Effect of ion pair strategy on transdermal delivery of guanfacine: Which factor dominates drug permeation?

Ion pair is an effective chemical approach to promoting drug transdermal permeation, and the traditional interpretation for its enhanced permeation effect is mainly attributed to counterions altering the physicochemical properties of the drug (lipophilicity, melting point, etc.). In this work, guanfacine (GFC), a non-stimulant for anti-attention deficit and hyperactivity disorder (ADHD), was used as a model drug, and several organic or inorganic acids were designed thereby successfully constructing ion pairs. The transdermal permeation ability of ion pairs through isolated porcine skin was observed and ranked as follows: guanfacine caprylate (GFC-CA) > GFC > guanfacine laurate (GFC-LA) > guanfacine fumarate (GFC-FA) > guanfacine hydrochloride (GFC-HA) > guanfacine palmitate (GFC-PA). The effect of key physicochemical properties (octanol-water partition coefficient, molecular volume, melting point) on the transdermal permeation rate of the model drug was analyzed in detail. In addition, GFC-CA was observed to alter the lipid structure of the skin, suggesting the traditional explanation of the action of ion pair may be inadequate and underrated, and ion pair may also enhance permeation by disrupting skin structure. The intriguing phenomenon is expected to provide a novel approach to achieving precise transdermal drug delivery.

Spatial and temporal variability and risk assessment of organophosphate esters in seawater and sediments of the Yangtze River estuary.

Organophosphate esters (OPEs) as substitutes for PBDEs have been widely detected in the marine environment, while little is known about the pollution characteristics and variation of OPEs in estuarine environments with complex hydrodynamic conditions and land-based input. Yangtze River Estuary (YRE) is a typical highly urbanized and industrialized estuary, with a complex hydrological environment and geochemical behavior. This study found that the concentrations of OPEs in both seawater and sediments in the YRE were higher in spring than in summer. Alkyl OPEs were the first contributor, with TnBP and TiBP as the main components, where the contribution of alkyl OPEs had exceeded 75 % in both seawater and sediments in spring, and 60 % in summer seawater, and even 80 % in sediments. In spring, OPEs peaked in the central to southern region near the YRE. In summer, OPEs were mainly concentrated in the southern branch waterway and southern nearshore area of the YRE and showed a decreasing trend to the northeast. The OPEs in the sediments were mainly concentrated in the Yangtze River Mud Area (YREMA) and the Zhe-Min Coastal Mud Area (ZMCMA). Based on the fugacity model and principal component analysis, sediments could be released into the aquatic environment as an endogenous source, and exogenous sources were mainly municipal and industrial sewage discharge sources, urban and marine traffic discharge sources, and atmospheric deposition sources. The ecological risk analysis showed that the Σ14OPEs had exhibited a low to moderate ecological risk in the southern branch waterway and the south-central region offshore.

Design and evaluation of gastro-swelling/gastro-floating sustained-release tablets of brivaracetam for epilepsy therapy.

To prolong the absorption of the drug and achieve the effect of gastric retention, new brivaracetam tablets together with the characteristics of rapid swelling and sustained floating have been developed here. The tablets were optimized and prepared by direct compression techniques using Kollidon® SR and cross-linked polyvinylpyrrolidone (PVPP) XL as the matrix and disintegrant respectively, and carbomer 71G NF and polyethylene oxide (PEO) N60K as the gel materials to achieve sustained release effect. The characteristics of static expansion, floating time, drug release and dynamic swelling performance in vitro of the tablets were evaluated. The optimized formulations (F5 and F10) exhibited satisfactory swelling and floating properties, mechanical strength, and in vitro sustained-release characteristic with diffusion and matrix erosion mechanisms. X-ray images of beagle dogs showed that the tablet F5 could be retained in the stomach for more than 6 h. Furthermore, the pharmacokinetic studies in volunteers exhibited that the bioavailability of F5 and F10 was 95.70% (90% CI, 83.80%-109.28%) and 103.39% (90% CI, 87.61%-122.01%), respectively, relative to commercial tablets, with Tmax prolonged, demonstrating an excellent sustained-release effect. Therefore, the present system can reduce dosing frequency and improve patient compliance, which is expected to be a promising treatment option for epilepsy patients.

Complete mitochondrial genome sequence of Acromitus flagellatus and its phylogenetic relationship with related jellyfish species.

This study describes the complete mitochondrial genome sequence of the scyphozoan Acromitus flagellatus (Maas, 1903), a blooming jellyfish found in the coastal areas of Hainan, China. Its mitochondrial DNA is 16,779 bp in length and has a linear structure, comprising 13 protein-coding genes (PCGs), two rRNAs (s-rRNA and l-rRNA), and two tRNAs (trna-W-TCA and trna-M-CAT). A + T content was 65.39% (A: 29.27%, C: 16.59%, G: 18.03%, and T: 36.12%). ATG was the start codon in 11 PCGs: COX1, COX2, ATP8, ATP6, COX3, NAD2, NAD6, NAD4l, NAD1, NAD4, and COB. NAD5 and NAD3 had GTG as the start codon. TAG was the stop codon for COX2, NAD6, and COB. The other 10 PCGs were terminated by TAA. The neighbor-joining phylogenetic tree of the 15 related jellyfish species showed that A. flagellatus is closely related to Nemopilema nomurai and Rhopilema esculentum.

Analysing the influencing factors on caregivers' burden among amyotrophic lateral sclerosis patients in China: a cross-sectional study based on data mining.

OBJECTIVES: There is significant burden on caregivers of patients with amyotrophic lateral sclerosis (ALS). However, only a few studies have focused on caregivers, and traditional research methods have obvious shortcomings in dealing with multiple influencing factors. This study was designed to explore influencing factors on caregiver burden among ALS patients and their caregivers from a new perspective. DESIGN: Cross-sectional study. SETTING: The data were collected at an affiliated hospital in Guangzhou, Guangdong, China. PARTICIPANTS: Fifty-seven pairs of patients with ALS and their caregivers were investigated by standardised questionnaires. MAIN OUTCOME MEASURES: This study primarily assessed the influencing factor of caregiver burden including age, gender, education level, economic status, anxiety, depression, social support, fatigue, sleep quality and stage of disease through data mining. Statistical analysis was performed using SPSS 24.0, and least absolute shrinkage and selection operator (LASSO) regression model was established by Python 3.8.1 to minimise the effect of multicollinearity. RESULTS: According to LASSO regression model, we found 10 variables had weights. Among them, Milano-Torinos (MITOS) stage (0-1) had the highest weight (-12.235), followed by younger age group (-3.198), lower-educated group (2.136), fatigue (1.687) and social support (-0.455). Variables including sleep quality, anxiety, depression and sex (male) had moderate weights in this model. Economic status (common), economic status (better), household (city), household (village), educational level (high), sex (female), age (older) and MITOS stage (2-4) had a weight of zero. CONCLUSIONS: Our study demonstrates that the severity of ALS patients is the most influencing factor in caregiver burden. Caregivers of ALS patients may suffer less from caregiver burden when the patients are less severe, and the caregivers are younger. Low educational status could increase caregiver burden. Caregiver burden is positively correlated with the degree of fatigue and negatively correlated with social support. Hopefully, more attention should be paid to caregivers of ALS, and effective interventions can be developed to relieve this burden.

Identification of TARDBP Gly298Ser as a founder mutation for amyotrophic lateral sclerosis in Southern China.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by predominant impairment of upper and lower motor neurons. Over 50 TARDBP mutations have been reported in both familial (FALS) and sporadic ALS (SALS). Some mutations in TARDBP, e.g. A382T and G294V, have genetic founder effects in certain geographic regions. However, such prevalence and founder effect have not been reported in Chinese. METHODS: Whole-exome sequencing (WES) was performed in 16 Chinese FALS patients, followed by Sanger sequencing for the TARDBP p.Gly298Ser mutation (G298S) in 798 SALS patients and 1,325 controls. Haplotype analysis using microsatellites flanking TARDBP was conducted in the G298S-carrying patients and noncarriers. The geographic distribution and phenotypic correlation of the TARDBP mutations reported worldwide were reviewed. RESULTS: WES detected the TARDBP G298S mutation in 8 FALS patients, and Sanger sequencing found additional 8 SALS cases, but no controls, carrying this mutation. All the 16 cases came from Southern China, and 7 of these patients shared the 117-286-257-145-246-270 allele for the D1S2736-D1S1151-D1S2667-D1S489-D1S434-D1S2697 markers, which was not found in the 92 non-carrier patients (0/92) (p < 0.0001) and 65 age-matched and neurologically normal individuals (0/65) (p < 0.0001). The A382T and G298S mutations were prevalent in Europeans and Eastern Asians, respectively. Additionally, carriers for the M337V mutation are dominated by bulbar onset with a long survival, whereas those for G298S are dominated by limb onset with a short survival. CONCLUSIONS: Some prevalent TARDBP mutations are distributed in a geographic pattern and related to clinical profiles. TARDBP G298S mutation is a founder mutation in the Southern Chinese ALS population.

Fertility Does Not Alter Disease Progression in ALS Patients of Childbearing Age: A Three Centers Retrospective Analysis in Southern China.

Background: Limited data exists on the clinical features of patients with amyotrophic lateral sclerosis (ALS) during reproductive ages. Objective: Our study characterized the clinical features of ALS and the effects of pregnancy on disease progression in patients with ALS. Methods: We performed a retrospective study of female patients with ALS in three ALS research centers in southern China from 2009 to 2021. Data regarding fertility status, and clinical and genetic features, were collected. Age-matched male patients with ALS served as controls. The patients were divided into the following two subgroups: patients with symptom onset within 1 year of pregnancy and patients with symptom onset over 1 year group after pregnancy. Results: A total of 52 female and 52 matched male patients were enrolled. There were no differences in female and male patients in the mean age of symptom onset, the mean baseline ALSFRS-R score, or median reduction of ALSFRS-R score (p > 0.05). The mean age of first pregnancy was 25.57 ± 4.40) years. The mean age of first pregnancy in the over 1 year group was lower than that in the within 1 year group (p= 0.01). There was no difference in the median reduction of ALSFRS-R between the two subgroups. In the univariate analysis, diagnostic delay was highly correlated with the disease progression, with short delay representing rapid progress. No multicollinearity was found among every variable. In addition, 40.38% patients carried ALS-related gene variants. The proportion with gene mutations in the within 1 year group was higher than that in the over 1 year group (p < 0.01). Furthermore, SETX was the most frequently mutated gene in this cohort (16.67%) including 4 uncertain mutation. Conclusion: Pregnancy and fertility were not associated with disease progression. Diagnostic delay was correlated with disease progression in this cohort. In addition, SETX might be a gene of concern for ALS patients of childbearing age.

Distribution, sources, and ecological risk of organophosphate esters in the urbanized Jiaozhou Bay, East China.

Organophosphate esters (OPEs), substitutes of polybrominated diphenyl ethers, have been found in a variety of marine environmental matrices, whereas little is known about the feature and sources of seawater OPEs from the environments simultaneously affected by multiple anthropogenic activities. Jiaozhou Bay is one typical bay heavily disturbed by human activities, which was semi-enclosed and surrounded by large amounts of discharged rivers and catchments, various types of ports, and aquaculture farms. This study found that concentrations of Σ13OPEs ranged from 23.90 to 366.40 ng/L (median: 37.76 ng/L) in the seawater and from 90.15 to 1183.14 ng/L (median: 940.61 ng/L) in the inflowing river water. Tris (2-chloroisopropyl) phosphate, triethyl phosphate, and tris (2-chloroethyl) phosphate were the predominant congener, with the percentage of 43.76%, 22.80%, and 14.01%, respectively, in the bay water and 52.47%, 11.31%, and 23.66% in the river water. The overall spatial distribution was characterized by a higher concentration of Σ13OPEs and halogenated-OPEs in the nearshore sites and in the inflowing rivers, which were surrounded by urbanized areas with dense anthropogenic activities, especially along the eastern coast. Effluent discharge and vehicular and marine traffic emissions were distinguished as two main plausible sources of OPEs to Jiaozhou Bay, based on the principal component analysis and Spearman correlations. Ecological risk analysis indicated that Σ13OPEs posed a low risk to aquatic organisms in the bay and low-to-medium risks in the inflowing rivers.

Inter-annual variation and comprehensive evaluation of organophosphate esters (OPEs) in the Yellow Sea, China.

Considering the extensive production and continuous usage of organophosphate esters (OPEs) around the urbanized coasts in recent years, the inter-annual variation and the ecological risks of OPEs in the Yellow Sea (YS), China were systematically evaluated in summer 2015 and 2019. The major component of OPEs, halogenated-OPEs in 78 surface and bottom seawater samples collected from 39 locations in the YS in 2019 were compared with 62 samples at 31 sites conducted in the same periods and similar stations in 2015. The average concentration of halogenated-OPEs increased 1.57, 2.50 folds in the surface and bottom seawater, respectively, in recent 5 years. The proportion of TCPP to halogenated-OPEs exhibited an increasing trend from 56.49% in 2015 to 79.95% in 2019. The peak values of halogenated-OPEs changed from the nearshore regions (33°N-38°N) in 2015 to the nearshore and offshore regions (33°N-35°N) in 2019, implying the growing terrigenous emission sources, especially some large OPEs producers nearby the coastal zones in the northern area of Jiangsu province. The targeted halogenated-OPEs posed no significant or low ecological risks to the aquatic organisms in 2015 and 2019, however, the values of RQ showed an elevated trend in 2019. Therefore, the ecological risks of OPEs in this region still need continuous concern due to the gradually increasing OPEs usage and production.

Natural history and remarkable psychiatric state of late-onset amyotrophic lateral sclerosis in China.

OBJECTIVE: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease affecting motor neurons. The proportion of late-onset ALS in China were low and may have distinct clinical and genetic manifestations. We aimed to investigate the natural history and remarkable psychiatric state of ALS with age at onset over 60 years in China. MATERIALS AND METHODS: We collected all ALS cases from 2017 to 2020 in our center and focused on late-onset ALS patients particularly, by analyzing the clinical data, including the ALS onset and disease progression. Anxiety, depression, cognitive function, and sleep quality were assessed to reflect the psychiatric state. RESULTS: A total of 193 late-onset ALS patients were included in this study. The median age at onset of late-onset ALS was 65 years with the quartile from 62 to 68 years. When compared with 446 non-late-onset ALS, late-onset ALS showed distinct clinical presentation, with lower ALS Functional Rating Scale-Revised at diagnosis and faster rate of progression. Remarkably, late-onset ALS were suffering from worse psychiatric state, including serious anxiety and depression, as well as worse cognitive function with sleep quality. The abnormal psychiatric state was more pronounced in female patients of late-onset. CONCLUSIONS: In the current study, ALS patients with late-onset showed unique clinical features. Severe psychiatric conditions and faster progression in the early stage of the disease of late-onset ALS indicated the need for more social and psychiatric support in this population.

The distinct manifestation of young-onset amyotrophic lateral sclerosis in China.

OBJECTIVE: Young-onset amyotrophic lateral sclerosis (ALS) refers to ALS patients with initial symptoms earlier than 45 years, representing a novel disease pattern. We aim to summarize the clinical and genetic features of 102 young-onset ALS patients in China. Methods: Clinical information and blood samples were collected from all registered patients, and we performed next generation sequencing techniques in an ALS customized panel to detect ALS-related genes. Results: A total of 95 sporadic ALS and seven familial ALS were involved in this study. Young-onset ALS showed male prevalence and had more spinal onset. With 44 patients carrying one or more variants, mutations in SPG11, ALS2, and SETX were the most frequent, followed by FUS variants. Other prevalent genes like SOD1, TARDBP, and C9ORF72 were relatively rare in young-onset patients. Conclusions: Our study highlighted distinct clinical manifestation and genetic background in young-onset ALS patients in China. These features should be verified in further investigations in other populations.

Key Molecules and Pathways Underlying Sporadic Amyotrophic Lateral Sclerosis: Integrated Analysis on Gene Expression Profiles of Motor Neurons.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by progressive loss of motor neurons. The complex mechanisms underlying ALS are yet to be elucidated, while the lack of disease biomarkers and therapeutic options are associated with the poor prognosis of ALS patients. In this study, we performed bioinformatics analysis to clarify potential mechanisms in sporadic ALS (sALS). We compared three gene expression profiles (GSE18920, GSE56500, and GSE68605) of motor neurons obtained from sALS patients and healthy controls to discover differentially expressed genes (DEGs), and then performed integrated bioinformatics analyses to identify key molecules and pathways underlying sALS. We found that these DEGs were mainly enriched in the structure and functions of extracellular matrix (ECM), while functional enrichment in blood vessel morphogenesis was less correlated with motor neurons. The clustered subnetworks of the constructed protein-protein interaction network for DEGs and the group of selected hub genes were more significantly involved in the organization of collagen-containing ECM. The transcriptional factors database proposed RelA and NF-κB1 from NF-κB family as the key regulators of these hub genes. These results mainly demonstrated the alternations in ECM-related gene expression in motor neurons and suggested the role of NF-κB regulatory pathway in the pathogenesis of sALS.

River algal blooms are well predicted by antecedent environmental conditions.

River algal blooms have become a challenging environmental problem worldwide due to strong interference of human activities and megaprojects (e.g., big dams and large-scale water transfer projects). Previous studies on algal blooms were mainly focused on relatively static water bodies (i.e., lakes and reservoirs), but less on the large rivers. As the largest tributary of the Yangtze River of China and the main freshwater source of the South-to-North Water Diversion Project (SNWDP), the Han River has experienced frequent algal blooms in recent decades. Here we investigated the algal blooms during a decade (2003-2014) in the Han River by two gradient boosting machine (GBM) models with k-fold cross validation, which used explanatory variables from current 10-day (GBMc model) or previous 10-day period (GBMp model). Our results advocate the use of GBMp due to its higher accuracy (median Kappa = 0.9) and practical predictability (using antecedent observations) compared to GBMc. We also revealed that the algal blooms in the Han River were significantly modulated by antecedent water levels in the Han River and the Yangtze River and water level variation in the Han River, whereas the nutrient concentrations in the Han River were usually above thresholds and not limiting algal blooms. This machine-learning-based study potentially provides scientific guidance for preemptive warning and risk management of river algal blooms through comprehensive regulation of water levels during the dry season by making use of water conservancy measures in large rivers.

Cocaine-induced structural and functional impairments of the glymphatic pathway in mice.

The glymphatic system plays a central role in the clearance of extracellular wastes from the brain. Cocaine exposure can lead to pathologies that affect the entire brain, resulting in addictive disorders involving motivational and cognitive impairment. However, it remains unknown whether cocaine exposure impairs glymphatic function. In the present study, using a mouse model of noncontingent cocaine exposure, we evaluated glymphatic function including cerebrospinal fluid (CSF)-interstitial fluid (ISF) exchange and solute clearance during repeated exposures and withdrawal. We found that cocaine treatment, both during repeated exposure and withdrawal, significantly induced widespread astrogliosis and reduced cerebral blood flow (CBF), cerebrovascular pulsatility, and aquaporin-4 (AQP4) polarity. Glymphatic function was greatly impaired in mice after cocaine treatment, as evidenced by reduced CSF influx from paravascular pathways into the brain parenchyma and decreased efflux of interstitial molecules out of the parenchyma. These findings provide evidence that cocaine exposure impairs the clearance of wastes from the brain, which may contribute to the development of neurocognitive disorders in patients with drug addictions.

[Community Diversity of Eukaryotic Nano-phytoplankton in Yellow Sea Using DNA Metabarcoding Technology Based on Multiple Amplicons].

Eukaryotic nano-phytoplankton plays an indispensable role in energy flow, material circulation, and stability maintenance of marine ecosystems. In this research, DNA metabarcoding technology was applied to elucidate the distribution features of eukaryotic nano-phytoplankton in the Yellow Sea for the first time. The community structure and diversity of eukaryotic nano-phytoplankton were compared based mainly on amplicons of internal transcribed spacer (ITS), 18S rDNA V4 and 18S rDNA V9. Analysis of the correlation between diversity and temperature/salinity was performed as well. The following results were noted. ① Higher proportions of Chlorophyta were obtained based on the ITS region compared with other two amplicons, while the relative abundance of Dinoflagellata was larger when 18S rDNA V4 and 18S rDNA V9 regions were applied.②The abundance-based coverage estimators (ACE), Chao1, Shannon diversity, and Simpson diversity indices were significantly higher based on the amplicon of 18S rDNA V9 than those based on ITS and 18S rDNA V4. The numbers of phyla, classes, order, and families were larger when the 18S rDNA V9 region was applied.③ Based on the amplicons of ITS, 18S rDNA V4, and 18S rDNA V9, the Shannon diversity index showed a significant positive correlation with temperature (P<0.01), indicating that as the temperature increased, the diversity of the eukaryotic nano-phytoplankton increased. The tendency was opposite for salinity, however. With an increase in salinity, the Shannon diversity index decreased significantly (P<0.05). This research compared the community structure and diversity of eukaryotic nano-phytoplankton under different amplicons and will provide a scientific basis for ecological studies of eukaryotic nano-phytoplankton, monitoring of biodiversity and dynamic changes of biological resources, and sustainable development.

Complete mitochondrial genome sequence of Parumbrosa polylobata.

The complete mitochondrial genome sequences of giant jellyfish Parumbrosa polylobata, a scyphozoan species inhabiting the Yellow Sea cold bottom water in China, is firstly described and analyzed in this research. It is 16,809 bp in length with a linear mitochondrial DNA. The base composition of the genome with A + T bias is 69.7%. There are 13 protein-coding genes (PCGs), 2 tRNAs, and 2 rRNAs. Another two special PCGs, ORF360 and ORF147 with telomeres were found at both ends. The neighbor-joining (NJ) phylogenetic tree among the related 13 species showed that P. polylobata is close to Aurelia spp.

Complete mitochondrial genome sequence of Aequorea coerulescens.

The complete mitochondrial genome sequences of hydromedusa Aequorea coerulescens, a dominant giant jellyfish distributing in the Yellow Sea and northern East China Sea, China, is first reported in this research. Its mitochondrial DNA has 14,804 bp in length with a linear structure, containing 13 protein-coding genes (PCGs), 2rRNA (s-rRNA and l-rRNA), and 2tRNA (trnaW-TGA and tranM-AGT). The A + T content of the whole base composition of the genome is 72.8% (A: 30.15%; C: 12.33%; G: 14.87%; T: 42.64%). ATG, ATA, and ATT are start codons in five (ATP8, ATP6, COX3, NAD6, NAD4l), four (NAD2, NAD5, NAD1, COX1) and two PCGs (NAD3, NAD4), respectively. COB and COX2 began with GTG and CAA as start codon, respectively. TAA and ATA were the stop codon of ATP6 and NAD5 as well as NAD2 and NAD4, respectively. However, other PCGs were terminated with different stop codons. The NJ phylogenetic tree among the related 15 jellyfish species showed that A. coerulescens is close to Hydra spp.

[Eukaryotic Micro-plankton Community Diversity and Characteristics of Regional Distribution in the Yellow Sea by ITS High-throughput Sequencing].

Eukaryotic micro-plankton plays a key role in the marine biotic community and in maintaining the stability of the marine ecosystem. In order to determine the diversity and characteristics of eukaryotic micro-plankton in the Yellow Sea, Illumina high-throughput sequencing, based on gene markers of ITS, was conducted. An analysis of the relationship between community structure and environmental factors was conducted as well. The results are summarized in the following. ① Various of species of fungi, phytoplankton, and zooplankton were obtained by high-throughput sequencing technology; for OTUs, the order is fungi > phytoplankton > zooplankton, and for reads, the order is fungi > zooplankton > phytoplankton. ② In different waters, species abundance and diversity differed from each other. The Ace index and Chao1 index demonstrated an ordering of southern Yellow Sea > northern Yellow Sea > northern East Sea > Cold Water Mass; however, for the Simpson index and Shannon-Wiener index, the tendency followed the order of northern East Sea > northern Yellow Sea > southern Yellow Sea > Cold Water Mass. Species abundance and diversity in the Cold Water Mass were lowest. ③ The reads and OTUs of fungi, phytoplankton, and zooplankton increased as temperature rose. The reads and OTUs of fungi increased as salinity increased, while there was an opposite trend for phytoplankton and zooplankton. Latitude was another significant factor. In the range of 30° to 40° north latitude, the Shannon-Wiener index for fungi and zooplankton indicated an increasing tendency with an increase in latitude, while the Shannon-Wiener index for phytoplankton showed an opposite trend. With a greater distance from the coast, the Shannon-Wiener index of fungi, phytoplankton and zooplankton was lower. This is the first study that amplifies the use ITS in the research of marine eukaryotic micro-plankton, giving an enriched understanding of eukaryotic micro-plankton. The feasibility of applying high-throughput sequencing technology in the sea is proven, and this will provide a reference for other researchers.

[Community Structure Characteristics of Eukaryotic Planktonic Algae in Liaohe River Through High-throughput Sequencing].

Eukaryotic phytoplankton plays an important ecological function in river ecosystem. The 18S rRNA gene V4 variable region of the environmental samples in Liaohe river was sequenced by using 454 pyrosequencing technology. The reprehensive sequences of OTUs were annotated, and then the OTUs list was compared to the species list obtained by microscope observation. The phylogenetic tree was constructed based on the reprehensive sequences of OTUs and 18S rRNA genes of eukaryotic phytoplankton algae obtained from GenBank. The community structure characteristics of eukaryotic phytoplankton and its environmental impact indicators were further studied. In this study, we got 167901 high-quality sequences of 18S rRNA gene V4 region. These sequences were annotated to 424 OTUs, including 134 eukaryotic algae. The results of the high-throughput sequencing showed that bacillariophyta and chlorophyta were the dominant groups of the total phyla. The high-throughput sequencing also revealed the presence of Charophyta, Cryptophyta, Haptophyta and Chrysophyceae which were not observed by optical microscope. The phylogeny analysis clustered the Cryptophyta and Pyrroptata at phylum level. The different genera of Cryptophyta and part of families or genera of Pyrroptata were clustered and distinguished by phylogeny analysis. The results of RDA showed that NH4+-N, PO43-P and NO3- were the most important environmental factors that affected the community structure. This study provided a new perspective to understand the diversity, community structure and influence factors of eukaryotic phytoplankton in Liaohe river. The study also indicated that high-throughput sequencing has great application potential in investigation of phytoplankton and the water environment quality assessment in Liaohe river.

[Impact of Talc Ore Mining on Periphyton Community Structure and Water Environment].

In order to explore the impact of Talc ore mining on aquatic ecosystems, periphyton communities and environmental factors from control portion, impacted portion and recovery portion separately were investigated and analyzed. Samples were collected from upstream Tanghe River (an important tributary of Tazi River) in November 2015, April 2016, and July 2016. Mann-Whitney U test was applied to compare the differences in environmental factors and periphyton community structures among three portions. Spearman correlation analysis, canonical correspondence analysis, and t-value biplot analysis were used to determine the relationship between the environmental factors and periphyton community structures. In the control and recovery portions, mass concentrations of magnesium (Mg), selenium (Se), arsenic (As), iron (Fe), molybdenum (Mo), bicarbonate ion (HCO3-), nitrate ion (NO3-), power of hydrogen (pH) and electric conductivity (EC), were the highest, and in the impacted portion, mass concentrations of potassium(K), sodium (Na), strontium (Sr), barium (Ba), silicon dioxide (SiO2), and dissolved oxygen (DO) were the lowest. The mass concentrations of Mg, Mo, As, EC, and HCO3- were significantly different (P<0.05) among the three portions. In control and recovery portions, the periphyton density, species richness, diatom siltation index, and relative abundance of Achnanthes sp. were the highest, while in the impacted portion, the percentage of handle diatom, the relative abundance of Surirella sp., and relative abundance of Navicula sp. were the lowest. Species richness of periphyton was significantly different (P<0.05) among the three portions. In summary, Mg, EC, and HCO3- from Talc Ore mining had significant impacts on periphyton assemblage structure.