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1.
J Am Chem Soc ; 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38985576

RESUMO

Installing fluorine atoms onto natural products holds great promise for the generation of fluorinated molecules with improved or novel pharmacological properties. The enzymatic oxidative carbon-carbon coupling reaction represents a straightforward strategy for synthesizing biaryl architectures, but the exploration of this method for producing fluorine-substituted derivatives of natural products remains elusive. Here, in this study, we report the protein engineering of cytochrome P450 from Mycobacterium tuberculosis (MtCYP121) for the construction of a series of new-to-nature fluorine-substituted Mycocyclosin derivatives. This protocol takes advantage of a "hybrid" chemoenzymatic procedure consisting of tyrosine phenol lyase-catalyzed fluorotyrosine preparation from commercially available fluorophenols, intermolecular chemical condensation to give cyclodityrosines, and an engineered MtCYP121-catalyzed intramolecular biphenol coupling reaction to complete the strained macrocyclic structure. Computational mechanistic studies reveal that MtCYP121 employs Cpd I to abstract a hydrogen atom from the proximal phenolic hydroxyl group of the substrate to trigger the reaction. Then, conformational change makes the two phenolic hydroxyl groups close enough to undergo intramolecular hydrogen atom transfer with the assistance of a pocket water molecule. The final diradical coupling process completes the intramolecular C-C bond formation. The efficiency of the biaryl coupling reaction was found to be influenced by various fluorine substitutions, primarily due to the presence of distinct binding conformations.

2.
Angew Chem Int Ed Engl ; : e202407689, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38845586

RESUMO

A photocatalyzed formal (3+2) cycloaddition has been developed to construct original polysubstituted α-SCF3 cyclopentanones in a regio- and diastereoselective manner. This building block approach leverages trifluoromethylthio alkynes and branched / linear aldehydes, as readily available reaction partners, in consecutive hydrogen atom transfers and C-C bond formations. Difluoromethylthio alkynes are also compatible subtrates. Furthermore, the potential for telescoped reaction starting from alcohols instead of aldehydes was demonstrated, as well as process automatization and scale-up under continuous microflow conditions. This prompted density functional theory calculations to support a free radical-mediated cascade hydrogen atom transfer process.

3.
Phys Rev E ; 109(5-1): 054301, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38907509

RESUMO

Fiedler value, as the minimal real part of (or the minimal) nonzero Laplacian eigenvalue, garners significant attention as a metric for evaluating network topology and its dynamics. In this paper, we address the quantification relation between Fiedler value and each edge in a directed complex network, considering undirected networks as a special case. We propose an approach to measure the dynamical contribution value of each edge. Interestingly, these contribution values can be both positive and negative, which are determined by the left and right Fiedler vectors. Further, we show that the cumulated dynamical contribution value of all edges is exactly the Fiedler value. This provides a promising angle on the Fiedler value in terms of dynamics and network structure. Therefore, the percentage of contribution of each edge to the Fiedler value is quantified. Numerical results reveal that network dynamics is significantly influenced by a small fraction of edges, say, one single directed edge contributes to over 90% of the Fiedler value in the Cat Cerebral Cortex network.

4.
Exp Mol Med ; 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38871817

RESUMO

MicroRNAs (miRNAs) are pivotal regulators of gene expression and are involved in biological processes spanning from early developmental stages to the intricate process of aging. Extensive research has underscored the fundamental role of miRNAs in orchestrating eukaryotic development, with disruptions in miRNA biogenesis resulting in early lethality. Moreover, perturbations in miRNA function have been implicated in the aging process, particularly in model organisms such as nematodes and flies. miRNAs tend to be clustered in vertebrate genomes, finely modulating an array of biological pathways through clustering within a single transcript. Although extensive research of their developmental roles has been conducted, the potential implications of miRNA clusters in regulating aging remain largely unclear. In this review, we use the Mir-23-27-24 cluster as a paradigm, shedding light on the nuanced physiological functions of miRNA clusters during embryonic development and exploring their potential involvement in the aging process. Moreover, we advocate further research into the intricate interplay among miRNA clusters, particularly the Mir-23-27-24 cluster, in shaping the regulatory landscape of aging.

5.
Biology (Basel) ; 13(5)2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38785814

RESUMO

This study aimed to evaluate the effects of physical measures and the applications of phosphorus fertilizer and soil conditioner on the growth of lettuce (Lactuca sativa) and its uptake of cadmium (Cd). In a solar greenhouse that contained soil enriched with cadmium (Cd) (1.75 ± 0.41 mg/kg) with lettuce used as a test plant, field experimental methods were utilized to explore the influence of physical measures, such as deep plowing and soil covering, and the applications of phosphorus fertilizer, including diammonium phosphate (DAP), calcium magnesium phosphate (CMP), and calcium superphosphate (SSP), and soil conditioners, such as biochar, attapulgite clay, and nano-hydroxyapatite, on the uptake of Cd in lettuce. The results indicated that the concentrations of Cd in the aboveground parts of lettuce were 1.49 ± 0.45, 1.26 ± 0.02, 1.00 ± 0.21, and 0.24 ± 0.13 mg/kg when the soil was plowed 30, 40, and 50 cm deep, respectively, and when the soil was covered with 15 cm, this resulted in reductions of 27.5%, 38.3%, 51.4%, and 88.4%, respectively, compared with the control treatment that entailed plowing to 15 cm. When 75, 150, and 225 kg/ha of phosphorus pentoxide (P2O5) were applied compared with the lack of application, the contents of Cd in the aboveground parts of lettuce increased by 2.0%, 54.5%, and 73.7%, respectively, when DAP was applied; by 52.5%, 48.5%, and 8.1%, respectively, when CMP was applied; and by 13.1%, 61.6%, and 90.9%, respectively, when SSP was applied. When the amounts of biochar applied were 0, 2, 4, 6, 8, 10, and 12 t/ha, the contents of Cd in the aboveground parts of lettuce were 1.36 ± 0.27, 1.47 ± 0.56, 1.80 ± 0.73, 1.96 ± 0.12, 1.89 ± 0.52, 1.44 ± 0.30, and 1.10 ± 0.27 mg/kg, respectively. Under concentrations of 0, 40, 80, 120, 160, and 200 kg/ha, the application of nano-hydroxyapatite resulted in Cd contents of 1.34 ± 0.56, 1.47 ± 0.10, 1.60 ± 0.44, 1.70 ± 0.21, 1.31 ± 0.09, and 1.51 ± 0.34 mg/kg, respectively. The concentrations of Cd in the aboveground parts of lettuce treated with attapulgite clay were 1.44 ± 0.48, 1.88 ± 0.67, 2.10 ± 0.80, 2.24 ± 0.75, 1.78 ± 0.41, and 1.88 ± 0.48 mg/kg, respectively. In summary, under the conditions in this study, deep plowing and soil covering measures can reduce the concentration of Cd in the aboveground parts of lettuce. The application of phosphorus fertilizer increased the concentration of Cd in the aboveground parts of lettuce. The application of higher amounts of DAP and SSP led to greater concentrations of Cd in the aboveground parts of lettuce. The application of higher amounts of CMP caused a lower concentration of Cd in the aboveground parts of lettuce. When biochar, attapulgite clay, and nano-hydroxyapatite were applied, the concentration of Cd in the aboveground parts of lettuce increased in parallel with the increase in the concentration of application when low amounts were applied. In contrast, when high amounts were applied, the concentration of Cd in the aboveground parts of lettuce began to decrease.

6.
Phys Chem Chem Phys ; 26(16): 12331-12344, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38598177

RESUMO

Oxaloacetic acid (OAA) is a ß-ketocarboxylic acid, which plays an important role as an intermediate in some metabolic pathways, including the tricarboxylic acid cycle, gluconeogenesis and fatty acid biosynthesis. Animal studies have indicated that supplementing oxaloacetic acid shows an increase of lifespan and other substantial health benefits including mitochondrial DNA protection, and protection of retinal, neural and pancreatic tissues. Most of the chemical transformations of OAA in the metabolic pathways have been extensively studied; however, the understanding of decarboxylation of OAA at the atomic level is relatively lacking. Here, we carried out MD simulations and combined quantum mechanical/molecular mechanical (QM/MM) calculations as an example to systematically elucidate the binding modes, keto-enol tautomerization and decarboxylation of OAA in the active site of macrophomate synthase (MPS), which is a Mg(II)-dependent bifunctional enzyme that catalyzes both the decarboxylation of OAA and [4+2] cycloaddition of 2-pyrone with the decarboxylated intermediate of OAA (pyruvate enolate). On the basis of our calculations, it was found that the Mg2+-coordinated oxaloacetate may exist in enol forms and keto forms. The four keto forms can be transformed into each other by simply rotating the C2-C3 single bond, nevertheless, the keto-enol tautomerization strictly requires the assistance of pocket water molecules. In addition, the decarboxylation is stereo-electronically controlled, i.e., it is the relative orientation of the terminal carboxyl anion that determines the rate of decarboxylation. As such, the chemistry of oxaloacetate in the active site of MPS is complex. On one hand, the most stable binding mode (K-I) may undergo enol-keto tautomerization to isomerize to the enol form, which may further react with the second substrate; on the other hand, K-I may isomerize to another binding mode K-II to proceed decarboxylation to generate pyruvate enolate and CO2. Starting from K-I, the enol-keto tautomerization corresponds to a barrier of 16.2 kcal mol-1, whereas the decarboxylation is associated with an overall barrier of 19.7 kcal mol-1. These findings may provide useful information for understanding the chemistry of OAA and the catalysis of related enzymes, and they are basically in agreement with the available experimental kinetic data.


Assuntos
Ascomicetos , Complexos Multienzimáticos , Domínio Catalítico , Descarboxilação , Simulação de Dinâmica Molecular , Ácido Oxaloacético/metabolismo , Ácido Oxaloacético/química , Teoria Quântica , Estereoisomerismo , Complexos Multienzimáticos/química , Ascomicetos/enzimologia
7.
PLoS One ; 19(3): e0295938, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38466758

RESUMO

In order to solve the problem that the skid resistance of concrete pavement in tunnel deteriorates rapidly, which is easy to cause traffic accidents, the anti-skid rapid elevation technology of surface treatment is proposed. Wear tests were used to investigate the effects of concrete surface roughness, properties of modified emulsified asphalt binder and anti-skid fine aggregate type on long-term skid resistance of treated surfaces. The results show that the four coarsening methods of fine milling, milling, grooving and brooming can improve the skid resistance of concrete, and the skid resistance durability of fine milling and milling is better. The adhesive property of modified emulsified asphalt is the best when the content of water-based epoxy resin is 20%. In different aggregates, the anti-skid effect is better when silicon carbide is used as anti-skid aggregate and the particle size is 0.6mm:0.3mm = 2:3. The method of fine milling of concrete surface + spraying epoxy emulsified asphalt + spreading silicon carbide can effectively improve the anti-skid performance of the original concrete pavement, and the feasibility of the scheme is verified by the test road. The research results have a good reference value for improving the skid resistance of tunnel concrete pavement.


Assuntos
Acidentes de Trânsito , Compostos Inorgânicos de Carbono , Hidrocarbonetos , Compostos de Silício , Tamanho da Partícula
8.
iScience ; 27(3): 109207, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38433925

RESUMO

Long noncoding RNAs (lncRNAs) play pivotal roles in modulating gene expression during development and disease. Despite their high expression in the central nervous system (CNS), understanding the precise physiological functions of CNS-associated lncRNAs has been challenging, largely due to the in vitro-centric nature of studies in this field. Here, utilizing mouse embryonic stem cell (ESC)-derived motor neurons (MNs), we identified an unexplored MN-specific lncRNA, Litchi (Long Intergenic RNAs in Chat Intron). By employing an "exon-only" deletion strategy in ESCs and a mouse model, we reveal that Litchi deletion profoundly impacts MN dendritic complexity, axonal growth, and altered action potential patterns. Mechanistically, voltage-gated channels and neurite growth-related genes exhibited heightened sensitivity to Litchi deletion. Our Litchi-knockout mouse model displayed compromised motor behaviors and reduced muscle strength, highlighting Litchi's critical role in motor function. This study unveils an underappreciated function of lncRNAs in orchestrating MN maturation and maintaining robust electrophysiological properties.

9.
PLoS One ; 19(3): e0301138, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38547107

RESUMO

The rheological properties of asphalt can well reflect its road performance, but the rheological properties of warm mix high viscosity asphalt (HVA) are unclear. In order to study the effect of warm mixing agent on rheological properties of HVA, two kinds of warm mixing agent EC120 (EC) and Evotherm M1 (M1) were selected to prepare warm mix HVA. The rheological properties of warm mix HVA at high temperature (135~195°C), medium temperature (0~80°C) and low temperature (-6~18°C) were studied by Brinell rotary viscosity test, dynamic shear rheological test (including temperature scanning, frequency scanning, linear amplitude scanning) and bending beam rheological test. The test results show that both EC and M1 have good viscosity reduction effect on HVA at high temperature, and can effectively reduce the construction temperature. At medium temperature, M1 can effectively improve the fatigue resistance of HVA, and the fatigue life can be increased by about 30% when the dosage is 0.6%. EC can increase the rutting factor of HVA and improve its resistance to deformation, but it will reduce its fatigue performance. When the dosage is 4%, the fatigue life will be reduced by about 9%. At low temperature, M1 can reduce the creep stiffness S, increase the creep rate m, and improve the low temperature performance of HVA, while EC has the opposite effect, weakening the low temperature performance of HVA. The results are helpful to understand the rheological properties of warm mix HVA and promote its application.


Assuntos
Temperatura Baixa , Hidrocarbonetos , Temperatura , Viscosidade
10.
J Cancer ; 15(8): 2193-2205, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38495485

RESUMO

With the development of guidance technology and ablation equipment, ablative procedures have emerged as important loco-regional alternatives to surgical resection for recurrent hepatocellular carcinoma (rHCC) patients. Currently, ablation modalities used in clinical practice mainly include radiofrequency ablation (RFA), microwave ablation (MWA), laser ablation (LA), cryoablation (CRA), high-intensity focused ultrasound (HIFU), and irreversible electroporation (IRE). Accumulated comparative data of ablation versus surgical resection reveal noninferior responses and outcomes but superior adverse effects. Moreover, studies demonstrate that ablation may serve as an excellent procedure for rHCC given its exact minimal invasiveness and immune modulation. We focus on the current status of ablation in clinical practice for rHCC and discuss new research in the field, including ablation combined with these other modalities, such as targeted therapy and immunotherapy.

11.
ChemMedChem ; 19(5): e202300623, 2024 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-38303683

RESUMO

It is of great importance to pinpoint specific residues or sites of a protein in biological contexts to enable desired mechanism of action for small molecules or to precisely control protein function. In this regard, acidic residues including aspartic acid (Asp) and glutamic acid (Glu) hold great potential due to their great prevalence and unique function. To unlock the largely untapped potential, great efforts have been made recently by synthetic chemists, chemical biologists and pharmacologists. Herein, we would like to highlight the remarkable progress and particularly introduce the electrophiles that exhibit reactivity to carboxylic acids, the light-induced reactivities to carboxylic acids and the genetically encoded noncanonical amino acids that allow protein manipulations at acidic residues. We also comment on certain unresolved challenges, hoping to draw more attention to this rapidly developing area.


Assuntos
Aminoácidos , Ácido Glutâmico , Ácido Aspártico , Ácidos Carboxílicos
12.
Bioconjug Chem ; 35(3): 400-411, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38366969

RESUMO

Photodynamic therapy (PDT) is a cancer treatment strategy that utilizes photosensitizers to convert oxygen within tumors into reactive singlet oxygen (1O2) to lyse tumor cells. Nevertheless, pre-existing tumor hypoxia and oxygen consumption during PDT can lead to an insufficient oxygen supply, potentially reducing the photodynamic efficacy. In response to this issue, we have devised a pH-responsive amphiphilic triblock fluorinated polymer (PDP) using copper-mediated RDRP. This polymer, composed of poly(ethylene glycol) methyl ether acrylate, 2-(diethylamino)ethyl methacrylate, and (perfluorooctyl)ethyl acrylate, self-assembles in an aqueous environment. Oxygen, chlorine e6 (Ce6), and doxorubicin (DOX) can be codelivered efficiently by PDP. The incorporation of perfluorocarbon into the formulation enhances the oxygen-carrying capacity of PDP, consequently extending the lifetime of 1O2. This increased lifetime, in turn, amplifies the PDT effect and escalates the cellular cytotoxicity. Compared with PDT alone, PDP@Ce6-DOX-O2 NPs demonstrated significant inhibition of tumor growth. This study proposes a novel strategy for enhancing the efficacy of PDT.


Assuntos
Nanopartículas , Fotoquimioterapia , Porfirinas , Humanos , Polímeros de Fluorcarboneto , Oxigênio , Linhagem Celular Tumoral , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Hipóxia/tratamento farmacológico , Concentração de Íons de Hidrogênio
13.
PLoS One ; 19(1): e0297090, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38252653

RESUMO

Crack is one of the main diseases of pavement structure. In order to improve the anti-reflective crack ability of pavement, fiber rubber gravel sealing layer is proposed as the stress absorbing layer. In view of the shortcoming that Mcleod design method can not be associated with road performance, a sealing layer optimization design method based on fatigue crack test is proposed. Firstly, the reinforcement effect of fiber on rubber asphalt was studied through force ductility testing. Secondly, the optimum dosage of fiber, asphalt and gravel was optimized through fatigue cracking resistance test. Finally, the cracking resistance of fiber rubber gravel seal was verified through fracture energy test. The results show that fibers can significantly increase the maximum tensile force and strain yield energy of rubber asphalt, and basalt fiber has the best reinforcement effect. The most obvious effect on cracking resistance performance in the sealing layer is the amount of fiber, followed by the amount of asphalt, and finally the amount of gravel. The optimized material combination with the best crack resistance is 120g/m2 fiber, 14kg/m2 gravel and 2.4kg/m2 rubber asphalt, and the fatigue resistance times can reach 19532 times. The fracture energy of the composite pavement treated by the optimized sealing layer is nearly double that of the non-treated pavement structure, and it has a good anti-crack effect.


Assuntos
Caniformia , Fraturas Ósseas , Focas Verdadeiras , Animais , Borracha , Hidrocarbonetos
14.
Environ Sci Pollut Res Int ; 31(9): 12995-13002, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38236570

RESUMO

Phytoremediation is an effective way to reduce heavy metal content in agricultural soil. The effects of brackish water irrigation on phytoremediation efficiency of plants have not yet been completely understood. In this study, the effects of brackish water irrigation on cadmium (Cd) uptake by maize as the phytoremediator were investigated. In a pot experiment, maize seedlings were grown in soil with exogenously added Cd (0, 5, 10, or 15 mg kg-1) and irrigated with deionized water (T1), natural brackish water (T2), or water with NaCl with salinity equal to that of natural brackish water (T3). Salt stress and cation antagonism caused by brackish water affected maize plant growth and Cd uptake. Under 5, 10, and 15 mg kg-1 Cd, Cd accumulation in maize shoots was 5.55, 7.08, and 5.71 µg plant-1; 4.08, 3.04, and 5.38 µg plant-1; and 2.48, 3.44, and 5.33 µg plant-1 under the T1, T2, and T3 treatments, respectively. Cd accumulation in the shoots was significantly lower under the T2 and T3 treatments than under the T1 treatment at 5 and 10 mg kg-1 Cd; however, no significant differences were observed among all treatments at 15 mg kg-1 Cd. These findings indicated that phytoremediation efficiency decreased in response to both salt stress and cation antagonism caused by brackish water under low soil-Cd concentrations; however, this effect was negligible under high soil-Cd concentration. Therefore, brackish water irrigation can be considered for the phytoremediation of soils contaminated with high Cd levels to save freshwater resources.


Assuntos
Cádmio , Poluentes do Solo , Cádmio/análise , Solo , Zea mays , Biodegradação Ambiental , Água , Águas Salinas , Cátions , Poluentes do Solo/análise
15.
Chempluschem ; 89(4): e202300466, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37902417

RESUMO

Structured catalysts are widely used in catalytic oxidation of gaseous pollutants, hot catalysis is usually needed to assist the reaction in the catalytic process. Herein, a Ce-modified manganese oxide octahedral molecular sieves (Ce-OMS-2) structured catalyst supported on foam nickel was prepared through impregnation process. A systematically quantitative testing on the toluene catalytic oxidation effectiveness of this structured catalyst was conducted through catalyst evaluation device, combining a series of characterization methods, such as XRD and SEM, the structure-activity relationship was established. Assisted with electric internal heating and ozone oxidation environments, this structured catalyst exhibits excellent catalytic oxidation performance for oxidative decomposition of toluene even under high humidity conditions. The results showed that the ozone-coupled structured nickel foam catalyst increased the decomposition efficiency of toluene from 25 % (without catalyst and heating) to 55 % (with catalyst and without heating) and the electric internal heating can significantly improve the reactivity and moisture resistance of the structured nickel-foam catalyst, at 90 % RH and 40000 h-1, 50000 ppb O3 and 40 mg/m3 toluene was maintained 100 % catalytic efficiency. The high-efficiency non-precious metal-based electrothermal catalyst prepared herein is expected to have certain enlightenment for the purification of VOCs.

16.
Org Lett ; 25(50): 9041-9046, 2023 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-38088909

RESUMO

An α-diazodifluoroethane sulfonium reagent was developed in this study to undergo [3 + 2] radical cyclization with unactivated alkynes to give the corresponding 3-difluoromethyl pyrazoles under blue light irradiation conditions. The key to the success of this transformation lies in the formation of an electron donor-acceptor (EDA) complex between an electron-deficient α-diazo sulfonium salt and an electron-rich triaryl amine. This study circumvents a major substrate scope limitation in polar cycloaddition reactions of existent diazodifluoroethane reagents.

17.
Biochem J ; 480(24): 2045-2058, 2023 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-38078799

RESUMO

The SLC7A11/xCT cystine and glutamate antiporter has emerged as an attractive target for cancer therapy due to its selective overexpression in multiple cancers and its role in preventing ferroptosis. Utilizing pharmacological and genetic approaches in hepatocellular carcinoma cell lines, we demonstrate that overexpression of SLC7A11 engenders hypersensitivity towards l-selenocystine, a naturally occurring diselenide that bears close structural similarity to l-cystine. We find that the abundance of SLC7A11 positively correlates with sensitivity to l-selenocystine, but surprisingly, not to Erastin, an inhibitor of SLC7A11 activity. Our data indicate that SLC7A11 acts as a transport channel for l-selenocystine, which preferentially incites acute oxidative stress and damage eventuating to cell death in cells that highly express SLC7A11. Hence, our findings raise the prospect of l-selenocystine administration as a novel strategy for targeting cancers that up-regulate SLC7A11 expression.


Assuntos
Cistina , Linhagem Celular Tumoral , Cistina/metabolismo , Regulação para Cima , Sistema y+ de Transporte de Aminoácidos/metabolismo
18.
Inorg Chem ; 62(46): 19006-19014, 2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-37930938

RESUMO

The application of X-ray imaging in military, industrial flaw detection, and medical examination is inseparable from the wide application of scintillator materials. In order to substitute for lead, lower costs, and reduce self-absorption, organic-inorganic hybrid lead-free perovskite scintillators are emerging as a new option. In this work, novel (TEA)2Zr1-xTexCl6 perovskite microcrystals (MCs) were successfully synthesized by a hydrothermal method, with Te4+ doping, which leads to yellow triplet-state self-trapped excitons emission. The emission peak of (TEA)2Zr1-xTexCl6 located at 605 nm under X-ray excitation, which was applied to X-ray imaging, shows a clear wiring structure inside the USB connector. The detection limit (DL) of 820 nGyair/s for (TEA)2Zr0.9Te0.1Cl6 is well below the dose rate corresponding to a standard medical X-ray diagnosis is 5.5 µGyair/s. This work opens up a new path for organic-inorganic hybrid lead-free scintillators.

19.
Adv Sci (Weinh) ; 10(35): e2304194, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37880870

RESUMO

Catalytic asymmetric hydroboration of fluoroalkyl-substituted alkenes is a straightforward approach to access chiral small molecules possessing both fluorine and boron atoms. However, enantioselective hydroboration of fluoroalkyl-substituted alkenes without fluorine elimination has been a long-standing challenge in this field. Herein, a copper-catalyzed hydroboration of difluoroalkyl-substituted internal alkenes with high levels of regio- and enantioselectivities is reported. The native carbonyl directing group, copper hydride system, and bisphosphine ligand play crucial roles in suppressing the undesired fluoride elimination. This atom-economic protocol provides a practical synthetic platform to obtain a wide scope of enantioenriched secondary boronates bearing the difluoromethylene moieties under mild conditions. Synthetic applications including functionalization of biorelevant molecules, versatile functional group interconversions, and preparation of difluoroalkylated Terfenadine derivative are also demonstrated.

20.
Front Pharmacol ; 14: 1231933, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37790813

RESUMO

Background: Traditional Chinese medicine (TCM) effectively improves the survival rate and quality of life of primary liver cancer patients, but high-level evidence is lacking. Patients and methods: Patients were selected from 5 tertiary hospitals in Henan Province, China. Two thousand sixty-seven patients with primary liver cancer were included in the study. The electronic medical records (EMRs) of the patients were collected. Patients who received adjunctive TCM treatment and underwent treatment cumulative time for more than 1 month were classified as the TCM intervention cohort. Patients who did not receive adjunctive TCM treatment or underwent treatment cumulative time for less than 1 month were classified as the non-TCM intervention cohort. The main outcome indicators were the survival rate and overall survival time. The propensity score inverse probability weighting method was used to balance the differences between the groups. Results: The primary cohort comprised 2,067 patients, including 462 patients who received adjunctive TCM treatment and 1,605 patients who did not receive adjunctive TCM treatment. The results of the Kaplan‒Meier survival curve indicated that the survival rate and median survival time of the exposure group before and after propensity score weighting were greater than those of the control group (p < 0.0001). Univariate Cox regression analysis after propensity score weighting showed that adjunctive TCM treatment was an independent protective factor for survival [regression coefficient = -0.215, hazard ratio (HR) = 0.8066, 95% confidence interval (CI) (0.6609-0.9844)]. Conclusion: Adjuvant treatment with TCM has a protective effect on the prognosis of patients with primary liver cancer; it can reduce the mortality and prolong the survival time.

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