High-stability spherical lanthanide nanoclusters for magnetic resonance imagingOA

High-nuclear lanthanide clusters have shown great potential for the administration of high-dose mononuclear gadolinium chelates in magnetic resonance imaging(MRI). The development of high-nuclear lanthanide clusters with excellent solubility and high stability in water or solution has been challenging and is very important for expanding the performance of MRI. We used N-methylbenzimidazole-2-methanol(HL) and LnCl₃·6H₂O to synthesize two spherical lanthanide clusters, Ln     

Challenges and opportunities for modeling coupled human and natural systemsOA

<正>The Earth is a very large and complex system that consists of human and natural components interacting bidirectionally with each other,thus forming coupled human and natural systems (CHANS)[1].The increasing dominance of human impacts,especially after the 1950s [2],marked a new era for the Earth,the Anthropocene,which means humans have become the main drivers of the evolution of changes in the Earth system.Therefore,modeling CHANS is essential for understanding the emergent system prope...     

Unexpected giant negative area compressibility in palladium diselenide

Negative area compressibility(NAC) is a counterintuitive ’squeeze-expand’ behavior in solids that is very rare but attractive due to possible pressure-response applications and coupling with rich physicochemical properties.Herein,NAC behavior is reported in palladium diselenide with a large magnitude and wide pressure range.We discover that,apart from the rigid flattening of layers that has been generally recognized,the unexpected giant NAC effect in PdSe₂ largely comes from anomalous...     

A neuron-immune circuit regulates neurodegeneration in the hindbrain and spinal cord of Arf1-ablated mice

Neuroimmune connections have been revealed to play a central role in neurodegenerative diseases(NDs).However, the mechanisms that link the central nervous system(CNS) and peripheral immune cells are still mostly unknown. We recently found that specific ablation of the Arf1 gene in hindbrain and spinal cord neurons promoted NDs through activating the NLRP3 inflammasome in microglia via peroxided lipids and adenosine triphosphate(ATP) releasing. Here, we demonstrate that IL-1β with elevated chemok...     

Bioprocess inspired formation of calcite mesocrystals by cation-mediated particle attachment mechanismOA

Calcite mesocrystals were proposed, and have been widely reported, to form in the presence of polymer additives via oriented assembly of nanoparticles. However, the formation mechanism and the role of polymer additives remain elusive. Here, inspired by the biomineralization process of sea urchin spine comprising magnesium calcite mesocrystals, we show that calcite mesocrystals could also be obtained via atachment of amorphous calcium carbonate(ACC) nanoparticles in the presence of inorganic zinc...     

Comparative orotomy of the Archean Superior and Phanerozoic Altaid orogenic systems

We compare and contrast the materials and mechanisms of continental crustal growth in the largest preserved regions of Phanerozoic and Archean juvenile additions to the crust,to test for similarities or differences in the formation of continents through time.We accomplish this through a comparison of map patterns,lithological contents,and structural and metamorphic evolution of the Phanerozoic Altaid orogenic system of Asia,with the Archean Superior Province of the North American Craton,using a ...     

Studies of Solar Vector Magnetic Field

In this article,we report a few advances in the studies based on the solar vector magnetic field observations which were carried out mainly with the Solar Magnetic Field Telescope at the Huairou Solar Observing Station in the 1990s.(1) We developed necessary methodology and concepts in vector magnetogram analysis(Wang et al.1996).For the first time,we proposed to use the photospheric free magnetic energy to quantify the major flare productivity of solar active regions(ARs),and it had been proved to be the best parameter in representing the major flare activity.(2) We revealed that there was always a dominant sense of magnetic shear in a given AR(Wang 1994),which was taken as the premise of the helicity calculation in ARs;we made the first quantitative estimation of magnetic helicity evolution in ARs(Wang 1996).(3) We identified the first group of evidence of magnetic reconnection in the lower solar atmosphere with vector magnetic field observations and proposed a two-step reconnection flare model to interpret the observed association of flux cancellation and flares(Wang and Shi 1993).Efforts to quantify the major flare productivity of super active regions with vector magnetic field observations have been also taken.     

High-timing-precision detection of single X-ray photons by superconducting nanowiresOA

Precisely acquiring the timing information of individual X-ray photons is important in both fundamental research and practical applications. The timing precision of commonly used X-ray single-photon detectors remains in the range of one hundred picoseconds to microseconds. In this work, we report on high-timing-precision detection of single X-ray photons through the fast transition to the normal state from the superconductive state of superconducting nanowires. We successfully demonstrate a free...     

Novel Progress in Rewritable High Density Optical Data Storage Technology

In collaboration with colleagues at the University of Science and Technology of China and East China University of Science and Technology, CAS researchers from the Institute of Chemistry have synthesized a novel spironaphthoxazine SOFC molecule with a stable ringopened photomerocyanine form by incorporating a ferrocene moiety to the parent spironaphthoxazine. Their work has been reported in a recent issue of Advanced Materials.     

MAGUS: machine learning and graph theory assisted universal structure searcherOA

Crystal structure predictions based on first-principles calculations have gained great success in materials science and solid state physics.However,the remaining challenges still limit their applications in systems with a large number of atoms,especially the complexity of conformational space and the cost of local optimizations for big systems.Here,we introduce a crystal structure prediction method,MAGUS,based on the evolutionary algorithm,which addresses the above challenges with machine learni...     

Bridging Institutional and Continental Gaps through Scientific Excellence——An Interview with Dr.Abiodun Humphrey Adebayo at the Institute of Microbiology

The interview with Abio 1 and his supervisor Prof. ZHANG Lixin took place on a chilly December day towards the end of 2012, after a heavy snow had blanketed Beijing city. In Prof. Zhang’s cozy office at the Institute of Microbiology, the Chinese Academy of Sciences (IMCAS), Abio welcomed the reporter with a firm handshake and a sunny smile. Three months after arriving in Beijing, this tall, outgoing and hard-working Nigerian has well adapted himself to the work and life here.     

Sexually Dimorphic Tridimensionally Preserved Pterosaurs and Their Eggs

<正>The pterosaur record is generally poor,with little information about their populations,and pterosaur eggs are even more rare,with only four isolated and flattened eggs found to date.Dr.WANG Xiaolin,Institute of Vertebrate Paleontology and Paleoanthropology(IVPP)of the Chinese Academy of Sciences(CAS),and his team revealed a new pterosaur-rich area with potentially thousands of bones,including tridimensionally preserved male and female skulls and eggs discovered together for the fi rst time in the Early Cretaceous deposit of the TurpanHami Basin,south of the Tian Shan Mountains in Xinjiang Uygur Autonomous Region,northwestern China.On June 6,the researchers reported online a population of a new sexually dimorphic pterosaur species(Hamipterus tianshanensis gen.et sp.nov.),with five exceptionally well-preserved three-dimensional eggs in Current Biology,providing new and important evidence regarding male and     

The β-relaxation in metallic glasses

Focusing on metallic glasses as model systems, we review the features and mechanisms of the β-relaxations,which are intrinsic and universal to supercooled liquids and glasses, and demonstrate their importance in understanding many crucial unresolved issues in glassy physics and materials science, including glass transition phenomena, mechanical properties, shear-banding dynamics and deformation mechanisms,difusion and the breakdown of the Stokes–Einstein relation as well as crystallization and stability of glasses.We illustrate that it is an atractive prospect to incorporate these insights into the design of new glassy materials with extraordinary properties. We also outline important questions regarding the nature ofβ-relaxations and highlight some emerging research directions in this still-evolving ield.     

Bacteria in ice may record climate change

To many people, bacteria and climate change are like chalk and cheese： the smallestcreature versus one of the biggestphenomena on Earth. Not really. Scientists with the CAS Institute of Tibetan Plateau Research （ITP） and coworkers recently reported thatsmall bugs deposited in ice and snow might tell how our climate has been changing.     

Superscattering of water wavesOA

Inspired by the concept of superscattering in optics,we for the first time theoretically predict and experimentally demonstrate the superscattering phenomenon in water waves.The subwavelength superscatterer is constructed by multi-layered concentric cylinders with an inhomogeneous depth profile.The superscatterer breaks the long-held single-channel scattering limit by several times and thus significantly enhances the total scattering strength.The underlying mechanism originates from the near deg...     

Application of Stem-Cell Technique for Diagnosis and Treatment of Cancer and Other Major Chronic Diseases

<正>Stem-cell technique has huge potential in diseases treatment.Current clinical trials of stem cells involve a wide range of diseases,including bacterial and fungal diseases,behavioral and psychiatric disorders,blood and lymphatic disease,cancers and other tumors,digestive diseases,heart and blood disorders,immune system diseases,oral and dental diseases,muscle,bone and cartilage diseases,neurological diseases,and reproduction-related diseases.1.Stem cells involve in the diagnosis and treatment of neoplastic diseases Cancer is one of the major diseases that threaten human life.Due to a lack of systematic understanding of its occurrence and development mechanism,there is no effective cure for it now.With the deepening research on stem cells,researchers found that some tumor cells are quite similar to stem cells.In 2001,Professor Weissman of     

中国清风藤科的初步研究

 This paper is a preliminary study on the Sabiaceae in aspects of its morphology, taxonomy and geography.  We propose that the Sabioideae and Meliosmoideae as two new subfamilies of Sabiaceae according to the external morphology, flower structure and geographical distribution of these two genera respectively.       This paper follows the taxonomic concepts of Luetha Chen on Sabia and C. F. van Beusekom on Meliosma.  We agree with them for their classification of these two genera above the specific rank.  As to the revision work of Sabia by van de Water and C. F. van Beusekom’s work on Meliosma we disagree  for their unduly broad specific concepts.  We rather treat the species of these two genera according to their habitats in regions on a relatively narrower sense.  The genus Sabia of China are classified into 2 tribes, with 16 species, 5 subspecies and 2 varieties in which 4 sub- species and l variety are as new combinations, the genus of Meliosma in China are classified into 2 subgenera with 29 species, and 7 varieties of which 4 varieties are new combinations.       After examining the affinity of the species of Sabia and Meliosma in China and its neighboring nations such as Burma, Japan and Bhutan, we found that their migra- tion initiated from China, as the primitive species of these two genera occured in northeast and central part of Yunnan, sou theast of Sichuan, north of Guizhou and west of Hubei, the region may probably be the main origin of these two genera.      As shown in tables 1 & 2, the localities where the species of these two genera den- sely populate they are from Yunnan, Guangxi, and Guangdong coinciding with the concepts of C. F. van Beusekom and van de Water about the distribution of exotic species of these two genera, it may reasonable be pointed out that the center of distri- bution of these two genera is Yunnan, Guangxi, Guangdong and nieghboring nations, upper Burma and northern Vietnam.  Futhermore, it may be seen that starting from this center the number of species become less and less as they proceed far and far awaybut become more advance in evolution.