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1.
J Bacteriol ; 206(3): e0042923, 2024 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-38391161

RESUMEN

Actinobacillus pleuropneumoniae is an important respiratory pathogen that can cause porcine contagious pleuropneumonia (PCP), resulting in significant economic losses in swine industry. Microorganisms are subjected to drastic changes in environmental osmolarity. In order to alleviate the drastic rise or fall of osmolarity, cells activate mechanosensitive channels MscL and MscS through tension changes. MscL not only regulates osmotic pressure but also has been reported to secrete protein and uptake aminoglycoside antibiotic. However, MscL and MscS, as the most common mechanosensitive channels, have not been characterized in A. pleuropneumoniae. In this study, the osmotic shock assay showed that MscL increased sodium adaptation by regulating cell length. The results of MIC showed that deletion of mscL decreased the sensitivity of A. pleuropneumoniae to multiple antibiotics, while deletion of mscS rendered A. pleuropneumoniae hypersensitive to penicillin. Biofilm assay demonstrated that MscL contributed the biofilm formation but MscS did not. The results of animal assay showed that MscL and MscS did not affect virulence in vivo. In conclusion, MscL is essential for sodium hyperosmotic tolerance, biofilm formation, and resistance to chloramphenicol, erythromycin, penicillin, and oxacillin. On the other hand, MscS is only involved in oxacillin resistance.IMPORTANCEBacterial resistance to the external environment is a critical function that ensures the normal growth of bacteria. MscL and MscS play crucial roles in responding to changes in both external and internal environments. However, the function of MscL and MscS in Actinobacillus pleuropneumoniae has not yet been reported. Our study shows that MscL plays a significant role in osmotic adaptation, antibiotic resistance, and biofilm formation of A. pleuropneumoniae, while MscS only plays a role in antibiotic resistance. Our findings provide new insights into the functional characteristics of MscL and MscS in A. pleuropneumoniae. MscL and MscS play a role in antibiotic resistance and contribute to the development of antibiotics for A. pleuropneumoniae.


Asunto(s)
Actinobacillus pleuropneumoniae , Enfermedades de los Porcinos , Animales , Porcinos , Actinobacillus pleuropneumoniae/genética , Actinobacillus pleuropneumoniae/metabolismo , Antibacterianos/farmacología , Antibacterianos/metabolismo , Virulencia , Oxacilina , Sodio/metabolismo , Enfermedades de los Porcinos/microbiología
2.
Angew Chem Int Ed Engl ; 62(42): e202310245, 2023 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-37632702

RESUMEN

Chemical biomarkers in the central nervous system can provide valuable quantitative measures to gain insight into the etiology and pathogenesis of neurological diseases. Glutamate, one of the most important excitatory neurotransmitters in the brain, has been found to be upregulated in various neurological disorders, such as traumatic brain injury, Alzheimer's disease, stroke, epilepsy, chronic pain, and migraines. However, quantitatively monitoring glutamate release in situ has been challenging. This work presents a novel class of flexible, miniaturized probes inspired by biofuel cells for monitoring synaptically released glutamate in the nervous system. The resulting sensors, with dimensions as low as 50 by 50 µm, can detect real-time changes in glutamate within the biologically relevant concentration range. Experiments exploiting the hippocampal circuit in mice models demonstrate the capability of the sensors in monitoring glutamate release via electrical stimulation using acute brain slices. These advances could aid in basic neuroscience studies and translational engineering, as the sensors provide a diagnostic tool for neurological disorders. Additionally, adapting the biofuel cell design to other neurotransmitters can potentially enable the detailed study of the effect of neurotransmitter dysregulation on neuronal cell signaling pathways and revolutionize neuroscience.

3.
Mutagenesis ; 37(1): 34-43, 2022 04 02.
Artículo en Inglés | MEDLINE | ID: mdl-34791379

RESUMEN

Obese subjects have a high baseline of genotoxic stress, but the underlying mechanism is poorly understood. Given that obesity is associated with high bile acids (BA) and low folate, we aimed to determine the interactive effect of folate deficient or supplementation to the genotoxicity and cytotoxicity of BA in human colon and liver cells. NCM460 and L-02 cells were cultured in folate-deficient (22.6 nM) and replete (2260 nM) Roswell Park Memorial Institute (RPMI)-1640 medium with or without 50 µM deoxycholic acid (DCA) or lithocholic acid (LCA) for 7 days. Moreover, these cells were cultured in folate supplemented (5.65, 11.3 and 22.6 µM) and standard (2.26 µM) medium with 200 µM DCA or LCA for 7 days. Genotoxicity and cytotoxicity were measured using the cytokinesis-block micronucleus cytome assay. Our results showed that under folate-replete condition, 50 µM DCA or LCA significantly increased the rate of micronuclei (MN) in NCM460 and L-02 cells. Significantly, the MN-inducing effect of 50 µM DCA or LCA was further enhanced by folate deficiency. Interestingly, folate supplementation exerted a dose-dependent manner to significantly decrease the rates of MN, nucleoplasmic bridges, nuclear buds, apoptosis, and necrosis induced by 200 µM DCA or LCA in NCM460 and L-02 cells. In conclusion, the genotoxicity of moderate BA (50 µM) was exacerbated by folate deficiency and folate supplementation could efficiently protect cells against the genotoxicity and cytotoxicity of high BA (200 µM).


Asunto(s)
Ácidos y Sales Biliares , Daño del ADN , Colon , Ácido Fólico/farmacología , Humanos , Hígado , Pruebas de Micronúcleos/métodos
4.
Brain ; 144(9): 2759-2770, 2021 10 22.
Artículo en Inglés | MEDLINE | ID: mdl-34428276

RESUMEN

The molecular link between amyloid-ß plaques and neurofibrillary tangles, the two pathological hallmarks of Alzheimer's disease, is still unclear. Increasing evidence suggests that amyloid-ß peptide activates multiple regulators of cell cycle pathways, including transcription factors CDKs and E2F1, leading to hyperphosphorylation of tau protein. However, the exact pathways downstream of amyloid-ß-induced cell cycle imbalance are unknown. Here, we show that PAX6, a transcription factor essential for eye and brain development which is quiescent in adults, is increased in the brains of patients with Alzheimer's disease and in APP transgenic mice, and plays a key role between amyloid-ß and tau hyperphosphorylation. Downregulation of PAX6 protects against amyloid-ß peptide-induced neuronal death, suggesting that PAX6 is a key executor of the amyloid-ß toxicity pathway. Mechanistically, amyloid-ß upregulates E2F1, followed by the induction of PAX6 and c-Myb, while Pax6 is a direct target for both E2F1 and its downstream target c-Myb. Furthermore, PAX6 directly regulates transcription of GSK-3ß, a kinase involved in tau hyperphosphorylation and neurofibrillary tangles formation, and its phosphorylation of tau at Ser356, Ser396 and Ser404. In conclusion, we show that signalling pathways that include CDK/pRB/E2F1 modulate neuronal death signals by activating downstream transcription factors c-Myb and PAX6, leading to GSK-3ß activation and tau pathology, providing novel potential targets for pharmaceutical intervention.


Asunto(s)
Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/toxicidad , Factor de Transcripción PAX6/metabolismo , Fragmentos de Péptidos/toxicidad , Proteínas tau/metabolismo , Enfermedad de Alzheimer/patología , Animales , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Encéfalo/patología , Células Cultivadas , Células HEK293 , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Fosforilación/efectos de los fármacos , Fosforilación/fisiología , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología
5.
Phys Chem Chem Phys ; 23(14): 8784-8791, 2021 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-33876037

RESUMEN

Compared to the Haber-Bosch process, the electrochemical nitrogen reduction reaction (NRR) can convert N2 into NH3 under ambient conditions, and thus has attracted considerable attention in recent years. However, it remains a challenge to fabricate NRR catalysts with high faradaic efficiency and yield rate. In this work, by systematic first-principles calculations, we investigate the structure, stability and catalytic performance of single metal atoms anchored on porous monolayer C9N4 (M@C9N4) for the electrochemical NRR. A total of 25 transition metals (Sc-Zn, Zr-Mo, Ru-Ag, Hf-Au) were explored, and we screened out four promising systems, i.e., Nb, Ta, Re and W@C9N4, which not only exhibit high catalytic activity with low limiting potentials of -0.3, -0.42, -0.49 and -0.25 V, respectively, but also have superior selectivity that suppresses the competitive hydrogen evolution reaction. The physical origin lies in the coupling between the d orbitals of the transition metals and the 2π* orbital of N2, which activates the N2 molecule and facilitates the reduction process. Our proposed systems are kinetically and thermodynamically stable, which may shed light on future design and fabrication of high-efficiency single atom catalysts for various technologically important chemical reactions.

6.
BMC Pulm Med ; 20(1): 129, 2020 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-32381057

RESUMEN

BACKGROUND: Although typical and atypical CT image findings of COVID-19 are reported in current studies, the CT image features of COVID-19 overlap with those of viral pneumonia and other respiratory diseases. Hence, it is difficult to make an exclusive diagnosis. METHODS: Thirty confirmed cases of COVID-19 and forty-three cases of other aetiology or clinically confirmed non-COVID-19 in a general hospital were included. The clinical data including age, sex, exposure history, laboratory parameters and aetiological diagnosis of all patients were collected. Seven positive signs (posterior part/lower lobe predilection, bilateral involvement, rounded GGO, subpleural bandlike GGO, crazy-paving pattern, peripheral distribution, and GGO +/- consolidation) from significant COVID-19 CT image features and four negative signs (only one lobe involvement, only central distribution, tree-in-bud sign, and bronchial wall thickening) from other non-COVID-19 pneumonia were used. The scoring analysis of CT features was compared between the two groups (COVID-19 and non-COVID-19). RESULTS: Older age, symptoms of diarrhoea, exposure history related to Wuhan, and a lower white blood cell and lymphocyte count were significantly suggestive of COVID-19 rather than non-COVID-19 (p < 0.05). The receiver operating characteristic (ROC) curve of the combined CT image features analysis revealed that the area under the curve (AUC) of the scoring system was 0.854. These cut-off values yielded a sensitivity of 56.67% and a specificity of 95.35% for a score > 4, a sensitivity of 100% and a specificity of 23.26% for a score > 0, and a sensitivity of 86.67% and a specificity of 67.44% for a score >  2. CONCLUSIONS: With a simple and practical scoring system based on CT imaging features, we can make a hierarchical diagnosis of COVID-19 and non-COVID-19 with different management suggestions.


Asunto(s)
Betacoronavirus , Infecciones por Coronavirus/diagnóstico por imagen , Neumonía Viral/diagnóstico por imagen , Adulto , COVID-19 , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pandemias , SARS-CoV-2 , Tomografía Computarizada por Rayos X
7.
Blood Purif ; 48(1): 1-9, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30763936

RESUMEN

BACKGROUND: Central venous catheter (CVC) is commonly used to provide access for hemodialysis (HD) when arteriovenous access is not available. The misplacement of CVC into azygos vein (AV) is a rare but a potential serious complication. Previous reports communicated the opinion that left-sided catheterization predisposed to AV misplacement, but these reports concentrated on peripherally inserted CVCs, placed for indications rather than HD. Unintended AV misplacement of HD catheters (HDCs) has not been well studied. We seek to investigate factors associated with inadvertent AV miscannulation during HDC placement. METHODS: We are to present a case of unintentional misplacement of a tunneled HD catheter (tHDC) into the azygos arch from right internal jugular vein (RIJV) despite real-time fluoroscopy guidance. Additionally, we have undertaken a systematic literature search in Pubmed to study the anatomical and other factors related to unintended AV misposition in HD setting. RESULTS: From 2005 to August 31, 2018, a total of 11 articles containing 16 cases of misplacement of HDCs into AV were identified. Of the 17 cases of unintentional AV misposition including ours, the majority of the misguided HDCs (94.1%, 16/17) were tHDCs and only 1 case was related to a temporary (non-tunneled) catheter. Most catheter misplacements (88.2%, 15/17) were performed without real-time radiological guidance. The reported incidence of inadvertent AV cannulation from different institutions varied between 0.6% and 3.8%. Among the 16 misplaced tHDCs, the rates of AV misposition that arose from RIJV and left internal jugular vein (LIJV) insertion are even at 50%. CONCLUSIONS: Based upon anatomical and case studies, we have found that AV may join posterior aspect of superior vena cava at different directions and levels. Hence, this might explain why AV misplacement might occur whether an HDC is inserted from the LIJV or RIJV approach. By raising the awareness of this potential complication and how we may minimize it, we hope to reduce the future complication of AV misposition.


Asunto(s)
Vena Ácigos , Cateterismo Venoso Central , Catéteres Venosos Centrales , Errores Médicos , Diálisis Renal , Anciano , Vena Ácigos/cirugía , Cateterismo Venoso Central/métodos , Cateterismo Venoso Central/normas , Catéteres Venosos Centrales/normas , Humanos , Venas Yugulares/cirugía , Fallo Renal Crónico/complicaciones , Fallo Renal Crónico/terapia , Masculino , Radiografía Torácica , Diálisis Renal/normas
8.
Phys Chem Chem Phys ; 19(43): 29647-29652, 2017 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-29085920

RESUMEN

Topological phases, especially topological crystalline insulators (TCIs), have been intensively explored and observed experimentally in three-dimensional (3D) materials. However, two-dimensional (2D) films are explored much less than 3D TCIs, and even 2D topological insulators. Based on ab initio calculations, here we investigate the electronic and topological properties of 2D PbTe(001) few-layer films. The monolayer and trilayer PbTe are both intrinsic 2D TCIs with a large band gap reaching 0.27 eV, indicating a high possibility for room-temperature observation of quantized conductance. The origin of the TCI phase can be attributed to the px,y-pz band inversion, which is determined by the competition of orbital hybridization and the quantum confinement effect. We also observe a semimetal-TCI-normal insulator transition under biaxial strains, whereas a uniaxial strain leads to Z2 nontrivial states. In particular, the TCI phase of a PbTe monolayer remains when epitaxially grown on a NaI semiconductor substrate. Our findings on the controllable quantum states with sizable band gaps present an ideal platform for realizing future topological quantum devices with ultralow dissipation.

9.
Nanoscale ; 16(6): 2834-2846, 2024 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-38291996

RESUMEN

Biosensors are widely used in various applications, from medical diagnostics to environmental monitoring. Their widespread and continuous use necessitates regeneration methods to ensure cost-effectiveness and sustainability. In the realm of advancing human-centric bioelectronics for continuous monitoring, employing these sensors for real-time, in situ detection of biomarkers presents a considerable challenge. This mini-review examines diverse strategies utilized for the regeneration of biosensors, categorizing them based on their underlying mechanisms and discussing representative works. We explore methods ranging from surface engineering/re-functionalization, chemical treatments, allosteric regulation of bioreceptors, to manipulations of electric/magnetic fields, highlighting their working principles and exemplary studies. The advantages of each method, such as simplicity, high regeneration efficiency, and versatility, are discussed alongside their challenges, including degradation over cycles, limited applicability, and potential damage to sensors. As the demand for continuous and real-time biosensing escalates, the development of efficient and reliable regeneration strategies becomes essential. This mini-review offers an overview of the current landscape of biosensor regeneration, aiming to guide future research and innovations in this area.


Asunto(s)
Técnicas Biosensibles , Humanos , Técnicas Biosensibles/métodos , Biomarcadores , Regeneración
10.
Quant Imaging Med Surg ; 14(2): 1591-1601, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38415124

RESUMEN

Background: Gadolinium ethoxybenzyl-diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) has shown potential in reflecting the hepatic function alterations in nonalcoholic steatohepatitis (NASH). The purpose of this study was to evaluate whether Gd-EOB-DTPA combined with water-specific T1 (wT1) mapping can be used to detect liver inflammation in the early-stage of NASH in rats. Methods: In this study, 54 rats with methionine- and choline-deficient (MCD) diet-induced NASH and 10 normal control rats were examined. A multiecho variable flip angle gradient echo (VFA-GRE) sequence was performed and repeated 40 times after the injection of Gd-EOB-DTPA. The wT1 of the liver and the reduction rate of wT1 (rrT1) were calculated. All rats were histologically evaluated and grouped according to the NASH Clinical Research Network scoring system. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect the expression of Gd-EOB-DTPA transport genes. Analysis of variance and least significant difference tests were used for multiple comparisons of quantitative results between all groups. Multiple regression analysis was applied to identify variables associated with precontrast wT1 (wT1pre), and receiver operating characteristic (ROC) analysis was performed to assess the diagnostic performance. Results: The rats were grouped according to inflammatory stage (G0 =4, G1 =15, G2 =12, G3 =23) and fibrosis stage (F0 =26, F1 =19, F2 =9). After the infusion of Gd-EOB-DTPA, the rrT1 showed significant differences between the control and NASH groups (P<0.05) but no difference between the different inflammation and fibrosis groups at any time points. The areas under curve (AUCs) of rrT1 at 10, 20, and 30 minutes were only 0.53, 0.58, and 0.61, respectively, for differentiating between low inflammation grade (G0 + G1) and high inflammation grade (G2 + G3). The MRI findings were verified by qRT-PCR examination, in which the Gd-EOB-DTPA transporter expressions showed no significant differences between any inflammation groups. Conclusions: The wT1 mapping quantitative method combined with Gd-EOB-DTPA was not capable of discerning the inflammation grade in a rat model of early-stage NASH.

11.
Artículo en Inglés | MEDLINE | ID: mdl-36674151

RESUMEN

Based on the driving force-pressure-state-impact-response (DPSIR) model, a comprehensive evaluation index system is constructed. The index weight is determined by the combination weighting method in combination with the data of 2010-2019. The TOPSIS model is used to comprehensively analyze the water resource carrying capacity of Zhengzhou as the central city in China with a developed economy and relatively short water resources. The study results are as follows. (1) During the sample period, the comprehensive evaluation value of water resources carrying capacity of Zhengzhou increases from 0.4183 in 2010 to 0.5560 in 2019, with an overall fluctuating rise. Simultaneously, the water resource carrying capacity grade improves from Grade III (normal carrying capacity) to Grade II (good carrying capacity). (2) The contribution of each subsystem to the comprehensive evaluation value increases year by year. Among them, S subsystem and I subsystem make the largest contribution to the comprehensive carrying capacity. R subsystem makes a relatively stable contribution to the overall carrying capacity. Affected by GDP growth rate and uneven temporal-spatial distribution of water resources in Zhengzhou, the D subsystem and P subsystem of water resource carrying capacities show the fluctuating change. Finally, based on the above conclusions, this paper puts forward the countermeasures and suggestions to improve the level of water resource carrying capacity of Zhengzhou.


Asunto(s)
Conservación de los Recursos Naturales , Recursos Hídricos , Conservación de los Recursos Naturales/métodos , Ciudades , Urbanización , China
12.
Sci Rep ; 13(1): 20084, 2023 11 16.
Artículo en Inglés | MEDLINE | ID: mdl-37973924

RESUMEN

The pandemic of COVID-19 was a major public health events and had a deeply impact on the healthcare acquired by patients with inflammatory bowel disease (IBD). The purpose of this study was to evaluate the long-term impacts on healthcare service in Chinese IBD patients under the dynamic zero-COVID strategy. The study was performed in the Inflammatory Bowel Disease Quality of Care Centers in mainland China in 2021. The data about the healthcare was collected by a 44-item questionnaire. Totally 463 were from ulcerative colitis (UC) patients and 538 from Crohn's disease (CD) patients were included in the study. The pandemic impacted 37.5% patients on their treatment, and the biggest problem was unable to follow up timely (77.9%). There was a significant increase in healthcare costs in CD (P < 0.001) and no significant change in UC (P = 0.14) after the outbreak. Both UC and CD had an increase in the frequency of outpatient visits (UC 5.07 vs. 4.54, P = 0.001; CD 6.30 vs. 5.76, P = 0.002), and hospitalizations (UC 1.30 vs. 1.02, P < 0.001; CD 3.55 vs. 2.78, P < 0.001). The hospitalization rate in UC reduced slightly (40.2% vs. 42.8%, P = 0.423) after the outbreak, but it significantly increased in CD (75.8% vs. 67.8%, P = 0.004). The rate of biologics had significant increased (UC 11.2% vs. 17.7%, P = 0.005; CD 53.2% vs. 71.0%, P < 0.001). Besides, the proportion of people using telemedicine also increased from 41.6% to 55.1% (P < 0.001). However, 82.8% patients still preferred face-to-face visits. Recurrent outbreaks and the regular pandemic prevention and control policy had a long-term impact on medical care service for IBD patients. The preferred mode of healthcare was still face-to-face visit. It will be a long way to go in the construction of telemedicine in China.


Asunto(s)
Colitis Ulcerosa , Enfermedad de Crohn , Atención a la Salud , Enfermedades Inflamatorias del Intestino , Humanos , Colitis Ulcerosa/epidemiología , Enfermedad de Crohn/epidemiología , Estudios Transversales , Pueblos del Este de Asia , Costos de la Atención en Salud , Enfermedades Inflamatorias del Intestino/epidemiología , Enfermedades Inflamatorias del Intestino/terapia , Pandemias , COVID-19
13.
ACS Appl Mater Interfaces ; 15(19): 22892-22902, 2023 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-37154428

RESUMEN

Ocular formulations should provide an effective antibiotic concentration at the site of infection to treat bacterial eye infections. However, tears and frequent blinking accelerate the drug clearance rate and limit drug residence time on the ocular surface. This study describes a biological adhesion reticulate structure (BNP/CA-PEG) consisting of antibiotic-loaded bioadhesion nanoparticles (BNP/CA), with an average 500-600 nm diameter, and eight-arm NH2-PEG-NH2 for local and extended ocular drug delivery. This retention-prolonging effect is a function of the Schiff base reaction between groups on the surface of BNP and amidogen on PEG. BNP/CA-PEG showed significantly higher adhesion properties and better treatment efficacy in an ocular rat model with conjunctivitis in comparison to non-adhesive nanoparticles, BNP, or free antibiotics. Both in vivo safety experiment and in vitro cytotoxicity test verified the biocompatibility and biosafety of the biological adhesion reticulate structure, indicating a promising translational prospect for further clinical use.


Asunto(s)
Conjuntivitis Bacteriana , Nanopartículas , Ratas , Animales , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Antibacterianos/química , Sistemas de Liberación de Medicamentos , Conjuntivitis Bacteriana/tratamiento farmacológico , Nanopartículas/química , Resultado del Tratamiento
14.
PLoS One ; 18(3): e0282903, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36893193

RESUMEN

We applied a recently developed method, laser metrology, to characterize the influence of collector rotation on porosity gradients of electrospun polycaprolactone (PCL) widely investigated for use in tissue engineering. The prior- and post-sintering dimensions of PCL scaffolds were compared to derive quantitative, spatially-resolved porosity 'maps' from net shrinkage. Deposited on a rotating mandrel (200 RPM), the central region of deposition reaches the highest porosity, ~92%, surrounded by approximately symmetrical decreases to ~89% at the edges. At 1100 RPM, a uniform porosity of ~88-89% is observed. At 2000 RPM, the lowest porosity, ~87%, is found in the middle of the deposition, rebounding to ~89% at the edges. Using a statistical model of random fiber network, we demonstrated that these relatively small changes in porosity values produce disproportionately large variations in pore size. The model predicts an exponential dependence of pore size on porosity when the scaffold is highly porous (e.g., >80%) and, accordingly, the observed porosity variation is associated with dramatic changes in pore size and ability to accommodate cell infiltration. Within the thickest regions most likely to 'bottleneck' cell infiltration, pore size decreases from ~37 to 23 µm (38%) when rotational speeds increased from 200 to 2000 RPM. This trend is corroborated by electron microscopy. While faster rotational speeds ultimately overcome axial alignment induced by cylindrical electric fields associated with the collector geometry, it does so at the cost of eliminating larger pores favoring cell infiltration. This puts the bio-mechanical advantages associated with collector rotation-induced alignment at odds with biological goals. A more significant decrease in pore size from ~54 to ~19 µm (65%), well below the minimum associated with cellular infiltration, is observed from enhanced collector biases. Finally, similar predictions show that sacrificial fiber approaches are inefficient in achieving cell-permissive pore sizes.


Asunto(s)
Ingeniería de Tejidos , Andamios del Tejido , Porosidad , Poliésteres , Rayos Láser
15.
Front Microbiol ; 14: 1259935, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37822748

RESUMEN

Introduction: Actinobacillus pleuropneumoniae is an important respiratory pathogen, which can cause porcine contagious pleuropneumonia and lead to great economic losses to worldwide swine industry. High potassium is an adverse environment for bacteria, which is not conducive to providing turgor pressure for cell growth and division. Two-component system CpxAR is an important regulatory system of bacteria in response to environmental changes, which is involved in a variety of biological activities, such as antibiotic resistance, periplasmic protein folding, peptidoglycan metabolism and so on. Methods: However, little is known about the role of CpxAR in high potassium stress in A. pleuropneumoniae. Here, we showed that CpxAR is critical for cell division of A. pleuropneumoniae under high potassium (K+) stress. Results: qRT-PCR analysis found that CpxAR positively regulated the cell division genes ftsEX. In addition, we also demonstrated that CpxR-P could directly bind the promoter region of the cell division gene ftsE by EMSA. Discussion: In conclusion, our results described a mechanism where CpxAR adjusts A. pleuropneumoniae survival under high-K+ stress by upregulating the expression of the cell division proteins FtsE and FtsX. These findings are the first to directly demonstrate CpxAR-mediated high-K+ tolerance, and to investigate the detailed molecular mechanism.

16.
Int Immunopharmacol ; 121: 110559, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37364325

RESUMEN

BACKGROUND: Hypoxia plays a significant role in the pathogenesis of chronic rhinosinusitis (CRS). However, the role and mechanism of hypoxia in the type 2 immune response in eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP) remain unclear. METHODS: The expression of hypoxia-inducible factor-1α (HIF-1α) and epithelial-derived cytokines (EDCs), including interleukin (IL)-25, IL-33, and thymic stromal lymphopoietin (TSLP), was detected in nasal polyps via immunohistochemical analysis. The relationship between HIF-1α and EDCs was also elucidated using Pearson's correlation. Moreover, primary human nasal epithelial cells (HNECs) and a mouse model of ECRSwNP were employed to elucidate the role and mechanism of hypoxia in type 2 immune responses. RESULTS: HIF-1α, IL-25, IL-33, and TSLP expression levels were upregulated in the non-ECRSwNP and ECRSwNP groups compared with the control group, with the ECRSwNP group having the highest HIF-1α and EDC expression levels. Additionally, HIF-1α was positively correlated with IL-25 and IL-33 in the ECRSwNP group. Meanwhile, treatment with a HIF-1α inhibitor, PX-478, inhibited the hypoxia-induced increase in the mRNA and protein expression of EDCs and type 2 cytokines in HNECs. Similarly, in vivo, PX-478 inhibited EDC expression in the sinonasal mucosa of mice with ECRSwNP. CONCLUSIONS: Hypoxia induces EDC expression by upregulating HIF-1α levels, thereby promoting type 2 immune responses and the development of ECRSwNP. Hence, targeting HIF-1α may represent an effective therapeutic strategy for ECRSwNP.


Asunto(s)
Pólipos Nasales , Rinitis , Sinusitis , Humanos , Animales , Ratones , Citocinas/metabolismo , Interleucina-33 , Linfopoyetina del Estroma Tímico , Hipoxia , Enfermedad Crónica
17.
Front Neurol ; 13: 937054, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35937055

RESUMEN

The larval zebrafish acquires a repertoire of vestibular-driven behaviors that aid survival early in development. These behaviors rely mostly on the utricular otolith, which senses inertial (tilt and translational) head movements. We previously characterized the known central brainstem targets of utricular afferents using serial-section electron microscopy of a larval zebrafish brain. Here we describe the rest of the central targets of utricular afferents, focusing on the neurons whose identities are less certain in our dataset. We find that central neurons with commissural projections have a wide range of predicted directional tuning, just as in other vertebrates. In addition, somata of central neurons with inferred responses to contralateral tilt are located more laterally than those with inferred responses to ipsilateral tilt. Many dorsally located central utricular neurons are unipolar, with an ipsilateral dendritic ramification and commissurally projecting axon emerging from a shared process. Ventrally located central utricular neurons tended to receive otolith afferent synaptic input at a shorter distance from the soma than in dorsally located neurons. Finally, we observe an unexpected synaptic target of utricular afferents: afferents from the medial (horizontal) semicircular canal. Collectively, these data provide a better picture of the gravity-sensing circuit. Furthermore, we suggest that vestibular circuits important for survival behaviors develop first, followed by the circuits that refine these behaviors.

18.
Neural Netw ; 149: 124-136, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35228149

RESUMEN

As a special case of multi-classification, ordinal regression (also known as ordinal classification) is a popular method to tackle the multi-class problems with samples marked by a set of ranks. Semi-supervised ordinal regression (SSOR) is especially important for data mining applications because semi-supervised learning can make use of the unlabeled samples to train a high-quality learning model. However, the training of large-scale SSOR is still an open question due to its complicated formulations and non-convexity to the best of our knowledge. To address this challenging problem, in this paper, we propose an incremental learning algorithm for SSOR (IL-SSOR), which can directly update the solution of SSOR based on the KKT conditions. More critically, we analyze the finite convergence of IL-SSOR which guarantees that SSOR can converge to a local minimum based on the framework of concave-convex procedure. To the best of our knowledge, the proposed new algorithm is the first efficient on-line learning algorithm for SSOR with local minimum convergence guarantee. The experimental results show, IL-SSOR can achieve better generalization than other semi-supervised multi-class algorithms. Compared with other semi-supervised ordinal regression algorithms, our experimental results show that IL-SSOR can achieve similar generalization with less running time.


Asunto(s)
Algoritmos , Aprendizaje Automático Supervisado , Minería de Datos
19.
Environ Sci Pollut Res Int ; 29(44): 66659-66674, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35508855

RESUMEN

Ecological compensation policies for the watershed (ECPW) have played a guiding role in establishing a sound watershed ecological compensation system with Chinese characteristics, and the quantitative evaluation of current policies can provide a reference for policy optimization. Firstly, taking 77 ECPW promulgated in China from 2006 to 2020 as the research objects, this paper extracted keyword frequencies using a text mining method, and then selected the policy indicators by combining the policy characteristics and existing results of watershed ecological compensation. Secondly, the Fuzzy analytic hierarchy process was used to determine the weights of the variables and improve the Policy Modeling Consistency Index (PMC-Index). Finally, the empirical analysis was conducted on six typical policies and the differences among P1, P3, and P5 at the three levels of the national, provincial, and municipal levels were further explored and compared. It was found that (1) the consistency evaluation of P1, P2, P3, and P4 were excellent levels, and that of P5 and P6 were acceptable levels. (2) The mean value of an improved PMC-Index of the six strategies was 0.6287, which indicated that the overall performance of the quality of ECPW was good, but still room for improvement. (3) The quality of China's ECPW showed a trend that the higher the level of government, the better the overall performance of the policy. The more targeted the ECPW, the lower the PMC index score, which is manifested in indicators such as incentive measures, policy mechanisms, policy areas, and policy functions. This study helps to fully understand the strengths and weaknesses of China's single ECPW.


Asunto(s)
Ecosistema , Gobierno , China , Servicios de Salud , Políticas
20.
Front Neurol ; 13: 940419, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35968291

RESUMEN

Objective: Using rhythmic auditory stimulation (RAS) to improve gait disturbance in Parkinson's disease (PD) is an available treatment option, yet a consensus on its effectiveness remains controversial. We summarized the effects of RAS on gait, functional activity and quality of life in PD patients through a systematic review and meta-analysis. Methods: PubMed, Embase, Web of Science, Medline, and Cochrane Library databases were initially searched to identify relevant literature up to August 2021. Next, the methodological quality of eligible comparative studies was assessed by the Physiotherapy Evidence Database Scale. The treatment effects to clinical outcome in relation to gait, motor activities, and quality of life were analyzed. Results: A total of 18 studies consisted of 774 subjects were included in this meta-analysis. Comparing with the control group, RAS had significantly increased stride length (p < 0.001), accelerated gait speed (p < 0.001), reduced the occurrence of freezing events during walking (P = 0.009), achieved an improvement in Unified Parkinson's Disease Rating Scale (UPDRS) II (P = 0.030), UPDRS-III (P < 0.001) and Parkinson's Disease Quality of Life Questionnaire (PDQL) (p = 0.009) scores over an interval of 1-26 months. Conclusion: In this meta-analysis of 18 randomized controlled trials, we have demonstrated that RAS improves the general motor functions (UPDRS-III), particularly in gait, mobility and quality of life, in patients with Parkinson's disease.

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