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1.
Proc Natl Acad Sci U S A ; 121(7): e2316825121, 2024 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-38319968

RESUMEN

Climate change is a global concern for all life on our planet, including humans and plants. Plants' growth and development are significantly affected by abiotic stresses, including adverse temperature, inadequate or excess water availability, nutrient deficiency, and salinity. The circadian clock is a master regulator of numerous developmental and metabolic processes in plants. In an effort to identify new clock-related genes and outputs through bioinformatic analysis, we have revealed that CIRCADIAN CLOCK ASSOCIATED 1 (CCA1) and LATE ELONGATED HYPOCOTYL (LHY) play a crucial role in regulating a wide range of abiotic stress responses and target ABSCISIC ACID RESPONSIVE ELEMENTS-BINDING FACTOR3 (ABF3), a key transcription factor in the plant hormone Abscisic acid (ABA)-signaling pathway. Specifically, we found that CCA1 and LHY regulate the expression of ABF3 under diel conditions, as well as seed germination under salinity. Conversely, ABF3 controls the expression of core clock genes and orchestrates the circadian period in a stress-responsive manner. ABF3 delivers the stress signal to the central oscillator by binding to the promoter of CCA1 and LHY. Overall, our study uncovers the reciprocal regulation between ABF3 and CCA1/LHY and molecular mechanisms underlying the interaction between the circadian clock and abiotic stress. This finding may aid in developing molecular and genetic solutions for plants to survive and thrive in the face of climate change.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Relojes Circadianos , Humanos , Relojes Circadianos/genética , Proteínas de Unión al ADN/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Ácido Abscísico/metabolismo , Ritmo Circadiano/genética , Regulación de la Expresión Génica de las Plantas , Estrés Fisiológico , Factores de Transcripción/metabolismo
2.
Proc Natl Acad Sci U S A ; 121(19): e2318652121, 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38687781

RESUMEN

Water oxidation on magnetic catalysts has generated significant interest due to the spin-polarization effect. Recent studies have revealed that the disappearance of magnetic domain wall upon magnetization is responsible for the observed oxygen evolution reaction (OER) enhancement. However, an atomic picture of the reaction pathway remains unclear, i.e., which reaction pathway benefits most from spin-polarization, the adsorbent evolution mechanism, the intermolecular mechanism (I2M), the lattice oxygen-mediated one, or more? Here, using three model catalysts with distinguished atomic chemistries of active sites, we are able to reveal the atomic-level mechanism. We found that spin-polarized OER mainly occurs at interconnected active sites, which favors direct coupling of neighboring ligand oxygens (I2M). Furthermore, our study reveals the crucial role of lattice oxygen participation in spin-polarized OER, significantly facilitating the coupling kinetics of neighboring oxygen radicals at active sites.

3.
Methods ; 221: 12-17, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-38006950

RESUMEN

This research aims to develop a robust and quantitative method for measuring creatinine levels by harnessing the enhanced Tyndall effect (TE) phenomenon. The envisioned sensing assay is designed for practical deployment in resource-limited settings or homes, where access to advanced laboratory facilities is limited. Its primary objective is to enable regular and convenient monitoring of renal healthcare, particularly in cases involving elevated creatinine levels. The creatinine sensing strategy is achieved based on the aggregation of gold nanoparticles (AuNPs) triggered via the direct crosslinking reaction between creatinine and AuNPs, where an inexpensive laser pointer was used as a handheld light source and a smartphone as a portable device to record the TE phenomenon enhanced by the creatinine-induced aggregation of AuNPs. After evaluation and optimization of parameters such as AuNP concentrations and TE measurement time, the subsequent proof-of-concept experiments demonstrated that the average gray value change of TE images was linearly related to the logarithm of creatinine concentrations in the range of 1-50 µM, with a limit of detection of 0.084 µM. Meanwhile, our proposed creatinine sensing platform exhibited highly selective detection in complex matrix environments. Our approach offers a straightforward, cost-effective, and portable means of creatinine detection, presenting an encouraging signal readout mechanism suitable for point-of-care (POC) applications. The utilization of this assay as a POC solution exhibits potential for expediting timely interventions and enhancing healthcare outcomes among individuals with renal health issues.


Asunto(s)
Nanopartículas del Metal , Teléfono Inteligente , Humanos , Creatinina , Oro , Urinálisis , Colorimetría/métodos
4.
Biotechnol Bioeng ; 121(5): 1729-1738, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38419489

RESUMEN

Several key technologies for advancing biopharmaceutical manufacturing depend on the successful implementation of process analytical technologies that can monitor multiple product quality attributes in a continuous in-line setting. Raman spectroscopy is an emerging technology in the biopharma industry that promises to fit this strategic need, yet its application is not widespread due to limited success for predicting a meaningful number of quality attributes. In this study, we addressed this very problem by demonstrating new capabilities for preprocessing Raman spectra using a series of Butterworth filters. The resulting increase in the number of spectral features is paired with a machine learning algorithm and laboratory automation hardware to drive the automated collection and training of a calibration model that allows for the prediction of 16 different product quality attributes in an in-line mode. The demonstrated ability to generate these Raman-based models for in-process product quality monitoring is the breakthrough to increase process understanding by delivering product quality data in a continuous manner. The implementation of this multiattribute in-line technology will create new workflows within process development, characterization, validation, and control.


Asunto(s)
Espectrometría Raman , Proteína Estafilocócica A , Espectrometría Raman/métodos , Automatización , Cromatografía , Aprendizaje Automático
5.
BMC Neurol ; 24(1): 155, 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38714927

RESUMEN

BACKGROUND: Chronic lung and heart diseases are more likely to lead an intensive end point after stroke onset. We aimed to investigate characteristics and outcomes of endovascular thrombectomy (EVT) in patients with acute large vessel occlusion stroke (ALVOS) and identify the role of comorbid chronic cardiopulmonary diseases in ALVOS pathogenesis. METHODS: In this single-center retrospective study, 191 consecutive patients who underwent EVT due to large vessel occlusion stroke in neurological intensive care unit were included. The chronic cardiopulmonary comorbidities and several conventional stroke risk factors were assessed. The primary efficacy outcome was functional independence (defined as a mRS of 0 to 2) at day 90. The primary safety outcomes were death within 90 days and the occurrence of symptomatic intracranial hemorrhage(sICH). Univariate analysis was applied to evaluate the relationship between factors and clinical outcomes, and logistic regression model were developed to predict the prognosis of ALVOS. RESULTS: Endovascular therapy in ALVOS patients with chronic cardiopulmonary diseases, as compared with those without comorbidity, was associated with an unfavorable shift in the NHISS 24 h after EVT [8(4,15.25) versus 12(7.5,18.5), P = 0.005] and the lower percentage of patients who were functionally independent at 90 days, defined as a score on the modified Rankin scale of 0 to 2 (51.6% versus 25.4%, P = 0.000). There was no significant between-group difference in the frequency of mortality (12.1% versus 14.9%, P = 0.580) and symptomatic intracranial hemorrhage (13.7% versus 19.4%, P = 0.302) or of serious adverse events. Moreover, a prediction model showed that existence of cardiopulmonary comorbidities (OR = 0.456, 95%CI 0.209 to 0.992, P = 0.048) was independently associated with functional independence at day 90. CONCLUSIONS: EVT was safe in ALVOS patients with chronic cardiopulmonary diseases, whereas the unfavorable outcomes were achieved in such patients. Moreover, cardiopulmonary comorbidity had certain clinical predictive value for worse stroke prognosis.


Asunto(s)
Comorbilidad , Procedimientos Endovasculares , Trombectomía , Humanos , Masculino , Femenino , Anciano , Estudios Retrospectivos , Persona de Mediana Edad , Procedimientos Endovasculares/métodos , Trombectomía/métodos , Trombectomía/estadística & datos numéricos , Trombectomía/efectos adversos , Cardiopatías/epidemiología , Cardiopatías/complicaciones , Cardiopatías/cirugía , Anciano de 80 o más Años , Estudios de Cohortes , Enfermedades Pulmonares/epidemiología , Enfermedades Pulmonares/cirugía , Resultado del Tratamiento , Accidente Cerebrovascular Isquémico/cirugía , Accidente Cerebrovascular Isquémico/epidemiología , Accidente Cerebrovascular/cirugía , Accidente Cerebrovascular/epidemiología
6.
Lasers Surg Med ; 56(2): 218-225, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38105476

RESUMEN

OBJECTIVES: To investigate the wound healing of rabbit cornea following infrared laser irradiations at the wavelengths of 1.319 and 10.6 µm. MATERIALS AND METHODS: Twelve New Zealand rabbits were selected to establish a corneal injury model. The right and left eyes were irradiated with a neodymium-doped yttrium aluminum garnet laser at the wavelength of 1.319 µm (140 J/cm2 ) for 0.7 s and a CO2 laser at the wavelength of 10.6 µm (5.94 J/cm2 ) for 0.14 s, respectively. The incident spot diameter was 3 mm. Optical coherence tomography (OCT) was used to monitor injuries at 0 h, 0.5 h, 1 h, 3 h, 6 h, 12 h, 18 h, 24 h, 30 h, 36 h, 42 h, 48 h, 54 h, 60 h, 66 h, 3 d, 7 d, 14 d, 28 d, 3 m, and 6 m postexposure. Meanwhile, slit-lamp microscopy and histopathology were performed at 6 h, 24 h, 3 d, 7 d, 14 d, 28 d, 3 m, and 6 m postexposure. RESULTS: After the two types of infrared laser injuries, distinct white circular lesions on the corneal surface were directly observed. Deeper corneal injury, more severe edema, and faster migration of new epithelium were found for the wavelength of 1.319 µm, compared to the wavelength of 10.6 µm. CONCLUSIONS: OCT combined with histopathology and slit-lamp microscopy can clearly observe the dynamic process of corneal wound healing after infrared laser irradiation. The damage characteristics for the two different wavelengths were visibly different, but the whole wound healing process was similar. The obtained results may provide references for the diagnosis, treatment, and evaluation of laser-induced damages.


Asunto(s)
Lesiones de la Cornea , Láseres de Estado Sólido , Animales , Conejos , Córnea/diagnóstico por imagen , Córnea/cirugía , Cicatrización de Heridas , Luz , Láseres de Estado Sólido/uso terapéutico
7.
Proc Natl Acad Sci U S A ; 118(13)2021 03 30.
Artículo en Inglés | MEDLINE | ID: mdl-33753507

RESUMEN

Asymmetric cell division generates two daughter cells with distinct characteristics and fates. Positioning different regulatory and signaling proteins at the opposing ends of the predivisional cell produces molecularly distinct daughter cells. Here, we report a strategy deployed by the asymmetrically dividing bacterium Caulobacter crescentus where a regulatory protein is programmed to perform distinct functions at the opposing cell poles. We find that the CtrA proteolysis adaptor protein PopA assumes distinct oligomeric states at the two cell poles through asymmetrically distributed c-di-GMP: dimeric at the stalked pole and monomeric at the swarmer pole. Different polar organizing proteins at each cell pole recruit PopA where it interacts with and mediates the function of two molecular machines: the ClpXP degradation machinery at the stalked pole and the flagellar basal body at the swarmer pole. We discovered a binding partner of PopA at the swarmer cell pole that together with PopA regulates the length of the flagella filament. Our work demonstrates how a second messenger provides spatiotemporal cues to change the physical behavior of an effector protein, thereby facilitating asymmetry.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , División Celular Asimétrica , Proteínas Bacterianas/metabolismo , Caulobacter crescentus/fisiología , Caulobacter crescentus/citología , Caulobacter crescentus/metabolismo , GMP Cíclico/análogos & derivados , GMP Cíclico/metabolismo , Endopeptidasa Clp/metabolismo , Multimerización de Proteína , Proteolisis
8.
J Foot Ankle Surg ; 2024 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-38679411

RESUMEN

The present study was to determine the characteristics of the ankle skeletal structure in patients with talus Hepple V type. We conducted a retrospective study on the skeletal structure of the talus in 110 patients with Hepple V osteochondral lesions of the talus and in control participants. The radiographic measurements taken include the following: in the coronal plane - depth of talus frontal curvature, length of the lateral and medial malleolus; in the sagittal plane - radius and height of talus, angle of tibial lateral surface, tibiotalar sector, and vertical neck angle. The osteochondral lesion of the talus showed a significantly larger mean radius (mean ± SD, 21.4 ± 2.5 mm; p < .001) and height (mean ± SD, 26.0 ± 2.7 mm; p < .005). It also demonstrated a longer mean medial malleolus length (mean ± SD, 15.7 ± 2.4 mm; p < .005), a larger mean vertical neck angle (mean ± SD, 86.2 ± 5.4°; p < .050), and a greater mean tibial lateral surface angle (mean ± SD, 80.0 ± 4.5°; p < .001). And there was a greater mean frontal curvature depth (mean ± SD, 3.9 ± 0.6 mm; p < .005). Overall, this study found that patients with Hepple V osteochondral lesions of the talus had a larger vertical neck angle and tibial lateral surface angle, a longer talus radius and medial malleolus length, a higher talus height, and a deeper frontal curvature depth. STUDY DESIGNS: Retrospective Case-Control Study.

9.
Angew Chem Int Ed Engl ; : e202402184, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38750660

RESUMEN

Water electrolysis is one promising and eco-friendly technique for energy storage, yet its overall efficiency is hindered by the sluggish kinetics of oxygen evolution reaction (OER). Therefore, developing strategies to boost OER catalyst performance is crucial. With the advances in characterization techniques, an extensive phenomenon of surface structure evolution into an active amorphous layer was uncovered. Surface reconstruction in a controlled fashion was then proposed as an emerging strategy to elevate water oxidation efficiency. In this work, Cr substitution induces the reconstruction of NiFexCr2-xO4 during cyclic voltammetry (CV) conditioning by Cr leaching, which leads to a superior OER performance. The best-performed NiFe0.25Cr1.75O4 shows a ~1500 % current density promotion at overpotential η=300 mV, which outperforms many advanced NiFe-based OER catalysts. It is also found that their OER activities are mainly determined by Ni : Fe ratio rather than considering the contribution of Cr. Meanwhile, the turnover frequency (TOF) values based on redox peak and total mass were obtained and analysed, and their possible limitations in the case of NiFexCr2-xO4 are discussed. Additionally, the high activity and durability were further verified in a membrane electrode assembly (MEA) cell, highlighting its potential for practical large-scale and sustainable hydrogen gas generation.

10.
Small ; 19(34): e2301998, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37162443

RESUMEN

In order to overcome the limitations of supramolecular organic cages for their incomplete accessibility of active sites in the solid state and uneasy recyclability in liquid solution, herein a nitrogen-rich organic cage is rationally linked into framework systems and four isoreticular covalent organic frameworks (COFs), that is, Cage-TFB-COF, Cage-NTBA-COF, Cage-TFPB-COF, and Cage-TFPT-COF, are successfully synthesized. Structure determination reveals that they are all high-quality crystalline materials derived from the eclipsed packing of related isoreticular two-dimensional frameworks. Since the nitrogen-rich sites usually have a high affinity toward iodine species, iodine adsorption investigations are carried out and the results show that all of them display an enhancement in iodine adsorption capacities. Especially, Cage-NTBA-COF exhibits an iodine adsorption capacity of 304 wt%, 14-fold higher than the solid sample packed from the cage itself. The strong interactions between the nitrogen-rich sites and the adsorbed iodine species are revealed by spectral analyses. This work demonstrates that, utilizing the reticular chemistry strategy to extend the close-packed supramolecular organic cages into crystalline porous framework solids, their inherent properties can be greatly exploited for targeted applications.

11.
Small ; 19(44): e2303324, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37391273

RESUMEN

Converting CO2 into value-added chemicals to solve the issues caused by carbon emission is promising but challenging. Herein, by embedding metal ions (Co2+ , Ni2+ , Cu2+ , and Zn2+ ) into an imidazole-linked robust photosensitive covalent organic framework (PyPor-COF), effective photocatalysts for CO2 conversion are rationally designed and constructed. Characterizations display that all of the metallized PyPor-COFs (M-PyPor-COFs) display remarkably high enhancement in their photochemical properties. Photocatalysis reactions reveal that the Co-metallized PyPor-COF (Co-PyPor-COF) achieves a CO production rate as high as up to 9645 µmol g-1 h-1 with a selectivity of 96.7% under light irradiation, which is more than 45 times higher than that of the metal-free PyPor-COF, while Ni-metallized PyPor-COF (Ni-PyPor-COF) can further tandem catalyze the generated CO to CH4 with a production rate of 463.2 µmol g-1 h-1 . Experimental analyses and theory calculations reveal that their remarkable performance enhancement on CO2 photoreduction should be attributed to the incorporated metal sites in the COF skeleton, which promotes the adsorption and activation of CO2 and the desorption of generated CO and even reduces the reaction energy barrier for the formation of different intermediates. This work demonstrates that by metallizing photoactive COFs, effective photocatalysts for CO2 conversion can be achieved.

12.
Small ; 19(26): e2302295, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37194952

RESUMEN

Although the electrocatalytic nitrate reduction reaction (NO3 - RR) is an attractive NH3 synthesis route, it suffers from low yield due to the lack of efficient catalysts. Here, this work reports a novel grain boundary (GB)-rich Sn-Cu catalyst, derived from in situ electroreduction of Sn-doped CuO nanoflower, for effectively electrochemical converting NO3 - to NH3 . The optimized Sn1% -Cu electrode achieves a high NH3 yield rate of 1.98 mmol h-1 cm-2 with an industrial-level current density of -425 mA cm-2 at -0.55 V versus a reversible hydrogen electrode (RHE) and a maximum Faradaic efficiency of 98.2% at -0.51 V versus RHE, outperforming the pure Cu electrode. In situ Raman and attenuated total reflection Fourier transform infrared spectroscopies reveal the reaction pathway of NO3 - RR to NH3 by monitoring the adsorption property of reaction intermediates. Density functional theory calculations clarify that the high-density GB active sites and the competitive hydrogen evolution reaction (HER) suppression induced by Sn doping synergistically promote highly active and selective NH3 synthesis from NO3 - RR. This work paves an avenue for efficient NH3 synthesis over Cu catalyst by in situ reconstruction of GB sites with heteroatom doping.

13.
Biotechnol Bioeng ; 120(11): 3288-3298, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37534801

RESUMEN

Current manufacturing and development processes for therapeutic monoclonal antibodies demand increasing volumes of analytical testing for both real-time process controls and high-throughput process development. The feasibility of using Raman spectroscopy as an in-line product quality measuring tool has been recently demonstrated and promises to relieve this analytical bottleneck. Here, we resolve time-consuming calibration process that requires fractionation and preparative experiments covering variations of product quality attributes (PQAs) by engineering an automation system capable of collecting Raman spectra on the order of hundreds of calibration points from two to three stock seed solutions differing in protein concentration and aggregate level using controlled mixing. We used this automated system to calibrate multi-PQA models that accurately measured product concentration and aggregation every 9.3 s using an in-line flow-cell. We demonstrate the application of a nonlinear calibration model for monitoring product quality in real-time during a biopharmaceutical purification process intended for clinical and commercial manufacturing. These results demonstrate potential feasibility to implement quality monitoring during GGMP manufacturing as well as to increase chemistry, manufacturing, and controls understanding during process development, ultimately leading to more robust and controlled manufacturing processes.

14.
Langmuir ; 39(17): 6240-6248, 2023 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-37083475

RESUMEN

In this work, an urchin-like Ni@Ni2P@NiCoP (Ni@NP@NCP) composite was prepared on nickel foam by a simple hydrothermal treatment process. Using the prepared NiO nanosheets as templates, the NiCo precursor was prepared in the presence of three solvothermal systems of water/dimethylformamide (DMF)/dimethyl sulfoxide (DMSO) by the hydrothermal process. After mixing and calcining with sodium hypophosphite under a nitrogen atmosphere at a high temperature for phosphating, an urchin-like Ni@NP@NCP(F/SO/H) nanostructured catalyst was obtained with superior hydrogen evolution and oxygen evolution performance. To further explore their efficiency in seawater splitting. Ni@NP@NCP(F/SO/H) composites were used as the cathode and anode of an electrolytic cell, which delivered 1.822 V potential at 300 mA cm-2 in simulated seawater (1 M KOH and 0.5 M NaCl). This may provide an effective way of developing clean energy.

15.
Macromol Rapid Commun ; 44(18): e2300216, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37335892

RESUMEN

Poly(dimethyl siloxane) (PDMS) elastomers play a significant role in smart materials, actuators, and flexible electronics. However, current PDMS lacks adhesion abilities and intelligent responsive properties, which limit its further application. In this study, the polydimethylsiloxane-ureidopyrimidinone impact hardening polymer (PDMS-UI) composites are manufactured by a dual cross-linking compositing tactic. PDMS, a chemically stable cross-linked network, acts as a framework owing to its excellent mechanical strength, whereas UI, a reversible dynamic physically cross-linked network with quadruple hydrogen bonding, endows the PDMS-UI with excellent self-healing ability (efficiency > 90%) and energy absorption (75.23%). Impressively, owing to multivalent hydrogen bonds, the PDMS-UI exhibits superior adhesion performance: the adhesion strength on various substrates exceed 150 kPa and that on the Ferrum substrate reaches 570 kPa. These outstanding properties make the PDMS-UI a potential candidate for application in both well-developed fields, such as, wearable protective materials, artificial skin and soft robotics.


Asunto(s)
Materiales Inteligentes , Polímeros/química , Elastómeros/química , Temperatura , Enlace de Hidrógeno
16.
Lasers Surg Med ; 55(9): 846-852, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37655759

RESUMEN

OBJECTIVES: Previous report shows that corneal spot size is an important influence factor on damage threshold induced by supercontinumm (SC) source. However, damage thresholds were determined for the spot size of only 0.37 mm due to the low output of the employed SC source at that time. The objectives of this study are to determine the lowest possible corneal damage threshold at a large corneal spot size using a more powerful SC source and provide data for the future possible refinements of laser safety standards. MATERIALS AND METHODS: A series of experiments was conducted in the New Zealand white rabbit model to determine the corneal damage threshold induced by a 900-2000 nm SC source, with corneal 1/e beam diameter of about 1.2 mm. Slit-lamp biomicroscope was employed to reveal the corneal damage characteristics. By employing the action spectra determined through the analysis of current laser safety guidelines and standards, the effective damage threshold could be calculated. RESULTS: The determined damage threshold given in terms of the peak radiant exposure for the exposure duration of 0.14 s was 44.3 J/cm2 . At threshold level, corneal damages involved the epithelium and the shallower stroma. The safety factor between the effective damage threshold and the corresponding maximum permissible exposure (MPE) was about 45. CONCLUSIONS: Present corneal MPEs in the wavelength range of 700-1200 nm may be conservative and corneal damage thresholds for the infrared A wavelengths should be determined in future studies.

17.
Proc Natl Acad Sci U S A ; 117(25): 13937-13944, 2020 06 23.
Artículo en Inglés | MEDLINE | ID: mdl-32513734

RESUMEN

Superresolution fluorescence microscopy and cryogenic electron tomography (CET) are powerful imaging methods for exploring the subcellular organization of biomolecules. Superresolution fluorescence microscopy based on covalent labeling highlights specific proteins and has sufficient sensitivity to observe single fluorescent molecules, but the reconstructions lack detailed cellular context. CET has molecular-scale resolution but lacks specific and nonperturbative intracellular labeling techniques. Here, we describe an imaging scheme that correlates cryogenic single-molecule fluorescence localizations with CET reconstructions. Our approach achieves single-molecule localizations with an average lateral precision of 9 nm, and a relative registration error between the set of localizations and CET reconstruction of ∼30 nm. We illustrate the workflow by annotating the positions of three proteins in the bacterium Caulobacter crescentus: McpA, PopZ, and SpmX. McpA, which forms a part of the chemoreceptor array, acts as a validation structure by being visible under both imaging modalities. In contrast, PopZ and SpmX cannot be directly identified in CET. While not directly discernable, PopZ fills a region at the cell poles that is devoid of electron-dense ribosomes. We annotate the position of PopZ with single-molecule localizations and confirm its position within the ribosome excluded region. We further use the locations of PopZ to provide context for localizations of SpmX, a low-copy integral membrane protein sequestered by PopZ as part of a signaling pathway that leads to an asymmetric cell division. Our correlative approach reveals that SpmX localizes along one side of the cell pole and its extent closely matches that of the PopZ region.


Asunto(s)
Proteínas Bacterianas/metabolismo , Caulobacter crescentus/ultraestructura , Imagen Individual de Molécula/métodos , Proteínas Bacterianas/ultraestructura , Caulobacter crescentus/metabolismo , Tomografía con Microscopio Electrónico/métodos , Microscopía Fluorescente/métodos , Transporte de Proteínas
18.
BMC Med Inform Decis Mak ; 23(1): 214, 2023 10 13.
Artículo en Inglés | MEDLINE | ID: mdl-37833709

RESUMEN

BACKGROUND: The most prevalent mesenchymal-derived gastrointestinal cancers are gastric stromal tumors (GSTs), which have the highest incidence (60-70%) of all gastrointestinal stromal tumors (GISTs). However, simple and effective diagnostic and screening methods for GST remain a great challenge at home and abroad. This study aimed to build a GST early warning system based on a combination of machine learning algorithms and routine blood, biochemical and tumour marker indicators. METHODS: In total, 697 complete samples were collected from four hospitals in Gansu Province, including 42 blood indicators from 318 pretreatment GST patients, 180 samples of gastric polyps and 199 healthy individuals. In this study, three algorithms, gradient boosting machine (GBM), random forest (RF), and logistic regression (LR), were chosen to build GST prediction models for comparison. The performance and stability of the models were evaluated using two different validation techniques: 5-fold cross-validation and external validation. The DeLong test assesses significant differences in AUC values by comparing different ROC curves, the variance and covariance of the AUC value. RESULTS: The AUC values of both the GBM and RF models were higher than those of the LR model, and this difference was statistically significant (P < 0.05). The GBM model was considered to be the optimal model, as a larger area was enclosed by the ROC curve, and the axes indicated robust model classification performance according to the accepted model discriminant. Finally, the integration of 8 top-ranked blood indices was proven to be able to distinguish GST from gastric polyps and healthy people with sensitivity, specificity and area under the curve of 0.941, 0.807 and 0.951 for the cross-validation set, respectively. CONCLUSION: The GBM demonstrated powerful classification performance and was able to rapidly distinguish GST patients from gastric polyps and healthy individuals. This identification system not only provides an innovative strategy for the diagnosis of GST but also enables the exploration of hidden associations between blood parameters and GST for subsequent studies on the prevention and disease surveillance management of GST. The GST discrimination system is available online for free testing of doctors and high-risk groups at https://jzlyc.gsyy.cn/bear/mobile/index.html .


Asunto(s)
Algoritmos , Neoplasias , Humanos , Biopsia , Biomarcadores de Tumor , Manejo de la Enfermedad
19.
J Struct Biol ; 214(3): 107881, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35811036

RESUMEN

Cryogenic correlative light and electron microscopy (cryo-CLEM) seeks to leverage orthogonal information present in two powerful imaging modalities. While recent advances in cryogenic electron microscopy (cryo-EM) allow for the visualization and identification of structures within cells at the nanometer scale, information regarding the cellular environment, such as pH, membrane potential, ionic strength, etc., which influences the observed structures remains absent. Fluorescence microscopy can potentially be used to reveal this information when specific labels, known as fluorescent biosensors, are used, but there has been minimal use of such biosensors in cryo-CLEM to date. Here we demonstrate the applicability of one such biosensor, the fluorescent protein roGFP2, for cryo-CLEM experiments. At room temperature, the ratio of roGFP2 emission brightness when excited at 425 nm or 488 nm is known to report on the local redox potential. When samples containing roGFP2 are rapidly cooled to 77 K in a manner compatible with cryo-EM, the ratio of excitation peaks remains a faithful indicator of the redox potential at the time of freezing. Using purified protein in different oxidizing/reducing environments, we generate a calibration curve which can be used to analyze in situ measurements. As a proof-of-principle demonstration, we investigate the oxidation/reduction state within vitrified Caulobacter crescentus cells. The polar organizing protein Z (PopZ) localizes to the polar regions of C. crescentus where it is known to form a distinct microdomain. By expressing an inducible roGFP2-PopZ fusion we visualize individual microdomains in the context of their redox environment.


Asunto(s)
Frío , Electrones , Microscopía por Crioelectrón/métodos , Microscopía Electrónica , Microscopía Fluorescente/métodos
20.
Eur J Neurosci ; 56(2): 3991-4008, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35560852

RESUMEN

Spinal cord injury (SCI) damages sensory systems, producing chronic neuropathic pain that is resistant to medical treatment. The specific mechanisms underlying SCI-induced neuropathic pain (SCI-NP) remain unclear, and protein biomarkers have not yet been integrated into diagnostic screening. To better understand the host molecular pathways involved in SCI-NP, we used the bioinformatics method, the PubMed database and bioinformatics methods to identify target genes and their associated pathways. We reviewed 2504 articles on the regulation of SCI-NP and used the text mining of PubMed database abstracts to determine associations among 12 pathways and networks. Based on this method, we identified two central genes in SCI-NP: interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α). Adult male Sprague-Dawley rats were used to build the SCI-NP models. The threshold for paw withdrawal was significantly reduced in the SCI group, and TLR4 was activated in microglia after SCI. Enzyme-linked immunosorbent assay(ELISA) analysis of TNF-α and IL-6 levels was significantly higher in the SCI group than in the sham group. Western blot showed that expressions of the TLR4/MyD88/NF-κB inflammatory pathway protein increased dramatically in the SCI group. Using the TLR4 inhibitor TAK-242, the pain threshold and expressions of inflammatory factors and proteins of the proteins of the inflammatory signal pathway were reversed, TLR4 in microglia was suppressed, suggesting that SCI-NP was related to neuroinflammation mediated by the TLR4 signalling pathway. In conclusion, we found that TNF-α and IL-6 were the neuroinflammation-related genes involved in SCI-NP that can be alleviated by inhibiting the inflammatory pathway upstream of the TLR4/MyD88/NF-κB inflammatory pathway.


Asunto(s)
Neuralgia , Traumatismos de la Médula Espinal , Animales , Interleucina-6/genética , Interleucina-6/metabolismo , Masculino , Factor 88 de Diferenciación Mieloide/metabolismo , FN-kappa B/metabolismo , Neuralgia/genética , Neuralgia/metabolismo , Ratas , Ratas Sprague-Dawley , Médula Espinal/metabolismo , Traumatismos de la Médula Espinal/complicaciones , Traumatismos de la Médula Espinal/genética , Traumatismos de la Médula Espinal/metabolismo , Receptor Toll-Like 4/genética , Receptor Toll-Like 4/metabolismo , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismo
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