Deformation and Hochschild Cohomology of Coisotropic Algebras

Coisotropic algebras consist of triples of algebras for which a reduction can be defined and unify in a very algebraic fashion coisotropic reduction in several settings. In this paper we study the theory of (formal) deformation of coisotropic algebras showing that deformations are governed by suitable coisotropic DGLAs. We define a deformation functor and prove that it commutes with reduction. Finally, we study the obstructions to existence and uniqueness of coisotropic algebras and present some geometric examples.Comment: 26 pages, comments are welcome

Mechanisms of HsSAS-6 assembly promoting centriole formation in human cells

SAS-6 proteins are thought to impart the ninefold symmetry of centrioles, but the mechanisms by which their assembly occurs within cells remain elusive. In this paper, we provide evidence that the N-terminal, coiled-coil, and C-terminal domains of HsSAS-6 are each required for procentriole formation in human cells. Moreover, the coiled coil is necessary and sufficient to mediate HsSAS-6 centrosomal targeting. High-resolution imaging reveals that GFP-tagged HsSAS-6 variants localize in a torus around the base of the parental centriole before S phase, perhaps indicative of an initial loading platform. Moreover, fluorescence recovery after photobleaching analysis demonstrates that HsSAS-6 is immobilized progressively at centrosomes during cell cycle progression. Using fluorescence correlation spectroscopy and three-dimensional stochastic optical reconstruction microscopy, we uncover that HsSAS-6 is present in the cytoplasm primarily as a homodimer and that its oligomerization into a ninefold symmetrical ring occurs at centrioles. Together, our findings lead us to propose a mechanism whereby HsSAS-6 homodimers are targeted to centrosomes where the local environment and high concentration of HsSAS-6 promote oligomerization, thus initiating procentriole formation

Excellent Silicon Surface Passivation Achieved by Industrial Inductively Coupled Plasma Deposited Hydrogenated Intrinsic Amorphous Silicon Suboxide

We present an alternative method of depositing a high-quality passivation film for heterojunction silicon wafer solar cells, in this paper. The deposition of hydrogenated intrinsic amorphous silicon suboxide is accomplished by decomposing hydrogen, silane, and carbon dioxide in an industrial remote inductively coupled plasma platform. Through the investigation on CO2 partial pressure and process temperature, excellent surface passivation quality and optical properties are achieved. It is found that the hydrogen content in the film is much higher than what is commonly reported in intrinsic amorphous silicon due to oxygen incorporation. The observed slow depletion of hydrogen with increasing temperature greatly enhances its process window as well. The effective lifetime of symmetrically passivated samples under the optimal condition exceeds 4.7 ms on planar n-type Czochralski silicon wafers with a resistivity of 1 Ωcm, which is equivalent to an effective surface recombination velocity of less than 1.7 cms−1 and an implied open-circuit voltage (Voc) of 741 mV. A comparison with several high quality passivation schemes for solar cells reveals that the developed inductively coupled plasma deposited films show excellent passivation quality. The excellent optical property and resistance to degradation make it an excellent substitute for industrial heterojunction silicon solar cell production

Mitigation of Open‐Circuit Voltage Losses in Perovskite Solar Cells Processed over Micrometer‐Sized‐Textured Si Substrates

The recent development of solution-processed perovskite thin films over micrometer-sized textured silicon bottom solar cells enables tandem solar cells with power conversion efficiencies > 30%. Next to improved light harvesting, textured silicon wafers are the industrial standard. To achieve high performance, the open-circuit voltage losses that occur when fabricating perovskite solar cells over such textures need to be mitigated. This study provides a practical guideline to discriminate and address the voltage losses at the interfaces as well as in the bulk of solution-processed double cation perovskite thin films using photoluminescence quantum yield measurements. Furthermore, the origin of these losses is investigated via morphological, microstructural, and compositional analysis and present possible mitigation strategies. The guideline will be beneficial for scientists working on randomly textured surfaces and provides a deeper understanding on this timely research topic

Oxide‐Based Solid‐State Batteries: A Perspective on Composite Cathode Architecture

The garnet-type phase Li$_7$La$_3$Zr$_2$O$_{12}$ (LLZO) attracts significant attention as an oxide solid electrolyte to enable safe and robust solid-state batteries (SSBs) with potentially high energy density. However, while significant progress has been made in demonstrating compatibility with Li metal, integrating LLZO into composite cathodes remains a challenge. The current perspective focuses on the critical issues that need to be addressed to achieve the ultimate goal of an all-solid-state LLZO-based battery that delivers safety, durability, and pack-level performance characteristics that are unobtainable with state-of-the-art Li-ion batteries. This perspective complements existing reviews of solid/solid interfaces with more emphasis on understanding numerous homo- and heteroionic interfaces in a pure oxide-based SSB and the various phenomena that accompany the evolution of the chemical, electrochemical, structural, morphological, and mechanical properties of those interfaces during processing and operation. Finally, the insights gained from a comprehensive literature survey of LLZO–cathode interfaces are used to guide efforts for the development of LLZO-based SSBs

Functional specialization of Piwi proteins in Paramecium tetraurelia from post-transcriptional gene silencing to genome remodelling

Proteins of the Argonaute family are small RNA carriers that guide regulatory complexes to their targets. The family comprises two major subclades. Members of the Ago subclade, which are present in most eukaryotic phyla, bind different classes of small RNAs and regulate gene expression at both transcriptional and post-transcriptional levels. Piwi subclade members appear to have been lost in plants and fungi and were mostly studied in metazoa, where they bind piRNAs and have essential roles in sexual reproduction. Their presence in ciliates, unicellular organisms harbouring both germline micronuclei and somatic macronuclei, offers an interesting perspective on the evolution of their functions. Here, we report phylogenetic and functional analyses of the 15 Piwi genes from Paramecium tetraurelia. We show that four constitutively expressed proteins are involved in siRNA pathways that mediate gene silencing throughout the life cycle. Two other proteins, specifically expressed during meiosis, are required for accumulation of scnRNAs during sexual reproduction and for programmed genome rearrangements during development of the somatic macronucleus. Our results indicate that Paramecium Piwi proteins have evolved to perform both vegetative and sexual functions through mechanisms ranging from post-transcriptional mRNA cleavage to epigenetic regulation of genome rearrangements