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1.
Nature ; 627(8005): 754-758, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38093004

RESUMO

Shock-breakout emission is light that arises when a shockwave, generated by the core-collapse explosion of a massive star, passes through its outer envelope. Hitherto, the earliest detection of such a signal was at several hours after the explosion1, although a few others had been reported2-7. The temporal evolution of early light curves should provide insights into the shock propagation, including explosion asymmetry and environment in the vicinity, but this has been hampered by the lack of multiwavelength observations. Here we report the instant multiband observations of a type II supernova (SN 2023ixf) in the galaxy M101 (at a distance of 6.85 ± 0.15 Mpc; ref. 8), beginning at about 1.4 h after the explosion. The exploding star was a red supergiant with a radius of about 440 solar radii. The light curves evolved rapidly, on timescales of 1-2 h, and appeared unusually fainter and redder than predicted by the models9-11 within the first few hours, which we attribute to an optically thick dust shell before it was disrupted by the shockwave. We infer that the breakout and perhaps the distribution of the surrounding dust were not spherically symmetric.

2.
Immunity ; 53(2): 371-383.e5, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32673566

RESUMO

Cutaneous wound healing is associated with the unpleasant sensation of itching. Here we investigated the mechanisms underlying this type of itch, focusing on the contribution of soluble factors released during healing. We found high amounts of interleukin 31 (IL-31) in skin wound tissue during the peak of itch responses. Il31-/- mice lacked wound-induced itch responses. IL-31 was released by dermal conventional type 2 dendritic cells (cDC2s) recruited to wounds and increased itch sensory neuron sensitivity. Transfer of cDC2s isolated from late-stage wounds into healthy skin was sufficient to induce itching in a manner dependent on IL-31 expression. Addition of the cytokine TGF-ß1, which promotes wound healing, to dermal DCs in vitro was sufficient to induce Il31 expression, and Tgfbr1f/f CD11c-Cre mice exhibited reduced scratching and decreased Il31 expression in wounds in vivo. Thus, cDC2s promote itching during skin would healing via a TGF-ß-IL-31 axis with implications for treatment of wound itching.


Assuntos
Interleucinas/metabolismo , Células de Langerhans/fisiologia , Prurido/patologia , Células Receptoras Sensoriais/fisiologia , Fator de Crescimento Transformador beta1/metabolismo , Animais , Feminino , Humanos , Interleucinas/genética , Células de Langerhans/transplante , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Receptores de Interleucina/metabolismo , Pele/citologia , Pele/crescimento & desenvolvimento , Pele/lesões , Canais de Cátion TRPV/metabolismo , Cicatrização/fisiologia
3.
Nano Lett ; 24(10): 3118-3124, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38421801

RESUMO

The magnetic and electric dipoles of ferroics play a central role in their fascinating properties. In particular, topological configurations have shown promising potential for use in novel electromechanical and electronic devices. Magnetic configurations from simple collinear to complex topological are well-documented. In contrast, many complex topological features in the electric counterpart remain unexplored. Here, we report the first example of three-dimensional electric dipole sinewave topological structure in a PbZrO3-based bulk perovskite, which presents an interesting triple-hysteresis loop macroscopically. This polar configuration consists of two orthogonal sinewave electric dipole modulations decoded from a polar incommensurate phase by advanced diffraction and atomic-resolution imaging techniques. The resulting topology is unraveled to be the competition between the antiferroelectric and ferroelectric states, stabilized by the modulation of the Pb 6s2 lone pair and the antiferrodistortive effect. These findings further reinforce the similarity of the magnetic and electric topologies.

4.
Nano Lett ; 24(22): 6743-6752, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38783628

RESUMO

Lipid nanoparticles (LNPs) represent the forefront of mRNA delivery platforms, yet achieving precise delivery to specific cells remains a challenge. The current targeting strategies complicate the formulation and impede the regulatory approval process. Here, through a straightforward regulation of helper lipids within LNPs, we introduce an engineered LNP designed for targeted delivery of mRNA into hepatocytes for metabolic dysfunction-associated fatty liver disease (MAFLD) treatment. The optimized LNP, supplied with POPC as the helper lipid, exhibits a 2.49-fold increase in mRNA transfection efficiency in hepatocytes compared to that of FDA-approved LNPs. CTP:phosphocholine cytidylyltransferase α mRNA is selected for delivery to hepatocytes through the optimized LNP system for self-calibration of phosphatidylcholine levels to prevent lipid droplet expansion in MAFLD. This strategy effectively regulates lipid homeostasis, while demonstrating proven biosafety. Our results present a mRNA therapy for MAFLD and open a new avenue for discovering potent lipids enabling mRNA delivery to specific cells.


Assuntos
Hepatócitos , Nanopartículas , Fosfatidilcolinas , RNA Mensageiro , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Humanos , Hepatócitos/metabolismo , Fosfatidilcolinas/química , Nanopartículas/química , Animais , Transfecção/métodos , Colina-Fosfato Citidililtransferase/genética , Colina-Fosfato Citidililtransferase/metabolismo , Fígado Gorduroso/terapia , Fígado Gorduroso/genética , Fígado Gorduroso/metabolismo , Lipídeos/química , Técnicas de Transferência de Genes , Camundongos , Lipossomos
5.
EMBO J ; 39(3): e102374, 2020 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-31830314

RESUMO

Renewal of integumentary organs occurs cyclically throughout an organism's lifetime, but the mechanism that initiates each cycle remains largely unknown. In a miniature pig model of tooth development that resembles tooth development in humans, the permanent tooth did not begin transitioning from the resting to the initiation stage until the deciduous tooth began to erupt. This eruption released the accumulated mechanical stress inside the mandible. Mechanical stress prevented permanent tooth development by regulating expression and activity of the integrin ß1-ERK1-RUNX2 axis in the surrounding mesenchyme. We observed similar molecular expression patterns in human tooth germs. Importantly, the release of biomechanical stress induced downregulation of RUNX2-wingless/integrated (Wnt) signaling in the mesenchyme between the deciduous and permanent tooth and upregulation of Wnt signaling in the epithelium of the permanent tooth, triggering initiation of its development. Consequently, our findings identified biomechanical stress-associated Wnt modulation as a critical initiator of organ renewal, possibly shedding light on the mechanisms of integumentary organ regeneration.


Assuntos
Regulação para Baixo , Odontogênese , Via de Sinalização Wnt , Animais , Fenômenos Biomecânicos , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Saco Dentário/citologia , Saco Dentário/metabolismo , Humanos , Integrina beta1/metabolismo , Modelos Biológicos , Cultura Primária de Células , Suínos , Porco Miniatura
6.
Oncologist ; 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38902966

RESUMO

BACKGROUND: The prognostic significance of lymph node metastasis (LNM) in papillary thyroid carcinoma (PTC) remains controversial. Notably, there is evidence suggesting an association between tissue stiffness and the aggressiveness of the disease. We therefore aimed to explore the effect of tissue stiffness on LNM-related invasiveness in PTC patients. METHOD: A total of 2492 PTC patients from 3 hospitals were divided into an LNM group and a non-LNM group based on their pathological results. The effects of interior lesion stiffness (E) and peri-cancerous tissue stiffness (Eshell) on the LNM-related recurrence rate and mortality in each patient with PTC subgroup were analyzed. The activation of cancer-associated fibroblasts (CAFs) and extracellular matrix component type 1 collagen (COL-I) in the lesion were compared and analyzed across different subgroups. The underlying biological basis of differences in each subgroup was identified using RNA sequencing (RNA-seq) data. RESULTS: The Eshell value and Eshell/E in the LNM group were significantly higher than those in the non-LNM group of patients with PTC (Eshell: 72.72 ±â€…5.63 vs 66.05 ±â€…4.46; Eshell/E: 1.20 ±â€…1.72 vs 1.09 ±â€…1.10, P < .001). When Eshell/E > 1.412 and LNM were both present, the recurrence rate and mortality were significantly increased compared to those of group of patients with LNM (91.67% and 7.29%, respectively). The CAF activation and COL-I content in the Eshell/E+ group were significantly higher than those in the Eshell/E- group (all P < .001), and the RNA-seq results revealed significant extracellular matrix (ECM) remodeling in the LNM-Eshell/E+ group. CONCLUSIONS: Stiff peri-cancerous tissue induced CAF activation, COL-I deposition, and ECM remodeling, resulting in a poor prognosis for PTC patients with LNM.

7.
Anal Chem ; 96(10): 4299-4307, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38414258

RESUMO

To boost the enzyme-like activity, biological compatibility, and antiaggregation effect of noble-metal-based nanozymes, folic-acid-strengthened Ag-Ir quantum dots (FA@Ag-Ir QDs) were developed. Not only did FA@Ag-Ir QDs exhibit excellent synergistic-enhancement peroxidase-like activity, high stability, and low toxicity, but they could also promote the lateral root propagation of Arabidopsis thaliana. Especially, ultratrace cysteine or Hg2+ could exclusively strengthen or deteriorate the inherent fluorescence property with an obvious "turn-on" or "turn-off" effect, and dopamine could alter the peroxidase-like activity with a clear hypochromic effect from blue to colorless. Under optimized conditions, FA@Ag-Ir QDs were successfully applied for the turn-on fluorescence imaging of cysteine or the stress response in cells and plant roots, the turn-off fluorescence monitoring of toxic Hg2+, or the visual detection of dopamine in aqueous, beverage, serum, or medical samples with low detection limits and satisfactory recoveries. The selective recognition mechanisms for FA@Ag-Ir QDs toward cysteine, Hg2+, and dopamine were illustrated. This work will offer insights into constructing some efficient nanozyme sensors for multichannel environmental analyses, especially for the prediagnosis of cysteine-related diseases or stress responses in organisms.


Assuntos
Mercúrio , Pontos Quânticos , Pontos Quânticos/toxicidade , Cisteína , Dopamina , Ácido Fólico , Imagem Óptica , Peroxidases , Raízes de Plantas
8.
J Transl Med ; 22(1): 570, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38879538

RESUMO

BACKGROUND: Gut microbiota (GM) have been implicated as important regulators of gastrointestinal symptom which is commonly occurred along with respiratory influenza A virus (IAV) infection, suggesting the involvement of the gut-to-lung axis in a host's response to IAV. IAV primarily destroys airway epithelium tight junctions (TJs) and consequently causes acute respiratory disease syndrome. It is known that GM and their metabolism produce an anti-influenza effect, but their role in IAV-induced airway epithelial integrity remains unknown. METHODS: A mouse model of IAV infection was established. GM were analyzed using 16S rRNA gene sequencing, and short-chain fatty acids (SCFAs) levels were measured. GM depletion and fecal microbiota transplantation (FMT) were conducted to validate the role of GM in IAV infection. A pair-feeding experiment was conducted to reveal whether IAV-induced GM dysbiosis is attributed to impaired food intake. Furthermore, human bronchial epithelial (HBE) cells were cocultured with IAV in the presence or absence of acetate. TJs function was analyzed by paracellular permeability and transepithelial electronic resistance (TEER). The mechanism of how acetate affects TJs integrity was evaluated in HBE cells transfected with G protein-coupled receptor 43 (GPR43) short hairpin RNA (shRNA). RESULTS: IAV-infected mice exhibited lower relative abundance of acetate-producing bacteria (Bacteroides, Bifidobacterium, and Akkermansia) and decreased acetate levels in gut and serum. These changes were partly caused by a decrease in food consumption (due to anorexia). GM depletion exacerbated and FMT restored IAV-induced lung inflammatory injury. IAV infection suppressed expressions of TJs (occludin, ZO-1) leading to disrupted airway epithelial barrier function as evidenced by decreased TEER and increased permeability. Acetate pretreatment activated GPR43, partially restored IAV-induced airway epithelial barrier function, and reduced inflammatory cytokines levels (TNF-α, IL-6, and IL-1ß). Such protective effects of acetate were absent in HBE cells transfected with GPR43 shRNA. Acetate and GPR43 improved TJs in an AMP-activated protein kinase (AMPK)-dependent manner. CONCLUSION: Collectively, our results demonstrated that GM protected airway TJs by modulating GPR43-AMPK signaling in IAV-induced lung injury. Therefore, improving GM dysbiosis may be a potential therapeutic target for patients with IAV infection.


Assuntos
Acetatos , Microbioma Gastrointestinal , Lesão Pulmonar , Infecções por Orthomyxoviridae , Junções Íntimas , Animais , Junções Íntimas/metabolismo , Microbioma Gastrointestinal/efeitos dos fármacos , Acetatos/metabolismo , Humanos , Infecções por Orthomyxoviridae/complicações , Camundongos Endogâmicos C57BL , Vírus da Influenza A , Transplante de Microbiota Fecal , Receptores Acoplados a Proteínas G/metabolismo , Camundongos , Células Epiteliais/metabolismo , Disbiose , Ácidos Graxos Voláteis/metabolismo
9.
Appl Environ Microbiol ; 90(2): e0110723, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38231769

RESUMO

The effects of Neolamarckia cadamba leaves extract (NCLE), with effective ingredients of flavonoids, on antibiotic resistance genes (ARGs) and relevant microorganisms in cecal contents and feces of broilers treated with or without lipopolysaccharide stimulation (LPS) were investigated. LPS stimulation increased (P < 0.05) the relative abundance of ARGs and mobile genetic elements (MGEs), such as tet(W/N/W), APH(3')-IIIa, ErmB, tet (44), ANT (6)-Ia, tet(O), tet (32), Vang_ACT_CHL, myrA, ANT (6)-Ib, IncQ1, tniB, and rep2 in cecal contents. However, the difference disappeared (P > 0.05) when NCLE was added at the same time. These differential ARGs and MGEs were mainly correlated (P < 0.01) with Clostridiales bacterium, Lachnospiraceae bacterium, and Candidatus Woodwardibium gallinarum. These species increased in LPS-stimulated broilers and decreased when NCLE was applied at the same time. In feces, LPS stimulation decreased (P < 0.05) the relative abundance of tet(Q), adeF, ErmF, Mef(En2), OXA-347, tet (40), npmA, tmrB, CfxA3, and ISCrsp1, while the LPS + NCLE treated group showed no significant effect (P > 0.05) on these ARGs. These differential ARGs and MGEs in feces were mainly correlated (P < 0.01) with Clostridiales bacterium, Pseudoflavonifractor sp. An184, Flavonifractor sp. An10, Ruminococcaceae bacterium, etc. These species increased in LPS-stimulated broilers and increased when NCLE was applied at the same time. In conclusion, LPS stimulation and NCLE influenced microbial communities and associated ARGs in both cecal contents and feces of broilers. NCLE alleviated the change of ARGs and MGEs in LPS-induced broilers by maintaining the microbial balance.IMPORTANCEAntibiotics showed a positive effect on gut health regulation and growth performance improvement in livestock breeding, but the antimicrobial resistance threat and environment pollution problem are increasingly severe with antibiotics abuse. As alternatives, plant extract containing bioactive substances are increasingly used to improve immunity and promote productivity. However, little is known about their effects on diversity and abundance of ARGs. Here, we investigated the effects of NCLE, with effective ingredients of flavonoids, on ARGs and relevant microorganisms in cecal contents and feces of broilers treated with or without lipopolysaccharide stimulation. We found that NCLE reduced the abundance of ARGs in cecal contents of lipopolysaccharide-induced broilers by maintaining the microbial balance. This study provides a comprehensive view of cecal and fecal microbial community, ARGs, and MGEs of broiler following LPS stimulation and NCLE treatment. It might be used to understand and control ARGs dissemination in livestock production.


Assuntos
Lactobacillales , Microbiota , Animais , Antibacterianos/farmacologia , Lipopolissacarídeos , Galinhas/genética , Genes Bacterianos , Melhoramento Vegetal , Resistência Microbiana a Medicamentos/genética , Fezes , Bactérias/genética , Lactobacillales/genética , Flavonoides/farmacologia
10.
Mol Ecol ; 33(3): e17238, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38108198

RESUMO

Limited knowledge of bird microbiome in the all-body niche hinders our understanding of host-microbial relationships and animal health. Here, we characterized the microbial composition of the crested ibis from 13 body sites, representing the cloaca, oral, feather and skin habitats, and explored assembly mechanism structuring the bacterial community of the four habitats respectively. The bacterial community characteristics were distinct among the four habitats. The skin harboured the highest alpha diversity and most diverse functions, followed by feather, oral and cloaca. Individual-specific features were observed when the skin and feathers were concentrated independently. Skin and feather samples of multiple body sites from the same individual were more similar than those from different individuals. Although a significant proportion of the microbiota in the host (85.7%-96.5%) was not derived from the environmental microbiome, as body sites became more exposed to the environment, the relative importance of neutral processes (random drift or dispersal) increased. Neutral processes were the most important contributor in shaping the feather microbiome communities (R2 = .859). A higher percentage of taxa (29.3%) on the skin were selected by hosts compared to taxa on other body habitats. This study demonstrated that niche speciation and partial neutral processes, rather than environmental sources, contribute to microbiome variation in the crested ibis. These results enhance our knowledge of baseline microbial diversity in birds and will aid health management in crested ibises in the future.


Assuntos
Aves , Microbiota , Animais , Bactérias , Plumas
11.
Chemistry ; 30(12): e202303208, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38038726

RESUMO

Fluorophores are considered powerful tools for not only enabling the visualization of cell structures, substructures, and biological processes, but also making for the quantitative and qualitative measurement of various analytes in living systems. However, most fluorophores do not meet the diverse requirements for biological applications in terms of their photophysical and biological properties. Hybridization is an important strategy in molecular engineering that provides fluorophores with complementarity and multifunctionality. This review summarizes the basic strategies of hybridization with four classes of fluorophores, including xanthene, cyanine, coumarin, and BODIPY with a focus on their structure-property relationship (SPR) and biological applications. This review aims to provide rational hybrid ideas for expanding the reservoir of knowledge regarding fluorophores and promoting the development of newly produced fluorophores for applications in the field of life sciences.


Assuntos
Corantes Fluorescentes , Xantenos , Corantes Fluorescentes/química , Xantenos/química , Ionóforos
12.
J Magn Reson Imaging ; 59(3): 825-834, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37338016

RESUMO

BACKGROUND: Few studies assessed myocardial inflammation using Cardiovascular Magnetic Resonance Imaging in Kawasaki disease (KD) patients. PURPOSE: To quantify myocardial edema in KD patients using T2 mapping and explore the independent predictors of T2 values. STUDY TYPE: Prospective. SUBJECTS: Ninety KD patients including 40 in acute phase (26 males, 65.0%) and 50 in chronic phase (34 males, 68.0%). Thirty-one healthy volunteers (21 males, 70.0%). FIELD STRENGTH/SEQUENCE: 3.0 T T2-weighted Turbo Spin Echo-Short Time of Inversion Recovery sequence, True fast imaging with steady precession flash sequence and fast low-angle shot 3D spoiled gradient echo sequence. ASSESSMENT: T2 values were compared among KD groups and controls. STATISTICAL TEST: Student's t test and Fisher's exact test; One-way analysis of variance; Pearson correlation analysis; Receiver operating curve analysis; Multivariable linear regression. RESULTS: Global T2 value of KD patients in acute phase was the highest, followed by those of chronic-phase patients and controls (38.83 ± 2.41 msec vs. 37.55 ± 2.28 msec vs. 36.05 ± 1.64 msec). Regional T2 values showed a same trend. There were no significant differences in global and regional T2 values between KD patients with and without coronary artery (CA) dilation, no matter in acute or chronic phase (all KD patients: P = 0.51, 0.51, 0.53, 0.72; acute KD: P = 0.61, 0.37, 0.33, 0.83; chronic KD: P = 0.65, 0.79, 0.62, 0.79). No significant difference was observed in global T2 values between KD patients with Z score > 5.0 and 2.0 < Z score ≤ 5.0 (P = 0.65). Multivariate analysis demonstrated that stage of disease (ß = -0.123) and heart rate (ß = 0.280) were independently associated with global T2 values. DATA CONCLUSION: The degree of myocardial edema was more severe in acute-phase than in chronic-phase KD patients. Myocardial edema persists in patients regardless of the existence or degree of CA dilation. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.


Assuntos
Síndrome de Linfonodos Mucocutâneos , Masculino , Criança , Humanos , Estudos Prospectivos , Miocárdio/patologia , Imageamento por Ressonância Magnética/métodos , Edema
13.
Br J Clin Pharmacol ; 90(2): 440-451, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37766511

RESUMO

AIMS: The aim of this study was to explore the influence and possible mechanisms of pharmacokinetics-related gene polymorphisms, especially CYP2C19 polymorphisms, and non-genetic factors combined with the inflammatory status on the voriconazole (VRC) metabolism of the Chinese population. METHODS: Clinical studies were performed by collecting more than one VRC trough concentration and C-reactive protein (CRP) level. A total of 265 blood samples were collected from 120 patients. RESULTS: Results of multiple regression analyses demonstrated that CYP2C19 genotypes and albumin (Alb) level remained predictors of Cmin ss/D in patients with no to mild inflammation (R2 = 0.12, P < .001). In addition, in patients with moderate to severe inflammation, it resulted in a significant model containing factors of CRP and total bilirubin (T-Bil) levels (R2 = 0.19, P < .001). In non-clinical studies, 32 rats were divided into control and inflammatory groups, and it was found that the mean residence time (MRT(0-t) ) of VRC in the inflammatory group was significantly longer than that in the control group (P < .001), which may be due to down-regulation of mRNA and protein expression of CYP2C19 (CYP2C6 in rats) through interleukin (IL)-6/signal transducer and activator of transcription (STAT) 3 pathway. CONCLUSIONS: Therefore, the effect of CYP2C19 polymorphisms on VRC metabolism may be masked by inflammatory status, which should be of more concern than CYP2C19 polymorphisms in patients with moderate to severe inflammation. Additionally, the impact of Alb and T-Bil on VRC metabolism should not be disregarded.


Assuntos
Antifúngicos , Inflamação , Humanos , Animais , Ratos , Voriconazol/uso terapêutico , Antifúngicos/uso terapêutico , Citocromo P-450 CYP2C19/genética , Inflamação/tratamento farmacológico , China , Genótipo
14.
J Org Chem ; 89(3): 1465-1472, 2024 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-38251869

RESUMO

Enzyme-catalyzed dynamic kinetic resolution was applied to the one-pot regio- and enantioselective synthesis of 2,5-disubstituted tetrazole hemiaminal esters, among which 72% of the products were obtained in excellent enantiopurities (99% ees). Tunable stereoselectivity was achieved by using different types of enzymes during the synthesis of a key intermediate for a clinic drug candidate. Successful preparation of tetrazole ester prodrugs and high catalyst recyclability further demonstrated the potential practical application of this protocol.


Assuntos
Ésteres , Tetrazóis , Estereoisomerismo , Biocatálise , Catálise
15.
Chem Rev ; 122(9): 8438-8486, 2022 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-35258938

RESUMO

Negative thermal expansion (NTE), referring to the lattice contraction upon heating, has been an attractive topic of solid-state chemistry and functional materials. The response of a lattice to the temperature field is deeply rooted in its structural features and is inseparable from the physical properties. For the past 30 years, great efforts have been made to search for NTE compounds and control NTE performance. The demands of different applications give rise to the prominent development of new NTE systems covering multifarious chemical substances and many preparation routes. Even so, the intelligent design of NTE structures and efficient tailoring for lattice thermal expansion are still challenging. However, the diverse chemical routes to synthesize target compounds with featured structures provide a large number of strategies to achieve the desirable NTE behaviors with related properties. The chemical diversity is reflected in the wide regulating scale, flexible ways of introduction, and abundant structure-function insights. It inspires the rapid growth of new functional NTE compounds and understanding of the physical origins. In this review, we provide a systematic overview of the recent progress of chemical diversity in the tailoring of NTE. The efficient control of lattice and deep structural deciphering are carefully discussed. This comprehensive summary and perspective for chemical diversity are helpful to promote the creation of functional zero-thermal-expansion (ZTE) compounds and the practical utilization of NTE.

16.
Anal Bioanal Chem ; 416(8): 1951-1959, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38324071

RESUMO

To conveniently monitor bioactive cysteine (Cys) and Fe2+ in practice, a kind of poly-ß-cyclodextrin strengthen praseodymium oxide (Pr6O11) porous oxidase mimic (p-ß-CD@Pr6O11) was constructed by virtue of the strong coordination between nano Pr6O11 and poly-ß-cyclodextrin substrate. After its microstructure and physicochemical property were characterized in detail, it was noted that porous p-ß-CD@Pr6O11 exhibited excellent enzyme-like catalytic activity to accelerate the oxidation of 3,3',5,5,'-tetramethylbanzidine (TMB) and 2,2'-azinobis (3-ethylbenzo-thiazoline-6-sulfonic acid) ammonium salt (ABTS) with significant color-enhancement effect in the air. Based on the signal amplification, trace Cys could exclusively deteriorate the UV-vis absorbance at 653 nm of p-ß-CD@Pr6O11-TMB and Fe2+ alter the one at 729 nm of p-ß-CD@Pr6O11-ABTS with visual color changes. Under the optimized conditions, the proposed p-ß-CD@Pr6O11-TMB and p-ß-CD@Pr6O11-ABTS systems were successfully applied for dual-channel monitoring of Cys in Cys capsules and fetal bovine serum and Fe2+ in agricultural products with quite low detection limits, i.e., 7.8×10-9 mol·L-1 for Cys and 6.93×10-8 mol·L-1 (S/N=3) for Fe2+, respectively. The synergetic-enhancement detection mechanisms to Cys and Fe2+ were also proposed.


Assuntos
Benzotiazóis , Oxirredutases , Ácidos Sulfônicos , beta-Ciclodextrinas , Cisteína/química , Porosidade , beta-Ciclodextrinas/química , Colorimetria
17.
Nature ; 557(7705): 413-417, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29769666

RESUMO

The Montreal Protocol was designed to protect the stratospheric ozone layer by enabling reductions in the abundance of ozone-depleting substances such as chlorofluorocarbons (CFCs) in the atmosphere1-3. The reduction in the atmospheric concentration of trichlorofluoromethane (CFC-11) has made the second-largest contribution to the decline in the total atmospheric concentration of ozone-depleting chlorine since the 1990s 1 . However, CFC-11 still contributes one-quarter of all chlorine reaching the stratosphere, and a timely recovery of the stratospheric ozone layer depends on a sustained decline in CFC-11 concentrations 1 . Here we show that the rate of decline of atmospheric CFC-11 concentrations observed at remote measurement sites was constant from 2002 to 2012, and then slowed by about 50 per cent after 2012. The observed slowdown in the decline of CFC-11 concentration was concurrent with a 50 per cent increase in the mean concentration difference observed between the Northern and Southern Hemispheres, and also with the emergence of strong correlations at the Mauna Loa Observatory between concentrations of CFC-11 and other chemicals associated with anthropogenic emissions. A simple model analysis of our findings suggests an increase in CFC-11 emissions of 13 ± 5 gigagrams per year (25 ± 13 per cent) since 2012, despite reported production being close to zero 4 since 2006. Our three-dimensional model simulations confirm the increase in CFC-11 emissions, but indicate that this increase may have been as much as 50 per cent smaller as a result of changes in stratospheric processes or dynamics. The increase in emission of CFC-11 appears unrelated to past production; this suggests unreported new production, which is inconsistent with the Montreal Protocol agreement to phase out global CFC production by 2010.

18.
BMC Health Serv Res ; 24(1): 44, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38195476

RESUMO

BACKGROUND: Hospital Examination Reservation System (HERS) was designed for reducing appointment examination waiting time and enhancing patients' medical satisfaction in China, but implementing HERS would encounter many difficulties. This study would investigate the factors that influence patients' utilization of HERS through UTAUT2, and provide valuable insights for hospital managements to drive the effective implementation of HERS. It is helpful for improving patients' medical satisfaction. METHODS: We conducted a survey through the Sojump platform, targeting patients were who have already used HERS. We collected questionnaire information related to factors behavior intention, performance expectancy, and effort expectancy. Subsequently, we employed a structural equation model to analyze the factors influencing patients' utilization of HERS. RESULTS: A total of 394 valid questionnaires were collected. Habit was the main direct positive factor influencing the behavioral intention of HERS (ß = 0.593; 95%CI: 0.072, 1.944; P = 0.002), followed by patient innovation (ß = 0.269; 95%CI: 0.002, 0.443; P < 0.001), effort expectancy (ß = 0.239; 95%CI: -0.022, 0.478; P = 0.048). Patient innovation and facilitating conditions also have an indirect effect on behavioral intention. Perceived privacy exposure has a significantly negative effect on behavioral intention (ß=-0.138; 95%CI: -0.225, -0.047; P < 0.001). The above variables explained 56.7% of the variation in behavioral intention. CONCLUSIONS: When HERS is implemented in hospitals, managements should arrange volunteers to guide patients to bring up the habit and solve the using difficulties, and managements could invite patients with high innovation to recommend HERS to others, what's more, it is a valid way to retain the old form of appointment to pass the transition period to the new system. HERS utilization and patients' medical satisfaction will be enhanced through the guidance of hospital management means.


Assuntos
Hospitais , Intenção , Humanos , Feminino , China , Satisfação do Paciente , Privacidade
19.
Mar Drugs ; 22(6)2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38921582

RESUMO

Cyclic glycine-proline (cGP), a prevalent marine cyclic dipeptide, possesses a distinct pyrrolidine-2,5-dione scaffold, which contributes to the chemical diversity and broad bioactivities of cGP. The diverse sources from marine-related, endogenous biological, and synthetic pathways and the in vitro and in vivo activities of cGP are reviewed. The potential applications for cGP are also explored. In particular, the pivotal roles of cGP in regulating insulin-like growth factor-1 homeostasis, enhancing neuroprotective effects, and improving neurotrophic function in central nervous system diseases are described. The potential roles of this endogenous cyclic peptide in drug development and healthcare initiatives are also highlighted. This review underscores the significance of cGP as a fundamental building block in drug discovery with exceptional drug-like properties and safety. By elucidating the considerable value of cGP, this review aims to reignite interest in cGP-related research within marine medicinal chemistry and synthetic biology.


Assuntos
Organismos Aquáticos , Dipeptídeos , Peptídeos Cíclicos , Animais , Dipeptídeos/farmacologia , Dipeptídeos/química , Peptídeos Cíclicos/farmacologia , Peptídeos Cíclicos/química , Humanos , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/química , Descoberta de Drogas/métodos , Glicina/farmacologia , Glicina/análogos & derivados
20.
Proc Natl Acad Sci U S A ; 118(33)2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34380737

RESUMO

In the Arctic and Boreal region (ABR) where warming is especially pronounced, the increase of gross primary production (GPP) has been suggested as an important driver for the increase of the atmospheric CO2 seasonal cycle amplitude (SCA). However, the role of GPP relative to changes in ecosystem respiration (ER) remains unclear, largely due to our inability to quantify these gross fluxes on regional scales. Here, we use atmospheric carbonyl sulfide (COS) measurements to provide observation-based estimates of GPP over the North American ABR. Our annual GPP estimate is 3.6 (2.4 to 5.5) PgC · y-1 between 2009 and 2013, the uncertainty of which is smaller than the range of GPP estimated from terrestrial ecosystem models (1.5 to 9.8 PgC · y-1). Our COS-derived monthly GPP shows significant correlations in space and time with satellite-based GPP proxies, solar-induced chlorophyll fluorescence, and near-infrared reflectance of vegetation. Furthermore, the derived monthly GPP displays two different linear relationships with soil temperature in spring versus autumn, whereas the relationship between monthly ER and soil temperature is best described by a single quadratic relationship throughout the year. In spring to midsummer, when GPP is most strongly correlated with soil temperature, our results suggest the warming-induced increases of GPP likely exceeded the increases of ER over the past four decades. In autumn, however, increases of ER were likely greater than GPP due to light limitations on GPP, thereby enhancing autumn net carbon emissions. Both effects have likely contributed to the atmospheric CO2 SCA amplification observed in the ABR.

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