55 research outputs found
Electrical and magnetic properties of antiferromagnetic semiconductor MnSi2N4 monolayer
Two-dimensional antiferromagnetic semiconductors have triggered significant attention due to their unique physical properties and broad application. Based on first-principles calculations, a novel two-dimensional (2D) antiferromagnetic material MnSi2N4 monolayer is predicted. The calculation results show that the two-dimensional MnSi2N4 prefers an antiferromagnetic state with a small band gap of 0.26 eV. MnSi2N4 has strong antiferromagnetic coupling which can be effectively tuned under strain. Interestingly, the MnSi2N4 monolayer exhibits a half-metallic ferromagnetic properties under an external magnetic field, in which the spin-up electronic state displays a metallic property, while the spin-down electronic state exhibits a semiconducting characteristic. Therefore, 100% spin polarization can be achieved. Two-dimensional MnSi2N4 monolayer has potential application in the field of high-density information storage and spintronic devices
Quantitative characterization of the focusing process and dynamic behavior of differently sized microparticles in a spiral microchannel
Abstract In this paper, a spiral microchannel was fabricated to systematically investigate particle dynamics. The focusing process or migration behavior of different-sized particles in the outlet region was presented. Specifically, for focused microparticles, quantitative characterization and analysis of how particles migrate towards the equilibrium positions with the increase in flow rate (De = 0.31-3.36) were performed. For unfocused microparticles, the particle migration behavior and the particlefree region's formation process were characterized over a wide range of flow rates (De = 0.31-4.58), and the emergence of double particle-free regions was observed at De C 3.36. These results provide insights into the design and operation of high-throughput particle/cell filtration and separation. Furthermore, using the location markers prefabricated along with the microchannel structures, the focusing or migration dynamics of different-sized particles along the spiral microchannel was systematically explored. The particle migration length effects on focusing degree and particle-free region width were analyzed. These analyses may be valuable for the optimization of microchannel structures. In addition, this device was successfully used to efficiently filter rare particles from a large-volume sample and separate particles of two different sizes according to their focusing states
A review of Brucea javanica: metabolites, pharmacology and clinical application
This review examines advances in the metabolites, pharmacological research, and therapeutic applications of the medicinal fruit of Brucea javanica (L.) Merr. Brucea javanica (BJ) is derived from the fruit of the Brucea javanica (L.) Merr. There are nearly 200 metabolites present in BJ, and due to the diversity of its metabolites, BJ has a wide range of pharmacological effects. The traditional pharmacological effects of BJ include anti-dysentery, anti-malaria, etc. The research investigating the contemporary pharmacological impacts of BJ mainly focuses on its anti-tumor properties. In the article, the strong monomeric metabolites among these pharmacological effects were preliminarily screened. Regarding the pharmacological mechanism of action, current research has initially explored BJ’s pharmacological agent and molecular signaling pathways. However, a comprehensive system has yet to be established. BJ preparations have been utilized in clinical settings and have demonstrated effectiveness. Nevertheless, clinical research is primarily limited to observational studies, and there is a need for higher-quality research evidence to support its clinical application. There are still many difficulties and obstacles in studying BJ. However, it is indisputable that BJ is a botanical drugs with significant potential for application, and it is expected to have broader global usage
Research advances in drug therapy of endometriosis
Endometriosis is one of the most common benign gynecological disorders in reproductive-aged women. The major symptoms are chronic pelvic pain and infertility. Despite its profound impact on women’s health and quality of life, its pathogenesis has not been fully elucidated, it cannot be cured and the long-term use of drugs yields severe side effects and hinders fertility. This review aims to present the advances in pathogenesis and the newly reported lead compounds and drugs managing endometriosis. This paper investigated Genetic changes, estrogen-dependent inflammation induction, progesterone resistance, imbalance in proliferation and apoptosis, angiogenesis, lymphangiogenesis and neurogenesis, and tissue remodeling in its pathogenesis; and explored the pharmacological mechanisms, constitutive relationships, and application prospects of each compound in the text. To date, Resveratrol, Bay1316957, and bardoxifene were effective against lesions and pain in controlled animal studies. In clinical trials, Quinagolide showed no statistical difference with the placebo group; the results of phase II clinical trial of the IL-33 antibody have not been announced yet; clinical trial stage III of vilaprisan was suspended due to drug toxicity. Elagolix was approved for the treatment of endometriosis-related pain, but clinical studies of Elagolix for the pretreatment of patients with endometriosis to before In vitro fertilization treatment have not been fulfilled. The results of a clinical study of Linzagolix in patients with moderate to severe endometriosis-related pain have not been disclosed yet. Letrozole improved the fertility of patients with mild endometriosis. For endometriosis patients with infertility, oral GnRH antagonists and aromatase inhibitors are promising drugs, especially Elagolix and Letrozole
Strain mediated phase crossover in Ruddlesden Popper nickelates
Recent progress on the signatures of pressure-induced high temperature
superconductivity in Ruddlesden Popper (RP) nickelates (Lan+1NinO3n+1) has
attracted growing interest in both theoretical calculations and experimental
efforts. The fabrication of high-quality single crystalline RP nickelate thin
films is critical for possible reducing the superconducting transition pressure
and advancing applications in microelectronics in the future. In this study, we
report the observations of an active phase transition in RP nickelate films
induced by misfit strain. We found that RP nickelate films favor the perovskite
structure (n = infinite) under tensile strains, while compressive strains
stabilize the La3Ni2O7 (n = 2) phase. The selection of distinct phases is
governed by the strain dependent formation energy and electronic configuration.
In compressively strained La3Ni2O7, we experimentally determined splitting
energy is ~0.2 eV and electrons prefer to occupy in-plane orbitals. First
principles calculations unveil a robust coupling between strain effects and the
valence state of Ni ions in RP nickelates, suggesting a dual driving force for
the inevitable phase co-existence transition in RP nickelates. Our work
underscores the sensitivity of RP nickelate formation to epitaxial strain,
presenting a significant challenge in fabricating pure-phase RP nickelate
films. Therefore, special attention to stacking defects and grain boundaries
between different RP phases is essential when discussing the pressure-induced
superconductivity in RP nickelates.Comment: 29 pages, 5 figures, one supplementary material
Metal-to-insulator transition in oxide semimetals by anion doping
Oxide semimetals exhibiting both nontrivial topological characteristics stand
as exemplary parent compounds and multiple degrees of freedom, offering great
promise for the realization of novel electronic states. In this study, we
present compelling evidence of profound structural and transport phase shifts
in a recently uncovered oxide semimetal, SrNbO3, achieved through effective
in-situ anion doping. Notably, a remarkable increase in resistivity of more
than three orders of magnitude at room temperature is observed upon
nitrogen-doping. The extent of electronic modulation in SrNbO3 is strongly
correlated with the misfit strain, underscoring its phase instability to both
chemical doping and crystallographic symmetry variations. Using
first-principles calculations, we discern that elevating the level of nitrogen
doping induces an upward shift in the conductive bands of SrNbO3-dNd.
Consequently, a transition from a metallic state to an insulating state becomes
apparent as the nitrogen concentration reaches a threshold of 1/3. This
investigation sheds light on the potential of anion engineering in oxide
semimetals, offering pathways for manipulating their physical properties. These
insights hold promise for future applications that harness these materials for
tailored functionalities.Comment: 18 pages, 4 figure
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