Formation mechanism of CaCO3 spherulites in myostracum layer of limpet sahells

The authors would like to thank EPSRC for financial support on FEG-SEM equipment (EP/F019580/1) and FEI Scios dualbeam microscope (EP/L017008/01).CaCO3 spherulites were found in the myostracum layer of common limpet shells collected from East Sands, St Andrews, Scotland. Their microstructures were revealed by using powder X- ray diffraction, scanning electron microscopy, high resolution transmission electron microscopy, and energy dispersive X-ray microanalysis. The formation mechanisms of these spherulites and their morphology evolution were postulated. It was proposed that spherical particles of an inorganic and biological composite formed first. In the centre of each spherical particle was developed a double-layer disk of vaterite crystal sandwiching a biological sheet. The disk crystal supplies a relatively strong mirror symmetric dipole filed, guiding the orientations of the nanocrystallites and the arrangement of mesorods, and therefore, determining the final morphology of the spherulite.Publisher PDFPeer reviewe

Characterization and mass formulas of symplectic self-orthogonal and LCD codes and their application

The object of this paper is to study two very important classes of codes in coding theory, namely self-orthogonal (SO) and linear complementary dual (LCD) codes under the symplectic inner product, involving characterization, constructions, and their application. Using such a characterization, we determine the mass formulas of symplectic SO and LCD codes by considering the action of the symplectic group, and further obtain some asymptotic results. Finally, under the Hamming distance, we obtain some symplectic SO (resp. LCD) codes with improved parameters directly compared with Euclidean SO (resp. LCD) codes. Under the symplectic distance, we obtain some additive SO (resp. additive complementary dual) codes with improved parameters directly compared with Hermitian SO (resp. LCD) codes. Further, we also construct many good additive codes outperform the best-known linear codes in Grassl's code table. As an application, we construct a number of record-breaking (entanglement-assisted) quantum error-correcting codes, which improve Grassl's code table

Crepe cake structured layered double hydroxide/sulfur/graphene as a positive electrode material for Li-S batteries

This work was financially supported by National Natural Science Foundation of China (Nos. 21975030 and 11674005), and the Ministry of Science and Technology of China (No. 2016YFB0700600 (National Materials Genome Project)).Solving the polysulfide shuttle problem is one of the core challenges for the industrialization of lithium–sulfur batteries. In this work, a triphasic composite of LDH/sulfur/rGO (LDH: layered double hydroxide, rGO: reduced graphene oxide) with a crepe cake like structure is designed and fabricated as a positive electrode material for lithium–sulfur batteries. Sulfur nanoparticles are embedded in the interlayer space of the composite and thus are well protected physically via three-dimensional wrapping and chemically via strong interaction of LDH nanoflakes with lithium polysulfides, such as ionic bonds and S···H hydrogen bonds. In addition, the flexible lamellar structure of the composite with soft graphene layers can tolerate the volume expansion of sulfur during lithiation as well as facilitate ionic permeability and electron transport, which is favorable for the redox reactions of polysulfide. The present work sheds light on the future development and industrialization of lithium–sulfur batteries.PostprintPeer reviewe

Controllable ingestion and release of guest components driven by interfacial molecular orientation of host liquid crystal droplets

Controllable construction and manipulation of artificial multi-compartmental structures are crucial in understanding and imitating smart molecular elements such as biological cells and on-demand delivery systems. Here, we report a liquid crystal droplet (LCD) based three-dimensional system for controllable and reversible ingestion and release of guest aqueous droplets (GADs). Induced by interfacial thermodynamic fluctuation and internal topological defect, microscale LCDs with perpendicular anchoring condition at the interface would spontaneously ingest external components from the surroundings and transform them as radially assembled tiny GADs inside LCDs. Landau–de Gennes free-energy model is applied to describe and explain the assembly dynamics and morphologies of these tiny GADs, which presents a good agreement with experimental observations. Furthermore, the release of these ingested GADs can be actively triggered by changing the anchoring conditions at the interface of LCDs. Since those ingestion and release processes are controllable and happen very gently at room temperature and neutral pH environment without extra energy input, these microscale LCDs are very prospective to provide a unique and viable route for constructing hierarchical 3D structures with tunable components and compartments

Planetary Defense team project: READI (Roadmap for EArth Defense Initiatives)

Planetary Defense is a complex problem, not well understood by policy makers and the general public. The recent Chelyabinsk incident in Russia created temporary international attention but has failed to effectively stimulate public action. The lack of long-term attention to cosmic hazards has resulted in limited funding to defend our planet. Hence, it is hard to realistically address this challenge and achieve the high test and operational readiness needed for an effective Planetary Defense strategy. To address this problem, we have created a set of recommendations for the development of a Planetary Defense Program, for the purpose of contributing to the protection of Earth from asteroids and comets. The SSP15 READI Project focused on threats for which there is only a short-term warning, specifically a warning of two years or less from detection of the object to impact. We have provided recommendations in five areas of Planetary Defense including detection and tracking, deflection techniques, global collaboration, outreach and education, and evacuation and recovery. We have applied this set of recommendations in a narrative scenario to make our report more impactful and engaging. We contrast optimistic and pessimistic outcomes for a comet threat, differing from each other in terms of the level of readiness achieved during the years leading up to the discovery of the threat. In our optimistic scenario, the deflection system has achieved high test and operational readiness. The world’s governments have realized the importance of being prepared against cosmic hazards and put in place all of the necessary measures for a successful defense, leading to a positive deflection of the comet. In contrast, in the pessimistic scenario no preparation is done before the detection, and the comet strikes a heavily populated area releasing energy equivalent to 80 times the most powerful nuclear bomb ever detonated. The recommendations that we have identified in this report constitute a roadmap to avoid this horrible outcome, and we believe they should be taken seriously and swiftly implemented

Methylprednisolone as Adjunct to Endovascular Thrombectomy for Large-Vessel Occlusion Stroke

Importance It is uncertain whether intravenous methylprednisolone improves outcomes for patients with acute ischemic stroke due to large-vessel occlusion (LVO) undergoing endovascular thrombectomy. Objective To assess the efficacy and adverse events of adjunctive intravenous low-dose methylprednisolone to endovascular thrombectomy for acute ischemic stroke secondary to LVO. Design, Setting, and Participants This investigator-initiated, randomized, double-blind, placebo-controlled trial was implemented at 82 hospitals in China, enrolling 1680 patients with stroke and proximal intracranial LVO presenting within 24 hours of time last known to be well. Recruitment took place between February 9, 2022, and June 30, 2023, with a final follow-up on September 30, 2023.InterventionsEligible patients were randomly assigned to intravenous methylprednisolone (n = 839) at 2 mg/kg/d or placebo (n = 841) for 3 days adjunctive to endovascular thrombectomy. Main Outcomes and Measures The primary efficacy outcome was disability level at 90 days as measured by the overall distribution of the modified Rankin Scale scores (range, 0 [no symptoms] to 6 [death]). The primary safety outcomes included mortality at 90 days and the incidence of symptomatic intracranial hemorrhage within 48 hours. Results Among 1680 patients randomized (median age, 69 years; 727 female [43.3%]), 1673 (99.6%) completed the trial. The median 90-day modified Rankin Scale score was 3 (IQR, 1-5) in the methylprednisolone group vs 3 (IQR, 1-6) in the placebo group (adjusted generalized odds ratio for a lower level of disability, 1.10 [95% CI, 0.96-1.25]; P = .17). In the methylprednisolone group, there was a lower mortality rate (23.2% vs 28.5%; adjusted risk ratio, 0.84 [95% CI, 0.71-0.98]; P = .03) and a lower rate of symptomatic intracranial hemorrhage (8.6% vs 11.7%; adjusted risk ratio, 0.74 [95% CI, 0.55-0.99]; P = .04) compared with placebo. Conclusions and Relevance Among patients with acute ischemic stroke due to LVO undergoing endovascular thrombectomy, adjunctive methylprednisolone added to endovascular thrombectomy did not significantly improve the degree of overall disability.Trial RegistrationChiCTR.org.cn Identifier: ChiCTR210005172

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead