In this paper,the numerical simulation method is used to study the ballistic performances of hourglass lattice sandwich structures with the same mass under the vertical incidence of *** is paid to elucidating the infl...
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In this paper,the numerical simulation method is used to study the ballistic performances of hourglass lattice sandwich structures with the same mass under the vertical incidence of *** is paid to elucidating the influences of rod cross-section dimensions,structure height,structure layer,and rod inclination angle on the deformation mode,ballistic performances,and ability to change the ballistic direction of *** results show that the ballistic performances of hourglass lattice sandwich structures are mainly affected by their structural *** this respect,structural parameters optimization of the hourglass lattice sandwich structures enable one to effectively improve their ballistic limit velocity and,consequently,ballistic performances.
In flowering plants,the two sperm cells are passive cargo transported into the ovule by pollen tubes (Zhang et al.,2017).Therefore,the precise guidance of pollen tubes is critical for successful double fertilization (...
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In flowering plants,the two sperm cells are passive cargo transported into the ovule by pollen tubes (Zhang et al.,2017).Therefore,the precise guidance of pollen tubes is critical for successful double fertilization (Dresselhaus and Franklin-Tong,2013).A series of male-female interactions are required to guarantee the spatiotemporal regulation of pollen tube guidance because during growth,pollen tubes continuously interact with different female tissues (Zhong et al.,2017;Zhong and qu,2019).In the past two decades,there has been tremendous progress in elucidating the molecular mechanisms of pollen tube guidance regulation,mostly using Arabidopsis thaliana as a model system (Johnson et al.,2019).
Alloy-type metals/alloys hold the promise of increasing the energy density of metal-ion batteries(MIBs)because of their theoretical high gravimetrical *** and semimetal-analogs are typical alloy-type ***,the large-sca...
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Alloy-type metals/alloys hold the promise of increasing the energy density of metal-ion batteries(MIBs)because of their theoretical high gravimetrical *** and semimetal-analogs are typical alloy-type ***,the large-scale extraction of semimetals(Si,Ge)and semimetal-analogs(Sb,Bi,Sn)by traditional metallurgical routes highly relies on using reducing agents(e.g.,carbon,hydrogen,reactive metals),which consumes a large number of fossil fuels and produces greenhouse gas *** addition,the common metallurgical methods for extracting semimetals involve relatively high operating temperatures and therefore produce bulk metal ingots solidified from the liquid ***,the commonly used electrode materials in batteries are fine ***,directly producing semimetal powders would be more energy *** addition,semimetals are good candidates to host alkali/alkaline-earth ions through the alloying process because the electronegativity of semimetals is ***,preparing semimetal powders via an environment-sound manner is of great interest to provide sustainable anode materials for MIBs while reducing the ecological ***-cost and high-output capacity anode powder materials,as well as straightforward and environmental-benign synthetic methods,play key roles in enabling the energy conversion and storage technologies for real applications of *** technologies offer new strategies to extract semimetals using electrons as the reducing agent that comes from renewable ***,the morphologies and structures of the electrolytic products can be rationally tailored by tuning the electrode potentials,electrolytes,and operating *** this regard,using the one-step green electrochemical method to prepare high-capacity and cheaper alloy-type metalloids for MIB anodes can fulfill the requirements for developing *** review critically overviews recent developments and advances in the elect
In angiosperms,the molecular mechanism controlling polytubey/polyspermy block and fertilization recovery was not unraveled until recently(Zhong et al.,2022),which can be described as fol ows:Five pol en tube-expressed...
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In angiosperms,the molecular mechanism controlling polytubey/polyspermy block and fertilization recovery was not unraveled until recently(Zhong et al.,2022),which can be described as fol ows:Five pol en tube-expressed RALF peptide ligands,perceived by the receptor complex composed of three receptors FER/ANJ/HERK1 at the septum,establish the polytubey block at the septum so that only one pollen tube is allowed to emerge from the septum to target the ovule for *** tube rupture releases the two sperm cells and fertilization is completed within 20 min.
The Mediator complex is an important component of the eukaryotic transcriptional machinery. As an essential link between transcription factors and RNA polymerase II, the Mediator complex transduces diverse signals to ...
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The Mediator complex is an important component of the eukaryotic transcriptional machinery. As an essential link between transcription factors and RNA polymerase II, the Mediator complex transduces diverse signals to genes involved in different pathways. The plant Mediator complex was recently purified and comprises conserved and specific subunits. It functions in concert with transcription factors to modulate various responses. In this review, we summarize the recent advances in understanding the plant Mediator complex and its diverse roles in plant growth, development, defense, non-coding RNA production, response to abiotic stresses, flowering, genomic stability and metabolic homeostasis. In addition, the transcription factors interacting with the Mediator complex are also highlighted.
In November 2005, scientists gathered at Times Square in New York City announced the exciting news of the successful development of the world's first cervical cancer vaccine. The cervical cancer vaccine, which is abl...
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In November 2005, scientists gathered at Times Square in New York City announced the exciting news of the successful development of the world's first cervical cancer vaccine. The cervical cancer vaccine, which is able to protect unexposed women against the infection with four HPV strains responsible for 70% of cervical cancers, was approved for human use by the US Federal Drug Administration (FDA) and a number of other countries.
Ubiquitination of proteins is one of the critical regulatory mechanisms in eukaryotes. In higher plants, protein ubiquitination plays an essential role in many biological processes, including hormone signaling, photom...
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Ubiquitination of proteins is one of the critical regulatory mechanisms in eukaryotes. In higher plants, protein ubiquitination plays an essential role in many biological processes, including hormone signaling, photomorphogenesis, and pathogen defense. However, the roles of protein ubiquitination in the repro- ductive process are not clear. In this study, we identified four plant-specific RING-finger genes designated Aberrant_Pollen Development 1_ (APD1) to APD4, as regulators of pollen mitosis II (PMII) in Arabidopsis thaliana (L.). The apdl apd2 double mutant showed a significantly increased percentage of bicellular-like pollen at the mature pollen stage. Further downregulation of the APD3 and APD4 transcripts in apdl apd2 by RNA interference (RNAi) resulted in more severe abnormal bicellular-like pollen phenotypes than in apdl apd2, suggesting that cell division was defective in male gametogenesis. All of the four genes were expressed in multiple stages at different levels during male gametophyte development. Confocal analysis using green florescence fusion proteins (GFP) GFP-APD1 and GFP-APD2 showed that APDs are associated with intracellular membranes. Furthermore, APD2 had E2-dependent E3 ligase activity in vitro, and five APD2-interacting proteins were identified. Our results suggest that these four genes may be involved, redundantly, in regulating the PMII process during male gametogenesis.
Sexual reproduction in higher plants consists of several major biological processes which include mega- and micro-gametogenesis, male-female communications, embryogenesis and endosperm development. Male-female communi...
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Sexual reproduction in higher plants consists of several major biological processes which include mega- and micro-gametogenesis, male-female communications, embryogenesis and endosperm development. Male-female communications include male gametophyte-sporophytic tissues (stigma/transmitting tract) interaction and male-female gametophyte communication, during which various signaling pathways are involved.
In angiosperms, initiation of ovule enlargement represents the start of seed development, the molecular mechanism of which is not yet elucidated. It was previously reported that pollen tube contents, rather than doubl...
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In angiosperms, initiation of ovule enlargement represents the start of seed development, the molecular mechanism of which is not yet elucidated. It was previously reported that pollen tube contents, rather than double fertilization, can trigger ovule enlargement. However, it remains unclear whether the signal(s) to trigger the initiation of ovule enlargement are from the sperm cells or fromthe pollen tubes. Recently, we identified a mutant dropl- drop2-, which produces pollen tubes with no sperm cells. Taking advantage of this special genetic material, we conducted pollination assays, and found that the ovules pollinated with dropl- drop2- pollen could initiate the enlargement and exhibited significant enlarged sizes at 36h after pollination in comparison with those unpollinated ovules. However, the sizes of the ovules pollinated with drops- drop2- pollen are significantly smaller than those of the ovules pollinated with wildtype pollen. These results demonstrate that the pollen tube, rather than the sperm cells, release the signal to trigger the initiation of ovule enlargement, and that double fertilization is required for further enlargement of the seeds.
A new study provides a comprehensive molecular mechanism that controls interspecific incompatibility of self-incompatible(SI)plants in the *** finding points to a potentially promising path to break interspecific barr...
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A new study provides a comprehensive molecular mechanism that controls interspecific incompatibility of self-incompatible(SI)plants in the *** finding points to a potentially promising path to break interspecific barriers and achieve introgression of desirable traits into crops from distant species among SI crops in the Brassicaceae.
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