ABSTRACT
Purpose: To investigate the treatment response and toxicity of the combination of induction chemotherapy (IC) and PD-1 inhibitor in locally advanced nasopharyngeal carcinoma (LANPC). Methods: Patients with stage III-IVA NPC who received IC or IC + PD-1 inhibitor were included. The chi-square test and multivariate logistic regression analysis were used for statistical analysis. Results: A total of 225 patients were identified, including 193 (85.8%) and 32 (14.2%) who received IC alone and IC + PD-1 inhibitor, respectively. The addition of PD-1 inhibitor to IC significantly improved the tumor response than those treated with IC alone. The complete response (CR), partial response, stable disease, and progressive disease rates of 4.7% vs. 31.3%, 69.4% vs. 62.5%, 24.9% vs. 6.3%, and 1.0% vs. 0% in patients receiving IC alone and IC + PD-1 inhibitor, respectively (P<0.001). The results of the multivariate logistic regression showed that receiving PD-1 inhibitor was an independent predictor influencing the CR rate of patients (odds ratio 9.814, P<0.001). The most common toxicity by using IC and PD-1 inhibitor was hematological toxicity. In terms of non-hematological toxicity, 7 (21.9%) patients experienced thyroid dysfunction and all of them were hyperthyroidism. No grade 5 toxicities were found. In those who received IC and PD-1 inhibitor, the one-year locoregional recurrence-free survival, distant metastasis-free survival, disease-free survival, and overall survival were 100%, 96.9%, 96.9%, and 100%, respectively. Conclusion: The addition of PD-1 inhibitor to IC has promise as an effective treatment approach for LANPC. More studies are expected to provide further insights into the optimal use of this treatment strategy, paving the way for more personalized and effective treatment options for patients with LANPC.
Subject(s)
Induction Chemotherapy , Nasopharyngeal Carcinoma , Nasopharyngeal Neoplasms , Humans , Male , Female , Nasopharyngeal Carcinoma/drug therapy , Nasopharyngeal Carcinoma/mortality , Middle Aged , Adult , Nasopharyngeal Neoplasms/drug therapy , Nasopharyngeal Neoplasms/mortality , Aged , Immune Checkpoint Inhibitors/therapeutic use , Immune Checkpoint Inhibitors/adverse effects , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Treatment Outcome , Neoplasm Staging , Young Adult , Retrospective StudiesABSTRACT
Optically pumped magnetometers (OPMs) have become a favorable tool for magnetoencephalography (MEG) measurement, offering a non-invasive method of measurement. OPMs do not require cryogenic environments, sensors can be more closely aligned with the brain. We employed a passive single-stimulus paradigm in conjunction with OPMs with a sensitivity of 20 fT/ Hz to investigate the auditory response of rats to inter-stimulus interval (ISI) and frequencies, recording the rat auditory event-related magnetic fields (ERMFs). Our findings include: (1) Auditory evoked fields can be detected non-invasively by OPMs; (2) The amplitude of the rat auditory ERMFs varies with changes in ISI, with more pronounced amplitude changes observed after 5 s; (3) When the sound stimulus frequency is altered at the same ISI, the amplitude of the rats ERMFs changes with frequency, indicating significant differences in attention. Our method offers a valuable tool for the clinical application of a single stimulus paradigm and opens up a new avenue for research on the brain magnetic field detections.
ABSTRACT
Purpose: To investigate the survival outcomes and toxicities associated with the addition of nimotuzumab to concurrent chemoradiotherapy (CCRT) in locally advanced nasopharyngeal carcinoma (LANPC) patients who received induction chemotherapy (IC). Methods: Patients with stage III-IVA nasopharyngeal carcinoma who received IC and CCRT between January 2017 and October 2021 were retrospectively included. We aimed to compare the locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS) between patients treated with CCRT+nimotuzumab and CCRT alone. Results: We included 411 patients in the analysis. Of these patients, 267 (65.0%) and 144 (35.0%) had CCRT+nimotuzumab and CCRT alone, respectively. Similar LRFS was found between those with and without nimotuzumab (92.9% vs. 92.6%, p = 0.855). The 3-year DMFS was 88.2% and 76.2% in those with and without nimotuzumab (p = 0.002). The 3-year DFS was 83.4% and 70.6% in those with and without nimotuzumab treatment (p = 0.003). The 3-year OS was 92.1% and 81.1% in those with and without nimotuzumab (p = 0.003). The multivariate Cox regression analysis indicated that the addition of nimotuzumab was independently associated with better DMFS (hazard ratio [HR] 0.606, p = 0.049), DFS (HR 0.613, p = 0.028), and OS (HR 0.497, p = 0.019). No significant differences in major toxicities were found between the two treatment arms, including hematologic toxicities, hepatoxicity, nephrotoxicity, gastrointestinal reactions, and mucositis (all p > 0.05). Conclusion: The addition of nimotuzumab to CCRT after IC in LANPC has shown promising results in improving treatment outcomes and acceptable toxicities.
ABSTRACT
Research on polyurethane-modified asphalt has become very popular. To this end, researchers have explored different ways, such as the use of polyurethane, to improve the road performance of asphalt. However, according to existing experimental research findings, it seems that the use of polyurethane alone cannot completely improve the road performance of asphalt. Therefore, the influence of nano-titanium dioxide and polyurethane on the rheological behavior and anti-ultraviolet aging properties of asphalt was studied. In this research, the rheological and microscopic tests of asphalt were conducted using Dynamic Shear Rheometer, Curved Beam Rheometer, and Fourier Infrared Spectrometer. The results show that the addition of TPU and nano-TiO2 to the asphalt not only improves the high- and low-temperature rheological behavior of the asphalt, but also improves the thermal oxygen resistance and UV aging resistance of the asphalt, and prolongs the use performance. Considering economic factors and environmental influences, among all the selected dosages, 4% TPU and 1% nano-TiO2 had the best performance.
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BACKGROUND: Lung cancer is the leading cause of cancer morbidity and mortality worldwide, however, the individualized treatment is still unsatisfactory. DNA methylation can affect gene regulation and may be one of the most valuable biomarkers in predicting the prognosis of lung adenocarcinoma. This study was aimed to identify methylation CpG sites that may be used to predict lung adenocarcinoma prognosis. METHODS: The Cancer Genome Atlas (TCGA) database was used to detect methylation CpG sites associated with lung adenocarcinoma prognosis and construct a methylation signature model. Then, a Chinese cohort was carried out to estimate the association between methylation and lung adenocarcinoma prognosis. Biological function studies, including demethylation treatment, cell proliferative capacity, and gene expression changes in lung adenocarcinoma cell lines, were further performed. RESULTS: In the TCGA set, three methylation CpG sites were selected that were associated with lung adenocarcinoma prognosis (cg14517217, cg15386964, and cg18878992). The risk of mortality was increased in lung adenocarcinoma patients with the gradual increase level of methylation signature based on three methylation sites levels (HR = 45.30, 95% CI = 26.69-66.83; p < 0.001). The C-statistic value increased to 0.77 when age, gender, and other clinical variables were added to the signature to prediction model. A similar situation was confirmed in Chinese lung adenocarcinoma cohort. In the biological function studies, the proliferative capacity of cell lines was inhibited when the cells were demethylated with 5-aza-2'-deoxycytidine (5-aza-2dC). The mRNA and protein expression levels of SEPT9 and HIST1H2BH (cg14517217 and cg15386964) were downregulated with different concentrations of 5-aza-2dC treatment, while cg18878992 showed the opposite result. CONCLUSION: This study is the first to develop a three-CpG-based model for lung adenocarcinoma, which is a practical and useful tool for prognostic prediction that has been validated in a Chinese population.
Subject(s)
Adenocarcinoma of Lung/genetics , CpG Islands/genetics , DNA Methylation , Lung Neoplasms/genetics , Age Factors , Aged , Asian People , Cell Line, Tumor , Databases, Factual , Female , Genetic Markers , Humans , Male , Middle Aged , Prognosis , Sex FactorsABSTRACT
The catalytic degradation of 1,2-dichloroethane (DCE) at CeO2(111) was investigated using periodic density functional theory calculations corrected by on-site Coulomb interactions. From thorough calculations of possible elementary steps, we are able to identify the lowest energy reaction pathway for the catalytic oxidation of DCE at CeO2(111). It proceeds via two successive C-Cl bond breaking processes to form adsorbed CH2CH2 species, and after further dehydrogenation and C-C bond scission, the surface species are finally oxidized to CO2 and H2O. The surface oxygen vacancies were found to be important for the catalytic decomposition of DCE, by providing the adsorption sites, as well as for charge transfer to favor C-Cl bond breaking. We are also able to illustrate the effect of H2O on the catalytic activity of CeO2(111) for DCE oxidation.
ABSTRACT
A novel heterostructured material, cobalt phosphate-SiO2 mesostructured cellular foams (CoPO-MCF), was successfully synthesized by in situ growth. The material was characterized by X-ray diffraction (XRD), nitrogen sorption, temperature-programmed reduction (H2-TPR and CO-TPR), temperature-programmed desorption of NH3 (NH3-TPD), and X-ray photoelectron spectroscopy (XPS). A ruthenium precursor was readily introduced and highly dispersed on the CoPO nanophases of the CoPO-MCF through an impregnation method. The resulting Ru/CoPO-MCF catalyst exhibited high catalytic activity for the oxidation of vinyl chloride (VC). The results of three consecutive runs and long-term tests showed high stability of the Ru/CoPO-MCF for the catalytic oxidation of VC. The unique heterostructures of the CoPO-MCF not only improve the reducibility and acidity of the MCF but also strengthen the interaction between ruthenium oxide nanoparticles and the CoPO-MCF support, which contributes to the enhanced catalytic performance.
ABSTRACT
As an attractive and environmentally friendly process for propylene oxide (PO) production, direct epoxidation of propylene (DEP) with molecular oxygen catalyzed by metal-based catalysts such as Ag and Cu has drawn much attention, but remains one of the biggest challenges in chemistry. In this work, the crucial competitive reactions of propylene α-H stripping (AHS) versus the oxametallacycle formation (OMMP formation) using adsorbed atomic oxygen (O*) or adsorbed molecular oxygen (O2*) as an oxidant are extensively compared on IB group metal surfaces (Cu, Ag and Au) with varied electronic and structural effects in order to explore the possibility to enhance the PO selectivity by virtue of first-principles calculations. The determining factor for the PO selectivity is quantitatively revealed: it is found that with atomic O*, the AHS pathway was preferred, indicating the reason for low PO selectivity with current catalysts. By contrast, the undissociated molecular O2* species is found to prefer to electrophilically attack the C[double bond, length as m-dash]C double bond of propylene and form a special oxametallacycle intermediate (OOMMP) rather than nucleophilically abstracting the α-H. This OOMMP can readily cleave the O-O bond and transform into OMMP. These results demonstrate that the presence of undissociated O2* can efficiently promote the PO selectivity. Furthermore, the merit of such a molecular O2* mechanism can be rationalized by our quantitative barrier decomposition analyses, which reveal that the lower hydrogen affinity (ΔEH) of the O2* species dominantly contributes to the limited AHS reaction, and boosts the OMMP selectivity. Therefore, ΔEH can be applied as a selectivity descriptor. An efficient strategy to promote PO formation is presented. The insight obtained could pave the way for further development of catalysts for propylene epoxidation.
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Controlling the physical and chemical properties of alloy nanoparticles (NPs) is an important approach to optimize NP catalysis. Unlike other tuning knobs, such as size, shape, and composition, crystal structure has received limited attention and not been well understood for its role in catalysis. This deficiency is mainly due to the difficulty in synthesis and fine-tuning of the NPs' crystal structure. Here, Exemplifying by AuCu alloy NPs with face centered cubic (fcc) and face centered tetragonal (fct) structure, we demonstrate a remarkable difference in phase segregation and catalytic performance depending on the crystal structure. During the thermal treatment in air, the Cu component in fcc-AuCu alloy NPs segregates more easily onto the alloy surface as compared to that in fct-AuCu alloy NPs. As a result, after annealing at 250 °C in air for 1 h, the fcc- and fct-AuCu alloy NPs are phase transferred into Au/CuO and AuCu/CuO core/shell structures, respectively. More importantly, this variation in heterostructures introduces a significant difference in CO adsorption on two catalysts, leading to a largely enhanced catalytic activity of AuCu/CuO NP catalyst for CO oxidation. The same concept can be extended to other alloy NPs, making it possible to fine-tune NP catalysis for many different chemical reactions.
ABSTRACT
The stabilization of surfactant-assisted synthesized colloidal noble metal nanoparticles (NPs, such as Auâ NPs) on solids is a promising strategy for preparing supported nanocatalysts for heterogeneous catalysis because of their uniform particle sizes, controllable shapes, and tunable compositions. However, surfactant removal to obtain clean surfaces for catalysis through traditional approaches (such as solvent extraction and thermal decomposition) can easily induce the sintering of NPs, greatly hampering their use in synthesis of novel catalysts. Such unwanted surfactants have now been utilized to stabilize NPs on solids by a simple yet efficient thermal annealing strategy. After being annealed in N2 flow, the surface-bound surfactants are carbonized inâ situ as sacrificial architectures that form a conformal coating on NPs and assist in creating an enhanced metal-support interaction between NPs and substrate, thus slowing down the Ostwald ripening process during post-oxidative calcination to remove surface covers.
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Supported gold (Au) nanocatalysts hold great promise for heterogeneous catalysis; however, their practical application is greatly hampered by poor thermodynamic stability. Herein, a general synthetic strategy is reported where discrete metal nanoparticles are made resistant to sintering, preserving their catalytic activities in high-temperature oxidation processes. Taking advantage of the unique coating chemistry of dopamine, sacrificial carbon layers are constructed on the material surface, stabilizing the supported catalyst. Upon annealing at high temperature under an inert atmosphere, the interactions between support and metal nanoparticle are dramatically enhanced, while the sacrificial carbon layers can be subsequently removed through oxidative calcination in air. Owing to the improved metal-support contact and strengthened electronic interactions, the resulting Au nanocatalysts are resistant to sintering and exhibit excellent durability for catalytic combustion of propylene at elevated temperatures. Moreover, the facile synthetic strategy can be extended to the stabilization of other supported catalysts on a broad range of supports, providing a general approach to enhancing the thermal stability and sintering resistance of supported nanocatalysts.
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Developing the high-efficient and green synthetic method for chiral amino alcohols is an intriguing target. We have developed the Mg(2+)-doped Cu/ZnO/Al2O3 catalyst for hydrogenation of L-phenylalanine methyl ester to chiral L-phenylalaninol without racemization. The effect of different L-phenylalanine esters on this title reaction was studied, verifying that Cu/ZnO/Al2O3 is an excellent catalyst for the hydrogenation of amino acid esters to chiral amino alcohols. DFT calculation was used to study the adsorption of substrate on the catalyst, and showed that the substrate adsorbs on the surface active sites mainly by amino group (-NH2) absorbed on Al2O3, and carbonyl (C=O) and alkoxy (RO-) group oxygen absorbed on the boundary of Cu and Al2O3. This catalytic hydrogenation undergoes the formation of a hemiacetal intermediate and the cleavage of the C-O bond (rate-determining step) by reacting with dissociated H to obtain amino aldehyde and methanol ad-species. The former is further hydrogenated to amino alcohols, and the latter desorbs from the catalyst surface.
Subject(s)
Aluminum Oxide/chemistry , Amino Acids/chemistry , Amino Alcohols/chemistry , Copper/chemistry , Zinc Oxide/chemistry , Adsorption , Amino Alcohols/chemical synthesis , Catalysis , Chemistry Techniques, Synthetic/methods , Esters/chemistry , Hydrogenation , Models, Chemical , Models, Molecular , Molecular Conformation , Molecular Structure , StereoisomerismABSTRACT
PdO/CeO2 nanosheets encapsulated by a monolayer of a continuous and dense HZSM-5 zeolite membrane were prepared by a facile in situ hydrothermal growth process and used as a highly efficient and thermally stable catalyst for methane combustion. Uncoated PdO/CeO2 suffered severe sintering at high temperature or high oxygen concentration. However, the encapsulation of HZSM-5 significantly improved sintering resistance by the suppressing effects of the HZSM-5 coating for the agglomeration of PdOx nanoparticles, resulting in the outstanding thermal stability of PdO/CeO2. Furthermore, the synthesized hybrid materials also exhibited good oxygen- and water-tolerance for methane combustion due to the oxygen or water barrier. In addition, a reactivation behavior was observed due to the self-redispersion of PdOx on CeO2 nanosheets in the reaction atmosphere at high temperature.
ABSTRACT
A simple, one-pot method to fabricate ordered, monodispersed Pd-CeO2 colloidal assembled spheres (CASs) was developed using the surfactant-mediated solvothermal approach, which involves a tunable self-assembled process by carefully controlling different chemical reactions. The evolution process and formation mechanism of the CASs were thoroughly investigated by time-controlled and component-controlled experiments. For CO oxidation, this CAS nanocatalyst exhibited much higher catalytic activity and thermal stability than Pd/CeO2 prepared by an impregnation method, and its complete CO conversion temperature is â¼120 °C. The enhanced catalytic performance for CO oxidation could be attributed to the synergistic effect of highly dispersed PdO species and Pd2+ ions incorporated into the CeO2 lattice. For this CAS catalyst, each sphere can be viewed as a single reactor, and its catalytic performance can be further improved after being supported on alumina, which is obviously higher than results previously reported. Furthermore, this method was used to successfully prepare M-CeO2 CASs (M = Pt, Cu, Mn, Co), showing further that this is a new and ideal approach for fabricating active and stable ceria-based materials.
ABSTRACT
Density functional theory (DFT+U) was used to study the adsorption of Aux (x = 1-4) clusters on the defective CeO2(111) facet and CO adsorption on the corresponding Aux/CeO2-x catalyst, in this work Aux clusters are adsorbed onto the CeO2-x + superoxide/peroxide surface. When Au1 is supported on the CeO2(111) facet with an O vacancy, the strong electronegative Au(δ-) formed is not favorable for CO adsorption. When peroxide is adsorbed on the CeO2(111) facet with the O vacancy, Aux was oxidized, resulting in stable Aux adsorption on the defective ceria surface with peroxide, which promotes CO adsorption on the Aux/CeO2-x catalyst. With more Au atoms in supported Aux clusters, CO adsorption on this surface becomes stronger. During both the Au being supported on CeO2-x and CO being adsorbed on Aux/CeO2-x, CeO2 acts as an electron buffer that can store/release the electrons. These results provide a scientific understanding for the development of high-performance rare earth catalytic materials.
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The novel catalysts xMg-2.3Cu/SBA-15 with copper and magnesium oxide co-supported on mesoporous silica were synthesized by an impregnation method. The newly synthesized catalysts were characterized using a series of techniques such as BET, XRD, H2-TPR, UV-vis, XPS, EDS and TEM. The catalytic performance was evaluated by using selective oxidation of cyclohexane with molecular oxygen as the oxidant in a solvent free system. The incorporation of magnesium improved the dispersion of copper oxide and prevented the deep oxidation of cyclohexanol and cyclohexanone. The selectivity of K/A oil was up to 99.3% with 12% conversion of cyclohexane over the 1.2Mg-2.3Cu/SBA-15 catalyst. To our knowledge, this is the best result for the heterogeneous oxidation of cyclohexane by O2.
ABSTRACT
A simple Pd-loaded Nb2 O5 /SiO2 catalyst was prepared for the hydrodeoxygenation of biomass-related compounds to alkanes under mild conditions. Niobium oxide dispersed in silica (Nb2 O5 /SiO2 ) as the support was prepared by the sol-gel method and characterized by various techniques, including N2 adsorption, XRD, NH3 temperature-programmed desorption (TPD), TEM, and energy-dispersive X-ray spectroscopy (EDAX) atomic mapping. The characterization results showed that the niobium oxide species were amorphous and well dispersed in silica. Compared to commercial Nb2 O5 , Nb2 O5 /SiO2 has significantly more active niobium oxide species exposed on the surface. Under mild conditions (170 °C, 2.5â MPa), Pd/10 %Nb2 O5 /SiO2 was effective for the hydrodeoxygenation reactions of 4-(2-furyl)-3-buten-2-one (aldol adduct of furfural with acetone), palmitic acid, tristearin, and diphenyl ether (model compounds of microalgae oils, vegetable oils, and lignin), which gave high yields (>94 %) of alkanes with little CC bond cleavage. More importantly, owing to the significant promotion effect of NbOx species on CO bond cleavage and the mild reaction conditions, the CC cleavage was considerably restrained, and the catalyst showed an excellent activity and stability for the hydrodeoxygenation of palmitic acid with almost no decrease in hexadecane yield (94-95 %) in a 150â h time-on-stream test.
Subject(s)
Alkanes/chemistry , Niobium/chemistry , Oxides/chemistry , Palladium/chemistry , Silicon Dioxide/chemistry , Biomass , Butanones/chemistry , Catalysis , Palmitic Acid/chemistry , Phenyl Ethers/chemistry , Triglycerides/chemistryABSTRACT
Diffusion processes and reactions of H at stoichiometric and reduced CeO2(111) surfaces have been studied by using density functional theory calculations corrected by on-site Coulomb interactions (DFT + U). Oxygen vacancies on the surface are determined to be able to significantly affect the behavior of H by modifying the charge of surface lattice O through the occurrence of Ce(3+). It has been found that, at the reduced CeO2(111) surface, the adsorption strength of H as well as the H coupling barrier can be dramatically reduced compared to those at the stoichiometric surface, while H2O formation barrier is not significantly affected. Moreover, the diffusion of H at the reduced surface or into the bulk can occur more readily than that at stoichiometric CeO2(111).
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A new strategy for the synthesis of epoxides is presented. This process allows the direct synthesis of epoxides from alkenes and aldehydes through C-H functionalization and C-C/C-O bond formation.
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NO adsorption, diffusion and reaction at reduced CeO2(110) were studied by density functional theory calculations. NO accommodated by O vacancies can readily diffuse via alternate NO2 formation and dissociation, facilitating N2O2 formation and subsequent reduction to N2. Rare earth ceria plays an important catalytic role in both static and dynamic ways by tuning the electron distribution in adsorbates and reacting molecules.