Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 60
Filtrar
1.
Mod Pathol ; 37(6): 100493, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38615709

RESUMO

Demand for anal cancer screening is expected to rise following the recent publication of the Anal Cancer-HSIL Outcomes Research trial, which showed that treatment of high-grade squamous intraepithelial lesions significantly reduces the rate of progression to anal cancer. While screening for human papillomavirus-associated squamous lesions in the cervix is well established and effective, this is less true for other sites in the lower anogenital tract. Current anal cancer screening and prevention rely on high-resolution anoscopy with biopsies. This procedure has a steep learning curve for providers and may cause patient discomfort. Scattering-based light-sheet microscopy (sLSM) is a novel imaging modality with the potential to mitigate these challenges through real-time, microscopic visualization of disease-susceptible tissue. Here, we report a proof-of-principle study that establishes feasibility of dysplasia detection using an sLSM device. We imaged 110 anal biopsy specimens collected prospectively at our institution's dysplasia clinic (including 30 nondysplastic, 40 low-grade squamous intraepithelial lesion, and 40 high-grade squamous intraepithelial lesion specimens) and found that these optical images are highly interpretable and accurately recapitulate histopathologic features traditionally used for the diagnosis of human papillomavirus-associated squamous dysplasia. A reader study to assess diagnostic accuracy suggests that sLSM images are noninferior to hematoxylin and eosin images for the detection of anal dysplasia (sLSM accuracy = 0.87; hematoxylin and eosin accuracy = 0.80; P = .066). Given these results, we believe that sLSM technology holds great potential to enhance the efficacy of anal cancer screening by allowing accurate sampling of diagnostic tissue at the time of anoscopy. While the current imaging study was performed on ex vivo biopsy specimens, we are currently developing a handheld device for in vivo imaging that will provide immediate microscopic guidance to high-resolution anoscopy providers.


Assuntos
Neoplasias do Ânus , Infecções por Papillomavirus , Estudo de Prova de Conceito , Humanos , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/patologia , Neoplasias do Ânus/virologia , Neoplasias do Ânus/patologia , Neoplasias do Ânus/diagnóstico por imagem , Feminino , Canal Anal/virologia , Canal Anal/patologia , Canal Anal/diagnóstico por imagem , Lesões Intraepiteliais Escamosas/virologia , Lesões Intraepiteliais Escamosas/patologia , Microscopia/métodos , Masculino , Biópsia , Pessoa de Meia-Idade , Papillomaviridae , Papillomavirus Humano
2.
Sensors (Basel) ; 23(8)2023 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-37112409

RESUMO

The rapid development of information and communication technology has fostered a natural integration of technology and design. As a result, there is increasing interest in Augmented Reality (AR) business card systems that leverage digital media. This research aims to advance the design of an AR-based participatory business card information system in line with contemporary trends. Key aspects of this study include applying technology to acquire contextual information from paper business cards, transmitting it to a server, and delivering it to mobile devices; facilitating interactivity between users and content through a screen interface; providing multimedia business content (video, image, text, 3D elements) via image markers recognized by users on mobile devices, while also adapting the type and method of content delivery. The AR business card system designed in this research enhances traditional paper business cards by incorporating visual information and interactive elements and automatically generating buttons linked to phone numbers, location information, and homepages. This innovative approach enables users to interact and enriches their overall experience while adhering to strict quality control measures.

3.
Small ; 18(3): e2104764, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34761523

RESUMO

Healable stretchable conductive nanocomposites have received considerable attention. However, there has been a trade-off between the filler-induced electrical conductivity (σ) and polymer-driven mechanical strength. Here significant enhancements in both σ and mechanical strength by designing reversible covalent bonding of the polymer matrix and filler-matrix covalent bifunctionalization are reported. A polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene grafted with maleic anhydride forms the strong reversible covalent bonding with furfuryl alcohol through the Diels-Alder reaction. Small (7.5 nm) and medium (117 nm) nanosatellite particles are generated by in situ etching of silver flakes, enabling electron tunneling-assisted percolation. The filler-polymer covalent bifunctionalization is achieved by 3-mercaptopropanoic acid. Altogether, this results in high σ (108 300 S m-1 ) and tensile strength (16.4 MPa), breaking the trade-off behavior. A nearly perfect (≈100%) healing efficiency is achieved in both σ and tensile strength. The conductive nanocomposite figure of merit (1.78 T Pa S m-1 ), defined by the product of σ and tensile strength, is orders of magnitude greater than the data in literature. The nanocomposite may find applications in healable strain sensors and electronic materials.

4.
Int J Mol Sci ; 23(16)2022 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-36012568

RESUMO

Zinc finger protein with KRAB and SCAN domains 3 (ZKSCAN3) acts as an oncogenic transcription factor in human malignant tumors, including colon and prostate cancer. However, most of the ZKSCAN3-induced carcinogenic mechanisms remain unknown. In this study, we identified ZKSCAN3 as a downstream effector of the oncogenic Wnt/ß-catenin signaling pathway, using RNA sequencing and ChIP analyses. Activation of the Wnt pathway by recombinant Wnt gene family proteins or the GSK inhibitor, CHIR 99021 upregulated ZKSCAN3 expression in a ß-catenin-dependent manner. Furthermore, ZKSCAN3 upregulation suppressed the expression of the mitotic spindle checkpoint protein, Mitotic Arrest Deficient 2 Like 2 (MAD2L2) by inhibiting its promoter activity and eventually inducing chromosomal instability in colon cancer cells. Conversely, deletion or knockdown of ZKSCAN3 increased MAD2L2 expression and delayed cell cycle progression. In addition, ZKSCAN3 upregulation by oncogenic WNT/ß-catenin signaling is an early event of the adenoma-carcinoma sequence in colon cancer development. Specifically, immunohistochemical studies (IHC) were performed using normal (NM), hyperplastic polyps (HPP), adenomas (AD), and adenocarcinomas (AC). Their IHC scores were considerably different (61.4 in NM; 88.4 in HPP; 189.6 in AD; 246.9 in AC). In conclusion, ZKSCAN3 could be responsible for WNT/ß-catenin-induced chromosomal instability in colon cancer cells through the suppression of MAD2L2 expression.


Assuntos
Adenocarcinoma , Instabilidade Cromossômica , Neoplasias do Colo , Via de Sinalização Wnt , Adenocarcinoma/genética , Carcinogênese/genética , Linhagem Celular , Linhagem Celular Tumoral , Neoplasias do Colo/patologia , Regulação Neoplásica da Expressão Gênica , Humanos , Proteínas Mad2/genética , Proteínas Mad2/metabolismo , Masculino , Fatores de Transcrição/metabolismo , beta Catenina/metabolismo
5.
Small ; 17(36): e2102525, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34310034

RESUMO

The synthesis of morphologically well-defined peptidic materials via self-assembly is challenging but demanding for biocompatible functional materials. Moreover, switching morphology from a given shape to other predictable forms by molecular modification of the identical building block is an even more complicated subject because the self-assembly of flexible peptides is prone to diverge upon subtle structural change. To accomplish controllable morphology transformation, systematic self-assembly studies are performed using congener short ß-peptide foldamers to find a minimal structural change that alters the self-assembled morphology. Introduction of oxygen-containing ß-amino acid (ATFC) for subtle electronic perturbation on hydrophobic foldamer induces a previously inaccessible solid-state conformational split to generate the most susceptible modification site for morphology transformation of the foldamer assemblies. The site-dependent morphological switching power of ATFC is further demonstrated by dual substitution experiments and proven by crystallographic analyses. Stepwise morphology transformation is shown by modifying an identical foldamer scaffold. This study will guide in designing peptidic molecules from scratch to create complex and biofunctional assemblies with nonspherical shapes.


Assuntos
Oxigênio , Peptídeos , Aminoácidos , Interações Hidrofóbicas e Hidrofílicas , Conformação Molecular
6.
Int J Mol Sci ; 22(17)2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34502226

RESUMO

Autophagy is an evolutionally conserved process that recycles aged or damaged intracellular components through a lysosome-dependent pathway. Although this multistep process is propagated in the cytoplasm by the orchestrated activity of the mTOR complex, phosphatidylinositol 3-kinase, and a set of autophagy-related proteins (ATGs), recent investigations have suggested that autophagy is tightly regulated by nuclear events. Thus, it is conceivable that the nucleolus, as a stress-sensing and -responding intranuclear organelle, plays a role in autophagy regulation, but much is unknown concerning the nucleolar controls in autophagy. In this report, we show a novel nucleolar-cytoplasmic axis that regulates the cytoplasmic autophagy process: nucleolar protein NOP53 regulates the autophagic flux through two divergent pathways, the ZKSCAN3-dependent and -independent pathways. In the ZKSCAN3-dependent pathway, NOP53 transcriptionally activates a master autophagy suppressor ZKSCAN3, thereby inhibiting MAP1LC3B/LC3B induction and autophagy propagation. In the ZKSCAN3-independent pathway, NOP53 physically interacts with histone H3 to dephosphorylate S10 of H3, which, in turn, transcriptionally downregulates the ATG7 and ATG12 expressions. Our results identify nucleolar protein NOP53 as an upstream regulator of the autophagy process.


Assuntos
Autofagia , Nucléolo Celular/metabolismo , Núcleo Celular/metabolismo , Histonas/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Células HEK293 , Histonas/genética , Humanos , Proteínas Associadas aos Microtúbulos/genética , Fosforilação , Fatores de Transcrição/genética , Proteínas Supressoras de Tumor/genética
7.
J Environ Manage ; 286: 112164, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33618322

RESUMO

The co-processing of secondary wastes during ordinary Portland cement (OPC) can result in high heavy metal concentrations in OPC products. However, earlier studies have not evaluated the concentrations of heavy metals (HMs) in OPC as a function of secondary input materials. Further, the health risk assessment (HRA) model has, thus far, has not been employed to assess the potential health risks associated with secondary raw materials and secondary fuels in OPC. Hence, to address these knowledge gaps, herein, monthly data for six HMs in the input materials and fuels from seven OPC manufacturers in the Republic of Korea were analyzed and modeled. Pb and Cu concentrations were found to be approximately 10-200 and 4-200 times higher than those of the other HMs, respectively. Furthermore, maximum Pb and Cu concentrations were 2-3 and 2-5 times higher than those reported in other countries, respectively. The quantity of input material had a significant influence on the observed patterns, and secondary raw materials, secondary additives, and secondary fuels were also determined to be important. Based on HRA assessment, although the risk levels were within permissible ranges, carcinogenic hazards attributable to Cr and Pb were not negligible. The results can aid in informed decision making and in implementing effective measures for managing risks associated with HMs in the OPC industry, thereby ameliorating threats to human health and environment.


Assuntos
Metais Pesados , Poluentes do Solo , China , Materiais de Construção , Monitoramento Ambiental , Humanos , Metais Pesados/análise , República da Coreia , Medição de Risco , Poluentes do Solo/análise
8.
Korean J Parasitol ; 59(4): 393-397, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34470090

RESUMO

Although research conducted in East Asia has uncovered parasite eggs from ancient toilets or cesspits, data accumulated to date needs to be supplemented by more archaeoparasitological studies. We examined a total of 21 soil samples from a toilet-like structure at the Hwajisan site, a Baekje-period royal villa, in present-day Korea. At least 4 species of helminth eggs, i.e., Trichuris trichiura, Ascaris lumbricoides, Clonorchis sinensis, and Trichuris sp. (or Trichuris vulpis) were detected in 3 sediment samples of the structure that was likely a toilet used by Baekje nobles. The eggs of T. trichiura were found in all 3 samples (no. 1, 4, and 5); and A. lumbricoides eggs were detected in 2 samples (no. 4 and 5). C. sinensis and T. vulpis-like eggs were found in no. 5 sample. From the findings of this study, we can suppose that the soil-transmitted helminths were prevalent in ancient Korean people, including the nobles of Baekje Kingdom during the 5th to 7th century.


Assuntos
Aparelho Sanitário , Helmintos , Animais , Ascaris lumbricoides , Humanos , República da Coreia , Solo , Trichuris
9.
New Phytol ; 226(6): 1796-1808, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32020611

RESUMO

Recent studies mainly in Arabidopsis have renewed interest and discussion in some of the key issues in hydrotropism of roots, such as the site of water sensing and the involvement of auxin. We examined hydrotropism in maize (Zea mays) primary roots. We determined the site of water sensing along the root using a nonintrusive method. Kinematic analysis was conducted to investigate spatial root elongation during hydrotropic response. Indole-3-acetic acid (IAA) and other hormones were quantified using LC-MS/MS. The transcriptome was analyzed using RNA sequencing. Main results: The very tip of the root is the most sensitive to the hydrostimulant. Hydrotropic bending involves coordinated adjustment of spatial cell elongation and cell flux. IAA redistribution occurred in maize roots, preceding hydrotropic bending. The redistribution is caused by a reduction of IAA content on the side facing a hydrostimulant, resulting in a higher IAA content on the dry side. Transcriptomic analysis of the elongation zone prior to bending identified IAA response and lignin synthesis/wall cross-linking as some of the key processes occurring during the early stages of hydrotropic response. We conclude that maize roots differ from Arabidopsis in the location of hydrostimulant sensing and the involvement of IAA redistribution.


Assuntos
Raízes de Plantas , Zea mays , Cromatografia Líquida , Ácidos Indolacéticos , Espectrometria de Massas em Tandem , Tropismo , Zea mays/genética
10.
J Chem Phys ; 152(12): 124110, 2020 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-32241122

RESUMO

ACE-Molecule (advanced computational engine for molecules) is a real-space quantum chemistry package for both periodic and non-periodic systems. ACE-Molecule adopts a uniform real-space numerical grid supported by the Lagrange-sinc functions. ACE-Molecule provides density functional theory (DFT) as a basic feature. ACE-Molecule is specialized in efficient hybrid DFT and wave-function theory calculations based on Kohn-Sham orbitals obtained from a strictly localized exact exchange potential. It is open-source oriented calculations with a flexible and convenient development interface. Thus, ACE-Molecule can be improved by actively adopting new features from other open-source projects and offers a useful platform for potential developers and users. In this work, we introduce overall features, including theoretical backgrounds and numerical examples implemented in ACE-Molecule.

11.
J Nanosci Nanotechnol ; 18(10): 7147-7150, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-29954550

RESUMO

The effects of an immiscible, lubricating polydimethylsiloxane fluid, referred to as silicone oil, on the static deformation and on the dynamic motion of a water drop on paper induced by electrowetting were investigated. The deformation of a drop on a hydrophobic film of amorphous fluoropolymers top-coated with less hydrophobic silicone oil was much more predictable, reversible and reproducible than on the uncoated surface. In the dynamic tribological experiment for a sliding drop along an inclined surface, a significant decrease in the friction coefficient, with an unexpected dependency of the contact area, was observed. Based on the curve fitting analysis, the shear stress and the net friction force were estimated quantitatively. Because of the tribological effect and the reduced shear friction force of the oil film, the static and the dynamic electrowetting states of the water drop were enhanced.

12.
Biochem Biophys Res Commun ; 472(1): 95-100, 2016 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-26903295

RESUMO

Glioblastoma tumor suppressive candidate region gene 2 (GLTSCR2) is a nucleolar protein that participates in critical cellular processes including the DNA damage response, cell cycle regulation, and inhibition of MYC-induced transforming activity. Irrespective of these important physiological and pathological functions, the mechanisms that regulate GLTSCR2 expression, and its nucleolar-nucleoplasmic translocation, are largely unknown. HeLa cells were treated with various protein kinase inhibitors and subjected to immunocytochemical or immunoblot assays for GLTSCR2. Protein stability was determined by the cycloheximide chase or ubiquitination assays. Oligomer status was analyzed by immunoprecipitation. Inhibiting c-jun N-terminal kinase (JNK) phosphorylation activity on c-jun by SP600125, or adding a c-jun peptide, induced the nucleoplasmic translocation of GLTSCR2 from the nucleolus and enhanced protein degradation through the proteasome-polyubiquitination pathway. These effects may have resulted from reducing the binding affinity between GLTSCR2 monomers. These data indicate that JNK, and its phosphorylation target c-jun, are prerequisites for the nucleolar distribution of GLTSCR2 and maintenance of its protein stability. Overall, GLTSCR2 is crucial for normal cellular function as well as for preventing the development or progression of cancer. The JNK-c-jun axis is indispensible for regulating the activities of GLTSCR2.


Assuntos
Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Transporte Ativo do Núcleo Celular , Nucléolo Celular/metabolismo , Células HeLa , Humanos , Proteínas Nucleares/química , Proteínas Nucleares/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Estabilidade Proteica , Proteólise , Proteínas Proto-Oncogênicas c-jun/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais , Proteínas Supressoras de Tumor/química , Proteínas Supressoras de Tumor/genética , Ubiquitinação
13.
J Opt Soc Am A Opt Image Sci Vis ; 33(4): 576-88, 2016 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-27140767

RESUMO

The vector radiative transfer problem in a vertically multilayer scattering medium with spatial changes in the index of refraction is solved by the natural element method (NEM). The top boundary of the multilayer medium is irradiated by a collimated beam. In our model, the angular space is discretized by the discrete ordinates approach, and the spatial discretization is conducted by the Galerkin weighted residuals approach. In the solution procedure, the collimated component for the Stokes parameters is first solved by NEM, and then it is embedded into the vector radiative transfer equation for the diffuse component as a source term. To keep the consistency of the directions in all the layers, angular interpolation of the Stokes parameters at the interfaces is adopted. The NEM approach for the collimated component is first validated. Then, the classical coupled atmosphere-water system irradiated by different states of collimated beam is examined to verify the numerical performance of the method. Numerical results show that the NEM is accurate, flexible, and effective in solving polarized radiative transfer in a multilayer medium. Finally, polarized radiative transfer in a four-layer system is investigated and analyzed.

14.
Environ Monit Assess ; 187(1): 4200, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25504191

RESUMO

In Republic of Korea, construction and demolition (C&D) waste accounts for 49.9% of the total waste. In the present work, the mineralogical composition, the concentrations of 11 heavy metals, 19 PAH, and 7 polychlorinated biphenyl (PCB) congeners present in the 6 broad category (9 subcategories) of C&D hazardous waste were discussed along with their leaching characteristics. In concrete/mixed cement waste, the concentrations of As, Cr(6+), Hg, and Zn were in the range of 1.76-7.86, ND-1.63, 0.026-0.047, and 110.90-280.17 mg/kg, respectively. The asphalt waste sample A1 possessed relatively high concentrations of phenanthrene, fluoranthene, pyrene, benz(a)anthracene, benzo(a)pyrene, and indeno(1,2,3-cd)pyrene comparing to the other samples and it contains 0.08-0.1% of coal tar. Hazardous nature of the C&D wastes greatly depends on the source of the collection. Zn concentration was above 1000 mg/kg for road asphalt waste samples A4 and A5. Total PCB concentration were high in the soil waste sample S1 (130 µg/kg) as it was the excavated soil obtained from the premises of an oil station. Leaching of As, Ba, CN(-), and F(-) were observed in most of the C&D waste samples.


Assuntos
Indústria da Construção/estatística & dados numéricos , Monitoramento Ambiental , Resíduos Perigosos/análise , Resíduos Industriais/análise , Resíduos Industriais/estatística & dados numéricos , Metais Pesados/análise , Bifenilos Policlorados/análise , República da Coreia
15.
Mater Horiz ; 10(12): 5720-5728, 2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-37800193

RESUMO

Thermal rectification is an asymmetric heat transport phenomenon where thermal conductance changes depending on the temperature gradient direction. The experimentally reported efficiency of thermal rectification materials and devices, which are applicable for a wide range of temperatures, is relatively low. Here we report a giant thermal rectification efficiency of 218% by maximizing asymmetry in parameters of the Stefan-Boltzmann law for highly non-linear thermal radiation. The asymmetry in emissivity is realized by sputter-depositing manganese (ε = ∼0.38) on the top right half surface of a polyurethane specimen (ε = ∼0.98). The surface area of the polyurethane side is also dramatically increased (1302%) by 3D printing to realize asymmetry in geometry. There is an excellent agreement between the experimentally measured temperature profiles and finite element simulation results, demonstrating the reliability of the analysis. Machine learning analysis reveals that the surface area is a dominant factor for thermal rectification and suggests novel light-weight designs with high efficiencies. This work may find applications in energy efficient thermal rectification management of electronic devices and housings.

16.
Nat Commun ; 14(1): 7508, 2023 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-37980350

RESUMO

Designing robust blue organic light-emitting diodes is a long-standing challenge in the display industry. The highly energetic states of blue emitters cause various degradation paths, leading to collective luminance drops in a competitive manner. However, a key mechanism of the operational degradation of organic light-emitting diodes has yet to be elucidated. Here, we show that electron-induced degradation reactions play a critical role in the short lifetime of blue organic light-emitting diodes. Our control experiments demonstrate that the operational lifetime of a whole device can only be explained when excitons and electrons exist together. We examine the atomistic mechanisms of the electron-induced degradation reactions by analyzing their energetic profiles using computational methods. Mass spectrometric analysis of aged devices further confirm the key mechanisms. These results provide new insight into rational design of robust blue organic light-emitting diodes.

17.
Am J Pathol ; 179(3): 1257-64, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21741933

RESUMO

The cellular DNA damage response (DDR) ensures genomic stability and protects against genotoxic stresses. Conversely, defects in the DDR contribute to genome instability, with the resulting accumulated genetic changes capable of inducing neoplastic transformation. Thus, DDR is central to both the mechanism of oncogenesis and cancer therapy. Specifically, DDR is accomplished via a complicated meshwork of evolutionary conserved proteins, including ATM, ATR, and phospho-H2AX (γH2AX). GLTSCR2 is a nucleolar protein believed to function as a tumor suppressor, although its exact molecular mechanisms have yet to be fully elucidated. As a result of our research pertaining to the role of GLTSCR2 in tumor suppression, we have determined that GLTSCR2 is involved in DDR. Under genotoxic conditions, such as cellular exposure to UV radiation or radiomimetic drugs, GLTSCR2 expression increased and later mobilized to the nucleoplasm. Moreover, GLTSCR2 knockdown attenuated both the presence of phospho-H2AX at the nuclear foci and the phosphorylation of multiple DDR proteins, including ATM, ATR, Chk2, Chk1, and H2AX. In addition, the decreased expression of GLTSCR2 sensitized cells to DNA damage, delayed DNA repair, and abolished G2/M checkpoint activation. Our observations indicate that GLTSCR2 is a key component of DDR and GLTSCR2 seems to act as a tumor suppressor by participating in optimal DDR because DNA damage is a frequent and crucial event in oncogenesis.


Assuntos
Dano ao DNA/fisiologia , Reparo do DNA/fisiologia , Genes Supressores de Tumor/fisiologia , Proteínas Supressoras de Tumor/fisiologia , Dano ao DNA/efeitos da radiação , Reparo do DNA/efeitos da radiação , Regulação para Baixo , Histonas/metabolismo , Humanos , Imuno-Histoquímica , Proteínas Supressoras de Tumor/metabolismo , Regulação para Cima
18.
Micromachines (Basel) ; 13(8)2022 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-36014217

RESUMO

This paper presents the mechanical behaviors of different types of polyimide feedthroughs that are frequently used for implantable polymer encapsulation. Implantable packages of electronic devices often comprise circuits mounted on printed circuit boards (PCBs) encapsulated in a biocompatible polymer material, with input/output feedthroughs for electrical interconnections. The feedthroughs are regarded as essential elements of the reliability of the package since they create inevitable interfaces with the encapsulation materials. Flexible materials are frequently used for feedthroughs owing to their ease of manufacturing; thus, their mechanical properties are crucial as they directly interact with parts of the human body, such as the brain and neurons. For this purpose, tensile tests were performed to characterize the mechanical properties of flexible PCBs (FPCBs) and photosensitive polyimides (PSPIs). Commercial FPCBs and homemade PSPIs of two different thicknesses were subjected to tensile tests for mechanical characterization. The FPCBs showed typical stress-strain curves, while the PSPIs showed brittleness or strain hardening depending on the thickness. The material properties extracted from the tensile tests were used for explicit modeling using the finite element method (FEM) and simulations to assess mechanical behaviors, such as necking and strain hardening.

19.
Micromachines (Basel) ; 13(4)2022 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-35457821

RESUMO

This paper proposed and verified the use of polymer-based packaging to implement the chronic implantation of neural interfaces using a combination of a commercial thermal epoxy and a thin parylene film. The packaging's characteristics and the performance of the vulnerable interface between the thermal epoxy layer and polyimide layer, which is mainly used for neural electrodes and an FPCB, were evaluated through in vitro, in vivo, and acceleration experiments. The performance of neural interfaces-composed of the combination of the thermal epoxy and thin parylene film deposition as encapsulation packaging-was evaluated by using signal acquisition experiments based on artificial stimulation signal transmissions through in vitro and in vivo experiments. It has been found that, when commercial thermal epoxy normally cured at room temperature was cured at higher temperatures of 45 °C and 65 °C, not only is its lifetime increased with about twice the room-temperature-based curing conditions but also an interfacial adhesion is higher with more than twice the room-temperature-based curing conditions. In addition, through in vivo experiments using rats, it was confirmed that bodily fluids did not flow into the interface between the thermal epoxy and FPCB for up to 18 months, and it was verified that the rats maintained healthy conditions without occurring an immune response in the body to the thin parylene film deposition on the packaging's surface.

20.
Artigo em Inglês | MEDLINE | ID: mdl-36141743

RESUMO

Pale chub (Zacco platypus) is a dominant species in urban rivers and reservoirs, and it is used as an indicator to monitor the effects of environmental contaminants. Gene responses at the molecular level can reflect the health of fish challenged with environmental stressors. The objective of this study was to identify correlations between water quality factors and the expression of stress-related genes in Z. platypus from different lake environments (Singal and Juam Lakes). To do so, transcriptional responses of genes involving cellular homeostasis (heat-shock protein 70, HSP70; heat-shock protein 90, HSP90), metal detoxification (metallothionein, MT), and antioxidation (superoxide dismutase, SOD; catalase, CAT) were analyzed in the gill and liver tissues of Z. platypus. HSP70, HSP90, and MT genes were overall upregulated in Z. platypus from Singal Lake, which suffered from poorer water quality than Juam Lake. In addition, gene responses were significantly higher in Singal Lake outflow. Upregulation of HSP70, HSP90, and MT was significantly higher in Z. platypus gills than in the liver tissue. In addition, integrated biomarker response and heatmap analysis determined correlations between expression of biomarker genes or water quality factors and sampling sites of both lakes. These results suggest that stress-related genes used as multiple biomarkers may reflect spatial characteristics and water quality of different lake environments, and they can be used for biomonitoring and ecological risk assessment.


Assuntos
Cyprinidae , Ornitorrinco , Poluentes Químicos da Água , Animais , Monitoramento Biológico , Biomarcadores/metabolismo , Catalase/metabolismo , Cyprinidae/metabolismo , Ecossistema , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Choque Térmico/metabolismo , Metalotioneína , Ornitorrinco/metabolismo , Superóxido Dismutase/metabolismo , Poluentes Químicos da Água/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA