Rationale Accurate knowledge of the cellular composition of the heart is essential to fully understand the changes that occur during pathogenesis and to devise strategies for tissue engineering and regeneration. Objective To examine the relative frequency of cardiac endothelial cells, hematopoietic-derived cells and fibroblasts in the mouse and human heart. Methods and Results Using a combination of genetic tools and cellular markers, we examined the occurrence of the most prominent cell types in the adult mouse heart. Immunohistochemistry revealed that endothelial cells constitute over 60%, hematopoietic-derived cells 5–10%, and fibroblasts under 20% of the non-myocytes in the heart. A refined cell isolation protocol and an improved flow cytometry approach provided an independent means of determining the relative abundance of non-myocytes. High dimensional analysis and unsupervised clustering of cell populations confirmed that endothelial cells are the most abundant cell population. Interestingly, fibroblast numbers are smaller than previously estimated, and two commonly assigned fibroblast markers, Sca-1 and CD90, underrepresent fibroblast numbers. We also describe an alternative fibroblast surface marker that more accurately identifies the resident cardiac fibroblast population. Conclusions This new perspective on the abundance of different cell types in the heart demonstrates that fibroblasts comprise a relatively minor population. By contrast, endothelial cells constitute the majority of non-cardiomyocytes and are likely to play a greater role in physiologic function and response to injury than previously appreciated.

Major depressive disorder (MDD), one of the most frequently encountered forms of mental illness and a leading cause of disability worldwide1, poses a major challenge to genetic analysis. To date no robustly replicated genetic loci have been identified 2, despite analysis of more than 9,000 cases3. Using low coverage genome sequence of 5,303 Chinese women with recurrent MDD selected to reduce phenotypic heterogeneity, and 5,337 controls screened to exclude MDD, we identified and replicated two genome-wide significant loci contributing to risk of MDD on chromosome 10: one near the SIRT1 gene (P-value = 2.53×10−10) the other in an intron of the LHPP gene (P = 6.45×10−12). Analysis of 4,509 cases with a severe subtype of MDD, melancholia, yielded an increased genetic signal at the SIRT1 locus. We attribute our success to the recruitment of relatively homogeneous cases with severe illness.

Low-light live imaging of F-actin–selective probes, quantitative tools, and super-resolution microscopy reveals a dynamic, formin-dependent deep F-actin cytoskeletal network in axons.

Sulfur-stabilized intermetallic nanoparticles Nanoparticles of intermetallic alloys of platinum could have enhanced electronic properties that improve their catalytic activity, but the high temperatures needed to ensure complete atomic diffusion often lead to the growth of larger nanoparticles—sintering—with low surface area and hence low overall activity. Yang et al . show that sulfur-doped carbon supports create strong platinum-sulfur bonds that stabilize small platinum alloy nanoparticles (<5 nanometers in diameter) to temperatures up to 1000ºC. They screened libraries of platinum alloys and identified ones with high mass activity for the oxygen reduction reaction in hydrogen fuel cells. —PDS

Development of promising battery systems is being intensified to fulfil the needs of long-driving-ranged electric vehicles. The successful candidates for new generation batteries should have higher energy densities than those of currently used batteries and reasonable rechargeability. Here we report that aqueous lithium-iodine batteries based on the triiodide/ iodide redox reaction show a high battery performance. By using iodine transformed to triiodide in an aqueous iodide, an aqueous cathode involving the triiodide/iodide redox reaction in a stable potential window avoiding water electrolysis is demonstrated for lithium-iodine batteries. The high solubility of triiodide/iodide redox couples results in an energy density of B0.33 kWh kg À 1 , approximately twice that of lithium-ion batteries. The reversible redox reaction without the formation of resistive solid products promotes rechargeability, demonstrating 100 cycles with negligible capacity fading. A low cost, non-flammable and heavy-metal-free aqueous cathode can contribute to the feasibility of scale-up of lithium-iodine batteries for practical energy storage.

SUMMARY The normal functions and pathologic facets of the small presynaptic protein α-synuclein (α-syn) are of exceptional interest. In previous studies, we found that α-syn attenuates synaptic exo/endocytosis [1, 2]; however underlying mechanisms remain unknown. More recent evidence suggests that α-syn exists as metastable multimers and not solely as a natively-unfolded monomer [11-16]. However conformations of α-syn at synapses – its physiologic locale – are unclear; and potential implications of such higher-order conformations to synaptic function is unknown. Exploring α-syn conformations and synaptic function in neurons, we found that α-syn promptly organizes into physiological multimers at synapses. Furthermore, our experiments indicate that α-syn multimers cluster synaptic-vesicles and restrict their motility – suggesting a novel role for these higher-order structures. Supporting this, α-syn mutations that disrupt multimerization also fail to restrict synaptic-vesicle motility or attenuate exo/endocytosis. We propose a model where α-syn multimers cluster synaptic-vesicles, restricting their trafficking and recycling – consequently attenuating neurotransmitter release.

The AQI of Wuhan City decreased significantly, the higher the population density, the more significant the decline.• NO 2 decreased most in Wuhan, but O 3 increased significantly, and Hubei Province also had the same trend. • The mobile source emission ratio and the local pollution contribution in Wuhan decreased.

The prevalence of myopia and high myopia in this university student population was high. The refractive status of this population deserves further attention.