Removal of tetracycline from water by catalytic photodegradation combined with the microalga Scenedesmus obliquus and the responses of algal photosynthesis and transcription.

The antibiotic tetracycline (TC) and its degradation products (TDPs) in degradation solution present serious environmental problems, such as human health damage and ecological risk; thus further treatment is required before being released into the aquatic environment. Furthermore, their environmental impact on microalgae remains unclear. In this study, TC was degraded by photocatalysis using birnessite and UV irradiation, followed by biological purification using the microalga Scenedesmus obliquus. In addition, the photosynthetic activity and transcription of the microalgae were examined to evaluate the toxicity of TC and TDPs. The results show that photocatalytic degradation efficiency reached 92.7% after 30 min, and 11 intermediate products were detected. The microalgae achieved a high TC removal efficiency (99.7%) after 8 days. Exposure to the degraded TC solution (D) resulted in significantly lower (p < 0.05) biomass than the pure TC (T), and S. obliquus in the T treatment showed better resilience than the D treatment. Transcriptomic assays for different treatments revealed differential gene expression mainly involving the photosynthesis, ribosome, translation and peptide metabolic progresses. The up-regulation of photosynthesis-related genes and differential expression of chloroplast genes may be important for S. obliquus to acquire high photosynthetic efficiency and growth recovery when exposed to TC and TDPs. Our study provides a reference for TC removal using a combination of catalytic degradation and microalgal purification, and it is also helpful for understanding the environmental risk of TDPs in natural aquatic environments.

The Preparation of Golgi Apparatus-Targeted Polymer Dots Encapsulated with Carbon Nanodots of Bright Near-Infrared Fluorescence for Long-Term Bioimaging.

As a vital organelle in eukaryotic cells, the Golgi apparatus is responsible for processing and transporting proteins in cells. Precisely monitoring the status of the Golgi apparatus with targeted fluorescence imaging technology is of enormous importance but remains a dramatically challenging task. In this study, we demonstrate the construction of the first Golgi apparatus-targeted near-infrared (NIR) fluorescent nanoprobe, termed Golgi-Pdots. As a starting point of our investigation, hydrophobic carbon nanodots (CNDs) with bright NIR fluorescence at 674 nm (fluorescence quantum yield: 12.18%), a narrow emission band of 23 nm, and excellent stability were easily prepared from Magnolia Denudata flowers using an ultrasonic method. Incorporating the CNDs into a polymer matrix modified with Golgi-targeting molecules allowed for the production of the water-soluble Golgi-Pdots, which showed high colloidal stability and similar optical properties compared with pristine CNDs. Further studies revealed that the Golgi-Pdots showed good biocompatibility and Golgi apparatus-targeting capability. Based on these fascinating merits, utilizing Golgi-Pdots for the long-term tracking of the Golgi apparatus inside live cells was immensely successful.

Metabolomics revealed the photosynthetic performance and metabolomic characteristics of Euglena gracilis under autotrophic and mixotrophic conditions.

Photosynthetic and metabolomic performance of Euglena gracilis was examined and compared under autotrophic and mixotrophic conditions. Autotrophic protozoa (AP) obtained greater biomass (about 33% higher) than the mixotrophic protozoa (MP) after 12 days of growth. AP maintained steady photosynthesis, while MP showed a remarkable decrease in photosynthetic efficiency and dropped to an extremely low level at day 12. In MP, low light absorption and photosynthetic electron transport efficiency, and high energy dissipation were reflected by the chlorophyll (chl a) fluorescence (OJIP) of the protozoa. The values of ΨO, ΦEo, and ETO/RC of MP decreased to extremely low levels, to 1/15, 1/46, and 1/9 those of AP, respectively, while DIO/RC increased to approximately 16 times that of AP. A total of 137 metabolites were showed significant differences between AP and MP. AP accumulated more monosaccharide, lipids, and alkaloids, while MP produced more amino acids, peptides, and long-chain fatty acids including poly-unsaturated fatty acids. The top nine most important enriched pathways obtained from KEGG mapping were related to ABC transporters, biosynthesis of amino acids, purine metabolism, and carbohydrate metabolism. There were significant differences between AP and MP in photosynthetic activity, metabolites, and metabolic pathways. This work presented useful information for the production of high value bioproducts in E. gracilis cultured under different nutritional conditions.

Accelerating wavefront-sensing-based autofocusing using pixel reduction in spatial and frequency domains.

The wavefront-sensing-based autofocus method can precisely determine the focal plane only with few captured images; however, the required phase retrieval, numerical wavefront propagation, and in-focus determination are often time consuming, inevitably limiting its high-speed applications. To accelerate its processing speed, the pixel-reduced wavefront-sensing-based autofocus (PRWSA) method is proposed: with field of interest selection as pixel reduction in the spatial domain and image compression as pixel reduction in the frequency domain, the wavefront with fewer pixels can be used for autofocusing, significantly decreasing the processing time. With simulations, pixel reduction criteria in both the spatial and frequency domains are first determined and tested; next certificated by experiments, the PRWSA method is proved to be well implemented for different specimens. Considering it can precisely locate the focal plane with simple setup, and accelerate the processing speed, this PRWSA method can be a potential tool for high-speed autofocusing.

The Functional Mechanisms and Application of Electron Shuttles in Extracellular Electron Transfer.

Electron shuttles extensively exist in various environments. Some kinds of organic substances can be applied by microorganisms to produce electrons, and then the electrons can be transferred to other substances or microorganisms through electron shuttles, resulting in coexistence and interaction of diverse species of microbes. In this review, the functional mechanisms of extracellular electron transfer mediated by different electron shuttles are described. And different subtypes as well as the application of electron shuttles in microbial degradation of pollutants, microbial electricity, and the promotion of energy generation are also discussed. Summary results show that extracellular electron transfer is based on the electrogenesis microorganism with the structure of cytochromes or pili. Materials were usually used in long-distance electron transfer because of their widespread presence and abundance. Therefore, the review is beneficial to perceive the pathways of extracellular electron transfer mediated by electron shuttles and explore the contribution of different electron shuttles in extracellular electron transfer.

Subwavelength imaging by a nonlinear negative refraction lens through four wave mixing.

We propose a new approach for subwavelength imaging using a nonlinear negative refraction lens based on four wave mixing process. Here a thin metal film is implemented as the nonlinear negative refraction lens to bend the incident signal waves to negatively refracted FWM ones according to the partial phase matching along its surface. The imaging process can be described by the nonlinear optical transfer function over the entire spatial spectra including the evanescent ones. Analytical calculations and numerical simulations are performed to demonstrate the capability of such imaging. Compared with the existing techniques, our method works on non-resonant condition over a broad range of spectrum, therefore, it may open up a new avenue for super-resolution imaging applications.

Synthesis and antifungal activity of 2-allylphenol derivatives against fungal plant pathogens.

2-Allylphenol (2-AP) is an effective fungicide against a number of plant pathogens, which can be metabolized and bio-transformed to four chemical compounds by Rhizoctonia cerealis. To determine if its degradation affects antifungal activity, two major metabolites derived from 2-AP including 2-(2-hydroxypropyl) phenol and 2-(3-hydroxypropyl) phenol were synthesized. Inhibition of mycelial growth of several plant pathogens by the metabolites was evaluated, and structures of two metabolites were determined by hydrogen nuclear magnetic resonance (1H NMR). Among these metabolites, only 2-(2-hydroxypropyl) phenol inhibited test pathogens effectively. EC50 values of 2-(2-hydroxypropyl) phenol for inhibition of mycelial growth of R. cerealis, Pythium aphanidermatum, Valsa mali and Botrytis cinerea ranged from 1.0 to 23.5µg/ml, which were lower than the parental fungicide 2-AP that ranged from 8.2 to 48.8µg/ml. Hyphae of R. cerealis and P. aphanidermatum treated with 2-(2-hydroxypropyl) phenol were twisted. Newly developed hyphae were slender, twisted and swollen on the tip, while old hyphae were hollow and ruptured. This is the first report indicating the formation of 2-(2-hydroxypropyl) phenol may have contributed to toxicity of 2-allylphenol in control of plant pathogens.

Novosphingobium fluoreni sp. nov., isolated from rice seeds.

A yellow-pigmented, Gram-stain-negative, rod-shaped, non-spore-forming bacterium designated strain HLJ-RS18(T), which could degrade fluorene, was isolated from rice seeds collected from Heilongjiang Province, China. Similarities of full-length of 16S rRNA gene sequences between strain HJL-RS18(T) and the type strains of the genus Novosphingobium with validly published names ranged from 93.8 to 97.1%. Phylogenetic analysis with maximum-likelihood and neighbour-joining methods revealed that strain HLJ-RS18(T) belonged to genus Novosphingobium and strain HLJ-RS18(T) formed a distinct clade to Novosphingobium chloroacetimidivorans BUT-14(T) (96.9% similarity based on 16S rRNA gene). DNA-DNA hybridization of HLJ-RS18(T) and BUT-14(T) showed a low relatedness value of 22.4 ± 0.9%, which indicated that strain HLJ-RS18(T) represents a novel species of the genus Novosphingobium. The genomic DNA G+C content of strain HLJ-RS18(T) was 62 mol%. Ubiquinone Q-10 was the major respiratory quinone. Spermidine was the predominant polyamine. Polar lipids consisted mainly of aminophospholipid, phosphatidylglycerol, phosphatidylethanolamine, phospholipid and sphingoglycolipid. The predominant fatty acid composition of HLJ-RS18(T) were summed 8 (C(18:1)ω7c and/or C(18:1)ω6c, 61.5%), C(16 : 0) (14.2%), summed 3 (C(16:1)ω7c and/or C(16:1)ω6c, 13.5%) and C14:0 2-OH (6.8%). Phylogenetic analysis, DNA-DNA hybridization, chemotaxonomic data and phenotypic characteristics support the conclusion that HLJ-RS18(T) represents a novel species within the genus Novosphingobium. Therefore, we propose the species Novosphingobium fluoreni sp. nov. with HLJ-RS18(T) ( = DSM 27568(T) = ACCC19180(T)) as the type strain.

[Measuring Method of Cardiac Output and Its Progress].

As one of the important indexes for the diagnosis and treatment of cardiovascular diseases, cardiac output can reflect the state of cardiovascular system timely, and can play a guiding role in the treatment of related diseases. In recent years detection technology of cardiac output has caused great attention, especially minimally invasive and non-invasive methods. In this paper, the principle of non-invasive detection methods and their recent developments are described, and various detection methods are also analyzed.

[Commercial orange juice beverages detection by fluorescence spectroscopy combined with PCA-ED and PLSR methods].

In order to classify the orange juiice beverages effectively, the fluorescence character differences of two kinds of orange juice beverages including 100% orange juice and orange drink were analyzed and compared, principal component analysis combined with Euclidean distance was adopted to classify two kinds of orange juice beverages, and ideal classification results were obtained. Meanwhile, the orange juice content estimation model was established by using fluorescence spectroscopy combined with partial least squares regression method, and the correlation coefficient R, root mean square error of calibration RMSEC and root mean square error of prediction RMSEP were 0.997, 0.87% and 2.05%, respectively. The experimental results indicate that the calibration model offers comparatively accurate content estimation, which reflect the actual orange juice content in the commercial orange juice beverages. The exploration to classify orange juice beverages was carried out from two aspects of qualitative and quantitative analysis by employing fluorescence spectroscopy combined with chemometrics method, which can provide a new idea for the classification and adulteration detection of commercial orange juice beverages, and also can give certain reference basis for the quality control of orange juice raw material.

Revealing the elevation of Zn2+ in the brain of depressed mice by a ratiometric fluorescent probe with dual near-infrared emissions.

A mitochondria-targeted ratiometric fluorescent probe (Mito-Zn) was first designed and synthesized with dual emissions both located in the near-infrared region, for Zn2+ detection with high sensitivity and selectivity. By using the developed Mito-Zn, a high level of Zn2+ in the depressed mouse brain was discovered for the first time.

Multiple degradation pathways of phenanthrene by Stenotrophomonas maltophilia C6.

Stenotrophomonas maltophilia strain C6, capable of utilizing phenanthrene as a sole source of carbon and energy, was isolated from creosote-contaminated sites at Hilo, Hawaii. Twenty-two metabolites of phenanthrene, covering from dihydrodiol to protocatechuic acid, were isolated and characterized. Phenanthrene was degraded via an initial dioxygenation on 1,2-, 3,4-, and 9,10-C, where the 3,4-dioxygenation and subsequent metabolisms were most dominant. The metabolic pathways were further branched by ortho- and meta-cleavage of phenanthrenediols to produce 1-hydroxy-2-naphthoic acid, 2-hydroxy-1-naphthoic acid, and naphthalene-1,2-dicarboxylic acid. These intermediates were then transformed to naphthalene-1,2-diol. 1-Hydroxy-2-naphthoic acid was also degraded via a direct ring cleavage. Naphthalene-1,2-diol underwent primarily ortho-cleavage to produce trans-2-carboxycinnamic acid and then to form phthalic acid, 4,5-dihydroxyphthalic acid and protocatechuic acid. Accumulation of salicylic acid in prolonged incubation indicated that a limited extent of meta-cleavage of naphthalene-1, 2-diol also occurred. This is the first study of detailed phenanthrene metabolic pathways by Stenotrophomonas maltophilia.

[Applicability of the two-compartment coaxial cylindrical model for ambulatory measuring of cardiac output with spot-electrodes].

The principle of ambulatory cardiac output (CO) measuring technique is introduced in this paper. Experimental studies about the applicability of the two-compartment coaxial cylindrical model for ambulatory measurement of cardiac output with spot-electrodes have been carried out with using our newly-developed multi-channel impedance mapping system. The key factors using a spot-electrode array instead of a conventional band-electrode array for non-invasive CO) measurement are elaborated. The variations of the electric impedance pulsatile component (deltaZ waveform) and the two kinds of typical modes of deltaZ distributions measured by six electrodes on the midsternal (midian) line from the medial portion at the level of clavicle to the portion above the xiphisternum are discussed. The applicability of the two-compartment coaxial cylindrical model for ambulatory measurement of CO with spot-electrodes is analyzed. Synthesizing the deltaZ distributions and their typical changing models on the midsternal (midian) line during blood inflowing into aorta is the optimal positions of a pair of spot-electrodes for voltage pick-up at the level of clavicle for the upper electrode and the position at the level of nipple for the lower electrode when spot-electrode is being used to measure non-invasive CO.

Magnetic field-assisted fabrication of quasi-bilayered, multi-responsive and patternable actuators.

Quasi-bilayered actuators composed of Fe3O4-decorated graphene oxide and polyvinylidene fluoride have been fabricated in a magnetic field. The actuators could stably respond to multiple stimuli including infrared light, acetone vapour and a magnetic field. The actuator is also patternable because of the magnetism-induced spatial distribution of fillers in the matrix.

3,3,3',3'-Tetra-methyl-6,6'-bis-[(pyridin-4-yl)meth-oxy]-1,1'-spiro-biindane -monohydrate.

The asymmetric unit in the title compound, C(33)H(34)N(2)O(2)·H(2)O, consists of a V-shaped mol-ecule and a water mol-ecule to which it is hydrogen bonded. The angle between the mean planes of the two spiro-connected indane groups is 77.06 (5)°. The two five-membered rings of the indane groups have envelope conformations with the methyl-ene atoms adjacent to the spiro C atom forming the flaps. They have deviations from the mean plane of the other four atoms in the rings of 0.374 (4) and 0.362 (4) Å. In the crystal, molecules are linked to form inversion dimers via O-H⋯N hydrogen bonds involving the pyridine N atoms and the solvent water mol-ecule. The dimers are linked into a chain along the b axis by π-π stacking inter-actions between a pyridine ring and its centrosymmetrically related ring in an adjacent dimer. The centroid-centroid distance between the planes is 3.7756 (17) Å, the perpendicular distance is 3.4478 (11) Šand the offset is 1.539 Å.

[The study of spectral characteristics of several organophosphate pesticides].

Using Edinburgh FLS920P spectrometer, the authors obtained the UV-visible spectrum and fluorescence spectrum of parathion, metaphos and isocarbophos in their solution of methanol and ethanol respectively, and discussed their spectral characteristics and their mechanisms. Results show that they all have obvious absorption and fluorescence under the excitation of ultraviolet. The absorption peaks of parathion, metaphos and isocarbophos in their methanol and ethanol solution respectively are at 304 nm/298 nm, 304 nm/304 nm and 286 nm/286 nm. The peak wavelengths of fluorescence are at 404 nm/403 nm, 407 nm/ 402 nm and 423 nm/415 nm, fitting fluorescence characteristics of conjugated aromatic compounds that the peak will have red shift with the increasing solvent polarity. The results may contribute to the application of spectral technique in the distinction of pesticides and detection of residues of pesticides in the area of food security supervision.

[Development of a continuous blood pressure monitoring and recording system].

A small experimental system is constructed with working principle of continuous blood pressure monitoring based on the volume compensation method. The preliminary experimental results show that the system can collect blood pressure signals at the radial artery effectively. The digital PID algorithm can track the variation of blood pressure. And the accuracy of continuous blood pressure detecting achieve the level of same kind of product.

[Study on saltation of fluorescence excitation spectra of erythrosine].

The fluorescence excitation spectra and absorption spectra of six kinds of erythrosine solutions with concentrations of 10, 20, 30, 40, 50 and 60 microg x mL(-1) were experimentally measured. It was found that the fluorescence excitation peaks are both located at 530 nm significantly when the concentrations of erythrosine solutions are 10 and 20 microg x mL(-1). However, the linetype saltation of fluorescence excitation spectrum occurs as the concentration of erythrosine solution is above 30 microg x mL(-1). The valley is located at 530 nm and two new peaks appear at both flanks of the valley. Compared with fluorescence excitation spectra, the absorption spectra of erythrosine solutions are without saltation and the peaks are all located at 530 nm. According to calculations and a series of contrast experiments, it was demonstrated that the absorption characteristic of erythrosine and the spectral measurement mode conspire to cause the saltation of fluorescence excitation spectra. The results can provide guidance for further research on physical and chemical properties of erythrosine, and offer help and reference for study on saltation behavior in fluorescence excitation spectra and improvement in spectral measuring mode.

[Optimal electrode array for ambulatory measuring of cardiac output based on the electrical impedance method].

Principle of ambulatory cardiac output (CO) measuring technique is introduced in this paper. A lot of experimental studies of the current distribution on the thorax under the condition that the current injection electrodes were adhered to different positions were carried out by using a developed multi-channel impedance mapping system. The static impedance contour maps (Zo-map) and its pulsatile component contour maps (deltaZ-map) under different measuring conditions were analyzed, and the applicability of a two-compartment coaxial cylindrical model using a spot-electrode array instead of the conventional band-electrode array for ambulatory CO measurement, as well as the optimal spot-electrode array, were discussed. Based on the experimental results and the daily use of the ambulatory CO measuring technique, the optimal spot-electrode array meeting the condition of the two-compartment coaxial cylindrical model was determined as that a pair of spot-electrodes for current injection was located on the positions behind the ears and on the right lower abdomen, and a pair of spot-electrodes for voltage pick-up places on the medial portion at the level of clavicle and on the portion above the xiphisternum.

Synergetic enhancement of methane production and system resilience during anaerobic digestion of food waste in ammonia-tolerant anaerobic sludge system.

The anaerobic digestion (AD) of food waste (FW) was augmented with ammonia-tolerant anaerobic sludge (ATAS). Different inoculum substrate ratios (ISR) under an initial ammonia stress of 4220 mg N/L were investigated. Results showed that the average specific methane production (SMP) of FW in the ATAS system increased by 36% compared with that in un-acclimated anaerobic sludge. SMP with ISR of 1:2.5 increased by approximately 6 times. Volatile fatty acids (VFAs) accumulation and sharp pH decline were not detected. These results revealed the high performance of ATAS in simultaneously relieving ammonia and acid stress. This improvement was attributed to multiple factors. ATAS had high ammonia tolerance and ability in conversion of acetate into methane. The equilibrium of NH3/NH4+, CO2/H2CO3/HCO3-, and CxHyCOOH/CxHyCOO- could promote VFAs and ammonia ionization, reduce the levels of free VFAs and ammonia, neutralize pH, and thus enhance the system's buffering capacity to be less susceptible to fluctuations. These results demonstrated that employing ATAS in improving AD performance and resilience from acid and ammonia inhibition is feasible and effective.