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1.
Mol Med Rep ; 29(5)2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38551163

RESUMO

Endothelial barrier disruption plays a key role in the pathophysiology of heat stroke (HS). Knockout of DNAJA1 (DNAJA1­KO) is thought to be protective against HS based on a genome­wide CRISPR­Cas9 screen experiment. The present study aimed to illustrate the function of DNAJA1­KO against HS in human umbilical vein endothelial cells. DNAJA1­KO cells were infected using a lentivirus to investigate the role of DNAJA1­KO in HS­induced endothelial barrier disruption. It was shown that DNAJA1­KO could ameliorate decreased cell viability and increased cell injury, according to the results of Cell Counting Kit­8 and lactate dehydrogenase assays. Moreover, HS­induced endothelial cell apoptosis was inhibited by DNAJA1­KO, as indicated by Annexin V­FITC/PI staining and cleaved­caspase­3 expression using flow cytometry and western blotting, respectively. Furthermore, the endothelial barrier function, as measured by transepithelial electrical resistance and FITC­Dextran, was sustained during HS. DNAJA1­KO was not found to have a significant effect on the expression and distribution of cell junction proteins under normal conditions without HS. However, DNAJA1­KO could effectively protect the HS­induced decrease in the expression and distribution of cell junction proteins, including zonula occludens­1, claudin­5, junctional adhesion molecule A and occludin. A total of 4,394 proteins were identified using proteomic analysis, of which 102 differentially expressed proteins (DEPs) were activated in HS­induced wild­type cells and inhibited by DNAJA1­KO. DEPs were investigated by enrichment analysis, which demonstrated significant enrichment in the 'calcium signaling pathway' and associations with vascular­barrier regulation. Furthermore, the 'myosin light­chain kinase (MLCK)­MLC signaling pathway' was proven to be activated by HS and inhibited by DNAJA1­KO, as expected. Moreover, DNAJA1­KO mice and a HS mouse model were established to demonstrate the protective effects on endothelial barrier in vivo. In conclusion, the results of the present study suggested that DNAJA1­KO alleviates HS­induced endothelial barrier disruption by improving thermal tolerance and suppressing the MLCK­MLC signaling pathway.


Assuntos
Proteínas de Choque Térmico HSP40 , Golpe de Calor , Animais , Humanos , Camundongos , Golpe de Calor/genética , Golpe de Calor/metabolismo , Proteínas de Choque Térmico HSP40/genética , Células Endoteliais da Veia Umbilical Humana , Camundongos Knockout , Proteômica , Transdução de Sinais
2.
Zhongguo Gu Shang ; 37(2): 159-65, 2024 Feb 25.
Artigo em Chinês | MEDLINE | ID: mdl-38425067

RESUMO

OBJECTIVE: To observe the residual of lumbago and leg pain with contained type (CT) and non-contained type (NCT) lumbar disc herniation (LDH) after transforaminal endoscopic treatment, and to explore the role of hypoxia-inducible factor-1α(HIF-1α) and transient receptor potential vanillate 1(TRPV1) pathway. METHODS: A total of 68 single-segment LDH patients were selected from July 2021 to October 2022, including 44 males and 24 females;aged 26 to 67 years old with an average of(43.63±11.94) years old;course of disease was 4 to 36 (18.91±10.34) months;body mass index was (24.45±4.00) kg·m-2;there were 7 cases of L3,4 segments, 32 cases of L4,5 segments, and 29 cases of L5S1 segments. All of them were performed with percutaneous intervertebral endoscopic extraction of nucleus pulposus and were divided into contained group(CT group) and non-contained group (NCT group) with 34 cases respectively according to the integrity of outer layer of fibrous annulus observed during operation. A total of 17 patients who underwent open surgery for scoliosis or vertebral fracture were selected as control group, including 12 males and 5 females;aged 21 to 65 years old with an average of (39.41±12.80) years old;body mass index was (24.86±4.11) kg·m-2. The relative mRNA expression quantity of HIF-1α, TRPV1 in nucleus pulposus were measured by quantitative real-time PCR. The contents of neurokinin 1 receptor (NK1R), nerve growth factor (NGF), vascular endothelial growth factor (VEGF) in nucleus pulposus and the serum substance P (SP) and calcitonin gene-related peptide (CGRP) were detected by enzyme linked immunosorbent assay (ELISA). The threshold of lumbar tenderness was detected by a pressure pain meter. The degree of lumbago and lumbar function were evaluated by visual analog scale (VAS) and Oswestry disability index (ODI) separately. The residual rate of postoperative lumbago and leg pain was assessed. RESULTS: The mRNA relative expression quantity of HIF-1α and TRPV1, and the contents of NK1R, NGF and VEGF in nucleus pulposus, and the levels of serum SP and CGRP before surgery in the NCT group were higher than those in the CT group(P<0.05), and those in the CT group were higher than the control group(P<0.05). At day 7 after surgery, the serum SP and CGRP levels, lumbago and leg pain VAS scores and lumbar ODI index in two LDH groups were lower than before surgery (P<0.05), and those in the NCT group were higher than the CT group(P<0.05), and the threshold of lumbar tenderness in the NCT group was lower than the CT group(P<0.05). The differences of lumbago and leg pain VAS scores, lumbar ODI index and lumbar tenderness threshold between preoperative and postoperative 7 days in the NCT group were lower than those in the CT group(P<0.05). The residual rate of lumbago and leg pain at 7 days after surgery in the NCT group was higher than that in the CT group(P<0.05). CONCLUSION: HIF-1α and TRPV1 pathway promoted the excessive production of NGF, VEGF, NK1R in nucleus pulposus and serum neuropeptides SP and CGRP, which may lead to the higher residual rate of lumbago and leg pain with non-contained lumbar disc herniation postoperative.


Assuntos
Discotomia Percutânea , Deslocamento do Disco Intervertebral , Dor Lombar , Masculino , Feminino , Humanos , Adulto , Pessoa de Meia-Idade , Idoso , Adulto Jovem , Deslocamento do Disco Intervertebral/cirurgia , Fator A de Crescimento do Endotélio Vascular , Perna (Membro)/cirurgia , Peptídeo Relacionado com Gene de Calcitonina , Fator de Crescimento Neural , Resultado do Tratamento , Vértebras Lombares/cirurgia , Estudos Retrospectivos , Endoscopia , RNA Mensageiro
3.
Plants (Basel) ; 13(3)2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38337959

RESUMO

Tea is a popular beverage with characteristic functional and flavor qualities, known to be rich in bioactive metabolites such as tea polyphenols and theanine. Recently, tea varieties with variations in leaf color have been widely used in agriculture production due to their potential advantages in terms of tea quality. Numerous studies have used genome, transcriptome, metabolome, proteome, and lipidome methods to uncover the causes of leaf color variations and investigate their impacts on the accumulation of crucial bioactive metabolites in tea plants. Through a comprehensive review of various omics investigations, we note that decreased expression levels of critical genes in the biosynthesis of chlorophyll and carotenoids, activated chlorophyll degradation, and an impaired photosynthetic chain function are related to the chlorina phenotype in tea plants. For purple-leaf tea, increased expression levels of late biosynthetic genes in the flavonoid synthesis pathway and anthocyanin transport genes are the major and common causes of purple coloration. We have also summarized the influence of leaf color variation on amino acid, polyphenol, and lipid contents and put forward possible causes of these metabolic changes. Finally, this review further proposes the research demands in this field in the future.

4.
World J Gastrointest Surg ; 15(9): 1941-1949, 2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37901734

RESUMO

BACKGROUND: Mortality rates after pancreaticoduodenectomy (PD) have significantly decreased in specialized centers. However, postoperative morbidity, particularly delayed gastric emptying (DGE), remains the most frequent complication following PD. AIM: To identify risk factors associated with DGE after the PD procedure. METHODS: In this retrospective, cross-sectional study, clinical data were collected from 114 patients who underwent PD between January 2015 and June 2018. Demographic factors, pre- and perioperative characteristics, and surgical complications were assessed. Univariate and multivariate analyses were performed to identify risk factors for post-PD DGE. RESULTS: The study included 66 males (57.9%) and 48 females (42.1%), aged 33-83 years (mean: 62.5), with a male-to-female ratio of approximately 1.4:1. There were 63 cases (55.3%) of PD and 51 cases (44.7%) of pylorus-preserving pancreatoduodenectomy. Among the 114 patients who underwent PD, 33 (28.9%) developed postoperative DGE. Univariate analysis revealed significant differences in four of the 14 clinical indexes observed: pylorus preservation, retrocolonic anastomosis, postoperative abdominal complications, and early postoperative albumin (ALB). Logistic regression analysis further identified postoperative abdominal complications [odds ratio (OR) = 4.768, P = 0.002], preoperative systemic diseases (OR = 2.516, P = 0.049), and early postoperative ALB (OR = 1.195, P = 0.003) as significant risk factors. CONCLUSION: Postoperative severe abdominal complications, preoperative systemic diseases, and early postoperative ALB are identified as risk factors for post-PD DGE.

5.
Ecotoxicol Environ Saf ; 252: 114623, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36774793

RESUMO

Multi-walled carbon nanotubes (MWCNTs) mainly induce oxidative stress through the overproduction of reactive oxygen species (ROS), which can lead to cytotoxicity. Celastrol, a plant-derived compound, can exert antioxidant effects by reducing ROS production. Our results indicated that exposure to MWCNTs decreased cell viability and increased ROS production. Nrf2 knockdown (kd) led to increased ROS production and enhanced MWCNT-induced cytotoxicity. Keap1-kd led to decreased ROS production and attenuated cytotoxicity. Treatment with celastrol significantly decreased ROS production and promoted Keap1 protein degradation through the lysosomal pathway, thereby enhancing the translocation of Nrf2 from the cytoplasm to the nucleus and increasing HO-1 expression. The in vivo results showed that celastrol could alleviate the inflammatory damage of lung tissues, increase the levels of the antioxidants, GSH and SOD, as well as promote the expression of the antioxidant protein, HO-1 in MWCNT-treated mice. Celastrol can alleviate MWCNT-induced oxidative stress through the Keap1/Nrf2/HO-1 signaling pathway.


Assuntos
Nanotubos de Carbono , Camundongos , Animais , Espécies Reativas de Oxigênio/metabolismo , Nanotubos de Carbono/toxicidade , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Estresse Oxidativo , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Transdução de Sinais
6.
Soft Matter ; 18(45): 8656-8662, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36349695

RESUMO

Amphiphilic molecules can self-assemble in solution into a variety of supramolecular assemblies, ranging from simple micelles, ribbons, and tubes to complex cubosomes with bicontinuous cubic nanostructures. It is well known that the self-assembly of chiral building blocks into one-dimensional (1D) twisted fibers, helical ribbons, and tubes enables chiral transfer from the molecular scale to super-assemblies. In this study, we investigate the chirality of three-dimensional (3D) supramolecular assemblies, such as colloidal onions, cubosomes, and hexosomes, formed from the same chiral heteroclusters. Unlike supramolecular 1D helical ribbons, these assemblies do not have chiral external shapes or chiral internal nanostructures, but they do exhibit circular dichroism, suggesting that they are chiral. Structural studies revealed that the ordered arrangement of the chiral units in curved superstructures is the origin of the supramolecular chirality of these 3D assemblies. Therefore, this study provides insights for enriching the diversity and complexity of supramolecular chiral assemblies.


Assuntos
Nanoestruturas , Cebolas , Estereoisomerismo , Dicroísmo Circular , Nanoestruturas/química , Micelas
7.
Nanotoxicology ; 16(5): 597-609, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-36151876

RESUMO

Multiwalled carbon nanotubes (MWCNTs) are currently widely used and are expected to be used as drug carriers and contrast agents in clinical practice. Previous studies mainly focused on their lung toxicity; therefore, their effects on the vascular endothelium are unclear. In this study, a human angiogenesis array was used to determine the effect of MWCNTs on the expression profile of angiogenic factors in endothelial cells and to clarify the role of vascular endothelial growth factor (VEGF) in MWCNT-induced endothelial cell injury at the cellular and animal levels. The results indicated that MWCNTs (20-30 nm and 30-50 nm) could enter endothelial cells and disrupt human umbilical vein endothelial cell (HUVECs) activity in a concentration-dependent manner. MWCNTs disrupted the tube formation ability and cell migration function of HUVECs. The results from a Matrigel Plug experiment in mice showed that angiogenesis in the MWCNT experimental group was significantly reduced. The results of a protein chip analysis indicated that VEGF expression in the MWCNT treatment group was decreased, a finding that was validated by ELISA results. The protein expression levels of AKT and eNOS in the MWCNT treatment group were significantly decreased; the administration of recombinant VEGF significantly alleviated the migration ability and tube formation ability of endothelial cells injured by MWCNTs, upregulated the protein expression of AKT and eNOS, and increased the number of neovascularization in mice in the MWCNT treatment group. This study demonstrated that MWCNTs affect angiogenesis via the VEGF-Akt-eNOS axis which can be rescued by VEGF endothelial treatment.


Assuntos
Nanotubos de Carbono , Fator A de Crescimento do Endotélio Vascular , Humanos , Camundongos , Animais , Nanotubos de Carbono/toxicidade , Proteínas Proto-Oncogênicas c-akt , Células Endoteliais da Veia Umbilical Humana , Movimento Celular
8.
Front Pharmacol ; 12: 765790, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34733164

RESUMO

Psoriasis is characterized by keratinocyte proliferation and immune cell infiltration. M2 isoform of pyruvate kinase (PKM2) was reported to have an important role in cell proliferation, which is a rate-limiting enzyme that regulates the final step of glycolysis. However, how PKM2 regulates cell metabolism and proliferation in psoriatic keratinocytes is still poorly understood. Interestingly, we found that PKM2 was highly expressed in psoriatic epidermis from patients and mouse models. PKM2 overexpression promoted keratinocyte glycolytic metabolism while knockdown inhibited keratinocyte proliferation and glycolysis. Mice lacking PKM2 specifically in keratinocytes, pharmacological inhibition of PKM2 or glycolysis inhibited keratinocyte proliferation and showed obvious remission in an imiquimod-induced psoriatic mouse model. Moreover, the inhibitor of the EGF-receptor blocked EGF-stimulated PKM2 expression and glycolysis in keratinocytes. We identify PKM2 as an upregulated gene in psoriasis. PKM2 is essential in keratinocyte over-proliferation and may represent a therapeutic target for psoriasis.

9.
Langmuir ; 37(34): 10291-10297, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34410133

RESUMO

Heteroclusters constructed by tethering dissimilar nanoclusters using organic linkers resemble lipids and self-assemble into cubosomes, namely, microparticles of soft crystals composed of unique nanochannel lattices with a defined symmetry and topology. The internal porous crystal structures can be accurately characterized using transmission electron microscopy. We herein describe twin boundaries and five-fold twin boundaries in cubosomes with a double-diamond Pn3̅m structure. Our analysis indicates a clear distinction in the conformation of the skeletal unit: a centrosymmetric staggered conformation with point group D3d for the normal skeletal unit and a mirror-symmetric eclipsed one with point group D3h for the skeletal unit on the twin boundary. This symmetry distinction causes the channels to change direction and elongate slightly as they pass through the twin boundary, but the topology is maintained. For cubosomes containing five-fold twin boundaries, one of the channels is in the center of the particles seamlessly connecting the five blocks. Our conclusion is that the two distinct channel systems are still continuous. This fundamental understanding will contribute to the development of soft crystals with defined shapes and special inner nanostructures for advanced applications.

10.
Medicine (Baltimore) ; 100(3): e23699, 2021 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-33545937

RESUMO

BACKGROUND: Gouty arthritis (GA) is a chronic disease caused by monosodium urate crystal deposition. Repeated attacks of arthritis may lead to the deposition of urate to form gout stone, resulting in joint deformity and joint damage. Although GA is not fatal, it causes low work productivity and low quality of life. Western drug, such as febuxostat, colchicine, allopurinol, often cannot get satisfying curative effect, and may even lead to serious side effects, such as exfoliative dermatitis or uremia. However, the therapeutic effect of Traditional Chinese medicine is very satisfactory. The treatment effect of simiao powder, a Chinese patent medicine, combined with acupuncture was widely used on treatment of GA. Although it has been widely used in clinical practice, its relative effectiveness and safety have not been confirmed. Therefore, this study will use meta-analysis to verify the efficacy and safety of simiao powder combined with acupuncture in the treatment of GA. METHODS: All randomized controlled trial of simiao powder combined with acupuncture for the treatment of RA from their inception 29 October, 2020 will be searched form the China National Knowledge Infrastructure, Wanfang Database, Chinese Science and Technology Periodical Database, Chinese Biomedical Literature Database, Pubmed, Embase, Web of Science, and the Cochrane library. Two authors will independently select studies, extract data based on pre-designed inclusion and exclusion criteria. Methodological quality assessment and risk of bias will be assessed using Cochrane bias risk tool. All data analysis will be conducted using Revman5.3, WinBUGS 1.4.3, and Stata14.2 software. RESULTS: We will compare the different outcome indicators of various studies to provide a synthesis of the efficacy and safety of Simiao powder combined with acupuncture for GA patients. The main outcome measures included efficacy, remission rate (no drug symptoms), recurrence rate, clinical absolute score and relative score. Secondary outcome measures included related adverse reactions and uric acid concentration. CONCLUSION: The findings of the study will provide helpful evidence for the efficacy and safety of simiao powder combined with acupuncture in the treatment of GA. REGISTRATION NUMBER: This study protocol have been funded through a protocol registry. The registry number is INPLASY2020110028.


Assuntos
Acupuntura , Artrite Gotosa , Medicamentos de Ervas Chinesas , Humanos , Artrite Gotosa/terapia , Terapia Combinada , Medicamentos de Ervas Chinesas/administração & dosagem , Medicamentos de Ervas Chinesas/uso terapêutico , Metanálise como Assunto , Resultado do Tratamento
11.
Adv Mater ; 32(3): e1805863, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31216098

RESUMO

Cluster materials have attracted much attention because of their unique chemical and physical properties, hitherto unseen in bulk materials. Inspired by the lipid self-assembly principle, a series of heterocluster Janus molecules (HCJMs) with atomic precision have been rationally designed and synthesized by connecting different clusters via covalent bonds for the construction of nanomaterials and nano-objects. Due to their amphiphilicity, HCJMs self-assemble into cluster-containing nanomaterials or nano-objects with versatile ordered structures beyond those observed in conventional crystals. Their hybrid composition and nanoscale size are also greatly advantageous in the study of their fine structure by electron microscopy techniques, and enable their formation mechanisms to be unraveled. Finally, the influence of the characteristics of the HCJMs on the structure and properties of the self-assembled nano-objects are explored comprehensively. This synthesis strategy will promote further development of cluster materials with advanced functions via rational molecular design toward the construction of hierarchical nanostructures via molecular self-assembly.

12.
Chemistry ; 25(58): 13396-13401, 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31397509

RESUMO

Organic polymers and inorganic clusters belong to two different disciplines and have completely different properties and structures. When a cluster is attached to the backbone of a polymer as a pendant, the resultant hybrid polymers (polyclusters) exhibit unique behaviours totally different from those of conventional polymers owing to the nanoscale size of the cluster and its particular interactions. Herein, the aggregation of a poly(polyoxometalate)-a polynorbornene backbone with inorganic polyoxometalate cluster pendants-upon addition of a non-solvent to its dilute solution is reported. A three-dimensional network of tangled and snake-like nanothreads was observed. Direct visualisation of individual nanoscale clusters enabled identification of single chains within the nanothreads. These observations suggest that during the process of aggregation, the hybrid polymer forms curved or extended chains as a consequence of an armouring effect in which the collapsed cluster pendants wrap around the backbone. The collapse occurs because they become less soluble in the solvent/non-solvent mixture. The extended chains then become entwined and form nanoropes consisting of multiple chains wound around each other. This study provides a deeper understanding of the nature of polyclusters and should also prove useful for their future development and application.

13.
Langmuir ; 35(20): 6727-6734, 2019 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-31030522

RESUMO

Diverse nanostructures and nano-objects for advanced applications are created by the self-assembly of lipids, surfactants, and block copolymers. Understanding this process is critical for improving their functions and expanding their applications. Accordingly, we pioneered the synthesis and application of heterocluster Janus molecules (HCJMs), which resemble conventional amphiphiles. Their self-assembly into nanostructures and nano-objects can be directly characterized by transmission electron microscopy (TEM), allowing the process to be unraveled through the monitoring of the intermediates. In this study, we focused on the TEM characterization of HCJM-based colloidal onions, which have an onion-like inner structure, to gain insight into the self-assembly process from molecules to perfect onions. Multiple mechanisms, including molecular aggregation, structural ordering within aggregates into colloidal onions, and layer-by-layer growth caused by particle coarsening, contributed to the overall self-assembly process. The analysis also indicated that the reduction in the Gibbs free energy and bending free energy of curved layers are the driving forces for structural ordering and onion growth. Finally, this work provided a useful method for preparing colloidal onions for attractive applications in nanomedicine and other areas.

14.
J Cell Mol Med ; 23(5): 3665-3675, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30892812

RESUMO

This study aimed to investigate the role of apoptotic bodies (Abs) from the oxidative stressed endplate chondrocytes in regulating mineralization and potential mechanisms. Endplate chondrocytes were isolated from rats and treated with H2O2 to induce oxidative stress. The calcium deposition for matrix mineralization in the cells was examined by histological staining. The expression levels of calcification-related genes in individual groups of cells were determined by quantitative real time-PCR (qRT-PCR). Subsequently, extracellular vesicles (EVs) were purified and characterized. The effect of treatment with H2O2 and/or Abs on the mineralization, extracellular PPi metabolism and related gene expression were determined. Oxidative stress significantly increased the mineralization and promoted the generation of main Abs from endplate chondrocytes. Abs were effectively endocytosed by endplate chondrocytes and co-localized with collagen (COL)-II in the cytoplasm, which enhanced the mineralization, alkaline phosphatase (ALP), osteocalcin (OCN), Runt-related transcription factor 2 (RUNX2) and COL-I expression in endplate chondrocytes. Furthermore, treatment either H2O2 or Abs significantly decreased PPi, but increased Pi production and treatment with both further enhancing the changes in endplate chondrocytes. Similarly, treatment either H2O2 or Abs significantly decreased the ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1), and ankylosis protein (ANK) expression and ENPP1 promoter activity, but increased the tissue-nonspecific alkaline phosphatase (TNAP) expression and TNAP promoter activity in endplate chondrocytes. Oxidative stress promoted the generation of Abs, which might enhance the oxidative stress-mediated mineralization in endplate chondrocytes by regulating the PPi metabolism.


Assuntos
Calcinose/metabolismo , Condrócitos/metabolismo , Vesículas Extracelulares/metabolismo , Estresse Oxidativo , Diester Fosfórico Hidrolases/metabolismo , Pirofosfatases/metabolismo , Fosfatase Alcalina/genética , Fosfatase Alcalina/metabolismo , Animais , Calcinose/genética , Células Cultivadas , Condrócitos/efeitos dos fármacos , Colágeno/genética , Colágeno/metabolismo , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Vesículas Extracelulares/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Lâmina de Crescimento/citologia , Peróxido de Hidrogênio/farmacologia , Oxidantes/farmacologia , Diester Fosfórico Hidrolases/genética , Pirofosfatases/genética , Ratos
15.
J Am Chem Soc ; 141(2): 831-839, 2019 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-30501178

RESUMO

Cubosomes are bicontinuous cubic-phase particles generated by amphiphile self-assembly with bicontinuous cubic phases, which creates an intricate network of interconnected nanochannels that endow these materials with special functions for advanced applications. On the other hand, clusters are an attractive class of molecules that exhibit intriguing functions and properties that differ from those of atoms and nanoparticles. Inspired by lipid self-assembly and attracted to the new functionalities of clusters, we prepared special heterocluster Janus dumbbells (HCJDs) composed of dissimilar nanoclusters: namely, a polyoxometalate and a polyhedral oligomeric silsesquioxane. HCJDs resemble conventional amphiphiles and, as such, they self-assemble in solution into faceted hybrid cubosomes via the transformation of vesicles into spongelike aggregates. Multiple mechanisms that lead to equilibrium, including molecular self-assembly, vesicle accumulation, membrane fusion, inner-structure reorganization, and cubic crystal growth, contributed to the overall process. On the basis of these results, we proposed a strategy for self-assembly-from basic molecular design that goes beyond traditional amphiphiles to the construction of micro- or nanomaterials with hierarchical structures and advanced functions.


Assuntos
Nanoestruturas/química , Compostos de Organossilício/química , Compostos de Tungstênio/química , Estrutura Molecular , Compostos de Organossilício/síntese química , Compostos de Tungstênio/síntese química
16.
Chem Asian J ; 13(7): 775-779, 2018 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-29392923

RESUMO

Soft nanotubes are normally constructed from chiral amphiphiles through helical self-assembly. Yet, how to self-assemble achiral molecules into nanotubes is still a challenge. Here, we report the nanotube construction with achiral shape amphiphiles through helical self-assembly and also unravel the formation mechanisms. The amphiphiles have a dumbbell shape and are composed by covalently linking three achiral moieties together: two unlike clusters and an organic tether. The difference in polarity between the unlike clusters drives the amphiphiles to self-assemble into single- and multi-walled nanotubes as well as intermediates. Analysis of the key intermediates unravels the self-assembly mechanism of helicity-selective nucleation and growth. Meanwhile, direct visualization of the individual clusters in the ribbons displays a two-dimensional deformed hexagonal lattice. Thus, we speculate that it is the lattice deformation that creates anisotropic tension along different directions of the ribbon which further results in the formation of helical ribbons towards nanotubes by amphiphiles.

17.
J Am Chem Soc ; 140(5): 1805-1811, 2018 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-29156881

RESUMO

Honeycomb structure endows graphene with extraordinary properties. But could a honeycomb monolayer superlattice also be generated via self-assembly of colloids or nanoparticles? Here we report the construction of mono- and multilayer molecular films with honeycomb structure that can be regarded as self-assembled artificial graphene (SAAG). We construct fan-shaped molecular building blocks by covalently connecting two kinds of clusters, one polyoxometalate and four polyhedral oligomeric silsesquioxanes. The precise shape control enables these complex molecules to self-assemble into a monolayer 2D honeycomb superlattice that mirrors that of graphene but on the mesoscale. The self-assembly of the SAAG was also reproduced via coarse-grained molecular simulations of a fan-shaped building block. It revealed a hierarchical process and the key role of intermediate states in determining the honeycomb structure. Experimental images also show a diversity of bi- and trilayer stacking modes. The successful creation of SAAG and its stacks opens up prospects for the preparation of novel self-assembled nanomaterials with unique properties.

18.
Langmuir ; 33(21): 5283-5290, 2017 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-28485939

RESUMO

Clusters are an important class of nanoscale molecules or superatoms that exhibit an amazing diversity in structure, chemical composition, shape, and functionality. Assembling two types of clusters is creating emerging cluster-assembled materials (CAMs). In this paper, we report an effective approach to produce quasi two-dimensional (2D) CAMs of two types of spherelike clusters, polyhedral oligomeric silsesquioxanes (POSS), and polyoxometalates (POM). To avoid macrophase separation between the two clusters, they are covalently linked to form a POM-POSS cocluster with Janus characteristics and a dumbbell shape. This Janus characteristics enables the cocluster to self-assemble into diverse nanoaggregates, as conventional amphiphilic molecules and macromolecules do, in selective solvents. In our study, we obtained micelles, vesicles, nanosheets, and nanoribbons by tuning the n-hexane content in mixed solvents of acetone and n-hexane. Ordered packing of clusters in the nanosheets and nanoribbons were directly visualized using high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) technique. We infer that the increase of packing order results in the vesicle-to-sheet transition and the change in packing mode causes the sheet-to-ribbon transitions. Our findings have verified the effectivity of creating quasi 2D cluster-assembled materials though the cocluster self-assembly as a new approach to produce novel CAMs.

19.
Asia Pac J Clin Nutr ; 25(4): 911-919, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27702735

RESUMO

BACKGROUND AND OBJECTIVES: The aim of this study was to explore the influence of fluoride exposure and ERα gene polymorphisms on reproductive hormone concentrations of women in accordance with endemic fluorosis residence. METHODS AND STUDY DESIGN: A cross sectional study was conducted in Tongxu county, Henan Province, China. A total of 679 women were recruited using cluster sampling and each subject provided fasting blood and an associated urine sample. We measured the concentrations of serum gonadotropin releasing hormone (GnRH), follicle-stimulating hormone, luteinizing hormone, and estradiol and urinary fluoride. RESULTS: In the defluoridation project group (DFPG), serum GnRH was lower in women carrying C/C genotype compared to in those carrying C/T and T/T genotypes of ERα gene rs3798577 (p<0.05). In the endemic fluorosis group (EFG), serum GnRH was lower in women carrying Pp genotype compared to in those carrying PP and pp genotypes of ERα PvuII (p<0.05). Serum GnRH in women from EFG who carried Pp, pp, Xx and xx genotypes in ERα gene PvuII and XbaI was lower than in those in the control group (CG) who carried same genotypes (p<0.05). Furthermore, serum GnRH in women from EFG was significantly lower than in those in CG, regardless of whether the women were carrying C/C, C/T or T/T genotypes of ERα rs3798577 (p<0.05). Serum estradiol concentrations in EFG were significantly lower than in CG when the women were carrying the Pp, Xx and T/T genotypes in ERα gene (p<0.05). CONCLUSION: Interaction of ERα gene and fluoride exposure may influence women's serum reproductive hormone concentrations.


Assuntos
Doenças Endêmicas , Receptor alfa de Estrogênio/genética , Intoxicação por Flúor/epidemiologia , Intoxicação por Flúor/genética , Fluoretos/efeitos adversos , Hormônios/sangue , Adolescente , Adulto , China/epidemiologia , Estudos Transversais , Exposição Ambiental , Estradiol/sangue , Feminino , Fluoretos/urina , Fluorose Dentária , Hormônio Foliculoestimulante/sangue , Genótipo , Hormônio Liberador de Gonadotropina/sangue , Humanos , Hormônio Luteinizante , Pessoa de Meia-Idade , Polimorfismo Genético , Adulto Jovem
20.
Langmuir ; 32(2): 460-7, 2016 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-26710830

RESUMO

In this work, we report the preparation of complex nano-objects by means of a stepwise self-assembly of two polymer-polyoxometalate hybrids (PPHs) in solution. The PPHs are designed and synthesized by tethering two linear poly(ε-caprolactone)s (PCL) of different molecular weights (MW) on a complex of a Wells-Dawson-type polyoxometalate (POM) cluster and its countraions. The higher MW PCL-POM self-assembled into nanosheets, while the lower MW PCL-POM assembled into nanotubes just by altering the ratio of water in the DMF-water mixed solvent system. The two nano-objects have a similar membrane structure in which a PCL layer is sandwiched by the two POM-based complex layers. The PCL layer in the nanosheets is semicrystalline, while the PCL layer in the nanotubes is amorphous. We further exploited this MW-dependence to self-assemble the nanotubes on the nanosheet edges to create complex tube-graft-sheet nano-objects. We found that the nanotubes nucleate on the four {110} faces of the PCL crystal and then further grow along the crystallographic b-axis of the PCL crystal. Our findings offer hope for the further development of nano-objects with increasing complexity.

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