Sensorless control in full speed domain of interior permanent magnet synchronous motor based on hybrid observer.

Aiming at the problem that an Interior Permanent Magnet Synchronous Motor (IPMSM) cannot be smoothly started in zero-low speed range and smoothly transitioned to medium-high speed range by a single observer. This paper proposes a full-speed range control algorithm based on the fusion of pulsating high-frequency injection and back electromotive force (EMF) position error information. In the low-speed range or at start-up, a square-wave high-frequency signal is injected, and the obtained high-frequency current signal is processed to obtain the rotor position error information. The phase shift due to the introduction of a filter is reduced, which improves the control bandwidth and reduces the noise. To ensure smooth switching of the observer, the observer uses a dual second-order generalized integrator module to output the angular frequency in the low-speed range. A higher-order sliding mode observer based on an inverse EMF model obtains rotor position error information at high speeds. During switching, the rotor position information is processed by a fusion strategy, and the obtained hybrid information is fed into the system to improve the stability of the motor operation. A 0.2 kW IPMSM position sensorless vector control system verifies the algorithm's accuracy.

Optimizing ABA-based chemically induced proximity for enhanced intracellular transcriptional activation and modification response to ABA.

Abscisic acid (ABA)-based chemically induced proximity (CIP) is primarily mediated by the interaction of the ABA receptor pyrabactin resistance 1-like 1 (PYL1) and the 2C-type protein phosphatase ABI1, which confers ABA-induced proximity to their fusion proteins, and offers precise temporal control of a wide array of biological processes. However, broad application of ABA-based CIP has been limited by ABA response intensity. In this study, we demonstrated that ABA-induced interaction between another ABA receptor pyrabactin resistance 1 (PYR1) and ABI1 exhibited higher ABA response intensity than that between PYL1 and ABI1 in HEK293T cells. We engineered PYR1-ABI1 and PYL1-ABI1 into ABA-induced transcriptional activation tools in mammalian cells by integration with CRISPR/dCas9 and found that the tool based on PYR1-ABI1 demonstrated better ABA response intensity than that based on PYL1-ABI1 for both exogenous and endogenous genes in mammalian cells. We further achieved ABA-induced RNA m6A modification installation and erasure by combining ABA-induced PYR1-ABI1 interaction with CRISPR/dCas13, successfully inhibiting tumor cell proliferation. We subsequently improved the interaction of PYR1-ABI1 through phage-assisted continuous evolution (PACE), successfully generating a PYR1 mutant (PYR1m) whose interaction with ABI1 exhibited a higher ABA response intensity than that of the wild-type. In addition, we tested the transcriptional activation tool based on PYRm-ABI1 and found that it also showed a higher ABA response intensity than that of the wild type. These results demonstrate that we have developed a novel ABA-based CIP and further improved upon it using PACE, providing a new approach for the modification of other CIP systems.

Prediction of postoperative complications following transanal total mesorectal excision in middle and low rectal cancer: development and internal validation of a clinical prediction model.

PURPOSE: The objective of this study is to develop a nomogram for the personalized prediction of postoperative complication risks in patients with middle and low rectal cancer who are undergoing transanal total mesorectal excision (taTME). This tool aims to assist clinicians in early identification of high-risk patients and in addressing preoperative risk factors to enhance surgical safety. METHODS: In this case-control study, 207 patients diagnosed with middle and low rectal cancer and undergoing taTME between February 2018 and November 2023 at The First Affiliated Hospital of Xiamen University were included. Independent risk factors for postoperative complications were analyzed using the Least Absolute Shrinkage and Selection Operator (LASSO) regression and multifactorial logistic regression models. A predictive nomogram was constructed using R Studio. RESULTS: Among the 207 patients, 57 (27.5%) experienced postoperative complications. The LASSO and multifactorial logistic regression analyses identified operation time (OR = 1.010, P = 0.007), smoking history (OR = 9.693, P < 0.001), anastomotic technique (OR = 0.260, P = 0.004), and ASA score (OR = 9.077, P = 0.051) as significant predictors. These factors were integrated into the nomogram. The model's accuracy was validated through receiver operating characteristic curves, calibration curves, consistency indices, and decision curve analysis. CONCLUSION: The developed nomogram, incorporating operation time, smoking history, anastomotic technique, and ASA score, effectively forecasts postoperative complication risks in taTME procedures. It is a valuable tool for clinicians to identify patients at heightened risk and initiate timely interventions, ultimately improving patient outcomes.

Third-order nonlinear Hall effect in a quantum Hall system.

In two-dimensional systems, perpendicular magnetic fields can induce a bulk band gap and chiral edge states, which gives rise to the quantum Hall effect. The quantum Hall effect is characterized by zero longitudinal resistance (Rxx) and Hall resistance (Rxy) plateaus quantized to h/(υe2) in the linear response regime, where υ is the Landau level filling factor, e is the elementary charge and h is Planck's constant. Here we explore the nonlinear response of monolayer graphene when tuned to a quantum Hall state. We observe a third-order Hall effect that exhibits a nonzero voltage plateau scaling cubically with the probe current. By contrast, the third-order longitudinal voltage remains zero. The magnitude of the third-order response is insensitive to variations in magnetic field (down to ~5 T) and in temperature (up to ~60 K). Moreover, the third-order response emerges in graphene devices with a variety of geometries, different substrates and stacking configurations. We term the effect third-order nonlinear response of the quantum Hall state and propose that electron-electron interaction between the quantum Hall edge states is the origin of the nonlinear response of the quantum Hall state.

Construction of blackberry polysaccharide nano-selenium particles: Structure features and regulation effects of glucose/lipid metabolism in HepG2 cells.

In this study, blackberry polysaccharide-selenium nanoparticles (BBP-24-3Se) were first prepared via Na2SeO3/Vc redox reaction, followed by coating with red blood cell membrane (RBC) to form core-shell structure polysaccharide-selenium nanoparticles (RBC@BBP-24-3Se). The particle size of BBP-24-3Se (167.1 nm) was increased to 239.8 nm (RBC@BBP-24-3Se) with an obvious core-shell structure after coating with RBC. FT-IR and XPS results indicated that the interaction between BBP-24-3 and SeNPs formed a new C-O···Se bond with valence state of Se0. Bioassays indicated that RBC coating markedly enhanced both the biocompatibility and bioabsorbability of RBC@BBP-24-3Se, and the absorption rate of RBC@BBP-24-3Se in HepG2 cells was 4.99 times higher than that of BBP-24-3Se at a concentration of 10 µg/mL. Compared with BBP-24-3Se, RBC@BBP-24-3Se possessed significantly heightened protective efficacy against oxidative damage and better regulation of glucose/lipid metabolism disorder induced by palmitic acid in HepG2 cells. Mechanistic studies demonstrated that RBC@BBP-24-3Se could effectively improve PI3K/AKT signaling pathway to promote glucose metabolism, inhibit the expression of lipid synthesis genes and up-regulate the expression of lipid-decomposing genes through AMPK signaling pathway to improve lipid metabolism. These results provided a theoretical basis for developing a new type of selenium supplement for the treatment of insulin resistance.

Synthesis of Asp-based lactam cyclic peptides using an amide-bonded diaminodiacid to prevent aspartimide formation.

Asp-based lactam cyclic peptides are considered promising drug candidates. However, using Fmoc solid-phase peptide synthesis (Fmoc-SPPS) for these peptides also causes aspartimide formation, resulting in low yields or even failure to obtain the target peptides. Here, we developed a diaminodiacid containing an amide bond as a ß-carboxyl-protecting group for Asp to avoid aspartimide formation. The practicality of this diaminodiacid has been illustrated by the synthesis of lactam cyclic peptide cyclo[Lys9,Asp13] KIIIA7-14 and 1Y.

Isolating Antipathogenic Fungal Coumarins from Coriaria nepalensis and Determining Their Primary Mechanism In Vitro.

Through bioassay-guided isolation, eight undescribed coumarins (1-8), along with six reported coumarins (9-14), were obtained from Coriaria nepalensis. The new structures were determined by using IR, UV, NMR, HRESIMS, and ECD calculations. The results of the biological activity assays showed that compound 9 exhibited broad spectrum antifungal activities against all tested fungi in vitro and a significant inhibitory effect on Phytophthora nicotianae with an EC50 value of 3.00 µg/mL. Notably, compound 9 demonstrated greater curative and protective effects against tobacco balack shank than those of osthol in vivo. Thus, 9 was structurally modified to obtain new promising antifungal agents, and the novel derivatives (17b, 17j, and 17k) exhibited better effects on Sclerotinia sclerotiorum than did lead compound 9. Preliminary mechanistic exploration illustrated that 9 could enhance cell membrane permeability, destroy the morphology and ultrastructure of cells, and reduce the exopolysaccharide content of P. nicotianae mycelia. Furthermore, the cytotoxicity results revealed that compound 9 exhibited relatively low cytotoxicity against HEK293 cell lines with an inhibition rate of 33.54% at 30 µg/mL. This research is promising for the discovery of new fungicides from natural coumarins with satisfactory ecological compatibility.

Highly anisotropic spin transport in ultrathin black phosphorus.

In anisotropic crystals, the direction-dependent effective mass of carriers can have a profound impact on spin transport dynamics. The puckered crystal structure of black phosphorus leads to direction-dependent charge transport and optical response, suggesting that it is an ideal system for studying anisotropic spin transport. To this end, we fabricate and characterize high-mobility encapsulated ultrathin black-phosphorus-based spin valves in a four-terminal geometry. Our measurements show that in-plane spin lifetimes are strongly gate tunable and exceed one nanosecond. Through high out-of-plane magnetic fields, we observe a fivefold enhancement in the out-of-plane spin signal case compared to in-plane and estimate a colossal spin-lifetime anisotropy of ∼6. This finding is further confirmed by oblique Hanle measurements. Additionally, we estimate an in-plane spin-lifetime anisotropy ratio of up to 1.8. Our observation of strongly anisotropic spin transport along three orthogonal axes in this pristine material could be exploited to realize directionally tunable spin transport.

Four new pregnane C21 steroids isolated from the roots of Cynanchum auriculatum.

Four new steroids cynansteroid G-I (1-3) and cynansteroid K (4), a new natural product 5,6-deacidizingcaudatin (5), and a known compound glycocaudatin (6), were isolated from the roots of Cynanchum auriculatum. The structures of new compounds were identified by comprehensive spectroscopic analyses, including NMR, HRESI-MS, ECD, UV, and IR spectral data. The cytotoxic activities of all the isolates against two human tumour cell lines (COLO-205 and BGC-823) were screened, unfortunately, which were weaker than positive control.

Synthesis and Antifungal Activity of 2-(2-Benzoxazolyl)-1-arylethanone and 2-(2-Benzoxazolyl)-1-alkylethanone Derivatives.

To discover more effective antifungal candidates, 33 benzoxazole derivatives, were designed, synthesized, and evaluated for their antifungal activity against seven phytopathogenic fungi by the mycelium growth rate method. Among 33 benzoxazole derivatives had thirteen derivatives no reported, and new derivatives C17 exhibited good inhibitory activity against Phomopsis sp. with EC50 values of 3.26 µM. Structure-activity relationship (SAR) of these derivatives analysis indicated that the substituent played a key role in antifungal activity in ortho-, meta- and para- substituted acetophenones. The preliminary mechanistic exploration demonstrated that C17 might exert its antifungal activity by targeting the mycelia cell membrane, which was verified by the observed changes in mycelial morphology, the formation of extracellular polysaccharides, cellular contents, cell membrane permeability and integrity, among other effects. Furthermore, C17 had potent curative effect against Phomopsis sp. in vivo, which indicated that C17 may be as a novelty potent antifungal agent.

Activatable fluorescent probes for imaging and diagnosis of rheumatoid arthritis.

Rheumatoid arthritis (RA) is a systemic autoimmune disease that is primarily manifested as synovitis and polyarticular opacity and typically leads to serious joint damage and irreversible disability, thus adversely affecting locomotion ability and life quality. Consequently, good prognosis heavily relies on the early diagnosis and effective therapeutic monitoring of RA. Activatable fluorescent probes play vital roles in the detection and imaging of biomarkers for disease diagnosis and in vivo imaging. Herein, we review the fluorescent probes developed for the detection and imaging of RA biomarkers, namely reactive oxygen/nitrogen species (hypochlorous acid, peroxynitrite, hydroxyl radical, nitroxyl), pH, and cysteine, and address the related challenges and prospects to inspire the design of novel fluorescent probes and the improvement of their performance in RA studies.

Discovering the processes of undergraduate hospitality students' acceptance of facebook teaching interventions.

Technology drives innovation and reform in hospitality education, and Facebook has become a popular educational tool to facilitate students' classroom interactions. Understanding hospitality students' attitudes toward Facebook teaching interventions is important. Based on a survey of 289 undergraduate hospitality students, first, we expand the scope of the technology acceptance model (TAM) in this study, which integrates the two factors of social interaction and information exchange into the research structure. Second, this study also proposes a new moderated mediation model to account for the internal mechanism underlying Taiwanese undergraduate hospitality students' acceptance of Facebook teaching interventions in terms of perceived usefulness and ease of use. We illuminate the foundation of the application of Facebook media technology to teaching in hospitality higher education. The theoretical contributions and educational implications of this research are also discussed.

Synthesis and Antifungal Activity of Curcumol Derivatives.

To discover novel and effective antifungal candidates, a series of new curcumol derivatives were designed, synthesized, and evaluated their antifungal activity against five phytopathogenic fungi by the mycelium growth rate method. Derivatives c4, c22 and c23 exhibited excellent antifungal activity against Phomopsis sp. with EC50 values of 3.06, 3.07, and 3.16 µM, respectively. Specifically, compound c4 exhibited the strongest antifungal activity against Phomopsis sp., which was 44 times that of pyrimethanil (EC50 =134.37 µM). The results of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicated that compound c4 could cause cell senescence and death of Phomopsis sp. by changing the normal hyphal morphology and disrupting the normal metabolism of hyphal cells. Moreover, compound c4 showed excellent curative effect against Phomopsis sp. on kiwifruit. These findings confirmed that compound c4 has great potential as a potent antifungal agent.

Integrating big data and marketing concepts into tourism, hospitality operations and strategy development.

Big data (BD) research articles are on new issues, this study sought to fill the knowledge gap of linkage the relationships between big data and marketing strategy with comprehensive viewpoints across different research fields in tourism and hospitality literatures. Content analysis was conducted to gather materials from the particular studies. For each study, the content analysis included the title, abstract, journal, type of sample, exploration design, statistical and analytical techniques, data collection process and keywords was also conducted to confirm the main results of the criteria. The research shows that big data adds value to marketing strategies by using social media to collect information from consumers, which is complemented with appropriate evidence relevant to predicting their needs and behaviors.

Self-cooling water disinfection reactor with ultraviolet-C light-emitting diodes.

The use of ultraviolet-C (UV-C) light-emitting diodes (LEDs) as a water sterilization light source poses a serious challenge in heat dissipation. High junction temperatures reduce the radiant power and lifespan of UV-C LEDs. In this study, a novel self-cooling water disinfection reactor was developed to dissipate Joule heat from UV-C LEDs. The advantage of the self-cooling design is that cooling can be achieved without requiring additional power consumption and cooling liquid. The effects of the water flow rate and driving current of UV-C LEDs on the sterilization of Escherichia coli were investigated for a traditional flow-through reactor and a reactor with self-cooling. The experimental results indicated that an increase in driving current resulted in a considerable increase in the LED temperature of the flow-through reactor but only a marginal increase in the LED temperature of the self-cooling reactor. Under a driving current of 150 mA, the LED temperature of the self-cooling reactor was 55.5°C less than that of the flow-through reactor. The time required by the self-cooling reactor to reach the steady state decreased as the water flow rate increased. Under a flow rate of 100 mL/min, the self-cooling reactor reached the steady state within 62 and 70 s when the driving current was 100 and 150 mA, respectively. Moreover, the average irradiance and inactivation values of the self-cooling reactor were up to 16.5% and 26.0% higher than those of the flow-through reactor, respectively.

Quinoline Alkaloids from the Roots of Orixa japonica with the Anti-Pathogenic Fungi Activities.

A new quinoline alkaloid, 5-hydroxy-6-methoxy-N-methyl-2-phenylquinoline-4-one (1), and seventeen known quinoline alkaloids (2-18) were isolated from the roots of Orixa japonica. The structure of 1 was determined by analysis of spectroscopic data. Among them, compounds 2, 3, and 13 were isolated from this plant for the first time. All isolates were screened for the anti-pathogenic fungi activities, including Rhizoctonia solani, Magnaporthe oryzae, and Phomopsis sp. The results showed that five compounds (4, 8, 10, 11, and 12) exhibited significant anti-pathogenic fungi effects at 50.0 µg/mL. In special, compound 10 exhibited the best antifungal activities toward R. solani and M. oryzae with the IC50 values of 37.86 and 44.72 µM, respectively, better than that of the positive control, hymexazol (IC50 121.21 and 1518.18 µM, respectively). Moreover, eleven new quinoline alkaloids derivatives (12a-12k) were designed and synthesized to investigate the structure-activity relationships (SARs). The SARs analysis indicated that the furo[2,3-b]quinoline skeleton and the methoxy at C-7 (compounds 8, 11, and 12) played a key role for improving the antifungal activities.

[Research progress of risk factors of adjacent segment degeneration after anterior cervical discectomy and fusion].

Anterior cervical discectomy and fusion (ACDF) has achieved good clinical results since it was used in clinic, and is considered as the gold standard for the treatment of cervical spondylosis. However, more and more attention has been paid to adjacent segment degeneration(ASDeg) after fusion, and the debate about its pathogenesis is mainly focused on the bio-machanical stress changes of adjacent segments caused by fusion and the result of the natural aging process. The occurrence of ASDeg after fusion seriously affect the med-and long-term outcome of surgery, and some patients even need secondary surgery. In order to reduce or even avoid the occurrence of ASDeg, many new techniques have emerged in clinic, such as artificial disc replacement with preservation of motor segments, emerging cell transplantation technology and so on, but the clinical effect still needs to be confirmed by a large number of studies. Therefore, finding the risk factors of ASDeg after fusion is of great significance for fusion surgery on the clinical work. At present, there is still no unified overview of the research on the risk factors of ASDeg. This article will review the research progress and corresponding countermeasures of the risk factors of ASDeg after ACDF, in order to guide the clinical application.

Thermosensitive hydrogel microneedles for controlled transdermal drug delivery.

By using the prominent merit of poly(N-isopropylacrylamide) (PNIPAm) that can reversibly switch from a linear state to a coiled state with the change in temperature, in this work, gelatin was grafted with carboxylic end-capped PNIPAm as the matrix material to fabricate a physical entanglement crosslinked hydrogel microneedles (MNs) patch that can control drug release after application on the skin. The crystallization of the drug during the fabrication process of MNs was decreased due to the thermo-reversible sol-gel transition of the matrix materials. In addition, to increase the mechanical strength of the MNs and to decrease the application time, the gelatin-g-PNIPAm (GP) MNs patch was mounted onto solid MNs to fabricate a rapidly separating MNs system (RS-GP-MNs). The combination of the rapidly separating technique and the thermosensitive hydrogel provides the combined ability to efficiently deliver drug-loaded MNs into the skin within few seconds and to control drug release within the skin. Through a series of tests, we found that RS-GP-MNs showed suitable lower critical solution temperature and adequate crosslinking speed for practical application. The hypoglycemic effect in diabetic mice was characteristically controlled by insulin release through RS-GP-MNs as compared to the MNs made from unmodified gelatin. The proposed RS-GP-MNs system is potentially applicable to various hydrophilic small molecular and peptide medicines that require frequent dosing, thus providing an effective, noninvasive, and painless administration method with minimal safety concerns. STATEMENT OF SIGNIFICANCE: 1. Hydrogel microneedles that can be reversibly triggered and controllably release drugs at body temperature were fabricated. 2. Hydrogel microneedles prepared from gelatin-g-PNIPAm can avoid the use of a molecular crosslinker that is toxic and difficult to be completely removed. 3. Gelatin-g-PNIPAm with thermosensitive property showed appropriate molecular interactions with the drug and slowed down the crystallization speed of the drug in the solution.

Amyloid-templated polydopamine nanofibers for catecholic immobilization of catalytic noble metal nanoparticles.

Dopamine molecules were oxidized and self-polymerized into nanofibers via a template of lysozyme amyloid nanofibrils. The catechol groups adsorbed noble metal ions on the surface of the PDA nanofibers and in situ reduced them into metallic nanoparticles with excellent catalytic activities. This study will not only pave a green way for fabricating 1D nanostructures via biological templates, but also provide a unique opportunity for in situ preparation and immobilization of noble metal nanocatalysts.

Three New Pregnanes Isolated from the Cynanchum auriculatum.

Three new compounds named cynansteroid A (1), cynansteroid B (2) and cynansteroid C (3), together with nine known C21 -steroidal pregnane sapogenins (4-12) were isolated from the hydrolytic extract of the roots of Cynanchum auriculatum. The structures of cynansteroid A-C (1-3) were ascertained via the detailed analysis of the HR-ESI-MS, 1D and 2D NMR, and the calculated and experimental ECD data of cynansteroid B (2). Compound 11 displayed moderate inhibitory activity toward Verticillium dahliae Kleb (IC50 =37.15 µM), furthermore, compounds 11 and 12 showed significant inhibitory activity against Phomopsis sp. (IC50 =16.49 µM and 17.62 µM, respectively).