Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.076
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Proc Natl Acad Sci U S A ; 121(30): e2401091121, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39024109

RESUMO

Achieving ligand subtype selectivity within highly homologous subtypes of G-protein-coupled receptor (GPCR) is critical yet challenging for GPCR drug discovery, primarily due to the unclear mechanism underlying ligand subtype selectivity, which hampers the rational design of subtype-selective ligands. Herein, we disclose an unusual molecular mechanism of entropy-driven ligand recognition in cannabinoid (CB) receptor subtypes, revealed through atomic-level molecular dynamics simulations, cryoelectron microscopy structure, and mutagenesis experiments. This mechanism is attributed to the distinct conformational dynamics of the receptor's orthosteric pocket, leading to variations in ligand binding entropy and consequently, differential binding affinities, which culminate in specific ligand recognition. We experimentally validated this mechanism and leveraged it to design ligands with enhanced or ablated subtype selectivity. One such ligand demonstrated favorable pharmacokinetic properties and significant efficacy in rodent inflammatory analgesic models. More importantly, it is precisely due to the high subtype selectivity obtained based on this mechanism that this ligand does not show addictive properties in animal models. Our findings elucidate the unconventional role of entropy in CB receptor subtype selectivity and suggest a strategy for rational design of ligands to achieve entropy-driven subtype selectivity for many pharmaceutically important GPCRs.


Assuntos
Entropia , Simulação de Dinâmica Molecular , Receptores Acoplados a Proteínas G , Ligantes , Animais , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/química , Humanos , Ligação Proteica , Camundongos , Microscopia Crioeletrônica , Receptores de Canabinoides/metabolismo , Receptores de Canabinoides/química , Sítios de Ligação
2.
Acc Chem Res ; 57(20): 2973-2984, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-39370784

RESUMO

ConspectusPorous metal phosphonate frameworks (PMPFs) as a subclass of metal-organic frameworks (MOFs) have promising applications in the fields of gas adsorption and separation, ion exchange and storage, catalysis, sensing, etc. Compared to the typical carboxylate-based MOFs, PMPFs exhibit higher thermal and water stability due to the strong coordination ability of the phosphonate ligands. Despite their robust frameworks, PMPFs account for less than 0.51% of the porous MOFs reported so far. This is because metal phosphonates are highly susceptible to the formation of dense layered or pillared-layered structures, and they precipitate easily and are difficult to crystallize. There is a tendency to use phosphonate ligands containing multiple phosphonate groups and large organic spacers to prevent the formation of dense structures and generate open frameworks with permanent porosity. Thus, many PMPFs are composed of chains or clusters of inorganic metal phosphonates interconnected by organic spacers. Using this feature, a wide range of metal ions and organic components can be selected, and their physical properties can be modulated. However, limited by the small number of PMPFs, there are still relatively few studies on the physical properties of PMPFs, some of which merely remain in the description of the phenomena and lack in-depth elaboration of the structure-property relationship. In this Account, we review the strategies for constructing PMPFs and their physical properties, primarily based on our own research. The construction strategies are categorized according to the number (n = 1-4) of phosphonate groups in the ligand. The physical properties include proton conduction, electrical conduction, magnetism, and photoluminescence properties. Proton conductivity of PMPFs can be enhanced by increasing the proton carrier concentration and mobility. The former can be achieved by adding acidic groups such as -POH and/or introducing acidic guests in the hydrophilic channels. The latter can be attained by introducing conjugate acid-base pairs or elevating the temperature. Semiconducting PMPFs, on the other hand, can be obtained by constructing highly conjugated networks of coordination bonds or introducing large conjugated organic linkers π-π stacked in the lattice. In the case of magnetic PMPFs, long-range magnetic ordering occurs at very low temperatures due to very weak magnetic exchange couplings propagated via O-P-O and/or O(P) units. However, lanthanide compounds may be interesting candidates for single-molecule magnets because of the strong single-ion magnetic anisotropy arising from the spin-orbit coupling and large magnetic moments of lanthanide ions. The luminescent properties of PMPFs depend on the metal ions and/or organic ligands. Emissive PMPFs containing lanthanides and/or uranyl ions are promising for sensing and photonic applications. We conclude with an outlook on the opportunities and challenges for the future development of this promising field.

3.
Cereb Cortex ; 34(9)2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39264754

RESUMO

Inflammation may be related to structural changes in the cerebral cortex. We aimed to explore whether cytokines mediate the link between these changes and primary headache. The summary statistics of genome-wide association study (GWAS) related to migraine and its subtypes, cluster headache were derived from the FinnGen Release 10 database, and tension-type headache data was from the GWAS Catalog. Ninety-one cytokines were obtained from genome-wide pQTL mapping data. GWAS data on cortical surface area (SA) and thickness (TH) came from the ENIGMA Consortium. The methods of Mendelian randomization (MR) analysis included the inverse-variance-weighted (IVW), MR-Egger, and weighted median. Migraine reduces the SA of paracentral[ß = -1.3645, OR = 0.2555, 95%CI (0.0660, 0.9898)] by fibroblast growth factor-23(FGF-23), with an intermediate ratio (IR) of 38.13%. Migraine may reduce the TH of superior parietal[ß = -0.0029, OR = 0.9971, 95%CI (0.9943, 0.9999)] by interleukin (IL)-15RA, with an absolute IR of 11.11%. Migraine without aura may reduce the TH of rostral anterior cingulate[ß = -0.0005, OR = 0.9995, 95%CI (0.9991, 0.9999)] by IL-18R1, with an IR of 11.63%. FGF23 and IL-15RA are associated with reduced SA or TH in migraine, while IL-18R1 is associated with increased TH in migraine without aura.


Assuntos
Córtex Cerebral , Citocinas , Estudo de Associação Genômica Ampla , Análise da Randomização Mendeliana , Humanos , Córtex Cerebral/patologia , Córtex Cerebral/diagnóstico por imagem , Citocinas/sangue , Citocinas/genética , Citocinas/metabolismo , Transtornos de Enxaqueca/genética , Transtornos de Enxaqueca/sangue , Transtornos de Enxaqueca/patologia
4.
Nano Lett ; 24(17): 5132-5138, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38588326

RESUMO

Nanoparticle synthesis on microfluidic platforms provides excellent reproducibility and control over bulk synthesis. While there have been plenty of platforms for producing nanoparticles (NPs) with controlled physicochemical properties, such platforms often operate in a narrow range of predefined flow rates. The flow rate limitation restricts either up-scalability for industrial production or down-scalability for exploratory research use. Here, we present a universal flow rate platform that operates over a wide range of flow rates (0.1-75 mL/min) for small-scale exploratory research and industrial-level synthesis of NPs without compromising the mixing capabilities. The wide range of flow rate is obtained by using a coaxial flow with a triangular microstructure to create a vortex regardless of the flow regime (Reynolds number). The chip synthesizes several types of NPs for gene and protein delivery, including polyplex, lipid NPs, and solid polymer NPs via self-assembly and precipitation, and successfully expresses GFP plasmid DNA in human T cells.


Assuntos
Nanopartículas , Nanopartículas/química , Humanos , Técnicas Analíticas Microfluídicas , Microfluídica/métodos , Linfócitos T/citologia , Polímeros/química , DNA/química
5.
Nano Lett ; 24(39): 12254-12262, 2024 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-39302875

RESUMO

Transition metal phosphide nanoparticles (TMP NPs) represent a promising class of nanomaterials in the field of energy; however, a universal, time-saving, energy-efficient, and scalable synthesis method is currently lacking. Here, a facile synthesis approach is first introduced using a pulsed laser shock (PLS) process mediated by metal-organic frameworks, free of any inert gas protection, enabling the synthesis of diverse TMP NPs. Additionally, through thermodynamic calculations and experimental validation, the phase selection and competition behavior between phosphorus and oxygen have been elucidated, dictated by the redox potential and electronegativity. The resulting composites exhibit a balanced performance and extended durability. When employed as electrocatalysts for overall water splitting, the as-constructed electrolyzer achieves a low cell voltage of 1.54 V at a current density of 10 mA cm-2. This laser method for phosphide synthesis provides clear guidelines and holds potential for the preparation of nanomaterials applicable in catalysis, energy storage, biosensors, and other fields.

6.
Immunology ; 172(2): 235-251, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38425094

RESUMO

Myocarditis has emerged as a rare but lethal immune checkpoint inhibitor (ICI)-associated toxicity. However, the exact mechanism and the specific therapeutic targets remain underexplored. In this study, we aim to characterise the transcriptomic profiles based on single-cell RNA sequencing from ICI-related myocarditis. Peripheral blood mononuclear cell (PBMC) samples were collected from four groups for single-cell RNA sequencing: (1) patients with newly diagnosed lung squamous cell carcinoma before treatment (Control Group); (2) patients with lung squamous cell carcinoma with PD-1 inhibitor therapy who did not develop myocarditis (PD-1 Group); (3) patients during fulminant ICI-related myocarditis onset (Myocarditis Group); and (4) Patients with fulminant ICI-related myocarditis during disease remission (Recovery Group). Subcluster determination, functional analysis, single-cell trajectory and cell-cell interaction analysis were performed after scRNA-seq. Bulk-RNA sequencing was performed for further validation. Our results revealed the diversity of cellular populations in ICI-related myocarditis, marked by their distinct transcriptional profiles and biological functions. Monocytes, NKs as well as B cells contribute to the regulation of innate immunity and inflammation in ICI-related myocarditis. With integrated analysis of scRNA-seq and bulk sequencing, we identified S100A protein family as a potential serum marker for ICI-related myocarditis. Our study has created a cell atlas of PBMC during ICI-related myocarditis, which would shed light on the pathophysiological mechanism and potential therapeutic targets of ICI-related myocarditis in continuous exploration.


Assuntos
Inibidores de Checkpoint Imunológico , Imunidade Inata , Neoplasias Pulmonares , Miocardite , Análise de Célula Única , Humanos , Miocardite/imunologia , Miocardite/induzido quimicamente , Miocardite/genética , Inibidores de Checkpoint Imunológico/efeitos adversos , Inibidores de Checkpoint Imunológico/uso terapêutico , Masculino , Feminino , Pessoa de Meia-Idade , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/genética , Transcriptoma , Análise de Sequência de RNA , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Idoso , Carcinoma de Células Escamosas/imunologia , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/genética , Perfilação da Expressão Gênica
7.
J Am Chem Soc ; 146(27): 18407-18417, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38935530

RESUMO

High-entropy alloy nanoparticles (HEA-NPs) show exceptional properties and great potential as a new generation of functional materials, yet a universal and facile synthetic strategy in air toward nonoxidized and precisely controlled composition remains a huge challenge. Here we provide a laser scribing method to prepare single-phase solid solution HEA-NPs libraries in air with tunable composition at the atomic level, taking advantage of the laser-induced metastable thermodynamics and substrate-assisted confinement effect. The three-dimensional porous graphene substrate functions as a microreactor during the fast heating/cooling process, which is conductive to the generation of the pure alloy phase by effectively blocking the binding of oxygen and metals, but is also beneficial for realizing accurate composition control via microstructure confinement-endowed favorable vapor pressure. Furthermore, by combining an active learning approach based on an adaptive design strategy, we discover an optimal composition of quinary HEA-NP catalysts with an ultralow overpotential for Li-CO2 batteries. This method provides a simple, fast, and universal in-air route toward the controllable synthesis of HEA-NPs, potentially integrated with machine learning to accelerate the research on HEAs.

8.
Am J Epidemiol ; 193(3): 479-488, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-37968336

RESUMO

Maternal poor sleep quality may increase blood pressure during pregnancy, but sound evidence is still limited and inconsistent. To evaluate whether sleep disturbances in early gestation are risk factors for the development of hypertensive disorders of pregnancy, we conducted the Early Life Plan Project from June 2016 to December 2019. Maternal sleep patterns were assessed at 12-16 weeks of gestation by using the Pittsburgh Sleep Quality Index questionnaire. For gestational hypertension and preeclampsia, we estimated adjusted odds ratios (ORs) and 95% confidence intervals (CIs) using multinomial logistic regression models adjusting for potential confounders. Among 5,532 eligible women, we observed that maternal blood pressure in early gestation was significantly higher in women with low sleep efficiency (≤85%), long sleep duration (≥9 hours/night), and snoring. Compared with nonsnorers, snoring in early gestation was independently associated with preeclampsia (OR = 1.72 (95% CI: 1.09, 2.73) for snoring once or twice per week; OR = 2.06 (95% CI: 1.01, 4.31) for snoring 3 or more times per week), particularly for term preeclampsia (OR = 1.79 (95% CI: 1.08, 2.95) and 2.26 (95% CI: 1.03, 4.95), respectively). Results suggest that snoring in early gestation may be a significant risk factor for preeclampsia, with a dose-response pattern.


Assuntos
Hipertensão Induzida pela Gravidez , Pré-Eclâmpsia , Transtornos do Sono-Vigília , Gravidez , Feminino , Humanos , Hipertensão Induzida pela Gravidez/epidemiologia , Pré-Eclâmpsia/epidemiologia , Pré-Eclâmpsia/etiologia , Ronco/complicações , Ronco/epidemiologia , Estudos Prospectivos , Transtornos do Sono-Vigília/complicações , Transtornos do Sono-Vigília/epidemiologia , Sono
9.
BMC Plant Biol ; 24(1): 19, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38166635

RESUMO

BACKGROUND: Camellia olelfera petals are colorful, and have high ornamental value. However, the color formation mechanism of C. olelfera petals with different color is still unclear. In our study, WGCNA method was applied to integrate metabolites and transcriptomes to investigate the coloration mechanism of four C. olelfera cultivars with different petal colors. RESULTS: Here, a total of 372 flavonoids were identified (including 27 anthocyanins), and 13 anthocyanins were significantly differentially accumulated in C. olelfera petals. Among them, cyanidin-3-O-(6''-O-p-Coumaroyl) glucoside was the main color constituent in pink petals, cyanidin-3-O-glucoside, cyanidin-3-O-galactoside, cyanidin-3-O-rutinoside, and cyanidin-3-O-(6''-O-malonyl) glucoside were the main contributors to candy pink petals, and peonidin-3-O-glucoside was the important color substance responsible for the red petals of C. oleifera. Furthermore, six structural genes (Co4CL1, CoF3H1, CoF3'H, CoANS, CoUGT75C1-4, and CoUGT75C1-5), three MYBs (CoMYB1, CoMYB4, and CoMYB44-3), three bHLHs (CobHLH30, CobHLH 77, and CobHLH 79-1), and two WRKYs (CoWRKY7 and CoWRKY22) could be identified candidate genes related to anthocyanins biosynthesis and accumulation, and lead to the pink and red phenotypes. The regulatory network of differentially accumulated anthocyanins and the anthocyanins related genes in C. olelfera petals were established. CONCLUSIONS: These findings elucidate the molecular basis of the coloration mechanisms of pink and red color in C. olelfera petals, and provided valuable target genes for future improvement of petals color in C. olelfera.


Assuntos
Antocianinas , Camellia , Antocianinas/metabolismo , Camellia/genética , Camellia/metabolismo , Flores/metabolismo , Perfilação da Expressão Gênica , Transcriptoma , Metaboloma , Glucosídeos/metabolismo , Cor
10.
BMC Med ; 22(1): 317, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39113030

RESUMO

BACKGROUND: The non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR) serves as a novel composite lipid indicator for atherosclerosis. However, the association between NHHR and mortality in patients with diabetes or prediabetes remains unclear. Consequently, the objective of this study was to investigate the relationship between NHHR and both all-cause and cardiovascular mortality in US adults with diabetes or prediabetes. METHODS: This study included 12,578 adult participants with diabetes or prediabetes from the US National Health and Nutrition Examination Survey (1999-2018). Mortality outcomes were ascertained by linking to the National Death Index (NDI) record up to December 31, 2019. We employed a weighted multivariate Cox proportional hazards model and restricted cubic splines to assess the associations between NHHR and all-cause and cardiovascular mortality. A segmented Cox proportional hazards model was used for evaluating threshold effects. Furthermore, a competing risks analysis was performed to explore the relationship between NHHR and cardiovascular mortality. RESULTS: During a median follow-up period of 8.08 years, 2403 participants encountered all-cause mortality, with 662 of them specifically succumbing to cardiovascular mortality. The restricted cubic splines revealed a U-shaped association between NHHR and all-cause mortality, while an L-shaped association was observed for cardiovascular mortality. The analysis of threshold effects revealed that the inflection points for NHHR and all-cause and cardiovascular mortality were 2.72 and 2.83, respectively. Specifically, when the baseline NHHR was below the inflection points, a negative correlation was observed between NHHR and both all-cause mortality (HR: 0.76, 95% CI: 0.68-0.85) and cardiovascular mortality (HR: 0.70, 95% CI: 0.57-0.85). Conversely, when the baseline NHHR exceeded the inflection points, a positive correlation was observed between NHHR and both all-cause mortality (HR: 1.11, 95% CI: 1.06-1.16) and cardiovascular mortality (HR: 1.08, 95% CI: 1.00-1.16). CONCLUSIONS: Among US adults with diabetes or prediabetes, a U-shaped association was observed between NHHR and all-cause mortality, whereas an L-shaped association was identified with cardiovascular mortality. The inflection points for all-cause and cardiovascular mortality were 2.72 and 2.83, respectively.


Assuntos
Doenças Cardiovasculares , Diabetes Mellitus , Inquéritos Nutricionais , Estado Pré-Diabético , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Estado Pré-Diabético/sangue , Estado Pré-Diabético/mortalidade , Doenças Cardiovasculares/mortalidade , Doenças Cardiovasculares/sangue , Adulto , Estados Unidos/epidemiologia , Diabetes Mellitus/mortalidade , Diabetes Mellitus/sangue , HDL-Colesterol/sangue , Idoso , Modelos de Riscos Proporcionais , Causas de Morte
11.
BMC Med ; 22(1): 105, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38454462

RESUMO

BACKGROUND: The relaxation of the "zero-COVID" policy on Dec. 7, 2022, in China posed a major public health threat recently. Complete blood count test was discovered to have complicated relationships with COVID-19 after the infection, while very few studies could track long-term monitoring of the health status and identify the characterization of hematological parameters prior to COVID-19. METHODS: Based on a 13-year longitudinal prospective health checkup cohort of ~ 480,000 participants in West China Hospital, the largest medical center in western China, we documented 998 participants with a laboratory-confirmed diagnosis of COVID-19 during the 1 month after the policy. We performed a time-to-event analysis to explore the associations of severe COVID-19 patients diagnosed, with 34 different hematological parameters at the baseline level prior to COVID-19, including the whole and the subtypes of white and red blood cells. RESULTS: A total of 998 participants with a positive SARS-CoV-2 test were documented in the cohort, 42 of which were severe cases. For white blood cell-related parameters, a higher level of basophil percentage (HR = 6.164, 95% CI = 2.066-18.393, P = 0.001) and monocyte percentage (HR = 1.283, 95% CI = 1.046-1.573, P = 0.017) were found associated with the severe COVID-19. For lymphocyte-related parameters, a lower level of lymphocyte count (HR = 0.571, 95% CI = 0.341-0.955, P = 0.033), and a higher CD4/CD8 ratio (HR = 2.473, 95% CI = 1.009-6.059, P = 0.048) were found related to the risk of severe COVID-19. We also observed that abnormality of red cell distribution width (RDW), mean corpuscular hemoglobin concentration (MCHC), and hemoglobin might also be involved in the development of severe COVID-19. The different trajectory patterns of RDW-SD and white blood cell count, including lymphocyte and neutrophil, prior to the infection were also discovered to have significant associations with the risk of severe COVID-19 (all P < 0.05). CONCLUSIONS: Our findings might help decision-makers and clinicians to classify different risk groups of population due to outbreaks including COVID-19. They could not only optimize the allocation of medical resources, but also help them be more proactive instead of reactive to long COVID-19 or even other outbreaks in the future.


Assuntos
COVID-19 , Humanos , COVID-19/diagnóstico , COVID-19/epidemiologia , SARS-CoV-2 , Estudos Longitudinais , Seguimentos , Síndrome de COVID-19 Pós-Aguda , Estudos Retrospectivos
12.
Small ; 20(32): e2311606, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38497093

RESUMO

Novel 2D materials with low-symmetry structures exhibit great potential applications in developing monolithic polarization-sensitive photodetectors with small volume. However, owing to the fact that at least half of them presented a small anisotropic factor of ≈2, comprehensive performance of present polarization-sensitive photodetectors based on 2D materials is still lower than the practical application requirements. Herein, a self-driven photodetector with high polarization sensitivity using a broken-gap ReSe2/SnSe2 van der Waals heterojunction (vdWH) is demonstrated. Anisotropic ratio of the photocurrent (Imax/Imin) could reach 12.26 (635 nm, 179 mW cm-2). Furthermore, after a facile combination of the ReSe2/SnSe2 device with multilayer graphene (MLG), Imax/Imin of the MLG/ReSe2/SnSe2 can be further increased up to13.27, which is 4 times more than that of pristine ReSe2 photodetector (3.1) and other 2D material photodetectors even at a bias voltage. Additionally, benefitting from the synergistic effect of unilateral depletion and photoinduced tunneling mechanism, the MLG/ReSe2/SnSe2 device exhibits a fast response speed (752/928 µs) and an ultrahigh light on/off ratio (105). More importantly, MLG/ReSe2/SnSe2 device exhibits excellent potential applications in polarized imaging and polarization-coded optical communication with quaternary logic state without any power supply. This work provides a novel feasible avenue for constructing next-generation smart polarization-sensitive photodetector with low energy consumption.

13.
BMC Neurosci ; 25(1): 8, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38350864

RESUMO

Traumatic brain injury (TBI) is one of the leading causes of death and disability worldwide, and destruction of the cerebrovascular system is a major factor in the cascade of secondary injuries caused by TBI. Laser speckle imaging (LSCI)has high sensitivity in detecting cerebral blood flow. LSCI can visually show that transcranial focused ultrasound stimulation (tFUS) treatment stimulates angiogenesis and increases blood flow. To study the effect of tFUS on promoting angiogenesis in Controlled Cortical impact (CCI) model. tFUS was administered daily for 10 min and for 14 consecutive days after TBI. Cerebral blood flow was measured by LSCI at 1, 3, 7 and 14 days after trauma. Functional outcomes were assessed using LSCI and neurological severity score (NSS). After the last test, Nissl staining and vascular endothelial growth factor (VEGF) were used to assess neuropathology. TBI can cause the destruction of cerebrovascular system. Blood flow was significantly increased in TBI treated with tFUS. LSCI, behavioral and histological findings suggest that tFUS treatment can promote angiogenesis after TBI.


Assuntos
Lesões Encefálicas Traumáticas , Fator A de Crescimento do Endotélio Vascular , Camundongos , Animais , Lesões Encefálicas Traumáticas/diagnóstico por imagem , Lesões Encefálicas Traumáticas/terapia , Lesões Encefálicas Traumáticas/patologia , Circulação Cerebrovascular/fisiologia
14.
Chemistry ; 30(6): e202303193, 2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-37943119

RESUMO

Cyclic azobenzene-BODIPY hybrids were synthesized via cyclization by 1) acid-catalysed condensation of azobenzene-bridged dipyrroles with 3,5-di-tert-butylbenzaldehyde, 2) oxidation with DDQ, and 3) metalation with BF3 ⋅ Et2 O. The structures of many cyclic hybrids have been confirmed by single crystal X-ray analysis. The absorption spectra of the hybrids reveal the effective cyclic conjugation. The ultrafast measurements reveal that the photoexcited decays of these cyclic hybrids depend upon the ring size and connectivity.

15.
Chemphyschem ; : e202400757, 2024 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-39363706

RESUMO

Intermolecular interactions and adsorbate coverage on a metal electrode's surface/interface play an important role in CO2 reduction reaction (CO2RR). Herein, the activity and selectivity of CO2RR on bimetallic electrode, where a full monoatomic Cu layer covers on Ag surface (CuML/Ag) are investigated by using density functional theory calculations. The surface geometric and electronic structure results indicate that there is high electrocatalytic activity for CO2RR on the CuML/Ag electrode. Specifically, the CuML/Ag surface can accelerate the H2O and CO2 adsorption and hydrogenation while lowering the reaction energy of the rate-determining step. The structure parameters of chemisorbed CO2 with and without H2O demonstrate that activated H2O not only promotes the C-O dissociation but also provides the protons required for CO2RR on the CuML/Ag electrode surface. Furthermore, the various reaction mechanism diagrams indicate that the CuML/Ag electrode has high selectivity for CO2RR, and the efficiency of products can be regulated by modulating the reaction's electric potential.

16.
Eur Radiol ; 34(10): 6667-6679, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38627290

RESUMO

OBJECTIVES: To build self-supervised foundation models for multicontrast MRI of the whole brain and evaluate their efficacy in assisting diagnosis of brain tumors. METHODS: In this retrospective study, foundation models were developed using 57,621 enhanced head MRI scans through self-supervised learning with a pretext task of cross-contrast context restoration with two different content dropout schemes. Downstream classifiers were constructed based on the pretrained foundation models and fine-tuned for brain tumor detection, discrimination, and molecular status prediction. Metrics including accuracy, sensitivity, specificity, and area under the ROC curve (AUC) were used to evaluate the performance. Convolutional neural networks trained exclusively on downstream task data were employed for comparative analysis. RESULTS: The pretrained foundation models demonstrated their ability to extract effective representations from multicontrast whole-brain volumes. The best classifiers, endowed with pretrained weights, showed remarkable performance with accuracies of 94.9, 92.3, and 80.4%, and corresponding AUC values of 0.981, 0.972, and 0.852 on independent test datasets in brain tumor detection, discrimination, and molecular status prediction, respectively. The classifiers with pretrained weights outperformed the convolutional classifiers trained from scratch by approximately 10% in terms of accuracy and AUC across all tasks. The saliency regions in the correctly predicted cases are mainly clustered around the tumors. Classifiers derived from the two dropout schemes differed significantly only in the detection of brain tumors. CONCLUSIONS: Foundation models obtained from self-supervised learning have demonstrated encouraging potential for scalability and interpretability in downstream brain tumor-related tasks and hold promise for extension to neurological diseases with diffusely distributed lesions. CLINICAL RELEVANCE STATEMENT: The application of our proposed method to the prediction of key molecular status in gliomas is expected to improve treatment planning and patient outcomes. Additionally, the foundation model we developed could serve as a cornerstone for advancing AI applications in the diagnosis of brain-related diseases.


Assuntos
Neoplasias Encefálicas , Imageamento por Ressonância Magnética , Humanos , Neoplasias Encefálicas/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Projetos Piloto , Estudos Retrospectivos , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Interpretação de Imagem Assistida por Computador/métodos , Sensibilidade e Especificidade , Redes Neurais de Computação , Idoso
17.
Soft Matter ; 20(3): 463-483, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38167904

RESUMO

As a special type of branched polymers, comb-like polymers simultaneously possess the structural characteristics of a linear backbone profile and crowded sidechain branches/grafts, and such structural uniqueness leads to reduced interchain entanglement, enhanced molecular orientation, and unique stimulus-response behavior, which greatly expands the potential applications in the fields of super-soft elastomers, molecular sensors, lubricants, photonic crystals, etc. In principle, all these molecular features can be traced back to three structural parameters, i.e., the degree of polymerization of the backbone (Nb), the degree of polymerization of the graft sidechain (Ng), and the grafting density (σ). Consequently, it is of great importance to understand the correlation mechanism between the structural characteristics and physicochemical properties, among which, the conformational properties in dilute solution have received the most attention due to its central position in polymer science. In the past decades, the development of synthetic chemistry and characterization techniques has greatly stimulated the progress of this field, and a number of experiments have been executed to verify the conformational properties; however, due to the complexity of the structural parameters and the diversity of the chemical design, the achieved experimental progress displays significant controversies compared with the theoretical predictions. This review aims to provide a full picture of recent research progress on this topic, specifically, (1) first, a few classical theoretical models regarding the chain conformation are introduced, and the quasi-two-parameter (QTP) theory for the conformation analysis is highlighted; (2) second, the research progress of the static conformation of comb-like polymers in dilute solution is discussed; (3) third, the research progress of the dynamic conformation in dilute solution is further discussed. The key issues, existing controversies and future research directions are also highlighted. We hope that this review can provide insightful information for the understanding of the conformational properties of comb-like polymers, open a new door for the regulation of conformational behavior in related applications, and promote related theoretical and experimental research in the community.

18.
BMC Gastroenterol ; 24(1): 312, 2024 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-39285342

RESUMO

INTRODUCTION: In December 2019, COVID-19 emerged in Wuhan, Hubei Province, China, and rapidly spread worldwide. On December 2022, the Chinese government ended the zero-COVID policy, leading to a surge in cases and significantly impacting daily life. IBD patients face heightened infection risks and substantial effects on their quality of life during the pandemic. METHODS: This cross-sectional study collected demographic, COVID-19-related, and HRQoL data from 224 IBD patients who had previously received treatment at Nanjing BenQ Medical Center. Participants completed an online survey between January 9, 2023, and January 23, 2023. The SIBDQ was used to assess HRQoL. Statistical analysis was performed using SPSS version 26. RESULTS: The study found that UC patients reported higher HRQoL compared to CD patients (p = 0.037). Patients who perceived themselves as less susceptible to COVID-19 had higher scores (p = 0.006 and p = 0.009). Those whose work or study was unaffected also had higher scores (p < 0.001 and p = 0.002). Additionally, irregular medication adherence was associated with lower HRQoL scores (p = 0.014 and p = 0.007). Multivariate linear regression results showed that IBD patients whose work or study was affected during the COVID-19 pandemic scored lower than those who were not affected (p = 0.038; 95% CI, -7.96 to -0.25). Patients who discontinued IBD medication scored higher than those with irregular medication use (p = 0.020; 95% CI, 1.00 to 10.90). CONCLUSIONS: This study highlights the significant impact of the COVID-19 pandemic on the HRQoL of IBD patients. The findings emphasize the need for integrated care addressing both the physical and psychological aspects of IBD.


Assuntos
COVID-19 , Doenças Inflamatórias Intestinais , Qualidade de Vida , Humanos , COVID-19/epidemiologia , COVID-19/psicologia , Masculino , Feminino , Estudos Transversais , China/epidemiologia , Adulto , Pessoa de Meia-Idade , Doenças Inflamatórias Intestinais/psicologia , Doenças Inflamatórias Intestinais/tratamento farmacológico , SARS-CoV-2 , Adesão à Medicação/estatística & dados numéricos , Adesão à Medicação/psicologia , Inquéritos e Questionários , Adulto Jovem , Política de Saúde
19.
Cost Eff Resour Alloc ; 22(1): 38, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38711056

RESUMO

BACKGROUND: Surgical staplers have been widely used to facilitate surgeries, and this study aimed to examine the real-world effectiveness of a new powered stapling system with Gripping Surface Technology (GST) on intraoperative outcomes of gastrectomy for gastric cancer. METHOD: The data were extracted from the Fourth Hospital of Hebei Medical University's (FHHMU) medical records system. Participants (N = 121 patients) were classified into the GST (n = 59) or non-GST group (n = 62), based on the use of the GST system. The intraoperative outcomes such as bleeding were assessed by reviewing video records. T-tests, Chi-square tests, and Mann-Whitney-U tests were used to compare the baseline characteristics between groups. Multivariate logistic regression was conducted for adjusting outcomes to study the effect of variables. RESULTS: Compared with the non-GST group, the GST group had significantly lower risks for intraoperative bleeding, intraoperative anastomosis intervention rate, intraoperative suture, and intraoperative pression (aORs: 0.0853 (p < 0.0001), 0.076 (p = 0.0003), 0.167 (p = 0.0012), and 0.221 (p = 0.0107), respectively). The GST group also consumed one fewer cartridge than the non-GST group (GST:5 vs non-GST: 6, p = 0.0241). CONCLUSION: The use of the GST system was associated with better intraoperative outcomes and lower cartridge consumption in Chinese real-world settings.

20.
Acta Pharmacol Sin ; 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39009651

RESUMO

Triple-negative breast cancer (TNBC) is incurable and prone to widespread metastasis. Therefore, identification of key targets for TNBC progression is urgently needed. Our previous study revealed that isotoosendanin (ITSN) reduced TNBC metastasis by targeting TGFßR1. ITSN is currently used as an effective chemical probe to further discover the key molecules involved in TNBC metastasis downstream of TGFßR1. The results showed that GOT2 was the gene downstream of Smad2/3 and that ITSN decreased GOT2 expression by abrogating the activation of the TGF-ß-Smad2/3 signaling pathway through directly binding to TGFßR1. GOT2 was highly expressed in TNBC, and its knockdown decreased TNBC metastasis. However, GOT2 overexpression reversed the inhibitory effect of ITSN on TNBC metastasis both in vitro and in vivo. GOT2 interacted with MYH9 and hindered its binding to the E3 ubiquitin ligase STUB1, thereby reducing MYH9 ubiquitination and degradation. Moreover, GOT2 also enhanced the translocation of MYH9 to mitochondria and thus induced DRP1 phosphorylation, thereby promoting mitochondrial fission and lamellipodia formation in TNBC cells. ITSN-mediated inhibition of mitochondrial fission and lamellipodia formation was associated with reduced GOT2 expression. In conclusion, ITSN prevented MYH9-regulated mitochondrial fission and lamellipodia formation in TNBC cells by enhancing MYH9 protein degradation through a reduction in GOT2 expression, thus contributing to its inhibition of TNBC metastasis.

SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa