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Climate change is a defining challenge of the 21st century, and this decade is a critical time for action to mitigate the worst effects on human populations and ecosystems. Plant science can play an important role in developing crops with enhanced resilience to harsh conditions (e.g. heat, drought, salt stress, flooding, disease outbreaks) and engineering efficient carbon-capturing and carbon-sequestering plants. Here, we present examples of research being conducted in these areas and discuss challenges and open questions as a call to action for the plant science community.
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Cambio Climático , Ecosistema , Humanos , Productos Agrícolas , Carbono , SequíasRESUMEN
Electrocatalytic nitrite (NO2 -) reduction to ammonia (NH3) is a promising method for reducing pollution and aiding industrial production. However, progress is limited by the lack of efficient selective catalysts and ambiguous catalytic mechanisms. This study explores the loading of PdCu alloy onto oxygen defective TiO2-x, resulting in a significant increase in NH3 yield (from 70.6 to 366.4 µmol cm-2 h-1 at -0.6 V vs reversible hydrogen electrode) by modulating localized electron density. In situ and operando studies illustrate that the reduction of NO2 - to NH3 involves gradual deoxygenation and hydrogenation. The process also demonstrated excellent selectivity and stability, with long-term durability in cycling and 50 h stability tests. Density functional theory (DFT) calculations elucidate that the introduction of PdCu alloys further amplified electron density at oxygen vacancies (Ovs). Additionally, the TiâO bond is strengthened as the d-band center of the Ti 3d rising after PdCu loading, facilitating the adsorption and activation of *NO2. Moreover, the presence of Ovs and PdCu alloy lowers the energy barriers for deoxygenation and hydrogenation, leading to high yield and selectivity of NH3. This insight of controlling localized electron density offers valuable insights for advancing sustainable NH3 synthesis methods.
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BACKGROUND: The genomic information available for Pediococcus pentosaceus is primarily derived from fermented fruits and vegetables, with less information available from fermented meat. P. pentosaceus LL-07, a strain isolated from fermented meat, has the capability of producing exopolysaccharides (EPS). To assess the probiotic attributes of P. pentosaceus LL-07, we conducted whole-genome sequencing (WGS) using the PacBio SequelIIe and Illumina MiSeq platforms, followed by in vitro experiments to explore its probiotic potential. RESULTS: The genome size of P. pentosaceus LL-07 is 1,782,685 bp, comprising a circular chromosome and a circular plasmid. Our investigation revealed the absence of a CRISPR/Cas system. Sugar fermentation experiments demonstrated the characteristics of carbohydrate metabolism. P. pentosaceus LL-07 contains an EPS synthesis gene cluster consisting of 13 genes, which is different from the currently known gene cluster structure. NO genes associated with hemolysis or toxin synthesis were detected. Additionally, eighty-six genes related to antibiotic resistance were identified but not present in the prophage, transposon or plasmid. In vitro experiments demonstrated that P. pentosaceus LL-07 was comparable to the reference strain P. pentosaceus ATCC25745 in terms of tolerance to artificial digestive juice and bile, autoaggregation and antioxidation, and provided corresponding genomic evidence. CONCLUSION: This study confirmed the safety and probiotic properties of P. pentosaceus LL-07 via complete genome and phenotype analysis, supporting its characterization as a potential probiotic candidate.
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Fermentación , Genoma Bacteriano , Pediococcus pentosaceus , Polisacáridos Bacterianos , Probióticos , Pediococcus pentosaceus/genética , Pediococcus pentosaceus/metabolismo , Polisacáridos Bacterianos/metabolismo , Polisacáridos Bacterianos/biosíntesis , Secuenciación Completa del Genoma , Alimentos Fermentados/microbiología , Carne/microbiología , Familia de Multigenes , Genómica/métodos , Humanos , Plásmidos/genética , Microbiología de AlimentosRESUMEN
BACKGROUND: Colorectal cancer is one of the most frequently diagnosed forms of cancer, and it is associated with several common symptoms and signs such as rectal bleeding, altered bowel habits, abdominal pain, anemia, and unintentional weight loss. Sciatica, a debilitating condition in which the patient experiences paresthesia and pain in the dermatome of associated lumbosacral nerve roots or sciatic nerve distribution, is not considered one of these. Here we present a case of colorectal cancer manifesting symptoms of sciatica alone. CASE PRESENTATION: A 68-year-old male presented with progressive lower back pain radiating to his left thigh and calf over L5/S1 dermatome. Sciatica was suspected and initially underwent conservative treatment with analgesics. However, the symptoms progressed and MRI revealed an epidural abscess surprisingly. Surgical debridement was performed and pus culture isolated Streptococcus gallolyticus. Based on the strong association of S. gallolyticus with colorectal cancer, the presence of this pathogen prompted further tumor evaluation, even in the absence of the typical symptoms and signs. This investigation ultimately leads to the diagnosis of sigmoid adenocarcinoma. CONCLUSIONS: Although rare, sciatica caused by S. gallolyticus infection of the spinal epidural space may serve as the initial presentation of colorectal cancer. Physicians should be aware of the strong association between S. gallolyticus and colorectal cancer. Based on what we currently know about the condition; a thorough systematic assessment of occult neoplasia for patients with S. gallolyticus infection is recommended.
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Neoplasias del Colon , Absceso Epidural , Ciática , Masculino , Humanos , Anciano , Ciática/diagnóstico , Ciática/etiología , Absceso Epidural/diagnóstico , Absceso Epidural/cirugía , Neoplasias del Colon/complicaciones , Neoplasias del Colon/diagnóstico , Dolor Abdominal , ConcienciaciónRESUMEN
OBJECTIVE: The purpose of this study is to compare radiological and clinical outcomes between alternate levels (C4 and C6) and all levels mini-plate fixation in C3-6 unilateral open-door laminoplasty. METHODS: Ninety-six patients who underwent C3-6 unilateral open-door laminoplasty with alternate levels mini-plate fixation (54 patients in group A) or all levels mini-plate fixation (42 patients in group B) between September 2014 and September 2019 were reviewed in this study. Radiologic and clinical outcomes were assessed. Clinical results included Visual Analogue Scale (VAS) of axial neck pain and Japanese Orthopedic Association (JOA) score. Radiographic results included cervical range of motion (ROM), cervical curvature index (CCI), and the spinal canal expansive parameters including open angle, anteroposterior diameter (APD), and Pavlov`s ratio. RESULTS: There was no significant difference in VAS, JOA score, ROM, and CCI between two groups. There was no significant difference in canal expansion postoperatively between two groups. However, open angle, APD, and Pavlov`s ratio in group A decreased significantly during the follow-up. In group B, APD, Pavlov`s ratio, and open angle were maintained until the final follow-up. There was no hardware failure or lamina reclosure occurred in both groups during the follow-up. The mean cost of group B was higher than that of group A. CONCLUSIONS: Despite the differences in the maintenance of canal expansion, alternate levels mini-plate fixation can achieve similar clinical outcomes as all levels mini-plate fixation in C3-6 unilateral open-door laminoplasty. As evidenced in this study, we believe C3-6 laminoplasty with alternate levels (C4 and C6) mini-plate fixation is an economical, effective, and safe treatment method.
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Placas Óseas , Vértebras Cervicales , Laminoplastia , Humanos , Vértebras Cervicales/cirugía , Vértebras Cervicales/diagnóstico por imagen , Laminoplastia/métodos , Femenino , Persona de Mediana Edad , Estudios Retrospectivos , Masculino , Anciano , Resultado del Tratamiento , Rango del Movimiento Articular , Adulto , Dolor de Cuello/etiología , Dolor de Cuello/cirugíaRESUMEN
Intranasal administration was previously proposed for delivering drugs for central nervous system (CNS) diseases. However, the delivery and elimination pathways, which are very imperative to know for exploring the therapeutic applications of any given CNS drugs, remain far from clear. Because lipophilicity has a high priority in the design of CNS drugs, the as-prepared CNS drugs tend to form aggregates. Therefore, a PEGylated Fe3O4 nanoparticle labeled with a fluorescent dye was prepared as a model drug and studied to elucidate the delivery pathways of intranasally administered nanodrugs. Through magnetic resonance imaging, the distribution of the nanoparticles was investigated in vivo. Through ex vivo fluorescence imaging and microscopy studies, more precise distribution of the nanoparticles across the entire brain was disclosed. Moreover, the elimination of the nanoparticles from cerebrospinal fluid was carefully studied. The temporal dose levels of intranasally delivered nanodrugs in different parts of the brain were also investigated.
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Sistema Nervioso Central , Nanopartículas , Administración Intranasal , Sistema Nervioso Central/metabolismo , Encéfalo/metabolismo , Preparaciones Farmacéuticas/metabolismo , Sistemas de Liberación de Medicamentos/métodosRESUMEN
PURPOSE: Postoperative sore throat (POST) is a major complaint after day-case surgery. The objectives of this study were to investigate the risk factors for POST and develop a stratified nursing model for POST after day-case surgery. DESIGN: This case-control study was conducted at Department of Anesthesiology of 1st Affiliated Hospital of Wenzhou Medical University in Wenzhou, Zhejiang, China. METHODS: Anesthesia records and postanesthesia care files of adult patients undergoing day-case surgery with general anesthesia were reviewed. The primary outcome was the incidence of POST at 24 hours after day-case surgery or before discharge within 24 hours. Multivariate logistics regression was used to identify risk factors for POST. A nomogram was created to predict the probability of POST after day-case surgery. FINDINGS: A total of 9,312 records were retrieved from June 1, 2021 to April 30, 2022, including 8,499 files in the training group and 813 files in the validation group. One thousand five hundred and twenty-five cases in the training group experienced POST. The independent risk factors for POST included: thyroid surgery (odds ratios [OR] = 22.42, 95% confidence intervals [CI]: 18.45 to 27.25), shorter thyromental distance (OR = 1.18, 95% CI: 1.06 to 1.30), smaller neck circumference (OR = 1.09, 95% CI: 1.06 to 1.11), duration of anesthesia (OR = 1.13, 95% CI: 1.04 to 1.22), female (OR = 1.66, 95% CI: 1.41 to 1.96), age (OR = 0.99, 95% CI: 0.99 to 1.00) and the presence of bloody sputum (OR = 8.33, 95% CI: 6.53 to 10.63). A nomogram that involved five factors was established to predict the probability of POST after day-case surgery. The area under the receiver operating characteristic curve in the training and validation groups was 0.77 and 0.81, respectively. The calibration curve demonstrated good consistency between the actual POST and the predicted probability. CONCLUSIONS: The following variables are independently associated with POST: thyroid surgery, age approaching to 40 years old, female, shorter thyromental distance and smaller neck circumference, longer duration of anesthesia, and the presence of bloody sputum. A novel stratified nursing model is feasible for predicting the probability of POST.
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BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic is an unprecedented global health crisis that may cause mental health problems and heighten suicide risk. We investigated the impact of the COVID-19 pandemic on trends in suicide attempts and suicide deaths in New Taipei City, Taiwan. METHODS: The current study used the official daily data on suicide attempts and deaths in New Taipei City, Taiwan (4 million inhabitants) between 2015 and 2020 from the Taiwan National Suicide Prevention Reporting System. Interrupted time-series (ITS) analyses with parameters corrected by the estimated autocorrelations were applied on weekly aggregated data to examine whether the suicide trends during the early COVID-19 pandemic (late January to July 2020) deviated from previous trends (January 2015 to late January 2020). The impact due to the suicide prevention policy change was also examined (since August 2020). RESULTS: ITS analyses revealed no significant increases in both mean and trend on weekly suicide deaths during the COVID-19 pandemic and after the policy change. In contrast, there was a significant increasing trend in weekly suicide attempts since the COVID-19 outbreak at the rate of 1.54 attempts per week (95% confidence interval 0.49-2.60; p = 0.004). Sex difference analysis revealed that, however, this increasing trend was observed only in females not in males. CONCLUSIONS: The COVID-19 pandemic has different impacts on suicides attempts and deaths during the early pandemic in New Taipei City, Taiwan. The COVID-19 outbreak drastically increased the trend of suicide attempts. In contrast, the number of suicide deaths had remained constant in the investigated periods.
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COVID-19 , Intento de Suicidio , Humanos , Masculino , Femenino , Taiwán/epidemiología , Pandemias , CiudadesRESUMEN
The carbonization of iron is a very important early phenomenon in the field of heterogeneous catalysis and the petrochemical industry, but the mechanism is still controversial. In this work, the carbonization mechanism and carbonization structure of iron nanoparticles by different carbon sources (CH4, C2H6, C2H4, C2H2) were systematically investigated using the reactive molecular dynamics method. The results show that saturated alkanes are dehydrogenated while adsorbed, but unsaturated olefins and alkynes undergo bond-breaking while adsorbed. The C-H bond is more likely to break than the C-C bond. Hydrocarbons with high carbon content have a strong ability to carbonize Fe nanoparticles under the same conditions. For C2H4 and C2H2, the C atoms generated from dissociation form a large number of long carbon chains intertwined with branched chains and multiple carbon rings. The C2 species formed by C2H2 after complete dehydrogenation diffuse rapidly to the interior of the nanoparticles, releasing the surface active sites and accelerating the carbonization process. Carbon-rich iron carbides (FeCx) with different Fe/C ratios were obtained by carbonization with different carbon sources. In addition, the Fe(110) surface exhibits the strongest carburizing ability. These findings provide systematic insights into the initial stages of metal Fe carburization.
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OBJECTIVE: Genotype imputation is a commonly used technique that infers un-typed variants into a study's genotype data, allowing better identification of causal variants in disease studies. However, due to overrepresentation of Caucasian studies, there's a lack of understanding of genetic basis of health-outcomes in other ethnic populations. Therefore, facilitating imputation of missing key-predictor-variants that can potentially improve a risk health-outcome prediction model, specifically for Asian ancestry, is of utmost relevance. METHODS: We aimed to construct an imputation and analysis web-platform, that primarily facilitates, but is not limited to genotype imputation on East-Asians. The goal is to provide a collaborative imputation platform for researchers in the public domain towards rapidly and efficiently conducting accurate genotype imputation. RESULTS: We present an online genotype imputation platform, Multi-ethnic Imputation System (MI-System) (https://misystem.cgm.ntu.edu.tw/), that offers users 3 established pipelines, SHAPEIT2-IMPUTE2, SHAPEIT4-IMPUTE5, and Beagle5.1 for conducting imputation analyses. In addition to 1000 Genomes and Hapmap3, a new customized Taiwan Biobank (TWB) reference panel, specifically created for Taiwanese-Chinese ancestry is provided. MI-System further offers functions to create customized reference panels to be used for imputation, conduct quality control, split whole genome data into chromosomes, and convert genome builds. CONCLUSION: Users can upload their genotype data and perform imputation with minimum effort and resources. The utility functions further can be utilized to preprocess user uploaded data with easy clicks. MI-System potentially contributes to Asian-population genetics research, while eliminating the requirement for high performing computational resources and bioinformatics expertise. It will enable an increased pace of research and provide a knowledge-base for genetic carriers of complex diseases, therefore greatly enhancing patient-driven research. STATEMENT OF SIGNIFICANCE: Multi-ethnic Imputation System (MI-System), primarily facilitates, but is not limited to, imputation on East-Asians, through 3 established prephasing-imputation pipelines, SHAPEIT2-IMPUTE2, SHAPEIT4-IMPUTE5, and Beagle5.1, where users can upload their genotype data and perform imputation and other utility functions with minimum effort and resources. A new customized Taiwan Biobank (TWB) reference panel, specifically created for Taiwanese-Chinese ancestry is provided. Utility functions include (a) create customized reference panels, (b) conduct quality control, (c) split whole genome data into chromosomes, and (d) convert genome builds. Users can also combine 2 reference panels using the system and use combined panels as reference to conduct imputation using MI-System.
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Genética de Población , Genoma , Humanos , Frecuencia de los Genes , Genotipo , Computadores , Estudio de Asociación del Genoma Completo , Polimorfismo de Nucleótido SimpleRESUMEN
The antihistamine clemastine inhibits multiple stages of the Plasmodium parasite that causes malaria, but the molecular targets responsible for its parasite inhibition were unknown. Here, we applied parallel chemoproteomic platforms to discover the mechanism of action of clemastine and identify that clemastine binds to the Plasmodium falciparum TCP-1 ring complex or chaperonin containing TCP-1 (TRiC/CCT), an essential heterooligomeric complex required for de novo cytoskeletal protein folding. Clemastine destabilized all eight P. falciparum TRiC subunits based on thermal proteome profiling (TPP). Further analysis using stability of proteins from rates of oxidation (SPROX) revealed a clemastine-induced thermodynamic stabilization of the Plasmodium TRiC delta subunit, suggesting an interaction with this protein subunit. We demonstrate that clemastine reduces levels of the major TRiC substrate tubulin in P. falciparum parasites. In addition, clemastine treatment leads to disorientation of Plasmodium mitotic spindles during the asexual reproduction and results in aberrant tubulin morphology suggesting protein aggregation. This clemastine-induced disruption of TRiC function is not observed in human host cells, demonstrating a species selectivity required for targeting an intracellular human pathogen. Our findings encourage larger efforts to apply chemoproteomic methods to assist in target identification of antimalarial drugs and highlight the potential to selectively target Plasmodium TRiC-mediated protein folding for malaria intervention.
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Chaperonina con TCP-1/metabolismo , Clemastina/farmacología , Antagonistas de los Receptores Histamínicos/farmacología , Proteínas Protozoarias/metabolismo , Sitios de Unión , Línea Celular , Chaperonina con TCP-1/química , Humanos , Plasmodium falciparum/efectos de los fármacos , Plasmodium falciparum/metabolismo , Unión Proteica , Proteínas Protozoarias/química , Huso Acromático/efectos de los fármacosRESUMEN
Vascular plants provide most of the biomass, food, and feed on earth, yet the molecular innovations that led to the evolution of their conductive tissues are unknown. Here, we reveal the evolutionary trajectory for the heterodimeric TMO5/LHW transcription factor complex, which is rate-limiting for vascular cell proliferation in Arabidopsis thaliana Both regulators have origins predating vascular tissue emergence, and even terrestrialization. We further show that TMO5 evolved its modern function, including dimerization with LHW, at the origin of land plants. A second innovation in LHW, coinciding with vascular plant emergence, conditioned obligate heterodimerization and generated the critical function in vascular development in Arabidopsis In summary, our results suggest that the division potential of vascular cells may have been an important factor contributing to the evolution of vascular plants.
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Proteínas de Arabidopsis/genética , Arabidopsis/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Evolución Molecular , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Transactivadores/genética , Proteínas de Arabidopsis/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Proliferación Celular/genética , Floema/citología , Floema/crecimiento & desarrollo , Floema/metabolismo , Filogenia , Plantas Modificadas Genéticamente , Multimerización de Proteína/genética , Transactivadores/metabolismo , Xilema/citología , Xilema/crecimiento & desarrollo , Xilema/metabolismoRESUMEN
The striatal complex of basal ganglia comprises two functionally distinct districts. The dorsal district controls motor and cognitive functions. The ventral district regulates the limbic function of motivation, reward, and emotion. The dorsoventral parcellation of the striatum also is of clinical importance as differential striatal pathophysiologies occur in Huntington's disease, Parkinson's disease, and drug addiction disorders. Despite these striking neurobiologic contrasts, it is largely unknown how the dorsal and ventral divisions of the striatum are set up. Here, we demonstrate that interactions between the two key transcription factors Nolz-1 and Dlx1/2 control the migratory paths of striatal neurons to the dorsal or ventral striatum. Moreover, these same transcription factors control the cell identity of striatal projection neurons in both the dorsal and the ventral striata including the D1-direct and D2-indirect pathways. We show that Nolz-1, through the I12b enhancer, represses Dlx1/2, allowing normal migration of striatal neurons to dorsal and ventral locations. We demonstrate that deletion, up-regulation, and down-regulation of Nolz-1 and Dlx1/2 can produce a striatal phenotype characterized by a withered dorsal striatum and an enlarged ventral striatum and that we can rescue this phenotype by manipulating the interactions between Nolz-1 and Dlx1/2 transcription factors. Our study indicates that the two-tier system of striatal complex is built by coupling of cell-type identity and migration and suggests that the fundamental basis for divisions of the striatum known to be differentially vulnerable at maturity is already encoded by the time embryonic striatal neurons begin their migrations into developing striata.
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Ganglios Basales/citología , Cuerpo Estriado/citología , Estriado Ventral/citología , Animales , Ganglios Basales/metabolismo , Diferenciación Celular , Cuerpo Estriado/metabolismo , Femenino , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Interneuronas/metabolismo , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Neuronas/metabolismo , Núcleo Accumbens/citología , Núcleo Accumbens/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Estriado Ventral/metabolismoRESUMEN
Uropathogenic Escherichia coli (UPEC) is known to cause 65-75% of human urinary tract infection (UTI) cases. Poultry meat is a reservoir of UPEC, which is suspected to cause foodborne UTIs. In the present study, we aimed to determine the growth potential of UPEC in ready-to-eat chicken breasts prepared by sous-vide processing. Four reference strains isolated from the urine of UTI patients (Bioresource Collection and Research Center [BCRC] 10,675, 15,480, 15,483, and 17,383) were tested by polymerase chain reaction assay for related genes to identify their phylogenetic type and UPEC specificity. A cocktail of these UPEC strains was inoculated into sous-vide cooked chicken breast at 103-4 colony-forming unit (CFU)/g and stored at 4°C, 10°C, 15°C, 20°C, 30°C, and 40°C. Changes in the populations of UPEC during storage were analyzed by a one-step kinetic analysis method using the U.S. Department of Agriculture [USDA] Integrated Pathogen Modeling Program-Global Fit [IPMP-Global Fit]. The results showed that the combination of the no lag phase primary model and the Huang square-root secondary model fitted well with the growth curves to obtain the appropriate kinetic parameters. This combination for predicting UPEC growth kinetics was further validated using it to study additional growth curves at 25°C and 37°C, which showed that the root mean square error, bias factor, and accuracy factor were 0.49-0.59 (log CFU/g), 0.941-0.984, and 1.056-1.063, respectively. In conclusion, the models developed in this study are acceptable and can be used to predict the growth of UPEC in sous-vide chicken breast.
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Pollos , Comida Rápida , Almacenamiento de Alimentos , Carne , Escherichia coli Uropatógena , Pollos/microbiología , Comida Rápida/microbiología , Cinética , Carne/microbiología , Modelos Biológicos , Temperatura , Escherichia coli Uropatógena/clasificación , Escherichia coli Uropatógena/crecimiento & desarrollo , AnimalesRESUMEN
Nonlinear dynamics of discontinuous oscillators with unilateral constraints and non-random parametric uncertainties are investigated. Nonlinear oscillators considering single- and double-sided constraints are carefully constructed to exhibit rich bifurcations, such as period-doubling and Neimark-Sacker bifurcations. In deterministic amplitude-frequency responses, both hardening and softening effects are induced by non-smooth contact-type nonlinearities. Stabilities of the solutions are determined by the shooting method and the monodromy matrix. To effectively quantify the behaviors of nonlinear oscillators in the presence of parametric uncertainties, a non-intrusive surrogate function aided by arc-length ratio interpolation is constructed. Simulation results demonstrate variabilities of nonlinear responses under different non-random uncertainties. Moreover, an accuracy verification is provided to verify the effectiveness of the non-intrusive uncertainty propagation method. It is found that the surrogate function in combination with the arc-length ratio technique has high accuracy and evolutions of turning points are captured satisfactorily regardless of complex interactions of nonlinearities and uncertainties. The findings and methodologies reported are meaningful to general nonlinear systems having complex motions, paving the road for more in-depth investigations into uncertain nonlinear dynamics.
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Hyperpolarized carbon-13 MRI has the advantage of allowing the study of glycolytic flow in vivo or in vitro dynamically in real-time. The apparent exchange rate constant of a metabolite dynamic signal reflects the metabolite changes of a disease. Downstream metabolites can have a low signal-to-noise ratio (SNR), causing apparent exchange rate constant inconsistencies. Thus, we developed a method that estimates a more accurate metabolite signal. This method utilizes a kinetic model and background noise to estimate metabolite signals. Simulations and in vitro studies with photon-irradiated and control groups were used to evaluate the procedure. Simulated and in vitro exchange rate constants estimated using our method were compared with the raw signal values. In vitro data were also compared to the Area-Under-Curve (AUC) of the cell medium in 13C Nuclear Magnetic Resonance (NMR). In the simulations and in vitro experiments, our technique minimized metabolite signal fluctuations and maintained reliable apparent exchange rate constants. In addition, the apparent exchange rate constants of the metabolites showed differences between the irradiation and control groups after using our method. Comparing the in vitro results obtained using our method and NMR, both solutions showed consistency when uncertainty was considered, demonstrating that our method can accurately measure metabolite signals and show how glycolytic flow changes. The method enhanced the signals of the metabolites and clarified the metabolic phenotyping of tumor cells, which could benefit personalized health care and patient stratification in the future.
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Imagen por Resonancia Magnética , Ácido Pirúvico , Humanos , Cinética , Espectroscopía de Resonancia Magnética/métodos , Relación Señal-RuidoRESUMEN
Fluorinated nucleotides are invaluable for 19 F NMR studies of nucleic acid structure and function. Here, we synthesized 4'-SCF3 -thymidine (T 4 ' - SCF 3 ${{^{4{^\prime}\hbox{-}{\rm SCF}{_{3}}}}}$ ) and incorporated it into DNA by means of solid-phase DNA synthesis. NMR studies showed that the 4'-SCF3 group exhibited a flexible orientation in the minor groove of DNA duplexes and was well accommodated by various higher order DNA structures. The three magnetically equivalent fluorine atoms in 4'-SCF3 -DNA constitute an isolated spin system, offering high 19 F NMR sensitivity and excellent resolution of the positioning of T 4 ' - SCF 3 ${{^{4{^\prime}\hbox{-}{\rm SCF}{_{3}}}}}$ within various secondary and tertiary DNA structures. The high structural adaptability and high sensitivity of T 4 ' - SCF 3 ${{^{4{^\prime}\hbox{-}{\rm SCF}{_{3}}}}}$ make it a valuable 19 F NMR probe for quantitatively distinguishing diverse DNA structures with single-nucleotide resolution and for monitoring the dynamics of interactions in the minor groove of double-stranded DNA.
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ADN , Flúor , ADN/química , Espectroscopía de Resonancia Magnética , Flúor/química , Nucleótidos , Técnicas de Síntesis en Fase Sólida , Conformación de Ácido NucleicoRESUMEN
Intercellular communication coordinates hypophysis establishment in the Arabidopsis embryo. Previously, TARGET OF MONOPTEROS 7 (TMO7) was reported to be transported to the hypophysis, the founder cell of the root cap, and RNA suppression experiments implicated its function in embryonic root development. However, the protein properties and mechanisms mediating TMO7 protein transport, and the role the movement plays in development remained unclear. Here, we report that in the post-embryonic root, TMO7 and its close relatives are transported into the root cap through plasmodesmata in a sequence-dependent manner. We also show that nuclear residence is crucial for TMO7 transport, and postulate that modification, potentially phosphorylation, labels TMO7 for transport. Additionally, three novel CRISPR/Cas9-induced tmo7 alleles confirmed a role in hypophysis division, but suggest complex redundancies with close relatives in root formation. Finally, we demonstrate that TMO7 transport is biologically meaningful, as local expression partially restores hypophysis division in a plasmodesmal protein transport mutant. Our study identifies motifs and amino acids that are pivotal for TMO7 protein transport, and establishes the importance of TMO7 in hypophysis and root development.
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Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Proteínas de Arabidopsis/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Comunicación Celular , Genes de Plantas , Mutación , Fosforilación , Filogenia , Raíces de Plantas/genética , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Plantas Modificadas Genéticamente , Plasmodesmos/metabolismo , Transporte de Proteínas/genética , Homología de Secuencia de AminoácidoRESUMEN
Emerging Plasmodium parasite drug resistance is threatening progress towards malaria control and elimination. While recent efforts in cell-based, high-throughput drug screening have produced first-in-class drugs with promising activities against different Plasmodium life cycle stages, most of these antimalarial agents have elusive mechanisms of action. Though challenging to address, target identification can provide valuable information to facilitate lead optimization and preclinical drug prioritization. Recently, proteome-wide methods for direct assessment of drug-protein interactions have emerged as powerful tools in a number of systems, including Plasmodium. In this review, we will discuss current chemoproteomic strategies that have been adapted to antimalarial drug target discovery, including affinity- and activity-based protein profiling and the energetics-based techniques thermal proteome profiling and stability of proteins from rates of oxidation. The successful application of chemoproteomics to the Plasmodium blood stage highlights the potential of these methods to link inhibitors to their molecular targets in more elusive Plasmodium life stages and intracellular pathogens in the future.
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Parásitos , AnimalesRESUMEN
Fluoro-substitution on the ribose moiety (e. g., 2'-F-deoxyribonucleotide) represents a popular way to modulate the ribose conformation and, hence, the structure and function of nucleic acids. In the present study, we synthesized 4'-F-deoxythymidine (4'-F T) and introduced it to oligodeoxyribonucleotides (ODNs). Though scission of the glycosylic bond of 4'-F T followed by strand cleavage occurred to some extent under alkaline conditions, the 4'-F T-modified ODNs were rather stable in neutral buffers. NMR studies showed that like 2'-F-deoxyribonucleoside, 4'-F T exists predominantly in the North conformation not only in the nucleoside form but also in the context of ODN strands. Circular dichroism spectroscopy, thermal denaturing and RNase H1 footprinting studies of 4'-F T-modified ODN/cDNA and ODN/cRNA duplexes indicated that the North conformation tendency of 4'-F T is maintained in the duplexes, leading to a local structural perturbation. Collectively, 4'-F-deoxyribonucleotide structurally resembles the 2'-F-deoxyribonucleotide but imparts less structural perturbation to the duplex than the latter.