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Summary: Multicellular magnetotactic prokaryotes (MMPs) exhibit peculiar coordination of swimming along geomagnetic field lines. Approximately 40–80 cells assemble, with a helical geometry or axisymmetry, into spherical or ellipsoidal MMPs respectively. To contribute to a comprehensive understanding of bacterial multicellularity here we took multiple microscopic approaches to study the diversity, assembly, reproduction and motility of ellipsoidal MMPs. Using correlative fluorescence in situ hybridization and scanning electron microscopy analysis, we found an unexpected diversity in populations of ellipsoidal MMPs in the Mediterranean Sea. The high‐pressure freezing/freeze substitution fixation technique allowed us to show, for the first time, that cells adhere via juxtaposed membranes and are held together by a rimming lattice. Fluorescence confocal microscopy and ultrathin section images revealed not only the one‐layer hollow three‐dimensional architecture, but also periphery–core unilateral constriction of constituent cells and unidirectional binary fission of the ellipsoidal MMPs. This finding suggests the evolution toward MMPs multicellularity via the mechanism of incomplete separation of offspring. Remarkably, thousands of flagellar at the periphery surface of cells underpin the coordinated swimming of MMPs in response to mechanical, chemical, magnetic and optical stimuli, including a magnetotactic photokinesis behaviour. Together these results unveil the unique structure and function property of ellipsoidal MMPs. [ABSTRACT FROM AUTHOR]

Objective: To observe the effect of electroacupuncture (EA) preconditioning of "Quchi" (LI11) and "Xuehai" (SP10) on mast cell (MC) degranulation, and expressions of inositol triphosphate(IP3), reactive oxygen species (ROS), transient receptor potential (TRP) M2, calmodulin (CaM) in rats with urticaria, so as to reveal its molecular mechanism under-lying improving urticaria., Methods: Thirty-two male SD rats were randomly divided into blank control, model, preconditioning of EA (Pre-EA) and medication groups ( n =8 rats/group). The urticaria model was established by intradermal injection of dilute allogeneic antioalbumin serum at the spots of the bilateral symmetry of the spine on the back, and followed by tail venous injection of mixture solution of egg albumin diluent, plus 0.5% Evans blue and normal saline. Ten days before the end of modeling, rats of the pre-EA group received EA stimulation of LI11 and SP10 for 20 min, once a day for 10 consecutive days, and those of the medication group received gavage of loratadine tablets diluted solution (1 mg/kg) once a day for 10 days. The times of rat's scratching the sensitized skin were recorded, the diameter of the sensitized blue spots was measured and the degranulation rate of skin MCs was counted under microscope after toluidine blue staining. The expression levels of IP3, ROS, TRPM2 and CaM in the skin tissue were measured by immunohistochemistry and western blot, respectively., Results: Compared with the blank control group, the scratching times, diameter of the sensitized blue spots, degranulation rate of MCs, and the expression levels of ion channel related proteins (IP3, ROS, TRPM2 and CaM) were significantly increased ( P <0.01) in the model group. In comparison with the model group, the scratching times, diameter of sensitized blue spot, degranulation rate of MCs, and the expression levels of IP3, ROS, TRPM2 and CaM in both pre-EA and medication groups were significantly down-regulated ( P <0.01, P <0.05). No significant differences were found between Pre-EA and medication groups in down-regulating the levels of the above-mentioned 7 indexes., Conclusion: EA-LI11 and SP10 preconditioning can reduce the cutaneous anaphylaxis in urticaria rats, which may be related to its effects in inhibiting the degranulation of MCs, and the expression of TRP channel related proteins.

Objective: To observe the effect of electroacupuncture (EA) preconditioning on the expressions of tyrosine kinase Lyn and spleen tyrosine kinase (Syk) in mast cells of subcutaneous loose connective tissue in the rats with urticaria and explore the potential biological mechanism of EA in the intervention of urticaria., Methods: A total of 32 SD rats were randomized into a blank group, a model group, an EA group and a positive medication group, 8 rats in each one. Except of the blank group, the passive cutaneous anaphylaxis (PCA) was adopted to prepare the model of urticaria in the rats of the rest three groups. In the EA group, EA was applied to bilateral "Quchi" (LI 11), "Xuehai" (SP 10) and "Zusanli" (ST 36), with disperse-dense wave, 2 Hz/15 Hz in frequency and 1 mA in current intensity, once daily, for 20 min each time, consecutively for 7 days. In the positive medication group, loratadine (1 mg•kg -1 •d -1 ) was for intragastric administration, once daily, consecutively for 7 days. The samples were collected for index detection 30 min after PCA antigen challenge in the rats of each group. Spectrophotometer was adopted to determine the effusion quantity of Evans blue in the allergized site of skin. HE staining was used to observe the morphological changes in the allergized site of skin. Toluidine blue staining was provided to observe mast cell degranulation in subcutaneous loose connective tissue in the allergized site of skin. Immunohistochemistry was applied to determine the protein expressions of Lyn and Syk during degranulation of mast cells., Results: In the rats of the odel group, the eipdermis of allergized site was thickening, cells were disorganized in hierarchy and inflammatory cells were infiltrated largely in the dermis. In the positive medication group and the EA group, the epidermis was getting thin, cell arrangement was clear and the inflammatory cell infiltration was obviously alleviated as compared with the model group. Compared with the blank group, the OD value of skin dye effusion quantity, the degranulation rate of mast cells and the positive expressions of Lyn and Syk were all increased in the model group ( P <0.01). Compared with the model group, the OD value of skin dye effusion quantity, the degranulation rate of mast cells and the positive expressions of Lyn and Syk were all reduced in the EA group and the positive medication group ( P <0.01). Compared with the positive medication group, the degranulation rate of mast cells was increased significantly in the EA group ( P <0.01)., Conclusion: Electroacupuncture at "Quchi" (LI 11), "Xuehai" (SP 10) and "Zusanli" (ST 36) reduces vascular permeability and gives play to the role of anti-allergy by the way of regulating and controlling the degranulation of mast cells in the rats with urticaria and the effect mechanism of electroacupuncture may be related to the inhibition of protein expressions of Lyn and Syk in mast cells.

Objective: To observe the effect of different frequencies (2 Hz, 100 Hz) of electroacupuncture (EA) on limb locomotion and the expression of inflammatory factors IL-1β, IL-6, TNF-α in sciatic nerve, and nuclear factor kappa B (NF-κB) in lumber(L)4-L5of spinal cord in rats with sciatic nerve injury (SNI), so as to reveal its mechanisms underlying improvement of SNI., Methods: A total of 48 SD rats (half male and half female) were equally divided into blank control, model, low frequency (2 Hz) EA and high frequency (100 Hz) EA groups. The SNI model was established by clamping the spinal nerve. EA intervention (2 Hz, 100 Hz, 1 mA), starting on the 8 th day after modeling, was applied to "Huantiao" (GB30) on the injured side for 15 min, once daily for 14 consecutive days. The sciatic function index (SFI) was calculated to assess the injured hindlimb recovery with reference to BAIN's and colleagues' methods. Histopathological changes of the sciatic nerve were displayed by H.E. staining. The expressions of IL-1β, IL-6 and TNF-α in the sciatic nerve tissue were detected by immunohistochemistry, and the expression of NF-κB in the spinal cord was detected by using Western blot., Results: After modeling, the SFI level on day 8 was significantly decreased in the model group ( P <0.01), and no significant differences were found among the model, low frequency EA and high frequency EA groups before the EA intervention ( P >0.05). Following the treatment (at the 22 nd day), the SFI values of both low frequency EA and high frequency EA groups were significantly increased ( P <0.01), suggesting an improvement of the limb motor function, and the SFI of the low frequency EA group was notably higher than that of the high frequency EA group ( P <0.01). In comparison with the blank control group, the expression levels of IL-1β, IL-6, TNF-α in the sciatic nerve and NF-κB protein in the spinal cord were significantly up-regulated ( P <0.05). Following EA intervention, the increased expression levels of IL-1β, IL-6, TNF-α and NF-κB proteins were significantly down-regulated in both low frequency EA and high frequency EA groups ( P <0.05), and the therapeutic effect of low frequency EA was markedly superior to that of high frequency EA in down-regulating the expression levels of IL-1β, IL-6, TNF-α and NF-κB protein ( P <0.05). H.E. staining showed increase of Schwann cells in number, cellular swelling, and disintegration of the axons and myelin sheath, and appearance of vacuolar degeneration in the model group, which was relatively milder in both low frequency EA and high frequency EA groups, particularly in the low frequency EA group., Conclusion: EA of GB30 at 2 Hz and 100 Hz can promote the recovery of hindlimb motor function in SNI rats, which is probably related to its function in inhibiting the inflammatory response, and facilitating the repair of the damaged sciatic nerve. 2 Hz EA is better than 100 Hz EA in the therapeutic effect.

Soil P fraction, microbial biomass P (MBP), and activities of acid phosphomonoesterase (ACP) and phosphodiesterase (PD) were analyzed under evergreen broad-leaved forest, mixed forest and coniferous forest in Daiyun Mountains. The results showed that labile-P comprised only 1.0%-4.5% of soil total phosphorus (TP). The ratio of soil carbon to organic phosphorus (C:Po) was >200, indicating phosphorus limitation across the three vegetation types. Organic phosphorus (Po) was a significant fraction of soil P, which accounted for 44.8%-47.1% and 28.6%-30.6% of TP in A and B horizons, respectively. Results from the redundancy analysis showed that the changes in P fractions were mainly driven by PD in the A horizon and by ACP in the B horizon. Moreover, the activities of PD and ACP had a significant negative correlation with Po. The results suggested that phosphorus deficiency occurred in the three vegetation types, and that PD and ACP could play major roles in the depletion of soil Po in response to phosphorus limitation in subtropical forests.

Magnetotactic multicellular prokaryotes (MMPs) consist of unique microorganisms formed by genetically identical Gram-negative bacterial that live as a single individual capable of producing magnetic nano-particles called magnetosomes. Two distinct morphotypes of MMPs are known: spherical MMPs (sMMPs) and ellipsoidal MMPs (eMMPs). sMMPs have been extensively characterized, but less information exists for eMMPs. Here, we report the ultrastructure and organization as well as gene clusters responsible for magnetosome and flagella biosynthesis in the magnetite magnetosome producer eMMP Candidatus Magnetananas rongchenensis. Transmission electron microscopy and focused ion beam scanning electron microscopy (FIB-SEM) 3D reconstruction reveal that cells with a conspicuous core-periphery polarity were organized around a central space. Magnetosomes were organized in multiple chains aligned along the periphery of each cell. In the partially sequenced genome, magnetite-related mamAB gene and mad gene clusters were identified. Two cell morphologies were detected: irregular elliptical conical 'frustum-like' (IECF) cells and H-shaped cells. IECF cells merge to form H-shaped cells indicating a more complex structure and possibly a distinct evolutionary position of eMMPs when compared with sMMPs considering multicellularity., (© 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.)

A continuous measurement was conducted in urban area of Shanghai from 1stSeptember to 21st November, 2011. The mass concentration of PM2.5 and the mixing ratio of VOCs were obtained during the period. Four pollution episodes were observed: PD1 (20th-23th September), PD2 (5th-9th October), PD3 (13rd - 18th October), PD4 (10th - 14th November). The average mass concentrations of PM2.5 were (45+/-16), (76+/-46), (57+/-36) and (122+/-92) microg.m-3, respectively. The mixing ratio of VOCs were (30.87+/-30.77) x10(-9), (32.09+/-30.69) x10(-)9, (34.04+/-28.13) x10(-9) and (44.27+/-31.58) x10(-9). Alkane, alkene and aromatic hydrocarbons accounted for 53. 58% , 27. 89% , and 10. 96% of the total VOCs, respectively. The OH radical loss rate (LOH) and the ozone formation potential (OFP) were applied to assess the chemical reactivity of VOCs, the results showed that the alkenes and aromatics were the most important contributors to LOH and OFP in the atmosphere in the urban area of Shanghai, in autumn. Fractional aerosol coefficients (FAC) and the ratio of organic carbon to element carbon (OC/EC) were used to estimate the potential formation of secondary organic aerosols (SOA) in Shanghai, the SOA concentration values obtained by the two methods were 1.43 microg.m-3 and 4.54 microg.m-3, respectively. The value predicted by OC/EC was significantly higher, which was mainly due to the low amount of SOA precursors measured in this study. The aromatics were not only the most important contributors to OFP, but also important SOA precursors. By applying the positive matrix factorization (PMF) model, six major sources were extracted to identify the sources of VOCs in autumn in Shanghai, including vehicle exhaust (24.30%), incomplete combustion (17.39%), fuel evaporation (16.01%) , LPG/NG leakage (15.21%) , petrochemical industry (14.00% ), and paint/solvent usage (13.09%). Vehicle exhaust and paint/solvent usage contain abundant aromatics species which are the most important contributors to OFP and important SOA precursors. The above two sources contributed 37.39% of the total VOCs concentration. Hence, these sources should be listed as priority of air pollution control strategy for Shanghai in future.

The emission strength of VOCs was estimated in the study, based on the volatile organic compounds (VOCs) measurement results. Air mass backward trajectories were computed and cluster analysis was done combining with the corresponding air pollution indexes and VOCs concentrations. Source apportionment of VOCs was studied using receptor model. According to this study, VOCs emission in Shanghai per hour resulted in the VOCs concentration increment of (5.98 +/- 3.18) x 10(-9) during 2010 EXPO (from 1st May to 31st October in 2010), which was decreased by about 1 x 10(-9) compared to that in the same period of 2009. Under the control of the air masses roughly from the east (40%), the API was lower than 50. Influenced by the air masses from the northwest, the air quality was the worst with the average API higher than 70. The air masses from the southwest also resulted in bad air quality, with API higher than 60. The air masses originated from the west accounted for 25%, followed by the south and north air mass (20%). The VOCs concentrations were positively related to API in the same air mass, R2 = 0.599. During the 2010 EXPO, the emission related to vehicles including exhaust and gasoline evaporation contributed the largest amount of VOCs, approximately about -40%, followed by industry including industrial processes and coal combustion (30% - 40%), and solvent use and painting (20%). The biogenic emission was also considerable and accounted for 6% of VOCs in summer.

Light-duty gasoline taxis (LDGT) and passenger cars (LDGV), heavy-duty diesel buses (HDDB) and trucks (HDDT), gasoline motorcycles (MC) and LPG scooters (LPGS), were selected for tailpipe volatile organic compounds (VOCs) samplings by using transient dynamometer and on road test combined with SUMMA canisters technology. The samples were tested by GC-MS to analyze the concentration and species composition of VOCs. The results indicate that light-duty gasoline automobiles have higher fractions of aromatic hydrocarbons, which account for 43.38%-44.45% of the total VOCs, the main aromatic hydrocarbons are toluene and xylenes. Heavy-duty diesel vehicles have higher fractions of alkanes, which constitute 46.86%-48.57% of the total VOCs, the main alkanes are propane, n-dodecane and n-undecane. In addition, oxy-organics account for 13.28%-15.01% of the VOCs, the main oxy-organics is acetone. The major compound from MC and LPGS exhaust is acetylene, it accounts for 39.75% and 76.67% of the total VOCs, respectively. VOCs exhaust from gasoline motorcycles and light-duty gasoline automobiles has a significantly higher chemical reactivity than those from heavy-duty diesel vehicles, which contribute 55% and 44% to the atmospheric chemical reactivity in Shanghai. The gasoline motorcycles and light-duty gasoline automobiles are the key pollution sources affecting city and region ambient oxidation, and the key active species of toluene, xylenes, propylene, and styrene make the greatest contribution.