[Distribution Characteristics and Release Fluxes of Phosphorus Forms in Xiangxi Bay Sediments in the Three Gorges Reservoir Before and After Impoundment].

The sediment storage environment in tributaries has been altered by impoundment of water in the Three Gorges Reservoir area, affecting the distribution of phosphorus forms in sediment and processes at the sediment-water interface. Through collection of sediment and overlying water samples in Xiangxi Bay in August 2016 (before impoundment) and October (after impoundment), the distribution characteristics of sedimentary phosphorus and the environmental conditions of storage before and after impoundment were analyzed. Fluxes of PO43--P at the sediment-water interface were also estimated. Results show that pH increased, alkalinity and reducibility were enhanced, and Eh in sediments decreased after impoundment. The relative content of phosphorus in sediments changed as follows:NaOH-P > HCl-P > OP to HCl-P > OP > NaOH-P; this could be attributed to changes in the depositional environment. Compared to pre-impoundment values, TP values after impoundment in sediment, overlying water ρ(PO43--P), and interstitial water ρ (PO43--P) were 1.3 times, 3.7 times, and 8.3 times higher, increasing the risk of nutrient release in sediments of Xiangxi Bay. The manifestation of PO43--P in sendiments of Xiangxi River generally is "source" pre-impoundment and post-impoundment, but the PO43--P diffusive flux increased from -0.0029-0.0059 mg·(m2·d)-1 pre-impoundment to 0.0067-0.1071 mg·(m2·d)-1 post-impoundment. The release of phosphorus from sediments at the bottom of Xiangxi Bay increased after impoundment.

[Effect of the Rainfall on Extinction of Cyanobacteria Bloom and Its Mechanism Analysis].

There were three rainfall events with different intensity in the Xiangxi Bay (XXB) from May 24 to June 2 in 2016. The factors such as hydrodynamics, water temperature, optical properties, and chlorophyll a concentrations during the rainfall events were analyzed. During the May 27 moderate rain period, the upstream flow of the reservoir bay increased by 1.9 times and the average mixing layer depth in the whole reservoir increased 8.2 m, compared to those before the rainfall event. During the June 1 light rain period, the average mixing layer depth in the whole reservoir increased 1.6 m and the average chlorophyll concentration reduced 2.02 µg·L-1, compared with those before the rainfall event. During the June 2 heavy rain period, the upstream flow of the reservoir bay increased by 4 times, the average mixing layer depth in the whole reservoir increased 7.9 m and the average chlorophyll concentration reduced 14.64 µg·L-1, compared with those before the rainfall event. The algae moved from the upstream to the downstream with water that reduced the concentration of algae in the XXB. The water temperature stratification weakened during the rain event and the average mixing layer depth in the whole reservoir increased, destroying the algal growth environment. After the rainfall, under suitable light and temperature conditions for 2-3 d, the water temperature stratification of the reservoir was recovered and rapid growth and reproduction of algae occurred. As a result, the chlorophyll concentrations in the reservoir increased. Rainfall has a periodic inhibitory effect on the outbreak of algal blooms; however, it cannot fundamentally solve the problem of tribal bay blooms.

[Spatial Difference and Causes Analysis of the δ15 N of Suspended Particulate Matter in the Lancang River Basin].

The influence of cascade hydropower construction on the migration and transformation of raw material and ecological problems in the Lancang River Basin is of concern to scholars domestically and internationally. Based on stable isotope technology, this study analyzed the spatial distribution of nitrogen in the Lancang River Basin and explained the cause of this distribution. The results showed that the range of dissolved inorganic nitrogen (DIN) was 0.28-0.60mg·L-1, and that of DIN in the downstream area of the Lancang River was 0.39-1.15mg·L-1. The range of suspended particulate matter δ15 N in the upstream area of this river was 4.52‰-6.72‰, and that in the downstream reservoir section was heavier than that in the upstream reservoir, which varied between 2.3‰ and 11.8‰. This study used Isosource to analyze the source of suspended particulate matter. The results showed that industrial wastewater and sewage, soil organic matter, atmospheric sedimentation, and agrochemicals are the main sources of suspended particulate matter, and their respective total contribution rates are 42.43%, 22.38%, 18.16%, and 17.03%. At the same time, the δ15 N of suspended particulate matter in Xiaowan, Manwan, and Dachaosan dams downstream of the Lancang River were influenced by algal assimilation, it leads to a reduction in the number of δ15 N of suspended particles.

[Expression of sCD40L in peripheral blood and NF-κBp65 in PBMC of patients with acute progressive cerebral infarction].

AIM: To study the expressional changes of soluble CD40 ligand(sCD40L) in peripheral blood serum and nuclear factor-κB (NF-κB) p65 in peripheral blood mononuclear cells (PBMC) of patients with acute progressive cerebral infarction(APCI). METHODS: We selected ninety-nine patients getting APCI less than 7 d of the onset as APCI group by prospective method. Each 100 cases of patients with acute cerebral infarction(ACI) in the same and with cerebral arteriosclerosis(CAS) in the outpatient were respectively selected as ACI and CAS group. The expressional changes of sCD40L in peripheral blood serum and NF-κBp65 in PBMC of patients with CAS on admission, of patients with APCI and ACI when in hospital, on the course of seventh day, of fourteen and of thirtieth were detected respectively. RESULTS: The expression of sCD40L in peripheral blood serum and NF-κBp65 in PBMC of patients of ACI group on admission were obviously higher all than that of CAS group (P<0.05); The expression of sCD40L in peripheral blood serum and NF-κBp65 in PBMC of patients of APCI group when in hospital, on the course of seventh day, of fourteen and of thirtieth were obviously higher all than that of ACI group (P<0.05 ). CONCLUSION: The inflammatory and apoptotic mechanism mediated by expressional excessive increase of CD40-CD40L signal passage and NF-κB in PBMC might be one of the molecular biology mechanisms of onset and progress for APCI.

Neuropeptide Y polymorphisms and ischemic stroke in Chinese population.

BACKGROUND: Stroke is the second most common cause of death in developed countries and a major cause of adult disability and mortality worldwide. New data strongly suggest that neuropeptide Y (NPY) may be a candidate gene for ischemic stroke. METHODS: We investigated 450 ischemic stroke patients and 423 healthy controls matched for sex and age in a Han Chinese population. Three functional polymorphisms (-883TGins/del, -602G/T and -399 T/C) located in NPY gene promoter were genotyped using DNA sequencing methods. RESULTS: Of 3 NPY polymorphisms investigated in our study, the -399CC genotype (OR: 1.699, 95% CI: 1.124-2.567, P=0.011) and the -399C allele (OR: 1.254, 95% CI: 1.031-1.524, P=0.023) were more frequent among ischemic stroke patients than in controls, especially in the small vessel disease (SVD) subtype patients. The similar results were observed in multivariable logistic regression analysis. Haplotype analysis revealed that the -883ins/-399C haplotype was a risk marker for ischemic stroke (P=0.008). CONCLUSIONS: The C allele of -399 T/C polymorphism in the promoter regions of NPY is an independent risk factor for ischemic stroke, suggesting that NYP system may involve in the mechanisms of stroke pathology.