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The dispersion stability of nano-lubricating additives is crucial for the shelf life of lubricant and its practical applications. Nitrogen-sulfur co-doped carbon dots (N,S@CDs) via a one-step hydrothermal method with nitropyrene and thiourea as raw materials are hereby presented. The N and S elements are selectively distributed throughout the entire carbon skeleton with a doping amount of 22.6 at%. The as-synthesized N,S@CDs exhibit excellent dispersion stability in PEG200 and maintain stability for over one year. The experiment results indicate that N,S@CDs significantly improve the anti-wear and friction reduction properties of PEG200, while the friction coefficient is reduced from 0.25 to 0.09 with 1.5 wt% N,S@CDs addition, and the wear volume, depth, and width are reduced by 68%, 52%, and 57%, respectively. The good lubrication performance is attributed to N,S@CDs excellent dispersion stability, enhanced filling and polishing effects, and complex tribochemical reactions caused by heteroatom doping to form a stable protective film on the worn surface. Furthermore, the as-prepared N,S@CDs exhibit intrinsic fluorescence intensity in PEG200 with the photoluminescence quantum yield (PLQY) of 12.5% and remain fluorescent stable during the long-term friction process, therefore the N,S@CDs have a potential application prospect in non-destructive detection of oil leakage via fluorescence labeling method.
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Traditional laser-assisted method (top-down synthesis strategy) is applied in the preparation of carbon dots (CDs) by cutting larger carbon materials, which requires harsh conditions, and the size distribution of the CDs is seldom monodisperse. In this work, heteroatom-doped CDs, represented by N,S co-doped CDs (N,S-CDs), can be prepared successfully by pulsed laser irradiation of heterocyclic aromatic hydrocarbons-based small molecule compound solution. The friction coefficient (COF) of base oil PAO decreases from 0.650 to 0.093, and the wear volume reduces by 92.0% accompanied by 1 wt.% N,S-CDs addition, while the load-bearing capacity is improved from 100 to 950 N. The excellent lubrication performance is mainly attributed to the formation of a robust tribofilm via a tribochemical reaction between N,S-CDs and friction pairs, and the N,S-CDs can play a mending effect and polishing effect for worn surfaces. Furthermore, the lubricant containing heteroatom doped CDs are capable of being prepared in situ via pulsed laser irradiation of heterocyclic aromatic hydrocarbons in base oil, which can avoid the redispersed problem of nano-additive in base oil to maintain long-term dispersion, with COF of 0.103 and low wear volume ≈1.99 × 105 µm3 (76.9% reduction) even after standing for 9 months.
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Lithium (Li) metal batteries are deemed as promising next-generation power solutions but are hindered by the uncontrolled dendrite growth and infinite volume change of Li anodes. The extensively studied 3D scaffolds as solutions generally lead to undesired "top-growth" of Li due to their high electrical conductivity and the lack of ion-transporting pathways. Here, by reducing electrical conductivity and increasing the ionic conductivity of the scaffold, the deposition spot of Li to the bottom of the scaffold can be regulated, thus resulting in a safe bottom-up plating mode of the Li and dendrite-free Li deposition. The resulting symmetrical cells with these scaffolds, despite with a limited pre-plated Li capacity of 5 mAh cm-2, exhibit ultra-stable Li plating/stripping for over 1 year (11 000 h) at a high current density of 3 mA cm-2 and a high areal capacity of 3 mAh cm-2. Moreover, the full cells with these scaffolds further demonstrate high cycling stability under challenging conditions, including high cathode loading of 21.6 mg cm-2, low negative-to-positive ratio of 1.6, and limited electrolyte-to-capacity ratio of 4.2 g Ah-1.
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The importance of the immune microenvironment in poorly cohesive carcinoma (PCC) has been highlighted due to its limited response rate to conventional therapy and emerging treatment resistance. A combination of clinical cohorts, bioinformatics analyses, and functional/molecular experiments revealed that high infiltration of Interferon Induced Protein with Tetratricopeptide Repeats 1 (IFIT1) + tumor-associated neutrophils (TANs) is a distinguishing feature of PCC patients. Upregulation of IFIT1 + TANs promote migration and invasion of gastric cancer (GC) cell lines (MKN45 and MKN74) and stimulates the growth of cell-derived xenograft models. Besides, by promoting macrophage secreted phosphoprotein 1 (SPP1) expression and facilitating cancer-associated fibroblast and endothelial cell recruitment and activation through TANs, IFIT1 promotes a mesenchymal phenotype, which is associated with a poor prognosis. Importantly, compared to non-PCC (NPCC), PCC tumors is more immunosuppressive. Mechanistically, IFIT1 can be stimulated by IFN-γ and contributes to the expression of Programmed Cell Death 1 Ligand (PDL1) in TANs. We demonstrated in mouse models that IFIT1 + PDL1 + TANs can induce acquired resistance to anti-PD-1 immunotherapy, which may be responsible for the difficulty of PCC patients to benefit from immunotherapy. This work highlights the role of IFIT1 + TANs in mediating the remodeling of the tumor immune microenvironment and immunotherapeutic resistance and introduces IFIT1 + TANs as a promising target for precision therapy of PCC.
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Proteínas Adaptadoras de Transdução de Sinal , Neutrófilos , Proteínas de Ligação a RNA , Humanos , Neutrófilos/imunologia , Neutrófilos/metabolismo , Animais , Proteínas de Ligação a RNA/metabolismo , Linhagem Celular Tumoral , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Microambiente Tumoral/imunologia , Feminino , Antígeno B7-H1/metabolismo , Neoplasias Gástricas/patologia , Neoplasias Gástricas/imunologia , Masculino , Camundongos , Resistencia a Medicamentos Antineoplásicos , Movimento Celular , Tolerância Imunológica , Terapia de Imunossupressão , Regulação Neoplásica da Expressão Gênica , Invasividade Neoplásica , Camundongos Nus , Imunoterapia , Pessoa de Meia-IdadeRESUMO
Cellular communication (CC) influences tumor development by mediating intercellular junctions between cells. However, the role and underlying mechanisms of CC in malignant transformation remain unknown. Here, we investigated the spatiotemporal heterogeneity of CC molecular expression during malignant transformation. It was found that although both tight junctions (TJs) and gap junctions (GJs) were involved in maintaining the tumor microenvironment (TME), they exhibited opposite characteristics. Mechanistically, for epithelial cells (parenchymal component), the expression of TJ molecules consistently decreased during normal-cancer transformation and is a potential oncogenic factor. For fibroblasts (mesenchymal component), the expression of GJs consistently increased during normal-cancer transformation and is a potential oncogenic factor. In addition, the molecular profiles of TJs and GJs were used to stratify colorectal cancer (CRC) patients, where subtypes characterized by high GJ levels and low TJ levels exhibited enhanced mesenchymal signals. Importantly, we propose that leiomodin 1 (LMOD1) is biphasic, with features of both TJs and GJs. LMOD1 not only promotes the activation of cancer-associated fibroblasts (CAFs) but also inhibits the Epithelial-mesenchymal transition (EMT) program in cancer cells. In conclusion, these findings demonstrate the molecular heterogeneity of CC and provide new insights into further understanding of TME heterogeneity.
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Fibroblastos Associados a Câncer , Comunicação Celular , Neoplasias Colorretais , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Microambiente Tumoral , Animais , Humanos , Fibroblastos Associados a Câncer/metabolismo , Fibroblastos Associados a Câncer/patologia , Linhagem Celular Tumoral , Neoplasias Colorretais/patologia , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/genética , Transição Epitelial-Mesenquimal/genética , Junções Comunicantes/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Análise Espaço-Temporal , Junções Íntimas/metabolismo , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Autoantígenos/genética , Autoantígenos/metabolismoRESUMO
BACKGROUND: Despite recent advances in therapeutic regimens, the prognosis of acute myeloid leukemia (AML) remains poor. Following our previous finding that interleukin-33 (IL-33) promotes cell survival along with activated NF-κB in AML, we further investigated the role of NF-κB during leukemia development. METHODS: Flow cytometry was performed to value the apoptosis and proliferation. qRT-PCR and western blot were performed to detect the expression of IL-6, active caspase 3, BIRC2, Bcl-2, and Bax, as well as activated NF-κB p65 and AKT. Finally, xenograft mouse models and AML patient samples were used to verify the findings observed in AML cell lines. RESULTS: IL-33-mediated NF-κB activation in AML cell lines contributes to a reduction in apoptosis, an increase in proliferation rate as well as a decrease in drug sensitivity, which were reversed by NF-κB inhibitor, Bay-117085. Moreover, IL-33 decreased the expression of active caspase-3 while increasing the levels of BIRC2, Bcl-2, and Bax, and these effects were blocked by Bay-117085. Additionally, NF-κB activation induced by IL-33 increases the production of IL-6 and autocrine activation of AKT. Co-culture of bone marrow stroma with AML cells resulted in increased IL-33 expression by leukemia cells, along with decreased apoptosis level and reduced drug sensitivity. Finally, we confirmed the in vivo pro-tumor effect mediated by IL-33/ NF-κB axis using a xenograft model of AML. CONCLUSION: Our data indicate that IL-33/IL1RL1-dependent signaling contributes to AML cell activation of NF-κB, which in turn causes autocrine IL-6-induced activation of pAKT, supporting IL-33/NF-κB/pAKT as a potential target for AML therapy.
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Apoptose , Resistencia a Medicamentos Antineoplásicos , Interleucina-33 , Leucemia Mieloide Aguda , NF-kappa B , Humanos , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patologia , Leucemia Mieloide Aguda/tratamento farmacológico , Apoptose/efeitos dos fármacos , NF-kappa B/metabolismo , Animais , Interleucina-33/metabolismo , Camundongos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Transdução de Sinais/efeitos dos fármacos , Masculino , Ensaios Antitumorais Modelo de Xenoenxerto , Proteínas Proto-Oncogênicas c-akt/metabolismoRESUMO
The present study utilizes styrene as a raw material to prepare hyper-cross-linked polystyrene nanospheres (HPSs) through the Friedel-Crafts reaction, establishing stable covalent bond structures within the polymer chains. The hydrophilic polystyrene nanospheresâTMA@SHPSs were successfully synthesized via sulfonation and ion exchange reactions, demonstrating exceptional properties in reducing friction and wear. Compared with pure water, the addition of 4.0 wt % TMA@SHPSs results in a 62.2% reduction in the friction coefficient, accompanied by a significant decrease to 1.17 × 105 µm3 in wear volume. The results demonstrate that TMA@SHPSs, as water-based lubrication additives, generate composite protective films (tribo-chemical protective films and physical protective films) during the friction process, which effectively prevents direct contact between the friction pairs and achieves remarkable antifriction and antiwear effects. The results of the antimicrobial activity test indicate that TMA@SHPSs demonstrate exceptional antibacterial efficacy due to the bacteriostatic effect induced by hydration and the bactericidal properties of quaternary ammonium cations.
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In this work, the functionalized covalent organic framework (COF) was prepared via a convenient ball milling process. The aldehyde group terminated COF-F reacted with amino thiadiazole in the ball milling jar under mechanical forces; hence, the thiadiazole functionalized COF-F was obtained and denoted as Thdz@COF-F. The as-prepared Thdz@COF-F serves as an oil-based lubricant additive and exhibits remarkable tribological properties, which can reduce the average friction coefficient of base oil from 0.169 to 0.102 and decrease the wear volume by 87.0%. The antifriction and antiwear performances are mainly due to the repairing effect of Thdz@COF-F nanoparticles and the protective tribo-film that averts the direct contact of friction pairs. In addition, through the ball milling method, triazole and thiazole functionalized COF-F were also prepared and represented good lubrication performance, demonstrating the feasibility of this mechanochemical synthesis method for functionalized COFs.
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Antigenically divergent H7N9 viruses pose a potential threat to public health, with the poor immunogenicity of candidate H7N9 vaccines demonstrated in clinical trials underscoring the urgent need for more-effective H7N9 vaccines. In the present study, mice were immunized with various doses of a suspended-MDCK-cell-derived inactivated H7N9 vaccine, which was based on a low-pathogenic H7N9 virus, to assess cross-reactive immunity and cross-protection against antigenically divergent H7N9 viruses. We found that the CRX-527 adjuvant, a synthetic TLR4 agonist, significantly enhanced the humoral immune responses of the suspended-MDCK-cell-derived H7N9 vaccine, with significant antigen-sparing and immune-enhancing effects, including robust virus-specific IgG, hemagglutination-inhibiting (HI), neuraminidase-inhibiting (NI), and virus-neutralizing (VN) antibody responses, which are crucial for protection against influenza virus infection. Moreover, the CRX-527-adjuvanted H7N9 vaccine also elicited cross-protective immunity and cross-protection against a highly pathogenic H7N9 virus with a single vaccination. Notably, NI and VN antibodies might play an important role in cross-protection against lethal influenza virus infections. This study showed that a synthetic TLR4 agonist adjuvant has a potent immunopotentiating effect, which might be considered worth further development as a means of increasing vaccine effectiveness.
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Anticorpos Antivirais , Imunidade Humoral , Subtipo H7N9 do Vírus da Influenza A , Vacinas contra Influenza , Camundongos Endogâmicos BALB C , Infecções por Orthomyxoviridae , Receptor 4 Toll-Like , Vacinas de Produtos Inativados , Animais , Subtipo H7N9 do Vírus da Influenza A/imunologia , Receptor 4 Toll-Like/agonistas , Receptor 4 Toll-Like/imunologia , Vacinas contra Influenza/imunologia , Vacinas contra Influenza/administração & dosagem , Camundongos , Anticorpos Antivirais/imunologia , Cães , Células Madin Darby de Rim Canino , Vacinas de Produtos Inativados/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Infecções por Orthomyxoviridae/imunologia , Feminino , Anticorpos Neutralizantes/imunologia , Proteção Cruzada/imunologia , Adjuvantes Imunológicos/administração & dosagem , Adjuvantes Imunológicos/farmacologia , Adjuvantes de Vacinas , Imunoglobulina G/imunologia , Imunoglobulina G/sangueRESUMO
This study aimed to apply machine learning (ML) techniques to develop and validate a risk prediction model for post-stroke lower extremity deep vein thrombosis (DVT) based on patients' limb function, activities of daily living (ADL), clinical laboratory indicators, and DVT preventive measures. We retrospectively analyzed 620 stroke patients. Eight ML models-logistic regression (LR), support vector machine (SVM), random forest (RF), decision tree (DT), neural network (NN), extreme gradient boosting (XGBoost), Bayesian (NB), and K-nearest neighbor (KNN)-were used to build the model. These models were extensively evaluated using ROC curves, AUC, PR curves, PRAUC, accuracy, sensitivity, specificity, and clinical decision curves (DCA). Shapley's additive explanation (SHAP) was used to determine feature importance. Finally, based on the optimal ML algorithm, different functional feature set models were compared with the Padua scale to select the best feature set model. Our results indicated that the RF algorithm demonstrated superior performance in various evaluation metrics, including AUC (0.74/0.73), PRAUC (0.58/0.58), accuracy (0.75/0.77), and sensitivity (0.78/0.80) in both the training set and test set. DCA analysis revealed that the RF model had the highest clinical net benefit. SHAP analysis showed that D-dimer had the most significant influence on DVT, followed by age, Brunnstrom stage (lower limb), prothrombin time (PT), and mobility ability. The RF algorithm can predict post-stroke DVT to guide clinical practice.
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Bats are responsible for the zoonotic transmission of several major viral diseases, including those leading to the 2003 SARS outbreak and likely the ongoing COVID-19 pandemic. While comparative genomics studies have revealed characteristic adaptations of the bat innate immune system, functional genomic studies are urgently needed to provide a foundation for the molecular dissection of the viral tolerance in bats. Here we report the establishment of genome-wide RNA interference (RNAi) and CRISPR libraries for the screening of the model megabat, Pteropus alecto. We used the complementary RNAi and CRISPR libraries to interrogate P. alecto cells for infection with two different viruses: mumps virus and influenza A virus, respectively. Independent screening results converged on the endocytosis pathway and the protein secretory pathway as required for both viral infections. Additionally, we revealed a general dependence of the C1-tetrahydrofolate synthase gene, MTHFD1, for viral replication in bat cells and human cells. The MTHFD1 inhibitor, carolacton, potently blocked replication of several RNA viruses, including SARS-CoV-2. We also discovered that bats have lower expression levels of MTHFD1 than humans. Our studies provide a resource for systematic inquiry into the genetic underpinnings of bat biology and a potential target for developing broad-spectrum antiviral therapy.
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Aminoidrolases/genética , COVID-19/genética , Formiato-Tetra-Hidrofolato Ligase/genética , Metilenotetra-Hidrofolato Desidrogenase (NADP)/genética , Complexos Multienzimáticos/genética , Pandemias , Aminoidrolases/antagonistas & inibidores , Animais , Antivirais/uso terapêutico , COVID-19/virologia , Linhagem Celular , Quirópteros/genética , Quirópteros/virologia , Formiato-Tetra-Hidrofolato Ligase/antagonistas & inibidores , Humanos , Metilenotetra-Hidrofolato Desidrogenase (NADP)/antagonistas & inibidores , Antígenos de Histocompatibilidade Menor , Complexos Multienzimáticos/antagonistas & inibidores , Vírus de RNA/genética , SARS-CoV-2/patogenicidade , Replicação Viral/genética , Tratamento Farmacológico da COVID-19RESUMO
Metal-backboned polymers (MBPs), with a unique backbone consisting of bonded metal atoms, are promising for optic, electric, magnetic, and thermoelectric fields. However, the application of MBP remains relatively understudied. Here, we develop a shear-induced orientation method to construct a flexible nickel-backboned polymer/carbon nanotube (NBP/CNT) thermoelectric composite fiber. It demonstrated a power factor of 719.48â µW â m-1 K-2, which is ca. 3.5â times as high as the bare CNT fiber. Remarkably, with the regulation of carrier mobility and carrier concentration of NBP, the composite fiber further showed simultaneous increases in electrical conductivity and Seebeck coefficient in comparison to the bare CNT fiber. The NBP/CNT fiber can be integrated into fabrics to harvest thermal energy of human body to generate an output voltage of 3.09â mV at a temperature difference of 8â K. This research opens a new avenue for the development of MBPs in power supply.
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Perovskite light-emitting diodes (PeLEDs) that can be air-processed promises the development of displaying optoelectronic device, while is challenged by technical difficulty on both the active layer and hole transport layer (HTL) caused by the unavoidable humidity interference. Here, we propose and validate that, planting the polymer brush with tailored functional groups in inorganic HTL, provides unique bilateral embedded anchoring that is capable of simultaneously addressing the n phases crystallization rates in the active layer as well as the deteriorated particulate surface defects in HTL. Exemplified by zwitterionic polyethyleneimine-sulfonate (PEIS) in present study, its implanting in NiOx HTL offers abundant nuclei sites of amino and sulfonate groups that balance the growth rate of different n phases in quasi-2D perovskite films. Moreover, the PEIS effectively nailed the interfacial contact between perovskite and NiOx, and reduced the particulate surface defects in HTL, leading to the enhanced PLQY and stability of large-area blue perovskite film in ambient air. By virtue of these merits, present work achieves the first demonstration of the air-processed blue PeLEDs in large emitting area of 1.0 cm2 with peak external quantum efficiency (EQE) of 2.09 %, which is comparable to the similar pure-bromide blue PeLEDs fabricated in glovebox.
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It is facing a tremendous challenge to develop the desirable hybrids for photocatalytic H2 generation by integrating the advantages of a single semiconductor. Herein, an all-sulfide ZnIn2 S4 /CdS/PdS heterojunction is constructed for the first time, where CdS and PdS nanoparticles anchor in the spaces of ZnIn2 S4 micro-flowers due to the confinement effects. The morphology engineering can guarantee rapid charge transfer owing to the short carrier migration distances and the luxuriant reactive sites provided by ZnIn2 S4 . The S-scheme mechanism between ZnIn2 S4 and CdS assisted by PdS cocatalyst is testified by in situ irradiated X-ray photoelectron spectroscopy and electron paramagnetic resonance (EPR), where the electrons and holes move in reverse driven by work function difference and built-in electric field at the interfaces. The optimal ZnIn2 S4 /CdS/PdS performs a glaring photocatalytic activity of 191.9 µmol h-1 (10 mg of catalyst), and the largest AQE (apparent quantum efficiency) can reach a high value of 26.26%. This work may afford progressive tactics to design multifunctional photocatalysts.
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The interface adhesion plays a key role between rigid metal and elastomer in compressible and stretchable conductors. However, the poor interfacial adhesion hinders their wide applications. To strengthen the interface adhesion, herein, a combination strategy of structure interlocking and polymer bridging is designed by introducing a method of subsurface-initiated atom transfer radical polymerization (sSI-ATRP). This method can make polymer brush root in polydimethylsiloxane (PDMS) subsurface, on this basis, metals further grow from subsurface to surface of PDMS via electroless deposition. As a result, the adhesive strength (≈2.5 MPa) between metal layer and PDMS elastomer is 4 times higher than that made by common polymer modification. As a demonstration, pressure sensor is constructed by using as-prepared compressible 3D Cu sponge as a top electrode and paper-based interdigited metal electrode as a bottom electrode. The device sensitivity can reach up to 961.2 kPa-1 and the durability can arrive at 3 000 cycles without degradation. Thus, this proposed interface-enhancement strategy for rigid-soft materials can significantly promote the performance of piezoresistive pressure sensors based on 3D conductive sponge. In the future, it would also be expanded to the fabrication of stretchable conductors and extensively applied in other flexible and wearable electronics.
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The tissue factor (TF/CD142) expressed by mesenchymal stromal cells (MSCs) has been regarded as a safety concern in clinical applications as it may trigger thrombosis when MSCs administered intravenously. Human placental allogenic stromal cells (ASCs) are culture-expanded, undifferentiated MSC-like cells derived from full-term postpartum placenta and possess immunomodulatory and pro-angiogenic activities, however, express TF. Here we performed CRISPR/Cas9-mediated TF gene knock out (TFKO) in ASCs, leading to significantly lower TF expression, activity and thrombotic effects. ASCs' characteristics including expansion, expression of phenotypic markers and secretory profile remained unchanged in edited cells, and their immunomodulatory activities, which are functionally relevant to therapeutic applications, were not affected upon TFKO. Taken together, this study provides a feasible strategy which could improve the clinical safety features of MSC-based cell therapy by CRISRP/Cas9-mediated TF gene knock out.
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Tromboplastina , Trombose , Feminino , Gravidez , Humanos , Tromboplastina/genética , Sistemas CRISPR-Cas/genética , Placenta , Células EstromaisRESUMO
Onion-like carbon (OLC) is a kind of carbon material with a graphene-like structure and large interlayer spacing, favorable to a good lubricating performance. Herein, a facile method is presented for the preparation of functionalized OLC nanoparticles from candle soot with surface modification. The OLC nanoparticles are collected from combustion soot with candle burning via a simple heat treatment, and then the zwitterionic polymer (polyethylenimine-quaternized derivative, PEIS) can self-assemble onto the OLC surface with epigallocatechin gallate via Michael addition and Schiff-base reaction, thus obtaining PEIS-functionalized OLC nanoparticles (PEIS@OLC). The grafting zwitterionic polymer PEIS endows the OLC nanoparticles with good hydrophilic performance, so the as-obtained PEIS@OLC exhibits outstanding dispersion and lubricating property as a water-based lubricant additive. Compared to pure water, the average coefficient of friction decreases to 0.110 from 0.512, and the corresponding wear volume is reduced by 61.02% with 1.5 wt % addition. The improved lubricating property is mainly due to the synergetic effect of the protective film induced by the tribochemical reaction and the hydration film of zwitterionic polymer PEIS. Besides, the OLC nanoparticles could also display the nanoscale rolling and repairing effects at the friction contact interface, resulting in reduction of friction and wear.
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A highly efficient heterogeneous copper(I)-catalyzed cross-coupling of trialkylsilylethynes with N-tosylhydrazones has been achieved in dioxane at 90-110 °C via the Cu carbene migratory insertion with an SBA-15-immobilized l-proline-Cu(I) complex [SBA-15-l-Proline-CuI] as the catalyst and LiOtBu as the base, leading to the formation of C(sp)-C(sp3) bonds. The reaction generates a wide variety of alkyltrialkylsilylalkynes in moderate to high yields. This new heterogenized copper(I) complex exhibits a comparable catalytic efficiency to homogeneous CuI and can be easily recovered through a simple centrifugation process and is recyclable up to 12 times without a remarkable loss of activity.
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Surface-initiated atom transfer radical polymerization (SI-ATRP) is one of the most popular methods for surface modifications with functional polymer films, which has attracted significant attention in recent years. Herein, a facile method of gallium-based liquid metal (GLM) nanodroplets mediated SI-ATRP to prepare polymer brushes on GLM surfaces is reported. The ATRP initiator modified GLM (GLM-Br) nanodroplets act as a substrate for the in situ SI-ATRP and participate as a reducing agent to reduce Cu(II) deactivators to Cu(I) activators. UV-vis spectra confirm the feasibility of the in situ SI-ATRP and indicate that the thickness and density of polymer brushes play an important role in performing a successful ATRP on GLM nanodroplets surfaces. Homo- and block copolymers, poly(3-sulfopropyl methacrylate potassium salt) (PSPMA) and poly((2-dimethylamino)ethyl methacrylate-b-(3-sulfopropyl methacrylate potassium salt)) P(DMAEMA-b-SPMA) are successfully grafted to the GLM nanodroplets. Polymer brushes modified GLM nanodroplets show potential applications such as friction reduction and oil-water emulsion separation. GLM nanodroplets mediated SI-ATRP provides a novel and robust approach to preparing multifunctional GLM nanodroplets for different applications.
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Polímeros , Propriedades de Superfície , PolimerizaçãoRESUMO
Nevus sebaceus (NS) is a congenital hamartoma of skin structures including the epidermis, sweat sebaceous glands, and hair follicles. It is known that secondary tumors can occur in NS. However, secondary metastatic malignancies are rare. Basosquamous carcinoma (BSC) is an aggressive type of basal cell carcinoma (BCC) characterized by squamous differentiation. Herein, we report a case of metastatic BSC that developed in a 73-year-old male with NS. The clinical presentation of this patient was that of an ulcerative nodule developing in a longstanding plaque-like lesion consistent with NS. Histopathological examination revealed characteristic features of BCC with some areas of squamous differentiation in addition to the structure of a typical NS. Immunohistochemical expression of Ber-EP4, AE1/AE3, and epithelial membrane antigen helped to make the diagnosis of BSC.