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1.
Biomed Res Int ; 2021: 6380141, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33708990

RESUMO

The aim of this study was to investigate the therapeutic efficacy and safety of transplanting human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) in the treatment of cartilage injury. First, the articular cartilage defect model in rabbits was constructed. Then, the identified hUCB-MSCs and rabbit bone marrow stem cells (rBM-MSCs) were transplanted into the bone defect, respectively, and the cartilage repair effect was observed by hematoxylin-eosin (HE) staining and immunohistochemistry. Besides, the glycosaminoglycan (GAG) content and biomechanics of the restoration area were also evaluated. In our study, hUCB-MSCs and rBM-MSCs exhibited typical MSC characteristics, with positive expressions of CD73, CD105, and CD90 and negative for CD45, CD34, CD14, and HLA-DR. After the transplantation of hUCB-MSCs and rBM-MSCs, the overall quality of cartilage tissue was significantly improved, and the recipients did not show significant side effects in general. However, the expression of matrix metalloproteinase-13 (MMP-13) in the de novo tissues of the hUCB-MSCs and rBM-MSCs groups was both increased, indicating that the novel tissues may have some potential osteoarthritic changes. In conclusion, our results suggest the therapeutic effect of hUCB-MSCs transplantation in cartilage regeneration, providing a promising future in the clinical treatment of cartilage injury.

2.
Diabetes ; 2021 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-33574020

RESUMO

Recent evidence suggests that melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs), a neuronal class regulating non-image forming (NIF) vision and generally thought to be injury-resistant, are dysfunctional in certain neurodegenerative diseases. Although disrupted NIF visual functions have been reported in patients and animals with diabetes, it remains controversial whether ipRGCs exhibit remodeling during diabetes and if so, whether such remodeling is variable among ipRGC subtypes. Here we demonstrate that survival, soma-dendritic profiles and melanopsin-based functional activity of M1 ipRGCs were unaltered in streptozotocin-induced 3-month diabetic mice. Such resistance remained at 6 months after streptozotocin administration. In contrast, M2/M3 ipRGCs underwent significant remodeling in diabetic mice, manifested by enlarged somata and increased dendritic branching complexity. Consistent with the unaltered melanopsin levels, the sensitivity of melanopsin-based activity was unchanged in surviving M2 cells, but their response gain displayed a compensatory enhancement. Meanwhile, the pupillary light reflex, a NIF visual function controlled by M2 cells, was found to be impaired in diabetic animals. The resistance of M1 cells might be attributed to the adjacency of their dendrites to capillaries, which makes them less disturbed by the impaired retinal blood supply at the early stage of diabetes.

3.
Carbohydr Polym ; 258: 117663, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33593547

RESUMO

Most of traditional injectable hydrogels based on light curing or enzyme crosslinking are difficult to control the crosslinking time accurately and lack tissue adhesion, which leads to difficult clinical application and poor tissue repair effect. In this study, a novel injectable DMEM (Dulbecco's Modified Eagle's Medium)-induced phenylboronic acid-modified hyaluronic acid self-crosslinking hydrogel was designed and prepared by combining the phenylboronic acid and a diol on hyaluronic acid as the main network, in which dynamically reversible phenylboronic acid esters imparted good self-healing properties and tissue adhesion properties to the hydrogels. Cell medium that induced the formation of the hydrogel could simulate the pH of the physiological environment and provide uniform nutrients for the encapsulated cells. In addition, in vitro cell experiments indicated that the DMEM-induced phenylboronic acid-modified hyaluronic acid self-crosslinking hydrogel was capable of supporting cell loading and proliferation, thus being a promising candidate for tissue repair materials.

4.
J Neurosci ; 41(12): 2566-2580, 2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33536197

RESUMO

We show for the first time that the neuropeptide orexin modulates pupillary light response, a non-image-forming visual function, in mice of either sex. Intravitreal injection of the orexin receptor (OXR) antagonist TCS1102 and orexin-A reduced and enhanced pupillary constriction in response to light, respectively. Orexin-A activated OX1Rs on M2-type intrinsically photosensitive retinal ganglion cells (M2 cells), and caused membrane depolarization of these cells by modulating inward rectifier potassium channels and nonselective cation channels, thus resulting in an increase in intrinsic excitability. The increased intrinsic excitability could account for the orexin-A-evoked increase in spontaneous discharges and light-induced spiking rates of M2 cells, leading to an intensification of pupillary constriction. Orexin-A did not alter the light response of M1 cells, which could be because of no or weak expression of OX1Rs on them, as revealed by RNAscope in situ hybridization. In sum, orexin-A is likely to decrease the pupil size of mice by influencing M2 cells, thereby improving visual performance in awake mice via enhancing the focal depth of the eye's refractive system.SIGNIFICANCE STATEMENT This study reveals the role of the neuropeptide orexin in mouse pupillary light response, a non-image-forming visual function. Intravitreal orexin-A administration intensifies light-induced pupillary constriction via increasing the excitability of M2 intrinsically photosensitive retinal ganglion cells by activating the orexin receptor subtype OX1R. Modulation of inward rectifier potassium channels and nonselective cation channels were both involved in the ionic mechanisms underlying such intensification. Orexin could improve visual performance in awake mice by reducing the pupil size and thereby enhancing the focal depth of the eye's refractive system.

5.
Environ Microbiol ; 23(2): 1256-1274, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33393158

RESUMO

Laccases are widely present in bacteria, fungi, plants and invertebrates and involved in a variety of physiological functions. Here, we report that Beauveria bassiana, an economic important entomopathogenic fungus, secretes a laccase 2 (BbLac2) during infection that detoxifies insect immune response-generated reactive oxygen species (ROS) and interferes with host immune phenoloxidase (PO) activation. BbLac2 is expressed in fungal cells during proliferation in the insect haemocoel and can be found to distribute on the surface of haemolymph-derived in vivo fungal hyphal bodies or be secreted. Targeted gene-knockout of BbLac2 increased fungal sensitivity to oxidative stress, decreased virulence to insect, and increased host PO activity. Strains overexpressing BbLac2 showed increased virulence, with reduced host PO activity and lowered ROS levels in infected insects. In vitro assays revealed that BbLac2 could eliminate ROS and oxidize PO substrates (phenols), verifying the enzymatic functioning of the protein in detoxification of cytotoxic ROS and interference with the PO cascade. Moreover, BbLac2 acted as a cell surface protein that masked pathogen associated molecular patterns (PAMPs), enabling the pathogen to evade immune recognition. Our data suggest a multifunctional role for fungal pathogen-secreted laccase 2 in evasion of insect immune defenses.

6.
BMC Cancer ; 20(1): 1208, 2020 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-33287756

RESUMO

BACKGROUND: To investigate the clinicopathological characteristics of head and neck small cell carcinoma (H&NSmCC) and identify prognostic factors on the basis of the Surveillance, Epidemiology and End Results (SEER) database. METHODS: Total of 789 primary cases from 1973 to 2016 were included. Univariate and multivariate analyses were performed to identify independent prognostic indicators. An H&NSmCC-specific nomogram was constructed and compared with the AJCC staging system by calculating the time-dependent area under the curve (AUC) of the receiver operating characteristic (ROC) curves. RESULTS: The incidence of H&NSmCC peaked during the period of 50 to 70 years old, and the most frequent location was the salivary gland. The 5-year disease specific survival (DSS) was 27%. In the multivariate survival analysis, AJCC III + IV stage [HR = 2.5, P = 0.03, I + II stage as Ref], positive N stage [HR = 1.67, P = 0.05, negative N stage as Ref], positive M stage [HR = 4.12, P = 0.000, negative M stage as Ref] and without chemotherapy [HR = 0.56, P = 0.023, received chemotherapy as Ref] were independently associated with DSS. The H&NSmCC-specific nomogram was built based on the independent prognostic indicators. The nomogram demonstrated better predictive capacity than the AJCC staging system for 5-year DSS [(AUC: 0.75 vs 0.634; Harrell's C-index (95% CI): 0.7(0.66-0.74) vs 0.59(0.55-0.62), P < 0.05]. CONCLUSION: N stage, M stage, AJCC stage and chemotherapy were independent prognostic indicators included in the prognostic nomogram model, which can better predict the survival of H&NSmCC than the AJCC staging system.

7.
ACS Biomater Sci Eng ; 6(12): 6896-6905, 2020 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-33320592

RESUMO

In recent years, biomimetic tubular scaffolds have been widely used to repair various human tissue defects, due to their hollow structure similar to the native tissues such as blood vessel, trachea, ureter, and bone marrow cavity. However, there are still many challenges in manufacturing a tubular hydrogel scaffold with suitable mechanical properties, specific microstructure, and good biocompatibility. In this study, we exploited an enzymatic cross-linking method using horseradish peroxidase (HRP) as an enzyme and hydrogen peroxide (H2O2) as a substrate, and combining with gelatin's thermal sensitivity to produce an enzymatically cross-linked silk fibroin/gelatin-tyramine (E-SF/GT) tubular hydrogel. Through further treatment with methanol, we fabricated an EM-SF/GT tubular hydrogel with fine-wall architecture that consists of two different layers (inner and outer, dense and porous). Mechanical measurement showed that the compressive moduli values were up to 4.82 MPa and the tensile moduli values were up to 4.79 kPa under the static loading conditions. Also, degradation test showed that the hydrogel's degradation time was prolonged. Finally, the bioactivity was tested by seeding mouse bone marrow mesenchymal stem cells (mBMSCs) in the lumen of a small-diameter (2 mm) EM-SF/GT tubular hydrogel. Cell morphology and immunofluorescence test indicated that mBMSCs differentiated into endothelial cells and lined the inner surface of the tubular hydrogel under induction. This work provided a feasible strategy for developing tubular hydrogels, which could be potentially used as scaffolds for hollow multilayer tissue engineering, such as blood vessels.

8.
J Mater Chem B ; 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-33237117

RESUMO

Tough hydrogels with the ability to be repeatedly processed into various shapes as thermoplastics are highly desired in advanced medical devices and tissue engineering. Here, we have developed a kind of versatile supramolecular hydrogel with a network cross-linked by double hydrogen bonds from poly(N-acryloyl glycinamide) (PNAGA). The resulting PNAGA-30 hydrogels (30 wt% solid content) are tough, re-processable, and recyclable similar to thermoplastics. The hydrogels in the form of fragments can be easily re-processed into various shapes including sheet, filament, cylinder and other complex shapes by using simple stamping and injection methods. The mechanical properties of the re-programed hydrogels are comparable to the properties of the original hydrogels. The re-processability and robust mechanical properties of the PNAGA hydrogels are promising for practical applications in soft materials, tissue engineering and wearable devices. Furthermore, the PNAGA-30&LiCl ionic hydrogels can be fabricated by simply compositing LiCl into thermoplastic hydrogels. The PNAGA-30&LiCl hydrogels can function as multifunctional strain sensors to monitor large human movements and tiny vibrations, thereby showing great application potential in robotics, biomedical prosthetics, personal healthcare monitoring and so on.

9.
BMC Cancer ; 20(1): 967, 2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33023507

RESUMO

BACKGROUND: Malignant tumours of the temporomandibular joint (MTTMJ) are extremely rare. Studies describing its unique epidemiology, clinicopathological features, treatment and prognosis comprehensively are limited. To address these issues, current investigation was performed. METHODS: A retrospective research was carried out by using population-based data from the Surveillance, Epidemiology, and End Results database (1973-2016). RESULTS: Data for a total of 734 patients, including 376 men and 358 women, was found. The median age was 47 years. The 5-year and 10-year disease specific survival (DSS) rates were 69.2 and 63.6%, respectively. Significant differences in DSS were found according to age, race, tumour type, AJCC/TNM stage, surgery, radiotherapy, chemotherapy and different treatment modalities (P < 0.05). In the multivariate survival analysis, age > 44 years and AJCC stage III and IV were associated with poor DSS. CONCLUSION: MTTMJ was mostly found in white people with a median age of 47 years without any sex predominance. Patient's age and AJCC stage was independent predictor of DSS.

10.
Orphanet J Rare Dis ; 15(1): 250, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32933559

RESUMO

BACKGROUND: We previously reported a novel clinically distinguishable subtype of congenital scoliosis (CS), namely, TBX6-associated congenital scoliosis (TACS). We further developed the TBX6-associated CS risk score (TACScore), a multivariate phenotype-based model to predict TACS according to the patient's clinical manifestations. In this study, we aimed to evaluate whether using the TACScore as a screening method prior to performing whole-exome sequencing (WES) is more cost-effective than using WES as the first-line genetic test for CS. METHODS: We retrospectively collected the molecular data of 416 CS patients in the Deciphering disorders Involving Scoliosis and COmorbidities (DISCO) study. A decision tree was constructed to estimate the cost and the diagnostic time required for the two alternative strategies (TACScore versus WES). Bootstrapping simulations and sensitivity analyses were performed to examine the distributions and robustness of the estimates. The economic evaluation considered both the health care payer and the personal budget perspectives. RESULTS: From the health care payer perspective, the strategy of using the TACScore as the primary screening method resulted in an average cost of $1074.2 (95%CI: $1044.8 to $1103.5) and an average diagnostic duration of 38.7d (95%CI: 37.8d to 39.6d) to obtain a molecular diagnosis for each patient. In contrast, the corresponding values were $1169.6 (95%CI: $1166.9 to $1172.2) and 41.4d (95%CI: 41.1d to 41.7d) taking WES as the first-line test (P < 0.001). From the personal budget perspective, patients who were predicted to be positive by the TACScore received a result with an average cost of $715.1 (95%CI: $594.5 to $835.7) and an average diagnostic duration of 30.4d (95%CI: 26.3d to 34.6d). Comparatively, the strategy of WES as the first-line test was estimated to have significantly longer diagnostic time with an average of 44.0d (95%CI: 43.2d to 44.9d), and more expensive with an average of $1193.4 (95%CI: $1185.5 to $1201.3) (P < 0.001). In 100% of the bootstrapping simulations, the TACScore strategy was significantly less costly and more time-saving than WES. The sensitivity analyses revealed that the TACScore strategy remained cost-effective even when the cost per WES decreased to $8.8. CONCLUSIONS: This retrospective study provides clinicians with economic evidence to integrate the TACScore into clinical practice. The TACScore can be considered a cost-effective tool when it serves as a screening test prior to performing WES.

11.
J Mater Chem B ; 8(28): 6100-6114, 2020 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-32555907

RESUMO

Hydrogels are appealing biomaterials for regenerative medicine since biomimetic modifications of their polymeric network can provide unique physical properties and emulate the native extracellular matrix (ECM). Meanwhile, therapeutic metal ions, such as magnesium ions (Mg2+), not only regulate cellular behaviours but also stimulate local bone formation and healing. However, the absence of a meaningful macroporous structure and the uncompromising mechanical strength are still challenges. Herein, we designed a macroporous composite hydrogel based on mild and fast thiol-ene click reactions. The Pickering emulsion method was adopted to form a macroporous structure and introduce MgO nanoparticles (NPs). The results show that the composite hydrogel possesses good mechanical strength and an evenly distributed macroporous structure. MgO NPs stabilized at the oil/water interface not only function as effective emulsion stabilizers, but also enhance the mechanical properties of hydrogels and mediate the sustained release of Mg2+. In vitro cell experiments demonstrated that the composite hydrogel displays good biocompatibility. More importantly, the release of Mg2+ ions from hydrogels can effectively promote the osteogenic differentiation of BMSCs. Furthermore, an in vivo study showed that macroporous hydrogels can provide a good extracellular matrix microenvironment for in situ osteogenesis and accelerate bone tissue regeneration.

12.
BMC Med Genet ; 21(1): 115, 2020 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-32460719

RESUMO

BACKGROUND: Multiple epiphyseal dysplasia (MED) is a skeletal disorder characterized by delayed and irregular ossification of the epiphyses and early-onset osteoarthritis. At least 66% of the reported autosomal dominant MED (AD-MED) cases are caused by COMP mutations. METHODS: We recruited a four-generation Chinese family with early-onset hip osteoarthritis, flatfoot, brachydactyly, and mild short stature. An assessment of the family history, detailed physical examinations, and radiographic evaluations were performed on the proband and other family members, followed by the performance of whole-exome sequencing (WES). The pathogenicity of the candidate mutation was also analyzed. RESULTS: An AD-MED family with 10 affected members and 17 unaffected members was recruited. The main radiographic findings were symmetrical changes in the dysplastic acetabulum and femoral heads, irregular contours of the epiphyses, a shortened femoral neck, and flatfoot. Lower bone density was also observed in the ankle joints, wrist joints, and knees, as well as irregular vertebral end plates. In the proband, we identified the missense mutation c.1153G > T (p. Asp385Tyr), located in exon 11 of the COMP gene. This mutation was assessed as 'pathogenic' because of its low allele frequency and its high likelihood of co-segregation with disease in the reported family. Sanger sequencing validated the novel heterozygous mutation c.1153G > T (p. Asp385Tyr) in exon 11 of COMP in all affected individuals in the family. CONCLUSIONS: Our results underlined a key role of the Asp385 amino acid in the protein function of COMP and confirmed the pathogenicity of the COMP (c.1153G > T; p. Asp385Tyr) mutation in AD-MED disease. We have therefore expanded the known mutational spectrum of COMP and revealed new phenotypic information for AD-MED.


Assuntos
Proteína de Matriz Oligomérica de Cartilagem/genética , Família , Estudos de Associação Genética , Predisposição Genética para Doença , Mutação , Osteocondrodisplasias/diagnóstico , Osteocondrodisplasias/genética , Adolescente , Adulto , Idoso , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/patologia , Proteína de Matriz Oligomérica de Cartilagem/química , Criança , Feminino , Estudos de Associação Genética/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Moleculares , Linhagem , Fenótipo , Conformação Proteica , Relação Estrutura-Atividade , Sequenciamento Completo do Exoma , Adulto Jovem
13.
Sci Total Environ ; 717: 137142, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32070894

RESUMO

Carbon storage is one of the main objectives for mangrove afforestation. Planting of the exotic species Sonneratia apetala can rapidly increase the mangrove area and biomass. Here, we studied the change in vegetation and the soil carbon stocks along the chronosequence of S. apetala plantations in Qi'ao Island, China. Five sites, including rehabilitated S. apetala of different ages (1, 4, 9, and 15 years) and 40-year-old mature native Kandelia obovata forests were investigated. Vegetation biomass and the soil carbon content from 0 to 100 cm were analyzed. The ecosystem carbon density (vegetation and soil) was then calculated. A positive and linear relationship was observed between the vegetation carbon stocks and age of S. apetala. The 15-year-old S. apetala already had a similar biomass to 40-year-old K. obovata. However, its soil and ecosystem carbon densities remained lower than those of K. obovata. Different from K. obovata, the majority of the biomass of S. apetala was reserved within the stem. Mature K. obovata had a larger proportion of soil carbon stock to ecosystem carbon stock. S. apetala can accumulate biomass rapidly, but it had a lower ecosystem carbon stock than the native mature K. obovata.


Assuntos
Ecossistema , Biomassa , Carbono , China , Ilhas , Qi , Solo
14.
Cancer Sci ; 111(1): 186-199, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31746077

RESUMO

Activity of transcriptional co-activator with PDZ binding domain (TAZ) protein is strongly implicated in the pathogenesis of human cancer and is influenced by tumor metabolism. High levels of lactate concentration in the tumor microenvironment as a result of metabolic reprogramming are inversely correlated with patient overall survival. Herein, we investigated the role of lactate in the regulation of the activity of TAZ and showed that glycolysis-derived lactate efficiently increased TAZ expression and activity in lung cancer cells. We showed that the reactive oxygen species (ROS) generated by lactate-fueled oxidative phosphorylation (OXPHOS) in mitochondria activated AKT and thereby inhibited glycogen synthase kinase 3 beta/beta-transducin repeat-containing proteins (GSK-3ß/ß-TrCP)-mediated ubiquitination and degradation of DNA methyltransferase 1 (DNMT1). Upregulation of DNMT1 by lactate caused hypermethylation of TAZ negative regulator of the LATS2 gene promoter, leading to TAZ activation. Moreover, TAZ binds to the promoter of DNMT1 and is necessary for DNMT1 transcription. Our study showed a molecular mechanism of DNMT1 in linking tumor metabolic reprogramming to the Hippo-TAZ pathway and functional significance of the DNMT1-TAZ feedback loop in the migratory and invasive potential of lung cancer cells.


Assuntos
DNA (Citosina-5-)-Metiltransferase 1/genética , Ácido Láctico/metabolismo , Estresse Oxidativo/genética , Transativadores/genética , Transcrição Genética/genética , Ativação Transcricional/genética , Linhagem Celular Tumoral , Glicogênio Sintase Quinase 3 beta/genética , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Regiões Promotoras Genéticas/genética , Ligação Proteica/genética , Espécies Reativas de Oxigênio/metabolismo
15.
J Hum Genet ; 65(3): 221-230, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31827250

RESUMO

Congenital scoliosis (CS) is a form of scoliosis caused by congenital vertebral malformations. Genetic predisposition has been demonstrated in CS. We previously reported that TBX6 loss-of-function causes CS in a compound heterozygous model; however, this model can explain only 10% of CS. Many monogenic and polygenic CS genes remain to be elucidated. In this study, we analyzed exome sequencing (ES) data of 615 Chinese CS from the Deciphering Disorders Involving Scoliosis and COmorbidities (DISCO) project. Cosegregation studies for 103 familial CS identified a novel heterozygous nonsense variant, c.2649G>A (p.Trp883Ter) in FBN1. The association between FBN1 and CS was then analyzed by extracting FBN1 variants from ES data of 574 sporadic CS and 828 controls; 30 novel variants were identified and prioritized for further analyses. A mutational burden test showed that the deleterious FBN1 variants were significantly enriched in CS subjects (OR = 3.9, P = 0.03 by Fisher's exact test). One missense variant, c.2613A>C (p.Leu871Phe) was recurrent in two unrelated CS subjects, and in vitro functional experiments for the variant suggest that FBN1 may contribute to CS by upregulating the transforming growth factor beta (TGF-ß) signaling. Our study expanded the phenotypic spectrum of FBN1, and provided nove insights into the genetic etiology of CS.


Assuntos
Anormalidades Congênitas/genética , Fibrilina-1/genética , Predisposição Genética para Doença , Escoliose/genética , Criança , Pré-Escolar , Códon sem Sentido/genética , Anormalidades Congênitas/diagnóstico por imagem , Anormalidades Congênitas/fisiopatologia , Exoma/genética , Feminino , Estudos de Associação Genética , Humanos , Lactente , Masculino , Mutação , Mutação de Sentido Incorreto/genética , Linhagem , Escoliose/diagnóstico por imagem , Escoliose/fisiopatologia , Coluna Vertebral/diagnóstico por imagem , Coluna Vertebral/fisiopatologia , Fator de Crescimento Transformador beta/genética
16.
ACS Nano ; 12(1): 627-634, 2018 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-29303553

RESUMO

Although chemical vapor deposition (CVD)-grown carbon nanotube (CNT) arrays are considered ideal materials for constructing high-performance field-effect transistors (FETs) and integrated circuits (ICs), a significant gap remains between the required and achieved densities and purities of CNT arrays. Here, we develop a directional shrinking transfer method to realize up to 10-fold density amplification of CNT array films without introducing detectable damage or defects. In addition, the method improves the film uniformity while retaining the perfect alignment and high carrier mobility of 1600 cm2 V-1 s-1 of CVD-grown CNT arrays. By combining the density amplification method with the thermocapillary flow method developed by Rogers et al., semiconducting CNT arrays with high densities and high qualities are obtained. High-performance FETs with a channel length of 200 nm are demonstrated using these high-density semiconducting CNT arrays, yielding a record-high on-state current density of 150 µA/µm, a peak transconductance of 80 µS/µm, and a current on/off ratio of more than 104 among the CVD-grown CNT-based FETs.

17.
Polymers (Basel) ; 10(9)2018 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-30960874

RESUMO

A hyaluronic acid (HA) based injectable hydrogel with gradually increasing mechanical properties was synthesized via photo-crosslinking reaction and thermal-induced Diels-Alder (DA) reaction. The injectable hydrogel can quickly gelate within 30 s by photo-crosslinking of HA-furan under the catalysis of lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP). This injectable property is beneficial to keep the encapsulated cell activity and convenient for clinical operation. And the mechanical properties can be control from 4.86 to 10.66 kPa by exposure time. Then, the thermal-induced DA click chemistry further occurs between furan groups and maleimide groups which gradually promoted the crosslinking density of the injectable hydrogel. The mechanical properties of the injectable hydrogel can be promoted to 21 kPa. ATDC-5 cells were successfully encapsulated in the injectable hydrogel and showed good activity. All the results suggested that the injectable hydrogel with gradually increasing mechanical properties formed by photo-crosslinking reaction and thermal-induced DA reaction has a good prospect of application in cartilage tissue engineering.

18.
Angew Chem Int Ed Engl ; 56(41): 12553-12556, 2017 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-28799684

RESUMO

The rational design of zeolite-based catalysts calls for flexible tailoring of porosity and acidity beyond micropore dimension. To date, dealumination has been applied extensively as an industrial technology for the tailoring of zeolite in micropore dimension, whereas desilication has separately shown its potentials in the creation of mesoporosities. The free coupling of dealumination with desilication will bridge the tailoring at micro/mesopore dimensions; however, such coupling has been prevailingly confirmed as an impossible mission. In this work, a consecutive dealumination-desilication process enables the introduction of uniform intracrystalline mesopores (4-6 nm) into the microporous Al-rich zeolites. The decisive impacts of steaming step have been firstly discovered. These findings revitalize the functions of dealumination in porosity tailoring, and stimulate the pursuit of new methods for the tailoring of industrially relevant Al-rich zeolites.

19.
Econ Hum Biol ; 22: 177-189, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27235837

RESUMO

This paper uses longitudinal data from China to examine the causal relationship between structural social capital and health among Chinese older adults. We employ various econometric strategies to control for the potential endogeneity of social capital and account for the possible contextual confounding effects by including community-level social capital. We use three indicators to measure individuals' general, physical, and mental health. Results indicate that social capital has a significant and positive effect on general and physical health. Based on our primary IV findings, a one standard-deviation increase in social capital leads to a 4.9 standard-deviation decrease in the probability of having bad health and a 2.2 standard-deviation decrease in physical activity limitations. Our results are robust to a series of sensitivity checks. Further analysis suggests heterogeneous effects by age but not by gender or area of residence.


Assuntos
Nível de Saúde , Saúde Mental , Capital Social , Fatores Etários , China , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Características de Residência , Fatores Sexuais , Fatores Socioeconômicos
20.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 22(5): 1495-8, 2014 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-25338615

RESUMO

DNA extraction is a basic technology of molecular biology. The purity and the integrality of DNA structure are necessary for different experiments of gene engineering. As commonly used materials in the clinical detection, the fast, efficient isolation and extraction of genomic DNA from peripheral blood mononuclear cells is very important for the inspection and analysis of clinical blood. At present, there are many methods for extracting DNA, such as phenol-chloroform method, salting out method, centrifugal adsorption column chromatography method (artificial methods), magnetic beads (semi-automatic method) and DNA extraction kit. In this article, a brief review of the principle for existing DNA blood extraction method, the specific steps and the assessment of the specific methods briefly are summarized.


Assuntos
DNA/isolamento & purificação , Leucócitos Mononucleares , Biologia Molecular/métodos , Genômica , Humanos , Separação Imunomagnética , Leucócitos Mononucleares/química , Fenol
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