100 research outputs found
Functionalized Bismuth Films: Giant Gap Quantum Spin Hall and Valley-Polarized Quantum Anomalous Hall States
The search for new large band gap quantum spin Hall (QSH) and quantum
anomalous Hall (QAH) insulators is critical for their realistic applications at
room temperature. Here we predict, based on first principles calculations, that
the band gap of QSH and QAH states can be as large as 1.01 eV and 0.35 eV in an
H-decorated Bi(111) film. The origin of this giant band gap lies both in the
large spin-orbit interaction of Bi and the H-mediated exceptional electronic
and structural properties. Moreover, we find that the QAH state also possesses
the properties of quantum valley Hall state, thus intrinsically realising the
so-called valley-polarized QAH effect. We further investigate the realization
of large gap QSH and QAH states in an H-decorated Bi(\={1}10) film and
X-decorated (X=F, Cl, Br, and I) Bi(111) films.Comment: submitted to Physical Reveiw Letters on 25th of September 201
Mixed topological semimetals driven by orbital complexity in two-dimensional ferromagnets
The concepts of Weyl fermions and topological semimetals emerging in
three-dimensional momentum space are extensively explored owing to the vast
variety of exotic properties that they give rise to. On the other hand, very
little is known about semimetallic states emerging in two-dimensional magnetic
materials, which present the foundation for both present and future information
technology. Here, we demonstrate that including the magnetization direction
into the topological analysis allows for a natural classification of
topological semimetallic states that manifest in two-dimensional ferromagnets
as a result of the interplay between spin-orbit and exchange interactions. We
explore the emergence and stability of such mixed topological semimetals in
realistic materials, and point out the perspectives of mixed topological states
for current-induced orbital magnetism and current-induced domain wall motion.
Our findings pave the way to understanding, engineering and utilizing
topological semimetallic states in two-dimensional spin-orbit ferromagnets
Autonomous Voltage Security Regions to Prevent Cascading Trip Faults in Wind Turbine Generators
Identification of Changes in Wheat (Triticum aestivum L.) Seeds Proteome in Response to Anti–trx s Gene
BACKGROUND: Thioredoxin h (trx h) is closely related to germination of cereal seeds. The cDNA sequences of the thioredoxin s (trx s) gene from Phalaris coerulescens and the thioredoxin h (trx h) gene from wheat are highly homologous, and their expression products have similar biological functions. Transgenic wheat had been formed after the antisense trx s was transferred into wheat, and it had been certified that the expression of trx h decreased in transgenic wheat, and transgenic wheat has high resistance to pre-harvest sprouting. METHODOLOGY/PRINCIPAL FINDINGS: Through analyzing the differential proteome of wheat seeds between transgenic wheat and wild type wheat, the mechanism of transgenic wheat seeds having high resistance to pre-harvest sprouting was studied in the present work. There were 36 differential proteins which had been identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS). All these differential proteins are involved in regulation of carbohydrates, esters, nucleic acid, proteins and energy metabolism, and biological stress. The quantitative real time PCR results of some differential proteins, such as trx h, heat shock protein 70, α-amylase, β-amylase, glucose-6-phosphate isomerase, 14-3-3 protein, S3-RNase, glyceraldehyde-3-phosphate dehydrogenase, and WRKY transcription factor 6, represented good correlation between transcripts and proteins. The biological functions of many differential proteins are consistent with the proposed role of trx h in wheat seeds. CONCLUSIONS/SIGNIFICANCE: A possible model for the role of trx h in wheat seeds germination was proposed in this paper. These results will not only play an important role in clarifying the mechanism that transgenic wheat has high resistance to pre-harvest sprouting, but also provide further evidence for the role of trx h in germination of wheat seeds
COMPATIBILITY EVALUATION OF BZ25-1 CRUDE OILS IN BOHAI BAY, CHINA
ABSTRACT BZ25-1 oilfield is located in the southeast of Bohai bay which geographically lies between 119 o 00′to 119 o 15′east longitude and 38 o 10′to 38 o 20′north latitude. It has two oil blocks, including Shahejie (SHJ) waxy oil and Minghuazhen (MHZ) heavy oil, with six wellhead platforms WHPA~WHPF and six submarine pipelines. Therein, the WHPC-WHPB and WHPB-SPM (Single Point Mooring) pipelines transport the mixture of the two produced crude oils. However, the mixing of the two oils will certainly bring out a change in their components and properties, which directly affects the safe operation of the submarine pipelines and offshore production facilities. Therefore, this paper compounds three kinds of MHZ/SHJ mixed oils with blending ratios of 1:1, 3:1 and 9:1, mainly studies how the components, rheological and thermophysical properties of the oil mixtures change with the blending ratio. The major objective of this study is to evaluate the compatibility of the two crude oils and provide a theoretical basis for the production optimization and risk elusion of the oilfield. The results of the study show that the components and properties of SHJ crude oil are quite different from those of MHZ oil, the flow behavior of SHJ oil is more sensitive to temperature. As MHZ oil in the compounds increases, the contents of asphaltene, resin, sulfur and carbon residue will increase except wax contents, their viscosities, densities and flash points will also increase, but their pour points, yield stresses, calorific values and other major thermophysical parameters will decrease. A blending ratio of 2~7:1 for MHZ to SHJ crude oil can be concluded to make the properties of the compounds meet the safe and economic requirements of the subsea pipeline and offshore facility operations and ensure the compatibility of the mixed oils. In actuality, the field operations have confirmed that the recommended blending ratio is reasonable and practicable
Improved strategy for post-traumatic hydrocephalus following decompressive craniectomy: Experience of a single center
BackgroundPatients with head trauma may develop hydrocephalus after decompressive craniectomy. Many studies have referred one-stage cranioplasty (CP) and ventriculoperitoneal shunt (VPS) was applied to treat cranial defect with post-traumatic hydrocephalus (PTH), but the safety and efficiency of the procedure remain controversial.MethodsThis is a retrospective cohort study including 70 patients of PTH following decompressive craniectomy who underwent simultaneous (50) and separated (20) procedures of cranioplasty and VPS from March 2014 to March 2021 at the authors’ institution with at least 30 days of follow-up. Patient characteristics, clinical findings, and complications were collected and analyzed.ResultsFifty patients with PTH underwent improved simultaneous procedures and 20 patients underwent staged surgeries. Among the cases, the overall complication rate was 22.86%. Complications suffered by patients who underwent one-stage procedure of CP and VPS did not differ significantly, compared with patients in the group of staged procedures (22% vs. 25%, p = 0.763). The significant difference was not observed in the two groups, regarding the complications of subdural/epidural fluid collection (4%/6% vs. 0/2%, p = 1.000/1.000), epidural hemorrhage (6% vs. 4%, p = 0.942), dysfunction of shunting system (0 vs. 2%, p = 0.286), postoperative seizure (8% vs. 4%, p = 1.000), and reoperation case (0 vs. 2%, p = 0.286). No case of subdural hemorrhage, incision/intracranial/abdominal infection, shunting system dysfunction, or reoperation was observed in the group of simultaneous procedure. Complications including subdural/epidural fluid collection, subdural hemorrhage, and incision/intracranial infection were not shown in the case series of the staged procedure group.ConclusionThe improved simultaneous procedure of cranioplasty and VPS is effective and safe to treat cranial defect and post-traumatic hydrocephalus with low risk of complications
Evaluation of Tolerability, Pharmacokinetics and Pharmacodynamics of Vicagrel, a Novel P2Y12 Antagonist, in Healthy Chinese Volunteers
Background: Vicagrel is a novel anti-platelet drug and hydrolyzed to the same intermediate as clopidogrel via esterase, instead of CYP2C19. Here we report the first clinical trial on the tolerability, pharmacokinetics and pharmacodynamics of different doses of vicagrel, and comparison with clopidogrel in healthy Chinese volunteers.Methods: This study was conducted in two parts. Study I was a dose-escalating (5–15 mg) study. For each dose, 15 participants were randomized into three groups (total n = 45); nine participants were given vicagrel, three were given clopidogrel, and three were given a placebo. Study II was conducted to assess interactions between vicagrel and aspirin in 15 healthy participants. The plasma concentrations of the metabolites of vicagrel and clopidogrel were determined using a LC-MS/MS method. Platelet aggregation was assessed using the VerifyNow-P2Y12 assay.Results: Vicagrel (5–15 mg per day) dosing for 10 days or addition of aspirin was well tolerated in healthy volunteers. The exposure of the active metabolite increased proportionally across the dose range and was higher (~10-fold) than clopidogrel. The levels of IPA dosing 75 mg clopidogrel were between the responses of 5 mg and 10 mg vicagrel. After a single loading dose of vicagrel (30 mg) and a once-daily maintenance dose (7.5 mg) for 8 days, the maximum inhibition of platelet aggregation was similar to that seen with the combined use of vicagrel and aspirin (100 mg/day).Conclusion: Oral vicagrel demonstrated a favorable safety profile and excellent anti-platelet activity, which could be a promising P2Y12 antagonist as anti-platelet drug and can be further developed in phase II/III studies, and marketing for the unmet medical needs of cardiovascular diseases. The study was registered at http://www.chictr.org.cn (ChiCTR-IIR-16009260)
A multicentre single arm phase 2 trial of neoadjuvant pyrotinib and letrozole plus dalpiciclib for triple-positive breast cancer.
peer reviewedCurrent therapies for HER2-positive breast cancer have limited efficacy in patients with triple-positive breast cancer (TPBC). We conduct a multi-center single-arm phase 2 trial to test the efficacy and safety of an oral neoadjuvant therapy with pyrotinib, letrozole and dalpiciclib (a CDK4/6 inhibitor) in patients with treatment-naïve, stage II-III TPBC with a Karnofsky score of ≥70 (NCT04486911). The primary endpoint is the proportion of patients with pathological complete response (pCR) in the breast and axilla. The secondary endpoints include residual cancer burden (RCB)-0 or RCB-I, objective response rate (ORR), breast pCR (bpCR), safety and changes in molecular targets (Ki67) from baseline to surgery. Following 5 cycles of 4-week treatment, the results meet the primary endpoint with a pCR rate of 30.4% (24 of 79; 95% confidence interval (CI), 21.3-41.3). RCB-0/I is 55.7% (95% CI, 44.7-66.1). ORR is 87.4%, (95% CI, 78.1-93.2) and bpCR is 35.4% (95% CI, 25.8-46.5). The mean Ki67 expression reduces from 40.4% at baseline to 17.9% (P < 0.001) at time of surgery. The most frequent grade 3 or 4 adverse events are neutropenia, leukopenia, and diarrhoea. There is no serious adverse event- or treatment-related death. This fully oral, chemotherapy-free, triplet combined therapy has the potential to be an alternative neoadjuvant regimen for patients with TPBC
Characterization and Functional Analysis of Pyrabactin Resistance-Like Abscisic Acid Receptor Family in Rice
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