Superconductivity above 30 K achieved in dense scandium

Superconductivity is one of most intriguing quantum phenomena, and the quest for elemental superconductors with high critical temperature (Tc) is of great scientific significance due to their relatively simple material composition and the underlying mechanism. Here we report the experimental discovery of densely compressed scandium (Sc) becoming the first elemental superconductor with Tc breaking into 30 K range, which is comparable to the Tc values of the classic La-Ba-Cu-O or LaFeAsO superconductors. Our results show that Tconset of Sc increases from ~3 K at around 43 GPa to ~32 K at about 283 GPa (Tczero ~ 31 K), which is well above liquid neon temperature. Interestingly measured Tc shows no sign of saturation up to the maximum pressure achieved in our experiments, indicating that Tc might be even higher upon further compression.Comment: 22 pages, 16 figure

Superconductivity above 70 K observed in lutetium polyhydrides

The binary polyhydrides of heavy rare earth lutetium that shares a similar valence electron configuration to lanthanum have been experimentally discovered to be superconductive. The lutetium polyhydrides were successfully synthesized at high pressure and high temperature conditions using a diamond anvil cell in combinations with the in-situ high pressure laser heating technique. The resistance measurements as a function of temperature were performed at the same pressure of synthesis in order to study the transitions of superconductivity (SC). The superconducting transition with a maximum onset temperature (Tc) 71 K was observed at pressure of 218 GPa in the experiments. The Tc decreased to 65 K when pressure was at 181 GPa. From the evolution of SC at applied magnetic fields, the upper critical field at zero temperature {\mu}0Hc2(0) was obtained to be ~36 Tesla. The in-situ high pressure X-ray diffraction experiments imply that the high Tc SC should arise from the Lu4H23 phase with Pm-3n symmetry that forms a new type of hydrogen cage framework different from those reported for previous light rare earth polyhydride superconductors

Exploring Potential Molecular Platforms for Quantum Technology

In recent years, there has been significant progress in the field of quantum information processing and quantum sensing. Researchers have been actively exploring new quantum systems that possess high accuracy, scalability, and compatibility with other systems. The focus of this thesis is to examine various molecular systems that hold promise for quantum sensing and information processing applications.We report a ferrocene-supported ytterbium based complex ((thiolfan)YbCl(THF), thiolfan = 1,1'-bis(2,4-di-tert-butyl-6-thiomethylenephenoxy)ferrocene) that exhibits an isolated ultranarrow absorption linewidth in solution at room temperature with a full width at half maximum (FWHM) of (151 $\pm$ 1) GHz. A detailed absorption spectroscopy analysis from room temperature (RT) to 5 K and emission spectroscopy allow us to assign the narrow near infrared (NIR) transitions to atom-centered \textit{f-f} transitions. Zeeman spectroscopy and electron paramagnetic resonance measurement help us to determine the dominant quantum numbers and Land\'e g-factors of the ground and excited states. A combination of density functional theory and multireference methods match experimental transition energies and oscillator strengths, providing insights into the role of spin-orbit coupling and asymmetric ligand field in enhancing absorption and pointing toward molecular design principles that create well-protected yet observable electronic transitions in lanthanide (Ln) complexes.We demonstrate that the ultranarrow linewidth of this system allows for magnetic field imaging and magnetic field sensing down to Earth scale, which we term an "atom-like molecular sensor" (ALMS). Furthermore, by optically depleting some population, we are able to selectively address the burned spectral hole with a FHWM of 99 kHz, paving the way for optical state preparation and readout of ground state coherence in this liquid molecular system.In addition, we also describe our efforts in building surface-based molecular systems for quantum information and we find that the sensitivity is limited by scatters from the substrate.Overall, our results suggest that molecular systems like ALMS may have great potential for quantum sensing and information applications

Recompensation of Decompensated Hepatitis B Cirrhosis: Current Status and Challenges

Liver-function decompensation or hepatocellular carcinoma (HCC) gradually appears after chronic hepatitis B progresses to cirrhosis. Effective antiviral treatment can significantly improve the long-term prognosis of decompensated patients, and some patients present recompensation of decompensated hepatitis B cirrhosis. At present, there are limited research data on the recompensation of decompensated hepatitis B cirrhosis. There is still controversy regarding the evaluation time, evaluation indicators, influencing factors, and long-term prognosis of recompensation

Mitogen-Activated Protein Kinase and Substrate Identification in Plant Growth and Development

Mitogen-activated protein kinases (MAPKs) form tightly controlled signaling cascades that play essential roles in plant growth, development, and defense response. However, the molecular mechanisms underlying MAPK cascades are still very elusive, largely because of our poor understanding of how they relay the signals. The MAPK cascade is composed of MAPK, MAPKK, and MAPKKK. They transfer signals through the phosphorylation of MAPKKK, MAPKK, and MAPK in turn. MAPKs are organized into a complex network for efficient transmission of specific stimuli. This review summarizes the research progress in recent years on the classification and functions of MAPK cascades under various conditions in plants, especially the research status and general methods available for identifying MAPK substrates, and provides suggestions for future research directions

Evolution of the <i>WRKY66</i> Gene Family and Its Mutations Generated by the CRISPR/Cas9 System Increase the Sensitivity to Salt Stress in <i>Arabidopsis</i>

Group Ⅲ WRKY transcription factors (TFs) play pivotal roles in responding to the diverse abiotic stress and secondary metabolism of plants. However, the evolution and function of WRKY66 remains unclear. Here, WRKY66 homologs were traced back to the origin of terrestrial plants and found to have been subjected to both motifs’ gain and loss, and purifying selection. A phylogenetic analysis showed that 145 WRKY66 genes could be divided into three main clades (Clade A–C). The substitution rate tests indicated that the WRKY66 lineage was significantly different from others. A sequence analysis displayed that the WRKY66 homologs had conserved WRKY and C2HC motifs with higher proportions of crucial amino acid residues in the average abundance. The AtWRKY66 is a nuclear protein, salt- and ABA- inducible transcription activator. Simultaneously, under salt stress and ABA treatments, the superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities, as well as the seed germination rates of Atwrky66-knockdown plants generated by the clustered, regularly interspaced, short palindromic repeats/CRISPR-associated 9 (CRISPR/Cas9) system, were all lower than those of wild type (WT) plants, but the relative electrolyte leakage (REL) was higher, indicating the increased sensitivities of the knockdown plants to the salt stress and ABA treatments. Moreover, RNA-seq and qRT-PCR analyses revealed that several regulatory genes in the ABA-mediated signaling pathway involved in stress response of the knockdown plants were significantly regulated, being evidenced by the more moderate expressions of the genes. Therefore, the AtWRKY66 likely acts as a positive regulator in the salt stress response, which may be involved in an ABA-mediated signaling pathway