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1.
Proc Natl Acad Sci U S A ; 121(16): e2315541121, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38598341

RESUMO

Ferroptosis is an iron-dependent type of regulated cell death resulting from extensive lipid peroxidation and plays a critical role in various physiological and pathological processes. However, the regulatory mechanisms for ferroptosis sensitivity remain incompletely understood. Here, we report that homozygous deletion of Usp8 (ubiquitin-specific protease 8) in intestinal epithelial cells (IECs) leads to architectural changes in the colonic epithelium and shortens mouse lifespan accompanied by increased IEC death and signs of lipid peroxidation. However, mice with heterozygous deletion of Usp8 in IECs display normal phenotype and become resistant to azoxymethane/dextran sodium sulfate-induced colorectal tumorigenesis. Mechanistically, USP8 interacts with and deubiquitinates glutathione peroxidase 4 (GPX4), leading to GPX4 stabilization. Thus, USP8 inhibition destabilizes GPX4 and sensitizes cancer cells to ferroptosis in vitro. Notably, USP8 inhibition in combination with ferroptosis inducers retards tumor growth and enhances CD8+ T cell infiltration, which potentiates tumor response to anti-PD-1 immunotherapy in vivo. These findings uncover that USP8 counteracts ferroptosis by stabilizing GPX4 and highlight targeting USP8 as a potential therapeutic strategy to boost ferroptosis for enhancing cancer immunotherapy.


Assuntos
Ferroptose , Neoplasias , Camundongos , Animais , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , Ferroptose/genética , Homozigoto , Deleção de Sequência , Peroxidação de Lipídeos , Homeostase , Neoplasias/genética , Neoplasias/terapia , Imunoterapia
2.
Brief Bioinform ; 23(1)2022 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-34607358

RESUMO

The discovery of cancer subtypes has become much-researched topic in oncology. Dividing cancer patients into subtypes can provide personalized treatments for heterogeneous patients. High-throughput technologies provide multiple omics data for cancer subtyping. Integration of multi-view data is used to identify cancer subtypes in many computational methods, which obtain different subtypes for the same cancer, even using the same multi-omics data. To a certain extent, these subtypes from distinct methods are related, which may have certain guiding significance for cancer subtyping. It is a challenge to effectively utilize the valuable information of distinct subtypes to produce more accurate and reliable subtypes. A weighted ensemble sparse latent representation (subtype-WESLR) is proposed to detect cancer subtypes on heterogeneous omics data. Using a weighted ensemble strategy to fuse base clustering obtained by distinct methods as prior knowledge, subtype-WESLR projects each sample feature profile from each data type to a common latent subspace while maintaining the local structure of the original sample feature space and consistency with the weighted ensemble and optimizes the common subspace by an iterative method to identify cancer subtypes. We conduct experiments on various synthetic datasets and eight public multi-view datasets from The Cancer Genome Atlas. The results demonstrate that subtype-WESLR is better than competing methods by utilizing the integration of base clustering of exist methods for more precise subtypes.


Assuntos
Algoritmos , Neoplasias , Análise por Conglomerados , Humanos , Neoplasias/genética
3.
BMC Ophthalmol ; 24(1): 155, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38594682

RESUMO

INTRODUCTION: In recent years, insulin eye drops have attracted increasing attention from researchers and ophthalmologists. The aim of this study was to investigate the efficacy and possible mechanism of action of insulin eye drops in diabetic mice with corneal wounds. METHODS: A type 1 diabetes model was induced, and a corneal epithelial injury model of 2.5 mm was established. We used corneal fluorescein staining, hematoxylin-eosin (H-E) staining and the Cochet-Bonnet esthesiometer to examine the process of wound healing. Subsequently, the expression levels of Ki-67, IL-1ß, ß3-tubulin and neuropeptides, including substance P (SP) and calcitonin gene-related peptide (CGRP), were examined at 72 h after corneal injury. RESULTS: Fluorescein staining demonstrated an acceleration of the recovery of corneal epithelial injury in diabetic mice compared with the saline treatment, which was further evidenced by the overexpression of Ki-67. Moreover, 72 h of insulin application attenuated the expression of inflammatory cytokines and neutrophil infiltration. Remarkably, the results demonstrated that topical insulin treatment enhanced the density of corneal epithelial nerves, as well as neuropeptide SP and CGRP release, in the healing cornea via immunofluorescence staining. CONCLUSIONS: Our results indicated that insulin eye drops may accelerate corneal wound healing and decrease inflammatory responses in diabetic mice by promoting nerve regeneration and increasing levels of neuropeptides SP and CGRP.


Assuntos
Lesões da Córnea , Diabetes Mellitus Experimental , Epitélio Corneano , Ceratite , Camundongos , Animais , Epitélio Corneano/metabolismo , Insulina , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Soluções Oftálmicas , Antígeno Ki-67/metabolismo , Córnea/fisiologia , Lesões da Córnea/tratamento farmacológico , Cicatrização , Ceratite/metabolismo , Fluoresceína/metabolismo , Inflamação/metabolismo
4.
Microvasc Res ; 147: 104502, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36746363

RESUMO

The main pathological manifestation of coronary artery disease is myocardial injury caused by ischemia-reperfusion (IR) injury. Regular exercise reduces the risk of death during myocardial IR injury. The aim of this study was to describe the effects of various types of exercise on myocardial IR injury. Four electronic databases PubMed, Web of Science, Embase, and Cochrane Library were comprehensively searched from inception until February 2022, to identify studies relevant to the current review, using the method of combining subject and free words. Finally, 16 articles were included in the meta-analysis. Results showed that exercise training decreases the Myocardial infarct size compared to the control group (SMD = -2.6, 95 % CI [-3.53 to -1.67], P < 0.01); increasing the coronary blood flow (MD = 2.93, 95 % CI [2.41 to 3.44], P < 0.01), left ventricular developed pressure (SMD = 2.28, 95 % CI [0.12 to 4.43], P < 0.05), cardiac output (SMD = 1.22, 95 % CI [0.61 to 1.83], P < 0.01) compared to the control group. According to the descriptive analysis results also showed that exercise training increases the left ventricular ejection fraction, superoxide dismutase, manganese superoxide dismutase, glutathione peroxidase, copper-zinc superoxide dismutase, glutathione peroxidase, and decrease the creatine kinase, creatine kinase-MB, lactate dehydrogenase, Malondialdehyde, cardiac troponins T. Exercise can improve myocardial function after myocardial IR injury; however, further research is needed in combination with specific issues such as exercise mode, intensity, duration, and model issues.


Assuntos
Traumatismo por Reperfusão Miocárdica , Humanos , Traumatismo por Reperfusão Miocárdica/patologia , Volume Sistólico , Função Ventricular Esquerda , Superóxido Dismutase , Exercício Físico , Glutationa Peroxidase
5.
Chemistry ; 29(24): e202203979, 2023 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-36757279

RESUMO

The synthesis of self-assembly systems that can mimic partial biological behaviours require ingenious and delicate design. For decades, scientists are committed to exploring new base pairing patterns using hydrogen bonds directed self-assembly of nucleotides. A fundamental question is the adaptive circumstance of the recognition between base pairs, namely, how solvent conditions affect the domain of base pairs. Towards this question, three nucleotide complexes based on 2'-deoxycytidine-5'-monophosphate (dCMP) and cytidine-5'-monophosphate (CMP) were synthesized in different solvents and pH values, and an unusual cytosine-cytosine base paring pattern (named full C : C base pairing) has been successfully obtained. Systematic single crystal analysis and 1 H NMR titration spectra have been performed to explore factors influencing the formation of base paring patterns. Moreover, supramolecular chirality of three complexes were studied using circular dichroism (CD) spectroscopy in solution and solid-state combined with crystal structure analysis.


Assuntos
Citosina , Nucleotídeos , Citosina/química , Nucleotídeos/química , Pareamento de Bases , Monofosfato de Citidina
6.
Biomacromolecules ; 24(9): 4240-4252, 2023 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-37585281

RESUMO

Bionic mimics using natural cartilage matrix molecules can modulate the corresponding metabolic activity by improving the microenvironment of chondrocytes. A bionic brush polymer, HA/PX, has been found to reverse the loss of cartilage extracellular matrix (ECM) and has promising applications in the clinical treatment of osteoarthritis (OA). However, the unknown bioremediation mechanism of HA/PX severely hinders its clinical translation. In OA, the massive loss of the ECM may be attributed to a decrease in transient receptor potential vanilloid 4 (TRPV4) activity, which affects reactive oxygen species (ROS) clearance and [Ca2+]i signaling, initiating downstream catabolic pathways. In this study, we investigated the bioremediation mechanism of HA/PX in a model of interleukin 1ß (IL-1ß)-induced inflammation. Through TRPV4, HA/PX reduced ROS accumulation in chondrocytes and enhanced [Ca2+]i signaling, reflecting a short-term protection capacity for chondrocytes. In addition, HA/PX balanced the metabolic homeostasis of chondrocytes via TRPV4, including promoting the secretion of type II collagen (Col-II) and aggrecan, the major components of the ECM, and reducing the expression of matrix metal-degrading enzyme (MMP-13), exerting long-term protective effects on chondrocytes. Molecular dynamics (MD) simulations showed that HA/PX could act as a TRPV4 activator. Our results suggest that HA/PX can regulate chondrocyte homeostasis via ROS/Ca2+/TRPV4, thereby improving cartilage regeneration. Because the ECM is a prevalent feature of various cell types, HA/PX holds promising potential for improving regeneration and disease modification for not only cartilage-related healthcare but many other tissues and diseases.


Assuntos
Antineoplásicos , Cartilagem Articular , Osteoartrite , Humanos , Condrócitos/metabolismo , Ácido Hialurônico/farmacologia , Canais de Cátion TRPV/metabolismo , Canais de Cátion TRPV/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Biomimética , Osteoartrite/tratamento farmacológico , Interleucina-1beta/metabolismo , Antineoplásicos/farmacologia , Homeostase , Cartilagem Articular/metabolismo , Células Cultivadas
7.
Surg Endosc ; 37(5): 3567-3579, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36624217

RESUMO

BACKGROUND: Postoperative pancreatic fistula (POPF) is often associated with significant morbidity and mortality after the Whipple operation. Patient-related factors associated with POPF include soft pancreatic texture and a small main pancreatic duct (MPD). The traditional duct-to-mucosa anastomosis was modified to be easily performed. The aim of the study was to evaluate the simplified pancreaticojejunostomy (PJ) method in the prevention of POPF after minimally invasive pancreaticoduodenectomy (PD). METHODS: Ninety-eight patients who underwent laparoscopic pancreaticoduodenectomy (LPD) and robotic pancreaticoduodenectomy (RPD) with a simplified PJ procedure containing only two duct-to-mucosa sutures and four penetrating-sutures to anastomose the pancreatic parenchyma and jejunal seromuscular layer in our center were retrospectively studied. Demographics and clinical short-term safety were assessed. RESULTS: All LPD and RPD procedures were successfully performed. The median time of PJ was 17 min, and the median blood loss was 60 mL, with only one patient requiring transfusion. Four patients (4.1%) suffered from clinically relevant POPF (CR-POPF), including four grade B cases and no grade C cases. For patients with an MPD diameter of 3 mm or less, POPF was noted in two (4%) of the fifty patients, with all cases being grade B. Of the patients with a soft pancreas, only two (4.5%) patients suffered from grade B POPF. One patient (1.0%) experienced a 90-day mortality. Neither the main pancreatic diameter nor pancreatic texture had an impact on postoperative outcomes. CONCLUSIONS: Our technique is a simple, safe and efficient alternative to prevent POPF after LPD and RPD. This method is suitable for almost all pancreatic conditions, including cases with a small main pancreatic duct and soft pancreas, and has the potential to become the preferred procedure in low-volume pancreatic surgery centers. Our modified duct-to-mucosa PJ, which contains only two duct-to-mucosa sutures and four penetrating-sutures to anastomose the pancreatic parenchyma and jejunal seromuscular layer, is ideal for small MPD and soft pancreas when performing minimally invasive PD and has a low rate of POPF. PJ pancreaticojejunostomy, MPD main pancreatic diameter, PD pancreaticoduodenectomy, POPF postoperative pancreatic fistula.


Assuntos
Pancreaticoduodenectomia , Pancreaticojejunostomia , Humanos , Pancreaticojejunostomia/métodos , Pancreaticoduodenectomia/métodos , Fístula Pancreática/etiologia , Fístula Pancreática/prevenção & controle , Fístula Pancreática/cirurgia , Estudos Retrospectivos , Pâncreas/cirurgia , Ductos Pancreáticos/cirurgia , Anastomose Cirúrgica/métodos , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Complicações Pós-Operatórias/cirurgia , Mucosa
8.
BMC Musculoskelet Disord ; 24(1): 567, 2023 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-37434207

RESUMO

BACKGROUND: Femoral offset (FO) restoration plays an important role in improving the prognosis and quality of life of patients undergoing hip replacement. However, it is not given enough attention in revisions among patients with periprosthetic femoral fractures (PPFFs); instead, more attention is given to reduction, fixation of fractures and stabilizing prostheses. The primary objective of this study was to evaluate the effect of FO restoration on the function of the hip joint in revisions of patients with PPFF of Vancouver B2. Moreover, we studied whether there is a difference in FO restoration between modular and nonmodular stems. METHODS: A retrospective review of 20 patients with PPFF of Vancouver B2 revised with a tapered fluted modular titanium stem and 22 patients with PPFF of Vancouver B2 revised with a tapered fluted nonmodular titanium stem from 2016 to 2021 was conducted. Based on the difference between the FO of the affected side and that of the healthy side, 26 patients were allocated into Group A (difference ≤ 4 mm), and 16 patients were allocated into Group B (difference > 4 mm). The postoperative Harris Hip Score (HHS), range of motion of the hip joint, length of both lower limbs and dislocation were compared between Group A and Group B. The proportions of patients with FO restoration (difference ≤ 4 mm) and stem subsidence were compared between the modular and nonmodular groups. RESULTS: The mean follow-up time was 34.3 ± 17.3 months, and all cases achieved fracture healing at the last visit. Patients in Group A had a higher HHS, larger range of abduction, fewer dislocations and less limb length discrepancy (LLD). Patients in the modular group had a higher proportion of FO restoration and less subsidence. CONCLUSION: FO restoration improves postoperative hip joint function and reduces dislocation and LLD in revisions of patients with PPFF of Vancouver B2. Compared with nonmodular prostheses, modular prostheses tend to be easier for FO restoration under complex circumstances.


Assuntos
Fraturas do Fêmur , Luxações Articulares , Humanos , Estudos Retrospectivos , Qualidade de Vida , Titânio , Fraturas do Fêmur/diagnóstico por imagem , Fraturas do Fêmur/cirurgia , Fêmur
9.
BMC Musculoskelet Disord ; 24(1): 113, 2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36765290

RESUMO

BACKGROUND: Bone mineral density (BMD) alterations in response to multivitamin exposure were rarely studied. Our study assessed the association of coexposure to six types of vitamins (i.e., vitamins B12, B9, C, D, A and E) with BMD measurements in adults in the US. METHODS: Data were collected from participants aged ≥ 20 years (n = 2757) in the U.S. National Health and Nutrition Examination Surveys (NHANES) from 2005 to 2006. Multiple linear regression, restricted cubic splines, principal component analysis (PCA) and weighted quantile sum (WQS) regression were performed for statistical analysis. RESULTS: The circulating levels of vitamins B12 and C were positively associated with BMDs, and an inverted L-shaped exposure relationship was observed between serum vitamin C and BMDs. PCA identified two principal components: one for 'water-soluble vitamins', including vitamins B12, B9 and C, and one for 'fat-soluble vitamins', including vitamins A, D and E. The former was positively associated with total femur (ß = 0.009, 95%CI: 0.004, 0.015) and femoral neck (ß = 0.007, 95%CI: 0.002, 0.013) BMDs, and the latter was negatively associated with BMDs with non-statistical significance. The WQS index constructed for the six vitamins was significantly related to total femur (ß = 0.010, 95%CI: 0.001, 0.018) and femoral neck (ß = 0.008, 95%CI: 0.001, 0.015) BMDs, and vitamins B12 and C weighted the most. The WQS index was inversely related to BMDs with non-statistical significance, and vitamins E and A weighted the most. CONCLUSION: Our findings suggested a positive association between water-soluble vitamin coexposure and BMD, and the association was mainly driven by vitamins B12 and C. Negative association between fat-soluble vitamin coexposure and BMD was indicated, mainly driven by vitamins E and A. An inverted L-shaped exposure relationship was found between vitamin C and BMD.


Assuntos
Densidade Óssea , Vitaminas , Adulto , Humanos , Densidade Óssea/fisiologia , Inquéritos Nutricionais , Estudos Transversais , Ácido Ascórbico , Água
10.
Hepatobiliary Pancreat Dis Int ; 22(6): 622-631, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36335030

RESUMO

BACKGROUND: Improving the mechanical properties and angiogenesis of acellular scaffolds before transplantation is an important challenge facing the development of acellular liver grafts. The present study aimed to evaluate the cytotoxicity and angiogenesis of polyethylene glycol (PEG) crosslinked decellularized single liver lobe scaffolds (DLSs), and establish its suitability as a graft for long-term liver tissue engineering. METHODS: Using mercaptoacrylate produced by the Michael addition reaction, DLSs were first modified using N-succinimidyl S-acetylthioacetate (SATA), followed by cross-linking with PEG as well as vascular endothelial growth factor (VEGF). The optimal concentration of agents and time of the individual steps were identified in this procedure through biomechanical testing and morphological analysis. Subsequently, human umbilical vein endothelial cells (HUVECs) were seeded on the PEG crosslinked scaffolds to detect the proliferation and viability of cells. The scaffolds were then transplanted into the subcutaneous tissue of Sprague-Dawley rats to evaluate angiogenesis. In addition, the average number of blood vessels was evaluated in the grafts with or without PEG at days 7, 14, and 21 after implantation. RESULTS: The PEG crosslinked DLS maintained their three-dimensional structure and were more translucent after decellularization than native DLS, which presented a denser and more porous network structure. The results for Young's modulus proved that the mechanical properties of 0.5 PEG crosslinked DLS were the best and close to that of native livers. The PEG-VEGF-DLS could better promote cell proliferation and differentiation of HUVECs compared with the groups without PEG cross-linking. Importantly, the average density of blood vessels was higher in the PEG-VEGF-DLS than that in other groups at days 7, 14, and 21 after implantation in vivo. CONCLUSIONS: The PEG crosslinked DLS with VEGF could improve the biomechanical properties of native DLS, and most importantly, their lack of cytotoxicity provides a new route to promote the proliferation of cells in vitro and angiogenesis in vivo in liver tissue engineering.


Assuntos
Alicerces Teciduais , Fator A de Crescimento do Endotélio Vascular , Ratos , Animais , Humanos , Alicerces Teciduais/química , Fator A de Crescimento do Endotélio Vascular/farmacologia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Polietilenoglicóis/farmacologia , Ratos Sprague-Dawley , Engenharia Tecidual/métodos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Fígado/cirurgia , Fígado/metabolismo
11.
Nano Lett ; 22(11): 4429-4436, 2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-35616710

RESUMO

Schottky diode is the fundamental building blocks for modern electronics and optoelectronics. Reducing the semiconductor layer thickness could shrink the vertical size of a Schottky diode, improving its speed and integration density. Here, we demonstrate a new approach to fabricate a Schottky diode with ultrashort physical length approaching atomic limit. By mechanically laminating prefabricated metal electrodes on both-sides of two-dimensional MoS2, the intrinsic metal-semiconductor interfaces can be well retained. As a result, we demonstrate the thinnest Schottky diode with a length of 2.6 nm and decent rectification behavior. Furthermore, with a diode length smaller than the semiconductor depletion length, the carrier transport mechanisms are investigated and explained by thickness-dependent and temperature-dependent electrical measurements. Our study not only pushes the scaling limit of a Schottky diode but also provides a general double-sided electrodes integration approach for other ultrathin vertical devices.

12.
Molecules ; 28(1)2023 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-36615583

RESUMO

Diabetes mellitus (DM) is a major risk factor for stroke and exacerbates white-matter damage in focal cerebral ischemia. Our previous study showed that the sigma-1 receptor agonist PRE084 ameliorates bilateral common-carotid-artery occlusion-induced brain damage in mice. However, whether this protective effect can extend to white matter remains unclear. In this study, C57BL/6 mice were treated with high-fat diets (HFDs) combined with streptozotocin (STZ) injection to mimic type 2 diabetes mellitus (T2DM). Focal cerebral ischemia in T2DM mice was established via injection of the vasoconstrictor peptide endothelin-1 (ET-1) into the hippocampus. Three different treatment plans were used in this study. In one plan, 1 mg/kg of PRE084 (intraperitoneally) was administered for 7 d before ET-1 injection; the mice were sacrificed 24 h after ET-1 injection. In another plan, PRE084 treatment was initiated 24 h after ET-1 injection and lasted for 7 d. In the third plan, PRE084 treatment was initiated 24 h after ET-1 injection and lasted for 21 d. The Y-maze, novel object recognition, and passive avoidance tests were used to assess neurobehavioral outcomes. We found no cognitive dysfunction or white-matter damage 24 h after ET-1 injection. However, 7 and 21 d after ET-1 injection, the mice showed significant cognitive impairment and white-matter damage. Only PRE084 treatment for 21 d could improve this white-matter injury; increase axon and myelin density; decrease demyelination; and increase the expressions of myelin regulator 2'-3'-cyclic nucleotide 3'-phosphodiesterase (CNpase) and myelin oligodendrocyte protein (MOG) (which was expressed by mature oligodendrocytes), the number of nerve/glial-antigen 2 (NG2)-positive cells, and the expression of platelet-derived growth factor receptor-alpha (PDGFRα), all of which were expressed by oligodendrocyte progenitor cells in mice with diabetes and focal cerebral ischemia. These results indicate that maybe there was more severe white-matter damage in the focal cerebral ischemia of the diabetic mice than in the mice with normal blood glucose levels. Long-term sigma-1 receptor activation may promote oligodendrogenesis and white-matter functional recovery in patients with stroke and with diabetes.


Assuntos
Isquemia Encefálica , Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Acidente Vascular Cerebral , Substância Branca , Camundongos , Animais , Substância Branca/metabolismo , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Camundongos Endogâmicos C57BL , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/metabolismo , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/metabolismo , Infarto Cerebral , Modelos Animais de Doenças , Receptor Sigma-1
13.
Angew Chem Int Ed Engl ; 62(9): e202216511, 2023 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-36625466

RESUMO

Prospects in light-driven water activation have prompted rapid progress in hydrogenation reactions. We describe a Ni2+ -N4 site built on carbon nitride for catalyzed semihydrogenation of alkynes, with water supplying protons, powered by visible-light irradiation. Importantly, the photocatalytic approach developed here enabled access to diverse deuterated alkenes in D2 O with excellent deuterium incorporation. Under visible-light irradiation, evolution of a four-coordinate Ni2+ species into a three-coordinate Ni+ species was spectroscopically identified. In combination with theoretical calculations, the photo-evolved Ni+ is posited as HO-Ni+ -N2 with an uncoordinated, protonated pyridinic nitrogen, formed by coupled Ni2+ reduction and water dissociation. The paired Ni-N prompts hydrogen liberation from water, and it renders desorption of alkene preferred over further hydrogenation to alkane, ensuring excellent semihydrogenation selectivity.

14.
Small ; 18(14): e2107104, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35174957

RESUMO

2D Semiconductors are promising in the development of next-generation photodetectors. However, the performances of 2D photodetectors are largely limited by their poor light absorption (due to ultrathin thickness) and small detection range (due to large bandgap). To overcome the limitations, a strain-plasmonic coupled 2D photodetector is designed by mechanically integrating monolayer MoS2 on top of prefabricated Au nanoparticle arrays. Within this structure, the large biaxial tensile strain can greatly reduce the MoS2 bandgap for broadband photodetection, and at the same time, the nanoparticles can significantly enhance the light intensity around MoS2 with much improved light absorption. Together, the strain-plasmonic coupled photodetector can broaden the detection range by 60 nm and increase the signal-to-noise ratio by 650%, representing the ultimate optimization of detection range and detection intensity at the same time. The strain-plasmonic coupling effect is further systematically characterized and confirmed by using Raman and photoluminescence spectrophotometry. Furthermore, the existence of built-in potential and photo-switching behavior is demonstrated between the strained and unstrained region, constructing a self-powered homojunction photodetector. This approach provides a simple strategy to couple strain effect and plasmonic effect, which can provide a new strategy for designing high-performance and broadband 2D optoelectronic devices.

15.
Mol Pharm ; 19(7): 2518-2534, 2022 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-35549267

RESUMO

Limited chemotherapeutic efficiency, drug resistance, and side effects are primary obstacles for cancer treatment. The development of co-delivery systems with synergistic treatment modes should be a promising strategy. Here, we fabricated a multifunctionalized nanocarrier with a combination of chemotherapeutic agents and gold nanoparticles (AuNPs), which could integrate chemo-photothermal therapy, thus enhancing overall anticancer efficacy, sensitizing drug-resistant cancer cells, and diminishing cancer stem cells (CSCs). To be specific, camptothecin nanocrystals (CPT NCs) were prepared as a platform, on the surface of which AuNPs were decorated and a hyaluronic acid layer acted as capping, stabilizing, targeting, and hydrophilic agents for CPT NCs, and reducing agents for AuNPs, providing a bridge connecting AuNPs to CPT. These AuNP-decorated CPT NCs exhibited good physico-chemical properties such as optimal sizes, payload, stability, and photothermal efficiency. Compared to other CPT formulations, they displayed considerably improved biocompatibility, selectivity, intracellular uptake, cytotoxicity, apoptosis induction activity, Pgp inhibitory capability, and anti-CSC activity, owing to a synergistic/cooperative effect from AuNPs, CPT, near-infrared treatment, pH/photothermal-triggered drug release, and nanoscaled structure. A mitochondrial-mediated signaling pathway is the underlying mechanism for cytotoxic and apoptotic effects from AuNP-decorated CPT NCs, in terms of mitochondrial dysfunction, intensified oxidative stress, DNA fragmentation, caspase 3 activation, upregulation of proapoptotic genes such as p53, Bax, and caspase 3, and lower levels of antiapoptotic Bcl-2.


Assuntos
Antineoplásicos , Nanopartículas Metálicas , Nanopartículas , Antineoplásicos/química , Antineoplásicos/farmacologia , Camptotecina/química , Camptotecina/farmacologia , Caspase 3 , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Resistência a Medicamentos , Ouro/química , Nanopartículas Metálicas/química , Nanopartículas/química , Fototerapia , Terapia Fototérmica
16.
Inorg Chem ; 61(2): 818-829, 2022 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-34856096

RESUMO

The conformation of the pentose ring in nucleotides is extremely important and a basic problem in biochemistry and pharmaceutical chemistry. In this study, we used a strategy to regulate the conformation of pentose rings of nucleotides via the synergistic effect of metal-ion coordination and π-π stacking. Seven types of coordination complexes were developed and characterized using Fourier transform infrared spectroscopy, elemental analysis, thermogravimetric analysis, powder X-ray diffraction, ultraviolet-visible spectroscopy, 1H nuclear magnetic resonance spectroscopy, electrospray ionization mass spectrometry, and single-crystal X-ray diffraction. On the basis of two conformational parameters obtained from single-crystal structure analysis, i.e., the pseudorotation phase angle and degree of puckering, the exact conformation of the furanose ring in these coordination polymers was unequivocally determined. Crystallographic studies demonstrate that a short bridging ligand (4,4'-bipyridine) is conducive to the formation of a twist form, and long auxiliary ligands [1,2-bis(4-pyridyl)ethene and 4,4'-azopyridine] induce the formation of an envelope conformation. However, the longest auxiliary ligands [1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene] cannot limit the flexibility of a nucleotide. Our results demonstrated that the proposed strategy is universal and controllable. Moreover, the chirality of these coordination polymers was examined by combining the explanation of their crystal structures with solid-state circular dichroism spectroscopy measurements.


Assuntos
Complexos de Coordenação
17.
Clin Invest Med ; 45(4): E25-32, 2022 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-36586104

RESUMO

PURPOSE: To investigate the value of anteroposterior-to-transverse ratio (ATR) and the effect on features of nodules in ultrasound (US) diagnosis of thyroid nodules in different locations.  Methods: The nodules were divided into three groups according to the different nodule location: isthmus group; upper and lower poles of bilobed thyroid group; and the middle of the bilobed thyroid group. The diameters of the nodules were recorded, and ATR of the nodule was calculated on the transverse and longitudinal sections. The transverse and the longitudinal sections of ATR of thyroid nodules in different groups were compared.  Result: The transverse section of ATR was significantly different among the three groups (p = 0.001). In addition, there are significant differences in many US features among three groups, including nodule composition, thyroid parenchyma, morphology, echogenicity, shape, calcifications, vascularity, nodule ACR TI-RADS and histopathologic (all p < 0.05). In the group of upper and lower poles of bilobed thyroid, significant difference was found between the transverse and the longitudinal section of ATR (p = 0.019). The cut-off values of transverse section and longitudinal section of ATR were 0.967 and 0.750, respectively.  Conclusion: The transverse section of ATR at different location of thyroid may be a predictor for malignancy with clinical diagnostic significance.


Assuntos
Neoplasias da Glândula Tireoide , Nódulo da Glândula Tireoide , Humanos , Nódulo da Glândula Tireoide/diagnóstico por imagem , Nódulo da Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/patologia , Estudos Retrospectivos , Ultrassonografia
18.
BMC Ophthalmol ; 22(1): 351, 2022 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-36031597

RESUMO

BACKGROUND: This study was performed to investigate the association between symptoms and signs in patients with meibomian gland dysfunction (MGD). METHODS: Data were obtained from 122 MGD patients who were recruited for intense pulsed light therapy from November 2017 to April 2018 and the severity of their symptoms and signs at baseline were observed and recorded. Spearman correlation analyses were performed to analyze the relationships between SPEED score and signs. Subjects were divided into different subgroups based on possible influencing factors, and the differences in symptoms and signs were compared between different subgroups. Then influencing factors were controlled by regression analysis to explore the relationship between symptoms and signs and the strong factors affecting symptoms and signs. RESULTS: Analysis of baseline data showed that SPEED scores were not correlated with TBUT, CFSS, MGYSS or any index of eyelid margin abnormality (p > 0.05). In addition, abnormalities of lid margins, including hyperemia, thickening, rounding, hyperkeratinization, and telangiectasia around orifices, were more likely to occur in older patients, menopausal patients, and patients living in northern China. Multiple linear regression analysis indicated that there was still no correlation between symptoms and signs (p > 0.05) after adjusting for influencing factors. Further analysis suggested that each influencing factor has different effects on symptoms and signs, among which menopause affects the SPEED score (R = -4.112, p = 0.025), and age and region have significant effects on eyelid margin abnormalities. CONCLUSIONS: In conclusion, the results demonstrated a poor correlation between symptoms and signs in MGD patients. Age, hormone, and a dry environment may influence the disease, which suggests that the severity of the disease needs to be comprehensively assessed.


Assuntos
Síndromes do Olho Seco , Doenças Palpebrais , Disfunção da Glândula Tarsal , Idoso , Feminino , Humanos , Glândulas Tarsais , Estudos Prospectivos , Lágrimas
19.
Mediators Inflamm ; 2022: 6508046, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36267243

RESUMO

There has been a significant amount of interest in the past two decades in the study of the evolution of the gut microbiota, its internal and external impacts on the gut, and risk factors for cerebrovascular disorders such as cerebral ischemic stroke. The network of bidirectional communication between gut microorganisms and their host is known as the microbiota-gut-brain axis (MGBA). There is mounting evidence that maintaining gut microbiota homeostasis can frequently enhance the effectiveness of ischemic stroke treatment by modulating immune, metabolic, and inflammatory responses through MGBA. To effectively monitor and cure ischemic stroke, restoring a healthy microbial ecology in the gut may be a critical therapeutic focus. This review highlights mechanistic insights on the MGBA in disease pathophysiology. This review summarizes the role of MGBA signaling in the development of stroke risk factors such as aging, hypertension, obesity, diabetes, and atherosclerosis, as well as changes in the microbiota in experimental or clinical populations. In addition, this review also examines dietary changes, the administration of probiotics and prebiotics, and fecal microbiota transplantation as treatment options for ischemic stroke as potential health benefits. It will become more apparent how the MGBA affects human health and disease with continuing advancements in this emerging field of biomedical sciences.


Assuntos
AVC Isquêmico , Probióticos , Acidente Vascular Cerebral , Humanos , Prebióticos , Transplante de Microbiota Fecal , Probióticos/uso terapêutico , Encéfalo/metabolismo , Acidente Vascular Cerebral/terapia , Acidente Vascular Cerebral/metabolismo
20.
Mediators Inflamm ; 2022: 6943438, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36016663

RESUMO

Objective: To study the effects of electroacupuncture at Baihui and Dazhui points on the expression of hepcidin (Hepc), transferrin (Tf), transferrin receptor (TfR), and ferritin (Ft) in rats with cerebral hemorrhage to provide a theoretical basis for the treatment of cerebral hemorrhage with acupuncture. Method: The model of cerebral hemorrhage in rats was established by autologous blood injection method and treated by electroacupuncture (EA) at the acupoints of Baihui and Dazhui. Hepc siRNA was injected into the lateral ventricle 30 min before model preparation to produce the cerebral hemorrhage model. The modified neurological severity score (mNSS) was used to assess the neurological function, and the total iron content in brain tissue was determined using atomic absorption spectrometry; the expression of Hepc, Ft, Tf, and TfR in perihematoma tissue was detected using immunohistochemistry; the interference efficiency of Hepc siRNA was detected using western blot and reverse transcription polymerase chain reaction (RT-PCR). Results: The degree of neurological deficit showed a downward trend at 3 days, 7 days, and 14 days, and electroacupuncture significantly reduced the neurological deficit score at each time point (P < 0.01). Regarding total iron content in brain tissue, on the 3rd day, the 7th day, and the 14th day, the iron content of the hematoma tissue after intracerebral hemorrhage was reduced by electroacupuncture (P < 0.01). Regarding immunohistochemical results. Hepc, Ft, Tf, and TfR protein expressions on day 14 were significantly higher after cerebral hemorrhage (P < 0.01). After electroacupuncture, the expression of Hepc, Ft, Tf, and TfR protein was significantly reduced (P < 0.01). Western blot and RT-PCR revealed that the interference efficiency of Hepc siRNA was statistically significant (P < 0.01). Conclusion: Electroacupuncture can reduce neurological severity scores in rats with cerebral hemorrhage and may exert cerebral protective effects by reducing Hepc protein and gene expression; lowering Ft, Tf, and TfR protein expression; and promoting iron metabolism in the brain of rats with cerebral hemorrhage.


Assuntos
Lesões Encefálicas , Isquemia Encefálica , Eletroacupuntura , Animais , Lesões Encefálicas/metabolismo , Isquemia Encefálica/metabolismo , Hemorragia Cerebral/terapia , Eletroacupuntura/métodos , Ferro , RNA Interferente Pequeno , Ratos , Ratos Sprague-Dawley
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