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1.
Proc Natl Acad Sci U S A ; 121(22): e2404007121, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38768347

RESUMO

Sensations of heat and touch produced by receptors in the skin are of essential importance for perceptions of the physical environment, with a particularly powerful role in interpersonal interactions. Advances in technologies for replicating these sensations in a programmable manner have the potential not only to enhance virtual/augmented reality environments but they also hold promise in medical applications for individuals with amputations or impaired sensory function. Engineering challenges are in achieving interfaces with precise spatial resolution, power-efficient operation, wide dynamic range, and fast temporal responses in both thermal and in physical modulation, with forms that can extend over large regions of the body. This paper introduces a wireless, skin-compatible interface for thermo-haptic modulation designed to address some of these challenges, with the ability to deliver programmable patterns of enhanced vibrational displacement and high-speed thermal stimulation. Experimental and computational investigations quantify the thermal and mechanical efficiency of a vertically stacked design layout in the thermo-haptic stimulators that also supports real-time, closed-loop control mechanisms. The platform is effective in conveying thermal and physical information through the skin, as demonstrated in the control of robotic prosthetics and in interactions with pressure/temperature-sensitive touch displays.


Assuntos
Tato , Realidade Virtual , Tecnologia sem Fio , Humanos , Tecnologia sem Fio/instrumentação , Tato/fisiologia , Pele , Robótica/instrumentação , Robótica/métodos
2.
Sensors (Basel) ; 24(9)2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38732939

RESUMO

The problem of energy depletion has brought wind energy under consideration to replace oil- or chemical-based energy. However, the breakdown of wind turbines is a major concern. Accordingly, unsupervised learning was performed using the vibration signal of a wind power generator to achieve an outlier detection performance of 97%. We analyzed the vibration data through wavelet packet conversion and identified a specific frequency band that showed a large difference between the normal and abnormal data. To emphasize these specific frequency bands, high-pass filters were applied to maximize the difference. Subsequently, the dimensions of the data were reduced through principal component analysis, giving unique characteristics to the data preprocessing process. Normal data collected from a wind farm located in northern Sweden was first preprocessed and trained using a long short-term memory (LSTM) autoencoder to perform outlier detection. The LSTM Autoencoder is a model specialized for time-series data that learns the patterns of normal data and detects other data as outliers. Therefore, we propose a method for outlier detection through data preprocessing and unsupervised learning, utilizing the vibration signals from wind generators. This will facilitate the quick and accurate detection of wind power generator failures and provide alternatives to the problem of energy depletion.

3.
J Prosthet Dent ; 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38443239

RESUMO

Mandibular condyle fracture malunion and tooth loss can cause functional and esthetic problems. A patient with restricted mouth opening associated with muscle atrophy required prosthetic rehabilitation. Since the remaining teeth had a poor prognosis and the patient had difficulty adapting to the interim denture, complete mouth rehabilitation with implants was chosen. The implants were placed by using nerve lateralization and an autogenous bone graft. Prosthetic rehabilitation combines digital diagnosis and conventional prosthetic restorations. The definitive prosthesis was fabricated to ensure adequate oral hygiene and functional adaptation of the orofacial structures. Treatment resulted in stable masticatory function, occlusion, and esthetics and restored the function of the atrophied lips and restricted mouth opening.

4.
Sensors (Basel) ; 23(17)2023 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-37687787

RESUMO

In the manufacturing process, equipment failure is directly related to productivity, so predictive maintenance plays a very important role. Industrial parks are distributed, and data heterogeneity exists among heterogeneous equipment, which makes predictive maintenance of equipment challenging. In this paper, we propose two main techniques to enable effective predictive maintenance in this environment. We propose a 1DCNN-Bilstm model for time series anomaly detection and predictive maintenance of manufacturing processes. The model combines a 1D convolutional neural network (1DCNN) and a bidirectional LSTM (Bilstm), which is effective in extracting features from time series data and detecting anomalies. In this paper, we combine a federated learning framework with these models to consider the distributional shifts of time series data and perform anomaly detection and predictive maintenance based on them. In this paper, we utilize the pump dataset to evaluate the performance of the combination of several federated learning frameworks and time series anomaly detection models. Experimental results show that the proposed framework achieves a test accuracy of 97.2%, which shows its potential to be utilized for real-world predictive maintenance in the future.

5.
Int J Mol Sci ; 24(7)2023 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-37047130

RESUMO

Anti-pigmentation peptides have been developed as alternative skin-lightening agents to replace conventional chemicals that have adverse effects on the skin. However, the maximum size of these peptides is often limited by their low skin and cell penetration. To address this issue, we used our intra-dermal delivery technology (IDDT) platform to identify peptides with hypo-pigmenting and high cell-penetrating activity. Using our cell-penetrating peptides (CPPs) from the IDDT platform, we identified RMNE1 and its derivative RMNE3, "DualPep-Shine", which showed levels of α-Melanocyte stimulating hormone (α-MSH)-induced melanin inhibition comparable to the conventional tyrosinase inhibitor, Kojic acid. In addition, DualPep-Shine was delivered into the nucleus and regulated the gene expression levels of melanogenic enzymes by inhibiting the promoter activity of microphthalmia-associated transcription factor-M (MITF-M). Using a 3D human skin model, we found that DualPep-Shine penetrated the lower region of the epidermis and reduced the melanin content in a dose-dependent manner. Furthermore, DualPep-Shine showed high safety with little immunogenicity, indicating its potential as a novel cosmeceutical ingredient and anti-pigmentation therapeutic agent.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos , Peptídeos Penetradores de Células , Melaninas , Melanócitos , Fator de Transcrição Associado à Microftalmia , Proteínas do Tecido Nervoso , Preparações Clareadoras de Pele , Pigmentação da Pele , Transcrição Gênica , Melaninas/antagonistas & inibidores , Pigmentação da Pele/efeitos dos fármacos , Fator de Transcrição Associado à Microftalmia/genética , Transcrição Gênica/efeitos dos fármacos , alfa-MSH/antagonistas & inibidores , alfa-MSH/metabolismo , Humanos , Peptídeos Penetradores de Células/química , Peptídeos Penetradores de Células/farmacologia , Preparações Clareadoras de Pele/química , Preparações Clareadoras de Pele/farmacologia , Melanoma Experimental , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/farmacologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/química , Fatores de Transcrição Hélice-Alça-Hélice Básicos/farmacologia , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Melanócitos/efeitos dos fármacos , Melanócitos/metabolismo , Epiderme/efeitos dos fármacos , Epiderme/metabolismo
6.
J Prosthodont ; 2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-38115183

RESUMO

PURPOSE: The purpose of this in vitro study was to compare the tensile bond strength (TBS) of resin nanoceramics (RNC), zirconia, and lithium disilicate (LS2) restorations cemented to titanium abutments before and after thermomechanical aging. MATERIALS AND METHODS: Twelve specimens per group were fabricated to determine the TBS between a titanium abutment and four types of crown materials (2 RNCs, LS2, and translucent zirconia crowns for the maxillary molar). After milling, the abutments and crowns were cemented with resin cement after air-particle abrasion. In addition, thermomechanical aging (200,000 cycles, 50 N, 2 Hz) was applied to half of the specimens by using a mastication simulator. TBS was measured by using a universal testing machine. The interface between the crown and the cement was observed by using scanning electron microscopy (SEM). Two-way ANOVA was performed to analyze the effects of crown materials and thermomechanical aging. Failure-mode and interface analyses were also conducted. RESULTS: After thermomechanical aging, the TBS decreased in the LS2 specimens and increased in RNCs (p < 0.001). The ratio of mixed failure and debonding with the hole-sealing resin increased in the RNC group. SEM images showed the reduced gap between the crown and the resin cement after thermomechanical aging in the RNC group. CONCLUSIONS: Differences in TBS were affected by the crown materials after thermomechanical aging. After thermomechanical aging, the RNC crowns showed increased TBS, whereas LS2 and zirconia crowns exhibited decreased or similar TBS.

7.
Small ; 18(6): e2106035, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34923744

RESUMO

Transition metal dichalcogenide (TMD) nanosheets exfoliated in the liquid phase are of significant interest owing to their potential for scalable and flexible photoelectronic applications. Although various dispersants such as surfactants, oligomers, and polymers are used to obtain highly exfoliated TMD nanosheets, most of them are electrically insulating and need to be removed; otherwise, the photoelectric properties of the TMD nanosheets degrade. Here, inorganic halide perovskite nanocrystals (NCs) of CsPbX3  (X = Cl, Br, or I) are presented as non-destructive dispersants capable of dispersing TMD nanosheets in the liquid phase and enhancing the photodetection properties of the nanosheets, thus eliminating the need to remove the dispersant. MoSe2 nanosheets dispersed in the liquid phase are adsorbed with CsPbCl3  NCs. The CsPbCl3 nanocrystals on MoSe2 efficiently withdraw electrons from the nanosheets, and suppress the dark current of the MoSe2 nanosheets, leading to flexible near-infrared MoSe2  photodetectors with a high ON/OFF photocurrent ratio and detectivity. Moreover, lanthanide ion-doped CsPbCl3  NCs enhance the ON/OFF current ratio to >106 . Meanwhile, the dispersion stability of the MoSe2  nanosheets exfoliated with the perovskite NCs is sufficiently high.

8.
J Exp Bot ; 73(5): 1415-1428, 2022 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-34718527

RESUMO

Unlike the indispensable function of the steroid hormone brassinosteroid (BR) in regulating plant growth and development, the metabolism of secondary metabolites regulated by BR is not well known. Here we show that BR reduces carotenoid accumulation in Arabidopsis seedlings. BR-deficient or BR-insensitive mutants accumulated higher content of carotenoids than wild-type plants, whereas BR treatment reduced carotenoid content. We demonstrated that BR transcriptionally suppresses 4-HYDROXYPHENYLPYRUVATE DIOXYGENASE (HPPD) expression involved in carotenogenesis via plastoquinone production. We found that the expression of HPPD displays an oscillation pattern that is expressed more strongly in dark than in light conditions. Moreover, BR appeared to inhibit HPPD expression more strongly in darkness than in light, leading to suppression of a diurnal oscillation of HPPD expression. BR-responsive transcription factor BRASSINAZOLE RESISTANT 1 (BZR1) directly bound to the promoter of HPPD, and HPPD suppression by BR was increased in the bzr1-1D gain-of-function mutation. Interestingly, dark-induced HPPD expression did not cause carotenoid accumulation, due to down-regulation of other carotenoid biosynthetic genes in the dark. Our results suggest that BR regulates different physiological responses in dark and light through inhibition of HPPD expression.


Assuntos
4-Hidroxifenilpiruvato Dioxigenase , Proteínas de Arabidopsis , Arabidopsis , 4-Hidroxifenilpiruvato Dioxigenase/genética , 4-Hidroxifenilpiruvato Dioxigenase/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Brassinosteroides/metabolismo , Carotenoides/metabolismo , Regulação da Expressão Gênica de Plantas
9.
Plant Cell ; 31(4): 791-808, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30814258

RESUMO

Brassinosteroid (BR) regulates a wide range of physiological responses through the activation of BRASSINAZOLE RESISTANT1 (BZR1), whose activity is tightly controlled by its phosphorylation status and degradation. Although BZR1 appears to be degraded in distinct ways in response to different hormonal or environmental cues, little is known about how BR signaling regulates its degradation. Here we show that the BR-regulated U-box protein PUB40 mediates the proteasomal degradation of BZR1 in a root-specific manner in Arabidopsis (Arabidopsis thaliana). BZR1 levels were strongly reduced by plant U-box40 (PUB40) overexpression, whereas the pub39 pub40 pub41 mutant accumulated much more BZR1 than wild type in roots. The bzr1-1D gain-of-function mutation reduced the interaction with PUB40, which suppressed PUB40-mediated BZR1 degradation in roots. The cell layer-specific expression of PUB40 in roots helps induce selective BZR1 accumulation in the epidermal layer. Both BR treatment and loss-of-function of PUB40 expanded BZR1 accumulation to most cell layers. In addition, BZR1 accumulation increased the resistance of pub39 pub40 pub41 to low inorganic phosphate availability, as observed in bzr1-1D BRASSINOSTEROID-INSENSITIVE2-induced phosphorylation of PUB40, which mainly occurs in roots, gives rise to BZR1 degradation through enhanced binding of PUB40 to BZR1 and PUB40's stability. Our results suggest a molecular mechanism of root-specific BZR1 degradation regulated by BR signaling.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Brassinosteroides/metabolismo , Raízes de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas
10.
Curr Issues Mol Biol ; 43(1): 226-239, 2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-34071865

RESUMO

Due to the highly immunogenic nature of renal cell carcinoma (RCC), the tumor microenvironment (TME) is enriched with various innate and adaptive immune subsets. In particular, gamma-delta (γδ) T cells can act as potent attractive mediators of adoptive cell transfer immunotherapy because of their unique properties such as non-reliance on major histocompatibility complex expression, their ability to infiltrate human tumors and recognize tumor antigens, relative insensitivity to immune checkpoint molecules, and broad tumor cytotoxicity. Therefore, it is now critical to better characterize human γδ T-cell subsets and their mechanisms in RCCs, especially the stage of differentiation. In this study, we aimed to identify γδ T cells that might have adaptive responses against RCC progression. We characterized γδ T cells in peripheral blood and tumor-infiltrating lymphocytes (TILs) in freshly resected tumor specimens from 20 RCC patients. Furthermore, we performed a gene set enrichment analysis on RNA-sequencing data from The Cancer Genome Atlas (TCGA) derived from normal kidneys and RCC tumors to ascertain the association between γδ T-cell infiltration and anti-cancer immune activity. Notably, RCC-infiltrating CD3low Vγ9Vδ1 T cells with a terminally differentiated effector memory phenotype with up-regulated activation/exhaustion molecules were newly detected as predominant TILs, and the cytotoxic activity of these cells against RCC was confirmed in vitro. In an additional analysis of the TCGA RCC dataset, γδ T-cell enrichment scores correlated strongly with those for CTLs, Th1 cells, "exhausted" T cells, and M1 macrophages, suggesting active involvement of γδ T cells in anti-tumor rather than pro-tumor activity, and Vδ1 cells were more abundant than Vδ2 or Vδ3 cells in RCC tumor samples. Thus, we posit that Vγ9Vδ1 T cells may represent an excellent candidate for adoptive immunotherapy in RCC patients with a high risk of relapse after surgery.


Assuntos
Complexo CD3/imunologia , Carcinoma de Células Renais/imunologia , Neoplasias Renais/imunologia , Linfócitos do Interstício Tumoral/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Linfócitos T/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Complexo CD3/genética , Complexo CD3/metabolismo , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/metabolismo , Citocinas/imunologia , Citocinas/metabolismo , Feminino , Citometria de Fluxo/métodos , Regulação Neoplásica da Expressão Gênica/imunologia , Humanos , Neoplasias Renais/genética , Neoplasias Renais/metabolismo , Linfócitos do Interstício Tumoral/metabolismo , Masculino , Pessoa de Meia-Idade , RNA-Seq/métodos , Receptores de Antígenos de Linfócitos T gama-delta/genética , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Linfócitos T/metabolismo , Microambiente Tumoral/genética , Microambiente Tumoral/imunologia
11.
Plant Cell ; 30(8): 1848-1863, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30065046

RESUMO

Crosstalk between signaling pathways is an important feature of complex regulatory networks. How signal crosstalk circuits are tailored to suit different needs of various cell types remains a mystery in biology. Brassinosteroid (BR) and abscisic acid (ABA) antagonistically regulate many aspects of plant growth and development through direct interactions between components of the two signaling pathways. Here, we show that BR and ABA synergistically regulate stomatal closure through crosstalk between the BR-activated kinase CDG1-LIKE1 (CDL1) and the OPEN STOMATA1 (OST1) of the ABA signaling pathway in Arabidopsis thaliana We demonstrate that the cdl1 mutant displayed reduced sensitivity to ABA in a stomatal closure assay, similar to the ost1 mutant. CDL1 and the BR receptor BR-INSENSITIVE1, but not other downstream components of the BR signaling pathway, were required for BR regulation of stomatal movement. Genetic and biochemical experiments demonstrated that CDL1 activates OST1 by phosphorylating it on residue Ser-7. BR increased phosphorylation of OST1, and the BR-induced OST1 activation was abolished in cdl1 mutants. Moreover, we found that ABA activates CDL1 in an OST1-dependent manner. Taken together, our findings illustrate a cell-type-specific BR signaling branch through which BR acts synergistically with ABA in regulating stomatal closure.


Assuntos
Ácido Abscísico/farmacologia , Brassinosteroides/farmacologia , Estômatos de Plantas/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
12.
Nanotechnology ; 32(50)2021 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-34433151

RESUMO

Recently, the demand for the sensitive detection of nanomaterials and biomolecules has been increasing for evaluating the toxicity of nanomaterials and early diagnosis of diseases. Although many studies have developed new detection assays, these are heavily influenced by the capabilities of the detection equipment. Therefore, the aim of the present study was to improve electrode performance by modifying the surface of the detection electrode using a simple method. Electrode surface modification was performed using carbon nanotubes (CNT) and porous gold nanostructures (NS) with excellent electrical and chemical properties. Through the simple physical deposition of CNT and electrochemical reduction of NS, the increasement of the electrode surface area was achieved. Because of the CNTs attached to the electrodes at the first step, the metal ions constituting the NS can adhere well to the electrodes. Nanoparticles with a porous structure can be generated through electrochemical reduction (cyclic voltammetry) of metal ions attached to electrodes. Consequently, the surface area of the electrode increased and electrochemical performance was improved (confirmed by atomic force microscopy, Nyquist plot and Bode plot). To quantitatively confirm the improvement of electrode performance according to the surface change through the proposed treatment technique, DNA was detected. Unlike previous surface modification studies, the developed surface treatment technique can be applied to a variety of detection equipment. To confirm this, the detection was performed using two detection devices with different operating principles. DNA detection using the two types of equipment confirmed that the detection limit was increased by approximately 1000-fold through applying a simple surface treatment. In addition, this method is applicable to detect various sizes of nanomaterials. The method proposed in this study is simple and has the advantage that it can be applied to various devices and various materials.

13.
Plant Biotechnol J ; 18(11): 2354-2363, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32415911

RESUMO

Bowman-Birk trypsin inhibitors (BBIs) play important roles in animal and plant immunity, but how these protease inhibitors are involved in the immune system remains unclear. Here, we show that the rice (Oryza sativa) BBI protein APIP4 is a common target of a fungal effector and an NLR receptor for innate immunity. APIP4 exhibited trypsin inhibitor activity in vitro and in vivo. Knockout of APIP4 in rice enhanced susceptibility, and overexpression of APIP4 increased resistance to the fungal pathogen Magnaporthe oryzae. The M. oryzae effector AvrPiz-t interacted with APIP4 and suppressed APIP4 trypsin inhibitor activity. By contrast, the rice NLR protein Piz-t interacted with APIP4, enhancing APIP4 transcript and protein levels, and protease inhibitor activity. Our findings reveal a novel host defence mechanism in which a host protease inhibitor targeted by a fungal pathogen is protected by an NLR receptor.


Assuntos
Magnaporthe , Oryza , Proteínas NLR , Oryza/genética , Doenças das Plantas , Proteínas de Plantas/genética , Inibidores da Tripsina
14.
J Orthop Sci ; 25(1): 152-155, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30851995

RESUMO

BACKGROUND: Basicervical hip fractures are relatively rare with greater biomechanical instability compared to the other types of hip fractures. Several studies have reported ambivalent surgical outcomes of basicervical hip fractures. The purpose of this multicenter study was to analyze surgical outcomes of basicervical hip fractures according to the fixation type of proximal femur and lag screw type. METHODS: Among 3220 hip fractures, 145 were classified as basicervical hip fractures. Of those, 106 patients treated with osteosynthesis were included to analyze the surgical complications according to fixation type of proximal femur: sliding hip screw(SHS) and cephalomedullary nail (CMN) groups. Surgical complications including the excessive displacement of fracture and the occurrence of reoperation were evaluated at the final follow up. We further evaluated surgical complications according to lag screw type with subgroup analysis in CMN group: single screw type, blade type and two integrated screw type. RESULTS: Ten patients (9.4%) sustained surgical complications (5 excessive displacements and 5 reoperations). For fixation type of proximal femur, SHS group showed higher tendency of excessive displacement despite no statistical difference between the two groups (p = 0.060). For lag screw type with subgroup analysis in CMN group, single screw type showed statistically high rates of reoperation compared to the other types of lag screw (p = 0.022). CONCLUSION: Basicervical hip fractures treated with osteosynthesis resulted to high rates of surgical complications in this study. However, they could be drastically reduced if CMN with blade type or two integrated screw type were used in the osteosynthesis of basicervical hip fractures.


Assuntos
Parafusos Ósseos , Fixação Interna de Fraturas/instrumentação , Fraturas do Quadril/cirurgia , Reoperação/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Desenho de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
15.
Molecules ; 25(3)2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32046021

RESUMO

We review recent works for nucleophilic fluorination of organic compounds in which the Coulombic interactions between ionic species and/or hydrogen bonding affect the outcome of the reaction. SN2 fluorination of aliphatic compounds promoted by ionic liquids is first discussed, focusing on the mechanistic features for reaction using alkali metal fluorides. The influence of the interplay of ionic liquid cation, anion, nucleophile and counter-cation is treated in detail. The role of ionic liquid as bifunctional (both electrophilic and nucleophilic) activator is envisaged. We also review the SNAr fluorination of diaryliodonium salts from the same perspective. Nucleophilic fluorination of guanidine-containing of diaryliodonium salts, which are capable of forming hydrogen bonds with the nucleophile, is exemplified as an excellent case where ionic interactions and hydrogen bonding significantly affect the efficiency of reaction. The origin of experimental observation for the strong dependence of fluorination yields on the positions of -Boc protection is understood in terms of the location of the nucleophile with respect to the reaction center, being either close to far from it. Recent advances in the synthesis of [18F]F-dopa are also cited in relation to SNAr fluorination of diaryliodonium salts. Discussions are made with a focus on tailor-making promoters and solvent engineering based on ionic interactions and hydrogen bonding.


Assuntos
Fluoretos/química , Ligação de Hidrogênio , Líquidos Iônicos/química , Ânions/química , Cátions/química , Guanidina/química , Metais Alcalinos/química , Solventes/química
17.
Small ; 14(22): e1704024, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29687614

RESUMO

Epitaxial crystallization of thin poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) films is important for the full utilization of their ferroelectric properties. Epitaxy can offer a route for maximizing the degree of crystallinity with the effective orientation of the crystals with respect to the electric field. Despite various approaches for the epitaxial control of the crystalline structure of PVDF-TrFE, its epitaxy on a semiconductor is yet to be accomplished. Herein, the epitaxial growth of PVDF-TrFE crystals on a single-crystalline organic semiconductor rubrene grown via physical vapor deposition is presented. The epitaxy results in polymer crystals globally ordered with specific crystal orientations dictated by the epitaxial relation between the polymer and rubrene crystal. The lattice matching between the c-axis of PVDF-TrFE crystals and the (210) plane of orthorhombic rubrene crystals develops two degenerate crystal orientations of the PVDF-TrFE crystalline lamellae aligned nearly perpendicular to each other. Thin PVDF-TrFE films with epitaxially grown crystals are incorporated into metal/ferroelectric polymer/metal and metal/ferroelectric polymer/semiconductor/metal capacitors, which exhibit excellent nonvolatile polarization and capacitance behavior, respectively. Furthermore, combined with a printing technique for micropatterning rubrene single crystals, the epitaxy of a PVDF-TrFE film is formed selectively on the patterned rubrene with characteristic epitaxial crystal orientation over a large area.

18.
Liver Transpl ; 24(2): 256-268, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29150986

RESUMO

The rhesus monkey (RM) is an excellent preclinical model in kidney, heart, and islet transplantation that has provided the basis for new immunosuppressive protocols for clinical studies. However, there remain relatively few liver transplantation (LT) models in nonhuman primates. In this study, we analyzed the immune cell populations of peripheral blood mononuclear cells (PBMCs) and secondary lymphoid organs along with livers of normal RMs and compared them with those of rejected LT recipients following withdrawal of immunosuppression. We undertook 5 allogeneic ABO compatible orthotopic LTs in monkeys using 5 normal donor monkey livers. We collected tissues including lymph nodes, spleens, blood, and recipient livers, and we performed flow cytometric analysis using isolated immune cells. We found that CD4 or CD8 naïve T cells were normally seen at low levels, and memory T cells were seen at high levels in the liver rather than lymphoid organs or PBMC. However, regulatory cells such as CD4+ forkhead box P3+ T cells and CD8+ CD28- cells remained in high numbers in the liver, but not in the lymph nodes or PBMC. The comparison of CD4/8 T subpopulations in normal and rejected livers and the various tissues showed that naïve cells were dramatically decreased in the spleen, lymph node, and PBMCs of rejected LT monkeys, but rather, the memory CD4/8 T cells were increased in all tissues and PBMC. The normal liver has large numbers of CD4 regulatory T cells, CD8+ CD28-, and myeloid-derived suppressor cells, which are known immunosuppressive cells occurring at much higher levels than those seen in lymph node or peripheral blood. Memory T cells are dramatically increased in rejected liver allografts of RMs compared with those seen in normal RM tissues. Liver Transplantation 24 256-268 2018 AASLD.


Assuntos
Rejeição de Enxerto/imunologia , Memória Imunológica , Transplante de Fígado , Fígado/imunologia , Subpopulações de Linfócitos T/imunologia , Aloenxertos , Animais , Modelos Animais de Doenças , Rejeição de Enxerto/sangue , Imunidade Celular , Imunidade Inata , Linfonodos/imunologia , Macaca mulatta , Masculino , Baço/imunologia , Transplante Homólogo
19.
Mol Ecol ; 27(3): 636-646, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29274176

RESUMO

Understanding the complex influences of landscape and anthropogenic elements that shape the population genetic structure of invasive species provides insight into patterns of colonization and spread. The application of landscape genomics techniques to these questions may offer detailed, previously undocumented insights into factors influencing species invasions. We investigated the spatial pattern of genetic variation and the influences of landscape factors on population similarity in an invasive riparian shrub, saltcedar (Tamarix L.) by analysing 1,997 genomewide SNP markers for 259 individuals from 25 populations collected throughout the southwestern United States. Our results revealed a broad-scale spatial genetic differentiation of saltcedar populations between the Colorado and Rio Grande river basins and identified potential barriers to population similarity along both river systems. River pathways most strongly contributed to population similarity. In contrast, low temperature and dams likely served as barriers to population similarity. We hypothesize that large-scale geographic patterns in genetic diversity resulted from a combination of early introductions from distinct populations, the subsequent influence of natural selection, dispersal barriers and founder effects during range expansion.


Assuntos
Variação Genética , Espécies Introduzidas , Rios , Tamaricaceae/genética , Genética Populacional , Geografia , Modelos Genéticos , Polimorfismo de Nucleotídeo Único/genética , Sudoeste dos Estados Unidos
20.
Mikrochim Acta ; 186(1): 34, 2018 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-30564970

RESUMO

The authors describe an isothermal and ultrasensitive colorimetric DNA assay that consists of two amplification stages using enzymes and a catalytic hairpin assembly (CHA). The first step consists in the selective amplification of DNA using Klenow fragment and nicking enzyme. The second step consists in the amplification of the optical signal by using a catalytic hairpin assembly. After two amplification steps, the DNA reaction induces the aggregation of the red gold nanoparticles to give a blue color shift. The degree of aggregation can be quantified by measurement of the ratio of the UV-vis absorbances of the solutions at 620 and 524 nm which are the wavelengths of the aggregated gold nanoparticles and bare gold nanoparticles. The detection limit is as low as 3.1 fM. Due to the use of a specific enzyme, only the desired DNAs will be detected. The method can be applied to the determination of DNA of various lengths. Despite the presence of large amounts of wildtype DNA, it can readily detect a target DNA. Conceivably, the technique has a large potential because of its high sensitivity and selectivity. Graphical abstract Schematic presentation of DNA detection using gold nanoparticles (AuNP), enzymes and catalytic hairpin assembly (CHA). Effective DNA detection is achieved through the aggregation of AuNPs which is caused by DNA amplification using enzymes and signal amplification using CHA.


Assuntos
DNA/análise , Ouro , Catálise , Colorimetria , Corantes/química , Nanopartículas Metálicas , Técnicas de Amplificação de Ácido Nucleico
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