Two new diatom species of the genus Gomphonemopsis (Bacillariophyceae) from the coast of China and two new combinations for the genus.

Two new diatom species belonging to the genus Gomphonemopsis are described, Gomphonemopsisnanasp. nov. and Gomphonemopsisgaoisp. nov. These two species were compared in detail with congeners. Gomphonemopsisnana is distinguished by its high stria density and small size. This species was found so far to be epiphytic only on the eelgrass collected from Qingdao Bay (Yellow Sea). Gomphonemopsisgaoi is characterized by its isopolar valves, simple proximal raphe endings and acutely rounded apices. This taxon was separated from the exoskeleton of marine copepods sampled from the Futian Mangrove Nature Reserve (South China Sea). In addition, two new combinations, Gomphonemopsisoahuensis (Hustedt) Lang Li, Yuhang Li & Changping Chen, comb. nov. and Gomphonemopsisplatypus (Østrup) Lang Li, Yuhang Li & Junxiang Lai, comb. nov. are proposed. This study increases the records and knowledge of Gomphonemopsis along the coast of China.

Resting cell formation in the marine diatom Thalassiosira pseudonana.

Resting cells represent a survival strategy employed by diatoms to endure prolonged periods of unfavourable conditions. In the oceans, many diatoms sink at the end of their blooming season and therefore need to endure cold and dark conditions in the deeper layers of the water column. How they survive these conditions is largely unknown. We conducted an integrative analysis encompassing methods from histology, physiology, biochemistry, and genetics to reveal the biological mechanism of resting-cell formation in the model diatom Thalassiosira pseudonana. Resting-cell formation was triggered by a decrease in light and temperature with subsequent catabolism of storage compounds. Resting cells were characterised by an acidic and viscous cytoplasm and altered morphology of the chloroplast ultrastructure. The formation of resting cells in T. pseudonana is an energy demanding process required for a biophysical alteration of the cytosol and chloroplasts to endure the unfavourable conditions of the deeper ocean as photosynthetic organisms. However, most resting cells (> 90%) germinate upon return to favorable growth conditions.

The allelopathic potential of red macroalga Pyropia haitanensis solvent extracts on controlling bloom-forming microalgae: Insights into the inhibitory compounds.

Various strategies have been explored to mitigate the impact of harmful algal blooms (HABs). While chemical and physical methods have traditionally been employed to regulate microalgal growth, their prolonged adverse effects on the ecosystem are a cause for concern. Recognizing the integral role of macroalgae within the ecosystem, this study reveals the anti-algal properties of solvent-based extracts derived from the red macroalga Pyropia haitanensis as a means of preventing microalgal blooms. In our investigation, we initially assessed the growth-inhibitory effects of methanol and acetone extracts from P. haitanensis on five microalgae known to contribute to bloom-formation. Significantly reduced growth was observed in all microalgal species when inoculated with both methanol and acetone extracts. Further analysis revealed the effectiveness of the methanol extract (ME), and further fractionation with petroleum ether (PE), ethyl acetate (EA), and n-butanol (NB) for testing against Skeletonema costatum and Pseudo-nitzschia pungens. The methanol fractions exhibited strong inhibition, resulting in the complete elimination of both microalgae after 96 hours of exposure to PE, EA, and NB extracts. Gas Chromatography-Mass Spectroscopy (GC-MS) analysis of the ME and its solvent fractions identified 49 confirmed compounds. These compounds are likely potential contributors to the observed inhibition of microalgal growth. In conclusion, our findings suggest that solvent extracts from P. haitanensis possess substantial potential for the control of HABs, offering a promising avenue for further research and application in ecosystem management.

Ion fluxes Involved in the Adaptation of the Estuarine Diatom Coscinodiscus centralis Ehrenberg to Salinity Stress.

Although estuarine diatoms have a wide range of salt tolerance, they are often severely stressed by elevated salt concentrations. It remains poorly understood how estuarine diatoms maintain ionic homeostasis under high-salinity conditions. Using a scanning ion-selective electrode technique, this study determined the fluxes of H+, Na+, and K+ involved in the acclimatization of the estuarine diatom Coscinodiscus centralis Ehrenberg after an elevation in salinity from 15 psu to 35 psu. The C. centralis cells exhibited marked H+ effluxes after a transient treatment (TT, 30 min) and short-term treatment (ST, 24 h). However, a drastic shift of H+ efflux toward an influx was induced in the long-term treatment (LT, 10 days). The Na+ flux under TT, ST, and LT salinity conditions was found to accelerate the Na+ efflux. More pronounced effects were observed under the ST and LT salinity conditions compared to the TT salinity condition. The K+ influx showed a significant increase under the LT salinity condition. However, the salinity-induced Na+/H+ exchange in the estuarine diatom was inhibited by amiloride and sodium orthovanadate. These results indicate that the Na+ extrusion in salt-stressed cells is mainly the result of an active Na+/H+ antiport across the plasma membrane. The pattern of ion fluxes under the TT and ST salinity conditions were different from those under the LT salinity conditions, suggesting an incomplete regulation of the acclimation process in the estuarine diatom under short-term salinity stress.

Performance management algorithm of financial shared service center based on Internet of Things public cloud privacy protection.

The Internet of Things (IoT) refers to the use of various communication technologies to achieve the interconnection of everything in cyberspace, and to achieve smart home and intelligent transportation, thus generating unprecedented amounts of data. In the financial sharing center, all businesses can extract effective data from these massive databases for analysis, and use data analysis tools to collect business, financial, human, process, knowledge and social data. At present, various types of IT (Internet Technology) systems have been widely used in financial sharing centers. However, a large number of sensitive data have also been generated. In order to protect these sensitive data, there is a high requirement for the personal information of IT system operation and financial sharing center personnel. In order to protect user data privacy, the optimal and most effective use of IT systems is an important issue that must be considered in privacy management. At present, there are many algorithms to protect data and privacy, but the effect is not ideal. Considering the balance between privacy issues, this paper proposed a K-means clustering algorithm based on IoT public cloud privacy protection technology to analyze the performance management of financial sharing center. The research results showed that before the improvement, the average number of employees who were dissatisfied with the post training ability and information platform construction ability of the financial sharing center was 57.9 and 57.8% respectively, more than half of them. After the improvement of IoT based public cloud privacy protection, the average number of employees dissatisfied with the post training ability and information platform construction ability of the financial sharing center was 5 and 3.9%, far less than the data prior to the improvement. It showed that IoT public cloud privacy protection was conducive to the performance management of the financial sharing center, and the relationship between the two was positive.

Synthesis of CF3-Substituted Alkylamines, 1,2-Bisazoles, and 1,4,5,6-Tetrahydro-1,2,4-triazines from Newly Designed Tetrazole-Activated Trifluoromethyl Alkenes.

A new class of Michael acceptor, tetrazolyl-trifluoromethyl alkenes, has been discovered. They readily undergo Michael-type addition instead of addition-elimination reaction with aliphatic amines and azoles to furnish ß-trifluoromethyl alkylamines and CF3-substituted 1,2-bisazole derivatives, respectively. Additionally, some of the products are capable of engaging in microwave-assisted intramolecular denitrogenative annulation, leading to the formation of CF3-substituted 1,4,5,6-tetrahydro-1,2,4-triazines that are otherwise difficult to access by other methodologies.

N-Trifluoropropylation of Azoles through N-Vinylation and Sequential Hydrogenation.

Installing a fluoroalkyl group onto the nitrogen atom of azoles represents a potential strategy for lead optimization in medicinal chemistry. Herein, we describe a method for the N-trifluoropropylation of azoles. This process is accomplished using a combination of regioselective N-vinylation and sequential hydrogenation. The two-step sequence is applicable to a diverse set of azoles and tolerates a wide range of functionalities. In addition, we showcase its practicability and utility through the gram-scale synthesis and the late-stage modification of a complex molecule.

Rapid detection method of Skeletonema pseudocostatum and preparation of test strip.

In eutrophic waters, harmful algal blooms (HAB) are particularly prone to occur, which will affect the ecological environment and public health and safety. How to quickly detect and monitor marine microalgae is the key to preventing and managing HAB. Our innovative application of colloidal gold immunochromatography (GICG) technology to detect the dominant species in red tide, Skeletonema pseudocostatum, to monitor the outbreak of red tide. The experimental results show that the method and the prepared test strips are extremely sensitive and can specifically detect the presence of Skeletonema pseudocostatum. The approximate concentration of algae cells is judged by establishing a fitting relationship between the degree of color development and the concentration of algae cells. This test strip provides a quick and easy method for routine environmental monitoring, fishery water quality monitoring, and field testing of red tide monitoring. It effectively warns of the outbreak of red tides and also provides a new application direction for GICG technology.

A new marine epipsammic diatom species, Ambodajingensis sp. nov. (Bacillariophyceae), from the coast of Southeast China.

Ambodajingensis HH Liu, Z Wang, YH Gao & CP Chen, sp. nov. is described as a new species in samples collected from sand grains at Dajing Beach, Ningde City, Fujian Province, China. Morphological details of the new species with respect to valve shape, size and valve ultrastructure are presented based on light microscopy (LM) and scanning electron microscopy (SEM). The main features of Ambodajingensis under a light microscope are elongated elliptic valves with rounded apices, two internal costae on the valve and rectangular in girdle views. SEM observation showed that externally, the frustules are comprised of two valves with a relatively deep mantle and a transition between the valve faces. Small, flabelliform spines are present along the valve margin. Internally, the valves are divided into three sectors by robust costae, which penetrate the whole valve lumen and are thickest at the mantle interior and thinner toward the center. The sternum is narrow and linear, visible only in the valve apex, set off by costae. The striae are comprised of small, round areolae and they are parallel in the middle to slightly radiate at the apices. The new species is compared with other species in the genus Ambo.

The effect of Ditylum brightwellii (Bacillariophyceae) on colony development of bloom forming species Phaeocystis globosa (Prymnesiophyceae) under nutrient-replete condition.

To improve our knowledge of the factors regulating Phaeocystis globosa colony formation, the effects of the diatom Ditylum brightwellii on P. globosa colony development were investigated using co-culture and cell-free filtrate approaches. The co-culture experiments showed the moderate abundance of D. brightwellii significantly increased the number and size of colonies, whereas a dramatically decreased effect from high abundance of D. brightwellii. The low abundance of D. brightwellii promoted early formation of P. globosa colony. The cell-free filtrate experiments indicated that culture-filtrates from the exponential phase of D. brightwellii were stimulatory for P. globosa colony formation with more and bigger colonies formed, whereas an inhibitory effect from its senescence phase filtrates. D. brightwellii may influence P. globosa colony formation by regulating the growth of P. globosa solitary cells. Our results suggest that D. brightwellii influences P. globosa colony development, but its effects vary according to its concentrations and growth phases.

Transient Receptor Potential Ankyrin 1 Mediates Hypoxic Responses in Mice.

Transient receptor potential ankyrin 1 (TRPA1) is a non-selective cation channel that is broadly expressed in sensory pathways, such as the trigeminal and vagus nerves. It is capable of detecting various irritants in inspired gasses and is activated during hypoxia. In this study, the role of TRPA1 in hypoxia-induced behavioral, respiratory, and cardiovascular responses was examined through four lines of experiments using TRPA1 knockout (KO) mice and wild type (WT) littermates. First, KO mice showed significantly attenuated avoidance behavior in response to a low (15%) oxygen environment. Second, the wake-up response to a hypoxic ramp (from 21 to 10% O2 in 40 s) was measured using EEG electrodes. WT mice woke up within 30 s when oxygen was at 13-14%, but KO mice did not wake up until oxygen levels reached 10%. Histological analysis confirmed that mild (13% O2) hypoxia resulted in an attenuation of trigeminal neuronal activation in KO mice. Third, the ventilatory response to hypoxia was measured with whole body plethysmography. KO mice showed attenuated responses to mild hypoxia (15% O2) but not severe hypoxia (10% O2). Similar responses were observed in WT mice treated with the TRPA1 blocker, AP-18. These data clearly show that TRPA1 is necessary for multiple mild hypoxia (13-15% O2)-induced physiological responses. We propose that TRPA1 channels in the sensory pathways innervating the airway can detect hypoxic environments and prevent systemic and/or cellular hypoxia from occurring.

Evaluation of electrode-sample contact impedance under different curing humidity conditions during measurement of AC impedance of cement-based materials.

In this study, a simple method was proposed to calculate electrode-sample contact impedance in the cases of two-point and four-point measurements. The results indicated that when using the saturated calcium hydroxide solution (SCH) as conductive medium, the contact impedance in the four-point measurement is negligible for the impedance range of cement-based materials. The SCH can be used as a reference for correction of the contact impedance. A reasonable combination of curing humidity and different conductive media is recommended for the two-point measurement, which is suitable for testing the ACIS of cement-based materials. In a case of contact impedance not being precisely known, it is highly recommended that a four-point measurement with two different ratios of the length of the sample and the center spacing of the voltage electrodes (L/a) should be conducted to evaluate the effect of the contact impedance following the procedure proposed in this study.

Allelopathic inhibitory effect of the macroalga Pyropia haitanensis (Rhodophyta) on harmful bloom-forming Pseudo-nitzschia species.

The blooms of harmful microalgae represent a prominent threat to fisheries, public health, and economies throughout the world. Recent studies have shown that certain macroalgae release allelochemicals that can inhibit the growth of bloom-forming microalgae. In this study, we found that the macroalga Pyropia haitanensis significantly inhibited growth of the harmful bloom-forming microalgae Pseudo-nitzschia pungens and Pseudo-nitzschia multiseries. The inhibitory-effect of the live thali of P. haitanensis was highest, followed by that of dry powder, water-soluble extract, and culture medium filtrate. The Pseudo-nitzschia species died 96 h after exposure to 5-10 g fresh-weight L-1 of P. haitanensis live thalli. Furthermore, an aqueous extract of P. haitanensis suppressed the growth of P. pungens and P. multiseries, thereby indicating that P. haitanensis contains stable allelopathic substances that cause the observed inhibitory-effects. On the basis of these findings, we conclude that the macroalga P. haitanensis would have potential utility in controlling the blooms of Pseudo-nitzschia species.

Using a mixture of wastewater and seawater as the growth medium for wastewater treatment and lipid production by the marine diatom Phaeodactylum tricornutum.

This study was conducted to evaluate the potential of the marine diatom Phaeodactylum tricornutum in nutrient removal coupled with biodiesel production using different ratios of mixed municipal wastewater (MW) and seawater (SW) as the growth medium. The results indicated that P. tricornutum exhibited high nutrient removal efficiency with the ratios of MW: SW = 1:1 and MW: SW = 2:1, e.g. 87.7-89.9% for chemical oxygen demand (COD), 82.2-86.7% for total nitrogen (TN), 96.0-97.0% for total phosphorus, and 76.9-84.2% for ammonium (NH3-N). Significantly higher biomass and lipid productivity were obtained with aeration. The highest lipid productivity of P. tricornutum was 54.76 mg/L/day, which was obtained with a two-step cultivation using the ratio of MW: SW = 1:1 by diluting half of the mixture and bubbling with 5% CO2 during the second step. These results suggested that the marine diatom P. tricornutum exhibited great potential for using mixed wastewater for wastewater treatment and biodiesel production.

Effects of fundamental nutrient stresses on the lipid accumulation profiles in two diatom species Thalassiosira weissflogii and Chaetoceros muelleri.

Microalgae are considered as attractive feedstocks for biofuel production nowadays because of their high lipid contents and easy cultivation. In the present study, two diatoms, Thalassiosira weissflogii and Chaetoceros muelleri, were cultured under various nutrient-limitation conditions to explore their comprehensive lipid accumulation profiles for further commercialization. In T. weissflogii, the highest neutral lipid accumulation and highest lipid productivity (14.28 mg L-1 day-1) were both recorded under P-limitation. In C. muelleri, the highest lipid content (35.03% of dry cell weight), highest neutral lipid accumulation, and highest lipid productivity (29.07 mg L-1 day-1) were all recorded under N-limitation. Besides, the predominant fatty acids of T. weissflogii and C. muelleri were myristic acid (C14:0), palmitic acid (C16:0), and palmitoleic acid (C16:1), with the amounts of 58.4-74.4 and 74.1-87.7% of the total fatty acids, respectively. Moreover, nutrient limitations led to a lower proportion of polyunsaturated fatty acids (PUFA) than that of saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) in both species. The ratios of (SFA + MUFA) to PUFA were from 1.65 to 3.01 in T. weissflogii, and up to 3.61 to 8.59 in C. muelleri. Our results suggested the feasibility of C. muelleri as biodiesel feedstock due to its more suitable fatty acid composition and higher lipid productivity compared to T. weissflogii.

Differential cellular responses associated with oxidative stress and cell fate decision under nitrate and phosphate limitations in Thalassiosira pseudonana: Comparative proteomics.

Diatoms are important components of marine ecosystems and contribute greatly to the world's primary production. Despite their important roles in ecosystems, the molecular basis of how diatoms cope with oxidative stress caused by nutrient fluctuations remains largely unknown. Here, an isobaric tags for relative and absolute quantitation (iTRAQ) proteomic method was coupled with a series of physiological and biochemical techniques to explore oxidative stress- and cell fate decision-related cellular and metabolic responses of the diatom Thalassiosira pseudonana to nitrate (N) and inorganic phosphate (P) stresses. A total of 1151 proteins were detected; 122 and 56 were significantly differentially expressed from control under N- and P-limited conditions, respectively. In N-limited cells, responsive proteins were related to reactive oxygen species (ROS) accumulation, oxidative stress responses and cell death, corresponding to a significant decrease in photosynthetic efficiency, marked intracellular ROS accumulation, and caspase-mediated programmed cell death activation. None of these responses were identified in P-limited cells; however, a significant up-regulation of alkaline phosphatase proteins was observed, which could be the major contributor for P-limited cells to cope with ambient P deficiency. These findings demonstrate that fundamentally different metabolic responses and cellular regulations are employed by the diatom in response to different nutrient stresses and to keep the cells viable.

Millstone: software for multiplex microbial genome analysis and engineering.

Inexpensive DNA sequencing and advances in genome editing have made computational analysis a major rate-limiting step in adaptive laboratory evolution and microbial genome engineering. We describe Millstone, a web-based platform that automates genotype comparison and visualization for projects with up to hundreds of genomic samples. To enable iterative genome engineering, Millstone allows users to design oligonucleotide libraries and create successive versions of reference genomes. Millstone is open source and easily deployable to a cloud platform, local cluster, or desktop, making it a scalable solution for any lab.

Seasonal variations of phytoplankton assemblages and its relation to environmental variables in a scallop culture sea area of Bohai Bay, China.

Seasonal variations of phytoplankton assemblages were examined in a scallop culture sea area of Bohai Bay (China) with regard to some major physical and chemical variables. Samples were collected at three stations from July 2011 to September 2013. A total of 134 species belong to 4 phyla were identified, of which 104 were diatoms, 27 were dinoflagellates, 1 was euglenophyte and 2 were chrysophytes. The cells abundance in autumn (55.44×103cells/L) was higher than that in summer (6.99×103cells/L), spring (3.46×103cells/L) and winter (2.69×103cells/L). The Shannon-Wiener diversity index was higher in summer (3.06), followed by spring (3.02) and winter (2.91), and low in autumn (1.40). Results of canonical correspondence analysis showed that phosphate, salinity, temperature, silicate and DIN/SiO2 ratio were the most important environmental factors influencing the variation of phytoplankton community structure. It is suggested that eutrophication resulted from scallop culture would cause a potential red tide risk.

Nasal TRPA1 mediates irritant-induced bradypnea in mice.

Transient receptor potential ankyrin 1 (TRPA1), a member of the TRP superfamily, exists in sensory neurons such as trigeminal neurons innervating the nasal cavity and vagal neurons innervating the trachea and the lung. Although TRPA1 has been proposed as an irritant receptor that, when stimulated, triggers bradypnea, precise locations of the receptors responsible have not been elucidated. Here, we examined the relative importance of TRPA1 located in the upper airway (nasal) and the lower airway (trachea/lungs) in urethane-anesthetized mice. To stimulate the upper and lower airways separately, two cannulas were inserted through a hole made in the trachea just caudal to the thyroid cartilage, one into the nasal cavity and the second into the lower trachea. A vapor of one of the TRPA1-agonists, allyl isothiocyanate (AITC), was introduced by placing a piece of cotton paper soaked with AITC solution into the airline. AITC decreased the respiratory frequency when applied to the upper airway (ca -30%) but not to the lower airway (ca -5%). No response was observed in TRPA1 knockout mice. Contribution of the olfactory nerve seemed minimal because olfactory bulbectomized wild-type mice showed a similar response to that of the intact mice. AITC-induced bradypnea seemed to be mediated, at least in part, by the trigeminal nerve because trigeminal ganglion neurons were activated by AITC as revealed by an increase in the phosphorylated form of extracellular signal-regulated kinase in the neurons. These data clearly show that trigeminal TRPA1 in the nasal cavity play an essential role in irritant-induced bradypnea.

Facile sand enhanced electro-flocculation for cost-efficient harvesting of Dunaliella salina.

Energy consumption and water resource in the cultivation and harvesting steps still need to be minimized for the popularization of the microalgae-based products. An efficient electro-flocculation method for harvesting Dunaliella Salina integrated with local sand has been successfully applied. Sand was effective for speeding up the processes of flocculation and sedimentation of algal flocs and the electrolytic hydroxides was essential to bridge the sand and small flocs into large dense flocs. The maximal recovery effective improved from 95.13% in 6min to 98.09% in 4.5min and the optimal electrical energy consumption decreased 51.03% compared to conventional electro-flocculation in a laboratory ambient condition. Furthermore, reusing the flocculated medium in cultivation of the D. Salina with nitrogen supplemented performed no worse than using fresh medium. This sand enhanced electro-flocculation (SEF) technology provides a great potential for saving time and energy associated with improving microalgae harvesting.