.

Effects of ant nesting on seasonal dynamics of soil N2O emission in a secondary tropical forest.

We assessed the seasonal dynamics of N2O emission in ant nests soils in secondary tropical Millettia leptobotrya forest of Xishuangbanna by using the static chamber-gas chromatography method, and determined the lin-kages between ant-mediated changes in soil properties (e.g., carbon pool, nitrogen pool, and temperature and humidity) and N2O emission. The results showed that ant nesting significantly affected soil N2O emission. The ave-rage soil N2O emission (0.67 mg·m-2·h-1) in ant nests was 40.2% higher than that in the control (0.48 mg·m-2·h-1). N2O emission in ant nests and the control showed substantial seasonal variation, with higher rate in June (0.90 and 0.83 mg·m-2·h-1, respectively) than that in March (0.38 and 0.19 mg·m-2·h-1, respectively). Ant nesting significantly increased the values (7.1%-74.1%) of moisture, temperature, organic carbon, total nitrogen, hydrolytic nitrogen, ammonium nitrogen, nitrate nitrogen, and microbial biomass carbon, but decreased pH (9.9%) compared with the control. Results of structural equation model showed that soil N2O emission was promoted by soil C and N pool, temperature, and humidity, but was inhibited by soil pH. The explained extents of soil nitrogen pool, carbon pool, temperature and humidity, and pH for N2O emission changes were 37.2%, 27.7%, 22.9% and 9.4%, respectively. Therefore, ant nesting regulated N2O emission dynamics by changing nitrification and denitrification substrates (e.g., nitrate and ammoniacal nitrogen), carbon pool, and micro-habitat (temperature and moisture) of soil in the secondary tropical forest.

[Mechanism of ß-carboline alkaloids inhibiting migration and invasion of SGC-7901 cells].

To explore the mechanism of ß-carboline alkaloids inhibiting the migration and invasion of SGC-7901 cells and its correlation with FAK gene expression,CCK-8 method was used to determine the inhibitory rate of ß-carboline alkaloids on the proliferation of gastric cancer SGC-7901 cells under different concentrations.The effect of ß-carboline alkaloids on the migration and invasion of SGC-7901 cells was used by Transwell compartment.Detection of mRNA and protein expression of FAK genes were used by qRT-PCR and Western blot.Then si-FAK-1051 recombinant plasmid was transfected into SGC-7901 cells.FAK gene silencing effect was identified by qRT-PCR and Western blot technique again.Finally,the effects of FAK gene silencing on proliferation and migration of gastric cancer SGC-7901 cells were detected by CCK-8 kit and Transwell chamber assay respectively.With the increase of the concentration ofß-carboline alkaloids,the inhibitory rate of SGC-7901 cells in human gastric cancer cells increased gradually,with IC5013.364 mg·L-1.The number of SGC-7901 cells of Transwell compartment in the positive experimental group(5-FU,5 mg·L-1) and the ß-carboline alkaloids group decreased significantly(P<0.01) and the number of SGC-7901 cells in the ß-carboline alkaloids group was significantly lower than that in the positive experimental group(P<0.01).Compared with the blank control group,the mRNA and protein expression level of FAK genes in the positive experimental group was significantly lower than that in the experimental group of ß-carboline alkaloids(P<0.05).After transfection of si-FAK-1051 into gastric cancer SGC-7901 cells,the expression of mRNA and protein of FAK gene was significantly down regulated(P<0.05).SGC-7901 cell proliferation and cell migration ability also decreased significantly(P<0.05).ß-carboline alkaloids are more effective than 5-FU in inhibiting migration and invasion of gastric cancer SGC-7901 cells,and the mechanism may be related to the inhibition of mRNA and protein expression of FAK gene by ß-carboline alkaloids.

[Therapeutic effect of hepatic artery infusion with albendazole microspheres on hepatic alveolar echinococcosis in rats].

OBJECTIVE: To observe therapeutic effect of hepatic artery infusion of albendazole solid dispersion-chitosan microspheres on hepatic alveolar echinococcosis (HAE) in rats. METHODS: After the establishment of hepatic alveolar echinococcosis model, 30 rats were randomly divided into control group (A), blank microspheres group (B), and albendazole microspheres group (C) with 10 rats in each group 0.3 ml normal saline, 27mg/kg blank microspheres and 2.7 mg/kg albendazole solid dispersion-chitosan microspheres with 0.3 ml normal saline were injected through hepatic artery of rats in the groups of A, B and C, respectively. At 1 d, 3 d, 7 d, 14 d, and 42 d after injection, venous blood were collected, and white blood cells (WBC), aspartate aminotransferase (AST), and alanine aminotransferase(ALT) were evaluated. All the rats were sacrificed on 42 d after injection, and HAE pathological changes were observed. RESULTS: Transient elevation of white blood cells was observed in all groups at 1 d after infusion [Group A (86.11 +/- 19.14) x 10(9)/L, B (117.11 +/- 21.76) x 10(9)/L, C (118.11 +/- 24.52) x 10(9)/L], at 7d WBC fell to normal level [A (7.85 +/- 6.57)x10(9)/L, B (11.73 +/- 4.85) x 10(9)/L, C (8.49 +/- 136)x10(9)/L]. In groups B and C, AST, ALT reached their peaks on day 3 after infusion [B: AST (193.15 +/- 21.57) U/L, ALT (78.39 +/- 9.78) U/L; C: AST (189.91 +/- 14.06) U/L, ALT (88.43 +/- 9.23) U/L], and decreased to normal level at 14d after infusion [B: AST (109.31 +/- 15.48) U/L, ALT(47.855 +/- 9.49) U/L; C: AST(105.37 +/- 8.16) U/L, ALT (49.53 +/- 6.75) UL]. Histopathological examination at 42d after infusion showed that in groups A and B structure of the cysts was virtually normal, but in group C most cysts showed necrosis in germinal layer. CONCLUSION: Hepatic artery infusion with albendazole solid dispersion-chitosan microspheres shows certain therapeutic effect on hepatic alveolar echinococcosis in rats.

[Clinical analysis of families with generalized epilepsy with febrile seizures plus].

OBJECTIVE: To investigate the clinical phenotypes and hereditary patterns of the generalized epilepsy with febrile seizures plus (GEFS+). METHODS: Detailed family trees were constructed by inquire and physical examinations for the probands of the 15 pedigrees of GEFS+. Some patients received electroencephalography, cranial CT or MRI examination. The seizures and epilepsy syndromes were classified according to the 2001 Seizure International Classification. The clinical data of GEFS+ were reviewed. RESULTS: The 15 families consisted of 196 individuals. Seventy-five individuals were confirmed with epilepsy. The phenotypes of 64 out of the 75 patients with epilepsy conformed to GEFS+. The 64 patients included 38 males and 26 females (1 deceased) and there was no gender difference in the morbility of GEFS+. The age at onset was all in childhood. GEFS+ had a diversity of phenotypes. Febrile seizures (FS) were confirmed in 44 patients, FS and myoclonic seizure in 1, febrile seizures plus (FS+) in 13, FS+ and absence seizure in 2, FS+ and myoclonic seizure in 1, and FS+ and focal seizure in 3. CONCLUSIONS: The heterogeneity of phenotypes and genetics may be the hallmarks of GEFS+. FS and FS+ are common phenotypes while FS+ and absence seizure, FS+ and myoclonic seizure, and FS+ and focal seizure are rare. If one of the parents is affected in a GEFS+ family, the susceptibility of their children to GEFS+ is the same no matter what gender of their children is. It is speculated that the hereditary pattern of GEFS+ conforms to autosomal dominant inheritance.