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1.
Heliyon ; 10(16): e35936, 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-39224379

RESUMO

Aims: Cerebral ischemic preconditioning is a neuroprotective therapy against cerebral ischemia and ischemia-reperfusion injury. This study aims to demonstrate the alternation of gene expression in exosomes from brain tissue of mice after ischemic preconditioning and their potential functions. Methods: Ten mice were divided into the sham and the cerebral ischemic preconditioning groups. Their brain tissues were harvested, from which the exosomes were extracted. The characteristics and protective effects of exosomes were evaluated. Whole transcriptome sequencing was used to demonstrate the gene expression discrepancy between the exosomes from the two groups of mice brains. Volcano graphs and heatmaps were used to picture the difference in expression quantity of mRNA, lncRNA, and circRNA. Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed to demonstrate the functions of differentially expressed RNAs. Results: Exosomes were successfully extracted, and those from the cerebral ischemic preconditioning group had better protective effects on cells that received oxygen-glucose deprivation and restoration injury. A total of 306 mRNAs and 374 lncRNAs were significantly upregulated, and 320 mRNAs and 405 lncRNAs were significantly downregulated in the preconditioning group. No circRNAs were differentially expressed between the two groups. GO and KEGG pathway analysis indicated that the functions of differentially expressed RNAs were related to both neural protective and injurious effects. Conclusion: The brain-derived exosomes may participate in the neuroprotective effect of cerebral ischemic preconditioning. Thorough research is necessary to investigate exosome functions derived from the ischemic preconditioned brain.

2.
Angew Chem Int Ed Engl ; : e202412735, 2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-39205491

RESUMO

The rapid transport kinetics of divalent magnesium ions are crucial for achieving distinguished performance in aqueous magnesium-ion battery-based energy storage capacitors. However, the strong electrostatic interaction between Mg2+ with double charges and the host material significantly restricts Mg2+ diffusivity. In this study, a new composite material, EDA-Mn2O3, with double-energy storage mechanisms comprising an organic phase (ethylenediamine, EDA) and an inorganic phase (manganese sesquioxide) was successfully synthesized via an organic-inorganic coupling strategy. Inorganic-phase Mn2O3 serves as a scaffold structure, enabling the stable and reversible intercalation/deintercalation of magnesium ions. The organic phase EDA adsorbed onto the surface of Mn2O3 as an elastic matrix, works synergistically with Mn2O3, and utilizes bidentate chelating ligands to capture Mg2+. The robust coordination effect of terminal biprotonic amine in EDA enhances the structural diversity and specific capacity characteristics of the composite material, as further corroborated by density functional theory (DFT) calculations, ex-situ XRD, XPS, and Raman spectroscopy. As expected, an aqueous magnesium ion capacitor with EDA-Mn2O3 serving as the cathode can reach 110.17 Wh/kg. This study aimed to explore the practical application value of organic‒inorganic composite electrodes with double-energy storage mechanisms.

3.
Nanomicro Lett ; 16(1): 277, 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39190236

RESUMO

Significant challenges are posed by the limitations of gas sensing mechanisms for trace-level detection of ammonia (NH3). In this study, we propose to exploit single-atom catalytic activation and targeted adsorption properties to achieve highly sensitive and selective NH3 gas detection. Specifically, Ni single-atom active sites based on N, C coordination (Ni-N-C) were interfacially confined on the surface of two-dimensional (2D) MXene nanosheets (Ni-N-C/Ti3C2Tx), and a fully flexible gas sensor (MNPE-Ni-N-C/Ti3C2Tx) was integrated. The sensor demonstrates a remarkable response value to 5 ppm NH3 (27.3%), excellent selectivity for NH3, and a low theoretical detection limit of 12.1 ppb. Simulation analysis by density functional calculation reveals that the Ni single-atom center with N, C coordination exhibits specific targeted adsorption properties for NH3. Additionally, its catalytic activation effect effectively reduces the Gibbs free energy of the sensing elemental reaction, while its electronic structure promotes the spill-over effect of reactive oxygen species at the gas-solid interface. The sensor has a dual-channel sensing mechanism of both chemical and electronic sensitization, which facilitates efficient electron transfer to the 2D MXene conductive network, resulting in the formation of the NH3 gas molecule sensing signal. Furthermore, the passivation of MXene edge defects by a conjugated hydrogen bond network enhances the long-term stability of MXene-based electrodes under high humidity conditions. This work achieves highly sensitive room-temperature NH3 gas detection based on the catalytic mechanism of Ni single-atom active center with N, C coordination, which provides a novel gas sensing mechanism for room-temperature trace gas detection research.

4.
Nat Commun ; 15(1): 5913, 2024 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-39003260

RESUMO

Traditional catalytic techniques often encounter obstacles in the search for sustainable solutions for converting CO2 into value-added products because of their high energy consumption and expensive catalysts. Here, we introduce a contact-electro-catalysis approach for CO2 reduction reaction, achieving a CO Faradaic efficiency of 96.24%. The contact-electro-catalysis is driven by a triboelectric nanogenerator consisting of electrospun polyvinylidene fluoride loaded with single Cu atoms-anchored polymeric carbon nitride (Cu-PCN) catalysts and quaternized cellulose nanofibers (CNF). Mechanistic investigation reveals that the single Cu atoms on Cu-PCN can effectively enrich electrons during contact electrification, facilitating electron transfer upon their contact with CO2 adsorbed on quaternized CNF. Furthermore, the strong adsorption of CO2 on quaternized CNF allows efficient CO2 capture at low concentrations, thus enabling the CO2 reduction reaction in the ambient air. Compared to the state-of-the-art air-based CO2 reduction technologies, contact-electro-catalysis achieves a superior CO yield of 33 µmol g-1 h-1. This technique provides a solution for reducing airborne CO2 emissions while advancing chemical sustainability strategy.

5.
Gels ; 10(7)2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-39057472

RESUMO

In order to solve the problem of gas channeling during CO2 flooding in low-permeability reservoirs, a novel CO2 responsive gel channeling system was prepared by using carrageenan, branched polyethylene imide and ethylenediamine under laboratory conditions. Based on the Box-Behnken response surface design method, the optimal synthesis concentration of the system was 0.5 wt% carrageenan, 2.5 wt% branchized polyethylenimide and 6.5 wt% ethylenediamine. The micromorphology of the system before and after response was characterized by scanning electron microscopy. The rheology and dehydration rate were tested under different conditions. The channeling performance and enhanced oil recovery effect of the gel system were simulated by a core displacement experiment. The experimental results show that the internal structure of the system changes from a disordered, smooth and loosely separated lamellae structure to a more uniform, complete and orderly three-dimensional network structure after exposure to CO2. The viscosity of the system was similar to aqueous solution before contact with CO2 and showed viscoelastic solid properties after contact with CO2. The experiment employing dehydration rates at different temperatures showed that the internal structure of the gel would change at a high temperature, but the gel system had a certain self-healing ability. The results of the displacement experiment show that the plugging rate of the gel system is stable at 85.32% after CO2 contact, and the recovery rate is increased by 17.06%, which provides an important guide for the development of low-permeability reservoirs.

6.
Neurobiol Dis ; 199: 106594, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39025270

RESUMO

AIMS: Cytoplasmic dynein heavy chain (DYNC1H1) is a multi-subunit protein complex that provides motor force for movement of cargo on microtubules and traffics them back to the soma. In humans, mutations along the DYNC1H1 gene result in intellectual disabilities, cognitive delays, and neurologic and motor deficits. The aim of the study was to generate a mouse model to a newly identified de novo heterozygous DYNC1H1 mutation, within a functional ATPase domain (c9052C > T(P3018S)), identified in a child with motor deficits, and intellectual disabilities. RESULTS: P3018S heterozygous (HET) knockin mice are viable; homozygotes are lethal. Metabolic and EchoMRI™ testing show that HET mice have a higher metabolic rate, are more active, and have less body fat compared to wildtype mice. Neurobehavioral studies show that HET mice perform worse when traversing elevated balance beams, and on the negative geotaxis test. Immunofluorescent staining shows neuronal migration abnormalities in the dorsal and lateral neocortex with heterotopia in layer I. Neuron-subtype specific transcription factors CUX1 and CTGF identified neurons from layers II/III and VI respectively in cortical layer I, and abnormal pyramidal neurons with MAP2+ dendrites projecting downward from the pial surface. CONCLUSION: The HET mice are a good model for the motor deficits seen in the child, and highlights the importance of cytoplasmic dynein in the maintenance of cortical function and dendritic orientation relative to the pial surface. Our results are discussed in the context of other dynein mutant mice and in relation to clinical presentation in humans with DYNC1H1 mutations.


Assuntos
Dineínas do Citoplasma , Mutação , Animais , Dineínas do Citoplasma/genética , Dineínas do Citoplasma/metabolismo , Camundongos , Mutação/genética , Humanos , Encéfalo/metabolismo , Encéfalo/patologia , Modelos Animais de Doenças , Camundongos Transgênicos , Masculino , Deficiência Intelectual/genética , Neurônios/metabolismo , Neurônios/patologia
7.
Chem Asian J ; : e202400199, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38946437

RESUMO

Iron-nitrogen functionalized graphene has emerged as a promising cathode host for rechargeable lithium-sulfur batteries (RLSBs) due to its affordability and enhanced battery performance. To optimize its catalytical efficiency, we propose a novel approach involving coordination engineering. Our investigation spans a plethora of catalysts with varied coordination environments, focusing on elements B, C, N and O. We revealed that Fe-C4 and Fe-B2C2-h are particularly effective for promoting Li2S oxidation, whereas Fe-N4 excels in catalyzing the sulfur reduction reaction (SRR). Importantly, our study identified specific descriptors - namely, the Integrated Crystal Orbital Hamilton Population (ICOHP) and the bond length between Fe and S in Li2S adsorbed state - as the most effective predictive descriptors for Li2S oxidation barriers. Meanwhile, Li2S adsorption energy emerges as a reliable descriptor for assessing the SRR barrier. These identified descriptors are expected to be instrumental in rapidly identifying promising cathode hosts across various metal-centered systems with diverse coordination environments. Our findings not only offer valuable insights into the role of coordination environment, but also present an effective path for rapidly identifying high performance catalysts for RLSBs, enabling the acceleration of advanced RLSBs development.

8.
ACS Appl Mater Interfaces ; 16(31): 41176-41184, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39072613

RESUMO

The process development and optimization of p-type semiconductors and p-channel thin-film transistors (TFTs) are essential for the development of high-performance circuits. In this study, the Br-doped CuI (CuIBr) TFTs are proposed by the solution process to control copper vacancy generation and suppress excess holes formation in p-type CuI films and improve current modulation capabilities for CuI TFTs. The CuIBr films exhibit a uniform surface morphology and good crystalline quality. The on/off current (ION/IOFF) ratio of CuIBr TFTs increased from 103 to 106 with an increase in the Br doping ratio from 0 to 15%. Furthermore, the performance and operational stability of CuIBr TFTs are significantly enhanced by indium tin oxide (ITO) surface charge-transfer doping. The results obtained from the first-principles calculations well explain the electron-doping effect of ITO overlayer in CuIBr TFT. Eventually, the CuIBr TFT with 15% Br content exhibits a high ION/IOFF ratio of 3 × 106 and a high hole field-effect mobility (µFE) of 7.0 cm2 V-1 s-1. The band-like charge transport in CuIBr TFT is confirmed by the temperature-dependent measurement. This study paves the way for the realization of transparent complementary circuits and wearable electronics.

9.
ACS Omega ; 9(17): 18777-18785, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38708220

RESUMO

The solution of wellbore multiphase flow models has an important position in oil-gas field development. However, the solution of multiphase flow models often involves a series of complicated situations such as interphase mass and energy transfer, surface problems, and so on. Foam carrying sand particles in the wellbore is a solid, liquid, and gas three-phase cylinder flow problem. To solve this problem, we developed a computational fluid dynamics-discrete element method model based on the traditional N-S equations to track the streamline of the foam fluid and sand particles in the wellbore. On this basis, we investigated the influence of three factors, i.e., foam and sand properties and wellbore parameters, on the sand carrying rate of foam. The results show that whether the sand mound at the bottom of wells that can be dispersed is mainly affected by the properties of foam. The location of sand deposition in the wellbore and the effectiveness of foam in sand transportation are mainly influenced by the wellbore parameters and sand properties.

10.
Adv Mater ; 36(29): e2401838, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38748700

RESUMO

The advent of 2D ferroelectrics, characterized by their spontaneous polarization states in layer-by-layer domains without the limitation of a finite size effect, brings enormous promise for applications in integrated optoelectronic devices. Comparing with semiconductor/insulator devices, ferroelectric devices show natural advantages such as non-volatility, low energy consumption and high response speed. Several 2D ferroelectric materials have been reported, however, the device implementation particularly for optoelectronic application remains largely hypothetical. Here, the linear electro-optic effect in 2D ferroelectrics is discovered and electrically tunable 2D ferroelectric metalens is demonstrated. The linear electric-field modulation of light is verified in 2D ferroelectric CuInP2S6. The in-plane phase retardation can be continuously tuned by a transverse DC electric field, yielding an effective electro-optic coefficient rc of 20.28 pm V-1. The CuInP2S6 crystal exhibits birefringence with the fast axis oriented along its (010) plane. The 2D ferroelectric Fresnel metalens shows efficacious focusing ability with an electrical modulation efficiency of the focusing exceeding 34%. The theoretical analysis uncovers the origin of the birefringence and unveil its ultralow light absorption across a wide wavelength range in this non-excitonic system. The van der Waals ferroelectrics enable room-temperature electrical modulation of light and offer the freedom of heterogeneous integration with silicon and another material system for highly compact and tunable photonics and metaoptics.

11.
Brain Circ ; 10(1): 67-76, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38655441

RESUMO

PURPOSE: Through three neurocritical care unit (NCCU) surveys in China, we tried to understand the development status of neurocritical care and clarify its future development. METHODS: Using a cross-sectional survey method and self-report questionnaires, the number and quality of NCCUs were investigated through three steps: administering the questionnaire, sorting the survey data, and analyzing the survey data. RESULTS: At the second and third surveys, the number of NCCUs (76/112/206) increased by 47% and 84%, respectively. The NCCUs were located in tertiary grade A hospitals or teaching hospitals (65/100/181) in most provinces (24/28/29). The numbers of full-time doctors (359/668/1337) and full-time nurses (904/1623/207) in the NCCUs increased, but the doctor-bed ratio and nurse-bed ratio were still insufficient (0.4:1 and 1.3:1). CONCLUSION: In the past 20 years, the growth rate of NCCUs in China has accelerated, while the allocation of medical staff has been insufficient. Although most NCCU hospital bed facilities and instruments and equipment tend to be adequate, there are obvious defects in some aspects of NCCUs.

12.
ACS Appl Mater Interfaces ; 16(17): 22166-22176, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38648115

RESUMO

We propose an atomically resolved approach to capture the spatial variations of the Schottky barrier height (SBH) at metal-semiconductor heterojunctions. This proposed scheme, based on atom-specific partial density of states (PDOS) calculations, further enables calculation of the effective SBH that aligns with conductance measurements. We apply this approach to study the variations of SBH at MoS2@Au heterojunctions, in which MoS2 contains conducting and semiconducting grain boundaries (GBs). Our results reveal that there are significant variations in SBH at atoms in the defected heterojunctions. Of particular interest is the fact that the SBH in some areas with extended defects approaches zero, indicating Ohmic contact. One important implication of this finding is that the effective SBH should be intrinsically dependent on the defect density and character. Remarkably, the obtained effective SBH values demonstrate good agreement with existing experimental measurements. Thus, the present study addresses two long-standing challenges associated with SBH in MoS2-metal heterojunctions: the wide variation in experimentally measured SBH values at MoS2@metal heterojunctions and the large discrepancy between density-functional-theory-predicted and experimentally measured SBH values. Our proposed approach points out a valuable pathway for understanding and manipulating SBHs at metal-semiconductor heterojunctions.

13.
Nano Lett ; 24(17): 5206-5213, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38647212

RESUMO

Single Atoms Catalysts (SACs) have emerged as a class of highly promising heterogeneous catalysts, where the traditional bottom-up synthesis approaches often encounter considerable challenges in relation to aggregation issues and poor stability. Consequently, achieving densely dispersed atomic species in a reliable and efficient manner remains a key focus in the field. Herein, we report a new facile electrochemical knock-down strategy for the formation of SACs, whereby the metal Zn clusters are transformed into single atoms. While a defect-rich substrate plays a pivotal role in capturing and stabilizing isolated Zn atoms, the feasibility of this novel strategy is demonstrated through a comprehensive investigation, combining experimental and theoretical studies. Furthermore, when studied in exploring for potential applications, the material prepared shows a remarkable improvement of 58.21% for the Li+ storage and delivers a capacity over 300 Wh kg-1 after 500 cycles upon the transformation of Zn clusters into single atoms.

14.
Langmuir ; 40(15): 7843-7859, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38557084

RESUMO

Two-dimensional materials have shown immense promise for gas-sensing applications due to their remarkable surface-to-volume ratios and tunable chemical properties. However, despite their potential, the utilization of ReSe2 as a gas-sensing material for nitrogen-containing molecules, including NO2, NO, and NH3, has remained unexplored. The choice of doping atoms in ReSe2 plays a pivotal role in enhancing the gas adsorption and gas-sensing capabilities. Herein, the adsorption properties of nitrogen-containing gas molecules on metal and non-metal single-atom (Au, Pt, Ni, P, and S)-doped ReSe2 monolayers have been evaluated systematically via ab initio calculations based on density functional theory. The findings strongly suggest that intrinsic ReSe2 has better selectivity toward NO2 than toward NO and NH3. Moreover, our results provide compelling evidence that all of the dopants, with the exception of S, significantly enhance both the adsorption strength and charge transfer between ReSe2 and the investigated molecules. Notably, P-decorated ReSe2 showed the highest adsorption energy for NO2 and NO (-1.93 and -1.52 eV, respectively) with charge transfer above 0.5e, while Ni-decorated ReSe2 exhibited the highest adsorption energy for NH3 (-0.76 eV). In addition, on the basis of transition theory, we found that only Au-ReSe2 and Ni-ReSe2 can serve as reusable chemiresisitve gas sensors for reliable detection of NO and NH3, respectively. Hence, our findings indicate that gas-sensing applications can be significantly improved by utilizing a single-atom-doped ReSe2 monolayer.

15.
Neurocrit Care ; 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38480608

RESUMO

BACKGROUND: In this study, we aimed to investigate the risk factors and impact of poststroke pneumonia (PSP) on mortality and functional outcome in patients with acute ischemic stroke (AIS) after endovascular thrombectomy (EVT). METHODS: This was a post hoc analysis of a prospective randomized trial (Direct intraarterial thrombectomy in order to revascularize AIS patients with large-vessel occlusion efficiently in Chinese tertiary hospitals: a multicenter randomized clinical trial). Patients with AIS who completed EVT were evaluated for the occurrence of PSP during the hospitalization period and their modified Rankin Scale (mRS) scores at 90 days after AIS. Logistic regression analysis was conducted to investigate the independent predictors of PSP. Propensity score matching was conducted for the PSP and non-PSP groups by using the covariates resulting from the logistic regression analysis. The associations between PSP and outcomes were analyzed. The outcomes included 90-day poor functional outcome (mRS scores > 2), 90-day mortality, and early 2-week mortality. RESULTS: A total of 639 patients were enrolled, of whom 29.58% (189) developed PSP. Logistic regression analysis revealed that history of chronic heart failure (unadjusted odds ratio [OR] 2.011, 95% confidence interval [CI] 1.026-3.941; P = 0.042), prethrombectomy reperfusion on initial digital subtraction angiography (OR 0.394, 95% CI 0.161-0.964; P = 0.041), creatinine levels at admission (OR 1.008, 95% CI 1.000-1.016; P = 0.049), and National Institutes of Health Stroke Scale at 24 h (OR 1.023, 95% CI 1.007-1.039; P = 0.004) were independent risk factors for PSP. With propensity scoring matching, poor functional outcome (mRS > 2) was more common in patients with PSP than in patients without PSP (81.03% vs. 71.83%, P = 0.043) at 90 days after EVT. The early 2-week mortality of patients with PSP was lower (5.74% vs. 12.07%, P = 0.038). But there was no statistically significant difference in 90-day mortality between the PSP group and non-PSP group (22.41% vs. 14.94%, P = 0.074). The survivorship curve also shows no statistical significance (P = 0.088) between the two groups. CONCLUSIONS: Nearly one third of patients with AIS and EVT developed PSP. Heart failure, higher creatinine levels, prethrombectomy reperfusion, and National Institutes of Health Stroke Scale at 24 h were associated with PSP in these patients. PSP was associated with poor 90-day functional outcomes in patients with AIS treated with EVT.

16.
Int J Biol Macromol ; 265(Pt 2): 131165, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38547941

RESUMO

Garlic is a common vegetable and spice in people's daily diets, in which garlic polysaccharide (GP) is one of the most important active components with a variety of benefits, such as antioxidant, immune-enhancing, anti-inflammatory, liver-protective and bowel-regulating properties. >20 types of GPs, mainly crude polysaccharides, have been identified. However, the exact chemical composition of GPs or the mechanism underlying their pharmacological activity is still not fully understood. The extraction and purification methods of GPs are compared in this review while providing detailed information on their structural features, identification methods, major biological activities, mechanisms of actions, structural modifications, structure-activity relationships as well as potential applications. Finally, the limitations of GP research and future issues that need to be addressed are discussed in this review. GPs are widely recognized as substances with great potential in the pharmaceutical and food industries. Therefore, this review aims to provide a comprehensive summary of the latest research progresses in the field of GPs, together with scientific insights and a theoretical support for the development of GPs in research and industrialization.


Assuntos
Produtos Biológicos , Alho , Humanos , Antioxidantes/farmacologia , Verduras , Relação Estrutura-Atividade , Polissacarídeos/farmacologia
17.
Ground Water ; 62(5): 778-794, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38517231

RESUMO

Tianjin, a coastal metropolis in north China, has grappled with land subsidence for nearly a century. Yet, emerging evidence suggests a notable decrease in subsidence rates across Tianjin since 2019. This trend is primarily attributed to the importation of surface water from the Yangtze River system via the South-to-North Water Diversion Project, initiated in December 2014. Utilizing Sentinel-1A Interferometric Synthetic Aperture Radar (InSAR) data (2014-2023), this study reveals that one-third of the Tianjin plain has either halted subsidence or experienced land rebound. As a result, the deep aquifer system (~-200 to -450 m) beneath one third of the Tianjin plain has completed a consolidation cycle, leading to the establishment of new, locally specific preconsolidation heads. The identification of the newly established preconsolidation head seeks to answer a crucial question: How can we prevent the reoccurrence of subsidence in areas where it has already ceased? In essence, subsidence will stop when the local hydraulic head elevates to the new preconsolidation head (NPCH), and permanent subsidence will not be reinitiated as long as hydraulic head remains above the NPCH. The difference of the depth between current hydraulic head and the NPCH defines the safe pumping buffer (SPB). This study outlines detailed methods for identifying the NPCHs in the deep aquifer system from long-term InSAR and groundwater-level datasets. Determining NPCHs and ascertaining SPBs are crucial for estimating how much groundwater can be safely extracted without inducing permanent subsidence, and for developing sustainable strategies for long-term groundwater management and conservation.


Assuntos
Água Subterrânea , Movimentos da Água , China , Rios , Monitoramento Ambiental/métodos , Hidrologia
18.
Brain ; 147(5): 1784-1798, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38387080

RESUMO

The Huntington's disease mutation is a CAG repeat expansion in the huntingtin gene that results in an expanded polyglutamine tract in the huntingtin protein. The CAG repeat is unstable and expansions of hundreds of CAGs have been detected in Huntington's disease post-mortem brains. The age of disease onset can be predicted partially from the length of the CAG repeat as measured in blood. Onset age is also determined by genetic modifiers, which in six cases involve variation in DNA mismatch repair pathways genes. Knocking-out specific mismatch repair genes in mouse models of Huntington's disease prevents somatic CAG repeat expansion. Taken together, these results have led to the hypothesis that somatic CAG repeat expansion in Huntington's disease brains is required for pathogenesis. Therefore, the pathogenic repeat threshold in brain is longer than (CAG)40, as measured in blood, and is currently unknown. The mismatch repair gene MSH3 has become a major focus for therapeutic development, as unlike other mismatch repair genes, nullizygosity for MSH3 does not cause malignancies associated with mismatch repair deficiency. Potential treatments targeting MSH3 currently under development include gene therapy, biologics and small molecules, which will be assessed for efficacy in mouse models of Huntington's disease. The zQ175 knock-in model carries a mutation of approximately (CAG)185 and develops early molecular and pathological phenotypes that have been extensively characterized. Therefore, we crossed the mutant huntingtin allele onto heterozygous and homozygous Msh3 knockout backgrounds to determine the maximum benefit of targeting Msh3 in this model. Ablation of Msh3 prevented somatic expansion throughout the brain and periphery, and reduction of Msh3 by 50% decreased the rate of expansion. This had no effect on the deposition of huntingtin aggregation in the nuclei of striatal neurons, nor on the dysregulated striatal transcriptional profile. This contrasts with ablating Msh3 in knock-in models with shorter CAG repeat expansions. Therefore, further expansion of a (CAG)185 repeat in striatal neurons does not accelerate the onset of molecular and neuropathological phenotypes. It is striking that highly expanded CAG repeats of a similar size in humans cause disease onset before 2 years of age, indicating that somatic CAG repeat expansion in the brain is not required for pathogenesis. Given that the trajectory for somatic CAG expansion in the brains of Huntington's disease mutation carriers is unknown, our study underlines the importance of administering treatments targeting somatic instability as early as possible.


Assuntos
Proteína Huntingtina , Doença de Huntington , Expansão das Repetições de Trinucleotídeos , Doença de Huntington/genética , Doença de Huntington/terapia , Animais , Humanos , Expansão das Repetições de Trinucleotídeos/genética , Camundongos , Proteína Huntingtina/genética , Proteína 3 Homóloga a MutS/genética , Modelos Animais de Doenças , Proteínas do Tecido Nervoso/genética , Encéfalo/patologia , Encéfalo/metabolismo
19.
AJNR Am J Neuroradiol ; 45(3): 296-301, 2024 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-38388688

RESUMO

BACKGROUND AND PURPOSE: Whether thrombus burden in acute ischemic stroke modify the effect of intravenous thrombolysis (IVT) before mechanical thrombectomy (MT) remains uncertain. We aim to investigate the treatment effect of stratified clot burden score (CBS) on the efficacy and safety of direct versus bridging MT. MATERIALS AND METHODS: This is an exploratory subgroup analysis of a randomized trial evaluating the effect of CBS on clinical outcome in the DIRECT-MT trial. CBS was divided into 3 groups (0-3, 4-6, and 7-10) based on preoperative CTA, where higher scores indicated a lower clot burden. We report the adjusted common odds ratio for a shift toward better outcomes on the mRS after thrombectomy alone compared with combination treatment by stratified CBS groups. RESULTS: No modification effect of mRS distribution was observed by CBS subgroups (CBS 0-3: adjusted common ratio odds 1.519 [95% CI, 0.928-2.486]; 4-6: 0.924 [0.635-1.345]; 7-10: 1.040 [0.481-2.247]). Patients with CBS 4-6 had a higher rate of early reperfusion (adjusted OR (aOR), 0.3 [95% CI, 0.1-0.9]), final reperfusion (aOR 0.5 [95% CI, 0.3-0.9]), and fewer thrombectomy attempts (aOR 0.4 [95% CI, 0.1-0.7]). Patients with CBS 7-10 had a higher rate of asymptomatic intracranial hemorrhage (14.9% versus 36.8%, P = .0197) for bridging MT. No significant difference was observed in other safety outcomes by trichotomized CBS. CONCLUSIONS: The subgroup analysis of DIRECT-MT suggested that thrombus burden did not alter the treatment effect of IVT before MT on functional outcomes in CBS subgroups.


Assuntos
Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Trombose , Humanos , Ativador de Plasminogênio Tecidual/uso terapêutico , Acidente Vascular Cerebral/cirurgia , Terapia Trombolítica , Isquemia Encefálica/terapia , Resultado do Tratamento , Trombectomia , Trombose/tratamento farmacológico , Fibrinolíticos/uso terapêutico
20.
Cerebrovasc Dis ; 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38377964

RESUMO

BACKGROUND: Although guidelines recommend a target blood pressure 185-180/105-110 mmHg after mechanical thrombectomy for acute ischemic stroke (AIS), there is limited randomized evidence to support this level. We surveyed candidate institutions about the approach to blood pressure management in this patient group in preparation for inviting them to participate in the Enhanced Blood Pressure Control after Endovascular Thrombectomy for the Acute Ischemic Stroke Trial (ENCHANTED2/MT). METHODS: Physicians from a professional network of institutions that met mechanical thrombectomy qualification requirements were invited to participate in an online questionnaire covering basic clinical information as well as questions on blood pressure management. RESULTS: We invited 88 sites to participate with 44 (50%) ultimately joining the trial, and a total of 88 physicians finished the survey. The median number of annual mechanical thrombectomy cases performed per site was 89 [IQR 65-150]. Only 38 (43%) institutions strictly adhere to guidelines when managing the blood pressure of mechanical thrombectomy patients. The most popular blood pressure target for reperfusion patients was 140-160 mmHg (n=47, 53%), and <120 mmHg (n=28, 32%). Fewer hospital stroke beds (40 [21-57] vs. 60 [39-110], p = 0.01) and lower proportion of elevated blood pressure after mechanical thrombectomy (25% [10%-50%] vs. 50% [20%-70%], p = 0.02) were related to a more aggressive blood pressure target (<120 mmHg). Urapidil (n=82, 93%) and calcium channel blockers (CCBs) (n = 87, 99%), were the most widely used antihypertensive drugs, respectively. CONCLUSIONS: According to the survey, unstandardized blood pressure management protocols are performed in mechanical thrombectomy patients at institutions across China, which is different from prior survey from another country. More high-quality studies are needed to guide clinical practice.

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