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1.
J Coll Physicians Surg Pak ; 33(6): 642-646, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37300259

RESUMO

OBJECTIVE: To assess high-risk human papillomavirus (hrHPV) infection among women undergoing cervical cancer screening in Putian for establishing an optimal cervical cancer screening mode and preventive vaccination strategy for HPV. STUDY DESIGN: Cross-sectional study. Place and Duration of the Study: The Affiliated Hospital of Putian University for cervical cancer screening period, from August 2020 to December 2022. METHODOLOGY: Cervical cell specimens were obtained using 'two cancer screening platforms'. qRT-PCR and flow-FISH were used for hrHPV typing. The pathological diagnostic test was performed for the hrHPV-positive samples. The results concerning the relationships between hrHPV infection at different age groups and pathological diagnosis were analysed retrospectively. RESULTS: A total of 98085 hrHPV preliminary screening results in the Putian region and 9036 hrHPV-positive samples were included. The infection rate of hrHPV for the three infection modes increased with age. The 41-50 age group is the highest incidence which the phase from cervical intraepithelial neoplasia to cervical cancer. The top three hrHPV subtypes were HPV52, HPV58, and HPV16. The positive rate of HPV16 was positively correlated with the progression of cervical intraepithelial neoplasia. CONCLUSION: Effective screening, vaccination, and education must be provided because HPV infections are district-specific and age-specific. HPV16 is correlated with cervical cancer progression. Pathological diagnosis and prevention of cervical cancer infected with HPV16 must be conducted. KEY WORDS: hrHPV, Cervical cancer, Pathological diagnosis.


Assuntos
Infecções por Papillomavirus , Displasia do Colo do Útero , Neoplasias do Colo do Útero , Feminino , Humanos , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/prevenção & controle , Estudos Transversais , Papillomavirus Humano , Estudos Retrospectivos , Detecção Precoce de Câncer/métodos , Displasia do Colo do Útero/diagnóstico , China/epidemiologia , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/epidemiologia , Infecções por Papillomavirus/prevenção & controle , Papillomavirus Humano 16 , Papillomaviridae/genética , Genótipo
2.
Educ Inf Technol (Dordr) ; : 1-14, 2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-37361809

RESUMO

During the COVID-19 pandemic, video materials have played crucial roles in supporting learning among children with autism spectrum disorder (ASD). This study aimed to explore the effects of the instructor's facial expressions in video lectures on attention and motor learning in children with ASD versus typically developing (TD) children. A total of 60 children were randomly assigned to four groups: (1) ASD-happy, (2) ASD-neutral, (3) TD-happy, and (4) TD-neutral. Both happy groups paid more attention to the video lectures. The ASD groups achieved higher accuracy and fidelity of motor learning when the instructor smiled. Results revealed that greater attention to video lectures predicted better performance in children with ASD. This study has practical implications for the design of learning materials for children with ASD: An instructor should be encouraged to show a happy expression to promote learning.

3.
Front Genet ; 14: 1139124, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37152985

RESUMO

Objective: For analyzing the distribution characteristics of MTHFR C677T polymorphism in Chinese females in order to provide information for reducing birth defects and formulating public health policies to prevent congenital malformations. Methods: Literature search in the last 6 years on "MTHFR C677T," "polymorphism" and "methylene tetrahydrofolate reductase." The included literature provides the MTHFR C677T frequency in healthy females in the corresponding regions. The data were grouped by the national administrative region as a unit to obtain the distribution information of the MTHFR C677T and alleles in the female population in every province, municipality or autonomous region. This was done for analyzing the overall distribution of the MTHFR C677T allele and the geographical distribution of pregnancy complications. Results: A total of 126 studies were included, covering five autonomous areas, four municipalities directly under the Central Government, as well as 22 provinces (except Taiwan Province) in China. MTHFR C677T polymorphism data of 27 groups of Chinese Han women and 31 groups of other Chinese females were obtained, and the chi-square test revealed notable inter-group differences (p = 0.000). The TT genotype and T allele of MTHFR C677T accounted for 18.2% (4.7%-38.3%) and 40.3% (19.7%-61.4%) of the Chinese female population, respectively, with a significant north-south difference. Chinese females had a consistent frequency of the T allele with the geographical distribution of pregnancy complications such as recurrent abortion and preeclampsia. Conclusion: With a obvious geographical gradient, the MTHFR C677T polymorphism distribution in Chinese females is consistent with the geographical distribution of multiple pregnancy complications, and the risk assessment for it might be included in primary prevention for birth defects.

4.
Polymers (Basel) ; 15(10)2023 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-37242919

RESUMO

In this brief review, we discuss the recent advancements in using poly(ethylene glycol) diacrylate (PEGDA) hydrogels for tissue engineering applications. PEGDA hydrogels are highly attractive in biomedical and biotechnology fields due to their soft and hydrated properties that can replicate living tissues. These hydrogels can be manipulated using light, heat, and cross-linkers to achieve desirable functionalities. Unlike previous reviews that focused solely on material design and fabrication of bioactive hydrogels and their cell viability and interactions with the extracellular matrix (ECM), we compare the traditional bulk photo-crosslinking method with the latest three-dimensional (3D) printing of PEGDA hydrogels. We present detailed evidence combining the physical, chemical, bulk, and localized mechanical characteristics, including their composition, fabrication methods, experimental conditions, and reported mechanical properties of bulk and 3D printed PEGDA hydrogels. Furthermore, we highlight the current state of biomedical applications of 3D PEGDA hydrogels in tissue engineering and organ-on-chip devices over the last 20 years. Finally, we delve into the current obstacles and future possibilities in the field of engineering 3D layer-by-layer (LbL) PEGDA hydrogels for tissue engineering and organ-on-chip devices.

5.
ACS Appl Polym Mater ; 5(4): 3034-3042, 2023 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-37090424

RESUMO

Three-dimensional (3D) printed hydrogels fabricated using light processing techniques are poised to replace conventional processing methods used in tissue engineering and organ-on-chip devices. An intrinsic potential problem remains related to structural heterogeneity translated in the degree of cross-linking of the printed layers. Poly(ethylene glycol) diacrylate (PEGDA) hydrogels were used to fabricate both 3D printed multilayer and control monolithic samples, which were then analyzed using atomic force microscopy (AFM) to assess their nanomechanical properties. The fabrication of the hydrogel samples involved layer-by-layer (LbL) projection lithography and bulk cross-linking processes. We evaluated the nanomechanical properties of both hydrogel types in a hydrated environment using the elastic modulus (E) as a measure to gain insight into their mechanical properties. We observed that E increases by 4-fold from 2.8 to 11.9 kPa transitioning from bottom to the top of a single printed layer in a multilayer sample. Such variations could not be seen in control monolithic sample. The variation within the printed layers is ascribed to heterogeneities caused by the photo-cross-linking process. This behavior was rationalized by spatial variation of the polymer cross-link density related to variations of light absorption within the layers attributed to spatial decay of light intensity during the photo-cross-linking process. More importantly, we observed a significant 44% increase in E, from 9.1 to 13.1 kPa, as the indentation advanced from the bottom to the top of the multilayer sample. This finding implies that mechanical heterogeneity is present throughout the entire structure, rather than being limited to each layer individually. These findings are critical for design, fabrication, and application engineers intending to use 3D printed multilayer PEGDA hydrogels for in vitro tissue engineering and organ-on-chip devices.

6.
ACS Appl Polym Mater ; 5(2): 1180-1190, 2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36817334

RESUMO

Hydrogels are commonly used materials in tissue engineering and organ-on-chip devices. This study investigated the nanomechanical properties of monolithic and multilayered poly(ethylene glycol) diacrylate (PEGDA) hydrogels manufactured using bulk polymerization and layer-by-layer projection lithography processes, respectively. An increase in the number of layers (or reduction in layer thickness) from 1 to 8 and further to 60 results in a reduction in the elastic modulus from 5.53 to 1.69 and further to 0.67 MPa, respectively. It was found that a decrease in the number of layers induces a lower creep index (CIT) in three-dimensional (3D) printed PEGDA hydrogels. This reduction is attributed to mesoscale imperfections that appear as pockets of voids at the interfaces of the multilayered hydrogels attributed to localized regions of unreacted prepolymers, resulting in variations in defect density in the samples examined. An increase in the degree of cross-linking introduced by a higher dosage of ultraviolet (UV) exposure leads to a higher elastic modulus. This implies that the elastic modulus and creep behavior of hydrogels are governed and influenced by the degree of cross-linking and defect density of the layers and interfaces. These findings can guide an optimal manufacturing pathway to obtain the desirable nanomechanical properties in 3D printed PEGDA hydrogels, critical for the performance of living cells and tissues, which can be engineered through control of the fabrication parameters.

7.
Theriogenology ; 201: 30-40, 2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-36827867

RESUMO

In oocytes, the cytoplasmic polyadenylation and maternal mRNAs translation is regulated by cis-elements, including polyadenylation signal (PAS) and cytoplasmic polyadenylation element (CPE) in 3'-UTR. Recent studies illustrate non-canonical polyadenylation mechanisms of translational regulation in mouse oocytes, which is different from that in Xenopus oocytes. However, it is still unclear if this regulation in rodent oocytes functions in the domestic animal oocyte. Here, by using sheep as an animal model, we cloned the 3'-UTRs of Cpeb1 or Btg4 and ligated it into the pRK5-Flag-Gfp vector. Variant numbers and positions of PASs and CPEs within the 3'-UTRs were constructed to detect their effects on translational control. After in vitro-transcription and microinjection into sheep fully grown germinal vesicle stage oocytes, the expression efficiency of mRNAs was detected by the GFP and flag expression. Our results show that: (i) PAS located at the proximal end of 3'-UTR can mediate the translation of the maternal mRNAs, as long as they locate far from CPEs; (ii) The proximal PAS has higher efficiency in regulating transcription than the distal one; (iii) increase of PAS number can promote the translational activity more efficiently; (iv) a single CPE located close to PAS (<50 bp) in 3'-UTRs of Cpeb1 or Btg4 could partially repress translation. In 3'-UTRs of Btg4, two CPEs have a higher inhibitory effect, and three CPEs can completely inhibit mRNA translation. These results confirm the existence of the non-canonical mechanism in domestic animal oocytes.


Assuntos
Poliadenilação , Biossíntese de Proteínas , Animais , Camundongos , Ovinos/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Oócitos/metabolismo , Citoplasma/metabolismo , Regiões não Traduzidas , Regiões 3' não Traduzidas
8.
iScience ; 25(4): 104106, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35402886

RESUMO

La2Zr2O7 coatings are promising candidates to substitute YSZ coatings in advanced gas turbine engines. In this work, Sm-doped La2Zr2O7 coatings were deposited by physical vapor deposition. This work focuses on the crystal structure, thermal conductivity, thermal expansion coefficient, morphology, composition, and thermal durability of LaSmZrO coatings. The LaSmZrO ceramics exhibit low thermal conductivity (1.69 W/mK at 800°C) and high thermal expansion coefficient (9.72∗10-6 K-1 at 1500°C) compared with La2Zr2O7. The LaSmZrO/YSZ coatings with feathery microstructure show relatively good thermal durability (8183 cycles or 856 h) under high temperature. The broken regions are observed at the ceramic coating/bond coating interface. The failure behaviors are relevant with crack evolution and thermally grown oxide growth. This work might guide the investigation of advanced coatings under high temperature.

9.
ACS Appl Mater Interfaces ; 13(49): 58434-58446, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34866391

RESUMO

In vitro small intestinal models aim to mimic the in vivo intestinal function and structure, including the villi architecture of the native tissue. Accurate models in a scalable format are in great demand to advance, for example, the development of orally administered pharmaceutical products. Widely used planar intestinal cell monolayers for compound screening applications fail to recapitulate the three-dimensional (3D) microstructural characteristics of the intestinal villi arrays. This study employs stereolithographic 3D printing to manufacture biocompatible hydrogel-based scaffolds with villi-like micropillar arrays of tunable dimensions in poly(ethylene glycol) diacrylates (PEGDAs). The resulting 3D-printed microstructures are demonstrated to support a month-long culture and induce apicobasal polarization of Caco-2 epithelial cell layers along the villus axis, similar to the native intestinal microenvironment. Transport analysis requires confinement of compound transport to the epithelial cell layer within a compound diffusion-closed reservoir compartment. We meet this challenge by sequential printing of PEGDAs of different molecular weights into a monolithic device, where a diffusion-open villus-structured hydrogel bottom supports the cell culture and mass transport within the confines of a diffusion-closed solid wall. As a functional demonstrator of this scalable dual-material 3D micromanufacturing technology, we show that Caco-2 cells seeded in villi-wells form a tight epithelial barrier covering the villi-like micropillars and that compound-induced challenges to the barrier integrity can be monitored by standard high-throughput analysis tools (fluorescent tracer diffusion and transepithelial electrical resistance).


Assuntos
Materiais Biocompatíveis/metabolismo , Hidrogéis/metabolismo , Intestino Delgado/metabolismo , Modelos Biológicos , Impressão Tridimensional , Alicerces Teciduais/química , Materiais Biocompatíveis/química , Células CACO-2 , Células Cultivadas , Humanos , Hidrogéis/química , Intestino Delgado/química , Teste de Materiais , Polietilenoglicóis/química , Polietilenoglicóis/metabolismo
10.
Clin Lab ; 67(6)2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34107633

RESUMO

BACKGROUND: Balanced translocation of chromosomes has a negative impact on male fertility, which can easily cause clinical manifestations such as oligospermia and asthenospermia. It is necessary to conduct cytogenetic examination on men of childbearing age to guide them in their fertility. METHODS: We report a case of balanced translocation: 46, XY, t(9;22) (q22;q13) accompanied with oligospermia and asthenospermia. The lymphocytes in peripheral blood were cultured to examine the patient's karyotype. RESULTS: The karyotypes of the patient and the patient's wife were detected and identified as 46, XY, t(9;22) (9pter→9q22::22q13→22qter;22pter→22q13::9q22→9qter) and 46, XX, respectively. The origin of the chromosome translocation was unknown because the patient's parents did not undergo cytogenetic tests. CONCLUSIONS: For patients with oligospermia and asthenospermia, cytogenetic examination should be carried out to obtain a healthy fetus. Prenatal diagnosis should be strictly performed to prevent the birth of children with chromosomal diseases if one partner of the couple is a carrier with abnormal chromosome structure.


Assuntos
Transtornos Cromossômicos , Oligospermia , Criança , Aberrações Cromossômicas , Feminino , Humanos , Cariotipagem , Masculino , Oligospermia/diagnóstico , Oligospermia/genética , Gravidez , Translocação Genética
11.
Sci Rep ; 11(1): 6007, 2021 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-33727653

RESUMO

We investigated the nucleation and grain growth of graphene grown on Cu through radio frequency plasma-enhanced chemical vapor deposition (RF-PECVD) at different temperatures. A reasonable shielding method for the placement of copper was employed to achieve graphene by RF-PECVD. The nucleation and growth of graphene grains during PECVD were strongly temperature dependent. A high growth temperature facilitated the growth of polycrystalline graphene grains with a large size (~ 2 µm), whereas low temperature induced the formation of nanocrystalline grains. At a moderate temperature (790 to 850 °C), both nanocrystalline and micron-scale polycrystalline graphene grew simultaneously on Cu within 60 s with 50 W RF plasma power. As the growth time increased, the large graphene grains preferentially nucleated and grew rapidly, followed by the nucleation and growth of nanograins. There was competition between the growth of the two grain sizes. In addition, a model of graphene nucleation and grain growth during PECVD at different temperatures was established.

12.
Nanotechnology ; 32(9): 095607, 2021 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-33217746

RESUMO

The controllable synthesis of high-quality and large-area graphene by chemical vapor deposition (CVD) remains a challenge nowadays. The massive grain boundaries in graphene grown on polycrystalline Cu by CVD significantly reduce its carrier mobility, limiting its application in high-performance electronic devices. Here, we confirm that the synergetic pretreatment of Cu with electropolishing and surface oxidation is a more efficient way to further suppress the graphene nucleation density (GND) and to accelerate the growth rate of the graphene domain by CVD. With increasing the growth time, we found that the increasing amount of GND and growth rate of the graphene domain were both decreasing during the whole CVD process when the Cu surface was not oxidized. By contrast, they kept growing over time when the Cu surface was pre-oxidized, which suggested that the change trends of the effects on the GND and growth rate between the Cu surface morphology and oxygen were opposite in the CVD process. In addition, not only the domain shape, but the number of graphene domain layers were impacted as well, and a large number of irregular ellipse graphene wafers with dendritic multilayer emerged when the Cu surface was oxidized.

13.
Biomater Sci ; 8(14): 3856-3870, 2020 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-32572407

RESUMO

siRNA-mediated RNA interference (RNAi) against inflammation-related genes provides a promising modality for the treatment of myocardial ischemia reperfusion (IR) injury, and its success is critically dependent on the development of efficient yet safe siRNA delivery vehicles. Herein, we developed a bioreducible, branched poly(ß-amino ester) with built-in redox-responsive domains (BPAE-SS) for the effective ICAM-1 siRNA delivery into injured rat cardiac microvascular endothelial cells (RCMECs). The branched BPAE-SS with a multivalent structure afforded potent siRNA binding affinity compared to its linear analogue, while upon internalization into RCMECs it was instantaneously degraded by intracellular glutathione (GSH) into small segments to mediate "on-demand" siRNA release and diminish the toxicity of post-transfection materials. By synchronizingly overcoming these critical barriers, BPAE-SS mediated remarkable ICAM-1 knockdown in IR-injured rats at 400 µg siRNA per kg via single i.v. injection, and subsequently suppressed myocardial inflammation, apoptosis, and fibrosis to recover the cardiac function. This study therefore provides a unique delivery system that can address the multiple critical challenges against non-viral siRNA delivery, and the potent therapeutic efficacy of BPAE-SS-mediated ICAM-1 silencing provides a promising strategy for the anti-inflammatory treatment of myocardial IR injury.


Assuntos
Traumatismo por Reperfusão Miocárdica , Animais , Anti-Inflamatórios , Células Endoteliais , Ésteres , Molécula 1 de Adesão Intercelular/genética , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/terapia , Polímeros , RNA Interferente Pequeno/genética , Ratos
14.
Food Res Int ; 125: 108520, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31554137

RESUMO

S. enterica is an important foodborne pathogen worldwide. As some strains can form biofilms which may offer protection against antimicrobials, it is of interest to explore ways to prevent biofilm formation by S. enterica. In this study, we engineered a short ß-sheet peptide WK2 (WKWKCTKSGCKWKW-NH2) and examined its antimicrobial and anti-biofilm activities against various S. enterica strains, including the multidrug-resistant S. Typhimurium DT104. WK2 displayed bacteriostatic activity with a geometric mean (GM) minimum inhibitory concentration (MIC) of 4.17 µg/mL, and bactericidal activity, with a GM lethal concentration (LC) of 7.51 µg/mL. Crystal violet staining and fluorescence measurements demonstrated that WK2 inhibited S. Typhimurium DT104 biofilm formation at 0.5 µg/mL and killed the sessile cells in biofilms at 8 µg/mL. Real-time polymerase chain reaction (qPCR) and microscopic observation revealed that the anti-biofilm activity of WK2 likely arises through the formation of complexes with bacterial DNA, inhibition of surface organelle biosynthesis and interference with autoinducer-2 (AI-2)-mediated quorum sensing (QS). Therefore, WK2 is a promising antimicrobial agent for the prevention and control of biofilms produced by multidrug-resistant S. enterica.


Assuntos
Antibacterianos , Biofilmes/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla , Salmonella enterica/efeitos dos fármacos , Antibacterianos/química , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Conformação Proteica em Folha beta
15.
Sci Rep ; 9(1): 13386, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31527751

RESUMO

The ability to generate, amplify, mix, and modulate sound with no harmonic distortion in a passive opto-acoustic device would revolutionize the field of acoustics. The photo-thermo-acoustic (PTA) effect allows to transduce light into sound without any bulk electro-mechanically moving parts and electrical connections, as for conventional loudspeakers. Also, PTA devices can be integrated with standard silicon complementary metal-oxide semiconductor (CMOS) fabrication techniques. Here, we demonstrate that the ultimate PTA efficiency of graphene aerogels, depending on their particular thermal and optical properties, can be experimentally achieved by reducing their mass density. Furthermore, we illustrate that the aerogels behave as an omnidirectional pointsource throughout the audible range with no harmonic distortion. This research represents a breakthrough for audio-visual consumer technologies and it could pave the way to novel opto-acoustic sensing devices.

16.
Biomater Sci ; 7(9): 3717-3728, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31187803

RESUMO

Anti-inflammatory RNA interference (RNAi) provides a promising paradigm for the treatment of myocardial ischemia reperfusion (IR) injury. To overcome the membrane barriers against intracardial siRNA delivery, various guanidinated helical polypeptides with potent and aromaticity-assisted membrane activities were herein developed and used for the delivery of siRNA against RAGE (siRAGE), a critical regulator of the pro-inflammatory cascade. Aromatic modification of the polypeptide led to notably enhanced trans-membrane siRNA delivery efficiencies, and more importantly, allowed more siRNA cargoes to get internalized via non-endocytosis, an effective pathway toward gene transfection. Subsequently, benzyl-modified polypeptide (P-Ben) was identified as the top-performing material with the highest RAGE silencing efficiency yet lowest cytotoxicity in H9C2 cells. Intracardial injection of the P-Ben/siRAGE polyplexes at 150 µg siRNA per kg led to remarkable RAGE knockdown by ∼85%, thereby attenuating the inflammatory cytokine release and reducing the cardiomyocyte apoptosis as well as myocardium fibrosis to recover the cardiac function after IR injury. This study therefore provides an effective strategy for the design of membrane-penetrating gene delivery materials, and may provide a promising addition to the anti-inflammatory treatment of myocardial IR injury.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Guanidina/farmacologia , Inflamação/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Peptídeos/química , RNA Interferente Pequeno/farmacologia , Animais , Anti-Inflamatórios não Esteroides/síntese química , Anti-Inflamatórios não Esteroides/química , Apoptose/efeitos dos fármacos , Linhagem Celular , Guanidina/análogos & derivados , Guanidina/química , Inflamação/patologia , Masculino , Estrutura Molecular , Traumatismo por Reperfusão Miocárdica/patologia , Peptídeos/síntese química , Interferência de RNA , RNA Interferente Pequeno/química , Ratos , Ratos Sprague-Dawley
17.
Chem Soc Rev ; 46(23): 7469, 2017 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-29098211

RESUMO

Correction for 'The physics and chemistry of graphene-on-surfaces' by Guoke Zhao, Xinming Li, Meirong Huang et al., Chem. Soc. Rev., 2017, 46, 4417-4449.

18.
Lab Chip ; 17(24): 4273-4282, 2017 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-29116271

RESUMO

Three-dimensional (3D) in vitro models capturing both the structural and dynamic complexity of the in vivo situation are in great demand as an alternative to animal models. Despite tremendous progress in engineering complex tissue/organ models in the past decade, approaches that support the required freedom in design, detail and chemistry for fabricating truly 3D constructs have remained limited. Here, we report a stereolithographic high-resolution 3D printing technique utilizing poly(ethylene glycol) diacrylate (PEGDA, MW 700) to manufacture diffusion-open and mechanically stable hydrogel constructs as self-contained chips, where confined culture volumes are traversed and surrounded by perfusable vascular-like networks. An optimized resin formulation enables printing of hydrogel chips holding perfusable microchannels with a cross-section as small as 100 µm × 100 µm, and the printed microchannels can be steadily perfused for at least one week. In addition, the integration of multiple independently perfusable and structurally stable channel systems further allows for easy combination of different bulk material volumes at exact relative spatial positions. We demonstrate this structural and material flexibility by embedding a highly compliant cell-laden gelatin hydrogel within the confines of a 3D printed resilient PEGDA hydrogel chip of intermediate compliance. Overall, our proposed strategy represents an automated, cost-effective and high resolution technique to manufacture complex 3D constructs containing microfluidic perfusion networks for advanced in vitro models.


Assuntos
Técnicas de Cultura de Células/instrumentação , Hidrogéis/química , Técnicas Analíticas Microfluídicas/instrumentação , Impressão Tridimensional , Alicerces Teciduais , Desenho de Equipamento , Células Endoteliais da Veia Umbilical Humana , Humanos , Modelos Biológicos , Perfusão
19.
Chem Soc Rev ; 46(15): 4417-4449, 2017 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-28678225

RESUMO

Graphene has demonstrated great potential in next-generation electronics due to its unique two-dimensional structure and properties including a zero-gap band structure, high electron mobility, and high electrical and thermal conductivity. The integration of atom-thick graphene into a device always involves its interaction with a supporting substrate by van der Waals forces and other intermolecular forces or even covalent bonding, and this is critical to its real applications. Graphene films on different surfaces are expected to exhibit significant differences in their properties, which lead to changes in their morphology, electronic structure, surface chemistry/physics, and surface/interface states. Therefore, a thorough understanding of the surface/interface properties is of great importance. In this review, we describe the major "graphene-on-surface" structures and examine the roles of their properties and related phenomena in governing the overall performance for specific applications including optoelectronics, surface catalysis, anti-friction and superlubricity, and coatings and composites. Finally, perspectives on the opportunities and challenges of graphene-on-surface systems are discussed.

20.
Glob Chall ; 1(6): 1700037, 2017 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31565284

RESUMO

Electronic tongue is widely applied in liquid sensing for applications in various fields, such as environmental monitoring, healthcare, and food quality test. A rapid and simple liquid-sensing method can greatly facilitate the routine quality tests of liquids. Nanomaterials can help miniaturize sensing devices. In this work, a broad-spectrum liquid-sensing system is developed for rapid liquid recognition based on disposable graphene-polymer nanocomposite test paper prepared through ion-assisted filtration. Using this liquid-sensing system, a number of complex liquids are successfully recognized, including metal salt solutions and polymer solutions. The electronic tongue system is especially suitable for checking the quality of the foodstuff, including soft drinks, alcoholic liquor, and milk. The toxicants in these liquids can be readily detected. Furthermore, the novel material-structure design and liquid-detection method can be expanded to other chemical sensors, which can greatly enrich the chemical information collected from the electrical response of single chemiresistor platform.

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