Isocyanide-based multicomponent reactions are among the most powerful synthetic tools available. Particularly, the isocyanide-based Ugi reaction can allow rapid preparation of
α
-aminoacyl amide ...derivatives and polyazaheterocycles with extensive pharmaceutical applications. Moreover, bridged polyazaheterocycles, including one or more quaternary carbon centers, can be constructed via the Ugi cascade reaction in a few steps. This review will emphasize synthesis and bioactivities of bridged compounds with quaternary centers constructed through Ugi cascade reactions.
Superionic Cu 2 Se-based thermoelectric materials have attracted extensive attention in recent years due to their ultralow lattice thermal conductivity and high dimensionless figure of merit ( zT ). ...Inspired by the effectiveness of heavy-element doping in reducing lattice thermal conductivity in various thermoelectric materials, we investigate the Ag-doping effects on the thermoelectric properties of Cu 2 Se nanocrystals made via a facile solvothermal method and subsequently spark plasma sintering. Based on the single parabolic band model analysis of thermoelectric properties, it has been found that the isoelectronic Ag dopant leads to an enhanced carrier concentration and significantly reduced carrier mobility, as well as a reduced electrical conductivity and power factor. Moreover, the reduced disorder-level of cations leads to an extraordinarily enhanced lattice thermal conductivity. All these result in a zT reduction for Ag-doped Cu 2 Se. This work systematically studies the influence of Ag dopants on the thermoelectric performance of Cu 2 Se and indicates that the Ag-doping is less promising in enhancing it.
Immunoglobulin G4-related disease (IgG4-RD) is a newly recognized fibro-inflammatory condition. Forty-two cases with immunoglobulin G4-related sialadenitis (IgG4-RS) confirmed by histopathological ...and immunohistochemical assessment were studied to clarify the clinicopathologic characteristics of the salivary glands involved in IgG4-RS, especially the relationship between the histopathologic features and function of salivary glands or serum levels of IgG4.
Clinical, serologic, imaging and histopathological data of these cases were analyzed. CT volumes of submandibular, parotid, and lacrimal glands were calculated. The saliva flow rate was measured. Scintigraphy with 99mTc-pertechnetate was undertaken in 31 cases, and the concentration index (CI) and secretion index (SI) was calculated. Relationships between fibrosis severity and salivary gland function or serum IgG4 levels were analyzed.
The first symptom was swelling of bilateral submandibular or lacrimal glands. Physical examination showed multiple bilateral major salivary glands (including sublingual and accessory parotid glands) and lacrimal glands were enlarged in IgG4 RS. Multiple enlarged cervical lymph nodes were noted in 30 patients. Saliva flow at rest was lower than normal in 34 cases; stimulated saliva flow was lower than normal in 15 cases. Secretory function was reduced more severely in the submandibular glands than in the parotid glands. Serum levels of IgG4 were elevated in 95.2% of cases and 78.6% patients had increased IgE levels. Serum IgG4 level was higher and saliva secretion lower as glandular fibrosis increased.
Prominent changes in the morphology, histology, immunohistochemistry and secretion of the major salivary glands of IgG4-RS patients were accompanied by involvement of the lacrimal glands and cervical lymph nodes. Elevated IgE, allergic history, eosinophil infiltration suggest allergic reactions as a potential pathogenesis of IgG4-RS. Severity of glandular fibrosis correlated with salivary function and serum levels of IgG4.
Patients of diabetes mellitus urgently need noninvasive and continuous glucose monitoring in daily point-of-care. As the tear glucose concentration has a positive correlation with that in blood, the ...hydrogel colloidal crystal integrated into contact lens possesses promising potential for noninvasive monitoring of glucose in tears. This paper presents a new glucose-responsive sensor, which consists a crystalline colloidal array (CCA) embedded in hydrogel matrix, attached onto a rigid gas permeable (RGP) contact lens. This novel sensing lens is able to selectively diffract visible light, whose wavelength shifts between 567 and 468 nm according to the alternation of the glucose concentration between 0 and 50 mM and its visible color change between reddish yellow, green, and blue. The detection limit of responsive glucose concentration can be reduced to 0.05 mM. Its combination with a contact lens endows it with excellent biocompatibility and portability, which shows great possibility for it to push the development of glucose-detecting devices into new era.
A novel photoredox-catalyzed radical addition of methylene-2-oxazolines has been developed under visible light irradiation to synthesize monofluorooxazoles with a quaternary carbon center using ...2-bromo-2-fluoro-3-oxo-3-phenylpropionates as radical source. This method with a simple protocol, scalability and high yield offers a facile path to get diverse monofluorinated oxazoles with quaternary C-F centers, which are a class of highly valuable motifs and synthons.
A photoredox-catalyzed radical addition of methylene-2-oxazolines has been developed under visible light irradiation to synthesize monofluorooxazoles with quaternary C-F centers using 2-bromo-2-fluoro-3-oxo-3-phenylpropionates as radical source.
Abstract
Owing to the capability of the conversion between thermal energy and electrical energy and their advantages of light weight, compactness, noise-free operation, and precision reliability, ...wearable thermoelectrics show great potential for diverse applications. Among them, weavable thermoelectrics, a subclass with inherent flexibility, wearability, and operability, find utility in harnessing waste heat from irregular heat sources. Given the rapid advancements in this field, a timely review is essential to consolidate the progress and challenge. Here, we provide an overview of the state of weavable thermoelectric materials and devices in wearable smart textiles, encompassing mechanisms, materials, fabrications, device structures, and applications from recent advancements, challenges, and prospects. This review can serve as a valuable reference for researchers in the field of flexible wearable thermoelectric materials and devices and their applications.
Periodontitis is a major cause of tooth loss in adults and periodontal ligament stem cells (PDLSCs) is the most favorable candidate for the reconstruction of tissues destroyed by periodontal ...diseases. However, pathological alterations caused by inflammatory insults might impact the regenerative capacities of these cells. Bone-marrow-derived human mesenchymal stem cells (hBMSCs) would accelerate alveolar bone regeneration by transplantation, compared to PDLSCs. Therefore, a better understanding of the osteogenic differentiation between PDLSCs and BMSCs in inflammatory microenviroments is therefore warranted. In this study, human PDLSCs were investigated for their stem cell characteristics via analysis of cell surface marker expression, colony forming unit efficiency, osteogenic differentiation and adipogenic differentiation, and compared to BMSCs. To determine the impact of both inflammation and the NF-κβ signal pathway on osteogenic differentiation, cells were challenged with TNF-α under osteogenic induction conditions and investigated for mineralization, alkaline phosphatase (ALP) activity, cell proliferation and relative genes expression. Results showed that PDLSCs exhibit weaker mineralization and ALP activity compared to BMSCs. TNF-α inhibited genes expression of osteogenic differentiation in PDLSCs, while, it stimulates gene expressions (BSP and Runx2) in BMSCs. Enhanced NF-κβ activity in PDLSCs decreases expression of Runx2 but it does not impede the osteogenic differentiation of BMSCs. Taken together, these results may suggest that the BMSCs owned the stronger immunomodulation in local microenvironment via anti-inflammatory functions, compared to PDLSCs.
•The significant difference on the osteogenesis between PDLSCs and BMSCs was showed in inflammatory microenvironments.•TNF-α strongly inhibited PDLSCs mineralization and ALP activity but stimulated the mineralization of BMSCs.•TNF-α inhibited genes expression of osteogenic differentiation in PDLSCs, while, it stimulates gene expressions (BSP and Runx2) in BMSCs.•Enhanced NF-κB activity in PDLSCs decreases expression of Runx2 but it does not impede the osteogenic differentiation of BMSCs.
Bi2Te3-based alloys are the best thermoelectric materials near room temperature and Bi2(TeSe)3 alloys are their typical n-type ones. However, the dimensionless figure of merit ZT of the bulk ...Bi2(TeSe)3 is normally less than 1.0 despite various delicate and time-consuming preparations associated with complex post-treatments. Here, via liquid state manipulation (LSM), we obtained a high ZT for bulk n-type Bi2Te2.4Se0.6 ingot direction-solidified with high temperature-gradient at a suitable growth rate. With the maximum ZT = 1.22 at 477K, its average value (1.09) between 300 and 575K is the highest among those of all the bulk Bi2(TeSe)3 fabricated so far. Specifically, with proper structure texturing, LSM obviously raises the Seebeck coefficient due to the increased effective mass, with almost unaltered electrical conductivity. Moreover, as growth rate decreases, the enhanced texturing boosts the electrical conductivity, but raises the thermal conductivity along the growth direction. More significantly, at the same direction growth condition, LSM can increase nanoscale particles, dislocations and atomic-scale lattice distortions, resulting in substantially reduced lattice thermal conductivity. Consequently, via LSM and suitable texturing, the bulk n-type Bi2Te2.4Se0.6 with outstanding ZT is directly obtained without complex post-treatments. This work provides a novel strategy for optimizing performance of thermoelectric materials with the merit of easy large-scale fabrication.
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•Simultaneous optimization of S, σ and κ due to liquid state manipulation.•A high ZT of 1.22, which represents the highest ZT for n-type Bi2(TeSe)3 alloys.•A great methodological innovation for preparing ultrahigh TE performance materials.•The highest average ZT value of 1.09 for Bi2Te3-xSex-based alloys reported so far.
Natural halloysite nanotubes (HNTs), with nanotubular structure, are attracting considerable attention in recent years. The hollow tubular structure allows HNTs to play an important role in drug ...delivery system as drug carriers. However, the wide applications of HNTs in biomedicine have been hampered by the lack of sufficient intracellular researches so far. In this study, we systemically investigated the transport mechanisms of HNTs in A549 living cells. The colocalization and inhibition experiments illustrated FITC-labeled HNTs were readily internalized into cells by both clathrin- and caveolae-dependent endocytosis, and the transport pathway of HNTs is an actin- and microtubule-associated process via Golgi apparatus and lysosome. Meanwhile, the cell cycle assay clarified that HNTs can prompt the intracellular transportation of gemcitabine and enhance the gemcitabine concentration in A549 tumor cells. Such elucidation of intracellular transport pathway of HNTs offers insights into the site-specific delivery and cellular internalization of HNTs, which provide a reasonable guidance for the design of novel drug delivery system.
Previous researches on large animal models of diabetic cardiomyopathy were insufficient. The aim of this study was to evaluate early changes in left ventricular (LV) function and morphology in ...diabetic pigs using a cardiac magnetic resonance (CMR) time-volume curve and feature tracking technique.
Streptozotocin (STZ) was used to induce diabetic in sixteen pigs. 3.0T MRI scanned the pig's heart before and 2, 6, 10 and 16 months after modelling. CMR biomarkers, including time-volume curve and myocardial strain, were compared to analyse the longitudinal changes in LV function and morphology. Pearson correlation was used to evaluate the relationship between LV strain and remodelling. Cardiac specimens were obtained at 6, 10, and 16 months after modelling to observe the myocardial ultrastructural and microstructure at different courses of diabetes.
Twelve pigs developed diabetes. The 80% diastolic volume recovery rate (DVR) at 6 months after modelling was significantly higher than that before modelling (0.78 ± 0.08vs. 0.67 ± 0.15). The LV global longitudinal peak strain (GLPS) (- 10.21 ± 3.15 vs. - 9.74 ± 2.78 vs. - 9.38 ± 3.71 vs. - 8.71 ± 2.68 vs. - 6.59 ± 2.90%) altered gradually from the baseline data to 2, 6, 10 and 16 months after modelling. After 16 months of modelling, the LV remodelling index (LVRI) of pigs increased compared with that before modelling (2.19 ± 0.97 vs. 1.36 ± 0.45 g/ml). The LVRI and myocardial peak strain were correlated in diabetic pigs (r= - 0.40 to - 0.54), with GLPS being the most significant. Electron microscopy and Masson staining showed that myocardial damage and fibrosis gradually increased with the progression of the disease.
Intravenous injection of STZ can induce a porcine diabetic cardiomyopathy model, mainly characterized by decreased LV diastolic function and strain changes accompanied by myocardial remodelling. The changes in CMR biomarkers could reflect the early myocardial injury of diabetic cardiomyopathy.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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