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1.
Nature ; 567(7749): 516-520, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30818324

RESUMEN

The nitrogen cycle has been radically changed by human activities1. China consumes nearly one third of the world's nitrogen fertilizers. The excessive application of fertilizers2,3 and increased nitrogen discharge from livestock, domestic and industrial sources have resulted in pervasive water pollution. Quantifying a nitrogen 'boundary'4 in heterogeneous environments is important for the effective management of local water quality. Here we use a combination of water-quality observations and simulated nitrogen discharge from agricultural and other sources to estimate spatial patterns of nitrogen discharge into water bodies across China from 1955 to 2014. We find that the critical surface-water quality standard (1.0 milligrams of nitrogen per litre) was being exceeded in most provinces by the mid-1980s, and that current rates of anthropogenic nitrogen discharge (14.5 ± 3.1 megatonnes of nitrogen per year) to fresh water are about 2.7 times the estimated 'safe' nitrogen discharge threshold (5.2 ± 0.7 megatonnes of nitrogen per year). Current efforts to reduce pollution through wastewater treatment and by improving cropland nitrogen management can partially remedy this situation. Domestic wastewater treatment has helped to reduce net discharge by 0.7 ± 0.1 megatonnes in 2014, but at high monetary and energy costs. Improved cropland nitrogen management could remove another 2.3 ± 0.3 megatonnes of nitrogen per year-about 25 per cent of the excess discharge to fresh water. Successfully restoring a clean water environment in China will further require transformational changes to boost the national nutrient recycling rate from its current average of 36 per cent to about 87 per cent, which is a level typical of traditional Chinese agriculture. Although ambitious, such a high level of nitrogen recycling is technologically achievable at an estimated capital cost of approximately 100 billion US dollars and operating costs of 18-29 billion US dollars per year, and could provide co-benefits such as recycled wastewater for crop irrigation and improved environmental quality and ecosystem services.


Asunto(s)
Agricultura/métodos , Fertilizantes/análisis , Fertilizantes/provisión & distribución , Ciclo del Nitrógeno , Nitrógeno/análisis , Nitrógeno/provisión & distribución , Calidad del Agua/normas , Agricultura/estadística & datos numéricos , Animales , China , Ecosistema , Monitoreo del Ambiente , Abastecimiento de Alimentos/métodos , Abastecimiento de Alimentos/estadística & datos numéricos , Humanos , Contaminantes Químicos del Agua/análisis , Contaminación del Agua/análisis
2.
Angew Chem Int Ed Engl ; 63(29): e202403698, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38720517

RESUMEN

Trigonal planar M3(O/OH) trimers are among the most important clusters in inorganic chemistry and are the foundational features of multiple high-impact MOF platforms. Here we introduce a concept called isoreticular cluster series and demonstrate that M3(O/OH), as the first member of a supertrimer series, can be combined with a higher hierarchical member (double-deck trimer here) to advance isoreticular chemistry. We report here an isoreticular series of pore-space-partitioned MOFs called M3M6 pacs made from co-assembly between M3 single-deck trimer and M3x2 double-deck trimer. Important factors were identified on this multi-modular MOF platform to guide optimization of each module, which enables the phase selection of M3M6 pacs by overcoming the formation of previously-always-observed same-cluster phases. The new pacs materials exhibit high surface area and high uptake capacity for CO2 and small hydrocarbons, as well as selective adsorption properties relevant to separation of industrially important mixtures such as C2H2/CO2 and C2H2/C2H4. Furthermore, new M3M6 pacs materials show electrocatalytic properties with high activity.

3.
J Am Chem Soc ; 145(20): 10980-10986, 2023 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-37163701

RESUMEN

Flexi-MOFs are typically limited to low-connected (<9) frameworks. Here we report a platform-wide approach capable of creating a family of high-connected materials (collectively called CPM-220) that integrate exceptional framework flexibility with high rigidity. We show that the multi-module nature of the pore-space-partitioned pacs (partitioned acs net) platform allows us to introduce flexibility as well as to simultaneously impose high rigidity in a tunable module-specific fashion. The inter-modular synergy has remarkable macro-morphological and sub-nanometer structural impacts. A prominent manifestation at both length scales is the retention of X-ray-quality single crystallinity despite huge hexagonal c-axial contraction (≈ 30%) and harsh sample treatment such as degassing and sorption cycles. CPM-220 sets multiple precedents and benchmarks on the pacs platform in both structural and sorption properties. They possess exceptionally high benzene/cyclohexane selectivity, unusual C3H6 and C3H8 isotherms, and promising separation performance for small gas molecules such as C2H2/CO2.

4.
Small ; 19(5): e2205119, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36440683

RESUMEN

A new perspective is proposed in the design of pore-space-partitioned MOFs that is focused on ligand symmetry properties sub-divided here into three hierarchical levels: 1) overall ligand, 2) ligand substructure such as backbone or core, and 3) the substituent groups. Different combinations of the above symmetry properties exist. Given the close correlation between nature of chemical moiety and its symmetry, such a unique perspective into ligand symmetry and sub-symmetry in MOF design translates into the influences on MOF properties. Five new MOFs have been prepared that exhibit excellent hydrothermal stability and high-performance adsorption properties with potential applications such as C3 H6 /C2 H4 and C2 H2 /CO2 selective adsorption. The combination of high stability with high benzene/cyclohexane selectivity of ≈13.7 is also of particular interest.

5.
Curr Cardiol Rep ; 25(7): 747-759, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37233923

RESUMEN

PURPOSE OF REVIEW: Heart failure is a severe clinical syndrome with complex and unclarified mechanisms, and it poses a serious threat to human health. MicroRNA, a non-coding RNA, can directly bind to target genes and regulate their expression. The important role of microRNAs in the development of HF has become a hot topic of research in recent years. This paper summarizes and prospects the mechanisms of microRNAs in regulating cardiac remodeling during heart failure to provide reference ideas for further research and clinical treatment. RECENT FINDINGS: With extensive research, more target genes for microRNAs have been clarified. By modulating various molecules, microRNAs affect the contractile function of the myocardium and alter the process of myocardial hypertrophy, myocyte loss, and fibrosis, thereby interfering with the process of cardiac remodeling and exerting an important effect in the process of heart failure. Based on the above mechanism, microRNAs have promising applications in the diagnosis and treatment of heart failure. MicroRNAs form a complex post-transcriptional control mechanism of gene expression, and the increase or decrease of their content during heart failure largely alters the course of cardiac remodeling. By continuously identifying their target genes, it is expected to achieve more precise diagnosis and treatment of this important topic of heart failure.


Asunto(s)
Insuficiencia Cardíaca , MicroARNs , Humanos , MicroARNs/genética , MicroARNs/metabolismo , Remodelación Ventricular/genética , Miocardio/metabolismo , Regulación de la Expresión Génica
6.
Angew Chem Int Ed Engl ; 62(14): e202300721, 2023 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-36780305

RESUMEN

Multi-module design of framework materials with multiple distinct building blocks has attracted much attention because such materials are more amenable to compositional and geometrical tuning and thus offer more opportunities for property optimization. Few examples are known that use environmentally friendly and cost-effective solvent-free method to synthesize such materials. Here, we report the use of solvent-free method (also modulator-free) to synthesize a series of multi-module MOFs with high stability and separation property for C2 H2 /CO2 . The synthesis only requires simple mixing of reactants and short reaction time (2 h). Highly porous and stable materials can be made without any post-synthetic activation. The success of solvent-free synthesis of multi-module MOFs reflects the synergy between different modules, resulting in stable pore-partitioned materials, despite the fact that other competitive crystallization pathways with simpler framework compositions also exist.

7.
Small ; 17(22): e2003167, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32844577

RESUMEN

Metal trimers [M3 (O/OH)](OOCR)6 are among the most important structural building blocks. From these trimers, a great success has been achieved in the design of 6- or 9-connected framework materials with various topological features and outstanding gas-sorption properties. In comparison, 8-connected trimer-based metal-organic frameworks (MOFs) are rare. Given multiple competitive pathways for the formation of 6- or 9-connected frameworks, it remains challenging to identify synthetic or structural parameters that can be used to direct the self-assembly process toward trimer-based 8-connected materials. Here, a viable strategy called angle bending modulation is revealed for creating a prototypical MOF type based on 8-connected M3 (OH)(OOCR)5 (Py-R)3 trimers (M = Zn, Co, Fe). As a proof of concept, six members in this family are synthesized using three types of ligands (CPM-80, -81, and -82). These materials do not possess open-metal sites and show excellent uptake capacity for various hydrocarbon gas molecules and inverse C2 H6 /C2 H4 selectivity. CPM-81-Co, made from 2,5-furandicarboxylate and isonicotinate, features selectivity of 1.80 with high uptake capacity for ethane (123 cm3 g-1 ) and ethylene (113 cm3 g-1 ) at 298 K and 1 bar.

8.
J Org Chem ; 86(7): 5345-5353, 2021 04 02.
Artículo en Inglés | MEDLINE | ID: mdl-33710879

RESUMEN

A facile method for the preparation of 2,3-dialkyl-substituted quinazolinones from readily available N-arylamides and commercial isocyanates was developed. This one-pot procedure involves the chemoselective activation of the secondary amide with Tf2O/2-Br-Pyr, the sequential addition of isocyanate, and cyclization. The mild reaction is general for a wide range of substrates and can be run on a gram scale.


Asunto(s)
Amidas , Isocianatos , Ciclización , Estructura Molecular , Quinazolinonas
9.
J Nanobiotechnology ; 19(1): 391, 2021 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-34823562

RESUMEN

BACKGROUND: Considering the threat of the COVID-19 pandemic, caused by SARS-CoV-2, there is an urgent need to develop effective treatments. At present, neutralizing antibodies and small-molecule drugs such as remdesivir, the most promising compound to treat this infection, have attracted considerable attention. However, some potential problems need to be concerned including viral resistance to antibody-mediated neutralization caused by selective pressure from a single antibody treatment, the unexpected antibody-dependent enhancement (ADE) effect, and the toxic effect of small-molecule drugs. RESULTS: Here, we constructed a type of programmed nanovesicle (NV) derived from bispecific CAR-T cells that express two single-chain fragment variables (scFv), named CR3022 and B38, to target SARS-CoV-2. Nanovesicles that express both CR3022 and B38 (CR3022/B38 NVs) have a stronger ability to neutralize Spike-pseudovirus infectivity than nanovesicles that express either CR3022 or B38 alone. Notably, the co-expression of CR3022 and B38, which target different epitopes of spike protein, could reduce the incidence of viral resistance. Moreover, the lack of Fc fragments on the surface of CR3022/B38 NVs could prevent ADE effects. Furthermore, the specific binding ability to SARS-CoV-2 spike protein and the drug loading capacity of CR3022/B38 NVs can facilitate targeted delivery of remdesiver to 293 T cells overexpressing spike protein. These results suggest that CR3022/B38 NVs have the potential ability to target antiviral drugs to the main site of viral infection, thereby enhancing the antiviral ability by inhibiting intracellular viral replication and reducing adverse drug reactions. CONCLUSIONS: In summary, we demonstrate that nanovesicles derived from CAR-T cells targeting the spike protein of SARS-COV-2 have the ability to neutralize Spike-pseudotyped virus and target antiviral drugs. This novel therapeutic approach may help to solve the dilemma faced by neutralizing antibodies and small-molecule drugs in the treatment of COVID-19.


Asunto(s)
COVID-19/metabolismo , Glicoproteína de la Espiga del Coronavirus/metabolismo , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/metabolismo , Antivirales/uso terapéutico , COVID-19/inmunología , Humanos , Modelos Teóricos
10.
J Dairy Sci ; 103(5): 3937-3949, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32171514

RESUMEN

Morbidity and mortality as a result of liver disease are major problems around the world, especially from alcoholic liver disease (ALD), which is characterized by hepatic inflammation and intestinal microbial imbalance. In this study, we investigated the hepatoprotective effects of camel milk (CM) in a mouse model of acute ALD and the underlying mechanism at the gut microbiota and transcriptome level. Male Institute of Cancer Research mice (n = 24; Beijing Weitong Lihua Experimental Animal Technology Co. Ltd., China) were divided into 3 groups: normal diet (NC); normal diet, then ethanol (ET); and normal diet and camel milk (CM), then ethanol (ET+CM). Analysis of serum biochemical indexes and histology revealed a reduction in hepatic inflammation in the ET+CM group. Sequencing of 16S rRNA showed that CM modulated the microbial communities, with an increased proportion of Lactobacillus and reduced Bacteroides, Alistipes, and Rikenellaceae RC9 gut group. Comparative hepatic transcriptome analysis revealed 315 differentially expressed genes (DEG) in the ET+CM and ET groups (150 upregulated and 165 downregulated). Enrichment analysis revealed that CM downregulated the expression of inflammation-related (ILB and CXCL1) genes in the IL-17 and tumor necrosis factor (TNF-α) pathways. We conclude that CM modulates liver inflammation and alleviates the intestinal microbial disorder caused by acute alcohol injury, indicating the potential of dietary CM in protection against alcohol-induced liver injury.


Asunto(s)
Camelus , Etanol/farmacología , Microbioma Gastrointestinal/efectos de los fármacos , Hepatopatías Alcohólicas/metabolismo , Hepatopatías Alcohólicas/microbiología , Leche/fisiología , Transcriptoma , Animales , Modelos Animales de Enfermedad , Inflamación/metabolismo , Lactobacillus/genética , Hígado/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Microbiota , ARN Ribosómico 16S , Factor de Necrosis Tumoral alfa/metabolismo
11.
Chemistry ; 25(71): 16358-16365, 2019 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-31750594

RESUMEN

Zeolitic imidazolate frameworks (ZIFs) are traditionally synthesized solvothermally by using cost- and waste-incurring organic solvents. Here, a direct synthesis method is reported for ZIF-8, ZIF-67, and their heterometallic versions from solid precursors only. This solvent-free crystallization method not only completely avoids organic solvents, but also provides an effective path for the synthesis of homogeneous mixed-metal ZIFs. Furthermore, under templating by NaCl/ZnCl2 eutectic salt, carbonization of the ZIF materials gives rise to a series of N-containing high-surface-area carbon materials with impressive catalytic properties for the oxygen reduction reaction.

12.
J Virol ; 91(15)2017 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-28515293

RESUMEN

Virus-like vesicles (VLVs) are membrane-enclosed vesicles that resemble native enveloped viruses in organization but lack the viral capsid and genome. During the productive infection of tumor-associated gammaherpesviruses, both virions and VLVs are produced and are released into the extracellular space. However, studies of gammaherpesvirus-associated VLVs have been largely restricted by the technical difficulty of separating VLVs from mature virions. Here we report a strategy of selectively isolating VLVs by using a Kaposi's sarcoma-associated herpesvirus (KSHV) mutant that is defective in small capsid protein and is unable to produce mature virions. Using mass spectrometry analysis, we found that VLVs contained viral glycoproteins required for cellular entry, as well as tegument proteins involved in regulating lytic replication, but lacked capsid proteins. Functional analysis showed that VLVs induced the expression of the viral lytic activator RTA, initiating KSHV lytic gene expression. Furthermore, employing RNA sequencing, we performed a genomewide analysis of cellular responses triggered by VLVs and found that PRDM1, a master regulator in cell differentiation, was significantly upregulated. In the context of KSHV replication, we demonstrated that VLV-induced upregulation of PRDM1 was necessary and sufficient to reactivate KSHV by activating its RTA promoter. In sum, our study systematically examined the composition of VLVs and demonstrated their biological roles in manipulating host cell responses and facilitating KSHV lytic replication.IMPORTANCE Cells lytically infected with tumor-associated herpesviruses produce a high proportion of virus-like vesicles (VLVs). The composition and function of VLVs have not been well defined, largely due to the inability to efficiently isolate VLVs that are free of virions. Using a cell system capable of establishing latent KSHV infection and robust reactivation, we successfully isolated VLVs from a KSHV mutant defective in the small capsid protein. We quantitatively analyzed proteins and microRNAs in VLVs and characterized the roles of VLVs in manipulating host cells and facilitating viral infection. More importantly, we demonstrated that by upregulating PRDM1 expression, VLVs triggered differentiation signaling in targeted cells and facilitated viral lytic infection via activation of the RTA promoter. Our study not only demonstrates a new strategy for isolating VLVs but also shows the important roles of KSHV-associated VLVs in intercellular communication and the viral life cycle.


Asunto(s)
Regulación Viral de la Expresión Génica , Herpesvirus Humano 8/fisiología , Interacciones Huésped-Patógeno , Proteínas Represoras/biosíntesis , Transducción de Señal , Virosomas/química , Replicación Viral , Diferenciación Celular , Línea Celular , Herpesvirus Humano 8/química , Humanos , Proteínas Inmediatas-Precoces/metabolismo , Factor 1 de Unión al Dominio 1 de Regulación Positiva , Transactivadores/metabolismo , Regulación hacia Arriba
13.
Proc Natl Acad Sci U S A ; 112(7): E649-56, 2015 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-25646489

RESUMEN

With just one eighth the size of the major capsid protein (MCP), the smallest capsid protein (SCP) of human tumor herpesviruses--Kaposi's sarcoma-associated herpesvirus (KSHV) and Epstein-Barr virus (EBV)--is vital to capsid assembly, yet its mechanism of action is unknown. Here, by cryoEM of KSHV at 6-Å resolution, we show that SCP forms a crown on each hexon and uses a kinked helix to cross-link neighboring MCP subunits. SCP-null mutation decreased viral titer by 1,000 times and impaired but did not fully abolish capsid assembly, indicating an important but nonessential role of SCP. By truncating the C-terminal half of SCP and performing cryoEM reconstruction, we demonstrate that SCP's N-terminal half is responsible for the observed structure and function whereas the C-terminal half is flexible and dispensable. Serial truncations further highlight the critical importance of the N-terminal 10 aa, and cryoEM reconstruction of the one with six residues truncated localizes the N terminus of SCP in the cryoEM density map and enables us to construct a pseudoatomic model of SCP. Fitting of this SCP model and a homology model for the MCP upper domain into the cryoEM map reveals that SCP binds MCP largely via hydrophobic interactions and the kinked helix of SCP bridges over neighboring MCPs to form noncovalent cross-links. These data support a mechanistic model that tumor herpesvirus SCP reinforces the capsid for genome packaging, thus acting as a cementing protein similar to those found in many bacteriophages.


Asunto(s)
Cápside/ultraestructura , Microscopía por Crioelectrón/métodos , Herpesvirus Humano 8/ultraestructura , Mutagénesis , Secuencia de Aminoácidos , Secuencia de Bases , Cápside/metabolismo , Línea Celular , Cartilla de ADN , Herpesvirus Humano 8/genética , Herpesvirus Humano 8/metabolismo , Humanos , Datos de Secuencia Molecular , Conformación Proteica , Homología de Secuencia de Aminoácido
14.
Curr Med Chem ; 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38362681

RESUMEN

Influenza is an acute respiratory disease caused by influenza viruses. It has the characteristics of fast transmission and strong infectivity, and it does great harm to human health and survival. It is estimated that the seasonal influenza epidemics every year will cause about one billion cases of infections and hundreds of thousands of deaths worldwide, while influenza A virus is the leading cause of infection and death. Currently, the main drugs used in clinics to treat influenza viruses are neuraminidase inhibitors, and these drugs have shown excellent efficacy in treating influenza viruses. However, various mutant strains have developed resistance to these effective drugs in clinics (such as the subtype mutant strains of H274Y in H1N1 or H5N1 and E119V in H3N2 have developed resistance to Oseltamivir). Influenza viruses mutate frequently, and new viral strains are constantly discovered, and the pandemics will break out at any time. Therefore, it is urgent to develop efficient and broad-spectrum drugs to prevent and treat the influenza pandemic caused by the emerging new subtypes. This review focuses on describing the pandemic history, the structure, function and prevention methods of influenza viruses and the progress of the development of anti-influenza drugs, to provide the reference for prevention and treatment of influenza viruses and development of influenza virus inhibitors.

15.
Clin Res Cardiol ; 2024 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-38451260

RESUMEN

This study aimed to determine the effect of supervised exercise training (SET) on cardiovascular function in patients with intermittent claudication (IC). A systematic search in MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases was conducted. Primary outcomes were systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), rate pressure product (RPP), cardiac output (CO), peak oxygen consumption (VO2peak), and heart rate variability (HRV). Secondary outcomes were maximum walking distance (MWD) and pain-free walking distance (PFWD). Outcomes were reported as weighted mean difference (WMD) between the SET group and the control group and synthesized by using the random-effects model. Seventeen RCTs with a total of 936 patients were included in this review. SET resulted in significant improvements of SBP (WMD = - 7.40, 95% CI - 10.69 ~ - 4.11, p < 0.001, I2 = 15.2%), DBP (WMD = - 1.92, 95% CI - 3.82 ~ - 0.02, p = 0.048, I2 = 0.0%), HR (WMD = - 3.38, 95% CI - 6.30 ~ - 0.46, p = 0.023, I2 = 0.0%), RPP (WMD = - 1072.82, 95% CI - 1977.05 ~ - 168.59, p = 0.020, I2 = 42.7%), and VO2peak with plantar flexion ergometer exercise (WMD = 5.57, 95% CI 1.66 ~ 9.49, p = 0.005, I2 = 62.4%), whereas CO and HRV remained statistically unaltered. SET also improved MWD (WMD = 139.04, 95% CI 48.64 ~ 229.44, p = 0.003, I2 = 79.3%) and PFWD (WMD = 40.02, 95% CI 23.85 ~ 56.18, p < 0.001, I2 = 0.0%). In conclusion, SET is effective in improving cardiovascular function in patients with IC, which was confirmed on outcomes of cardiovascular function associated with exercise ability. The findings hold out that the standard therapy of SET can improve not only walking distance but also cardiovascular function in patients with IC.

16.
Acta Biomater ; 157: 451-466, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36442821

RESUMEN

Immune checkpoint blockade therapy targeting programmed death-1 (PD-1) or its major ligand programmed death-ligand 1 (PD-L1) has achieved remarkable success in the treatment of several tumors, including colorectal cancer. However, the efficacy of PD-1/PD-L1 inhibitors is limited in some colorectal cancers within the immunosuppressive tumor microenvironment (such as when there is a lack of immune cell infiltration). Herein, anti-PD-L1 functionalized biomimetic polydopamine-modified gold nanostar nanoparticles (PDA/GNS@aPD-L1 NPs) were developed for synergistic anti-tumor treatment by combining PD-1/PD-L1 blockade with photothermal ablation. PDA/GNS@aPD-L1 NPs were prepared by encapsulating photothermal nanoparticles (polydopamine-modified gold nanostar, PDA-GNS) with cell membrane isolated from anti-PD-L1 single-chain variable fragment (scFv) over-expressing cells. In addition to disrupting PD-1/PD-L1 immunosuppressive signals, the anti-PD-L1 scFv on the membrane of PDA/GNS@aPD-L1 NPs was conducive to the accumulation of PDA-GNS at tumor sites. Importantly, the tumor photothermal ablation induced by PDA-GNS could reverse the immunosuppressive tumor microenvironment, thereby further improving the efficiency of PD-1/PD-L1 blockade therapy. In this study, the synthetized PDA/GNS@aPD-L1 NPs exhibited good biocompatibility, efficient photothermal conversion ability, and enhanced tumor-targeting ability. In vivo studies revealed that a PDA/GNS@aPD-L1 NP-based therapeutic strategy significantly inhibited tumor growth, and prolonged overall survival by further promoting the maturation of dendritic cells (DCs), increasing the infiltration of CD8+T cells, and decreasing the number of immunosuppressive cells (such as regulatory T cells and myeloid-derived suppressive cells). Collectively, the developed PDA/GNS@aPD-L1 NP-based therapeutic strategy combines PD-1/PD-L1 blockade with photothermal ablation, which could remodel the tumor microenvironment for effective clinical colorectal cancer therapy. STATEMENT OF SIGNIFICANCE: Immunosuppressive tumor microenvironment is the main challenge facing programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) blockade therapy. By encapsulating photothermal nanoparticles (polydopamine-modified gold nanostar, PDA-GNS) with cell membrane over-expressing anti-PD-L1 single-chain variable fragment, we constructed anti-PD-L1 functionalized biomimetic nanoparticles (PDA/GNS@aPD-L1 NPs). By specific binding to the PD-L1 present on tumor cells, PDA/GNS@aPD-L1 NPs could disrupt PD-1/PD-L1 immunosuppression signaling, and effectively deliver PDA-GNS targeting to tumor sites. Additionally, PDA-GNS-mediated local photothermal ablation of tumors promoted the release of tumor-associated antigens and thus activated anti-tumor immune responses. Meanwhile, hyperthermia facilitates immune cell infiltration by increasing tumor vascular permeability. Therefore, PDA/GNS@aPD-L1 NPs could sensitize tumors to PD-1/PD-L1 blockade therapy by remodeling the immunosuppressive tumor microenvironment, which provides a new strategy for tumor treatment.


Asunto(s)
Neoplasias Colorrectales , Nanopartículas , Anticuerpos de Cadena Única , Humanos , Receptor de Muerte Celular Programada 1/metabolismo , Biomimética , Ligandos , Inmunoterapia , Neoplasias Colorrectales/metabolismo , Oro/farmacología , Línea Celular Tumoral , Microambiente Tumoral
17.
ACS Sens ; 8(4): 1658-1666, 2023 04 28.
Artículo en Inglés | MEDLINE | ID: mdl-36945081

RESUMEN

Metal-Organic Frameworks (MOFs) can deliver many advantages when acting as enzyme mimics to assist with signal amplification in molecular detection: they have abundant active catalytic sites per unit volume of the material; their structures and elemental compositions are highly tunable, and their high specific surface area and porous property can assist with target separation and enrichment. In the present work, we have demonstrated that, by adding the pore partition agent, 2,4,6-tris(4-pyridyl)pyridine (TPY) during synthesis of the bimetallic Fe/Co-MIL-88(NH2) MOF to block the open metal sites, a highly porous MOF of Fe/Co-TPY-MIL-88(NH2) can be produced. This material also exhibits high stability in basic solutions and biofluids and possesses high peroxidase-mimicking activity, which can be utilized to produce long-lasting chemiluminescence (CL) from luminol and H2O2. Moreover, acting as the peroxidase-mimic, the Fe/Co-TPY-MIL-88(NH2) MOF can form the enzymatic cascade with glucose oxidase (GOx) for biomarker detection. When applied to detect extracellular vesicles (EVs), the MOF material and GOx are brought to the proximity on the EVs through two surface proteins, which triggers the enzyme cascade to produce high CL from glucose and luminol. EVs within the concentration range of 5 × 105 to 4 × 107 particles/mL can be detected with an LOD of 1 × 105 particles/mL, and the method can be used to analyze EV contents in human serum without sample preparation and EV purification. Overall, our work demonstrates that the high versatility and tunability of the MOF structures could bring in significant benefits to biosensing and enable ultrasensitive detection of biomarkers with judicious material designs.


Asunto(s)
Vesículas Extracelulares , Estructuras Metalorgánicas , Humanos , Estructuras Metalorgánicas/química , Luminiscencia , Luminol/química , Peróxido de Hidrógeno/química , Peroxidasas/metabolismo , Peroxidasa , Glucosa Oxidasa/química , Vesículas Extracelulares/metabolismo
18.
Nanomaterials (Basel) ; 13(4)2023 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-36839039

RESUMEN

As a new generation of non-volatile memory, phase change random access memory (PCRAM) has the potential to fill the hierarchical gap between DRAM and NAND FLASH in computer storage. Sb2Te3, one of the candidate materials for high-speed PCRAM, has high crystallization speed and poor thermal stability. In this work, we investigated the effect of carbon doping on Sb2Te3. It was found that the FCC phase of C-doped Sb2Te3 appeared at 200 °C and began to transform into the HEX phase at 25 °C, which is different from the previous reports where no FCC phase was observed in C-Sb2Te3. Based on the experimental observation and first-principles density functional theory calculation, it is found that the formation energy of FCC-Sb2Te3 structure decreases gradually with the increase in C doping concentration. Moreover, doped C atoms tend to form C molecular clusters in sp2 hybridization at the grain boundary of Sb2Te3, which is similar to the layered structure of graphite. And after doping C atoms, the thermal stability of Sb2Te3 is improved. We have fabricated the PCRAM device cell array of a C-Sb2Te3 alloy, which has an operating speed of 5 ns, a high thermal stability (10-year data retention temperature 138.1 °C), a low device power consumption (0.57 pJ), a continuously adjustable resistance value, and a very low resistance drift coefficient.

19.
Cell Rep ; 42(1): 111919, 2023 01 31.
Artículo en Inglés | MEDLINE | ID: mdl-36640346

RESUMEN

Cognitive control involves flexibly combining multiple sensory inputs with task-dependent goals during decision making. Several tasks involving conflicting sensory inputs and motor outputs have been proposed to examine cognitive control, including the Stroop, Flanker, and multi-source interference task. Because these tasks have been studied independently, it remains unclear whether the neural signatures of cognitive control reflect abstract control mechanisms or specific combinations of sensory and behavioral aspects of each task. To address these questions, we record invasive neurophysiological signals from 16 patients with pharmacologically intractable epilepsy and compare neural responses within and between tasks. Neural signals differ between incongruent and congruent conditions, showing strong modulation by conflicting task demands. These neural signals are mostly specific to each task, generalizing within a task but not across tasks. These results highlight the complex interplay between sensory inputs, motor outputs, and task demands underlying cognitive control processes.


Asunto(s)
Cognición , Humanos , Cognición/fisiología , Tiempo de Reacción/fisiología
20.
Front Cardiovasc Med ; 10: 1084611, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37051068

RESUMEN

Background: Cold exposure has been considered an essential risk factor for the global disease burden, while its role in cardiovascular diseases is still underappreciated. The increase in frequency and duration of extreme cold weather events like cold spells makes it an urgent task to evaluate the effects of ambient cold on different types of cardiovascular disease and to understand the factors contributing to the population's vulnerability. Methods: In the present systematic review and meta-analysis, we searched PubMed, Scopus, and Cochrane. We included original research that explored the association between cold exposure (low temperature and cold spell) and cardiovascular disease outcomes (mortality and morbidity). We did a random-effects meta-analysis to pool the relative risk (RR) of the association between a 1°C decrease in temperature or cold spells and cardiovascular disease outcomes. Results: In total, we included 159 studies in the meta-analysis. As a result, every 1°C decrease in temperature increased cardiovascular disease-related mortality by 1.6% (RR 1.016; [95% CI 1.015-1.018]) and morbidity by 1.2% (RR 1.012; [95% CI 1.010-1.014]). The most pronounced effects of low temperatures were observed in the mortality of coronary heart disease (RR 1.015; [95% CI 1.011-1.019]) and the morbidity of aortic aneurysm and dissection (RR 1.026; [95% CI 1.021-1.031]), while the effects were not significant in hypertensive disease outcomes. Notably, we identified climate zone, country income level and age as crucial influential factors in the impact of ambient cold exposure on cardiovascular disease. Moreover, the impact of cold spells on cardiovascular disease outcomes is significant, which increased mortality by 32.4% (RR 1.324; [95% CI 1.2341.421]) and morbidity by 13.8% (RR 1.138; [95% CI 1.015-1.276]). Conclusion: Cold exposure could be a critical risk factor for cardiovascular diseases, and the cold effect varies between disease types and climate zones. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO, identifier: CRD42022347247.

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