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1.
Anal Chem ; 2024 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-39298786

RESUMO

Antibody-drug conjugate (ADC) is a therapeutic modality that aims to improve payload delivery specificity and reduce systemic toxicity. Considering the complex structure of ADCs, various bioanalytical methods by liquid chromatography coupled with mass spectrometry (LC-MS), ligand binding assay (LBA) and hybrid LBA-LC-MS approaches have been established for ADC characterization and quantification. LCMS-based assays enable drug-antibody ratio (DAR) sensitive quantification of the conjugated payload. Typically, for quantitative, DAR-sensitive, assessment by LC-MS/MS,the conjugated payload is enzymatically liberated and quantified. Despite recent advances in ADC bioanalytical methods, the DAR-sensitive quantification of noncleavable linker ADCs by LC-MS/MS remains challenging. Thus, we developed a novel digestion-free middle-down mass spectrometry (DF-MDMS) using a collision-induced dissociation approach for absolute quantification of conjugated payload from four different ADCs in a biological matrix with minimum sample preparation. These results demonstrate that ADCs with different linker-payload structures can be quantified, including a noncleavable linker ADC, trastuzumab emtansine. It also shows that the assay sensitivity is comparable to the conventional ADC quantification method by linker-payload cleavage using enzyme, while the assay dynamic range depends on factors including payload ionization and dissociation efficiency, DAR and its distribution, and species abundance. By demonstrating absolute quantification of both cleavable and noncleavable linker ADCs, this novel middle-down ADC approach demonstrates its potential application in bioanalysis and analytical characterization, especially for early discovery where high-throughput screening is required as the new approach saves time and resources by not requiring enzymatic digestion for cleavable ADCs or development of anti-payload antibodies for noncleavable linker ADCs.

2.
Neuropsychiatr Dis Treat ; 20: 1615-1628, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39220600

RESUMO

Purpose: Stroke is the second leading cause of global deaths. Post-stroke seizures (PSS) can lead to lasting complications, such as prolonged hospitalizations, increased disability rates, and higher mortality. Our study investigates the associated factors that contribute to post-stroke seizures in patients at a local tertiary hospital. Patients and Methods: We designed a case-control study where patients admitted with PSS were recruited with consent. Controls admitted for stroke without seizure were then included. Suitability based on exclusion criteria was ensured before recording their sociodemographic and clinical data. An EEG was performed and read by two certified neurologists before the data was analyzed. Results: We recruited 180 participants, 90 cases and 90 matched controls. Gender (p=0.013), race (p=0.015), dyslipidemia (p<0.001), prior stroke (p<0.031), large artery atherosclerosis (p<0.001), small vessel occlusions (p<0.001), blood pressure on presentation (p<0.028) and thrombolysis administration (p<0.029) were significantly associated with the occurrence of PSS. An increase in odds of PSS was observed in the male gender (1.974), dyslipidemia (3.480), small vessel occlusions (4.578), and in participants with epileptiform changes on EEG (3.630). Conversely, lower odds of PSS were seen in participants with high blood pressure on presentation (0.505), large artery atherosclerosis (0.266), and those who underwent thrombolysis (0.319). Conclusion: This study emphasized that identifying post-stroke seizures may be aided by EEGs and recognizing at-risk groups, which include males of Chinese descent in Asia, dyslipidemia, small vessel occlusions, those with low to normal blood pressure on presentation, and epileptiform changes in EEGs.


The research aims to establish the risk factors associated with post-stroke seizures in an Asian population and their similarity to the Western literature. Our findings highlight the critical risk factors to identify in at-risk patients, which may prompt changes in guidelines in future to enhance patient outcomes and improve the quality of care.

3.
Int J Biol Macromol ; 279(Pt 3): 135424, 2024 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-39245128

RESUMO

Oral vaccines are generally perceived to be safe, easy to administer, and have the potential to induce both systemic and mucosal immune responses. However, given the challenges posed by the harsh gastrointestinal environment and mucus barriers, the development of oral vaccines necessitates the employment of a safe and efficient delivery system. In recent years, nanoparticle-based delivery has proven to be an ideal delivery vector for the manufacture of oral vaccines. Hence, considering the above, the sucralfate acidified (SA) encapsulated N-2-Hydroxypropyl trimethyl ammonium chloride chitosan (N-2-HACC)/N,O-carboxymethyl chitosan (CMCS) nanoparticles (SA@N-2-HACC/CMCS NPs) were prepared, and the BSA was used as a model antigen to investigate the immune responses. The SA@N-2-HACC/CMCS NPs had a particle size of 227 ± 7.0 nm and a zeta potential of 8.43 ± 2.62 mV. The NPs displayed slow and sustained release and high stability in simulated gastric juice and intestinal fluid. RAW 264.7 macrophage-like cell line demonstrated enhanced uptake of the SA@N-2-HACC/CMCS/BSA Nps. The vaccine via oral administration markedly enhanced the residence time of BSA in the intestine for more than 12 h and elicited the production of IgG and sIgA. The SA@N-2-HACC/CMCS NPs developed here for oral administration is an excellent technique for delivering antigens and provides a path of mucosal vaccine research.

4.
Heredity (Edinb) ; 133(4): 262-275, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39095652

RESUMO

Recombination, the process of DNA exchange between homologous chromosomes during meiosis, plays a major role in genomic diversity and evolutionary change. Variation in recombination rate is widespread despite recombination often being essential for progression of meiosis. One such variation is heterochiasmy, where recombination rates differ between sexes. Heterochiasmy has been observed across broad taxonomic groups, yet it remains an evolutionary enigma. We used Lep-MAP3, a pedigree-based software that is efficient in handling large datasets, to generate linkage maps for the hihi or stitchbird (Notiomystis cincta), utilising information from >36 K SNPs and 36 families. We constructed 29 linkage maps, including for the previously unscaffolded Z chromosome. The hihi is an endangered passerine endemic to Aotearoa New Zealand that is sexually dimorphic and exhibits high levels of sexual conflict, including sperm competition. Patterns in recombination in the hihi are consistent with those in other birds, including higher recombination rates in micro-chromosomes. Heterochiasmy in the hihi is male-biased, in line with predictions of the Haldane-Huxley rule, with the male linkage map being 15% longer. Micro-chromosomes exhibit heterochiasmy to a greater extent, contrary to that reported in other birds. At the intra-chromosomal level, heterochiasmy is higher nearer to chromosome ends and in gene-rich regions. Regions of extreme heterochiasmy are enriched for genes implicated in cell structure. This study adds an important contribution in assessing evolutionary theories of heterochiasmy and provides a framework for future studies investigating fine-scale heterochiasmy.


Assuntos
Mapeamento Cromossômico , Ligação Genética , Passeriformes , Recombinação Genética , Animais , Masculino , Feminino , Passeriformes/genética , Polimorfismo de Nucleotídeo Único , Caracteres Sexuais , Nova Zelândia
5.
Sci Rep ; 14(1): 18054, 2024 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-39103361

RESUMO

In this pilot study, we investigated the utility of handheld ultrasound-guided photoacoustic (US-PA) imaging probe for analyzing ex-vivo breast specimens obtained from female patients who underwent breast-conserving surgery (BCS). We aimed to assess the potential of US-PA in detecting biochemical markers such as collagen, lipids, and hemoglobin, and compare these findings with routine imaging modalities (mammography, ultrasound) and histopathology results, particularly across various breast densities. Twelve ex-vivo breast specimens were obtained from female patients with a mean age of 59.7 ± 9.5 years who underwent BCS. The tissues were illuminated using handheld US-PA probe between 700 and 1100 nm across all margins and analyzed for collagen, lipids, and hemoglobin distribution. The obtained results were compared with routine imaging and histopathological assessments. Our findings revealed that lipid intensity and distribution decreased with increasing breast density, while collagen exhibited an opposite trend. These observations were consistent with routine imaging and histopathological analyses. Moreover, collagen intensity significantly differed (P < 0.001) between cancerous and normal breast tissue, indicating its potential as an additional biomarker for risk stratification across various breast conditions. The study results suggest that a combined assessment of PA biochemical information, such as collagen and lipid content, superimposed on grey-scale ultrasound findings could aid in distinguishing between normal and malignant breast conditions, as well as assist in BCS margin assessment. This underscores the potential of US-PA imaging as a valuable tool for enhancing breast cancer diagnosis and management, offering complementary information to existing imaging modalities and histopathology.


Assuntos
Neoplasias da Mama , Colágeno , Hemoglobinas , Lipídeos , Técnicas Fotoacústicas , Humanos , Feminino , Técnicas Fotoacústicas/métodos , Pessoa de Meia-Idade , Hemoglobinas/análise , Hemoglobinas/metabolismo , Colágeno/metabolismo , Neoplasias da Mama/patologia , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/metabolismo , Idoso , Lipídeos/análise , Lipídeos/química , Mama/patologia , Mama/diagnóstico por imagem , Projetos Piloto , Ultrassonografia Mamária/métodos , Tomografia/métodos , Biomarcadores
6.
Biomed Pharmacother ; 179: 117304, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39178813

RESUMO

Nymphaea candida Presl (NC), traditionally used in medicine for heat syndrome-related ailments, possesses antioxidative, anti-inflammatory, hepatoprotective, and neuroprotective properties. This research investigates the antidepressant and neuroprotective effects and mechanisms of Nymphaea candida Presl ethyl acetate (NCEA). Primary components of NCEA were identified as phenolic acids and flavonoids through UPLC-MS/MS analysis. The depression mouse model was induced via intracerebroventricular injection of Lipopolysaccharide (LPS), followed by oral administration of fluoxetine and NCEA for one week. Biochemical assays and HE staining confirmed NCEA's non-toxicity and protective effects on the liver and lungs. NCEA administration mitigated LPS-induced depressive behaviors, decreased IL-1ß, TNF-α levels in the hippocampus, suppressed microglial activation, reduced Iba-1 expression, and increased NA, brain-derived neurotrophic factor (BDNF), and dendritic spine density in the hippocampus. Furthermore, NCEA enhanced cell viability in a CORT-induced PC12 cell model, decreased lactate dehydrogenase (LDH) release rate, total superoxide dismutase (SOD) inhibition rate, intracellular nitric oxide (NO) release, and reduced reactive oxygen species (ROS) production. Our research findings suggest that NCEA exhibits significant antidepressant effects, which may be attributed to its reduction of neuroinflammation, improvement in neurotransmitter levels, neuronal protection, and antioxidative stress properties.


Assuntos
Acetatos , Antidepressivos , Fármacos Neuroprotetores , Extratos Vegetais , Animais , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/isolamento & purificação , Antidepressivos/farmacologia , Antidepressivos/isolamento & purificação , Camundongos , Masculino , Extratos Vegetais/farmacologia , Extratos Vegetais/isolamento & purificação , Ratos , Acetatos/química , Acetatos/farmacologia , Células PC12 , Depressão/tratamento farmacológico , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Modelos Animais de Doenças , Lipopolissacarídeos , Comportamento Animal/efeitos dos fármacos
7.
ACS Chem Biol ; 19(9): 1982-1990, 2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39163642

RESUMO

Microcin J25 (MccJ25), a lasso peptide antibiotic with a unique structure that resembles the lariat knot, has been a topic of intense interest since its discovery in 1992. The precursor (McjA) contains a leader and a core segment. McjB is a protease activated upon binding to the leader, and McjC converts the core segment into the mature MccJ25. Previous studies suggested that these biosynthetic steps likely proceed in a (nearly) concerted fashion; however, there is only limited information regarding the structural and molecular intricacies of MccJ25 biosynthesis. To close this knowledge gap, we used AlphaFold2 to predict the structure of the precursor (McjA) in complex with its biosynthetic enzymes (McjB and McjC) and queried the critical predicted features by protein engineering. Based on the predicted structure, we designed protein variants to show that McjB can still be functional and form a proficient biosynthetic complex with McjC when its recognition and protease domains were circularly permutated or split into separate proteins. Specific residues important for McjA recognition were also identified, which permitted us to pinpoint a compensatory mutation (McjBM108T) to restore McjA/McjB interaction that rescued an otherwise nearly nonproductive precursor variant (McjAT-2M). Studies of McjA, McjB, and McjC have long been mired by them being extremely difficult to handle experimentally, and our results suggest that the AF2 predicted ternary complex structure may serve as a reasonable starting point for understanding MccJ25 biosynthesis. The prediction-validation workflow presented herein combined artificial intelligence and laboratory experiments constructively to gain new insights.


Assuntos
Bacteriocinas , Engenharia de Proteínas , Bacteriocinas/química , Bacteriocinas/metabolismo , Engenharia de Proteínas/métodos , Conformação Proteica , Modelos Moleculares
8.
J Cent Nerv Syst Dis ; 16: 11795735241274203, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39156830

RESUMO

Background: Delirium is a prevalent yet underdiagnosed disorder characterized by acute cognitive impairment. Various screening tools are available, including the Confusion Assessment Method (CAM) and 4 A's test (4AT). However, the results of these assessments may vary among raters. Therefore, we investigated the objective use of electroencephalography (EEG) in delirium and its clinical associations and predictive value. Method: This cross-sectional observational study was conducted at Hospital Canselor Tuanku Muhriz, Universiti Kebangsaan, Malaysia, from April 2021 to April 2023. This study included patients aged ≥18 years with a preliminary diagnosis of delirium. Demographic and clinical data were collected along with EEG recordings evaluated by certified neurologists to classify abnormalities and compare the associated factors between patients with delirium with or without EEG abnormalities. Results: One hundred and twenty patients were recruited, with 80.0% displaying EEG abnormalities, mostly generalized slowing (moderate to severe) and primarily generalized slowing (mild to severe), and were characterized by theta activity. Age was significantly associated with EEG abnormalities, with patients aged 75 and older demonstrating the highest incidence (88.2%). The CAM scores were strongly correlated with EEG abnormalities (r = 0.639, P < 0.001) and was a predictor of EEG abnormalities (P < 0.012), indicating that EEG can complement clinical assessments for delirium. The Richmond Agitation and Sedation Scale (RASS) scores (r = -0.452, P < 0.001) and Barthel index (BI) (r = -0.582, P < 0.001) were negatively correlated with EEG abnormalities. Additionally, a longer hospitalization duration was associated with EEG abnormalities (r = 0.250, P = 0.006) and emerged as a predictor of such changes (P = 0.030). Conclusion: EEG abnormalities are prevalent in patients with delirium, particularly in elderly patients. CAM scores and the duration of hospitalization are valuable predictors of EEG abnormalities. EEG can be an objective tool for enhancing delirium diagnosis and prognosis, thereby facilitating timely interventions.


Why was the study done? Confusion is frequently observed among patients presenting with various medical issues. There are several tests available to assist in assessment of these patients to see if the symptoms present constitute delirium. However, there may be occasions where identifying delirium is difficult despite the tools available. Electroencephalography (EEG) may be another option to assist medical personnel in diagnosing delirium. In this study, we examine the use of EEG in identification of delirium and its clinical associations. What did the researchers do? Our team studied the use of EEG in patients admitted for various medical issues with symptoms suggestive of delirium over a 2-year period. We collected relevant clinical data and performed EEG for each participant. What did the researchers find? A total of 120 participants were involved in the study. We observe abnormal EEG findings in 80% of patients with the majority showing generalized slowing. The factors associated with EEG abnormalities are advancing age, positive Confusion Assessment Method (CAM), and duration of hospitalization. What do the findings mean? As the service is not widely available, it would not be practical to substitute existing clinical assessment tools with EEG. However, we cannot discount the importance of identifying delirium due to its association with poor clinical outcomes. Therefore, for centers that may perform EEG, it may be used as an adjunct in diagnosing delirium should any doubts arise.

9.
Adv Sci (Weinh) ; : e2302713, 2024 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-39206553

RESUMO

As a new avenue for cancer research, phototheranostics has shown inexhaustible and vigorous vitality as it permits real-time diagnosis and concurrent in situ therapy upon non-invasive light-initiation. However, construction of an advanced material, allowing prominent phototheranostic outputs and synchronously surmounting the inherent deficiency of phototheranostics, would be an appealing yet significantly challenging task. Herein, an aggregation-induced emission (AIE)-active luminogen (namely DBD-TM) featured by intensive electron donor-acceptor strength and twisted architecture with finely modulated intramolecular motion, is tactfully designed and prepared. DBD-TM simultaneously possessed fluorescence emission in the second near-infrared (NIR-II) region and high-efficiency photothermal conversion. By integrating DBD-TM with anti-angiogenic agent sorafenib, a versatile nanomaterial is smoothly fabricated and utilized for trimodal imaging-navigated synergistic therapy involving photothermal therapy and anti-angiogenesis toward cancer. This advanced approach is capable of affording accurate tumor diagnosis, complete tumor elimination, and largely restrained tumor recurrence, evidently denoting a prominent theranostic formula beyond phototheranostics. This study will offer a blueprint for exploiting a new generation of cancer theranostics.

10.
Syst Biol ; 2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-39051673

RESUMO

Polyploidy is a significant mechanism in eukaryotic evolution and is particularly prevalent in the plant kingdom. However, our knowledge about this phenomenon and its effects on evolution remains limited. A major obstacle to the study of polyploidy is the great difficulty in untangling the origins of allopolyploids. Due to the drastic genome changes and the erosion of allopolyploidy signals caused by the combined effects of hybridization and complex post-polyploid diploidization processes, resolving the origins of allopolyploids has long been a challenging task. Here we revisit this issue with the interesting case of subtribe Tussilagininae (Asteraceae: Senecioneae) and by developing HomeoSorter, a new pipeline for network inferences by phasing homeologs to parental subgenomes. The pipeline is based on the basic idea of a previous study but with major changes to address the scaling problem and implement some new functions. With simulated data, we demonstrate that HomeoSorter works efficiently on genome-scale data and has high accuracy in identifying polyploid patterns and assigning homeologs. Using HomeoSorter, the maximum pseudo-likelihood model of Phylonet, and genome-scale data, we further address the complex origin of Tussilagininae, a speciose group (ca. 45 genera and 710 species) characterized by having high base chromosome numbers (mainly x = 30, 40). In particular, the inferred patterns are strongly supported by the chromosomal evidence. Tussilagininae is revealed to comprise two large groups with successive allopolyploid origins: Tussilagininae s.s. (mainly x = 30) and the Gynoxyoid group (x = 40). Two allopolyploidy events first give rise to Tussilagininae s.s., with the first event occurring between the ancestor of subtribe Senecioninae (x = 10) and a lineage (highly probably with x = 10) related to the Brachyglottis alliance, and the resulting hybrid lineage crossing with the ancestor of Chersodoma (x = 10) and leading to Tussilagininae s.s. Then, after early diversification, the Central American group (mainly x = 30) of Tussilagininae s.s., is involved in a third allopolyploidy event with, again, the Chersodoma lineage and produces the Gynoxyoid group. Our study highlights the value of HomeoSorter and the homeolog-sorting approach in polyploid phylogenetics. With rich species diversity and clear evolutionary patterns, Tussilagininae s.s. and the Gynoxyoid group are also excellent models for future investigations of polyploidy.

11.
Cureus ; 16(6): e61934, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38978941

RESUMO

Tracheoesophageal puncture (TEP) followed by voice prosthesis placement stands as the primary method for voice rehabilitation after laryngectomy, heralded for its effectiveness. While generally well-tolerated, the procedure does pose potential long-term complications. These include prosthesis valve leakage, scarring, and prosthesis displacement, all of which can impede phonation capabilities. Of these, prosthesis leakage emerges as the most critical concern, precipitated by the progressive widening of the fistula. This complication can precipitate aspiration pneumonitis, stemming from the loss of physical separation between the esophagus and trachea. This case series details three instances where persistent tracheoesophageal fistula arose following TEP, necessitating surgical intervention. Herein, we present the clinical manifestations, surgical approach employing a simple two-layer closure, and ensuing outcomes.

12.
Nat Commun ; 15(1): 5913, 2024 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-39003260

RESUMO

Traditional catalytic techniques often encounter obstacles in the search for sustainable solutions for converting CO2 into value-added products because of their high energy consumption and expensive catalysts. Here, we introduce a contact-electro-catalysis approach for CO2 reduction reaction, achieving a CO Faradaic efficiency of 96.24%. The contact-electro-catalysis is driven by a triboelectric nanogenerator consisting of electrospun polyvinylidene fluoride loaded with single Cu atoms-anchored polymeric carbon nitride (Cu-PCN) catalysts and quaternized cellulose nanofibers (CNF). Mechanistic investigation reveals that the single Cu atoms on Cu-PCN can effectively enrich electrons during contact electrification, facilitating electron transfer upon their contact with CO2 adsorbed on quaternized CNF. Furthermore, the strong adsorption of CO2 on quaternized CNF allows efficient CO2 capture at low concentrations, thus enabling the CO2 reduction reaction in the ambient air. Compared to the state-of-the-art air-based CO2 reduction technologies, contact-electro-catalysis achieves a superior CO yield of 33 µmol g-1 h-1. This technique provides a solution for reducing airborne CO2 emissions while advancing chemical sustainability strategy.

13.
Artigo em Inglês | MEDLINE | ID: mdl-39005118

RESUMO

BACKGROUND: Cancer is a significant issue worldwide. Generally, commercially available treatments, such as surgery, radiotherapy, and chemotherapy, are associated with undesirable complications. Hence, immunotherapy serves as a crucial alternative to those treatment options. OBJECTIVE: This modality is aimed to boost the immune system through the application of engineered antibodies, which can be produced using recombinant DNA technology. RESULTS: The discussion of the technologies leads to an introduction of the single-chain variable fragment (scFv). Thereafter, the advantages, disadvantages, and challenges associated with different expression systems, such as mammalian cells, yeast cells, bacterial cells, plant cells, and phage display were discussed comprehensively. CONCLUSION: Furthermore, conventional approaches such as hybridoma and modern approaches such as cell-free protein synthesis (CFPS) and simple colony assays are included. In short, this article has compiled evidence relating to each display system and may serve as a reference for those who aim to explore antibody engineering using one of the methods listed in this article.

14.
Heliyon ; 10(13): e34070, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39071654

RESUMO

Background: Data on the effect of cardiac arrest (CA), cardiogenic shock (CS), and their combination on the prognosis of Chinese patients with ST-segment elevation myocardial infarction (STEMI) are limited. The present study sought to evaluate the clinical outcomes of STEMI complicated by CA and CS, and to identify the risk factors for CA or CS. Methods: This study included 7468 consecutive patients with STEMI in China. The patients were divided into 4 groups (CA + CS, CA only, CS only, and No CA or CS). The endpoints were 30-day all-cause death and major adverse cardiovascular events. A Cox proportional hazards regression analysis was performed. Results: CA, CS, and their combination were noted in 332 (4.4 %), 377 (5.0 %), and 117 (1.6 %) among all patients. During the 30-day follow-up, 817 (10.9 %) all-cause deaths and 964 (12.9 %) major adverse cardiovascular events occurred, and the incidence of all-cause mortality (3.6 %, 62.3 %, 74.1 %, 83.3 %) and major adverse cardiovascular events (5.4 %, 67.1 %, 75.0 %, and 87.2 %) significantly increased in the No CA or CS, CS only, CA only, and CA + CS groups, respectively. In the multivariate Cox regression models, compared with the No CA or CS group, the CA + CS, CA, and CS-only groups were associated with an increased risk of all-cause death and major adverse cardiovascular events. Patients with CA + CS had the highest risk of all-cause death (hazard ratio [HR], 25.259 [95 % confidence interval (CI) 19.221-33.195]) and major adverse cardiovascular events (HR 19.098, 95%CI 14.797-24.648). Conclusions: CA, CS, and their combination were observed in approximately 11 % of Chinese patients with STEMI, and were associated with increased risk for 30-day mortality and major adverse cardiovascular events in Chinese patients with STEMI.

15.
Nat Nanotechnol ; 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39048707

RESUMO

Spin-wave excitations of magnetic moments (or magnons) can transport spin angular momentum in insulating magnetic materials. This property distinguishes magnonic devices from traditional electronics, where power consumption results from electrons' movement. Recently, magnon torques have been used to switch perpendicular magnetization in the presence of an external magnetic field. Here we present a material system composed of WTe2/antiferromagnetic insulator NiO/ferromagnet CoFeB heterostructures that allows magnetic field-free switching of the perpendicular magnetization. The magnon currents, with a spin polarization canting of -8.5° relative to the sample plane, traverse the 25-nm-thick polycrystalline NiO layer while preserving their original polarization direction, subsequently exerting an out-of-plane anti-damping magnon torque on the ferromagnetic layer. Using this mechanism, we achieve a 190-fold reduction in power consumption in PtTe2/WTe2/NiO/CoFeB heterostructures compared to Bi2Te3/NiO/CoFeB control samples, which only exhibit in-plane magnon torques. Our field-free demonstration contributes to the realization of all-electric, low-power, perpendicular magnetization switching devices.

16.
Nanoscale Horiz ; 9(9): 1522-1531, 2024 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-38954430

RESUMO

Spintronics-based artificial neural networks (ANNs) exhibiting nonvolatile, fast, and energy-efficient computing capabilities are promising neuromorphic hardware for performing complex cognitive tasks of artificial intelligence and machine learning. Early experimental efforts focused on multistate device concepts to enhance synaptic weight precisions, albeit compromising on cognitive accuracy due to their low magnetoresistance. Here, we propose a hybrid approach based on the tuning of tunnel magnetoresistance (TMR) and the number of states in the compound magnetic tunnel junctions (MTJs) to improve the cognitive performance of an all-spin ANN. A TMR variation of 33-78% is controlled by the free layer (FL) thickness wedge (1.6-2.6 nm) across the wafer. Meanwhile, the number of resistance states in the compound MTJ is manipulated by varying the number of constituent MTJ cells (n = 1-3), generating n + 1 states with a TMR difference between consecutive states of at least 21%. Using MNIST handwritten digit and fashion object databases, the test accuracy of the compound MTJ ANN is observed to increase with the number of intermediate states for a fixed FL thickness or TMR. Meanwhile, the test accuracy for a 1-cell MTJ increases linearly by 8.3% and 7.4% for handwritten digits and fashion objects, respectively, with increasing TMR. Interestingly, a multifarious TMR dependence of test accuracy is observed with the increasing synaptic complexity in the 2- and 3-cell MTJs. By leveraging on the bimodal tuning of multilevel and TMR, we establish viable paths for enhancing the cognitive performance of spintronic ANN for in-memory and neuromorphic computing.

18.
Structure ; 32(8): 1055-1067.e6, 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39013463

RESUMO

The recently emerged BA.2.86, JN.1, EG.5, EG.5.1, and HV.1 variants have a growth advantage. In this study, we explore the structural bases of receptor binding and immune evasion for the Omicron BA.2.86, JN.1, EG.5, EG.5.1, and HV.1 sub-variants. Our findings reveal that BA.2.86 exhibits strong receptor binding, whereas its JN.1 sub-lineage displays a decreased binding affinity to human ACE2 (hACE2). Through complex structure analyses, we observed that the reversion of R493Q in BA.2.86 receptor binding domain (RBD) plays a facilitating role in receptor binding, while the L455S substitution in JN.1 RBD restores optimal affinity. Furthermore, the structure of monoclonal antibody (mAb) S309 complexed with BA.2.86 RBD highlights the importance of the K356T mutation, which brings a new N-glycosylation motif, altering the binding pattern of mAbs belonging to RBD-5 represented by S309. These findings emphasize the importance of closely monitoring BA.2.86 and its sub-lineages to prevent another wave of SARS-CoV-2 infections.


Assuntos
Enzima de Conversão de Angiotensina 2 , Anticorpos Monoclonais , COVID-19 , Evasão da Resposta Imune , Ligação Proteica , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Humanos , SARS-CoV-2/imunologia , SARS-CoV-2/metabolismo , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/metabolismo , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/química , Enzima de Conversão de Angiotensina 2/metabolismo , Enzima de Conversão de Angiotensina 2/química , Enzima de Conversão de Angiotensina 2/genética , COVID-19/imunologia , COVID-19/virologia , COVID-19/metabolismo , Sítios de Ligação , Modelos Moleculares , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/metabolismo , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/metabolismo , Mutação
19.
Nano Lett ; 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38856112

RESUMO

Electrical manipulation of magnetic states in two-dimensional ferromagnetic systems is crucial in information storage and low-dimensional spintronics. Spin-orbit torque presents a rapid and energy-efficient method for electrical control of the magnetization. In this letter, we demonstrate a wafer-scale spin-orbit torque switching of two-dimensional ferromagnetic states. Using molecular beam epitaxy, we fabricate two-dimensional heterostructures composed of low crystal-symmetry WTe2 and ferromagnet CrTe2 with perpendicular anisotropy. By utilizing out-of-plane spins generated from WTe2, we achieve field-free switching of the CrTe2 perpendicular magnetization. The threshold switching current density in CrTe2/WTe2 is 1.2 × 106 A/cm2, 20 times smaller than that of the CrTe2/Pt control sample even with an external magnetic field. In addition, the switching behavior can be modulated by external magnetic fields and crystal symmetry. Our findings demonstrate a controllable and all-electric manipulation of perpendicular magnetization in a two-dimensional ferromagnet, representing a significant advancement toward the practical implementation of low-dimensional spintronic devices.

20.
Chronobiol Int ; 41(6): 904-923, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38832541

RESUMO

Chrononutrition, an emerging body of evidence on the relationship between biological rhythms and metabolism, has been established to be associated with glycemic responses. However, the available evidence is inconsistent, due to protocol variations. Therefore, this review aims to summarize the findings on chrononutrition characteristics and their association with glycemic responses among adults. Systematic searches were conducted across six databases (PubMed, EBSCO Host, ProQuest Central, MEDLINE & Ovid, Scopus and Web of Science) to identify all relevant studies published from January 2012. Two reviewers independently screened the abstracts and full-text articles based on the inclusion and exclusion criteria. Details about population characteristics, study methods and key findings were extracted following the PRISMA-ScR guideline. The quality of selected studies was evaluated using the mixed methods appraisal tool. The searchers identified 49 studies eligible for analysis. The results showed that meal timing, particularly night-time eating and snacking were associated with glycemic responses. Regarding meal regularity, skipping breakfast may affect glycemic responses, but no clear conclusion was drawn about its effect on insulin. The association between meal frequency and glycemic responses was inconclusive. Night fasting duration and restricted eating window are potentially associated with glycemic responses. The current review extensively investigates the association between chrononutrition factors and glycemic responses in adults. However, more prospective cohort and interventional studies are needed to better understand this causal-effect relationship.


Assuntos
Glicemia , Ritmo Circadiano , Humanos , Glicemia/metabolismo , Adulto , Ritmo Circadiano/fisiologia , Comportamento Alimentar/fisiologia , Refeições/fisiologia , Insulina/sangue , Insulina/metabolismo , Fatores de Tempo , Jejum/fisiologia
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