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Therapeutic Advances in Respiratory... 2024The two patients included in the study had mixed and refractory post-tuberculosis tracheobronchial stenosis (PTTS), having experienced unsuccessful interventional... (Review)
Review
The two patients included in the study had mixed and refractory post-tuberculosis tracheobronchial stenosis (PTTS), having experienced unsuccessful interventional therapies such as balloon dilation and V-shaped stent placement before the operation. Following the secure placement of L-shaped silicone stents, examinations with a fiberbronchoscope during the first and third months post-operation revealed a significant reduction in bronchial mucosa inflammation for both patients. Additionally, the opening diameter of the upper and lower branch segments increased, and chest CT scans indicated a noticeable absorption of left pulmonary lesions. Three months post-operation, fiberbronchoscopy confirmed the stable fixation of the stent without any movement. The patients exhibited substantial improvements in pulmonary function, dyspnea index, and blood gas analysis, with no reported adverse complications. After 7 months, a follow-up fiberbronchoscope for one case revealed excellent stent fixation. Simultaneously, the chest CT scan indicated favorable re-expansion. The placement of L-shaped silicone stents proves effective in preventing displacement, alleviating airway stenosis or obstruction, and ensuring the safety and efficacy of PTTS treatment - particularly in cases where V-shaped silicone stent placement has failed. To our knowledge, this is the first study describing the L-shaped silicone stent in two patients with PTTS.
Topics: Humans; Stents; Silicones; Bronchial Diseases; Tracheal Stenosis; Bronchoscopy; Male; Constriction, Pathologic; Female; Treatment Outcome; Adult; Middle Aged; Prosthesis Design; Tuberculosis, Pulmonary; Tomography, X-Ray Computed
PubMed: 38785036
DOI: 10.1177/17534666241254901 -
Chemical Science May 2024The extensive utility of organosilicon compounds across a wide range of disciplines has sparked significant interest in their efficient synthesis. Although catalytic...
The extensive utility of organosilicon compounds across a wide range of disciplines has sparked significant interest in their efficient synthesis. Although catalytic 1,2-silyldifunctionalization of alkenes provides a promising method for the assembly of intricate organosilicon frameworks with atom and step economy, its advancement is hindered by the requirement of an external hydrogen atom transfer (HAT) agent in photoredox catalysis. Herein, we disclose an efficient three-component silylacylation of α,β-unsaturated carbonyl compounds, leveraging a synergistic nickel/photoredox catalysis with various hydrosilanes and aroyl chlorides. This method enables the direct conversion of acrylates into valuable building blocks that contain both carbonyl and silicon functionalities through a single, redox-neutral process. Key to this reaction is the precise activation of the Si-H bond, achieved through chlorine radical-induced HAT, enabled by the photoelimination of a Ni-Cl bond. Acyl chlorides serve a dual role, functioning as both acylating agents and chloride donors. Our methodology is distinguished by its mild conditions and extensive substrate adaptability, significantly enhancing the late-stage functionalization of pharmaceuticals.
PubMed: 38784747
DOI: 10.1039/d4sc02164a -
Communications Biology May 2024The question of whether material stiffness enhances cell adhesion and clustering is still open to debate. Results from the literature are seemingly contradictory, with...
The question of whether material stiffness enhances cell adhesion and clustering is still open to debate. Results from the literature are seemingly contradictory, with some reports illustrating that adhesion increases with surface stiffness and others suggesting that the performance of a system of cells is curbed by high values of elasticity. To address the role of elasticity as a regulator in neuronal cell adhesion and clustering, we investigated the topological characteristics of networks of neurons on polydimethylsiloxane (PDMS) surfaces - with values of elasticity (E) varying in the 0.55-2.65 MPa range. Results illustrate that, as elasticity increases, the number of neurons adhering on the surface decreases. Notably, the small-world coefficient - a topological measure of networks - also decreases. Numerical simulations and functional multi-calcium imaging experiments further indicated that the activity of neuronal cells on soft surfaces improves for decreasing E. Experimental findings are supported by a mathematical model, that explains adhesion and clustering of cells on soft materials as a function of few parameters - including the Young's modulus and roughness of the material. Overall, results indicate that - in the considered elasticity interval - increasing the compliance of a material improves adhesion, improves clustering, and enhances communication of neurons.
Topics: Cell Adhesion; Neurons; Animals; Elasticity; Dimethylpolysiloxanes; Surface Properties; Elastic Modulus; Cells, Cultured; Rats
PubMed: 38778159
DOI: 10.1038/s42003-024-06329-9 -
Chemical & Pharmaceutical Bulletin 2024Herein, we report the functionalization of polyhedral oligosilsesquioxanes (POSS) and related siloxanes with arynes. Using o-triazenylarylboronic acids as aryne...
Herein, we report the functionalization of polyhedral oligosilsesquioxanes (POSS) and related siloxanes with arynes. Using o-triazenylarylboronic acids as aryne precursors and silica gel as the activator, the transformation of siloxane bearing various arynophilic moieties on the side chains was achieved with high yields without touching the siloxane core. This method was applied to the conjugation of POSS and pharmaceutical cores using an aryne derived from the synthetic intermediate of cabozantinib. Furthermore, orthogonal dual functionalization of POSS was realized by combining the aryne reaction with Huisgen cyclization.
Topics: Alkynes; Boronic Acids; Cyclization; Molecular Structure; Organosilicon Compounds; Siloxanes; Triazines
PubMed: 38777760
DOI: 10.1248/cpb.c24-00192 -
Talanta Aug 2024Ultrasensitive and rapid detection of low concentration of Escherichia coli O157: H7 (E. coli O157:H7) in food is essential for food safety and public health. In this...
Fluorescent biosensor based on magnetic separation platform and spore-like breakable organosilica nanocapsules controlled-release carbon dots for the detection of Escherichia coli O157:H7.
Ultrasensitive and rapid detection of low concentration of Escherichia coli O157: H7 (E. coli O157:H7) in food is essential for food safety and public health. In this study, A novel fluorescence signal amplification biosensor based on magnetic separation platform and red fluorescent carbon dots (R-CDs)-encapsulated breakable organosilica nanocapsules (BONs) for ultrasensitive detection of E. coli O157:H7 was established. Wulff-type boronic acid functionalized magnetic nanoparticles (MNPs@B-N/APBA) with broad-spectrum bacterial recognition ability were synthesized for the first time to recognize and capture E. coli O157: H7 in food samples. R-CDs@BONs labeled with anti-E. coli O157:H7 monoclonal antibody (mAb@R-CDs@BONs-NH) were used as the second recognition element to ensure the specificity for E. coli O157:H7 and form MNPs@B-N/APBA∼ E. coli O157:H7∼mAb@R-CDs@BONs-NH sandwich complexes, followed by releasing R-CDs to generate amplified fluorescence response signals for quantitative detection of E. coli O157:H7. The proposed method had a limit of detection with 25 CFU/mL in pure culture and contaminated lettuce samples, which the whole detection process took about 120 min. This fluorescence signal amplification biosensor has the potential to detect other pathogens in food by altering specific antibodies.
Topics: Escherichia coli O157; Biosensing Techniques; Carbon; Quantum Dots; Nanocapsules; Fluorescent Dyes; Fluorescence; Limit of Detection; Organosilicon Compounds; Food Microbiology; Lactuca
PubMed: 38776775
DOI: 10.1016/j.talanta.2024.126273 -
Colloids and Surfaces. B, Biointerfaces Jul 2024Adoptive T cell therapy has undergone remarkable advancements in recent decades; nevertheless, the rapid and effective ex vivo expansion of tumor-reactive T cells...
Adoptive T cell therapy has undergone remarkable advancements in recent decades; nevertheless, the rapid and effective ex vivo expansion of tumor-reactive T cells remains a formidable challenge, limiting their clinical application. Artificial antigen-presenting substrates represent a promising avenue for enhancing the efficiency of adoptive immunotherapy and fostering T cell expansion. These substrates offer significant potential by providing flexibility and modularity in the design of tailored stimulatory environments. Polydimethylsiloxane (PDMS) silicone elastomer stands as a widely utilized biomaterial for exploring the varying sensitivity of T cell activation to substrate properties. This paper explores the optimization of PDMS surface modification and formulation to create customized stimulatory surfaces with the goal of enhancing T cell expansion. By employing soft PDMS elastomer functionalized through silanization and activating agent, coupled with site-directed protein immobilization techniques, a novel T cell stimulatory platform is introduced, facilitating T cell activation and proliferation. Notably, our findings underscore that softer modified elastomers (Young' modulus E∼300 kPa) exhibit superior efficacy in stimulating and activating mouse CD4 T cells compared to their stiffer counterparts (E∼3 MPa). Furthermore, softened modified PDMS substrates demonstrate enhanced capabilities in T cell expansion and Th1 differentiation, offering promising insights for the advancement of T cell-based immunotherapy.
Topics: Dimethylpolysiloxanes; Animals; Surface Properties; Lymphocyte Activation; Mice; Cell Proliferation; T-Lymphocytes; Mice, Inbred C57BL
PubMed: 38776594
DOI: 10.1016/j.colsurfb.2024.113977 -
Archives of Biochemistry and Biophysics Jul 2024Biomechanical signals in the extracellular niche are considered promising for programming the lineage specification of stem cells. Recent studies have reported that...
Biomechanical signals in the extracellular niche are considered promising for programming the lineage specification of stem cells. Recent studies have reported that biomechanics, such as the microstructure of nanomaterials, can induce adipose-derived stem cells (ASCs) to differentiate into osteoblasts, mediating gene regulation at the epigenetic level. Therefore, in this study, transcriptome expression levels of histone demethylases in ASCs were screened after treatment with different matrix stiffnesses, and histone lysine demethylase 3B (KDM3B) was found to promote osteogenic differentiation of ASCs in response to matrix stiffness, indicating a positive modulatory effect on this biological process. ASCs exhibited widespread and polygonal shapes with a distinct bundle-like expression of vinculin parallel to the axial cytoskeleton along the cell margins on the stiff matrix rather than round shapes with a smeared and shorter expression on the soft matrix. Comparatively rigid polydimethylsiloxane material directed ASCs into an osteogenic phenotype in inductive culture media via the upregulation of osteocalcin, alkaline phosphatase, and runt-related transcription factor 2. Treatment with KDM3B-siRNA decreased the expression of osteogenic differentiation markers and impaired mitochondrial dynamics and mitochondrial membrane potential. These results illustrate the critical role of KDM3B in the biomechanics-induced osteogenic commitment of ASCs and provide new avenues for the further application of stem cells as potential therapeutics for bone regeneration.
Topics: Osteogenesis; Humans; Cell Differentiation; Jumonji Domain-Containing Histone Demethylases; Adipose Tissue; Stem Cells; Cells, Cultured; Extracellular Matrix; Dimethylpolysiloxanes
PubMed: 38768746
DOI: 10.1016/j.abb.2024.110028 -
BMC Oral Health May 2024Vinyl polyether silicone (VPES) is a novel impression biomaterial made of a combination of vinyl polysiloxane (VPS) and polyether (PE). Thus, it is significant to assess...
BACKGROUND
Vinyl polyether silicone (VPES) is a novel impression biomaterial made of a combination of vinyl polysiloxane (VPS) and polyether (PE). Thus, it is significant to assess its properties and behaviour under varied disinfectant test conditions. This study aimed to assess the dimensional stability of novel VPES impression material after immersion in standard disinfectants for different time intervals.
METHODS
Elastomeric impression material used -medium body regular set (Monophase) [Exa'lence GC America]. A total of 84 Specimens were fabricated using stainless steel die and ring (ADA specification 19). These samples were distributed into a control group (n=12) and a test group (n=72). The test group was divided into 3 groups, based on the type of disinfectant used - Group-A- 2% Glutaraldehyde, Group-B- 0. 5% Sodium hypochlorite and Group-C- 2% Chlorhexidine each test group was further divided into 2 subgroups (n=12/subgroup) based on time intervals for which each sample was immersed in the disinfectants - subgroup-1- 10 mins and Subgroup 2- 30 mins. After the impression material was set, it was removed from the ring and then it was washed in water for 15 seconds. Control group measurements were made immediately on a stereomicroscope and other samples were immersed in the three disinfection solutions for 10 mins and 30 mins to check the dimensional stability by measuring the distance between the lines generated by the stainless steel die on the samples using a stereomicroscope at x40 magnification.
RESULTS
The distance measured in the control group was 4397.2078 µm and 4396.1571 µm; for the test group Group-A- 2% Glutaraldehyde was 4396.4075 µm and 4394.5992 µm; Group-B- 0. 5% Sodium hypochlorite was 4394.5453 µm and 4389.4711 µm Group-C- 2% Chlorhexidine was 4395.2953 µm and 4387.1703 µm respectively for 10 mins and 30 mins. Percentage dimensional change was in the range of 0.02 - 0.25 for all the groups for 10 mins and 30 mins.
CONCLUSIONS
2 % Glutaraldehyde is the most suitable disinfectant for VPES elastomeric impression material in terms of dimensional stability and shows minimum dimensional changes as compared to that of 2% Chlorhexidine and 0.5% Sodium hypochlorite.
Topics: Dental Impression Materials; Polyvinyls; Siloxanes; Materials Testing; Time Factors; Glutaral; Dental Disinfectants; Sodium Hypochlorite; Disinfectants; Chlorhexidine; Surface Properties; Humans
PubMed: 38762747
DOI: 10.1186/s12903-024-04323-5 -
Journal of Chromatography. A Jul 2024Continuous C8 stationary phase gradients are created on commercial Waters Symmetry Shield RP8 columns by strategically cleaving the C8 moieties in a time-dependent...
Continuous C8 stationary phase gradients are created on commercial Waters Symmetry Shield RP8 columns by strategically cleaving the C8 moieties in a time-dependent fashion. The method relies on the controlled infusion of a trifluoroacetic acid/water/acetonitrile solution through the column to cleave the organic functionality (e.g., C8) from the siloxane framework. The bond cleavage solution is reactive enough to cleave the functional groups, even with polar groups embedded within the stationary phase to protect the silica. Both the longitudinal and radial heterogeneity were evaluated by extruding the silica powder into polyethylene tubing and evaluating the percent carbon content in the different sections using thermogravimetric analysis (TGA). TGA analysis shows the presence of a stationary phase gradient in the longitudinal direction but not in the radial direction. Two different gradient profiles were formed with good reproducibility by modifying the infusion method: one exhibited an 'S'-shaped gradient while the other exhibited a steep exponential-like gradient. The gradients were characterized chromatographically using test mixtures, and the results showed varied retention characteristics and an enhanced ability to resolve nicotine analytes.
Topics: Silicon Dioxide; Acetonitriles; Nicotine; Chromatography, Liquid; Trifluoroacetic Acid; Thermogravimetry; Reproducibility of Results; Siloxanes; Water; Chromatography, High Pressure Liquid
PubMed: 38761702
DOI: 10.1016/j.chroma.2024.464974 -
The Journal of Organic Chemistry Jun 2024An organocatalyzed photoelectrochemical method for the generation of acyl and phosphoryl radicals from formamides, aldehydes, and phosphine oxides has been developed....
An organocatalyzed photoelectrochemical method for the generation of acyl and phosphoryl radicals from formamides, aldehydes, and phosphine oxides has been developed. This protocol utilizes 9,10-phenanthrenequinone (PQ) as both a molecular catalyst and a hydrogen atom-transfer (HAT) reagent, eliminating the requirement for external metal-based reagents, HAT reagents, and oxidants. The generated acyl radicals can be applied to a range of radical-mediated transformation reactions, including C-H carbamoylation of heteroarenes, intermolecular tandem radical cyclization of CF-substituted -arylacrylamides, as well as intramolecular cyclization reactions. The use of acyl radicals in these transformations offers an efficient and sustainable approach to accessing structurally diverse carbonyl compounds.
PubMed: 38761155
DOI: 10.1021/acs.joc.4c00189