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1.
Nature ; 588(7838): 419-423, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33328665

RESUMO

A quantum anomalous Hall (QAH) state is a two-dimensional topological insulating state that has a quantized Hall resistance of h/(Ce2) and vanishing longitudinal resistance under zero magnetic field (where h is the Planck constant, e is the elementary charge, and the Chern number C is an integer)1,2. The QAH effect has been realized in magnetic topological insulators3-9 and magic-angle twisted bilayer graphene10,11. However, the QAH effect at zero magnetic field has so far been realized only for C = 1. Here we realize a well quantized QAH effect with tunable Chern number (up to C = 5) in multilayer structures consisting of alternating magnetic and undoped topological insulator layers, fabricated using molecular beam epitaxy. The Chern number of these QAH insulators is determined by the number of undoped topological insulator layers in the multilayer structure. Moreover, we demonstrate that the Chern number of a given multilayer structure can be tuned by varying either the magnetic doping concentration in the magnetic topological insulator layers or the thickness of the interior magnetic topological insulator layer. We develop a theoretical model to explain our experimental observations and establish phase diagrams for QAH insulators with high, tunable Chern number. The realization of such insulators facilitates the application of dissipationless chiral edge currents in energy-efficient electronic devices, and opens up opportunities for developing multi-channel quantum computing and higher-capacity chiral circuit interconnects.

2.
Nat Mater ; 23(1): 58-64, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37857889

RESUMO

A quantum anomalous Hall (QAH) insulator is a topological phase in which the interior is insulating but electrical current flows along the edges of the sample in either a clockwise or counterclockwise direction, as dictated by the spontaneous magnetization orientation. Such a chiral edge current eliminates any backscattering, giving rise to quantized Hall resistance and zero longitudinal resistance. Here we fabricate mesoscopic QAH sandwich Hall bar devices and succeed in switching the edge current chirality through thermally assisted spin-orbit torque (SOT). The well-quantized QAH states before and after SOT switching with opposite edge current chiralities are demonstrated through four- and three-terminal measurements. We show that the SOT responsible for magnetization switching can be generated by both surface and bulk carriers. Our results further our understanding of the interplay between magnetism and topological states and usher in an easy and instantaneous method to manipulate the QAH state.

3.
Nano Lett ; 24(23): 6974-6980, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38829211

RESUMO

The plateau phase transition in quantum anomalous Hall (QAH) insulators corresponds to a quantum state wherein a single magnetic domain gives way to multiple domains and then reconverges back to a single magnetic domain. The layer structure of the sample provides an external knob for adjusting the Chern number C of the QAH insulators. Here, we employ molecular beam epitaxy to grow magnetic topological insulator multilayers and realize the magnetic field-driven plateau phase transition between two QAH states with odd Chern number change ΔC. We find that critical exponents extracted for the plateau phase transitions with ΔC = 1 and ΔC = 3 in QAH insulators are nearly identical. We construct a four-layer Chalker-Coddington network model to understand the consistent critical exponents for the plateau phase transitions with ΔC = 1 and ΔC = 3. This work will motivate further investigations into the critical behaviors of plateau phase transitions with different ΔC in QAH insulators.

4.
Nano Lett ; 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38885199

RESUMO

The interface of two materials can harbor unexpected emergent phenomena. One example is interface-induced superconductivity. In this work, we employ molecular beam epitaxy to grow a series of heterostructures formed by stacking together two nonsuperconducting antiferromagnetic materials, an intrinsic antiferromagnetic topological insulator MnBi2Te4 and an antiferromagnetic iron chalcogenide FeTe. Our electrical transport measurements reveal interface-induced superconductivity in these heterostructures. By performing scanning tunneling microscopy and spectroscopy measurements, we observe a proximity-induced superconducting gap on the top surface of the MnBi2Te4 layer, confirming the coexistence of superconductivity and antiferromagnetism in the MnBi2Te4 layer. Our findings will advance the fundamental inquiries into the topological superconducting phase in hybrid devices and provide a promising platform for the exploration of chiral Majorana physics in MnBi2Te4-based heterostructures.

5.
Nano Lett ; 23(7): 2483-2489, 2023 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-36930727

RESUMO

To date, the quantum anomalous Hall effect has been realized in chromium (Cr)- and/or vanadium(V)-doped topological insulator (Bi,Sb)2Te3 thin films. In this work, we use molecular beam epitaxy to synthesize both V- and Cr-doped Bi2Te3 thin films with controlled dopant concentration. By performing magneto-transport measurements, we find that both systems show an unusual yet similar ferromagnetic response with respect to magnetic dopant concentration; specifically the Curie temperature does not increase monotonically but shows a local maximum at a critical dopant concentration. We attribute this unusual ferromagnetic response observed in Cr/V-doped Bi2Te3 thin films to the dopant-concentration-induced magnetic exchange interaction, which displays evolution from van Vleck-type ferromagnetism in a nontrivial magnetic topological insulator to Ruderman-Kittel-Kasuya-Yosida (RKKY)-type ferromagnetism in a trivial diluted magnetic semiconductor. Our work provides insights into the ferromagnetic properties of magnetically doped topological insulator thin films and facilitates the pursuit of high-temperature quantum anomalous Hall effect.

6.
Nano Lett ; 23(3): 1093-1099, 2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36715442

RESUMO

The quantum anomalous Hall (QAH) insulator carries dissipation-free chiral edge current and thus provides a unique opportunity to develop energy-efficient transformative information technology. Despite promising advances, the QAH insulator has thus far eluded any practical applications. In addition to its low working temperature, the QAH state in magnetically doped topological insulators usually deteriorates with time in ambient conditions. In this work, we store three QAH devices with similar initial properties in different environments. The QAH device without a protection layer in air shows clear degradation and becomes hole-doped. The QAH device kept in an argon glovebox without a protection layer shows no measurable degradation after 560 h, and the device protected by a 3 nm AlOx protection layer in air shows minimal degradation with stable QAH properties. Our work shows a route to preserve the dissipation-free chiral edge state in QAH devices for potential applications in quantum information technology.

7.
Nat Mater ; 21(12): 1366-1372, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36302957

RESUMO

A topological insulator (TI) interfaced with an s-wave superconductor has been predicted to host topological superconductivity. Although the growth of epitaxial TI films on s-wave superconductors has been achieved by molecular-beam epitaxy, it remains an outstanding challenge for synthesizing atomically thin TI/superconductor heterostructures, which are critical for engineering the topological superconducting phase. Here we used molecular-beam epitaxy to grow Bi2Se3 films with a controlled thickness on monolayer NbSe2 and performed in situ angle-resolved photoemission spectroscopy and ex situ magnetotransport measurements on these heterostructures. We found that the emergence of Rashba-type bulk quantum-well bands and spin-non-degenerate surface states coincides with a marked suppression of the in-plane upper critical magnetic field of the superconductivity in Bi2Se3/monolayer NbSe2 heterostructures. This is a signature of a crossover from Ising- to Rashba-type superconducting pairings, induced by altering the Bi2Se3 film thickness. Our work opens a route for exploring a robust topological superconducting phase in TI/Ising superconductor heterostructures.

8.
Phys Rev Lett ; 130(8): 086201, 2023 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-36898119

RESUMO

In quantum anomalous Hall (QAH) insulators, the interior is insulating but electrons can travel with zero resistance along one-dimensional (1D) conducting paths known as chiral edge channels (CECs). These CECs have been predicted to be confined to the 1D edges and exponentially decay in the two-dimensional (2D) bulk. In this Letter, we present the results of a systematic study of QAH devices fashioned in a Hall bar geometry of different widths under gate voltages. At the charge neutral point, the QAH effect persists in a Hall bar device with a width of only ∼72 nm, implying the intrinsic decaying length of CECs is less than ∼36 nm. In the electron-doped regime, we find that the Hall resistance deviates quickly from the quantized value when the sample width is less than 1 µm. Our theoretical calculations suggest that the wave function of CEC first decays exponentially and then shows a long tail due to disorder-induced bulk states. Therefore, the deviation from the quantized Hall resistance in narrow QAH samples originates from the interaction between two opposite CECs mediated by disorder-induced bulk states in QAH insulators, consistent with our experimental observations.

9.
J Transl Med ; 20(1): 530, 2022 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-36401321

RESUMO

BACKGROUND: Liver cancer is the fifth leading cause of cancer death worldwide, but early diagnosis and treatment of liver cancer remains a clinical challenge. How to screen and diagnose liver cancer early and prolong the survival rate is still the focus of researchers. METHODS: Cell experiments were used to detect the effect of WZ35 on the colony formation ability and proliferation activity of hepatoma cells, nude mouse experiment to observe the in vivo anticancer activity and toxic side effects of WZ35; metabolomics analysis, glucose metabolism experiment and Seahorse analysis of liver cancer cells treated with WZ35; cell experiments combined with bioinformatics analysis to explore the mechanism of WZ35-mediated metabolic reprogramming to exert anticancer activity; tissue microarray and case analysis to evaluate the clinical significance of biomarkers for early diagnosis, treatment and prognosis evaluation of liver cancer. RESULTS: WZ35 inhibited the proliferation activity of various cell lines of liver cancer, and showed good therapeutic effect in nude mice model of hepatocellular carcinoma without obvious toxic and side effects; WZ35 inhibited the absorption of glucose in hepatoma cells, and the drug effect glycolysis, phosphorylation and purine metabolism are relatively seriously damaged; WZ35 mainly inhibits YAP from entering the nucleus as a transcription factor activator by activating oxidative stress in liver cancer cells, reducing the transcription of GLUT1, and finally reducing its GLUT1. Tissue microarray and case analysis showed that GLUT1 and YAP were highly expressed and correlated in liver cancer patients, and were associated with poor patient prognosis. The GLUT1-YAP risk model had a high score in predicting prognosis. CONCLUSION: The study confirms that WZ35 is a small molecule glycolysis inhibitor, and through its properties, it mediates metabolic reprogramming dominated by impaired glycolysis, oxidative phosphorylation and purine metabolism to inhibit the proliferation activity of liver cancer cells. Our findings present novel insights into the pathology of liver cancer and potential targets for new therapeutic strategies. GLUT1-YAP has important reference significance for predicting the stages of disease progression in liver cancer patients and have the potential to serve as novel biomarkers for the diagnosis and treatment of liver cancer.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Camundongos , Animais , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/metabolismo , Transportador de Glucose Tipo 1/metabolismo , Camundongos Nus , Espécies Reativas de Oxigênio/metabolismo , Linhagem Celular Tumoral , Neoplasias Hepáticas/tratamento farmacológico , Glicólise , Purinas/uso terapêutico
10.
Phys Rev Lett ; 128(21): 216801, 2022 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35687436

RESUMO

The plateau-to-plateau transition in quantum Hall effect under high magnetic fields is a celebrated quantum phase transition between two topological states. It can be achieved by either sweeping the magnetic field or tuning the carrier density. The recent realization of the quantum anomalous Hall (QAH) insulators with tunable Chern numbers introduces the channel degree of freedom to the dissipation-free chiral edge transport and makes the study of the quantum phase transition between two topological states under zero magnetic field possible. Here, we synthesized the magnetic topological insulator (TI)/TI pentalayer heterostructures with different Cr doping concentrations in the middle magnetic TI layers using molecular beam epitaxy. By performing transport measurements, we found a potential plateau phase transition between C=1 and C=2 QAH states under zero magnetic field. In tuning the transition, the Hall resistance monotonically decreases from h/e^{2} to h/2e^{2}, concurrently, the longitudinal resistance exhibits a maximum at the critical point. Our results show that the ratio between the Hall resistance and the longitudinal resistance is greater than 1 at the critical point, which indicates that the original chiral edge channel from the C=1 QAH state coexists with the dissipative bulk conduction channels. Subsequently, these bulk conduction channels appear to self-organize and form the second chiral edge channel in completing the plateau phase transition. Our study will motivate further investigations of this novel Chern number change-induced quantum phase transition and advance the development of the QAH chiral edge current-based electronic and spintronic devices.

11.
BMC Ophthalmol ; 22(1): 129, 2022 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-35305607

RESUMO

BACKGROUND: Keratoconus (KC) is a complex, non-inflammatory corneal degenerative disease. Although numerous studies have analyzed the correlation of SNP rs1324183, which located in MPDZ-NF1B gene, and KC in different populations, only few findings were repeated. In this study, to evaluate the association between rs1324183 and KC in a new independent Chinese population, we performed a replication study of the significantly associated rs1324183. METHODS: In total of 114 unrelated KC patients and 88 unrelated controls were recruited from Ningxia, China. We detected the genotypes and alleles of rs1324183 using PCR technology and Sanger sequencing and also analyzed the association between this locus and KC, its clinical parameters by statistical methods. RESULTS: The frequency of genotype AA (11, 9.6%) and genotypes containing allele A (47, 41.2%) of rs1324183 in KC were both higher than those of the control group. And genotype AA of rs1324183 conferred a higher risk of KC (OR > 1). Moreover, corneal parameter Belin/Ambrósio enhanced ectasia display final D value (BAD-D) had significant correlation (p = 0.002) with AA genotype of rs1324183 in KC. CONCLUSIONS: Our replication study indicates that the results of rs1324183 associated with KC in our population is robust and further better illustrates the significance of BAD-D as a diagnostic indicator for KC. rs1324183 should be considered as the first genetic mark of KC risk in its future diagnosis.


Assuntos
Ceratocone , Fatores de Transcrição NFI/genética , Povo Asiático/genética , Córnea , Genótipo , Humanos , Ceratocone/diagnóstico , Ceratocone/epidemiologia , Ceratocone/genética , Proteínas de Membrana/genética , Polimorfismo de Nucleotídeo Único
12.
Nano Lett ; 21(18): 7691-7698, 2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34468149

RESUMO

Recently, MnBi2Te4 has been demonstrated to be an intrinsic magnetic topological insulator and the quantum anomalous Hall (QAH) effect was observed in exfoliated MnBi2Te4 flakes. Here, we used molecular beam epitaxy (MBE) to grow MnBi2Te4 films with thickness down to 1 septuple layer (SL) and performed thickness-dependent transport measurements. We observed a nonsquare hysteresis loop in the antiferromagnetic state for films with thickness greater than 2 SL. The hysteresis loop can be separated into two AH components. We demonstrated that one AH component with the larger coercive field is from the dominant MnBi2Te4 phase, whereas the other AH component with the smaller coercive field is from the minor Mn-doped Bi2Te3 phase. The extracted AH component of the MnBi2Te4 phase shows a clear even-odd layer-dependent behavior. Our studies reveal insights on how to optimize the MBE growth conditions to improve the quality of MnBi2Te4 films.

13.
Genetica ; 146(6): 529-540, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30377874

RESUMO

Since 2007, the annual green tide disaster in the Yellow Sea has brought serious economic losses to China. There is no research on the genetic similarities of four constituent species of green tide algae at the genomic level. We previously determined the mitochondrial genomes of Ulva prolifera, Ulva linza and Ulva flexuosa. In the present work, the mitochondrial genome of another green tide (Ulva compressa) was sequenced and analyzed. With the length of 62,311 bp, it contained 29 encoding genes, 26 tRNAs and 10 open reading frames. By comparing these four mitochondrial genomes, we found that U. compressa was quite different from the other three types of Ulva species. However, there were similarities between U. prolifera and U. linza in the number, distribution and homology of open reading frames, evolutionary and codon variation of tRNA, evolutionary relationship and selection pressure of coding genes. Repetitive sequence analysis of simple sequence repeats, tandem repeat and forward repeats further supposed that they have evolved from the same origin. In addition, we directly analyzed gene homologies and translocation of four green tide algae by Mauve alignment. There were gene order rearrangements among them. With fast-evolving genomes, these four green algal mitochondria have both conservatism and variation, thus opening another window for the understanding of origin and evolution of Ulva.


Assuntos
Genoma Mitocondrial , Ulva/genética , Códon/genética , Evolução Molecular , Repetições de Microssatélites , Fases de Leitura Aberta , RNA de Transferência/genética , Homologia de Sequência do Ácido Nucleico , Ulva/classificação
14.
J Cell Biochem ; 118(2): 376-381, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27381199

RESUMO

Osteoporosis is a common problem in aged people and those with related diseases, such as inflammatory bowel diseases. Deregulation of vitamin D metabolism plays a role in the pathogenesis of osteoporosis. Micro RNA (miR) can regulate cytokine expression in cells. This study test a hypothesis that inflammatory cytokine interleukin (IL)-13 increases miR-19a to compromise cyp27b1 (a vitamin D hydroxylase) in peripheral CD14+ cells. Bone mineral density of L2-L4 was measured in 20 patients with ulcerative colitis (UC) and 20 healthy subjects. Peripheral CD14+ cells were isolated from healthy people and patients with UC. Expression of cyp27b1 by CD14+ cells was analyzed in the presence or absence of IL-13 in the culture. We observed that bone mineral density (BMD) in UC patients was significantly lower than healthy subjects. The BMD is negatively correlated with miR-19a in peripheral CD14+ cells. MiR-19a in peripheral CD14+ cell was correlated with serum IL-13 in UC patients. Expression of cyp27b1 in peripheral CD14+ cells was correlated with miR-19a and serum IL-13 in UC patients. IL-13 suppressed cyp27b1 expression in CD14+ cells. IL-13 increased expression of miR-19a in CD14+ cells. IL-13 suppresses cyp27b1 expression in peripheral CD14+ cells via up regulating miR-19a expression. J. Cell. Biochem. 118: 376-381, 2017. © 2016 Wiley Periodicals, Inc.


Assuntos
25-Hidroxivitamina D3 1-alfa-Hidroxilase/biossíntese , Densidade Óssea , Colite Ulcerativa/metabolismo , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Interleucina-13/farmacologia , Leucócitos/metabolismo , Receptores de Lipopolissacarídeos , Coluna Vertebral/metabolismo , Adulto , Colite Ulcerativa/complicações , Colite Ulcerativa/patologia , Feminino , Humanos , Leucócitos/patologia , Masculino , MicroRNAs/biossíntese , Pessoa de Meia-Idade , Osteoporose/etiologia , Osteoporose/metabolismo , Osteoporose/patologia , Coluna Vertebral/patologia
15.
BMC Complement Med Ther ; 24(1): 68, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38297301

RESUMO

BACKGROUND: Small cell lung cancer (SCLC) is the most malignant lung cancer type. Due to the high rates of metastasis and drug resistance, effective therapeutic strategies remain lacking. Tanshinone IIA (Tan IIA) has been reported to exhibit anti-tumor activity. Therefore, this study investigated the ability and underlying mechanism of Tan IIA to inhibit the metastasis and proliferation of SCLC. METHODS: H1688 and H446 cells were treated in vitro with Tan IIA (0, 1, 2 and 4 µM) or LY294002 (10 µM) for 24, 48, 72 h. H1688 and H446 cell migration was evaluated in wound healing and transwell migration assays. RNA-sequencing helped assess gene expression. BALB/c nude mice were injected with H1688 cells and treated with the Tan IIA group (10 mg/kg/day) or a control. Expression of E-cadherin, vimentin and PI3K/Akt signaling pathway proteins in tumors and H1688 was investigated by immunohistochemical analysis and western blot. RESULTS: Tan IIA inhibited H1688 and H446 cell proliferation without inducing apoptosis and suppressed H1688 and H446 cell migration. E-cadherin expression was increased, while vimentin expression was reduced after administration of Tan IIA. RNA-sequencing revealed that some genes related with the PI3K/Akt signaling pathway were altered using Tan IIA treatment. Furthermore, western blot helped detect PI3K and p-Akt expression was also reduced by Tan IIA treatment. Tan IIA inhibited tumor growth in vivo. Moreover, Tan IIA increased tumoral expression of E-cadherin accompanied by PI3K and p-Akt downregulation. CONCLUSION: Tan IIA suppresses SCLC proliferation and metastasis by inhibiting the PI3K/Akt signaling pathway, thereby highlighting the potential of Tan IIA as a new and relatively safe drug candidate to treat SCLC.


Assuntos
Abietanos , Neoplasias Pulmonares , Carcinoma de Pequenas Células do Pulmão , Camundongos , Animais , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Vimentina/metabolismo , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Regulação para Baixo , Neoplasias Pulmonares/tratamento farmacológico , Camundongos Nus , Proliferação de Células , Caderinas/farmacologia , RNA/farmacologia
16.
Sci Total Environ ; 945: 173913, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38880157

RESUMO

The globally distributed harmful algal blooms (HAB) species, Heterosigma akashiwo, has been found to exhibit ichthyotoxicity. Previous studies have shown that H. akashiwo achieves a competitive edge during bloom occurrences by inhibiting the growth of a coexisting diatom, Skeletonema costatum, through allelopathy. However, the specific allelopathic mechanisms underlying the allelopathic effects of H. akashiwo on S. costatum remain unknown. To bridge this gap, our study utilized a combination of quantitative real-time PCR and metabolomics to examine the allelopathic processes of H. akashiwo on S. costatum. Our results demonstrate that the growth of S. costatum is hindered when co-cultured with H. akashiwo (initial cell concentration, 2 × 104 cell/mL). Gene expression investigation showed a substantial reduction in the mRNA levels of cytochrome b6, ribulose bisphosphate carboxylase large chain, and silicon transporter in S. costatum when grown in co-culture conditions. Furthermore, metabolic pathway analysis suggested that the allelopathic effects of H. akashiwo disrupted several vital metabolic pathways in S. costatum, including a reduction in purine and pyrimidine metabolism and an increase in fatty acid biosynthesis. Our investigation has revealed the intricate and substantial involvement of allelopathy in the formation of H. akashiwo blooms, demonstrating the complexity of the allelopathic interaction between H. akashiwo and S. costatum. These insights also contribute significantly to our understanding of the dynamics within HAB species.

17.
Nutr Metab (Lond) ; 21(1): 39, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38943189

RESUMO

BACKGROUND: Conflicting findings regarding the impact of High protein intake during the early phase in critically ill patients have been reported. Therefore, we aimed to assess the influence of higher early protein intake on the prognosis of critically ill patients. METHODS: This randomized controlled trial involved 173 critically ill patients who stayed in the Intensive Care Unit/Emergency ICU (ICU/EICU) for at least 7 days. The Low group (n = 87) and High group (n = 86) received protein supplementation of 0.8 g/kg.d and 1.5 g/kg.d, respectively, within 1-3 days of enteral nutrition (EN) initiation, with both groups transitioning to 1.5 g/kg.d on the 4th day. The serum prealbumin (PA), blood urea nitrogen/creatinine, and rectus femoris muscle thickness and cross-sectional area of all patients was measured on the 1th, 3rd, 5th, 7th day, and the day of ICU/EICU discharge. RESULTS: Patients in both Low and High groups showed no significant differences in age, APACHE II scores, or other demographic and baseline characteristics. There were also no significant differences in the primary outcome (28-day mortality rate) and secondary outcomes (incidence rate of refeeding syndrome and EN tolerance score) between the two groups. However, the Low group exhibited a significantly higher 28-day mortality rate (HR = 2.462, 95% CI: 1.021-5.936, P = 0.045) compared to High group, as determined by Cox proportional hazards models incorporating the time factor. The High group exhibited significantly shorter durations of mechanical ventilation and ICU stay compared to the Low group. Serum PA levels were higher, and rectus femoris muscle atrophy rates were lower in the High group. Furthermore, for septic patients, high protein intake significantly reduced the 28-day mortality rate despite a small sample size (n = 34). CONCLUSIONS: Our study indicates that increasing early protein intake to 1.5 g/kg.d may be safe and help improve the nutritional status and prognosis of critically ill patients. TRIAL REGISTRATION: This study was registered with the Chinese Clinical Trial Registry (ChiCTR2000039997, https://www.chictr.org.cn/ ).

18.
Adv Mater ; 36(13): e2310249, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38118065

RESUMO

Magnetic topological states refer to a class of exotic phases in magnetic materials with the non-trivial topological property determined by magnetic spin configurations. An example of such states is the quantum anomalous Hall (QAH) state, which is a zero magnetic field manifestation of the quantum Hall effect. Current research in this direction focuses on QAH insulators with a thickness of less than 10 nm. Here, molecular beam epitaxy (MBE) is employed to synthesize magnetic TI trilayers with a thickness of up to ≈106 nm. It is found that these samples exhibit well-quantized Hall resistance and vanishing longitudinal resistance at zero magnetic field. By varying the magnetic dopants, gate voltages, temperature, and external magnetic fields, the properties of these thick QAH insulators are examined and the robustness of the 3D QAH effect is demonstrated. The realization of the well-quantized 3D QAH effect indicates that the nonchiral side surface states of the thick magnetic TI trilayers are gapped and thus do not affect the QAH quantization. The 3D QAH insulators of hundred-nanometer thickness provide a promising platform for the exploration of fundamental physics, including axion physics and image magnetic monopole, and the advancement of electronic and spintronic devices to circumvent Moore's law.

19.
Science ; 383(6683): 634-639, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38330133

RESUMO

The interface between two different materials can show unexpected quantum phenomena. In this study, we used molecular beam epitaxy to synthesize heterostructures formed by stacking together two magnetic materials, a ferromagnetic topological insulator (TI) and an antiferromagnetic iron chalcogenide (FeTe). We observed emergent interface-induced superconductivity in these heterostructures and demonstrated the co-occurrence of superconductivity, ferromagnetism, and topological band structure in the magnetic TI layer-the three essential ingredients of chiral topological superconductivity (TSC). The unusual coexistence of ferromagnetism and superconductivity is accompanied by a high upper critical magnetic field that exceeds the Pauli paramagnetic limit for conventional superconductors at low temperatures. These magnetic TI/FeTe heterostructures with robust superconductivity and atomically sharp interfaces provide an ideal wafer-scale platform for the exploration of chiral TSC and Majorana physics.

20.
Nat Commun ; 14(1): 770, 2023 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-36765068

RESUMO

One-dimensional chiral interface channels can be created at the boundary of two quantum anomalous Hall (QAH) insulators with different Chern numbers. Such a QAH junction may function as a chiral edge current distributer at zero magnetic field, but its realization remains challenging. Here, by employing an in-situ mechanical mask, we use molecular beam epitaxy to synthesize QAH insulator junctions, in which two QAH insulators with different Chern numbers are connected along a one-dimensional junction. For the junction between Chern numbers of 1 and -1, we observe quantized transport and demonstrate the appearance of the two parallel propagating chiral interface channels along the magnetic domain wall at zero magnetic field. For the junction between Chern numbers of 1 and 2, our quantized transport shows that a single chiral interface channel appears at the interface. Our work lays the foundation for the development of QAH insulator-based electronic and spintronic devices and topological chiral networks.

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