ALBERT

Description: Microbial reduction of Fe(III) can be one of the major factors controlling methane production from anaerobic sedimentary environments, such as paddy soils and wetlands. Although secondary iron mineralization following Fe(III) reduction is a process that occurs naturally over time, it has not yet been considered in methanogenic systems. This study performed a long-term anaerobic incubation of a paddy soil and ferrihydrite-supplemented soil cultures to investigate methanogenesis during ferrihydrite biomineralization. The results revealed that the long-term effect of ferrihydrite on methanogenesis may be enhancement rather than suppression documented in previous studies. During initial microbial ferrihydrite reduction, methanogenesis was suppressed, however, the secondary minerals of magnetite formation was simultaneous with facilitated methanogenesis in terms of average methane production rate and acetate utilization rate. In the phase of magnetite formation, microbial community analysis revealed a strong stimulation of the bacterial Geobacter , Bacillus and Sedimentibacter , and the archaeal Methanosarcina in the ferrihydrite-supplemented cultures. Direct electric syntrophy between Geobacter and Methanosarcina via conductive magnetite is the plausible mechanism for methanogenesis acceleration along with magnetite formation. Our data suggested that a change in iron mineralogy might affect the conversion of anaerobic organic matter to methane, and might provide a fresh perspective on the mitigation of methane emissions from paddy soils by ferric iron fertilization.

Description: Gastric cancer remains one of the most prevalent and lethal malignancies in the world. Despite new advances in treatment and diagnosis, patients with advanced gastric cancer are still difficult to cure resulting in a high mortality rate and poor prognosis. Signal transducer and activator of transcription 3 (Stat3) is observed aberrant in multiple tumours, including gastric cancer. Stat3 overexpression was confirmed performing a vital role in tumorigenesis. In the present study, we constructed a pSi-Stat3 plasmid to silence Stat3 and investigated the effect of pSi-Stat3 on cell proliferation, apoptosis and cell cycle progression in gastric cancer cell line SGC-7901 and mice xenograft model. Downstream proteins of Stat3, including Cyclin-D1, Survivin and Bcl-2, were detected as well for the underlying mechanism exploration. It showed that pSi-Stat3 can effectively silence the expression of Stat3 and inhibits the growth of gastric tumour both in vitro and in vivo significantly via cell apoptosis and cell cycle shift induction. The findings suggest that Stat3 signal pathway might be a promising therapeutic target for tumour treatment, including gastric cancer. Copyright © 2015 John Wiley & Sons, Ltd.

Description: ABSTRACT Based on the high-resolution gridding data (CN05) from 2416 station observations, a grid dataset of temperature and precipitation extreme indices with the resolution of 0.5° × 0.5° for China region was developed using the approach recommended by the Expert Team on Climate Change Detection and Indices. This article comprehensively presents temporal and spatial changes of these indices for the time period 1961–2010. Results showed widespread significant changes in temperature extremes consistent with warming, for instance, decreases in cold extremes and increases in warm extremes over China. The warming in the coldest day and night is larger than the warmest day and night, respectively, which is concurrent with the coldest night larger than the coldest day and the warmest night larger than the warmest day. Changes in the number of the cold and warm nights are more remarkable than the cold and warm days. Changes in precipitation extremes are, in general, spatially more complex and exhibit a less widespread spatial coverage than the temperature indices, for instance, the patterns of annual total precipitation amount, average daily precipitation rate, and the proportion of heavy precipitation in total annual precipitation are similar with negative trends in a southwest–northeast belt from Southwest China to Northeast China while positive trends in eastern China and northwestern China. The consistency of changes in climate extremes from the CN05 with other datasets based on the stations and reanalyses is also analysed.

Description: Abstract We analyze quiet‐time data from the Gravity Field and Ocean Circulation Explorer (GOCE) satellite as it overpassed the Southern Andes at z ≃ 275km on 5 July 2010 at 23 UT. We extract the 20 largest traveling atmospheric disturbances (TADs) from the density perturbations and cross‐track winds using Fourier analysis. Using gravity wave (GW) dissipative theory that includes realistic molecular viscosity, we search parameter space to determine which hotspot TADs are GWs. This results in the identification of 17 GWs having horizontal wavelengths λH = 170 − 1850km, intrinsic periods τIr = 11 − 54min, intrinsic horizontal phase speeds cIH = 245 − 630m/s, and density perturbations .We unambiguously determine the propagation direction for 11 of these GWs, and find that most had large meridional components to their propagation directions. Using reverse ray‐tracing, we find that 10 of these GWs must have been created in the mesosphere or thermosphere. We show that mountain waves (MWs) were observed in the stratosphere earlier that day, and that these MWs saturated at z ∼ 70 − 75 km from convective instability. We suggest that these 10 GOCE hotspot GWs are likely tertiary (or higher‐order) GWs created from the dissipation of secondary GWs excited from the body forces created from MW breaking. We suggest that the other GW is likely a secondary or tertiary (or higher‐order) GW. This study strongly suggests that the hotspot GWs over the Southern Andes in the quiet‐time middle winter thermosphere can not be successfully modeled by conventional global circulation models where GWs are parameterized and launched in the troposphere.

Description: Abstract During 30 September to 9 October 2016, Hurricane Matthew traversed the Caribbean Sea to the east coast of the United States. During its period of greatest intensity, in the central Caribbean, Matthew excited a large number of concentric gravity waves (GWs or CGWs). In this paper, we report on hurricane‐generated CGWs observed in both the stratosphere and mesosphere from spaceborne satellites and in the ionosphere by ground Global Positioning System receivers. We found CGWs with horizontal wavelengths of ~200–300 km in the stratosphere (height of ~30–40 km) and in the airglow layer of the mesopause (height of ~85–90 km), and we found concentric traveling ionospheric disturbances (TIDs or CTIDs) with horizontal wavelengths of ~250–350 km in the ionosphere (height of ~100–400 km). The observed TIDs lasted for more than several hours on 1, 2, and 7 October 2016. We also briefly discuss the vertical and horizontal propagation of the Hurricane Matthew‐induced GWs and TIDs. This study shows that Hurricane Matthew induced significant dynamical coupling between the troposphere and the entire middle and upper atmosphere via GWs. It is the first comprehensive satellite analysis of gravity wave propagation generated by hurricane event from the troposphere through the stratosphere and mesosphere into the ionosphere.

Description: A two-dimensional nonlinear numerical model was used to simulate large winds (≥100 ms −1 ) and wind shears (≥40 ms −1  km −1 ) in the mesosphere and lower thermosphere (MLT) that are caused by the interaction between gravity waves (GWs) and migrating tidal background. By varying the wavelengths of GWs and the phases of diurnal and semidiurnal tides, sixty-four numerical experiments were performed. Our numerical experiments indicate that both migrating diurnal and semidiurnal tides strongly modulate the occurrence of GW breaking, and the resulted larger winds and wind shears. The simulated large winds and wind shears are in good agreement with those from the rocket sounding chemical release measurements. Moreover, the occurrence of large wind shears highly depends on the phases of migrating tides in local time, which is in agreement with the reported lidar observations. The local time dependence of large wind shears is mainly attributed to the filtering and/or hindering effects of diurnal and semidiurnal tidal winds on GWs. Our simulation reveals that the nonlinear interactions between GWs breaking and the migrating diurnal and semidiurnal tides may play an important role in driving the large winds and wind shears in the MLT region and their local time dependence.

Description: Abstract A mesospheric bore event was observed in the airglow layers of both OH and OI (557.7 nm) bands by two all‐sky airglow imagers in Lhasa (29.66°N, 90.98°E) on the Tibetan Plateau and the Day Night Band (DNB) of the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar‐orbiting Partnership (NPP) satellite on the night of 16–17 December 2014. Simultaneous temperature and OH intensity observations from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument onboard the TIMED satellite and wind measurement by a Doppler meteor radar were used to characterize the environment of the bore propagation. A large mesospheric inversion layer was identified from the temperature measured by the SABER instrument. The observed winds in the height range of the OH layer were almost orthogonal to the propagation direction of the mesospheric bore. Both hydraulic jump theory and observations showed that the duct initially shrank followed by an expansion. The duct mainly existed in the OH layer but was weak in the OI layer, as revealed by the double‐layer imaging and satellite observations. The horizontal wavelengths and observed phase speeds of the bore packet decreased as the duct shrank and increased as the duct expanded. The intensity amplitude of the bore packet decreased slowly and then decreased sharply after dissipation. With the variation of the depth of the duct, the bore may have leak out of the duct. The presented study advances the understanding of mesospheric bore evolution and how the ducted environment influences the propagation of the bore.

Description: A new Carboline alkaloid, Trifiline D ( 1 ) and a new degraded diterpenoid, Trigoxyphin X ( 4 ) were isolated from the roots and stems of Trigonostemon lii . Their structures were elucidated by extensive spectroscopic analyses including 1D- and 2D-NMR techniques. Compound 1 exhibited weak inhibitory activity against MCF-7, A-549, MGC-803 and COLO-205 with IC 50 values ranging from 27.4 to 35.4 μM. This article is protected by copyright. All rights reserved.

Description: Responses of the lower thermospheric temperature to the 9-day and 13.5-day oscillations of recurrent geomagnetic activity and solar EUV radiation have been investigated using neutral temperature data observed by the TIMED/SABER (Thermosphere Ionosphere Mesosphere Energetics and Dynamics/Sounding of the Atmosphere using Broadband Emission Radiometry) instrument and numerical experiments by the NCAR-TIME-GCM (National Center for Atmospheric Research-Thermosphere Ionosphere Mesosphere Electrodynamics-General Circulation Model). The TIMED/ SABER data analyzed were for the period from 2002 to 2007 during the declining phase of solar cycle 23. The observations show that zonal mean temperature in the lower thermosphere oscillated with periods of near 9 and 13.5 days in the height range of 100-120 km. These oscillations were more strongly correlated with the recurrent geomagnetic activity than with the solar EUV variability of the same periods. The 9-day and 13.5-day oscillations of lower thermospheric temperature had greater amplitudes at high latitudes than at low latitudes; they also had larger amplitudes at higher altitudes and the oscillations could penetrate down to ~105 km, depending on the strength of the recurrent geomagnetic activity for a particular time period. The data further show that the periodic responses of the lower thermospheric temperature to recurrent geomagnetic activity were different in the two hemispheres. In addition, numerical experiments have been carried out using the NCAR-TIME-GCM to investigate the causal relationship between the temperature oscillations, and geomagnetic activity and solar EUV variations of the same periods. Model simulations showed the same periodic oscillations as those seen in the observations when the real geomagnetic activity index, Kp, was used to drive the model. These numerical results show that recurrent geomagnetic activity is the main cause of the 9-day and 13.5-day variations in the lower thermosphere temperature and the contribution from solar EUV variations is minor. Furthermore, we also found that consecutive CME events could cause long- duration enhancements in the lower thermospheric temperature that strengthen the 9-day and 13.5-day signals, and this kind of phenomenon mostly occurred between 2002 and 2005 during the declining phase of solar cycle 23.

Description: Purpose The phenotypic modulation of vascular adventitial fibroblasts plays an important role in vascular remodeling. Evidence have shown that endothelial cells and adventitial fibroblasts interact under certain conditions. In this study, we investigated the influence of endothelial cells on the phenotypic modulation of adventitial fibroblasts. Methods Endothelial cells and adventitial fibroblasts from rat thoracic aorta were cultivated in a co-culture system and adventitial fibroblasts were induced with angiotensin II (Ang II). Collagen I and alpha smooth muscle actin (α-SMA) expression and migration of adventitial fibroblasts were analyzed. Results Ang II upregulated the expression of collagen I and α-SMA and the migration of adventitial fibroblasts. Adventitial fibroblasts-endothelial cells co-culturing attenuated the effects of Ang II. Homocysteine-treated endothelial cells, which are functionally impaired, were less inhibitory of the phenotypic modulation of adventitial fibroblasts. Supplementation of endothelial cells with L-arginine (L-Arg) or 8-bromoguanosine 3',5'-cyclic monophosphate (8-BrcGMP) enhanced the trends, while with L-NG-nitroarginine methyl ester (L-NAME) or 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) the opposite effect was observed. Conclusion Under the influence of Ang II, adventitial fibroblasts were prone to undergo phenotypic modulation, which was closely related to vascular remodeling. Our study showed that endothelial cells influenced fibroblast phenotypic transformation and such effect would be mediated through the nitric oxide (NO)/cGMP signaling pathway. This article is protected by copyright. All rights reserved