Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 265
Filtrar
Mais filtros

País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Electrophoresis ; 45(3-4): 275-287, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37768831

RESUMO

Microcystin-LR (MC-LR), as a hepatotoxin, can cause liver swelling, hepatitis, and even liver cancer. In this study, MC-LR aptamer (Apt-3) modified graphene oxide (GO) was designed to enrich MC-LR in white jade snail (Achatina fulica) and pond water, followed by matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) analysis. Results indicated that the Apt-3/PEG/GO nanocomposites were highly specific to MC-LR, and the detection limit of MALDI-MS was 0.50 ng/mL. Moreover, the MC-LR can be released from nanocomposites at 75°C, thus, the reuse of Apt-3/PEG/GO is realized. Real sample analysis indicated that the Apt-3/PEG/GO nanocomposites coupled with MALDI-MS were efficient in detecting trace amounts of MC-LR in real samples. With the merits of being low cost, reusable, and easy to besynthesized, this Apt-3/PEG/GO MALDI-MS is expected to be comprehensively applied by anchoring suitable aptamers for different targets.


Assuntos
Grafite , Lasers , Toxinas Marinhas , Microcistinas , Oligonucleotídeos , Caramujos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos
2.
Opt Lett ; 49(2): 214-217, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38194531

RESUMO

Although phosphorene quantum dots (PQDs) have gained significant attention in optoelectronics and physics due to their unique optical responses, the low-frequency electromagnetic properties of PQDs and the effects of temperature still remain largely unexplored. Herein, we investigate the temperature-dependent terahertz (THz) response of PQDs by using THz time-domain spectroscopy. Effective THz conductivity of the PQD sample is extracted based on THz measurements to analyze the charge carrier behavior. It is shown that the carriers in the PQDs can be approximated as a weakly confined Drude gas of classical and noninteracting charge particles, which are described by the modified Drude-Smith formula. Then, we also obtain the temperature dependences of the effective characteristic parameters for the charge carriers. As the temperature increases, the plasma frequency linearly enhances whereas both of the carrier diffusion time and the momentum scattering time decrease, which are akin to conventional semiconductors to a large extent. In addition, the confinement factor is closed to 1 and nearly insensitive to temperature. These results are helpful to gain an in-depth understanding of the low-frequency electromagnetic response of charge carriers in PQDs and to explore new applications in photonics and optoelectronics.

3.
BMC Ophthalmol ; 24(1): 110, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38454381

RESUMO

BACKGROUND: To investigate the change in the distance between corneal apex and pupil center after small-incision lenticule extraction (SMILE) or implantable collamer lens (ICL) implantation and its correlation with surgical-induced astigmatism (SIA). METHODS: This study included patients who had undergone SMILE (n = 112) or ICL implantation (n = 110) to correct myopia and myopic astigmatism. The angle kappa was measured using a Scheimpflug imaging device (Pentacam) and represented as Cartesian values between the pupil center and the corneal vertex (X, Y) and chord u ([Formula: see text]orientation), and was compared pre- and post-operative. RESULTS: Following SMILE, the magnitude of chord u[Formula: see text]) significantly increased in both eyes (Wilcoxon signed-rank test, OD: P<0.001; OS: P=0.007), while no significant change was observed in the orientation. A significant correlation was found between the J0 component of SIA and the change in the magnitude of chord u for both eyes (OD: R2=0.128, P<0.001; OS: R2=0.033, P=0.004). After ICL implantation, the orientation of the chord u was significantly different in the right eye (Wilcoxon signed-rank test, P = 0.008), and the Y-intercept significantly decreased in both eyes (Wilcoxon signed-rank test, P<0.001). A significant correlation was found between J0 of SIA and the change in the magnitude of chord u for the right eyes (R2=0.066, P=0.002). A significant correlation was found between J45 of SIA and the change in the magnitude of chord u for the left eyes (R2=0.037, P=0.044). CONCLUSIONS: The magnitude of the chord u increased following the SMILE procedure, whereas the Y-intercept significantly decreased after ICL implantation. SIA was related to the change in the magnitude of chord u.


Assuntos
Astigmatismo , Humanos , Astigmatismo/diagnóstico , Astigmatismo/etiologia , Astigmatismo/cirurgia , Refração Ocular , Acuidade Visual , Pupila , Topografia da Córnea
4.
Planta ; 257(6): 107, 2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-37130977

RESUMO

MAIN CONCLUSION: TabZIP60 is found to interact with TaCDPK30 and act as a positive regulator of ABA synthesis-mediated salt tolerance in wheat. Wheat basic leucine zipper (bZIP) transcription factor (TabZIP60) was previously found to act as a positive regulator of salt resistance. However, its molecular mechanism in response to salt stress in wheat is still unclear. In this study, TabZIP60 was found to interact with wheat calcium-dependent protein kinase (TaCDPK30), which belonged to group III of CDPK family, and was induced by salt, polyethylene glycol, and abscisic acid (ABA) treatments. This mutation of serine 110 in TabZIP60 resulted in no interaction with TaCDPK30. Moreover, TaCDPK30 was involved in interactions with wheat protein phosphatase 2C clade A (TaPP2CA116/TaPP2CA121). TabZIP60-overexpressing wheat plants showed increased salt tolerance, as exhibited by better growth status, higher soluble sugar, and lower malonaldehyde contents of transgenic plants than wild-type wheat cv. Kenong 199 under salt stress. Moreover, transgenic lines showed high ABA content by upregulating ABA synthesis-related gene expression levels. TabZIP60 protein could bind and interact with the promoter of the wheat nine-cis epoxycarotenoid dioxygenase (TaNCED2) gene. Furthermore, TabZIP60 upregulated several stress response gene expression levels, which could also increase the plant's ability to resist salt stress. Thus, these results suggest that TabZIP60 could function as a regulator of ABA synthesis-mediated salt tolerance through interacting with TaCDPK30 in wheat.


Assuntos
Tolerância ao Sal , Triticum , Triticum/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Plantas Geneticamente Modificadas/genética , Regulação da Expressão Gênica de Plantas , Ácido Abscísico/metabolismo , Estresse Fisiológico/genética
5.
Inorg Chem ; 62(5): 2289-2303, 2023 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-36692474

RESUMO

Given the global warming caused by excess CO2 accumulation in the atmosphere, it is essential to reduce CO2 by capturing and converting it to chemical feedstock using solar energy. Herein, a novel Cs3Bi2Br9/bismuth-based metal-organic framework (Bi-MOF) composite was prepared via an in situ growth strategy of Cs3Bi2Br9 quantum dots (QDs) on the surface of Bi-MOF nanosheets through coshared bismuth atoms. The prepared Cs3Bi2Br9/Bi-MOF exhibits bifunctional merits for both the high capture and effective conversion of CO2, among which the optimized 3Cs3Bi2Br9/Bi-MOF sample shows a CO2-CO conversion yield as high as 572.24 µmol g-1 h-1 under the irradiation of a 300 W Xe lamp. In addition, the composite shows good stability after five recycles in humid air, and the CO2 photoreduction efficiency does not decrease significantly. The mechanistic investigation uncovers that the intimate atomic-level contact between Cs3Bi2Br9 and Bi-MOF via the coshared atoms not only improves the dispersion of Cs3Bi2Br9 QDs over Bi-MOF nanosheets but also accelerates interfacial charge transfer by forming a strong bonding linkage, which endows it with the best performance of CO2 photoreduction. Our new finding of bismuth-based metal-organic framework/lead-free halide perovskite by cosharing atoms opens a new avenue for a novel preparation strategy of the heterojunction with atomic-level contact and potential applications in capture and photocatalytic conversion of CO2.

6.
Inorg Chem ; 62(26): 10408-10419, 2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37347952

RESUMO

KNbO3 (KN) with a perovskite structure is an outstanding representative of lead-free piezoelectric materials, and its mesocrystals have broad application prospects in the fields of catalysis, energy storage, and conversion. However, the formation conditions of KN mesocrystals reported so far are difficult owing to their high aspect ratio and excellent preferred orientation. In this study, the solvothermal process was used successfully to prepare the flake-like potassium salt of Lindquist hexaniobate (K8Nb6O19·10H2O). Subsequently, the precursor niobate was calcined to prepare two-dimensional (2D) plate-like KN mesocrystals. The formation mechanism of the plate-like KN mesocrystals is further revealed from a paired topochemical mesocrystal conversion of K8Nb6O19·10H2O niobate. Finally, the microscopic piezoelectric and photocatalytic responses of the obtained plate-like KN mesocrystals were investigated. The high piezoelectric coefficient of plate-like KN mesocrystals implies that excellent charge separation promotes the photocatalytic performance of rhodamine B (RhB). This study provides a strategy for the efficient application of 2D oriented materials in the field of piezoelectricity and photocatalysis.

7.
Exp Brain Res ; 241(4): 951-977, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36949150

RESUMO

Over the last three decades, transcranial magnetic stimulation (TMS) has gained popularity as a tool to modulate human somatosensation. However, the effects of different stimulation types on the multiple distinct subdomains of somatosensation (e.g., tactile perception, proprioception and pain) have not been systematically compared. This is especially notable in the case of newer theta-burst stimulation protocols now in widespread use. Here, we aimed to systematically and critically review the existing TMS literature and provide a complete picture of current knowledge regarding the role of TMS in modulating human somatosensation across stimulation protocols and somatosensory domains. Following the PRISMA guidelines, fifty-four studies were included in the current review and were compared based on their methodologies and results. Overall, findings from these studies provide evidence that different types of somatosensation can be both disrupted and enhanced by targeted stimulation of specific somatosensory areas. Some mixed results, however, were reported in the literature. We discussed possible reasons for these mixed results, methodological limitations of existing investigations, and potential avenues for future research.


Assuntos
Percepção do Tato , Estimulação Magnética Transcraniana , Humanos , Estimulação Magnética Transcraniana/métodos , Córtex Somatossensorial/fisiologia , Percepção do Tato/fisiologia , Dor
8.
Graefes Arch Clin Exp Ophthalmol ; 261(10): 2743-2753, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36944752

RESUMO

PURPOSE: This study aimed to determine the preferred protocol of corneal collagen cross-linking (CXL) in the treatment of progressive keratoconus. METHODS: Relevant studies were retrieved in PubMed, EMBASE and Cochrane Central Register of Controlled Trials (CENTRAL). Maximum keratometry value (Kmax), best spectacle-corrected visual acuity (BSCVA), manifest refraction spherical equivalent (MRSE), and endothelial cell density (ECD) were evaluated in network meta-analysis. RESULTS: Eight randomized controlled trials (RCTs) were included. Low-level evidence suggested that aCXL with 30mW/cm2 for 3 min (aCXL-3) might be the best protocol for reducing BSCVA (65.22%) but worst protocol for reducing MRSE (51.53%). aCXL with 18mW/cm2 for 5 min (aCXL-5) might be the best protocol for reducing Kmax (39.58%) and MRSE (77.85%) but might be the worst for preserving ECD (50.98%). aCXL with 9mW/cm2 for 10 min (aCXL-10) might be the best protocol for preserving ECD (31.53%). CONCLUSION: Overall, three protocols of aCXL are comparable in therapeutic efficacy and safety for treating progressive keratoconus. Despite no direct data comparing the efficacy of each technique according to different patients' profiles, it is reasonable to state that aCXL-5 may be the best for patients at early-stage to reduce Kmax and MRSE, aCXL-3 may be the best for patients at mid-stage to improve BSCVA, and aCXL-10 may be the best for patients at late-stage to preserve DEC.


Assuntos
Crosslinking Corneano , Ceratocone , Humanos , Ceratocone/diagnóstico , Ceratocone/tratamento farmacológico , Metanálise em Rede , Fármacos Fotossensibilizantes/uso terapêutico , Protocolos Clínicos
9.
BMC Ophthalmol ; 23(1): 36, 2023 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-36703165

RESUMO

BACKGROUND: To compare the characteristics of corneal thickness measurements among the RTVue, Casia-2, and Pentacam in patients with mild-to-moderate keratoconus. METHODS: We recruited 46 eyes of 46 patients diagnosed with mild-to-moderate keratoconus at our hospital between January and March 2022. The central corneal thickness (CCT) and thinnest corneal thickness (TCT) were measured using two optical coherence tomography (OCT) instruments (RTVue and Casia-2) and the more conventional Pentacam. Differences and correlations between the CCTs and TCTs, based on the device and influencing factors, were explored. RESULTS: The CCTs were highly consistent among the groups (p = 0.434) and correlated with one another (p < 0.001). The TCTs measured by OCTs were thinner than those measured by the Pentacam (p < 0.001); however, all three devices were highly correlated (p < 0.001). The thinnest point location measurements with RTVue and Casia-2 differed significantly from the measurements with the Pentacam. Bland-Altman plots demonstrated a significant agreement between Pentacam and OCTs in TCT measurement (p < 0.001); the 95% limits of agreement were - 3.1 µm to + 33.1 µm for Pentacam and RTVue and - 8.6 µm to + 36.5 µm for Pentacam and Casia-2. RTVue and Casia-2 showed no difference in corneal thickness (p = 0.633) and thinnest point location measurement (p > 0.05). Multivariate analysis identified that the TCT measurement difference between the RTVue and Pentacam was related to the difference between the CCT and TCT (b = 0.490, 95% confidence interval [CI]: 0.033 to 0.948, p = 0.036), whereas the difference between the Casia-2 and Pentacam was related to the anterior radius for curvature (A) grade (b = 3.9, 95% CI: 1.753 to 6.074, p = 0.001), corneal pachymetry at the thinnest (C) grade (b = - 7.875, 95% CI: - 11.404 to - 4.346, p < 0.001), and the difference between the CCT and TCT (b = 0.425, 95% CI: 0.1 to 0.751, p = 0.012). CONCLUSIONS: CCTs in patients with mild-to-moderate keratoconus were similar among all three devices, but the TCTs and the thinnest point locations were not. Furthermore, the TCT measurement differences between the OCT devices and the Pentacam were more pronounced in keratoconus cases with a steeper anterior surface, thicker TCTs, and a larger difference between the CCT and TCT. TRIAL REGISTRATION: Number: 2021118-1. Retrospectively registered: September 01, 2021.


Assuntos
Ceratocone , Humanos , Paquimetria Corneana/métodos , Ceratocone/diagnóstico , Córnea , Estudos Prospectivos , Reprodutibilidade dos Testes , Topografia da Córnea/métodos , Tomografia de Coerência Óptica/métodos
10.
BMC Anesthesiol ; 23(1): 416, 2023 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-38114922

RESUMO

BACKGROUND: Patients admitted to the surgical intensive care unit (SICU) often suffer from multi-organ dysfunction and have a high mortality rate. Therefore, finding a simple but effective clinical indicator to predict the prognosis of patients is essential to improve their survival. The aim of this study was to investigate the relationship between blood urea nitrogen to serum albumin ratio (B/A) and short-term mortality among patients from the SICU. METHODS: All eligible adult patients admitted to the SICU from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database were recruited for this study. Participants were divided into a death group (n = 638) and a survival group (n = 2,048) based on the 90-day prognosis, and then grouped by B/A quartiles. We used restricted cubic splines (RCS) to visually analyze the correlation of B/A with 30- and 90-day risk of death. Cumulative survival rates were estimated using Kaplan-Meier survival curves according to B/A quartiles and evaluated using the log-rank test. Cox proportional risk models were developed and sensitivity analyses were performed to explore whether B/A was independently associated with short-term outcomes in SICU patients. Receiver operating characteristic (ROC) curves were analyzed to ascertain the value of B/A for prognosticating 90-day outcome. RESULTS: A total of 2686 participants were included in the final study, and their 30-day and 90-day all-cause mortality rates were 17.61% and 23.75%, respectively. The differences in 30-day and 90-day mortality rates were statistically significant among the four groups of patients (all p < 0.001). RCS curves showed that B/A was linearly associated with the risk of 30-day and 90-day all-cause mortality in SICU patients (χ2 = 0.960, p = 0.811; χ2 = 1.940, p = 0.584). Kaplan-Meier analysis showed that the 90-day cumulative survival rate gradually decreased as B/A increased, with patients in the highest quartile of B/A having the lowest survival rate (p < 0.001). Cox regression indicated that elevated B/A (> 9.69) was an independent risk factor for 30-day and 90-day all-cause mortality in SICU patients. The analysis of ROC curves demonstrated that B/A exhibited a significant predictive ability for 90-day mortality, with an optimal threshold of 6.587, a sensitivity of 56.9%, and a specificity of 64.8%. CONCLUSIONS: Elevated B/A (> 9.69) on admission was an independent risk factor for short-term mortality in SICU patients, and clinicians should pay more attention to this group of patients and intervene clinically at an early stage to reduce mortality.


Assuntos
Unidades de Terapia Intensiva , Albumina Sérica , Adulto , Humanos , Nitrogênio da Ureia Sanguínea , Estudos Retrospectivos , Prognóstico , Cuidados Críticos
11.
J Neurosci ; 41(5): 1059-1067, 2021 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-33298537

RESUMO

Speech processing relies on interactions between auditory and motor systems and is asymmetrically organized in the human brain. The left auditory system is specialized for processing of phonemes, whereas the right is specialized for processing of pitch changes in speech affecting prosody. In speakers of tonal languages, however, processing of pitch (i.e., tone) changes that alter word meaning is left-lateralized indicating that linguistic function and language experience shape speech processing asymmetries. Here, we investigated the asymmetry of motor contributions to auditory speech processing in male and female speakers of tonal and non-tonal languages. We temporarily disrupted the right or left speech motor cortex using transcranial magnetic stimulation (TMS) and measured the impact of these disruptions on auditory discrimination (mismatch negativity; MMN) responses to phoneme and tone changes in sequences of syllables using electroencephalography (EEG). We found that the effect of motor disruptions on processing of tone changes differed between language groups: disruption of the right speech motor cortex suppressed responses to tone changes in non-tonal language speakers, whereas disruption of the left speech motor cortex suppressed responses to tone changes in tonal language speakers. In non-tonal language speakers, the effects of disruption of left speech motor cortex on responses to tone changes were inconclusive. For phoneme changes, disruption of left but not right speech motor cortex suppressed responses in both language groups. We conclude that the contributions of the right and left speech motor cortex to auditory speech processing are determined by the functional roles of acoustic cues in the listener's native language.SIGNIFICANCE STATEMENT The principles underlying hemispheric asymmetries of auditory speech processing remain debated. The asymmetry of processing of speech sounds is affected by low-level acoustic cues, but also by their linguistic function. By combining transcranial magnetic stimulation (TMS) and electroencephalography (EEG), we investigated the asymmetry of motor contributions to auditory speech processing in tonal and non-tonal language speakers. We provide causal evidence that the functional role of the acoustic cues in the listener's native language affects the asymmetry of motor influences on auditory speech discrimination ability [indexed by mismatch negativity (MMN) responses]. Lateralized top-down motor influences can affect asymmetry of speech processing in the auditory system.


Assuntos
Estimulação Acústica/métodos , Percepção Auditiva/fisiologia , Idioma , Córtex Motor/fisiologia , Percepção da Fala/fisiologia , Estimulação Magnética Transcraniana/métodos , Adolescente , Adulto , Eletroencefalografia/métodos , Feminino , Humanos , Masculino , Adulto Jovem
12.
J Neurophysiol ; 128(6): 1469-1482, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36350054

RESUMO

Although movement variability is often attributed to unwanted noise in the motor system, recent work has demonstrated that variability may be actively controlled. To date, research on regulation of motor variability has relied on relatively simple, laboratory-specific reaching tasks. It is not clear how these results translate to complex, well-practiced tasks. Here, we test how variability is regulated during speech production, a complex, highly overpracticed, and natural motor behavior that relies on auditory and somatosensory feedback. Specifically, in a series of four experiments, we assessed the effects of auditory feedback manipulations that modulate perceived speech variability, shifting every production either toward (inward pushing) or away from (outward pushing) the center of the distribution for each vowel. Participants exposed to the inward-pushing perturbation (experiment 1) increased produced variability while the perturbation was applied as well as after it was removed. Unexpectedly, the outward-pushing perturbation (experiment 2) also increased produced variability during exposure, but variability returned to near-baseline levels when the perturbation was removed. Outward-pushing perturbations failed to reduce participants' produced variability both with larger perturbation magnitude (experiment 3) and after their variability had increased above baseline levels as a result of the inward-pushing perturbation (experiment 4). Simulations of the applied perturbations using a state-space model of motor behavior suggest that the increases in produced variability in response to the two types of perturbations may arise through distinct mechanisms. Together, these results suggest that motor variability is actively monitored and can be modulated even in complex and well-practiced behaviors such as speech.NEW & NOTEWORTHY By implementing a novel auditory feedback perturbation that modulates participants' perceived trial-to-trial variability without affecting their overall mean behavior, we show that variability in the speech motor system can be modulated. By assaying speech production, we expand our current understanding of variability to a well-practiced, complex behavior outside of the limb control system. Our results additionally highlight the need to incorporate the active control of variability in models of speech motor control.


Assuntos
Percepção da Fala , Fala , Humanos , Fala/fisiologia , Percepção da Fala/fisiologia , Estimulação Acústica/métodos , Retroalimentação Sensorial/fisiologia , Movimento
13.
Mol Cancer ; 21(1): 12, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34986849

RESUMO

BACKGROUND: More and more studies have shown that circular RNAs (circRNAs) play a critical regulatory role in many cancers. However, the potential molecular mechanism of circRNAs in prostate cancer (PCa) remains largely unknown. METHODS: Differentially expressed circRNAs were identified by RNA sequencing. The expression of hsa_circ_0003258 was evaluated using quantitative real-time PCR and RNA in situ hybridization. The impacts of hsa_circ_0003258 on the metastasis of PCa cells were investigated by a series of in vitro and in vivo assays. Lastly, the underlying mechanism of hsa_circ_0003258 was revealed by Western blot, biotin-labeled RNA pulldown, RNA immunoprecipitation, luciferase assays and rescue experiments. RESULTS: Increased expression of hsa_circ_0003258 was found in PCa tissues and was associated with advanced TNM stage and ISUP grade. Overexpression of hsa_circ_0003258 promoted PCa cell migration by inducing epithelial mesenchymal transformation (EMT) in vitro as well as tumor metastasis in vivo, while knockdown of hsa_circ_0003258 exerts the opposite effect. Mechanistically, hsa_circ_0003258 could elevate the expression of Rho GTPase activating protein 5 (ARHGAP5) via sponging miR-653-5p. In addition, hsa_circ_0003258 physically binds to insulin like growth factor 2 mRNA binding protein 3 (IGF2BP3) in the cytoplasm and enhanced HDAC4 mRNA stability, in which it activates ERK signalling pathway, then triggers EMT programming and finally accelerates the metastasis of PCa. CONCLUSIONS: Upregulation of hsa_circ_0003258 drives tumor progression through both hsa_circ_0003258/miR-653-5p/ARHGAP5 axis and hsa_circ_0003258/IGF2BP3 /HDAC4 axis. Hsa_circ_0003258 may act as a promising biomarker for metastasis of PCa and an attractive target for PCa intervention.


Assuntos
Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Neoplasias da Próstata/genética , Interferência de RNA , RNA Circular/genética , Proteínas de Ligação a RNA/genética , Idoso , Idoso de 80 Anos ou mais , Animais , Estudos de Casos e Controles , Linhagem Celular Tumoral , Modelos Animais de Doenças , Progressão da Doença , Humanos , Sistema de Sinalização das MAP Quinases , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Estabilidade de RNA , Proteínas de Ligação a RNA/metabolismo
14.
Environ Microbiol ; 24(2): 551-565, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-33817959

RESUMO

In oligotrophic oceans, low bioavailability of Fe is a key factor limiting primary productivity. However, excessive Fe in cells leads to the Fenton reaction, which is toxic to cells. Cyanobacteria must strictly maintain intracellular Fe homeostasis. Here, we knocked out a series of genes encoding efflux systems in Synechocystis sp. PCC 6803, and found eight genes that are required for high Fe detoxification. Unexpectedly, the HlyBD-TolC efflux system plays an important role in the adaptation of Synechocystis under Fe-deficient conditions. Mutants of HlyD and TolC grew worse than the wild-type strain under low-Fe conditions and showed significantly lower intracellular Fe contents than the wild-type strain. We excluded the possibility that the low Fe sensitivity of the HlyBD-TolC mutants was caused by a loss of the S-layer, the main extracellular protein secreted via this efflux system. Inactivation of the HlyD protein influenced type IV pili formation and direct inactivation of type IV pili related genes affected the adaptation to low-Fe conditions. HlyBD-TolC system is likely involved in the formation of type IV pili and indirectly influenced Fe acquisition. Our findings suggest that efflux system in non-siderophore-producing cyanobacteria can facilitate Fe uptake and help cells adapt to Fe-deficient conditions via novel pathways.


Assuntos
Synechocystis , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Transporte Biológico/genética , Fímbrias Bacterianas/metabolismo , Homeostase , Ferro/metabolismo , Synechocystis/genética , Synechocystis/metabolismo
15.
Bioorg Chem ; 122: 105722, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35303622

RESUMO

Disruption of the dynamic equilibrium of microtubules can induce cell cycle arrest in G2/M phase and apoptosis. Hence, discovery of novel tubulin polymerization inhibitors is very necessary and an important task in drug research and development for treatment of various tumors. In this investigation, 50 compounds were screened as microtubule stabilizers targeting the taxane site by combination of molecular docking methods. Among these hits, hits 19 and 38 with novel scaffolds exhibited the highest anti-proliferative activity with IC50 ranging from 9.50 to 13.81 µM in four cancer cell lines. The molecular dynamics simulations confirmed that tubulin and two hits could form stable systems. Meanwhile, the mechanism of the interactions between tubulin and two hits at simulated physiological conditions were probed. The in vitro tubulin polymerization assay revealed hits 19 and 38 were able to promote tubulin polymerization in a dose-dependent manner. Further, the immunofluorescence assay suggested that hits 19 and 38 could accelerate microtubule assembly in A549 and HeLa cells. Finally, studies on antitumor activity indicated that hits 19 and 38 induced G2/M phase cell cycle arrest and apoptosis, and inhibited cancer cell motility and migration in A549 and HeLa cells. Importantly, hit38 exhibited better anti-tubulin and anti-cancer activity than hit19 in A549 and HeLa cells. Therefore, these results suggest that hit38 represents a promising microtubule stabilizer for treating cancer and deserves further investigation.


Assuntos
Antineoplásicos , Simulação de Dinâmica Molecular , Antineoplásicos/química , Sítios de Ligação , Hidrocarbonetos Aromáticos com Pontes , Proliferação de Células , Ensaios de Seleção de Medicamentos Antitumorais , Células HeLa , Humanos , Microtúbulos/metabolismo , Simulação de Acoplamento Molecular , Taxoides , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/química
16.
Exp Appl Acarol ; 88(1): 57-74, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36255591

RESUMO

Mites from the Acaroidea (Sarcoptiformes: Astigmatina) are important pests of various stored products, posing potential threats to preserved foods. In addition, mites can cause allergic diseases. Complete mitochondrial genomes (mitogenomes) are valuable resources for different research fields, including comparative genomics, molecular evolutionary analysis, and phylogenetic inference. We sequenced and annotated the complete mitogenomes of Thyreophagus entomophagus and Acarus siro. A comparative analysis was made between mitogenomic sequences from 10 species representing nine genera within Acaroidea. The mitogenomes of T. entomophagus and A. siro contained 37 genes, including 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), two ribosomal RNAs (rRNAs), and one control region. In Acaroidea species, mitogenomes have highly conserved gene size and order, and codon usage. Among Acaroidea mites, most PCGs were found to be under purifying selection, implying that most PCGs might have evolved slowly. Our findings showed that nad4 evolved most rapidly, whereas cox1 and cox3 evolved most slowly. The evolutionary rates of Acaroidea vary considerably across families. In addition, selection analyses were also performed in 23 astigmatid mite species, and the evolutionary rate of the same genes in different superfamilies exhibited large differences. Phylogenetic results are mostly consistent with those identified by previous phylogenetic studies on astigmatid mites. The monophyly of Acaroidea was rejected, and the Suidasiidae and Lardoglyphidae appeared to deviate from the Acaroidea branch. Our research proposed a review of the current Acaroidea classification system.


Assuntos
Acaridae , Genoma Mitocondrial , Ácaros , Animais , Filogenia , Ácaros/genética , RNA de Transferência/genética , Evolução Molecular , RNA Ribossômico/genética , Acaridae/genética
17.
BMC Oral Health ; 22(1): 51, 2022 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-35241050

RESUMO

OBJECTIVES: This study aimed to assess whether functional mandibular advancement (FMA) will cause temporomandibular joint disorders (TMD) or have side effects on temporomandibular joint (TMJ) in adolescent patients. METHODS: All searched databases, including PubMed, Web of Science, EMBASE, Cochrane Central Register of Controlled Trails and Scopus were searched. Gray literature and unpublished literature was also searched. Randomized controlled trails (RCT) and non-randomized studies of the effects of interventions (NRSI) directly observe the condition of adolescent patients' TMJ after finishing treatment will be considered to include in our study. According to Cochrane Handbook, Cochrane Collaboration risk of bias tool was used to assess the quality of included RCTs, and Risk of Bias In Non-randomized Studies of Interventions (ROBINS-I) tool was used to assess the quality of included NRSIs. RESULT: Finally 18 researches were evaluated as eligible to include in this study. 5 of the studies were RCTs, 8 were NRSIs and 5 were systematic reviews. The data of RCTs and NRSIs were statistically pooled in meta-analysis. The number of samples under investigated among primary studies was 579 individuals,there were 80 patients who developed temporomandibular symptoms during or after treatment. But all the subjective symptoms disappeared during follow-up time. The statistical outcomes proved that patients received FMA didn't show more tendency to develop temporomandibular symptoms [I2 = 27%, OR = 0.54, 95%CI (0.33,0.87), p = 0.01]. CONCLUSION: (1) TMJ symptoms may occur during the functional oral appliance wearing, but the symptoms will release or disappear after treatment or during the follow-up period. (2) Less convincing evidence indicates that slightly previous TMD and condyle-glenoid fossa relationship will be improved after treatment. (3) There is TMJ disc anterior displacement observed during treatment, but most of them will return to the normal position later. (4) Moderate evidence support that FMA will not have side effects on TMJ of adolescent patients.


Assuntos
Má Oclusão Classe II de Angle , Avanço Mandibular , Transtornos da Articulação Temporomandibular , Adolescente , Humanos , Má Oclusão Classe II de Angle/terapia , Ensaios Clínicos Controlados Aleatórios como Assunto , Articulação Temporomandibular , Transtornos da Articulação Temporomandibular/diagnóstico , Transtornos da Articulação Temporomandibular/terapia
18.
Plant Mol Biol ; 106(1-2): 21-32, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33554307

RESUMO

KEY MESSAGE: This paper demonstrates that BBX28 and BBX29 proteins in Arabidopsis promote flowering in association with the CO-FT regulatory module at low ambient temperature under LD conditions. Flowering plants integrate internal developmental signals with external environmental stimuli for precise flowering time control. The expression of BBX29 is up-regulated by low temperature treatment, but the biological function of BBX29 in low temperature response is unknown. In the current study, we examined the biological role of BBX29 and its close-related protein BBX28 in flowering time control under long-day conditions. Although neither BBX28 single mutant nor BBX29 single mutant has a flowering-associated phenotype, the bbx28 bbx29 double mutant plants have an obvious delayed flowering phenotype grown at low ambient temperature (16°C) compared to the wild-type (WT) plants. The expression of FT and TSF was lower in bbx28 bbx29 double mutant plants than in wild-type plants at 16°C. Both BBX28 and BBX29 interact with CONSTANS (CO), an important flowering integrator that directly binds to the FLOWERING LOCUS T (FT) promoter. In the effector-reporter assays, transcriptional activation activity of CO on the FT promoter was reduced in bbx28 bbx29 double mutant plants compared to that in WT plants. Taken together, our results reveal that BBX28 and BBX29 are promoters of flowering in Arabidopsis, especially at low ambient temperature.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Flores/fisiologia , Temperatura , Fatores Genéricos de Transcrição/metabolismo , Fatores de Transcrição/metabolismo , Sequência de Aminoácidos , Arabidopsis/genética , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Sequência de Bases , Regulação da Expressão Gênica de Plantas , Mutação com Perda de Função/genética , Regiões Promotoras Genéticas , Ligação Proteica , Domínios Proteicos , Fatores de Tempo , Fatores de Transcrição/química , Fatores de Transcrição/genética , Fatores Genéricos de Transcrição/química , Fatores Genéricos de Transcrição/genética , Transcrição Gênica , Regulação para Cima/genética
19.
J Cell Biochem ; 122(11): 1609-1624, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34237164

RESUMO

Microtubules play crucial role in process of mitosis and cell proliferation, which have been considered as attractive drug targets for anticancer therapy. The aim of this study was to discover novel and chemically diverse tubulin inhibitors for treatment of cancer. In this investigation, the multilayer virtual screening methods, including common feature pharmacophore model, structure-based pharmacophore model and molecular docking, were developed to screen BioDiversity database with 30,000 compounds. A total of 102 compounds were obtained by the virtual screening, and further filtered by diverse chemical clusters with desired properties and PAINS analysis. Finally, 50 compounds were selected and submitted to the biological evaluation. Among these hits, hits 8 and 30 with novel scaffolds displayed stronger antiproliferative activity on four human tumor cells including Hela, A549, MCF-7, and HepG2. Moreover, the two hits were subsequently submitted to molecular dynamic simulations of 90 ns with the aim of exploring the stability of ligand-protein interactions into the binding pocket, and further probing the mechanism of the interaction between tubulin and hits. The molecular dynamic simulation results revealed there had stronger interactions between tubulin and hits in equilibrium state. Therefore, the hits 8 and 30 have been well characterized as lead compounds for developing new tubulin inhibitors with potential anticancer activity.


Assuntos
Taxoides/metabolismo , Moduladores de Tubulina/química , Moduladores de Tubulina/farmacologia , Tubulina (Proteína)/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Humanos , Ligação de Hidrogênio , Ligantes , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Reprodutibilidade dos Testes , Taxoides/química , Tubulina (Proteína)/metabolismo
20.
Biochem Biophys Res Commun ; 584: 73-79, 2021 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-34773852

RESUMO

Radiotherapy plays a major role in non-small cell lung cancer (NSCLC) treatment. The curative efficacy of advanced NSCLC is unsatisfactory because of its radioresistance to conventional radiotherapy. The biomarkers which can be used to diagnose radiosensitivity or predict for prognosis are beneficial in promoting curative effects. In this study, NSCLC cell lines with acquired radioresistance to X-rays were obtained through fractionated irradiation. The differentially expressed proteins (DEPs) between the self-established radioresistant NSCLC cell line A549-R11 and control (A549-CK) were measured by proteomic analysis. Among the detected DEPs, CRIP2, ARHGDIB, and PADI3 were validated to be up-regulated in radioresistant cells, in mRNA and protein levels. Further analysis of bioinformatics deciphered that CRIP2, as a potential biomarker for diagnosis and a key biomarker for prediction of prognosis, may impact the X-ray radiosensitivity of NSCLC by regulating the occurrence of apoptosis and cell cycle arrest; as such, it may serve as a potent therapeutic target to facilitate NSCLC radiotherapy. CRIP2 and other DEPs may shed new light on the recognition of complex factors associated with radiation-responsiveness and finally be beneficial in the advancement of personalized therapies and precision medical treatment.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Biomarcadores Tumorais/genética , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Proteínas com Domínio LIM/genética , Neoplasias Pulmonares/radioterapia , Tolerância a Radiação/genética , Células A549 , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Apoptose/genética , Apoptose/efeitos da radiação , Biomarcadores Tumorais/metabolismo , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/genética , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Humanos , Estimativa de Kaplan-Meier , Proteínas com Domínio LIM/metabolismo , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Prognóstico , Proteômica/métodos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Curva ROC , Raios X
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA