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1.
J Hand Surg Eur Vol ; : 17531934211065874, 2022 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-35001678

RESUMO

Foveal disruption of the triangular fibrocartilage complex contributes to the instability of distal radioulnar joint. We have developed an arthroscopic transosseous foveal footprint repair technique, which maximizes the contact between the disrupted triangular fibrocartilage complex and its foveal footprint for better healing by using four sutures in a divergent configuration through a 1.6-mm bone tunnel. Twelve patients with triangular fibrocartilage complex foveal injuries who had undergone this repair technique were reviewed with a mean follow-up of 53 months. All patients achieved significant improvement in the modified Mayo wrist score and the Disabilities of the Arm, Shoulder and Hand score. All patients had stable distal radioulnar joints with comparable ranges of motion and grip strengths between the operated and contralateral wrists. There was no significant difference in functional score in those who were treated more than 6 months after injury.Level of evidence: IV.

2.
Artigo em Inglês | MEDLINE | ID: mdl-35005819

RESUMO

Aqueous zinc-ion batteries (ZIBs) are promising for next-generation energy storage. However, the reported electrode materials for ZIBs are facing the shortcomings including low capacity and unsatisfactory cycling stability etc. Herein, hexaazatrinaphthalene-quione (HATNQ) is reported for aqueous ZIBs. The HATNQ electrodes delivered an ultrahigh capacity (482.5 mAh g -1 at 0.2 A g -1 ) and outstanding cyclability of >10000 cycles at 5 A g -1 . The capacity sets new record for organic cathodes in aqueous ZIBs. The high performances are ascribed to the rich C=O and C=N groups that endowed HATNQ with 2D layered supramolecular structure by multiple hydrogen bonds in plane with π-π interactions out of plane, leading to enhanced charge transfer, insolubility, and rapid ion transport for fast-charge and -discharge batteries. Moreover, the 2D supramolecular structure boosted the storage of Zn 2+ /H + , particularly the storage of Zn 2+ , due to the more favorable O···Zn···N coordination in HATNQ.

3.
Nat Commun ; 13(1): 352, 2022 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-35039502

RESUMO

Synthetic DNA is a growing alternative to electronic-based technologies in fields such as data storage, product tagging, or signal processing. Its value lies in its characteristic attributes, namely Watson-Crick base pairing, array synthesis, sequencing, toehold displacement and polymerase chain reaction (PCR) capabilities. In this review, we provide an overview of the most prevalent applications of synthetic DNA that could shape the future of information technology. We emphasize the reasons why the biomolecule can be a valuable alternative for conventional electronic-based media, and give insights on where the DNA-analog technology stands with respect to its electronic counterparts.

4.
J Asian Nat Prod Res ; : 1-7, 2022 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-35037543

RESUMO

Three new cassane-type diterpenoids, namely, (4S)-6ß,12α,19-trihydroxy-cass-13(15)-en-16,12-olide (1), cass-13(15)-en-​16,12-olide (2), and 12α-hydroxy-cass-13(15)-en-16,12-olide (3), were isolated from the seeds of Caesalpinia sinensis. The structures of 1-3 were established by extensive spectroscopic analysis, and their absolute configurations were assigned by electronic circular dichroism (ECD) calculations. The inhibitory activities against PTP1B of the isolated compounds were evaluated. The results showed that compound 2 possessed PTP1B inhibitory activity with an IC50 value of 217.45 ± 36.4 µM.

5.
Biomed Chromatogr ; : e5327, 2022 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-34994004

RESUMO

Trans-ferulic acid-4-ß-glucoside (FAG) is a monomer extracted from Radix Aconiti Lateralis Preparata, which is a potential candidate for the prevention and treatment of the cold injury. To determine the concentration FAG in rats, it is essential to develop an ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) method. The chromatographic separation was achieved by ACQUITY UPLC BEH C18 column(2.1×50mm, 1.7µm). A Xevo triple quadrupole tandem mass spectrometer was used to quantitative determination of FAG in the negative ion mode. The standard calibration curve was linear over the concentration range of 0.1-100 µg/mL and 0.0626-31.28 µg/g for rat plasma and liver tissue homogenates samples, separately. The inter-and intra-batch precision (RSD%) of the assay was ≤ 8.29% and accuracy (RE%) ranged from -7.41 to 10.99%. The matrix effect was between 92.99 and 102.39%. The oral absolute bioavailability of FAG was obtained as 1.80%. The results of tissue distribution suggested that FAG spread rarely in liver and brown adipose, which was not propitious to exert its ability to treat cold injury. In general, the above studies were significant to provide necessary information for further study.

6.
J Exp Clin Cancer Res ; 41(1): 8, 2022 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-34983615

RESUMO

BACKGROUND: Multiple myeloma (MM) is an incurable plasma cell malignancy. Although Dexamethasone (Dex) is the most widely used therapeutic drug in MM treatment, patients develop Dex resistance leading to progressive disease, demanding an urgent need to investigate the mechanisms driving Dex resistance and develop new reagents to address this problem. We propose SUMOylation as a potential mechanism regulating Dex resistance and SUMOylation inhibition can enhance Dex sensitivity in MM. METHODS: Using MM cell lines and primary MM samples from relapsing MM patients, we evaluated the effects of knockdown of SUMO E1 (SAE2) or using TAK-981, a novel and specific SUMO E1 inhibitor, on Dex sensitivity. Xenograft mouse models were generated to determine the in vivo anti-MM effects of TAK-981 as a single agent and in combination with Dex. miRNA-seq, RNA-seq and GSEA analysis were utilized for evaluating key factors mediating Dex resistance. Chromatin immunoprecipitation (ChIP) assay was performed to determine the binding occupancy of c-Myc on promoter region of miRs. RESULTS: We observed a significant negative correlation between SUMO E1 (SAE2) expression and Dex sensitivity in primary MM samples. Knockdown of SAE2 or using TAK-981 significantly enhances myeloma sensitivity to Dex in MM cell lines. Moreover, the enhanced anti-MM activity by TAK-981 and Dex combination has been validated using primary relapsing MM patient samples and xenograft mouse models. SUMOylation inhibition increased glucocorticoid receptor (GR) expression via downregulation miR-130b. Using RNA and microRNA sequencing, we identified miR-551b and miR-25 as important miRs mediating Dex resistance in MM. Overexpression of miR-551b and miR-25 caused resistance to Dex, however, knockdown of miR-551b and miR-25 significantly enhanced Dex sensitivity in MM. SAE2 knockdown or TAK-981 treatment downregulated the expression of miR-551b and miR-25, leading to induction of miR targets ZFP36, ULK1 and p27, resulting in apoptosis and autophagy. We demonstrated c-Myc as a major transcriptional activator of miR-130b, miR-551b and miR-25 and SUMOylation inhibition downregulates these miRs level by decreasing c-Myc level. CONCLUSION: Our study proves SUMOylation plays a crucial role in Dex resistance in MM and SUMOylation inhibition appears to be an attractive strategy to advance to the clinic for MM patients.

7.
Carbohydr Polym ; 278: 118970, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34973785

RESUMO

In this study, to investigate the influence of glyoxylate bearing Schiff base on bioactivity to chitosan quaternary ammonium salts, different chitosan derivatives were synthesized by ion exchange of glyoxylate bearing Schiff base with chitosan quaternary ammonium salts (TMCI and HACC). For this purpose, glyoxylate was prepared by Schiff base reaction of glyoxylic acid and amino heterocycles and it was further ionization to substitute iodide ions and chloride ions. After structural characterization by FTIR and 1H NMR, the antifungal and antioxidant activities were measured. Results indicated that glyoxylate bearing Schiff base could improve the bioactivity of TMCI and HACC obviously. Specifically, anionic TMCI with Schiff base of amino pyridines possessed best antioxidant activity >92.40% at 1.6 mg/mL against DPPH radicals. Meanwhile, they showed antifungal activity >84.88% at 1.0 mg/mL against G. cingulate. Furthermore, the cytotoxicity was evaluated, and all samples showed good cell viability >80.14% at 1000 µg/mL.

8.
Aging (Albany NY) ; 14(undefined)2022 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-35045398

RESUMO

OBJECTIVES: To study how marital status influences overall survival (OS) in patients with stage IA non-small cell lung cancer (NSCLC). And whether the result is valid in different time periods. MATERIALS AND METHODS: We retrospectively analyzed 55,207 cases of stage IA NSCLC from 1995 to 2015 in the Surveillance, Epidemiology, and End Results (SEER) database. Marital status was classified as follows: married or with unmarried/domestic partner (MR/W.P), divorced or separated (DV/SP), widowed (WD), and single (never married). Patients diagnosed in 1995-2005 and 2006-2015 were analyzed separately as groups 1 and 2, respectively, to validate the results. Within each group, age-stratified demographic, clinicopathologic features, and OS were compared among different marital statuses. RESULTS AND CONCLUSIONS: A total of 55,207 cases were included (group 1 n=20,223, group 2 n=34,984). From 1995-2005 to 2006-2015, median OS was prolonged significantly in all patients besides the DV/SP subgroup. In general, being MR/W.P was associated with the lowest relative risk of death in the study population (Group 1, HR= 0.854, 95%CI: 0.816-0.893; Group 2, HR = 0.799, 95%CI: 0.758-0.842). Meanwhile, OS of DV/SP and widowed patients was similar. In group 2, being single was associated with lower risk of death beyond 60-year-old.

9.
Commun Biol ; 5(1): 18, 2022 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-35017629

RESUMO

Fluorescence lifetime imaging microscopy (FLIM) is a powerful tool to quantify molecular compositions and study molecular states in complex cellular environment as the lifetime readings are not biased by fluorophore concentration or excitation power. However, the current methods to generate FLIM images are either computationally intensive or unreliable when the number of photons acquired at each pixel is low. Here we introduce a new deep learning-based method termed flimGANE (fluorescence lifetime imaging based on Generative Adversarial Network Estimation) that can rapidly generate accurate and high-quality FLIM images even in the photon-starved conditions. We demonstrated our model is up to 2,800 times faster than the gold standard time-domain maximum likelihood estimation (TD_MLE) and that flimGANE provides a more accurate analysis of low-photon-count histograms in barcode identification, cellular structure visualization, Förster resonance energy transfer characterization, and metabolic state analysis in live cells. With its advantages in speed and reliability, flimGANE is particularly useful in fundamental biological research and clinical applications, where high-speed analysis is critical.

10.
Biosens Bioelectron ; 200: 113930, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-34979348

RESUMO

The level of C-reactive protein (CRP) in serum is frequently used to evaluate risk of coronary heart disease, and its concentration is related to cardiovascular disease, fibrosis and inflammation, cancer, and viral infections. In this work, three novel peptides, never previously used as imprinted templates, were selected, synthesized, and employed for epitope imprinting. Various imprinting concentrations of the template and various ratios of aniline (AN) to m-aminobenzenesulfonic acid (MSAN) were used in electropolymerization to form molecularly imprinted polymers (MIPs). The imprinting template and functional monomer concentrations were optimized to maximize the electrochemical response to target peptides. The surface morphologies of peptide- and non-imprinting poly(AN-co-MSAN) were observed using a scanning electron microscope (SEM) and an atomic force microscope (AFM). Moreover, the effect of doping of MIPs with a very small percentage of an MXene (e.g. Ti2C at 0.1 wt% in the preparation solution) on the electrochemical response was also studied. Ti2C doping dramatically increased sensing range from 0.1 to 100 fg/mL to 10000 fg/mL, and electrochemical responses were amplified by a factor of approximately 1.3 within the sensing range. Finally, commercially available serum was diluted and then measured using the MXene-doped PIP-coated electrodes to estimate the accuracy compared with ELISA results.


Assuntos
Técnicas Biossensoriais , Impressão Molecular , Proteína C-Reativa , Técnicas Eletroquímicas , Peptídeos , Polímeros
11.
Cell Mol Life Sci ; 79(1): 64, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-35013841

RESUMO

Nicotinic acetylcholine receptors (nAChRs) are widespread throughout the central nervous system. Signaling through nAChRs contributes to numerous higher-order functions, including memory and cognition, as well as abnormalities such as nicotine addiction and neurodegenerative disorders. Although recent studies indicate that the PDZ-containing proteins comprising PSD-95 family co-localize with nicotinic acetylcholine receptors and mediate downstream signaling in the neurons, the mechanisms by which α7nAChRs are regulated remain unclear. Here, we show that the PDZ-LIM domain family protein PDLIM5 binds to α7nAChRs and plays a role in nicotine-induced α7nAChRs upregulation and surface expression. We find that chronic exposure to 1 µM nicotine upregulated α7, ß2-contained nAChRs and PDLIM5 in cultured hippocampal neurons, and the upregulation of α7nAChRs and PDLIM5 is increased more on the cell membrane than the cytoplasm. Interestingly, in primary hippocampal neurons, α7nAChRs and ß2nAChRs display distinct patterns of expression, with α7nAChRs colocalized more with PDLIM5. Furthermore, PDLIM5 interacts with α7nAChRs, but not ß2nAChRs in native brain neurons. Knocking down of PDLIM5 in SH-SY5Y abolishes nicotine-induced upregulation of α7nAChRs. In primary hippocampal neurons, using shRNA against PDLIM5 decreased both surface clustering of α7nAChRs and α7nAChRs-mediated currents. Proteomics analysis and isothermal titration calorimetry (ITC) results show that PDLIM5 interacts with α7nAChRs through the PDZ domain, and the interaction between PDLIM5 and α7nAChRs can be promoted by nicotine. Collectively, our data suggest a novel cellular role of PDLIM5 in the regulation of α7nAChRs, which may be relevant to plastic changes in the nervous system.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Hipocampo/metabolismo , Proteínas com Domínio LIM/metabolismo , Nicotina/farmacologia , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Comportamento Aditivo/fisiopatologia , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Células HEK293 , Hipocampo/citologia , Humanos , Proteínas com Domínio LIM/genética , Neurônios/metabolismo , Domínios Proteicos/fisiologia , Interferência de RNA , RNA Interferente Pequeno/genética , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/fisiologia , Fumar , Regulação para Cima , Receptor Nicotínico de Acetilcolina alfa7/biossíntese
12.
Biomater Sci ; 2022 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-34988569

RESUMO

Ferroptosis drugs often induce oxidative damage or block antioxidant defense due to the key mechanism of ferroptosis involved in cancer treatment, regulating the intracellular redox balance. However, these ferroptosis drugs are unstable during systemic circulation, and they lack tumor-targeting capability. Herein, we developed a stimuli-responsive and cell membrane-coated nanodrug for the simultaneous delivery of two ferroptosis drugs, an iron-chelating drug as a ROS inducer and sorafenib as an antioxidase inhibitor. The coating of the cancer cell membrane over the nanodrug can enhance the tumor-targeting capability and improve the stability in the blood circulation. In addition, the nanodrug exhibits sensitive drug release profiles in response to glutathione (GSH) and reactive oxygen species (ROS) in tumor microenvironments due to the dynamic diselenide bonds. The released iron-chelating drug and sorafenib not only produce hydroxyl radicals (˙OH) to induce ferroptosis, but also inhibit the expression of GPX4 to mitigate the ferroptosis resistance. Excitingly, the systemic administration of this biomimetic nanodrug displays superior antitumor and anti-metastatic effects in tumor-bearing mice. Our findings provide a promising therapeutic strategy for the co-delivery of ferroptosis inducers and antioxidase inhibitors to strengthen the therapeutic efficacy of ferroptosis.

13.
Medicine (Baltimore) ; 101(3): e28654, 2022 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-35060558

RESUMO

RATIONALE: Massive oronasal hemorrhage can induce shock and is life-threatening, and early endovascular treatment is the standard of care. Few studies have reported the use of endovascular treatment for acute epidural hemorrhage (AEDH). However, endovascular treatment of oronasal hemorrhage complicated by AEDH has not yet been demonstrated. Many patients with a low to moderate volume of oronasal hemorrhage complicated by AEDH choose conservative treatment but eventually undergo craniotomy due to increased intracranial hemorrhage. PATIENT CONCERNS: A 32-year-old man presented to our hospital with traumatic oronasal hemorrhage complicated by AEDH after being hit by a blunt object. DIAGNOSIS: Computerized tomography suggested progressive AEDH and multiple basilar skull fractures. Emergency cerebral angiography showed rupture of the right middle meningeal artery and a branch of the left maxillary artery causing AEDH and oronasal hemorrhage. INTERVENTIONS: The patient underwent interventional embolization to treat the ruptured intracranial vessels. OUTCOMES: After 23 days, cranial computerized tomography showed remarkable absorption of the right frontal epidural hematoma, with the patient having a Glasgow Coma Scale score of 15. LESSONS: This case provides a valuable treatment for patients with AEDH complicated with oronasal hemorrhage, early interventional embolization may be an effective treatment strategy to prevent further complications and ensure a good patient outcome.

14.
Physiol Plant ; : e13625, 2022 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-35023161

RESUMO

Cuticular lipids, including wax and cutin, protect plants against external environmental stress. The relationship between the cuticle properties and salt tolerance is not clear. In this paper, photosynthetic and physiological characteristics related to water use and cuticle permeability were assessed in the leaves of T. salsuginea under NaCl stress. The chemical composition of wax and cutin monomers, and the expression of cuticle-associated genes were also analyzed. The results showed that the net photosynthetic rate and stomatal conductance in the leaves of T. salsuginea decreased, and the water use efficiency increased with increasing NaCl concentration. Salt stress caused a significant increase in total wax, but total cutin monomers only increased under high salt. Transcriptome sequencing and lipid metabolism pathway analysis were performed on rosette leaves of T. salsuginea after 24 h of NaCl treatment. We analyzed the expression of 42 genes involved in cuticle lipid metabolism, and found that most of them exhibited higher expression levels at 0.15 mol l-1 NaCl, but lower expression levels at 0.3 mol l-1 NaCl. The expression of 12 of these genes was further detected by qRT-PCR after 1 week of NaCl treatment: most of them were up-regulated both under low and high NaCl stress. Hence, we speculate that the cuticle acts as an adaptive trait in T. salsuginea in salty environments.

15.
Spectrochim Acta A Mol Biomol Spectrosc ; 270: 120858, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-35016060

RESUMO

Ratio fluorescence has attracted much attention because of its self-calibration properties. However, it is difficult to obtain suitable fluorescent materials with well-resolved signals simultaneously under one excitation. In this work, we report a different strategy, using MIL-68(In)-NH2 as both the fluorescence element and the scattered light unit, and coupling the fluorescence and the scattered light to construct the fluorescence and scattered light ratio system. Based on the optical properties and the second-order scattering (SOS) of the material nanoparticles, the synthesized MIL-68(In)-NH2 can be used to realize the ratio detection of Hg2+. Because the scattering intensity of small particle MIL-68(In)-NH2 is weak, SOS is not obvious. When Hg2+ is introduced the coordination reaction between the amino nitrogen atoms of MIL-68(In)-NH2 and Hg2+ make the particles larger, resulting in the decrease of fluorescence and the enhancement of SOS. As a result, a novel Hg2+ ratiometric detection method is developed by using the dual signal responses of the fluorescence and scattering. Under the optimal conditions (pH = 6, reaction time 5 min, room temperature, and the maximum excitation wavelength 365 nm), the linear range of the method is 0-100 µM, and the detection limit is 5.8 nM (Ksv = 9.89 × 109 M-1). In addition, the probe is successfully used to evaluate Hg2+ in actual water samples. Compared with the traditional method of recording only the fluorescence signal, the proposed fluorescence-scattering method provides a new strategy for the design of ratiometric sensors.

16.
PLoS Negl Trop Dis ; 16(1): e0010090, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35041675

RESUMO

BACKGROUND: This research aimed to explore the association between the RIG-I-like receptor (RIG-I and MDA5 encoded by DDX58 and IFIH1, respectively) pathways and the risk or severity of hand, foot, and mouth disease caused by enterovirus 71 (EV71-HFMD). In this context, we explored the influence of gene methylation and polymorphism on EV71-HFMD. METHODOLOGY/PRINCIPAL FINDINGS: 60 healthy controls and 120 EV71-HFMD patients, including 60 mild EV71-HFMD and 60 severe EV71-HFMD patients, were enrolled. First, MiSeq was performed to explore the methylation of CpG islands in the DDX58 and IFIH1 promoter regions. Then, DDX58 and IFIH1 expression were detected in PBMCs using RT-qPCR. Finally, imLDR was used to detect DDX58 and IFIH1 single-nucleotide polymorphism (SNP) genotypes. Severe EV71-HFMD patients exhibited higher DDX58 promoter methylation levels than healthy controls and mild EV71-HFMD patients. DDX58 promoter methylation was significantly associated with severe HFMD, sex, vomiting, high fever, neutrophil abundance, and lymphocyte abundance. DDX58 expression levels were significantly lower in mild patients than in healthy controls and lower in severe patients than in mild patients. Binary logistic regression analysis revealed statistically significant differences in the genotype frequencies of DDX58 rs3739674 between the mild and severe groups. GeneMANIA revealed that 19 proteins displayed correlations with DDX58, including DHX58, HERC5, MAVS, RAI14, WRNIP1 and ISG15, and 19 proteins displayed correlations with IFIH1, including TKFC, IDE, MAVS, DHX58, NLRC5, TSPAN6, USP3 and DDX58. CONCLUSIONS/SIGNIFICANCE: DDX58 expression and promoter methylation were associated with EV71 infection progression, especially in severe EV71-HFMD patients. The effect of DDX58 in EV71-HFMD is worth further attention.

17.
18.
Biosensors (Basel) ; 12(1)2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-35049659

RESUMO

C-reactive protein (CRP) is a non-specific biomarker of inflammation and may be associated with cardiovascular disease. In recent studies, systemic inflammatory responses have also been observed in cases of coronavirus disease 2019 (COVID-19). Molecularly imprinted polymers (MIPs) have been developed to replace natural antibodies with polymeric materials that have low cost and high stability and could thus be suitable for use in a home-care system. In this work, a MIP-based electrochemical sensing system for measuring CRP was developed. Such a system can be integrated with microfluidics and electronics for lab-on-a-chip technology. MIP composition was optimized using various imprinting template (CRP peptide) concentrations. Tungsten disulfide (WS2) was doped into the MIPs. Doping not only enhances the electrochemical response accompanying the recognition of the template molecules but also raises the top of the sensing range from 1.0 pg/mL to 1.0 ng/mL of the imprinted peptide. The calibration curve of the WS2-doped peptide-imprinted polymer-coated electrodes in the extended-gate field-effect transistor platform was obtained and used for the measurement of CRP concentration in real human serum.

19.
Nanomaterials (Basel) ; 12(2)2022 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-35055295

RESUMO

Magnetic skyrmions are promising potential information carriers for future spintronic devices owing to their nanoscale size, non-volatility and high mobility. In this work, we demonstrate the controlled manipulation of skyrmion motion and its implementation in a new concept of racetrack logical device by introducing an inhomogeneous perpendicular magnetic anisotropy (PMA) via micromagnetic simulation. Here, the inhomogeneous PMA can be introduced by a capping nano-island that serves as a tunable potential barriers/well which can effectively modulate the size and shape of isolated skyrmion. Using the inhomogeneous PMA in skyrmion-based racetrack enables the manipulation of skyrmion motion behaviors, for instance, blocking, trapping or allowing passing the injected skyrmion. In addition, the skyrmion trapping operation can be further exploited in developing special designed racetrack devices with logic AND and NOT, wherein a set of logic AND operations can be realized via skyrmion-skyrmion repulsion between two skyrmions. These results indicate an effective method for tailoring the skyrmion structures and motion behaviors by using inhomogeneous PMA, which further provide a new pathway to all-electric skyrmion-based memory and logic devices.

20.
Dev Cell ; 57(1): 80-94.e7, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34942115

RESUMO

Niches maintain a finite pool of stem cells via restricted space and short-range signals. Stem cells compete for limited niche resources, but the mechanisms regulating competition are poorly understood. Using the Drosophila testis model, we show that germline stem cells (GSCs) lacking the transcription factor Chinmo gain a competitive advantage for niche access. Surprisingly, chinmo-/- GSCs rely on a new mechanism of competition in which they secrete the extracellular matrix protein Perlecan to selectively evict non-mutant GSCs and then upregulate Perlecan-binding proteins to remain in the altered niche. Over time, the GSC pool can be entirely replaced with chinmo-/- cells. As a consequence, the mutant chinmo allele acts as a gene drive element; the majority of offspring inherit the allele despite the heterozygous genotype of the parent. Our results suggest that the influence of GSC competition may extend beyond individual stem cell niche dynamics to population-level allelic drift and evolution.

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