Two-dimensional (2D) correlation ATR-FTIR spectroscopy was used to study the dynamic diffusion behavior and state of water in syndiotactic polypropylene (S-PP). The 2D asynchronous spectra of water bending band clearly reveal that there are three separate bands in the 1800-1500 cm -1 region. These three bands at 1676, 1645, and 1592 cm -1 are assigned, respectively, to the aggregated water with strong hydrogen bond, the aggregated water with moderate strong hydrogen bond, and the "free water". On the basis of this approach, the following mechanism for the diffusion process of water in S-PP has been proposed: the aggregated water molecules first diffuse into the polymer during the diffusion process. The water molecules with strong hydrogen bond will diffuse slower than water with moderate strong hydrogen bond because of their large size. In the late stage of the diffusion process, some aggregated water molecules in the PP matrix are forced to dissolve into the "free water" form.
Since a Halbach array exhibits a number of attractive features, it has been increasingly applied to different market sectors, including aerospace, industrial, domestic, renewable and healthcare and so on. The need of fast global optimisation, cost-effective design and physical understanding of the relationship between parameters and performance requires a powerful analytical model. Hence, this study develops a general analytical model which is capable of predicting the electromagnetic performance of slotted/slotless permanent magnet (PM) brushless machines with both even-and odd-segment Halbach array, having different magnet remanence, magnetisation angle and arc for each single magnet segment. The emphasis has been on the magnetisation which is the key in analytical modelling of PM machines having a segmented Halbach array and its investigation. The validity of proposed analytical model is extensively examined by finite-element analyses, together with its applications for global optimisation and comparative study.
Ferroptosis, a newly discovered form of regulated cell death, is emerging as a promising approach to tumor therapy. However, the spatiotemporal control of cell-intrinsic Fenton chemistry to modulate tumor ferroptosis remains challenging. Here, we report an oxazine-based activatable molecular assembly (PTO-Biotin Nps), which is capable of triggering the lysosomal dysfunction-mediated Fenton pathway with excellent spatiotemporal resolution via near-infrared (NIR) light to evoke ferroptosis. In this system, a pH-responsive NIR photothermal oxazine molecule was designed and functionalized with a tumor-targeting hydrophilic biotin-poly(ethylene glycol) (PEG) chain to engineer well-defined nanostructured assemblies within a single-molecular framework. PTO-Biotin Nps possesses a selective tropism to lysosome accumulation inside tumor cells, accommodated by its enhanced photothermal activity in the acidic microenvironment. Upon NIR light activation, PTO-Biotin Nps promoted lysosomal dysfunction and induced cytosolic acidification and impaired autophagy. More importantly, photoactivation-mediated lysosomal dysfunction via PTO-Biotin Nps was found to markedly enhance cellular Fenton reactions and evoke ferroptosis, thereby improving antitumor efficacy and mitigating systemic side effects. Overall, our study demonstrates that the molecular engineering approach of pH-responsive photothermal oxazine assemblies enables the spatiotemporal modulation of the intrinsic ferroptosis mechanism, offering a novel strategy for the development of metal-free Fenton inducers in antitumor therapy.
Background Ferroptosis and iron-metabolism are regulated by Long non-coding RNAs (lncRNAs) in ovarian cancer (OC). Therefore, a comprehensive analysis of ferroptosis and iron-metabolism related lncRNAs (FIRLs) in OC is crucial for proposing therapeutic strategies and survival prediction. Methods In multi-omics data from OC patients, FIRLs were identified by calculating Pearson correlation coefficients with ferroptosis and iron-metabolism related genes (FIRGs). Cox-Lasso regression analysis was performed on the FIRLs to screen further the lncRNAs participating in FIRLs signature. In addition, all patients were divided into two robust risk subtypes using the FIRLs signature. Receiver operator characteristic (ROC) curve, Kaplan–Meier analysis, decision curve analysis (DCA), Cox regression analysis and calibration curve were used to confirm the clinical benefits of FIRLs signature. Meanwhile, two nomograms were constructed to facilitate clinical application. Moreover, the potential biological functions of the signature were investigated by genes function annotation. Finally, immune microenvironment, chemotherapeutic sensitivity, and the response of PARP inhibitors were compared in different risk groups using diversiform bioinformatics algorithms. Results The raw data were randomized into a training set (n = 264) and a testing set (n = 110). According to Pearson coefficients between FIRGs and lncRNAs, 1075 FIRLs were screened for univariate Cox regression analysis, and then LASSO regression analysis was used to construct 8-FIRLs signature. It is worth mentioning that a variety of analytical methods indicated excellent predictive performance for overall survival (OS) of FIRLs signature (p < 0.05). The multivariate Cox regression analysis showed that FIRLs signature was an independent prognostic factor for OS (p < 0.05). Moreover, significant differences in the abundance of immune cells, immune-related pathways, and drug response were excavated in different risk subtypes (p < 0.05). Conclusion The FIRLs signature can independently predict overall survival and therapeutic effect in OC patients.
The facet-specific interaction between molecules and crystalline catalysts, such as titanium dioxides (TiO), has attracted much attention due to possible facet-dependent reactivity. Using surface-sensitive sum-frequency vibrational spectroscopy, we have studied how methanol interacts with different common facets of crystalline TiO, including rutile(110), (001), (100), and anatase(101), under ambient temperature and pressure. We found that methanol adsorbs predominantly in the molecular form on all of the four surfaces, while spontaneous dissociation into methoxy occurs preferentially when these surfaces become defective. Extraction of Fermi resonance coupling between stretch and bending modes of the methyl group in analyzing adsorbed methanol spectra allows determination of the methanol adsorption isotherm. The isotherms obtained for the four surfaces are nearly the same, yielding two adsorbed Gibbs free energies associated with two different adsorption configurations singled out by ab initio calculations. They are () ∼-20 kJ/mol for methanol with its oxygen attached to a low-coordinated surface titanium, and () ∼-5 kJ/mol for methanol hydrogen-bonded to a surface oxygen and a neighboring methanol molecule. Despite similar adsorption energetics, the Fermi resonance coupling strength for adsorbed methanol appears to depend sensitively on the surface facet and coverage.
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