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1.
MAbs ; 16(1): 2322562, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38445633

RESUMO

Epithelial cell adhesion molecule (EpCAM) is a transmembrane glycoprotein that plays several roles in cancer biology. EpCAM is an attractive therapeutic target because of its expression in most solid tumors. However, targeting EpCAM has been challenging because it is also highly expressed in normal epithelial tissues. Initial attempts to develop EpCAM-specific T-cell engagers were unsuccessful due to severe cytokine release effects, as well as serious on-target, off-tumor drug-related toxicities. We developed novel, conditionally active biological (CAB) bispecific antibodies that bind to both EpCAM and CD3 in an acidic tumor microenvironment. In healthy tissues, binding to EpCAM and CD3 is greatly reduced by a novel, dual CAB selection, where each binding domain is independently blocked by the presence of physiological chemicals known as Protein-associated Chemical Switches (PaCS). The CAB anti-EpCAM T-cell engagers displayed the anticipated bispecific binding properties and mediated the potent lysis of EpCAM-positive cancer cell lines through the recruitment of T cells in the tumor microenvironment. Xenograft studies showed that the efficacy of CAB bispecific antibodies is similar to that of a non-CAB anti-EpCAM bispecific antibody, but they have markedly reduced toxicity in non-human primates, indicating an unprecedentedly widened therapeutic index of over 100-fold. These preclinical results indicate that the dual CAB bispecific antibody is potentially both a powerful and safe therapeutic platform and a promising T cell-engaging treatment for patients with EpCAM-expressing tumors.


Development of a novel conditionally active EpCAM-specific T-cell engager with enhanced safety and tolerability for treatment of solid tumors.


Assuntos
Anticorpos Biespecíficos , Produtos Biológicos , Neoplasias , Animais , Humanos , Molécula de Adesão da Célula Epitelial , Anticorpos Biespecíficos/farmacologia , Imunoterapia , Neoplasias/terapia , Microambiente Tumoral
2.
ACS Appl Mater Interfaces ; 16(13): 16601-16611, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38502203

RESUMO

Carbon Quantum dots (CQDs) are widely studied because of their good optical and electronic characteristics and because they can easily generate photocarriers. Nitrogen-doped CQDs (NCQDs) may exhibit improved hydrophilic, optical, and electron-transfer properties, which are conducive to photocatalytic hydrogen evolution. In this paper, NCQD-modified ZnS catalysts were successfully prepared. Under the irradiation of the full spectrum, the H2 evolution rate of the optimal catalyst 0.25 wt % NCQDs/ZnS achieves 5.70 mmol g-1 h-1, which is 11.88, 43.84, and 5.14 times the values of ZnS (0.48 mmol g-1 h-1), NCQDs (0.13 mmol g-1 h-1), and CQDs/ZnS (1.11 mmol g-1 h-1), respectively. Furthermore, it shows good stability, indicating that the modification of NCQDs prevents the photocorrosion and oxidation of ZnS. The enhanced performance is due to NCQD loading, which promotes the separation of photogenerated carriers, optimizes the structures, and increases the specific surface area. This work highlights the fact that NCQD-modified ZnS may afford a new strategy to synthesize ZnS-based photocatalysts with enhanced H2 production performance.

3.
Front Neurol ; 15: 1347387, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38356891

RESUMO

Objective: To compare the serum levels of 12 cytokines in migraine group, encephalitis with headache symptoms group, pneumonia without headache symptoms group and migraine subgroups to explore the cytokines associated with migraine in children and their levels. Methods: A total of 44 children with migraine, 27 children in the encephalitis group with headache symptoms and 44 children in the pneumonia group without headache symptoms were selected from January 2022 to August 2023 in Hebei Children's Hospital. They were all tested for serum cytokines by immunofluorescence assay. The migraine group was further divided into subgroups according to different age, gender, course of disease, and presence of coinfection. The differences of serum cytokine levels among the above groups were compared, and the correlation analysis was carried out. Results: Except IL-5, there were no significant differences in the expression levels of other 11 inflammatory cytokines between migraine subgroups. Compared with encephalitis with headache symptoms group and pneumonia without headache symptoms group the serum levels of IL-4, TNF-α, IL-17A, and IL-12p70 were higher in migraine group than in pneumonia group, and the levels of IL-12p70 were higher than those in encephalitis group (p < 0.05). An increase in serum IL-12p70 (OR = 1.267, 95%CI 1.054-1.523, p = 0.012) and IL-17A (OR = 1.066, 95%CI 1.016-1.119, p = 0.010) levels had a significant effect on migraine. Conclusion: Elevated serum levels of IL-12p70 and IL-17A may increase the risk of migraine in children, which has certain diagnostic and predictive value.

4.
Quant Imaging Med Surg ; 14(1): 877-887, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38223094

RESUMO

Background: Sclerosing adenosis (SA) is a common proliferative benign lesion without atypia in the breast that may mimic invasive ductal carcinoma (IDC) on medical imaging, leading to it often being misdiagnosed and mistreated. Consequently, the purpose of this study was to assess the diagnostic value of multimodal ultrasound imaging in distinguishing SA from IDC. Methods: Multimodal ultrasound imaging, including automated breast volume scan (ABVS), elasticity imaging (EI), and color Doppler flow imaging (CDFI), were performed on 120 consecutive patients comprising 122 breast lesions (54 SA, 68 IDC). All lesions were pathologically confirmed. Multimodal ultrasound imaging features were compared between the two groups. Binary logistic regression analysis based on ABVS, EI, and CDFI was conducted to formulate a logistic regression equation for differentiating SA from IDC. The diagnostic performances of ABVS, EI, CDFI, and their combination were compared by the receiver operating characteristic (ROC) curve analysis. Results: The sensitivity, specificity, and accuracy of ABVS, EI, CDFI, and their combination in differentiating SA from IDC were, respectively, 75.00%, 72.22%, and 73.77%; 86.76%, 72.22%, and 80.33%; 73.53%, 64.81%, and 69.67%; and 88.24%, 74.07%, and 81.97%. Combining multimodal ultrasound imaging yielded an area under the curve (AUC) of 0.895 (95% confidence interval: 0.827-0.943), which was higher than that of ABVS, EI, and CDFI, with AUC values of 0.736, 0.795, and 0.692, respectively, and the difference was statistically significant (ABVS vs. combined model, P<0.001; CDFI vs. combined model, P<0.001; EI vs. combined model, P<0.001). There was no significant difference in the diagnostic efficacy among the three imaging modalities (ABVS vs. EI, P=0.266; ABVS vs. CDFI, P=0.4671; EI vs. CDFI, P=0.051). Compared with those in IDC, the calcification (16.67% vs. 57.35%; P<0.001) and retraction phenomena in the coronal planes (18.52% vs. 57.35%; P<0.001) were less common in patients with SA, while circumscribed margin (38.89% vs. 5.88%; P<0.001), vascularity grade 0-I (64.81% vs. 26.47%; P<0.001), and elasticity scores 1-3 (72.22% vs. 13.24%; P<0.001) were more frequently found in patients with SA. Patients with SA were significantly younger than were patients with IDC (43±11 vs. 54±11 years; P<0.001), and the lesion size was smaller in patients with SA than in those with IDC (median size 1.0 cm; interquartile range (IQR), 0.9 cm vs. median size 1.3 cm; IQR, 1.3 cm; P<0.001). Conclusions: The preliminary results suggested that multimodal ultrasound imaging can improve the diagnostic accuracy of SA and provide additional information for differential diagnosis of SA and IDC.

5.
Adv Mater ; 36(16): e2313074, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38237120

RESUMO

Development of polymer donors with simple chemical structure and low cost is of great importance for commercial application of organic solar cells (OSCs). Here, side-chain random copolymer PMQ-Si605 with a simply 6,7-difluoro-3-methylquinoxaline-thiophene backbone and 5% siloxane decoration of side chain is synthesized in comparison with its alternating copolymer PTQ11. Relative to molecular weight (Mn) of 28.3 kg mol-1 for PTQ11, the random copolymer PMQ-Si605 with minor siloxane decoration is beneficial for achieving higher Mn up to 51.1 kg mol-1. In addition, PMQ-Si605 can show stronger aggregation ability and faster charge mobility as well as more efficient exciton dissociation in active layer as revealed by femtosecond transient absorption spectroscopy. With L8-BO-F as acceptor, its PMQ-Si605 based OSCs display power conversion efficiency (PCE) of 18.08%, much higher than 16.21% for PTQ11 based devices. With another acceptor BTP-H2 to optimize the photovoltaic performance of PMQ-Si605, further elevated PCEs of 18.50% and 19.15% can be achieved with the binary and ternary OSCs, respectively. Furthermore, PMQ-Si605 based active layers are suitable for processing in high humidity air, an important factor for massive production of OSCs. Therefore, the siloxane decoration on polymer donors is promising, affording PMQ-Si605 as a high-performing and low cost candidate.

6.
Materials (Basel) ; 16(14)2023 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-37512388

RESUMO

Oxygen evolution reaction is a momentous part of electrochemical energy storage and conversion devices such as rechargeable metal-air batteries. It is particularly urgent to develop low-cost and efficient electrocatalysts for oxygen evolution reactions. As a potential substitute for noble metal electrocatalysts, transition metal selenides still prove challenging in improving the activity of oxygen evolution reaction and research into reaction intermediates. In this study, a simple one-step solvothermal method was used to prepare a polymetallic compound carbon matrix composite (Co9Se8/Ni3Se4/Fe3O4@C) with a multilayered nanosheets structure. It exhibited good OER activity in an alkaline electrolyte solution, with an overpotential of 268 mV at 10 mA/cm2. In addition, this catalyst also showed excellent performance in the 24 h stability test. The composite presents a multi-layer sheet structure, which effectively improves the contact between the active site and the electrolyte. The selenide formed by Ni and Co has a synergistic effect, and Fe3O4 and Co9Se8 form a heterojunction structure which can effectively improve the reaction activity by initiating the electronic coupling effect through the interface modification. In addition, carbon quantum dots have rich heteroatoms and electron transferability, which improves the electrochemical properties of the composites. This work provides a new strategy for the preparation of highly efficient OER electrocatalysts utilizing the multi-metal synergistic effect.

7.
J Colloid Interface Sci ; 650(Pt A): 784-797, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37441971

RESUMO

ZnIn2S4/ZnO heterostructures have been achieved by a simple in-situ growth solvothermal method. Under full spectrum irradiation, the optimal photocatalyst 2ZnIn2S4/ZnO exhibits H2 evolution rate of 13,638 (water/ethanol = 1:1) and 3036 (water) µmol·g-1h-1, which is respectively 4 and 5 times higher than that of pure ZnIn2S4. In situ illumination X-ray photoelectron spectroscopy (ISI-XPS) analysis and density functional theory (DFT) calculations show that the electrons of ZnIn2S4 are removed to ZnO through hybridization and form an internal electric field between ZnIn2S4 and ZnO. The optical properties of the catalyst and the effect of internal electric field (IEF) can increase photo-generated electrons (e-)-holes (h+) transport rate and enhance light collection, resulting in profitable photocatalytic properties. The photoelectrochemical and EPR results show that a stepped (S-scheme) heterojunction is formed in the ZnIn2S4/ZnO redox center, which greatly promotes separation of e--h+ pairs and efficient H2 evolution. This research offers an effective method for constructing an efficient S-Scheme photocatalytic system for H2 evolution.

8.
ACS Appl Mater Interfaces ; 14(37): 42102-42112, 2022 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-36097412

RESUMO

AlH3 is a metastable hydride with a theoretical hydrogen capacity of 10.01 wt % and is very easy to decompose during ball milling especially in the presence of many catalysts, which will lead to the attenuation of the available hydrogen capacity. In this work, AlH3 was ball milled in air (called "air-milling") with layered Ti3C2 to prepare a Ti3C2-catalyzed AlH3 hydrogen storage material. Such air-milled and Ti3C2-catalyzed AlH3 possesses excellent hydrogen storage performances, with a low initial decomposition temperature of just 61 °C and a high hydrogen release capacity of 8.1 wt %. In addition, 6.9 wt % of hydrogen can be released within 20 min at constantly 100 °C, with a low activation energy as low as 40 kJ mol-1. Air-milling will lead to the formation of an Al2O3 oxide layer on the AlH3 particles, which will prevent continuous decomposition of AlH3 when milling with active layered Ti3C2. The layered Ti3C2 will grip on and intrude into the AlH3 particle oxide layers and then catalyze the decomposition of AlH3 during heating. The strategy employing air-milling as a synthesis method and utilizing layered Ti3C2 as a catalyst in this work can solve the key issue of severe decomposition during ball milling with catalysts economically and conveniently and thus achieve both high-capacity and low-temperature hydrogen storage of AlH3. This air-milling method is also effective for other active catalysts toward both reducing the decomposition temperature and increasing the available hydrogen capacity of AlH3.

9.
Nanomaterials (Basel) ; 12(8)2022 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-35458031

RESUMO

Compared with the polycrystalline system, the single-crystalline ternary cathode material has better cycle stability because the only primary particles without grain boundaries effectively alleviate the formation of micro/nanocracks and retain better structural integrity. Therefore, it has received extensive research attention. There is no consistent result whether tungsten oxide acts as doping and/or coating from the surface modification of the polycrystalline system. Meanwhile, there is no report on the surface modification of the single-crystalline system by tungsten oxide. In this paper, multirole surface modification of single-crystalline nickel-rich ternary cathode material LiNi0.6Co0.2Mn0.2O2 by WO3 is studied by a simple method of adding WO3 followed by calcination. The results show that with the change in the amount of WO3 added, single-crystalline nickel-rich ternary cathode material can be separately doped, separately coated, and both doped and coated. Either doping or coating effectively enhances the structural stability, reduces the polarization of the material, and improves the lithium-ion diffusion kinetics, thus improving the cycle stability and rate performance of the battery. Interestingly, both doping and coating (for SC-NCM622-0.5%WO3) do not show a more excellent synergistic effect, while the single coating (for SC-NCM622-1.0%WO3) after eliminating the rock-salt phase layer performs the most excellent modification effect.

10.
Macromol Rapid Commun ; 43(22): e2200199, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35380177

RESUMO

Although optical engineering strategy has been utilized to optimize average visible transmittance (AVT) of semi-transparent organic solar cells (ST-OSCs), judicious selection of active layer materials should be more direct and basic. Herein, an efficient ternary active layer is constructed with a wide bandgap (3.0 eV) fluorescent polymer FC-S1 as host donor, a middle bandgap polymer PM6 as guest donor, and a narrow bandgap non-fullerene Y6-BO as acceptor. Using FC-S1 as the host donor can allow more visible photons to penetrate the device. In the absence of optical engineering, the ternary ST-OSC with FC-S1:PM6:Y6-BO = 1:0.3:1.5 active layer of 30 nm thickness displays a much higher AVT of 49.28% than that of 32.34% for a PM6:Y6-BO = 1.3:1.5 based binary ST-OSC. The ternary ST-OSC provides a good power conversion efficiency of 6.01%, only slightly lower than 7.15% for the binary ST-OSC. The ternary ST-OSC also demonstrates a color rendering index (CRI) of 87 and a correlated color temperature (CCT) of 6916 K, all better than CRI of 80 and CCT of 9022 K for the binary ST-OSC. Moreover, the backbone of FC-S1 is mainly composed by fluorene and carbazole, two easily-accessible aromatic rings, which would meet low-cost concern of ST-OSCs.


Assuntos
Corantes , Polímeros , Temperatura , Engenharia
11.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 34(1): 54-58, 2022 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-35307061

RESUMO

OBJECTIVE: To investigate the role and mechanism of microRNA-499 (miR-499) regulating α-myosin heavy chain (α-MHC) and ß-myosin heavy chain (ß-MHC) gene axis in septic myocardial dysfunction (SMD) and its significance. METHODS: Sixty healthy adult male Sprague-Dawley (SD) rats were divided into phosphate buffered saline (PBS) control group (PBS group), lipopolysaccharide (LPS) induced SMD model group (LPS group), miR-499 agonist pretreatment group (agomir+LPS group), and miR-499 inhibitor pretreatment group (antagomir+LPS group) by random number table, with 15 rats in each group. SMD rat model was reproduced by intraperitoneal injection of LPS 10 mg/kg. The PBS group was intraperitoneally injected with the same amount of PBS. The two pretreatment groups were injected with agomir 30 mg/kg or antagomir 80 mg/kg through the caudal vein for 3 days, once a day. PBS group and LPS group were not pretreated. Echocardiography was detected 5 hours after LPS injection, and relevant indexes were recorded. The expression of miR-499 in plasma and myocardial tissue was detected by real-time quantitative polymerase chain reaction (qPCR). Western blotting was used to detect the protein expressions of α-MHC and ß-MHC in myocardial tissue. Plasma N-terminal pro-brain natriuretic peptide (NT-proBNP), a marker of heart failure, was measured by electrochemiluminescence. RESULTS: Compared with the PBS group, the rats in LPS group were depressed. Additionally, LPS down-regulated the level of miR-499 in plasma and myocardial tissue, decreased α-MHC expression in myocardial tissue and up-regulated the expression of ß-MHC. Echocardiography showed that left ventricular ejection fraction (LVEF), left ventricle fractional shortening (LVFS), cardiac output (CO), stroke volume (SV) and heart rate (HR) decreased by 49.1%, 59.2%, 48.8%, 39.4% and 15.9%, respectively, and the level of plasma NT-proBNP increased significantly in LPS group, indicating that LPS could induce cardiac dysfunction in rats. Compared with the LPS group, after pretreatment with agomir to overexpress the miR-499, LVEF and LVFS were significantly increased [LVEF: 0.662±0.020 vs. 0.323±0.024, LVFS: (36.16±1.43)% vs. (20.20±1.32)%, both P < 0.01], which suggested that the cardiac function of rats was improved in agomir+LPS group. At the same time, pretreatment with agomir significantly down-regulated the ß-MHC protein expression (ß-MHC/GAPDH: 0.74±0.04 vs. 2.97±0.34, P < 0.01), significantly up-regulated α-MHC protein expression (α-MHC/GAPDH: 1.59±0.05 vs. 0.74±0.14, P < 0.01), and significantly decreased the plasma NT-proBNP level (ng/L: 114.49±6.85 vs. 334.13±4.36, P < 0.01). After pretreatment with antagomir to inhibit the expression of miR-499, echocardiography showed that LVEF and LVFS were significantly lower than those in the LPS group [LVEF: 0.297±0.021 vs. 0.323±0.024, LVFS: (19.38±1.52)% vs. (21.20±1.32)%, both P < 0.01], which suggested that the cardiac function of rats was significantly inhibited. At the same time, pretreatment with antagomir significantly down-regulated α-MHC protein expression in myocardial tissue (α-MHC/GAPDH: 0.63±0.03 vs. 0.74±0.14, P < 0.01), significantly up-regulated ß-MHC protein expression (ß-MHC/GAPDH: 3.03±0.47 vs. 2.97±0.34, P < 0.01), and significantly increased the level of plasma NT-proBNP (ng/L: 373.91±4.23 vs. 334.13±4.36, P < 0.05). CONCLUSIONS: miR-499 could regulate the expression of α-MHC and ß-MHC which improved cardiac dysfunction caused by sepsis. Targeted regulation of miR-499 expression may be an effective way to treat SMD.


Assuntos
MicroRNAs , Cadeias Pesadas de Miosina , Animais , Masculino , MicroRNAs/metabolismo , Ratos , Ratos Sprague-Dawley , Volume Sistólico , Função Ventricular Esquerda
12.
J Food Sci ; 86(12): 5318-5328, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34796506

RESUMO

Fish myofibrillar protein is underutilized due to the formation of insoluble aggregates in low salt media. High pressure homogenization (HPH) at 20, 40, and 60 MPa for four passes was applied on bighead carp myofibrillar protein in order to modify its structure and interfacial properties. Changes in aggregation, conformation, solubility, emulsifying and foaming properties of myofibrillar protein were investigated. The aggregates of myofibrillar protein were obviously disrupted by HPH treatment. The size of myofibrillar protein aggregates became smaller and more uniform as the treating pressure increased, accompanied by notable decreases of cross-sectional height and Rq value in AFM image. Furthermore, the conformation of HPH-treated myofibrillar protein was unfolded into a flexible and open structure. α-helix and ß-sheet were converted into ß-turn and random coil. Surface hydrophobicity and zeta potential were strengthened, along with the exposure of sulfhydryl groups onto molecule surface. On the other hand, solubility, emulsifying activity index (EAI) and foaming capacity (FC) of HPH-treated myofibrillar protein were markedly enhanced with the increasing pressure. Especially after HPH treatment at 60 MPa, myofibrillar protein was almost dissolved in low salt media (solubility 91.86%) with 4.92 fold for EAI and 3.52 fold for FC. But there was little variation in emulsifying and foaming stabilities. These results suggested that HPH treatment has interesting potential to induce the dissociation and unfolding of myofibrillar protein in low salt media, therefore improving its interfacial properties. PRACTICAL APPLICATION: Carp myofibrillar protein was treated by high pressure homogenization (HPH). Aggregates of myofibrillar protein were disrupted into smaller size form. Conformation of myofibrillar protein was unfolded into open and loose structure. Emulsifying and foaming capacities of myofibrillar protein were improved. HPH treatment modified the structure and interfacial properties of myofibrillar protein.


Assuntos
Carpas , Animais , Estudos Transversais
13.
Front Chem ; 9: 775537, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34722466

RESUMO

Mg-Li alloy possesses a high hydrogen capacity. However, the hydrogenation and dehydrogenation performances are still far from practical application. In this work, Mg2Si (MS) and graphene (G) were employed together to synergistically improve the hydrogen storage properties of Mg-Li alloy. The structures of the samples were studied by XRD and SEM methods. The hydrogen storage performances of the samples were studied by nonisothermal and isothermal hydrogenation and dehydrogenation, thermal analysis, respectively. It is shown that the onset dehydrogenation temperature of Mg-Li alloy was synergistically reduced from 360°C to 310°C after co-addition of Mg2Si and graphene. At a constant temperature of 325°C, the Mg-Li-MS-G composite can release 2.7 wt.% of hydrogen within 2 h, while only 0.2 wt.% of hydrogen is released for the undoped Mg-Li alloy. The hydrogenation activation energy of the Mg-Li-MS-G composite was calculated to be 86.5 kJ mol-1. Microstructure and hydrogen storage properties studies show that graphene can act as a grinding aid during the ball milling process, which leads to a smaller particle size for the composites. This work demonstrates that coaddition of Mg2Si and graphene can synergistically improve the hydrogen storage properties of Mg-Si alloy and offers an insight into the role of graphene in the Mg-Li-MS-G composite.

14.
iScience ; 24(5): 102423, 2021 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-33997701

RESUMO

Serine-arginine (SR) protein kinases (SRPKs) regulate the functions of the SR-rich splicing factors by phosphorylating multiple serines within their C-terminal arginine-serine-rich domains. Dysregulation of these phosphorylation events has been implicated in many diseases, suggesting SRPKs are potential therapeutic targets. In particular, aberrant SRPK1 expression alters the balances of proangiogenic (VEGF165) and antiangiogenic (VEGF165b) splicing isoforms of the key angiogenesis factor, vascular endothelial growth factor (VEGF), through the phosphorylation of prototypic SR protein SRSF1. Here, we report a protein-protein interaction (PPI) inhibitor of SRPKs, docking blocker of SRPK1 (DBS1), that specifically blocks a conserved substrate docking groove unique to SRPKs. DBS1 is a cell-permeable inhibitor that effectively inhibits the binding and phosphorylation of SRSF1 and subsequently switches VEGF splicing from the proangiogenic to the antiangiogenic isoform. Our findings thus provide a new direction for the development of SRPK inhibitors through targeting a unique PPI site to combat angiogenic diseases.

15.
ACS Appl Mater Interfaces ; 13(11): 13235-13247, 2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33720702

RESUMO

Two-dimensional vanadium carbide (V2C) and titanium carbide (Ti3C2) MXenes were first synthesized by exfoliating V2AlC or Ti3AlC2 and then introduced jointly into magnesium hydride (MgH2) to tailor the hydrogen desorption/absorption performances of MgH2. The as-prepared MgH2-V2C-Ti3C2 composites show much better hydrogen storage performances than pure MgH2. MgH2 with addition of 10 wt % of 2V2C/Ti3C2 initiates hydrogen desorption at around 180 °C; 5.1 wt % of hydrogen was desorbed within 60 min at 225 °C, while 5.8 wt % was desorbed within 2 min at 300 °C. Under 6 MPa H2, the dehydrided MgH2-2V2C/Ti3C2 can start to recover hydrogen at room temperature, and 5.1 wt % of H2 is obtained within 20 s at a constant temperature of 40 °C. The reversible capacity (6.3 wt %) does not decline for up to 10 cycles, which shows excellent cycling stability. The addition of 2V2C/Ti3C2 can remarkably lower the activation energy for the hydrogen desorption reaction of MgH2 by 37% and slightly reduce the hydrogen desorption reaction enthalpy by 2 kJ mol-1 H2. It was demonstrated that the combination of V2C and Ti3C2 promotes the hydrogen-releasing process of MgH2 compared with addition of only V2C or Ti3C2, while Ti3C2 impacts MgH2 more significantly than V2C in the hydrogen absorption process of MgH2 at ambient temperatures. A possible mechanism in the hydrogen release and uptake of the MgH2-V2C-Ti3C2 system was proposed as follows: hydrogen atoms or molecules may preferentially transfer through the MgH2/V2C/Ti3C2 triple-grain boundaries during the desorption process and through the Mg/Ti3C2 interfaces during the absorption process. Microstructure studies indicated that V2C and Ti3C2 mainly act as efficient catalysts for MgH2. This work provides an insight into the hydrogen storage behaviors and mechanisms of MgH2 boosted by a combination of two MXenes.

16.
Proc Natl Acad Sci U S A ; 118(9)2021 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-33627407

RESUMO

Anticytotoxic T lymphocyte-associated protein 4 (CTLA4) antibodies have shown potent antitumor activity, but systemic immune activation leads to severe immune-related adverse events, limiting clinical usage. We developed novel, conditionally active biologic (CAB) anti-CTLA4 antibodies that are active only in the acidic tumor microenvironment. In healthy tissue, this binding is reversibly inhibited by a novel mechanism using physiological chemicals as protein-associated chemical switches (PaCS). No enzymes or potentially immunogenic covalent modifications to the antibody are required for activation in the tumor. The novel anti-CTLA4 antibodies show similar efficacy in animal models compared to an analog of a marketed anti-CTLA4 biologic, but have markedly reduced toxicity in nonhuman primates (in combination with an anti-PD1 checkpoint inhibitor), indicating a widened therapeutic index (TI). The PaCS encompass mechanisms that are applicable to a wide array of antibody formats (e.g., ADC, bispecifics) and antigens. Examples shown here include antibodies to EpCAM, Her2, Nectin4, CD73, and CD3. Existing antibodies can be engineered readily to be made sensitive to PaCS, and the inhibitory activity can be optimized for each antigen's varying expression level and tissue distribution. PaCS can modulate diverse physiological molecular interactions and are applicable to various pathologic conditions, enabling differential CAB antibody activities in normal versus disease microenvironments.


Assuntos
Anticorpos Monoclonais Humanizados/farmacologia , Anticorpos Monoclonais/farmacologia , Anticorpos Antineoplásicos/farmacologia , Antígeno B7-H1/antagonistas & inibidores , Antígeno CTLA-4/antagonistas & inibidores , Neoplasias do Colo/terapia , Imunoterapia/métodos , 5'-Nucleotidase/antagonistas & inibidores , 5'-Nucleotidase/genética , 5'-Nucleotidase/imunologia , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais Humanizados/química , Anticorpos Antineoplásicos/química , Antígeno B7-H1/genética , Antígeno B7-H1/imunologia , Bicarbonatos/química , Complexo CD3/antagonistas & inibidores , Complexo CD3/genética , Complexo CD3/imunologia , Antígeno CTLA-4/genética , Antígeno CTLA-4/imunologia , Moléculas de Adesão Celular/antagonistas & inibidores , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/imunologia , Neoplasias do Colo/genética , Neoplasias do Colo/imunologia , Neoplasias do Colo/patologia , Molécula de Adesão da Célula Epitelial/antagonistas & inibidores , Molécula de Adesão da Célula Epitelial/genética , Molécula de Adesão da Célula Epitelial/imunologia , Proteínas Ligadas por GPI/antagonistas & inibidores , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/imunologia , Expressão Gênica , Humanos , Sulfeto de Hidrogênio/química , Concentração de Íons de Hidrogênio , Macaca fascicularis , Camundongos , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/imunologia , Engenharia de Proteínas/métodos , Receptor ErbB-2/antagonistas & inibidores , Receptor ErbB-2/genética , Receptor ErbB-2/imunologia , Linfócitos T Citotóxicos/efeitos dos fármacos , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/patologia , Carga Tumoral/efeitos dos fármacos , Microambiente Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
17.
J Sci Food Agric ; 101(9): 3723-3731, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33305370

RESUMO

BACKGROUND: Gardenia (Gardenia jasminoides Ellis) husk rich in dietary fiber is a byproduct of fructus processing, and commonly discarded as waste. The husk was fractionated by sequential extraction into four fractions: water-soluble fiber (W-SF), acid-soluble fiber (Ac-SF), alkali-soluble fiber (Al-SF) and insoluble residue fiber (IRF). The aim of this study was to investigate the differences in structure and in vitro hypoglycemic effect of these fibers. RESULTS: Monosaccharide composition and Fourier transform infrared spectra showed that the major component might be pectin for W-SF and Ac-SF, xylan as well as pectin for Al-SF and cellulose for IRF. These fibers offered excellent water-holding capacity and swelling capacity, except that IRF was only slightly swellable in water. W-SF exhibited significantly higher capacities to adsorb glucose (2.408 mmol g-1 at a glucose concentration of 200 mmol L-1 ) and inhibit α-amylase activity (29.48-49.45% inhibition rate at a concentration of 4-8 mg mL-1 ), probably caused by the higher viscosity and hydration properties; while Ac-SF, Al-SF and IRF (especially Al-SF) were more effective in retarding the glucose diffusion across a dialysis membrane (34.97-41.67% at 20-30 min), which might be attributed to particle size and specific surface area. All the fibers could quench the intrinsic fluorescence of α-amylase to some degree. CONCLUSIONS: Dietary fiber from gardenia husk, especially W-SF, can be used as a potential hypoglycemic ingredient in diabetic functional foods. © 2020 Society of Chemical Industry.


Assuntos
Fibras na Dieta/análise , Gardenia/química , Hipoglicemiantes/química , Extratos Vegetais/química , Diálise , Glucose/química , Pectinas/química , Viscosidade , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/química
18.
Front Chem ; 8: 207, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32266219

RESUMO

To improve the hydrogen storage properties of Mg/MgH2, a Ni and TiO2 co-doped reduced graphene oxide [(Ni-TiO2)@rGO] nanocomposite is synthesized by a facile impregnation method and introduced into Mg via ball milling. The results demonstrated that the dispersive distribution of Ni and TiO2 with a particle size of 20-200 nm in the reduced graphene oxide matrix led to superior catalytic effects on the hydrogen storage properties of Mg-(Ni-TiO2)@rGO. The initial hydrogenation/dehydrogenation temperature for Mg-(Ni-TiO2)@rGO decreased to 323/479 K, 75/84 K lower than that of the additive-free sample. The hydrogen desorption capacity of the Mg-(Ni-TiO2)@rGO composite released 1.47 wt.% within 120 min at 498 K. When the temperature was increased to 523 K, the hydrogen desorption capacity increased to 4.30 wt.% within 30 min. A hydrogenation/dehydrogenation apparent activation energy of 47.0/99.3 kJ·mol-1 was obtained for the Mg-(Ni-TiO2)@rGO composite. The improvement in hydrogenation and dehydrogenation for the Mg-(Ni-TiO2)@rGO composite was due to the reduction of the apparent activation energy by the catalytic action of (Ni-TiO2)@rGO.

19.
Med Sci Monit ; 25: 6034-6042, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31407674

RESUMO

BACKGROUND This study aimed to determine the association between CD4-positive T-helper (Th) cell subsets, T-helper 1 (Th1) and T-helper 2 (Th2) in patients with acute myocardial infarction (AMI) and the severity of coronary artery disease (CAD) determined by coronary artery angiography. MATERIAL AND METHODS Three groups of patients with AMI who underwent coronary angiography and percutaneous coronary intervention (PCI) included patients with stable CAD (n=35), ST-segment elevation myocardial infarction (STEMI) (n=30), and non-STEMI (NSTEMI) (n=35), and controls (n=33). Measurement of high-sensitivity cardiac troponin T (hs-cTnT) was performed. The numbers of circulating CD4-positive Th1 and Th2 cells were measured using flow cytometry. Plasma levels of interferon-γ (IFN-γ) and interleukin-4 (IL-4) were measured using enzyme-linked immunosorbent assay (ELISA). RESULTS An increase in the Th1 lymphocyte population was associated with more CAD, and an increased Th1/Th2 ratio was found in patients with NSTEMI and STEMI (controls 7.27±2.98; stable CAD 7.58±2.52; NSTEMI 16.62±2.74; and STEMI 22.32±7.35) (P<0.001). The proportion of Th1 cells and the Th1/Th2 ratio increased as the number of affected arteries, the degree of stenosis, and the lesion length increased. At a median follow-up of 18.2 months, patients with CAD and an increased Th1/Th2 ratio had a significant increase in adverse cardiac events compared with patients with a reduced Th1/Th2 ratio (log-rank, P=0.042). CONCLUSIONS An increased ratio of circulating Th1 to Th2 cells in patients with AMI was associated with the severity of CAD determined by angiography.


Assuntos
Doença da Artéria Coronariana/imunologia , Infarto do Miocárdio/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Idoso , China , Angiografia Coronária/métodos , Doença da Artéria Coronariana/sangue , Vasos Coronários/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/complicações , Intervenção Coronária Percutânea , Estudos Prospectivos , Infarto do Miocárdio com Supradesnível do Segmento ST , Índice de Gravidade de Doença , Células Th1/imunologia , Células Th2/imunologia
20.
Toxicology ; 419: 55-64, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30905827

RESUMO

Lead is widely distributed in the environment and has become a global public health issue. It is well known that lead exposure induces not only neurodevelopmental toxicity but also neurodegenerative diseases, with learning and memory impairment in the later stage. However, the molecular mechanisms remain elusive. The present study investigated the effects of early life and lifetime lead exposure on cognition and identified the molecular mechanisms involved in aged rats. The results herein demonstrated that the lead concentration in peripheral blood and brain tissues in aged rats was significantly increased in a lead dose-dependent manner. High-dose lead exposure caused cognitive functional impairment in aged rats, concomitant with a longer escape latency and a lower frequency of crossing the platform via Morris water maze testing compared to those in the control and low-dose lead exposure groups. Importantly, neuron functional defects were still observed even in early life lead exposure during the prenatal and weaning periods in aged rats. The neurotoxicity induced by lead exposure was morphologically evidenced by a recessed nuclear membrane, a swollen endoplasmic reticulum, and mitochondria in the neurons. Mechanistically, the exposure of aged rats to lead resulted in increasing free calcium concentration, reactive oxygen species, and apoptosis in the hippocampal neurons. Lead exposure increased RyR3 expression and decreased the levels of p-CaMKIIα/CaMKIIα and p-CREB/CREB in the hippocampus of aged rats. These findings indicated that early life lead exposure-induced cognition disorder was irreversible in aged rats. Lead-induced neurotoxicity might be related to the upregulation of RyR3 expression and high levels of intracellular free calcium with increasing lead concentration in injured neurons.


Assuntos
Comportamento Animal , Sinalização do Cálcio , Cognição , Disfunção Cognitiva/metabolismo , Hipocampo/metabolismo , Intoxicação do Sistema Nervoso por Chumbo em Adultos/metabolismo , Neurônios/metabolismo , Compostos Organometálicos , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Fatores Etários , Animais , Apoptose , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Disfunção Cognitiva/induzido quimicamente , Disfunção Cognitiva/fisiopatologia , Disfunção Cognitiva/psicologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Modelos Animais de Doenças , Reação de Fuga , Feminino , Hipocampo/patologia , Hipocampo/fisiopatologia , Intoxicação do Sistema Nervoso por Chumbo em Adultos/fisiopatologia , Intoxicação do Sistema Nervoso por Chumbo em Adultos/psicologia , Masculino , Aprendizagem em Labirinto , Neurônios/patologia , Fosforilação , Ratos Sprague-Dawley , Tempo de Reação , Espécies Reativas de Oxigênio/metabolismo
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