Effects of biodegradable microplastics on arsenic migration and transformation in paddy soils: a comparative analysis with conventional microplastics.

The combined pollution of microplastics (MPs) and arsenic (As) in paddy soils has attracted more attention worldwide. However, there are few comparative studies on the effects of biodegradable and conventional MPs on As migration and transformation. Therefore, conventional (polystyrene, polyethylene, polyvinyl chloride) and biodegradable (polybutadiene styrene, polylactic acid, polybutylene adipate terephthalate) MPs were selected to explore and demonstrate their influences and mechanism on As migration from paddy soils to overlying water and As speciation transformation through microcosmic experiment with measuring the changes of As chemical distribution, physicochemical indexes and microbial community in paddy soils. The results showed that biodegradable MPs enhanced As migration and transformation more effective than conventional MPs during 60 d. Biodegradable MPs indirectly increased the content of As(Ⅲ) and bioavailable As by changing the microbial community structure and affecting the biogeochemical cycles of carbon, nitrogen, sulfur and iron in soils, and promoted the As migration and transformation. PBS showed the strongest promoting effect, transforming to more As(Ⅲ) (11.43%) and bioavailable As (4.28%) than control. This helps to a better understanding of the effects of MPs on As biogeochemical cycle and to clarify the ecological and food safety risks of their combined pollution in soils.

Influence of growth interruption on the morphology and luminescence properties of AlGaN/GaN ultraviolet multi-quantum wells.

The influence of growth interruption on the surface and luminescence properties of AlGaN/GaN ultraviolet multi-quantum wells (UV MQWs) is investigated. It is found that when the well and barrier layers of MQW samples are continuously grown at the same temperature, they have lower edge dislocation density and flatter surface of MQWs compared to samples with interrupted well and barrier growth. Moreover, continuous growth of well and barrier layers is more conducive to improving the luminescence efficiency of MQWs. This phenomenon is attributed to more impurity incorporation induced by the growth interruption, while a continuous growth of well and barrier can reduce surface diffusion and migration processes of atoms, reducing the defects and surface roughness of MQWs. In addition, the continuous growth of well and barrier can better control the reaction between Al and N atoms, avoiding the formation of excessively high Al content AlGaN at the well/barrier interface, thus improving the luminescence of UV MQWs.

The Effects and Mechanisms of pH and Dissolved Oxygen Conditions on the Release of Arsenic at the Sediment-Water Interface in Taihu Lake.

The pH and dissolved oxygen (DO) conditions are important environmental factors that control the migration of arsenic (As) at the sediment-water interface. This study investigates the distribution differences of reactive iron, manganese, and arsenic at the sediment-water interface under anaerobic and aerobic conditions at different pH levels. The strong buffering capacity of sediment to water pH results in a shift towards neutral pH values in the overlying water under different initial pH conditions. The level of DO becomes a key factor in the release of As from sediment, with lower DO environments exhibiting higher release quantities and rates of As compared to high DO environments. Under low DO conditions, the combined effects of ion exchange and anaerobic reduction lead to the most significant release of As, particularly under pH 9.5 conditions. The formation of amorphous ferrous sulfide compounds under low DO conditions is a significant factor contributing to increased arsenic concentration in the interstitial water. Therefore, the re-migration of endogenous arsenic in shallow lake sediments should consider the combined effects of multiple driving forces.

A bibliometric analysis of river health based on publications in the last three decades.

Rivers are a vital part of the earth's environment and the basis for human survival. River health has been widely concerned by scholars and practitioners, and the number of studies in this area is increasing. In order to examine the evolution of river health research and identify the research frontiers, a total of 675 articles were retrieved from the Web of Science Core Collection database, and CiteSpace was used for bibliometrics. The results revealed that the research on river health is multidisciplinary. Freshwater Biology and Ecological Indicators were two of the most influential journals. Researchers and institutions from America, Australia, and China were the core research forces, and a certain gap was observed between developed and developing countries in river health. The most productive institution was Michigan State University, followed by Griffith University and Hohai University. There are three development trends in river health: (1) Research scale is expanding; (2) Research methods are diversified and interdisciplinary; and (3) Evaluation index is more comprehensive and systematic. The frontier of river health had been expanded from the connotation of river health to the evaluation methods, evaluation indexes, and comprehensive river ecological research. Overall, research on river health is a well-developed and promising research field. This study provides a framework in the river health field for new researchers and helps scholars to identify further potential perspectives on collaborators, research frontiers, hotspots, and research trends.

The influence of stigma and disability acceptance on psychosocial adaptation in patients with stoma: A multicenter cross-sectional study.

Background: The stoma can cause serious physical and psychological distress to the patient, leading to an inability to live a normal life; although it effectively improves the 5-year survival rate of patients. Objective: The purpose of this study is to explore the status of stigma and disability acceptance of patients with stoma and their influences on psychosocial adaptation. Design: A multicenter cross-sectional study. Methods: A total of 259 patients with stoma in 6 hospitals from southeast China were enrolled. And this research adhered to the STROBE guideline and approved by the Ethics Committee of Fu Jian Provincial Hospital. The ostomy adjustment inventory-20、acceptance of disability scale and social impact scale were used to collect data. The hypothetical path model was tested using the SPSS version 22.0 software and AMOS version 26.0 software. Results: Stigma, disability acceptance and psychosocial adaptation was associated. The sense of stigma was severe (72.76 ± 12.73), the acceptance of disability was medium (179.24 ± 32.29) and the psychosocial adaptation was poor (38.06 ± 8.76). Also, the hypothesis model of this study fitted the data well (AGFI = 0.967>0.08; χ 2/df = 1.723, p = 0.08 > 0.05), and the results showed that disability acceptance positively affected psychosocial adaptation; while stigma negatively affected psychosocial adaptation, and disability acceptance mediated between stigma and psychosocial adaptation (p < 0.01). Conclusion: The stigma and disability acceptance of patients with stoma are serious problems that are closely related to their psychosocial adaptation. Medical staff should take some interventions based on different paths to reduce stoma patients' stigma and guide them to improve disability acceptance, thus to improve the level of psychosocial adaptation of patients with stoma.

Room temperature continuous-wave operated 2.0-W GaN-based ultraviolet laser diodes.

Temperature characteristics of near-UV laser diodes (LDs) with a lasing wavelength of 384 nm are investigated. The characteristic temperature of threshold current (T0) of the UV LDs is low. Thus, the performance of the UV LDs under continuous wave (CW) operation is not as good as under pulsed operation especially at a high injection current. In addition, it is found that self-heating is a key factor for CW characteristics of the UV LDs, where suppression of the self-heating by using thick waveguide layers can increase the critical current of thermal rollover of the UV LD's operation. A high CW output power of 2.0 W is achieved for an InGaN near-UV LD with the n-side down on a sub-mount, whose threshold current density is 1.27 kA/cm2 and the highest wall plug efficiency (WPE) is approximately 15.9% at an injection current of 1.2 A.

Spatiotemporal dynamic changes of antibiotic resistance genes in constructed wetlands and associated influencing factors.

A better understanding of the spatiotemporal dynamics and influencing factors of sulfonamide antibiotic resistance genes (ARGs) distribution in subsurface flow constructed wetlands is essential to improve the ARGs removal efficiency. The spatiotemporal dynamics of sulfonamide ARGs were explored in the vertical upflow subsurface flow constructed wetland (VUSFCW). The results showed that the absolute abundance of ARGs presented a trend of bottom layer > middle layer > top layer. The relative abundance of ARGs decreased significantly from the bottom layer to the middle layer, but increased in the top layer. The bottom layer was the main stage to remove ARGs. The absolute abundance of ARGs at each point in summer was significantly higher than that in winter. Based on the spatiotemporal distribution of ARGs, the internal mechanism of ARGs dynamic change was explored by the partial least square path analysis model. The results showed that physical-chemical factors, microorganisms and antibiotics indirectly affected the spatiotemporal distribution of ARGs mainly through mobile genetic elements. The indirect influence coefficients of physical-chemical factors, microorganisms and antibiotics on the spatiotemporal distribution of ARGs were 0.505, 0.221 and 0.98 respectively. The direct influence coefficient of MGEs on the spatiotemporal distribution of ARGs was 0.895. The results of network analysis showed that the potential host species of ARGs in summer were more abundant than those in winter. The selection mode of sulfonamide ARGs to potential hosts was nonspecific. There is a risk of sulfonamide ARGs infecting pathogens in VUSFCW. Fortunately, VUSFCW has proven effective in reducing the absolute abundance of ARGs and the potential risk of pathogens carrying ARGs. These findings provide a model simulation and theoretical basis for effectively reducing the threat of ARGs.

High and low inferior mesenteric artery ligation in laparoscopic low anterior rectal resections: A retrospective study.

Backgroud: The high or low inferior mesenteric artery (IMA) ligation in rectal cancer remains a great debate. This study retrospectively discussed the outcomes of the perioperative period, defecation and urinary function and long-term prognosis in rectal cancer patients with high or low IMA ligation. Methods: This study enrolled 220 consecutive rectal cancer cases, including 134 with high IMA ligation and 86 with low ligation. A comparison between the two groups was made for anastomotic leakage, low anterior resection syndrome (LARS), international prostate symptom score (IPSS), 5-year disease-free survival (DFS) and 5-year overall survival (OS). Results: Low-ligation group had a longer operative time, and larger intraoperative blood loss. No significant difference was noted in anastomotic leakage incidence. In multivariable analysis, the male gender and tumor located at the lower rectum were identified as risk factors for anastomotic leakage. No significant differences were observed between groups in their LARS and IPSS questionnaire responses. The high-ligation vs. the low-ligation 5-year OS and DFS were 78.3% vs. 82.4% and 72.4% vs. 76.6%, respectively, which were not statistically different. Conclusion: The ligation level of the IMA had no significant effect on the anastomotic leakage incidence, defecation, urinary function, and long-term prognosis.

Further Insights on Structural Modifications of Muramyl Dipeptides to Study the Human NOD2 Stimulating Activity.

A series of muramyl dipeptide (MDP) analogues with structural modifications at the C4 position of MurNAc and on the d-iso-glutamine (isoGln) residue of the peptide part were synthesized. The C4-diversification of MurNAc was conveniently achieved by using CuAAC click strategy to conjugate an azido muramyl dipeptide precursor with structurally diverse alkynes. d-Glutamic acid (Glu), replaced with isoGln, was applied for the structural diversity through esterification or amidation of the carboxylic acid. In total, 26 MDP analogues were synthesized and bio-evaluated for the study of human NOD2 stimulation activity in the innate immune response. Interestingly, MDP derivatives with an ester moiety are found to be more potent than reference compound MDP itself or MDP analogues containing an amide moiety. Among the varied lengths of the alkyl chain in ester derivatives, the MDP analogue bearing the d-glutamate dodecyl (C12) ester moiety showed the best NOD2 stimulation potency.

Epiphytic bacterial community enhances arsenic uptake and reduction by Myriophyllum verticillatum.

Microbes play an important role in the biotransformation of arsenic (As) speciation in various environments. Nevertheless, whether epiphytic bacteria that attached on submerged macrophytes have the potential to influence As speciation still remains unclear. In this study, sterile or nonsterile Myriophyllum verticillatum was cultured with arsenite (As(III)) or arsenate (As(V)) to investigate the impact of epiphytic bacterial community on As uptake, transformation, and efflux. Results showed that both sterile and nonsterile M. verticillatum did not display substantial As(III) oxidation, suggesting that neither M. verticillatum nor epiphytic bacterial community has the capacities of As(III) oxidation. However, sterile M. verticillatum exhibited capacity for As(V) reduction, and the presence of epiphytic bacterial community substantially enhanced the proportions of As(III) in the medium (from 39.91 to 98.44%), indicating that epiphytic bacterial community contributes significantly to As(V) reduction in the medium. The presence of epiphytic bacterial community elevated As accumulation (by up to 2.06-fold) in plants when exposed to As(V). Results also showed that epiphytic bacterial community contributed little to As(III) efflux. Quantitative PCR of As metabolism genes revealed the dominance of the respiratory As(V) reductase genes (arrA) in epiphytic bacterial community, which might play a significant role in As(V) reduction in aquatic environments. Phylogenetic analysis of the arrA genes revealed the widely distribution and diversity of As(V)-respiring bacteria. These results highlighted the substantial impact of the epiphytic bacterial community associated with submerged aquatic macrophytes on As biogeochemistry in wetland and water environments.

Bacterial community colonization on tire microplastics in typical urban water environments and associated impacting factors.

Only limited information is available on bacterial communities' dynamics on tire microplastics in urban water environments. This study exploited 16S rDNA high-throughput sequencing to characterize bacterial communities on tire microplastics, using three different tire brands and tire sizes, in two typical urban water environments, including an influent pond of constructed wetland (CW) and its subsequent effluent into a landscape river (LR) during three different periods, namely, 1 month, 3 and 6 months. Results showed that the abundance of bacterial colonization on tire microplastics will increase over time. Proteobacteria, Bacteroidetes were the dominant bacteria at a phylum level, although they exhibited dynamic changes. At a genus level, the identifiable bacteria found in tire microplastics was generally the common bacteria in wastewater discharge, such as Aquabacterium and Denitratisoma. Additionally, alpha diversity showed no significant differences in bacterial communities at the same locations. While beta diversity showed that the bacterial communities on the tire microplastics in the two locations was different. BugBase revealed that tire microplastics could support pathogenic bacteria in urban water environments. PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) indicated that the abundance of microorganisms associated with metabolism and degradation increased with time. Moreover, the ambient environmental factors were the main influencing factors of bacterial communities on tire microplastics. Herein, the contribution rate of nutrient salts (NO2-N, NO3-N, NH4-N, CODcr) was approximately 63%, and that of environmental physical factors of T and pH was 50%. While physicochemical factors, including particle size, contact angle, element content only had a slight impact. Accordingly, tire microplastics, as an emerging environmental pollutant, can act as carries for bacterial colonization and propagation, particularly harmful microorganisms. Therefore, the obtained findings can provide new insight into potential risks of harmful microorganisms that colonize tire microplastics in urban water environments.

Influence of environmental factors on arsenite transformation and fate in the Hydrilla verticillata (L.f.) royle - Medium system.

Hydrilla verticillata (L.f.) Royle has a great ability to accumulate large amounts of arsenic (As). We studied the influence of phosphorus (P), nitrogen (N), pH, and arsenite (As(III)) on As transformation and fate in the H. verticillata - medium system via orthogonal experimental design. The results showed highest plant growth was under intermediate As(III) in the medium, with Chlorophyll a and Chlorophyll b contents in plant diminishing after 96 h treatment. Exposure to high N, high As(III), intermediate P, and low pH in the medium, the highest total arsenic uptake by plants were 169.1 ± 5.5 µg g-1 dry weight, with As(III) as the predominant speciation (49.1 ± 4.8% to 88.5 ± 0.2%) in plants. Meanwhile, trace As (mainly arsenate (As(V))) was adsorbed on the surface of H. verticillata, and the adsorption amounts of As(V) increased with increasing As(III) concentrations in the medium. The dominant As species was As(V) in the medium although plant was supplied with As(III), and highest As(III) oxidation proportion in the medium would occur when low N and pH associated with high P and As(III). Collectively, As(III) uptake and transformation by H. verticillata cannot be overlooked in the biogeochemical cycling of As in aquatic environment.

Influence of epiphytic bacteria on arsenic metabolism in Hydrilla verticillata.

Microbial assemblages such as biofilms around aquatic plants play a major role in arsenic (As) cycling, which has often been overlooked in previous studies. In this study, arsenite (As(III))-oxidizing, arsenate (As(V))-reducing and As(III)-methylating bacteria were found to coexist in the phyllosphere of Hydrilla verticillata, and their relative activities were shown to determine As speciation, accumulation and efflux. When exposed to As(III), As(III) oxidation was not observed in treatment H(III)-B, whereas treatment H(III)+B showed a significant As(III) oxidation ability, thereby indicating that epiphytic bacteria displayed a substantial As(III) oxidation ability. When exposed to As(V), the medium only contained 5.89% As(III) after 48 h of treatment H(V)-B, while an As(III) content of 86.72% was observed after treatment H(V)+B, thereby indicating that the elevated As(III) in the medium probably originated from As(V) reduction by epiphytic bacteria. Our data also indicated that oxidizing bacteria decreased the As accumulation (by approximately 64.44% compared with that of treatment H(III)-B) in plants, while reducing bacteria played a critical role in increasing As accumulation (by approximately 3.31-fold compared with that of treatment H(V)-B) in plants. Regardless of whether As(III) or As(V) was supplied, As(III) was dominant in the plant tissue (over 75%). Furthermore, the presence of epiphytic bacteria enhanced As efflux by approximately 9-fold. Metagenomic analysis revealed highly diverse As metabolism genes in epiphytic bacterial community, particularly those related to energetic metabolism (aioAB), and As resistance (arsABCR, acr3, arsM). Phylogenetic analysis of As metabolism genes revealed evidence of both vertical inheritance and horizontal gene transfer, which might have contributed to the evolution of the As metabolism genes. Taken together, our research suggested that the diversity of As metabolism genes in epiphytic bacterial community is associated with aquatic submerged macrophytes which may play an important role in As biogeochemistry in aquatic environments.

Influence of environmental factors on arsenic accumulation and biotransformation using the aquatic plant species Hydrilla verticillata.

Hydrilla verticillata (waterthyme) has been successfully used for phytoremediation in arsenic (As) contaminated water. To evaluate the effects of environmental factors on phytoremediation, this study conducted a series of orthogonal design experiments to determine optimal conditions, including phosphorus (P), nitrogen (N), and arsenate (As(V)) concentrations and initial pH levels, for As accumulation and biotransformation using this aquatic plant species, while also analyzing As species transformation in culture media after 96-hr exposure. Analysis of variance and the signal-to-noise ratio were used to identify both the effects of these environmental factors and their optimal conditions for this purpose. Results indicated that both N and P significantly impacted accumulation, and N was essential in As species transformation. High N and intermediate P levels were critical to As accumulation and biotransformation by H. verticillata, while high N and low P levels were beneficial to As species transformation in culture media. The highest total arsenic accumulation was (197.2 ± 17.4) µg/g dry weight when As(V) was at level 3 (375 µg/L), N at level 2 (4 mg/L), P at level 1 (0.02 mg/L), and pH at level 2 (7). Although H. verticillata is highly efficient in removing As(V) from aquatic environments, its use could be potentially harmful to both humans and the natural environment due to its release of highly toxic arsenite. For cost-effective and ecofriendly phytoremediation of As-contaminated water, both N and P are helpful in regulating As accumulation and transformation in plants.

Dissolved organic phosphorus enhances arsenate bioaccumulation and biotransformation in Microcystis aeruginosa.

Only limited information is available on the effects of dissolved organic phosphorus (DOP) on arsenate (As(V)) bioaccumulation and biotransformation in organisms. In this study, we examined the influence of three different DOP forms (ß-sodium glycerophosphate (ßP), adenosine 5'-triphosphate (ATP), and D-Glucose-6-phosphate disodium (GP) salts) and inorganic phosphate (IP) on As(V) toxicity, accumulation, and biotransformation in Microcystis aeruginosa. Results showed that M. aeruginosa utilized the three DOP forms to sustain its growth. At a subcellular level, the higher phosphorus (P) distribution in metal-sensitive fractions (MSF) observed in the IP treatments could explain the comparatively lower toxic stress of algae compared to the DOP treatments. Meanwhile, the higher MSF distribution of arsenic (As) in M. aeruginosa in the presence of DOP could explain the higher toxicity with lower 96-h half maximal effective concentration (EC50) values. Although we observed As(V) and P discrimination in M. aeruginosa under IP treatments with high intracellular P/As, we did not find this discrimination under the DOP treatments. As accumulation in algal cells was therefore greatly enhanced by DOP, especially ßP, given its lower transformation rate to phosphate compared to ATP and GP in media. Additionally, As(V) reduction and, subsequently, As(III) methylation were greatly facilitated in M. aeruginosa by the presence of DOP, particularly GP, which was confirmed by the higher relative expression of its two functional genes (arsC and arsM). Our findings indicate that As(V) accumulation and its subsequent biotransformation were enhanced by organic P forms, which provides new insight into how DOP modulates As metabolism in algae.

Influence of algal blooms decay on arsenic dynamics at the sediment-water interface of a shallow lake.

Algal blooms decay affects the mobility, bioavailability, and toxicity of arsenic (As) in aquatic environments. The decaying process alters aquatic redox conditions and also introduces ample organic matter, conditions favorable for microbial reduction to simulate As release and As species transformation. This study investigated the role of algae (Microcystis aeruginosa (MA)) blooms decay on the dynamics of labile As and elements associated with its release, such as iron (Fe), manganese (Mn) and sulfide (S), at the sediment-water surface (SWI) of a shallow lake (Lake Taihu) in China, applying mesocosm incubation. A combined AgI/ZrO-Chelex diffusive gradients in thin films (DGT) technology was used to examine labile As, Fe, Mn, and S variations in sediments during none-MA, low-MA, and high-MA treatments. High-MA blooms decay generated strong anoxic conditions, which are favorable for the release of labile As, Fe, Mn, and S from sediment. Labile S produced from the reduction of sulfate caused by decaying MA was likely removed by labile Fe through the formation of Fe-sulfides under reducing conditions. Furthermore, this condition facilitated arsenate (As(V)) reduction to arsenite (As(III)), which was weakly adsorbed by Fe-sulfides and thus mobilized to the aqueous phase. An increase in the sediment resupply of solids As to pore water along with MA blooms decay was also revealed by the DGT-induced fluxes in sediment model, coupled with the average desorption rate constant increasing from 0.27 × 10-6 s-1 to 3.41 × 10-6 s-1, and the average response time decreasing from 7859 s to 1538 s.

Accelerated Materials Discovery Using Chemical Informatics Investigation of Polymer Physicochemical Properties and Transgene Expression Efficacy.

Quantitative approaches to structure-property relationships are critical for the accelerated design and discovery of biomaterials in biotechnology and medicine. However, the absence of definitive structures, unlike those available for small molecules or 3D crystal structures available for some proteins, has limited the development of Quantitative Structure-Property Relationship (QSPR) models for investigating physicochemical properties and biological activity of polymers. In this study, we describe a combined experimental and cheminformatics paradigm for first developing QSPR models of polymer physicochemical properties, including molecular weight, hydrophobicity, and DNA-binding activity. Quantitative Structure-Activity Relationship (QSAR) models of polymer-mediated transgene expression were then developed using these physicochemical properties with an eye towards developing a novel two-step chemical informatics paradigm for determining biological activity (e.g., transgene expression) of polymer properties as related to physicochemical properties. We also investigated a more conventional approach in which biomaterial efficacy, i.e., transgene expression activity, was directly correlated to structural representations of the polymers used for delivering plasmid DNA. Our generalized chemical informatics approach can accelerate the discovery of polymeric biomaterials for several applications in biotechnology and medicine, including in nucleic acid delivery.

[Significance of Retinol-Binding Protein Expression in Patients with Acute Myeloid Leukemia].

OBJECTIVE: To investigate the expression of retinol-binding protein (RBP) in patients with acute myeloid leukemia (AML) and its related factors. METHODS: The clinical data of 123 patients with AML from October 2012 to February 2016 and 100 healthy controls were collected and the correlation of RBP expression level with sex, French-American-British (FAB) subtypes, molecular mutations, peripheral white blood cells and long-term outcomes was analyzed. RESULTS: Compared with AML patients, the RBP expression level was significantly higher in healthy controls (61.02±34.97 vs 34.44±14.08 mg/L)(u=8.658, P<0.01). Patients with M3 showed higher RBP level (40.74±15.79 mg/L) compared with that of M4 (28.40±13.64 mg/L)(P<0.01) and M5 (31.97±15.31 mg/L)(P<0.05). Negative correlation was observed for RBP and white blood cells in patients with AML (r=-0.352, P<0.001), which was more remarkable in patients with M4 (r=-0.563, P<0.01) and M5 (r=-0.423, P<0.01). AML patients achieved complete remission (CR) (48.64±9.24 mg/L) showed higher RBP level than that before treatment (u=4.876, P<0.01), but lower than healthy controls (u=2.106,P<0.05). After CR, patients with M3 showed higher RBP level than that of non-M3 patients (54.91±5.25 mg/L vs 41.36±7.33 mg/L)(t=8.777,P<0.01). CONCLUSION: Detecting RBP expression may provide some useful information for urderstanding the pathophysiology and improving the treatment of patients with AML.

Effects of two different high-fidelity DNA polymerases on genetic analysis of the cyanobacterial community structure in a subtropical deep freshwater reservoir.

The use of molecular methods to investigate the community structure and diversity of microalgae has largely replaced the previous morphological methods that were routinely carried out by microscopy. Different DNA polymerases can lead to bias in PCR amplification and affect the downstream community and diversity analysis. In this study, two clone libraries were constructed with two different DNA polymerases, Q5 high-fidelity DNA polymerase and exTaq polymerase, to compare the differences in their capability to accurately reflect the cyanobacterial community structure and diversity in a subtropical deep freshwater reservoir, Dongzhen reservoir. The results indicated that the two cyanobacterial clone libraries constructed by using Q5 high-fidelity DNA polymerase and exTaq DNA polymerase did not show significant differences, although a slightly higher community diversity was revealed by using Q5 high-fidelity DNA polymerase. It is noteworthy that so far Q5 high-fidelity DNA polymerase was the first time to be employed in the genetic analysis of cyanobacterial community. And it is for the first time that the cyanobacterial community structure in Dongzhen reservoir was analyzed using molecular methods. Phylogenetic analysis revealed that most of the clones belonged to Cyanophyta and chloroplast, among which Cyanobium sp. Suigetsu-CR5 made up the largest fraction of cyanobacteria in winter.

Development of a Web-Enabled SVR-Based Machine Learning Platform and its Application on Modeling Transgene Expression Activity of Aminoglycoside-Derived Polycations.

OBJECTIVE: Support Vector Regression (SVR) has become increasingly popular in cheminformatics modeling. As a result, SVR-based machine learning algorithms, including Fuzzy-SVR and Least Square-SVR (LS-SVR) have been developed and applied in various research areas. However, at present, few downloadable packages or public-domain software are available for these algorithms. To address this need, we developed the Support vector regression-based Online Learning Equipment (SOLE) web tool (available at http://reccr.chem.rpi.edu/SOLE/index.html) as an online learning system to support predictive cheminformatics and materials informatics studies. RESULTS: In this work, we employed the SOLE system to model transgene expression efficacy of polymers obtained from aminoglycoside antibiotics, which allowed the results of several modeling approaches to be easily compared. All models had test set r2 of 0.96-0.98 and test set R2 of 0.79-0.84. Y-scrambling test showed the models were stable and not over-fitted. CONCLUSION: SOLE has a user-friendly interface and includes routine elements of performing QSAR/QSPR studies that can be applied in various research areas. It utilizes rational and sophisticated feature selection, model selection and model evaluation processes.