RESUMEN
This paper studies an optimal synchronous control protocol design for nonlinear multi-agent systems under partially known dynamics and uncertain external disturbance. Under some mild assumptions, Hamilton-Jacobi-Isaacs equation is derived by the performance index function and system dynamics, which serves as an equivalent formulation. Distributed policy iteration adaptive dynamic programming is developed to obtain the numerical solution to the Hamilton-Jacobi-Isaacs equation. Three theoretical results are given about the proposed algorithm. First, the iterative variables is proved to converge to the solution to Hamilton-Jacobi-Isaacs equation. Second, the L2-gain performance of the closed loop system is achieved. As a special case, the origin of the nominal system is asymptotically stable. Third, the obtained control protocol constitutes an Nash equilibrium solution. Neural network-based implementation is designed following the main results. Finally, two numerical examples are provided to verify the effectiveness of the proposed method.
RESUMEN
Hierarchically porous monoliths with satisfactory properties have been employed in diverse fields, especially separation. In this study, pentafluorophenyl acrylate (PFPA), pentaerythritol tetraacrylate (PETA) and trimethylolpropane tris(3-mercaptopropionate) (TTMP) were selected as precursors to fabricate a novel monolithic column by thermally initiated polymerization in the presence of a binary porogenic system containing tetrahydrofuran and 1-propanol. The fabricated poly(PFPA-co-PETA-co-TTMP) monolithic column revealed excellent permeability and mechanical stability. Additionally, baseline separation of the mixture of small molecules can be achieved, involving alkylbenzene and fluorobenzene in chromatographic assessment, and the theoretical plate number is up to 60,500 plates/m for butylbenzene with a linear velocity of 0.14 mm/s. Tryptic digest of HeLa as an analyte was used to investigate the possibility of the poly(PFPA-co-PETA-co-TTMP) monolith in biological separation by cLC-MS/MS. Moreover, benefiting from the existence of pentafluorophenyl groups, the cucurbit[8]uril (CB[8]) could be modified on the prepared poly(PFPA-co-PETA-co-TTMP) monolith through host-guest interaction to obtain poly(PFPA-co-PETA-co-TTMP)-CB[8] monolith. It could be observed that significant changes in retention behavior of analytes appeared after immobilizing CB[8] on the monolith. It offered an innovative approach by utilizing host-guest interaction to fabricate monolithic columns with different chromatographic behaviors.
Asunto(s)
Acrilatos , Humanos , Cromatografía Liquida/métodos , Porosidad , Acrilatos/química , Células HeLa , Propiedades de Superficie , Espectrometría de Masas en Tándem/métodos , Polimerizacion , Polímeros/química , Glicoles de PropilenoRESUMEN
We aim to observe the posterior scleral reinforcement (PSR) clinical outcomes of children with high myopia and analyze the retinal vessel alteration before and after PSR by using angiography optical coherence tomography (angio-OCT). Fifty-six pediatric participants (112 eyes) clinically diagnosed high myopia were recruited and were treated by PSR in Shanghai Children's Hospital from June 1, 2021 to May 1, 2023. The average age ranged from 5.42 to 14.83 years (mean 8.83 years) and mean follow up duration was 8.7 months (3-24 months). The axial length (AL) was significantly shortened after PSR (p < 0.05). The spherical equivalent (SE) and the best-corrected visual acuity (BCVA) were also improved without severe rejection in the follow-up. Compared with baseline, angio-OCT parafoveal vessel indices including vascular area density (VAD) and vascular skeleton density (VSD) on the superficial capillary plexus layer (SCPL), as well as VAD and vessel perimeter index (VPI) on the deep capillary plexus layer (DCPL), were significantly increased after PSR surgery (p < 0.05). VPI on the SCPL, vascular diameter index (VDI) and VSD on the DCPL were also improved without statistical difference after PSR. The VSD on SCPL, VAD on DCPL of the right eyes and the VPI on SCPL of the left eyes were significantly increased after PSR (p < 0.05). PSR surgery can shorten the AL and can stable BCVA and SE in high myopia children. The angio-OCT parameters indicated that the retinal microcirculation supply was significantly improved after PSR.
Asunto(s)
Esclerótica , Tomografía de Coherencia Óptica , Humanos , Niño , Masculino , Femenino , Adolescente , Tomografía de Coherencia Óptica/métodos , Esclerótica/cirugía , Resultado del Tratamiento , Preescolar , Agudeza Visual , Miopía/cirugía , Vasos Retinianos/diagnóstico por imagen , Vasos Retinianos/patología , China , Miopía Degenerativa , Pueblos del Este de AsiaRESUMEN
X-ray dual-phase grating interferometry provides quantitative micro-structural information beyond the optical resolution through its tunable correlation length. Ensuring optimal performance of the set-up requires accurate correlation length estimation and precise alignment of the gratings. This paper presents an automated procedure for determining the complete geometrical parameters of the interferometer set-up with a high degree of precision. The algorithm's effectiveness is then evaluated through a series of experimental tests, illustrating its accuracy and robustness.
RESUMEN
The current research models of breast cancer are usually limited in their capacity to recapitulate the tumor microenvironment in vitro. The lack of an extracellular matrix (ECM) oversimplifies cell-cell or cell-ECM cross-talks. Moreover, the lack of tumor-associated macrophages (TAMs), that can comprise up to 50% of some solid neoplasms, poses a major problem for recognizing various hallmarks of cancer. To address these concerns, a type of direct breast cancer cells (BCCs)-TAMs coculture organoid model was well developed by a sequential culture method in this study. Alginate cryogels were fabricated with appropriate physical and mechanical properties to serve as an alternative ECM. Then, our previous experience was leveraged to polarize TAMs inside of the cryogels for creating an in vitro immune microenvironment. The direct coculture significantly enhanced BCCs organoid growth and cancer aggressive phenotypes, including the stemness, migration, ECM remodeling, and cytokine secretion. Furthermore, transcriptomic analysis and protein-protein interaction networks implied certain pathways (PI3K-Akt pathway, MAPK signaling pathway, etc.) and targets (TNF, PPARG, TLR2, etc.) during breast cancer progression in a TAM-leading immune microenvironment. Future studies to advance treatment strategies for BCC patients may benefit from using this facile model to reveal and target the interactions between cancer signaling and the immune microenvironment.
Asunto(s)
Neoplasias de la Mama , Humanos , Femenino , Neoplasias de la Mama/patología , Macrófagos Asociados a Tumores/metabolismo , Técnicas de Cocultivo , Biomimética , Criogeles/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Macrófagos/metabolismo , Microambiente Tumoral , Línea Celular TumoralRESUMEN
The multi-scale characterization of building materials is necessary to understand complex mechanical processes, with the goal of developing new more sustainable materials. To that end, imaging methods are often used in materials science to characterize the microscale. However, these methods compromise the volume of interest to achieve a higher resolution. Dark-field (DF) contrast imaging is being investigated to characterize building materials in length scales smaller than the resolution of the imaging system, allowing a direct comparison of features in the nano-scale range and overcoming the scale limitations of the established characterization methods. This work extends the implementation of a dual-phase X-ray grating interferometer (DP-XGI) for DF imaging in a lab-based setup. The interferometer was developed to operate at two different design energies of 22.0 keV and 40.8 keV and was designed to characterize nanoscale-size features in millimeter-sized material samples. The good performance of the interferometer in the low energy range (LER) is demonstrated by the DF retrieval of natural wood samples. In addition, a high energy range (HER) configuration is proposed, resulting in higher mean visibility and good sensitivity over a wider range of correlation lengths in the nanoscale range. Its potential for the characterization of mineral building materials is illustrated by the DF imaging of a Ketton limestone. Additionally, the capability of the DP-XGI to differentiate features in the nanoscale range is proven with the dark-field of Silica nanoparticles at different correlation lengths of calibrated sizes of 106 nm, 261 nm, and 507 nm.
RESUMEN
High-performance reusable materials from renewable resources are rare and urgently required in bioseparation. Herein, a series of tannic acid-chitosan composite membranes for the enrichment of phosphopeptides were fabricated by the freeze casting method. First, a tannic acid-chitosan composite membrane was acquired via the multiple hydrogen bonds between tannic acid and chitosan, which had a long-range aligned three-dimensional microstructure. Second, a covalent-hydrogen bond hybrid composite was also fabricated, with stable and aligned honeycomb-like microstructures that formed by the synergy of covalence and hydrogen bonding. Besides, a ternary composite membrane was "one-pot" synthesized by the copolymerization of tannic acid, chitosan, and Ti4+ ions, indicating the feasibility of involving metal ions in the composition of the polymer skeleton in place of additional modification steps. The as-prepared chitosan composite membranes exhibited excellent performance in the enrichment of phosphopeptides from ß-casein tryptic digest and human serum. Benefitting from the long-range aligned honeycomb-like structure coordinated by hydrogen bonds and covalent bonds, and a large number of pyrogallol functional groups provided by tannic acid, the covalent-hydrogen bond hybrid membrane showed excellent reusability and could be reused up to 16 times in phosphopeptide enrichment, as far as we know, which is the best reported result to date.
Asunto(s)
Quitosano , Fosfopéptidos , Humanos , Fosfopéptidos/química , Quitosano/química , Titanio/química , IonesRESUMEN
The dark-field signal provided by X-ray grating interferometry is an invaluable tool for providing structural information beyond the direct spatial resolution and their variations on a macroscopic scale. However, when using a polychromatic source, the beam-hardening effect in the dark-field signal makes the quantitative sub-resolution structural information inaccessible. Especially, the beam-hardening effect in dual-phase grating interferometry varies with spatial location, inter-grating distance, and diffraction order. In this work, we propose a beam-hardening correction algorithm, taking into account all these factors. The accuracy and robustness of the algorithm are then validated by experimental results. This work contributes a necessary step toward accessing small-angle scattering structural information in dual-phase grating interferometry.
RESUMEN
Establishing a long-term ex vivo observation of the intestinal stem cell (ISC) is crucial to help understand the formation and homeostasis of the intestinal epithelium. Here, we present a protocol for tracking the division of Drosophila pupal ISCs during pupal midgut development. We describe steps for dissecting, mounting, and live imaging the pupal midgut. We then detail procedures for fluorescence quantification of each cell. This protocol can be applied to other fluorescently tagged proteins. For complete details on the use and execution of this protocol, please refer to Wu et al.1.
Asunto(s)
Drosophila melanogaster , Intestinos , Animales , Pupa , Mucosa Intestinal , Drosophila , División CelularRESUMEN
RATIONALE: Staphylococcus argenteus (S argenteus) is a novel and emerging species that is part of the Staphylococcus aureus (S aureus) complex. Fatal cases of bloodstream infection caused by S argenteus are rarely reported and should be considered in medical practice. PATIENT CONCERNS: A 44-year-old male was admitted to our hospital with reduced appetite, high fever and unconsciousness. Laboratory tests indicated infection, muscle damage, and alkalosis in the patient. Brain computed tomography (CT) demonstrated small hematoma in left frontal lobe with peripheral cerebral edema. Chest CT demonstrating chronic bronchitis, emphysema, and bullae in the right lung. Blood culture was collected on the first day of hospitalization for microbial culture and pathological examination. DIAGNOSIS: The isolate from blood culture was identified as S argenteus by MALDI-TOF MS after the patient death. INTERVENTIONS: The patient was subjected to empirical antibiotic treatment with piperacillin/tazobactam. OUTCOMES: After 48 hours of hospitalization, the patient died after ineffective rescue. LESSONS: The patient had long-term heavy drinking and smoking as well as chronic malnutrition, which may account for his immune deficiency. The immunocompromised people are more vulnerable to infection by S argenteus and then develop bacteremia. The use of piperacillin/tazobactam may have contributed to the patient death.
Asunto(s)
Bacteriemia , Infecciones Estafilocócicas , Masculino , Humanos , Adulto , Staphylococcus , Infecciones Estafilocócicas/diagnóstico , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus aureus , Bacteriemia/tratamiento farmacológico , Antibacterianos/uso terapéutico , Combinación Piperacilina y TazobactamRESUMEN
Hip replacement femoral implants are made of substantial materials that all have stiffness considerably higher than that of bone, which can cause significant bone resorption secondary to stress shielding and lead to severe complications. The topology optimization design method based on the uniform distribution of material micro-structure density can form a continuous mechanical transmission route, which can better solve the problem of reducing the stress shielding effect. A multi-scale parallel topology optimization method is proposed in this paper and a topological structure of type B femoral stem is derived. Using the traditional topology optimization method (Solid Isotropic Material with Penalization, SIMP), a topological structure of type A femoral stem is also derived. The sensitivity of the two kinds of femoral stems to the change of load direction is compared with the variation amplitude of the structural flexibility of the femoral stem. Furthermore, the finite element method is used to analyze the stress of type A and type B femoral stem under multiple conditions. Simulation and experimental results show that the average stress of type A and type B femoral stem on the femur are 14.80 MPa, 23.55 MPa, 16.94 MPa and 10.89 MPa, 20.92 MPa, 16.50 MPa, respectively. For type B femoral stem, the average error of strain is -1682µÎµ and the average relative error is 20.3% at the test points on the medial side and the mean error of strain is 1281µÎµ and the mean relative error is 19.5% at the test points on the outside.
RESUMEN
Clinical evidence supports a role for the extracellular matrix (ECM) in cancer plasticity across multiple tumor types. The lack of in vitro models that represent the native ECMs is a significant challenge for cancer research and drug discovery. Therefore, a major motivation for developing new tumor models is to create the artificial ECM in vitro. Engineered biomaterials can closely mimic the architectural and mechanical properties of ECM to investigate their specific effects on cancer progression, offering an alternative to animal models for the testing of cancer cell behaviors. In this review, we focused on the biomaterials from different sources applied in the fabrication of the artificial ECM and their biophysical cues to recapitulate key features of tumor niche. Furthermore, we summarized how the distinct biophysical cues guided cell behaviors of cancer plasticity, including morphology, epithelial-to-mesenchymal transition (EMT), enrichment of cancer stem cells (CSCs), proliferation, migration/invasion and drug resistance. We also discuss the future opportunities in using the artificial ECM for applications of tumorigenesis research and precision medicine, as well as provide useful messages of principles for designing suitable biomaterial scaffolds.
RESUMEN
Apical-basal polarity and cell-fate determinants are crucial for the cell fate and control of stem cell numbers. However, their interplay leading to a precise stem cell number remains unclear. Drosophila pupal intestinal stem cells (pISCs) asymmetrically divide, generating one apical ISC progenitor and one basal Prospero (Pros)+ enteroendocrine mother cell (EMC), followed by symmetric divisions of each daughter before adulthood, providing an ideal system to investigate the outcomes of polarity loss. Using lineage tracing and ex vivo live imaging, we identify an interlocked polarity regulation network precisely determining ISC number: Bazooka inhibits Pros accumulation by activating Notch signaling to maintain stem cell fate in pISC apical daughters. A threshold of Pros promotes differentiation to EMCs and avoids ISC-like cell fate, and over-threshold of Pros inhibits miranda expression to ensure symmetric divisions in pISC basal daughters. Our work suggests that a polarity-dependent threshold of a differentiation factor precisely controls stem cell number.
Asunto(s)
Proteínas de Drosophila , Drosophila melanogaster , Animales , Recuento de Células , Diferenciación Celular , Polaridad Celular , Drosophila/metabolismo , Drosophila melanogaster/citología , Drosophila melanogaster/metabolismo , Proteínas de Drosophila/metabolismo , IntestinosRESUMEN
In this work, we analyze the interference patterns measured in lab-based dual-phase grating interferometry and for the first time explain the spatial dependencies of the measured interference patterns and the large visibility deviations between the theoretical prediction and the experimental results. To achieve this, a simulator based on wave propagation is developed. This work proves that the experimental results can be simulated with high accuracy by including the effective grating thickness profile induced by the cone-beam geometry, the measured detector response function and a non-ideal grating shape. With the comprehensive understanding of dual-phase grating interferometry, this provides the foundations for a more efficient and accurate algorithm to retrieve sample's structure information, and the realistic simulator is a useful tool for optimizing the set-up.
RESUMEN
A hydrophilic adsorbent (Cys@poly(AMA)@MAR) was successfully prepared for the enrichment of N-glycopeptides via surface-initiated atom transfer radical polymerization (SI-ATRP) and photo-initiated "thiol-ene" reaction using monodisperse macroporous adsorbent resin (MAR) as adsorption matrix. Due to the presence of electron-deficient acrylic groups and electron-rich vinyl groups in allyl methacrylate (AMA), both of them can participate in free radical reaction. Therefore, the polymerization time of SI-ATRP was optimized. The resulting poly(AMA)@MAR was modified with l-cysteine (L-Cys) via photo-initiated "thiol-ene" reaction, and the amount of vinyl retained was determined by measuring the adsorption of Cu2+. The Cys@poly(AMA)@MAR pendant brushes with high density of amine and carboxyl groups could capture N-glycopeptides from IgG digest and human serum digest by hydrophilic interaction. The 22 N-glycopeptides were identified from IgG digest and the limit of detection reached 10 fmol. The 319 N-glycosylation sites and 583 N-glycopeptides were identified from 2 µL human serum digest and mapped to 147 glycoproteins. It demonstrates great potential and commercialization prospects for the enrichment of N-glycopeptides.
Asunto(s)
Glicopéptidos , Compuestos de Sulfhidrilo , Humanos , Polimerizacion , Química Clic/métodos , Adsorción , Cisteína , Inmunoglobulina G , Interacciones Hidrofóbicas e HidrofílicasRESUMEN
Covalent triazine frameworks (CTFs) and their derivative N-doped carbons have attracted much attention for application in energy conversion and storage. However, previous studies have mainly focused on developing new building blocks and optimizing synthetic conditions. The use of isometric building blocks to control the porous structure and to fundamentally understand structure-property relationships have rarely been reported. In this work, two isometric building blocks are used to produce isometric CTFs with controllable pore geometries. The as-prepared CTF with nonplanar hexagonal rings demonstrates higher surface area, larger pore volume, and richer N content than the planar CTF. After pyrolysis, nonplanar porous CTF-derived N-doped carbons exhibit admirable catalytic activity for oxygen reduction in alkaline media (half-wave potential: 0.86â V; Tafel slope: 65â mV dec-1 ), owing to their larger pore volume and the abundance of pyridinic and graphitic N species. When assembled into a zinc-air battery, the as-made electrocatalysts show high capacities of up to 651â mAh g-1 and excellent durability.
RESUMEN
Primary cilia (PC) are important signaling hubs, and we here explored their role in colonic pathology. In the colon, PC are mostly present on fibroblasts, and exposure of mice to either chemically induced colitis-associated colon carcinogenesis (CAC) or dextran sodium sulfate (DSS)-induced acute colitis decreases PC numbers. We generated conditional knockout mice with reduced numbers of PC on colonic fibroblasts. These mice show increased susceptibility to CAC, as well as DSS-induced colitis. Secretome and immunohistochemical analyses of DSS-treated mice display an elevated production of the proinflammatory cytokine IL-6 in PC-deficient colons. An inflammatory environment diminishes PC presence in primary fibroblast cultures, which is triggered by IL-6 as identified by RNA-seq analysis together with blocking experiments. These findings suggest an activation loop between IL-6 production and PC loss. An analysis of PC presence on biopsies of patients with ulcerative colitis or colorectal cancer (CRC) reveals decreased numbers of PC on colonic fibroblasts in pathological compared with surrounding normal tissue. Taken together, we provide evidence that a decrease in colonic PC numbers promotes colitis and CRC.
Asunto(s)
Cilios , Interleucina-6 , Ratones , Animales , Interleucina-6/genéticaRESUMEN
Enrichment of phosphopeptides before mass spectrometry (MS) analysis is essential due to the limitations of low abundance and poor ionization efficiency in complex biological samples. Immobilized metal affinity chromatography (IMAC), especially titanium ion (Ti4+)-IMAC, has become a popular strategy for enrichment of phosphopeptides due to high selectivity and sensitivity. Conventional Ti4+-immobilized macroporous adsorption resin (MAR) fabricated by monolayer modification can preferentially capture mono-phosphopeptide over multi-phosphopeptides, which takes on more functions in the regulation of cell behaviors of organism. In this paper, a kind of monodisperse MAR microsphere with functional polymer brush (Ti4+-Brush@MAR) was prepared and modified via surface-initiated atom transfer radical polymerization (SI-ATRP). Compared with common Ti4+-MAR without polymer brush, Ti4+-Brush@MAR exhibited high enrichment specificity not only for mono-phosphopeptides but also for multi-phosphopeptides in ß-casein or milk digest samples. As a result, a total of 93 unique phosphopeptides mapped to 18 phosphoproteins were identified from 5 µL milk, and the limit of detection is 10 fmol. It is expected that Ti4+-Brush@MAR would be utilized to enrich both multi-phosphopeptides and mono-phosphopeptides in additional biological or food samples.
Asunto(s)
Leche , Titanio , Animales , Caseínas/química , Cromatografía de Afinidad/métodos , Leche/química , Fosfopéptidos/análisis , Polímeros , Titanio/químicaRESUMEN
Pannonibacter phragmitetus (P. phragmitetus) is rarely related with human disease. We reported a case of catheter-related infection caused by P. phragmitetus in a 68-year-old woman on hemodialysis. The patient developed recurrent fever during hemodialysis and blood cultures were positive for P. phragmitetus. The patient's body temperature returned to normal after intravenous cefoperazone/sulbactam treatment, and the hemodialysis catheter was locked with gentamicin and urokinase. The potential anti-infective treatment against P. phragmitetus was discussed.
Asunto(s)
Infecciones Relacionadas con Catéteres , Rhodobacteraceae , Anciano , Infecciones Relacionadas con Catéteres/diagnóstico , China , Humanos , Diálisis Renal/efectos adversosRESUMEN
Streptococcus sinensis was originally described as a causative agent for infective endocarditis in three Chinese patients from Hong Kong in 2002. Subsequently, several cases were reported outside Hong Kong, indicating that it is an emerging pathogen worldwide. We isolated a closely related strain in a young patient diagnosed with infective endocarditis in mainland China. In this paper, we reviewed the course of infection and provided a comprehensive comparison of its clinical characteristics with the reported cases.