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1.
Nat Methods ; 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38744917

RESUMO

AlphaFold2 revolutionized structural biology with the ability to predict protein structures with exceptionally high accuracy. Its implementation, however, lacks the code and data required to train new models. These are necessary to (1) tackle new tasks, like protein-ligand complex structure prediction, (2) investigate the process by which the model learns and (3) assess the model's capacity to generalize to unseen regions of fold space. Here we report OpenFold, a fast, memory efficient and trainable implementation of AlphaFold2. We train OpenFold from scratch, matching the accuracy of AlphaFold2. Having established parity, we find that OpenFold is remarkably robust at generalizing even when the size and diversity of its training set is deliberately limited, including near-complete elisions of classes of secondary structure elements. By analyzing intermediate structures produced during training, we also gain insights into the hierarchical manner in which OpenFold learns to fold. In sum, our studies demonstrate the power and utility of OpenFold, which we believe will prove to be a crucial resource for the protein modeling community.

2.
Insect Mol Biol ; 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38613398

RESUMO

The silkworm (Bombyx mori) is an important model lepidopteran insect and can be used to identify pesticide resistance-related genes of great significance for biological control of pests. Uridine diphosphate glucosyltransferases (UGTs), found in all organisms, are the main secondary enzymes involved in the metabolism of heterologous substances. However, it remains uncertain if silkworm resistance to fenpropathrin involves UGT. This study observes significant variations in BmUGT expression among B. mori strains with variable fenpropathrin resistance post-feeding, indicating BmUGT's role in fenpropathrin detoxification. Knockdown of BmUGT with RNA interference and overexpression of BmUGT significantly decreased and increased BmN cell activity, respectively, indicating that BmUGT plays an important role in the resistance of silkworms to fenpropathrin. In addition, fenpropathrin residues were significantly reduced after incubation for 12 h with different concentrations of a recombinant BmUGT fusion protein. Finally, we verified the conservation of UGT to detoxify fenpropathrin in Spodoptera exigua: Its resistance to fenpropathrin decreased significantly after knocking down SeUGT. In a word, UGT plays an important role in silkworm resistance to fenpropathrin by directly degrading the compound, a function seen across other insects. The results of this study are of great significance for breeding silkworm varieties with high resistance and for biological control of pests.

3.
Phytomedicine ; 128: 155497, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38640855

RESUMO

BACKGROUND: Colorectal cancer (CRC) is a significant public health issue, ranking as one of the predominant cancer types globally in terms of incidence. Intriguingly, Arenobufagin (Are), a compound extracted from toad venom, has demonstrated the potential to inhibit tumor growth effectively. PURPOSE: This study aimed to explore Are's molecular targets and unravel its antitumor mechanism in CRC. Specifically, we were interested in its impact on immune checkpoint modulation and correlations with HSP90ß-STAT3-PD-L1 axis activity. METHODS: We investigated the in vivo antitumor effects of Are by constructing a colorectalcancer subcutaneous xenograft mouse model. Subsequently, we employed single-cell multi-omics technology to study the potential mechanism by which Are inhibits CRC. Utilizing target-responsive accessibility profiling (TRAP) technology, we identified heatshock protein 90ß (HSP90ß) as the direct target of Are, and confirmed this through a microscale thermophoresis experiment (MST). Further downstream mechanisms were explored through techniques such as co-immunoprecipitation, Western blotting, qPCR, and immunofluorescence. Concurrently, we arrived at the same research conclusion at the organoid level by co-cultivating with immune cells. RESULTS: We observed that Are inhibits PD-Ll expression in CRC tumor xenografts at low concentrations. Moreover, TRAP revealed that HSP90ß's accessibility significantly decreased upon Are binding. We demonstrated a decrease in the activity of the HSP90ß-STAT3-PD-Ll axis following low-concentration Are treatment in vivo. The PDO analysis showed improved enrichment of lymphocytes, particularly T cells, on the PDOs following Are treatment. CONCLUSION: Contrary to previous research focusing on the direct cytotoxicity of Are towards tumor cells, our findings indicate that it can also inhibit tumor growth at lower concentrations through the modulation of immune checkpoints. This study unveils a novel anti-tumor mechanism of Are and stimulates contemplation on the dose-response relationship of natural products, which is beneficial for the clinical translational application of Are.


Assuntos
Bufanolídeos , Neoplasias Colorretais , Proteínas de Choque Térmico HSP90 , Fator de Transcrição STAT3 , Ensaios Antitumorais Modelo de Xenoenxerto , Bufanolídeos/farmacologia , Animais , Neoplasias Colorretais/tratamento farmacológico , Humanos , Camundongos , Fator de Transcrição STAT3/metabolismo , Linfócitos T/efeitos dos fármacos , Linhagem Celular Tumoral , Antígeno B7-H1 , Camundongos Nus , Camundongos Endogâmicos BALB C , Venenos de Anfíbios/farmacologia , Feminino
4.
Front Surg ; 11: 1279194, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38601877

RESUMO

Purpose: We prospectively evaluate the short-term clinical and radiographic outcomes of the only Chinese domestically produced trabecular titanium acetabular cup(3D ACT™ cup) in primary total hip arthroplasty (THA), aiming to provide evidence-based support for its clinical application. Methods: A total of 236 patients, who underwent primary THA using 3D ACT™ cup in the Department of Joint Surgery at our hospital between January 2017 and June 2019, were included in this study. General patient data, imaging information, functional scores, and complications were collected to evaluate the early clinical efficacy. Results: All patients were followed up for 33-52 months, with an average of (42.2 ± 9.2) months. At the last follow-up, the preoperative HHS score increased significantly from 43.7 ± 6.8 to 85.6 ± 9.3 points (P < 0.01). Similarly, the preoperative WOMAC scores showed significant improvement from 59.2 ± 5.8 to 13.1 ± 3.5 points (P < 0.01). 92.3% of the patients expressed satisfaction or high satisfaction with the clinical outcome. Furthermore, 87.7% of the acetabular cups were positioned within the Lewinnek safe zone, achieving successful reconstruction of the acetabular rotation center. The cup survival rate at the last follow-up was 100%. Conclusions: The utilization of the only Chinese domestically manufactured 3D printing trabecular titanium acetabular cup in primary THA demonstrated favorable short-term clinical and radiographic outcomes. The acetabular cup exhibits excellent initial stability, high survival rate, and favorable osseointegration, leading to a significant enhancement in pain relief and functional improvement. In the future, larger sample sizes and multicenter prospective randomized controlled trials will be required to validate the long-term safety and effectiveness of this 3D ACT™ cup.

5.
Phytomedicine ; 125: 155290, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38308918

RESUMO

BACKGROUND: In our previous study, we provided evidence that Astragalus mongholicus Bunge(AM) and its extracts possess a protective capability against radiation-induced damage, potentially mediated through the reduction of reactive oxygen species (ROS) and nitric oxide (NO). However, we were pleasantly surprised to discover during our experimentation that AM not only offers protection against radiation damage but also exhibits a radiation sensitization effect. This effect may be attributed to a specific small molecule present in AM known as ononin. Currently, radiation sensitizers are predominantly found in nitrazole drugs and nanomaterials, with no existing reports on the radiation sensitization properties of ononin, nor its underlying mechanism. PURPOSE: This study aims to investigate the sensitization effect of the small molecule ononin derived from AM on lung cancer radiotherapy, elucidating its specific molecular mechanism of action. Additionally, the safety profile of combining astragalus small molecule ononin with radiation therapy will be evaluated. METHODS: The effective concentration of ononin was determined through cell survival experiments, and the impact of ononin combined with varying doses of radiation on lung cancer cells was observed using CCK-8 and cell cloning experiments. The apoptotic effect of ononin combined with radiation on lung cancer cells was assessed using Hochester staining, flow cytometry, and WB assay. Additionally, WB and immunofluorescence analysis were conducted to investigate the influence of ononin on HIF-1α/VEGF pathway. Furthermore, Molecular Dynamics Simulation was employed to validate the targeted binding ability of ononin and HIF-1α. A lung cancer cell line was established to investigate the effects of knockdown and overexpression of HIF-1α. Subsequently, the experiment was repeated using tumor bearing nude mice and C57BL/6 mouse models in an in vivo study. Tumor volume was measured using a vernier caliper, while HE, immunohistochemistry, and immunofluorescence techniques were employed to observe the effects of ononin combined with radiation on tumor morphology, proliferation, and apoptosis. Additionally, Immunofluorescence was employed to examine the impact of ononin on HIF-1α/VEGF pathway in vivo, and its effect on liver function in mice was assessed through biochemistry analysis. RESULTS: At a concentration of 25 µM, ononin did not affect the proliferation of lung epithelial cells but inhibited the survival of lung cancer cells. In vitro experiments demonstrated that the combination of ononin and radiation could effectively inhibit the growth of lung cancer cells, induce apoptosis, and suppress the excessive activation of the Hypoxia inducible factor 1 alpha/Vascular endothelial growth factor pathway. In vivo experiments showed that the combination of ononin and radiation reduced the size and proliferation of lung cancer tumors, promoted cancer cell apoptosis, mitigated abnormal activation of the Hypoxia inducible factor 1 alpha pathway, and protected against liver function damage. CONCLUSION: This study provides evidence that the combination of AM and its small molecule ononin can enhance the sensitivity of lung cancer to radiation. Additionally, it has been observed that this combination can specifically target HIF-1α and exert its effects. Notably, ononin exhibits the unique ability to protect liver function from damage while simultaneously enhancing the tumor-killing effects of radiation, thereby demonstrating a synergistic and detoxifying role in tumor radiotherapy. These findings contribute to the establishment of a solid basis for the development of novel radiation sensitizers derived from traditional Chinese medicine.


Assuntos
Glucosídeos , Isoflavonas , Neoplasias Pulmonares , Radiossensibilizantes , Camundongos , Animais , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/radioterapia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Camundongos Nus , Linhagem Celular Tumoral , Camundongos Endogâmicos C57BL , Fatores de Crescimento do Endotélio Vascular/metabolismo , Tolerância a Radiação , Radiossensibilizantes/farmacologia , Fator 1 Induzível por Hipóxia , Subunidade alfa do Fator 1 Induzível por Hipóxia
6.
J Pharm Biomed Anal ; 241: 115973, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38237547

RESUMO

The integrated analysis of host metabolome and intestinal microbiome is an opportunity to explore the complex therapeutic mechanisms of traditional Chinese medicines. Currently, researchers mainly employ various statistical correlation analytical methods to investigate metabolome-microbiome correlations. However, these conventional correlation techniques often focus on statistical correlations and their biological meanings are always ignored, especially the functional relevance between them. Here, we developed a novel enzyme-based functional correlation (EBFC) algorithm to further improve the interpretability and the identified scope of microbe-metabolite correlations based on the conventional Spearman's analysis. The proposed EBFC algorithm is successfully utilized to reveal the therapeutic mechanisms of Jian-Pi-Yi-Shen (JPYS) formula on the treatment of adenine-induced chronic kidney disease (CKD) rats. JPYS, a TCM formula for treating CKD, has beneficial clinical effects. We tentatively revealed the potential mechanism of JPYS for treating CKD rats from the perspective of the serum metabolome, gut microbiome, and their interactions. Specifically, 11 metabolites and 19 bacterial genera in the CKD rats were significantly regulated to approaching normal status after JPYS treatment, suggesting that JPYS could ameliorate the pathological symptoms of CKD rats by reshaping the disturbed metabolome and gut microbiota. Further correlation analysis between the significantly perturbed metabolites, microbiota, and the related enzymes provided more strong evidence for the study of host metabolism-microbiota interactions and the therapeutic mechanism of JPYS on CKD rats. In conclusion, these findings will help us to deeply understand the pathogenesis of CKD and provide new insights into the therapeutic mechanism of JPYS.


Assuntos
Medicamentos de Ervas Chinesas , Insuficiência Renal Crônica , Ratos , Animais , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/uso terapêutico , Multiômica , Medicina Tradicional Chinesa/métodos , Insuficiência Renal Crônica/metabolismo , Metaboloma
7.
Br J Surg ; 111(1)2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38215239

RESUMO

BACKGROUND: The aim of this multicentre cohort study was to compare the long-term oncological outcomes of robotic gastrectomy (RG) and laparoscopic gastrectomy (LG) for patients with gastric cancer. METHODS: Patients with gastric cancer who underwent radical gastrectomy by robotic or laparoscopic approaches from 1 March 2010 to 31 December 2018 at 10 high-volume centres in China were selected from institutional databases. Patients receiving RG were matched 1 : 1 by propensity score with patients undergoing LG. The primary outcome was 3-year disease-free survival. Secondary outcomes were overall survival and disease recurrence. RESULTS: Some 2055 patients who underwent RG and 4309 patients who had LG were included. The propensity score-matched cohort comprised 2026 RGs and 2026 LGs. Median follow-up was 41 (i.q.r. 39-58) months for the RG group and 39 (38-56) months for the LG group. The 3-year disease-free survival rates were 80.8% in the RG group and 79.5% in the LG group (log rank P = 0.240; HR 0.92, 95% c.i. 0.80 to 1.06; P = 0.242). Three-year OS rates were 83.9 and 81.8% respectively (log rank P = 0.068; HR 0.87, 0.75 to 1.01; P = 0.068) and the cumulative incidence of recurrence over 3 years was 19.3% versus 20.8% (HR 0.95, 0.88 to 1.03; P = 0.219), with no difference between groups. CONCLUSION: RG and LG in patients with gastric cancer are associated with comparable disease-free and overall survival.


Assuntos
Laparoscopia , Levamisol/análogos & derivados , Procedimentos Cirúrgicos Robóticos , Neoplasias Gástricas , Humanos , Resultado do Tratamento , Estudos de Coortes , Neoplasias Gástricas/cirurgia , Gastrectomia , Pontuação de Propensão , Estudos Retrospectivos , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/cirurgia
8.
J Sep Sci ; 47(1): e2300576, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38117985

RESUMO

The level of vitamin B group in human serum is an important index of human health. Among B vitamins, cyanocobalamin in serum is unstable and its content is extremely low. Rapid and simultaneous detection of multiple B vitamins including cyanocobalamin is a challenge. Herein, we have developed a rapid and stable method that can realize the determination of thiamine, riboflavin, nicotinamide, pantothenic acid, pyridoxic acid, biotin, 5-methyltetrahydrofolate, and cyanocobalamin simultaneously in 6 min. The method was established based on protein precipitation with methanol and then chromatographic separation was achieved using Waters acquity ultra-high-performance liquid chromatography high strength silica T3 column, which was stable and sensitive especially for cyanocobalamin. Limit of quantification, precision, trueness, and matrix effect were validated according to the European Medicines Agency and United States Food and Drug guidelines and Clinical and Laboratory Standards Institute guidelines on bioanalytical method. The limit of quantification for thiamine, riboflavin, nicotinamide, pantothenic acid, pyridoxic acid, biotin, 5-methyltetrahydrofolate, and cyanocobalamin was 0.4, 0.4, 0.8, 2.0, 0.4, 0.1, 0.4, and 0.04 ng/mL separately, respectively. Intra- and interday precisions were 1.1%-12.4% and 2.0%-13.5%, respectively. The relative errors were between 0.3% and 13.3%, and the matrix effects were between 2.6% and 10.4%.


Assuntos
Complexo Vitamínico B , Humanos , Ácido Pantotênico/análise , Biotina/análise , Espectrometria de Massas em Tandem/métodos , Ácido Piridóxico , Cromatografia Líquida/métodos , Tiamina/análise , Riboflavina/análise , Niacinamida/análise , Vitamina B 12/análise , Cromatografia Líquida de Alta Pressão/métodos , Vitamina A/análise , Vitamina K/análise
9.
Chem Commun (Camb) ; 60(5): 598-601, 2024 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-38099839

RESUMO

A new Cp*Rh(III)-catalyzed regioselective cyclization reaction of aromatic amides with allenes is reported. The use of allenyl derivatives bearing a directing-group assistant as a reaction promoter was the key to the success of this protocol. In this catalytic system, N-(pivaloyloxy)benzamide substrates react with allenes via Rh-σ-alkenyl intermediates, while N-(pivaloyloxy) indol substrates react via Rh-π-allyl intermediates. These reactions were characterized by mild reaction conditions, a broad substrate scope, and high functional-group compatibility to yield several high-value isoquinolinone and pyrimido[1,6-a]indol-1(2H)-one skeleton-containing compounds. The synthetic applications and primary mechanisms were also investigated.

10.
J Affect Disord ; 348: 167-174, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38154582

RESUMO

BACKGROUND AND AIMS: The comorbidity between bipolar disorder (BD) and inflammatory bowel disease (IBD) has been widely reported in observational studies. However, unclear whether this comorbidity reflects a shared genetic architecture. METHODS: Leveraging large-scale genome-wide association study (GWAS) summary statistics of BD, IBD and its subtypes, ulcerative colitis (UC) and Crohn's disease (CD), we performed a genome-wide pleiotropic analysis to estimate heritability and genetic correlation, identify pleiotropy loci/genes, and explore the shared biological pathway. Mendelian randomization (MR) studies were subsequently employed to infer whether the potential causal relationship is present. RESULTS: We found a positive significant genetic correlation between BD and IBD (rg = 0.10, P = 7.00 × 10-4), UC (rg = 0.09, P = 2.90 × 10-3), CD (rg = 0.08, P = 6.10 × 10-3). In cross-trait meta-analysis, a total of 29, 24, and 23 independent SNPs passed the threshold for significant association between BD and IBD, UC, and CD, respectively. We identified five novel pleiotropy genes including ZDHHC2, SCRN1, INPP4B, C1orf123, and BRD3 in both BD and IBD, as well as in its subtypes UC and CD. Pathway enrichment analyses revealed that those pleiotropy genes were mainly enriched in several immune-related signal transduction pathways and cerebral disease-related pathways. MR analyses provided no evidence for a causal relationship between BD and IBD. CONCLUSION: Our findings corroborated that shared genetic basis and common biological pathways may explain the comorbidity of BD and IBD. These findings further our understanding of shared genetic mechanisms underlying BD and IBD, and potentially provide points of intervention that may allow the development of new therapies for these co-occurrent disorders.


Assuntos
Transtorno Bipolar , Colite Ulcerativa , Doença de Crohn , Doenças Inflamatórias Intestinais , Humanos , Transtorno Bipolar/epidemiologia , Transtorno Bipolar/genética , Colite Ulcerativa/genética , Doença de Crohn/epidemiologia , Doença de Crohn/genética , Estudo de Associação Genômica Ampla , Doenças Inflamatórias Intestinais/genética , Análise da Randomização Mendeliana , Proteínas do Tecido Nervoso
11.
Nat Commun ; 14(1): 8346, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-38102124

RESUMO

The triangular lattice antiferromagnet (TLAF) has been the standard paradigm of frustrated magnetism for several decades. The most common magnetic ordering in insulating TLAFs is the 120° structure. However, a new triple-Q chiral ordering can emerge in metallic TLAFs, representing the short wavelength limit of magnetic skyrmion crystals. We report the metallic TLAF Co1/3TaS2 as the first example of tetrahedral triple-Q magnetic ordering with the associated topological Hall effect (non-zero σxy(H = 0)). We also present a theoretical framework that describes the emergence of this magnetic ground state, which is further supported by the electronic structure measured by angle-resolved photoemission spectroscopy. Additionally, our measurements of the inelastic neutron scattering cross section are consistent with the calculated dynamical structure factor of the tetrahedral triple-Q state.

12.
Sleep Med ; 112: 122-128, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37839273

RESUMO

BACKGROUND: Chronic insomnia disorder (CID) is frequently comorbid with depression, and both conditions are believed to involve disruptions in the reward network. However, the potential effects of genetic polymorphisms in modulating this network remain largely unexplored. METHODS: In this study, we recruited 50 CID patients with high (CID-HD) and low (CID-LD) depressive symptoms and assessed their reward networks using resting-state functional MRI. Additionally, we calculated the multilocus genetic profile score (MGPS) to examine the influence of depression and dopamine genetic variation on the nucleus accumbens functional connectivity (NAFC) network in CID patients. RESULTS: Although the MGPS did not show a significant difference between the two CID groups, its influence on the NAFC network was observed in the salience network (SN) and visual network (VN) in CID patients. When comparing CID-HD patients to CID-LD patients, we found that CID-HD patients exhibited decreased NAFC in the internal reward network, default mode network, SN, and sensorimotor network, while showing increased NAFC in the executive control network (ECN) and VN. Furthermore, the influence of MGPS on the reward network was only significant in CID-HD patients, specifically in the internal reward network and ECN. CONCLUSION: These findings suggest that genetic variations related to dopamine may modulate the reward network differently in CID patients with and without depressive symptoms. These results contribute to our understanding of the pathophysiology of polygenic effects underlying brain network abnormalities in CID patients with depression.


Assuntos
Depressão , Distúrbios do Início e da Manutenção do Sono , Humanos , Depressão/genética , Mapeamento Encefálico , Dopamina , Distúrbios do Início e da Manutenção do Sono/diagnóstico por imagem , Distúrbios do Início e da Manutenção do Sono/genética , Perfil Genético , Recompensa , Imageamento por Ressonância Magnética/métodos , Encéfalo
13.
Adv Exp Med Biol ; 1433: 113-137, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37751138

RESUMO

The histone lysine demethylase 5 (KDM5) family proteins are Fe2+ and α-ketoglutarate-dependent dioxygenases, with jumonji C (JmjC) domain as their catalytic core and several plant homeodomains (PHDs) to bind different histone methylation marks. These enzymes are capable of demethylating tri-, di- and mono-methylated lysine 4 in histone H3 (H3K4me3/2/1), the key epigenetic marks for active chromatin. Thus, this H3K4 demethylase family plays critical roles in cell fate determination during development as well as malignant transformation. KDM5 demethylases have both oncogenic and tumor suppressive functions in a cancer type-dependent manner. In solid tumors, KDM5A/B are generally oncogenic, whereas KDM5C/D have tumor suppressive roles. Their involvement in de-differentiation, cancer metastasis, drug resistance, and tumor immunoevasion indicated that KDM5 family proteins are promising drug targets for cancer therapy. Significant efforts from both academia and industry have led to the development of potent and selective KDM5 inhibitors for preclinical experiments and phase I clinical trials. However, a better understanding of the roles of KDM5 demethylases in different physiological and pathological conditions is critical for further developing KDM5 modulators for clinical applications.


Assuntos
Instituições de Assistência Ambulatorial , Lisina , Domínio Catalítico , Diferenciação Celular , Cromatina
14.
Phys Rev Lett ; 131(8): 086502, 2023 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-37683155

RESUMO

We analyze the validity of a quasiparticle description of a superconducting state above a metallic quantum-critical point (QCP). A normal state at a QCP is a non-Fermi liquid with no coherent quasiparticles. A superconducting order gaps out low-energy excitations, except for a sliver of states for non-s-wave gap symmetry, and at a first glance, restores coherent quasiparticle behavior. We argue that this does not necessarily hold as the fermionic self-energy may remain singular above the gap edge. This singularity gives rise to markedly non-BCS behavior of the density of states and to the appearance of a nondispersing mode at the gap edge in the spectral function. We analyze the set of quantum-critical models with an effective dynamical four-fermion interaction V(Ω)∝1/Ω^{γ}, where Ω is a frequency of a boson, which mediates the interaction. We show that coherent quasiparticle behavior in a superconducting state holds for γ<1/2, but breaks down for larger γ. We discuss signatures of quasiparticle breakdown and compare our results with the photoemission data for Bi2201 and Bi2212.

15.
Chempluschem ; 88(8): e202300287, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37528443

RESUMO

A white oil-in-water novel emulsion stabilized by TiO2 nanoparticles with UVB shielding properties and proanthocyanidins with antioxidant activity was prepared, where the proanthocyanidins aggregated at the oil-water interface to reduce interfacial tension while TiO2 nanoparticles were dispersed in the continuous water phase to hinder droplet coalescence. It was found that the average oil droplet size was less than 10 µm and decreased with the increase of proanthocyanidins concentration, but the increase of the content of TiO2 nanoparticles had little effect on it. The combination of TiO2 nanoparticles and proanthocyanidins was versatile for oil phases with different polarities, and the resulting emulsion exhibited high stability in the face of centrifugation, heating and prolonging storage time. After encapsulating the UVA filter avobenzone in white oil, the emulsion was endowed with the ability to resist UVB and UVA. Further, the emulsion showed great free radical scavenging ability for superoxide anion radical (⋅O2 - ), hydroxyl radical (⋅OH) with the clearance rate of over 70 %, indicating the good antioxidant activity. The ingenious combination of UVB, UVA filter and antioxidant with emulsion as carrier provides a new idea for the preparation of full-band sunscreen emulsion.

17.
Org Lett ; 25(28): 5179-5184, 2023 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-37415264

RESUMO

Rh (III)-catalyzed dienylation and cyclopropylation of 1,2,3-benzotriazinones with alkylidenecyclopropanes (ACPs) has been achieved. Different from the previous reports of 1,2,3-benzotriazinones, the triazinone ring remained intact in this C-H bond functionlization reaction. Also, the denitrogenative cyclopropylation could also be realized by changing the reaction temperature. This protocol is featured with high E selectivity, wide substrate scope, and divergent structures of products.

18.
Org Lett ; 25(28): 5185-5190, 2023 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-37439552

RESUMO

Cp*Rh(III)-catalyzed nitro-directed C-H alkylation/alkenylation of nitroarenes has been reported for the first time. This protocol is associated with the features of high efficiency, broad substrate scope, and good functional group compatibility. Additionally, gram-scale experiments and synthetic applications proved the practicability of the method. Moreover, preliminary mechanistic investigations consistently revealed C-H bond cleavage as the rate-limiting step.

19.
Nat Commun ; 14(1): 4199, 2023 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-37452016

RESUMO

The search for new elementary particles is one of the most basic pursuits in physics, spanning from subatomic physics to quantum materials. Magnons are the ubiquitous elementary quasiparticle to describe the excitations of fully-ordered magnetic systems. But other possibilities exist, including fractional and multipolar excitations. Here, we demonstrate that strong quantum interactions exist between three flavors of elementary quasiparticles in the uniaxial spin-one magnet FeI2. Using neutron scattering in an applied magnetic field, we observe spontaneous decay between conventional and heavy magnons and the recombination of these quasiparticles into a super-heavy bound-state. Akin to other contemporary problems in quantum materials, the microscopic origin for unusual physics in FeI2 is the quasi-flat nature of excitation bands and the presence of Kitaev anisotropic magnetic exchange interactions.


Assuntos
Campos Magnéticos , Imãs , Anisotropia , Nêutrons , Física
20.
Org Lett ; 25(23): 4286-4291, 2023 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-37265108

RESUMO

Two categories of tetrasubstituted phenols were prepared via the cycloaddition reaction of vinyl sulfoxonnium ylides with cyclopropenones in a switchable manner. Copper carbenoid was proposed as the active intermediate in the process of 2,3,4,5-tetrasubstituted phenols formation, while 2,3,5,6-tetrasubstituted phenols were generated via the direct [3 + 3] annulation of vinyl sulfoxonnium ylides with cyclopropenones under metal-free conditions. Further synthetic applications were also demonstrated.


Assuntos
Cobre , Metais , Catálise , Reação de Cicloadição
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