Self-Retracting Motion of Graphite Microflakes

We report the observation of a novel phenomenon, the self-retracting motion of graphite, in which tiny flakes of graphite, after being displaced to various suspended positions from islands of highly orientated pyrolytic graphite, retract back onto the islands under no external influences. Our repeated probing and observing such flakes of various sizes indicate the existence of a critical size of flakes, approximately 35 micrometer, above which the self-retracting motion does not occur under the operation. This helps to explain the fact that the self-retracting motion of graphite has not been reported, because samples of natural graphite are typical larger than this critical size. In fact, reports of this phenomenon have not been found in the literature for single crystals of any kinds. A model that includes the static and dynamic shear strengths, the van der Waals interaction force, and the edge dangling bond interaction effect, was used to explain the observed phenomenon. These findings may conduce to create nano-electromechanical systems with a wide range of mechanical operating frequency from mega to giga hertzs

Seasonal temperature response over the Indochina Peninsula to a worst-case high-emission forcing: a study with the regionally coupled model ROM

Changes of surface air temperature (SAT) over the Indochina Peninsula (ICP) under the Representative Concentration Pathway (RCP) 8.5 scenario are projected for wet and dry seasons in the short-term (2020–2049) and long-term (2070–2099) future of the twenty-first century. A first analysis on projections of the SAT by the state-of-the-art regionally coupled atmosphere-ocean model ROM, including exchanges of momentum, heat, and water fluxes between the atmosphere (Regional Model) and ocean (Max Planck Institute Ocean Model) models, shows the following results: (i) In both seasons, the highest SAT occurs over the southern coastal area while the lowest over the northern mountains. The highest warming magnitudes are located in the northwestern part of the ICP. The regionally averaged SAT over the ICP increases by 2.61 °C in the wet season from short- to long-term future, which is slightly faster than that of 2.50 °C in the dry season. (ii) During the short-term future, largest SAT trends occur over the southeast and northwest ICP in wet and dry seasons, respectively. On regional average, the wet season is characterized by a significant warming rate of 0.22 °C decade−1, while it is non-significant with 0.11 °C decade−1for the dry season. For the long-term future, the rapid warming is strengthened significantly over whole ICP, with trends of 0.51 °C decade−1and 0.42 °C decade−1in wet and dry seasons,respectively. (iii) In the long-term future, more conspicuous warming is noted, especially in the wet season, due to the increased downward longwave radiation. Higher CO2concentrations enhancing the greenhouse effect can be attributed to the water vapor–greenhouse feedback, which, affecting atmospheric humidity and counter radiation, leads to the rising SAT

Added value of the regionally coupled model ROM in the East Asian summer monsoon modeling

The performance of the regional atmosphere-ocean coupled model ROM (REMO-OASIS-MPIOM) is compared with its atmospheric component REMO in simulating the East Asian summer monsoon (EASM) during the time period 1980–2012 with the following results being obtained. (1) The REMO model in the standalone configuration with the prescribed sea surface conditions produces stronger low-level westerlies associated with the South Asian summer monsoon, an eastward shift of the western Pacific subtropical high (WPSH) and a wetter lower troposphere, which jointly lead to moisture pathways characterized by stronger westerlies with convergence eastward to the western North Pacific (WNP). As a consequence, the simulated precipitation in REMO is stronger over the ocean and weaker over the East Asian continent than in the observational datasets. (2) Compared with the REMO results, lower sea surface temperatures (SSTs) feature the ROM simulation with enhanced air-sea exchanges from the intensified low-level winds over the subtropical WNP, generating an anomalous low-level anticyclone and hence improving simulations of the low-level westerlies and WPSH. With lower SSTs, ROM produces less evaporation over the ocean, inducing a drier lower troposphere. As a result, the precipitation simulated by ROM is improved over the East Asian continent but with dry biases over the WNP. (3) Both models perform fairly well for the upper level circulation. In general, compared with the standalone REMO model, ROM improves simulations of the circulation associated with the moisture transport in the lower- to mid-troposphere and reproduces the observed EASM characteristics, demonstrating the advantages of the regionally coupled model ROM in regions where air-sea interactions are highly relevant for the East Asian climate

Hybrid Biodegradable Nanomotors through Compartmentalized Synthesis

Designer particles that are embued with nanomachinery for autonomous motion have great potential for biomedical applications; however, their development is highly demanding with respect to biodegradability/compatibility. Previously, biodegradable propulsive machinery based on enzymes has been presented. However, enzymes are highly susceptible to proteolysis and deactivation in biological milieu. Biodegradable hybrid nanomotors powered by catalytic inorganic nanoparticles provide a proteolytically stable alternative to those based upon enzymes. Herein we describe the assembly of hybrid biodegradable nanomotors capable of transducing chemical energy into motion. Such nanomotors are constructed through a process of compartmentalized synthesis of inorganic MnO2 nanoparticles (MnPs) within the cavity of organic stomatocytes. We show that the nanomotors remain active in cellular environments and do not compromise cell viability. Effective tumor penetration of hybrid nanomotors is also demonstrated in proof-of-principle experiments. Overall, this work represents a new prospect for engineering of nanomotors that can retain their functionality within biological contexts

Salmon Calcitonin Exerts an Antidepressant Effect by Activating Amylin Receptors

Depressive disorder is defined as a psychiatric disease characterized by the core symptoms of anhedonia and learned helplessness. Currently, the treatment of depression still calls for medications with high effectiveness, rapid action, and few side effects, although many drugs, including fluoxetine and ketamine, have been approved for clinical usage by the Food and Drug Administration (FDA). In this study, we focused on calcitonin as an amylin receptor polypeptide, of which the antidepressant effect has not been reported, even if calcitonin gene-related peptides have been previously demonstrated to improve depressive-like behaviors in rodents. Here, the antidepressant potential of salmon calcitonin (sCT) was first evaluated in a chronic restraint stress (CRS) mouse model of depression. We observed that the immobility duration in CRS mice was significantly increased during the tail suspension test and forced swimming test. Furthermore, a single administration of sCT was found to successfully rescue depressive-like behaviors in CRS mice. Lastly, AC187 as a potent amylin receptor antagonist was applied to investigate the roles of amylin receptors in depression. We found that AC187 significantly eliminated the antidepressant effects of sCT. Taken together, our data revealed that sCT could ameliorate a depressive-like phenotype probably via the amylin signaling pathway. sCT should be considered as a potential therapeutic candidate for depressive disorder in the future

Reservoir space of the Es33–Es41 shale in Dongying sag

The Es33–Es41 shales in Dongying sag are source rocks with large reserves of shale oil and gas. For the identification of development characteristics and geological significance of the reservoir space, FMI logging, core observation, thin section analysis, X-ray diffraction, fluorescence microscopy, scanning electron microscopy, mercury porosimetry, low-temperature nitrogen adsorption, atomic force microscopy, and conventional physical property testing were used to study the petrology and reservoir space of the Es33–Es41 shale in Dongying sag. The results suggest that the shale is rich in carbonate minerals. Phanerocrystalline stratiform and lamellar argillaceous limestone and calcareous claystone are the oil- and gas-bearing lithofacies. The oil in the micropores is mainly present as membranes and clots. The shale reservoir space has a network structure with veins, carbonate and clay minerals, and micropores among pyrite and the matrix. The results provide the geological framework for future shale oil and gas exploration in Dongying sag. Keywords: Shale, Oil, Gas, Reservoir space, Dongying sa

Attribution and Causality Analyses of Regional Climate Variability

A two-step attribution and causality diagnostic is designed by employing singular spectrum analysis to unfold the attributed climate time series into a trajectory matrix and then subjected to an empirical orthogonal function analysis to identify the evolving driving forces, which can finally be related to major climate modes through their independent frequencies by wavelet analysis. Application results from the arid and drought-prone southern Intermountain region of North America are compared with the climate or larger scale forcing diagnosed from slow feature analysis using the sources of the water and energy flux balance. The following results are noted: (i) The changes between the subsequent four 20-year periods from 1930 to 2010 suggest predominantly climate-induced forcing by the Pacific Decadal Oscillation and the Atlantic Multidecadal Oscillation. (ii) Land cover influences on the changing land cover are of considerably smaller magnitude (in terms of area percentage cover) whose time evolution is well documented from forestation documents. (iii) The drivers of the climate-induced forcings within the last 20 years are identified as the quasi-biennial oscillation and the El Niño–Southern Oscillation by both the inter-annual two-step attribution and the causality diagnostics with monthly scale-based slow feature analysis

Recent advances in permeable polymersomes:fabrication, responsiveness, and applications

Polymersomes are vesicular nanostructures enclosed by a bilayer-membrane self-assembled from amphiphilic block copolymers, which exhibit higher stability compared with their biological analogues (e.g. liposomes). Due to their versatility, polymersomes have found various applications in different research fields such as drug delivery, nanomedicine, biological nanoreactors, and artificial cells. However, polymersomes prepared with high molecular weight components typically display low permeability to molecules and ions. It hence remains a major challenge to balance the opposing features of robustness and permeability of polymersomes. In this review, we focus on the design and strategies for fabricating permeable polymersomes, including polymersomes with intrinsic permeability, the formation of nanopores in the membrane bilayers by protein insertion, and the construction of stimuli-responsive polymersomes. Then, we highlight the applications of permeable polymersomes in the fields of biomimetic nanoreactors, artificial cells and organelles, and nanomedicine, to underline the challenges in the development of polymersomes as soft matter with biomedical utilities.</p

Impacts of Indian Ocean Dipole–Like SST on Rice Yield Anomalies in Jiangsu Province

One of the main water vapor sources of eastern China is the Bay of Bengal, over which the circulation is influenced by the Tropical Indian Ocean Dipole (TIOD). The TIOD has a long-lasting effect on weather patterns, which in turn influence the rice yield and quality in eastern China, such as in Jiangsu Province. To identify the main mechanism involved, we perform a detailed investigation of the connections between the TIOD-like sea surface temperature (SST) and the climatic suitability for growing rice, and the subsequent rice yield anomalies, in Jiangsu Province. In particular, we compare the relationships, and identify the underlying mechanisms, of TIOD SST with suitable sunshine duration, temperature and precipitation during the period of rice culture in the province. Singular Value Decomposition (SVD) results show that the TIOD-like SST has a close correlation with the rice yield anomalies, with a temporal correlation coefficient of 0.43 for 53 years, passing the 99% significance level. Furthermore, in the negative TIOD-like SST years, the background circulation weakens the transport effect of the atmospheric river through which water vapor is transported from the Bay of Bengal to eastern China. This decreased amount of transported water vapor decreases the precipitation and total cloud cover in the province. In turn, this significantly increases the sunshine duration, which plays a key role in rice yield anomalies. The increased sunshine duration and higher temperatures lead to positive rice yield anomalies, and vice versa. Our findings highlight that climatic factors, such as TIOD-like SST, have a far-reaching influence on agricultural production (in this case, rice yield), and thus special attention should be paid to interdisciplinary research in the fields of climate and agriculture