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2.
Artículo en Inglés | MEDLINE | ID: mdl-39441520

RESUMEN

OPINION STATEMENT: Gastrointestinal stromal tumor (GIST) is characterized by well-defined oncogenes. Despite the significant improvement in treatment outcomes with adjuvant imatinib therapy for patients, drug resistance remains a major challenge for GIST therapy. This review focuses on the mechanisms contributing to drug resistance phenotype in GIST, such as primary imatinib-resistant mutants, secondary mutations, non-covalent binding of TKI to its target, tumor heterogeneity, re-activation of pro-survival/proliferation pathways through non-KIT/PDGFRA kinases, and loss of therapeutic targets in wild-type GIST. Corresponding suggestions are proposed to overcome drug-resistance phenotype of GIST. This review also summarizes the suitability of currently approved TKIs on different KIT/PDGFRA mutations and updates related clinical trials. Recent potent drugs and emerging strategies against advanced GISTs in clinical trials are presented. Additionally, metabolic intervention offers a new avenue for clinical management in GIST. A landscape of metabolism in GIST and metabolic changes under imatinib treatment are summarized based on currently published data. The OXPHOS pathway is a promising therapeutic target in combination with TKI against sensitive KIT/PDGFRA mutants. Comprehensive understanding of the above resistance mechanisms, experimental drugs/strategies and metabolic changes is critical to implement the proper therapy strategy and improve the clinical therapy outcomes for GIST.

3.
Angew Chem Int Ed Engl ; : e202416402, 2024 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-39311550

RESUMEN

Recently, Ru single atoms supported on carbon nanomaterials have demonstrated ultrahigh activity for acid hydrogen evolution reaction (HER), however their neutral HER activity remains low due to the sluggish kinetics for both the water dissociation step to generate H* intermediates and subsequent H* recombination in neutral electrolytes. Here, we synthesize ordered low-coordinated Ru atom arrays confined in Mn oxides (i.e., Li4Mn5O12) for concurrently boosting the water dissociation and H* recombination, thus achieving a 6-fold HER activity enhancement than commercial Pt/C in neutral media. Control experiments indicate that low-coordinated Ru atoms with strong affinity to oxygen atoms of water molecules facilitate the water dissociation to rapidly generate H*. More importantly, both electrochemical and theoretic results uncover that the array-like structure allows the activation of two water molecules on two adjacent Ru atoms for enabling direct H*-H* recombination via the Tafel step, while isolated Ru atoms can only activate water one by one for recombining H* via the sluggish Heyrovsky step. Clearly, this work paves new avenues to boosting the electrocatalytic activity by constructing ordered metal atoms assembles with controllable coordination environments.

4.
Aesthetic Plast Surg ; 2024 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-39340681

RESUMEN

BACKGROUND: Autologous fat grafting is widely used in plastic surgery. However, its main limitation is the low survival rate of fat grafts after transplantation. Transplantation of single adipocytes in combination with adipose-derived stem cells (ADSCs) could largely preserve the activity of the fat and improve graft survival. OBJECTIVE: To verify the long-term survival rate of single adipocyte graft in vivo and its viable fat morphology for future fat grafting. METHODS: Healthy adipose tissue was harvested and disassociated using fat dissociation solution, the Single-cell Suspension Preparation System (SSPS) was used to obtain a mixture of single adipocytes, ADSCs and stromal vascular fraction (SVF), and the structure of single adipocytes was verified by cell mask red and DAPI double staining. Nine male Balb/c nude mice were used, and three different graft volumes were established (0.05, 0.1 and 0.2 ml). For each mouse, four sites were selected for transplantation, one for macrofat and the other three for single adipocytes, and different transplant volumes 30, 60 and 90 days after transplantation. In each period, 3 mice were selected to measure the volume of fat graft. RESULTS: Double staining with cell mask red and DAPI confirmed that the nucleus was identified intracellularly, which also indicated that the adipocytes in the single-cell suspension were structurally complete. When evaluating the transplantation, the groups with a volume of 0.05 ml and 0.2 ml performed better in the single-cell fat group in all transplantation periods, the group with a volume of 0.1 ml performed better in the single-cell group in the 30- and 60-day transplantation, and the differences were significant (P<0.05). CONCLUSION: In this study, the SSPS was used to obtain a new transplant material containing single adipocytes and ADSCs by enzymatic hydrolysis of adipose tissue and converted into single cells. It effectively improved the survival rate of fat grafting and the long-term effect of transplantation. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

5.
Nutr J ; 23(1): 98, 2024 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-39175065

RESUMEN

BACKGROUND: Amino acids are crucial for nutrition and metabolism, regulating metabolic pathways and activities vital to organismal health and stability. Glycine and histidine act as potent antioxidants and anti-inflammatory agents; however, limited knowledge exists regarding the associations between these amino acids and hyperlipidemia and hypertension. The purpose of this study is to investigate the relationship between dietary glycine and histidine, and hyperlipidemia and hypertension. METHODS: This population-based cross-sectional study evaluated the influence of dietary glycine and histidine, as well as their combined effect, on hyperlipidemia and hypertension in Chinese adults participating in the Nutrition Health Atlas Project (NHAP). General characteristics were acquired using a verified Internet-based Dietary Questionnaire for the Chinese. Binary logistic regression, along with gender, age groups, and median energy intake subgroup analyses, was employed to investigate the associations between dietary glycine and histidine and hyperlipidemia and hypertension. A sensitivity analysis was conducted to assess the impact of excluding individuals who smoke and consume alcohol on the results. RESULTS: Based on the study's findings, 418 out of 1091 cases had hyperlipidemia, whereas 673 had hypertension. A significant inverse relationship was found between dietary glycine, histidine, and glycine + histidine and hyperlipidemia and hypertension. Compared with the 1st and 2nd tertiles, the multivariable-adjusted odd ratios (ORs) (95% confidence intervals) (CIs) of the 3rd tertile of dietary glycine for hyperlipidemia and hypertension were 0.64 (0.49-0.84) (p < 0.01) and 0.70 (0.56-0.88) (p < 0.001); histidine was 0.63 (0.49-0.82) (p < 0.01) and 0.80 (0.64-0.99) (p < 0.01); and glycine + histidine was 0.64 (0.49-0.83) (p < 0.01) and 0.74 (0.59-0.92) (p < 0.001), respectively. High glycine and high histidine (HGHH) intake were negatively associated with hyperlipidemia and hypertension OR (95% CIs) were: 0.71 (0.58-0.88) (p < 0.01) and 0.73 (0.61-0.87) (p < 0.01), respectively. CONCLUSIONS: Dietary glycine and histidine, as well as their HGHH group, revealed an inverse relationship with hyperlipidemia and hypertension. Further investigations are needed to validate these findings.


Asunto(s)
Dieta , Glicina , Histidina , Hiperlipidemias , Hipertensión , Humanos , Glicina/administración & dosificación , Hipertensión/dietoterapia , Masculino , Femenino , Estudios Transversales , Hiperlipidemias/dietoterapia , Persona de Mediana Edad , Adulto , Dieta/métodos , Dieta/estadística & datos numéricos , China , Anciano , Modelos Logísticos
6.
Int Immunopharmacol ; 139: 112714, 2024 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-39068751

RESUMEN

BACKGROUND: Ischemic stroke is one of the leading causes of chronic disability worldwide, and stroke-induced heart damage can lead to death. According to research, patients with a variety of brain disease have good clinical results after vagus nerve stimulation (VNS). After ischemic stroke, mast cells (MCs) degranulate and release a large number of mediators, which may cause systemic inflammation. Chymase secreted by MCs can increase the levels of pathological angiotensin II (AngⅡ), which plays a crucial role in the deterioration of heart disease. Our goal was to develop a minimally invasive, targeted, and convenient VNS approach to assess the impact of VNS and to clarify the relationship between VNS and MCs in the prognosis of patients with myocardial atrophy after acute ischemic stroke. METHODS: In this study, we verified the role of VNS in the treatment of myocardial atrophy after stroke and its molecular mechanism using a rat model of middle cerebral artery occlusion (MCAO/r). Behavioral studies were assessed using neurobehavioral deficit scores. Enzyme-linked immunosorbent assays, immunofluorescence staining, Western blotting and qRT-PCR were used to analyze the expression levels of myocardial atrophy, MC and inflammatory markers in rat hearts. RESULTS: VNS improved myocardial atrophy in MCAO/r rats, inhibited MC activation, reduced the expression of chymase and AngⅡ, and inhibited the expression of proinflammatory factors. The chymase activator C48/80 reversed these effects of VNS. Chymase activation inhibited the effect of VNS on myocardial atrophy in MCAO/r rats, increased AngⅡ expression and aggravated inflammation and autophagy. The myocardial atrophy of MCAO/r rats was improved after chymase inhibition, and AngⅡ expression, inflammation and autophagy were reduced. Our results suggest that VNS may reduce the expression of chymase and AngⅡ by inhibiting MC activation, thereby improving myocardial atrophy and reducing inflammation and autophagy in MCAO/r rats. Inhibition of MC activation may be an effective strategy for treating myocardial atrophy after stroke. CONCLUSIONS: VNS inhibits MC activation and reduces the expression of chymase and AngII, thereby alleviating myocardial atrophy, inflammation and autophagy after stroke.


Asunto(s)
Quimasas , Infarto de la Arteria Cerebral Media , Accidente Cerebrovascular Isquémico , Mastocitos , Ratas Sprague-Dawley , Estimulación del Nervio Vago , Animales , Mastocitos/inmunología , Masculino , Accidente Cerebrovascular Isquémico/terapia , Accidente Cerebrovascular Isquémico/inmunología , Accidente Cerebrovascular Isquémico/patología , Ratas , Quimasas/metabolismo , Infarto de la Arteria Cerebral Media/terapia , Infarto de la Arteria Cerebral Media/inmunología , Miocardio/patología , Miocardio/inmunología , Atrofia , Modelos Animales de Enfermedad , Angiotensina II/metabolismo
7.
Spectrochim Acta A Mol Biomol Spectrosc ; 322: 124798, 2024 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-39008931

RESUMEN

We propose a novel strategy for tailoring the structure of fluorescent molecules to achieve emission at the tail end of the NIR-II window. The favorable spectroscopic properties and low cytotoxicity of YNs make them powerful tools for bioimaging. Notably, YN-4 exhibits a brightness 2.5 times greater than YN-3, 6 times that of IR-783, and 5 times that of ICG. This enhanced brightness enabled high-resolution imaging of mouse thoracic and abdominal cavities, tumor vasculature, and real-time monitoring of gastrointestinal motility using YN-4. Furthermore, covalent grafting of glucose onto the YN-Glu scaffold significantly improved tumor-targeting capability and facilitated tracking of glucose metabolism. This work aims to extend the application of fluorescent molecule imaging beyond the NIR-IIa window.


Asunto(s)
Colorantes Fluorescentes , Indoles , Animales , Ratones , Indoles/química , Colorantes Fluorescentes/química , Humanos , Espectroscopía Infrarroja Corta/métodos , Imagen Óptica , Carbocianinas/química , Línea Celular Tumoral , Glucosa/metabolismo , Glucosa/química
8.
Mol Aspects Med ; 98: 101280, 2024 08.
Artículo en Inglés | MEDLINE | ID: mdl-38870717

RESUMEN

Although cancer diagnosis and treatment have rapidly advanced in recent decades, urological malignancies, which have high morbidity and mortality rates, are among the most difficult diseases to treat. The Hippo signaling is an evolutionarily conserved pathway in organ size control and tissue homeostasis maintenance. Its downstream effectors, Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ), are key modulators of numerous physiological and pathological processes. Recent work clearly indicates that Hippo signaling is frequently altered in human urological malignancies. In this review, we discuss the disparate viewpoints on the upstream regulators of YAP/TAZ and their downstream targets and systematically summarize the biological implications. More importantly, we highlight the molecular mechanisms involved in Hippo-YAP signaling to improve our understanding of its role in every stage of prostate cancer, bladder cancer and kidney cancer progression. A better understanding of the biological outcomes of YAP/TAZ modulation will contribute to the establishment of future therapeutic approaches.


Asunto(s)
Vía de Señalización Hippo , Proteínas Serina-Treonina Quinasas , Transducción de Señal , Factores de Transcripción , Humanos , Proteínas Serina-Treonina Quinasas/metabolismo , Factores de Transcripción/metabolismo , Neoplasias Urológicas/metabolismo , Neoplasias Urológicas/etiología , Neoplasias Urológicas/patología , Proteínas Señalizadoras YAP/metabolismo , Animales , Proteínas Coactivadoras Transcripcionales con Motivo de Unión a PDZ/metabolismo , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Regulación Neoplásica de la Expresión Génica , Neoplasias de la Vejiga Urinaria/metabolismo , Neoplasias de la Vejiga Urinaria/patología , Neoplasias de la Vejiga Urinaria/genética , Masculino
9.
Artículo en Inglés | MEDLINE | ID: mdl-38913411

RESUMEN

The relationship between genetic alterations in mitochondrial DNA (mtDNA) and progressive motility (PR) and rapid progressive motility (grade A) of ejaculated human spermatozoa remains unclear. In this study, we explored the association between human mtDNA genotype and sperm PR and grade A by analyzing mtDNA copy number, loci, haplogroup, rearrangement, deletions, and duplications and sperm motility parameters. Human sperm mtDNA copy number, loci and haplogroups were not associated with human sperm motility PR or A grade. However, the cumulative frequency of human sperm mtDNA rearrangements (including deletions and duplications) in participants with high PR and grade A ratio was higher than in participants with low PR and grade A ratio. Additional studies are needed to understand the relationship between mtDNA genotypes, including deletions and duplications, and human sperm motility.

10.
Behav Sci (Basel) ; 14(5)2024 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-38785861

RESUMEN

Second language (L2) teachers' emotions can influence their well-being and students' performance. However, most of the existing studies have focused on the role of individual factors in affecting L2 teachers' emotions, while leaving environmental factors underexplored. To fill this gap, this study aimed to examine how the four dimensions of a supportive work environment (SWE) (perceived climate, PC; supervisory relationship, SR; peer group interaction, PGI; and perceived organization support, POS) relate to L2 teachers' emotions (enjoyment, anxiety, pride, and anger). A sample of 406 Chinese L2 teachers completed two valid scales to measure their SWE and emotions. The data were analyzed by Partial Least Squares-Structural Equation Modeling (SEM) using Smart PLS 3 software. The results showed that (1) PC, PGI, and POS had a positive and significant effect on enjoyment, while SR had no significant effect; (2) PGI and POS had a negative and significant effect on anxiety, while PC and SR had no significant effect; (3) PGI had a positive and significant effect on pride, while the other three dimensions had no significant effect; and (4) POS had a negative and significant effect on anger, while the other three dimensions had no significant effect. The study concludes with some implications for L2 teachers' education.

11.
ACS Omega ; 9(18): 20253-20262, 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38737029

RESUMEN

This work from first-principles insight uses a MoS2-WS2 in-plane heterostructure as a potential sensing material for detection of CO and C2H2, two typical dissolved gases in oil-immersed transformers, in order to evaluate the operation status. The adsorption performance of the MoS2-WS2 heterostructure upon two gas species is assessed via three adsorption sites and compared with isolated MoS2 and WS2. Results indicate that MoS2-WS2 performs with a much stronger binding force and charge-transfer for adsorptions of CO and C2H2 in comparison to the isolated counterpart, which gives rise to more obvious deformation in the electronic property of MoS2-WS2 as well as a much larger resistance-based sensing response. The recovery time of MoS2-WS2 for desorption of CO and C2H2 molecules is also appropriate to allow the reusability of such a sensor. The findings in this work uncover the admirable sensing potential of transition metal dichalcogenides (TMDs)-based heterostructures upon oil dissolved gases, which opens up a new way to explore novel 2D nanomaterials as resistive gas sensors for dissolved gas analysis in electrical oil-immersed transformers.

12.
Int Immunopharmacol ; 132: 112030, 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38603861

RESUMEN

Mast cells (MCs) play a significant role in various diseases, and their activation and degranulation can trigger inflammatory responses and barrier damage. Several studies have indicated that vagus nerve stimulation (VNS) exerts ameliorates neurological injury, and regulates gut MC degranulation. However, there is limited research on the modulatory effect of VNS on MCs in both the gut and brain in brain ischemia-reperfusion (I/R) injury in this process. We aim to develop a minimally invasive, targeted and convenient VNS approach to assess the impact of VNS and to clarify the relationship between VNS and MCs on the prognosis of acute ischemic stroke. We utilized middle cerebral artery occlusion/reperfusion (MCAO/r) to induce brain I/R injury. After the experiment, the motor function and neurofunctional impairments of the rats were detected, and the gastrointestinal function, blood-brain barrier (BBB) and intestinal barrier damage, and systemic and local inflammation were evaluated by Nissl, TTC staining, Evans blue, immunofluorescence staining, transmission electron microscopy, western blot assays, ELISA, and fecal 16S rRNA sequencing methods. Our research confirmed that our minimally invasive VNS method is a novel approach for stimulating the vagus nerve. VNS alleviated motor deficits and gastrointestinal dysfunction while also suppressing intestinal and neuroinflammation. Additionally, VNS ameliorated gut microbiota dysbiosis in rats. Furthermore, our analysis indicated that VNS reduces chymase secretion by modulating MCs degranulation and improves intestinal and BBB damage. Our results showed that VNS treatment can alleviate the damage of BBB and colonic barrier after cerebral I/R by modulating mast cell degranulation, and alleviates systemic inflammatory responses.


Asunto(s)
Barrera Hematoencefálica , Eje Cerebro-Intestino , Degranulación de la Célula , Microbioma Gastrointestinal , Accidente Cerebrovascular Isquémico , Mastocitos , Ratas Sprague-Dawley , Daño por Reperfusión , Estimulación del Nervio Vago , Animales , Mastocitos/inmunología , Estimulación del Nervio Vago/métodos , Masculino , Ratas , Daño por Reperfusión/terapia , Daño por Reperfusión/inmunología , Accidente Cerebrovascular Isquémico/terapia , Eje Cerebro-Intestino/fisiología , Infarto de la Arteria Cerebral Media/terapia , Modelos Animales de Enfermedad , Isquemia Encefálica/terapia , Isquemia Encefálica/inmunología
13.
Sci Data ; 11(1): 318, 2024 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-38538648

RESUMEN

Extrachromosomal circular DNA (eccDNA) refers to a distinct class of circular DNA molecules that exist independently from linear chromosomal DNA. Extensive evidence has firmly established the significant involvement of eccDNA in cancer initiation, progression, and evolutionary processes. However, the relationship between eccDNA and brain aging remains elusive. Here, we employed extrachromosomal circular DNA sequencing (Circle-seq) to generate a comprehensive dataset of eccDNA from six brain structures of both young and naturally-aged mice, including the olfactory bulb, medial prefrontal cortex, nucleus accumbens, caudate putamen, hippocampus, and cerebellum. Furthermore, through database annotation, we characterized the properties of mouse brain eccDNA, thereby gaining insights into the potential functions of eccDNA in the mouse brain. In conclusion, our study addresses a previously unexplored area by providing a comprehensive molecular characterization of eccDNA in brain tissues. The data presented in the study can be used as a fundamental resource to associate the molecular phenotypes of eccDNA with brain aging and gain deep insights into the biological role of eccDNA in mammalian brain aging.


Asunto(s)
Encéfalo , ADN Circular , Animales , Ratones , ADN Circular/genética , Envejecimiento/genética
14.
China CDC Wkly ; 6(9): 168-172, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38495593

RESUMEN

Introduction: The purpose of this study is to examine the potential causal relationship between levels of circulating glycine and coronary artery disease (CAD) using a two-step Mendelian randomization (MR) analysis. Methods: We analyzed data from genome-wide association studies (GWAS) conducted on European and East Asian populations. To assess the causal effects of circulating glycine levels on the risk of CAD. We used the inverse-variance weighting (IVW), weighted median (WM), MR-Egger, and Mendelian Randomization Pleiotropy RESidual Sum and Outlier (MR-PRESSO) methods. Furthermore, we conducted mediation analysis to investigate the contribution of blood pressure and other cardiovascular disease-related traits. Results: The two-step Mendelian randomization analysis revealed that higher levels of glycine in the blood were associated with a reduced risk of CAD in Europeans [odds ratio ( OR)=0.84, 95% confidence interval ( CI): 0.72, -0.98; P=0.029] and East Asians: ( OR=0.76, 95% CI: 0.66, -0.89; P=3.57×10 -4). Sensitivity analysis confirmed the robustness of these findings. Additionally, our results suggest that about 6.06% of the observed causal effect is mediated through genetically predicted systolic blood pressure (SBP) in the European population. Discussion: Our results contribute to the current knowledge regarding the involvement of glycine in the progression of CAD, and provide valuable methodological insights for the prevention and treatment of this condition.

15.
ACS Omega ; 9(5): 5829-5837, 2024 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-38343950

RESUMEN

To perform the dissolved gas analysis in transformer oil, in this work, we propose the Ni-dispersed PdS2 (Ni-PdS2) monolayer as a promising sensing material for three typical dissolved gases H2, CO, and C2H2. For the Ni-dispersing process, we find that Ni atoms can be chemically stably adsorbed on the PdS2 surface with a binding energy of -4.11 eV. For gas adsorption systems, it is found that the Ni-PdS2 monolayer allows the physisorption of H2 molecules and the chemisorption of CO and C2H2 molecules. Besides, the analysis of electronic properties of the Ni-PdS2/gas system reveals its potential as a resistance-type H2 or C2H2 sensor with sensing responses of -40.9 and 261.5%, separately, and the WF analysis indicates its low potential as a WF-based gas sensor for the three gases. These findings indicate the Ni-dispersed behavior on the PdS2 surface and the gas-sensing potential of the Ni-PdS2 monolayer, which we expect can facilitate more investigations about PdS2-based materials for applications in gas adsorptions and sensing in some other fields.

16.
Comput Struct Biotechnol J ; 23: 358-368, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38223344

RESUMEN

Extrachromosomal circular DNA (eccDNA) has recently gained increasing attention due to its significant role in cancer and other pathophysiologic states. The majority of circular DNAs detected by Circle-seq are small-size eccDNAs with enigmatic functions. One major technical hurdle is to synthesize eccDNA for functional identification. Here, we describe CAES (Circle-seq based Artificial EccDNA Synthesis), a promising and reliable method for artificial eccDNA synthesis. Eight eccDNAs carrying different microRNA genes (eccMIR) found in gastric cancer tissues, ranging from 329 bp to 2189 bp in size, were created utilizing the CAES method. Exonuclease V and single restriction-endonuclease digestion identified the circular structure of synthetic eccDNAs. The DNA circularization efficiency afforded by CAES ranged from 15.6% to 31.1%, which was negatively correlated with the eccDNA length. In addition, we demonstrated that CAES-synthesized eccMIRs can express both miRNA-3p and - 5p molecules efficiently independent of a canonical promoter in human cell lines. Further assays proved that these eccMIRs were functional as they were able to repress the luciferase gene containing a miRNA-target sequence in the 3'UTR as well as the endogenous mRNA targets. Finally, kinetics study revealed that eccDNA exhibited a decay rate similar to the standard plasmids and linear DNA in cultured cells. Together, this study offers a rapid and convenient method for Circle-seq users to synthesize artificial eccDNAs. It also demonstrates the promising potential of eccMIR as a bacterial DNA-free vector for safe and robust miRNA overexpression in both basic research and therapeutic applications.

17.
Heliyon ; 10(2): e24325, 2024 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-38293517

RESUMEN

Tourism ecological security is the basic guarantee for the sustainable development of tourist sites, Huizhou Cultural and Ecological Reserve is an important area for the im-plementation of ecological protection in China, and it is of great significance to carry out research on tourism ecological security. The study adopted the DPSIR model to construct a comprehensive evaluation index system for tourism ecological security and used entropy value-TOPSIS and ArcGIS software to analyze the inter-annual changes and spatial change characteristics of tourism ecological security in the study area. The results show that: firstly, the comprehensive index of tourism ecological safety in the study area from 2010 to 2021 shows a trend of "decreasing-increasing" and an overall increasing trend; secondly, all the sub-systems show an increasing or stabilizing state in recent years during 2010-2021; the state and response sub-systems show an increas-ing or stabilizing state in recent years; and the state and response sub-systems show an increasing trend in recent years. Secondly, all the subsystems showed an increase or stabilization in recent years between 2010 and 2021, and the state and response sub-systems are the main systems to improve the ecological safety of tourism in the study area; thirdly, the difference in the level of ecological safety of tourism in each county of the study area increased and then narrowed from 2010 to 2021, and the change of safety level usually shifted between neighboring levels, and the probability of transfer-ring across the levels was relatively small. , Shexian County, Yixian County, Qimen County, Tunxi District, and the tourism eco-safety level of Huangshan District, Hui-zhou District, Jixi County, and Xiuning County increased at a faster rate than other counties. The study further extends the scale to the district and county level, tries to explore the relevant factors affecting the ecological security of tourism, and proposes countermeasures for the sustainable development of the study area based on the re-sults, which will bring some reference value to the ecological governance and policy formulation of this kind of research.

18.
Spectrochim Acta A Mol Biomol Spectrosc ; 308: 123714, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38061106

RESUMEN

YH-2 represents an innovative, non-invasive fluorescent probe featuring a structure based on flavonoid onium salts. It is characterized by a well-suited Stokes shift and emits in the near-infrared (NIR) wavelength range. Its capacity to distinguish between HeLa cells, HepG2 cells, and LO2 cells is attributed to differential intracellular viscosity. Experimental results validate the heightened viscosity of organelles, such as the endoplasmic reticulum (ER), mitochondria and lysosomes in tumor cells compared to LO2 cells. Of paramount importance, YH-2 demonstrates the capability to swiftly image tumors within a mere 20 min following tail vein injection and this imaging ability can be sustained for an extended period of up to 5 h. This method offers a potential tumor diagnostic strategy in vivo.


Asunto(s)
Colorantes Fluorescentes , Lisosomas , Humanos , Células HeLa , Colorantes Fluorescentes/química , Mitocondrias/química , Retículo Endoplásmico , Cloruro de Sodio , Imagen Óptica/métodos , Viscosidad
19.
Adv Mater ; 36(11): e2311375, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38085673

RESUMEN

Twin boundary (TB) engineering provides exciting opportunities to tune the performance levels of metal-based electrocatalysts. However, the controllable construction of TB greatly relies on surfactants, blocking active sites, and electron transfer by surfactants. Here, a surfactant-free and facile strategy is proposed for synthesizing copper (Cu) nanocatalysts with dense hierarchical TB networks (HTBs) by the rapid thermal reductions in metastable CuO nanosheets in H2 . As revealed by in situ transmission electron microscopy, the formation of HTBs is associated with the fragmentation of nanosheets in different directions to generate abundant crystal nuclei and subsequently unconventional crystal growth through the collision and coalescence of nuclei. Impressively, the HTBs endow Cu with excellent electrocatalytic performance for direct nitrate-ammonia conversion, superior to that of Cu with a single-oriented TB and without TB. It is discovered that the HTBs induce the formation of compressive strains, thereby creating a synergistic effect of TBs and strains to efficiently tune the binding energies of Cu with nitrogen intermediates (i.e., NO2 *) and thus promote the tandem reaction process of NO3 - -to-NO2 - and subsequent NO2 - -to-NH3 electrocatalysis. This work demonstrates the crucial role of HTBs for boosting electrocatalysis via the synergistic effect of TBs and strains.

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